Kaiser Bottom Fish OnlineFree trialNew StuffHow It WorksContact UsTerms of UseHome
Specializing in Canadian Stocks
SearchAdvanced Search
Welcome Guest User   (more...)
Home / Education
Education
 

SDLRC - Scientific Articles all years by Author - Si-Sm


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.
Searching this page for a specific term or authorIn your Firefox browser click Edit in the menu bar and then Find. In the Find box that shows up at the bottom of the web page enter your search term. Firefox will highlight all occurrences. This is particularly helpful when the author you are seeking was not the lead author by whom the compilation is sorted.
Sending or sharing a referenceThe left column (Posted/Published) has an embedded hyperlink for each reference. In Firefox, if you right click on it, you can obtain the link url for that reference's location within the page, which you can copy and paste into an email or any other document. You can also use the "share this link" option to tweet, facebook etc the link.
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 - Si-Sm
Posted/
Published
AuthorTitleSourceRegionKeywords
DS2001-1075
2001
SI Diamond TechnologySI Diamond TechnologySucceeded to produce silicon namocrystals that exhibit bright fluorescent radiation in the visible range.Si Diamond Technology, Nov. 2, 2p.GlobalNews item - press release
DS2000-0743
2000
SialPandit, M.K., Sial, Golani, FerreiraTerrigenous and mantle contributions in Newania carbonatite body, stable isotopic constraints...Igc 30th. Brasil, Aug. abstract only 1p.India, WestCarbonatite - petrogenesis, Deposit - Newania
DS1987-0679
1987
Sial, A.N.Sial, A.N.The Tertiary alkaline province of Foraleza State of Ceara Brasil: oxygen isotopes and rare earth elements (REE)-geochemistry.Geochim. Bras., Vol. 1, No.1, pp. 41-51.BrazilAlkaline rocks, Geochronology
DS1990-0476
1990
Sial, A.N.Fodor, R.V., Sial, A.N., Mukasas, S.B., McKee, E.H.Petrology, isotope characteristics and K-Ar ages of the Maranhao northernBrasil, Mesozoic basalt provinceContributions to Mineralogy and Petrology, Vol. 104, No. 5, pp. 555-567BrazilGeochronology, Basalt
DS1991-0494
1991
Sial, A.N.Fodor, R.V., Gandhok, G.R., Sial, A.N.Vertical sampling of mantle beneath northeastern Brasil as represented by ultramafic xenoliths and megacrysis in Tertiary basaltsProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 101-102BrazilXenoliths, Mantle peridotite
DS1991-1579
1991
Sial, A.N.Sial, A.N., Fodor, R.V., Long, L.E.Mantle xenoliths of northeast BrasilFifth International Kimberlite Conferences Field Excursion Guidebook, Servico Geologico do Brasil (CPRM) Special, pp. 3-16BrazilMantle, Xenoliths
DS1994-0512
1994
Sial, A.N.Ferreira, V.P., Sial, A.N., Cruz, M.J.M.Mantle derived mica-pyroxenite inclusions in late Proterozoic ultrapotassic syenite magmas, northeast Brasil.International Symposium Upper Mantle, Aug. 14-19, 1994, Extended abstracts pp. 3-4.BrazilAlkaline rocks
DS1997-0347
1997
Sial, A.N.Ferreira, V.P., Sial, A.N., Pin, C.Isotopic signatures of Neoproterozoic to Cambrian ultrapotassic syeniticmagmas: evidence enriched mantleInternational Geology Review, Vol. 39, No. 7, July, pp. 660-Brazil, northeastAlkaline rocks, Mantle
DS1998-0436
1998
Sial, A.N.Fodor, R.V., Mukasa, S.B., Sial, A.N.Isotopic and trace element indications of lithospheric and asthenospheric components Tertiary alkalic basaltsLithos, Vol. 43, No. 4, Sept. 1, pp. 197-218BrazilAlkaline rocks, Geochronology
DS2000-0742
2000
Sial, A.N.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
DS2002-0466
2002
Sial, A.N.Fodor, R.V., Sial, A.N., Gandhok, G.Petrology of spinel peridotite xenoliths from northeastern Brasil: lithosphere with a high geothermal gradient imparted by Fernando de Nornha plume.Journal of South American Earth Sciences, Vol.15,2,June pp. 183-98.BrazilGeothermometry, Hot spots
DS2002-0467
2002
Sial, A.N.Fodor, R.V., Sial, A.N., Gandhok, G.Petrology of spinel peridotite xenoliths from northeastern Brasil: lithosphere with a high geothermal gradient imparted by Fernando de Noronha plume.Journal of South American Earth Sciences, Vol. 15, No. 2, pp. 199-214.BrazilTectonics, Xenoliths
DS2002-0468
2002
Sial, A.N.Fodor, R.V., Sial, A.N., Gandhok, G.Petrology of spinel peridotite xenoliths from northeastern Brasil: lithosphere with a high geothermal gradient imparted by Fernando de Noronha plume.Journal of South American Earth Sciences, Vol.15,2,June pp. 199-214.Brazil, northeastMagmatism, hot spots, Geothermometry
DS2002-0984
2002
Sial, A.N.Maheshwari, A., Sial, A.N., Chittora, V.K., Bhu, H.A positive d13C carb anomaly in Paleoproterozoic carbonates of the Aravalli Craton, western India: support for a global isotopic excursion.Journal of Asian Earth Sciences, Vol. 21, 1, pp. 59-67.IndiaGeochronology
DS2002-1209
2002
Sial, A.N.Pandit, M.K., Sial, A.N., Sukumaran, G.B., Pimentel, M.M., Ramasamy, A.K.Depleted and enriched mantle sources for Paleo- and Neoproterozoic carbonatites ofChemical Geology, Vol. 189,1-2,pp. 69-89.India, Tamil NaduCarbonatite - geochronology, Deposit - Samalpatti, Sevattur, Mulakkasu
DS201612-2325
2016
Sial, A.N.Pandit, M.K., Kumar, N., Sial, A.N., Sukumaran, G.B., Piementle, M., Ferreira, V.P.Geochemistry and C-O and Nd-Sr isotope characteristics of the 2.4 Ga Hogenakkal carbonatites and the South Indian granulite terrain: evidence for an end Archean depleted component and mantle heterogeneity.International Geology Review, Vol. 58, 12, pp. 1461-1480.IndiaCarbonatite

Abstract: The South Indian Granulite Terrane (SGT) is a collage of Archaean to Neoproterozoic age granulite facies blocks that are sutured by an anastomosing network of large-scale shear systems. Besides several Neoproterozoic carbonatite complexes emplaced within the Archaean granulites, there are also smaller Paleoproterozoic (2.4 Ga, Hogenakkal) carbonatite intrusions within two NE-trending pyroxenite dikes. The Hogenakkal carbonatites, further discriminated into sövite and silicate sövite, have high Sr and Ba contents and extreme light rare earth element (LREE) enrichment with steep slopes typical of carbonatites. The C- and O-isotopic ratios [d13CVPDB = -6.7 to -5.8‰ and d18OVSMOW = 7.5-8.7‰ except a single 18O-enriched sample (d18O = 20.0‰)] represent unmodified mantle compositions. The eNd values indicate two groupings for the Hogenakkal carbonatites; most samples show positive eNd values, close to CHUR (eNd = -0.35 to 2.94) and named high-eNd group while the low-eNd group samples show negative values (-5.69 to -8.86), corresponding to depleted and enriched source components, respectively. The 87Sr/86Sri ratios of the two groups also can be distinguished: the high-eNd ones have low 87Sr/86Sri ratios (0.70161-0.70244) while the low-eNd group shows higher ratios (0.70247-0.70319). We consider the Nd-Sr ratios as primary and infer derivation from a heterogeneous mantle source. The emplacement of the Hogenakkal carbonatites may be related to Paleoproterozoic plume induced large-scale rifting and fracturing related to initiation of break-up of the Neoarchean supercontinent Kenorland.
DS201907-1566
2016
Sial, S.Pandit, K., Sial, S., Piementle, F.Geochemistry and C-O and Nd-Sr isotope characteristics of thre 2.4 Ga Higenakkal carbonatites from the South Indian granulite terrane: evidence for an end- Archean depleted component and mantle heterogenity. Note date 2016International Geology Review, Vol. 58, 12, pp. 1461-1480.Indiacarbonatites

Abstract: The South Indian Granulite Terrane (SGT) is a collage of Archaean to Neoproterozoic age granulite facies blocks that are sutured by an anastomosing network of large-scale shear systems. Besides several Neoproterozoic carbonatite complexes emplaced within the Archaean granulites, there are also smaller Paleoproterozoic (2.4 Ga, Hogenakkal) carbonatite intrusions within two NE-trending pyroxenite dikes. The Hogenakkal carbonatites, further discriminated into sövite and silicate sövite, have high Sr and Ba contents and extreme light rare earth element (LREE) enrichment with steep slopes typical of carbonatites. The C- and O-isotopic ratios [d13CVPDB = -6.7 to -5.8‰ and d18OVSMOW = 7.5-8.7‰ except a single 18O-enriched sample (d18O = 20.0‰)] represent unmodified mantle compositions. The eNd values indicate two groupings for the Hogenakkal carbonatites; most samples show positive eNd values, close to CHUR (eNd = -0.35 to 2.94) and named high-eNd group while the low-eNd group samples show negative values (-5.69 to -8.86), corresponding to depleted and enriched source components, respectively. The 87Sr/86Sri ratios of the two groups also can be distinguished: the high-eNd ones have low 87Sr/86Sri ratios (0.70161-0.70244) while the low-eNd group shows higher ratios (0.70247-0.70319). We consider the Nd-Sr ratios as primary and infer derivation from a heterogeneous mantle source. The emplacement of the Hogenakkal carbonatites may be related to Paleoproterozoic plume induced large-scale rifting and fracturing related to initiation of break-up of the Neoarchean supercontinent Kenorland.
DS200612-1257
2006
Siame, L.Sebrier, M., Siame, L., Zouine, E.M., Winter, T., Missenard, Y., Leturmy, P.Active tectonics in the Moroccan High Atlas.Comptes Rendus Geoscience, Vol. 338, 1-2, pp. 65-79.Africa, MoroccoTectonics
DS1999-0334
1999
Siamiasang, T.L.Jarvis, W., McGeorge, I.B., Siamiasang, T.L.The mineral potential of BotswanaProspectors and Developers Association of Canada (PDAC) abstract volume, p. 8.BotswanaOverview
DS1995-1744
1995
Siamisang, T.L.Siamisang, T.L.Kimberlites in BotswanaGeological Society Africa 10th. Conference Oct. Nairobi, p. 63-4. AbstractBotswanaKimberlites, Brief overview
DS1988-0636
1988
Sibbett, B.S.Sibbett, B.S.Size, depth and related structures of intrusions under strata-volcanoes and associated geothermal systemsEarth Science Reviews, Vol. 25, pp. 291-309. Database # 17369OregonBreccia pipes, Volcanoes
DS1995-0161
1995
Sibbick, S.J.Bobrowksy, P.T., Sibbick, S.J., Newell, J.N., Matysek, P.Drift exploration in the Canadian CordilleraBritish Columbia Ministry of Energy and Mines, Paper 1995-2, 304p. $ 40.00British ColumbiaGeochemistry, Drift exploration- review
DS1995-0162
1995
Sibbick, S.J.Bobrowsky, P.T., Sibbick, S.J., Newell, J.M., Matysek, P.F.Drift exploration in the Canadian CordilleraBritish Columbia Energy Mines Resources, Paper, 1995-2, 290p.British Columbia, YukonGeomorphology, Drift prospecting - applicable to gold
DS1986-0004
1986
Sibertsev, Y.M.Afanasyev, V.P., Sibertsev, Y.M., Yegorov, A.Y.Minerals from kimberlites in ancient littoral reservoir rocks. (Russian)Izv. Vysshikh Uchn. Zaved. Geol. I Razveda (Russian), Vol. 2, pp. 48-54RussiaPetrology, Mineral chemistry
DS1960-0497
1964
Sibirtsev, YU. M.Sibirtsev, YU. M.New Information on the Age of Kimberlites in the Northeastern Siberian Platform (kuoyka River Basin).Doklady Academy of Science USSR, Earth Science Section., Vol. 148, PP. 127-128.RussiaBlank
DS1988-0773
1988
Sibirtsev, Yu.M.Yemelyanov, V.N., Sibirtsev, Yu.M.Applying magnetic surveys to the exploration of buried ancientreservoirs.(Russian)Razv. I Okhr. Nedr. (Russian), No. 10, pp. 57-59RussiaYakutia, Geophysics
DS1960-0397
1963
Sibirtzev, YU. M.Sibirtzev, YU. M., Prokopchuk, B.I.New Dat a on the Age of the Kimberlites of the Northeastern Part of the Siberian Platform (kuoyko Ri Basin).French Geological Survey (BRGM) TRANSLATION., RussiaBlank
DS200912-0220
2009
Sibley, S.J.Fisher, D., Sibley, S.J., Kelly, C.J.Brown colour in natural diamond and interaction between the brown related and other colour inducing defects.Journal of Physics Condensed Matter, in press ( August)TechnologyBrown diamonds
DS201508-0359
2015
Sibley, S.J.Howell, D., Fisher, D., Piazolo, S., Griffin, W.L., Sibley, S.J.Pink color in Type I diamonds: is deformation twinning the cause?American Mineralogist, Vol. 100, pp. 1518-1527.Australia, South America, VenezuelaDeposit - Argyle, Santa Elena
DS1995-0793
1995
Sibson, R.Hickman, S., Sibson, R., Bruhn, R.Introduction to special section: mechanical involvement of fluids infaultingJournal of Geophysical Research, Vol. 100, No.B7, July 10, pp. 12, 831-840GlobalStructure, Fluids -faulting
DS1991-1580
1991
Sibson, R.H.Sibson, R.H.Conditions for fault valve behaviourDeformation Mechanisms, Rheology and Tectonics, editors Knipe, R.J., No. 54, pp. 15-28GlobalStructure -faults, Fault valves
DS1992-1400
1992
Sibson, R.H.Sibson, R.H.Fault valve behaviour and the hydrostatic-lithostatic fluid pressureinterfaceEarth Science Reviews, Vol. 32, pp. 141-144. Extended abstractGlobalStructure, Fault valve behavior
DS1996-1305
1996
Sibson, R.H.Sibson, R.H.Structural permeability of fluid driven fault fracture meshesJournal of Structural Geology, Vol. 18, No. 8, Aug. 1, pp. 1031-150GlobalStructure, Fluid flow regime
DS200712-0144
2007
SichelCarlson, R.W., Aruajo, Junqueira-Brod, Gaspar, Brod, Petrinovic, Hollanda, Pimentel, SichelChemical and isotopic relationships between peridotite xenoliths and mafic-ultrapotassic rocks from southern Brazil.Chemical Geology, Vol. 242, 3-4, pp. 418-437.South America, BrazilGeochemistry
DS200712-0145
2007
SichelCarlson, R.W., Aruajo, Junqueira-Brod, Gaspar, Brod, Petrinovic, Hollanda, Pimentel, SichelChemical and isotopic relationships between peridotite xenoliths and mafic-ultrapotassic rocks from southern Brazil.Chemical Geology, Vol. 242, 3-4, pp. 418-437.South America, BrazilGeochemistry
DS1970-0599
1972
Sichel, H.S.Sichel, H.S.Statistical Valuation of Diamondiferous DepositsInternational SYMPOSIUM ON THE APPLICATION of COMPUTER METHODS IN, PP. 17-25.South AfricaSampling, Evaluation, Mining, Diamond
DS1995-1745
1995
Sichel, H.S.Sichel, H.S., Dohm, C.E., Kleingeld, W.J.New generalized model of observed ore value distributionsInstitute of Mining and Metallurgy (IMM) Bulletin, Sect. A May-Aug, pp. A115-123GlobalGeostatistics, Ore reserves
DS1995-1746
1995
Sichel, H.S.Sichel, H.S., Dohm, C.E., Kleingeld, W.J.New generalized model of observed ore value distributionsTransactions of the Institute of Mining and Metallurgy (IMM)., Vol. 104, No. A, pp. A115-A123.South AfricaGeostatistics, Diamonds mentioned
DS201608-1419
2016
Sichel, S.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.
DS1994-1596
1994
Sichel, S.E.Sichel, S.E.SiO2 -MgO tholeiites and picrites: two primary melt compositions along The south Atlantic ridge.International Symposium Upper Mantle, Aug. 14-19, 1994, Extended abstracts pp. 33-35.OceanPicrites
DS2003-0444
2003
Sichel, S.E.Gaspar, J.C., Araujo, A.L.N., Carlson, R.W., Sichel, S.E., Brod, J.A., SgarbiMantle xenoliths and new constraints on the origin of alkaline ultrapotassic rocks from8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, POSTER abstractBrazilBlank
DS200412-0612
2003
Sichel, S.E.Gaspar, J.C., Araujo, A.L.N., Carlson, R.W., Sichel, S.E., Brod, J.A., Sgarbi, P.B., Danni, J.C.M.Mantle xenoliths and new constraints on the origin of alkaline ultrapotassic rocks from the Alto Paranaiba and Goias igneous pro8 IKC Program, Session 7, POSTER abstractSouth America, BrazilKimberlite petrogenesis
DS200612-1256
2006
Sicilia, D.Sebai, A., Stutzmann, E., Montagner, J-P., Sicilia, D., Beucler, E.Anistropic structure of the African upper mantle from Rayleigh and Love wave tomography.Physics of the Earth and Planetary Interiors, Vol. 155, 1-2, pp. 48-62.Mantle, AfricaGeodynamics, cratons, West Africa, Congo, Kalahari
DS200812-0761
2007
Sicilia, D.Montagner, J.P., Marty, B., Stutzmann, E., Sicilia, D., Cara, M., Pik, R., Leveque, Roult, Beucier, DeBayleMantle upwellings and convective instabilities revealed by seismic tomography and helium isotope geochemistry beneath eastern Africa.Geophysical Research Letters, Vol. 34, 21, Nov. 16, ppp. L21303.AfricaConvection
DS201806-1252
2018
Sicola, S.Sicola, S., Vona, A., Romano, C., Ryan, A.G., Russell, J.K.In-situ high-temperature rheology of pore-bearing magmas. ( obsidian )Geophysical Research , Vol. 20, EGU2018-13349 1p. AbstractIcelandmagmatism

Abstract: Porous rocks represent the products of all explosive volcanic eruptions. As magma ascends to the Earth’s surface, bubbles form as a consequence of the evolving saturation state of volatiles dissolved in the melt. The presence of pores (either filled with pressurized volatiles or not) strongly controls the rheological behaviour of magma and thus influences all volcanic processes (pre- syn- and post-eruptive). Nevertheless, the effects of porosity on the rheology of magma are not well characterised, and a general parameterization is not available yet. Here we present a new set of experiments designed to investigate the rheology of porous melts at high temperature (750-800 C), low strain rates (10^6-10^7 s^-1) and variable porosity. Experiments were performed at 1 atm using a Setaram Setsys vertical dilatometer. The starting materials are 5 x 5 mm cores of natural rhyolitic obsidian from Hrafntinnuhryggur, Krafla, Iceland (vesicle and crystal-free) initially containing 0.11(4) wt% dissolved H2O. The experimental procedure is composed by two steps: 1) synthesis of bubble-bearing materials by heating and expansion due to foaming; 2) deformation of the foamed samples. During the first step, the obsidian cores are heated above the glass transition temperature to 900- 1050 C and held for set amounts of time (2-24 h); the volume of the foamed samples increases because H2O vapour-filled bubbles nucleate and expand. The change in volume (measured by He-pycnometry) is linked to the change in porosity (10-50 vol%). For the second step, two different experimental strategies are employed, hereafter “single-stage” and “doublestage” measurements. Single-stage measurements involve deformation of the samples directly after foaming (without quenching). The sample is cooled down from the foaming T to different target T (750-800 C), a constant load (150 g) is applied by silica or alumina probes to the core, and the cores deform isothermally for 5-20 hours. Conversely, double-stage measurements involve deformation of previously synthesised and quenched pore-bearing cores. In this case the sample is heated up to the target T and deformed under an applied load for similar amount of time (5-20 hours). In both cases, the variation in length (displacement) and volume (porosity) is continuously recorded and used to calculate the viscosity of the foamed cores using Gent’s equations. Preliminary results suggest for single-stage measurements a lower effect of bubbles on the bulk viscosity, compared to double-stage measurements. We suggest that the different behaviour may be related to the different microstructure of the experimental materials. For single-stage measurements, closed and H2O vapour-filled bubbles contribute to the observed higher viscosity, whereas in double-stage measurements, possible gas leaking and melt micro-cracking during quenching are able to weaken the porous material and markedly lower suspension viscosity.
DS200612-0564
2005
Sidao, Ni.Helmberger, D.V., Sidao, Ni.Seismic modeling constraints on the South African super plume.American Geophysical Union, Geophysical Monograph, ed. Van der Hilst, Earth's Deep mantle, structure ...., No. 160, pp. 63-82.Africa, South AfricaGeophysics - seismics
DS200612-1244
2006
Sidaty, H.Schofield, D.J., HOrstwood, M.S.A., Pitfield, P.E.J., Crowley, Q.G., Wilkinson, A.F., Sidaty, H.,Ch,O.Timing and kinematics of Eburnean tectonics in the central Reguibat Shield, Mauritania.Journal of the Geological Society, Vol. 163, 3, pp. 549-560.Africa, MauritaniaTectonics - not specific to diamonds
DS201812-2879
2018
Sidder, A.Sidder, A.How nitrogen contributes to permafrost carbon dynamics.EOS, doi.org/10.1029/2018EO107611 Nov. 2 United States, Alaskacarbon

Abstract: The Arctic is warming 2-3 times faster than the global average. The rapid increase of near-surface air temperatures at high latitudes is driving a loss of ice in oceans, rivers, mountain glaciers, and soil. Permafrost, the perennially frozen ground found in frigid climates, is estimated to store approximately 1,500 gigatons of carbon, or about half of the world’s underground stores. This carbon is slowly escaping from the soil as permafrost thaws; this thawing could release as much carbon into the atmosphere as current emissions from global land use change over the next 80 years. Like many other models of future conditions, uncertainty plagues the estimates of permafrost carbon release. Salmon et al. explored how nitrogen, an important contributor to this uncertainty, interacts with carbon in thawing soils. Nitrogen is an essential nutrient for plants and soil microbes but occurs in limited supply in tundra soils. This limitation restricts plant growth and microbial decomposition, which are critical pieces of the carbon cycle. The researchers drilled soil cores at the Eight Mile Lake site in interior Alaska to depths of 85 centimeters to evaluate the annually thawed active layer (0-55 centimeters) as well as the upper permafrost (below 55 centimeters). They then incubated the soil cores at 15°C for about 8 months and measured the subsequent nitrogen levels and microbial biomass. The data collected in the incubation informed statistical models that were used to analyze the effects of depth, time, and growing season conditions on nitrogen and carbon dynamics. The findings revealed that both carbon loss and microbial biomass decreased significantly with soil depth. Models predicted that soil decomposition would release the largest amount of mineral nitrogen from soils located in the middle of the active layer. Permafrost soils at the bottom of the soil profile, however, released a large flush of mineral nitrogen during the initial thaw but a small flux of mineral nitrogen during subsequent decomposition. These patterns indicate that microbes near the soil surface are nitrogen limited, whereas deep microbial communities are more limited by carbon. The team’s calculations estimate that mineral nitrogen released from the soil profile would increase tenfold during the first 5 years of permafrost thaw. Should permafrost continue to thaw in the Arctic, these results suggest that tundra ecosystems may experience an increase in nitrogen availability that exceeds plant and microbial demands. Excess nitrogen, in turn, could precipitate increased decomposition of soil carbon and increased levels of nitrogen in streams draining from thawing permafrost landscapes. The study offers critical insights into how warming temperatures in the Arctic could dramatically increase permafrost thaw and initiate profound changes in carbon and nitrogen cycling in tundra ecosystems.
DS1989-1388
1989
Sidder, G.B.Sidder, G.B.A revised bibliography of the geology and mineral deposits of the Guyana shield in Venezuela, Guyana,Suriname and BrasilUnited States Geological Survey (USGS) Open File, Preprint No. 89- 58pGlobalDiamonds
DS1990-1358
1990
Sidder, G.B.Sidder, G.B.Geologic province map of the Venezuelan Guiana shieldUnited States Geological Survey (USGS) Open File Report, No. 90-73, 14p. P. 7 Roraima GroupVenezuelaDiamonds mentioned, Geology
DS1990-1359
1990
Sidder, G.B.Sidder, G.B.Mineral occurrences of the Guiana shield, VenezuelaUnited States Geological Survey (USGS) Open File Report, No. 90-16, 28pVenezuelaDiamonds pp. 5-6, Occurrences
DS1990-1360
1990
Sidder, G.B.Sidder, G.B.Geologic province map of the Venezuela Guiana ShieldUnited States Geological Survey (USGS) Open File, No. 90-73, 14pVenezuelaGuiana shield, Geology map
DS1990-1361
1990
Sidder, G.B.Sidder, G.B.Mineral occurrences of the Guiana shield, Venezuela - mapUnited States Geological Survey (USGS) Open File, No. 90-16, 28p. 1 mapVenezuelaMineral deposits, Guiana shield
DS1990-1362
1990
Sidder, G.B.Sidder, G.B., Martinez, F.Geology, geochemistry and mineral resources of the upper Caura River at Bolivar State, VenezuelaUnited States Geological Survey (USGS) Open File, No. 90-0231, 29p. $ 5.00VenezuelaGeochemistry, General, Mineral resources
DS1991-1581
1991
Sidder, G.B.Sidder, G.B., Mendoza, V.Geology of the Venezuelan Guyanan shield and its relation to the entire Guyana shieldUnited States Geological Survey (USGS) Open File, No. 91-0141, 59p. 2 maps $ 13.00Venezuela, GuyanaGeology, Guyana shield
DS1991-1582
1991
Sidder, G.B.Sidder, G.B., Nuelle, L.M., Day, W.C., Rye, R.O., Seeger, C.M.Paragenesis and conditions of formation of the Pea Ridge iron and rareearth element deposit, MissouriGeological Society of America Annual Meeting Abstract Volume, Vol. 23, No. 5, San Diego, p. A 292MissouriRare earths, Midcontinent
DS1991-1898
1991
Sidder, G.B.Wynn, J.C., Sidder, G.B.Mineral resource potential of the NB -20-4 Quadrangle eastern GuayanaShield, Bolivar State, VenezuelaUnited States Geological Survey (USGS) Bulletin, No. B 1960, 16p. $ 3.50VenezuelaMineral potential
DS1992-1401
1992
Sidder, G.B.Sidder, G.B., Day, W.C., Nuelle, L.M., Seeger, C.M., KisvarsanyiMineralogic and fluid inclusion studies of the Pea Ridge iron-rare earth-element deposit, southeast MissouriUnited States Geological Survey (USGS) Bulletin, No. 2039, pp. 205-216MissouriRare earths, Olympic Dam type mineralization study
DS1993-1463
1993
Sidder, G.B.Sidder, G.B., Day, W.C.iron-copper-rare earth elements (REE) deposits in Middle Proterozoic rocks of the Midcontinent region of the United States..are they Olympic Dam-type deposits?The Gangue, Geological Association of Canada (GAC)/Mineral Deposits Newsletter, No. 42, April pp. 1-4MissouriCopper, rare earths, Deposit -Olympic Dam type
DS1995-1747
1995
Sidder, G.B.Sidder, G.B.Mineral deposits of the Venezuelan Guayana ShieldU.s. Geological Survey Bulletin., No. 2124-A, Chapter OVenezuela, GuyanaMineral deposits, Diamonds
DS1995-2086
1995
Sidder, G.B.Wynn, J.C., Sidder, G.B., Gray, F., Page, N.J., Mendoza, V.Geology and mineral deposits of the Venezuelan Guayana shield... goldUnited States Geological Survey (USGS) Bulletin, No. 2124-A, approx. 150pVenezuela, GuyanaBook -table of contents, Geophysics, Lo Increible, Sierra Verdun, Cerro ArrendaJ.
DS201212-0578
2012
Siddiqui, M.A.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
DS1960-0095
1960
Siddle, S.F.Siddle, S.F.The African Diamond IndustryUnknown, South AfricaProduction
DS201112-0119
2011
Siddoway, C.S.Brown, M., Korhonen, F.J., Siddoway, C.S.Organizing melt flow through the crust.Elements, Vol. 7, 4, August pp. 261-266.MantleDykes, ductile fracturing, migmatites
DS202006-0919
2020
Siddoway, C.S.Flowers, R.M., Macdonald, F.A., Siddoway, C.S., Havranek, R.Diachronous development of Great Unconformities before Neoproterozoic Snowlball Earth. Proceedinds of the National Academy of Sciences, Vol. 117, 19, 9p. PdfUnited States, Coloradogeothermometry

Abstract: The Great Unconformity marks a major gap in the continental geological record, separating Precambrian basement from Phanerozoic sedimentary rocks. However, the timing, magnitude, spatial heterogeneity, and causes of the erosional event(s) and/or depositional hiatus that lead to its development are unknown. We present field relationships from the 1.07-Ga Pikes Peak batholith in Colorado that constrain the position of Cryogenian and Cambrian paleosurfaces below the Great Unconformity. Tavakaiv sandstone injectites with an age of =676 ± 26 Ma cut Pikes Peak granite. Injection of quartzose sediment in bulbous bodies indicates near-surface conditions during emplacement. Fractured, weathered wall rock around Tavakaiv bodies and intensely altered basement fragments within unweathered injectites imply still earlier regolith development. These observations provide evidence that the granite was exhumed and resided at the surface prior to sand injection, likely before the 717-Ma Sturtian glaciation for the climate appropriate for regolith formation over an extensive region of the paleolandscape. The 510-Ma Sawatch sandstone directly overlies Tavakaiv-injected Pikes granite and drapes over core stones in Pikes regolith, consistent with limited erosion between 717 and 510 Ma. Zircon (U-Th)/He dates for basement below the Great Unconformity are 975 to 46 Ma and are consistent with exhumation by 717 Ma. Our results provide evidence that most erosion below the Great Unconformity in Colorado occurred before the first Neoproterozoic Snowball Earth and therefore cannot be a product of glacial erosion. We propose that multiple Great Unconformities developed diachronously and represent regional tectonic features rather than a synchronous global phenomenon.
DS1991-0804
1991
Sides, A.Johnson, M.S., Sides, A.Environmental assessment of new mining projects- code of practice for appointment and management of environmental consultantsInstitute of Mining and Metallurgy (IMM) Minerals Industry International, September pp. 13-18GlobalEconomics, Law-environmental
DS1992-1402
1992
Sides, E.J.Sides, E.J.Reconciliation studies and reserve estimationGeological Society Special Publication, Case histories and methods in, No. 63, pp. 197-218GlobalComputer, Ore reserves, geostatistics
DS1997-1041
1997
Sides, E.J.Sides, E.J.Geological modeling of mineral deposits for prediction in miningGeologische Rundschau, Vol. 86, No. 2, pp. 342-353GlobalEconomics, discoveries, Deposit model
DS201012-0708
2010
Sides, E.J.Sides, E.J.A time value framework for reporting mineral assets.Canadian Institute of Mining and Metallurgy, Vol. 1, no. 1, pp. 34-43.GlobalMineral resource valuation - not specific to diamonds
DS1981-0377
1981
Sides, J.R.Sides, J.R., Bickford, M.E., Shuster, R.D.Calderas in the Precambrian St. Francois Mountains Terrane, southeastern Missouri.Journal of GEOPHYSICAL RESEARCH, Vol. 86, No. B11, PP. 10349-10364.GlobalMid-continent
DS201412-0112
2014
Sidhu, R.Chakhmouradian, A.R., Reguir, E.P., Kressal, R.D., Crozier, J., Pisiak, L.K., Sidhu, R., Yang, P.Carbonatite hosted niobium deposit at Aley, northern British Columbia ( Canada): mineralogy, geochemistry and petrogenesis.Ore Geology Reviews, Vol. 64, pp. 642-666.Canada, British ColumbiaCarbonatite
DS201502-0081
2015
Sidhu, R.Moore, M., Chakhmouradian, A.R., Mariano, A.N., Sidhu, R.Evolution of rare-earth mineralzation in the Bear Lodge carbonatite, Wyoming: mineralogical and isotopic evidence.Ore Geology Reviews, Vol. 64, pp. 499-521.United States, Wyoming, Colorado PlateauDeposit - Bear Lodge
DS201802-0251
2017
Sidkina, E.S.Malov, A.I., Sidkina, E.S., Ryzhenko, B.N.Model of the Lomonosov diamond deposit as a water rock system: migration species, groundwater saturation with rock forming and ore minerals, and ecological assessment of water quality.Geochemistry International, Vol. 55, 12, pp. 1118-1130.Russiadeposit - Lomonosov

Abstract: Thermodynamic numerical simulations were carried out to determine the principal simple and complex migration species of Ca, Mg, Na, K, Al, B, Mn, Mo, Sr, and U with Cl-, OH-, SO4-2, HCO3-, and CO32- in waters at the Lomonosov diamond deposit and to estimate the saturation indexes with respect to kaolinite, Na- and Mg-montmorillonite, Mg- and Na-saponite, muscovite and paragonite, biotite, phlogopite, chromite, pyrite, plagioclase (anorthite, labradorite, and andesine), olivine (forsterite and fayalite), diopside, pyrope, gypsum, anhydrite, barite, magnesite, calcite, dolomite, talc, chrysotile, chlorite, goethite, quartz, microcline, and albite. The waters are proved not to be saturated with respect to the primary (hydrothermal) minerals. The saturation of certain water samples with uranophane suggests that this mineral is of secondary genesis. The ascent of highly mineralized deep waters shall result in the dissolution of minerals whose concentrations are near the saturation ones. To maintain the ecological standards of the discharged waters, they should be diluted and/or purified by adsorbing dissolved U on a reducing reactive barrier.
DS1980-0309
1980
Sidorenko, A.V.Sidorenko, A.V.International Mineral AssociationLeningrad: Nauka., RussiaPrecious Stones, Diamonds
DS1990-0241
1990
Sidorenko, G.A.Brodin, B.V., Shulgin, A.S., Dubinchuk, V.T., Sidorenko, G.A.The mineralogy of low temperature hydrothermal molybdenum depositsInternational Geology Review, Vol. 32, No. 11, November pp. 1156-1165RussiaMolybdenuM., Mineralogy
DS1997-1079
1997
Sidorenko, G.A.Sokolov, S.V., Sidorenko, G.A.Manganese rich monticellite from the Oka carbonatites, QuebecGeochemistry International, Vol. 35, No. 9, Sept. pp. 810-815.QuebecCarbonatite, Deposit - Oka
DS2001-1099
2001
Sidorenko, G.A.Sokjolov, S.V., Sidorenko, G.A., Chukanov, ChistyakovaOn benstonite and benstonite carbonatiteGeochemistry International, Vol. 39, No. 12, Dec. pp.Russia, IndiaCarbonatite, Deposit - Murun, Aldan, Jogipatti
DS1998-1345
1998
Sidorin, I.Sidorin, I., Gurnis, M., Helmberger, D.V., Ding, X.Interpreting D seismic structure using synthetic waveforms computed from dynamic models.Earth and Planetary Science Letters, Vol. 163, No. 1-4, Nov. pp. 31-41.MantleGeophysics - seismic, Slab
DS1999-0666
1999
Sidorin, I.Sidorin, I., Gurnis, M., Hlemberger, D.V.Dynamics of a phase change at the base of the mantle consistent with seimological observations.Journal of Geophysical Research, Vol. 104, No. 7, July 10, pp. 15005-22.MantleGeophysics - seismics
DS1994-1597
1994
Sidorov, A.A.Sidorov, A.A., Eremin, R.A.Metallogeny of the Russian northeastern Region and Alaska: a comparativestudyGeol. of Pacific Ocean, Vol. 11, No. 2, pp. 179-188Russia, AlaskaMetallogeny, Gold, tin, lead zinc Kuroko MS copper
DS200712-0290
2006
Sidorov, V.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
DS200412-0513
2004
Sidorov, V.A.Ekimov, E.A., Sidorov, V.A., Bauer, E.D., Melnik, N.N., Curro, N.J., Thompson,J.D., Stishov, S.M.Superconductivity in diamond.Nature, No. 6982,April 1, pp. 542-44.TechnologyDiamond - morphology
DS200412-0514
2004
Sidorov, V.A.Ekimov, E.A., Sidorov, V.A., Melnik, N.N., Gierlotka, S., Presz, A.Synthesis of polycrystalline diamond in the boron carbide graphite and boron graphite systems under high pressure and temperaturJournal of Materials Research, Vol. 39, 15, pp. 4957-4960.TechnologyDiamond synthesis
DS201811-2569
2018
Sidorov, V.A.Ekimov, E.A., Sidorov, V.A., Maslakov, K.I., Sirotinkin, B.P., Krotova, M.D., Pleskov, Yu.V.Influence of growth medium composition on the incorporation of boron in HPHT diamond.Diamond & Related Materials, Vol. 89, pp. 101-107.Mantleboron

Abstract: Influence of growth medium composition on the efficiency of boron doping of carbonado-like diamond at 8-9 GPa was studied by diluting the C-B growth system with metallic solvents of carbon, Co and Ni. Addition of these metals to the original system leads to a decrease in the synthesis temperature, degree of doping with boron and suppression of superconductivity in diamond. According to XPS analysis, content of substitutional boron is equal to 0.07, 0.16 and 0.39 at.% in diamonds obtained in Co-C-B, Ni-C-B and C-B growth systems, respectively. Metallic behavior at normal temperatures and superconductivity below 5 K in diamond, synthesized in C-B system, change to semiconducting character of conductivity down to 2 K in diamonds obtained in the diluted systems; a faint hint of superconducting transition at 2 K was detected in the case of diamond grown in Ni-C-B system. By comparing phase composition of the inclusions and the doping efficiency of the diamonds, we are able to suggest that high chemical affinity of boron to boride-forming metals hinders the boron doping of diamond. The heavily boron-doped carbonado-like diamond compacts demonstrate high electrochemical activity in aqueous solutions and can be used as miniature electrodes in electrosynthesis and electroanalysis.
DS201812-2805
2018
Sidorov, V.A.Ekimov, E.A., Sidorov, V.A., Maslakov, K.I., Sirotinkin, B.P., Krotova, M.D., Pleskov, Yu.V.Influence of growth medium composition on the incorporation of boron in HPHT diamond.Diamond & Related Materials, Vol. 89, pp. 101-107.Mantlecarbonado
DS1989-1389
1989
Sidorov, Ye.G.Sidorov, Ye.G.Picrite finds on Karaginskiy Island, Bering SeaDoklady Academy of Science USSR, Earth Science Section, Vol. 297, No. 1-6, pp. 108-110RussiaPicrite
DS1991-0079
1991
Sidorov, Ye.G.Batanova, V.G., Astrakhantsev, O.V., Sidorov, Ye.G.The dunites of the Galmoenansk pluton, Koryak HighlandsInternational Geology Review, Vol. 33, No. 1, January pp. 62-73RussiaDunites, Ultramafics
DS201201-0861
2011
Sidra, O.I.Zaitsev, A.N., Chakmouradian, A.R., Sidra, O.I., Spratt, J., Williams, Stanley, Petrov, Britvin, PolyakaFlourine , yttrium and lanthaide rich cerianite (Ce) from carbonatitic rocks of the Kerimasi volcano and surrounding explosive craters Gregory Rift Tanzania.Mineralogical Magazine, Vol. 75, 6, pp. 2813-2822.Africa, TanzaniaCarbonatite
DS1992-0606
1992
Sie, S.Green, T.H., Adam, J., Sie, S.Trace element partitioning and mantle Metasomatism11th. Australian Geol. Convention Held Ballarat University College, Jan., Listing of papers to be given attempting to get volAustraliaGeochemistry, Mantle
DS1992-0610
1992
Sie, S.Greig, A., Nicholls, I., Sie, S.Metasomatism of the upper mantle by melts: a proton microprobe study11th. Australian Geol. Convention Held Ballarat University College, Jan., AbstractAustraliaMantle, Microprobe
DS1988-0270
1988
Sie, S.H.Griffin, W.L., Jaques, A.L., Sie, S.H., Ryan, C.G., Cousens, D.R.Conditions of diamond growth: a proton microprobe study of inclusions inWest Australian diamondsContributions to Mineralogy and Petrology, Vol. 99, No. 2, pp. 143-158AustraliaDiamond morphology
DS1989-0548
1989
Sie, S.H.Griffin, W.L., Cousens, D.R., Ryan, C.G., Sie, S.H., Suter, G.F.Application of the proton microprobe to diamond exploration and genesisMinpet 89 Mineralogy And Petrology Symposium Held Sydney, February, p. 13-14. AbstractAustraliaDiamond morphology, Microprobe
DS1989-0550
1989
Sie, S.H.Griffin, W.L., Gurney, J.J., Ryan, C.G., Cousens, D.R., Sie, S.H.Trapping temperatures and trace elements in P type garnets indiamonds:a proton microprobe studyDiamond Workshop, International Geological Congress, July 15-16th. editors, pp. 23-25. AbstractSouth AfricaGeochemistry Analyses, Diamond morphology
DS1989-1390
1989
Sie, S.H.Sie, S.H., Ryan, C.G., Cousens, D.R., Griffin, W.L.Application of the proton microprobe in mineral exploration andprocessingNucl. Instrum. Methods Phys. Res. Section, B., Vol. B40-B41, No. 1, 1988, pp. 690-697GlobalMicroprobe, Mineral analyses-kimberli
DS1991-1612
1991
Sie, S.H.Smith, D., Griffin, W.L., Ryan, C.G., Sie, S.H.Trace element zonation in garnets from the Thumb -heating and melt infiltration below the Colorado PlateauContributions to Mineralogy and Petrology, Vol. 107, No. 1, pp. 60-79Colorado PlateauGeochemistry, Garnets -Thumb
DS1992-0605
1992
Sie, S.H.Green, T.H., Adam, ., Sie, S.H.Trace element partitioning between silicate minerals and carbonatite at 25Kbar and application to mantle MetasomatismMineralogy and Petrology, Vol. 46, No. 3, pp. 179-184MantleSilicates, Metasomatism
DS1992-1506
1992
Sie, S.H.Sweeney, R.J., Green, D.H., Sie, S.H.Trace and minor element partioning between garnet and amphibole and carbonatitic meltEarth and Planetary Science Letters, Vol. 113, No. 1-2, September pp. 1-14GlobalCarbonatite, Mineral chemistry
DS1993-0574
1993
Sie, S.H.Green, T.H., Adam, J., Sie, S.H.Proton microprobe determined trace element partition coefficients betweenpargasite, augite and silicate of carbonatitic meltsEos, Transactions, American Geophysical Union, Vol. 74, No. 16, April 20, supplement abstract p. 340GlobalMineral chemistry, Carbonatite
DS201212-0510
2012
Siea, F.Natali, C., Beccaluva, L., Bianchini, G., Ellam, R.M., Siea, F., Stuart, F.M.Carbonated alkali silicate metasomatism in the North Africa lithosphere: evidence from middle Atlas spinel lherzolites, Morocco.Journal of South American Earth Sciences, in press availableAfrica, MoroccoGeochemistry
DS2003-0245
2003
Siebel, W.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
Siebel, W.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
DS200512-0390
2004
Siebel, W.Halama, R., Vennnemann, T., Siebel, W., Markl, G.The Gronnedal Ika carbonatite syenite complex, South Greenland: carbonatite formation by liquid immiscibility.Journal of Petrology, Vol. 46, 1-2, pp. 191-217.Europe, GreenlandCarbonatite
DS200512-0963
2004
Siebel, W.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
DS200812-0484
2008
Siebel, W.Hopp, J., Trieloff, M., Brey, G.P., Woodland, A.B., Simon, N.S.C., Wijbrans, J.R., Siebel, W., Reitter, E.40 Ar 39 Ar ages of phlogopite in mantle xenoliths from South African kimberlites: evidence for metasomatic mantle impregnation during Kilbaran orogenic cycle.Lithos, Vol. 106, no. 3-4, pp. 351-364.Africa, South Africa, LesothoDeposit - Bultfontein, Letseng, Liqhobong
DS202004-0546
2020
Siebel, W.Xiang, L., Zheng, J., Zhai, M., Siebel, W.Geochemical and Sr-Nd-Pb isotopic constraints on the origin and petrogenesis of Paleozoic lamproites in the southern Yangtze Block, south China.Contributions to Mineralogy and Petrology, Vol. 175, 18p. PdfChinalamproites

