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SDLRC - Scientific Articles all years by Author - S-Sd


The Sheahan Diamond Literature Reference Compilation
The Sheahan Diamond Literature Reference Compilation is compiled by Patricia Sheahan who publishes on a monthly basis a list of new scientific articles related to diamonds as well as media coverage and corporate announcementscalled the Sheahan Diamond Literature Service that is distributed as a free pdf to a list of followers. Pat has kindly agreed to allow her work to be made available as an online digital resource at Kaiser Research Online so that a broader community interested in diamonds and related geology can benefit. The references are for personal use information purposes only; when available a link is provided to an online location where the full article can be accessed or purchased directly. Reproduction of this compilation in part or in whole without permission from the Sheahan Diamond Literature Service is strictly prohibited. Return to Diamond Resource Center
Sheahan Diamond Literature Reference Compilation - Scientific Articles by Author for all years
A-An Ao+ B-Bd Be-Bk Bl-Bq Br+ C-Cg Ch-Ck Cl+ D-Dd De-Dn Do+ E F-Fn Fo+ G-Gh Gi-Gq Gr+ H-Hd He-Hn Ho+ I J K-Kg Kh-Kn Ko-Kq Kr+ L-Lh
Li+ M-Maq Mar-Mc Md-Mn Mo+ N O P-Pd Pe-Pn Po+ Q R-Rh Ri-Rn Ro+ S-Sd Se-Sh Si-Sm Sn-Ss St+ T-Th Ti+ U V W-Wg Wh+ X Y Z
Sheahan Diamond Literature Reference Compilation - Media/Corporate References by Name for all years
A B C D-Diam Diamonds Diamr+ E F G H I J K L M N O P Q R S T U V W X Y Z
Tips for Users
Posted/Published Reference CodesThe SDLRC provides 3 types of references identified in the reference code. DS for scientific article, DM for a media article, and DC for a corporate announcement. Consider DS0512-0001. The DS stands for "diamond scientific". 05 stands for 2005, the year the reference was posted. 12 represents the month the reference was posted. For all years prior to 2015 the default month is 12. -0001 is the reference's identifier and it does not mean anything. The number below the refence code, ie 2015, is the year the article was published. Note that the posted year may sometimes be later than the published year.
Sort OrderReferences are sorted by the "author" name and when the reference was posted to the compilation.
Most RecentIf the reference code is highlighted yellow, the reference was made available through the most recent monthly compilation of new literature. Use this to check out new references. When new references are posted, we make it our priority to track down an online link and obtain an abstract. With regard to older references, tracking down an abstract and an online link is a work in progress.
Link to external location of article: If the title has a link, it means we have found a location online where you can either retrieve the full article free, or purchase access to it. The Sheahan Diamond Literature Service is not a technical article procurement service; if you want a restricted article, you must deal directly with the vendor who controls the copyright to the article.
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Author Index
A-An Ao+ B-Bd Be-Bk Bl-Bq Br+ C-Cg Ch-Ck Cl+ D-Dd De-Dn Do+ E F-Fn Fo+ G-Gh Gi-Gq Gr+ H-Hd He-Hn Ho+ I J K-Kg Kh-Kn Ko-Kq Kr+ L-Lh
Li+ M-Maq Mar-Mc Md-Mn Mo+ N O P-Pd Pe-Pn Po+ Q R-Rh Ri-Rn Ro+ S-Sd Se-Sh Si-Sm Sn-Ss St+ T-Th Ti+ U V W-Wg Wh+ X Y Z
Sheahan Diamond Literature Reference Compilation - Scientific Articles by Author for all years - S-Sd
Posted/
Published
AuthorTitleSourceRegionKeywords
DS202109-1460
2021
SDey, M., Bhattacharjee, S., Chakrabarty, A., Mitchell, R.H., Pal, S., Pal, S, Sen, A.K. Compositional variation and genesis of pyrochlore, belkovite and baotite from the Sevattur carbonatite complex, India.Mineralogical Magazine, Vol. 85, 4, pp. 588-606.Indiadeposit - Sevattur

Abstract: Pyrochlore-group minerals are common in the Neoproterozoic Sevattur carbonatite complex. This complex is composed of dolomite-, calcite-, banded- and blue carbonatite together with pyroxenite, albitite and diverse syenites. This work reports the paragenetic-textural types and compositional variation of pyrochlore hosted by dolomite carbonatite, banded carbonatite and albitite together with that of alteration assemblages containing belkovite and baotite. On the basis of composition, five different types of pyrochlore are recognised and termed Pcl-I through to Pcl-V. The Pb-rich Pcl-I are present exclusively as inclusions in U-rich Pcl-IIa in dolomite carbonatite. The alteration assemblages of Pb-poor Pcl-IIb + Ba-rich or Ba-Si- rich Pcl-IV + belkovite (dolomite carbonatite) and Si-rich Pcl-V + baotite (banded carbonatite) formed after Pcl-IIa differ in these carbonatites. The albitite hosts extremely U-Ti-rich Pcl-III, mantled by Ba-rich potassium feldspar. In common with the banded carbonatite, Pcl-V is formed by alteration of Pcl-III where this mantle is partially, or completely broken. The Ba-Si-enrichment of Pcl-IV and Pcl-V together with the ubiquitous presence of baryte in all Sevattur lithologies suggests late-stage interaction with a Ba-Si-rich acidic hydrothermal fluid. This fluid was responsible for leaching silica from the associated silicates and produced Pcl-V in the silicate-rich lithologies of the banded carbonatite and albitite. The absence of Pcl-V in dolomite carbonatite is a consequence of the low modal abundance of silicates. The complex compositional diversity and lithology specific pyrochlore alteration assemblages suggest that all pyrochlore (Pcl-I to Pcl-IV) were formed initially in an unknown source and transported subsequently in their respective hosts as altered antecrysts.
DS202109-1461
2021
SDey, M., Mitchell, R.H., Bhattacharjee, S., Chakrabarty, A., Pal, S., Pal, S, Sen, A.K. Compositiion and genesis of albitite-hosted antecrystic pyrochlore from the Sevattur carbonatite complex, Inida.Mineralogical Magazine, Vol. 85, 4, pp. 568-587.Indiadeposit - Sevattur

Abstract: The Neoproterozoic Sevattur complex is composed essentially of calcite and dolomite carbonatites together with pyroxenites and diverse syenites. This work reports the compositions and paragenesis of different pyrochlore generations hosted by albitite veins in this complex. The pyrochlore are distinctive, being exceptionally rich in uranium (26 to 36 wt.% UO2). Five types of pyrochlore (Pcl-I to Pcl-V) are recognised on the basis of composition and texture. With the exception of Pcl-V, the majority of the pyrochlore (Pcl-II to Pcl-IV) are surrounded by a thick orbicular mantle of Ba-rich potassium feldspar. This mantle around Pcl-V is partially-broken. Pcl-I is restricted to the cores of crystals, and associated with Pcl-II and -III and is relatively rich in Nb (0.53-0.62 apfu) together with more A-site vacancies (0.37-0.71 apfu) compared to Pcl-II to Pcl-IV. Other pyrochlore (Pcl-II to Pcl-IV) are characterised by elevated Ca and Ti compared to Pcl-I, which are related to the (3Nb5+ + Na+ ? 3Ti4+ + U4+) and (2Nb5+ ? 2Ti4+ + Ca2+) substitutions, respectively. These substitutions represent replacement of Pcl-II to Pcl-IV. Alteration and Ba-enrichment in all the pyrochlore are marked by interaction with an externally-derived Ba-rich hydrothermal fluid following the (2Nb5+ ? 2Ti4+ + Ba2+) substitution. This substitution, coupled with extensive metamictisation leads to the formation of Ba-rich (15.9-16.3 wt.% BaO) patchy-zoned Pcl-V. The orbicular mantles around Pcl-I to Pcl-IV have prevented extensive metamictisation and extensive secondary alteration compared to Pcl-V, where mantling is partially disrupted. The compositional and textural variation suggests that Pcl-II to Pcl-IV form by nucleation on Pcl-I, and are transported subsequently as antecrysts in the host albitite.
DS202205-0730
2021
SWang, W., Sueno, S,m Yurimoto, H., Takahashi, E.Geochemical study of eclogitic mineral inclusions from Chinese diamonds.Researchgate Chapter, 8p. PdfChinadiamond inclusions

Abstract: Major and trace element geochemistry of eclogitic mineral inclusions from Chinese diamonds are reported in this study, for the first time. Bulk major element compositions of mantle eclogite, estimated from diamond inclusions, are very close to that of MORB. All the analyzed samples exhibit evident positive Eu anomalies. Estimated bulk trace element compositions of mantle eclogite are generally parallel to that of MORB, but with deviations like enrichment in LILE and depletion in HFSE. It is proposed that the formation of mantle eclogite could be closely related to recycling of ancient oceanic crust. Other processes like (1) metasomatism by incompatible trace element rich melts; or (2) remelting and interaction with mantle peridotite, may also be involved. Coexisting of olivine with eclogitic mineral inclusions in a same diamond host, and evident trace element variations in some mineral inclusions show that some diamonds were formed by disequilibrium growth.
DS202203-0370
2022
S, -A.Wang, Ze-Zhou, Liu, S,-A., Rudnick, R.L., Haggerty, R.S.Zinc isotope evidence for carbonate alteration of oceanic crustal protoliths of cratonic eclogites,Earth and Planetary Science Letters, Vol. 580, 11p. PdfMantleeclogites

Abstract: Zinc isotopic compositions (ZnJMC-Lyon) of low-MgO (<13 wt.%) and high-MgO (>16 wt.%) eclogites from the Koidu kimberlite complex, Sierra Leone, West African Craton, help constrain the origins of cratonic eclogites. The Zn of low-MgO eclogites range from MORB-like to significantly higher values (0.21‰ to 0.75‰), and correlate inversely with Zn concentrations. Since marine carbonates are characterized by higher Zn and lower Zn concentration than basaltic rocks, the low-MgO eclogites are suggested to originate from altered oceanic crustal protoliths that underwent isotopic exchange with carbonates within the crust during subduction. Compared to low-MgO eclogites, all but one of the high-MgO eclogites also have high Zn (0.35‰ to 0.95‰), but they have lower Zn concentrations and Zn/Fe ratios, both of which are negatively correlated with MgO contents. These features point to formation of high-MgO eclogites via metasomatic overprinting of low-MgO eclogites through addition of secondary clinopyroxenes crystallized from infiltrating ultramafic melts. Thus, both low-MgO and high-MgO eclogites bear the imprint of subducted carbonate-bearing oceanic crust. Our study shows that the distinctively high-Zn signatures of marine carbonates can be retained in deeply subducted oceanic crust that may contribute to mantle sources of intraplate alkali basalts with elevated Zn and Zn/Fe. Therefore, Zn isotopes provide a viable means to trace carbonate recycling in the mantle.
DS202007-1176
2019
S, S.Saha, G., Rai, S,S., ShalivahanOccurrence of diamond in peninsular India and its relationship with deep Earth seismic properties.Journal of Earth System Science, Vol. 128, 43, 8p. PdfIndiageophysics, seismics

Abstract: An improved shear wave velocity (Vs) structure of the lithosphere of peninsular India using the surface wave tomography from the ambient noise and earthquake waveforms suggests its bipolar character. While most of the geological domains of India are characterised by a uniform lithospheric mantle of Vs?4.5 km/s, the three cratonic regions, eastern Dharwar, Bastar and Singhbhum, hosting most of the diamondiferous kimberlite fields, show significantly high Vs of 4.7 km/s and above in their lower lithosphere beyond ?90 km depth. The higher velocity could best be explained by the presence of diamond and/or eclogite along with peridotite in mantle. This unique relationship suggests the regional seismic image of lithosphere as a guide for exploration of diamonds.
DS202104-0604
2021
S & P Global Market IntelligenceS & P Global Market IntelligenceWorld Exploration Trends 2021S & P for PDAC, 13p. PdfGlobalmarkets
DS202106-0967
2019
S&P GlobalS&P GlobalThe socialeconomic and environmental impact of large-scale diamond mining.Trucost, https://dpawordpress.s3. amazonaws.com/ Trucost _Socioeconomic_and_Environmental_Impact_ of_Large-Scale_ Diamond_ Mining+(2)-min.pdf 37p.Globaldiamond mining

Abstract: In 2017, the DPA engaged Trucost, part of S&P Global, to undertake a world-first comprehensive analysis of the total value contribution of the DPA members, considering all material socioeconomic and environmental benefits and impacts. The study sought to capture not only the economic benefits of diamond mining, which are well understood, but also the social and environmental benefits and impacts associated with the production process. The Trucost Total Value methodology seeks to quantify and capture the full value of these benefits and impacts to provide an assessment of the value created by the DPA members.
DS201804-0732
2018
S&P Global Market IntelligenceS&P Global Market IntelligenceWorld Exploration trends.PDAC , 12p. PdfGlobaleconomics
DS201812-2878
2018
S.Shaikh, A.M., Patel, S.C., Bussweiler, Y., Kumar, S.P.K., Tappe, S., Mainkar, D. Ravi, S.Olivine trace element compositions in diamondiferous lamproites from India: proxies for magma origins and the nature of the lithosphere mantle beneath the Bastar and Dharwar cratons. CC2 and P13 Wajrakarur, Kodomali, Behradih Mainpur Lithos, doi:10.1016/j. lithos.2018.11.026 35p.Indiadeposit - Wajrakarur, Mainpur

Abstract: The ~1100 Ma CC2 and P13 lamproite dykes in the Wajrakarur Kimberlite Field (WKF), Eastern Dharwar Craton, and ~65 Ma Kodomali and Behradih lamproite diatremes in the Mainpur Kimberlite Field (MKF), Bastar Craton share a similar mineralogy, although the proportions of individual mineral phases vary significantly. The lamproites contain phenocrysts, macrocrysts and microcrysts of olivine set in a groundmass dominated by diopside and phlogopite with a subordinate amount of spinel, perovskite, apatite and serpentine along with rare barite. K-richterite occurs as inclusion in olivine phenocrysts in Kodomali, while it is a late groundmass phase in Behradih and CC2. Mineralogically, the studied intrusions are classified as olivine lamproites. Based on microtextures and compositions, three distinct populations of olivine are recognised. The first population comprises Mg-rich olivine macrocrysts (Fo89-93), which are interpreted to be xenocrysts derived from disaggregated mantle peridotites. The second population includes Fe-rich olivine macrocrysts (Fo82-89), which are suggested to be the product of metasomatism of mantle wall-rock by precursor lamproite melts. The third population comprises phenocrysts and overgrowth rims (Fo83-92), which are clearly of magmatic origin. The Mn and Al systematics of Mg-rich olivine xenocrysts indicate an origin from diverse mantle lithologies including garnet peridotite, garnet-spinel peridotite and spinel peridotite beneath the WKF, and mostly from garnet peridotite beneath the MKF. Modelling of temperatures calculated using the Al-in-olivine thermometer for olivine xenocrysts indicates a hotter palaeogeotherm of the SCLM beneath the WKF (between 41 and 43 mW/m2) at ~1100 Ma than beneath the MKF (between 38 and 41 mW/m2) at ~65 Ma. Further, a higher degree of metasomatism of the SCLM by precursor lamproite melts has occurred beneath the WKF compared to the MKF based on the extent of CaTi enrichment in Fe-rich olivine macrocrysts. For different lamproite intrusions within a given volcanic field, lower Fo olivine overgrowth rims are correlated with higher phlogopite plus oxide mineral abundances. A comparison of olivine overgrowth rims from the two fields shows that WKF olivines with lower Fo content than MKF olivines are associated with increased XMg in spinel and phlogopite and vice versa. Melt modelling indicates relatively Fe-rich parental melt for WKF intrusions compared to MKF intrusions. The Ni/Mg and Mn/Fe systematics of magmatic olivines indicate derivation of the lamproite melts from mantle source rocks with a higher proportion of phlogopite and/or lower proportion of orthopyroxene for the WKF on the Eastern Dharwar Craton compared to those for the MKF on the Bastar Craton. This study highlights how olivine cores provide important insights into the composition and thermal state of cratonic mantle lithosphere as sampled by lamproites, including clues to elusive precursor metasomatic events. Variable compositions of olivine rims testify to the complex interplay of parental magma composition and localised crystallisation conditions including oxygen fugacity variations, co-crystallisation of groundmass minerals, and assimilation of entrained material.
DS202001-0015
2018
S.E.Hodder, T. Kelley, S.E.Kimberlite indicator minerals and clast lithology composition of till, Kaskattama region northeastern Manitoba (parts of NTS 53N, O, 54 B,C.)Manitoba Report, GS2018-13 pdf 17p. Canada, Manitobageochemistry

Abstract: Canada exhibits many of the challenges involved with exploring for coloured stones in countries with very low population densities, temperate-to-arctic climates and a lack of infrastructure hindering access to most prospective areas. Despite this, a number of discoveries have occurred, mainly during the past two decades. These include emeralds from Northwest Territories (1997) and Yukon (1998); sapphire (2002) and spinel (from 1982)—including cobalt-blue stones—from Baffin Island in Nunavut; and ruby and pink sapphire (2002) from British Columbia. Such discoveries can be assisted by undertaking scientific research into gem formation, as well as by applying exploration criteria developed elsewhere to uncharted territory. Future exploration in Canada and other countries facing similar challenges will likely benefit from additional geological studies to identify prospective areas and features; innovative means of transportation, such as boats instead of aircraft; drones for exploring rugged terrain; hyperspectral imaging for mineral sensing; surveying with UV lamps to identify minerals associated with gem mineralisation; and careful prospecting (including field mapping and collecting heavy mineral concentrates) by experienced individuals. Quaternary geology fieldwork was conducted at a reconnaissance-scale in the Kaskattama highland area to document the Quaternary stratigraphy and till composition. The diamond potential of this region was investigated using kimberlite-indicator-mineral (KIM) counts from till samples. Indicator mineral results are the focus of this report and are combined with ice-flow and till-clast-lithology data to provide a context to interpret provenance. Kimberlite-indicator minerals were recovered from glacial sediments (till) in the Kaskattama highland area and KIM counts are elevated relative to data from the surrounding area. The lowest KIM counts were from till with a high Hudson Bay Basin (carbonatedominated) and low undifferentiated greenstone and greywacke (UGG) provenance signature. The highest KIM counts are associated with till samples that have a relatively elevated UGG or elevated granitoid provenance signature. Till samples with relatively elevated UGG concentration have an interpreted east or southeast provenance, which is supported by ice-flow data and the recovery of distinct east-sourced erratics. Till samples with a relatively elevated granitoid clast concentration have a correlation with the southwest- trending Hayes streamlined-landform flowset. Considering the likely provenance for granitoid clasts is to the northwest, the presence of relatively high concentrations of granitoid clasts in the Hayes flowset could be indicative of a higher inheritance from previous ice-flow events or a palimpsest dispersal pattern. Interpretation of till-composition and ice-flow data has indicated there are likely multiple sources for the KIMs recovered during this study. Detailed work is recommended to clarify local-scale dispersal patterns.
DS1860-1005
1897
S.F.F.S.F.F.A Lady's Visit to the Diamond Mines at KimberleyLeisure Hour., P. 176.Africa, South AfricaHistory
DS202112-1919
2021
S.S.Ashchepkov, I.V., Alymova, N.V., Loginova, A.M., Vladykin, N.V.. Kuligin, S.S., Mityukhin, S.I., Stegnitsky, Y.B., Prokopiev, S.A.Picroilmenites in Yakutian kimberlites: variations and genetic models.Lithos, Vol. 406-407. doi: 10.1016/j.lithos.2021.106499 77p. PdfRussiakimberlite genesis

Abstract: Major and trace element variations in picroilmenites from Late Devonian kimberlite pipes in Siberia reveal similarities within the region in general, but show individual features for ilmenites from different fields and pipes. Empirical ilmenite thermobarometry (Ashchepkov et al., 2010), as well as common methods of mantle thermobarometry and trace element geochemical modeling, shows long compositional trends for the ilmenites. These are a result of complex processes of polybaric fractionation of protokimberlite melts, accompanied by the interaction with mantle wall rocks and dissolution of previous wall rock and metasomatic associations. Evolution of the parental magmas for the picroilmenites was determined for the three distinct phases of kimberlite activity from Yubileynaya and nearby Aprelskaya pipes, showing heating and an increase of Fe# (Fe# = Fe / (Fe + Mg) a.u.) of mantle peridotite minerals from stage to stage and splitting of the magmatic system in the final stages. High-pressure (5.5–7.0 GPa) Cr-bearing Mg-rich ilmenites (group 1) reflect the conditions of high-temperature metasomatic rocks at the base of the mantle lithosphere. Trace element patterns are enriched to 0.1–10/relative to primitive mantle (PM) and have flattened, spoon-like or S- or W-shaped rare earth element (REE) patterns with Pb > 1. These result from melting and crystallization in melt-feeding channels in the base of the lithosphere, where high-temperature dunites, harzburgites and pyroxenites were formed. Cr-poor ilmenite megacrysts (group 2) trace the high-temperature path of protokimberlites developed as result of fractional crystallization and wall rock assimilation during the creation of the feeder systems prior to the main kimberlite eruption. Inflections in ilmenite compositional trends probably reflect the mantle layering and pulsing melt intrusion during melt migration within the channels. Group 2 ilmenites have inclined REE enriched patterns (10–100)/PM with La / Ybn ~ 10–25, similar to those derived from kimberlites, with high-field-strength elements (HFSE) peaks (typical megacrysts). A series of similar patterns results from polybaric Assimilation + fractional crystallization (AFC) crystallization of protokimberlite melts which also precipitated sulfides (Pb < 1) and mixed with partial melts from garnet peridotites. Relatively low-Ti ilmenites with high-Cr content (group 3) probably crystallized in the metasomatic front under the rising protokimberlite source and represent the product of crystallization of segregated partial melts from metasomatic rocks. Cr-rich ilmenites are typical of veins and veinlets in peridotites crystallized from highly contaminated magma intruded into wall rocks in different levels within the mantle columns. Ilmenites which have the highest trace element contents (1000/PM) have REE patterns similar to those of perovskites. Low Cr contents suggest relatively closed system fractionation which occurred from the base of the lithosphere up to the garnet–spinel transition, according to monomineral thermobarometry for Mir and Dachnaya pipes. Restricted trends were detected for ilmenites from Udachnaya and most other pipes from the Daldyn–Alakit fields and other regions (Nakyn, Upper Muna and Prianabarie), where ilmenite trends extend from the base of the lithosphere mainly up to 4.0 GPa. Interaction of the megacryst forming melts with the mantle lithosphere caused heating and HFSE metasomatism prior to kimberlite eruption.
DS2000-0848
2000
Sa Carneiro Chaves, M.L.Sa Carneiro Chaves, M.L., Dussin, T.M., Sano, Y.The source of the Espinhaco diamonds: evidences from Shrimp uranium-lead (U-Pb) zircon ages of Sopa conglomerate....Revista Brasileira e Geociencas, Vol. 30, No. 2, pp. 265-9.Brazil, Minas GeraisGeochronology, Deposit - Espinhaco
DS200712-0923
2007
Sa Gupta, R.Sa Gupta, R., Hirschmann, M.M., Smith, N.D.Partial melting experiments of peridotite + CO2 at 3 GPa and genesis of alkalic Ocean Island basalts.Journal of Petrology, Vol. 48, 11, pp. 2093-2124.MantleMelting
DS201012-0648
2010
SA MiningSA MiningNew mining regulations under the microscope.SA Mining, Jan, pp. 50-52.Africa, South AfricaNews item - legal
DS1998-1273
1998
Saal, A.E.Saal, A.E., Rudnick, R.L., Ravizza, G.E., Hart, S.R.Re - Os isotope evidence for the composition, formation and age of the lower continental crustNature, Vol. 393, No. 6680, May pp. 58-60GlobalGeochronology
DS201912-2824
2019
Saal, A.E.Shimizu, K., Saal, A.E., Hauri, E.H., Perfit, M.R., Hekinian, R.Evaluating the roles of melt rock interaction and partial degassing on the CO2/Ba ratios of MORB: implications of the CO2 budget in the Earth's depleted upper mantle.Geocimica et Cosmochimica Acta , Vol. 260, pp. 29-48.Mantlemelting

Abstract: Carbon content in the Earth's depleted upper mantle has been estimated in previous studies using CO2/Ba ratios of CO2 undersaturated depleted mid-ocean ridge basalt (D-MORB) glasses and melt inclusions. However, CO2/Ba ratios in CO2 undersaturated MORB may not necessarily record those of the mantle source, as they may be affected by (1) assimilation of Ba-rich plagioclase-bearing rocks in the oceanic crust and (2) CO2 degassing through partial degassing and mixing. In this study, we evaluate these effects on the CO2/Ba ratios as well as other volatile to refractory trace element ratios (H2O/Ce, F/Nd, Cl/K, and S/Dy) in D-MORBs using the compositions of olivine-hosted melt inclusions and glasses from the Siqueiros and Garrett transform faults. The Siqueiros and Garrett melt inclusions are CO2 undersaturated and highly depleted in incompatible trace elements, and their average CO2/Ba ratios show relatively large ranges of 90?±?34 and 144?±?53 respectively. A subset of melt inclusions in lavas from both transform faults show potential signatures of contamination by plagioclase-rich rocks, such as correlations between major elements contents (e.g., FeO, Al2O3, and MgO), and trace element ratios (e.g., Sr/Nd). We find that (1) assimilation fractional crystallization (AFC) of gabbro into D-MORB and (2) mixing between partial melts of gabbro and D-MORB can reproduce the observed range in Sr/Nd ratios as well as the general trends between major elements. However, we find that these processes had limited effects on the CO2/Ba ratio of the melt inclusions and it is unlikely that they can account for the observed range in the CO2/Ba ratio. On the other hand, while a partial degassing and mixing model can generate melts with large range of CO2/Ba ratios (as proposed by Matthews et al. (2017)), it cannot reproduce the Pearson correlation coefficients between CO2/trace element and 1/trace element ratios observed in the Siqueiros and Garrett melt inclusions. Instead, when analytical uncertainties on the elemental concentrations are considered, a model without partial degassing can adequately reproduce the majority of the observed range in CO2/Ba ratio and Pearson correlation coefficients. Hence, we postulate that the Siqueiros and Garrett melt inclusions are undegassed and use their average CO2/Ba ratios to estimate the Siqueiros and Garrett mantle source CO2 contents (21?±?2?ppm and 33?±?6?ppm respectively). We also evaluate the effects of shallow level crustal processes on H2O/Ce, F/Nd, Cl/K, and S/Dy ratios, and after which we filter those effects, we estimate the H2O, F, Cl and S contents in the mantle sources of the Siqueiros (40?±?8?ppm, 8?±?1?ppm, 0.22?±?0.04?ppm, and 113?±?3?ppm) and Garrett (51?±?9?ppm, 6?±?1?ppm, 0.27?±?0.07?ppm, and 128?±?7?ppm) melt inclusions.
DS202111-1763
2021
Saal, A.E.Chin, E.J., Chilson-Parks, B., Boneh, Y., Hirth, G., Saal, A.E., Hearn, B.C., Hauri, E.H.The peridotite deformation cycle in cratons and the deep impact of subduction.Tectonophysics, Vol. 817, 229029, 22p. PdfUnited States, Wyomingdeposit - Homestead, Williams

Abstract: Xenoliths play a crucial role in interpretation of mantle deformation and geochemistry. The classic work of Mercier and Nicolas (1975) introduced the concept of the peridotite deformation cycle, which connected observed microstructures to a physical sequence of deformation. We revisit Mercier and Nicolas' original concept, bringing in new constraints using large area EBSD maps and associated microstructural datasets, analysis of water contents in nominally anhydrous minerals, and trace element chemistry of pyroxenes and garnets. We apply these techniques to a well-characterized suite of peridotite xenoliths from the Eocene-age Homestead and Williams kimberlites in the northwestern Wyoming Craton. Pyroxene water content and trace element mineral chemistries reveal ubiquitous hydrous metasomatism beneath the craton, most likely linked to the Cenozoic Laramide Orogeny. Homestead xenoliths primarily exhibit coarse protogranular and equigranular textures, B-type olivine fabrics, and generally elevated mineral water contents compared to Williams. Xenoliths from Williams are strongly deformed, with porphyroclastic and transitional textures containing annealed olivine tablets, mostly A-type olivine fabrics, and generally lower mineral water contents. As a whole, mantle from Homestead to Williams reflects a cratonic scale deformation cycle that likely initiated in Laramide times and lasted until the end of orogeny in the Eocene. At Williams, evidence for a rapid deformation “sub-cycle” within the main deformation cycle is preserved in the tablet-bearing xenoliths, corresponding to the enigmatic “transitional” texture of Mercier and Nicolas (1975). Our results suggest that this texture reflects interruption of the main deformation cycle by processes possibly related to a rapidly forming lithospheric instability and generation of the kimberlite magma - offering a new interpretation of this ambiguous peridotite texture. Collectively, our results incorporate typically disparate geochemical and textural datasets on xenoliths to shed new insights into how metasomatism, volatiles, and deformation are connected in the deep cratonic lithosphere.
DS200612-1196
2006
SaalmannSaalmann, Helffrich, G.Small scale seismic heterogeneity and mantle structure.Astronomy and Geophysics, Vol. 47, 1., pp.1.20-1.26.MantleGeophysics - seismics
DS200812-0988
2008
Saalmann, K.Saalmann, K., Remus, M.V.D., Hartmann, L.A.Neoproterozoic magmatic arc assembly in the southern Brazilian Shield constraints for a plate tectonic model for the Brasilliano Orogeny.Geotectonic Research, Vol. 95, suppl. 1 pp. 41-59.South America, BrazilMagmatism, Tectonics
DS201112-0895
2011
Saalmann, K.Saalmann, K., Gerdes, A., Lahaye, Y., Hartmann, L.A., Remus, M.V.D., Laufer, A.Multiple accretion at the eastern margin of the Rio de la Plat a craton: the prolonged Brasiliano orogeny in southernmost Brazil.International Journal of Earth Sciences, Vol. 100, 2, pp. 355-378.South America, BrazilCraton, not specific to diamonds
DS1996-0315
1996
Saandar, M.Cunningham, W.D., Windley, B.F., Saandar, M.Late Cenozoic transpression in southwestern Mongolia and the Gobi Altai Tien Shan connection.Earth and Planetary Science Letters, Vol. 140, No. 1-4, May 1, pp. 67-82.China, MongoliaTectonics
DS1989-1322
1989
Saari, D.S.Saari, D.S.A first look at Bib/search bibliographic database a management systemDatabase, Vol. 12, No. 3, June pp. 67-69. Database # 17983GlobalComputer, Program - Bib/search
DS1989-1323
1989
Saari, D.S.Saari, D.S., Foster, G.A.Head to head evaluation of the Pro-cite and Sci-mate bibliographic database management systemsDatabase, Vol. 12, No. 1, February pp. 22-38. Database # 17984GlobalComputer, Program - Pro-cite/Sci-mate
DS1990-0891
1990
Saarnisto, M.Kujansuu, R., Saarnisto, M.Glacial indicator tracingA.a. Balkema, 260pFinland, SwedenGeomorphology, Glacial tills
DS2001-0625
2001
Saavuori, H.Korhonen, J.V., Zhdanova, L., Chepik, A., Zuikova, J., Sazonov, K., Saavuori, H.Magnetic anomaly map of central FIn land - KareliaGeological Society of Finland [email protected], 1: 1 million scale approx. 15.00FinlandBlank
DS200412-1041
2001
Saavuori, H.Korhonen, J.V., Zhdanova, L., Chepik, A., Zuikova, J., Sazonov, K., Saavuori, H.Magnetic anomaly map of central FIn land - Karelia.Geological Society of Finland publication_sales @gtk.fi, 1: 1 million scale approx. 15.00Europe, FinlandMap - geophysics, magnetics
DS1998-0943
1998
Sabadini, P.Marotta, A.M., Fernandez, M., Sabadini, P.Mantle uprooting in collisional settingsTectonophysics, Vol. 296, No. 1-2, pp. 31-46.MantleTectonics, Collision
DS1994-1022
1994
Sabadini, R.Lefftz, M., Sabadini, R., Legros, H.Mantle rheology, viscomagnetic coupling at the core mantle boundary and differential rotation of the core induced by Pleistocene deglaciation.Geophys. Journal of International, Vol. 117, No. 1, April pp. 1-18.MantleBoundary, Rheology
DS1998-1537
1998
Sabadini, R.Vermeersen, L.L.A., Sabadini, R., Bianco, G.Mantle viscosity inferences from joint inversions of Pleistocene deglaciation induced changes - geopotentialGeophs. Res. Lett., Vol. 25, No. 23, Dec. 1, pp. 4261-64.GlobalPolar wander - SIR analysis, Geomorphology
DS2001-0250
2001
Sabadini, R.Devoti, R., Luceri, V., Sabadini, R.The SLR secular gravity variations and their impact on the inference of mantle rheology and lithospheric thickGeophysical Research Letters, Vol. 28, No. 5, Mar. 1, pp. 855-858.MantleGeophysics - gravity
DS2002-1378
2002
Sabadini, R.Sabadini, R., Marotta, A.M., De Franco, R., Vermeersen, L.L.A.Style of density stratification in the mantle and true polar wander induced by ice loadingJournal of Geophysical Research, Oct. 29, 10.1029/2001JB000889.MantleGeophysics - seismics
DS200512-1097
2005
Sabadini, R.Tosi, N., Sabadini, R., Marotta, A.M., Vermeersen, L.L.A.Simultaneous inversion for the Earth's mantle viscosity and ice mass imbalance in Antarctica and Greenland.Journal of Geophysical Research, Vol. 110, B7, B07402 10.1029/2004 JB003236Europe, GreenlandMantle dynamics
DS201112-0136
2011
Sabadini, R.R.Cambiott, G., Ricard, Y., Sabadini, R.R.New insights into mantle convection true polar wander and rotational bulge readjustment.Earth and Planetary Science Letters, Vol. 310, 3-4, pp. 538-543.MantleConvection
DS1996-1144
1996
Sabaka, T.J.Purucker, M.E., Sabaka, T.J., Langel, R.A.Conjugate gradient analyses - a new tool for studying satellite magneticdat a setsGeophys. Research Letters, Vol. 23, No. 5, March 1, pp 507-510GlobalRemote sensing, Geophysics -magnetics
DS2000-0057
2000
SabateBarbosa, J.S.F., Sabate, Alves Da SilvaGeological and geochronological features of the four Archean crustal segments of Sao Francisco Craton, BahiaIgc 30th. Brasil, Aug. abstract only 1p.Brazil, BahiaTectonics, Craton - Sao Francisco
DS1991-0295
1991
Sabate, P.Conceicao, H., Sabate, P., Bonin, B.The Itiuba alkaline syenite massif, Bahian State, Brasil: geochemical and petrological constraints-relation genesis of rapakivimagmatismPrecambrian Research, Special issue on Precambrian granitoids, Vol. 51, No. 1-4, June pp. 283-314BrazilAlkaline rocks, Itiuba massif
DS1991-1064
1991
Sabate, P.Martin, H., Sabate, P., Peucat, J.J., Cunha, J.C.An early Archean crustal segment (3.4 Ga) -the Sete Voltas Massif (Bahia, Brasil).(in French)Comptes Rendus de la'Academie des Sciences Serie II, Vol. 313, No. 5, August 29, pp. 531-538BrazilArchean, Craton
DS1994-1288
1994
Sabate, P.Nutman, A.P., Cordani, U.G., Sabate, P.SHRIMP uranium-lead (U-Pb) (U-Pb) ages of detrital zircons from the early Proterozoic Contendas-Mirante supracrustal beltJournal of South American Earth Sciences, Vol. 7, No. 2, pp. 109-114Brazil, BahiaGeochronology, Craton -Sao Francisco
DS2002-0100
2002
Sabate, P.Barbosa, J.S.F., Sabate, P.Geological features and the Paleoproterozoic collision of four Archean crustal segments of the Sao Francisco Craton, Bahia: a synthesis.Anais, Academia Brasleira de Ciencias, Vol. 74, No.2., pp.343-60.BrazilTectonics - geodynamics
DS200412-0093
2004
Sabate, P.Barbosa, J.S.F., Sabate, P.Archean and Paleoproterozoic crust of the Sao Francisco Craton, Bahia, Brazil: geodynamic features.Precambrian Research, Vol. 133, 1-2, August 5, pp. 1-27.South America, BrazilGeochemistry, tectonics - not specific to diamonds
DS1975-0609
1977
Sabater, A.Sabater, A., Brannan, P.A.Localization of Probability Zones for Gold and Diamond Prospecting in Venezuelan Guyana Using Radar Imagery, Slar.Venezuela Dir. Geol. Bol. Geological Publishing Esp., No. 7, TOMO 4, PP. 2613-2633.VenezuelaKimberlite, Geophysics
DS201912-2790
2019
Sabatier, P.Jacq, K., Giguet-Covex, C., Sabatier, P., Perrette, Y., Fanget, B., Coquin, D., Debret, M., Arnaud, F.High resolution grain size distribution of sediment core with hyperspectral imaging. ( not specific to diamond)Sedimentary Geology, Vol. 393-394, pdfGlobalhyperspectral

Abstract: The study of sediment cores allows for the reconstruction of past climate and environment through physical-chemical analysis. Nevertheless, this interpretation suffers from many drawbacks that can be overcome with the newest technologies. Hyperspectral imaging is one of these and allows a fast, high resolution, and non-destructive analysis of sediment cores. In this study, we use visible and near-infrared hyperspectral imaging to predict particle size fractions and distribution (PSD) at a resolution of 200??m on a previously well-studied sediment core taken from Lake Bourget (Western Alps, France). These predictions agree with previous studies on this core. Then, the PSD was used to estimate sedimentary deposit sources using the PSD unmixing algorithm AnalySize. It permitted estimation of the contribution of five sources (micrite, small and large bio-induced calcite crystals, diatom frustules, detrital particles), which had previously been characterized. The spatial dimension allowed for laminae to be discretized and counted, in agreement with the age-depth model previously established. We then evaluated the particle size and spectral signatures of each of these annual laminae, hence characterizing their physico-chemical composition. These high-resolution data also allowed for estimation of the accumulation rate (cm/year) of each of the main sources in the laminated unit and inferring the trophic status and the presence of instantaneous events of the lake.
DS2003-1199
2003
Sabau, G.Sabau, G., Massone, H-J.Relationships among eclogite bodies and host rocks in the Lotru metamorphic suite (International Geology Review, Vol. 45, 3, March, pp. 225-262.RomaniaEclogites, Tectonics
DS2003-1200
2003
Sabau, G.Sabau, G., Massonne, H-J.Relationships among eclogite bodies and host rocks in the Lotru metamorphic suite (International Geology Review, Vol. 45, 3, Mar. pp. 225-262.RomaniaBlank
DS200412-1713
2003
Sabau, G.Sabau, G., Massonne, H-J.Relationships among eclogite bodies and host rocks in the Lotru metamorphic suite ( South Carpathians) Romania: petrological eviInternational Geology Review, Vol. 45, 3, Mar. pp. 225-262.Europe, RomaniaEclogite
DS201312-0700
2013
Sabchez-Gomez, M.Perez-Valera, L.A., Rosenbaum, G., Sabchez-Gomez, M., Azor, A., Fernadez-Soler, J.M., Perez-Valera, F., Vasconcelos, P.M.Age distribution of lamproites along the Socovos fault ( southern Spain) and lithospheric scale tearing.Lithos, Vol. 180-181, pp. 252-263.Europe, SpainLamproite
DS1920-0349
1927
Sabin, A.B.Sabin, A.B.Diamond Mining in Central AfricaEngineering and Mining Journal, Vol. 124, PP. 533-534.Democratic Republic of Congo, Central AfricaAlluvial Diamond Placers
DS1998-1274
1998
Sabine, P.A.Sabine, P.A., Howarth, R.J.The role of ternary projections in colour displays for geochemical maps and in economic mineralogy -petrologyJournal of Geochem. Exploration, Vol. 63, No. 2, Sept. pp. 123-144.Ireland, Scotland, WalesGeochemistry - map, Lamprophyres
DS1995-1350
1995
Sabins, F.F.Nielsen, R.L., Mancuso, J.D., Miller, R.A., Sabins, F.F.Use of thematic mapper imagery in generative mineral exploration Central Andes of South AmericaAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint, No. 95-9, 4pChile, Peru, Ecuador, Argentina, BoliviaRemote sensing, Exploration technique
DS1996-1239
1996
Sabins, F.F.Sabins, F.F.Remore sensing: principles and interpretationsW.h. Freeman 3rd. Edition, 494p. approx. 100.00GlobalBook - review, Remote sensing
DS201012-0800
2009
Sabinyan, G.V.Trubetskoy, K.N., Galchenko, Y.P., Ainbinder, L.L., Sabinyan, G.V.Outlook for the enhanced safety and improved efficiency of diamond deposit mining.Journal of Mining Science, Vol. 45, 6, pp. 581-590.RussiaMining - Yakutia pipes
DS200812-0989
2008
Sablokov, S.M.Sablokov, S.M., Sablukova, L.I., Stegnitsky, Y.B., Banzeruk, V.I.Mantle sources for basalt and kimberlite rock bodies with differing age in the Nyurbinskaya pipe ( Nakyn field, Yakutia).9IKC.com, 3p. extended abstractRussia, YakutiaDeposit - Nyurbinskaya geochronology
DS1998-0715
1998
Sablukov, et al.Kaminsky, F.V., Gorzynsky, Sablukova, Sablukov, et al.Primary sources of diamonds in the Birim area, Ghana7th International Kimberlite Conference Abstract, pp. 389-91.GhanaDiamond morphology, alluvials, placers, Deposit - BiriM.
DS1998-0716
1998
Sablukov, et al.Kaminsky, F.V., Sablukova, Sablukov, et al.Diamondiferous minette dykes from the Parker Lake area, Northwest Territories7th International Kimberlite Conference Abstract, pp. 392-4.Northwest TerritoriesMinettes, diamonds, Deposit - Parker Lake
DS1995-1639
1995
Sablukov, L.Sablukov, L., Sablukov, S., Griffin, W.L., O'Reilly, S.Y.Lithosphere evolution in the Archangelsk kimberlite provinceProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 487-489.Russia, ArkangelskGeochemistry -major elements, Deposit -Zolotitsa field, Zimni Bereg
DS201212-0613
2012
Sablukov, L.I.Sablukov, L.I., Sablukova, S.M.,Verichev, E.M., Antonov, A.V.Grospydite xenoliths from Grib pipe, kimberlites ( Arkangelsk Province, Russia).10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, Archangel, Kola PeninsulaDeposit - Grib
DS1995-1639
1995
Sablukov, S.Sablukov, L., Sablukov, S., Griffin, W.L., O'Reilly, S.Y.Lithosphere evolution in the Archangelsk kimberlite provinceProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 487-489.Russia, ArkangelskGeochemistry -major elements, Deposit -Zolotitsa field, Zimni Bereg
DS1984-0623
1984
Sablukov, S.M.Sablukov, S.M.Formation phases and age of the explosion chimney nearOnegaPeninsula.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 277, No. 1, pp. 168-170RussiaPetrology, Diatreme
DS1987-0633
1987
Sablukov, S.M.Sablukov, S.M.Kimberlite volcanic slags.(Russian)Doklady Academy of Sciences Nauk. SSSR, (Russian), Vol. 295, No. 6, pp. 1448-1451IndiaBlank
DS1987-0634
1987
Sablukov, S.M.Sablukov, S.M.Volcanic scoriaceous kimberlite.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 295, No. 6, pp. 1448-1451RussiaKimberlite, Textures
DS1987-0635
1987
Sablukov, S.M.Sablukov, S.M.New dat a on surface forms of kimberlite volcanismDoklady Academy of Sciences Acad. Science USSR Earth SCi. Section, Vol. 282, No. 1-6, pp. 141-143.RussiaKimberlite, volcanism.
DS1988-0589
1988
Sablukov, S.M.Sablukov, S.M.Kimberlite scoriaeDoklady Academy of Science USSR, Earth Science Section, Vol. 295, No. 1-6, Nov. pp. 151-153India, MajhgawanAltered glass, Petrography
DS1990-1287
1990
Sablukov, S.M.Sablukov, S.M.On petrochemical series of kimberlite rocks. (Russian)Dokl. Akad.Nauk SSSR, (Russian), Vol. 313, No. 4, pp. 935-938RussiaPetrography, Kimberlites
DS1995-1640
1995
Sablukov, S.M.Sablukov, S.M.Petrochemical series of kimberlite rocks of Arkhangelsk ProvinceProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 481-483.Russia, ArkangelskPetrochemistry, Deposit -Zimni Bereg, Onega, Terski Bereg, Timan
DS1995-1726
1995
Sablukov, S.M.Shchukin, V.S., Sablukov, S.M.Pecularities of early Gertsinsk tectonic magmatic activization of the eastern European platform north.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 515-517.Russia, ArkangelskTectonic
DS1996-1240
1996
Sablukov, S.M.Sablukov, S.M.Types of volcanic eruptions of the Arkangelsk kimberlite areaInternational Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 389.RussiaDiatremes, Kimberlites
DS1998-0093
1998
Sablukov, S.M.Beard, A.D., Downes, H., Hegner, E., Sablukov, S.M.Mineralogy and geochemistry of Devonian ultramafic minor intrusions of southern Kola Peninsula.Contributions to Mineralogy and Petrology, Vol. 130, pp. 288-303.Russia, Arkangelsk, Kola PeninsulaKimberlites, mellilites, Petrogenesis
DS1998-1536
1998
Sablukov, S.M.Verichev, E.M., Sablukov, S.M., Sablukova, ZhuravlevA new tyoe of Diamondiferous kimberlite of the Zimny Berg area, pipe named after Vladimir Grib.7th International Kimberlite Conference Abstract, pp. 940-2.Russia, ArkangelskStructure, petrography, geochemistry, micaceous, Deposit - Grib
DS2000-0464
2000
Sablukov, S.M.Kaminsky, F.V., Sablukov, S.M., et al.Petrology of kimberlites from the newly discovered Whitefish Lake field inOntario.Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) Calgary May 2000, 4p.Ontario, WawaKimberlite - petrology, age determination, Deposit - Whitefish Lake
DS2000-0849
2000
Sablukov, S.M.Sablukov, S.M., Sablukova, L.I., Shavyrina, M.V.Mantle xenoliths from Zimnii Bereg kimberlite deposits of rounded Arkangelsk Diamondiferous ProvincePetrology, Vol. 8, No. 5, pp. 466-94.Russia, Arkangelsk, Kola PeninsulaXenoliths, diamond morphology, Deposit - Zmnii Bereg
DS2002-0807
2002
Sablukov, S.M.Kaminsky, F.V., Sablukov, S.M., Sablukova, L.I., Shchukin, V.S., Canil, D.Kimberlites from the Wawa area, OntarioCanadian Journal of Earth Sciences, Vol. 39, 12, pp. 1819-38.OntarioPetrology, mineralogy, Deposit - Wawa
DS2003-0684
2003
Sablukov, S.M.Kaminsky, F.V., Sablukov, S.M., Sablukova, I.J., Channer, D.M. DeR.Late Proterozoic kimberlites of Guaniamo, Venezuela: anomalous, ilmenite free mica8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, POSTER abstractVenezuelaDeposit - Guaniamo
DS2003-0685
2003
Sablukov, S.M.Kaminsky, F.V., Sablukov, S.M., Sablukova, L.I.Diamondiferous Archean lamprophyres with komatiitic affinities from the Wawa area8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, POSTER abstractOntario, WawaBlank
DS2003-1201
2003
Sablukov, S.M.Sablukov, S.M., Sablukova, L.I.3 - D mapping of mantle substrate in the Zimny Bereg area, Russia8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, POSTER abstractRussia, ArkangelskBlank
DS2003-1202
2003
Sablukov, S.M.Sablukova, L.I., Sablukov, S.M., Verichev, E.M., Golovin, N.N.Mantle xenoliths of the Grib pipe Zimny Bereg, Russia8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, POSTER abstractRussia, ArkangelskDeposit - Grib
DS2003-1261
2003
Sablukov, S.M.Shchukin, V.S., Sablukov, S.M., Sablukova, L.I., Belousova, E.A., Griffin, V.L.Late Vendian aerial alkaline volcanism in the Winter Coast kimberlite area, Arkangelsk8ikc, Www.venuewest.com/8ikc/program.htm, Session 1 POSTER abstractRussia, ArkangelskKimberlite geology and economics, Deposit - Winter Coast
DS200412-0946
2003
Sablukov, S.M.Kaminsky, F.V., Sablukov, S.M., Sablukova, I.J., Channer, D.M.DeR.Late Proterozoic kimberlites of Guaniamo, Venezuela: anomalous, ilmenite free mica kimberlites of isotopic transitional type.8 IKC Program, Session 7, POSTER abstractSouth America, VenezuelaKimberlite petrogenesis Deposit - Guaniamo
DS200412-0947
2003
Sablukov, S.M.Kaminsky, F.V., Sablukov, S.M., Sablukova, L.I.Diamondiferous Archean lamprophyres with komatiitic affinities from the Wawa area, Ontario, Canada.8 IKC Program, Session 7, POSTER abstractCanada, Ontario, WawaKimberlite petrogenesis
DS200412-1714
2003
Sablukov, S.M.Sablukov, S.M., Sablukova, L.I.3 - D mapping of mantle substrate in the Zimny Bereg area, Russia.8 IKC Program, Session 6, POSTER abstractRussia, Kola Peninsula, ArchangelMantle petrology
DS200412-1715
2003
Sablukov, S.M.Sablukova, L.I., Sablukov, S.M., Verichev, E.M., Golovin, N.N.Mantle xenoliths of the Grib pipe Zimny Bereg, Russia8 IKC Program, Session 6, POSTER abstractRussia, Kola Peninsula, ArchangelMantle petrology Deposit - Grib
DS200512-0845
2005
Sablukov, S.M.Perov, V.A., Bogomolov, E.S., Larchenko, V.A., Levskii, L.K., Minchenko, G.V., Sablukov, S.M., SZergeev, S.A., Stepanov, V.P.Rb Sr age of kimberlites of the Pionerskaya pipe, Arkangelsk Diamondiferous province.Doklady Earth Sciences, Vol. 400, 1, pp. 67-71.Russia, Kola Peninsula, ArchangelGeochronology -
DS200612-1173
2005
Sablukov, S.M.Romanko, E.F., Egorov, N.N., Podvysotskii, V.T., Sablukov, S.M., Dyakonov, D.B.A new Diamondiferous kimberlite region in southwestern Angola.Doklady Earth Sciences, Vol. 403A, 6, pp. 817-821.Africa, AngolaDiamond exploration
DS200612-1197
2005
Sablukov, S.M.Sablukov, S.M., Kaminsky, F.V., Sablukova, L.I.Essentially non-kimberlitic old Diamondiferous igneous rocks.Problems of Sources of deep magmatism and plumes., pp. 188-209.RussiaMetamorphic rocks
DS200612-1198
2006
Sablukov, S.M.Sablukov, S.M., Sablukova, L.I.Intensity of asthenospheric influence as a crucial factor for the diversity of kimberlites.Vladykin: VI International Workshop, held Mirny, Deep seated magmatism, its sources and plumes, pp. 145-158.MantleMagmatism, tectonics
DS200812-0990
2007
Sablukov, S.M.Sablukov, S.M., Sablukova, L.I., Stegnitsky, Yu.B., Banzeruk, V.L.Lithospheric mantle characteristics of the Nakyn field in Yakutia from dates on mantle xenoliths and basalts in the Nyurbinskaya pipe.Vladykin Volume 2007, pp. 140-156.Russia, YakutiaNakyn geochronology
DS200812-0991
2008
Sablukov, S.M.Sablukov, S.M., Sabluokva, L.I.Asthenospheric effect on the mantle substrate and diversity of kimberlite rocks in the Zimni Bereg ( Arkangelsk province).9IKC.com, 3p. extended abstractRussia, Archangel, Kola PeninsulaDeposit - Zimny Bereg, Lomonosov, Zololtisky
DS200912-0357
2009
Sablukov, S.M.Kaminsky, F.V., Sablukov, S.M., Belousova, E.A., Andreazza, P., Tremblay, M., Griffin, W.L.Kimberlite sources of super deep diamonds in the Juin a area, Mato Grosso State, Brazil.Lithos, In press available,South America, Brazil, Mato GrossoKimberlite genesis
DS200912-0358
2009
Sablukov, S.M.Kaminsky, F.V., Sablukov, S.M., Sablukova, L.I., Zakharchenko, O.D.The Fazenda Largo off-craton kimberlites of Piaui State Brazil.Journal of South American Earth Sciences, Vol. 28, 3, pp. 288-303.South America, Brazil, PiauiDeposit - Fazenda
DS201012-0341
2010
Sablukov, S.M.Kaminsky, F.V., Sablukov, S.M., Belousova, E.A., Andreazza, P., Tremblay, M., Griffin, W.L.Kimberlitic sources of super deep diamonds in the Juin a area, Mato Grosso State, Bahia.Lithos, Vol. 114, pp. 16-29.South America, Brazil, Mato GrossoChapadao, Padrea
DS201112-0896
2010
Sablukov, S.M.Sablukov, S.M., Belov, A.V., Sablukova, L.I.The alkaline ultrabasic magmatism of the Onega peninsula Nenoksa fields - reflection (display) of the plume and subduction processes in Belomorsky region.Vladykin, N.V., Deep Seated Magmatism: its sources and plumes, pp. 145-163.Russia, Kola Peninsula, ArchangelSubduction
DS201212-0614
2012
Sablukov, S.M.Sablukov, S.M.TA-SC diagram, the universal discrimination diagram for geochemical classification of the kimberlitic rocks.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, Archangel, Kola PeninsulaDeposit - Zimni Berg
DS201212-0615
2012
Sablukov, S.M.Sablukov, S.M., Sablukova, L.I., Stegnitsky, Y.u., Karpenko, M.A.Banded alkremite xenoliths from Nyurbinskaya kimberlite pipes Nakyn field.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, YakutiaDeposit - Nyurbinskaya
DS201412-0765
2014
Sablukov, S.M.Sablukov, S.M., Sablukova, L.I., Stegnitskiy, Yu.B., Karpenko, M.A.Origin of the mantle xenoliths with green garnets from kimberlites ( dike Newlands, southern Africa and Nyurbinskaya pipe, Yakutia.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., pp. 178-202.RussiaDeposit - Newlands, Nyurbinskaya
DS201510-1801
2014
Sablukov, S.M.Sablukov, S.M., Sablukova, L.I., Stegnitskiy, Yu.B., Karpenko, M.A.Origin of the mantle xenoliths with green garnets from kimberlites ( Dike Newlands, southern Africa and Nyurbinskaya pipe, Yakutia).Deep-seated magmatism, its sources and plumes, Proceedings of XIII International Workshop held 2014., Vol. 2014, pp. 178-202.Africa, South Africa, Russia, YakutiaDeposit - Dike Newlands, Nyurbinskaya

Abstract: Green garnets occur in concentrates of diamondiferous kimberlite bodies in Yakutia (Udachnaya, Mir, etc.), South Africa (Newlands, Bellsbank), Venezuela (Guaniamo sills), and Canada (Mud Lake field). Mantle xenoliths of rocks containing such garnets are very rare. We found peridotite xenoliths with green garnet in situ in kimberlites of the Newlands dike. Xenoliths are irregular in form, 4.5*1.9 cm, 1.5*0.8 cm, and 1.0*0.5 cm in size, and have similar modal compositions: gar(70)+ol(28)+sp(2), gar(9)+ol(90)+sp(1) and gar(50)+ol(30)+sp(20). Rock texture is medium-crystalline, while structure is massive. We also identified a garnet macrocryst of 0.5*0.4 cm in size with a pale green kelyphytic rim. Garnet composition in the studied samples is quite constant and is characterized by the high Cr2O3 content (10.94-11.99%) and CaO content (19.52-24.94%) at the reduced contents of TiO2 (0.24-0.52%). The chrome spinel is high Cr2O3 (55%) content and the low TiO2 (0.5-0.6%) content. Olivine is high-Mg (Fo95), but elevated CaO content (0.09%). Isotopic composition of oxygen in garnet (?18O = 4.05-4.25 pm) and olivine (?18O = 4.91 pm) differs drastically from the mantle values. Rb-Sr and Sm-Nd isotopic composition show the relatively "young" model age of the sample relative to the depleted mantle (1.78 billion years), the age of formation of this rocks is also relatively "young" - probable mezoproterozoic. In kimberlites and placers of the Nyurbinskaya pipe (Nakyn field, Yakutia) there are 4 green garnet grains of 0.5-2.0 mm in size, including one intergrowth gar+sp. Most garnets are characterized by the higher CaO (18.06-22.87%) and TiO2 (1.46, 1.65, 1.75%) contents not noted before for similar garnets. Studied green garnets have the similar "sine wave" type of REE distribution for low-Ti garnets and a "raised" type of REE distribution with enrichment in medium and light REE for high-Ti garnet. All green garnets are characterized by an increased content of light REE and Sc. High-Ti garnets are characterized by an increased content of light and middle REE, as well as titanium, and a particularly sharply increased content of Zr (!). Paragenesis ol+sp is formed at 805oand 23.4 kbar, and paragenesis ol+gar is formed at 1080oand 23.8 kbar. The rocks are characterized by nonequilibrium paragenesis ol+sp+gar and formation at moderate depths (80-90 km) under conditions of high heat flow (52-55 mW/m2). Judging from modal composition of studied xenoliths (absence of clinopyroxene), variations in chemical compositions and trace element compositions, relatively "young" model age and non-mantle isotopy of oxygen in garnets, these rocks are not "wehrlites" and likely represent metasomatic rocks such as uvarovite-chromite veins or schlierens at the moderate depths of upper mantle - it is similar to uvarovite-chromite veins of the metasomatic or a hydrothermal origin in the crustal serpentinites.
DS200512-0922
2002
Sablukov, V.S.Sablukov, V.S., Sablukova, L.I., Verichev, E.M.Essential types of mantle substrate in the Zimny Bereg region in connection with the formation of kimberlite hosting rounded and flat faces diamonds.Deep Seated Magmatism, magmatism sources and the problem of plumes., pp. 185-202.Russia, Kola Peninsula, ArchangelDiamond genesis, morphology
DS1998-0715
1998
SablukovaKaminsky, F.V., Gorzynsky, Sablukova, Sablukov, et al.Primary sources of diamonds in the Birim area, Ghana7th International Kimberlite Conference Abstract, pp. 389-91.GhanaDiamond morphology, alluvials, placers, Deposit - BiriM.
DS1998-0716
1998
SablukovaKaminsky, F.V., Sablukova, Sablukov, et al.Diamondiferous minette dykes from the Parker Lake area, Northwest Territories7th International Kimberlite Conference Abstract, pp. 392-4.Northwest TerritoriesMinettes, diamonds, Deposit - Parker Lake
DS1998-1536
1998
SablukovaVerichev, E.M., Sablukov, S.M., Sablukova, ZhuravlevA new tyoe of Diamondiferous kimberlite of the Zimny Berg area, pipe named after Vladimir Grib.7th International Kimberlite Conference Abstract, pp. 940-2.Russia, ArkangelskStructure, petrography, geochemistry, micaceous, Deposit - Grib
DS2003-0684
2003
Sablukova, I.J.Kaminsky, F.V., Sablukov, S.M., Sablukova, I.J., Channer, D.M. DeR.Late Proterozoic kimberlites of Guaniamo, Venezuela: anomalous, ilmenite free mica8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, POSTER abstractVenezuelaDeposit - Guaniamo
DS200412-0946
2003
Sablukova, I.J.Kaminsky, F.V., Sablukov, S.M., Sablukova, I.J., Channer, D.M.DeR.Late Proterozoic kimberlites of Guaniamo, Venezuela: anomalous, ilmenite free mica kimberlites of isotopic transitional type.8 IKC Program, Session 7, POSTER abstractSouth America, VenezuelaKimberlite petrogenesis Deposit - Guaniamo
DS1995-1641
1995
Sablukova, L.I.Sablukova, L.I.Mantle nodules in kimberlite rocks of ArkhangelskProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 485-486.Russia, ArkangelskMantle nodules, Kimberlites, melilitites, Deposit -Zolotitsa field, Zimni Bereg
DS1996-1241
1996
Sablukova, L.I.Sablukova, L.I.3d mantle mapping of the Arkangelsk kimberlite areaInternational Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 389.RussiaKimberlite, Classifications
DS2000-0849
2000
Sablukova, L.I.Sablukov, S.M., Sablukova, L.I., Shavyrina, M.V.Mantle xenoliths from Zimnii Bereg kimberlite deposits of rounded Arkangelsk Diamondiferous ProvincePetrology, Vol. 8, No. 5, pp. 466-94.Russia, Arkangelsk, Kola PeninsulaXenoliths, diamond morphology, Deposit - Zmnii Bereg
DS2002-0807
2002
Sablukova, L.I.Kaminsky, F.V., Sablukov, S.M., Sablukova, L.I., Shchukin, V.S., Canil, D.Kimberlites from the Wawa area, OntarioCanadian Journal of Earth Sciences, Vol. 39, 12, pp. 1819-38.OntarioPetrology, mineralogy, Deposit - Wawa
DS2003-0685
2003
Sablukova, L.I.Kaminsky, F.V., Sablukov, S.M., Sablukova, L.I.Diamondiferous Archean lamprophyres with komatiitic affinities from the Wawa area8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, POSTER abstractOntario, WawaBlank
DS2003-1201
2003
Sablukova, L.I.Sablukov, S.M., Sablukova, L.I.3 - D mapping of mantle substrate in the Zimny Bereg area, Russia8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, POSTER abstractRussia, ArkangelskBlank
DS2003-1202
2003
Sablukova, L.I.Sablukova, L.I., Sablukov, S.M., Verichev, E.M., Golovin, N.N.Mantle xenoliths of the Grib pipe Zimny Bereg, Russia8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, POSTER abstractRussia, ArkangelskDeposit - Grib
DS2003-1261
2003
Sablukova, L.I.Shchukin, V.S., Sablukov, S.M., Sablukova, L.I., Belousova, E.A., Griffin, V.L.Late Vendian aerial alkaline volcanism in the Winter Coast kimberlite area, Arkangelsk8ikc, Www.venuewest.com/8ikc/program.htm, Session 1 POSTER abstractRussia, ArkangelskKimberlite geology and economics, Deposit - Winter Coast
DS200412-0947
2003
Sablukova, L.I.Kaminsky, F.V., Sablukov, S.M., Sablukova, L.I.Diamondiferous Archean lamprophyres with komatiitic affinities from the Wawa area, Ontario, Canada.8 IKC Program, Session 7, POSTER abstractCanada, Ontario, WawaKimberlite petrogenesis
DS200412-1714
2003
Sablukova, L.I.Sablukov, S.M., Sablukova, L.I.3 - D mapping of mantle substrate in the Zimny Bereg area, Russia.8 IKC Program, Session 6, POSTER abstractRussia, Kola Peninsula, ArchangelMantle petrology
DS200412-1715
2003
Sablukova, L.I.Sablukova, L.I., Sablukov, S.M., Verichev, E.M., Golovin, N.N.Mantle xenoliths of the Grib pipe Zimny Bereg, Russia8 IKC Program, Session 6, POSTER abstractRussia, Kola Peninsula, ArchangelMantle petrology Deposit - Grib
DS200512-0922
2002
Sablukova, L.I.Sablukov, V.S., Sablukova, L.I., Verichev, E.M.Essential types of mantle substrate in the Zimny Bereg region in connection with the formation of kimberlite hosting rounded and flat faces diamonds.Deep Seated Magmatism, magmatism sources and the problem of plumes., pp. 185-202.Russia, Kola Peninsula, ArchangelDiamond genesis, morphology
DS200512-0972
2002
Sablukova, L.I.Shchukin, V.S., Sablukova, S.M., Sablukova, L.I., Belousova,E.A., Griffin, W.L.Late Vendian aerial alkaline volcanism of rift type in the Zimny Bereg kimberlite area, Arkangelsk Diamondiferous province.Deep Seated Magmatism, magmatism sources and the problem of plumes., pp. 203-212.Russia, Kola Peninsula, ArchangelAlkalic
DS200612-1197
2005
Sablukova, L.I.Sablukov, S.M., Kaminsky, F.V., Sablukova, L.I.Essentially non-kimberlitic old Diamondiferous igneous rocks.Problems of Sources of deep magmatism and plumes., pp. 188-209.RussiaMetamorphic rocks
DS200612-1198
2006
Sablukova, L.I.Sablukov, S.M., Sablukova, L.I.Intensity of asthenospheric influence as a crucial factor for the diversity of kimberlites.Vladykin: VI International Workshop, held Mirny, Deep seated magmatism, its sources and plumes, pp. 145-158.MantleMagmatism, tectonics
DS200812-0989
2008
Sablukova, L.I.Sablokov, S.M., Sablukova, L.I., Stegnitsky, Y.B., Banzeruk, V.I.Mantle sources for basalt and kimberlite rock bodies with differing age in the Nyurbinskaya pipe ( Nakyn field, Yakutia).9IKC.com, 3p. extended abstractRussia, YakutiaDeposit - Nyurbinskaya geochronology
DS200812-0990
2007
Sablukova, L.I.Sablukov, S.M., Sablukova, L.I., Stegnitsky, Yu.B., Banzeruk, V.L.Lithospheric mantle characteristics of the Nakyn field in Yakutia from dates on mantle xenoliths and basalts in the Nyurbinskaya pipe.Vladykin Volume 2007, pp. 140-156.Russia, YakutiaNakyn geochronology
DS200912-0358
2009
Sablukova, L.I.Kaminsky, F.V., Sablukov, S.M., Sablukova, L.I., Zakharchenko, O.D.The Fazenda Largo off-craton kimberlites of Piaui State Brazil.Journal of South American Earth Sciences, Vol. 28, 3, pp. 288-303.South America, Brazil, PiauiDeposit - Fazenda
DS201112-0896
2010
Sablukova, L.I.Sablukov, S.M., Belov, A.V., Sablukova, L.I.The alkaline ultrabasic magmatism of the Onega peninsula Nenoksa fields - reflection (display) of the plume and subduction processes in Belomorsky region.Vladykin, N.V., Deep Seated Magmatism: its sources and plumes, pp. 145-163.Russia, Kola Peninsula, ArchangelSubduction
DS201212-0615
2012
Sablukova, L.I.Sablukov, S.M., Sablukova, L.I., Stegnitsky, Y.u., Karpenko, M.A.Banded alkremite xenoliths from Nyurbinskaya kimberlite pipes Nakyn field.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, YakutiaDeposit - Nyurbinskaya
DS201412-0765
2014
Sablukova, L.I.Sablukov, S.M., Sablukova, L.I., Stegnitskiy, Yu.B., Karpenko, M.A.Origin of the mantle xenoliths with green garnets from kimberlites ( dike Newlands, southern Africa and Nyurbinskaya pipe, Yakutia.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., pp. 178-202.RussiaDeposit - Newlands, Nyurbinskaya
DS201510-1801
2014
Sablukova, L.I.Sablukov, S.M., Sablukova, L.I., Stegnitskiy, Yu.B., Karpenko, M.A.Origin of the mantle xenoliths with green garnets from kimberlites ( Dike Newlands, southern Africa and Nyurbinskaya pipe, Yakutia).Deep-seated magmatism, its sources and plumes, Proceedings of XIII International Workshop held 2014., Vol. 2014, pp. 178-202.Africa, South Africa, Russia, YakutiaDeposit - Dike Newlands, Nyurbinskaya

Abstract: Green garnets occur in concentrates of diamondiferous kimberlite bodies in Yakutia (Udachnaya, Mir, etc.), South Africa (Newlands, Bellsbank), Venezuela (Guaniamo sills), and Canada (Mud Lake field). Mantle xenoliths of rocks containing such garnets are very rare. We found peridotite xenoliths with green garnet in situ in kimberlites of the Newlands dike. Xenoliths are irregular in form, 4.5*1.9 cm, 1.5*0.8 cm, and 1.0*0.5 cm in size, and have similar modal compositions: gar(70)+ol(28)+sp(2), gar(9)+ol(90)+sp(1) and gar(50)+ol(30)+sp(20). Rock texture is medium-crystalline, while structure is massive. We also identified a garnet macrocryst of 0.5*0.4 cm in size with a pale green kelyphytic rim. Garnet composition in the studied samples is quite constant and is characterized by the high Cr2O3 content (10.94-11.99%) and CaO content (19.52-24.94%) at the reduced contents of TiO2 (0.24-0.52%). The chrome spinel is high Cr2O3 (55%) content and the low TiO2 (0.5-0.6%) content. Olivine is high-Mg (Fo95), but elevated CaO content (0.09%). Isotopic composition of oxygen in garnet (?18O = 4.05-4.25 pm) and olivine (?18O = 4.91 pm) differs drastically from the mantle values. Rb-Sr and Sm-Nd isotopic composition show the relatively "young" model age of the sample relative to the depleted mantle (1.78 billion years), the age of formation of this rocks is also relatively "young" - probable mezoproterozoic. In kimberlites and placers of the Nyurbinskaya pipe (Nakyn field, Yakutia) there are 4 green garnet grains of 0.5-2.0 mm in size, including one intergrowth gar+sp. Most garnets are characterized by the higher CaO (18.06-22.87%) and TiO2 (1.46, 1.65, 1.75%) contents not noted before for similar garnets. Studied green garnets have the similar "sine wave" type of REE distribution for low-Ti garnets and a "raised" type of REE distribution with enrichment in medium and light REE for high-Ti garnet. All green garnets are characterized by an increased content of light REE and Sc. High-Ti garnets are characterized by an increased content of light and middle REE, as well as titanium, and a particularly sharply increased content of Zr (!). Paragenesis ol+sp is formed at 805oand 23.4 kbar, and paragenesis ol+gar is formed at 1080oand 23.8 kbar. The rocks are characterized by nonequilibrium paragenesis ol+sp+gar and formation at moderate depths (80-90 km) under conditions of high heat flow (52-55 mW/m2). Judging from modal composition of studied xenoliths (absence of clinopyroxene), variations in chemical compositions and trace element compositions, relatively "young" model age and non-mantle isotopy of oxygen in garnets, these rocks are not "wehrlites" and likely represent metasomatic rocks such as uvarovite-chromite veins or schlierens at the moderate depths of upper mantle - it is similar to uvarovite-chromite veins of the metasomatic or a hydrothermal origin in the crustal serpentinites.
DS200512-0972
2002
Sablukova, S.M.Shchukin, V.S., Sablukova, S.M., Sablukova, L.I., Belousova,E.A., Griffin, W.L.Late Vendian aerial alkaline volcanism of rift type in the Zimny Bereg kimberlite area, Arkangelsk Diamondiferous province.Deep Seated Magmatism, magmatism sources and the problem of plumes., pp. 203-212.Russia, Kola Peninsula, ArchangelAlkalic
DS201212-0613
2012
Sablukova, S.M.Sablukov, L.I., Sablukova, S.M.,Verichev, E.M., Antonov, A.V.Grospydite xenoliths from Grib pipe, kimberlites ( Arkangelsk Province, Russia).10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, Archangel, Kola PeninsulaDeposit - Grib
DS200812-0991
2008
Sabluokva, L.I.Sablukov, S.M., Sabluokva, L.I.Asthenospheric effect on the mantle substrate and diversity of kimberlite rocks in the Zimni Bereg ( Arkangelsk province).9IKC.com, 3p. extended abstractRussia, Archangel, Kola PeninsulaDeposit - Zimny Bereg, Lomonosov, Zololtisky
DS1997-0718
1997
Sabu\lukov, Zherdev et al.Makhotkin, I.L., Zhuravlev, Sabu\lukov, Zherdev et al.The plume lithosphere interaction as a geodynamic formation model of the Arkangelsk diamond bearing ProvinceDoklady Academy of Sciences, Vol. 353, No. 2, Feb-Mar, pp. 238-42.Russia, Kola Peninsula, ArkangelskTectonics
DS200512-0847
2005
SabukovPervov, V.A., Bogomolov, E.S., Larchenko, V.A., Levskii, L.K., Minchenko, Sabukov, Sergeev, StepanovRb Sr age of kimberlites of the Pionerskaya pipe, Arkangelsk Diamondiferous province.Doklady Earth Sciences, Vol. 400, 1, pp. 67-71.Russia, Archangel, Kola PeninsulaGeochronology
DS1985-0577
1985
Sabulkov, S.M.Sabulkov, S.M.New Dat a on Superficial Forms of Kimberlite Volcanism Manifestation.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 282, No. 5, PP. 1223-1226..RussiaBlank
DS200512-0923
2003
Sabulkov, S.M.Sabulukova, L.I., Sabulkov, S.M., Verichev, E.M., Golovin, N.N.Petrography and mineral chemistry of mantle xenoliths and xenocrysts from the Grib pipe, Zimny Bereg area, Russia.Plumes and problems of deep sources of alkaline magmatism, pp. 65-95.Russia, Kola Peninsula, ArchangelXenoliths - Grib
DS200812-0992
2008
Sabulov, S.M.Sabulov, S.M., Sabulukova, L.I., Stegnitsky, Yu.B., Karpenko, M.A., Spivakov, S.V.Volcanic rocks of the Nyurbinskaya pipe: a portrayal of regional upper mantle evolution from the Riphean to the Carboniferous time, and its geodynamic relationship.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., 2008 pp. 71-103.Russia, SiberiaDeposit - Nyurbinskaya
DS1992-1318
1992
Sabulukov, S.M.Sabulukov, S.M.On the petrochemical series of kimberlite rocksDoklady Academy of Science USSR, Earth Science Section, Vol. 313, No. 106, June pp. 197-200RussiaKimberlite, Geochemistry
DS200712-0286
2007
Sabulukov, S.M.Egorov, K.N., Ramnko, E.F., Podvysotsky, V.T., Sabulukov, S.M., Garanin, V.K., Dyakonov, D.B.New dat a on kimberlite magmatism in southwestern Angola.Russian Geology and Geophysics, Vol. 48, 4, pp. 323-336.Africa, AngolaMagmatism - kimberlites
DS200512-0923
2003
Sabulukova, L.I.Sabulukova, L.I., Sabulkov, S.M., Verichev, E.M., Golovin, N.N.Petrography and mineral chemistry of mantle xenoliths and xenocrysts from the Grib pipe, Zimny Bereg area, Russia.Plumes and problems of deep sources of alkaline magmatism, pp. 65-95.Russia, Kola Peninsula, ArchangelXenoliths - Grib
DS200812-0992
2008
Sabulukova, L.I.Sabulov, S.M., Sabulukova, L.I., Stegnitsky, Yu.B., Karpenko, M.A., Spivakov, S.V.Volcanic rocks of the Nyurbinskaya pipe: a portrayal of regional upper mantle evolution from the Riphean to the Carboniferous time, and its geodynamic relationship.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., 2008 pp. 71-103.Russia, SiberiaDeposit - Nyurbinskaya
DS1996-0175
1996
Saccani, E.Brigatti, M.F., Medici, L., Saccani, E., Vaccaro, C.Crystal chemistry and petrologic significance of iron rich phlogopite From the Tapira carbonatite complex.American Mineralogist, Vol. 81, July-Aug. pp. 913-927.BrazilCarbonatite, Deposit -Tapira
DS201312-0741
2013
Sacchez-Gomez, M.Reolid, M., Sacchez-Gomez, M., Abad, I., Gomez-Sanchez, M.E., de Mora, J.Natural monument of the Volcano of Cancarix, Spain: a case of lamproite phreatomagmatic volcanism.Geoheritage, Vol. 5, 1, pp. 35-45.Europe, SpainLamproite
DS201602-0198
2015
Sacchi, M.D.Chen, Y., Gu, Y.J., Dokht, R.M.H., Sacchi, M.D.Crustal imprints of Precambrian orogenesis in western Laurentia.Journal of Geophysical Research, Vol. 120, 10, pp. 6993-7012.Canada, AlbertaGeophysics - seismics LVZs

Abstract: Crustal low-velocity zones (LVZs) have been reported in active orogens such as the Himalayas and the Andes but rarely in stable cratonic regions. In this study, we provide compelling evidence for a significant midcrustal LVZ beneath eastern-central Alberta, an integral part of the Precambrian Canadian Shield covered by thick Phanerozoic sedimentary deposits. This 200?km wide, over 10?km thick midcrustal LVZ is well resolved by shear velocity inversions using P-to-S receiver functions from more than 4600 earthquakes. It is generally overlain by a high-velocity upper crust in the depth range of 8-15?km, especially in western-central Alberta, which coincides with the previously documented Winagami reflection sequence. We interpret the LVZ to be of granitic composition, potentially in connection with the crystallization of partially molten crust during the Paleoproterozoic eon. In addition to the Precambrian tectonic history of western Laurentia, which featured plate convergence conducive to crustal melting, our crustal model is further supported by (1) a moderate spatial correlation between the LVZ and heat flow, and (2) shear velocities consistent with that of granite. The well preserved Winagami reflection sequence and the LVZ are potential evidence of distinct episodes of magmatism and crust modification in the Precambrian basement of the Western Canada Sedimentary Basin. The existence of a broad crustal LVZ suggests extensive subduction, orogenesis, and crustal melting during the Precambrian assembly of the North American craton.
DS201912-2777
2019
Sacco, D.Desrosiers, P., Ward, B.C., Sacco, D., Elliott, B.The effect of post depositional meltwater processes on kimberlite indicator mineral concentrations in glacial sediments.Yellowknife Forum NWTgeoscience.ca, abstract volume poster p.105-106.Canada, Northwest Territoriesdrift prospecting

Abstract: In the glaciated terrain of the Northwest Territories, successful diamond exploration projects depend on the implementation of drift prospecting. Drift prospecting combines surficial sediment sampling with an understanding of glacial sediment transport history so that geochemical anomalies can be properly interpreted. However, deglacial meltwater processes that may rework, erode, transport, and deposit previously emplaced till are commonly overlooked or misidentified in sample collection and data interpretation. Exactly how deglacial meltwater processes affect the concentration of kimberlite indicator minerals in glacial sediments is poorly understood. The aim of this study is to determine if syn- and post-depositional meltwater processes affect kimberlite indicator mineral concentrations and distributions. The study area is approximately 225 km2, located in the Winter Lake area, in the southern Slave region. This area was chosen for its multiple subglacial meltwater corridors with numerous meltwater related landforms adjacent to relatively unmodified till. It is a prospective area for kimberlites based on the kimberlite indicator minerals identified during previous till sampling programs. The project incorporates terrain mapping, fieldwork and geochemical analysis. Progress so far includes a desktop study using existing air photos and surficial maps of the region and fieldwork. Stereo image visualization and mapping software (Summit EvolutionTM) combined with digital air photos of the area were utilized to complete a preliminary 1:10 000 scale digital terrain map. Fieldwork was completed in the summer of 2019: the nature and distribution of surficial materials were described, ice flow indicators identified and recorded, and surficial material samples collected. Sampling targeted sediments that experienced varying degrees of meltwater modification; materials collected cover the spectrum from unmodified till to washed till to sorted glaciofluvial sand and gravel. Analysis and interpretation are ongoing. Clast shape and lithology analysis has been completed. Grain size analysis will be completed for the presentation. Samples have been sent to commercial labs for geochemical analysis of the silt and clay fraction as well as heavy mineral separation followed by picking of kimberlite, base metal and gold indicator minerals. Potential kimberlite indicator minerals will be analyzed by electron microprobe to verify the mineralogy; their chemistry will be related to diamond potential. The results of these analysis will not be available in time for the presentation. Field descriptions and photogrammetry indicate that many meltwater corridors contain hummocks and elongate ridges composed of diamicton that is sandier and contains less silt than an unmodified till. The morphology and directionality of these identified landforms suggest they are not esker segments. Comparison of grain size, clast shape and lithology data between till and modified sediments will be related to landform genesis. The observations of surficial materials, landforms and ice flow indicators are being used to update the preliminary 1:10 000 scale terrain map of the area, as well as to interpret the local glacial history of the study area. The results of this project will have significant implications in the planning and execution of diamond exploration programs in the Northwest Territories as well as in effectively interpreting the results of drift prospecting campaigns.
DS202010-1873
2020
Sacco, D.Sacco, D.Drift prospecting for kimberlite in the Slave geological Province: why your KIM-bearing sediment samples may not lead you to kimberlite.Vancouver Kimberlite Cluster, Sept. 30, 1p. AbstractCanada, Northwest territoriesgeochemistry

Abstract: Drift prospecting has been used for decades in the Slave Geological Province, NWT, to identify kimberlite indicator mineral and geochemical dispersals. These dispersals, in conjunction with geophysics and drilling, have led to many kimberlite discoveries. The sources of most well-defined dispersal patterns have been identified, and exploration must now focus on inauspicious regions where primary dispersal from kimberlite has been obscured by post-depositional changes to the landscape. Detailed surficial interpretations from readily available, high-resolution imagery and digital elevation data are a powerful asset when working in these challenging environments. Interpretations tailored to exploration provide the necessary context to unravel the complexities in the surficial geology and reconcile complex dispersal patterns. This presentation will demonstrate how the understanding and recognition of unique depositional environments and post-depositional modification of sediments can provide new insight into historical data, reduce the effort and resources required to collect new high-quality samples and inform data evaluations, ultimately providing lower-risk exploration targets.
DS201512-1945
2015
Sacco, D.A.McKillop, R.J., Sacco, D.A.Using property scale surficial geology mapping to refine kimberlite indicator mineral dispersal patterns at the Redemption project, NWT.43rd Annual Yellowknife Geoscience Forum Abstracts, abstract p. 64.Canada, Northwest TerritoriesDeposit - Redemption

Abstract: Surficial sediment (e.g., till) sampling is an effective tool for mineral exploration in the glaciated landscapes of Canada. Dispersal patterns identified through surficial sampling are studied and used to identify their smaller, mineralized bedrock sources. Data compiled from multiple sampling programs, such as those included in the Kimberlite Indicator and Diamond Database (KIDD), can produce misleading dispersal patterns due to variability in sampling and analysis protocols. The accurate delineation of dispersal patterns requires an understanding of the genesis, comparability and distribution of sediment samples on which the dispersal patterns are based. Using an example from a recent study of the South Coppermine indicator mineral train on the Redemption Project, we demonstrate a method for reducing the variability in the data set that utilizes property-scale surficial geology mapping to systematically filter and normalize the data. The surficial geology mapping identified the nature and distribution of sediments, as well as specific till units that have been reworked to differing degrees by a combination of glacial meltwater, modern drainage and periglacial processes, which can affect the concentration of kimberlite indicator minerals (KIMs). A derivative map depicting till sampling suitability based on basal till potential and the level of reworking was used to classify and group samples into subset populations, from which less-favourable samples were filtered. KIM counts in the remaining sample data were then leveled (normalized) according to the thickness of the sampled till unit to reduce the bias produced by higher anomalies common to thin till units. The filtered and normalized data produced a sharper, more accurate KIM dispersal pattern and a new basis for interpreting possible provenance envelopes, from which lower-risk exploration targets can be identified.
DS201512-1946
2015
Sacco, D.A.McKillop, R.J., Turner, D.G., Sacco, D.A.Quaternary geology interpretation for the Slave surficial materials and permafrost study.43rd Annual Yellowknife Geoscience Forum Abstracts, abstract p. 65.Canada, Northwest TerritoriesGeomorphology

Abstract: The Northwest Territories Geological Survey recently funded a strategic overburden drilling program in the Lac de Gras (NTS 076D) and Alymer Lake (NTS 076C) map areas of the Slave Province, Northwest Territories. This program was designed to help stimulate mineral exploration, and to collect permafrost and geotechnical data required for future infrastructure development. To provide guidance for the drill program and a basis for interpreting the results, we compiled, analyzed and interpreted an unprecedented collection of privately-collected and public data. The data set included extensive LiDAR-derived hillshade models; regional surficial and bedrock geology mapping; and mineralogical, geochemical, grain size and sample description data from surface sediment (till) samples. Our systematic mapping of the LiDAR coverage area resulted in the identification of 649 linear features, including eskers, meltwater channels, moraines, paleo-shorelines and streamlined bedforms, which strengthened understanding of local ice flow histories and patterns of deglaciation. Based on a comprehensive review and re-evaluation of the data, we identified six important trends: (1) samples collected from till blankets have lower indicator mineral counts than those collected from till veneers and thick, hummocky till deposits; (2) indicator mineral counts from glaciofluvial sediments were lower and show more subtle anomalies than those from till; (3) the =0.5 mm size-fraction in the mineralogy data set has ~25-40% higher indicator mineral counts than the >0.5 mm size-fraction; (4) when comparing the analytical results of different size fractions, Cr and La concentrations are higher in the clay-sized fraction, while Ba concentrations are higher in the silt- and clay-sized fraction; (5) anomalous Au concentrations in the northern portion of the study area likely represent a lithological change and subsequent glacial dispersion, rather than significant mineralization; and (6) local variations in pyrope and Cr-diopside counts in the study area may affect interpretations of kimberlite indicator mineral dispersal plumes. We also delineated 60 areas of interest that present unique research opportunities, or represent important data gaps that compromise the understanding of glacial history, mineral dispersal and permafrost conditions within the region.
DS201712-2726
2017
Sacco, D.A.Sacco, D.A., McKillop, R.J., Ward, B.C.Why your kim-bearing till samples may not be leading you to kimberlite.45th. Annual Yellowknife Geoscience Forum, p. 70 abstractCanada, Northwest Territoriesgeochemistry - indicator minerals

Abstract: Kimberlite indicator mineral (KIM) concentrations in till are commonly used in glaciated areas such as Northwest Territories to identify glacial dispersal from a kimberlitic source. However, sampling of till that has been modified by post-depositional processes, or material that is not till, can obscure the original glacial dispersion and mislead exploration efforts. The recognition of subtle changes in material type or the occurrence of till modification is obstructed by periglacial processes that homogenize the landscape. Due to restrictions of scale, it is nearly impossible to identify and represent these subtle landscape variations in regional-scale surficial mapping. The uniform till cover depicted in the regional mapping does not reflect reality, and therefore does not provide the necessary surficial context to inform till sampling programs and evaluation efforts. The Northwest Territories Geological Survey and several private exploration companies have recognized the importance of identifying differences in material type and processes that can remobilize and alter the composition of till. Recent improvements in the availability of high-resolution imagery and digital elevation data have provided the means to perform more detailed surficial studies at a scale that is more applicable to diamond exploration. As a result, multiple high-resolution surficial mapping and associated sediment sample data evaluations have been initiated in and around the Lac de Gras region. These studies have reinforced that there is significant spatial variation in the suitability for till sampling, and found that subglacial meltwater corridors and glacial lakes were common. Furthermore, a many of the previously collected till samples were affected by these processes, which can have a significant influence on KIM concentrations and the shape of their dispersal patterns. Meltwater can truncate dispersals and concentrate heavy minerals. Glacial lakes can either dilute or concentrate heavy minerals depending on whether the environment was proximal or distal. Specific landform assemblages and characteristics have been documented that can be used to identify these dispersal-modifying processes, and used to produce a surficial context that is more suitable to exploration. This improved surficial context facilitates the collection of in situ till samples and the interpretation of existing surface sediment data resulting in lower-risk exploration targets.
DS201812-2877
2018
Sacco, D.A.Sacco, D.A., White, D., McKillop, R.Re-thinking diamond exploration tactics in the Slave Province: a surficial geology perspective. Lac de Gras area2018 Yellowknife Geoscience Forum , p. 66-67. abstractCanada, Northwest Territoriesgeochemistry

Abstract: It took several decades to develop the necessary understanding of glaciation, geochemistry and mineralogy to refine exploration strategies and find the first kimberlite in the Northwest Territories, Canada. These fundamental drift prospecting strategies followed by geophysics and drilling have been used to locate many kimberlite occurrences over the years. Indicator minerals in surface sediments are still the primary datasets used to identify kimberlite exploration targets; however, many of the kimberlite sources for the well-defined indicator mineral dispersals have been identified. Exploration must now focus on regions with more complex surficial geology where primary dispersal patterns in till are obscured by post-depositional modification. These patterns are largely defined using data from historical “˜till' surveys that often failed to properly scrutinize the sample media; reworked tills and other surficial materials were commonly collected. The regional surficial geology maps (e.g., 1:50,000 to 1:250,000) typically published by geological surveys to stimulate reconnaissance exploration in new areas are generally incapable of providing sufficient resolution to determine the genesis and post-glacial alteration of sample media or reconcile complex dispersal patterns. Furthermore, advances in analytical methods have yielded compiled datasets with results from multiple methods that are not always comparable. Without a new, more detailed and systematic approach to evaluating surface sediment data, exploration in areas with complex glacial, deglacial and post-glacial histories will be challenged to discover kimberlite. The accessibility, quality and variety of high-resolution aerial or satellite imagery and topographic data has improved significantly over the years, affording a more detailed interpretation of the surficial environment. These detailed interpretations have allowed us to evaluate historical data with a new perspective and target the collection of new, high-quality data. Throughout the Slave Province, we have tailored surficial interpretations to distinguish in-situ till from reworked till and other materials, which have altered dispersion and indicator mineral concentrations. Using examples from the Lac de Gras area, this presentation demonstrates how a detailed surficial framework, combined with an understanding of the varied analytical methods, is applied to historical datasets to refine indicator dispersal patterns and identify new exploration targets. By standardizing the data based on sediment genesis and transport mechanisms, the dataset becomes more suitable for statistical evaluation and anomaly threshold determinations that are unique to specific data subpopulations. As a result, anomaly contrasts are improved, and complex dispersals can be unravelled. In addition, areas with insufficient data coverage are identified and the necessary framework to complete informed, efficient infill or new sampling is provided. The examples we share highlight that there is no replacement for project-scale understanding of surficial geology and its varied effects on mineral dispersals in the development and interpretation of a surface sediment dataset used to identify kimberlite exploration targets.
DS200612-1475
2006
Saced, A.Veevers, J.J., Belousova, E.A., Saced, A., Sircombe, K., Cooper, A.F., Read, S.E.Pan-Gondwanaland detrital zircons from Australia analyzed for Hf isotopes and trace elements reflect an ice covered Antartic provenance 700-500 Ma alkalinityEarth Science Reviews, in press,AustraliaGeochronology, trace elements
DS202106-0968
2021
Sacek, V.Salazar-Mora, C., Sacek, V.Lateral flow of thick continental lithospheric mantle during tectonic quiescence.Journal of Geodynamics, Vol. 146, 101830, 9p. PdfMantlecraton

Abstract: The amalgamation of continental blocks naturally results in a lithosphere with lateral variations in thickness due to the juxtaposition of thicker cratonic and thinner orogenic lithospheres, which in turn evolve together through time. After the amalgamation, this mosaic of continental blocks can experience longstanding periods of relative tectonic quiescence until the next tectonic event, for instance continental rifting. Using geodynamic numerical models, we explored the internal deformation of the continental lithosphere during periods of tectonic quiescence taking into account lateral variations of lithospheric thickness. We observed that the orientation of lateral flow of the thick cratonic lithosphere depends primarily on the compositional density contrasts (??) between the asthenosphere and continental lithospheric mantle and on the width of the juxtaposed mobile belt lithosphere. In the case of mobile belts wider than 300 km, the margin of the thick craton flows towards (or underplates) the base of the thin lithosphere when ?? ? 32?48 kg/m3, whereas for smaller ?? values, the thick cratonic margin flows away from mobile belt, preserving a sharp thickness variation. For mobile belts narrower than 300 km, the ?? threshold between underplate or outward behavior decreases with the mobile belt width. Underplating of cratonic lithosphere beneath the thin lithosphere is efficient in mobile belts narrower than 300 km and for higher ??, which allows them to cool, thicken and stiffen. Lateral flow of cratonic lithosphere is not efficient to underplate wide mobile belts thoroughly, so the latter are influenced by asthenospheric heat for prolonged periods and thus remain less rigid. Therefore, we propose that protracted tectonic quiescence of supercontinents can develop lithospheric rheological inheritances that may or may not facilitate post-quiescence continental lithospheric rifting.
DS200612-0423
2006
Sacena, S.K.Ganguly, J., Sacena, S.K., Freed, A.M.Density variation in subducting slabs and surrounding upper mantle: understanding stagnation vs penetration of the slabs at 670 km discontinuity.International Mineralogical Association 19th. General Meeting, held Kobe, Japan July 23-28 2006, Abstract p.102.MantleSubduction
DS200412-1716
2004
Sachan, H.K.Sachan, H.K., Mukherjee, B.K., Ogasawara, Y., Mauyama, S., Ishida, H., Muko, A., Yoshioka, N.Discovery of coesite from Indus Suture Zone (ISZ) Ladakh India: evidence for deep subduction.European Journal of Mineralogy, Vol. 16, 2, pp. 235-240.IndiaSubduction
DS201704-0637
2017
Sachdeva, K.Lucas, A., Bhatt, N., Singhania, M., Sachdeva, K., Hsu, T., Padua, P.Jaipur India: the global gem and jewelery power of the pink city. Emerald, Tanzanite Gems & Gemology, Vol. 52, 4, pp. 332-367.IndiaGemstones - emerald, tanzanite

Abstract: In 2015, a field team from GIA visited the Indian city of Jaipur to capture the full scope of its gem and jewelry industry: colored stone cutting, wholesale trading, jewelry design, manufacturing, and retail. The authors documented the current state of the industry from a manufacturing as well as a business perspective. The results substantiated many of the team's prior assessments but also brought to light recent developments with far-reaching effects. The impact of vertical integration, consolidation, globalization, and jewelry television retail far exceeded expectations. Once known as a colored stone manufacturing center, Jaipur has rapidly climbed the value chain into jewelry manufacturing and retail by successfully incorporating experience and tradition with technology and innovation.
DS1960-1018
1968
Sachdeva, O.P.Sachdeva, O.P.A Preliminary Report on a Study of the Diamond Mining Industry Around Panna, with Particular References to the Diamond Mining Project of N.m.d.c.India Geological Survey, UNKNOWN.IndiaMineral Economics
DS1970-0403
1971
Sachdeva, O.P.Sachdeva, O.P.The Development of Diamond Mining Industry at Panna, its Problems and Possibilities of Lines of Approach.India Geological Survey Miscellaneous Publishing, No. 19, PP. 153-162.IndiaMining Economics
DS1995-1642
1995
Sachdeva, O.P.Sachdeva, O.P.Investment in India's mining sector... brief extract from paperWorld Mining Congress on Investment in Asia held May, 3p.IndiaDiamond section -production
DS1995-1643
1995
Sachdeva, O.P.Sachdeva, O.P.Investment in India's mining sectorWorld Mining Congress, Institute International Research held May, 49pIndiaEconomics -investment
DS1995-1644
1995
Sachdeva, O.P.Sachdeva, O.P.Investment opportunities in India's mining sectorAjm Asia/pacific Mining Yearbook, 1995, pp. 152-160IndiaEconomics, Mining
DS200612-1209
2006
Sachikocher, A.Salters, V.J., Blichert Toft, V.J., Fekiacova, J., Sachikocher, A., Bizimis, M.Isotope and trace element evidence for depleted lithosphere in the source of enriched Kolau basalts.Contributions to Mineralogy and Petrology, Vol. 151, 3, pp. 297-312.RussiaGeochronology
DS1991-1129
1991
Sachs, P.M.Mengel, K., Sachs, P.M., Stosch, H.G., Worner, G., Loock, G.Crustal xenoliths from Cenozoic volcanic fields of West Germany:implications for structure and composition of the continental crustTectonophysics, Vol. 195, No. 2-4, pp. 271-290GermanyXenoliths, Crust
DS1993-1360
1993
Sachs, P.M.Sachs, P.M., Stange, S.Fast assimilation of xenoliths in magmasJournal of Geophysical Research, Vol. 98, No. B 11, November 10, pp. 19, 741-754.MantleMagma, Xenoliths
DS1993-1361
1993
Sachs, P.M.Sachs, P.M., Stange, S.Fast assimilation of xenoliths in magmasJournal of Geophysical Research, Vol. 98, No. B 11, Nov. 10, pp. 19, 741-754MantleXenoliths, Magma
DS201012-0395
2010
Sachu, T.Koehm, D., Lindenfeld, M., Rumpker, G., Aanyu, K., Haines, S., Passchier, C.W., Sachu, T.Active transgression faults in rift transfer zones: evidence for complex stress fields and implications for crustal fragmentation processes in the western branchInternational Journal of Earth Sciences, Vol. 99, 7, pp. 1633-1642.Africa, East AfricaEast African Rift
DS2001-1202
2001
SAchubert, G.Vidale, J.E., SAchubert, G., Earle, P.S.Unsuccessful initial search for a midmantle chemical boundary with seismicarrays.Geophysical Research Letters, Vol. 28, No. 5, Mar. 1, pp. 859-62.MantleGeophysics - gravity, Geochemistry
DS1984-0624
1984
Sack, R.O.Sack, R.O., Carmichael, I.S.E.(iron, Magnesium)2 and (titanium,aluminum)2 and (magnesium,silicon)2 exchange Reactions between Clino Pyroxenes and Silicate Melts.Contributions to Mineralogy and Petrology, Vol. 85, No. 2, PP. 116-132.GlobalMineral Chemistry
DS1985-0578
1985
Sack, R.O.Sack, R.O., Carmichael, I.S.E.Experimental Constraints on the Genesis of Alkalic Basalt Lavas.Geological Society of America (GSA), Vol. 17, No. 3, P. 189. (abstract.).East Africa, United States, Crazy MountainsKalsilite, Leucite
DS1987-0241
1987
Sack, R.O.Gee, L.L., Sack, R.O.Experimental petrology of melilites-nephelinitesGeological Society of America, Vol. 19, No. 7 annual meeting abstracts, p.673. abstracDemocratic Republic of CongoMelilite
DS1988-0239
1988
Sack, R.O.Gee, L.L., Sack, R.O.Experimental petrology of melilite nephelinitesJournal of Petrology, Vol. 29, pt. 6, December pp. 1233-1255East Africa, HawaiiMt. Nyiragongo, Melilite
DS1991-1483
1991
Sack, R.O.Sack, R.O.Chromian spinels as petrogenetic indicators -thermodynamics And petrological applicationsAmerican Mineralogist, Vol. 76, No. 5-6, May-June pp. 827-847GlobalGeothermometry, Spinels
DS1989-1343
1989
Sacks, I.S.Sato, H., Sacks, I.S., Murase, T., Muncill, G., Fukuyama, H.Qp-melting temperature relation in peridotite at high pressure andtemperature: attenuation mechanism And implications for the mech. prop. of The upper mantleJournal of Geophysical Research, Vol. 94, No. B8, August 10, pp. 10, 647-10, 661GlobalMantle, Peridotite -experimental
DS1997-0600
1997
Sacks, I.S.Kincaid, C., Sacks, I.S.Thermal and dynamical evolution of the upper mantle in subduction zonesJournal of Geophysical Research, Vol. 102, No. 6, June 10, pp. 12, 29-316.MantleSubduction, Geodynamics
DS1990-1288
1990
Sacks, P.E.Sacks, P.E., Secor, D.T.Jr.Kinematics of Late Paleozoic continental collision between Laurentia andGondwanaScience, Vol. 250, December 21, pp. 1702-1705Appalachia, MidcontinentTectonics, Orogeny
DS1997-0991
1997
Sacks, P.E.Sacks, P.E., Nambiar, C.G., Walters, L.J.Dextral Pan-African shear along the southwestern edge of the Achanovilshear belt, constraints on GondwanaJournal of Geology, Vol. 105, No. 2, March pp. 275-284India, GondwanaTectonics, Shear zone
DS1900-0626
1908
Sacramento UnionSacramento UnionGood Diamond Mines in Butte. a South African Expert Visits The Location at Oroville.Sacramento Union., AUGUST 18TH.United States, California, West CoastDiamond Occurrence
DS1994-1512
1994
Sacre, P.Sacre, P.Native title act (1993) C'th - a miner's nightmareAustralian Institute of Mining and Metallurgy (AusIMM) Bulletin, No. 5, Sept. p. 56AustraliaAboriginal, Legal -native title act
DS1995-1645
1995
Saddiqi, O.Saddiqi, O., et al.Paleomagnetisme des peridotites des Beni Bousera (Rif interne, Maroc)consequences pour l'evoltuion mioceneC.r. Academy Of Science Paris, Vol. 321, 11a, pp. 361-368Morocco, Gibralter ArcPaleomagnetism, Peridotites
DS200912-0680
2009
Saddiqi, O.Sebti, S., Saddiqi, O., El Haimer, F.Z., Michard, A., Ruiz, G., Bousquet, R., Baidder, L., Frizonde Lamotte, D.Vertical movements at the fringe of the West African Craton: first zircon fission track datings from the Anti Atlas Precambrian basement, Morocco.Comptes Rendus Geoscience, Vol. 341, no. 1, pp. 71-77.Africa, MoroccoTectonics
DS1860-0269
1876
Sadebeck, A.Rose, G., Sadebeck, A.Ueber die Krystallisation des Diamanten. Nach Hinterlassenen Aufzeichnungen von Gustav Rose: Bearbeitet von Alexander Sadebeck.Berlin: Abh. Ak. Wiss., PP. 85-148.GlobalGemology, Crystallography
DS1986-0696
1986
Sadeghi, A.Sadeghi, A., Steele, K.F.Geochemical orientation survey for carbonatites in central ArkansawGeological Society of America, Vol. 18, No. 3, p. 263. AbstractArkansas, Hot Spring County, Garland County, GrantCarbonatite, Geochemistry
DS1989-1324
1989
Sadeghi, A.Sadeghi, A., Steele, K.F.Use of stream sediment elemental enrichment factors ingeochemical exploration for carbonatite and uranium,Arkansaw,United States (US)Journal of Geochemical Exploration, Special issue - Geochemical Exploration 1987, Vol. 32, pp. 279-286ArkansasCarbonatite, Geochemistry
DS1988-0590
1988
Sadeghi, A.M.Sadeghi, A.M.Use of stream sediments in geochemical exploration for carbonatite and uranium in central ArkansawMsc. Thesis University Of Of Arkansaw, Fayetteville, ArkansasGeochemistry, Carbonatite
DS2003-1203
2003
Sader, J.A.Sader, J.A., Leybourne, M.I., McClenaghan, M.B., Hamilton, S.M.Geochemistry of groundwater from Jurassic kimberlites in the Kirkland Lake and LakeGeological Survey of Canada Open File, No. 4515, 1 CD 26p. $ 26.00Ontario, Kirkland LakeGeochemistry
DS2003-1204
2003
Sader, J.A.Sader, J.A., Leybourne, M.I., McClenaghan, M.B., Hamilton, S.M., RobertsonGroundwater interaction with kimberlites - a geochemical investigation in northeasternExplore ( AEG Newsletter), No. 118, January pp. 1-4.Ontario, Kirkland LakeGeochemistry, Analytical methods and results
DS2003-1205
2003
Sader, J.A.Sader, J.A., Leybourne, M.I., McClenaghan, M.B., Hamilton, S.M., RobertsonField procedures and results of groundwater sampling in kimberlite from drillholes in theGeological Survey of Canada Current Research, 9p.Ontario, Kirkland LakeSampling - geomorphology
DS2003-1206
2003
Sader, J.A.Sader, J.A., Leybourne, M.L., McClenaghan, M.B., Hamilton, S.M., RobertsonKimberlite exploration using aqueous geochemistry - a new exploration methodGeological Association of Canada Annual Meeting, Abstract onlyGlobalTechniues - geochemistry
DS200412-1717
2003
Sader, J.A.Sader, J.A., Leybourne, M.I., McClenaghan, M.B., Hamilton, S.M.Geochemistry of groundwater from Jurassic kimberlites in the Kirkland Lake and Lake Timiskaming kimberlite fields northeastern OGeological Survey of Canada Open File, No. 4515, 1 CD 26p. $ 26.00Canada, Ontario, Kirkland LakeGeochemistry
DS200412-1718
2003
Sader, J.A.Sader, J.A., Leybourne, M.I., McClenaghan, M.B., Hamilton, S.M., Robertson, K.Field procedures and results of groundwater sampling in kimberlite from drillholes in the Kirkland Lake and Lake Temiskaming areGeological Survey of Canada Current Research, 9p.Canada, Ontario, Kirkland LakeSampling - geomorphology
DS200412-1719
2003
Sader, J.A.Sader, J.A., Leybourne, M.L., McClenaghan, M.B., Hamilton, S.M., Robertson, K.Kimberlite exploration using aqueous geochemistry - a new exploration method.Geological Association of Canada Annual Meeting, Abstract onlyTechnologyTechniues - geochemistry
DS200512-0924
2004
Sader, J.A.Sader, J.A., Leybourne, M.I., McClenaghan, B., Sherwood Lollar, B., Hamilton, S.M.Low T serpentinization and the production of hydrogen and methane gas in kimberlites in northeastern Ontario, Canada.Geological Society of America South Central Meeting ABSTRACTS, Vol. 36, 1, p. 28.Canada, Ontario, Kirkland Lake, Lake TemiskamingA4, B30, C14, groundwater interaction
DS200712-0924
2007
Sader, J.A.Sader, J.A., Leybourne, M.I., McClenaghan, M.B., Hamilton, S.Low temperature serpentinization processes and kimberlite groundwater signature Kirkland Lake and Lake Timiskaming kimberlite fields: implications diamond exploration.Geochemistry: Exploration, Environment, Analysis, Vol. 7, 1, pp. 3-21.Canada, Ontario, Kirkland Lake, TimiskamingGeochemistry - diamond exploration
DS201112-0897
2011
Sader, J.A.Sader, J.A., Hattori, K.H., Kong, J.M., Hamilton, S.M., Brauneder, K.Geochemical responses in peat groundwater over Attawapiskat kimberlites, James Bay Lowlands, Canada and their application to diamond exploration.Geochemistry, Exploration, Environment, Analysis:, Vol. 11, pp. 193-210.Canada, Ontario, James Bay LowlandsGeochemistry
DS201312-0769
2013
Sader, J.A.Sader, J.A., Hattori, K., Brauneder, K., Hamilton, S.M.The influence of buried kimberlite on methane production in overlying sediment, Attawapiskat region, James Bay lowlands, Ontario.Chemical Geology, Vol. 360-361, pp. 173-185.Canada, Ontario, AttawapiskatMethane
DS202111-1782
2021
Sader, J.A.Sader, J.A., Harrison, A.L., McClenaghan, M.B., Hamilton, S.M., Clark, I.D.Sherwood Lollar, B., Leybourne, M.I.Generation of high-pH groundwaters and H2 gas by groundwater-kimberlite interaction, northeastern Ontario.The Canadian Mineralogist, Vol. 59, pp. 1261-1276. doi:10.3749/canmin.2000048 pdfCanada, Ontariodeposit - Kirkland Lake

Abstract: We report new isotopic data for H2 and CH4 gases and Sr for groundwater collected from Jurassic Kirkland Lake kimberlites in northern Ontario, Canada. Groundwaters interacting with kimberlites have elevated pH (up to 12.4), are reducing (Eh as low as the H2-H2O couple), are dominated by OH? alkalinity, and have non-radiogenic (mantle) 87Sr/86Sr values (?0.706-0.707). Most significantly, the highest pH groundwaters have low Mg, high K/Mg, and are associated with abundant reduced gases (H2 ± CH4). Open system conditions favor higher dissolved inorganic carbon and CH4 production, whereas under closed system conditions low DIC, elevated OH? alkalinity, and H2 production are enhanced. Hydrogen gas is isotopically depleted (?2HH2 = ?771 to ?801‰), which, combined with ?2HH2O, yields geothermometry temperatures of serpentinization of 5-25 °C. Deviation of H2-rich groundwaters (by up to 10‰) from the meteoric water line is consistent with Rayleigh fractionation during reduction of water to H2. Methane is characterized by ?13CCH4 = ?35.8 to ?68‰ and ?2HCH4 = ?434‰. The origin of CH4 is inconclusive and there is evidence to support both biogenic and abiogenic origins. The modeled groundwater-kimberlite reactions and production of elevated concentrations of H2 gas suggest uses for diamond-production tailings, as a source of H2 for fuel cells and as a carbon sink.
DS200812-0993
2007
Sader, J.S.Sader, J.S., Hamilton, S.M., Hattori, K.H., Braundedr, K.Project unit: 07-32. Surface media geochemical sampling at the Victor kimberlite region, northern Ontario and the Kirkland Lake region northeastern Ontario.Ontario Geological Survey Open File, No. 6213, pp. 19-1-6.Canada, OntarioOverview field work
DS1990-1289
1990
Sadig, A.A.Sadig, A.A., Ahmed, F.Gravity signatures over selected ring complexes in the Sudan, and their tectonic significanceJournal of African Earth Sciences, Vol. 9, No. 3/4, pp. 481-487GlobalGeophysics -gravity, Tectonics
DS201603-0401
2016
Sadki, O.Montero, P., Haissen, F., Mouttaqi, A., Molina, J.F., Errami, A., Sadki, O., Cambeses, A., Bea, F.Contrasting SHRIMP U-Pb zircon ages of two carbonatite complexes from the peri-cratonic terranes of the Reguibat shield: implications for the lateral extension of the West African Craton.Gondwana Research, in press available 13p.Africa, West AfricaCarbonatite

Abstract: The Oulad Dlim Massif of the Western Reguibat Shield contains several carbonatite complexes of previously unknown age. The largest and best studied are Gleibat Lafhouda, composed of magnesiocarbonatites, and Twihinate, composed of calciocarbonatites. Gleibat Lafhouda is hosted by Archean gneisses and schists. It has a SHRIMP U-Th-Pb zircon crystallization age of 1.85 ± 0.03 Ga, a Nd model age of TCR = 1.89 ± 0.03 Ga, and a Sm-Nd age of 1.85 ± 0.39 Ga. It forms part of the West Reguibat Alkaline province. Twihinate, on the other hand, is much younger. It is hosted by Late Silurian to Early Devonian deformed granites and has a zircon crystallization age of 104 ± 4 Ma, which is within error of the age of the carbonatites of the famous Richat Structure in the southwest Reguibat Shield. Like these, the Twihinate carbonatites are part of the Mid-Cretaceous Peri-Atlantic Alkaline Pulse. The Twihinate carbonatites contain abundant inherited zircons with ages that peak at ca. 420 Ma, 620 Ma, 2050 Ma, 2466 Ma, and 2830 Ma. This indicates that their substratum has West African rather than, as previously suggested, Avalonian affinities. It has, however, a Paleoproterozoic component that is not found in the neighboring western Reguibat Shield. The 421 Ma to 410 Ma gneissic granites hosting Twihinate are epidote + biotite + Ca-rich garnet deformed I-type to A-type granites derived from magmas of deep origin compatible, therefore, with being generated in a subduction environment. These granites form a body of unknown dimensions and petrogenesis, the study of which will be of key importance for understanding the geology and crustal architecture of this region.
DS1985-0490
1985
Sadler, P.Neville, S.L., Schiffman, P., Sadler, P.Ultramafic Inclusions in Late Miocene Alkaline Basalts From fry and Ruby Mountains, San Bernardino County, California.American MINERALOGIST., Vol. 70, No. 7-8, PP. 668-677.United States, West Coast, CaliforniaWebsterite, Lherzolite, Harzburgite
DS1983-0479
1983
Sadler, P.M.Neville, S.L., Schiffman, P., Sadler, P.M.New Discoveries of Spinel Lherzolite and Garnet Websterite Nodules in Alkaline Basalts from the South Central Ranges Ofcalifornia.Geological Society of America (GSA), Vol. 15, No. 5, P. 302. (abstract.).United States, California, West CoastMineralogy
DS1989-1460
1989
Sadler, P.M.Strauss, D., Sadler, P.M.Stochastic models for the completeness of stratigraphic sectionsMathematical Geology, Vol. 21, No. 1, January pp. 37-60GlobalComputer, Stratigraphy
DS1996-1605
1996
Sadovskiy, A.M.Zheligovskiy, V.A., Podvigina, O.M., Sadovskiy, A.M.Some properties of crustal structure in California as indicated by topography and bouguer anomalies...Doklady Academy of Sciences, Vol. 336, pp. 15-20.CaliforniaGeophysics -seismics, Tectonics -faulting
DS201604-0590
2015
Sadovsky, A.B.Alexakhin, V.Yu., Bystritsky, V.M., Zamyatin, N.I., Zubarev, E.V., Krasnoperov, A.V., Rapatsky, V.L., Rogov, Yu.N., Sadovsky, A.B., Salamatin, A.V., Salmin, R.A., Sapozhnikov, M.G., Slepnev, V.M., Khabarov, S.V., Razinkov,E.A., Tarasov, O.G., Nikitin,G.M.Detection of diamonds in kimberlite by the tagged neutron method.Nuclear Instruments and Methods in Physics Research Section A., A785, pp. 9-13.TechnologyMethodology

Abstract: A new technology for diamond detection in kimberlite based on the tagged neutron method is proposed. The results of experimental researches on irradiation of kimberlite samples with 14.1-MeV tagged neutrons are discussed. The source of the tagged neutron flux is a portable neutron generator with a built-in 64-pixel silicon alpha-detector with double-sided stripped readout. Characteristic gamma rays resulting from inelastic neutron scattering on nuclei of elements included in the composition of kimberlite are registered by six gamma-detectors based on BGO crystals. The criterion for diamond presence in kimberlite is an increased carbon concentration within a certain volume of the kimberlite sample.
DS1990-1290
1990
Sadowiak, P.Sadowiak, P., Wever, T.Reflection-diffraction seismic pattern at crustal suture zonesTectonics, Vol. 9, No. 6, December pp. 1495-1514GlobalTectonics, Geophysics -seismics
DS1991-1120
1991
Sadowiak, P.Meissner, R., Wever, Th., Sadowiak, P.Continental collisions and seismic signatureGeophysical Journal International, Vol. 105, No. 1, April pp. 15-24United StatesGeophysics -seismics, Tectonics -crust
DS1987-0636
1987
Sadowski, G.R.Sadowski, G.R., Motidome, M.J.Brazilian megafaultsRevista Geologica de Chile, No. 31, pp. 61-75BrazilTectonics, Lineaments, Rifting
DS1994-1513
1994
Sadowski, G.R.Sadowski, G.R., Bettencourt, J.The Greenville Amazon link in the framework of the sweat reconstructionInternational Symposium Upper Mantle, Aug. 14-19, 1994, pp. 103-105.BrazilTectonics, Gondwana, Amazon craton
DS1996-1242
1996
Sadowski, G.R.Sadowski, G.R., Bettencourt, J.S.Mesoproterozoic tectonic correlations between eastern Laurentia and The western border of Amazon CratonPrecambrian Research, Vol. 76, No. 3-4, Feb. 1, pp. 213-GlobalTectonics, Proterozoic
DS1986-0233
1986
Sadykov, I.S.Faizullin, R.M., Sadykov, I.S., Marchenko, E.Ya.A geologic and technological model of the carbonatite type of apatite oredepositsSoviet Geology and Geophysics, Vol. 27, No. 11, pp. 24-31RussiaCarbonatite, Apatite
DS200712-0290
2006
Sadykov, R.Ekimov, E., Sidorov, V., Rakhmaninia, A., Melnik, N., Timofeev, M., Sadykov, R.Synthesis, structure and physical properties of boron doped diamond.Inorganic Materials, Vol. 42, 11, Nov. pp. 1198-1204.TechnologyDiamond mineralogy
DS200612-0500
2006
Saeed, A.Griffin, W.L., Pearson, N.J., Belousova, E.A., Saeed, A.Hf isotope heterogeneity in zircon 91500.... comment.Chemical Geology, Vol. 233, 3-4, Oct. 15, pp. 358-363.TechnologyGeochronology
DS200612-1476
2006
Saeed, A.Veevers, J.J., Belousova, E.A., Saeed, A., Sircombe, K., Cooper, A.F., Read, S.E.Pan Gondwanaland detrital zircons from Australia analysed for Hf isotopes and trace elements reflect an ice covered Antarctic provenance of 700-500 Ma ...Earth Science Reviews, Vol. 76, 3-4, June pp. 135-174.AustraliaGeochronology, alkaline affinity
DS200812-0829
2008
Saeed, A.O'Reilly, S.Y., Griffin, W.L., Pearson, N.J., Jackson, S.E., Belousova, E.A., Alard, O., Saeed, A.Taking the pulse of the Earth: linking crustal and mantle events.Australian Journal of Earth Sciences, Vol. 55, pp. 983-995.MantleGeochronology
DS201909-2102
2019
Saeseaw, S.Vertriest, W., Saeseaw, S.A decade of ruby from Mozambique: a review.Gems & Gemology, Vol. 55, 7, pp. 162-183.Africa, MozambiqueRuby

Abstract: In less than a decade, Mozambique has become the world’s most productive source for gem-quality ruby. Since the discovery in 2009, GIA has followed these deposits from the front lines, collecting data in the field and in the laboratory. The development of the deposit in Montepuez has been extremely interesting, with different players involved and different types of material unearthed. This article provides a summary and overview of the current knowledge about Mozambican ruby, including the history of mining and the market impact, as well as a comprehensive gemological characterization and discussion of the most common treatments applied to the stones. Much of the information in this article is based on the authors’ observations in the field and market as well as several publications (Pardieu et al., 2009, 2013, 2015; Saeseaw et al., 2018).
DS202003-0355
2019
Saeseaw, S.Palke, A.C., Saeseaw, S., Renfro, N.D., Sun, Z., McClure, S.F.Geographic origin of ruby.Gems & Gemology, Vol. 55, 4, pp. 580-579.Global, Asia, Myanmar, Vietnam, Cambodia, Thailand, Africa, Madagascar, Mozambique, Europe, Afghanistanruby

Abstract: Over the last several decades, geographic origin determination for fine rubies has become increasingly important in the gem trade. In the gemological laboratory, rubies are generally broken down into two groups based on their trace element chemistry: marble-hosted (low-iron) rubies and high-iron rubies. High-iron rubies are usually a straightforward identification based on their inclusions and trace element profiles. Marble-hosted rubies can be more challenging, with some deposits showing overlap in some of their inclusion scenes. But many marblehosted rubies, especially Burmese stones from Mogok and Mong Hsu, can be accurately identified based on their internal features and trace element profiles. This contribution will outline the methods and criteria used at GIA for geographic origin determination for ruby.
DS202003-0359
2019
Saeseaw, S.Saeseaw, S., Renfro, N.D., Palke, A.C., Sun, Z., McClure, S.F.Geographic origin of emerald.Gems & Gemology, Vol. 55, 4, pp. 614-647.South America, Colombia, China, Europe, Afghanistan, Africa, Zambiaemerald

Abstract: The gem trade has grown to rely on gemological laboratories to provide origin determination services for emeralds and other fine colored stones. In the laboratory, this is mostly accomplished by careful observations of inclusion characteristics, spectroscopic analysis, and trace element profile measurements by laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS). Inclusions and spectroscopy can often separate Colombian emeralds from other sources (although there is some overlap between Colombian, Afghan, and Chinese [Davdar] emeralds). For non-Colombian emeralds, trace element analysis by LA-ICP-MS is needed in addition to information from the stone’s inclusions. The relative chemical diversity of emeralds from worldwide deposits allows confidence in origin determination in most cases. This contribution outlines the methods and criteria used at GIA for geographic origin determination for emerald.
DS1991-1484
1991
Saether, B.M.Saether, B.M.Advanced techniques for lineament analysisProceedings of the Eighth Thematic Conference on Geologic Remote, Vol. II, pp. 983-988GlobalRemote sensing, Structure
DS1950-0352
1957
Saether, E.Saether, E.The Alkaline Rock Province of the Fen Area in Southern NorwaKong. Norske Vidensk. Selsk. Skr., No. 1, PP. 1-150.Norway, ScandinaviaGeology
DS202101-0022
2020
Safai, A.Kropac, K., Dolnicek, Z., Uher, P., Burianek, D., Safai, A., Urubek, T.Zirconian-niobian titanite and associated Zr-, Nb-, REE-rich accessory minerals: products of hydrothermal overprint of leucocratic teschenites ( Sileasian Unit, outer western Carpathians, Czech Republic).Geologica Carpathica ** Eng, Vol. 71, 4, pp. 343-360. pdfEurope, Czech Republicalkaline rocks

Abstract: Sills of hydrothermally altered alkaline magmatic rock (teschenite) of Lower Cretaceous age at the ?er?ák and ?epišt? sites in the Silesian Unit (Flysch Belt of the Outer Western Carpathians, Czech Republic) host leucocratic dykes and nests which contain accessory minerals enriched in Zr, Nb and REE: Zr-, Nb-rich titanite, zircon, gittinsite, pyrochlore, monazite, REE-rich apatite, epidote, and vesuvianite. Titanite forms wedge-shaped crystals or irregular aggregates enclosed in the analcime groundmass or overgrowths on Zr-rich ferropargasite and taramite or Zr-rich aegirine-augite to aegirine. Titanite crystals show oscillatory or irregular patchy to sector zoning and contain up to 17.7 wt. % ZrO2 and 19.6 wt. % Nb2O5, and ?1.1 wt. % REE2O3. High-field-strength elements (HFSE) are incorporated into the structure of the studied titanite predominantly by substitutions: (i) [6]Ti4+???[6]Zr4+; (ii) [6]Ti4+?+?[6]Al3+???[6]Zr4+?+?[6]Fe3+; and (iii) [6]2Ti4+???[6]Nb5+?+?[6](Al, Fe)3+. Magmatic fractional crystallization, high-temperature hydrothermal autometasomatic overprint and low-temperature hydrothermal alterations resulted in the formation of the HFSE-rich mineral assemblages within the leucocratic teschenites. Autometamorphic processes caused by high-temperature hypersaline aqueous solutions (salinity ~50 wt. %, ~390-510 °C), which were released from the HFSE-enriched residual melt, played a major role in the crystallization of Zr-, Nb-, and REE-rich minerals. The mobilization of HFSE could have occurred either by their sequestration into a fluid phase exsolved from the crystallizing melt or by superimposed alteration processes. The distinctive positive Eu anomaly (EuCN/Eu*?=?1.85) of leucocratic dykes infers possible mixing of Eu2+-bearing magmatic fluids with more oxidized fluids.
DS1996-0254
1996
Safanda, J.Cermak, V., Safanda, J., Kresl, M., Kucerova, L.Heat flow studies in central Europe with special emphasis on dat a from former CzechoslovakiaGlobal Tectonics and Metallogeny, Vol. 5, No. 3-4, p. 109-123GlobalHeat Flow project, volcanism.
DS1998-0922
1998
Safanda, J.Majorowicz, J.A., Safanda, J.Ground surface temperature history from inversions of underground temperatures: case study....Tectonophysics, Vol. 291, No. 1-4, pp. 187-98.Alberta, Western Canada Sedimentary BasinGeothermometry
DS2000-0699
2000
Safarjalani, A.Nasir, S., Safarjalani, A.Lithospheric petrology beneath the northern part of the Arabian Plate in Syria: evidence from xenoliths...Journal of African Earth Sciences, Vol. 30, No. 1, pp. 149-68.SyriaAlkali basalts, Xenoliths - Shamah volcanic fields
DS1860-0088
1869
Safford, J.M.Safford, J.M.Geology of TennesseeNashville: Mercer Publishing, United States, TennesseeGeology
DS1996-1108
1996
SafonovPerchuk, L.L., Gerya, T.V., Van Reenen, D.D., Safonov, SmitThe Limpopo metamorphic belt, South Africa: decompression and cooling regimes of granulites...Petrology, Vol. 4, No. 6, Nov-Dec. pp. 571-599.South AfricaCraton - Kaapvaal, Limpopo metamorphic belt
DS1986-0884
1986
Safonov, A.F.Yegorov, K.N., Kornilova, V.P., Safonov, A.F., Filippov, N.D.Mica kimberlites in the Udachnaya-Vostochnaya pipe. (Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 291, No. 1, pp. 199-202RussiaMica, Deposit -Udachnaya
DS200812-0994
2008
Safonov, O.Safonov, O., Perchuk, L., Litvin, Y., Chertkova, N., Butvina, V.Experimental modeling of chloride bearing diamond related liquids: a review.Goldschmidt Conference 2008, Abstract p.A817.Africa, Botswana, South America, Brazil, Russia, CanadaDiamond inclusions
DS201412-0766
2014
Safonov, O.Safonov, O.The orthopyroxene interaction with the Na-carbonate melt: a challenge of the assimilation-fueled buoyancy mechanism.ima2014.co.za, AbstractMantleMelting
DS202003-0360
2019
Safonov, O.Safonov, O., Butvina, V., Limanov, E.Phlogopite forming reactions as indicators of metasomatism in the lithospheric mantle.Minerals ( MDPI), Vol. 9, 18p. PdfMantlemetasomatism

Abstract: Phlogopite is widely accepted as a major mineral indicator of the modal metasomatism in the upper mantle within a very wide P-T range. The paper reviews data on various phlogopite-forming reactions in upper-mantle peridotites. The review includes both descriptions of naturally occurring reactions and results of experiments that model some of these reactions. Relations of phlogopite with other potassic phases, such as K-richterite, sanidine and K-titanates, are discussed. These data are taken as a basis for thermodynamic modeling of the phlogopite-forming reactions for specific mantle rocks in terms of log(aH2O) ? log(aK2O) diagrams (pseudosections) using the Gibbs free energy minimization. These diagrams allow estimation of potassium-water activity relations during metasomatic transformations of mantle rocks, prediction sequences of mineral assemblages with respect to these parameters and comparison of metasomatic processes in the rocks of different composition. This approach is illustrated by examples from peridotite xenoliths from kimberlites.
DS2002-0157
2002
Safonov, O.G.Bindi, L., Safonov, O.G., Litvin, Y.A., Perchuk, L.L., Menchetti, S.Ultrahigh potassium content in the clinopyroxene structure: an x-ray single crystal studyEuropean Journal of Mineralogy, Vol. 14, 5, pp. 929-34.GlobalMineralogy - not specific to diamond
DS2002-1243
2002
Safonov, O.G.Perchuk, L.L., Safonov, O.G., Yapaskurt, BartonCrystal melt equilibration temperatures involving potassium bearing clinopyroxene as indicator of mantle derived ultrahighLithos, Vol.60, pp. 89-111.MantleMelting - potassic liquids, an analytical review
DS2002-1244
2002
Safonov, O.G.Perchuk, L.L., Safonov, O.G., Yapaskurt, V.O., BartonCrystal melt equilibration temperatures involving potassium bearing clinopyroxene as indicator of mantle derived ultrahighLithos, Vol. 60, No. 3-4, Feb. pp. 89-111.MantleAnalytical review - potassic liquids
DS2002-1379
2002
Safonov, O.G.Safonov, O.G., Malveev, Yu.A., Litvin, Y.A., Perchuk, L.L., Bindi, L., MenchettiUltrahigh pressure study of potassium bearing clinopyroxene equilibria18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.74.Russia, YakutiaUHP, mineralogy, Kokchteav Complex, kimberlites
DS2003-0111
2003
Safonov, O.G.Bindi, L., Safonov, O.G., Yapaskurt, V.O., Perchuk, L.L., Menchetti, S.Ultrapotassic clinopyroxene from the Kumdy Kol microdiamond mine, KokchetavAmerican Mineralogist, Vol. 88, 2-3, Feb.March pp. 464-8.Russia, KazakhstanMineral chemistry, Kokchetav Complex
DS200512-0925
2005
Safonov, O.G.Safonov, O.G., Perchuk, L.L., Litrvin, Y.A., Bindi, L.Phase relations in the Ca Mg Si2O6 K Al Si308 join at 6 and s.5 GPa as a model for formation of some potassium bearing deep seated mineral assemblages.Contributions to Mineralogy and Petrology, Vol. 149, 3, pp. 316-337.Experimental petrology
DS200612-1199
2005
Safonov, O.G.Safonov, O.G., Perchuk, L.L., Litvin, Y.A.Equilibrium K bearing clinopyroxene melt as a model for barometry of mantle derived mineral assemblages.Russian Geology and Geophysics, Vol. 46, 12, pp. 1300-1316.TechnologyGeobarometry
DS200712-0925
2006
Safonov, O.G.Safonov, O.G., Perchuk, L.L., Litvin, Y.A.Melting relations in the chloride carbonate silicate systems at high pressure and model for formation of alkalic diamond forming liquids in the upper mantle.Earth and Planetary Science Letters, in press availableTechnologyUHP, melts, kimberlites
DS200912-0093
2009
Safonov, O.G.Butvina, V.G., Nielsen, T.F.D., Safonov, O.G., Litvin, Yu.A.Experimental study on melting phase relations and diamond formation in the carbonate rich kimberlite from Majugaa southern west Greenland.alkaline09.narod.ru ENGLISH, May 10, 2p. abstractEurope, GreenlandManiitsoq
DS200912-0579
2009
Safonov, O.G.Perchuk, L.L., Safonov, O.G.Carbonatite to kimberlite link in the chloride carbonate silicate system.Goldschmidt Conference 2009, p. A1012 Abstract.MantleGenesis
DS200912-0658
2009
Safonov, O.G.Safonov, O.G., Perchuk, L.L., Yapaskurt, V.O., Litvin, Yu.A.Immiscibility of carbonate silicate and chloride carbonate melts in the kimberlite CaCO3 Na2Co3 KCL system at 4.8 GPa.Doklady Earth Sciences, Vol. 424, 1, pp. 142-146.TechnologyGeochemistry
DS201012-0448
2010
Safonov, O.G.Litasov, K.D., Safonov, O.G., Ohtani, E.Origin of Cl bearing silica rich melt inclusions in diamonds: experimental evidence for an eclogite connection.Geology, Vol. 38, 12, Dec. pp. 1131-1134.TechnologyMelting phase relations, chlorine
DS201012-0573
2009
Safonov, O.G.Perchuk, A.L., Davydova, V.V., Burchard, M., Maresch, W.V., Schertl, H.P., Yapaskurt, V.O., Safonov, O.G.Modification of mineral inclusions in garnet under high pressure conditions: experimental simulation and application to carbonate silicate rocks of KokchetetavRussian Geology and Geophysics, Vol. 50, 12, pp. 1153-1168.RussiaMineralogy
DS201012-0649
2009
Safonov, O.G.Safonov, O.G., Chertkova, L.L., Perchuk, L.L., Litvin, Yu.A.Experimental model for alkalic chloride rich liquids in the upper mantle.Lithos, Vol. 112 S pp. 260-273.MantleAlkaline rocks, chemistry
DS201012-0702
2010
Safonov, O.G.Shiryaev, A.A., Safonov, O.G., Ragozin, A.L.XANES spectroscopy at the potassium K edge of inclusions in kimberlitic diamonds.International Mineralogical Association meeting August Budapest, abstract p. 186.Russia, South America, BrazilSpectroscopy
DS201112-0898
2011
Safonov, O.G.Safonov, O.G.Kamafugite melts as products of interaction between peridotite and chloride carbonate liquids at pressures 1-7 GPa.Doklady Earth Sciences, Vol. 440, 1, pp.TechnologyKamafugite
DS201112-0899
2011
Safonov, O.G.Safonov, O.G., Bindi, L., Vinograd, V.L.Potassium bearing clinopyroxene: a review of experimental, crystal chemical and thermodynamic dat a with petrological applications.Mineralogical Magazine, Vol. 75, 4, August pp. 2467-2484.TechnologyUpper mantle conditions
DS201112-0900
2011
Safonov, O.G.Safonov, O.G., Kamenetsky, V.S., Perchuk, L.L.Links between carbonatite and kimberlite melts in chloride-carbonate-silicate systems: experiments and application to natural assemblages.Journal of Petrology, Vol. 52, 7-8, pp. 1307-1331.TechnologyMelting
DS201611-2139
2016
Safonov, O.G.Sharygin, I.S., Litasov, K.D., Shatskiy, A., Safonov, O.G., Golovin, A.V., Ohtani, E., Pokhilenko, N.P.Experimental constraints on orthopyroxene dissolution in alkali carbonate melts in the lithospheric mantle: implications for kimberlite melt composition and magma ascent.Chemical Geology, in press available 42p.TechnologyMagma melting

Abstract: Although kimberlite magma carries large amounts of mantle-derived xenocrysts and xenoliths (with sizes up to meters), this magma ascends from the Earth's mantle (> 150-250 km) to the surface in a matter of hours or days, which enables diamonds to survive. The recently proposed assimilation-fuelled buoyancy model for kimberlite magma ascent emphasizes the importance of fluid CO2 that is produced via the reactive dissolution of mantle-derived orthopyroxene xenocrysts into kimberlite melt, which initially has carbonatitic composition. Here, we use a series of high-pressure experiments to test this model by studying the interaction of orthopyroxene (Opx) with an alkali-dolomitic melt (simplified to 0.7Na2CO3 + 0.3K2CO3 + 2CaMg(CO3)2), which is close to the melt that is produced by the partial melting of a kimberlite source, at P = 3.1-6.5 GPa and T = 1200-1600 °C, i.e., up to pressures that correspond to depths (~ 200 km) from where the ascent of kimberlite magma would start. During the first set of experiments, we study the reaction between powdered Opx and model carbonate melt in a homogeneous mixture. During the second set of experiments, we investigate the mechanism and kinetics of the dissolution of Opx crystals in alkali-dolomitic melt. Depending on the P-T conditions, Opx dissolves in the alkali-dolomitic melt (CL) either congruently or incongruently via the following reactions: Mg2Si2O6 (Opx) + CaMg(CO3)2 (CL) = CaMgSi2O6 (clinopyroxene) + 2MgCO3 (CL) and Mg2Si2O6 (Opx) = Mg2SiO4 (olivine) + SiO2 (CL). The experiments confirm that the dissolution of Opx causes gradual SiO2 enrichment in the initial carbonate melt, as previously suggested. However, the assimilation of Opx by carbonate melt does not produce fluid CO2 in the experiments because the CO2 is totally dissolved in the evolved melt. Thus, our results clearly demonstrate the absence of exsolved CO2 fluid at 3.1-6.5 GPa in ascending kimberlite magma and disprove the assimilation-fuelled buoyancy model for kimberlite magma ascent in the lithospheric mantle. We alternatively suggest that the extreme buoyancy of kimberlite magma at depths of 100-250 km is an exclusive consequence of the unique physical properties (i.e., low density, ultra-low viscosity and, thus, high mobility) of the kimberlite melt, which are dictated by its carbonatitic composition.
DS201707-1356
2016
Safonov, O.G.Perchuk, A.L., Safonov, O.G., Smit, C.A., van Reenen, D.D., Zkharov, V.S., Gerya, T.V.Precambrian ultra hot orogenic factory: making and reworking of continental crust.Tectonophysics, in press availableMantleUHP

Abstract: Mechanisms of Precambrian orogeny and their contribution to the origin of ultrahigh temperature granulites, granite-greenstone terranes and net crustal growth remain debatable. Here, we use 2D numerical models with 150 °C higher mantle temperatures compared to present day conditions to investigate physical and petrological controls of Precambrian orogeny during forced continental plates convergence. Numerical experiments show that convergence between two relatively thin blocks of continental lithosphere with fertile mantle creates a short-lived cold collisional belt that later becomes absorbed by a long-lived thick and flat ultra-hot accretionary orogen with Moho temperatures of 700–1100 °C. The orogen underlain by hot partially molten depleted asthenospheric mantle spreads with plate tectonic rates towards the incoming lithospheric block. The accretionary orogeny is driven by delamination of incoming lithospheric mantle with attached mafic lower crust and invasion of the hot partially molten asthenospheric wedge under the accreted crust. A very fast convective cell forms atop the subducting slab, in which hot asthenospheric mantle rises against the motion of the slab and transports heat towards the moving orogenic front. Juvenile crustal growth during the orogeny is accompanied by net crustal loss due to the lower crust subduction. Stability of an ultra-hot orogeny is critically dependent on the presence of relatively thin and warm continental lithosphere with thin crust and dense fertile mantle roots subjected to plate convergence. Increased thickness of the continental crust and subcontinental lithospheric mantle, pronounced buoyancy of the lithospheric roots, and decreased mantle and continental Moho temperature favor colder and more collision-like orogenic styles with thick crust, reduced magmatic activity, lowered metamorphic temperatures, and decreased degree of crustal modification. Our numerical modeling results thus indicate that different types of orogens (cold, mixed-hot and ultra-hot) could be created at the same time in the Early Earth, depending on compositional and thermal structures of interacting continental blocks.
DS201707-1364
2017
Safonov, O.G.Sharygin, I.S., Litasov, K.D., Shatskiy, A., Safonov, O.G., Golovin, A.V., Ohtani, E., Pokhilenko, N.P.Experimental constraints on orthopyroxene dissolution in alkali-carbonate melts in the lithospheric mantle: implications for kimberlite melt composition and magma ascent.Chemical Geology, Vol. 455, pp. 44-56.Mantlekimberlite, carbonatite

Abstract: Although kimberlite magma carries large amounts of mantle-derived xenocrysts and xenoliths (with sizes up to meters), this magma ascends from the Earth's mantle (> 150–250 km) to the surface in a matter of hours or days, which enables diamonds to survive. The recently proposed assimilation-fuelled buoyancy model for kimberlite magma ascent emphasizes the importance of fluid CO2 that is produced via the reactive dissolution of mantle-derived orthopyroxene xenocrysts into kimberlite melt, which initially has carbonatitic composition. Here, we use a series of high-pressure experiments to test this model by studying the interaction of orthopyroxene (Opx) with an alkali-dolomitic melt (simplified to 0.7Na2CO3 + 0.3K2CO3 + 2CaMg(CO3)2), which is close to the melt that is produced by the partial melting of a kimberlite source, at P = 3.1–6.5 GPa and T = 1200–1600 °C, i.e., up to pressures that correspond to depths (~ 200 km) from where the ascent of kimberlite magma would start. During the first set of experiments, we study the reaction between powdered Opx and model carbonate melt in a homogeneous mixture. During the second set of experiments, we investigate the mechanism and kinetics of the dissolution of Opx crystals in alkali-dolomitic melt. Depending on the P-T conditions, Opx dissolves in the alkali-dolomitic melt (CL) either congruently or incongruently via the following reactions: Mg2Si2O6 (Opx) + CaMg(CO3)2 (CL) = CaMgSi2O6 (clinopyroxene) + 2MgCO3 (CL) and Mg2Si2O6 (Opx) = Mg2SiO4 (olivine) + SiO2 (CL). The experiments confirm that the dissolution of Opx causes gradual SiO2 enrichment in the initial carbonate melt, as previously suggested. However, the assimilation of Opx by carbonate melt does not produce fluid CO2 in the experiments because the CO2 is totally dissolved in the evolved melt. Thus, our results clearly demonstrate the absence of exsolved CO2 fluid at 3.1–6.5 GPa in ascending kimberlite magma and disprove the assimilation-fuelled buoyancy model for kimberlite magma ascent in the lithospheric mantle. We alternatively suggest that the extreme buoyancy of kimberlite magma at depths of 100–250 km is an exclusive consequence of the unique physical properties (i.e., low density, ultra-low viscosity and, thus, high mobility) of the kimberlite melt, which are dictated by its carbonatitic composition.
DS201709-1962
2017
Safonov, O.G.Borisova, A.Y., Zagrtdenov, N.R., Toplis, M.J., Bohrson, W.A., Nedelec, A., Safonov, O.G., Pokrovski, G.S., Ceileneer, G., Melnik, O.E., Bychkov, A.Y., Gurenko, A.A., Shscheka, S., Terehin, A., Polukeev, V.M., Varlamov, D.A., Gouy, S., De Parseval, P.Making Earth's continental crust from serpentinite and basalt. Goldschmidt Conference, abstract 1p.Mantleperidotites

Abstract: How the Earth's continental crust was formed in the Hadean eon is a subject of considerable debates [1-4]. For example, shallow hydrous peridotites [2,5], in particular the Hadean Earth's serpentinites [6], are potentially important ingredients in the creation of the continental ptoto-crust, but the mechanisms of this formation remain elusive. In this work, experiments to explore serpentinite-basalt interaction under conditions of the Hadean Earth were conducted. Kinetic runs lasting 0.5 to 48 hours at 0.2 to 1.0 GPa and 1250 to 1300°C reveal dehydration of serpentinite and release of a Si-Al-Na-K-rich aqueous fluid. For the first time, generation of heterogeneous hydrous silicic melts (56 to 67 wt% SiO2) in response to the fluid-assisted fertilisation and the subsequent partial melting of the dehydrated serpentinite has been discovered. The melts produced at 0.2 GPa have compositions similar to those of the bulk continental crust [2,3]. These new findings imply that the Earth's sialic proto-crust may be generated via fluid-assisted melting of serpentinized peridotite at shallow depths (?7 km) that do not require plate subduction during the Hadean eon. Shallow serpentinite dehydration and melting may be the principal physico-chemical processes affecting the earliest lithosphere. Making Earth's continental crust from serpentinite and basalt.
DS201901-0055
2018
Safonov, O.G.Perchuk, A.L., Safonov, O.G., Smit, C.A., van Reenen, D.D., Zakharov, V.S., Gerya, T.V.Precambrian ultra-hot orogenic factory: making and reworking of continental crust.Tectonophysics, Vol. 746, pp. 572-586.Mantlesubduction

Abstract: Mechanisms of Precambrian orogeny and their contribution to the origin of ultrahigh temperature granulites, granite-greenstone terranes and net crustal growth remain debatable. Here, we use 2D numerical models with 150 °C higher mantle temperatures compared to present day conditions to investigate physical and petrological controls of Precambrian orogeny during forced continental plates convergence. Numerical experiments show that convergence between two relatively thin blocks of continental lithosphere with fertile mantle creates a short-lived cold collisional belt that later becomes absorbed by a long-lived thick and flat ultra-hot accretionary orogen with Moho temperatures of 700-1100 °C. The orogen underlain by hot partially molten depleted asthenospheric mantle spreads with plate tectonic rates towards the incoming lithospheric block. The accretionary orogeny is driven by delamination of incoming lithospheric mantle with attached mafic lower crust and invasion of the hot partially molten asthenospheric wedge under the accreted crust. A very fast convective cell forms atop the subducting slab, in which hot asthenospheric mantle rises against the motion of the slab and transports heat towards the moving orogenic front. Juvenile crustal growth during the orogeny is accompanied by net crustal loss due to the lower crust subduction. Stability of an ultra-hot orogeny is critically dependent on the presence of relatively thin and warm continental lithosphere with thin crust and dense fertile mantle roots subjected to plate convergence. Increased thickness of the continental crust and subcontinental lithospheric mantle, pronounced buoyancy of the lithospheric roots, and decreased mantle and continental Moho temperature favor colder and more collision-like orogenic styles with thick crust, reduced magmatic activity, lowered metamorphic temperatures, and decreased degree of crustal modification. Our numerical modeling results thus indicate that different types of orogens (cold, mixed-hot and ultra-hot) could be created at the same time in the Early Earth, depending on compositional and thermal structures of interacting continental blocks.
DS201909-2027
2019
Safonov, O.G.Butvina, V.G., Vorobey, S.S., Safonov, O.G., Varlamov, D.A., Bondarenko, G.V., Shapovalov, Yu.B.Experimental study of the formation of chromium-bearing priderite and yimengite as products of modal mantle metasomatism.Doklady Earth Sciences, Vol. 486, 2, pp. 711-715.Mantlemetasomatism

Abstract: The results of experiments on the synthesis of exotic titanates (priderite and yimengite) simulating metasomatic conditions of alteration of the mantle minerals (chromite and ilmenite) are reported. Ba-free Cr-bearing priderite was synthesized for the first time. Experiments showed the possibility of crystallization of this mineral as a product of the reaction of high-Cr spinel and rutile with hydrous-carbonate fluid (melt) under the conditions of the upper mantle. In particular, the experimental data obtained provide an interpretation of the relationships between K?Cr priderite and carbonate-silicate inclusions in chromites from garnet peridotite of the Bohemian massif. Experimental study of the reaction of chromite and ilmenite with potassic hydrous-carbonate fluid (melt) shows the presence of both titanate phases (priderite and yimengite), the mineral indicators of mantle metasomatism. This provides direct evidence for the formation of yimengite and K?Cr priderite, as well as other titanates, due to mantle metasomatism of the upper mantle peridotite under the conditions of the highest activities of potassium.
DS202011-2050
2020
Safonov, O.G.Limanov, E.V., Butvina, V.G., Safonov, O.G., Van, K.V., Aranovich, L. Ya.Phlogopite formation in the orthopyroxene-garnet system in the presence of H2O-KCL fluid to the processes of mantle metasomatism.Doklady Earth Sciences, Vol. 494, 1, pp. 713-717.Russiametasomatism

Abstract: The results of experimental studies are presented for reactions in the orthopyroxene-garnet-phlogopite system in the presence of H2O-KCl fluid at 3-5 GPa and 900-1000°C, which model the processes of phlogopite formation in garnet peridotites and pyroxenites during alkaline metasomatism of the upper mantle. The experiments demonstrated regular variations in the composition of garnet, pyroxenes, and phlogopite depending on the KCl content of the fluid. With increasing KCl content of the fluid, enstatite and garnet become unstable, the Al2O3 content of enstatite decreases, and the amount of grossular and knorringite components in garnet are maximum at a KCl content of ~10 mol %. Our results illustrate well the regular variations in the compositions of the coexisting minerals and their zoning in phlogopite-bearing peridotites of the lithospheric mantle.
DS202012-2206
2020
Safonov, O.G.Borisova, A.Y., Bindeman, I.N., Toplis, M.J., Zagrtdenov, N.R., Guignard, J., Safonov, O.G., Bychkov, A.Y., Shcheka, S., Melnik, O.E., Marcelli, M., Fehrenbach, J.Zircon survival in shallow asthenosphere and deep lithosphere.American Mineralogist, Vol. 105, pp. 1662-1671. pdfMantlemelting

Abstract: Zircon is the most frequently used mineral for dating terrestrial and extraterrestrial rocks. However, the system of zircon in mafic/ultramafic melts has been rarely explored experimentally and most existing models based on the felsic, intermediate and/or synthetic systems are probably not applicable for prediction of zircon survival in terrestrial shallow asthenosphere. In order to determine the zircon stability in such natural systems, we have performed high-temperature experiments of zircon dissolution in natural mid-ocean ridge basaltic and synthetic haplobasaltic melts coupled with in situ electron probe microanalyses of the experimental products at high current. Taking into account the secondary fluorescence effect in zircon glass pairs during electron microprobe analysis, we have calculated zirconium diffusion coefficient necessary to predict zircon survival in asthenospheric melts of tholeiitic basalt composition. The data imply that typical 100 micron zircons dissolve rapidly (in 10 hours) and congruently upon the reaction with basaltic melt at mantle pressures. We observed incongruent (to crystal ZrO2 and SiO2 in melt) dissolution of zircon in natural mid-ocean ridge basaltic melt at low pressures and in haplobasaltic melt at elevated pressure. Our experimental data raise questions about the origin of zircons in mafic and ultramafic rocks, in particular, in shallow oceanic asthenosphere and deep lithosphere, as well as the meaning of the zircon-based ages estimated from the composition of these minerals. Large size zircon megacrysts in kimberlites, peridotites, alkali basalts and other magmas suggest the fast transport and short interaction between zircon and melt.The origin of zircon megacrysts is likely related to metasomatic addition of Zr into mantle as any mantle melting episode should obliterate them.
DS202106-0964
2021
Safonov, O.G.Perchuk, A.L., Sapegina, A.V., Safonov, O.G., Yapaskurt, V.O., Shatsky, V.S., Malkovets, V.G.Reduced amphibolite facies conditions in the Precambrian continental crust of the Siberian craton recorded by mafic granulite xenoliths from the Udachnaya kimberlite pipe, Yakutia.Precambrian Research, Vol. 357, 1061022, 14p. PdfRussia, Yakutiadeposit - Udachnaya

Abstract: It is widely accepted that granulite xenoliths from kimberlites provide a record of granulite facies metamorphism at the basement of cratons worldwide. However, application of the phase equilibria modeling for seven representative samples of mafic granulites from xenoliths of the Udachnaya kimberlite pipe, Yakutia, revealed that a granulitic garnet + clinopyroxene + plagioclase ± orthopyroxene ± amphibole ± scapolite mineral assemblage was likely formed in the middle crust under amphibolite facies conditions (600-650 °C and 0.8-1.0 GPa) in a deficiency of fluid. Clinopyroxene in the rocks is characterized by elevated aegirine content (up to 10 mol.%) both in the earlier magmatic cores and in the later metamorphic rim zones of the grains. Nevertheless, the phase equilibrium modeling for all samples indicates surprisingly reduced conditions, i.e. oxygen fugacity 1.6-3.3 log units below the FMQ (Fayalite-Magnetite-Quartz) buffer. In contrast, the coexistence of Fe-Ti oxides indicates temperatures of 850-990 °C and oxygen fugacity about lg(FMQ) ± 0.5, conditions which correspond to earlier stages of rock evolution. Reduction of oxygen fugacity during cooling is discussed in the context of the evolution of a complex fluid. The reconstructed P-T conditions for the final equilibration in the mafic granulites indicate that temperatures were ~250 °C higher than those extrapolated from the continental conductive geotherm of 35-40 µW/m2 deduced from peridotite xenoliths of the Udachnaya pipe. Although the granulites resided in the crust for a period for at least 1.4 Ga, they did not re-equilibrate to the temperatures of the geotherm, likely due to the blocking of mineral reactions under relatively low temperatures and fluid-deficient conditions
DS200512-0031
2002
SafonovaAshchepkov, I.V., Saprykin, A.I., Gerasim, Khmeintkova, Cheremenykk, Safonova, Rasskazov, Kinolin, VladykinPetrochemistry of mantle xenoliths from Sovgavan Plateau, Far East Russia.Deep Seated Magmatism, magmatism sources and the problem of plumes., pp. 213-222.RussiaXenoliths
DS201412-0767
2014
Safonova, I.Safonova, I., Maruyama, S., Litasov, K.Generation of hydrous plumes in the mantle transition zone linked to the tectonic erosion of continental crust.V.S. Sobolev Institute of Geology and Mineralogy Siberian Branch Russian Academy of Sciences International Symposium Advances in high pressure research: breaking scales and horizons ( Courtesy of N. Poikilenko), Held Sept. 22-26, 3p. AbstractMantleSubduction
DS201702-0222
2017
Safonova, I.Y.Kolesnichenko, M.V., Zedgenizov, D.A., Litasov, K.D., Safonova, I.Y., Ragozin, A.L.Heterogenesous distribution of water in the mantle beneath the central Siberian Craton: implications for Udachnaya kimberlite pipe.Gondwana Research, in press available 18p.RussiaDeposit - Udachnaya

Abstract: The paper presents new petrographic, major element and Fourier transform infrared (FTIR) spectroscopy data and PT-estimates of whole-rock samples and minerals of a collection of 19 relatively fresh peridotite xenoliths from the Udachnaya kimberlite pipe, which were recovered from its deeper levels. The xenoliths are non-deformed (granular), medium-deformed and highly deformed (porphyroclastic, mosaic-porphyroclastic, mylonitic) lherzolites, harzburgite and dunite. The lherzolites yielded equilibration temperatures (T) and pressures (P) ranging from 913 to 1324 °C and from 4.6 to 6.3 GPa, respectively. The non-deformed and medium-deformed peridotites match the 35 mW/m2 conductive continental geotherm, whereas the highly deformed varieties match the 45 mW/m2 geotherm. The content of water spans 2 ± 1-95 ± 52 ppm in olivine, 1 ± 0.5-61 ± 9 ppm in orthopyroxene, and 7 ± 2-71 ± 30 ppm in clinopyroxene. The amount of water in garnets is negligible. Based on the modal proportions of mineral phases in the xenoliths, the water contents in peridotites were estimated to vary over a wide range from < 1 to 64 ppm. The amount of water in the mantle xenoliths is well correlated with the deformation degree: highly deformed peridotites show highest water contents (64 ppm) and those medium-deformed and non-deformed contain ca. 1 ppm of H2O. The high water contents in the deformed peridotites could be linked to metasomatism of relatively dry diamondiferous cratonic roots by hydrous and carbonatitic agents (fluids/melts), which may cause hydration and carbonation of peridotite and oxidation and dissolution of diamonds. The heterogeneous distribution of water in the cratonic mantle beneath the Udachnaya pipe is consistent with the models of mantle plume or veined mantle structures proposed based on a trace element study of similar xenolithic suits. Mantle metasomatism beneath the Siberian Craton and its triggered kimberlite magmatism could be induced by mantle enrichment in volatiles (H2O, CO2) supplied by numerous subduction zones which surrounded the Siberian continent in Neoproterozoic-Cambrian time.
DS201706-1086
2017
Safonova, I.Y.Kolesnichenko, M.V., Zedgenizov, D.A., Litasov, K.D., Safonova, I.Y., Ragozin, A.L.Heterogeneous distribution of water in the mantle beneath the central Siberian craton: implications from the Udachachnaya kimberlite pipe.Gondwana Research, Vol. 47, pp. 249-266.Russiadeposit - Udachnaya

Abstract: The paper presents new petrographic, major element and Fourier transform infrared (FTIR) spectroscopy data and PT-estimates of whole-rock samples and minerals of a collection of 19 relatively fresh peridotite xenoliths from the Udachnaya kimberlite pipe, which were recovered from its deeper levels. The xenoliths are non-deformed (granular), medium-deformed and highly deformed (porphyroclastic, mosaic-porphyroclastic, mylonitic) lherzolites, harzburgite and dunite. The lherzolites yielded equilibration temperatures (T) and pressures (P) ranging from 913 to 1324 °C and from 4.6 to 6.3 GPa, respectively. The non-deformed and medium-deformed peridotites match the 35 mW/m2 conductive continental geotherm, whereas the highly deformed varieties match the 45 mW/m2 geotherm. The content of water spans 2 ± 1-95 ± 52 ppm in olivine, 1 ± 0.5-61 ± 9 ppm in orthopyroxene, and 7 ± 2-71 ± 30 ppm in clinopyroxene. The amount of water in garnets is negligible. Based on the modal proportions of mineral phases in the xenoliths, the water contents in peridotites were estimated to vary over a wide range from < 1 to 64 ppm. The amount of water in the mantle xenoliths is well correlated with the deformation degree: highly deformed peridotites show highest water contents (64 ppm) and those medium-deformed and non-deformed contain ca. 1 ppm of H2O. The high water contents in the deformed peridotites could be linked to metasomatism of relatively dry diamondiferous cratonic roots by hydrous and carbonatitic agents (fluids/melts), which may cause hydration and carbonation of peridotite and oxidation and dissolution of diamonds. The heterogeneous distribution of water in the cratonic mantle beneath the Udachnaya pipe is consistent with the models of mantle plume or veined mantle structures proposed based on a trace element study of similar xenolithic suits. Mantle metasomatism beneath the Siberian Craton and its triggered kimberlite magmatism could be induced by mantle enrichment in volatiles (H2O, CO2) supplied by numerous subduction zones which surrounded the Siberian continent in Neoproterozoic-Cambrian time.
DS200612-1200
2006
Safonova, I.Yu.Safonova, I.Yu.Geochemistry of within plate basaltic lavas from the SW Palo-Asian ocean: evolution of plume magmatism from the Late Vendian to the Early Cambrian.Vladykin: VI International Workshop, held Mirny, Deep seated magmatism, its sources and plumes, pp. 159-173.AsiaMagmatism
DS200612-1201
2005
Safonova, I.Yu.Safonova, I.Yu., Buslov, M.M.Geochemical diversity in oceanic basalts of the Zasurin Formation NE Altai Russia: trace element evidence for mantle plume magmatism.Problems of Sources of deep magmatism and plumes., pp. 247-266.Russia, AltaiMagmatism
DS1975-0179
1975
Safranovskii, I.I.Safranovskii, I.I., Schmidt, W.Relationships between the crystallography of diamonds and their SOURCE[ In: Industrieminerale. Vortaege des berg und hutten maennischem tages @Freiberger Forschungshefts, ReiheIn: Industrieminerale. Vortaege des berg und huttenmaennischem tages, Mineralogie-geochemie, Vol. 296, pp.19-30. *GerRussiaDiamond Morphology
DS1994-1514
1994
Safrinov, A.F.Safrinov, A.F., Suvonov, V.D., Zaitsev, A.I., Nenashev, N.I.The kimberlite controlling zones in the uppermost mantle of west YakutiaProceedings of Fifth International Kimberlite Conference, Vol. 1, pp. 172-176.Russia, YakutiaStructure, Kimberlite
DS1981-0313
1981
Safronov, A.F.Nikishov, K.N., Safronov, A.F.Some Problems of the Genesis of Chromites and Magnesian Garnets of Inclusions in Diamonds and Kimberlitic Rocks.Doklady Academy of Sciences Nauk SSSR., Vol. 256, No. 5, PP. 1215-1217.RussiaMineralogy
DS1982-0462
1982
Safronov, A.F.Nikishov, K.N., Safronov, A.F.Some Aspects of the Genesis of Chromite and Magnesium Garnet from Inclusions in Diamonds and from Kimberlitic Rocks.Doklady Academy of Science USSR, Earth Science Section., Vol. 256, No. 5, PP. 139-140.RussiaInclusions, Mineralogy, Petrography
DS1982-0534
1982
Safronov, A.F.Safronov, A.F., Nikishov, K.N.Fluid Regime of the Upper Mantle and the Mineral Associations in Diamonds.Doklady Academy of Sciences Nauk SSSR., Vol. 262, No. 4, PP. 961-963.RussiaKimberlite
DS1983-0353
1983
Safronov, A.F.Kharkiv, A.D., Nikishov, K.N., Safronov, A.F., Savrasov, D.I.Genesis of Amphibolized Plutonic Xenoliths from the Obnazhennaya Kimberlite PipeDoklady Academy of Science USSR, Earth Science Section., Vol. 262, No. 1-6, PP. 142-146.RussiaMineral Chemistry, Analyses, Garnet Lherzolite
DS1983-0551
1983
Safronov, A.F.Safronov, A.F., Egorov, K.N., Makhotko, V.F.Pecularities of the Temperature Regime of Kimberlite Melt CrystallizationDoklady Academy of Sciences AKAD. NAUK SSSR., Vol. 269, No. 2, PP. 454-457.RussiaGenesis
DS1983-0552
1983
Safronov, A.F.Safronov, A.F., Nikishov, K.N.Fluid Regime of the Upper Mantle and Mineral Associations In Diamonds.Doklady Academy of Science USSR, Earth Science Section., Vol. 262, No. 1-6. PP. 174-177.Russia, South AfricaKimberlite, Diamond Genesis
DS1984-0625
1984
Safronov, A.F.Safronov, A.F., Yegorov, K.N., Makhotko, V.F.Thermal Regime of Crystallization of Kimberlite MeltDoklady Academy of Science USSR, Earth Science Section., Vol. 269, No. 1-6, SEPT. PP. 119-121.RussiaUdachnaya, Crystallography, Mineralogy
DS1985-0337
1985
Safronov, A.F.Kharkiv, A.D., Nikishov, K.N., Safronov, A.F., Savrasov, D.I.Plutonic Metasomatism of Zoned Mantle Xenoliths from the Obnazhennaya Kimberlite Pipe.Doklady Academy of Science USSR, Earth Science Section., Vol. 271, No. 1-6, PP. 153-156.RussiaXenoliths, Mineralogy
DS1985-0338
1985
Safronov, A.F.Kharkiv, A.D., Nikishov, K.N., Safronov, A.F., Savrasov, D.I.Plutonic metasomatism of zoned mantle xenoliths from the Obnazhennaya kimberlite pipeDoklady Academy of Science USSR, Earth Science Section, Vol. 271, No. 1-6, January pp. 153-156RussiaBlank
DS1985-0362
1985
Safronov, A.F.Kovalski, V.V., Safronov, A.F., Nikisov, K.N.Vertical Mineralogical Zoning of Kimberlite Magmatism.(russian)Doklady Academy of Sciences Akademy Nauk SSSR.(Russian), Vol. 285, No. 6, pp, 1439-1442RussiaBlank
DS1985-0496
1985
Safronov, A.F.Nikishov, K.N., Kovalskiy, V.V., Safronov, A.F.Petrological and geochemical features of deep seated Evolution of matterfor kimberlite and basic magmatic systems.(Russian)Yakut. Fil. Sibirskoe Otd. AN. SSSR., (Russian), 200pRussiaGeochemistry
DS1985-0579
1985
Safronov, A.F.Safronov, A.F., Nikolayev, N.S.Statistical comparison of garnets from kimberlite rocks and from plutonicxenoliths. (Russian)In: Petrologic and Geochemical Features of the Plutonic Evolution of, pp. 38-50RussiaBlank
DS1986-0211
1986
Safronov, A.F.Egorov, K.N., Kornilova, V.P., Safronov, A.F., Fillippov, N.D.Micaceous kimberlite from the Udachnia Vostochnaia pipe.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR (Russian), Vol. 291, No. 1, pp. 199-201RussiaMineralogy, Mica
DS1986-0780
1986
Safronov, A.F.Spetsius, Z., Safronov, A.F.Some compositional; characteristics of rutile in eclogitic associations and those in paragenesis with diamond.(Russian)Zap. Vses. Mineral O-Va, (Russian), Vol. 115, No. 6, pp. 699-705RussiaParagenesis
DS1987-0344
1987
Safronov, A.F.Kharkiv, A.D., Matsyuk, S.S., Safronov, A.F., Makhoto, V.F.Minerals in xenoliths of deep seated rocks from kimberlites oftheInternationial'Naya' pipe, Yakutia.(Russian)Mineral. Zhurn., *UKR., Vol. 9, No. 4, pp. 62-71RussiaBlank
DS1987-0345
1987
Safronov, A.F.Kharkiv, A.D., Safronov, A.F., Makhotko, V.F.Deep seated xenoliths from the Aikhal kimberlite pipe.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR (Russian), Vol. 295, No. 2, pp. 482-486RussiaGeothermometry, Xenoliths
DS1987-0372
1987
Safronov, A.F.Kovalskiy, V.V., Safronov, A.F., Nikishov, K.N.Vertical mineralogic zoning of kimberlite volcanismDoklady Academy of Science USSR, Earth Science Section, Vol. 285, No. 6, pp. 158-160RussiaBlank
DS1988-0351
1988
Safronov, A.F.Kharkiv, A.D., Matsyuk, S.S., Safronov, A.F.Mineralogy of deep seated xenolithic rocks From kimberlites of the Aikhal pipe (western Yakutia) USSR. (Russian)Mineral Zhurn.(Russian), Vol. 42, No. 1, pp. 20-30RussiaKimberlite, Mineralogy
DS1988-0352
1988
Safronov, A.F.Kharkiv, A.D., Matsyuk, S.S., Safronov, A.F.Mineralogy of deep seated xenoliths from the Aykalkimberlite pipe, Western Yakutia.(Russian)Mineral. Sbornik (L'Vov), (Russian), Vol. 42, No. 1, pp. 20-30RussiaPetrology, Deposit -Aykal
DS1988-0353
1988
Safronov, A.F.Kharkiv, A.D., Safronov, A.F., Makhotko, V.F.Plutonic xenoliths from the Aykhal kimberlite pipeDoklady Academy of Science USSR, Earth Science Section, Vol. 295, No. 1-6, Nov. pp. 165-168RussiaAnalyses -garnet, ratios with Cr2O3
DS1988-0519
1988
Safronov, A.F.Oleinikov, O.B., Safronov, A.F.Unusual association of chrome bearing kyanite, spinel, garnet and rutile from microxenolith of the kimberlite breccia of the Ruslovaia pipe.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 299, No. 4, pp. 964-969RussiaBlank
DS1989-0768
1989
Safronov, A.F.Kharkiv, A.D., Kvasnitsa, V.N., Safronov, A.F., Zinchuk, N.N.Typomorphism of diamond and associated minerals from kimberlites.(Russian)Naukova Dumka Kiev Publishing (Russian), 181pRussiaKimberlite mineralogy, TypomorphisM.
DS1990-1291
1990
Safronov, A.F.Safronov, A.F., Suvorov, V.D., Zaitsev, A.I.Indications of kimberlite magmatism in the crust and the upper mantle ofYakutia.(Russian)Doklady Academy of Sciences Nauk USSR*(in Russian), Vol. 312, No. 5, pp. 1204-1206RussiaMantle, Kimberlite magma
DS1991-1485
1991
Safronov, A.F.Safronov, A.F., Suvorov, V.D., Zairsev, A.I., Nenashev, N.I.Kimberlite controlling zones in the crust and uppermost mantle of the westYakutia: their composition and evolutionProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 541-542RussiaGeophysics -seismics, Kimberlite controlling zone KCZ
DS1992-0858
1992
Safronov, A.F.Kharkiv, A.D., Levin, V.I., Mankenda, A., Safronov, A.F.The Camafuca-Camazambo kimberlite pipe of Angola, the largest in theworldInternational Geology Review, Vol. 34, No. 7, July pp. 710-719AngolaKimberlite, Deposit -Camafuca-Camazambo
DS1995-0946
1995
Safronov, A.F.Kharkiv, A.D., Safronov, A.F.Composition In homogeneity of kimberlitic garnet nodules as indicator of their metasomatism and disintegrationProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 273-274.Russia, YakutiaMetasomatism, Deposit -Mir, International, Congress, Dachnaya
DS1995-1004
1995
Safronov, A.F.Kornilova, V.P., Safronov, A.F.Kimberlites of Yakutia and South Africa. Aspects of comparative studyProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 295-297.Russia, Yakutia, South AfricaKimberlite, Petrology
DS1995-1646
1995
Safronov, A.F.Safronov, A.F.Zoning of kimberlite provinces and evolution of kimberlite magmatismProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 490-491.South Africa, Russia, YakutiaMagmatism -zones, Alluvials, placers
DS1995-2113
1995
Safronov, A.F.Zairsev, A.I., Safronov, A.F.Main epochs of upper mantle activization in the Siberian PlatformProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 675-677.Russia, SiberiaGeochronology, Deposit -Mir, Udachnaya, Komosomolskaya, Jubilee
DS1995-2115
1995
Safronov, A.F.Zaitsev, A.I., Safronov, A.F., Brakfogel, F.F.Rubidium strontium isotope geochemistry of kimberlites and deep seated xenoliths of the Kharamai field.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 678-679.Russia, Siberia, AnabarGeochemistry, Deposit -Kharamai region
DS1996-0776
1996
Safronov, A.F.Kornilova, V.P., Safronov, A.F.Evolution of kimberlite magmatismInternational Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 387.RussiaMagmatism, Kimberlites
DS1996-1053
1996
Safronov, A.F.Oleinikov, O.B., Safronov, A.F., Kornilova, V.P., ZaitsevA first find of melanephelinite xenolith in kimberlite rocksRussian Geology and Geophysics, Vol. 37, No. 6, pp. 54-58.Russia, YakutiaXenolith, Deposit - Obnazhennaya
DS1998-0778
1998
Safronov, A.F.Komilova, V.P., Safronov, A.F., Phillipov, N. Zauzev.The garnet of diamond association in lamprophyres from the Anabar massif7th International Kimberlite Conference Abstract, pp. 458-9.Russia, Yakutia, AnabarDiamond inclusions, Lamprophyres
DS1992-1319
1992
Safronov, A.F.Jr.Safronov, A.F.Jr.Geodynamic significance of the kimberlite magmatismProceedings of the 29th International Geological Congress. Held Japan August 1992, Vol. 2, abstract p. 576RussiaStructure, Continental zones
DS200512-0926
2004
Safronov, I.Yu.Safronov, I.Yu., Buslov, M.M.Geochemistry of oceanic basalts of the Katun accretionary wedge in northern Gorny Altai: evidence for mantle plume magmatism.Deep seated magmatism, its sources and their relation to plume processes., pp. 273-298.Russia, MantleMagmatism
DS1987-0750
1987
Safronov, P.P.Tugovik, G.I., Safronov, P.P., Kirasirova, V.I.Crystal morphology of diamonds from rutile-sphene eclogite #1Doklady Academy of Science USSR, Earth Science Section, Vol. 297, No. 6, Nov-Dec pp. 131-134RussiaDiamond morphology, Eclogite
DS1987-0751
1987
Safronov, P.P.Tugovik, G.I., Safronov, P.P., Kirasirova, V.I.Pecularities of the crystal morphology of diamonds from rutilespheneeclogites. (Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 297, No 1, pp.187-191RussiaBlank
DS1987-0752
1987
Safronov, P.P.Tugovik, G.I., Safronov, P.P., Kirasirova, V.I.Characteristics of the crystal morphology of diamonds fromrutile-spheneeclogites.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 297, No. 1, pp. 187-191RussiaBlank
DS1989-1519
1989
Safronov, P.P.Tugovik, G.I., Safronov, P.P., Kirasirova, V.I.Crystal morphology of diamonds from rutile-sphene eclogite #2Doklady Academy of Science USSR, Earth Science Section, Vol. 297, No. 1-6, pp. 131-134RussiaDiamond morphology, Eclogite
DS1982-0464
1982
Safronova, F.Nikishova, L.V., Nikishov, K.N., Kornilova, V.P., Safronova, F.Electron Microscopy of Serpentinite Xenoliths in KimberlitesIzvest. Akad. Nauk Sssr Ser. Geol., No. 4, PP. 60-69.RussiaBlank
DS1993-1362
1993
Safyannikov, V.Y.Safyannikov, V.Y., Minorin, V.E.Some aspects of delineation of primary diamond depositsDiamonds of Yakutia, Russia, Extended Abstracts, Volume in English $ 115.00, pp. 93-96.Russia, YakutiaPrimary deposits, Evaluation
DS1993-1363
1993
Safyannikov, V.Y.Safyannikov, V.Y., Minorin, V.E.Prospecting evaluation of diamond depositsDiamonds of Yakutia, Russia, Extended Abstracts, Volume in English $ 115.00, pp. 89-92.Russia, YakutiaProspecting, Evaluation
DS201806-1245
2018
Saga, S.Saga, S., Dasguota, R., Tsuno, K.High pressure phase relations of a depleted peridotite fluxed by CO2, H2O bearing siliceous melts and the origin of mid lithospheric discontinuity.Geochemistry, Geophysics, Geosystems, Vol. 19, 3, pp. 595-620.Mantleperidotites

Abstract: We present phase equilibria experiments on a depleted peridotite (Mg# 92) fluxed with variable proportions of a slab?derived rhyolitic melt (with 9.4 wt.% H2O, 5 wt.% CO2), envisaging an interaction that could occur during formation of continents by imbrication of slabs/accretion of subarc mantles. Experiments were performed with 5 wt.% (Bulk 2) and 10 wt.% (Bulk 1) melt at 950-1175°C and 2-4 GPa using a piston?cylinder and a multi?anvil apparatus, to test the hypothesis that volatile?bearing mineral?phases produced during craton formation can cause reduction in aggregate shear?wave velocities (VS) at mid?lithospheric depths beneath continents. In addition to the presence of olivine, orthopyroxene, clinopyroxene, and garnet/spinel, phlogopite (Bulk 1: 3-7.6 wt.%; Bulk 2: 2.6-5 wt.%) at 2-4 GPa, and amphibole (Bulk 1: 3-9 wt.%; Bulk 2: 2-6 wt.%) at 2-3 GPa (?1050°C) are also present. Magnesite (Bulk 1: ?1 wt.% and Bulk 2: ?0.6 wt.%) is present at 2-4 GPa (<1000°C at 3 and?100 km depth.
DS202007-1175
2020
Sagatov, N.Sagatova, D., Shatskiy, A., Sagatov, N., Gavryushkin, P.N., Litasov, K.D.Calcium orthocarbonate, Ca2CO4-Pnma: a potential host for subducting carbon in the transition zone and lower mantle.Lithos, in press available, 22p. PdfMantlesubduction

Abstract: A novel structure of calcium orthocarbonate Ca2CO4-Pnma has been discovered using ab-initio crystal structure prediction methods (AIRSS and USPEX) based on the density functional theory. This phase appears above 13 GPa and remains stable to at least 50 GPa and 2000 K according to the calculations within quasi-harmonic approximation. Thus, the discovered phase can be stable at Earth's transition zone and lower mantle P-T conditions. The carbon atoms in the discovered phase are presented in 4-fold coordination, and its structure is similar to the high-pressure and high-temperature ?'H-Ca2SiO4 phase.
DS202008-1439
2020
Sagatov, N.Sagatova, D., Shatskiy, A., Sagatov, N., Gavryushkin, P.N., Litasov, K.D.Calcium orthocarbonate, CaCO4-Pnma: a potential host for subducting carbon in the transition zone and lower mantle.Lithos, Vol. 370-371, 105637 5p. PdfMantlesubduction

Abstract: A novel structure of calcium orthocarbonate Ca2CO4-Pnma has been discovered using ab-initio crystal structure prediction methods (AIRSS and USPEX) based on the density functional theory. This phase appears above 13 GPa and remains stable to at least 50 GPa and 2000 K according to the calculations within quasi-harmonic approximation. Thus, the discovered phase can be stable at Earth's transition zone and lower mantle P-T conditions. The carbon atoms in the discovered phase are presented in 4-fold coordination, and its structure is similar to the high-pressure and high-temperature ?'H-Ca2SiO4 phase.
DS202007-1175
2020
Sagatova, D.Sagatova, D., Shatskiy, A., Sagatov, N., Gavryushkin, P.N., Litasov, K.D.Calcium orthocarbonate, Ca2CO4-Pnma: a potential host for subducting carbon in the transition zone and lower mantle.Lithos, in press available, 22p. PdfMantlesubduction

Abstract: A novel structure of calcium orthocarbonate Ca2CO4-Pnma has been discovered using ab-initio crystal structure prediction methods (AIRSS and USPEX) based on the density functional theory. This phase appears above 13 GPa and remains stable to at least 50 GPa and 2000 K according to the calculations within quasi-harmonic approximation. Thus, the discovered phase can be stable at Earth's transition zone and lower mantle P-T conditions. The carbon atoms in the discovered phase are presented in 4-fold coordination, and its structure is similar to the high-pressure and high-temperature ?'H-Ca2SiO4 phase.
DS202008-1439
2020
Sagatova, D.Sagatova, D., Shatskiy, A., Sagatov, N., Gavryushkin, P.N., Litasov, K.D.Calcium orthocarbonate, CaCO4-Pnma: a potential host for subducting carbon in the transition zone and lower mantle.Lithos, Vol. 370-371, 105637 5p. PdfMantlesubduction

Abstract: A novel structure of calcium orthocarbonate Ca2CO4-Pnma has been discovered using ab-initio crystal structure prediction methods (AIRSS and USPEX) based on the density functional theory. This phase appears above 13 GPa and remains stable to at least 50 GPa and 2000 K according to the calculations within quasi-harmonic approximation. Thus, the discovered phase can be stable at Earth's transition zone and lower mantle P-T conditions. The carbon atoms in the discovered phase are presented in 4-fold coordination, and its structure is similar to the high-pressure and high-temperature ?'H-Ca2SiO4 phase.
DS201112-0440
2011
Sagawe, A.Hofmann, M., Linnemann, U., Rai, V., Becker, S., Gartner, A., Sagawe, A.The India and South Chin a cratons at the margin of Rodinia - synchronous Neoproterozoic magmatism revealed by LA-ICP-MS zircon analyses.Lithos, In press available 65p.India, ChinaMagmatism
DS201911-2561
2019
Sagdic, N.G.Sengor, A.M.C., Lom, N., Sagdic, N.G.Tectonic inheritance in the lithosphere.IN: Cycle Concepts in Plate Tectonics, editors Wilson and Houseman , Geological Society of London special publication 470, pp. 105-136.Mantleplate tectonics
DS1987-0045
1987
SageBell, K., Blenkinsop, J., Kwon, Tlton, SageAge and radiogenic isotopic systematics of the Border carbonatite complexOntario, canada.Canadian Journal of Earth Sciences, Vol. 24, pp. 24-30.OntarioGeochronology, deposit - Borden
DS1993-1364
1993
Sage, R.Sage, R., Morris, T., Sears, S.MNDM ( Ontario Geological Survey) announces the possibility of Diamond bearing kimberlite in the Wawa area.Ontario Geological Survey News release, No. 182, December 14, 2p.OntarioNews item, Dead River, indicator minerals
DS1994-1244
1994
Sage, R.Morris, T.F., Sage, R., Crabtree, D.Diamonds in the Wawa areaPreprint handout Ontario Geological Survey (OGS) Seminar Dec., 19p.OntarioHistory and diamond finds, Michipicoten -Wawa
DS2000-0850
2000
Sage, R.Sage, R.Distribution of kimberlite intrusions and diamond bearing lamprophyres in Ontario.Toronto Geological Discussion Group, absts Oct. 24, pp. 4-8.OntarioOverview, Kimberlites, lamprophyres
DS200612-1202
2005
Sage, R.Sage, R., Crabtree, D., Morriss, T.Skeletal and orbicular textures in Mesoproterozoic carbonatite complexes of the Superior Province, Ontario.Ontario Geological Survery Preprint from author, 17p. plus figs.tablesCanada, OntarioCarbonatite
DS1975-0859
1978
Sage, R.P.Sage, R.P.Diatremes and Shock Features in Precambrian Rocks of the Slate Islands, Northeastern Lake Superior.Geological Society of America (GSA) Bulletin., Vol. 89, PP. 1529-1540.Canada, OntarioDiatreme
DS1980-0297
1980
Sage, R.P.Sage, R.P.Diatremes and Shock Features in Precambrian Rocks of the Slate Islands, Northeastern Lake Superior: Reply.Geological Society of America (GSA) Bulletin., Vol. 91, No. 1, PP. 313-314.Canada, OntarioBlank
DS1985-0580
1985
Sage, R.P.Sage, R.P.Geology of Carbonatite Alkalic Rock Complexes in Ontario, Chipman Lake Area, Districts of Thunder Bay and Cochrane.Ontario Geological Survey STUDY, No. 44, 44P.Canada, OntarioCarbonatite
DS1986-0697
1986
Sage, R.P.Sage, R.P., Watkinson, D.H.Alkalic rock-carbonatite complexes of the Precambrian shield of OntarioGeological Association of Canada (GAC) Annual Meeting, Vol. 11, p. 122. (abstract.)OntarioCarbonatite, Alkaline rocks
DS1987-0637
1987
Sage, R.P.Sage, R.P.Geology of the carbonatite-alkalic rock complexes in Ontario:Nemegosenda Lake alkalic rock complex, district of SudburyOntario Geological Survey Study, No. 34, 132p. 1 chartOntarioCarbonatite
DS1987-0638
1987
Sage, R.P.Sage, R.P.James Bay LowlandsOntario Geological Survey Study, No. 42, 49pOntarioCarbonatite, Geophysics
DS1987-0639
1987
Sage, R.P.Sage, R.P.Carb Lake carbonatite complexOntario Geological Survey Study, No. 53, 42pOntarioCarbonatite, Geophysics
DS1987-0640
1987
Sage, R.P.Sage, R.P.Geology of carbonatite-alkalic rock complexes in Ontario:Big Beaver House carbonatite complexOntario Geological Survey Study, No. 51, 62pOntarioIjolite, carbonatite, petrography
DS1987-0641
1987
Sage, R.P.Sage, R.P.Spanish River carbonatite complexOntario Geological Survey Study, No. 30, 62pOntarioIjolite, Sovite
DS1988-0591
1988
Sage, R.P.Sage, R.P.Geology of carbonatite-alkalic rock complexes inOntario: Argorcarbonatite complex, District ofCochraneOntario Geological Survey Study, No. 41, 90pOntarioCarbonatite, Argor
DS1988-0592
1988
Sage, R.P.Sage, R.P.Geology of carbonatite-alkalic rock complexes inOntario:Nagagami River Alkalic rock complex, District of CochraneOntario Geological Survey Study, No. 36, 92pOntarioCarbonatite, Cargill
DS1988-0593
1988
Sage, R.P.Sage, R.P.Geology of carbonatite-alkalic rock complexes inOntario: Valentine Township carbonatite complex,District of CochraneOntario Geological Survey Study, No. 37, 104pOntarioCarbonatite, Clay-Howells
DS1988-0594
1988
Sage, R.P.Sage, R.P.Geology of carbonatite-alkalic rock complexes inOntario: Clay- Howells alkalic rock complex, District of CochraneOntario Geological Survey Study, No. 47, 83pOntarioCarbonatite, Firesand River
DS1988-0595
1988
Sage, R.P.Sage, R.P.Geology of carbonatite-alkalic rock complexes inOntario: Fire sand River carbonatite complex, District of AlgomaOntario Geological Survey Study, No. 40, 45pOntarioCarbonatite, Goldray
DS1988-0596
1988
Sage, R.P.Sage, R.P.Geology of carbonatite-alkalic rock complexes inOntario: Goldray carbonatite complex, District ofCochraneOntario Geological Survey Study, No. 38, 38pOntarioCarbonatite, Hecla-Kilmer
DS1988-0597
1988
Sage, R.P.Sage, R.P.Geology of carbonatite-alkalic rock complexes inOntario: Hecla-Kilmeralkalic rock complex, District of CochraneOntario Geological Survey Study, No. 45, 120pOntarioCarbonatite, Killala Lake
DS1988-0598
1988
Sage, R.P.Sage, R.P.Geology of carbonatite-alkalic rock complexes inOntario: Killala Lake Alkalic rock complex, District of Thunder BayOntario Geological Survey Study, No. 43, 48pOntarioCarbonatite, Nagagami River
DS1988-0599
1988
Sage, R.P.Sage, R.P.Geology of carbonatite-alkalic rock complexes inOntario: Wapikopa Lake Alkalic complex, District ofKenoraOntario Geological Survey Study, No. 48, 68pOntarioCarbonatite, Poohbah Lake
DS1988-0600
1988
Sage, R.P.Sage, R.P.Geology of carbonatite-alkalic rock complexes inOntario: Poohbah Lake Alkalic rock complex, District of Rainy RiverOntario Geological Survey Study, No. 50, 43pOntarioCarbonatite, Schruburt Lake
DS1988-0601
1988
Sage, R.P.Sage, R.P.Geology of carbonatite-alkalic rock complexes inOntario: Schruburt Lake carbonatite complex,District of KenoraOntario Geological Survey Study, No. 31, 45pOntarioCarbonatite, Seabrook Lake
DS1988-0602
1988
Sage, R.P.Sage, R.P.Geology of carbonatite-alkalic rock complexes inOntario:Cargill Township carbonatite complex. District of CochraneOntario Geological Survey Study, No. 49, 116pOntarioCarbonatite, Sturgeon Narrows, Squaw La
DS1988-0603
1988
Sage, R.P.Sage, R.P.Geology of carbonatite-alkalic rock complexes inOntario: Seabrook Lake carbonatite complex, district of AlgomaOntario Geological Survey Study, No. 39, 37pOntarioCarbonatite, Valentine
DS1988-0604
1988
Sage, R.P.Sage, R.P.Geology of carbonatite-alkalic rock complexes inOntario: Sturgeon Narrow sand Squaw Lake Alkalic rockcomplexes, District of Thunder BayOntario Geological Survey Study, No. 52, 62pOntarioCarbonatite, Wapikopa Lake
DS1991-1486
1991
Sage, R.P.Sage, R.P.Alkalic rock carbonatite complexes of the Superior structural province northern Ontario, CanadaChronique de la Recherche Miniere, No. 504, pp. 4-19OntarioAlkaline rocks, Carbonatite
DS1991-1487
1991
Sage, R.P.Sage, R.P.Alkalic rocks, carbonatite and kimberlite complexes of Ontario, SuperiorProvinceOntario Geological Survey Summary of Field Work and Other Activities, Special Volume No. 4, pp. 683-709OntarioCarbonatite -review, Kimberlites -review
DS1991-1488
1991
Sage, R.P.Sage, R.P.Geology of the Martison carbonatite complexOntario Geological Survey Open File, No. 5420, 74pOntarioCarbonatite, Martison
DS1991-1489
1991
Sage, R.P.Sage, R.P., Heather, K.B.The structure, stratigraphy and mineral deposits of the Wawa areaGeological Association of Canada (GAC) Annual Meeting held Toronto May 1991, Guidebook, No. A6, 38pOntarioGeology, Wawa, Structure, Iron
DS1993-1365
1993
Sage, R.P.Sage, R.P.Geology of the Herman Lake alkalic rock complex, District of AlgomaOntario Geological Survey, Open File, No. 5421, 80p.OntarioAlkaline rocks, Carbonatite
DS1993-1366
1993
Sage, R.P.Sage, R.P.Kimberlites in Ontario... project 93-12Ontario Geological Survey Summary of Field Work and other activities, Misc, Paper No. 162, pp. 111-113.OntarioKimberlites, Field study compilation
DS1994-1515
1994
Sage, R.P.Sage, R.P.Kimberlites of OntarioOntario Geological Survey miscellaneous Paper, No. 163, pp. 113-117.OntarioGeochemistry, Kimberlites
DS1996-1243
1996
Sage, R.P.Sage, R.P.Kimberlites of the Lake Timiskaming Structural ZoneOntario Geological Survey Open File, No. 5837, 435p.Ontario, TimiskamingGeology, Tectonics
DS1996-1244
1996
Sage, R.P.Sage, R.P., Lightfoot, P.C., Doherty, W.Bimodal cyclical Archean basalts and rhyolites from the Michipicoten Wawa greenstone belt: geochemical evidencePrecambrian Research, Vol. 76, No. 3-4, Feb. 1, pp. 119-154OntarioMantle, magma lithosphere, Superior Province
DS1996-1245
1996
Sage, R.P.Sage, R.P., Lightfoot, P.C., Doherty, W.Geochemical characteristics of granitoid rocks from within the Archean Michipicoten greenstone belt...WawaPrecambrian Research, Vol. 76, No. 3-4, Feb. 1, pp. 155-190OntarioSource regions, Tectonic evolution
DS1997-0992
1997
Sage, R.P.Sage, R.P., Crabtree, D.The Nicholson ultramafic dike, Wawa Ontario: a preliminary investigationOntario Geological Survey Open File, No. 5955, 111p.Ontario, WawaDike - petrology, Nicholson dike
DS1998-1044
1998
Sage, R.P.Morris, T.F., Crabtree, D., Sage, R.P., Averill, S. A.Types, abundances and distribution of kimberlite indicator minerals in alluvial sediments Wawa KinniwabiJournal of Geochemical Exploration, Vol. 63, No. 3, Oct. pp. 217-236.OntarioGeochemistry - indicators, Deposit - Wawa Kinniwabi Lake area
DS1999-0496
1999
Sage, R.P.Morris, T.F., Sage, R.P., Ayer, J.A.chromium diopside as an indicator of kimberlite: application to overburdenstudies.Geological Association of Canada (GAC) Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC)., Vol. 24, p. 86. abstractOntarioChrome diopsides, Mineralogy, sampling Program
DS1999-0621
1999
Sage, R.P.Sage, R.P.Geraldton Longlac: a target region for kimberlite and or diamond exploratioOntario Geological Survey miscellaneous Paper, No. 169, pp. 237-43.Ontario, WawaGeology, Geraldton Longlac area
DS2000-0688
2000
Sage, R.P.Morris, T.F., Sage, R.P., Crabtree, D.C.Kimberlite, base metal gold and carbonatite exploration targets derived from overburden heavy mineral data.46th. I.l.g.s. Abstract., May 8-13, pp. 41-42. abstractOntario, WawaSampling, Deposit - Killala Lake area
DS2000-0689
2000
Sage, R.P.Morris, T.F., Sage, R.P., Crabtree, D.C., Pitre, S.A.Kimberlite, base metal and gold exploration targets based upon heavy mineral dat a from surficial deposits - Dat a 52Ontario Geological Survey Open File, No. 6013, 114p.OntarioGeochemistry, Killala Lake area
DS2000-0851
2000
Sage, R.P.Sage, R.P.The Sandor diamond occurrence Michipicoten greenstone belt, Wawa Ontario46th. I.l.g.s. Abstract., May 8-13, p. 58.Ontario, WawaDike, Deposit - Sandor noccurrence
DS2001-1001
2001
Sage, R.P.Sage, R.P., Gareau, T.A compilation of references for kimberlite, diamond and related topicsOntario Geological Survey Open file, No. 6067, 117p. MR Data 86, $50.OntarioBibliography
DS2002-1095
2002
Sage, R.P.Morris, T.F., Sage, R.P., Ayer, J.A., Crabtree, D.C.A study in clinopyroxene composition: implications for kimberlite explorationGeochemistry, Exploration, Environment, Analysis, Vol. 2, No. 4, pp. 321-33.OntarioGeochemistry
DS2003-0060
2003
Sage, R.P.Ayer, J.A., Conceicao. R.V., Ketchum, J.W.F., Sage, R.P., Semenyna, L.The timing and petrogenesis of Diamondiferous lamprophyres in the Michipicoten andOntario Geological Survey Open File, No. 6120, pp. 10 1-9.Ontario, Wawa, Lalibert, OhioPetrology - Oasis
DS2003-0298
2003
Sage, R.P.Crabtree, D.C., Morris, T.F., Ayer, J.A., Sage, R.P.The identification of lherzolitic Cr diopsides in kimberlite exploration programs:8 Ikc Www.venuewest.com/8ikc/program.htm, Session 8, POSTER abstractOntarioGeochemistry, mineral chemistry
DS2003-0978
2003
Sage, R.P.Morris, T.F., Sage, R.P., Ayer, J.A., Crabtree, D.C.A study of clinopyroxene composition: implications for kimberlite explorationGeochemistry - Exploration, Environment, Analysis, Vol. 2, part 4, pp. 321-332Ontarioclinopyroxene composition
DS2003-0979
2003
Sage, R.P.Morris, T.F., Sage, R.P., Crabtree, D.C., Ayer, J.A.Summary of clinopyroxene dat a. Depository of dat a related to a number of sources(Ontario Geological Survey Miscellaneous Release, Data 101GlobalGeochemistry
DS200412-0081
2003
Sage, R.P.Ayer, J.A., Conceicao,R.V., Ketchum, J.W.F., Sage, R.P., Semenyna, L., Wyman, D.A.The timing and petrogenesis of Diamondiferous lamprophyres in the Michipicoten and Abitibi greenstone belts.Ontario Geological Survey Open File, No. 6120, pp. 10 1-9.Canada, Ontario, WawaPetrology - Oasis
DS200412-0383
2003
Sage, R.P.Crabtree, D.C., Morris, T.F., Ayer, J.A., Sage, R.P.The identification of lherzolitic Cr diopsides in kimberlite exploration programs: examples from indicator mineral surveys carri8 IKC Program, Session 8, POSTER abstractCanada, OntarioDiamond exploration, geochemistry
DS200612-1550
2006
Sage, R.P.Wyman, D.A., Ayer, J.J., Conceicao, R.V., Sage, R.P.Mantle processes in an Archean orogen: evidence from 2.67 Ga diamond bearing lamprophyres and xenoliths.Lithos, Vol. 89, 3-4, July pp. 300-328.Canada, Ontario, WawaDikes, breccias, subduction, Superior, xenoliths
DS200812-0995
2008
Sage, R.P.Sage, R.P.Prairie Lake carbonatite dat a - geochemical dat a new and unpublished.From author, CD available by his permission sent to me Dec 2007Canada, OntarioCarbonatite, geochemistry
DS201611-2136
2000
Sage, R.P.Sage, R.P., Crabtree, D.C., Morris, T.F.Nicholson ultramafic dike: midcontinent rift and the mantle sample - diamond potential.Sage donated paper file, 35p. Unpubl. Note date 2000Canada, Ontario, WawaLamprophyre
DS201611-2137
2000
Sage, R.P.Sage, R.P., Crabtree, D.C., Thomas, R.D., Morris, T.F.Sandor diamond occurrence: an Archean spessartite lamprophyre Michipicoten greenstone belt, Wawa Ontario.Sage donated paper file, 48p. Unpubl. Pdf Note date 2000Canada, Ontario, WawaLamprophyre
DS1991-1490
1991
Sagers, M.J.Sagers, M.J.Arkhangelsk diamonds given public displaySoviet Geography, Vol. 32, No. 7, September p. 515Russia, ArkangelskNews item, Arkhangelsk
DS1991-1491
1991
Sagers, M.J.Sagers, M.J.One of Yakutia's diamond works to closeSoviet Geography, Vol. 32, No. 9, November pp. 637-638Russia, YakutiaNews item, Diamond mine
DS1960-1019
1968
Saggerson, E.P.Saggerson, E.P.Eclogite Nodules Associated With Alkaline Olivine BasaltsGeologische Rundschau, Vol. 57, PP. 890-903.GlobalXenoliths, Petrography
DS1983-0152
1983
Saggerson, E.P.Bristow, J.W., Saggerson, E.P.A General Account of Karoo Vulcanicity in Southern AfricaGeologische Rundschau, Vol. 72, No. 3, PP. 1015-1060.South Africa, Botswana, Lesotho, Swaziland, Mozambique, ZimbabweRegional Geology
DS1985-0581
1985
Saggerson, E.P.Saggerson, E.P., Turner, L.M.Metamorphic Map of South AfricaGeological Survey SOUTH AFRICA., 1: 1 MILLION.South AfricaBlank
DS1986-0698
1986
Saggerson, T.Saggerson, T.A handbook of mineral under the microscopeUniversity of Natal Press, 50pGlobalp. 19 Garnet group, Mineralogy
DS200512-0756
2005
Sagredo, J.Munoz, M., Sagredo, J., De Ignacio, C., Fernandez-Suarez, J., Jeffries, T.E.New dat a ( U Pb K Ar ) on the geochronology of the alkaline carbonatitic association of Fuerteventura Canary Islands, Spain.Lithos, Advanced in press,Europe, Spain, Canary IslandsCarbonatite, geochronology
DS200612-0325
2006
Sagredo, J.Delgnacio, C., Muoz, M., Sagredo, J., Fernandez, Santan, S., JohanssonIsotope geochemistry and FOZO mantle component of the alkaline carbonatitic association of Fuerteventura, Canary Islands, Spain.Chemical Geology, Vol. 232, 3-4, pp. 99-113.Europe, Spain, Canary IslandsCarbonatite
DS201012-0141
2010
Sagredo, J.De Ignacio, C., Munoz, M., Sagredo, J.Carbonatites and associated nephelinites from Sao Vicente Cape Verde Islands.International Mineralogical Association meeting August Budapest, abstract p. 552.Europe, Cape Verde IslandsCarbonatite
DS201212-0153
2012
Sagredo, J.De Ignacio, C., Munoz, M., Sagredo, J.Carbonatites and associated nephelinites from Sao Vicente, Cape Verde Islands.Mineralogical Magazine, Vol. 76, 2, pp. 311-355.Africa, Cape Verde IslandsCarbonatite
DS2002-0280
2002
SahaChaudhuri, A.K., Saha, Deb, Mukherjee, GhoshThe Purana basins of southern cratonic province of India - a case for mesoproterozoic fossil rifts.Gondwana Research, Vol. 5, No. 1, pp. 23-34.IndiaCraton - rifting, tectonics
DS200412-1720
2004
Saha, A.Saha, A., Basu, A.R., Garzione, C.N., Bandyopadhyay, P.K., Chakrabarti, A.Geochemical and petrological evidence for subduction accretion processes in the Archean eastern Indian Craton.Earth and Planetary Science Letters, Vol. 220, 1-2, March 30, pp. 91-106.IndiaTectonics, petrology, geochronology
DS200512-0927
2005
Saha, A.Saha, A., Basu, A.R., Jacobsen, S.B., Poreda, R.J., Yin, Q.Z., Yogodzinski, G.M.Slab devolatization and Os and Pb mobility in the mantle wedge of the Kamchatka arc.Earth and Planetary Science Letters, Advanced in press,Russia, KamchatkaGeochronology, slab
DS201511-1874
2015
Saha, A.Saha, A., Manikyamba, C., Santosh, M., Ganguly, S., Khelen, A.C.Platinum Group Elements ( PGE) geochemistry of komatiites and boninites from Dharwar Craton, India: implications for mantle melting processes.Journal of Asian Earth Sciences, Vol. 105, pp. 300-319.IndiaBoninites