Abstract: Lamproites and kimberlites are natural probes of the subcontinental lithospheric mantle providing insights into the Earth’s continental lithosphere. Whole-rock major-, trace-element and Sr-Nd-Pb isotopic compositions of the Paleozoic (~?253 Ma) lamproite dikes from the Baifen zone of the Zhenyuan area in southeastern Guizhou Province (in the southern Yangtze Block, South China) are presented. The Baifen lamproites are characterized by high MgO (7.84-14.1 wt%), K2O (3.94-5.07 wt%) and TiO2 (2.69-3.23 wt%) contents, low SiO2 (41.3-45.7 wt%), Na2O (0.21-0.28 wt%) and Al2O3 (6.10-7.20 wt%) contents. All lamproites have elevated Cr (452-599 ppm) and Ni (485-549 ppm) abundances, as well as high Ba (1884-3589 ppm), La (160-186 ppm), Sr (898-1152 ppm) and Zr (532-632 ppm) concentrations. They show uniform REE distribution patterns that are strongly enriched in light REEs relative to heavy REEs [(La/Yb)N?=?71.1-87.6], and exhibit OIB-like geochemical features with obvious enrichment of both LILEs and HFSEs in the primitive mantle-normalized multi-element distribution diagram. Moderately radiogenic Sr (87Sr/86Sri?=?0.706336-0.707439), unradiogenic Nd (143Nd/144Ndi?=?0.511687-0.511704 and eNd(t)?=??-?12.2 to?-?11.9), and low initial Pb (206Pb/204Pbi?=?16.80-16.90, 207Pb/204Pbi?=?15.34-15.35 and 208Pb/204Pbi?=?37.43-37.70) isotopic compositions are obtained from the rocks. They yield old model ages of TDM(Nd)?=?1.48-1.54 Ga. These signatures suggest that the Baifen lamproite magmas are alkaline, ultrapotassic and ultramafic in character and mainly represent mantle-derived primary melts, which have undergone insignificant crustal contamination and negligible fractional crystallization. The Baifen lamproites originated from a veined metasomatized lithospheric mantle source. We envisage that they were derived by partial melting of old, mineralogically complex metasomatic vein assemblages in the subcontinental lithospheric mantle beneath the southern Yangtze Block. The source region experienced ancient mantle metasomatism with complex modification by enriched fluids and melts. The metasomatic agents are most likely to originate from pre-existing slab subduction beneath the southeastern margin of the Yangtze Block. Tectonically, the Baifen lamproites were emplaced at the southern margin of the Yangtze Block, and they formed in an intraplate extensional setting, showing an anorogenic affinity. In terms of time and space, the genesis of Baifen lamproites is presumably related to the Emeishan large igneous province. The Emeishan mantle plume is suggested as an effective mechanism for rapid extension and thinning of the lithosphere, followed by decompression melting of the subcontinental lithospheric mantle. Combined with the thermal perturbation from asthenospheric upwelling induced by the Emeishan mantle plume, the lamproite magmas, representing small volume and limited partial melts of ancient enriched mantle lithosphere, arose. We propose that the generation of the Baifen lamproite dikes probably was a consequence of the far-field effects of the Emeishan mantle plume.
DS201504-0185
2015
Siebenaller, L.Block, S., Ganne, J., Baratoux, A.Z., Parra-Avila, L.A., Jessell, M., Ailleres, L., Siebenaller, L.Petrological and geochronological constraints on lower crust exhumation during Paleoproterozoic (Eburnean) Orogeny, NW Ghana, West African craton.Journal of Metamorphic Geology, Vol. 33, 5, pp. 463-494.Africa, GhanaGeochronology

Abstract: New petrological and geochronological data are presented on high-grade ortho- and paragneisses from northwestern Ghana, forming part of the Paleoproterozoic (2.25-2.00 Ga) West African Craton. The study area is located in the interference zone between N-S and NE--SW-trending craton-scale shear zones, formed during the Eburnean orogeny (2.15-2.00 Ga). High-grade metamorphic domains are separated from low-grade greenstone belts by high-strain zones, including early thrusts, extensional detachments and late-stage strike-slip shear zones. Paragneisses sporadically preserve high-pressure, low-temperature (HP-LT) relicts, formed at the transition between the blueschist facies and the epidote-amphibolite sub-facies (10.0-14.0 kbar, 520-600 °C), and represent a low (~15 °C km-1) apparent geothermal gradient. Migmatites record metamorphic conditions at the amphibolite-granulite facies transition. They reveal a clockwise pressure-temperature-time (P-T-t) path characterized by melting at pressures over 10.0 kbar, followed by decompression and heating to peak temperatures of 750 °C at 5.0-8.0 kbar, which fit a 30 °C km-1 apparent geotherm. A regional amphibolite facies metamorphic overprint is recorded by rocks that followed a clockwise P-T-t path, characterized by peak metamorphic conditions of 7.0-10.0 kbar at 550-680 °C, which match a 20-25 °C km-1 apparent geotherm. These P-T conditions were reached after prograde burial and heating for some rock units, and after decompression and heating for others. The timing of anatexis and of the amphibolite facies metamorphic overprint is constrained by in-situ U-Pb dating of monazite crystallization at 2138 ± 7 and 2130 ± 7 Ma respectively. The new data set challenges the interpretation that metamorphic breaks in the West African Craton are due to diachronous Birimian ‘basins’ overlying a gneissic basement. It suggests that the lower crust was exhumed along reverse, normal and transcurrent shear zones and juxtaposed against shallow crustal slices during the Eburnean orogeny. The craton in NW Ghana is made of distinct fragments with contrasting tectono-metamorphic histories. The range of metamorphic conditions and the sharp lateral metamorphic gradients are inconsistent with ‘hot orogeny’ models proposed for many Precambrian provinces. These findings shed new light on the geodynamic setting of craton assembly and stabilization in the Paleoproterozoic. It is suggested that the metamorphic record of the West African Craton is characteristic of Paleoproterozoic plate tectonics and illustrates a transition between Archean and Phanerozoic orogens.
DS200512-0942
2005
Siebenschock, M.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
DS1910-0039
1910
Siebenthal, C.E.Darton, N.H., Blackwelder, E., Siebenthal, C.E.Laramie Sherman Folio, WyomingUnited States Geological Survey (USGS) ATLAS of THE UNITED STATES, 17P.United States, Wyoming, Rocky MountainsRegional Geology
DS201312-0824
2013
Sieber, M.Sieber, M., Brey, G.P., Seitz, H-M., Gerdes, A., Hoefer, H.E.The age of eclogitisation underneath the Kaapvaal craton - a composite xenolith from Roberts Victor.Goldschmidt 2013, 1p. AbstractAfrica, South AfricaDeposit - Roberts Victor
DS201412-0824
2014
Sieber, M.Sieber, M.A composite garnet pyroxenite xenolith yields a minimum age of 2.4 Ga for eclogitisation in the Kaapvaal subcratonic mantle.ima2014.co.za, PosterAfrica, South AfricaGeochronology
DS201112-0099
2011
SiebertBoulard, E., Menguyy, Auzende, Benzerara, Bureau, Antonangeli, Corgne, Morard, Siebert, Perrilat, GuyotExperimental investigation of the stability of Fe rich carbonates in the lower mantle.Goldschmidt Conference 2011, abstract p.561.MantleCarbon reduced.... diamonds
DS1970-0301
1971
Siebert, C.Gurney, J.J., Mathias, M., Siebert, C., Moseley, G.Kyanite Eclogites from the Rietfontein Kimberlite Pipe, Mier Coloured Reserve, Gordonia, Cape Province, South Africa.Contributions to Mineralogy and Petrology, Vol. 30, No. 1, PP. 46-52.South AfricaMineralogy
DS200512-0982
2005
Siebert, J.Siebert, J., Guyot, F., Malavergne, V.Diamond formation in metal? carbonate interactions.Earth and Planetary Science Letters, Vol. 229, 3-4, pp. 205-216.UHP, Earth differentiation, diamond genesis
DS200812-0069
2008
Siebert, J.Auzende, A-L., Badro, J., Ryerson, F.J., Weber, P.K., Fallon, S.J., Addad, A., Siebert, J., Fiquet, G.Element partitioning between magnesium silicate perovskite and ferropericlase: new insights into bulk lower mantle geochemistry.Earth and Planetary Science Letters, Vol. 269, 1-2, May 15, pp. 164-174.MantleGeochemistry
DS200912-0127
2009
Siebert, J.Corgne, A., Siebert, J., Badro, J.Oxygen as a light element: a solution to single stage core formation.Earth and Planetary Science Letters, Vol. 288, 1-2, pp. 108-114.MantlePetrology
DS201112-0321
2011
Siebert, J.Fiquet, G., Auzende, A.L., Siebert, J., Corgne, A., Bureau, H., Ozawa, H., Garbarino, G.Melting of peridotite to 140 GPa.Goldschmidt Conference 2011, abstract p.848.MantleGeotherms
DS201212-0098
2012
Siebert, J.Bureau, H., Langenhorst, F., Auzende, A-L., Frost, D.J., Esteve, I., Siebert, J.The growth of fibrous, cloudy and polycrystalline diamonds.Geochimica et Cosmochimica Acta,, Vol. 77, pp. 202-214.TechnologyDiamond morphology
DS201312-0825
2013
Siebert, J.Siebert, J., Badro, J., Antonangeli, D., Ryerson, F.J.Terrestrial accretion under oxidizing conditions.Science, Vol. 339, 6124, March 8, pp. 1194-1197.MantleMetal-silicate - core formation
DS201609-1703
2016
Siebert, J.Badro, J., Siebert, J., Ninmo, F.An early geodynamo driven by exsolution of mantle components from Earth's core.Nature, Vol. 536, Aug. 18, pp. 326-328.MantleCore, mantle boundary

Abstract: Recent palaeomagnetic observations1 report the existence of a magnetic field on Earth that is at least 3.45 billion years old. Compositional buoyancy caused by inner-core growth2 is the primary driver of Earth’s present-day geodynamo3, 4, 5, but the inner core is too young6 to explain the existence of a magnetic field before about one billion years ago. Theoretical models7 propose that the exsolution of magnesium oxide—the major constituent of Earth’s mantle—from the core provided a major source of the energy required to drive an early dynamo, but experimental evidence for the incorporation of mantle components into the core has been lacking. Indeed, terrestrial core formation occurred in the early molten Earth by gravitational segregation of immiscible metal and silicate melts, transporting iron-loving (siderophile) elements from the silicate mantle to the metallic core8, 9, 10 and leaving rock-loving (lithophile) mantle components behind. Here we present experiments showing that magnesium oxide dissolves in core-forming iron melt at very high temperatures. Using core-formation models11, we show that extreme events during Earth’s accretion (such as the Moon-forming giant impact12) could have contributed large amounts of magnesium to the early core. As the core subsequently cooled, exsolution7 of buoyant magnesium oxide would have taken place at the core-mantle boundary, generating a substantial amount of gravitational energy as a result of compositional buoyancy. This amount of energy is comparable to, if not more than, that produced by inner-core growth, resolving the conundrum posed by the existence of an ancient magnetic field prior to the formation of the inner core.
DS201610-1843
2016
Siebert, J.Badro, J., Siebert, J., Nimmo, F.An early geodynamo driven by exsolution of mantle components from Earth's core.Nature, Vol. 536, 7616, 4p.MantleMagnesium oxide

Abstract: Recent palaeomagnetic observations report the existence of a magnetic field on Earth that is at least 3.45 billion years old. Compositional buoyancy caused by inner-core growth is the primary driver of Earth's present-day geodynamo, but the inner core is too young to explain the existence of a magnetic field before about one billion years ago. Theoretical models propose that the exsolution of magnesium oxide--the major constituent of Earth's mantle--from the core provided a major source of the energy required to drive an early dynamo, but experimental evidence for the incorporation of mantle components into the core has been lacking. Indeed, terrestrial core formation occurred in the early molten Earth by gravitational segregation of immiscible metal and silicate melts, transporting iron-loving (siderophile) elements from the silicate mantle to the metallic core and leaving rock-loving (lithophile) mantle components behind. Here we present experiments showing that magnesium oxide dissolves in core-forming iron melt at very high temperatures. Using core-formation models, we show that extreme events during Earth's accretion (such as the Moon-forming giant impact) could have contributed large amounts of magnesium to the early core. As the core subsequently cooled, exsolution of buoyant magnesium oxide would have taken place at the core-mantle boundary, generating a substantial amount of gravitational energy as a result of compositional buoyancy. This amount of energy is comparable to, if not more than, that produced by inner-core growth, resolving the conundrum posed by the existence of an ancient magnetic field prior to the formation of the inner core.
DS201810-2351
2018
Siebert, J.Mahan, B., Siebert, J., Blanchard, I., Moynier, F.Investigating Earth's formation history through copper & sulfur metal silicate partitioning during core-mantle differentiation.Journal of Geophysical Research: Solid Earth, doi:10.1029/2018JB015991Mantlecore mantle boundary

Abstract: Experiments wherein molten metal and silicate (rock-building) phases un-mix themselves due to their physical properties, i.e. metal-silicate partitioning, can be conducted at the high temperatures and pressures (HP-HT) that characterized Earth's differentiation into a core and mantle. The redistribution of elements between the metal and silicate phases - their partitioning - during this process can be measured and mathematically described, then placed into numerical models to better understand Earth's formation history. Here, we have mathematically characterized the HP-HT partitioning of copper, combined this with results for sulfur from literature, and input these characterizations into numerical models that track their distribution between Earth's core and mantle as it grows to its present mass. Copper and sulfur were chosen because they display different sensitivities to the physical mechanisms that govern planetary formation, and we can leverage this to better understand Earth's formation and differentiation history. Our results indicate that ~75% of Earth's precursor materials grew incrementally from relatively small bits of material - on average ~0.1% of Earth's mass or less - that is most compositionally similar to meteorite classes that are made up of iron-rich metal and silicate solids (chondrules) that are depleted in easily vaporized (volatile) elements, especially sulfur.
DS201902-0258
2018
Siebert, J.Badro, J., Aubert, J., Hirose, K., Nomura, R., Blanchard, I., Borensztajn, S., Siebert, J.Magnesium partitioning between Earth's mantle and core and its potential to drive an early exsolution geodynamo.Geophysical Research Letters, Vol. 45, 24, pp. 13,240-13,248.Mantlegeodynamics

Abstract: We measure the incorporation of magnesium oxide (one of the main components of Earth's mantle) into iron (the main constituent Earth's core), using extremely high pressure and temperature experiments that mimic the conditions of Earth's mantle and core. We find that magnesium oxide dissolution depends on temperature but not on pressure, and on metal (i.e., core) composition but not silicate (i.e., mantle) composition. Our findings support the idea that magnesium oxide dissolved in the core during its formation will precipitate out during subsequent core cooling. The precipitation should stir the entire core to produce a magnetic field in Earth's distant past, at least as intense as the present-day field.
DS1960-1012
1968
Siebert, J.C.Rickwood, P.C., Mathias, M., Siebert, J.C.A Study of Garnets from Eclogite and Peridotite Xenoliths Found Inkimberlite.Contributions to Mineralogy and Petrology, Vol. 19, pp. 271-301.South AfricaGarnet Mineralogy, Deposit - Bultfontein, De Beers, Dutoitspan, Kamfersdam
DS1960-1013
1968
Siebert, J.C.Rickwood, P.C., Mathias, M., Siebert, J.C.A Study of Garnets from Eclogite and Peridotite Xenoliths Found in Kimberlite.Contributions to Mineralogy and Petrology, Vol. 19, No. 4, PP. 271-301.South AfricaPetrography, Mineralogy
DS1960-1024
1968
Siebert, J.C.Siebert, J.C.Mineralogy and Petrology of Ultramafic Xenoliths in Kimberlites.Msc. Thesis, University of Cape Town., South AfricaMineralogy
DS1960-1120
1969
Siebert, J.C.Gurney, J.J., Siebert, J.C., Whitfield, G.G.A Diamondiferous Eclogite from the Roberts Victor Mine in Upper Mantle Project.Geological Society of South Africa SPECIAL Publishing, No. 2, PP. 351-357.South AfricaPetrography
DS1970-0133
1970
Siebert, J.C.L.Mathias, M., Siebert, J.C.L., Rickwood, P.C.Some Aspects of the Mineralogy and Petrology of Ultramafic Xenoliths in Kimberlite.Contributions to Mineralogy and Petrology, Vol. 26, No. 2, PP. 75-123.Tanzania, East AfricaMineralogy, Petrology
DS1975-0391
1976
Siebert.Reid, A.M., Brown, R.W., Dawson, J.B., Whitfield, G.G., Siebert.Garnet and Pyroxene Composition in Some Diamondiferous Eclogites.Contributions to Mineralogy and Petrology, Vol. 58, PP. 203-220.Tanzania, East AfricaPetrography, Mineral Chemistry
DS201711-2528
2017
Siegel, C.Siegel, C., Bryan, S.E., Allen, C.M.Use and abuse of zircon based thermometers: a critical review and a recommended approach to identify antecrystic zircons.Earth-Science Reviews, Vol. 176, pp. 87-116.Technologygeothermometry

Abstract: Zircon- and bulk-rock Zr-based thermometric parameters have become fundamental to petrogenetic models of magmatism, from which broader geochronological and tectonic implications are being made. In particular, petrogenetic models have become increasingly reliant on Ti concentration in zircon geothermometry (TZircTi) and zircon saturation temperature (TZircsat). A feature of many of these studies is an implicit assumption that all zircons present in the host igneous rock are autocrystic, that is, crystallised from the surrounding melt. However, it has long been recognised that zircons present in an igneous rock can be inherited either from the surrounding country rock or source region (xenocrysts), or from earlier phases of magmatism or the magmatic plumbing system (antecrysts). Distinguishing these different origins for zircon crystals or domains within crystals is not straightforward. Here, we first review the utility and reliability of zircon-based thermometers for petrogenetic studies and show that TZircsat is a theoretical temperature and cannot be used to constrain magmatic or partial melting temperatures. It is a dynamic variable that changes during magma crystallisation, and essentially increases as fractional crystallisation proceeds, whereas true magmatic temperatures (TMagma) decrease. Generally, in Temperature-SiO2 space, the cross-over point of these two temperatures is magmatic system dependent, and also affected by the type of calibration used for the TZircsat calculations. Consequently, each magmatic system needs to be evaluated independently to assess the validity and usefulness of TZircsat. A fundamental conclusion of TZircsat and TMagma relationships assessed here is that new zircon generally only crystallises in silicic (granitic/rhyolitic) melt compositions, and thus autocrystic zircons should not be assumed to be present in igneous rocks with bulk compositions < 64 wt% SiO2, although inherited and minor zircons crystallising from late-stage differentiated melt pockets can be present. This highlights the importance of discriminating autocrystic from inherited zircons in igneous rocks. We then review techniques available to discriminate autocrystic from inherited zircons, and propose a new methodology to assist in the identification of autocrystic zircons for emplacement age determination and separate evaluation of inherited zircon components. The approach uses two strands of data: 1) zircon data such as zircon morphologies, textures, compositions and U-Pb ages, and 2) whole-rock data, in particular SiO2 and coupled geothermometry (TZircsat and TMagma) to estimate whether the magma was zircon-saturated or undersaturated. To test this new protocol, we use as examples, several Phanerozoic granitic rocks intersected by drilling in Queensland where contextual information is limited, and show how antecrystic and xenocrystic zircons and monazites can be distinguished. In contrast, where zircons are metamict (for example, high U and Th-rich zircons), much of the ability to discriminate is impacted because such zircons have suffered Pb loss and have modified compositions (e.g., higher TZircTi). We recommend an integrated approach incorporating whole-rock chemistry, independent geothermometric constraints, zircon composition, textures and ages obtained by routine cathodoluminescence and LA-ICP-MS or ion microprobe analysis to provide increased confidence for the discrimination of inherited zircons from autocrystic zircons and determination of the emplacement age.
DS201712-2730
2017
Siegel, C.Siegel, C., Bryan, S.E., Allen, C.M., Gust, D.A.Use and abuse of zircon based thermometers: a critical review and recommended approach to identify antecrystic zircons.Earth Science Reviews, Vol. 176, 10.1016Technologygeothermometry

Abstract: Zircon- and bulk-rock Zr-based thermometric parameters have become fundamental to petrogenetic models of magmatism, from which broader geochronological and tectonic implications are being made. In particular, petrogenetic models have become increasingly reliant on Ti concentration in zircon geothermometry (TZircTi) and zircon saturation temperature (TZircsat). A feature of many of these studies is an implicit assumption that all zircons present in the host igneous rock are autocrystic, that is, crystallised from the surrounding melt. However, it has long been recognised that zircons present in an igneous rock can be inherited either from the surrounding country rock or source region (xenocrysts), or from earlier phases of magmatism or the magmatic plumbing system (antecrysts). Distinguishing these different origins for zircon crystals or domains within crystals is not straightforward. Here, we first review the utility and reliability of zircon-based thermometers for petrogenetic studies and show that TZircsat is a theoretical temperature and cannot be used to constrain magmatic or partial melting temperatures. It is a dynamic variable that changes during magma crystallisation, and essentially increases as fractional crystallisation proceeds, whereas true magmatic temperatures (TMagma) decrease. Generally, in Temperature-SiO2 space, the cross-over point of these two temperatures is magmatic system dependent, and also affected by the type of calibration used for the TZircsat calculations. Consequently, each magmatic system needs to be evaluated independently to assess the validity and usefulness of TZircsat. A fundamental conclusion of TZircsat and TMagma relationships assessed here is that new zircon generally only crystallises in silicic (granitic/rhyolitic) melt compositions, and thus autocrystic zircons should not be assumed to be present in igneous rocks with bulk compositions < 64 wt% SiO2, although inherited and minor zircons crystallising from late-stage differentiated melt pockets can be present. This highlights the importance of discriminating autocrystic from inherited zircons in igneous rocks. We then review techniques available to discriminate autocrystic from inherited zircons, and propose a new methodology to assist in the identification of autocrystic zircons for emplacement age determination and separate evaluation of inherited zircon components. The approach uses two strands of data: 1) zircon data such as zircon morphologies, textures, compositions and U-Pb ages, and 2) whole-rock data, in particular SiO2 and coupled geothermometry (TZircsat and TMagma) to estimate whether the magma was zircon-saturated or undersaturated. To test this new protocol, we use as examples, several Phanerozoic granitic rocks intersected by drilling in Queensland where contextual information is limited, and show how antecrystic and xenocrystic zircons and monazites can be distinguished. In contrast, where zircons are metamict (for example, high U and Th-rich zircons), much of the ability to discriminate is impacted because such zircons have suffered Pb loss and have modified compositions (e.g., higher TZircTi). We recommend an integrated approach incorporating whole-rock chemistry, independent geothermometric constraints, zircon composition, textures and ages obtained by routine cathodoluminescence and LA-ICP-MS or ion microprobe analysis to provide increased confidence for the discrimination of inherited zircons from autocrystic zircons and determination of the emplacement age.
DS201910-2262
2019
Siegel, R.Gruninger, H., Liu, Z., Siegel, R., Boffa Ballaran, T., Katsura, T., Senker, J., Frost, F.J.Oxygen vacancy ordering in aluminous bridgmanite in the Earth's lower mantle.Geophysical Research Letters, Vol. 46, 15, pp. 8731-8740.Mantlebridgmanite

Abstract: The lower mantle encompasses the largest region of the Earth's interior and is mainly composed of the perovskite-structured mineral (Mg,Fe,Al)(Al,Si)O3 bridgmanite. Its properties, therefore, control both the diffusive transport of elements and solid state flow in the lower mantle, which will be strongly influenced by point defects. We have identified and quantified defects in bridgmanite that arise from the replacement of silicon by aluminum and result in the creation of a vacant oxygen site. These oxygen defects are also found to form clusters in the structure, which in other perovskite structured minerals have been shown to strongly affect physical properties. As defect formation and ordering is dependent on composition and pressure, strong variations in physical properties may be expected within the upper 300 km of the lower mantle.
DS200412-1082
2004
Siegesmund, S.Lana, C., Reimold, W.U., Gibson, R.L., Koeberl, C., Siegesmund, S.Nature of the Archean midcrust in the core of the Vredfort dome, Central Kaapvaal Craton, South Africa.Geochimica et Cosmochimica Acta, Vol. 68, 3, pp. 623-42.Africa, South AfricaCraton, not specific to diamonds
DS201112-0765
2011
Siegesmund, S.Oyhantcabal, P., Siegesmund, S., Wemmer, K.The Rio de la Plat a craton: a review of units, boundaries, ages and isotopic signature.International Journal of Earth Sciences, Vol. 100, 2, pp. 201-220.South America, ArgentinaCraton, not specific to diamonds
DS201707-1355
2017
Siegesmund, S.Oriolo, S., Oyhantcabal, P., Wemmer, K., Siegesmund, S.Contemporaneous assembly of Western Gondwana and final Rodinia break-up: implications for the supercontinent cycle.Geoscience Frontiers, in press available 15p.Gondwana, Rodiniageodynamics

Abstract: Geological, geochronological and isotopic data are integrated in order to present a revised model for the Neoproterozoic evolution of Western Gondwana. Although the classical geodynamic scenario assumed for the period 800–700 Ma is related to Rodinia break-up and the consequent opening of major oceanic basins, a significantly different tectonic evolution can be inferred for most Western Gondwana cratons. These cratons occupied a marginal position in the southern hemisphere with respect to Rodinia and recorded subduction with back-arc extension, island arc development and limited formation of oceanic crust in internal oceans. This period was thus characterized by increased crustal growth in Western Gondwana, resulting from addition of juvenile continental crust along convergent margins. In contrast, crustal reworking and metacratonization were dominant during the subsequent assembly of Gondwana. The Río de la Plata, Congo-São Francisco, West African and Amazonian cratons collided at ca. 630–600 Ma along the West Gondwana Orogen. These events overlap in time with the onset of the opening of the Iapetus Ocean at ca. 610–600 Ma, which gave rise to the separation of Baltica, Laurentia and Amazonia and resulted from the final Rodinia break-up. The East African/Antarctic Orogen recorded the subsequent amalgamation of Western and Eastern Gondwana after ca. 580 Ma, contemporaneously with the beginning of subduction in the Terra Australis Orogen along the southern Gondwana margin. However, the Kalahari Craton was lately incorporated during the Late Ediacaran–Early Cambrian. The proposed Gondwana evolution rules out the existence of Pannotia, as the final Gondwana amalgamation postdates latest connections between Laurentia and Amazonia. Additionally, a combination of introversion and extroversion is proposed for the assembly of Gondwana. The contemporaneous record of final Rodinia break-up and Gondwana assembly has major implications for the supercontinent cycle, as supercontinent amalgamation and break-up do not necessarily represent alternating episodic processes but overlap in time.
DS201708-1572
2017
Siegesmund, S.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.
DS201803-0469
2017
Siegesmund, S.Oriolo, S., Oyhantcabal, P., Wemmer, K., Siegesmund, S.Contemporaneous assembly of western Gondwana and final Rodinia break up: implications for the supercontinent cycle.Geoscience Frontiers, Vol. 8, pp. 1431-1445.South America, Braziltectonics

Abstract: Geological, geochronological and isotopic data are integrated in order to present a revised model for the Neoproterozoic evolution of Western Gondwana. Although the classical geodynamic scenario assumed for the period 800-700 Ma is related to Rodinia break-up and the consequent opening of major oceanic basins, a significantly different tectonic evolution can be inferred for most Western Gondwana cratons. These cratons occupied a marginal position in the southern hemisphere with respect to Rodinia and recorded subduction with back-arc extension, island arc development and limited formation of oceanic crust in internal oceans. This period was thus characterized by increased crustal growth in Western Gondwana, resulting from addition of juvenile continental crust along convergent margins. In contrast, crustal reworking and metacratonization were dominant during the subsequent assembly of Gondwana. The Río de la Plata, Congo-São Francisco, West African and Amazonian cratons collided at ca. 630-600 Ma along the West Gondwana Orogen. These events overlap in time with the onset of the opening of the Iapetus Ocean at ca. 610-600 Ma, which gave rise to the separation of Baltica, Laurentia and Amazonia and resulted from the final Rodinia break-up. The East African/Antarctic Orogen recorded the subsequent amalgamation of Western and Eastern Gondwana after ca. 580 Ma, contemporaneously with the beginning of subduction in the Terra Australis Orogen along the southern Gondwana margin. However, the Kalahari Craton was lately incorporated during the Late Ediacaran-Early Cambrian. The proposed Gondwana evolution rules out the existence of Pannotia, as the final Gondwana amalgamation postdates latest connections between Laurentia and Amazonia. Additionally, a combination of introversion and extroversion is proposed for the assembly of Gondwana. The contemporaneous record of final Rodinia break-up and Gondwana assembly has major implications for the supercontinent cycle, as supercontinent amalgamation and break-up do not necessarily represent alternating episodic processes but overlap in time.
DS201804-0724
2016
Siegesmund, S.Oriolo, S., Oyhantcabal, P., Basei. M.A.S., Wemmer, K., Siegesmund, S.The Nico Perez terrane ( Uruguay): from Archean crustal growth and connections with the Congo Craton to late Neoproterozoic accretion to the Rio de la Plat a Craton.Precambrian Research, Vol. 280, pp. 147-160.South America, Uruguaycraton - Rio de la Plata

Abstract: New U-Pb and first Hf data were obtained from the Nico Pérez and Piedra Alta Terranes as well as from the Congo Craton. Results indicate that the Nico Pérez Terrane was mostly built during Archean episodic crustal growth and this crust underwent significant Paleo- and Neoproterozoic crustal reworking at ca. 2.2-2.0, 1.7 and 0.6 Ga. The Piedra Alta Terrane of the Río de la Plata Craton, in contrast, records only Paleoproteorozoic crustal growth. These evidences together with available geological, geochronological and isotopic data indicate the allochthony of the Nico Pérez Terrane. Furthermore, data point to an African origin of the Nico Pérez Terrane, particularly related to the southwestern Congo Craton. After Cryogenian rifting from the latter during Rodinia break-up, the Nico Pérez Terrane was accreted to the eastern Río de la Plata Craton along the Sarandí del Yí Shear Zone and underwent further crustal reworking during the evolution of the Dom Feliciano Belt.
DS2000-0390
2000
Siegfried, P.Harmer, R.E., Hayward, G., Siegfried, P., Gittins, J.The geology and economic potential of the Xiluvo carbonatite complex, Mozambique.Igc 30th. Brasil, Aug. abstract only 1p.GlobalCarbonatite, Deposit - Xiluvo
DS2001-1216
2001
Siegfried, P.Walsh, K.L., Siegfried, P., Hall, HughesTectonic implications of four recently discovered carbonatites along the Zambesi Escarpment Fault.Journal of South African Earth Sciences, Vol. 32, No. 1, p. A 36-7.(abs)ZimbabweCarbonatite, Marindagomo Complex, Dande-Doma
DS1999-0667
1999
Siegfried, P.R.Siegfried, P.R.The Monapo structure and intrusive complex - an example of large scale alkaline metasomatism in n. Mozambique.Stanley, SGA Fifth Biennial Symposium, pp. 683-6.GlobalAlkaline rocks
DS201802-0233
2018
Siegfried, P.R.Elliott, H.A.L., Wall, F., Chakmouradian, A.R., Siegfried, P.R., Dahlgren, S., Weatherley, S., Finch, A.A., Marks, M.A.W., Dowman, E., Deady, E.Fenites associated with carbonatite complexes: a review.Ore Geology Reviews, Vol. 92, pp. 38-59.Globalcarbonatites

Abstract: Carbonatites and alkaline-silicate rocks are the most important sources of rare earth elements (REE) and niobium (Nb), both of which are metals imperative to technological advancement and associated with high risks of supply interruption. Cooling and crystallizing carbonatitic and alkaline melts expel multiple pulses of alkali-rich aqueous fluids which metasomatize the surrounding country rocks, forming fenites during a process called fenitization. These alkalis and volatiles are original constituents of the magma that are not recorded in the carbonatite rock, and therefore fenites should not be dismissed during the description of a carbonatite system. This paper reviews the existing literature, focusing on 17 worldwide carbonatite complexes whose attributes are used to discuss the main features and processes of fenitization. Although many attempts have been made in the literature to categorize and name fenites, it is recommended that the IUGS metamorphic nomenclature be used to describe predominant mineralogy and textures. Complexing anions greatly enhance the solubility of REE and Nb in these fenitizing fluids, mobilizing them into the surrounding country rock, and precipitating REE- and Nb-enriched micro-mineral assemblages. As such, fenites have significant potential to be used as an exploration tool to find mineralized intrusions in a similar way alteration patterns are used in other ore systems, such as porphyry copper deposits. Strong trends have been identified between the presence of more complex veining textures, mineralogy and brecciation in fenites with intermediate stage Nb-enriched and later stage REE-enriched magmas. However, compiling this evidence has also highlighted large gaps in the literature relating to fenitization. These need to be addressed before fenite can be used as a comprehensive and effective exploration tool.
DS201903-0498
2019
Siegfried, P.R.Banks, G.J., Walter, B.F., Marks, M.A.W., Siegfried, P.R.A workflow to define, map and name a carbonatite-alkaline igneous-associated REE-HFSE mineral system: a case study from SW Germany.MDPI, Vol. 9, 97, 28p. PdfGlobalREE

Abstract: Security of supply of “hi-tech” raw materials (including the rare earth elements (REE) and some high-field-strength elements (HFSEs)) is a concern for the European Union. Exploration and research projects mostly focus on deposit- to outcrop-scale description of carbonatite- and alkaline igneous-associated REE-HFSE mineralization. The REE-HFSE mineral system concept and approach are at a nascent stage, so developed further here. However, before applying the mineral system approach to a chosen REE-HFSE metallogenic province its mineral system extent first needs defining and mapping. This shifts a mineral system project’s foundation from the mineral system concept to a province’s mineral system extent. The mapped extent is required to investigate systematically the pathways and potential trap locations along which the REE-HFSE mass may be distributed. A workflow is presented to standardize the 4-D definition of a REE-HFSE mineral system at province-scale: (a) Identify and hierarchically organize a mineral system’s genetically related sub-divisions and deposits, (b) map its known and possible maximum extents, (c) name it, (d) discern its size (known mineral endowment), and (e) assess the favorability of the critical components to prioritize further investigations. The workflow is designed to generate process-based perspective and improve predictive targeting effectiveness along under-evaluated plays of any mineral system, for the future risking, comparing and ranking of REE-HFSE provinces and plays.
DS201908-1769
2019
Siegfried, P.R.Alessio, B.L., Glorie, S., Collins, A.S., Jourdan, F., Jepson, G., Nixon, A., Siegfried, P.R., Clark, C.The thermo-tectonic evolution of the southern Congo craton margin as determined from apatite and muscovite thermochronology.Tectonophysics, Vol. 766, pp. 398-415.Africa, Zambia, Malawi, Mozambique, Tanzaniacraton

Abstract: The Southern Irumide Belt (SIB) of Zambia consists of predominantly Mesoproterozoic terranes that record a pervasive tectono-metamorphic overprint from collision between the Congo and Kalahari cratons in the final stages of Gondwana amalgamation. This study applies multi-method thermochronology to samples throughout southern Zambia to constrain the post-collisional, Phanerozoic thermo-tectonic evolution of the region. U-Pb apatite and 40Ar/39Ar muscovite data are used to constrain the cooling history of the region following Congo-Kalahari collision, and reveal ages of c. 550-450?Ma. Variations in the recorded cooling ages are interpreted to relate to localised post-tectonic magmatism and the proximity of analysed samples to the Congo-Kalahari suture. Apatite fission track data are used to constrain the low-temperature thermo-tectonic evolution of the region and identify mean central ages of c. 320-300, 210-200 and 120-110?Ma. Thermal modelling of these samples identifies a number of thermal events occurring in the region throughout the Phanerozoic. Carboniferous to Permian-Triassic heating is suggested to relate to the development of Karoo rift basins found throughout central Africa and constrain the timing of sedimentation in the basin. Permian to Jurassic cooling is identified in a number of samples, reflecting exhumation as a result of the Mauritanian-Variscan and Gondwanide orogenies. Subsequent cooling of the majority of samples occurs from the Cretaceous and persists until present, reflecting exhumation in response to larger scale rifting associated with the break-up of Gondwana. Each model reveals a later phase of enhanced cooling beginning at c. 30?Ma that, if not an artefact of modelling, corresponds to the development of the East African Rift System. The obtained thermochronological data elucidate the previously unconstrained thermal evolution of the SIB, and provides a refined regional framework for constraining the tectonic history of central Africa throughout the Phanerozoic.
DS1996-0474
1996
Siegfried P.R.Frimmel, H.E., Klotzli, U.S., Siegfried P.R.New lead Strontium single zircon age constraints on the timing of NeoProterozoic glaciation and continental break up.Journal of Geology, Vol. 104, No. 4, July pp. 459-470.NamibiaGeochronology, Geomorphology
DS201911-2562
2019
Siegrist, M.Siegrist, M., Yogodzinski, G., Bizimis, M., Fournelle, J., Churikova, T., Dektor, C., Mobley, R.Fragments of metasomatized forearc: origin and implications of mafic and ultramafic xenoliths from Kharchinsky volcano, Kamchatka.Geochemistry, Geophysics, Geosystems, Vol. 20, 9, pp. 4426-4456.Russiaxenoliths

Abstract: This paper presents the results of a study of rare rock fragments (xenoliths) that were transported from the Earth's deep interior to the surface during an eruption of Kharchinsky volcano, Kamchatka. The chemical compositions, mineralogy, and textures of the samples were studied with the goal of understanding the processes that affected rocks, which may play a role in the formation of magmas in the Kamchatka subduction zone. The key process that affected the xenoliths involved the addition of fluids and dissolved elements to the samples at temperatures of 500-700 °C. These fluids are derived from seawater that was transported to 30- to 50-km depths by subduction of the Pacific Plate beneath Kamchatka. Subsequent to the addition of fluid, there was a shift in the position of the Kamchatka-Pacific Plate boundary that led to an increase in temperature and the formation of small quantities of melt that crystallized to a distinctive group of secondary minerals that are present in the samples and that postdate (overprint) the initial effects of fluid addition. The final step in the evolution of the samples was infiltration by an Fe- and Mg-rich magma that crystallized principally amphibole-group minerals.
DS201312-0199
2013
Siejko, F.De Min, A., Hendriks, B., Siejko, F., Comin-Chiaramonti, P., Girardi, V., Ruberti, E., Gomes, C.B., Neder, R.D., Pinho, F.C.Age of ultramafic high K rocks from Planalto da Serra ( Mato Grosso, Brazil).Journal of South American Earth Sciences, Vol. 41, pp. 57-64.South America, BrazilGeochronology
DS200912-0240
2009
Siemens, K.Galloway, M., Nowicki, T., Van Coller, B., Mukodzani, B., Siemens, K., Hetman, C., Webb, K., Gurney, J.Constraining kimberlite geology through integration of geophysical, geological and geochemical methods: a case study of the Mothae kimberlite, northern Lesotho.Lithos, In press - available 47p.Africa, LesothoDeposit - Mothae
DS1998-1313
1998
Siemon, B.Sengpiel, K-P., Siemon, B.Examples of 1- D inversion of multifrequency HEM dat a from 3 - Dresistivity distributions.Exploration Geophysics, Vol. 29, No. 1-2, Aug. pp. 133-141.NamibiaGeophysics - HEM data for groundwater study
DS1960-0498
1964
Siems, P.L.Siems, P.L.Geology and Mineral Deposits of the Silver Cliff Volcanic Caldera, custer County, Colorado.Geological Society of America (GSA), Annual MEETING ROCKY MTN. SECTION, P. 39.United States, Colorado, Rocky MountainsDiatreme
DS1998-0096
1998
SienaBeccaluva, L., Siena, Coltori, Di Grande, et al.Nephelinitic to tholeitic magma generation in a transtensional tectonicsetting: integrated model...Journal of Petrology, Vol. 39, No. 9, pp. 1547-76.ItalyIblean volcanism., Tectonics - magmatism
DS2001-0096
2001
SienaBeccaluva, L., Bianchini, G., Coltorti, Perkins, SienaMultistage evolution of the European lithospheric mantle: new evidence Sardinian peridotite xenolithsContributions to Mineralogy and Petrology, Vol. 142, No. 3, Dec. pp. 284-97.SardiniaXenoliths - petrology
DS200712-0061
2007
SienaBeccaluva, L., Azzouni Sekkal, A., Benhallou, A., Bianchini, G., Ellam, R.M., Marzola, M., Siena, StuartIntracratonic asthenosphere upwelling and lithosphere rejuvenation beneath the Hoggar swell (Algeria): evidence from HIMU metasomatized lherzolite mantle.Earth and Planetary Science Letters, Vol. 260, 3-4, pp. 482-494.Africa, AlgeriaMetasomatism
DS200912-0122
2009
SienaColtorti, M., Downes, H., Gregoire, M., O'Reilly, S.Y., Beccaluva, L., Bonadiman, Piccardo.Rivalenti, SienaPetrological evolution of the European lithospheric mantle: from Archean to present day.Journal of Petrology, Vol. 50, no. 7, pp. 1181-1184.MantleMagmatism
DS2001-0097
2001
Siena, et al.Beccaluva, L., Blanchini, Coltori, Perkins, Siena, et al.Multistage evolution of the European lithospheric mantle: new evidence from Sardinian peridotite xenolithContribution Mineralogy Petrology, Vol. 142, No. 3, pp. 284-97.Sardinia, EuropePeridotite xenoliths
DS1993-1464
1993
Siena, F.Siena, F., Coltorti, M.Thermobarometric evolution and metasomatic processes of upper-mantle indifferent tectonic settings -evidence from spinel peridotite xenoliths.European Journal of Mineralogy, Vol. 5, No. 6, November-December pp. 1073-1090.MantleTectonics, Xenoliths
DS200412-0117
2004
Siena, F.Beccaluva, L., Bianchini, G., Bonadiman, C., Siena, F., Vaccaro, C.Coexisting anorogenic and subduction related metasomatism in mantle xenoliths from the Betic Cordillera ( southern Spain). TallaLithos, Vol. 75, 1-2, July pp. 67-87.Europe, SpainSubduction, trace element fingerprinting, petrogenetic
DS200412-0348
2004
Siena, F.Coltori, M., Beccaluva, L., Bonadiman, C., Faccini, B., Ntaflos, T., Siena, F.Amphibole genesis via metasomatic reaction with clinopyroxene in mantle xenoliths from Victoria Land, Antarctica. Mt. Melbourne,Lithos, Vol. 75, 1-2, July pp. 115-139.AntarcticaMetasomatism, trace element fingerprinting, glass
DS200612-0148
2005
Siena, F.Bonadiman, C., Beccaluva, L., Coltort, M., Siena, F.Kimberlite like metasomatism and garnet signature in spinel peridotite xenoliths from Sal, Cape Verde Archipelago: relics of subcontinental mantle domain.Journal of Petrology, Vol. 46, 12, pp. 2465-2493.Europe, Cape Verde IslandsMetasomatism
DS200612-0149
2006
Siena, F.Bonadiman, C., Coltorti, M., Siena,F., O'Reilly, S.Y., Griffin, W.L., Pearson, N.J.Archean to Proterozoic depletion in Cape Verde lithospheric mantle.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.Europe, Cape Verde IslandsGeochemistry
DS200812-0120
2008
Siena, F.Boanadiman, C., Coltari, M., Duggen, S., Paludetti, L., Siena,F.,Thirwall, M.F., Upton, BGJ.Paleozoic subduction related and kimberlite or carbonatite metasomatism in the Scottish lithospheric mantle.Geological Society of London, Special Publications no. 293, pp. 303-334.Europe, ScotlandSubduction
DS200812-0126
2008
Siena, F.Bonadiman, C., Coltorti, M., Beccaluva, L., Siena, F.Mantle metasomatism vs host magma interaction: the ongoing controversy.Goldschmidt Conference 2008, Abstract p.A95.MantleMetasomatism
DS201312-0638
2013
Siena, F.Natali, C., Beccaluva, L., Bianchini, G., Ellam, R.M., Siena, F., Stuart, F.M.Carbonated alkali silicate metasomatism in the North Africa lithosphere: evidence from Middle Atlas spinel lherzolites, Morocco.Journal of South American Earth Sciences, Vol. 41, pp. 113-121.Africa, MoroccoMetasomatism
DS201312-0800
2013
Siena, F.Sgualdo, P., Beccaluva, L., Bianchini, G., Siena, F.Mantle xenoliths from Bir Ali ( Yemen).Goldschmidt 2013, 1p. AbstractAfrica, YemenXenoliths
DS201702-0194
2017
Siena, F.Beccaluva, L., Bianchini, G., Natali, C., Siena, F.The alkaline carbonatite complex of Jacupiranga ( Brazil): magma genesis.Gondwana Research, Vol. 44, pp. 157-177.South America, BrazilCarbonatite

Abstract: A comprehensive study including new field, petrological and geochemical data is reported on the Jacupiranga alkaline-carbonatite complex (133-131 Ma) which, together with other alkaline complexes, occurs in southern Brazil and is coeval with the Paraná CFB province. It consists of a shallow intrusion (ca. 65 km2) in the Precambrian crystalline basement, and can be subdivided in two main diachronous plutonic bodies: an older dunite-gabbro-syenite in the NW and a younger clinopyroxenite-ijolite (s.l.) in the SE, later injected by a carbonatitic core (ca. 1 km2). An integrated petrogenetic model, based on bulk rock major and trace element analyses, mineral chemistry and Sr-Nd-Pb-C isotopic data, suggests that the two silicate intrusions generated from different mantle-derived magmas that evolved at shallow level (2-3 km depth) in two zoned cup-shaped plutonic bodies growing incrementally from independent feeding systems. The first intrusion was generated by OIB-like alkaline to mildly alkaline parental basalts that initially led to the formation of a dunitic adcumulate core, discontinuously surrounded by gabbroic cumulates, in turn injected by subanular syenite intrusive and phonolite dykes. Nephelinitic (± melilite) melts - likely generated deep in the lithosphere at = 3 GPa - were the parental magmas of the second intrusion and gave rise to large coarse-grained clinopyroxenite ad- to meso-cumulates, in turn surrounded, and partially cut, by semi-annular fine-layered melteigite-ijolite-urtite ortho-cumulates. The available isotopic data do not evidence genetic links between carbonatites and the associated silicate intrusions, thus favouring an independent source from the mantle. Moreover, it may be suggested that, unlike gabbro-syenites and carbonatites, mostly generated from lithospheric mantle sources, the parental magmas of the ijolite-clinopyroxenite intrusion also record the influence of sublithospheric (plume-related?) geochemical components.
DS201801-0042
2018
Siena, F.Natali, C., Beccaluva, L., Bianchini, G., Siena, F.Coexistence of alkaline carbonatite complexes and high MgO CFB in the Parana-Etendeka province: insights on plume lithosphere interactions in the Gondwana realm.Lithos, Vol. 296-299, pp. 54-66.South America, Brazilcarbonatites
DS201908-1788
2019
Siersch, N.Liu, Z., Greaux, S., Cai, N., Siersch, N., Boffa Ballaran, T., Irifune, T., Frost, D.J.Influence of aluminum on the elasticity of majorite pyrope garnets.American Mineralogist, Vol. 104, pp. 929-935.Mantlegarnets

Abstract: The effect of aluminum (Al) on the elasticity of majorite-pyrope garnets was investigated by means of ultrasonic interferometry measurements on well-fabricated polycrystalline specimens. Both velocities and elastic moduli increase almost linearly with increasing Al content within analytical uncertainty. No significant variation of the velocities and elastic moduli is observed across the tetragonal-to-cubic phase transition at majorite with the pyrope content up to 26 mol% along the majorite-pyrope system. The elasticity variation of majorite-pyrope garnets is largely dominated by the Al content, while the phase transition as a result of cation ordering/disordering of Mg and Si via substitution of Al on octahedral sites cannot significantly affect elastic properties. Seismic velocity variations of a garnet-bearing mantle transition zone are therefore dominated by garnet composition (e.g., Al, Fe, Ca, and Na) rather than the tetragonal-to-cubic phase transition because of cation ordering/disordering.
DS201909-2096
2019
Siersch, N.C.Thomson, A.R., Crichton, W.A., Brodholt, J.P., Wood, I.G., Siersch, N.C., Muir, J.M.R., Dobson, D.P., Hunt, S.A..Seismic velocities of CaSiO3 perovskite can explain LLSVPs in Earth's lower mantle.Nature, Vol. 572, 7769, 18p. PdfMantleperovskite

Abstract: Seismology records the presence of various heterogeneities throughout the lower mantle1,2, but the origins of these signals—whether thermal or chemical—remain uncertain, and therefore much of the information that they hold about the nature of the deep Earth is obscured. Accurate interpretation of observed seismic velocities requires knowledge of the seismic properties of all of Earth’s possible mineral components. Calcium silicate (CaSiO3) perovskite is believed to be the third most abundant mineral throughout the lower mantle. Here we simultaneously measure the crystal structure and the shear-wave and compressional-wave velocities of samples of CaSiO3 perovskite, and provide direct constraints on the adiabatic bulk and shear moduli of this material. We observe that incorporation of titanium into CaSiO3 perovskite stabilizes the tetragonal structure at higher temperatures, and that the material’s shear modulus is substantially lower than is predicted by computations3,4,5 or thermodynamic datasets6. When combined with literature data and extrapolated, our results suggest that subducted oceanic crust will be visible as low-seismic-velocity anomalies throughout the lower mantle. In particular, we show that large low-shear-velocity provinces (LLSVPs) are consistent with moderate enrichment of recycled oceanic crust, and mid-mantle discontinuities can be explained by a tetragonal-cubic phase transition in Ti-bearing CaSiO3 perovskite.
DS1983-0200
1983
Siesser, W.G.Dingle, R.V., Siesser, W.G., Newton, A.R.Mesozoic and Tertiary Geology of Southern AfricaA.a. Balkema., GlobalBlank
DS1992-1403
1992
Siever, R.Siever, R.The silica cycle in the PrecambrianGeochimica et Cosmochimica Acta, Vol. 56, No. 8, pp. 3265-3272GlobalPrecambrian, Geochemistry -silica
DS200812-0531
2008
Siffert, P.Jung, M., Morel, J., Siffert, P.Numerical simulations for diamond sensors as real time X-ray dosemeters; comparison to silicon.Nuclear Instruments and Methods in Physics Research Section A., No. 587, 1, pp. 125-129.TechnologyX-ray diamond sensors
DS201904-0757
2019
Sifre, S.Malavergegne, V., Bureau, H., Raepsaet, C., Gaillard, C., Poncet, F., Surble, M., Sifre, S., Shcheka, D., Fourdrin, S., Deldicque, C., Khodja, D., HichamExperimental constraints on the fate of H and C during planetary core-mantle differentiation. Implications for the Earth.Icarus - New York, Vol. 321, 1, pp. 473-485.Mantlecarbon

Abstract: Hydrogen (H) and carbon (C) have probably been delivered to the Earth mainly during accretion processes at High Temperature (HT) and High Pressure (HP) and at variable redox conditions. We performed HP (1-15?GPa) and HT (1600-2300°C) experiments, combined with state-of-the-art analytical techniques to better understand the behavior of H and C during planetary differentiation processes. We show that increasing pressure makes H slightly siderophile and slightly decreases the highly siderophile nature of C. This implies that the capacity of a growing core to retain significant amounts of H or C is mainly controlled by the size of the planet: small planetary bodies may retain C in their cores while H may have rather been lost in space; larger bodies may store both H and C in their cores. During the Earth's differentiation, both C and H might be sequestrated in the core. However, the H content of the core would remain one or two orders of magnitude lower than that of C since the (H/C)core ratio might range between 0.04 and 0.27.
DS201112-0957
2011
SifySifyModi seeks sops for Gujaratis to buy diamond mines globally.Sify.com, Jan. 7, 1/4p.IndiaNews item - Gujaratis
DS201012-0564
2010
Siga, O.Passarelli, C.R., Basei, M.A.S., Wemmer, K., Siga, O., Oyhantcabal, P.Major shear zones of southern Brazil and Uruguay: escape tectonics in the eastern border of Rio de la Plat a and Parananpanema cratons during West GondwanaInternational Journal of Earth Sciences, in press available,South America, Brazil, UruguayGondwana agglutination
DS201112-0770
2011
Siga, O.Passarelli, C.R., Basei, M.A.S., Wemmer,K., Siga, O., Oyhantcabal, P.Major shear zones of southern Brazil and Uruguay: escape tectonics in the eastern border of Rio de la Plat a and Paranapanema cratons during w. Gondwana amal.International Journal of Earth Sciences, Vol. 100, 2, pp. 391-414.South America, Brazil, UruguayTectonics - amalgamation
DS1991-1583
1991
Sigalovakaya, Yu.I.Sigalovakaya, Yu.I., Truskinovskiy, L.M., Urusov, V.S.Comparison of quasichemical and regular disordering models for minerals with melilite type structuresGeochemistry International, Vol. 28, No. 4, pp. 109-117RussiaMelilite, Geochemistry
DS1989-1391
1989
Sigalovskaya, Yu. I.Sigalovskaya, Yu. I., Truskinovskiy, L.M., Urusov, V.S.Short range forces in mineral disordering melilite type structuresGeochemistry International, Vol. 26, No. 2, February pp. 16-27RussiaMineral thermometry, Melilite
DS1984-0665
1984
Sigalovskaya, YU.I.Sigalovskaya, YU.I., Sandomirskiy, P.A., Urosov, V.S.Crystallochemistry of MelilititeMineral. Zhur., Vol. 6, No. 2, PP. 3-16.RussiaMelilitite
DS1984-0666
1984
Sigalovskaya, YU.I.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
DS1989-1392
1989
Sigalovskaya, Yu.I.Sigalovskaya, Yu.I., Truskinovskiy, L.M., Urusov, V.S.Short range forces in mineral disordering: mellilite type structuresGeochemistry International, Vol. 26, No. 2, pp. 16-26RussiaMelillite, Mineralogy
DS202009-1638
2020
Sigh, A.P.Kumar, N., Sigh, A.P., Tiwari, V.M.Gravity anomalies, isostasy and density structure of the Indian continental lithosphere.Episodes, Vol. 43, 1, pp. 609-621.Indiageophysics, gravity

Abstract: Gravity anomalies across the Indian region depict most of the geological and tectonic domains of the Indian continental lithosphere, which evolved through Archean cratonic nucleation, Proterozoic accretion, Phanerozoic India-Eurasia plate convergence, and modification through many thermal perturbations and rifting. Integrated analysis of gravity and geoid anomalies together with topographic and heat flow data led to deciphering the mechanism of isostatic compensation of topographic and geological loads, lithospheric structure, and composition. This study discusses the nature of gravity (free-air, Bouguer and Isostatic) and geoid anomalies in relation to the topography, geology, and tectonics, and presents a lithospheric density model across the peninsular India and Himalaya. Southern peninsular Indian region shows relatively low Bouguer gravity anomalies compared to the northern region. The mobile belts are generally observed to have relatively higher Bouguer gravity anomalies, e.g., Eastern Ghats Mobile Belt compared to the shield regions. The gravity lows are observed over topographic features like the Western Ghats and Himalaya, while some of the topographic highs like Aravalli show positive gravity anomaly. The Indian Ocean Geoid Low varies from -82 m over Dharwar Craton to -98 m over the Southern Granulite Terrain and finally reaches a significant low of -106 m in the Indian Ocean. Flexural isostatic compensation with variable Effective Elastic Thickness (EET) ~10 km to 50 km prevails over the stable continental region. The lithospheric thickness varies from 80 km along the coastal region to 120-130 km beneath the Saurashtra Plateau, the Southern Granulite Terrain, and the Eastern Indian Shield, and reaches to more than 200 km under the Himalayan orogenic belt in the north. From Dharwar Craton to Bundelkhand Craton in central India, the lithospheric thickness varies between 160 and 180 km.
DS200912-0759
2009
Sigloch, K.Tian, Y., Sigloch, K., Nolet, G.Multiple frequency tomography of the western US upper mantle.Geophysical Journal International, Vol. 178, 3, pp. 1384-1402.MantleGeophysics, seismics
DS200912-0760
2009
Sigloch, K.Tian, Y., Sigloch, K., Nolet, G.Multiple frequency SH wave tomography of the western US upper mantle.Geophysical Journal International, Vol. 178, bo. 3 Sept. oo, 1384-1402.United StatesTomography - not specific to diamonds
DS201112-1045
2011
Sigloch, K.Tien, Y., Zhou, Y., Sigloch, K., Nolet, G., Lake, G.Structure of North American mantle constrained by simultaneous inversion of multiple frequency SH, SS and Love waves.Journal of Geophysical Research, Vol. 116, B2, B02307..MantleGeophysics - seismics
DS201212-0655
2012
Sigloch, K.Sigloch, K.Mantle provinces under North America from multifrequency P wave tomography.Geochemistry, Geophysics, Geosystems: G3, Vol. 12MantleTomography
DS201808-1752
2018
Sigloch, K.Hosseini, K., Mathews, K.J., Sigloch, K., Shephard, G.E., Domeier, M., Tsekhmistrenko, M.SubMachine: web based tools for exploring seismic tomography and other models of Earth's deep interior.Geochemistry, Geophysics, Geosystems, Vol. 19, 5, pp. 1464-1483.Mantlegeophysics - seismic

Abstract: SubMachine is a collection of web-based tools for the interactive visualisation, analysis, and quantitative comparison of global-scale, volumetric (3-D) data sets of the subsurface, with supporting tools for interacting with other, complementary models and data sets as listed below. In short, SubMachine is a computational engine (Machine) to visualize models and datasets of the sub-surface (Sub).
DS200812-0716
2008
Sigmarsson, O.Martin, E., Martin, H., Sigmarsson, O.Could Iceland be a modern analogue for the Earth's early continental crust?Terra Nova, Vol. 20, no. 6, pp. 463-468.Europe, IcelandMantle
DS2003-0112
2003
Sigmond, E.M.Bingen, B., Nordgulen, O., Sigmond, E.M., Tucker, R., Mansfeld, J., Hogdahl, K.Relations between 1.19 - 1.13 Ga continental magmatism, sedimentation andPrecambrian Research, Vol. 124, 2-4, pp. 215-241.NorwayBlank
DS200412-0155
2003
Sigmond, E.M.Bingen, B., Nordgulen, O., Sigmond, E.M., Tucker, R., Mansfeld, J., Hogdahl, K.Relations between 1.19 - 1.13 Ga continental magmatism, sedimentation and metamorphism, Sveconorwegian province, S. Norway.Precambrian Research, Vol. 124, 2-4, pp. 215-241.Europe, NorwayMagmatism
DS2002-0158
2002
Sigmond, E.M.O.Bingen, B., Mansfeld, J., Sigmond, E.M.O., Stein, H.Baltica - Laurentia link during the Mesoproterozoic: 1.27 Ga development of continental basins in the Sveconorwegian Orogen, southern Norway.Canadian Journal of Earth Science, Vol. 39, 9, Sept.pp. 1425-40.NorwayTectonics, Geochronology
DS1994-1598
1994
Sigmund, J.Sigmund, J., Keller, J.Amphibole and garnet bearing mantle xenoliths in the Kaiserstuhl: relation to diatreme and carbonatiteMineralogical Magazine, Vol. 58A, pp. 840-841. AbstractGermanyXenoliths, Carbonatite
DS200812-1065
2008
Sigmundsen, F.Sigmundsen, F., Soemundsson, K.Iceland: a window on North Atlantic divergent plate tectonics and geologic processes.Episodes, Vol. 31, 4, pp. 92-97.Europe, IcelandTectonics
DS200512-0983
2006
Sigmundson, F.Sigmundson, F.Iceland geodynamics.Springer, ISBN 3-540-24165-5 300p. $ 169. springeronline.comEurope, IcelandBook - plumes, volcanology
DS200612-1299
2006
Sigmundson, F.Sigmundson, F.Magma does the splits.Nature, Vol. 442, 7100, July 20, p. 251.MantleMagmatism
DS200412-0432
2004
Sigmundsson, F.De Zeeuw van Dalfsen, E., Pedersen, R., Sigmundsson, F., Pagli, C.Satellite radar interferometry 1993-1999 suggest deep accumulation of magma near the crust mantle boundary at the Krafla volcaniGeophysical Research Letters, Vol.31, 13, July 16, 10.1029/2004 GL020059Europe, IcelandGeophysics - boundary
DS1987-0680
1987
Sigolo, J.B.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
DS2000-0894
2000
Sigurdson, I.A.Sigurdson, I.A., Steinthorsson, S., Gronvold, K.Calcium rich melt inclusions in chromium spinels from Borgarhraun, northern Iceland.Earth and Planetary Science Letters, Vol.183, No.1-2, Nov.30, pp.15-26.GlobalMineral chemistry - chromium spinels
DS1991-1644
1991
Sigurdsson, H.Sparks, R.S.J., Carey, S.N., Sigurdsson, H.Sedimentation from gravity currents generated by turbulent plumesSedimentology, Vol. 38, pp. 839-856GlobalSedimentation -plumes, Gravity currents
DS1999-0668
1999
Sigurdsson, H.Sigurdsson, H.Melting the earth: the history of ideas on volcanic eruptionsOxford University of Press., 260p. ISBN 0-19-510665-2. $ 30.00GlobalBook - volcanology, Melting
DS201809-2061
2018
Sigurdsson, H.Liu, J., Pearson, D.G., Shu, Q., Sigurdsson, H.Hafnium osmium isotope systematics of mantle peridotites from the Cameroon Volcanic Line: implications for dating post-Archean lithospheric mantle.Goldschmidt Conference, 1p. AbstractMantleperidotites

Abstract: The Re-Os isotope system is well suited to constraining the timing of melt depletion of Archean mantle peridotites. In contrast, the variability inherent in post-Archean mantle Os isotope evolution leads to increasing uncertainty in Re-Os model ages. The Lu-Hf isotopic system has shown some potential for dating peridotite formation ages, providing valuable ages that are complementary to the Re-Os system. For post-Archean mantle peridotites, the key target in the Lu-Hf isotopic work is clinopyroxene (Cpx), because of its high Lu and Hf concentrations and the typical absence of garnet in these rocks. However, orthopyroxene (Opx) can contrain 20% or more of the Hf budget of spinel peridotites and somethimes over 40% of the Lu budget, with Lu/Hf ratios 3-4 times those of Cpx. Thus, Opx Lu-Hf isotopic compositions cannot be ignored or simply calculated, as the equilibrium temperatures of mantle peridotites prior to eruption could be lower or higher than the Hf closure temperature (Tc(Hf)~900ºC). Here we explore Lu-Hf partitioning in spinel peridotite xenoliths from the Cameroon Volcanic Line in additin to WR Re-Os analyses. The Hf isotopic composition of Opx in these rocks is equal to or higher than that of Cpx, consistent with some samples having equilibrium temperatures close to Tc(Hf). Combining Cpx and Opx, the constructed WR Lu-Hf isochron yields an age of 2.01±0.36 Ga (2s; MSWD = 11.4; ?Hfi = -0.8±19.2), which is in accordance with the oldest of the variable Re-Os model ages. The continental sector of the Cameroon Line runs close to the edge of the Congo craton. The Hf-Os data indicate that the lithosphere underpinning this region formed in the Paleoproterozoic (~2Ga) most likely during the Paleoproterzoic assembly between the Congo and West African Cratons. We emphasize that Opx and Cpx should be combined together to construct the WR isochron in order to obtain the precise age and initial Hf isotope compositions of post-Archean spinel peridotites.
DS201911-2541
2019
Sigurdsson, H.Liu, J., Pearson, D.G., Shu, Q., Sigurdsson, H., Thomassot, E., Alard, O.Dating the post-Archean lithospheric mantle: insights from Re-Os and Lu-Hf isotopic systematics of the Cameroon volcanic line peridotites.Geochimica et Cosmochimica Acta, in press available. 13p.Africa, Cameroonperidotite

Abstract: Highly depleted Archean peridotites have proven very amenable to Re-Os model age dating. In contrast, due to the increasing heterogeneity of mantle Os isotope compositions with time, the Re-Os system has not been as effective in dating post-Archean peridotites. The timing of depletion and accretion of post-Archean lithospheric mantle around cratons is important to understand within the context of the evolution of the continents. In an attempt to precisely date post-Archean peridotite xenoliths, we present a study of the petrology, mineralogy and geochemistry, including whole-rock Re-Os isotopes, highly siderophile elements and clinopyroxene-orthopyroxene Sr-Nd-Hf isotopes of peridotite xenoliths from Lake Nyos in the Cameroon Volcanic Line (CVL). Eight Nyos peridotite xenoliths, all fresh spinel lherzolites, are characterized by low to moderate olivine Fo contents (88.9-91.2) and low spinel Cr# (8.4-19.3), together with moderate to high whole-rock Al2O3 contents (2.0-3.7%). These chemical characteristics indicate that they are mantle residues of a few percent to <20% partial melting. However, trace element patterns of both clinopyroxene and orthopyroxene are not a pristine reflection of melt depletion but instead show various extents of evidence of metasomatic enrichment. Some of the samples contain orthopyroxene with 143Nd/144Nd lower than its coexisting clinopyroxene, which is best explained by recent short-timescale alteration, most likely by infiltration of the host basalt. Because of these metasomatic effects, the Sr-Nd isotope systematics in pyroxenes cannot sufficiently reflect melt depletion signatures. Unlike Sr-Nd isotopes, the Lu-Hf isotope system is less sensitive to recent metasomatic overprinting. Given that orthopyroxene hosts up to 33% of the Lu and 14% of the Hf in the whole rock budget of these rocks and has 176Hf/177Hf similar to, or higher than, coexisting clinopyroxene, it is necessary to reconstruct a whole-rock Lu-Hf isochron in order to constrain the melt depletion age of peridotites. The reconstructed Nyos Lu-Hf isochron from ortho- and clinopyroxenes gives an age of 2.01?±?0.18?Ga (1s), and when olivine and spinel are considered, is 1.82?±?0.14?Ga (1s). Both ages are identical within error, and they are within error of the alumina-187Os/188Os pseudo-isochron ages (1.2-2.4?Ga) produced on the peridotites from Lake Nyos, consistent with their oldest rhenium depletion Os model ages (2.0?Ga). We conclude that the Nyos peridotites, and the lithospheric mantle that they represent, were formed at ~2.0?Ga, indicating that the reconstructed whole-rock Lu-Hf isotope system can be a powerful radiometric dating tool that is complementary to and in some instances, more precise than the Re-Os isotope system in dating well-preserved post-Archean peridotites. The recognition of ~2.0?Ga subcontinental lithospheric mantle (SCLM) in the Nyos area suggests that the Nyos region was assembled as a Paleoproterozoic block, or that it represents fragments of the SCLM from the nearby Paleoproterozoic domain juxtaposed through collisional emplacement during the Pan African Orogeny. With regards to the origin of the CVL, our data reveal that the Hf isotopic compositions of the Nyos peridotites are too radiogenic to be the main source of the CVL basalts.
DS202006-0932
2020
Sigurdsson, H.Liu, J., Pearson, D.G., Shu, Q., Sigurdsson, H., Thomassot, E., Alard, O.Dating post-Archean lithospheric mantle: insights from Re-Os and Lu-Hf isotopic systematics of the Cameroon volcanic line peridotites.Geochimica et Cosmochimica Acta, Vol. 278, pp. 177-198.Africa, Cameroonperidotites

Abstract: Highly depleted Archean peridotites have proven very amenable to Re-Os model age dating. In contrast, due to the increasing heterogeneity of mantle Os isotope compositions with time, the Re-Os system has not been as effective in dating post-Archean peridotites. The timing of depletion and accretion of post-Archean lithospheric mantle around cratons is important to understand within the context of the evolution of the continents. In an attempt to precisely date post-Archean peridotite xenoliths, we present a study of the petrology, mineralogy and geochemistry, including whole-rock Re-Os isotopes, highly siderophile elements and clinopyroxene-orthopyroxene Sr-Nd-Hf isotopes of peridotite xenoliths from Lake Nyos in the Cameroon Volcanic Line (CVL). Eight Nyos peridotite xenoliths, all fresh spinel lherzolites, are characterized by low to moderate olivine Fo contents (88.9-91.2) and low spinel Cr# (8.4-19.3), together with moderate to high whole-rock Al2O3 contents (2.0-3.7%). These chemical characteristics indicate that they are mantle residues of a few percent to <20% partial melting. However, trace element patterns of both clinopyroxene and orthopyroxene are not a pristine reflection of melt depletion but instead show various extents of evidence of metasomatic enrichment. Some of the samples contain orthopyroxene with 143Nd/144Nd lower than its coexisting clinopyroxene, which is best explained by recent short-timescale alteration, most likely by infiltration of the host basalt. Because of these metasomatic effects, the Sr-Nd isotope systematics in pyroxenes cannot sufficiently reflect melt depletion signatures. Unlike Sr-Nd isotopes, the Lu-Hf isotope system is less sensitive to recent metasomatic overprinting. Given that orthopyroxene hosts up to 33% of the Lu and 14% of the Hf in the whole rock budget of these rocks and has 176Hf/177Hf similar to, or higher than, coexisting clinopyroxene, it is necessary to reconstruct a whole-rock Lu-Hf isochron in order to constrain the melt depletion age of peridotites. The reconstructed Nyos Lu-Hf isochron from ortho- and clinopyroxenes gives an age of 2.01?±?0.18?Ga (1s), and when olivine and spinel are considered, is 1.82?±?0.14?Ga (1s). Both ages are identical within error, and they are within error of the alumina-187Os/188Os pseudo-isochron ages (1.2-2.4?Ga) produced on the peridotites from Lake Nyos, consistent with their oldest rhenium depletion Os model ages (2.0?Ga). We conclude that the Nyos peridotites, and the lithospheric mantle that they represent, were formed at ~2.0?Ga, indicating that the reconstructed whole-rock Lu-Hf isotope system can be a powerful radiometric dating tool that is complementary to and in some instances, more precise than the Re-Os isotope system in dating well-preserved post-Archean peridotites. The recognition of ~2.0?Ga subcontinental lithospheric mantle (SCLM) in the Nyos area suggests that the Nyos region was assembled as a Paleoproterozoic block, or that it represents fragments of the SCLM from the nearby Paleoproterozoic domain juxtaposed through collisional emplacement during the Pan African Orogeny. With regards to the origin of the CVL, our data reveal that the Hf isotopic compositions of the Nyos peridotites are too radiogenic to be the main source of the CVL basalts.
DS201809-2016
2018
SihengDuan, Yunfei, Sun, Ningyu, Wang, Siheng, Li, Xinyang, Guo, Xuan, Ni.Phase stability and thermal equation of state of delta -AIOOH: implication for water transportation in the deep lower mantle.Earth and Planetary Science Letters, Vol. 494, 1, pp. 92-98.Mantlewater

Abstract: In this study, we present new experimental constraints on the phase stability and thermal equation of state of an important hydrous phase, d-AlOOH, using synchrotron X-ray diffraction up to 142 GPa and 2500 K. Our experimental results have shown that d-AlOOH remains stable at the whole mantle pressure-temperature conditions above the D? layer yet will decompose at the core-mantle boundary because of a dramatic increase in temperature from the silicate mantle to the metallic outer core. At the bottom transition zone and top lower mantle, the formation of d-AlOOH by the decomposition of phase Egg is associated with a ~2.1-2.5% increase in density (?) and a ~19.7-20.4% increase in bulk sound velocity (VF). The increase in ? across the phase Egg to d-AlOOH phase transition can facilitate the subduction of d-AlOOH to the lower mantle. Compared to major lower-mantle phases, d-AlOOH has the lowest ? but greatest VF, leading to an anomalous low ? /VF ratio which can help to identify the potential presence of d-AlOOH in the region. More importantly, water released from the breakdown of d-AlOOH at the core-mantle boundary could lower the solidus of the pyrolitic mantle to cause partial melting and/or react with Fe in the region to form the low-velocity FeO2Hx phase. The presence of partial melting and/or the accumulation of FeO2Hx phase at the CMB could be the cause for the ultra-low velocity zone. d-AlOOH is thus an important phase to transport water to the lowermost mantle and helps to understand the origin of the ultra-low velocity zone.
DS201112-0812
2011
SiidraPolyakova, E.A., Chakhmouradian, A.R., Siidra ,Britvin, Petrov, Spratt, Williams, Stanley, ZaitsevFluorine, yttrium and lanthanide rich cerianite from carbonatitic rocks of the Kerimasi volcano and surrounding explosion craters, Gregory Rift.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterAfrica, TanzaniaCarbonatite
DS201112-0958
2011
Siidra, O.I.Siidra, O.I., Spratt, J., Demeny, A., Homonnay, Z., Markl, G., Zaitsev, A.N.Cation distribution in the crystal structure of a new amphibole group mineral from the Deeti volcanic cone, northern Tanzania.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterAfrica, TanzaniaAlkalic
DS1991-1376
1991
Siims, P.K.Pratt, W.P., Siims, P.K.The Midcontinent of the United States -permissive terrane for an Olympic Dam type depositUnited States Geological Survey (USGS) Bulletin, No. 1932, 81pMissouriOlympic DaM., Copper-uraniuM.
DS1995-1748
1995
Sikka, D.B.Sikka, D.B.Mineral potential of IndiaProspectors and Developers Association of Canada (PDAC) Reprint, 10pIndiaEconomics, Mineral resources
DS1989-0980
1989
Sikorsky, R.McCrank, G.F.D., Kamineni, D.C., Ejeckam, R.B., Sikorsky, R.Geology of the East Bulletin Lake gabbro- anorthosite pluton, Algoma OntarioCanadian Journal of Earth Sciences, Vol. 26, No. 2, February pp. 357-375OntarioAnorthosite
DS201605-0912
2016
Sikwa, N.A.Van Niekerk, L.M., Oliver, A., Armstrong, J., Sikwa, N.A.Pioneering large diamond recovery at Karowe diamond mineDiamonds Still Sparkling SAIMM 2016 Conference, Mar. 14-17, pp. 15-26.Africa, BotswanaDeposit - Karowe
DS201709-2069
2016
Sikwa, N.A.Van Niekirk, L.M., Olivier, A., Armstrong, J., Sikwa, N.A.Pioneering large diamond recovery at Karowe diamond mine.South African Institute of Mining and Metallurgy, Vol. 116, 8, pp. 709-714.Africa, Botswanadeposit - Karowe

Abstract: Historically, the recovery of large diamonds in conventional treatment plant flow sheets has been associated with dense media separation (DMS). This is attributed mainly to DMS's highly efficient and proven track record in the concentration and separation of ores with variable solids densities. In most instances, DMS has been utilized as a pre-concentration step ahead of any recovery plant, due to its ability and versatility in reducing feed within a specific size range to manageable volumes for downstream X-ray processing and subsequent diamond recovery. The benefit of using carbon-signature-based detection equipment for retrieving large stones upfront in the flow sheet not only equates to earlier recovery of diamonds from the system, but also lessens the exposure of diamond-bearing ore to additional materials handling, pumping, and/or crushing, which has been known to damage or even break diamonds and decrease revenue.
DS200812-0890
2008
Silaev, V.A.I.A.Petrovsky, V.A.A.A., Silaev, V.A.I.A., Martins, M.A., Karfunkel, J.A., Sukharev, A.A.E.A.Nanoscale mineral inclusions in the diamond phase of carbonados.Doklady Earth Sciences, Vol. 421, 2, pp. 889-892.TechnologyDiamond inclusions
DS200412-1818
2004
Silaev, V.I.Silaev, V.I., Chaikovskii, I.I., Rakin, V.I., Filippov, Y.N.A new type of synthetic xenomineral inclusions in diamond.Doklady Earth Sciences, Vol. 394, 1, Jan-Feb. pp. 53-57.RussiaDiamond inclusions
DS200712-0987
2006
Silaev, V.I.Silaev, V.I., Petrovsky, V.A., Sukharev, A.E., Filippov, V.N.Inclusions of zircon based solid solutions in diamonds.Doklady Earth Sciences, Vol. 411, no. 8, pp. 1318-RussiaDiamond inclusions
DS200812-0888
2008
Silaev, V.I.Petrovsky, V.A., Silaev, V.I., Sukharev, A.E., Shamina, S.N., Martins, M., Karfunkel, J.Fluid phases in carbonado and their generic significance.Geochemistry International, Vol. 46, 7, pp. 693-710.TechnologyCarbonado
DS200912-0694
2006
Silaev, V.I.Silaev, V.I., Petrovsky, V.A., Sukharev, A.E., Filippov, V.N.Inclusions of zircon based solid solutions in diamond.Doklady Earth Sciences, Vol. 411 no. 8, pp. 1318-1323.TechnologyDiamond inclusiosn
DS201012-0582
2009
Silaev, V.I.Petrovsky, V.A., Silaev, V.I., Sukharev, A.E., Shanina, S.N., Martins, M., Karfunkel, J.Fluid phases in carbonado and their genetic significance.Geochemistry International, Vol. 47, 7, July, pp. 693-710.TechnologyCarbonado
DS201012-0768
2010
Silaev, V.I.Sukharev, A.E., Petrovsky, V.A., Silaev, V.I., Martins, M.Solid inclusions in carbonados.International Mineralogical Association meeting August Budapest, abstract p. 186.TechnologyCarbonado
DS201412-0683
2014
Silaev, V.I.Petrovsky, V.A., Silaev, V.I., Sukharev, A.E., Vasilyev, E.A., Pomazansky, B.S., Zemnukhov, A.L.Yakutites: mineralogical geochemical properties and new version of the genesis. Part 1.Izvestiya VUZ'ov Geologia I Razvedka ** in Russia Courtesy of Felix, No. 3, pp. 24-33.Russia, YakutiaCarbonado, with lonsdaleite
DS201412-0825
2014
Silaev, V.I.Silaev, V.I., Petrovsky, V.A., Sukharev, A.E., Smoleva, I.V., Pomazansky, B.S., Zemnukhov, A.L.Yakutites: mineralogical geochemical properties and new version of the genesis. Part 2.Izvestiya VUZ'ov Geologia I Razvedka ** in Russia Courtesy of Felix, No. 4, pp. 12-22.TechnologyYakutites
DS201605-0883
2015
Silaev, V.I.Petrovsky, V.A., Silaev, V.I., Sukharev, A.E., Golubeva, I.I., Rakin, V.I., Lutoev, V.P., Vasiliev, E.A.Placer forming Diamondiferous rocks and diamonds of Eastern Brazil. IN RUSS Eng. Abs.Thesis, Vestnik Permskogo Universitecta IN RUSS, Vol. 1, 30, pp. 33-59.South America, BrazilAlluvials
DS2000-0068
2000
Silantyev, S.A.Bazlev, B.A., Silantyev, S.A.Geodynamic interpretation of the subsolidus recrystallization of mantle spinel peridotites...pt.2Petrology, Vol. 8, No. 3, pp. 201-13.GlobalPeridotites - Mid Ocean Ridge Basalt (MORB).
DS2000-0069
2000
Silantyev, S.A.Bazylev, B.A., Silantyev, S.A.Geodynamic interpretation of the subsolidus recrystallization of mantle spiPetrology, Vol. 8, No. 4, July-Aug. pp. 311-331.MantleOphiolites, Xenoliths
DS2003-1273
2003
Silantyev, S.A.Silantyev, S.A.Variations in the geochemical and isotopic characteristics of residual peridotites alongPetrology, Vol. 11, 4, pp. 305-26.Mid-Atlantic RidgeGeochronology
DS200412-1819
2003
Silantyev, S.A.Silantyev, S.A.Variations in the geochemical and isotopic characteristics of residual peridotites along the mid-Altantic Ridge as a function ofPetrology, Vol. 11, 4, pp. 305-26.Mid-Atlantic RidgeGeochronology
DS200412-1820
2004
Silantyev, S.A.Silantyev, S.A., Bazylev, B.A., Dosso, L., Karpenko, S.F., Belyatskii, B.V.Relation between plume magmatism and mantle metasomatism beneath the Mid-Atlantic Ridge: petrological and geochemical evidence iPetrology, Vol.l2, 1, pp. 1-16.MantleMetasomatism
DS201912-2836
2019
Silber, R.A.Yong, W., Secco, R.A., Littleton, J.A.H., Silber, R.A., Reynaold, E.The iron invariance: implications for thermal convection in Earth's core.Geophysical Research Letters, Vol. 46, 20, pp. 11065-110670.Mantlegeothermometry

Abstract: Earth's magnetic field is produced by a dynamo in the core that requires motion of the fluid Fe alloy. Both thermal convection, arising from the transport of heat in excess of conducted heat, and compositional convection, arising from light element exsolution at the freezing inner core boundary, are suggested as energy sources. The contribution of thermal convection (possibly ranging from nothing to significant) depends on thermal conductivity of the outer core. Our experimental measurements of electrical resistivity of solid and liquid Fe at high pressures show that resistivity is constant along the pressure-dependent melting boundary of Fe. Using our derived thermal conductivity value at the inner core (freezing) boundary, we calculate the heat conducted in the liquid outer core and find that thermal convection is needed to carry additional heat through the outer core to match the heat extracted through the core-mantle boundary.
DS200412-1821
2004
Silberfein, M.Silberfein, M.The geopolitics of conflict and diamonds in Sierra Leone.Geopolitics, Frank Cass Publ. Taylor &, Francis Group., Vol. 9, no. 1, March pp. 213-249.Africa, Sierra LeoneNews - politics
DS1992-1404
1992
Silberling, N.J.Silberling, N.J., Jones, D.L., Monger, J.W., Coney, P.J.Lithotectonic terrane map of the North American CordilleraUnited States Geological Survey (USGS) Map, No. I 2176 1- 80 miles $ 6.25GlobalLithotectonic map, Cordillera, Terranes
DS202002-0221
2020
Sildos, I.Yelisseyev, A., Gromilov, S., Afanasiev, V., Sildos, I., Kiisk, V.Effect of lonsdaleite on the optical properties of impact diamonds.Diamonds & Related Materials, Vol. 101, 107640, 13p. PdfRussiaPopigai

Abstract: The special features of impact diamonds are the orientation of the nanosized grains relative to each other, the presence of hexagonal diamond (lonsdaleite, L) in a large part of the samples and the increased wear resistance. Using Raman spectroscopy and XRD, two groups of translucent samples of Popigai impact diamonds (PIDs) were selected: with and without lonsdaleite and the effect of lonsdaleite on the optical properties of the samples was studied. In all L-containing PIDs there is a strong absorption band of about 1230 cm-1 in the one-phonon region, in the mid-IR. The absorption edge is blurred and described by the Urbach rule. The estimated value of Eg ~4 eV for L is consistent with the first principles calculations. Impurity nitrogen is found only in L-free PIDs: There are signals from nitrogen-vacancy complexes in the photoluminescence (PL) spectra. Variations in the number of nitrogen atoms (N = 1 to 4) in the structure of these centers indicate significant variations in the parameters of PID annealing. L-containing PIDs are characterized by large strains in the lattice and, as a consequence, there are problems with the defect diffusion. The narrow lines in PL spectra, uncommon for diamond, can be the result of several orders of magnitude higher concentrations of impurities in PIDs formed during the solid-phase transition. The broadened peaks of 180, 278 and 383 K are distinguishable in the curves of thermostimulated luminescence (TSL) for L-free PIDs, but in the presence of L the TSL glow becomes continuous as in natural IaA-type diamonds with platelets. In general, lonsdaleite deteriorates the optical properties of impact diamonds and makes it difficult to create certain types of impurity-vacancy complexes for different applications.
DS1993-0058
1993
Sileny, J.Babuska, V., Plomerova, J., Sileny, J.Models of seismic anisotropy in the deep continental lithospherePhysics of the Earth and Planetary Interiors, Vol. 78, pp. 167-191MantleGeophysics -seismics, Tectonics, Structure
DS1990-0449
1990
Silfer, J.A.Engel, M.H., Macko, S.A., Silfer, J.A.Carbon isotope composition of individual amino acidss in the MurchisonmeteoriteNature, Vol. 348, No. November 1, pp. 47-49GlobalMeteorite, Geochronology -CI
DS1993-0655
1993
Silferstolpe, A.Hermann, G., Silferstolpe, A.Namibian mining industry - role and prospectsRaw Materials Report, Vol. 9, No. 4, pp. 2-19.NamibiaMining Industry, Economics
DS200412-1822
2004
Silic, J.Silic, J.Exploration of Ashton's Alberta kimberlites with time domain EM.PDAC 2004, 1p. abtract.Canada, AlbertaGeophysics
DS1960-0742
1966
Silin, YU. I.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
DS201809-2043
2018
Siljestrom, S.Ivarsson, M., Skogby, H., Bengtson, S., Siljestrom, S., Ounchanum, P., Boonsoong, A., Kruachanta, M., Marone, F., Belivanova, V., Holstrom, S.Intricate tunnels in garnets from soils and river sediments in Thailand - possible endolithic microborings.PluS One, Vol. 13, 8, doi:10.1371/journal.pone.0200351Asia, Thailandgarnets

Abstract: Garnets from disparate geographical environments and origins such as oxidized soils and river sediments in Thailand host intricate systems of microsized tunnels that significantly decrease the quality and value of the garnets as gems. The origin of such tunneling has previously been attributed to abiotic processes. Here we present physical and chemical remains of endolithic microorganisms within the tunnels and discuss a probable biological origin of the tunnels. Extensive investigations with synchrotron-radiation X-ray tomographic microscopy (SRXTM) reveal morphological indications of biogenicity that further support a euendolithic interpretation. We suggest that the production of the tunnels was initiated by a combination of abiotic and biological processes, and that at later stages biological processes came to dominate. In environments such as river sediments and oxidized soils garnets are among the few remaining sources of bio-available Fe2+, thus it is likely that microbially mediated boring of the garnets has trophic reasons. Whatever the reason for garnet boring, the tunnel system represents a new endolithic habitat in a hard silicate mineral otherwise known to be resistant to abrasion and chemical attack.
DS1860-1101
1899
Sillard, R.M.Sillard, R.M.Where the Diamonds Come FromEnglish Illustrated Magazine., Vol. 20, P. 647.Africa, South AfricaHistory
DS1859-0032
1823
Silliman, B.Silliman, B.Experiments upon Diamond, Anthracite and Plumbago with the Compound Blow pipe, in a Letter Addressed to Prof. Robert Hare.American Journal of Science, Vol. 6, PP. 349-353, APRIL 15TH.GlobalDiamond Morphology
DS1860-0053
1867
Silliman, B. JR.Silliman, B. JR.Notice of New Localities of Diamonds in CaliforniaCalifornia Academy of Science Proceedings, Vol. 3, PP. 354-355.United States, CaliforniaDiamond Occurrence
DS1860-0054
1867
Silliman, B. JR.Silliman, B. JR.On New Localities of Diamonds in CaliforniaAmerican Journal of Science, 2ND. SER., Vol. 44, P. 119.United States, CaliforniaDiamond Occurrence
DS1860-0216
1873
Silliman, B. JR.Silliman, B. JR.Mineralogical Notes on Utah, California, and NevadaEngineering and Mining Journal, Vol. 17, P. 148, MARCH 11. ALSO: American Journal of Science, 3RD. SER.United States, California, Utah, NevadaMineralogy
DS1860-0217
1873
Silliman, B. JR.Silliman, B. JR.On the Probable Existence of Microscopic Diamonds with Zircons and Topaz in the Sands of Hydraulic Washings in California.American Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Transactions, Vol. 1, PP. 371-373.United States, CaliforniaAlluvial Placers
DS2002-1482
2002
Sillitoe, R.H.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
DS1982-0198
1982
Sills, J.D.Exley, R.A., Sills, J.D., Smith, J.V.Geochemistry of Micas from the Finero Spinel Lherzolite Italian AlpsContributions to Mineralogy and Petrology, Vol. 81, No. 1, pp. 59-63ItalyLherzolite
DS200412-1823
2004
Sills, M.N.Sills, M.N.Corporate conduct and security of tenure in 'weak governance zones'.An update on legal issues and developments in the mining industry, PDAC and Natural Resource and Energy Law (O, March 10, 14p. ppt slidesAfrica, Democratic Republic of CongoLegal - overview, example
DS1998-1152
1998
SilvaPereira, R.S., Wheelock, G., Bizzi, L., Silva, LeiteAlluvial diamond potential of Paleo drainage systems in the headwaters Of the Sao Francisco River, Minas Gerais7th. Kimberlite Conference abstract, pp. 684-6.Brazil, Minas GeraisAlluvials, Deposit - Sao Francisco
DS2000-0196
2000
SilvaCunha, 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
DS201112-1026
2011
SilvaTallaire, A., Barjon, J., Brinza, O., Achard, Silva, Mille, Issaoui, Tardieu, GicquelDislocations and impurities introduced from etch-pitts at the epitaxial growth resumption of diamond.Diamond and Related Materials, Vol. 20, 7, pp. 875-881.TechnologyDiamond morphology
DS201906-1334
2019
Silva, A.C.Pereira, L., Birtel, S., Mockel, R., Michaux, B., Silva, A.C.Constraining the economic potential of by-product recovery by using a geometallurgical approach: the example of rare earth element recovery at Catalao 1, Brazil.Economic Geology, Apr. 15. abstractSouth America, Brazildeposit - Catalao 1