Abstract: High MgO volcanic rocks having elevated concentrations of Ni and Cr are potential hosts for platinum group elements (PGE) owing to their primitive mantle origin and eruption at high temperatures. Though their higher PGE abundance is economically significant in mineral exploration studies, their lower concentrations are also valuable geochemical tools to evaluate petrogenetic processes. In this paper an attempt has been made to evaluate the PGE geochemistry of high MgO volcanic rocks from two greenstone belts of western and eastern Dharwar Craton and to discuss different mantle processes operative at diverse geodynamic settings during the Neoarchean time. The Bababudan greenstone belt of western and Gadwal greenstone belt of eastern Dharwar Cratons are dominantly composed of high MgO volcanic rocks which, based on distinct geochemical characteristics, have been identified as komatiites and boninites respectively. The Bababudan komatiites are essentially composed of olivine and clinopyroxene with rare plagioclase tending towards komatiitic basalts. The Gadwal boninites contain clinopyroxene, recrystallized hornblende with minor orthopyroxene, plagioclase and sulphide minerals. The Bababudan komatiites are Al-undepleted type (Al2O3/TiO2 = 23-59) with distinctly high MgO (27.4-35.8 wt.%), Ni (509-1066 ppm) and Cr (136-3036 ppm) contents. These rocks have low ?PGE (9-42 ppb) contents with 0.2-2.4 ppb Iridium (Ir), 0.2-1.4 ppb Osmium (Os) and 0.4-4.4 ppb Ruthenium (Ru) among Iridium group PGE (IPGE); and 1.4-16.2 ppb Platinum (Pt), 2.8-19 ppb Palladium (Pd) and 0.2-9.8 ppb Rhodium (Rh) among Platinum group PGE (PPGE). The Gadwal boninites are high-Ca boninites with CaO/Al2O3 ratios varying between 0.8 and 1.0, with 12-24 wt.% MgO, 821-1168 ppm Ni and 2307-2765 ppm Cr. They show higher concentration of total PGE (82-207 ppb) with Pt concentration ranging from 13 to 19 ppb, Pd between 65 and 180 ppb and Rh in the range of 1.4-3 ppb compared to the Bababudan komatiites. Ir, Os and Ru concentrations range from 0.6 to 2.2 ppb, 0.2 to 0.6 ppb and 1.4 to 2.6 ppb respectively in IPGE. The PGE abundances in Bababudan komatiites were controlled by olivine fractionation whereas that in Gadwal boninites were influenced by fractionation of chromite and sulphides. The Al-undepleted Bababudan komatiites are characterized by low CaO/Al2O3, (Gd/Yb)N, (La/Yb)N, with positive Zr, Hf, Ti anomalies and high Cu/Pd, Pd/Ir ratios at low Pd concentrations suggesting the derivation of parent magma by high degrees (>30%) partial melting of mantle under anhydrous conditions at shallow depth with garnet as a residual phase in the mantle restite. The komatiites are geochemically analogous to Al-undepleted Munro type komatiites and their PGE compositions are consistent with Alexo and Gorgona komatiites. The S-undersaturated character of Bababudan komatiites is attributed to decompression and assimilation of lower crustal materials during magma ascent and emplacement. In contrast, the higher Al2O3/TiO2, lower (Gd/Yb)N, for Gadwal boninites in combination with negative Nb, Zr, Hf, Ti anomalies and lower Cu/Pd at relatively higher Pd/Ir and Pd concentrations reflect high degree melting of refractory mantle wedge under hydrous conditions in an intraoceanic subduction zone setting. Higher Pd/Ir ratios and S-undersaturation of these boninites conform to influx of fluids derived by dehydration of subducted slab resulting into high fluid pressure and metasomatism of mantle wedge.
DS201707-1361
2017
Saha, A.Saha, A., Ganguly, S., Ray, J., Koeberl, C., Thoni, M., Sarbajna, C., Sawant, S.S.Petrogenetic evolution of Cretaceous Samchampi Samteran alkaline complex, Mikir Hills, northeast India: implications on multiple melting events of heterogeneous plume and metasomatized sub continental lithospheric mantle.Gondwana Research, Vol. 48, pp. 237-256.Indiacarbonatite

Abstract: The Samchampi (26° 13?N: 93° 18?E)-Samteran (26° 11?N: 93° 25?E) alkaline complex (SSAC) occurs as an intrusion within Precambrian basement gneisses in the Karbi-Anglong district of Assam, Northeastern India. This intrusive complex comprises a wide spectrum of lithologies including syenite, ijolite-melteigite, alkali pyroxenite, alkali gabbro, nepheline syenite and carbonatite (nepheline syenites and carbonatites are later intrusives). In this paper, we present new major, trace, REE and Sr-Nd isotope data for different lithologies of SSAC and discuss integrated petrological and whole rock geochemical observations with Sr-Nd isotope systematics to understand the petrogenetic evolution of the complex. Pronounced LILE and LREE enrichment of the alkaline-carbonatite rocks together with steep LREE/HREE profile and flat HREE-chondrite normalized patterns provide evidence for parent magma generation from low degree partial melting of a metasomatized garnet peridotite mantle source. LILE, HFSE and LREE enrichments of the alkaline-silicate rocks and carbonatites are in agreement with the involvement of a mantle plume in their genesis. Nb-Th-La systematics with incompatible trace element abundance patterns marked by positive Nb-Ta anomalies and negative K, Th and Sr anomalies suggest contribution from plume-derived OIB-type mantle with recycled subduction component and a rift-controlled, intraplate tectonic setting for alkaline-carbonatite magmatism giving rise to the SSAC. This observation is corroborated by enriched 87Sr/86Srinitial (0.705562 to 0.709416) and 143Nd/144Ndinitial (0.512187 to 0.512449) ratios for the alkaline-carbonatite rocks that attest to a plume-related enriched mantle (~ EM II) source in relation to the origin of Samchampi-Samteran alkaline complex. Trace element chemistry and variations in isotopic data invoke periodic melting of an isotopically heterogeneous, metasomatized mantle and generation of isotopically distinct melt batches that were parental to the different rocks of SSAC. Various extents of plume-lithosphere interaction also accounts for the trace element and isotopic variations of SSAC. The Srinitial and Ndinitial (105 Ma) isotopic compositions (corresponding to ?Nd values of ? 6.37 to ? 1.27) of SSAC are consistent with those of Sung Valley, Jasra, Rajmahal tholeiites (Group II), Sylhet Traps and Kerguelen plateau basalts.
DS2000-0667
2000
Saha, B.Mishra, B.K., Saha, B.Regional search for lamproite kimberlite in Tapti lineament zone in Raigarh, Jashpur and Surguja districts of Madhra Pradesh. P -II stage.Geological Society of India Records, Vol. 133,6,pp. 127-9.India, Madhya PradeshKimberlite, lamproite geology
DS201212-0452
2012
Saha, D.Mazunder, R., Saha, D.Paleoproterozoic of India.Geological Society of London Special Publication, no. 365, 300p.IndiaBook - paleoproterozoic
DS201312-0770
2014
Saha, D.Saha, D., Patranabis-Deb, S.Kimberlite: rapid ascent of lithospherically modified carbonatitic melts.Journal of Asian Earth Studies, Vol. 91, pp. 230-251.IndiaTectonics
DS201412-0769
2014
Saha, D.Saha, D., Patranabis-Deb, S.Proterozoic evolution of eastern Dharwar and Bastar cratons, India - an overview of the intracratonic basins, craton margins and mobile belts.Journal of Asian Earth Sciences, Vol. 91, pp. 230-251.IndiaCraton
DS202011-2041
2013
Saha, D.Henderson, B., Collins, A.S., Payne, J., Forbes, C., Saha, D.Geological and geochemistry constraining India in Columbia: the age, isotopic provenance and geochemistry of the protoliths of the Ongole Domain, southern eastern Ghats, India. *** NOTE DATEGondwana Research, in press available. 19p. PdfIndiaNuna

Abstract: The Ongole Domain in the southern Eastern Ghats Belt of India formed during the final stages of Columbia amalgamation at ca. 1600 Ma. Yet very little is known about the protolith ages, tectonic evolution or geographic affinity of the region. We present new detrital and igneous U-Pb-Hf zircon data and in-situ monazite data to further understand the tectonic evolution of this Columbia-forming orogen. Detrital zircon patterns from the metasedimentary rocks are dominated by major populations of Palaeoproterozoic grains (ca. 2460, 2320, 2260, 2200-2100, 2080-2010, 1980-1920, 1850 and 1750 Ma), and minor Archaean grains (ca. 2850, 2740, 2600 and 2550 Ma). Combined U-Pb ages and Lu-Hf zircon isotopic data suggest that the sedimentary protoliths were not sourced from the adjacent Dharwar Craton. Instead they were likely derived from East Antarctica, possibly the same source as parts of Proterozoic Australia. Magmatism occurred episodically between 1.64 and 1.57 Ga in the Ongole Domain, forming felsic orthopyroxene-bearing granitoids. Isotopically, the granitoids are evolved, producing ?Hf values between ? 2 and ? 12. The magmatism is interpreted to have been derived from the reworking of Archaean crust with only a minor juvenile input. Metamorphism between 1.68 and 1.60 Ga resulted in the partial to complete resetting of detrital zircon grains, as well as the growth of new metamorphic zircon at 1.67 and 1.63 Ga. In-situ monazite geochronology indicates metamorphism occurred between 1.68 and 1.59 Ga. The Ongole Domain is interpreted to represent part of an exotic terrane, which was transferred to proto-India in the late Palaeoproterozoic as part of a linear accretionary orogenic belt that may also have included south-west Baltica and south-eastern Laurentia. Given the isotopic, geological and geochemical similarities, the proposed exotic terrane is interpreted to be an extension of the Napier Complex, Antarctica, and may also have been connected to Proterozoic Australia (North Australian Craton and Gawler Craton).
DS200612-1208
2006
Saha, D.K.Sakar, R.K., Saha, D.K.A note on the lithosphere thickness and heat flow density of the Indian Craton from MAGSAT data.Acta Geophysica, Vol. 54, 2, June pp. 198-204.IndiaGeothermometry
DS202007-1176
2019
Saha, G.Saha, G., Rai, S,S., ShalivahanOccurrence of diamond in peninsular India and its relationship with deep Earth seismic properties.Journal of Earth System Science, Vol. 128, 43, 8p. PdfIndiageophysics, seismics

Abstract: An improved shear wave velocity (Vs) structure of the lithosphere of peninsular India using the surface wave tomography from the ambient noise and earthquake waveforms suggests its bipolar character. While most of the geological domains of India are characterised by a uniform lithospheric mantle of Vs?4.5 km/s, the three cratonic regions, eastern Dharwar, Bastar and Singhbhum, hosting most of the diamondiferous kimberlite fields, show significantly high Vs of 4.7 km/s and above in their lower lithosphere beyond ?90 km depth. The higher velocity could best be explained by the presence of diamond and/or eclogite along with peridotite in mantle. This unique relationship suggests the regional seismic image of lithosphere as a guide for exploration of diamonds.
DS2002-1380
2002
Saha, I.Saha, I., Venkatesh, A.S.Invisible gold within sulphides from the Archean Hutti Maski schist belt, southern IndiaJournal of Asian Earth Sciences, Vol.20,5,pp. 449-57.IndiaGold, copper, Mesothermal, Deposit - Hutti Maski
DS2000-0234
2000
Saha, J.C.Dikshit, A.K., Pallamreddy, K., Saha, J.C.Arsenic in groundwater and its sorption by kimberlite tailingsJournal of Environ. Science and Health, pt.A Environ. Vol. 35, No. 1, pp. 65-GlobalMineral processing
DS201012-0650
2010
Saha, L.Saha, L., Pant, N.C., Pati, J.K., Upadhyay, D., Berndt, J., Bhattacharya, A., Satynarayanan, M.Neoarchean high pressure margarite phengite muscovite chlorite corona mantle corundum in quartz free high Mg, Al phlogopite chlorite schists from the BundelkhandContributions to Mineralogy and Petrology, in press available, 20p.IndiaCraton, U H metamorphism
DS201112-0771
2011
Saha, L.Pati, J.K., Saha, L.Mesoarchean tectono-metamorphic event from Bundelk hand craton, central India.Goldschmidt Conference 2011, abstract p.1606.IndiaMetamorphism
DS201511-1875
2015
Saha, L.Saha, L., Frei, D., Gerdes, A., Pat, J.K., Sarkar, S., Patole, V., Bhandari, A., Nasipuri, P.Crustal geodynamics from the Archean Bundelk hand craton, India: constraints from zircon U-Pb-Hf isotope studies.Geological Magazine, Rapid communication Oct. 14p.IndiaTectonics, geochronology

Abstract: A comprehensive study based on U-Pb and Hf isotope analyses of zircons from gneisses has been conducted along the western part (Babina area) of the E–W-trending Bundelkhand Tectonic Zone in the central part of the Archaean Bundelkhand Craton. 207Pb-206Pb zircon ages and Hf isotopic data indicate the existence of a felsic crust at ~ 3.59 Ga, followed by a second tectonothermal event at ~ 3.44 Ga, leading to calc-alkaline magmatism and subsequent crustal growth. The study hence suggests that crust formation in the Bundelkhand Craton occurred in a similar time-frame to that recorded from the Singhbhum and Bastar cratons of the North Indian Shield.
DS201602-0234
2016
Saha, L.Saha, L., Frei, D., Gerdes, A., Pati, J.K., Sarkar, S., Patole, V., Bhandari, A., Nasipuri, P.Crustal geodynamics from the Archean Bundelk hand Craton, India: constraints from zircon U-Pb-Hf isotope studies.Geological Magazine, Vol. 153, 1, pp. 179-192.IndiaGeochronology, tectonics

Abstract: A comprehensive study based on U-Pb and Hf isotope analyses of zircons from gneisses has been conducted along the western part (Babina area) of the E-W-trending Bundelkhand Tectonic Zone in the central part of the Archaean Bundelkhand Craton. 207Pb-206Pb zircon ages and Hf isotopic data indicate the existence of a felsic crust at ~ 3.59 Ga, followed by a second tectonothermal event at ~ 3.44 Ga, leading to calc-alkaline magmatism and subsequent crustal growth. The study hence suggests that crust formation in the Bundelkhand Craton occurred in a similar time-frame to that recorded from the Singhbhum and Bastar cratons of the North Indian Shield.
DS201904-0780
2019
Saha, S.Sinha, S.T., Saha, S., Longacre, M., Basu, S., Jha, R., Mondal, T.Crustal architecture and nature of continental breakup along a transform margin: new insights from Tanzania-Mozambique margin.Tectonics, in press availableAfrica, Tanzania, Mozambiquerifting

Abstract: The Tanzania?North Mozambique continental margin is a transform segment associated with Davie Fracture Zone (DFZ). The DFZ is described as an elongated linear oceanic fracture zone, commonly linked with the breakup between Eastern and Western Gondwana. We conducted a synthesized study using gravity, magnetic and seismic data presenting the crustal architecture, geometry and the kinematic nature of continental breakup along a transform margin. The Crustal nature of DFZ, its role in forming kinematic linkage between two extensional margins during continental breakup processes is focus of our study. The two extensional margins, Somalia?Majunga and North Mozambique?Antarctica were linked via a 2600 km long dextral transform segment, partially overlapping with DFZ. Absence of classical rift indicators, weak signs of hyperextension, abrupt ocean?continent boundary (OCB) suggests transform margin architecture. We redefined this feature as the Davie Transform System (DTS). The nature of deformation varies form transtensional pull?apart in Tanzania to almost pure strike?slip in North Mozambique. The southern transform segment exhibits abrupt change in ocean continent transition with a narrow zone of continental extension. This variation is recognized through the newly interpreted OCB along this entire transform segment. Notably, within large pull?apart systems in the north, presence of fossilized incipient spreading center suggest that the extension had reached at quite advanced stages, characterized by significant thermal weakening as a consequence of strong magmatic activity. Through a series of reconstruction snapshots, we show the geodynamic evolution along the Tanzania?North Mozambique margin explaining the role of DTS in the southward movement of Madagascar.
DS201912-2820
2019
Saha, S.Saha, S., Dasgupta, R.Phase relations of a depleted peridotite fluxed by CO2-H2O fluid - implications for the stability of partial melts versus volatile bearing mineral phases in the cratonic mantle.Journal of Geophysical Research: Solid Earth, Vol. 124, 10, pp. 10089-10106.Mantleperidotite

Abstract: We present phase?equilibria experiments of a K?bearing, depleted peridotite (Mg# 92) fluxed with a mixed CO2?H2O fluid (0.5 wt.% CO2 and 0.94 wt.% H2O in the bulk) to gain insight into the stability of volatile?bearing partial melts versus volatile?bearing mineral phases in a depleted peridotite system. Experiments were performed at 850-1150 °C and 2-4 GPa using a piston?cylinder and a multianvil apparatus. Olivine, orthopyroxene, clinopyroxene, and spinel/garnet are present at all experimental conditions. Textural confirmation of partial melt is made at temperatures as low as 1000 °C at 2 GPa, 950 °C at 3 GPa, and 1000 °C at 4 GPa marking the onset of melting at 900-1000 °C at 2 GPa, 850-950 °C at 3 GPa, and 950-1000 °C at 3 GPa. Phlogopite and magnesite breakdown at 900-1000 °C at 2 GPa, 950-1000 °C at 3 GPa, and 1000-1050 °C at 4 GPa. Comparison with previously published experiments in depleted peridotite system with identical CO2?H2O content introduced via a silicic melt show that introduction of CO2?H2O as fluid lowers the temperature of phlogopite breakdown by 150-200 °C at 2-4 GPa and stabilizes partial melts at lower temperatures. Our study thus, shows that the volatile?bearing phase present in the cratonic mantle is controlled by bulk composition and is affected by the process of volatile addition during craton formation in a subduction zone. In addition, volatile introduction via melt versus aqueous fluid, leads to different proportion of anhydrous phases such as olivine and orthopyroxene. Considering the agent of metasomatism is thus critical to evaluate how the bulk composition of depleted peridotite is modified, leading to potential stability of volatile?bearing phases as the cause of anomalously low shear wave velocity in mantle domains such as mid lithospheric discontinuities beneath continents.
DS202005-0757
2020
Saha, S.Patranabis-Deb, S., Saha, S.Geochronology, paleomagnetic signature and tectonic models of cratonic basins of India in the backdrop of supercontinent amalgamation and fragmentation.Episodes ( IUGS), Vol. 43, 1, pp. 145-163.Indiacraton

Abstract: The Proterozoic cratonic basins of peninsular India preserve records of repeated opening and closing of rifts along the zone of Neoarchean sutures and/or along the weak zones. These sedimentary basins, ranging in age from late Palaeoproterozoic through Neoproterozoic are traditionally referred to as Purana basins in Indian literature. The successions of each of the basins may be represented by successive unconformity-bound sequences, which represent several cycles of fluvialshallow marine to shelf-slope-basin sedimentation punctuated by local hiatuses and/or volcanic upheavals. The advance retreat of ancient seaways and their complex are recorded in the sedimentary successions of Purana basins. Papaghni-Chitravati; Kaladgi-Badami; Lower Vindhyan record the oldest cycle of sedimentation. These basins opened after 2.0 Ga and closed by 1.55 Ga. The Chattisgarh and its satellite basins, namely Indravati; Khariar; Ampani opened after the 1.6 Ga. and closed shortly after the 1000 Ma. Albaka; Mallampalli; Kurnool; Bhima preserve Neoproterozoic sedimentation history. The upper Vindhyan basin likely opened after 1.4 Ga. and continued through the Neoproterozoic. The sequence of events indicates a close relationship of craton interior histories with plate tectonics and variations in the heat flow regime underneath the continental crust. Periods of formation of the cratonic basins are coincident with the amalgamation or fragmentation of supercontinents further indicates genetic linkage between the two processes. Synchronous development of the cratonic basins with closely comparable stratigraphy and basin development events, in different small continents, strengthens the view that basin formation processes operated on a global scale, and stratigraphic basin analysis on a regional scale is a significant tool in evaluating the basins’ history. The available stratigraphic, geochronologic or palaeomagnetic data from India is still inadequate, and further information is required to constrain its definite position in the context of global tectonics.
DS202012-2247
2021
Saha, S.Saha, S., Peng, Y., Dasgupta, R., Mookherjee, M., Fischer, K.M.Assessing the presence of volatile-bearing mineral phases in the cratonic mantle as a possible cause of mid-lithospheric discontinuities.Earth and Planetary Letters, Vol.. 553, 116602, 12p. PdfMantlecratons

Abstract: A number of possible hypotheses have been proposed to explain the origin of mid-lithospheric discontinuities (MLDs), typically characterized by ?2-6% reductions in seismic shear wave velocity (VS) at depths of 60 km to ?150 km in the cratonic sub-continental lithospheric mantle (SCLM). One such hypothesis is the presence of low-shear wave velocity, hydrous and carbonate mineral phases. Although, the presence of hydrous silicates and carbonates can cause a reduction in the shear wave velocity of mantle domains, the contribution of volatile metasomatism to the origins of MLDs has remained incompletely evaluated. To assess the metasomatic origin of MLDs, we compiled experimental phase assemblages, phase proportions, and phase compositions from the literature in peridotite + H2O, peridotite + CO2, and peridotite + H2O + CO2 systems at P-T conditions where hydrous silicate and/or carbonate minerals are stable. By comparing the experimental assemblages with the compiled bulk peridotite compositions for cratons, we bracket plausible proportions and compositions of hydrous silicate and carbonate mineral phases that can be expected in cratonic SCLMs. Based on the CaO and K2O contents of cratonic peridotite xenoliths and the estimated upper limit of CO2 content in SCLM, ??10 vol.% pargasitic amphibole, ??2.1 vol.% phlogopite and ??0.2 vol.% magnesite solid solution can be stable in the SCLM. We also present new elasticity data for the pargasite end member of amphibole based on first principles simulations for more accurate estimates of aggregate VS for metasomatized domains in cratonic mantle. Using the bracketed phase compositions, phase proportions, and updated values of elastic constants for relevant mineral end members, we further calculate aggregate VS at MLD depths for three seismic stations in the northern continental U.S. Depending on the choice of background wave speeds of unmetasomatized peridotite and the cratonic geotherm, the composition and abundance of volatile-bearing mineral phases bracketed here can explain as much as 2.01 to 3.01% reduction in VS. While various craton formation scenarios allow formation of the amphibole and phlogopite abundances bracketed here, presence of volatile-bearing phases in an average cratonic SCLM composition cannot explain the entire range of velocity reductions observed at MLDs. Other possible velocity reduction mechanisms thus must be considered to explain the full estimated range of shear wave speed reduction at MLD depths globally.
DS200412-0353
2004
Sahabi, J.Contrucci, I., Klingelhofer, J., Perrot, R., Bartolome, M.A., Gutscher, M., Sahabi, J., Malod, J.P.The crustal structure of the NW Moroccan continental margin from wide angle reflection seismic data.Geophysical Journal International, Vol. 159, 1, pp. 117-128.Africa, MoroccoGeophysics - seismics, Tectonics
DS1985-0572
1985
Sahagian, D.Rowley, D.B., Ziegler, A.M., Sahagian, D., Nie, S.Y., Lottes, A.Geological and Geometrical Constraints on Reconstructions OfGeological Society of America (GSA), Vol. 17, No. 7, P. 703. (abstract.).South Africa, India, AustraliaGeotectonics
DS1988-0605
1988
Sahagian, D.Sahagian, D.Epeirgenic motions of Africa as inferred from CretaceousshorelinedepositsTectonics, Vol. 7, No. 1, February pp. 125-138AfricaBlank
DS2002-1381
2002
Sahagian, D.Sahagian, D., Proussevitch, A., Carlson, W.Timing of Colorado Plateau uplift: initial constraints from vesicular basalt derived paleoelevations.Geology, Vol. 30,9,Sept. pp. 807-10.Colorado PlateauBasalts - uplift - not specific to diamonds
DS1993-1367
1993
Sahagian, D.L.Sahagian, D.L.Structural evolution of African basins: stratigraphic synthesisBasin Research, Vol. 5, No. 1, March pp. 41-54.AfricaBasins, Structure
DS1993-1368
1993
Sahagian, D.L.Sahagian, D.L.Structural evolution of African basins: stratigraphic synthesisBasin Research, Vol. 5, No. 1, March pp. 41-54South AfricaTectonics, Structure -basins
DS200912-0667
2009
Sahakyan, L.H.Satian, M.A., Sahakyan, L.H., Stepanyan, O.Composition of tuffs from lamprophyre diatremes of the Vedi Rift, Armenia.Lithology and Mineral Resources, Vol. 44, 4, pp. 399-409.Africa, ArmeniaLamprophyre
DS1940-0100
1945
Sahama, TH. G.Sahama, TH. G.Spurenelemente der Gesteine im Sudlichen Finnisch-laplandBulletin. COMM. GEOL. FINLANDE., No. 135GlobalMineralogy, Trace Elements, Carbonatite
DS1970-0984
1974
Sahama, TH. G.Sahama, TH. G.Potassium Rich Alkaline Rocks With CommentsNew York: John Wiley And Sons, The Alkaline Rocks, Petrography, PP. 96-109.GlobalLeucite, Leucitite, Related Rocks
DS1970-0404
1971
Sahasrabudhe, Y.S.Sahasrabudhe, Y.S.Possibilities of Finding Diamonds in Maharashtra StateIndia Geological Survey Miscellaneous Publishing, No. 19, PP. 49-53.India, MaharashtraProspecting, Genesis, History
DS2001-1002
2001
Sahin, A.Sahin, A.Global estimates of ore reserves in a beach sand depositThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin) ., Vol. 94, No. 1027, Feb. pp. 43-6.Sierra LeoneAlluvials - not specific to diamonds, Geostatistics
DS1998-0590
1998
Sahm, W.C.Harrod, G.R., Sahm, W.C.Mining information goes 'Real Time'Society for Mining, Metallurgy and Exploration (SME) Preprint, No. 98-113GlobalEconomics, Information - mining
DS2001-0786
2001
Sahoo, H.K.Mohanty, M., Sahoo, H.K.Detailed survey to locate kimberlite/lamproite pipes in already identified blocks, Bolangir Baragarh and Kalahandi districts, Orissa.Records of the Geological Survey of India, Vol. 132, 3, eastern 1997-1998, pp.212-213.India, OrissaGeochemistry
DS2002-1401
2002
Sahoo, H.K.Sarangi, B., Sahoo, H.K.Detailed survey to locate kimberlite/lamproite pipes already identified blocks in Bolangir Baragarh and Kalandi Districts, Orissa.Records of the Geological Survey of India, Vol. 133, 3, eastern 1998-1999, pp.193-195.India, OrissaGeochemistry
DS200412-1346
2001
Sahoo, H.K.Mohanty, M., Sahoo, H.K.Detailed survey to locate kimberlite/lamproite pipes in already identified blocks, Bolangir Baragarh and Kalahandi districts, OrRecords of the Geological Survey of India, Vol. 132, 3, eastern 1997-1998, pp.212-213.India, OrissaGeochemistry
DS200412-1730
2002
Sahoo, H.K.Sarangi, B., Sahoo, H.K.Detailed survey to locate kimberlite/lamproite pipes already identified blocks in Bolangir Baragarh and Kalandi Districts, OrissRecords of the Geological Survey of India, Vol. 133, 3, eastern 1998-1999, pp.193-195.India, OrissaGeochemistry
DS200612-0941
2001
Sahoo, K.C.Mohanty, M., Sahoo, K.C., Rath, S.C.Ong River basin in Orissa: a possible target for diamond investigation.National Seminar on Exploration Survey, Geological Society of India Special Publication, No. 58, pp. 635-646.India, OrissaDiamond exploration
DS1986-0699
1986
Sahoo, N.Sahoo, N., Mishra, K.C., Das, T.P., Schmidt, P.C.Vacancy associated model for anomalous muonium in diamond, silicon andgermaniuM.Hyperfine Interact, Vol. 32, No. 1-4, pp. 619-624GlobalCrystallography, Diamond
DS1989-1325
1989
Sahoo, N.Sahoo, N.Theory of structure and hyperfine properties of anomalous muonium inPhys. Rev. B., Vol. 39, No. 18, June 15, pp. 3389-3410GlobalDiamond synthesis, Muonium/germaniuM.
DS201801-0002
2017
Sahoo, P.Balasubramani, S., Sahoo, P., Bhattacharya, D., Rengarajan, M., Thangavel, S., Bhatt, A.K., Verma, M.B., Nanda, L.K.A note on anomalous concentration of scandium in the Pakkanadu alkaline complex, Salem District, Tamil Nadu, India.Carbonatite-alkaline rocks and associated mineral deposits , Dec. 8-11, abstract p. 46.Indiaalkaline rocks

Abstract: Pakkanadu Alkaline complex (PAC) of Neoproterozoic age is located at the southwestern end of Dharmapuri rift/shear zone on the northern part of southern granulitic terrain in Tamil Nadu, India. PAC mainly comprises carbonatite-syenitepyroxenite suite of rocks. Syenite is the predominant rock exposed on the eastern and western part of the explored area with enclaves of pyroxenite and dunite. The carbonatite (sovite) occurs as thin veins/bands and discontinuous lenticular bodies intrusive into highly deformed biotite schist that is considered as the fenitised product of pyroxenite traceable over a strike length of 1.5 km. Petromineralogical study of the biotite schist, pyroxenite containing carbonatite rock and carbonatite indicated presence of monazite, allanite, sphene and betafite as the main radioactive minerals occurring as inclusion within biotite or as discrete mineral grains. Other ore minerals are apatite, thorite, titanite, rutile and barite. Chloritisation, hematitisation, silicification and calcitisation are the main wall rock alteration observed in pyroxenite and syenite. Sub-surface exploration carried out by Atomic Minerals Directorate (AMD) in PAC revealed that biotite schist (n=166) contains anomalously high concentration of Scandium (11-1275 ppm, av.161 ppm), REE (67-58275 ppm, av. 14836 ppm,) and V (5-620 ppm, av. 127 ppm, with carbonatite veins and syenite (n=149) contain scandium (10-462 ppm, av.71 ppm,), REE (18-57510 ppm, av. 4106 ppm) and V (1-285 ppm, av. 48 ppm). In these rocks, LREE (12.5-57670 ppm, av. 9617 ppm, n=315) shows enrichment over HREE (7.1-774 ppm, av. 173 ppm, n=315). The concentration of Scandium (Av. 166 and 71 ppm in biotite schist and syenite respectively) is anomalous as compared to its crustal abundance (22 ppm). Geochemical analyses of the rock indicate that the radioactive biotite schist, pyroxenite containing carbonatite veins generally shows higher Sc and REE concentrations as compared to those of the other rocks (syenite). However, there is no significant correlation between REE and Sc. The higher concentration of scandium in PAC is possibly due to selective partitioning of it into minerals like apatite, pyrochlore, allanite, monazite and other REE bearing phases, apart from its concentration in the ferromagnesian minerals. Scandium rarely concentrates in nature as independent ore mineral. The demand for the metal is very high due to multiple high value commercial uses as an alloy with aluminum, specifically in aerospace and automobile industry, besides, in solid oxide fuel cells (SOFC) in electrical industries. Eight boreholes drilled as part of the preliminary subsurface exploration in PAC, covering an area of 0.05 sq. km, indicated an elevated Scandium content of about 6 times that of the average crustal abundance.
DS201701-0001
2016
Sahoo, R.K.Adhikary, D., Sahoo, R.K., Maurya, N.Petrography and geochemistry of new finding alkaline lamprophyre dyke in eastern margin of the eastern Dharwar craton, near Khammam, Telangana India.Acta Geologica Sinica, Vol. 90, 1, p. 197. abstractIndiaLamprophyre
DS201412-0116
2014
Sahoo, S.Chalapathi Rao, N.V., Kumar, A., Sahoo, S., Dongre, A.N., Talukdar, D.Petrology and petrogenesis of Mesoproterozoic lamproites from the Ramadugu field NW margin of the Cuddapah basin, eastern Dharwar craton, southern India.Lithos, Vol. 196-197, pp. 150-168.IndiaLamproite
DS201508-0346
2015
Sahoo, S.Chalapathi Rao, N.V., Atiullah, Kumar, A., Sahoo, S., Nanda, P., Chahong, N., Lehmann, B., Rao, K.V.S.Petrogenesis of Mesoproterozoic lamproite dykes from the Garledinne (Banganapalle) cluster, south western Cuddapah Basin, southern India.Mineralogy and Petrology, in press available 22p.IndiaLamproite

Abstract: We report mineral chemistry and whole-rock major and trace-element geochemistry for a recent find of Mesoproterozoic (~1.4 Ga) lamproites from the Garledinne (Banganapalle) cluster, south-western part of the Paleo-Mesoproterozoic Cuddapah Basin, southern India. The Garledinne lamproites occur as WNW-ESE-trending dykes that have undergone varying degree of pervasive silicification and carbonate alteration. Nevertheless, their overall texture and relict mineralogy remain intact and provide important insights into the nature of their magmas. The lamproite dykes have porphyritic to weakly porphyritic textures comprising pseudomorphed olivine macrocrysts and microphenocrysts, titanian phlogopite microphenocrysts, spinel having a compositional range from chromite to rarely magnesiochromite, Sr-rich apatite and niobian rutile. The Garledinne and other Cuddapah Basin lamproites (Chelima and Zangamarajupalle) collectively lack sanidine, clinopyroxene, potassic richterite, and titanite and are thus mineralogically distinct from the nearby Mesoproterozoic lamproites (Krishna and Ramadugu) in the Eastern Dharwar Craton, southern India. The strong correlation between various major and trace elements coupled with high abundances of incompatible and compatible trace elements imply that alteration and crustal contamination have had a limited effect on the whole-rock geochemistry (apart from K2O and CaO) of the Garledinne lamproites and that olivine fractionation played an important role in their evolution. The Garledinne lamproites represent small-degree partial melts derived from a refractory (previously melt extracted) peridotitic mantle source that was subsequently metasomatised (enriched) by carbonate-rich fluids/melts within the garnet stability field. The involvement of multiple reservoirs (sub-continental lithospheric mantle and asthenosphere) has been inferred in their genesis. The emplacement of the Garledinne lamproites is linked to extensional events, across the various Indian cratons, related to the break-up of the Proterozoic supercontinent of Columbia.
DS201601-0010
2015
Sahoo, S.Chalapathai Rao, N.V., Atiullah, Burgess, A.R.,Nanda, P., Choudhary, A.K., Sahoo, S., Lehman, B., Chahong, N.Petrology, 40Ar/39Ar, Sr-Nd isotope systematics, and geodynamic significance of an ultrapotassic ( lamproitic) dyke with affinities to kamafugite from the easternmost margin of the Bastar Craton, India.Mineralogy and Petrology, in press available, 25p.IndiaLamproites - Nuapada field

Abstract: We report the mineralogy, bulk-rock geochemistry, 40Ar/39Ar (whole-rock) age and radiogenic (Sr and Nd) isotope composition of an ultrapotassic dyke from Sakri (Nuapada lamproite field) located at the tectonic contact between the easternmost margin of the Bastar craton and Eastern Ghats Mobile Belt, India. The Sakri dyke has a mineralogy which strongly resembles a lamproite sensu stricto (viz.,Ti-rich phlogopite, Na-poor diopside, Fe-rich sanidine, ulvospinel trend and Sr-rich apatite). However, its bulk-rock major element geochemical characteristics (viz., extreme silica-undersaturated nature) resemble sensu lato kamafugite from Toro Ankole, Uganda, East African Rift, and Alto Paranaiba Province, Brazil. The Sakri dyke also displays certain compositional peculiarities (viz., high degree of evolution of mica composition from phlogopite to biotite, elevated titanium and aluminum in clinopyroxene and significantly lower bulk Mg#) when compared to the ultrapotassic rocks from various Indian cratons. 40Ar/39Ar dating gave a plateau age of 1045?±?9 Ma which is broadly similar to that of other Mesoproterozoic (i) lamproites from the Bastar and Bundelkhand cratons, and (ii) kimberlites from the Eastern Dharwar craton. Initial bulk-rock Sr (0.705865-0.709024) and Nd (0.511063-0.511154) isotopic ratios reveal involvement of an ‘enriched’ source region with long-term incompatible element enrichment and a depleted mantle (TDM) Nd model age of 2.56 Ga straddling the Archaean-Proterozoic chronostratigraphic boundary. The bulk-rock incompatible trace element ratios (Ta/Yb, Th/Yb, Rb/Ba and Ce/Y) of the Sakri ultrapotassic dyke negate any significant influence of crustal contamination. Small-degree melting (1 to 1.5 %) of a mixed garnet-facies and spinel-facies phlogopite lherzolite can account for its observed REE concentrations. Whereas the emplacement of the Sakri ultrapotassic dyke is related to the amalgamation of the supercontinent of Rodinia, its overlapping geochemical characteristics of lamproite and kamafugite (also displayed by two other lamproites of the Nuapada field at Amlidadar and Parkom) are linked to the emplacement in a unique geological setting at the craton-mobile belt contact and hence of geodynamic significance.
DS201604-0598
2016
Sahoo, S.Chalapathi Rao, N.V., Atiullah, Burgess, R., Nanda, P., Choudhary, A.K., Sahoo, S., Lehmann, B., Chahong, N.Petrology, 40Ar/39Ar age, Sr-Nd isotope systematics, and geodynamic significance of an ultrapotassic ( lamproitic) dyke with affinities to kamafugite from the easternmost margin of the Bastar Craton, India.Mineralogy and Petrology, in press available, 25p.IndiaDeposit - Sakri Nuapada

Abstract: We report the mineralogy, bulk-rock geochemistry, 40Ar/39Ar (whole-rock) age and radiogenic (Sr and Nd) isotope composition of an ultrapotassic dyke from Sakri (Nuapada lamproite field) located at the tectonic contact between the easternmost margin of the Bastar craton and Eastern Ghats Mobile Belt, India. The Sakri dyke has a mineralogy which strongly resembles a lamproite sensu stricto (viz.,Ti-rich phlogopite, Na-poor diopside, Fe-rich sanidine, ulvospinel trend and Sr-rich apatite). However, its bulk-rock major element geochemical characteristics (viz., extreme silica-undersaturated nature) resemble sensu lato kamafugite from Toro Ankole, Uganda, East African Rift, and Alto Paranaiba Province, Brazil. The Sakri dyke also displays certain compositional peculiarities (viz., high degree of evolution of mica composition from phlogopite to biotite, elevated titanium and aluminum in clinopyroxene and significantly lower bulk Mg#) when compared to the ultrapotassic rocks from various Indian cratons. 40Ar/39Ar dating gave a plateau age of 1045?±?9 Ma which is broadly similar to that of other Mesoproterozoic (i) lamproites from the Bastar and Bundelkhand cratons, and (ii) kimberlites from the Eastern Dharwar craton. Initial bulk-rock Sr (0.705865-0.709024) and Nd (0.511063-0.511154) isotopic ratios reveal involvement of an ‘enriched’ source region with long-term incompatible element enrichment and a depleted mantle (TDM) Nd model age of 2.56 Ga straddling the Archaean-Proterozoic chronostratigraphic boundary. The bulk-rock incompatible trace element ratios (Ta/Yb, Th/Yb, Rb/Ba and Ce/Y) of the Sakri ultrapotassic dyke negate any significant influence of crustal contamination. Small-degree melting (1 to 1.5 %) of a mixed garnet-facies and spinel-facies phlogopite lherzolite can account for its observed REE concentrations. Whereas the emplacement of the Sakri ultrapotassic dyke is related to the amalgamation of the supercontinent of Rodinia, its overlapping geochemical characteristics of lamproite and kamafugite (also displayed by two other lamproites of the Nuapada field at Amlidadar and Parkom) are linked to the emplacement in a unique geological setting at the craton-mobile belt contact and hence of geodynamic significance.
DS201805-0976
2018
Sahoo, S.Sharma, A., Kunar, D., Sahoo, S., Pandit, D., Chalapathi Rao, N.V.Chrome diopside megacryst bearing lamprophyre from the Late Cretaceous Mundwara alkaline complex, NW India: petrological and geodynamic implications.Journal of the Geological Society of India, Vol. 91, pp. 395-399.IndiaAlkaline - Mundwara

Abstract: The occurrence of a rare mantle-derived chrome-diopside megacryst (~8 mm), containing inclusions of olivine, in a lamprophyre dyke from the late Cretaceous polychronous (~100 - 68 Ma) Mundwara alkaline complex of NW India is reported. The olivine inclusions are forsteritic (Fo: 85.23) in composition, and their NiO (0.09 wt%) and CaO (0.13 wt%) contents imply derivation from a peridotitic mantle source. The composition of the chrome diopside (Cr2O3: 0.93 wt ) (Wo45.27 En48.47 Fs5.07 and Ac1.18) megacryst is comparable to that occurring in the garnet peridotite xenoliths found in diamondiferous kimberlites from Archaean cratons. Single pyroxene thermobarometry revealed that this chrome diopside megacryst was derived from a depth range of ~100 km, which is relatively much deeper than that of the chrome-diopside megacrysts (~40-50 km) reported in spinellherzolite xenoliths from the alkali basalts of Deccan age (ca. 66- 67 Ma) from the Kutch, NW India. This study highlights that pre- Deccan lithosphere, below the Mundwara alkaline complex, was at least ~100 km thick and, likely, similar in composition to that of the cratonic lithosphere.
DS201806-1238
2018
Sahoo, S.Pandey, R., Sahoo, S., Pandit, D., Chalapathi Rao, N.V.Recurrent lamprophyre magmatism in the Narmada rift zone: petrographic and mineral chemistry evidence from xenoliths in the Eocene Dongargaon lamprophyre, NW Deccan Large Igneous Province India.Journal of the Indian Institute of Science, 15p. available in pressIndiamagmatism

Abstract: We report rare occurrence of lamprophyre xenoliths within a host lamprophyre from the Dongargaon area, Deccan Large Igneous Province, NW India. The lamprophyre xenoliths are distinct in texture (grain size) as well in mineralogy from those of their host rock. The clinopyroxene (diopside) in the xenoliths is depleted in Ca and Mg but substantially enriched in Fe compared to those in the host lamprophyre. Mica in the xenoliths is a phlogopite whereas that present in the host rock is compositionally a biotite; spinels in the host lamprophyre are relatively enriched in TiO2. As the host lamprophyre dyke has been dated to be of Eocene (ca. 55 Ma) age, the entrained lamprophyre xenoliths are inferred to represent an earlier pulse of lamprophyre emplacement. The recurrent lamprophyre emplacement in this domain is consistent with the recently brought out polychronous nature of Late Cretaceous alkaline magmatism at the Mundwara and Sarnu Dandali complexes in the NW India and is related to the extensional events linked with the reactivation of the Narmada rift zone.
DS201810-2363
2018
Sahoo, S.Pandey, A., Chalapthi Rao, N.V., Chrabarti, R., Sahoo, S.Post collisional calc-alkaline lamprophyres from the Kadiri greenstone belt: evidence for the Neoarchean convergence related evolution of the eastern Dharwar craton and its schist belts.Lithos, doi.10.1016/j.lithos .2018.09.005Indialamprophyres

Abstract: Lamprophyres from the greenstone belts play a crucial role in deciphering tectonic and geodynamic processes operating during the Archean. This study presents a comprehensive mineralogical and geochemical study of three lamprophyre dykes with calc-alkaline to shoshonitic affinities from the Neoarchean Kadiri schist belt, eastern Dharwar craton, southern India. These rocks display porphyritic-panidiomorphic texture, typical of the lamprophyres with amphibole (magnesio-hornblende) as phenocrysts, biotite as microphenocrysts and feldspar, epidote, titanite and apatite confined to the groundmass. Alteration of biotite to chlorite is observed along with mild deformation in the amphibole phenocrysts. Based on mineralogy and major oxide geochemistry, these rocks are classified as the calc-alkaline lamprophyres. Higher Ba/Nb and low Nb/La points to their derivation from an enriched lithospheric mantle source and higher Th/Yb ratio along with negative TNT (Ti-Nb-Ta) and Zr-Hf anomalies on the primitive mantle (PM) normalized multi-element diagram indicates dehydrated fluids from the foundering slab could be the possible metasomatic agent. Fractionated HREE ratios (GdN/YbN >1.9) and higher SmN/YbN suggests that the source region lies in the garnet stability field. Higher than PM Rb/Sr along with positive correlation between K/La and Rb/La reveals presence of metasomatic phlogopite in the source region. Strong negative initial ?Nd along with radiogenic 87Sr/86Sr ratios further support an enriched mantle reservoir involved in their genesis. Non-modal batch melting (1-5%) of a mixed source (phlogopite-garnet peridotite) assuming 5% mixing of subducted sediment with ambient mantle wedge (depleted mantle) satisfies the multi-element concentration pattern shown by the Kadiri lamprophyres. The source enrichment can be linked to the accretion-related growth of Dharwar craton and its schist belts during Neoarchean. Our study shows that a majority of lamprophyres associated with the Archean greenstone belts display a shoshonitic character; this highlights the role of subduction-related processes in the growth and evolution of the greenstone belts .
DS202005-0755
2017
Sahoo, S.Pandey, A., Chalapathi Rao, N.V., Pandit, D., Pankaj, P., Pandey, R., Sahoo, S.Subduction - tectonics in the evolution of the eastern Dharwar craton, southern India: insights from the post-collisional calc-alkaline lamprophyres at the western margin of the Cuddapah Basin.Precambrian Research, in press available, 17p. PdfIndiacraton

Abstract: The geodynamic evolution of the eastern Dharwar craton, southern India, is widely debated with a number of contrasting models ranging from uniformitarian plate convergence to the mantle plume and their combination. We report here the petrology and geochemistry of two undeformed and unmetamorphosed lamprophyre dykes from the Mudigubba area located immediately towards the western margin of the Paleo-Mesoproterozoic Cuddapah basin from this craton. The Mudigubba lamprophyres are free from crustal xenoliths, and have a typical porphyritic-panidiomorphic texture predominated by phenocrysts of amphibole. Clinopyroxene occurs as microphenocrysts with feldspar essentially confined to the groundmass. F-rich apatite and sphene are the other accessories. Mineral chemistry reveals that the amphiboles are of calcic variety (dominantly magnesio-hornblende), the clinopyroxene to be a diopside (Wo45.01-50.40 En36.74-44.58 Fs6.79-12.73 Ac0.42-2.24) and the albitic (Or1.12 Ab91.17 An7.70) nature of the feldspar. The lower abundance of TiO2 in both the amphibole and clinopyroxene, suggest a calc-alkaline nature of the magma. High Mg# (76.8-79.3), Ni (140-240 ppm) and Cr (380-830 ppm) contents along with (i) depletion in U, and Th, (ii) variable Ba/La and (iii) low Nb/La as well as Th/La strikes out possibility of crustal contamination and supports the primary nature of the lamprophyre magma. The presence of significant Nb-Ta, Zr-Hf and Ti negative anomalies in the primitive mantle normalized multi-element plots and their striking similarity with the global calc-alkaline lamprophyres imply the involvement of subduction-related mantle source modification. Various geochemical ratios (e.g., Hf/Sm, Ta/La, Th/Yb, Nb/Yb, La/Nb, Ba/Nb) demonstrate the source enrichment was caused by a fluid-related, rather than silicate-melt related, subduction metasomatism. Binary-mixing calculations assuming average upper crust and N-MORB as the two end members reveals ?10-30% influx of subducted component in the generation of the Mudigubba lamprophyres. A re-examination of the limited geochemical data available for the co-spatial Paleoproterozoic (2200-1600 Ma) alkaline plutons suggests this Neoarchaean subduction-event in this domain could in fact be a regional feature - all along the western margin of the Cuddapah basin and represents a hitherto unrecognised suture zone in the eastern Dharwar craton with the Paleoproterozoic (?) emplacement of Mudigubba lamprophyres post-dating this collisional event. Our findings provide significant geochemical support to the models invoking convergence towards the evolution of the Eastern Dharwar craton and impose important constraints on the geodynamics of the southern peninsular India.
DS202012-2248
2020
Sahoo, S.Sahoo, S., Sreenivasan, B.Response of Earth's magnetic field to large lower mantle heterogeneity.Earth and Planetary Letters, Vol. 550, 116507, 11p. PdfRussia, Canadageophysics - magnetics

Abstract: A simplified two-fold pattern of convection in the Earth's core is often used to explain the non-axisymmetric magnetic flux concentrations in the present day geomagnetic field. For large lateral variations in the lower mantle heat flux, however, a substantial east-west dichotomy in core convection may be expected. This study examines the effect of a large lateral variation in heat flux at the outer boundary in cylindrical annulus experiments that achieve approximate geostrophy of the convection as well as in rapidly rotating spherical shell simulations. In either geometry, the imposed boundary heat flux is derived from the seismic shear wave velocity in the lowermost mantle. The pattern of large-scale convection in the simulations closely follows that in the annulus experiments, which suggests that the lateral buoyancy at the equator essentially determines the structure of core convection. In particular, the location of a coherent downwelling that forms beneath Canada in mildly driven convection entirely switches over to the Siberian region in strongly driven states. Spherical dynamo models in turn show that this eastward migration of convection causes the relative instability or even the disappearance of the high-latitude magnetic flux in the Western hemisphere. Finally, large radial buoyancy causes homogenization of convection, which may place an upper bound for the Rayleigh number in the core.
DS202202-0189
2022
Sahoo, S.Brahma, S., Sahoo, S., Durai, P.R.First report of carbonatite from Gundlupet area, western Dharwar Craton, Karnataka, southern India.Journal of the Geological Society of India, Vol.98, pp. 35-40. Indiacarbonatite

Abstract: A new carbonatite body has been discovered from Gundlupet area, western Dharwar craton, southern India which is located at juncture of major shear zones namely, Kollegal shear zone to the east, Sargur shear zone to the west and Moyar shear zone to the south. The carbonatite and associated syenite have intruded into the peninsular gneissic complex. The southern margin of the syenite has a tectonic contact with the peninsular gneissic complex suggesting their emplacement is related to the splay shear of Moyar shear zone. The Gundlupet carbonatite is dominantly sövite with minor beforsite and iron rich carbonatite which are associated with phenocrystic magnetite, apatite, amphibole, pyroxene and monazite. Fenitisation is observed in local scale along the contact of carbonatite and syenite where metasomatic alterations took place to give rise to alkali amphibole and pyroxene rich rock. Geochemically, the carbonatite is characterised by high CaO content (48.86%-51.80%), P2O5 (0.35%-3.23%) and low SiO2 (3.09%-5.30%). The high Sr (5750-13445 ppm) content and low Ni, Cr, Zn and Cu content indicates that the melt has undergone some degree of fractionation before crystallization. Gundlupet carbonatite is enriched in LREE with values ranging from 5666 ppm to 7530 ppm and average LREE of 6248 ppm.
DS200812-0018
2008
Sahoo, Y.Ali, A., Nakai, S., Bell, K., Sahoo, Y.W isotope study of natrocarbonatites from Oldoinyo Lengai Tanzania.Goldschmidt Conference 2008, Abstract p.A15.Africa, TanzaniaCarbonatite
DS200612-1203
2006
Sahoo, Y.V.Sahoo, Y.V., Nakai, S., Ali, A.Modified ion exchange separation for tungsten isotopic measurements from kimberlite samples using multi-collector inductivity coupled plama mass spectrometry.Analyst, ( Royal Society of Chemistry), Vol. 131, 3, pp. 434-439.TechnologyGeochemistry
DS1998-1275
1998
Sahu, B.K.Sahu, B.K., Reeves, C.V.Continental scale geophysical anomaly patterns: implications for Gondwanare-assembly.Journal of African Earth Sciences, Vol. 27, 1A, p. 165. AbstractGondwanaGeophysics
DS2002-1323
2002
Sahu, B.K.Reeves, C.V., Sahu, B.K., De Wit, M.A re-examination of the paleo position of Africa's eastern neighbours in GondwanaJournal of African Earth Sciences, Vol.34, No.3-4,April-May pp. 101-8.Africa, GondwanaTectonics
DS200412-1646
2004
Sahu, B.K.Reeves, C.V., De Wit, M.J., Sahu, B.K.Tight assembly of Gondwana exposes Phanerozoic shears in Africa as global tectonic players.Gondwana Research, Vol. 7, 1, pp. 7-20.AfricaTectonics
DS201212-0616
2012
Sahu, N.Sahu, N., Gupta, T., Patel, S.C.,Khuntia, D.B.K., Thakur, S.S., Deas, S.K.Petrology of lamproites from the Nuapada lamproite field, Bastar Craton, India.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractIndiaDeposit - Nuapada
DS201312-0771
2013
Sahu, N.Sahu, N., Gupta, T., Patel, S.C.Petrology of lamproites from the Nuapada lamproite field, Bastar craton, India.Proceedings of the 10th. International Kimberlite Conference, Vol. 1, Special Issue of the Journal of the Geological Society of India,, Vol. 1, pp. 137-165.IndiaDeposit - Nuapada
DS2003-1207
2003
Sahu, R.Sahu, R., Kumar, A., Subbarao, K.V., Walsh, J.N., Biswal, T.K.Rb Sr age and Sr isotopic composition of alkaline dykes near Mumbai ( Bombay)Journal of Geological Society of India, Vol. 62, 5, pp. 641-646.IndiaAlkaline rocks
DS200412-1721
2003
Sahu, R.Sahu, R., Kumar, A., Subbarao, K.V., Walsh, J.N., Biswal, T.K.Rb Sr age and Sr isotopic composition of alkaline dykes near Mumbai ( Bombay) further evidence for the Deccan trap Reunion plumeJournal of Geological Society of India, Vol. 62, 5, pp. 641-646.IndiaAlkalic
DS201810-2313
2018
Said, A.Finkelstein, G.J., Jackson, J.M., Said, A., Alatas, A., Leu, B.M., Sturhahn, W., Toellner, T.S.Strongly anisotropic magnesiowustite in Earth's lower mantle. Journal of Geophysical Research Solid Earth, doi.org/10.1029/ 2017JB015349Mantlecore mantle boundary

Abstract: The juxtaposition of a liquid iron?dominant alloy against a mixture of silicate and oxide minerals at Earth's core?mantle boundary is associated with a wide range of complex seismological features. One category of observed structures is ultralow?velocity zones, which are thought to correspond to either aggregates of partially molten material or solid, iron?enriched assemblages. We measured the phonon dispersion relations of (Mg,Fe) O magnesiowüstite containing 76 mol % FeO, a candidate ultralow?velocity zone phase, at high pressures using high?energy resolution inelastic X?ray scattering. From these measurements, we find that magnesiowüstite becomes strongly elastically anisotropic with increasing pressure, potentially contributing to a significant proportion of seismic anisotropy detected near the base of the mantle.
DS1990-1292
1990
Said, R.Said, R.Geology of EgyptBalkema Publishing Co, 734p. $ 85.00 approx. ISBN 90-6191-856-1EgyptBook, Geology
DS1998-1276
1998
Saihkoohi, H.R.Saihkoohi, H.R., West, G.F.3-D seismic imaging of complex structures in glacial depositsGeophysics, Vol. 63, No. 3, May-June pp. 1941-52.OntarioGeomorphology - not specific to diamonds, Shallow environment
DS1998-1277
1998
Saihkoohi, H.R.Saihkoohi, H.R., West, G.F.3-D seismic imaging of complex structures in glacial depositsGeophysics, Vol. 63, No. 3, May-June pp. 1041-52OntarioGeophysics - seismics, Geomorphology - shallow environments
DS200712-0926
2007
Saikia, A.Saikia, A., Frost, D.J., Rubie, D.C.The formation of calcium perovskite from majoritic garnet - implications for splitting of the 520 km seismic discontinuity.Plates, Plumes, and Paradigms, 1p. abstract p. A866.MantleGeophysics - seismics
DS200812-0996
2008
Saikia, A.Saikia, A., Frost, D.J., Rubie, D.C.Splitting of the 520 kilometer seismic discontinuity and chemical heterogeneity in the mantle.Science, Vol. 319, 5869, March 14, pp. 1515-1517.MantleGeophysics - seismics
DS201312-0733
2013
Saikia, D.Ravi Kumar, M., Saikia, D., Singh, A., Srinagesh, D., Baidya, P.R., Dattatrayam, R.S.Low shear velocities in the sublithospheric mantle beneath the Indian shield?Journal of Geophysical Research, 50114IndiaTectonics
DS201510-1764
2015
Saikia, U.Das, R., Saikia, U., Rai, S.S.The deep geology of South India inferred from Moho depth and Vp/Vs ratio.Geophysical Journal International, Vol. 203, pp. 910-926.IndiaGeophysics - seismics

Abstract: We present a comprehensive study of thickness and composition of the crust; and the nature of crust-mantle boundary beneath Southern India using P-wave receiver function from 119 seismic stations. Data from distributed network of seismograph location encompass geological domains like mid to late Archean Dharwar craton, Archean and Proterozoic metamorphic terrains, Proterozoic basin, rifted margins and escarpments, and Deccan volcanics. Except for the mid to lower crust exhumed Archean terrains (of West Dharwar and Southern Granulite) all other geological domains have crustal thickness in the range 33-40 km. In the western Dharwar, crustal thickness increases from ?40 km in the north to over 50 km in the south. The Archean domain of granulite terrain is thicker (40-45 km) and more mafic compared to its counterpart in south deformed at 550 Ma. Most of the crustal blocks have low to moderate Vp/Vs (1.72-1.76) representing a felsic to intermediate composition. Exception to the above include Archean granulite terrain with high Vp/Vs (1.76–1.81) suggestive of more mafic crust beneath them. When accounted for the paleo burial depth of 15-25 km, the study suggests a possible Himalaya-Tibet like scenario beneath the mid-late Archean in southwestern Dharwar and north granulite terrain whose deeper crust has progressively densified. This led to a gradational crust-mantle transition that is otherwise sharp elsewhere. The study suggests a more homogenized and felsic nature of the Precambrian crust beneath the terrains formed after 2.6 Ga, possibly due to delamination of the mafic lower crust. Our study does not suggest any distinction between late Archean and Proterozoic crust. The Deccan volcanism at 65 Ma does not appear to have altered the crustal character beneath it and is similar to the adjoining late Archean east Dharwar craton. The western Ghat escarpment and the coastal plain formed due to separation of India from Madagascar are underlain by mafic lower crust.
DS201904-0776
2019
Saikia, U.Saikia, U., Jumar, V.P., Rai, S.S.Complex upper mantle deformation beneath the Dharwar craton inferred from high density splitting measurements: distinct lateral variation from west to east.Tectonophysics, Vol. 755, pp. 10-20.Indiageophysics - seismics

Abstract: Upper mantle anisotropy investigated using 172 core-refracted (SKS, SKKS) seismic phases along a ~660?km long profile at 10 to 20?km intervals from the west to the east coast of South India reveals significant lateral variations in its magnitude and direction. This profile, with 38 broadband seismic stations, covers mid-Archean Western Dharwar craton (WDC), late-Archean Eastern Dharwar Craton (EDC), Proterozoic Cuddapah Basin (CB) and the passive continental margins along the west and east coast. The observed fast polarization directions (FPDs) show lateral variability: NW50o to NW5o beneath the WDC, NW40o to NE30o beneath the EDC and N5o to N85o beneath the CB and further east. The delay time varies between 0.4 and 2.0?s with an average of 1?s. However, we are unable to fit a two layers anisotropy model for the region due to sparse azimuth coverage. Beneath the WDC, the direction of the fast axis follows trends of shear zones and faults, suggesting “frozen-in” anisotropy in the lithosphere, possibly established during the lithospheric evolution in mid-late Archean. In the EDC, the fast axis does not only follow the plate motion direction but it deviates, manifesting late Archean to Proterozoic deformation may still be present as fossil mantle anisotropy. The splitting trend beneath the CB and Eastern Ghat (EG) follows the strike of the rift along with plate motion direction, indicating anisotropy is influenced by the combination of “frozen” anisotropy due to continental rifting along the eastern margin of Indian plate and active asthenospheric flow.
DS1996-0447
1996
Sailerova, E.Fedikow, M.A.F., Nielsen, E., Sailerova, E.Operation Superior: multimedia geochemical surveys Echimamish, Carrot Rivers, Munro lake greenstone belt.Man. Geological Survey Report Activities, pp. 5-8.ManitobaGeochemistry - exploration
DS200412-0966
2004
Sailhac, P.Keating, P., Sailhac, P.Use of analytic signal to identify magnetic anomalies due to kimberlite pipes.Geophysics, Vol. 69, 1, pp. 180-190.Canada, Ontario, Northwest TerritoriesGeophysics - magnetics, circular, asymmetry
DS200512-0074
2004
Sain, K.Behera, L., Sain, K., Reddy, P.R.Evidence of underplating from seismic and gravity studies in the Mahanadi delta of eastern India and its tectonic significance.Journal of Geophysical Research, Vol. 109, 12, DOI 10.1029/2003 JB002764IndiaTectonics
DS200712-0063
2007
Sain, K.Behara, L., Sain, K.Crustal velocity structure of the Indian shield from deep seismic sounding and receiver function studies.Journal of the Geological Society of India, Vol. 68, 6. pp. 989-992.IndiaGeophysics - seismics
DS200712-0870
2007
Sain, K.Rao, V.V., Sain, K., Prasad, B.R.Dipping Moho in the southern part of Eastern Dharwar Craton, India as revealed by the coincident seismic reflection and refraction study.Current Science, Vol. 93, 3, Aug. 10, pp. 330-336.IndiaGeophysics - seismics
DS200712-0871
2006
Sain, K.Rao, Viljaya, V., Sain, K., Reddy, P.R., Mooney, W.D.Crustal structure and tectonics of the northern part of the southern Granulite Terrane, India.Earth and Planetary Science Letters, Vol. 251, 1-2, Nov. 15, pp.90-103.IndiaTectonics - not specific to diamonds
DS1997-0993
1997
Sainato, C.M.Sainato, C.M., Pomposiello, M.C.Two dimensional magnetotelluric and gravity models of the Tuzgle Volcano Zone Jujuy ProvinceJournal of South American Earth Sciences, Vol. 10, No. 3-4, pp. 247-262ArgentinaGeophysics - magnetics, gravity
DS2002-1382
2002
Saini Eidukat, B.Saini Eidukat, B., Schwert, D.P., Slator, B.M.Geology explorer: virtual geologic mapping and interpretationComputers and Geosciences, Vol. 28, 10, pp.1167-76.GlobalComputers - programs
DS1989-1588
1989
Saini-Eidukat, B.Weiblen, P.W., Saini-Eidukat, B., Miller, J.D.Duluth Complex and associated rocks of the Midcontinent rift systemAmerican Geophysical Union (AGU) 28th. International Geological Congress Field Trip Guidebook, No. T 345, 41pMidcontinentPeridotite/Layered intrusions
DS1991-0177
1991
Saini-Eidukat, B.Brink, S., Saini-Eidukat, B., Earley, D.III, Blake, R.Application of petrographic techniques to assess in situ leaching miningpotentialUnited States Bureau of Mines I.C., No. IC 9295, 14pUnited StatesMining -in-situ, Petrography
DS201706-1061
2017
Sainikova, E.B.Albekov, A.Yu., Chemyshov, N.M., Ryborak, M.V., Kuznetsov, V.S., Sainikova, E.B., Kholin, V.M.U-Pb isotopic age of apatite bearing carbonatites in the Kursk Block, Voronezh crystalline massif ( Central Russia).Doklady Earth Sciences, Vol. 473, 1, pp. 271-272.Russiacarbonatite

Abstract: In the central part of the European part of Russia in the southeastern part of the Kursk tectonic block, some deposits and occurrences of apatite genetically related to the alkaline-carbonatite complex have been revealed. The results of U-Pb analysis of titanite provided the first confident age estimate of silicate-carbonate (phoscorite) rocks in the Dubravin alkaline-ultramafic-carbonatite massif: they formed no later than 2080 ±13 Ma, which indicates their crystallization in the pre-Oskol time during the final stage of the Early Paleoproterozoic (post-Kursk time) stabilization phase of the Kursk block of Sarmatia (about 2.3-2.1 Ga).
DS2002-1383
2002
Saint-Eidukat, B.Saint-Eidukat, B., Schwert, D.P., Slator, B.M.Geology explorer: virtual geologic mapping and interpretationComputers and Geosciences, Vol. 28, 10, Dec. pp. 1167-76.GlobalProgram - role based learning
DS1859-0045
1833
Saint-Hilaire, A. DE.Saint-Hilaire, A. DE.Voyage dans le District des Diamants et sur le Littoral du Bresil.Paris: Gide., 2 VOLS., ( DIAMOND FIELDS Vol. 1, PP. 1-87. )BrazilTravelogue
DS200712-1044
2006
Saintot, A.Stephenson, R.A., Yegorova, T., Brunet, M.F., Stovba, S., Wilson, M., Starostenko, V., Saintot, A., Kusznir, N.Late Paleozoic intra- and pericratonic basins on the East European Craton and its margins.Geological Society of London Memoir, No. 32, pp. 463-480.Europe, Baltic ShieldCraton
DS1910-0431
1914
Saint-Smith, E.C.Saint-Smith, E.C.Geology and Mineral Resources of the Stanthorpe, Ballandean and Wallangarra Districts.Queensland Geological Survey Report For 1913., PP. 132-133.Australia, QueenslandDiamond, Jordan River Gold Field
DS2001-1015
2001
Saisbury, M.H.Saruwatari, K., Ji, S., Long, C., Saisbury, M.H.Seismic anisotropy of mantle xenoliths and constraints on upper mantle structure beneath southern Cordillera.Tectonophysics, Vol. 339, No. 3-4, pp. 403-26.Mantle, British ColumbiaGeophysics - seismics, Xenoliths
DS2003-0624
2003
Saito, A.Ishida, H., Ogasawara, Y., Ohsumi, K., Saito, A.Two stage growth of microdiamond in UHP dolomite marble from Kokechtav MassifJournal of Metamorphic Geology, Vol. 21, 6, pp. 515-22.Russia, KazakhstanMicrodiamonds - morphology
DS200412-0876
2003
Saito, A.Ishida, H., Ogasawara, Y., Ohsumi, K., Saito, A.Two stage growth of microdiamond in UHP dolomite marble from Kokechtav Massif, Kazakhstan.Journal of Metamorphic Geology, Vol. 21, 6, pp. 515-22.Russia, KazakhstanMicrodiamonds - morphology
DS202007-1186
2020
Saito, S.Yoshida, M., Saito, S., Yoshozawa, K.Possible tectonic patterns along the eastern margin of Gondwanaland from numerical studies of mantle convection.Tectonophysics, Vol. 787, 228476, 12p. PdfMantleconvection

Abstract: Two end-member scenarios have been proposed for the tectonic situation along the eastern margins of Gondwanaland before Zealandia was formed ca. 100 million years ago (Ma), namely: (1) A subduction zone located far from the eastern margin of Zealandia, wherein Zealandia may have separated from Gondwanaland by plume push of an active hotspot plume.; (2) A subduction zone located along the eastern margin of Gondwanaland, wherein Zealandia possibly separated from Gondwanaland via trench/subduction retreat. Assuming that the thermal structure of the deep mantle and source of hotspot plumes remained relatively stationary over the last hundred million years, major hotspot plumes with a large buoyancy flux did not exist under Zealandia; the eastern margins of Gondwanaland were far from two large low-shear-velocity provinces under the Africa-Atlantic and South Pacific regions. Herein, through numerical studies of three-dimensional global mantle convection, we examined the mantle convection and surface tectonic patterns at ~100 Ma. The present model considered the real configuration of Gondwanaland at the model surface to observe long-term variations of mantle convection and the resulting surface tectonic conditions. The results demonstrate that the extensive subduction zones developed preferentially along the eastern margin of Gondwanaland when the temperature anomaly of the lower mantle was primarily dominated by high-temperature regions under present-day Africa-Atlantic and South Pacific regions. The results of this study support one of the proposed hypotheses, where the breakup at the eastern margins of Gondwanaland at ~100 Ma occurred via trench/subduction retreat.
DS200712-1063
2007
Saito, T.Takuda, N., Saito, T., Umezawa, H., Okushi, H., Yamasaki, S.The role of boron atoms in heavily boron doped semiconducting homoepitaxial diamond growth - study of surface morphology.Diamond and Related Materials, Vol. 16, 2, Feb., pp. 409-411.TechnologyDiamond morphology
DS200712-1086
2007
Saito, T.Tokuda, N., Saito, T., Umezawa, H., Okushi, H., Yamasaki, S.The role of boron atoms in heavily boron-doped semiconducting homoepitaxial diamond growth. Study of surface morphology.Diamond and Related Materials, Vol. 16, 2, pp. 409-411. Ingenta 1070685096TechnologyDiamond morphology
DS1990-1293
1990
Saito, Y.Saito, Y., Sato, K., Gomi, K., Miyadera, H.Diamond synthesis from CO-H2 mixed gas plasmaJournal of Material Science, Vol. 25, No. 28, February pp. 1246-1250GlobalDiamond synthesis, Gas plasma
DS201607-1286
2016
Saiz, G.Bird, M.I., Wynn, J.G., Saiz, G., Wurster, C.W., McBeath, A.The pyrogenic carbon cycle.Annual Review of Earth and Planetary Sciences, Vol. 43, pp. 273-298.MantleCarbon

Abstract: Pyrogenic carbon (PyC; includes soot, char, black carbon, and biochar) is produced by the incomplete combustion of organic matter accompanying biomass burning and fossil fuel consumption. PyC is pervasive in the environment, distributed throughout the atmosphere as well as soils, sediments, and water in both the marine and terrestrial environment. The physicochemical characteristics of PyC are complex and highly variable, dependent on the organic precursor and the conditions of formation. A component of PyC is highly recalcitrant and persists in the environment for millennia. However, it is now clear that a significant proportion of PyC undergoes transformation, translocation, and remineralization by a range of biotic and abiotic processes on comparatively short timescales. Here we synthesize current knowledge of the production, stocks, and fluxes of PyC as well as the physical and chemical processes through which it interacts as a dynamic component of the global carbon cycle.
DS200412-1722
2004
Sajeev, K.Sajeev, K., Osani, Y., Santosh, M.Ultrahigh temperature metamorphism followed by two stage decompression of garnet orthopyroxene sillimanite granulites from GanguContributions to Mineralogy and Petrology, Vol. 148, 1, pp. 29-46.IndiaUHP
DS200612-1204
2006
Sajeev, K.Sajeev, K., Santosh, M.Extreme crustal metamorphism and crust mantle processes: an introduction.Lithos, in press availableMantleMetamorphism
DS200612-1222
2006
Sajeev, K.Santosh, M., Sajeev, K., Li, J.H.Extreme crustal metamorphism during Columbia supercontinent assembly: evidence from North Chin a Craton.Gondwana Research, Vol. 10, 3-4, pp. 256-266.ChinaMetamorphism
DS201212-0617
2012
Sajeev, K.Sajeev, K., Windley, B.F., Hegner, E., Komiya, T.High temperature, high pressure granulites ( retrogressed eclogites) in the central region of the Lewisian NW Scotland: crustal scale subduction in the Neoarchean.Gondwana Research, in pressEurope, ScotlandEclogite
DS201412-0725
2014
Sajeev, K.Ratheesh-Kumar, R.T., Windley, B.F., Sajeev, K.Tectonic inheritance of the Indian shield: new insights from its elastic thickness structure.Tectonophysics, Vol. 615-616, pp. 40-52.IndiaTectonics
DS201509-0423
2014
Sajeev, K.Ratheesh-Kumar, R.T., Ishwar-Kumar, C., Windley, B., Razakamanana, T., Nair, R.R., Sajeev, K.India-Madagascar paleo-fit based on flexural isostasy of their rifted margins.Gondwana Research, Vol. 28, 2, pp. 581-600.India, Africa, MadagascarTectonics

Abstract: The present study contributes new constraints on, and definitions of, the reconstructed plate margins of India and Madagascar based on flexural isostasy along the Western Continental Margin of India (WCMI) and the Eastern Continental Margin of Madagascar (ECMM). We have estimated the nature of isostasy and crustal geometry along the two margins, and have examined their possible conjugate structure. Here we utilize elastic thickness (Te) and Moho depth data as the primary basis for the correlation of these passive margins. We employ the flexure inversion technique that operates in spatial domain in order to estimate the spatial variation of effective elastic thickness. Gravity inversion and flexure inversion techniques are used to estimate the configuration of the Moho/Crust-Mantle Interface that reveals regional correlations with the elastic thickness variations. These results correlate well with the continental and oceanic segments of the Indian and African plates. The present study has found a linear zone of anomalously low-Te (1-5 km) along the WCMI (~1680 km), which correlates well with the low-Te patterns obtained all along the ECMM. We suggest that the low-Te zones along the WCMI and ECMM represent paleo-rift inception points of lithosphere thermally and mechanically weakened by the combined effects of the Marion hotspot and lithospheric extension due to rifting. We have produced an India-Madagascar paleo-fit representing the initial phase of separation based on the Te estimates of the rifted conjugate margins, which is confirmed by a close-fit correlation of Moho geometry and bathymetry of the shelf margins. The matching of tectonic lineaments, lithologies and geochronological belts between India and Madagascar provide an additional support for the present plate reconstruction.
DS201610-1873
2016
Sajeev, K.Ishwar-Kumar, C., Santosh, M., Wilde, S.A., Tsunogae, T., Itaya, T., Windley, B., Sajeev, K.Mesoproterozoic suturing of Archean crustal blocks in western peninsula India: implications for India-Madagascar correlations.Lithos, Vol. 263, pp. 143-160.IndiaGeodynamics

Abstract: The Kumta and Mercara suture zones welding together Archean crustal blocks in western peninsular India offer critical insights into Precambrian continental juxtapositions and the crustal evolution of eastern Gondwana. Here we present the results from an integrated study of the structure, geology, petrology, mineral chemistry, metamorphic P-T conditions, zircon U-Pb ages and Lu-Hf isotopes of metasedimentary rocks from the two sutures. The dominant rocks in the Kumta suture are greenschist- to amphibolite-facies quartz-phengite schist, garnet-biotite schist, chlorite schist, fuchsite schist and marble. The textural relations, mineral chemistry and thermodynamic modelling of garnet-biotite schist from the Kumta suture indicate peak metamorphic P-T conditions of ca. 11 kbar at 790 °C, with detrital SHRIMP U-Pb zircon ages ranging from 3420 to 2547 Ma, ?Hf (t) values from ? 9.2 to 5.6, and TDMc model ages from 3747 to 2792 Ma. The K-Ar age of phengite from quartz-phengite schist is ca. 1326 Ma and that of biotite from garnet-biotite schist is ca. 1385 Ma, which are interpreted to broadly constrain the timing of metamorphism related to the suturing event. The Mercara suture contains amphibolite- to granulite-facies mylonitic quartzo-feldspathic gneiss, garnet-kyanite-sillimanite gneiss, garnet-biotite-kyanite-gedrite-cordierite gneiss, garnet-biotite-hornblende gneiss, calc-silicate granulite and metagabbro. The textural relations, mineral chemistry and thermodynamic modelling of garnet-biotite-kyanite-gedrite-cordierite gneiss from the Mercara suture indicate peak metamorphic P-T conditions of ca. 13 kbar at 825 °C, followed by isothermal decompression and cooling. For pelitic gneisses from the Mercara suture, LA-ICP-MS U-Pb zircon ages vary from 3249 to 3045 Ma, ?Hf (t) values range from ? 18.9 to 4.2, and TDMc model ages vary from 4094 to 3314 Ma. The lower intercept age of detrital zircons in the pelitic gneisses from the Mercara suture ranges from 1464 to 1106 Ma, indicating the approximate timing of a major lead-loss event, possibly corresponding to metamorphism, and is broadly coeval with events in the Kumta suture. Synthesis of the above results indicates that the Kumta and Mercara suture zones incorporated sediments from Palaeoarchean to Mesoproterozoic sources and underwent high-pressure metamorphism in the late Mesoproterozoic. The protolith sediments were derived from regions containing juvenile Palaeoarchean crust, together with detritus from the recycling of older continental crust. Integration of the above results with published data suggests that the Mesoproterozoic (1460-1100 Ma) Kumta and Mercara suture zones separate the Archean (3400-2500 Ma) Karwar-Coorg block and Dharwar Craton in western peninsular India. Based on regional structural and other geological data we interpret the Kumta and Mercara suture zones as extensions of the Betsimisaraka suture of eastern Madagascar into western India.
DS201907-1553
2019
Saka, S.Jing, J-J., Su, B-X., Xiao, Y., Zhang, H-F., Uysal, I., Chen, C., Lin, W., Chu, Y., Saka, S.Reactive origin of mantle harzburgite: evidence from orthopyroxene-spinel association.Lithos, Vol. 342-343, pp. 175-186.Europe, Turkeymelting

Abstract: Harzburgites with high modal orthopyroxene (generally >23?vol%) in Archean craton, mantle wedge and oceanic lithospheric mantle are considered to be produced by the interaction between Si-rich liquids and rocks. However, the absence of samples from continental margin hinders the recognition whether this process is prevalent. Mantle xenoliths entrained in Miocene basalts from the Thrace Basin, the margin of Eurasian continent, are dominated by harzburgites with anomalously high orthopyroxene modes. These orthopyroxene grains closely associate with spinel and occasionally with clinopyroxene. In these orthopyroxene-spinel associations, orthopyroxene grains can be up to 1?cm in diameter and display high Al2O3 contents (1.41-4.61?wt%) and Mg# values (89.6-92.4), while spinel crystals are anhedral and bud-shaped and are commonly foliated, with a wide variation in Cr# values ranging from 7.8 to 52.7. The Fe2+/Fe3+ vs. TiO2 diagram shows lots of these spinels are “magmatic” (i.e. spinel crystallized from melts). The orthopyroxene grains have LREE diverging from the modelled melting trends, indicating possible metasomatism following partial melting. They are present in elongated shape, cutting across olivine grains and also replacing olivine as surrounding rims. Fine-grained olivine is occasionally enclosed in the orthopyroxene-spinel association. We, therefore, propose that the association of orthopyroxene and spinel developed from the melt/fluid-rock interaction. These features indicate mineral phase transformation from olivine to orthopyroxene, which can be expressed by the equation: ‘Mg2SiO4 (Ol)?+?SiO2?=?Mg2Si2O6 (Opx)’. The observed Al-rich rim of spinel and bud-shaped Al-spinel, suggest sufficient amount of Al in the Si-rich liquids. The mechanism involved here is the consumption of olivine to produce orthopyroxene and spinel as in the equation: ‘Mg2SiO4 (Ol)?+?Al2O3?=?MgSiO3 (Opx)?+?MgAl2O4 (Sp)’. The Si and Al were enriched in the percolating liquids. Both the high-Cr# and low-Cr# spinels with ‘magmatic’ features imply the percolating liquids were multi-staged or inhomogeneous Cr contents in the liquids. This melt/fluid-rock interaction may account for the formation of abundant harzburgites with high orthopyroxene modes in the Eurasian continental margin. Thus, it indicates the reacting harzburgites are prevalent in the lithospheric mantle beneath oceanic crust, Archean craton and mantle wedge, as well as in the continental margin.
DS201909-2051
2019
Saka, S.Jing, J-J., Su, B-X., Xiao, Y., Zhang, H-F., Uysal, I., Chen, C., Lin, W., Chu, Y., Saka, S.Reactive origin of mantle harzburgite: evidence from orthopyroxene-spinel association.Lithos, Vol. 342-343, pp. 175-186.Mantleharzburgite

Abstract: Harzburgites with high modal orthopyroxene (generally >23?vol%) in Archean craton, mantle wedge and oceanic lithospheric mantle are considered to be produced by the interaction between Si-rich liquids and rocks. However, the absence of samples from continental margin hinders the recognition whether this process is prevalent. Mantle xenoliths entrained in Miocene basalts from the Thrace Basin, the margin of Eurasian continent, are dominated by harzburgites with anomalously high orthopyroxene modes. These orthopyroxene grains closely associate with spinel and occasionally with clinopyroxene. In these orthopyroxene-spinel associations, orthopyroxene grains can be up to 1?cm in diameter and display high Al2O3 contents (1.41-4.61?wt%) and Mg# values (89.6-92.4), while spinel crystals are anhedral and bud-shaped and are commonly foliated, with a wide variation in Cr# values ranging from 7.8 to 52.7. The Fe2+/Fe3+ vs. TiO2 diagram shows lots of these spinels are “magmatic” (i.e. spinel crystallized from melts). The orthopyroxene grains have LREE diverging from the modelled melting trends, indicating possible metasomatism following partial melting. They are present in elongated shape, cutting across olivine grains and also replacing olivine as surrounding rims. Fine-grained olivine is occasionally enclosed in the orthopyroxene-spinel association. We, therefore, propose that the association of orthopyroxene and spinel developed from the melt/fluid-rock interaction. These features indicate mineral phase transformation from olivine to orthopyroxene, which can be expressed by the equation: ‘Mg2SiO4 (Ol)?+?SiO2?=?Mg2Si2O6 (Opx)’. The observed Al-rich rim of spinel and bud-shaped Al-spinel, suggest sufficient amount of Al in the Si-rich liquids. The mechanism involved here is the consumption of olivine to produce orthopyroxene and spinel as in the equation: ‘Mg2SiO4 (Ol)?+?Al2O3?=?MgSiO3 (Opx)?+?MgAl2O4 (Sp)’. The Si and Al were enriched in the percolating liquids. Both the high-Cr# and low-Cr# spinels with ‘magmatic’ features imply the percolating liquids were multi-staged or inhomogeneous Cr contents in the liquids. This melt/fluid-rock interaction may account for the formation of abundant harzburgites with high orthopyroxene modes in the Eurasian continental margin. Thus, it indicates the reacting harzburgites are prevalent in the lithospheric mantle beneath oceanic crust, Archean craton and mantle wedge, as well as in the continental margin.
DS201012-0213
2010
SakaiFrost, D.F., Asahara, Y., Rubie, D.C., Miyajima, N., Dubrovinsky, Holzapfel, Ohtani, Miyahara, SakaiPartitioning of oxygen between the Earth's mantle and core.Journal of Geophysical Research, Vol. 115, B2 , B02202.MantleChemistry
DS200812-0712
2008
Sakai, S.Manthilake, M.A.G.M., Sawada, Y., Sakai, S.Genesis and evolution of Eppawala carbonatites, Sri Lanka.Journal of Asian Earth Sciences, Vol. 32, 1,feb. 15, pp. 66-75.Asia, Sri LankaCarbonatite
DS200612-1205
2006
Sakai, T.Sakai, T., Kondo, T., Ohtain, E., Terasaki, H., Endo, N., Kuba, T., Suzuki, T., Kikegawa, T.Interaction between iron and post perovskite at core mantle boundary and core signature in plume source region.Geophysical Research Letters, Vol. 33, 15, August 16, L15317MantleGeophysics - seismics, boundary
DS200612-1206
2006
Sakai, T.Sakai, T., Kondo, T., Ohtani, E., Terasaki, H., Miyahara, Yoo, Endo, Kuba, Suzuki, KikegawaWetting property at the core mantle boundary and core signature in plume source region.International Mineralogical Association 19th. General Meeting, held Kobe, Japan July 23-28 2006, Abstract p. 129.MantleGeophysics - seismics
DS201012-0014
2009
Sakai, T.Asanuma, H., Ohtani, E., Sakai, T., Terasaki, H., Kamada, S., Kondo, T., Kikegawa, T.Melting of iron silicon alloy up to the core mantle boundary pressure: implications to the thermal structure of the Earth's core.Physics and Chemistry of Minerals, Vol. 37, 6, pp. 353-359.MantleMelting
DS201412-0645
2014
Sakai, T.Ohira, I., Ohtani, E., Sakai, T., Miyahara, M., Hirao, N., Ohishi, Y., Nishijima, M.Stability of a hydrous delta phase AlOOH-MgSiO2(OH)2, and a mechanism for water transport into the base of lower mantle.Earth and Planetary Science Letters, Vol. 401, pp. 12-17.MantleWater
DS201811-2597
2018
Sakai, T.Ohuchi, T., Lei, X., Higo, Y., Tange, Y., Sakai, T., Fujino, K.Semi-brittle behavior of wet olivine aggregates: the role of aqueous fluid in faulting at upper mantle pressures.Contributions to Mineralogy and Petrology, Vol. 173, 21p. Doi.org/10.1007/s00410-018-1515-9Mantlesubduction

Abstract: The role of aqueous fluid in fracturing in subducting slabs was investigated through a series of deformation experiments on dunite that was undersaturated (i.e., fluid-free) or saturated with water (i.e., aqueous-fluid bearing) at pressures of 1.0-1.8 GPa and temperatures of 670-1250 K, corresponding to the conditions of the shallower regions of the double seismic zone in slabs. In situ X-ray diffraction, radiography, and acoustic emissions (AEs) monitoring demonstrated that semi-brittle flow associated with AEs was dominant and the creep/failure strength of dunite was insensitive to the dissolved water content in olivine. In contrast, aqueous fluid drastically decreased the creep/failure strength of dunite (up to ~ 1 GPa of weakening) over a wide range of temperatures in the semi-brittle regime. Weakening of the dunite by the aqueous fluid resulted in the reduction of the number of AE events (i.e., suppression of microcracking) and shortening of time to failure. The AE hypocenters were located at the margin of the deforming sample while the interior of the faulted sample was aseismic (i.e., aseismic semi-brittle flow) under water-saturated conditions. A faulting (slip rate of ~ 10?³ to 10?? s?¹) associated with a large drop of stress (?? ~ 0.5 to 1 GPa) and/or pressure (?P ~ 0.5 GPa) was dominant in fluid-free dunite, while a slow faulting (slip rate < 8 × 10?? s?¹) without any stress/pressure drop was common in water-saturated dunite. Aseismic semi-brittle flow may mimic silent ductile flow under water-saturated conditions in subducting slabs.
DS201312-0772
2014
Sakamaki, K.Sakamaki, K., Ogasawara, Y.Hydroxyl in clinopyroxene and titanite in a UHP diamond free garnet clinopyroxene rock from the Kokchetav Massif, northern Kazakhstan.International Geology Review, Vol. 56, 2, pp. 133-149.Russia, KazakhstanDeposit - Kokchetav
DS201412-0770
2014
Sakamaki, K.Sakamaki, K., Ogasawara, Y.Hydroxyl in clinopyroxene and titanite in a UHP diamond-free-garnet-clinopyroxene rock from the Kokchetav Massif, northern Kazakhstan.International Geology Review, Vol. 56, 2, pp. 133-149.Russia, KazakhstanKokchetav massif
DS201603-0406
2015
Sakamaki, K.Ogasawara Y., Shimizu, R., Sakamaki, K.Diversity of the Kokchetav metamorphic diamonds and their formation related to h ( sub 2) o-rich fluid conditions.Geological Society of America Annual Meeting, Vol. 47, 7, p. 169. abstractRussiaMetamorphic diamonds

Abstract: The metamorphic diamonds in the Kokchetav Massif show very diverse features in morphologies and grain sizes with other crystal characters, Raman spectra (FWHM, PL), cathodoluminescence spectra, C isotope, abundance, paragenesis with silicates and carbonates. The formations of these diamonds, however, seem to be related to H2O-fluid conditions.?Dolomite marble has the highest abundance in diamond. The diamond grew at two stages and 2nd stage growth was from H2O fluid. Grt-Bt gneiss is 2nd highest and the diamond shows several morphologies; however, no 2nd stage growth. In dolomite marble, diamond at 2nd stage has light carbon isotope, -17 to -27 whereas 1st stage diamond has -8 to -15. The light carbon of 2nd stage could be organic carbon in gneisses carried by H2O-fluid; dissolution of diamond in gneisses could have occurred. No 2nd stage growth in gneisses supports this idea. Carbon-bearing H2O fluid infiltration into dolomite marble caused the change of carbon solubility in fluid to precipitate abundant fine diamonds (10-20 mm), quickly. Recently discovered sp2 graphitic carbon inclusions in 2nd stage diamond (AGU2014F V13B-4771), which is a relic of metastable intermediate phase for diamond formation, suggest the diamond participation from H2O fluid. A minor amount of diamond (large-grained, ca. 150 µm at average) occurs in Grt-Cpx rock. Recently, we found the overgrowth of large-grained cubic diamond on small-grained one by multi-layered 2D Raman mappings (JpGU2014 No.02541). This indicates slow-growth in H2O-fluid having low oversaturation degree of carbon. UHP calcite marble contains a trace amount of small-grained diamond (no 2nd stage growth) only in diopside; titanite with coesite exsolution does not contain diamond. These suggest that very high H2O activity for titanite stability makes diamond unstable, and dissolution of diamond was possible. This is a similar relation with UHP dolomitic marble, which Arg-Fo and Arg-Ti-Chum were stable but diamond was unstable. In Tur-Fel-Qtz rock, diamond is included in new mineral "maruyamaite" (K-rich Tur); recent experiments show high-P and fluid-bearing conditions for maruyamaite. Summarizing these diverse features of the Kokchetav diamonds, those formation and their possible dissolutions have strong relationships with H2O-fluid conditions.
DS201608-1436
2016
Sakamaki, K.Sakamaki, K., Sato, Y., Ogasawara, Y.Hydrous Na-garnet from Garnet Ridge products of mantle metasomatism underneath the Colorado Plateau.Progress in Earth and Planetary Science, Vol. 3, 20, 17p.United States, Colorado PlateauMetasomatism

Abstract: This is the first report on amphibole exsolution in pyrope from the Colorado Plateau. Pyrope crystals delivered from mantle depths underneath the Colorado Plateau by kimberlitic volcanism at 30 Ma were collected at Garnet Ridge, northern Arizona. The garnet grains analyzed in this study occur as discrete crystals (without adjacent rock matrix) and are classified into two major groups, Cr-rich pyrope and Cr-poor pyrope. The Cr-poor pyrope group is divided into four subgroups based on exsolved phases: amphibole lamella type, ilmenite lamella type, dense lamellae type, and clinopyroxene/amphibole lamellae type. Exsolved amphibole occurs in amphibole lamella type, dense lamellae type, and clinopyroxene/amphibole lamellae type of Cr-poor pyrope. The amphibole crystals tend to have preferred orientations in their garnet hosts and occur as monomineralic hexagonal or rhombic prisms and tablets, and as multimineralic needles or blades with other exsolved phases. Exsolved amphibole has pargasitic compositions (Na2O up to 1.6 apfu based on 23 oxygen). Garnet host crystals that have undergone amphibole exsolution have low OH contents (2-42 ppmw H2O) compared to garnets that do not have amphibole lamellae (up to 115 ppmw H2O). The low OH contents of garnets hosting amphibole lamellae suggest loss of OH from garnet during amphibole exsolution. Amphibole exsolution from pyrope resulted from breakdown of a precursor “hydrous Na-garnet” composition (Mg,Na+ x)3(Al2???x, Mgx)2Si3O12???2x(OH)2x. Exsolution of amphibole and other phases probably occurred during exhumation to depths shallower than 100 km prior to volcanic eruption. Based on the abundance and composition of exsolved clinopyroxene and amphibole lamellae in one garnet, hydrous Na-garnet had excess silicon (Si3.017 apfu, 12 oxygen normalization, vs. X3Y2Si3O12 for typical garnet). Comparison with experimental data suggests crystallization at pressures near 6-8 GPa. Garnet crystals that host exsolved amphibole have compositions (Pyp49-76, 3-10 wt% CaO, and up to 0.6 wt% Cr2O3) similar to garnets reported from pyroxenites, and have pyrope-almandine-grossular compositional ranges that overlap with the Cr-rich pyrope (typical lherzolitic garnet). Hydrous Na-garnet was likely formed by metasomatic reactions between Cr-rich pyrope and Na-rich aqueous fluid in the deep upper mantle. The most likely source of metasomatic Na-rich fluid is ancient oceanic crust that was subducted before subduction of the Farallon Plate beneath the Colorado Plateau.
DS200612-1207
2006
Sakamaki, T.Sakamaki, T., Suzuki, A., Ohtani, E.Stability of hydrous melt at the base of the Earth's upper mantle.Nature, No. 7073, Jan. 12, pp. 192-194.MantleMelting
DS200812-0406
2007
Sakamaki, T.Ghosh, S., Ohtani, E., Litasov, K., Suzuki, A., Sakamaki, T.Stability of carbonated magmas at the base of the Earth's upper mantle.Geophysical Research Letters, Vol. 34, 22, pp. L22312.MantlePetrology
DS201012-0651
2009
Sakamaki, T.Sakamaki, T., Ohtani, E., Urakawa, S., Suzuki, A., Katayama, Y.Density of dry peridotite magma at high pressure using an x-ray absorption method.American Mineralogist, Vol. 95, pp. 144-147.TechnologyUHP
DS201112-0901
2011
Sakamaki, T.Sakamaki, T., Ohtani, E., Urakawa, S., Terasaki, H., Katayama, Y.Density of carbonated peridotite magma at high pressure using an X-ray absorption method.American Mineralogist, Vol. 96, pp. 553-557.MantleHP
DS201412-0542
2014
Sakamaki, T.Maeda, F., Ohtani, E., Kamada, S., Sakamaki, T., Ohishi, Y., Hirao, N.The reactions in the MgCO3-SiO2 system in the slabs subducted into the lower mantle and formation of deep diamond.V.S. Sobolev Institute of Geology and Mineralogy Siberian Branch Russian Academy of Sciences International Symposium Advances in high pressure research: breaking scales and horizons ( Courtesy of N. Poikilenko), Held Sept. 22-26, 1p. AbstractSouth America, BrazilCarbon
DS201412-0771
2013
Sakamaki, T.Sakamaki, T., Suzuki, A., Ohtani, E., Terasaki, H., Urakawa, S.Ponded melt at the boundary between the lithosphere and asthenosphere.Nature Geoscience, Vol. 6, no. 12, pp. 1041-1044.MantleMagmatism - ponding
DS201503-0164
2015
Sakamaki, T.Ohtani, E., Amaike, Y., Kamada, S., Sakamaki, T., Hirao, N.Stability of hydrous phase H MgSi04H2 under lower mantle conditions.Geophysical Research Letters, Vol. 41, 23, pp. 8283-8287.MantleMineralogy
DS201704-0638
2017
Sakamaki, T.Maeda, F., Ohtani, E., Kamada, S., Sakamaki, T., Hirao, N., Ohishi, Y.Diamond formation in the deep lower mantle: a high pressure reaction of MgCO3 and SiO2.Nature Scientific reports, Jan. 13, 7p. PdfMantleDiamond, genesis

Abstract: Diamond is an evidence for carbon existing in the deep Earth. Some diamonds are considered to have originated at various depth ranges from the mantle transition zone to the lower mantle. These diamonds are expected to carry significant information about the deep Earth. Here, we determined the phase relations in the MgCO3-SiO2 system up to 152?GPa and 3,100?K using a double sided laser-heated diamond anvil cell combined with in situ synchrotron X-ray diffraction. MgCO3 transforms from magnesite to the high-pressure polymorph of MgCO3, phase II, above 80?GPa. A reaction between MgCO3 phase II and SiO2 (CaCl2-type SiO2 or seifertite) to form diamond and MgSiO3 (bridgmanite or post-perovsktite) was identified in the deep lower mantle conditions. These observations suggested that the reaction of the MgCO3 phase II with SiO2 causes formation of super-deep diamond in cold slabs descending into the deep lower mantle.
DS202007-1182
2020
Sakamaki, T.Tanaka, R., Sakamaki, T., Ohtani, E., Fukui, H., Kamada, S., Suzuki, A., Tsutsui, S., Uchiyama, H., Baron, A.Q.R.The sound velocity of wustite at high pressures: implications for low-velocity anomalies at the base of the lower mantle.Progress in Earth and Planetary Science, Vol. 7, 23, 7p. PdfMantlewustite

Abstract: The longitudinal sound velocity (VP) and the density (?) of wüstite, FeO, were measured at pressures of up to 112.3?GPa and temperatures of up to 1700?K using both inelastic X-ray scattering and X-ray diffraction combined with a laser-heated diamond-anvil cell. The linear relationship between VP and ?, Birch’s law, for wüstite can be expressed as VP = 1.55 (1) × ? [g/cm3] ? 2.03 (8) [km/s] at 300?K and VP = 1.61 (1) × ? [kg/m3] ? 2.82 (10) [km/s] at 1700?K. The sound velocity of wüstite is significantly lower than that of bridgmanite and ferropericlase under lower mantle conditions. In other words, the existence of wüstite in the lower mantle can efficiently decrease the seismic velocity. Considering its slow velocity and several mechanisms for the formation of FeO-rich regions at the core-mantle boundary, we confirm earlier suggestions indicating that wüstite enrichment at the bottom of the Earth’s mantle may contribute to the formation of denser ultra-low velocity zones.
DS1993-1369
1993
Sakamoto, M.Sakamoto, M., Shiono, K., Masumoto, S., Wadatsumi, K.A computerized geologic mapping system based on logical models of geologicstructuresNonrenewable Resources, Vol. 2, No. 2, Summer pp. 140-147GlobalComputer, Program -CIGMA.
DS202106-0973
2021
Sakamoto, N.Tagawa, S., Sakamoto, N., Hirose, K., Hernlund, J., Ohishi, Y., Yurimoto, H.Experimental evidence for more hydrogen in Earth's core than in the oceans.Nature Communications, doi.org/10.1038/s41467-021-22035-0 Vol. 12 8p. PdfMantlehydrogen

Abstract: Hydrogen is one of the possible alloying elements in the Earth’s core, but its siderophile (iron-loving) nature is debated. Here we experimentally examined the partitioning of hydrogen between molten iron and silicate melt at 30-60 gigapascals and 3100-4600?kelvin. We find that hydrogen has a metal/silicate partition coefficient DH???29 and is therefore strongly siderophile at conditions of core formation. Unless water was delivered only in the final stage of accretion, core formation scenarios suggest that 0.3-0.6?wt% H was incorporated into the core, leaving a relatively small residual H2O concentration in silicates. This amount of H explains 30-60% of the density deficit and sound velocity excess of the outer core relative to pure iron. Our results also suggest that hydrogen may be an important constituent in the metallic cores of any terrestrial planet or moon having a mass in excess of ~10% of the Earth.
DS2003-0621
2003
Sakamoto, S.Irifune, T., Kurio, A., Sakamoto, S., Inoue, T., Suiniya, H.Ultrahard polycrystalline diamond from graphite. CorrectionNature, No. 6923, Feb. 6, p. 599. also No. 6925, p. 806 Feb 20GlobalDiamond synthesis
DS200412-0873
2004
Sakamoto, S.Irifune, T., Kuiro, A., Sakamoto, S., Inoue, T., Sumiya, H., Funakoshi, K.Formation of pure polycrystalline diamond by direct conversion of graphite at high pressure and high temperature.Physics of the Earth and Planetary Interiors, Vol. 143-144, pp. 593-600.TechnologyUHP - mineralogy
DS201907-1533
2019
Sakantsev, G.G.Cheskidov, V.I., Akishev, A.N., Sakantsev, G.G.Use of draglines in mining diamond ore deposits in Yakutia.Journal of Mining Science, Vol. 54, 4, pp. 628-637.Russia, Yakutiamining

Abstract: Potential ranges of use of draglines at steeply dipping diamond ore deposits in Yakutia are discussed. Technology of stripping with direct dumping and rehandling by draglines is substantiated for upper overburden layers. A variant of increasing height of stripping benches on haulage horizons through the use of draglines and crane lines is discussed. A resource saving technology is proposed for mining roundish and extended ore bodies with alternating advance of mining front and with internal dumping. The method of estimating efficient thickness of overburden in case of direct dumping is developed using the layer coefficient of overburden rehandling. Expediency of using blasting for displacement of broken overburden to internal dump is specified.
DS200612-1208
2006
Sakar, R.K.Sakar, R.K., Saha, D.K.A note on the lithosphere thickness and heat flow density of the Indian Craton from MAGSAT data.Acta Geophysica, Vol. 54, 2, June pp. 198-204.IndiaGeothermometry
DS200512-0928
2005
Sakaran, A.V.Sakaran, A.V.Galactic encounters and ice ages in the Earth's history.Current Science, Vol.89, 3, August 10, pp. 439-440.Glaciology, geomorphology, snowball Earth
DS200812-0471
2008
Sakari, T.Hirao, N., Ohtani, E., Kondo, T., Sakari, T., Kikegawa, T.Hollandite II phase in KAiSi3O8 as a potential host mineral of potassium in the Earth's lower mantle.Physics of the Earth and Planetary Interiors., Vol. 166, 1-2, pp. 97-104.MantlePotassium
DS200412-0881
2003
Sakata, M.Isshiki, E., Irifune, T., Hiropse, K., Ono, S., Ohishi, Y., Watanuki, T., Nishibori, E., Takat, M., Sakata, M.Stability of magnesite and its high pressure form in the lowermost mantle.Nature, No. 6969, pp. 60-62.MantleUHP
DS1987-0077
1987
Sakhno, B.E.Bratus, M.D., Tatarini, V.I., Sakhno, B.E.Composition of fluid inclusions in the quenched particles from the explosive ring like structures and kimberlite pipes.(Russian)Geochemistry International (Geokhimiya), (Russian), No. 11, November pp. 1563-1568RussiaBlank
DS1996-1246
1996
Sakhno, V.G.Sakhno, V.G., Maximov, S.O.Lamproite volcanism of the activized cratons of the Russia Far EastInternational Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 395.RussiaLamproites
DS2001-1003
2001
Sakhno, V.G.Sakhno, V.G., Matyunin, A.P., Moiseenko, V.G.Isotopic signatures of kimberlites in the Kurkhan Diamondiferous diatreme, Primore region.Doklady Academy of Sciences, Vol. 380, No. 7, Sept-Oct. pp.833-6.RussiaGeochronology
DS2002-1384
2002
Sakhno, V.G.Sakhno, V.G., Moiseenko, V.G.Plume volcanism of East Asia craton11th. Quadrennial Iagod Symposium And Geocongress 2002 Held Windhoek, Abstract p. 39.AsiaLamproites, kamafugites
DS2002-1385
2002
Sakhno, V.G.Sakhno, V.G., Moiseenko, V.G.High K mafic rocks of the northern Omolon CratonDoklady Earth Sciences, Vol. 387, 8, pp. 899=903.RussiaPotassic rocks, alkaline
DS2002-1386
2002
Sakhno, V.G.Sakhno, V.G., Moiseenko, V.G., Zhuravlev, D.Z., Matyunin, A.P.Sm Nd ages of Diamondiferous kimberlites of the Kurkhan diatreme in the Khanka Massif, Primor'e region.Doklady Earth Sciences, Vol. 387A, 9, pp. 1110-1112.RussiaGeochronology
DS2002-1387
2002
Sakhno, V.G.Sakhno, V.G., Moiseenko, V.G., Zhuravlev, D.Z., Matyunin, A.P.Sm Nd age of Diamondiferous kimberlites of the Kurkhan diatreme in the Khanka Massif Primore region.Geochemistry International, Vol. 40, 12, pp. 110-2.RussiaGeochronology
DS200412-1251
2004
Sakhno, V.G.Maximov, S.O., Sakhno, V.G.High K picrites and basaltoids of the Okhotsk Massif, Russian Far East.Doklady Earth Sciences, Vol. 394, 1, Jan-Feb. pp. 32-38.RussiaPicrite
DS200512-0929
2004
Sakhno, V.G.Sakhno, V.G., Maksimov, S.O., Popov, V.K., Sandimirova, G.P.Leucite basanites and potassium shonkinites of the Uglovoe Basin, southern Primorye.Doklady Earth Sciences, Vol. 399A, Nov-Dec. pp. 1322-1326.RussiaBasanites, Foidites
DS200512-1154
2005
Sakhno, V.G.Vovna, G.M., Mishkin, M.A., Sakhno, V.G., Zhimulev, F.I.Origin of the diamond and coesite bearing metamorphic complexes.Doklady Earth Sciences, Vol. 403, 5, pp. 662-665.RussiaDiamond genesis
DS201012-0824
2010
Sakhno, V.G.Vovna, G.M., Mishkin, M.A., Sakhno, V.G., Zarubina, N.V.Early Archean sialic crust of the Siberian craton: the composition and origin of magmatic protoliths.Doklady Earth Sciences, Vol. 429, 2, pp. 1439-1442.RussiaMagmatism
DS2001-0721
2001
Sakho, V.G.Maksimov, S.O., Moiseenko, V.G., Sakho, V.G.High Potassium basalts of eruptive pipes from the eastern part of the Bureya Massif, Russian far east.Doklady Academy of Sciences, Vol. 379A, No. 6, July-August pp. 640-3.Russia, SiberiaPetrology, Bureya Massif
DS1986-0700
1986
Sakikawa, N.Sakikawa, N.Science of diamond.*JAPKyoritsu Shuppan Co, Tokyo, *JAP, JapanBlank
DS200712-0710
2007
Sakkas, V.Meju, M.A., Sakkas, V.Heterogeneous crust and upper mantle across southern Kenya and the relationship to surface deformation as inferred from magnetotelluric imaging.Journal of Geophysical Research, Vol. 112, B4, B04103.Africa, KenyaGeophysics
DS1999-0622
1999
Sakno, V.G.Sakno, V.G., Matyunin, A.P., Zimin, S.S.The mineral composition of Diamondiferous kimberlite type rocks in the northern Khanka Massif, primorsk ..Doklady Academy of Sciences, Vol. 368, No. 7, pp. 920-23.RussiaMineralogy, Deposit - Khanka Massif
DS1988-0417
1988
Sakovich, G.V.Liamkin, A.I., Petrov, E.A., Ershov, A.P., Sakovich, G.V.Production of diamonds from explosive substances.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 302, No. 3, pp. 611-613RussiaBlank
DS201212-0332
2012
Sakuai, H.Ishibashi, H., Kagi, H., Sakuai, H., Ohfuji, H., Sumino, H.Hydrous fluid as the growth media of natural polycrystalline diamond, carbonado: implication from IR spectra and microtextural observations.American Mineralogist, Vol. 97, pp. 1366-1372.Africa, Central African RepublicCarbonado
DS201412-0772
2014
Sakuma, H.Sakurai, M., Tsujino, N., Sakuma, H., Kawamura, K., Takahashi, E.Effects of Al content on water partitioning between orthopyroxene and olivine: implications for lithosphere-asthenosphere boundary.Earth and Planetary Science Letters, Vol. 400, pp. 284-291.MantleFT IR
DS200412-0932
2003
Sakuma, S.Joseph, E.J., Segawa, J., Kusumoto, S., Nakayama, E., Ishihara, T., Komazawa, M., Sakuma, S.Airborne gravimetry - a new gravimeter system and test results.Exploration Geophysics, Vol. 34, 1-2, pp. 82-86.TechnologyGeophysics - gravimetry not specific to diamonds
DS1975-1207
1979
Sakuntala, S.Sakuntala, S., Brahman, N.K.Some New Locales for Diamond Exploration in Andhra PradeshInstitute INDIAN PENINSULAR GEOLOGY, HYDERABAD., PP. 120-131.India, Andhra PradeshDiamond Prospecting, Occurrences
DS1984-0626
1984
Sakuntala, S.Sakuntala, S., Brahmam, N.K.Diamond Mines Near RaichurGeological Society INDIA Journal, Vol. 25, No. 12, DECEMBER PP. 780-786.India, KarnatakaDiamond Occurrences
DS201412-0772
2014
Sakurai, M.Sakurai, M., Tsujino, N., Sakuma, H., Kawamura, K., Takahashi, E.Effects of Al content on water partitioning between orthopyroxene and olivine: implications for lithosphere-asthenosphere boundary.Earth and Planetary Science Letters, Vol. 400, pp. 284-291.MantleFT IR
DS201707-1322
2017
Sakurai, M.Fei, H., Yamazaki, D., Sakurai, M., Miyajima, N., Ohfuji, H., Katsura, T., Yamamoto, T.A nearly water-saturated mantle transition zone inferred from mineral viscosity. Wadsleyite, ringwooditeScience Advances, Vol. 3, 6, 7p.Mantlewater

Abstract: An open question for solid-earth scientists is the amount of water in Earth’s interior. The uppermost mantle and lower mantle contain little water because their dominant minerals, olivine and bridgmanite, have limited water storage capacity. In contrast, the mantle transition zone (MTZ) at a depth of 410 to 660 km is considered to be a potential water reservoir because its dominant minerals, wadsleyite and ringwoodite, can contain large amounts of water [up to 3 weight % (wt %)]. However, the actual amount of water in the MTZ is unknown. Given that water incorporated into mantle minerals can lower their viscosity, we evaluate the water content of the MTZ by measuring dislocation mobility, a property that is inversely proportional to viscosity, as a function of temperature and water content in ringwoodite and bridgmanite. We find that dislocation mobility in bridgmanite is faster by two orders of magnitude than in anhydrous ringwoodite but 1.5 orders of magnitude slower than in water-saturated ringwoodite. To fit the observed mantle viscosity profiles, ringwoodite in the MTZ should contain 1 to 2 wt % water. The MTZ should thus be nearly water-saturated globally.
DS200812-0162
2008
Sakya, D.A.R.A.Burnistrov, A.A.A.A., Staostin, V.A.I.A., Sakya, D.A.R.A.Tectonic aspects of the evolution of ore potential of carbonatite and kimberlite magmatism.Doklady Earth Sciences, Vol. 418, 1, pp. 19-23.MantleMagmatism
DS200412-0066
2004
Sakyi, P.A.Asiedu, D.K., Dampare, S.B., Sakyi, P.A., Banoeng Yakubo, B., Osae, S., Nyarko, B.J.B., Manu, J.Geochemistry of Paleoproterozoic metasedimentary rocks from the Birim Diamondiferous field: implications for provenance and crusGeochemical Journal, Vol. 38, 3, pp. 215-228.Africa, GhanaGeochemistry - Archean Proterozoic boundary
DS201012-0764
2010
Sakyi, P.A.Su, B., Zhang, H., Tang, Y., Chisonga, B., Qin, K., Ying, J., Sakyi, P.A.Geochemical syntheses among the cratonic, off-cratonic and orogenic garnet peridotites and their tectonic implications.International Journal of Earth Sciences, In press available, 21p.MantlePeridotite, geochemistry
DS201012-0765
2010
Sakyi, P.A.Su, B-X., Zhang, H-F., Sakyi, P.A., Yang, Y-H., Ying, J-F., Tang, Y-J., Qin, K-Z., Xiao, Y., Zhao, Mao, MaThe origin of spongy texture in minerals of mantle xenoliths from the western Qinling, central China.Contributions to Mineralogy and Petrology, in press available, 18p.ChinaXenoliths
DS201012-0766
2010
Sakyi, P.A.Su, B-X., Zhang, H-F., Sakyi, P.A., Ying, J-F., Tang, Y-J., Yang, Y-H., Qin, K-Z., Xiao, Y., Zhao, X-M.Compositionally stratified lithosphere and carbonatite metasomatism recorded in mantle xenoliths from the Western Qinling (Central China).Lithos, Vol. 116, pp. 111-128.ChinaCarbonatite
DS201112-1015
2011
Sakyi, P.A.Su, B., Zhang, H., Tang, Y., Chisonga, B., On, K., Ying, J., Sakyi, P.A.Geochemical syntheses among the cratonic, off cratonic and orogenic garnet peridotites and their tectonic implications.International Journal of Earth Sciences, Vol. 100, 4, pp.695-715.MantleCraton, kimberlites mentioned
DS201412-0889
2014
Sakyi, P.A.Su, B-X., Zhang, H-F., Deloule, E., Vigier, N., Hu, Y., Tang, H-J., Xiao, Y., Sakyi, P.A.Distinguishing silicate and carbonatite mantle metasomatism by using lithium and its isotopes.Chemical Geology, Vol. 381, pp. 67-77.ChinaXenoliths - Hannuoba
DS202112-1954
2021
Sakyi, P.A.Wang, J., Su, B-X., Ferrero, S., Malaviarachchi, S.P.K., Sakyi, P.A., Yang, Y-H., Dharmapriya, P.L.Crustal derivation of the ca 475 Ma Eppawala carbonatites in Sri Lanka.Journal of Petrology, Vol. 62, 11, pp.1-18. pdfAsia, Sri Lankacarbonatite

Abstract: Although a mantle origin of carbonatites has long been advocated, a few carbonatite bodies with crustal fingerprints have been identified. The Eppawala carbonatites in Sri Lanka are more similar to orogenic carbonatites than those formed in stable cratons and within plate rifts. They occur within the Pan-African orogenic belt and have a formation age of ca. 475 Ma newly obtained in this study with no contemporary mantle-related magmatism. These carbonatites have higher (87Sr/86Sr)i ratios (0•70479-0•70524) and more enriched Nd and Hf isotopic compositions than carbonatites reported in other parts of the world. Model ages (1•3-2•0 Ga) of both Nd and Hf isotopes [apatite ?Nd(t)?=??9•2 to ?4•7; rutile ?Hf(t)?=??22•0 to ?8•02] are in the age range of metamorphic basement in Sri Lanka, and the carbon and oxygen isotopic compositions (?13CPDB?=??2•36 to ?1•71; ?18OSMOW?=?13•91-15•13) lie between those of mantle-derived carbonatites and marble. These crustal signatures are compatible with the chemistry of accessory minerals in the carbonatites, such as Ni-free olivine and Al- and Cr-poor rutile. Modeling results demonstrate that the Eppawala carbonatite magmas originated from a mixture of basement gneisses and marbles, probably during regional metamorphism. This interpretation is supported by the occurrence of the carbonatites along, or near, the axes of synforms and antiforms where granitic gneiss and marble are exposed. Therefore, we propose that the Eppawala carbonatites constitute another rare example of a carbonatitic magma that was derived from melting of a sedimentary carbonate protolith. Our findings suggest that other orogenic carbonatites with similar features should be re-examined to re-evaluate their origin.
DS1996-1247
1996
Salah Ama, I.Salah Ama, I., Liegeois, J-P., Pouclet, A.Evolution d'un arc insulaire oceanique birimien precoce au Liptako nigerien(Sirba) geologie, geochronologieJournal of African Earth Sciences, Vol. 22, No. 3, pp. 235-254Nigeria, West Africa, Burkina FasoBirimian Domain, Magma
DS202205-0672
2022
Salajeghegh, F.Afonso, J., Ben-Mansour, W., O'Reilly, S.Y., Griffin, W.L., Salajeghegh, F., Foley, S., Begg, G., Selway, K., Macdonald, A., Januszczak, N., Fomin, I., Nyblade, A.A., Yang, Y.Thermochemical structure and evolution of cratonic lithosphere in central and southern Africa.Nature Geoscience, Apr. 26, 329p. FreeAfrica, South AfricaCraton

Abstract: The thermochemical structure of the subcontinental mantle holds information on its origin and evolution that can inform energy and mineral exploration strategies, natural hazard mitigation and evolutionary models of Earth. However, imaging the fine-scale thermochemical structure of continental lithosphere remains a major challenge. Here we combine multiple land and satellite datasets via thermodynamically constrained inversions to obtain a high-resolution thermochemical model of central and southern Africa. Results reveal diverse structures and compositions for cratons, indicating distinct evolutions and responses to geodynamic processes. While much of the Kaapvaal lithosphere retained its cratonic features, the western Angolan-Kasai Shield and the Rehoboth Block have lost their cratonic keels. The lithosphere of the Congo Craton has been affected by metasomatism, increasing its density and inducing its conspicuous low-topography, geoid and magnetic anomalies. Our results reconcile mantle structure with the causes and location of volcanism within and around the Tanzanian Craton, whereas the absence of volcanism towards the north is due to local asthenospheric downwellings, not to a previously proposed lithospheric root connecting with the Congo Craton. Our study offers improved integration of mantle structure, magmatism and the evolution and destruction of cratonic lithosphere, and lays the groundwork for future lithospheric evolutionary models and exploration frameworks for Earth and other terrestrial planets.
DS201604-0590
2015
Salamatin, A.V.Alexakhin, V.Yu., Bystritsky, V.M., Zamyatin, N.I., Zubarev, E.V., Krasnoperov, A.V., Rapatsky, V.L., Rogov, Yu.N., Sadovsky, A.B., Salamatin, A.V., Salmin, R.A., Sapozhnikov, M.G., Slepnev, V.M., Khabarov, S.V., Razinkov,E.A., Tarasov, O.G., Nikitin,G.M.Detection of diamonds in kimberlite by the tagged neutron method.Nuclear Instruments and Methods in Physics Research Section A., A785, pp. 9-13.TechnologyMethodology

Abstract: A new technology for diamond detection in kimberlite based on the tagged neutron method is proposed. The results of experimental researches on irradiation of kimberlite samples with 14.1-MeV tagged neutrons are discussed. The source of the tagged neutron flux is a portable neutron generator with a built-in 64-pixel silicon alpha-detector with double-sided stripped readout. Characteristic gamma rays resulting from inelastic neutron scattering on nuclei of elements included in the composition of kimberlite are registered by six gamma-detectors based on BGO crystals. The criterion for diamond presence in kimberlite is an increased carbon concentration within a certain volume of the kimberlite sample.
DS200812-1209
2008
Salanikova, E.A.B.A.Vernikovsky, V.A.A., Vernikovskaya, A.A.E.A., Salanikova, E.A.B.A., Berezhnaya, Larionov, Kotov, KovachLate Riphean alkaline magmatism in the western margin of the Siberian craton: a result of continental rifting or accretionary events?Doklady Earth Sciences, Vol. 419, 2, pp. 226-230.RussiaMagmatism
DS201212-0278
2012
Salanne, M.Haigis, V., Salanne, M., Jahn, S.Thermal conductivity of minerals in the Earth's lower mantle from molecular dynamics.emc2012 @ uni-frankfurt.de, 1p. AbstractMantleGeothermometry
DS201212-0279
2012
Salanne, M.Haigis, V., Salanne, M., Jahn, S.Thermal conductivity of MgO, MgSiO3 perovskite and post-perovskite in the Earth's deep mantle.Earth and Planetary Science Letters, Vol. 355-356, pp. 102-108.MantleGeothermometry
DS201902-0293
2019
Salari, G.Lustrino, M., Fedele, L., Agostini, S., Prelevic, D., Salari, G.Leucitites within and around the Mediterranean area. Lithos, Vol. 324-325, pp. 216-233.Europeleucitites

Abstract: Leucite-bearing volcanic rocks are commonly found within and around the Mediterranean area. A specific type of this rock group are leucitites. They are found both in a hinterland position of active and fossil subduction systems as well as in foreland tectonic settings, but none have been found in the Maghreb (N Africa) and Mashreq (Middle East) areas. Here a review of the main leucitite occurrences in the circum-Mediterranean area is presented, with new whole-rock, mineral chemical and Sr-Nd-Pb isotopic ratios on key districts, with the aim of clarifying the classification and genesis of this rock type. Many of the rocks classified in literature as leucitites do not conform to the IUGS definition of leucitite (i.e., rocks with >10?vol% modal leucite and with foids/(foids + feldspars) ratio?>?0.9, with leucite being the most abundant foid). Among circum-Mediterranean rocks classified as leucitites in the literature, we distinguish two types: clinopyroxene-olivine-phyric (COP) and leucite- phyric (LP) types. Only the second group can be truly classified as leucitite, being characterized by the absence or the very rare presence of feldspars, as well as by ultrapotassic composition. The COP group can be distinguished from the LP group on the basis of lower SiO2, Na2O?+?K2O, K2O/Na2O, Al2O3, Rb and Ba, and higher MgO, TiO2, Nb, Cr and Ni. The LP group shows multi-elemental patterns resembling magmas emplaced in subduction-related settings, while COP rocks are much more variable, showing HIMU-OIB-like to subduction-related-like incompatible element patterns. COP rocks are also characterized generally by more homogeneous isotopic compositions clustering towards low Sr and high Nd isotopic ratios, while LP leucitites plot all in the enriched Sr-Nd isotopic quadrant. LP rocks usually have lower 206Pb/204Pb and higher 207Pb/204Pb. This study shows that the geochemical signal of mantle melts does not always reflect the tectonic setting of magma emplacement, suggesting paying extreme attention in proposing geodynamic reconstructions on the basis of chemical data only.
DS202111-1773
2021
Salari, G.Lustrino, M., Salari, G., Rahimzadeh, B., Fede;e, L. Masoudi, F., Agostini, S.Quaternary melanephelinites and melilitites from Nowbaran ( NW Urumieh-Dokhtar magmatic arc, Iran): origin of ultrabasic-ultracalcic melts in a post-collional setting.Journal of Petrology, Vol. 62, 9, pp. 1-31. pdfAsia, Iranmelilitite

Abstract: The small Quaternary volcanic district of Nowbaran (NW Iran) belongs to the Urumieh-Dokhtar Magmatic Arc, a ?1800-km long NW-SE striking Cenozoic belt characterized by the irregular but abundant presence of subduction-related igneous products. Nowbaran rocks are characterized by absence of feldspars coupled with abundance of clinopyroxene and olivine plus nepheline, melilite and other rarer phases. All the rocks show extremely low SiO2 (35.4-41.4?wt%), very high CaO (13.1-18.3?wt%) and low Al2O3 (8.6-11.6?wt%), leading to ultracalcic compositions (i.e. CaO/Al2O3?>?1). Other less peculiar, but still noteworthy, characteristics are the high MgO (8.7-13.3?wt%) and Mg# (0.70-0.75), coupled with a variable alkali content with sodic affinity (Na2O?=?1.8-5.4?wt%; K2O?=?0.2-2.3?wt%) and variably high LOI (1.9-10.4?wt%; average 4.4?wt%). Measured isotopic ratios (87Sr/86Sr?=?0.7052-0.7056; 143Nd/144Nd?=?0.51263-0.51266; 206Pb/204Pb?=?18.54-18.66; 207Pb/204Pb?=?15.66-15.68; 208Pb/204Pb?=?38.66-38.79) show small variations and plot within the literature field for the Cenozoic volcanic rocks of western Iran but tend to be displaced towards slightly higher 207Pb/204Pb. Primitive mantle-normalized multielemental patterns are intermediate between typical subduction-related melts and nephelinitic/melilititic melts emplaced in intraplate tectonic settings. The enrichment in Th, coupled with high Ba/Nb and La/Nb, troughs at Ti in primitive mantle-normalized patterns, radiogenic 87Sr/86Sr and positive ?7/4 anomalies (from +15.2 to +17.0) are consistent with the presence of (old) recycled crustal lithologies in the sources. The origin of Nowbaran magmas cannot be related to partial melting of C-H-free peridotitic mantle, nor to digestion of limestones and marls by ‘normal’ basaltic melts. Rather, we favour an origin from carbonated lithologies. Carbonated eclogite-derived melts or supercritical fluids, derived from a subducted slab, reacting with peridotite matrix, could have produced peritectic orthopyroxene- and garnet-rich metasomes at the expenses of mantle olivine and clinopyroxene. The residual melt compositions could evolve towards SiO2-undersaturated, CaO- and MgO-rich and Al2O3-poor alkaline melts. During their percolation upwards, these melts can partially freeze reacting chromatographically with portions of the upper mantle wedge, but can also mix with melts from shallower carbonated peridotite. The T-P equilibration estimates for Nowbaran magmas based on recent models on ultrabasic melt compositions are compatible with provenance from the lithosphere-asthenosphere boundary at average temperature (?1200°C?±?50°C). Mixing of melts derived from subduction-modified mantle sources with liquids devoid of any subduction imprint, passively upwelling from slab break-off tears could generate magmas with compositions recorded in Nowbaran.
DS2002-0160
2002
Salas, R.Bitzer, K., Salas, R.SIMSAFADIM: a three dimensional simulation of stratigraphic architecture and facies distribution modeling of carbonate sediments.Computers and Geosciences, Vol. 28, 10, pp.1177-92.GlobalComputers - programs
DS1998-0613
1998
Salawa, F.Henning, Th., Salawa, F.Carbon in the universeScience, Vol. 282, No. 5397, Dec. 18, pp. 2204-10.MantleCarbon
DS202106-0968
2021
Salazar-Mora, C.Salazar-Mora, C., Sacek, V.Lateral flow of thick continental lithospheric mantle during tectonic quiescence.Journal of Geodynamics, Vol. 146, 101830, 9p. PdfMantlecraton

Abstract: The amalgamation of continental blocks naturally results in a lithosphere with lateral variations in thickness due to the juxtaposition of thicker cratonic and thinner orogenic lithospheres, which in turn evolve together through time. After the amalgamation, this mosaic of continental blocks can experience longstanding periods of relative tectonic quiescence until the next tectonic event, for instance continental rifting. Using geodynamic numerical models, we explored the internal deformation of the continental lithosphere during periods of tectonic quiescence taking into account lateral variations of lithospheric thickness. We observed that the orientation of lateral flow of the thick cratonic lithosphere depends primarily on the compositional density contrasts (??) between the asthenosphere and continental lithospheric mantle and on the width of the juxtaposed mobile belt lithosphere. In the case of mobile belts wider than 300 km, the margin of the thick craton flows towards (or underplates) the base of the thin lithosphere when ?? ? 32?48 kg/m3, whereas for smaller ?? values, the thick cratonic margin flows away from mobile belt, preserving a sharp thickness variation. For mobile belts narrower than 300 km, the ?? threshold between underplate or outward behavior decreases with the mobile belt width. Underplating of cratonic lithosphere beneath the thin lithosphere is efficient in mobile belts narrower than 300 km and for higher ??, which allows them to cool, thicken and stiffen. Lateral flow of cratonic lithosphere is not efficient to underplate wide mobile belts thoroughly, so the latter are influenced by asthenospheric heat for prolonged periods and thus remain less rigid. Therefore, we propose that protracted tectonic quiescence of supercontinents can develop lithospheric rheological inheritances that may or may not facilitate post-quiescence continental lithospheric rifting.
DS201810-2376
2018
Salazar-Mora, C.A.Salazar-Mora, C.A., Huismans, R.S., Fossen, H., Egydio-Silva, M.The Wilson cycle and effects of tectonic structural inheritance on rifted passive margin formations.Tectonics, doi.org/10.1029/ 2018TC004962Oceanstectonics

Abstract: The parallelism between older collisional belts and younger rift systems is widely known and particularly well portrayed along the Atlantic Ocean. How tectonic inherited and new?formed shear zones control rift nucleation and the final architecture of rifted conjugate passive margins is still poorly understood. Here we present lithospheric?scale thermo?mechanical numerical models that self?consistently create extensional and contractional tectonic inheritance, where prior extension and contraction are systematically varied. Our results show that (1) initial reactivation occurs along the former lithospheric suture zones; (2) upper crustal thick?skinned basement thrusts are partially or fully reactivated depending on the amount of prior contraction and size of the orogen; (3) with a small amount of contraction, thick?skinned thrusts are efficiently reactivated in extension and provide the template for rifted margin formation; (4) with larger amounts of contraction, thick?skinned thrusts distal to the lithospheric suture zone do not reactivate in extension; and (5) reactivation of prior contractional shear zones dominates during the early stages of rifting, while during the final stage of margin formation new?formed extensional shear zones dominate. Force balance analysis predicts an inverse relation between midcrustal viscosity and the maximum offset for reactivation of weak upper crustal structures. Force balance also predicts that the degree of weakening or healing of the weak suture and the thermal thinning of the necking area control at which stage suture reactivation is deactivated and extension proceeds by mantle lithosphere thermal necking. Two rifted conjugate margins with orogenic inheritance in the North and South Atlantic are used for comparison.
DS1996-1354
1996
Salda, L.H. dalla.Spaletti, L.A., Salda, L.H. dalla.A pull apart volcanic related Tertiary Basin, an example from the Patagonian AndesJournal of South American Earth Sciences, Vol. 9, No. 3/4, pp. 197-206Peruvolcanism., Tectonics
DS2002-1482
2002
Sale, M.J. Soechting et al.Sillitoe, R.H., Cooper, C., Sale, M.J. Soechting et al.Discovery and geology of the Esquel low sulfidation epithermal gold deposit, Patagonia, Argentina.Society of Economic Geologists Special Publication, No.9,pp.227-40.Argentina, PatagoniaGold, Deposit - Esquel
DS1992-1320
1992
Saleby, J.B.Saleby, J.B.Age and tectonic setting of the Duke Island ultramafic intrusion, southeastAlaskaCanadian Journal of Earth Sciences, Vol. 29, No. 3, March pp. 506-522AlaskaTectonics, Duke Island
DS1998-0368
1998
Saleeby, J.Ducea, M., Saleeby, J.Crustal recycling beneath continental arcs: silica rich glass inclusions inEarth and Planetary Science Letters, Vol. 156, No. 1-2, Mar. 15, pp. 101-116.California, Sierra NevadaXenoliths, Subduction
DS200512-0249
2005
Saleeby, J.Ducea, M.N., Saleeby, J., Morrison, J., Valencia, V.A.Subducted carbonates, metasomatism of mantle wedges, and possible connections to diamond formation: an example from California.American Mineralogist, Vol. 90, pp. 864-870.United States, CaliforniaSierra Nevada mantle, peridotites
DS1990-1273
1990
Saleeby, J.B.Rubin, C.M., Saleeby, J.B., Cowan, D.S., Brandon, M.T., McGroderRegionally extensive mid-Cretaceous west-vergent thrust system in the northwestern Cordillera: implications for continent-margin tectonisM.Geology, Vol. 18, No. 3, March pp. 276-280British ColumbiaTectonics, Thrust system
DS1992-1690
1992
Saleeby, J.B.Wolf, M.B., Saleeby, J.B.Jurassic Cordilleran dike swarm- shear zones: implications for the Nevada norogeny and North American plate motionGeology, Vol. 20, No. 8, August pp. 745-748CaliforniaOwens Mountain area, Tectonics, shear zones
DS1996-0361
1996
Saleeby, J.B.Dickinson, W.R., Hopson, C.A., Saleeby, J.B.Alternate origins of the Coast Range ophiolite (California): introduction and implicationsGsa Today, Vol. 6, No. 2, Feb. pp. 1-10CaliforniaOphiolites, Lithosphere
DS1996-0390
1996
Saleeby, J.B.Ducea, M.N., Saleeby, J.B.Bouyancy sources for a large uprooted mountain range, Sierra Nevada, California: evidence from xenoliths...Journal of Geophysical Research, Vol. 101, No. B4, April 10, pp. 8229-8244.CaliforniaMantle xenoliths, Sierra Nevada
DS1998-0369
1998
Saleeby, J.B.Ducea, M.N., Saleeby, J.B.The age and origin of a thick mafic ultramafic keel from beneath the Sierra Nevada Batholith.Contributions to Mineralogy and Petrology, Vol. 133, No. 1-2, pp. 169=85.Nevada, Colorado PlateauTectonics
DS201607-1294
2016
Saleeby, J.B.Ducea, M.N., Saleeby, J.B., Bergantz, G.The architecture, chemistry and evolution of continental magmatic arcs.Annual Review of Earth and Planetary Sciences, Vol. 43, pp. 299-331.MantleMagmatism

Abstract: Continental magmatic arcs form above subduction zones where the upper plate is continental lithosphere and/or accreted transitional lithosphere. The best-studied examples are found along the western margin of the Americas. They are Earth's largest sites of intermediate magmatism. They are long lived (tens to hundreds of millions of years) and spatially complex; their location migrates laterally due to a host of tectonic causes. Episodes of crustal and lithospheric thickening alternating with periods of root foundering produce cyclic vertical changes in arcs. The average plutonic and volcanic rocks in these arcs straddle the compositional boundary between an andesite and a dacite, very similar to that of continental crust; about half of that comes from newly added mafic material from the mantle. Arc products of the upper crust differentiated from deep crustal (>40 km) residual materials, which are unstable in the lithosphere. Continental arcs evolve into stable continental masses over time; trace elemental budgets, however, present challenges to the concept that Phanerozoic arcs are the main factories of continental crust.
DS201506-0264
2015
Salem, A.K.A.El-Desoky, H., Khalil, A.E., Salem, A.K.A.Ultramafic rocks in Gabal El-Rubshi, Central Eastern Desert, Egypt: petrography, mineral chemistry, and geochemistry constraints.Arabian Journal of Geosciences, Vol. 8, 5, pp.2607-2631.Africa, EgyptUltramafic rocks - general
DS1994-0873
1994
Salemink, J.Kampata, D.M., Nixon, P.H., Salemink, J., Demaiffe, D.Monticellite in the Ghena kimberlite (Shaba, Zaire) -evidence of late magmatic crystallization.Mineralogical Magazine, Vol. 58, No. 392, Sept. 496-500.Democratic Republic of CongoMineralogy -monticellite, Deposit -Shaba
DS1987-0545
1987
Salfity, J.A.Omarin, R.H., Salfity, J.A., Linares, E., Viramonte, J.G.Petrology, geochemistry and age of a lamproite dike In the PirguaSubgroup, Alemania, Salta. SPA.Revista del Instituto de Geologia y Mineria, *SPA., No. 7, pp. 89-99GlobalLamproite, Geochemistry
DS201412-0038
2014
Salgado, A.A.RBarreto, H.N., Varajao, C.A.C., Braucher, R., Bourles, D.L., Salgado, A.A.R, Varajao, A.F.D.C.The impact of diamond extraction on natural denudation rates in the Diamantin a Plateau ( Min as Gerais, Brazil).Journal of South American Earth Sciences, Vol 56, pp. 357-364.South America, BrazilMining
DS201212-0063
2012
Sali, D.Bedini, A., Ehrman, S., Nunziante Cesaro, S., Pasini, M., Rapinesi, I.A., Sali, D.The Vallerano diamond from ancient Rome: a scientific study.Gems & Gemology, Vol. 48, 1, pp.TechnologyDiamond - notable
DS201212-0064
2012
Sali, D.Bedini, A., Ehrman, S., Nunziante Cesaro, S., Pasini, M., Rapinesi, I.A., Sali, D.The Vallerano diamond from ancient Rome: a scientific study.Gems & Gemology, Vol. 48, 1, Spring pp. 39-41.GlobalHistory - diamond notable
DS1994-1516
1994
Salifty, J.A.Salifty, J.A.Cretaceous tectonics of the AndesVieweg European Publ, 330pSouth America, Colombia, Bolivia, Chile, ArgentinaTectonics, Book -Table of contents
DS201909-2105
2019
Salih, M-A.Wang, L-X., Ma, C-Q., Salih, M-A., Abdallisamed, M-I-M., Zhu, Y-X.The syenite-carbonatite-fluorite association in Jebel Dumbier complex ( Sudan): magma origin and evolution.Goldschmidt2019, 1p. Poster abstractAfrica, Sudancarbonatite

Abstract: Jebel Dumbier is the first-identified carbonatite-bearing alkaline complex in Sudan. It is located on the northeastern margin of the Nuba Mountains in the south part of Sudan. The complex exposed as small elliptical hills with outcrops of around 8 km2. It is composed of dominant orthoclasite and ditroite and subdominant carbonatite and fluorite dykes. The fluorite dykes are mined and together with the carbonatite dykes are controlled by a NNE strike-slip fault system. Orthoclasite is the dominant rock type, comprising of orthoclase, kalsilite, few interstitial biotite and calcium carbonate and accesserary minerals of fluorite, apatite and zircon. Ditroite consists of perthite, aegirine-augite, nepheline, sodalite, and minor annite-phlogopite and richterite, with common accessories of fluorite, titanite, apatite and zircon. Zircon U-Pb dating reveals that both orthoclasite and ditroite emplaced at around 600 Ma. Relative to orthoclasites, ditroites display higher FeOtotal and MgO and lower Al2O3 contents, contain higher volatiles (F, Cl, Br, S), and are more depleted in LILEs (Rb, Sr, Ba) and enriched in HFSEs (Nb, Ta, Zr, Hf, Th, U) and REEs. Isotopic data imply that the ditoite, orthoclasite, fluorite and carbonatite dyke originated from a common source of depleted mantle affinities, with identical low initial 87Sr/86Sr ratios (0.7033-0.7037) and high ?Nd (t) values (1.6-2.7). The carbonatites display ?13C(V-PDB) of -5.8 to -6.7‰ and ?18O(SMOW) of 9.1 to 11.3‰, typical of primary igneous carbonatite worldwide. We propose that the orthoclasite, ditroite, carbonatite, and fluorite association in Jebel Dumbier is product of variable degrees of fractional crystallization of mantlederived volatile-rich magma. Magma immiscibility among silicates, carbonates and fluorates may proceed. The Jebel Dumbier alkaline-carbonatite complex represents the postorogenic alkaline magmatism during the end evolution of Pan-African orogen (650-550 Ma) at Arabian-Nubian Shield.
DS201412-0020
2014
Salikhov, R.Ashchepkov, I., Remirs, L., Ntaflos, T., Vladykin, N., Logvinova, A., Travin, A., Yudin, D., Karpenko, K., Makovchuk, I., Palessky, S., Salikhov, R.Evolution of mantle column of pipe Sytykanskaya, Yakutia kimberlite.Goldschmidt Conference 2014, 1p. AbstractRussia, YakutiaDeposit - Sytykanskaya
DS201705-0808
2017
Salikhov, R.Ashchepkov, I., Ntaflos, T., Logvinova, A., Vladykin, N., Ivanov, A., Spetsius, Z., Stegnitsky, Y., Kostrovitsky, S., Salikhov, R., Makovchuk, I., Shmarov, G., Karpenko, M., Downes, H., Madvedev, N.Evolution of the mantle sections beneath the kimberlite pipes example of Yakutia.European Geosciences Union General Assembly 2017, Vienna April 23-28, 1p. 6337 AbstractRussia, YakutiaDeposit - Sytykanskaya, Dalnyaya, Aykhal, Zarya, Komosomolskaya, Zarnitsa, Udachnaya

Abstract: The PTX diagrams for the separate phases in Sytykanskaya (Ashchepkov et al., 2016) Dalnyaya (Ashchepkov et al., 2017), pipes shows that the PK show the relatively simple P-X trends and geotherms and shows more contrast and simple layering. The PK contain most abundant material from the root of the magma generation they are dunitic veins as the magma feeders represented by the megacrysts. New results for the Aykhal, Zarya and Komsomolskaya pipes in Alake field and Zarnitsa and Udachnaya pipes in Daldyn field show that evolution is accompanied by the developing of metasomatites and branching and veining of the wall rock peridotites . In Aykhal pipe in PK the Gar- dunites prevail, the xenoliths from the dark ABK "Rebus" contain Cr-Ti - rich garnets and ilmenites, more abundant compared with the grey carbonited breccia Nearly the same features were found for Yubileinaya pipe. The example of Komsomolskya pipes show that the ABK contain more eclogitic xenolith than PK. The developing of the magma channel shown in satellite Chukukskaya and Structurnaya pipe was followed by the separation of some parts of the magmatic feeders and crystallization of abundant Gar megacrysts near o the walls blocking the peridotites from the magma feeder. This drastically decrease diamond grade of pipes. Such blocking seems to be the common features for the latest breccias. In Zarnitsa pipe, the dark PK and ABK also contain fresh xenoliths but not only dunites but also sheared and metasomatic varieties and eclogites. Most of dark ABK in Yakutia contain the intergrowth of ilmenites with brown Ti- Cpx showing joint evolution trends. The late breccia contains completely altered peridotite xenoliths mainly of dunite- harzburgite type. The comparison of the trace elements of the coexisting minerals in megacryst show that they were derived from the protokimberlites but are not in complete equilibrium as well as other megacrystalline phases. Ilmenites show inflections of the trace element patterns of most Ilmenites but more regular for the Cpx and Garnets revealing the sub parallel patterns elevating LREE with the rising TRE. But commonly these are not continuous sequances because they developed in the pulsing moving systems like beneath Zarnitsa. The minerals from the feeders like dunites also show the inflected or S-type REE patterns. From the earlier to later phases the TRE compositions became more evolved reflecting the evolution of protokimberlites. The wall rocks also often show the interaction with the more evolved melts and sometimes "cut" spectrums due to the dissolution some phases and repeated melting events So we could suggest the joint evolution of the mantle column protokimberlites and megacrysts composition and type of kimberlites with the diamond grade. The mantle lithospheric base captured by the PK. The developing and rising protokimbelrites was followed by the crystallization of the diamonds in the gradient in FO2 zone in wall rocks due to reductions of C -bearing fluids and carbonatites (> 1 QMF) on peridotites ((< -2 -5 QMF). The most intensive reactions are near the graphite - diamond boundary where protokimberlites are breaking and where most framesites are forming.
DS201312-0032
2013
Salikhov, R.F.Ashchepkov, I.V., Alymova, N.V., Logvinova, A.M., Vladykin, N.V., Kuligin, S.S., Mityukhin, S.I., Stegnitsky, Y.B., Prokopyev, S.A., Salikhov, R.F., Palessky, V.S., Khmelnikova, O.S.Picroilmenites in Yakutian kimberlites: variations and genetic models.Solid Earth, Vol. 5, pp. 1259-1334.Russia, YakutiaDeposits
DS201412-0021
2014
Salikhov, R.F.Ashchepkov, I.V., Alymova, N.V., Lognova, A.M., Vladykin, N.V., Kuligin, S.S., Lityukhin, S.I., Downes, H., Stegnitsky, Yu.B., Prokopiev, S.A., Salikhov, R.F., Palessky, V.S., Khmelnikova, O.S.Picroilmenites in Yakutian kimberlites: variations and genetic models.Solid Earth, Vol. 5, pp. 915-938.Russia, YakutiaKimberlite genesis
DS201412-0022
2014
Salikhov, R.F.Ashchepkov, I.V., Vladykin, N.N., Ntaflos, T., Kostrovitsky, S.I., Prokopiev, S.A., Downes, H., Smelov, A.P., Agashev, A.M., Logvinova, A.M., Kuligin, S.S., Tychkov, N.S., Salikhov, R.F., Stegnitsky, Yu.B., Alymova, N.V., Vavilov, M.A., Minin, V.A., BabusLayering of the lithospheric mantle beneath the Siberian Craton: modeling using thermobarometry of mantle xenolith and xenocrysts. Tectonophysics, Vol. 634, 5, pp. 55-75.Russia, YakutiaDaldyn, Alakit, Malo-Botuobinsky fields
DS201612-2276
2016
Salikhov, R.F.Ashchepkov, I.V., Ntaflos, T., Spetius, Z.V., Salikhov, R.F., Downes, H.Interaction between protokimberlite melts and mantle lithosphere: evidence from mantle xenoliths from the Dalnyaya kimberlite pipe, Yakutia, Russia.Geoscience Frontiers, in press availableRussia, YakutiaDeposit - Dalnyaya

Abstract: The Dalnyaya kimberlite pipe (Yakutia, Russia) contains mantle peridotite xenoliths (mostly lherzolites and harzburgites) that show both sheared porphyroclastic (deformed) and coarse granular textures, together with ilmenite and clinopyroxene megacrysts. Deformed peridotites contain high-temperature Fe-rich clinopyroxenes, sometimes associated with picroilmenites, which are products of interaction of the lithospheric mantle with protokimberlite related melts. The orthopyroxene-derived geotherm for the lithospheric mantle beneath Dalnyaya is stepped similar to that beneath the Udachnaya pipe. Coarse granular xenoliths fall on a geotherm of 35 mWm?2 whereas deformed varieties yield a 45 mWm?2 geotherm in the 2-7.5 GPa pressure interval. The chemistry of the constituent minerals including garnet, olivine and clinopyroxene shows trends of increasing Fe# (=Fe/(Fe + Mg)) with decreasing pressure. This may suggest that the interaction with fractionating protokimberlite melts occurred at different levels. Two major mantle lithologies are distinguished by the trace element patterns of their constituent minerals, determined by LA-ICP-MS. Orthopyroxenes, some clinopyroxenes and rare garnets are depleted in Ba, Sr, HFSE and MREE and represent relic lithospheric mantle. Re-fertilized garnet and clinopyroxene are more enriched. The distribution of trace elements between garnet and clinopyroxene shows that the garnets dissolved primary orthopyroxene and clinopyroxene. Later high temperature clinopyroxenes related to the protokimberlite melts partially dissolved these garnets. Olivines show decreases in Ni and increases in Al, Ca and Ti from Mg-rich varieties to the more Fe-rich, deformed and refertilized ones. Minerals showing higher Fe# (0.11-0.15) are found within intergrowths of low-Cr ilmenite-clinopyroxene-garnet related to the crystallization of protokimberlite melts in feeder channels. In P-f(O2) diagrams, garnets and Cr-rich clinopyroxenes indicate reduced conditions at the base of the lithosphere at ?5 log units below a FMQ buffer. However, Cr-poor clinopyroxenes, together with ilmenite and some Fe-Ca-rich garnets, demonstrate a more oxidized trend in the lower part of lithosphere at ?2 to 0 log units relative to FMQ. Clinopyroxenes from xenoliths in most cases show conditions transitional between those determined for garnets and megacrystalline Cr-poor suite. The relatively low diamond grade of Dalnyaya kimberlites is explained by a high degree of interaction with the oxidized protokimberlite melts, which is greater at the base of the lithosphere.
DS202010-1829
2013
Salikhov, R.F.Ashchepkov, I.V., Alymova, N.V., Loginova, A.M., Vladykin, N.V., Kuligin, S.S., Mityukhin, S.I., Stegnitsky, Y.B., Prokopiev, S.A., Salikhov, R.F., Palessky, V.S., Khmelnikova, O.S.Picroilmenites in Yakutian kimberlites: variations and genetic models. Solid Earth Discussions, Vol. 5, pp. 1-75. pdf * note dateRussia, Yakutiapicroilmenites

Abstract: Major and trace element variations in picroilmenites from Late Devonian kimberlite pipes in Siberia reveal similarities within the region in general, but show individual features for ilmenites from different fields and pipes. Empirical ilmenite thermobarometry (Ashchepkov et al., 2010), as well as common methods of mantle thermobarometry and trace element geochemical modeling, shows long compositional trends for the ilmenites. These are a result of complex processes of polybaric fractionation of protokimberlite melts, accompanied by the interaction with mantle wall rocks and dissolution of previous wall rock and metasomatic associations. Evolution of the parental magmas for the picroilmenites was determined for the three distinct phases of kimberlite activity from Yubileynaya and nearby Aprelskaya pipes, showing heating and an increase of Fe# (Fe# = Fe / (Fe + Mg) a.u.) of mantle peridotite minerals from stage to stage and splitting of the magmatic system in the final stages. High-pressure (5.5-7.0 GPa) Cr-bearing Mg-rich ilmenites (group 1) reflect the conditions of high-temperature metasomatic rocks at the base of the mantle lithosphere. Trace element patterns are enriched to 0.1-10/relative to primitive mantle (PM) and have flattened, spoon-like or S- or W-shaped rare earth element (REE) patterns with Pb > 1. These result from melting and crystallization in melt-feeding channels in the base of the lithosphere, where high-temperature dunites, harzburgites and pyroxenites were formed. Cr-poor ilmenite megacrysts (group 2) trace the high-temperature path of protokimberlites developed as result of fractional crystallization and wall rock assimilation during the creation of the feeder systems prior to the main kimberlite eruption. Inflections in ilmenite compositional trends probably reflect the mantle layering and pulsing melt intrusion during melt migration within the channels. Group 2 ilmenites have inclined REE enriched patterns (10-100)/PM with La / Ybn ~ 10-25, similar to those derived from kimberlites, with high-field-strength elements (HFSE) peaks (typical megacrysts). A series of similar patterns results from polybaric Assimilation + fractional crystallization (AFC) crystallization of protokimberlite melts which also precipitated sulfides (Pb < 1) and mixed with partial melts from garnet peridotites. Relatively low-Ti ilmenites with high-Cr content (group 3) probably crystallized in the metasomatic front under the rising protokimberlite source and represent the product of crystallization of segregated partial melts from metasomatic rocks. Cr-rich ilmenites are typical of veins and veinlets in peridotites crystallized from highly contaminated magma intruded into wall rocks in different levels within the mantle columns. Ilmenites which have the highest trace element contents (1000/PM) have REE patterns similar to those of perovskites. Low Cr contents suggest relatively closed system fractionation which occurred from the base of the lithosphere up to the garnet-spinel transition, according to monomineral thermobarometry for Mir and Dachnaya pipes. Restricted trends were detected for ilmenites from Udachnaya and most other pipes from the Daldyn-Alakit fields and other regions (Nakyn, Upper Muna and Prianabarie), where ilmenite trends extend from the base of the lithosphere mainly up to 4.0 GPa. Interaction of the megacryst forming melts with the mantle lithosphere caused heating and HFSE metasomatism prior to kimberlite eruption.
DS202006-0926
2020
Salimi, R.Keulen, N., Thomsen, T.B., Schumacher, J.C., Poulsen, M.D., Kalvig, P., Vennemann, T., Salimi, R.Formation, origin and geographic typing of corundum ( ruby and pink sapphire) from the Fiskenaesst complex, Greenland.Lithos, Vol. 366-367, 26p. PdfEurope, Greenlandruby

Abstract: Metamorphic petrology observations on rubies found in-situ in their host-rock are combined with geochemical measurements and optical microscopy observations on the same rubies, with the aim of connecting the ruby-forming metamorphic reaction to a unique fingerprint for these minerals. The Fiskenæsset complex in Greenland is used as an area of this case study. Isochemical pressure-temperature sections were calculated based on electron microprobe and whole-rock geochemistry analyses, and compared to field observations. Rubies formed from reaction between olivine/serpentine and anorthite, triggered by the intrusion of a 2.71 Ga pegmatite. Al is sourced from the anorthite reacting to calcic amphibole, silica from the pegmatite reacts with olivine/serpentine to anthophyllite, Cr3+ is mobile in the pegmatitic fluid, giving colour to the rubies. The ruby-forming reaction occurs at about 640 °C and 7 kbar. In order to establish the unique fingerprint for this ruby-bearing ultramafic complex, laser-ablation inductively-coupled-plasma mass-spectrometry trace-element measurements, oxygen isotope compositions, optical microscopy and scanning electron microscopy were applied. Due to the setting in an ultramafic rock-anorthosite-leucogabbro complex, the fingerprint of the rubies from the Fiskenæsset complex is rather unique. Compared to rubies from other localities, Fiskenæsset complex rubies contain high Cr, intermediate Fe, and low V, Ga, and Ti concentrations, low oxygen isotope values (1.6-4.2‰) and a rarely-observed combination of optical growth features and mineral inclusions like anthophyllite+biotite. Results for other Greenland localities are presented and discussed as well. Even though these are derived from ultramafic rock settings too, they record different trace-element ratios and oxygen isotope values, resulting from variations in the Archaean ruby-forming reaction.
DS202109-1487
2021
Salinkova, E.B.Reguir, E.P., Salinkova, E.B., Yang, P., Chakmouradian, A.R., Stifeeva, M.V., Rass, I.T., Kotov, A.B.U-Pb geochronology of calcite carbonatites and jacupirangite from the Guli alkaline complex, Polar Siberia, Russia.Mineralogical Magazine, Vol. 85, 4, pp. 469-483.Russia, Siberiadeposit - Guli

Abstract: Mantle xenoliths from the Middle-Late Jurassic Obnazhennaya kimberlite are often compared with those from the Udachnaya kimberlite (ca. 367 Ma) to inform the evolution of the Siberia craton. However, there are no direct constraints on the timing of the Obnazhennaya kimberlite eruption. Such uncertainty of the kimberlite age precludes a better understanding of the mantle xenoliths from the Obnazhennaya pipe, and thus also of the evolution of the Siberia craton. This paper reports U-Pb ages for both perovskite from the Obnazhennaya kimberlite and rutile in an Obnazhennaya eclogite xenolith. The fresh perovskite formed during the early stage of magmatic crystallization and yields a U-Pb age of 151.8 ± 2.5 Ma (2?). Rutile in the eclogite xenolith yields an overlapping U-Pb age of 154.2 ± 1.9 Ma (2?). Because rutile has a Pb closure temperature lower than the inferred residence temperature of the eclogite prior to eruption, the U-Pb isotope system in rutile was not closed until the host eclogite was entrained and delivered to the surface by the kimberlite and therefore records the timing of kimberlite eruption. These data provide the first direct constraints on the emplacement age of the Obnazhennaya kimberlite and add to the global ‘kimberlite bloom’ from ca. 250-50 Ma as well as to the largest pulse of kimberlite volcanism in Siberia from ca. 171-144 Ma. The timing of this Jurassic-Cretaceous pulse coincides with the closure of the Mongol-Okhotsk Ocean, but the depleted Sr-Nd isotopic characteristics of 171-144 Ma kimberlites are inconsistent with a subduction-driven model for their petrogenesis. Thus, the closure of the Mongol-Okhotsk Ocean may act as a trigger for the initiation of 171-144 Ma kimberlite emplacement of Siberia, but was not the source.
DS1991-1154
1991
SalisburyMilkereit, B., Percival, J.A., White, D., Green, A.G., SalisburySeismic reflectors in high grade metamorphic rocks of the Kapuskasinguplift: results of preliminary drill site surveysGeodynamics, Vol. 22, pp. 39-45OntarioKapuskasing uplift, Geophysics -seismics
DS2001-0347
2001
SalisburyFunck, T., Louden, Hall, Wardle, Salisbury, ReidSynthesis of the Escoot 1996 refraction seismic studies in the Torngat Orogen.Geological Association of Canada (GAC) Annual Meeting Abstracts, Vol. 26, p.48, abstract.Quebec, Labrador, UngavaGeophysics - seismics, ESCOOT.
DS200712-0066
2005
Salisbury, M.Bellefleur, G., Matthews, L., Roberts,B., McMonnies, B., Salisbury, M., Snyder, D., Perron, G., McGaughty, J.Downhole seismic imaging of the Victor kimberlite, James Bay Lowlands, Ontario: a feasibility study.Geological Survey of Canada Current Research, 2005- C1, 7p.Canada, OntarioGeophysics - seismics
DS1990-0486
1990
Salisbury, M.H.Fountain, D.M., Percival, J., Salisbury, M.H.Exposed cross sections of the continental crust- synopsisExposed cross sections of the Continental Crust, ed. M.H. Salisbury and, pp. 653-662GlobalCrust, Geophysics
DS1990-0487
1990
Salisbury, M.H.Fountain, D.M., Salisbury, M.H., Percival, J.Seismic structure of the continental crust based on rock velocity measurements from the Kapuskasing UpliftJournal of Geophysical Research, Vol. 95, No. B2, February 10, pp. 1167-1186OntarioGeophysics -seismics, Kapuskasing Zone
DS1991-0041
1991
Salisbury, M.H.Atekwana, E.A., Salisbury, M.H.Ramp-flat geometry within the central Kapuskasing structural zone? evidence from potential field modellingGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC)/SEG Annual Meeting May 27-29. Toronto, Ontario, Abstract, Vol. 16, p. A5. AbstractOntarioStructure, Tectonics -LFZ
DS1991-1132
1991
Salisbury, M.H.Mereu, R.F., Percival, J.A., Mareschal, M., Salisbury, M.H.Collaborative special project to identify seismic reflectors in high grade metamorphic rocks of the Kapuskasing UpliftCan. Cont. Drilling Project, August 40pOntarioGeophysics -seismics, Kapuskasing Zone
DS1992-1654
1992
Salisbury, M.H.White, D.J., Milkereit, B., Salisbury, M.H., Percival, J.A.Crystalline lithology across the Kapuskasing Uplift determined using insitu Poisson's ratio from seismic tomography.Journal of Geophysical Research, Vol. 97, No. B13, December 10, pp. 19, 993-20, 006.OntarioGeophysics -seismics, Lithology, Kapuskasing uplift
DS1994-1517
1994
Salisbury, M.H.Salisbury, M.H., Fountain, D.M.The seismic velocity and Poisson's ratio structure of the Kapuskasing uplift from laboratory measurements.Canadian Journal of Earth Sciences, Vol. 31, No. 7, July pp. 1052-1063.OntarioGeophysics -seismics, Tectonics -Kapuskasing uplift
DS1995-1647
1995
Salisbury, M.H.Salisbury, M.H., Christensen, N.I.Olivine fabric in the Bay of Islands ophiolite: implications for oceanic mantle structure, anisotropy.Canadian Journal of Earth Sciences, Vol. 22, pp. 1757-66.NewfoundlandTectonics - structure
DS200512-1164
2005
Salisbury, M.H.Wang, Q., Ji, S., Salisbury, M.H., Xia, B., Pan, M., Xu, Z.Pressure dependence and anisotropy of P wave velocities in ultrahigh pressure metamorphic rocks from the Dabie Sulu orogenic belt: implications for seismic propertiesTectonophysics, Vol. 398, 1-2, pp. 67-99.ChinaMantle reflections, subduction slabs
DS200512-1165
2005
Salisbury, M.H.Wang, Q., Shaocheng, J., Salisbury, M.H., Xia, B., Pan, M., Xu, Z.Shear wave properties and Poisson's ratios of ultrahigh pressure metamorphic rocks from the Dabie Sulu orogenic belt, China: implications for crustal composition.Journal of Geophysical Research, Vol. 110, B8, pp. B08411 10.1029/2004 JB003435Asia, ChinaUHP
DS200612-1506
2005
Salisbury, M.H.Wang, Q., Ji, S., Salisbury, M.H., Xia, B., Pan, M., Xu, Z.Shear wave properties and Poisson's ratios of ultrahigh pressure metamorphic rocks from Dabie Sulu orogenic belt.Journal of Geophysical Research, Vol. 110, B8, BO8208.ChinaUHP
DS200812-0416
2007
Salitykova, A.K.Glebovitsky, V.A., Nikitin, L.P., Salitykova, A.K., Ovchinnikov, N.O., Babushkina, M.S., Egorov, AshchepkovCompositional heterogeneity of the continental lithospheric mantle beneath the Early Precambrian and Phanerozoic structures: evidence from mantle xenoliths.Geochemistry International, Vol. 45, 11, pp. 1077-1102.MantleKimberlites and basalts
DS1989-1167
1989
Salje, E.K.H.Palmer, D.C., Salje, E.K.H., Schmahl, W.W.Phase transitions in leucite: X-ray diffraction studiesPhysics and Chemistry of Minerals, Vol. 16, No. 7, pp. 714-719GlobalLeucite, Mineralogy
DS1993-0774
1993
Salkhi, M.Kaminsky, F.V., Roamnko, Ye.F., Kolesnikov, S.K., Salkhi, M.Lamproites of northern AlgeriaInternational Geology Review, Vol. 35, No. 3, March pp. 235-252AlgeriaLamproites, Review
DS201112-0902
2011
Salknikova, E.B.Salknikova, E.B., Yakoleva, S.Z., Kotov, A.B., Plotkina, Yu.V.TIMS U-Pb dating of bastnasite, calzitite and tantalite as a powerful tool for timing of rare metal granites and carbonatites, (Eastern Siberia).Goldschmidt Conference 2011, abstract p.1785.RussiaGeochronology
DS201705-0810
2016
Salko, D.V.Bornyakov, S.A., Salko, D.V.Instrumental deformation monitoring system and its trial in open pit diamond mine.Journal of Mining Science, Vol. 52, 2, pp. 388-393.RussiaDeposit - Nyurbisnskaya

Abstract: The designed automated system for pitwall deformation monitoring consists of an independent data recorder, strain sensors, AD converters, and front-end and back-end controls. Data are accumulated on server in on-line mode via cellular modem. The self-contained tools are supplied from accumulators recharged by solar batteries, which expands operational life of the system. The system has been trailed in an open pit mine at Nyurbinskaya kimberlite pipe in deformation monitoring of faults in the eastern pitwall and estimation of its stability.
DS201912-2788
2020
Sall, A.E.Hauri, E.H., Cottrell, E., Kelley, K.A., Tucker, J.M., Shimizu, K., Le Voyer, M., Marske, J., Sall, A.E.Carbon in the convecting mantle. IN: Deep carbon: past to present, Orcutt, Daniel, Dasgupta eds., pp. 237-275.Mantlecarbon

Abstract: This chapter provides a summary of the flux of carbon through various oceanic volcanic centers such as mid-ocean ridges and intraplate settings, as well as what these fluxes indicate about the carbon content of the mantle. By reviewing methods used to measure the carbon geochemistry of basalts and then to estimate fluxes, the chapter provides insight into how mantle melting and melt extraction processes are estimated. The chapter discusses how the flux of carbon compares with other incompatible trace elements and gases. From there, the chapter discusses whether the budget of carbon in the ocean mantle can be explained by primordial carbon or whether carbon recycling is required to balance the budget.
DS200712-0927
2007
Sallares, V.Sallares, V., Calahorrano, A.Geophysical characterization of mantle melting anomalies: a crustal view.Plates, plumes and Planetary Processes, pp. 507-524.MantleMelting
DS200912-0659
2009
Salman PartnersSalman PartnersDiamond graph from 1973- 2008 price index for rough diamonds and price in dollars for polished. Brief notation,Salman Partners, Feb. 23, 1/2p.GlobalNews item - diamond prices
DS201312-0774
2013
Salman PartnersSalman PartnersDiamonds - prices The 2103 Commodity price book, p. 31.GlobalDiamond price graph
DS201604-0590
2015
Salmin, R.A.Alexakhin, V.Yu., Bystritsky, V.M., Zamyatin, N.I., Zubarev, E.V., Krasnoperov, A.V., Rapatsky, V.L., Rogov, Yu.N., Sadovsky, A.B., Salamatin, A.V., Salmin, R.A., Sapozhnikov, M.G., Slepnev, V.M., Khabarov, S.V., Razinkov,E.A., Tarasov, O.G., Nikitin,G.M.Detection of diamonds in kimberlite by the tagged neutron method.Nuclear Instruments and Methods in Physics Research Section A., A785, pp. 9-13.TechnologyMethodology

Abstract: A new technology for diamond detection in kimberlite based on the tagged neutron method is proposed. The results of experimental researches on irradiation of kimberlite samples with 14.1-MeV tagged neutrons are discussed. The source of the tagged neutron flux is a portable neutron generator with a built-in 64-pixel silicon alpha-detector with double-sided stripped readout. Characteristic gamma rays resulting from inelastic neutron scattering on nuclei of elements included in the composition of kimberlite are registered by six gamma-detectors based on BGO crystals. The criterion for diamond presence in kimberlite is an increased carbon concentration within a certain volume of the kimberlite sample.
DS201811-2605
2018
Salminen, J.Salminen, J., Hanson, R., Evans, D.A.D., Gong, Z., Larson, T., Walker, O., Gumsley, A., Soderlund, U., Ernst, T.Direct Mesoproterozoic connection of the Congo and Kalahari cratons in proto-Africa: strange attractors across supercontinental cycles.Geology, doi.org/10.1130/G45294.1 4p.Africacraton

Abstract: Mobilistic plate-tectonic interpretation of Precambrian orogens requires that two conjoined crustal blocks may derive from distant portions of the globe. Nonetheless, many proposed Precambrian cratonic juxtapositions are broadly similar to those of younger times (so-called “strange attractors”), raising the specter of bias in their construction. We evaluated the possibility that the Congo and Kalahari cratons (Africa) were joined together prior to their amalgamation along the Damara-Lufilian-Zambezi orogen in Cambrian time by studying diabase dikes of the Huila-Epembe swarm and sills in the southern part of the Congo craton in Angola and in Namibia. We present geologic, U-Pb geochronologic, and paleomagnetic evidence showing that these two cratons were directly juxtaposed at ca. 1.1 Ga, but in a slightly modified relative orientation compared to today. Recurring persistence in cratonic connections, with slight variations from one supercontinent to the next, may signify a style of supercontinental transition similar to the northward motion of Gondwana fragments across the Tethys-Indian oceanic tract, reuniting in Eurasia.
DS201901-0071
2018
Salminen, J.Salminen, J., Oliveira, E.P., Piispa, E.J., Smirnov, A.V., Trindade, R.I.F.Revisiting the paleomagnetism of the Neoarchean Uaua mafic dyke swarm, Brazil: implications for Archean supercratons.Precambrian Research, doi.org/10.1016/j. precamres.2018.12.001 17p. South America, Brazilcraton

Abstract: The original connections of Archean cratons are becoming traceable due to an increasing amount of paleomagnetic data and refined magmatic barcodes. The Uauá block of the northern São Francisco craton may represent a fragment of a major Archean craton. Here, we report new paleomagnetic data from the 2.62 Ga Uauá tholeiitic mafic dyke swarm of the Uauá block in the northern São Francisco craton, Eastern Brazil. Our paleomagnetic results confirm the earlier results for these units, but our interpretation differs. We suggest that the obtained characteristic remanent magnetization for the 2.62 Ga swarm is of primary origin, supported by a provisionally-positive baked contact test. The corresponding paleomagnetic pole (25.2°N, 330.5°E, A95 = 8.1° N = 20) takes the present northern part of the São Francisco craton to moderate latitudes. Based on the comparison of the paleolatitudes of cratons with high-quality paleomagnetic data and magmatic barcodes, we suggest that the northern part of the São Francisco craton could have been part of the proposed Supervaalbara supercraton during the Archean. Supervaalbara is proposed as including (but not limited to) the part of the São Francisco craton as well as the Superior, Wyoming, Kola + Karelia, Zimbabwe, Kaapvaal, Tanzania, Yilgarn, and Pilbara cratons.
DS201902-0316
2019
Salminen, J.Salminen, J., Hanson, R., Evans, D.A.D., Gong, Z., Larson, T., Walker, O., Gumsley, A., Soderlund, U., Ernst, R.Direct Mesoproterozoic connection of the Congo and Kalahari cratons in proto-Africa: strange attractors across supercontinental cycles.Geology, Vol. 46, pp. 1101-1104.Africa, Angola, Namibiacraton

Abstract: Mobilistic plate-tectonic interpretation of Precambrian orogens requires that two conjoined crustal blocks may derive from distant portions of the globe. Nonetheless, many proposed Precambrian cratonic juxtapositions are broadly similar to those of younger times (so-called “strange attractors”), raising the specter of bias in their construction. We evaluated the possibility that the Congo and Kalahari cratons (Africa) were joined together prior to their amalgamation along the Damara-Lufilian-Zambezi orogen in Cambrian time by studying diabase dikes of the Huila-Epembe swarm and sills in the southern part of the Congo craton in Angola and in Namibia. We present geologic, U-Pb geochronologic, and paleomagnetic evidence showing that these two cratons were directly juxtaposed at ca. 1.1 Ga, but in a slightly modified relative orientation compared to today. Recurring persistence in cratonic connections, with slight variations from one supercontinent to the next, may signify a style of supercontinental transition similar to the northward motion of Gondwana fragments across the Tethys-Indian oceanic tract, reuniting in Eurasia.
DS201606-1084
2016
Salminen, J.M.Evans, D.A.D., Trindade, R.I.F., Catelani, E.L., D'Agrella-Filho, Heaman, L.M., Oliveira, E.P., Soderlund, U., Ernst, R.E., Smirnovm A.V., Salminen, J.M.Return to Rodinia? Moderate to high paleolatitude of the Sao Francisco/Congo craton at 920 Ma.Geological Society of London Special Publication Supercontinent Cycles through Earth History., Vol. 424, pp. 167-190.South America, BrazilSupercontinents

Abstract: Moderate to high palaeolatitudes recorded in mafic dykes, exposed along the coast of Bahia, Brazil, are partly responsible for some interpretations that the São Francisco/Congo craton was separate from the low-latitude Rodinia supercontinent at about 1050 Ma. We report new palaeomagnetic data that replicate the previous results. However, we obtain substantially younger U-Pb baddeleyite ages from five dykes previously thought to be 1.02- 1.01 Ga according to the 40 Ar/ 39 Ar method. Specifically, the so-called 'A-normal' remanence direction from Salva-dor is dated at 924.2 + 3.8 Ma, within error of the age for the 'C' remanence direction at 921.5 + 4.3 Ma. An 'A-normal' dyke at Ilhéus is dated at 926.1 + 4.6 Ma, and two 'A-normal' dykes at Olivença have indistinguishable ages with best estimate of emplacement at 918.2 + 6.7 Ma. We attribute the palaeomagnetic variance of the 'A-normal' and 'C' directions to lack of averaging of geomagnetic palaeosecular variation in some regions. Our results render previous 40 Ar/ 39 Ar ages from the dykes suspect, leaving late Mesoproterozoic palaeolatitudes of the São Francisco/Congo craton unconstrained. The combined 'A-normal' palaeomagnetic pole from coastal Bahia places the São Francisco/Congo craton in moderate to high palaeolatitudes at c. 920 Ma, allowing various possible positions of that block within Rodinia. Despite more than two decades of intense global research, the configuration of Neoproterozoic supercontinent Rodinia remains enigmatic. Following the first global synthesis by Hoffman (1991), most models include a central location for Laurentia, flanked by 'East' Gondwana-Land cra-tons along its proto-Cordilleran margin and 'West'
DS1992-0827
1992
Salminien, R.Kauranne, L.K., Salminien, R., Eriksson, K.Regolith exploration geochemistry in Arctic and temperate terrainsElsevier, in prepArcticGeochemistry, Weathering
DS1999-0777
1999
Salmirinne, H.Vuvollo, J.I., Salmirinne, H.The Eastern Fennoscandian mafic dyke swarms GIS database - a tool for integrated geoscientific studies.Geological Association of Canada (GAC) Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC)., Vol. 24, p. 133. abstractFinland, Russia, Kola PeninsulaDike swarm
DS2002-1388
2002
Salmon, H.M.Salmon, H.M.Further tales from the Gardar: a REE perspective18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.251.GreenlandTectonics
DS201312-0734
2014
Salmon, M.Rawlinson, N., Salmon, M., Kennett, B.L.N.Transportable seismic array tomography in southeast Australia: illuminating the transition from Proterozoic to Phanerozoic lithosphere.Lithos, Vol. 189, pp. 65-76.AustraliaGeophysics - seismics
DS1998-1278
1998
Salmon, R.L.Salmon, R.L.Lectures on geophysical fluid dynamicsOxford University of Press, 416p. $ 80.00GlobalBook - ad, Geophysical fluid dynamics
DS201312-0334
2013
Salnikov, E.B.Griban, J.G., Samsonov, A.V., Salnikov, E.B., Lepehina, E.N.Kimberlitic zircons from the Paleoproterozoic Kimzero kimberlites ( Karelia): mineralogy, geochemistry and U-Pb geochronology.Goldschmidt 2013, AbstractRussia, KareliaDeposit - Kimozero
DS2001-0265
2001
SalnikovaDonskaya, T.V., Salnikova, Sklyarov, GladkochubEarly Proterozoic Post collision magmatism at the southern flank of the Siberian Craton: geochronological...Doklady, Vol.383, No. 1-2, Feb-Mar. pp. 125-8.Russia, SiberiaGeodynamic - magmatism, Geochronology
DS200612-0740
2006
SalnikovaKovalenko, V.I., Yarmolyuk, Salnikova, Kozlovski, Kotov, Kovach, Vladykin, Savatenkov, V.M., Ponomarchuk, V.A.Geology and age of Khan-Bogdinsky massif of alkaline granitoids in southern Mongolia.Vladykin: VI International Workshop, held Mirny, Deep seated magmatism, its sources and plumes, pp. 17-45.Asia, MongoliaAlkaline rocks, granites
DS200712-1117
2007
SalnikovaVernikovskaya, I.V., Salnikova, Matushkin, YasnevThe Neoproterozoic alkaline rocks of the Yenisey Ridge, western margin of the Siberian Craton: mineralogy, geochemistry and geochronology.Plates, Plumes, and Paradigms, 1p. abstract p. A1065.RussiaIjolite
DS201212-0158
2012
SalnikovaDegtyarev, K.E., Tretyakov, Kotov, Salnikova, Shatagi, Yakovleva, Anismova, PlotkinaThe Chelkar peridotite-gabbronorite pluton ( Kokchetav massif, northern Kazakhstan): formation type and geochronology.Doklady Earth Sciences, Vol. 446, 2, pp. 1162-1166.Russia, KazakhstanGeochronlogy
DS201312-0512
2013
Salnikova, E.Kovach, V.,Salnikova, E., Wang, K-L., Jahn, B-M., Chiu, H-Y., Reznitskiy, L., Kotov, A., Lizuka, Y., Chung, S-L.Zircon ages and Hf isotopic constraints on sources of clastic metasediments of the Slyudyansky high grade complex, southeastern Siberia: implication for continental growth and evolution of the Central Asian orogenic belt.Journal of Asian Earth Sciences, Vol. 62, pp. 18-36.Russia, SiberiaUHP, Geochronology
DS201412-0473
2014
Salnikova, E.Korikovsky, S., Kotov, A., Salnikova, E., Aranovich, L., Korpechkov, D., Yakovleva, S., Tolmacheva, E., Anisimova, I.The age of the protolith of metamorphic rocks in the southeastern Lapland granulite belt, southern Kola Peninsula: correlation with the Belomorian mobile belt in the context of the problem of Archean eclogites.Petrology, Vol. 22, 2, pp. 91-108.Russia, Kola PeninsulaEclogite
DS200512-0626
2004
Salnikova, E.B.Levitskii, V.I., Salnikova, E.B., Kotov, A.B., Reznitskii, L.Z., Barash, I.G., et al.Age of formation of apocarbonate metasomites of the Sharyzhalgai Uplift of the Siberian Craton basement, southwestern Baikal region U - Pb baddeleyite, zirconDoklady Earth Sciences, Vol. 399A, 9, Nov-Dec. pp. 1204-1208.Russia, SiberiaGeochronology
DS200612-0189
2006
Salnikova, E.B.Buchko, I.V., Salnikova, E.B., Kotov, A.B., Larin, A.M., Velikoslavinskii, Sorokin, Sorokin, YakovlevaPaleoproterozoic gabbro anorthosites of the Selenga Superterrane, southern framing of the Siberian Craton.Doklady Earth Sciences, Vol. 407, 3, pp. 372-375.Russia, SiberiaTectonics
DS200612-1566
2005
Salnikova, E.B.Yarmolyuk, V.V., Kovalenko, V.I., Salnikova, E.B., Nijiforov, A.V., Lotov, A.B., Vladykin, N.V.Late Riphean rifting and breakup of Laurasia: dat a on geochronological studies of ultramafic alkaline complexes in the southern framing of the Siberian Craton.Doklady Earth Sciences, Vol. 404, 7, pp. 1031-1036.RussiaTectonics, geochronology
DS201412-0952
2014
Salnikova, E.B.Vladykin, N.V., Kotov, A.B., Borisenko, A.S., Yarmolyuk, V.V., Pokhilenko, N.P., Salnikova, E.B., Travin, A.V., Yakovleva, S.Z.Age boundaries of formation of the Tomtor alkaline ultramafic pluton: U Pb and 40 Ar 39 Ar geochronological studies.Doklady Earth Sciences, Vol. 454, 1, pp. 7-11.RussiaGeochronology
DS201412-0953
2014
Salnikova, E.B.Vladykin, N.V., Sotnikov, I.A., Kotov, A.B., Yarmolyuk, V.V., Salnikova, E.B., Yakovleva, S.Z.Structure, age and ore potential of the Burpala rare-metal alkaline Massif, northern Baikal region.Geology of Ore Deposits, Vol. 56, 4, pp. 239-256.RussiaAlkalic
DS201709-2050
2017
Salnikova, E.B.Salnikova, E.B., Chakhmouradian, A.R., Stifeeva, M.V., Reguir, E.P., Nikiforov, A.V.Calcic garnets as a promising U-Pb geochronometers. Kola PeninsulaGoldschmidt Conference, abstract 1p.Russiacarbonatite, Belyaya Zima

Abstract: Calcic garnets are an important – although somewhat neglected – member of the garnet group. Typically, these mineral are members of complex solid solutions involving largely substitutions in the Fe3+/Al and Si sites and at least eight different end-members. The absolute majority of garnets in this family are Ti-Mg-Fe2+(± Al ± Zr)-bearing andradite transitional to morimotoite and schorlomite. Importantly, these garnets occur as common accessory minerals in a wide range of igneous and rocks, including nepheline syenites, alkali feldspar syenites, melteigite-urtites, nephelinites, melilitolites, melilitites, calcite carbonatites, ultramafic lamprophyres, orangeites, contaminated kimberlites, skarns and rodingites. Calcic garnets have a great capacity for atomic substitutions involving high-field-strength elements and, even more importantly, rare earths (up to 4000 ppm, including Y), Th and U (both up to 100 ppm) at low levels of common Pb. Their (La/Yb)cn ratio varies over two orders of magnitude (from < 0.01 to ~1), making these minerals a sensitive indicator of crystal fractionation, degassing and other magma-evolution processes. Given these unique compositional characteristics and surprising lack of interest in these minerals in the previous literature, we explored the possibility of using calcic garnets as a U-Pb geochronometer. For this purpose, we selected samples of well-crystallized igneous garnet from four very different rock types of different age, including: carbonatite (Afrikanda) from the Devonian Kola Alkaline Province, carbonatite from the Neoproterozoic Belaya Zima complex (Central-Asian mobile belt), ijolite from the Chick Ordovician igneous complex (Central-Asian mobile belt), granitic pegmatite from the Eden Lake complex in the Paleoproterozoic Trans-Hudson orogen, and feldspathoid syenite from the Cinder Lake alkaline complex in the Archean Knee Lake greenstone belt. U-Pb TIMS ages of the studied garnets are mostly concordant and reveal perfect correspondence with reported U-Pb zircon or perovskite ages as well as Sm-Nd isochrone age for these complexes. Therefore we can advertise calcic garnets as a promising tool for U-Pb geochronological studies.
DS201712-2686
2017
Salnikova, E.B.Gladkochub, D.P., Donskaya, T.V., Sklyarov, E.V., Kotov, A.B., Vladykin, N.V., Pisarevsky, S.A., Larin, A.M., Salnikova, E.B., Saveleva, V.B., Sharygin, V.V., Starikova, A.E., Tolmacheva, E.V., Velikoslavinsky, S.D., Mazukabzov, A.M., Bazarova, E.P., KovaThe unique Katugin rare metal deposit ( southern Siberia): constraints on age and genesis.Ore Geology Reviews, in press available, 18p.Russia, Siberiadeposit - Katugin

Abstract: We report new geological, mineralogical, geochemical and geochronological data about the Katugin Ta-Nb-Y-Zr (REE) deposit, which is located in the Kalar Ridge of Eastern Siberia (the southern part of the Siberian Craton). All these data support a magmatic origin of the Katugin rare-metal deposit rather than the previously proposed metasomatic fault-related origin. Our research has proved the genetic relation between ores of the Katugin deposit and granites of the Katugin complex. We have studied granites of the eastern segment of the Eastern Katugin massif, including arfvedsonite, aegirine-arfvedsonite and aegirine granites. These granites belong to the peralkaline type. They are characterized by high alkali content (up to 11.8?wt% Na2O?+?K2O), extremely high iron content (FeO?/(FeO??+?MgO)?=?0.96-1.00), very high content of most incompatible elements - Rb, Y, Zr, Hf, Ta, Nb, Th, U, REEs (except for Eu) and F, and low concentrations of CaO, MgO, P2O5, Ba, and Sr. They demonstrate negative and CHUR-close ?Nd(t) values of 0.0…?1.9. We suggest that basaltic magmas of OIB type (possibly with some the crustal contamination) represent a dominant part of the granitic source. Moreover, the fluorine-enriched fluid phases could provide an additional source of the fluorine. We conclude that most of the mineralization of the Katugin ore deposit occurred during the magmatic stage of the alkaline granitic source melt. The results of detailed mineralogical studies suggest three major types of ores in the Katugin deposit: Zr mineralization, Ta-Nb-REE mineralization and aluminum fluoride mineralization. Most of the ore minerals crystallized from the silicate melt during the magmatic stage. The accessory cryolites in granites crystallized from the magmatic silicate melt enriched in fluorine. However, cryolites in large veins and lens-like bodies crystallized in the latest stage from the fluorine enriched melt. The zircons from the ores in the aegirine-arfvedsonite granite have been dated at 2055?±?7?Ma. This age is close to the previously published 2066?±?6?Ma zircon age of the aegirine-arfvedsonite granites, suggesting that the formation of the Katugin rare-metal deposit is genetically related to the formation of peralkaline granites. We conclude that Katugin rare-metal granites are anorogenic. They can be related to a Paleoproterozoic (?2.05?Ga) mantle plume. As there is no evidence of the 2.05?Ga mantle plume in other areas of southern Siberia, we suggest that the Katugin mineralization occurred on the distant allochtonous terrane, which has been accreted to Siberian Craton later.
DS202007-1177
2020
Salnikova, E.B.Salnikova, E.B., Samsonov, A.V., Stepanova, A.V., Veselovskiy, R.V., Egorova, S.V., Arzamastsev, A.A., Erofeeva, K.G.Fragments of Paleoproterozoic large igneous provinces in northern Fennoscandia: baddeleyite U-Pb age data for mafic dykes and sills.Doklady Earth Sciences, Vol. 491, pp. 227-230.Europe, Russia, Kola Peninsulageochronology