Abstract: Geometallurgy aims to develop and deploy predictive spatial models based on tangible and quantitative resource characteristics that are used to optimize the efficiency of minerals beneficiation and extractive metallurgy operations. Whilst most current applications of geometallurgy are focused on the major commodity to be recovered from a mineral deposit, this contribution delineates the opportunity to use a geometallurgical approach to provide an early assessment of the economic potential of by-product recovery from an ongoing mining operation. As a case study for this methodology possible REE-recovery as a by-product of Nb-production at the Catalão I carbonatite complex, the Chapadão mine is used. Catalão I is part of the Alto Paranaíba Igneous Province in the Goias Province of Brazil. Nowadays, niobium is produced in the complex as a by-product of the Chapadão phosphates mine. This production is performed on the Tailings plant, the focus of this study. Rare earth elements, albeit present in significant concentrations, are currently not recovered as by-products. Nine samples from different stages of the Nb beneficiation process in the Tailings plant were taken and characterized by Mineral Liberation Analyzer, X-ray powder diffraction, and bulk rock chemistry. The recovery of rare earth elements in each of the tailing streams was quantified by mass balance. The quantitative mineralogical and microstructural data are used to identify the most suitable approach to recover REE as a by-product-without placing limitations on niobium production. Monazite, the most common rare earth mineral identified in the feed, occurs as Ce-rich and La-rich varieties that can be easily distinguished by SEM-based image analysis. Quartz, FeTi-oxides and several phosphate minerals are the main gangue minerals. The highest rare earth oxide content concentrations (1.75 wt.% TREO) and the greatest potential for REE processing are reported for the final flotation tailings stream. To place tentative economic constraints on REE recovery from the tailings material, an analogy to the Browns Range deposit in Australia is drawn. Its technical flow sheet was used to estimate the cost for a hypothetical REE-production at Chapadão. Parameters derived from SEM-based image analysis were used to model possible monazite recovery and concentrate grades. This exercise illustrates that a marketable REE concentrate could be obtained at Chapadão if the process recovers at least 53 % of the particles with no less than 60% of monazite on their surface. Applying CAPEX and OPEX values similar to that of Browns Range suggest that such an operation would be profitable at current REE prices.
DS1994-0579
1994
Silva, A.J.C.C.Gaspar, J.C., Silva, A.J.C.C., Dearaujo, D.P.Composition of priderite in phlogopites from the Catalao I carbonatitecomplex, Brasil.Mineralogical Magazine, Vol. 58, No. 392, Sept. 409-415.BrazilCarbonatite
DS201112-0959
2011
Silva, D.Silva, D., Lana, C., Stevens, G., Souza Filho, C.R.Effects of shock induced incongruent melting within Earth's crust: the case of biotite melting.Terra Nova, in press availableMantleMelting
DS201907-1565
2019
Silva, D.Oliveira, E.P., Talavera, C., Windley, B.F., Zhao, L., Semprich, J.J., McNaughton, N.J., Amaral, W.S., Sombini, G., Navarro, M., Silva, D.Mesoarchean ( 2820 Ma )high pressure mafic granulite at Uaus, Sao Francisco craton, Brazil, and its potential significance for the assembly of Archean supercraton.Precambrian Research, Vol. 331, 105266 20p.South America, Brazilcraton
DS200612-0845
2006
Silva, D.C.C.Macambira, M.J.B., Armstrong, R.A., Silva, D.C.C., Camelo, J.F.The Archean Paleoproterozoic boundary in Amazonian Craton: new isotope evidence for crustal growth.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 2, abstract only.South America, BrazilGeochronology, craton
DS201412-0826
2014
Silva, G.M.Silva, G.M., Endo, I., Ribeiro, F.Analise magnetometrica de possiveis pipes kimberlitocos no distrito diamantifero do Abaete, MG> 6 Simposio Brasileiro de Geologia do Diamante, Aug. 3-7, 2p. AbstractSouth America, Brazil, Minas GeraisGeophysics
DS2000-0361
2000
Silva, L.C.Gresse, P.G., Silva, L.C., et al.The Neoproterozoic orogenic systems of western Gondwana in southern Africa and southern Brasil.Igc 30th. Brasil, Aug. abstract only 1p.Brazil, South AfricaGeodynamics - tectnics, Gondwanaland
DS200712-0272
2007
Silva, L.C.Doucelance, R., Mata, J., Moreira, M., Silva, L.C.Isotope evidence for the origin of Cape Verde oceanic carbonatites.Plates, Plumes, and Paradigms, 1p. abstract p. A233.Europe, Cape Verde IslandsCarbonatite, geochronology
DS201012-0475
2010
Silva, L.C.Mata, J., Moreira, M., Doucelance, R., Ader, M., Silva, L.C.Noble gas and carbon isotopic signatures of Cape Verde oceanic carbonatites: implications for carbon provenance.Earth and Planetary Science Letters, Vol. 291, 1-4, pp. 70-83.Europe, Cape Verde IslandsCarbonatite
DS201012-0519
2009
Silva, L.C.Mourai, C., Mata, J., Doucelance, R., Madeira, J., Brum da Silviera, A., Silva, L.C., Moreira, M.Quaternary extrusive calciocarbonatite volcanism on Brava Island ( Cape Verde): a nephelinite carbonatite immiscibility product.Journal of African Earth Sciences, Vol. 56, 2-3, pp. 59-74.Europe, Cape Verde IslandsCarbonatite
DS1999-0669
1999
Silva, L.J.H.D.Silva, L.J.H.D.Basin infilling in the southern-central part of the Sergipano Belt: evolution of Pan-African Brasiliano..Journal of African Earth Sciences, Vol. 12, No. 5, Sept. pp. 453-70.Brazil, northeastCraton, Tectonics
DS1992-1569
1992
Silva, M.E.Trompette, R., Uhlein, A., Silva, M.E., Karmann, I.The Brasiliano Sao Francisco Craton revisited (central Brasil)Journal of South American Earth Science, Vol. 6, No. 1-2, pp. 49-57BrazilCraton, Proterozoic fold belt
DS200612-0050
2006
Silva, M.E.Assumpcao, M., Heintz, M., Vauchez, A., Silva, M.E.Upper mantle anisotropy in SE and Central Brazil from SKS splitting: evidence of asthenospheric flow around a cratonic keel.Earth and Planetary Science Letters, Vol.250, 1-2, pp. 224-240.South America, BrazilGeophysics - seismics
DS1995-1749
1995
Silva, N.M.Silva, N.M.Mineralogy and geology of the Poco Verde kimberlite, Coromandel MG Brasil.(in Portugese).Msc. Thesis, University Of Sao Paulo, (in Portugese)., Brazil, Minas GeraisKimberlite, Deposit -Poco Verde
DS201112-0123
2010
Silveira, F.V.Bueono Sachs, L.L., Silveira, F.V.Kimberlitos do estado do Piaui.5th Brasilian Symposium on Diamond Geology, Nov. 6-12, abstract p. 70-71.South America, Brazil, Minas GeraisOverview of area
DS201112-0201
2011
Silveira, F.V.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
DS201112-0960
2010
Silveira, F.V.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
DS201212-0018
2012
Silveira, F.V.Araujo, D.P., Silveira, F.V., Weska, R.K., Rachid, F., Neto, F.E.B., Ireland, T., Holden, P., Gobbo, L.Diamonds from the Sao Francisco and Amazon cratons, Brazil.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractSouth America, BrazilDeposit - Andari, Lencois, Barra do Mendes, Catalao, Frutal
DS201212-0656
2012
Silveira, F.V.Silveira, F.V., Britto, R.S., Matos, L., Araujo, D.P.Diamante Brasil project.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractSouth America, BrazilDeposit - Coromandel, Diamantina
DS201412-0156
2014
Silveira, F.V.Cunha, L.M, Neto, I.C.,Silveira, F.V.As intrusoes kimberliticas Santa Fe-01 E Arabia-01 provincia Borborema, nordeste do Brasil.6 Simposio Brasileiro de Geologia do Diamante, Aug. 3-7, 1p. AbstractSouth America, BrazilDeposit - Arabia -01, Santa Fe-01
DS201412-0157
2014
Silveira, F.V.Cunha, L.M., Silveira, F.V., Bezerra Neto, F.E.Caracterizacao petrografiz e estudos dos minerais indicadores provenientas da intrusao kimberlitica Braz-01 provincia alto Paranaiba, MG.6 Simposio Brasileiro de Geologia do Diamante, Aug. 3-7, 3p. AbstractSouth America, Brazil, Minas GeraisDeposit - Braz -01
DS201412-0621
2014
Silveira, F.V.Neto, I.C., Castro, C.C., Silveira, F.V., Cunha, L.M., Weska, R.K., Dousa, W.S.Intrusos kimberliticas de Rondonia: uma sintese com base no conhecimento atual.6 Simposio Brasileiro de Geologia do Diamante, Aug. 3-7, 6p. AbstractSouth America, BrazilRondonia area
DS201412-0728
2014
Silveira, F.V.Rego, F.M., Cunha, L.M., Silveira, F.V., Borges, W.R.Caracterizacao geoleltrica de aluvioes diamantiferos no Rio Santo Inacio - Coromandel, M.G.6 Simposio Brasileiro de Geologia do Diamante, Aug. 3-7, 4p. AbstractSouth America, Brazil, Minas GeraisCoromandel geophysics
DS201412-0827
2014
Silveira, F.V.Silveira, F.V., Cunha, L.M., Neto, I.C.Diamante Brasil project. 6 Simposio Brasileiro de Geologia do Diamante, Aug. 3-7, 1p. AbstractSouth America, BrazilDatabase
DS201412-0974
2014
Silveira, F.V.Weska, R.K., Cabral Neto, I., Silveira, F.V.Fontes primarias e secundariaras do diamante, Morro do Chapadao, Juina, MT. Brasil.6 Simposio Brasileiro de Geologia do Diamante, Aug. 3-7, 1p. AbstractSouth America, Brazil, Mato GrossoDeposit - Juina
DS201602-0228
2015
Silveira, F.V.Neto, I.C., Cunha, L.M., Silveira, F.V., Nannini, F., de Oliveira, R.G., deSouza, W.S., Bezerra, A.K.Discovery and confirmation of the first kimberlitic intrusion in the Bororema Province, NE Brazil.CPRM, Informe Technico in Port ( abstract in english), No. 2, Nov. 7p.South America, BrazilDeposit - Santa Fe-1,2
DS200612-1300
2006
Silveira, M.P.Silveira, M.P.National sustainable development strategies: moving from theory to practice.Natural Resources Forum, Vol. 30, 2, May pp. 86-89.GlobalEnvironment
DS2001-0325
2001
SilverFouch, M.J., James, Silver, VanDecar, Van der LeeImaging broad ranges in structural variations beneath the Kaapvaal and Zimbabwe Cratons, southern Africa.Slave-Kaapvaal Workshop, Sept. Ottawa, 5p. abstractSouth Africa, ZimbabweGeophysics - seismics, Tomography - Kimberley array
DS1996-1306
1996
Silver, C.S.Silver, C.S., Rothman, D.S.Toxics and health - the potential long term effects of industrialactivityWorld Resources Institute, 60p. approx. $ 15.00United StatesBook - ad, Environment - health
DS1996-1307
1996
Silver, D.Silver, D.Society for Mining, Metallurgy and Exploration (SME) stock exchange - it could happen... comments on letter from previous column on concerns as to status .Mining Engineering, Vol. 48, No. 7, July p. 10, 17United StatesEconomics, Exploration activities and needs
DS1994-1599
1994
Silver, D.B.Silver, D.B.1992 mineral exploration statistics -USA and Canadian companiesEconomic Geology, Vol. 89, No. 4, June-July pp. 960-967United States, CanadaEconomics, Exploration expenditures, costs
DS1996-1308
1996
Silver, D.B.Silver, D.B.Fair market value Vs. collateral valueMining Engineering, Vol. 48, No. 5, May pp. 10-11GlobalGeostatistics, Ore reserves
DS1996-1309
1996
Silver, D.B.Silver, D.B.Isn't industry's purpose to create value?Mining Engineering, Vol. 48, No. 1, Jan. pp. 12-13United StatesEconomics
DS1998-1346
1998
Silver, D.B.Silver, D.B.Why global death spirals need miningMining Eng, Vol. 50, No. 10, Oct. pp. 13-14GlobalEconomics, Discoveries, success
DS1998-1347
1998
Silver, D.B.Silver, D.B.Is the mining industry consolidating or expandingMining Engineering, Vol. 50, No. 5, May p. 11United StatesEconomics, discoveries, Success
DS2002-1483
2002
Silver, D.B.Silver, D.B.Unraveling the mysteries of mining transactionsFifth Joint Advanced Business Valuation Conference American Society of, Oct. 24-26, Orlando, Fla. 32p.United StatesEconomics - valuation, Standards, types of properties
DS1991-1584
1991
Silver, L.Silver, L.Growth, modification and destruction of continental lithosphere as reworked in southwestern North AmericaEos, Spring Meeting Program And Abstracts, Vol. 72, No. 17, April 23, p. 297United StatesCrust, Mantle
DS1960-0096
1960
Silver, L.T.Silver, L.T.Age Determinations on Precambrian Diabase Differentiates In the Sierra Ancha, Gila County, Arizona.Geological Society of America (GSA) Bulletin., Vol. 71, PP. 1973-1974.GlobalKimberlite, Rocky Mountains, Colorado Plateau
DS1960-1025
1968
Silver, L.T.Silver, L.T.Precambrian Batholiths of ArizonaGeological Society of America (GSA) SPECIAL PAPER., No. 121, PP. 558-559.GlobalKimberlite, Colorado Plateau, Rocky Mountains
DS1970-0137
1970
Silver, L.T.Mcgetchin, T.R., Silver, L.T.Compositional Relations in Minerals from Kimberlite and Related Rocks in the Moses Rock Dike San Juan County Utah.American Mineralogist., Vol. 55, SEPT. -Oct. PP. 1738-1771.United States, Utah, Colorado Plateau, Rocky MountainsPetrography, Mineral Chemistry, Inclusions
DS1970-0138
1970
Silver, L.T.Mcgetchin, T.R., Silver, L.T., Chodos, A.A.Titanoclinohumite: a Possible Mineralogical Site for Water In the Upper Mantle.Journal of Geophysical Research, Vol. 75, PP. 255-259.Colorado PlateauKimberlite, Rocky Mountains
DS1970-0139
1970
Silver, L.T.Mcgetchin, T.R., Silver, L.T., Chodos, A.A.Mineral Inclusions in Pyropes from Colorado Plateau Kimberlite Pipes.Eos, Vol. 51, No. 4, P. 448. (abstract.).United States, Colorado PlateauBlank
DS1970-0557
1972
Silver, L.T.Mcgetchin, T.R., Silver, L.T.A Crustal Upper Mantle Model for the Colorado Plateau Based on Observations of Crystalline Rock Fragments in the Moses Rock Dike.Journal of Geophysical Research, Vol. 77, No. 35, Dec. 19TH. PP. 7022-7037.United States, Utah, Colorado Plateau, Rocky MountainsPetrography, Xenoliths
DS1975-0408
1976
Silver, L.T.Silver, L.T.A Regional Uranium Anomaly in the Precambrian Basement of The Colorado Plateau.Geological Society of America (GSA), Vol. 8, No. 6, PP. 1107-1108, (abstract.).Colorado PlateauKimberlite, Rocky Mountains
DS1992-0301
1992
Silver, L.T.Cordani, U., McLaren, D.J., Silver, L.T., Skinner, B.J., WolmanThe H-F boundary: who needs a bolide?Gsa Today, Vol. 2, No. 5, May p. 99GlobalHolocene Future Boundary, Conference
DS1994-1600
1994
Silver, L.T.Silver, L.T., McGetchin, T.R.Observations on the nature of the Precambrian crust under the southern Colorado Plateau.Geological Society of America Abstracts, Vol. 26, No. 6, April p. 63. Abstract.ColoradoXenoliths
DS1998-0732
1998
Silver, P.Kendall, M., Silver, P.Mechanisms for seismic anisotropy in the lowermost mantleMineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 761-2.MantleAnisotropy - D boundary layer, Discontinuity
DS2001-1076
2001
Silver, P.Silver, P., Gao, S.Anisotropic and discontinuity structure beneath southern AfricaSlave-Kaapvaal Workshop, Sept. Ottawa, 1p. abstractSouth AfricaGeophysics - seismics
DS2001-1199
2001
Silver, P.Ven der Lee, S., James, D., Silver, P.Upper mantle S velocity structure of central and south AmericaJournal of Geophysical Research, Vol. 106, No. 12, pp. 30,821-34.South AmericaTectonics, Geophysics
DS2001-1226
2001
Silver, P.Wen. L., Silver, P., James, D., Kuehnel, R.Seismic evidence for a thermo chemical boundary at the base of the Earth'smantle.Earth and Planetary Science Letters, Vol. 189, No. 3-4, July 15, pp. 141-54.MantleGeophysics - seismics, Boundary
DS200712-0988
2007
Silver, P.Silver, P.Riding the Wilson cycle: the theory of plate tectonics continues to evolve. Now new research is answering some of the most exciting lingering questions ....Geotimes, Vol. 52, 7, pp. 30-33.MantleTectonics - evolution of continents
DS201412-0828
1999
Silver, P.Silver, P., et al.Mantle structural geology from seismic anisotropy.Geochemical Society Special Publication No. 6, Mantle Petrology, No. 6, pp.MantleGeophysics - seismic
DS201112-0455
2011
Silver, P.A.Hu, S., Silver, P.A., Wolfe, A.P.Palynology and age of post-eruptive lake sediments from the Wombat kimberlite locality, Northwest Territories, Canada.Geological Society of America, Annual Meeting, Minneapolis, Oct. 9-12, abstractCanada, Northwest TerritoriesGeochronology
DS201712-2722
2017
Silver, P.A.Reyes, A.V., Wolfe, A.P., Tierney, J.E., Silver, P.A., Royer, D.L., Greenwood, D.R., Buryak, S., Davies, J.H.F.L.Paleoenvironmental research on early Cenozoic sediment fills in Lac de Gras kimberlite pipes: progress and prospects.45th. Annual Yellowknife Geoscience Forum, p. 65 abstractCanada, Northwest Territoriesdeposit - Giraffe

Abstract: Several Lac de Gras kimberlite pipes host thick accumulations of stratified post-eruptive lacustrine sediment and peat. Given the range of Lac de Gras kimberlite emplacement ages, these fills - though rare - provide a unique sedimentary archive of paleoenvironments during the sustained Early Cenozoic “greenhouse” interval, in a high-latitude region otherwise devoid of Phanerozoic sediment cover. Extensive exploration drilling has provided a valuable window into this unique sedimentary record, which would have otherwise remained covered by Quaternary glacial deposits. Our focus to date has been multidisciplinary study of the Giraffe pipe sediment fill: an ~80 m-thick sequence of post-eruptive lacustrine silt overlain by peat, which paints a remarkable picture of a humid-temperate Middle Eocene forest ecosystem on the Canadian Shield. Post-eruptive chronology is provided by interbedded distal tephra horizons, likely sourced from Alaska, that have been dated by glass fission-track and zircon U-Pb techniques. Paleoclimate proxies derived from pollen, wood cellulose oxygen isotopes, and biomarkers converge on reconstructed mean annual temperatures >17 °C warmer than present, with mean winter temperatures above freezing, and mean annual precipitation ~4x present. Two independent reconstructions of CO2 from well preserved conifer foliage suggest that this warming occurred under relatively modest atmospheric CO2 concentrations of 430-630 ppm. These findings provide direct field-based evidence for dramatic past arctic warming at CO2 concentrations that were well within the range of projections under “business-as-usual” emissions scenarios, underscoring the capacity for exceptional polar amplification of climate change under modest CO2 concentrations once both fast and slow feedbacks processes become expressed. Our studies at Giraffe pipe also highlight the scientific value of archived exploration drill core in the Lac de Gras kimberlite field, particularly with respect to pipes that are unremarkable for the purpose of diamond exploration.
DS1990-1136
1990
Silver, P.G.Olson, P., Silver, P.G., Carlson, R.W.The large scale structure of convection in the earth's mantleNature, Vol. 344, No. 6263, March 15, pp. 209-214GlobalMantle, Tectonics/structure
DS1992-0139
1992
Silver, P.G.Bokelmann, G.H.R., Silver, P.G.Mantle variation within the Canadian ShieldEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p. 204Wyoming, OntarioCraton, Structure
DS1993-0957
1993
Silver, P.G.Mainprice, D., Silver, P.G.Interpretation of SKS -waves using samples from the subcontinentallithosphere.Physics of the Earth and Planetary Interiors, Special issue on Dynamics of, Vol. 78, No. 3-4, July pp. 257-280.MantleGeophysics -seismics, Lithosphere, anisotropy
DS1993-1465
1993
Silver, P.G.Silver, P.G., Kaneshima, S.Constraints on mantle anisotropy beneath Precambrian North America from a transportable teleseismic experiment.Geophysical Research Letters, Vol. 20, No. 12, June 18, pp. 1127-1130.Ontario, WyomingGeophysics -seismics, Craton
DS1996-1228
1996
Silver, P.G.Russo, R.M., Silver, P.G.Cordillera formation, mantle dynamics and the Wilson cycleGeology, Vol. 24, No. 6, June pp. 511-514South America, Cordillera, Andes, BoliviaGeodynamics, Wilson Cycle
DS1996-1310
1996
Silver, P.G.Silver, P.G.Seismic anisotropy beneath the continents: probing the depths of geologyAnnual Review of Earth Planetary Sciences, Vol. 24, pp. 385-432GlobalSeismics, Review - Continents
DS1996-1311
1996
Silver, P.G.Silver, P.G.Seismic anisotropy beneath the continents -probing the depths of geologyAnnual Review Earth Science, Vol. 24, pp. 385-MantleGeophysics -seismics, Review
DS1997-0080
1997
Silver, P.G.Barruol, G., Silver, P.G., Vauchez, A.Seismic anisotropy in the eastern United States: deep structure of acomplex continental plate.Journal of Geophysical Research, Vol. 102, No. 4, April 10, pp. 8329-48.Appalachia, MidcontinentGeophysics - seismics, Tectonics
DS1998-1348
1998
Silver, P.G.Silver, P.G., Russo, R.M., Lithgow-Bertelloni, C.Coupling of South America and African plate motion and plate deformationScience, Vol. 279, No. 5347, Jan. 2, pp. 60-62South America, AfricaTectonics, Plate deformation
DS2000-0895
2000
Silver, P.G.Silver, P.G., Gao, S.S.Mantle deformation beneath southern Africa #1Geological Society of America (GSA) Abstracts, Vol. 32, No. 7, p.A-163.South AfricaCraton - evolution Kaapvaal, Zimbabwean, Geophysics - seismics
DS2001-1077
2001
Silver, P.G.Silver, P.G., Gao.S.S., Lio, K.H.Mantle deformation beneath southern Africa #2Geophysical Research Letters, Vol. 28, No. 13, July 1, pp. 2493-6.South AfricaGeophysics - seismics, Craton - evolution Kaapvaal, Zimbabwean, Kaapvaal Craton
DS2002-0185
2002
Silver, P.G.Bokelmann, G.H.R., Silver, P.G.Shear stress at the base of shield lithosphereGeophysical Research Letters, Vol. 29, 23, Dec. 01, 6p. DOI 10.1029/2002GLO15925MantleGeophysics - seismics
DS2002-0500
2002
Silver, P.G.Gao, S.S., Silver, P.G., Liu, K.H.Mantle discontinuities beneath southern AfricaGeophysical Research Letters, Vol. 29,10,May15,pp.129-South Africa, BotswanaGeophysics - seismics
DS2002-1145
2002
Silver, P.G.Niu, F., Solomon, S.C., Silver, P.G., Suetsugu, InoueMantle transition zone structure beneath the South Pacific Superswell, evidence for a mantle plume...Earth and Planetary Science Letters, Vol.198,3-4,pp.371-80., Vol.198,3-4,pp.371-80.South PacificTectonics, Hot spot - Society
DS2002-1146
2002
Silver, P.G.Niu, F., Solomon, S.C., Silver, P.G., Suetsugu, InoueMantle transition zone structure beneath the South Pacific Superswell, evidence for a mantle plume...Earth and Planetary Science Letters, Vol.198,3-4,pp.371-80., Vol.198,3-4,pp.371-80.South PacificTectonics, Hot spot - Society
DS2002-1484
2002
Silver, P.G.Silver, P.G., Holt. W.E.The mantle flow field beneath western North AmericaScience, No. 5557, Feb. 8, pp. 1054-7.North America, CordilleraGeophysics - seismics
DS2003-0832
2003
Silver, P.G.Liu, K.H., Gao, S.S., Silver, P.G., Zhang, Y.Mantle layering across central South AmericaJournal of Geophysical Research, Vol. 108, B11, 2510 DOI. 1029/2002JB002208Brazil, South AmericaGeophysics - seismics, discontinuity, depth, Nazca, sub
DS200412-0125
2004
Silver, P.G.Behn, M.D., Conrad, C.P., Silver, P.G.Detection of upper mantle flow associated with the African superplume.Earth and Planetary Science Letters, Vol. 224, 3-4, pp. 259-274.Africa, South AfricaGeophysics - seismics, boundary, mantle convection
DS200412-0568
2004
Silver, P.G.Fouch, M.J., Silver, P.G., Lee, J.N.Small scale variations in seismic anisotropy near Kimberley, South Africa.Geophysical Journal International, Vol. 157, 2, pp. 764-774.Africa, South AfricaGeophysics - seismics
DS200412-1159
2003
Silver, P.G.Liu, K.H.,Gao, S.S., Silver, P.G., Zhang, Y.Mantle layering across central South America.Journal of Geophysical Research, Vol. 108, B11, ESE 9 10.1029/2003 JB002208South America, MantleGeophysics - seismics
DS200412-1824
2004
Silver, P.G.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
DS200612-0964
2006
Silver, P.G.Nair, S.K., Gao, S.S., Liu, K.H., Silver, P.G.Southern African crustal evolution and composition: constraints from receiver function system.Journal Geophysical Research, Vol. 111, B2, Feb. 17, B02304Africa, South AfricaGeophysics - seismics
DS200612-1301
2006
Silver, P.G.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
DS200712-0198
2007
Silver, P.G.Conrad, C.P., Behn, M.D., Silver, P.G.Global mantle flow and the development of seismic anisotropy; differences between the oceanic and continental upper mantle.Journal of Geophysical Research, Vol. 112, B7 B07317.MantleGeophysics - seismics
DS200712-0199
2007
Silver, P.G.Conrad, C.P., Behn, M.D., Silver, P.G.Global mantle flow and the development of seismic anisotropy: difference between the oceanic continental upper mantle.Journal of Geophysical Research, Vol. 112, B7, B07317.MantleGeophysics - seismics
DS200712-0989
2006
Silver, P.G.Silver, P.G., Hahn, B.C., Kreemer, C., Holt, W.E., Haines, J.Convergent margins, growing and shrinking continents, and the Wilson cycle.Geological Society of America Annual Meeting, Vol. 38, 7, Nov. p. 212 abstractUnited StatesBasin and Range, Wilson Cycle
DS200812-0686
2008
Silver, P.G.Long, M.D., Silver, P.G.The subduction zone flow field from seismic anisotropy: a global view.Science, Vol. 319, Jan. 18, pp. 315-318.MantleSubduction
DS200812-1008
2008
Silver, P.G.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
DS200812-1066
2008
Silver, P.G.Silver, P.G., Behn, M.D.Intermittent plate tectonics?Science, Vol. 319, 5859, Jan. 04, pp. 85-87.MantleTectonics
DS200912-0452
2009
Silver, P.G.Long, M.D., Silver, P.G.Mantle flow in subduction systems: the subslab flow field and implications for mantle dynamics.Journal of Geophysical Research, Vol. 114, B10, B10312MantleSubduction
DS1860-0254
1875
Silver, S.W.Silver, S.W.Handbook for South Africa; Including the Cape Colony, Natal, the Diamond Fields and the Trans-Orange Republics.London:, 495P. ALSO:BRITISH Association Advanced Science, No. 4922, P. 319.Africa, South Africa, Griqualand WestGuidebook
DS1860-0716
1891
Silver, S.W.and Co.Silver, S.W.and Co.Handbook of South Africa, Including the Cape Colony, the DiaLondon:, 793P. FOURTH EDITION.Africa, South Africa, Botswana, Zimbabwe, Central Africa RepublicGuidebook
DS1985-0072
1985
Silvera, I.F.Boppart, H., Van straaten, J., Silvera, I.F.Raman Spectra of Diamond at High PressuresPhysical Review B: Condensed Matter., Vol. 32, No. 2, JULY 15TH. PP. 1423-1425.GlobalBlank
DS201112-0961
2011
Silversmit, G.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
Silversmit, G.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
Silversmit, G.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
DS1975-0619
1977
Silvestre, J.P.Silvestre, J.P.Presence of a Lherzolite Dyke in the Calcareous Range of The Luberon, Vaucluse, France.Comptes Rendus Hebdomadaires Des Seances De L'academie Des S, Vol. 285, No. 5, PP. 495-496.GlobalBlank
DS1993-1693
1993
Silvi, B.Wang, A., Dhamelincourt, P., Silvi, B.A high pressure-T structural form of chromite found as inclusions in diamondGeological Society of America Annual Abstract Volume, Vol. 25, No. 6, p. A217 abstract onlyGlobalDiamond inclusion, Chromite
DS200612-1302
2006
Sim, B.L.Sim, B.L., Agterberg, F.P.A conceptual model for kimberlite emplacement by solitary interfacial mega-waves on the core mantle boundary.Journal of Geodynamics, Vol. 41, 5, July, pp. 451-461.MantleConvection, magnetics, D layer Rogue waves ULVZ
DS200612-1303
2006
Sim, B.L.Sim, B.L., Agterberg, F.P.A conceptual model for kimberlite emplacement by solitary interfacial megawaves on the core mantle boundary.Journal of Geodynamics, Vol. 41, 5, pp. 451-461.MantleGeophysics
DS201710-2260
2017
Sim, L.A.Rebetsky, Yu.L., Sim, L.A., Kozyrev, A.A.Possible mechanism of horizontal overpressure generation of the Khibiny, Lovozero, and Kovdor ore clusters on the Kola Peninsula.Geology of Ore Deposits, Vol. 59, 4, pp. 265-280.Russia, Kola Peninsuladeposit - Khibiny, Lovozero, Kovdor

Abstract: The paper discusses questions related to the generation of increasing crustal horizontal compressive stresses compared to the idea of the standard gravitational state at the elastic stage or even from the prevalence of horizontal compression over vertical stress equal to the lithostatic pressure. We consider a variant of superfluous horizontal compression related to internal lithospheric processes occurrin in the crust of orogens, shields, and plates. The vertical ascending movements caused by these motions at the sole of the crust or the lithosphere pertain to these and the concomitant exogenic processes giving rise to denudation and, in particular, to erosion of the surfaces of forming rises. The residual stresses of the gravitational stressed state at the upper crust of the Kola Peninsula have been estimated for the first time. These calculations are based on the volume of sediments that have been deposited in Arctic seas beginning from the Mesozoic. The data speak to the possible level of residual horizontal compressive stresses up to 90 MPa in near-surface crustal units. This estimate is consistent with the results of in situ measurements that have been carried out at the Mining Institute of the Kola Science Center, Russian Academy of Sciences (RAS), for over 40 years. It is possible to forecast the horizontal stress gradient based on depth using our concept on the genesis of horizontal overpressure, and this forecasting is important for studying the formation of endogenic deposits.
DS2003-1274
2003
Simakin, A.G.Simakin, A.G., Petford, N.Melt distribution during the bending of a porous, partially melted layerGeophysical Research Letters, Vol. 30, 11, 10.1029/2003GLO16949MantleMelting
DS200412-1825
2003
Simakin, A.G.Simakin, A.G., Petford, N.Melt distribution during the bending of a porous, partially melted layer.Geophysical Research Letters, Vol. 30, 11, 10.1029/2003 GLO16949MantleMelting
DS201012-0709
2009
Simakin, A.G.Simakin, A.G., Ghassemi, A.The role of magma chamber fault interaction in caldera forming eruptions.Bulletin of Volcanology, Vol. 72, 1, pp. 85-101.MantleMagmatism
DS201312-0826
2013
Simakin, A.G.Simakin, A.G.Numerical modelling of the late stage of subduction zone transference after an accretion event.Terra Nova, MantleSubduction
DS200412-0510
2004
Simakin, S.G.Egorov, K.N., Soloveva, L.V., Simakin, S.G.Megacrystalline cataclastic lherzolite from the Udachnaya pipe: mineralogy, geochemistry and genesis.Doklady Earth Sciences, Vol. 397, 5, June, pp. 698-702.Russia, YakutiaMineralogy - Udachnaya
DS200612-1335
2006
Simakin, S.G.Solovova, I.P., Girnis, A.V., Ryabchikov, I.D., Simakin, S.G.High temperature carbonatite melts and its inter relations with alkaline magmas of the Dundel'dyk complex, southeastern Pamirs.Doklady Earth Sciences, Vol. 410, no. 7 July-August, pp. 1148-51.RussiaCarbonatite
DS1995-1351
1995
SimakovNikitina, L.P., Ivanov, Sokolov, Khitova, SimakovEclogites in the mantle: T P and FO2 equilibrium conditions and depths offormation.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 396-398.Africa, Australia, Russia, SiberiaEclogites, Diamond inclusions
DS1999-0691
1999
SimakovSnyder, G.A., Taylor, Beard, Halliday, Sobolev, SimakovThe diamond bearing Mir eclogites: neodymium Strontium isotopic evidence for a possible early to Mid Proterozoic source7th International Kimberlite Conference Nixon, Vol. 2, pp. 808-15.Russia, Siberia, YakutiaDepleted mantle source with arc affinity, Mineral chemistry, geothermometry
DS1994-1601
1994
Simakov, K.V.Simakov, K.V.The evolution of geological time concepts, article oneGeol. of Pacific Ocean, Vol. 9, No. 6, pp. 1075-1095GlobalGeognosy, Time scale
DS200412-1826
2004
Simakov, S.Simakov, S., Kalmykov, A., Sorokin, L., Grebenshchikova, E.Chaoite synthesis at lower temperatures and pressures.Lithos, ABSTRACTS only, Vol. 73, p. S102. abstractTechnologyDiamond like carbon phase
DS201112-0962
2010
Simakov, S.Simakov, S.Computer program PTQuick for the calculation of the P-T-fO2 parameters of the mantle and upper crust kimberlite and lamproite parageneses.simakov @ap1250.spb.edu, St. Petersburg UniversityTechnologyHe will send an overview zip file on request
DS1983-0577
1983
Simakov, S.K.Simakov, S.K.Evaluation of the Diamond Content of Deep Seated Rocks (kimberlites) Based on the Calculation of Free Energy of the Diamond Dissolution Iron Containing Melt.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 271, No. 2, PP. 443-446.RussiaDiamond Genesis
DS1984-0667
1984
Simakov, S.K.Simakov, S.K.Probable genesis of metastable diamond from fluids in continental crustconditions.(Russian)Doklady Academy of Sciences Nauk SSR, (Russian), Vol.278, No. 4, pp. 953-957RussiaDiamond, Genesis
DS1984-0668
1984
Simakov, S.K.Simakov, S.K.The Possibility of Diamond Metastable Formation from Fluid sunder Conditions of Earth Crust.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 278, No. 4, PP. 953-957.RussiaGenesis
DS1984-0669
1984
Simakov, S.K.Simakov, S.K.Formation and Crystallization of Diamond from Fluid in Mantle Melts.Doklady Academy of Science USSR, Earth Science Section., Vol. 266, No. 1-6, MAY PP. 166-169.RussiaGenesis, Diamond Morphology
DS1984-0670
1984
Simakov, S.K.Simakov, S.K.Calculation of Possible Metastable Formation in Earth's CrustDoklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 278, pp. 953-957RussiaRef. Fleischer United States Geological Survey (usgs) Of 88-689.mineralogical Refs. 198
DS1984-0671
1984
Simakov, S.K.Simakov, S.K.Estimation of Diamond Content of Plutonic Rocks (kimberlites) by Calculating the Free Energy of Solution of Diamond in Iron Containing Melt.Doklady Academy of Science USSR, Earth Science Section., Vol. 271, No. 1-6, PP. 183-186.Russia, South AfricaDiamond Content Calculation, Diamond Genesis
DS1985-0616
1985
Simakov, S.K.Simakov, S.K.Estimation of diamond content of plutonic rocks (kimberlites) by calculating the free energy of solution of diamond i iron containing meltDoklady Academy of Science USSR, Earth Science Section, Vol. 271, No. 1-6, January pp. 183-187RussiaDiamond Morphology, Diamond Content
DS1986-0737
1986
Simakov, S.K.Simakov, S.K.Possible production of metastable diamond from fluids in the crust #2Doklady Academy of Science USSR, Earth Science Section, Vol. 278, No. 1-6, pp. 122-130RussiaDiamond genesis
DS1986-0738
1986
Simakov, S.K.Simakov, S.K.Possible production of metastable diamond from fluids in the crust #1Doklady Academy of Science USSR, Earth Science Section, Vol. 278, No. 1-6, April, pp. 127-130RussiaExperimental mineralogy
DS1987-0681
1987
Simakov, S.K.Simakov, S.K.Diamond formation in the processes of the kimberlite magmaevolution.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 293, No.3, pp. 681-684RussiaGenesis
DS1988-0064
1988
Simakov, S.K.Blinova, G.K., Gurkina, G.A., Simakov, S.K.Some chemical properties of the medium from which natural diamondscrystallizeDoklady Academy of Science USSR, Earth Science Section, Vol. 301, No. 4, July-Aug, pp. 207-209RussiaDiamond morphology, Crystallography
DS1988-0637
1988
Simakov, S.K.Simakov, S.K.Generation of diamond during the evolution of kimberlitic magmasDoklady Academy of Science USSR, Earth Science Section, Vol. 293, No. 1-6, September pp. 139-142RussiaDiamond genesis, Magma
DS1988-0638
1988
Simakov, S.K.Simakov, S.K.Generation and recrystallization of diamonds in the upper mantleDoklady Academy of Science USSR, Earth Science Section, Vol. 301, No. 4, July-Aug, pp. 157-160RussiaDiamond morphology, Crystallography
DS1991-1585
1991
Simakov, S.K.Simakov, S.K., Bagdasarov, E.A., Lukyanov, L.I.Mineralogical features of alkaline-ultrabasic lamprophyres and Kimberlites of Kolsky Province.(Russian)Doklady Academy of Sciences Nauk SSR, (Russian), Vol. 320, No. 4, pp. 971-976RussiaKimberlites, Kolsky
DS1992-1405
1992
Simakov, S.K.Simakov, S.K., Vaganov, V.I.New petrological criteria for preliminary estimation of diamond content of deep mantle rocks.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 323, No. 3, pp. 531-534.RussiaKimberlites, Petrology
DS1993-1466
1993
Simakov, S.K.Simakov, S.K., Bagdasarov, E.A., Lukyanova, L.I.Mineralogy of alkalic ultramafic lamprophyres and kimberlites from the KolaProvince.Doklady Academy of Sciences USSR, Earth Science Section, Vol. 321, No. 8, August 1993, pp. 176-182.Russia, Commonwealth of Independent States (CIS), KolaMineralogy, Kimberlites
DS1994-1602
1994
Simakov, S.K.Simakov, S.K.Mineralogical and petrological features of alkali ultramafic lamprophyres and kimberlites of Kola (Russian)Russian Mineralogical Society Proceedings, No. 1, pp. 26-40.Russia, Kola PeninsulaMineralogy, Lamprophyres, kimberlites
DS1994-1603
1994
Simakov, S.K.Simakov, S.K.Diamondiferous dependence of deepest lherzolites with spinel from initial oxygen-hydrogen environment. (Russian)Doklady Academy of Sciences Nauk., (Russian), Vol. 335, No. 1, March pp. 88-90.RussiaLherzolites, Diamonds
DS1995-0088
1995
Simakov, S.K.Bagdasarov, E.A., Lukiyanova, L.I., Simakov, S.K.Mineralogical and geochemical features of new province of alkali ultramaficlamprophyres, lamproites, kimb.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 28-30.Russia, Kola, KareliaPetrology, Deposits -Kola, Karelia
DS1995-1750
1995
Simakov, S.K.Simakov, S.K.A garnet - clinopyroxene fugometer for mantle eclogitesDoklady Academy of Sciences USSR, Vol. 333, No. 8, August, pp. 91-93.GlobalPetrology -experimental, Eclogites
DS1995-1751
1995
Simakov, S.K.Simakov, S.K.Types of eclogite paleogeotherms in the upper mantleProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 532-534.MantleGeothermometry, Eclogites
DS1995-1752
1995
Simakov, S.K.Simakov, S.K.Diamond content of spinel bearing deep seated lherzolite xenoliths in relation to redox setting..Doklady Academy of Sciences, Vol. 337, No. 5, Dec., pp. 116-120.Russia, YakutiaXenoliths -time of formation, Kimberlites
DS1995-1753
1995
Simakov, S.K.Simakov, S.K.Thermodynamic evaluation of the effect of redox conditions on generation of diamond and graphite....Zh. Ftz. Khim. (Russian), Vol. 69, No. 2, Feb. pp. 346-347.RussiaMethane condensation, Geochemistry
DS1995-1754
1995
Simakov, S.K.Simakov, S.K., Nikitina, L.P.The relation between diamond levels in mantle xenoliths and upper mantle redox conditions.Geochemistry International, Vol. 32, No. 10, Oct. 1, pp. 46-57.MantleDiamonds, Xenoliths
DS1995-1755
1995
Simakov, S.K.Simakov, S.K., Nikitina, L.P.Relationship between potential Diamondiferous ability and oxygen reduction conditions for the upper mantle.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 535-537.MantlePetrology, Diamond genesis
DS1995-1756
1995
Simakov, S.K.Simakov, S.K., Nikitina, L.P.On the relationship of mantle xenolite diamond formation with the Upper mantle redox conditions (Russian)Geokimiya, (Russian), No. 2, Feb. pp. 163-174. # QP734RussiaXenolith, Mantle redox
DS1996-1312
1996
Simakov, S.K.Simakov, S.K.Garnet orthopyroxene olivine fugacity meter for mantle peridotiteDoklady Academy of Sciences, Vol. 339, No. 8, Jan., pp. 156-160.MantlePeridotite, Spinel, ilmenite
DS1996-1313
1996
Simakov, S.K.Simakov, S.K.Diamond formation in metamorphic crustal rocksDoklady Academy of Sciences, Vol. 343 No. 5, May pp. 182-186.Russia, Kazakhstan, ChinaMetamorphic rocks, Diamond genesis
DS1997-1042
1997
Simakov, S.K.Simakov, S.K.Garnet pyroxene geobarometer for crustal eclogite type rocksDoklady Academy of Sciences, Vol. 355A, No. 6, July-Aug. pp. 1354-5.MantleEclogite
DS1997-1043
1997
Simakov, S.K.Simakov, S.K., Ivanov, M.V.Specific features of the fluid regime of eclogite type diamond formation insubduction related processes..Doklady Academy of Sciences, Vol. 355, No. 5, Jun-July pp. 702-4.MantleEclogite, Diamond genesis
DS1998-1349
1998
Simakov, S.K.Simakov, S.K.Redox state of Earth's upper mantle peridotites under ancient cratons - its connection with diamond genesis.Geochimica et Cosmochimica Acta, Vol. 62, No. 10, May pp. 1811-20.MantleDiamond genesis, Oxygen fugacity
DS1998-1350
1998
Simakov, S.K.Simakov, S.K.Garnet clinopyroxene geobarometry of deep mantle eclogites and eclogitePaleogeotherm.7th International Kimberlite Conference Abstract, pp. 814-16.Russia, Yakutia, South Africa, AustraliaThermobarometry, Deposit - Monastery, Argyle, Roberts Victor
DS1999-0670
1999
Simakov, S.K.Simakov, S.K.Garnet clinopyroxene geobarometry of deep mantle eclogites and eclogite paleogeotherms.7th International Kimberlite Conference Nixon, Vol. 2, pp. 783-87.Russia, West Africa, Australia, South AfricaGeothermometry, Eclogites
DS2000-0896
2000
Simakov, S.K.Simakov, S.K.Clinopyroxene thermometry of mantle peridotites: implications for the evaluation of diamond potential.Doklady Academy of Sciences, Vol. 375, No. 8, Oct. Nov. pp. 1266-8.MantlePeridotites - diamonds
DS2000-0897
2000
Simakov, S.K.Simakov, S.K., Taylor, L.A.Geobarometry for mantle eclogites: solubility of Ca Tschermaks in clinopyroxene.International Geology Review, Vol. 42, pp. 534-44.Australia, South AfricaEclogites - Barometer, Deposit - Argyle, Monastery
DS2001-1078
2001
Simakov, S.K.Simakov, S.K.The clinopyroxene barometry of mantle peridotites: implications for diamond evaluation potential.Doklady Academy of Sciences, Vol. 377, No. 2, Feb-Mar. pp.201-3.MantleDiamond - genesis
DS2002-1250
2002
Simakov, S.K.Pervov, V.A., Kononova, V.A., Ilupin, I.P., Simakov, S.K.PT parameters of formation of rocks included as xenoliths in kimberlites of middle Timan.Doklady Earth Sciences, Vol. 386, 7, Sept-Oct.pp. 867-9.Russia, TimanGeochronology
DS2002-1485
2002
Simakov, S.K.Simakov, S.K.Manifestation of ultrahigh pressures during garnet clinopyroxene assemblage formation metamorphic complexDoklady, Vol.383A,3,March-April,pp. 236-8.GlobalMineralogy, Metamorphism - metamorphic complex
DS2002-1486
2002
Simakov, S.K.Simakov, S.K.Geobarometry of deep mantle eclogites18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.230.MantleXenoliths - kimberlite
DS2002-1487
2002
Simakov, S.K.Simakov, S.K.Rdeox state of upper mantle eclogite formation18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.243. (poster)MantleXenoliths - kimberlite
DS2003-1275
2003
Simakov, S.K.Simakov, S.K.Garnet clinopyroxene and clinopyroxene geobarometry of deep mantle eclogites and8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, AbstractAfrica, Russia, Yakutia, Australia, CanadaMantle petrology
DS200412-1827
2003
Simakov, S.K.Simakov, S.K.Garnet clinopyroxene and clinopyroxene geobarometry of deep mantle eclogites and peridotites.8 IKC Program, Session 6, AbstractAfrica, Russia, Yakutia, Australia, CanadaMantle petrology
DS200512-0984
2005
Simakov, S.K.Simakov, S.K.Clinopyroxene barometry of mantle eclogite xenoliths and the implications for assessment of diamond potential.Doklady Earth Sciences, Vol. 400, 1, pp. 113-115.MantleGeobarometry
DS200512-0985
2005
Simakov, S.K.Simakov, S.K.Garnet clinopyroxene and clinopyroxene barometers and P-T paths reconstruction of the Slave eclogites.GAC Annual Meeting Halifax May 15-19, Abstract 1p.Canada, Northwest TerritoriesGeobarometry
DS200512-0986
2005
Simakov, S.K.Simakov, S.K.Clinopyroxene barometry of mantle eclogite xenoliths and the implications for assessment of diamond potential.Doklady Earth Sciences, Vol. 400, 1, pp. 113-115.MantleGeobarometry - eclogites
DS200512-0987
2004
Simakov, S.K.Simakov, S.K., Kalmykov, A.E., Sorokin, L.M., Novikov, Drozdova, Yagovkina, GrebenshchikovaChaoite formation from carbon bearing fluid at low PT parameters.Doklady Earth Sciences, Vol. 399A, 9, Nov-Dec. pp. 1289-1290.Mineralogy - chaoite
DS200612-1304
2006
Simakov, S.K.Simakov, S.K.Redox state of eclogites and peridotites from sub-cratonic upper mantle and a connection with diamond genesis.Contributions to Mineralogy and Petrology, Vol. 151, 3, pp. 282-296.MantleDiamond genesis
DS200812-1067
2007
Simakov, S.K.Simakov, S.K.Garnet clinopyroxene barometry of crustal and mantle assemblages: implication for the estimation of diamond potential.Doklady Earth Sciences, Vol. 417, 8, pp. 1228-1230.MantleGeothermometry
DS200812-1068
2008
Simakov, S.K.Simakov, S.K.Garnet clinopyroxene and clinopyroxene geothermobarometry of deep mantle and crust eclogites and peridotites.Lithos, Vol. 106, 1-2, Nov. pp. 125-136.MantleGeothermometry
DS200812-1069
2008
Simakov, S.K.Simakov, S.K., Dubinchuk, V.T., Novikov, M.P., Drozdova, I.A.Formation of diamond and diamond type phases from the carbon bearing fluid at PT parameters correspondoing to processes in the Earth's crust.Doklady Earth Sciences, Vol. 421, 1, pp. 835-837.MantleDiamond genesis
DS201012-0173
2010
Simakov, S.K.Dubinchuk, V.T., Simakov, S.K., Pechnikov, V.A.Lonsdaleite in diamond bearing metamorphic rocks of the Kokchetav massif.Doklady Earth Sciences, Vol. 430, 1, pp. 40-42.RussiaUHP Mineralogy
DS201012-0710
2010
Simakov, S.K.Simakov, S.K.Metastable nonsized diamond formation from C-H-O fluid system.Journal of Materials Research, Vol. 25, 12, Dec. 5p.TechnologyDiamond morphology
DS201012-0711
2010
Simakov, S.K.Simakov, S.K.Formation of nanodiamonds in nature under low P-T parameters from fluid systems.Doklady Earth Sciences, in pressTechnologyNanodiamonds
DS201112-0963
2011
Simakov, S.K.Simakov, S.K.Nanodiamond formation in natural processes from fluid systems at low P-T parameters.Doklady Earth Sciences, Vol. 436, 1, pp. 148-151.MantleGenesis
DS201212-0657
2012
Simakov, S.K.Simakov, S.K.A new garnet thermometer for mantle peridotites and estimation of the diamond potential on its basis.Doklady Earth Sciences, Vol. 445, 2, pp. 1003-1005.TechnologyGeothermometry
DS201412-0829
2014
Simakov, S.K.Simakov, S.K.Calculation of the equilibrium C-O-H fluid for ilmenite xenocrysts and estimation of diamond potential.Doklady Earth Sciences, Vol. 458, 1, pp. 1171-1173.Russia, Africa, AngolaIlmenite
DS201803-0475
2017
Simakov, S.K.Simakov, S.K.Nano and micron sized diamond genesis in nature: an overview.Geoscience Frontiers, Vol. Pp. 1-10.Technologynanodiamonds

Abstract: There are four main types of natural diamonds and related formation processes. The first type comprises the interstellar nanodiamond particles. The second group includes crustal nano- and micron-scale diamonds associated with coals, sediments and metamorphic rocks. The third one includes nanodiamonds and microndiamonds associated with secondary alteration and replacing of mafic and ultramafic rocks. The fourth one includes macro-, micron- and nano-sized mantle diamonds which are associated with kimberlites, mantle peridotites and eclogites. Each diamond type has its specific characteristics. Nano-sized diamond particles of lowest nanometers in size crystallize from abiotic organic matter at lower pressures and temperatures in space during the stages of protoplanetary disk formation. Nano-sized diamonds are formed from organic matter at P-T exceeding conditions of catagenesis stage of lithogenesis. Micron-sized diamonds are formed from fluids at P-T exceeding supercritical water stability. Macrosized diamonds are formed from metal-carbon and silicate-carbonate melts and fluids at P-T exceeding 1150 °C and 4.5 GPa. Nitrogen and hydrocarbons play an important role in diamond formation. Their role in the formation processes increases from macro-sized to nano-sized diamond particles. Introduction of nitrogen atoms into the diamond structure leads to the stabilization of micron- and nano-sized diamonds in the field of graphite stability.
DS201804-0736
2018
Simakov, S.K.Simakov, S.K., Melnik, N.N., Vyalov, V.I.Nanodiamond formation at the lithogenesis and low-stages of regional metamorphism. DonbassDoklady Earth Sciences, Vol. 478, 2, pp. 214-218.Russiaspectroscopy

Abstract: Samples of gilsonite from Adzharia, anthraxolite and graphite of coal from Taimyr, shungite from Karelia, and anthracite from Donbass are studied using Raman spectroscopy. Peaks at 1600 cm-1, indicating the presence of nanographite, are recorded in all samples. The anthracite sample from Donbass, 1330 cm-1, corresponds to the sp3-line of carbon hybridization conforming to a nanodiamond. It is concluded that in nature diamonds can be formed at late stages of lithogenesis (catagensis, metagenesis), and for coals, it can occur at the zeolite stage of regional metamorphism of rocks, before the green schist stage.
DS201810-2377
2018
Simakov, S.K.Simakov, S.K.On the origin of large type IIa gem diamonds.Ore Geology Reviews, Vol. 102, pp. 195-203.Globaldiamond morphology

Abstract: The processes of formation of some diamond types still raise contentious issues, mainly on the origin of the largest diamond crystals recovered from kimberlites. These diamonds constitute less than 2% of worldwide resources and correspond to rare type IIa. They possess some peculiar features: (i) silicate and oxide inclusions are extremely rare, (ii) their d13C ranges from -17 to -21‰. The detailed estimation of the Premier pressure-temperature-oxygen fugacity parameters and the physic-chemical modeling of diamond growth-dissolution processes suggest that extra-large diamonds have multiple origins. Their formation may occur from lower mantle to crustal depths. Their main building-up takes place from fluids in the pegmatitic veins solidified along the contacts of kimberlite magma at a crustal depth. The model explains the main features of the largest kimberlitic diamonds, i.e. their great sizes, light d13C signatures, low nitrogen contents, high degree of resorption, absence of mantle-derived mineral inclusions and their occurrence in the form of rare isolated crystals in the host kimberlite.
DS201812-2880
2018
Simakov, S.K.Simakov, S.K.The nature of the diamond potential of "cold" paleogeotherms.Doklady Earth Sciences, Vol. 482, 2, pp. 1317-1319.Mantlegeothermometry

Abstract: It is known that the ?-? parameters of diamond-bearing kimberlite xenoliths correspond to subductive paleogeotherms lying between the 36 and 41 mW/m2 conductive models. There are some studies showing the correlation of diamond ability with oxygen fugacity and the fluid composition of mantle xenoliths.The most diamondiferous samples correspond to the water compositions of the calculated O-H-C fluid with a minimum atomic carbon content in it. From the calculations it follows that the fluid carbon atomic content increases with a temperature increase and with the pressure decreasing. The most minor C contents have the 35 mW/m2 conductive model in comparison with the 40 and 45 mW/m2 models. As a result, it is possible to conclude that the low temperature fields (less than 1100°C) of the “cold” geotherms have the highest diamondiferous ability.
DS201812-2881
2018
Simakov, S.K.Simakov, S.K.Type IIa diamond formation.Doklady Earth Sciences, Vol. 482, 2, pp. 1336-1338.Mantlediamond genesis
DS202003-0372
2020
Simakov, S.K.Yang, J., Simakov, S.K., Moe, K., Scribano, V., Lian, D., Wu, W.Comment on the Comparison of enigmatic diamonds from Tolbachik arc volcano ( Litasov 2019) also Litasov responseGondwana Research, in press availableRussiaKamchatka
DS1998-1351
1998
Simakov. S.K.Simakov. S.K.Upper mantle convection: implications from the kimberlite eclogitepalegeotherms.Doklady Academy of Sciences, ol. 358, No. 1, pp. 122-123.RussiaEcologite, Geothermometry
DS1988-0760
1988
Simamora, W.H.Williams, P.R., Johnston, C.R., Almond, R.A., Simamora, W.H.Late Cretaceous to early Tertiary structural elements of West KalimantanTectonophysics, Vol. 148, No. 3/4, May 1, pp. 279-298GlobalBlank
DS1992-1731
1992
Simandjuntak, H.R.W.Zeintek, M.L., Pardiarto, B., Simandjuntak, H.R.W., Wikrama, A.Placer and lode platinum group minerals in South Kalimantan, Indonesia:Australian Journal of Earth Sciences, Vol. 39, No. 3, Part 2, July pp. 405-418Indonesia, KalimantanAlluvials -not specific to diamonds, Ultramafics
DS1989-0191
1989
Simandjuntak, W.Burgath, K.P., Mohr, M., Simandjuntak, W.Aspects of diamond origin in southeast Kalimantan, Indonesia79th. Annual Meeting Of The Geologische Vereinigung, Mineral, p. 51-52. (abstract.)Indonesia, KalimantanDiamond genesis
DS2003-1276
2003
Simandl, G.J.Simandl, G.J.Subduction diamonds in British Columbia, Canada?Geological Association of Canada Annual Meeting, Abstract onlyBritish ColumbiaDiamond - genesis, Tectonics
DS2003-1277
2003
Simandl, G.J.Simandl, G.J.Diamond potential in British Columbia, Canada?8 Ikc Www.venuewest.com/8ikc/program.htm, Session 5, AbstractBritish ColumbiaTarget area selection, Jack, Mark diatremes, Xeno, Bonus, Ram
DS200412-1828
2003
Simandl, G.J.Simandl, G.J.Diamond potential in British Columbia, Canada?8 IKC Program, Session 5, AbstractCanada, British ColumbiaTarget area selection Jack, Mark diatremes, Xeno, Bonus, Ram
DS200412-1829
2003
Simandl, G.J.Simandl, G.J.Subduction diamonds in British Columbia, Canada?Geological Association of Canada Annual Meeting, Abstract onlyCanada, British ColumbiaDiamond - genesis Tectonics
DS200412-1830
2004
Simandl, G.J.Simandl, G.J.Concepts for diamond exploration in 'on/off' craton areas British Columbia, Canada.Lithos, Vol. 77, 1-4, Sept. pp. 749-764.Canada, British ColumbiaEclogite subduction zone model, Rodinia, tectonics
DS200512-0988
2005
Simandl, G.J.Simandl, G.J., Davis, W., Hewett, J.Precambrian basement - NE British Columbia - new Pb geochronological dat a and their significance for diamond exploration.British Columbia Mines, 2005-12, Canada, British ColumbiaGeochronology
DS200512-0989
2005
Simandl, G.J.Simandl, G.J., Ferbey, T., Levson, V.M., Demchuk, T.E., Hewett, T., Smith, I.R.,KjarsgaardHeavy mineral survey and its significance for diamond exploration, Fort Nelson area, BC.British Columbia Mines, 2005-13, Canada, British ColumbiaGeochemistry - KIM
DS200512-0990
2005
Simandl, G.J.Simandl, G.J., Ferbey, T., Levson, V.M., Demchuk, T.E., Mallory, S., Smith, L.R., Kjarsgaard, I.Kimberlite indicator minerals in the Fort Nelson area, northeastern British Columbia.British Columbia Geological Survey, Summary of Fieldwork, Paper 2005-1, pp. 325-343.Canada, British ColumbiaGeochemistry, geomorphology, glacial, KIMS
DS200612-1305
2005
Simandl, G.J.Simandl, G.J., Davis, W.Cratonic basement in northeastern British Columbia, new age dates and their significance for diamond exploration.British Columbia Geological Survey, Summary of Fieldwork, pp. 325-336.Canada, British ColumbiaGeochronology
DS200612-1306
2005
Simandl, G.J.Simandl, G.J., Ferbey, T., Levson, V.M., Robinson, N.D., Lane, R., Smith, R., Demchuk, Raudsepp, HickinKimberlite and diamond indicator minerals in northeast British Columbia, Canada - a reconnaissance survey.British Columbia Geological Survey, Geofile 2005-25, 25p.Canada, British ColumbiaGeochemistry, geochronology, Buffalo Head Terrane
DS201012-0712
2010
Simandl, G.J.Simandl, G.J.Rare metals and their importance - potential impact of the TGI-4 initiative.International Workshop Geology of Rare Metals, held Nov9-10, Victoria BC, Open file 2010-10, extended abstract pp. 1-2.GlobalAlkaline rocks, carbonatite
DS201012-0713
2010
Simandl, G.J.Simandl, G.J.Geological constraints on rare earth element resources and their availability: a non-partisan view.International Workshop Geology of Rare Metals, held Nov9-10, Victoria BC, Open file 2010-10, extended abstract pp. 7-8.TechnologyAlkaline rocks, carbonatite
DS201112-0964
2011
Simandl, G.J.Simandl, G.J., Fajber, R., Dunn, C.E.Biogeochemical footprint of the Ta and Nb bearing carbonatite Blue River area, British Columbia, Canada.Goldschmidt Conference 2011, abstract p.1877.Canada, British ColumbiaCarbonatite
DS201112-0965
2011
Simandl, G.J.Simandl, G.J., Fajber, R., Dunn, C.E., Ulry, B., Dahrouge, J.Biogeochemical exploration vectors in search of carbonatite, Blue River British Columbia.British Columbia Geological Survey, BCGS GeoFile, 2011-05.Canada, British ColumbiaCarbonatite
DS201412-0539
2014
Simandl, G.J.Mackay, D.A.R., Simandl, G.J.Geology, market and supply chain of niobium and tantalum - a review.Mineralium Deposita, Vol. 49, 8, pp. 1025-1047.GlobalNiobium
DS201412-0831
2014
Simandl, G.J.Simandl, G.J.Geology and market dependent significance of rare earth element resources.Mineralium Deposita, Vol. 49, 8, pp. 889-904.GlobalREE markets
DS201412-0832
2014
Simandl, G.J.Simandl, G.J., Paradis, S., Stone, R.S., Fajber, R., Kressall, R.D., Grattan, K., Crozier, J., Simandl, L.J.Applicablity of handheld X-ray fluroescence spectrometry in the exploration and development of carbonatite related niobium deposits: a case study of the Aley carbonatite, British Columbia, Canada.Geochemistry: Exploration, Environment, Analysis, Vol. 14, 3, pp. 211-221.Canada, British ColumbiaCarbonatite
DS201512-1917
2015
Simandl, G.J.Fajber, R., Simandl, G.J., Luck, P., Neetz, M.Biogeochemical methods to explore for carbonatites and related mineral deposits: an orientation survey, Blue River area, British Columbia, Canada.Symposium on critical and strategic materials, British Columbia Geological Survey Paper 2015-3, held Nov. 13-14, pp. 241-244.Canada, British ColumbiaCarbonatite

Abstract: Carbonatites host economic deposits of niobium (Nb), rare earth elements (REE), phosphate, baddeleyite (natural zirconia), vermiculite, and fl uorspar, and historically, supplied copper, uranium, carbonate (for cement industries) and sodalite (Pell, 1994 and Simandl, this volume). The Upper Fir carbonatite is in southeastern British Columbia, approximately 200 km north of Kamloops (Fig. 1). It is one ofmany known carbonatite occurrences in the British Columbia alkaline province, which follows the Rocky Mountain Trench and extends from the southeastern tip of British Columbia to its northern boundaries with the Yukon and Northwest Territories (Pell, 1994). The Upper Fir is a strongly deformed carbonatite with an indicated mineral resource of 48.4 million tonnes at 197 ppm of Ta2O5 and 1,610 ppm of Nb2O5, and an inferred resource of 5.4 million tonnes at 191 ppm of Ta2O5 and 1760 ppm of Nb2O5 (Kulla et al. 2013). The Nb, Ta, and vermiculite mineralization is described by Simandl et al. (2002, 2010), Chong, et al, (2012), and Chudy (2014). In this document we present the results of an orientation survey designed to determine the biogechemical signature of a typical carbonatite in the Canadian Cordillera. This survey suggests that needles and twigs of White Spruce (Picea glauca) and Subalpine Fir (Abies lasio carpa) are suitable sampling media to explore for carbonatites and carbonatite-related rare earth elements (REE), niobium (Nb), and tantalum (Ta) deposits.
DS201512-1936
2015
Simandl, G.J.Mackay, D.A.R., Simandl, G.J.Niobium and tantalum: geology, markets, and supply chains.Symposium on critical and strategic materials, British Columbia Geological Survey Paper 2015-3, held Nov. 13-14, pp. 13-22.GlobalNiobium, tantalum

Abstract: Until 2014, niobium (Nb) and tantalum (Ta) were on the critical metals list of the European Union (European Commission, 2011; 2014). Both Ta and Nb have high levels of supply chain risk and even temporary disruptions in supply could be difficult to cope with. The Ta market is subject to infl ux of ‘conflict’ columbite-tantalite concentrate, or ’Coltan,’ into the supply chain, displacing production in Australia and Canada. The growing consumer appetite for goods made of ethically sourced or ‘confl ict-free’ minerals and metals has put pressure on manufacturers of components for consumer electronics, such as smart phones, laptop computers, computer hard drives, digital cameras, GPS navigation systems, and airbag triggers to stop using Ta from ‘confl ict’ areas. Other uses of Ta include medical implants, super alloys used in jet turbine and rocket nozzle production, corrosion prevention in chemical and nuclear plants, as a sputtering target, and in optical lenses (Tantalum-Niobium International Study Center, 2015a, b). These applications make Ta economically and strategically important to industrialised countries (European Commission, 2011, 2014; Brown et al., 2012; Papp, 2012). Niobium (Nb) is primarily used in high-strength low-alloy (HSLA) steel used extensively in the oil and gas and automotive industries. Niobium is also a major component in vacuum-grade alloys used in rocket components and other aeronautic applications (Tantalum-Niobium International Study Center, 2015a, c). Demand for Nb is increasing due to greater use of Nb in steel making in China, India, and Russia (Roskill, 2013b; Mackay and Simandl, 2014). Because most primary Nb production is restricted to a single country (Brazil), security of supply is considered at risk (European Commission, 2014). New sources of supply may be developed to diversify geographic location of supply for strategic reasons (Mackay and Simandl, 2014). Herein we summarize the geology, market, and supply chains of Niobium and Tantalum metals.
DS201512-1937
2015
Simandl, G.J.Mackay, D.A.R., Simandl, G.J.,Ma, W., Gravel, J., Redfearn, M.Indicator minerals in exploration for speciality metal deposits: a QEMSCAN approach.Symposium on critical and strategic materials, British Columbia Geological Survey Paper 2015-3, held Nov. 13-14, pp. 211-218.TechnologyRare earths

Abstract: Quantitative Evaluation of Materials by Scanning electron microscopy (QEMSCAN®) was used to assess carbonatite indicator minerals in fl uvial sediments from the drainage area of the Aley carbonatite, in north-central British Columbia. QEMSCAN® is a viable method for rapid detection and characterization of carbonatite indicator minerals with minimal processing other than dry sieving. Stream sediments from directly above, and up to 11 km downstream, of the carbonatite deposit were selected for this indicator mineral study. The geology of the Aley carbonatite is described by Mäder (1986), Kressal et al. (2010), McLeish (2013), Mackay and Simandl (2014), and Chakhmouradian et al. (2015). Traditional indicator mineral exploration methods use the 0.25-2.0 mm size fraction of unconsolidated sediments (Averill, 2001, 2014; McCurdy, 2006, 2009; McClenaghan, 2011, 2014). Indicator minerals are detectable by QEMSCAN® at particle sizes smaller than those used for hand picking (<0.25 mm). Pre-concentration (typically by shaker table) is used before heavy liquid separation, isodynamic magnetic separation, optical identifi cation using a binocular microscope, and hand picking (McClenaghan, 2011). Following additional sieving, the 0.5-1 and 1-2 mm fractions are hand picked for indicator minerals while the 0.25-0.5 mm fraction is subjected to paramagnetic separation before hand picking (Averill, 2001; McClenaghan, 2011). Hand picking indicator minerals focuses on monomineralic grains, and composite grains may be lost during processing. Composite grains are diffi cult and time consuming to hand pick and characterize using optical and Scanning Electron Microscopy (SEM) methods. A single grain mount can take 6-12 hours to chemically analyse (Layton- Matthews et al., 2014). Detailed sample analysis using the QEMSCAN® Particle Mineral Analysis routine allows for 5-6 samples to be analyzed per day. When only mineral identifi cation and mineral concentrations and counts are required, the use of a Bulk Mineral Analysis routine reduces the analysis time from ~4 hours to ~30 minutes per sample.
DS201512-1939
2015
Simandl, G.J.Mao, M., Simandl, G.J., Spence, J., Marshall, D.Fluorite trace-element chemistry and its potential as an indicator mineral: evaluation of LA-ICP-MS method.Symposium on critical and strategic materials, British Columbia Geological Survey Paper 2015-3, held Nov. 13-14, pp. 251-264.TechnologyRare earths

Abstract: Fluorite (CaF2) belongs to the isometric system, with a cubic, face-centred lattice. Fluorite commonly forms cubes or octahedrons, less commonly dodecahedrons and, rarely, tetrahexahedrons, trapezohedrons, trisoctahedrons, hexoctahedrons, and botyroidal forms. Fluorite is transparent to translucent, and has vitreous luster. It occurs in a variety of colours including purple, green, blue, or yellow, however it can also be colourless, and can exhibit colour zoning, (Staebler et al., 2006). Fluorite from many localities is fl uorescent (Verbeek, 2006). Fluorite density varies from 3.0-3.6 g/cm3, depending to a large extent on inclusions and impurities in the crystal lattice (Staebler et al., 2006), and its hardness is 4 on Mohs scale (Berry et al., 1983). Many single fl uorite crystals display sector zoning, refl ecting preferential substitution and incorporation of trace elements along successive crystal surfaces (Bosce and Rakovan, 2001). The Ca2+ ion in the fl uorite crystal structure can be substituted by Li+, Na+, K+, Mg2+, Mn2+, Fe2+,3+, Zn2+, Sr2+, Y3+, Zr4+, Ba2+, lanthanides ions, Pb2+, Th4+, and U4+ ions (Bailey et al., 1974; Bill and Calas, 1978, Gagnon et al., 2003; Schwinn and Markl, 2005; Xu et al., 2012; Deng et al., 2014). Concentrations of these impurities do not exceed 1% (Deer, 1965) except in yttrofl uorite (Ca,Y)F2-2.33 and cerfl uorite (Ca,Ce)F2-2.33 (Sverdrup, 1968). Fluorite occurs in a variety of rocks, as an accessory and as a gangue mineral in many metalliferous deposits and, in exceptional cases, as the main ore constituent of economic deposits (Simandl, 2009). Good examples of fl uorite mines are Las Cuevas, Encantada-Buenavista (Mexico); St. Lawrence pluton-related veins and the Rock Candy Mine (Canada); El Hamman veins (Morocco) and LeBurc Montroc -Le Moulinal and Trebas deposits (France) as documented by Ruiz et al. (1980), Grogan and Montgomery (1975), González-Partida et al. (2003), Munoz et al. (2005), and Fulton III and Miller (2006). Fluorite also commonly occurs adjacent to or within carbonatites and alkaline complexes (Kogut et al., 1998; Hagni,1999; Alvin et al., 2004; Xu et al., 2004; Salvi and Williams-Jones, 2006); Mississippi Valley-type (MVT) Pb- Zn-F-Ba deposits; F-Ba-(Pb-Zn) veins (Grogan and Bradbury, 1967 and 1968; Baxter et al., 1973; Kesler et al., 1989; Cardellach et al., 2002; Levresse et al., 2006); hydrothermal Fe (±Au, ±Cu) and rare earth element (REE) deposits (Borrok et al., 1998; Andrade et al., 1999; Fourie, 2000); precious metal concentrations (Hill et al., 2000); fl uorite/metal-bearing skarns (Lu et al., 2003); Sn-polymetallic greissen-type deposits (Bettencourt et al., 2005); and zeolitic rocks and uranium deposits (Sheppard and Mumpton, 1984; Cunningham et al., 1998; Min et al., 2005). Ore deposit studies that document the trace element distribution in fl uorite are provided by Möller et al. (1976), Bau et al. (2003), Gagnon et al. (2003), Schwinn and Markl (2005), and Deng et al. (2014). The benchmark paper by Möller et al. (1976) identifi ed variations in the chemical composition of fl uorites according their origin (sedimentary, hydrothermal, or pegmatitic). Recently, Makin et al. (2014) compiled trace-element compositions of fl uorite from MVT, fl uorite-barite veins, peralkaline-related, and carbonatite-related deposits. They showed that fl uorite from MVT and carbonatite deposits can be distinguished through trace element concentrations, and that the REE concentration of fl uorite from veins is largely independent of the composition of the host rock. Based on the physical and chemical properties of fl uorite, its association with a variety of deposit types, and previous studies, it is possible that fl uorite can be used as a proximal indicator mineral to explore for a variety of deposit types. Unfortunately, the compilation by Makin et al. (2014) contained chemical analyses performed at different laboratories using different analytical techniques (including laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS), electron microprobe, neutron activation, and ICP-MS), and precision and accuracy varied accordingly. As an orientation survey, herein we present data from fi ve deposits, with two samples from the Rock Candy deposit (British Columbia), and one sample from each of Kootenay Florence (British Columbia), Eaglet (British Columbia), Eldor (Quebec), and Hastie quarry (Illinois) deposits (Table 1). The main objectives of this study are to: 1) assess variations in chemical composition of fl uorite in the samples and deposit types; 2) evaluate relations between analyses made using laser ablation-inductively coupled plasma mass spectrometry on individual grains [LA-ICP-MS(IG)], and those made using laser ablation-inductively coupled plasma mass spectrometry on fused beads [LA-ICP-MS(FB)] and X-ray fl uorescence (XRF); 3) test the use of stoichiometric Ca content as an internal fl uorite standard, such has been done by Gagnon et al. (2003) and Schwinn and Markl, (2005); 4) select the elements that are commonly present in concentrations above the lower limit of detection of LA-ICP-MS and available for constructing discrimination diagrams; 5) consider if our results agree with the preliminary discrimination diagrams of Makin et al. (2014).
DS201512-1969
2015
Simandl, G.J.Simandl, G.J.Carbonatites and related exploration targets.Symposium on critical and strategic materials, British Columbia Geological Survey Paper 2015-3, held Nov. 13-14, pp. 31-38.GlobalCarbonatite

Abstract: Mineralized carbonatite systems are multi-commodity, highly sought after, but poorly understood exploration targets (Mariano, 1989a, b; Pell, 1996; Birkett and Simandl, 1999). They are the main sources of niobium and rare earth elements (REE), which are considered critical metals for some key economic sectors (European Commission, 2014), and have become popular exploration targets for junior mining companies worldwide. Carbonatites also contribute to our understanding of the Earth’s mantle (e.g., Bell and Tilton, 2001, 2002). Herein, we discuss the defi nition and classifi cation of carbonatites; summarize information pertinent for carbonatite exploration such as tectonic setting, shape, geophysical signature, associated rocks, alteration, and temporal distribution; and highlight the multi-commodity aspect of carbonatiterelated exploration targets and mineral prospectivity. 2. Defi nition and classifi cation Carbonatites are defi ned by the International Union of Geological Sciences (IUGS) as igneous rocks containing more than 50% modal primary carbonates (Le Maitre, 2002). Depending on the predominant carbonate mineral, a carbonatite is referred to as a ‘calcite carbonatite’ (sövite), ‘dolomite carbonatite’ (beforsite) or ‘ankerite carbonatite’. If more than one carbonate mineral is present, the carbonates are named in order of increasing modal concentrations, for example a ‘calcite-dolomite carbonatite’ is composed predominately of dolomite. If non-essential minerals (e.g., biotite) are present, this can be refl ected in the name as ‘biotite-calcite carbonatite’. Where the modal classifi cation cannot be applied, the IUGS chemical classifi cation is used (Fig. 1). This classifi cation subdivides carbonatites into calciocarbonatites, magnesiocarbonatites, and ferrocarbonatites. For calciocarbonatites, the ratio of CaO/(CaO+MgO+FeO +Fe2O3+MnO) is greater than 0.8. The remaining carbonatites are subdivided (based on wt.% ratios) into magnesiocarbonatite [MgO > (FeO+Fe2O3+MnO)] and ferrocarbonatite [MgO < (FeO+Fe2O3+MnO)] (Woolley and Kempe, 1989; Le Maitre, 2002). If the SiO2 content of the rock exceeds 20%, the rock is referred to as silicocarbonatite. When the IUGS chemical classifi cation is used, care should be taken to ensure that magnetite and hematite-rich calciocarbonates or magnesiocarbonatites are not erroneously classifi ed as ferrocarbonatites (Gittins and Harmer, 1997). A refi nement to the IUGS chemical classifi cation based on molar proportions (Gittins and Harmer, 1997), introduced ‘ferrugineous’ carbonatites (Fig. 2). The boundary separating calciocarbonatites from magnesiocarbonatites and ‘ferrugineous’ carbonatites is set at 0.75, above which carbonatites contain more than 50% calcite on a molar basis. Although not universally accepted, Gittins and Harmer’s classifi cation is commonly used in studies of carbonatitehosted ore deposits. A mineralogical-genetic classifi cation of carbonatites was proposed by Mitchell (2005). His paper points to pitfalls of the IUGS classifi cation and subdivides carbonatites into ‘primary carbonatites’ and ‘carbothermal residua’. The introduction of the term ‘carbothermal residua’ is signifi cant as it alerts mantle specialists to fundamental processes involved in the formation of many carbonatite-related deposits, and reduces rifts between camps of ore deposit geologists, petrologists, and mantle specialists. From the exploration
DS201512-1970
2015
Simandl, G.J.Simandl, G.J., Akam, C., Paradis, S.Selected critical materials: uses, markets, and resources.Symposium on critical and strategic materials, British Columbia Geological Survey Paper 2015-3, held Nov 13-14 2015, pp. 1-4.GlobalStrategic materials
DS201602-0248
2016
Simandl, G.J.Trofanenko, J., Williams-Jones, A.E., Simandl, G.J., Migdisov, A.A.The nature and origin of the REE mineralization in the Wicheeda carbonatite, British Columbia, Canada.Economic Geology, Vol. 111, 1, pp. 199-223.Canada, British ColumbiaCarbonatite

Abstract: In response to rising demand of the rare earth elements (REE), recent exploration of the British Columbia alkaline province has identified the Wicheeda Carbonatite, which contains an estimated 11.3 million tons of light REE-enriched ore grading 1.95 wt.% TREO, to be the highest-grade prospect known in British Columbia. However, research of the deposit is restricted to one paper describing mineralization in carbonatite dikes adjacent to the main plug. This study describes the nature and origin of REEmineralization in the Wicheeda plug. The carbonatite was emplaced in metasedimentary limestone and argillaceous limestone belonging to the Kechika Group, which has been altered to potassic fenite immediately adjacent to the carbonatite and to sodic fenite at greater distances from it. The carbonatite comprises a ferroan dolomite core, which passes outwards gradationally into calcite carbonatite. Three texturally distinct varieties of dolomite have been recognized. Dolomite 1 constitutes most of the carbonatite; Dolomite 2 replaced Dolomite 1 near veins and vugs; Dolomite 3 occurs as a fracture and vug-lining phase with the REE mineralization. Stable carbon and oxygen isotopic ratios indicate that the calcite carbonatite is of mantle origin, that Dolomite 1 is of primary igneous origin, that Dolomite 2 is largely primary igneous with minor hydrothermal signature contamination, and that Dolomite 3 is of hydrothermal origin. Rare-metal mineralization in the deposit is, with the exception of pyrochlore, which occurs in the calcite carbonatite, restricted to veins and vugs in the dolomite carbonatite. There it occurs as hydrothermal veins and in vugs infilled by REE-fluorocarbonates, i.e., bastnäsite-(Ce), ancylite-(Ce), and monazite- (Ce) together with accessory pyrite, barite, molybdenite, and thorite. A model is proposed in which calcite carbonatite was the earliest magmatic phase to crystallize. The calcite carbonatite magma saturated with niobium relatively early, precipitating pyrochlore. The magma later evolved to a dolomite carbonatite composition which, upon cooling exsolved an aqueous carbonic fluid, which altered the Kechika metasediments to potassic fenite and mixed with formational waters further from the carbonatite to produce sodic fenite. This fluid mobilized the REE as chloride complexes into vugs and fractures in the dolomite carbonatite. Upon progressive fluid-rock interaction, the REE precipitated largely in response to cooling and pH. Hydrothermal concentration led to remarkable grade consistency, with virtually all of the dolomite carbonatite containing >1 wt.% TREO, making the Wicheeda Carbonatite a very attractive exploration target.
DS201605-0864
2016
Simandl, G.J.Mackay, D.A.R., Simandl, G.J., Ma, W., Redfearn, M., Gravel, J.Indicator mineral-based exploration for carbonatites and related specialty metal deposits - a QEMSCAN orientation survey, British Columbia. Aley, Lonnie, WicheedaJournal of Geochemical Exploration, Vol. 165, pp. 159-173.Canada, British ColumbiaGeochemistry - carbonatites

Abstract: This orientation survey indicates that Quantitative Evaluation of Materials by Scanning electron microscopy (QEMSCAN®) is a viable alternative to traditional indicator mineral exploration approaches which involve complex processing followed by visual indicator mineral hand-picking with a binocular microscope. Representative polished smear sections of the 125-250 µm fraction (dry sieved and otherwise unprocessed) and corresponding Mozley C800 table concentrates from the drainages of three carbonatites (Aley, Lonnie, and Wicheeda) in the British Columbia Alkaline Province of the Canadian Cordillera were studied. Polished smear sections (26 × 46 mm slide size) contained an average of 20,000 exposed particles. A single section can be analyzed in detail using the Particle Mineral Analysis routine in approximately 3.5-4.5 h. If only mineral identification and mineral concentrations are required, the Bulk Mineral Analysis routine reduces the analytical time to 30 min. The most useful carbonatite indicator minerals are niobates (pyrochlore and columbite), REE-fluorocarbonates, monazite, and apatite. Niobate minerals were identified in the 125-250 µm fraction of stream sediment samples more than 11 km downstream from the Aley carbonatite (their source) without the need for pre-concentration. With minimal processing by Mozley C800, carbonatite indicator minerals were detected downstream of the Lonnie and Wicheeda carbonatites. The main advantages of QEMSCAN® over the traditional indicator mineral exploration techniques are its ability to: 1) analyze very small minerals, 2) quickly determine quantitative sediment composition and mineralogy by both weight percent and mineral count, 3) establish mineral size distribution within the analyzed size fraction, and 4) determine the proportions of monomineralic (liberated) grains to compound grains and statistically assess mineral associations in compound grains. One of the key advantages is that this method permits the use of indicator minerals based on their chemical properties. This is impossible to accomplish using visual identification.
DS201801-0063
2017
Simandl, G.J.Simandl, G.J., Mackay, D.A.R., Ma, X., Luck, P., Gravel, J., Akam, C.The direct indicator mineral concept and QEMSCAN applied to exploration for carbonatite and carbonatite related ore deposits.in: Ferbey, T. Plouffe, A., Hickein, A.S. eds. Indicator minerals in tills and stream sediments of the Canadian Cordillera. Geological Association of Canada Special Paper,, Vol. 50, pp. 175-190.Canada, British Columbiacarbonatite - Aley, Lonnie, Wicheeda

Abstract: This volume consists of a series of papers of importance to indicator minerals in the Canadian Cordillera. Topics include the glacial history of the Cordilleran Ice Sheet, drift prospecting methods, the evolution of survey sampling strategies, new analytical methods, and recent advances in applying indicators minerals to mineral exploration. This volume fills a notable knowledge gap on the use of indicator minerals in the Canadian Cordillera. We hope that the volume serves as a user guide, encouraging the wider application of indicator minerals by the exploration community.
DS201811-2608
2018
Simandl, G.J.Simandl, G.J., Paradis, S.Carbonatites: related ore deposits, resources, footprint, and exploration methods.Applied Earth Science ( Trans. Inst. Min. Metall B), 31p. Doi.org/10.1080/25726388.2018.1516935 31p. Open accessGlobalcarbonatite - review

Abstract: Most carbonatites were emplaced in continental extensional settings and range in age from Archean to recent. They commonly coexist with alkaline silicate igneous rocks, forming alkaline-carbonatite complexes, but some occur as isolated pipes, sills, dikes, plugs, lava flows, and pyroclastic blankets. Incorporating cone sheets, ring dikes, radial dikes, and fenitisation-type halos into an exploration model and recognising associated alkaline silicate igneous rocks increases the footprint of the target. Undeformed complexes have circular, ring, or crescent-shaped aeromagnetic and radiometric signatures. Carbonatites can be effectively detected by soil, till, and stream-sediment geochemical surveys, as well as biogeochemical and indicator mineral surveys Carbonatites and alkaline-carbonatite complexes are the main sources of rare earth elements (REE) and Nb, and host significant deposits of apatite, vermiculite, Cu, Ti, fluorite, Th, U, natural zirconia, and Fe. Nine per cent of carbonatites and alkaline-carbonatite complexes contain active or historic mines, making them outstanding multi-commodity exploration targets.
DS201911-2507
2019
Simandl, G.J.Akam, C., Simandl, G.J., Lett, R., Paradis, S., Hoshino, M., Kon, Y., Araoka, D., Green, C., Kodama, S., Takagi, T., Chaudhry, M.Comparison of methods for the geochemical determination of rare earth elements: Rock Canyon Creek REE-F-Ba deposit case study, SE British Columbia, Canada.Geochemistry: Exploration, Environment, Analysis, Vol. 19, pp. 414-430.Canada, British Columbiageochemistry

Abstract: Using Rock Canyon Creek REE-F-Ba deposit as an example, we demonstrate the need for verifying inherited geochemical data. Inherited La, Ce, Nd, and Sm data obtained by pressed pellet XRF, and La and Y data obtained by aqua regia digestion ICP-AES for 300 drill-core samples analysed in 2009 were compared to sample subsets reanalysed using lithium metaborate-tetraborate (LMB) fusion ICP-MS, Na2O2 fusion ICP-MS, and LMB fusion-XRF. We determine that LMB ICP-MS and Na2O2 ICP-MS accurately determined REE concentrations in SY-2 and SY-4, and provided precision within 10%. Fusion-XRF was precise for La and Nd at concentrations exceeding ten times the lower detection limit; however, accuracy was not established because REE concentrations in SY-4 were below the lower detection limit. Analysis of the sample subset revealed substantial discrepancies for Ce concentrations determined by pressed pellet XRF in comparison to other methods due to Ba interference. Samarium, present in lower concentrations than other REE compared, was underestimated by XRF methods relative to ICP-MS methods. This may be due to Sm concentrations approaching the lower detection limits of XRF methods, elemental interference, or inadequate background corrections. Aqua regia dissolution ICP-AES results, reporting for La and Y, are underestimated relative to other methods.
DS202010-1877
2018
Simandl, G.J.Simandl, G.J., Paradis, S.Carbonatites: related ore deposits, resources, footprint, and exploration methods.Applied Earth Science Transactions of the Institute of Mining and Metallurgy, doi.org/10.1080/ 25726838.2018.1516935 32p. Pdf Globalcarbonatite

Abstract: Most carbonatites were emplaced in continental extensional settings and range in age from Archean to recent. They commonly coexist with alkaline silicate igneous rocks, forming alkaline-carbonatite complexes, but some occur as isolated pipes, sills, dikes, plugs, lava flows, and pyroclastic blankets. Incorporating cone sheets, ring dikes, radial dikes, and fenitisation-type halos into an exploration model and recognising associated alkaline silicate igneous rocks increases the footprint of the target. Undeformed complexes have circular, ring, or crescent-shaped aeromagnetic and radiometric signatures. Carbonatites can be effectively detected by soil, till, and stream-sediment geochemical surveys, as well as biogeochemical and indicator mineral surveys Carbonatites and alkaline-carbonatite complexes are the main sources of rare earth elements (REE) and Nb, and host significant deposits of apatite, vermiculite, Cu, Ti, fluorite, Th, U, natural zirconia, and Fe. Nine per cent of carbonatites and alkaline-carbonatite complexes contain active or historic mines, making them outstanding multi-commodity exploration targets.
DS201412-0832
2014
Simandl, L.J.Simandl, G.J., Paradis, S., Stone, R.S., Fajber, R., Kressall, R.D., Grattan, K., Crozier, J., Simandl, L.J.Applicablity of handheld X-ray fluroescence spectrometry in the exploration and development of carbonatite related niobium deposits: a case study of the Aley carbonatite, British Columbia, Canada.Geochemistry: Exploration, Environment, Analysis, Vol. 14, 3, pp. 211-221.Canada, British ColumbiaCarbonatite
DS1997-0173
1997
Simard, A.Caty, J.L., Simard, A., Leclair, A.Le nouveau programme du Grand Nord - un regard vers l'avenirQuebec Department of Mines, DV 97-03, p. 9.QuebecExploration - assessment
DS1985-0090
1985
Simard, R.Broome, J., Simard, R., Teskey, D.Presentation of magnetic anomaly map dat a by stereo projection at magneticshadowgrams.Canadian Journal of Earth Sciences, Vol. 22, pp. 311-14.Northwest TerritoriesLockhart River, Thelon River, Geophysics - Magnetics
DS201912-2832
2019
Sime, N.van Keken, P.E., Wada, I., Sime, N., Abers, G.A.Thermal structure of the forearc in subduction zones: a comparison of methodologies.Geochemistry, Geophysics, Geosystems, Vol. 20, pp. 3268-3288.Mantlesubduction

Abstract: Molnar and England (1990, https://doi.org/10.1029/JB095iB04p04833) introduced equations using a semianalytical approach that approximate the thermal structure of the forearc regions in subduction zones. A detailed new comparison with high-resolution finite element models shows that the original equations provide robust predictions and can be improved by a few modifications that follow from the theoretical derivation. The updated approximate equations are shown to be quite accurate for a straight-dipping slab that is warmed by heat flowing from its base and by shear heating at its top. The approximation of radiogenic heating in the crust of the overriding plate is less accurate but the overall effect of this heating mode is small. It is shown that the previous and updated approximate equations become increasingly inaccurate with decreasing thermal parameter and increasing variability of slab dip. It is also shown that the approximate equations cannot be extrapolated accurately past the brittle-ductile transition. Conclusions in a recent paper (Kohn et al., 2018, https://doi.org/10.1073/pnas.1809962115) that modest amount of shear heating can explain the thermal conditions of past subduction from the exhumed metamorphic rock record are invalid due to a number of compounding errors in the application of the Molnar and England (1990, https://doi.org/10.1029/JB095iB04p04833) equations past the brittle-ductile transition. The use of the improved approximate equations is highly recommended provided their limitations are taken into account. For subduction zones with variable dip and/or low thermal parameter finite element modeling is recommended.
DS202004-0514
2020
Sime, N.Gebralle, Z.M., Sime, N., Badro, J., van Kekn, P.E.Thermal conductivity near the bottom of the Earth's lower mantle: mesurements of pyrolite up to 120 GPa and 2500 K. Earth and Planetary Science Letters, Vol. 536, 116161 7p. PdfMantlegeothermometry

Abstract: Knowledge of thermal conductivity of mantle minerals is crucial for understanding heat transport from the Earth's core to mantle. At the pressure-temperature conditions of the Earth's core-mantle boundary, calculations of lattice thermal conductivity based on atomistic models have determined values ranging from 1 to 14 W/m/K for bridgmanite and bridgmanite-rich mineral assemblages. Previous studies have been performed at room temperature up to the pressures of the core-mantle boundary, but correcting these to geotherm temperatures may introduce large errors. Here we present the first measurements of lattice thermal conductivity of mantle minerals up to pressures and temperatures near the base of the mantle, 120 GPa and 2500 K. We use a combination of continuous and pulsed laser heating in a diamond anvil cell to measure the lattice thermal conductivity of pyrolite, the assemblage of minerals expected to make up the lower mantle. We find a value of W/m/K at 80 GPa and 2000 to 2500 K and 5.9 W/m/K at 124 GPa and 2000 to 3000 K. These values rule out the highest calculations of thermal conductivity of the Earth's mid-lower mantle (i.e. W/m/K at 80 GPa), and are consistent with both the high and low calculations of thermal conductivity near the base of the lower mantle.
DS202005-0733
2020
Sime, N.Geballe, Z.M., Sime, N., Badro, J., van Keken, P.E., Goncharov, A.F.Thermal conductivity near the bottom of the Earth's lower mantle: measurements of pyrolite up to 120 Gpa and 2500 K.Earth and Planetary Science Letters, Vol. 536, 116161, 11p. PdfMantlegeothermometry

Abstract: Knowledge of thermal conductivity of mantle minerals is crucial for understanding heat transport from the Earth's core to mantle. At the pressure-temperature conditions of the Earth's core-mantle boundary, calculations of lattice thermal conductivity based on atomistic models have determined values ranging from 1 to 14 W/m/K for bridgmanite and bridgmanite-rich mineral assemblages. Previous studies have been performed at room temperature up to the pressures of the core-mantle boundary, but correcting these to geotherm temperatures may introduce large errors. Here we present the first measurements of lattice thermal conductivity of mantle minerals up to pressures and temperatures near the base of the mantle, 120 GPa and 2500 K. We use a combination of continuous and pulsed laser heating in a diamond anvil cell to measure the lattice thermal conductivity of pyrolite, the assemblage of minerals expected to make up the lower mantle. We find a value of W/m/K at 80 GPa and 2000 to 2500 K and 5.9 W/m/K at 124 GPa and 2000 to 3000 K. These values rule out the highest calculations of thermal conductivity of the Earth's mid-lower mantle (i.e. W/m/K at 80 GPa), and are consistent with both the high and low calculations of thermal conductivity near the base of the lower mantle.
DS200512-0388
2005
Simic, D.Hainschwang, T., Simic, D., Fritsch, E., Deljanin, B., Woodring, S., DelRe, N.A gemological study of a collection of Chameleon diamonds.Gems & Gemology, Vol. 41, 1, Spring pp. 20-34.Diamond morphology - Chamelon - colour change
DS200712-0233
2006
Simic, D.Deljanin, B., Simic, D.Cross referencing identification system (CIS): database and tool for diamond research.Gems & Gemology, 4th International Symposium abstracts, Fall 2006, p.163-64. abstract onlyTechnologyCIS
DS200712-0234
2006
Simic, D.Deljanin, B., Simic, D., Epeloym, M., Zaitsev, A.M.Study of fancy color and near colorless HPHT grown synthetic diamonds from advanced optical technology Co. Canada.Gems & Gemology, 4th International Symposium abstracts, Fall 2006, p.154-5. abstract onlyTechnologySynthetic diamonds
DS200812-0279
2008
Simic, D.Deijanin, B., Simic, D., Zaitsev, A., Chapman, J., Dobrinets, I., Widemann, A., Del Re, N., Middleton, T., Dijanin, E., Se Stefano, A.Characterization of pink diamonds of different origin: natural ( Argyle, non-Argyle), irradiated and annealed, treated with multi-process, coated and synthetic.Diamond and Related Materials, Vol. 17, 7-10, pp. 1169-1178.AustraliaPink diamonds
DS200412-0515
2003
Simionovici, A.S.El Goresy, A., Dubrovinsky, L.S., Gillet, P., Mostefaoul, S., Graup, G., Drakopoulos, M., Simionovici, A.S.A new natural super hard transparent polymorph of carbon from the Popigai impact crater, Russia.Comptes Rendus Geoscience, Vol. 335, 12, Oct. pp. 889-898.RussiaLonsdaleite, graphite, mineralogy
DS201412-0222
2003
Simionovici, A.S.El Goresy, A., Dubrovinsky, L.S., Gillet, P., Mostefaoui, S., Graup, G., Drakopoulos, M., Simionovici, A.S., Swamy, V., Masaitis, V.L.A new natural, super-hard, transparent polymorph of carbon from the Popigai impact crater, Russia.Comptes Rendus Geoscience, Vol. 335, pp. 889-898.Russia, YakutiaMeteorite
DS201812-2820
2018
Simister, R.L.Iulianella Phillips, B.P., Simister, R.L., Cayer, E.M., Winterburn, P.A., Crowe, S.A.Direct discovery of concealed kimberlites with microbial community fingerprinting. 2018 Yellowknife Geoscience Forum , p. 36. abstractCanada, Northwest Territoriesmineral chemistry