Abstract: New data on the age of dolerite dikes in the NE part of the Kola province of the Fennoscandinavian shield and the picrodolerite sills that cut the dikes are presented. The results of U-Pb ID-TIMS baddeleyite dating indicate that dolerites were formed between 2508 ± 6 and 2513 ± 16 Ma ago, simultaneously with the intrusions of the Monchegorsk group. A comparison of the composition of the dolerites studied with dykes of the same age found in other Archean cratons shows their significant similarity and suggests their formation at the same large magmatic province. The age of baddeleyite from the picrodolerites sills at 2403 ± 12 Ma ago indicates an event of basic magmatism that was not previously established in this part of the Fennoscandinavian shield. It is possible that, along with dolerite dykes with an age of 2405 Ma and komatiites of the Vetreny belt of the Karelian craton, sills of the Kola province are a component of a unified large magmatic event.
DS1995-1348
1995
Salnikova, Ye.Neymark, L.A., Nemchin, A.A., Vetrin, V., Salnikova, Ye.samarium-neodymium (Sm-Nd) and lead lead isotope systems in lower crustal xenoliths from dikes and pipes in southern Kola pen.Doklady Academy of Sciences, Vol. 329A, No. 3, April, pp. 214-221.Russia, Kola PeninsulaXenoliths, Geochronology
DS202102-0194
2021
Salnikova E.B.Gladkochub, D.P., Donskaya, T.V., Pisarevesky, S.A., Salnikova E.B., Mazukabzov, A.M., Kotov, A.B., Motova, Z.I., Stepanova, A.V., Kovach, V.P.Evidence of the latest Paleoproterozoic ( ~1615 Ma) mafic magmatism the southern Siberia: extensional environments in Nuna subcontinent.Precambrian Research, Vol. 354, doi.org/10.1016 /j.precamres. 2020.10049 14p. PdfRussiaCraton - Siberian
DS1990-1217
1990
Salo, S.Rasanen, M.E., Salo, S., Jungnert, H., Pittman, L.R.Evolution of the Western Amazon Lowland relief: impact of Andean forelanddynamicsTerra Nova, Vol. 2, pp. 320-332Brazil, AndesTectonics, Geomorphology
DS201501-0028
2014
Salomon, E.Salomon, E., Koehn, D., Passchier, C.Brittle reactivation of ductile shear zones in NW Namibia in relation to South Atlantic rifting. Tectonics, Vol. 34, pp. 70-85.Africa, NamibiaTectonics
DS1995-1648
1995
Salomons, W.Salomons, W., Forstner, U., Mader, P.Heavy metals... problems and solutionsSpringer, 270p. approx. $ 110.00GlobalBook -ad, Environment -heavy metals
DS1989-0151
1989
Salonen, V.P.Bouchard, M.A., Salonen, V.P.Glacial dispersal of boulders in the James Bay Lowlands of Quebec, SOURCE[ BoreasBoreas, Vol. 18, No. 3, pp. 189-200QuebecGeomorphology, James Bay area
DS1985-0582
1985
Salpas, P.A.Salpas, P.A., Taylor, L.A., Shervais, J.W.Blueball, a New Kimberlite from ArkansawGeological Society of America (GSA), Vol. 17, No. 7, P. 705. (abstract.).United States, Gulf Coast, Arkansas, TennesseeGeochemistry, Petrography, Mineral Chemistry
DS1986-0701
1986
Salpas, P.A.Salpas, P.A., Taylor, L.A.Glimmerites: derivative products of kimberlite fractionationGeological Society of America (GSA) Abstract Volume, Vol. 18, No. 6, p. 738. (abstract.)GlobalMantle genesis
DS1986-0702
1986
Salpas, P.A.Salpas, P.A., Taylor, L.A., Shervais, J.W.The Blue Ball Arkansaw kimberlite: mineralogy, petrology andgeochemistryJournal of Geology, Vol. 94, No. 6, November pp. 891-901ArkansasGeochrmistry, Mineralogy, Petrology
DS1989-1326
1989
Salter, J.D.Salter, J.D., Nordin, L., Downing, B.J.Kimberlite-gabbro sorting by use of microwave attentuation: development from the laboratory to a 100 t/h pilot plantInstitute of Mining and Metallurgy (IMM) Proceedings of MMIJ Today's technology for the mining and metalurgical, pp. 347-358GlobalMineral processing, Kimberlite
DS1990-1294
1990
Salter, J.D.Salter, J.D., Downing, B.J., Rix, G.M., Marais, M.G.Development of rock pass level monitors for Finsch diamond mine, SouthAfrica14th. Cmmi Congress Held Edinburgh, Scotland July 2-6, 1990 Institute Of Mining And Metallurgy (imm) Proceedings, pp. 107-111South AfricaMining, Finsch mine
DS1993-1370
1993
Salter, J.D.Salter, J.D., Nordin, L., Downing, B.J.Kimberlite-gabbro sorting use of microwave attenuation:development laboratory -100 t/h pilot plantUnknown, pp. 347-358.South AfricaMineral processing, Deposit -Premier
DS2000-0037
2000
SaltersAshchepkov, V., Salters, Ionov, Litasov, Travin, StrizhovGeochemistry of lherzolite and pyroxenites mantle inclusions from different stages of development VitiM.Igc 30th. Brasil, Aug. abstract only 1p.RussiaMetasomatism, Vitim Volcanic plateau
DS2003-0115
2003
Salters, V.J.Bizimis, M., Salters, V.J., Dawson, J.B.The brevity of carbonatite sources in the mantle: evidence from Hf isotopesContributions to Mineralogy and Petrology, Vol. 145, 3, pp. 281-300.MantleGeochronology
DS200612-1209
2006
Salters, V.J.Salters, V.J., Blichert Toft, V.J., Fekiacova, J., Sachikocher, A., Bizimis, M.Isotope and trace element evidence for depleted lithosphere in the source of enriched Kolau basalts.Contributions to Mineralogy and Petrology, Vol. 151, 3, pp. 297-312.RussiaGeochronology
DS200912-0762
2008
Salters, V.J.Tibbetts, N.J., Bzimis, M., Salters, V.J., Rudnick, R.L.The Hf Nd systematics of rutile bearing eclogites from Koidu, Sierra Leone.American Geological Union, Fall meeting Dec. 15-19, Eos Trans. Vol. 89, no. 53, meeting supplement, 1p. abstractAfrica, Sierra LeoneSubduction chemistry
DS1985-0583
1985
Salters, V.J.M.Salters, V.J.M., Barton, M.The Geochemistry of Ultrapotassic Lavas from the Leucite Hills, Wyoming.Eos, Vol. 66, No. 46, NOVEMBER 12, P. 1109. (abstract.).United States, Colorado Plateau, Leucite HillsGeochemistry
DS1988-0606
1988
Salters, V.J.M.Salters, V.J.M., Shimizu, N.HFSE depletions in peridotites, local variations and possible originV.m. Goldschmidt Conference, Program And Abstract Volume, Held May, p. 71. AbstractNew MexicoKilbourne Hole
DS1989-1327
1989
Salters, V.J.M.Salters, V.J.M., Hart, S.R.The hafnium paradox and the role of garnet in the source of mid ocean ridgebasalts.Nature, Vol. 342, Nov. 23, pp. 420-22.MantleMid Ocean Ridge Basalt (MORB) - basalts, geochemistry
DS1992-1321
1992
Salters, V.J.M.Salters, V.J.M., Zindler, A.Hafnium and neodynium isotopes in mantle xenolithsGeological Society of America (GSA) Abstracts with programs, 1992 Annual, Vol. 24, No. 7, abstract p. A84MantleGeochronology, Xenoliths
DS1992-1752
1992
Salters, V.J.M.Zindler, A., Salters, V.J.M.Hafnium -isotopic composition of peridotites and ocean island basalts:implications for the structure of the mantle.Eos, Transactions, Annual Fall Meeting Abstracts, Vol. 73, No. 43, October 27, abstracts p. 655.MantleBasalts, Geochronology
DS1998-1279
1998
Salters, V.J.M.Salters, V.J.M.Hafnium isotope constraints on mantle evolutionChemical Geology, Vol. 145, No. 3-4, Apr. 15, pp. 447-460.MantleGeochemistry, Geochronology
DS2003-0116
2003
Salters, V.J.M.Bizimis, M., Salters, V.J.M., Dawson, J.B.The brevity pf carbonatite sources in the mantle: evidence from Hf isotopesContributions to Mineralogy and Petrology, Vol. 145, 3, June pp. 282-300.MantleCarbonatite, Geochronology
DS200412-0158
2003
Salters, V.J.M.Bizimis, M., Salters, V.J.M., Dawson, J.B.The brevity pf carbonatite sources in the mantle: evidence from Hf isotopes.Contributions to Mineralogy and Petrology, Vol. 145, 3, June pp. 282-300.MantleCarbonatite, Geochronology
DS200512-0471
2005
Salters, V.J.M.Jacob, D.E., Bizimis, M., Salters, V.J.M.Lu Hf and geochemical systematics of recycled ancient oceanic crust: evidence from Roberts Victor eclogites.Contributions to Mineralogy and Petrology, Vol. 148, 6, pp. 707-720.Africa, South AfricaGeochemistry
DS200612-1210
2006
Salters, V.J.M.Salters, V.J.M., Bizimis, M.Recycled depleted lithosphere in the enriched mantle?Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.MantleGeochemistry - REE
DS202008-1459
2020
Salters, V.J.M.Yang, S., Humayaun, M., Salters, V.J.M.Elemental constrains on the amount of recycled crust in the generation of mid-ocean basalts.Science Advances, https://phys.org/ news/2020-06- geochemists- mystery-earth-crust .htmlMantlegeochemistry

Abstract: Mid-oceanic ridge basalts (MORBs) are depleted in incompatible elements, but ridge segments far from mantle plumes frequently erupt chemically enriched MORBs (E-MORBs). Two major explanations of E-MORBs are that these basalts are generated by the melting of entrained recycled crust (pyroxenite) beneath ridges or by the melting of refertilized peridotites. These two hypotheses can be discriminated with compatible element abundances from Sc to Ge, here termed the ScGe elements. Here, we demonstrate that E-MORBs have systematically lower Ge/Si and Sc contents and slightly higher Fe/Mn and Nb/Ta ratios than depleted MORBs (D-MORBs) due to the mixing of low-degree pyroxenite melts. The Ge/Si ratio is a new tracer that effectively discriminates between melts derived from peridotite sources and melts derived from mixed pyroxenite-peridotite sources. These new data are used to estimate the distribution of pyroxenite in the mantle sources of global MORB segments.
DS1998-0052
1998
Salters, V.J.R.Ashchepkov, I.V., Salters, V.J.R., Andre, L.Relationships between garnet and clinopyroxene in Vitim mantle xenoliths:evidence of polystage growth and melt7th International Kimberlite Conference Abstract, pp. 35-36.RussiaXenoliths - lherzolites, Geochemistry
DS1860-0768
1892
Salter-Whiter, J.Salter-Whiter, J.A Trip to South AfricaSurrey: William Pile., Africa, South AfricaTravelogue
DS1999-0623
1999
Saltis, A.R.Saltis, A.R.The Jericho project: an underground bulk sample, northwest Territories, CanadaMining in the Arctic, Udd and Keen editors, Balkema, pp. 165-175.Northwest TerritoriesMining - bulk sampling, Deposit - Jericho
DS200812-1287
2008
Salto, I.Yamaguchi, H., Salto, I., Kudi, Y., Masuzawa, T., Yamada, T., Kudo, M., Takakuma, Y., Okano, K.Electron emission mechanism of hydrogeneated natural type IIb diamond (111).Diamond and Related Materials, Vol. 17, 2, pp. 162-166.TechnologyType II diamonds
DS1992-0862
1992
Salto, S.Kimato, M., Shimizu, M., Salto, S.High temperature crystal structure of melilite: II, akermanite, CasMgSi2O7Geological Association of Canada (GAC) Abstracts Volume, Vol. 17, p. A57. abstract onlyGlobalMelilite, Mineralogy
DS1993-1371
1993
Saltus, R.W.Saltus, R.W., Blakely, R.J.HYPERMAG: an interactive 2 and 1 1/2 dimensional gravity and magnetic modeling program, version 3.5United States Geological Survey (USGS) Open file, No. 93-0287, 39p. $ 6.00GlobalComputer, Program -HYPERMAG
DS1995-1649
1995
Saltus, R.W.Saltus, R.W., Thompson, G.A.Why is it downhill from Tonopah to Las Vegas? a case for mantle plume support of the high N. Basin and RangeTectonics, Vol. 14, No. 6, Dec. pp. 1235-44NevadaTectonics, Basin and Range, plumes
DS1997-0321
1997
SaltykovErinchek, Yu.M., Milshtein, E.D., Kolesnik, N., SaltykovThe deep structure of Diamondiferous kimberlite areas of SiberiaPapumem: 4th. Biennial SGA Meeting, pp. 763-766.Russia, SiberiaDiamond exploration, Platform, Tectonics, Rifting, Structure
DS1998-0399
1998
SaltykovErinchek, Yu.M., Milshtein, E.D., Saltykov, VerzhakLocal depressions in country rock of kimberlites as a new explorationcriteria: Zolotitsa field.7th International Kimberlite Conference Abstract, pp. 208-10.Russia, YakutiaStructure - Vendian, Deposit - Zolotitsa
DS2001-0300
2001
SaltykovErinchek, Y.M., Milshtein, E.D., Saltykov, RykhlovaStructural control of kimberlite pipes in the Zolotitsa cluster ( Arkangelsk diamond field).Mineral deposits 21st. century, pp. 951-4.Russia, ArkangelskTectonics, Deposit - Zolotitsa
DS1998-1280
1998
Saltykov, O. G.Saltykov, O. G., Erinchek, Yu.M., Milshtein, E.D.The model of buried kimberlite field based on reflection in postkimberlite reservoir rocks.7th. Kimberlite Conference abstract, pp. 760-2.Russia, YakutiaStratigraphy, Tectonics, structure, lithology
DS1991-1492
1991
Saltykov, O.G.Saltykov, O.G., Erinchek, Y.M.Mechanism of the formation of buried high contrast haloes of diamond satellite minerals on local paleo-heights.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 320, No. 1, pp. 169-173RussiaIndicator minerals
DS1992-1322
1992
Saltykov, O.G.Saltykov, O.G., Erinchek, V.M.Model manifestation kimberlite field in terrigenous intermediate collectors of diamond satellite minerals.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 326, No. 1, pp. 154-158.RussiaIndicator minerals, Model
DS1994-1518
1994
Saltykov, O.G.Saltykov, O.G., Erinchek, Yu.M.A model for the occurrence of a kimberlite field in terrigenous intermediate collectors of indicators.Doklady Academy of Sciences USSR, Vol. 327A, Nov. pp. 59-63.Russia, YakutiaDiamond, kimberlite genesis, Indicator minerals, geochemistry
DS1995-1650
1995
Saltykov, O.G.Saltykov, O.G.Prediction and prospecting for buried diamond deposits on the basis of specialized paleogeographic investig.Mineral Resources of Russia, abstract, Oct. 1994, pp. 32-36.RussiaPaleogeography, Geomorphology
DS1998-0398
1998
Saltykov, O.G.Erinchek, Y.M., Milshstein, E.D., Saltykov, O.G.The structure of the Middle Paleozoic Vilyui Markha dike belt, SiberianPlatformDoklady Academy of Sciences, Vol. 359, No. 2, pp. 241-4.Russia, SiberiaCraton, Dikes
DS2003-1208
2003
Saltykov, O.G.Saltykov, O.G., Erinchek, Y.M.Prospects for discovery of Middle Paleozoic kimberlites in the south of the SiberianRussian Geology and Geophysics, Vol. 44, No. 3, pp. 240-251Siberiasouthern Siberian platform, pyrope, paleogeography
DS1996-1248
1996
Saltykov. O.G.Saltykov. O.G., Erinchek, Yu.M.Siberian platform middle Paleozoic kimberlite mineral aureolesDoklady Academy of Sciences, Vol. 345A No. 9, October pp. 362-368.Russia, SiberiaGeochemistry - indicators
DS200712-0364
2007
Saltykova, A.K.Glebovitskii, V.A., Nikitina, L.P., Saltykova, A.K., Pushkarev, Y.D., Ovchinnikov, Babushkina, AshchepkovThermal and chemical heterogeneity of the upper mantle beneath the Baikal Mongolia territory.Petrology, Vol. 15, 1, pp. 58-89.RussiaGeothermometry
DS200712-0928
2007
Saltykova, A.K.Saltykova, A.K., Nikitina, L.P., Matukov, D.I.U Pb age and REE dat a (SHRIMP II) on zircons in mantle xenoliths from alkaline basalts ( Vitim area, Transbaikalia): implications for upper mantle partial..Plates, Plumes, and Paradigms, 1p. abstract p. A870.MantleMelting
DS200912-0256
2008
Saltykova, A.K.Goncharov, A.G., Saltykova, A.K.Iron valency in minerals of xenoliths and redox state of the upper mantle by Mossbauer spectroscopy data.Hyperfine Interactions, Vol. 186, 1-3, pp. 187-192.MantleMineralogy
DS201212-0522
2012
Saltykova, A.K.Nikitina, L.P., Marin, Y.B, Skublov, S.G., Korolev, N.M., Saltykova, A.K., et al.U Pb age and geochemistry of zircon from mantle xenoliths of the Katoka and Kat- 115 kimberlitic pipes ( Republic of Angola).Doklady Earth Sciences, Vol. 445, 1, pp. 840-844.Africa, AngolaDeposit - Katoka (Catoca) Kat-115
DS202204-0524
2022
Saltykova, V.P.Kedrova, T.V., Bogush, I.N., Zinchuk, N.N., Bardukhinov, L.D., Lipashova, A.N., Saltykova, V.P.Diamond placers of the Nakyn kimberlite field.Russian Geology and Geophysics, Vol. 63, 3, pp. 245-254.Russiadeposit - Nakyn

Abstract: The paper presents the results of studies of diamonds from Early Jurassic sediments making up the Nyurbinskoe buried placer of the Nakyn kimberlite field, unique in diamond reserves. The main task is to identify diamond distribution patterns in the deposits of the Dyakhtar Stratum (lower deposit) and the Ukugut Suite (upper deposit) within the placer. A comparative analysis of the typomorphic features of diamonds from the upper and lower deposits of the placer was carried out. Variations in the contents of crystals with certain properties that form the image of a diamond-bearing geologic object have been revealed. The zonal distribution of diamonds by characteristics in sedimentary deposits, regardless of their age, has been established. The properties of diamonds and their associations change within the placer, which is due to their redeposition during the Early Jurassic sedimentation.
DS1992-1069
1992
Saltykovski, A.Ye.Milyutkin, S.A., Genshaft, Yu.S., Saltykovski, A.Ye., KuznetsovaPhysical characteristics of megacrystal high pressure phasesJournal of Geodynamics, Vol. 15, No. 3-4, pp. 169-184.GlobalKimberlite
DS1983-0248
1983
Saltykovskiy, A.YA.Genshaft, YU.S., Saltykovskiy, A.YA., Vayner, D.I.Crystallization of minerals of the eclogite paragenesis at pressures of 35to 50 kbarDoklady Academy of Science USSR, Earth Science Section, Vol. 273, Nov.-Dec. pp. 115-118RussiaXenoliths, Eclogite
DS1984-0297
1984
Saltykovskiy, A.YA.Genshaft, YU.S., Saltykovskiy, A.YA., Vayner, D.I.Generation of potassic mantle magma as inferred from experimental petrologic dataDoklady Academy of Science USSR, Earth Science Section, Vol. 275, March-April pp. 53-55RussiaGenesis, Eclogite
DS1987-0245
1987
Saltykovskiy, A.Ya.Genshaft, Yu.S., Saltykovskiy, A.Ya.Kimberlite type inclusions in alkalic basalts of the Dariganga plateau, MOngolian People's RepublicDoklady Academy of Sciences Acad. Science USSR Earth SCi. Section, Vol. 282, No. 1-6, pp. 120-125.RussiaKimberlite, Geochemistry
DS1985-0230
1985
Saltykovskiy.Genshaft, YU.S., Vayner, D.I., Saltykovskiy.Crystallization of Minerals of Eclogite Paragenesis at Pressures of 35 to 50 Kbar.Doklady Academy of Science USSR, Earth Science Section., Vol. 273, No. 1-6, PP. 115-118.RussiaGarnet, Composition, Diamond Bearing Eclogites
DS2001-1004
2001
Saltzer, R.L.Saltzer, R.L., Chatterjee, N., Grove, T.L.The spatial distribution of garnets and pyroxenes in mantle peridotites pressure temperature history...Journal of Petrology, Vol. 42, No. 12, pp. 2215-30.South AfricaCraton - Kaapvaal, Peridotites
DS2002-1389
2002
Saltzer, R.L.Saltzer, R.L.Upper mantle structure of the Kaapvaal Craton from surface wave analysis.. a second look.Geophysical Research Letters, Vol. 29, 6, Mar 15, p. 17.South AfricaGeophysics - seismics, Tectonics
DS200412-1723
2004
Saltzer, R.L.Saltzer, R.L., Stutzmann, E., Van der Hilst, R.D.Poisson's ratio in the lower mantle beneath Alaska: evidence for compositional heterogeneity.Journal of Geophysical Research, Vol. 109, B6, B06301, June 9, 10.1029/2003 JB002712United States, AlaskaGeochemistry
DS1994-1519
1994
Salvador, A.Salvador, A.The international stratigraphic guide: a guide to stratigraphicclassification, terminology and procedureGsa Publication Second Edition, 220p. $ approx. 50.00GlobalStratigraphic terminology, Book -ad
DS1990-0219
1990
Salvi, S.Boily, M., Williams-Jones, A.E., Salvi, S.A reappraisal of the geology and geochemistry of the Zr-Y-Nb-Be and rare earth elements (REE)mineralized Strange Lake peralkalinepluton, Quebec-LabradorGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) Vancouver 90 Program with Abstracts, Held May 16-18, Vol. 15, p. A12. AbstractQuebec, LabradorArfvedsonite, Rare earths
DS1990-1295
1990
Salvi, S.Salvi, S., WilliamsJones, A.E.The role of hydrothermal processes in the granite hosted Zirconium, Yttrium, rare earth elements (REE) deposit at Strange Lake, Quebec/Labrador: evidence from fluid inclusionsGeochimica et Cosmochimica Acta, Vol. 54, pp. 2403-2418Quebec, Labrador, UngavaRare earth, Deposit - Strange Lake
DS1991-1493
1991
Salvi, S.Salvi, S., Williams-Jones, A.E.Orthomagmatic fluid inclusions in the Strange Lake complex, Quebec/Labrador: implications for Y, Zr and rare earth elements (REE) concentrationsEuropean Current Research Fluid Inclusions, Firenze, Italy April 10-12, Abstracts, ECROFI XI, p. 189-190Quebec, LabradorFluid inclusions, rare earth elements (REE).
DS1995-1651
1995
Salvi, S.Salvi, S., Williams Jones, A.E.Zirconosilicate phase relations in the Strange Lake Lac Brisson pluton, Quebec-Labrador.American Mineralogist, Vol. 80, pp. 1031-40.Quebec, LabradorAlkaline rocks
DS1995-1652
1995
Salvi, S.Salvi, S., Williams-Jones, A.E.Zirconsilicate phase relations in the Strange Lake (Lac Brisson) pluton, Quebec-Labrador.American Mineralogist, Vol. 80, No. 9-10, Sept, Oct pp. 1031-1040.Quebec, LabradorPeralkaline rocks, Strange Lake
DS200612-0801
2006
Salvi, S.Lenz, D., Lalonde, A., Salvi, S., Paquette, J.Alkaline igneous systems: dissecting magmatic to hydrothermal mineralizing processes.Mineralogical Association of Canada, www.gacmac2006.caCanada, QuebecTechnical meeting - volcanism, alkaline rocks
DS200612-1211
2006
Salvi, S.Salvi, S., Williams-Jones, A.E.Alteration, HFSE mineralization and hydrocarbon formation in peralkaline igneous systems: insights from the Strange Lake Pluton, Canada.Lithos, in press availableCanada, QuebecMagmatism - rare earths
DS201112-0307
2011
Salvi, S.Estrade, G., Salvi, S., Beziat, D., Boix, M.HFSE enrichment in a peralkaline granite-related zircon rich skarn in the Cenozoic Ampasindava alkaline complex, Madagascar.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.42-44.Africa, MadagascarREE
DS201112-0308
2011
Salvi, S.Estrade, G., Salvi, S., Beziat, D., Boix, M.HFSE enrichment in a peralkaline granite-related zircon rich skarn in the Cenozoic Ampasindava alkaline complex, Madagascar.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.42-44.Africa, MadagascarREE
DS201412-0724
2013
Salvi, S.Rasoamalala, V., Salvi, S., Bexiat, D., Ursule, J-Ph., Cuney, M., De Parseval, Ph., Guillaume, D., Moine, B., Andriamampihantona, J.Geology of bastnaesite and monazite deposits in the Ambatofinandrahana area, central part of Madagascar: an overview.Journal of African Earth Sciences, Vol. 94, 14p.Africa, MadagascarBastanesite
DS1993-1656
1993
Salvioli-Mariani, E.Venturelli, G., Salvioli-Mariani, E., Toscani, L., Barbieri, M., Giorgoni, C.Post-magmatic apatite + hematite + carbonate assemblage in the Jumillalamproites. a fluid inclusion and isotope study.Lithos, Vol. 30, pp. 139-150.GlobalLamproites, Geochronology
DS1996-1249
1996
Salvioli-Mariani, E.Salvioli-Mariani, E., Venturelli, G.Temperature of crystallization and evolution of the Jumilla and Cancarix lamproites (southeast Spain)....European Journal of Mineralogy, Vol. 8, No.5, Sept. 1, pp. 1027-1040.GlobalLamproite, melting, Deposit - Jumilla, Cancarix
DS2000-0956
2000
Salvioli-Mariani, E.Toscani, L., Salvioli-Mariani, E.The lamproite of El Tale (Fortuna, southeast Spain)Chemie der Erde, (Eng.), Vol. 60, pp. 96-110.GlobalLamproite, Magmatism
DS200412-1724
2004
Salvioli-Mariani, E.Salvioli-Mariani, E., Toscani, L., Bersani, D.Magmatic evolution of the Gaussberg lamproite ( Antarctica: voltile content and glass composition).Mineralogical Magazine, Vol. 6, 1, pp. 83-100.AntarcticaLamproite
DS201112-0903
2011
Salvioli-Mariani, E.Salvioli-Mariani, E., Toscani, L., Bersani, D., Oddone, M., Cancelliere, R.Late veins of C3 carbonatite intrusion from Jacupiranga complex ( southern Brazil): fluid and melt inclusions and mineralogy.Mineralogy and Petrology, In press available,South America, BrazilCarbonatite
DS201212-0618
2012
Salvioli-Mariani, E.Salvioli-Mariani, E., Toscani, L., Bersani, D., Oddone, M., Cancellielere, R.Late veins of C 3 carbonatite intrusion from Jacupiranga complex, southern Brazil: fluid and melt inclusions and mineralogy.Mineralogy and Petrology, Vol. 104, 1-2, pp. 95-114.South America, BrazilCarbonatite
DS201912-2830
2019
Salvioli-Mariani, E.Toscani, L., Salvioli-Mariani, E., Mattioli, M., Tellini, C., Boschetti, T., Iacumin, P., Selmo, E.The pyroclastic breccia of the Cabezo Negro de Tallant ( SE Spain): the first finding of carbonatite volcanism in the internal domain of the Betic Cordillera.Lithos, in press available, 16p.Europe, Spaincarbonatite
DS1991-1793
1991
Salviolini, E.Venturelli, G., Toscani, L., Salviolini, E., Capedri, S.Mixing between lamproitic and dacitic components in miocene volcanic Rocks of southeast SpainMineralogical Magazine, Vol. 55, No. 379, June pp. 282-285GlobalLamproite, Volcanics
DS1987-0132
1987
Salviulo, G.Dal Negro, A., Cundari, A., Piccirillo, E.M., Salviulo, G.Genetic significance of the clinopyroxene from lamproites and relatedrocks: a crystal chemical studyTerra Cognita, Conference abstracts Oceanic and Continental Lithosphere:, Vol. 7, No. 4, Autumn, abstract only p. 610AustraliaBlank
DS1989-0316
1989
Salviulo, G.Cundari, A., Salviulo, G.Ti solubility in diopsidic pyroxene from a suite of New SouthWalesleucititesLithos, Vol. 22, No. 3, March pp. 191-198AustraliaLeucitite
DS1992-1323
1992
Salviulo, G.Salviulo, G., Princivalle, F., Demarchi, G., Fabro, C.Effects of Ca-magnesium substitution in C2/c pyroxene structure on natural clinopy roxenes from spinel peridotite nodules (Pico Cabugi, Brasil).Phys. Chem. Minerals, Vol. 19, pp. 213-219.BrazilNodules, Peridotite
DS1994-1413
1994
Salviulo, G.Princivalle, F., Salviulo, G., Fabro, C., Demarchi, G.Inter and intra crystalline temperature and pressure estimates on pyroxenes from northeast Brasil mantle xenoliths.Contr. Mineralogy and Petrology, Vol. 116, No. 1/2, pp. 1-6.BrazilXenoliths
DS2000-0780
2000
Salviulo, G.Princivalle, F., Salviulo, G., Marzoli, PiccirilloClinopyroxene of spinel peridotite mantle xenoliths from Lake Nji: crystal chemistry and petrological....Contributions to Mineralogy and Petrology, Vol. 139, No. 5, pp. 503-8.GlobalMantle xenoliths
DS202011-2056
2020
Salzmann, C.Nemeth, P., McColl, K., Garvie, L.A.J., Salzmann, C.Complex nanostructures in diamond. Nature Materials, doi:10.1038/s4 1563-020-0759-8 7p. PdfGlobalmeteorites, synthetics

Abstract: Meteoritic diamonds and synthesized diamond-related materials contain a wide variety of complex nanostructures. This Comment highlights and classifies this structural complexity by a systematic hierarchical approach, and discusses the perspectives on nanostructure and properties engineering of diamond-related materials.
DS201511-1876
2015
Salzmann, C.G.Salzmann, C.G., Murray, B.J., Shephard, J.J.Extent of stacking disorder in diamond. ( hexagonal)Diamond and Related Materials, Vol. 59, pp. 69-72.TechnologyLonsdaleite

Abstract: Hexagonal diamond has been predicted computationally to display extraordinary physical properties including a hardness that exceeds cubic diamond. However, a recent electron microscopy study has shown that so-called hexagonal diamond samples are in fact not discrete materials but faulted and twinned cubic diamond. We now provide a quantitative analysis of cubic and hexagonal stacking in diamond samples by analysing X-ray diffraction data with the DIFFaX software package. The highest fractions of hexagonal stacking we find in materials which were previously referred to as hexagonal diamond are below 60%. The remainder of the stacking sequences are cubic. We show that the cubic and hexagonal sequences are interlaced in a complex way and that naturally occurring Lonsdaleite is not a simple phase mixture of cubic and hexagonal diamond. Instead, it is structurally best described as stacking disordered diamond. The future experimental challenge will be to prepare diamond samples beyond 60% hexagonality and towards the so far elusive 'perfect' hexagonal diamond.
DS201611-2116
2016
Salzmann, C.G.Jones, A.P., McMillan, P.F., Salzmann, C.G., Alvaro, M., Nestola, F., Prencipe, M., Dobson, D., Hazael, R., Moore, M.Structural characteristization of natural diamond shocked to 60 Gpa: implications for Earth and Planetary Systems.Lithos, in press available 25p.TechnologyNatural diamonds

Abstract: The possible presence of the high-density carbon polymorph with hexagonal symmetry known as "lonsdaleite" provides an important marker for shock impact events. It is typically considered to form as a metastable phase produced from graphite or other carbonaceous precursors. However, its existence has recently been called into question. Here we collected high-resolution synchrotron X-ray diffraction data for laboratory-shocked and natural impact diamonds that both show evidence for deviations from cubic symmetry, that would be consistent with the appearance of hexagonal stacking sequences. These results show that hexagonality can be achieved by shocking diamond as well as from graphite precursors. The diffraction results are analyzed in terms of a general model that describes intermediate stacking sequences between pure diamond (fully cubic) and "lonsdaleite" (fully hexagonal) phases, with provision made for ordered vs disordered stacking arrangements. This approach provides a "hexagonality index" that can be used to characterize and distinguish among samples that have experienced different degrees of shock or static high pressure-high temperature treatments. We have also examined the relative energetics of diamond and "lonsdaleite" structures using density functional theoretical (DFT) methods. The results set limits on the conditions under which a transformation between diamond and "lonsdaleite" structures can be achieved. Calculated Raman spectra provide an indicator for the presence of extended hexagonal stacking sequences within natural and laboratory-prepared samples. Our results show that comparable crystallographic structures may be developed by impact-generated shockwaves starting from ambient conditions using either of the two different allotropes of carbon (diamond, graphite). This broadens the scope for its occurrence in terrestrial and planetary systems.
DS201701-0016
2016
Salzmann, C.G.Jones, A.P., McMillan P.F., Salzmann, C.G., Alvaro, M., Nestola, F., Prencipe, M., Dobson, D., Hazael, R., Moore, M.Structual characterization of natural diamond shocked to 60 Gpa; implications for Earth and Planetary Systems.Lithos, In press availableTechnologyDiamond morphology

Abstract: The possible presence of the high-density carbon polymorph with hexagonal symmetry known as “lonsdaleite” provides an important marker for shock impact events. It is typically considered to form as a metastable phase produced from graphite or other carbonaceous precursors. However, its existence has recently been called into question. Here we collected high-resolution synchrotron X-ray diffraction data for laboratory-shocked and natural impact diamonds that both show evidence for deviations from cubic symmetry, that would be consistent with the appearance of hexagonal stacking sequences. These results show that hexagonality can be achieved by shocking diamond as well as from graphite precursors. The diffraction results are analyzed in terms of a general model that describes intermediate stacking sequences between pure diamond (fully cubic) and “lonsdaleite” (fully hexagonal) phases, with provision made for ordered vs disordered stacking arrangements. This approach provides a “hexagonality index” that can be used to characterize and distinguish among samples that have experienced different degrees of shock or static high pressure-high temperature treatments. We have also examined the relative energetics of diamond and “lonsdaleite” structures using density functional theoretical (DFT) methods. The results set limits on the conditions under which a transformation between diamond and “lonsdaleite” structures can be achieved. Calculated Raman spectra provide an indicator for the presence of extended hexagonal stacking sequences within natural and laboratory-prepared samples. Our results show that comparable crystallographic structures may be developed by impact-generated shockwaves starting from ambient conditions using either of the two different allotropes of carbon (diamond, graphite). This broadens the scope for its occurrence in terrestrial and planetary systems.
DS201908-1797
2019
Salzmann, C.G.Murri, M., Smith, R.L., McColl, K., Hart, M., Alvaro, M., Jones, A.P., Nemeth, P., Salzmann, C.G., Cora, F., Domeneghetti, M.C., Nestola, F., Sobolev, N.V., Vishnevsky, S.A., Logvinova, A.M., McMillan, P.F.Quantifying hexagonal stacking in diamond. ( lonsdaleite)Nature Scientific Reports, doi.org/10.1038/ s41598-019-46556-3 8p. PdfGlobaldiamond morphology, impact craters

Abstract: Diamond is a material of immense technological importance and an ancient signifier for wealth and societal status. In geology, diamond forms as part of the deep carbon cycle and typically displays a highly ordered cubic crystal structure. Impact diamonds, however, often exhibit structural disorder in the form of complex combinations of cubic and hexagonal stacking motifs. The structural characterization of such diamonds remains a challenge. Here, impact diamonds from the Popigai crater were characterized with a range of techniques. Using the MCDIFFaX approach for analysing X-ray diffraction data, hexagonality indices up to 40% were found. The effects of increasing amounts of hexagonal stacking on the Raman spectra of diamond were investigated computationally and found to be in excellent agreement with trends in the experimental spectra. Electron microscopy revealed nanoscale twinning within the cubic diamond structure. Our analyses lead us to propose a systematic protocol for assigning specific hexagonality attributes to the mineral designated as lonsdaleite among natural and synthetic samples.
DS202011-2054
2020
Salzmann, C.G.Murri, M., Smith, R.L., McColl, K., Hart, M., Alvaro, M., Jones, A.P., Nemeth, P., Salzmann, C.G., Cora, F., Domeneghetti, M.C., Nestola, F., Sobolev, N.V., Vishnevsky, S.A., Logvinova, A.M., McMillan, P.F.Quantifying hexagonal stacking in diamond.Nature/scientific reports, 8p. PdfGlobalcrystallography

Abstract: Diamond is a material of immense technological importance and an ancient signifier for wealth and societal status. In geology, diamond forms as part of the deep carbon cycle and typically displays a highly ordered cubic crystal structure. Impact diamonds, however, often exhibit structural disorder in the form of complex combinations of cubic and hexagonal stacking motifs. The structural characterization of such diamonds remains a challenge. Here, impact diamonds from the Popigai crater were characterized with a range of techniques. Using the MCDIFFaX approach for analysing X-ray diffraction data, hexagonality indices up to 40% were found. The effects of increasing amounts of hexagonal stacking on the Raman spectra of diamond were investigated computationally and found to be in excellent agreement with trends in the experimental spectra. Electron microscopy revealed nanoscale twinning within the cubic diamond structure. Our analyses lead us to propose a systematic protocol for assigning specific hexagonality attributes to the mineral designated as lonsdaleite among natural and synthetic samples.
DS1994-1428
1994
Samaddar, A.B.Ramani, R.J., Mozumdar, B.K., Samaddar, A.B.Computers in mineral industryA.a.balkema, 350pGlobalEconomics, evaluation, geostatistics, ore reserves, Book -table of contents
DS201708-1565
2016
Samaila, N.K.Bata, T., Parnell, J., Samaila, N.K., Haruna, A.I.Anomalous occurrence of Cretaceous placer deposits: a review. Earth and Atmospheric Sciences, Vol. 1, pp. 1-13.Mantlealluvials

Abstract: During the Cretaceous, the CO2 content of the global atmosphere drastically increased in response to volcanism associated with the disintegration of the former continents. This increase in the global atmospheric CO2 level subsequently led to a considerable rise in global temperatures. The interaction among the high levels of atmospheric CO2, extreme global warmth, and humidity witnessed in the Cretaceous implies extreme environmental conditions, which involved a possibly more acidic and chemically destructive atmosphere than at present; these conditions are believed to have favoured widespread deep weathering at that time. Economically important minerals were reworked from their primary sources during these Cretaceous weathering events. The extreme global warmth witnessed in the Cretaceous also caused the melting of most of the polar ice caps, resulting in the expansion of the volume of Cretaceous seawaters, which subsequently led to a significant rise in the global sea level. Extensive palaeo-seaways played a vital role in transporting and depositing the huge volume of sediments generated during the Cretaceous weathering events, which included economically important minerals (e.g., gold, diamond, and platinum). These mineral deposits are now preserved in Cretaceous sands as placer deposits. Three categories of Cretaceous placer deposits can be distinguished: those occurring in Cretaceous sands resting unconformably on the Precambrian basement, those occurring in Cretaceous sands resting unconformably on the Palaeozoic rocks, and those occurring in Cretaceous sands that unconformably overlay Mesozoic strata.
DS201902-0317
2019
Samal, A.K.Samal, A.K., Srivastava, R.K., Ernst, R.E., Soderlund, U.Neoarchean-Mesoproterozoic mafic dyke swarms of the Indian shield mapped using google Earth images and ArcGIStm, and links with Large Igneous Provinces.Srivastava: Dyke Swarms of the World: a Modern Perspective, Springer, researchgate 56p. PdfIndiadykes

Abstract: We present dyke swarm maps generated using Google Earth™ images, ArcGIS™, field data, and available geochronological ages of Neoarchean-Mesoproterozoic (ranging in age from ~2.80 to ~1.10 Ga) mafic dyke swarms and associated magmatic units of the different Archean cratons of the Indian shield which represent the plumbing system of Large Igneous Provinces (LIPs). The spatial and temporal distributions together with the trends of the dyke swarms provide important informations about geodynamics. Twenty four dyke swarms (17 have been precisely dated), mostly mafic in nature, have been mapped from the different cratons and named/re-named to best reflect their location, trend, distribution and distinction from other swarms. We have identified 14 distinct magmatic events during the Neoarchean-Mesoproterozoic in the Indian shield. These intraplate magmatic events (many of LIP scale) of the Indian shield and their matches with coeval LIPs on other crustal blocks suggest connections of the Indian shield within known supercontinents, such as Kenorland/Superia (~2.75-2.07 Ga), Columbia/Nuna (1.90-1.38 Ga), and Rodinia (1.20-0.72 Ga). However, further detailed U-Pb geochronology and associated paleomagnetism are required to come to any definite constraints on the position of the Indian cratons within these supercontinents.
DS201905-1070
2019
Samal, A.K.Rai, A.K., Srivastava, R.K., Samal, A.K., Sesha Sai, V.V.Geochemistry, petrogenesis, and geodynamic implications of NE-SW to ENE - WSW trending Paleoproterozoic mafic dyke swarms from southern region of the western Dharwar Craton.Geological Journal, Doi: 10.1002/gj.3493Indiageodynamics

Abstract: A number of NE-SW to ENE-WSW trending Palaeoproterozoic mafic dykes, intruded within the Archean basement rocks and more conspicuous in the southern parts of the western Dharwar Craton (WDC), was studied for their whole?rock geochemistry to understand their petrogenetic and geodynamic aspects. Observed mineralogical and textural characteristics classify them either as meta?dolerites or dolerites/olivine?dolerites. They show basaltic to basaltic-andesitic compositions and bear sub?alkaline tholeiitic nature. Three geochemically distinct groups of mafic dykes have been identified. Group 1 samples show flat REE patterns (LaN/LuN = ~1), whereas the other two groups have LaN/LuN = ~2-3 (Group 2; enriched LREE and flat HREE patterns) and LaN/LuN = ~4 (Group 3; inclined REE patterns). Chemistry is not straightforward to support any significant role of crustal contamination and probably reflect their source characteristics. However, their derivation from melts originated from a previously modified metasomatized lithospheric mantle due to some ancient subduction event cannot be ignored. Most likely different mantle melts were responsible for derivation of these distinct sets of mafic dykes. The Group 2 dykes are derived from a melt generated within spinel stability field by ~10% batch melting of a lithospheric mantle source, whereas the Group 3 dykes have their derivation from a melt originated within the spinel-garnet transition zone and were fed from slightly higher (~12-15%) batch melting of a similar source. The Group 1 samples were also crystallized from a melt generated at the transition zone of spinel-garnet stability field by higher degrees (~20%) of melting of a primitive mantle source. Geochemistry of the studied samples is typical of Palaeoproterozoic mafic dykes emplaced within the intracratonic setting, reported elsewhere globally as well as neighbouring cratons. Geochemistry of the studied mafic dyke samples is also compared with the mafic dykes of the eastern Dharwar Craton (EDC). Except the Group 3 samples, which have good correlation with the 1.88-1.89 Ga Hampi swarm, no other group shows similarity with the EDC mafic dykes. There is an ample possibility to have some different mafic magmatic events in the WDC, which could be different from the EDC. However, it can only be confirmed after precise age determinations.
DS201905-1077
2018
Samal, A.K.Soderlund, U., Bleeker, W., Demirer, K., Srivastava, R.K., Hamilton, M., Nilsson, M., Personen, L.J., Samal, A.K., Jayananda, M., Ernst, R.E., Srinivas, M.Emplacement ages of Paleoproterozoic mafic dyke swarms in eastern Dharwar craton, India: implications for paleoreconstructions and support for a ~30 degree change in dyke trends from south to north.Precambrian Research, doi.org/10.1016/ j.precamres.2018.12.017Indiacraton

Abstract: Large igneous provinces (LIPs) and especially their dyke swarms are pivotal to reconstruction of ancient supercontinents. The Dharwar craton of southern Peninsular India represents a substantial portion of Archean crust and has been considered to be a principal constituent of Superia, Sclavia, Nuna/Columbia and Rodinia supercontinents. The craton is intruded by numerous regional-scale mafic dyke swarms of which only a few have robustly constrained emplacement ages. Through this study, the LIP record of the Dharwar craton has been improved by U-Pb geochronology of 18 dykes, which together comprise seven generations of Paleoproterozoic dyke swarms with emplacement ages within the 2.37-1.79 Ga age interval. From oldest to youngest, the new ages (integrated with U-Pb ages previously reported for the Hampi swarm) define the following eight swarms with their currently recommended names: NE-SW to ESE-WNW trending ca. 2.37 Ga Bangalore-Karimnagar swarm. N-S to NNE-SSW trending ca. 2.25 Ga Ippaguda-Dhiburahalli swarm. N-S to NNW-SSE trending ca. 2.22 Ga Kandlamadugu swarm. NW-SE to WNW-ESE trending ca. 2.21 Ga Anantapur-Kunigal swarm. NW-SE to WNW-ESE trending ca. 2.18 Ga Mahbubnagar-Dandeli swarm. N-S, NW-SE, and ENE-WSW trending ca. 2.08 Ga Devarabanda swarm. E-W trending 1.88-1.89 Ga Hampi swarm. NW-SE ca. 1.79 Ga Pebbair swarm. Comparison of the arcuate trends of some swarms along with an apparent oroclinal bend of ancient geological features, such as regional Dharwar greenstone belts and the late Archean (ca. 2.5 Ga) Closepet Granite batholith, have led to the hypothesis that the northern Dharwar block has rotated relative to the southern block. By restoring a 30° counter clockwise rotation of the northern Dharwar block relative to the southern block, we show that pre-2.08 Ga arcuate and fanning dyke swarms consistently become approximately linear. Two possible tectonic models for this apparent bending, and concomitant dyke rotations, are discussed. Regardless of which deformation mechanisms applies, these findings reinforce previous suggestions that the radial patterns of the giant ca. 2.37 Ga Bangalore-Karimnagar dyke swarm, and probably also the ca. 2.21 Ga Anantapur-Kunigal swarm, may not be primary features.
DS201909-2081
2019
Samal, A.K.Samal, A.K., Srivastava, R.K., Ernst, R.E., Soderlund, U.Precambrian large igneous province record of the Indian Shield: an update based on extensive U-Pb dating of mafic dyke swarms.Precambrian Research, doi.org/j.precamres .2018.12.07 24p.Indiacarbonatite, kimberlite
DS201912-2828
2019
Samal, A.K.Srivastava, R.K., Soderlund, U., Ernst, R.E., Mondal, S.K., Samal, A.K.Precambrian mafic dyke swarms in the Singhbhum craton ( eastern India) and their links with syke swarms of the eastern Dhwar craton ( southern India).Precambrian Research, Vol. 329, pp. 5-17.Indiacraton

Abstract: Based on trend, cross-cutting relationships and U-Pb dating, Precambrian mafic dykes in the Singhbhum craton, earlier collectively identified as ‘Newer Dolerite Swarm’ have been separated into seven distinct swarms, which are thought to be the plumbing systems for Large Igneous Provinces (LIPs). These Singhbhum swarms range in age from ?2.80 Ga to ?1.76 Ga, and include the ?2.80 Ga NE-SW trending Keshargaria swarm, ?2.75-2.76 Ga NNE-SSW to NE-SW trending Ghatgaon swarm, the ?2.26 Ga NE-SW to ENE-WSW trending Kaptipada swarm (based on a new U-Pb ID-TIMS age 2256 ± 6 Ma), the ?1.77 Ga WNW-ESE trending Pipilia swarm, the early-Paleoproterozoic E-W to ENE-WSW trending Keonjhar swarm, the middle-Paleoproterozoic NW-SE to NNW-SSE trending Bhagamunda swarm, and the late-Paleoproterozoic N-S to NNE-SSW trending Barigaon swarm. Two of the Singhbhum swarms, the ?2.26 Ga Kaptipada and ?1.77 Ga Pipilia, are closely matched with the ?2.26-2.25 Ga Ippaguda-Dhiburahalli and ?1.79 Ga Pebbair swarms, respectively, of the eastern Dharwar craton. The correlations suggest that the Singhbhum and Dharwar cratons were close enough at these times to share two reconstructed LIPs, a 2.26-2.25 Ga Kaptipada- Ippaguda-Dhiburahalli LIP and a 1.79-1.77 Ga Pipilia-Pebbair LIP, and if so, both swarms must be present in the intervening Bastar craton (candidates are proposed). Also, the 2.76-2.75 Ga Ghatgaon swarm of the Singhbhum craton can be provisionally correlated with ?2.7 Ga Keshkal swarm of the Bastar craton. The 2.26-2.25 Ga Kaptipada-Ippaguda-Dhiburahalli LIP of the Singhbhum-Bastar-Dharwar reconstruction has age matches in the Vestfold Hills of Antarctica (?2.24 Ga dykes), the Kaapvaal craton (the ?2.25-2.23 Ga Hekpoort lavas) and perhaps the Zimbabwe craton (2.26 Ga Chimbadzi troctolite intrusions). The 1.76-1.79 Ga Pipilia-Pebbair LIP of the Singhbhum-Bastar-Dharwar reconstruction has age matches in the North China, Australian Shield, Amazonian, Rio de Plata and Sarmatia cratons. The relevance of these matches for reconstructions will require future testing using paleomagnetic studies. While there are ?2.7-2.8 Ga LIP-type greenstone belts in many crustal blocks, there are no precise matches with the 2.76-2.75 Ga Ghatgaon swarm of the Singhbhum craton. Howe
DS2002-1390
2002
Samaniego, P.Samaniego, P.Transition from calc-alkalic to adakitic magmatism at Cayambe volcano, Ecuador: insights into slab melts and mantle wedge interactions.Geology, Vol. 30, 11, Nov. pp.967-70.EcuadorMelting - slab subduction
DS201909-2100
2019
Samanta, A.Vadlamani, R., Bera, M.K., Samanta, A., Mukherjee, S., Adhikari, A., Sarkar, A.Oxygen, Sr and Nd isotopic evidence from kyanite-eclogite xenoliths ( KL-2 pipe, Wajrakarur) for pre- 1.1 Ga mantle metasomatism in eastern Dharwar SCLM.Goldschmidt2019, 1p. AbstractIndiadeposit - KL-2

Abstract: Kyanite-eclogite xenoliths from Wajrakarur are considered as remnants of subducted ocean-floor crust [1]. Here trace element concentration and isotopic data are presented in garnet (Grt) and kyanite (Ky) from xenoliths KL-2 E1-E4, characterized by [2]). We use the precise 87Sr/86Sr host kimberlite groundmass perovskite ratio (0.70312-0.70333, [3]) as a proxy for the extent of kimberlitic magma infiltration at 1.1 Ga. The xenolithic Grt and Cr-rich (upto 1506 ppm) Ky have more radiogenic 87Sr/86Sr values than kimberlite, at 1.1 Ga, of 0.703829-0.705203 and 0.703811-0.704502, respectively. Furthermore, the Grt and Ky 143Nd/144Nd ratios, at 1.1 Ga, are 0.509321-0.511372 and 0.510951-0.511156, respectively, and are distinctly lower than those of the host kimberlite (0.511870-0.512290, [4]). This indicates that the infiltration of kimberlitic fluid has not altered the 87Sr/86Sr and 143Nd/144Nd ratios in the Grt and Ky, and therefore their isotope compositions must be inherited and predate the kimberlite magma generation event at 1.1 Ga. Trace elements in Grt and Ky indicate extreme metasomatism (Sr in Grt 104-296 ppm, in Ky 672-8713 ppm [limit Sr<2ppm] and Nb in Grt 0.64-1.78 ppm, in Ky 1.7-4.54 ppm [limit Nb<0.5ppm]). The xenoliths underwent at least one major melting event inferred from extreme depletions in Re, Os and 177Os/178Os ratios [5]. Their mantle-like ?18O values (Grt 5.3-5.4‰, Ky 5.3-5.9‰), positive Eu anomalies in both Grt and Ky (similar to Group 1 HREE-depleted garnets of [1]) suggests that the protolith likely was a chromite-bearing leucogabbro, emplaced as a high-pressure cumulate at the crust-mantle boundary, which was later eclogitized due to deep-seated subduction and underwent episodes of extreme melting and metasomatism before 1.1 Ga and at least before 1.7 Ga, as inferred from their youngest Re depletion dates [5].
DS201312-0341
2013
Samarin, S.Guagliardo, P., Byrne, K.,Chapman, J.,Sudarshan, K., Samarin, S., Williams, J.Positron annihilation and optical studies of natural brown type 1 diamonds.Diamond and Related Materials, Vol. 37, pp. 37-40.TechnologyBrown diamonds
DS201809-2107
2018
Samata, A.Vadlamani, R., Bera, M.K., Samata, A., Mukherjee, S., Adhikari, A., Sarkar, A.Oxygen, Sr and Nd isotopic evidence from kyanite eclogite xenoliths ( KL-2 pipe, Wajrakarur) for pre 1.1 Ga mantle metasomatism in eastern Dharwar SCLM.Goldschmidt Conference, 1p. AbstractIndiadeposit - KL-2

Abstract: Kyanite-eclogite xenoliths from Wajrakarur are considered as remnants of subducted ocean-floor crust. Here trace element concentration and isotopic data are presented in garnet (Grt) and kyanite (Ky) from xenoliths KL-2 E1-E4, characterized by. We use the precise 87Sr/86Sr host kimberlite groundmass perovskite ratio (0.70312-0.70333, as a proxy for the extent of kimberlitic magma infiltration at 1.1 Ga. The xenolithic Grt and Cr-rich (upto 1506 ppm) Ky have more radiogenic 87Sr/86Sr values than kimberlite, at 1.1 Ga, of 0.703829-0.705203 and 0.703811-0.704502, respectively. Furthermore, the Grt and Ky 143Nd/144Nd ratios, at 1.1 Ga, are 0.509321-0.511372 and 0.510951-0.511156, respectively, and are distinctly lower than those of the host kimberlite (0.511870-0.512290). This indicates that the infiltration of kimberlitic fluid has not altered the 87Sr/86Sr and 143Nd/144Nd ratios in the Grt and Ky, and therefore their isotope compositions must be inherited and predate the kimberlite magma generation event at 1.1 Ga. Trace elements in Grt and Ky indicate extreme metasomatism (Sr in Grt 104-296 ppm, in Ky 672-8713 ppm [limit Sr<2ppm] and Nb in Grt 0.64-1.78 ppm, in Ky 1.7-4.54 ppm [limit Nb<0.5ppm]). The xenoliths underwent at least one major melting event inferred from extreme depletions in Re, Os and 177Os/178Os ratios [5]. Their mantle-like ?18O values (Grt 5.3-5.4‰, Ky 5.3-5.9‰), positive Eu anomalies in both Grt and Ky (similar to Group 1 HREE-depleted garnets of) suggests that the protolith likely was a chromite-bearing leucogabbro, emplaced as a high-pressure cumulate at the crust-mantle boundary, which was later eclogitized due to deep-seated subduction and underwent episodes of extreme melting and metasomatism before 1.1 Ga and at least before 1.7 Ga, as inferred from their youngest Re depletion dates.
DS2001-0960
2001
Sambandam, S.T.Raju, D.C.I., Thakur, K.S., Shrivastava, S.K., Sambandam, S.T., Khoitpal, A.S.Ground evaluation of aeromagnetic and spectrometric and other integrated dat a inIndia Geological Survey Records, No. 135, 2, p. 129-131.IndiaNews item - diamond discoveries
DS1998-0548
1998
Sambridge, M.Gudmundsson, O., Sambridge, M.A regionalized upper mantle (RUM) seismic modelJournal of Geophysical Research, Vol. 103, No. 4, Apr. 10, pp. 7121-36.MantleGeophysics - seismic, Model
DS201312-0916
2013
Sambridge, M.Tkalcic, H., Young, M.K., Bodin, T., Ngo, S., Sambridge, M.The shuffling rotation of the Earth's inner core.Nature Geoscience, Vol. 6, pp. 497-502.MantleGeodynamics
DS201412-1011
2013
Sambridge, M.Young, M.K., Tkalcic, H., Bodin, T., Sambridge, M.Global P wave tomography of Earth's lowermost mantle from partition modeling.Journal of Geophysical Research, Vol. 118, 10, pp. 5467-5486.MantleGeophysics - tomography
DS200612-1212
2006
Sambrook Smith, G.Sambrook Smith, G., Best, J., Bristow, C., Petts, G.E.Braided rivers.Blackwell Pubisher, 396p. $ 150.00Asia, EuropeBook - geomorphology
DS201606-1111
2016
Samdanov, D.A.Samdanov, D.A., Afanasiev, V.P., Tychkov, N.S., Pokhilenko, N.P.Mineralogical zoning of the Diamondiferous areas: application experience of paragenetic analysis of garnets from kimberlites.Doklady Earth Sciences, Vol. 467, 1, pp. 228-231.Russia, YakutiaDeposit area - Muna-Markha

Abstract: Paragenetic analysis of pyropes from alluvial deposits of the Muna—Markha interfluve (Sakha-Yakutia Republic) made it possible to distinguish relatively uniform areas that are promising for the discovery of kimberlite bodies.
DS202104-0563
2020
Samdanov, D.A.Afanasiev, V.P., Pohilenko, N.P., Kuligin, S.S., Samdanov, D.A.On the prospects of diamond content of the southern side of the Vilyui syneclise. ( Lena River)Geology of Ore Deposits, Vol. 62, 6, pp. 535-541.RussiaIndicator minerals

Abstract: The paper describes indicator minerals of kimberlites found on the southern side of the Vilyui syneclise in the Markha River basin, a tributary of the Lena River. It is shown that indicator minerals-pyrope and picroilmenite-derive from Middle Paleozoic kimberlites, very likely diamondiferous. Methods are proposed for further studies on determining the prospects for the diamond content of the southern side of the Vilyui syneclise and the northern slope of the Aldan anteclise.
DS200712-0929
2007
Sames, C.W.Sames, C.W.The mineral industry of India.Minerals & Energy - Raw Materials Report, Vol. 21, 3-4, pp. 19-34.IndiaOverview - history
DS200712-0930
2007
Sames, C.W.Sames, C.W.The mineral industry of India.Minerals & Energy - Raw Materials Report, Vol. 21, 3-4, pp. 19-34.IndiaOverview - history
DS2000-0852
2000
SAMI Brochure infoSAMI Brochure infoBrief overview of properties in the Juin a area..Sami Brochure Info, 7p.South AmericaNews item
DS2001-1029
2001
Samil, R.Schissel, D., Samil, R.Deep mantle plumes and ore depositsGeological Society of America, Special Paper, Special Paper. 352, pp. 291-322.MantlePlumes, Metallogeny
DS1998-1281
1998
Samis, M.Samis, M., Poulin, R.Valuing management flexibility: a basis to compare the standard DCF and MAP valuation frameworksThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin), Vol. 91, No. 1019, Apr. pp. 69-74CanadaEconomics, reserves, valuations, discoveries, DCF, MAP, option pricing
DS1993-1372
1993
Sammis, C.G.Sammis, C.G.Fractals and chaos in the earth sciencesPageophy. Reprint, Vol. 138, No. 4, 177p. approx. $ 45.00GlobalBook -ad, Fractals
DS1992-1324
1992
Sammonds, P.R.Sammonds, P.R., Meredith, P.G., Main, I.G.Role of pore fluids in the generation of seismic precursors to shearfractureNature, Vol. 359, No. 6392, September 17, p. 228-230GlobalCrust deformation, Geophysics -seismics
DS201012-0021
2010
Samoah Sakyi, P.Asiedu, D.K., Dampare, S.B., Samoah Sakyi, P., Boamah, D.Major and trace element geochemistry of kimberlitic rocks in the Akwatia area of the Birim Diamondiferous field, southwest Ghana.African Journal of Science and Technology, Science and Engineering series, Vol. 8, 2, pp. 81-91.Africa, GhanaDeposit - Akwatia
DS1987-0642
1987
Samoilov, V.M.Samoilov, V.M.Microscopic model of anomalous muonium in silicon ,germanium,anddiamond.(Russian)Pisma ZH. Exsp. Teor. Fiz., (Russian), Vol. 45, No. 5, pp. 234-236RussiaBlank
DS1987-0643
1987
Samoilov, V.S.Samoilov, V.S., Ronenson, B.M.Geochemical pecularities of alkaline palingenesis.(Russian)Geochemistry International (Geokhimiya), (Russian), No. 11, pp. 1537-1545RussiaBlank
DS1987-0644
1987
Samoilov, V.S.Samoilov, V.S., Ronenson, B.M., Sobachenko, V.N.Geochemistry of alkaline palingenesis and the associatedcarbonatiteformation.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 196, No. 4, pp. 976-980RussiaBlank
DS1989-1328
1989
Samoilov, V.S.Samoilov, V.S.Geochemical classification of carbonatites.(Russian)Geochemistry International (Geokhimiya), (Russian), No. 9, pp. 1282-1292RussiaCarbonatite, Geochemistry
DS1989-1329
1989
Samoilov, V.S.Samoilov, V.S.The main geochemical features of carbonatites #1Xiii International Geochemical Exploration Symposium, Rio 89 Brazilian, pp. 68-69. AbstractRussiaCarbonatite, Geochemistry
DS1990-1296
1990
Samoilov, V.S.Samoilov, V.S.Mineralogy, geochemistry and genesis of carbonatites of MongoliaInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 2, extended abstract p. 951-952RussiaCarbonatite, Mineralogy
DS1991-1494
1991
Samoilov, V.S.Samoilov, V.S.The main geochemical features of carbonatites #2Journal of Geochemical Exploration, Special Publications Geochemical, Vol. 40, No. 1-3, pp. 251-262BrazilCarbonatite, Review -geochemistry
DS2002-1391
2002
Samoilov, V.S.Samoilov, V.S.Richterite magnesioar fvedsonite magnesioriebeckite isomorphoric series: evidence from carbonatites of Eastern Siberia.Neues Jahrbuch Mineralogie, Abhundlung, Vol. 177, pp. 199-211.Russia, SiberiaCarbonatite - mineralogy, analyses
DS200712-0931
2007
Samoilov, V.S.Samoilov, V.S., Vapnik, Y.Fractional melting the determining factor in the origin of the tephrite basanite nephelinite rock some evidence from western Makhtesh Ramon, Israel.Neues Jahrbuch fur Mineralogie, Vol. 184, 2, pp. 181-195.Europe, IsraelBasanites, Foidites
DS200812-0997
2007
Samoilov, V.S.Samoilov, V.S., Vapnik, Y.Fractional melting the determining factor in the origin of the tephrite basanite nephelinite rock suite: evidence from western Makhtesh Ramon, Israel.Neues Jahrbuch fur Mineralogie, Vol. 184, 2, pp. 181-195.Europe, IsraelBasanites, Foidites
DS1985-0584
1985
Samoilovich, M.I.Samoilovich, M.I.Features of the Graphite Diamond Phase TransformationSoviet Physics, Doklady Academy of Sciences, Vol. 30, No. 5, pp. 344-345RussiaDiamond Morphology
DS1987-0645
1987
Samoilovich, M.I.Samoilovich, M.I.Thermodynamic pecularities of the diamond formation. (Russian)Doklady Academy of Sciences Akademy Nauk SSSR (Russian), Vol. 296, No. 3, pp. 602-604RussiaBlank
DS1987-0646
1987
Samoilovich, M.I.Samoilovich, M.I.Thermodynamics of diamond formation.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 296, No. 3, pp. 602-604RussiaBlank
DS1988-0403
1988
Samoilovich, M.I.Laptev, V.A., Pomchalov, A.V., Samoilovich, M.I.Diamond crystallization characteristics in a system consisting of a meta land difficulty graphitizable carbonaceous substances. (Russian)Sverkhtverd. Mater., (Russian), No. 4, pp. 13-17RussiaDiamond morphology
DS1985-0585
1985
Samolov, M.I.Samolov, M.I., Sokolina, G.A., Iakovlev, E.N.Specific Features of Graphite-diamond Phase TransformationDoklady Academy of Sciences Nauk SSSR., Vol. 282, No. 3, PP. 617-619.RussiaMineralogy
DS200612-1429
2006
SamosorovTitkov, S.V., Gorshkov, A.I., Solodova, Ryabchikov, Magazina, Sivtsov, Gasanov, Sedova, SamosorovMineral Micro inclusions in cubic diamonds from the Yakutian deposits based on analytical electron microscopy data.Doklady Earth Sciences, Vol. 410, no. 7 July-August, pp. 1106-1108.Russia, YakutiaDiamond inclusions
DS200712-1084
2006
SamosorovTitkov, S.V., Solodova, Y.P., Gorshkov, A.I., Magaina, L.O., Sivtsov, A.V., Sedova, E.A., Gasanov, SamosorovInclusions in white gray diamonds of cubic habit from Siberia.Gems & Gemology, 4th International Symposium abstracts, Fall 2006, p.127-8. abstract onlyRussiaDiamond morphology
DS202108-1284
2021
Samosorov, G.Garanin, V., Garanin, K., Kriulina, G., Samosorov, G.Geological summary of kimberlites and related rocks in the Archangelsk diamondiferous region ( ADR).Book: Diamonds from the Arkangelk Province, NW Russia., July doi.10.1007/978-3-030-35717-7_1 30p.Russia, Archangelkimberlites

Abstract: The chapter headlines the historical perspective of discovering the Arkhangelsk Diamondiferous Region, previously was also called the Arkhangelsk Diamondiferous Province (hereinafter named ADR), offers the contemporary concept of the ADR geology, and location of kimberlite fields and magmatic rock bodies in its area. It describes the layout, structure, mineralogical characteristics and lithology of pipes from the Grib and Lomonosov deposits. It gives a snapshot of the alkaline ultrabasic rocks’ representatives from the Zimny Bereg area of the ADR that is not covered by the deposits.
DS202111-1766
2021
Samosorov, G.Garanin, V., Garanin, K., Kriulina, G., Samosorov, G.Diamonds from the Arkangelsk Province, NW Russia. ENGLISHSpringer Mineralogy http://www.springer.com/series/13488, Reference to the book only! Russia, Arkangelskdiamond - morphology

Abstract: Provides researchers the latest data on the Arkhangelsk and Yakutian Diamondiferous Provinces in Russia. Enriches readers’ understanding of diamond geology and its evolution. Illustrates the complete process of diamond formation in the Archangelsk Diamondiferous Provinces.
DS200712-0728
2007
Samosorov, G.G.Mineeva, R.M., Speransky, A.V., Titkov, S.V., Solodova, Y.P., Samosorov, G.G.Paramagnetic N1 centre in plastically deformed and differently colored crystals of natural diamond.Doklady Earth Sciences, Vol. 415, 5, pp. 782-785.TechnologyDiamond morphology
DS200712-1014
2006
Samosorov, G.G.Solodova, Y.P., Sedova, E.A., Samosorov, G.G., Kurbatov, K.K.Comparative investigation of diamonds from various pipes in the Malaya Botuobiya and Daldyn Alakit areas, Siberia.Gems & Gemology, 4th International Symposium abstracts, Fall 2006, p.141-2. abstract onlyRussiaDiamond morphology
DS1995-1364
1995
Samotoin, N.D.Novgorodova, M.I., Samotoin, N.D., Magazina, L.O.Packing defect regularity in graphite from deep seated xenolithsDoklady Academy of Sciences, Vol. 334, No. 1, Aug., pp. 97-101.ChinaXenoliths, Deposit Tuvish pipe
DS2001-1005
2001
Samotoin, N.D.Samotoin, N.D.Mechanisms of layered spiral growth of synthetic diamond crystals based on scanning electron microscope (SEM) data.Doklady Academy of Sciences, Vol. 381, No. 8, Oct/Nov. pp. 925-8.GlobalDiamond - morphology, crystallography
DS200412-1725
2004
Samotoin, N.D.Samotoin, N.D.Morphology, intergrowths and growth mechanisms of diamond crystals at different stages of their formation from gases.Geochemistry International, Vol. 42, 2, pp. 134-144.TechnologyDiamond morphology
DS1960-1204
1969
Samoylov, V.S.Samoylov, V.S., Pozharitskaya, L.K.Temperature Facies of Metasomatites in Carbonatite Intrusions in Eastern Siberia.Doklady Academy of Science USSR, Earth Science Section., Vol. 188, No.1-6, PP. 173-176.RussiaKimberlite
DS1975-0544
1977
Samoylov, V.S.Kovalenko, V.I., Samoylov, V.S., et al.Rare Earths in Near Surface Carbonatite Complexes in MongoliGeochemistry International, PP. 148-158.GlobalCarbonatite, Rare Earth Elements (ree)
DS1975-0610
1977
Samoylov, V.S.Samoylov, V.S.Carbonatites; Facies and Genetic ConditionsMoscow: Nauka., 29LP.RussiaKimberlite, Kimberley
DS1982-0535
1982
Samoylov, V.S.Samoylov, V.S., Plyusnin, G.S.The Source of Material for Rare Earth CarbonatitesGeochemistry International, Vol. 19, No. 5, PP. 13-25.RussiaRelated Rocks
DS1982-0536
1982
Samoylov, V.S.Samoylov, V.S., Smirnova, YE.V.Rare Earth Behaviour in Carbonatite Formation and the Origin of Carbonatites.Geochemistry Internationa., No. 12, PP. 140-152.RussiaGeochemistry, Kimberlite
DS1983-0553
1983
Samoylov, V.S.Samoylov, V.S., Kovalenko, V.I.Alkalic and Carbonatite Complexes in MongoliaIzd. Trudy Sovmestnaya Sov. Mongol. Nauk. Geol. Eksped., No. 35, 200P.Russia, MongoliaRelated Rocks
DS1983-0554
1983
Samoylov, V.S.Samoylov, V.S., Kovalenko, V.I., et al.New Type of Rare Metal Ore in Carbonatite ComplexesDoklady Academy of Sciences ACAD. NAUK USSR EARTH SCI. SECTION., Vol. 261, No. 1-6, PP. 97-100.RussiaRelated Rocks
DS1988-0607
1988
Samoylov, V.S.Samoylov, V.S., Kovalenko, V.I., Ivanov, V.G., Naumov, V.B.Immiscible carbonatite phases in alkalic rocks of the Mossogay Hudagcomplex, southern MongoliaDoklady Academy of Science USSR, Earth Science Section, Vol. 294, No. 1-6, October pp. 167-169RussiaCarbonatite, Mossogay Hudag
DS1989-1330
1989
Samoylov, V.S.Samoylov, V.S.Problems of geochemical classification of carbonatites.(Russian)Geochemistry International (Geokhimiya), (Russian), No. 9, September pp. 1282-1292RussiaCarbonatite
DS1989-1331
1989
Samoylov, V.S.Samoylov, V.S., Ronenson, B.M., Sobachenko, V.N.Geochemistry of alkalic palingenesis and the carbonatite formation associated with itDoklady Academy of Science USSR, Earth Science Section, Vol. 296, No. 1-6, pp. 207-210RussiaCarbonatite, Ilmen-Vishnevorogorsk belt
DS1990-1297
1990
Samoylov, V.S.Samoylov, V.S.Geochemical carbonatite classificationGeochemistry Int, Vol. 27, No. 4, pp.58-66RussiaCarbonatite, Geochemistry
DS1994-1520
1994
Samoylov, V.S.Samoylov, V.S.Carbonatite rock associations and their geochemical and ore featuresGeological Association of Canada (GAC) Abstract Volume, Vol. 19, p. PosterRussiaCarbonatite, Geochemistry
DS201412-0839
2014
Samoylovich, M.Skvortsova, V., Samoylovich, M., Belyanin, A.Phase composition of the contact surfaces of monocrystalline diamond and kimberlite.Goldschmidt Conference 2014, 1p. AbstractTechnologyMineralogy
DS201412-0840
2014
Samoylovich, M.Skvortsova, V., Samoylovich, M., Belyanin, A.Phase composition of the contact surfaces of polycrystalline diamond and kimberlite.Goldschmidt Conference 2014, 1p. AbstractTechnologyMineralogy
DS1975-0688
1978
Samoylovich, M.I.Belimenko, L.D., Shemanina, YE.I., Samoylovich, M.I.A Comparative Electron Microscopy Study of Natural Diamonds from the Urals and Yakutsk.Nov. Dannyye Miner. Sssr., No. 27, PP. 19-27.RussiaMicroprobe
DS1980-0058
1980
Samoylovich, M.I.Belimenko, L.D., Gorokov, S.S., Samoylovich, M.I.Characteristics of Real Structure of Small DiamondsTsnigri, No. 153, PP. 31-35.RussiaBlank
DS1980-0059
1980
Samoylovich, M.I.Belimenko, L.D., Polkanov, YU.A., Samoylovich, M.I.Electron Microscopic Research on Diamonds from Titaniferous placers on the Russian PlatformTsnigri, No. 153, PP. 36-43.RussiaBlank
DS1988-0608
1988
Samoylovich, M.I.Samoylovich, M.I., Laptev, V.A.The deformational interactions of impurities and structural defects within the crystallattice of diamond.(Russian)Izv. Akad. Nauk SSSR, (Russian), Vol. 24, No. 8, pp. 1379-1381RussiaDiamond morphology, Diamond crystallography
DS201601-0044
2015
Samoylovich, M.I.Skvortsova, V.L., Samoylovich, M.I., Belyanin, A.F.Studies of phase composition of contact sites of diamond crystals and surrounding rocks.Doklady Earth Sciences, Vol. 465, 1, pp. 1187-1190.RussiaDeposit - Udachnaya

Abstract: The composition, structure, and morphology of iron-containing diamond-kimberlite contact sites were studied by means of scanning electron microscopy and Raman spectroscopy. The data obtained confirm the hypothesis of the similarity of mechanisms of diamond formation in nature and in experiments.
DS2000-0196
2000
SampaioCunha, J.C., Mascarenhas, Silva, Garrido, SampaioIntegrated airborne geophysical and geological studies of the Mundo Novo greenstone belt, Bahia, Brasil.Igc 30th. Brasil, Aug. abstract only 1p.Brazil, BahiaCraton - Sao Francisco, Mobile belt
DS1997-1089
1997
Sampaio, C.H.Souza, J.C., Sampaio, C.H.Technical and economical studies on the industrialization of precious stones in southern Brasil17th. World Mining Congress Oct. Mexico, pp. 115-125BrazilGemstones
DS1990-0286
1990
Sampaio, E.E.S.Carrion, P.M., Sampaio, E.E.S.Imaging the earth- the quest for resolutionGeophysics -The Leading Edge of Exploration, Vol. No. 10, October pp. 30-40GlobalOverview of conference workshop, Geophysics- seismics
DS201706-1103
2017
Sampaio, E.E.S.Sampaio, E.E.S., Barbosa, J.S.F., Corrrea-Gomes, L.C.New insight on the paleoproterozoic evolution of the Sao Francisco craton: reinterpretation of the geology, the suture zones and the thicknesses of the crustal blocks using geophysical and geological data.Journal of South American Earth Science, Vol. 76, pp. 290-305.South America, Brazilcraton - Sao Francisco

Abstract: The Archean-Paleoproterozoic Jequié (JB) and Itabuna-Salvador-Curaçá (ISCB) blocks and their tectonic transition zone in the Valença region, Bahia, Brazil are potentially important for ore deposits, but the geological knowledge of the area is still meager. The paucity of geological information restricts the knowledge of the position and of the field characteristics of the tectonic suture zone between these two crustal segments JB and ISCB. Therefore, interpretation of geophysical data is necessary to supplement the regional structural and petrological knowledge of the area as well as to assist mining exploration programs. The analysis of the airborne radiometric and magnetic data of the region has established, respectively, five radiometric domains and five magnetic zones. Modeling of a gravity profile has defined the major density contrasts of the deep structures. The integrated interpretation of the geophysical data fitted to the known geological information substantially improved the suture zone (lower plate JB versus upper plate ISCB) delimitation, the geological map of the area and allowed to estimate the thicknesses of these two blocks, and raised key questions about the São Francisco Craton tectonic evolution.
DS1997-0022
1997
Sampalo, A.S.Almeida, C.N., Beurlen, H., Sampalo, A.S.High pressure metamorphosed iron Ti ore hosting island arc tholeiites at Itatuba Paraiba as an indication -International Geology Review, Vol. 39, No. 7, July, pp. 589-608BrazilProterozoic suture Pajeu-Paraiba fold belt, Bororema Province
DS1996-1332
1996
Sampson, D.E.Smith, R.D., Cameron, K.L., Sampson, D.E.Generation of voluminous silicic magmas and formation of mid-Cenozoic crust beneath N-C Mexico: mantle..Contributions to Mineralogy and Petrology, Vol. 123, No. 4, pp. 375-389MexicoMantle magmas, Ignimbrites, granulites
DS1950-0151
1953
Sampson, D.N.Sampson, D.N.The Volcanic Hills of IgwisiGeological Survey Tanganyika Records, Vol. 3, PP. 49-53.Tanzania, East AfricaGeology, Related Rocks
DS201606-1112
2016
SAMRECSAMRECSAMREC guideline document for the reporting of diamond exploration results, diamond resources and diamond reserves ( and other gemstones, where relevant).SAMREC, 21p. Pdf availableTechnologySAMREC guidelines
DS2002-1392
2002
Samset, I.Samset, I.Conflicts of interests in conflict? Diamonds and war in the DRCReview of African Political Economy, No. 93/94, pp. 463-80. Ingenta 1025313754Democratic Republic of CongoLegal - economy, Conflict diamonds
DS1989-1332
1989
Samson, C.Samson, C., West, G.F.Correction of GLIMPCE deep reflection seismic dat a from Eastern Lake Superior for bottom lake topographyCentral Canada Geological Conference, A forum for current graduate, p. 58. (Abstract only)Ontario, MidContinentGeophysics, GLIMPCE.
DS1992-1325
1992
Samson, C.Samson, C., West, G.F.Crustal structure of the Midcontinent rift system in eastern Lake Superior:GLIMPCE deep reflection seismicsCanadian Journal of Earth Sciences, Vol. 29, pp. 636-49.OntarioGeophysics - seismics, Tectonics - rifting
DS1994-1521
1994
Samson, C.Samson, C., West, G.F.Detailed basin structure, tectonic evolution Midcont. Rift System e Lake superior reprocessing GLIMPCE.Canadian Journal of Earth Sciences, Vol. 31, No. 4, April pp. 629-639Ontario, MichiganGeophysics -seismics, GLIMPCE data, Tectonics -Midcontinent rift
DS1994-1522
1994
Samson, C.Samson, C., West, G.F.Detailed basin structure and tectonic evolution of the Midcontinent Rift system E. Lake Superior from GLIMPCE.Canadian Journal of Earth Sciences, Vol. 31, No. 4, April pp. 629-639.Ontario, MichiganGeophysics -seismics, reflection, Tectonics -Midcontinent rift
DS201312-0127
2014
Samson, C.Caron, R.M., Samson, C., Straznicky, P., Ferguson, S., Sander, L.Aeromagnetic surveying using a simulated unmanned aircraft system. ( not specific to diamonds)Geophysical Prospecting, Vol. 62, 2, pp. 352-363.Canada, OntarioGeophysics - aeromagnetics
DS201712-2705
2017
Samson, C.McPeak, S., Mallozzi, S., Samson, C., Elliott, B., Junter, J.Estimating overburden depth in a permafrost rich environment using passive seismics: results from the 2017 preliminary survey at Kennady Camp.45th. Annual Yellowknife Geoscience Forum, p. 103 abstract posterCanada, Northwest Territoriesdeposit - Kennady
DS201812-2850
2018
Samson, C.McPeak, S., Samson, C., Lamontagne, M., Elliott, B.Application of passive seismic methodologies to the determination of overburden thickness.2018 Yellowknife Geoscience Forum , p. 111-112. abstractCanada, Northwest Territoriesgeophysics - seismics

Abstract: Diamond mining is central to the economic development of the Canadian North. Innovative methods are needed to identify new prospective targets, as many of them are hidden beneath a thick overburden of glacial sediments. Passive seismics is an emerging method used to map the thickness of near-surface geological layers. Vibrations from distant earthquakes are used as a source of signal and data is processed to estimate the depth of the interface between the overburden and the underlying bedrock. In July 2018, four Tromino seismographs were taken to a study site located approximately ten minutes driving north of Yellowknife. A total of 146 Tromino measurements and associated GPS elevation measurements were taken at 6 m intervals along a dirt road. Elevation measurements were averaged over the course of four days and the survey line was approximately 740 m long. Results indicated that depth to bedrock decreases near outcrops and increases in valleys however; another geophysical dataset is needed to validate the passive seismic data.
DS201212-0619
2012
Samson, I.Samson, I.The geochemistry of fluid mediated processes in the formtion of rare element deposits in silicic alkaline systems.Gordon Research Centre Conference July 15-20, AbstractTechnologyAlkalic
DS1991-1000
1991
Samson, I.M.Liu Weining, Samson, I.M., Williams-Jones, A.E.The nature of hydrothermal fluids in carbonatites: evidence from primary fluid inclusions in apatite, Oka, QuebecGeological Society of America Annual Meeting Abstract Volume, Vol. 23, No. 5, San Diego, p. A 148QuebecCarbonatite, Fluid inclusions
DS1995-1653
1995
Samson, I.M.Samson, I.M., Liu, W., Williams-Jones, A.E.The nature of orthomagmatic hydrothermal fluids in the Oka carbonatite, Quebec -evidence from fluid inclusionsGeochimica et Cosmochimica Acta, Vol. 59, No. 10, pp. 1963-1977.QuebecCarbonatite, Deposit -Oka
DS1995-1654
1995
Samson, I.M.Samson, I.M., Williams, A.E., Liu, W.N.The chemistry of hydrothermal fluids in carbonatites -evidence from leachate and sem-decrepitate analysis.Geochimica et Cosmochimica Acta, Vol. 59, No. 10, May pp. 1979-1989.QuebecCarbonatite, Deposit -Oka
DS1995-1655
1995
Samson, I.M.Samson, I.M., Williams-Jones, A.E., Weining LiuThe chemistry of hydrothermal fluids in carbonatites: evidence from leachate and scanning electron microscope (SEM)-decriptate analysis Oka.Geochimica et Cosmochimica Acta, Vol. 59, No. 10, pp. 1979-1989.QuebecCarbonatite, geochemistry, Deposit -Oka
DS201212-0785
2012
Samson, I.M.Williams-Jones, A.E., Migdisov, A.A., Samson, I.M.Hydrothermal mobilisation of the rare earth elements - a tale of "ceria" and "yttria".Elements, Vol. 8, 5, Oct. pp. 355-360.GlobalGeochemistry, UHP, transport and deposition
DS201612-2284
2016
Samson, I.M.Cao, Y.H., Linnen, R.L., Good, D.J., Samson, I.M., Epstein, R.The application of portable XRF and benchtop SEM-EDS to Cu-Pd exploration in the Coldwell alkaline complex, Ontario, Canada.Geochemistry: Exploration, Environment, Analysis, Vol. 16, 3-4, pp. 193-212.Canada, OntarioAlkalic

Abstract: Mineral exploration is increasingly taking advantage of real time techniques that dramatically reduce the costs and time taken to obtain results compared to traditional analytical methods. Portable X-ray fluorescence (pXRF) is now a well-established technique that is used to acquire lithogeochemical data. To date, however, benchtop scanning electron microscopes, equipped with energy dispersive systems (bSEM-EDS) have received little attention as a possible mineral exploration tool. This study examines the utility of combining pXRF and bSEM-EDS to characterize the igneous stratigraphy and its relationship to Cu-Pd mineralization in a drill hole at the Four Dams occurrence, located within the Eastern Gabbro assemblage of the Coldwell Alkaline Complex, Canada. The first part of this study compares field portable and laboratory techniques. Seventy-two powdered samples analysed by pXRF are compared with traditional major elements analysed by inductively coupled atomic emission spectroscopy (ICP-AES) and trace elements by inductively coupled plasma spectrometry (ICP-MS), and the compositions of 128 olivine, clinopyroxene and plagioclase grains analysed by bSEM-EDS are compared with traditional electron microprobe data. Our results show that each portable technique yields results similar to their lab-based counterparts within the analytical capabilities and precisions of the respective instruments. The second part presents a case study for the application of pXRF and bSEM-EDS to resolve questions related to igneous stratigraphy as an aid to mineral exploration in a complicated geological setting. A major problem for Cu-Pd exploration in the Coldwell Complex of NW Ontario is that the oxide-rich units that host Cu-Pd mineralization in the Marathon Series are petrographically similar to the barren oxide-rich units in the Layered Series. However, the mineralized units are geochemically distinctive. Our results show that the mineralized Marathon Series can be distinguished from the barren Layered Series, including oxide-rich units of both, by combinations of P2O5, Ba, Zr and V/Ti values, determined by pXRF, combined with plagioclase, olivine or clinopyroxene compositions measured by bSEM-EDS. The combination of pXRF and bSEM-EDS thus shows considerable promise as an exploration technique.
DS202104-0567
2021
Samson, I.M.Brzozowski, M., Samson, I.M., Gagnon, J.E., Linnen, R.L., Good, D.J.Effects of fluid-induced oxidation on the composition of Fe-Ti oxides in the eastern gabbro, Coldwell Complex, Canada: implications for the application of Fe-Ti oxides to petrogenesis and mineral exploration.Mineralium Deposita, Vol. 56, pp. 601-618. pdfCanada, Ontariodeposit - Coldwell

Abstract: Magnetite (mag)-ilmenite (ilm) intergrowths are more common than mag-ulvöspinel (usp) intergrowths in mafic-ultramafic Ni-Cu-PGE systems, yet the former has no known solid solution. The most accepted model for the formation of mag-ilm intergrowths in terrestrial environments is fluid-induced oxidation of mag-usp assemblages by oxygen in water. In this study, we re-examine this model in light of the fact that crustal fluids have very low pO2 and that mag-ilm intergrowths commonly occur in rocks that show little or no evidence of hydrothermal alteration. We also characterize the chemical changes that occurred during the formation of mag-ilm intergrowths and how they affect the use of Fe-Ti oxide chemistry for petrogenesis and mineral exploration. In the Eastern Gabbro, Coldwell Complex, a continuum of Fe-Ti oxide intergrowths occur ranging from cloth (mag-usp) to trellis (mag-ilm) types. Trellis-textured intergrowths have higher bulk Fe3+:Fe2+ ratios and are predominantly enriched not only in some multivalent (Ge, Mo, W, Sn) elements, but also in Cu and Ga, consistent with their formation via oxidation by a metal-rich fluid. These compositional changes are significant relative to typical elemental abundances in Fe-Ti oxides and could potentially lead to erroneous interpretations regarding primary magmatic processes if they are not taken into consideration. The irregular distribution of the intergrowths throughout the Eastern Gabbro suggests that different rock series and mineralized zones experienced variable degrees of fluid-induced oxidation. It is proposed that C in CO2 rather than O2 in water could potentially be an important oxidizing agent in mafic systems: 9Fe2+2TiO4+0.75CO2+1.5H2O?9Fe2+TiO3+3Fe3+2Fe2+O4+0.75CH4. The applicability of this model is supported by the common occurrence of CO2 and CH4 in fluid inclusions in mafic rocks.
DS202104-0568
2021
Samson, I.M.Brzozowski, M.J., Samson, I.M., Gagnon, J.E., Good, D.J., Linnen, R.L.Oxide mineralogy and trace element chemistry as an index to magma evolution and Marathon-type mineralization in the eastern gabbro of the alkaline Coldwell Complex, Canada.Mineralium Deposita, Vol. 56, pp. 621-642. pdfCanada, Ontariodeposit - Coldwell

Abstract: The Eastern Gabbro of the alkaline Coldwell Complex, Canada, represents a Ni-poor conduit-type system that comprises two rock series, the Layered Series and Marathon Series, which intruded into a metabasalt package. Based on distinct variations in magnetite compatible (e.g., Ni, Cr) and incompatible (e.g., Sn, Nb) elements in Fe-Ti oxide intergrowths, the metabasalts, Layered Series, and Marathon Series must have crystallized from magmas that originated from compositionally distinct sources. Of these rock units, the metabasalts crystallized from a more primitive melt than the Layered Series as Fe-Ti oxides in the former have higher concentrations of magnetite-compatible elements. Unlike the metabasalts and Layered Series, the Marathon Series crystallized from multiple, compositionally distinct magmas as Fe-Ti oxides in this series exhibit large variations in both magnetite compatible and incompatible elements. Accordingly, the various rock types of the Marathon Series cannot be related by fractional crystallization of a single batch of magma. Rather, the magmas from which the rock types crystallized had to have interacted to variable degrees with a late input of more primitive melt. The degree of this magma interaction was likely controlled by the geometry of the conduit and the location of emplacement given that Fe-Ti oxides in the oxide-rich rocks occur in pod-like bodies and exhibit no compositional evidence for magma mixing. Mirrored variations in magnetite compatible and incompatible elements in Fe-Ti oxides in the Footwall Zone, Main Zone, and W Horizon of the Marathon Cu-PGE deposit indicate that these zones could not have formed from a single, evolving magma, but rather multiple batches of compositionally distinct magmas. Fe-Ti oxides exhibit no compositional difference between those hosted by barren and mineralized rock. This is likely because sulfide liquated at depth in all of the magmas from which the Marathon Series crystallized. The composition of Fe-Ti oxides in the Eastern Gabbro fall outside of the compositional fields for Ni-Cu mineralization defined by Dupuis and Beaudoin (Mineral Deposita 46:319-335, 2011) and Ward et al. (J Geochem Explor 188:172-184, 2018) demonstrating that their discrimination diagrams can distinguish between Ni-rich and Ni-poor systems that contain disseminated and massive sulfides.
DS1984-0627
1984
Samson, J.Samson, J.An overview of coastal and marine gold placer occurrences in Nova Scotia and British ColumbiaEnergy Mines and Resources, Ocean Mining Division, No. 1984-3, 178p. MINTEC MNG 37334British ColumbiaPlacers
DS1989-1333
1989
Samson, S.D.Samson, S.D., McClelland, W.C., Patchett, P.J., Gehrels, G.E.Evidence from neodynium isotopes for mantle contributions to Phanerozoiccrustal genesis in the Canadian CordilleraNature, Vol. 337, No. 6209, Feb. 23, pp. 705-708CordilleraIsotope, Mantle genesis
DS1990-1298
1990
Samson, S.D.Samson, S.D., Patchett, P.J., Gehrels, G.E., Anderson, R.G.neodymium and Strontium isotopic characterization of the Wrangellia Terrane and implications for crustal growth of the Canadian CordilleraJournal of Geology, Vol. 98, pp. 749-762British ColumbiaTerrane - Wrangellia, Geochronology
DS1991-1495
1991
Samson, S.D.Samson, S.D., Patchett, P.J.The Canadian Cordillera as a modern analogue of Proterozoic crustalgrowthAustralian Journal of Earth Sciences, Vol. 38, December pp. 595-611Canada, British Columbia, Alaska, YukonCrust, Terranes - regional geology
DS1995-1656
1995
Samson, S.D.Samson, S.D., Hibbard, J.P., Wortman, G.L.neodymium isotopic evidence for juvenile crust in the Carolin a Terrane, southernAppalachiansContributions to Mineralogy and Petrology, Vol. 121, No. 2, pp. 171-184Appalachia, CarolinasGeochronology, Tectonics
DS200912-0060
2009
SamsonovBogatikov, O.A., Sharkov, E.V., Bogina, Kononova, Nosova, Samsonov, ChistyakovWithin plate (intracontinental) and postorogenic magmatism of the East European Craton as reflection of the evolution of continental lithosphere.Petrology, Vol. 17, 3, May pp. 207-226.RussiaMagmatism
DS200912-0660
2009
Samsonov, A.A.V.A.Samsonov, A.A.V.A., Nosova, A.A.A.A., Tretyachenko, V.A.V.A., Larchenko, V.A.A.A., Larionova, Y.A.O.A.Collisional sutures in the early Precambrian crust as a factor for localization of Diamondiferous kimberlites in the northern east European platform.Doklady Earth Sciences, Vol. 425, 2, pp. 226-230.RussiaTectonics
DS201212-0620
2012
Samsonov, A.V.Samsonov, A.V., Tretyachenko, W., Nosova, A.A., Larionova, Yu.O., Lepekhina, E.N., Larionov, A.N., Ipatieva, I.S.Sutures in the early Precambrian crust as a factor responsible for localization of Diamondiferous kimberlites in the northern east European platform.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractRussia, Kola PeninsulaStructure
DS201312-0334
2013
Samsonov, A.V.Griban, J.G., Samsonov, A.V., Salnikov, E.B., Lepehina, E.N.Kimberlitic zircons from the Paleoproterozoic Kimzero kimberlites ( Karelia): mineralogy, geochemistry and U-Pb geochronology.Goldschmidt 2013, AbstractRussia, KareliaDeposit - Kimozero
DS201312-0775
2013
Samsonov, A.V.Samsonov, A.V., Griban, J.G., Larionova, Y.O., Nosova, A.A., Tretyachenko, V.V.Evolution of deep crustal roots of the Arhangelsk Diamondiferous province: evidences from crustal xenoliths and xenocrysts from Devonian kimberlite pipes.Goldschmidt 2013, 1p. AbstractRussia, Kola PeninsulaDeposit - Arkangel
DS201908-1820
2019
Samsonov, A.V.Veselovskiy, R.V., Thomson, S.N., Arzamastsev, A.A., Botsyun, S.B., Travin, A.V., Yudin, D.S., Samsonov, A.V., Stepanova, A.V.Thermochronology and exhumation history of the northeastern Fennoscandian Shield since 1.9 Ga: evidence from 40AR/39Ar and apatite fission track data from the Kola Peninsula.Tectonics, doi.org/10.1029 /2018TC005250Europe, Kola Peninsulageochronology

Abstract: Results from thermochronological studies have multiple applications to various problems in tectonics and landform evolution However, up to now a lack of thermochronological data from the northeastern Fennoscandian Shield has complicated the interpretation of tectonothermal evolution of the region Here, we use both new and previously published multimineral 40Ar/39Ar data (amphibole, mica, and feldspar) on the various Precambrian magmatic and metamorphic complexes to reconstruct the thermal history of NE Fennoscandia within the Kola Peninsula area in the interval 1900–360 Ma Using the apatite fission track method as well as a numerical model of the heating?cooling process of northeastern Fennoscandia's upper crust, we have reconstructed its thermal evolution for the interval 360–0 Ma According to our model, since Lapland?Kola orogenesis (1930–1905 Ma) northeastern Fennoscandia experienced a quasi?monotonous cooling with the average rate of ~0 15 °C/Myr, which is equal to an exhumation rate of ~1–2 m/Myr New apatite fission track data and time?temperature modeling reveal a “hidden” endogenous thermal event in the NE Fennoscandia that took place between 360 and 300 Ma This we attribute to an elevated geothermal gradient due to Baltica's drift over the African large low shear?wave velocity province in the lowest mantle and/or thermal blanketing by insulating Devonian?Carboniferous sedimentary/volcanic cover Our model is further supported by evidence of Late Devonian?Carboniferous rifting in the East and South?Western Barents Basin, as well as various 360–300 Ma magmatic events within SW Fennoscandia and the Baltic countries
DS201909-2103
2019
Samsonov, A.V.Veselovskiy, R.V., Thomson, S.N., Arzamastsev, A.A., Botsyun, S., Travin, A.V., Yudin, D.S., Samsonov, A.V., Stepanova, A.V.Thermochronology and exhumation history of the northeastern Fennoscandian shield since 1.9 Ga: evidence from 40Ar/39/Ar and apatite fission track data from the Kola Peninsula.Tectonics, Vol. 38, 7, pp. 2317-2337.Europe, Fennoscandia, Kola Peninsulageochronology

Abstract: Results from thermochronological studies have multiple applications to various problems in tectonics and landform evolution. However, up to now a lack of thermochronological data from the northeastern Fennoscandian Shield has complicated the interpretation of tectonothermal evolution of the region. Here, we use both new and previously published multimineral 40Ar/39Ar data (amphibole, mica, and feldspar) on the various Precambrian magmatic and metamorphic complexes to reconstruct the thermal history of NE Fennoscandia within the Kola Peninsula area in the interval 1900-360 Ma. Using the apatite fission track method as well as a numerical model of the heating?cooling process of northeastern Fennoscandia's upper crust, we have reconstructed its thermal evolution for the interval 360-0 Ma. According to our model, since Lapland?Kola orogenesis (1930-1905 Ma) northeastern Fennoscandia experienced a quasi?monotonous cooling with the average rate of ~0.15 °C/Myr, which is equal to an exhumation rate of ~1-2 m/Myr. New apatite fission track data and time?temperature modeling reveal a “hidden” endogenous thermal event in the NE Fennoscandia that took place between 360 and 300 Ma. This we attribute to an elevated geothermal gradient due to Baltica's drift over the African large low shear?wave velocity province in the lowest mantle and/or thermal blanketing by insulating Devonian?Carboniferous sedimentary/volcanic cover. Our model is further supported by evidence of Late Devonian?Carboniferous rifting in the East and South?Western Barents Basin, as well as various 360-300 Ma magmatic events within SW Fennoscandia and the Baltic countries.
DS202007-1177
2020
Samsonov, A.V.Salnikova, E.B., Samsonov, A.V., Stepanova, A.V., Veselovskiy, R.V., Egorova, S.V., Arzamastsev, A.A., Erofeeva, K.G.Fragments of Paleoproterozoic large igneous provinces in northern Fennoscandia: baddeleyite U-Pb age data for mafic dykes and sills.Doklady Earth Sciences, Vol. 491, pp. 227-230.Europe, Russia, Kola Peninsulageochronology

Abstract: New data on the age of dolerite dikes in the NE part of the Kola province of the Fennoscandinavian shield and the picrodolerite sills that cut the dikes are presented. The results of U-Pb ID-TIMS baddeleyite dating indicate that dolerites were formed between 2508 ± 6 and 2513 ± 16 Ma ago, simultaneously with the intrusions of the Monchegorsk group. A comparison of the composition of the dolerites studied with dykes of the same age found in other Archean cratons shows their significant similarity and suggests their formation at the same large magmatic province. The age of baddeleyite from the picrodolerites sills at 2403 ± 12 Ma ago indicates an event of basic magmatism that was not previously established in this part of the Fennoscandinavian shield. It is possible that, along with dolerite dykes with an age of 2405 Ma and komatiites of the Vetreny belt of the Karelian craton, sills of the Kola province are a component of a unified large magmatic event.
DS202009-1608
2019
Samsonov, A.V.Arzamastev, A., Stepanova, A.V., Samsonov, A.V., Erofeev, K.G.Mafic magmatism of northeastern Fennoscandia ( 2.06-1.86 Ga) geochemistry of volcanic rocks and correlation with dike complexes.Stratigraphy and Geological Correlation, Vol. 28, 1, pp. 1-34.Europe, Fennoscandiamagmatism

Abstract: The comprehensive geochemical and isotopic-geochronological study of Early Proterozoic volcanic rocks in structure of the Polmak-Pechenga-Imandra-Varzuga belt and dikes and sills of the Murmansk and Kola-Norwegian terranes is conducted. Abundant swarms of mafic dikes (2.06-1.86 Ga) are established in the northwestern frame of the belt, including swarms of metadolerites (2060 ± 6 Ma), ferropicrites and gabbronorites (1983 ± 5 Ma), and poikilophitic dolerites (1860 ± 4 Ma). The comparison of volcanic rocks of the Pechenga and Imandra-Varzuga structures shows asynchronous change in volcanism style, with a significant time lapse. The geochemical features of volcanic rocks of the Tominga Formation are typical of those of continental magmatism and can hardly be correlated with those of the Pilguyarvi Formation. According to isotopic-geochronological data, depleted mantle melts in the Pechenga and Imandra-Varzuga zones intruded at 2010-1970 and 1970-1980 Ma, respectively. The analysis of the conditions of formation of volcanic series shows that Neoarchean lithospheric mantle, which produced melts with low Zr/Nb ratios, was a source for primary melts of the Kuetsjarvi Formation of the Pechenga structure and their homologs of the Imandra-Varzuga structure. In contrast, the volcanic rocks of the Kolasjoki Formation, which were weakly contaminated with crustal material, and the related Ilmozero Formation, as well as the metadolerite dikes of the Kirkenes region, were sourced mostly from asthenosphere with separation of melt above the garnet stability depth. The formation of the volcanic rocks of the Pilguyarvi Formation is related, judging from the geochemical data, to two asthenospheric sources different in depth, which produced tholeiitic and ferropicritic melts.
DS202010-1843
2020
Samsonov, A.V.Erofeeva, K.G., Samsonov, A.V., Stepanova, A.V., Larionova, Yu.O., Dubinina, E.O., Egorova, S.V., Arzamastesev, A.A., Kovalchuk, E.V., Abramova, V.D.Olivine and clinopyroxene phenocrysts as a proxy for the origin and crustal evolution of primary mantle melts: a case study of 2.40 Ga mafic sills in the Kola-Norwegian Terrane, northern Fennoscandia.Petrology, Vol. 28, 4, pp. 338-356. pdfEurope, Norway, Kola Peninsulamelting

Abstract: New petrographic, geochemical, and isotopic (Sr, Nd, and ?18?) data on olivine and pyroxene phenocrysts provide constraints on the composition and crustal evolution of primary melts of Paleoproterozoic (2.40 Ga) picrodoleritic sills in the northwest Kola province, Fennoscandian Shield. The picrodolerites form differentiated sills with S-shaped compositional profiles. Their chilled margins comprise porphyritic picrodolerite (upper margin) and olivine gabbronorite (bottom) with olivine and clinopyroxene phenocrysts. Analysis of the available data allows us to recognize three main stages in the crystallization of mineral assemblages. The central parts of large (up to 2 mm) olivine phenocrysts (Ol-1-C) crystallized at the early stage. This olivine (Mg# 85-92) is enriched in Ni (from 2845 to 3419 ppm), has stable Ni/Mg ratio, low Ti, Mn and Co concentrations, and contains tiny (up to 10 ?m) diopside-spinel dendritic lamella that probably originated due to the exsolution from high Ca- and Cr- primary magmatic olivine. All these features of Ol-1-C are typical of olivine from primitive picritic and komatiitic magmas (De Hoog et al., 2010; Asafov et al., 2018). Ol-1-C contains large (up to 0.25 mm) crystalline inclusions of high-Al enstatite (Mg# 80-88) and clinopyroxene (Mg# 82-90), occasionally in association with Ti-pargasite and chromian spinel (60.4 wt.% Al2O3). These inclusions are regarded as microxenoliths of wall rock that were captured by primary melt at depths more than 30 km and preserved due to the conservation in magmatic olivine. The second stage was responsible for the crystallization of Ol-1 rim (Ol-1-R), small (up to 0.3 mm) olivine (Ol-2, Mg# 76-85) grains, and central parts of large (up to 1.5 mm) clinopyroxene (Cpx-C) phenocrysts in the mid-crustal transitional magma chamber (at a depth of 15-20 km) at 1160-1350°C. At the third stage, Cpx-C phenocrysts were overgrown by low-Mg rims (Mg# 70-72) similar in composition to the groundmass clinopyroxene from chilled picrodolerite and gabbro-dolerite in the central parts of the sills. This stage likely completed the evolution of picrodoleritic magma and occurred in the upper crust at a depth of about 5 km. All stages of picrodoleritic magma crystallization were accompanied by contamination. Primary melts were contaminated by upper mantle and/or lower crust as recognized from xenocrystic inclusions in Ol-1-C. The second contamination stage is supported by the negative values of ?Nd(2.40) = -1.1 in clinopyroxene phenocrysts. At the third stage, contamination likely occurred in the upper crust when ascending melts filled gentle fractures. This caused vertical whole-rock Nd heterogeneity in the sills (Erofeeva et al., 2019), and difference in Nd isotopic composition of clinopyroxene phenocrysts and doleritic groundmass. It was also recognized that residual evolved melts are enriched in radiogenic strontium but have neodymium isotopic composition similar to other samples. It could be explained by the interaction of the melts with fluid formed via decomposition of biotite from surrounding gneisses under the effect of high-temperature melts.
DS202107-1126
2021
Samsonov, A.V.Savko, K.A., Tsybulyaev, S.V., Samsonov, A.V., Bazikov, N.S., Korish, E.H., Terentiev, R.A., Panevin, V.V.Archean carbonatites and alkaline rocks of the Kursk Block, Sarmatia: age and geodynamic setting.Doklady Earth Sciences, Vol. 498, 1, pp. 412-417.Russiacarbonatite

Abstract: Neoarchean intraplate granitoid (2.61 Ga) and carbonatite magmatism are established in the Kursk block of Sarmatia in close spatial association. Alkaline pyroxenites, carbonatites, and syenites of the Dubravinskii complex are represented by two relatively large intrusions and a few small plutons. They underwent amphibolite facies metamorphism at about 2.07 Ga. The age of alkaline-carbonatite magmatism is 2.59 Ga according to SIMS isotope dating of zircon from syenites. The close age and spatial conjugation allow the Dubravinskii carbonatite complex to be considered to have formed in intraplate conditions. The mantle plume upwelling caused metasomatic alteration and consequent partial melting of the sublithospheric mantle and intrusion of enriched magmas into the crust. Contamination of alkaline mantle melts in the crust by Archean TTGs caused the formation of syenites melts in the form of dykes that cutting through pyroxenites and carbonatites.
DS200412-1363
2004
Samsonov, M.D.Moralev, V.M., Samsonov, M.D.A tectonic interpretation of petrochemical signatures of Proterozoic and Paleozoic alkaline rocks from the Porjaguba dyke swarm,Geotectonics, Vol. 38, 2, pp. 102-111.RussiaAlkalic
DS1981-0358
1981
Samsonov, YA.P.Samsonov, YA.P., Turinge, A.P.The Geology and Prospects of Developing Deposits of Quartz, iceland Spar and Gems in Siberia and the Far East.Soviet Geology And Geophysics, Vol. 22, No. 7, PP. 11-17.RussiaDiamonds
DS200612-0524
2006
SAMTEX MTHamilton, M.P., Jones, A.G., Evans, R.L., Evans, S., Fourie, C.J.S., Garcia, X., Mountford, A., Spratt, J.E., SAMTEX MTElectrical anisotropy of South African lithosphere compared with seismic anisotropy from shear wave splitting analyses.Physics of the Earth and Planetary Interiors, In press, availableAfrica, South AfricaGeophysics - magnetotellurics
DS2003-0392
2003
Samuel, H.Farnetani, C.G., Samuel, H.Lagrangian structures and stirring in the Earth's mantleEarth and Planetary Science Letters, Vol. 206, No. 3-4, pp. 335-48.MantleTectonics
DS2003-1209
2003
Samuel, H.Samuel, H., Farnetani, C.G.Thermochemical convection and helium concentrations in mantle plumesEarth and Planetary Science Letters, Vol. 207, 1-4, pp. 39-56.MantleMineral chemistry
DS2003-1210
2003
Samuel, H.Samuel, H., Farnetani, C.G.Thermochemical convection and helium concentrations in mantle plumesEarth and Planetary Science Letters, Vol. 207, 1-4, Feb. 28, pp. 39-56.MantleThermometry, Convection
DS200512-0279
2005
Samuel, H.Farnetani, C.G., Samuel, H.Beyond the thermal plume paradigm.Geophysical Research Letters, Vol. 32, no. 7, L07311 doi:10.1029/2005 GL022360MantleGeothermometry
DS200612-1213
2005
Samuel, H.Samuel, H., Farnetani, C.G., Andrault, D.Heterogeneous lowermost mantle: compositional constraints and seismological observables.American Geophysical Union, Geophysical Monograph, Ed. Van der Hilst, Earth's Deep Mantle, structure ...., No. 160, pp. 101-116.MantleGeophysics - seismics
DS201212-0621
2012
Samuel, H.Samuel, H., Tosi, N.The influence of post-perovskite strength on the Earth's mantle thermal and chemical evolution.Earth and Planetary Science Letters, Vol. 323-324, pp. 50-59.MantleGeothermometry
DS201702-0228
2017
Samuel, V.O.Milani, L., Bolhar, R., Frei, D., Harlov, D.E., Samuel, V.O.Light rare earth element systematics as a tool for investigating the petrogenesis of phoscorite-carbonatite associations, as exemplified by the Phalaborwa Complex, South Africa.Mineralium Deposita, in press available, 21p.Africa, South AfricaDeposit - Phalaborwa

Abstract: In-situ trace element analyses of fluorapatite, calcite, dolomite, olivine, and phlogopite have been undertaken on representative phoscorite and carbonatite rocks of the Palaeoproterozoic Phalaborwa Complex. Textural and compositional characterization reveals uniformity of fluorapatite and calcite among most of the intrusions, and seems to favor a common genetic origin for the phoscorite-carbonatite association. Representing major repositories for rare earth elements (REE), fluorapatite and calcite exhibit tightly correlated light REE (LREE) abundances, suggesting that partitioning of LREE into these rock forming minerals was principally controlled by simple igneous differentiation. However, light rare earth element distribution in apatite and calcite cannot be adequately explained by equilibrium and fractional crystallization and instead favors a complex crystallization history involving mixing of compositionally distinct magma batches, in agreement with previously reported mineral isotope variability that requires open-system behaviour.
DS1987-0055
1987
Samuelson, A.C.Bily, D., Samuelson, A.C.Studies of magnetic anomalies in east central Indiana and possible geomorphic expressionGeological Society of America, Vol. 19, No. 3, p. abstractIndianaUSA, Geophysics
DS200512-0919
2004
Samygin, S.G.Ruzhentsev, S.V., Samygin, S.G.The structure and tectonic evolution of the East European Platform and the southern Urals junction zone.Geotectonics, Vol. 38, 4, pp. 255-276.Russia, UralsTectonics
DS200512-0930
2006
Samykina, E.V.Samykina, E.V., Surkov, A.V., Epplebaum, L.V., Semenov, S.V.Do old spoils contain large amounts of economically valuable minerals?Minerals Engineering, Vol. 18, 6, May, pp. 643-645. Note only 2 pagesRussia, Africa, South Africa, South AmericaGravity concentration, gold, diamonds
DS200712-0932
2005
Samykina, E.V.Samykina, E.V., Surkov, A.V., Eppelbaum, L.V., Semenov, S.V.Do old spoils contain large amounts of economically valuable minerals?Minerals Engineering, Vol. 18, 6, May pp. 643-645.Russia, AfricaMineral processing - gravel deposits
DS1860-0533
1887
San Francisco BulletinSan Francisco BulletinA California DiamondSan Francisco Bulletin., AUGUST 11TH.United States, California, West Coast, AmadorDiamond Occurrence
DS1860-0582
1888
San Francisco BulletinSan Francisco BulletinPrecious Stones, Diamonds, Rubies, Sapphires and Other Gemsin Georgia.San Francisco Bulletin., AUGUST 4TH.United States, GeorgiaGemology
DS1860-0828
1894
San Francisco BulletinSan Francisco BulletinDiamond Found in CaliforniaSan Francisco Bulletin, Dec. 12TH.United States, California, West Coast, El DoradoDiamond Occurrence
DS1900-0094
1902
San Francisco ChronicleSan Francisco ChronicleTiny Diamonds Discovered Near San Bernidino, CaliforniaSan Francisco Chronicle., Oct. 31ST.United States, California, West CoastDiamond Occurrence
DS1900-0508
1907
San Francisco ChronicleSan Francisco ChronicleTo Mine DiamondsSan Francisco Chronicle., JULY 26TH.United States, California, West CoastDiamond mining
DS1860-0729
1892
San Francisco ExaminerSan Francisco ExaminerSnake River DiamondsSan Francisco Examiner., Dec. 10TH.United States, Idaho, Central StatesDiamond Occurrence
DS1860-0732
1892
San Francisco ExaminerSan Francisco ExaminerIdaho's Diamond FieldsSan Francisco Examiner., Dec. 8TH.United States, Idaho, Rocky MountainsDiamond Occurrence
DS1860-0723
1892
San Francisco PostSan Francisco PostIdaho's Gems. Prospect for Big Diamond DiscoveriesSan Francisco Post., Dec. 9TH.; ROCKY MOUNTAINSUnited States, IdahoProspecting
DS201908-1780
2019
Sanan, P.Jain, C., Rozel, A.B., Tackley, P.J., Sanan, P., Gerya, T.V.Growing primordial continental crust self-consistently in global mantle convection models.Gondwana Research, Vol. 73, pp. 96-122.Mantlegeothermometry

Abstract: The majority of continental crust formed during the hotter Archean was composed of Tonalite-Trondhjemite-Granodiorite (TTG) rocks. In contrast to the present-day loci of crust formation around subduction zones and intra-plate tectonic settings, TTGs are formed when hydrated basalt melts at garnet-amphibolite, granulite or eclogite facies conditions. Generating continental crust requires a two step differentiation process. Basaltic magma is extracted from the pyrolytic mantle, is hydrated, and then partially melts to form continental crust. Here, we parameterise the melt production and melt extraction processes and show self-consistent generation of primordial continental crust using evolutionary thermochemical mantle convection models. To study the growth of TTG and the geodynamic regime of early Earth, we systematically vary the ratio of intrusive (plutonic) and eruptive (volcanic) magmatism, initial core temperature, and internal friction coefficient. As the amount of TTG that can be extracted from the basalt (or basalt-to-TTG production efficiency) is not known, we also test two different values in our simulations, thereby limiting TTG mass to 10% or 50% of basalt mass. For simulations with lower basalt-to-TTG production efficiency, the volume of TTG crust produced is in agreement with net crustal growth models but overall crustal (basaltic and TTG) composition stays more mafic than expected from geochemical data. With higher production efficiency, abundant TTG crust is produced, with a production rate far exceeding typical net crustal growth models but the felsic to mafic crustal ratio follows the expected trend. These modelling results indicate that (i) early Earth exhibited a "plutonic squishy lid" or vertical-tectonics geodynamic regime, (ii) present-day slab-driven subduction was not necessary for the production of early continental crust, and (iii) the Archean Earth was dominated by intrusive magmatism as opposed to "heat-pipe" eruptive magmatism.
DS201412-0773
2013
Sanata, E.F.Sanata, E.F., Weska, R.K.Placeres diamantiferos do Rio Itiquira, MT, Brasil.Boletim de Geosciencias, Vol. 68, pp. 26-35.South America, Brazil, Mato GrossoDiamond placers
DS201912-2821
2019
Sanatmaria-Perez, D.Sanatmaria-Perez, D., Ruiz-Fuertes, J., Pena-Alvarez, M., Chulia-Jordan, R., Marquerno, T., Zimmer, D., Guterrez-Cano, V., Macleod, S., Gregoryanz, E., Popescue, C., Rodriguez-Herandez, P., Munoz, A.Post-tilleyite, a dense calcium silicate carbonate phase.Nature Scientific Reports, Vol. 9, 11p. PdfMantletilleyite

Abstract: Calcium carbonate is a relevant constituent of the Earth’s crust that is transferred into the deep Earth through the subduction process. Its chemical interaction with calcium-rich silicates at high temperatures give rise to the formation of mixed silicate-carbonate minerals, but the structural behavior of these phases under compression is not known. Here we report the existence of a dense polymorph of Ca5(Si2O7)(CO3)2 tilleyite above 8 GPa. We have structurally characterized the two phases at high pressures and temperatures, determined their equations of state and analyzed the evolution of the polyhedral units under compression. This has been possible thanks to the agreement between our powder and single-crystal XRD experiments, Raman spectroscopy measurements and ab-initio simulations. The presence of multiple cation sites, with variable volume and coordination number (6-9) and different polyhedral compressibilities, together with the observation of significant amounts of alumina in compositions of some natural tilleyite assemblages, suggests that post-tilleyite structure has the potential to accommodate cations with different sizes and valencies.
DS200512-0834
2005
Sanborn-BarriePehrsson, S.L., Berman, R.G., Rainbird, R., Davis, W., Skulski, Sanborn-Barrie, Van Breeman, Corrigan, TellaInterior collisional orogenesis related to supercontinent assembly: the ca. 1.9- 1.5 Ga tectonic history of the western Churchill province.GAC Annual Meeting Halifax May 15-19, Abstract 1p.Canada, SaskatchewanNuna, tectonics
DS2001-1006
2001
Sanborn-Barrie, M.Sanborn-Barrie, M., Carr, S.D., Theriault, R.Geochronological constraints on metamorphism, magmatism and exhumation of deep crustal rock Kramanituar ComplexContributions to Mineralogy and Petrology, Vol. 141, pp. 592-612.Saskatchewan, Northwest TerritoriesGeochronology, Paleoproterozoic evolution of Archean Churchill
DS200812-0998
2008
Sanborn-Barrie, M.Sanborn-Barrie, M., Chakungal, J., James, D.T., Whalen, J., Rayner, N., Berman, R.G., Craven, J., Coyle, M.New understanding of the geology and diamond prospectivity of Southampton Island, central Nunavut.Northwest Territories Geoscience Office, p. 53-54. abstractCanada, NunavutDeposit - Qilalugaq
DS201212-0680
2012
Sanborn-Barrie, M.Snyder, D.B., Berman, R.G., Kendall, J.M., Sanborn-Barrie, M.Seismic anisotropy and mantle structure of the Rae craton, central Canada, from joint interpretation of SKS splitting and receiver functions.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractCanada, Saskatchewan, Northwest TerritoriesGeophysics - seismics
DS201312-0859
2013
Sanborn-Barrie, M.Snyder, D.B., Berman, R.G., Kendall, J-M., Sanborn-Barrie, M.Seismic anisotropy and mantle structure of the Rae craton, central Canada, from joint interpretation of SKS splitting and receiver functions.Precambrian Research, Vol. 232, pp. 189-208.Canada, Ontario, Hudson Bay, Baffin IslandMantle discontinuities
DS1999-0683
1999
Sanchez, A.Smith, E.I., Sanchez, A., Walker, J.D., Wang, K.Geochemistry of mafic magmas in the Hurricane volcanic field: Implications for small and large scale chemistyJournal of Geology, Vol. 107, No. 4, July pp. 433-48.UtahMagma, basanite, lithosphere xenoliths
DS202203-0354
2022
Sanchez, D.F.Krstulovic, M., Rosa, A.D., Sanchez, D.F., Libon, L., Albers. C., Merkulova, M., Grolimund, D., Irifune, T., Wilke, M.Effect of temperature on the densification of silicate melts to lower Earth's mantle.Physics of the Earth and Planetary Interiora, 13p. PdfMantlemelting

Abstract: Physical properties of silicate melts play a key role for global planetary dynamics, controlling for example volcanic eruption styles, mantle convection and elemental cycling in the deep Earth. They are significantly modified by structural changes at the atomic scale due to external parameters such as pressure and temperature or due to chemistry. Structural rearrangements such as 4- to 6-fold coordination change of Si with increasing depth may profoundly influence melt properties, but have so far mostly been studied at ambient temperature due to experimental difficulties. In order to investigate the structural properties of silicate melts and their densification mechanisms at conditions relevant to the deep Earth's interior, we studied haplo basaltic glasses and melts (albite-diopside composition) at high pressure and temperature conditions in resistively and laser-heated diamond anvil cells using X-ray absorption near edge structure spectroscopy. Samples were doped with 10 wt of Ge, which is accessible with this experimental technique and which commonly serves as a structural analogue for the network forming cation Si. We acquired spectra on the Ge K edge up to 48 GPa and 5000 K and derived the average Ge-O coordination number , and bond distance as functions of pressure. Our results demonstrate a continuous transformation from tetrahedral to octahedral coordination between ca. 5 and 30 GPa at ambient temperature. Above 1600 K the data reveal a reduction of the pressure needed to complete conversion to octahedral coordination by ca. 30 . The results allow us to determine the influence of temperature on the Si coordination number changes in natural melts in the Earth's interior. We propose that the complete transition to octahedral coordination in basaltic melts is reached at about 40 GPa, corresponding to a depth of ca. 1200 km in the uppermost lower mantle. At the core-mantle boundary (2900 km, 130 GPa, 3000 K) the existence of non-buoyant melts has been proposed to explain observed low seismic wave velocity features. Our results highlight that the melt composition can affect the melt density at such extreme conditions and may strongly influence the structural response.
DS200512-0943
2005
Sanchez, J.Schmitz, M., Martins, A., Izarra, C., Jacome, M.I., Sanchez, J., Rocabado, V.The major features of the crustal structure in northeastern Venezuela from deep wide angle seismic observations and gravity modelling.Tectonophysics, Vol. 399, 1-4, April 27, pp. 109-124.South America, VenezuelaGeophysics - seismics, crustal structure, tectonics
DS1990-1299
1990
Sanchez, J.D.Sanchez, J.D.Graphic processing, video digitizing, and presentation of geologicinformationGeobyte, Vol. 5, No. 1, February pp. 64-73GlobalComputer, GIS
DS201012-0652
2010
Sanchez Bellucci, L.Sanchez Bellucci, L., Peel, E., Masquelin, H.Neoproterozoic tectonic synthesis of Uruguay.International Geology Review, Vol. 52, 1, pp. 51-78.South America, UruguayTectonics
DS201012-0653
2010
Sanchez Bellucci, L.Sanchez Bellucci, L., Peel, E., Oyhantcabal, P.Precambrian geotectonic units of the Rio de la Plat a craton.International Geology Review, Vol. 52, 1, pp. 32-50.South AmericaTectonics
DS2003-1049
2003
Sanchez Bettucci, L.Pazos, P.J., Sanchez Bettucci, L., Tofalo, O.R.The record of the Varanger glaciation at the Rio de la Plat a Craton, Vendian CambrianGondwana Research, Vol. 6, No. 1, pp. 65-78.Uruguay, South AmericaGeomorphology
DS201012-0654
2010
Sanchez Bettucci, L.Sanchez Bettucci, L., Peel, E., Masquelin, H.Neoproterozoic tectonic synthesis of Uruguay.International Geology Review, Vol. 52, 1, pp. 51-78.South America, UruguayTectonics
DS201012-0655
2010
Sanchez Bettucci, L.Sanchez Bettucci, L., Peel, E., Oyhantcabal, P.Precambrian geotectonic units of the Rio de la Plat a craton.International Geology Review, Vol. 52, 1, pp. 32-50.South America, BrazilTectonics
DS202004-0507
2020
Sanchez Bettucci, L.Demarco, P.N., Masquelin, H., Prezzi, C., Muzio, R., Loureiro, J., Peel, E., Campal, N., Sanchez Bettucci, L. Aeromagnetic patterns in southern Uruguay: Precambrian- Mesozoic dyke swarms and Mesozoic rifting structural and tectonic evolution.Tectonophysics, in press available 40p. PdfSouth America, Uruguaygeophysics

Abstract: New high-resolution airborne magnetic data of Uruguay allowed constructing new maps concerning the spatial distribution of dyke swarms, main faults and other magnetic bodies, which compose the Uruguayan Shield. We combined geophysical analyses (vertical derivatives, upward continuation, Euler deconvolution), structural analyses of the magnetic maps and previous geological data in order to discriminate the main structural features of the Uruguayan Shield and contribute to a better understanding of its tectonic evolution. The magnetic maps revealed several outstanding features in the Uruguayan Shield. The Paleoproterozoic dyke swarm is larger, denser, more widespread and complex than originally thought, suggesting a possible plume origin. In addition, a new Mesozoic dyke swarm, as complex as the previous one, was identified crosscutting the Paleoproterozoic dyke swarm and the Neoproterozoic orogenic structures. Moreover, this swarm is connected to volcanic calderas in the Merín basin, and shows displacements along Neoproterozoic shear zones, in the magnetic maps, revealing its brittle reactivation during Mesozoic times. The new observations clarify how Proterozoic basement structures controlled the development of the Mesozoic rift. Paleoproterozoic dyke swarms were reactivated as normal faults and Neoproterozoic structures hindered the rift growth, deflecting the deformation in transcurrent movements. Meanwhile, the Mesozoic dyke swarm was developed in a perpendicular direction to the Neoproterozoic structures. Moreover, these findings contradict the current rift model for Uruguay and rise a new model in which the Mesozoic rift developed as two rift basins connected by a central transfer zone, generated by the reactivation of Dom Feliciano Belt structures, between the Sierra Ballena and Sarandí del Yí Shear Zones.
DS201112-0065
2011
Sanchez Bettuci, L.Basei, M.A.S., Peel, E., Sanchez Bettuci, L., Preciozzi, F., Nutman, A.P.The basement of the Punta del Este Terrane (Uruguay): an African Mesoproterozoic fragment at the eastern border of the South American Rio de la Plat a craton.International Journal of Earth Sciences, Vol. 100, 2, pp. 289-304.South America, UruguayCraton, Rodinia
DS202104-0565
2021
Sanchez-Gamboa, A.K.Arnaiz-Rodriguez, M., Zhao, Y., Sanchez-Gamboa, A.K., Audemard, F.Crustal and upper-mantle structure of the eastern Caribbean and northern Venezuela from passive Rayleigh wave tomography.Tectonophysics, Vol. 804, 228711 18p. pdf South America, Venezuelageophysics - seismic

Abstract: We explore the shear-wave lithospheric velocity structure of the Eastern Caribbean and Northern Venezuela using ambient noise tomography with stations deployed around the study area. We construct cross-correlation functions from continuous seismic records, and measure phase velocities of fundamental-mode Rayleigh waves. These velocities are further projected onto 0.6°x0.6° phase velocity grids for each period between 5 s and 50 s. The pseudo-dispersion curve at each grid point is inverted for 1D shear velocity profiles by using a Markov Chain Monte Carlo scheme. The interpolated 3D velocity model shows that the mean shear velocity of the Eastern Caribbean lithospheric mantle is lower than the global average, which is in agreement with values reported in other large igneous provinces. We interpret that low velocities in the lithospheric keel are associated with an anomalous composition and/or an elevated thermal state; this gives the Caribbean plate a high buoyancy that determines the subduction polarities in the region. The results also indicate that: (a) the mantle beneath Northern Venezuela retains compositional anomalies related to extension processes of different ages; (b) the overriding of the Caribbean plate by the Great Antilles arc seems to be much slower than previously suggested; and (c) the localized volcanism in the center of the Lesser Antilles arc is related to asthenospheric flow through the tear induced on the subducted slab by major strike-slip faults.
DS201902-0270
2018
Sanchez-Navas, A.Farre-de-Pablo, J., Proenza, J.A., Gonzales-Jimenez, J.M., Garcia-Casco, A., Colas, V., Roque-Rossell, J., Camprubi, A., Sanchez-Navas, A.A shallow origin for diamonds in ophiolitic chromitites.Geology, Vol. 46, pp. 75-78.Mexico, Pueblaophiolite

Abstract: Recent findings of diamonds in ophiolitic peridotites and chromitites challenge our traditional notion of Earth mantle dynamics. Models attempting to explain these findings involve incorporation of diamonds into chromite near the mantle transition zone. However, the occurrence of metastable diamonds in this context has not been considered. Here, we report for the first time in situ microdiamonds in chromite from ophiolitic chromitite pods hosted in the Tehuitzingo serpentinite (southern Mexico). Here, diamonds occur as fracture-filling inclusions along with quartz, clinochlore, serpentine, and amorphous carbon, thus indicating a secondary origin during the shallow hydration of chromitite. Chromite chemical variations across the diamond-bearing healed fractures indicate formation during the retrograde evolution of chromitite at temperatures between 670 °C and 515 °C. During this stage, diamond precipitated metastably at low pressure from reduced C-O-H fluids that infiltrated from the host peridotite at the onset of serpentinization processes. Diamond was preserved as a result of fracture healing at the same temperature interval in which the chromite alteration began. These mechanisms of diamond formation challenge the idea that the occurrence of diamond in ophiolitic rocks constitutes an unequivocal indicator of ultrahigh-pressure conditions.
DS201909-2038
2019
Sanchez-Navas, A.Farre-de-Pblo, J., Proenza, J.A., Gonzalez-Jiminez, J.M., Garcia-Casco, A., Colas, V., Roque-Rosell, J., Camprubi, A., Sanchez-Navas, A.A shallow origin for diamonds in ophiolitic chromitites. Geology, Vol. 47, pp. e477-478.North America, Mexicomicrodiamonds

Abstract: Recent findings of diamonds in ophiolitic peridotites and chromitites challenge our traditional notion of Earth mantle dynamics. Models attempting to explain these findings involve incorporation of diamonds into chromite near the mantle transition zone. However, the occurrence of metastable diamonds in this context has not been considered. Here, we report for the first time in situ microdiamonds in chromite from ophiolitic chromitite pods hosted in the Tehuitzingo serpentinite (southern Mexico). Here, diamonds occur as fracture-filling inclusions along with quartz, clinochlore, serpentine, and amorphous carbon, thus indicating a secondary origin during the shallow hydration of chromitite. Chromite chemical variations across the diamond-bearing healed fractures indicate formation during the retrograde evolution of chromitite at temperatures between 670 °C and 515 °C. During this stage, diamond precipitated metastably at low pressure from reduced C-O-H fluids that infiltrated from the host peridotite at the onset of serpentinization processes. Diamond was preserved as a result of fracture healing at the same temperature interval in which the chromite alteration began. These mechanisms of diamond formation challenge the idea that the occurrence of diamond in ophiolitic rocks constitutes an unequivocal indicator of ultrahigh-pressure conditions.
DS202010-1869
2020
Sanchez-Navas, A.Pujol-Sola, N., Garcia-Casco, A., Proenza, J.A., Gonzalez-Jiminez, J.M., del Camp, A., Colas, V., Canals, A., Sanchez-Navas, A., Roque-Rosell, J.Diamond forms during low pressure serpentinisation of oceanic lithosphere.Geochemical Perspectives Letters, 7p. PdfCentral America, Cubadiamond genesis

Abstract: Diamond is commonly regarded as an indicator of ultra-high pressure conditions in Earth System Science. This canonical view is challenged by recent data and interpretations that suggest metastable growth of diamond in low pressure environments. One such environment is serpentinisation of oceanic lithosphere, which produces highly reduced CH4-bearing fluids after olivine alteration by reaction with infiltrating fluids. Here we report the first ever observed in situ diamond within olivine-hosted, CH4-rich fluid inclusions from low pressure oceanic gabbro and chromitite samples from the Moa-Baracoa ophiolitic massif, eastern Cuba. Diamond is encapsulated in voids below the polished mineral surface forming a typical serpentinisation array, with methane, serpentine and magnetite, providing definitive evidence for its metastable growth upon low temperature and low pressure alteration of oceanic lithosphere and super-reduction of infiltrated fluids. Thermodynamic modelling of the observed solid and fluid assemblage at a reference P-T point appropriate for serpentinisation (350 °C and 100 MPa) is consistent with extreme reduction of the fluid to logfO2 (MPa) = ?45.3 (?logfO2[Iron-Magnetite] = ?6.5). These findings imply that the formation of metastable diamond at low pressure in serpentinised olivine is a widespread process in modern and ancient oceanic lithosphere, questioning a generalised ultra-high pressure origin for ophiolitic diamond.
DS200612-0097
2006
Sanchez-Valle, C.Bass, J.D., Sanchez-Valle, C., Lakshtanov, D.L., Brenizer, J., Wang, J., Matas, J.Elastic properties of high pressure phases and implications for the temperature and mineralogy of Earth's lower mantle.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.MantleGeothermometry
DS200712-0933
2007
Sanchez-Valle, C.Sanchez-Valle, C., Litasov, K., Ohtani, E., Bass, E.Sound velocities and single crystal properties of DHMS phase E to high pressure.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p.193.MantleTransition zone
DS200712-0934
2007
Sanchez-Valle, C.Sanchez-Valle, C., Litasov, K., Ohtani, E., Bass, E.Sound velocities and single crystal properties of DHMS phase E to high pressure.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p.193.MantleTransition zone
DS201702-0244
2017
Sanchez-Valle, C.Tsay, A., Zajacz, Z., Ulmer, P., Sanchez-Valle, C.Mobility of major and trace elements in the eclogite-fluid system and element fluxes upon slab dehydration.Geochimica et Cosmochimica Acta, Vol. 198, pp. 70-91.MantleSubduction

Abstract: The equilibrium between aqueous fluids and allanite-bearing eclogite has been investigated to constrain the effect of temperature (T) and fluid composition on the stability of allanite and on the mobility of major and trace elements during the dehydration of eclogites. The experiments were performed at 590-800 °C and 2.4-2.6 GPa, and fluids were sampled as synthetic fluid inclusions in quartz using an improved entrapment technique. The concentrations and bulk partition coefficients were determined for a range of major (Mg, Ca, Na, Fe, Al, Ti) and 16 trace elements as a function of T and fluid composition. The results reveal a significant effect of T on element partitioning between the fluids and the solid mineral assemblage. The partition coefficients increase by more than an order of magnitude for most of the major and trace elements, and several orders of magnitude for light rare-earth elements (LREE) from 590 to 800 °C. The addition of various ligand species into the fluid at 700 °C results in distinctive trends on element partitioning. The concentrations and corresponding partition coefficients of most of the elements are enhanced upon addition of NaF to the fluid. In contrast, NaCl displays a nearly opposite effect by suppressing the solubilities of major elements and consequently affecting the mobility of trace elements that form stable complexes with alkali-(alumino)-silicate clusters in the fluid, e.g. high field strength elements (HFSE). The results further suggest that fluids in equilibrium with orthopyroxene and/or diopsidic clinopyroxene are peralkaline (ASI ?0.1-0.7), whereas fluids in equilibrium with omphacitic pyroxene are more peraluminous (ASI ?1.15). Therefore, natural aqueous fluids in equilibrium with eclogite at about 90 km depth will be slightly peraluminous in composition. Another important finding of this study is the relatively high capacity of aqueous fluids to mobilize LREE, which may be even higher than that of hydrous melts.
DS201907-1555
2019
Sanchez-Valle, C.Kupenko, G.A., Vasilukov, D.M., McCammon, C., Charleton, S., Cerantola, V., Kantor, I., Chumakov, A.I.., Ruffer, R., Dubrovinsky, L, Sanchez-Valle, C.Magnetism in cold subducting slabs at mantle transition zone depths.Nature, Vol. 570, 7759, p. 102.Mantlesubduction

Abstract: The Earth’s crust-mantle boundary, the Mohorovi?i? discontinuity, has been traditionally considered to be the interface between the magnetic crust and the non-magnetic mantle1. However, this assumption has been questioned by geophysical observations2,3 and by the identification of magnetic remanence in mantle xenoliths4, which suggest mantle magnetic sources. Owing to their high critical temperatures, iron oxides are the only potential sources of magnetic anomalies at mantle depths5. Haematite (?-Fe2O3) is the dominant iron oxide in subducted lithologies at depths of 300 to 600 kilometres, delineated by the thermal decomposition of magnetite and the crystallization of a high-pressure magnetite phase deeper than about 600 kilometres6. The lack of data on the magnetic properties of haematite at relevant pressure-temperature conditions, however, hinders the identification of magnetic boundaries within the mantle and their contribution to observed magnetic anomalies. Here we apply synchrotron Mössbauer source spectroscopy in laser-heated diamond anvil cells to investigate the magnetic transitions and critical temperatures in Fe2O3 polymorphs7 at pressures and temperatures of up to 90 gigapascals and 1,300 kelvin, respectively. Our results show that haematite remains magnetic at the depth of the transition zone in the Earth’s mantle in cold or very cold subduction geotherms, forming a frame of deep magnetized rocks in the West Pacific region. The deep magnetic sources spatially correlate with preferred paths of the Earth’s virtual geomagnetic poles during reversals8 that might not reflect the geometry of the transitional field. Rather, the paths might be an artefact caused by magnetized haematite-bearing rocks in cold subducting slabs at mid-transition zone depths. Such deep sources should be taken into account when carrying out inversions of the Earth’s geomagnetic data9, and especially in studies of planetary bodies that no longer have a dynamo10, such as Mars.
DS202002-0215
2020
Sanchez-Valle, C.Ritter, X., Sanchez-Valle, C., Sator, N., Desmaele, E., Guignot, N., King, A., Kupenko, I., Berndt, J., Guillot, B.Density of hydrous carbonate melts under pressure, compressability of volatiles and implications for carbonate melt mobility in the upper mantle.Earth and Planetary Science Letters, Vol. 533, 11p. PdfMantlecarbon

Abstract: Knowledge of the effect of water on the density of carbonate melts is fundamental to constrain their mobility in the Earth's interior and the exchanges of carbon between deep and surficial reservoirs. Here we determine the density of hydrous MgCO3 and CaMg(CO3)2 melts (10 wt% H2O) from 1.09 to 2.98 GPa and 1111 to 1763 K by the X-ray absorption method in a Paris-Edinburgh press and report the first equations of state for hydrous carbonate melts at high pressure. Densities range from 2.26(3) to 2.50(3) g/cm3 and from 2.34(3) to 2.48(3) g/cm3 for hydrous MgCO3 and CaMg(CO3)2 melts, respectively. Combining the results with density data for the dry counterparts from classical Molecular Dynamic (MD) simulations, we derive the partial molar volume (, ) and compressibility of H2O and CO2 components at crustal and upper mantle conditions. Our results show that in alkaline carbonate melts is larger and less compressible than at the investigated conditions. Neither the compressibility nor depend on carbonate melt composition within uncertainties, but they are larger than those in silicate melts at crustal conditions. in alkaline earth carbonate melts decreases from 25(1) to 16.5(5) cm3/mol between 0.5 and 4 GPa at 1500 K. Contrastingly, comparison of our results with literature data suggests strong compositional effects on , that is also less compressible than in transitional melts (e.g., kimberlites) and carbonated basalts. We further quantify the effect of hydration on the mobility of carbonate melts in the upper mantle and demonstrate that 10 wt% H2O increases the mobility of MgCO3 melts from 37 to 67 g.cm?3.Pa?1s?1 at 120 km depth. These results suggest efficient carbonate melt extraction during partial melting and fast migration of incipient melts in the shallow upper mantle.
DS202102-0181
2020
Sanchez-Vizcaino, V.L.Dilissen, N., Hidas, K., Garrido, C.J., Kahl, W-A., Sanchez-Vizcaino, V.L.Graphical abstract: Morphological transition during prograde olivine growth formed by high-pressure dehydration of antigorite-serpentinite to chlorite-harzburgite in a subduction setting.Lithos, doi. 10.1016/j. lithos.2020.105949 1p. PdfMantlesubduction

Abstract: Crystal morphologies are essential for deciphering the reaction history of igneous and metamorphic rocks because they often record the interplay between nucleation and growth rates controlled by the departure from equilibrium. Here, we report an exceptional record of the morphological transition of olivine formed during subduction metamorphism and high-pressure dehydration of antigorite-serpentinite to prograde chlorite-harzburgite in the Almirez ultramafic massif (Nevado-Filábride Complex, Betic Cordillera, SE Spain). In this massif, rare varied-textured chlorite-harzburgite (olivine+enstantite+chlorite+oxides) —formed after high-P dehydration of antigorite-serpentinite— exhibits large olivine porphyroblasts made up of rounded cores mantled by coronas of tabular olivine grains, similar to single tabular olivines occurring in the matrix. The correlative X-ray ?-CT and EBSD study of two varied-textured chlorite-harzburgite samples show that tabular olivine in coronas is tabular on (100)Ol with c > b >> a, and grew in nearly the same crystallographic orientation as the rounded olivine cores of the porphyroblast. Quantitative textural analysis and mass balance indicate that varied-textured chlorite-harzburgite is the result of a two-stage nucleation and growth of olivine during the progress of the high-P dehydration of antigorite-serpentinite to chlorite-harzburgite reaction. The first stage occurred under a low affinity (?Gr) and affinity rate (?Gr/dt) of the antigorite dehydration reaction that resulted in a low time-integrated nucleation rate and isotropic growth of olivine, forming rounded olivine porphyroblasts. With further progress of the dehydration reaction, a second stage of relatively higher affinity and affinity rate resulted in a higher time-integrated nucleation rate of olivine coeval with a shift from isotropic to anisotropic olivine growth, leading to tabular olivines. The two-stage evolution resulted in olivine porphyroblasts made up of rounded cores mantled by coronas of tabular olivine grains characteristic of varied-texture chlorite-harzburgite. Although a switch to anisotropic tabular olivine in the second stage is consistent with the relative increase in the affinity and affinity rate, these changes cannot solely account for the growth of Almirez olivine tabular on (100). Tabular olivines in komatiites and other igneous rocks are tabular on (010)Ol with either a > c >> b, or a ? c > > b, in agreement with experimentally determined growth rates of olivine phenocrysts under moderate to high undercooling and cooling rates. On the other hand, olivine tabular on (100) is expected in the presence of highly polymerized fluids where inhibited growth of the olivine (100) and (010) interfaces occurs, respectively, due to dissociative and molecular adsorption of water monolayers. Rounded and tabular olivines in Almirez varied-textured chlorite-harzburgite show differing trace element compositions that we interpret as due to the infiltration of external fluids during antigorite dehydration. Isothermal infiltration of highly polymerized fluids would explain the shift in the affinity and affinity rate of the antigorite dehydration reaction, as well as the olivine morphology tabular on (100) due to the inhibited growth on the (100) and, to a lesser extent, (010). Our study shows that surface-active molecules may play an essential role in shaping the morphology of growing crystals during fluid-present metamorphic crystallization.
DS201012-0311
2010
Sanchira, T.Irifune, T., Isobe, F., Shinmei, T., Sanchira, T., Ohfuji, H., Kurio, A., Sumiya, H.Synthesis of ultrahard nano-polycrystalline diamond at high pressure and temperature using a large volume multianvil apparatus.International Mineralogical Association meeting August Budapest, abstract p. 182.TechnologyDiamond synthesis
DS200712-1036
2007
Sand, K.K.Steenfelt, A., Neilsen, T.D.F., Sand, K.K., Secher, K.,Tappe, S.Kimberlites, ultramafic lamprophyres and carbonatites in west Greenland - an update on occurrences, ages and diamonds.Geological Association of Canada, Gac-Mac Yellowknife 2007, May 23-25, Volume 32, 1 pg. abstract p.79.Europe, GreenlandGeochronology
DS200812-0796
2008
Sand, K.K.Nielsen, T.F.D., Jensen, S.M., Secher, K., Sand, K.K.Regional and temporal variations in the magmatism of the diamond province of southern west Greenland.9IKC.com, 3p. extended abstractEurope, GreenlandDykes - Sisimiut, Sarfartoq
DS200812-0797
2008
Sand, K.K.Nielsen, T.F.D., Sand, K.K.The Majuagaa kimberlite dike, Maniitsoq region, West Greenland: constraints for an Mg rich silico carbonatite melt composition from groundmass mineralogy and bulk compositions.Canadian Mineralogist, Vol. 46, 4, August pp.Europe, GreenlandCarbonatite, kimberlite
DS200812-0999
2007
Sand, K.K.Sand, K.K., Nielsen, T.F.D., Secher, K., Steenfelt, A.Kimberlite and carbonatite exploration in southern West Greenland: summary of previous activities and recent work by the kimberlite research group at the Geological Survey of Denmark and Greenland.Vladykin Volume 2007, pp. 127-140.Europe, Denmark, GreenlandExploration activity
DS200912-0535
2009
Sand, K.K.Nielsen, T.F.D., Jensen, S.M., Secher, K., Sand, K.K.Distribution of kimberlite and aillikite in the diamond province of southern West Greenland: a regional perspective based on groundmass mineral chemistry and bulk compositions.Lithos, In press - available 45p.Europe, GreenlandGeochemistry
DS200912-0661
2009
Sand, K.K.Sand, K.K., Waight, T.E., Pearson, D.G., Nielsen, T.F.D., Makovicky, E., Hutchison, M.T.The lithospheric mantle below southern West Greenland: a geothermobarometric approach to diamond potential and mantle stratigraphy.Lithos, In press availableEurope, GreenlandDiamond prospectivity, geothermometry
DS200912-0733
2009
Sand, K.K.Steenfelt, A., Jensen, S.M., Nielsen, T.F.D., Sand, K.K., Secher, K.Diamonds and lithospheric mantle properties in the neo-proterzoic igneous province of southern West Greenland. ( Garnet Lake area).Geological Survey of Denmark and Greenland, Bulletin 17, pp. 65-68.Europe, GreenlandDiamond exploration - brief overview
DS201012-0755
2009
Sand, K.K.Steenfelt, A., Jensen, S.M., Nielsen, T.F.D., Sand, K.K.Provinces of ultramafic lamprophyre dykes, kimberlite dykes and carbonatite in West Greenland characterised by minerals and chemical components in surface media.Lithos, Vol. 112 S pp. 116-123.Europe, GreenlandGeochemistry
DS1900-0588
1907
Sandberg, C.G.S.Sandberg, C.G.S.Discussion on the Paper by Voit Entitled Kimberlite Dykes and Pipes. #5Geological Society of South Africa Proceedings, Vol. 10, PP. XLIV-XLVI. ALSO: SOUTH AFRICA, Vol. 75, SEPT. 1Africa, South AfricaPetrology, Kimberlite Mines And Deposits
DS1993-1373
1993
Sandberg, T.Sandberg, T.Ranch Lake drilling report, Ice ClaimsCanamera Geol. Ltd., Lytton Minerals, 267p. not on fileNorthwest TerritoriesExploration - assessment, Deposit - Ranch Lake
DS2000-0210
2000
SandemanDavis, W.J., Hanmer, Aspler, Sandeman, Tella, ZaleskiRegional differences in the Neoarchean crustal evolution of the Western Churchill Province: sense??Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000 Conference, 4p. abstract.Manitoba, Western CanadaGeochronology - Hearne domain
DS2000-0384
2000
SandemanHanmer, S., Aspler, L., Sandeman, Davis, Peterson, RelfHenik - Kaminak - Tavani supracrustal belt. late Archean oceanic crust and island arc remnants....Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000 Conference, 4p. abstract.Northwest Territories, ChurchillProterozoic reworking, Structure
DS2001-0912
2001
SandemanPeterson, T.D., Van Breemen, Sandeman, CousensPostorogenic granitoids and ultrapotassic rocks in the Hinterland of the Trans Hudson Orogen.Geological Association of Canada (GAC) Annual Meeting Abstracts, Vol. 26, p. 117.abstract.Saskatchewan, GreenlandMinettes
DS2003-1055
2003
SandemanPehrsson, S.J., Peterson, T., Davis, W.J., Sandeman, Skulski, Van BreenenAncient Archean crust in the Western Churchill Province: a review of direct and indirect31st Yellowknife Geoscience Forum, p. 75. (abst.)Saskatchewan, Manitoba, NunavutTectonics - lithosphere
DS2003-1056
2003
SandemanPehrsson, S.J., Peterson, T., Davis, W.J., Sandeman, Skulski, Van BreenenThe Western Churchill metallogeny project: from Melville to Uranium City, a new look31st Yellowknife Geoscience Forum, p. 77. (abst.)Saskatchewan, Manitoba, Nunavut, Northwest TerritoriesBedrock compilation
DS200412-1515
2003
SandemanPehrsson, S.J., Peterson, T., Davis, W.J., Sandeman, Skulski, Van Breenen, Hartlaub, Wodicks, Hanmer, CousensAncient Archean crust in the Western Churchill Province: a review of direct and indirect evidence.31st Yellowknife Geoscience Forum, p. 75. (abst.)Canada, Saskatchewan, Manitoba, NunavutTectonics - lithosphere
DS200412-1516
2003
SandemanPehrsson, S.J., Peterson, T., Davis, W.J., Sandeman, Skulski, Van Breenen, Hartlaub, Wodicks, Hanmer, CousensThe Western Churchill metallogeny project: from Melville to Uranium City, a new look at the largest under explored Craton in the31st Yellowknife Geoscience Forum, p. 77. (abst.)Canada, Saskatchewan, Manitoba, Northwest Territories, NunavutBedrock compilation
DS200712-0769
2006
SandemanNadeau, L., Ryan, J.J., Hinchey, A.M., James, Sandeman, Tremblay, Schetselaar, Berman, DavisOutlook on the geology of the Boothia MaIn land area, Kitikmeot region, Nunavut.34th Yellowknife Geoscience Forum, p. 39-40. abstractCanada, NunavutGeology - brief overview
DS2000-0853
2000
Sandeman, H.Sandeman, H., Cousens, B., Peterson, Hemmingway, davisPetrochemistry and neodymium isotopic evolution of Proterozoic mafic rocks of Western Churchill Province... mantleGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000, 4p. abstract.Northwest TerritoriesPetrology, dykes, Kaminak, MacQuid, Tulemalu
DS2000-0854
2000
Sandeman, H.Sandeman, H., Davis, W., Hanmer et al.Archean volcanic sequences of the Western Churchill Province, Nunavut: three petrochemically distinct ...Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000, 4p. abstract.Northwest TerritoriesVolcanics - not specific to diamonds
DS2002-1254
2002
Sandeman, H.Peterson, T.D., Van Breemen, O., Sandeman, H., Cousens, B.Proterozoic (1.85-1.75 Ga) igneous suites of the Western Churchill Province: granitoidPrecambrian Research, Vol. 119, No. 1-4, pp. 73-100.Alberta, Northwest TerritoriesMagmatism - tectonics, Minettes, Trans Hudson
DS200412-1272
2004
Sandeman, H.McHattie, T.G., Heaman, L.M., Creaser, R.A., Skulski, T., Sandeman, H.Dynamic melting in an Archean mantle plume: chemical signature of Prince Albert Group komatiite and basalt, Nunavut Canada.Geochimica et Cosmochimica Acta, 13th Goldschmidt Conference held Copenhagen Denmark, Vol. 68, 11 Supp. July, ABSTRACT p.A595.Canada, NunavutMantle plume
DS200612-1214
2005
Sandeman, H.Sandeman, H.Kimberlites and other intracratonic, mantle derived suites in the NWT and NT: activities of the NWT Geoscience office.32ndYellowknife Geoscience Forum, POSTERCanada, Northwest Territories, NunavutGeology, tectonics
DS1997-0994
1997
Sandeman, H.A.Sandeman, H.A., Clark, A.H., Pauca, G.A.Lithostratigraphy, petrology and 40 Ar-39 Ar geochronology of the CruceroSupergroup, Puno ..Journal of South American Earth Sciences, Vol. 10, No. 3-4, pp. 223-246PeruGeochronology, Argon
DS2000-0385
2000
Sandeman, H.A.Hanmer, S., Sandeman, H.A., Davis, W.J.NeoArchean tectonic setting of the Hearne domain, western Churchill Province: is there a modern analogue.28th. Yellowknife Geoscience Forum, p. 32-3.abstractNorthwest TerritoriesTectonics, Hearne Domain
DS2001-1007
2001
Sandeman, H.A.Sandeman, H.A.The Western Churchill Province: a summary of current state of knowledge ofa poorly known Archean Craton.Geological Association of Canada (GAC) Annual Meeting Abstracts, Vol. 26, p. 131.abstract.Northwest Territories, Manitoba, Saskatchewan, AlbertaSnowbird Tectonic Zone
DS2001-1008
2001
Sandeman, H.A.Sandeman, H.A.40Ar 39 Ar geochronological investigations in the central Hearne domain, western Chruchill province...Can. Geological Survey Radiogenic, No. 14, 2001-F4. 41p.Northwest Territories, NunavutGeochronology, Argon
DS2003-1211
2003
Sandeman, H.A.Sandeman, H.A., Cousens, B.L., Hemmingway, C.J.Continental tholeitic mafic rocks of the Paleoproterozoic Hurwitz Group, centralCanadian Journal of Earth Sciences, Vol. 40, 9,Sept. 1219-37.NunavutMagmatism
DS200412-0420
2004
Sandeman, H.A.Davis, W.J., Hanmer, S., Sandeman, H.A.Temporal evolution of the Neoarchean central Hearne supracrustal belt: rapid generation of juvenile crust in a supra subduction zPrecambrian Research, Vol. 134, no. 1-2, Sept. 20, pp. 85-112.Canada, Nunavut, Northwest TerritoriesSubduction
DS200412-0782
2004
Sandeman, H.A.Hanmer, S., Sandeman, H.A., Davis, W.J., Aspler, L.B., Rainbird, R.H., Ryan, J.J., Relf, C., Peterson, T.D.Geology and Neoarchean tectonic setting of the Central Hearne supracrustal belt, Western Churchill Province, Nunavut, Canada.Precambrian Research, Vol. 134, 1-2, pp. 63-83.Canada, NunavutTectonics - not specific to diamonds
DS200412-1726
2003
Sandeman, H.A.Sandeman, H.A., Cousens, B.L., Hemmingway, C.J.Continental tholeitic mafic rocks of the Paleoproterozoic Hurwitz Group, central Hearne sub-domain, Nunavut: insight into the evCanadian Journal of Earth Sciences, Vol. 40, 9,Sept. 1219-37.Canada, NunavutMagmatism
DS200412-1727
2004
Sandeman, H.A.Sandeman, H.A., Hanmer, S., Davis, W.J., Ryan, J.J., Peterson, T.D.Neoarchean volcanic rocks, central Hearne supracrustal belt, Western Churchill Province: geochemical and isotopic evidence suppoPrecambrian Research, Vol. 134, no. 1-2, Sept. 20, pp. 113-141.Canada, Nunavut, Northwest TerritoriesSubduction
DS200612-1419
2005
Sandeman, H.A.Tella, S., Paul, D., Davis, W.J., Berman, R.G., Sandeman, H.A., Peterson, T.D., Pehrsson, KerswillBedrock geology compilation and regional synthesis, parts of Hearne domain, Nunavut.Geological Survey of Canada Open file, No. 4729, 2 sheetsCanada, NunavutMap - geology - mentions diamonds
DS200712-0935
2007
Sandeman, H.A.Sandeman, H.A., Barnett, R.L., Laboucan, B., Flemming, R., Tubrett, M.Unique garnet compositions from the Mud Lake kimberlite SW Slave Province, NWT: an occurrence of rare high Cr-Ca green garnets.Geological Association of Canada, Gac-Mac Yellowknife 2007, May 23-25, 1 pg. abstract p.70-71.Canada, Northwest TerritoriesGarnet analyses
DS200812-0650
2007
Sandeman, H.A.Leslie, C.D., Sandeman, H.A., Mortensen, J.K.Diatremes and related volcanic rocks of the lower Palezoic Misty Creek Embayment, Mackenzie Mountains, NT.35th. Yellowknife Geoscience Forum, Abstracts only p. 34-35.Canada, Northwest TerritoriesMountain Diatreme - geology
DS200812-0651
2008
Sandeman, H.A.Leslie, C.D., Sandeman, H.A., Mortensen, J.K.Lower Paleozoic rift related alkaline volcanic rocks, Mackenzie Mountains, NWT.Northwest Territories Geoscience Office, p. 40. abstractCanada, Northwest TerritoriesBrief overview - Mountain diatreme
DS200812-1000
2008
Sandeman, H.A.Sandeman, H.A., Barnett, R.L., Laboucan, A.B.An overview of the Mud Lake kimberlite, SW Slave Craton, Northwest Territories, and implications of the presence of high Cr2O3, CaO rich green garnets.9IKC.com, 3p. extended abstractCanada, Northwest TerritoriesDeposit - Mud Lake petrography
DS200812-1001
2008
Sandeman, H.A.Sandeman, H.A., Ryan, J.J.Petrology of kimberlite debris from the GSC showing. Amaruk kimberlite field, Kiyikmeot region, Nunavut Canada. 57A03 NTSGeological Survey of Canada, Open File 5876, 23p.Canada, NunavutDeposit - Amaruk
DS200812-1002
2007
Sandeman, H.A.Sandeman, H.A., Udell, A.Whither the kimberlite indicator and diamond database (KIDD) and kimberlite indicator mineral chemistry Database ( KIMC): integration into GOMAP for on-line35th. Yellowknife Geoscience Forum, Abstracts only p. 55.Canada, Northwest TerritoriesDatabase - KIDD and KIMC
DS201012-0049
2010
Sandeman, H.A.Berman, R.G., Sandeman, H.A., Camacho, A.Diachronous Paleoproterozoic deformation and metamorphism in the Committee Bay belt, Rae Province, Nunavut: insights from 40Ar 39 Ar cooling agesJournal of Metamorphic Geology., Vol. 28, 5, pp. 439-457.Canada, NunavutGeothermometry - not specific to diamonds
DS201911-2551
2019
Sandemann, H.Ootes, L., Sandemann, H., Cousens, B.L.,Luo, Y., Pearson, D.G., Jackson, V.Pyroxenite magma conduits ( ca 1.86 Ga) in Wopmay orogen and Slave craton: petrogenetic constrainst from whole rock and mineral chemistry.Lithos, in press available, 54p.Canada, Northwest Territorieslamprophyres
DS201112-0201
2011
Sander, A.Conceicao, R.V., Lenz, C., Provenzano, C.A.S., Sander, A., Silveira, F.V.U Pb perovskite ages of kimberlites from the Rosario do Sul cluster Southern Brazil.Goldschmidt Conference 2011, abstract p.691.South America, Brazil, Rio Grande do SulGeochronology
DS201112-0904
2010
Sander, A.Sander, A., Provenzano, C., Valdir Silveira, F., Castro, J.H., Bottari, L.Um novo corpo kimberlitico no escudo sul rio Grandense: petrografia preliminar.5th Brasilian Symposium on Diamond Geology, Nov. 6-12, abstract p. 75.South America, BrazilGeobank
DS201312-0127
2014
Sander, L.Caron, R.M., Samson, C., Straznicky, P., Ferguson, S., Sander, L.Aeromagnetic surveying using a simulated unmanned aircraft system. ( not specific to diamonds)Geophysical Prospecting, Vol. 62, 2, pp. 352-363.Canada, OntarioGeophysics - aeromagnetics
DS1910-0593
1919
Sander, L.A.Sander, L.A.Some Facts about the South African Diamond MinesJewellers Circular Keystone, Vol. 78, No. 12, APRIL 23RD. P. 53.South AfricaCurrent Activities
DS1989-1334
1989
Sander, S.Sander, S., Rosendahl, B.R.The geometry of rifting in Lake Tanganyika, East AfricaJournal of African Earth Sciences, Vol. 8, No. 2/3/4, pp. 323-354East AfricaTectonics, Rifting -Lake Tanganyika
DS1989-1427
1989
Sanders, D.B.Soifer, B.T., Beichman, C.A., Sanders, D.B.An infrared view of the universe #1American Scientist, Vol. 77, No. 1, January-February pp. 46-53. Database #GlobalGeophysics, Remote sensing -IRAS
DS201212-0622
2010
Sanders, E.and C.Sanders, E.and C.Rio Tinto's Argyle pink diamonds tender update.The Australian Gemmologist, Vol. 24, 4, Oct-Dec pp.AustraliaDeposit - Argyle
DS1970-0828
1973
Sanders, J.R.Slettene, R.L., Wilcox, L.E., Blouse, R.S., Sanders, J.R.A Bouger Gravity Anomaly Map of AfricaDefense Mapping Agency Aerospace Centre Tech. Paper., No. 73-3Africa, South Africa, BotswanaGeophysics
DS1983-0555
1983
Sanders, J.V.Sanders, J.V.The Quantitative Evaluation of the Colour of DiamondsAustralian Gemologist., Vol. 15, No. 3, PP. 91-92.AustraliaDiamond Morphology
DS1983-0418
1983
Sanders, P.R.Luza, K.V., Ham, E.A., Sanders, P.R.Indexes to Surface and Subsurface Geologic Mapping in Oklahoma 1977-1979.Oklahoma Geological Survey Map, No. GM 26, S HEETS.OklahomaMid Continent
DS1996-1446
1996
Sanderson, D.J.Tuckwell, G.W., Bulletin, G.W., Sanderson, D.J.Models of fracture orientation at oblique spreading centersJournal of the Geological Society of London, Vol. 153, No. 2, Mar. pp. 185-190GlobalTectonics, Structure -fractures
DS200912-0071
2009
SandfordBraun, J., Burbidge, D.R., Gesto, Sandford, Gleadow, Kohn, CumminsConstraints on the current rate of deformation and surface uplift of the Australian continent from a new seismic database and low T thermochronological data.Australian Journal of Earth Sciences, Vol. 56, 2, pp. 99-110.AustraliaGeophysics - seismic
DS1993-0024
1993
Sandford, S.A.Allamandola, L.J., Sandford, S.A., Tielens, A.G.G.M., Herbst, T.M.Diamonds in dense molecular clouds: a challenge to the standard interstellar medium paradigM.Science, Vol. 260, April 2, pp. 64-66GlobalDiamond formation, Meteoritic
DS201711-2510
2017
SandFranca Lucas, G.Farrapo Albuquerque, D., SandFranca Lucas, G., MarceloAssumpcao, P.M., Lucas, M.B., CondoriQuispe, C., Oliveira, M.E.Crustal structure of the Amazonian craton and adjacent provinces in Brazil.Journal of South American Earth Sciences, Vol. 79, pp. 431-442.South America, Brazilcraton

Abstract: The study of the crust using receiver functions can provide valuable geological information, such as average crustal composition, its formation dynamics and the tectonic evolution of a region, as well as serve as an initial reference for the generation of seismic wave velocity models to improve earthquake location. To fill in gaps in information on the crust of the Amazonian Craton and adjacent provinces in Brazil, we used receiver functions and H-k stacking to estimate crustal thicknesses and the VP/VS ratios. The results indicate that the crust of the study region is predominantly felsic, with an average VP/VS around 1.73 and an average thickness of 38.2 km, with a range of 27.4-48.6 km. Minimum curvature interpolation of the crustal thickness values has made it possible to delimitate of the Amazonian Craton, which corresponds to the area with an average thickness equal to or greater than 39 km. In addition, it was possible to identify its potential cratonic blocks, as well as the Paranapanema Block of Paraná Basin. The geometry of the craton, defined by its crustal thickness, is corroborated by the distribution of natural seismicity that accompanies its edges. These are related to suture zones between the Amazonian, São Francisco/Congo and Paranapanema paleocontinents. The sedimentary basins that have undergone rifting processes have a thinner crust, usually less than 37 km thick. Due to the great variability of the results, it was not possible to determine a characteristic value of c
DS1990-1300
1990
Sandiford, M.Sandiford, M., Powell, R.Some isostatic and thermal consequences of the vertical strain geometry in convergent orogensEarth and Planetary Science Letters, Vol. 98, pp. 154-165GlobalOrogeny, Tectonics
DS1994-0318
1994
Sandiford, M.Coblentz, D.D., Richardson, R.M., Sandiford, M.On the gravitational potential of the Earth's lithosphereTectonics, Vol. 13, No. 4, August pp. 929-945MantleTectonics
DS1994-0319
1994
Sandiford, M.Coblentz, D.D., Sandiford, M.Tectonic stresses in the African plate: constraints on the ambient lithospheric stress state.Geology, Vol. 22, No. 9, September pp. 831-834.Mantle, AfricaTectonics, Model -lithosphere
DS1994-1523
1994
Sandiford, M.Sandiford, M., Coblenz, D.Plate scale potential energy distributions and the fragmentation of ageingplates.Earth Planetary Science Letters, Vol. 126, No. 1-3, August pp. 143-160.MantleTectonics, Plate tectonics
DS1995-0333
1995
Sandiford, M.Coblentz, D.D., Sandiford, M.The origin of the intraplate stress field in continental AustraliaEarth and Planetary Science Letters, Vol. 133, No. 3-4, July 15, pp. 299-309.AustraliaTectonics, Subduction
DS2000-0705
2000
Sandiford, M.Neumann, N., Sandiford, M., Foden, J.Regional geochemistry and continental heat flow implications for the origin of the South Australian....Earth and Planetary Science Letters, Vol.183, No.1-2, Nov.30, pp.107-20.Australia, southHeat flow anomaly
DS2001-0759
2001
Sandiford, M.McLaren, S., Sandiford, M.Long term thermal consequences of tectonic activity at Mt. Isa Australia: implications for polyphase tectonismGeological Society of London, Special Publication, Special Paper 184, pp. 219-36.AustraliaTectonics, geothermometry, Proterozoic, Craton
DS2001-1009
2001
Sandiford, M.Sandiford, M., Hand, M., McLaren, S.Tectonic feedback, intraplate orogeny and the geochemical structure of the crust: central perspectiveGeological Society of London, Special Publication, Special Paper 184, pp. 195-218.AustraliaTectonics
DS2002-0178
2002
Sandiford, M.Bodorkos, S., Sandiford, M., Oliver, N.H.S., Cawood, P.High T low P metamorphism in the Paleoproterozoic Halls Creek Orogen: the middle crustal response to mantle...Journal of Metamorphic Geology, Vol. 20, No. 2, pp. 217-38.Australia, northernGeothermometry - mantle related transient thermal pulse
DS2002-1393
2002
Sandiford, M.Sandiford, M., McLaren, S.Tectonic feedback and the ordering of heat producing elements within the continental lithosphere.Earth and Planetary Science Letters, Vol. 204, No. 1-2, pp. 133-150.MantleTectonics, plumes
DS200412-1276
2004
Sandiford, M.McLaren, S., Sandiford, M., Hand, M., Neumann, N., Wyborn, L.,Bastrkova, I.The hot southern continent: heat flow and heat production in Australian Proterozoic terranes.Hillis, R.R., Muller, R.D. Evolution and dynamics of the Australian Plate, Geological Society America Memoir, No. 372, pp. 157-168.AustraliaGeothermometry
DS200412-1728
2004
Sandiford, M.Sandiford, M.Neotectonics of southeastern Australia: linking the Quaternary faulting record with seismicity and in situ stress.Hillis, R.R., Muller, R.D. Evolution and dynamics of the Australian Plate, Geological Society America Memoir, No. 372, pp. 91-106.AustraliaGeophysics - seismics
DS200512-0707
2005
Sandiford, M.McLaren, S., Sandiford, M., Powell, R.Contrasting styles of Proterozoic crustal evolution: a hot plate tectonic model for Australian terranes.Geology, Vol. 33, 8, August pp. 673-676.AustraliaTectonics, rheology, geothermometry
DS200612-0144
2005
Sandiford, M.Bodorkos, S., Sandiford, M.Thermal and mechanical controls on the evolution of Archean crustal deformation: examples from western Australia.Benn, K., Mareschal, J-C., Condie, K.C. Archean Geodynamics and Environments, AGU Geophysical Monograph, No. 164, pp. 131-148.AustraliaGeothermometry
DS200612-1215
2006
Sandiford, M.Sandiford, M.Why are the continents just so?Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 3, abstract only.AustraliaTectonics
DS200612-1216
2006
Sandiford, M.Sandiford, M., McLarem, S.Thermo mechanical controls on heat production distributions and the long term evolution of the continents.Brown, M., Rushmer, T., Evolution and differentiation of the continental crust, Cambridge Publ., Chapter 3,MantleGeothermometry
DS200612-1217
2006
Sandiford, M.Sandiford, M., McLaren, S.Thermo-mechanical controls on heat production distributions and the long term evolution of the continents.Evolution and differentiation of Continental Crust, ed. Brown, M., Rushmer, T., Cambridge Univ. Press, Chapter 2, pp. 67-91.Mantle, MOHOGeothermometry
DS201012-0074
2010
Sandiford, M.Brown, R., White, R.W., Sandiford, M.On the importance of minding one's Ps and Ts: metamorphic processes and quantitative petrology.Journal of Metamorphic Geology, Vol. 28, 6, pp. 561-567.TechnologyUHP
DS201012-0656
2010
Sandiford, M.Sandiford, M.Why the continents just so?Journal of Metamorphic Geology, Vol. 28, 6, pp. 569-577.MantleMetamorphism
DS201511-1829
2015
Sandiford, M.Coblentz, D., Van Wijk, J., Richardson, R.M., Sandiford, M.The upper mantle geoid: implications for continental structure and the intraplate stress field.Geological Society of America Special Paper, No. 514, pp. SPE514-13.MantleGeophysics - seismics

Abstract: We use the fact that geoid anomalies are directly related to the local dipole moment of the density-depth distribution to help constrain density variations within the lithosphere and the associated tectonic stresses. The main challenge with this approach is isolating the upper mantle geoid contribution from the full geoid (which is dominated by sources in the lower mantle). We address this issue by using a high-pass spherical harmonic filtering of the EGM2008-WGS84 geoid to produce an "upper mantle" geoid. The tectonic implications of the upper mantle are discussed in terms of plate tectonics and intraplate stresses. We find that globally there is about a 9 meter geoid step associated with the cooling oceanic lithosphere that imparts a net force of ~2.5x1012 N/m in the form of "ridge push" - a magnitude that is consistent with 1-d models based on first-order density profiles. Furthermore, we ind a consistent 6 meter geoid step across passive a continental margin which has the net effect of educing the compressive stresses in the continents due to the ridge force. Furthermore, we use the pper mantle geoid to reevaluate the tectonic reference state which previously studies estimated using n assumption of Airy-based isostasy. Our evaluation of the upper mantle geoid confirms the near quivalence of the gravitational potential energy of continental lithosphere with an elevation of about 750 meters and the mid-ocean ridges. This result substantiates early conclusions about the tectonic reference state and further supports the prediction that continental regions are expected to be in a slightly extensional state of stress.
DS1960-0047
1960
Sandilands, J.S.Gallagher, W.S., Sandilands, J.S., Howell, T.V.Native Administration in the Kimberley Diamond MinesSouth African Institute of Mining and Metallurgy. Journal, Vol. 60, No. 5, PP. 500-502.South AfricaPolitics, Mining Methods, Recovery
DS1995-1861
1995
Sandilands, M.Swan, A., Sandilands, M.Introduction to geological dat a analysisBlackwell Science Publ, 446pGlobalBook -ad, Geological data analysis
DS2001-0398
2001
SandimirovaGornova, M.A., Tsypukov, Sandimirova, SmirnovaMelting of the Precambrian mantle: geochemistry of residual peridotites from peripheral blocks of PlatformDoklady Academy of Sciences, Vol. 378, No. 4, May-June pp. 379-82.Russia, SiberiaPeridotites, Mantle - melting
DS1994-1651
1994
Sandimirova, G.P.Sobachenko, V.N., Gundobin, A.G., Sandimirova, G.P., et al.Strontium isotopes in the rocks of formational type of near fault alkaline carbonate silicate metasomatites.Russian Geology and Geophysics, Vol. 35, No. 3, pp. 51-58.Russia, Urals, YeniseiGeochronology, Carbonatite
DS200512-0929
2004
Sandimirova, G.P.Sakhno, V.G., Maksimov, S.O., Popov, V.K., Sandimirova, G.P.Leucite basanites and potassium shonkinites of the Uglovoe Basin, southern Primorye.Doklady Earth Sciences, Vol. 399A, Nov-Dec. pp. 1322-1326.RussiaBasanites, Foidites
DS201312-0509
2013
Sandimirova, G.P.Kostrovitsky, S.I., Soloveva, L.V., Yakovlev, D.A., Suvorova, L.F., Sandimirova, G.P., Travin, A.V., Yudin, D.S.Kimberlites and megacrystic suite: isotope geochemical studies.Petrology, Vol. 21, 2, pp. 127-144.Russia, YakutiaDeposit - Udachnaya
DS201212-0377
2012
Sandmirova, G.P.Kostrovitsky, S.I., Kopylova, M.G., Egorov, K.N., Yakolev, D.A., Kalashnikova, T.V., Sandmirova, G.P.The exceptionally fresh Udachnaya -East kimberlite: evidence for brine and evaporite contamination.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractRussia, YakutiaDeposit - Udachnaya -east
DS201910-2260
2019
Sandner, T.Graf, C., Sandner, T., Woodland, A., Hofer, H., Seitz, H-M., Pearson, G., Kjarsgaard, B.Metasomatism, oxidation state of the mantle beneath the Rae craton, Canada.Goldschmidt2019, 1p. AbstractCanadacraton

Abstract: The Rae craton is an important part of the Canadian Shield and was amalgamated to the Slave craton at ?? 1.9 Ga [1]. Recent geophysical and geochemical data indicate a protracted geodynamic history [1, 2]. Even though the oxidation state of the Earth’s mantle has an important influence of fluid compositions and melting behavior, no data on the oxidation state of the Rae’s mantle are available. The aims of this study were to 1) determine the oxidation state (ƒO2) of the lithosphere beneath the Rae craton, 2) link these results to potential metasomatic overprints and 3) compare the geochemical evolution with the Slave craton. We studied 5 peridotite xenoliths from Pelly Bay (central craton) and 22 peridotites from Somerset Island (craton margin). Pelly Bay peridotites give T < 905°C and depths of ??80- 130 km. Garnets have depleted or “normal” REE patterns, the latter samples recording fO2 values ??0.5 log units higher. The deeper samples are more enriched and oxidised. Peridotites from Somerset Island record T ??825-1190°C, a ?logfO2 ranging from ?? FMQ - FMQ-3.6 from a depth interval of ??100-150 km. Garnets exhibit two REE signatures - sinusoidal and “normal” - indicating an evolutionary sequence of increasing metasomatic re-enrichment and a shift from fluid to melt dominated metasomatism. Compared to the Slave craton, the Rae mantle is more reduced at ??80km but becomes up to 2 log units more oxidised (up to ??FMQ-1) at ??100-130 km. Similar oxidising conditions can be found >140 km in the Slave mantle [3]. Especially under Somerset Island, the lithospheric mantle has contrasting fO2 and metasomatic overprints in the same depth range, which may represent juxtaposed old and rejuvenated domains [2].
DS202103-0422
2021
Sandner, T.Woodland, A.B., Graf, C., Sandner, T., Hofer, H.E., Seitz, H-M., Pearson, D.G., Kjarsgaard, B.A.Oxidation state and metasomatism of the lithospheric mantle beneath the Rae craton, Canada: strong gradients reflect craton formation and evolution.Nature Scientific Reports, 10.1038/s41598-021-83261-6 11p. PdfCanada, Northwest Territoriesmetasomatism

Abstract: We present the first oxidation state measurements for the subcontinental lithospheric mantle (SCLM) beneath the Rae craton, northern Canada, one of the largest components of the Canadian shield. In combination with major and trace element compositions for garnet and clinopyroxene, we assess the relationship between oxidation state and metasomatic overprinting. The sample suite comprises peridotite xenoliths from the central part (Pelly Bay) and the craton margin (Somerset Island) providing insights into lateral and vertical variations in lithospheric character. Our suite contains spinel, garnet-spinel and garnet peridotites, with most samples originating from 100 to 140 km depth. Within this narrow depth range we observe strong chemical gradients, including variations in oxygen fugacity (ƒO2) of over 4 log units. Both Pelly Bay and Somerset Island peridotites reveal a change in metasomatic type with depth. Observed geochemical systematics and textural evidence support the notion that Rae SCLM developed through amalgamation of different local domains, establishing chemical gradients from the start. These gradients were subsequently modified by migrating melts that drove further development of different types of metasomatic overprinting and variable oxidation at a range of length scales. This oxidation already apparent at ~?100 km depth could have locally destabilised any pre-existing diamond or graphite.
DS200912-0662
2009
Sandoghdar, V.Sandoghdar, V.Imaging: seeing diamond defects.Nature Photonics, Vol. 3, no. 3, pp. 133-134. Ingenta 1091168991TechnologyDiamond morphology
DS1988-0193
1988
Sandomirskaya, S.M.Egorov, K.N., Egorov, A.N., Sandomirskaya, S.M.Megacrystals of orthopyroxene from the Udachnaya kimberlite pipe.(Russian)Zap. Vses. Mineral. O-Va, (Russian), Vol. 117, No. 6, pp. 681-685RussiaMineralogy
DS1988-0609
1988
Sandomirskii, S.A.Sandomirskii, S.A., Zaichenko, M.V.Seperation of multicomponent geochemical anomalies related tokimberlitepipes.(Russian)Geokhim. Krit. Kolichestv. Otsenki Skryt. Orud., (Russian), pp. 13-18RussiaBlank
DS1984-0665
1984
Sandomirskiy, P.A.Sigalovskaya, YU.I., Sandomirskiy, P.A., Urosov, V.S.Crystallochemistry of MelilititeMineral. Zhur., Vol. 6, No. 2, PP. 3-16.RussiaMelilitite
DS1984-0666
1984
Sandomirsky, P.A.Sigalovskaya, YU.I., Sandomirsky, P.A., Urosov, V.S.The Crystal Chemistry of the MelilitesMineral. Zhurnal., Vol. 6, No. 2, PP. 3-16.RussiaMineral Chemistry
DS201810-2374
2018
Sandorne, J.K.Rosenthal, A., Yaxley, G.M., Crichton, W.A., Kovacs, I.J., Spandler, C., Hermann, J., Sandorne, J.K., Rose-Koga, E., Pelleter, A-A.Phase relations and melting of nominally 'dry' residual eclogites with variable CaO/Na2O from 3 to 5 Gpa and 1250 to 1500C; implications for refertilisation of upwelling heterogeneous mantle. Lithos, Vol. 314-315, pp. 506-519.Mantlemelting
DS200812-1240
2008
Sandovi, E.Wang, X., Ni, J.F., Aster, R., Sandovi, E., Wilson, D., Sine, C., Grand, S.P., Baldridge, W.S.Shear wave splitting and mantle flow beneath the Colorado Plateau and its boundary with the Great Basin.Bulletin of Seismological Society of America, Vol. 98, 5, pp. 2526-2532.United States, Colorado PlateauGeophysics - seismics
DS1994-1524
1994
Sandre. E., et al.Sandre. E., et al.An initial study of the gap opening within the graphite into diamond topological transformation.Journal of Phys. Ch. S., # QB349, Vol. 55, No. 11, Nov. pp. 1261-68.GlobalDiamond morphology
DS1989-1230
1989
Sandrone, R.Pognante, U., Sandrone, R.Eclogites in the northern Dora-Maira Nappe, Western Alps, ItalyMineralogy and Petrology, Vol. 40, No. 1, March pp. 57-72ItalyEclogite
DS201112-0905
2011
Sandu, C.Sandu, C., Lenardic, A., O'Neill, C.J., Cooper, C.M.Earth's evolving stress state and the past, present, and future stability of cratonic lithosphere.International Geology Review, In press, availableMantleConvection
DS201112-0906
2011
Sandu, C.Sandu, C., Lenardic, A., O'Neill, C.J., Cooper, C.M.Earth's evolving stress state and the past, present and future stability of cratonic lithosphere.International Geology Review, Vol. 53, 11-12, pp. 1392-1402.GlobalCraton
DS201112-0907
2011
Sandu, C.Sandu, C., Lenardic, A., O'Neill, C.J., Cooper, C.M.Earth's evolving stress state and the past, present, and future stability of cratonic lithosphere.International Geology Review, Vol. 53, no. 11-12, pp. 1392-1402.MantleCraton
DS200412-0020
2004
Sandvol, E.Al-Lazki, A.I., Sandvol, E., Seber, D., Barazangi, M., Turkelli, N., Mohamad, R.Pn tomographic imaging of mantle lid velocity and anisotropy at the junction of the Arabian, Eurasian and African plates.Geophysical Journal International, Vol. 158, 3, pp. 1024-1040.AfricaGeophysics - seismics, tomography
DS200512-0521
2005
Sandvol, E.Khan, S.D., Flower, M.F.J., Sultan, M.I., Sandvol, E.Introduction to TETHYS - an inter disciplinary GIS database for studying continental collisions.Journal of Asian Earth Sciences, In pressAsiaTectonics, remote sensing, database
DS200612-0696
2006
Sandvol, E.Khan, S.D., Flower, M.F.J., Sultan, M.I., Sandvol, E.Introduction to TETHYS - an inter disciplinary GIS database for studying continental collisions.Journal of Asian Earth Sciences, Vol. 26, 6, May pp. 613-625.MantleTectonics, computer database
DS200512-0931
2005
Sandwell, D.Sandwell, D., Anderson, D.L., Wessel, P.Global tectonic maps.Plates, Plumes, and Paradigms, pp. 1-10 ( total book 861p. $ 144.00)GlobalTectonics - overview
DS201605-0892
2016
Sanematsu, K.Sanematsu, K. , Watanabe, Y.Characteristics and genesis of ion adsorption type rare earth element deposits.SEG Reviews in Economic Geology, editors Verplanck, P.L., Hitzman, M.W., No. 18, pp. 55-80.GlobalRare earths
DS1960-0877
1967
Sanford, B.V.Sanford, B.V., Norris, A.W., Bostock, H.H.Geology of the Hudson Bay LowlandsGeological Survey of Canada Paper, No. 67-60OntarioHudson Bay Area
DS1990-1301
1990
Sanford, B.V.Sanford, B.V., Grant, A.C.New findings relating to the stratigraphy and structure of the HudsonPlatformGeological Survey of Canada Paper, Interior Plains and Arctic Canada, No. 90-1D pp. 17-30Ontario, ManitobaStructure, Hudson Platform
DS1998-1282
1998
Sanford, B.V.Sanford, B.V., Card, K.D., Grant, A.C., Okulitch, A.V.Bedrock geology, James Bay Ontario - District of Keewatin, NorthwestTerritories.Geological Survey of Canada Open file, No. 3558, 1:1, 000, 000 $ 26.00Ontario, Northwest TerritoriesMap - bedrock geology, James Bay Lowlands
DS1999-0113
1999
Sanford, B.V.Card, K.D., Sanford, B.V., Card, G.M.Controls on the emplacement of kimberlites and alkalic rock carbonatite complexes in the Canadian Shield. #2Exploration and Mining Geology, Vol. 6, No. 4, Oct. (1997) pp. 285-96.Canada, Ontario, Manitoba, Quebec, Baffin IslandKimberlites - structure, tectonics, Alkalic complexes
DS1999-0624
1999
Sanford, B.V.Sanford, B.V., Grant, A.C.Paleozoic and Mesozoic geology of the Hudson and southeast Arcticplatforms.Geological Survey Open File, No. 3595, 1: 2, 500, 000 $ 40.00Northwest Territories, Ontario, ManitobaMap
DS1992-1326
1992
Sanford, R.F.Sanford, R.F.The nature of environmentalisMSeg Newsletter, No. 9, April pp. 4, 5GlobalLegal, Environmental, Overview of issues
DS1993-1374
1993
Sanford, R.F.Sanford, R.F., Pierson, C.T., Crovelli, R.A.An objective replacement method for censored geochemical dataMathematical Geology, Vol. 25, No. 1, pp. 59-80GlobalGeochemistry, Environmental
DS1910-0432
1914
Sanford, S.Sanford, S., Stone, R.W.Useful Minerals of the U.s #1United Stated Geological Survey (USGS) Bulletin., No. 585, 250P. P. 29; 58; 72; 98; 143; 194.United States, Gulf Coast, Arkansas, Georgia, Indiana, Michigan, North CarolinaDiamond Occurrence
DS1910-0536
1917
Sanford, S.Sanford, S., Stone, R.W.Useful Minerals of the U.s. #2United States Geological Survey (USGS) Bulletin., No. 624, 412P.United States, Gulf Coast, Arkansas, Appalachia, Georgia, North CarolinaBlank
DS201708-1613
2017
Sang, C.Cheen, Y., Lim, E., Sang, C.Complex zoning of olivine in archetypal kimberlite provides new insights into the evolution of kimberlite magmas.11th. International Kimberlite Conference, PosterTechnologyOlivine
DS202101-0026
2020
Sangsawong, S.Pardieu, V., Sangsawong, S., Cornuz, L., Raynaud, V., Luetrakulprawat, S.Update on emeralds from the Mananjary-Irondo area, Madagascar.Journal of Gemology, Vol. 37, 4, pp. 416-425.Africa, Madagascaremerald
DS201808-1785
2018
Sangtawesin, S.Rose, B.C. ,Huang, D., Zhang, Z-H., Stevenson, P., Tyryshkin, A.M., Sangtawesin, S., Srinivasan, S., Loudin, L., Markham, M.L., Edmonds, A.M., Twitchen, D.J., Lyon, S.A., de Leon, N.P.Observation of an environmentally insensitive solid-state spin defect in diamond.Science , Vol. 361, July 6, p. 60-63.Technologysynthetic

Abstract: Engineering coherent systems is a central goal of quantum science. Color centers in diamond are a promising approach, with the potential to combine the coherence of atoms with the scalability of a solid-state platform. We report a color center that shows insensitivity to environmental decoherence caused by phonons and electric field noise: the neutral charge state of silicon vacancy (SiV0). Through careful materials engineering, we achieved >80% conversion of implanted silicon to SiV0. SiV0 exhibits spin-lattice relaxation times approaching 1 minute and coherence times approaching 1 second. Its optical properties are very favorable, with ~90% of its emission into the zero-phonon line and near -transform-limited optical linewidths. These combined properties make SiV0 a promising defect for quantum network applications.
DS200812-0601
2008
Sanina, I.Kozlovskaya, E., Kosarev, G., Aleshin, I., Riznichenko, O., Sanina, I.Structure and composition of the crust and upper mantle of the Archean Proterozoic boundary in the Fennoscandian Shield obtained by joint inversion.Geophysical Journal International, Vol. 175, 1, pp. 135-152.Europe, Scandinavia, Sweden, NorwayGeophysics - seismics
DS202202-0186
2021
Sanina, I.A.Adushkin, V.V., Goev, A.G., Sanina, I.A., Fedorov, A.V.The deep velocity structure of the Central Kola Peninsula obtained using the receiver function technique.Doklady Earth Sciences, Vol. 501, pp. 1049-1051.Russia, Kola Peninsulageophysics - seismics

Abstract: New results are presented on the features of the deep velocity structure of two of the three main tectonic blocks that make up the Kola region-Murmansk and Belomorskii-by the P receiver function technique. The research is based on data from the broadband seismic stations Teriberka and Kovda. The results are compared with the models obtained by mutual inversion of PRF and SRF using the data from the stations Apatity and Lovozero. It is shown that the crust has a two-layer structure with the border at a depth of 11 km under the Murmansk block and at a depth of 15 km under the Kola and Belomorskii blocks. The crust thickness of the Murmansk, Belomorskii, and Kola blocks are 35, 33, and 40 km, respectively. The presence of the MLD was revealed in all tectonic structures analyzed for the first time, with a top at a depth of about 70 km for the Murmansk and Belomorskii blocks and 90 km for the Kola block and a bottom at 130-140 km for all structures.
DS201612-2291
2016
Sanislav, I.V.Cook, Y.A., Sanislav, I.V., Hammerli, J., Blenkinsop, T.G., Dirks, P.H.G.M.A primitive mantle source for the Neoarchean mafic rocks from the Tanzania Craton.Geoscience Frontiers, Vol. 7, pp. 911-926.Africa, TanzaniaMantle

Abstract: Mafic rocks comprising tholeiitic pillow basalt, dolerite and minor gabbro form the basal stratigraphic unit in the ca. 2.8 to 2.6 Ga Geita Greenstone Belt situated in the NW Tanzania Craton. They outcrop mainly along the southern margin of the belt, and are at least 50 million years older than the supracrustal assemblages against which they have been juxtaposed. Geochemical analyses indicate that parts of the assemblage approach high Mg-tholeiite (more than 8 wt.% MgO). This suite of samples has a restricted compositional range suggesting derivation from a chemically homogenous reservoir. Trace element modeling suggests that the mafic rocks were derived by partial melting within the spinel peridotite field from a source rock with a primitive mantle composition. That is, trace elements maintain primitive mantle ratios (Zr/Hf = 32-35, Ti/Zr = 107-147), producing flat REE and HFSE profiles [(La/Yb)pm = 0.9-1.3], with abundances of 3-10 times primitive mantle and with minor negative anomalies of Nb [(Nb/La)pm = 0.6-0.8] and Th [(Th/La)pm = 0.6-0.9]. Initial isotope compositions (?Nd) range from 1.6 to 2.9 at 2.8 Ga and plot below the depleted mantle line suggesting derivation from a more enriched source compared to present day MORB mantle. The trace element composition and Nd isotopic ratios are similar to the mafic rocks outcropping ?50 km south. The mafic rocks outcropping in the Geita area were erupted through oceanic crust over a short time period, between ?2830 and ?2820 Ma; are compositionally homogenous, contain little to no associated terrigenous sediments, and their trace element composition and short emplacement time resemble oceanic plateau basalts. They have been interpreted to be derived from a plume head with a primitive mantle composition.
DS201804-0733
2017
Sanislav, I.V.Sanislav, I.V., Blenkinsop, T.G., Dirks, P.H.G.M.Archean crustal growth through successive partial melting events in an oceanic plateau like setting in the Tanzanian craton.Terra Nova, pp. 1-10.Africa, Tanzaniacraton - geochronology

Abstract: The detrital zircon population in quartzitic conglomerates from the northern Tanzania Craton yield ages between 2640 Ma and 2790 Ma which includes most of the igneous history from this part of the craton. The igneous evolution is characterised by mafic volcanism with an oceanic plateau?like geochemical signature at ~2800 Ma followed by diorite and tonalite-trondhjemite-granodiorite dominated magmatism between 2790 and 2700 Ma, which transitioned into more evolved high?K magmatism between 2700 and 2620 Ma. The ?Hf values of the detrital zircons range from +2.4 to ?1.4 and change with time from radiogenic Hf pre?2700 Ma (98% positive ?Hf) to unradiogenic Hf post?2700 Ma (41% positive ?Hf). The petrological progression from mafic to felsic crust is reflected in the detrital age distribution and Hf isotopes and is consistent with juvenile mafic crust slowly maturing into more evolved felsic crust through a series of successive partial melting events in an oceanic?plateau?like environment.
DS201312-0631
2013
Sanjeevi, S.Nandini, C.V., Sanjeevi, S., Bhaskar, A.S.An integrated approach to map certain paleochannels of south India using remote sensing, geophysics, and sedimentological techniques.International Journal of Remote Sensing, Vol. 34, no. 19, pp. 6507-6528.IndiaPaleochannels
DS201112-0908
2010
Sankar, K.R.Sankar, K.R.Geological prospects and perspectives of mineral deposits in Andhra Pradesh State.... pages for diamond related information.Thesis, Doctor of Philosophy in Geology, Andhra University, extracted pp. 51-53; history pp. 75-77;pp.188-191;204-5India, Andhra PradeshDiamond - brief overview and history
DS2001-1010
2001
Sankaran, A.V.Sankaran, A.V.Stability of ancient cratons and lithospheric mantle compositionCurrent Science, Vol. 81, No. 9, Nov. 10, pp. 1158-9.MantleCraton, Mineral chemistry
DS200412-1729
2004
Sankaran, A.V.Sankaran, A.V.Oxidation of iron sans oxygen fugacity: fresh insights from lower mantle mineral chemistry.Current Science, Vol. 87,5, Sept. 10, pp. 555-556.MantleRedox
DS200512-0932
2004
Sankaran, A.V.Sankaran, A.V.The row over Earth's mantle plume concept.Current Science, Vol. 87, 9, Nov. 10, pp. 1170-1172.MantleModel
DS200512-0933
2005
Sankaran, A.V.Sankaran, A.V.Earth's mantle: old concepts change yielding place to new.Current Science, Vol. 88, 11, June 10, pp. 1727-1728.MantleGeophysics - seismics, layers
DS200612-1218
2006
Sankaran, A.V.Sankaran, A.V.Timing the beginning of continental crust formation.Current Science, Vol. 90, 7, April 10, pp. 905-906.MantleGeochronology, geochemistry
DS200612-1219
2006
Sankaran, A.V.Sankaran, A.V.Material transfer across Earth's core mantle boundary: recent perceptions.Current Science, Vol. 90, 3, Feb. 10, pp. 284-285.MantleTectonics
DS200612-1220
2006
Sankaran, A.V.Sankaran, A.V.When did plate tectonics begin?Current Science, Vol. 90, 12, pp. 1596-1597.MantleTectonics
DS200712-0936
2007
Sankaran, A.V.Sankaran, A.V.Oceans of mineral bound water in Earth's lower mantle: seismic study confirms earlier speculations.Current Research, Vol. 92, 10, May 25, pp. 1340-1342.MantleSlab water
DS200712-0937
2007
Sankaran, A.V.Sankaran, A.V.Oceans of mineral bound water in Earth's lower mantle: seismic study confirms earlier speculations.Current Science, Vol. 92, 10, May 25, pp. 1340-1342.MantleWater
DS200812-1003
2007
Sankaran, A.V.Sankaran, A.V.The unsettled plume hypothesis.Current Science, Vol. 91, 10, Nov. 25, pp. 1344-45.MantlePlume theory
DS2002-1394
2002
Sankaranm, A.V.Sankaranm, A.V.Mantle convection results from plate tectonics - fresh hypothesis reverses current..Current Science, Vol. 82,7,pp.785-7., Vol. 82,7,pp.785-7.MantleTectonics
DS2002-1395
2002
Sankaranm, A.V.Sankaranm, A.V.Mantle convection results from plate tectonics - fresh hypothesis reverses current..Current Science, Vol. 82,7,pp.785-7., Vol. 82,7,pp.785-7.MantleTectonics
DS2002-1396
2002
Sankaron, A.V.Sankaron, A.V.Mantle convection results from plate tectonics - fresh hypothesis reverses current views.Current Science, Vol. 82,7, April 10, pp. 785-87.MantleTectonics - theory
DS1986-0703
1986
SankerSarma, S.V.S., Harinarayana, T., Venogopala, Krishna, C., SankerTellurics in the exploration of kimberlite pipes- an experimental studyCurrent Science, Vol. 55, No. 3, pp. 133-136IndiaWajrakarur, LattavaraM., Geophysics
DS1981-0344
1981
Sanker narayan, P.V.Rao, D.A., Sanker narayan, P.V.Structural Control of Emplacement of Kimberlite Pipes at Panna- a Suggestion from Aeromagnetics.Geoexploration., Vol. 19, PP. 207-228.India, Madhya PradeshKimberlite, Geophysics, Airmag
DS1997-0265
1997
Sankov, V.Delvaux, D., Moeys, R., Sankov, V.Paleostress reconstructions and geodynamics of the Baikal region, centralAsia, part 2, Cenozoic rifting.Tectonophysics, Vol. 282, No. 1-4, Dec. 15, pp. 1-38.GlobalTectonics, Baikal region
DS2003-0849
2003
Sankov, V.A.Lukhnev, A.V., Sankov, V.A., et al.New dat a on recent tectonic deformations in the South Mountainous framing of theDoklady Earth Sciences, Vol. 389, 2, p. 263-66.RussiaTectonics
DS200412-1183
2003
Sankov, V.A.Lukhnev, A.V., Sankov, V.A., et al.New dat a on recent tectonic deformations in the South Mountainous framing of the Siberian platform.Doklady Earth Sciences, Vol. 389,2,p. 263-66.RussiaTectonics
DS201012-0323
2010
SanloupJavoy, M., Kaminski, E., Guyot,Andrault, Sanloup, Moreira, Labrosse, Jambon, Agrinier.Davaille, JaupartThe chemical composition of the Earth: enstatite chondrite models.Earth and Planetary Science Letters, Vol. 293, 3-4, pp. 259-268.MantleChemistry
DS201112-0909
2011
Sanloup, C.Sanloup, C., Van Westrenen, W., Dasgupta, R., Maynard-Casely, H., Perrillat, J-P.Compressability change in iron-rich melt and implications for core formation models.Earth and Planetary Science Letters, Vol. 306, 1-2, pp. 118-122.MantleMelting
DS201412-0151
2014
Sanloup, C.Crepisson, C., Morard, G., Bureau, H., Prouteau, G., Morizet, Y., Petitgirard, S., Sanloup, C.Magmas trapped at the continental lithosphere-asthenosphere boundary.Earth and Planetary Science Letters, Vol. 393, pp. 105-112.MantleBoundary, magmatism
DS202002-0206
2020
Sanloup, C.McCammon, C., Bureau, H., Cleaves II, H.J., Cottrell, E., Dorfman, S.M., Kellogg, L.H., Li, J., Mikhail, S., Moussallam, Y., Sanloup, C., Thomson, A.R., Brovarone, A.V.Deep Earth carbon reactions through time and space. ( mentions diamond)American Mineralogist, Vol. 105, pp. 22-27.Mantlesubduction

Abstract: Reactions involving carbon in the deep Earth have limited manifestations on Earth's surface, yet they have played a critical role in the evolution of our planet. The metal-silicate partitioning reaction promoted carbon capture during Earth's accretion and may have sequestered substantial carbon in Earth's core. The freezing reaction involving iron-carbon liquid could have contributed to the growth of Earth's inner core and the geodynamo. The redox melting/freezing reaction largely controls the movement of carbon in the modern mantle, and reactions between carbonates and silicates in the deep mantle also promote carbon mobility. The 10-year activity of the Deep Carbon Observatory has made important contributions to our knowledge of how these reactions are involved in the cycling of carbon throughout our planet, both past and present, and has helped to identify gaps in our understanding that motivate and give direction to future studies.
DS201605-0893
2016
Sanloup. C.Sanloup. C.Density of magmas at depth.Chemical Geology, Vol. 429, pp. 51-59.MantleMagmatism

Abstract: Knowing the density of silicate liquids at high pressure is essential to answer questions relevant to the presence of magmas at depth, whether that be in the present Earth or in its earliest times, during differentiation of the planet. Melts have unique physical and chemical properties, which vary as a function pressure, and chemical composition. The focus here will be on in situ measurements of the density of magmas, with a presentation of the available methods and of the main results obtained so far, including why some magmas may be trapped at depth. Understanding the macroscopical physical properties of magmas requires an accurate microscopic structural description. Structural descriptions of compressed magmas are becoming more widely available, from experiments and from theoretical calculations. These structural inputs are used to understand the compression mechanisms at stake in the densification of magmas, e.g. the collapse of voids, coordination increase for the major cations, and bond compressibility. These densification processes profoundly affect not only the physical properties of the melt, but also its chemical properties, i.e. the way element partition between the magma and a metallic melt or between the magma and crystals.
DS202003-0367
2020
Sannel, A.B.K.Turetsky, M.R., Abbott, B.W., Jones, M.C., Walter Anthony, K.. Olefeldt, D., Schuur, E.A.G., Grosse, G., Kuhry, P., Higelius, G., Koven, C., Lawrence, D.M., Gibson, C., Sannel, A.B.K., McGuire, A.D.Carbon release through abrupt permafrost thaw. ( not specific to diamonds but interest)Nature Geoscience, Vol. 13, pp. 138-143.Mantlecarbon

Abstract: The permafrost zone is expected to be a substantial carbon source to the atmosphere, yet large-scale models currently only simulate gradual changes in seasonally thawed soil. Abrupt thaw will probably occur in <20% of the permafrost zone but could affect half of permafrost carbon through collapsing ground, rapid erosion and landslides. Here, we synthesize the best available information and develop inventory models to simulate abrupt thaw impacts on permafrost carbon balance. Emissions across 2.5?million?km2 of abrupt thaw could provide a similar climate feedback as gradual thaw emissions from the entire 18?million?km2 permafrost region under the warming projection of Representative Concentration Pathway 8.5. While models forecast that gradual thaw may lead to net ecosystem carbon uptake under projections of Representative Concentration Pathway 4.5, abrupt thaw emissions are likely to offset this potential carbon sink. Active hillslope erosional features will occupy 3% of abrupt thaw terrain by 2300 but emit one-third of abrupt thaw carbon losses. Thaw lakes and wetlands are methane hot spots but their carbon release is partially offset by slowly regrowing vegetation. After considering abrupt thaw stabilization, lake drainage and soil carbon uptake by vegetation regrowth, we conclude that models considering only gradual permafrost thaw are substantially underestimating carbon emissions from thawing permafrost.
DS2001-0581
2001
SanoKatayama, I., Maruyama, Parkinson, Terada, SanoIon micro probe uranium-lead (U-Pb) zircon geochronology of peak and retrograde stages of ultrahigh pressure metamorphic...Earth and Planetary Science Letters, Vol. 188, No. 1, May 30, pp.185-198.Russia, KazakhstanGeochronology - ultra high pressure (UHP), Kokchetav Massif
DS2001-1275
2001
SanoYamamoto, J., Watanabe, M., Nozaki, SanoHelium and carbon isotopes in fluorites: implications for mantle carbon contribution ancient subduction zoneJournal of Volc. Geotherm. Res., Vol. 107, No. 1-3, pp. 19-26.JapanCarbon - not specific to diamonds
DS2002-0798
2002
Sano, A.Kabo, T., Ohtani, E., Kondo, T., Kato, T., Toma, M., Hosoya, T., Sano, A.Metastable garnet in oceanic crust at the top of the lower mantleNature, No. 6917, Dec. 19, pp. 803-5.MantleGarnet mineralogy
DS200512-0645
2005
Sano, A.Litasov, K., Ohtani, E., Sano, A., Suzuki, A., Funakoshi, K.In situ X-ray diffraction study of post spinel transformation in a peridotite mantle: implication for the 660 km discontinuity.Earth and Planetary Science Letters, Vol.238, 3-4, pp. 311-328.MantleUHP, ringwoodite, perovskite
DS200612-0601
2005
Sano, A.Hosoya, T., Kubo, T., Ohtaini, E., Sano, A., Funakoshi, K.Water controls the fields of metastable olivine in cold subducting slabs.Geophysical Research Letters, Vol. 32, 17, Sept. 16, pp.Li7305-06.MantleSubduction
DS200612-1221
2006
Sano, A.Sano, A., Ohtani, E., Litasov, K., Kubo, T., Hosoya, T., Funakoshi, K., Kikegawa, T.In situ x-ray diffraction study of the effect of water on the garnet perovksite transformation in MORB and implications for the penetration of oceanic crust...Physics of the Earth and Planetary Interiors, Vol. 159, 1-2, pp. 118-126.MantleWater in lower mantle
DS200712-0632
2006
Sano, A.Litasov, K.D., Ohtani, E., Sano, A.Influence of water on major phase transitions in the Earth's mantle.American Geophysical Union, Geophysical Monograph, No. 168, pp. 95-112.MantleWater
DS201610-1853
2014
Sano, M.Chirico, P.G., Malpeti, K.C., Van Bockstael, M., Mamandou, D., Cisse, K., Diallo, T.A., Sano, M.Alluvial diamond resource potential and production capacity assessment of Guinea.U.S. Geological Survey, Report 2012-5256, 49p.Africa, GuineaAlluvials, resources

Abstract: In May of 2000, a meeting was convened in Kimberley, South Africa, by representatives of the diamond industry and leaders of African governments to develop a certification process intended to assure that export shipments of rough diamonds were free of conflict concerns. Outcomes of the meeting were formally supported later in December of 2000 by the United Nations in a resolution adopted by the General Assembly. By 2002, the Kimberley Process Certification Scheme (KPCS) was ratified and signed by diamond-producing and diamond-importing countries. The goal of this study was to estimate the alluvial diamond resource endowment and the current production capacity of the alluvial diamond mining sector of Guinea. A modified volume and grade methodology was used to estimate the remaining diamond reserves within Guinea’s diamondiferous regions, while the diamond-production capacity of these zones was estimated by inputting the number of artisanal miners, the number of days artisans work per year, and the average grade of the deposits into a formulaic expression. Guinea’s resource potential was estimated to be approximately 40 million carats, while the production capacity was estimated to lie within a range of 480,000 to 720,000 carats per year. While preliminary results have been produced by integrating historical documents, five fieldwork campaigns, and remote sensing and GIS analysis, significant data gaps remain. The artisanal mining sector is dynamic and is affected by a variety of internal and external factors. Estimates of the number of artisans and deposit variables, such as grade, vary from site to site and from zone to zone. This report has been developed on the basis of the most detailed information available at this time. However, continued fieldwork and evaluation of artisanally mined deposits would increase the accuracy of the results.
DS1994-1525
1994
Sano, Y.Sano, Y., Nagao, K., Pillinger, C.T.Carbon and noble gases in Archean chertChemical Geology, Vol. 112, No. 3-4, February 10, pp. 327-342GlobalChert, Geochemistry
DS1996-1250
1996
Sano, Y.Sano, Y., Williams, S.W.Fluxes of mantle and subducted carbon along convergent plate boundariesGeophysical Research. Letters, Vol. 23, No. 20, Oct. 1, pp. 2749-52.MantleTectonics, Subduction
DS2000-0848
2000
Sano, Y.Sa Carneiro Chaves, M.L., Dussin, T.M., Sano, Y.The source of the Espinhaco diamonds: evidences from Shrimp uranium-lead (U-Pb) zircon ages of Sopa conglomerate....Revista Brasileira e Geociencas, Vol. 30, No. 2, pp. 265-9.Brazil, Minas GeraisGeochronology, Deposit - Espinhaco
DS2002-0857
2002
Sano, Y.Kiykawa, S., Taira, A., Byrne, T., Bowring, S., Sano, Y.Structural evolution of the middle Archean coastal Pilbara terrane, western AustraliaTectonics, Vol. 21, No. 5, 10.1029/2001TC001296.AustraliaTectonics - structure
DS2002-1397
2002
Sano, Y.Sano, Y.Ion microprobe Lead-Lead dating of carbonado, polycrystalline diamondPrecambrian Research, Vol. 113, No. 1-2, pp. 155-68.Brazil, Minas GeraisGeochronology, Carbonado
DS2002-1398
2002
Sano, Y.Sano, Y., Yokochi, R., Terada, K., Chaves, M.L.,OzimaIon microprobe Pb Pb dating of carbonado, polycrystalline diamondPrecambrian Research, Vol. 113, No. 1-2, pp. 155-68.GlobalCarbonado, lead, geochronology
DS200712-0256
2007
Sano, Y.Dobrzhinetskaya, L., Takahata, N., Sano, Y., Green, H.W.Fluid organic matter interaction at high pressure and temperature: evidence from metamorphic diamonds.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p. 279.Russia, Kazakhstan, Europe, GermanyKokchetav and Erzgebirge
DS200712-0257
2007
Sano, Y.Dobrzhinetskaya, L., Takahata, N., Sano, Y., Green, H.W.Fluid organic matter interaction at high pressure and temperature: evidence from metamorphic diamonds.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p. 279.Russia, Kazakhstan, Europe, GermanyKokchetav and Erzgebirge
DS201212-0601
2012
Sano, Y.Roulleau, E., Pinti, D.L., Stevenson, R.K., Takahata, N., Sano, Y., Pitre, F.N, Ar and Pb isotopic co-variation in magmatic minerals: discriminating fractionation processes from magmatic sources in Montregian Hills, Quebec, Canada.Chemical Geology, Vol. 326-327, pp. 123-131.Canada, QuebecAlkalic
DS201506-0292
2015
Sano, Y.Pinti, D., Ishida, A., Takahata, N., Sano, Y.Carbon isotopes in a Juin a diamond with carbonate inclusions.Japan Geoscience Union Meeting, SCG16-05 May 28 abstractSouth America, BrazilDeposit - Juina
DS201809-2023
2018
Sano, Y.Fukuyama, K., Kagi, H., Inoue, T., Shinmei, T., Kakizawa, S., Takahata, N., Sano, Y.in corporation of nitrogen into lower mantle minerals under high pressure and high temperature.Goldschmidt Conference, 1p. AbstractMantlenitrogen

Abstract: Nitrogen occupies about 80% of the Earth 's atmosphere and had an impact on the climate in the early Earth. However, the behavior of nitrogen especially in the deep Earth is still unclear. Nitrogen is depleted compared to other volatile elements in deep mantle (Marty et al., 2012). "Missing" nitrogen is an important subject in earth science. In this study, we compared nitrogen incorporation into lower-mantle minerals (bridgmanite, periclase and stishovite) from high-temperature high-pressure experiment using multianvil apparatus installed at Geodynamics Research Center, Ehime University under the conditions of 27 GPa and 1600°C-1900°C. In these experiments, we used Fe-FeO buffer in order to reproduce the redox state of the lower mantle. Two types of starting materials: a powder mixture of SiO2 and MgO and a powder mixture of SiO2, MgO, Al2O3 and Mg(OH)2 were used for starting materials. Nitrogen in recovered samples was analyzed using NanoSIMS installed at Atmosphere and Ocean Research Institute. A series of experimental results revealed that stishovite and periclase can incorporate more nitrogen than bridgmanite. This suggests that periclase, the major mineral in the lower mantle, may be a nitrogen reservoir. Furthermore, the results suggest that stishovite, which is formed by the transition of the SiO2-rich oceanic crustal sedimentary rocks transported to the lower mantle via subducting slabs, can incorporate more nitrogen than bridgmanite (20 ppm nitrogen solubility reported by Yoshioka et al. (2018)). Our study suggests that nitrogen would continue to be supplied to the lower mantle via subducting slabs since approximate 4 billion years ago when the plate tectonics had begun, forming a "Hidden" nitrogen reservoir in the lower mantle.
DS1998-1283
1998
SaNo. Y.SaNo. Y., Takahata, N., Marty, B.Nitrogen recycling in subduction zonesGeophysical Research. Letters, Vol. 25, No. 13, Jul. 1, pp; 2289-92.MantleSubduction
DS1940-0189
1948
Sansom, W.J.Sansom, W.J.Arkansaw Diamond Mine. #1The Gemologist., Vol. 17, PP. 58-65.United States, Gulf Coast, Arkansas, PennsylvaniaEvaluation
DS1991-1496
1991
Sant, D.A.Sant, D.A., Karanth, R.V., Jadhav, P.C.A note on the occurrence of carbonatite dykes in the Lower Narmada ValleyJournal of Geological Society India, Vol. 37, Feb. pp. 119-127IndiaCarbonatite, Petrology
DS201801-0062
2017
Sant, D.A.Shitole, A., Sant, D.A., Parvez, I.A., Rangarajan, G., Patel, S., Viladkar, S.G., Murty, A.S.N., Kumari, G.Shallow seismic studies along Amba Dongar to Sinhada ( longitude 74 3 50E) transect, western India.Carbonatite-alkaline rocks and associated mineral deposits , Dec. 8-11, abstract p. 16.Indiadeposit - Amba Dongar

Abstract: The microtremor method is applied to map subsurface rheological boundaries (stratigraphic, faults and plutons) is based on strong acoustic impedance across contrasting density of rock/ sediment/ weathered interfaces up to shallow depths along longitude 74° 3'50" E from village Amba Dongar (latitude: 21° 59'N) up to Sinhada village (latitude: 22° 14' N). The 30 km long transect exposes variety of rocks viz., unclassified granite gneisses and metasediments (Precambrian age); sediments belonging to Bagh Group (Late Cretaceous); alkaline - carbonatite plutons and lava flows belonging to Deccan Traps (Late Cretaceous). In all, sixty stations were surveyed along the longitude 74° 3'50" E with spacing of 500 m. H/V spectral ratio technique reveals four rheological interfaces identified by resonant frequencies (fr) ranges 0.2213 to 0.7456 Hz (L1), 1.0102 to 3.076 Hz (L2), 4.8508 to 21.0502 Hz (L3), and 24.5018 to 27.1119 Hz (L4). L1 represents interface between plutons, Precambrian basement rocks; L2 represents interface between Bagh sediments, Deccan Traps and intrusives whereas L3 and L4 captures depth of top most weathered profile. We estimate the depth range for L1 L2 L3 and L4 using equation (h = 110.18fr?1.97) derived based on Deep Banni Core (1764 m deep from surface: DGH record). Deep Banni Core has a distinct interface between Mesozoic rocks and Precambrian basement. The depths are further compared with terrain-based equation. Further, the overall results from the present study are compared with seismic refraction studies along Phangia-Kadipani (NGRI Technical Report, 2003). The subsurface profile across longitude 74° 3'50" E educe faults that bound Bagh Group of rocks with Deccan Trap and Precambrian. We identify two plutons underneath three zones of intrusive viz., Amba Dongar Carbonatite Complex (Station 1 to 8), Tiloda Alkaline (station 33 to 44) and Rumadia Alkaline (station 46 to 51). The present study demarcates the presence of depression over Amba Dongar hill (station 1 to 3), filled by post carbonatite basalt earlier reported by Viladkar et al., (1996 and 2005) suggesting caldera morphology. Similarly, studies identify intrusive-pluton interfaces one, below the Amba Dongar hill, and second between village Tiloda and Rumadia at depth of ~500 m from the surface. Microtremor survey further depicts both basement morphology and thickness of Bagh Group and Deccan Traps.
DS1994-1526
1994
Santa Rosa, A.N.C.Santa Rosa, A.N.C., Rosa, J.W.C.Group velocity of fundamental mode Rayleigh waves recorded Belem- dat a set for Nazca plate motions.International Symposium Upper Mantle, Aug. 14-19, 1994, pp. 142-144.BrazilGeophysics -Rayleigh, Plate tectonics
DS201811-2619
2018
Santamaria, J.Xu, J., Melgarejo, J.C., Castillo, O., Montgarri, A., Laia, S., Santamaria, J.Ilmenite generations in kimberlite from Banankoro, Guinea. ConakryNeues Jahrbuch fur Mineralogie, doi:.org/10.1127/njma/2018/0096Africa, Guineadeposit - Banakoro

Abstract: A complex mineral sequence in a kimberlite from the Banankoro Cluster (Guinea Conakry) has been interpreted as the result of magma mixing processes. The composition of the early generations of phlogopite and spinel suggest direct crystallisation of a kimberlitic magma. However, the compositional trends found in the late generations of phlogopite and spinels could suggest magma mixing. In this context, four ilmenite generations formed. The first generations (types 1 and 2) are geikielitic and are associated with spinel and phlogopite which follow the kimberlitic compositional trends. They are interpreted as produced by crystallization from the kimberlite magma. A third generation of euhedral tabular Mg-rich ilmenite (type 3) formed during the interval between two generations of serpentine. Finally, a late generation of Mn-rich ilmenite (type 4) replaces all the Ti-rich minerals and is contemporaneous with the last generation of serpophitic non-replacing serpentine. Therefore, the formation of type 3 and type 4 ilmenite took place after the crystallization of the groundmass, during late hydrothermal process. Our results suggest a detailed textural study is necessary when use Mg-rich and Mn-rich ilmenites as KIMs.
DS201901-0093
2018
Santamaria, J.Xu, J., Melgarejo, C.M., Castillo-Oliver, M., Arques, L., Santamaria, J.Ilmenite generations in kimberlite from Banankoro, Guinea Conakry.Neues Jhabuch fur Mineralogie, Vol. 195, 3, pp. 191-204.Africa, Guineadeposit - Banankoro

Abstract: A complex mineral sequence in a kimberlite from the Banankoro Cluster (Guinea Conakry) has been interpreted as the result of magma mixing processes. The composition of the early generations of phlogopite and spinel suggest direct crystallisation of a kimberlitic magma. However, the compositional trends found in the late generations of phlogopite and spinels could suggest magma mixing. In this context, four ilmenite generations formed. The first generations (types 1 and 2) are geikielitic and are associated with spinel and phlogopite which follow the kimberlitic compositional trends. They are interpreted as produced by crystallization from the kimberlite magma. A third generation of euhedral tabular Mg-rich ilmenite (type 3) formed during the interval between two generations of serpentine. Finally, a late generation of Mn-rich ilmenite (type 4) replaces all the Ti-rich minerals and is contemporaneous with the last generation of serpophitic non-replacing serpentine. Therefore, the formation of type 3 and type 4 ilmenite took place after the crystallization of the groundmass, during late hydrothermal process. Our results suggest a detailed textural study is necessary when use Mg-rich and Mn-rich ilmenites as KIMs. © 2018 E. Schweizerbart’sche Verlagsbuchhandlung, Stuttgart, Germany.
DS200612-0325
2006
Santan, S.Delgnacio, C., Muoz, M., Sagredo, J., Fernandez, Santan, S., JohanssonIsotope geochemistry and FOZO mantle component of the alkaline carbonatitic association of Fuerteventura, Canary Islands, Spain.Chemical Geology, Vol. 232, 3-4, pp. 99-113.Europe, Spain, Canary IslandsCarbonatite
DS201112-0910
2010
Santana, E.F.Santana, E.F.Placeres diamantiferos do Rio Itiquira MT - Brasil.5th Brasilian Symposium on Diamond Geology, Nov. 6-12, abstract p. 58-59.South America, Brazil, Mato GrossoOverview of area of activity
DS201112-0960
2010
Santana de Britto, R.Silveira, F.V., Santana de Britto, R.Projeto diamante Brasil: estudo das provincias kimberlitcas e areas diamantiferas do Brasil.5th Brasilian Symposium on Diamond Geology, Nov. 6-12, abstract p. 13.South America, BrazilGeobank database
DS1990-1041
1990
Santer, B.D.Mikolajewicz, U., Santer, B.D., Maier-Reimer, E.Ocean response to green house warmingNature, Vol. 345, June 14, pp. 589-593OceanGreenhouse, Climate
DS1975-1208
1979
Santiago, D.J.Santiago, D.J.A Gravity and Magnetic Study of the Medford Anomaly, North Central oklahoma.Msc. Thesis, University Oklahoma., GlobalMid-continent
DS1998-1184
1998
Santiago, S.P.Pratico, V.P., Santiago, S.P.Metallic and industrial mineral assessment report on exploration for precious metals and diamond indicatorsAlberta Geological Survey, MIN 19980001, 3 CD's.Alberta, Fort McMurrayExploration - assessment
DS2001-0618
2001
SantinKogarko, L.N., Ryabchikov, I.D., Brey, Santin, PachecoMantle rocks uplifted to crustal levels: diffusion profiles in minerals spinel plagioclase lherzolitesGeochemistry International, Vol. 39, No. 4, pp. 311-26.GlobalLherzolites, Tallante area
DS201112-0911
2011
Santini, S.Santini, S., Tallarico, A., Dragoni, M.Magma ascent and effusion from a tensile fracture propogating to the Earth's urface.Geophysical Journal International, in press available,MantleMineral physics, rheology, heat flow, plumes
DS1989-1335
1989
Santner, T.J.Santner, T.J., Duffy, D.E.Statistical analysis of discrete dataSpringer Verlag Texts in Statistics, 367p. approx.$ 45.00GlobalGeostatistics, Book -Statistics
DS1991-1289
1991
Santokh Singh, D.Palmer, C.D., Santokh Singh, D.Osborne and Chappel's worldwide experience in alluvial mining during the1980'sAlluvial Mining, Institute of Mining and Metallurgy (IMM) Special Volume, pp. 327-346Sierra LeoneAlluvial mining, Mining applications
DS200412-1745
2004
Santoro, L.Schena, G., Favretto, S., Santoro, L., Pasini, A., Bettuzzi, M., Casali, F., Mancini, L.Detecting microdiamonds in kimberlite drill hole cores by computed tomography.International Journal of Mineral Processing, 16p.TechnologyMineral processing - microdiamonds
DS1999-0297
1999
SantosHartmann, L.A., Leite, J.A.D., McNaughton, N.J., SantosDeepest exposed crust of Brasil- SHRIMP established three eventsGeology, Vol. 27, No. 10, Oct. pp. 947-50.Brazil, Rio Grande do SulGeochronology, Shield
DS201112-0256
2011
SantosDe Oliveira Cordeiro, Brod, Palmieri, Gouveia de Oliveira, Soares Rocha Barbosa, Santos, Gaspar, AssisThe Catalao I niobium deposit, central Brazil: resources, geology and pyrochlore chemistry.Ore Geology Reviews, Vol. 41, pp. 112-121.South America, BrazilCarbonatite
DS200412-1966
2004
Santos, A.P.Tassinari, C.C.G., Munha, J.M.U., Teixeira, W., Palacios, T., Nutman, A.P., Santos, A.P., Calado, B.O.The Imataca Complex, NW Amazonian Craton, Venezuela: crustal evolution and integration of geochronological and petrological coolEpisodes, March pp. 3-12.South America, VenezuelaMetamorphism, Archean, tectonics, not specific to diamo
DS1996-0490
1996
Santos, J.Gaudette, H.E., Olezewski, W.J., Santos, J.Geochronology of Precambrian rocks from the northern part of the GuianaShield, State of RoraimaJournal of South American Earth Sciences, Vol. 9, No. 3/4, pp. 183-196BrazilGeochronology, Guiana Shield
DS2002-1399
2002
Santos, J.F.Santos, J.F., Scharer, U., Ibarguchi, J.I.G., GirardeauGenesis of pyroxenite rich peridotite at Cabo Ortegal : geochemical and Pb Sr Nd isotope data.Journal of Petrology, Vol. 43, No. 1, pp. 17-44.SpainPyroxenite, lead, strontium, neodynium, Petrology
DS1930-0080
1931
Santos, J.F. DOS.Santos, J.F. DOS.Le Diamant Au BresilParis: Les Belles Lettres, 289P. XEROX.BrazilKimberlite, Kimberley, Janlib, History
DS200512-0406
2004
Santos, J.O.Hartmann, L.A., Santos, J.O.Early Paleoproterozoic 2.5-2.0 Ga tectonic evolution of South America.Geological Society of America Annual Meeting ABSTRACTS, Nov. 7-10, Paper 142-5, Vol. 36, 5, p. 339.South America, Brazil, Venezuela, Guyana, French Guiana, UruguayTectonics
DS1987-0576
1987
Santos, L.Pereira, E., Santos, L.Long lived red luminesence in diamondJournal of Luminescence, Vol. 38, No. 10*-6, Dec. 1, pp. 181-183GlobalBlank
DS1988-0539
1988
Santos, L.Pereira, E., Santos, L.Brown diamonds - long lived visible luminescing centersJournal of Luminesc, Vol. 40, No. 1, February pp. 139-140GlobalBlank
DS201212-0124
2012
Santos, M.N.Chemale, F., Dussin, I.A., Alkmim, F.F., Martins, M.S., Queiroga, G., Armstrong, R., Santos, M.N.Unravelling a Proterozoic basin history through detrital zircon geochronology: the case of the Esponhaco Supergroup, Minas Gerais, Brazil.Gondwana Research, Vol. 22, 1, pp. 200-206.South America, Brazil, Minas GeraisSan Francisco Congo paleocraton, diamond bearing sequences
DS1989-0334
1989
Santos, R.A.Davison, I., Santos, R.A.Tectonic evolution of the Sergipano fold belt, northeastBrasil, during the Brasiliano OrogenyPrecambrian Research, Vol. 45, No. 4, December pp. 319-342BrazilTectonics, Brasiliano Orogeny
DS201602-0222
2016
Santos, R.P.Z. dos.Mantovani, M.S.M., Louro, V.H.A., Ribeiro, V.B., Requejo, H.S., Santos, R.P.Z. dos.Geophysical analysis of Catalano 1 alkaline carbonatite complex in Goias, Brazil.Geophysical Prospecting, Vol. 64, 1, pp. 216-227.South America, BrazilDeposit - Catalano 1
DS1995-1657
1995
Santos, R.V.Santos, R.V., Clayton, R.N.Variations of oxygen and carbon isotopes in carbonatites : a study of Brazilian alkaline complexes.Geochimica et Cosmochimica Acta ., Vol. 59, No. 7, pp. 1339-1352.BrazilCarbonatite -Alkaline rocks, Geochronology
DS1995-1658
1995
Santos, R.V.Santos, R.V., Clayton, R.N.The carbonate content in high temperature apatite: an analytical method applied Jacupiranga alkaline complexAmerican Mineralogist, Vol. 80, No. 3-4, March-Apr pp. 336-344.BrazilCarbonatite, Deposit - Jacupiranga
DS200812-0243
2008
Santos, R.V.Cordiero, P.F.O., Brod, J.A., Santos, R.V.Oxygen and carbon isotopes and carbonate chemistry in phoscorites from the Catalao I complex - implications for phosphate iron oxide magmas.9IKC.com, 3p. extended abstractSouth America, BrazilCarbonatite
DS201212-0053
2012
Santos, R.V.Barbosa, E.S.R., Brod, J.A., Junqueira-Brod, T.C., Cordeiro, P.F.O., Santos, R.V., Dantas, E.L.Phoscorites from the Salitre alkaline complex, Brazil: origin and petrogenetic implications.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractSouth America, BrazilDeposit - Salitre
DS201212-0054
2012
Santos, R.V.Barbosa, E.S.R., Brod, J.A., Junqueira-Brod, T.C., Cordeiro, P.F.O.,Dantas, E.L., Santos, R.V.Mineralogy and petrology of the Salitre 1 phoscorite carbonatite alkaline compelx, Brazil.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractSouth America, BrazilDeposit - Slitre 1
DS201212-0139
2012
Santos, R.V.Dalla-Costa, M.M., Santos, R.V., Araujo, D.P., Gaspar, J.C.Occurrence of garnets with eclogitic and lherzolitic compositions in garnet lherzolite xenolith from the Canastra-01 kimberlite pipe, Brazil.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractSouth America, BrazilDeposit - Canastra-01
DS201312-0319
2013
Santos, R.V.Gomide, C.S., Brod, J.A., Junqueira-Brod, T.C., Buhn, B.M., Santos, R.V., Barbosa, E.S.R., Cordeiro, P.F.O., Palmieri, M., Grasso, C.B., Torres, M.G.Sufur isotopes from Brazilian alkaline carbonatite complexes.Chemical Geology, Vol. 341, pp. 38-49.South America, BrazilDeposit - Tapira, Salitre, Serra Negra, Catalao, Jacupiringa
DS201901-0072
2018
Santos, S.S.M.Santos, S.S.M., Marcondes, M.L., Justo, J.F., Assali, L.V.C.Stability of calcium and magnesium carbonates at Earth's lower mantle thermodynamic conditions.Earth and Planetary Science Letters, Vol. 506, pp. 1-7.Mantlegeodynamics

Abstract: We present a theoretical investigation, based on ab initio calculations and the quasi-harmonic approximation, on the stability properties of magnesium (MgCO3) and calcium (CaCO3) carbonates at high temperatures and pressures. The results indicate that those carbonates should be stable in the Earth's lower mantle, instead of dissociating into other minerals, in chemical environments with excess of SiO2, MgO, or MgSiO3. Therefore, considering the lower mantle chemical composition, consisting mostly of the MgSiO3 and MgO minerals, calcium and magnesium carbonates are the primary candidates as carbon hosts in that region. For the thermodynamic conditions of the mantle, the results also indicate that carbon should be primarily hosted on MgCO3, contrasting with what was found by other theoretical studies, which neglected temperature effects. Finally, the results indicate that carbon, in the form of free CO2, is unlikely in the lower mantle.
DS202002-0217
2019
Santos Santiago, J.Santos Santiago, J., da Silva Souza, V., Dantas, E.L., de Oliveira. C.G.Ediacaran emerald mineralization in northeastern Brazil: the case of the Fazenda Bonfim deposit.Brazil Journal of Geology ( www.scielo.br) ENG, 14p. PdfSouth America, Brazildeposit - Fazenda Bonfim

Abstract: The Fazenda Bonfim emerald deposit lies within the Seridó Belt. It is a classic example of deposit formed through metasomatic interactions between Be-rich granite intrusions and Cr(± V)-rich mafic-ultramafic rocks. The setting of the emerald mineralization was built under strong strike-slip dynamics, which produced serpentinization and talcification of mafic-ultramafic host-rocks, and was followed by syn-kinematic emplacement of Be-rich albite granite, favoring hydrothermal/metasomatic processes. The structural control and lithological-contrast were fundamental to the fluid flow and the best ore-shoot geometry, developed in the S-foliation intra-plane at the contact zone (phlogopite hornfels) between mafic-ultramafic rocks and the albite granite. Subsequently, an albitization process, linked to the final-stage of magmatic crystallization, led to an overall mineralogical and chemical change of the albite granite. 207U-235Pb data revealed inheritance ages from Archean to Neoproterozoic and a crystallization age of 561 ± 4 Ma for albite granite. However, 40Ar/39Ar data revealed plateau age of 553 ± 4 Ma for phlogopite hornfels, interpreted as the closure time for the metasomatic event responsible for the nucleation and growth of emerald crystals. The short interval of time between U-Pb and Ar-Ar data indicates an intense, but not protracted, metasomatic history, probably due to low volume of intrusive magma.
DS201506-0300
2015
SantoshWu, Xiao, Xu, Santosh, Li, Huang, Hou.Geochronology and geochemistry of felsic xenoliths in lamprophyre dikes from the southeastern margin of the North Chin a Craton: implications for the interleaving of the Dabie Sulu orogenic crust.International Geology Review, Vol. 57, 9-10, pp. 1305-1325.ChinaDabie Sulu
DS1984-0541
1984
Santosh, M.Nair, N.G.K., Santosh, M., Thampi, P.K.Alkali Granite=syenite-carbonatite Association in Munnar, Kerala, India; Implications for Rifting, Alkaline Magmatism And Liquid Immiscibility.Proceedings INDIAN Academy of Science EARTH PLANET. SCIENCES, Vol. 93, No. 2, PP. 149-158.IndiaGeotectonics
DS1984-0542
1984
Santosh, M.Nair, N.G.K., Santosh, M., Thampi, P.K.Alkalic Granite Syenite Carbonatite Association in Munnar, kerala India: Implications for Rifting, Alkaline Magmatism And Liquid Immiscibility.Proceedings INDIAN Academy of Science, Vol. 93, No. 2, JULY PP. 149-158.India, KeralaCarbonatite
DS1987-0647
1987
Santosh, M.Santosh, M., Thampi, P.K., Iyer, S.S., Vasconsellos, M.B.A.Rare earth element geochemistry of the Munnar carbonatite,centralKeralaJournal of Geo. Soc. India, Vol. 29, March pp. 335-343IndiaRare earths, Carbonatite
DS1989-1336
1989
Santosh, M.Santosh, M.Alkaline plutons, decompression granulites and late Proterozoic CO2 influxin Kerala South IndiaGeological Society of India, Memoir, Editor C. LeelanandaM., No. 15, pp. 177-185IndiaAlkaline rocks, Granulites
DS1989-1337
1989
Santosh, M.Santosh, M., Iyer, S.S., Vasconcellos, M.B.A., Enzweiler, J.Late Precambrian alkaline plutons in southwest India:geochronologic and rare earth element constraints on Pan-African magmatismLithos, Vol. 24, pp. 65-79IndiaAlkaline plutons, alkaline rocks, Pan African magmatism, Rare earths
DS1994-0722
1994
Santosh, M.Harris, N.B.W., Santosh, M., Taylor, P.N.Crustal evolution in South India: constraints from neodymium isotopesJournal of Geology, Vol. 102, pp. 139-50.India, South IndiaTectonics, Karnataka Craton
DS1996-0606
1996
Santosh, M.Harris, N.B.W., Bartlett, J.M., Santosh, M.Neodymium isotope constraints on the tectonic evolution of East GondwanaJournal of Southeast Asian Sciences, Vol. 14, No. 3-4, pp. 119-125India, Sri Lanka, Madagascar, East Africa, GondwanaGeochronology, Tectonics
DS2000-0388
2000
Santosh, M.Hari, K.R., Kumar, M.S., Santosh, M., Rai, S.K.Melt inclusions in olivine and pyroxene phenocrysts from lamprophyres of Chhaktalao area.Journal of Asian Earth Science, Vol. 18, No.2, Apr. pp. 155-61.India, Madhya PradeshLamprophyres
DS200412-1722
2004
Santosh, M.Sajeev, K., Osani, Y., Santosh, M.Ultrahigh temperature metamorphism followed by two stage decompression of garnet orthopyroxene sillimanite granulites from GanguContributions to Mineralogy and Petrology, Vol. 148, 1, pp. 29-46.IndiaUHP
DS200412-2185
2003
Santosh, M.Yoshida, M., Jacobs, J., Santosh, M., Rajesh, H.M.Role of Pan African events in the Circum East Antarctic Orogen of East Gondwana: a critical overview.Proterozoic East Gondwana: Supercontinent assembly and Breakup. Ed. Yoshida , Geological Society of London Spe, No. 206, pp. 57-76.AntarcticaPlume, tectonics
DS200612-1168
2006
Santosh, M.Rogers, J.J., Santosh, M.The Sino-Korean Craton and supercontinent history: problems and perspectives.Gondwana Research, Vol. 9, 1-2, pp. 21-23.AsiaCraton
DS200612-1204
2006
Santosh, M.Sajeev, K., Santosh, M.Extreme crustal metamorphism and crust mantle processes: an introduction.Lithos, in press availableMantleMetamorphism
DS200612-1222
2006
Santosh, M.Santosh, M., Sajeev, K., Li, J.H.Extreme crustal metamorphism during Columbia supercontinent assembly: evidence from North Chin a Craton.Gondwana Research, Vol. 10, 3-4, pp. 256-266.ChinaMetamorphism
DS200712-0589
2007
Santosh, M.Kusky, T., Li, J., Santosh, M.The Paleoproterozic North Hebei orogen: North Chin a craton's collisional suture with the Columbia supercontinent.Gondwana Research, Vol. 12, 1-2, August pp. 4-28.ChinaTectonics
DS200712-0590
2007
Santosh, M.Kusky, T., Li, J., Santosh, M.The Paleoproterozic North Hebei orogen: North Chin a craton's collisional suture with the Columbia supercontinent.Gondwana Research, Vol. 12, 1-2, August pp. 4-28.ChinaTectonics
DS200712-0691
2007
Santosh, M.Maruyama, S., Santosh, M., Zhao, D.Superplume, supercontinent, and post perovskite: mantle dynamics and anti-plate tectonics on the core mantle boundary.Gondwana Research, Vol. 11, 1-2, Jan. pp. 7-37.MantlePlume
DS200812-0486
2008
Santosh, M.Hou, G., Santosh, M., Qian, X., Lister, G.S., Li, J.Configuration of the Late Paleoproterozoic supercontinent Columbia: insights from radiating mafic dyke swarms.Gondwana Research, Vol. 14, pp. 395-409.Mantle, South America, ColombiaSupercontinents
DS200812-0717
2008
Santosh, M.Maruyama, S., Santosh, M.Models on snowball Earth and Cambrian explosion: a synopsis.Gondwana Research, Vol. 14, 1-2, August pp. 22-32.MantleSnowball
DS200812-0718
2008
Santosh, M.Maruyama, S., Santosh, M.Snowball Earth to Cambrian explosion.Gondwana Research, Vol. 14, 1-2, August pp. 1-4.MantleSnowball
DS200812-0961
2008
Santosh, M.Rio, S., Kon, Y., Sato, W., Maruyana, S., Santosh, M., Zhao, D.The Grenvillian and Pan African orogens: world's largest orogenies through geologic time, and their implications on the origin of superplume.Gondwana Research, Vol. 14, 1-2, August pp. 51-72.MantleOrogeny
DS200812-0966
2008
Santosh, M.Rogers, J.J.W., Santosh, M.Tectonics and surface effects of the supercontinent Columbia.Gondwana Research, in press, 8p.Gondwana, ColumbiaTectonics
DS200812-1004
2007
Santosh, M.Santosh, M., Omari, S.CO2 flushing: a plate tectonic perspective.Gondwana Research, Vol. 13, 1, pp. 45-85.MantlePlate Tectonics
DS200812-1005
2008
Santosh, M.Santosh, M., Omori, S.CO2 windows from mantle to atmosphere: models on ultrahigh temperature metamorphism and speculations on the link with melting of snowball Earth.Gondwana Research, Vol. 14, 1-2, August pp. 97-104.MantleMelting
DS200812-1006
2008
Santosh, M.Santosh, M., Tsunogae, T., Ohyama, H., Sato, K., Li, J.H., Liu, S.J.Carbonic metamorphism at ultrahigh temperatures: evidence from North Chin a Craton.Earth and Planetary Science Letters, Vol. 266, 1-2, pp. 149-165.ChinaUHP
DS200912-0361
2009
Santosh, M.Katsube, A., Hayasaka, Y., Santosh, M., Li, S., Terada, K.SHRIMP zircon U Pb ages of eclogite and orthogneiss from Sulu ultrahigh pressure zone in Yangkou area, eastern China.Gondwana Research, Vol. 15, 2, pp. 168-177.ChinaUHP
DS200912-0475
2009
Santosh, M.Maruyama, S., Hasegawa, A., Santosh, M., Kogiso, T., Omori, S., Nakamura, H., Kawai, K., Zhao, D.The dynamics of big mantle wedge, magma factory, and metamorphic-metasomatic factory in subduction zones.Gondwana Research, Vol. 16, 3-4, pp. 414-430.MantleSubduction
DS200912-0639
2009
Santosh, M.Rogers, J.W.J., Santosh, M.Tectonics and surface effects of the supercontinent Colombia.Gondwana Research, Vol. 15, 3-4, pp. 373-380.MantleTectonics
DS200912-0663
2009
Santosh, M.Santosh, M., Maruyama, S., Omori, S.A fluid factory in solid Earth.Lithosphere, Vol. 1, no. 1, pp. 29-33.MantleTectonics, plumes
DS200912-0664
2009
Santosh, M.Santosh, M., Maruyana, S., Yamamoto,S.The making and breaking od supercontinents: some speculations based on superplumes, super downwelling and the role of tectosphere.Gondwana Research, Vol. 15, 3-4, pp. 324-341.MantlePlume, hotspots
DS200912-0665
2009
Santosh, M.Santosh, M., Wan, Y., Liu, D., Chunyan, D., Li, J.Anatomy of zircons from an ultrahot orogen: the amalgamation of the North Chin a craton within the supercontinent Columbia.Journal of Geology, Vol. 117, pp. 429-443.ChinaCraton, geochronology
DS200912-0666
2009
Santosh, M.Sarava dos Santos, T.J., Garcia, M.M., Amarai, W.S., Caby, R., Wernick, E., Arthaud, M.H., Dantas, E.L., Santosh, M.Relics of eclogite facies assemblages in the Ceara central domain, NW Borborema Province, NE Brazil: implications for the assembly of West Gondwana.Gondwana Research, Vol. 15, 3-4, pp. 454-470.South America, BrazilTectonics
DS201012-0526
2010
Santosh, M.Naganjaneyulu, K., Santosh, M.The Cambrian collisional suture of Gondwana in southern India: a geophysical appraisal.Journal of Geodynamics, Vol. 50, 3-4, pp. 256-267.IndiaTectonics
DS201012-0608
2010
Santosh, M.Rajesh, V.J., Arai, S., Santosh, M., Tamura, A.LREE rich hibonite in ultrapotassic rocks in southern India.Lithos, Available in press formated 11p.IndiaAlkalic
DS201012-0657
2010
Santosh, M.Santosh, M.A synopsis of recent conceptual models on supercontinent tectonics in relation to mantle dynamics, life evolution and surface environment.Journal of Geodynamics, Vol. 50, 3-4, pp. 116-133.MantleCrustal evolution
DS201012-0658
2010
Santosh, M.Santosh, M., Kusky, T.Origin of paired high pressure ultrahigh temperature orogens: a ridge subduction and slab window model.Terra Nova, Vol. 22, 1, pp. 35-42.MantleSubduction, UHP
DS201012-0659
2010
Santosh, M.Santosh, M., Maruyama, S., Komiya, T., Yamamoto, S.Orogens in the evolving Earth: from surface continents to 'lost continents'.The evolving continents: understanding processes of continental growth, Geological Society of London, Vol. 338, pp. 77-106.MantleGeodynamics
DS201012-0660
2010
Santosh, M.Santosh, M., Zhao, D., Kusky, T.Mantle dynamics of the Paleoproterozoic North Chin a Craton: a perspective based on seismic tomography.Journal of Geodynamics, Vol. 49, 1, pp. 39-53.ChinaGeophysics - seismics
DS201112-0567
2011
Santosh, M.Lan, T-G., Fan, H-R., Santosh, M., Hu, F-F., Yang, Y-H, Liu, Y.Geochemistry and Sr Nd Pb Hf isotopes of the Mesozoic Dadian alkaline intrusive complex in the Sulu orogenic belt, eastern China: implications for crust mantle interaction.Chemical Geology, Vol. 285, 1-4, pp. 97-114.ChinaAlkalic
DS201112-0912
2011
Santosh, M.Santosh, M., Kusky, T., Wang, L.Supercontinent cycles, extreme metamorphic processes and changing fluid regimes.International Geology Review, Vol. 53, no. 11-12, pp. 1403-1423.MantleMetamorphism
DS201112-0913
2011
Santosh, M.Santosh, M., Kusky, T., Wang, L.Supercontinent cycles, extreme metamorphic processes, and changing fluid regimes.International Geology Review, Vol. 53, 11-12, pp. 1403-1423.GlobalGondwana
DS201112-1133
2011
Santosh, M.Yang, K-F, Fan, H-R., Santosh, M., Hu, F-F., Wang, K-Y.Mesoproterozoic carbonatitic magmatism in the Bayan Obo deposit, Inner Mongolia, North China: constraints for the mechanism of super accumulation of rare earth elements.Ore Geology Reviews, in press available 10p.ChinaCarbonatite, REE
DS201112-1134
2011
Santosh, M.Yang, K-F., Fan, H-R., Santosh, M., Hu, F-F., Wang, K-Y.Mesoproterozoic mafic and carbonatitic dykes from the northern margin of the North Chin a craton: implications for the fin al breakup of Columbia supercontinent.Tectonophysics, Vol. 498, pp. 1-10.ChinaCarbonatite, Bayan Obo
DS201112-1141
2011
Santosh, M.Yoshida, M., Santosh, M.Future supercontinent assembled in the northern hemisphere.Terra Nova, Vol. 23. 5, pp. 283-348.MantleConvection, density anomaly
DS201112-1142
2011
Santosh, M.Yoshida, M., Santosh, M.Supercontinents, mantle dynamics and plate tectonics: a perspective based on conceptual vs. numerical models.Earth Science Reviews, Vol. 105, 1-2, pp. 1-24.MantleGeodynamics
DS201112-1143
2011
Santosh, M.Yoshida, M., Santosh, M.Future supercontinent assembled in the northern hemisphere.Terra Nova, Vol. 23, 5, pp. 333-338.MantleGondwana
DS201112-1158
2011
Santosh, M.Zhai, M-G., Santosh, M.Tectonic models for the North Chin a craton. The early Precambrian odyssey of the North Chin a craton: a synoptic overview.Gondwana Research, Vol. 20, 1, pp. 6-25.ChinaTectonics
DS201212-0578
2012
Santosh, M.Ram Mohan, M., Singh, S.P., Santosh, M., Siddiqui, M.A., Balaram, V.TTG suite from the Bundelk hand Craton, Central India: geochemistry, petrogenesis and implications for Archean crustal evolution.Journal of Asian Earth Sciences, Vol. 58, pp. 38-50.IndiaTectonics
DS201212-0812
2012
Santosh, M.Zhang, H-F., Yang,Y-H., Santosh, M., Zhao, X-M., Ying, J-F., Xiao, Y.Evolution of the Archean and Paleoproterozoic lower crust beneath the Trans-North Chin a Orogen and the western block of the north Chin a craton.Gondwana Research, Vol. 22, 1, pp. 73-85.ChinaGeochronology, tectonics, cratons
DS201212-0815
2012
Santosh, M.Zhang, P.-F., Tang, Y-J., Hu, Y., Zhang, H-F., Su, B-X., Xiao, Y., Santosh, M.Review of melting experiments on carbonated eclogite and peridotite: insights into mantle metasomatism.International Geology Review, in press availableMantleMetasomatism
DS201212-0816
2012
Santosh, M.Zhang, P=F., Tang, Y-J., Hu, Y., Zhang, H-F., Su, B-X., Xiao, Y., Santosh, M.Review of melting experiments on carbonated eclogite and peridotite: insights into mantle metasomatism.International Geology Review, In press availableMantleMetasmatism
DS201312-0004
2013
Santosh, M.Abu-Alam, T.S., Santosh, M., Brown, M.,Stuwe, K.Gondwana collision.Mineralogy and Petrology, Vol. 107, pp. 631-634.MantleKenoraland
DS201312-0629
2014
Santosh, M.Nance, R.D., Murphy, J.B., Santosh, M.The supercontinent cycle: a retrospective essay.Gondwana Research, Vol. 25, 1, pp. 4-29.Gondwana, RodiniaEarth history
DS201312-0890
2012
Santosh, M.Su, B-X., Zhang, H-F., Ying, Y-J., Hu, Y., Santosh, M.Metasomatized lithospheric mantle beneath the western Qinling, central China: insight into carbonatite melts in the mantle.Journal of Geology, Vol. 120, 6, pp. 671-681.ChinaCarbonatite
DS201312-0997
2013
Santosh, M.Yoshida, M., Santosh, M.Mantle convection modeling of the the supercontinent cycle: introversion, extroversion or a combination?Geoscience Frontiers, in press availableMantleConvection
DS201312-1009
2013
Santosh, M.Zhang, C-L., Li, H-K., Santosh, M.Revisiting the tectonic evolution of South China: interaction between Rodinia superplume and plate subduction?Terra Nova, Vol. 25, 3, pp. 212-220.ChinaSubduction
DS201312-1010
2013
Santosh, M.Zhang, D., Zhang, Z., Santosh, M., Cheng, Z., He, H., Kang, J.Perovskite and baddeleyite from kimberlitic intrusions in the Tarim large igneous province signal the onset of an end Carboniferous mantle plume.Earth and Planetary Science Letters, Vol. 361, pp. 238-248.ChinaDeposit - Wajiltag
DS201412-0125
2014
Santosh, M.Cheng, Z., Zhang, Z., Santosh, M., Hou, T., Zhang, D.Carbonate and silicate rich globules in the kimberlitic rocks of northwestern Tarim large igneous province, NW China: evidence for carbonated mantle source.Journal of Asian Earth Sciences, Vol. 95, pp. 114-135.ChinaDeposit - Wajilitage
DS201504-0229
2015
Santosh, M.Wang, Y., Santosh, M., Lou, Z., Hao, J.Large igneous provinces linked to supercontinent assembly.Journal of Geodynamics, Vol. 85, pp. 1-10.GlobalGeotectonics
DS201508-0358
2015
Santosh, M.He, X-F., Santosh, M., Zhang, Z-M., Tsunogae, T., Chetty, T.R.K., Ram Moham, M., AnbazhaganShonkinites from Salem, southern India: implications for Cryogenian alkaline magmatism in rift related setting.Journal of Asian Earth Sciences, in press availableIndiaShonkinites
DS201508-0364
2015
Santosh, M.Li, H., Zhang, Z., Ernst, R., Lu, L., Santosh, M., Zhang, D., Cheng, Z.Giant radiating mafic dyke swarm of the Emeishan Large Igneous Province: identifying the mantle plume centre.Terra Nova, Vol. 27, 4, pp. 247-257.ChinaMantle plume
DS201511-1874
2015
Santosh, M.Saha, A., Manikyamba, C., Santosh, M., Ganguly, S., Khelen, A.C.Platinum Group Elements ( PGE) geochemistry of komatiites and boninites from Dharwar Craton, India: implications for mantle melting processes.Journal of Asian Earth Sciences, Vol. 105, pp. 300-319.IndiaBoninites

Abstract: High MgO volcanic rocks having elevated concentrations of Ni and Cr are potential hosts for platinum group elements (PGE) owing to their primitive mantle origin and eruption at high temperatures. Though their higher PGE abundance is economically significant in mineral exploration studies, their lower concentrations are also valuable geochemical tools to evaluate petrogenetic processes. In this paper an attempt has been made to evaluate the PGE geochemistry of high MgO volcanic rocks from two greenstone belts of western and eastern Dharwar Craton and to discuss different mantle processes operative at diverse geodynamic settings during the Neoarchean time. The Bababudan greenstone belt of western and Gadwal greenstone belt of eastern Dharwar Cratons are dominantly composed of high MgO volcanic rocks which, based on distinct geochemical characteristics, have been identified as komatiites and boninites respectively. The Bababudan komatiites are essentially composed of olivine and clinopyroxene with rare plagioclase tending towards komatiitic basalts. The Gadwal boninites contain clinopyroxene, recrystallized hornblende with minor orthopyroxene, plagioclase and sulphide minerals. The Bababudan komatiites are Al-undepleted type (Al2O3/TiO2 = 23-59) with distinctly high MgO (27.4-35.8 wt.%), Ni (509-1066 ppm) and Cr (136-3036 ppm) contents. These rocks have low ?PGE (9-42 ppb) contents with 0.2-2.4 ppb Iridium (Ir), 0.2-1.4 ppb Osmium (Os) and 0.4-4.4 ppb Ruthenium (Ru) among Iridium group PGE (IPGE); and 1.4-16.2 ppb Platinum (Pt), 2.8-19 ppb Palladium (Pd) and 0.2-9.8 ppb Rhodium (Rh) among Platinum group PGE (PPGE). The Gadwal boninites are high-Ca boninites with CaO/Al2O3 ratios varying between 0.8 and 1.0, with 12-24 wt.% MgO, 821-1168 ppm Ni and 2307-2765 ppm Cr. They show higher concentration of total PGE (82-207 ppb) with Pt concentration ranging from 13 to 19 ppb, Pd between 65 and 180 ppb and Rh in the range of 1.4-3 ppb compared to the Bababudan komatiites. Ir, Os and Ru concentrations range from 0.6 to 2.2 ppb, 0.2 to 0.6 ppb and 1.4 to 2.6 ppb respectively in IPGE. The PGE abundances in Bababudan komatiites were controlled by olivine fractionation whereas that in Gadwal boninites were influenced by fractionation of chromite and sulphides. The Al-undepleted Bababudan komatiites are characterized by low CaO/Al2O3, (Gd/Yb)N, (La/Yb)N, with positive Zr, Hf, Ti anomalies and high Cu/Pd, Pd/Ir ratios at low Pd concentrations suggesting the derivation of parent magma by high degrees (>30%) partial melting of mantle under anhydrous conditions at shallow depth with garnet as a residual phase in the mantle restite. The komatiites are geochemically analogous to Al-undepleted Munro type komatiites and their PGE compositions are consistent with Alexo and Gorgona komatiites. The S-undersaturated character of Bababudan komatiites is attributed to decompression and assimilation of lower crustal materials during magma ascent and emplacement. In contrast, the higher Al2O3/TiO2, lower (Gd/Yb)N, for Gadwal boninites in combination with negative Nb, Zr, Hf, Ti anomalies and lower Cu/Pd at relatively higher Pd/Ir and Pd concentrations reflect high degree melting of refractory mantle wedge under hydrous conditions in an intraoceanic subduction zone setting. Higher Pd/Ir ratios and S-undersaturation of these boninites conform to influx of fluids derived by dehydration of subducted slab resulting into high fluid pressure and metasomatism of mantle wedge.
DS201610-1873
2016
Santosh, M.Ishwar-Kumar, C., Santosh, M., Wilde, S.A., Tsunogae, T., Itaya, T., Windley, B., Sajeev, K.Mesoproterozoic suturing of Archean crustal blocks in western peninsula India: implications for India-Madagascar correlations.Lithos, Vol. 263, pp. 143-160.IndiaGeodynamics

Abstract: The Kumta and Mercara suture zones welding together Archean crustal blocks in western peninsular India offer critical insights into Precambrian continental juxtapositions and the crustal evolution of eastern Gondwana. Here we present the results from an integrated study of the structure, geology, petrology, mineral chemistry, metamorphic P-T conditions, zircon U-Pb ages and Lu-Hf isotopes of metasedimentary rocks from the two sutures. The dominant rocks in the Kumta suture are greenschist- to amphibolite-facies quartz-phengite schist, garnet-biotite schist, chlorite schist, fuchsite schist and marble. The textural relations, mineral chemistry and thermodynamic modelling of garnet-biotite schist from the Kumta suture indicate peak metamorphic P-T conditions of ca. 11 kbar at 790 °C, with detrital SHRIMP U-Pb zircon ages ranging from 3420 to 2547 Ma, ?Hf (t) values from ? 9.2 to 5.6, and TDMc model ages from 3747 to 2792 Ma. The K-Ar age of phengite from quartz-phengite schist is ca. 1326 Ma and that of biotite from garnet-biotite schist is ca. 1385 Ma, which are interpreted to broadly constrain the timing of metamorphism related to the suturing event. The Mercara suture contains amphibolite- to granulite-facies mylonitic quartzo-feldspathic gneiss, garnet-kyanite-sillimanite gneiss, garnet-biotite-kyanite-gedrite-cordierite gneiss, garnet-biotite-hornblende gneiss, calc-silicate granulite and metagabbro. The textural relations, mineral chemistry and thermodynamic modelling of garnet-biotite-kyanite-gedrite-cordierite gneiss from the Mercara suture indicate peak metamorphic P-T conditions of ca. 13 kbar at 825 °C, followed by isothermal decompression and cooling. For pelitic gneisses from the Mercara suture, LA-ICP-MS U-Pb zircon ages vary from 3249 to 3045 Ma, ?Hf (t) values range from ? 18.9 to 4.2, and TDMc model ages vary from 4094 to 3314 Ma. The lower intercept age of detrital zircons in the pelitic gneisses from the Mercara suture ranges from 1464 to 1106 Ma, indicating the approximate timing of a major lead-loss event, possibly corresponding to metamorphism, and is broadly coeval with events in the Kumta suture. Synthesis of the above results indicates that the Kumta and Mercara suture zones incorporated sediments from Palaeoarchean to Mesoproterozoic sources and underwent high-pressure metamorphism in the late Mesoproterozoic. The protolith sediments were derived from regions containing juvenile Palaeoarchean crust, together with detritus from the recycling of older continental crust. Integration of the above results with published data suggests that the Mesoproterozoic (1460-1100 Ma) Kumta and Mercara suture zones separate the Archean (3400-2500 Ma) Karwar-Coorg block and Dharwar Craton in western peninsular India. Based on regional structural and other geological data we interpret the Kumta and Mercara suture zones as extensions of the Betsimisaraka suture of eastern Madagascar into western India.
DS201709-1954
2017
Santosh, M.Armistead, S.E., Collins, A.S., Payne, J.L., Foden, J.D., De Waele, B., Shaji, E., Santosh, M.A re-evaluation of the Kumta Suture in western peninsular India and its extension into Madagascar,Journal of Asian Earth Sciences, in press available, 47p.India, Africa, Madagascartectonis

Abstract: It has long been recognised that Madagascar was contiguous with India until the Late Cretaceous. However, the timing and nature of the amalgamation of these two regions remain highly contentious as is the location of Madagascar against India in Gondwana. Here we address these issues with new U-Pb and Lu-Hf zircon data from five metasedimentary samples from the Karwar Block of India and new Lu-Hf data from eight previously dated igneous rocks from central Madagascar and the Antongil-Masora domains of eastern Madagascar. New U-Pb data from Karwar-region detrital zircon grains yield two dominant age peaks at c. 3100 Ma and c. 2500 Ma. The c. 3100 Ma population has relatively juvenile ?Hf(t) values that trend toward an evolved signature at c. 2500 Ma. The c. 2500 Ma population shows a wide range of ?Hf(t) values reflecting mixing of an evolved source with a juvenile source at that time. These data, and the new Lu-Hf data from Madagascar, are compared with our new compilation of over 7000 U-Pb and 1000 Lu-Hf analyses from Madagascar and India. We have used multidimensional scaling to assess similarities in these data in a statistically robust way. We propose that the Karwar Block of western peninsular India is an extension of the western Dharwar Craton and not part of the Antananarivo Domain of Madagascar as has been suggested in some models. Based on ?Hf(t) signatures we also suggest that India (and the Antongil-Masora domains of Madagascar) were palaeogeographically isolated from central Madagascar (the Antananarivo Domain) during the Palaeoproterozoic. This supports a model where central Madagascar and India amalgamated during the Neoproterozoic along the Betsimisaraka Suture.
DS201709-2031
2017
Santosh, M.Meert, J.G., Santosh, M.The Columbia supercontinent revisited.Gondwana Research, Vol. 50, pp. 67-83.Globalsupercontinent

Abstract: Just over 15 years ago, a proposal forwarded by Rogers and Santosh (2002) posited the existence of a pre-Rodinia supercontinent which they called Columbia. The conjecture invigorated research into the Paleo-Mesoproterozoic interval that was; in our opinion, inappropriately dubbed ‘the boring billion’. Given the wealth of new information about the supercontinent, this review paper takes a careful look at the paleomagnetic evidence that is used to reconstruct Columbia. Our contribution represents a status report and indicates that; despite the exponential increase in available data, knowledge of the assembly, duration and breakup history of the supercontinent are contentious. The commonality of ~ 1.7–2.1 Ga orogenic systems around the globe are indicative of major changes in paleogeography and growth of larger landmasses. There is continued discussion about the interconnectedness of those orogenic systems in a global picture. Arguments for Columbia posit a ~ 1500–1400 Ma age for maximum packing. Paleomagnetic data from many of the constituent cratons during the 1500–1400 Ma interval can be interpreted to support a large landmass, but the consistency of the proposal cannot be reliably demonstrated for earlier or later times. One of the more intriguing advances are the apparent long-lived connections between Laurentia, Siberia and Baltica that may have formed the core of both Columbia and Rodinia.
DS201710-2267
2017
Santosh, M.Spencer, C.J., Roberts, N.M.W., Santosh, M.Growth, destruction, and preservation of Earth's continental crust.Earth-Science Reviews, Vol. 172, pp. 87-106.Mantlegeodynamics

Abstract: From the scant Hadean records of the Jack Hills to Cenozoic supervolcanoes, the continental crust provides a synoptic view deep into Earth history. However, the information is fragmented, as large volumes of continental crust have been recycled back into the mantle by a variety of processes. The preserved crustal record is the balance between the volume of crust generated by magmatic processes and the volume destroyed through return to the mantle by tectonic erosion and lower crustal delamination. At present-day, the Earth has reached near-equilibrium between the amount of crust being generated and that being returned to the mantle at subduction zones. However, multiple lines of evidence support secular change in crustal processes through time, including magma compositions, mantle temperatures, and metamorphic gradients. Though a variety of isotopic proxies are used to estimate crustal growth through time, none of those currently utilized are able to quantify the volumes of crust recycled back into the mantle. This implies the estimates of preserved continental crust and growth curves derived therefrom represent only a minimum of total crustal growth. We posit that from the Neoarchean, the probable onset of modern-day style plate tectonics (i.e. steep subduction), there has been no net crustal growth (and perhaps even a net loss) of the continental crust. Deciphering changes from this equilibrium state through geologic time remains a continual pursuit of crustal evolution studies.
DS201712-2727
2018
Santosh, M.Santosh, M., Hari, K.R., He, X-F., Han, Y-S., Manu Prasanth, M.P.Oldest lamproites from Peninsular India track the onset of Paleoproterozoic plume induced rifting and the birth of Large Igneous Province.Gondwana Research, Vol. 55, pp. 1-20.Indialamproites - Nuapada

Abstract: Potassic and ultrapotassic magmatism from deep lithospheric sources in intra-cratonic settings can be the signal of subsequent voluminous mafic magmatism and the formation of Large Igneous Provinces (LIPs) triggered by mantle plumes. Here we report for the first time, precise zircon U-Pb age data from a suite of lamproites in the Bastar Craton of central India that mark the onset of Paleoproterozoic rifting and culminating in the formation of extensive mafic dyke swarms as the bar codes of one of the major LIP events during the Precambrian evolution of the Indian shield. The lamproites from the Nuapada field occur as dismembered dykes and are composed of phenocrysts and microphenocrysts of altered olivine together with microphenocrysts of phlogopite and magnetite within a groundmass of chlorite and calcite with accessory rutile, apatite and zircon. The rocks compositionally correspond to olivine phlogopite lamproite and phlogopite lamproite. Geochemical features of the lamproites correlate with their counterparts in Peninsular India and other similar suites elsewhere in the world related to rift settings, and also indicate OIB-like magma source. The associated syenite shows subduction-related features, possibly generated in a post-collisional setting. Magmatic zircon grains with high Th/U ratios in the syenite from the Nuapada lamproite form a coherent group with an upper intercept age of 2473 ± 8 Ma representing the timing of emplacement of the magma. Zircon grains in three lamproite samples yield four distinct age groups at ca. 2.4 Ga, 2.2 Ga, 2.0 Ga and 0.8 Ga. The 2.4 Ga group corresponds to xenocrysts entrained from the syenite whereas the 2.2 Ga group is considered to represent the timing of emplacement of the lamproites. The ca. 2.0 Ga zircon grains correlate with the major thermal imprint associated with mafic magmatism and dyke emplacement in southern Bastar and the adjacent Dharwar Cratons. A few young zircon grains in the syenite and lamproites show a range of early to middle Neoproterozoic ages from 879 to 651 Ma corresponding to younger thermal event(s) as also represented by granitic veins cutting across these rocks and extensive silicification. Zircon Lu-Hf isotope data suggest magma derivation from a refertilized Paleo-Mesoarchean sub-continental lithospheric mantle, or OIB-type sources. The differences in Hf-isotope composition among the zircon grains from different age groups indicate that the mantle sources of the lamproite are heterogeneous at the regional scale. A combination of the features from geochemical and zircon Hf isotope data is consistent with asthenosphere-lithosphere interaction during the lamproite magma evolution. The timing of lamproite emplacement in central India correlates with the global 2.2 Ga record of LIPs. We link the origin of the related mantle plume to the recycling of subducted slabs associated with the prolonged subduction-accretion history prior to the Neoarchean cratonization, as well as the thermal blanket effect of the Earth’s oldest supercontinent. Pulsating plumes and continued rifting generated voluminous dyke swarms across the Bastar and Dharwar Cratons, forming part of a major global rifting and LIP event.
DS201802-0262
2018
Santosh, M.Santosh, M., Hari, K.R., He, X-F., Han, Y-S., Manu Prasanth, M.P.Oldest lamproites from Peninsular India track the onset of Paleoproterozoic plume induced rifting and the birth of Large Igneous Province.Gondwana Research, Vol. 55, pp. 1-20.Indialamproites

Abstract: Potassic and ultrapotassic magmatism from deep lithospheric sources in intra-cratonic settings can be the signal of subsequent voluminous mafic magmatism and the formation of Large Igneous Provinces (LIPs) triggered by mantle plumes. Here we report for the first time, precise zircon U-Pb age data from a suite of lamproites in the Bastar Craton of central India that mark the onset of Paleoproterozoic rifting and culminating in the formation of extensive mafic dyke swarms as the bar codes of one of the major LIP events during the Precambrian evolution of the Indian shield. The lamproites from the Nuapada field occur as dismembered dykes and are composed of phenocrysts and microphenocrysts of altered olivine together with microphenocrysts of phlogopite and magnetite within a groundmass of chlorite and calcite with accessory rutile, apatite and zircon. The rocks compositionally correspond to olivine phlogopite lamproite and phlogopite lamproite. Geochemical features of the lamproites correlate with their counterparts in Peninsular India and other similar suites elsewhere in the world related to rift settings, and also indicate OIB-like magma source. The associated syenite shows subduction-related features, possibly generated in a post-collisional setting. Magmatic zircon grains with high Th/U ratios in the syenite from the Nuapada lamproite form a coherent group with an upper intercept age of 2473 ± 8 Ma representing the timing of emplacement of the magma. Zircon grains in three lamproite samples yield four distinct age groups at ca. 2.4 Ga, 2.2 Ga, 2.0 Ga and 0.8 Ga. The 2.4 Ga group corresponds to xenocrysts entrained from the syenite whereas the 2.2 Ga group is considered to represent the timing of emplacement of the lamproites. The ca. 2.0 Ga zircon grains correlate with the major thermal imprint associated with mafic magmatism and dyke emplacement in southern Bastar and the adjacent Dharwar Cratons. A few young zircon grains in the syenite and lamproites show a range of early to middle Neoproterozoic ages from 879 to 651 Ma corresponding to younger thermal event(s) as also represented by granitic veins cutting across these rocks and extensive silicification. Zircon Lu-Hf isotope data suggest magma derivation from a refertilized Paleo-Mesoarchean sub-continental lithospheric mantle, or OIB-type sources. The differences in Hf-isotope composition among the zircon grains from different age groups indicate that the mantle sources of the lamproite are heterogeneous at the regional scale. A combination of the features from geochemical and zircon Hf isotope data is consistent with asthenosphere-lithosphere interaction during the lamproite magma evolution. The timing of lamproite emplacement in central India correlates with the global 2.2 Ga record of LIPs. We link the origin of the related mantle plume to the recycling of subducted slabs associated with the prolonged subduction-accretion history prior to the Neoarchean cratonization, as well as the thermal blanket effect of the Earth's oldest supercontinent. Pulsating plumes and continued rifting generated voluminous dyke swarms across the Bastar and Dharwar Cratons, forming part of a major global rifting and LIP event.
DS201806-1219
2018
Santosh, M.Dai, L., Li, S., Li, Z-H., Somerville, I., Santosh, M.Dynamics of exhumation and deformation of HP-UHP orogens in double subduction collision systems: numerical modeling and implications for the Western Dabie Orogen.Earth Science Reviews, Vol. 182, pp. 68-84.ChinaUHP

Abstract: The dynamics of formation and exhumation of high-pressure (HP) and ultra-high pressure (UHP) metamorphic orogens in double subduction-collision zones remain enigmatic. Here we employ two-dimensional thermo-mechanical numerical models to gain insights on the exhumation of HP-UHP metamorphic rocks, as well as their deformation during the collision of a micro-continent with pro- and retro-continental margins along two subduction zones. A three-stage collisional process with different convergence velocities is tested. In the initial collisional stage, a fold-and-thrust belt and locally rootless superimposed folds are developed in the micro-continent and subduction channel, respectively. In the second (exhumation) stage of HP-UHP rocks, a faster convergence model results in upwelling of the asthenosphere, which further leads to a detachment between the crust and lithospheric mantle of the micro-continent. A slower convergence model results in rapid exhumation of HP-UHP rocks along the north subduction channel and a typical piggy-back thrusting structure in the micro-continent. A non-convergence model produces a slab tear-off, leading to the rebound of residual lithosphere of the micro-continent. In the third and final stage, a series of back and ramp thrusts are formed in the micro-continent with the pro-continent re-subducted. Based on an analogy of our numerical results with the Western Dabie Orogen (WDO), we suggest that: (1) slab tear-off results in a rebound of residual lithosphere, which controls the two-stage syn-collisional exhumation process of HP-UHP rocks in the WDO; and (2) in contrast to the single subduction-collision system, the exhumation range of the partially molten rocks with lower viscosity and density is restricted to a specific region of the micro-continent by the Mianlue and Shangdan subduction zones, which generated the complex deformation features in the WDO.
DS201806-1229
2018
Santosh, M.Jayananda, M., Santosh, M., Aadhiseshan, K.R.Formation of Archean (3600-2500 Ma) continental crust in the Dharwar craton, southern India.Earth Science Reviews, Vol. 181, pp. 12-42.Indiageodynamics

Abstract: The generation, preservation and destruction of continental crust on Earth is of wide interest in understanding the formation of continents, cratons and supercontinents as well as related mineral deposits. In this contribution, we integrate the available field, petrographic, geochronologic, elemental Nd-Hf-Pb isotope data for greenstones, TTG gneisses, sanukitoids and anatectic granites from the Dharwar Craton (southern India). This review allows us to evaluate the accretionary processes of juvenile crust, mechanisms of continental growth, and secular evolution of geodynamic processes through the 3600-2500?Ma window, hence providing important insights into building of continents in the Early Earth. The Dharwar Craton formed by assembly of micro-blocks with independent thermal records and accretionary histories. The craton can be divided into three crustal blocks (western, central and eastern) separated by major shear zones. The western block contains some of the oldest basement rocks with two generations of volcano-sedimentary greenstone sequences and discrete potassic plutons whereas the central block consist of older migmatitic TTGs, abundant younger transitional TTGs, remnants of ancient high grade supracrustal rocks, linear volcanic-dominated greenstone belts, voluminous calc-alkaline granitoids of sanukitoid affinity and anatectic granites. In contrast, the eastern block comprises younger transitional TTGs, abundant diatexites, thin volcanic-sedimentary greenstone belts and calc-alkaline plutons. Published geochronologic data show five major periods of felsic crust formation at ca. 3450-3300?Ma, 3230-3150?Ma, 3000-2960?Ma, 2700-2600?Ma, and 2560-2520?Ma which are sub-contemporaneous with the episodes of greenstone volcanism. U-Pb ages of inherited zircons in TTGs, as well as detrital zircons together with Nd-Pb-Hf isotope data, reveal continental records of 3800-3600?Ma. The U-Pb zircon data suggest at least four major reworking events during ca. 3200?Ma, 3000?Ma, 2620-2600?Ma, and 2530-2500?Ma corresponding to lower crustal melting and spatially linked high grade metamorphic events. The TTGs are sub-divided into the older (3450-3000?Ma) TTGs and the younger (2700-2600?Ma) transitional TTGs. The older TTGs can be further sub-divided into low-Al and high-Al groups. Elemental and isotopic data suggest that the low-Al type formed by melting of oceanic island arc crust within plagioclase stability field. In contrast, the elemental and isotopic features for the high-Al group suggest derivation of their magmatic precursor by melting of oceanic arc crust at deeper levels (55-65?km) with variable garnet and ilmenite in residue. The transitional TTGs likely formed by melting of composite sources involving both enriched oceanic arc crust and sub-arc mantle with minor contamination of ancient crustal components. The geochemical and isotopic compositions of granitoids with sanukitoid affinity suggest derivation from enriched mantle reservoirs. Finally, anatectic granites were produced by reworking of crustal sources with different histories. In the light of the data reviewed in this contribution, we propose the following scenario for the tectonic evolution of the Dharwar Craton. During 3450-3000?Ma, TTGs sources (oceanic arc crust) formed by melting of down going slabs and subsequent melting of such newly formed crust at different depths resulted in TTG magmas. On the contrary, by 2700?Ma the depth of slab melting increased. Melting of slab at greater depth alongside the detritus results in enriched melts partly modified the overlying mantle wedge. Subsequent melting of such newly formed enriched oceanic arc crust and surrounding arc-mantle generated the magmatic precursor to transitional TTGs. Finally at ca. 2600-2560?Ma, eventual breakoff of down going slab caused mantle upwelling which induced low degree (10-15%) melting of overlying enriched mantle at different depths, thereby, generating the sanukitoid magmas which upon emplacement into the crust caused high temperature metamorphism, reworking and final cratonization.
DS201903-0515
2019
Santosh, M.Han, Y-S., Santosh, M., Ganguly, S., Li, S-S.Evolution of a Mesoarchean suprasubduction zone mantle wedge in the Dharwar Craton, southern India: evidence from petrology, geochemistry, zircon U-Pb geochronology, and Lu-Hf isotopes.Geological Journal, doi:10.1002/gj.3440Indiacraton

Abstract: Petrological, geochemical, and zircon U-Pb geochronological features of Archean ultramafic-mafic complexes formed in subduction?related settings provide significant insights into mantle source and geodynamic processes associated with subduction-accretion?collision events in the early Earth. Here, we investigate a suite of serpentinized dunite, dunite, pyroxenite, and clinopyroxenite from an ultramafic complex along the collisional suture between the Western Dharwar Craton (WDC) and the Central Dharwar Craton (CDC) in southern India. We present petrology, mineral chemistry, zircon U-Pb geochronology, rare earth element (REE), Lu-Hf isotopes, and whole?rock geochemistry including major, trace element, and platinum?group element (PGE) data with a view to investigate the magmatic and metasomatic processes in the subduction zone. Mineral chemistry data from chromite associated with the serpentinised ultramafic rocks show distinct characteristics of arc?related melt. Zircon U-Pb data from the ultramafic suite define different age populations, with the oldest ages at 2.9 Ga, and the dominant age population showing a range of 2.8-2.6 Ga. The early Paleoproterozoic (ca. 2.4 Ga) metamorphic age is considered to mark the timing of collision of the two WDC and CDC. Zircon REE patterns suggest the involvement continental crust components in the magma source. Zircon Lu-Hf analysis yields both positive and negative ?Hf(t) values from ?3.9 to 1.5 with Hf?depleted model ages (TDM) of 3,041-3,366 Ma for serpentinised dunite and ?0.2-2.0 and 2,833-2,995 Ma for pyroxenite, suggesting that the magma was sourced from depleted mantle and was contaminated with the ancient continental crust. Geochemical data show low MgO/SiO2 values and elevated Al2O3/TiO2 ratios, implying subduction?related setting. The serpentinized dunites and dunites show mild LREE enrichment over HREE, with relatively higher abundance of LILE (Ba, Sr) and depletion in HFSE (Nb, Zr), suggesting fluid-rock interaction, melt impregnation, and refertilization processes. The PGE data suggest olivine, chromite, and sulphide fractionations associated with subduction processes. Our study on the Mesoarchean to Neoarchean ultramafic complex provides important insights to reconstruct the history of the crust-mantle interaction in an Archean suprasubduction zone mantle wedge.
DS201903-0522
2019
Santosh, M.Johnson, T.E., Kirkland, C.L., Gardiner, C.L., Gardiner, N.J., Brown, M., Smithies, R.H., Santosh, M.Secular change in TTG compositions: implications for the evolution of Archean geodynamics.Earth and Planetary Science Letters, Vol. 505, pp. 65-75.Mantlegeothermometry

Abstract: It is estimated that around three quarters of Earth's first generation continental crust had been produced by the end of the Archaean Eon, 2.5 billion years ago. This ancient continental crust is mostly composed of variably deformed and metamorphosed magmatic rocks of the tonalite-trondhjemite-granodiorite (TTG) suite that formed by partial melting of hydrated mafic rocks. However, the geodynamic regime under which TTG magmas formed is a matter of ongoing debate. Using a filtered global geochemical dataset of 563 samples with ages ranging from the Eoarchaean to Neoarchaean (4.0-2.5 Ga), we interrogate the bulk rock major oxide and trace element composition of TTGs to assess evidence for secular change. Despite a high degree of scatter in the data, the concentrations or ratios of several key major oxides and trace elements show statistically significant trends that indicate maxima, minima and/or transitions in the interval 3.3-3.0 Ga. Importantly, a change point analysis of K2O/Na2O, Sr/Y and LaN/YbN demonstrates a statistically significant (>99% confidence) change during this 300 Ma period. These shifts may be linked to a fundamental change in geodynamic regime around the peak in upper mantle temperatures from one dominated by non-uniformitarian, deformable stagnant lid processes to another dominated by the emergence of global mobile lid or plate tectonic processes by the end of the Archaean. A notable change is also evident at 2.8-2.7 Ga that coincides with a major jump in the rate of survival of metamorphic rocks with contrasting thermal gradients, which may relate to the emergence of more potassic continental arc magmas and an increased preservation potential during collisional orogenesis. In many cases, the chemical composition of TTGs shows an increasing spread through the Archaean, reflecting the irreversible differentiation of the lithosphere.
DS201908-1811
2019
Santosh, M.Santosh, M., Maruyama, S., Sawaki, Y., Meert, J.G.The Cambrian explosion: plume-driven birth of the second ecosystem on Earth. Gondwana Research, doi.org/10.1016 /j.gr.2013.03.013 21p. PdfAfrica, Mozambiquetectonics

Abstract: The birth of modern life on Earth can be linked to the adequate supply of nutrients into the oceans. In this paper, we evaluate the relative supply of nutrients into the ocean. These nutrients entered the ocean through myriad passageways, but primarily through accelerated erosion due to uplift. In the ‘second ecosystem’, uplift is associated with plume-generation during the breakup of the Rodinia supercontinent. Although the evidence is somewhat cryptic, it appears that the second ecosystem included the demospongia back into the Cryogenian (~ 750 Ma). During the Ediacaran-Cambrian interval, convergent margin magmatism, arc volcanism and the closure of ocean basins provided a second pulse of nutrient delivery into the marine environment. A major radiation of life forms begins around 580 Ma and is represented by the diverse and somewhat enigmatic Ediacaran fauna followed by the Cambrian Explosion of modern phyla during the 540-520 Ma interval. Tectonically, the Ediacaran-Cambrian time interval is dominated by the formation of ultra-high pressure (UHP), high pressure (HP) and ultra-high temperature (UHT) orogenic belts during Gondwana orogenesis. Erosion of this extensive mountainous region delivered vast nutrients into the ocean and enhanced the explosiveness of the Cambrian radiation. The timing of final collisional orogeny and construction of the mountain belts in many of the Gondwana-forming orogens, particularly some of those in the central and eastern belts, post-date the first appearance of modern life forms. We therefore postulate that a more effective nutrient supply for the Cambrian radiation was facilitated by plume-driven uplift of TTG crust, subsequent rifting, and subduction-related nutrient systems prior to the assembly of Gondwana. In the outlined scenario, we propose that the birth of the ‘second ecosystem’ on our planet is plume-driven.
DS202001-0037
2020
Santosh, M.Santosh, M., Tsunogae, T., Yang, C-X., Han, T-S., Hari, K.R., Prasanth, M.P.M., Uthup, S.The Bastar craton, central India: a window to Archean - Paleoproterozic crustal evolution.Gondwana Research, Vol. 79, pp. 157-184.Indiacraton

Abstract: The Bastar craton in central India, surrounded by cratonic blocks and Paleoproterozoic to Neoproterozoic orogenic belts, is a window to investigate the Archean-Paleoproterozoic crustal evolution and tectonic processes. Here we propose a new tectonic classification of the craton into the Western Bastar Craton (WBC), Eastern Bastar Craton (EBC), and the intervening Central Bastar Orogen (CBO). We present petrologic, geochemical and zircon U-Pb, REE and Lu-Hf data from a suite of rocks from the CBO and along the eastern margin of the WBC Including: (1) volcanic successions comprising meta-andesite and fine-grained amphibolite, representing arc-related volcanics along a convergent margin; (2) ferruginous sandstone, in association with rhyolite, representing a volcano-sedimentary succession, deposited in an active trench; and (3) metamorphosed mafic-ultramafic suite including gabbro, pyroxenite and dunite invaded by trondhjemite representing the section of sub-arc mantle and arc root adjacent to a long-lasting subduction system. Petrologic studies indicate that the mafic-ultramafic suite crystallized from an island arc tholeiitic parental magma in a suprasubduction zone environment. The chondrite-normalized and primitive mantle normalized diagrams of the mafic and ultramafic rocks suggest derivation from MORB magma. The mixed characters from N-MORB to E-MORB of the studied samples are consistent with subduction modification of a MORB related magma, involving partial melting of the metasomatized mantle wedge. Our zircon U-Pb age data suggest that the cratonic nuclei was constructed as early as Paleoarchean. We present evidence for active subduction and arc magmatism through Mesoarchean to Neoarchean and early Paleoproterozoic, with the trench remaining open until at least 2.3?Ga. Two major crust building events are recognized in the Bastar craton: during Mesoarchean (recycled Paleoarchean subduction-related as well as juvenile/depleted mantle components) and Neoarchean (accretion of juvenile oceanic crust, arc magmatism including granite batholiths and related porphyry mineralization). The final cratonization occurred during latest Paleoproterozoic, followed by collisional assembly of the craton and its incorporation within the Peninsular Indian mosaic during Mesoproterozoic. In the global supercontinent context, the craton preserves the history of Ur, the earliest supercontinent, followed by the Paleo-Mesoproterozoic Columbia, as well as minor thermal imprints of the Neoproterozoic Rodinia and associated Grenvillian orogeny.
DS202003-0361
2020
Santosh, M.Santosh, M., Tsunogae, T., Yang, C-X., Han, Y-S., Hari, K.R., Manu Prasanth, M.P., Uthup, S.The Bastar craton, central India: a window to Archean - Paleoproterozoic crustal evolution.Gondwana Research, Vol. 79, pp. 157-184.Indiacraton

Abstract: The Bastar craton in central India, surrounded by cratonic blocks and Paleoproterozoic to Neoproterozoic orogenic belts, is a window to investigate the Archean-Paleoproterozoic crustal evolution and tectonic processes. Here we propose a new tectonic classification of the craton into the Western Bastar Craton (WBC), Eastern Bastar Craton (EBC), and the intervening Central Bastar Orogen (CBO). We present petrologic, geochemical and zircon U-Pb, REE and Lu-Hf data from a suite of rocks from the CBO and along the eastern margin of the WBC Including: (1) volcanic successions comprising meta-andesite and fine-grained amphibolite, representing arc-related volcanics along a convergent margin; (2) ferruginous sandstone, in association with rhyolite, representing a volcano-sedimentary succession, deposited in an active trench; and (3) metamorphosed mafic-ultramafic suite including gabbro, pyroxenite and dunite invaded by trondhjemite representing the section of sub-arc mantle and arc root adjacent to a long-lasting subduction system. Petrologic studies indicate that the mafic-ultramafic suite crystallized from an island arc tholeiitic parental magma in a suprasubduction zone environment. The chondrite-normalized and primitive mantle normalized diagrams of the mafic and ultramafic rocks suggest derivation from MORB magma. The mixed characters from N-MORB to E-MORB of the studied samples are consistent with subduction modification of a MORB related magma, involving partial melting of the metasomatized mantle wedge. Our zircon U-Pb age data suggest that the cratonic nuclei was constructed as early as Paleoarchean. We present evidence for active subduction and arc magmatism through Mesoarchean to Neoarchean and early Paleoproterozoic, with the trench remaining open until at least 2.3?Ga. Two major crust building events are recognized in the Bastar craton: during Mesoarchean (recycled Paleoarchean subduction-related as well as juvenile/depleted mantle components) and Neoarchean (accretion of juvenile oceanic crust, arc magmatism including granite batholiths and related porphyry mineralization). The final cratonization occurred during latest Paleoproterozoic, followed by collisional assembly of the craton and its incorporation within the Peninsular Indian mosaic during Mesoproterozoic. In the global supercontinent context, the craton preserves the history of Ur, the earliest supercontinent, followed by the Paleo-Mesoproterozoic Columbia, as well as minor thermal imprints of the Neoproterozoic Rodinia and associated Grenvillian orogeny.
DS202007-1168
2020
Santosh, M.Palin, R.M., Santosh, M., Cao, W., Li, S-S., Hernandez-Uribe, D.Secular change and the onset of plate tectonics on Earth.Earth Science Reviews, in press available 41p. PdfMantleplate tectonics

Abstract: The Earth as a planetary system has experienced significant change since its formation c. 4.54 Gyr ago. Some of these changes have been gradual, such as secular cooling of the mantle, and some have been abrupt, such as the rapid increase in free oxygen in the atmosphere at the Archean-Proterozoic transition. Many of these changes have directly affected tectonic processes on Earth and are manifest by temporal trends within the sedimentary, igneous, and metamorphic rock record. Indeed, the timing of global onset of mobile-lid (subduction-driven) plate tectonics on our planet remains one of the fundamental points of debate within the geosciences today, and constraining the age and cause of this transition has profound implications for understanding our own planet's long-term evolution, and that for other rocky bodies in our solar system. Interpretations based on various sources of evidence have led different authors to propose a very wide range of ages for the onset of subduction-driven tectonics, which span almost all of Earth history from the Hadean to the Neoproterozoic, with this uncertainty stemming from the varying reliability of different proxies. Here, we review evidence for paleo-subduction preserved within the geological record, with a focus on metamorphic rocks and the geodynamic information that can be derived from them. First, we describe the different types of tectonic/geodynamic regimes that may occur on Earth or any other silicate body, and then review different models for the thermal evolution of the Earth and the geodynamic conditions necessary for plate tectonics to stabilize on a rocky planet. The community's current understanding of the petrology and structure of Archean and Proterozoic oceanic and continental crust is then discussed in comparison with modern-day equivalents, including how and why they differ. We then summarize evidence for the operation of subduction through time, including petrological (metamorphic), tectonic, and geochemical/isotopic data, and the results of petrological and geodynamical modeling. The styles of metamorphism in the Archean are then examined and we discuss how the secular distribution of metamorphic rock types can inform the type of geodynamic regime that operated at any point in time. In conclusion, we argue that most independent observations from the geological record and results of lithospheric-scale geodynamic modeling support a global-scale initiation of plate tectonics no later than c. 3 Ga, just preceding the Archean-Proterozoic transition. Evidence for subduction in Early Archean terranes is likely accounted for by localized occurrences of plume-induced subduction initiation, although these did not develop into a stable, globally connected network of plate boundaries until later in Earth history. Finally, we provide a discussion of major unresolved questions related to this review's theme and provide suggested directions for future research.
DS202008-1381
2020
Santosh, M.Choudhary, B.R., Santosh, M., Ravi, S., Babu, EVSSKIndicator mineral ( spinel) from the Wajrakarur kimberlites, southern India: implications for diamond potential and prospectivity.Goldschmidt 2020, 1p. AbstractIndiadeposit - Wajraarur, Kalandurg

Abstract: P-5 and Kl-4 Mesoproterozoic (ca. 1110 Ma) kimberlites from the Wajrakarur and Kalyandurg clusters, Eastern Dharwar craton (EDC), southern India are intruded into the diamondiferous cratonic roots. The spinel compositions is straddling between magnesian ulvöspinel (Group-1 kimberlite) and titanomagnetite (Group-2 kimberlite), comparable with orangeite and lamproites. These Ti-rich minerals have orangeitic affinity, as in the Kaapvaal craton of South Africa, and reflect the high Ti-, high Ca- and the low Al-bearing nature of the parent magma (Group II kimberlites). Larger chrome spinel macrocrysts/xenocrysts show >500 ?m of size with distinctly high chromium (Cr2O3 up to 59.62 wt%), and TiO2-poor (<1.19 wt%). The high chromium spinel macrocrysts represent fragments of mantle xenocrysts and their composition falls within the diamond stability field. The groundmass spinel has been replaced by Ti- schorlomite. The schorlomite garnet represents solid solution of schorlomite -pyrope -almandine-grossular and Crrich schorlomite -pyrope -almandine- uvarovite solid solution. These associations recommend that the schorlomite formed through the replacement of spinel through interaction of late residual fluids/melts in the final stages of crystallization of the kimberlite magma and enrichment in Fe and Ti in schorlomite suggests the involvement of metasomatized sub-continental lithospheric mantle. Present study may have useful application in diamond prospectivity.
DS202009-1629
2020
Santosh, M.Groves, D.I., Santosh, M.Craton and thick lithosphere margins: the sites of giant mineral deposits and mineral provinces. Not specific to diamonds.Gondwana Research, in press available 28p. PdfGlobalgeodynamics
DS202011-2032
2020
Santosh, M.Cai, W-C., Zhang, Z-C., Zhu, J., Santosh, M., Pan, R-H.Genesis of high ni-olivine phenocrysts of the Dali picrites in the central Emeishan large igneous province.Geological Magazine, doi: 10.1017/ S0016756820001053 10p. Chinapicrites

Abstract: The Emeishan large igneous province (ELIP) in SW China is considered to be a typical mantle-plume-derived LIP. The picrites formed at relatively high temperatures in the ELIP, providing one of the important lines of argument for the role of mantle plume. Here we report trace-element data on olivine phenocrysts in the Dali picrites from the ELIP. The olivines are Ni-rich, and characterized by high (>1.4) 100×Mn/Fe value and low (<13) 10 000×Zn/Fe value, indicating a peridotite-dominated source. Since the olivine-melt Ni partition coefficient (KDNiol/melt) will decrease at high temperatures and pressures, the picrites derived from peridotite melting at high pressure, and that crystallized olivines at lower pressure, can generate high concentrations of Ni in olivine phenocrysts, excluding the necessity of a metasomatic pyroxenite contribution. Based on the Al-in-olivine thermometer, olivine crystallization temperature and mantle potential temperature (T P) were calculated at c. 1491°C and c. 1559°C, respectively. Our results are c. 200°C higher than that of the normal asthenospheric mantle, and are consistent with the role of a mantle thermal plume for the ELIP.
DS202011-2035
2020
Santosh, M.Choudhary, B.R., Santosh, M., Ravi, S., Babu, E.V.S.S.K.Spinel and Ti-rich schorlomite from the Wajrakarur kimberlites, southern India: implications for metasomatism, diamond potential and orangeite lineage.Ore Geology Reviews, Vol. 126, 103727, 19p. PdfIndiadeposit - Wajrakarur

Abstract: Kl-4 and P-5 mesoproterozoic kimberlite pipes along with several other well-known diamondiferous (ca. 1110 Ma) kimberlites in the Wajrakarur kimberlite field (WKF) intruded into the cratonic roots of Eastern Dharwar craton (EDC) in southern India. The groundmass minerals of the kimberlites exhibit inequigranular texture contain spinel, Ti-rich schorlomite garnet, two generations of olivine (macrocrysts and groundmass microphenocrysts), phlogopite, perovskite, clinopyroxene (diopside), ilmenite (low Mn) and rare apatite. We identified three distinct spinel associations in Kl-4 and P-5: (i) fine-grained (<50 ?m) microcrysts in the groundmass; (ii) resorbed euhedral atoll spinel, consisting of titanomagnetite (magnesian-ulvospinel-magnetite to titanian-chrome-magnetite) which is isolated from the rim of magnetite by spongy lagoon phase of schorlomite, and (iii) larger chrome spinel macrocrysts/xenocrysts (>500 ?m). The schorlomite garnet in both P-5 and Kl-4 represents solid solution of schorlomite-pyrope-almandine-grossular. Additionally, Kl-4 contains another Cr-rich schorlomite-pyrope-almandine-uvarovite solid solution. Macrocrystic spinel exhibits distinct composition of chromium (Cr2O3 up to 59.62 wt%), and poor in TiO2 (<1.19 wt%). The high chromium spinel macrocrysts from Kl-4 are confirmed to be fragments of mantle xenocrysts and their composition falls within the diamond stability field. Atoll-textured epitaxial mantled resorbed spinel associated with schorlomite suggests that they formed through the replacement of spinel possibly through interaction of late residual fluids/melts in the final stages of crystallization of the kimberlite magma. The significant enrichment of Fe and Ti in schorlomite suggests the involvement of metasomatized sub-continental lithospheric mantle. It is also inferred that spinel immiscibility played an important role in the metasomatic replacement. The Ti-rich minerals have orangeitic affinity, similar to those in the Kaapvaal craton of South Africa, and suggest the high Ti-, high Ca- and the low Al-bearing nature of the parent magma (Group II kimberlites). The groundmass tetraferriphlogopite is Al- and Ba-poor and spinel show compositions straddling between magnesian ulvöspinel (Group I kimberlite) and titanomagnetite (Group II kimberlite) comparable with orangeite and lamproites. The results presented in this study suggest that the P-5 and Kl-4 has orengeitic or lamproitic affinity. Our findings can be useful as an indicator mineral in diamond prospecting.
DS202012-2237
2020
Santosh, M.Palin, R.M., Santosh, M.Plate tectonics: what, where, why, and when?Gondwana Research, in proof available, 105p. Pdf 10.1016/j.gr.2020.11.001Globalplate tectonics
DS202108-1312
2021
Santosh, M.Vasanti, A., Singh, A.P., Kumar, N., Nageswara Rao, B., Satyakumar, A.V., Santosh, M.Crust-mantle structure and lithospheric destruction of the oldest craton in the Indian shield.Precambrian Research, Vol. 362, 16p. PdfIndiacraton

Abstract: The Singhbhum craton is among the five Archean cratons of Peninsular India that preserves some of the oldest continental nuclei. In this work, we present a new and complete Bouguer gravity map of this craton with insights into its deep crust-mantle structure, lithospheric thickness and density variations beneath this craton. The conspicuous presence of high-order residual gravity low anomalies, together with low estimated densities, suggests voluminous presence of Singhbhum granitic batholiths that built the dominant crustal architecture. The isolated residual gravity highs correspond to the mafic and ultramafic volcanic suites like, Dhanjori, Simlipal and Dalma, while the relatively low gravity anomalies observed over the western volcanic suites like Malangtoli, Jagannathpur and Ongarbira, indicate their relatively felsic nature. The estimated lithospheric thickness of about ~ 130 km below the granitic batholithic region, and about 112 km beneath the Precambrian volcanic terranes, together with low effective elastic thickness (Te,) of only about 31 km, suggest a thin and weak lithosphere. The craton witnessed extensive lithospheric destruction with the removal of nearly 100-150 km of the cratonic root. The decratonization may be linked to subduction during the Paleo-Mesoproterozoic period, together with mantle plumes at different times, suggesting a combined mechanical, thermal and chemical erosion of the cratonic keel.
DS202108-1313
2021
Santosh, M.Wang, C., Zhang, Z., Xie, Q., Cheng, Z., Kong, W., Liu, B., Santosh, M., Jin, S.Olivine from aillikites in the Tarim large igneous province as a window into mantle metasomatism and multi-stage magma evolution.American Mineralogist, Vol. 106, pp. 1064-1076.Chinametasomatism

Abstract: Aillikites are carbonate-rich ultramafic lamprophyres, and although they are volumetrically minor components of large igneous province (LIP), these rocks provide important clues to melting and meta-somatism in the deep mantle domain during the initial stages of LIPs. In this study, we investigate the Wajilitag “kimberlites” in the northwestern part of the Tarim LIP that we redefine as hypabyssal aillikites based on the following features: (1) micro-phenocrystic clinopyroxene and Ti-rich andradite garnet occurring in abundance in the carbonate-rich matrix; (2) Cr-spinel exhibiting typical Fe-Ti enrichment trend also known as titanomagnetite trend; and (3) olivine showing dominantly low Mg values (Fo < 90). To constrain the magma source and evolution, the major, minor, and trace element abundance in olivine grains from these rocks were analyzed using electron microprobe and laser ablation-inductively coupled plasma-mass spectrometry. Olivine in the aillikites occurs as two textural types: (1) groundmass olivines, as sub-rounded grains in matrix, and (2) macrocrysts, as euhedral-anhedral crystals in nodules. The groundmass olivines show varying Mg (Fo89-80) with high-Ni (1606-3418 ppm) and Mn (1424-2860 ppm) and low-Ca (571-896 ppm) contents. In contrast, the macrocrysts exhibit a restricted Fo range but a wide range in Ni and Mn. The former occurs as phenocrysts, whereas the latter are cognate cumulates that formed from earlier, evolved aillikite melt. The two olivine populations can be further divided into sub-groups, indicating a multi-stage crystallization history of the aillikite melt. The crystallization temperatures of groundmass olivines and macrocrysts in dunite nodules as computed from the spinel-olivine thermometers are 1005-1136 and 906-1041 °C, respectively. The coupled enrichment of Ca and Ti and lack of correlation between Ni and Sc and Co in the olivine grains suggest a carbonate-silicate metasomatized mantle source. Moreover, the high 100•Mn/Fe (average 1.67) at high Ni (up to 3418 ppm), overlapping with OIB olivine, and the 100•Ni/Mg (~1) of primitive Mg-Ni-rich groundmass olivines suggest a mixed source that involved phlogopite- and carbonate-rich metasomatic veins within mantle peridotite.
DS1996-0964
1996
Santosh, M/ et al.Miller, J.S., Santosh, M/ et al.A Pan- African thermal event in southern IndiaJournal of Southeast Asian Sciences, Vol. 14, No. 3-4, pp. 127-136IndiaGeochronology, Tectonics
DS200512-0934
2005
Santosj, M.Santosj, M., Tanaka, K., Yokoyama, K., Collins, A.S.Late Neoproterozoic Cambrian felsic magmatism along transcrustral shear zones in southern India: U Pb electron microprobe ages implications for amalagamtionGondwana Research, Vol. 8, 1, pp. 31-42.IndiaGeochronology, Gondwana supercontinent
DS201509-0403
2015
Santoul, J.Jessell, M., Santoul, J., Baratoux, L., Youbi, N., Ernst, R.E., Metelka, V., Miller, J., Perrouty, S.An updated map of West African mafic dykes.Journal of African Earth Sciences, in press availableAfrica, West AfricaGeophysics - magnetics

Abstract: Studies of mafic dyke swarms may simultaneously provide information on the mechanical, geochemical, geochronological and magnetic environments at the time of their formation. The mafic intrusive history of different cratons can also be potentially used to unravel their assembly into their current configuration. The identification and classification of dykes is a first step to all these studies. Fortunately, even in regions with poor outcrop, we can use the strong magnetic response of mafic dykes to identify and map their extent. In West Africa the first maps of mafic dyke distribution were made over 40 years ago, but there are still large areas where there are almost no published data. In this paper we present a significantly updated map of mafic dykes for the West Africa Craton based in large part on new interpretations of the regional airborne magnetic database. This map includes the locations of over three thousand dykes across the craton, which locally shows several orientation clusters that provide a minimum estimate for the total number of dyke swarms in this region. Whilst we will have to wait until systematic dating of the different swarms is completed, we can demonstrate that there is a long and complex history of mafic magmatism across the craton, with up to 26 distinct dyke swarms mapped based according to their orientation. The mapping and dating of these swarms will provide key constraints on the assembly of the fragments that make up the modern continents.
DS200512-0382
2005
Santra, M.Gupta, S., Nanda, J., Mukerjee, S.K., Santra, M.Alkaline magmatism versus collision tectonics in the eastern Ghats Belt, India: constraints from structural studies in the Koraput Complex.Gondwana Research, Vol. 8, 3, pp. 403-420.India, AsiaAlkaline rocks, magmatism
DS201412-0964
2014
Santsh, M.Wang, W., Liu, S., Santsh, M., Zhang, L., Bai, X., Zhao, Y., Zhang, S., Guo, R.1.23 Ga mafic dykes in the North Chin a craton and their implications for the reconstruction of the Columbia supercontinent.Gondwana Research, in press availableChinaSupercontinents
DS201511-1827
2015
Santsh, M.Cai, Y-C., Fan, H-R., Santsh, M., Hu, F-F., Yang, K-F, Hu, Z.Subduction related metasomatism of the lithospheric mantle beneath the southeastern North Chin a Craton: evidence from mafic to intermediate dykes in the northern Sulu orogen.Tectonophysics, Vol. 659, pp. 137-151.ChinaSulu orogen - dykes

Abstract: The widespread mafic to intermediate dykes in the northern Sulu orogen provide important constrains on mantle source characteristics and geodynamic setting. Here we present LA-ICPMS zircon U-Pb ages which indicate that the dykes were emplaced during Early Cretaceous (~ 113-108 Ma). The rocks show SiO2 in the range of 46.2 to 59.5 wt.% and alkalic and shoshonitic affinity with high concentrations of MgO (up to 7.6 wt.%), Cr (up to 422 ppm) and Ni (up to 307 ppm). They are enriched in light rare earth elements LREE (La, Ce, Pr, Nd, Sm and Eu) and large ion lithophile elements (LILE, Rb, Sr, Ba, U and Th) and show strong depletion in high field strength elements (HFSE, Nb, Ta, Ti and P). The dykes possess uniformly high (87Sr/86Sr)i (0.70824-0.70983), low ?Nd(t) (? 14.0 to ? 17.4) and (206Pb/204Pb)i (16.66-17.02) and negative ?Hf(t) (? 23.5 to ? 13.7). Our results suggest that the source magma did not undergo any significant crustal contamination during ascent. The systematic variation trends between MgO and major and trace elements suggest fractionation of olivine and clinopyroxene. The highly enriched mantle source for these rocks might have involved melts derived from the subducted lower crust of Yangtze Craton that metasomatized the ancient lithospheric mantle of the North China Craton.
DS200412-0961
2003
Sany, Y.Katayama, I., Muko, A., Izuka, T., Maruyama, S., Terada, K., Tsutsumi, Y., Sany, Y., Zhang, R.Y., Liou, J.G.Dating of zircon from Ti clinohumite bearing garnet peridotite: implication for timing of mantle metasomatism.Geology, Vol. 31, 8, pp. 713-716.MantleGeochronology
DS1975-0048
1975
Sanya, P.Chatterjee, P.K., Dasgupta, D.R., Sanya, P.Research Work Done in Petrology and Mineralogy of the Geol.surv. of India Since 1851.India Geological Survey Records, Vol. 100, PT. 2, PP. 39-76.IndiaPetrology, Kimberlite
DS1960-0492
1964
Sanyal, S.P.Sanyal, S.P.Petrology of Certain Lamprophyres from the Jharia Coalfield, Bihar, with a Discussion on the Differentiation of Sudamdih Sill.India Geological Survey Miscellaneous Publishing, Vol. No. 8, PP. 27-44.India, BiharBlank
DS201312-0760
2013
Sanz de Galdeano, C.Ruiz-Cruz, M.D.,Sanz de Galdeano, C.Coesite and diamond inclusions, exsolution microstructures and chemical patterns in ultrahigh pressure garnet from Ceuta ( Northern Rif, Spain).Lithos, Vol. 177, pp. 184-206.Europe, SpainUHP
DS200512-1253
2005
Sanzhong, L.Zhao, G., Sun, M., Wilde, S.A., Sanzhong, L.Late Archean to Paleoproterozoic evolution of the North Chin a Craton: key issues revisited.Precambrian Research, Vol. 136, 2, Jan. pp. 177-202.ChinaTectonics, rifting
DS1989-0471
1989
SaparinGaranin, V.K., Kudryavtseva, G.P., Mikhaylichenko, O.A., SaparinDiscreteness of the natural diamond formation process. (Russian)Mineral. Zhurnal., (Russian), Vol. 11, No. 31, pp. 3-19RussiaDiamond morphology, Natural diamond
DS1998-1468
1998
SaparinTitkov, S.V., Bershov, Scandale, Saparin, ChukichevNickel structural impurities in natural diamonds7th International Kimberlite Conference Abstract, pp. 911-13.Russia, Yakutia, UralsDiamond morphology, Nickel inclusions
DS2002-0988
2002
SaparinMakeev, A.B., Ivanuch, Obyden, Saparin, FilippovMineralogy, composition of inclusions and cathodluminescence of carbonado from Bahia State.Geology of Ore Deposits, Vol.44,2,pp.87-102.Brazil, BahiaMineralogy, geochronology, Carbonado
DS1990-1623
1990
Saparin, G.V.Zezin, R.B., Saparin, G.V., Smirnova, E.P., Obyden, S.K., ChukichevCathodluminescence of natural diamonds from Jakutian depositsScanning, Vol. 12, No.6, Nov-Dec. pp. 326-333RussiaDiamond morphology, Cathodluminescence
DS1992-1733
1992
Saparin, G.V.Zezin, R.B., Smirnova, E.P., Saparin, G.V., Obyden, S.K.New growth features of natural diamonds, revealed by colour cathodluminescence scanning electron microscope (CCL SEM) techniqueScanning, Vol. 14, No. 1, Jan-Feb. pp. 3-10.# HC 517GlobalNatural diamond morphology, Cathodluminescence
DS1998-1284
1998
Saparin, G.V.Saparin, G.V., Obyden, S.K., Titkov, S.V.Use of cathodluminescence scanning electron microscope (SEM) with color TVdisplay for study natural diamonds -7th. Kimberlite Conference abstract, pp. 763-5.Russia, YakutiaDiamond morphology - structure, Luminescence - CL-scanning electron microscope (SEM).
DS2002-1597
2002
Saparin, G.V.Titkov, S.V., Saparin, G.V., Obyden, C.K.A study of the evolution of grwoth sectors in natural diamond crystals using cathodluminescence microscopy.18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.151.RussiaDiamond - crystallography
DS2002-1598
2002
Saparin, G.V.Titkov, S.V., Saparin, G.V., Obyden, S.K.Evolution of growth sectors in natural diamond crystals as revealed by cathodluminescence topography.Geology of Ore Deposits, Vol. 44, 5, pp. 350-63.GlobalDiamond morphology
DS2002-1666
2002
Saparin, G.V.Viktorov, M.A., Shelementiev, Yu.B., Saparin, G.V., Obyden, S.K., ChhukichevSpectroscopic properties of artifically coloured diamonds18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.149.GlobalDiamond - colouration
DS200412-1208
2003
Saparin, G.V.Makeyev, A.B., Iwanuch, W., Obyden, S.K., Bryachaninova, N.I., Saparin, G.V.Inter relation of diamond and carbonado ( based on study of collections from Brazil and Middle Timan).Doklady Earth Sciences, Vol. 393a, no. 9, pp.1251-5.Russia, South America, BrazilDiamond morphology
DS202106-0964
2021
Sapegina, A.V.Perchuk, A.L., Sapegina, A.V., Safonov, O.G., Yapaskurt, V.O., Shatsky, V.S., Malkovets, V.G.Reduced amphibolite facies conditions in the Precambrian continental crust of the Siberian craton recorded by mafic granulite xenoliths from the Udachnaya kimberlite pipe, Yakutia.Precambrian Research, Vol. 357, 1061022, 14p. PdfRussia, Yakutiadeposit - Udachnaya

Abstract: It is widely accepted that granulite xenoliths from kimberlites provide a record of granulite facies metamorphism at the basement of cratons worldwide. However, application of the phase equilibria modeling for seven representative samples of mafic granulites from xenoliths of the Udachnaya kimberlite pipe, Yakutia, revealed that a granulitic garnet + clinopyroxene + plagioclase ± orthopyroxene ± amphibole ± scapolite mineral assemblage was likely formed in the middle crust under amphibolite facies conditions (600-650 °C and 0.8-1.0 GPa) in a deficiency of fluid. Clinopyroxene in the rocks is characterized by elevated aegirine content (up to 10 mol.%) both in the earlier magmatic cores and in the later metamorphic rim zones of the grains. Nevertheless, the phase equilibrium modeling for all samples indicates surprisingly reduced conditions, i.e. oxygen fugacity 1.6-3.3 log units below the FMQ (Fayalite-Magnetite-Quartz) buffer. In contrast, the coexistence of Fe-Ti oxides indicates temperatures of 850-990 °C and oxygen fugacity about lg(FMQ) ± 0.5, conditions which correspond to earlier stages of rock evolution. Reduction of oxygen fugacity during cooling is discussed in the context of the evolution of a complex fluid. The reconstructed P-T conditions for the final equilibration in the mafic granulites indicate that temperatures were ~250 °C higher than those extrapolated from the continental conductive geotherm of 35-40 µW/m2 deduced from peridotite xenoliths of the Udachnaya pipe. Although the granulites resided in the crust for a period for at least 1.4 Ga, they did not re-equilibrate to the temperatures of the geotherm, likely due to the blocking of mineral reactions under relatively low temperatures and fluid-deficient conditions
DS2000-0038
2000
SaphonovaAshchepkov, V., Saphonova, Cheremnykh, Esin, KutolinXenoliths and basalts from the Sovgavan Plateau: regularities of mantle structure.Igc 30th. Brasil, Aug. abstract only 1p.MantleMagmatism - subduction, Basanites, websterites
DS202108-1298
2021
Sapin, F.Loparev, A., Rouby, D., Chardon, D., Dallasta, M., Sapin, F., Bajolet, P., Paquet, F.Superimposed rifting at the junction of the central and equatorial Atlantic: formation of the passive margin of the Guiana Shield.Tectonics, 10.1029/2020TC006159, 19p. PdfSouth AmericaGuiana Shield

Abstract: The continental margin of the Guiana Shield formed at the intersection of the Central and Equatorial Atlantic Oceans that developed one after the other and, in doing so, achieved the break-up of the Gondwana supercontinent. To form these Ocean, the continent crust was stretched and broke but the way this thinning is actually varying along the margin and the causes are not known so we used offshore industrial data to map it. This allows us showing that the width of the continental margin depends primarily on the direction along which the crust was thinned such that the continental margin width is much wider (200-300 km) in domains where this direction is perpendicular to the margin than in domain where it is oblique (<100 km). This also allow us showing that the continental margin resulting from the opening of the Central Atlantic Ocean is systematically wider than the one resulting from the opening of the Equatorial Atlantic. Additionally, our observations suggest that Central Atlantic Ocean opened under warmer conditions than the Equatorial Atlantic. Finally, the area at the intersection of the Central and Equatorial Atlantic Oceans, individualized a promontory of continental crust that formed the present-day Demerara Plateau.
DS1998-0752
1998
Sapin, V.I.Kirillov, V.E., Avchneko, O.V., Sapin, V.I.Apatite albite metasomatites in the Ulkan depression- volcanics, southeastern Aldan Shield.Doklady Academy of Sciences, Vol. 361A, No. 6, pp. 842-5.Russia, Aldan shieldMetasomatism - high alkaline volcanics
DS202001-0040
2019
Sapkota, J.Smithies, R.H., Lu, Y., Johnson, T.E., Kirkland, C.L., Cassidy, K.F., Champion, D.C., Mole, D.R., Zibra, I., Gessner, K., Sapkota, J., De Paoli, M.C., Poujol, M.No evidence for high pressure melting of Earth's crust in the Archean.Nature Communicatons, Vol. 10, 555912p. PdfAustraliamelting

Abstract: Much of the present-day volume of Earth’s continental crust had formed by the end of the Archean Eon, 2.5 billion years ago, through the conversion of basaltic (mafic) crust into sodic granite of tonalite, trondhjemite and granodiorite (TTG) composition. Distinctive chemical signatures in a small proportion of these rocks, the so-called high-pressure TTG, are interpreted to indicate partial melting of hydrated crust at pressures above 1.5?GPa (>50?km depth), pressures typically not reached in post-Archean continental crust. These interpretations significantly influence views on early crustal evolution and the onset of plate tectonics. Here we show that high-pressure TTG did not form through melting of crust, but through fractionation of melts derived from metasomatically enriched lithospheric mantle. Although the remaining, and dominant, group of Archean TTG did form through melting of hydrated mafic crust, there is no evidence that this occurred at depths significantly greater than the ~40?km average thickness of modern continental crust.
DS202001-0038
2019
Saplakoglu, Y.Saplakoglu, Y.Extraterrestrial mineral never before seen on Earth found inside a famous meteorite. Wedderburn ( found 1951 near Victoria)LiveScience.com, Sept. 4, 1p.Australiameteorite
DS202012-2246
2020
Sapozhnikov, M.Rogov, Y., Kremenets, V., Sapozhnikov, M., Sebele, M.Application of tagged neutron method for detecting diamonds in kimberlite.Instruments, Vol. 4, 4, doi.org/103390/ instruments4040033Globalneutron technology

Abstract: The results of testing a prototype of a separator for detecting diamonds in kimberlite ore using tagged neutron method are discussed. Kimberlite ore was irradiated with fast tagged neutrons with an energy of 14.1 MeV. The elemental content of the tray with kimberlite ore was determined. The criterion for detecting diamond was the presence of excess carbon concentration in a certain region of a kimberlite sample.
DS201604-0590
2015
Sapozhnikov, M.G.Alexakhin, V.Yu., Bystritsky, V.M., Zamyatin, N.I., Zubarev, E.V., Krasnoperov, A.V., Rapatsky, V.L., Rogov, Yu.N., Sadovsky, A.B., Salamatin, A.V., Salmin, R.A., Sapozhnikov, M.G., Slepnev, V.M., Khabarov, S.V., Razinkov,E.A., Tarasov, O.G., Nikitin,G.M.Detection of diamonds in kimberlite by the tagged neutron method.Nuclear Instruments and Methods in Physics Research Section A., A785, pp. 9-13.TechnologyMethodology

Abstract: A new technology for diamond detection in kimberlite based on the tagged neutron method is proposed. The results of experimental researches on irradiation of kimberlite samples with 14.1-MeV tagged neutrons are discussed. The source of the tagged neutron flux is a portable neutron generator with a built-in 64-pixel silicon alpha-detector with double-sided stripped readout. Characteristic gamma rays resulting from inelastic neutron scattering on nuclei of elements included in the composition of kimberlite are registered by six gamma-detectors based on BGO crystals. The criterion for diamond presence in kimberlite is an increased carbon concentration within a certain volume of the kimberlite sample.
DS200712-0576
2006
Sapozhnikov, R.Kostyuchenko, S., Sapozhnikov, R., Egorkin, A., Gee, D.G., Berzin, R., Solodilov, L.Crustal structure and tectonic model of northeastern Baltica, based on deep seismic and potential field data.Geological Society of London Memoir, No. 32, pp. 521-540.Europe, Baltic ShieldTectonics, geophysics
DS200712-0535
2006
Sapoznikov, R.B.Kheraskova, T.N., Sapoznikov, R.B., Volozh, Yu.A., Antipov, M.P.Geodynamics and evolution of the northern east European Platform in the late Precambrian as inferred from regional seismic profiling.Geotectonics, Vol. 40, 6, pp. 434-449.EuropeTectonics
DS201512-1963
2015
Sappin, A-A.Sappin, A-A., Beaudoin, G.Rare earth elements in Quebec, Canada: main deposit types and their economic potential.Symposium on critical and strategic materials, British Columbia Geological Survey Paper 2015-3, held Nov. 13-14, pp. 265-Canada, QuebecRare earths

Abstract: Rare earth elements (REE) are strategic metals vital to global economic growth because they are used in a wide range of high-technology industries (e.g., energy, transport, and telecommunications; Walters et al., 2011). The world production and reserves are mainly owned by China. In 2008, the Chinese government introduced export quotas on rare metals, which led to a global search for new sources of REE. Québec has substantial REE resources (Simandl et al., 2012), which may contribute to future production. Gosselin et al. (2003) and Boily and Gosselin (2004) inventoried rare metals (REE, Zr, Nb, Ta, Be, and Li) occurrences and deposits in Québec and, based mainly on lithological association, subdivided them into seven types: 1) deposits associated with peraluminous granitic complexes; 2) deposits associated with carbonatite complexes; 3) deposits associated with peralkaline complexes; 4) deposits associated with placers and paleoplacers; 5) iron oxide, Cu, REE, and U deposits; 6) deposits associated with granitic pegmatites, migmatites, and peraluminous to metaluminous granites; and 7) deposits associated with calc-silicate and metasomatized rocks or skarns. Herein we review REE mineralization in the province, adopting a more genetic scheme based on the classifi cation of Walters et al. (2011). The REE occurrences and deposits are subdivided into primary deposits, formed by magmatic and/ or hydrothermal processes, and secondary deposits, formed by sedimentary processes and leaching. Primary deposits are then subdivided into four types: 1) carbonatite complex-associated; 2) peralkaline igneous rock-associated; 3) REE-bearing Iron- Oxide-Copper-Gold (IOCG) deposits; and 4) hyperaluminous/ metaluminous granitic pegmatite-, granite-, and migmatiteassociated deposits, and skarns. Secondary deposits are subdivided into two deposit types: 1) placers and paleoplacers and 2) REE-bearing ion-adsorption clays.
DS2001-0056
2001
SaprykinAshchepkov, I.V., Gerasimov, Saprykin, Vladykin, AnoshinTrace element composition of deep seated mineral inclusions from Aldan lamproites: first la ICP MS studyGeological Association of Canada (GAC) Annual Meeting Abstracts, Vol. 26, p.5, abstract.RussiaLamproites, Amga River basin
DS2001-0058
2001
SaprykinAshchepkov, L.V., Vladykin, Gerasimov, SaprykinPetrology and mineralogy of disintegrated mantle inclusions of kimberlite like diatremes from Aldan areaAlkaline Magmatism -problems mantle source, pp. 161-76.Russia, Aldan shieldMantle reconstructions - Chompolo field
DS200412-0063
2004
SaprykinAshchepkov, I.V., Vladykin, N.V., Nikolaeva, I.V., Palessky, Logvinova, Saprykin, Khmelnikova, AnoshinMineralogy and geochemistry of mantle inclusions and mantle column structure of the Yubileinaya kimberlite pipe, Alakit field, YDoklady Earth Sciences, Vol. 395, 4, March-April, pp. 378-384.Russia, YakutiaDiamond - mineralogy, Jubilenya
DS200512-0032
2003
SaprykinAshchepkov, I.V., Vladykin, N.V., Loginova, A.M., Nikolaeva, Palessky, Khmelnikova, Saprykin, RotmanYubileynaya pipe: from mineralogy to mantle structure and evolution.Plumes and problems of deep sources of alkaline magmatism, pp. 20-38.RussiaGenesis - Jubileynaya
DS200512-0035
2003
SaprykinAshchepkov, I.V., Vladykin, N.V., Rotman, A.Y., Nikolaeva, Palessky, Anoshin, Khmelnikova, SaprykinMinerals from Zarnitsa pipe kimberlite: the key to enigma of the mantle composition and construction.Plumes and problems of deep sources of alkaline magmatism, pp. 51-64.RussiaMineralogy - Zarnitsa
DS200512-0036
2004
SaprykinAshchepkov, I.V., Vladykin, Rotman, Loginova, Afanasiev, Palessky, Saprykin, Anoshin, Kuchkin, KhmelnikovaMir and Internationalnaya kimberlite pipes - trace element geochemistry and thermobarometry of mantle minerals.Deep seated magmatism, its sources and their relation to plume processes., pp. 194-208.RussiaGeobarometry - Mir, International
DS200612-0046
2005
SaprykinAshchepkov, I.V., Vladykin, Rotman, Afansiev, Loginova, Kuchkin, Palessky, Nikolaeva, Saprykin, AnoshinVariations of the mantle mineralogy and structure beneath Upper - Muna kimberlite field.Problems of Sources of Deep Magmatism and Plumes., pp. 170-187.RussiaMineralogy
DS201012-0019
2009
SaprykinAshchepkov, I.V., Rotman, Nossyko, Somov, Shimupi, Vladykin, Palessky, Saprykin, KhmelnikovaComposition and thermal structure of mantle beneath the western part of the Congo-Kasai craton according to xenocrysts from Angola kimberlites.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., p. 158-180.Africa, AngolaGeothermometry
DS202106-0922
2021
Saprykin, A.Ashchepkov, I.,Medvedev, N.,Ivanov, A., Vladykin, N., Ntafos,T.,Downes, H.,Saprykin, A.,Tolstov, A.Vavilov, M., Shmarov, G.Deep mantle roots of the Zarnitsa kimberlite pipe, Siberian craton, Russia: evidence for multistage polybaric interaction with mantle melts.Journal of Asian Earth Sciences, Vol. 213, 104756, 22p.pdfRussia, Siberiadeposit - Zarnitsa

Abstract: Zarnitsa kimberlite pipe in Central Yakutia contains pyrope garnets with Cr2O3 ranging from 9 to 19.3 wt% derived from the asthenospheric mantle. They show mostly S-shaped, inflected rare earth element (REE) patterns for dunitic and harzburgitic, lherzolitic and harzburgitic varieties and all are rich in high field strength elements (HFSE) due to reaction with protokimberlite melts. Lithospheric garnets (<9 wt% Cr2O3) show a similar division into four groups but have more symmetric trace element patterns. Cr-diopsides suggest reactions with hydrous alkaline, protokimberlitic and primary (hydrous) partial melts. Cr-diopsides of metasomatic origin have inclined REE patterns and high LILE, U, Th and Zr concentrations. Four groups in REE of Ti-rich Cr-diopsides, and augites have asymmetric bell-like REE patterns and are HFSE-rich. Mg-ilmenites low in REE were formed within dunite conduits. Ilmenite derived from differentiated melts have inclined REE patterns with LREE ~ 100 × chondrite levels. Thermobarometry for dunites shows a 34 mWm?2 geotherm with a HT branch (>50 mWm?2) at 6-9 GPa, and a stepped HT geotherm with heated pyroxenite lenses at four levels from 6.5 to 3.5 GPa. Parental melts calculated with KDs suggest that augites and high-Cr garnets in the lithosphere base reacted with essentially carbonatitic melts while garnets from lower pressure show subduction peaks in U, Ba and Pb. The roots of the Zarnitsa pipe served to transfer large portions of deep (>9 GPa) protokimberlite melts to the lithosphere. Smaller diamonds were dissolved due to the elevated oxidation state but in peripheral zones large diamonds could grow.
DS2001-0377
2001
Saprykin, A.I.Gerasimov, P.A., Saprykin, A.I., Ashchepkov, AnoshinDetermination of rare earth elements (REE) in different minerals from mantle xenoliths by la ICPMS.Geological Association of Canada (GAC) Annual Meeting Abstracts, Vol. 26, p.50-1, abstract.MantleXenoliths
DS200512-0031
2002
Saprykin, A.I.Ashchepkov, I.V., Saprykin, A.I., Gerasim, Khmeintkova, Cheremenykk, Safonova, Rasskazov, Kinolin, VladykinPetrochemistry of mantle xenoliths from Sovgavan Plateau, Far East Russia.Deep Seated Magmatism, magmatism sources and the problem of plumes., pp. 213-222.RussiaXenoliths
DS200512-0034
2004
Saprykin, A.I.Ashchepkov, I.V., Vladykin, N.V., Rotman, A.Y., Loginova, A.M., Nikolaeva, L.A., Palessky, V.S., Saprykin, A.I., Anoshin, G.N., Kuchkin, A., Khmelnikova, O.S.Reconstructions of the mantle layering beneath the Alakite kimberlite field: comparative characteristics of the mineral geochemistry and TP sequences.Deep seated magmatism, its sources and their relation to plume processes., pp. 160-177.RussiaGeochemistry - Alakite
DS200512-0037
2001
Saprykin, A.I.Ashchepkov,I.V., Vladykin, N.V., Gerasimov, P.A., Saprykin, A.I., Khmelnikova, O.S., Anoshin, G.N.Petrology and mineralogy of disintegrated mantle inclusions of kimberlite like diatremes from the Aldan Shield ( Chompolo field): mantle reconstructions.Alkaline Magmatism and the problems of mantle sources, pp. 161-176.RussiaDiatreme
DS202007-1124
2020
Saprykin, A.I.Ashchepkov, I.V., Vladykin, N.V., Kalashnyk, H.A., Medvedev, N.S., Saprykin, A.I., Downes, H., Khmelnikova, O.S.Incompatible element enriched mantle lithosphere beneath kimberlitic pipes in Priazovie Ukrainian shield: volatile enriched focused melt flow and connection to mature crust?International Geology Review, in press available 24p. PdfEurope, Ukrainedeposit - Priazovie

Abstract: Major, minor and trace element compositions of mantle xenocrysts from Devonian kimberlite pipes in the Priazovie give an insight into the mantle structure beneath the SE Ukranian Shield and its evolution. Garnets yield low temperature conditions as determined by monomineral thermobarometry. The mantle lithosphere is sharply divided at 4.2 GPa, marked by a high temperature Cpx-Ilm-Phl trend, eclogites and changes in pyrope geochemistry. Seven layers are detected: Ist layer at 2.5-1 GPa is enriched mantle (Fe#Ol ~ 0.11 ? 0.14) with Gar- pyroxenites and Sp peridotites; IInd at 2.5-3.2 GPa - Gar-Sp (Fe#Ol 0.08 ? 0.10) peridotite. IIId at 4.3-3.2 GPa is formed of Archaean- Proterozoic peridotites with Fe#Ol ~0.07 ? 0.095. IVth at 3.2-5 GPa- contains pyroxenitic Gar with higher Ca, eclogites, Chr and Cpx (Fe#Ol ~0.10 ? 0.125); Vth at 5.8 ? 5 GPa is marked by sub-Ca garnets, Cr-rich chromites and Mg-Cr ilmenites; VIth layer at 5.8-6.8 GPa contains Fe-enriched pyropes, almandines and Cr-Mg ilmenites near the lithosphere base; VIIth layer > 6.8 GPa consists of ‘hot’ Fe-rich garnets. Garnets show increasing enrichment in LREE, LILE, Hf, Zr with decreasing pressure. Primitive garnets have round REE patterns; depleted ones have S-type patterns inflected at Nd. Garnets from 6.5 to 3 GPa show increasing La/Ybn, Zr-Hf, LILE. Peridotitic clinopyroxenes have inclined linear trace element patterns rounded from La to Pr with high LILE and HFSE levels. The Fe-rich group (reacted with eclogites) shows bell-shaped irregular patterns with LILE close to the LREE levels. A possible reason for LILE (HFSE and) enrichment of the upper part of the mantle is subduction metasomatsm in Archaean times (with participation of mature continental sediments) activated by plumes at 1.8 Ga and earlier which produced pervasive focused melt flow with remelting of mica-amphibole metasomatites giving continuous REE and LILE enrichment in mantle lithologies from 5.8 to 2.5 GPa.
DS202011-2029
2001
Saprykin, A.I.Ashchepkov, I.V., Afanasiev, V.P., Pokhilenko, N.P., Sobolev, N.V., Vladykin, N.V., Saprykin, A.I., Khmelnikova, O.S., Anoshin, G.N.Small note on the composition of Brazilian mantle. *** NOTE DATERevista Brasileira de Geociencas*** ENG, Vol. 31, 4, pp. 653-660. pdfSouth America, Brazilkimberlites

Abstract: Garne ts from couc eru ratc from the vargcm l kimberl ite pipe show a long compos itional range and reveallong lincar tre nds within the lherzolite field in a Cr~Ol - CaO% dia gram (Sobolcv et til. 1974) (lip (0 11% MgO). fon ned by grains of different dimensions with fcw deviations to harzburg itcs . Larger grains (fraction +3) arc higher in CaO with less Cr~01 (to 5.5%). TIle Cr20 1 freq uen cy reduc es in hyperbo lic function for each fraction . IImenites reve;1142-56% Ti0 2l..'Olllpositionai range with linear FeO - MgO correhuions but 3(4) separate groups for A I ~01 suggest different proport ion of co-prccipimted gimlet , probably due to polybn ric Irncnonanon. lncreasing Cr~O l nnd r"t..-Q% conte nt (fractionation uegn:e ) with red ucing TiO~ is in accord with Ar c mod el.. Ganict xenolith fnnnldnin II pipe with large Ga r- Cpxgrains and fine Mica-Curb bearing mat rix refer to 60 kbcr and 35 mv/m2 gcothcrm . 11displays enr iched trace c lement pat ter ns but not completely equilibrated compositions for Ga r anti Cpx. sugges ting low degree me lting of rela tively fertile mantle. St udied uuuc rinlmay s uggcsrmcrasomu tized, relat ively fertile and irre gularly heated mantle bene ath Sombcrn Bra zil as found by (Carvalho & Lccnnrdos 1997).
DS202107-1088
2021
Saprykin, A.I.Ashchepkov, V., Vladykin, N.V., Kalashnyk, H.A., Medvedev, N.S., Saprykin, A.I., Downes, H., Khmelnikova, O.S.Incompatible element-enriched mantle lithosphere beneath kimberlitic pipes in Proazovie, Ukrainian shield: volatile enriched focused melt flow and connection to mature crust?International Geology Review, Vol. 63, 10, pp. 1288-1309.Europe, Ukrainedeposit - Priazovie

Abstract: Major, minor and trace element compositions of mantle xenocrysts from Devonian kimberlite pipes in the Priazovie give an insight into the mantle structure beneath the SE Ukranian Shield and its evolution. Garnets yield low temperature conditions as determined by monomineral thermobarometry. The mantle lithosphere is sharply divided at 4.2 GPa, marked by a high temperature Cpx-Ilm-Phl trend, eclogites and changes in pyrope geochemistry. Seven layers are detected: Ist layer at 2.5-1 GPa is enriched mantle (Fe#Ol ~ 0.11 ? 0.14) with Gar- pyroxenites and Sp peridotites; IInd at 2.5-3.2 GPa - Gar-Sp (Fe#Ol 0.08 ? 0.10) peridotite. IIId at 4.3-3.2 GPa is formed of Archaean- Proterozoic peridotites with Fe#Ol ~0.07 ? 0.095. IVth at 3.2-5 GPa- contains pyroxenitic Gar with higher Ca, eclogites, Chr and Cpx (Fe#Ol ~0.10 ? 0.125); Vth at 5.8 ? 5 GPa is marked by sub-Ca garnets, Cr-rich chromites and Mg-Cr ilmenites; VIth layer at 5.8-6.8 GPa contains Fe-enriched pyropes, almandines and Cr-Mg ilmenites near the lithosphere base; VIIth layer > 6.8 GPa consists of ‘hot’ Fe-rich garnets. Garnets show increasing enrichment in LREE, LILE, Hf, Zr with decreasing pressure. Primitive garnets have round REE patterns; depleted ones have S-type patterns inflected at Nd. Garnets from 6.5 to 3 GPa show increasing La/Ybn, Zr-Hf, LILE. Peridotitic clinopyroxenes have inclined linear trace element patterns rounded from La to Pr with high LILE and HFSE levels. The Fe-rich group (reacted with eclogites) shows bell-shaped irregular patterns with LILE close to the LREE levels. A possible reason for LILE (HFSE and) enrichment of the upper part of the mantle is subduction metasomatsm in Archaean times (with participation of mature continental sediments) activated by plumes at 1.8 Ga and earlier which produced pervasive focused melt flow with remelting of mica-amphibole metasomatites giving continuous REE and LILE enrichment in mantle lithologies from 5.8 to 2.5 GPa.
DS2001-0055
2001
Saprykin, et al.Ashchepkov, I.V. , Vladykin, Gerasimov, Saprykin, et al.Temperature gradient and structure of the lithospheric block beneath the southeastern margin of Siberia cratonDoklady Academy of Sciences, Vol. 378, No. 4, May-June pp. 530-35.Russia, Siberia, Aldan shieldXenolith evidence from kimberlites, Geothermometry
DS1989-1338
1989
Saquaque, A.Saquaque, A., Admou, H., Karson, J., Hefferan, K., Reuber, I.Precambrian accretionary tectonics in the Bou-Azzer-El Graara region, Anti-Atlas, MoroccoGeology, Vol. 17, No. 12, December pp. 1107-1110MoroccoOphiolite, Late Proterozoic
DS2000-0401
2000
Saquaque, A.Hefferan, K.P., Admou, H., Saquaque, A.Anti-Atlas (Morocco) role in Neoproterozoic western GondwanaPrecambrian Research, Vol. 103, No. 1-2, Sept. pp.89-96.MoroccoTectonics, Gondwana
DS200512-0105
2004
Saquaque, A.Bouougri, E.H., Saquaque, A.Lithostratigraphic framework and correlation of the Neoproterozoic northern West African Craton passive margin sequence Siroua Zenaga Bouazzer Elgraara InliersJournal of African Earth Sciences, Vol. 39, 3-5, pp. 227-238.Africa, MoroccoStratigraphy, integrated approach
DS1991-1922
1991
Saradeth, S.Zeil, P., Volk, P., Saradeth, S.Geophysical methods for lineament studies in groundwater exploration: acase history from southeast BotswanaGeoexploration, Vol. 27, No. 1-2, February pp. 165-178BotswanaGeophysics, Lineaments
DS1984-0596
1984
Saradhi, D.V.Prasad, E.A.V., Saradhi, D.V.Termite Mounds in Geochemical ProspectingCurrent Science., Vol. 53, No. 12, JUNE 20TH. PP. 649-651.India, KondapalliGeochemistry
DS1989-1339
1989
Saraev, A.K.Saraev, A.K.Use of results of borehole measurements of the Q Factor of traps insolving geological problems for objects of the Yakutsk diamond provinceSoviet Geology and Geophysics, Vol. 30, No. 2, pp. 101-108RussiaYakutsk area, Q factor -traps
DS200512-0935
2002
Saraev, A.K.Saraev, A.K., Pertel, M.I., Nikiforov, A.B., Garat, M.N., Manakov, A.B., Ingerov, O.I.Magnetotelluric exploration for kimberlite pipes in Yakutian Province, Sakha Republic, Russia.Phoenix Geophysics Preprint, English, Jan. 7p. text 17 figuresRussia, Siberia, YakutiaGeophysics - magnetotellurics, Almakinskaya, Mirensky
DS201909-2089
2019
Saraev, S.V.Simonov, V.A., Kontorovich, V.A., Stupakov, S.I., Filippov, Y.F., Saraev, S.V., Kotlyarov, A.V.Setting of the formation of Paleozoic picrite basalt complexes in the west Siberian plate basement.Doklady Earth Sciences, Vol. 486, 2, pp. 613-616.Russia, Siberiapicrites

Abstract: 40Ar/39Ar analysis showed a simultaneous (at about 490 Ma) formation of the Paleozoic picrite and basalt complexes of the West Siberian Plate basement. The petrochemistry, trace and REE geochemistry, and composition of clinopyroxene indicate the formation of the picrite of well no. 11 (Chkalov area) as a result of intraplate magmatism of the OIB type. Calculations based on the compositions of clinopyroxene allowed crystallization of minerals of porphyric picrite at 1215-1275°C and 4.5-8 kbar. In general, it has been found that the picrite basalt complexes considered were formed from enriched igneous plume systems under intraplate conditions near the active margin of the ancient ocean.
DS1989-1340
1989
Saraf, A.K.Saraf, A.K., Cracknell, A.P.Linear discriminant and profile analysis. an aid in remote sensing forgeo botanical investigationInternational Journal of Remote Sensing, Vol. 10, No. 11, November pp. 1735-1948GlobalGeobotany, Remote sensing
DS1995-0385
1995
saraf, A.K.Das, J.D. , saraf, A.K., Jain, A.K.Fault tectonics of the Shilong plateau and adjoining regions, north-east India using remote sensing dataInternational Journal of Remote Sensing, Vol. 16, No. 9, June pp. 1633-46IndiaRemote Sensing, Tectonics
DS2002-1400
2002
Saraf, A.K.Saraf, A.K., Mishra, P., Mitra, S., et al.Remote sensing and GIS technologies for improvements in geological structures interpretation and mapping.International Journal of Remote Sensing, Vol.23,No.13, July 20, pp. 2527-36.GlobalRemote sensing - not specific to diamonds, Techniques
DS201704-0645
2017
Sarafian, A.R.Sarafian, E., Gaetani, G.A., Hauri, E.H., Sarafian, A.R.Experimental constraints on the damp peridotite solidus and oceanic mantle potential temperature.Science, Vol. 355, 6328, pp. 942-945.MantleGeothermometry

Abstract: Decompression of hot mantle rock upwelling beneath oceanic spreading centers causes it to exceed the melting point (solidus), producing magmas that ascend to form basaltic crust ~6 to 7 kilometers thick. The oceanic upper mantle contains ~50 to 200 micrograms per gram of water (H2O) dissolved in nominally anhydrous minerals, which -relative to its low concentration-has a disproportionate effect on the solidus that has not been quantified experimentally. Here, we present results from an experimental determination of the peridotite solidus containing known amounts of dissolved hydrogen. Our data reveal that the H2O-undersaturated peridotite solidus is hotter than previously thought. Reconciling geophysical observations of the melting regime beneath the East Pacific Rise with our experimental results requires that existing estimates for the oceanic upper mantle potential temperature be adjusted upward by about 60°C.
DS201704-0645
2017
Sarafian, E.Sarafian, E., Gaetani, G.A., Hauri, E.H., Sarafian, A.R.Experimental constraints on the damp peridotite solidus and oceanic mantle potential temperature.Science, Vol. 355, 6328, pp. 942-945.MantleGeothermometry

Abstract: Decompression of hot mantle rock upwelling beneath oceanic spreading centers causes it to exceed the melting point (solidus), producing magmas that ascend to form basaltic crust ~6 to 7 kilometers thick. The oceanic upper mantle contains ~50 to 200 micrograms per gram of water (H2O) dissolved in nominally anhydrous minerals, which -relative to its low concentration-has a disproportionate effect on the solidus that has not been quantified experimentally. Here, we present results from an experimental determination of the peridotite solidus containing known amounts of dissolved hydrogen. Our data reveal that the H2O-undersaturated peridotite solidus is hotter than previously thought. Reconciling geophysical observations of the melting regime beneath the East Pacific Rise with our experimental results requires that existing estimates for the oceanic upper mantle potential temperature be adjusted upward by about 60°C.
DS201802-0263
2018
Sarafian, E.Sarafian, E., Evans, R.L., Abdelsalam, M.G., Atekwana, E., Elsenbeck, J., Jones, A.G., Chikambwe, E.Imaging Precambrian lithospheric structure in Zambia using electromagnetic methods.Gondwana Research, Vol. 54, pp. 38-49.Africa, Zambiageophysics

Abstract: The Precambrian geology of eastern Zambia and Malawi is highly complex due to multiple episodes of rifting and collision, particularly during the formation of Greater Gondwana as a product of the Neoproterozoic Pan-African Orogeny. The lithospheric structure and extent of known Precambrian tectonic entities of the region are poorly known as there have been to date few detailed geophysical studies to probe them. Herein, we present results from electromagnetic lithospheric imaging across Zambia into southern Malawi using the magnetotelluric method complemented by high-resolution aeromagnetic data of the upper crust in order to explore the extent and geometry of Precambrian structures in the region. We focus particularly on determining the extent of subcontinental lithospheric mantle (SCLM) beneath the Archean-Paleoproterozoic cratonic Bangweulu Block and the Mesoproterozoic-Neoproterozoic Irumide and Southern Irumide Orogenic Belts. We also focus on imaging the boundaries between these tectonic entities, particularly the boundary between the Irumide and Southern Irumide Belts. The thickest and most resistive lithosphere is found beneath the Bangweulu Block, as anticipated for stable cratonic lithosphere. Whereas the lithospheric thickness estimates beneath the Irumide Belt match those determined for other orogenic belts, the Southern Irumide Belt lithosphere is substantially thicker similar to that of the Bangweulu Block to the north. We interpret the thicker lithosphere beneath the Southern Irumide Belt as due to preservation of a cratonic nucleus (the pre-Mesoproterozoic Niassa Craton). A conductive mantle discontinuity is observed between the Irumide and Southern Irumide Belts directly beneath the Mwembeshi Shear Zone. We interpret this discontinuity as modified SCLM relating to a major suture zone. The lithospheric geometries determined from our study reveal tectonic features inferred from surficial studies and provide important details for the tectonothermal history of the region.
DS201903-0507
2019
Sarafian, E.Evans, R.L., Elsenbeck, J., Zhu, J., Abelsalam, M.G., Sarafian, E., Mutamina, D., Chilongola, F., Atekwan, E., Jones, A.G.Structure of the lithosphere beneath the Barotse Basin, western Zambia from magnetotelluric data.Tectonics, in press available Africa, Zambiamelting

Abstract: A magnetotelluric survey in the Barotse Basin of western Zambia shows clear evidence for thinned lithosphere beneath an orogenic belt. The uppermost asthenosphere, at a depth of 60-70 km, is highly conductive, suggestive of the presence of a small amount of partial melt, despite the fact that there is no surface expression of volcanism in the region. Although the data support the presence of thicker cratonic lithosphere to the southeast of the basin, the lithospheric thickness is not well resolved and models show variations ranging from ~80 to 150 km in this region. Similarly variable is the conductivity of the mantle beneath the basin and immediately beneath the cratonic lithosphere to the southeast, although the conductivity is required to be elevated compared to normal lithospheric mantle. In a general sense, two classes of model are compatible with the magnetotelluric data: one with a moderately conductive mantle and one with more elevated conductivities. This latter class would be consistent with the impingement of a stringer of plume?fed melt beneath the cratonic lithosphere, with the melt migrating upslope to thermally erode lithosphere beneath the orogenic belt that is overlain by the Barotse Basin. Such processes are potentially important for intraplate volcanism and also for development or propagation of rifting as lithosphere is thinned and weakened by melt. Both models show clear evidence for thinning of the lithosphere beneath the orogenic belt, consistent with elevated heat flow data in the region.
DS201904-0733
2019
Sarafian, E.Evans, R.L., Elsenbeck, J., Zhu, J., Abdelsalam, M.G., Sarafian, E., Mutamina, D., Chilongola, F., Atekwana, E.A., Jones, A.G.Structure of the lithosphere beneath the Barotse basin, western Zambia, from magnetotelluric data.Tectonics, Vol. 38, 2, pp. 666-686.Africa, Zambiageophysics

Abstract: A magnetotelluric survey in the Barotse Basin of western Zambia shows clear evidence for thinned lithosphere beneath an orogenic belt. The uppermost asthenosphere, at a depth of 60-70 km, is highly conductive, suggestive of the presence of a small amount of partial melt, despite the fact that there is no surface expression of volcanism in the region. Although the data support the presence of thicker cratonic lithosphere to the southeast of the basin, the lithospheric thickness is not well resolved and models show variations ranging from ~80 to 150 km in this region. Similarly variable is the conductivity of the mantle beneath the basin and immediately beneath the cratonic lithosphere to the southeast, although the conductivity is required to be elevated compared to normal lithospheric mantle. In a general sense, two classes of model are compatible with the magnetotelluric data: one with a moderately conductive mantle and one with more elevated conductivities. This latter class would be consistent with the impingement of a stringer of plume?fed melt beneath the cratonic lithosphere, with the melt migrating upslope to thermally erode lithosphere beneath the orogenic belt that is overlain by the Barotse Basin. Such processes are potentially important for intraplate volcanism and also for development or propagation of rifting as lithosphere is thinned and weakened by melt. Both models show clear evidence for thinning of the lithosphere beneath the orogenic belt, consistent with elevated heat flow data in the region.
DS201509-0426
2015
Saraiva dos Santos, T.J.Saraiva dos Santos, T.J., Da Silva Amaral, W., Ancelmi, M.F., Pitarello, M.Z., Fuck, R.A., Dantas, E.L.U-Pb age of coesite bearing eclogite from NW Borborema Province, NE Brazil: implications for western Gondwana assembly.Gondwana Research, Vol. 28, pp. 1183-1196.South America, BrazilUHP

Abstract: The Late Neoproterozoic assembly of western Gondwana played an important role in the subduction of oceanic and continental lithospheres. Such event was also a source of arc magmatism, reworking of cratonic margins and development of ultra-high pressure (UHP) suture zones. In the Borborema province, NE Brazil, we have described for the first time UHP rocks enclosed within gneiss migmatite and calc-silicate rocks. They bear coesite included in atoll-type garnet from metamafic rocks, identified by petrographic study and Raman microspectroscopy analysis. U-Pb zircon dating of the leucosome of the migmatites and the calc-silicate rock displays, concordant ages of 639 ± 10 Ma and 649.7 ± 5 Ma, respectively, here interpreted as the minimum age of the eclogitization event in the region. U-Pb zircon dating of the coesite-bearing rock defined a concordia age of 614. 9 ± 7.9 Ma that comprised the retrograde eclogitic conditions to amphibolite facies. The UHP rocks, mostly retrograded to garnet amphibolites, occur enclosed in the Paleoproterozoic continental block composed of calc-silicate rocks, migmatized sillimanite gneiss, mylonitic augen gneiss and granitic and tonalitic gneiss along a narrow N-S oriented belt between the Santa Quitéria magmatic arc and the Transbrasiliano lineament. This block was involved in the subduction to UHP eclogite depths, and was retrogressed to amphibolite during its exhumation and thrusting. Our data indicate an important Neoproterozoic transcontinental suture zone connecting the Pharusian belt with Borborema Province, and probably with the Brasília belt in central Brazil.
DS200612-1223
2005
Sarala, P.Sarala, P.Till geochemistry in the ribbed moraine area of Perapohjola, Finland.Applied Geochemistry, Vol. 20, pp. 1714-1736.Europe, FinlandGeochemistry - not specific to diamonds
DS201612-2333
2016
Sarala, P.Sarala, P.Comparison of different portable XRF methods for determining till geochemistry.Geochemistry: Exploration, Environment, Analysis, Vol. 16, 3-4, pp. 181-192.TechnologyGeochemistry

Abstract: Three portable X-ray fluorescence (pXRF) methods were compared and tested in an exploration program using till in Sinoselkä, northern Finland. The use of one truck-mounted XRF unit and two handheld pXRF analysers were tested for basal till samples gathered using percussion drilling with a flow-through sampling bit. The datasets were compared to both conventional aqua regia based analyses and each other. The results prove that a correlation between the data generated by different pXRF methods was acceptable for some major (Ca, Fe) and most of the base metal elements (like As, Cr, Cu, Mn, Ni, Pb, Zn) in the Sinoselkä area. The pXRF analyses also correlate well with the aqua regia geochemical data of the same elements. Distribution of the elements was comparable to the lithological changes in the underlying bedrock that indicates a short glacial transport distance. It is also demonstrated that more than absolute values, the relative values and their changes are those which should be considered and carefully examined. The results reported here emphasize the usefulness of pXRF analysers in till geochemical exploration and demonstrate that they involve easy and fast methods to collect geochemical data for tracing sources of multi-metal mineralization. Furthermore, pXRF is applicable in gold exploration, although indicator elements like As, Bi, Cu, Mn and Sb have to be used instead of Au.
DS2002-1401
2002
Sarangi, B.Sarangi, B., Sahoo, H.K.Detailed survey to locate kimberlite/lamproite pipes already identified blocks in Bolangir Baragarh and Kalandi Districts, Orissa.Records of the Geological Survey of India, Vol. 133, 3, eastern 1998-1999, pp.193-195.India, OrissaGeochemistry
DS200412-1730
2002
Sarangi, B.Sarangi, B., Sahoo, H.K.Detailed survey to locate kimberlite/lamproite pipes already identified blocks in Bolangir Baragarh and Kalandi Districts, OrissRecords of the Geological Survey of India, Vol. 133, 3, eastern 1998-1999, pp.193-195.India, OrissaGeochemistry
DS2002-1001
2002
SaraninaMartynov, Y.A., Chaschin, Rasskazov, SaraninaLate Miocene Pliocene basaltic volcanism in the south of the Russian far East as an indicator of ...Petrology, Vol.10,2,pp.165-83.RussiaLithospheric mantle, heterogeneity continent-ocean
DS200712-0876
2007
SaraninaRasskazov, S.V., Ilyasova, A.M., Konev, A.A., Yasnygina, Maslovskaya, Feflov, Demonterova, SaraninaGeochemical evidence of the Zadoi alkaline ultramafic Massif, Cis Sayan area southern Siberia.Geochemistry International, Vol. 45, 1, pp. 1-14.Russia, SiberiaAlkalic
DS2002-1312
2002
Saranina, E.V.Rassakazov, S.V., Saranina, E.V., Logachev, IvanovThe DUPAL mantle anomaly of the Tuva Mongolian Massif and its paleogeodynamic implication.Doklady, Vol.382, 1, Jan-Feb.pp. 44-8.MongoliaGeodynamics
DS2002-1002
2002
SaraniniaMartynov, Yu.A., Chaschin, Rasskazov, SaraniniaLate Miocene- Pliocene basaltic volcanism in the south of Russia Far East, an indicator of lithospheric mantlePetrology, Vol. 10, 2, pp. 165-83.Russia, Far EastHeterogeneity in continent - ocean transition zone
DS201312-0013
2013
Sarapaa, O.Al Ani, T., Sarapaa, O.Geochemistry and mineral phases of REE in Jammi carbonatite veins and fenites, southern end of the Sokli complex, NE Finland.Geochemistry: Exploration, Environment, Analysis, Vol. 13, 2, pp. 217-224.Europe, FinlandCarbonatite
DS200912-0204
2009
Sarar, S.Eriksson, P.G., Banerjee, S., Nelson, D.R., Rigby, M.J., Catuneau, O., Sarar, S., Roberts, R.J., Ruban, D., Mtimkulu, M.N., Sunder Raju, P.V.A Kaapvaal craton debate: nucleus of an early small supercontinent or affected by an enhanced accretion event?Gondwana Research, Vol. 15, 3-4, pp. 354-372.Africa, South AfricaAccretion
DS201610-1919
2016
Sarasev, A.A.Yelisseyev, A.P., Afansiev, V.P., Panchenko, A.V., Gromilov, S.A., Kaichev, V.V., Sarasev, A.A.Yakutites: are they impact diamonds from the Popigai crater?Lithos, in press available 14p.RussiaImpact diamonds

Abstract: Yakutites are coarse (up to 15 mm or larger) aggregates dispersed for more than 500 km around the Popigai meteorite crater. They share many features of similarity with impact diamonds found inside the crater, in elemental and phase compositions, texture, and optical properties as revealed by X-ray photoelectron spectroscopy, X-ray diffraction, and optical spectroscopy (Raman, absorption, luminescence and microscopic) studies. The N3 vibronic system appearing in the luminescence spectra of Popigai impact diamonds (PIDs) indicates a presence of nitrogen impurity and a high-temperature annealing of diamonds that remained in the crater after solid-phase conversion from graphite. Yakutites lack nitrogen-vacancy centers as signatures of annealing, which may indicate quenching at the time of ejection. Thus, both PIDs and yakutites originated during the Popigai impact event and yakutites were ejected to large distances.
DS200712-0938
2006
Sarasota Herald TribuneSarasota Herald TribuneDiamonds lure visitors to a park in Arkansas. Crater of Diamonds.Sarasota Herald Tribune, Nov. 11, 1/2p.United States, ArkansasNews item - history
DS200712-0939
2007
Sarasota Herald TribuneSarasota Herald TribuneDiamonds from the lab. Two full pages on Gemesis. V. O'Connell's article from Wall Street Journal.Sarasota Herald Tribune, Jan. 21, 2p.TechnologyNews item - Gemesis
DS201012-0661
2010
Sarasota Herald TribuneSarasota Herald TribuneTiffany looking good.Sarasota Herald Tribune, March 23, 1p.GlobalNews item - Tiffany
DS202107-1115
2021
Sarathi, J.P.Mukerjee, A., Tiwari, P., Verma, C.B., Babu, E.V.S.S.K., Sarathi, J.P.Native gold and Au-Pt alloy in eclogite xenoltihs of Kalyandurg KL-2 kimberlite, Anantapur district, South India.Journal of the Geological Society of India, Vol. 97, pp. 567-570.Indiadeposit - Kalyandurg

Abstract: The paper pertains to the studies carried out on the eclogitic xenoliths of KL-2 kimberlite of Kalyandurg kimberlite cluster in south India. Petrographic studies revealed bi-mineralic and kyanite-bearing eclogitic xenoliths in KL-2 kimberlite. The bimineralic and kyanite-bearing eclogites of Kalyandurg KL-2 kimberlite pipe show variation in modal proportion of garnet, omphacite, clinopyroxene and kyanite. The paper reports discovery of native gold grains and Au-Pt alloy in the kyanite-bearing eclogite xenoliths of KL-2 kimberlite. The flaky gold grains occurring in the matrix of kyanite-bearing eclogite are homogeneous and two grains of Au-Pt alloy with Au and Pt in the proportion of 9.8:1.2 are also present. This is the first report of gold and gold-platinum alloy specs from eclogitic xenoliths of Indian kimberlites.
DS200912-0666
2009
Sarava dos Santos, T.J.Sarava dos Santos, T.J., Garcia, M.M., Amarai, W.S., Caby, R., Wernick, E., Arthaud, M.H., Dantas, E.L., Santosh, M.Relics of eclogite facies assemblages in the Ceara central domain, NW Borborema Province, NE Brazil: implications for the assembly of West Gondwana.Gondwana Research, Vol. 15, 3-4, pp. 454-470.South America, BrazilTectonics
DS1995-1659
1995
Saravanan, S.Saravanan, S., Ramasamy, R.Geochemistry and petrogenesis of shonkinite and associated alkaline Rocks of Tiruppattur carbonatite complex.Journal of Geological Society India, Vol. 46, No. 3, Sept. pp. 235-244.IndiaCarbonatite, Deposit -Tiruppattur
DS2001-1011
2001
Sarayev, A.K.Sarayev, A.K., et al.Magnetotelluric exploration for kimberlite pipes in Yakutian Province, Sakha Republic, Russia.Geological Association of Canada (GAC) Annual Meeting Abstracts, Vol. 26, p. 132.abstract.Russia, YakutiaGeophysics - magnetotellurics
DS2001-1012
2001
Sarayev, A.K.Sarayev, A.K., et al.Possibilities of magnetotellurics for kimberlite exploration at Russian platform.Geological Association of Canada (GAC) Annual Meeting Abstracts, Vol. 26, p. 132.abstract.Russia, YakutiaGeophysics - magnetotellurics
DS2001-1013
2001
Sarayev, A.L.Sarayev, A.L., Pertel, Garat, Manakov, AlexandrovPossibilities of magnetotellurics for kimberlite exploration in the Russian PlatformNorth Atlantic Minerals Symposium held May 27-30, pp. 149. abstract.RussiaGeophysics - magnetotellurics
DS202005-0731
2020
Saraykin, V.V.Galimov, E.M., Kaminsky, F.V., Shilobreeva, S.N., Sevastyanov, V.S., Voropaev, S.A., Khachatryan, G.K., Wirth, R., Schreiber, A., Saraykin, V.V., Karpov, G.A., Anikin, L.P.Enigmatic diamonds from the Tolbachik volcano, Kamchatka.American Mineralogist, Vol. 105, pp. 498-509. pdfRussiadeposit - Tolbachik

Abstract: Approximately 700 diamond crystals were identified in volcanic (mainly pyroclastic) rocks of the Tolbachik volcano, Kamchatka, Russia. They were studied with the use of SIMS, scanning and transmission electron microscopy, and utilization of electron energy loss spectroscopy and electron diffraction. Diamonds have cube-octahedral shape and extremely homogeneous internal structure. Two groups of impurity elements are distinguished by their distribution within the diamond. First group, N and H, the most common structural impurities in diamond, are distributed homogeneously. All other elements observed (Cl, F, O, S, Si, Al, Ca, and K) form local concentrations, implying the existence of inclusions, causing high concentrations of these elements. Most elements have concentrations 3-4 orders of magnitude less than chondritic values. Besides N and H, Si, F, Cl, and Na are relatively enriched because they are concentrated in micro- and nanoinclusions in diamond. Mineral inclusions in the studied diamonds are 70-450 nm in size, round- or oval-shaped. They are represented by two mineral groups: Mn-Ni alloys and silicides, with a wide range of concentrations for each group. Alloys vary in stoichiometry from MnNi to Mn2Ni, with a minor admixture of Si from 0 to 5.20-5.60 at%. Silicides, usually coexisting with alloys, vary in composition from (Mn,Ni)4Si to (Mn,Ni)5Si2 and Mn5Si2, and further to MnSi, forming pure Mn-silicides. Mineral inclusions have nanometer-sized bubbles that contain a fluid or a gas phase (F and O). Carbon isotopic compositions in diamonds vary from -21 to -29‰ ?13CVPDB (avg. = -25.4). Nitrogen isotopic compositions in diamond from Tolbachik volcano are from -2.32 to -2.58‰ ?15NAir. Geological, geochemical, and mineralogical data confirm the natural origin of studied Tolbachik diamonds from volcanic gases during the explosive stage of the eruption.
DS200912-0447
2009
SarbadhikariLiu, Y., Taylor, L.A., Sarbadhikari, Valley, Ushikubo, Spicuzza, Kita, Ketchum, Carlson, Shatsky, SobolevMetasomatic origin of diamonds in the world's largest Diamondiferous eclogite.Lithos, In press - available 41p.RussiaDeposit - Udachnaya
DS201707-1361
2017
Sarbajna, C.Saha, A., Ganguly, S., Ray, J., Koeberl, C., Thoni, M., Sarbajna, C., Sawant, S.S.Petrogenetic evolution of Cretaceous Samchampi Samteran alkaline complex, Mikir Hills, northeast India: implications on multiple melting events of heterogeneous plume and metasomatized sub continental lithospheric mantle.Gondwana Research, Vol. 48, pp. 237-256.Indiacarbonatite

Abstract: The Samchampi (26° 13?N: 93° 18?E)-Samteran (26° 11?N: 93° 25?E) alkaline complex (SSAC) occurs as an intrusion within Precambrian basement gneisses in the Karbi-Anglong district of Assam, Northeastern India. This intrusive complex comprises a wide spectrum of lithologies including syenite, ijolite-melteigite, alkali pyroxenite, alkali gabbro, nepheline syenite and carbonatite (nepheline syenites and carbonatites are later intrusives). In this paper, we present new major, trace, REE and Sr-Nd isotope data for different lithologies of SSAC and discuss integrated petrological and whole rock geochemical observations with Sr-Nd isotope systematics to understand the petrogenetic evolution of the complex. Pronounced LILE and LREE enrichment of the alkaline-carbonatite rocks together with steep LREE/HREE profile and flat HREE-chondrite normalized patterns provide evidence for parent magma generation from low degree partial melting of a metasomatized garnet peridotite mantle source. LILE, HFSE and LREE enrichments of the alkaline-silicate rocks and carbonatites are in agreement with the involvement of a mantle plume in their genesis. Nb-Th-La systematics with incompatible trace element abundance patterns marked by positive Nb-Ta anomalies and negative K, Th and Sr anomalies suggest contribution from plume-derived OIB-type mantle with recycled subduction component and a rift-controlled, intraplate tectonic setting for alkaline-carbonatite magmatism giving rise to the SSAC. This observation is corroborated by enriched 87Sr/86Srinitial (0.705562 to 0.709416) and 143Nd/144Ndinitial (0.512187 to 0.512449) ratios for the alkaline-carbonatite rocks that attest to a plume-related enriched mantle (~ EM II) source in relation to the origin of Samchampi-Samteran alkaline complex. Trace element chemistry and variations in isotopic data invoke periodic melting of an isotopically heterogeneous, metasomatized mantle and generation of isotopically distinct melt batches that were parental to the different rocks of SSAC. Various extents of plume-lithosphere interaction also accounts for the trace element and isotopic variations of SSAC. The Srinitial and Ndinitial (105 Ma) isotopic compositions (corresponding to ?Nd values of ? 6.37 to ? 1.27) of SSAC are consistent with those of Sung Valley, Jasra, Rajmahal tholeiites (Group II), Sylhet Traps and Kerguelen plateau basalts.
DS200712-0615
2007
Sarbas, B.Lehnert, K., Walker, D., Sarbas, B.EarthChem - geochemistry dat a network.Plates, Plumes, and Paradigms, 1p. abstract p. A559.TechnologyDatabase
DS1860-0160
1871
Sarcelle (Pseud for Payton), C.A. Sir.Sarcelle (Pseud for Payton), C.A. Sir.Facts from the Diamond Fields of South AfricaLondon: J. Tennant., 7P.Africa, South Africa, Cape ProvinceTravelogue
DS202108-1277
2021
Sarda, P.Derycke, A., Gautheron, C., Barbarand, J., Bourbon, P., Aertgeerts, G., Simon-Labric, T., Sarda, P., Pinna-Jamme, R., Boukari, C., Gaurine, F.French Guiana margin evolution: from Gondwana break-up to Atlantic Ocean.Terra Nova, Vol. 33, 4, pp. 415-422. pdfSouth America, French GuianaGuiana Shield

Abstract: Knowledge of the Guiana Shield evolution during the Gondwana break-up is key to a better understanding of craton dynamics and margin response to transtensional opening. To improve this knowledge, we investigated the dynamics and thermal evolution of French Guiana, using several low-temperature thermochronology methods applied to basement rocks, including apatite and zircon (U-Th)/He and apatite fission tracks. Inverse modelling of results allows us to reconstruct the Phanerozoic thermal history of French Guiana margin and to give a preview of the Guiana Shield evolution. Three main events are inferred: firstly, a long-term period of relative stability since ~1.2 Ga, with no strong evidence for any erosional or burial event (>5-7 km); secondly, a heating phase between ~210 and ~140 Ma consistent with the Central Atlantic Magmatic Province-related event. Finally, an exhumation phase between ~140 and ~90 Ma, triggered by the Equatorial Atlantic opening, brought samples close to the surface (<40°C).
DS1984-0449
1984
Sardela, I.A.Leite, C.R., Barelli, N., Sardela, I.A.Oriented Enstatite Inclusions in Natural DiamondMineralogical Magazine., Vol. 48, No. 348, PT. 3, SEPT. PP. 459-461.BrazilMineralogy
DS1995-1715
1995
Sarelainen, B.V.Sharkov, E.V., Sarelainen, B.V., Quick, J.E., Lazko, BoginaArbanksy Massif in the eastern Siberia -the largest in Russia block of the Early Precambrian upper mantle.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 506-8.Russia, SiberiaArbansky Massif, Eclogites
DS200712-0940
2007
Sarewitz, D.Sarewitz, D., Pielke, R.A.Jr.The neglected heart of science policy: reconciling supply of and demand for science.Environmental Science and Policy, Vol. 10, 1, pp. 5-26.GlobalResearch necessary
DS201801-0055
2018
Sarfian, E.Sarfian, E., Evans, R.L, Abdelsalam, M.G., Atekwana, E., Elsenbeck, J., Jones, A.G., Chikambwe, E..Imaging Precambrian lithospheric structure in Zambia using electromagnetic methods.Gondwana Research, Vol. 54, pp. 38-49.Africa, Zambiageophysics -em
DS1985-0586
1985
Sargent, M.L.Sargent, M.L., Buschbach, T.C.Map of the Morphology of the Top of Precambrian Crystalline rocks in Illinois.Geological Society of America (GSA), Vol. 17, No. 5, MARCH P. 324. (abstract.).United States, Great Lakes, IllinoisBlank
DS200512-0936
2005
Sarkadi, L.Sarkadi, L.A question of aboriginal rights.Canadian Diamonds, Winter pp. 26-33.Africa, Botswana, Canada, Northwest Territories, OntarioNews item - aboriginal rights
DS1980-0298
1980
Sarkar, A.Sarkar, A., Paul, D.K., Balasubrahmanyan, M.N., Sengupta, N.R.Lamprophyres from Indian Gondwanas Potassium-argon Ages and ChemistryGeological Society INDIA Journal, Vol. 21, MARCH PP. 188-193.IndiaGeochronology, Petrography, Chemistry
DS2002-1371
2002
Sarkar, A.Roy, A., Sarkar, A., Jeyakumar, S., Aggrawal, S.K., Ebihara, M.Sm Nd age and mantle source characteristics of the Dhanjori volcanic rocks, eastern India.Geochemical Journal, Vol. 36, 5, pp. 503-18.IndiaGeochronology, magmatism
DS200512-0915
2004
Sarkar, A.Roy, A., Sarkar, A., Jeyakumar, S., Aggrawal, S.K., Ebihara, M., Satoh, H.Late Archean mantle metasomatism below eastern Indian Craton: evidence from trace elements, REE geochemistry and Sr Nd O isotope systematics of ultramafic dykes.Proceedings National Academy of Sciences India , Vol. 113, 4, pp. 649-666. Ingenta 1045680437IndiaMetasomatism, geochemistry
DS200512-0916
2004
Sarkar, A.Roy, A., Sarkar, A., Jeyakumar, S., Aggrawal, S.K., Ebihara, M., Satoh, H.Late Archean mantle metasomatism below eastern Indian craton: evidence from trace elements, REE geochemistry and Sr Nd O isotope systematics of ultramafic dykes.Proceedings National Academy of Sciences India , Vol. 113, 4, pp. 649-665.India, AsiaPeridotite, harzburgite, geochronology
DS201809-2107
2018
Sarkar, A.Vadlamani, R., Bera, M.K., Samata, A., Mukherjee, S., Adhikari, A., Sarkar, A.Oxygen, Sr and Nd isotopic evidence from kyanite eclogite xenoliths ( KL-2 pipe, Wajrakarur) for pre 1.1 Ga mantle metasomatism in eastern Dharwar SCLM.Goldschmidt Conference, 1p. AbstractIndiadeposit - KL-2

Abstract: Kyanite-eclogite xenoliths from Wajrakarur are considered as remnants of subducted ocean-floor crust. Here trace element concentration and isotopic data are presented in garnet (Grt) and kyanite (Ky) from xenoliths KL-2 E1-E4, characterized by. We use the precise 87Sr/86Sr host kimberlite groundmass perovskite ratio (0.70312-0.70333, as a proxy for the extent of kimberlitic magma infiltration at 1.1 Ga. The xenolithic Grt and Cr-rich (upto 1506 ppm) Ky have more radiogenic 87Sr/86Sr values than kimberlite, at 1.1 Ga, of 0.703829-0.705203 and 0.703811-0.704502, respectively. Furthermore, the Grt and Ky 143Nd/144Nd ratios, at 1.1 Ga, are 0.509321-0.511372 and 0.510951-0.511156, respectively, and are distinctly lower than those of the host kimberlite (0.511870-0.512290). This indicates that the infiltration of kimberlitic fluid has not altered the 87Sr/86Sr and 143Nd/144Nd ratios in the Grt and Ky, and therefore their isotope compositions must be inherited and predate the kimberlite magma generation event at 1.1 Ga. Trace elements in Grt and Ky indicate extreme metasomatism (Sr in Grt 104-296 ppm, in Ky 672-8713 ppm [limit Sr<2ppm] and Nb in Grt 0.64-1.78 ppm, in Ky 1.7-4.54 ppm [limit Nb<0.5ppm]). The xenoliths underwent at least one major melting event inferred from extreme depletions in Re, Os and 177Os/178Os ratios [5]. Their mantle-like ?18O values (Grt 5.3-5.4‰, Ky 5.3-5.9‰), positive Eu anomalies in both Grt and Ky (similar to Group 1 HREE-depleted garnets of) suggests that the protolith likely was a chromite-bearing leucogabbro, emplaced as a high-pressure cumulate at the crust-mantle boundary, which was later eclogitized due to deep-seated subduction and underwent episodes of extreme melting and metasomatism before 1.1 Ga and at least before 1.7 Ga, as inferred from their youngest Re depletion dates.
DS201909-2100
2019
Sarkar, A.Vadlamani, R., Bera, M.K., Samanta, A., Mukherjee, S., Adhikari, A., Sarkar, A.Oxygen, Sr and Nd isotopic evidence from kyanite-eclogite xenoliths ( KL-2 pipe, Wajrakarur) for pre- 1.1 Ga mantle metasomatism in eastern Dharwar SCLM.Goldschmidt2019, 1p. AbstractIndiadeposit - KL-2

Abstract: Kyanite-eclogite xenoliths from Wajrakarur are considered as remnants of subducted ocean-floor crust [1]. Here trace element concentration and isotopic data are presented in garnet (Grt) and kyanite (Ky) from xenoliths KL-2 E1-E4, characterized by [2]). We use the precise 87Sr/86Sr host kimberlite groundmass perovskite ratio (0.70312-0.70333, [3]) as a proxy for the extent of kimberlitic magma infiltration at 1.1 Ga. The xenolithic Grt and Cr-rich (upto 1506 ppm) Ky have more radiogenic 87Sr/86Sr values than kimberlite, at 1.1 Ga, of 0.703829-0.705203 and 0.703811-0.704502, respectively. Furthermore, the Grt and Ky 143Nd/144Nd ratios, at 1.1 Ga, are 0.509321-0.511372 and 0.510951-0.511156, respectively, and are distinctly lower than those of the host kimberlite (0.511870-0.512290, [4]). This indicates that the infiltration of kimberlitic fluid has not altered the 87Sr/86Sr and 143Nd/144Nd ratios in the Grt and Ky, and therefore their isotope compositions must be inherited and predate the kimberlite magma generation event at 1.1 Ga. Trace elements in Grt and Ky indicate extreme metasomatism (Sr in Grt 104-296 ppm, in Ky 672-8713 ppm [limit Sr<2ppm] and Nb in Grt 0.64-1.78 ppm, in Ky 1.7-4.54 ppm [limit Nb<0.5ppm]). The xenoliths underwent at least one major melting event inferred from extreme depletions in Re, Os and 177Os/178Os ratios [5]. Their mantle-like ?18O values (Grt 5.3-5.4‰, Ky 5.3-5.9‰), positive Eu anomalies in both Grt and Ky (similar to Group 1 HREE-depleted garnets of [1]) suggests that the protolith likely was a chromite-bearing leucogabbro, emplaced as a high-pressure cumulate at the crust-mantle boundary, which was later eclogitized due to deep-seated subduction and underwent episodes of extreme melting and metasomatism before 1.1 Ga and at least before 1.7 Ga, as inferred from their youngest Re depletion dates [5].
DS201012-0662
2010
Sarkar, B.Sarkar, B.Mineral chemistry and structural relationships of inclusions in diamond crystals.International Mineralogical Association meeting August Budapest, AbstractTechnologyDiamond inclusions
DS201012-0663
2010
Sarkar, C.Sarkar, C., Storey, C., Hawkesworth, C., Sparks, S., Field, M.Fingerprinting of kimberlite sources by isotope studies of accessory minerals: a mantle tracer.Goldschmidt 2010 abstracts, P. 553. abstractTechnologyGeochronology, perovskites
DS201112-0914
2011
Sarkar, C.Sarkar, C., Storey, C.D., Hawkesworth, C.J., Sparks, R.S.J.Degassing in kimberlite: oxygen isotope ratios in perovskites from explosive and hypabyssal kimberlites.Earth and Planetary Science Letters, Vol. 312, 3-4, pp. 291-299.Africa, Botswana, South AfricaDeposit - Orapa, Wesselton
DS201112-0915
2011
Sarkar, C.Sarkar, C., Storey, C.D., Hawkesworth, C.J., Sparks, R.S.J.Oxygen isotopes in perovskites from kimberlites.Goldschmidt Conference 2011, abstract p.1798.Africa, Botswana, South AfricaOrapa, Wesselton
DS201212-0623
2012
Sarkar, C.Sarkar, C., Storey, C.D., Hawkesworth, C.J., Sparks, R.S.J.Trace element nd isotope geochemistry of perovskite from kimberlites of southern Africa.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractAfrica, South AfricaGeochemistry
DS201312-0777
2013
Sarkar, C.Sarkar, C., Heaman, L., Pearson, D.G.Detailed geochemical studies of Lac de Gras kimberlites - redefining the 'diamond age window'?Geoscience Forum 40 NWT, abstract only p. 43Canada, Northwest TerritoriesDeposit - Lac de gras ones
DS201312-0778
2013
Sarkar, C.Sarkar, C., Storey, C.D.Detailed protracted crystallization history of perovskite in Orapa kimberlite.Proceedings of the 10th. International Kimberlite Conference, Vol. 1, Special Issue of the Journal of the Geological Society of India,, Vol. 1, pp. 211-224.Africa, BotswanaDeposit - Orapa
DS201312-0779
2014
Sarkar, C.Sarkar, C., Storey, C.D., Hawkesworth, C.J.Using perovskite to determine the pre-shallow level contamination magma characteristics of kimberlite.Chemical Geology, Vol. 363, pp. 76-90.Africa, South Africa, BotswanaDeposit - Wesselton, Orapa
DS201504-0215
2015
Sarkar, C.Sarkar, C., Heaman, L.M., Pearson, D.G.Duration and periodicity of kimberlite volcanic activity in the Lac de Gras kimberlite field, Canada and some recommendations for kimberlite geochronology.Lithos, Vol. 218-219, pp. 155-166.Canada, Northwest TerritoriesDeposit - Eddie
DS201605-0894
2016
Sarkar, C.Sarkar, C.Dating kimberlite magmatism and new results from the Slave and Rae cratons.DCO Edmonton Diamond Workshop, June 8-10Canada, Northwest territoriesGeochronology
DS201610-1903
2016
Sarkar, C.Reimink, J.R., Davies, J.H.F.L., Chacko, T., Stern, R.A., Heaman, L.M., Sarkar, C., Schaltegger, U., Creaser, R.A., Pearson, D.G.No evidence for Hadean continental crust within Earth's oldest evolved rock unit. (Acasta Gneiss Complex)Nature Geoscience, Vol. 9, pp. 777-780.CanadaHadean crust

Abstract: Due to the acute scarcity of very ancient rocks, the composition of Earth’s embryonic crust during the Hadean eon (>4.0 billion years ago) is a critical unknown in our search to understand how the earliest continents evolved. Whether the Hadean Earth was dominated by mafic-composition crust, similar to today’s oceanic crust1, 2, 3, 4, or included significant amounts of continental crust5, 6, 7, 8 remains an unsolved question that carries major implications for the earliest atmosphere, the origin of life, and the geochemical evolution of the crust-mantle system. Here we present new U-Pb and Hf isotope data on zircons from the only precisely dated Hadean rock unit on Earth—a 4,019.6 ± 1.8?Myr tonalitic gneiss unit in the Acasta Gneiss Complex, Canada. Combined zircon and whole-rock geochemical data from this ancient unit shows no indication of derivation from, or interaction with, older Hadean continental crust. Instead, the data provide the first direct evidence that the oldest known evolved crust on Earth was generated from an older ultramafic or mafic reservoir that probably surfaced the early Earth.
DS201612-2329
2016
Sarkar, C.Reimink, J.R., Davies, J.H.F.L., Chacko, T., Stern, R.A., Heaman, L.M., Sarkar, C., Schaltegger, U., Creaser, R.A., Pearson, D.G.No evidence for Hadean continental crust within Earth's oldest evolved rock unit.Nature Geoscience, Vol. 9, pp. 777-780.CanadaAcasta Gneiss

Abstract: Due to the acute scarcity of very ancient rocks, the composition of Earth’s embryonic crust during the Hadean eon (>4.0 billion years ago) is a critical unknown in our search to understand how the earliest continents evolved. Whether the Hadean Earth was dominated by mafic-composition crust, similar to today’s oceanic crust1, 2, 3, 4, or included significant amounts of continental crust5, 6, 7, 8 remains an unsolved question that carries major implications for the earliest atmosphere, the origin of life, and the geochemical evolution of the crust-mantle system. Here we present new U-Pb and Hf isotope data on zircons from the only precisely dated Hadean rock unit on Earth—a 4,019.6 ± 1.8?Myr tonalitic gneiss unit in the Acasta Gneiss Complex, Canada. Combined zircon and whole-rock geochemical data from this ancient unit shows no indication of derivation from, or interaction with, older Hadean continental crust. Instead, the data provide the first direct evidence that the oldest known evolved crust on Earth was generated from an older ultramafic or mafic reservoir that probably surfaced the early Earth.
DS201708-1749
2017
Sarkar, C.Sarkar, C.Geochronology and mantle source characteristics of kimberlites and related rocks from the Rae Craton, Melville Peninsula, Nunavut, Canada.11th. International Kimberlite Conference, PosterCanada, Nunavut, Melville Peninsulageochronology
DS201709-2016
2017
Sarkar, C.Kjarsgaard, B.A., Heaman, L.M., Sarkar, C., Pearson, D.G.The North American mid-Cretaceous kimberlite corridor: wet, edge-driven decompression melting of an OIB-type deep mantle source.Geochemistry, Geophysics, Geosystems: G3, Vol. 18, 7, pp. 2727-2747.Canada, Somerset Island, Saskatchewan, United States, Kansasmagmatism, convection, diamond genesis

Abstract: Thirty new high-precision U-Pb perovskite and zircon ages from kimberlites in central North America delineate a corridor of mid-Cretaceous (115–92 Ma) magmatism that extends ?4000 km from Somerset Island in Arctic Canada through central Saskatchewan to Kansas, USA. The least contaminated whole rock Sr, Nd, and Hf isotopic data, coupled with Sr isotopic data from groundmass perovskite indicates an exceptionally limited range in Sr-Nd-Hf isotopic compositions, clustering at the low ?Nd end of the OIB array. These isotopic compositions are distinct from other studied North American kimberlites and point to a sublithospheric source region. This mid-Cretaceous kimberlite magmatism cannot be related to mantle plumes associated with the African or Pacific large low-shear wave velocity province (LLSVP). All three kimberlite fields are adjacent to strongly attenuated lithosphere at the edge of the North American craton. This facilitated edge-driven convection, a top-down driven processes that caused decompression melting of the transition zone or overlying asthenosphere. The inversion of ringwoodite and/or wadsleyite and release of H2O, with subsequent metasomatism and synchronous wet partial melting generates a hot CO2 and H2O-rich protokimberlite melt. Emplacement in the crust is controlled by local lithospheric factors; all three kimberlite fields have mid-Cretaceous age, reactivated major deep-seated structures that facilitated kimberlite melt transit through the lithosphere.
DS201809-2082
2018
Sarkar, C.Sarkar, C., Kjarsgaard, B.A., Pearson, D.G., Heaman, L.M., Locock, A.J., Armstrong, J.P.Geochronology, classification and mantle source characteristics of kimberlites and related rocks from the Rae craton, Melville Peninsula, Nunavut, Canada.Mineralogy and Petrology, doi.org/10.1007/ s00710-018-0632-5 20p.Canada, Nunavut, Melville Peninsuladeposit - Pelly Bay, Darby, Aviat, Qilalugaq

Abstract: Detailed geochronology along with petrographic, mineralogical and geochemical studies have been conducted on recently found diamond-bearing kimberlitic and related rocks in the Rae Craton at Aviat and Qilalugaq, Melville Peninsula, north-east Canada. Magmatic rocks from the Aviat pipes have geochemical (both bulk rock and isotopic) and mineralogical signatures (e.g., core to rim Al and Ba enrichment in phlogopite) similar to Group I kimberlite. In contrast, Aviat intrusive sheets are similar to ‘micaceous’ Group II kimberlite (orangeite) in their geochemical and mineralogical characteristics (e.g., phlogopite and spinel compositions, highly enriched Sr isotopic signature). Qilalugaq rocks with the least crustal contamination have geochemical and mineralogical signatures [e.g., high SiO2, Al2O3 and H2O; low TiO2 and CO2; less fractionated REE (rare earth elements), presence of primary clinopyroxene, phlogopite and spinel compositions] that are similar to features displayed by olivine lamproites from Argyle, Ellendale and West Greenland. The Naujaat dykes, in the vicinity of Qilalugaq, are highly altered due to extensive silicification and carbonation. However, their bulk rock geochemical signature and phlogopite chemistry are similar to Group I kimberlite. U-Pb perovskite geochronology reveals that Aviat pipes and all rocks from Qilalugaq have an early Cambrian emplacement age (540-530 Ma), with the Aviat sheets being ~30 Ma younger. This volatile-rich potassic ultramafic magmatism probably formed by varying degrees of involvement of asthenospheric and lithospherically derived melts. The spectrum of ages and compositions are similar to equivalent magmatic rocks observed from the nearby north-eastern North America and Western Greenland. The ultimate trigger for this magmatism could be linked to Neoproterozoic continental rifting during the opening of the Iapetus Ocean and breakup of the Rodinia supercontinent.
DS202002-0197
2019
Sarkar, C.Krebs, M.Y., Pearson, D.G., Fagan, A.J., Bussweiler, Y., Sarkar, C.The application of trace elements and Sr-Pb isotopes to dating and tracing ruby formation: the Aappaluttoq deposit, SW Greenland.Chemical Geology, Vol. 523, pp. 42-58.Europe, Greenlandruby

Abstract: Trace element characteristics of rubies from the Aappaluttoq deposit, SW Greenland, were measured using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), laser ablation - inductively coupled plasma-time of flight-mass spectrometry (LA-ICP-TOF-MS) and offline laser ablation followed by solution ICP-MS. LA-ICP-TOF-MS - applied to rubies for the first time - effectively maps trace element spatial variation in these gems. With the exception of a small number of elements that can substitute for Al3+ in the crystal structure (e.g., Ti, Fe, V, Cr, Mg), trace element mapping clearly demonstrates that most elements such as Th, U, Sr and Rb are hosted in mineral and fluid inclusions or are present along fractures. Primitive mantle normalized trace element patterns show characteristics that are broadly correlative to mineral inclusions within the analysed rubies. These minerals include rutile (enrichment of HFSE over LREE, high Ta/Nb and Hf/Zr ratios and low Th/U ratios), phlogopite (enrichment in Rb and Ba and positive Sr anomalies), and zircon (extreme enrichment in Zr-Hf, U and Th, HREE enrichment over LREE and positive Ce anomalies). The sample suite analysed here is derived from a bulk sample of ore composed of three different rock types (sapphirine-gedrite, leucogabbro and phlogopitite). Two different populations of ruby were identified at Aappaluttoq; these can be defined on the basis of their different V content within the corundum lattice. Therefore, V content may be able to geochemically define rubies from different host rocks within the same deposit. Using offline laser ablation followed by thermal ionization mass spectrometry (TIMS) we measured the radiogenic isotope compositions in ruby for the first time. A Pb-Pb isochron age of 2686 +300/?74?Ma, was defined for gem formation at Aappaluttoq. We believe that this is the first ever direct age determined on a ruby suite, independent of associated minerals, derived by bulk sampling sub-micron to micron sized inclusions in the corundum lattice. This age likely reflects the re-crystallization and re-setting of the ruby (and its U-Pb system) during the Neoarchean in SW Greenland, due to regional granulite to upper-amphibolite facies metamorphism.
DS202008-1452
2020
Sarkar, C.Tovey, M., Giuliani, A., Phillips, D., Sarkar, C., Pearson, D.G., Nowicki, T., Carlson, J.Decoupling of kimberlite source and primitive melt compositions.Goldschmidt 2020, 1p. AbstractSouth America, Brazil, Africa, South Africa, Canada, Northwest Territoriesgeochronology

Abstract: Kimberlites emplaced since ~2 Ga show Nd and Hf isotopic compositions that follow a remarkably consistent linear evolution [1]. However, kimberlites emplaced <200 Ma within a few thousand kilometers of the western paleo-margin of Pangea (i.e. Brazil, southern Africa, and Lac de Gras in western Canada) deviate towards more enriched Nd and Hf isotopic compositions possibly due to contribution by recycled crustal material, introduced to the deep kimberlite source via subduction [1]. To address this anomaly further we have compared new and existing geochronological and Nd isotopic data for 28 kimberlites from Lac de Gras (LDG; ca. 47 - 75 Ma) with their olivine and spinel mineral chemistries. Olivine grains typically include mantle-derived xenocrystic cores (Mg# = 83.5-94.2) overgrown by magmatic rims with relatively constant Mg# values. Olivine rims and chromite are the first magmatic phases to crystallise from kimberlite and can be used as proxies for primitive melt compositions. The average Mg# of olivine cores from each kimberlite is positively correlated with average olivine rim Mg#, suggesting that assimilation of heterogeneous lithospheric mantle contributed to the primitive melt compositions. The ?Nd(i) values from whole-rock and perovskite from LDG kimberlites vary between -3.4 and -0.4 that are negatively correlated with their emplacement ages. This correlation is indicative of an evolving kimberlite source which may have resulted from a progressively lower contribution of recycled material. No systematic relationships were observed between olivine rim or chromite compositions and age or Nd isotopic composition. This observation highlights decoupling between kimberlite source evolution and primitive melt compositions due to the combined effects of crustal recycling in the kimberlite source and lithospheric mantle assimilation during kimberlite ascent.
DS202201-0016
2021
Sarkar, C.Grutter, H., Stachel, T., Sarkar, C., Pearson, G.Profound ~ 1075 Ma (re)fertilization of the central Superior craton lithosphere, based on composition and Pb-isotope data for clinopyroxenes from the Victor mine, Ontario, Canada.GAC/MAC Meeting UWO, 1p. Abstract p.117.Canada, Ontariodeposit - Victor

Abstract: The Victor diamond mine in Ontario, Canada opened in 2008 and ceased operations in June 2019. Previous researchers documented that Victor diamonds are unusually young (~ 720 Ma, Aulbach et al., 2018) and grew predominantly in unusually fertile peridotite substrates, specifically garnet lherzolite and garnet wehrlite (Stachel et al., 2018). Our recent work on n=157 lherzolitic clinopyroxene (Cpx) xenocrysts from the Victor mine reveals profound major- and trace-element (re)fertilization of the deepest 1/3rd of the central Superior craton lithosphere. For example, Cpx Mg/(Mg+Fe) of 0.93 in shallow peridotite decreases across a steep gradient to Mg/(Mg+Fe) of 0.89 at depths of 4.2 to 5.6 GPa. We document marked compositional gradients over a similar depth range for certain minor (Ti, Mn, Ni) and trace elements (LREE and HREE) and attribute the gradients to chromatographic and/or crystal-chemical fractionation effects. We carefully categorized the Victor cpx xenocrysts in nine depth-composition classes and determined Pb-isotope ratios for representative grains from each class in a bold experiment aimed at capturing geochronological data from mantle Cpx. A resultant 207Pb/206Pb secondary isochron array at ~ 1075 Ma identifies craton-scale events related to the Mid-Continent Rift as the source of fluids and/or melts that (re)fertilized the central Superior craton at depth, some 355 Ma prior to diamond growth. Coordinated, systematic major- and trace-element relationships in clinopyroxene permit compositional discrimination of mantle (re)fertilization at ~1075 Ma from fluid-metasomatism attending diamond growth at ~ 720 Ma. Roughly 10% of the clinopyroxene xenocrysts analyzed in this work exhibit diamond-associated compositions.
DS2000-0856
2000
Sarkar, D.Saul, J., Kumar, M.R., Sarkar, D.Lithospheric and upper mantle structure of Indian Shield, from teleseismic receiver functions.Geophysical Research Letters, Vol. 27, No. 16, Aug. 15, pp.2357-60.IndiaCraton, Geophysics - seismics
DS2003-1212
2003
Sarkar, D.Sarkar, D., Kumar, M.R., Saul, J., Kind, R., Raju, P.S., Chadha, R.K., ShuklaA receiver function perspective of the Dharwar craton ( India) crustal structureGeophysical Journal International, No. 154, 1, pp. 205-211.IndiaBlank
DS200412-1731
2003
Sarkar, D.Sarkar, D., Kumar, M.R., Saul, J., Kind, R., Raju, P.S., Chadha, R.K., Shukla, A.K.A receiver function perspective of the Dharwar craton ( India) crustal structure.Geophysical Journal International, No. 154, 1, pp. 205-211.IndiaGeophysics - seismics
DS201112-0168
2010
Sarkar, D.Chandrakala, K., Pandey, O.P., Mall, D.M., Sarkar, D.Seismic signatures of a Proterozoic thermal plume below southwestern part of the Cuddapah Basin, Dharwar craton.Journal of the Geological Society of India, Vol. 76, 6, pp.565-572.IndiaGeophysics - seismics
DS201112-0169
2010
Sarkar, D.Chandrakala, K., Pandey, O.P., Mall, D.M., Sarkar, D.Seismic signatures of a Proterozoic thermal plume below southwestern part of the Cuddapah basin, Dharwar craton.Journal of the Geological Society of India, Vol. 76, pp. 565-572.India, Andhra PradeshGeophysics - seismics kimberlite magmatism
DS201806-1242
2018
Sarkar, D.Ravi Kumar, M., Singh, A., Bhaskar Rao, Y.J., Srijayanthi, G., Satyanarayana, H.V., Sarkar, D.Vestiges of Precambrian subduction in the south Indian shield? - A seismological perspective.Tectonophysics, Vol. 740-741, pp. 27-41.Indiageophysics - seismic