Abstract: Mineral exploration in Canada is becoming increasingly complex as the majority of undiscovered commodities are likely deeply buried beneath significant glacial overburden and bedrock, reducing the effectiveness of many existing tools. The development of innovative exploration protocols and techniques is imperative to the continuation of discovery success. Preliminary experimentation has demonstrated the potential viability of microbial fingerprinting through genetic sequencing to directly identify the projected subcrop of mineralization in addition to the more distal entrained geochemical signatures in till. With the advent of inexpensive modern sequencing technology and big-data techniques, microbiological approaches to exploration are becoming more quantitative, cost effective, and efficient. The integration of microbial community information with soil chemistry, mineralogy and landscape development coupled with geology and geophysics propagates the development of an improved decision process in mineral exploration. Soils over porphyry, kimberlite, and VMS deposits have undergone microbial community profiling. These community-genome derived datasets have been integrated with trace metal chemistry, mineralogy, surface geology and other environmental variables including Eh and pH. Analyses of two kimberlites in the Northwest Territories show significant microbial community shifts that are correlated with subsurface mineralization, with distinctive microbial community profiles present directly above the kimberlite. The relationship between microbial profiles and mineralization leads to the use of microbial fingerprinting as a method for more accurately delineating ore deposits in glacially covered terrain. As databases are developed, there is potential for application as a field based technique, as sequencing technology is progressively developed into portable platforms.
DS201912-2814
2019
Simister, R.L.Phillips, I., Simister, R.L., Winterburn, P.A., Crowe, S.A.Microbial community fingerprinting as a tool for direct detection of buried kimberlites.Yellowknife Forum NWTgeoscience.ca, abstract volume p. 42-43.Canada, Northwest Territorieskimberlite

Abstract: Mineral exploration in northern latitudes is challenging in that undiscovered deposits are likely buried beneath significant glacial overburden. The development of innovative exploration strategies and robust techniques to see through cover is imperative to future discovery success. Microbial communities are sensitive to subtle environmental fluctuations, reflecting these changes on very short timescales. Shifts in microbial community profiles, induced by chemical differences related to geology, are detectable in the surficial environment, and can be used to vector toward discrete geological features. The modernization of genetic sequencing and big-data evaluation allows for efficient and cost-effective microbial characterization of soil profiles, with the potential to see through glacial cover. Results to date have demonstrated the viability of microbial fingerprinting to directly identify the surface projection of kimberlites in addition to entrained geochemical signatures in till. Soils above two kimberlites in the Northwest Territories, have undergone microbial community profiling. These community-genome derived datasets have been integrated with chemistry, mineralogy, surface geology, vegetation type and other environmental variables including Eh and pH. Analyses show significant microbial community shifts, correlated with the presence of kimberlites, with a distinct community response at the species level directly over known deposits. Diversity of soil bacteria is also depressed in the same regions of the microbial community response. The relationship between microbial profiles and buried kimberlites has led to the application of microbial fingerprinting as a method to accurately delineate potential ore deposits in covered terrain. The integration of microbial community information with soil chemistry and landscape development coupled with geology and geophysics significantly improves the drill / no-drill decision process and has proven to be far more accurate than traditional surficial exploration methods. There is high potential for application as a field-based technique as microbial databases for kimberlites in northern regions are refined, and as sequencing technology is progressively developed into portable platforms.
DS1986-0739
1986
Simitsyn, A.V.Simitsyn, A.V., et al.The mesozoic tectonic and magmatic activation in the northern part of the Russian plate.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 287, No. 6, pp. 1458-1461RussiaTectonics
DS1997-1044
1997
Simiyu, S.M.Simiyu, S.M., Keller, G.R.An integrated analysis of lithospheric structure across the East African plateau based on gravity anomalies.Tectonophysics, Vol. 278, No. 1-4, Sept. 15, pp. 291-314.Africa, east Africa, Tanzania, KenyaTectonics, Geophysics - gravity
DS2000-0409
2000
Simiyu, S.M.Hicks, N.O., Keller, G.R., Simiyu, S.M.An integrated interpretation of structure of the upper crust of the Kenya Rift from remote sensing, gravity14th. International Conference Applied Remote Sensing, Nov. 1p. abstractKenyaRemote sensing, Tectonics
DS1993-1467
1993
Simkin, T.Simkin, T.Terrestrial volcanism in space and timeAnnual Review of Earth Planetary Science, Vol. 21, pp. 427-452Globalvolcanism., Tectonics -setting
DS1995-1757
1995
Simkin, T.Simkin, T., et al.The dynamic planet: world map of volcanoes, earthquakes, impact craters and plate tectonicsUnited States Geological Survey (USGS) Map, !: 30, 000, 000 $ 4.25GlobalMap, Volcanoes, craters, plate tectonics
DS1989-1393
1989
Simkiss, K.Simkiss, K.Biomineralization in the context of geological timeTransactions Royal Society of Edibnburgh Earth Sciences, Vol. 80, pp. 193-199GlobalBiomineralization -review, Precambrian-Cambrian boundary
DS1982-0504
1982
Simkiv, ZH. A.Popivnyak, I.V., Simkiv, ZH. A.Soluable Components of Mantle Derived Mineral Forming MediaDoklady Academy of Science USSR, Earth Science Section., Vol. 256, No. 4, PP. 181-184.RussiaSytykan, Pyrope, Garnet, Kimberlite, Analyses, Fluid Inclusions
DS200512-1193
2005
Simmat, C.M.Wolmarans, A., Cloete, J.H., Ekkerd, J., Mason, I.M., Simmat, C.M.Borehole radar application to kimberlite delineation at Finsch diamond mine.Exploration Geophysics, Vol. 36, 3, pp. 310-317.Africa, South AfricaFinsch mine
DS200812-0770
2008
SimmonsMoucha, R., Forte, A.M., Mitrovica, J.X., Rowley, D.B., Quere, S., Simmons, Grand, S.P.Dynamic topography and long term sea level variations: there is no such thing as a stable continental platform.Earth and Planetary Science Letters, Vol. 271, 1-4, pp. 101-108.MantleGeomorphology
DS2002-1488
2002
Simmons, A.Simmons, A., Helmstaedt, H.Petrography and geochemistry of the Nicholas Bay kimberlite, Lac de Gras kimberlite project, NWT.30th. Yellowknife Geoscience Forum, Abstracts Of Talks And Posters, Nov. 20-22, p. 61. abstractNorthwest TerritoriesGeochemistry
DS1981-0378
1981
Simmons, B.Simmons, B.State Gets Bid to Allow Diamond Mine in ParkArkansaw DEMOCRAT., APRIL 3RD. 2P.United States, Gulf Coast, Arkansas, PennsylvaniaProspecting News Item
DS1992-1406
1992
Simmons, B.D.Simmons, B.D.Teck's exploration approach in eastern CanadaThe Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Exploration and Mining Geology, Vol. 1, No. 3, July pp. 209-212Ontario, QuebecExploration, economics, Philosophy -Teck Corp
DS1994-1604
1994
Simmons, B.D.Simmons, B.D.Developing an international mineral exploration programmeCanadian Institute 1994 Canadian Mining Symposium, Preprint, 17pGlobalEconomics, Mining industry -exploration
DS1989-0453
1989
Simmons, C.Frost, B.R., Lindsley, D.H., Simmons, C.Origin and evolution of anorthosites and related rocks. Report PenroseConferenceGeology, Vol. 17, No. 5, May pp. 474-475GlobalAnorthosites, Penrose Conference Rept
DS1980-0268
1980
Simmons, G.Padovani, E., Simmons, G.Constraints on Crustal Hydration Beneath the Colorado Plateau from Major Element Chemistry and Physical Properties of Crustal Xenoliths.Eos, Vol. 61, No. 17, P. 388, (abstract.).Colorado PlateauKimberlite, Rocky Mountains
DS1960-1026
1968
Simmons, G.C.Simmons, G.C.Geology and Mineral Resources of the Barao de Cocais Area, Minas Gerais, Brasil.United States Geological Survey (USGS) PROF. PAPER., No. 341-H, H46P.BrazilBlank
DS2000-0898
2000
Simmons, N.A.Simmons, N.A., Giroola, H.Multiple seismic discontinuities near the base of the transition zone in the Earth's mantle.Nature, Vol. 405, No. 6786, June 1, pp. 559-61.MantleGeophysics - seismics, Discontinuity
DS2002-1489
2002
Simmons, N.A.Simmons, N.A., Grand, S.P.Partial melting in the deepest mantleGeophysical Research Letters, Vol. 29, 10, DOI 10.1029/2001GL013716MantleMelting
DS200612-1307
2006
Simmons, N.A.Simmons, N.A., Forte, A.M., Grand, S.P.Constraining mantle flow with seismic and geodynamic data: a joint approach.Earth and Planetary Science Letters, Vol. 246, 1-2, June 15, pp. 109-124.MantleGeophysics - seismics
DS200812-0771
2008
Simmons, N.A.Moucha, R., Forte, A.M., Mitrovica, J.X., Rowley, D.B., Quere, S., Simmons, N.A., Grand, S.P.Dynamic topography and long term sea level variations: there is no such thing as a stable continental platform.Earth and Planetary Science Letters, Vol. 271, 1-4, pp. 101-108.MantleCraton
DS200812-0772
2008
Simmons, N.A.Moucha, R., Forte, A.M., Rowley, D.B., Mitrovica, J.X., Simmons, N.A., Grand, S.P.Mantle convection and the recent evolution of the Colorado Plateau and the Rio Grande Rift valley.Geology, Vol. 36, 6, pp. 439-442.United States, Colorado PlateauConvection
DS201012-0206
2010
Simmons, N.A.Forte, A.M., Moucha, R., Simmons, N.A., Grand, S.P., Mitrovica, J.X.Deep mantle contributions to the surface dynamics of the North American continent.Tectonophysics, Vol.481, 1-4, pp. 3-15.Canada, United StatesTectonics
DS201012-0207
2010
Simmons, N.A.Forte, A.M., Quere, S., Moucha, R., Simmons, N.A., Grand, S.P., Mitrovica, J.X., Rowley, D.B.Joint seismic geodynamic mineral physical modeling of African geodynamics: a reconciliation of deep mantle convection with surface geophysical constraints.Earth and Planetary Science Letters, Vol. 295, 3-4, pp. 329-341.AfricaGeophysics - seismics
DS1989-1014
1989
Simmons, W.B.Meurer, W.P., Falster, A.U., Simmons, W.B., Hanson, S.L., Rog, A.M.Trace mineralogy of the Magnet Cove carbonatite, ArkansawSixteenth Rochester Mineralogical Symposium, Rocks and Minerals, held April, Vol. 64, No. 6, December p. 473. Summary onlyArkansasCarbonatite, Magnet Cove
DS201212-0658
2012
Simmons, W.B.Simmons, W.B., Pezzotta, F., Shigley, J.E., Beurlen, H.Granitic pegmatites as sources of colored gemstones.Episodes, Vol. 8, pp. 281-287.GlobalGemstones
DS201910-2300
2019
Simms, M.J.Simms, M.J., Emston, K.A reassessment of the proposed "Lairg impact structure" and its potential implications for the deep structure of northern Scotland.Journal of the Geological Society, Vol. 76, pp. 817-829.Europe, Scotlandimpact crater

Abstract: The Lairg Gravity Low may represent a buried impact crater c. 40 km across that was the source of the 1.2 Ga Stac Fada Member ejecta deposit but the gravity anomaly is too large to represent a simple crater and there is no evidence of a central peak. Reanalysis of the point Bouguer gravity data reveals a ring of positive anomalies around the central low, suggesting that it might represent the eroded central part of a larger complex crater. The inner or peak rings of complex craters show a broadly consistent 2:1 relationship between ring diameter and total crater diameter, implying that the putative Lairg crater may be as much as 100 km across. This would place the crater rim within a few kilometres of the Stac Fada Member outcrop, a location inconsistent with the thickness and clast size of the ejecta deposit. We propose that the putative impact crater originally lay further east, substantially further from the Stac Fada Member than today, and was translocated westwards to its present location beneath Lairg during the Caledonian Orogeny. This model requires that a deep-seated thrust fault, analogous to the Flannan and Outer Isles thrusts, exists beneath the Moine Thrust in north-central Scotland.
DS201212-0150
2012
Simneti, A.De Bruin, D., Barton, E., Simneti, A.The Sr isotope compositions of clinopyroxene megacrysts determined by ICP-MS-LA from localities across the Kaapvaal Craton through the ages.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractAfrica, South AfricaGeochemistry
DS1989-0885
1989
SimoesLima da Costa, M., Simoes, Angelica, R., Lima Lemos, R.Geochemical exploration on the Maicuru alkaline-ultramafic carbonatiticcomplexXiii International Geochemical Exploration Symposium, Rio 89 Brazilian Geochemical, pp. 62-64. AbstractBrazilCarbonatite, Maicuru
DS2001-0594
2001
SimonKgaswane, E.M., Wright, Simon, KwadibaThe characterization of southern African seismicity April 1997-1999. Implications for refining models ..Slave-Kaapvaal Workshop, Sept. Ottawa, 6p. abstractMantleGeophysics - seismics, Sub-cratonic lithosphere
DS2001-0644
2001
SimonKwadiba, M., Wright, James, Kgaswane, Simon, Niu, SchuttCrustal phases and the structure of the crust beneath the Kaapvaal CratonSlave-Kaapvaal Workshop, Sept. Ottawa, 2p. abstractSouth AfricaTectonics, Geophysics - teleseismic
DS2001-1259
2001
SimonWright, C., Kwadiba, Kgaswane, SimonP and S wavespeeds in the crust and upper mantle below the Kaapvaal Cratonin depths of 320 KM from earthquakeSlave-Kaapvaal Workshop, Sept. Ottawa, 5p. abstractSouth AfricaGeophysics - local and mining earthquakes
DS201312-0414
2013
Simon, A.C.Hudgins, T.R., Mukasa, S.B., Simon, A.C.Melt inclusion evidence for a CO2 rich mantle beneath the western branch of the East African Rift.Goldschmidt 2013, 1p. abstractMantleSubduction
DS201506-0274
2015
Simon, A.C.Hudgins, T.R., Mukasa, S.B., Simon, A.C., Moore, G., Barifaijo, E.Melt inclusion evidence for CO2 rich melts beneath the western branch of the East African Rift: implications for long term storage of volatiles in the deep lithospheric mantle.Contributions to Mineralogy and Petrology, Vol. 169, 5p.Africa, East AfricaBasanites, Foidites
DS201801-0020
2018
Simon, B.Guillocheau, F., Simon, B., Baby, G., Bessin, P., Robin, C., Dauteuil, O.Planation surfaces as a record of mantle dynamics: the case of Africa.Gondwana Research, Vol. 53, 1, pp. 82-98.Africageodynamics

Abstract: There are two types of emerged relief on the Earth: high elevation areas (mountain belts and rift shoulders) in active tectonic settings and low elevation domains (anorogenic plateaus and plains) characteristic of the interior of the continents i.e. 70% of the Earth emerged relief. Both plateaus and plains are characterized by large erosional surfaces, called planation surfaces that display undulations with middle (several tens of kilometres) to very long (several thousands of kilometres) wavelengths, i.e. characteristic of lithospheric and mantle deformations respectively. Our objective is here (1) to present a new method of characterization of the very long and long wavelength deformations using planation surfaces with an application to Central Africa and (2) to reconstruct the growth of the very long wavelength relief since 40 Ma, as a record of past mantle dynamics below Central Africa. (i) The African relief results from two major types of planation surfaces, etchplains (weathering surfaces by laterites) and pediplains/pediments. These planation surfaces are stepped along plateaus with different elevations. This stepping of landforms records a local base level fall due to a local tectonic uplift. (ii) Central Africa is an extensive etchplain-type weathering surface - called the African Surface - from the uppermost Cretaceous (70 Ma) to the Middle Eocene (45 Ma) with a paroxysm around the Early Eocene Climatic Optimum. Restoration of this surface in Central Africa suggests very low-elevation planation surfaces adjusted to the Atlantic Ocean and Indian Ocean with a divide located around the present-day eastern branch of the East African Rift. (iii) The present-day topography of Central Africa is younger than 40 -30 Ma and records very long wavelength deformations (1000 -2000 km) with (1) the growth of the Cameroon Dome and East African Dome since 34 Ma, (2) the Angola Mountains since 15 -12 Ma increasing up to Pleistocene times and (3) the uplift of the low-elevation (300 m) Congo Basin since 10 -3 Ma. Some long wavelength deformations (several 100 km) also occurred with (1) the low-elevation Central African Rise since 34 Ma and (2) the Atlantic Bulge since 20 -16 Ma. These very long wavelength deformations record mantle dynamics, with a sharp increase of mantle upwelling around 34 Ma and an increase of the wavelength of the deformation and then of mantle convection around 10 -3 Ma.
DS1994-1605
1994
Simon, J.L.Simon, J.L., Weinrauch, G., Moore, S.The reserves of extracted resources: historical dataNonrenewable Resources, Vol. 3, No. 4, Winter pp. 325-340GlobalEconomics, Forecasting, metal prices, resource scarcity
DS2002-1746
2002
Simon, K.Xiao, Y., Hoefs, J., Van den Kerkof, A.M., Simon, K., Fiebig, J., Zheng, Y.F.Fluid evolution in the Baia Mare epithermal gold/polymetallic district, Inner Carpathians, RomaniaJournal of Petrology, Vol. 43, No. 8, pp. 1505-28.ChinaGeochemistry, UHP
DS200612-1554
2006
Simon, K.Xiao, Y., Sun, W., Hoefs, J., Simon, K., Zhang, Z., Li, S., Hofmann, A.W.Making continental crust through slab melting: constraints from niobium tantalum fractionation in UHP metamorphic rutile.Geochimica et Cosmochimica Acta, Vol. 70, 18, Sept. 15, pp. 4770-47082.ChinaDabie Sulu - eclogites - UHP
DS200412-0347
2004
Simon, L.Coltice, N., Simon, L., Lecuyer, C.Carbon isotope cycle and mantle structure.Geophysical Research Letters, Vol. 31, 5, March 16, DOI 10.1029/2003 GLO18873MantleTectonics
DS200512-0991
2005
Simon, L.Simon, L., Lecuyer, C.Continental recycling: the oxygen isotope point of view.Geochemistry, Geophysics, Geosystems: G3, Vol. 6, doi. 10.1029/2005 GC000958MantleGeochronology, low temperature alteration
DS201808-1789
2018
Simon, M.Simon, M., Bongiolo, E.M., Avila, C.A., Oliveira, E.P., Texeira, W., Stohler, R.C., Soares de Oliveira, F.V.Neoarchean reworking of TTG like crust in the southern most portion of the Sao Francisco craton: U-Pb zircon dating and geochemical evidence from the Sao Tiago batholith.Precambrian Research, Vol. 314, pp. 353-376.South America, Brazilcraton

Abstract: Field, petrographic and geochemical data combined with in situ zircon U-Pb LA-ICP-MS ages are documented for the São Tiago Batholith (southernmost portion of the São Francisco Craton) to understand its origin and magmatic evolution. The geologic relations indicate that the batholith is composed of granitic to granodioritic orthogneisses (L2) with tonalitic xenoliths (L1) intruded by pegmatite (L3) and metagranite (L4). L1 consists of two facies of tonalitic orthogneiss, one biotite-rich, and the other biotite-poor. The geochemical evidence, including high K2O with mantle-like chemical signature, suggests that the Bt-rich tonalitic gneiss (2816?±?30?Ma) was derived from contamination of mafic magmas by crustal-derived components. The Bt-poor tonalitic gneiss, of TTG affinity, was generated by partial melting of LILE-enriched mafic rocks, possibly from oceanic plateus in a subduction environment. L2 includes two distinct types of rocks: (i) granodioritic orthogneiss, chemically ranging from medium-pressure TTGs to potassic granitoids originated via partial melting of previous TTG crust, including L1 Bt-poor; and (ii) granitic gneiss (2664?±?4?Ma), geochemically similar to crustal-derived granites, produced by melting of the L1 Bt-rich tonalitic gneiss or mixed TTG/metasedimentary sources. L3 pegmatite (2657?±?23?Ma) results from melting of L2, whereas L4 metagranite (dikes and stocks) shows petrogenesis similar to that of the L2 granitic gneiss. Related orthogneisses occur near the São Tiago Batholith: (i) a hornblende-bearing tonalitic gneiss, and (ii) a hybrid hornblende-bearing granitic gneiss (2614?±?13?Ma), whose genesis is linked with interaction of sanukitoid and felsic potassic melts, representing the last Archean magmatic pulse of the region. The Minas strata along the Jeceaba-Bom Sucesso lineament near our study region encircle the São Tiago Archean crust, representing an irregular paleo-coastline or a micro-terrane amalgamation with the São Francisco Proto-craton, with possible subsequent dome-and-keel deformational processes. Our petrological and geochronological data reevaluate nebulous concepts in the literature about the SFC, revealing (i) a chemically and compositionally diverse crustal segment generated at the Late Archean in diverse geodynamic scenarios, and (ii) a more complex lineament than previously thought in terms of the paleogeography of the southern São Francisco Craton.
DS2001-1079
2001
Simon, N.Simon, N.Origin of garnet and clinopyroxene in Kaapvaal low T peridotite xenoliths:implications from secondary ion..Slave-Kaapvaal Workshop, Sept. Ottawa, 5p. abstractSouth Africa, LesothoSIMS data, Geochemistry - major and trace elements
DS2003-1278
2003
Simon, N.S.Simon, N.S., Irvine, G.J., Davies, G.R., Pearson, D.G., Carlson, R.W.The origin of garnet and clinopyroxene in 'depleted' Kaapvaal peridotitesLithos, Vol. 71, 2-4, pp. 289-322.South AfricaMineral chemistry
DS200412-1831
2003
Simon, N.S.Simon, N.S., Irvine, G.J., Davies, G.R., Pearson, D.G., Carlson, R.W.The origin of garnet and clinopyroxene in 'depleted' Kaapvaal peridotites.Lithos, Vol. 71, 2-4, pp. 289-322.Africa, South AfricaMineral chemistry
DS2001-0896
2001
Simon, N.S.C.Pearson, D.G., Biyd, F.R., Simon, N.S.C.Modal mineralogy and geochemistry of Kaapvaal peridotites: the origin of garnet diopside - stabilitySlave-Kaapvaal Workshop, Sept. Ottawa, 7p. abstractSouth AfricaCraton - stability
DS2003-1279
2003
Simon, N.S.C.Simon, N.S.C., Carlosn, R.W., Davies, D.R., Nowell, G.M., Pearson, D.G.OS SR ND HF isotope evidence for the ancient depletion and subsequent multi stage8ikc, Www.venuewest.com/8ikc/program.htm, Session 4, POSTER abstractSouth AfricaMantle geochemistry, Geochronology
DS200612-0945
2006
Simon, N.S.C.Morel, M.L.A., Simon, N.S.C., Davies, G.F., Pearson, G.D.Modification of cratonic lithosphere: influence of tectono magmatic events on Kaapvaal craton ( South Africa).Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 428. abstract only.Africa, South AfricaMagmatism, tectonics
DS200712-0779
2007
Simon, N.S.C.Neumann, E.R., Simon, N.S.C., Bonadiman, C., Coltorti, Delpech, GregorieExtremely refractory oceanic lithospheric mantle and its implications for geochemical mass balance.Plates, Plumes, and Paradigms, 1p. abstract p. A712.MantleHarzburgite
DS200712-0990
2007
Simon, N.S.C.Simon, N.S.C., Carlson, R.W., Pearson, D.G., Davies, G.R.The origin and evolution of the Kaapvaal Cratonic lithospheric mantle.Journal of Petrology, Vol. 48, 3, pp. 589-625.Africa, South AfricaTectonics
DS200812-0484
2008
Simon, N.S.C.Hopp, J., Trieloff, M., Brey, G.P., Woodland, A.B., Simon, N.S.C., Wijbrans, J.R., Siebel, W., Reitter, E.40 Ar 39 Ar ages of phlogopite in mantle xenoliths from South African kimberlites: evidence for metasomatic mantle impregnation during Kilbaran orogenic cycle.Lithos, Vol. 106, no. 3-4, pp. 351-364.Africa, South Africa, LesothoDeposit - Bultfontein, Letseng, Liqhobong
DS200812-1070
2008
Simon, N.S.C.Simon, N.S.C., Podladchikov, Y.Y.The effect of mantle composition on density in the extending lithosphere.Earth and Planetary Science Letters, Vol. 272, 1-2, July 30, pp. 148-157.MantleDensity
DS201012-0052
2010
Simon, N.S.C.Beuchert, M.J., Podladchikov, Y.Y., Simon, N.S.C., Rupke, L.H.Modeling of craton stability using a viscoelastic rheology.Journal of Geophysical Research, Vol. 115, B 11, B11413.MantleRheology
DS201012-0682
2010
Simon, N.S.C.Semprich, J., Simon, N.S.C., Podladchikov, Y.Y.Density variations in the thickened crust as a function of pressure, temperature and composition.International Journal of Earth Sciences, Vol. 99, 7, pp. 1487-1510.MantleGeophysics
DS201412-0793
2014
Simon, N.S.C.Semprich, J., Simon, N.S.C.Inhibited eclogitization and consequences for geophysical rock properties and delamination models: constraints from cratonic lower crustal xenoliths.Gondwana Research, Vol. 25, pp. 668-684.MantleGeophysics - eclogites
DS2001-1080
2001
Simon, R.Simon, R., Wright, Kgaswane, KwadibaThe structure of the transition zone and uppermost lower mantle below and around the Kaapvaal Craton.Slave-Kaapvaal Workshop, Sept. Ottawa, 6p. abstractSouth AfricaTectonics
DS2002-1490
2002
Simon, R.E.Simon, R.E., Wright, C., Kgaswanr, E.M., Kwadiba, M.T.O.The P wavespeed structure below and around the Kaapvaal Craton to depths of 800Geophysical Journal International, Vol. 151, 1, pp. 132-145.South AfricaGeophysics - seismics, Mining induced tremors
DS2002-1741
2002
Simon, R.E.Wright, C., Kwadiba, M.T., Kgaswane, E.M., Simon, R.E.The structure of the crust and upper mantle to depths of 320 km beneath the KaapvaalJournal of African Earth Sciences, Vol. 35, 4, pp. 477-88.South AfricaGeophysics - seismics, Core mantle boundary
DS2003-0766
2003
Simon, R.E.Kwadiba, M.T., Wright, C., Kgaswane, E.M., Simon, R.E., Nguuri, T.K.Pn arrivals and lateral variations of Moho geometry beneath the Kaapvaal cratonLithos, Vol. 71, 2-4, pp. 393-411.South AfricaGeophysics - seismics, tectonics
DS2003-1280
2003
Simon, R.E.Simon, R.E., Wright, C., Kwadiba, M.T., Kgaswane, E.M.Mantle structure and composition to 800 km depth beneath southern Africa andLithos, Vol. 71, 2-4, pp. 353-367.South AfricaGeophysics - seismics, tectonics
DS2003-1281
2003
Simon, R.E.Simon, R.E., Wright, C., Kwadiba, M.T.O., Kgaswane, E.M.The structure of the upper mantle and transition zone beneath southern Africa fromSouth African Journal of Science, South AfricaBlank
DS2003-1500
2003
Simon, R.E.Wright, C., Kgaswane, E.M., Kwadiba, M.T., Simon, R.E., Nguuri, T.K., McRaeSouth African seismicity, April 1997 to April 1999 and regional variations in the crustLithos, Vol. 71, 2-4, pp. 369-392.South AfricaGeophysics - seismics, tectonics
DS200412-1075
2003
Simon, R.E.Kwadiba, M.T., Wright, C., Kgaswane, E.M., Simon, R.E., Nguuri, T.K.Pn arrivals and lateral variations of Moho geometry beneath the Kaapvaal craton.Lithos, Vol. 71, 2-4, pp. 393-411.Africa, South AfricaGeophysics - seismics, tectonics
DS200412-1832
2003
Simon, R.E.Simon, R.E., Wright, C., Kwadiba, M.T., Kgaswane, E.M.Mantle structure and composition to 800 km depth beneath southern Africa and surrounding oceans from broadband body waves.Lithos, Vol. 71, 2-4, pp. 353-367.Africa, South AfricaGeophysics - seismics, tectonics
DS200412-1833
2003
Simon, R.E.Simon, R.E., Wright, C., Kwadiba, M.T.O., Kgaswane, E.M.The structure of the upper mantle and transition zone beneath southern Africa from broad band body waves.South African Journal of Science, Vol. 99, 11/12, pp. 577-583.Africa, South AfricaGeophysics - seismics, tectonics
DS200412-2146
2003
Simon, R.E.Wright, C., Kgaswane, E.M., Kwadiba, M.T., Simon, R.E., Nguuri, T.K., McRae, S.R.South African seismicity, April 1997 to April 1999 and regional variations in the crust and uppermost mantle of the Kaapvaal craLithos, Vol. 71, 2-4, pp. 369-392.Africa, South AfricaGeophysics - seismics, tectonics
DS200412-2148
2004
Simon, R.E.Wright, C., Kwadiba, M.T.O., Simon, R.E., Kgaswane, E.M., Nguuri, T.K.Variations in the thickness of the crust of the Kaapvaal craton, and mantle structure below southern Africa.Earth Planets and Space, Vol. 56, 2, pp. 125-138. Ingenta 1043471077Africa, South AfricaTectonics, Gondwana, boundary, discontinuities
DS2000-0072
2000
Simon, S.B.Beckett, J.R., Simon, S.B., Stolper, E.The partitioning of Sodium between melilite and liquid: pt. 2 Applications to Type B inclusions carb. chondritesGeochimica et Cosmochimica Acta, Vol. 64, No. 14, Jul. pp. 2519-34.GlobalPetrology - experimental, sodium, Melilite
DS200612-1308
2006
Simon, S.B.Simon, S.B., Grossman, L.A comparative study of melilite and fassaite in types B1 and B2 refractory inclusions.Geochimica et Cosmochimica Acta, Vol. 70, 3, Feb. 1, pp. 780-798.TechnologyPetrology
DS201801-0064
2017
Simon, S.J.Simon, S.J., Wei, C.T., Viladkar, S.G., Ellmies, R., Soh, Tamech, L.S., Yang, H., Vatuva, A.Metamitic U rich pyrochlore from Epembe sovitic carbonatite dyke, NW Namibia.Carbonatite-alkaline rocks and associated mineral deposits , Dec. 8-11, abstract p. 12.Africa, Namibiadeposit - Epembe

Abstract: The Epembe carbonatite dyke is located about 80 km north of Opuwo, NW Namibia. The 10 km long dyke is dominated by massive and banded sövitic carbonatite intrusions. Two distinct type of sövite have been recognized: (1) coarse-grained light grey Sövite I which is predominant in brecciated areas and (2) medium- to fine-grained Sövite II which hosts notable concentrations of pyrochlore and apatite. The contact between the carbonatite and basement gneisses is marked by K-feldspar fenite. The pyrochlore chemistry at Epembe shows a compositional trend from primary magmatic Ca-rich pyrochlore toward late hydrothermal fluid enriched carbonatite phase, giving rise to a remarkable shift in chemical composition and invasion of elements such as Si, U, Sr, Ba, Th and Fe. Enrichment in elements like U, Sr and Th lead to metamictization, alteration and A-site vacancy. It is therefore suggested that the carbonatite successive intrusive phases assimilated primary pyrochlore leading to extreme compositional variation especially around the rims of the pyrochlore. The genesis of the Epembe niobium deposit is linked to the carbonatite magmatism but the mechanism that manifested such niobium rich rock remains unclear and might be formed as a result of cumulate process and/or liquid immiscibility of a carbonate-silicate pair.
DS201812-2790
2018
Simonatti, A.Cimen, O., Kuebler, C., Monaco, B., Simonetti, S.S., Corcoran, L., Chen, W., Simonatti, A.Boron, carbon, oxygen and radiogenic isotope investigation of carbonatite from the Miaoya complex, central China: evidences for late stage REE hydrothermal event and mantle source heterogeneity.Lithos, Vol. 322, pp. 225-237.Chinadeposit - Miaoya

Abstract: The Miaoya carbonatite complex (MCC) is located within the southern edge of the Qinling orogenic belt in central China, and is associated with significant rare earth element (REE) and Nb mineralization. The MCC consists of syenite and carbonatite that were emplaced within Neo- to Mesoproterozoic-aged supracrustal units. The carbonatite intruded the associated syenite as stocks and dikes, and is mainly composed of medium- to fine-grained calcite and abundant REE-bearing minerals. Carbonatite melt generation and emplacement within the MCC occurred during the Silurian (at ~440?Ma), and was subsequently impacted by a late-stage hydrothermal event (~232?Ma) involving REE-rich fluids/melt. This study reports trace element and stable (B, C, and O) and radiogenic (Nd, Pb, and Sr) isotope data for the MCC carbonatite, and these have been subdivided into three groups that represent different REE contents, interpreted as varying degrees of hydrothermal interaction. Overall, the group of carbonatites with the lowest enrichment in LREEs (i.e., least affected by hydrothermal event) is characterized by d11B values that vary between -7 (typical asthenospheric mantle) and?+?4‰; d11B values and B abundances (~0.2 to ~1?ppm) do not correlate with LREE contents. The Sm-Nd and Pb-Pb isotope systems have both been perturbed by the late-stage, REE-rich hydrothermal activity and corroborate open-system behavior. Contrarily, initial 87Sr/86Sr ratios (vary between ~0.70355 and 0.70385) do not correlate significantly with both LREEs and Sr abundances, nor with initial 143Nd/144Nd ratios. The late-stage hydrothermal event overprinted the Nd and Pb isotope compositions for most of the carbonatite samples examined here, whereas a majority of the samples preserve their variable B and Sr isotope values inherited from their mantle source. The B and Sr isotope data for carbonatites exhibiting the least LREE enrichment correlate positively and suggest carbonatite melt generation from a heterogenous upper mantle source that records the input of recycled crustal material. This finding is consistent with those previously reported for young (<300?Ma old) carbonatites worldwide.
DS1860-0284
1877
Simonds, F.W.Simonds, F.W.The Geology of Ithaca, New York and the VicinityBsc. Thesis, Cornell University, ALSO Publishing BY RIVERSIDE PRESS, CAMBRIDGE, 49P.United States, New YorkRegional Geology
DS2003-1282
2003
Simonenko, V.A.Simonenko, V.A., Shishkin, N.I.Cumulation of seismic waves during formation of kimberlite pipesJournal of Applied Mechanics and Technical Physics - Kluwer Publ. Ingenta, Vol. 44, 6, pp. 760-69.RussiaGeophysics - seismics, genesis
DS200412-1834
2003
Simonenko, V.A.Simonenko, V.A., Shishkin, N.I.Cumulation of seismic waves during formation of kimberlite pipes.Journal of Applied Mechanics and Technical Physics - Kluwer Publ. Ingenta 1034481090, Vol. 44, 6, pp. 760-69.RussiaGeophysics - seismics, genesis
DS1985-0108
1985
Simonet, G.Carre, C., Censier, C., Simonet, G.La Documentation de Base sur la Geologie de la Republique CentrafricainePangea, December pp. 17-25.Central African RepublicDiamonds P. 22, Mineral Resources Database
DS200512-0882
2005
Simoneti, A.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
DS200912-0698
2009
Simoneti, A.Smart, K.A., Chacko, T., Heaman, L.M., Simoneti, A.Origin of diamond rich, high MGO eclogite xenoliths from the Jericho kimberlite, Nuanvut.GAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyCanada, NunavutDeposit - Jericho geochemistry
DS200812-0250
2007
Simonett, A.Creighton, S., Stachel, T., McLean, H., Muehlenbachs, K., Simonett, A., Eichenberg, D., Luth, R.Diamondiferous peridotitic microxenoliths from the Diavik diamond mine, NT.Contributions to Mineralogy and Petrology, Vol.155, 5, pp. 541-554.Canada, Northwest TerritoriesDeposit - Diavik, mineral inclusions, chemistry
DS201112-0160
2011
SimonettiChakmouradian, A.R., Bohm, Coeslan, Mumin, Reguir, Demeny, Simonetti, Kressall, Martins, Kamenov, Creaser, LepekhinaPostorogenic carbonatites: more abundant than we realize and more important than given credit for.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.17-19.Canada, ManitobaCinder Lake, Eden Lake, Paint Lake
DS201112-0161
2011
SimonettiChakmouradian, A.R., Bohm, Coeslan, Mumin, Reguir, Demeny, Simonetti, Kressall, Martins, Kamenov, Creaser, LepekhinaPostorogenic carbonatites: more abundant than we realize and more important than given credit for.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.17-19.Canada, ManitobaCinder Lake, Eden Lake, Paint Lake
DS2003-1227
2003
Simonetti, . A.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
DS1991-1586
1991
Simonetti, A.Simonetti, A., Bell, K.Isotopic investigation of the Lake Chilwa carbonatite Complex, Malawi:implications for the origin of carbonatite magmasGeological Association of Canada (GAC)/Mineralogical Association of Canada/Society Economic, Vol. 16, Abstract program p. A114MalawiGeochronology, Carbonatite
DS1992-1407
1992
Simonetti, A.Simonetti, A., Bell, K.neodymium, lead, and Strontium isotopic dat a Napak carbonatite -nephelinite centre, eastern Uganda: implications for crustal assimilation and fractional crystalizationEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p.329UgandaCarbonatite, Nephelinite
DS1993-1468
1993
Simonetti, A.Simonetti, A., Bell, K.Isotopic disequilibrium in clinopyroxenes from nephelinitic lavas, Napakvolcano, eastern Uganda.Geology, Vol. 21, No. 3, March pp. 243-246.UgandaTectonics -rifting, Nephelinites
DS1994-0139
1994
Simonetti, A.Bell, K., Simonetti, A.Mantle signatures in carbonatitesGeological Association of Canada (GAC) Abstract Volume, Vol. 19, p.MantleCarbonatite, Geophysics
DS1994-1606
1994
Simonetti, A.Simonetti, A.Comparative neodymium, lead, and Strontium isotopic study of alkaline complexes from East Africa and India: melt dynamics.Carleton University, Ph.d. thesisAfrica, India, MalawiAlkaline complexes, Thesis
DS1994-1607
1994
Simonetti, A.Simonetti, A.Comparative neodymium, lead and Strontium isotopic study of alkaline complexes from East Africa and India: mantle source...Ph.d. Thesis, University of of Ottawa, Uganda, Kenya, Malawi, IndiaGeochronology, Deposit - Napak, Mt. Elgon, Chilwa, Amba Dongar
DS1994-1608
1994
Simonetti, A.Simonetti, A., Bell, K.Isotopic and geochemical investigation of the Chilwa Island carbonatiteComplex, Malawi: evidence depleted..Journal of Petrology, Vol. 35, No. 6, Dec. pp. 1597-1622.MalawiCarbonatite, Geochemistry
DS1994-1609
1994
Simonetti, A.Simonetti, A., Bell, K.neodymium, lead and Strontium isotopic dat a from the Napak carbonatite-nephelinite eastern Uganda: an example of open system crystal fractionation.Contribution Mineralogy and Petrology, Vol. 116, No. 3, pp. 356-366.UgandaCarbonatite, Deposit -Napak
DS1994-1610
1994
Simonetti, A.Simonetti, A., Bell, K.neodymium, lead, and Strontium isotopic dat a from the Napak carbonatite-nephelinite eastern Uganda- an example of open system crystal fractionation.Contributions to Mineralogy and Petrology, Vol. 115, No.3, January pp. 356-366.UgandaCarbonatite, Geochronology
DS1995-1758
1995
Simonetti, A.Simonetti, A., Bell, K.neodymium, lead and Strontium dat a from Mountain Elgon volcano, eastern UgAnd a -western Kenya:implications for origin lavasLithos, Vol. 36, No. 2, Nov. 1, pp. 141-Uganda, KenyaGeochronology, Nephelinite lavas
DS1995-1759
1995
Simonetti, A.Simonetti, A., Bell, K.neodymium, lead, and Strontium isotope systematics of fluorite at the Amba Dongar carbonatite Complex, India: fluid mixing...Economic Geology, Vol. 90, No. 7, Nov. pp. 2018-2027.IndiaCarbonatite, Geochronology, hydrotherma, crust, Deposit -Amba Dongar
DS1995-1760
1995
Simonetti, A.Simonetti, A., Bell, K.neodymium, lead, Strontium dat a from Mt. Elgon volcano, east UgAnd a -West Kenya-implications for evolution of nephelinitesLithos, Vol. 36, No.2, Nov. 1, pp. 141-Uganda, KenyaNephelinite
DS1995-1761
1995
Simonetti, A.Simonetti, A., Bell, K., Viladkar, S.G.Isotopic dat a from the Amba Donga carbonatite Complex, west-central India:evidence for enriched mantle sourceChemical Geology, Vol. 122, pp. 185-198.IndiaCarbonatite, geochronology, Deposit -Amba Donga
DS1996-0110
1996
Simonetti, A.Bell, K., Simonetti, A.Carbonatitic magmatism and plume activity: implications from the neodymium lead and Sr isotope systematics of OldoinyoJournal of Petrology, Vol. 37, No. 6, Dec. pp. 1321-39.TanzaniaCarbonatite, Deposit -Oldoinyo Lengai
DS1996-1314
1996
Simonetti, A.Simonetti, A., Shore, M., Bell, K.Diopside phenocrysts from nephelinite lavas, Napak volcano, eastern Uganda:evidence for magma mixing.Canadian Mineralogist, Vol. 34, pt. 2, April pp. 411-422.UgandaAlkaline rocks, metamorphism
DS1996-1479
1996
Simonetti, A.Viladkar, S.G., Simonetti, A.Amba Dongar sub-volcanic diatreme: a review of field, petrological and geochemical aspects.International Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 400.IndiaCarbonatite, Deposit -Amba Dongar
DS1997-1045
1997
Simonetti, A.Simonetti, A., Bell, K.Trace and rare earth element geochemistry of the June 1993 natrocarbonatitelavas, Oldoinyo Lengai....Journal of Volcanology and Geothermal Research, Vol. 75, No. 1-2, pp. 89-106.TanzaniaCarbonatite magmas, Deposit - Oldoinyo Lengai
DS1997-1046
1997
Simonetti, A.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
DS1998-1352
1998
Simonetti, A.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
DS2001-0100
2001
Simonetti, A.Bell, K., Simonetti, A.A close look at magma chamber dynamics - in situ Sr Sr measurements of igneous minerals from la MC ICP MS.Geological Association of Canada (GAC) Annual Meeting Abstracts, Vol. 26, p.12, abstract.Quebec, FinlandCarbonatite, strontium, Oka, Sillinjarvi
DS2001-0112
2001
Simonetti, A.Bizarro, M., Simonetti, A., Kurszlaukis, S., StevensonStrontium isotopic compositions of apatite and calcite from carbonatites (Sarfartoq region) using la Mc ICP MSGeological Association of Canada (GAC) Annual Meeting Abstracts, Vol. 26, p.14, abstract.GreenlandMantle process - insights, Carbonatite
DS2001-1032
2001
Simonetti, A.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
DS2002-0161
2002
Simonetti, A.Bizarro, M., Simonetti, A., Stevenson, R.K., David, J.Hf isotope evidence for a hidden mantle reservoirGeology, Vol. 30,9,Sept. pp. 771-4.Greenland, North America, LabradorCarbonatite, kimberlites, Archean - geochronology
DS2002-0162
2002
Simonetti, A.Bizzarro, M., Simonetti, A., Stevenson, R.K., David, J.Hf isotope evidence for a hidden mantle reservoirGeology, Vol. 30, 9, Sept. pp. 771-4.MantleGeochronology
DS2002-1420
2002
Simonetti, A.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
DS2003-1226
2003
Simonetti, A.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
DS200412-1756
2003
Simonetti, A.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
DS200612-0545
2005
Simonetti, A.Hartlaub, R.P., Chacko, T., Heaman, L.M., Creaser, R.A., Ashton, K.E., Simonetti, A.Ancient (Meso-Paleoarchean) crust in the Rae Province, Canada: evidence from Sm-Nd and U-Pb constraints.Precambrian Research, Vol. 141, 3-4, Nov. 20, pp. 137-153.Canada, Saskatchewan, Alberta, Northwest TerritoriesGeochronology, crustal recycling
DS200612-0546
2006
Simonetti, A.Hartlaub, R.P., Heaman, L.M., Simonetti, A., Bohm, C.O.Relicts of Earth's crust: U Pb, Lu Hf and morphological characteristics of > 3.7 Ga detrital zircon of the western Canadian Shield.Geological Society of America, Processes on the Earth, Special Paper 405, Chapter 5.CanadaGeochronology
DS200612-1240
2005
Simonetti, A.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
Simonetti, A.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
DS200712-1001
2007
Simonetti, A.Smart, K.A., Heaman, L.M., Chacko, T., Simonetti, A., Kopylova, M.Mineral chemistry and clinopyroxene Sr Pb isotope compositions of mantle eclogite xenoliths from the Jericho kimberlite, Nunavut.Geological Association of Canada, Gac-Mac Yellowknife 2007, May 23-25, Volume 32, 1 pg. abstract p.76.Canada, NunavutMineral chemistry
DS200812-0163
2008
Simonetti, A.Burwash, R.A., Cavell, P., Simonetti, A., Chacko, T., Luth, R.W., Nelson, D.B.LA MC ICP MS dating of zircon using petrographic thin sections: an investigation of buried Archean basement in southern Alberta.Goldschmidt Conference 2008, Abstract p.A123.Canada, AlbertaGeochronology
DS200812-1082
2008
Simonetti, A.Smart, K.A., Heaman, L.M., Chocko, T., Simonetti, A., Kopylova, M., Mah, D., Daniels, D.The origin of diamond rich high MGO eclogite xenoliths from the Jericho kimberlite, Nunavut.Northwest Territories Geoscience Office, p. 56-57. abstractCanada, NunavutDeposit - Jericho
DS200812-1154
2008
Simonetti, A.Tappe, S., Steenfelt, A., Heaman, L.M., Romer, R.J., Simonetti, A., Muehlenbachs, K.The alleged carbonatitic kimberlitic melt continuum: contrary evidence from West Greenland.Goldschmidt Conference 2008, Abstract p.A934.Europe, GreenlandDeposit - Safartoq
DS200912-0046
2009
Simonetti, A.Bell, K., Simonetti, A.Source of parental melts to carbonatites - critical isotopic constraints.Mineralogy and Petrology, in press availableGlobalMantle metamorphism
DS200912-0047
2009
Simonetti, A.Bell, K., Simonetti, A.Source of parental melts to carbonatites - critical isotopic constraints.Mineralogy and Petrology, In press available, 13p.MantleMelting - mantle metasomatism
DS200912-0183
2009
Simonetti, A.Doornbos, C., Heaman, L.M., Doupe, J.P., England, J., Simonetti, A., Lejeunesse, P.The first integrated use of in situ U Pb geochronology and geochemical analyses to determine long distance transport of glacial erratics from maIn land Canada into western Arctic Archipelgo.Canadian Journal of Earth Sciences, Vol. 46, 2, pp. 101-122.Canada, Melville PeninsulaGeochronology - western Arctic Archipelago
DS200912-0322
2009
Simonetti, A.Hunt, L., Stachel, T., Armstrong, J.P., Simonetti, A.The Diamondiferous lithospheric mantle underlying the eastern Superior Craton: evidence from mantle xenoliths from the Renard kimberlite, Quebec.GAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyCanada, QuebecDeposit - Renard
DS200912-0701
2009
Simonetti, A.Smart, K.A., Heaman, L.M., Chacko, T., Simonetti, A., Kopylova, M., Mah, D., Daniels, D.The origin of hig MgO diamond eclogites from the Jericho kimberlite, Canada.Earth and Planetary Science Letters, Vol. 284, 3-4, pp. 527-537.Canada, NunavutDeposit - Jericho
DS200912-0745
2009
Simonetti, A.Tappe, S., Heaman, L.M., Romer, R.L., Steenfelt, A., Simonetti, A., Muehlenbach, K., Stracke, A.Quest for primary carbonatite melts beneath cratons: a West Greenland perspective.Goldschmidt Conference 2009, p. A1314 Abstract.Europe, GreenlandCarbonatite
DS200912-0746
2009
Simonetti, A.Tappe, S., Heaman, L.M., Smart, K.A., Muehlenbachs, K., Simonetti, A.First results from Greenland eclogite xenoliths: evidence for an ultra depleted peridotitic component within the North Atlantic craton mantle lithosphere.GAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyEurope, GreenlandMelting
DS200912-0747
2009
Simonetti, A.Tappe, S., Sleenfelt, A., Heaman, L.M., Simonetti, A.The newly discovered Jurassic Tikusaaq carbonatite allikite occurrence, West Greenland, and some remarks on carbonatite kimberlite relationships.Lithos, in press availableEurope, GreenlandPetrology
DS201012-0047
2010
Simonetti, A.Bell, K., Simonetti, A.Source of parental melts to carbonatites - critical isotopic constraints.Mineralogy and Petrology, Vol. 98, 1-4, pp. 77-89.MantleCarbonatite
DS201012-0257
2010
Simonetti, A.Gwalani, L.G., Moore, K., Simonetti, A.Carbonatites, alkaline rocks and the mantle: a special issue dedicated to Keith Bell.Mineralogy and Petrology, Vol. 98, 1-4, pp. 5-10.MantleCarbonatite
DS201112-1029
2011
Simonetti, A.Tappe, S., Smart, K.A., Pearson, D.G., Steenfelt, A., Simonetti, A.Craton formation in late Archean subduction zones revealed by first Greenland eclogites.Geology, Vol. 39, 12, pp. 1103-1106.Europe, GreenlandMelting , Nunatak-1390
DS201212-0166
2012
Simonetti, A.Donahue, P.H., Simonetti, A., Neal, C.R.Chemical characteristics of natural ilmenite: a possible new reference material.Geostandards and Geoanalytical Research, Vol. 36, 1, pp. 61-73.Asia, Solomon IslandsMalaita alnoite pipes
DS201212-0320
2012
Simonetti, A.Hunt, L., Stachel, T., Grutter, H., Armstrong, J., McCandless, T.E., Simonetti, A., Tappe, S.Small mantle fragments from the Renard kimberlites, Quebec: powerful recorders of mantle lithosphere formation and modification beneath the eastern Superior Craton.Journal of Petrology, Vol. 53, 8, pp. 1597-1635.Canada, QuebecDeposit - Renard
DS201212-0719
2012
Simonetti, A.Tappe, S., Simonetti, A.Combined U-Pb geochronology and Sr-Nd isotope analysis of the Ice River perovskite standard, with implications for kimberlite and alkaline rock petrogenesis.Chemical Geology, Vol. 304-305, pp. 10-17.TechnologyGeochronology
DS201312-0149
2013
Simonetti, A.Chen, W., Simonetti, A.In situ determination of major and trace elements in calcite and apatite, and U-Pb ages of apatite from the Oka carbonatite complex: insights into a complex crystallization history.Chemical Geology, Vol. 353, pp. 151-172.Canada, QuebecDeposit - Oka
DS201312-0150
2013
Simonetti, A.Chen, Wei, Simonetti, A.PB isotope evidence from the Oka carbonatite complex for a distinct mantle reservoir.Goldschmidt 2013, AbstractCanada, QuebecCarbonatite
DS201412-0841
2014
Simonetti, A.Smart, K.A., Chacko, T., Simonetti, A., Sharp, Z.D., Heaman, L.M.A record of Paleoproterozoic subduction preserved in the northern Slave cratonic mantle: Sr-Pb-O isotope and trace element investigations of eclogite xenoliths from the Jericho and Muskox kimberlites.Journal of Petrology, Vol. 55, 3, pp. 549-583.Canada, NunavutDeposit - Jericho, Muskox
DS201611-2133
2016
Simonetti, A.Potter, N.J., Kamenetsky, V.S., Simonetti, A., Goemann, K.Different types of liquid immiscibility in carbonatite magmas: a case study of the Oldoinyo Lengai 1993 lava and melt inclusions.Chemical Geology, in press available 9p.Africa, TanzaniaDeposit - Oldoinyo Lengai