Abstract: Investigation of large scale suture zones in old continental interiors offers insights into the evolution of continents. The Dharwar Craton (DC) and the Southern Granulite Terrain(SGT) of the Indian shield represent large segments of Precambrian middle to lower crust and preserve a geological record spanning from Mesoarchean to Cambrian. This study illuminates the deep structure of the Palghat-Cauvery Shear Zone System (PCSS) and the Palghat-Cauvery Suture Zone (PCSZ) that comprise crustal-scale structures related to multiple episodes of orogeny, crust formation and reworking. We utilize here 3202 high quality P-receiver functions computed using new data from a 23 station seismic network operated by us. Results show a thick (>38?km) mafic (Poisson's ratio >0.25) crust beneath the SGT. The change in crustal thickness is gradual, with a shallower Moho towards the south of PCSZ. We found little evidence for drastic changes in crustal thickness across prominent shear zones like the PCSZ and Moyar-Bhavani. Few seismic stations located along these boundaries have shown evidence for dipping reflectors around 8-20?km depth, with strikes matching well with the trends of surface geological sutures. We opine that these suture zones do not show indications of a terrane boundary. However, a drastic change in the crustal thickness is observed around the prograde metamorphic transition zone or broadly, the "Fermor line", which separates rocks of Chanockitic (Orthopyroxene bearing granitoid) and non-Charnockitic (Orthopyroxene-free granitoid) mineral assemblage, further north beneath the DC. We suggest that thicknening of crust north of Moyar-Attur Shear Zone (MASZ) and around Fermor line is related to subduction processes operative during the Precambrian.
DS201808-1761
2018
Sarkar, D.Kumar, M.R., Singh, A., Bhaskar Rao, Y.J., Srijayanthi, G., Satyanarayana, H.V., Sarkar, D.Vestiges of Precambrian subduction in the south Indian shield? - a seismological perspective.Tectonophysics, Vol. 740-741, pp. 27-41.Indiageophysics - seismic

Abstract: Investigation of large scale suture zones in old continental interiors offers insights into the evolution of continents. The Dharwar Craton (DC) and the Southern Granulite Terrain(SGT) of the Indian shield represent large segments of Precambrian middle to lower crust and preserve a geological record spanning from Mesoarchean to Cambrian. This study illuminates the deep structure of the Palghat-Cauvery Shear Zone System (PCSS) and the Palghat-Cauvery Suture Zone (PCSZ) that comprise crustal-scale structures related to multiple episodes of orogeny, crust formation and reworking. We utilize here 3202 high quality P-receiver functions computed using new data from a 23 station seismic network operated by us. Results show a thick (>38?km) mafic (Poisson's ratio >0.25) crust beneath the SGT. The change in crustal thickness is gradual, with a shallower Moho towards the south of PCSZ. We found little evidence for drastic changes in crustal thickness across prominent shear zones like the PCSZ and Moyar-Bhavani. Few seismic stations located along these boundaries have shown evidence for dipping reflectors around 8-20?km depth, with strikes matching well with the trends of surface geological sutures. We opine that these suture zones do not show indications of a terrane boundary. However, a drastic change in the crustal thickness is observed around the prograde metamorphic transition zone or broadly, the “Fermor line”, which separates rocks of Chanockitic (Orthopyroxene bearing granitoid) and non-Charnockitic (Orthopyroxene-free granitoid) mineral assemblage, further north beneath the DC. We suggest that thicknening of crust north of Moyar-Attur Shear Zone (MASZ) and around Fermor line is related to subduction processes operative during the Precambrian.
DS2000-0637
2000
Sarkar, S.Mazumder, R., Bose, P.K., Sarkar, S.A commentary on the tectono sedimentary record of the pre 2.0 Ga continental growth of India vis a vis ...Journal of African Earth Sciences, Vol. 30, No. 2, Feb. pp. 201-18.IndiaGondwana Afro-India supercontinent, Tectonics
DS2000-0638
2000
Sarkar, S.Mazumder, R., Bose, P.K., Sarkar, S.A commentary of the tecton-sedimentary record of pre 2.0 Ga continental growth of India..vis a vis pre-Journal of African Earth Sciences, Vol. 30, No. 2, pp. 201-17.IndiaTectonics - Gondwana Afro-Indian supercontinent
DS2003-0552
2003
Sarkar, S.Harijan, N., Sen, A.K., Sarkar, S., Das, J.D., Kanungo, D.P.Geomorphotectonic around the Sung Valley carbonatite complex, Shillong PlateauGeological Society of India Journal, Vol. 62, 1, pp. 103-109.IndiaCarbonatite
DS2003-0553
2003
Sarkar, S.Harijan, N., Sen, A.K., Sarkar, S., Das, J.D., Kanungo, D.P.Geomorphotectonics around the Sung Valley carbonatite Complex Shillong Plateau NEJournal of the Geological Society of India, Vol. 62, 1, July, pp. 103-109.India, northeastCarbonatite
DS200412-0791
2003
Sarkar, S.Harijan, N., Sen, A.K., Sarkar, S., Das, J.D., Kanungo, D.P.Geomorphotectonics around the Sung Valley carbonatite Complex Shillong Plateau NE India: a remote sensing and GIS approach.Journal of the Geological Society of India, Vol. 62, 1, July, pp. 103-109.IndiaTectonics Carbonatites
DS200812-0323
2008
Sarkar, S.Eriksson, P.G., Banerjee, S., Nelson, D.R., Rigby, M.J., Catuneanu, O., Sarkar, S., Roberts, R.J., Ruban, Mtimkulu, RajuA Kaapvaal Craton debate: nucleus of an early small supercontinent or affected by an enhanced accretion event?Gondwana Research, In press available, 82p.Africa, South AfricaSupercontinents
DS201412-0900
2014
Sarkar, S.Sunder Raju, P.V., Eriksson, P.G., Catuneanu, O., Sarkar, S., Banerjee, S.A review of the inferred geodynamic evolution of the Dharwar craton over the ca.3.5-2.5 Ga period, and possible implications for global tectonics.Canadian Journal of Earth Sciences, Vol. 51, 3, pp. 312-325.IndiaTectonics
DS201511-1875
2015
Sarkar, S.Saha, L., Frei, D., Gerdes, A., Pat, J.K., Sarkar, S., Patole, V., Bhandari, A., Nasipuri, P.Crustal geodynamics from the Archean Bundelk hand craton, India: constraints from zircon U-Pb-Hf isotope studies.Geological Magazine, Rapid communication Oct. 14p.IndiaTectonics, geochronology

Abstract: A comprehensive study based on U-Pb and Hf isotope analyses of zircons from gneisses has been conducted along the western part (Babina area) of the E–W-trending Bundelkhand Tectonic Zone in the central part of the Archaean Bundelkhand Craton. 207Pb-206Pb zircon ages and Hf isotopic data indicate the existence of a felsic crust at ~ 3.59 Ga, followed by a second tectonothermal event at ~ 3.44 Ga, leading to calc-alkaline magmatism and subsequent crustal growth. The study hence suggests that crust formation in the Bundelkhand Craton occurred in a similar time-frame to that recorded from the Singhbhum and Bastar cratons of the North Indian Shield.
DS201602-0234
2016
Sarkar, S.Saha, L., Frei, D., Gerdes, A., Pati, J.K., Sarkar, S., Patole, V., Bhandari, A., Nasipuri, P.Crustal geodynamics from the Archean Bundelk hand Craton, India: constraints from zircon U-Pb-Hf isotope studies.Geological Magazine, Vol. 153, 1, pp. 179-192.IndiaGeochronology, tectonics

Abstract: A comprehensive study based on U-Pb and Hf isotope analyses of zircons from gneisses has been conducted along the western part (Babina area) of the E-W-trending Bundelkhand Tectonic Zone in the central part of the Archaean Bundelkhand Craton. 207Pb-206Pb zircon ages and Hf isotopic data indicate the existence of a felsic crust at ~ 3.59 Ga, followed by a second tectonothermal event at ~ 3.44 Ga, leading to calc-alkaline magmatism and subsequent crustal growth. The study hence suggests that crust formation in the Bundelkhand Craton occurred in a similar time-frame to that recorded from the Singhbhum and Bastar cratons of the North Indian Shield.
DS202112-1943
2021
Sarkar, S.Sarkar, S., Giuliani, A., Ghosh, S., Phillips, D.Petrogenesis of coeval lamproites and kimberlites from the Wajrakarur field, southern India: new insights from olivine compositions.Lithos, Vol. 406-407, 106524 13p. PdfIndiadeposit - Wajrakarur

Abstract: Olivine is one of the most abundant phases in kimberlites and cratonic lamproites, where it occurs as mantle-derived xenocrysts and magmatic phenocrysts or rims overgrowing xenocrystic cores, indicating its prevalence throughout most of the crystallisation sequence of these magmas. Thus, olivine can provide valuable insights into kimberlite and lamproite petrogenesis. Here, we present a detailed study of olivine compositional zoning in two lamproites (P2 and P12) of the Mesoproterozoic Wajrakarur kimberlite-lamproite field in southern India and use these data to propose a genetic link between lamproites and kimberlites in the region. Olivine macrocrysts (i.e., anhedral grains >1 mm) from the P2 and P12 intrusions are strongly zoned. Comparisons with olivine from mantle xenoliths worldwide demonstrate that the cores of olivine macrocrysts are xenocrysts derived from disaggregated mantle wall-rocks. The internal zones and overgrowth rims of olivine macrocrysts and the cores of olivine phenocrysts from P2 and P12 contain magmatic Mg-chromite and Ti-magnetite inclusions and hence crystallized from the host lamproite melt. These magmatic olivine zones show increasing Mg# (molar Mg/(Mg + Fe2+)), CaO and MnO contents with decreasing NiO. This reverse differentiation trend appears to be a characteristic feature of olivine in lamproites from the Wajrakarur field. To evaluate potential petrogenetic links between coeval lamproites and kimberlites from Wajrakarur, the composition of olivine xenocrysts (i.e., macrocryst cores) was compared with that of early crystallized olivine in P2, P12 and previously studied kimberlites and lamproites. The average Mg# of olivine macrocryst cores is directly correlated with the average Mg# of magmatic olivine in lamproites and kimberlites from Wajrakarur. Coupled with their indistinguishable Sr-Nd-Hf isotope compositions, these data suggest derivation of the Wajrakarur lamproites and kimberlites from a common source, The more Fe-rich composition of liquidus olivine in the Wajrakarur lamproites compared to coeval kimberlites suggests a higher degree of assimilation of metasomatised Fe-richer lithospheric mantle by the lamproites and provides a plausible explanation for the different petrological features of the Wajrakarur lamproites and kimberlites Our results suggest that cratonic lamproites can have a remarkably similar petrogenetic history to kimberlites.
DS1995-1660
1995
Sarkar, S.C.Sarkar, S.C., Dwivedy, K.K., Das, A.K.Rare earth deposits in India - an outline of their types, distribution, mineralogy geochemistry genesis.Global Tectonics and Metallogeny, Vol. 5, No. 1-2, Oct. pp. 53-61.IndiaCarbonatite, rare earth elements (REE)., Deposits -list
DS201808-1738
2017
Sarkar, S.C.Deb, M., Sarkar, S.C.Minerals and allied natural resources and their sustainable development. Principles, perspectives with emphasis on the Indian scenario. Detailed Book reviewSpringer Nature , book review in Mineralium Deposita diamonds mentioned p. 6-7. of reviewIndiadiamonds

Abstract: Nonrenewable natural resources - metallic and non-metallic minerals, industrial rocks and energy resources (both organic and inorganic), have been treated in a holistic manner in this book, including two important resources (soil and water), not commonly covered in most books on this topic. For the uninitiated reader, an introductory chapter looks into some basic definitions as well as nature and characteristics of mineral deposits followed by a chapter on the different crustal processes that produce the various ore deposits in the endogenous and exogenous environments. The strength of the book lies in its critical treatment of the genetic processes of the mineral deposits, their classification and the geodynamic context of metallogeny, and coverage of sustainable development of mineral deposits with special reference to various socio-economic as well as regulatory and environmental issues that face the Indian mining industry today. The text is punctuated with examples of Indian deposits, balanced with classical deposits around the world, to cater to the interests of Indian students and the international readership. This is a book for advanced undergraduate and post-graduate students of Geology, Environmental Sciences and Natural Resource Management.
DS200612-1224
2001
Sarkar, S.K.Sarkar, S.K., Mishra, B.K.Status and strategy of diamond exploration in the Bastar Craton, Chhattisgarh State.National Seminar on Exploration Survey, Geological Society of India Special Publication, No. 58, pp. 557-565.India, ChhattisgarhDiamond exploration - geochemistry, chromite
DS2002-0905
2002
Sarker, D.Kumar, M.R., Ramesh, D.S., Saul, J., Sarker, D., Kind, R.Crustal structure and upper mantle stratigraphy of the Arabian ShieldGeophysical Research Letters, Vol. 89, No. 8, April 15, pp. 83-Arabian Shield, North AfricaTectonics
DS1999-0625
1999
Sarker, G.Sarker, G., Abers, G.A.Lithospheric temperature estimates from seismic attentuation across range fronts in southern and central.Geology, Vol. 27, No. 5, May pp. 427-30.GlobalCraton, Tian Shan Mountains
DS1970-0405
1971
Sarkisyan, S.G.Sarkisyan, S.G., Pogorelov, B.S.Ultramafic Basement Rocks of the West Siberian PlateDoklady Academy of Sciences USSR EARTH SCI., Vol. 200, No. 1-6, PP. 74-76.RussiaKimberlite
DS1993-0855
1993
Sarlthev, I.K.Krjuchkov, A.I., Sarlthev, I.K.Some aspects of the evaluation of covered Yakutian diamond depositsDiamonds of Yakutia, pp. 113-114.Russia, YakutiaEvaluation
DS2001-1014
2001
Sarma, B.S.P.Sarma, B.S.P., Verma, B.K.Aeromagnetic lineaments, basement structure and kimberlite emplacement in Andhra Pradesh, India.Geophysical Research Letters, Vol. 28, No. 22, Nov. 15, pp. 4387-90.India, Andhra PradeshGeophysics - aeromagnetics
DS1997-0995
1997
Sarma, J.A.R.O.Sarma, J.A.R.O., Nangia, A., Dunitz, J.D.Even odder carbonsNature, Vol. 387, No. 6632, May 29, pp. 464-65.GlobalCarbon, Mineralogy
DS1950-0353
1957
Sarma, K.Sarma, K.A Preliminary Report on the Magnetic Survey for Locating Hidden Volcanic Pipes in the Panna Diamond Belt.India Geological Survey Report, (UNPUBL.)India, Madhya PradeshKimberlite, Geophysics
DS1950-0500
1959
Sarma, K.Sarma, K., Nandi, S.C.Report on the Magnetic and Electrical Surveys for Locating Additional Hidden Volcanic Pipes in the Panna Diamond Belt.India Geological Survey Report, (UNPUBL.)India, Panna, Madhya PradeshKimberlite, Geophysics
DS1960-0493
1964
Sarma, K.Sarma, K., Nandi, S.C.Magnetic and Electrical Surveys for Locating Additional Hidden Volcanic Pipes in the Panna Diamond Belt, Madhya Pradesh, India.International Geological Congress 22ND., PT. 2, PP. 90-106.India, Madhya PradeshKimberlite, Geophysics
DS1994-0865
1994
Sarma, K.J.Kameswara Rao, T., Sarma, K.J.A new occurrence of kimberlite near Kotakonda Mahboobnagar District, AndhraPradesh. #1Journal of the Geological Society of India, Vol. 43, January pp. 75-85.IndiaPetrology, Dyke -Kotakonda
DS1994-1439
1994
Sarma, K.J.Rao, T.K., Sarma, K.J.A new occurrence of kimberlite near Kotakonda, Mahboobhagar district, Andhra Pradesh.Journal Geological Society of India, Vol. 43, No. 1, January pp. 78-85.IndiaKimberlite
DS200612-1390
2006
Sarma, K.V.L.N.Subrahmanyam, V., Subrahmanyam, A.S., Murthy, K.S.R., Murty, G.P.S., Sarma, K.V.L.N., SuneetaRani, AnuradhaPrecambrian mega lineaments across the Indian sub continent - preliminary evidence from offshore magnetic data.Current Science, Vol. 90, 4, Feb. 25, pp. 578-581.IndiaTectonics, structures, geomagnetics, geophysics
DS2003-0691
2003
Sarma, P.K.Karmalkar, N.R., Sarma, P.K.Characterization and origin of sililic and alkali rich glasses in the upper mantle derivedCurrent Science, Vol. 85, 3, pp. 386-91.IndiaXenoliths
DS200412-0955
2003
Sarma, P.K.Karmalkar, N.R., Sarma, P.K.Characterization and origin of sililic and alkali rich glasses in the upper mantle derived spinel peridotite xenoliths from alkaCurrent Science, Vol. 85, 3, pp. 386-91.IndiaXenoliths
DS1986-0703
1986
Sarma, S.V.S.Sarma, S.V.S., Harinarayana, T., Venogopala, Krishna, C., SankerTellurics in the exploration of kimberlite pipes- an experimental studyCurrent Science, Vol. 55, No. 3, pp. 133-136IndiaWajrakarur, LattavaraM., Geophysics
DS1987-0648
1987
Sarma, S.V.S.Sarma, S.V.S., Harinarayana, T., Gopalakrishna, C.V.et al.Tellurics in the detection and delineation of lineament features In kimberlite areas, an experimental approachIntegrated Geophysical Exploration for Mineral Deposits, Baroda, Vol. 13, p. A30. (Abstract)IndiaGeophysics -Tellurics, Kimberlite
DS200612-1050
2006
Sarma, S.V.S.Patro, B.P.K., Nagarajan, N., Sarma, S.V.S.Crustal geoelectric structure and the focal depths of major stable continental region earthquakes in India.Current Science, Vol. 90, 1, Jan. 10, pp. 107-113..Asia, IndiaGeophysics - seismics, tectonics
DS200812-1007
2008
Sarma, S.V.S.Satry, R.S., Nagarajan, N., Sarma, S.V.S.Electrical imaging of deep crustal features of Kutch, India.Geophysical Journal International, Vol. 172, no. 3, March pp. 934-944.IndiaGeophysics - seismics
DS200912-0574
2009
Sarma, S.V.S.Patro, P.K., Sarma, S.V.S.Lithospheric electrical mapping of the Deccan Trap covered region of western India.Journal of Geophysical Research, Vol. 114, B01192IndiaDharwar Craton
DS1997-1139
1997
Sarma, V.A.K.Tardy, Y., Sarma, V.A.K.Petrology of laterites and tropical soilsBalkema, 500p. approx. $ 150.00Africa, Central Africa, West Africa, Ivory CoastBook - table of contents, Laterites
DS1994-0057
1994
Sarma, V.S.Apparao, A., Sastry, R.S., Sarma, V.S.Spectral IP studies buried scale models incorporating surface and volumepolarizationExploration Geophysics, Australian Bulletin, Vol. 25, No. 1, March pp. 31-38AustraliaGeophysics -IP, Models
DS202104-0597
2021
Sarma, V.S.Parashuramulu, V., Shankar, R., Sarma, V.S., Nagaraju, E., Babu, N.R.Baddeleyite Pb-Pb geochrnology and paleomagnetic poles for ~1.89-~1.86 Ga mafic intrusions from the Dharwar craton, India, and their paleogeographic implications.Tectonophysics, Vol. 805, 228789 18p. PdfIndiamagmatism

Abstract: We present new key paleomagnetic pole at 13°S, 152°E (k = 21, A95 = 7.8°) for recently identified 1864.4 ± 2.7 Ma (weighted mean age of four Pbsingle bondPb ages) mafic magmatic event, based on a detailed paleomagnetic study of dolerite dykes and sills intruding Archean basement rocks and Tadipatri formation of the Cuddapah basin, Dharwar craton respectively. The Pbsingle bondPb baddeleyite geochronology yields a crystallisation age of 1867.1 ± 1.0 Ma (MSWD = 1.02) for N77°E trending dyke in the southern region to Cuddapah basin. This new age obtained, confirms the presence of ~1864 Ma magmatic episode with a spatial extent of ~400 km in the Eastern Dharwar craton, within the brief period of ~5 Ma. The paleomagnetic results in these dykes revealed reverse polarity magnetisation direction with mean D = 107°, I = 24° (N = 13 sites, ?95 = 10°). Here, we also update the normal polarity magnetic directions on ~1.89 Ga swarm, and the corresponding paleopole situated at 21°N, 336°E (N = 79 sites, A95 = 3.6°). The paleoposition of India is constrained around the equator during ~1.89-1.86 Ga time. The paleogeographic reconstructions were also been attempted at ~1.89 Ga and ~ 1.86 Ga with available key poles from other cratons, indicates the possibility of single plume acting as a source for two distinguishable radial emplacement of mafic dyke swarms across India (Dharwar and Bastar craton) and Western Australia (Yilgarn craton) within a time span of ~35 Ma. The individual movement of India, Baltica and Siberia with a drift rate of ~5.55 cm/yr towards the south, whereas Amazonia craton has moved rapidly to the north (~24.9 cm/yr), do not suggest the amalgamation of a supercontinent (Columbia/ Nuna) during ~1.88-1.86 Ga time.
DS1995-0819
1995
Sarmiento, G.A.Hoorn, C., Guerrero, J., Sarmiento, G.A., Lorente, M.A.Andean tectonics as a cause for changing drainage patterns in Miocene northern South America.Geology, Vol. 23, No. 3, March pp. 237-240.Guyana Shield, VenezuelaTectonics, Geomorphology
DS1993-1375
1993
Sarmiento, J.L.Sarmiento, J.L.Atmospheric CO2 stalled...carbon cycleNature, Vol. 365, October 21, pp. 697-698.GlobalCarbon, Carbon dioxide
DS1993-1376
1993
Sarmineto, J.L.Sarmineto, J.L.Carbon cycle: atmospheric CO2 stalledNature, Vol. 365, No. 6448, October 21, p. 697MantleCarbon cycle
DS201502-0082
2014
Sarocchi, D.Moreno Chavez, G., Sarocchi, D., Arce Santana, E., Borselli, L.Using Kinect to analyze pebble to block-sized clasts in sedimentology.Computers & Geosciences, Vol. 72, pp. 18-32.TechnologyNot specific to diamonds
DS1990-0304
1990
Sarre, R.D.Chancey, C.C., Sarre, R.D.Analysis of new surface sampling technique for unconsolidated sandpopulationsMathematical Geology, Vol. 22, No. 7, pp. 825-835GlobalGeostatistics, Sampling -sand
DS1960-0092
1960
Sarsadskikh, N.N.Sarsadskikh, N.N., Rovsha, V.S.Genetic Conditions of the Diamond and Mineral Satellites In the Kimberlites of Yakutia.Reports of The All Union Mineralogical Society, Moscow., SER. 2, No. 4, PP. 392-399. U.S. JOINT PUBLN. RESEARCH SERVIRussiaBlank
DS1960-0093
1960
Sarsadskikh, N.N.Sarsadskikh, N.N., Rovsha, V.S., Blagulkina, V.A.Minerals of Inclusions of Pyrope Peridotites in the Kimberlites of the Daldyn-alakit Diamond Bearing Region.Vsegei, No. 40, PP. 37-55.RussiaBlank
DS1960-0217
1962
Sarsadskikh, N.N.Blagulkina, V.A., Rosha, V.S., Sarsadskikh, N.N.The Mineralogy of Rocks Related to KimberlitesZap. Vses. Miner. Obshch., PT. 91, No. 2, PP. 236-241.RussiaBlank
DS1960-0742
1966
Sarsadskikh, N.N.Sarsadskikh, N.N., Blagulkina, V.A., Silin, YU. I.The Absolute Age of the Yakutian KimberlitesDoklady Academy of Sciences Nauk SSSR, Vol. 168, No. 2, PP. 420-423., RussiaBlank
DS1960-0743
1966
Sarsadskikh, N.N.Sarsadskikh, N.N., Rovsha, V.S.The Conditions of Formation of the Minerals that Accompany Diamond in the Kimberlites of Yakutia.Zap. Vses. Miner. Obshch., PT. 89, No. 4, PP. 392-399.RussiaBlank
DS1960-1205
1969
Sarsadskikh, N.N.Sarsadskikh, N.N.Mineral Paragenesis of the Ultrabasic Rock Inclusions in The Siberian Kimberlites.In: Vses. Petrograf, Sovesh. Mater., PT. 4, PP. 502-503.RussiaBlank
DS1960-1206
1969
Sarsadskikh, N.N.Sarsadskikh, N.N., Blagulkina, V.A.Petrographic and Petrogenic Differences between the Kimberlites and Rocks Similar to Them in Certain Features.Zap. Vses. Miner. Obshch., PT. 98, No. 4, PP. 415-421.RussiaBlank
DS1981-0359
1981
Sarsadskikh, N.N.Sarsadskikh, N.N.Using the Density of Pyrope As Prospecting Criteria for Predicting Diamond Deposits.Izd. Nauka Leningr. Otd. Ussr, Mineralogischeskiye Kriterii, PP. 150-156.RussiaProspecting, Diamond Genesis
DS201904-0738
2019
Sartori, G.Galli, A., Grassi, D., Sartori, G., Gianola, O., Burg, J-P., Schmidt, M.W.Jurassic carbonatite and alkaline magmatism in the Ivrea zone ( European Alps) related to the breakup of Pangea.Geology, Vol. 47, 3, pp. 199-202..Europecarbonatite

Abstract: We report on pipe-like bodies and dikes of carbonate rocks related to sodic alkaline intrusions and amphibole mantle peridotites in the Ivrea zone (European Southern Alps). The carbonate rocks have bulk trace-element concentrations typical of low-rare earth element carbonatites interpreted as cumulates of carbonatite melts. Faintly zoned zircons from these carbonate rocks contain calcite inclusions and have trace-element compositions akin to those of carbonatite zircons. Laser ablation-inductively coupled plasma-mass spectrometry U-Pb zircon dating yields concordant ages of 187 ± 2.4 and 192 ± 2.5 Ma, coeval with sodic alkaline magmatism in the Ivrea zone. Cross-cutting relations, ages, as well as bulk and zircon geochemistry indicate that the carbonate rocks are carbonatites, the first ones reported from the Alps. Carbonatites and alkaline intrusions are comagmatic and were emplaced in the nascent passive margin of Adria during the Early Jurassic breakup of Pangea. Extension caused partial melting of amphibole-rich mantle domains, yielding sodic alkaline magmas whose fractionation led to carbonatite-silicate melt immiscibility. Similar occurrences in other rifts suggest that small-scale, sodic and CO2-rich alkaline magmatism is a typical result of extension and decompression-driven reactivation of amphibole-bearing lithospheric mantle during passive continental breakup and the evolution of magma-poor rifts.
DS200812-0631
2007
Saruna, A.Lang, A.R., Bulanova, G.P., Fisher, D., Fukert, S., Saruna, A.Defects in a mixed habit Yakutian diamond: studies by optical and cathodluminescence microscopy, infrared absorption, Raman Scattering and photoluminesence spectJournal of Crystal Growth, Vol. 309, 2, pp. 170-180.TechnologySpectroscopy
DS2001-1015
2001
Saruwatari, K.Saruwatari, K., Ji, S., Long, C., Saisbury, M.H.Seismic anisotropy of mantle xenoliths and constraints on upper mantle structure beneath southern Cordillera.Tectonophysics, Vol. 339, No. 3-4, pp. 403-26.Mantle, British ColumbiaGeophysics - seismics, Xenoliths
DS2003-0656
2003
Saruwateri, K.Ji, S., Saruwateri, K., Mainproce, D., Wirth, R., Xu, Z., Xia, B.Microstructures, petrofabrics and seismic properties of ultra high pressure eclogitesTectonophysics, Vol. 370, 1-4, pp. 49-76.ChinaGeophysics - seismics, UHP, subduction
DS200412-0915
2003
Saruwateri, K.Ji, S., Saruwateri, K., Mainproce, D., Wirth, R., Xu, Z., Xia, B.Microstructures, petrofabrics and seismic properties of ultra high pressure eclogites from Sulu region, China: implications forTectonophysics, Vol. 370, 1-4, pp. 49-76.ChinaGeophysics - seismics UHP, subduction
DS202107-1101
2018
Sarwate, N.K.Guha, A., Rani, K., Varma, C.B., Sarwate, N.K., Sharma, N., Mukherjee, A., Kumar, K.V., Pal, S.K., Saw, A.K., Jha, S.K.Identification of potential zones for kimberlite exploration - an Earth observation approach. ChhatarpurThe International Achives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol. XLII-5 12p. PdfIndia, Madhya PradeshASTER, lineament

Abstract: In the present study, we have prepared the thematic evidence layers for identifying the potential zones of kimberlite emplacement in parts of Chhatarpur district, Madhya Pradesh. These thematic layers or evidence layers are geological structure, alteration zones, lineament density, surface alteration and geomorphic anomaly and these layers are prepared from the remote sensing data. As orientation of the geological structures (i.e fault system) and their density have the major role in the emplacement of kimberlite; both of these evidence layers are integrated using "AND" Boolean Logical Operator. On the other hand, two evidential layers regarded as the proxy to indicate the "surface expressions on kimberlite (i.e. alteration zones and geomorphic anomaly) are combined using "OR" operator as either of these two surface expression is indicative of kimberlite. Consequently, conjugate evidence layers on the surface expressions of kimberlite are integrated with the causative evidence layers of kimberlite emplacement using "AND" operator to identify the potential zones of diamond occurrences. Potential zones of kimberlite are overlaid on the residual gravity anomaly map derived from space-based gravity model of European Improved Gravity of Earth by New Technique (EIGEN6C4) to relate potential zones of kimberlite with the similar structural alignment (delineated in the residual gravity map) of known occurrence of kimberlite. We also have carried out indicator mineral survey around these potential zones and some of the kimberlite specific indicator minerals are identified in the stream sediments within these potential zones.
DS1989-1341
1989
Sarychev, I.K.Sarychev, I.K.Pecularities of geological structure and process of formation of one Of the kimberlite pipes of the Alakit fieldSoviet Geology and Geophysics, Vol. 29, No. 11, pp. 89-97RussiaStructure, Tectonics
DS1990-1302
1990
Sarychev, I.K.Sarychev, I.K., Talaeva, T.P.Formalized geological -structural model of the Daldyn-Alakit Diamond bearing regionSoviet Geology and Geophysics, Vol. 31, No. 5, pp. 132-136RussiaStructure, Daldyn-Alakit
DS1992-1327
1992
Sarychev, I.K.Sarychev, I.K., Fomin, A.S.A typical geological genetic model of kimberlite pipe from the Daldyn-Alakit region.Russian Geology and Geophysics formerly Soviet Geology and Geophysics, Vol. 33, No. 1, pp. 107-113.Russia, Commonwealth of Independent States (CIS), YakutiaKimberlite genesis, Model
DS1995-1329
1995
Sarychev, I.K.Nasurdinov, T.G., Sarychev, I.K., Fomin, A.S.The features of the geological structure of the Upper Horizons of the Yubileinaya pipe.Proceedings of the Sixth International Kimberlite Conference Almazy Rossii Sakha abstract, p. 25.Russia, YakutiaStructure, Deposit -Jubilee
DS202104-0571
2021
Saryg-ool, B. Yu.Dobretsov, N.L., Zhmodik, S.M., Lazareva, E.V., Bryanskaya, A.V., Ponomarchuk, V.A., Saryg-ool, B. Yu., Kirichenko, I.S., Tolstov, A.V., Karmanov, N.S.Structural and morphological features of the participation of microorganisms in the formation of Nb-REE-rich ores of the Tomtor field, Russia.Doklady Earth Sciences, Vol. 496, pp. 135-138. Russiadeposit - Tomtor

Abstract: Data indicating the important role of microorganisms in the redistribution of REEs in the weathering crust and the decisive role in the concentration of REEs during the formation of ores in the upper ore horizon of the Tomtor field are obtained. The uptake of REEs was carried out by the community of microorganisms, such as phototrophs, methanogens, methanotrophs, and proteobacteria, which form the basis of the microbiocenosis for this paleoecosystem. The isotopic composition of C carbonates in all samples studied with fossilized microorganisms corresponds to the biogenic one, and the isotopic composition ?18?SMOW (from 7 to 20‰) indicates the endogenous (hydrothermal) and, to a lesser extent, exogenous nature of the solutions. The low (87Sr/86Sr)I values of carbonates (~0.7036-0.7042) exclude the participation of seawater.
DS1981-0175
1981
Sas, Z.Gates, A.H., Sas, Z., Esterle, J., Carson, M., Pacific Exploration Co.El 477 Terowie South Australia Progress Reports from 16/8/79South Australia Open File., No. E3612, 104P. UNPUBL.Australia, South AustraliaGeochemistry, Prospecting, Stream Sediment Sampling, Rock Chip
DS1981-0360
1981
Sas, Z.Sas, Z., Esterle, J., Gates, T. , Western queen (sa) pty. ltd.El 779 Lobethal Sa, Progress Reports from 12/4/81 to September 1981.South Australia Open File., No. E4098, 44P. UNPUBL.Australia, South AustraliaGechemistry, Prospecting, Stream Sediment Sampling, Diamonds
DS1981-0361
1981
Sas, Z.Sas, Z., Gates, A.H., Gem ex and min. ltd., CULTUS PACIFIC NL.El 504, El 505, Mt. Christie, Muckanippie, Lake Barry (tarcoSouth Australia Open File., No. E3596, E3597, E3598, 186P. UNPUBL.Australia, South AustraliaGeochemistry, Stream Sediment Sampling, Heavy Minerals
DS1981-0362
1981
Sas, Z.Sas, Z., Gates, A.H., Gem ex and min. ltd., WESTERN QUEEN (SA).El 760 Canegrass and El 763 Nilpinna, South Australia, Progress and Final Reports.South Australia Open File., No. E4061, 22P. UNPUBL.Australia, South AustraliaLiterature Review, Diamonds, Stratigraphy, Artesian Basin
DS1981-0363
1981
Sas, Z.Sas, Z., Gates, T., Pacific exploration pty. ltd.El 493 Echunga District South Australia Progress Reports 15/9/79 to 15/9/81.South Australia Open File., No. E3563, 129P. UNPUBL.Australia, South AustraliaGeophysics, Geochemistry, Prospecting, Airborne Magnetics
DS1992-1328
1992
Sasada, T.Sasada, T., Hyagon, H.Noble gases in carbonatites from Canada and BrasilProceedings of the 29th International Geological Congress. Held Japan August 1992, Vol. 1, abstract p. 183Quebec, BrazilOka, Carbonatite
DS1997-0996
1997
Sasada, T.Sasada, T., Hiyagon, H., Bell, K., Erihara, M.Mantle derived noble gases in carbonatitesGeochimica et Cosmochimica Acta, Vol. 61, No. 19, Oct. pp. 4219-28.Brazil, Ontario, QuebecCarbonatite, Jacupirigna, Tapira, Borden, Oka, Prairie, Poohbah
DS1981-0364
1981
Sasaki, E.Sato, K., Sasaki, E.Application of Interference Contrast Microscopy to Identify coated Diamonds.Journal of GEMMOLOGICAL SOCIETY of JAPAN., Vol. 8, No. 1-8, PP.GlobalBlank
DS1983-0556
1983
Sasaki, S.Sasaki, S., Prewitt, C.T., Liebermann, R.C.The Crystal Structure of Cageo3 Perovskite and the Crystal Chemistry of the Gdfeo3 Type Perovskites.American Mineralogist., Vol. 68, PP. 1189-1198.GlobalMineralogy
DS200412-0590
2004
sasaki, Y.Fujino, K., sasaki, Y., Komori, T., Ogawa, H., Miyajima, N., Sata, N., Yagi, T.Approach to the mineralogy of the lower mantle by a combined method of a laser heated diamond anvil cell experiment and analyticPhysics of the Earth and Planetary Interiors, Vol. 143-144, pp. 215-221.MantleMineralogy - experimental
DS2002-1402
2002
Sashdharan, K.Sashdharan, K., Mohanty, A.K., Gupta, A.A note on the diamond incidence in Wairagargh area, Garchiroli district MaharashtraJournal of Geological Society of India, Vol. 59,No.3,pp. 265-8.IndiaMineralogy
DS2002-1403
2002
Sashidharan, K.Sashidharan, K.Detailed search for kimberlite/lamproite in parts of Chandrapur and Garhchiroli Districts, Maharashtra.Records of the Geological Survey of India, Vol. 135, 6, 2000-2001, pp.48-49.India, MaharashtraGeochemistry
DS2002-1404
2002
Sashidharan, K.Sashidharan, K., Mohanty, A.K., Gupta, A.A note on the diamond incidence in Wairagargh area, Garchiroli district Maharashtra.Journal of the Geological Society of India, Vol. 59, March, pp. 265-268.IndiaDiamond morphology
DS2002-1405
2002
Sashidharan, K.Sashidharan, K., Mohanty, A.K., Gupta, A.A note on the diamond incidence in Wairagarh area, Garhchiroli district, MaharashtraJournal Geological Society of India, Vol. 59, pp. 265-8.IndiaDiamond occurrence
DS2002-1406
2002
Sashidharan, K.Sashidharan, K., Mohanty, A.K., Gupta, A.A note on diamond incidence in Wairagarh area, Garchiroli district, MaharashtraJournal of the Geological Society of India, Vol. 59, March pp. 265-268.India, MaharashtraConglomerates
DS200412-1732
2002
Sashidharan, K.Sashidharan, K.Detailed search for kimberlite/lamproite in parts of Chandrapur and Garhchiroli Districts, Maharashtra.Records of the Geological Survey of India, Vol. 135, 6, 2000-2001, pp.48-49.India, MaharashtraGeochemistry
DS200412-1733
2002
Sashidharan, K.Sashidharan, K., Mohanty, A.K., Gupta, A.A note on diamond incidence in Wairagarh area, Garchiroli district, Maharashtra.Journal of the Geological Society of India, Vol. 59, March pp. 265-268.India, MaharashtraConglomerates
DS200612-1225
2001
Sashidharan, K.Sashidharan, K., Ganvir, D.V., Mohanty, A.K.Search for kimberlites and lamproites in the western part of the Bastar Craton, Maharashtra.National Seminar on Exploration Survey, Geological Society of India Special Publication, No. 58, pp. 629-634.India, MaharashtraDiamond exploration - geochemistry comparison Monastery
DS201502-0076
2014
Sasinkova, V.Majka, J., Rosen, A., Janak, M., Froitzheim, N., Klonowska, I., Manecki, M., Sasinkova, V., Yoshida, K.Microdiamond discovered in the Seve Nappe ( Scandinavian Caledonides) and its exhumation by the "vacuum-cleaner" mechanism.Geology, Vol. 42, 12, pp. 1107-1110.Europe, SwedenSubduction, microdiamond
DS201504-0203
2015
Sasinkova, V.Janak, M., Froitzheim, N., Yoshida, K., Sasinkova, V., Nosko, M., Kobayashi,T., Hirajima, T., Vrabec, M.Diamond in metasedimentary crustal rocks from Pohorje, eastern Alps: a window to deep continental subductionJournal of Metamorphic Geology, Vol. 33, 5, pp. 495-512.Europe, SloveniaSubduction
DS201505-0237
2014
Sasinkova, V.Majka, J., Rosen, A., Janak, M., Froitzheim, N., Klonowska, I., Maneck, M., Sasinkova, V., Yoshida, K.Microdiamond discovered in the Seve Nappe (Scandinavian Caledonides) and its exhumation by the "vacuum-cleaner" mechanism.Geology, Vol. 42, 12, pp. 1107-110.EuropeMicrodiamonds
DS201602-0230
2016
Sasinkova, V.Petrik, I., Janak, M., Froitzheim, N., Georgiev, N., Yoshida, K., Sasinkova, V., Konecny, P., Milovska, S.Triassic to Early Jurassic (c.200 Ma) UHP metamorphism in the Central Rhodopes: evidence from U-Pb-Th dating of monazite in diamond bearing gneiss from Chelelpare, Bulgaria.Journal of Metamorphic Geology, in press available, 44p.Europe, BulgariaGneiss - diamonds

Abstract: Evidence for ultrahigh-pressure metamorphism (UHPM) in the Rhodope Metamorphic Complex comes from occurrence of diamond in pelitic gneisses, variably overprinted by granulite facies metamorphism, known from several areas of the Rhodopes. However, tectonic setting and timing of UHPM are not interpreted unanimously. Linking age to metamorphic stage is a prerequisite for reconstruction of these processes. Here we use monazite in diamond-bearing gneiss from Chepelare (Bulgaria) to date the diamond-forming UHPM event in the Central Rhodopes. The diamond-bearing gneiss comes from a strongly deformed, lithologically heterogeneous zone (Chepelare Mélange) sandwiched between two migmatized orthogneiss units, known as Arda-I and Arda-II. Diamond, identified by Raman micro-spectroscopy, shows the characteristic band mostly centred between 1332 and 1330 cm?1. The microdiamond occurs as single grains or polyphase diamond + carbonate inclusions, rarely with CO2. Thermodynamic modelling shows that garnet was stable at UHP conditions of 3.5-4.6 GPa and 700-800 °C, in the stability field of diamond, and was re-equilibrated at granulite facies/partial melting conditions of 0.8-1.2 GPa and 750-800 °C. The texture of monazite shows older central parts and extensive younger domains which formed due to metasomatic replacement in solid residue and/or overgrowth in melt domains. The monazite core compositions, with distinctly lower Y, Th and U contents, suggest its formation in equilibrium with garnet. The U-Th-Pb dating of monazite using electron microprobe analysis yielded a c. 200 Ma age for the older cores with low Th, Y, U and high La/Nd ratio, and a c. 160 Ma age for the dominant younger monazite enriched in Th, Y, U and HREE. The older age of around 200 Ma is interpreted as the timing of UHPM whereas the younger age of around 160 Ma as granulite facies/partial melting overprint. Our results suggest that UHPM occurred in Late Triassic to Early Jurassic time, in the framework of collision and subduction of continental crust after the closure of Palaeotethys.
DS201604-0621
2016
Sasinkova, V.Petrik, I., Janak, M., Froitzheim, N., Georgiev, N., Yoshida, K., Sasinkova, V., Konecny, P., Milovska, S.Triassic to Early Jurassic ( c. 200Ma) UHP metamorphism in the Central Rhodopes: evidence from U-Pb dating of monazite in diamond bearing gneiss from Chepelare ( Bulgaria).Journal of Metamorphic Geology, Vol. 34, 3, pp. 265-291.Europe, BulgariaUHP diamond bearing gneiss
DS201606-1105
2016
Sasinkova, V.Petrik, I., Janak, M., Froitzheim, N., Georgiev, N., Yoshida, K., Sasinkova, V., Konecny, P., Milovska, S.Triassic to Early Jurassic ( c. 200Ma) UHP metamorphism in the central Rhodopes: evidence from U-Pb-Th dating of monazite in diamond bearing gneiss from Chepelare Bulgaria.Journal of Metamorphic Geology, Vol. 34, 3, pp. 265-291.Europe, BulgariaDiamonds in gneiss
DS201702-0221
2017
sasinkova, V.Klonowska, I., Janak, M., Majka, J., Petrik, I., Froitzheim, N., Gee, D.G., sasinkova, V.Microdiamond on Areskutan confirms regional UHP metamorphism in the Seve Nappe complex of the Scandinavian Caledonides.Journal of Metamorphic Geology, in press availableEurope, Sweden, NorwayUHP

Abstract: Metamorphic diamond in crustal rocks provides important information on the deep subduction of continental crust. Here we present a new occurrence of diamond within the Seve Nappe Complex of the Scandinavian Caledonides, on Åreskutan in Jämtland County, Sweden. Microdiamond is found in-situ as single and composite (diamond + carbonate) inclusions within garnet, in kyanite-bearing paragneisses. The rocks preserve the primary peak pressure assemblage of Ca,Mg-rich garnet + phengite + kyanite + rutile, with polycrystalline quartz surrounded by radial cracks indicating breakdown of coesite. Calculated P-T conditions for this stage are 830-840 °C and 4.1-4.2 GPa, in the diamond stability field. The ultrahigh-pressure (UHP) assemblage has been variably overprinted under granulite facies conditions of 850-860 °C and 1.0-1.1 GPa, leading to formation of Ca,Mg-poor garnet+biotite+ plagioclase+K-feldspar+sillimanite+ilmenite+quartz. This overprint was the result of nearly isothermal decompression, which is corroborated by Ti-in-quartz thermometry. Chemical Th-U-Pb dating of monazite yields ages between 445 and 435 Ma, which are interpreted to record post-UHP exhumation of the diamond-bearing rocks. The new discovery of microdiamond on Åreskutan, together with other evidence of ultrahigh-pressure metamorphism (UHPM) within gneisses, eclogites and peridotites elsewhere in the Seve Nappe Complex, provide compelling arguments for regional (at least 200 km along strike of the unit). UHPM of substantial parts of this far-travelled allochthon. The occurrence of UHPM in both rheologically weak (gneisses) and strong lithologies (eclogites, peridotites) speaks against the presence of large tectonic overpressure during metamorphism.
DS201703-0422
2017
Sasinkova, V.Klonowska, I., Janak, M., Majka, J., Petrik, I., Froitzheim, N., Gee, D.G., Sasinkova, V.Microdiamond on Areskutan confirms regional UHP metamorphism in the Seve Nappe Complex of the Scandinavian Caledonides.Journal of Metamorphic Geology, in press availableEurope, SwedenMicrodiamond

Abstract: Metamorphic diamond in crustal rocks provides important information on the deep subduction of continental crust. Here, we present a new occurrence of diamond within the Seve Nappe Complex (SNC) of the Scandinavian Caledonides, on Åreskutan in Jämtland County, Sweden. Microdiamond is found in situ as single and composite (diamond+carbonate) inclusions within garnet, in kyanite-bearing paragneisses. The rocks preserve the primary peak pressure assemblage of Ca,Mg-rich garnet+phengite+kyanite+rutile, with polycrystalline quartz surrounded by radial cracks indicating breakdown of coesite. Calculated P-T conditions for this stage are 830-840 °C and 4.1-4.2 GPa, in the diamond stability field. The ultrahigh-pressure (UHP) assemblage has been variably overprinted under granulite facies conditions of 850-860 °C and 1.0-1.1 GPa, leading to formation of Ca,Mg-poor garnet+biotite+plagioclase+K-feldspar+sillimanite+ilmenite+quartz. This overprint was the result of nearly isothermal decompression, which is corroborated by Ti-in-quartz thermometry. Chemical Th-U-Pb dating of monazite yields ages between 445 and 435 Ma, which are interpreted to record post-UHP exhumation of the diamond-bearing rocks. The new discovery of microdiamond on Åreskutan, together with other evidence of ultrahigh-pressure metamorphism (UHPM) within gneisses, eclogites and peridotites elsewhere in the SNC, provide compelling arguments for regional (at least 200 km along strike of the unit) UHPM of substantial parts of this far-travelled allochthon. The occurrence of UHPM in both rheologically weak (gneisses) and strong lithologies (eclogites, peridotites) speaks against the presence of large tectonic overpressure during metamorphism.
DS201709-2018
2017
Sasinkova, V.Klonowska, I., Janek, M., Majka, J., Petrik, I., Froitzheim, N., Gee, D.G., Sasinkova, V.Microdiamond on Areskutan confirms regional UHP metamorphism in the Seve Nappe Complex of the Scandinavian Caledonides.Journal of Metamorphic Geology, Vol. 35, 5, pp. 541-564.Europe, Scandinaviamicrodiamond

Abstract: Metamorphic diamond in crustal rocks provides important information on the deep subduction of continental crust. Here, we present a new occurrence of diamond within the Seve Nappe Complex (SNC) of the Scandinavian Caledonides, on Åreskutan in Jämtland County, Sweden. Microdiamond is found in situ as single and composite (diamond+carbonate) inclusions within garnet, in kyanite-bearing paragneisses. The rocks preserve the primary peak pressure assemblage of Ca,Mg-rich garnet+phengite+kyanite+rutile, with polycrystalline quartz surrounded by radial cracks indicating breakdown of coesite. Calculated P–T conditions for this stage are 830–840 °C and 4.1–4.2 GPa, in the diamond stability field. The ultrahigh-pressure (UHP) assemblage has been variably overprinted under granulite facies conditions of 850–860 °C and 1.0–1.1 GPa, leading to formation of Ca,Mg-poor garnet+biotite+plagioclase+K-feldspar+sillimanite+ilmenite+quartz. This overprint was the result of nearly isothermal decompression, which is corroborated by Ti-in-quartz thermometry. Chemical Th–U–Pb dating of monazite yields ages between 445 and 435 Ma, which are interpreted to record post-UHP exhumation of the diamond-bearing rocks. The new discovery of microdiamond on Åreskutan, together with other evidence of ultrahigh-pressure metamorphism (UHPM) within gneisses, eclogites and peridotites elsewhere in the SNC, provide compelling arguments for regional (at least 200 km along strike of the unit) UHPM of substantial parts of this far-travelled allochthon. The occurrence of UHPM in both rheologically weak (gneisses) and strong lithologies (eclogites, peridotites) speaks against the presence of large tectonic overpressure during metamorphism.
DS1992-1329
1992
Saskatchewan Energy and MinesSaskatchewan Energy and MinesSummary of investigations - 1992Saskatchewan Energy and Mines, Report No. 92-4, 240pSaskatchewanOverview of activities, Geology, gold, diamonds
DS1994-1527
1994
Saskatchewan Energy and MinesSaskatchewan Energy and MinesResults of reconnaissance sampling for kimberlite and lamproite indicatorminerals, Saskatchewan #2Saskatchewan Energy and Mines Open File, No. 93-4, $ 88.95 plus GST and PST.SaskatchewanGeochemistry, Sampling, Open file
DS2001-1016
2001
Saskatchewan Energy and MinesSaskatchewan Energy and MinesDiamond developments in 2001 - highlightsSaskatchewan Exploration Development, Nov. pp. 12-16.SaskatchewanExploration - brief review, Fort a la Corne
DS2002-1407
2002
Saskatchewan Energy and MinesSaskatchewan Energy and MinesDiamonds bolster spending in the northProspectors and Developers Association of Canada (PDAC) Exploration and, p.19SaskatchewanNews item - brief review
DS1993-1377
1993
Saskatchewan Energy and Mines -Geological SurveySaskatchewan Energy and Mines -Geological SurveyDigital gravity dat a base civering large sections of the Phanerozic Basinare being digitized to the WGS 84 Ellipsoidal Model. Dat a supplied in ASC IIformat.Saskatchewan Energy and Mines -Geological Survey, Preliminary notice (approx. end of July 1993)SaskatchewanGeophysics -gravity, Digital gravity data base
DS1996-1251
1996
Saskatchewan Exploration Dev. HighlightsSaskatchewan Exploration Dev. HighlightsDiamonds.... overviewSaskatchewan Exploration Dev. Highlights, pp. 12-14.SaskatchewanNews item
DS2003-1213
2003
Saskatchewan Geological SurveySaskatchewan Geological SurveyGeology, kimberlite explorationGeology and Mineral Resources of Saskatchewan, Misc. Rept. 2003-7, pp. 117-124.Saskatchewan, Fort a la CorneBlank
DS200412-1734
2003
Saskatchewan Geological SurveySaskatchewan Geological SurveyGeology, kimberlite exploration.Geology and Mineral Resources of Saskatchewan, Misc. Rept. 2003-7, pp. 117-124.Canada, Saskatchewan, Fort a la CorneOverview - exploration update, geology
DS2003-1214
2003
Saskatchewan Industry and ResourcesSaskatchewan Industry and ResourcesDiamonds .... brief overview of activities in province (coverage 2002-part of 2003)Geology and Mineral Resources of Saskatchewan, Miscellaneous Rept. 2003-7, pp. 117-124.SaskatchewanBlank
DS200412-1735
2003
Saskatchewan Industry and ResourcesSaskatchewan Industry and ResourcesDiamonds .... brief overview of activities in province (coverage 2002-part of 2003).Geology and Mineral Resources of Saskatchewan, Miscellaneous Rept. 2003-7, pp. 117-124.Canada, SaskatchewanNews item - brief overview
DS201501-0029
2014
Saskatchewan Mining AssociationSaskatchewan Mining AssociationWhere do diamonds come from and how can we find them? Overview of companies working in Saskatchewan ( Shore Gold, North Arrow, Stornoway)Saskatchewan Mining Association, Fall,Winter p. 5,6.Canada, SaskatchewanBrief overview
DS1992-1330
1992
Saskatoon Star-PhoenixSaskatoon Star-PhoenixDebate intensifies on Saskatchewan diamond theoriesSaskatoon Star-Phoenix, December 2, 1p.SaskatchewanNews item, Rhonda, Mitchell
DS201805-0974
2018
Sasman, F.Sasman, F., Deetlefs, B., van der Westhuyzen, P.Application of diamond size frequency distribution and XRT technology at a large diamond producer. The Journal of the Southern African Institute of Mining and Metallurgy, Vol. 118, Jan. pp. 1-6.Africa, South Africadiamond size frequency

Abstract: Diamond size frequency distribution (SFD) curves, combined with the associated dollar per carat per size class, play an important role in the diamond industry. Value per size class is unique for each deposit and typically varies from less than a dollar per carat to several thousands of dollars per carat for special stones. Recovery of large stone therefore contributes significantly to the bottom line of a large diamond producer. While the design of the process plant should prevent damage and possible breakage of large stones, it should also ensure adequate liberation of the finer diamonds. Innovative solutions are required to protect and recover type I and II diamonds if prominent within the resource. X-ray transmission (XRT) sorting presents the opportunity to develop flow sheet designs that incorporate a balance between exploitation of the resource and process efficiency, as well as practical capital and operating costs. This paper serves to illustrate the role and application of SFD curves in determining optimum cut-off and re-crush sizes within the flow sheet of a large diamond producer. A thorough understanding of the unique technical and economic aspects of a deposit provides the basis from where new and innovative technologies can be proposed, allowing mining companies to maintain and improve profit margins. It highlights the results of various plant trials and newly commissioned XRT sorters for larger size fractions. It also provides recommendations for future applications of XRT machines in the diamond process flow sheet.
DS1989-1342
1989
Sass, J.H.Sass, J.H., Blackwell, D.D., Chapman, D.S., Costain, J.K., DeckerHeat flow from the crust of the United StatesPhysical Properties of Rocks and Minerals, Ed. Y.S. Touloukian, W.R., ISBN 0-89116-883-4 $ 95.00 548p. pp. 503-GlobalHeat flow, Mantle
DS200712-0958
2008
Sass, O.Schrott, L., Sass, O.Application of field geophysics in geomorphology: advances and limitations exemplified by case studies.Geomorphology, Vol. 93, 1-2, Jan. pp. 55-73.TechnologyGeophysics - seismics, GPR, DC resistivity - review
DS1993-1075
1993
Sassano, G.Moroz, R., Sassano, G.Significance of the contact metasomatic alteration of Christopher Island Formation minettes and associated alkaline intrusions.Geological Society of America northwest section, Vol. 25, No. 2, p. 66 abstractNorthwest Territories, Dubawnt LakeMinettes, Alkaline rocks
DS201902-0318
2019
Sasse, D.Sasse, D., Jones, T.J., Russell, K.Experimental milling of olivine: implications for ascent and eruption of kimberlite.AME Roundup, 1p. Abstract pp. 28-31.Mantlekimberlite genesis

Abstract: Kimberlite magmas entrain, transport and erupt large volumes of mantle-derived olivine grains. Characteristically, the olivine crystals found in kimberlite are rounded and ellipsoidal in shape. The origin of their ellipsoidal morphologies remains somewhat enigmatic given their origin from disaggregation of lithospheric mantle rocks. Explanations include rounding by magmatic corrosion and dissolution (Kamenetsky et al. 2008; Pilbeam et al. 2013) or mechanical milling (Arndt et al. 2006; Arndt et al. 2010; Russell et al. 2012; Jones et al. 2014; Brett et al. 2015). Here, we focus on mechanical processes that operate during turbulent mantle ascent, facilitating reshaping and resurfacing of olivine. During transport orthopyroxene and other mantle minerals are assimilated by the kimberlite magma. One effect of the assimilation is to raise the melt’s SiO2 content, thereby causing a reduction in CO2 solubility and the spontaneous exsolution of a CO2-dominated fluid phase (Brooker et al. 2011; Russell et al. 2012; Moussallam et al. 2015). This assimilation-driven exsolution of a fluid phase provides a continuous decrease in density, an increase in buoyancy, and an accelerating ascent. Additionally, there is strong evidence that, during kimberlite magma ascent through the mantle lithosphere, substantial mechanical modification of the suspended cargo occurs (Jones et al. 2014; Brett et al. 2015). Brett et al. (2015) hypothesized that the ascending dyke segregates into a turbulent gas-rich head where particleparticle interactions dominate followed by a trailing tail of less gas-charged magma. This ascending dyke continually modifies its cargo from initial disaggregation to ultimately, eruption. Here, we present data from a series of novel, scaled, analogue attrition experiments that inform on the rates, efficiency and timings of mechanical modification possible during transport through the mantle lithosphere.
DS201907-1554
2019
Sasse, D.Jones, T.J., Russell, J.K., Sasse, D.Modification of mantle cargo by turbulent ascent of kimberlite.Frontiers in Earth Science, Vol. 7, pp. 134-145. pdfGlobalkimberlite genesis

Abstract: Kimberlite magmas transport cratonic mantle xenoliths and diamonds to the Earth's surface. However, the mechanisms supporting the successful and efficient ascent of these cargo-laden magmas remains enigmatic due to the absence of historic eruptions, uncertainties in melt composition, and questions concerning their rheology. Mantle-derived xenocrystic olivine is the most abundant component in kimberlite and is uniquely rounded and ellipsoidal in shape. Here, we present data from a series of attrition experiments designed to inform on the transport of low-viscosity melts through the mantle lithosphere. The experimental data suggest that the textural properties of the mantle-derived olivine are records of the flow regime, particle concentration, and transport duration of ascent for kimberlitic magmas. Specifically, our results provide evidence for the rapid and turbulent ascent of kimberlite during their transit through the lithosphere; this transport regime creates mechanical particle-particle interactions that, in combination with chemical processes, continually modify the mantle cargo and facilitate mineral assimilation.
DS202009-1656
2020
Sasse, D.Sasse, D., Jones, T.J., Russell, J.K.Transport, survival and modification of xenoliths and xenocrysts from source to surface.Earth and Planetary Science Letters, Vol. 548, 12p. PdfMantlekimberlite ascent

Abstract: A wide variety of magmas entrain, transport and erupt mantle material in the form of xenoliths and xenocrysts. The host magmas are often low viscosity in nature and range from basalt to more esoteric compositions such as kimberlite, nephelinite and basanite. Here we focus on kimberlite magmas which are particularly successful at transporting deep mantle cargo to the surface, including economically important quantities of diamond. Collections of mantle-derived xenoliths and xenocrysts are critical to our understanding of the structure, stability, composition, thermal state, age, and origin of the lithosphere. However, they also inform on magma transport conditions. Through a series of scaled analogue experiments, we document the relative mechanical stability of olivine, garnet, orthopyroxene, clinopyroxene and diamond xenocrysts during magma ascent. Our experiments fluidized these mantle minerals at a constant gas flux for variable amounts of time approximating transport in a high velocity, turbulent, fluid-rich (supercritical fluid or gas, depending on depth) magma. The evolution of mineral surface features, morphology and grain size distributions is analyzed as a function of residence time. We show that on timescales consistent with magma ascent, each mantle mineral is subject to mechanical modification resulting in mass loss and reshaping (rounding) by grain size reduction and surface pitting. We further discuss the chemical consequences of producing fine particle chips that are highly susceptible to dissolution. Lastly, we utilize an empirical model that relates textural observations (e.g. impact pit size) on xenocrysts to differential particle velocities. Our approach applied to natural kimberlitic olivine and garnet xenocrysts indicates differential velocities of - the first direct estimate for velocity in an ascending kimberlite magma.
DS2000-0855
2000
Sassi, R.Sassi, R., Harte, B., Carswell, D.A., Yujing, H.Trace element distribution in Central Dabie eclogitesContributions to Mineralogy and Petrology, Vol. 139, No. 3, pp. 298-315.China, east central ChinaEclogites, petrology, Dabie Shan, Deposit - Dabie Shan
DS1995-0330
1995
Sassi, W.Cloetingh, S., D'Argentio, B., Sassi, W.Interplay of extension and compression in basin formation - introductionTectonophysics, Vol. 252, No. 1-4, Dec. 30, pp. 1-6GlobalBasins, Tectonics
DS1991-1497
1991
Sastry, B.B.K. etal.Sastry, B.B.K. etal.Regional surveys for hidden kimberlites in Jonnagiri Peapully Hussainapuramarea, Kurnool District, Andhra Pradesh.Records Geological Survey of India, Vol. 124, pt. 5, pp. 40-42.IndiaGeophysics
DS200612-1226
2005
Sastry, C.A.Sastry, C.A., Rama Rao, G., Prasad, G.J.S., Reddy, V.A.Electro probe micro analysis of indicator minerals from kimberlites of Andhra Pradesh and Karnataka.Geological Survey of India, Bulletin, C6, 282p. Cited in GJSI. 67, 2, p. 280.India, Andhra Pradesh, KarnatakaGeochemistry
DS1950-0115
1952
Sastry, C.K.R.Sastry, C.K.R.Geology of the Uravakonda Subtaluk and Northwest Part of the Anantapur Taluk.India Geological Survey Madras State., UNPB.India, MadrasRegional Geology
DS201511-1877
2015
Sastry, M.D.Sastry, M.D., Mane, S., Gaonkar, M., Bhide, M.K., Desai, S.N., Ramachandran, K.T.Luminescence studies of gemstones and diamonds.International Journal of Luminescence and Applications, Vol. 5, 3, pp. 293-297.TechnologyLuminescence

Abstract: Some of the minerals like Corundum, chryso beryl, beryllium alumino silicate (emerald) and also Diamond exhibit exceptional optical properties[1] and in some cases attractive colours; in India these were recognized quite early since the days of Indus valley civilization. In more recent times there has been a lot of scientific interest in colours and colour modifications in Gem minerals and in Diamonds. Science of gem stones deals with their identification by non destructive means and understanding of origin of colour and excellent optical properties[1]. Optical methods have long been used to obtain properties like ‘Refractive Index’ which still remains an important parameter as a preliminary test to identify the gemstone/mineral. The spectroscopic studies of gem grade minerals are essentially directed towards some of these features in identifying and understanding the spectral properties of chromophores, either chemical impurities and/or radiation induced point defects, in solids. In this context a variety of spectroscopic methods are used to address the problems of the Gem stone identification and identification of origin of colours and colour modification treatments. The methods frequently used in Gem testing labs are the following: (i)Electronic absorption in UV-Visible-NIR range.(ii)UV-Vis excited luminescence, (iii) Vibrational spectra – Absorption in the Infra red range (iv) Vibrational spectra using Light Scattering (Raman spectroscopy) (v)Surface Fluorescence mapping Under deep UV excitation. The present paper deals with the luminescence studies in rubies, sapphires, emeralds and diamonds. Special mention may be made of fluorescence mapping using deep UV excitation (around 205 nm) corresponding to the band gap of diamond. Under such an excitation inter band excitation takes place creating a e-h pair and most of the absorption and subsequent emission being restricted to the surface. This makes surface mapping possible and thereby elucidating the growth patterns. This is invaluable in the diagnostics for the detection of synthetic diamonds. In this introductory presentation on the Luminescence methods in Gemmology, we give a brief account of optical spectroscopic methods which mainly deal with identification of corundum based gem stones (rubies, sapphire) and diamonds including the electronic absorption and luminescence of chromophore centres. In gem testing infrared absorption and Raman scattering methods are main work horses and they will be brought in as and when necessary to give a complete picture.
DS1994-0057
1994
Sastry, R.S.Apparao, A., Sastry, R.S., Sarma, V.S.Spectral IP studies buried scale models incorporating surface and volumepolarizationExploration Geophysics, Australian Bulletin, Vol. 25, No. 1, March pp. 31-38AustraliaGeophysics -IP, Models
DS200412-0590
2004
Sata, N.Fujino, K., sasaki, Y., Komori, T., Ogawa, H., Miyajima, N., Sata, N., Yagi, T.Approach to the mineralogy of the lower mantle by a combined method of a laser heated diamond anvil cell experiment and analyticPhysics of the Earth and Planetary Interiors, Vol. 143-144, pp. 215-221.MantleMineralogy - experimental
DS200412-1381
2004
Sata, N.Murakami, M., Hirose, K., Kawamura, K., Sata, N., Ohishi, Y.Phase transition of MgSiO3 perovskite in the deep lower mantle.Lithos, ABSTRACTS only, Vol. 73, p. S78. abstractMantleSeismic discontinuity
DS200512-0436
2005
Sata, N.Hirose, K., Takafuji, N., Sata, N., Ohishi, Y.Phase transition and density of subducted MORB crust in the lower mantle.Earth and Planetary Science Letters, Vol. 237, 1-2, Aug, 30, pp. 239-251.MantleMineral chemistry, subduction
DS200712-0763
2007
Sata, N.Murkami, M., Sinogeikin, S.V., Bass, J.D., Sata, N., Ohishi, Y., Hirose, K.Sound velocity of MgSiO3 post perovskite phase: a constraint on the D' discontinuity.Earth and Planetary Science Letters, Vol. 259, 1-2, July 15, pp. 18-23.MantleDiscontinuity
DS200812-0621
2008
Sata, N.Kuwayama, Y., Horise, K., Sata, N., Ohisi, Y.Phase relations of iron and iron-nickel alloys up to 300 GPa:implications for composition and structure of the Earth's inner core.Earth and Planetary Science Letters, Vol. 273, 3-4 pp. 379-385.MantleCore, chemistry
DS200812-0817
2008
Sata, N.Ohta, K., Hirose, K., Lay, T., Sata, N., Ohishi, Y.Phase transitions in pyrolite and MORB at lowermost mantle conditions: implications for a MORB rich pile above the core-mantle boundary.Earth and Planetary Science Letters, Vol. 267, 1-2, pp.107-117.MantlePetrology
DS200912-0695
2008
Sata, N.Sinmyo, R., Ozawa, H., Jirose, K., Yasuhara, A., Endo, N., Sata, N., Ohishi, Y.Ferric iron content in (Mg,Fe) SiO3 perovskite and post-perocskite at deep lower mantle conditions.American Mineralogist, Vol. 93, 11/12 pp. 1899-1902.MantlePerovskite
DS200912-0649
2007
Sathyanarayan, M.Roy, P.,Balaram, V., Kumar, A., Sathyanarayan, M., Gnaneshwara, Rao, T.New REE and trace element dat a on two kimberlite reference materials by ICP-MS.Geostandards and Geoanalytical Research, Vol. 31, pp. 261-273.IndiaGeochronology
DS201412-0709
2014
Sathyanarayanan, M.Prabhakar, N., Bhattacharya, A., Sathyanarayanan, M., Mukherjee, P.K.Structural, petrological and chronological constraints from eastern India and implications for the ~1.0 Ga assembly of greater India.Journal of Geology, Vol. 122, 4, pp. 411-432.IndiaGeochronology
DS1987-0649
1987
Satian, M.A.Satian, M.A., Khanzatyan, G.A.Rocks of the lamproite series in the ophiolite section of the Vediophiolite zone of Lesser Caucasus.(Russian)Izv. Akad. Nauk SSSR, Armyanskoy , Nauki o Zamle, (in Russian), Vol. 40, nol. 5, pp. 64-67RussiaLamproite, Ophiolite
DS200912-0667
2009
Satian, M.A.Satian, M.A., Sahakyan, L.H., Stepanyan, O.Composition of tuffs from lamprophyre diatremes of the Vedi Rift, Armenia.Lithology and Mineral Resources, Vol. 44, 4, pp. 399-409.Africa, ArmeniaLamprophyre
DS201012-0664
2010
Satikune, S.Satikune, S., Zubko, M., Hager, T., Kusz, J., Hofmeister, W.Mineral chemistry and structural relationships of inclusions in diamond crystals. Koffiefontein and FinschInternational Mineralogical Association meeting August Budapest, abstract p. 25.Africa, South AfricaDiamond inclusions
DS1995-0781
1995
Satir, M.Hegner, E., Walter, H.J., Satir, M.lead, Strontium, neodymium isotope compositions and trace element geochemistry of megacrysts and melilitites from UrachContributions to Mineralogy and Petrology, Vol. 122, pp. 322-335.GermanyTertiary Urach field, isotopes, European Volcanic Province
DS1995-2042
1995
Satir, M.Wegner, E., Walter, H.J., Satir, M.lead, Strontium, neodymium isotopic compositions and trace element geochemistry of megacrysts and melilitites Tertiary...Contributions to Mineralogy and Petrology, Vol. 122, No. 3, pp. 322-GermanyMelts, isotopes, Urach volcanic field
DS1997-0569
1997
Satir, M.Kalt, A., Hegner, E., Satir, M.neodymium, Strontium, and lead isotopic evidence for diverse lithospheric mantle sources of East African carbonatiteTectonophysics, Vol. 278, No. 1-4, Sept. 15, pp. 31-46.Africa, east Africa, Tanzania, KenyaTectonics, Rifting, Carbonatite
DS2003-0245
2003
Satir, M.Chen, F., Siebel, W., Guo, J., Cong, B., Satir, M.Late Proterozoic magmatism and metamorphism in gneisses from the Dabie highPrecambrian Research, Vol. 120, 1-2, pp.131-148.ChinaMagmatism, UHP
DS200412-0316
2003
Satir, M.Chen, F., Siebel, W., Guo, J., Cong, B.,Satir, M.Late Proterozoic magmatism and metamorphism in gneisses from the Dabie high pressure metamorphic zone, eastern China: evidence fPrecambrian Research, Vol. 120, 1-2, pp.131-148.ChinaMagmatism UHP
DS200412-1968
2004
Satir, M.Taubald, H., Mrteani, G., Satir, M.Geochemical and isotopic SR C O dat a from the alkaline complex of Gronnedal-lka South Greenland; evidence for unmixing and crustInternational Journal of Earth Sciences, Vol. 93, 3, pp. 348-60.Europe, GreenlandGeochemistry, alkaline, geochronology
DS200512-0963
2004
Satir, M.Shang, C.K., Satir, M., Siebel, W., Nsifa, E.N., Taubald, H., Ligeois, J.P., Tchoua, F.M.TTG Magmatism in the Congo Craton: a view from major and trace element geochemistry, Rb Sr Sm Nd systematics: case of the Sangmelima region, Ntem ComplexJournal of African Earth Sciences, Vol. 39, 3-5, pp. 61-79.Africa, CameroonMagmatism
DS201801-0044
2017
Satish Kumar, K.Pandey, O.P., Chandrakala, K., Vasanthi, A., Satish Kumar, K.Seismically imaged shallow and deep crustal structure and potential field anomalies across the Eastern Dharwar Craton, south Indian shield: possible geodynamical implications.Journal of Asian Earth Sciences, in press available, 11p.Indiageophysics - seismics

Abstract: The time-bound crustal evolution and subsequent deformation of the Cuddapah basin, Nellore Schist Belt and Eastern Ghats terrain of Eastern Dharwar Craton, which have undergone sustained geodynamic upheavals since almost 2.0 billion years, remain enigmatic. An attempt is made here to integrate newly available potential field data and other geophysical anomalies with deep seismic structure, to examine the generative mechanism of major crustal features, associated with this sector. Our study indicates that the initial extent of the Cuddapah basin sedimentation may have been much larger, extending by almost 50-60?km west of Tadipatri during Paleoproterozoic period, which subsequently shrank due to massive erosion following thermal uplift, caused by SW Cuddapah mantle plume. Below this region, crust is still quite warm with Moho temperatures exceeding 500?°C. Similarly, Nallamalai Fold Belt rocks, bounded by two major faults and extremely low gravity, may have occupied a large terrain in western Cuddapah basin also, before their abrasion. No geophysical signatures of thrusting are presently seen below this region, and thus it could not be an alien terrain either. In contrast, Nellore Schist Belt is associated with strikingly high positive gravity, possibly caused by a conspicuous horst structure and up dipping mafic crustal layers underneath, that resulted due to India-east Antarctica collision after the cessation of prolonged subduction (1.6-0.95?Ga). Further, the crustal seismic and gravity signatures would confirm presence of a totally distinct geological terrain east of the Cuddapah basin, but the trace of Eastern Ghats Belt is all together missing. Instead, all the geophysical signatures, point out to presence of a Proterozoic sedimentary terrain, east of Nellore Schist Belt. It is likely that the extent of Prorerozoic sedimentation was much larger than thought today. In addition, presence of a seismically detected Gondwana basin over Nellore Schist Belt, apart from some recently discovered similar subsurface Gondwana occurrences in intracratonic parts, would indicate that Dharwar Craton was rifting even during Gondwana period, thereby challenging the long held view of cratonic stability.
DS200612-1227
2006
Satish-Kumar, M.Satish-Kumar, M., Hermann, J., Miyamoto, T., Osanai, Y.Fingerprinting fluid processes in the continental crust: an integrated approach using grain scale Sr, C, O isotopes and REE geochemistry.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 557, abstract only.MantleGeochronology
DS201112-0916
2011
Satish-Kumar, M.Satish-Kumar, M., So, H., Yoshino, T., Kato, M., Hiroi, Y.Experimental determination of carbon isotope fractionation between iron carbide melt and carbon: 12 C-enriched carbon in the Earth's core?Earth and Planetary Science Letters, Vol. 310, 3-4, pp. 340-348.MantleCarbon
DS202108-1271
2021
Satish-Kumar, M.Banerjee, A., Satish-Kumar, M., Chakrabarti, R.Sulfur, carbon and oxygen isotopic compositions of Newania carbonatites of India: implications for the mantle source characteristics.Journaof Mineralogical and Petrological Sciences, Vol. 116, pp. 121-128 pdfIndiadeposit - Newania

Abstract: This study presents first report of the sulfur isotopic compositions of carbonatites from the Mesoproterozoic Newania complex of India along with their stable C and O isotope ratios. The ?34SV-CDT (?1.4 to 2‰) and ?33S (?0.001 to ?0.13‰) values of these carbonatite samples (n = 7) overlap with the S isotope compositions of Earth’s mantle. Additionally, the ?13CV-PDB and ?18OV-SMOW values of these carbonatites also show overlapping compositions to that of Earth’s mantle. Based on these mantle-like stable isotopic compositions of carbonatites along with their higher crystallization temperature (~ 600 °C) compared to a hydrothermal fluid (<250 °C), we suggest that the sulfide minerals in these carbonatites were formed under a magmatic condition. The mantle like signatures in the ?34S, ?13C- ?18O, and 87Sr/86Sr values of these carbonatites rule out possible crustal contamination. Coexistence of the sulfide phase (pyrrhotite) with magnesite in these carbonatites suggests that the sulfide phase has formed early during the crystallization of carbonatite magmas under reducing conditions. Overall restricted variability in the ?34S values of these samples further rules out any isotopic fractionation due to the change in the redox condition of the magma and reflect the isotopic composition of the parental melts of the Newania carbonatite complex. A compilation of ?34S of carbonatites from Newania and other complexes worldwide indicates limited variability in the isotopic composition for carbonatites older than 400 Ma, which broadly overlaps with Earth’s asthenospheric mantle composition. This contrasts with the larger variability in ?34S observed in carbonatites younger than 400 Ma. Such observation could suggest an overall lower oxidation state of carbonatite magmas emplaced prior to 400 Ma.
DS200812-0786
2008
SatitkuneNasdala, L., Gigler, Wildner, Grambole, Zaitsev, Harris, Hofmeister, Milledge, SatitkuneAlpha radiation damage in diamond.Goldschmidt Conference 2008, Abstract p.A672.TechnologyDiamond morphology
DS1989-1343
1989
Sato, H.Sato, H., Sacks, I.S., Murase, T., Muncill, G., Fukuyama, H.Qp-melting temperature relation in peridotite at high pressure andtemperature: attenuation mechanism And implications for the mech. prop. of The upper mantleJournal of Geophysical Research, Vol. 94, No. B8, August 10, pp. 10, 647-10, 661GlobalMantle, Peridotite -experimental
DS1991-1498
1991
Sato, H.Sato, H.Oxygen fugacities of iron O mineral assemblages in relation to carbon oxidation in the earthEos, Spring Meeting Program And Abstracts, Vol. 72, No. 17, April 23, p. 142GlobalMantle, Geochemistry
DS2002-1408
2002
Sato, H.Sato, H., Ito, K.Olivine pyroxene H2O system as a practical analogy for estimating the elastic properties of fluid bearing mantle rocks at high pressures and temperatures.Geophysical Research Letters, Vol. 29,9,May 1, p. 39-ChinaUHP
DS200612-0787
2005
Sato, H.Lee, W.S., Sato, H., Lee, K.Scattering coefficients in the mantle revealed from the seismogram envelope analysis based on the multiple isotropic scattering model.Earth and Planetary Science Letters, In pressMantleGeophysics - seismics, mantle heterogeneity, radiative
DS1987-0650
1987
Sato, J.Sato, J.Today and future for industrial applications of diamond. *JAPTetsu Hagan, *JAP, Vol. 73, No. 11, September pp. 1471-1478JapanIndustrial
DS1981-0364
1981
Sato, K.Sato, K., Sasaki, E.Application of Interference Contrast Microscopy to Identify coated Diamonds.Journal of GEMMOLOGICAL SOCIETY of JAPAN., Vol. 8, No. 1-8, PP.GlobalBlank
DS1983-0557
1983
Sato, K.Sato, K., Sunagawa, I.Quantitative evaluation of colour of diamonds byspecrophotometricmethod.*JAPHoseki Gakkhaishi ( Journal of Gemmol. Soc. Japan), *JAP, Vol. 9, No. 4, pp. 87-100GlobalDiamond Morphology, Spectrometry
DS1990-1293
1990
Sato, K.Saito, Y., Sato, K., Gomi, K., Miyadera, H.Diamond synthesis from CO-H2 mixed gas plasmaJournal of Material Science, Vol. 25, No. 28, February pp. 1246-1250GlobalDiamond synthesis, Gas plasma
DS1994-1528
1994
Sato, K.Sato, K.Crustal evolution of the Sao Francisco craton, Brasil, from samarium-neodymium (Sm-Nd) modelages.International Symposium Upper Mantle, Aug. 14-19, 1994, pp. 118-120.BrazilGeochronology, Sao Francisco craton
DS1994-1529
1994
Sato, K.Sato, K., Ito, E.A high pressure experimental study on an olivine lamproite: application to its petrogenesis.Institute Study Earth's Interior, Okayama University of, No. 61, May, 45p.AustraliaPetrology -experimental, Lamproites
DS1997-0997
1997
Sato, K.Sato, K.Melting experiments on a synthetic olivine lamproite composition up to 8GPa: implications topetrogenesisJournal Geophys. Research, Vol. 102, No. 7, July 10, pp. 14751-64.GlobalPetrology, Lamproite
DS1997-0998
1997
Sato, K.Sato, K., Katsura, T., Ito, F.Phase relations of natural phlogopite with/without enstatite up to 8 GPA -implication mantle MetasomatismEarth Planetary Science Letters, Vol. 146, No. 3-4, Feb. pp. 511-526.MantleMetasomatism
DS200812-1006
2008
Sato, K.Santosh, M., Tsunogae, T., Ohyama, H., Sato, K., Li, J.H., Liu, S.J.Carbonic metamorphism at ultrahigh temperatures: evidence from North Chin a Craton.Earth and Planetary Science Letters, Vol. 266, 1-2, pp. 149-165.ChinaUHP
DS200912-0831
2009
Sato, K.Yamamoto, J.,Nakai, S., Nishimura, K., Kaneoka, I., Sato, K., Okumura, T., Prikhodko,V.S., Arai, S.Intergranular trace elements in mantle xenoliths from Russian Far East: example for mantle metasomatism by hydrous melt.Island Arc, Vol. 18, 1, pp. 225-241.RussiaMetasomatism
DS201112-0064
2011
Sato, K.Basei, M., Svisero, D., Iwanuch, W., Sato, K.U Pb zircon ages of the Alto Paranaiba and Juin a kimberlitic provinces, Brazil.Goldschmidt Conference 2011, abstract p.496.South America, Brazil, Minas Gerais, Mato Grosso, Goias, RondoniaCoromandel region
DS202005-0763
2020
Sato, K.Teixeira, W., Cordani, U.G., Faleiros, F.M., Sato, K., Maurer, V.C., Ruiz, A.S., Azevedo, E.J.P.The Rio Apa Terrane reviewed: U-Pb zircon geochronology and provenance studies provide paleotectonic links with a growing Proterozoic Amazonia.Earth Science Reviews, Vol. 202, 103089 35p. PdfSouth America, Brazilcraton

Abstract: New and compiled data of zircon U-Pb ages and geochemical-isotopic constraints provide new insights into the orogenic evolution of the Rio Apa Terrane (RAT) and its close affinity with the Amazonia throughout the Proterozoic. Two terranes with distinct evolutionary histories built the RAT. The Porto Murtinho (2070-1940 Ma) and Amoguijá (1870-1820 Ma) magmatic arcs generated the Western Terrane which is mainly composed of short-lived crustal components. Granitoid rocks (1870 Ma) in the distal Corumbá Window indicate that the RAT is much larger in extent. The Caracol accretionary arc (1800-1740 Ma) and the associated Alto Tererê back-arc basin formed away from the Amoguijá belt, being roughly coeval with the adjoining Baía das Garças suite (1776 Ma) and Paso Bravo granitoid rocks (1774-1752 Ma). These tectonic units constitute the Eastern Terrane, whilst the NdHf isotopic constraints indicate derivation from a predominantly juvenile magma source with the minor input of crustal-derived contaminants. The youngest detrital zircon grains from the Alto Tererê samples gave 1740-1790 Ma ages and unimodal age spectra were mainly present. The basin infill was, therefore, most likely concomitant with the exhumation of the Caracol belt. Alto Tererê provenance study also included detritus from passive to active margin settings. The RAT underwent regional cooling between 1.35 and 1.27 Ga, documented mainly by 40Ar39Ar and KAr ages. This age pattern matches a collisional episode that formed the accretionary margin of Amazonia, suggesting that the RAT was a close neighbor at Ectasian times. The geodynamic interplay between them lasted until 1.1 Ga ago, highlighted by some shared-components of a LIP event.
DS1989-1129
1989
Sato, S.Nisida, Y., Mita, Y., Mori, K., Okuda, S., Sato, S., Yazu, S.Color centers in annealing of neutron irradiated type 1B and 1A diamondsMater. Sci. forum, Vol. 38-41, Proc.Int.defects semicond. 15th.2, 561-565GlobalDiamond morpholoyg, Irradiated
DS1990-1472
1990
Sato, S.Tomeoka, K., Ozima, M., Zashu, S., Sato, S., Yazu, S.X-ray micro-analysis of micro-inclusions in a Zaire coated diamond21st. Lunar And Planetary Science Conference, March 12-16, Houston, March 16 presentationDemocratic Republic of CongoDiamond morphology, X-ray microscopy
DS2002-0799
2002
Sato, S.Kagi, H., Sato, S., Kanda, T., Akagi, T.Internal strain and thermal history of carbonado inferred from photoluminescence spectroscopy: relationship to carbon isotopic compositions.Eos, American Geophysical Union, Spring Abstract Volume, Vol.83,19, 1p.Central African RepublicDiamond - morphology, carbonado
DS200712-0502
2007
Sato, S.Kagi, H., Sato, S., Akagi, T., Kanda, H.Generation history of carbonado inferred from photoluminescence spectra, cathodluminesence imaging, and carbon isotope composition.American Mineralogist, Vol. 91, 1, pp. 217-224.Africa, Central African RepublicCarbonado, radiation damage
DS200812-0961
2008
Sato, W.Rio, S., Kon, Y., Sato, W., Maruyana, S., Santosh, M., Zhao, D.The Grenvillian and Pan African orogens: world's largest orogenies through geologic time, and their implications on the origin of superplume.Gondwana Research, Vol. 14, 1-2, August pp. 51-72.MantleOrogeny
DS1989-0281
1989
Sato, Y.Collins, A.T., Kamo, M., Sato, Y.Intrinsic and extrinsic cathodluminescence from single crystal diamonds grown by chemical vapordepositionJournal of Phys. Cond, Vol. 1, No. 25, June 26, pp. 4029-4033GlobalDiamond synthesis, CVD.
DS201608-1436
2016
Sato, Y.Sakamaki, K., Sato, Y., Ogasawara, Y.Hydrous Na-garnet from Garnet Ridge products of mantle metasomatism underneath the Colorado Plateau.Progress in Earth and Planetary Science, Vol. 3, 20, 17p.United States, Colorado PlateauMetasomatism

Abstract: This is the first report on amphibole exsolution in pyrope from the Colorado Plateau. Pyrope crystals delivered from mantle depths underneath the Colorado Plateau by kimberlitic volcanism at 30 Ma were collected at Garnet Ridge, northern Arizona. The garnet grains analyzed in this study occur as discrete crystals (without adjacent rock matrix) and are classified into two major groups, Cr-rich pyrope and Cr-poor pyrope. The Cr-poor pyrope group is divided into four subgroups based on exsolved phases: amphibole lamella type, ilmenite lamella type, dense lamellae type, and clinopyroxene/amphibole lamellae type. Exsolved amphibole occurs in amphibole lamella type, dense lamellae type, and clinopyroxene/amphibole lamellae type of Cr-poor pyrope. The amphibole crystals tend to have preferred orientations in their garnet hosts and occur as monomineralic hexagonal or rhombic prisms and tablets, and as multimineralic needles or blades with other exsolved phases. Exsolved amphibole has pargasitic compositions (Na2O up to 1.6 apfu based on 23 oxygen). Garnet host crystals that have undergone amphibole exsolution have low OH contents (2-42 ppmw H2O) compared to garnets that do not have amphibole lamellae (up to 115 ppmw H2O). The low OH contents of garnets hosting amphibole lamellae suggest loss of OH from garnet during amphibole exsolution. Amphibole exsolution from pyrope resulted from breakdown of a precursor “hydrous Na-garnet” composition (Mg,Na+ x)3(Al2???x, Mgx)2Si3O12???2x(OH)2x. Exsolution of amphibole and other phases probably occurred during exhumation to depths shallower than 100 km prior to volcanic eruption. Based on the abundance and composition of exsolved clinopyroxene and amphibole lamellae in one garnet, hydrous Na-garnet had excess silicon (Si3.017 apfu, 12 oxygen normalization, vs. X3Y2Si3O12 for typical garnet). Comparison with experimental data suggests crystallization at pressures near 6-8 GPa. Garnet crystals that host exsolved amphibole have compositions (Pyp49-76, 3-10 wt% CaO, and up to 0.6 wt% Cr2O3) similar to garnets reported from pyroxenites, and have pyrope-almandine-grossular compositional ranges that overlap with the Cr-rich pyrope (typical lherzolitic garnet). Hydrous Na-garnet was likely formed by metasomatic reactions between Cr-rich pyrope and Na-rich aqueous fluid in the deep upper mantle. The most likely source of metasomatic Na-rich fluid is ancient oceanic crust that was subducted before subduction of the Farallon Plate beneath the Colorado Plateau.
DS1984-0436
1984
Satoh, H.Kubo, K., Satoh, H.Petrology of Lamphrophyre in the Urakawa Area, Hokkaido, Japan.Journal of Geological Society JAPAN., Vol. 90, No. 10, PP. 717-731.JapanPetrography, Chemical Analyses, Monchoquite, Miocene Age
DS200412-1736
2004
Satoh, H.Satoh, H., Yamaguchi, Y., Makino, K.Ti substitution mechanism in plutonic oxy-kaersutite from the Larvik alkaline complex, Oslo Rift, Norway.Mineralogical Magazine, Vol. 68, 4, Aug. 1, pp. 687-697.Europe, NorwayAlkaline rocks, mineralogy
DS200512-0915
2004
Satoh, H.Roy, A., Sarkar, A., Jeyakumar, S., Aggrawal, S.K., Ebihara, M., Satoh, H.Late Archean mantle metasomatism below eastern Indian Craton: evidence from trace elements, REE geochemistry and Sr Nd O isotope systematics of ultramafic dykes.Proceedings National Academy of Sciences India , Vol. 113, 4, pp. 649-666. Ingenta 1045680437IndiaMetasomatism, geochemistry
DS200512-0916
2004
Satoh, H.Roy, A., Sarkar, A., Jeyakumar, S., Aggrawal, S.K., Ebihara, M., Satoh, H.Late Archean mantle metasomatism below eastern Indian craton: evidence from trace elements, REE geochemistry and Sr Nd O isotope systematics of ultramafic dykes.Proceedings National Academy of Sciences India , Vol. 113, 4, pp. 649-665.India, AsiaPeridotite, harzburgite, geochronology
DS200512-0937
2004
Satoh, H.Satoh, H., Yamaguchi, Y., Makino, K.Ti substitution mechanism in plutonic oxy-kaesutite from the Larvik alkaline complex, Oslo Rift, Norway.Mineralogical Magazine, Vol. 68, 4, Aug. 1,pp. 687-697.Europe, NorwayPetrology - alkaline
DS201603-0402
2016
Sator, N.Moussallam, Y., Florian, P., Corradini, D., Morizet, Y., Sator, N., Vuilleumier, R., Guillot, B., Iacono-Marziano, G., Schmidt, B.C., Gaillard, F.The molecular structure of melts along the carbonatite-kimberlite-basalt compositional joint: CO (sub 2) and polymerisation.Earth and Planetary Science Letters, Vol. 434, pp. 129-140.TechnologyPetrology - experimental

Abstract: Transitional melts, intermediate in composition between silicate and carbonate melts, form by low degree partial melting of mantle peridotite and might be the most abundant type of melt in the asthenosphere. Their role in the transport of volatile elements and in metasomatic processes at the planetary scale might be significant yet they have remained largely unstudied. Their molecular structure has remained elusive in part because these melts are difficult to quench to glass. Here we use FTIR, Raman, 13C and 29Si NMR spectroscopy together with First Principle Molecular Dynamic (FPMD) simulations to investigate the molecular structure of transitional melts and in particular to assess the effect of CO2 on their structure. We found that carbon in these glasses forms free ionic carbonate groups attracting cations away from their usual ‘depolymerising’ role in breaking up the covalent silicate network. Solution of CO2 in these melts strongly modifies their structure resulting in a significant polymerisation of the aluminosilicate network with a decrease in NBO/Si of about 0.2 for every 5 mol% CO2 dissolved. This polymerisation effect is expected to influence the physical and transport properties of transitional melts. An increase in viscosity is expected with increasing CO2 content, potentially leading to melt ponding at certain levels in the mantle such as at the lithosphere-asthenosphere boundary. Conversely an ascending and degassing transitional melt such as a kimberlite would become increasingly fluid during ascent hence potentially accelerate. Carbon-rich transitional melts are effectively composed of two sub-networks: a carbonate and a silicate one leading to peculiar physical and transport properties.
DS202002-0215
2020
Sator, N.Ritter, X., Sanchez-Valle, C., Sator, N., Desmaele, E., Guignot, N., King, A., Kupenko, I., Berndt, J., Guillot, B.Density of hydrous carbonate melts under pressure, compressability of volatiles and implications for carbonate melt mobility in the upper mantle.Earth and Planetary Science Letters, Vol. 533, 11p. PdfMantlecarbon

Abstract: Knowledge of the effect of water on the density of carbonate melts is fundamental to constrain their mobility in the Earth's interior and the exchanges of carbon between deep and surficial reservoirs. Here we determine the density of hydrous MgCO3 and CaMg(CO3)2 melts (10 wt% H2O) from 1.09 to 2.98 GPa and 1111 to 1763 K by the X-ray absorption method in a Paris-Edinburgh press and report the first equations of state for hydrous carbonate melts at high pressure. Densities range from 2.26(3) to 2.50(3) g/cm3 and from 2.34(3) to 2.48(3) g/cm3 for hydrous MgCO3 and CaMg(CO3)2 melts, respectively. Combining the results with density data for the dry counterparts from classical Molecular Dynamic (MD) simulations, we derive the partial molar volume (, ) and compressibility of H2O and CO2 components at crustal and upper mantle conditions. Our results show that in alkaline carbonate melts is larger and less compressible than at the investigated conditions. Neither the compressibility nor depend on carbonate melt composition within uncertainties, but they are larger than those in silicate melts at crustal conditions. in alkaline earth carbonate melts decreases from 25(1) to 16.5(5) cm3/mol between 0.5 and 4 GPa at 1500 K. Contrastingly, comparison of our results with literature data suggests strong compositional effects on , that is also less compressible than in transitional melts (e.g., kimberlites) and carbonated basalts. We further quantify the effect of hydration on the mobility of carbonate melts in the upper mantle and demonstrate that 10 wt% H2O increases the mobility of MgCO3 melts from 37 to 67 g.cm?3.Pa?1s?1 at 120 km depth. These results suggest efficient carbonate melt extraction during partial melting and fast migration of incipient melts in the shallow upper mantle.
DS202102-0190
2019
Sator, N.Gaillard, F., Sator, N., Guillot, B., Massuyeau, M.The link between the physical and chemical properties of carbon-bearing melts and their application for geophysical imaging of Earth's mantleResearchgate , DOI: 10.1017/ 9781108677950.007 26p. Pdfmantlecarbon

Abstract: Significant investment in new capacities for experimental research at high temperatures and pressures have provided new levels of understanding about the physical properties of carbon in fluids and melts, including its viscosity, electrical conductivity, and density. This chapter reviews the physical properties of carbon-bearing melts and fluids at high temperatures and pressures and highlights remaining unknowns left to be explored. The chapter also reviews how the remote sensing of the inaccessible parts of the Earth via various geophysical techniques - seismic shear wave velocity, attenuation, and electromagnetic signals of mantle depths - can be reconciled with the potential presence of carbon-bearing melts or fluids.
DS1985-0476
1985
Satow, Y.Nakazawa, H., Tagai, T., Hirai, H., Satow, Y.X-ray Section Topographs of a Cube Shaped DiamondMineralogical Journal, Vol. 12, No. 6, pp. 245-250GlobalDiamond Morphology
DS200412-2180
2004
Satrostenko, V.I.Yegorova, T.P., Stephenson, R.A., Kostyuchenko, S.L., Baranova, E.P., Satrostenko, V.I., Popolitov, K.E.Structure of the lithosphere below the southern margin of the East European Craton ( Ukraine and Russia) from gravity and seismiTectonophysics, Vol. 381, 1-4, pp. 81-100.Europe, UkraineTectonics
DS200812-1007
2008
Satry, R.S.Satry, R.S., Nagarajan, N., Sarma, S.V.S.Electrical imaging of deep crustal features of Kutch, India.Geophysical Journal International, Vol. 172, no. 3, March pp. 934-944.IndiaGeophysics - seismics
DS201606-1090
2016
Satsukawa, T.Griffin, W.L., Afonso, J.C., Belousova, E.A., Gain, S.E., Gong, X-H., Gonzalez-Jiminez, J.M., Howell, D., Huang, J-X., McGowan, N., Pearson, N.J., Satsukawa, T., Shi R., Williams, P., Xiong, Q., Yang, J-S., Zhang, M., O'Reilly, S.Y.Mantle recycling: transition zone metamorphism of Tibetan ophiolitic peridotites and its tectonic implications.Journal of Petrology, in press available, 30p.Asia, China, TibetPeridotite

Abstract: Large peridotite massifs are scattered along the 1500?km length of the Yarlung-Zangbo Suture Zone (southern Tibet, China), the major suture between Asia and Greater India. Diamonds occur in the peridotites and chromitites of several massifs, together with an extensive suite of trace phases that indicate extremely low fO2 (SiC, nitrides, carbides, native elements) and/or ultrahigh pressures (UHP) (diamond, TiO2 II, coesite, possible stishovite). New physical and isotopic (C, N) studies of the diamonds indicate that they are natural, crystallized in a disequilibrium, high-T environment, and spent only a short time at mantle temperatures before exhumation and cooling. These constraints are difficult to reconcile with previous models for the history of the diamond-bearing rocks. Possible evidence for metamorphism in or near the upper part of the Transition Zone includes the following: (1) chromite (in disseminated, nodular and massive chromitites) containing exsolved pyroxenes and coesite, suggesting inversion from a high-P polymorph of chromite; (2) microstructural studies suggesting that the chromitites recrystallized from fine-grained, highly deformed mixtures of wadsleyite and an octahedral polymorph of chromite; (3) a new cubic Mg-silicate, with the space group of ringwoodite but an inverse-spinel structure (all Si in octahedral coordination); (4) harzburgites with coarsely vermicular symplectites of opx + Cr-Al spinel ± cpx; reconstructions suggest that these are the breakdown products of majoritic garnets, with estimated minimum pressures to?>?13?GPa. Evidence for a shallow pre-metamorphic origin for the chromitites and peridotites includes the following: (1) trace-element data showing that the chromitites are typical of suprasubduction-zone (SSZ) chromitites formed by magma mixing or mingling, consistent with Hf-isotope data from magmatic (375?Ma) zircons in the chromitites; (2) the composition of the new cubic Mg-silicate, which suggests a low-P origin as antigorite, subsequently dehydrated; (3) the peridotites themselves, which carry the trace element signature of metasomatism in an SSZ environment, a signature that must have been imposed before the incorporation of the UHP and low-fO2 phases. A proposed P-T-t path involves the original formation of chromitites in mantle-wedge harzburgites, subduction of these harzburgites at c. 375?Ma, residence in the upper Transition Zone for >200 Myr, and rapid exhumation at c. 170-150?Ma or 130-120?Ma. Os-isotope data suggest that the subducted mantle consisted of previously depleted subcontinental lithosphere, dragged down by a subducting oceanic slab. Thermomechanical modeling shows that roll-back of a (much later) subducting slab would produce a high-velocity channelized upwelling that could exhume the buoyant harzburgites (and their chromitites) from the Transition Zone in?
DS201708-1576
2017
Satsukawa, T.Lu, J-G., Xiong, Q., Griffin, W.L., Zheng, J-P., Huang, J-X., O'Reilly, S.Y., Satsukawa, T., Pearson, N.J.Uplift of southeastern Australian lithosphere: thermal tectonic evolution of garnet pyroxenite xenoliths from western Victoria.Geological Society of London, Chapter 2, pp. 27-48.Australia, Victoriaxenoliths

Abstract: Detailed petrography, microstructure, and geochemistry of garnet pyroxenite xenoliths in Holocene basanite tuffs from maars at Lakes Bullenmerri and Gnotuk (western Victoria, southeastern Australia) have been used to track their igneous and metamorphic history, enabling the reconstruction of the thermal-tectonic evolution of the lithospheric mantle. The exsolution of orthopyroxene and garnet and rare spinel, plagioclase, and ilmenite from complex clinopyroxene megacrysts suggests that the xenoliths originally were clinopyroxene-dominant cumulates associated with minor garnet, orthopyroxene, or spinel. The compositions of exsolved phases and their host clinopyroxene were reintegrated using measured modal proportions to show that the primary clinopyroxene was enriched in Al2O3 (5.53–13.63 wt%) and crystallized at ~1300–1500 °C and 16–30 kbar. These cumulates then underwent extensive exsolution, recrystallization, and reaction during cooling, and finally equilibrated at ~950–1100 °C and 12–18 kba
DS201709-1998
2017
Satsukawa, T.Henry, H., Afonso, J.C., Satsukawa, T., Griffin, W.L., O'Reilly, S.Y., Kaczmarek, M-A., Tilhac, R., Gregoire, M., Ceuleneer, G.The unexplored potential impact of pyroxenite layering on upper mantle seismic properties.Goldschmidt Conference, abstract 1p.Europe, Spain, United States, Californiageophysics - seismics

Abstract: It is now accepted that significant volumes of pyroxenites are generated in the subduction factory and remain trapped in the mantle. In ophiolites and orogenic massifs the geometry of pyroxenite layers and their relationships with the host peridotite can be observed directly. Since a large part of what is known about the upper mantle structure is derived from the analysis of seismic waves, it is crucial to integrate pyroxenites in the interpretations. We modeled the seismic properties of a peridotitic mantle rich in pyroxenite layers in order to determine the impact of layering on the seimsic properties. To do so, EBSD data on deformed and undeformed pyroxenites from the Cabo Ortegal complex (Spain) and the Trinity ophiolite (California, USA) respectively are combined with either A or B-type olivine fabrics in order to model a realistic pyroxenite-rich upper mantle. Consideration of pyroxeniterich domains within the host mantle wall rock is incorporated in the calculations using the Schoenberg and Muir group theory [1]. This quantification reveals the complex dependence of the seismic signal on the deformational state and relative abundance of each mineral phase. The incorporation of pyroxenites properties into geophysical interpretations in understanding the lithospheric structure of subduction zones will lead to more geologically realistic models.
DS201711-2514
2017
Satsukawa, T.Gonzalez-Jimenez, J.M., Camprubi, A., Colas, V., Griffin, W.L., Proenza, J.A., O'Reilly, S.Y., Centeno-Garcia, El., Garcia-Casco, A., Belousova, E., Talavera, C., Farre-de-Pablo, J., Satsukawa, T.The recycling of chromitites in ophiolites from southwestern North America. ( Baja)Lithos, in press available, 52p.United States, Californiachromitites

Abstract: Podiform chromitites occur in mantle peridotites of the Late Triassic Puerto Nuevo Ophiolite, Baja California Sur State, Mexico. These are high-Cr chromitites [Cr# (Cr/Cr + Al atomic ratio = 0.61-0.69)] that contain a range of minor- and trace-elements and show whole-rock enrichment in IPGE (Os, Ir, Ru). That are similar to those of high-Cr ophiolitic chromitites crystallised from melts similar to high-Mg island-arc tholeiites (IAT) and boninites in supra-subduction-zone mantle wedges. Crystallisation of these chromitites from S-undersaturated melts is consistent with the presence of abundant inclusions of platinum-group minerals (PGM) such as laurite (RuS2)-erlichmanite (OsS2), osmium and irarsite (IrAsS) in chromite, that yield TMA ? TRD model ages peaking at ~ 325 Ma. Thirty-three xenocrystic zircons recovered from mineral concentrates of these chromitites yield ages (2263 ± 44 Ma to 278 ± 4 Ma) and Hf-O compositions [?Hf(t) = ? 18.7 to + 9.1 and 18O values < 12.4‰] that broadly match those of zircons reported in nearby exposed crustal blocks of southwestern North America. We interpret these chromitite zircons as remnants of partly digested continental crust or continent-derived sediments on oceanic crust delivered into the mantle via subduction. They were captured by the parental melts of the chromitites when the latter formed in a supra-subduction zone mantle wedge polluted with crustal material. In addition, the Puerto Nuevo chromites have clinopyroxene lamellae with preferred crystallographic orientation, which we interpret as evidence that chromitites have experienced high-temperature and ultra high-pressure conditions (< 12 GPa and ~ 1600 °C). We propose a tectonic scenario that involves the formation of chromitite in the supra-subduction zone mantle wedge underlying the Vizcaino intra-oceanic arc ca. 250 Ma ago, deep-mantle recycling, and subsequent diapiric exhumation in the intra-oceanic basin (the San Hipólito marginal sea) generated during an extensional stage of the Vizcaino intra-oceanic arc ca. 221 Ma ago. The TRD ages at ~ 325 Ma record a partial melting event in the mantle prior to the construction of the Vizcaino intra-oceanic arc, which is probably related to the Permian continental subduction, dated at ~ 311 Ma.
DS201706-1094
2017
Satsuskawa, T.Lu, J-G, Xiong, Q., Griffin, W.L., Zheng, J-P., Huang, J-X., O'Reilly, S.Y., Satsuskawa, T., Pearson, N.J.Uplift of the southeastern Australian lithosphere: thermal tectonic evolution of garnet pyroxenite xenoliths from western Victoria.Geological Society of America, SPE 526 pp. 27-48.Australiageothermometry

Abstract: Detailed petrography, microstructure, and geochemistry of garnet pyroxenite xenoliths in Holocene basanite tuffs from maars at Lakes Bullenmerri and Gnotuk (western Victoria, southeastern Australia) have been used to track their igneous and metamorphic history, enabling the reconstruction of the thermal-tectonic evolution of the lithospheric mantle. The exsolution of orthopyroxene and garnet and rare spinel, plagioclase, and ilmenite from complex clinopyroxene megacrysts suggests that the xenoliths originally were clinopyroxene-dominant cumulates associated with minor garnet, orthopyroxene, or spinel. The compositions of exsolved phases and their host clinopyroxene were reintegrated using measured modal proportions to show that the primary clinopyroxene was enriched in Al2O3 (5.53-13.63 wt%) and crystallized at ~1300-1500 °C and 16-30 kbar. These cumulates then underwent extensive exsolution, recrystallization, and reaction during cooling, and finally equilibrated at ~950-1100 °C and 12-18 kbar before entrainment in the basanites. Rare earth element (REE) thermobarometry of garnets and coexisting clinopyroxenes preserves evidence of an intermediate stage (1032 °C and 21 kbar). These results imply that the protoliths of the garnet pyroxenite formed at a range of depths from ~50 to 100 km, and then during or shortly after cooling, they were tectonically emplaced to higher levels (~40-60 km; i.e., uplifted by at least 10-20 km) along the prevailing geotherm. This uplift may have been connected with lithosphere-scale faulting during the Paleozoic orogeny, or during Mesozoic-Cenozoic rifting of eastern Australia.
DS202009-1635
2020
Satta, N.Koemets, I., Satta, N., Marquardt, H., Kiseeva, E.S., Kurnosov, A., Stachel, T., Harris, J.W., Dubrovinsky, L.Elastic properties of majorite garnet inclusions in diamonds and the seismic signature of pyroxenites in the Earth's upper mantle.American Mineralogist, Vol. 105, pp. 984-991. pdfMantlediamond inclusions

Abstract: Majoritic garnet has been predicted to be a major component of peridotite and eclogite in Earth's deep upper mantle (>250 km) and transition zone. The investigation of mineral inclusions in diamond confirms this prediction, but there is reported evidence of other majorite-bearing lithologies, intermediate between peridotitic and eclogitic, present in the mantle transition zone. If these lithologies are derived from olivine-free pyroxenites, then at mantle transition zone pressures majorite may form monomineralic or almost monomineralic garnetite layers. Since majoritic garnet is presumably the seismically fastest major phase in the lowermost upper mantle, the existence of such majorite layers might produce a detectable seismic signature. However, a test of this hypothesis is hampered by the absence of sound wave velocity measurements of majoritic garnets with relevant chemical compositions, since previous measurements have been mostly limited to synthetic majorite samples with relatively simple compositions. In an attempt to evaluate the seismic signature of a pyroxenitic garnet layer, we measured the sound wave velocities of three natural majoritic garnet inclusions in diamond by Brillouin spectroscopy at ambient conditions. The chosen natural garnets derive from depths between 220 and 470 km and are plausible candidates to have formed at the interface between peridotite and carbonated eclogite. They contain elevated amounts (12-30%) of ferric iron, possibly produced during redox reactions that form diamond from carbonate. Based on our data, we model the velocity and seismic impedance contrasts between a possible pyroxenitic garnet layer and the surrounding peridotitic mantle. For a mineral assemblage that would be stable at a depth of 350 km, the median formation depth of our samples, we found velocities in pyroxenite at ambient conditions to be higher by 1.9(6)% for shear waves and 3.3(5)% for compressional waves compared to peridotite (numbers in parentheses refer to uncertainties in the last given digit), and by 1.3(13)% for shear waves and 2.4(10)% for compressional waves compared to eclogite. As a result of increased density in the pyroxenitic layer, expected seismic impedance contrasts across the interface between the monomineralic majorite layer and the adjacent rocks are about 5-6% at the majorite-eclogite-interface and 10-12% at the majoriteperidotite-boundary. Given a large enough thickness of the garnetite layer, velocity and impedance differences of this magnitude could become seismologically detectable.
DS1994-1896
1994
Sattel, S.Weiller, M., Sattel, S., Jung, K., Ehrhardt, H.Is C(60) fullerite harder than diamondPhys. Lett. A., Vol. 188, No. 3, May 23, pp. 281-286.GlobalFullerite, Carbon
DS1940-0190
1948
Satterly, J.Satterly, J.Geology of Michaud TownshipOntario Department of Mines Geology Report, Vol. 57, PT. 4, P. 13.Canada, Ontario, MichaudBlank
DS1950-0106
1952
Satterly, J.Hogg, N., Satterly, J., Wilson, A.E.Drilling in the James Bay Lowland: Part 1, Drilling by the Ontario Government.Ontario Department of Mines Annual Report, Vol. 61, PT. 6, PP. 115-140.Canada, OntarioProspecting, Kimberlite
DS1970-0406
1971
Satterly, J.Satterly, J.Diamond: Ussr and North America, a Target for Exploration In Ontario.Ontario Department of Mines, NORTH. AFFAIRS, No. 48, 43P.Canada, United States, RussiaProspecting, Diamond Occurrences
DS2001-1017
2001
Saturday Night Magazine (Financial Post)Saturday Night Magazine (Financial Post)Turning killers into soldiers... Canadians in Sierra LeoneSat. Night Magazine, June 16, pp. 22-33.Sierra LeoneNews item, Conflict diamonds
DS1900-0290
1905
Saturday ReviewSaturday ReviewThe Diamond (1905)Saturday Review., Vol. 100, SEPT. 9TH. PP. 331-332.Africa, South AfricaDiamond Occurrence
DS1993-1145
1993
Satvaldiev, M.h.Novgorodova, M.I., Trubkin, N.V., Akhemedov, M.A., Satvaldiev, M.h.Inclusions of natrium fluoride and high alkaline silicate glasses in xenogene diamondgranitoids.(Russian)Proceedings of the Russian Mineralogical Society, (Russian), No. 1, pp. 88-95.RussiaDiamond morphology, Diamond inclusions
DS202108-1312
2021
Satyakumar, A.V.Vasanti, A., Singh, A.P., Kumar, N., Nageswara Rao, B., Satyakumar, A.V., Santosh, M.Crust-mantle structure and lithospheric destruction of the oldest craton in the Indian shield.Precambrian Research, Vol. 362, 16p. PdfIndiacraton

Abstract: The Singhbhum craton is among the five Archean cratons of Peninsular India that preserves some of the oldest continental nuclei. In this work, we present a new and complete Bouguer gravity map of this craton with insights into its deep crust-mantle structure, lithospheric thickness and density variations beneath this craton. The conspicuous presence of high-order residual gravity low anomalies, together with low estimated densities, suggests voluminous presence of Singhbhum granitic batholiths that built the dominant crustal architecture. The isolated residual gravity highs correspond to the mafic and ultramafic volcanic suites like, Dhanjori, Simlipal and Dalma, while the relatively low gravity anomalies observed over the western volcanic suites like Malangtoli, Jagannathpur and Ongarbira, indicate their relatively felsic nature. The estimated lithospheric thickness of about ~ 130 km below the granitic batholithic region, and about 112 km beneath the Precambrian volcanic terranes, together with low effective elastic thickness (Te,) of only about 31 km, suggest a thin and weak lithosphere. The craton witnessed extensive lithospheric destruction with the removal of nearly 100-150 km of the cratonic root. The decratonization may be linked to subduction during the Paleo-Mesoproterozoic period, together with mantle plumes at different times, suggesting a combined mechanical, thermal and chemical erosion of the cratonic keel.
DS1991-1499
1991
Satyanarayana, G.Satyanarayana, G.Quaternary geology and geomorphology of the area between Somasila andSangam, Nellore District, Andhra Pradesh.Records Geological Survey of India, Vol. 124, pt. 5, pp. 1-3.IndiaAlluvials, Diamonds
DS201806-1242
2018
Satyanarayana, H.V.Ravi Kumar, M., Singh, A., Bhaskar Rao, Y.J., Srijayanthi, G., Satyanarayana, H.V., Sarkar, D.Vestiges of Precambrian subduction in the south Indian shield? - A seismological perspective.Tectonophysics, Vol. 740-741, pp. 27-41.Indiageophysics - seismic

Abstract: Investigation of large scale suture zones in old continental interiors offers insights into the evolution of continents. The Dharwar Craton (DC) and the Southern Granulite Terrain(SGT) of the Indian shield represent large segments of Precambrian middle to lower crust and preserve a geological record spanning from Mesoarchean to Cambrian. This study illuminates the deep structure of the Palghat-Cauvery Shear Zone System (PCSS) and the Palghat-Cauvery Suture Zone (PCSZ) that comprise crustal-scale structures related to multiple episodes of orogeny, crust formation and reworking. We utilize here 3202 high quality P-receiver functions computed using new data from a 23 station seismic network operated by us. Results show a thick (>38?km) mafic (Poisson's ratio >0.25) crust beneath the SGT. The change in crustal thickness is gradual, with a shallower Moho towards the south of PCSZ. We found little evidence for drastic changes in crustal thickness across prominent shear zones like the PCSZ and Moyar-Bhavani. Few seismic stations located along these boundaries have shown evidence for dipping reflectors around 8-20?km depth, with strikes matching well with the trends of surface geological sutures. We opine that these suture zones do not show indications of a terrane boundary. However, a drastic change in the crustal thickness is observed around the prograde metamorphic transition zone or broadly, the "Fermor line", which separates rocks of Chanockitic (Orthopyroxene bearing granitoid) and non-Charnockitic (Orthopyroxene-free granitoid) mineral assemblage, further north beneath the DC. We suggest that thicknening of crust north of Moyar-Attur Shear Zone (MASZ) and around Fermor line is related to subduction processes operative during the Precambrian.
DS201808-1761
2018
Satyanarayana, H.V.Kumar, M.R., Singh, A., Bhaskar Rao, Y.J., Srijayanthi, G., Satyanarayana, H.V., Sarkar, D.Vestiges of Precambrian subduction in the south Indian shield? - a seismological perspective.Tectonophysics, Vol. 740-741, pp. 27-41.Indiageophysics - seismic

Abstract: Investigation of large scale suture zones in old continental interiors offers insights into the evolution of continents. The Dharwar Craton (DC) and the Southern Granulite Terrain(SGT) of the Indian shield represent large segments of Precambrian middle to lower crust and preserve a geological record spanning from Mesoarchean to Cambrian. This study illuminates the deep structure of the Palghat-Cauvery Shear Zone System (PCSS) and the Palghat-Cauvery Suture Zone (PCSZ) that comprise crustal-scale structures related to multiple episodes of orogeny, crust formation and reworking. We utilize here 3202 high quality P-receiver functions computed using new data from a 23 station seismic network operated by us. Results show a thick (>38?km) mafic (Poisson's ratio >0.25) crust beneath the SGT. The change in crustal thickness is gradual, with a shallower Moho towards the south of PCSZ. We found little evidence for drastic changes in crustal thickness across prominent shear zones like the PCSZ and Moyar-Bhavani. Few seismic stations located along these boundaries have shown evidence for dipping reflectors around 8-20?km depth, with strikes matching well with the trends of surface geological sutures. We opine that these suture zones do not show indications of a terrane boundary. However, a drastic change in the crustal thickness is observed around the prograde metamorphic transition zone or broadly, the “Fermor line”, which separates rocks of Chanockitic (Orthopyroxene bearing granitoid) and non-Charnockitic (Orthopyroxene-free granitoid) mineral assemblage, further north beneath the DC. We suggest that thicknening of crust north of Moyar-Attur Shear Zone (MASZ) and around Fermor line is related to subduction processes operative during the Precambrian.
DS201709-2045
2017
Satyanarayana, K.V.V.Radhakrishna, T., Soumya, G.S., Satyanarayana, K.V.V.Paleomagnetism of the Cretaceous lamproites from Gondwana basin of the Damodar Valley in India and migration of the Kerguelen plume in the southeast Indian Ocean.Journal of Geodynamics, Vol. 109, pp. 1-9.Indialamproites

Abstract: The paper presents new palaeomagnetic results and reassesses complete set of published palaeomagnetic results on the lamproite intrusions in the Gondwana formations of the Eastern India. Altogether eleven sites register reliable characteristic magnetisations corresponding to the c. 110 Ma emplacement age of the lamproites. A mean ChRM is estimated with D = 331.3°; I = ?62.4° (?95 = 6.2°, k = 55; N = 11). The palaeomagnetic pole of ? = 14.9°: ? = 287.6° (A95 = 8.4°) is established for the lamproites and it averaged the secular variation and confirms to the Geocentric Axial Dipole (GAD). The pole compares remarkably well with the grand mean pole reported for the Rajmahal traps that are attributed to represent location of the Kerguelen mantle plume head. The palaeolatitudes transferred to Rajmahal coordinates (25.05°: 87.84°) are situated ?6° north of the present location of the Kerguelen hotspot location. The interpretations are consistent with earlier suggestions of southward migration of the plume based on palaeomagnetic results of Site 1138 of the ODP Leg 183 and with the predictions of numerical models of global mantle circulation.
DS200612-1028
2005
Satyanarayana, M.Parijat Roy, Balaram, V., Satyanarayana, M., Kumar, A.Determination of trace and REE in kimberlite and related rocks by ICP-MS.Geological Society of India, Bangalore November Meeting Group Discussion on Kimberlites and Related Rocks India, Abstract p. 142.IndiaMineral chemistry, petrology
DS200612-1228
2005
Satyanarayana, S.V.Satyanarayana, S.V., Nayak, S.S.Ancient diamond mines vis a vis current exploration in India.Geological Society of India, Bangalore November Meeting Group Discussion on Kimberlites and Related Rocks India, Abstract p. 138-140.IndiaHistory, diamond exploration
DS200612-1229
2005
Satyanarayana, S.V.Satyanarayana, S.V., Nayak, S.S., Bhaskara Rao, K.S., Sivaji, K.Morphological characters of diamond from southern India.Geological Society of India, Bangalore November Meeting Group Discussion on Kimberlites and Related Rocks India, Abstract p. 80-84.India, Andhra Pradesh, Dharwar CratonDiamond morphology
DS200712-0877
2007
Satyanarayana, S.V.Ravi, S., Satyanarayana, S.V.Discovery of kimberlites in Chagapuram area, Mahaboobnagar District, Andhra Pradesh.Journal of the Geological Society of India, Vol. 70, 4, pp. 689-692.India, Andhra PradeshKimberlite exploration
DS1990-1515
1990
Satyanarayana, Y.Verma, R.K., Satyanarayana, Y.Gravity field, deep seismic sounding and crust -mantle structure over the Cuddapah basin and Dhawar Craton of IndiaTectonophysics, Vol. 178, No. 2-4, June 20, pp. 337-356IndiaGeophysics -seismics, Craton
DS1997-0999
1997
Satyanarayana, Y.Satyanarayana, Y., Chanchal, D., Murty, G.R.K.Profile: a microsoft quick basic program for retrieving dat a along a givenprofile from gridded dat aComputers and Geosciences, Vol. 23, No. 1, pp. 127-131GlobalComputers Program, Contour map
DS200712-0915
2007
Satyanarayanan, M.Roy, P., Balaram, V., Kumar, A., Satyanarayanan, M., Gnaneshwar Rao, ThotaNew REE and trace element dat a on two kimberlite reference materials by ICP-MS.Geostandards and Geoanalytical Research, Vol. 31, 3, pp. 261-273.TechnologyKimberlte trace elements
DS201012-0716
2010
Satyanarayanan, M.Singh, S.P., Balaram, V., Satyanarayanan, M., Anjaiah, K.V., Kharia, A.Platinum group elements in basic and ultrabasic rocks around Madawara Bundelk hand Massif, Central India.Current Science, Vol. 99, 3, August 16, 9p.IndiaPGE melting - not specific to diamonds
DS201012-0717
2010
Satyanarayanan, M.Singh, S.P., Balaram, V., Satyanarayanan, M., Anjaiah, K.V., Kharia, A.Platinum group elements in basic and ultrabasic rocks around Madawara Bundelk hand Massif, Central India.Current Science, Vol. 99, 3, August 16, 9p.IndiaPGE melting - not specific to diamonds
DS201712-2699
2017
Satyanarayanan, M.Khanna, T.C., Subba Rao, D.V., Bizimis, M., Satyanarayanan, M., Krishna, A.K., SeshaSai, V.V.~2.1 Ga intraoceanic magmatism in the central India tectonic zone: constraints from the petrogenesis of ferropicrites in the Mahakoshal suprarcustal belt.Precambrian Research, Vol. 302, pp. 1-17.Indiapicrites
DS201808-1786
2018
Satyanarayanan, M.Satyanarayanan, M., Subba Rao, D.V., Renjith, M.L., Singh, S.P., Babu, E.V.S.S.K., Korakoppa, M.M.Petrogenesis of carbonatitic lamproitic dykes from Sidhi gneissic complex, central India.Geoscience Frontiers, Vol. 9, 2, pp. 531-547.Indialamproite

Abstract: Petrographic, mineral chemical and whole-rock geochemical characteristics of two newly discovered lamproitic dykes (Dyke 1 and Dyke 2) from the Sidhi Gneissic Complex (SGC), Central India are presented here. Both these dykes have almost similar sequence of mineral-textural patterns indicative of: (1) an early cumulate forming event in a deeper magma chamber where megacrystic/large size phenocrysts of phlogopites have crystallized along with subordinate amount of olivine and clinopyroxene; (2) crystallization at shallow crustal levels promoted fine-grained phlogopite, K-feldspar, calcite and Fe-Ti oxides in the groundmass; (3) dyke emplacement related quench texture (plumose K-feldspar, acicular phlogopites) and finally (4) post emplacement autometasomatism by hydrothermal fluids which percolated as micro-veins and altered the mafic phases. Phlogopite phenocrysts often display resorption textures together with growth zoning indicating that during their crystallization equilibrium at the crystal-melt interface fluctuated multiple times probably due to incremental addition or chaotic dynamic self mixing of the lamproitic magma. Carbonate aggregates as late stage melt segregation are common in both these dykes, however their micro-xenolithic forms suggest that assimilation with a plutonic carbonatite body also played a key role in enhancing the carbonatitic nature of these dykes. Geochemically both dykes are ultrapotassic (K2O/Na2O: 3.0 -9.4) with low CaO, Al2O3 and Na2O content and high SiO2 (53.3 -55.6 wt.%) and K2O/Al2O3 ratio (0.51 -0.89) characterizing them as high-silica lamproites. Inspite of these similarities, many other features indicate that both these dykes have evolved independently from two distinct magmas. In dyke 1, phlogopite composition has evolved towards the minette trend (Al-enrichment) from a differentiated parental magma having low MgO, Ni and Cr content; whereas in dyke 2, phlogopite composition shows an evolutionary affinity towards the lamproite trend (Al-depletion) and crystallized from a more primitive magma having high MgO, Ni and Cr content. Whole-rock trace-elements signatures like enriched LREE, LILE, negative Nb-Ta and positive Pb anomalies; high Rb/Sr, Th/La, Ba/Nb, and low Ba/Rb, Sm/La, Nb/U ratios in both dykes indicate that their parental magmas were sourced from a subduction modified garnet facies mantle containing phlogopite. From various evidences it is proposed that the petrogenesis of studied lamproitic dykes stand out to be an example for the lamproite magma which attained a carbonatitic character and undergone diverse chemical evolution in response to parental melt composition, storage at deep crustal level and autometasomatism.
DS201908-1793
2019
Satyanarayanan, M.Mohanty, N., Singh, S.P., Satyanarayanan, M., Jayananda, M., Korakoppa, M.M., Hiloidari, S.Chromianspinel compositions from Madawara ultramafics, Bundelkhand craton: implications on petrogenesis and tectonic evolution of the southern part of the Bundelkhand craton, central India.Geological Journal, Vol. 54, 4, pp. 2099-2123.Indiacraton

Abstract: Madawara ultramafic complex (MUC) in the southern part of Bundelkhand Craton, Central India comprises peridotite, olivine pyroxenite, pyroxenite, gabbro, and diorite. Coarse?grained olivine, clinopyroxene (Cpx), amphibole (Amp), Al?chromite, Fe?chromite, and magnetite with rare orthopyroxene (Opx) are common minerals in peridotite. Chromites are usually coarse?grained euhedral found as disseminated crystals in the olivine matrix showing both homogeneous and zoned texture. Al?chromite, primarily characterizes Cr?spinels and its subsequent fluid activity and alteration can result in the formation of Fe?chromite, chrome magnetite, and magnetite. Mineral chemistry data suggest that Al?chromite is characterized by moderately high Cr2O3 (38.16-51.52 wt.%) and Fe2O3 (3.22-14.51 wt.%) and low Al2O3 (10.63-21.87 wt.%), MgO (1.71-4.92 wt.%), and TiO2 (0.22-0.67 wt.%), whereas the homogeneous Fe?chromite type is characterized by high Fe2O3 (25.54-47.60 wt.%), moderately low Cr2O3 (19.56-37.90 wt.%), and very low Al2O3 (0.06-1.53 wt.%). Subsequent alteration of Al?chromite and Fe?chromite leads to formation of Cr?magnetite and magnetite. The Cr# of Al?chromite varies from 55.12 to 76.48 and ?Fe3+# from 8 to 19, whereas the ferrian chromite has high Cr# varying from 94.27 to 99.53 while its ?Fe3+# varies from 38 to 70. As a whole, the primary Al?chromite shows low Al2O3, TiO2 contents, and high Fe#, Cr# values. Olivines have forsterite ranging from 75.96% to 77.59%. The bulk?rock geochemistry shows continental arc geochemical affinities indicated by the high concentration of large?ion lithophile elements and U, Th relative to the low concentration of high?field strength elements. These petrological and mineralogical as well as primary Al?chromite compositions plotted in different discrimination diagrams suggest an arc environment that is similar to Alaskan?type intrusion.
DS1992-1609
1992
Satyanaryana, S.V.Viswanathan, T.V., Satyanaryana, S.V.Geological setting of Diamondiferous primary and secondary rocks in AndhraPradesh.International Roundtable Conference on Diamond Exploration and Mining, held, pp. 209-211.IndiaGeology, Deposits
DS1985-0229
1985
Satykov, A.J.Genshaff, I.S., Satykov, A.J.The Kimberlite Type of Inclusions in Alkaline Basalts of The Dariganga Plateau.Doklady Academy of Sciences AKAD. NAUK SSR., Vol. 282, No. 5, PP. 1200-1205.RussiaPetrography
DS201012-0650
2010
Satynarayanan, M.Saha, L., Pant, N.C., Pati, J.K., Upadhyay, D., Berndt, J., Bhattacharya, A., Satynarayanan, M.Neoarchean high pressure margarite phengite muscovite chlorite corona mantle corundum in quartz free high Mg, Al phlogopite chlorite schists from the BundelkhandContributions to Mineralogy and Petrology, in press available, 20p.IndiaCraton, U H metamorphism
DS1993-1378
1993
Sauchyn, D.J.Sauchyn, D.J.Quaternary and Late Tertiary landscapes of southwestern Saskatchewan and adjacent areas. Field Guide.Canadian Press Research Center, University of Regina, Saskatchewan S4S O42 Payable, 114p. $26.00SaskatchewanGlacial deposits, Geomorphology
DS200912-0546
2009
Saucier, F.O'Driscoll, L.J., Humphreys, E.D., Saucier, F.Subduction adjacent to deep continental roots: enhanced negative pressure in the mantle wedge, mountain building and continental motion.Earth and Planetary Science Letters, Vol. 280, 1-4, Apr. 15, pp. 61-70.MantleSubduction
DS1991-1500
1991
Saucier, R.T.Saucier, R.T.Geoarchaeological evidence of strong prehistoric earthquakes in the New Madrid (Missouri) seismic zoneGeology, Vol. 19, No. 4, April pp. 296-298MissouriGeophysics -seismics, Geoarchaeology
DS1930-0263
1937
Sauer, H.Sauer, H.Ex AfricaLondon: G. Bliss, 335P.South AfricaKimberley, Janlib, History
DS1982-0537
1982
Sauer, J.R.Sauer, J.R.Brasil: Paradise of GemstonesJewellers Circular Keystone, Vol. 154, No. 10, OCTOBER P. 190.BrazilGemstones, Kimberley, Diamonds
DS1910-0375
1913
Saueracker, K.Saueracker, K.Statistik des Berg und Huttenwesens. Versuch Einer Einheitlichen Regelung. Eine Anregung von Dr. K. Saueracker.Berlin: Fachliteratur, G.m.b.h., 287P.Southwest Africa, NamibiaMineral Resources, Statistics, Diamonds
DS2001-0486
2001
Saul, B.Holubec, I., Saul, B.Mine waste management strategy at Diavik Diamonds mine29th. Yellowknife Geoscience Forum, Nov. 21-23, abstract p. 30-1.Northwest TerritoriesMine waste - environment, tailings, Deposit - Diavik
DS2000-0856
2000
Saul, J.Saul, J., Kumar, M.R., Sarkar, D.Lithospheric and upper mantle structure of Indian Shield, from teleseismic receiver functions.Geophysical Research Letters, Vol. 27, No. 16, Aug. 15, pp.2357-60.IndiaCraton, Geophysics - seismics
DS2001-0968
2001
Saul, J.Ravi Kama, M., Saul, J., Shukla, A.K.Crustal structure of the Indian Shield: new constraints from teleseismic receiver functions.Geophysical Research Letters, Vol. 28, No. 7, April 1, pp.1339-42.IndiaTectonics, shield, Geophysics - seismics
DS2002-0850
2002
Saul, J.Kind, R., Yuan, X., Saul, J., Nelson, D., Sobolev, S.V., Mechie, J., Zhao, W.Seismic images of crust and upper mantle beneath Tibet: evidence for Eurasian plateScience, No. 5596, pp. 1219-1221.Mantle, ChinaGeophysics - seismics
DS2002-0905
2002
Saul, J.Kumar, M.R., Ramesh, D.S., Saul, J., Sarker, D., Kind, R.Crustal structure and upper mantle stratigraphy of the Arabian ShieldGeophysical Research Letters, Vol. 89, No. 8, April 15, pp. 83-Arabian Shield, North AfricaTectonics
DS2003-1212
2003
Saul, J.Sarkar, D., Kumar, M.R., Saul, J., Kind, R., Raju, P.S., Chadha, R.K., ShuklaA receiver function perspective of the Dharwar craton ( India) crustal structureGeophysical Journal International, No. 154, 1, pp. 205-211.IndiaBlank
DS2003-1215
2003
Saul, J.Saul, J., Vinick, L., Wookey, J., Kendall, J.M., Barruol, G.Mantle deformation or processing artefact?Nature, No. 6928, March 13, p. 136.MantleTectonics
DS200412-1731
2003
Saul, J.Sarkar, D., Kumar, M.R., Saul, J., Kind, R., Raju, P.S., Chadha, R.K., Shukla, A.K.A receiver function perspective of the Dharwar craton ( India) crustal structure.Geophysical Journal International, No. 154, 1, pp. 205-211.IndiaGeophysics - seismics
DS200512-0588
2004
Saul, J.Kumar, M.R., Raju, P.S., Devi, E.U., Saul, J., Ramesh, D.S.Crustal structure variations in northeast India from converted phases.Geophysical Research Letters, Vol. 31, 17, Sept. 16, L17605IndiaTectonics
DS1981-0365
1981
Saul, J.M.Saul, J.M.The Origin of Diamonds and the Deep Gas HypothesisJournal of GEMMOLOGICAL SOCIETY of JAPAN., Vol. 8, No. 1-8, PP.GlobalBlank
DS1985-0587
1985
Saul, S.Saul, S., Stern, C.R.Relation between Spinel and Garnet Lherzolites from the Pali; Aike Volcanic Field South America.Eos, Vol. 66, No. 18, APRIL 30TH. P. 393. (abstract.).South AmericaGeothermometry}i
DS1986-0783
1986
Saul, S.Stern, C.R., Futa, K., Saul, S., Skewes, M.A.Nature and evolution of the subcontinental mantle lithosphere below southern South America And implications for Andean magma genesisRevista Geologica de Chile, No. 27, pp. 41-53South AmericaPali-Aike basalts, lherzolites, peridotite xenoliths, Lithosphere cross section
DS1986-0784
1986
Saul, S.Stern, C.R., Futa, K., Saul, S., Skewes, M.A.Ultramafic xenoliths from the Palo-Aike basalts: Implications for the nature and evolution of the subcontinental lithosphere below southern SouthAmericaProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 343-345South America, PatagoniaBlank
DS1989-1454
1989
Saul, S.Stern, C.R., Saul, S., Skewes, M.A., Futa, K.Garnet peridotite xenoliths from the Pali-Aike basalts of southernmost South AmericaGeological Society of Australia Inc. Blackwell Scientific Publishing, Special, No. 14, Vol. 2, pp. 735-744South America, Argentina, ChilePetrochemistry, Pali-Aike
DS1987-0161
1987
Saul, S.L.Douglas, B.J., Saul, S.L., Stern, C.R.Rheology of the upper mantle beneath the Southern most South America inferred from peridotite xenolithsJournal of Geology, Vol. 95, No.2, March pp. 241-254South AmericaMantle genesis
DS1960-0693
1966
Saull, V.A.Kumapareli, P.S., Saull, V.A.The St. Lawrence Valley System: a North American Equivalent of the East African Rift Valley SystemCanadian Journal of Earth Sciences, Vol. 3, PP. 639-658.CanadaGeotectonics
DS1960-0744
1966
Saull, V.A.Saull, V.A., Kumarapeli, P.S.The St. Lawrence Valley System, a North American Equivalent of the East African Rift Valley SystemCanadian Journal of Earth Sciences, Vol. 3, No. 5, PP. 639-658.GlobalMid-continent
DS200912-0668
2009
Saumet, S.Saumet, S., Bascou, J., Ionov, D., Doucet, L.Seismic properties of the Siberian craton mantle from Udachnaya xenoliths.Goldschmidt Conference 2009, p. A1160 Abstract.Russia, SiberiaDeposit - Udachnaya
DS201112-0063
2011
Saumet, S.Bascou, J., Doucet, L.S., Saumet, S., Ionov, D.A., Ashchepkov, I.V., Golovin, A.V.Seismic velocities, anisotropy and deformation in Siberian cratonic mantle: EBSD dat a on xenoliths from the Udachnaya kimberlite.Earth and Planetary Science Letters, Vol. 304, 1-2, pp. 71-84.RussiaDeposit - Udachnaya
DS202108-1274
2021
Saumor, B.M.Bedard, J.H., Troll, V.R., Deegan, F.M., Tegner, C., Saumor, B.M., Evenchick, C.A., Grasby, S.E., Dewing, K.High arctic large igneous province alkaline rocks in Canada: evidence for multiple mantle components.Journal of Petrology, 113p. PdfCanada, Ellesmere Islandalkaline rocks

Abstract: The Cretaceous High Arctic Large Igneous Province (HALIP) in Canada, although dominated by tholeiites (135-90?Ma), contains two main groups of alkaline igneous rocks. The older alkaline rocks (?96?Ma) scatter around major fault and basement structures. They are represented by the newly-defined Fulmar Suite alkaline basalt dykes and sills, and include Hassel Formation volcanics. The younger alkaline group is represented by the Wootton Intrusive Complex (92.2-92.7?Ma), and the Audhild Bay Suite (83-73?Ma); both emplaced near the northern coast of Ellesmere Island. Fulmar Suite rocks resemble EM-type ocean island basalts (OIB) and most show limited crustal contamination. The Fulmar Suite shows increases of P2O5 at near-constant Ba-K-Zr-Ti that are nearly orthogonal to predicted fractionation- or melting-related variations; which we interpret as the result of melting composite mantle sources containing a regionally widespread apatite-bearing enriched component (P1). Low-P2O5 Fulmar Suite variants overlap compositionally with enriched HALIP tholeiites, and fall on common garnet lherzolite trace element melting trajectories, suggesting variable degrees of melting of a geochemically similar source. High-P2O5 Hassel Formation basalts are unusual among Fulmar rocks, because they are strongly contaminated with depleted lower crust; and because they involve a high-P2O5-Ba-Eu mantle component (P2), similar to that seen in alkali basalt dykes from Greenland. The P2 component may have contained Ba-Eu-rich hawthorneite and/or carbonate minerals as well as apatite, and may typify parts of the Greenlandic sub-continental lithospheric mantle (SCLM). Mafic alkaline Audhild Bay Suite (ABS) rocks are volcanic and hypabyssal basanites, alkaline basalts and trachy-andesites, and resemble HIMU ocean island basalts in having high Nb, low Zr/Nb and low 87Sr/86Sri. These mafic alkaline rocks are associated with felsic alkaline lavas and syenitic intrusions, but crustally-derived rhyodacites and rhyolites also exist. The Wootton Intrusive Complex (WIC) contains geochemically similar plutonic rocks (alkali gabbros, diorites and anatectic granites), and may represent a more deeply eroded, slightly older equivalent of the ABS. Low-P2O5 ABS and WIC alkaline mafic rocks have flat heavy rare-earth (HREE) profiles suggesting shallow mantle melting; whereas High-P2O5 variants have steep HREE profiles indicating deeper separation from garnet-bearing residues. Some High-P2O5 mafic ABS rocks seem to contain the P1 and P2 components identified in Fulmar-Hassel rocks, whereas other samples trend towards possible High-P2O5+Zr (PZr) and High-P2O5+K2O (PK) components. We argue that the strongly alkaline northern Ellesmere Island magmas sampled mineralogically heterogeneous veins or metasomes in Greenlandic-type SCLM, which contained trace phases like apatite, carbonates, hawthorneite, zircon, mica or richterite. The geographically more widespread apatite-bearing component (P1), could have formed part of a heterogeneous plume or upwelling mantle current that also generated HALIP tholeiites when melted more extensively, but may also have resided in the SCLM as relics of older events. Rare HALIP alkaline rocks with high K-Rb-U-Th fall on mixing paths implying strong local contamination from either Sverdrup Basin sedimentary rocks or granitic upper crust. However, the scarcity of potassic alkaline HALIP facies, together with the other trace element and isotopic signatures, provide little support for an ubiquitous fossil sedimentary subduction zone component in the HALIP mantle source.
DS202111-1757
2021
Saumur, B.M.Bedard, J.H., Troll, V,R., Deegan, F.M., Tegner, C., Saumur, B.M., Evenchick, C.A., Grasby, S.E., Dewing, K.High Arctic large igneous province alkaline rocks in Canada: evidence for multiple mantle components.Journal of Petrology, Vol. 62, 9, pp. 1-31. pdfCanada, Ellesmere Islandalkaline rocks

Abstract: The Cretaceous High Arctic Large Igneous Province (HALIP) in Canada, although dominated by tholeiites (135-90?Ma), contains two main groups of alkaline igneous rocks. The older alkaline rocks (?96?Ma) scatter around major fault and basement structures. They are represented by the newly defined Fulmar Suite alkaline basalt dykes and sills, and include Hassel Formation volcanic rocks. The younger alkaline group is represented by the Wootton Intrusive Complex (92•2-92•7?Ma), and the Audhild Bay Suite (83-73?Ma), both emplaced near the northern coast of Ellesmere Island. Fulmar Suite rocks resemble EM-type ocean island basalts (OIB) and most show limited crustal contamination. The Fulmar Suite shows increases of P2O5 at near-constant Ba-K-Zr-Ti that are nearly orthogonal to predicted fractionation- or melting-related variations, which we interpret as the result of melting composite mantle sources containing a regionally widespread apatite-bearing enriched component (P1). Low-P2O5 Fulmar Suite variants overlap compositionally with enriched HALIP tholeiites, and fall on common garnet lherzolite trace element melting trajectories, suggesting variable degrees of melting of a geochemically similar source. High-P2O5 Hassel Formation basalts are unusual among Fulmar rocks, because they are strongly contaminated with depleted lower crust; and because they involve a high-P2O5-Ba-Eu mantle component (P2), similar to that seen in alkali basalt dykes from Greenland. The P2 component may have contained Ba-Eu-rich hawthorneite and/or carbonate minerals as well as apatite, and may typify parts of the Greenlandic sub-continental lithospheric mantle (SCLM). Mafic alkaline Audhild Bay Suite (ABS) rocks are volcanic and hypabyssal basanites, alkaline basalts and trachy-andesites, and resemble HIMU ocean island basalts in having high Nb, low Zr/Nb and low 87Sr/86Sri. These mafic alkaline rocks are associated with felsic alkaline lavas and syenitic intrusions, but crustally derived rhyodacites and rhyolites also exist. The Wootton Intrusive Complex (WIC) contains geochemically similar plutonic rocks (alkali gabbros, diorites and anatectic granites), and may represent a more deeply eroded, slightly older equivalent of the ABS. Low-P2O5 ABS and WIC alkaline mafic rocks have flat heavy rare earth element (HREE) profiles suggesting shallow mantle melting; whereas High-P2O5 variants have steep HREE profiles indicating deeper separation from garnet-bearing residues. Some High-P2O5 mafic ABS rocks seem to contain the P1 and P2 components identified in Fulmar-Hassel rocks, whereas other samples trend towards possible High-P2O5 + Zr (PZr) and High-P2O5 + K2O (PK) components. We argue that the strongly alkaline northern Ellesmere Island magmas sampled mineralogically heterogeneous veins or metasomes in Greenlandic-type SCLM, which contained trace phases such as apatite, carbonates, hawthorneite, zircon, mica or richterite. The geographically more widespread apatite-bearing component (P1) could have formed part of a heterogeneous plume or upwelling mantle current that also generated HALIP tholeiites when melted more extensively, but may also have resided in the SCLM as relics of older events. Rare HALIP alkaline rocks with high K-Rb-U-Th fall on mixing paths implying strong local contamination from either Sverdrup Basin sedimentary rocks or granitic upper crust. However, the scarcity of potassic alkaline HALIP facies, together with the other trace element and isotopic signatures, provides little support for a ubiquitous fossil sedimentary subduction-zone component in the HALIP mantle source.
DS1998-0085
1998
SaundersBarry, T.L., Kempton, Saunders, WindleyMantle dynamics beneath Mongolia: implications for Cenozoic and Mesozoic alkalic basalts.Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 122-3.GlobalGeodynamics, volcanism.
DS1980-0299
1980
Saunders, A.D.Saunders, A.D., Tarney, J., Weaver, S.D.Transverse geochemical variations across the Antarctic Peninsula:implications for the genesis of calc alkaline magmas.Earth and Planetary Science Letters, Vol. 46, pp. 344-60.AntarcticaAlkaline Rocks, Geochemistry
DS1988-0610
1988
Saunders, A.D.Saunders, A.D., Norry, M.J., Tarney, J.Origin of Mid Ocean Ridge Basalt (MORB) and chemically depleted mantlereservoirs: trace elementconstraintsJournal of Petrology, Special Volume 1988- Oceanic and Continental, pp. 415-445GlobalMantle, Geochemistry
DS1989-1459
1989
Saunders, A.D.Storey, M., Rogers, G., Saunders, A.D., Terrell, D.J.San Quintin volcanic field, Baja California, Mexico:within plate magmatism following ridge subductionTerra Nova, Vol. 1, No. 2, pp. 195-202CaliforniaLherzolite, Mantle
DS1991-0725
1991
Saunders, A.D.Hole, M.J., Rogers, G., Saunders, A.D., Storey, M.Relation between alkalic volcanism and slab-window formationGeology, Vol. 19, No. 6, June pp. 657-660California, British ColumbiaAlkalic volcanism., Tectonics, Geochemistry
DS1991-1501
1991
Saunders, A.D.Saunders, A.D., Norry, M.J., Tarney, J.Fluid influence on the trace element compositions of subduction zonemagmasPhil. Transactions R. Soc. London, Sect. A., Vol. 335, pp. 377-392GlobalTectonics, Geochemistry - trace elements
DS1992-0839
1992
Saunders, A.D.Kent, R.W., Ghose, N.C., Paul, P.R., Hassan, M.J., Saunders, A.D.Coal-magma interaction: an integrated model for the emplacement of cylindrical intrusionsGeological Magazine, Vol. 129, No. 6, pp. 753-762IndiaLamproite, Magmas
DS1992-0840
1992
Saunders, A.D.Kent, R.W., Storey, M., Saunders, A.D., Kempton, P.D.Petrogenesis of Rajmahal continental flood basalts and associatedlamproites, northeast India: chemical and isotopic constraintsEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p.328IndiaLamproites, Geochemistry, geochronology
DS1992-1331
1992
Saunders, A.D.Saunders, A.D., Storey, M., Kent, R.W., Norry, M.J.Consequences of plume-lithosphere interactionsGeological Society Special Publication, Magmatism and the Causes of, No. 68, pp. 41-60GlobalMantle, Java Plateau, Plumes
DS1992-1332
1992
Saunders, A.D.Saunders, A.D., Storey, M., Kent, R.W., Norry, M.J.Consequences of plume-lithosphere interactionsGeological Society Special Publication, Magmatism and the Causes of Continental, No. 68, pp. 41-60.GlobalMantle, Plumes
DS1995-0814
1995
Saunders, A.D.Hole, M.J., Saunders, A.D., Rogers, G., Sykes, M.A.The relationship between alkaline magmatism, lithospheric extension and slab window formation...Geological Society of London Special Paper, Volcanism Association extension consuming, No. 81, pp. 265-285.AntarcticaPlate margins, Slab subduction
DS1995-0940
1995
Saunders, A.D.Kerr, A.C., Saunders, A.D., Tarney, J., Berry, N.H., Hards, V.L.Depleted mantle plume geochemical signatures: no paradox for plumetheoriesGeology, Vol. 23, No. 9, Sept. pp. 843-846MantlePlumes, Geochemistry
DS1996-0642
1996
Saunders, A.D.Hole, M.J., Saunders, A.D.The generation of small melt fractions in truncated melt columns:constraints from magma above slab windowsMineralogical Magazine, Vol. 60, No. 1, Feb pp. 173-190GlobalMagmatic processes, Slab windows, subduction
DS1996-1252
1996
Saunders, A.D.Saunders, A.D., Tarney, J., Kent, R.W.The formation and fate of large oceanic igneous provincesLithos, Vol. 37, No. 2/3, April pp. 81-96GlobalIgneous, Basalts
DS2003-0077
2003
Saunders, A.D.Barry, T.L., Saunders, A.D., Kempton, P.D., Windley, B.F., Pringle, M.S.Petrogenesis of Cenozoic basalts from Mongolia: evidence for the role ofJournal of Petrology, Vol. 44, 1, pp. 55-92.MongoliaMantle - metasomatism
DS201112-0301
2011
Saunders, C.Enders, M.S., Saunders, C.Discovery, innovation, and learning in the mining business - new ways forward for an old industry.SEG Newsletter, No. 86, July pp. 1, 16-31.GlobalEconomics - new business models, exploration
DS1975-0398
1976
Saunders, D.F.Saunders, D.F.Regional Lineament Map of the United StatesTexas Instruments Incorp., 1: 2, 500, 000.GlobalMid-continent
DS1975-0399
1976
Saunders, D.F.Saunders, D.F.Regional Geomorphic Lineaments on Satellite Imagery-their Origin and Applications.Proceedings SECOND International CONFERENCE ON BASEMENT TECTONICS, No. 2, PP. 326- 352.GlobalMid-continent
DS1975-0400
1976
Saunders, D.F.Saunders, D.F.Regional line manets on Stellite Imagery - their Origin and ApplicationsProceedings Second International Conference Basement Tectonics, pp. 326-52.United States, CanadaRemote Sensing - Lineaments, Structure
DS1860-1006
1897
Saunders, H.P.Saunders, H.P.Bibliography of South African Geology Parts 1, 2Cape Town Geol. Comm., 56P.Africa, South AfricaBibliography
DS202008-1396
2020
Saunders, J.E.Gonzales-Jiminez, J.M., Tassara, S., Schettino, E., Roque-Rosell, J., Farre-de-Pablo, J., Saunders, J.E., Deditius, A.P., Colas, V., Rovira-Medina, J.J., Guadalupe Davalos, M., Schilling, M., Jiminez-Franco, A., Marchesi, C., Nieto, F., Proenza, J.A., GerMineralogy of the HSE in the subcontinental lithospheric mantle - an interpretive review.Lithos, in press available, 44p. PdfMantleHSE

Abstract: The highly siderophile elements (HSE: Os, Ir, Ru, Rh, Pt, Pd, Re, Au) exist in solid solution in accessory base-metal sulfides (BMS) as well as nano-to-micron scale minerals in rocks of the subcontinental lithospheric mantle (SCLM). The latter include platinum-group minerals (PGM) and gold minerals, which may vary widely in morphology, composition and distribution. The PGM form isolated grains often associated with larger BMS hosted in residual olivine, located at interstices in between peridotite-forming minerals or more commonly in association with metasomatic minerals (pyroxenes, carbonates, phosphates) and silicate glasses in some peridotite xenoliths. The PGM found inside residual olivine are mainly Os-, Ir- and Ru-rich sulfides and alloys. In contrast, those associated with metasomatic minerals or silicate glasses of peridotite xenoliths consist of Pt, Pd, and Rh bonded with semimetals like As, Te, Bi, and Sn. Nanoscale observations on natural samples along with the results of recent experiments indicate that nucleation of PGM is mainly related with the uptake of HSE by nanoparticles, nanominerals or nanomelts at high temperature (> 900?°C) in both silicate and/or sulfide melts, regardless of the residual or metasomatic origin of their host minerals. A similar interpretation can be assumed for gold minerals. Our observations highlight that nanoscale processes play an important role on the ore-forming potential of primitive mantle-derived magmas parental to magmatic-hydrothermal deposits enriched in noble metals. The metal inventory in these magmas could be related with the physical incorporation of HSE-bearing nanoparticles or nanomelts during processes of partial melting of mantle peridotite and melt migration from the mantle to overlying continental crust.
DS201603-0381
2016
Saunders, M.Griffin, W.L., Gain, S.E.M., Adams, D., Huang, J-X., Saunders, M.,Toledo, V., Pearson, N.J., O'Reilly, S.Y.Heaven on Earth: tistarite ( Ti203) and other nebular phases in corundum aggregates from Mt. Carmel volcanic rocks.Israel Geological Society, pp. 85-86. abstractEurope, IsraelMoissanite

Abstract: This ending talk, focused on the ongoing cooperative research of Prof. Griffin and his team at Macquarie University and Shefa Yamim, since January 2014, highlighting unique corundum species characteristics. Preliminary results of this research were presented in the IGS Annual Meeting of 2015, whereas this year Prof. Griffin has shared innovative findings only microscopically tracked within titanium-rich corundum aggregates. One of the more abundant minerals is Tistarite (Ti2O3), previously known only as a single grain in a primitive type of meteorite (!). An article has been submitted to a scientific journal detailing this first terrestrial occurrence. Several other minerals are common in meteorites, but unknown or extremely rare on Earth. About half of these minerals are unknown to science, and will be described as new minerals in the scientific literature. The first of these is a Titanium-Aluminium-Zirconium oxide, informally known as TAZ; it will be submitted to the International Mineralogical Association for recognition as a new mineral, ShefaTAZite. Using state of the art technologies such as Thermal Ionisation Mass Spectrometry (TIMS) and Electron Microscopy Facility (EMF) that has three scanning electron microscopes, all with EBSD capability, and a transmission electron microscope - Prof. Griffin revealed spectacular imagery of minerals and rare compounds associated with titanium rich corundum aggregates.
DS201610-1865
2016
Saunders, M.Griffin, W.L., Gain, S.E.M., Adams, D.T., Huang, J-X., Saunders, M., Toledo, V., Pearson, N.J., O'Reilly, S.Y.First terrestrial occurrence of tistarite ( Ti2O3): ultra-low oxygen fugacity in the upper mantle beneath Mount Carmel, Israel.Geology, Vol. 44, 10, pp. 815-818.Europe, IsraelMoissanite

Abstract: The minimum oxygen fugacity (fO2) of Earth's upper mantle probably is controlled by metal saturation, as defined by the iron-wüstite (IW) buffer reaction (FeO ? Fe + O). However, the widespread occurrence of moissanite (SiC) in kimberlites, and a suite of super-reduced minerals (SiC, alloys, native elements) in peridotites in Tibet and the Polar Urals (Russia), suggest that more reducing conditions (fO2 = 6-8 log units below IW) must occur locally in the mantle. We describe pockets of melt trapped in aggregates of corundum crystals ejected from Cretaceous volcanoes in northern Israel which contain high-temperature mineral assemblages requiring extremely low fO2 (IW < -10). One abundant phase is tistarite (Ti2O3), previously known as a single grain in the Allende carbonaceous chondrite (Mexico) and believed to have formed during the early evolution of the solar nebula. It is associated with other reduced phases usually found in meteorites. The development of super-reducing conditions in Earth's upper mantle may reflect the introduction of CH4 + H2 fluids from the deep mantle, specifically related to deep-seated volcanic plumbing systems at plate boundaries.
DS201902-0275
2018
Saunders, M.Griffin, W.L., Gain, S.E.M., Bindi, L., Toledo, V., Camara, F., Saunders, M., O'Reilly, S.Y.Carmeltazite, ZrAl2Ti4011, a new mineral trapped in corundum from volcanic rocks of Mt Carmel, northern Israel.Minerals ( mdpi.com), Vol. 8, 12, 11p. PdfEurope, Israelmineralogy

Abstract: The new mineral species carmeltazite, ideally ZrAl2Ti4O11, was discovered in pockets of trapped melt interstitial to, or included in, corundum xenocrysts from the Cretaceous Mt Carmel volcanics of northern Israel, associated with corundum, tistarite, anorthite, osbornite, an unnamed REE (Rare Earth Element) phase, in a Ca-Mg-Al-Si-O glass. In reflected light, carmeltazite is weakly to moderately bireflectant and weakly pleochroic from dark brown to dark green. Internal reflections are absent. Under crossed polars, the mineral is anisotropic, without characteristic rotation tints. Reflectance values for the four COM wavelengths (Rmin, Rmax (%) (? in nm)) are: 21.8, 22.9 (471.1); 21.0, 21.6 (548.3), 19.9, 20.7 (586.6); and 18.5, 19.8 (652.3). Electron microprobe analysis (average of eight spot analyses) gave, on the basis of 11 oxygen atoms per formula unit and assuming all Ti and Sc as trivalent, the chemical formula (Ti3+3.60Al1.89Zr1.04Mg0.24Si0.13Sc0.06Ca0.05Y0.02Hf0.01)?=7.04O11. The simplified formula is ZrAl2Ti4O11, which requires ZrO2 24.03, Al2O3 19.88, and Ti2O3 56.09, totaling 100.00 wt %. The main diffraction lines, corresponding to multiple hkl indices, are (d in Å (relative visual intensity)): 5.04 (65), 4.09 (60), 2.961 (100), 2.885 (40), and 2.047 (60). The crystal structure study revealed carmeltazite to be orthorhombic, space group Pnma, with unit-cell parameters a = 14.0951 (9), b = 5.8123 (4), c = 10.0848 (7) Å, V = 826.2 (1) Å3, and Z = 4. The crystal structure was refined to a final R1 = 0.0216 for 1165 observed reflections with Fo > 4?(Fo). Carmeltazite exhibits a structural arrangement similar to that observed in a defective spinel structure. The name carmeltazite derives from Mt Carmel (“CARMEL”) and from the dominant metals present in the mineral, i.e., Titanium, Aluminum and Zirconium (“TAZ”). The mineral and its name have been approved by the IMA Commission on New Minerals, Nomenclature and Classification (2018-103).
DS201903-0514
2019
Saunders, M.Griffin, W.L., Gain, S.E.M., Huang, J-X., Saunders, M., Shaw, J., Toledo, V., O'Reilly, S.Y.A terrestrial magmatic hibonite-grossite-vanadium assemblage: desilication and extreme reduction in a volcanic plumbing system, Mount Carmel, Israel.American Mineralogist, Vol. 104, pp. 207-219.Europe, Israelmelting

Abstract: Hibonite (CaAl12O19) is a constituent of some refractory calcium-aluminum inclusions (CAIs) in carbonaceous meteorites, commonly accompanied by grossite (CaAl4O7) and spinel. These phases are usually interpreted as having condensed, or crystallized from silicate melts, early in the evolution of the solar nebula. Both Ca-Al oxides are commonly found on Earth, but as products of high-temperature metamorphism of pelitic carbonate rocks. We report here a unique occurrence of magmatic hibonitegrossite-spinel assemblages, crystallized from Ca-Al-rich silicate melts under conditions [high-temperature, very low oxygen fugacity (fO2)] comparable to those of their meteoritic counterparts. Ejecta from Cretaceous pyroclastic deposits on Mt Carmel, N. Israel, include aggregates of hopper/skeletal Ti-rich corundum, which have trapped melts that crystallized at fO2 extending from 7 log units below the iron-wustite buffer (?IW = -7; SiC, Ti2O3, Fe-Ti silicide melts) to ?IW ? -9 (native V, TiC, and TiN). The assemblage hibonite + grossite + spinel + TiN first crystallized late in the evolution of the melt pockets; this hibonite contains percentage levels of Zr, Ti, and REE that reflect the concentration of incompatible elements in the residual melts as corundum continued to crystallize. A still later stage appears to be represented by coarse-grained (centimeter-size crystals) ejecta that show the crystallization sequence: corundum + Liq ? (low-REE) hibonite ? grossite + spinel ± krotite ? Ca4Al6F2O12 + fluorite. V0 appears as spheroidal droplets, with balls up to millimeter size and spectacular dendritic intergrowths, included in hibonite, grossite, and spinel. Texturally late V0 averages 12 wt% Al and 2 wt% Mn. Spinels contain 10-16 wt% V in V0-free samples, and <0.5 wt% V in samples with abundant V 0. Ongoing paragenetic studies suggest that the fO2 evolution of the Mt Carmel magmatic system reflects the interaction between OIB-type mafic magmas and mantle-derived CH4+H2 fluids near the crust-mantle boundary. Temperatures estimated by comparison with 1 atm phase-equilibrium studies range from ca. 1500 °C down to 1200-1150 °C. When fO2 reached ca. ?IW = -7, the immiscible segregation of Fe,Ti-silicide melts and the crystallization of SiC and TiC effectively desilicated the magma, leading to supersaturation in Al2O3 and the rapid crystallization of corundum, preceding the development of the hibonite-bearing assemblages. Reports of Ti-rich corundum and SiC from other areas of explosive volcanism suggest that these phenomena may be more widespread than presently realized, and the hibonite-grossite assemblage may serve as another indicator to track such activity. This is the first reported terrestrial occurrence of krotite (CaAl2O4), and of at least two unknown Zr-Ti oxides.
DS201910-2258
2019
Saunders, M.Gain, S.E., Griffin, W.L., Saunders, M., Shaw, J.A., Toledo, V.A showcase of analytical techniques: native vanadium in hibonite and chromium in corundum: ultra-high contents under reducing conditions. Two posters Shefa Gems Microscopy and Microanalysis ( M&M)Co. Conference, Sept. 9, posters 1 p. eachEurope, Israeldeposit - Kishon

Abstract: The Microscopy and Microanalysis (M&M) conference in Portland Oregon, USA is one of the biggest microscopy conferences in the world and this year it hosted its largest meeting in history with over 3,300 participants, up to 20 parallel sessions and over 600 posters. The two posters were presented by Sarah E.M. Gain who is from the University of Western Australia where she trains and supports researchers in Microscopy, Characterisation and Microanalysis. Sarah discussed some of the unique gem material collected from Shefa Gems’ exploration activity in the Kishon Mid Reach and Rakefet Magmatic Complex, analysed using a range of microscopy and microanalysis techniques. She also discussed the scientific importance of this material.The first poster looked at hibonite (a Ca-Al-oxide) with inclusions of vanadium metal. The second poster looked at, Cr corundum (ruby), which is unusual due to the extremely high Cr levels and the inclusions of Cr metal.
DS202012-2217
2020
Saunders, M.Griffin, W.L., Gain, S.E.M., Saunders, M., Bindi, L., Alard, O., Toledo, V., O'Reilly, S.Y.Parageneses of TiB2 in corundum xenoliths from Mt. Carmel, Israel: siderophile behavior of boron under reducing conditions.American Mineralogist, Vol. 105, pp. 1609-1621. pdfEurope, Israeldeposit - Mt. Carmel

Abstract: Titanium diboride (TiB2) is a minor but common phase in melt pockets trapped in the corundum aggregates that occur as xenoliths in Cretaceous basaltic volcanoes on Mt. Carmel, north Israel. These melt pockets show extensive textural evidence of immiscibility between metallic (Fe-Ti-C-Si) melts, Ca-Al-Mg-Si-O melts, and Ti-(oxy)nitride melts. The metallic melts commonly form spherules in the coexisting oxide glass. Most of the observed TiB2 crystallized from the Fe-Ti-C silicide melts and a smaller proportion from the oxide melts. The parageneses in the melt pockets of the xenoliths require fO2 ? ?IW-6, probably generated through interaction between evolved silicate melts and mantle-derived CH4+H2 fluids near the crust-mantle boundary. Under these highly reducing conditions boron, like carbon and nitrogen, behaved mainly as a siderophile element during the separation of immiscible metallic and oxide melts. These parageneses have implications for the residence of boron in the peridotitic mantle and for the occurrence of TiB2 in other less well-constrained environments such as ophiolitic chromitites.
DS202101-0001
2020
Saunders, M.Bindi, L., Camara, F., Gain, S.E.M., Griffin, W.L., Huang, J-X., Saunders, M., Toledo, V.Kishonite, VH2 and oreillyite, Cr2N, two new minerals from the conundrum xenocrysts of Mt. Carmel, northern Israel.Minerals MDPI, Vol. 10, 1118, doi:10.3390/ min10121118 10p. PdfEurope, Israeldeposit - Mt. Carmel

Abstract: Here, we describe two new minerals, kishonite (VH2) and oreillyite (Cr2N), found in xenoliths occurring in pyroclastic ejecta of small Cretaceous basaltic volcanoes exposed on Mount Carmel, Northern Israel. Kishonite was studied by single-crystal X-ray diffraction and was found to be cubic, space group Fm3¯m, with a = 4.2680(10) Å, V = 77.75(3) Å3, and Z = 4. Oreillyite was studied by both single-crystal X-ray diffraction and transmission electron microscopy and was found to be trigonal, space group P3¯1m, with a = 4.7853(5) Å, c = 4.4630(6) Å, V = 88.51 Å3, and Z = 3. The presence of such a mineralization in these xenoliths supports the idea of the presence of reduced fluids in the sublithospheric mantle influencing the transport of volatile species (e.g., C, H) from the deep Earth to the surface. The minerals and their names have been approved by the Commission of New Minerals, Nomenclature and Classification of the International Mineralogical Association (No. 2020-023 and 2020-030a).
DS202101-0013
2020
Saunders, M.Griffin, W.L., Gain, S.E.M., Saunders, M., Bindi, L., Alard, O., Toledo, V., O'Reilly, S.Y.Parageneses of TIB2 in corundum xenoliths from Mt. Carmel, Israel: siderophile behaviour of boron under reducing conditions.American Mineralogist , in press available 33p. PdfEurope, Israeldeposit - Mt. Carmel

Abstract: Titanium diboride (TiB2) is a minor but common phase in melt pockets trapped in the corundum aggregates that occur as xenoliths in Cretaceous basaltic volcanoes on Mt. Carmel, north Israel. These melt pockets show extensive textural evidence of immiscibility between metallic (Fe-Ti-C-Si) melts, Ca-Al-Mg-Si-O melts, and Ti-(oxy)nitride melts. The metallic melts commonly form spherules in the coexisting oxide glass. Most of the observed TiB2 crystallized from the Fe-Ti-C silicide melts and a smaller proportion from the oxide melts. The parageneses in the melt pockets of the xenoliths require fO2 ? ?IW-6, probably generated through interaction between evolved silicate melts and mantle-derived CH4+H2 fluids near the crust-mantle boundary. Under these highly reducing conditions boron, like carbon and nitrogen, behaved mainly as a siderophile element during the separation of immiscible metallic and oxide melts. These parageneses have implications for the residence of boron in the peridotitic mantle and for the occurrence of TiB2 in other less well-constrained environments such as ophiolitic chromitites.
DS202108-1286
2021
Saunders, M.Griffin, W.L., Gain, S.E.M., Saunders, M., Alard, O., Shaw, J., Toledo, V.Nitrogen under super-reducing conditions: Ti Oxynitride melts in xenolithic corundum aggregates from Mt. Carmel.Minerals, Vol. 11, 780, 16p. PdfEurope, Israeldeposit - Mt. Carmel

Abstract: Titanium oxynitrides (Ti(N,O,C)) are abundant in xenolithic corundum aggregates in pyroclastic ejecta of Cretaceous volcanoes on Mount Carmel, northern Israel. Petrographic observations indicate that most of these nitrides existed as melts, immiscible with coexisting silicate and Fe-Ti-C silicide melts; some nitrides may also have crystallized directly from the silicide melts. The TiN phase shows a wide range of solid solution, taking up 0-10 wt% carbon and 1.7-17 wt% oxygen; these have crystallized in the halite (fcc) structure common to synthetic and natural TiN. Nitrides coexisting with silicide melts have higher C/O than those coexisting with silicate melts. Analyses with no carbon fall along the TiN-TiO join in the Ti-N-O phase space, implying that their Ti is a mixture of Ti3+ and Ti2+, while those with 1-3 at.% C appear to be solid solutions between TiN and Ti0.75O. Analyses with >10 at% C have higher Ti2+/Ti3+, reflecting a decrease in fO2. Oxygen fugacity was 6 to 8 log units below the iron-wüstite buffer, at or below the Ti2O3-TiO buffer. These relationships and coexisting silicide phases indicate temperatures of 1400-1100 °C. Ti oxynitrides are probably locally abundant in the upper mantle, especially in the presence of CH4-H2 fluids derived from the deeper metal-saturated mantle.
DS202110-1616
2021
Saunders, M.Griffin, W.L., Gain, S.E.M., Saunders, M., Camara, F., Bindi, L., Sparta, D., Toledo, V., O'Reilly, S.Y.Cr203 in corundum: ultrahigh contents under reducing conditions. American Mineralogist, Vol. 106, pp. 1420-1437. pdfEurope, Israeldeposit - Mount Carmel

Abstract: Xenocrysts and xenoliths in Upper Cretaceous pyroclastics on Mount Carmel (northern Israel) represent a series of similar magma-fluid systems at different stages of their evolution, recording a continuous decrease in oxygen fugacity (fO2) as crystallization proceeded. Corundum coexisting with Fe-Mg-Cr-Al spinels, other Fe-Mg-Al-Na oxides, and Fe-Ni alloys in apparent cumulates crystallized at fO2 values near the iron-wüstite (IW) buffer (fO2 = IW±1) and is zoned from high-Cr cores to lower-Cr rims, consistent with fractional crystallization trends. The reconstructed parental melts of the cumulates are Al-Cr-Fe-Mg oxides with ca. 2 wt% SiO2. Corundum in other possible cumulates that contain Cr-Fe (Fe 45 wt%) alloys has low-Cr cores and still lower-Cr rims. Corundum coexisting with Cr0 (fO2 = IW-5) in some possible cumulates has low-Cr cores, but high-Cr rims (to >30% Cr2O3). These changes in zoning patterns reflect the strong decrease in the melting point of Cr2O3, relative to Al2O3, with decreasing fO2. The electron energy loss spectroscopy (EELS) analyses show that all Cr in corundum that coexists with Cr0 is present as Cr3+. This suggests that late in the evolution of these reduced melts, Cr2+ has disproportionated via the reaction 3Cr2+(melt) ? 2Cr3+(Crn) + Cr0. The most Cr-rich corundum crystallized together with ?-alumina phases including NaAl11O17 (diaoyudaoite) and KAl11O17 (kahlenbergite) and ??-alumina phases; residual melts crystallized a range of (K,Mg)2(Al,Cr)10O17 phases with the kahlenbergite structure. The parental melts of these assemblages appear to have been Al-Cr-K-Na-Mg oxides, which may be related to the Al-Cr-Fe-Mg oxide melts mentioned above, through fractional crystallization or liquid immiscibility. These samples are less reduced (fO2 from IW to IW-5) than the assemblages of the trapped silicate melts in the more abundant xenoliths of corundum aggregates (fO2 = IW-6 to IW-10). They could be considered to represent an earlier stage in the fO2 evolution of an “ideal” Mt. Carmel magmatic system, in which mafic or syenitic magmas were fluxed by mantle-derived CH4+H2 fluids. This is a newly recognized step in the evolution of the Mt. Carmel assemblages and helps to understand element partitioning under highly reducing conditions.
DS1975-0153
1975
Saunders, M.J.O'hara, M.J., Saunders, M.J., Mercy, E.L.P.Garnet Peridotite, Primary Ultrabasic Magmas and Eclogites:interpretation of Upper Mantle Processes in Kimberlite.Physics and Chemistry of the Earth., Vol. 9, PP. 571-604.South AfricaPetrology
DS202204-0520
2022
Saunders, M.J.Griffin, W.L., Gain, S.E.M., Saunders, M.J., Huang, J-X., Alard, O., Toledo, V., O'Reilly, S.Y.Immiscible metallic melts in the upper mantle beneath Mount Carmel, Israel: silicides, phosphides, and carbides.American Mineralogist, Vol. 107, pp. 532-549.Europe, Israeldeposit - Mount Carmel

Abstract: Xenolithic corundum aggregates in Cretaceous mafic pyroclastics from Mount Carmel contain pockets of silicate melts with mineral assemblages [SiC (moissanite), TiC, Ti2O3 (tistarite), Fe-Ti-Zr silicides/phosphides] indicative of magmatic temperatures and oxygen fugacity (fO2) at least 6 log units below the iron-wüstite buffer (?IW ? -6). Microstructural evidence indicates that immiscible, carbon-rich metallic (Fe-Ti-Zr-Si-P) melts separated during the crystallization of the silicate melts. The further evolution of these metallic melts was driven by the crystallization of two main ternary phases (FeTiSi and FeTiSi2) and several near-binary phases, as well as the separation of more evolved immiscible melts. Reconstructed melt compositions fall close to cotectic curves in the Fe-Ti-Si system, consistent with trapping as metallic liquids. Temperatures estimated from comparisons with experimental work range from ?1500 °C to ca. 1150 °C; these probably are maximum values due to the solution of C, H, P, and Zr. With decreasing temperature (T), the Si, Fe, and P contents of the Fe-Ti-Si melts increased, while contents of Ti and C decreased. The increase in Si with declining T implies a corresponding decrease in fO2, probably to ca. ?IW-9. The solubility of P in the metallic melts declined with T and fO2, leading to immiscibility between Fe-Ti-Si melts and (Ti,Zr)-(P,Si) melts. Decreasing T and fO2 also reduced the solubility of C in the liquid metal, driving the continuous crystallization of TiC and SiC during cooling. The lower-T metallic melts are richer in Cr, and to some extent V, as predicted by experimental studies showing that Cr and V become more siderophile with decreasing fO2. These observations emphasize the importance of melt-melt immiscibility for the evolution of magmas under reducing conditions. The low fO2 and the abundance of carbon in the Mt. Carmel system are consistent with a model in which differentiating melts were fluxed by fluids that were dominated by CH4+H2, probably derived from a metal-saturated sublithospheric mantle. A compilation of other occur-rences suggests that these phenomena may commonly accompany several types of explosive volcanism.
DS1990-0788
1990
Saupe, D.Jurgens, H., Pietgen, H-O., Saupe, D.The language of fractalsScientific American, Vol. 263, No. 2, August pp. 60-67GlobalFractals, Layman's overview
DS2000-0857
2000
Saurabh, K.V.Saurabh, K.V.Geological and geophysical fabric of Indian Cratons in context of diamond exploration.Igc 30th. Brasil, Aug. abstract only 1p.IndiaCraton - 80 kimberlites/lamproites, Overview
DS1991-1502
1991
Sauterm E.A.Sauterm E.A.An automatic quasi-absolute geomagnetic calibration systemUnited States Geological Survey (USGS) Open File, No. 91-0350, 11p. $ 9.25GlobalComputer, Program -geomagnetic
DS1991-1503
1991
Sauterm E.A.Sauterm E.A.Magnetometer calibration deviceUnited States Geological Survey (USGS) Open File, No. 91-0351, 9p. $ 5.25GlobalComputer, Program -magnetic
DS2002-0906
2002
SautterKunz, M., Gillet, Fiquet, Sautter, Graafsma, ConradCombined in situ x-ray diffraction and raman spectroscopy on majoritic garnet inclusions in diamondsEarth and Planetary Science Letters, Vol.198,3-4,pp.485-93., Vol.198,3-4,pp.485-93.GlobalSpectroscopy, Diamond inclusions
DS2002-0907
2002
SautterKunz, M., Gillet, Fiquet, Sautter, Graafsma, ConradCombined in situ x-ray diffraction and raman spectroscopy on majoritic garnet inclusions in diamondsEarth and Planetary Science Letters, Vol.198,3-4,pp.485-93., Vol.198,3-4,pp.485-93.GlobalSpectroscopy, Diamond inclusions
DS1986-0704
1986
Sautter, V.Sautter, V., Harte, B.Chemical equilibrium and diffusion gradients in eclogite xenolith JJG 41:an isothermal model for exsolution reactionProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 315-317South AfricaBlank
DS1988-0611
1988
Sautter, V.Sautter, V., Harte, B.Diffusion gradients in an eclogite xenolith from theRoberts Victorkimberlite pipe: 1. Mechanism- Evolution of garnet exsolution in Al2O3 richclinopyroxeneJournal of Petrology, Vol. 29, No. 6, December pp. 1325-1352South AfricaXenoliths, Analyses
DS1990-0632
1990
Sautter, V.Haggerty, S.E., Sautter, V.Ultradeep (greater than 300 kilometers) ultramafic upper mantle xenolithsScience, Vol. 248, No. 4958, May 25, pp. 993-996GlobalMantle, Xenoliths
DS1990-0633
1990
Sautter, V.Haggerty, S.E., Sautter, V.Ultra deep ( >300km) garnet clinopyroxene xenoliths in diamondiferouskimberlitesEos, Vol. 71, No. 17, April 24, p. 523 Abstract onlySouth AfricaJagersfontein, Garnet analyses
DS1990-1303
1990
Sautter, V.Sautter, V.Cooling kinetics of upper mantle eclogites in cratonic and alpinesettingEos, Vol. 71, No. 17, April 24, p. 523 Abstract onlySouth Africa, PyreneesEclogites, Xenoliths
DS1990-1304
1990
Sautter, V.Sautter, V., Harte, B.Diffusion gradients in an eclogite xenolith from the Roberts Victorkimberlite pipe: (2) kinetics and implications for petrogenesisContributions to Mineralogy and Petrology, Vol. 105, pp. 637-649South AfricaEclogite, Roberts Victor
DS1991-1504
1991
Sautter, V.Sautter, V., Haggerty, S.E.Ultra-deep (> 300km),ultramafic xenoliths: direct petrological evidence for the transition zoneProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 347-349South AfricaXenoliths, Jagersfontein, petrology
DS1991-1505
1991
Sautter, V.Sautter, V., Haggerty, S.E., Field, S.Ultradeep (> 300 kilometers) ultramafic xenoliths: petrological evidence from the transition zoneScience, Vol. 252, No. 5007, May 10, pp. 827-830South Africa, BrazilXenoliths, Majorite/spinel, seismic gradient, geophysics
DS1994-0444
1994
Sautter, V.Doukhan, N., Sautter, V., Doukhan, J.C.Ultradeep, ultramafic mantle xenoliths: transmission electron microscopy preliminary results.Physics of the Earth and Planetary Interiors, Vol. 82, No. 3-4, pp. 195-207.South AfricaXenoliths, Deposit -Jagersfontein
DS1994-1530
1994
Sautter, V.Sautter, V., Gillet, P.Les diamants, messagers de profondeurs de la terre.(in French)La Recherche, (in French), Vol. 25, Dec. 21, pp. 1238-45.GlobalDiamond genesis -overview
DS1998-1285
1998
Sautter, V.Sautter, V., Harte, B., Harris, J.W.Majorite destabilisation on decompression: constrains from natural sample son plume velocity.Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1320-1.BrazilMajorites, Deposit - Sao Luiz
DS1999-0333
1999
Sautter, V.Jaoul, O., Sautter, V.A new approach to geospeedometry based on the 'compensation law'Physical Earth and Planetary Interiors, Vol. 110, pp. 95-114.MantleCooling rate, Lasaga's model
DS2001-1018
2001
Sautter, V.Sautter, V., Duchene, S., Marques, F.O.New analytical and numerical geospeedometers tested on garnet pyroxenites from Braganca Nappe Complex.Tectonophysics, Vol. 342, No. 1-2, Dec. pp. 39-59.Portugal, northeastGeospeedometry
DS2002-0105
2002
Sautter, V.Barrat, J.A., Jambon, A., Bohn, M., Gillet, P., Sautter, V., Gopei, C., Lesourd, M.Petrology and chemistry of the picritic shergottite north west AfricaGeochimica et Cosmochimica Acta, Vol.66, 19, pp.3505-18.West AfricaPicrites
DS2002-0572
2002
Sautter, V.Gillet, P., Sautter, V., Harris, Reynard, Harte, KunzRaman spectroscopic study of garnet inclusions in diamonds from the mantle transition zone.American Mineralogist, Vol.87, 2-3, pp. 312-17.BrazilSpectroscopy - majoritic content, Deposit - Sao Luiz
DS2002-0660
2002
Sautter, V.Harte, B., Harris, J.W., Wilding, M., Sautter, V., McCammon, C.Eclogite garnetite inclusions in diamonds from the Sao Luiz area, Brasil18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.74.BrazilGarnet mineralogy
DS200512-0380
2005
Sautter, V.Guilhaumou, N., Sautter, V., Dumas, P.Synchrotron FTIR microanalysis of volatiles in melt inclusions and exsolved particles in ultramafic deep seated garnets.Chemical Geology, In press.Africa, South AfricaJagersfontein, ultradeep xenoliths, partial melting
DS200812-0970
2008
Sautter, V.Rondeau, B., Sautter, V., Barjon, J.New columnar texture of carbonado: cathodluminescence study.Diamond and Related Materials, Vol. 17, 11, November pp. 1897-1901.TechnologyCarbonado
DS201012-0665
2010
Sautter, V.Sautter, V.Black diamonds: a crustal origin for carbonado.International Mineralogical Association meeting August Budapest, AbstractTechnologyCarbonado
DS201508-0375
2015
Sautter, V.Sautter, V.Martian crustal rocks bear a strong resemblance to tonalite-trondjemite-granodiorites… Earth's continental crust ( 2.5 billion years ago).Physics.org, July 14, 1/4p.MantleCrust - history
DS202107-1090
2021
Sauumur, B. M.Bedard, J.H., Troll, V.R., Deegan F.M., Tegner, C., Sauumur, B. M., Evenchick, C.A., Grasby, S.E., Dewing, K.High Arctic large igneous province alkaline rocks in Canada: evidence for multiple mantle components.Journal of Petrology, 113p. In press availableCanada, Ellesmerealkaline rocks

Abstract: The Cretaceous High Arctic Large Igneous Province (HALIP) in Canada, although dominated by tholeiites (135-90?Ma), contains two main groups of alkaline igneous rocks. The older alkaline rocks (?96?Ma) scatter around major fault and basement structures. They are represented by the newly-defined Fulmar Suite alkaline basalt dykes and sills, and include Hassel Formation volcanics. The younger alkaline group is represented by the Wootton Intrusive Complex (92.2-92.7?Ma), and the Audhild Bay Suite (83-73?Ma); both emplaced near the northern coast of Ellesmere Island. Fulmar Suite rocks resemble EM-type ocean island basalts (OIB) and most show limited crustal contamination. The Fulmar Suite shows increases of P2O5 at near-constant Ba-K-Zr-Ti that are nearly orthogonal to predicted fractionation- or melting-related variations; which we interpret as the result of melting composite mantle sources containing a regionally widespread apatite-bearing enriched component (P1). Low-P2O5 Fulmar Suite variants overlap compositionally with enriched HALIP tholeiites, and fall on common garnet lherzolite trace element melting trajectories, suggesting variable degrees of melting of a geochemically similar source. High-P2O5 Hassel Formation basalts are unusual among Fulmar rocks, because they are strongly contaminated with depleted lower crust; and because they involve a high-P2O5-Ba-Eu mantle component (P2), similar to that seen in alkali basalt dykes from Greenland. The P2 component may have contained Ba-Eu-rich hawthorneite and/or carbonate minerals as well as apatite, and may typify parts of the Greenlandic sub-continental lithospheric mantle (SCLM). Mafic alkaline Audhild Bay Suite (ABS) rocks are volcanic and hypabyssal basanites, alkaline basalts and trachy-andesites, and resemble HIMU ocean island basalts in having high Nb, low Zr/Nb and low 87Sr/86Sri. These mafic alkaline rocks are associated with felsic alkaline lavas and syenitic intrusions, but crustally-derived rhyodacites and rhyolites also exist. The Wootton Intrusive Complex (WIC) contains geochemically similar plutonic rocks (alkali gabbros, diorites and anatectic granites), and may represent a more deeply eroded, slightly older equivalent of the ABS. Low-P2O5 ABS and WIC alkaline mafic rocks have flat heavy rare-earth (HREE) profiles suggesting shallow mantle melting; whereas High-P2O5 variants have steep HREE profiles indicating deeper separation from garnet-bearing residues. Some High-P2O5 mafic ABS rocks seem to contain the P1 and P2 components identified in Fulmar-Hassel rocks, whereas other samples trend towards possible High-P2O5+Zr (PZr) and High-P2O5+K2O (PK) components. We argue that the strongly alkaline northern Ellesmere Island magmas sampled mineralogically heterogeneous veins or metasomes in Greenlandic-type SCLM, which contained trace phases like apatite, carbonates, hawthorneite, zircon, mica or richterite. The geographically more widespread apatite-bearing component (P1), could have formed part of a heterogeneous plume or upwelling mantle current that also generated HALIP tholeiites when melted more extensively, but may also have resided in the SCLM as relics of older events. Rare HALIP alkaline rocks with high K-Rb-U-Th fall on mixing paths implying strong local contamination from either Sverdrup Basin sedimentary rocks or granitic upper crust. However, the scarcity of potassic alkaline HALIP facies, together with the other trace element and isotopic signatures, provide little support for an ubiquitous fossil sedimentary subduction zone component in the HALIP mantle source.
DS1985-0085
1985
Sauvage, J.F.Brigaud, F., Lucazeau, F., Ly, S., Sauvage, J.F.Heat Flow from the West African ShieldGeophysical Research. LETTERS, Vol. 12, No. 9, SEPTEMBER PP. 549-552.West AfricaBlank
DS1991-0989
1991
Sauvage, J.F.Ligeois, J.P., Sauvage, J.F., Black, R.The Permo-Jurassic alkaline province of Tadhak, Mali: geology, geochronology and tectonic significanceLithos, Vol. 27, pp. 95-105GlobalAlkaline rocks, Craton
DS1999-0111
1999
Sauvage, J.F.Capdevila, R., Arndt, N., Sauvage, J.F.Diamonds in volcaniclastic komatiite from French GuianaNature., Vol. 399, No. 6735, June 3, pp. 456-8.French GuianaKomatiite
DS201312-0780
2013
Sauzeat, L.Sauzeat, L., Cordier, C., Arndt, N.T.How kimberlites form: clues from olivine geochemistry.Goldschmidt 2013, 1p. AbstractTechnologyKimberlite genesis
DS201512-1905
2015
Sauzeat, L.Cordier, C., Sauzeat, L., Arndt, N.T., Boullier, A-M., Batanova, V., Barou, F.Metasomatism of the lithospheric mantle immediately precedes kimberlite eruption: new evidence from olivine composition and microstructures.Journal of Petrology, Vol. 56, 9, pp. 1775-1796.TechnologyOlivine, metasomatism

Abstract: Most kimberlites contain abundant dunitic nodules. These are centimetre-sized, rounded and multi-grained assemblages of xenocrystic olivine with a wide range of compositions (Fo83 to Fo94). The absence of orthopyroxene and other mantle minerals and the range of olivine compositions have been attributed to reaction between mantle peridotite and (proto)kimberlitic fluid or melt, but the timing of the reaction is a subject of debate. In a kimberlite from the Kangamiut region of Greenland, nodule cores are surrounded by fine-grained outer margins with near-constant Fo contents (~Fo88) but highly variable minor element contents (e.g. 500-2500 ppm Ni). These margins crystallized from the kimberlite melt and we show that their compositions can be explained by crystallization of olivine alone, if a high partition coefficient for Ni between melt and olivine (DNi > 20) is assumed. Orthopyroxene assimilation is not required, removing the constraint that its dissolution occurred during ascent of the kimberlite magma. Within some nodules, in addition to the usual core-to-margin gradients, we observe asymmetric compositional changes (variable Fo but near-constant minor element contents) across mobile grain boundaries. These changes document fluid percolation at the grain scale that occurred during dynamic recrystallization in the deforming lithospheric mantle. We note that chemical gradients associated with mobile grain boundaries are observed in olivines that cover the entire compositional range of the nodules, and propose that fluid-assisted dynamic recrystallization took place in dunite that was already compositionally heterogeneous. Reaction between peridotite and protokimberlitic melt or fluid and dissolution of orthopyroxene thus occurred within the lithospheric mantle, immediately (a few days) prior to the ascent of the kimberlite melt and the entrainment of the dunite nodules. We propose that the grain boundary zones probably mimic, at a fine scale, the fluid-peridotite interaction that caused, at a larger scale, orthopyroxene dissolution and formation of compositionally diverse olivine in kimberlites.
DS201601-0011
2015
Sauzeat, L.Cordier, C., Sauzeat, L., Arndt, N.T., Boullier, A-M., Batanova, V., Barou, F.Metasomatism of the lithospheric mantle immediately precedes kimberlite eruption: new evidence from olivine composition and mircostructures.Journal of Petrology, Vol. 56, 9, pp. 1775-1796.Europe, GreenlandDeposit - Kangamiut field

Abstract: Most kimberlites contain abundant dunitic nodules. These are centimetre-sized, rounded and multi-grained assemblages of xenocrystic olivine with a wide range of compositions (Fo83 to Fo94). The absence of orthopyroxene and other mantle minerals and the range of olivine compositions have been attributed to reaction between mantle peridotite and (proto)kimberlitic fluid or melt, but the timing of the reaction is a subject of debate. In a kimberlite from the Kangamiut region of Greenland, nodule cores are surrounded by fine-grained outer margins with near-constant Fo contents (~Fo88) but highly variable minor element contents (e.g. 500-2500 ppm Ni). These margins crystallized from the kimberlite melt and we show that their compositions can be explained by crystallization of olivine alone, if a high partition coefficient for Ni between melt and olivine (DNi > 20) is assumed. Orthopyroxene assimilation is not required, removing the constraint that its dissolution occurred during ascent of the kimberlite magma. Within some nodules, in addition to the usual core-to-margin gradients, we observe asymmetric compositional changes (variable Fo but near-constant minor element contents) across mobile grain boundaries. These changes document fluid percolation at the grain scale that occurred during dynamic recrystallization in the deforming lithospheric mantle. We note that chemical gradients associated with mobile grain boundaries are observed in olivines that cover the entire compositional range of the nodules, and propose that fluid-assisted dynamic recrystallization took place in dunite that was already compositionally heterogeneous. Reaction between peridotite and protokimberlitic melt or fluid and dissolution of orthopyroxene thus occurred within the lithospheric mantle, immediately (a few days) prior to the ascent of the kimberlite melt and the entrainment of the dunite nodules. We propose that the grain boundary zones probably mimic, at a fine scale, the fluid-peridotite interaction that caused, at a larger scale, orthopyroxene dissolution and formation of compositionally diverse olivine in kimberlites.
DS201706-1068
2017
Sauzeat, L.Cordier, C., Sauzeat, L., Arndt, N.T., Boullier, A-M., Batanova, V., Barou, F.Quantitative modelling of the apparent decoupling of Mg# and Ni in kimberlitic olivine margins: comment on Cordier et al. by A.Moore.Journal of Petrology, Vol. 58, pp. 1-3.Europe, Greenlanddeposit - Kangamiut

Abstract: Moore proposes in his Comment (Moore, 2017) that marginal zones in olivine grains in kimberlites (Fig. 1a) are produced by crystallization from kimberlite melt. He suggests that the chemical zones observed in these marginal zones (inner transition zones and outer margins, illustrated in his fig. 1) result from abrupt changes in distribution coefficients during crystallization. He proposes that the transition zones, characterized by variable Fo at constant and high Ni contents, are produced by crystallization with high KdFe-Mg (= 0•45) and low DNi (= 4) whereas the margins, characterized by a sharp drop in Ni content at nearly constant Fo (Fig. 1b), are produced by crystallization with higher DNi owing to a sudden change in physical conditions of crystallization (P,…
DS201412-0145
2014
Sauzert, L.Cordier, C., Sauzert, L., Arndt, N., Boullier, A-M.Olivine in kimberlites: metasomatism of the deep lithospheric mantle.Economic Geology Research Institute 2014, No. 11390 1p. abstractMantleMetasomatism
DS1985-0341
1985
Savage, B.Kilinc, A., Savage, B.Geochemistry and Geothermometry of Elliott County, Kimberlite Megacrysts and Ultramafic Xenoliths.Eos, Vol. 66, No. 18, APRIL 30TH. P. 393. (abstract.).United States, Kentucky, AppalachiaMineral Chemistry
DS200612-1301
2006
Savage, B.Silver, P.G., Behn, M., Kelley, K., Schmitz, M., Savage, B.Understanding cratonic flood basalts.Earth and Planetary Science Letters, in pressAfrica, South Africa, RussiaCraton, lithosphere, origin debate
DS200812-1008
2008
Savage, B.Savage, B., Silver, P.G.Evidence for a compositional boundary within the lithospheric mantle beneath the Kalahari Craton from S receiver functions.Earth and Planetary Science Letters, Vol. 272, 3-4, pp. 600-609.Africa, South AfricaBoundary, metasomatism
DS1985-0588
1985
Savage, B.A.Savage, B.A.Petrology of the Ison Creek Kimberlite, KentuckyMsc. Thesis University of Cincinnati, Ohio, 109pKentuckyPetrology, Ison Creek
DS1994-1531
1994
Savage, M.K.Savage, M.K.Anisotropy and rift systemsNature, Vol. 371, Sept. 8, p. 105-106.MantleTectonics
DS2000-0858
2000
Savage, M.K.Savage, M.K., Sheehan, A.F.Seismic anistropy and mantle flow from the Great Basin to the Great western United States.Journal of Geophysical Research, Vol. 105, No. 6, June 10, pp. 13715-34.United States, MontanaGeophysics - seismics
DS2002-1409
2002
Savage, M.K.Savage, M.K.Seismic anisotropy and mantle deformation in the Western United States and southwestern Canada.International Geology Review, Vol. 44, 10, pp. 913-37.British Columbia, AlbertaGeophysics - seismics, Tectonics
DS202105-0788
2021
Savage, N.Savage, N.Quantum Diamond Sensors Synthetic versions of the super-hard gem stone are driving the development of a class of device with applications in biomedicine and beyond.https://youtu.be/VCT0wDLyvSs, https://www.nature.com/articles /d41586-021-00742-4? utm_source=Nature+Briefing&utm_campaign=d5a18a3501- briefing-dy-20210329& utm_medium=email&utm_term= 0_c9dfd39373- d5a18a3501-42627851Globalsynthetic - uses
DS1989-1542
1989
Savage, W.Z.Varnes, D.J., Radbruch-Hall, D.H., Savage, W.Z.Topographic and structural conditions in areas of gravitational spreading of ridges in the western United StatesUnited States Geological Survey (USGS) Prof. Paper, No. 1496, 28pColorado, MontanaStructure, General-specific regions
DS202107-1134
2021
Savard, G.Snyder, D.B., Savard, G., Kjarssgaard, B.A., Vaillancourt, A., Thurston, P.C., Ayer, J.A., Roots, E.Multidisciplinary modeiling of mantle lithosphere structure within the Superior craton, North America.Geochemistry, Geophysics, Geosytems, 20p. PdfCanada, United Statesgeophysics - seismics

Abstract: Structure within the Earth is best studied in three dimensions and using several coincident overlays of diverse information with which one can best see where unusual properties match up. Here we use regional surfaces causing discontinuities in seismic waves a few hundred kilometers deep in the Earth, intersected and thus calibrated by rebuilt rock columns using rare rock samples erupted to the surface in two locations. Electrically conductive regions can be mapped using natural (magnetotelluric) currents. East- and west-dipping seismic discontinuity surfaces match surface structures that developed about 1.8 billion years ago marginal to the Superior crustal block. Surfaces dipping to the southeast and northwest match some boundaries between crustal blocks that are over 2.5 billion years old, but many such crustal boundaries trend more east-west. Conductive rocks appear more commonly above these discontinuity surfaces where gas-rich fluids apparently flowed and that the discontinuities somehow filtered these fluids. The mismatch in orientation and dip between the most ancient deep and exposed structures suggests that plate tectonic processes operating today differed earlier than 2.5 billion years ago.
DS201906-1344
2019
Savard, J.Savard, J., Mitchell, R.Petrology of ijolites from the Prairie Lake carbonatite complex.GAC/MAC annual Meeting, 1p. Abstract p. 171.Canada, Ontariodeposit - Prairie Lake

Abstract: This study investigates the major and trace element composition of minerals of the ijolite series rocks occurring at the Prairie Lake Carbonatite Complex, northern Ontario, together with comparative data with ijolites from the Fen complex, Norway. Trace element data (Sr, Zr, REE) were collected by LA-ICP-MS for clinopyroxene, garnet, and apatite, and in conjunction with the major element data are used to develop a petrogenetic model for Prairie Lake. The ijolites and calcite ijolites (hollaites) of Prairie Lake Carbonatite Complex have been formed by magma mixing, crystal settling, solid-state deformation, and deuteric alteration. The complex represents at least three stages of intrusion by melts of differing composition. The initial stage is predominantly biotite pyroxenite and associated coarse carbonatite veins. The second stage is primarily members of the ijolite series together with solid state deformation creating meta-ijolites, with differentiation forming malignites (potassic nepheline syenites). The third major stage is the intrusion of the CII carbonatites derived from different batches of magmas. These rocks contain xenoliths of ijolite suite rocks and phoscorites. Pyroxene compositions show an evolutionary trend from diopside in biotite pyroxenites to Fe enriched diopside-augite in ijolites, to aegirine in malignites. These data are used to show that a continuously filled fractionating magma chamber was not present at Prairie lake and that the complex formed as result of small intrusions of nephelinite into pre-existing ijolites. A similar style of petrogenesis is suggested for the Fen complex.
DS202106-0969
2021
Savard, J.J.Savard, J.J., Mitchell, R.H.Petrology of ijolite series rocks from the Prairie Lake ( Canada) and Fen ( Norway) alkaline rock-carbonatite complexes.Lithos, Vol. 396-397, 106188 20p.Canada, Ontariodeposit - Prairie Lake

Abstract: This study reports the mineralogy and petrology, together with the major and trace element composition of pyroxenes, garnets and apatite from ijolite series rocks occurring at the Prairie Lake carbonatite complex, northwestern Ontario, with comparative data for ijolites from the Fen complex, Norway. The ijolites and calcite ijolites (hollaites) of Prairie Lake record the effects of magma mixing, crystal settling, solid-state re-equilibration and deuteric alteration. The Prairie Lake complex was formed by at least three stages of intrusion. The initial stage was predominantly biotite pyroxenite and associated coarse carbonatite veins. The second stage is represented primarily by members of the ijolite series together with meta-ijolites created by solid state re-equilibration of previously crystallized rocks. Differentiation of the magmas which formed the ijolite suite resulted in the formation of calcite ijolites (hollaites) and malignites (potassic nepheline syenites). The final stage was the intrusion of the heterogeneous carbonatites derived from different batches of carbonatite related magmas. These rocks contain xenoliths of ijolite suite rocks, pyroxene apatitite, wollastonite apatitite, and phoscorite. Pyroxene compositions show an evolutionary trend from diopside in biotite pyroxenites through Fe-enriched diopside-augite in ijolites to aegirine in malignites. Clinopyroxene major and trace element data show that the cores of clinopyroxene in biotite pyroxenites formed as antecrysts at depth and were emplaced as part of a later event. Trace element data from pyroxenes, garnets and apatite from Prairie Lake and Fen are similar to each other and those found in carbonatite complexes worldwide. It is proposed that a continuously-filled fractionating magma chamber was not present at Prairie Lake and that the ijolite-malignite members of the complex formed as result of small intrusions of nephelinitic magma into pre-existing ijolites. Similar styles of magmatic evolution by fractional crystallization are indicated for the Prairie Lake, Fen, and Belaya Zima ijolite?carbonatite complexes and there is no evidence that liquid immiscibility played any role in their petrogenesis.
DS1960-0917
1968
Savarsov, D.I.Balakshin, G.D., Savarsov, D.I.Analyse des Premises de la Nature des Anomalies Magnetiquesau-dessus des Kimberlites, des Carbonatites et des Tufs Trappeens dans la Region de l'anabar.Zap. Vses. Arktiki Institute Geol., No. 12, PP. 171-180. French Geological Survey (BRGM) TRANSLATION No. 5365.RussiaBlank
DS1987-0382
1987
Savary, B.P.Krs, M., Pondaga, M.M., Savary, B.P.Geophysical investigation of the ring structure at Zanzui, NorthernTanzaniaPhysics of the Earth and Planetary Interiors, Vol.45, pp. 294-303TanzaniaGeophysics, Structure
DS1997-1277
1997
Savascin, Y.Yagmurlu, F., Savascin, Y., Ergun, M.Relation of alkaline volcanism and active tectonism within the evolution Of the I sparta Angle, southwest TurkeyJournal of Geology, Vol. 105, No. 6, Nov. pp. 717-728Turkeyvolcanism., Tectonics
DS1984-0425
1984
Savasov, D.I.Kostrovitskiy, S.I., Molchanov, Y.D., Savasov, D.I.Linear Zoning and Structural Controls in Kimberlite Deposits.(russian)Doklady Academy of Sciences Akademy Nauk SSSR (Russian), Vol. 277, No. 5, pp. 1200-1203RussiaPetrology, Kimberlite
DS201312-0225
2013
Savatenkov, V.Doroshkevich, A., Ripp, G., Vladykin, N., Savatenkov, V.Sources of the Late Riphean carbonatite magmatism of northern Transbaikalia.Geochemistry International, Vol. 49, 12, pp. 1195-1207.RussiaCarbonatite
DS200412-1737
2004
Savatenkov, V.M.Savatenkov, V.M., Sergeev, A.V.Nonline at Sr Nd trend of Kola alkaline province carbonatites (KAPC) as implication of the plume related mantle metasomatism.Geochimica et Cosmochimica Acta, 13th Goldschmidt Conference held Copenhagen Denmark, Vol. 68, 11 Supp. July, ABSTRACT p.A570.RussiaCarbonatite
DS200612-0740
2006
Savatenkov, V.M.Kovalenko, V.I., Yarmolyuk, Salnikova, Kozlovski, Kotov, Kovach, Vladykin, Savatenkov, V.M., Ponomarchuk, V.A.Geology and age of Khan-Bogdinsky massif of alkaline granitoids in southern Mongolia.Vladykin: VI International Workshop, held Mirny, Deep seated magmatism, its sources and plumes, pp. 17-45.Asia, MongoliaAlkaline rocks, granites
DS200812-0681
2008
Savatenkov, V.M.Lobach Zhuchenko, S.B., Rollinson, H., Chekulaev, V.P., Savatenkov, V.M., Kovalenko, A.V., Martin, H., Guseva, N.S., Arestova, N.A.Petrology of Late Archean, highly potassic, sanuktoid pluton from the Baltic Shield: insights into Late Archean mantle metasomatism.Journal of Petrology, Vol. 49, 3, pp. 393-420.Europe, Baltic shieldMetasomatism
DS201112-0276
2011
Savatenkov, V.M.Doboshkevich, A.G., Ripp, G.S., Savatenkov, V.M.Alkaline magmatism of Vitim Province West Transbaikalia, Russia: age, mineralogical, geochemical and isotope (O, C,D,Sr,Nd) data.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.35-38.RussiaIjolite
DS201112-0277
2011
Savatenkov, V.M.Doboshkevich, A.G., Ripp, G.S., Savatenkov, V.M.Alkaline magmatism of Vitim Province West Transbaikalia, Russia: age, mineralogical, geochemical and isotope (O, C,D,Sr,Nd) data.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.35-38.RussiaIjolite
DS201112-0284
2011
Savatenkov, V.M.Doroshkevich, A.G., Ripp, G.S., Savatenkov, V.M.Alkaline magmatism of Vitim province, West Transbaikalia, Russia: age, mineralogical, geochemical and isotope (O, C,D, Sr, Nd) data.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterRussiaMagmatism
DS201212-0169
2012
Savatenkov, V.M.Doroshkevich, A.G., Ripp, G.S., Izbrodin, I.A., Savatenkov, V.M.Alkaline magmatism of the Vitim province, west Transbaikalia, Russia: age, mineralogical, geochemical and isotope (O,C,D,Sr and Nd) data.Lithos, Vol. 152, pp. 157-172.RussiaMagmatism
DS201801-0025
2018
Savatenkov, V.M.Ivanov, A.V., Demonterova, E.I., Savatenkov, V.M., Perepelov, A.B., Ryabov, V.V., Shevko, A.Y.Late Triassic (Carnian) lamproites from Norilsk, polar Siberia: evidence for melting of the recycled Archean crust and the question of lamproite source for some placer diamond deposits of the Siberian craton.Lithos, Vol. 296-299, pp. 67-78.Russia, Siberialamproites

Abstract: Two typical lamproitic dykes were found in Noril'sk region of the north-western Siberian Craton, which according to mineralogical, geochemical and isotopic criteria belong to anorogenic, non-diamondiferous type of lamproites. According to the geologic relationships, they cut through the Noril'sk-1 intrusion of the Siberian flood basalt province and thus are younger than ~251 Ma. 40Ar/39Ar dating of the two dykes yielded ages of 235.24 ± 0.19 Ma and 233.96 ± 0.19 Ma, showing that they were emplaced in Carnian of the Late Triassic, about 16 Ma after the flood basalt event. There are some indications that there were multiple lamproitic dyke emplacements, including probably emplacement of diamondiferous lamproites, which produced Carnian-age diamond-rich placer deposits in other parts of the Siberian Craton and in adjacent regions. Lead isotope modelling shows that the source of the studied lamproites was formed with participation of recycled crust, which underwent modification of its U/Pb ratio as early as 2.5 Ga. However, the exactmechanismof the recycling cannot be deciphered now. It could be either through delamination of the cratonic crust or subduction of amix of ancient terrigenous sediments into the mantle transition zone.
DS201902-0294
2018
Savatenkov, V.M.Malyeshev, S.V., Pasenko, A.M., Ivanov, A.V., Gladkochub, D.P., Savatenkov, V.M., Meffre, S., Abersteiner, A., Kamenetsky, V.S., Shcherbakov, V.D.Geodynamic significance of the Mesoproterozoic magmatism of the Udzha paleo-rift ( Northern Siberian craton) based in U-Pb geochronology and paleomagnetic data.Minerals ( mdpi.com), Vol. 8, 12, 11p. PdfRussia, Siberiacraton

Abstract: The emplacement age of the Great Udzha Dyke (northern Siberian Craton) was determined by the U-Pb dating of apatite using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). This produced an age of 1386 ± 30 Ma. This dyke along with two other adjacent intrusions, which cross-cut the sedimentary units of the Udzha paleo-rift, were subjected to paleomagnetic investigation. The paleomagnetic poles for the Udzha paleo-rift intrusions are consistent with previous results published for the Chieress dyke in the Anabar shield of the Siberian Craton (1384 ± 2 Ma). Our results suggest that there was a period of intense volcanism in the northern Siberian Craton, as well as allow us to reconstruct the apparent migration of the Siberian Craton during the Mesoproterozoic.
DS201903-0520
2019
Savatenkov, V.M.Ivanov, A.V., Levitskii, I.V., Levitskii, V.I., Corfu, F., Demonterova, E.I., Reznitskii, L.Z., Pavlova, L.A., Kamenetsky, V.S., Savatenkov, V.M., Powerman, V.I.Shoshonitic magmatism in the Paleoproterozoic of the south-western Siberian Craton: an analogue of the modern post-collisiion setting.Lithos, Vol. 328-329, pp. 88-100.Russiadeposit - Sharyzhalgay

Abstract: The Siberian Craton was assembled in a Paleoproterozoic episode at about 1.88?Ga by the collision of older blocks, followed at about 1.86?Ga by post-collisional felsic magmatism. We have found a set of extremely fresh mica-bearing lamprophyre-looking rocks within the Sharyzhalgay metamorphic complex of the south-western Siberian Craton. Zircon from these rocks yields a UPb TIMS age of 1864.7?±?1.8?Ma, which coincides perfectly with the peak of the post-collisional granite ages and postdates by ~15?Ma the peak of ages obtained for metamorphism. The same ages were reported earlier for a mafic dyke with ocean island basalt (OIB) geochemical signatures and a Pt-bearing mafic-ultramafic intrusion found in the same region. Mineralogy, major and trace element geochemistry and Sr-Nd-Pb isotopes show that the studied rocks (1) have shoshonitic affinity, (2) are hybrid rocks with mineral assemblages which could not be in equilibrium, (3) where derived by recycling of an Archean crustal source and (4) resemble post-collision Tibetan shoshonitic series. The genesis of these rocks is considered to be due to melting of crustal lithologies and metasomatized lithospheric mantle within a subducted slab. Some of the resulting melts ascended through the lithospheric column and fractionated to low-Mg absarokites, whereas other melts were contaminated by orthopyroxenitic mantle material and attained unusual high-Mg mafic compositions. According to our model, the post-collisional magmatism (shoshonite- and OIB-type) occurred due to upwelling of hot asthenosphere through a slab window, when the active collision ceased as a result of the slab break off and loss of the slab pull force. Overall, our study shows that in the Paleoproterozoic shoshonitic melts were emplaced within a similar tectonic setting as seen today in modern orogenic systems.
DS1984-0628
1984
Savchenk, N.A.Savchenk, N.A., Omelchen, V.D.Deep Structure of the Manevichskii Block of the Pripat Bar (according to Geologo-geophysical Data).Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 278, No. 1, PP. 184-188.RussiaTectonics
DS201510-1797
2015
Savchenko, A.S.Pashkevich, I.K., Savchenko, A.S., Starostenko, V.I., Sharov, N.V.A three dimensional geophysical model of the Earth's crust in the central part of the Karelian Craton.Doklady Earth Sciences, Vol. 463, 2, pp. 808-812.RussiaGeophysics
DS201112-1176
2010
Savchenko, E.E.Zozulya, D.R., Savchenko, E.E., Kullerud, K., Ravna, E.K., Lyalina, L.M.Unique accessory Ti-Ba-P mineralization in the Kvaloya ultrapotassic dike, northern Norway.Geology of Ore Deposits, Vol. 52, 8, pp. 843-851.Europe, NorwayMineral chemistry corresponds to lamproite
DS201912-2795
2019
Savchenko, E.E.Krivovichev, S.V., Yakovenchuk, V.N., Panikorovskii, T.L., Savchenko, E.E., Pakhailova, Yu, A., Selivanova, E.A., Kadyrova, G.I., Ivanyuk, G.Yu.,Krivovchev, S.V.Nikmelnikovite: Ca 12 Fe 2+ Fe 3+3 Al3(SiO4) 6(OH)20: a new mineral from the Kovdor Massif ( Kola Peninsula, Russia)Doklady Earth Sciences, Vol. 488, 2, pp. 1200-1202.Russia, Kola Peninsuladeposit - Kovdor
DS1986-0705
1986
Savchenko, M.A.Savchenko, M.A.Accessory diamond in alluvium of the Pripet Swell.(Russian)Dopov. Akad. Nauk. Ukr. Ser. B.(Russian), Vol. 1986, No. 9, pp. 25-27RussiaPlacers, Diamond
DS1996-0082
1996
Savchenko, Y.E.Barkov, A.Y., Savchenko, Y.E., et al.Loveringite from the last Yavr mafic ultramafic intrusion, Kola Peninsula:a second occurrence, RussiaNorsk Geol. Tidssk, Vol. 76, No. 2, pp. 115-120Russia, Kola PeninsulaLayered intrusion, Petrology
DS201508-0368
2015
Savchenko, Ye.Lyalina, L., Zolotarev, A.Jr., Selivanova, E., Savchenko, Ye., Zozulya, D., Krivovichev, S., Mikhailova, Yu.Structural characterization and composition of Y-rich hainite from Sakharojok nepheline syenite pegmatite ( Kola Peninsula, Russia).Mineralogy and Petrology, Vol. 109, 4, pp. 443-451.Russia, YakutiaNepheline syenite
DS1998-1286
1998
Savelev, A.A.Savelev, A.A.Mafic ultramafic rocks in the Paleozoic margin of the East Europeancontinent, Polar Urals.Doklady Academy of Sciences, ol. 358, No. 1, pp. 51-54.Russia, UralsUltramfic rocks
DS2000-0859
2000
Saveleva, V.B.Saveleva, V.B., Zyryanov, A.S.Alkaline metasomatic rocks of the main Sayan fault zoneDoklady Academy of Sciences, Vol. 371, No. 2, pp. 318-21.RussiaMagmatism - alkaline
DS201502-0095
2014
Saveleva, V.B.Saveleva, V.B., Bazarova, E.P., Danilov, B.S.New finds of carbonatite like rocks in the western Baikal region.Doklady Earth Sciences, Vol. 459, 2, pp. 1483-1487.RussiaCarbonatite
DS201712-2686
2017
Saveleva, V.B.Gladkochub, D.P., Donskaya, T.V., Sklyarov, E.V., Kotov, A.B., Vladykin, N.V., Pisarevsky, S.A., Larin, A.M., Salnikova, E.B., Saveleva, V.B., Sharygin, V.V., Starikova, A.E., Tolmacheva, E.V., Velikoslavinsky, S.D., Mazukabzov, A.M., Bazarova, E.P., KovaThe unique Katugin rare metal deposit ( southern Siberia): constraints on age and genesis.Ore Geology Reviews, in press available, 18p.Russia, Siberiadeposit - Katugin

Abstract: We report new geological, mineralogical, geochemical and geochronological data about the Katugin Ta-Nb-Y-Zr (REE) deposit, which is located in the Kalar Ridge of Eastern Siberia (the southern part of the Siberian Craton). All these data support a magmatic origin of the Katugin rare-metal deposit rather than the previously proposed metasomatic fault-related origin. Our research has proved the genetic relation between ores of the Katugin deposit and granites of the Katugin complex. We have studied granites of the eastern segment of the Eastern Katugin massif, including arfvedsonite, aegirine-arfvedsonite and aegirine granites. These granites belong to the peralkaline type. They are characterized by high alkali content (up to 11.8?wt% Na2O?+?K2O), extremely high iron content (FeO?/(FeO??+?MgO)?=?0.96-1.00), very high content of most incompatible elements - Rb, Y, Zr, Hf, Ta, Nb, Th, U, REEs (except for Eu) and F, and low concentrations of CaO, MgO, P2O5, Ba, and Sr. They demonstrate negative and CHUR-close ?Nd(t) values of 0.0…?1.9. We suggest that basaltic magmas of OIB type (possibly with some the crustal contamination) represent a dominant part of the granitic source. Moreover, the fluorine-enriched fluid phases could provide an additional source of the fluorine. We conclude that most of the mineralization of the Katugin ore deposit occurred during the magmatic stage of the alkaline granitic source melt. The results of detailed mineralogical studies suggest three major types of ores in the Katugin deposit: Zr mineralization, Ta-Nb-REE mineralization and aluminum fluoride mineralization. Most of the ore minerals crystallized from the silicate melt during the magmatic stage. The accessory cryolites in granites crystallized from the magmatic silicate melt enriched in fluorine. However, cryolites in large veins and lens-like bodies crystallized in the latest stage from the fluorine enriched melt. The zircons from the ores in the aegirine-arfvedsonite granite have been dated at 2055?±?7?Ma. This age is close to the previously published 2066?±?6?Ma zircon age of the aegirine-arfvedsonite granites, suggesting that the formation of the Katugin rare-metal deposit is genetically related to the formation of peralkaline granites. We conclude that Katugin rare-metal granites are anorogenic. They can be related to a Paleoproterozoic (?2.05?Ga) mantle plume. As there is no evidence of the 2.05?Ga mantle plume in other areas of southern Siberia, we suggest that the Katugin mineralization occurred on the distant allochtonous terrane, which has been accreted to Siberian Craton later.
DS202112-1944
2021
Saveleva, V.B.Saveleva, V.B., Danilova, Y.,Bazarova, E.P., Danilov, B.S.Kimberlite-like rocks of the Urik-Iya graben, eastern Sayan region: mineral composition, geochemistry and formation conditions.Geodynamics & Tectonophysics, Vol. 11, 4, pp. 678-696.Russiadeposit - Sayan

Abstract: The study of the Bol’shaya Tagna alkaline-carbonatite massif and adjacent areas was focused on the mineral and chemical compositions of minerals, the distribution of petrogenic and trace elements in pyroxene-free alkaline picrites in veins and dikes dated at the late Riphean (circa 645 Ma), and comparison with the Bushkanai kimberlite-picrite dike. Phenocrysts in the pyroxene-free picrites are represented by olivine (replaced with serpentine) and phlogopite; the bulk is formed by serpentine, phlogopite, monticellite, calcite, etc .; xenocrysts of pyrope and chrome diopside are absent. Phlogopite and Cr-spinel from the picrites are chemically similar to these minerals in kimberlites, but the evolution of the spinel compositions corresponds to the titanomagnetite trend; monticellite is depleted in forsterite (Mg2SiO4). The rocks contain strontianite, burbankite, titanium andradite, calcirtite and Mn-ilmenite, which are not typical of kimberlites, but are inherent in carbonate-bearing ultramafic lamprophyres, ayllikites. The pyroxene-free picrites have low contents (wt %) of SiO2 (28.4?33.2), Al2O3 (3.2?5.6), and Na2O (0.01?0.05); relatively high contents of TiO2 (2.0?3.3), and ?2? (0.45?1.33); varying contents of MgO (16.1?24.1), ??? (12.9?22.8), ??2 (1.1?12.2), Ni (260?850 ppm), and Cr (840?2200 ppm); and Mg#=0.73?0.80. The contents of Th, U, Nb, Ta, La, and Ce in the veins are approximately two orders higher than those in the primitive mantle; the spectra of trace elements differ from the spectra of the South African and Yakuian kimberlites. In the pyroxene-free picrites and the rocks of the Bushkanai dike, the Nb/U, Nb/Th, Th/Ce, La/Nb, and Zr/Nb ratios are similar to those in ocean island basalts (OIB) and thus give evidence of the leading contribution of the recycled component into the source melt. In experiments conducted to investigate melting of carbonated garnet lherzolite, the pyroxene-free alkaline picrites melted at 5-6 GPa.
DS201711-2527
2017
Saveliev, D.E.Saveliev, D.E., Puchkov, V.N., Sergeev, S.N., Misabirov, I.I.Deformation induced decomposition of enstatite in mantle peridotite and its role in partial melting and chromite ore formation.Doklady Earth Sciences, Vol. 476, 1, pp. 1058-1061.Mantleperidotite

Abstract: Deformed orthopyroxene grains are studied in detail in mantle peridotite. It is shown that deformation of enstatite is accompanied by its decomposition with the formation of low-temperature phases (pargasite, Fe-rich olivine) and restite represented by depleted enstatite, forsterite, and small newly formed chrome spinellide grains. The role of plastic deformation in initiation of partial melting of peridotite and in the formation new chrome spinellide grains is discussed.
DS1996-1253
1996
Savelieva, G.N.Savelieva, G.N., Nesbitt, R.W.A synthesis of the stratigraphic and tectonic setting of the UralianophiolitesJournal of the Geological Society of London, Vol. 153, pp. 525-537GlobalOphiolites, Tectonics
DS200512-0938
2004
Savelieva, G.N.Savelieva, G.N.Structure of the mantle crust transitional zone in modern and ancient spreading centers, the central Atlantic and Polar Urals.Geotectonics, Vol. 38, 4, pp. 241-254.Russia, UralsTectonics
DS200912-0669
2008
Savelieva, G.N.Savelieva, G.N., Sobolev, A.V., Batanova, V.G., Suslov, P.V., Brugmann, G.Structure of melt flow channels in the mantle.Geotectonics, Vol. 42, 6, pp. 430-447.MantleMelting
DS201502-0041
2014
Savelieva, G.N.Batanova, V.G., Lyaskovskaya, Z.E., Savelieva, G.N., Sobolev, A.V.Peridotites from the Kamchatsky Mys: evidence of oceanic mantle melting near a hotspot.Russian Geology and Geophysics, Vol. 55, pp. 1395-1403.RussiaHarzburgite, plumes

Abstract: A suite of mantle peridotites sampled in the Kamchatsky Mys includes spinel lherzolite, clinopyroxene-bearing harzburgite, and harzburgite. Mineral chemistry of olivine, chromian spinel, and clinopyroxene show strongly correlated element patterns typical of peridotite formed by 8% to more than 22% partial melting. Clinopyroxene in the Kamchatka peridotites is compositionally different from that of both abyssal and suprasubduction varieties: Clinopyroxene in lherzolite is depleted in LREE relative to abyssal peridotite and that in harzburgite has very low LREE and Sr unlike the subduction-related counterpart. These composition features indicate that the rocks ultra-depleted in basaltic components originated in the vicinity of a hotspot, possibly, proto-Hawaiian plume, which provided high temperature and melting degree of the MORB source mantle at mid-ocean ridge.
DS201608-1437
2016
Savelieva, G.N.Savelieva, G.N., Raznitsin, Yu.N., Merkulova, M.V.Metamorphsm of peridotites in the mantle wedge above the subduction zone: hydration of the lithospheric mantle.Doklady Earth Sciences, Vol. 468, 1, pp. 438-440.Russia, Polar UralsSubduction

Abstract: Two areas with different types of hydration (serpentinization), which occurred in two settings distinct in temperatures, pressures, and stresses, are spatially individualized in the ophiolitic ultramafic massifs of the Polar Urals. The high-temperature hydration of ultramafic rocks occurred in the lithosphere of the mantle wedge directly above the subducted slab. The initial conditions of hydration are limited to 1.2-2 GPa and 650-700°C; a stable assemblage of olivine + antigorite + magnetite ? amphibole ? talc ? chlorite was formed at 0.9-1.2 GPa and 550-600°C. The low-temperature mesh lizardite-chrysotile serpentinization occurred in the crustal, near-surface conditions. Both types of hydration were accompanied by release of hydrogen, which participates in abiogenic CH4 synthesis in the presence of CO2 dissolved in water.
DS201701-0029
2016
Savelieva, V.B.Savelieva, V.B., Danilova, Yu.V., Bazarova, E.P., Ivanov, A.V., Kamenetsky, V.S.Carbonatite magmatism of the southern Siberian Craton 1 Ga ago: evidence for the beginning of breakup of Laurasia in the early Neoproterozoic.Doklady Earth Sciences, Vol. 471, 1, pp. 1140-1143.RussiaCarbonatite

Abstract: Apatite and biotite from dolomite?ankerite and calcite?dolomite carbonatite dikes emplaced into the Paleoproterozoic metamorphic rock complex in the southern part of the Siberian Craton are dated by the U-Pb (LA-ICP-MS) and 40Ar-39Ar methods, respectively. Proceeding from the lower intercept of discordia with concordia, the age of apatite from calcite?dolomite carbonatite is estimated to be 972 ± 21 Ma and that for apatite from dolomite?ankerite carbonatite, as 929 ± 37 Ma. Values derived from their upper intercept have no geological sense. The ages obtained for biotite by the 40Ar-39Ar method are 965 ± 9 and 975 ± 14 Ma. It means that the formation of carbonatites reflects the earliest phases of the Neoproterozoic stage in extension of the continental lithosphere.
DS2003-0361
2003
Savelle, J.M.Dyke, A.S., St. Onge, D.A., Savelle, J.M.Deglaciation of southwestern Victoria Island and adjacent Arctic mainland, NunavutGeological Survey of Canada Map, No. 2027A, 1: 500,000 $ 20.NunavutGeomorphology
DS200412-0495
2003
Savelle, J.M.Dyke, A.S., St.Onge, D.A., Savelle, J.M.Deglaciation of southwestern Victoria Island and adjacent Arctic mainland, Nunavut, NWT.Geological Survey of Canada Map, No. 2027A, 1: 500,000 $ 20.Canada, NunavutMap Geomorphology
DS2000-0860
2000
Savelli, C.Savelli, C.Subduction related episodes of Potassium alkaline magmatism 15 -0.1 Ma) and geodynamic implications Tyrrhenian region:Journal of Geodynm., Vol. 30, No. 5, pp. 575-91.ItalySubduction, Review
DS1989-0803
1989
Savelyev, A.A.Knipper, A.L., Savelyev, A.A., Rukiye, M.Ophiolitic association of northwestern SyriaGeotectonics, Vol. 22, No. 1, pp. 73-82SyriaOphiolite
DS200612-0063
2005
Savelyev, D.P.Avdeiko, G.P., Savelyev, D.P.Two types of 'intra-plate' lavas on Kamchatka.Problems of Sources of deep magmatism and plumes., pp. 229-246.RussiaVolcanology
DS202008-1411
2020
Savelyev, D.P.Korneeva, A.A., Nikolai, N.A., Kamenetsky, V.S., Portnyagin, M.V., Savelyev, D.P., Krasheninnikov, S.P., Abersteiner, A., Kamenetsky, M.B., Zelenski, M.E., Shcherbakov, V.D., Botcharnikov, R.E.Composition, crystallization conditions and genesis of sulfide saturated parental melts of olivine-phyric rocks from Kamchatsky Mys ( Kamchatka, Russia).Lithos, 10.1016/j.lithos.2020.105657Russia, Kamchatkapicrites

Abstract: Sulfide liquids that immiscibly separate from silicate melts in different magmatic processes accumulate chalcophile metals and may represent important sources of the metals in Earth's crust for the formation of ore deposits. Sulfide phases commonly found in some primitive mid-ocean ridge basalts (MORB) may support the occurrence of sulfide immiscibility in the crust without requiring magma contamination and/or extensive fractionation. However, the records of incipient sulfide melts in equilibrium with primitive high-Mg olivine and Cr-spinel are scarce. Sulfide globules in olivine phenocrysts in picritic rocks of MORB-affinity at Kamchatsky Mys (Eastern Kamchatka, Russia) represent a well-documented example of natural immiscibility in primitive oceanic magmas. Our study examines the conditions of silicate-sulfide immiscibility in these magmas by reporting high precision data on the compositions of Cr-spinel and silicate melt inclusions, hosted in Mg-rich olivine (86.9-90 mol% Fo), which also contain globules of magmatic sulfide melt. Major and trace element contents of reconstructed parental silicate melts, redox conditions (?QFM = +0.1 ± 0.16 (1?) log. units) and crystallization temperature (1200-1285 °C), as well as mantle potential temperatures (~1350 °C), correspond to typical MORB values. We show that nearly 50% of sulfur could be captured in daughter sulfide globules even in reheated melt inclusions, which could lead to a significant underestimation of sulfur content in reconstructed silicate melts. The saturation of these melts in sulfur appears to be unrelated to the effects of melt crystallization and crustal assimilation, so we discuss the reasons for the S variations in reconstructed melts and the influence of pressure and other parameters on the SCSS (Sulfur Content at Sulfide Saturation).
DS1975-0379
1976
Savelyeva, G.N.Peyve, A.V., Perfilyev, A.S., Savelyeva, G.N.Depth Inclusions, Kimberlites and the Problem of Continental Drift.Sovetskaya Geologiya., No. 5, PP. 18-31.RussiaGenesis
DS1984-0629
1984
Savelyeva, G.N.Savelyeva, G.N.Mineral Assemblage Evolution in Ocean Floor UltrabasitesGeochemistry International, Vol. 21, PP. 74-86.Pacific OceanLherzolite, Harzburgite
DS201607-1312
2016
Savelyeva, V.B.Savelyeva, V.B., Demonterova, E.I., Danilova, Yu.V., Bazarova, E.P., Ivanov, A.V., Kamenetsky, V.S.New carbonatite complex in the western Baikal area, southern Siberian craton: mineralogy, age, geochemistry, and petrogenesis.Petrology, Vol. 24, 3, pp. 271-302.RussiaCarbonatite

Abstract: A dike -vein complex of potassic type of alkalinity recently discovered in the Baikal ledge, western Baikal area, southern Siberian craton, includes calcite and dolomite -ankerite carbonatites, silicate-bearing carbonatite, phlogopite metapicrite, and phoscorite. The most reliable 40Ar -39Ar dating of the rocks on magnesioriebeckite from alkaline metasomatite at contact with carbonatite yields a statistically significant plateau age of 1017.4 ± 3.2 Ma. The carbonatite is characterized by elevated SiO2 concentrations and is rich in K2O (K2O/Na2O ratio is 21 on average for the calcite carbonatite and 2.5 for the dolomite -ankerite carbonatite), TiO2, P2O5 (up to 9 wt %), REE (up to 3300 ppm), Nb (up to 400 ppm), Zr (up to 800 ppm), Fe, Cr, V, Ni, and Co at relatively low Sr concentrations. Both the metapicrite and the carbonatite are hundreds of times or even more enriched in Ta, Nb, K, and LREE relative to the mantle and are tens of times richer in Rb, Ba, Zr, Hf, and Ti. The high (Gd/Yb)CN ratios of the metapicrite (4.5 -11) and carbonatite (4.5 -17) testify that their source contained residual garnet, and the high K2O/Na2O ratios of the metapicrite (9 -15) and carbonatite suggest that the source also contained phlogopite. The Nd isotopic ratios of the carbonatite suggest that the mantle source of the carbonatite was mildly depleted and similar to an average OIB source. The carbonatites of various mineral composition are believed to be formed via the crystallization differentiation of ferrocarbonatite melt, which segregated from ultramafic alkaline melt.
DS201612-2293
2016
Savelyeva, V.B.Demonterova, E.I., Ivanov, A.V., Savelyeva, V.B.Mafic, ultramafic and carbonatitic dykes in the southern Siberian Craton with age of ca 1 Ga: remnants of a new large igneous province?Acta Geologica Sinica, Vol. 90, July abstract p. 9.Russia, SiberiaCarbonatite
DS1998-1287
1998
Savenko, A.V.Savenko, A.V.The co-precipitation of phosphorous, arsenic and vanadium with iron hydroxide in hydrothermal plumes.Doklady Academy of Sciences, Vol. 361A, No. 6, pp. 866-8.MantlePlumes
DS1990-1305
1990
Saverikko, M.Saverikko, M.Komatiitic explosive volcanism and its tectonic setting in Finland, the Fennoscandian (Baltic Shield).Bulletin. Geological Society Finland, Vol. 62, No. 1, pp. 3-38.Finland, Baltic Shieldvolcanism.
DS1975-1209
1979
Saviaro, K.Saviaro, K.Preliminary Analysis of the Airborne Magnetic Surveys in Zambia.Botswana Geological Survey, Bulletin. No. 22, PP. 159-183.GlobalRegional Tectonics, Geophysics
DS200512-0769
2005
Savitha, G.Natarajam, R., Savitha, G., Dominiak, P., Wozniak, K., Moorthy, J.N.Corundum, diamond and PtS metal organic frameworks with a difference: self assembly of a unique pair of 3-connecting D2d symmetric 3,3',5,5' tetrakis(4-pyridyl)bimesity1.Angewandie Chemie, Vol. 44, 14, March 29, pp. 2115-2119.Chemistry - framework
DS1998-0930
1998
Savitoki, S.Mancini, F., Papunen, H., Savitoki, S., Marshall, B.EPMA analyses and X-ray single crystal refinements of garnets from Arkangelsk kimberlites, northwest Russia.Petrology, Vol. 6, No. 6, Nov-Dec. pp. 546-554.Russia, Arkangelsk, Kola PeninsulaCrystallography, Garnet morphology
DS1988-0699
1988
Savitskaya, L.I.Tkachev, V.N., Iskandarkhodzhayev, T.A., Savitskaya, L.I., ShainThe Almalyk Permian strat a of the Adrasman volcanogenic structure.(Russian)Uzbekiston Geologiya Zhurnal., (Russian), No. 3, pp. 29-34RussiaNative element-diamond, Biostratigraphy
DS1995-2152
1995
Savko, A.D.Zinchuk, N.N., Savko, A.D.Comparison of weathering crusts from the East European and SiberianPlatform: implications for searching..Proceedings of the Sixth International Kimberlite Conference Almazy Rossii Sakha abstract, p. 17.Russia, Yakutia, East European PlatformAlluvials, placers, Weathering, eluviuM.
DS201112-0917
2011
Savko, A.D.Savko, A.D., Shevyrev, L.T.Analysis of the mineral composition of the Phanerozoic sediments of the Voronezh anteclise cover: implication for the primary diamond potential.Lithology and Mineral Resources, Vol. 46, 3, pp. 282-298.Russia, Archangel, Kola Peninsula, Karelia, Europe, FinlandIndicator Mineralogy
DS202107-1126
2021
Savko, K.A.Savko, K.A., Tsybulyaev, S.V., Samsonov, A.V., Bazikov, N.S., Korish, E.H., Terentiev, R.A., Panevin, V.V.Archean carbonatites and alkaline rocks of the Kursk Block, Sarmatia: age and geodynamic setting.Doklady Earth Sciences, Vol. 498, 1, pp. 412-417.Russiacarbonatite

Abstract: Neoarchean intraplate granitoid (2.61 Ga) and carbonatite magmatism are established in the Kursk block of Sarmatia in close spatial association. Alkaline pyroxenites, carbonatites, and syenites of the Dubravinskii complex are represented by two relatively large intrusions and a few small plutons. They underwent amphibolite facies metamorphism at about 2.07 Ga. The age of alkaline-carbonatite magmatism is 2.59 Ga according to SIMS isotope dating of zircon from syenites. The close age and spatial conjugation allow the Dubravinskii carbonatite complex to be considered to have formed in intraplate conditions. The mantle plume upwelling caused metasomatic alteration and consequent partial melting of the sublithospheric mantle and intrusion of enriched magmas into the crust. Contamination of alkaline mantle melts in the crust by Archean TTGs caused the formation of syenites melts in the form of dykes that cutting through pyroxenites and carbonatites.
DS202101-0007
2020
Savolainen, M.Decree, S., Savolainen, M., Mercadier, J., Debaille, V., Hohn, S., Frimmel, H., Baele, J-M.Geochemical and spectroscopic investigation of apatite in the Siilinjarvi carbonatite complex: keys to understanding apatite forming processes and assessing potential for rare earth elements.Applied Geochemistry, Vol. 123, 104778 17p. PdfEurope, Finlanddeposit - Siilinjarvi

Abstract: The Siilinjärvi phosphate deposit (Finland) is hosted by an Archean carbonatite complex. The main body is composed of glimmerite, carbonatite and combinations thereof. It is surrounded by a well-developed fenitization zone. Almost all the rocks pertaining to the glimmerite-carbonatite series are considered for exploitation of phosphate. New petrological and in-situ geochemical as well as spectroscopic data obtained by cathodoluminescence, Raman and laser-induced breakdown spectroscopy make it possible to constrain the genesis and evolution of apatite through time. Apatite in the glimmerite-carbonatite series formed by igneous processes. An increase in rare earth elements (REE) content during apatite deposition can be explained by re-equilibration of early apatite (via sub-solidus diffusion at the magmatic stage) with a fresh carbonatitic magma enriched in these elements. This late carbonatite emplacement has been known as a major contributor to the overall P and REE endowment of the system and is likely connected to fenitization and alkali-rich fluids. These fluids - enriched in REE - would have interacted with apatite in the fenite, resulting in an increase in REE content through coupled dissolution-reprecipitation processes. Finally, a marked decrease in LREE is observed in apatite hosted by fenite. It highlights the alteration of apatite by a REE-poor fluid during a late-magmatic/hydrothermal stage. Regarding the potential for REE exploitation, geochemical data combined with an estimation of the reserves indicate a sub-economic potential of REE to be exploited as by-products of phosphate mining. Spectroscopic analyses further provide helpful data for exploration, by determining the P and REE distribution and the enrichment in carbonatite and within apatite.
DS1994-0967
1994
Savostin, L.A.Kuznetsov, N.B., Bondarenko, G.Ye., Savostin, L.A.First find of alpine type ultramafics in central KamchatkaDoklady Academy of Sciences Acad. Science, Vol. 322, pp. 39-43.Russia, KamchatkaUltramafics, Peridotite
DS1993-1379
1993
Savostyanov, N.A.Savostyanov, N.A., Kashik, A.S.The geophysical market of RussiaThe Leading Edge, Vol. 12, No. 4, April pp. 275-279Russia, Commonwealth of Independent States (CIS), RussiaGeophysics
DS2001-1019
2001
Savov, I.Savov, I., Ryan, J., Haydoutov, I., Schijf, J.Late Precambrian Balkan Carpathian ophiolite - a slice of the Pan African ocean crust? geochemical, tectonicsJour. Volc. Geotherm. Res., Vol. 110, No.3-4, pp. 299-318.Bulgaria, SyriaOphiolite, Massifs - Tcherni Vrah, Deli Jovan
DS201112-0404
2011
Savov, I.P.Halama, R., Savov, I.P., Meliksetian, K.The Tezhsar alkaline complex ( Armenia).Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterEurope, ArmeniaAlkalic
DS1991-0413
1991
Savoyant, L.Dupuy, C., Mevel, C., Bodinier, J-L, Savoyant, L.Zabargad peridotite: evidence for multistage metasomatism during Red SeariftingGeology, Vol. 19, No. 7, July pp. 722-725GlobalMantle Metasomatism, Peridotites
DS200612-0744
2006
SavrasovKravchinsky, V.A., Konstantinov, Courtillot, Savrasov, Valet, Cherniy, Mishenin, ParasotkaPaleomagnetism of East Siberian traps and kimberlites: two new poles and paleogeographic reconstructions at about 360 and 250 Ma.Geophysical Journal International, Vol. 148, 1, pp. 1-33.Russia, SiberiaMaleomagnetics
DS1960-0784
1967
Savrasov, D.Balakshin, G.D., Savrasov, D., Federov, N.N.Possibilite D'emploi de Leves Aeromagnetiques Pour Les Recherches de Kimberlites et de Carbonatites En Yakoutie.Razv. I Okhr. Nedr. Sssr., Vol. 33, No. 3, PP. 43-46. French Geological Survey (BRGM) TRANSLATION No. 5368.RussiaBlank
DS1960-0293
1962
Savrasov, D.I.Savrasov, D.I.Some Notes on the Physical Properties of KimberlitesAkad. Nauk Sssr, Sib. Div. Ser. Geol., No. 12, 10P.RussiaBlank
DS1960-0395
1963
Savrasov, D.I.Savrasov, D.I.On the Application of the Paleomagnetic Method to Determine the Age of Kimberlites and Traps.In: Geology of Diamond Deposits, AKAD. NAUK SSSR, No. 9, PP. 162-17L.RussiaBlank
DS1960-0396
1963
Savrasov, D.I.Savrasov, D.I., Ilupin, I.P.The Use of Magnetic Prospecting Methods in Mapping the Different Types of Kimberlites in Pipes of Complex Structure.Geologii i Geofiziki, No. 8, PP. 96-L00. French Geological Survey (BRGM) TRANSLATION No. 5367.RussiaBlank
DS1970-0115
1970
Savrasov, D.I.Krivonos, V.F., Ilupin, I.P., Savrasov, D.I.New Methods of Estimating the Age of Kimberlites with the Lena Region As Example, Northeast Siberian PlatformIn: Geology, Petrography And Mineralogy of Magmatic Formatio, PP. 67-75.RussiaBlank
DS1970-0235
1971
Savrasov, D.I.Balakshin, G.D., Savrasov, D.I.Effectiveness of Ground and Airborne Magnetic Surveys in Exploration for Kimberlite Pipes.Razved. Okhr. Nedr. Sssr., No. 3, PP. 45-50.Russia, YakutiaKimberlite, Geophysics
DS1970-0407
1971
Savrasov, D.I.Savrasov, D.I.Inclusions of Trap Rock Kimberlites Of the Malo-botuobia Region.Akad. Nauk Sssr Sib. Otd. Institute Zemnoy Kory Irkutsk, RussiaBlank
DS1975-1210
1979
Savrasov, D.I.Savrasov, D.I., Kharkiv, A.D.Density of Xenoliths of Deep Rocks from Kimberlites of the Obnazhennaya Pipe and Density Model of Upper Mantle.Akad. Nauk Sssr Geol. Ser., Vol. 11, PP. 45-56.RussiaKimberlite Genesis
DS1983-0353
1983
Savrasov, D.I.Kharkiv, A.D., Nikishov, K.N., Safronov, A.F., Savrasov, D.I.Genesis of Amphibolized Plutonic Xenoliths from the Obnazhennaya Kimberlite PipeDoklady Academy of Science USSR, Earth Science Section., Vol. 262, No. 1-6, PP. 142-146.RussiaMineral Chemistry, Analyses, Garnet Lherzolite
DS1984-0740
1984
Savrasov, D.I.Trukhin, V.I., Zhilyaeva, A.A., Zhilyayeva, V.A., Savrasov, D.I.Self reversal of thermoremanent magnetization in rocks from Yakutian kimberlite pipes.(Russian)Physics of the Solid Earth, Vol. 20, No. 11, pp. 849-857GlobalGeophysics
DS1984-0742
1984
Savrasov, D.I.Trukhin, V.I., Zhilyaye, V.A., Savrasov, D.I., et al.Self Reversal of Thermoremanent Magnetization in Rocks From the Yakutia Kimberlite Pipes.Geologii i Geofiziki, No. 11, NOVEMBER PP. 78-89.RussiaGeophysics, Kimberlite
DS1985-0337
1985
Savrasov, D.I.Kharkiv, A.D., Nikishov, K.N., Safronov, A.F., Savrasov, D.I.Plutonic Metasomatism of Zoned Mantle Xenoliths from the Obnazhennaya Kimberlite Pipe.Doklady Academy of Science USSR, Earth Science Section., Vol. 271, No. 1-6, PP. 153-156.RussiaXenoliths, Mineralogy
DS1985-0338
1985
Savrasov, D.I.Kharkiv, A.D., Nikishov, K.N., Safronov, A.F., Savrasov, D.I.Plutonic metasomatism of zoned mantle xenoliths from the Obnazhennaya kimberlite pipeDoklady Academy of Science USSR, Earth Science Section, Vol. 271, No. 1-6, January pp. 153-156RussiaBlank
DS1985-0681
1985
Savrasov, D.I.Trukhin, V.I., Zhilyayeva, V.A., Katerenchuk, A.V., Savrasov, D.I.The Magnetism of Rocks from the Yakutia Kimberlite PipesPhysics of the Solid Earth, Vol. 20, No. 9, April pp. 689-698RussiaGeophysics
DS1986-0265
1986
Savrasov, D.I.Garanin, V.K., Zhilyaeva, V.A., Kudyavtskaya, G.P., Savrasov, D.I.Fanciful cuts created by laser sawingGems and Gemology, Vol. XXII Fall, p. 170GlobalDiamond cutting
DS1986-0266
1986
Savrasov, D.I.Garanin, V.K., Zhilyaeva, V.A., Kudyavtskaya, G.P., Savrasov, D.I.Mineralogical factors of magnetism of kimberlite rocks.(Russian)Izvest. Annual Nauka Geol., (Russian), No. 11, November pp. 82-100RussiaGeophysics
DS1986-0457
1986
Savrasov, D.I.Kostrovitskiy, S.I., Molchanov, Yu.D., Savrasov, D.I.Linear zoning and tectonic control of kimberlite fieldsDoklady Academy of Science USSR, Earth Science Section, Vol. 277, March, No. 1-6, pp. 115-119RussiaDaldyn, Malaya Botuobaya, Distribution, Tectonics, Structure
DS1986-0706
1986
Savrasov, D.I.Savrasov, D.I.Bedding conditions of kimberlite pipes of the Malobotuobinskii region and erosional shearingSoviet Geology and Geophysics, Vol. 27, No. 12, pp. 48-54RussiaStructure, Placers, Morphology
DS1987-0651
1987
Savrasov, D.I.Savrasov, D.I.Determination of the age kimberlites in the Yakut diamond bearing province by the paleomagnetic methodDoklady Academy of Science USSR, Earth Science Section, Vol. 296, No. 5, Sept-Oct. pp. 106-109RussiaGeophysics -magnetics, Paleomagnetics
DS1987-0652
1987
Savrasov, D.I.Savrasov, D.I.Assessment of the age of kimberlites of Yakutian Diamondiferous province by the paleomagnetic method. (Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 296, No. 5, pp. 1195-1198RussiaPaleomagnetism
DS1989-1344
1989
Savrasov, D.I.Savrasov, D.I.Determination of the age of kimberlites in the Yakut diamond bearing province by the paleomagnetic methodDoklady Academy of Science USSR, Earth Science Section, Vol. 296, No. 1-6, pp. 106-108RussiaDeposit -Yakut area Geochronology, Paleomagnetics
DS1995-2146
1995
Savrasov, D.I.Zhitkov, A.N., Savrasov, D.I.Paleomagnetism and the ages of kimberlites exemplified by the four pipes ofYakutia.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 695-697.Russia, YakutiaPaleomagnetics
DS1984-0424
1984
Savroasov, D.I.Kostrovitskii, S.I., Molchanov, I.D., Savroasov, D.I.A Linear Zoning and Tectonic Control of Kimberlite FieldsDoklady Academy of Sciences AKAD. NAUK SSSR., Vol. 277, No. 5, PP. 1200-1204.RussiaTectonics
DS2000-0078
2000
SavvaBelyatsky, B.V., Tikhomirova, SavvaRUbidium-Strontium and Samarium-neodymium isotope characteristics of Proterozoic carbonatite of Tiksheozero Massif... Northern Karelia.Igc 30th. Brasil, Aug. abstract only 1p.Russia, KareliaGeochronology, isochrons, Carbonatite
DS201412-0003
2014
Savva, D.Agard, P., Zuo, X., Funiciello, F., Bellahsen, N., Faccenna, C., Savva, D.Obduction: why, how and where. Clues from analog models.Earth and Planetary Science Letters, Vol. 393, pp. 132-145.MantleSubduction
DS200612-1427
2006
Savva, E.V.Tichomirowa, M., Grosche, G., Gotze, J., Belyatsky, B.V., Savva, E.V., Keller, J., Todt, W.The mineral isotope composition of two Precambrian carbonatite complexes from the Kola Alkaline Province - alteration versus primary magmatic signatures.Lithos, In press available,Russia, Kola PeninsulaCarbonatite, geochronology, Tiksheozero, Siilinkarvi
DS200812-0039
2008
Savva, E.V.Antonov, A.V., Belyatsky, B.V., Savva, E.V., Rodonov, N.V., Sergeev, S.A.Hydrothermal zircon from Proterozoic carbonatite massif.Goldschmidt Conference 2008, Abstract p.A29.Russia, KareliaTiksheozero
DS201012-0666
2010
Savva, E.V.Savva, E.V., Belyatsky, B.V., Antonov, A.V.Carbonatitic zircon - geochemical analysis. Mud Tank, Kovdor examples.International Mineralogical Association meeting August Budapest, abstract p. 576.Australia, Russia, Antarctica, globalCarbonatite
DS200612-0734
2005
Savvaitov, A.S.Korpechkov, D.I., Hodrireva, V.A., Savvaitov, A.S.Minerals of the kimberlitic assemblage in terrigenous sediments of Latvia and perspectives of its diamond potential.Lithology and Mineral Resources, Vol. 40, 8, Nov. pp. 528-536.Europe, LatviaGeochemistry, KMA, Upper Devonian
DS1985-0765
1985
Savvakin, G.I.Zhurakovskii, E.A., Trefilov, V.I., Zaulichn, J.V., Savvakin, G.I.Electron energy spectrum pecularities in ultradispersive diamonds obtained from extremely nonequilibrium carbon plasma.(in Russian)Doklady Academy of Sciences Nauk USSR, (Russian), Vol. 284, No. 6, pp. 1360-1365RussiaGenesis, Diamond Morphology
DS1989-1510
1989
Savvakin, G.I.Trefilov, V.I., Mikhalenkov, V.S., Savvakin, G.I., Tsapko, E.A.Structural char. of ultrafine diamonds and hypothetical mechanism of their formation under nonequil conditions of detonating carbon.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 305, No. 1, pp. 85-90RussiaDiamond synthesis
DS1988-0612
1988
Savvides, N.Savvides, N.Diamond growth from the vapor phaseMater. Sci. forum, Volume, pp. 34-36GlobalDiamond filM., CVD.
DS202107-1101
2018
Saw, A.K.Guha, A., Rani, K., Varma, C.B., Sarwate, N.K., Sharma, N., Mukherjee, A., Kumar, K.V., Pal, S.K., Saw, A.K., Jha, S.K.Identification of potential zones for kimberlite exploration - an Earth observation approach. ChhatarpurThe International Achives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol. XLII-5 12p. PdfIndia, Madhya PradeshASTER, lineament

Abstract: In the present study, we have prepared the thematic evidence layers for identifying the potential zones of kimberlite emplacement in parts of Chhatarpur district, Madhya Pradesh. These thematic layers or evidence layers are geological structure, alteration zones, lineament density, surface alteration and geomorphic anomaly and these layers are prepared from the remote sensing data. As orientation of the geological structures (i.e fault system) and their density have the major role in the emplacement of kimberlite; both of these evidence layers are integrated using "AND" Boolean Logical Operator. On the other hand, two evidential layers regarded as the proxy to indicate the "surface expressions on kimberlite (i.e. alteration zones and geomorphic anomaly) are combined using "OR" operator as either of these two surface expression is indicative of kimberlite. Consequently, conjugate evidence layers on the surface expressions of kimberlite are integrated with the causative evidence layers of kimberlite emplacement using "AND" operator to identify the potential zones of diamond occurrences. Potential zones of kimberlite are overlaid on the residual gravity anomaly map derived from space-based gravity model of European Improved Gravity of Earth by New Technique (EIGEN6C4) to relate potential zones of kimberlite with the similar structural alignment (delineated in the residual gravity map) of known occurrence of kimberlite. We also have carried out indicator mineral survey around these potential zones and some of the kimberlite specific indicator minerals are identified in the stream sediments within these potential zones.
DS1996-1254
1996
Saw james Capel LimitedSaw james Capel LimitedAustralian diamond update. overview Auridiam, Striker, Moonstone, Kimberely, Ocean Resources, Diamond VenturesSaw James Capel Limited, 24p.AustraliaNews item, Companies
DS1992-1333
1992
Saw James LimitedSaw James LimitedZimbabwe diamonds -renewed interest.... extracted from David Russellreport.Saw James Limited, June 18, 5p.ZimbabweNews item, Redaurum Red Lake Mines Limited, AuridiaM.
DS1993-1380
1993
Saw James LimitedSaw James LimitedAuridiam -an existing diamond play in a very prospective areaSaw James Limited, August 27, 2p.ZimbabweNews item, Auridiam Consolidated N.L.
DS2001-0560
2001
Sawada, Y.Kabeto, K., Sawada, Y., Lizumi, S., Wakatsuki, T.Mantle sources and magma crust interactions in volcanic rocks from northern Kenya Rift: geochemical evidenceLithos, Vol. 56, No. 2-3, Mar. pp. 111-39.KenyaGeochronology
DS2001-0561
2001
Sawada, Y.Kabeto, K., Sawada, Y., Wakatsuki, T.Different evolution trends in alkaline evolved lavas from the Northern Kenya riftJournal of African Earth Science, Vol. 32, No. 3, Apr. pp. 419-33.KenyaTectonics, Alkaline lavas
DS200812-0712
2008
Sawada, Y.Manthilake, M.A.G.M., Sawada, Y., Sakai, S.Genesis and evolution of Eppawala carbonatites, Sri Lanka.Journal of Asian Earth Sciences, Vol. 32, 1,feb. 15, pp. 66-75.Asia, Sri LankaCarbonatite
DS1990-0197
1990
Sawaf, T.Best, J.A., Barazangi, M., Al-Saad, D., Sawaf, T., Gebran, A.Bouguer gravity trends and crustal structure of the Palmyride Mountain Belt and surrounding northern Arabian platform in SyriaGeology, Vol. 18, No. 12, December pp. 1235-1239SyriaGeophysics -gravity, Craton
DS1993-1410
1993
Sawaf, T.Seber, D., Barazangi, M., Chamov, T.A., Al-Saad, D., Sawaf, T., Khaddour, M.Upper crustal velocity structure and basement morphology beneath theGeophysical Journal International, Vol. 113, pp. 752-766.SyriaGeophysics -seismics, Tectonics
DS201908-1811
2019
Sawaki, Y.Santosh, M., Maruyama, S., Sawaki, Y., Meert, J.G.The Cambrian explosion: plume-driven birth of the second ecosystem on Earth. Gondwana Research, doi.org/10.1016 /j.gr.2013.03.013 21p. PdfAfrica, Mozambiquetectonics

Abstract: The birth of modern life on Earth can be linked to the adequate supply of nutrients into the oceans. In this paper, we evaluate the relative supply of nutrients into the ocean. These nutrients entered the ocean through myriad passageways, but primarily through accelerated erosion due to uplift. In the ‘second ecosystem’, uplift is associated with plume-generation during the breakup of the Rodinia supercontinent. Although the evidence is somewhat cryptic, it appears that the second ecosystem included the demospongia back into the Cryogenian (~ 750 Ma). During the Ediacaran-Cambrian interval, convergent margin magmatism, arc volcanism and the closure of ocean basins provided a second pulse of nutrient delivery into the marine environment. A major radiation of life forms begins around 580 Ma and is represented by the diverse and somewhat enigmatic Ediacaran fauna followed by the Cambrian Explosion of modern phyla during the 540-520 Ma interval. Tectonically, the Ediacaran-Cambrian time interval is dominated by the formation of ultra-high pressure (UHP), high pressure (HP) and ultra-high temperature (UHT) orogenic belts during Gondwana orogenesis. Erosion of this extensive mountainous region delivered vast nutrients into the ocean and enhanced the explosiveness of the Cambrian radiation. The timing of final collisional orogeny and construction of the mountain belts in many of the Gondwana-forming orogens, particularly some of those in the central and eastern belts, post-date the first appearance of modern life forms. We therefore postulate that a more effective nutrient supply for the Cambrian radiation was facilitated by plume-driven uplift of TTG crust, subsequent rifting, and subduction-related nutrient systems prior to the assembly of Gondwana. In the outlined scenario, we propose that the birth of the ‘second ecosystem’ on our planet is plume-driven.
DS201312-0470
2013
Sawant, S.S.Khanna, T.C., Sesha Sai, V.V., Zhao, G.C., Subba Rao, D.V., Krishna, K.A., Sawant, S.S., Charan, .N.Petrogenesis of mafic alkaline dikes from Mahbubnagar large igneous province, eastern Dharwar craton, India: geochemical evidence for uncontaminated intracontinental mantle derived magmatism.Lithos, Vol. 179, pp. 84-98.IndiaAlkaline rocks, dykes
DS201707-1361
2017
Sawant, S.S.Saha, A., Ganguly, S., Ray, J., Koeberl, C., Thoni, M., Sarbajna, C., Sawant, S.S.Petrogenetic evolution of Cretaceous Samchampi Samteran alkaline complex, Mikir Hills, northeast India: implications on multiple melting events of heterogeneous plume and metasomatized sub continental lithospheric mantle.Gondwana Research, Vol. 48, pp. 237-256.Indiacarbonatite

Abstract: The Samchampi (26° 13?N: 93° 18?E)-Samteran (26° 11?N: 93° 25?E) alkaline complex (SSAC) occurs as an intrusion within Precambrian basement gneisses in the Karbi-Anglong district of Assam, Northeastern India. This intrusive complex comprises a wide spectrum of lithologies including syenite, ijolite-melteigite, alkali pyroxenite, alkali gabbro, nepheline syenite and carbonatite (nepheline syenites and carbonatites are later intrusives). In this paper, we present new major, trace, REE and Sr-Nd isotope data for different lithologies of SSAC and discuss integrated petrological and whole rock geochemical observations with Sr-Nd isotope systematics to understand the petrogenetic evolution of the complex. Pronounced LILE and LREE enrichment of the alkaline-carbonatite rocks together with steep LREE/HREE profile and flat HREE-chondrite normalized patterns provide evidence for parent magma generation from low degree partial melting of a metasomatized garnet peridotite mantle source. LILE, HFSE and LREE enrichments of the alkaline-silicate rocks and carbonatites are in agreement with the involvement of a mantle plume in their genesis. Nb-Th-La systematics with incompatible trace element abundance patterns marked by positive Nb-Ta anomalies and negative K, Th and Sr anomalies suggest contribution from plume-derived OIB-type mantle with recycled subduction component and a rift-controlled, intraplate tectonic setting for alkaline-carbonatite magmatism giving rise to the SSAC. This observation is corroborated by enriched 87Sr/86Srinitial (0.705562 to 0.709416) and 143Nd/144Ndinitial (0.512187 to 0.512449) ratios for the alkaline-carbonatite rocks that attest to a plume-related enriched mantle (~ EM II) source in relation to the origin of Samchampi-Samteran alkaline complex. Trace element chemistry and variations in isotopic data invoke periodic melting of an isotopically heterogeneous, metasomatized mantle and generation of isotopically distinct melt batches that were parental to the different rocks of SSAC. Various extents of plume-lithosphere interaction also accounts for the trace element and isotopic variations of SSAC. The Srinitial and Ndinitial (105 Ma) isotopic compositions (corresponding to ?Nd values of ? 6.37 to ? 1.27) of SSAC are consistent with those of Sung Valley, Jasra, Rajmahal tholeiites (Group II), Sylhet Traps and Kerguelen plateau basalts.
DS1983-0591
1983
Sawata, H.Sungawa, I., Horita, S., Sawata, H.Surface Microtopography of Diamonds from Thailand.*jpnHoseki Gakkaishi, *JPN., Vol. 10, No. 1-2, pp. 3-35GlobalDiamond, Morphology
DS1999-0420
1999
Sawatsky, L.Long, D., Sawatsky, L., Ekanayake, S.Potential oversights and common errors in analyzing northern hydrology: acommended approach ....Mining in the Arctic, Udd and Keen editors, Balkema, pp. 85-89.Northwest TerritoriesMining - hydrology, Deposit - Diavik
DS2003-1216
2003
Sawbridge, M.Sawbridge, M.An ensemble view of Earth's inner coreScience, Vol. 299, 5606, Jan 24, p. 529.MantleCore boundary
DS2000-0245
2000
Sawger, C.P.Drummond, B.J., Goleby, B.R., Sawger, C.P.Crustal signature of Late Archean tectonic episodes in the Yilgarn Craton:evidence from deep seismic soundingTectonophysics, Vol. 329, No. 1-4, Dec. 31, pp. 193-222.AustraliaGeophysics - seismics, Tectonics - craton
DS200812-1009
2008
Sawkar, R.H.Sawkar, R.H., FareeduddinTraining in diamond exploration. Course organized by Geological Society of India , Rio Tinto India et al. Leaders Mitchell and Coopersmith. Brief overview.Journal of Geological Society of India, Vol. 71, April pp. 453=458.IndiaBrief - review of training course held Jan 2008
DS200812-1010
2008
Sawkar, R.H.Sawkar, R.H., FareeduddinTraining in diamond exploration.Journal of Geological Society of India, Vol. 71, 4, pp. 453-458.IndiaTechnology
DS200912-0169
2009
Sawkar, R.H.Devaraju, T.C., Viljoen, R.P., Sawkar, R.H., Sudhakara, T.L.Mafic and ultramafic magmatism and associated mineralization in the Dharwar Craton, southern India.Journal of the Geological Society of India, Vol. 73, 1, pp. 73-100.IndiaMagmatism
DS200912-0210
2008
Sawkar, R.H.Fareeduddin, Sawkar, R.H.Ninth International Kimberlite Conference - brief overview.Journal of the Geological Society of India, Vol. 72, 6, pp. 837-840.IndiaBrief overview
DS1975-0401
1976
Sawkins, F.J.Sawkins, F.J.Wide spread Continental Rifting: Some Considerations of Timing and Mechanism.Geology, Vol. 4, PP. 427-430.GlobalMid-continent
DS1986-0707
1986
Sawkins, F.J.Sawkins, F.J.The recognition of paleorifting in mid to late Proterozoic terranes:implications for the exploration geologistTransactions Geological Society of South Africa, Vol.89, pp.223-232South AfricaTectonics, Structure
DS1960-1207
1969
Sawkins, F.L.Sawkins, F.L.Chemical Brecciation, an Unrecognized Mechanism for Brecciaformation?Economic Geology, Vol. 64, PP. 613-617.GlobalBreccia
DS1860-0641
1889
Sawyer, A.R.Sawyer, A.R.Diamonds in South Africa; 1889Newcastle-undes-lyme: Dilworth, 46P.Africa, South AfricaDiamond Mining
DS1860-0677
1890
Sawyer, A.R.Sawyer, A.R.Diamonds in South African Mining at Kimberley and Transvaal Vaal RiverNorth Staffordshire Institute Min. Mech. Eng. Transactions, Vol. 10, PP. 74-116.Africa, South Africa, Griqualand WestDiamond Mining
DS1999-0383
1999
Sawyer, B.Kung, R., Sawyer, B.Shaded relief map of the Canadian Cordillera and adjacent regionsGeological Survey Open File, No. 3575, 1: 2, 400, 000 $ 20.00CordilleraMap
DS1988-0183
1988
Sawyer, D.S.Dunbar, J.A., Sawyer, D.S.Continental rifting at pre-existing lithospheric weaknessesNature, Vol. 333, No. 6172, June 2, pp. 450-451MidcontinentBlank
DS1989-0376
1989
Sawyer, D.S.Dunbar, J.A., Sawyer, D.S.How preexisting weaknesses control the style of continental breakupJournal of Geophysical Research, Vol. 94, No. B6, June 10, pp. 7278-7292GlobalTectonics, Plate tectonics
DS1993-0634
1993
Sawyer, D.S.Harry, D.L., Sawyer, D.S., Leeman, W.P.The mechanics of continental extension in western North America:Earth and Planetary Science Letters, Vol. 117, pp. 59-71Nevada, CordilleraTectonics, Structure Great Basin
DS1995-0761
1995
Sawyer, D.S.Harry, D.L., Oldow, J.S., Sawyer, D.S.The growth of orogenic belts and the role of crustal heterogeneities indecollement tectonicsGeological Society of America (GSA) Bulletin, Vol. 107, No. 12, Dec. pp. 1411-1426MantleTectonics
DS1993-0931
1993
Sawyer, E.Ludden, J., Hubert, C., Barnes, A., Milkereit, B., Sawyer, E.A three dimensional perspective on the evolution of Archean crust:LITHOPROBE seismic reflection images in the southwestern Superior ProvinceLithos, Vol. 30, No. 3-4, September pp. 357-372OntarioGeophysics -seismics, Crust
DS1995-0219
1995
Sawyer, E.Brown, M., Rushmer, T., Sawyer, E.Introduction to: mechanisms and consequences of melt segregation from crustal protolithsJournal of Geophysical Research, Vol. 100, No. B8, Aug. 10, pp. 15, 551-64MantleCrust, Melt segregation
DS1992-0115
1992
Sawyer, E.W.Benn, K., Sawyer, E.W., Bouchez, J-L.Orogen parallel and transverse shearing in the Opatica belt, Quebec:implications for the structure of the Abitibi SubprovinceCanadian Journal of Earth Sciences, Vol. 29, No. 11, November, pp. 2429-2444QuebecTectonics, Structure
DS1993-1381
1993
Sawyer, E.W.Sawyer, E.W., Benn, K.Structure of the high grade Opatica Belt and adjacent low-grade AbitibiSubprovince, Canada: an Archean mountain frontJournal of Structural Geology, Vol. 15, No. 12, December pp. 1443-1458Ontariometamorphism, Tectonics
DS1994-0394
1994
Sawyer, E.W.Davis, W.J., Gariepy, C., Sawyer, E.W.Pre 2.8 Ga crust in the Opatica gneiss belt: a potential source of detrital zircons Abitibi, PontiacGeology, Vol. 22, pp. 111-4.QuebecGeochronology
DS1994-1532
1994
Sawyer, E.W.Sawyer, E.W.Melt segregation in the continental crustGeology, Vol. 22, No. 11, November pp. 1019-1022.MantleMelt segregation
DS1995-0255
1995
Sawyer, E.W.Calvert, A.J., Sawyer, E.W., Davis, W.J., Ludden, J.N.Archean subduction inferred from seismic images of a mantle suture in the Superior Province.Nature, Vol. 375, June 22, pp. 670-674.Ontario, QuebecGeophysics -seismics, Subduction, slab, tectonics
DS2001-1020
2001
Sawyer, E.W.Sawyer, E.W.Melt segregation in the continental crust: distribution and movement of melt in anatectic rocks.Journal of Metamorphic Geology, Vol. 19, No. 3, pp. 291-310.MantleMelting
DS200812-1011
2008
Sawyer, E.W.Sawyer, E.W.Atlas of migmatites.Canadian Mineralogist Special Publication, No. 9, 387p. approx. $ 140.00 www.pubs.nrc-cnrc.gc.ca/eng/booksTechnologyBook - migmatites
DS201112-0444
2011
Sawyer, E.W.Holness, M.B., Cesare, B., Sawyer, E.W.Melted rocks under the microscope: microstructures and their interpretation.Elements, Vol. 7, 4, August pp. 247-252.TechnologyMigmatites
DS201112-0918
2011
Sawyer, E.W.Sawyer, E.W., Cesare, B., Brown, M.When the continental crust melts.Elements, Vol. 7, 4, August pp. 229-234.MantleMelting
DS200612-1230
2006
Sawyer, G.M.Sawyer, G.M., Burton, M.R.Effects of a volcanic plume on thermal imaging data.Geophysical Research Letters, Vol. 33, 14, L14311TechnologyGeothermometry
DS1992-1334
1992
Sawyer, J.B.P.Sawyer, J.B.P.Assaying in resource evaluation: the need for a clear and open mindGeological Society Special Publication, Case histories and methods in mineral, No. 63, pp. 37-45GlobalComputer, Ore reserves, geostatistics, Assaying
DS1990-1306
1990
Saxe, D.Saxe, D.Environmental lawHazardous Materials Management Magazine, Vol. 2, No. 3, June pp. 10-16CanadaEnvironment law overview, Legal
DS1990-1307
1990
Saxe, D.Saxe, D.Startling amendments to Ontario's environmental lawsHazardous Materials Management, Vol. 2, No. 5, October pp. 21-23OntarioLegal, Environment
DS1991-1506
1991
Saxe, D.Saxe, D.Taking environmental rights seriouslyHazardous Materials Management, Vol. 3, No. 4, August pp. 12-13CanadaEnvironmental, Law
DS1991-1507
1991
Saxe, D.Saxe, D.Directions in environmental regulation: where is Ontario going now?Hazardous Materials Management, December, pp. 37, 38OntarioLegal, Environmental
DS1993-1382
1993
Saxe, D.Saxe, D.Environmental offences: Corporate responsibility and executive liabilityCanada Law Book, 288pCanadaLegal -environmental, Book -ad
DS1993-1383
1993
Saxe, D.Saxe, D.Ontario environmental protection act annotatedCanada Law Book, 550pOntarioLegal -environmental, Book -ad
DS2000-0742
2000
Saxena, A.D.Pandit, M.K., Sial, A.N., Saxena, A.D., Ferreira, V.P.Non magmatic features in carbonatitic rocks: a re-examination of Proterozoic carbonatites ..RajasthanInternational Geology Review, Vol. 42, No. 11, Nov. pp. 1046-53.India, southeastCarbonatite, Indian Craton, Deposit - Newania
DS1981-0366
1981
Saxena, M.P.Saxena, M.P.Soviet Assistance for Panna Diamond MineGem World., Vol. 9, No. 9, PP. 23-24.IndiaThermochemical
DS1984-0630
1984
Saxena, M.P.Saxena, M.P., Gupta, L.N., Chaudhri, N.Carbonatite Dikes in Dhanota Dhancholi Hills, Narnaul, Haryana.Current Science., Vol. 53, No. 12, PP. 651-652.IndiaCarbonatite
DS1983-0558
1983
Saxena, S.K.Saxena, S.K., Eriksson, G.Theoretical Computation of Mineral Assemblages in Pyrolite And Lherzolite.Journal of PETROLOGY, Vol. 24, No. 4, NOVEMBER PP. 538-555.GlobalMineralogy, Chemistry
DS1985-0589
1985
Saxena, S.K.Saxena, S.K., Fei, Y.High Pressure Phase Equilibrium in the System Iron-magnesium-si-oGeological Society of America (GSA), Vol. 17, No. 7, P. 708. (abstract.).GlobalExperimental Petrology, Perovskite, Petrogenesis
DS1989-1345
1989
Saxena, S.K.Saxena, S.K.Oxidation state of the mantleGeochimica et Cosmochimica Acta, Vol. 53, No. 1, Jan. pp. 89-95GlobalMantle, Geochemistry
DS1992-1335
1992
Saxena, S.K.Saxena, S.K.Thermodynamic data: systematics and estimationSpringer-Verlag, 344p. approx. $ 100.00 United StatesGlobalThermodynamic data, Book-ad
DS1993-1384
1993
Saxena, S.K.Saxena, S.K., Chatterjee, N., Fei, Y., Shen, G.Thermodynamic dat a on oxides and silicatesSpringer Verlag Publishing, 428p. ISBN 0-387-56898-0 approx. $ 100.00GlobalGeochemistry, Experimental petrology
DS1994-1533
1994
Saxena, S.K.Saxena, S.K., Shen, G., Lazor, P.Temperatures in earth's core based on melting and phase transformation experiments on iron.Science, Vol. 264, April 15, pp. 405-407.MantleCore, Temperature -iron melt
DS1996-1255
1996
Saxena, S.K.Saxena, S.K.Earth mineralogical model: Gibbs free energy minimization computation In the system Mgo FeO SiO2Geochimica et Cosmochimica Acta, Vol. 60, No. 13, pp. 2379-95.MantleGeochemistry - core mantle pressure
DS1996-1256
1996
Saxena, S.K.Saxena, S.K., Dubrovinsky, L.S., Hu, J.Stability of perovskite in the earth's mantleScience, Vol. 274, No. 5291, Nov. 22, pp. 1357-9.MantlePerovskite
DS1998-0367
1998
Saxena, S.K.Dubrovinsky, L., Saxena, S.K., Johansson, B.Theoretical study of the stability of MgSiO3 perovskite in the deepmantle.Geophs. Res. Lett., Vol. 25, No. 23, Dec. 1, pp. 4253-56.MantlePerovskite
DS1998-1288
1998
Saxena, S.K.Saxena, S.K., Dubrovinsky, L.S, Lazor, P.Mineralogy of the core and lower mantleIma 17th. Abstract Vol., p. A 42, abstractMantleMineralogy
DS2000-0861
2000
Saxena, S.K.Saxena, S.K., Lazor, P., Dubrovinsky, L.S.A model of Earth's deep interior based on mineralogical dataMin. Petrol., Vol. 69, No. 1-2, pp. 1-10.MantleMineralogy, Model - mineralogy
DS200912-0241
2009
Saxena, S.K.Ganguly, J., Freed, A.M., Saxena, S.K.Density profiles of oceanic slabs and surrounding mantle: integrated thermodynamic and thermal modeling, and implications for the fate of slabs at the 660 kmPhysics of the Earth and Planetary Interiors, Vol. 172, 3-4, pp. 257-267.MantleGeothermometry
DS201610-1840
2016
Saxey, D.Aravanis, T., Chen, J., Fuechsle, M., Grujic, M., Johnston, P., Kok, Y., Magaraggia, R., Mann, A., Mann, L., McIntoshm S., Rheinberger, G., Saxey, D., Smalley, M., van Kann, F., Walker, G., Winterflood, J.VK1 tm - a next generation airborne gravity gradiometer.ASEG-PESA-AIG 2016 25th Geophysical Conference, Abstract 5p.TechnologyGradiometer

Abstract: The minerals exploration industry’s demand for a highly precise airborne gravity gradiometer has driven development of the VK1TM Airborne Gravity Gradiometer, a collaborative effort by Rio Tinto and the University of Western Australia. VK1TM aims to provide gravity gradient data with lower uncertainty and higher spatial resolution than current commercial systems. In the recent years of VK1TM development, there have been significant improvements in hardware, signal processing and data processing which have combined to result in a complete AGG system that is approaching competitive survey-ready status. This paper focuses on recent improvements. Milestone-achieving data from recent lab-based and moving-platform trials will be presented and discussed, along with details of some advanced data processing techniques that are required to make the most use of the data.
DS201804-0731
2018
Saxey, D.Reddy, S., Saxey, D., Rickard, W., Fougerouse, D.Atom probe microscopy and potential applications to diamond research.4th International Diamond School: Diamonds, Geology, Gemology and Exploration Bressanone Italy Jan. 29-Feb. 2nd., pp. 36-37. abstractTechnologydiamond inclusions
DS201512-1964
2015
Saxon, M.Saxon, M., Leijd, M., Forrester, K., Berg, J.Geology, mineralogy, and metallurgical processing of the Norra Karr heavy REE deposit, Sweden.Symposium on critical and strategic materials, British Columbia Geological Survey Paper 2015-3, held Nov. 13-14, pp. 97-108.Europe, SwedenRare earths

Abstract: The Norra Kärr peralkaline complex is about 300 km southwest of Stockholm in southern Sweden (Fig. 1). As the only heavy REE deposit in the European Union, Norra Kärr is signifi cant for the security of future REE, zirconium (Zr) and hafnium (Hf) supply (European Commission’s European Rare Earths Competency Network; ERECON, 2015). The project is well serviced by power and other infrastructure that will allow year-round mining and processing. A four-lane highway links Scandinavia to mainland Europe and passes with 1km of Norra Kärr. The skill-rich cities of Linköping and Jönköping, lie within daily commuting distances from Norra Kärr. A rail line that passes within 30 km of the site may be used to transport feed stocks and products. If Norra Kärr is developed, European REE users will no longer require substantial material stockpiles to deal with market uncertainties.
DS200812-0765
2008
Saydam, S.Morkel, J., Saydam, S.The influence of potassium on the weathering properties of kimberlite and the information provided by different testing methods.International Journal of Rock Mechanics and Mining Services, Vol. 45, 7, pp. 1187-1194.TechnologyMining
DS201012-0667
2010
Saygin, E.Saygin, E., Kennett, B.L.N.Ambient seismic noise tomography of Australian continent.Tectonophysics, Vol.481, 1-4, pp. 116-125.AustraliaGeophysics - seismics
DS201212-0624
2012
Saygin, E.Saygin, E., Kennett, B.L.N.Crustal structure of Australia from ambient seismic noise tomography.Journal of Geophysical Research, Vol. 117, B1, B01304AustraliaTomography
DS202007-1129
2020
Saygin, E.Chen, Y., Gu, Y/.J., Heaman, L.M., Wu, L., Saygin, E., Hung, S-H.Reconciling seismic structures and Late Cretaceous kimberlite magmatism in northern Alberta, Canada.Geology, Vol. 48, in press available, 5 p. pdfCanada, Albertadeposit - Birch Mountain, Mountain Lake

Abstract: The Late Cretaceous kimberlites in northern Alberta, Canada, intruded into the Paleoproterozoic crust and represent a nonconventional setting for the discovery of diamonds. Here, we examined the origin of kimberlite magmatism using a multidisciplinary approach. A new teleseismic survey reveals a low-velocity (-1%) corridor that connects two deep-rooted (>200 km) quasi-cylindrical anomalies underneath the Birch Mountains and Mountain Lake kimberlite fields. The radiometric data, including a new U-Pb perovskite age of 90.3 ± 2.6 Ma for the Mountain Lake intrusion, indicate a northeast-trending age progression in kimberlite magmatism, consistent with the (local) plate motion rate of North America constrained by global plate reconstructions. Taken together, these observations favor a deep stationary (relative to the lower mantle) source region for kimberlitic melt generation. Two competing models, mantle plume and slab subduction, can satisfy kinematic constraints and explain the exhumation of ultradeep diamonds. The plume hypothesis is less favorable due to the apparent age discrepancy between the oldest kimberlites (ca. 90 Ma) and the plume event (ca. 110 Ma). Alternatively, magma generation may have been facilitated by decompression of hydrous phases (e.g., wadsleyite and ringwoodite) within the mantle transition zone in response to thermal perturbations by a cold slab. The three-dimensional lithospheric structures largely controlled melt migration and intrusion processes during the Late Cretaceous kimberlite magmatism in northern Alberta.
DS201906-1345
2019
Saylor, J.E.Saylor, J.E., Finzel, E., Jadamec, M.Linking observations and modeling of flat-slab subduction. EOS.100, doi.org/10.1029/ 2019/EO122245United States, Montanasubduction
DS201412-0774
2014
Saywell, T.Saywell, T.Gahcho Kue takes shape.. Diamonds in Canada Magazine, Northern Miner, May pp. 12-14.Canada, Northwest TerritoriesDeposit - Gahcho Kue
DS201606-1113
2016
Saywell, T.Saywell, T.Stornoway adds three years to mine life at Renard.Northern Miner Diamonds in Canada, May pp. 18-19.Canada, QuebecDeposit - Renard
DS201112-0888
2011
Saz de Galdeano, C.Ruiz Cruz, M.D., Saz de Galdeano, C., Garrido, C.Electron back scatter diffraction based identification and quantification of diamonds from the RIF gneisses ( Spain and Morocco): economic implications.Economic Geology, Vol. 06, pp. 1241-1249.Europe, Spain, Africa, MoroccoBeni-Bousera, Cabo Negro, Ceuta
DS201112-0360
2011
Sazonov, A.Gertner, I., Tishin, P., Vrublevskii, V., Sazonov, A., Zvyagina, E., Kolmakov, Y.Neoproterozoic alkaline igneous rocks, carbonatites and gold deposits of the Yenisei Ridge, central Siberia: evidence of mantle plume activity and late collision...Resource Geology, Vol. 61, 4, pp. 316-343.Russia, SiberiaTectonics - carbonatites
DS2001-0625
2001
Sazonov, K.Korhonen, J.V., Zhdanova, L., Chepik, A., Zuikova, J., Sazonov, K., Saavuori, H.Magnetic anomaly map of central FIn land - KareliaGeological Society of Finland [email protected], 1: 1 million scale approx. 15.00FinlandBlank
DS200412-1041
2001
Sazonov, K.Korhonen, J.V., Zhdanova, L., Chepik, A., Zuikova, J., Sazonov, K., Saavuori, H.Magnetic anomaly map of central FIn land - Karelia.Geological Society of Finland publication_sales @gtk.fi, 1: 1 million scale approx. 15.00Europe, FinlandMap - geophysics, magnetics
DS1997-0623
1997
Sazonov, V.N.Koroteev, V.A., De Boorder, H., Sazonov, V.N.Geodynamic setting of the mineral deposits of the UralsTectonophysics, Vol. 276, No. 1-4, July 30, pp. 291-300GlobalGeodynamics, tectonics, Deposits
DS200612-0376
2006
SazonovaEppelbaum, L.V., Vaksman, V.L., Kuznetsov, Sazonova, Smirnov, Surkov, Bezlepkin, Katz, Lorotaeva, BelovitDiscovery of microdiamonds and associated minerals in the Makhtesh Ramon Canyon (Negrev Desert) Israel.Doklady Earth Sciences, Vol. 407, 2, Feb-Mar. pp. 202-204.Europe, IsraelMicrodiamonds
DS1996-1257
1996
Sazonova, I.V.Sazonova, I.V.Clinopyroxene from picrite and picrite-basalt dykes of an island arc complex Taguil Trough Ural Superdeep wellInternational Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 361.Russia, UralsPicrite
DS201502-0067
2015
Sazonova, L.Kargin, A., Sazonova, L., Nosova, A., Kovalchuk, E., Minevrina, E.Metasomatic processes in the mantle beneath the Arkangelsk province, Russia: evidence from garnet in mantle peridotite xenoliths, Grib pipe.Economic Geology Research Institute 2015, Vol. 17,, # 748, 1p. AbstractRussia, Kola Peninsula, ArchangelDeposit - Grib
DS201705-0845
2017
Sazonova, L.Lebedeva, N., Kargin, A., Sazonova, L., Nosova, A.Geochemistry of clinopyroxene megacrysts from the Grib kimberlite pipe, Arkhangelsk province, Russia: metasomatic origin and genetic relationship with clinopyroxene phlogopite metasomatic xenoliths.European Geosciences Union General Assembly 2017, Vienna April 23-28, 1p. 220 AbstractRussia, Archangel, Kola PeninsulaDeposit - Grib

Abstract: Kimberlite is a composite rock that contains juvenile magmatic material and xenoliths of crustal and mantle rocks, including metasomatically reworked rocks and megacrysts. In spite of nearly 40-50 years of continuous study of kimberlites and SCLM, some aspects of their origin remain controversial. In particular, it is unclear yet whether the megacrysts are magmatic or metasomatic in origin and how they are related to kimberlite magmas. In this contribution, we compare the major (EMPA) and trace element (SIMS, LA-ICP-MS) compositions of clinopyroxene megacrysts from the Grib kimberlite (Arkhangelsk province, Russia) with clinopyroxenes from metasomatic clinopyroxene-phlogopite xenoliths and garnet peridotite xenoliths. The Grib kimberlite (376±3 Ma, Larionova et al., 2016) is located in the central part of the Arkhangelsk province (the northern part of the East European craton) in the Chernoozero kimberlite field. The geochemical composition of the kimberlites is similar to widespread South Africa group I kimberlites . The Grib kimberlite is well known for hosting a variety of mantle xenoliths, e.g., garnet peridotite, sheared peridotite, eclogite, metasomatised mantle material, as well as megacrysts of clinopyroxene, garnet, olivine, phlogopite, and ilmenite. The clinopyroxene megacrysts occur as rounded or angular grains up to 2 cm in size. They are usually surrounded by ultrafine kimberlite rim. The xenoliths of the metasomatic clinopyroxene-phlogopite rocks reach up to 6 cm in size and have a granoblastic texture. They consist of clinopyroxene (55 vol. %), phlogopite (45 vol. %) and minor calcite, barite, perovskite. Some clinopyroxene grains contain inclusion of relict olivine that is similar in composition to olivine from mantle-derived peridotite xenoliths within the Grib kimberlite (Sazonova et al., 2015). This suggests that these xenoliths could be formed by metasomatic reworking of SCLM peridotites. The megacryst clinopyroxene is compositionally similar to the clinopyroxene found in metasomatic xenoliths and corresponds to diopside. As compared to the typical clinopyroxene megacrysts worldwide, it has higher Mg# (>0.92), Cr# (0.21-0.62) and Ca# values (0.47-0.49) and lower Ti (659-1966 ppm) composition. The clinopyroxenes have (La/Sm)CI values from 0.58 to 1.57, and trace element patterns with deep negative Ti and shallow negative Zr-Hf anomalies. The major and trace-element compositions of these clinopyroxenes are very close to those of clinopyroxenes from garnet peridotite xenoliths in the Grib pipe (Kargin et al., 2016) that could be formed during the ascent and interaction of kimberlite mamas with a surrounding lithospheric mantle after crystallization of garnet and ilmenite megacrysts. Calculations showed that metasomatic agents in equilibrium with clinopyroxene megacrysts are similar in composition to kimberlite, which is consistent with proposed model. To sum up, we suggest that the formation of clinopyroxenes of megacrysts and mantle-derived clinopyroxene-phlogopite metasomatic xenoliths from the Grib kimberlite was related to the late-stage metasomatic reworking of SCLM by kimberlite magmas.
DS202008-1414
2020
Sazonova, L.Lebedeva, N., Nosova, A., Kargin, A., Larionova, Y., Sazonova, L., Tikhomirova, Y.Grib kimberlite peridotitic xenoliths: isotopic evidence of variable source of mantle metasomatism.Goldschmidt 2020, 1p. AbstractRussia, Kola Peninsuladeposit - Grib

Abstract: We present petrography and mineral chemistry for both phlogopite, from mantle-derived xenoliths (garnet peridotite, eclogite and clinopyroxene-phlogopite rocks) and for megacryst, macrocryst and groundmass flakes from the Grib kimberlite in the Arkhangelsk diamond province of Russia to provide new insights into multi-stage metasomatism in the subcratonic lithospheric mantle (SCLM) and the origin of phlogopite in kimberlite. Based on the analysed xenoliths, phlogopite is characterized by several generations. The first generation (Phl1) occurs as coarse, discrete grains within garnet peridotite and eclogite xenoliths and as a rock-forming mineral within clinopyroxene-phlogopite xenoliths. The second phlogopite generation (Phl2) occurs as rims and outer zones that surround the Phl1 grains and as fine flakes within kimberlite-related veinlets filled with carbonate, serpentine, chlorite and spinel. In garnet peridotite xenoliths, phlogopite occurs as overgrowths surrounding garnet porphyroblasts, within which phlogopite is associated with Cr-spinel and minor carbonate. In eclogite xenoliths, phlogopite occasionally associates with carbonate bearing veinlet networks. Phlogopite, from the kimberlite, occurs as megacrysts, macrocrysts, microcrysts and fine flakes in the groundmass and matrix of kimberlitic pyroclasts. Most phlogopite grains within the kimberlite are characterised by signs of deformation and form partly fragmented grains, which indicates that they are the disintegrated fragments of previously larger grains. Phl1, within the garnet peridotite and clinopyroxene-phlogopite xenoliths, is characterised by low Ti and Cr contents (TiO2 < 1 wt.%, Cr2O3 < 1 wt.% and Mg# = 100 × Mg/(Mg + Fe) > 92) typical of primary peridotite phlogopite in mantle peridotite xenoliths from global kimberlite occurrences. They formed during SCLM metasomatism that led to a transformation from garnet peridotite to clinopyroxene-phlogopite rocks and the crystallisation of phlogopite and high-Cr clinopyroxene megacrysts before the generation of host-kimberlite magmas. One of the possible processes to generate low-Ti-Cr phlogopite is via the replacement of garnet during its interaction with a metasomatic agent enriched in K and H2O. Rb-Sr isotopic data indicates that the metasomatic agent had a contribution of more radiogenic source than the host-kimberlite magma. Compared with peridotite xenoliths, eclogite xenoliths feature low-Ti phlogopites that are depleted in Cr2O3 despite a wider range of TiO2 concentrations. The presence of phlogopite in eclogite xenoliths indicates that metasomatic processes affected peridotite as well as eclogite within the SCLM beneath the Grib kimberlite. Phl2 has high Ti and Cr concentrations (TiO2 > 2 wt.%, Cr2O3 > 1 wt.% and Mg# = 100 × Mg/(Mg + Fe) < 92) and compositionally overlaps with phlogopite from polymict breccia xenoliths that occur in global kimberlite formations. These phlogopites are the product of kimberlitic magma and mantle rock interaction at mantle depths where Phl2 overgrew Phl1 grains or crystallized directly from stalled batches of kimberlitic magmas. Megacrysts, most macrocrysts and microcrysts are disintegrated phlogopite fragments from metasomatised peridotite and eclogite xenoliths. Fine phlogopite flakes within kimberlite groundmass represent mixing of high-Ti-Cr phlogopite antecrysts and high-Ti and low-Cr kimberlitic phlogopite with high Al and Ba contents that may have formed individual grains or overgrown antecrysts. Based on the results of this study, we propose a schematic model of SCLM metasomatism involving phlogopite crystallization, megacryst formation, and genesis of kimberlite magmas as recorded by the Grib pipe.
DS202201-0020
2021
Sazonova, L.Kargin, A., Bussweiler, Y., Nosova, A., Sazonova, L., Berndt, J., Klemme, S.Titanium-rich metasomatism in the lithospheric mantle beneath the Arkangelsk diamond province, Russia: insights from ilemenite-bearing xenoliths with HP-HT reaction experiments.Contributions to Mineralogy and Petrology, Vol. 176, 12, Russia, Arlangelskdeposit - Grib

Abstract: To provide new insights into the interaction of ultramafic alkaline melts with the subcontinental lithospheric mantle, we present results of a petrographical-mineralogical study of ilmenite-bearing mantle xenoliths from the Grib kimberlite, Archangelsk, Russia along with results from reaction experiments between harzburgite and Fe-Ti bearing carbonate-silicate melts similar to aillikite. The compositions of orthopyroxene, ilmenite and garnet from our mantle xenoliths are similar to compositions of minerals of the low-Cr megacryst suite from different kimberlite occurrences worldwide including the Grib kimberlite as well as minerals from sheared lherzolite xenoliths captured by the Grib kimberlite. This suggests that ilmenite-bearing xenoliths, megacrysts, and sheared lherzolite xenoliths could have a common origin and/or formed under similar conditions. The reaction experiments were performed at 4 GPa and 1200 °C with varying proportions of aillikite (0, 10, and 50 wt%) that reacted with harzburgite. The experimental runs with 10% and 50% aillikite resulted in two layers within the capsule, with an ilmenite-bearing reaction zone at the contact between aillikite and harzburgite, and an ilmenite-free zone characterized by higher garnet and clinopyroxene abundances. An increase of aillikite melt is directly correlated with increasing TiO2 and decreasing Cr2O3 contents and Mg# values in the mineral phases, most significantly for pyroxenes. Overall, the experiments produce a chemical gradation of minerals from Cr-rich (Fe-Ti-poor) to Cr-poor (Fe-Ti-rich) which is strikingly similar to the chemical gradation observed in minerals from natural mantle-derived xenoliths from kimberlites. In summary, comparison of our experimental data with natural samples indicates possible links between the generation of megacrysts and Ti-rich metasomatism of the lithospheric mantle by ultramafic alkaline (aillikite-related) melts and their possible evolution towards kimberlites. Our results illustrate the importance of melt-rock ratios in generating the mineralogical and chemical diversity in mantle xenolith suites.
DS1985-0186
1985
Sazonova, L.V.Feldman, V.I., Sazonova, L.V., Nozova, A.A.The Structure and Petrography of Impactites of the Puchezh-katunki Astrobleme.International Geology Review, Vol. 27, No. 1, PP. 68-77.RussiaAstrobleme
DS201507-0333
2015
Sazonova, L.V.Sazonova, L.V., Nosova, A.A., Kargin, A.V., Borisovskiy, S.E., Tretyachenko, V.V., Abazova, Z.M., Griban, Yu.G.Olivine from the Pionerskaya and V. Grib kimberlite pipes, Arkangelsk diamond province, Russia: types, composition, and origin.Petrology, Vol. 23, 3, pp. 227-258.RussiaDeposit - Grib
DS201609-1724
2016
Sazonova, L.V.Kargin, A.V., Sazonova, L.V., Nosova, A.A., Tretyachenko, V.V.Composition of garnet and clinopyroxene in peridotite xenoliths from the Grib kimberlite pipe, Arkhangelsk diamond province, Russia: evidence for mantle metasomatism associated with kimberlite melts.Lithos, Vol. 262, pp. 442-455.RussiaDeposit - Grib

Abstract: Here we present major and trace element data for garnet and clinopyroxene from mantle-derived peridotite xenoliths of the Grib kimberlite, the Arkhangelsk diamond province, Russia, and provide new insights into the metasomatic processes that occur within the subcontinental lithospheric mantle (SCLM) during the kimberlite generation and ascent. The mantle xenoliths examined in this study are both coarse and sheared garnet peridotites and consist of olivine, orthopyroxene, clinopyroxene, garnet with minor ilmenite, magnetite, and Cr-spinel. Based on garnet and clinopyroxene composition, two groups of peridotite are recognized. One group contains high-Ti, light rare earth elements (LREE) enriched garnets and low-Mg# clinopyroxenes with low (La/Sm)n (C1 chondrite-normalized) values. This mineral assemblage was in equilibrium with a high-temperature carbonate-silicate metasomatic agent, presumably, a protokimberlite melt. Pressure-temperature (P-T) estimates (T = 1220 °C and P = 70 kbar) suggest that this metasomatic event occurred at the base of the SCLM. Another group contains low-Ti garnet with normal to sinusoidal rare earth elements (REE) distribution patterns and high-Mg# clinopyroxenes with wide range of (La/Sm)n values. The geochemical equilibrium between garnet and clinopyroxene coupled with their REE composition indicates that peridotite mantle experienced metasomatic transformation by injection of a low-Ti (after crystallizations of the ilmenite megacrysts) kimberlite melt that subsequently percolated through a refractory mantle column. Peridotites of this group show a wide range of P-T estimates (T = 730-1070 °C and P = 22-44 kbar). It is suggested that evolution of a kimberlite magma from REE-enriched carbonate-bearing to carbonate-rich ultramafic silicate compositions with lower REE occurs during the ascent and interaction with a surrounding lithospheric mantle, and this process leads to metasomatic modification of the SCLM with formation of both high and low-Ti garnets and clinopyroxene widely varying in Mg# and (La/Sm)n values.
DS201612-2311
2016
Sazonova, L.V.Kargin, A.V., Sazonova, L.V., Nosova, A.A., Pervov, V.A., Minevrina, E.V., Khvostikov, V.A., Burmii, Z.P.Sheared peridotite xenolith from the V. Grib kimberlite pipe, Arkangelsk diamond province, Russia: texture, composition and origin.Geoscience Frontiers, in press availableRussia, Archangel, Kola PeninsulaDeposit - Grib
DS201612-2315
2016
Sazonova, L.V.Larionova, Yu.O., Sazonova, L.V., Lebedeva, N.M., Nosova, A.A., Tretyachenko, V.V., Travin, A.V., Kargin, A.V., Yudin, D.S.Kimberlite age in the Arkhangelsk province, Russia: isotopic geochronologic Rb-Sr and 40Ar/39Ar and mineralogical dat a on phlogopite.Petrology, Vol. 24, 6, pp. 562-593.Russia, Archangel, Kola PeninsulaDeposit - Ermakovskaya-7, Grib, Karpinski

Abstract: The paper reports detailed data on phlogopite from kimberlite of three facies types in the Arkhangelsk Diamondiferous Province (ADP): (i) massive magmatic kimberlite (Ermakovskaya-7 Pipe), (ii) transitional type between massive volcaniclastic and magmatic kimberlite (Grib Pipe), and (iii) volcanic kimberlite (Karpinskii-1 and Karpinskii-2 pipes). Kimberlite from the Ermakovskaya-7 Pipe contains only groundmass phlogopite. Kimberlite from the Grib Pipe contains a number of phlogopite populations: megacrysts, macrocrysts, matrix phlogopite, and this mineral in xenoliths. Phlogopite macrocrysts and matrix phlogopite define a single compositional trend reflecting the evolution of the kimberlite melt. The composition points of phlogopite from the xenoliths lie on a single crystallization trend, i.e., the mineral also crystallized from kimberlite melt, which likely actively metasomatized the host rocks from which the xenoliths were captured. Phlogopite from volcaniclastic kimberlite from the Karpinskii-1 and Karpinskii-2 pipes does not show either any clearly distinct petrographic setting or compositional differentiation. The kimberlite was dated by the Rb-Sr technique on phlogopite and additionally by the 40Ar/39Ar method. Because it is highly probable that phlogopite from all pipes crystallized from kimberlite melt, the crystallization age of the kimberlite can be defined as 376 ± 3 Ma for the Grib Pipe, 380 ± 2 Ma for the Karpinskii-1 pipe, 375 ± 2 Ma for the Karpinskii-2 Pipe, and 377 ± 0.4 Ma for the Ermakovskaya-7 Pipe. The age of the pipes coincides within the error and suggests that the melts of the pipes were emplaced almost simultaneously. Our geochronologic data on kimberlite emplacement in ADP lie within the range of 380 ± 2 to 375 ± Ma and coincide with most age values for Devonian alkaline-ultramafic complexes in the Kola Province: 379 ± 5 Ma; Arzamastsev and Wu, 2014). These data indicate that the kimberlite was formed during the early evolution of the Kola Province, when alkaline-ultramafic complexes (including those with carbonatite) were emplaced.
DS201701-0018
2016
Sazonova, L.V.Kargin, A.V., Nosova, A.A., Postnikov, A.V., Chugaev, A.V., Postnikova, O.V., Popova, L.P., Poshibaev, V.V., Sazonova, L.V., Dokuchaev, A.Ya., Smirnova, M.D.Devonian ultramafic lamprophyre in the Irkineeva Chadobets trough in the southwest of the Siberian platform: age, composition, and implications for diamond potential prediction.Geology of Ore Deposits, Vol. 58, 5, pp. 383-403.RussiaLamprophyre - aillikite

Abstract: The results of geochronological, mineralogical, petrographical, and geochemical study of the Ilbokich ultramafic lamprophyre are reported. The specific features in the mineral and chemical compositions of the studied ultramafic lamprophyre indicate that it can be regarded as a variety similar to aillikite, while other differences dominated by K-feldspar can be referred to damtjernite. According to Rb-Sr analysis, ultramafic lamprophyre dikes intruded at the turn of the Early and Middle Devonian, about 392 Ma ago. This directly proves the existence of Early Paleozoic alkali-ultramafic magmatism in the northern part of the southwest Siberian Platform. A finding of Devonian alkali-ultramafic lamprophyre is of dual predictive importance. On the one hand, it is indicative of the low probability of finding large diamond-bearing deposits in close association with aillikite. On the other hand, it can be indicative of a possible large Devonian diamond province in the studied territory, where diamondiferous kimberlite is structurally separated from aillikite.
DS201705-0863
2017
Sazonova, L.V.Nosova, A.A., Dubinina, E.O., Sazonova, L.V., Vargin, A.V., lebedeva, N.M., Khvostikov, V.A., Burmii, Zh.P., Kondrashov, I.A., Tretyachenko, V.V.Geochemistry and oxygen isotopic composition of olivine in kimberlites from the Arkhangelsk Province: contribution of mantle metasomatism.Petrology, Vol. 25, 2, pp. 150-180.Russia, Archangel, Kola PeninsulaDeposit - Grib, Pionerskaya

Abstract: The paper presents data on the composition of olivine macrocrysts from two Devonian kimberlite pipes in the Arkhangelsk diamond province: the Grib pipe (whose kimberlite belongs to type I) and Pionerskaya pipe (whose kimberlite is of type II, i.e., orangeite). The dominant olivine macrocrysts in kimberlites from the two pipes significantly differ in geochemical and isotopic parameters. Olivine macrocrysts in kimberlite from the Grib pipe are dominated by magnesian (Mg# = 0.92-0.93), Ti-poor (Ti < 70 ppm) olivine possessing low Ti/Na (0.05-0.23), Zr/Nb (0.28-0.80), and Zn/Cu (3-20) ratios and low Li concentrations (1.2-2.0 ppm), and the oxygen isotopic composition of this olivine ?18O = 5.64‰ is higher than that of olivine in mantle peridotites (?18O = 5.18 ± 0.28‰). Olivine macrocrysts in kimberlite from the Pionerskaya pipe are dominated by varieties with broadly varying Mg# = 0.90-0.93, high Ti concentrations (100-300 ppm), high ratios Ti/Na (0.90-2.39), Zr/Nb (0.31-1.96), and Zn/Cu (12-56), elevated Li concentrations (1.9-3.4 ppm), and oxygen isotopic composition ?18O = 5.34‰ corresponding to that of olivine in mantle peridotites. The geochemical and isotopic traits of low-Ti olivine macrocrysts from the Grib pipe are interpreted as evidence that the olivine interacted with carbonate-rich melts/fluids. This conclusion is consistent with the geochemical parameters of model melt in equilibrium with the low-Ti olivine that are similar to those of deep carbonatite melts. Our calculations indicate that the variations in the ?18O of the olivine relative the “mantle range” (toward both higher and lower values) can be fairly significant: from 4 to 7‰ depending on the composition of the carbonate fluid. These variations were formed at interaction with carbonate fluid, whose ?18O values do not extend outside the range typical of mantle carbonates. The geochemical parameters of high-Ti olivine macrocrysts from the Grib pipe suggest that their origin was controlled by the silicate (water-silicate) component. This olivine is characterized by a zoned Ti distribution, with the configuration of this distribution between the cores of the crystals and their outer zones showing that the zoning of the cores and outer zones is independent and was produced during two episodes of reaction interaction between the olivine and melt/fluid. The younger episode (when the outer zone was formed) likely involved interaction with kimberlite melt. The transformation of the composition of the cores during the older episode may have been of metasomatic nature, as follows from the fact that the composition varies from grain to grain. The metasomatic episode most likely occurred shortly before the kimberlite melt was emplaced and was related to the partial melting of pyroxenite source material.
DS201707-1344
2016
Sazonova, L.V.Larionova, Y.O., Sazonova, L.V., Lebedeva, N.M., Nosova, A., Tretyachenko, V.V., Travin, A.V., Kargin, A.V., Yudin, D.S.Kimberlite age in the Arkhangelsk province, Russia: isotopic geochronologic Rb-Sr and 40Ar/39Ar and mineralogical dat a on phlogopite.Petrology, Vol. 24, 6, pp. 562-593.Russiageochronology

Abstract: The paper reports detailed data on phlogopite from kimberlite of three facies types in the Arkhangelsk Diamondiferous Province (ADP): (i) massive magmatic kimberlite (Ermakovskaya-7 Pipe), (ii) transitional type between massive volcaniclastic and magmatic kimberlite (Grib Pipe), and (iii) volcanic kimberlite (Karpinskii-1 and Karpinskii-2 pipes). Kimberlite from the Ermakovskaya-7 Pipe contains only groundmass phlogopite. Kimberlite from the Grib Pipe contains a number of phlogopite populations: megacrysts, macrocrysts, matrix phlogopite, and this mineral in xenoliths. Phlogopite macrocrysts and matrix phlogopite define a single compositional trend reflecting the evolution of the kimberlite melt. The composition points of phlogopite from the xenoliths lie on a single crystallization trend, i.e., the mineral also crystallized from kimberlite melt, which likely actively metasomatized the host rocks from which the xenoliths were captured. Phlogopite from volcaniclastic kimberlite from the Karpinskii-1 and Karpinskii-2 pipes does not show either any clearly distinct petrographic setting or compositional differentiation. The kimberlite was dated by the Rb–Sr technique on phlogopite and additionally by the 40Ar/39Ar method. Because it is highly probable that phlogopite from all pipes crystallized from kimberlite melt, the crystallization age of the kimberlite can be defined as 376 ± 3 Ma for the Grib Pipe, 380 ± 2 Ma for the Karpinskii-1 pipe, 375 ± 2 Ma for the Karpinskii-2 Pipe, and 377 ± 0.4 Ma for the Ermakovskaya-7 Pipe. The age of the pipes coincides within the error and suggests that the melts of the pipes were emplaced almost simultaneously. Our geochronologic data on kimberlite emplacement in ADP lie within the range of 380 ± 2 to 375 ± Ma and coincide with most age values for Devonian alkaline–ultramafic complexes in the Kola Province: 379 ± 5 Ma; Arzamastsev and Wu, 2014). These data indicate that the kimberlite was formed during the early evolution of the Kola Province, when alkaline–ultramafic complexes (including those with carbonatite) were emplaced.
DS201707-1353
2017
Sazonova, L.V.Nosova, A., Tretyachenko, V.V., Sazonova, L.V., Kargin, A.V., Lebedeva, N.M., Khovostikov, V.A., Burmii, Zh.P., Kondrorashov, I.A., Tretyachenko, V.V.Geochemistry and oxygen isotopic composition of olivine in kimberlites from the Arkhangelsk province: contribution of mantle metasomatism.Petrology, Vol. 25, 2, pp. 150-180.Russia, Archangel, Kola Peninsuladeposit - Grib, Pionerskaya

Abstract: The paper presents data on the composition of olivine macrocrysts from two Devonian kimberlite pipes in the Arkhangelsk diamond province: the Grib pipe (whose kimberlite belongs to type I) and Pionerskaya pipe (whose kimberlite is of type II, i.e., orangeite). The dominant olivine macrocrysts in kimberlites from the two pipes significantly differ in geochemical and isotopic parameters. Olivine macrocrysts in kimberlite from the Grib pipe are dominated by magnesian (Mg# = 0.92–0.93), Ti-poor (Ti < 70 ppm) olivine possessing low Ti/Na (0.05–0.23), Zr/Nb (0.28–0.80), and Zn/Cu (3–20) ratios and low Li concentrations (1.2–2.0 ppm), and the oxygen isotopic composition of this olivine ?18O = 5.64‰ is higher than that of olivine in mantle peridotites (?18O = 5.18 ± 0.28‰). Olivine macrocrysts in kimberlite from the Pionerskaya pipe are dominated by varieties with broadly varying Mg# = 0.90–0.93, high Ti concentrations (100–300 ppm), high ratios Ti/Na (0.90–2.39), Zr/Nb (0.31–1.96), and Zn/Cu (12–56), elevated Li concentrations (1.9–3.4 ppm), and oxygen isotopic composition ?18O = 5.34‰ corresponding to that of olivine in mantle peridotites. The geochemical and isotopic traits of low-Ti olivine macrocrysts from the Grib pipe are interpreted as evidence that the olivine interacted with carbonate-rich melts/fluids. This conclusion is consistent with the geochemical parameters of model melt in equilibrium with the low-Ti olivine that are similar to those of deep carbonatite melts. Our calculations indicate that the variations in the ?18O of the olivine relative the “mantle range” (toward both higher and lower values) can be fairly significant: from 4 to 7‰ depending on the composition of the carbonate fluid. These variations were formed at interaction with carbonate fluid, whose ?18O values do not extend outside the range typical of mantle carbonates. The geochemical parameters of high-Ti olivine macrocrysts from the Grib pipe suggest that their origin was controlled by the silicate (water–silicate) component. This olivine is characterized by a zoned Ti distribution, with the configuration of this distribution between the cores of the crystals and their outer zones showing that the zoning of the cores and outer zones is independent and was produced during two episodes of reaction interaction between the olivine and melt/fluid. The younger episode (when the outer zone was formed) likely involved interaction with kimberlite melt. The transformation of the composition of the cores during the older episode may have been of metasomatic nature, as follows from the fact that the composition varies from grain to grain. The metasomatic episode most likely occurred shortly before the kimberlite melt was emplaced and was related to the partial melting of pyroxenite source material.
DS201709-2012
2017
Sazonova, L.V.Kargin, A.V., Sazonova, L.V., Nosova, A.A., Lebedeva, N.M.The mantle metasomatism associated with kimberlite magmatism, the Grib kimberlite pipe, Arkhangelsk diamond province, Russia.Goldschmidt Conference, abstract 1p.Russia, Archangeldeposit - Grib

Abstract: Here we present major (EMPA) and trace element (SIMS, LA-ICP-MS) data for garnet and clinopyroxene from mantlederived xenoliths of coarse and sheared garnet peridotite [1, 2] and clinopyroxene-phlogopite metasomatic rocks from the Grib kimberlite, the Arkhangelsk diamond province, Russia, and provide new insights into the metasomatic processes that occur within the subcontinental lithospheric mantle (SCLM) during the kimberlite melts generation and ascent. The obtained data allowed us to reconstruct the following sequence of metasomatic events associated with the generation of the Grib kimberlite: 1. Ascent of high-temperature asthenospheric or mantle plume material resulted in a partial melting of a carbonated peridotite and led to the generation of high-temperature REEenriched proto-kimberlite melts containing significant amounts of carbonate, Fe-Ti and K-H2O. These protokimberlite melts started to interact with the surrounding mantle rocks during its evolution and ascent, and caused metasomatic modification of both coarse and sheared peridotites at the base of SCLM (T and P estimates are 1220°C and 70 kbar). 2. Further evolution of proto-kimberlite melts during the ascent and the interaction with the surrounding mantle (e.g. mantle-rock assimilation and/or percolative fractional crystallization) led to changes in the kimberlite composition from REE-enriched carbonate-dominated to carbonate-rich ultramafic silicate magmas with lower REE contents. 3. During the ascent, carbonate-rich ultramafic silicate kimberlite melts progressively metasomatised sorrounding SCLM from garnet-phlogopite peridotite through garnetphlogopite peridotite to clinopyroxene-phlogopite rocks under T and P estimated as 830°C and 40 kbar. At this stage, the fractionated of Fe-Ti-bearing megacrysts occurred.
DS201711-2522
2017
Sazonova, L.V.Kargin, A.V., Sazonova, L.V., Nosova, A.A., Lebedeva, N.M., Tretyachenko, V.V., Abersteiner, A.Cr-rich clinopyroxene megacrysts from the Grib kimberlite, Arkangelsk province, Russia: relation to clinopyroxene-phlogopite xenoliths and evidence for mantle metasomatism by kimberlite melts.Lithos, in press available, 52p.Russia, Archangeldeposit - Grib

Abstract: To provide new insights into the origin of megacrysts and metasomatism of the subcontinental lithospheric mantle (SCLM), we present a detailed petrographic and geochemical investigation of clinopyroxene-phlogopite xenoliths and clinopyroxene megacrysts from the Grib kimberlite (Arkhangelsk diamond province, Russia). Clinopyroxene megacrysts and clinopyroxene from clinopyroxene-phlogopite xenoliths have similar petrography, major and trace element compositions, and are therefore classified as Cr-rich megacrysts. Geothermobarometry suggests that Cr-rich clinopyroxenes originate from within the SCLM (3.6-4.7 GPa and 764-922 °C). Phlogopite from clinopyroxene-phlogopite xenoliths have low-Ti and -Cr compositions that overlaps with phlogopite megacrysts from the Grib kimberlite. The clinopyroxene-phlogopite rocks within the SCLM are the main source for Cr-rich clinopyroxene and low-Ti phlogopite megacrysts in the Grib kimberlite matrix. Trace element compositions of studied Cr-rich clinopyroxenes have similar geochemical features to clinopyroxenes megacrysts occurrences worldwide and overlap with clinopyroxenes from phlogopite-garnet peridotite xenoliths from the Grib kimberlite. The strong depletion in Ti, Nb, Ta and to a lesser extent in Zr and Hf in clinopyroxene reflects equilibrium with Ti-oxides, such as ilmenite. The clinopyroxene-phlogopite xenoliths could be the final product of metasomatism of garnet peridotites within the SCLM beneath the Grib kimberlite. The calculated equilibrium of clinopyroxene melt compositions suggests that the metasomatic agents were derived from silicate-bearing kimberlite melts. The presence of veinlets infilled with kimberlitic mineral assemblages in clinopyroxene grains suggests that the clinopyroxene-phlogopite rocks experienced intense interactions with kimberlite melt after their formation, but before their entrainment into the host kimberlite magma. This interaction resulted in the formation of high-Ti and -Cr phlogopite and high-Ti clinopyroxene rims, zones and grains with spongy textures. Finally, we propose the sequence of metasomatic events that occurred in the SCLM and the subsequent formation of the Grib kimberlite.
DS201807-1520
2018
Sazonova, L.V.Nosova, A.A., Sazonova, L.V., Kargin, A.V., Smirnova, M.D., Lapin, A.V., Shcherbakov, V.D.Olivine in ultramafic lamprophyres: chemistry, crystallisation, and melt sources of Siberian pre and post trap aillikites. IlbokichContributions to Mineralogy and Petrology, 10.1007/ s00410-018- 1480-3, 27p.Russia, Siberiakimberlite

Abstract: We studied olivines from the Devonian pre-trap (the Ilbokich occurrence) and the Triassic post-trap (the Chadobets occurrence) carbonate-rich ultramafic lamprophyres (UMLs) in the southwestern portion of the Siberian craton. On the basis of detailed investigations of major, minor, and trace-element distributions, we have reconstructed the main processes that control the origins of these olivines. These include fractional crystallisation from melt, assimilation, and fractional crystallisation processes with orthopyroxene assimilation, melt-reaction diffusive re-equilibration, alkali enrichment, and CO2 degassing of the melt. Furthermore, we inferred the composition of the sources of the primary UML melt and their possible correlations with proto-kimberlitic melts, as well as the influence of the Triassic Siberian plume on the composition of the lithospheric mantle. The main differences between olivines from the Ilbokich and the Chadobets aillikites were that the olivines from the former had more magnesium-rich cores (Mg# = 89.2 ± 0.2), had Mg- and Cr-rich transition zones (Mg# = 89.7 ± 0.2 and 300-500 ppm Cr), had lower Ni (up to 3100 ppm) and Li (1.4-1.5 ppm), and had higher B (0.8-2.6 ppm) contents, all at higher Fo values (90-86), relative to the olivines from the latter (Mg# = 88-75; 200-300 ppm Cr; up to 3400 ppm Ni; 1.4-2.4 ppm Li; 0.4-2.2 ppm B). The Siberian aillikite sources contained a significant amount of metasomatic material. Phlogopite-rich MARID-type veins provided the likely metasomatic component in the pre-trap Devonian Ilbokich aillikite source, whereas the Triassic Chadobets aillikitic post-trap melts were derived from a source with a significant carbonate component. A comparison of UML olivines with olivines from the pre-trap and post-trap Siberian kimberlites shows a striking similarity. This suggests that the carbonate component in the aillikitic source could have been produced by evolved kimberlite melts. The differences in the lithospheric metasomatic component that contributed to pre-trap and post-trap aillikitic melts can be interpreted as reflections of the thermal impact of the Siberian Traps, which reduced phlogopite-bearing metasomes within the southwestern Siberian sub-continental lithospheric mantle.
DS202005-0746
2020
Sazonova, L.V.Lebedeva, N., Nosova, A.A., Kargin, A., Sazonova, L.V.Multi-stage evolution of kimberlite melt as inferred from inclusions in garnet megacrysts in the Grib kimberlite ( Arkangelsk region, Russia.Mineralogy and Petrology, doi: 10.1007/s00710- 020-00704-0 in press 16p. PdfRussia, Arkangeldeposit - Grib

Abstract: To provide new insights into the origin of garnet megacrysts and evolution of kimberlite melts, we studied in detail the polymineralic and monomineralic inclusions and their host garnets from the Grib kimberlite (Arkhangelsk diamond province, Russia). Low-Cr and high-Cr garnet megacrysts and eclogitic garnets contain abundant polymineralic and rare monomineralic inclusions. Monomineralic inclusions presented by clinopyroxene, ilmenite, olivine replaced by serpentine, were found exclusively within the low-Cr megacrysts. The composition of clinopyroxene exhibits geochemical equilibrium with the host garnet, indicating its primary origin during the formation of the megacryst assemblage. The low-Cr garnet-clinopyroxene mineral assemblage formed as a result of high-temperature, melt-associated mantle metasomatism by failed kimberlite within the lithospheric mantle (T = 1150 °C and P = 5.5 GPa). Polymineralic inclusions are characterised by a silicate or silicate-sulphate matrix. The central part of the silicate inclusions is filled by serpentine and contains ilmenite, spinel, perovskite, calcite and apatite. At the contact with host garnets, phlogopite, spinel and amphibole occur as reaction minerals. Composition of spinel and other minerals within inclusions with silicate matrix suggests that kimberlite melt was trapped at mantle pressures. Inclusions with silicate matrix were found in all garnets. The matrix of silicate-sulphate inclusions consists of silicate cryptocrystalline phases and sulphate minerals (celestine-barite) and contains calcite grains. The inclusions are distributed in some low-Cr garnet megacrysts and eclogitic garnet. The silicate-sulphate inclusions were crystallised from the late-stage kimberlite melt. Diverse reaction textures are evidences of disequilibrium between the host crystals and polymineralic inclusions and indicate that garnet and the hosted inclusions reacted with the ascending kimberlite melt. The silicate-sulphate inclusions with a thin rim of epidote within eclogitic garnets indicate that a kimberlite melt invaded the garnet and induced partial melting. The studied inclusions allow us to propose three stages of the Grib kimberlite evolution: 1) generation of garnet megacrysts and primary inclusions due to melt metasomatism, 2) reaction of the high-Ti kimberlite melt with garnet megacrysts (including their dissolution) and 3) alteration of the inclusions in garnet after kimberlite ascent.
DS202005-0754
2020
Sazonova, L.V.Nosova, A.A., Kargin, A.V., Sazonova, L.V., Dubinina, E.O., Chugaev, A.V., Lebedeva, N.M., Yudin, D.S., Larionova, Y.O., Abersteiner, A., Gareev, B.I., Batalin, G.A.Sr-Nd-Pb isotopic systematic and geochronology of ultramafic alkaline magmatism of the southwestern margin of the Siberian craton: metasomatism of the sub-continental lithospheric mantle related to subduction and plume events.Lithos, Vol. 364-365, 21p. PdfRussia, Siberiadeposit - Ilbokich, Chadobets

Abstract: To provide new insights into the origin and evolution of ultramafic lamprophyres (UMLs) and their mantle source, we examined two UML (aillikite and damtjernite) occurrences of different ages in the western portion of the Siberian Craton (Ilbokich and Chadobets). New age, mineral and rock geochemistry, along with Sr-Nd-Pb-C-O isotope data was obtained. Our new 206Pb/238U perovskite age (399 ± 4 Ma) confirms the previously published Early Devonian age of the Ilbokich aillikite. RbSr isochron and 40Ar/39Ar dating yielded a Middle Triassic age (243 ± 3 Ma and 241 ± 1 Ma, respectively) for the Chadobets aillikites, indicating post-Trap emplacement of these rocks. Both UMLs are characterized by incompatible elements, including light rare earth element (LREE) enrichments (La is up to ×200 chondrite concentration), and strong fractionation of REEs ((La/Yb)n: 33-84). Despite the close geochemical affinity of both UMLs, the Nd isotopic compositions of aillikites, as well as the Pb isotopic composition of Chadobets and Ilbokich UMLs, do not overlap and are distinctly different from each other. The initial Sr and Nd isotopic compositions of the Ilbokich UMLs fall in within a narrow 87Sr/86Sr0 range (0.7032-0.7042) and ?Nd(T) (4.03-3.97). Chadobets UMLs have a similar Sr isotopic signature (87Sr/86Sr0: 0.7031-0.7043) and a more depleted Nd isotopic signature (?Nd(T) 4.09-5.08). The initial Pb isotope compositions of the Chadobets UMLs are moderately radiogenic, ranging between 206Pb/204Pb = 18.4-19.0, 208Pb/204Pb = 38.3-38.8, and are characterized by a narrow 207Pb/204Pb ratio between 15.5 and 15.6. The Ilbokich Pb isotope compositions are less variable and range between 206Pb/204Pb = 18.0-18.4, 208Pb/204Pb = 37.8-38.4 and 207Pb/204Pb ratios between 15.5 and 15.6. The oxygen isotopic composition of carbonate from both UMLs is characterized by highly variable ?18O values from +12.1 and up to +20.5‰ (SMOW). The isotopic composition of ?13C values range from ?1.3‰ to ?7.1. Based on the minor impact of crustal contamination in both aillikites, it is inferred that their radiogenic isotope composition reflects a mantle source signature. The mantle source of the Chadobets aillikites is likely to include carbonatitic magma as a metasomatic agent. In contrast, phlogopite-rich metasomes within the lithospheric mantle could have contributed more significantly to the Ilbokich aillikites. These metasomes could be formed during the Caledonian orogeny, which did not only affect the southwestern boundary of the Siberian Craton, but also expanded to the craton interior. This study provides additional support for the evolution of the south-western portion of the Siberian SCLM, ranging from mantle containing phlogopite enrichment domains during the Early Devonian to hydrous-phase reduced mantle in the Triassic due to the thermal impact of the Siberian Traps.
DS202006-0943
2020
Sazonova, L.V.Novosa, A.A., Kargin, A.V., Sazonova, L.V., Dubinina, E.O., Chugaev, A.V., Lebedeva, N.M., Yudin, D.S., Larionova, Y.O., Abersteiner, A., Gareev, B.I., Batalin, G.A.Sr-N-Pb isotopic systematic and geochronology of ultramafic alkaline magmatism of the southwestern margin of the Siberian craton: metasomatism of the sub-continental lithospheric mantle related to subduction and plume events.Lithos, Vol. 364-365, 21p. PdfRussiaailikite, damjernite

Abstract: To provide new insights into the origin and evolution of ultramafic lamprophyres (UMLs) and their mantle source, we examined two UML (aillikite and damtjernite) occurrences of different ages in the western portion of the Siberian Craton (Ilbokich and Chadobets). New age, mineral and rock geochemistry, along with Sr-Nd-Pb-C-O isotope data was obtained. Our new 206Pb/238U perovskite age (399 ± 4 Ma) confirms the previously published Early Devonian age of the Ilbokich aillikite. RbSr isochron and 40Ar/39Ar dating yielded a Middle Triassic age (243 ± 3 Ma and 241 ± 1 Ma, respectively) for the Chadobets aillikites, indicating post-Trap emplacement of these rocks. Both UMLs are characterized by incompatible elements, including light rare earth element (LREE) enrichments (La is up to ×200 chondrite concentration), and strong fractionation of REEs ((La/Yb)n: 33-84). Despite the close geochemical affinity of both UMLs, the Nd isotopic compositions of aillikites, as well as the Pb isotopic composition of Chadobets and Ilbokich UMLs, do not overlap and are distinctly different from each other. The initial Sr and Nd isotopic compositions of the Ilbokich UMLs fall in within a narrow 87Sr/86Sr0 range (0.7032-0.7042) and ?Nd(T) (4.03-3.97). Chadobets UMLs have a similar Sr isotopic signature (87Sr/86Sr0: 0.7031-0.7043) and a more depleted Nd isotopic signature (?Nd(T) 4.09-5.08). The initial Pb isotope compositions of the Chadobets UMLs are moderately radiogenic, ranging between 206Pb/204Pb = 18.4-19.0, 208Pb/204Pb = 38.3-38.8, and are characterized by a narrow 207Pb/204Pb ratio between 15.5 and 15.6. The Ilbokich Pb isotope compositions are less variable and range between 206Pb/204Pb = 18.0-18.4, 208Pb/204Pb = 37.8-38.4 and 207Pb/204Pb ratios between 15.5 and 15.6. The oxygen isotopic composition of carbonate from both UMLs is characterized by highly variable ?18O values from +12.1 and up to +20.5‰ (SMOW). The isotopic composition of ?13C values range from ?1.3‰ to ?7.1. Based on the minor impact of crustal contamination in both aillikites, it is inferred that their radiogenic isotope composition reflects a mantle source signature. The mantle source of the Chadobets aillikites is likely to include carbonatitic magma as a metasomatic agent. In contrast, phlogopite-rich metasomes within the lithospheric mantle could have contributed more significantly to the Ilbokich aillikites. These metasomes could be formed during the Caledonian orogeny, which did not only affect the southwestern boundary of the Siberian Craton, but also expanded to the craton interior. This study provides additional support for the evolution of the south-western portion of the Siberian SCLM, ranging from mantle containing phlogopite enrichment domains during the Early Devonian to hydrous-phase reduced mantle in the Triassic due to the thermal impact of the Siberian Traps.
DS202008-1407
2020
Sazonova, L.V.Kargin, A.V., Nosova, A.A., Sazonova, L.V., Peresetskaya, E.V., Golubeva, Yu.Yu., Lebedeva, N.M., Tretyachenko, V.V., Khvostikov, V.A., Burmii, J.P.Ilmenite from the Arkangelsk diamond province, Russia: composition, origin and indicator of diamondiferous kimberlites.Petrology, Vol. 28, 4, pp. 341-369. pdfRussia, Archangelilmenite

Abstract: To provide new insights into the origin and evolution of kimberlitic magmas with different diamond concentrations from the Arkhangelsk diamond province in northwestern Russia, we examined the major-and trace-element compositions of ilmenite from diamondiferous kimberlite of the Grib pipe and diamond barren kimberlites from the Kepino cluster (Stepnaya and TsNIGRI-Arkhangelskaya pipes). Ilmenite from diamond-barren kimberlites shows lower Mg, Ti, Cr, Ni and Cu concentrations with increase in both Fe 3+ and Fe 2+ and Nb, Ta, Zr, Hf, Zn and V concentrations. The main differences between kimberlites with different diamond contents are the Nb and Zr concentrations and their correlation patterns with Mg and Cr concentrations. Ilmenite from the Grib kimberlite has Zr concentrations <110 ppm, whereas ilmenite from the Kepino kimberlites has Zr concentrations >300 ppm. Ilmenite crystallisation within the Grib kimberlite occurred under increasing oxygen fugacity (fO 2), which may reflect assimilation of mantle peridotite by the kimberlitic magmas. Ilmenite from the Kepino kimberlites suggests its crystallisation under constant fO 2 , with the ilmenite composition being controlled by processes of fractional crystallisation of megacrystic minerals. These assumptions were confirmed with assimilation-fractional crystallisation calculations. On the basis of obtained data, we developed a model for the evolution of the kimberlitic magmas for both diamon-diferous and barren kimberlites. The diamond-bearing kimberlitic magmas were generated under intense interaction of kimberlitic magmas with the surrounding lithospheric mantle. It may be that during early modification of the lithospheric mantle by kimberlitic magmas as well as with kimberlitic magmas' local stretching and swift ascent, the capture of the mantle xenoliths was favoured over the crystallisation of phenocrysts. The formation of barren kimberlitic magmas may have occurred when the lithospheric mantle in the vicinity of ascending magmas was already geochemically equilibrated with them. It also is possible that the magma's ascent slowed under conditions of dominantly compressive stresses with crystallisation of olivine and other megacrystic phases.
DS202008-1415
2020
Sazonova, L.V.Lebedeva, N.M., Nosova, A.A., Kargin, A.V., Sazonova, L.V.Multi-stage evolution of kimberlite melt as inferred from inclusions in garnet megacrysts in the Grib kimberlite ( Arkangelsk region, Russia).Mineralogy and Petrology, Vol. 114, 4, pp. 272-288. pdfRussia, Archangeldeposit - Grib

Abstract: To provide new insights into the origin of garnet megacrysts and evolution of kimberlite melts, we studied in detail the polymineralic and monomineralic inclusions and their host garnets from the Grib kimberlite (Arkhangelsk diamond province, Russia). Low-Cr and high-Cr garnet megacrysts and eclogitic garnets contain abundant polymineralic and rare monomineralic inclusions. Monomineralic inclusions presented by clinopyroxene, ilmenite, olivine replaced by serpentine, were found exclusively within the low-Cr megacrysts. The composition of clinopyroxene exhibits geochemical equilibrium with the host garnet, indicating its primary origin during the formation of the megacryst assemblage. The low-Cr garnet–clinopyroxene mineral assemblage formed as a result of high-temperature, melt-associated mantle metasomatism by failed kimberlite within the lithospheric mantle (T?=?1150 °C and P?=?5.5 GPa). Polymineralic inclusions are characterised by a silicate or silicate-sulphate matrix. The central part of the silicate inclusions is filled by serpentine and contains ilmenite, spinel, perovskite, calcite and apatite. At the contact with host garnets, phlogopite, spinel and amphibole occur as reaction minerals. Composition of spinel and other minerals within inclusions with silicate matrix suggests that kimberlite melt was trapped at mantle pressures. Inclusions with silicate matrix were found in all garnets. The matrix of silicate-sulphate inclusions consists of silicate cryptocrystalline phases and sulphate minerals (celestine–barite) and contains calcite grains. The inclusions are distributed in some low-Cr garnet megacrysts and eclogitic garnet. The silicate-sulphate inclusions were crystallised from the late-stage kimberlite melt. Diverse reaction textures are evidences of disequilibrium between the host crystals and polymineralic inclusions and indicate that garnet and the hosted inclusions reacted with the ascending kimberlite melt. The silicate-sulphate inclusions with a thin rim of epidote within eclogitic garnets indicate that a kimberlite melt invaded the garnet and induced partial melting. The studied inclusions allow us to propose three stages of the Grib kimberlite evolution: 1) generation of garnet megacrysts and primary inclusions due to melt metasomatism, 2) reaction of the high-Ti kimberlite melt with garnet megacrysts (including their dissolution) and 3) alteration of the inclusions in garnet after kimberlite ascent.
DS202010-1849
2020
Sazonova, L.V.Kargin, A.V., Nosova, A.A., Sazonova, L.V., Peresetskaya, E.V., Golubeva, Yu.Yu., Lebedeva, N.M., Tretyachenko, V.V., Khvostikov, V.A., Burmii, J.P.Ilmenite from the Arkangelsk diamond province, Russia: composition, origin and indicator of diamondiferous kimberlites.Petrology, Vol. 28, 4, pp. 315-337. pdfRussia, Archangeldeposit - Grib, Kepino cluster

Abstract: To provide new insights into the origin and evolution of kimberlitic magmas with different diamond concentrations from the Arkhangelsk diamond province in north-western Russia, we examined the major- and trace-element compositions of ilmenite from diamondiferous kimberlite of the Grib pipe and diamond-barren kimberlites from the Kepino cluster (Stepnaya and TsNIGRI-Arkhangelskaya pipes). Ilmenite from diamond-barren kimberlites shows lower Mg, Ti, Cr, Ni and Cu concentrations with increase in both Fe3+ and Fe2+ and Nb, Ta, Zr, Hf, Zn and V concentrations. The main differences between kimberlites with different diamond contents are the Nb and Zr concentrations and their correlation patterns with Mg and Cr concentrations. Ilmenite from the Grib kimberlite has Zr concentrations <110 ppm, whereas ilmenite from the Kepino kimberlites has Zr concentrations >300 ppm. Ilmenite crystallisation within the Grib kimberlite occurred under increasing oxygen fugacity (fO2), which may reflect assimilation of mantle peridotite by the kimberlitic magmas. Ilmenite from the Kepino kimberlites suggests its crystallisation under constant fO2, with the ilmenite composition being controlled by processes of fractional crystallisation of megacrystic minerals. These assumptions were confirmed with assimilation-fractional crystallisation calculations. On the basis of obtained data, we developed a model for the evolution of the kimberlitic magmas for both diamondiferous and barren kimberlites. The diamond-bearing kimberlitic magmas were generated under intense interaction of kimberlitic magmas with the surrounding lithospheric mantle. It may be that during early modification of the lithospheric mantle by kimberlitic magmas as well as with kimberlitic magmas’ local stretching and swift ascent, the capture of the mantle xenoliths was favoured over the crystallisation of phenocrysts. The formation of barren kimberlitic magmas may have occurred when the lithospheric mantle in the vicinity of ascending magmas was already geochemically equilibrated with them. It also is possible that the magma’s ascent slowed under conditions of dominantly compressive stresses with crystallisation of olivine and other megacrystic phases.
DS202010-1856
2020
Sazonova, L.V.Lebedeva, N.M., Nosova, A.A., Kargin, A.V., Larionova, Y.O., Sazonova, L.V., Tikhomirova, Y.S.S-Nd-O isotopic evidence of variable sources of mantle metasomatism in the subcratonic lithospheric mantle beneath the Grib kimberlite, northwestern Russia.Lithos, in press available, 54p. PdfRussia, Kola Peninsuladeposit - Grib

Abstract: To provide new insights into the type and extent of mantle metasomatism in the subcratonic lithospheric mantle, we examined the Sr-Nd-O isotopic compositions of orthopyroxene, clinopyroxene, garnet, ilmenite and phlogopite from sheared garnet lherzolite, granular garnet harzburgites and lherzolites and clinopyroxene-phlogopite rocks from the Grib kimberlite in the Arkhangelsk diamond province in northwestern Russia. Clinopyroxene and orthopyroxene from sheared garnet lherzolite initially have a close value of 87Sr/86Sr(t) (~0.7034) and close weak positive ?Nd. Orthopyroxene and clinopyroxene are in oxygen isotope equilibrium with coexisting olivine. Clinopyroxene from a garnet harzburgite has a low 87Sr/86Sr(t) isotope ratio of 0.70266. Clinopyroxene from granular garnet lherzolites has a relatively narrow variation in 87Sr/86Sr(t) (0.70456-0.70582) and considerably larger variations in ?Nd (?4.3???+1.0) isotope ratios. Garnet displays elevated initial 87Sr/86Sr(t) values (0.70540-0.70633). Ilmenite shows a narrow range in 87Sr/86Sr(t) (0.70497-0.70522) coupled with ?Nd values of +0.4 and +3.5. These isotopic data suggest granular garnet lherzolite of mantle metasomatism took place during the interaction of kimberlite melts with SCLM that contained mica-amphibole-rutile-ilmenite-diopside (MARID)-type metasomes. Clinopyroxenes from clinopyroxene-phlogopite (phlogopite wehrlite) xenoliths display a broader range in 87Sr/86Sr(t) (0.70486-0.70813) that is significantly higher than the kimberlite values and a circa-chondritic ?Nd (?0.1 ??+1.3) with a restricted ?18O range (5.11‰-5.33‰). More radiogenic Sr isotopic composition decoupled from Nd isotopes could have been induced by metasomatic melt/fluid related to a subducted material. The isotopic compositions of mantle minerals preserve Sr-Nd isotopic evidence of pre-kimberlite metasomatic events that were probably due to incomplete reequilibration with ultramafic carbonated melt. Based on mineral pairs Rb-Sr isochrons and a clinopyroxene-based Sm-Nd errochron, these mantle metasomatic events correspond to ~550-600?Ma and ~1200?Ma episodes of magmatic-thermal activity.
DS202107-1104
2021
Sazonova, L.V.Kargin, A.V., Nosova, A.A., Sazonova, L.V., Tretyachenko, V.V., Larinova, Y.O., Kovalchuk, E.V.Ultramafic alkaline rocks of Kepino cluster, Arkhangelsk, Russia: different evolution of kimberlite melts in sills and pipes.Minerals MDPI, Vol. 11, 540, 33p. PdfRussia, Arkhangelskdeposit - Kepino

Abstract: To provide new insights into the evolution of kimberlitic magmas, we have undertaken a detailed petrographic and mineralogical investigation of highly evolved carbonate-phlogopite-bearing kimberlites of the Kepino cluster, Arkhangelsk kimberlite province, Russia. The Kepino kimberlites are represented by volcanoclastic breccias and massive macrocrystic units within pipes as well as coherent porphyritic kimberlites within sills. The volcanoclastic units from pipes are similar in petrography and mineral composition to archetypal (Group 1) kimberlite, whereas the sills represent evolved kimberlites that exhibit a wide variation in amounts of carbonate and phlogopite. The late-stage evolution of kimberlitic melts involves increasing oxygen fugacity and fluid-phase evolution (forming carbonate segregations by exsolution, etc.). These processes are accompanied by the transformation of primary Al- and Ti-bearing phlogopite toward tetraferriphlogopite and the transition of spinel compositions from magmatic chromite to magnesian ulvöspinel and titanomagnetite. Similar primary kimberlitic melts emplaced as sills and pipes may be transitional to carbonatite melts in the shallow crust. The kimberlitic pipes are characterised by low carbonate amounts that may reflect the fluid degassing process during an explosive emplacement of the pipes. The Kepino kimberlite age, determined as 397.3 ± 1.2 Ma, indicates two episodes of ultramafic alkaline magmatism in the Arkhangelsk province, the first producing non-economic evolved kimberlites of the Kepino cluster and the second producing economic-grade diamondiferous kimberlites.
DS202108-1301
2021
Sazonova, L.V.Nosova, A.A., Kopylova, M.G., Sazonova, L.V., Vozniak, A.A., Kargin, A.V., Lebedeva, N.M., Volkova, G.D., Peresetskaya, E.V.Petrology of lamprophyre dykes in the Kola alkaline carbonatite province.Lithos, Vol. 398-399. 106277Russia, Kola Peninsulacarbonatite

Abstract: The study reports petrography, bulk major and trace element compositions of lamprophyric Devonian dykes in three areas of the Kola Alkaline Carbonatite Province (N Europe). Dykes in one of these areas, Kandalaksha, are not associated with a massif, while dykes in Kandaguba and Turij Mys occur adjacent (< 5 km) to coeval central multiphase ultramafic alkaline?carbonatitic massifs. Kandalaksha dyke series consists of aillikites - phlogopite carbonatites and monchiquites. Kandaguba dykes range from monchiquites to nephelinites and phonolites; Turij Mys dykes represent alnöites, monchiquites, foidites, turjaites and carbonatites. Some dykes show extreme mineralogical and textural heterogeneity and layering we ascribe to fluid separation and crystal cumulation. Melt evolution of the dykes was modelled with Rhyolite-MELTS and compared with the observed order and products of the crystallization. Our results suggest that the studied rocks were related by fractional crystallization and liquid immiscibility. Primitive melts of aillikites or olivine melanephelinites initially evolved at P = 1.5-0.8 GPa without a SiO2 increase due to abundant clinopyroxene crystallization controlled by the CO2-rich fluid. At 1-1.1 GPa the Turij Mys melts separated immiscible carbonatite melt, which subsequently exsolved late carbonate-rich fluids extremely rich in trace elements. Kandaguba and Turij Mys melts continued to fractionate at lower pressures in the presence of hydrous fluid to the more evolved nephelinite and phonolite melts. The studied dykes highlight the critical role of the parent magma chamber in crystal fractionation and magma diversification. The Kandalaksha dykes may represent a carbonatite - ultramafic lamprophyre association, which fractionated at 45-20 km in narrow dykes on ascent to the surface and could not get more evolved than monchiquite. In contrast, connections of Kandaguba and Turij Mys dykes to their massif magma chambers ensured the sufficient time for fractionation, ascent and a polybaric evolution. This longevity generated more evolved rock types with the higher alkalinity and an immiscible separation of carbonatites.
DS1996-1258
1996
Sburlatti, R.Sburlatti, R.Experts reports in prospectuses - a regulator's viewsAustralian Institute of Mining and Metallurgy (AusIMM) Bulletin, No. 4, June pp. 14-15AustraliaEconomics, Prospectus
DS1996-0411
1996
Scafe, D.W.Edwards, W.A.D., Scafe, D.W.The stratigraphy and occurrence of preglacial gravels in AlbertaCalgary Mining Forum Fifth Held April 11, 12., p. 10. abstractAlbertaGeomorphology, Diamond overview
DS201112-0711
2011
Scaglia, F.Muzio, R., Scaglia, F., Masquelin, H.Petrochemistry of Mesozoic intrusions related to the Parana magmatic province, Uruguay.International Geology Review, In press available,South America, UruguayDike swarms
DS201808-1748
2018
Scaife, A.M.M.Greaves, J.S., Scaife, A.M.M., Frayer, D.T., Green, D.A., Mason, B.S., Smith, A.M.S.Anomalous microwave emission from spinning nanodiamonds around stars.Nature Astronomy, doi.org/10.1038/s41550-018-0495-zGlobalnanodiamonds

Abstract: Several interstellar environments produce 'anomalous microwave emission', with brightness-peaks at tens-of-gigahertz frequencies. The emission's origins are uncertain - rapidly-spinning nano-particles could emit electric-dipole radiation, but polycyclic aromatic hydrocarbons proposed as the carrier are now found not to correlate with Galactic signals. The difficulty is to identify co-spatial sources over long lines of sight. Here we identify anomalous microwave emission in three proto-planetary discs. These are the only known systems that host hydrogenated nano-diamonds, in contrast to very common detection of polycyclic aromatic hydrocarbons. Spectroscopy locates the nano-diamonds close to the host-stars, at physically-constrained temperatures. Developing disc models, we reproduce the emission with diamonds 0.75-1.1 nanometres in radius, holding less than or equal to 1-2 per cent of the carbon budget. The microwave-emission:stellar-luminosity ratios are approximately constant, allowing nano-diamonds to be ubiquitous but emitting below detection thresholds in many star-systems. This can unify the findings with similar-sized diamonds found within solar system meteorites. As nano-diamond spectral absorption is seen in interstellar sightlines, these particles are also a candidate for generating galaxy-scale anomalous microwave emission.
DS2001-0951
2001
Scaillet, B.Prouteau, C., Scaillet, B., Maury, R.Evidence for mantle metasomatism by hydrous silicate melts derived from subducted oceanic crust.Nature, Vol. 410, No. 6825, Mar. 8, pp. 197-9.MantleMetasomatism, Subduction
DS2001-1021
2001
Scaillet, B.Scaillet, B., Prouteau, G.Oceanic slab melting and mantle metasomatismScience Progress, Vol. 84, No. 4, pp. 335-54.MantleMetasomatism
DS200612-0846
2006
Scaillet, B.Macdonald, R., Scaillet, B.The central Kenya peralkaline province: insights into the evolution of peralkaline salic magmas.Lithos, in press availableAfrica, KenyaMagmatism - not specific to alkaline rocks
DS200812-0321
2008
Scaillet, B.Erdmann, S., Scaillet, B., Dungan, M.Zoning in olivine xenocryst in hydrous systems.Goldschmidt Conference 2008, Abstract p.A245.MantleZoning patterns
DS201112-0919
2011
Scaillet, B.Scaillet, B.Experimental constraints on the storage conditions of peralkaline felsic magmas with implications on magmatic fluid compositions and transport of metallic elementsPeralk-Carb 2011, workshop held Tubingen Germany June 16-18, AbstractMelting
DS201605-0895
2016
Scaillet, B.Scaillet, B., Holtz, F., Pichavant, M.Enigmatic relationship between silicic volcanic and plutonic rocks: experimental constraints on the formation of silicic magmas.Elements, Vol. 12, pp. 109-114.TechnologyMagmatism
DS201608-1419
2016
Scalabrin, C.Maia, M., Sichel, S., Briais, A., Brunelli, D., Ligi, M., Ferreira, N., Campos, T., Mougel, B., Brehme, I., Hemond, C., Motoki, A., Moura, D., Scalabrin, C., Pessanha, I., Alves, E., Ayres, A., Oliveira, P.Extreme mantle uplift and exhumation along a transpressive transform fault.Nature Geoscience, Vol. 9, 8, pp. 619-623.MantleRidges

Abstract: Mantle exhumation at slow-spreading ridges is favoured by extensional tectonics through low-angle detachment faults1, 2, 3, 4, and, along transforms, by transtension due to changes in ridge/transform geometry5, 6. Less common, exhumation by compressive stresses has been proposed for the large-offset transforms of the equatorial Atlantic7, 8. Here we show, using high-resolution bathymetry, seismic and gravity data, that the northern transform fault of the St Paul system has been controlled by compressive deformation since ~10?million years ago. The long-lived transpression resulted from ridge overlap due to the propagation of the northern Mid-Atlantic Ridge segment into the transform domain, which induced the migration and segmentation of the transform fault creating restraining stepovers. An anticlockwise change in plate motion at ~11?million years ago5 initially favoured extension in the left-stepping transform, triggering the formation of a transverse ridge, later uplifted through transpression, forming the St Peter and St Paul islets. Enhanced melt supply at the ridge axis due to the nearby Sierra Leone thermo chemical anomaly9 is responsible for the robust response of the northern Mid-Atlantic Ridge segment to the kinematic change. The long-lived process at the origin of the compressive stresses is directly linked to the nature of the underlying mantle and not to a change in the far-field stress regime.
DS1995-1661
1995
Scales, J.A.Scales, J.A.Theory of seismic imagingSpringer, 291p. approx. $ 90.00MantleGeophysics -seismics, Book -ad
DS200712-0941
2006
Scales, M.Scales, M.Ontario's first diamond mine. Victor project readied for 2008 start.Canadian Mining Journal, October pp.27-29.Canada, Ontario, AttawapiskatDeposit - Victor
DS200712-0942
2007
Scales, M.Scales, M.The real value of Victor Diamonds. Economic benefits.Canadian Mining Journal, Jan. p. 16.Canada, Ontario, AttawapiskatNews item - De Beers
DS200912-0670
2009
Scales, M.Scales, M.What a gem! Story about Victor mine.Canadian Mining Journal, Jan. pp. 16-21.Canada, OntarioDeposit - Victor
DS201212-0625
2012
Scales, M.Scales, M.Driven diamonds… Shore Gold set to build first diamond mine in Saskatchewan.Canadian Mining Journal, June/July pp. 20-23.Canada, SaskatchewanDeposit - Star
DS201412-0775
2014
Scales, M.Scales, M.Stornoway tames Renard. Quebec's first diamond mine prepares for 2016 start.Canadian Mining Journal, October pp. 22-27.Canada, QuebecDeposit - Renard
DS200812-1012
2007
Scalie, S.Scalie, S., Philippe, M., Sirakian, D.La mine de Williamson.Revue de gemologie, No. 159, pp. 21-25. in French.Africa, TanzaniaHistory
DS1981-0367
1981
Scalisi, P.Scalisi, P., Cook, D.Classic Mineral Localities of the World. Asia and AustraliaNew York: Van Nostrand., 226P.India, Russia, Australia, AsiaDiamond Occurrences, Diamonds Notable
DS201812-2808
2018
Scalzo, R.Farahbakhsh, E., Chandra, R., Olierook, H.K.H., Scalzo, R., Clark, C., Reddy, S.M., Muller, R.D.Computer vision based framework for extracting geological lineaments from optical remote sensing data.researchgate.com, arXiv:1810.02320v1 17p. Oct 4.Globallineaments

Abstract: The extraction of geological lineaments from digital satellite data is a fundamental application in remote sensing. The location of geological lineaments such as faults and dykes are of interest for a range of applications, particularly because of their association with hydrothermal mineralization. Although a wide range of applications have utilized computer vision techniques, a standard workflow for application of these techniques to mineral exploration is lacking. We present a framework for extracting geological lineaments using computer vision techniques which is a combination of edge detection and line extraction algorithms for extracting geological lineaments using optical remote sensing data. It features ancillary computer vision techniques for reducing data dimensionality, removing noise and enhancing the expression of lineaments. We test the proposed framework on Landsat 8 data of a mineral-rich portion of the Gascoyne Province in Western Australia using different dimension reduction techniques and convolutional filters. To validate the results, the extracted lineaments are compared to our manual photointerpretation and geologically mapped structures by the Geological Survey of Western Australia (GSWA). The results show that the best correlation between our extracted geological lineaments and the GSWA geological lineament map is achieved by applying a minimum noise fraction transformation and a Laplacian filter. Application of a directional filter instead shows a stronger correlation with the output of our manual photointerpretation and known sites of hydrothermal mineralization. Hence, our framework using either filter can be used for mineral prospectivity mapping in other regions where faults are exposed and observable in optical remote sensing data.
DS201905-1028
2018
Scalzo, R.Farahbakhsh, E., Chandra, R., Olierook, H.K.H., Scalzo, R., Clark, C., Reddy, S.M., Muller, R.D.Computer vision based framework for extracting geological lineaments from optical remote sensing data.arXiv.1810,02320vl, researchgate 17p.Australialineaments
DS1998-1161
1998
ScambelluriPhilpott, P., Agrinier, ScambelluriChlorine cycling during subduction of altered oceanic crustMineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1169-70.MantleSubducion, Volatiles
DS1995-1662
1995
Scambelluri, M.Scambelluri, M., Muntener, O., Hermann, J., Piccardo, et al.Subduction of water into mantle: history of an Alpine peridotiteGeology, Vol. 23, No. 5, May pp. 459-462.GlobalSubduction, Peridotite
DS1999-0626
1999
Scambelluri, M.Scambelluri, M., Rampone, E.magnesium metasomatism of oceanic gabbros and its control on Ti clinohumite formation during eclogization.Contributions to Mineralogy and Petrology, Vol. 135, No. 1, pp. 1-17.GlobalMetasomatism, Eclogites
DS2000-0408
2000
Scambelluri, M.Hermann, J., Muntener, O., Scambelluri, M.The importance of serpentinite mylonites for subduction and exhumation of oceanic crust.Tectonophysics, Vol. 327, No. 3-4, Dec.15, pp. 225-38.MantleSubduction
DS2001-1022
2001
Scambelluri, M.Scambelluri, M., Bottazzi, P., Trommsdorf, V., VanucciThe analysis of fluid + mineral inclusions in deeply subducted hydrous mantle: implications for genesis...Plinius, No. 24, p. 193-4 abstractMantleTrace element rich supercritical fluids, Subduction
DS2001-1023
2001
Scambelluri, M.Scambelluri, M., Bottazzi, P., Trommsdorff, VannucciIncompatible element rich fluids released by antigorite breakdown in deeply subducted mantle.Earth and Planetary Science Letters, Vol. 192, No. 3, pp. 457-70.MantleGeochemistry, Subduction
DS2001-1024
2001
Scambelluri, M.Scambelluri, M., Philippot, P.Deep fluids in subduction zonesLithos, Vol. 55, No.1-4, Jan. pp. 213-27.MantleSubduction, eclogite, metamorphism, Fluid inclusions
DS200412-1738
2004
Scambelluri, M.Scambelluri, M., Muntener, O., Ottolini, L., Pettke, T.T., Vanucci, R.The fate of B, Cl and Li in the subducted oceanic mantle and in the antigorite breakdown fluids.Earth and Planetary Science Letters, Vol. 222, 1, pp. 217-234.MantleSubduction, geochemistry
DS200612-0854
2006
Scambelluri, M.Malaspina, N., Hermann, J., Scambelluri, M., Compagnoni, R.Multistage metasomatism in ultrahigh pressure mafic rocks from North Dabie complex (China).Lithos, Vol.90, 1-2, August pp. 19-42.ChinaUHP - metasomatism
DS200612-1231
2006
Scambelluri, M.Scambelluri, M., Hermann, J., Malaspina, N.The deep subduction fluids in high and ultrahigh pressure rocks and their interaction with the overlying mantle wedge.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 559, abstract only.MantleUHP, subduction
DS200712-0674
2006
Scambelluri, M.Malaspina, N., Hermann, J., Scambelluri, M., Compagnoni, R.Polyphase inclusions in garnet orthopyroxenite (Dabie Shan, China) as monitors for metasomatism and fluid related trace element transfer in subduction zone.Geochimica et Cosmochimica Acta, In press availableChinaPeridotite, Maowu ultramafic complex, metasomatism
DS200812-1013
2008
Scambelluri, M.Scambelluri, M., Petke, T., Van Rosemund, H.L.M.Majoritic garnets monitor deep subsduction fluid flow and mantle dynamics.Geology, Vol. 36, 1, pp.MantleGeodynamics
DS201112-0635
2010
Scambelluri, M.Malaspina, N., Scambelluri, M., Poli, S., Van Roermund, H.L.M., Langenhorst, F.The oxidation state of mantle wedge majoritic garnet websterites metasomatised by C-bearing subduction fluids.Earth and Planetary Science Letters, Vol. 298, 3-4, pp. 417-426.MantleMetasomatism
DS201112-1047
2011
Scambelluri, M.Timm, J., Scambelluri, M., Frische, M., Barnes, J.D., Bach, W.Dehydration of subducting serpentinite: implications for halogen mobility in subduction zones and the deep halogen cycle.Earth and Planetary Science Letters, Vol. 308, 1-2, pp. 65-76.MantleSubduction
DS201812-2853
2018
Scambelluri, M.Murri, M., Mazzucchelli, M.L., Campomenosi, N., Korsakov, A.V., Prencipe, M., Mihailova, B.D., Scambelluri, M., Angel, R.J., Alvaro, M.Raman elastic geobarometry for anisotropic mineral inclusions. MirAmerican Mineralogist, Vol. 103, pp. 1869-1872.Russiamineral inclusions

Abstract: Elastic geobarometry for host-inclusion systems can provide new constraints to assess the pressure and temperature conditions attained during metamorphism. Current experimental approaches and theory are developed only for crystals immersed in a hydrostatic stress field, whereas inclusions experience deviatoric stress. We have developed a method to determine the strains in quartz inclusions from Raman spectroscopy using the concept of the phonon-mode Grüneisen tensor. We used ab initio Hartree-Fock/Density Functional Theory to calculate the wavenumbers of the Raman-active modes as a function of different strain conditions. Least-squares fits of the phonon-wavenumber shifts against strains have been used to obtain the components of the mode Grüneisen tensor of quartz (??m1 and ?m3?) that can be used to calculate the strains in inclusions directly from the measured Raman shifts. The concept is demonstrated with the example of a natural quartz inclusion in eclogitic garnet from Mir kimberlite and has been validated against direct X-ray diffraction measurement of the strains in the same inclusion.
DS201912-2768
2019
Scambelluri, M.Alvaro, M., Mazzucchelli, M.L., Angel, R.J., Murri, M., Campmenosi, N., Scambelluri, M., Nestola, F., Korsakov, A., Tomilenko, A.A., Marone, F., Morana, M.Fossil subduction recorded by quartz from the coesite stability field. GeobarometryGeology, in press, 5p. PdfRussia, Yakutiadeposit - Mir

Abstract: Metamorphic rocks are the records of plate tectonic processes whose reconstruction relies on correct estimates of the pressures and temperatures (P-T) experienced by these rocks through time. Unlike chemical geothermobarometry, elastic geobarometry does not rely on chemical equilibrium between minerals, so it has the potential to provide information on overstepping of reaction boundaries and to identify other examples of non-equilibrium behavior in rocks. Here we introduce a method that exploits the anisotropy in elastic properties of minerals to determine the unique P and T of entrapment from a single inclusion in a mineral host. We apply it to preserved quartz inclusions in garnet from eclogite xenoliths hosted in Yakutian kimberlites (Russia). Our results demonstrate that quartz trapped in garnet can be preserved when the rock reaches the stability field of coesite (the high-pressure and high-temperature polymorph of quartz) at 3 GPa and 850 °C. This supports a metamorphic origin for these xenoliths and sheds light on the mechanisms of craton accretion from a subducted crustal protolith. Furthermore, we show that interpreting P and T conditions reached by a rock from the simple phase identification of key inclusion minerals can be misleading.
DS202007-1127
2020
Scambelluri, M.Cannao, E., Tiepolo, M., Bebout, G.E., Scambelluri, M.Into the deep and beyond: carbon and nitrogen subduction recycling in secondary peridotites. Gagnone metaperidotitesEarth and Planetary Science Letters, Vol. 543, 116328 14p. PdfEurope, Switzerland, Alpsboron diamonds

Abstract: Understanding the volatile cycles at convergent margins is fundamental to unravel the Earth's evolution from primordial time to present. The assessment of fluid-mobile and incompatible element uptake in serpentinites via interaction with seawater and subduction-zone fluids is central to evaluate the global cycling of the above elements in the Earth's mantle. Here, we focus on the carbon (C), nitrogen (N) and C isotope compositions of chlorite harzburgites and garnet peridotites deriving from subduction-zone dehydration of former oceanic dehydration of serpentinite - i.e., metaperidotites (Cima di Gagnone, Swiss Central Alps) with the aim of evaluating the contribution of these rocks to the global C-N cycling. These ultramafic rocks, enclosed as lenses in a metasedimentary mélange, represent the destabilization of antigorite and chlorite at high-pressure/temperature (P/T) along a slab-mantle interface. Chlorite- and garnet-bearing rocks have similar ranges in C concentration ([C] = 210 - 2465 ppm and 304 - 659 ppm, respectively), with one magnesite-bearing chlorite harzburgite hosting 11000 ppm C. The average N concentrations ([N]) of the garnet peridotites (54 ± 15 ppm, one standard deviation indicated) are higher than those of the chlorite harzburgites (29 ± 6 ppm). The C of total C (TC) and total organic C (TOC) values of the Gagnone metaperidotites range from -12.2 to -17.8‰ and from -27.8 to -26.8‰, respectively, excluding the magnesite-bearing chlorite harzburgites with higher values of -7.2‰ (TC) and -21.2‰ (TOC). The [C] of these rocks are comparable to those of serpentinites form modern and ancient oceanic environments and with [C] of high-P serpentinites. However, the lack of preserved serpentinite precursors makes it difficult to determine whether release of H2O during high-P breakdown of antigorite and chlorite is coupled with significant C release to fluids. The C values appear to reflect mixing between seawater-derived carbonate and a reduced C source and a contribution from the host metasedimentary rocks ([C] = 301 ppm; [N] = 33 ppm; TC C = -24.4‰; TOC C = -27.0‰) cannot be completely excluded. The C-O isotope composition of the carbonate in magnesite-bearing chlorite harzburgites is compatible with progressive devolatilization at oxidized conditions, whereas the signatures of the majority of the other Gagnone samples appear to reflect different degree of interaction with sedimentary fluids. The [N] of the Gagnone metaperidotites are higher than those of oceanic and subducted serpentinites and show a range similar to that of high-P antigorite-serpentinites from mantle wedges. This enrichment is compatible with fluid-mediated chemical exchange with the surrounding metasedimentary rocks leading to strong modification of the Gagnone metaperidotites' geochemistry during prograde subduction along the slab-mantle interface. Comparing the C data reported in this study with published C values for diamonds, we suggest that the volatile recycling via Gagnone-like metaperidotites in subduction zones could contribute to deep-Earth diamond genesis and in particular to the formation of blue boron (B)-bearing diamonds. Our results highlight that the subduction of secondary peridotites evolved along the slab-mantle interface is a viable mechanism to inject volatiles into the deep mantle, particularly in hotter geothermal regimes such as the ones active during the early Earth's history.
DS202009-1615
2020
Scambelluri, M.Cannao, E., Scambelluri, M., Bebout, G.E., Agostini, S., Pettke, T., Godard, M., Crispini, L.Ophicarbonate evolution from seafloor to subduction and implications for deep-Earth C cycling.Chemical Geology, Vol. 546, 119626 29p. PdfMantlecarbon, subduction

Abstract: The chemical and physical processes operating during subduction-zone metamorphism can profoundly influence the cycling of elements on Earth. Deep-Earth carbon (C) cycling and mobility in subduction zones has been of particular recent interest to the scientific community. Here, we present textural and geochemical data (CO, Sr isotopes and bulk and in-situ trace element concentrations) for a suite of ophicarbonate rocks (carbonate-bearing serpentinites) metamorphosed over a range of peak pressure-temperature (P-T) conditions together representing a prograde subduction zone P-T path. These rocks, in order of increasing peak P-T conditions, are the Internal Liguride ophicarbonates (from the Bracco unit, N. Apennines), pumpellyite- and blueschist-facies ophicarbonates from the Sestri-Voltaggio zone (W. Ligurian Alps) and the Queyras (W. Alps), respectively, and eclogite-facies ophicarbonates from the Voltri Massif. The Bracco oceanic ophicarbonates retain breccia-like textures associated with their seafloor hydrothermal and sedimentary origins. Their trace element concentrations and ?18OVSMOW (+15.6 to +18.2‰), ?13CVPDB (+1.1 to +2.5‰) and their 87Sr/86Sr (0.7058 to 0.7068), appear to reflect equilibration during Jurassic seawater-rock interactions. Intense shear deformation characterizes the more deeply subducted ophicarbonates, in which prominent calcite recrystallization and carbonation of serpentinite clasts occurred. The isotopic compositions of the pumpellyite-facies ophicarbonates overlap those of their oceanic equivalents whereas the most deformed blueschist-facies sample shows enrichments in radiogenic Sr (87Sr/86Sr?=?0.7075) and depletion in 13C (with ?13C as low as ?2.0‰). These differing textural and geochemical features for the two suites reflect interaction with fluids in closed and open systems, respectively. The higher-P-metamorphosed ophicarbonates show strong shear textures, with coexisting antigorite and dolomite, carbonate veins crosscutting prograde antigorite foliation and, in some cases, relics of magnesite-nodules enclosed in the foliation. These rocks are characterized by lower ?18O (+10.3 to 13.0‰), enrichment in radiogenic Sr (87Sr/86Sr up to 0.7096) and enrichment in incompatible and fluid-mobile element (FME; e.g., As, Sb, Pb). These data seemingly reflect interaction with externally-derived metamorphic fluids and the infiltrating fluids likely were derived from dehydrating serpentinites with hybrid serpentinite-sediment compositions. The interaction between these two lithologies could have occurred prior to or after dehydration of the serpentinites elsewhere. We suggest that decarbonation and dissolution/precipitation processes operating in ancient subduction zones, and resulting in the mobilization of C, are best traced by a combination of detailed field and petrographic observations, C, O and Sr isotope systematics (i.e., 3D isotopes), and FME inventories. Demonstration of such processes is key to advancing our understanding of the influence of subduction zone metamorphism on the mobilization of C in subducting reservoirs and the efficiency of delivery of this C to depths beneath volcanic arcs and into the deeper mantle.
DS201212-0280
2012
Scamberlluri, M.Halama, R., Bebout, G.E., John, T., Scamberlluri, M.Nitrogen recycling in subducted mantle rocks and implications for the global nitrogen cycle.International Journal of Earth Sciences, in press available 19p.MantleSubduction
DS1987-0653
1987
Scambos, T.A.Scambos, T.A.Strontium and neodymium isotope ratios for the Missouri breaks diatremes,central MontanaGeological Society of America, Vol. 19, No. 7 annual meeting abstracts, p.830. abstracMontanaDiatreme
DS1987-0654
1987
Scambos, T.A.Scambos, T.A., Smyth, J.R., McCormick, T.C.Crystal structure refinement of high sanidine from the upper mantleAmerican Mineralogist, Vol. 72, pp. 973-978South AfricaRoberts Victor, Analyses
DS1989-1346
1989
Scambos, T.A.Scambos, T.A., Farmer, G.L.lead isotopic compositions of alkalic igneous rocks from central MontanaEos, Vol. 70, No. 15, April 11, p. 503. (abstract.)MontanaMissouri Breaks Diatreme, Rocky Boys, Winnett sill, Diatremes
DS1991-1508
1991
Scambos, T.A.Scambos, T.A.Isotopic and trace-element characteristics of the central Montana alkalic province kimberlite-alnoite suiteGuidebook of the Central Montana Alkalic Province, ed. Baker, D.W., Berg. R., No. 100, pp. 93-110Montanakimberlite, alnoite
DS1991-1509
1991
Scambos, T.A.Scambos, T.A.Geochemistry and source characteristics of alkalic igneous rocks of centralMontana; III detection of kimberlitic diatremes using landsatPh.d. thesis University of Colorado, Boulder, 261pMontanaPetrology, alkaline rocks, Kimberlitic diatremes
DS2001-0342
2001
Scamelluri, M.FruhGreen, G.L., Scamelluri, M., Vallis, F.Oxygen and Hydrogen isotope ratios of high pressure ultramafic rocks: implications for fluid sources and mobility mantle...Contributions to Mineralogy and Petrology, Vol. 141, No. 1, pp. 145-59.MantleSubduction - hydrous mantle, Oxygen, Hydrogen, Geochronology
DS200912-0671
2009
Scamelluri, M.Scamelluri, M., Pettke, T., Van Roermund, H.L.M.Deep subduction fluids and their interaction with the mantle wedge.Goldschmidt Conference 2009, p. A1165 Abstract.MantleSubduction
DS2001-0108
2001
Scammell, R.J.Bethune, K.M., Scammell, R.J.Thermotectonic reworking of Archean crust by Trans Hudsonian orogenesis - Eqe Bay region.Geological Association of Canada (GAC) Annual Meeting Abstracts, Vol. 26, p.13, abstract.Northwest Territories, Baffin Island, NunavutGeology - greenstone belts
DS200912-0580
2009
Scanchez, L.E.Perez, F., Scanchez, L.E.Assessing the evolution of sustainability reporting in the mining sector. ( figures and information from 2002-2006)Environmental Management, Vol. 43, pp. 949-961.GlobalCorporate sustainability - CSR not specific to diamonds
DS201412-0004
2013
Scandael, E.Agrosi, G., Tempesta, G., Scandael, E., Harris, J.W.Growth and post-growth defects in a diamond from Finsch mine ( South Africa).European Journal of Mineralogy, Vol. 25, pp. 551-559.Africa, South AfricaDeposit - Finsch
DS1998-1468
1998
ScandaleTitkov, S.V., Bershov, Scandale, Saparin, ChukichevNickel structural impurities in natural diamonds7th International Kimberlite Conference Abstract, pp. 911-13.Russia, Yakutia, UralsDiamond morphology, Nickel inclusions
DS201604-0589
2016
Scandale, E.Agrosi, G., Nestola, F., Tempestra, G., Bruno, M., Scandale, E., Harris, J.X-ray topographic study of a diamond from Udachnaya: implications for the genetic nature of inclusions.Lithos, Vol. 248-251, pp. 153-159.RussiaDeposit - Udachnaya

Abstract: In recent years, several studies have focused on the growth conditions of the diamonds through the analysis of the mineral inclusions trapped in them. In these studies, it is crucial to distinguish between protogenetic, syngenetic and epigenetic inclusions. X-ray topography (XRDT) can be a helpful tool to verify, in a non-destructive way, the genetic nature of inclusions in diamond. With this aim, a diamond from the Udachnaya kimberlite, Siberia, was investigated. The diamond, previously studied by Nestola et al. (2011), has anomalous birefringence and the two largest olivines have typical “diamond-imposed” shapes. The study of the topographic images shows that the diamond exhibits significant deformation fields related to post growth plastic deformation. The absence of dislocations starting from the olivine inclusions, and the dark contrasts around them represent the main results obtained by XRDT, contributing to the elucidation of the relationships between the diamond and the olivines at the micron-meter scale. The dark halo surrounding the inclusions was likely caused by the effect of different thermo-elastic properties between the diamond and the inclusions. The absence of dislocations indicates that the diamond-imposed morphology did not produce the volume distortion commonly associated with the entrapment of the full-grown inclusions and, thus, only based on such evidence, a syngenetic origin could be proposed. In addition, stepped figures optically observed at the interface between diamond and one of the olivines suggest processes of selective partial dissolution that would contribute to a change in the final morphology of inclusions. These results show that a diamond morphology may be imposed to a full-grown (protogenetic) olivine during their encapsulation, suggesting that the bulk of the inclusion is protogenetic, whereas its more external regions, close to the diamond-inclusion interface, could be syngenetic.
DS1989-1347
1989
Scandella, S.Scandella, S.Black diamonds of type IIbJournal of Gemology, Vol. 21, No. 7, July p. 411GlobalDiamond morphology, Black diamonds
DS2000-0198
2000
ScandolaraDallagnol, R., Lafon, Fraga, Scandolara, BarrosThe Precambrian evolution of the Amazonian Craton: one of the last unknown Precambrian terranes in the world.Igc 30th. Brasil, Aug. abstract only 1p.Brazil, Guyana ShieldCraton - Amazon, Tectonics
DS200512-1092
2004
Scandolara, J.Tohver, E., Van der Pluijm, B., Mezger, B., Essene, E., Scandolara, J., Rizzotto, G.Significance of the Nova Brasilandia metasedimentary belt in western Brazil: redefining the Mesoproterozoic boundary of the Amazon Craton.Tectonics, Vol. 23, 6, TC 6004 1029/2003 TC001563South America, BrazilCraton - Amazon
DS200512-1091
2005
Scandolara, J.E.Tohver, E., Van der Phuijm, B.A., Mezger, K., Scandolara, J.E., Essene, E.J.Two stage tectonic history of the SW Amazon Craton in the late Mesoproterozoic in the late Mesoproterozoic: identifying a cryptic suture zone.Precambrian Research, Vol. 137, 1-2, Apr.28, pp. 35-59.South America, BrazilParagua Craton, tectonics, geochronology
DS1995-1663
1995
Scandolo, S.Scandolo, S.Pressure induced transformation path of graphite to diamondPhys. Rev. Letters, Vol. 74, No. 20, May 15, pp. 4015-4018.GlobalDiamond genesis, Graphite -diamond
DS2003-1217
2003
Scandolo, S.Scandolo, S., Jeanloz, R.The centers of planets. In laboratories and computers, shocked and squeezed matterAmerican Scientist, Vol. 91, Nov-Dec. pp. 516-525.MantleDiamond genesis, metallic hydrogen, shock waves, sky, i
DS200412-1739
2003
Scandolo, S.Scandolo, S., Jeanloz, R.The centers of planets. In laboratories and computers, shocked and squeezed matter turns metallic, coughs up diamonds and revealAmerican Scientist, Vol. 91, Nov-Dec. pp. 516-525.MantleDiamond genesis, metallic hydrogen, shock waves, sky, i
DS2001-1025
2001
Scandone, R.Scandone, R., Giacomelli, L.The slow boiling of magma chambers and the dynamics of explosive eruptionsJour. Vol. Geotherm. Res., Vol. 110, No. 1-2, Sept. pp. 121-36.GlobalMagma, Phreatomagmatic
DS200712-0943
2007
Scandone, R.Scandone, R., Cashman, K.V., Malone, S.D.Magma supply, magma ascent and the style of volcanic eruptions.Earth and Planetary Science Letters, Vol. 253, 3-4, Jan. 30, pp. 513-529.MantleMagmatism
DS201112-0797
2011
Scandone, R.Piegari, E., Di Maio, R., Scandone, R., Milano, L.A cellular automaton model for magma ascent: degassing and styles of volcanic eruptions.Journal of Geothermal Volcanology and Research, Vol. 202, 1-2, pp. 22-28.MantleMagmatism
DS1991-1510
1991
Scanvic, J-Y.Scanvic, J-Y.Remote sensing in mineral exploration fields of application and futureperspectives.*IN FRE.Chron. Rech. Miniere, No. 505, pp. 3-6GlobalOverview, Remote Sensing
DS2001-1028
2001
ScaordaniSchingaro, E., Scaordani, Malitesta, Rudolf, LouetteXPS investigation on natural Ti bearing garnetsPlinius, No. 24, p. 195. abstractGlobalMineralogy - garnet
DS1986-0105
1986
Scarfe, C.Brearley, M., Scarfe, C.Dissolution rates of upper mantle minerals in an alkali basalt melt at high pressure: an experimental study and implications for ultramafic xenolithsurvivalJournal of Petrology, Vol. 27, No. 5, pp. 1157-1182South AfricaHawaii, Roberts Victor
DS1981-0165
1981
Scarfe, C.M.Fujii, T., Scarfe, C.M.Petrology and Ultramafic Nodules from Boss Mountain, Central British Columbia.Geological Association of Canada (GAC), No. 6, P. A20. (ABSTRACT VOLUME).Canada, British ColumbiaPetrology
DS1981-0166
1981
Scarfe, C.M.Fujii, T., Scarfe, C.M.Partial Melting of Spinel Lherzolite and its Bearing on The origin of Morbs.Geological Society of America (GSA), Vol. 13, No. 7, P. 456. (abstract.)L.Canada, British ColumbiaPetrology
DS1982-0213
1982
Scarfe, C.M.Fujii, T., Scarfe, C.M.Petrology of Ultramafic Nodules from West Kettle River, Near Kelowna, Southern British Columbia.Contributions to Mineralogy and Petrology, Vol. 80, No. 4, PP. 297-306.Canada, British ColumbiaPetrology, Websterite, Inclusions, Basanite, Mineralogy
DS1984-0173
1984
Scarfe, C.M.Brearley, M., Scarfe, C.M.Amphibole in a Spinel Lherzolite Xenolith - Evidence for Volatiles and Partial Melting in the Upper Mantle Beneath Southern British Columbia.Canadian Journal of Earth Sciences, Vol. 21, No. 9, SEPTEMBER PP. 1067-1072.Canada, British ColumbiaBlank
DS1984-0174
1984
Scarfe, C.M.Brearley, M., Scarfe, C.M., Fujii, T.The Petrology of Ultramafic Xenoliths from Summit Lake, Near Prince George British Columbia.Contributions to Mineralogy and Petrology, Vol. 88, PP. 53-63.Canada, British ColumbiaBasanite, Microprobe Analyses, Nodules, Spinel Lherzolite, Wehrlite
DS1985-0205
1985
Scarfe, C.M.Fujii, T., Scarfe, C.M.Composition of Liquids Coexisting with Spinel Lherzolite At10 Kbar and the Genesis of Morbs.Contributions to Mineralogy and Petrology, Vol. 90, No. 1, PP. 18-28.GlobalPetrology
DS1985-0658
1985
Scarfe, C.M.Takahashi, E., Scarfe, C.M.Melting of Peridotite to 14 Gpa and the Genesis of KomatiiteNature., Vol. 315, No. 6020, JUNE 13TH. PP. 566-568.Lesotho, United States, Colorado Plateau, New MexicoLherzolite, Kilbourne Hole, Thaba Putsoa, Chemical Analysis
DS1986-0796
1986
Scarfe, C.M.Takahashi, E., Ito, E., Scarfe, C.M.Melting and subsolidus phase relation of mantle peridotite up to 25 GPaProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 208-210New Mexico, LesothoKilborne Hole, Thaba Putsoa
DS1987-0084
1987
Scarfe, C.M.Canil, D., Brearley, M., Scarfe, C.M.Petrology of ultramafic xenoliths from Rayfield River southcentral British ColumbiaCanadian Journal of Earth Sciences, Vol. 24, No. 8, August pp. 1679-1687British ColumbiaMantle, Heat flow
DS1988-0105
1988
Scarfe, C.M.Canil, D., Scarfe, C.M., Ozawa, K.Phlogopite in mantle xenoliths from the Kostal Lake volcanic center Wells Gray Park, British ColumbiaV.m. Goldschmidt Conference, Program And Abstract Volume, Held May, p. 35 AbstractBritish ColumbiaAlkaline
DS1988-0106
1988
Scarfe, C.M.Canil, D., Virgo, D., Scarfe, C.M.Oxidation state of spinel lherzolite xenoliths from British Columbia: a57Fe Mossbauer investigationCarnegie Institute Annual Report of the Director of the Geophysical, No. 2102, issued Dec. 1988, pp. 18-22British ColumbiaSummit Lake, Rayfield River, West Kettle River
DS1989-0204
1989
Scarfe, C.M.Canil, D., Scarfe, C.M.Origin of phlogopite in mantle xenoliths from KostalLake, Wells GrayPark, British ColumbiaJournal of Petrology, Vol. 30, No. 5, October pp. 1159-1180British ColumbiaMantle, Xenoliths -mineral chemis
DS1989-0205
1989
Scarfe, C.M.Canil, D., Scarfe, C.M.Solidus for peridotite + CO2 to 12 GPa and implications for The origin of melilitites and kimberlitesGeological Association of Canada (GAC) Annual Meeting Program Abstracts, Vol. 14, p. A93. (abstract.)GlobalExperimental petrology
DS1989-0206
1989
Scarfe, C.M.Canil, D., Scarfe, C.M.Partial melting in peridotite-CO2 systems at 5 to 9 GPaEos, Vol. 70, No. 15, April 11, p. 483. (abstract.)GlobalExperimental Petrology, Peridotite
DS1989-1514
1989
Scarfe, C.M.Tronnes, R.G., Takahashi, E., Scarfe, C.M.Stability and phase relations of K-richterite and phlogopite to 15 GPaGeological Association of Canada (GAC) Annual Meeting Program Abstracts, Vol. 14, p. A93. (abstract.)GlobalExperimental petrology, Richterite
DS1990-0269
1990
Scarfe, C.M.Canil, D., Scarfe, C.M.Phase relations in peridotite and CO2 systems to 12 GPa: implications For the origin of kimberlite abd carbonate stability in the earth's upper mantleJournal of Geophysical Research, Vol. 95, No. B 10, September 10, pp. 15, 805-15, 816GlobalExperimental petrology, Kimberlite
DS1990-0270
1990
Scarfe, C.M.Canil, D., Virgo, D., Scarfe, C.M.Oxidation state of mantle xenoliths from British Columbia, CanadaContributions to Mineralogy and Petrology, Vol. 104, pp. 453-462British ColumbiaMantle xenoliths Boss Mountain, Rayfield River, Kostal Lake, West Kettle
DS1990-1480
1990
Scarfe, C.M.Tronnes, R.G., Scarfe, C.M.Experimental constraints on the relative stability of phlogopite and amphibole in subducted lithosphereGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) Vancouver 90 Program with Abstracts, Held May 16-18, Vol. 15, p. A132. AbstractGlobalExperimental petrology, Richterite
DS1990-1596
1990
Scarfe, C.M.Xianyu Xue, Baadsgaard, H., Irving, A.J., Scarfe, C.M.Geochemical and isotopic characteristics of lithospheric mantle beneath West Kettle River, British Columbia: evidence from ultramafic xenoliths #2Journal of Geophysical Research, Vol. 95, No. B 10, September 10, pp. 15, 879-15, 891British ColumbiaGeochemistry, Mantle xenoliths
DS1994-1071
1994
Scarfe, C.M.Luth, R.W., Scarfe, C.M.Carbonation reactions in eclogites at high pressure: implications for carbonic fluid in the mantle.Mineralogical Magazine, Vol. 58A, pp. 543-544. AbstractMantleEclogites
DS1990-1597
1990
Scarfe, C.S.Xianyu Xue, Baadsgard, H., Irvingm A.J., Scarfe, C.S.Geochemical and isotopic characteristics of lithospheric mantle beneath West Kettle River British Columbia: evidence from ultramafic xenoliths #1Eos, Vol. 71, No. 28, July 10, p. 824. AbstractBritish ColumbiaMantle, Xenolith
DS201112-0695
2011
Scarlato, P.Mollo, S., Vinciguerra, S., Lezzi, G., Iarocci, A., Scarlato, P., Heap, M.J., Dingwell, D.B.Volcanic edifice weakening via devolatization reactions.Geophysical Journal International, In press, availableMantleVolcanism - not specific to diamonds
DS201709-2059
2017
Scarlato, P.Stagno, V., Kono, Y., Greaux, S., Kebukawa, Y., Stopponi, V., Scarlato, P., Lustrino, M., Irifune, T.From carbon in meteorites to carbonatite rocks on Earth.Goldschmidt Conference, abstract 1p.Globalcarbonatite

Abstract: The composition of the early Earth’s atmosphere is believed to result from significant magma outgassing during the Archaean eon. It has been widely debated whether the oxygen fugacity (fo2) of the Earth’s mantle has remained constant over the last ~3.8 Ga to levels where volatiles were mostly in their mobile form [1,2], or whether the mantle has experienced a gradual increase of its redox state [3]. Both hypotheses raise fundamental questions on the effect of composition of the early Earth’s accreting material, the origin and availability of primordial carbon in Earth’s interior, and the migration rate of CO2-rich magmas. In addition, the occurrence in nature of carbonatites (or silicate-carbonatitic rocks), diamonds and carbides indicate a dominant control of the mantle redox state on the volatile speciation over time and, maybe, on mechanisms of their formation, reaction and migration through the silicate mantle. A recent model has been developed that combines both experimental results on the fo2 of preserved carbonaceous chondrites at high pressure and thermodynamic predictions of the the temporal variation of the mantle redox state, with the CO2-bearing magmas that could form in the early asthenospheric mantle. Since any variation in melt composition is expected to cause significant changes in the physical properties (e.g., viscosity and density), the migration rate of these magmas has been determined using recent in situ viscosity data on CO2-rich melts with the falling sphere technique. Our results allow determining the composition of CO2- bearing magmas as function of the increasing mantle redox state over time, and the mechanisms and rate for exchange of carbon between mantle reservoirs.
DS201904-0790
2019
Scarlato, P.Ubide, T., Mollo, S., Zhao, J-x., Nazzari, M., Scarlato, P.Sector zoned clinopyroxene as a recorder of magma history, eruption triggers, and ascent rates.Geochimica et Cosmochimica Acta, dor:10.1016/j.gca.2019.02.021Mantlemagmatism

Abstract: Sector-zoned clinopyroxene is common in igneous rocks, but has been overlooked in the study of magmatic processes. Whilst concentric zoning is commonly used as a record of physicochemical changes in the melt feeding crystal growth, clinopyroxene is also highly sensitive to crystallisation kinetics. In sector-zoned crystals, the fidelity of compositional changes as recorders of magma history is dubious and the interplay between thermodynamic and kinetic controls remains poorly understood. Here we combine electron probe and laser ablation micro-chemical maps of titanaugite crystals from Mt. Etna (Sicily, Italy) to explore the origin of sector zoning at the major and trace element levels, and its implications for the interpretation of magmatic histories. Elemental maps afford the possibility to revisit sector zoning from a spatially controlled perspective. The most striking observation is a clear decoupling of elements into sectors vs. concentric zones within single crystals. Most notably, Al-Ti enrichments and Si-Mg depletions in the prism sectors {1?0?0}, {1?1?0} and {0?1?0} relative to the hourglass (or basal) sectors {?1?1?1} correlate with enrichments in rare earth elements and highly charged high field strength elements due to cation exchanges driven by kinetic effects. In contrast, transition metals (Cr, Ni, Sc) show little partitioning into sectors and strong enrichments in concentric zones following resorbed surfaces, interpreted as evidence of mafic recharge and magma mixing. Our results document that kinetic partitioning has minor effects on the compositional variations of cations with low charge relative to the ideal charge/radius of the structural site they occupy in the clinopyroxene lattice. We suggest that this may be due to a lower efficiency in charge balance mechanisms compared to highly charged cations. It follows that compatible metals such as Cr can be considered trustworthy recorders of mafic intrusions and eruption triggers even in sector-zoned crystals. We also observe that in alkaline systems where clinopyroxene crystallisation takes place at near-equilibrium conditions, sector zoning should have little effect on Na-Ca partitioning and in turn, on the application of experimentally calibrated thermobarometers. Our data show that whilst non-sector-zoned crystals form under relatively stagnant conditions, sector zoning develops in response to low degrees of undercooling, such as during slow magma ascent. Thus, we propose that the chemistry of sector-zoned crystals can provide information on magma history, eruption triggers, and possibly ascent rates.
DS202004-0534
2020
Scarlato, P.Stagno, V., Stopponi, V., Kono, Y., D'Arco, A., Lupi, S., Romano, C., Poe, B.T., Foustoukos, D.J., Scarlato, P., Manning, C.E.The viscosity and atomic structure of volatile bearing melililititic melts at high pressure and temperature and the transport of deep carbon.Minerals MDPI, Vol. 10, 267 doi: 10.23390/min10030267 14p. PdfMantleMelililite, carbon