Abstract: Oldoinyo Lengai is situated within the Gregory Rift Valley (northern Tanzania) and is the only active volcano erupting natrocarbonatite lava. This study investigates the texture and mineralogy of the June 1993 lava at Oldoinyo Lengai, and presents petrographic evidence of liquid immiscibility between silicate, carbonate, chloride, and fluoride melt phases. The 1993 lava is a porphyritic natrocarbonatite consisting of abundant phenocrysts of alkali carbonates, nyerereite and gregoryite, set in a quenched groundmass, composed of sodium carbonate, khanneshite, Na-sylvite and K-halite, and a calcium fluoride phase. Dispersed in the lava are silicate spheroids (< 2 mm) with a cryptocrystalline silicate mineral assemblage wrapped around a core mineral. We have identified several textural features preserved in the silicate spheroids, melt inclusions, and carbonatite groundmass that exhibit evidence of silicate-carbonate, carbonate-carbonate and carbonate-halide immiscibility. Rapid quenching of the lava facilitated the preservation of the end products of these liquid immiscibility processes within the groundmass. Textural evidence (at both macro- and micro-scales) indicates that the silicate, carbonate, chloride and fluoride phases of the lava unmixed at different stages of evolution in the magmatic system.
DS201611-2141
2016
Simonetti, A.Smart, K., Tappe, S., Simonetti, A., Harris, C.Tectonic significance and redox state of Paleoproterozoic eclogite and pyroxenite components in the Slave cratonic mantle lithosphere, Voyageur kimberlite, Arctic Canada.Chemical Geology, in press available 22p.Canada, NunavutDeposit - Voyageur
DS201612-2303
2016
Simonetti, A.Hulett, S.R.W., Simonetti, A., Rasbury, E.T., Hemming, N.G.Recyclying of subducted crustal components into carbonatite melts revealed by boron isotopes.Nature Geoscience, Nov. 7, on line 6p.GlobalCarbonatite

Abstract: The global boron geochemical cycle is closely linked to recycling of geologic material via subduction processes that have occurred over billions of years of Earth’s history. The origin of carbonatites, unique melts derived from carbon-rich and carbonate-rich regions of the upper mantle, has been linked to a variety of mantle-related processes, including subduction and plume-lithosphere interaction. Here we present boron isotope (d11B) compositions for carbonatites from locations worldwide that span a wide range of emplacement ages (between ~40 and ~2,600?Ma). Hence, they provide insight into the temporal evolution of their mantle sources for ~2.6 billion years of Earth’s history. Boron isotope values are highly variable and range between -8.6 and +5.5, with all of the young (<300?Ma) carbonatites characterized by more positive d11B values (>-4.0‰ whereas most of the older carbonatite samples record lower B isotope values. Given the d11B value for asthenospheric mantle of -7 ± 1‰ the B isotope compositions for young carbonatites require the involvement of an enriched (crustal) component. Recycled crustal components may be sampled by carbonatite melts associated with mantle plume activity coincident with major tectonic events, and linked to past episodes of significant subduction associated with supercontinent formation.
DS201701-0015
2016
Simonetti, A.Hulett, S.R.W., Simonetti, A., Rasbury, E.T., Hemming, G.Recycling of subducted crustal components into carbonatite melts revealed by boron isotopes.Nature Geoscience, Vol. 9, pp. 904-908.MantleMagmatism

Abstract: The global boron geochemical cycle is closely linked to recycling of geologic material via subduction processes that have occurred over billions of years of Earth’s history. The origin of carbonatites, unique melts derived from carbon-rich and carbonate-rich regions of the upper mantle, has been linked to a variety of mantle-related processes, including subduction and plume-lithosphere interaction. Here we present boron isotope (d11B) compositions for carbonatites from locations worldwide that span a wide range of emplacement ages (between ~40 and ~2,600?Ma). Hence, they provide insight into the temporal evolution of their mantle sources for ~2.6 billion years of Earth’s history. Boron isotope values are highly variable and range between -8.6‰ and +5.5‰, with all of the young (<300?Ma) carbonatites characterized by more positive d11B values (>-4.0‰), whereas most of the older carbonatite samples record lower B isotope values. Given the d11B value for asthenospheric mantle of -7 ± 1‰, the B isotope compositions for young carbonatites require the involvement of an enriched (crustal) component. Recycled crustal components may be sampled by carbonatite melts associated with mantle plume activity coincident with major tectonic events, and linked to past episodes of significant subduction associated with supercontinent formation.
DS201707-1357
2017
Simonetti, A.Potter, N.J., Kamenetsky, V.S., Simonetti, A., Goemann, K.Different types of liquid immiscibility in carbonatite magmas: a case stufy of the Oldoinyo Lengai 1993 lava and melt inclusions.Chemical Geology, Vol. 455, pp. 376-384.Africa, Tanzaniadeposit - Oldoinyo Lengai

Abstract: Oldoinyo Lengai is situated within the Gregory Rift Valley (northern Tanzania) and is the only active volcano erupting natrocarbonatite lava. This study investigates the texture and mineralogy of the June 1993 lava at Oldoinyo Lengai, and presents petrographic evidence of liquid immiscibility between silicate, carbonate, chloride, and fluoride melt phases. The 1993 lava is a porphyritic natrocarbonatite consisting of abundant phenocrysts of alkali carbonates, nyerereite and gregoryite, set in a quenched groundmass, composed of sodium carbonate, khanneshite, Na-sylvite and K-halite, and a calcium fluoride phase. Dispersed in the lava are silicate spheroids (< 2 mm) with a cryptocrystalline silicate mineral assemblage wrapped around a core mineral. We have identified several textural features preserved in the silicate spheroids, melt inclusions, and carbonatite groundmass that exhibit evidence of silicate-carbonate, carbonate-carbonate and carbonate-halide immiscibility. Rapid quenching of the lava facilitated the preservation of the end products of these liquid immiscibility processes within the groundmass. Textural evidence (at both macro- and micro-scales) indicates that the silicate, carbonate, chloride and fluoride phases of the lava unmixed at different stages of evolution in the magmatic system.
DS201707-1369
2017
Simonetti, A.Smart, K.A., Tappe, S., Simonetti, A., Simonetti, S.S., Woodland, A.B., Harris, C.Tectonic significance and redox state of Paleoproterozoic eclogite and pyroxenite components in the Slave cratonic mantle lithosphere, Voyager kimberlite, Arctic Canada.Chemical Geology, Vol. 455, pp. 98-119.Canadadeposit - Voyager

Abstract: Mantle-derived eclogite and pyroxenite xenoliths from the Jurassic Voyageur kimberlite on the northern Slave craton in Arctic Canada were studied for garnet and clinopyroxene major and trace element compositions, clinopyroxene Pb and garnet O isotopic compositions, and garnet Fe3 +/SFe contents. The Voyageur xenoliths record a wide range of pressures, but are cooler compared to mantle xenoliths derived from the nearby, coeval Jericho kimberlite. The CaO, TiO2 and Zr contents of Voyageur eclogites increase with depth, which is also observed in northern Slave peridotite xenoliths, demonstrating ‘bottom-up’ metasomatic processes within cratonic mantle lithosphere. The Voyageur eclogites have positive Eu anomalies, flat HREEN patterns, and major element compositions that are consistent with ultimate origins from basaltic and gabbroic protoliths within oceanic lithosphere. Clinopyroxene Pb isotope ratios intercept the Stacey-Kramers two-stage terrestrial Pb evolution curve at ca. 2.1 Ga, and form an array towards the host kimberlite, indicating isotopic mixing. The 2.1 Ga eclogite formation age broadly overlaps with known Paleoproterozoic subduction and collision events that occurred along the western margin of the Slave craton. Unlike the eclogites, the Voyageur pyroxenites contain garnet with distinctive fractionated HREEN, sinusoidal REE patterns of calculated bulk rocks, and clinopyroxene with 206Pb/204Pb ratios that intercept the Stacey-Kramers curve at 1.8 Ga. This suggests a distinct origin as Paleoproterozoic high-pressure mantle cumulates. However, the pyroxenite Pb isotope ratios fall within the eclogite array and could also be explained by protoliths formation at ca. 2.1 Ga followed by minor isotopic mixing during mantle metasomatism. Thus, an alternative scenario involves pyroxenite formation within the mantle section of Paleoproterozoic oceanic lithosphere followed by variable metasomatism after incorporation into cratonic mantle lithosphere. This model allows for a linked petrogenesis of the Voyageur eclogites (crust) and pyroxenites (mantle) as part of the same subducting oceanic slab. Oxygen fugacity determinations for one pyroxenite and ten eclogite xenoliths show a range of 3 log units, from - 4.6 to - 1.6 ?FMQ, similar to the range observed for nearby Jericho and Muskox eclogites (?FMQ - 4.2 to - 1.5). Importantly, the northern Slave eclogite and pyroxenite mantle components are highly heterogeneous in terms of redox state provided that they range from reduced to oxidized relative to Slave peridotite xenoliths. Moreover, the Voyageur eclogites do not exhibit any trend between oxidation state and equilibration depth, which contrasts with the downward decrease in fO2 shown by Slave and worldwide cratonic peridotite xenoliths. Our investigation of mantle eclogite and pyroxenite fO2 reinforces the important influence of recycled mafic components in upper mantle processes, because their high and variable redox buffering capacity strongly controls volatile speciation and melting relations under upper mantle conditions.
DS201709-2054
2017
Simonetti, A.Smart, K., Tappe, S., Simonetti, A., Simonetti, S., Woodland, A., Harris, C.The redox state of mantle eclogites.Goldschmidt Conference, abstract 1p.Mantleeclogites

Abstract: Mantle-derived eclogite xenoliths are key for studying the evolution of the cratonic lithosphere, because geochemical evidence suggests that they typically represent fragments of Archean and Proterozoic oceanic lithosphere [1]. Recently, it has been suggested that eclogite xenoliths can serve as redox sensors of the Precambrian upper mantle using V/Sc as a redox proxy [2]. However, metasomatism can change the original oxidation state of the cratonic mantle [3], thereby limiting its use for monitoring mantle redox evolution. Circa 1.8–2.2 Ga eclogite xenoliths erupted with Jurassic kimberlites of the northern Slave craton have geochemical features that indicate oceanic crust protoliths [4, 5]. Such Paleoproterozoic ages are common for Slave craton mantle eclogites [6], linking eclogite formation with 1.9 Ga subduction-collision events at the western craton margin. The eclogites studied here have highly variable Fe3+/SFe (0.019 – 0.076 ±0.01), with logfO2 (?FMQ-4 to +2 ±0.5) that are both relatively oxidized and reduced compared to Slave mantle peridotite xenoliths [3]. Also, eclogite fO2 positively correlates with some indicies of metasomatism, such as elevated TiO2 in garnet. In addition to considering the time gap between eclogite formation and kimberlite eruption, the highly variable fO2–depth systematics of the eclogites studied here illustrate the drawbacks of using averaged eclogite fO2 to define the redox evolution of the upper mantle. Despite this, the ca. 2 Ga northern Slave craton eclogites have an average depth-corrected logfO2 of ?FMQ-0.5±1.3 (1s) that overlaps with modern MORB, and complies with the upper mantle redox evolution trend predicted using V/Sc ratios of mantlederived melts [2]. However, given the debate around the secuarity of mantle redox [7], further research into the suitability of mantle eclogites as redox sensors is warranted.
DS201801-0065
2017
Simonetti, A.Simonetti, A., Kuebler, C.Nd, Sr, Pb and B isotopic investigation of carbonatite/alkaline centers in west central India: insights into plume driven vs lithospheric controlled magmatism.Carbonatite-alkaline rocks and associated mineral deposits , Dec. 8-11, abstract p. 17.Indiacarbonatites

Abstract: The exact origin of carbonatite magmas remains debatable as there are two main hypothesis proposed; one relates magmatism to asthenospheric upwellings and/or mantle plumes, whereas the other argues for generation from metasomatized lithosphere. However, proponents of the latter rarely describe in detail the origin of the metasomatic agents required to generate the high concentrations of rare earth and highly incompatible elements present in carbonatite magmas. In a recent study, Boron isotopic signatures of carbonatite complexes worldwide, ranging in age from ~2600 to ~65 million years old, indicate greater input of recycled (subducted), crustal material and plume activity with increasing geologic age of the Earth. More positive Boron isotopic values with increasing geologic time were attributed to the change of Earth’s geodynamics to a modern style of plate tectonics. In this study, the radiogenic (Sr, Nd, Pb) and B isotope systematics of carbonatites and alkaline rocks from west-central India are reported and discussed with reference to the plume-lithosphere interaction model previously proposed for the generation of Deccan-related alkaline centers in this region of the Indian sub-continent
DS201907-1532
2019
Simonetti, A.Chen, W., Liu, H-Y,m Jiang, S-Y., Simonetti, A., Xu, C., Zhang, W.The formation of the ore-bearing dolomite marble from the giant Bayan Obo REE-Nb-Fe deposit, Inner Mongolia: insights from micron-scale geochemical data.Mineralium Deposita, in press available, 16p.Asia, Mongoliadeposit - Bayan Obo

Abstract: The genesis of Earth’s largest rare earth element (REE) deposit, Bayan Obo (China), has been intensely debated, in particular whether the host dolomite marble is of sedimentary or igneous origin. The protracted (Mesoproterozoic to Paleozoic) and intricate (magmatic to metasomatic) geological processes complicate geochemical interpretations. In this study, we present a comprehensive petrographic and in situ, high-spatial resolution Sr-Pb isotopic and geochemical investigation of the host dolomite from the Bayan Obo marble. Based on petrographic evidence, the dolomite marble is divided into three facies including coarse-grained (CM), fine-grained (FM), and heterogeneous marble (HM). All carbonates are ferroan dolomite with high SrO and MnO contents (>?0.15 wt.%), consistent with an igneous origin. Trace element compositions of these dolomites are highly variable both among and within individual samples, with CM dolomite displaying the strongest LREE enrichment. In situ 206Pb/204Pb and 207Pb/204Pb ratios of the dolomite are generally consistent with mantle values. However, initial 208Pb/204Pb ratios define a large range from 35.45 to 39.75, which may result from the incorporation of radiogenic Pb released from decomposition of monazite and/or bastnäsite during Early Paleozoic metasomatism. Moreover, in situ Sr isotope compositions of dolomite indicate a large range (87Sr/86Sr?=?0.70292-0.71363). CM dolomite is characterized by a relatively consistent, unradiogenic Sr isotope composition (87Sr/86Sr?=?0.70295-0.70314), which is typical for Mesoproterozoic mantle. The variation of 87Sr/86Sr ratios together with radiogenic 206Pb/204Pb signatures for dolomite within FM and HM possibly represents recrystallization during Early Paleozoic metasomatism with the contribution of radiogenic Sr and Pb from surrounding host rocks. Therefore, our in situ geochemical data support a Mesoproterozoic igneous origin for the ore-bearing dolomite marble in the Bayan Obo deposit, which subsequently underwent intensive metasomatism during the Early Paleozoic.
DS201908-1775
2019
Simonetti, A.Cimen, O., Kuebler, C., Simonetti, S.S., Corcoran, L., Mitchell, R., Simonetti, A.Combined boron, radiogenic ( Nd, Pb, Sr) stable (C,O) isotopic and geochemical investigations of carbonatites from the Blue River region, British Columbia ( Canada): implications for mantle sources and recycling of crustal carbon.Chemical Geology, in press available, 59p. PdfCanada, British Columbiadeposit - Blue River

Abstract: This study reports the combined major, minor and trace element compositions, and stable (C, O), radiogenic (Nd, Pb, and Sr) isotopic compositions, and first d11B isotopic data for the Fir, Felix, Gum, and Howard Creek carbonatites from the Blue River Region, British Columbia (Canada). These sill-like occurrences were intruded into Late Proterozoic strata during rifting and extensional episodes during the Late Cambrian and Devonian -Mississippian, and subsequently deformed and metamorphosed to amphibolite grade in relation to a collisional-type tectonic environment. The carbonatites at Fir, Gum, and Felix contain both calcite and dolomite, whereas the carbonatite at Howard Creek contains only calcite. The dolomite compositions reported here are consistent with those experimentally determined by direct partial melting of metasomatized peridotitic mantle. The combined major and trace element compositions and d13CPDB (-5.37 to -4.85‰) and d18OSMOW (9.14 to 9.62‰) values for all the samples investigated are consistent with those for primary igneous carbonate and support their mantle origin. However, these signatures cannot be attributed to closed system melt differentiation from a single parental melt. The initial Nd, Pb, and Sr isotopic ratios are highly variable and suggest generation from multiple, small degree parental melts derived from a heterogeneous mantle source. The d11B values for carbonates from Felix, Gum, and Howard Creek vary between -8.67 and -6.36‰, and overlap the range for asthenospheric mantle (-7.1?±?0.9‰), whereas two samples from Fir yield heavier values of -3.98 and -2.47‰. The latter indicate the presence of recycled crustal carbon in their mantle source region, which is consistent with those for young (<300?Ma) carbonatites worldwide. The radiogenic and B isotope results for the Blue River carbonatites are compared to those from contrasting, anorogenic tectonic settings at Chipman Lake, Fen, and Jacupiranga, and indicate that similar upper mantle sources are being tapped for carbonatite melt generation. The pristine, mantle-like d11B values reported here for the Blue River carbonatites clearly demonstrate that this isotope system is robust and was not perturbed by post-solidification tectono-metamorphic events. This observation indicates that B isotope signatures are a valuable tool for deciphering the nature of the upper mantle sources for carbonates of igneous origin.
DS201909-2030
2019
Simonetti, A.Cimen, O., Kuebler, C., Simonetti, S.S., Corcoran, L., Mitchell, R., Simonetti, A.Combined boron, radiogenic (Nd, Pb, Sr), stable (C,O) isotopic and geochemical investigations of carbonatites from the Blue River region, British Columbia ( Canada): implications for mantle sources and recycling of crustal carbon.Chemical Geology, doi.org/10.1016/j.chemgeo.2019.07.015 59p.Canada, British Columbiacarbonatite - Blue River

Abstract: This study reports the combined major, minor and trace element compositions, and stable (C, O), radiogenic (Nd, Pb, and Sr) isotopic compositions, and first d11B isotopic data for the Fir, Felix, Gum, and Howard Creek carbonatites from the Blue River Region, British Columbia (Canada). These sill-like occurrences were intruded into Late Proterozoic strata during rifting and extensional episodes during the Late Cambrian and Devonian -Mississippian, and subsequently deformed and metamorphosed to amphibolite grade in relation to a collisional-type tectonic environment. The carbonatites at Fir, Gum, and Felix contain both calcite and dolomite, whereas the carbonatite at Howard Creek contains only calcite. The dolomite compositions reported here are consistent with those experimentally determined by direct partial melting of metasomatized peridotitic mantle. The combined major and trace element compositions and d13CPDB (-5.37 to -4.85‰) and d18OSMOW (9.14 to 9.62‰) values for all the samples investigated are consistent with those for primary igneous carbonate and support their mantle origin. However, these signatures cannot be attributed to closed system melt differentiation from a single parental melt. The initial Nd, Pb, and Sr isotopic ratios are highly variable and suggest generation from multiple, small degree parental melts derived from a heterogeneous mantle source. The d11B values for carbonates from Felix, Gum, and Howard Creek vary between -8.67 and -6.36‰, and overlap the range for asthenospheric mantle (-7.1?±?0.9‰), whereas two samples from Fir yield heavier values of -3.98 and -2.47‰. The latter indicate the presence of recycled crustal carbon in their mantle source region, which is consistent with those for young (<300?Ma) carbonatites worldwide. The radiogenic and B isotope results for the Blue River carbonatites are compared to those from contrasting, anorogenic tectonic settings at Chipman Lake, Fen, and Jacupiranga, and indicate that similar upper mantle sources are being tapped for carbonatite melt generation. The pristine, mantle-like d11B values reported here for the Blue River carbonatites clearly demonstrate that this isotope system is robust and was not perturbed by post-solidification tectono-metamorphic events. This observation indicates that B isotope signatures are a valuable tool for deciphering the nature of the upper mantle sources for carbonates of igneous origin.
DS202006-0960
2020
Simonetti, A.Ying, Y-C., Chen, W., Simonetti, A., Jiang, S-Y., Zhao, K-D.Significance of hydrothermal reworking for REE mineralization associated with carbonatite: constraints from in situ trace element and C-Sr isotope study of calcite and apatite from the Miaoya carbonatite complex (China).Geochimica et Cosmochimica Acta, in press available 45p. PdfChinadeposit - Miaoya

Abstract: A majority of carbonatite-related rare earth element (REE) deposits are found in cratonic margins and orogenic belts, and metasomatic/hydrothermal reworking is common in these deposits; however, the role of metasomatic processes involved in their formation remains unclear. Here, we present a comprehensive in situ chemical and isotopic (C-Sr) investigation of calcite and fluorapatite within the Miaoya carbonatite complex located in the South Qinling orogenic belt, with the aim to better define the role of late-stage metasomatic processes. Carbonatite at Miaoya commonly occurs as stocks and dykes intruded into associated syenite, and can be subdivided into equigranular (Type I) and inequigranular (Type II) calcite carbonatites. Calcite in Type I carbonatite is characterized by the highest Sr (up to ~22,000?ppm) and REE (195-542?ppm) concentrations with slight LREE-enriched chondrite normalized patterns [(La/Yb)N?=?2.1-5.2]. In situ C and Sr isotopic compositions of calcite in Type I carbonatite define a limited range (87Sr/86Sr?=?0.70344-0.70365; d13C?=?-7.1 to -4.2 ‰) that are consistent with a mantle origin. Calcite in Type II carbonatite has lower Sr (1708-16322?ppm) and REEs (67-311?ppm) and displays variable LREE-depleted chondrite normalized REE patterns [(La/Yb)N?=?0.2-3.3; (La/Sm)N?=?0.2-2.0]. In situ 87Sr/86Sr and d13C isotopic compositions of Type II calcite are highly variable and range from 0.70350 to 0.70524 and -7.0 to -2.2 ‰, respectively. Fluorapatite in Type I and Type II carbonatites is characterized by similar trace-element and isotopic compositions. Both types of fluorapatite display variable trace element concentrations, especially LREE contents, whereas they exhibit relatively consistent near-chondritic Y/Ho ratios. Fluorapatite is characterized by consistent Sr isotopic compositions with a corresponding average 87Sr/86Sr ratio of 0.70359, which suggests that fluorapatite remained relatively closed in relation to contamination. The combined geochemical and isotopic data for calcite and fluorapatite from the Miaoya complex suggest that carbonatite-exsolved fluids together with possible syenite assimilation during the Mesozoic metasomatism overprinted the original trace-element and isotopic signatures acquired in the early Paleozoic magmatism. Hydrothermal reworking resulted in dissolution-reprecipitation of calcite and fluorapatite, which served as the dominant source of REE mineralization during the much younger metasomatic activity. The results from this study also suggest that carbonatites located in orogenic belts and cratonic edges possess a great potential for forming economic REE deposits, especially those that have undergone late-stage metasomatic reworking.
DS202007-1133
2020
Simonetti, A.Cimen, O., Corcoran, L., Kuebler, C., Simonetti, S.S., Simonetti, A.Geochemical, stable ( O, C, and B) and radiogenic ( Sr, Nd, Pb) isotopic data from the Eskisehir-Kizulxaoren ( NW-Anatolia) and the Malatya-Kuluncak ( E- central Anatolia) F-REE-Th deposits, Turkey: implications for nature of carbonate-hosted mineralizatiTurkish Journal of Earth Sciences, Vol. 29, doe:10.3906/yer-2001-7 18p. PdfEurope, TurkeyREE
DS201709-2054
2017
Simonetti, S.Smart, K., Tappe, S., Simonetti, A., Simonetti, S., Woodland, A., Harris, C.The redox state of mantle eclogites.Goldschmidt Conference, abstract 1p.Mantleeclogites

Abstract: Mantle-derived eclogite xenoliths are key for studying the evolution of the cratonic lithosphere, because geochemical evidence suggests that they typically represent fragments of Archean and Proterozoic oceanic lithosphere [1]. Recently, it has been suggested that eclogite xenoliths can serve as redox sensors of the Precambrian upper mantle using V/Sc as a redox proxy [2]. However, metasomatism can change the original oxidation state of the cratonic mantle [3], thereby limiting its use for monitoring mantle redox evolution. Circa 1.8–2.2 Ga eclogite xenoliths erupted with Jurassic kimberlites of the northern Slave craton have geochemical features that indicate oceanic crust protoliths [4, 5]. Such Paleoproterozoic ages are common for Slave craton mantle eclogites [6], linking eclogite formation with 1.9 Ga subduction-collision events at the western craton margin. The eclogites studied here have highly variable Fe3+/SFe (0.019 – 0.076 ±0.01), with logfO2 (?FMQ-4 to +2 ±0.5) that are both relatively oxidized and reduced compared to Slave mantle peridotite xenoliths [3]. Also, eclogite fO2 positively correlates with some indicies of metasomatism, such as elevated TiO2 in garnet. In addition to considering the time gap between eclogite formation and kimberlite eruption, the highly variable fO2–depth systematics of the eclogites studied here illustrate the drawbacks of using averaged eclogite fO2 to define the redox evolution of the upper mantle. Despite this, the ca. 2 Ga northern Slave craton eclogites have an average depth-corrected logfO2 of ?FMQ-0.5±1.3 (1s) that overlaps with modern MORB, and complies with the upper mantle redox evolution trend predicted using V/Sc ratios of mantlederived melts [2]. However, given the debate around the secuarity of mantle redox [7], further research into the suitability of mantle eclogites as redox sensors is warranted.
DS200812-0059
2008
Simonetti, S.S.Aulbach, S., Creaser, R.A.,Heaman, L.M., Simonetti, S.S., Griffin, W.L., Stachel, T.Sulfides, diamonds and eclogites: their link to peridotites and Slave Craton hydrothermal evolution.Goldschmidt Conference 2008, Abstract p.A36.Canada, Northwest TerritoriesDeposit - A 154, geochronology
DS200912-0018
2009
Simonetti, S.S.Aulbach, S., Creaser, R.A., Pearson, N.J., Simonetti, S.S., Heaman, L.M., Griffin, W.L., Stachel, T.Sulfide and whole rock Re-Os systematics of eclogite and pyroxenite xenoliths from the Slave Craton, Canada.Earth and Planetary Science Letters, in press available,Canada, Northwest TerritoriesDeposit - Diavik
DS201012-0180
2010
Simonetti, S.S.Eccles, D.R., Simonetti, S.S., Cox, R.Garnet pyroxenite and granulite xenoliths from northeastern Alberta: evidence of not vertical similarity 1.5 Ga lower crust and mantle w. LaurentiaPrecambrian Research, Vol. 177, 3-4, pp. 339-354.Canada, AlbertaXenoliths
DS201707-1369
2017
Simonetti, S.S.Smart, K.A., Tappe, S., Simonetti, A., Simonetti, S.S., Woodland, A.B., Harris, C.Tectonic significance and redox state of Paleoproterozoic eclogite and pyroxenite components in the Slave cratonic mantle lithosphere, Voyager kimberlite, Arctic Canada.Chemical Geology, Vol. 455, pp. 98-119.Canadadeposit - Voyager

Abstract: Mantle-derived eclogite and pyroxenite xenoliths from the Jurassic Voyageur kimberlite on the northern Slave craton in Arctic Canada were studied for garnet and clinopyroxene major and trace element compositions, clinopyroxene Pb and garnet O isotopic compositions, and garnet Fe3 +/SFe contents. The Voyageur xenoliths record a wide range of pressures, but are cooler compared to mantle xenoliths derived from the nearby, coeval Jericho kimberlite. The CaO, TiO2 and Zr contents of Voyageur eclogites increase with depth, which is also observed in northern Slave peridotite xenoliths, demonstrating ‘bottom-up’ metasomatic processes within cratonic mantle lithosphere. The Voyageur eclogites have positive Eu anomalies, flat HREEN patterns, and major element compositions that are consistent with ultimate origins from basaltic and gabbroic protoliths within oceanic lithosphere. Clinopyroxene Pb isotope ratios intercept the Stacey-Kramers two-stage terrestrial Pb evolution curve at ca. 2.1 Ga, and form an array towards the host kimberlite, indicating isotopic mixing. The 2.1 Ga eclogite formation age broadly overlaps with known Paleoproterozoic subduction and collision events that occurred along the western margin of the Slave craton. Unlike the eclogites, the Voyageur pyroxenites contain garnet with distinctive fractionated HREEN, sinusoidal REE patterns of calculated bulk rocks, and clinopyroxene with 206Pb/204Pb ratios that intercept the Stacey-Kramers curve at 1.8 Ga. This suggests a distinct origin as Paleoproterozoic high-pressure mantle cumulates. However, the pyroxenite Pb isotope ratios fall within the eclogite array and could also be explained by protoliths formation at ca. 2.1 Ga followed by minor isotopic mixing during mantle metasomatism. Thus, an alternative scenario involves pyroxenite formation within the mantle section of Paleoproterozoic oceanic lithosphere followed by variable metasomatism after incorporation into cratonic mantle lithosphere. This model allows for a linked petrogenesis of the Voyageur eclogites (crust) and pyroxenites (mantle) as part of the same subducting oceanic slab. Oxygen fugacity determinations for one pyroxenite and ten eclogite xenoliths show a range of 3 log units, from - 4.6 to - 1.6 ?FMQ, similar to the range observed for nearby Jericho and Muskox eclogites (?FMQ - 4.2 to - 1.5). Importantly, the northern Slave eclogite and pyroxenite mantle components are highly heterogeneous in terms of redox state provided that they range from reduced to oxidized relative to Slave peridotite xenoliths. Moreover, the Voyageur eclogites do not exhibit any trend between oxidation state and equilibration depth, which contrasts with the downward decrease in fO2 shown by Slave and worldwide cratonic peridotite xenoliths. Our investigation of mantle eclogite and pyroxenite fO2 reinforces the important influence of recycled mafic components in upper mantle processes, because their high and variable redox buffering capacity strongly controls volatile speciation and melting relations under upper mantle conditions.
DS201709-1956
2017
Simonetti, S.S.Aulbach, S., Jacob, D.E., Cartigny, P., Stern, R.A., Simonetti, S.S., Worner, G., Viljoen, K.S.Eclogite xenoliths from Orapa: ocean crust recycling, mantle metasomatism and carbon cycling at the western Zimbabwe craton margin.Geochimica et Cosmochimica Acta, Vol. 213, pp. 574-592.Africa, Botswanadeposit - Orapa

Abstract: Major- and trace-element compositions of garnet and clinopyroxene, as well as 87Sr/86Sr in clinopyroxene and d18O in garnet in eclogite and pyroxenite xenoliths from Orapa, at the western margin of the Zimbabwe craton (central Botswana), were investigated in order to trace their origin and evolution in the mantle lithosphere. Two groups of eclogites are distinguished with respect to 87Sr/86Sr: One with moderate ratios (0.7026-0.7046) and another with 87Sr/86Sr >0.7048 to 0.7091. In the former group, heavy d18O attests to low-temperature alteration on the ocean floor, while 87Sr/86Sr correlates with indices of low-pressure igneous processes (Eu/Eu*, Mg#, Sr/Y). This suggests relatively undisturbed long-term ingrowth of 87Sr at near-igneous Rb/Sr after metamorphism, despite the exposed craton margin setting. The high-87Sr/86Sr group has mainly mantle-like d18O and is suggested to have interacted with a small-volume melt derived from an aged phlogopite-rich metasome. The overlap of diamondiferous and graphite-bearing eclogites and pyroxenites over a pressure interval of ~3.2 to 4.9 GPa is interpreted as reflecting a mantle parcel beneath Orapa that has moved out of the diamond stability field, due to a change in geotherm and/or decompression. Diamondiferous eclogites record lower median 87Sr/86Sr (0.7039) than graphite-bearing samples (0.7064) and carbon-free samples (0.7051), suggesting that interaction with the - possibly oxidising - metasome-derived melt caused carbon removal in some eclogites, while catalysing the conversion of diamond to graphite in others. This highlights the role of small-volume melts in modulating the lithospheric carbon cycle. Compared to diamondiferous eclogites, eclogitic inclusions in diamonds are restricted to high FeO and low SiO2, CaO and Na2O contents, they record higher equilibrium temperatures and garnets have mostly mantle-like O isotopic composition. We suggest that this signature was imparted by a sublithospheric melt with contributions from a clinopyroxene-rich source, possibly related to the ca. 2.0 Ga Bushveld event.
DS201710-2212
2017
Simonetti, S.S.Aulbach, S., Jacob, D.E., Cartigny, P., Stern, R.A., Simonetti, S.S., Womer, G., Viljoen, K.S.Eclogite xenoliths from Orapa: Ocean crust recycling, mantle metasomatism and carbon cycling at the western Zimbabwe craton margin.Geochimica et Cosmochinica Acta, Vol. 213, pp. 574-592.Africa, Botswanadeposit - Orapa

Abstract: Major- and trace-element compositions of garnet and clinopyroxene, as well as 87Sr/86Sr in clinopyroxene and d18O in garnet in eclogite and pyroxenite xenoliths from Orapa, at the western margin of the Zimbabwe craton (central Botswana), were investigated in order to trace their origin and evolution in the mantle lithosphere. Two groups of eclogites are distinguished with respect to 87Sr/86Sr: One with moderate ratios (0.7026-0.7046) and another with 87Sr/86Sr >0.7048 to 0.7091. In the former group, heavy d18O attests to low-temperature alteration on the ocean floor, while 87Sr/86Sr correlates with indices of low-pressure igneous processes (Eu/Eu*, Mg#, Sr/Y). This suggests relatively undisturbed long-term ingrowth of 87Sr at near-igneous Rb/Sr after metamorphism, despite the exposed craton margin setting. The high-87Sr/86Sr group has mainly mantle-like d18O and is suggested to have interacted with a small-volume melt derived from an aged phlogopite-rich metasome. The overlap of diamondiferous and graphite-bearing eclogites and pyroxenites over a pressure interval of ~3.2 to 4.9 GPa is interpreted as reflecting a mantle parcel beneath Orapa that has moved out of the diamond stability field, due to a change in geotherm and/or decompression. Diamondiferous eclogites record lower median 87Sr/86Sr (0.7039) than graphite-bearing samples (0.7064) and carbon-free samples (0.7051), suggesting that interaction with the - possibly oxidising - metasome-derived melt caused carbon removal in some eclogites, while catalysing the conversion of diamond to graphite in others. This highlights the role of small-volume melts in modulating the lithospheric carbon cycle. Compared to diamondiferous eclogites, eclogitic inclusions in diamonds are restricted to high FeO and low SiO2, CaO and Na2O contents, they record higher equilibrium temperatures and garnets have mostly mantle-like O isotopic composition. We suggest that this signature was imparted by a sublithospheric melt with contributions from a clinopyroxene-rich source, possibly related to the ca. 2.0 Ga Bushveld event.
DS201809-1991
2017
Simonetti, S.S.Aulbach, S., Jacob, D.E., Cartigny, P., Stern, R.A., Simonetti, S.S., Worner, G., Viljoen, K.S.Eclogite xenoliths from Orapa: Ocean crust recycling, mantle metasomatism and carbon cycling at the western Zimbabwe craton margin.Geochimica et Cosmochimica Acta, Vol. 213, 1, pp. 574-592.Africa, Botswanadeposit - Orapa

Abstract: Major- and trace-element compositions of garnet and clinopyroxene, as well as 87Sr/86Sr in clinopyroxene and d18O in garnet in eclogite and pyroxenite xenoliths from Orapa, at the western margin of the Zimbabwe craton (central Botswana), were investigated in order to trace their origin and evolution in the mantle lithosphere. Two groups of eclogites are distinguished with respect to 87Sr/86Sr: One with moderate ratios (0.7026-0.7046) and another with 87Sr/86Sr >0.7048 to 0.7091. In the former group, heavy d18O attests to low-temperature alteration on the ocean floor, while 87Sr/86Sr correlates with indices of low-pressure igneous processes (Eu/Eu*, Mg#, Sr/Y). This suggests relatively undisturbed long-term ingrowth of 87Sr at near-igneous Rb/Sr after metamorphism, despite the exposed craton margin setting. The high-87Sr/86Sr group has mainly mantle-like d18O and is suggested to have interacted with a small-volume melt derived from an aged phlogopite-rich metasome. The overlap of diamondiferous and graphite-bearing eclogites and pyroxenites over a pressure interval of ~3.2 to 4.9 GPa is interpreted as reflecting a mantle parcel beneath Orapa that has moved out of the diamond stability field, due to a change in geotherm and/or decompression. Diamondiferous eclogites record lower median 87Sr/86Sr (0.7039) than graphite-bearing samples (0.7064) and carbon-free samples (0.7051), suggesting that interaction with the - possibly oxidising - metasome-derived melt caused carbon removal in some eclogites, while catalysing the conversion of diamond to graphite in others. This highlights the role of small-volume melts in modulating the lithospheric carbon cycle. Compared to diamondiferous eclogites, eclogitic inclusions in diamonds are restricted to high FeO and low SiO2, CaO and Na2O contents, they record higher equilibrium temperatures and garnets have mostly mantle-like O isotopic composition. We suggest that this signature was imparted by a sublithospheric melt with contributions from a clinopyroxene-rich source, possibly related to the ca. 2.0 Ga Bushveld event.
DS201812-2790
2018
Simonetti, S.S.Cimen, O., Kuebler, C., Monaco, B., Simonetti, S.S., Corcoran, L., Chen, W., Simonatti, A.Boron, carbon, oxygen and radiogenic isotope investigation of carbonatite from the Miaoya complex, central China: evidences for late stage REE hydrothermal event and mantle source heterogeneity.Lithos, Vol. 322, pp. 225-237.Chinadeposit - Miaoya

Abstract: The Miaoya carbonatite complex (MCC) is located within the southern edge of the Qinling orogenic belt in central China, and is associated with significant rare earth element (REE) and Nb mineralization. The MCC consists of syenite and carbonatite that were emplaced within Neo- to Mesoproterozoic-aged supracrustal units. The carbonatite intruded the associated syenite as stocks and dikes, and is mainly composed of medium- to fine-grained calcite and abundant REE-bearing minerals. Carbonatite melt generation and emplacement within the MCC occurred during the Silurian (at ~440?Ma), and was subsequently impacted by a late-stage hydrothermal event (~232?Ma) involving REE-rich fluids/melt. This study reports trace element and stable (B, C, and O) and radiogenic (Nd, Pb, and Sr) isotope data for the MCC carbonatite, and these have been subdivided into three groups that represent different REE contents, interpreted as varying degrees of hydrothermal interaction. Overall, the group of carbonatites with the lowest enrichment in LREEs (i.e., least affected by hydrothermal event) is characterized by d11B values that vary between -7 (typical asthenospheric mantle) and?+?4‰; d11B values and B abundances (~0.2 to ~1?ppm) do not correlate with LREE contents. The Sm-Nd and Pb-Pb isotope systems have both been perturbed by the late-stage, REE-rich hydrothermal activity and corroborate open-system behavior. Contrarily, initial 87Sr/86Sr ratios (vary between ~0.70355 and 0.70385) do not correlate significantly with both LREEs and Sr abundances, nor with initial 143Nd/144Nd ratios. The late-stage hydrothermal event overprinted the Nd and Pb isotope compositions for most of the carbonatite samples examined here, whereas a majority of the samples preserve their variable B and Sr isotope values inherited from their mantle source. The B and Sr isotope data for carbonatites exhibiting the least LREE enrichment correlate positively and suggest carbonatite melt generation from a heterogenous upper mantle source that records the input of recycled crustal material. This finding is consistent with those previously reported for young (<300?Ma old) carbonatites worldwide.
DS201908-1775
2019
Simonetti, S.S.Cimen, O., Kuebler, C., Simonetti, S.S., Corcoran, L., Mitchell, R., Simonetti, A.Combined boron, radiogenic ( Nd, Pb, Sr) stable (C,O) isotopic and geochemical investigations of carbonatites from the Blue River region, British Columbia ( Canada): implications for mantle sources and recycling of crustal carbon.Chemical Geology, in press available, 59p. PdfCanada, British Columbiadeposit - Blue River