Abstract: Understanding the viscosity of mantle-derived magmas is needed to model their migration mechanisms and ascent rate from the source rock to the surface. High pressure-temperature experimental data are now available on the viscosity of synthetic melts, pure carbonatitic to carbonate-silicate compositions, anhydrous basalts, dacites and rhyolites. However, the viscosity of volatile-bearing melilititic melts, among the most plausible carriers of deep carbon, has not been investigated. In this study, we experimentally determined the viscosity of synthetic liquids with ~31 and ~39 wt% SiO2, 1.60 and 1.42 wt% CO2 and 5.7 and 1 wt% H2O, respectively, at pressures from 1 to 4.7 GPa and temperatures between 1265 and 1755 °C, using the falling-sphere technique combined with in situ X-ray radiography. Our results show viscosities between 0.1044 and 2.1221 Pa•s, with a clear dependence on temperature and SiO2 content. The atomic structure of both melt compositions was also determined at high pressure and temperature, using in situ multi-angle energy-dispersive X-ray diffraction supported by ex situ microFTIR and microRaman spectroscopic measurements. Our results yield evidence that the T-T and T-O (T = Si,Al) interatomic distances of ultrabasic melts are higher than those for basaltic melts known from similar recent studies. Based on our experimental data, melilititic melts are expected to migrate at a rate ~from 2 to 57 km•yr?1 in the present-day or the Archaean mantle, respectively.
DS2003-0276
2003
Scarlett, N.V.Y.Cooper, S.A., MacRae, C.M., Wilson, N.C., Scarlett, N.V.Y., Marx, W.T.Diamond coatings that affect diamond recoveries on grease tables investigated by8ikc, Www.venuewest.com/8ikc/program.htm, Session 1 POSTER abstractSouth AfricaKimberlite geology and economics, Technology - recovery, Perdevlei, Kareevlei
DS1993-1385
1993
Scarpa, R.Scarpa, R.Seismic tomography and modeling of complex geological structuresJournal of Applied Geophysics, Vol. 30, No. 1-2, Special issue, pp. 119-130GlobalGeophysics, Tomography
DS1982-0538
1982
Scarratt, K.Scarratt, K.The Detection of Treated DiamondsInstitute of Mining and Metallurgy. Transactions, Vol. 9L, SECT. A., PP. A131-132.GlobalBlank
DS1989-1348
1989
Scarratt, K.Scarratt, K.Notes: How to read absorption curves. Describes10 de Beers synthetic yellow diamondsJournal of Gemology, Vol. 21, No. 6, pp. 339-346GlobalDiamond synthesis, FTIR spectrometer
DS1992-0491
1992
Scarratt, K.Fritsch, E., Scarratt, K.Natural color nonconductive gray to blue diamondsGems and Gemology, Notes and new techniques, Vol. 28, Spring pp. 35-42GlobalDiamond, Morphology, colour
DS1993-0467
1993
Scarratt, K.Fritsch, E., Scarratt, K.Gemmological properties of Type 1a diamonds with an unusually high hydrogencontent.Journal of Gemology, Vol. 23, No. 8, October pp. 451-460.GlobalDiamond morphology, Hydrogen content
DS1994-0870
1994
Scarratt, K.Kammerling, R.C., Scarratt, K., et al.Myanmar and its gems - an update. Diamonds mentioned p. 33Journal of Gemology, Vol. 24, No. 1, pp. 3-40.GlobalGemstones, Diamond
DS200612-1232
2006
Scarratt, K.Scarratt, K., Shor, R.The Culli nan diamond centennial: a history and gemological analysis of Culli nans I and II.Gems & Gemology, Vol. 42, 2, Summer, pp. 120-132.Africa, South AfricaHistory - Cullinan
DS201811-2606
2015
Scarratt, K.Scarratt, K.Beautifying emeralds…. The perennial debate.InColor, December pp. 50-55.Globalemeralds
DS1982-0539
1982
Scarratt, K.V.G.Scarratt, K.V.G.Irradiation of DiamondsIn: International Gemological Symposium Proceedings Volume, PP. 205-206.GlobalBlank
DS1982-0540
1982
Scarratt, K.V.G.Scarratt, K.V.G.The Identification of Artificial Coloration in DiamondGems And Gemology, Vol. 18, No. 2, SUMMER, PP. 72-78.GlobalBlank
DS1989-0447
1989
Scarratt, K.V.G.Fritsch, E., Scarratt, K.V.G.Optical properties of one type of natural diamonds with high hydrogencontentDiamond Workshop, International Geological Congress, July 15-16th. editors, pp. 21-22. AbstractGlobalDiamond morphology -natural, Natural diamond Type 1A.
DS2002-0125
2002
ScarrowBea, F., Fershtater,Montero, Whitehouse, Levin, ScarrowRecycling of continental crust into the mantle as revealed by Kytlym dunite zircons, Ural Mountains.Terra Nova, Vol. 13, No. 6, pp. 407-12.RussiaSubduction
DS2000-0114
2000
Scarrow, J.H.Brown, D., Hetzel, R., Scarrow, J.H.Tracking arch ... continent collision subduction zone processes from high pressure rocks in southern UralsJournal of Geological Society of London, Vol. 157, No. 5, Sept.pp. 901-4.Russia, UralsMetamorphism - ultra high pressure (UHP)
DS2000-0862
2000
Scarrow, J.H.Scarrow, J.H., Bea, F., Montero, P., Fershtater, G.Preservation of atypical arc rocks in suturesIgc 30th. Brasil, Aug. abstract only 1p.GlobalSubduction, Tectonics - adakitic
DS2002-1410
2002
Scarrow, J.H.Scarrow, J.H., Ayala, C., Kimbell, G.S.Insights into orogenesis: getting to the root of the continent ocean ocean continent collision in the southern Urals, Russia.Journal of the Geological Society of London, Vol. 159, 6, pp. 659-72.Russia, UralsOrogeny - tectonics
DS2002-1411
2002
Scarrow, J.H.Scarrow, J.H., Ayala, C., Kimbell, G.S.Insights into orogenesis: getting to the root of a continent ocean continent collision, southern Urals, Russia.Journal of the Geological Society of London, Vol. 159, 2, pp. 659-671.Russia, UralsBlank
DS2003-1416
2003
Scarrow, J.H.Vaughan, A.P.M., Scarrow, J.H.K rich mantle metasomatism control of localization and initiation of lithospheric strikeTerra Nova, Vol. 15, 3, June pp. 163-169.MantleTectonics, subduction
DS2003-1417
2003
Scarrow, J.H.Vaughan, A.P.M., Scarrow, J.H.K rich mantle metasomatism control of localization and initiation of lithospheric strikeTerra Nova, Vol. 15, 3, pp. 163-169.MantleBlank
DS2003-1418
2003
Scarrow, J.H.Vaughan, A.P.M., Scarrow, J.H.K rich mantle metasomatism control of localization and initiation of lithospheric strikeTerra Nova, Vol. 15, No. 3, June pp. 163-169.Mantle, GlobalMagmatism - potassic
DS200412-1740
2004
Scarrow, J.H.Scarrow, J.H., Ayala, C., Kimball, G.S.Insights into orogenesis: getting to the root of a continent-ocean-continent collision.Journal of the Geological Society, Vol. 159, 6, pp. 659-671.MantleTectonics, geodynamics
DS200412-2046
2003
Scarrow, J.H.Vaughan, A.P., Scarrow, J.H.Ophiolite obduction phases as a proxy indicator of superplume events?Earth and Planetary Science Letters, Vol. 213, 3-4, pp. 407-16.MantleTectonics
DS200412-2047
2003
Scarrow, J.H.Vaughan, A.P.M., Scarrow, J.H.K rich mantle metasomatism control of localization and initiation of lithospheric strike slip faulting.Terra Nova, Vol. 15, 3, June pp. 163-169.MantleTectonics, subduction
DS200412-2048
2003
Scarrow, J.H.Vaughan, A.P.M., Scarrow, J.H.K rich mantle metasomatism control of localization and initiation of lithospheric strike slip faulting.Terra Nova, Vol. 15, no. 3, June pp. 163-169.MantleMagmatism - potassic
DS201612-2283
2016
Scarrow, J.H.Cambeses, A., Garcia-Casco, A., Scarrow, J.H., Montero, P., Perez-Valera, L.A., Bea, F.Mineralogical evidence for lamproite magma mixing and storage at mantle depths: Socovos fault lamproites, SE Spain.Lithos, Vol. 266-267, pp. 182-201.Europe, SpainLamproite

Abstract: Detailed textural and mineral chemistry characterisation of lamproites from the Socovos fault zone, SE Spain Neogene Volcanic Province (NVP) combining X-ray element maps and LA-ICP-MS spot analyses has provided valuable information about mantle depth ultrapotassic magma mixing processes. Despite having similar whole-rock compositions, rocks emplaced in the Socovos fault are mineralogically varied: including type-A olivine-phlogopite lamproites; and type-B clinopyroxene-phlogopite lamproites. The Ol-lacking type-B predates Ol-bearing type-A by c. 2 million years. We propose that the mineralogical variations, which are representative of lamproites in the NVP as a whole, indicate mantle source heterogeneities. Major and trace element compositions of mineral phases suggest both metasomatised harzburgite and veined pyroxenite sources that were most likely closely spatially related. Thin section scale textural and compositional variations in mineral phases reveal heterogeneous mantle- and primitive magma-derived crystals. The variety of crystals points to interaction and mingling-mixing of ultrapotassic magma batches at mantle depths prior crustal emplacement. The mixing apparently occurred in a mantle melting zone with a channelised flow regime and localised magma chambers-reservoirs. Magma interaction was interrupted when the Socovos and other lithosphere-scale faults tore down to the mantle source region, triggering rapid ascent of the heterogeneous lamproite magma.
DS2003-1415
2003
Scarrowm J.H.Vaughan, A.P., Scarrowm J.H.Ophiolite obduction phases as a proxy indicator of superplume events?Earth and Planetary Science Letters, Vol. 213, 3-4, pp. 407-16.MantleTectonics
DS1984-0631
1984
Scatena-Wachel, D.E.Scatena-Wachel, D.E., Jones, A.P.Primary Baddeleyite Zr O2 in Kimberlite from Benfontein South Africa.Mineralogical Magazine., Vol. 48, No. 347, PT. 2, JUNE PP. 257-262.South AfricaMineralogy, Zirconium
DS1994-1534
1994
Schaaf, P.Schaaf, P., Heinrich, W.Geochemical, Strontium-neodymium isotopic and P T dat a on a central Mexican xenolith suite: crustal compositions.Mineralogical Magazine, Vol. 58A, pp. 803-804. AbstractMexicoXenboliths, San Luis Potosi field
DS1989-0244
1989
Schaap, B.D.Chandler, V.W., Schaap, B.D.New bouguer anomaly map of Minnesota35th. Annual Institute On Lake Superior Geology, Proceedings And, pp. 19-20.MinnesotaGeophysics, Midcontinent
DS1991-0256
1991
Schaap, B.D.Chandler, V.W., Schaap, B.D.Bouguer gravity anomaly map of MinnesotaMinnesota geological survey, 1:500, 000 $ 13.50 United StatesMinnesotaGeophysics -gravity, Map
DS200912-0587
2009
Schaber, K.Phillips, B.R., Bunge, H-P., Schaber, K.True polar wander in mantle convection models with multiple, mobile continents.Gondwana Research, Vol. 15, 3-4, pp. 288-196.MantleConvection
DS1997-0635
1997
Schachotko, L.I.Kravchenko, S., Schachotko, L.I., Rass, I.T.Moho discontinuity relief and the distribution of kimberlites and carbonatites in the northern SiberianGlobal Tectonics and Metallogeny, Vol. 6, No. 2, March pp. 137-140.Russia, SiberiaMantle - MOHO, Platform
DS1995-1020
1995
Schachoto, L.I.Kravchenko, S.M., Schachoto, L.I., Rass, I.T.The MOHO discontinuity relief and the distribution of kimberlites and carbonatites over the northern craton.Iagod Giant Ore Deposits Workshop, J. Kutina, 10p.RussiaSiberian Platform, Distribution -kimberlites
DS201212-0568
2012
Schaefer, B.Porritt, L.A., Cas, R.A.F., Schaefer, B., McKnight, S.W.Textural analysis of strongly altered kimberlite: examples from the Ekati diamond mine, Northwest Territories, Canada.Canadian Mineralogist, Vol. 50, 3, June pp. 625-641.Canada, Northwest TerritoriesDeposit - Ekati
DS2000-0863
2000
Schaefer, B.F.Schaefer, B.F., Turner, S.P., Rogers, Hawkesworth et al.Rhenium- Osmium (Re-Os) isotope characteristics of postorogenic lavas: implications for nature of young lithospheric mantle...Geology, Vol. 28, No. 6, June pp. 563-6.Colorado Plateau, Tibet, SpainGeochronology - potassic lavas, Mantle depletion - basaltic magmas
DS200612-1446
2006
Schaefer, B.F.Turner, S., Tonarini, S., Bindeman, L., Leeman, W.P., Schaefer, B.F.Boron and oxygen isotopic evidence for recycling of subducted components through the Earth's mantle since 2.5 Ga.Geochimica et Cosmochimica Acta, Vol. 70, 18, 1, p. 28, abstract only.MantleSubduction
DS200712-0076
2007
SChaefer, B.F.Betts, P.G., Giles, D., SChaefer, B.F., Mark, G.1600 -1500 Ma hotspot track in eastern Australia: implications for Mesoproterozoic continental reconstruction.Terra Nova, Vol. 19, 6, pp. 496-501.AustraliaHotspots, plumes
DS202002-0219
2020
Schaefer, B.F.Tilhac, R., Oliveira, B., Griffin, W.L., O'Reilly, S.Y., Schaefer, B.F., Alard, O., Ceuleneer, G., Afonso, J.C., Gregoire, M.Reworking of old continental lithosphere: unradiogenic Os and decoupled Hf-Nd isotopes in sub-arc mantle pyroxenites.Lithos, Vol. 354-355, 19p. pdfEurope, Spainpyroxenites

Abstract: Mantle lithologies in orogenic massifs and xenoliths commonly display strikingly different Hf- and Nd-isotope compositions compared to oceanic basalts. While the presence of pyroxenites has long been suggested in the source region of mantle-derived magmas, very few studies have reported their combined HfNd isotope compositions. We here report the first LuHf data along with ReOs data and S concentrations on the Cabo Ortegal Complex, where the pyroxenite-rich Herbeira massif has been interpreted as remnants of a delaminated arc root. The pyroxenites, chromitites and their host harzburgites show a wide range of whole-rock 187Re/188Os and 187Os/188Os (0.16-1.44), indicating that Re was strongly mobilized, partly during hydrous retrograde metamorphism but mostly during supergene alteration that preferentially affected low-Mg#, low Cu/S pyroxenites. Samples that escaped this disturbance yield an isochron age of 838 ± 42 Ma, interpreted as the formation of Cabo Ortegal pyroxenites. Corresponding values of initial 187Os/188Os (0.111-0.117) are relatively unradiogenic, suggesting limited contributions of slab-derived Os to primitive arc melts such as those parental to these pyroxenites. This interpretation is consistent with radiogenic Os in arc lavas being mostly related to crustal assimilation. Paleoproterozoic to Archean Os model ages confirm that Cabo Ortegal pyroxenites record incipient volcanic arc magmatism on the continental margin of the Western African Craton, as notably documented by zircon UPb ages of 2.1 and 2.7 Ga. LuHf data collected on clinopyroxene and amphibole separates and whole-rock samples are characterized by uncorrelated 176Lu/177Hf and 176Hf/177Hf (0.2822-0.2855), decoupled from Nd-isotope compositions. This decoupling is ascribed to diffusional disequilibrium during melt-peridotite interaction, in good agreement with the results of percolation-diffusion models simulating the interaction of an arc melt with an ancient melt-depleted residue. These models notably show that HfNd isotopic decoupling such as recorded by Cabo Ortegal pyroxenites and peridotites (??Hf(i) up to +97) is enhanced during melt-peridotite interaction by slow diffusional re-equilibration and can be relatively insensitive to chromatographic fractionation. Finally, we discuss the hypothesis that arc-continent interaction may provide preferential conditions for such isotopic decoupling and propose that its ubiquitous recognition in peridotites reflects the recycling of sub-arc mantle domains derived from ancient, reworked SCLM.
DS202003-0374
2020
Schaefer, C.Zubkova, N.V., Chukanov, N.V., Schaefer, C., Kan, K.V., Pekov, I., Pushcharovsky, D.Yu.A1 analogue of chayesite from a lamproite of Canacarix, SE Spain, and its crystal structure.Journal of Mineralogy and Geochemistry ( formerly Neues Jahrbuch fur Mineralogie), in press NOT availableEurope, Spainlamproite
DS1984-0632
1984
Schaefer, H.Schaefer, H., Muller, W.F., Hornemann, U.Shock Effects in MelilitePhysics Chem. Minerals, Vol. 10, No. 3, PP. 121-124.GlobalExperimental Petrology
DS201901-0091
2018
Schaefer, L.Wu, J., Desch, S.J., Schaefer, L., Elkins-Tanton, L.T., Pahlevan, K., Buseck, P.R.Origin of Earth's water: chondritic inheritance plus nebular ingassing and storage of hydrogen in the core.Journal of Geophysical Research: Planets, doei:10.1029/ 2018JE005698Mantlewater

Abstract: People have long had curiosity in the origin of Earth's water (equivalently hydrogen). Solar nebula has been given the least attention among existing theories, although it was the predominating reservoir of hydrogen in our early solar system. Here we present a first model for Earth's water origin that quantifies contribution from the solar nebula in addition to that from chondrites, the primary building blocks of Earth. The model considers dissolution of nebular hydrogen into the early Earth's magma oceans and reaction between hydrogen and iron droplets within the magma ocean. Such processes not only delivered countless hydrogen atoms from the mantle to the core but also generated an appreciable difference in hydrogen isotopic composition (2H/1H ratio) between the mantle and core. Fitting the model to current knowledge about Earth's hydrogen produces best combinations of nebular and chondritic contributions to Earth's water. We find that nearly one out of every 100 water molecules on Earth came from the solar nebula. Our planet hides majority of its water inside, with roughly two oceans in the mantle and four to five oceans in the core. These results suggest inevitable formation of water on sufficiently large rocky planets in extrasolar systems.
DS1996-0398
1996
Schaefer, M.W.Dyer, M.D., McCammon, C., Schaefer, M.W.Mineral spectroscopy: a tribute to Roger C. BurnsGeochemical Society, Book $ 35.00 United StatesGlobalSpectroscopy, Book -ad
DS201012-0668
2010
Schaeffer, A.Schaeffer, A., Bostock, M.G.A low velocity zone atop the transition zone in northwestern Canada.Journal of Geophysical Research, Vol. 115, no. B6, B06302.Canada, Northwest TerritoriesGeophysics - seismics
DS201312-0781
2013
Schaeffer, A.Schaeffer, A.Heterogeneity and anisotropy of the North American upper mantle, imaged using multimode waveform tomography.GEM Diamond Workshop Feb. 21-22, Noted onlyCanadaTomography
DS202006-0920
2020
Schaeffer, A.Foster, A., Darbyshire, F., Schaeffer, A.Anisotropic structure of the central North American craton surrounding the Mid-continent rift: evidence form Rayleigh waves.Precambrian Research, Vol. 342, 18p. PdfUnited States, Canadageophysics - seismics
DS202109-1484
2021
Schaeffer, A.Pearson, D.G., Scott, J.M., Liu, J., Schaeffer, A., Wang, L.H., van Hunen, J., Szilas, K., Chacko, T., Kelemen, P.B. Deep continental roots and cratons.Nature, Vol. 596, pp. 199-210. pdfGlobalcratons

Abstract: The formation and preservation of cratons-the oldest parts of the continents, comprising over 60 per cent of the continental landmass-remains an enduring problem. Key to craton development is how and when the thick strong mantle roots that underlie these regions formed and evolved. Peridotite melting residues forming cratonic lithospheric roots mostly originated via relatively low-pressure melting and were subsequently transported to greater depth by thickening produced by lateral accretion and compression. The longest-lived cratons were assembled during Mesoarchean and Palaeoproterozoic times, creating the stable mantle roots 150 to 250 kilometres thick that are critical to preserving Earth’s early continents and central to defining the cratons, although we extend the definition of cratons to include extensive regions of long-stable Mesoproterozoic crust also underpinned by thick lithospheric roots. The production of widespread thick and strong lithosphere via the process of orogenic thickening, possibly in several cycles, was fundamental to the eventual emergence of extensive continental landmasses-the cratons.
DS202201-0031
2021
Schaeffer, A.Pearson, G., Schaeffer, A., Stachel, T., Kjarsgaard, B., Grutter, H., Scott, J., Liu, J., Chacko, T., Smit, K.Revisiting the craton concept and its relevance for diamond exploration. *** See also Nature article previously listedGAC/MAC Meeting UWO, 1p. Abstract p. 238. Globalcratons

Abstract: The term craton has a complex and confused etymology. Despite originally specifying only strength and stability - of the crust - the term craton, within the context of diamond exploration, has widely come to refer to a region characterised by crustal basement older than 2.5 Ga, despite the fact that some such “cratons” no longer possess their deep lithospheric root. This definition often precluded regions with deep lithospheric roots but basement younger than 2-2.5 Ga. Viscous, buoyant lithospheric mantle roots are key to the survival and stability of continental crust. Here we use a revised craton definition (Pearson et al., 2021, in press), that includes the requirement of a deep (~150 km or greater) and intact lithospheric root, to re-examine the link between cratons and diamonds. The revised definition has a nominal requirement for tectonic stability since ~ 1 Ga and recognises that some regions are “modified cratons” - having lost their deep roots, i.e., they may have behaved like cratons for an extended period but subsequently lost much of their stabilising mantle roots during major tectono-thermal events. In other words, despite being long-lived features, cratons are not all permanent. The 150 km lithospheric thickness cut-off provides an optimal match to crustal terranes with 1 Ga timescale stability. In terms of regional diamond exploration, for a given area, the crucial criterion is when a deep mantle root was extant, i.e., over what period was the lithospheric geotherm suitable for diamond formation, stability and sampling? A thick lithospheric root is key to the formation of deep-seated magmas such as olivine lamproites and to the evolution of sub-lithospheric sourced proto-kimberlites, all capable of carrying and preserving diamonds to Earth's surface. This criterion appears essential even for sub-lithospheric diamonds, that still require a diamond transport mechanism capable of preserving the high-pressure carbon polymorph via facilitating rapid transport of volatile-charged magma to the surface, without dilution from additional melting that takes place beneath thinner (<120 km) lithospheric "lids". Seismology can help to define the lateral extent of today's cratons, but a detailed understanding of the regional geological history, kimberlite eruption ages and geothermal conditions is required to evaluate periods of past diamond potential, no-longer evident today. This revised craton concept broadens the target terranes for diamond exploration away from only the Archean cores of cratons and an associated mentality that "the exception proves the rule". The revised definition is compatible with numerous occurrences of diamond in Proterozoic terranes or Archean terranes underpinned by Proterozoic mantle.
DS201412-0776
2014
Schaeffer, A.J.Schaeffer, A.J., Lebedev, S.Imaging the North American continent using waveform inversion of global and USArray data.Earth and Planetary Science Letters, Vol. 402, pp. 26-41.United StatesGeophysics - seismics
DS201809-2093
2018
Schaeffer, A.J.Snyder, D.B., Schetselaar, E., Pilkington, M., Schaeffer, A.J.Resolution and uncertainty in lithospheric 3-D geological models. Canada MohoMineralogy and Petrology, doi.org/10.1007/ s00710-018-0619-2. 15p.MantleGeophysics

Abstract: As three-dimensional (3-D) modelling of the subcontinental mantle lithosphere is increasingly performed with ever more data and better methods, the robustness of such models is increasingly questioned. Resolution thresholds and uncertainty within deep multidisciplinary 3-D models based on geophysical observations exist at a minimum of three levels. Seismic waves and potential field measurements have inherent limitations in resolution related to their dominant wavelengths. Formal uncertainties can be assigned to grid-search type forward or inverse models of observable parameter sets. Both of these uncertainties are typically minor when compared to resolution limitations related to the density and shape of a specific observation array used in seismological or potential field surveys. Seismic wave source distribution additionally applies in seismology. A fourth, more complex level of uncertainty relates to joint inversions of multiple data sets. Using independent seismic wave phases or combining diverse methods provides another measure of uncertainty of particular physical properties. Extremely sparse xenolith suites provide the only direct correlation of rock type with observed or modelled physical properties at depths greater than a few kilometers. Here we present one case study of the Canadian Mohorovi?i? (Moho) discontinuity using only two data sets. Refracted and converted seismic waves form the primary determinations of the Moho depth, gravity field modeling provide a secondary constraint on lateral variations, the slope of the Moho, between the sparse seismic estimates. Although statistically marginal, the resulting co-kriged Moho surface correlates better with surface geology and is thus deemed superior.
DS201812-2807
2018
Schaeffer, A.J.Esteve, C., Schaeffer, A.J., Audet, P.Upper mantle structure underlying the diamondiferous Slave craton from teleseismic body-wave tomography.2018 Yellowknife Geoscience Forum , p.104-105. abstractCanada, Northwest Territoriestomography

Abstract: Cratons are, by definition, the most tectonically stable and oldest parts of the continental lithosphere on Earth. The Archean Slave craton is located in the northwestern part of the Canadian Shield. The propensity of diamondiferous kimberlite pipes in the central Slave craton raises many questions regarding their structural environment and source. Here, we provide the most robust teleseismic P and S body wave tomography models over the Slave craton region based on 20,547 P-wave delay times, 6,140 direct S-wave delay times and 3,381 SKS delay times. The P-wave model reveals an alternating pattern of relative positive and negative anomalies over a fine broad scale region within the central Slave craton. Furthermore, the P-wave model revealed two fine structures located in the lithosphere beneath the Lac de Gras kimberlite cluster, with relatively slow anomalies (B - C) that extend from 75 km to 350 km depths with an apparent dip to the north. These relatively slow P- and S-wave anomalies are associated with metasomatised regions within the lithosphere. The S-wave model displays a slow S-wave anomaly lying from 300 km depth to the transition zone beneath the central Slave craton. This anomaly is located beneath the Lac de Gras kimberlite cluster. We suggest that this anomaly is not the cause of the actual kimberlites at the surface since last eruption occurred 75-45 Ma ago but may be related to a potential kimberlite magma ascent in the asthenosphere.
DS201904-0732
2019
Schaeffer, A.J.Esteve, C., Schaeffer, A.J., Audet, P.Upper mantle structure underlying the diamondiferous Slave craton from teleseismic body-wave tomography. Lac de GrasTectonophysics, in press available, 27p.Canada, Northwest Territoriesgeophysics - seismics

Abstract: Cratons are, by definition, the most tectonically stable and oldest parts of the continental lithosphere on Earth. The Archean Slave craton is located in the northwestern part of the Canadian Shield. The propensity of diamondiferous kimberlite pipes in the central Slave craton raises many questions regarding their structural environment and source. Here, we provide the most robust teleseismic P and S body wave tomography models over the Slave craton region based on 20,547 P-wave delay times, 6,140 direct S-wave delay times and 3,381 SKS delay times. The P-wave model reveals an alternating pattern of relative positive and negative anomalies over a fine broad scale region within the central Slave craton. Furthermore, the P-wave model revealed two fine structures located in the lithosphere beneath the Lac de Gras kimberlite cluster, with relatively slow anomalies (B - C) that extend from 75 km to 350 km depths with an apparent dip to the north. These relatively slow P- and S-wave anomalies are associated with metasomatised regions within the lithosphere. The S-wave model displays a slow S-wave anomaly lying from 300 km depth to the transition zone beneath the central Slave craton. This anomaly is located beneath the Lac de Gras kimberlite cluster. We suggest that this anomaly is not the cause of the actual kimberlites at the surface since last eruption occurred 75-45 Ma ago but may be related to a potential kimberlite magma ascent in the asthenosphere.
DS202105-0774
2021
Schaeffer, A.J.Liu, J., Pearson, D.G., Wang, L.H., Mather, K.A., Kjarsgaard, B.A., Schaeffer, A.J., Irvine, G.J., Kopylova, M.G., Armstrong, J.P.Plume-driven recratonization of deep continental lithospheric mantle.Nature, doi.org/101038/ s41586-021-03395-5 5p. PdfCanada, Northwest Territoriescraton

Abstract: Cratons are Earth’s ancient continental land masses that remain stable for billions of years. The mantle roots of cratons are renowned as being long-lived, stable features of Earth’s continents, but there is also evidence of their disruption in the recent1,2,3,4,5,6 and more distant7,8,9 past. Despite periods of lithospheric thinning during the Proterozoic and Phanerozoic eons, the lithosphere beneath many cratons seems to always ‘heal’, returning to a thickness of 150 to 200 kilometres10,11,12; similar lithospheric thicknesses are thought to have existed since Archaean times3,13,14,15. Although numerous studies have focused on the mechanism for lithospheric destruction2,5,13,16,17,18,19, the mechanisms that recratonize the lithosphere beneath cratons and thus sustain them are not well understood. Here we study kimberlite-borne mantle xenoliths and seismology across a transect of the cratonic lithosphere of Arctic Canada, which includes a region affected by the Mackenzie plume event 1.27 billion years ago20. We demonstrate the important role of plume upwelling in the destruction and recratonization of roughly 200-kilometre-thick cratonic lithospheric mantle in the northern portion of the Slave craton. Using numerical modelling, we show how new, buoyant melt residues produced by the Mackenzie plume event are captured in a region of thinned lithosphere between two thick cratonic blocks. Our results identify a process by which cratons heal and return to their original lithospheric thickness after substantial disruption of their roots. This process may be widespread in the history of cratons and may contribute to how cratonic mantle becomes a patchwork of mantle peridotites of different age and origin.
DS2001-1026
2001
Schaeffer, N.Schaeffer, N., Manga, M.Interaction of rising and sinking mantle plumesGeophysical Research Letters, Vol. 28, No. 3, Feb. 1, pp.455-8.MantlePlumes, hotspots
DS1975-0629
1977
Schaeffer, S.Stauder, W., Kramer, M., Fischer, G., Schaeffer, S., Morrissey.Seismic Characteristics of Southeast Missouri As Indicated By a Regional Telemetered Microearthquake Array.Seismol. Soc. American Bulletin., Vol. 66, PP. 1953-1964.GlobalMid Continent
DS2003-0129
2003
Schaepman, M.Bojinski, S., Schaepman, M., Schlapfer, D., Itten, K.SPECCHIO: a spectrum database for remote sensing applicationsComputers and Geosciences, Vol. 29, 1, pp. 27-38.GlobalComputer - program, Not specific to diamonds
DS201112-0707
2011
Schaepman, T.R.Mulder, V.L., De Bruin, S., Schaepman, T.R., et al.The use of remote sensing in soil and terrain mapping - a review.Geoderma, Vol. 162, 1-2, pp. 1-19.TechnologySoils - review not specific to diamonds
DS202008-1462
2020
Schafer, C.Zubkova, N.V., Chukanov, N.V., Schafer, C., van Konstantin, V., Pekov,I.V., Pushcharovsky, D. Yu.Al analogue of chayvesite from a lamproite of Cancarix, SE Spain, and its crystal structure.Neues Jahbuch fur Mineralogie, Vol. 196, 3, pp. 193-196.Europe, Spainlamproite

Abstract: Al analogue of chayesite (with Al > Fe3+) was found in a lamproite from Cancarix, SE Spain. The mineral forms green thick-tabular crystals up to 0.4 mm across in cavities. The empirical formula derived from EMP measurements and calculated on the basis of 17 Mg + Fe + Al + Si apfu is (K0.75 Na0.20 Ca0.11)Mg3.04 Fe0.99 Al1.18 Si11.80 O30. The crystal structure was determined from single crystal X-ray diffraction data ( R = 2.38%). The mineral is hexagonal, space group P 6/ mcc, a = 10.09199(12), c = 14.35079(19) Å, V = 1265.78(3) Å3, Z = 2. Fe is predominantly divalent. Al is mainly distributed between the octahedral A site and the tetrahedral T 2 site. The crystal chemical formula derived from the structure refinement is C (K0.73 Na0.16 Ca0.11) B (Na0.02)4 A (Mg0.42 Al0.29 Fe0.29)2 T 2(Mg0.71 Fe0.16 Al0.13)3 T 1(Si0.985 Al0.015)12 O30.
DS2002-1412
2002
Schafer, F.N.Schafer, F.N., Foley, S.F.The effect of crystal orientation on wetting behaviour of silicate melts on surfaces spinel peridotitesContribution to Mineralogy and Petrology, Vol.143,pp.254-61., Vol.143,pp.254-61.MantleCrystal anisotropy - experimental petrology
DS2002-1413
2002
Schafer, F.N.Schafer, F.N., Foley, S.F.The effect of crystal orientation on wetting behaviour of silicate melts on surfaces spinel peridotitesContribution to Mineralogy and Petrology, Vol.143,pp.254-61., Vol.143,pp.254-61.MantleCrystal anisotropy - experimental petrology
DS1992-1336
1992
Schaffalitzky, C.Schaffalitzky, C.Recent developments on the classification of mineral reserves andresourcesGeological Society Special Publication, Case histories and methods in mineral, No. 63, pp. 33-36GlobalComputer, Ore reserves, geostatistics
DS1995-1664
1995
Schaffer, C.Schaffer, C., Dalrymple, J.Lands cape evolution in Roraima North Amazonia: Planation, paleosols andpaleoclimates.Zeit. Geomorphology, Vol. 39, No. 1, pp. 1-28.GlobalGeomorphology, Roraima
DS1995-1665
1995
Schaffer, C.Schaffer, C., Dalrymple, J.Lands cape evolution in Roraima, North Amazonia: planation, paleosols andpaleoclimatesZeitschrift f?r Geomorphologie, Vol. 39, No. 1, pp. 1-28Guyana, Venezuela, BrazilGeomorphology, Paleoclimates
DS202011-2047
2020
Schaffer, L.A.Kilgore, M.L., Peslier, A.H., Brandon, A.D., Schaffer, L.A., Morris, R.V., Graff, T.G., Agresti, D.G., O'Reilly, S.Y., Griffin, W.L., Pearson, D.G., Barry, K.G., Shaulis, J.Metasomatic control of hydrogen contents in the layered cratonic mantle lithosphere sampled by Lac de Gras xenoliths in the central Slave Craton, Canada.Geochimica et Cosmochimica Acta, Vol. 286, pp. 29-83. pdfCanada, Northwest Territoriesxenoliths

Abstract: Whether hydrogen incorporated in nominally anhydrous mantle minerals plays a role in the strength and longevity of the thick cratonic lithosphere is a matter of debate. In particular, the percolation of hydrogen-bearing melts and fluids could potentially add hydrogen to the mantle lithosphere, weaken its olivines (the dominant mineral in mantle peridotite), and cause delamination of the lithosphere's base. The influence of metasomatism on hydrogen contents of cratonic mantle minerals can be tested in mantle xenoliths from the Slave Craton (Canada) because they show extensive evidence for metasomatism of a layered cratonic mantle. Minerals from mantle xenoliths from the Diavik mine in the Lac de Gras kimberlite area located at the center of the Archean Slave craton were analyzed by FTIR for hydrogen contents. The 18 peridotites, two pyroxenites, one websterite and one wehrlite span an equilibration pressure range from 3.1 to 6.6 GPa and include samples from the shallow (?145?km), oxidized ultra-depleted layer; the deeper (?145-180?km), reduced less depleted layer; and an ultra-deep (?180?km) layer near the base of the lithosphere. Olivine, orthopyroxene, clinopyroxene and garnet from peridotites contain 30-145, 110-225, 105-285, 2-105?ppm H2O, respectively. Within each deep and ultra-deep layer, correlations of hydrogen contents in minerals and tracers of metasomatism (for example light over heavy rare-earth-element ratio (LREE/HREE), high-field-strength-element (HFSE) content with equilibration pressure) can be explained by a chromatographic process occurring during the percolation of kimberlite-like melts through garnet peridotite. The hydrogen content of peridotite minerals is controlled by the compositions of the evolving melt and of the minerals and by mineral/melt partition coefficients. At the beginning of the process, clinopyroxene scavenges most of the hydrogen and garnet most of the HFSE. As the melt evolves and becomes enriched in hydrogen and LREE, olivine and garnet start to incorporate hydrogen and pyroxenes become enriched in LREE. The hydrogen content of peridotite increases with decreasing depth, overall (e.g., from 75 to 138?ppm H2O in the deep peridotites). Effective viscosity calculated using olivine hydrogen content for the deepest xenoliths near the lithosphere-asthenosphere boundary overlaps with estimates of asthenospheric viscosities. These xenoliths cannot be representative of the overall cratonic root because the lack of viscosity contrast would have caused basal erosion of lithosphere. Instead, metasomatism must be confined in narrow zones channeling kimberlite melts through the lithosphere and from where xenoliths are preferentially sampled. Such localized metasomatism by hydrogen-bearing melts therefore does not necessarily result in delamination of the cratonic root.
DS201512-1981
2015
Schaffer, N.Van Wychen, W., Copland, L., Burgess, D.O., Gray, L., Schaffer, N., Fisher, T.Glacier velocities and dynamic discharge from the ice masses of Baffin Island and Bylot Island, Nunavut, Canada.Canadian Journal of Earth Sciences, Vol. 52, 11, pp. 980-989.Canada, Nunavut, Baffin IslandGeomorphology

Abstract: Speckle tracking of ALOS PALSAR fine beam data from 2007-2011 are used to determine the surface motion of major ice masses on Baffin Island and Bylot Island in the southern Canadian Arctic Archipelago. Glacier velocities are low overall, with peaks of ?100 m a?1 and means of ?20-60 m a?1 common along the main trunk of many outlet glaciers. Peak velocities on Penny and Bylot Island ice caps tend to occur near the mid-sections of their primary outlet glaciers, while the fastest velocities on all other glaciers usually occur near their termini due to relatively large accumulation areas draining through narrow outlets. Estimates of ice thickness at the fronts of tidewater-terminating glaciers are combined with the velocity measurements to determine a regional dynamic discharge rate of between ?17 Mt a?1 and ?108 Mt a?1, with a mid-point estimate of ?55 Mt a?1, revising downward previous approximations. These velocities can be used as inputs for glacier flow models, and provide a baseline dataset against which future changes in ice dynamics can be detected.
DS202008-1422
2020
Schaffer, R.V.McKensie, L., Kilgore, A.H., Peslier, A.D., Brandon, L.A., Schaffer, R.V., Graff, T.G., Agresti, D.G., O'Reilly, S.Y., Griffin, W.L., Pearson, D.G., Hangi, K., Shaulis, B.J.Metasomatic control of hydrogen contents in the layered cratonic mantle lithosphere sampled by Lac de Gras xenoliths in the central Slave craton, Canada.Geochimica et Cosmochimica Acta, in press available, doi.org/101016 /j.gca.2020.07.013 45p. PdfCanada, Northwest Territoriesdeposit - Lac de Gras

Abstract: Whether hydrogen incorporated in nominally anhydrous mantle minerals plays a role in the strength and longevity of the thick cratonic lithosphere is a matter of debate. In particular, the percolation of hydrogen-bearing melts and fluids could potentially add hydrogen to the mantle lithosphere, weaken its olivines (the dominant mineral in mantle peridotite), and cause delamination of the lithosphere's base. The influence of metasomatism on hydrogen contents of cratonic mantle minerals can be tested in mantle xenoliths from the Slave Craton (Canada) because they show extensive evidence for metasomatism of a layered cratonic mantle. Minerals from mantle xenoliths from the Diavik mine in the Lac de Gras kimberlite area located at the center of the Archean Slave craton were analyzed by FTIR for hydrogen contents. The 18 peridotites, two pyroxenites, one websterite and one wehrlite span an equilibration pressure range from 3.1 to 6.6 GPa and include samples from the shallow (? 145 km), oxidized ultra-depleted layer; the deeper (?145-180 km), reduced less depleted layer; and an ultra-deep (? 180 km) layer near the base of the lithosphere. Olivine, orthopyroxene, clinopyroxene and garnet from peridotites contain 30 - 145, 110 - 225, 105 - 285, 2 - 105 ppm H2O, respectively. Within each deep and ultra-deep layer, correlations of hydrogen contents in minerals and tracers of metasomatism (for example light over heavy rare-earth-element ratio (LREE/HREE), high-field-strength-element (HFSE) content with equilibration pressure) can be explained by a chromatographic process occurring during the percolation of kimberlite-like melts through garnet peridotite. The hydrogen content of peridotite minerals is controlled by the compositions of the evolving melt and of the minerals and by mineral/melt partition coefficients. At the beginning of the process, clinopyroxene scavenges most of the hydrogen and garnet most of the HFSE. As the melt evolves and becomes enriched in hydrogen and LREE, olivine and garnet start to incorporate hydrogen and pyroxenes become enriched in LREE. The hydrogen content of peridotite increases with decreasing depth, overall (e.g., from 75 to 138 ppm H2O in the deep peridotites). Effective viscosity calculated using olivine hydrogen content for the deepest xenoliths near the lithosphere-asthenosphere boundary overlaps with estimates of asthenospheric viscosities. These xenoliths cannot be representative of the overall cratonic root because the lack of viscosity contrast would have caused basal erosion of lithosphere. Instead, metasomatism must be confined in narrow zones channeling kimberlite melts through the lithosphere and from where xenoliths are preferentially sampled. Such localized metasomatism by hydrogen-bearing melts therefore does not necessarily result in delamination of the cratonic root.
DS1994-1535
1994
Schaidle, C.L.Schaidle, C.L.Earthmoving in the information ageAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint, Meeting held Albuquerque Feb. 14-17th, No. 94-48, 7pGlobalMining, Computer methodology
DS1960-1055
1968
Schairer, J.F.Yoder, H.S.JR., Schairer, J.F.The Melilite Plagioclase Incompatibility Dilemma in Igneousrocks.Carnegie Institute Yearbook, FOR 1968, PP. 101-105.GlobalResearch
DS1999-0117
1999
Schalamuk, B.Carrasquero, S.I., Canafoglia, M.E., Schalamuk, B.A hydrothermal event associated with the alkaline complex in Cerro Amambay, Paraguay.Stanley, SGA Fifth Biennial Symposium, pp. 627-30.GlobalAlkaline rocks
DS201212-0756
2012
Schall, R.Verster, A., De Waal, D., Schall, R., Prins, C.A truncated Pareto model to estimate the under recoveru of large diamonds.Mathematical Geosciences, Vol. 44, 1, pp. 91-100TechnologyRecovery
DS201606-1126
2012
Schall, R.Verster, A., de Waal, D., Schall, R., Prins, C.A truncated Pareto model to estimate the under recovery of large diamonds. Bayesian approach.Mathematical Geosciences, Vol. 44, 1, pp. 91-100.TechnologyMetallurgy process

Abstract: The metallurgical recovery processes in diamond mining may, under certain circumstances, cause an under-recovery of large diamonds. In order to predict high quantiles or tail probabilities we use a Bayesian approach to fit a truncated Generalized Pareto Type distribution to the tail of the data consisting of the weights of individual diamonds. Based on the estimated tail probability, the expected number of diamonds larger than a specified weight can be estimated. The difference between the expected and observed frequencies of diamond weights above an upper threshold provides an estimate of the number of diamonds lost during the recovery process.
DS1999-0627
1999
Schaller, M.Schaller, M., Steiner, O., Studer, I., Holzer, HerweghExhumation of Limpopo Central Zone granulites and dextral continent scale transcurrent movement...Precambrian Research, Vol. 96, No. 3-4. July, pp. 263-88.South AfricaPalala Shear Zone, Limpopo - tectonics
DS1910-0508
1916
Schaller, W.T.Schaller, W.T.Diamonds in the United States; 1915Mineral Resources of The United States For 1915, PT. 2, PP. 847-849.GlobalBlank
DS1910-0509
1916
Schaller, W.T.Schaller, W.T.Gems and Precious Stones: Diamond; 1915Mineral Resources of The United States For 1915: Part 2, Non, PP. 847-849.United StatesWest Coast
DS1910-0537
1917
Schaller, W.T.Schaller, W.T.Gems and Precious Stones: Diamond; 1916Mineral Resources of The United States For 1916: Part 2, Non, P. 894.United StatesGreat Lakes, West Coast
DS1920-0084
1921
Schaller, W.T.Schaller, W.T.Gems and Precious Stones. #2Mineral Resources For The Year 1918, PT. 2, PP. 7-14.California, West CoastDiamonds
DS1950-0043
1950
Schaller, W.T.Schaller, W.T.Miserite from Arkansaw- a Renaming of NatroxonotliteAmerican MINERALOGIST., Vol. 35, No. 9-10, PP. 911-921.United States, Gulf Coast, Arkansas, Garland CountyMineralogy
DS2002-1414
2002
Schaltegger, U.Schaltegger, U., Zeilinger, G., Frank, M., Burg, J.P.Multiple mantle sources during island arc magmatism. U Pb and Hf isotopic evidence from the Kohistan arc complex, Pakistan.Terra Nova, Vol. 14, 6, pp. 46-8.PakistanMagmatism - not specific to diamonds. Geochronology
DS200412-1380
2004
Schaltegger, U.Muntener, O., Pettke, T., Desmurs, L., Meier, M., Schaltegger, U.Refertilization of mantle peridotite in embryonic ocean basins: trace element and Nd isotopic evidence and implications to crustEarth and Planetary Science Letters, Vol. 221, 1-4, pp. 293-308.MantleGeochronology, melt
DS201610-1903
2016
Schaltegger, U.Reimink, J.R., Davies, J.H.F.L., Chacko, T., Stern, R.A., Heaman, L.M., Sarkar, C., Schaltegger, U., Creaser, R.A., Pearson, D.G.No evidence for Hadean continental crust within Earth's oldest evolved rock unit. (Acasta Gneiss Complex)Nature Geoscience, Vol. 9, pp. 777-780.CanadaHadean crust

Abstract: Due to the acute scarcity of very ancient rocks, the composition of Earth’s embryonic crust during the Hadean eon (>4.0 billion years ago) is a critical unknown in our search to understand how the earliest continents evolved. Whether the Hadean Earth was dominated by mafic-composition crust, similar to today’s oceanic crust1, 2, 3, 4, or included significant amounts of continental crust5, 6, 7, 8 remains an unsolved question that carries major implications for the earliest atmosphere, the origin of life, and the geochemical evolution of the crust-mantle system. Here we present new U-Pb and Hf isotope data on zircons from the only precisely dated Hadean rock unit on Earth—a 4,019.6 ± 1.8?Myr tonalitic gneiss unit in the Acasta Gneiss Complex, Canada. Combined zircon and whole-rock geochemical data from this ancient unit shows no indication of derivation from, or interaction with, older Hadean continental crust. Instead, the data provide the first direct evidence that the oldest known evolved crust on Earth was generated from an older ultramafic or mafic reservoir that probably surfaced the early Earth.
DS201612-2329
2016
Schaltegger, U.Reimink, J.R., Davies, J.H.F.L., Chacko, T., Stern, R.A., Heaman, L.M., Sarkar, C., Schaltegger, U., Creaser, R.A., Pearson, D.G.No evidence for Hadean continental crust within Earth's oldest evolved rock unit.Nature Geoscience, Vol. 9, pp. 777-780.CanadaAcasta Gneiss

Abstract: Due to the acute scarcity of very ancient rocks, the composition of Earth’s embryonic crust during the Hadean eon (>4.0 billion years ago) is a critical unknown in our search to understand how the earliest continents evolved. Whether the Hadean Earth was dominated by mafic-composition crust, similar to today’s oceanic crust1, 2, 3, 4, or included significant amounts of continental crust5, 6, 7, 8 remains an unsolved question that carries major implications for the earliest atmosphere, the origin of life, and the geochemical evolution of the crust-mantle system. Here we present new U-Pb and Hf isotope data on zircons from the only precisely dated Hadean rock unit on Earth—a 4,019.6 ± 1.8?Myr tonalitic gneiss unit in the Acasta Gneiss Complex, Canada. Combined zircon and whole-rock geochemical data from this ancient unit shows no indication of derivation from, or interaction with, older Hadean continental crust. Instead, the data provide the first direct evidence that the oldest known evolved crust on Earth was generated from an older ultramafic or mafic reservoir that probably surfaced the early Earth.
DS201810-2360
2018
Schaltegger, U.Nasdala, L., Corfu, F., Schoene, B., Tapster, S.R., Wall, C.J., Schmitz, M.D., Ovtcharova, M., Schaltegger, U., Kennedy, A.K., Kronz, A., Reiners, P.W., Yang, Y-H., Wu, F-Y., Gain, S.E.M., Griffin, W.L., Szymanowski, D., Chanmuang, C., Ende, N.M., ValleyGZ7 and GZ8 - two zircon reference materials for SIMS U-Pb geochronology.Geostandards and Geoanalytical Research, http://orchid.org/0000-0002-2701-4635 80p.Asia, Sri Lankageochronology

Abstract: Here we document a detailed characterization of two zircon gemstones, GZ7 and GZ8. Both stones had the same mass at 19.2 carats (3.84 g) each; both came from placer deposits in the Ratnapura district, Sri Lanka. The U-Pb data are in both cases concordant within the uncertainties of decay constants and yield weighted mean ²??Pb/²³?U ages (95% confidence uncertainty) of 530.26 Ma ± 0.05 Ma (GZ7) and 543.92 Ma ± 0.06 Ma (GZ8). Neither GZ7 nor GZ8 have been subjected to any gem enhancement by heating. Structure?related parameters correspond well with the calculated alpha doses of 1.48 × 10¹? g?¹ (GZ7) and 2.53 × 10¹? g?¹ (GZ8), respectively, and the (U-Th)/He ages of 438 Ma ± 3 Ma (2s) for GZ7 and 426 Ma ± 9 Ma (2s) for GZ8 are typical of unheated zircon from Sri Lanka. The mean U concentrations are 680 ?g g?¹ (GZ7) and 1305 ?g g?¹ (GZ8). The two zircon samples are proposed as reference materials for SIMS (secondary ion mass spectrometry) U-Pb geochronology. In addition, GZ7 (Ti concentration 25.08 ?g g?¹ ± 0.18 ?g g?¹; 95% confidence uncertainty) may prove useful as reference material for Ti?in?zircon temperature estimates.
DS2002-1415
2002
Schaltz, M.Schaltz, M., Resichmann, T., Tait, J., Bachtadse, V., Bahlburg, H., Martin, U.The Early Paleozoic break up of northern Gondwana, new paleomagnetic andInternational Journal of Earth Sciences, Vol. 91, No. 5, Oct. pp. 838-49.GermanyTectonics, Gondwana
DS1996-1561
1996
Schandelmeier, H.Worku, H., Schandelmeier, H.Tectonic evolution of the Neoproterozoic Adola belt of southern Ethiopia:evidence for a Wilson Cycle processPrecambrian Research, Vol. 77, No. 3-4, April pp. 179-210GlobalTectonics, Plate collision, Adola Belt
DS1997-1000
1997
Schandelmeir, H.Schandelmeir, H., Reynolds, P.O.Paleogeographic Paleotectonic atlas of north eastern Africa, Arabia and adjacent areas.Balkema, 160p. $ 168.00 United States not owned just referencedGlobalAtlas, Lineaments
DS1982-0541
1982
Schandl, E.S.Schandl, E.S., Clarke, D.B.Metasomatism in the Mantle Beneath Pipe 200, Northern LesothProceedings of Third International Kimberlite Conference, TERRA COGNITA, ABSTRACT VOLUME., Vol. 2, No. 3, PP. 265-266.LesothoKimberlite, Alteration
DS1989-1349
1989
Schandl, E.S.Schandl, E.S., O'Hanley, D.S., Wicks, F.J.Rodingites in serpentinized ultramafic rocks of the Abitibi Greenstonebelt, OntarioCanadian Mineralogist, Vol. 27, No. 4, December pp. 579-592OntarioGreenstone belt, Abitibi, ultramafics
DS1994-1536
1994
Schandl, E.S.Schandl, E.S., Gordton, M.P., Davis, D.W.Albitization at 1700 +- 2Ma in the Sudbury-Wanapitei Lake area:implications deep seated alkalic magmatismCanadian Journal of Earth Sciences, Vol. 31, No. 3, March pp. 597-607OntarioMagmatism, Alkaline
DS1995-0661
1995
Schandl, E.S.Gorton, M.P., Schandl, E.S.An unusual sink for rare earth elements: the rhyolite basalt contact of the Archean Winston Lake VMS..Economic Geology, Vol. 90, No. 7, November pp. 2065-72Ontariorare earth elements (REE), metamorphism, massive sulphide, copper, lead, zinc, Deposit -Winston Lake
DS201712-2713
2017
Schannor, M.Nicoli, G., Thomassot, E., Schannor, M., Vezinet, A., Jovovic, I.Constraining a Precambrian Wilson Cycle lifespan: an example from the ca. 1.8Ga Nagssugtoqidian Orogen, southeastern Greenland.Lithos, in press available 68p.Europe, GreenlandWilson cycle

Abstract: In the Phanerozoic, plate tectonic processes involve the fragmentation of the continental mass, extension and spreading of oceanic domains, subduction of the oceanic lithosphere and lateral shortening that culminate with continental collision (i.e. Wilson cycle). Unlike modern orogenic settings and despite the collection of evidence in the geological record, we lack information to identify such a sequence of events in the Precambrian. This is why it is particularly difficult to track plate tectonics back to 2.0 Ga and beyond. In this study, we aim to show that a multidisciplinary approach on a selected set of samples from a given orogeny can be used to place constraints on crustal evolution within a P-T-t-d-X space. We combine field geology, petrological observations, thermodynamic modelling (Theriak-Domino) and radiogenic (U-Pb, Lu-Hf) and stable isotopes (?18O) to quantify the duration of the different steps of a Wilson cycle. For the purpose of this study, we focus on the Proterozoic Nagssugtoqidian Orogenic Belt (NOB), in the Tasiilaq area, South-East Greenland. Our study reveals that the Nagssugtoqidian Orogen was the result of a complete three stages juvenile crust production (Xjuv) - recycling/reworking sequence: (I) During the 2.60-2.95 Ga period, the Neoarchean Skjoldungen Orogen remobilised basement lithologies formed at TDM 2.91 Ga with progressive increase of the discharge of reworked material (Xjuv from 75% to 50%; ?18O: 4-8.5‰). (II) After a period of crustal stabilization (2.35-2.60 Ga), discrete juvenile material inputs (?18O: 5-6‰) at TDM 2.35 Ga argue for the formation of an oceanic lithosphere and seafloor spreading over a period of ~ 0.2 Ga (Xjuv from < 25% to 70%). Lateral shortening is set to have started at ca. 2.05 Ga with the accretion of volcanic/magmatic arcs (i.e. Ammassalik Intrusive Complex) and by subduction of small oceanic domains (M1: 520 ± 60 °C at 6.6 ± 1.4 kbar). (III) Continental collision between the North Atlantic Craton and the Rae Craton occurred at 1.84-1.89 Ga. Crustal thickening of ~ 25 km was accompanied by regional metamorphism M2 (690 ± 20 °C at 6.25 ± 0.25 kbar) and remobilization of pre-existing supracrustal lithologies (Xjuv ~ 40%; ?18O: 5-10.5‰). Rates and durations obtained for seafloor spreading (175 ± 25 Ma), subduction (125 ± 75 Ma) and continental collision (ca. 60 Ma) are similar to those observed in Phanerozoic Wilson Cycle but differ from what was estimated for Archean terrains. Therefore, timespans of the different steps of a Wilson cycle might have progressively changed over time as a response to the progressive cratonization of the lithosphere.
DS201708-1572
2017
Schanofski, M.Hueck, M., Oriolo, S., Dunkl, I., Wemmer, K., Oyhantcabal, P., Schanofski, M., Stipp Basei, M.A., Siegesmund, S.Phanerozoic low temperature evolution of the Uruguayan shield along the South American passive margin.Journal of the Geological Society, Vol. 174, pp. 609-626.South America, Uruguaymagmatism

Abstract: The crystalline basement of Uruguay was assembled during the Brasiliano Orogeny in the Neoproterozoic Era and was later affected by discrete tectonic activity. A new multi-method low-temperature dataset including (U–Th)/He ages from both zircon and apatite, T–t modelling and K–Ar dating of fine sericite fractions and fault gouge reveal a detailed post-orogenic geological history spanning the Phanerozoic Eon. The juxtaposition of the terranes that compose the area was achieved in the Ediacaran Period, and post-collision was marked by intense exhumation, in which the crystalline basement reached near-surface conditions by the early to mid-Palaeozoic. Regional subsidence promoted sedimentation in the Paraná Basin until the Permian, covering and reheating much of the basement that is at present exposed. Afterwards, deposition and volcanism were mostly confined to its current limits. Regional exhumation of the shield during the Permo-Triassic exposed much of the northern portion of the basement, and the south was further affected by the opening of the South Atlantic Ocean during the Mesozoic. Little exhumation affected the Uruguayan Shield during the Cenozoic, as reflected in its modest topography. The reactivation of inherited Neoproterozoic structures influenced the development of Mesozoic basins and the present-day landscape.
DS1994-1537
1994
Schantz, R.Jr.Schantz, R.Jr.Purpose and effects of a royalty on public land mineralsResources Policy, Vol. 20, No. 1, March pp. 35-48GlobalEconomics, Legal -royalty taxes
DS1991-0940
1991
Scharber, H.G.Kurat, G., Embeyisz.., A., Kracher, A., Scharber, H.G.The upper mantle beneath Kapenstein and the Transdanubian volcanic E. Austria and W. Hungary - a comparisonMineral. Petrol, Vol. 44, No. 1-2, pp. 21-38Austria, HungaryMantle, Volcanics
DS201904-0735
2019
Schardong, L.Ferreira, A.M.G., Faccenda, M., Sturgeon, W., Chang, S-J., Schardong, L.Ubiquitous lower mantle anisotropy beneath subduction zones.Nature Geoscience, Vol. 32, pp. 301-306.Mantlesubduction

Abstract: Seismic anisotropy provides key information to map the trajectories of mantle flow and understand the evolution of our planet. While the presence of anisotropy in the uppermost mantle is well established, the existence and nature of anisotropy in the transition zone and uppermost lower mantle are still debated. Here we use three-dimensional global seismic tomography images based on a large dataset that is sensitive to this region to show the ubiquitous presence of anisotropy in the lower mantle beneath subduction zones. Whereas above the 660?km seismic discontinuity slabs are associated with fast SV anomalies up to about 3%, in the lower mantle fast SH anomalies of about 2% persist near slabs down to about 1,000-1,200?km. These observations are consistent with 3D numerical models of deformation from subducting slabs and the associated lattice-preferred orientation of bridgmanite produced in the dislocation creep regime in areas subjected to high stresses. This study provides evidence that dislocation creep may be active in the Earth’s lower mantle, providing new constraints on the debated nature of deformation in this key, but inaccessible, component of the deep Earth.
DS1991-1481
1991
ScharerRyan, B., Krogh, T.E., Heaman, Scharer, PhillipeOn recent geochronological studies in the Nain Province Churchill province and Plutonic Suite.Newfound. Geological Survey, Paper 91-1, pp. 257-61.Quebec, Labrador, UngavaNain Plutonic suite, Geochronology
DS2003-0858
2003
ScharerMacouin, M., Valet, J.P., Besse, J., Buchan, K., Ernst, R., Le Goff, M., ScharerLow paleointensities recorded in 1 to 2.4. Ga Proterozoic dykes, Superior ProvinceEarth and Planetary Science Letters, Vol. 213, 1-2, pp. 79-95.Ontario, ManitobaGeochronology
DS1988-0613
1988
Scharer, U.Scharer, U., Krogh, T.E., Wardle, Ryan, Gandhiuranium-lead (U-Pb) ages of early to middle Proterozoic volcanism and metamorphism in the Makkovik Orogen, Labrador.Canadian Journal of Earth Sciences, Vol. 25, pp. 1098-1107.LabradorGeochronology
DS1992-1337
1992
Scharer, U.Scharer, U., Corfu, F., Demaiffe, D.Heterogeneity of the subcontinental mantle: uranium-lead (U-Pb) (U-Pb) and Lu-Hf in megacrysts of baddeleyite and zircon from the Mbuji-Mayi kimberliteEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p.339Central AfricaMbuji-Mayi kimberlite, Mantle
DS1993-1232
1993
Scharer, U.Philippe, S., Wardle., R.J., Scharer, U.Labradorian and Grenvillian crustal evolution of the Goose Bay region, Labrador and geochronological...Canadian Journal of Earth Sciences, Vol. 30, pp. 2315-2.Labrador, QuebecGeochronology
DS1995-1607
1995
Scharer, U.Romer, R.L., Scharer, U., Wardle, Wiltonuranium-lead (U-Pb) age of the Seal lake Group, Labrador: relationship to Mesoproterozoic extension related magmatism...Canadian Journal of Earth Sciences, Vol. 32, pp. 1401-10.Quebec, Labrador, UngavaLaurasia - magmatism, Seal lake Group
DS1997-1001
1997
Scharer, U.Scharer, U., Corfu, F., Demaiffe, D.uranium-lead (U-Pb) and Lu Hafnium isotopes in baddeleyite and zircon megacrysts from the Mbuji Mayi kimberlite: mantleChemical Geol., Vol. 143, No. 1-2, Nov. 17, pp. 1-16.Democratic Republic of CongoSubcontinental mantle, Geochronology
DS1999-0208
1999
Scharer, U.Faure, M., Lin, W., Shu, L., Scharer, U.Tectonics of the Dabie Shan and possible exhumation mechanisms of ultra high pressure rocks.Terra Nova, Vol. 11, No. 6, Dec. pp. 251-8.China, easternTectonics, ultra high pressure (UHP)
DS2000-0284
2000
Scharer, U.Faure, M., Lin, W., Scharer, U.Tectonics of the Dabie Shan (eastern China) and possible exhumation mechanism of ultra high pressure ..Terra Nova, Vol. 11, No. 6, pp. 251-65.China, eastern Chinaultra high pressure (UHP) - Dabie Shan, Tectonics
DS2000-0489
2000
Scharer, U.Kerschhofer, L., Scharer, U., Deutsch, A.Evidence for crystals from the lower mantle: baddeleyite megacrysts of the Mbuiji Mayi kimberlite.Earth and Planetary Science Letters, Vol. 179, No. 2, Jun. 10, pp. 219-26.TanzaniaMineral chemistry, Deposit - Mbuji Mayi
DS2000-0864
2000
Scharer, U.Scharer, U., Girardeau, J., Cornen, G., Boillot, G.138-121 Ma asthenospheric magmatism prior continental breakup in the North Atlantic geodynamic implications.Earth and Planetary Science Letters, Vol.181, No.4, Sept.30, pp.555-72.GlobalMagmatism, Tectonics - rifting, continental margin
DS2002-1399
2002
Scharer, U.Santos, J.F., Scharer, U., Ibarguchi, J.I.G., GirardeauGenesis of pyroxenite rich peridotite at Cabo Ortegal : geochemical and Pb Sr Nd isotope data.Journal of Petrology, Vol. 43, No. 1, pp. 17-44.SpainPyroxenite, lead, strontium, neodynium, Petrology
DS2003-0396
2003
Scharer, U.Faure, M., Lin, W., Scharer, U., Shu, L., Sun, Y., Arnaud, N.Continental subduction and exhumation of UHP rocks. Structural and geochronologicalLithos, Vol. 70, 3-4, pp. 213-41.ChinaUHP, geochronology
DS2003-1218
2003
Scharer, U.Scharer, U., Labrousse, L.Dating the exhumation of UHP rocks and associated crustal melting in the NorwegianContributions to Mineralogy and Petrology, Vol. 144, 6, pp. 758-70.NorwayGeochronology, UHP
DS2003-1219
2003
Scharer, U.Scharer, U., Labrousse, L.Dating the exhumation of UHP rocks and associated crustal melting in the NorwegianContributions to Mineralogy and Petrology, Vol. 144, 6, March pp. 758-77.NorwayUHP - ultra high pressure, Geochronology
DS200412-0538
2003
Scharer, U.Faure, M., Lin, W., Scharer, U., Shu, L., Sun, Y., Arnaud, N.Continental subduction and exhumation of UHP rocks. Structural and geochronological insights from the Dabie Shan, East China.Lithos, Vol. 70, 3-4, pp. 213-41.ChinaUHP, geochronology
DS200412-1193
2003
Scharer, U.Macouin, M., Valet, J.P., Besse, J., Buchan, K., Ernst, R., Le Goff, M., Scharer, U.Low paleointensities recorded in 1 to 2.4. Ga Proterozoic dykes, Superior Province, Canada.Earth and Planetary Science Letters, Vol. 213, 1-2, pp. 79-95.Canada, Ontario, ManitobaGeochronology
DS200412-1741
2003
Scharer, U.Scharer, U., Labrousse, L.Dating the exhumation of UHP rocks and associated crustal melting in the Norwegian Caledonides.Contributions to Mineralogy and Petrology, Vol. 144, 6, pp. 758-70.Europe, NorwayGeochronology, UHP
DS200712-0496
2007
Scharer, U.Jourdan,F., Bertrand, H., Scharer, U., Blichert-Toft, J., Feraud, G., Kampunzu, A.B.Major and trace element and Sr Nd, Hf, and Pb isotope compositions of the Karoo large igneous province, Botswana and Zimbabwe: lithosphere vs mantle plume...Journal of Petrology, Vol. 48, 6, pp. 1043-1078.Africa, Botswana, ZimbabweGeochemistry, geochronology
DS201112-0920
2011
Scharer, U.Scharer, U., Berndt, J., Deutsch, A.The genesis of deep mantle xenocrystic zircon and baddeleyite megacrysts ( Mbuji-Mayi kimberlite): trace element patterns.European Journal of Mineralogy, Vol. 23, 2, pp. 241-255.Africa, Democratic Republic of CongoChemistry
DS201312-0782
2013
Scharf, T.E.Scharf, T.E.Strong rocks sustain ancient postorogenic topography in southern Africa.Geology, Vol. 41, 3, pp. 331-4.AfricaTectonics
DS1992-1115
1992
Scharmova, M.Nemec, D., Scharmova, M.Argentopentlandite in olivine minette near Horni Kozli, southern BohemiaCasopis pre mineralogii a geologii, article is in ENGLISH, Vol. 37, No. 4, pp. 325-328.GlobalMinette
DS1960-1208
1969
Scharon, L.Scharon, L., Hsu, I-CHI.Paleomagnetic Investigations of Some Arkansaw Alkalic Igneous Rocks.Journal of Geophysical Research, Vol. 74, No. 10, PP. 2774-2779.United States, Gulf Coast, Arkansas, Hot Spring CountyAbsolute Age
DS201012-0669
2010
Schatz, H.Schatz, H.The evolution of elements and isotopes.Elements, Vol. 6, pp. 13-17.MantleGeochronology
DS200712-0680
2006
Schatzlein, D.Mariano, A.N., Schatzlein, D.Rapid in field identification of rare earth elements (REE) using field portable XRF.The Gangue, GAC, MDD, CIM newsletter, No.89, April, pp. 1, 8-11.Canada, Northwest TerritoriesThor Lake area, technology REE
DS200912-0841
2009
Schauble, E.Young, E.D., Tonui, E., Manning, C.E., Schauble, E., Macris, C.A.Spinel olivine magnesium isotope thermometry in the mantle and implications for the MG isotopic composition of Earth.Earth and Planetary Science Letters, Vol. 288, 3-4, pp. 524-533.MantleGeothermometry
DS201012-0881
2009
Schauble, E.Young, E.D., Tonui, E., Manning, C.E., Schauble, E., Macris, C.A.Spinel olivine magnesium isotope thermometry in the mantle and implications for the Mg isotopic composition of Earth.Earth and Planetary Science Letters, Vol. 288, pp. 524-533..MantleGeochemistry
DS201412-0220
2014
Schauble, E.A.Eiler, J.M., Berquist, B., Bourg, I., Cartigny, P., Farquhar, J., Gagnon, A., Guo, W., Halevy, I., Hofman, A., larson, T.E., Levin, N., Schauble, E.A., Stolper, D.Frontiers of stable isotope geoscience.Chemical Geology, Vol. 372, pp. 119-143.TechnologyReview of isotopes
DS1900-0037
1900
Schauf, W.Schauf, W.Ueber den DiamantenSenk. Naturf. Ges. Berichte., PP. CXXXV-CXXXVI.Africa, South AfricaDiamond Occurrences
DS1985-0590
1985
Schawrz, E.J.Schawrz, E.J., Buchan, K.L.Post Aphebian uplift deduced from remanent magnetization, Yellowknife Area of Slave Province.Canadian Journal of Earth Sciences, Vol. 22, pp. 1793-1802.Northwest TerritoriesTectonics
DS200812-0475
2007
Scheck-Wenderoth, M.Hirsch, K.K., Scheck-Wenderoth, M., Paton, D.A., Bauer, K.Crustal structure beneath the Orange Basin, South Africa.South African Journal of Geology, Vol. 110, 2-3, Sept. pp. 249-260.Africa, South AfricaTectonics
DS200812-0571
2008
Scheck-Wenderoth, M.Kirsch, K.K., Bauer, K., Scheck-Wenderoth, M.Deep structure of the western South African passive margin results of a combined approach of seismic, gravity and isostatic investigations.Tectonophysics, In press available 58p.Africa, South AfricaDeposit - Orange
DS1993-0579
1993
Scheepers, R.Gresse, P.G., Scheepers, R.Neoproterozoic to Cambrian (Namibian) rocks of South Africa: a geochronological and geotectonic reviewJournal of African Earth Sciences, Vol. 16, No. 4, pp. 375-393South AfricaGeochronology, Tectonics
DS201412-0341
2014
Scheepers, R.Harris, C., Hlongwane, W., Gule, N., Scheepers, R.Origin of tanzanite and associated gemstone mineralization at Merlani, Tanzania.Journal of South African Geology, Vol. 117, 1, June pp. 15-30.Africa, TanzaniaTanzanite
DS1991-1511
1991
Scheffer, V.Scheffer, V.The shaping of environmentalism in AmericaUniversity of of Washington Press, 260p. approx. 25.00 United StatesGlobalEnvironmental, Book -ad
DS1994-1661
1994
Scheglov, A.D.Sokolov, A.L., Viljoen, R.P., Scheglov, A.D.Mineral provinces and tectonic regimes: ancient platforms, mobile belts and zones of tectonic-magmaticExploration and Mining Geology, Vol. 3, No. 4, Oct. pp. 315-328South Africa, RussiaMetallogeny -overview, Tectonics, belts, zones
DS1992-0899
1992
Schehnhuber, H.J.Krumbein, W.E., Schehnhuber, H.J.Geophysiology of mineral deposits - a model for a biologically driving force of global changes through earth historyTerra Nova, Global Change Special Issue, Vol. 4, pp. 351-362GlobalGlobal Change, Mineral deposits
DS1970-0985
1974
Scheibe, E.A.Scheibe, E.A.Der Grosse Brukkaros in SuedwestafrikaSth. West Afr. Scien. Soc. Journal, Vol. 28, PP. 19-33.Southwest Africa, NamibiaCarbonatite
DS1975-0860
1978
Scheibe, L.F.Scheibe, L.F.Fazenda Varela Carbonatite, Lajes, Santa Catarina, BrasilI Symposio International De Carbonatitos, PP. 137-146.BrazilPetrology
DS1985-0591
1985
Scheibe, L.F.Scheibe, L.F.Contribution to the geochronology of the Lages alkaline complex, state of Santa Catarina, BrasilNational Technical Information Service DE 87701291/WNR., 9p. $ 9.95USBrazilCarbonatite, Geochronology
DS1900-0214
1903
Scheibe, R.Scheibe, R.Der Blaugrund im Deutsch SuedwestafrikaDeut. Kolon. Zeitung, Vol. 11, PP. 211-212.Africa, Namibia, JerusalemMineralogy, Kimberlite
DS1900-0449
1906
Scheibe, R.Scheibe, R.Der Blau Grund des D.s.w.a. im Vergleich Mit Dem des Englischen S.a.Progr. Kgl. Bergak (berlin), C. Feisler Publishing, 18P.Africa, Namibia, South Africa, JerusalemMineralogy, Kimberley, Janlib
DS1900-0450
1906
Scheibe, R.Scheibe, R.Diamantmuttergestein in Deutsch SuedwestafrikaDeutsch. Kolonbl., Vol. 17, No. 10, PP. 312-313.Africa, NamibiaDiamond
DS1910-0094
1910
Scheibe, R.Scheibe, R.Das Luderitzbuchter Diamanten-gebietDeut. Kolon. Zeitung, Southwest Africa, NamibiaDiamond Occurrence
DS1910-0095
1910
Scheibe, R.Scheibe, R.Natur und Aussehen der Diamant felder in D.s.w.a. das Vorkommen der Diamanten und des Blue grounds Deutsch Suedwest afrikas in Geologischer Hinsicht.Verh. D. Dritten Deuts., PP. 33-38.Southwest Africa, NamibiaMineralogy, Diamond Occurrences, Kimberlite
DS1910-0211
1911
Scheibe, R.Scheibe, R.Art und Bedeutung des Diamantvorkommens in SuedwestafrikaNaturw. Wschr., N.F. Vol. 10, No. 29, PP. 457-459.Southwest Africa, NamibiaDiamond, Mining Methods
DS1910-0376
1913
Scheibe, R.Scheibe, R.Diamant. die Nutzbaren MineralienStuttgart: Dammer-tietze., GlobalMineralogy, Kimberley, Janlib
DS1910-0377
1913
Scheibe, R.Scheibe, R.Diamant, 1913Die Nutzbaren Mineralien, Dammer-tietze, Ed., PP. 1-56.Southwest Africa, NamibiaDiamond Occurrences, Mineralogy, Kimberley
DS201510-1802
2015
Scheiber-Enslin, S.E.Scheiber-Enslin, S.E., Ebbing, J., Webb, S.J.New depth maps of the main Karoo basin, used to explore the Cape isostatic anomaly, South Africa.South African Journal of Geology, Vol. 118, 3, pp. 225-248.Africa, South AfricaGeophysics - seismics

Abstract: Here we present a comprehensive depth and thickness map of the main Karoo and Cape Basins using borehole and reflection seismic data. The depth to the Whitehill Formation, which is the focus of current shale gas interest within the Karoo, is also mapped. Change: The deepest part of the basin is in the south, along the northern boundary of the Cape Fold Belt (~4000 m in the southwest Karoo and ~5000 m in the southeast; ~5500 to 6000 m sediment thickness). The Whitehill Formation along this boundary reaches a depth of ~3000 m in the southwest and ~4000 m in the southeast. Limited borehole data in the southeastern Karoo show a broad deepening of the basin here compared to the southwestern Karoo. In the southeast near East London faulting has resulted in deepening of the basin close to the coast, with the Whitehill Formation deepening to over ~5000 km. Seismic and borehole data show that the Cape Supergroup pinches out below the Karoo Basin around Beaufort West and Graaff-Reinet in the southern Karoo (32.6°S for the Bokkeveld and 32.4°S for the Table Mountain Group). The Cape Supergroup reaches thicknesses of around 4 km in the south. The gravity effect of these sediments does not account for the Cape Isostatic Anomaly (CIA) in the southern part of the Karoo Basin near Willowmore and Steytlerville, i.e., an ~45 mGal Bouguer gravity low. A refraction seismic profile over the anomaly shows this region is associated with a large volume of low velocity/density shallow sediments (4.5 m/s2, 2500 kg/m3), as well as a low velocity/density anomaly associated with a normal fault and the Klein Winterhoek Thrust Fault (5.5 m/s2, 2650 kg/m3). These low density shallow sediments are explained by uplift of Karoo and Cape sediments of ~2 km or greater that is evident on Soekor reflection seismic data. This deformation has brought lower density shales (1800 to 2650 kg/m3) of the Ecca Group closer to the surface. These shallower features along with a deeper lower crust in this region (6.5 m/s2, 2900 kg/m3) are interpreted to account for the CIA.
DS1990-1308
1990
Scheibner, E.Scheibner, E.The tectonics of New South Wales in the second decade of application of the plate tectonics paradigM.Journal of Proceedings of the Royal Soc. New South Wales, Vol. 122, pp. 35-74AustraliaTectonics, Plate tectonics
DS1997-1203
1997
Scheibner, E.Veevers, J.J., Walter, M.R., Scheibner, E.Neoproterozoic tectonics of Australia- Antarctica and Laurentia and the 560Ma birth of Pacific Ocean ...Journal of Geology, Vol. 105, No. 2, March pp. 225-242.GlobalPangean supercycle, Tectonics
DS1989-1350
1989
Scheidegger, A.E.Scheidegger, A.E., Schubert, C.Neotectonic provinces and joint orientations of northern South AmericaJournal of South American Earth Sciences, Vol. 2, No. 4, pp. 331-342South AmericaTectonics, Structure-joints
DS200412-1742
2004
Scheidegger, A.E.Scheidegger, A.E.Book Review of Global wrench tectonics.Earth Science Reviews, Vol. 67, 1-2, pp. 157-158.GlobalBook - review
DS1975-0402
1976
Scheidl, L.G.Scheidl, L.G.Die Wirtschaft der Republik Suedafrika; Eine Geographische Untersuching.Wiener Geographische Schriften., No. 41-42, 169P.South AfricaGeography, Kimberley, Mining
DS1993-1386
1993
Scheiner, B.J.Scheiner, B.J., Stanley, D.A., Karr, C.L.Emerging computer techniques for the minerals industrySociety for Mining, Metallurgy and Exploration (SME), American Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Publication, 400p. approx. $ 65.00GlobalBook -table of contents, Computer techniques
DS1995-1666
1995
Scheiner, B.J.Scheiner, B.J.New remediation technology in the changing environmental arenaSociety for Mining, Metallurgy and Exploration (SME)/American Institute of Mining, Metallurgical, and Petroleum Engineers, 234p. approx. $ 53.00 United StatesUnited StatesBook -ad, Remediation technology
DS1996-0914
1996
Scheiner, B.J.McClelland, G.E., Scheiner, B.J., Muhtadi, O., Keane, J.Practical aspects of international management and processingSociety of Mining Engineers, 118p. see pricesUnited StatesBook -ad, Mining -practical processing
DS1991-1028
1991
Scheirer, D.S.Macdonald, K.C., Scheirer, D.S., Carbote, S.M.Mid-ocean ridges: discontinuities, segments and giant cracksScience, Vol. 253, August 30, pp. 986-994GlobalTectonics, Mid-ocean ridges
DS1993-0945
1993
Scheirer, D.S.Macdonald, K.C., Scheirer, D.S., Carbotte, S.It's only topography: part 1Gsa Today, Vol. 3, No. 1, January p. 1, 24, 25GlobalSonar mapping systems, Ridges, offsets, tectonics, structure
DS2002-1296
2002
Scheirer, D.S.Raddick, M.J., Parmentier, E.M., Scheirer, D.S.Buoyant decompression melting: a possible mechanism for intraplate volcanismJournal of Geophysical Research, Oct. 29, 10.1029/2001JB000617.MantleMelting, Magmatism
DS200412-1743
2004
Schellart, W.P.Schellart, W.P.Quantifying the net slab pull force as a driving mechanism for plate tectonics.Geophysical Research Letters, Vol. 31, 7, April 16, 10.1029/2004 GLO19528MantleSubduction
DS200412-1744
2004
Schellart, W.P.Schellart, W.P.Kinematics of subduction and subduction induced flow in the upper mantle.Journal of Geophysical Research, Vol. 109, B7, 10.1029/2004 JB002970MantleSubduction
DS200512-0939
2005
Schellart, W.P.Schellart, W.P.Influence of the subducting plate velocity on the geometry of the slab and migration of the subduction hinge.Earth and Planetary Science Letters, Vol. 231, 3-4, March 15, pp. 197-219.AsiaGeodynamics, subduction
DS200612-1233
2006
Schellart, W.P.Schellart, W.P., Freeman, J., Stegman, D.R.Subduction induced mantle convection on Earth: poloidal versus toroidal flow.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 10, abstract only.MantleSubduction
DS200612-1370
2006
Schellart, W.P.Stegman, D.R., Freeman, J., Schellart, W.P., Moresi, L.N., May, D.Evolution and dynamics of subduction zones from 4-D geodynamic models.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 58. abstract only.MantleSubduction
DS200812-1014
2008
Schellart, W.P.Schellart, W.P., Stegman, D.R., Freeman, J.Global trench migration velocities and slab migration induced upper mantle volume fluxes: constraints to find an Earth reference frame based on minimizing viscous dissipation.Earth Science Reviews, Vol. 88, 1-2, May pp. 118-144.MantlePlate tectonics - subduction, convection, hotspot
DS200912-0672
2009
Schellart, W.P.Schellart, W.P.Evolution of the slab bending radius and the bending dissipation in three dimensional subduction models with a variable slab to upper mantle viscosity ratio.Earth and Planetary Science Letters, Vol. 288, 1-2, pp. 309-319.MantleSubduction
DS201012-0670
2010
Schellart, W.P.Schellart, W.P.Evolution of subduction zone curvature and its dependence on the trench velocity and the slab to upper mantle viscosity ratio.Journal of Geophysical Research, Vol. 115, B 11, B11406.MantleSubduction
DS201112-0921
2011
Schellart, W.P.Schellart, W.P., Stegman, D.R., Farrington, R.J., Moresi, L.Influence of lateral slab edge distance on plate velocity, trench velocity, and subduction partitioning.Journal of Geophysical Research, Vol. 116, B10, B10408.MantleSubduction
DS201312-0590
2013
Schellart, W.P.May, D.A., Schellart, W.P., Moresi, L.Overview of adaptive finite element analysis in computational geodynamics.Journal of Geodynamics, Vol. 70, Oct. pp. 1-20.TechnologyGeodynamic program
DS201507-0310
2015
Schellart, W.P.Edwards, S.J., Schellart, W.P., Duarte, J.C.Geodynamic models of continental subduction and obduction of overriding plate forearc oceanic lithosphere on top of continental crust.Tectonics, Vol. 34, 7, pp. 1494-1515.New ZealandSubduction
DS201611-2101
2016
Schellart, W.P.Chen, Z., Schellart, W.P., Strak, V., Duarte, J.C.Does subduction induced mantle flow drive backarc extension?Earth and Planetary Science Letters, Vol. 441, pp. 200-210.MantleSubduction

Abstract: Subduction zones are one of the most striking feature on Earth. They represent one of the two types of convergent plate boundaries, in which one tectonic plates sinks underneath another into the Earth’s mantle. Soon after the advent of the theory of plate tectonics scientists recognized that subduction zones are one of the main drivers of plate motion and mantle convection [Elsasser, 1971]. With trench motion during progressive subduction, overriding plates incorporated in subduction zones may follow the trench and/or deform internally. Such deformation is often characterized by backarc extension, which leads to opening of backarc basins, such as the Tyrrhenian Sea, the Scotia Sea, the Aegean Sea, the North Fiji Basin, and the Lau Basin.
DS1994-1107
1994
Schellmann, W.Marker, A., de Oliviera, J.J., Schellmann, W.Lithodependence of partly transported weathering horizons above a migmatite diabase contact in Central Bahia State, BrasilCatena, Laterization and Supergene Ore, Vol. 21, No. 2-3, pp. 215-227BrazilDiabase dike, Laterization
DS1994-1538
1994
Schellmann, W.Schellmann, W.Geochemical differentiation in laterite and bauxite formationCatena, Special Issue on Laterization Processes and Supergene Ore, Vol. 21, No. 2-3, pp. 131-144Australia, IndiaGeochemistry, Laterization - bauxite
DS1995-1667
1995
Schellmann, W.Schellmann, W.Microprobe analysis of the Al-iron-Si variations in lateritesChem. Erde, Vol. 55, pp. 97-108Uganda, GhanaAnalyses -microprobe, Laterites
DS200412-1745
2004
Schena, G.Schena, G., Favretto, S., Santoro, L., Pasini, A., Bettuzzi, M., Casali, F., Mancini, L.Detecting microdiamonds in kimberlite drill hole cores by computed tomography.International Journal of Mineral Processing, 16p.TechnologyMineral processing - microdiamonds
DS1991-1512
1991
Schena, G.D.Schena, G.D., Bevilacqua, P., Gochin, R.J.Refinements of model of economic evaluation of preconcentrationTransactions of the Institute of Mining and Metallurgy (IMM), Sect. C., Jan-April pp. C57-C61GlobalMineral processing, Economics
DS1992-1338
1992
Schena, G.D.Schena, G.D., Gochin, R.J., Spencer, R.Assessing impact of a mineral project on the economy of a developing country -part 1: input-output modelsInstitute of Mining and Metallurgy (IMM) Transactions, Vol. 101, pp. A 29-A35GlobalEconomics, ore reserves, Ranking mineral projects
DS1992-1339
1992
Schena, G.D.Schena, G.D., Gochin, R.J., Spencer, R.Assessing impact of a mineral project on the economy of a developing country- part 2: cost /benefit analysisTransactions of the Institute of Mining and Metallurgy (IMM), Vol. 100, pp. A181-A188NamibiaEconomics, Diamond mining mentioned
DS1993-1387
1993
Schena, G.D.Schena, G.D.Economy wide impact of a mineral project in a developing country: a graphicillustrationJournal South African Mining Metallurgy, Vol. 93, No. 11/12, pp. 277-291South AfricaEconomics, Mineral project -development
DS1860-0524
1886
Schenck, A.Schenck, A.Das Gebiet Zurschen Angra Peguena und BethenienZeits. Deuts. Geol. Ges., Vol. 37, PP. 236-241.Africa, Southwest Africa, NamibiaTravelogue, History
DS1860-0813
1893
Schenck, A.Schenck, A.Gebirgsbau und Bodengestaltung von Deutsch Sued West AfrikaVerh. Deuts. Geograph. Tagen., 10TH. MEETING PP. 155-172.Africa, Southwest Africa, NamibiaTravelogue, Geology
DS1900-0077
1901
Schenck, A.Schenck, A.Ueber Den Geitse' Gubib, Einen Porphryischen Stratovulkan Deutsch-suedwest Afrikas.Zeitschr. Deut. Geol. Ges., Vol. 53, PP. 54-55. ALSO: ZEITSCHR. F. PRAKT. GEOL., P. 419.Africa, NamibiaCarbonatite, Impact Structure, Kimberlite
DS1900-0078
1901
Schenck, A.Schenck, A.Deutsch Sued West Afrika im Vergleich Zum Aebrigen Sued Afrika.Verhandl. Deuts. Geograph. Tagen., 13TH. MEETING PP. 154-156.Africa, NamibiaGeology
DS1940-0075
1943
Schenck, E.Schenck, E.Letter Containing a Statement of Verification Regarding Diamonds Produced at Arkansaw Diamond Mine to War Production Board.New York, 2P. UNPUBL.United States, Gulf Coast, Arkansas, PennsylvaniaProduction, Politics
DS1990-1309
1990
Schenk, T.Schenk, T., Zilverstein, O.Experiments with a rule based system for interpreting linear map featuresPhotogrammetric engineering and remote sensing, Vol. 56, No. 6, June pp. 911-917GlobalComputer, Program -GIS linear map features
DS1995-1286
1995
Schenk, V.Moller, A., Appel, P., Mezgerm K., Schenk, V.Evidence for a 2 Ga subduction zone: eclogites in the Usagaran belt ofTanzaniaGeology, Vol. 23, No. 12, Dec. pp. 1067-1070TanzaniaGeochronology, Subduction, eclogites
DS1998-1028
1998
Schenk, V.Moller, A., Mezger, K., Schenk, V.Crustal age domains and the evolution of the continental crust in the Mozambique Belt of Tanzania.Journal of Petrology, Vol. 39, No. 4, Apr. pp. 749-784.TanzaniaGeochronology, Pan African Belt, mantle
DS2003-0660
2003
Schenk, V.John, T., Schenk, V., Haase, K., Scherer, E., Tembe, F.Evidence for a Neoproterozoic ocean in south central Africa from mid oceanic ridgeGeology, Vol. 31, 3, March pp. 243-6.ZambiaGondwana, suture zones, Rodinia, Geothermometry
DS2003-0661
2003
Schenk, V.John, T., Schenk, V., Haase, K., Scherer, E., Tembo, F.Evidence for a Neoproterozoic ocean in south central Africa from mid ocean ridge typeGeology, Vol. 31, 3, March pp. 243-6.ZambiaEclogites, Geochemistry
DS200412-0919
2003
Schenk, V.John, T., Schenk, V., Haase, K., Scherer, E., Tembo, F.Evidence for a Neoproterozoic ocean in south central Africa from mid ocean ridge type geochemical signatures and pressure temperGeology, Vol. 31, 3, March pp. 243-6.Africa, ZambiaEclogite, Geochemistry
DS200712-0494
2007
Schenk, V.Jons, N., Schenk, V., Razakamanana, T.Polymetamorphic evolution of ultrahigh temperature granulites from southern Madagascar: implications for the amalgamation of Gondwana.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p. 256-257.Africa, MadagascarTectonics
DS200712-0495
2007
Schenk, V.Jons, N., Schenk, V., Razakamanana, T.Polymetamorphic evolution of ultrahigh temperature granulites from southern Madagascar: implications for the amalgamation of Gondwana.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p. 256-257.Africa, MadagascarTectonics
DS200712-0944
2007
Schenk, V.Schenk, V., Appel, P., Jons, N., Loose, D., Schumann, A., Wegner, H.Pan-African reworking of the northeastern corner of the Congo Craton in Uganda.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p. 257-258.Africa, UgandaTectonics
DS200712-0945
2007
Schenk, V.Schenk, V., Appel, P., Jons, N., Loose, D., Schumann, A., Wegner, H.Pan-African reworking of the northeastern corner of the Congo Craton in Uganda.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p. 257-258.Africa, UgandaTectonics
DS201012-0260
2010
Schenk, V.Halama, R., Bebout, G.E., John, T., Schenk, V.Nitrogen recycling in subducted oceanic lithosphere: the record in high and ultrahigh pressure metabasaltic rocks.Geochimica et Cosmochimica Acta, Vol. 74, 5, pp. 1636-1652.MantleUHP
DS201112-0405
2011
Schenk, V.Halama, R., Timm, J., Herms, P., Hauff, F., Schenk, V.A stable ( Li,O) and radiogenic (Sr, Nd) isotope perspective on metasomatic processes in a subducting slab.Chemical Geology, Vol. 281, 3-4, pp. 151-166.MantleSubduction
DS201112-0731
2011
Schenk, V.Neils, J., Schenk, V.The ultrahigh temperature granulites of southern Madagascar in a polymetamorphic context: implications for the amalgamation of the Gondwana supercontinent.European Journal of Mineralogy, Vol. 23, 2, pp. 127-156.Africa, MadagascarGondwana tectonics
DS201705-0809
2017
Schenk, V.Benaouda, R., Holzheid, A., Schenk, V., Badra, L., Ennaciri, A.Magmatic evolution of the Jbel Boho alkaline complex in the Bou Azzer In lier ( Anti-Atlas/Morocco) and its relation to REE Mineralization.Journal of African Earth Sciences, Vol. 129, pp. 202-223.Africa, MoroccoAlkaline rocks

Abstract: The Jbel Boho complex (Anti-Atlas/Morocco) is an alkaline magmatic complex that was formed during the Precambrian-Cambrian transition, contemporaneous with the lower early Cambrian dolomite sequence. The complex consists of a volcanic sequence comprising basanites, trachyandesites, trachytes and rhyolites that is intruded by a syenitic pluton. Both the volcanic suite and the pluton are cut by later microsyenitic and rhyolitic dykes. Although all Jbel Boho magmas were probably ultimately derived from the same, intraplate or plume-like source, new geochemical evidence supports the concept of a minimum three principal magma generations having formed the complex. Whereas all volcanic rocks (first generation) are LREE enriched and appear to be formed by fractional crystallization of a mantle-derived magma, resulting in strong negative Eu anomalies in the more evolved rocks associated with low Zr/Hf and Nb/Ta values, the younger syenitic pluton displays almost no negative Eu anomaly and very high Zr/Hf and Nb/Ta. The syenite is considered to be formed by a second generation of melt and likely formed through partial melting of underplated mafic rocks. The syenitic pluton consists of two types of syenitic rocks; olivine syenite and quartz syenite. The presence of quartz and a strong positive Pb anomaly in the quartz syenite contrasts strongly with the negative Pb anomaly in the olivine syenite and suggests the latter results from crustal contamination of the former. The late dyke swarm (third generation of melt) comprises microsyenitic and subalkaline rhyolitic compositions. The strong decrease of the alkali elements, Zr/Hf and Nb/Ta and the high SiO2 contents in the rhyolitic dykes might be the result of mineral fractionation and addition of mineralizing fluids, allowing inter-element fractionation of even highly incompatible HFSE due to the presence of fluorine. The occurrence of fluorite in some volcanic rocks and the Ca-REE-F carbonate mineral synchysite in the dykes with very high LREE contents (Ce ?720 ppm found in one rhyolitic dyke) suggest the fluorine-rich nature of this system and the role played by addition of mineralizing fluids. The REE mineralization expressed as synchysite-(Ce) is detected in a subalkaline rhyolitic dyke (with ?LREE = 1750 ppm) associated with quartz, chlorite and occasionally with Fe-oxides. The synchysite mineralization is probably the result of REE transport by acidic hydrothermal fluids as chloride complex and their neutralization during fluid-rock interaction. The major tectonic change from compressive to extensional regime in the late Neoproterozoic induced the emplacement of voluminous volcaniclastic series of the Ediacran Ouarzazate Group. The alkaline, within-plate nature of the Jbel Boho igneous complex implies that this extensional setting continued during the early Cambrian.
DS201801-0034
2018
Schenk, V.Loose, D., Schenk, V.2.09 Ga old eclogites in the Eburnian - Transamazonian orogen of southern Cameroon: significance for Paleoproterozoic plate tectonics.Precambrian Research, Vol. 304, pp. 1-11.Africa, Camerooneclogites

Abstract: Lenses of retrogressed eclogites occur in a 100 km wide zone of the Nyong Complex, a remnant of the Eburnian-Transamazonian orogen, marking a Palaeoproterozoic suture between the Congo and São Francisco Cratons. The eclogites show trace element pattern (depleted in LREE) similar to those of mid-ocean ridge basalts, indicating that the precursor melts formed in a depleted mantle source and the eclogites formed from oceanic crust. Despite numerous plagioclase ‘exsolutions’ up to 25 mol% jadeite component is preserved in omphacite and points to minimum pressures of 16 kbar at c. 800 °C. Pressures may have been 18-20 kbar as indicated by estimated compositions of peak omphacite. The age of eclogite metamorphism has been constrained by U-Pb SHRIMP dating of zircon at 2093 ± 45 Ma. The eclogites are associated with 2.05 Ga old charnockites and mafic granulites containing textures characteristic for near-isobaric cooling. These rocks may represent the plate above a subduction zone in which the eclogites were tectonically emplaced. With an age of 2.09 Ga the eclogites of the Nyong Complex are older than other subduction related Palaeoproterozoic eclogites of the Ubendian (1.88 Ga) and Usagaran belts (2.0 Ga) at the southern border of the Tanzania Craton. They are also older than eclogites in the Belomorian province (1.9 Ga; Russia) and thus represent the oldest known eclogites outcropping in an orogenic belt. The African eclogites (all with MORB chemistry) indicate that during the formation of the Nuna supercontinent the Palaeoproterozoic oceanic lithosphere around the Congo-Tanzania Craton was thick, cold and rigid enough to become subducted similar to cold oceanic lithosphere in the modern plate tectonic regime. However, apparent geothermal gradients of 12-14 °C/km for the Palaeoproterozoic eclogites are higher than those of Neoproterozoic and Phanerozoic eclogites and are interpreted as the result of warm subduction in a hotter Palaeoproterozoic Earth.
DS201804-0717
2018
Schenk, V.Loose, D., Schenk, V.2.09 Ga old eclogites in the Eburnian Transamazonian orogen of southern Cameroon: significance for Paleoproterozoic plate tectonics.Precambrian Research, Vol. 304, pp. 1-11.Africa, Camerooneclogites

Abstract: Lenses of retrogressed eclogites occur in a 100 km wide zone of the Nyong Complex, a remnant of the Eburnian-Transamazonian orogen, marking a Palaeoproterozoic suture between the Congo and São Francisco Cratons. The eclogites show trace element pattern (depleted in LREE) similar to those of mid-ocean ridge basalts, indicating that the precursor melts formed in a depleted mantle source and the eclogites formed from oceanic crust. Despite numerous plagioclase ‘exsolutions’ up to 25 mol% jadeite component is preserved in omphacite and points to minimum pressures of 16 kbar at c. 800 °C. Pressures may have been 18-20 kbar as indicated by estimated compositions of peak omphacite. The age of eclogite metamorphism has been constrained by U-Pb SHRIMP dating of zircon at 2093 ± 45 Ma. The eclogites are associated with 2.05 Ga old charnockites and mafic granulites containing textures characteristic for near-isobaric cooling. These rocks may represent the plate above a subduction zone in which the eclogites were tectonically emplaced. With an age of 2.09 Ga the eclogites of the Nyong Complex are older than other subduction related Palaeoproterozoic eclogites of the Ubendian (1.88 Ga) and Usagaran belts (2.0 Ga) at the southern border of the Tanzania Craton. They are also older than eclogites in the Belomorian province (1.9 Ga; Russia) and thus represent the oldest known eclogites outcropping in an orogenic belt. The African eclogites (all with MORB chemistry) indicate that during the formation of the Nuna supercontinent the Palaeoproterozoic oceanic lithosphere around the Congo-Tanzania Craton was thick, cold and rigid enough to become subducted similar to cold oceanic lithosphere in the modern plate tectonic regime. However, apparent geothermal gradients of 12-14 °C/km for the Palaeoproterozoic eclogites are higher than those of Neoproterozoic and Phanerozoic eclogites and are interpreted as the result of warm subduction in a hotter Palaeoproterozoic Earth.
DS1940-0219
1949
Schepers, H.J.Schepers, H.J.Die Ontdekking Van Diamante in Suid Afrika: die Geskiedenisen die Ontwikkeling Van die Diamantvelde; N' Bibliographie.Unknown., 7P.South AfricaDiamond Prospecting
DS1991-0114
1991
Schepina, N.A.Bezborodov, S.M., Garanin, V.K., Kudrjavtseva, G.P., Schepina, N.A.The pecularities of the mineral composition of the diamond bearing eclogites from the Udachnaya kimberlite pipeProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 481-483RussiaDiamond morphology, Garnet composition
DS1970-0993
1974
Schepper, R.J.Smith, J.W., Kuntz, C.S., Williams, A.L., Schepper, R.J.Structural and Photographic Lineaments, Gravity, Magnetics And Seismicity of Central United States (us)First International Conference On Basement Tectonics, GlobalMid-continent
DS1995-1031
1995
Scherbaum, F.Kruger, F., Weber, M., Scherbaum, F., Schkittenhardt, J.Evidence for normal and in homogeneous lowermost mantle and core mantle boundary structure under Arctic /CanadaGeophysical Journal of International, Vol. 122, No. 2, August pp. 637-657.Arctic, Northwest TerritoriesMantle, Core
DS1995-1668
1995
Scherbaum, F.Scherbaum, F.Basic concepts in digital signal processing for seismologistsSpringer, 158pGlobalGeophysics -seismics, Book -ad
DS2002-0901
2002
Scherbaum, F.Kruger, F., Scherbaum, F., Rosa, J.W.C., Kind, R., Zetsche, F., Hohne, J.Crustal and upper mantle structure in the Amazon region ( Brasil) determined with broadband mobile stations.Journal of Geophysical Research, Oct. 29, 10.1029/2001JB000598.BrazilGeophysics - seismics, Tectonics
DS2002-0902
2002
Scherbaum, F.Kruger, F., Scherbaum, F., Rosa, J.W.C., Kind, R., Zetsche, F., Hohne, J.Crustal and upper mantle structure in the Amazon region ( Brazil) determined with broadband mobile stations.Journal of Geophysical Research, Vol. 107, 10, ETE 17 DOI 10.1029/2001JB000598BrazilGeophysics - seismics, Tectonics
DS201012-0235
2009
Scherer, A.Gilbertson, A., Gudlewski, B., Jhonson, M., Maltezos, G., Scherer, A., Shigley, J.Cutting diffraction gratings to improve dispersion ( 'fire') in diamonds. A new process of plasma eteching diffraction patterns on diamond facets.Gems & Gemology, Vol. 45, 4, Winter pp. 260-270.TechnologyDiamond cutting
DS2003-0660
2003
Scherer, E.John, T., Schenk, V., Haase, K., Scherer, E., Tembe, F.Evidence for a Neoproterozoic ocean in south central Africa from mid oceanic ridgeGeology, Vol. 31, 3, March pp. 243-6.ZambiaGondwana, suture zones, Rodinia, Geothermometry
DS2003-0661
2003
Scherer, E.John, T., Schenk, V., Haase, K., Scherer, E., Tembo, F.Evidence for a Neoproterozoic ocean in south central Africa from mid ocean ridge typeGeology, Vol. 31, 3, March pp. 243-6.ZambiaEclogites, Geochemistry
DS200412-0919
2003
Scherer, E.John, T., Schenk, V., Haase, K., Scherer, E., Tembo, F.Evidence for a Neoproterozoic ocean in south central Africa from mid ocean ridge type geochemical signatures and pressure temperGeology, Vol. 31, 3, March pp. 243-6.Africa, ZambiaEclogite, Geochemistry
DS1993-0272
1993
Scherer, E.E.Collerson, K.D., Scherer, E.E., MacDonald, R.The evolution of Wyoming craton lower crust: uranium-lead (U-Pb) (U-Pb) shrimp and neodymium-Sr isotopic evidence for middle Archean and Early Proterozoic events.The Xenolith window into the lower crust, abstract volume and workshop, p. 4.MontanaCraton
DS1997-1002
1997
Scherer, E.E.Scherer, E.E., Cameron, K.L., Johnson, C.M., Beard, B.Lutetium - Hafnium geochronology applied to dating Cenozoic events affecting lower crustal xenoliths Kilbourne Hole.Chemical Geol., Vol. 142, No. 1-2, Oct. 20, pp. 63-78.New MexicoGeochronology, Kilbourne Hole
DS2000-0865
2000
Scherer, E.E.Scherer, E.E., Cameron, K.L., Blichert-Toft, J.Lutetium - Hafnium garnet geochronology: closure temperature relative to the Sm neodymium system - effects trace inclusionsGeochimica et Cosmochimica Acta, Vol. 64, No. 19, Oct. 1, pp. 3413-32.GlobalGarnet - geochronology
DS200712-0946
2007
Scherer, E.E.Scherer, E.E., Whitehouse, M.J., Munker, C.Zircon as a monitor of crustal growth.Elements, Vol. 3, 1, Feb. pp. 19-24.TechnologyZircon geochronology
DS200812-1020
2008
Scherer, E.E.Schmidt, A., Weyer, S., Mezger, K., Scherer, E.E., Xiao, Y., Hoefs, J., Brey, G.P.Rapid eclogization of the Dabie Sulu UHP terrane: constraints from Lu Hf garnet geochronology.Earth and Planetary Science Letters, Vol. 273, 1-2, Aug. 30, pp. 203-213.ChinaUHP
DS200812-1021
2008
Scherer, E.E.Schmidt, A., Weyer, S., Mezger, K., Scherer, E.E., Xiao, Y., Hoefs, J., Brey, G.P.Rapid eclogitization of the Dabie Sulu UHP terrane: constraints from Lu Hf garnet geochronology.Earth and Planetary Science Letters, In press available, 49p.ChinaUHP
DS201112-0976
2011
Scherer, E.E.Smit, M.A., Scherer, E.E., John, T., Janssen, A.Creep of garnet in eclogite: mechanisms and implications.Earth and Planetary Science Letters, Vol. 311, 3-4, pp. 411-419.MantlePetrology
DS201412-0044
2013
Scherer, E.E.Baxter, E.F., Scherer, E.E.Garnet geochronology: timekeeper of tectonometamorphic processes.Elements, Vol. 9, 6, Dec. pp. 433-438.MantleGeochronology
DS1990-1492
1990
Scherer, G.G.Van Arsdale, E.B., Scherer, G.G., Schweig, E.S., Williams, R.A.Seismic reflection survey of Crowley's Ridge ArkansawEos, Vol. 71, No. 43, October 23, p. 1435 AbstractArkansasGeophysics -seismics, Crowley's Ridge
DS201112-0527
2011
Scherer, J.E.E.Klemd, R., Scherer, J.E.E., Rondenay, S., Gao, J.Changes in dip of subducted slabs at depth: petrological and geochronological evidence from HP-UHP rocks (Tianshan, NW China).Earth and Planetary Science Letters, Vol. 310, 1-2, pp. 9-20.ChinaUHP
DS1997-1003
1997
Scherer, T.Scherer, T., Hafner, S.S., et al.Defects in natural diamonds depending on geological environmentProceedings 30th. I.G.C., Pt. 16, pp. 1-15.South Africa, Germany, RussiaDiamond morphology, Deposit - Finsch, Popigai
DS2003-0136
2003
Scheringer, M.Boschen, S., Lenoir, D., Scheringer, M.Sustainable chemistry: starting points and prospectsNaturwissenschaftern, Vol. 90, pp. 93-102.GlobalChemistry - review not specific to diamonds
DS201611-2109
2016
Scherler, D.Ganti, V., Von Hagke, C., Scherler, D., Lamb, M.P., Fischer, W.W., Avouac, J-P.Time scale bias in erosion rates of glaciated landscapes.Science Advances, Vol. 2, 10, 3p.GlobalGlaciology

Abstract: Deciphering erosion rates over geologic time is fundamental for understanding the interplay between climate, tectonic, and erosional processes. Existing techniques integrate erosion over different time scales, and direct comparison of such rates is routinely done in earth science. On the basis of a global compilation, we show that erosion rate estimates in glaciated landscapes may be affected by a systematic averaging bias that produces higher estimated erosion rates toward the present, which do not reflect straightforward changes in erosion rates through time. This trend can result from a heavy-tailed distribution of erosional hiatuses (that is, time periods where no or relatively slow erosion occurs). We argue that such a distribution can result from the intermittency of erosional processes in glaciated landscapes that are tightly coupled to climate variability from decadal to millennial time scales. In contrast, we find no evidence for a time scale bias in spatially averaged erosion rates of landscapes dominated by river incision. We discuss the implications of our findings in the context of the proposed coupling between climate and tectonics, and interpreting erosion rate estimates with different averaging time scales through geologic time.
DS1990-1313
1990
Schermerhorn, L.J.G.Schmidt, K._H., Schermerhorn, L.J.G.Geomorphology and geochemistry of the Foum-el-Kous ankaratite, southMoroccoTerra, Abstracts of Crustal Dynamics: Pathways and Records held Bochum FRG, Vol. 2, December p. 57GlobalAlkaline rocks, Ankaratite
DS200412-1315
2004
Scherneck, H.G.Milne, G.A., Mitrovica, J.X., Scherneck, H.G., Davis, J.L., Johansson, J.M., Koivula, H., Vermeer, M.Continuous GPS measurements of Post glacial adjustment in Fennoscandia: 2. modeling results.Journal of Geophysical Research, Vol. 109, B2, 10.1029/2003 JB002619Europe, FennoscandiaGeophysics -
DS200512-0079
2005
Scherneck, H.G.Bergstrand, S., Scherneck, H.G., Milne, G.A., Johannseon, J.M.Upper mantle viscosity from continuous GPS baselines in Fennoscandia.Journal of Geodynamics, Vol. 39, 2, pp. 91-109.Europe, Finland, Sweden, Baltic ShieldGeophysics - seismics
DS2002-1416
2002
Scherneck, H-G.Scherneck, H-G., Johansson, J.M., et al.BIFROST: observing the three dimensional deformation of FennoscandiaAmerican Geophysical Union, Geodynamics Series, Vol. 29, pp. 69-94.Scandinavia, Finland, Sweden, NorwayGeophysics, tectonics
DS200412-1746
2002
Scherneck, H-G.Scherneck, H-G., Johansson, J.M., et al.BIFROST: observing the three dimensional deformation of Fennoscandia.American Geophysical Union, Geodynamics Series, Vol. 29, pp. 69-94.Europe, ScandinaviaGeophysics, tectonics
DS2000-0866
2000
Schersten, A.Schersten, A., Areback, H., Armstrong, R.Dating mafic - ultramafic intrusions by ion microprobing contact melt zircon: examples from southwest...Contrib. Min. Pet., Vol. 139, No. 1, pp. 115-SwedenGeochronology
DS2000-0867
2000
Schersten, A.Schersten, A., Cornell, D.Documentation of a hydrous ultramafic magma intrusion in the 1.62 Ga crust of southern Sweden.Gff., Vol. 122, pp. 251-55.SwedenSubduction, Magma, Mantle
DS200412-1747
2004
Schersten, A.Schersten, A., Elliott, T., Hawkesworth, C., Norman, M.Tungsten isotope evidence that mantle plumes contain no contribution from the Earth's core.Nature, No. 6971, pp. 234-6.MantleGeochronology, plumes
DS200912-0244
2009
Schersten, A.Gerdes, A., Kemp, A.L.S., Hancher, J.M., Schersten, A.Accessory minerals as tracers of crustal processes.Chemical Geology, Vol. 261, 3-4, April 30, pp. 197-198/MantleMineral chemistry
DS201212-0714
2012
Schersten, A.Szilas, K., Naeraa, T., Schersten, A., Stendal, H., Frei, R., Van Hinsberg, V.J., Kokfelt, T.F., Rosing, M.T.Origin of Mesoarchean arc related rocks with boninite-komatiite affinities from southern West Greenland.Lithos, in pressEurope, GreenlandBoninites
DS1990-1317
1990
Schertl, H.P.Schreyer, W., Tilton, G.R., Schertl, H.P.Toward a P-T time path for the pyrope-coesite rocks of the Dora Mairamassif, western AlpsTerra, Abstracts of Crustal Dynamics: Pathways and Records held Bochum FRG, Vol. 2, December p. 32AlpsCoesite, Petrology
DS1991-1513
1991
Schertl, H.P.Schertl, H.P., Schreyer, W., Chopin, C.The pyrope-coesite rocks and their country rocks at Parigi, Dora MairaMassif, western Alps, detailed petrography, mineral chemistry and PT pathContributions to Mineralogy and Petrology, Vol. 108, No. 1-2, pp. 1-21ItalyMineralogy, Coesite
DS1994-1539
1994
Schertl, H.P.Schertl, H.P., Okay, A.I.A coesite inclusion in dolomite from Dabie Shan, China: petrological and rheological significance.European Journal of Mineralogy, No. 6, pp. 995-1000.ChinaCoesite, mineralogy, Deposit -Dabie Shan area
DS1995-1669
1995
Schertl, H.P.Schertl, H.P., Okay, A.I.A coesite inclusion in dolomite in Dabie Shan, China: petrological and rheological significance.European Journal of Mineralogy, Vol. 6, No. 6, Nov. 1, pp. 995-1006.ChinaCoesite, Deposit - Dabie Shan area
DS2001-1097
2001
Schertl, H.P.Sobolev, N.V., Schertl, H.P., Burchard, M., Shatsky, V.An unusual pyrope grossular garnet and its paragenesis from Diamondiferous carbonate silicate rocks KokchetavDoklady Academy of Sciences, Vol. 380, No. 7, Sept-Oct. pp.791-4.Russia, KazakhstanMineralogy - pyrope, Deposit - Kokchetav Massif
DS200412-1748
2004
Schertl, H.P.Schertl, H.P., Neuser, R.D., Sobolev, N.V., Shatsky, V.S.UHP metamorphic rocks from Dora Maira Western Alps and Kokchetav Kazakhstan: new insights using cathodluminescence petrography.European Journal of Mineralogy, Vol. 16, 1, pp. 49-57.KazakhstanUHP
DS200612-1234
2005
Schertl, H.P.Schertl, H.P., Medenbach, O., Neuser, R.D.UHP metamorphic rocks from Dora Maira, western Alps: cathodluminescence of silica and twinning of coesite.Russian Geology and Geophysics, Vol. 46, 12, pp. 1327-1332.Europe, AlpsUHP - coesite
DS200612-1331
2006
Schertl, H.P.Sobolev, N.V., Schertl, H.P., Neuser, R.D.Composition and paragenesis of garnets from ultrahigh pressure calc-silicate metamorphic rocks of the Kokchetav massif.Russian Geology and Geophysics, Vol. 47, 4, pp. 519-Russia, KazakhstanUHP - geochemistry garnets
DS200912-0854
2009
Schertl, H.P.Zhang, Z.M., Schertl, H.P., Wang, J.L., Shen, K., Liou, J.G.Source of coesite inclusions within inherited magmatic zircon from Sulu UHP rocks, eastern China, and their bearing for fluid rock interaction and SHRIMP dating.Journal of Metamorphic Geology, Vol. 27, 4, pp. 317-333.ChinaUHP
DS201012-0573
2009
Schertl, H.P.Perchuk, A.L., Davydova, V.V., Burchard, M., Maresch, W.V., Schertl, H.P., Yapaskurt, V.O., Safonov, O.G.Modification of mineral inclusions in garnet under high pressure conditions: experimental simulation and application to carbonate silicate rocks of KokchetetavRussian Geology and Geophysics, Vol. 50, 12, pp. 1153-1168.RussiaMineralogy
DS200512-0793
2005
Schertl, H-P.Nosenfelder, J.L., Schertl, H-P., Smyth, J.R., Liou, J.G.Factors in the preservation of coesite: the importance of fluid infiltration.American Mineralogist, Vol. 90, pp. 779-789.MantleUHP - coesite
DS200612-0613
2006
Schertl, H-P.Hwang, S.L., Chu, H-T., Yui, T-F., Shen, P., Schertl, H-P., Liou, J.G., Sobolev, N.V.Nanometer size P/K rich silica glass (former melt) inclusions in microdiamond from the gneisses of Kokchetav and Erzgebirge massifs: diversified...Earth and Planetary Science Letters, in pressRussia, Europe, GermanyUHP metamorphic microdiamonds, host rock buffering
DS200612-1073
2005
Schertl, H-P.Perchuk, A.L., Burchard, M., Maresch, W.V., Schertl, H-P.Fluid mediated modification of garnet interiors under ultrahigh pressure conditions.Terra Nova, Vol. 17, 6, pp. 545-553.MantleUHP
DS200712-1010
2007
Schertl, H-P.Sobolev, N.V., Schertl, H-P., Neuser, R.D., Shatsky, V.S.Relict unusually low iron pyrope grossular garnets from UHPM calc-silicate rocks of the Kochetav Massif, Kazakhstan.International Geology Review, Vol. 49, 8, pp. 717-731.Russia, KazakhstanUHP
DS200812-1015
2008
Schertl, H-P.Schertl, H-P., Schreyer, W.Geochemistry of coesite bearing pyrope quartzite and related rocks from the Dora Massif Western Alps.European Journal of Mineralogy, Vol. 20, 5, pp. 791-809.EuropeCoesite
DS201112-0982
2011
Schertl, H-P.Sobolev, N.V., Schertl, H-P., Valley, J.W., Page, F.Z., Kita, N.T., Spicuzza, M.J., Neuser, R.D., Logvinova, A.M.Oxygen isotope variations of garnets and clinopyroxenes in a layered Diamondiferous calcsilicate rock from Kokchetav Massif, Kazakhstan: a window into geochemicalContributions to Mineralogy and Petrology, Vol. 162, 5, pp.1079-1092.Russia, KazakhstanDeeply subducted UHPM rocks
DS201312-0329
2013
Schertl, H-P.Gotze, J.,Schertl, H-P.,Neurser, R.D., Kempe, U.Optical microscope cathodoluminesence (OM-CL) imaging as a powerful tool to reveal internal textures of minerals.Mineralogy and Petrology, Vol. 107, 3, pp. 373-392.TechnologySpectroscopy
DS201312-0783
2013
Schertl, H-P.Schertl, H-P., O'Brien, P.J.Continental crust at mantle depths: key minerals and microstructures.Elements,, Vol. 9, 4, August pp. 261-266.MantleMineralogy
DS201502-0086
2015
Schertl, H-P.Neuser, R.D., Schertl, H-P., Logvinova, A.M., Sobolev, N.V.An EBSD study of olivine inclusions in Siberian diamonds: evidence for syngenetic growth?Russian Geology and Geophysics, Vol. 56, 1, pp. 321-329.RussiaDiamond morphology
DS201502-0103
2015
Schertl, H-P.Sobolev, N.V., Dobretsov, N.I., Ohtani, E., Taylor, L.A., Schertl, H-P., Palyanov, Yu.N.Problems related to crystallogenesis and the deep carbon cycle.Russian Geology and Geophysics, Vol. 56, 1-2, pp. 1-12.MantleCarbon cycle
DS201601-0042
2015
Schertl, H-P.Schertl, H-P.Diamonds in the Kokchetav Massif.Acta Geologica Sinica, Vol. 89, 2, pp. 81-83.RussiaKokchetav massif
DS201607-1301
2016
Schertl, H-P.Hart, E., Storey, C., Bruand, E., Schertl, H-P., Alexander, B.D.Mineral inclusions in rutile: a novel recorder of HP-UHP.Earth and Planetary Science Letters, Vol. 446, pp. 137-148.MantleCoesite, subduction

Abstract: The ability to accurately constrain the secular record of high- and ultra-high pressure metamorphism on Earth is potentially hampered as these rocks are metastable and prone to retrogression, particularly during exhumation. Rutile is among the most widespread and best preserved minerals in high- and ultra-high pressure rocks and a hitherto untested approach is to use mineral inclusions within rutile to record such conditions. In this study, rutiles from three different high- and ultrahigh-pressure massifs have been investigated for inclusions. Rutile is shown to contain inclusions of high-pressure minerals such as omphacite, garnet and high silica phengite, as well as diagnostic ultrahigh-pressure minerals, including the first reported occurrence of exceptionally preserved monomineralic coesite in rutile from the Dora -Maira massif. Chemical comparison of inclusion and matrix phases show that inclusions generally represent peak metamorphic assemblages; although rare prograde phases such as titanite, omphacite and corundum have also been identified implying that rutile grows continuously during prograde burial and traps mineralogic evidence of this evolution. Pressure estimates obtained from mineral inclusions, when used in conjunction with Zr-in-rutile thermometry, can provide additional constraints on the metamorphic conditions of the host rock. This study demonstrates that rutile is an excellent repository for high- and ultra-high pressure minerals and that the study of mineral inclusions in rutile may profoundly change the way we investigate and recover evidence of such events in both detrital populations and partially retrogressed samples.
DS201607-1387
2016
Schertl, H-P.Yang, J., Dilek, Y., Pearce, J., Schertl, H-P., Zhang, C.Diamonds and crustal recycling into deep mantle.IGC 35th., Session The Deep Earth 1 p. abstractMantleSubduction
DS201805-0973
2017
Schertl, H-P.Ravna, E.K., Zozulya, D., Kullerud, K., Corfu, F., Nabelek, P.I., Janak, M., Slagstad, T., Davidsen, B., Selbekk, R.S., Schertl, H-P.Deep seated carbonatite intrusion and metasomatism in the UHP Tromso Nappe, northern Scandinavian Caledonides - a natural example of generation of carbonatite from carbonated eclogite.Journal of Petrology, Vol. 58, 12, pp. 2403-2428.Europe, Sweden, Norwaycarbonatite

Abstract: Carbonatites (sensu stricto) are igneous rocks typically associated with continental rifts, being emplaced at relatively shallow crustal levels or as extrusive rocks. Some carbonatites are, however, related to subduction and lithospheric collision zones, but so far no carbonatite has been reported from ultrahigh-pressure (UHP) metamorphic terranes. In this study, we present detailed petrological and geochemical data on carbonatites from the Tromsø Nappe—a UHP metamorphic terrane in the Scandinavian Caledonides. Massive to weakly foliated silicate-rich carbonate rocks, comprising the high-P mineral assemblage of Mg-Fe-calcite?±?Fe-dolomite?+?garnet?+?omphacitic clinopyroxene?+?phlogopite?+?apatite?+?rutile?+?ilmenite, are inferred to be carbonatites. They show apparent intrusive relationships to eclogite, garnet pyroxenite, garnet-mica gneiss, foliated calc-silicate marble and massive marble. Large grains of omphacitic pyroxene and megacrysts (up to 5?cm across) of Cr-diopside in the carbonatite contain rods of phlogopite oriented parallel to the c-axis, the density of rods being highest in the central part of the megacrysts. Garnet contains numerous inclusions of all the other phases of the carbonatite, and, in places, composite polyphase inclusions. Zircon, monazite and allanite are common accessory phases. Locally, veins of silicate-poor carbonatite (up to 10?cm across) occur. Extensive fenitization by K-rich fluids, with enrichment in phlogopite along contacts between carbonatite and silicate country rocks, is common. Primitive mantle-normalized incompatible element patterns for the carbonatite document a strong enrichment of light rare earth elements, Ba and Rb, and negative anomalies in Th, Nb, Ta, Zr and Hf. The carbon and oxygen isotope compositions of the carbonatite are distinctly different from those of the spatially associated calc-silicate marble, but also from mantle-derived carbonatites elsewhere. Neodymium and Sr isotope data coupled with the trace element distribution indicate a similarity of the Tromsø carbonatite to orogenic (off-craton) carbonatites rather than to anorogenic (on-craton) ones. U-Pb dating of relatively U-rich prismatic, oscillatory-zoned zircon gives an age of 454•5?±?1•1?Ma. We suggest that the primary carbonatite magma resulted from partial melting of a carbonated eclogite at UHP, in a deeply subducted continental slab.
DS201710-2266
2017
Schertle, H-P.Sobolev, N.V., Schertle, H-P., Neuser, R.D., Tomilenko, A.A., Kuzmin, D.V., Loginova, A.M., Tolstov, A.V., Kostrovitsky, S.I., Yakovlev, D.A., Oleinikov, O.B.Formation and evolution of hypabyssal kimberlites from the Siberian craton: part 1 - new insights from cathodluminescence of the carbonates. Anabar and Olenek areaJournal of Asian Earth Sciences, Vol. 145, pt. B, pp. 670-678.Russia, Siberiadeposit - Kuranakh, Kharamay
DS2002-1417
2002
Scherwath, M.Scherwath, M., Stern, T., Melhuish, A., Molnar, P.Pn anisotropy and distributed upper mantle deformation associated with a continential transform fault.Geophysical Research Letters, Vol. 89, No. 8, April 15, pp. 16-MantleTectonics, Geophysics - seismics
DS2000-0646
2000
SchetselaarMcDonough, M.R., McNicoll, V.J., Schetselaar, GroverGeochronological and kinematic constraints on crustal shortening and escape in a two sided oblique slip...Canadian Journal of Earth Sciences, Vol.37, no11, Nov.pp.1549-73.Alberta, northeasternTectonics - Paleoproterozoic Taltson magmatic zone, Geochronology
DS200712-0769
2006
SchetselaarNadeau, L., Ryan, J.J., Hinchey, A.M., James, Sandeman, Tremblay, Schetselaar, Berman, DavisOutlook on the geology of the Boothia MaIn land area, Kitikmeot region, Nunavut.34th Yellowknife Geoscience Forum, p. 39-40. abstractCanada, NunavutGeology - brief overview
DS201809-2093
2018
Schetselaar, E.Snyder, D.B., Schetselaar, E., Pilkington, M., Schaeffer, A.J.Resolution and uncertainty in lithospheric 3-D geological models. Canada MohoMineralogy and Petrology, doi.org/10.1007/ s00710-018-0619-2. 15p.MantleGeophysics

Abstract: As three-dimensional (3-D) modelling of the subcontinental mantle lithosphere is increasingly performed with ever more data and better methods, the robustness of such models is increasingly questioned. Resolution thresholds and uncertainty within deep multidisciplinary 3-D models based on geophysical observations exist at a minimum of three levels. Seismic waves and potential field measurements have inherent limitations in resolution related to their dominant wavelengths. Formal uncertainties can be assigned to grid-search type forward or inverse models of observable parameter sets. Both of these uncertainties are typically minor when compared to resolution limitations related to the density and shape of a specific observation array used in seismological or potential field surveys. Seismic wave source distribution additionally applies in seismology. A fourth, more complex level of uncertainty relates to joint inversions of multiple data sets. Using independent seismic wave phases or combining diverse methods provides another measure of uncertainty of particular physical properties. Extremely sparse xenolith suites provide the only direct correlation of rock type with observed or modelled physical properties at depths greater than a few kilometers. Here we present one case study of the Canadian Mohorovi?i? (Moho) discontinuity using only two data sets. Refracted and converted seismic waves form the primary determinations of the Moho depth, gravity field modeling provide a secondary constraint on lateral variations, the slope of the Moho, between the sparse seismic estimates. Although statistically marginal, the resulting co-kriged Moho surface correlates better with surface geology and is thus deemed superior.
DS1994-1540
1994
Schetselaar, E.M.Schetselaar, E.M.A comparative evaluation of the potential of C-Band airborne SAR Archean Hood River belt, Bathurst InletCanadian Journal of Remote Sensing, Vol. 20, No. 3, Sept. pp. 302-216Northwest TerritoriesRemote sensing - SAR, Hood River Belt
DS200612-1235
2005
Schettino, A.Schettino, A., Scotese, C.R.Apparent polar wander paths for the major continents ( 200 Ma to the present day): a paleomagnetic reference frame for global plate tectonic reconstructions.Geophysical Journal International, Vol. 163, 2, Nov., pp. 727-759.GlobalGeophysics - paleomagnetism
DS201112-0922
2011
Schettino, A.Schettino, A., Tassi, L.Tranch curvature and deformation of the subducting lithosphere.Geophysical Journal International, in press availableMantleSubduction
DS201812-2902
2018
Schettino, E.Zhao, S., Schettino, E., Merlini, M., Poli, S.The stability and melting of aragonite: an experimental and thermodynamic model for carbonated eclogites in the mantle.Lithos, doi.org/10.1016/ j.lithos.2018.11.005 38p.Mantleeclogite

Abstract: Subduction of calcium carbonate, sequestered in the oceanic crust by hydrothermal metamorphism and biogenic action, accounts for a significant flux of carbon into the mantle, where it contributes to the genesis of carbonatitic and silica-undersaturated melts. However, the reported phase relations in the system CaCO3, notably the transition boundary from disordered calcite (calcite V, here ccv) to aragonite (ara), vary considerably among different studies. Moreover, the thermodynamic properties of ccv and of liquid CaCO3 (CaCO3L) remain to be determined. In order to address the dearth of experimental data on phase relations, and to determine a set of internally consistent thermodynamic properties for ara, ccv and CaCO3L, multi-anvil experiments were performed at 3-6?GPa and 1300-1750?°C. By re-evaluating all experimental data, the transformation of ccv-ara fits the equation Tccv-ara?=?397.6?+?320.17?×?P and the melting curve Tm?=?1578.9?+?139.65?×?P???11.646?×?P2, where pressure is in GPa and temperature in K. Thermodynamic properties retrieved for calcite V and liquid CaCO3 are used to compute phase diagrams of relevance for chemical compositions representative of eclogite heterogeneities of the astenospheric mantle, and compared with experimentally derived phase relationships. Aragonite represents a carbonate of major abundance in carbonated eclogites at high temperature, close to the solidus; its ability to fractionate REE and Ba-Sr contributes to the peculiar geochemical signatures of silica undersaturated magmas. The relatively refractory nature of aragonite impacts on our understanding of the deep carbon cycle.
DS201902-0335
2019
Schettino, E.Zhao, S., Schettino, E., Merlini, M., Poli, S.The stability and melting of aragonite: an experimental and thermodynamic model for carbonated eclogites in the mantle.Lithos, Vo.. 324, 1, pp. 105-114.Mantleeclogites

Abstract: Subduction of calcium carbonate, sequestered in the oceanic crust by hydrothermal metamorphism and biogenic action, accounts for a significant flux of carbon into the mantle, where it contributes to the genesis of carbonatitic and silica-undersaturated melts. However, the reported phase relations in the system CaCO3, notably the transition boundary from disordered calcite (calcite V, here ccv) to aragonite (ara), vary considerably among different studies. Moreover, the thermodynamic properties of ccv and of liquid CaCO3 (CaCO3L) remain to be determined. In order to address the dearth of experimental data on phase relations, and to determine a set of internally consistent thermodynamic properties for ara, ccv and CaCO3L, multi-anvil experiments were performed at 3-6?GPa and 1300-1750?°C. By re-evaluating all experimental data, the transformation of ccv-ara fits the equation Tccv-ara?=?397.6?+?320.17?×?P and the melting curve Tm?=?1578.9?+?139.65?×?P???11.646?×?P2, where pressure is in GPa and temperature in K. Thermodynamic properties retrieved for calcite V and liquid CaCO3 are used to compute phase diagrams of relevance for chemical compositions representative of eclogite heterogeneities of the astenospheric mantle, and compared with experimentally derived phase relationships. Aragonite represents a carbonate of major abundance in carbonated eclogites at high temperature, close to the solidus; its ability to fractionate REE and Ba-Sr contributes to the peculiar geochemical signatures of silica undersaturated magmas. The relatively refractory nature of aragonite impacts on our understanding of the deep carbon cycle.
DS202008-1396
2020
Schettino, E.Gonzales-Jiminez, J.M., Tassara, S., Schettino, E., Roque-Rosell, J., Farre-de-Pablo, J., Saunders, J.E., Deditius, A.P., Colas, V., Rovira-Medina, J.J., Guadalupe Davalos, M., Schilling, M., Jiminez-Franco, A., Marchesi, C., Nieto, F., Proenza, J.A., GerMineralogy of the HSE in the subcontinental lithospheric mantle - an interpretive review.Lithos, in press available, 44p. PdfMantleHSE

Abstract: The highly siderophile elements (HSE: Os, Ir, Ru, Rh, Pt, Pd, Re, Au) exist in solid solution in accessory base-metal sulfides (BMS) as well as nano-to-micron scale minerals in rocks of the subcontinental lithospheric mantle (SCLM). The latter include platinum-group minerals (PGM) and gold minerals, which may vary widely in morphology, composition and distribution. The PGM form isolated grains often associated with larger BMS hosted in residual olivine, located at interstices in between peridotite-forming minerals or more commonly in association with metasomatic minerals (pyroxenes, carbonates, phosphates) and silicate glasses in some peridotite xenoliths. The PGM found inside residual olivine are mainly Os-, Ir- and Ru-rich sulfides and alloys. In contrast, those associated with metasomatic minerals or silicate glasses of peridotite xenoliths consist of Pt, Pd, and Rh bonded with semimetals like As, Te, Bi, and Sn. Nanoscale observations on natural samples along with the results of recent experiments indicate that nucleation of PGM is mainly related with the uptake of HSE by nanoparticles, nanominerals or nanomelts at high temperature (> 900?°C) in both silicate and/or sulfide melts, regardless of the residual or metasomatic origin of their host minerals. A similar interpretation can be assumed for gold minerals. Our observations highlight that nanoscale processes play an important role on the ore-forming potential of primitive mantle-derived magmas parental to magmatic-hydrothermal deposits enriched in noble metals. The metal inventory in these magmas could be related with the physical incorporation of HSE-bearing nanoparticles or nanomelts during processes of partial melting of mantle peridotite and melt migration from the mantle to overlying continental crust.
DS201504-0184
2015
Schettler, G.Berryman, E.J., Wunder, B., Wirth, R., Rhede, D., Schettler, G., Franz, G., Heinrich, W.An experimental study on K and Na in corporation in dravitic tourmaline and insight into the origin of Diamondiferous tourmaline from the Kokchetav Massif, Kazakhstan.Contributions to Mineralogy and Petrology, Vol. 169, 19p.Russia, KazakhstanDiamondiferous tourmaline

Abstract: Tourmaline was synthesized in the system MgO-Al2O3-B2O3-SiO2-KCl-NaCl-H2O from an oxide mixture and excess fluid at 500-700 °C and 0.2-4.0 GPa to investigate the effect of pressure, temperature, and fluid composition on the relative incorporation of Na and K in dravitic tourmaline. Incorporation of K at the X-site increases with pressure, temperature, and KCl concentration; a maximum of 0.71 K pfu (leaving 0.29 X-vacant sites pfu) was incorporated into K-dravite synthesized at 4.0 GPa, 700 °C from a 4.78 m KCl, Na-free fluid. In contrast, Na incorporation depends predominately on fluid composition, rather than pressure or temperature; dravite with the highest Na content of 1.00 Na pfu was synthesized at 0.4 GPa and 700 °C from a 3.87 m NaCl and 1.08 m KCl fluid. All synthesized crystals are zoned, and the dominant solid solution in the Na- and K-bearing system is between magnesio-foitite [?(Mg2Al)Al6Si6O18(BO3)3(OH)3OH] and dravite [NaMg3Al6Si6O18(BO3)3(OH)3(OH)], with the dravitic component increasing with the concentration of Na in the fluid. In the K-bearing, Na-free system, the dominant solid solution is between magnesio-foitite and K-dravite [KMg3Al6Si6O18(BO3)3(OH)3(OH)], with the K-dravitic component increasing with pressure, temperature, and the concentration of K in the fluid. The unit-cell volume of tourmaline increases with K incorporation from 1555.1(3) to 1588.1(2) Å3, reflecting the incorporation of the relatively large K+ ion. Comparison of our results to the compositional data for maruyamaite (K-dominant tourmaline) from the ultrahigh-pressure rocks of the Kokchetav Massif in Kazakhstan suggests that the latter was formed in a K-rich, Na-poor environment at ultrahigh-pressure conditions near the diamond-stability field.
DS1993-1300
1993
Scheuber, E.Reutter, K.J., Scheuber, E., Wigger, P.J.Tectonics of the southern Central AndesSpringer Verlag, 300p. plus 3 maps, approx. $ 260.00Chile, Argentina, Bolivia, AndesTable of contents, Structure, tectonics, sedimentology, metallogeny
DS1910-0433
1914
Scheuring, G.Scheuring, G.Die Mineralogische Zusammensetzung der D.s.w.a. DiamantsandeBeitr. Geol. Erf. Deut. Schutzgeb., Vol. 6, PT. 8, PP. PP. 2-48.Southwest Africa, NamibiaMineralogy, Marine Diamond Placers
DS200412-1790
2004
Scheurs, G.Seward, D., Grujic, D., Scheurs, G.An insight into the breakup of Gondwana: identifying events through low temperature thermochronology from the basement rocks ofTectonics, Vol. 23, 3, June 8, TC3007 10.1029/2003 TC001556Africa, MadagascarTectonics
DS1990-1473
1990
Schewchenko, N.Tooker, M., Schewchenko, N., Bonham-Carter, G.F., Renze, A.N.Plotter- a fortran program using UNIRAS for plotting SPANS and EASI/PACEimagesGeological Survey of Canada Open File, No. 2255, 43p. Report and 1 diskette $ 23.00GlobalComputer, Program -PLOTTER.
DS2000-0124
2000
SchianoBurton, K.W., Schiano, Birck, Allegre, Dawson, et al.The distribution and behaviour of rhenium and osmium amongst mantle minerals and the age of lithospheric...Earth and Planetary Science Letters, Vol.183, No.1-2, Nov.30, pp.93-106.TanzaniaGeochronology, Mineral chemistry
DS2002-0229
2002
SchianoBurton, K.W., Gannoun, Birck, Allegre, Schiano,AlardThe compatibility of rhenium and osmium in natural olivine and their behaviour during mantle melting...Earth and Planetary Science Letters, Vol.198,1-2,pp.63-76., Vol.198,1-2,pp.63-76.MantleMineralogy - olivine, Basalt genesis
DS2002-0230
2002
SchianoBurton, K.W., Gannoun, Birck, Allegre, Schiano,AlardThe compatibility of rhenium and osmium in natural olivine and their behaviour during mantle melting...Earth and Planetary Science Letters, Vol.198,1-2,pp.63-76., Vol.198,1-2,pp.63-76.MantleMineralogy - olivine, Basalt genesis
DS1993-1388
1993
Schiano, P.Schiano, P., Algre, C.J., Dupre, B., Lewin, E., Joron, J-L.Variability of trace elements in basaltic suitesEarth and Planetary Science Letters, Vol. 119, No. 1-2, August pp. 37-52GlobalGeochemistry, Basalt
DS1993-1389
1993
Schiano, P.Schiano, P., Clochiatti, R., Mattielli, N., Shimizu, N.Melt and fluid inclusions in peridoite xenoliths from the KerguelenArchipelago.Eos, Transactions, American Geophysical Union, Vol. 74, No. 16, April 20, supplement abstract p. 320.GlobalXenoliths
DS1994-1541
1994
Schiano, P.Schiano, P., Clocchiatti, R.Worldwide occurrence of silica rich melts in sub-continental and sub-oceanic mantle mineralsNature, Vol. 368, April 14, pp. 621-624MantleMineralogy, Silica rich melts
DS1994-1542
1994
Schiano, P.Schiano, P., Clocchiatti, R., Shimizu, N.Melt inclusions trapped in mantle minerals: a clue to identifyingmetasomatic agents in upper mantle.Mineralogical Magazine, Vol. 58A, pp. 807-808. AbstractMantleMetasomatism
DS1994-1543
1994
Schiano, P.Schiano, P., Clochhian, R., Shimizu, N., Weis, D.Cogenetic silica rich and carbonate rich melts trapped in mantle minerals in Kerguelen ultramafic xenoliths -implications for metasomatism in the oceanic upper mantlEarth Planet. Sci. Letters, Vol. 123, No. 1-2, May pp. 167-178.Mantle, OceanicCarbonatite, Metasomatism, Xenoliths -Kerguelen ultramafic
DS1995-1670
1995
Schiano, P.Schiano, P., Clocchiatti, R., et al.Hydrous, silica rich melts in the sub-arc mantle and their relationship with erupted arc lavasNature, Vol. 377, No. 6550, Oct. 19, pp. 595-599MantleMelts, Subduction
DS1998-1289
1998
Schiano, P.Schiano, P.Low degree partial melts trapped within upper mantle mineralsMineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1334.MantleGlass inclusions
DS1998-1290
1998
Schiano, P.Schiano, P., Bourdon, B., Bottinga, Y.Low degree partial melting trends recorded in upper mantle mineralsEarth and Planetary Science Letters, Vol. 160, No. 3-4, Aug. 1, pp. 537-550.MantleMelt, Magmatism
DS1998-1522
1998
Schiano, P.Varela, M.E., Clochhiatti, R., Massare, D., Schiano, P.Metasomatism in subcontinental mantle beneath Northern Pategonia: evidence from silica rich melt inclusionsMin. Petrol, Vol. 62, No. 1-2, pp. 103-122ArgentinaMetasomatism, Magmatism
DS1999-0628
1999
Schiano, P.Schiano, P., Bourdon, B.On the preservation of mantle information in ultramafic nodules: glass inclusions within minerals versus insterstitial glasses.Earth and Planetary Science Letters, Vol. 169, No. 1-2, May 30, pp. 173-88.MantleGlass, mineralogy
DS1999-0766
1999
Schiano, P.Varela, M.E., Clocchiatti, R., Schiano, P.Silicic glasses in hydrous and anhydrous mantle xenoliths from western Victoria - two different sourcesChemical Geology, Vol. 153, No. 1-4, Jan. pp.151-70.AustraliaXenoliths
DS2000-0207
2000
Schiano, P.David, K., Schiano, P., Allegre, C.J.Assessment of the Zirconium and Hafnium fractionation in oceanic basalts and continental materials during petrogenetic..Earth and Planetary Science Letters, Vol. 178, No. 3-4, May 30, pp. 285-302.GlobalMagmatism, Petrogenesis
DS2003-1220
2003
Schiano, P.Schiano, P.Primitive mantle magmas recorded as silicate melt inclusions in igneous mineralsEarth Science Reviews, Vol. 63, 1-2, pp. 121-144.MantleGeochemistry
DS200412-1249
2004
Schiano, P.Maumus, J., Laporte, D., Schiano, P.Dihedral angle measurements and infiltration property of SIO2 rich melts in mantle peridotite assemblages.Contributions to Mineralogy and Petrology, Vol. 148, 1, pp. 1-12.MantleMineralogy - peridotites
DS200412-1749
2003
Schiano, P.Schiano, P.Primitive mantle magmas recorded as silicate melt inclusions in igneous minerals.Earth Science Reviews, Vol. 63, 1-2, pp. 121-144.MantleGeochemistry
DS200612-0900
2006
Schiano, P.Medard, E., Schmidt, M.W., Schiano, P., Ottolini, L.Melting of amphibole bearing wehrlites: an experimental study on the origin of ultra calcic nepheline normative melts.Journal of Petrology, Vol. 47, 3, pp. 481-504.TechnologyWehrlite
DS200612-0901
2006
Schiano, P.Medard, E., Schmidt, M.W., Schiano, P., Ottolini, L.Melting of amphibole bearing wehrlites: an experimental study on the origin of ultra-calcic nepheline normative melts.Journal of Petrology, Vol. 47, 3, pp. 481-504.TechnologyWehrlite
DS200712-0947
2006
Schiano, P.Schiano, P., Provost, A., Clocchiatti, R., Faure, F.Transcrystalline melt migration and Earth's mantle.Science, Vol. 314, Nov. 10, pp. 970-974.MantleTectonics, volcanism, geothermometry, melting
DS201212-0126
2012
Schiano, P.Chen, Y., Provost, A., Schiano, P., Cluzel, N.Magma ascent rate and initial water concentration inferred from diffusive water loss from olivine hosted melt inclusions.Contributions to Mineralogy and Petrology, in press available 17p.MantleMelting
DS201412-0498
2014
Schiano, P.Laporte, D., Lambart, S., Schiano, P., Ottolini, L.Experimental derivation of nepheline syenite and phonolite liquids by partial melting of upper mantle peridotites.Earth and Planetary Science Letters, Vol. 404, pp. 319-331.MantleMelting
DS201504-0199
2015
Schiano, P.Gannoun, A., Burton, K.W., Barfod, D.N., Schiano, P., Vlastelic, I., Halliday, A.N.Resolving mantle and magmatic processes in basalts from the Cameroon volcanic line using the Re-Os isotopic system.Lithos, Vol. 224-5, pp. 1-12.Africa, CameroonAlkaline rocks, basalts
DS201912-2798
2019
Schiano, P.Laumonier, M., Laporte, D., Faure, F., Provost, A., Schiano, P., Ito, K.An experimental study of dissolution and precipitation of forsterite in a thermal gradient: implications for cellular growth of olivine phenocrysts in basalt and melt inclusion formation.Contributions to Mineralogy and Petrology, Vol. 174, 21p. PdfMantlebasanite

Abstract: The morphology of crystals in magmas strongly depends on the temperature regime of the system, in particular the degree of undercooling and the cooling rate. To simulate low degrees of undercooling, we developed a new experimental setup based on thermal migration, in which large cylinders of forsterite (single crystals) immersed in haplobasaltic melt were subjected to a temperature gradient. As forsterite solubility is sensitive to temperature, the forsterite on the high-temperature side undergoes dissolution and the dissolved components are transported toward the low-temperature side where a layer of newly grown forsterite forms (up to 340 ?m thick after 101 h). A striking feature is that the precipitation process does not produce a planar front of forsterite advancing at the expense of liquid: the growth front shows a fingered outline in planar section, with solid lobes separated by glass tubes that are perpendicular to the growth front. We ascribe this texture to cellular growth, a type of growth that had not been experimentally produced so far in silicate systems. We find that the development of cellular growth requires low degrees of undercooling (a few °C) and large crystal-liquid interfaces (~?1 mm across or more), and that it occurs at a growth rate of the order of 10?9 m/s. We found natural occurrences of cellular growth on the rims of olivines from basanites, but otherwise cellular textures are poorly documented in natural volcanic rocks. Melt inclusions were produced in our experiments, showing that they can form in olivine at relatively slow rates of growth (10?9 m/s or lower).
DS201312-0887
2013
Schiazza, M.Stoppa, F., Schiazza, M.An overview of monogenetic carbonatitic magmatism from Uganda, Italy, Chin a and Spain: volcanologic and geochemical features.Journal of South American Earth Sciences, Vol. 41, pp. 140-159.Africa, Uganda, ChinaCarbonatite
DS201609-1746
2016
Schiazza, M.Stoppa, F., Pirajno, F., Schiazza, M., Vladykin, N.V.State of the art: Italian carbonatites and their potential for critical metal deposits.Gondwana Research, Vol. 37, pp. 152-171.Europe, ItalyRare Earths

Abstract: This paper is an updated overview, including many new data, of what is known about Italian alkaline-carbonatite complexes, plus a new description of a carbothermal residua-related district, and its potential for mineral deposits. The Italian carbonatite occurrences can be divided into two belts. The first is a 350 km long and 75 km wide belt along the Apennines mountain range mainly with primary extrusive carbonatites generally from monogenic volcanoes and from the Vulture volcanic complex; the second belt is 60 km long and 20 km wide in the Northern Latium region in which carbothermal residua carbonatites and fluorite mineralisation deposited by high-temperature fluids rich in CO2, SO2 and fluorine are occurring in caldera volcanoes. Several of the raw materials, such as Light Rare Earth Elements, vanadium, niobium, zirconium, fluorite and phosphate are identified as critical as well as other commodities, occur in Italian carbonatites and alkaline rocks. At the Pianciano quarry (Bracciano) fluorite-rich ore (fluor-ore = fluorite in a mineralised gangue) is actually exploited as flux for cement, but Rare Earth Elements (+ V) could be a notable by-product (300,000 metric tonnes, equivalent to 4.2% of European resources). Pyrochlore, monazite, apatite, and britholite bearing subvolcanic rocks in ejecta from the Vulture volcano are of a near-economic grade, but their geological constraints are not known. A conceptual framework of combined geological and geochemical data improves the general understanding of this regional magmatic system, aimed at laying the foundations of a future geological model disclosing unrecognised potential exploration targets. However, this paper is not intended for direct use by the exploration industry; rather it is principally aimed at mineralogists and petrologists who could develop strategies for the identification of unexposed or unrecognised deposits.
DS201902-0304
2019
Schiazza, M.Nimis, P., Nestola, F., Schiazza, M., Reali, R., Agrosi, G., Mele, D., Tempesta, G., Howell, D., Hutchison, M.T., Spiess, R.Fe-rich ferropericlase and magnesiowustite inclusions reflecting diamond formation rather than ambient mantle.Geology, Vol. 47, 1., pp. 27-30.South America, Brazildeposit - Juina

Abstract: At the core of many Earth-scale processes is the question of what the deep mantle is made of. The only direct samples from such extreme depths are diamonds and their inclusions. It is commonly assumed that these inclusions reflect ambient mantle or are syngenetic with diamond, but these assumptions are rarely tested. We have studied inclusion-host growth relationships in two potentially superdeep diamonds from Juina (Brazil) containing nine inclusions of Fe-rich (XFe ?0.33 to ?0.64) ferropericlase-magnesiowüstite (FM) by X-ray diffractometry, X-ray tomography, cathodoluminescence, electron backscatter diffraction, and electron microprobe analysis. The inclusions share a common [112] zone axis with their diamonds and have their major crystallographic axes within 3°-8° of those of their hosts. This suggests a specific crystallographic orientation relationship (COR) resulting from interfacial energy minimization, disturbed by minor post-entrapment rotation around [112] due to plastic deformation. The observed COR and the relationships between inclusions and diamond growth zones imply that FM nucleated during the growth history of the diamond. Therefore, these inclusions may not provide direct information on the ambient mantle prior to diamond formation. Consequently, a “non-pyrolitic” composition of the lower mantle is not required to explain the occurrence of Fe-rich FM inclusions in diamonds. By identifying examples of mineral inclusions that reflect the local environment of diamond formation and not ambient mantle, we provide both a cautionary tale and a means to test diamond-inclusion time relationships for proper application of inclusion studies to whole-mantle questions.
DS201909-2080
2019
Schiazza, M.Rosatelli, G., Ambrosia, F., Castorina, F., Stoppa, F., Schiazza, M.Mt. Vulture alkaline carbonatite ring complex reconstruction using holocrystalline ejecta.Goldschmidt2019, 1p. AbstractEurope, Italydeposit - Mt. Vulture

Abstract: The Mt. Vulture (Basilicata, Southern Italy) is an alkaline carbonatite volcano whose extrusive rocks are mafic, alkaline with different Na/K ratios, mainly SiO2 undersaturated, with relatively high contents of Cl, S, F, and CO2 [1]. Their composition ranges from basalts to basanites to tephrite to phono-tephrites and phonolites. Along with this magma suite have been erupted mantle xenolith bearing-carbonatitic melilitites and carbonatites [1, 2]. Holocrystalline ejecta have been studied in detail to reconstruct the composition of the subvolcanic/plutonic bodies beneath Mt. Vulture. The ejacta are haüine-bearing clinopyoxenites with variable content of olivine, amphibole and phlogopite, haüine foidolites with some nepheline and leucite, haüine-calcite-syenites, syenites, calcite melilitolites, K-feldspar bering-alvikites and a sovite [3]. There is a continuous variation in the modal and geochemical composition between clinopyroxenite and foidolite, that might be related to the chemical evolution shown by the extrusive rocks. The ejecta show an enrichment trend in LILE, LREE and HFSE consistent with fractional crystallisation evolution, from clinopyroxenites to foidolites and from foid-syenites to syenites. The foid-syeniites are rich in U, Pb, Sr, LREE and contain britholite, wholerite, Upyrochlore. The most evolved syenite however, is less enriched in REE but contains elevate content of U and HFSE. The sovite contains intercumulus alkali carbonates. A glimemerite vein in a haüine foidolite contain REE-rich apatite, shorlomite and U-pyrochlore. These findings suggest that alkaline-alogen-H2O-CO2 rich fluids can be formed during sub-volcanic/plutonic fractional crystallisation. These fluids can produce fenitisation and/or can form mineralisation enriched in REE and HFSE. The ejecta suite studied represents the intrusive complex beneath the volcano and these rock types are typical of ring complexes in alkaline carbonatite volcanoes.
DS201909-2092
2019
Schiazza, M.Stoppa, F., Schiazza, M., Rosatelli, G., Castorina, F., Sharygin, V.V., Ambrosio, A., Vicentini, N.Italian carbonatite system: from mantle to ore deposit.Ore Geology Reviews, in press available, 59p. PdfEurope, Italycarbonatite

Abstract: A new discovery of carbonatites at Pianciano, Ficoreto and Forcinelle in the Roman Region demonstrates that Italian carbonatites are not just isolated, mantle xenoliths-bearing, primitive diatremic rocks but also evolved sub-type fluor-calciocarbonatite (F?10 wt.%) associated with fluor ore (F?30 wt.%). New data constrain a multi-stage petrogenetic process, 1-orthomagmatic, 2-carbothermal, 3-hydrothermal. Petrography and geochemistry are conducive to processes of immiscibility and decarbonation, rather than assimilation and crystal fractionation. A CO2-rich, ultra-alkaline magma is inferred to produce immiscible melilite leucitite and carbonatite melts, at lithospheric mantle depths. At the crustal level and in the presence of massive CO2 exsolution, decarbonation reactions may be the dominant processes. Decarbonation consumes dolomite and produces calcite and periclase, which, in turn, react with silica to produce forsterite and Ca silicates (monticellite, melilite, andradite). Under carbothermal conditions, carbonate breakdown releases Sr, Ba and LREE; F and S become concentrated in residual fluids, allowing precipitation of fluorite and barite, as well as celestine and anhydrite. Fluor-calciocarbonatite is the best candidate to exsolve fluids able to deposit fluor ore, which has a smaller volume. At the hydrothermal stage, REE concentration and temperature dropping allow the formation of LREEF2+ and LREECO3+ ligands, which control the precipitation of interstitial LREE fluorcarbonate and silicates -(bastnäsite-(Ce)- Ce(CO3)F and -britholite-(Ce)- (Ce,Ca)5(SiO4,PO4)3(OH,F) . Vanadates such as wakefieldite, CeVO4, vanadinite, Pb5(VO4)3Cl and coronadite Pb(Mn4+6 Mn3+2)O16 characterise the matrix. At temperatures of ?100°C analcime, halloysite, quartz, barren calcite, and zeolites (K-Ca) precipitate in expansion fractures, veins and dyke aureoles.
DS201911-2566
2019
Schiazza, M.Stoppa, F., Schiazza, M., Rosatelli, G., Castorina, F., Sharygin, V.V., Ambrosio, F.A., Vicentini, N.Italian carbonatite system: from mantle to ore deposit.Ore Geology Reviews, Vol. 114, 17p. PdfEurope, Italycarbonatite

Abstract: A new discovery of carbonatites at Pianciano, Ficoreto and Forcinelle in the Roman Region demonstrates that Italian carbonatites are not just isolated, mantle xenoliths-bearing, primitive diatremic rocks but also evolved sub-type fluor-calciocarbonatite (F~10 wt.%) associated with fluor ore (F~30 wt.%). New data constrain a multi-stage petrogenetic process, 1-orthomagmatic, 2-carbothermal, 3-hydrothermal. Petrography and geochemistry are conducive to processes of immiscibility and decarbonation, rather than assimilation and crystal fractionation. A CO2-rich, ultra-alkaline magma is inferred to produce immiscible melilite leucitite and carbonatite melts, at lithospheric mantle depths. At the crustal level and in the presence of massive CO2 exsolution, decarbonation reactions may be the dominant processes. Decarbonation consumes dolomite and produces calcite and periclase, which, in turn, react with silica to produce forsterite and Ca silicates (monticellite, melilite, andradite). Under carbothermal conditions, carbonate breakdown releases Sr, Ba and LREE; F and S become concentrated in residual fluids, allowing precipitation of fluorite and barite, as well as celestine and anhydrite. Fluor-calciocarbonatite is the best candidate to exsolve fluids able to deposit fluor ore, which has a smaller volume. At the hydrothermal stage, REE concentration and temperature dropping allow the formation of LREEF2+ and LREECO3+ ligands, which control the precipitation of interstitial LREE fluorcarbonate and silicates -(bastnäsite-(Ce)- Ce(CO3)F and -britholite-(Ce)- (Ce,Ca)5(SiO4,PO4)3(OH,F) . Vanadates such as wakefieldite, CeVO4, vanadinite, Pb5(VO4)3Cl and coronadite Pb(Mn4+6 Mn3+2)O16 characterise the matrix. At temperatures of =100°C analcime, halloysite, quartz, barren calcite, and zeolites (K-Ca) precipitate in expansion fractures, veins and dyke aureoles.
DS200712-0948
2007
Schich, S.R.Schich, S.R., Duffy, T.S., Liu, Z., Ohtani, E.The hydrogen within the deep mantle.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p.153.MantleHydrogen budget
DS200712-0949
2007
Schich, S.R.Schich, S.R., Duffy, T.S., Liu, Z., Ohtani, E.The hydrogen within the deep mantle.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p.153.MantleHydrogen budget
DS1993-1390
1993
Schidlowski, M.Schidlowski, M.Proterozoic carbon cycle discussion and replyNature, Vol. 362, m March 11, pp. 117-118GlobalCarbon cycle, Proterozoic
DS1998-1479
1998
Schidlowski, M.Toulkeridis, T., Goldstein, S.L., Schidlowski, M.Samarium-neodymium, Rubidium-Strontium,and lead-lead dating of silicic carbonates from early Archean Barberton greenstone belt: evidence..Precambrian Research, Vol. 92, No. 2, Oct.l, pp. 129-44South AfricaGeochronology - post depositional resetting, Low temperature
DS1989-1351
1989
Schiebe, L.F.Schiebe, L.F., Formoso, M.L.L., Nardi, L.V.S., Hartmann, L.A.Geochemistry of rare earth elements of alkalic rocks,carbonatites and kimberlite rocks; study of Brazilianoccurrence.(in Portugese).In: Geochemistry of rare earth elements in Brasil, Co. Pesqui Rec. Miner., pp. 37-46BrazilAlkaline rocks, Kimberlites -geochemistry
DS201112-0089
2011
Schieber, J.Bickford, M.E., Basu, A., Patranabis-Deb, S.,Dhang, P.C., Schieber, J.Depositional history of the Chhattisgarh Basin, central India; constraints frpm New SHRIMP zircon ages.Journal of Geology, Vol. 119, 1, Jan. pp. 33-50.IndiaGeochronology
DS1982-0542
1982
Schieffer, J.H.Schieffer, J.H.Nature and Origin of Alkalic and Calcic Veinlets in Xenoliths from the Terlingua District, West Texas.Geological Society of America (GSA), Vol. 14, No. 7, P. 609, (abstract.).GlobalKimberlite, Rocky Mountains, Lherzolite, Harzburgite
DS200912-0634
2008
Schiellerup, H.Robinson, P., Solli, A., Engvik, A., Erambert, M., Bingen, B., Schiellerup, H., Njange, F.Solid solution between potassic obertitie and potassic fluoro magnesio arfvedsonite in a silica rich lamproite from northeast Mozambique.European Journal of Mineralogy, Vol. 20, 6, pp. 1011-1018.Africa, MozambiqueLamproite
DS201112-0923
2011
Schiemenz, A.Schiemenz, A., Liang, Y., Parmentier, E.M.A high order numerical study of reactive dissolution in an upwelling heterogeneous mantle: 1. channelization, channel lithology and channel geometry.Geophysical Journal International, In press availableMantleChemistry
DS1986-0708
1986
Schier, D.Schier, D., Jagoutz, E.Cerium isotopes- new aspects for kimberlite genesis by a newisotopicsystemProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 318-319South AfricaBlank
DS1900-0038
1900
Schiff, F.Schiff, F.L'industrie Diamantifere Au CapGenie Civil, Vol. 37, PP. 287-291.Africa, South AfricaMining Engineering
DS201602-0235
2015
Schiffer, C.Schiffer, C., Stephenson, R.A., Petersen, K.D., Nielsen, S.B., Jacobsen, B.H., Balling, N., Macdonald, D.I.M.A sub crustal piercing point for North Atlantic reconstructions and tectonic implications.Geology, Vol. 43, 12, pp. 1087-1090.Europe, GreenlandPlate Tectonics

Abstract: Plate tectonic reconstructions are usually constrained by the correlation of lineaments of surface geology and crustal structures. This procedure is, however, largely dependent on and complicated by assumptions on crustal structure and thinning and the identification of the continent-ocean transition. We identify two geophysically and geometrically similar upper mantle structures in the North Atlantic and suggest that these represent remnants of the same Caledonian collision event. The identification of this structural lineament provides a sub-crustal piercing point and hence a novel opportunity to tie plate tectonic reconstructions. Further, this structure coincides with the location of some major tectonic events of the North Atlantic post-orogenic evolution such as the occurrence of the Iceland Melt Anomaly and the separation of the Jan Mayen microcontinent. We suggest that this inherited orogenic structure played a major role in the control of North Atlantic tectonic processes.
DS201607-1313
2016
Schiffer, C.Schiffer, C., Nielsen, S.B.Implications for anomalous mantle pressure and dynamic topography from lithospheric stress patterns in the North Atlantic Realm.Journal of Geodynamics, Vol. 98, pp. 53-69.Canada, NorwayGeophysics - seismics

Abstract: With convergent plate boundaries at some distance, the sources of the lithospheric stress field of the North Atlantic Realm are mainly mantle tractions at the base of the lithosphere, lithospheric density structure and topography. Given this, we estimate horizontal deviatoric stresses using a well-established thin sheet model in a global finite element representation. We adjust the lithospheric thickness and the sub-lithospheric pressure iteratively, comparing modelled in plane stress with the observations of the World Stress Map. We find that an anomalous mantle pressure associated with the Iceland and Azores melt anomalies, as well as topography are able to explain the general pattern of the principle horizontal stress directions. The Iceland melt anomaly overprints the classic ridge push perpendicular to the Mid Atlantic ridge and affects the conjugate passive margins in East Greenland more than in western Scandinavia. The dynamic support of topography shows a distinct maximum of c. 1000 m in Iceland and amounts <150 m along the coast of south-western Norway and 250 -350 m along the coast of East Greenland. Considering that large areas of the North Atlantic Realm have been estimated to be sub-aerial during the time of break-up, two components of dynamic topography seem to have affected the area: a short-lived, which affected a wider area along the rift system and quickly dissipated after break-up, and a more durable in the close vicinity of Iceland. This is consistent with the appearance of a buoyancy anomaly at the base of the North Atlantic lithosphere at or slightly before continental breakup, relatively fast dissipation of the fringes of this, and continued melt generation below Iceland.
DS1988-0104
1988
Schiffmacher, E.R.Campbell, W.H., Schiffmacher, E.R.Upper mantle electrical conductivity for seven subcontinental regions Of the earthJournal of Geomagnetism and Geoelectricity, Vol. 40, No. 11, pp. 1387-1406GlobalMantle, Geophysics
DS1983-0479
1983
Schiffman, P.Neville, S.L., Schiffman, P., Sadler, P.M.New Discoveries of Spinel Lherzolite and Garnet Websterite Nodules in Alkaline Basalts from the South Central Ranges Ofcalifornia.Geological Society of America (GSA), Vol. 15, No. 5, P. 302. (abstract.).United States, California, West CoastMineralogy
DS1985-0490
1985
Schiffman, P.Neville, S.L., Schiffman, P., Sadler, P.Ultramafic Inclusions in Late Miocene Alkaline Basalts From fry and Ruby Mountains, San Bernardino County, California.American MINERALOGIST., Vol. 70, No. 7-8, PP. 668-677.United States, West Coast, CaliforniaWebsterite, Lherzolite, Harzburgite
DS2003-0655
2003
Schifth, F.Jensen, S.M., Secher, K., Rasmussen, T.M., Tukiainen, T., Krebs, J.D., Schifth, F.Distribution and magnetic signatures of kimberlitic rocks in the Sarfartoq region8 Ikc Www.venuewest.com/8ikc/program.htm, Session 8, POSTER abstractGreenlandBlank
DS200412-0914
2003
Schifth, F.Jensen, S.M., Secher, K., Rasmussen, T.M., Tukiainen, T., Krebs, J.D., Schifth, F.Distribution and magnetic signatures of kimberlitic rocks in the Sarfartoq region, southern West Greenland.8 IKC Program, Session 8, POSTER abstractEurope, GreenlandDiamond exploration
DS2001-1019
2001
Schijf, J.Savov, I., Ryan, J., Haydoutov, I., Schijf, J.Late Precambrian Balkan Carpathian ophiolite - a slice of the Pan African ocean crust? geochemical, tectonicsJour. Volc. Geotherm. Res., Vol. 110, No.3-4, pp. 299-318.Bulgaria, SyriaOphiolite, Massifs - Tcherni Vrah, Deli Jovan
DS201603-0425
2015
Schildgen, T.F.Terra Acosta, V., Bande, A., Sobel, E.R., Parra, M., Schildgen, T.F., Stuart, F., Strecker, M.R. .Cenozoic extension in the Kenya Rift from low temperature thermochronology: links to diachronous spaciotemporal evolution of rifting in East Africa.Tectonics, Vol. 34, 12, pp. 2367-2388.Africa, KenyaRifting

Abstract: The cooling history of rift shoulders and the subsidence history of rift basins are cornerstones for reconstructing the morphotectonic evolution of extensional geodynamic provinces, assessing their role in paleoenvironmental changes and evaluating the resource potential of their basin fills. Our apatite fission track and zircon (U-Th)/He data from the Samburu Hills and the Elgeyo Escarpment in the northern and central sectors of the Kenya Rift indicate a broadly consistent thermal evolution of both regions. Results of thermal modeling support a three-phased thermal history since the early Paleocene. The first phase (~65 50?Ma) was characterized by rapid cooling of the rift shoulders and may be coeval with faulting and sedimentation in the Anza Rift basin, now located in the subsurface of the Turkana depression and areas to the east in northern Kenya. In the second phase, very slow cooling or slight reheating occurred between ~45 and 15?Ma as a result of either stable surface conditions, very slow exhumation, or subsidence. The third phase comprised renewed rapid cooling starting at ~15?Ma. This final cooling represents the most recent stage of rifting, which followed widespread flood-phonolite emplacement and has shaped the present-day landscape through rift shoulder uplift, faulting, basin filling, protracted volcanism, and erosion. When compared with thermochronologic and geologic data from other sectors of the East African Rift System, extension appears to be diachronous, spatially disparate, and partly overlapping, likely driven by interactions between mantle-driven processes and crustal heterogeneities, rather than the previously suggested north south migrating influence of a mantle plume.
DS1994-1544
1994
Schiller, E.Schiller, E., Chartier, T.The Yamba Lake joint venture, Mill City, Fibre CladThe Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Section Meeting Oct. 12, Vancouver, p. 64. abstractNorthwest TerritoriesUpdate on JV
DS2003-1221
2003
Schiller, E.Schiller, E.Who will be the first victor on Victoria Island?Resources World, February pp. 17-19.Northwest Territories, Victoria IslandNews item
DS2003-1222
2003
Schiller, E.Schiller, E.Quebec: the quick fix to Ashton success?Resources World, February pp. 21-22.QuebecNews item, Ashton Mining of Canada Ltd.
DS200412-1750
2004
Schiller, E.Schiller, E.Do diamonds prefer the Arctic?Resource World Magazine, Vol. 2, 5, July/August pp. 21.Canada, Nunavut, Melville PeninsulaNews item - overview
DS200412-1751
2003
Schiller, E.Schiller, E.Saskatchewan diamonds.Resource World Magazine, No. 8, pp. 25-27.Canada, SaskatchewanNews item - Shore Gold
DS201412-0777
2014
Schiller, E.Schiller, E.NWT diamond developments. ( originally appeared in Resource World in Dec 2013)Idex Magazine, No. 286, Feb. pp. 118-121.Canada, Northwest TerritoriesHistory and brief overview
DS201607-1314
2016
Schiller, E.Schiller, E.Diamonds in Canada: a major world producer. Canada has more mines under development and promising exploration projects.Resource World Magazine, Feb 8, 5p.CanadaDiamond production, future mines
DS1990-1310
1990
Schiller, E.A.Schiller, E.A.Geological Society of Canada (GSC) releases diamond exploration manualProspectors and Developers Association of Canada (PDAC) Digest, Summer 1990, pp. 15, 16CanadaExploration, Diamond prospecting -sumM.
DS1992-1340
1992
Schiller, E.A.Schiller, E.A.Diamond exploration in western Canada #2Prospectors and Developers Association of Canada (PDAC) Digest, Vol. 5, No. 27, p. 1, 2, 3British Columbia, Saskatchewan, Alberta, Northwest TerritoriesNews item, Brief overview
DS1993-0180
1993
Schiller, E.A.Buckle, J.E., Chartier, T., Schiller, E.A.Discovery of the Yamba Lake, Northwest Territories, kimberlites with integrated geophysical and geochemical methods. #2Northwest Territories Exploration Overview for 1993, November pp. 25-26.Northwest TerritoriesGeophysics, Yamba Lake
DS1993-0181
1993
Schiller, E.A.Buckle, J.E., Chartier, T., Schiller, E.A.Discovery of the Yamba Lake, Northwest Territories, kimberlites with integrated geophysical and geochemical methods. #1Northwest Territories Geoscience Forum preprint, 16p.Northwest TerritoriesNews item, Tanqueray Exploration activity
DS1993-1391
1993
Schiller, E.A.Schiller, E.A.Diabase dikes and kimberlites - a new link to diamonds?The Canadian Mining and Metallurgical Bulletin (CIM Bulletin) , Annual Meeting Abstracts approximately 10 lines, Vol. 86, No. 968, March ABSTRACT p. 71.Northwest TerritoriesCraton, Tectonics
DS1994-1545
1994
Schiller, E.A.Schiller, E.A., Chartier, T.A.The Yamba Lake joint venture -Tanqueray Resources and Mill City Gold MiningCorp.The Canadian Institute of Mining, Metallurgy and Petroleum (CIM) District 6, Oct. 11-15th. Vancouver, p.64 abstract onlyNorthwest TerritoriesHistory
DS1998-1291
1998
Schiller, E.P.Schiller, E.P.Metallic and industrial mineral assessment report on the Jack Pine Creek area, Buffalo Hills region.Alberta Geological Survey, MIN 19980011Alberta, NorthwesternExploration - assessment, Absolut Resources Corp.
DS200812-0446
2008
Schiller, M.Handler, M.R., Baker, J.A., Schiller, M., Bennett, V.C., Yaxley, G.M.Stable Mg isotope composition of Earth's mantle,Goldschmidt Conference 2008, Abstract p.A348.MantleGeochronology
DS1997-1004
1997
Schilling, F.R.Schmitz, M., Heinsohn, W.D., Schilling, F.R.Seismic gravity and petrological evidence for partial melt beneath the thickened Central Andean crustTectonophysics, Vol. 270, No. 3-4, March 15, pp. 313-South America, Bolivia, Chile, Brazil, AndesGeophysics - seismic, Mantle melt
DS2001-1027
2001
Schilling, F.R.Schilling, F.R., Hauser, M., Sinogeikin, S.V., Bass, J.Compositional dependence of elastic properties and density of glasses system anorthite diopside forsteriteContributions to Mineralogy and Petrology, Vol. 141, pp. 297-306.MantleMelting - silicate melts, migration
DS2002-1108
2002
Schilling, F.R.Muller, H.J., Schilling, F.R., Lauterjung, J.In situ investigation of physical properties of rocks and minerals at lower crustal and mantle conditions - methods, measurements, challenges.Zeitschrift fur Geologische Wissenschaften, Vol.30,1-2,pp.49-76.MantleMetasomatism
DS2003-1247
2003
Schilling, F.R.Seipold, U., Schilling, F.R.Heat transport in serpentinitesTectonophysics, Vol. 370, 1-4, pp. 147-162.GlobalGeothermometry
DS200412-1783
2003
Schilling, F.R.Seipold, U., Schilling, F.R.Heat transport in serpentinites.Tectonophysics, Vol. 370, 1-4, pp. 147-162.TechnologyGeothermometry
DS201112-0645
2011
Schilling, J.Marks, M.A.W., Hettmann, K., Schilling, J., Frost, B.R., Markl, G.The mineralogical diversity of alkaline igneous rocks: critical factors for the transition from miaskitic to agpaitic phase assemblages.Journal of Petrology, Vol. 52, 3, pp. 439-455.Alkalic
DS201112-0924
2011
Schilling, J.Schilling, J., Marks, m.A.W., Wenzel, T., Vennenmann, T., Horvth, L., Tarassof, P., Jacob, D.E., Markl, G.The magmatic to hydrothermal evolution of the intrusive Mont Sainte Hilaire Complex: insights into the late stage evolution of peralkaline rocks.Journal of Petrology, Vol. 52, 11. pp. 2147-2185.Canada, QuebecAlkaline rocks, carbonatite
DS1980-0263
1980
Schilling, J.G.Ogden, P.R.JR., Vollmer, R., Schilling, J.G.Leucite Hills Revisited 87/sr and 86/sr EvidenceEos, Vol. 61, No. 17, P. 388, (abstract.).GlobalLeucite Hills, Leucite, Rocky Mountains
DS1984-0752
1984
Schilling, J.G.Vollmer, R., Ogden, P., Schilling, J.G., Kingsley, R.H.Neodymium and Strontium Isotopes in the Ultrapotassic Volcanic Rocks from the Leucite Hills, Wyoming.Contributions to Mineralogy and Petrology, Vol. 87, No. 4, PP. 359-368.United States, Wyoming, Leucite HillsGeochronology
DS2002-0928
2002
Schilling, J.G.Le Roux, P.J., Le Roex, A.P., Schilling, J.G., Shimizu, N., Perkins, W.W., PearceMantle heterogeneity beneath the southern Mid-Atlantic Ridge: trace element evidenceEarth and Planetary Science Letters, Vol. 203, 1, pp. 479-98.MantleGeochemistry
DS200712-0408
2007
Schilling, J-G.Hana, B.B., Blichert-Toft, J., Kingsley, R.H., Schilling, J-G.Source origin of the ultrapotassic lavas from the Leucite Hills, Wyoming: Hf isotope constraints.Plates, Plumes, and Paradigms, 1p. abstract p. A375.United States, Wyoming, Colorado PlateauLamproite
DS201610-1877
2016
Schilling, J-G.Kamenetsky, V.S., Maas, R., Kamenetsky, M.B., Yaxley, G.M., Ehrig, K., Zellmer, G.F., Bindeman, I.N., Sobolev, A.V., Kuzmin, D.V., Ivanov, A.V., Woodhead, J., Schilling, J-G.Multiple mantle sources of continental magmatism: insights from "high-Ti" picrites of Karoo and other large igneous provinces.Chemical Geology, in press available 10p.Africa, South AfricaLIP magmatism

Abstract: Magmas forming large igneous provinces (LIP) on continents are generated by extensive melting in the deep crust and underlying mantle and associated with break-up of ancient supercontinents, followed by formation of a new basaltic crust in the mid-oceanic rifts. A lack of the unifying model in understanding the sources of LIP magmatism is justified by lithological and geochemical complexity of erupted magmas on local (e.g. a cross-section) and regional (a single and different LIP) scales. Moreover, the majority of LIP rocks do not fit general criteria for recognizing primary/primitive melts (i.e. < 8 wt% MgO and absence of high-Fo olivine phenocrysts). This study presents the mineralogical (olivine, Cr-spinel, orthopyroxene), geochemical (trace elements and Sr-Nd-Hf-Pb isotopes) and olivine-hosted melt inclusion compositional characteristics of a single primitive (16 wt% MgO), high-Ti (2.5 wt% TiO2) picrite with high-Mg olivine (up to 91 mol% Fo) from the Letaba Formation in the ~ 180 Ma Karoo LIP (south Africa). The olivine compositions (unusually high ?18O (6.17‰), high NiO (0.36-0.56 wt%) and low MnO and CaO (0.12-0.20 and 0.12-0.22 wt%, respectively)) are used to argue for a non-peridotitic mantle source. This is supported by the enrichment of the rock and melts in most incompatible trace elements and depletion in heavy rare earth elements (e.g. high Gd/Yb) that reflects residual garnet in the source of melting. The radiogenic isotopes resemble those of the model enriched mantle (EM-1) and further argue for a long-term enrichment of the source in incompatible trace elements. The enriched high-Ti compositions, strongly fractionated incompatible trace elements, presence of primitive olivine and high-Cr spinel in the Letaba picrites are closely matched by olivine-phyric rocks from the ~ 260 Ma Emeishan (Yongsheng area, SW China) and ~ 250 Ma Siberian (Maimecha-Kotuy region, N Siberia) LIPs. However, many other compositional parameters (e.g. trace element and ?18O compositions of olivine phenocrysts, Fe2 +/Fe3 + in Cr-spinel, Sr-Nd-Hf isotope ratios) only partially overlap or even diverge. We thus imply that parental melts of enriched picritic rocks with forsteritic olivine from three major continental igneous provinces - Karoo, Emeishan and Siberia cannot be assigned to a common mantle source and similar melting conditions. The Karoo picrites also exhibit some mineralogical and geochemical similarities with rocks and glasses in the south Atlantic Ridge and adjacent fracture zones. The geodynamic reconstructions of the continental plate motions since break-up of the Gondwanaland in the Jurassic support the current position of the source of the Karoo magmatism in the southernmost Atlantic. Co-occurrence of modern and recent anomalous rocks with normal mid-ocean ridge basalts in this region can be related to blocks/rafts of the ancient lithosphere, stranded in the ambient upper mantle and occasionally sampled by rifting-related decompressional melting.
DS201707-1337
2017
Schilling, J-G.Kamenetsky, V.S., Maas, R., Kamenetsky, M.B., Yaxley, G.M., Ehrig, K., Zellmer, G.F., Bindeman, I.N., Sobolev, A.V., Kuzmin, D.V., Ivanov, A.V., Woodhead, J., Schilling, J-G.Multiple mantle sources of continental magmatism: insights from high Ti picrites of Karoo and other large igneous provinces.Chemical Geology, Vol. 455, pp. 22-31.Africa, South Africamagmatism

Abstract: Magmas forming large igneous provinces (LIP) on continents are generated by extensive melting in the deep crust and underlying mantle and associated with break-up of ancient supercontinents, followed by formation of a new basaltic crust in the mid-oceanic rifts. A lack of the unifying model in understanding the sources of LIP magmatism is justified by lithological and geochemical complexity of erupted magmas on local (e.g. a cross-section) and regional (a single and different LIP) scales. Moreover, the majority of LIP rocks do not fit general criteria for recognizing primary/primitive melts (i.e. < 8 wt% MgO and absence of high-Fo olivine phenocrysts). This study presents the mineralogical (olivine, Cr-spinel, orthopyroxene), geochemical (trace elements and Sr-Nd-Hf-Pb isotopes) and olivine-hosted melt inclusion compositional characteristics of a single primitive (16 wt% MgO), high-Ti (2.5 wt% TiO2) picrite with high-Mg olivine (up to 91 mol% Fo) from the Letaba Formation in the ~ 180 Ma Karoo LIP (south Africa). The olivine compositions (unusually high ?18O (6.17‰), high NiO (0.36–0.56 wt%) and low MnO and CaO (0.12–0.20 and 0.12–0.22 wt%, respectively)) are used to argue for a non-peridotitic mantle source. This is supported by the enrichment of the rock and melts in most incompatible trace elements and depletion in heavy rare earth elements (e.g. high Gd/Yb) that reflects residual garnet in the source of melting. The radiogenic isotopes resemble those of the model enriched mantle (EM-1) and further argue for a long-term enrichment of the source in incompatible trace elements. The enriched high-Ti compositions, strongly fractionated incompatible trace elements, presence of primitive olivine and high-Cr spinel in the Letaba picrites are closely matched by olivine-phyric rocks from the ~ 260 Ma Emeishan (Yongsheng area, SW China) and ~ 250 Ma Siberian (Maimecha-Kotuy region, N Siberia) LIPs. However, many other compositional parameters (e.g. trace element and ?18O compositions of olivine phenocrysts, Fe2 +/Fe3 + in Cr-spinel, Sr-Nd-Hf isotope ratios) only partially overlap or even diverge. We thus imply that parental melts of enriched picritic rocks with forsteritic olivine from three major continental igneous provinces – Karoo, Emeishan and Siberia cannot be assigned to a common mantle source and similar melting conditions. The Karoo picrites also exhibit some mineralogical and geochemical similarities with rocks and glasses in the south Atlantic Ridge and adjacent fracture zones. The geodynamic reconstructions of the continental plate motions since break-up of the Gondwanaland in the Jurassic support the current position of the source of the Karoo magmatism in the southernmost Atlantic. Co-occurrence of modern and recent anomalous rocks with normal mid-ocean ridge basalts in this region can be related to blocks/rafts of the ancient lithosphere, stranded in the ambient upper mantle and occasionally sampled by rifting-related decompressional melting.
DS202008-1396
2020
Schilling, M.Gonzales-Jiminez, J.M., Tassara, S., Schettino, E., Roque-Rosell, J., Farre-de-Pablo, J., Saunders, J.E., Deditius, A.P., Colas, V., Rovira-Medina, J.J., Guadalupe Davalos, M., Schilling, M., Jiminez-Franco, A., Marchesi, C., Nieto, F., Proenza, J.A., GerMineralogy of the HSE in the subcontinental lithospheric mantle - an interpretive review.Lithos, in press available, 44p. PdfMantleHSE

Abstract: The highly siderophile elements (HSE: Os, Ir, Ru, Rh, Pt, Pd, Re, Au) exist in solid solution in accessory base-metal sulfides (BMS) as well as nano-to-micron scale minerals in rocks of the subcontinental lithospheric mantle (SCLM). The latter include platinum-group minerals (PGM) and gold minerals, which may vary widely in morphology, composition and distribution. The PGM form isolated grains often associated with larger BMS hosted in residual olivine, located at interstices in between peridotite-forming minerals or more commonly in association with metasomatic minerals (pyroxenes, carbonates, phosphates) and silicate glasses in some peridotite xenoliths. The PGM found inside residual olivine are mainly Os-, Ir- and Ru-rich sulfides and alloys. In contrast, those associated with metasomatic minerals or silicate glasses of peridotite xenoliths consist of Pt, Pd, and Rh bonded with semimetals like As, Te, Bi, and Sn. Nanoscale observations on natural samples along with the results of recent experiments indicate that nucleation of PGM is mainly related with the uptake of HSE by nanoparticles, nanominerals or nanomelts at high temperature (> 900?°C) in both silicate and/or sulfide melts, regardless of the residual or metasomatic origin of their host minerals. A similar interpretation can be assumed for gold minerals. Our observations highlight that nanoscale processes play an important role on the ore-forming potential of primitive mantle-derived magmas parental to magmatic-hydrothermal deposits enriched in noble metals. The metal inventory in these magmas could be related with the physical incorporation of HSE-bearing nanoparticles or nanomelts during processes of partial melting of mantle peridotite and melt migration from the mantle to overlying continental crust.
DS200812-1016
2008
Schilling, M.E.Schilling, M.E., Carlson, R.W., Viveira Conceicao, R., Dantas, Bertotto, KoesterRe-Os isotope contraints on subcontinental lithosphere mantle evolution of southern South America.Earth and Planetary Science Letters, Vol. 268, 1-2, April 15, pp. 89-101.South America, RodiniaGeochronology - xenoliths
DS1989-1352
1989
Schilling, S.P.Schilling, S.P., Thompson, R.A.Color Palette: plotting guide for use with GSMAP and GSDRAW digital cartographic softwareUnited States Geological Survey (USGS) Open File, No. 88-553A, 11p. B discGlobalComputer, Program -Color palette
DS1991-1514
1991
Schilling, S.P.Schilling, S.P.GEOTRANS: an interface program from GEOPROGRAM to a geographic informationsystemUnited States Geological Survey (USGS) Open File, No. 90-0615, 86p. $ 14.00GlobalComputer, Program -GEOTRANS
DS2000-0752
2000
Schimann, K.Pell, J., Schimann, K.Prospecting for kimberlites in peritropical regions using heavy minerals: a case study from Aredor concess.Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) Calgary May 2000, 4p.GuineaLateritic environments, saprolite, case history, Deposit - K23
DS200412-0069
2004
Schimmel, M.Assumpcao, M., Schimmel, M., Escalante, C., Barbosa, J.R., Rocha, M., Barros, L.V.Intraplate seismicity in SE Brazil: stress concentration in lithospheric thin spots.Geophysical Journal International, Vol. 159, 1, pp. 390-399.South America, BrazilGeophysics - seismics
DS201312-0556
2013
Schimmel, M.Luciana, B., Schimmel, M., Gallart, J., Morales, J.Studying the 410-km and 660-km discontinuities beneath Spain and Morocco through detection of P-to-s conversions.Geophysical Journal International, Vol. 194, 2, pp. 920-935.Europe, Spain, Africa, MoroccoGeophysics -
DS201212-0394
2012
Schinao, P.Lambart, S., Laporte, D., Provost, A., Schinao, P.Fate of pyroxenite derived melts in the periodotitic mantle: thermodynamic and experimental constraints.Journal of Petrology, Vol 53, 3, pp. 451-476.MantlePeridotite
DS200912-0273
2009
Schincka, H-U.Gurenko, A.A., Sobolev, A.V., Hoernle, K.A., Hauff, F., Schincka, H-U.Enriched, HIMU type peridotite and depleted recycled pyroxenite in the Canary plume: a mixed up mantle.Earth and Planetary Science Letters, Vol. 277, 3-4, Jan. 30, pp. 514-524.Europe, Canary IslandsGeothermometry - subduction
DS1999-0629
1999
Schindler, D.W.Schindler, D.W.Carbon cycling: the mysterious missing sinkNature, Vol. 398, No. 6723, Mar. 11, pp. 105-6.GlobalCarbon, Geochemistry
DS2002-0380
2002
Schindler, U.Diepenbroek, M., Grobe, H., Reinke, M., Schindler, U., SchlitzerPANGEA - an information system for environmental sciencesComputers and Geosciences, Vol. 28, 10, pp.1201-10.GlobalComputers - programs
DS2001-1028
2001
Schingaro, E.Schingaro, E., Scaordani, Malitesta, Rudolf, LouetteXPS investigation on natural Ti bearing garnetsPlinius, No. 24, p. 195. abstractGlobalMineralogy - garnet
DS201212-0392
2012
Schingaro, E.Lacamita, M., Mesto, E., Scordari, F., Schingaro, E.Chemical and structural study of 1M and 2M1 phlogopites coexisting in the same Kaseny kamafugitic rock ( SW Uganda).Physics and Chemistry of Minerals, Vol. 39, 8, pp. 601-611.Africa, UgandaKamafugite
DS201412-0778
2014
Schingaro, E.Schingaro, E., Kullerud, K., Lacalamita, M., Mesto, E., Scordari, F., Zozulya, D., Erambert, M., Ravna, E.J.K.Yangzhumgite and phlogopite from the Kvaloya lamproite ( North Norway): structure, composition and origin.Lithos, Vol. 210-211, pp. 1-13.Europe, NorwayLamproite
DS201502-0096
2014
Schingaro, E.Schingaro, E., Kullerud, K., laclamita, M., Mesto, E., Scordari, F., Zozulya, D., Erambert, M., Ravna, E.J.K.Yangzhumingite and phlogopite from the Kvaloya lamproite (North Norway): structure, composition and origin.Lithos, Vol. 210-211, pp. 1-13.Europe, NorwayLamproite
DS1860-0714
1891
Schinz, H.Schinz, H.Deutsch Sued West AfrikaForschungreisen Durch Die Deutschen Schutzgebiete Gross Nama, 568P.Africa, Southwest Africa, NamibiaTravelogue
DS1989-1353
1989
Schiotte, L.Schiotte, L., Compston, W., Bridgewater, D.Ion probe uranium-thorium-lead-zircon dating of polymetamorphic orthogneisses from northern Labrador.Canadian Journal of Earth Sciences, Vol. 26, pp. 1533-56.Labrador, QuebecGeochronology
DS1989-1354
1989
Schiotte, L.Schiotte, L., Compston, W., Bridgewater, D.Uranium-thorium-lead ages of single zircons in Archean supracrustals from Nain Labrador.Canadian Journal of Earth Sciences, Vol. 26, pp. 2636-44.Labrador, QuebecGeochronology
DS202003-0338
2020
Schiperski, F.Franz, G., Vyshnevsky, O., Taran, M., Khomenko, V., Wiedenbeck, M., Schiperski, F., Nissen, J.A new emerald occurrence from Kruta Balka, western Peri-Azovian, Ukraine: implications for understanding the crystal chemistry of emerald.American Mineralogist, Vol. 105, pp. 162-181. pdfEurope, Ukraineemerald

Abstract: We investigated emerald, the bright-green gem variety of beryl, from a new locality at Kruta Balka, Ukraine, and compare its chemical characteristics with those of emeralds from selected occurrences worldwide (Austria, Australia, Colombia, South Africa, Russia) to clarify the types and amounts of substitutions as well as the factors controlling such substitutions. For selected crystals, Be and Li were determined by secondary ion mass spectrometry, which showed that the generally assumed value of 3 Be atoms per formula unit (apfu) is valid; only some samples such as the emerald from Kruta Balka deviate from this value (2.944 Be apfu). An important substitution in emerald (expressed as an exchange vector with the additive component Al2Be3Si6O18) is (Mg,Fe2+)NaAl1?1, leading to a hypothetical end-member NaAl(Mg,Fe2+)[Be3Si6O18] called femag-beryl with Na occupying a vacancy position (?) in the structural channels of beryl. Based on both our results and data from the literature, emeralds worldwide can be characterized based on the amount of femag-substitution. Other minor substitutions in Li-bearing emerald include the exchange vectors LiNa2Al1?2 and LiNaBe1?1, where the former is unique to the Kruta Balka emeralds. Rarely, some Li can also be situated at a channel site, based on stoichiometric considerations. Both Cr- and V-distribution can be very heterogeneous in individual crystals, as shown in the samples from Kruta Balka, Madagascar, and Zimbabwe. Nevertheless, taking average values available for emerald occurrences, the Cr/(Cr+V) ratio (Cr#) in combination with the Mg/(Mg+Fe) ratio (Mg#) and the amount of femag-substitution allows emerald occurrences to be characterized. The "ultramafic" schist-type emeralds with high Cr# and Mg# come from occur-rences where the Fe-Mg-Cr-V component is controlled by the presence of ultramafic meta-igneous rocks. Emeralds with highly variable Mg# come from "sedimentary" localities, where the Fe-Mg-Cr-V component is controlled by metamorphosed sediments such as black shales and carbonates. A "transitional" group has both metasediments and ultramafic rocks as country rocks. Most "ultramafic" schist type occurrences are characterized by a high amount of femag-component, whereas those from the "sedimentary" and "transitional" groups have low femag contents. Growth conditions derived from the zoning pattern combined replacement, sector, and oscillatory zoning in the Kruta Balka emeralds indicate disequilibrium growth from a fluid along with late-stage Na-infiltration. Inclusions in Kruta Balka emeralds (zircon with up to 11 wt% Hf, tourmaline, albite, Sc-bearing apatite) point to a pegmatitic origin.
DS2001-1029
2001
Schissel, D.Schissel, D., Samil, R.Deep mantle plumes and ore depositsGeological Society of America, Special Paper, Special Paper. 352, pp. 291-322.MantlePlumes, Metallogeny
DS2002-0378
2002
Schissel, D.Diakov, S., West, R., Schissel, D.Recent advances in the Norilsk model and its application for exploration of Ni Cu PGE sulphidesSociety of Economic Geologists Special Publication, No.9,pp.203-26.RussiaNickel, copper, platinum metallogeny, Deposit - Norilsk
DS200512-0940
2005
Schissel, D.J.Schissel, D.J.Diamonds in southern Africa.Geologicl Society of Nevada Program with abstracts, 2005, p. 81, 1/4p.Africa, South AfricaBrief overview
DS201112-0925
2011
Schivardi, R.Schivardi, R., Morelli, A.EP mantle: a 3 D transversely isotropic model of the upper mantle under the European plate.Geophysical Journal International, In press avaialbeEuropeGeophysics - seismics
DS200912-0681
2009
Schjeth, F.Secher, K., Heaman, L.M., Nielsen, T.F.D., Jensen, S.M., Schjeth, F., Creaser, R.A.Timing of kimberlite, carbonatite and ultramafic lamprophyric emplacement in the alkaline province located at 64 - 67 N in southern West Greenland.Lithos, In press available, 21p.Europe, GreenlandGeochronology
DS2002-0780
2002
Schjoth, F.Jensen, S.M., Hanson, H., Secher, K., Steenfelt, A., Schjoth, F., Rasmussen, T.M.Kimberlites and other ultramafic alkaline rocks in the Sismiut-Kangerfussuaq region, southwest Greenland.Geology of Greenland Survey Bulletin, No. 191, pp. 57-66.GreenlandDistribution and magnetic signatures of dykes
DS2003-0653
2003
Schjoth, F.Jensen, S.M., Lind, M., Rasmussen, T.M., Schjoth, F., Secher, K.Greenland exploration dat a on DVD - the guide to future kimberlite targets in theDanmarks og Gronlands Geologiske Undersagelse Rapport, 2003/21, 50p. plus 1 DVD $100.US www.geus.dkGreenlandMineral analyses, samples, drill logs
DS2003-0654
2003
Schjoth, F.Jensen, S.M., Lind, M., Rasmussen, T.M., Schjoth, F., Secher, K.Diamond exploration dat a from West GreenlandDanmarks OG Gronlands Geologiske Undersogelse, Rapport 2003-21, 50p.GreenlandBlank
DS200412-0912
2003
Schjoth, F.Jensen, S.M., Lind, M., Rasmussen, T.M., Schjoth, F., Secher, K.Greenland exploration dat a on DVD - the guide to future kimberlite targets in the compilation Diamond Exploration dat a from WestDanmarks OG Gronlands Geologiske Undersogelse, 2003/21, 50p. plus 1 DVD $100.US www.geus.dkEurope, GreenlandMaps, tables, data from assessment reports, GIS, Pdf Mineral analyses, samples, drill logs
DS200412-0913
2003
Schjoth, F.Jensen, S.M., Lind, M., Rasmussen, T.M., Schjoth, F., Secher, K.Diamond exploration dat a from West Greenland.Danmarks OG Gronlands Geologiske Undersogelse, Rapport 2003-21, 50p.Europe, GreenlandOverview of available company data, analyses
DS1995-1031
1995
Schkittenhardt, J.Kruger, F., Weber, M., Scherbaum, F., Schkittenhardt, J.Evidence for normal and in homogeneous lowermost mantle and core mantle boundary structure under Arctic /CanadaGeophysical Journal of International, Vol. 122, No. 2, August pp. 637-657.Arctic, Northwest TerritoriesMantle, Core
DS2002-1638
2002
SchlagerVan den Berg, E.H., Meetsers, Kenter, SchlagerAutomated separation of touching grains in digital images of thin sectionsComputers and Geosciences, Vol. 28, No. 2, Feb. pp. 179-90.GlobalComputers, Thin sections - not specific to diamonds
DS2003-0129
2003
Schlapfer, D.Bojinski, S., Schaepman, M., Schlapfer, D., Itten, K.SPECCHIO: a spectrum database for remote sensing applicationsComputers and Geosciences, Vol. 29, 1, pp. 27-38.GlobalComputer - program, Not specific to diamonds
DS1990-1311
1990
Schlauch, P.J.Schlauch, P.J.Opening and closing Mines in the 1990's how hard will it be?Brief overview slide headingsNorthwest Mining Association Preprint, 4pUnited StatesLegal, Mine closures
DS1995-1671
1995
SchleeSchlee, Karl, TorresanImaging the sea floorUnited States Geological Survey (USGS) Bulletin, No. 2079, 30pOceanRemote sensing, side scan sonar, sea beaM., Tectonics, crust
DS1950-0354
1957
Schlegel, D.M.Schlegel, D.M.Gemstones of the United StatesUnited States Geological Survey (USGS) Bulletin., No. 1042-G, PP. 203-253.United States, Great LakesDiamond Occurrences
DS1989-1355
1989
Schleicher, H.Schleicher, H., Keller, J., Kramm, U.U-Sr, neodymium and lead isotope studies on alkaline volcanicsandcarbonatites from the Kaiserstuhl Federal Republic of GermanyNew Mexico Bureau of Mines Bulletin., Continental Magmatism Abstract Volume, Held, Bulletin. No. 131, p. 235 Abstract held June 25-July 1GermanyCarbonatite
DS1990-1312
1990
Schleicher, H.Schleicher, H., Keller, J., Kramm, U.Isotope studies on alkaline volcanics and carbonatites from theKaiserstuhl, Federal Republic of GermanyLithos, Special Issue, Vol. 25, No. 4, pp. 21-36GermanyGeochronology, Carbonatite
DS1991-1515
1991
Schleicher, H.Schleicher, H., Baumann, A., Keller, J.lead isotopic systematics of alkaline volcanic rocks and carbonatites From the Kaiserstuhl, Upper Rhine rift valley, F.R.GChemical Geology, Vol. 93, No. 3/4, December 5, pp. 231-244GermanyCarbonatite, Geochronology
DS1995-1672
1995
Schleicher, H.Schleicher, H., et al.Very early enriched mantle reservoirs: evidence from lead neodymium Strontium studies on Indian carbonatites.Terra Nova, Abstract Vol., p. 333.IndiaCarbonatite
DS1998-1292
1998
Schleicher, H.Schleicher, H., Kramm, U., Viladkar, S.G.Enriched subcontinental Upper Mantle beneath southern India: evidence from lead neodymium Sr Co isotopic studies...Journal of Petrology, Vol. 39, No. 10, Oct. pp. 1765-86.IndiaCarbonatite, geochronology, Deposit - Tamil Nadu
DS201801-0056
2017
Schleicher, H.Schulzki, J., Viladkar, S.G., Schleicher, H.Carbonatite breccia: a neglected unit in Amba Dongar distreme, Gujarat, India.Carbonatite-alkaline rocks and associated mineral deposits , Dec. 8-11, abstract p. 38.Indiadeposit - Amba Dongar

Abstract: Carbonatite breccia forms a major unit in the carbonatite-alkalic diatreme of Amba Dongar. In addition to the innermost part of the ring structure, it also forms small and large plugs outside ring structure in form of discontinuous ring around sövite. It is mainly composed of rounded to sub-angular fragments of basement metamorphics, Bagh sandstones, pre-carbonatite basalt, nephelinite and sövite set in the carbonatitic matrix. Besides rock fragments it also shows presence xenocrystal minerals. Carbonatite breccia is later invaded by sövite, alvikite and ankeritic carbonatite. Thorite, pyrochlore, barite, apatite, fluorite and small amount of REE-minerals were introduced in carbonatite breccia by these later intrusives. Zircon, however seems have been caught up from metamorphic gneisses. Microprobe analyses of all these minerals are given here. In places, carbonatite breccia has been silicified by invading hydrothermal solutions rich in fluorite and silica.
DS201904-0777
2019
Schleicher, H.Schleicher, H.In situ determination of trace element and REE partitioning in a natural apatite carbonatite melt system using synchroton XRF microprobe analysis. Sevattur, Tamil NaduJournal of the Geological Society of India, Vol. 93, 3, pp. 305-312.Indiacarbonatite

Abstract: Inclusions of calcite within large euhedral apatite crystals from the pyroxenite-carbonatite-syenite complex of Sevattur, Tamil Nadu, south India, were identified to represent inclusions of a primary carbonatitic melt (calcite I) from which the apatites have crystallized. The apatites themselves are embedded into a younger batch of calcite-carbonatitic melt (calcite II). Using the synchrotron XRF microprobe at beamline L at HASYLAB/DESY (Hamburg), the concentrations of the trace elements Ba, Sr, Y, Zr, Th, La, Ce, Nd, Sm, Gd, Dy, and Er were determined both in melt inclusions as well as in host apatites and younger carbonatite matrix. Unexpected high REE concentrations were found not only in apatite but also in calcite, especially of the younger matrix phase, in agreement with the whole rock geochemistry. The data reveal an equilibrium distribution between melt inclusions and host apatite that allows the calculation of partition coefficients D = CiAp/CiCc=melt for elements of interest. Assuming 9% crystallization of the melt, which can be calculated from the whole rock analyses, the composition of the primary carbonatite melt prior to apatite crystallization can be determined. This composition is, with the exception of only few elements, nearly equal to that of the younger matrix carbonatite melt (calcite II), and thus gives evidence for the existence of different pulses of carbonatite melt during crystallization and consolidation of the carbonatite body. The results allow new insights into the processes of trace element and REE distribution between the two major igneous components of carbonatites and thus into the question of carbonatitic fractionation processes. The data reveal that mere apatite crystallization and fractionation does not lead to enriched REE compositions during carbonatite evolution but lowers their concentrations in the residual melts. But alternatively, if segregated apatite is collected and incorporated by a new melt batch, the overall REE of this melt will be increased.
DS201511-1824
2015
Schleicher, J.M.Bergantz, G.W., Schleicher, J.M., Burgisser, A.Open system dynamics and mixing in magma mushes.Nature Geoscience, Vol. 8, 10, pp. 793-796.MantleMagmatism

Abstract: Magma dominantly exists in a slowly cooling crystal-rich or mushy state1, 2, 3. Yet, observations of complexly zoned crystals4, some formed in just one to ten years5, 6, 7, 8, 9, as well as time-transgressive crystal fabrics10 imply that magmas mix and transition rapidly from a locked crystal mush to a mobile and eruptable fluid5, 6. Here we use a discrete-element numerical model that resolves crystal-scale granular interactions and fluid flow, to simulate the open-system dynamics of a magma mush. We find that when new magma is injected into a reservoir from below, the existing magma responds as a viscoplastic material: fault-like surfaces form around the edges of the new injection creating a central mixing bowl of magma that can be unlocked and become fluidized, allowing for complex mixing. We identify three distinct dynamic regimes that depend on the rate of magma injection. If the magma injection rate is slow, the intruded magma penetrates and spreads by porous media flow through the crystal mush. With increasing velocity, the intruded magma creates a stable cavity of fluidized magma that is isolated from the rest of the reservoir. At higher velocities still, the entire mixing bowl becomes fluidized. Circulation within the mixing bowl entrains crystals from the walls, bringing together crystals from different parts of the reservoir that may have experienced different physiochemical environments and leaving little melt unmixed. We conclude that both granular and fluid dynamics, when considered simultaneously, can explain observations of complex crystal fabrics and zoning observed in many magmatic systems.
DS1920-0468
1929
Schlenzig, D.J.Schlenzig, D.J.Die Gewinnung von DiamantenTech. Rundsch. Berl. Tagebl., Vol. 35, Jan. 16TH. No. 2, PP. 10-12.GlobalMining Engineering
DS1860-0345
1880
Schlesinger, M.Schlesinger, M., Fonentay, E.Compagnie Francaise des Mines des Diamants du CapParis:, 8P.Africa, South AfricaDiamond Mining
DS1992-1341
1992
Schlidowski, M.Schlidowski, M., Golubic, S., Kimberley, M.M., McKirdy, D.M.Early organic evolutionSpringer-Verlag, 640p. approx. $ 300.00 United StatesGlobalBook -ad, Organic evolution
DS1999-0630
1999
Schlindwein, V.Schlindwein, V.Aeromagnetic study of the continental crust of northeast GreenlandJournal of Geophysical Research, Vol. 104, No. 4, Apr. 10, pp. 7527-38.GreenlandGeophysics - aeromagnetics
DS1999-0631
1999
Schlindwein, V.Schlindwein, V., Jokat, W.Structure and evolution of the continental crust of northern Greenland and integrated geophysical studies.Journal of Geophysical Research, Vol. 104, No. 7, July 10, pp. 15227-46.GreenlandTectonics, Geophysics - seismics
DS200612-1236
2006
Schlindwein, V.Schlindwein, V.On the use of teleseismic receiver functions for studying the crustal structure of Iceland.Geophysical Journal International, Vol. 164, 3, pp; 551-568.Europe, IcelandGeophysics - seismics
DS1989-1265
1989
Schlische, R.W.Reynolds, D.J., Schlische, R.W.Comparative studies of continental rift systemsGeological Society of America Abstract Volume, Vol. 21, No. 2, p. 61. (Abstract only)Appalachia, TanzaniaNewark Group eastern N.America and Lakes Tanganyika and, Tectonics
DS1991-1516
1991
Schlische, R.W.Schlische, R.W.Half graben basin filling models: new constraints on continental extensional basin developmentBasin Research, Vol. 3, No. 3, Sept. pp. 123-142GlobalBasin, Model - half graben
DS1993-1392
1993
Schlische, R.W.Schlische, R.W.Anatomy and evolution of the Triassic-Jurassic continental rift system, eastern North AmericaTectonics, Vol. 12, No. 4, August pp. 1026-1042GlobalTectonics, Appalachia, Rifting, graben, stratigraphy
DS1994-0046
1994
Schlische, R.W.Anders, M.H., Schlische, R.W.Overlapping faults, intrabasin highs and the growth of normal faultsJournal of Geology, Vol. 102, No. 2, March pp. 165-180Basin and RangeStructure, Fault systems
DS2003-1223
2003
Schlische, R.W.Schlische, R.W., Withjack, M.O., Olsen, P.E.Relative timing of CAMP rifting continental breakup and basin inversion: tectonicAmerican Geophysical Union, Geophysical Monograph, No. 136, pp. 33-60.MantleBlank
DS200412-1752
2003
Schlische, R.W.Schlische, R.W., Withjack, M.O., Olsen, P.E.Relative timing of CAMP rifting continental breakup and basin inversion: tectonic significance.American Geophysical Union, Geophysical Monograph, No. 136, pp. 33-60.MantleTectonics
DS2002-0380
2002
SchlitzerDiepenbroek, M., Grobe, H., Reinke, M., Schindler, U., SchlitzerPANGEA - an information system for environmental sciencesComputers and Geosciences, Vol. 28, 10, pp.1201-10.GlobalComputers - programs
DS2002-1418
2002
Schlitzer, R.Schlitzer, R.Interactive analysis and visualization of geoscience dat a with Ocean Dat a ViewComputers and Geosciences, Vol. 28, 10, pp.1211-18.GlobalComputers - programs
DS1930-0098
1932
Schlossmacher, K.Bauer, M., Schlossmacher, K.Diamanten in Czecho Slovakia BohemiaEdelsteinkunde., PP. 465-466.Bohemia, Czechoslovakia, Europe, Russia, Siberia, Lapland, UralsBlank
DS1930-0099
1932
Schlossmacher, K.Bauer, M., Schlossmacher, K.Diamenten in ChinaEdelsteinkunde, [gemology, P. 466.China, ShandongDiamond Occurrences
DS1960-1209
1969
Schlossmacher, K.Schlossmacher, K.Edelsteine und Perlen. #1Stuttgart: Schweizerbart, 5th. Edition., 387P.GlobalKimberlite, Kimberley, Janlib, Gemology
DS1930-0100
1932
Schlossmacher.Bauer, M., Schlossmacher.EdelsteinkundeZetz. Deuts. Geol. Ges., 580P.South Africa, NamaqualandLittoral Diamond Placers, History, Archeology Littoral Diamond
DS200612-1237
2006
Schluter, T.Schluter, T.Geological Atlas of Africa.Springer, 272p. $ 169.00AfricaMap
DS200812-1017
2008
Schluter, T.Schluter, T.Geological atlas of Africa. with notes on stratigraphy, tectonics, economic geology, geohazards, geosites.Springer, 2nd ed. 308p. 442 illusAfricaAtlas
DS2001-1239
2001
Schmadicke, E.Will, T.M., Schmadicke, E.A first find of retrogressed eclogites in the Odenwald crystalline complex, mid German crystalline rise: ...Lithos, Vol. 59, No. 3, Nov. pp. 109=25.Germany, Central VariscidesEclogites
DS200612-1238
2006
Schmadicke, E.Schmadicke, E., Will, T.M.First evidence of eclogite facies metamorphism in the Shackleton Range, Antarctica: trace of suture between East and West Gondwana?Geology, Vol. 34, 3, March pp. 133-136.AntarcticaMetamorphism
DS201112-0926
2011
Schmadicke, E.Schmadicke, E., Okrusch, M., Rupprecht-Gutowski, P., Will, T.M.Garnet pyroxenite, eclogite and alkremite xenoliths from the off-craton Gibeon kimberlite field, Namibia: a window into the upper mantle of the Rehoboth Terrane.Precambrian Research, In press available, 63p.Africa, NamibiaGibeon kimberlite
DS201112-0927
2011
Schmadicke, E.Schmadicke, E., Okrusch, M., Rupprecht-Gutpwski, P., Will, T.M.Garnet pyroxenite, eclogite and alkremite xenoliths from the off-craton Gibeon kimberlite field, Namibia: a window into the upper mantle of Rehoboth Terrane.Precambrian Research, Vol. 191, 1-2, pp. 1-17.Africa, NamibiaEclogite, geothermometry - Gibeon
DS201511-1878
2015
Schmadicke, E.Schmadicke, E., Gose, J., Reinhardt, J., Will, T.M., Stalder, R.Garnet in cratonic and non-cratonic mantle and lower crustal xenoliths from southern Africa: composition, water in corporation and geodynamic constraints.Precambrian Research, Vol. 270, pp. 285-299.Africa, South Africa, Lesotho, NamibiaKaapvaal craton, Rehoboth Terrane

Abstract: Garnets from kimberlite-hosted mantle and a few xenoliths from the lower crust were investigated for water, major, minor, and trace elements. Xenoliths from the mantle comprise pyroxenite, eclogite, alkremite, and peridotite, and crustal xenoliths are mafic high-pressure granulites. Samples from South Africa, Lesotho, and Namibia comprise two principal settings, Kaapvaal Craton (‘on craton’) and Rehoboth terrane (‘off craton’). The composition of garnet depends on rock type but is unrelated to the setting, except for Ti and Cr. In garnets from ‘off craton’ mantle xenoliths, Ti positively correlates with Cr whereas those from ‘on craton’ samples reveal a negative correlation between both elements. Rare earth element patterns indicative of a metasomatic overprint are observed in garnets from both settings, especially in eclogitic garnet. Water contents in garnet are low and range from <1 to about 40 ppm. No setting-related difference occurs, but a weak correlation between water and rock type exists. Water contents in garnets from eclogite and mafic granulite are lower than those in pyroxenite, alkremite, and peridotite. All garnets are water under-saturated, i.e. they do not contain the maximum amount of water that can be accommodated in the mineral structure. Cratonic and non-cratonic samples also show the same characteristics in the infrared (IR) absorption spectra. An absorption band at 3650 cm-1 is typical for most mantle garnets. Bands at 3520 and 3570 cm-1 are present only in TiO2-rich garnets from the Rehoboth terrane and are ascribed to a Ti-related hydrogen substitution. A number of garnets, especially from the Kaapvaal Craton, contain molecular water in addition to structural water. Molecular water is inhomogeneously distributed at grain scale pointing to local interaction with fluid and to disequilibrium at grain scale. These garnets consistently reveal either submicroscopic hydrous phases or additional IR bands at 3630 and 3610-3600 cm-1 caused by structural water. Both features do not occur in garnets in which molecular water is absent. The observations imply (i) relatively late introduction of fluid, at least in cases where hydrous phases formed, and (ii) a relatively dry environment because only water-deficient garnets are able to incorporate additional structural water. Most importantly, they imply (iii) that the low water contents are primary and not due to water loss during upward transport. This late water influx is not responsible for the metasomatic overprint indicated by garnet REE patterns. The results of this study suggest dry conditions in the lithosphere, including mantle and crustal sections of both the Kaapvaal Craton (‘on craton’) and the Rehoboth terrane (‘off craton’). If the low water contents contributed to the stabilization of the Kaapvaal cratonic root (Peslier et al., 2010) the same should apply to the Rehoboth lithosphere where the same variety of rock types occurs. The extremely low water contents in eclogite relative to pyroxenite may be explained by an oceanic crust origin of the eclogites. Subduction and partial melting would cause depletion of water and incompatible elements. The pyroxenites formed by crystal accumulation in the mantle and did not suffer melt depletion. Such a difference in origin can be reconciled with the low Ti contents in eclogitic garnet and the high Ti contents in pyroxenitic garnet.
DS201511-1879
2015
Schmadicke, E.Schmadicke, E., Will, T.M., Mezger, K.Garnet pyroxenite from the Shackleton Range, Antarctica: intrusion of plume-derived picritic melts in the continental lithosphere during Rodinia breakup.Lithos, Vol. 238, pp. 185-206.AntarcticaPicrite

Abstract: Lenses of ultramafic rocks occur in supracrustal high-grade gneiss in the northern Haskard Highlands, Shackleton Range, East Antarctica. Olivine-bearing garnet pyroxenite is the dominant rock type that is associated with hornblendite and subordinate spinel peridotite and amphibolite. The high-pressure (23-25 kbar) garnet-olivine assemblage of the pyroxenite formed during Pan-African eclogite-facies metamorphism. Associated collisional tectonics led to the incorporation of the ultramafic and mafic rocks in upper crustal rocks of a subducting continental margin. The ultramafic-mafic rocks are tracers of a palaeo-suture zone and are critical for reconstructing Gondwana amalgamation. Thus, it is important to infer the tectonic setting of the rocks prior to emplacement into their current position, i.e. were the rocks part of the oceanic crust, the sub-oceanic, or the sub-continental mantle? Major and trace elements together with Pb and Nd isotope data imply that the precursor rocks of the pyroxenites and hornblendites (the latter being retrogressed pyroxenite equivalents) formed as plume-related melts, with many characteristics typical for ocean-island tholeiitic magmas. Hence, pyroxenite and hornblendite are interpreted as metamorphic equivalents of picritic melts. They differ from most garnet pyroxenites worldwide in composition and genesis. The latter formed as high-pressure clinopyroxene-rich cumulates from basaltic melts. The volumetrically minor amphibolites, sharing many geochemical characteristics with pyroxenites and hornblendites, are also interpreted as metamorphic equivalents of plume-related melts. It is inferred that the picritic melts crystallized at medium- to high-pressure conditions in the upper continental mantle or in the transition zone between mantle and continental crust. The subordinate spinel peridotites are interpreted as fragments of the uppermost, depleted mantle. They are probably the wall rocks into which the picritic melts intruded. The Pb and Nd mantle separation ages of the picritic melts range from 770 to 870 Ma. These model ages are very similar to the emplacement ages of numerous global mafic and ultramafic dykes, which are genetically linked to mantle plume activity that initiated Rodinia rifting and breakup. The protoliths of pyroxenite and related rocks in the Shackleton Range most likely formed during the initial stages of plume magmatism that eventually led to Rodinia breakup.
DS201601-0043
2015
Schmadicke, E.Schmadicke, E., Will, T.M., Mezger, K.Garnet pyroxenite from the Shackleton Range, Antartica: intrusion of plume derived picritic melts in the continental lithosphere during Rodinia breakup.Lithos, Vol. 238, pp. 185-206.AntarcticaPicrite

Abstract: Lenses of ultramafic rocks occur in supracrustal high-grade gneiss in the northern Haskard Highlands, Shackleton Range, East Antarctica. Olivine-bearing garnet pyroxenite is the dominant rock type that is associated with hornblendite and subordinate spinel peridotite and amphibolite. The high-pressure (23-25 kbar) garnet-olivine assemblage of the pyroxenite formed during Pan-African eclogite-facies metamorphism. Associated collisional tectonics led to the incorporation of the ultramafic and mafic rocks in upper crustal rocks of a subducting continental margin. The ultramafic-mafic rocks are tracers of a paleo-suture zone and are critical for reconstructing Gondwana amalgamation. Thus, it is important to infer the tectonic setting of the rocks prior to emplacement into their current position, i.e., were the rocks part of the oceanic crust, the sub-oceanic, or the sub-continental mantle? Major and trace elements together with Pb and Nd isotope data imply that the precursor rocks of the pyroxenites and hornblendites (the latter being retrogressed pyroxenite equivalents) formed as plume-related melts, with many characteristics typical for ocean-island tholeiitic magmas. Hence, pyroxenite and hornblendite are interpreted as metamorphic equivalents of picritic melts. They differ from most garnet pyroxenites worldwide in composition and genesis. The latter formed as high-pressure clinopyroxene-rich cumulates from basaltic melts. The volumetrically minor amphibolites, sharing many geochemical characteristics with pyroxenites and hornblendites, are also interpreted as metamorphic equivalents of plume-related melts. It is inferred that the picritic melts crystallized at medium- to high-pressure conditions in the upper continental mantle or in the transition zone between mantle and continental crust. The subordinate spinel peridotites are interpreted as fragments of the uppermost, depleted mantle. They are probably the wall rocks into which the picritic melts intruded. The Pb and Nd mantle separation ages of the picritic melts range from 770 to 870 Ma. These model ages are very similar to the emplacement ages of numerous global mafic and ultramafic dykes, which are genetically linked to mantle plume activity that initiated Rodinia rifting and breakup. The protoliths of pyroxenite and related rocks in the Shackleton Range most likely formed during the initial stages of plume magmatism that eventually led to the Rodinia breakup.
DS201807-1494
2018
Schmadicke, E.Gose, J., Schmadicke, E.Water in corporation in garnet: coesite versus quartz ecologite from Erzgebirge and Fichtelbirge.Journal of Petrology, Vol. 59, 2, pp. 207-232.Europe, Germanycoesite
DS201911-2558
2019
Schmadicke, E.Schmadicke, E., Gose, J.Low water contents in garnet of orogenic peridotite: clues for an abyssal or mantle-wedge origin?European Journal of Mineralogy, Vol. 31, pp. 715-730.Europe, Germanywater

Abstract: Data on water in nominally anhydrous minerals (NAMs) of orogenic garnet-bearing ultramafic rocks (GBU) are extremely rare. In this study, garnet of peridotite and pyroxenite from Erzgebirge (EG), Germany, and two peridotite samples from Alpe Arami (AA), Switzerland, were analyzed by infrared (IR) spectroscopy. Garnet from EG peridotite and pyroxenite yielded IR absorption bands at 3650 ± 10 cm?1 (type I) and in the wavenumber range of 3570-3630 cm?1 (type II) that are ascribed to structural hydroxyl (colloquially “water”). Additional broad band’s centered at <3460 cm?1, present in about half of the samples, are related to molecular water (MW). The content of structural H2O defined by band types I + II is low (3-68 ppm) in all EG samples. Structural water is negatively correlated to Mg and Ti and positively to Y and HREE in EG garnet. Including molecular water, a pronounced positive correlation between H2O and Li is observed. Because the intensity of the type II band is enhanced in domains with molecular water, the primary, peak metamorphic H2O content in EG garnet was probably as low as 0-11 ppm. Equally low contents of structural water are present in AA garnet (10-13 ppm) in which molecular water is negligible. Such concentrations are distinctly lower than the water storage capacity of garnet at the relevant pressure. Water loss upon decompression cannot serve as an explanation for the low contents because, on the contrary, post-peak-metamorphic influx of H2O led garnet to take up secondary structural water. Hence, the results are interpreted as an indication of severe water deficiency at peak metamorphism. Notably, the obtained data agree with the H2O content of 6 ppm reported in garnet from Cima di Gagnone peridotite, which originated as abyssal peridotite. It remains unknown if these low contents are typical for an abyssal, low-pressure protolith but, if the rocks were part of the lowermost, most hydrated portion of the mantle wedge, they are expected to contain much more water. Given that garnet in basaltic coesite eclogite from the Erzgebirge is equally water-deficient as the GBU samples from the same unit, it is at least a possibility that both rock types share a low-pressure origin in an oceanic setting.
DS1989-1167
1989
Schmahl, W.W.Palmer, D.C., Salje, E.K.H., Schmahl, W.W.Phase transitions in leucite: X-ray diffraction studiesPhysics and Chemistry of Minerals, Vol. 16, No. 7, pp. 714-719GlobalLeucite, Mineralogy
DS200512-0941
2005
Schmalholz, S.M.Schmalholz, S.M., Podladchikov, Y.Y., Jamtveit, B.Structural softening of the lithosphere.Terra Nova, Vol. 17, 1, pp. 66-72.MantleTectonics
DS201212-0174
2012
Schmalholz, S.M.Duretz, T., Schmalholz, S.M., Gerya, T.V.Dynamics of slab detachment.Geochemical, Geophysics, Geosystems: G3, Vol. 13, 3, 17p.MantleBreakoff, heating
DS201606-1108
2016
Schmalholz, S.M.Reuber, G., Kaus, B.J.P., Schmalholz, S.M., White, R.W.Nonlithostatic pressure during subduction and collision and the formation of (ultra) high pressure rocks.Geology, Vol. 44, 5, pp. 343-346.UHP - subduction

Abstract: The mechanisms that result in the formation of high-pressure (HP) and ultrahigh-pressure (UHP) rocks are controversial. The usual interpretation assumes that pressure is close to lithostatic, petrological pressure estimates can be transferred to depth, and (U)HP rocks have been exhumed from great depth. An alternative explanation is that pressure can be larger than lithostatic, particularly in continental collision zones, and (U)HP rocks could thus have formed at shallower depths. To better understand the mechanical feasibility of these hypotheses, we performed thermomechanical numerical simulations of a typical subduction and collision scenario. If the subducting crust is laterally homogeneous and has small effective friction angles (and is thus weak), we reproduce earlier findings that <20% deviation of lithostatic pressure occurs within a subduction channel. However, many orogenies involve rocks that are dry and strong, and the crust is mechanically heterogeneous. If these factors are taken into account, simulations show that pressures can be significantly larger than lithostatic within nappe-size, mechanically strong crustal units, or within a strong lower crust, as a result of tectonic deformation. Systematic simulations show that these effects are most pronounced at the base of the crust (at ?40 km), where pressures can reach 2-3 GPa (therefore within the coesite stability field) for millions of years. These pressures are often released rapidly during ongoing deformation. Relating metamorphic pressure estimates to depth might thus be problematic in mechanically heterogeneous crustal rock units that appear to have been exhumed in an ultrafast manner.
DS200712-0195
2006
Schmalzi, J.Coltice, N., Schmalzi, J.Mixing times in the mantle of the early Earth derived from 2-D and 3-D numerical simulations of convection.Geophysical Research Letters, Vol. 33, 23, Dec. 16, L23305.MantleConvection
DS200412-1920
2004
Schmalzl, J.Stein, C., Schmalzl, J., Hansen, U.The effect of rheological parameters on plate behaviour in a self consistent model of mantle convection.Physics of the Earth and Planetary Interiors, Vol. 142, 3-4, pp. 225-255.MantleSubduction
DS200612-0596
2005
Schmalzl, J.Hoink, T., Schmalzl, J., Hansen, U.Formation of compositional structures by sedimentation in vigorous convection.Physics of the Earth and Planetary Interiors, Vol. 153, 1-3, pp. 11-20.MantleConvection, tectonics
DS201012-0671
2010
Schmandt, B.Schmandt, B., Humphreys, E.Complex subduction and small scale convection revealed by body wave tomography of the western United States upper mantle.Earth and Planetary Science Letters, Vol. 297, 3-4, pp. 435-445.United StatesTomography
DS201012-0672
2010
Schmandt, B.Schmandt, B., Humphreys, E.Complex subduction and small scale convection revealed by body wave tomography of the western United States upper mantle.Earth and Planetary Science Letters, Vol. 297, 3-4, pp. 435-445.United StatesTomography
DS201112-0223
2011
Schmandt, B.Crow, R., Karlstrom, K., Asmerom, Y., Schmandt, B., Polyak, V., DuFrane, S.A.Shrinking of the Colorado Plateau via lithospheric mantle erosion: evidence from Nd and Sr isotopes and geochronology of Neogene basalts.Geology, Vol. 39, 1, pp. 27-30.United States, Colorado PlateauGeochronology
DS201412-0249
2014
Schmandt, B.Foster, K., Dueker, K., Schmandt, B., Yuan, H.A sharp cratonic lithosphere-asthenosphere boundary beneath the American Midwest and its relation to mantle flow.Earth and Planetary Science Letters, Vol. 402, pp. 82-89.United States, Colorado PlateauGeophysics - seismics
DS201412-0779
2014
Schmandt, B.Schmandt, B., Jacobsen, S.D., Becker, T.W., Liu, Z., Dueker, K.G.Dehydration melting at the top of the lower mantle.Science, Vol. 344, 6189, June 13, pp. 1265-68.MantleWater in transition zone
DS201601-0009
2015
Schmandt, B.Cafferky, S., Schmandt, B.Teleseismic P wave spectra from USArray and implications for upper mantle attentuation and scattering.Geochemistry, Geophysics, Geosystems: G3, Vol. 16, 10, pp. 3343-3361.United StatesGeophysics - seismics

Abstract: Teleseismic P wave amplitude spectra from deep earthquakes recorded by USArray are inverted for maps of upper mantle ?t* for multiple frequency bands within 0.08-2 Hz. All frequency bands show high ?t* regions in the southwestern U.S., southern Rocky Mountains, and Appalachian margin. Low ?t* is more common across the cratonic interior. Inversions with narrower frequency bands yield similar patterns, but greater ?t* magnitudes. Even the two standard deviation ?t* magnitude for the widest band is ?2-7 times greater than predicted by global QS tomography or an anelastic olivine thermal model, suggesting that much of the ?t* signal is nonthermal in origin. Nonthermal contributions are further indicated by only a moderate correlation between ?t* and P travel times. Some geographic variations, such as high ?t* in parts of the cratonic interior with high mantle velocities and low heat flow, demonstrate that the influence of temperature is regionally overwhelmed. Transverse spectra are used to investigate the importance of scattering because they would receive no P energy in the absence of 3-D heterogeneity or anisotropy. Transverse to vertical (T/Z) spectral ratios for stations with high ?t* are higher and exhibit steeper increases with frequency compared to T/Z spectra for low ?t* stations. The large magnitude of ?t* estimates and the T/Z spectra are consistent with major contributions to ?t* from scattering. A weak positive correlation between intrinsic attenuation and apparent attenuation due to scattering may contribute to ?t* magnitude and the moderate correlation of ?t* with travel times.
DS202202-0229
2022
Schmandte, B.Zhou, W-Y., Zhang, J.S., Huang, Q., Lai, X., Chen, B., Dera, P., Schmandte, B.High pressure-temperature single crystal elasticity of ringwoodite: implications for detecting the 520 discontinuity and metastable ringwoodite at depths greater than 660 km.Earth and planetary Science Letters, Vol. 579, 117359, 11p. PdfMantleringwoodite

Abstract: The 520 km discontinuity (the 520) and the 660 km discontinuity (the 660) are primarily caused by the wadsleyite to ringwoodite and ringwoodite to bridgmanite + ferropericlase phase transitions, respectively. Global seismic studies show significant regional variations of the 520, which are likely due to chemical and thermal heterogeneities in the Mantle Transition Zone (MTZ). However, the effects of chemical composition and temperature on the detectability of the 520 are unclear. Additionally, it remains unknown whether the possibly existing metastable ringwoodite in the core of the cold and fast subducting slabs could create a detectable seismic signature near the top of the lower mantle. Our understanding of both issues is hindered by the lack of single-crystal elasticity measurements of ringwoodite at simultaneous high pressure-temperature (P-T) conditions. In this study, we measured the single-crystal elasticity of an anhydrous Fe-bearing ringwoodite up to 32 GPa and 700 K by Brillouin spectroscopy, and then modeled the composition-dependent elastic properties of ringwoodite to calculate the compositional effects on the velocity jumps at the 520. We found that opposite to the effect of Fe, water enhances the Vp (P-wave velocity) jump, yet decreases the Vs (S-wave velocity) jump of the 520 across the wadsleyite to ringwoodite transition. Higher temperature increases both Vp and Vs contrasts across the 520. At depths between 660-700 km in the lower mantle, the existence of metastable ringwoodite may only result in ?1-2% low velocity anomaly, which is seismically difficult to resolve. The low velocity anomaly caused by metastable ringwoodite increases to 5-7% at 750 km depth due to the weak pressure dependence of Vs in ringwoodite at lower mantle conditions, but whether it is seismically detectable depends on the extension of the regions in subducted slabs that are sufficiently cold to host metastable ringwoodite.
DS1900-0700
1908
Schmeisser, C.Schmeisser, C.Die Nutzbaren Bodenschatze der Deutschen SchutzgebieteDeut. Kolon. Zeitung, PP. 83-125. ALSO: ZEITSCHR. F. PRAKT. GEOL., PP. 28-33; PP. 1Africa, NamibiaMineral Resources, Diamond Occurrences
DS1995-0373
1995
Schmeling, H.Cruden, A.R., Koyi, H., Schmeling, H.Diapiric basal entrainment of mafic into felsic magmaEarth and Planetary Science Letters, Vol. 131, No. 3-4, April pp. 321-340GlobalMagma
DS1996-1259
1996
Schmeling, H.Schmeling, H., Bussod, G.Y.Variable viscosity convection and partial melting in the continentalasthenosphere.Journal of Geophysical Research, Vol. 101, No. 3, March 10, pp. 5411-MantleGeophysics -seismics, Melting
DS1998-1299
1998
Schmeling, H.Schott, B., Schmeling, H.Delamination and detachment of a lithospheric rootTectonophysics, Vol. 296, No. 3-4, Nov. 10, pp. 225-248.MantleSubduction
DS1999-0632
1999
Schmeling, H.Schmeling, H., Monz, R., Rubie, D.C.The influence of olivine metastability on the dynamics of subductionEarth and Planetary Science Letters, Vol.165, No.1, Jan.15, pp.55-66.MantleGeodynamics, Subduction
DS1999-0635
1999
Schmeling, H.Schott, B., Yuen, D.A., Schmeling, H.Viscous heating in heterogeneous media as applied to the thermal interaction between crust and mantle.Geophysical Research. Lett., Vol. 26, No. 4, Feb. 15, pp. 513-16.MantleGeothermometry
DS2000-0871
2000
Schmeling, H.Schott, B., Yuen, D.A., Schmeling, H.The diversity of tectonics from fluid dynamical modeling of the lithosphere mantle systemTectonophysics, Vol.322, No.1-2, July10, pp.35-52.MantleTectonics, Geodynamics - model
DS2000-0951
2000
Schmeling, H.Tetzlaff, M., Schmeling, H.The influence of olivine metastability on deep subduction of oceanic lithosphere.Physical Earth and Planetary Interiors, Vol. 120, No.1-2, pp. 29-38.GlobalPetrology - experimental, Subduction, tectonics
DS2001-1128
2001
Schmeling, H.Steinberger, B., Schmeling, H., Marquart, G.Large scale lithospheric stress field and topography induced by global mantle circulation.Earth and Planetary Science Letters, Vol. 186, No. 1, Mar. 15, pp. 75-92.MantleGeophysics, Tectonics, geodynamics
DS2003-1224
2003
Schmeling, H.Schmeling, H., Marquart, G., Ruedas, T.Pressure and temperature dependent thermal expansivity and the effect on mantleGeophysical Journal International, No. 154, 1, pp. 224-9.MantleBlank
DS200412-1229
2004
Schmeling, H.Marquart, G., Schmeling, H.A dynamic model for the Iceland plume and the north Atlantic based on tomography and gravity data.Geophysical Journal International, Vol. 159, 1, pp. 40-52.Europe, IcelandGeodynamics, tectonics, geophysics - gravity
DS200412-1753
2003
Schmeling, H.Schmeling, H., Marquart, G., Ruedas, T.Pressure and temperature dependent thermal expansivity and the effect on mantle convection and surface observables.Geophysical Journal International, No. 154, 1, pp. 224-9.MantleGeothermometry
DS200812-0745
2008
Schmeling, H.Mihalffy, P., Steinberger, B., Schmeling, H.The effect of the large scale mantle flow field on the Iceland hotspot track.Tectonophysics, Vol. 447, 1-4, pp. 5-18.Europe, IcelandHotspots, plumes
DS200812-1018
2008
Schmeling, H.Schmeling, H., Marquart, G.Crustal accretion and dynamic feedback on mantle melting of a ridge centred plume: the Iceland case.Tectonophysics, Vol. 447, 1-4, pp. 31-52.Europe, IcelandMelting
DS200912-0673
2009
Schmeling, H.Schmeling, H.Dynamic models of continental rifting with melt generation.Tectonophysics, In press available ( non-format 39p.)AfricaEast African Rift Zone
DS201212-0634
2012
Schmeling, H.Shahraki, M., Schmeling, H.Plume induced geoid anomalies from 2D axi-symmetric temperature and pressure dependent mantle convection models.Journal of Geodynamics, Vol. 59-60, pp. 193-206.MantleConvection
DS1992-1646
1992
Schmelling, H.Weinberg, R.F., Schmelling, H.Polydiapirs: multiwavelength gravity structuresJournal of Structural Geology, Vol. 14, No. 4, pp. 425-436GlobalStructure, Dome in domes
DS200612-1239
2006
Schmelling, H.Schmelling, H.A model of episodic melt extraction for plumes.Journal of Geophysical Research, Vol. 111, B3, B03202 March 23,MantleMelting
DS200812-0419
2008
Schmelling, H.Golabek, G.J., Schmelling, H., Tackley, P.J.Earth's core formation aided by flow channelling instabilities induced by iron diapirs.Earth and Planetary Science Letters, Vol. 271, 1-4, pp. 24-33.MantleCore, iron
DS201012-0673
2010
Schmelling, H.Schmelling, H.Dynamic models of continental rifting with melt generation.Tectonophysics, Vol. 480, 1-4, pp. 33-47.MantleGeodynamics
DS200712-0950
2007
Schmerr, N.Schmerr, N., Garnero, E.J.Upper mantle discontinuity topography from thermal and chemical heterogeneity.Science, Vol. 318, 5850, Nov. 24, pp. 623-625.MantleGeothermometry
DS1981-0368
1981
Schmetzer, K.Schmetzer, K., Bank, H.Garnets from Umba Valley, Tanzania- Members of the Solid Solution Series Pyrope-spessartine.Neues Jahrbuch f?r Mineralogie MONATS., No. 8, PP. 349-354.Tanzania, East AfricaBlank
DS1990-1347
1990
Schmetzer, K.Shigley, J.E., Dirlam, D.M., Schmetzer, K., Jobbins, E.A.Gem localities of the 1980's. Diamonds featured pp. 12-14Gems and Gemology, Vol. 26, Spring pp. 4-31GlobalGemstones, Diamond - brief overview
DS2002-1419
2002
Schmetzer, K.Schmetzer, K., Hainschwang, T., Bernhardt, H.-J., Kiefert, L.New chromium and vanadium bearing garnets from Tranoro, MadagascarGems & Gemology, Vol. 38, Summer, pp. 148-55.MadagascarGarnet - mineralogy ( not specific to diamonds)
DS201112-0928
2010
Schmetzer, K.Schmetzer, K.High pressure high temperature treatment of diamonds - a review of the patent literature from five decades 1960-2009.Journal of Gemmology, Vol. 32, 1-4, pp. 52-65. plus supplementGlobalUHP - Color treatment
DS201704-0646
2017
Schmetzer, K.Schmetzer, K., Gilg, H.A., Vaupel, E.Synthetic emeralds grown by Richard Nacken in the mid-1920's: properties, growth technique, and historical account.Gems & Gemology, Vol. 52, 4, pp. 368-392.Europe, GermanySynthetic - emeralds

Abstract: Chemical and microscopic examination of the first gem-quality synthetic emeralds of facetable size proves that Prof. Richard Nacken grew two main types of emerald by flux methods in the mid-1920s. One of these two types, grown with colorless beryl seeds in molybdenum-bearing and vanadium-free fluxes, has not previously been mentioned in the literature and would appear to be unknown to gemologists. The other main type, which has already been described in gemological publications, was grown from molybdenum- and vanadium-bearing fluxes. In drawing these conclusions, rough and faceted synthetic emeralds produced by Nacken were available for study from two principal sources: the Deutsches Museum in Munich, to which Nacken had donated samples in 1961, and family members who had inherited such crystals. Chemical, morphological, and microscopic properties are given, and circumstances concerning the developmental history of the Nacken production, including the possibility of collaboration with IG Farben (a subject of past speculation), are discussed as well. The latter has recently been elucidated by the discovery of original documents from the IG Farben gemstone plant, preserved in the Archives of the German Federal State of Saxony-Anhalt.
DS202012-2249
2020
Schmetzer, K.Schmetzer, K., Martayan, G., Blake, A.R.History of the Chivor emerald mine, part 2 ( 1924-1970): between insolvency and viability.Gems & Gemology, Vol. 56, 2, summer pp. 230-257. pdfSouth America, Columbiadeposit - Chivor

Abstract: The history of the Chivor emerald mine in Colombia is a saga with countless twists and turns, involving parties from across the globe. Indigenous people initially exploited the property, followed by the Spanish in the sixteenth and seventeenth centuries, before abandonment set in for 200 years. The mine was rediscovered by Francisco Restrepo in the 1880s, and ownership over the ensuing decades passed through several Colombian owners and eventually to an American company, the Colombian Emerald Syndicate, Ltd., with an intervening but unsuccessful attempt by a German group organized by Fritz Klein to take control. With the Colombian Emerald Syndicate succumbing to bankruptcy in 1923, the property was sold and then transferred in 1924 to another American firm, the Colombia Emerald Development Corporation. Under the new ownership, stock market speculation played a far more prominent role in the story than actual mining. Nonetheless, periods of more productive mining operations did take place under managers Peter W. Rainier and Russell W. Anderton. Yet these were not enough to prevent the company, renamed Chivor Emerald Mines, Inc. in 1933, from entering insolvency in 1952 and being placed into receivership. Leadership by Willis Frederick Bronkie enabled the firm to regain independence in 1970 and shortly thereafter to be sold in a series of transactions, with Chivor gradually being returned to Colombian interests.
DS202102-0219
2020
Schmetzer, K.Schmetzer, K., Martayan, G., Ortiz, J.G.History of the Chivor emerald mine, Part 1 ( 1880-1925): from rediscovery to early production. Part 2 listed previouslyGems & Gemology , Vol. 56, 1, pp. 66-109.South America, Colombiaemerald

Abstract: The history of the Chivor emerald mine in Colombia is rife with legend and adventure. The tale traces from early exploitation by indigenous people, to work by the Spanish in the sixteenth and seventeenth centuries, to 200 years of abandonment and jungle overgrowth. The story then picks up with rediscovery near the turn of the twentieth century by the Colombian mining engineer Francisco Restrepo using clues from a historical manuscript. Still the saga continued, with repeated shortages of investment funds driving multiple ownership changes and little progress toward mining the largely inaccessible deposit. The German gem merchant Fritz Klein, in cooperation with Restrepo, pursued limited mining activities with a small number of workers for a few months prior to the outbreak of World War I. After the war, the American company Colombian Emerald Syndicate, Ltd., took ownership, and mining operations resumed under the new leadership. Ownership changed yet again in the 1920s, followed by multiple cycles of expanding and shrinking mining activity, interrupted by completely unproductive periods.
DS202203-0363
2021
Schmetzer, K.Schmetzer, K.History of emerald mining in the Habachtal deposit of Austria. Part 1.Gems & Gemology, Vol. 57, 4, pp. 338-371. pdfEurope, Austriaemerald

Abstract: The sources of emeralds used in Roman jewelry as well as jeweled pieces (including crowns and book covers) dating from antiquity to the Middle Ages and before the discovery of the Colombian emerald deposits in the sixteenth century remain an ongoing matter of controversy. Two potential localities dominate the discussion: the mines in the Eastern Desert of Egypt and the Habachtal deposit in Austria. The first published reference to the Habachtal emerald occurrence dates to 1797. The majority of publications from the nineteenth and twentieth centuries agree that Samuel Goldschmidt, a jeweler from Vienna, purchased the mountain area in which the Habachtal emerald occurrence is located and commenced mining soon thereafter, in the early 1860s. A later period from the mid-1890s to about 1914 is frequently mentioned, in which the mine was owned and worked by an English company. However, further details regarding both periods and the various transitions of ownership and further circumstances of emerald mining before World War I are rarely given and often are not consistent, and activities in the times before the 1860s and between 1870 and 1890 are obscure. Using a wide selection of materials from Austrian and German archives, largely unpublished, the author seeks to trace the history of the Habachtal mine through several centuries and to fill gaps left by existing publications.
DS1985-0592
1985
Schmicke, H.U.Schmicke, H.U., Mertes, H., Viereck, L.Mafic Magmas from the Quaternary Eifel Volcanic FieldsConference Report of The Meeting of The Volcanics Studies Gr, 1P. ABSTRACT.GermanyNephelinite, Melilite
DS2003-0632
2003
Schmickler, B.Jacob, D.E., Schmickler, B., Schulze, D.J.Trace element geochemistry of coesite bearing eclogites from the Roberts VictorLithos, Vol. 71, 2-4, pp. 337-351.South AfricaGeochemistry - deposit
DS200412-0891
2003
Schmickler, B.Jacob, D.E., Schmickler, B., Schulze, D.J.Trace element geochemistry of coesite bearing eclogites from the Roberts Victor kimberlite, Kaapvaal Craton.Lithos, Vol. 71, 2-4, pp. 337-351.Africa, South AfricaGeochemistry - deposit
DS200412-1754
2004
Schmickler, B.Schmickler, B., Jacob, D.E., Foley, S.F.Eclogite xenoliths from the Kuruman kimberlites, South Africa: geochemical fingerprinting of deep subduction and cumulate procesLithos, Vol. 75, 1-2, July pp. 173-207.Africa, South AfricaSubduction, Zero, petrogenetic processes
DS2001-0331
2001
SchmidFranz, L., Romer, Klemd, Schmid, Oberhansli, WagnerEclogite facies quartz veins within metabasites of the Dabie Shan: P T time deformation path... fluid phase..Contributions to Mineralogy and Petrology, Vol. 141, No. 3, June, pp. 322-46.Chinaultra high pressure (UHP) - fluid flow, melting, exhumation
DS2000-0868
2000
Schmid, J.C.Schmid, J.C., Ratschibacher, L., Dong, S.How did the foreland react? Yangtze foreland fold and thrust belt deformation related to exhumation of DabieáShanTerra Nova, Vol. 11, No. 6, pp. 266-72.China, eastern Chinaultra high pressure (UHP) - Dabie Shan, Continental crust
DS1900-0039
1900
Schmid, P.Schmid, P.Beggars on Golden StoolsLondon: Weidenfeld And Nicholson., 326P.South America, Brazil, VenezuelaHistory
DS2001-1030
2001
Schmid, R.Schmid, R.Crustal structure of the eastern Dabie Shan interpreted from deep reflection and shallow tomographic data.Tectonophysics, Vol. 333, No. 3-4, April pp. 347-59.ChinaTectonics, ultra high pressure (UHP)
DS2002-1168
2002
Schmid, R.Oberhansli, R., Matinotti, G., Schmid, R., Liu, X.Preservation of primary volcanic textures in the ultrahigh pressure terrain of Dabie ShanGeology, Vol.30,8,Aug.pp.699-702.ChinaUHP, Deposit - Dabie Shan area
DS2003-1225
2003
Schmid, R.Schmid, R., Romer, R.L., Franz, L., Oberhansli, R., Martinotti, G.Basement cover sequences within the UHP unit of the Dabie ShanJournal of Metamorphic Geology, Vol. 21, 6, pp. 531-38.ChinaUHP
DS200412-1755
2003
Schmid, R.Schmid, R., Romer, R.L., Franz, L., Oberhansli, R., Martinotti, G.Basement cover sequences within the UHP unit of the Dabie Shan.Journal of Metamorphic Geology, Vol. 21, 6, pp. 531-38.ChinaUHP
DS1994-0379
1994
Schmid, S.M.Davidson, C., Schmid, S.M., Hollister, L.S.Role of melt during deformation in the deep crustTerra Nova, Vol. 6, No. 2, pp. 133-142.GlobalMelting, Subduction
DS201910-2306
2019
Schmid, S.M.Van Hinsbergen, D.J.J., Torsvik, T.H., Schmid, S.M., Matenco, L.C., Maffione, M., Vissers, R.L.M., Gurer, D., Spakman, W.Orogenic architecture of the Mediterranean region and kinematic reconstruction of its tectonic evolution since the Triassic. AtriaGondwana Research, in press available 427p.Europecraton

Abstract: The basins and orogens of the Mediterranean region ultimately result from the opening of oceans during the early break-up of Pangea since the Triassic, and their subsequent destruction by subduction accommodating convergence between the African and Eurasian Plates since the Jurassic. The region has been the cradle for the development of geodynamic concepts that link crustal evolution to continental break-up, oceanic and continental subduction, and mantle dynamics in general. The development of such concepts requires a first-order understanding of the kinematic evolution of the region for which a multitude of reconstructions have previously been proposed. In this paper, we use advances made in kinematic restoration software in the last decade with a systematic reconstruction protocol for developing a more quantitative restoration of the Mediterranean region for the last 240 million years. This restoration is constructed for the first time with the GPlates plate reconstruction software and uses a systematic reconstruction protocol that limits input data to marine magnetic anomaly reconstructions of ocean basins, structural geological constraints quantifying timing, direction, and magnitude of tectonic motion, and tests and iterations against paleomagnetic data. This approach leads to a reconstruction that is reproducible, and updatable with future constraints. We first review constraints on the opening history of the Atlantic (and Red Sea) oceans and the Bay of Biscay. We then provide a comprehensive overview of the architecture of the Mediterranean orogens, from the Pyrenees and Betic-Rif orogen in the west to the Caucasus in the east and identify structural geological constraints on tectonic motions. We subsequently analyze a newly constructed database of some 2300 published paleomagnetic sites from the Mediterranean region and test the reconstruction against these constraints. We provide the reconstruction in the form of 12 maps being snapshots from 240 to 0 Ma, outline the main features in each time-slice, and identify differences from previous reconstructions, which are discussed in the final section.
DS2001-0330
2001
Schmidberger, S.Francis, D., Schmidberger, S.The composition, age and origin of the Canadian continental lithospheric mantle #2Prospectors and Developers Association of Canada (PDAC) Short Course, 23p.Northwest Territories, Manitoba, Saskatchewan, OntarioXenolith - suites, Geochronology
DS2002-1420
2002
Schmidberger, S.Schmidberger, S., Simonetti, A., Francis, D., GariepyProbing Archean lithosphere using the Lu Hf isotope systematics of peridotite xenoliths Somerset Island.Earth and Planetary Science Letters, Vol.197,3-4,pp.245-59.Northwest Territories, Somerset IslandCraton, geochronology, Deposit - Nikos
DS1998-1352
1998
Schmidberger, S. Vladkar.Simonetti, A., Goldstein, S., Schmidberger, S. Vladkar.Geochemical and neodymium, lead, and Strontium isotope dat a from Deccan alkaline complexes -inferences for mantle sources...Journal of Petrology, Vol. 39, No. 11-12, Nov-Dec. pp. 1847-64.IndiaAlkaline rocks - geochemistry, geochronology, Lithosphere - plume
DS1997-1046
1997
Schmidberger, S.S.Simonetti, A., Goldstein, S.L., Schmidberger, S.S.New isotope dat a from Deccan related alkaline igneous complexes India-inferences on mantle sourcesGeological Association of Canada (GAC) Abstracts, India, west centralAlkaline rocks
DS1998-1293
1998
Schmidberger, S.S.Schmidberger, S.S.The nature of the deep mantle roots beneath the Canadian craton: mantle xenolith evidence -Somerset IslGeological Society of America (GSA) Annual Meeting, abstract. only, p.A395-6.Northwest Territories, Somerset IslandCretaceous, garnet-peridotite, Deposit - Nikos
DS1998-1294
1998
Schmidberger, S.S.Schmidberger, S.S., Francis, D.The deep cratonic mantle roots beneath the Canadian craton: mantle xenolith evidence from Somerset Island.Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1340.Northwest Territories, Somerset IslandOrthopyroxene, Deposit - Nikos
DS1998-1295
1998
Schmidberger, S.S.Schmidberger, S.S., Francis, D.lead, neodymium, Strontium, Hafnium isotope dat a for Somerset Island mantle xenoliths - evidence for Archean deep mantle roots...Geological Association of Canada (GAC)/Mineralogical Association of, p. A167. abstract.Northwest Territories, Somerset IslandXenolith - petrology, Nikos kimberlites
DS1999-0633
1999
Schmidberger, S.S.Schmidberger, S.S., Francis, D.Nature of the mantle roots beneath the North American Craton: mantle xenolith evidence from Somerset Island.Lithos, Vol. 48, No. 1-4, Sept. pp. 195-216.Northwest Territories, Somerset IslandXenoliths, Craton
DS2001-1031
2001
Schmidberger, S.S.Schmidberger, S.S., Francis, D.Constraints on the trace element composition of the Archean mantle root beneath Somerset Island, Arctic .Journal of Petrology, Vol. 42, No. 6, pp. 1095-1118.Northwest Territories, Nunavut, Somerset IslandGeochemistry
DS2001-1032
2001
Schmidberger, S.S.Schmidberger, S.S., Simonetti, A., Francis, D.Strontium, neodymium, lead isotopes systematics of mantle xenoliths from Somerset island kimberlites. ( age 100 Ma).Geochimica et Cosmochimica Acta, Vol. 65, No. 22, pp. 4243-55.Northwest Territories, Somerset IslandGeochronology - peridottites, pyroxenite xenoliths, Deposit - Nikos
DS2003-1226
2003
Schmidberger, S.S.Schmidberger, S.S., Simonetti, A., Francis, D.Small scale Sr isotope investigation of clinopyroxenes from peridotite xenoliths by laserChemical Geology, Vol. Sept. 15, pp. 317-329.Somerset IslandGeochronology, Deposit - Nikos
DS2003-1227
2003
Schmidberger, S.S.Schmidberger, S.S., Simonetti,. A., Francis, D.Small scale Sr isotope investigation of clinopyroxenes from peridotite xenoliths by laserChemical Geology, Vol. 199, No. 3-4, pp.317-29.MantleBlank
DS200412-1756
2003
Schmidberger, S.S.Schmidberger, S.S., Simonetti, A., Francis, D.Small scale Sr isotope investigation of clinopyroxenes from peridotite xenoliths by laser ablation MC-ICP-MS implications for maChemical Geology, Vol. 199, no. 3-4, pp.317-29.MantleGeochronology - Nikos
DS200512-0882
2005
Schmidberger, S.S.Purves, M.C., Heaman, L.M., Creaser, R.A., Schmidberger, S.S., Simoneti, A.Origin and isotopic evolution of the Muskox intrusion, Nunavut.GAC Annual Meeting Halifax May 15-19, Abstract 1p.Canada, NunavutLayered intrusion - ultramafic
DS200612-1240
2005
Schmidberger, S.S.Schmidberger, S.S., Heaman, L.M., Simonetti, A., Craser, R.A., Cookenboo, H.O.Formation of Paleoproterozoic eclogitic mantle Slave Province ( Canada): insights from in-situ Hf and U-Pb isotopic analyses of mantle zircons.Earth and Planetary Science Letters, Vol. 240, 3-4, Dec. 15, pp. 621-633.Canada, Northwest TerritoriesJericho, subduction, Archean
DS200712-0951
2007
Schmidberger, S.S.Schmidberger, S.S., Simonetti, A., Heaman, L.M., Creaser, R.A., Whieford, S.Lu Hf in-situ Sr and Pb isotope trace element systematics for mantle eclogites from the Diavik diamond mine: evidence for Paleproterozoic subduction..Earth and Planetary Science Letters, Vol. 254, 1-2, Feb. 15, pp. 55-68.Canada, Northwest TerritoriesDeposit - Diavik, geochronology, Slave Craton
DS1998-1107
1998
SchmidtPalme, H., Borisov, A., Holzheid, SchmidtOrigin and significance of highly siderophile elements in the upper mantle of the earth.Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1127-8.MantleHSE silicate melts
DS2003-1069
2003
SchmidtPersonen, L.J., Elming, Mertansen, Pisarvesky, D' Agrilla Filho, Meert, SchmidtPaleomagnetic configuration of continents during the ProterozoicTectonophysics, Vol. 375, 1-4, pp. 289-324.MantleMagnetics
DS200412-1532
2003
SchmidtPersonen, L.J., Elming, Mertansen, Pisarvesky, D' Agrilla Filho, Meert, Schmidt, Abrahamsen, BylundPaleomagnetic configuration of continents during the Proterozoic.Tectonophysics, Vol. 375, 1-4, pp. 289-324.MantleMagnetics
DS201112-0053
2011
SchmidtBallhaus, C., Laurenz, V., Fonseca, R., Munker, C., Albarede, Rohrbach, Schmidt, Jochum, Stoll, Weis, HelmyLate volatile addition to Earth.Goldschmidt Conference 2011, abstract p.475.MantleW and Cr elements
DS200412-1015
2003
Schmidt, A.Klemd, R., Martin, J., Schmidt, A., Barton, J.M.P-T path constraints from calc silicate metapelitic rocks east of the Venetia kimberlite pipes, Central Zone, Limpopo Belt, SoutSouth African Journal of Geology, Vol. 106, 2-3, pp. 129-148.Africa, South AfricaDeposit - Venetia, metamorphism, geochronology
DS200612-1241
2006
Schmidt, A.Schmidt, A., Weyer, S., Brey, G.P.BSE reservoirs: insights from Nb/Ta of rutile bearing eclogites.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 10, abstract only.MantleEclogite - niobium, tantalum
DS200712-0952
2007
Schmidt, A.Schmidt, A., Weyer, S., Xiao, Y., Hoefs, J., Brey, G.P.Lu Hf geochronology of eclogites from the Dabie Sulu terrain: constraints on the timing of eclogite facies metamorphism.Plates, Plumes, and Paradigms, 1p. abstract p. A894.ChinaUHP
DS200812-1019
2008
Schmidt, A.Schmidt, A., Weyer, S., John, T., Brey, G.P.Nb Ta systematics of orogenic eclogites.Goldschmidt Conference 2008, Abstract p.A833.MantleEclogite
DS200812-1020
2008
Schmidt, A.Schmidt, A., Weyer, S., Mezger, K., Scherer, E.E., Xiao, Y., Hoefs, J., Brey, G.P.Rapid eclogization of the Dabie Sulu UHP terrane: constraints from Lu Hf garnet geochronology.Earth and Planetary Science Letters, Vol. 273, 1-2, Aug. 30, pp. 203-213.ChinaUHP
DS200812-1021
2008
Schmidt, A.Schmidt, A., Weyer, S., Mezger, K., Scherer, E.E., Xiao, Y., Hoefs, J., Brey, G.P.Rapid eclogitization of the Dabie Sulu UHP terrane: constraints from Lu Hf garnet geochronology.Earth and Planetary Science Letters, In press available, 49p.ChinaUHP
DS200912-0674
2009
Schmidt, A.Schmidt, A., Weyer, S., John, T., Brey, G.P.HFSE systematics of rutile bearing eclogites: new insights into subduction zone processes and implications for the Earth's HPSE budget.Geochimica et Cosmochimica Acta, Vol. 73, 2, pp. 455-468.MantleSubduction
DS201112-0929
2011
Schmidt, A.Schmidt, A., Mezger, K., O'Brien, P.J.The time of eclogite formation in the ultrahigh pressure rocks of the Sulu terrane constraints from Lu-Hf garnet geochronology.Lithos, Vol. 125, pp. 743-756ChinaUHP
DS2002-1421
2002
Schmidt, B.C.Schmidt, B.C., Keppler, H.Experimental evidence for high noble gas solubilities in silicate melts under mantle pressure.Earth and Planetary Science Letters, Vol.195,3-4,pp.277-90.MantleExperimental petrology
DS201603-0402
2016
Schmidt, B.C.Moussallam, Y., Florian, P., Corradini, D., Morizet, Y., Sator, N., Vuilleumier, R., Guillot, B., Iacono-Marziano, G., Schmidt, B.C., Gaillard, F.The molecular structure of melts along the carbonatite-kimberlite-basalt compositional joint: CO (sub 2) and polymerisation.Earth and Planetary Science Letters, Vol. 434, pp. 129-140.TechnologyPetrology - experimental

Abstract: Transitional melts, intermediate in composition between silicate and carbonate melts, form by low degree partial melting of mantle peridotite and might be the most abundant type of melt in the asthenosphere. Their role in the transport of volatile elements and in metasomatic processes at the planetary scale might be significant yet they have remained largely unstudied. Their molecular structure has remained elusive in part because these melts are difficult to quench to glass. Here we use FTIR, Raman, 13C and 29Si NMR spectroscopy together with First Principle Molecular Dynamic (FPMD) simulations to investigate the molecular structure of transitional melts and in particular to assess the effect of CO2 on their structure. We found that carbon in these glasses forms free ionic carbonate groups attracting cations away from their usual ‘depolymerising’ role in breaking up the covalent silicate network. Solution of CO2 in these melts strongly modifies their structure resulting in a significant polymerisation of the aluminosilicate network with a decrease in NBO/Si of about 0.2 for every 5 mol% CO2 dissolved. This polymerisation effect is expected to influence the physical and transport properties of transitional melts. An increase in viscosity is expected with increasing CO2 content, potentially leading to melt ponding at certain levels in the mantle such as at the lithosphere-asthenosphere boundary. Conversely an ascending and degassing transitional melt such as a kimberlite would become increasingly fluid during ascent hence potentially accelerate. Carbon-rich transitional melts are effectively composed of two sub-networks: a carbonate and a silicate one leading to peculiar physical and transport properties.
DS201704-0642
2017
Schmidt, C.Navon, O., Wirth, R., Schmidt, C., Matat Jabion, B., Schreiber, A., Emmanuel, S.Solid molecular nitrogen ( delta -N2) inclusions in Juin a diamonds: exsolution at the base of the transition zone.Earth and Planetary Science Letters, Vol. 464, pp. 237-247.South America, BrazilDeposit - Juina
DS202006-0941
2020
Schmidt, C.Nasdala, L., Schmidt, C.Applications of raman spectroscopy in mineralogy and geochemistry.Elements, Vol. 16, pp. 99-104.Africa, South Africadeposit - Finsch

Abstract: The application of Raman spectroscopy for the identification and characterization of minerals and related materials has increased appreciably during recent years. Raman spectroscopy has proven to be a most valuable and versatile analytical tool. Successful applications cover virtually all the mineralogical sub-disciplines, and have become more numerous in geochemistry. We present a general summary of present applications, illustrated by selected examples. In addition, we briefly point out several aspects of spectral acquisition, data reduction, and interpretation of Raman results that are important for the application of Raman spectroscopy as a reliable analytical tool.
DS1989-0589
1989
Schmidt, C.J.Harlan, S.S., Geissman, J.W., Snee, L.W., Schmidt, C.J.Paleomagnetism of Proterozoic mafic dikes, southwest Montana foreland, USANew Mexico Bureau of Mines Bulletin., Continental Magmatism Abstract Volume, Held, Bulletin. No. 131, p. 121 Abstract held June 25-July 1MontanaPaleomagnetics, Dike
DS1996-1260
1996
Schmidt, C.J.Schmidt, C.J., Stone, D.S.Influence of lower Proterozoic boundary of the Wyoming province on trend sand kineamatics of Laramide deform..Geological Society of America, Abstracts, Vol. 28, No. 7, p. A-447.WyomingBoundary, Structure - fault
DS1994-1862
1994
Schmidt, C.S.Vityk, M.O., Bodnar, R.J., Schmidt, C.S.Fluid inclusions as tectonothermomobarometers: relation between P-T history and reequilibrium morphologyGeology, Vol. 22, No. 8, August pp. 731-734GlobalGeothermometry, Crustal thickening
DS1998-1365
1998
Schmidt, G.Snow, J.E., Schmidt, G.Constraints on Earth accretion deduced from noble metals in the oceanicmantleNature, Vol. 391, No. 6663, Jan. 8, pp. 166-168MantleAccretion, Noble metals, gold, PlatinuM.
DS2003-1228
2003
Schmidt, G.Schmidt, G., Witt Eiscksen, G., Palme, H., Seek, H., Spettel, B., Kratz, K.L.Highly siderophile elements ( PGE Re and Au) in mantle xenoliths from the west EiffelChemical Geology, Vol. 196, No. 1-4, pp. 77-105.GermanyXenoliths
DS200412-1757
2003
Schmidt, G.Schmidt, G., Witt Eiscksen, G., Palme, H., Seek, H., Spettel, B., Kratz, K.L.Highly siderophile elements ( PGE Re and Au) in mantle xenoliths from the west Eiffel volcanic field, Germany.Chemical Geology, Vol. 196, no. 1-4, pp. 77-105.Europe, GermanyXenoliths
DS2000-0585
2000
Schmidt, G./Lorand, J.P., Schmidt, G./, Jratz, K.L.Highly siderophile element geochemistry of the Earth's mantle: new dat a Lanzo and Ronda orogenic peridotiteLithos, Vol. 53, No. 2, Aug. pp.149-64.GlobalPeridotites, Geochemistry
DS1991-1253
1991
Schmidt, K.Okrusch, M., Matthes, S., Klemd, R., O'Brien, P.J., Schmidt, K.Eclogites at the north-western margin of the Bohemian Massif: a reviewEuropean Journal of Mineralogy, Vol. 3, No. 4, pp. 707-730EuropeEclogites, Mineral chemistry
DS1995-1673
1995
Schmidt, K.Schmidt, K., Cull, J.P.Application of Euler deconvolution and a neural network system as interpretation aids for three component TEM.Exploration Geophysics, Vol. 26, No. 2-3, June 1, pp. 154-157.AustraliaGeophysics, Downhole TEM data -not specific to diamonds
DS1990-1313
1990
Schmidt, K._H.Schmidt, K._H., Schermerhorn, L.J.G.Geomorphology and geochemistry of the Foum-el-Kous ankaratite, southMoroccoTerra, Abstracts of Crustal Dynamics: Pathways and Records held Bochum FRG, Vol. 2, December p. 57GlobalAlkaline rocks, Ankaratite
DS1995-0503
1995
Schmidt, K.H.Ergenzinger, P., Schmidt, K.H.Dynamics and geomorphology of mountain rivers #2Springer, 326pGlobalGeomorphology, Book -ad
DS1999-0634
1999
Schmidt, K.H.Schmidt, K.H., Bottazi, P., Mengel, K.Trace element partitioning between phlogopite, clinopyroxenes and leucite lamproite melt.Earth and Planetary Science Letters, Vol. 168, No. 3-4, May 15, pp. 287-300.GlobalGeochemistry, Lamproite
DS2002-0094
2002
Schmidt, K.S.Bakker, W.H., Schmidt, K.S.hyper spectral edge filtering for measuring homogeneity of surface cover types. ( saltmarsh)Journal of Photogrammetry and Remote Sensing, Vol.56,4,pp.246-56.HollandRemote sensing - hyperspectral (not specific to diamond, Image filtering application
DS200812-0736
2008
Schmidt, M.Medard, E., Schmidt, M.Composition of low degree hydrous melts of fertile spinel or garnet bearing lherzolite.Goldschmidt Conference 2008, Abstract p.A617.TechnologyMelting
DS201706-1088
2017
Schmidt, M.Kupers, S.A., Schmidt, M., Campbell, I.A petrographic and geochemical analysis of the KRVY kimberlite, Lake Timiskaming kimberlite field, Ontario Canada.GSA Annual Meeting, 1p. AbstractCanada, Ontariodeposit - Krvy

Abstract: The Lake Tamiskaming Kimberlite Field, in Ontario, Canada is host to multiple kimberlite pipes, such as the KRVY Kimberlite Pipe, south of Latchford, Ontario. Drill core of this kimberlite pipe, collected by Temex Resources Corporation, confirmed the diamondiferous nature, with microdiamonds being retrieved. Thin sections of the drill core samples suggest the pipe is highly altered through serpentinization. Euhedral to subhedral grains of mica, such as phlogopite and biotite, compose the phenocryst and matrix components of the samples. Electron microprobe analysis will be used to determine the composition of the micas, in order to constrain the origin conditions of these grains, determining if the grains originate from crustal or magmatic components. Micro X-ray Diffraction will determine the mineralogy in the samples. Other likely xenocrystic minerals include quartz, etc. Textural and compositional attributes of the KRVY Kimberlite will be compared to data collected from the approximately twelve known kimberlite pipes within 25 kilometres (15.5 miles) of the specified kimberlite in order to find similarities or patterns. Geochemical analysis will better constrain the formation conditions of this pipe and allow comparison with other surrounding pipes in the Lake Tamiskaming Kimberlite Field.
DS2003-1229
2003
Schmidt, M.D.Schmidt, M.D., Bowring, S.A.Ultrahigh temperature metamorphism in the lower crust during NeoarcheanGeological Society of America Bulletin, Vol. 115, 5, pp. 533-48.South AfricaGeochronology, tectonics - not specific to diamonds
DS200412-1758
2003
Schmidt, M.D.Schmidt, M.D., Bowring, S.A.Ultrahigh temperature metamorphism in the lower crust during Neoarchean Ventersdorp rifting and magmatism Kaapvaal Craton, southGeological Society of America Bulletin, Vol. 115, 5, pp. 533-48.Africa, South AfricaGeochronology, tectonics - not specific to diamonds
DS201212-0253
2012
Schmidt, M.V.Golubkova, A., Schmidt, M.V.The role of sediment derived carbonatitic melts in the origin of carbonated K-rich mantle domains.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractMantleCarbonatite
DS1998-1057
1998
Schmidt, M.W.Mysen, B.O., Ulmer, P., Schmidt, M.W.The Upper mantle near convergent plate boundariesReviews in Mineralogy, Vol. 37, pp. 97-138.MantleGeodynamics, Plate tectonics - boundary
DS1998-1296
1998
Schmidt, M.W.Schmidt, M.W., Poli, S.Experimentally based water budgets for dehydrating slabs and sequences for arc magmas generation.Earth and Planetary Science Letters, Vol. 163, No. 1-4, Nov. pp. 361-379.MantleMagmas, Slabs
DS2002-1274
2002
Schmidt, M.W.Poli, S., Schmidt, M.W.Petrology of subducted slabsAnnual of Review Earth Planetary Science, Vol.30,pp. 207-235.MantleSubduction
DS2002-1275
2002
Schmidt, M.W.Poli, S., Schmidt, M.W.Petrology of subducted slabsAnnual Review of Earth and Planetary Sciences, Vol.30,pp. 207-235.MantleSubduction
DS2003-1095
2003
Schmidt, M.W.Poli, S., Schmidt, M.W.Petrology of subducted slabsAnnual Review of Earth and Planetary Sciences, Vol. 30, 29p.GlobalSubduction
DS200412-0713
2004
Schmidt, M.W.Green, D.H., Schmidt, M.W., Hibberson, W.O.Island arc ankaramites: primitive melts from fluxed refractory lherzolitic mantle.Journal of Petrology, Vol. 45, 2, pp. 391-403.MantlePetrology
DS200412-0991
2004
Schmidt, M.W.Kessel, R., Ulmer, P., Pettke, T., Schmidt, M.W., Thompson, A.B.A novel approach to determine high pressure high temperature fluid and melt compositions using diamond trap experiments.American Mineralogist, Vol. 89, June pp. 1078-1086.TechnologyUHP, freezing approach
DS200412-0992
2004
Schmidt, M.W.Kessel, R., Ulmer, P., Pettke, T., Schmidt, M.W., Thompson, A.B.Phase relations and second critical endpoint in eclogite H2O at 4-6 GPa and 900-1400C.Lithos, ABSTRACTS only, Vol. 73, p. S56. abstractMantleMineral chemistry
DS200412-0993
2004
Schmidt, M.W.Kessel, R., Ulmer, P., Pettke, T., Schmidt, M.W., Thompson, A.B.A novel approach to determine high pressure high temperature fluid and melt compositions using diamond trap experiments.American Mineralogist, Vol. 89, 6, pp. 1078-1086.TechnologyPetrology, experimental UHP
DS200612-0059
2006
Schmidt, M.W.Auzanneau, E., Vielzeuf, D., Schmidt, M.W.Experimental evidence of decompression melting exhumation of subducted continental crust.Contributions to Mineralogy and Petrology, Vol. 152, 2, pp. 125-148.MantleSubduction
DS200612-0060
2006
Schmidt, M.W.Auzanneau, E., Vielzeuf, E., Schmidt, M.W.Experimental evidence of decompression melting during exhumation of subducted continental crust.Contributions to Mineralogy and Petrology, Vol. 152, 2, pp. 125-148.MantleSubduction
DS200612-0691
2005
Schmidt, M.W.Kessel, R., Schmidt, M.W., Ulmer,P., Pettke, T.Trace element signature of subduction zone fluids, melts and supercritical liquids at 120-180 km depth.Nature, Vol. 437, pp. 724-MantleSubduction
DS200612-0900
2006
Schmidt, M.W.Medard, E., Schmidt, M.W., Schiano, P., Ottolini, L.Melting of amphibole bearing wehrlites: an experimental study on the origin of ultra calcic nepheline normative melts.Journal of Petrology, Vol. 47, 3, pp. 481-504.TechnologyWehrlite
DS200612-0901
2006
Schmidt, M.W.Medard, E., Schmidt, M.W., Schiano, P., Ottolini, L.Melting of amphibole bearing wehrlites: an experimental study on the origin of ultra-calcic nepheline normative melts.Journal of Petrology, Vol. 47, 3, pp. 481-504.TechnologyWehrlite
DS200712-0711
2007
Schmidt, M.W.Melekhova, E., Schmidt, M.W., Ulmer, P., Pettke, T.The composition of liquids coexisting with Dense Hydrous Magnesium silicates and the second critical endpoint in the MgO SiO2 H2O system.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p.184.TechnologyWater
DS200712-0712
2007
Schmidt, M.W.Melekhova, E., Schmidt, M.W., Ulmer, P., Pettke, T.The composition of liquids coexisting with Dense Hydrous Magnesium silicates and the second critical endpoint in the MgO SiO2 H2O system.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p.184.TechnologyWater
DS200812-1022
2008
Schmidt, M.W.Schmidt, M.W.Primary melts from slab metasomatized mantle - the interplay of metasomatic agent and mantle fertility.Goldschmidt Conference 2008, Abstract p.A835.MantleMetasomatism - kamafugites
DS200812-1169
2008
Schmidt, M.W.Thomsen, T.B., Schmidt, M.W.Melting of carbonated pelites at 2.5 - 5.0 GPA silicate carbonatite liquid immiscibility, and potassium carbon metasomatism of the mantle.Earth and Planetary Science Letters, Vol. 267, 1-2, pp. 17-31.MantleCarbonatite
DS200912-0027
2009
Schmidt, M.W.Bagdassarov, N., Solferino, G., Golabek, G.J., Schmidt, M.W.Centrifuge assisted percolation of Fe-S melts in partially molten peridotite: time constraints for planetary core formation.Earth and Planetary Science Letters, Vol. 288, 1-2, pp. 84-95.MantleMelting
DS200912-0264
2009
Schmidt, M.W.Grassi, D., Schmidt, M.W.Melting of carbonated pelites at 9-13 GPa: generating potassic carbonatitic melts for mantle metasomatism.Goldschmidt Conference 2009, p. A461 Abstract.MantleMetasomatism
DS200912-0640
2009
Schmidt, M.W.Rohrbach, A., Schmidt, M.W., Ballhaus, C.Carbonate stability in the Earth's lower mantle and redox melting across the 660 km discontinuity.Goldschmidt Conference 2009, p. A1113 Abstract.MantleMelting
DS200912-0675
2009
Schmidt, M.W.Schmidt, M.W.Melting subducted carbonated pelites, magma hybridization in the mantle and carbonatites - the Italian ultrapotassics.Goldschmidt Conference 2009, p. A1179 Abstract.Europe, ItalyCarbonatite
DS201012-0027
2009
Schmidt, M.W.Auzanneau, E., Schmidt, M.W., Vielzeuf, D., Connolly, J.A.D.Titanium in phengite: a geobarometer for high temperature eclogites.Contributions to Mineralogy and Petrology, Vol. 159, 1, pp. 1-24.MantleGeothermometry
DS201012-0249
2010
Schmidt, M.W.Grassi, D., Schmidt, M.W.Melting of carbonated pelites at 8-13 GPa: generating K-rich carbonatites for mantle metasomatism.Contributions to Mineralogy and Petrology, In press available, 23p.MantleSubduction, potassic magmatism
DS201112-0367
2011
Schmidt, M.W.Ghosh, S., Schmidt, M.W.Stability of phase D at high pressure and temperature: implications for the role of fluids in the deep mantle.Goldschmidt Conference 2011, abstract p.912.MantleWater, subduction
DS201112-0384
2011
Schmidt, M.W.Grassi, D., Schmidt, M.W.Melting of carbonates pelites at 8-13 GPa: generating K rich carbonatites for mantle metasomatism.Contributions to Mineralogy and Petrology, Vol. 162, 1p. pp. 169-191.TechnologyMetasomatism
DS201112-0385
2011
Schmidt, M.W.Grassi, D., Schmidt, M.W.Melting of carbonated pelites from 70 to 700 km depth.Journal of Petrology, Vol. 52, 4, pp. 765-789.MantleMelting - not specific to diamonds
DS201112-0397
2011
Schmidt, M.W.Gysi, A.P., Jagoutz, O., Schmidt, M.W., Targuisti, K.Petrogenesis of pyroxenites and melt infiltrations in the ultramafic complex of Beni Bousera, northern Morocco.Journal of Petrology, Vol. 52, 9, pp. 1679-1735.Africa, MoroccoMelting, delamination
DS201112-0398
2011
Schmidt, M.W.Gysi, A.P., Jagoutz, O., Schmidt, M.W., Targuisti, K.Petrogenesis of pyroxenites and melt infiltrations in the ultramafic complex of Beni Bousera, northern Morocco.Journal of Petrology, Vol. 52, 9, pp. 1679-1735.Africa, MoroccoMetasomatism
DS201112-0487
2011
Schmidt, M.W.Jung, D.Y., Schmidt, M.W.Solid solution behaviour of CaSiO3 and MgSiO3 perovskites.Physics and Chemistry of Minerals, Vol. 38, 4, pp. 311-319.MantleInterior structure
DS201112-0877
2011
Schmidt, M.W.Rohrbach, A., Schmidt, M.W.Redox freezing and melting of carbonates in the deep mantle and the role of transient carbides.Goldschmidt Conference 2011, abstract p.1743.MantleCarbonatite
DS201112-0878
2011
Schmidt, M.W.Rohrbach, A., Schmidt, M.W.Redox freezing and melting in the Earth's deep mantle resulting from carbon-iron redox coupling.Nature, March 23, 3p.MantleGeophysics - seismics, subduction
DS201212-0447
2012
Schmidt, M.W.Martin, L.H.J., Schmidt, M.W., Mattsson, H.B., Ulmer, P., Hametner, K., Gunther, D.Element partitioning between immiscible carbonatite-kamafugite melts with application to the Italian ultrapotassic suite.Chemical Geology, Vol. 320-321 pp. 96-112.Europe, ItalyCarbonatite
DS201212-0626
2012
Schmidt, M.W.Schmidt, M.W., Forien, M., Solferino, G., Bagdassarov, N.Setting and compaction of olivine in basaltic magmas: an experimental study on the time scales of cumulate formation.Contributions to Mineralogy and Petrology, Vol. 164, 6, pp. 959-976.MantleMagmatism
DS201212-0627
2012
Schmidt, M.W.Schmidt, M.W., Rohrbach, A., Gao, C., Connolly, J.A.D.The role of redox equilibration temperatures during carbon transfer in the mantle and the stability of carbides in the mantle.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractMantleRedox
DS201312-0053
2013
Schmidt, M.W.Ballhaus, C., Laurenz, V., Munker, C., Fonseca, R.O.C., Albarede, F., Rohrbach, A., Lagos, M., Schmidt, M.W., Jochum, K-P., Stoll, B., Weis, U., Helmy, H.M.The U /Pb ratio of the Earth's mantle - a signature of late volatile addition.Earth and Planetary Interiors, Vol. 362, pp. 237-245.MantleMelting
DS201312-0433
2013
Schmidt, M.W.Jagoutz, O., Schmidt, M.W.The composition of the foundered complement to the continental crust and re-evaluation of fluxes in arcs.Earth and Planetary Science Letters, Vol. 371-372, June pp. 177-190.MantleGeochronology
DS201312-0579
2013
Schmidt, M.W.Martin, L.H.J., Schmidt, M.W., Mattsson, H.B., Guenther, D.Element partitioning between immiscible carbonatite and silicate melts for dry and H2O bearing systems at 1-3 Gpa.Journal of Petrology, Vol. 54, pp. 2301-2338.MantleCarbonatite
DS201412-0288
2014
Schmidt, M.W.Ghosh, S., Schmidt, M.W.Melting of Phase D in the lower mantle and implications for recycling and storage of H2O in the deep mantle.Geochimica et Cosmochimica Acta, Vol. 145, pp. 72-88.MantleWater storage
DS201412-0750
2014
Schmidt, M.W.Rohrbach, A., Ghosh, S., Schmidt, M.W., Wijnrans, C.H., Klemme, S.The stability of Fe-Ni carbides in the Earth's mantle: evidence for a low Fe-Ni-C melt fraction in the deep mantle.Earth and Planetary Science Letters, Vol. 388, pp. 211-221.MantleMelting - mentions diamond
DS201501-0030
2014
Schmidt, M.W.Schmidt, M.W., Gao, C., Golubkova, A., Rohrbach, A., Connolly, J.A.D.Natural moissanite ( SiC) - a low temperature mineral formed from highly fractionated ultra-reducing COH-fluids.Progress in Earth and Planetary Science, Vol. 1, pp. 27-Moissanite
DS201606-1089
2016
Schmidt, M.W.Golubkova, A., Schmidt, M.W., Connolly, J.A.D.Ultra reducing conditions in average mantle peridotites and in podiform chromitites: a thermodynamic model for moissanite (SiC) formation.Contributions to Mineralogy and Petrology, in press available, 17p.MantlePeridotite

Abstract: Natural moissanite (SiC) is reported from mantle-derived samples ranging from lithospheric mantle keel diamonds to serpentinites to podiform chromitites in ophiolites related to suprasubduction zone settings (Luobusa, Dongqiao, Semail, and Ray-Iz). To simulate ultra-reducing conditions and the formation of moissanite, we compiled thermodynamic data for alloys (Fe-Si-C and Fe-Cr), carbides (Fe3C, Fe7C3, SiC), and Fe-silicides; these data were augmented by commonly used thermodynamic data for silicates and oxides. Computed phase diagram sections then constrain the P-T-fO2 conditions of SiC stability in the upper mantle. Our results demonstrate that: Moissanite only occurs at oxygen fugacities 6.5-7.5 log units below the iron-wustite buffer; moissanite and chromite cannot stably coexist; increasing pressure does not lead to the stability of this mineral pair; and silicates that coexist with moissanite have X Mg > 0.99. At upper mantle conditions, chromite reduces to Fe-Cr alloy at fO2 values 3.7-5.3 log units above the moissanite-olivine-(ortho)pyroxene-carbon (graphite or diamond) buffer (MOOC). The occurrence of SiC in chromitites and the absence of domains with almost Fe-free silicates suggest that ultra-reducing conditions allowing for SiC are confined to grain scale microenvironments. In contrast to previous ultra-high-pressure and/or temperature hypotheses for SiC origin, we postulate a low to moderate temperature mechanism, which operates via ultra-reducing fluids. In this model, graphite-/diamond-saturated moderately reducing fluids evolve in chemical isolation from the bulk rock to ultra-reducing methane-dominated fluids by sequestering H2O into hydrous phases (serpentine, brucite, phase A). Carbon isotope compositions of moissanite are consistent with an origin of such fluids from sediments originally rich in organic compounds. Findings of SiC within rocks mostly comprised by hydrous phases (serpentine + brucite) support this model. Both the hydrous phases and the limited diffusive equilibration of SiC with most minerals in the rocks indicate temperatures below 700-800 °C. Moissanite from mantle environments is hence a mineral that does not inform on pressure but on a low to moderate temperature environment involving ultra-reduced fluids. Any mineral in equilibrium with SiC could only contain traces of Fe2+ or Cr3+.
DS201606-1128
2016
Schmidt, M.W.Weidendorfer, D., Schmidt, M.W., Mattson, H.R.Fractional crystallization of Si-undersaturated alkaline magmas leading to unmixing of carbonatites on Brava Island ( Cape Verde) and a general model of carbonatite genesis in alkaline magma suites.Contributions to Mineralogy and Petrology, Vol. 171, pp. 43-50.Europe, Cape Verde IslandsCarbonatite

Abstract: The carbonatites of Brava Island, Cape Verde hot spot, allow to investigate whether they represent small mantle melt fractions or form through extreme fractionation and/or liquid immiscibility from CO2-bearing silicate magmas. The intrusive carbonatites on Brava Island are part of a strongly silica-undersaturated pyroxenite, ijolite, nephelinite, nepheline syenite, combeite-foiditite, carbonatite series. The major and trace element composition of this suite is reproduced by a model fractionating olivine, clinopyroxene, perovskite, biotite, apatite, titanite, sodalite and FeTi oxides, all present as phenocrysts in the rocks corresponding to their fractionation interval. Fractionation of ~90 wt% crystals reproduces the observed geochemical trend from the least evolved ultramafic dikes (bulk X Mg = 0.64) to syenitic compositions. The modelled fractional crystallization leads to alkali enrichment, driving the melt into the carbonatite-silicate miscibility gap. An initial CO2 content of 4000 ppm is sufficient to saturate in CO2 at the point where the rock record suggests continuing unmixing carbonatites from nephelinites to nepheline syenites after 61 wt% fractionation. Such immiscibility is also manifested in carbonatite and silicate domains on a hand-specimen scale. Furthermore, almost identical primary clinopyroxene, biotite and carbonate compositions from carbonatites and nephelinites to nepheline syenites substantiate their conjugate character and our unmixing model. The modelled carbonatite compositions correspond to the natural ones except for their much higher alkali contents. The alkali-poor character of the carbonatites on Brava and elsewhere is likely a consequence of the release of alkali-rich CO2 + H2O fluids during final crystallization, which cause fenitization in adjacent rocks. We propose a general model for carbonatite generation during alkaline magmatism, where the fractionation of heavily Si-undersaturated, alkaline parent melts results in alkali and CO2 enrichment in the evolving melt, ultimately leading to immiscibility between carbonatites and evolved Si-undersaturated alkaline melts. Early saturation in feldspathoids or feldspars would limit alkali enrichment preventing the formation of carbonatites. The complete and continuous fractionation line from almost primitive melts to syenitic compositions on Brava underlines the possibly important role of intrusives for hot spot volcanism.
DS201706-1110
2017
Schmidt, M.W.Weidendorfer, D., Schmidt, M.W., Mattsson, H.B.A common origin of carbonatite magmas.Geology, Vol. 45, 6, pp. 507-510.Africa, Tanzaniacarbonatite - Oldoinyo Lengai

Abstract: The more than 500 fossil Ca-carbonatite occurrences on Earth are at odds with the only active East African Rift carbonatite volcano, Oldoinyo Lengai (Tanzania), which produces Na-carbonatite magmas. The volcano's recent major explosive eruptions yielded a mix of nephelinitic and carbonatite melts, supporting the hypothesis that carbonatites and spatially associated peralkaline silicate lavas are related through liquid immiscibility. Nevertheless, previous eruption temperatures of Na-carbonatites were 490-595 °C, which is 250-450 °C lower than for any suitable conjugate silicate liquid. This study demonstrates experimentally that moderately alkaline Ca-carbonatite melts evolve to Na-carbonatites through crystal fractionation. The thermal barrier of the synthetic Na-Ca-carbonate system, held to preclude an evolution from Ca-carbonatites to Na-carbonatites, vanishes in the natural system, where continuous fractionation of calcite + apatite leads to Na-carbonatites, as observed at Oldoinyo Lengai. Furthermore, saturating the Na-carbonatite with minerals present in possible conjugate nephelinites yields a parent carbonatite with total alkali contents of 8-9 wt%, i.e., concentrations that are realistic for immiscible separation from nephelinitic liquids at 1000-1050 °C. Modeling the liquid line of descent along the calcite surface requires a total fractionation of ?48% calcite, ?12% apatite, and ?2 wt% clinopyroxene. SiO2 solubility only increases from 0.2 to 2.9 wt% at 750-1200 °C, leaving little leeway for crystallization of silicates. The experimental results suggest a moderately alkaline parent to the Oldoinyo Lengai carbonatites and therefore a common origin for carbonatites related to alkaline magmatism.
DS201707-1383
2017
Schmidt, M.W.Wiedendorfer, D., Schmidt, M.W., Mattsson B.A common origin of carbonatite magmas. Oldoinyo LengaiGeology, Vol. 45, 6, pp. 507-510.Africa, Tanzaniacarbonatite

Abstract: The more than 500 fossil Ca-carbonatite occurrences on Earth are at odds with the only active East African Rift carbonatite volcano, Oldoinyo Lengai (Tanzania), which produces Na-carbonatite magmas. The volcano’s recent major explosive eruptions yielded a mix of nephelinitic and carbonatite melts, supporting the hypothesis that carbonatites and spatially associated peralkaline silicate lavas are related through liquid immiscibility. Nevertheless, previous eruption temperatures of Na-carbonatites were 490–595 °C, which is 250–450 °C lower than for any suitable conjugate silicate liquid. This study demonstrates experimentally that moderately alkaline Ca-carbonatite melts evolve to Na-carbonatites through crystal fractionation. The thermal barrier of the synthetic Na-Ca-carbonate system, held to preclude an evolution from Ca-carbonatites to Na-carbonatites, vanishes in the natural system, where continuous fractionation of calcite + apatite leads to Na-carbonatites, as observed at Oldoinyo Lengai. Furthermore, saturating the Na-carbonatite with minerals present in possible conjugate nephelinites yields a parent carbonatite with total alkali contents of 8–9 wt%, i.e., concentrations that are realistic for immiscible separation from nephelinitic liquids at 1000–1050 °C. Modeling the liquid line of descent along the calcite surface requires a total fractionation of ?48% calcite, ?12% apatite, and ?2 wt% clinopyroxene. SiO2 solubility only increases from 0.2 to 2.9 wt% at 750–1200 °C, leaving little leeway for crystallization of silicates. The experimental results suggest a moderately alkaline parent to the Oldoinyo Lengai carbonatites and therefore a common origin for carbonatites related to alkaline magmatism.
DS201708-1582
2017
Schmidt, M.W.Weidendorfer, D., Schmidt, M.W., Mattsson, H.B.A common origin of carbonatite magmas.Geology, Vol. 45, 6, pp. 507-510.Africa, Tanzaniacarbonatites

Abstract: The more than 500 fossil Ca-carbonatite occurrences on Earth are at odds with the only active East African Rift carbonatite volcano, Oldoinyo Lengai (Tanzania), which produces Na-carbonatite magmas. The volcano’s recent major explosive eruptions yielded a mix of nephelinitic and carbonatite melts, supporting the hypothesis that carbonatites and spatially associated peralkaline silicate lavas are related through liquid immiscibility. Nevertheless, previous eruption temperatures of Na-carbonatites were 490–595 °C, which is 250–450 °C lower than for any suitable conjugate silicate liquid. This study demonstrates experimentally that moderately alkaline Ca-carbonatite melts evolve to Na-carbonatites through crystal fractionation. The thermal barrier of the synthetic Na-Ca-carbonate system, held to preclude an evolution from Ca-carbonatites to Na-carbonatites, vanishes in the natural system, where continuous fractionation of calcite + apatite leads to Na-carbonatites, as observed at Oldoinyo Lengai. Furthermore, saturating the Na-carbonatite with minerals present in possible conjugate nephelinites yields a parent carbonatite with total alkali contents of 8–9 wt%, i.e., concentrations that are realistic for immiscible separation from nephelinitic liquids at 1000–1050 °C. Modeling the liquid line of descent along the calcite surface requires a total fractionation of ?48% calcite, ?12% apatite, and ?2 wt% clinopyroxene. SiO2 solubility only increases from 0.2 to 2.9 wt% at 750–1200 °C, leaving little leeway for crystallization of silicates. The experimental results suggest a moderately alkaline parent to the Oldoinyo Lengai carbonatites and therefore a common origin for carbonatites related to alkaline magmatism.
DS201709-2060
2017
Schmidt, M.W.Stamm, N., Schmidt, M.W.Asthenospheric kimberlites: volatile contents and bulk compositions at 7 Gpa.Earth and Planetary Science Letters, Vol. 474, pp. 309-321.Canada, Nunavutdeposit - Jericho

Abstract: During ascent, kimberlites react with the lithospheric mantle, entrain and assimilate xenolithic material, loose volatiles and suffer from syn- and post-magmatic alteration. Consequently, kimberlite rocks deviate heavily from their primary melt. Experiments at 7 GPa, 1300–1480?°C, 10–30 wt% CO2 and 0.46 wt% H2O on a proposed primitive composition from the Jericho kimberlite show that saturation with a lherzolitic mineral assemblage occurs only at 1300–1350?°C for a carbonatitic melt with <8 wt% SiO2 and >35 wt% CO2. At asthenospheric temperatures of >1400?°C, where the Jericho melt stays kimberlitic, this composition saturates only in low-Ca pyroxene, garnet and partly olivine. We hence forced the primitive Jericho kimberlite into multiple saturation with a lherzolitic assemblage by adding a compound peridotite. Saturation in olivine, low- and high-Ca pyroxene and garnet was obtained at 1400–1650 °C (7 GPa), melts are kimberlitic with 18–29 wt% SiO2 + Al2O3, 22.1–24.6 wt% MgO, 15–27 wt% CO2 and 0.4–7.1 wt% H2O; with a trade-off of H2O vs. CO2 and temperature. Melts in equilibrium with high-Ca pyroxene with typical mantle compositions have ?2.5 wt% Na2O, much higher than the commonly proposed 0.1–0.2 wt%. The experiments allow for a model of kimberlite origin in the convective upper mantle, which only requires mantle upwelling that causes melting at the depth where elemental carbon (in metal, diamond or carbide) converts to CO2 (at ?250 km). If primary melts leading to kimberlites contain a few wt% H2O, then adiabatic temperatures of 1400–1500?°C would yield asthenospheric mantle melts that are kimberlitic (>18 wt% SiO2 + Al2O3) but not carbonatitic (<10 wt% SiO2 + Al2O3) in composition, carbonatites only forming 100–200?°C below the adiabat. These kimberlites represent small melt fractions concentrating CO2 and H2O and then acquire part of their chemical signature by assimilation/fractionation during ascent in the subcratonic lithosphere.
DS201806-1247
2018
Schmidt, M.W.Schmidt, M.W., Weidendorfer, D.Carbonatites in oceanic hotspots.Geology, Vol. 46, 5, pp. 435-438.Mantlecarbonatite

Abstract: An analysis of the global array of ocean island volcanics shows that carbonatites only form in those hotspots that have the lowest Si- and highest alkali-contents among their primitive melts, such as the Cape Verde and Canary (Islands) hotspots. Fractionated melts from these two hotspots reach, at any given SiO2, several wt% higher total alkali contents than for ocean islands without carbonatites. This is because their strongly silica-undersaturated primitive melts fractionate at low SiO2 to high alkali contents, driving the evolving melt into the silicate-carbonatite miscibility gap. Instead, moderately alkaline magmas fractionate toward the alkali-feldspar thermal divide and do not reach liquid immiscibility. Low SiO2 and high alkalis are the combined result of comparatively deep and low-degree mantle melting, the latter is corroborated by the highest high-field-strength and rare earth element concentrations in the Cape Verde and Canary primitive melts. CO2 in the source facilitates low melt SiO2, but enrichment in CO2 relative to other hotspots is not required. The oceanic hotspots with carbonatites are among those with the thickest thermal lithosphere supporting a deep origin of their asthenospheric parent melts, an argument that could be expanded to continental hotspot settings.
DS201810-2378
2018
Schmidt, M.W.Speelmanns, I.M., Schmidt, M.W., Liebske, C.Nitrogen solubility in core materials.Geophysical Research Letters, Vol. 45, 15, pp. 7434-7443. doi.org/10.1029/ 2018GLO79130Mantlenitrogen

Abstract: On the early Earth nitrogen was redistributed between three prevailing reservoirs: the core forming metal, the silicate magma ocean, and the atmosphere. To shed light on the behavior of N during core segregation, we have experimentally determined N solubilities in Fe?dominated metal melts at high temperatures and pressures (1200-1800 °C, 0.4-9.0 GPa) using high?pressure devices. Based on our experimental results a model has been developed to describe N solubility into metal melts as a function of pressure and temperature. The model suggests that core?forming metal melts can dissolve N quantities that are as high as the Earth's core density deficit. However, the N concentrations in the core?forming metal are dependent on the accretionary scenario and its partitioning with silicate magma ocean; our solubilities provide an upper limit for possible N concentrations within the Earth's core. Nevertheless, this study shows that N in the modern mantle will largely dissolve in its small metal fraction and not in the dominating silicates.
DS201903-0547
2019
Schmidt, M.W.Speelmanns, I.M., Schmidt, M.W., Liebske, C.The almost lithophile character of nitrogen during core formation.Earth and Planetary Science Letters, Vol. 510, pp. 186-197.Mantlenitrogen

Abstract: Nitrogen is a key constituent of our atmosphere and forms the basis of life, but its early distribution between Earth reservoirs is not well constrained. We investigate nitrogen partitioning between metal and silicate melts over a wide range of conditions relevant for core segregation during Earth accretion, i.e. 1250-2000 °C, 1.5-5.5 GPa and oxygen fugacities of ?IW-5.9 to ?IW-1.4 (in log units relative to the iron-wüstite buffer). At 1250 °C, 1.5 GPa, ranges from 14 ± 0.1 at ?IW-1.4 to 2.0 ± 0.2 at ?IW-5, N partitioning into the core forming metal. Increasing pressure has no effect on , while increasing temperature dramatically lowers to 0.5 ± 0.15 at ?IW-4. During early core formation N was hence mildly incompatible in the metal. The partitioning data are then parameterised as a function of temperature and oxygen fugacity and used to model the evolution of N within the two early prevailing reservoirs: the silicate magma ocean and the core. Depending on the oxidation state during accretion, N either behaves lithophile or siderophile. For the most widely favoured initially reduced Earth accretion scenario, N behaves lithophile with a bulk partition coefficient of 0.17 to 1.4, leading to 500-700 ppm N in closed-system core formation models. However, core formation from a magma ocean is very likely accompanied by magma ocean degassing, the core would thus contain ?100 ppm of N, and hence, does not constitute the missing N reservoir. Bulk Earth N would thus be 34-180 ppm in the absence of other suitable reservoirs, >98% N of the chondritic N have hence been lost during accretion.
DS201903-0552
2019
Schmidt, M.W.Weidendorfer, D., Schmidt, M.W., Mattsson, H.B.Mineral resorption triggers explosive mixed silicate-carbonatite eruptions.Earth and Planetary Science Letters, Vol. 510, pp. 219-230.Africa, Tanzaniadeposit - Oldoinyo Lengai

Abstract: Historic eruptions of Earth's only active carbonatite volcano, Oldoinyo Lengai (Tanzania), have repeatedly switched from low energy carbonatite lava extrusion to highly energetic explosive silicate volcanism, most recently in 1966-67 and 2007-08. The explosive eruptions produce strongly Si-undersaturated peralkaline silicate ashes with unusually high (Na + K)/Al of 3.4-6.3 when compared to the average peralkalinity of ?0.8 in the East African Rift System. A series of experiments in the carbonatite-clinopyroxene system at 750-1150 °C, 0.1 GPa, reveal that augitic clinopyroxene breaks down peritectically at >900 °C yielding strongly peralkaline conjugated silicate- and carbonatite melts. The clinopyroxene-derived silicate melt dissolves (Na,K)2O from the (Na,K)2CO3-component of the carbonatite leading to high peralkalinities and to liberation of excess CO2, since the solubility of carbon dioxide in silicate liquids is ?1 wt.% at subvolcanic pressures. Carbonatite injection into subvolcanic clinopyroxene-rich crystal mushes hence explains the occurrence of strongly peralkaline silicate melts and provides a mechanism for CO2-driven explosive eruptions. The silicate melt compositions mostly depend on the (Na + K)/Ca ratio of the intruding carbonatite, the silicate ashes erupted in 1966-67 and 2007-08 require an interaction of a clinopyroxene-rich crystal mush with a slightly less evolved alkali-carbonatite than presently erupted at Oldoinyo Lengai. The mechanism identified here, where mineral breakdown induced melt hybridization triggers volatile saturation and highly explosive volcanism is generally applicable to igneous systems that involve carbonatites or other low-viscosity CO2-bearing alkaline silicate melts.
DS201904-0738
2019
Schmidt, M.W.Galli, A., Grassi, D., Sartori, G., Gianola, O., Burg, J-P., Schmidt, M.W.Jurassic carbonatite and alkaline magmatism in the Ivrea zone ( European Alps) related to the breakup of Pangea.Geology, Vol. 47, 3, pp. 199-202..Europecarbonatite

Abstract: We report on pipe-like bodies and dikes of carbonate rocks related to sodic alkaline intrusions and amphibole mantle peridotites in the Ivrea zone (European Southern Alps). The carbonate rocks have bulk trace-element concentrations typical of low-rare earth element carbonatites interpreted as cumulates of carbonatite melts. Faintly zoned zircons from these carbonate rocks contain calcite inclusions and have trace-element compositions akin to those of carbonatite zircons. Laser ablation-inductively coupled plasma-mass spectrometry U-Pb zircon dating yields concordant ages of 187 ± 2.4 and 192 ± 2.5 Ma, coeval with sodic alkaline magmatism in the Ivrea zone. Cross-cutting relations, ages, as well as bulk and zircon geochemistry indicate that the carbonate rocks are carbonatites, the first ones reported from the Alps. Carbonatites and alkaline intrusions are comagmatic and were emplaced in the nascent passive margin of Adria during the Early Jurassic breakup of Pangea. Extension caused partial melting of amphibole-rich mantle domains, yielding sodic alkaline magmas whose fractionation led to carbonatite-silicate melt immiscibility. Similar occurrences in other rifts suggest that small-scale, sodic and CO2-rich alkaline magmatism is a typical result of extension and decompression-driven reactivation of amphibole-bearing lithospheric mantle during passive continental breakup and the evolution of magma-poor rifts.
DS201904-0754
2019
Schmidt, M.W.Kueter, N., Lilley, M.D., Schmidt, M.W., Bernasconi, S.M.Experimental carbonatite/graphite carbon isotope fractionation and carbonate/graphite geothermometry.Geochimica et Cosmochimica Acta, in press available 38p.Mantlecarbonatite

Abstract: Carbon isotope exchange between carbon-bearing high temperature phases records carbon (re-) processing in the Earth's interior, where the vast majority of global carbon is stored. Redox reactions between carbonate phases and elemental carbon govern the mobility of carbon, which then can be traced by its isotopes. We determined the carbon isotope fractionation factor between graphite and a Na2CO3-CaCO3 melt at 900-1500 °C, 1 GPa using a piston-cylinder device. The failure to isotopically equilibrate preexisting graphite led us to synthesize graphite anew from organic material during the melting of the carbonate mixture. Graphite growth proceeds by (1) decomposition of organic material into globular amorphous carbon, (2) restructuring into nano-crystalline graphite, and (3) recrystallization into hexagonal graphite flakes. Each transition is accompanied by carbon isotope exchange with the carbonate melt. High-temperature (1200 - 1500 °C) equilibrium isotope fractionation with type (3) graphite can be described by (temperature T in K). As the experiments do not yield equilibrated graphite at lower temperatures, we combined the ?1200 °C experimental data with those derived from upper amphibolite and lower granulite facies carbonate-graphite pairs (Kitchen and Valley, 1995, Valley and O'Neil, 1981). This yields the general fractionation function usable as a geothermometer for solid or liquid carbonate at ? 600 °C. Similar to previous observations, lower-temperature experiments (?1100 °C) deviate from equilibrium. By comparing our results to diffusion and growth rates in graphite, we show that at ?1100 °C carbon diffusion is slower than graphite growth, hence equilibrium surface isotope effects govern isotope fractionation between graphite and carbonate melt and determine the isotopic composition of newly formed graphite. The competition between diffusive isotope exchange and growth rates requires a more careful interpretation of isotope zoning in graphite and diamond. Based on graphite crystallization rates and bulk isotope equilibration, a minimum diffusivity of Dgraphite = 2x10-17 m2s-1 for T >1150 °C is required. This value is significantly higher than calculated from experimental carbon self-diffusion constants (?1.6x10-29 m2s-1) but in good agreement with the value calculated for mono-vacancy migration (?2.8x10-16 m2s-1).
DS201905-1054
2019
Schmidt, M.W.Kueter, N., Lilley, M.D., Schmidt, M.W., Bernasconi, S.M.Experimental carbonatite/graphite carbon isotope fractionation and carbonate/graphite geochronology.Geochimica et Cosmochimica Acta, Vol. 253, pp. 290-306.Mantlecarbonatite
DS201906-1307
2019
Schmidt, M.W.Kueter, N., Lilley, M.D., Schmidt, M.W., Bernasconi, S.M.Experimental carbonatite/graphite carbon isotope fractionation and carbonate/graphite geothermometry.Geochimica et Cosmochimica Acta, Vol. 253, pp. 290-306.Mantlegeothermometry

Abstract: Carbon isotope exchange between carbon-bearing high temperature phases records the carbon (re-) processing in the Earth's interior, where the vast majority of global carbon is stored. Redox reactions between carbonate phases and elemental carbon govern the mobility of carbon, which then can be traced by its isotopes. We determined the carbon isotope fractionation factor between graphite and a Na2CO3-CaCO3 melt at 900-1500?°C and 1?GPa; The failure to isotopically equilibrate preexisting graphite led us to synthesize graphite anew from organic material during the melting of the carbonate mixture. Graphite growth proceeds by (1) decomposition of organic material into globular amorphous carbon, (2) restructuring into nano-crystalline graphite, and (3) recrystallization into hexagonal graphite flakes. Each transition is accompanied by carbon isotope exchange with the carbonate melt. High-temperature (1200-1500?°C) equilibrium isotope fractionation with type (3) graphite can be described by (temperature T in K). As the experiments do not yield equilibrated bulk graphite at lower temperatures, we combined the ?1200?°C experimental data with those derived from upper amphibolite and lower granulite facies carbonate-graphite pairs (Kitchen and Valley, 1995; Valley and O'Neil, 1981). This yields the general fractionation function usable as a geothermometer for solid or liquid carbonate at ?600?°C. Similar to previous observations, lower-temperature experiments (?1100?°C) deviate from equilibrium. By comparing our results to diffusion and growth rates in graphite, we show that at ?1100?°C carbon diffusion is slower than graphite growth, hence equilibrium surface isotope effects govern isotope fractionation between graphite and carbonate melt and determine the isotopic composition of newly formed graphite. The competition between diffusive isotope exchange and growth rates requires a more careful interpretation of isotope zoning in graphite and diamond. Based on graphite crystallization rates and bulk isotope equilibration, a minimum diffusivity of Dgraphite?=?2?×?10?17 m2s?1 for T?>?1150?°C is required. This value is significantly higher than calculated from experimental carbon self-diffusion constants (?1.6?×?10?29?m2?s?1) but in good agreement with the value calculated for mono-vacancy migration (?2.8?×?10?16?m2?s?1).
DS202004-0524
2020
Schmidt, M.W.Kueter, N., Schmidt, M.W., Lilley, M.D., Bernasconi, S.Kinetic carbon isotope fractionation links graphite and diamond precipitation to reduced fluid sources.Earth and Planetary Science Letters, Vol. 529, 115848 12p. PdfGlobalcarbon

Abstract: At high temperatures, isotope partitioning is often assumed to proceed under equilibrium and trends in the carbon isotope composition within graphite and diamond are used to deduce the redox state of their fluid source. However, kinetic isotope fractionation modifies fluid- or melt-precipitated mineral compositions when growth rates exceed rates of diffusive mixing. As carbon self-diffusion in graphite and diamond is exceptionally slow, this fractionation should be preserved. We have hence performed time series experiments that precipitate graphitic carbon through progressive oxidization of an initially CH4-dominated fluid. Stearic acid was thermally decomposed at 800 °C and 2 kbar, yielding a reduced COH-fluid together with elemental carbon. Progressive hydrogen loss from the capsule caused CH4 to dissociate with time and elemental carbon to continuously precipitate. The newly formed C0, aggregating in globules, is constantly depleted by ‰ in 13C relative to the methane, which defines a temperature dependent kinetic graphite-methane 13C/12C fractionation factor. Equilibrium fractionation would instead yield graphite heavier than the methane. In dynamic environments, kinetic isotope fractionation may control the carbon isotope composition of graphite or diamond, and, extended to nitrogen, could explain the positive correlation of and sometimes observed in coherent diamond growth zones. 13C enrichment trends in diamonds are then consistent with reduced deep fluids oxidizing upon their rise into the subcontinental lithosphere, methane constituting the main source of carbon.
DS202010-1884
2020
Schmidt, M.W.Wiedendorfer, D., Manning, C.E., Schmidt, M.W.Carbonate melts in the hydrous upper mantle.Contributions to Mineralogy and Petrology, doi.org/10.1007/ s00410-020-01708 17p. Pdf Mantlecarbonatite

Abstract: Carbonatite compositions resulting from melting of magnesian calcite?+?olivine?+?clinopyroxene were experimentally determined in the system CaO-MgO-SiO2-CO2-H2O as a function of temperature and bulk H2O contents at 1.0 and 1.5 GPa. The melting reaction and melt compositions were found to be highly sensitive to H-loss or -gain during experiments. We hence designed a new hydrogen-trap technique, which provided sufficient control to obtain consistent results. The nominally dry solidus temperatures at 1.0 and 1.5 GPa are 1225-1250 °C and 1275-1300 °C, respectively. At 1.0 GPa, the solidus temperature decreases with H2O increasing to 3.5 wt% (1025-1050 °C), then remains approximately constant at higher H2O concentrations. Our nominally dry solidus temperatures are up to 140 °C higher than in previous studies that did not take measures to limit hydrogen infiltration and hence suffered from H2O formation in the capsule. The near-solidus anhydrous melts have 7-8 wt% SiO2 and molar Ca/(Ca?+?Mg) of 0.78-0.82 (XCa). Melting temperatures decrease by as much as 200 °C with increasing XH2O in the coexisting COH-fluid. Concomitantly, near-solidus melt compositions change with increasing bulk H2O from siliceous Ca-rich carbonate melts to Mg-rich silico-carbonatites with up to 27.8 wt% SiO2 and 0.55 XCa. The continuous compositional array of Ca-Mg-Si carbonatites demonstrates the efficient suppression of liquid immiscibility in the alkali-free system. Diopside crystallization was found to be sensitive to temperature and bulk water contents, limiting metasomatic transformation of carbonated upper mantle to wehrlite at 1.0-1.5 GPa to?
DS202102-0187
2021
Schmidt, M.W.Fichtner, C.E., Schmidt, M.W., Liebske, C., Bouvier, A-S., Baumgartner, L.P.Carbon partitioning between metal and silicate melts during Earth accretion.Earth and Planetary Science Letters, Vol. 554, doi.org/10.1016/ j.epsl.2020. 116659 12p . PdfMantlecarbon

Abstract: In the accreting Earth and planetesimals, carbon was distributed between a core forming metallic melt, a silicate melt, and a hot, potentially dense atmosphere. Metal melt droplets segregating gravitationally from the magma ocean equilibrated near its base. To understand the distribution of carbon, its partitioning between the two melts is experimentally investigated at 1.5-6.0 GPa, 1300-2000 °C at oxygen fugacities of ?0.9 to ?1.9 log units below the iron-wuestite reference buffer (IW). One set of experiments was performed in San Carlos olivine capsules to investigate the effect of melt depolymerization (NBO/T), a second set in graphite capsules to expand the data set to higher pressures and temperatures. Carbon concentrations were analyzed by secondary ionization mass spectrometry (SIMS) and Raman spectra were collected to identify C-species in the silicate melt. Partition coefficients are governed by the solubility of C in the silicate melt, which varies from 0.01 to 0.6 wt%, while metal melts contain ?7 wt% C in most samples. C solubility in the silicate melt correlates strongly with NBO/T, which, in olivine capsules, is mostly a function of temperature. Carbon partition coefficients DCmetal/silicate at 1.5 GPa, 1300-1750 °C decrease from 640(49) to 14(3) with NBO/T increasing from 1.04 to 3.11. For the NBO/T of the silicate Earth of 2.6, DCmetal/silicate is 34(9). Pressure and oxygen fugacity show no clear effect on carbon partitioning. The present results differ from those of most previous studies in that carbon concentrations in the silicate melt are comparatively higher, rendering C to be about an order of magnitude less siderophile, and the discrepancies may be attributed to differences in the experimental protocols. Applying the new data to a magma ocean scenario, and assuming present day mantle carbon mantle concentrations from 120 to 795 ppm, implies that the core may contain 0.4-2.6 wt% carbon, resulting in 0.14-0.9 wt% of this element for the bulk Earth. These values are upper limits, considering that some of the carbon in the modern silicate Earth has very likely been delivered by the late veneer.
DS1990-1314
1990
Schmidt, N.Schmidt, N.Plate tectonics and the Gulf of California regionArizona Geology, Vol. 20, No. 2, Summer, pp. 1-4CaliforniaTectonics, Sedimentation
DS201512-1965
2015
Schmidt, N.Schmidt, N., Kramers, P.The Gahcho Kue mine dewatering experience, winter 2014-2015.43rd Annual Yellowknife Geoscience Forum Abstracts, abstract p. 93.Canada, Northwest TerritoriesDeposit - Gahcho Kue

Abstract: Construction of the De Beers Gahcho Kué Mine required that a portion of Kennady Lake be dewatered to provide access to kimberlite pipes on the lakebed. The Construction Water Management Plan considered an initial dewatering volume of approximately 18.7 Mm3, to be discharged to two downstream waterbodies (Lake N11 and Kennady Lake Area 8). This dewatering was originally planned to occur during the open water season, after the spring freshet peak. The project received its Type A Water Licence from the Mackenzie Valley Land and Water Board on September 24, 2014, and before that date it had become apparent that winter dewatering would be required to prevent a significant delay in the project development. Potential adverse impacts related to winter dewatering were identified and were primarily related to aufeis development. Aufeis is defined as an ice deposit, formed by vertical growth of layers as thin flows of water are exposed to freezing temperatures. These may have adverse effects on erosion, fish and fish habitat. Action levels for winter dewatering were developed, based on site-specific hydrological characteristics, and were included in the Aquatic Effects Monitoring Program for the Mine. This allowed field measurements to be compared to action levels during the dewatering program. Field measurements included telemetry to monitor lake hydrostatic water surface elevations, as well as periodic visits to the receiving lake outlets and downstream areas to examine ice and flow conditions. Winter dewatering commenced on December 20, 2014, with pumping to Kennady Lake Area 8. Pumping was suspended on January 4, 2015, as the action level for that location was approached. Approximately 779,000 m3 of water was released over 16 days. Dewatering discharges were then pumped to Lake N11, with pumping commencing on February 1, 2015 and continuing through the winter period, as the action level for that location was not exceeded. Over the 103 day period through May 14, 2015, approximately 6,021,000 m3 of water was released. A total of 6,800,000 m3 of water was discharged from Kennady Lake over the winter dewatering period, or about 36% of the planned initial dewatering volume. Winter and subsequent open-water season reconnaissance did not identify any adverse effects due to winter dewatering. This presentation will discuss winter dewatering risks, action level development, field program observations, and factors contributing to the overall success of the program.
DS1991-1005
1991
Schmidt, N.H.Lloyd, G.E., Schmidt, N.H., Mainprice, D., Prior, D.J.Crystallographic texturesMineralogical Magazine, Vol. 55, pp. 331-345GlobalTextures, Crystallography -review not specific to diamonds
DS201112-0930
2011
Schmidt, P.Schmidt, P., Smith, D.The Elder carbonatite complex, Canada, Quebec.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.135.Canada, QuebecEldor
DS201112-0931
2011
Schmidt, P.Schmidt, P., Smith, D.The Elder carbonatite complex, Canada, Quebec.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.135.Canada, QuebecEldor
DS201112-0932
2011
Schmidt, P.Schmidt, P., Smith, D., Markl, G.The Eldor carbonatite complex, Quebec, Canada.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterCanada, QuebecCarbonatite
DS1986-0699
1986
Schmidt, P.C.Sahoo, N., Mishra, K.C., Das, T.P., Schmidt, P.C.Vacancy associated model for anomalous muonium in diamond, silicon andgermaniuM.Hyperfine Interact, Vol. 32, No. 1-4, pp. 619-624GlobalCrystallography, Diamond
DS200712-0953
2006
Schmidt, P.W.Schmidt, P.W., Williams, G.E., Camacho, A., Lee, J.K.W.Assembly of Proterozoic Australia: implications of a revised pole for the 1070 Ma Alcurra dyke swarm, central Australia.Geophysical Journal International, Vol. 167, 2, pp. 626-634.AustraliaPaleomagnetism
DS201412-0780
2013
Schmidt, P.W.Schmidt, P.W.A review of Precambrian paleomagnetism of Australia: Paleogeography, supercontinents, glaciations and true polar wander.Gondwana Research, in press availableAustraliaGeophysics - magnetics
DS1990-1315
1990
Schmidt, R.L.Schmidt, R.L.Advances in hardrock mining -methodsEngineering and Mining Journal, Vol. 191, No. 10, October pp. 36-38GlobalMining methods, Brief overview
DS1990-0590
1990
Schmidt, S.Gotze, H-J., Lahmeyer, B., Schmidt, S., Strunk, S., Araneda, M.Central Andes gravity dat a baseEos, Vol. 71, No. 16, April 17, pp. 401, 406-407Andes, Chile, ArgentinaGeophysics- gravity, Database
DS201012-0674
2010
Schmidt, S.Schmidt, S., Nagel, T.J., Froitzheim, N.A new occurrence of microdiamond bearing metamorphic rocks, SW Rhodopes, Greece.European Journal of Mineralogy, Vol. 22, 2, pp. 189-198.Europe, GreeceMetamorphic diamonds
DS200412-1759
2004
Schmidt, T.Schmidt, T., Green, D.H., Hibberson, W.O.Ultra calcic magmas generated from Ca depleted mantle: an experimental study on the origin of ankaramites.Journal of Petrology, Vol. 45, 3, pp. 531-554.MantleMagmatism, melt inclusions - not specific to diamonds
DS1975-0452
1977
Schmidt, U.Archer, A.R., Schmidt, U.Mineralized Breccias of Early Proterozoic Age Bonnet Plume River District, Yukon Territory.Archer, Cathro And Associates, Preprint From The Canadian Institute of Mining, Metallurgy And Petroleum (cim) District, 16P. 3 FIGS.Canada, YukonRelated Rocks, Diatremes, Mountain
DS1975-0677
1978
Schmidt, U.Archer, A.R., Schmidt, U.Mineralized Breccias of Early Proterozoic Age, Bonnet Plume river District, Yukon Territory.The Canadian Mining and Metallurgical Bulletin (CIM Bulletin) ., Vol. 71, No. 796, AUGUST PP. 53-58.Canada, YukonCopper, Porphyry
DS1975-0179
1975
Schmidt, W.Safranovskii, I.I., Schmidt, W.Relationships between the crystallography of diamonds and their SOURCE[ In: Industrieminerale. Vortaege des berg und hutten maennischem tages @Freiberger Forschungshefts, ReiheIn: Industrieminerale. Vortaege des berg und huttenmaennischem tages, Mineralogie-geochemie, Vol. 296, pp.19-30. *GerRussiaDiamond Morphology
DS1984-0633
1984
Schmidt, W.Schmidt, W.Diamond: Mineralogic Properties of an Industrial Mineral.(in Portugese)Ciencia e Technologia, (in Portugese)., Vol. 7, pp. 16-26BrazilIndustrial Diamond
DS201810-2381
2018
Schmidt. M.W.Stamm, N., Schmidt. M.W., Szymanowski, D., von Quadt, A., Mohapi, T., Fourie, A.Primary petrology, mineralogy and age of the Letseng-la-Terae kimberlite ( Lesotho), southern Africa) and parental magmas of Group 1 kimberlites.Contributions to Mineralogy and Petrology, Vol. 173, pp. 76- doi.org/10.1007/ s00410-018-1502-1Africa, Lesothodeposit - Letseng

Abstract: The Letšeng-la-Terae kimberlite (Lesotho), famous for its large high-value diamonds, has five distinct phases that are mined in a Main and a Satellite pipe. These diatreme phases are heavily altered but parts of a directly adjacent kimberlite blow are exceptionally fresh. The blow groundmass consists of preserved primary olivine with Fo86?88, chromite, magnesio-ulvöspinel and magnetite, perovskite, monticellite, occasional Sr-rich carbonate, phlogopite, apatite, calcite and serpentine. The bulk composition of the groundmass, extracted by micro-drilling, yields 24-26 wt% SiO2, 20-21 wt% MgO, 16-19 wt% CaO and 1.9-2.1 wt% K2O, the latter being retained in phlogopite. Without a proper mineral host, groundmass Na2O is only 0.09-0.16 wt%. However, Na-rich K-richterite observed in orthopyroxene coronae allows to reconstruct a parent melt Na2O content of 3.5-5 wt%, an amount similar to that of highly undersaturated primitive ocean island basanites. The groundmass contains 10-12 wt% CO2, H2O is estimated to 4-5 wt%, but volatiles and alkalis were considerably reduced by degassing. Mg# of 77.9 and 530 ppm Ni are in equilibrium with olivine phenocrysts, characterize the parent melt and are not due to olivine fractionation. 87Sr/86Sr(i)?=?0.703602-0.703656, 143Nd/144Nd(i)?=?0.512660 and 176Hf/177Hf(i)?=?0.282677-0.282679 indicate that the Letšeng kimberlite originates from the convective upper mantle. U-Pb dating of groundmass perovskite reveals an emplacement age of 85.5?±?0.3 (2?) Ma, which is significantly younger than previously proposed for the Letšeng kimberlite.
DS200512-0712
2005
Schmidt-Aursch, C.Mechita, C., Schmidt-Aursch, C., Jokat, W.The crustal structure of central East Greenland- I. From the Caledonian orogen to the Tertiary igneous province.Geophysical Journal International, Vol. 160, 2, pp. 736-752.Europe, GreenlandTectonics - not specific to diamonds
DS200512-0713
2005
Schmidt-Aursch, C.Mechita, C., Schmidt-Aursch, C., Jokat, W.The crustal structure of central East Greenland- II. From the Precambrian Shield to the recent mid-oceanic ridges.Geophysical Journal International, Vol. 160, 2, pp. 753-760.Europe, GreenlandTectonics - not specific to diamonds
DS1981-0369
1981
Schmidt-Thome, P.Schmidt-Thome, P.Is the Fisch River Graben of Southwest Africa (namibia) The Trace of a Graben Structure?Geologische Rundschau, Vol. 70, No. 2, PP. 499-503.Southwest Africa, NamibiaGeotectonics
DS1910-0212
1911
Schmiedel, K.Schmiedel, K.Vortrag Ueber Seinen Aufenthalt in ChinaFreiberger Geol. Ges. Jber., Vol. 4, PP. 42-56.China, ShandongDiamond
DS201903-0542
2019
Schmiedel, T.Schmiedel, T., Gailland, O., Haug, O.T., Dumazer, G., Breikreuz, C.Coulomb failure of Earth's brittle crust controls growth, emplacement and shapes of igneous sills, saucer-shaped sills and laccoliths.Earth and Planetary Science Letters, Vol. 510, pp. 161-172.MantleMagmatism

Abstract: Tabular intrusions are common features in the Earth's brittle crust. They exhibit a broad variety of shapes, ranging from thin sheet intrusions (sills, saucer-shaped sills, cone sheets), to more massive intrusions (domed and punched laccoliths, stocks). Such a diversity of intrusion shapes reflects different emplacement mechanisms caused by contrasting host rock and magma rheologies. Most current models of tabular intrusion emplacement assume that the host rock behaves purely elastically, whereas numerous observations show that shear failure plays a major role. In this study, we investigate the effects of the host rock's Coulomb properties on magma emplacement by integrating (1) laboratory models using dry Coulomb granular model hosts of variable strength (cohesion) and (2) limit analysis numerical models. Our results show that both sheet and massive tabular intrusions initiate as a sill, which triggers shear failure of its overburden along an inclined shear damage zone at a critical sill radius, which depends on the emplacement depth and the overburden's cohesion. Two scenarios are then possible: (1) if the cohesion of the overburden is significant, opening of a planar fracture along the precursory weakened shear damage zones to accommodate magma flow, leads to the formation of inclined sheets, or (2) if the cohesion of the overburden is negligible, the sill inflates and lifts up the overburden, which is dissected by several faults that control the growth of a massive intrusion. Finally, we derive a theoretical scaling that predicts the thickness-to-radius aspect ratios of the laboratory sheet intrusions. This theoretical prediction shows how sheet intrusion morphologies are controlled by a mechanical equilibrium between the flowing viscous magma and Coulomb shear failure of the overburden. Our study suggests that the emplacement of sheet and massive tabular intrusions are parts of the same mechanical regime, in which the Coulomb behavior of the Earth's brittle crust plays an essential role.
DS1990-1073
1990
SchminckeMuenow, D.W., Garcia, M.O., Aggrey, K.E., Bednarz, U., SchminckeVolatiles in submarine glasses as a discriminant of tectonic origin:application to the Troodos ophioliteNature, Vol. 343, No. 6254, January 11, pp. 159-161CyprusOphiolite, Tectonic origin
DS1990-0493
1990
Schmincke, H.U.Freundt, B., Schmincke, H.U.Leucitite petrogenesis at the Quaternary Hochsimmer volcano East -Eifel volcanic fieldTerra, Abstracts of Crustal Dynamics: Pathways and Records held Bochum FRG, Vol. 2, December p. 23GermanyLeucitite, Petrologenesis
DS1993-0678
1993
Schmincke, H-U.Hoernle, K., Schmincke, H-U.The role of partial melting in the 15 Ma geochemical evolution of GranCanaria: a blob model for the Canary hotspotJournal of Petrology, Vol. 34, No. 3, June pp. 573-599GlobalAlkaline rocks, Geochemistry
DS1993-0679
1993
Schmincke, H-U.Hoernle, K., Schmincke, H-U.The petrology of the tholeiites through melilite nephelinites on Gran Canaria Canary Islands: crystal fractionation, accumulation and depths ofmeltingJournal of Petrology, Vol. 34, No. 3, June pp. 543-572GlobalAlkaline rocks, Geochronology
DS2000-0103
2000
SchmittBouzidi, Y., Schmitt, Burwash, KanasewichCrustal thickness variations across AlbertaGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000 Conference, 4p. abstractAlbertaGeophysics - seismics, Tectonics
DS2000-0126
2000
SchmittBurwash, R.A., Chacko, Muehlenbachs, Bouzidi, SchmittLate orogenic continental growth: examples from Western Canadian lithoprobeGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000 Conference, 2p. abstractAlberta, Cordillera, Western CanadaCraton - orogeny
DS201502-0093
2014
Schmitt, A.Robinson, P.T., Trumbull, R.B., Schmitt, A., Yang, J-S., Li, J-W., Zhou, M-F., Erzinger, J., Dare, S., Xiong, F.The origin and significance of crustal minerals in ophiolitic chromitites and peridotites.Gondwana Research, Vol. 27 2, pp. 486-506.Peridotite
DS200712-0415
2007
Schmitt, A.K.Harrison, T.M., Schmitt, A.K.High sensitivity mapping of Ti distributions in Hadean zircons.Earth and Planetary Science Letters, Vol. 261, 1-2, pp. 9-19.Technologygeochronology
DS200712-0954
2007
Schmitt, A.K.Schmitt, A.K., Worner, G.Zircon U-Th ages from Laacher See indicate coeval crystallization of coerupted carbonatite and silicate magmas.Plates, Plumes, and Paradigms, 1p. abstract p. A898.Europe, GermanyCarbonatite
DS200812-0202
2008
Schmitt, A.K.Chamberlain, K.R., Harrison, T.M., Schmitt, A.K., Heaman, L.M., Swapp, S.M., Khudoley, A.K.In situ SIMS microbaddeleyite U Pb dating method for mafic rocks.Goldschmidt Conference 2008, Abstract p.A147.TechnologyGeochronology
DS200812-0448
2008
Schmitt, A.K.Harrison, T.M., Schmitt, A.K., McCulloch, M.T., Lovera, O.M.Evidence of crust during the first 100 m.y. of Earth's history: Lu-Hf, delta18 O, and Ti thermometry results for Hadean zircons.Goldschmidt Conference 2008, Abstract p.A355.MantleGeochronology
DS200812-1023
2008
Schmitt, A.K.Schmitt, A.K., Worner, G., Cooper, K., Zou, H.B.U Th age constraints on processes of differentiation and solidification in carbonatite phonolite associations.Goldschmidt Conference 2008, Abstract p.A836.Africa, Tanzania, Europe, GermanyCarbonatite
DS201212-0777
2012
Schmitt, A.K.Wiellicki, M.M., Harrison, T.M., Schmitt, A.K.Geochemical signatures and magmatic stability of terrestrial impact produced zircons.Earth and Planetary Science Letters, Vol. 321-322, pp. 20-31.MantleImpact structures
DS201512-1993
2015
Schmitt, A.K.Wu, N.W., Schmitt, A.K., Pappalardo, L.U-Th baddeleyite geochronology and its significance to date the emplacement of silica undersaturated magmas.American Mineralogist, Vol. 100, pp. 2082-2090.MantleMagmatism

Abstract: Baddeleyite is a frequently found accessory mineral in silica undersaturated lavas. Because it is typically enriched in uranium, while having low initial lead, baddeleyite has long been a prime target for U-Pb geochronology of mafic rocks. The difficulties in retrieving small baddeleyite grains from volcanic samples and the lack of a detailed understanding of baddeleyite occurrence, however, have limited baddeleyite chronology largely to coarse-grained mafic intrusive rocks. Here, the development of U-Th in situ baddeleyite analysis using secondary ionization mass spectrometry (SIMS) is presented together with an assessment of baddeleyite occurrence in Quaternary silica-undersaturated lavas from Campi Flegrei (Naples, Italy). Samples studied comprise the pre- and post Campanian Ignimbrite (ca. 40 ka) lava domes of Cuma and Punta Marmolite, and Astroni and Accademia, respectively. The in situ sample preparation required initial identification of baddeleyite crystals from sawed and polished rock billets using scanning electron microscope (SEM) backscatter imaging and energy-dispersive X-ray analysis. U-Th baddeleyite isochron ages for intra-caldera Astroni and Accademia lava domes are 5.01+2.61?2.55 ka (MSWD = 2.0; n = 17) and 4.36+1.13?1.12 ka (MSWD = 2.9; n = 24), respectively. The ages for Punta Marmolite (62.4+3.9?3.8 ka; MSWD = 1.2; n = 11) and Cuma (45.9+3.6?3.5 ka; MSWD = 2.2; n = 11) predate the Campanian Ignimbrite. Rapid baddeleyite crystallization at the time of emplacement is supported by petrologic observations that >50% of the baddeleyite crystals documented in this study occur either in vesicles or in vesicle-rich regions of the host lavas whose textures developed over timescales of a few years to a few decades based on microlite crystal size distribution (CSD) analysis. Radiometric U-Th baddeleyite ages are mostly in agreement with previously determined K-Ar eruption ages, except for the Punta Marmolite lava dome whose U-Th baddeleyite age predates the K-Ar age by ca. 15 ka. Baddeleyite thus records eruptive emplacement with little evidence for significant pre-eruptive crystal residence, and has potential as an eruption chronometer for Quaternary silica-undersaturated volcanic rocks.
DS201911-2559
2019
Schmitt, A.K.Schmitt, A.K., Zack, T., Kooijman, E., Logvinova, A.M., Sobolev, N.V.U-Pb ages of rare rutile inclusions in diamond indicate entrapment synchronous with kimberlite formation. MirLithos, in press available, 47p. PdfRussiadeposit - Mir
DS1994-0466
1994
Schmitt, D.R.Dufresne, M.B., Olson, R.A., Schmitt, D.R., et al.The diamond potential of Alberta: a regional synthesis of structural and stratigraphic setting and potential.Alberta Research Council, Open file, 1994-10, $ 85.00AlbertaStructure, Stratigraphy, diamonds
DS2002-0195
2002
Schmitt, D.R.Bouzidi, Y., Schmitt, D.R., Burwash, R.A., Kanasewich, E.Depth migration of deep seismic reflection profiles: crustal thickness variations in Alberta.Canadian Journal of Earth Science, Vol.39,3,Mar.pp.331-50., Vol.39,3,Mar.pp.331-50.AlbertaGeophysics - seismics, Mohorovicic Discontinuity, Alberta Basement Transect
DS2002-0196
2002
Schmitt, D.R.Bouzidi, Y., Schmitt, D.R., Burwash, R.A., Kanasewich, E.Depth migration of deep seismic reflection profiles: crustal thickness variations in Alberta.Canadian Journal of Earth Science, Vol.39,3,Mar.pp.331-50., Vol.39,3,Mar.pp.331-50.AlbertaGeophysics - seismics, Mohorovicic Discontinuity, Alberta Basement Transect
DS1970-0986
1974
Schmitt, H.H.Schmitt, H.H., Swann, G.A., Smith, D.The Buell Park Kimberlite Pipe Northeastern ArizonaIn: Geology of Northern Arizona, Geological Society of America (gsa) Flagstaff, PP. 672-698.ArizonaKimberlite, Colorado Plateau, Rocky Mountains
DS1993-1393
1993
Schmitt, H.R.Schmitt, H.R., Cameron, E.M., Hall, G.E.M., Viave, J.Mobilization of gold into lake sediments from acid and alkaline mineralized environments in the southern Canadian shield: gold in lake sediments andnat.watersJournal of Geochemical Exploration, Vol. 48, No. 3, August pp. 329-358Ontario, Saskatchewan, ManitobaGold geochemistry, Alkaline rocks
DS1990-1316
1990
Schmitt, J.G.Schmitt, J.G., Steidtmann, J.R.Interior ramp supported uplifts: implications for sediment provenance inforeland basinsGeological Society of America (GSA) Bulletin, Vol. 102, No. 4, April pp. 494-501Montana, WyomingTectogenic deposits, Tectonics
DS1994-0994
1994
Schmitt, J.G.Lawton, T.F., Boyer, S.E., Schmitt, J.G.Influence of inherited taper on structural variability and conglomeratedistribution, Cordilleran fold and thrust belt, western United StatesGeology, Vol. 22, No. 4, April pp. 339-342Nevada, CordilleraStructure, Foreland basin
DS1987-0680
1987
Schmitt, J.M.Sigolo, J.B., Boulange, B., Muller, J.P., Schmitt, J.M.Distribution of rare earth elements in a lateritic bauxite profile on an alkaline rock-Passa QuatroMassive.POR.National Technical Information Service DE88704554, AO3 price, 12pBrazilAlkaline rocks
DS1989-0440
1989
Schmitt, J.M.Fortin, P., Trescases, J.J., Melfi, A.J., Schmitt, J.M., Thiryrare earth elements (REE) accumulations in the Curtibia basin, BrasilXiii International Geochemical Exploration Symposium, Rio 89 Brazilian Geochemical, pp. 66-68. AbstractBrazilCarbonatite, Curtiba
DS201905-1023
2019
Schmitt, M.Cutts, J.A., Smit, M.A., Kooijman, E., Schmitt, M.Two stage cooling and exhumation of deeply subducted continents.Tectonics, Vol. 38, 3, pp. 863-877.Mantlesubduction

Abstract: The burial and exhumation of continental crust during collisional orogeny exert a strong control on the dynamics of mountain belts and plateaus. Constraining the rates and style of exhumation of deeply buried crust has proven difficult due to complexities in the local geology and thermochronometric methods typically used. To advance this field, we applied trace?element and U?Pb laser ablation inductively coupled plasma mass spectrometry analyses to rutile from eclogite and amphibolite samples from the Western Gneiss Complex of Norway—an archetypal continental (ultra)high?pressure (UHP) terrane. Peak temperature and timing of midcrustal cooling were constrained for samples collected along a subduction? and exhumation?parallel transect, using Zr?in?rutile thermometry and U?Pb rutile geochronology, respectively. Peak temperatures decrease from 830 °C in the UHP domain to 730 °C at the UHP?HP transition, remain constant at 730 °C across most of the terrane, and decrease to 620 °C at the eclogite?out boundary. U?Pb results show that most of the terrane cooled through 500 °C at 380-375 Ma except for the lowest grade region, where cooling occurred approximately 20 million years earlier. The results indicate that exhumation was a two stage process, involving (1) flexural rebound and slab flattening at depth combined with foreland?directed extrusion, followed by (2) synchronous cooling below 500 °C across the, by then, largely flat?lying Western Gneiss Complex. The latter implies and requires relatively homogeneous mass removal across a large area, consistent with erosion of an overlying orogenic plateau. The Caledonides were at near?equatorial latitudes at the time. A Caledonian paleo?plateau thus may represent a so far unrecognized factor in Devonian and Carboniferous atmospheric circulation and climate forcing.
DS201712-2708
2017
Schmitt, R.S.Nascimento, D.B., Schmitt, R.S., Ribeiro, A., Trouw, R.A.J., Paschier, C.W., Basei, M.A.S.Depositional ages and provenance of the Neoproterozoic Damara Supergroup ( Northwest Namibia): implications for the Angola-Congo and Kalahari cratons connection.Gondwana Research, Vol. 52, pp. 153-171.Africa, Namibiacraton

Abstract: The Damara Orogen is composed of the Damara, Kaoko and Gariep belts developed during the Neoproterozoic Pan-African Orogeny. The Damara Belt contains Neoproterozoic siliciclastic and carbonate successions of the Damara Supergroup that record rift to proto-ocean depositional phases during the Rodinia supercontinent break up. There are two conflicting interpretations of the geotectonic framework of the Damara Supergroup basin: i) as one major basin, composed of the Outjo and Khomas basins, related to rifting in the Angola-Congo-Kalahari paleocontinent or, ii) as two independent passive margin basins, one related to the Angola-Congo and the other to the Kalahari proto-cratons. Detrital zircon provenance studies linked to field geology were used to solve this controversy. U-Pb zircon age data were analyzed in order to characterize depositional ages and provenance of the sediments and evolution of the succession in the northern part of the Outjo Basin. The basal Nabis Formation (Nosib Group) and the base of the Chuos Formation were deposited between ca. 870 Ma and 760 Ma. The upper Chuos, Berg Aukas, Gauss, Auros and lower Brak River formations formed between ca. 760 Ma and 635 Ma. It also includes the time span recorded by the unconformity between the Auros and lower Brak River formations. The Ghaub, upper Brak River, Karibib and Kuiseb formations were deposited between 663 Ma and 590 Ma. The geochronological data indicate that the main source areas are related to: i) the Angola-Congo Craton, ii) rift-related intrabasinal igneous rocks of the Naauwpoort Formation, iii) an intrabasinal basement structural high (Abbabis High), and iv) the Coastal Terrane of the Kaoko Belt. The Kalahari Craton units apparently did not constitute a main source area for the studied succession. This is possibly due to the position of the succession in the northern part of the Outjo Basin, at the southern margin of the Congo Craton. Comparison of the obtained geochronological data with those from the literature shows that the Abbabis High forms part of the Kalahari proto-craton and that Angola-Congo and Kalahari cratons were part of the same paleocontinent in Rodinia times.
DS201811-2604
2018
Schmitt, R.S.Richetti, P.C., Schmitt, R.S., Reeves, C.Dividing the South American continent to fit a Gondwana reconstruction: A model based on continental geology.Tectonophysics, Vol. 747-748, pp. 79-98.South Americaplate tectonics

Abstract: The South American continental plate has been affected by intraplate deformation since the start of West Gondwana disruption in the Lower Cretaceous (about 140?Ma). That the present shape of South America is not precisely the same as its shape in reassembled Gondwana partly explains the imperfect fits of the conjugate margins of the South Atlantic proposed since the first reconstruction models of the early 20th century. Several attempts at defining subplates within South America have been published but not all take account of existing knowledge of its continental geology. Here a subdivision into eight rigid subplates is proposed, based primarily on geological and tectonic evidence. Our model is tested against three published models of a multi-subplate Africa, as re-shaped to the pre-breakup outline of that continent, by visual fitting and the use of piercing points. The South America blocks were rotated and the Euler poles calculated interactively in reconstruction software. All three proposed fits had overlapping block margins within South America, indicating post-breakup rifting, except for the Transbrasiliano lineament. This NNE-SSW crustal-scale shear zone was used as a boundary for seven of the eight blocks. It is clearly the main intraplate accommodation zone in South America and an important piercing point in relation to the Kandi lineament in West Africa. The other block boundaries correspond to narrow zones with sedimentary basins and/or dyke swarms that have developed since South Atlantic opening. Each fit required a different configuration of the South America subplates since the pre-rift disposition of the African subplates also differ from each other, contributing to the uncertainty in any detailed reassembly.
DS201812-2873
2018
Schmitt, R.S.Richetti, P.C., Schmitt, R.S., Reeves, C.Dividing the South American continent to fit a Gondwana reconstruction: a model based on continental geology.Tectonophysics, Vol. 747-748, pp. 79-98.South Americatectonics

Abstract: The South American continental plate has been affected by intraplate deformation since the start of West Gondwana disruption in the Lower Cretaceous (about 140?Ma). That the present shape of South America is not precisely the same as its shape in reassembled Gondwana partly explains the imperfect fits of the conjugate margins of the South Atlantic proposed since the first reconstruction models of the early 20th century. Several attempts at defining subplates within South America have been published but not all take account of existing knowledge of its continental geology. Here a subdivision into eight rigid subplates is proposed, based primarily on geological and tectonic evidence. Our model is tested against three published models of a multi-subplate Africa, as re-shaped to the pre-breakup outline of that continent, by visual fitting and the use of piercing points. The South America blocks were rotated and the Euler poles calculated interactively in reconstruction software. All three proposed fits had overlapping block margins within South America, indicating post-breakup rifting, except for the Transbrasiliano lineament. This NNE-SSW crustal-scale shear zone was used as a boundary for seven of the eight blocks. It is clearly the main intraplate accommodation zone in South America and an important piercing point in relation to the Kandi lineament in West Africa. The other block boundaries correspond to narrow zones with sedimentary basins and/or dyke swarms that have developed since South Atlantic opening. Each fit required a different configuration of the South America subplates since the pre-rift disposition of the African subplates also differ from each other, contributing to the uncertainty in any detailed reassembly.
DS202103-0367
2021
Schmitt, R.S.Armistad, S.E., Collins, A.S., Schmitt, R.S., Costa, R.L., De Waele, B., Razakamanana, T., Payne, J.L., Foden, J.D.Proterozoic basin evolution and tectonic geography of Madagascar: implications for an East Africa connection during the Paleoproterozoic. ( zircon analyses link Tanzania craton and India)Tectonics, doi/epdf/10. 10292020Tc006498 Africa, Madagascarcraton

Abstract: Madagascar hosts several Paleoproterozoic sedimentary sequences that are key to unravelling the geodynamic evolution of past supercontinents on Earth. New detrital zircon U-Pb and Hf data, and a substantial new database of ?15,000 analyses are used here to compare and contrast sedimentary sequences in Madagascar, Africa and India. The Itremo Group in central Madagascar, the Sahantaha Group in northern Madagascar, the Maha Group in eastern Madagascar, and the Ambatolampy Group in central Madagascar have indistinguishable age and isotopic characteristics. These samples have maximum depositional ages > 1700 Ma, with major zircon age peaks at c. 2500 Ma, c. 2000 Ma and c. 1850 Ma. We name this the Greater Itremo Basin, which covered a vast area of Madagascar in the late Paleoproterozoic. These samples are also compared with those from the Tanzania and the Congo cratons of Africa, and the Dharwar Craton and Southern Granulite Terrane of India. We show that the Greater Itremo Basin and sedimentary sequences in the Tanzania Craton of Africa are correlatives. These also tentatively correlate with sedimentary protoliths in the Southern Granulite Terrane of India, which together formed a major intra?Nuna/Columbia sedimentary basin that we name the Itremo?Muva?Pandyan Basin. A new Paleoproterozoic plate tectonic configuration is proposed where central Madagascar is contiguous with the Tanzania Craton to the west and the Southern Granulite Terrane to the east. This model strongly supports an ancient Proterozoic origin for central Madagascar and a position adjacent to the Tanzania Craton of East Africa.
DS200512-0942
2005
Schmitt, R.T.Schmitt, R.T., Lapke, C., Lingemann, C.M., Siebenschock, M., Stoffler, D.Distribution and origin of impact diamonds in the Ries Carter, Germany.Geological Society of America, Special Paper, No. 384, pp. 299-314.Europe, GermanyMeteorite
DS1994-1546
1994
Schmitz, M.Schmitz, M.A balanced model of the southern Central AndesTectonics, Vol. 13, No. 2, April, pp. 484-492Argentina, Bolivia, AndesCrustal structure, Tectonics
DS1997-1004
1997
Schmitz, M.Schmitz, M., Heinsohn, W.D., Schilling, F.R.Seismic gravity and petrological evidence for partial melt beneath the thickened Central Andean crustTectonophysics, Vol. 270, No. 3-4, March 15, pp. 313-South America, Bolivia, Chile, Brazil, AndesGeophysics - seismic, Mantle melt
DS1997-1005
1997
Schmitz, M.Schmitz, M., Kley, J.The geometry of the central Andean back arc crust: joint interpretation of cross section balance and seismicJournal of South American Earth Sciences, Vol. 10, No. 1, pp. 99-Chile, BoliviaTectonics, Backarc
DS2001-1033
2001
Schmitz, M.Schmitz, M., Bowring, S.Constraints on southern African lithospheric thermal evolution from uranium-lead (U-Pb) rutile titanite thermochronologySlave-Kaapvaal Workshop, Sept. Ottawa, 3p. abstractSouth Africa, LesothoXenoliths - lower crustal, Deposit - Newlands
DS2002-1422
2002
Schmitz, M.Schmitz, M., Chalbaud, D., Castillo, J., Izarra, C.The crustal structure of the Guayana Shield, Venezuela, from seismic refraction and gravity data.Tectonophysics, Vol.345, 1-4, Feb.15, pp. 103-118.Venezuela, GuyanaGeophysics - seismics, gravity, Tectonics
DS200412-1824
2004
Schmitz, M.Silver, P.G., Fouch, M.J., Gao, S.S., Schmitz, M.Seismic anisotropy, mantle fabric, and the magmatic evolution of Precambrian southern Africa.South African Journal of Geology, Vol. 107, 1/2, pp. 45-58.Africa, South AfricaGeophysics - seismics, tectonics, magmatism
DS200512-0943
2005
Schmitz, M.Schmitz, M., Martins, A., Izarra, C., Jacome, M.I., Sanchez, J., Rocabado, V.The major features of the crustal structure in northeastern Venezuela from deep wide angle seismic observations and gravity modelling.Tectonophysics, Vol. 399, 1-4, April 27, pp. 109-124.South America, VenezuelaGeophysics - seismics, crustal structure, tectonics
DS200612-1301
2006
Schmitz, M.Silver, P.G., Behn, M., Kelley, K., Schmitz, M., Savage, B.Understanding cratonic flood basalts.Earth and Planetary Science Letters, in pressAfrica, South Africa, RussiaCraton, lithosphere, origin debate
DS201112-0652
2011
Schmitz, M.Masy, J., Niu, F., Levander, A., Schmitz, M.Mantle flow beneath northwestern Venezuela: seismic evidence for a deep origin of the Merida Andes.Earth and Planetary Science Letters, Vol. 305, 3-4, pp. 396-404.South America, VenezuelaGeophysics - seismics
DS201112-0653
2011
Schmitz, M.Masy, J., Niu, F., Levander, A., Schmitz, M.Mantle flow beneath northwestern Venezuela: seismic evidence for a deep orogin of the Merida Andes.Earth and Planetary Science Letters, In press, availableSouth America, VenezuelaGeophysics - seismics
DS201501-0019
2015
Schmitz, M.Masy, J., Niu, F., Levander, A., Schmitz, M.Lithospheric expression of cenozoic subduction, mesozoic rifting and the Precambrian shield in Venezuela.Earth and Planetary Science Letters, Vol. 410, pp. 12-24.South America, VenezuelaSubduction
DS202002-0205
2019
Schmitz, M.Mazuera, F., Schmitz, M., Escalona, A., Zelt, C., Levander, A.Lithospheric structure of northwestern Venezuela from wide angle seismic data: implications for the understanding of continental margin evolution.Journal of Geophysical Research: Solid Earth, Vol. 124, 12, pp. 13124-131249. ( open access)South America, Venezuelageophysics - seismic

Abstract: Northwestern Venezuela is located in the complex deformation zone between the Caribbean and South American plates. Several models regarding the lithospheric structure of the Mérida Andes have been proposed. Nevertheless, they lack relevant structural information in order to support the interpretation of deeper structures. Therefore, a 560?km?long refraction profile across the northern part of Mérida Andes, oriented in a NNW direction, covering areas from the Proterozoic basement in the south, to both Paleozoic and Meso?Cenozoic terranes of northwestern Venezuela to the north, is analyzed in this contribution. Thirteen land shots were recorded by 545 short?deployment seismometers, constraining P wave velocity models from first?arrival seismic tomography and layer?based inversion covering the whole crust in detail, with some hints to upper mantle structures. The most prominent features imaged are absence of a crustal root associated to the Mérida Andes, as the Northern Andes profile is located marginal to the Andean crustal domain, and low?angle subduction of the Caribbean oceanic slab (~10-20°) beneath northwestern South America. Further crustal structures identified in the profile are (a) crustal thinning beneath the Falcón Basin along the western extension of the Oca?Ancón fault system interpreted as a back?arc basin; (b) suture zones between both the Proterozoic and Paleozoic provinces (Ouachita?Marathon?related suture?), and Paleozoic and Meso?Cenozoic terranes (peri?Caribbean suture) interpreted from lateral changes in seismic velocity; and (c) evidence of a deep Paleozoic(?) extensional basin, underlying thick Mesozoic and Cenozoic sequences (beneath the Guárico area).
DS202103-0405
2021
Schmitz, M.Schmitz, M., Ramirez, K., Mazuera, F., Avila, J., Yegres, L., Bezada, M., Levander, A.Moho depth map of northern Venezuela on wide-angle seismic studies.Journal of South American Earth Sciences, Vol. 107, 103088, 17p. PdfSouth America, VenezuelaGeophysics - seismics

Abstract: As part of the lithosphere, the crust represents Earth's rigid outer layer. Some of the tools to study the crust and its thickness are wide-angle seismic studies. To date, a series of seismic studies have been carried out in Venezuela to determine in detail the crustal thickness in the southern Caribbean, in the region of the Caribbean Mountain System in northern Venezuela, as well as along the Mérida Andes and surrounding regions. In this study, a review of the wide-angle seismic data is given, incorporating new data from the GIAME project for western Venezuela, resulting in a map of Moho depth north of the Orinoco River, which serves as the basis for future integrated models. Differences in Moho depths from seismic data and receiver function analysis are discussed. From the Caribbean plate, Moho depth increases from 20 to 25 km in the Venezuela Basin to about 35 km along the coast (except for the Falcón area where a thinning to less than 30 km is observed) and 40-45 km in Barinas - Apure and Guárico Basins, and Guayana Shield, respectively. Values of more than 50 km are observed in the Maturín Basin and in the southern part of the Mérida Andes.
DS1998-1297
1998
Schmitz, M.D.Schmitz, M.D., Bowring, S.A., Robey, J.A.Constraining the thermal history of an Archean craton: uranium-lead (U-Pb)thermochronology of lower crustal xenoliths...7th. Kimberlite Conference abstract, pp. 766-8.South AfricaCraton - Kaapvaal, Geochronology, geothermometry
DS2000-0869
2000
Schmitz, M.D.Schmitz, M.D., Bowring, S.A.Constraints on the thermal evolution of the deep crust of the Kaapvaal Craton from uranium-lead (U-Pb) rutile xenoliths..Geological Society of America (GSA) Abstracts, Vol. 32, No. 7, p.A-164.South AfricaGeochronology - lower crustal, Craton - Kaapvaal
DS2001-1034
2001
Schmitz, M.D.Schmitz, M.D., Bowring, S.A.The significance of uranium-lead (U-Pb) zircon dates in lower crustal xenoliths from the southwestern margin of Kaapvaal...Chemical Geology, Vol. 172, No. 1-2, Feb. pp. 59-76.South Africa, southernGeochronology, Craton - Kaapvaal
DS2003-0095
2003
Schmitz, M.D.Bell, D.R., Schmitz, M.D., Janney, P.E.Mesozoic thermal evolution of the southern African mantle lithosphereLithos, Vol. 71, 2-4, pp. 273-87.South AfricaGeothermometry
DS2003-1230
2003
Schmitz, M.D.Schmitz, M.D., Bowring, S.A.Constraints on the thermal evolution of continental lithosphere from U Pb accessoryContributions to Mineralogy and Petrology, Vol. 144, pp. 592-618.South AfricaGeothermometry
DS2003-1231
2003
Schmitz, M.D.Schmitz, M.D., Shirey, S.B., Carlson, R.C.High pressure U Pb geochronology and Lu Hf isotopic systematics of zircons in8ikc, Www.venuewest.com/8ikc/program.htm, Session 2, POSTER abstractSouth AfricaEclogites and Diamonds
DS2003-1232
2003
Schmitz, M.D.Schmitz, M.D.,Bowring, S.A.Ultrahigh temperature metamorphism in the lower crust during NeoarcheanGeological Society of America Bulletin, Vol. 115, 5, May pp. 533-48.South AfricaMetamorphism, Craton
DS200412-0130
2003
Schmitz, M.D.Bell, D.R., Schmitz, M.D., Janney, P.E.Mesozoic thermal evolution of the southern African mantle lithosphere.Lithos, Vol. 71, 2-4, pp. 273-87.Africa, South AfricaGeothermometry
DS200412-1760
2003
Schmitz, M.D.Schmitz, M.D., Bowring, S.A.Ultrahigh temperature metamorphism in the lower crust during Neoarchean Ventersdorp rifting and magmatism, Kaapvaal Craton, soutGeological Society of America Bulletin, Vol. 115, 5, May pp. 533-48.Africa, South AfricaMetamorphism Craton
DS200412-1761
2004
Schmitz, M.D.Schmitz, M.D., Bowring, S.A., De Wit, M.J., Gartz, V.Subduction and terrane collision stabilize the western Kaapvaal Craton tectosphere 2.9 billion years ago.Earth and Planetary Science Letters, Vol. 222, 2, pp. 363-376.Africa, South AfricaSubduction, tectonics, continental lithosphere
DS200512-0944
2004
Schmitz, M.D.Schmitz, M.D.Zircons in cratonic mantle eclogites: insights into subcontinental lithospheric mantle evolution and metasomatism.Geological Society of America Annual Meeting ABSTRACTS, Nov. 7-10, Paper 17-3, Vol. 36, 5, p. 46.Africa, South AfricaGeodynamic evolution
DS200612-0290
2006
Schmitz, M.D.Crowley, J.L., Schmitz, M.D., Bowring, S.A., Williams, M.L., Karlstrom, K.E.U Pb Hf isotopic analysis of zircon in lower crustal xenoliths from the Navajo volcanic field: 1.4 Ga mafic magmatism and metamorphism beneath Colorado Plateau.Contributions to Mineralogy and Petrology, Vol. 151, 3, pp. 313-330.United States, Colorado PlateauGeochronology
DS201312-0171
2013
Schmitz, M.D.Condon, D.J., Schmitz, M.D.One hundred years of isotope geochronology, and counting.Elements, Vol. 9, pp. 15-17.TechnologyGeochronology - history
DS201312-0785
2013
Schmitz, M.D.Schmitz, M.D., Kuiper, K.F.High-precision geochronology.Elements, Vol. 9, pp. 25-30.TechnologyGeochronology - differences
DS201810-2360
2018
Schmitz, M.D.Nasdala, L., Corfu, F., Schoene, B., Tapster, S.R., Wall, C.J., Schmitz, M.D., Ovtcharova, M., Schaltegger, U., Kennedy, A.K., Kronz, A., Reiners, P.W., Yang, Y-H., Wu, F-Y., Gain, S.E.M., Griffin, W.L., Szymanowski, D., Chanmuang, C., Ende, N.M., ValleyGZ7 and GZ8 - two zircon reference materials for SIMS U-Pb geochronology.Geostandards and Geoanalytical Research, http://orchid.org/0000-0002-2701-4635 80p.Asia, Sri Lankageochronology

Abstract: Here we document a detailed characterization of two zircon gemstones, GZ7 and GZ8. Both stones had the same mass at 19.2 carats (3.84 g) each; both came from placer deposits in the Ratnapura district, Sri Lanka. The U-Pb data are in both cases concordant within the uncertainties of decay constants and yield weighted mean ²??Pb/²³?U ages (95% confidence uncertainty) of 530.26 Ma ± 0.05 Ma (GZ7) and 543.92 Ma ± 0.06 Ma (GZ8). Neither GZ7 nor GZ8 have been subjected to any gem enhancement by heating. Structure?related parameters correspond well with the calculated alpha doses of 1.48 × 10¹? g?¹ (GZ7) and 2.53 × 10¹? g?¹ (GZ8), respectively, and the (U-Th)/He ages of 438 Ma ± 3 Ma (2s) for GZ7 and 426 Ma ± 9 Ma (2s) for GZ8 are typical of unheated zircon from Sri Lanka. The mean U concentrations are 680 ?g g?¹ (GZ7) and 1305 ?g g?¹ (GZ8). The two zircon samples are proposed as reference materials for SIMS (secondary ion mass spectrometry) U-Pb geochronology. In addition, GZ7 (Ti concentration 25.08 ?g g?¹ ± 0.18 ?g g?¹; 95% confidence uncertainty) may prove useful as reference material for Ti?in?zircon temperature estimates.
DS201811-2562
2018
Schmitz, M.D.Craddock, J., Malone, D., Schmitz, M.D., Gifford, J.N.Strain variations across the Proterozoic Penokean Orogen, USA and Canada. Sudbury impact Precambrian Research, Vol. 318, pp. 25-69.United States, Canadaorogeny

Abstract: Strata in the Huron (2.5-2.0 Ga) and Animikie (2.2-1.85 Ga) basins were deposited on the southern margin of the Archean Superior province. These rocks were deformed during the Penokean orogeny (?1850 Ma) followed by subsequent accretionary orogens to the south at 1750 Ma (Yavapai) and 1630 Ma (Mazatzal). Strain patterns are unique to each orogenic belt with no far-field effect: Archean Wawa terrane rocks in the Penokean foreland preserve deformation associated with Archean accretion with no younger Penokean, Yavapai or Mazatzal strain overprint. The Penokean orogeny deformed Huron-Animikie basin sediments into a north-vergent fold-and-thrust belt with no Yavapai or Mazatzal strain overprint. Yavapai orogen strains (SW-NE margin-parallel shortening) are unique when compared to the younger Mazatzal shortening (N20°W) shortening, with no strain overprint. Penokean deformation is characterized by shortening from the south including uplifted Archean gneisses and a northerly thin-skinned fold-and-thrust belt, with north-vergent nappes and a gently-dipping foreland. Our study of finite and calcite twinning strains (n=60) along (?1500 km) and across (?200 km) the Penokean belt indicate that this orogeny was collisional as layer-parallel shortening axes are parallel across the belt, or parallel to the tectonic transport direction (?N-S). Penokean nappe burial near the margin resulted in vertical shortening strain overprints, some of which are layer-normal. The Sudbury impact layer (1850 Ma) is found across the Animikie basin and provides a widespread deformation marker with many local, unique strain observations. We also report new geochronology (U-Pb zircon and apatite) for the gneiss-mafic dike rocks at Wissota (Chippewa Falls, WI) and Arbutus (Black River Falls, WI) dams, respectively, which bears on Penokean-Yavapai deformation in the Archean Marshfield terrane which was accreted during the Penokean orogen. Pseudotachylite formation was common in the Superior province Archean basement rocks, especially along terrane boundaries reactivated by contemporaneous Penokean, Trans-Hudson, Cape Smith and New Quebec deformation. In the hinterland (south), the younger Yavapai orogen (1750 Ma; n=8) deformation is preserved as margin-parallel horizontal shortening (?SW-NE) in Yavapai crust and up to 200 km to the north in the Penokean thrust belt as a strain and Barrovian metamorphic overprint. Mazatzal deformation (1630 Ma; n=16) is preserved in quartzites on Yavapai and Penokean crust with layer-parallel and layer-normal shortening strains oriented N20°W.
DS201112-0961
2011
Schmitz, S.Silversmit, G., Vekemans, B., Appel, K., Schmitz, S., Schoonjans, T., Brenker, F.E., Kaminsky, F., Vincze, L.Three dimensional Fe speciation of an inclusion cloud within an ultradeep diamond by confocal u-x-ray absortion near edge structure: evidence for late stageAnalytical Chemistry, Vol. 83, pp. 6294-6299.South America, Brazil, Mato GrossoJuina, Rio Soriso, diamond overprint
DS201412-0668
2014
Schmitz, S.Pearson, D.G., Brenker, F., Nestola, F., McNeil, J., Nasdala, L., Hutchison, M., Mateev, S., Mather, K., Silversmit, G., Schmitz, S., Vekemans, B., Vinczw=e, L.A hydrous mantle transition zone indicated by ring woodite included within diamond.Goldschmidt Conference 2014, 1p. AbstractMantleDiamond inclusion
DS201412-0669
2014
Schmitz, S.Pearson, D.G., Brenker, F.E., Nestola, F., McNeill, J., Nasdala, L., Hutchinson, M.T., Mateev, S., Mather, K., Silversmit, G., Schmitz, S., Vekemans, B., Vincze, L.Hydrous mantle transition zone indicated by ring woodite included in diamond.Nature, Vol. 507, March 13, pp. 221-224.Mantle, South America, Brazil, Mato GrossoDiamond inclusion - water storage capacity, magmatism
DS201610-1860
2016
Schmuck, H.R.Forster, M.W., Prelevic, D., Schmuck, H.R., Jacob, D.E.Melting and dynamic metasomatism of mixed harzburgite + glimmerite mantle source: implications for the genesis of orogenic potassic magmas.Chemical Geology, in press available 10p.MantleUltrapotassic magmas

Abstract: Tectonically young, orogenic settings are commonly the sites of post-collisional silica-rich ultrapotassic magmas with extreme K2O-contents of up to 9 wt% and K2O/Na2O > 2. Many experimental studies investigating the generation of these melts have concentrated on melting of homogenous phlogopite bearing peridotites, whereas geochemical signatures indicate the involvement of at least two types of source rocks: ultra-depleted and K and trace elements-enriched ones. We report the results of melting experiments at 1-2 GPa of mixed glimmerite and harzburgite, in which these rock types make up two halves each capsule. Melting begins in the glimmerite, and its metasomatic effects on the harzburgite are apparent at 1100 °C even before melt pools are visible. The first melts are Na-rich, seen in zoning of olivines and as growth of clinopyroxene in the harzburgite, but change at higher degrees of melting to produce a typical lamproite-like melt with K2O > 10 wt%. A major advantage of this study is the preservation of distinct melts in different parts of the capsule, which reflect a process of dynamic metasomatism: within the harzburgite matrix, the infiltrating melt derived from melting of the glimmerite changes consistently with the distance of travel through the harzburgite, enabling quantification of the metasomatic effects as an increase in SiO2 and K2O. This results principally from assimilation of orthopyroxene, which increases the Ol/Opx ratio of the residual harzburgite. The effects of quench olivine growth are recognizable and can be quantified due to a step-change in composition at the glimmerite/harzburgite border: the large total surface area of olivine and small melt fraction mean that the amount of quench olivine is high within the harzburgite, but negligible in the almost completely molten glimmerite. Melts of the glimmerite contain up to 8-10 wt% K2O and 53 wt% SiO2, which increase to 55-56 wt% after interaction with the harzburgite. Mediterranean lamproites resemble melts of glimmerite, whereas melts that have interacted with harzburgite are more similar to less potassic, but more SiO2-rich shoshonites of the Mediterranean region.
DS201707-1323
2017
Schmuck, H.R.Forster, M.W., Orelevic, D., Schmuck, H.R., Buhre, S., Veter, M., Mertz-Kraus, R., Foley, S.F., Jacob, D.E.Melting and dynamic metasomatism of mixed harzburgite + glimmerite mantle source: implications for the genesis of orogenic potassic magmas.Chemical Geology, Vol. 455, pp. 182-191.Mantlemetasomatism

Abstract: Tectonically young, orogenic settings are commonly the sites of post-collisional silica-rich ultrapotassic magmas with extreme K2O-contents of up to 9 wt% and K2O/Na2O > 2. Many experimental studies investigating the generation of these melts have concentrated on melting of homogenous phlogopite bearing peridotites, whereas geochemical signatures indicate the involvement of at least two types of source rocks: ultra-depleted and K and trace elements-enriched ones. We report the results of melting experiments at 1–2 GPa of mixed glimmerite and harzburgite, in which these rock types make up two halves each capsule. Melting begins in the glimmerite, and its metasomatic effects on the harzburgite are apparent at 1100 °C even before melt pools are visible. The first melts are Na-rich, seen in zoning of olivines and as growth of clinopyroxene in the harzburgite, but change at higher degrees of melting to produce a typical lamproite-like melt with K2O > 10 wt%. A major advantage of this study is the preservation of distinct melts in different parts of the capsule, which reflect a process of dynamic metasomatism: within the harzburgite matrix, the infiltrating melt derived from melting of the glimmerite changes consistently with the distance of travel through the harzburgite, enabling quantification of the metasomatic effects as an increase in SiO2 and K2O. This results principally from assimilation of orthopyroxene, which increases the Ol/Opx ratio of the residual harzburgite. The effects of quench olivine growth are recognizable and can be quantified due to a step-change in composition at the glimmerite/harzburgite border: the large total surface area of olivine and small melt fraction mean that the amount of quench olivine is high within the harzburgite, but negligible in the almost completely molten glimmerite. Melts of the glimmerite contain up to 8–10 wt% K2O and 53 wt% SiO2, which increase to 55–56 wt% after interaction with the harzburgite. Mediterranean lamproites resemble melts of glimmerite, whereas melts that have interacted with harzburgite are more similar to less potassic, but more SiO2-rich shoshonites of the Mediterranean region.
DS201804-0689
2018
Schmuck, H.R.Forster, M.W., Prelevic, D., Schmuck, H.R., Buhre, S., Marschall, H.R., Mertz-Kraus, R., Jacob, D.E.Melting phologopite rich MARID: lamproites and the role of alkalis in olivine liquid Ni partioning.Chemical Geology, Vol. 476, 1, pp. 429-440.Technologylamproites

Abstract: In this study, we show how veined lithospheric mantle is involved in the genesis of ultrapotassic magmatism in cratonic settings. We conducted high pressure experiments to simulate vein + wall rock melting within the Earth's lithospheric mantle by reacting assemblages of harzburgite and phlogopite-rich hydrous mantle xenoliths. These comprised a mica-, amphibole-, rutile-, ilmenite-, diopside (MARID) assemblage at 3-5 GPa and 1325-1450 °C. Melting of the MARID assemblages results in infiltration of melt through the harzburgite, leading to its chemical alteration. At 3 and 4 GPa, melts are high in K2O (> 9 wt%) with K2O/Na2O > > 2 comparable to anorogenic lamproites. Higher pressures and temperatures (5 GPa/1450 °C) lead to increasing MgO contents of the melt and to some extent lower K2O contents (5-7 wt%) at equally high K2O/Na2O ratios. Our experiments provide insights into the role of alkalis in nickel-partitioning (DNi) between olivine and ultrapotassic melt. We observe that the high contents of Na, K, and Al are indicative of high DNi values, implying that the melt polymerization is the dominant factor influencing the olivine/melt nickel partitioning. The change of DNi as a function of melt composition results in a pressure independent, empirical geothermometer: Element oxides represent the composition of the glass (in wt%), and DNi is the liquid/olivine Ni-partitioning coefficient. We propose that this geothermometer is applicable to all natural silicate melts that crystallized olivine in a temperature interval between 1000 and 1600 °C. Application to glass-olivine pairs from calc-alkaline settings (Mexico), MORB (East Pacific Rise), and OIB (Hawaii) yielded reasonable values of 996-1199 °C, 1265 °C, and 1330 °C, respectively.
DS1960-0494
1964
Schmucker, U.Schmucker, U.Anomalies of Geomagnetic Variations in the Southwestern United States.Journal of GEOMAGN. GEOELECTRIC (KYOTO), Vol. 15, PP. 193-221.GlobalGeophysics, Mid-continent
DS201112-0876
2011
Schnbohm, D.Rohrbach, A., Ballhaus, C., Ulmer, P., Golla-Schindler, U., Schnbohm, D.Experimental evidence for a reduced metal saturated upper mantle.Journal of Petrology, Vol. 52, 4, pp. 717-737.MantleRedox
DS1995-1674
1995
Schneer, C.J.Schneer, C.J.Origin of mineralogy: the age of AgricolaEuropean Journal of Mineralogy, No. 4, pp. 721-734GlobalMineralogy, History
DS1984-0634
1984
Schneider, A.Schneider, A.Alteration of Lherzolite Minerals During Reaction with Basaltic Melts.Referate Der Vortrage Und Poster Auf Der 62 Jahrestagung Der, Vol. 62, No. 1, P. 217. (abstract., ).GlobalBlank
DS1986-0709
1986
Schneider, A.Schneider, A.Interaction of metasomatic fluids and basaltic melt with mantle xenolithsProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 320-322GermanyBlank
DS201605-0896
2016
Schneider, A.Schneider, A.Komatiites reveal a deep, hydrous mantle reservoir 2.7 Ga ago.Nature, Mar. 31, 1p.Canada, QuebecWater - hydrous mantle

Abstract: For decades, geologists have debated the geodynamic processes that operated in the young Earth. In the Archean, 4 and 2.5 billion years ago, the interior of the planet was much hotter which led to more rapid convection and, according to some authors, to an absence of plate tectonics. Komatiites (Fig. 1) - volcanic rocks with abnormal, olivine-enriched compositions - are thought to result from high-degrees of partial melting of extremely hot parts of the Earth’s mantle. This interpretation is blurred, however, by uncertainty as to the water content of komatiitic magmas. There are two schools of thought on this question: the first proposes that the magmas were dry (<0.1% water) and very hot (> 1600°C), and were produced in mantle plumes from the base of the mantle; the second suggests that the magmas were hydrated, with lower melting temperatures, and had formed in subduction settings. The analysed komatiite melt contained 30% magnesium oxide and 0.6% water and began to crystallize at a relatively low temperature of 1530°C. The chemical composition of the magma and low oxygen fugacity are inconsistent with a subduction setting. he mantle plume (orange) traverses the transition zone, which contains excess H2O, F and Cl in ringwoodite and/or wadsleyite (high pressure polymorphs of olivine).The plume is hot enough to be partially molten near the top of the transition zone (small black dots) and entrains hydrous melt (blue shapes) either from the layer at the upper boundary of the transition zone or from the hot boundary between the plume and the transition zone. Alternatively or additionally, the plume may entrain solid wadsleyite from the transition zone (green shapes). All these hydrous materials introduce H2O and possibly F and Cl into the plume and accelerate its melting (larger black dots). Further ascent of the plume generates more melt during decompression (large black dots), which then separates from the source and ascends to the surface without reaction with peridotite (purple stripes). Instead, the authors suggest that the magmas were generated in a deep mantle plume and that the water and other volatile components, especially the halogens (F, Cl), were entrained into the komatiitic magma as it passed through the transition zone between the upper and lower mantle, at a depth below 410 km (Fig. 3). This implies the existence of a deep reservoir of water in the mantle: a portion of the mantle containing a few thausends of parts per million of water in high pressure polymorphs of olivine wadsleyite, ringwoodite. This water may have accumulated during the primordial accretion of the Earth or by the unexpectedly early subduction of hydrated slabs that became trapped in the transition zone. Finally, the authors propose that modern mantle plumes do not extract water from the transition zone because they are colder and therefore entirely solid when they crossed the transition zone.
DS2001-0829
2001
Schneider, C.L.Neumann, R., Schneider, C.L.Prediction of monazite liberation from the silexitic rare earth ore of Catalao iMinerals Engineering, Vol. 14, No. 12, Dec. pp. 1601-7.BrazilCarbonatite, Deposit - Catalao
DS1998-0636
1998
Schneider, D.Holm, D., Schneider, D., Coath, C.D.Age and deformation of Early Proterozoic quartzites in the southern Lake superior region: implications for ..Geology, Vol. 26, No. 10, Oct. pp. 907-10Wisconsin, MichiganTectonics, Laurentia Mazatzal orogeny
DS2002-0733
2002
Schneider, D.Holm, D., Schneider, D.40 Ar 39 Ar evidence for ca 1800 Ma tectonothermal activity along the Great Falls tectonic zone, central Montana.Canadian Journal of Earth Sciences, Vol. 39, 12, Dec. pp. 1719-28.MontanaGeochronology
DS2002-0734
2002
Schneider, D.Holm, D.J., Schneider, D.40 Ar 39 Ar evidence for ca 1800 Ma tectonothermal activity along the Great Falls tectonic zone, central Montana.Canadian Journal of Earth Sciences, Vol. 39, 12, pp. 1719-28.MontanaTectonics, Geothermometry, geochronology
DS201112-1059
2011
Schneider, D.Tschegg, C., Bizimis, M., Schneider, D., Akinin, V.V., Ntaflos, T.Magmatism at the Eurasian North American modern plate boundary: constraints from alkaline volcanism in the Chersky belt (Yakutia).Lithos, Vol. 125, pp. 825-835.Russia, YakutiaAlkaline rocks, volcanism, mantle melting
DS201312-0107
2013
Schneider, D.Buckley, S.J., Kurz, T.H., Howell, J.A., Schneider, D.Terrestrial lidar and hyper spectral dat a fusion products for geological outcrop analysis. NOT specific to diamonds ( shale and carbonates)Computers & Geosciences, Vol. 54, pp. 249-258.United States, Europe, SpainLidar - interest
DS202004-0522
2020
Schneider, D.Kellett, D.A., Pehrsson, S., Skipton, D., Regis, D., Camacho, A., Schneider, D., Berman, R.Thermochronological history of the Northern Canadian Shield. Nuna, Churchill Province, Trans-Hudson orogen, Thelon, RaePrecambrian Research, doi.org/10.1016/j.precamres.2020.105703 in press available 80p. PdfCanadageothermometry

Abstract: The northern Canadian Shield is comprised of multiple Archean cratons that were sutured by the late Paleoproterozoic to form the Canadian component of supercontinent Nuna. More than 2000 combined K-Ar and 40Ar/39Ar cooling ages from across the region reveal a stark contrast in upper and lower plate thermal responses to Nuna-forming events, with the Churchill Province in particular revealing near complete thermal reworking during the late Paleoproterozoic. We review the detailed cooling history for five regions that span the Churchill Province and Trans-Hudson orogen (THO): Thelon Tectonic Zone, South Rae, Reindeer Zone, South Hall Peninsula, and the Cape Smith Belt. The cooling patterns across Churchill Province are revealed in two >1500 km transects. At the plate scale, Churchill’s cooling history is dominated by THO accretionary and collisional events, during which it formed the upper plate. Cooling ages generally young from west to east across both southern and central Churchill, and latest cooling in the THO is 50 myr older in southernmost Churchill (Reindeer Zone) compared to eastern Churchill (Hall Peninsula), indicating diachronous thermal equilibration across 2000 km strike length of the THO. Churchill exhibits relatively high post-terminal THO cooling rates of ~4 °C/myr, which support other geological evidence for widespread rapid exhumation of the THO upper plate following terminal collision, potentially in response to lithospheric delamination.
DS200712-0955
2007
Schneider, D.A.Schneider, D.A., Heizler, M.T., Bickford, M.E., Wortman, G.L., Condie, K.C., Perilli, S.Timing constraints of orogeny to cratonization: thermochronology of the Paleoproterozoic Trans-Hudson orogen, Manitoba and Saskatchewan, Canada.Precambrian Research, Vol. 153, 1-2, pp. 65-95.Canada, Manitoba, SaskatchewanGeothermometry
DS201707-1368
2017
Schneider, D.A.Skipton, D.R., Schneider, D.A., Kellett, D.A., Joyce, N.L.Deciphering the Paleoproterozoic cooling history of the northeastern Trans-Hudson Orogen, Baffin Island ( Canada), using 40Ar/39Ar step heating and UV laser thermochrobology.Lithos, Vol. 284-285. pp. 69-90.Canada, Nunavut, Baffin Islandgeothermometry

Abstract: The previously unstudied cooling and exhumation history of mid-crustal rocks exposed on southeastern Baffin Island (Canada) provides new insights into the post-orogenic evolution of the Paleoproterozoic Trans-Hudson Orogen (THO). New 40Ar/39Ar step-heat analyses of biotite, muscovite and phlogopite and core-to-rim intra-grain 40Ar/39Ar analyses of muscovite have a range of apparent ages compatible with slow regional cooling following peak metamorphism. Twenty-nine amphibolite- to granulite-facies rocks were dated using the 40Ar/39Ar step-heating laser (CO2) method. 40Ar/39Ar spot analyses were performed across muscovite grains from three samples using an ultraviolet (UV) laser to investigate intra-grain 40Ar/39Ar age variations. Step-heating apparent ages range from ca. 1788–1622 Ma for biotite, 1720–1630 Ma for phlogopite and 1729–1657 Ma for muscovite. UV spot 40Ar/39Ar analyses in the three muscovite grains range from ca. 1661–1640 Ma, 1675–1645 Ma and 1680–1652 Ma, with core-to-rim apparent age gradients of 20–30 Myr. Previous studies resolved peak metamorphism in this region to between ca. 1860 and 1820 Ma and identified late- to post-THO zircon and monazite populations at ca. 1800–1750 Ma. Numerical diffusion models for Ar in muscovite were conducted to test different Proterozoic cooling and exhumation scenarios. Comparisons with our 40Ar/39Ar ages attest to cooling rates of ~ 1–2 °C/Myr following peak metamorphism and ~ 1.5–2.5 °C/Myr after ca. 1740 Ma. Anomalously old apparent 40Ar/39Ar ages, in cases equivalent to U–Pb zircon rim and monazite ages, likely result from incorporation of excess Ar. The results suggest that mid-crustal rocks on southeastern Baffin Island remained hotter than ~ 420–450 °C for ~ 150–200 Myr after peak metamorphism, with subsequent slow cooling and denudation rates that are typical of Proterozoic orogens. The apparent absence of orogenic collapse implies that, despite high temperatures and estimated maximum crustal thicknesses comparable to those of large, hot orogens, the THO remained gravitationally stable during its terminal phase.
DS201805-0962
2018
Schneider, D.A.McDannell, K.T., Zeitler, P.K., Schneider, D.A.Instability of the southern Canadian Shield during the late Proterozoic.Earth Planetary Science Letters, Vol. 490, pp. 100-109.Canadacraton

Abstract: Cratons are generally considered to comprise lithosphere that has remained tectonically quiescent for billions of years. Direct evidence for stability is mainly founded in the Phanerozoic sedimentary record and low-temperature thermochronology, but for extensive parts of Canada, earlier stability has been inferred due to the lack of an extensive rock record in both time and space. We used 40Ar/39Ar multi-diffusion domain (MDD) analysis of K-feldspar to constrain cratonic thermal histories across an intermediate (~150-350°C) temperature range in an attempt to link published high-temperature geochronology that resolves the timing of orogenesis and metamorphism with lower-temperature data suited for upper-crustal burial and unroofing histories. This work is focused on understanding the transition from Archean-Paleoproterozoic crustal growth to later intervals of stability, and how uninterrupted that record is throughout Earth’s Proterozoic "Middle Age." Intermediate-temperature thermal histories of cratonic rocks at well-constrained localities within the southern Canadian Shield of North America challenge the stability worldview because our data indicate that these rocks were at elevated temperatures in the Proterozoic. Feldspars from granitic rocks collected at the surface cooled at rates of <0.5°C/Ma subsequent to orogenesis, seemingly characteristic of cratonic lithosphere, but modeled thermal histories suggest that at ca. 1.1-1.0 Ga these rocks were still near ~200°C - signaling either reheating, or prolonged residence at mid-crustal depths assuming a normal cratonic geothermal gradient. After 1.0 Ga, the regions we sampled then underwent further cooling such that they were at or near the surface (<< 60°C) in the early Paleozoic. Explaining mid-crustal residence at 1.0 Ga is challenging. A widespread, prolonged reheating history via burial is not supported by stratigraphic information, however assuming a purely monotonic cooling history requires at the very least 5 km of exhumation beginning at ca. 1.0 Ga. A possible explanation may be found in evidence of magmatic underplating that thickened the crust, driving uplift and erosion. The timing of this underplating coincides with Mid-Continent extension, Grenville orogenesis, and assembly of the supercontinent Rodinia. 40Ar/39Ar MDD data demonstrate that this technique can be successfully applied to older rocks and fill in a large observational gap. These data also raise questions about the evolution of cratons during the Proterozoic and the nature of cratonic stability across deep time.
DS201810-2354
2018
Schneider, D.A.McDannell, K.T., Zeitler, P.K., Schneider, D.A.Instability of the southern Canadian shield during the Late Proterozoic.researchgate.com, 29p. PdfCanadacraton

Abstract: Cratons are generally considered to comprise lithosphere that has remained tectonically quiescent for billions of years. Direct evidence for stability is mainly founded in the Phanerozoic sedimentary record and low-temperature thermochronology, but for extensive parts of Canada, earlier stability has been inferred due to the lack of an extensive rock record in both time and space. We used 40Ar/39Ar multi-diffusion domain (MDD) analysis of K-feldspar to constrain cratonic thermal histories across an intermediate (?150-350?°C) temperature range in an attempt to link published high-temperature geochronology that resolves the timing of orogenesis and metamorphism with lower-temperature data suited for upper-crustal burial and unroofing histories. This work is focused on understanding the transition from Archean-Paleoproterozoic crustal growth to later intervals of stability, and how uninterrupted that record is throughout Earth's Proterozoic “Middle Age.” Intermediate-temperature thermal histories of cratonic rocks at well-constrained localities within the southern Canadian Shield of North America challenge the stability worldview because our data indicate that these rocks were at elevated temperatures in the Proterozoic. Feldspars from granitic rocks collected at the surface cooled at rates of <0.5?°C/Ma subsequent to orogenesis, seemingly characteristic of cratonic lithosphere, but modeled thermal histories suggest that at ca. 1.1-1.0 Ga these rocks were still near ?200?°C - signaling either reheating, or prolonged residence at mid-crustal depths assuming a normal cratonic geothermal gradient. After 1.0 Ga, the regions we sampled then underwent further cooling such that they were at or near the surface (?60?°C) in the early Paleozoic. Explaining mid-crustal residence at 1.0 Ga is challenging. A widespread, prolonged reheating history via burial is not supported by stratigraphic information, however assuming a purely monotonic cooling history requires at the very least 5 km of exhumation beginning at ca. 1.0 Ga. A possible explanation may be found in evidence of magmatic underplating that thickened the crust, driving uplift and erosion. The timing of this underplating coincides with Mid-Continent extension, Grenville orogenesis, and assembly of the supercontinent Rodinia. 40Ar/39Ar MDD data demonstrate that this technique can be successfully applied to older rocks and fill in a large observational gap. These data also raise questions about the evolution of cratons during the Proterozoic and the nature of cratonic stability across deep time.
DS202106-0956
2021
Schneider, D.J.Mason, E, Wieser, P.E., Liu, E.J., Edmonds, M., Ilyinskaya, E., Whitty, R.C., Mather, T.A., Elias, T., Nadeau, P.A., Wilkes, T.C., McGonigle, A.J.S., Pering, T.D., Mims, F.M., Kern, C., Schneider, D.J., Oppenheimer, C.Volatile metal emissions from volcanic gassing and lava-seawater interactions at Kilauea volcano, Hawaii.Earth & Environment Communications, 10.1038/s43247-021-00145-3 16p. PdfUnited States, Hawaiimagmatism

Abstract: Volcanoes represent one of the largest natural sources of metals to the Earth’s surface. Emissions of these metals can have important impacts on the biosphere as pollutants or nutrients. Here we use ground- and drone-based direct measurements to compare the gas and particulate chemistry of the magmatic and lava-seawater interaction (laze) plumes from the 2018 eruption of K?lauea, Hawai’i. We find that the magmatic plume contains abundant volatile metals and metalloids whereas the laze plume is further enriched in copper and seawater components, like chlorine, with volatile metals also elevated above seawater concentrations. Speciation modelling of magmatic gas mixtures highlights the importance of the S2? ligand in highly volatile metal/metalloid degassing at the magmatic vent. In contrast, volatile metal enrichments in the laze plume can be explained by affinity for chloride complexation during late-stage degassing of distal lavas, which is potentially facilitated by the HCl gas formed as seawater boils.
DS2002-1423
2002
Schneider, G.Schneider, G.The Sperrgebeit land use plan - an example of integrated management of natural reosurces.11th. Quadrennial Iagod Symposium And Geocongress 2002 Held Windhoek, Abstract p. 40.NamibiaEnvironment
DS200512-0945
2004
Schneider, G.Schneider, G.The roadside geology of Namibia.Gebruder borntraeger-cramer.de, 294p. Euro 38. isnm 3-443-15080-2Africa, NamibiaBook - geology, mineralogy, attractions
DS1992-1342
1992
Schneider, G.I.C.Schneider, G.I.C., Miller, R.McG.Diamonds.... history, mining areas, individual depositsThe Mineral Resources of Namibia -diamonds, 32p.NamibiaOverview, Diamond deposits, geology, production
DS1994-0697
1994
Schneider, G.I.C.Hagni, R.D., Kogut, A.I., Schneider, G.I.C.Geology of the Okorusu carbonatite related fluorite deposit north centralNamibia.Geological Society of America Abstracts, Vol. 26, No. 5, April p. 18. Abstract.NamibiaCarbonatite
DS1995-0719
1995
Schneider, G.I.C.Hagni, R.D., Kogut, A.I., Schneider, G.I.C.The fluorite deposits of the Okorusu alkaline igneous and carbonatitecomplex, north central Namibia.Geological Society Africa 10th. Conference Oct. Nairobi, p. 129-30. Abstract.NamibiaAlkaline rocks, carbonatite, Deposit -Okorusu
DS1997-0464
1997
Schneider, G.I.C.Hagni, R.D., Kogut, A.I., Schneider, G.I.C.Mineralogical flurospar deposits at Okorusu north central NamibiaGeological Association of Canada (GAC) Abstracts, POSTER.NamibiaCarbonatite, Flurospar
DS2002-0218
2002
Schneider, J.Buhn, B., Rankin, A.H., Schneider, J., Dulski, P.The nature of orthomagmatic, carbonatitic fluids precipitating REE Sr rich flourite, fluid inclusion...Chemical Geology, Vol.186,1-2, pp. 75-98., Vol.186,1-2, pp. 75-98.NamibiaGeochronology - fluorite, Deposit - Okorusu
DS2002-0219
2002
Schneider, J.Buhn, B., Rankin, A.H., Schneider, J., Dulski, P.The nature of orthomagmatic, carbonatitic fluids precipitating REE Sr rich flourite, fluid inclusion...Chemical Geology, Vol.186,1-2, pp. 75-98., Vol.186,1-2, pp. 75-98.NamibiaGeochronology - fluorite, Deposit - Okorusu
DS200612-1242
2006
Schneider, J.Schneider, J., Jahn, B-M., Okamoto, K., Tong, L., Lizuka, Y., Xu, Z.Rb Sr and Sm Nd isotope analyses of CCSD eclogites ( Sulu, China): a test for the closure temperature concept.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 12, abstract only.ChinaUHP, geochronology
DS1997-1032
1997
Schneider, J.M.Sheehan, A.F., Jones, C.H., Schneider, J.M.Contrasting lithospheric structure beneath the Colorado Plateau and GreatBasin: initial results from PASSCAL.Geophysical Res. Letters, Vol. 24, No. 21, Nov. 1, pp. 2609-12.Colorado PlateauGeophysics - seismics PASSCAL, Mantle
DS2001-0655
2001
Schneider, J.M.Lastowika, L.A., Sheehan, A.F., Schneider, J.M.Seismic evidence for partial lithospheric delamination model of Colorado Plateau Uplift.Geophysical Research Letters, Vol. 28, No. 7, April 1, pp.1319-22.Colorado PlateauTectonics, Geophysics - seismics
DS1984-0635
1984
Schneider, M.E.Schneider, M.E., Eggler, D.H.Compositions of Fluids in Equilibrium with Peridotite: Implications for Alkaline Magmatism-metasomatismProceedings of Third International Kimberlite Conference, Vol. 1, PP. 383-394.GlobalMineral Chemistry, Analyses, Fluids
DS1986-0710
1986
Schneider, M.E.Schneider, M.E., Eggler, D.E.Fluids in equilibrium with peridotite minerals: implications for mantleMetasomatismGeochimica et Cosmochimica Acta, Vol. 50, pp. 711-724GlobalMantle, Metasomatism
DS1986-0711
1986
Schneider, M.E.Schneider, M.E., Eggler, D.H.Fluids in equilibrium with peridotite minerals-implications for mantleMetasomatismGeochem. et Cosmochem. Acta, Vol. 50, No. 5, May pp. 711-724GlobalMantle, Inclusions
DS1860-1007
1897
 
 

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