Abstract: This study reports the combined major, minor and trace element compositions, and stable (C, O), radiogenic (Nd, Pb, and Sr) isotopic compositions, and first d11B isotopic data for the Fir, Felix, Gum, and Howard Creek carbonatites from the Blue River Region, British Columbia (Canada). These sill-like occurrences were intruded into Late Proterozoic strata during rifting and extensional episodes during the Late Cambrian and Devonian -Mississippian, and subsequently deformed and metamorphosed to amphibolite grade in relation to a collisional-type tectonic environment. The carbonatites at Fir, Gum, and Felix contain both calcite and dolomite, whereas the carbonatite at Howard Creek contains only calcite. The dolomite compositions reported here are consistent with those experimentally determined by direct partial melting of metasomatized peridotitic mantle. The combined major and trace element compositions and d13CPDB (-5.37 to -4.85‰) and d18OSMOW (9.14 to 9.62‰) values for all the samples investigated are consistent with those for primary igneous carbonate and support their mantle origin. However, these signatures cannot be attributed to closed system melt differentiation from a single parental melt. The initial Nd, Pb, and Sr isotopic ratios are highly variable and suggest generation from multiple, small degree parental melts derived from a heterogeneous mantle source. The d11B values for carbonates from Felix, Gum, and Howard Creek vary between -8.67 and -6.36‰, and overlap the range for asthenospheric mantle (-7.1?±?0.9‰), whereas two samples from Fir yield heavier values of -3.98 and -2.47‰. The latter indicate the presence of recycled crustal carbon in their mantle source region, which is consistent with those for young (<300?Ma) carbonatites worldwide. The radiogenic and B isotope results for the Blue River carbonatites are compared to those from contrasting, anorogenic tectonic settings at Chipman Lake, Fen, and Jacupiranga, and indicate that similar upper mantle sources are being tapped for carbonatite melt generation. The pristine, mantle-like d11B values reported here for the Blue River carbonatites clearly demonstrate that this isotope system is robust and was not perturbed by post-solidification tectono-metamorphic events. This observation indicates that B isotope signatures are a valuable tool for deciphering the nature of the upper mantle sources for carbonates of igneous origin.
DS201909-2030
2019
Simonetti, S.S.Cimen, O., Kuebler, C., Simonetti, S.S., Corcoran, L., Mitchell, R., Simonetti, A.Combined boron, radiogenic (Nd, Pb, Sr), stable (C,O) isotopic and geochemical investigations of carbonatites from the Blue River region, British Columbia ( Canada): implications for mantle sources and recycling of crustal carbon.Chemical Geology, doi.org/10.1016/j.chemgeo.2019.07.015 59p.Canada, British Columbiacarbonatite - Blue River

Abstract: This study reports the combined major, minor and trace element compositions, and stable (C, O), radiogenic (Nd, Pb, and Sr) isotopic compositions, and first d11B isotopic data for the Fir, Felix, Gum, and Howard Creek carbonatites from the Blue River Region, British Columbia (Canada). These sill-like occurrences were intruded into Late Proterozoic strata during rifting and extensional episodes during the Late Cambrian and Devonian -Mississippian, and subsequently deformed and metamorphosed to amphibolite grade in relation to a collisional-type tectonic environment. The carbonatites at Fir, Gum, and Felix contain both calcite and dolomite, whereas the carbonatite at Howard Creek contains only calcite. The dolomite compositions reported here are consistent with those experimentally determined by direct partial melting of metasomatized peridotitic mantle. The combined major and trace element compositions and d13CPDB (-5.37 to -4.85‰) and d18OSMOW (9.14 to 9.62‰) values for all the samples investigated are consistent with those for primary igneous carbonate and support their mantle origin. However, these signatures cannot be attributed to closed system melt differentiation from a single parental melt. The initial Nd, Pb, and Sr isotopic ratios are highly variable and suggest generation from multiple, small degree parental melts derived from a heterogeneous mantle source. The d11B values for carbonates from Felix, Gum, and Howard Creek vary between -8.67 and -6.36‰, and overlap the range for asthenospheric mantle (-7.1?±?0.9‰), whereas two samples from Fir yield heavier values of -3.98 and -2.47‰. The latter indicate the presence of recycled crustal carbon in their mantle source region, which is consistent with those for young (<300?Ma) carbonatites worldwide. The radiogenic and B isotope results for the Blue River carbonatites are compared to those from contrasting, anorogenic tectonic settings at Chipman Lake, Fen, and Jacupiranga, and indicate that similar upper mantle sources are being tapped for carbonatite melt generation. The pristine, mantle-like d11B values reported here for the Blue River carbonatites clearly demonstrate that this isotope system is robust and was not perturbed by post-solidification tectono-metamorphic events. This observation indicates that B isotope signatures are a valuable tool for deciphering the nature of the upper mantle sources for carbonates of igneous origin.
DS202007-1133
2020
Simonetti, S.S.Cimen, O., Corcoran, L., Kuebler, C., Simonetti, S.S., Simonetti, A.Geochemical, stable ( O, C, and B) and radiogenic ( Sr, Nd, Pb) isotopic data from the Eskisehir-Kizulxaoren ( NW-Anatolia) and the Malatya-Kuluncak ( E- central Anatolia) F-REE-Th deposits, Turkey: implications for nature of carbonate-hosted mineralizatiTurkish Journal of Earth Sciences, Vol. 29, doe:10.3906/yer-2001-7 18p. PdfEurope, TurkeyREE
DS200812-0493
2008
Simonetti, T.Hunt, L., Stachel, T., Simonetti, T., Armstrong, J., McCandless, T.E.Microxenoliths from the Renard kimberlites, Quebec.Northwest Territories Geoscience Office, p. 35-36. abstractCanada, QuebecBrief overview - Stornoway
DS2000-0886
2000
SimonovShatskii, V.S., Simonov, Jagoutz, Kozmenko, KurenkovNew dat a on the age of eclogites from the Polar UralsDoklady Academy of Sciences, Vol. 371a, No. 3, Mar-Apr. pp. 534-8.Russia, UralsEclogites, Geochronology
DS1998-0289
1998
Simonov, O.Czamanske, G.K., Gurevitch, A.B., Simonov, O.Demise of the Siberian plume: paleogeographic and paleotectonic reconstruction from the Prevolcanic...International Geology Review, Vol. 40, No. 2, Feb. pp. 95-115Russia, SiberiaVolcanics, Tectonics - plumes
DS1989-1060
1989
Simonov, V.A.Morozov, D.L., Simonov, V.A.Dike complex of the Pekulnyi ridge (Chukotka).(Russian)Sov. Geol., (Russian), No. 10, pp. 54-61RussiaPicrite, Dike
DS1991-1587
1991
Simonov, V.A.Simonov, V.A., Kuznetsov, P.P.Boninites in Vendian-Cambrian ophiolites of Gorny Altai.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 316, No. 2, pp. 448-452RussiaBoninites, Related rocks
DS1993-0359
1993
Simonov, V.A.Dobretsov, N.L., Ashchepkov, I.V., Simonov, V.A., Zhmodik, S.M.Interaction of the upper-mantle rocks with deep seated fluids and melts In the Baikal rift zoneSoviet Geology and Geophysics, Vol. 33, No. 5, pp. 1-14Russia, Commonwealth of Independent States (CIS), BaikalTectonics, Geochemistry, Thermobarometry
DS1993-0360
1993
Simonov, V.A.Dobretsov, N.L., Buslov, M.M., Simonov, V.A.Associated ophiolites, glaucophane schists and eclogites of the GornyyAltai.Doklady Academy of Sciences USSR, Vol. 318, pp. 123-127.RussiaEclogites
DS1996-1315
1996
Simonov, V.A.Simonov, V.A.Boninite containing paleospreading complexes in the northern Sayanophiolite beltDoklady Academy of Sciences, Vol. 343A, No. 6, June, pp. 87-92Russia, SayanBoninite, ophiolite
DS1998-1353
1998
Simonov, V.A.Simonov, V.A., Kurenkov, S.A., Stupakov, S.I.Boninite series in the paleospreading complexes of the Polar UralsDoklady Academy of Sciences, Vol. 361, No. 5, pp. 681-4.Russia, UralsBoninites
DS200512-0992
2005
Simonov, V.A.Simonov, V.A., Kovyazin, S.V., Peive, A.A., Kolmogorov, Y.P.Geochemical characteristics of magmatic systems in the region of the Sierra Leone Fracture Zone: central Atlantic: evidence from melt inclusions.Geochemistry International, Vol. 43, 7, pp. 682-693.Africa, Sierra LeoneMagmatism, chemistry
DS200512-0993
2005
Simonov, V.A.Simonov, V.A., Kovyazin, S.V., Peive, A.A., Kolmogorov, Yu.P.Geochemical characteristics of magmatic systems in the region of the Sierra Leone Fracture Zone, Central Atlantic: evidence from melt inclusions.Geochemistry International, Vol. 7, 5, pp. 682-Africa, Sierra LeoneMagmatism
DS200612-1309
2006
Simonov, V.A.Simonov, V.A., Sklyarov, E.V., Kovyazin, S.V., Perelyaev, V.I.Physicochemical parameters of oldest boninite melts.Doklady Earth Sciences, Vol. 408, 4, pp. 667-670.RussiaBoninites
DS201012-0714
2010
Simonov, V.A.Simonov, V.A., Prikhodko, V.S., Kovyazin, S.V., Tarnavsky, A.V.Crystallization conditions of dunites in the Konder platiniferous alkaline ultramafic massif of the southeastern Aldan Shield.Russian Journal of Pacific Geology, Vol. 4, 5, pp. 429-440.Russia, Aldan ShieldAlkalic
DS201501-0032
2014
Simonov, V.A.Simonov, V.A., Prikhodko, V.S., Kovyazin, S.V., Kotlyarov, A.V.Petrogenesis of meymechites of Sikhote Alin inferred from melt inclusions.Russian Journal of Pacific Geology, Vol. 8, 6, pp. 423-442.RussiaMeymechites
DS201804-0737
2017
Simonov, V.A.Simonov, V.A., Prikhodko, V.S., Vasiliev, Yu.R., Kotlyarov, A.V.Physicochemical conditions of the crystallization of rocks from ultrabasic massifs of the Siberian platform. Konder, Inagli, Chad) Cr-spinelsRussian Journal of Pacific Geology, Vol. 11, 6, pp. 447-468.Russiapicrites

Abstract: A great volume of original information on the formation of the ultrabasic rocks of the Siberian Platform has been accumulated owing to the study of melt inclusions in Cr-spinels. The inclusions show the general tendencies in the behavior of the magmatic systems during the formation of the ultrabasic massifs of the Siberian Platform, tracing the main evolution trend of decreasing Mg number with SiO2 increase in the melts with subsequent transition from picrites through picrobasalts to basalts. The compositions of the melt inclusions indicate that the crystallization conditions of the rocks of the concentrically zoned massifs (Konder, Inagli, Chad) sharply differ from those of the Guli massif. Numerical modeling using the PETROLOG and PLUTON softwares and data on the composition of inclusions in Cr-spinels yielded maximum crystallization temperatures of the olivines from the dunites of the Konder (1545-1430°C), Inagli (1530-1430°C), Chad (1460-1420°C), and Guli (1520-1420°C) massifs, and those of Cr-spinels from the Konder (1420-1380°C), Inagli (up to 1430°C), Chad (1430-1330°C), and Guli (1410-1370°C) massifs. Modeling of the Guli massif with the PLUTON software using the compositions of the melt inclusions revealed the possible formation of the alkaline rocks at the final reverse stage of the evolution of the picritic magmas (with decrease of SiO2 and alkali accumulation) after termination of olivine crystallization with temperature decrease from 1240-1230°C to 1200-1090°C. Modeling with the PLUTON software showed that the dunites of the Guli massif coexisted with Fe-rich (with moderate TiO2 contents) melts, the crystallization of which led (beginning from 1210°C) to the formation of pyroxenes between cumulate olivine. Further temperature decrease (from 1125°C) with decreasing FeO and TiO2 contents provided the formation of clinopyroxenes of pyroxenites. For the Konder massif, modeling with the PLUTON software indicates the possible formation of kosvites from picrobasaltic magmas beginning from 1350°C and the formation of clinopyroxenites and olivine-diopside rocks from olivine basaltic melts from 1250°C.
DS201909-2089
2019
Simonov, V.A.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.
DS201706-1091
2017
Simonova, D.A.Litvin, Y.A., Spivak, A.V., Simonova, D.A., Dubrovinsky, L.S.The stishovite paradox in the evolution of lower mantle magmas and diamond forming melts ( experiment at 24 and 26 Gpa)Doklady Earth Sciences, Vol. 473, pp. 444-448.Technologydiamond - ultradeep

Abstract: Experimental studies of phase relations in the oxide-silicate system MgO-FeO-SiO2 at 24 GPa show that the peritectic reaction of bridgmanite controls the formation of stishovite as a primary in situ mineral of the lower mantle and as an effect of the stishovite paradox. The stishovite paradox is registered in the diamond-forming system MgO-FeO-SiO2-(Mg-Fe-Ca-Na carbonate)-carbon in experiments at 26 GPa as well. The physicochemical mechanisms of the ultrabasic-basic evolution of deep magmas and diamondforming media, as well as their role in the origin of the lower mantle minerals and genesis of ultradeep diamonds, are studied.
DS201910-2302
2019
Simonova, D.A.Spivak, A.V., Litvin, Yu.A., Zakharchenko, E.S., Simonova, D.A., Dubrovinsky, L.S.Evolution of diamond forming systems of the mantle transition zone: ringwoodite peritectic reaction ( Mg, Fe)2SiO4 ( experiment at 20GPa)Geochemistry International, Vol. 57, 9, pp. 1000-1007.Mantlediamond genesis

Abstract: The peritectic reaction of ringwoodite (Mg,Fe)2SiO4 and silicate-carbonate melt with formation of magnesiowustite (Fe,Mg)O, stishovite SiO2, and Mg, Na, Ca, K-carbonates is revealed by experimental study at 20 GPa of phase relations in the multicomponent diamond-forming MgO-FeO-SiO2-Na2CO3-CaCO3-K2CO3 system of the Earth mantle transition zone. An interaction of CaCO3 and SiO2 with a formation of Ca-perovskite CaSiO3 is also detected. It is shown that the peritectic reaction of ringwoodite and melt with the formation of stishovite controls physicochemically the fractional ultrabasic-basic evolution of both magmatic and diamond-forming systems of deep horizons of the transition zone up to its boundary with the Earth lower mantle.
DS1999-0671
1999
Simons, F.J.Simons, F.J., Zielhuis, A., Van der Hilst, R.D.The deep structure of the Australian continent from surface wavetomography.Lithos, Vol. 48, No. 1-4, Sept. pp. 17-44.AustraliaGeophysics - seismics, Tectonics
DS2000-0899
2000
Simons, F.J.Simons, F.J., Zuber, M.T., Korenaga, J.Isostatic response of the Australian lithosphere: estimation of effective elastic thickness anisotropyJournal of Geophysical Research, Vol. 105, No.8, Aug. 10, pp.19163-84.AustraliaGeophysics - Multitaper spectral analysis
DS2002-1491
2002
Simons, F.J.Simons, F.J., Van der Hilst, R.D.Age dependent seismic thickness and mechanical strength of the Australian lithosphereGeophysical Research Letters, Vol. 29, 11, pp. 24- DOI 10.1029/2001GLO14962AustraliaGeophysics - seismics, Tectonics
DS2003-1283
2003
Simons, F.J.Simons, F.J., Van der Hilst, R.D.Seismic and mechanical anisotropy and the past and present deformation of theEarth and Planetary Science Letters, Vol. 211, 3-4, June 30, pp. 271-86.AustraliaGeophysics - seismics, Tectonics, mantle deformation
DS2003-1284
2003
Simons, F.J.Simons, F.J., Van der Hilst, R.D.Seismic and mechanical anisotropy and the past and present deformation of theEarth and Planetary Science Letters, Vol. 211, 3-4, pp. 271-86.AustraliaTectonics
DS200412-1835
2003
Simons, F.J.Simons, F.J., Van der Hilst, R.D.Seismic and mechanical anisotropy and the past and present deformation of the Australian lithosphere.Earth and Planetary Science Letters, Vol. 211, 3-4, pp. 271-86.AustraliaGeophysics - seismics, tectonics
DS200512-0348
2005
Simons, F.J.Goes, S., Simons, F.J., Yoshizawa, K.Seismic constraints on temperature of the Australian upper mantle.Earth and Planetary Science Letters, Vol. 236, 1-2, pp. 227-237.AustraliaGeophysics - seismics
DS201505-0240
2015
Simons, F.J.Kalnins, L.M., Simons, F.J., Kirby, J.F., Wang, D.V., Olhede, S.C.On the robustness of estimates of mechanical anisotropy in the continental lithosphere: a North American case study and global reanalysis.Earth and Planetary Science Letters, Vol. 419, pp. 43-51.United States, CanadaTectonics
DS202012-2244
2020
Simons, F.J.Reuber, G.S., Simons, F.J.Multi-physics adjoint modeling of Earth structure: combining gravimetric, seismic, and geodynamic inversions.GEM: International Journal on Geomathematics, open access 38p. PdfMantlegeophysics - magnetics

Abstract: We discuss the resolving power of three geophysical imaging and inversion techniques, and their combination, for the reconstruction of material parameters in the Earth’s subsurface. The governing equations are those of Newton and Poisson for gravitational problems, the acoustic wave equation under Hookean elasticity for seismology, and the geodynamics equations of Stokes for incompressible steady-state flow in the mantle. The observables are the gravitational potential, the seismic displacement, and the surface velocity, all measured at the surface. The inversion parameters of interest are the mass density, the acoustic wave speed, and the viscosity. These systems of partial differential equations and their adjoints were implemented in a single Python code using the finite-element library FeNICS. To investigate the shape of the cost functions, we present a grid search in the parameter space for three end-member geological settings: a falling block, a subduction zone, and a mantle plume. The performance of a gradient-based inversion for each single observable separately, and in combination, is presented. We furthermore investigate the performance of a shape-optimizing inverse method, when the material is known, and an inversion that inverts for the material parameters of an anomaly with known shape.
DS1997-1047
1997
Simons, J.Simons, J.Exploring risks to mining in underdeveloped countriesMining Engineering, Vol. 49, No. 2, Feb. pp. 9-10Brazil, PhilippinesEconomics, country risk, Mining
DS201012-0343
2010
Simons, M.Kanda, R.V.S., Simons, M.An elastic plate model for intraseismic deformation in subduction zones.Journal of Geophysical Research, Vol. 115, B3 B30405MantleSubduction
DS2002-0482
2002
Simonsen, S.L.Frezzotti, M.L., Andersen, T., Neumann, E.R., Simonsen, S.L.Carbonatite melt CO2 fluid inclusions in mantle xenoliths from Tenerife, Canary Islands:Lithos, Vol. 64, 3-4, pp. 77-96.Mantle, Canary IslandsCarbonatite
DS200412-1836
2004
Simonson, B.M.Simonson, B.M., Glass, B.P.Spherule layers - records of ancient impacts.Annual Review of Earth and Planetary Sciences, Vol. 32, May pp. 329-361.TechnologyOverview - spherule layers, geologic age
DS201212-0247
2012
Simonson, B.M.Glass, B.P., Simonson, B.M.Distal impact ejecta layers: spherules and more.Elements, Vol. 8, 1, Feb. pp. 43-48.MantleEjecta
DS200712-0991
2006
Simpson, C.D.Simpson, C.D.How and to what extent does the emergence of orogens above sea level influence their tectonic development?Terra Nova, Vol. 18, 6, pp. 447-451.MantleOrogeny
DS1990-1363
1990
Simpson, C.J.Simpson, C.J.Deep weathering, vegetation and fire burn significant obstacles forgeo science remote sensing in AustraliaInternational Journal of Remote Sensing, Vol. 11, No. 11, pp. 2019-2034AustraliaWeathering -general paper, Remote sensing
DS200812-1071
2008
Simpson, C.J.Simpson, C.J.Communicating environmental geoscience: Australian communication pathways.Geological Society of London Special Publication, No. 305, pp. 179-184.AustraliaSocial responsibility
DS1992-1408
1992
Simpson, D.W.Simpson, D.W., Andersm M.H.Tectonics and topography of the Western United States - an application Of digital mappingGsa Today, Vol. 2, No. 6, June pp. 117, 118, 120-121United StatesTectonics, Topography, GIS
DS201511-1847
2015
Simpson, E.Julian, B.R., Foulger, G.R., Hatfield, O., Jackson, S.E., Simpson, E., Einbeck, J., Moore, A.Hotspots in hindsight. Mentions kimberlitesGeological Society of America Special Paper, No. 514, pp. SPE514-08.MantleHotspots

Abstract: Thorne et al. (2004), Torsvik et al. (2010; 2006) and Burke et al. (2008) have suggested that the locations of melting anomalies ("hot spots") and the original locations of large igneous provinces ("LIPs") and kimberlite pipes, lie preferentially above the margins of two "large lower-mantle shear velocity provinces", or LLSVPs, near the bottom of the mantle, and that the geographical correlations have high confidence levels (> 99.9999%) (Burke et al., 2008, Fig. 5). They conclude that the LLSVP margins are "Plume-Generation Zones", and that deep-mantle plumes cause hot spots, LIPs, and kimberlites. This conclusion raises questions about what physical processes could be responsible, because, for example, the LLSVPs are apparently dense and not abnormally hot (Trampert et al., 2004). The supposed LIP-hot spot-LLSVP correlations probably are examples of the "Hindsight Heresy" (Acton, 1959), of performing a statistical test using the same data sample that led to the initial formulation of a hypothesis. In this process, an analyst will consider and reject many competing hypotheses, but will not adjust statistical assessments correspondingly. Furthermore, an analyst will test extreme deviations of the data, , but not take this fact into account. "Hindsight heresy" errors are particularly problematical in Earth science, where it often is impossible to conduct controlled experiments. For random locations on the globe, the number of points within a specified distance of a given curve follows a cumulative binomial distribution. We use this fact to test the statistical significance of the observed hot spot-LLSVP correlation using several hot-spot catalogs and mantle models. The results indicate that the actual confidence levels of the correlations are two or three orders of magnitude smaller than claimed. The tests also show that hot spots correlate well with presumably shallowly rooted features such as spreading plate boundaries. Nevertheless, the correlations are significant at confidence levels in excess of 99%. But this is confidence that the null hypothesis of random coincidence is wrong. It is not confidence about what hypothesis is correct. The correlations probably are symptoms of as-yet-unidentified processes.
DS1980-0310
1980
Simpson, E.L.Simpson, E.L.Mineralogy and Geochemistry of an Ocellar Minette Sill, Northern New Brunswick, Canada.Msc. Thesis, University New Brunswick, Canada, New BrunswickLamprophyres
DS1984-0125
1984
Simpson, E.L.Bachinski, S.W., Simpson, E.L.Ti Phlogopites of the Shaw's Cove Minette: a Comparison With Micas of Other Lamprophyres, Potassic Rocks, Kimberlites And Mantle Xenoliths.American MINERALOGIST., Vol. 69, No. 1-2, PP. 41-56.Canada, New BrunswickMineral Chemistry, Related Rocks, Analyses
DS1984-0126
1984
Simpson, E.L.Bachinski, S.W., Simpson, E.L.Chemistry and Crystal Morphology of Feldspars of Minettes, Other Lamprophyres and Potassic Lamproites.Geological Association of Canada (GAC), Vol. 9, P. 43. (abstract.).Canada, New Brunswick, Norway, ScandinaviaPetrography, Mineral Chemistry
DS1920-0252
1925
Simpson, E.S.Simpson, E.S.Contribution to the Mineralogy of Western AustraliaRoyal Society. WEST. AUST. Journal, SER. 1, Vol. 12, PP. 58-59.AustraliaDiamond, Leucite
DS1950-0083
1951
Simpson, E.S.Simpson, E.S.Minerals of Western Australia (1951)Perth: Government Printer., Australia, Western AustraliaDiamond, Kimberley
DS1983-0578
1983
Simpson, E.S.Simpson, E.S.Minerals of Western Australia (1981)Perth: Hesperian Press, 1, 900P.AustraliaKimberlite
DS1975-0409
1976
Simpson, F.Simpson, F.Evolution of a Graded Cretaceous ShelfProceedings SECOND International CONFERENCE ON BASEMENT TECTONICS, No. 2, PP. 423- 434.Montana, WyomingBasins, Mid-continent
DS2001-1081
2001
Simpson, F.Simpson, F.Resistance to mantle flow inferred from the electromagnetic strike of the Australian upper mantle.Nature, Vol. 6847, Aug. 9, pp. 632-4.AustraliaGeophysics - electromagnetic
DS2002-0091
2002
Simpson, F.Bahr, K., Simpson, F.Electrical anisotropy below slow and fast moving plates; paleoflow in the upper mantle?Science, No. 5558, Feb. 15, pp. 1270-1.MantleTectonics
DS2002-1492
2002
Simpson, F.Simpson, F.Intensity and direction of lattice preferred orientation of olivine: are electrical and seismic anisotropies of the Australian mantle reconcilable?Earth and Planetary Science Letters, Vol. 203, 1, pp. 535-47.AustraliaGeophysics - seismics, olivine
DS200512-0994
2005
Simpson, F.Simpson, F., Tommasi, A.Hydrogen diffusivity and electrical anisotropy of a peridotite mantle.Geophysical Journal International, Vol. 160, 3, pp. 1092-1102.MantleGeophysics
DS200512-0995
2005
Simpson, F.Simpson, F., Tommasi, A.Hydrogen diffusivity and electrical anisotropy of a peridotite mantle.Geophysical Journal International, Vol. 160, 3, pp. 1092-1102.MantlePeridotite
DS1996-1316
1996
Simpson, G.Simpson, G., et al.Thermochemical sulfate reduction: a local process that does not generate thermal anomalies.Ross, G.M. Lithoprobe Alberta, No. 51, pp. 241-245.AlbertaBasin -fluid inclusions, Homogenization temperatures
DS201412-0099
2014
Simpson, G.Caricchi, L., Annen, C., Blundy, J., Simpson, G., Pinel, V.Supervolcanoes erupt by their own rules. Mega-eruptions and smaller volcanoes are triggered by different mechanisms.Nature Geoscience, Jan. 5, 2p.MantleVolcanoes
DS1960-0026
1960
Simpson, H.S.Colvin, E., Simpson, H.S.Treatment and Recovery Practice at Kimberley Mines of de Beers Consolidated Limited.South African Institute of Mining and Metallurgy. Journal, Vol. 60, No. 10, PP. 503-524.South AfricaMining Methods, Recovery, Diamond, Kimberlite Pipes
DS1970-0124
1970
Simpson, H.S.Loftus, W.K.B., Simpson, H.S., King, M.J.Recovery Plant Practice at de Beers Consolidated Mines Limited, Kimberley with Particular Reference to Improvements Made for the Sorting of the Final Concentrates.South African Institute of Mining and Metallurgy. Journal, Vol. 80, No. 9, PP. 317-328.South AfricaDiamond Mining Recovery, Kimberlite Pipes
DS2001-1269
2001
Simpson, J.A.Xirouchakis, D., Hirschmann, M.M., Simpson, J.A.The effect of titanium on the silica content and on mineral liquid partitioning mantle equilibrated melts.Geochimica et Cosmochimica Acta, Vol. 65, No. 14, pp. 2201-2217.MantleMelting - not specific to kimberlites, Olivine, orthopyroxene saturated mafic
DS201812-2882
2018
Simpson, L.Simpson, L., Sinclair, S., Loescher, B.Short hold time parameters. Diavik mine water treatment plant.2018 Yellowknife Geoscience Forum , p. 74-75. abstractCanada, Northwest Territoriesdeposit - Diavik

Abstract: It is well known that it is very difficult to transport samples from remote locations to the laboratory and allow sufficient time to commence analysis within the prescribed short hold times for certain parameters. Also, the majority of published hold times are based on legacy as opposed to hard science. In an attempt to determine the validity of specific short hold times, a joint study between Diavik and Maxxam was undertaken. The purpose was to determine the stability of short hold time parameters over time using real samples from Diavik sites. Data from two sites will be presented. The first from the Diavik mine water treatment plant influent, which had relatively high levels of the target analytes. The second from a lake water sample with lower native levels of the target analytes. The parameters studied were ammonia (preserved and unpreserved), total nitrogen, nitrite, nitrate, phosphate, total phosphorus and turbidity. All target parameters have a prescribed 3-day hold time.1 pH was also monitored. Samples were collected by Diavik personnel in one-litre containers and extraordinary logistical measures were taken to get them to Maxxam's Burnaby laboratory as soon as possible. On receipt, they were immediately subsampled into appropriate containers. Each parameter (except pH and turbidity) was split into three containers: 1) as received; 2) low level spike added and 3) medium level spike added. All samples were analyzed within 3 at approximately 3-day intervals thereafter for a period of two weeks.
DS1988-0639
1988
Simpson, M.Simpson, M.Materials with the diamond touchNew Scientist, March 10, pp. 50-53GlobalBlank
DS1990-1046
1990
Simpson, M.A.Millard, M.J., Simpson, M.A., Schreiner, B.T., Edwards, W.A.D.Near surface mineral potential of the plains of Western Canada, with special reference to SaskatchewanModern Exploration Techniques, editors L.S. Beck, C.T. Harper, Saskatchewan, pp. 168-178SaskatchewanIndustrial minerals, Database
DS1990-1364
1990
Simpson, M.A.Simpson, M.A., Millard, M.J., Bedard, D.Geological and remote sensing investigations of the Prince Albert-Shellbrook area, SaskatchewanSaskatchewan Research Council, Publishing No. R-1200-2-E-90, 30p. approx. $ 30.00SaskatchewanRemote sensing, Prince Albert area
DS1991-1588
1991
Simpson, M.A.Simpson, M.A.Kimberlite indicator minerals in southwestern SaskatchewanSaskatchewan Research Council Publication report plus appendices on disc in, Publ.R-1210-8-E-91, 13p.text &approx.100 pages appendixSaskatchewanGeochemistry, indicator minerals, Kimberlite
DS1993-1469
1993
Simpson, M.A.Simpson, M.A.Kimberlite indicator minerals in southwestern SaskatchewanMid-continent diamonds Geological Association of Canada (GAC)-Mineralogical Association of Canada (MAC) Symposium ABSTRACT volume, held Edmonton May, pp. 53-58.SaskatchewanMineral chemistry
DS2002-1493
2002
Simpson, P.Simpson, P.A comparison of electromagnetic distortion and resolution upper mantle conductivities beneath EuropePhysics of the Earth and Planetary Interiors, Vol. 129, No. 1-2, pp. 117-30.Europe, MantleGeophysics
DS1991-1664
1991
Simpson, P.R.Stone, P., Green, P.M., Lintern, B.C., Plant, J.A., Simpson, P.R.Geochemistry characterizes provenance in southern ScotlandGeology Today, Vol. 7, No. 5, September/October pp. 177-181ScotlandGeochemistry, Geology
DS1994-0527
1994
Simpson, P.R.Flight, D.M.A., Hall, G.E.M., Simpson, P.R.Regional geochemical mapping of Platinum, Palladium, and gold over an obducted ophiolite complex, Shetland IslandsInstitute of Mining and Metallurgy (IMM) Bulletin, Vol. 103, pp. B68-78ScotlandGeochemistry, Platinum, palladium, gold
DS2003-1285
2003
Simpson, R.Simpson, R.Bureaucracy bogs down Mackenzie Valley EIR delaying Snap Lake permitsInfomine, Depth News, Jan 29, 1p.Northwest TerritoriesNews item, De Beers
DS2003-1286
2003
Simpson, R.Simpson, R.New Canadian diamond district in Nunavut. Melville PeninsulaInfomine, Feb 4, 1p.Northwest Territories, Melville PeninsulaNews item, Stornoway, Nothern Empire Minerals
DS200412-1837
2004
Simpson, R.Simpson, R.Endangered species: a shortage of geologists and geophysicists is fast approaching. So why isn't the industry doing anything toCanadian Diamonds, Summer, p. 16-17.CanadaNews item - shortage of geologists
DS200412-1838
2004
Simpson, R.Simpson, R.Social style of exploration. The Quebec government is a world leader in attracting exploration dollars. It's time other provinceCanadian Diamonds, Winter 2004, pp. 14, 16.Canada, QuebecNews item - taxation, expenses
DS200412-1839
2004
Simpson, R.Simpson, R.Diamonds add luster to Canadian economy.Resource World Magazine, Vol. 2, 5, July/August pp. 22,23.Canada, Northwest TerritoriesNews item - Ekati, Diavik
DS200512-0996
2005
Simpson, R.Simpson, R.Public benefits from exploration. Diamond exploration and mining play a fundamental role in preserving the cultural heritage of Canada's north.Canadian Diamonds, Winter pp. 18, 20.Canada, NunavutNews item - cultural heritage
DS1995-0800
1995
Simpson, R.W.Hildenbrand, T.G., Jachens, R.C., Simpson, R.W.Insights on lithospheric structures within the stable craton, USA based on magnetic and gravity data.Iagod Giant Ore Deposits Workshop, J. Kutina, 6p.MidcontinentCraton, Geophysics -magnetics, gravity
DS1997-0505
1997
Simpson, R.W.Hildenbrand, T.G., Jachens, R.C., Simpson, R.W.Insights on lithospheric structures within the stable craton USA, based on magnetic and gravity data.Global Tectonics and Metallogeny, Vol. 6, No. 2, March pp. 113-118.MidcontinentMantle structure, Geophysics - magnetics, gravity
DS1997-1118
1997
Simpson, R.W.Stuart, W.D., Hildenbrand, T.G., Simpson, R.W.Stressing of the New Madrid seismic zone by a lower crust detachmentfault.Journal of Geophysical Research, Vol. 102, No. 12, Dec. 10, pp. 27, 623-34.Midcontinent, Minnesota, WisconsinGeophysics, New Madrid Seismic Zone
DS1996-1033
1996
SimsNewsom, H.E., Sims, Noll, Jaeger, Maehr, BesserraThe depletion of tungsten in the bulk silicate earth: constraints on coreformation.Geochimica et Cosmochimica Acta, Vol. 60, No. 7, pp. 1155-69.MantleGeochemistry - bulk silicate EARTH backscatter electron (BSE) imaging ., Core formation
DS1994-1565
1994
Sims, J.L.Sears, J.W., Jacob, J.P., Poage, M.A., Sims, J.L., Skinner, L.L.Mid-continent rift analog for middle Proterozoic belt basinGeological Society of America Abstracts, Vol. 26, No. 6, April p. 62. Abstract.GlobalTectonics, Midcontinent
DS2003-1297
2003
Sims, K.Smith, C.B., Sims, K., Chimuka, L., Beard, A., Townend, R.Kimberlite metasomatism at Murowa and Sese pipes, Zimbabwe8ikc, Www.venuewest.com/8ikc/program.htm, Session 1 POSTER abstractZimbabweKimberlite geology and economics, Deposit - Murowa, Sese
DS200612-1310
2006
Sims, K.Sims, K., Standish, J.Integrated studies of MORB petrogenesis: sources, melting processes, and timescales.Goldschmidt Conference 16th. Annual, S4-06 theme abstract 1/8p. goldschmidt2006.orgMantleGeochemistry
DS200912-0703
2009
Sims, K.Smith, C.B., Pearson, D.G., Bulanova, G.P., Beard, A.D., Carlson, R.W., Wittig, N., Sims, K., Chimuka, L., Muchemwa, E.Extremely depleted lithospheric mantle and diamonds beneath the southern Zimbabwe Craton.Lithos, In press available, 41p.Africa, ZimbabweDeposit - Murowa, Sese
DS201812-2883
2018
Sims, K.Sims, K., Fox, K., Harris, M., Chimuka, L., Reichhardt, F., Muchemwa, E., Gowera, R., Hinks, D., Smith, C.B.Murowa deposit: Discovery of the Murowa kimberlites, Zimbabwe.Society of Economic Geology Geoscience and Exploration of the Argyle, Bunder, Diavik, and Murowa Diamond Deposits, Special Publication no. 20, pp. 359-378.Africa, Zimbabwedeposit - Murowa
DS1997-1048
1997
Sims, K.W.Sims, K.W., DePaolo, D.J.Inferences about mantle magma sources from incompatible element concentration ratios in oceanic basalts.Geochimica Et Cosmochimica Acta, Vol. 61, No. 4, pp. 765-84.MantleMagmatism, geochemistry
DS1992-1120
1992
Sims, K.W.W.Newsom, H.E., Sims, K.W.W.Chemical fractionation in the continental crust: clues from Arsenic(As), Antimony(Sb),Tungsten (W),and lead in lower crustal xenolithsV.m. Goldschmidt Conference Program And Abstracts, Held May 8-10th., p. A 75. abstractMantleCrust, Arsenic, Antimony, Tungsten,lead, Geochemistry -xenoliths
DS1992-1121
1992
Sims, K.W.W.Newson, H.E., Sims, K.W.W.Chemical fractionation in the continental crust: Archean crust versus lower crustal xenolithsEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p. 323MantleCrust, Xenoliths
DS200612-1311
2006
Sims, K.W.W.Sims, K.W.W., Hart, S.R.Comparison of Th, Sr Nd and Pb isotopes in oceanic basalts: implications for mantle heterogeneity and magma genesis.Earth and Planetary Science Letters, Vol. 245, 3-4, May 30, pp. 743-761.MantleGeochronology
DS200712-0868
2006
Sims, K.W.W.Ramos, F.C., Reid, M.R., Sims, K.W.W.Re-evaluating the mantle structure underlying the southwestern US.Geochimica et Cosmochimica Acta, In press availableUnited States, Colorado PlateauGeochronology
DS1975-0410
1976
Sims, P.K.Sims, P.K.Precambrian Tectonics and Mineral Deposits, Lake Superior Region.Economic Geology, Vol. 71, PP. 1092-1127.GlobalMid-continent
DS1980-0311
1980
Sims, P.K.Sims, P.K., et al.The Great Lakes Tectonic Zone- a Major Crustal Structure In central North America.Geological Society of America (GSA) Bulletin., Vol. 91, PT. 1, PP. 690-698.GlobalMid-continent, Geophysics, Rift
DS1981-0379
1981
Sims, P.K.Sims, P.K., Card, K.D., Lumbers, S.B.Evolution of Early Proterozoic Basins of Great Lakes RegionIn: Proterozoic Basins of Canada, Proceedings of Symposium Held Halifa, No. 81-10, PP. 379-397.GlobalMid-continent
DS1982-0447
1982
Sims, P.K.Morey, G.B., Sims, P.K., Cannon, W.F., Mudrey, M.G. JR., Southwick, D.L.Geologic map of the Lake Superior region Minnesota, Wisconsin and NorthernMichiganMinnesota Geological Survey, map No. S-13.1: 1 millionMinnesotaMap
DS1983-0579
1983
Sims, P.K.Sims, P.K.Extension of Exposed Precambrian Rocks in the Lake Superior region Into the Subsurface.Geological Society of America (GSA), Vol. 15, No. 6, P. 689. (abstract.).GlobalMid Continent
DS1984-0636
1984
Sims, P.K.Schulz, K.J., Laberge, G.L., Sims, P.K., Peterman, Z.E., Klasner.The Volcanic Plutonic Terrane of Northern Wisconsin: Implications for Early Proterozoic Tectonism, Lake Superior Region.Geological Association of Canada (GAC), Vol. 9, P. 103. (abstract.).MichiganMid-continent
DS1985-0617
1985
Sims, P.K.Sims, P.K.Precambrian Basement Map of the Midcontinent UsaUnited States Geological Survey (USGS) Open File, No. 85-604, 16p. 1 map. 1: 1, 000, 000 scale Black and whitUnited States, MidcontinentTectonics
DS1985-0618
1985
Sims, P.K.Sims, P.K., Peterman, Z.E.Early Proterozoic Tectonics in the North Central United States.Geological Society of America (GSA), Vol. 17, No. 7, P. 718. (abstract.).United States, Central States, Nebraska, Kansas, MissouriGeochronology, Midcontinent
DS1986-0740
1986
Sims, P.K.Sims, P.K., Peterman, Z.E.Early Proterozoic Central Plains orogen: a major buried structure in The north central United StatesGeology, Vol. 14, No. 6, June pp. 488-491MidcontinentTectonics
DS1987-0594
1987
Sims, P.K.Pratt, W.P., Sims, P.K.The U.S. Midcontinent: a new frontier for mineral explorationEpsiodes, Vol. 10, No. 4, December pp. 303-307United StatesTectonics, Mid-continent
DS1987-0682
1987
Sims, P.K.Sims, P.K.Geology and metallogeny of Archean and Proterozoic basement terranes In the northern midcontinent,USA- an overviewUnited States Geological Survey (USGS) Bulletin, No. 1815, 51pMidcontinentMetallogeny
DS1989-0082
1989
Sims, P.K.Barovich, K.M., Patchett, P.J., Peterman, Z.E., Sims, P.K.neodymium isotopes and the origin of 1.9-1.7 Ga Penokean continental crust of the Lake Superior regionGeological Society of America (GSA) Bulletin, Vol. 101, No. 3, March pp. 333-338OntarioGeochronology, Penokean-Lake Superior
DS1989-1394
1989
Sims, P.K.Sims, P.K.Geologic map of Proterozoic rocks near Mountain, Ocon to County, SOURCE[ United States Geological Survey (USGS) MapUnited States Geological Survey (USGS) Map, No. I-1903, 1: 24, 000 $ 3.10WisconsinMap, Proterozoic -Oconto County
DS1989-1395
1989
Sims, P.K.Sims, P.K., Van Schmus, W.R., Schulz, K.J., Peterman, Z.E.Tectono-stratigraphic evolution of the early Proterozoic Wisconsin magmatic terranes of the Penokean OrogenCanadian Journal of Earth Sciences, Vol. 26, No. 10, October pp. 2145-2158WisconsinStratigraphy, Orogeny -Penokean
DS1989-1396
1989
Sims, P.K.Sims, P.K., Van Schmus, W.R., Schulz, K.J., Peterman, Z.E.Tectono-stratigraphic evolution of the Early Proterozoic Wisconsin magmatic terranes of the Penokean OrogenCanadian Journal of Earth Sciences, Vol. 26, No. 10, October pp. 2145-2158WisconsinTectonics
DS1990-1194
1990
Sims, P.K.Pratt, W.P., Sims, P.K.The Midcontinent of the United States: permissive terrane for an olympic dam-type deposit?United States Geological Survey (USGS) Bulletin, No. B 1932, 81pMidcontinentCopper-uraniuM., Terrane
DS1990-1195
1990
Sims, P.K.Pratt, W.P., Sims, P.K.The Midcontinent of the United States; permissive terrane for an Olympic Dam type deposit?United States Geological Survey (USGS) Bulletin, No. 1932, 81p. $ 4.50MidcontinentTectonics, Structure
DS1990-1365
1990
Sims, P.K.Sims, P.K.The Great Lakes Tectonic Zone - a major north verging late Archean collision zoneInstitute on Lake Superior Geology Proceedings Volume, 36th. Annual Meeting held May 9-12, Thunder Bay pMichigan, OntarioMid continent, Tectonics -Great Lakes Te
DS1990-1366
1990
Sims, P.K.Sims, P.K.Precambrian basement map of the northern Midcontinent, United States (US)United States Geological Survey (USGS) Map, No. I-1853-A, 1: 1, 1000, 000 $ 3.10 supercedes OF85-604MidcontinentMap, Precambrian basement
DS1991-1589
1991
Sims, P.K.Sims, P.K.Great Lakes tectonic zone in Marquette area, Michigan: implications for Archean tectonics in north central United StatesUnited States Geological Survey (USGS) Bulletin, No. 1904-E. pp. E1-17MichiganTectonics, Great Lakes Tectonic Zone
DS1991-1590
1991
Sims, P.K.Sims, P.K.Precambrian geology of the Lake Superior region - an overviewMinnesota Geological Survey, Information Circular No. 34, pp. 1-9MinnesotaPrecambrian geology, overview - regional
DS1991-1591
1991
Sims, P.K.Sims, P.K., Peterman, Z.E., Hildenbrand, T.G., Mahan, S.Precambrian basement map of the Trans-Hudson Orogen and adjacent northern Great Plains, United States (US)United States Geological Survey (USGS), Map I 2214, 1: 1, 000, 000 $ 3.10Minnesota, Montana, Nebraska, WyomingPrecambrian, Map
DS1992-1409
1992
Sims, P.K.Sims, P.K.The Great Lakes tectonic zone revisitedGeological Society of America (GSA) Abstract Volume, Vol. 24, No. 4, April p. 64. abstract onlyMichiganGreat Lakes Tectonic Zone, Structure
DS1992-1410
1992
Sims, P.K.Sims, P.K.Geologic map of Precambrian rocks, southern Lake Superior region, Wisconsin and northern MichiganUnited States Geological Survey (USGS) Map, I-2185, two sheets $ 7.00Wisconsin, MichiganPrecambrian rocks, Map
DS1993-0210
1993
Sims, P.K.Cannon, W.F., Peterman, Z.E., Sims, P.K.Crustal scale thrusting and origin of the Montreal River monocline- a 35 KM thick cross section of the Midcontinent RiftTectonics, Vol. 12, No. 3, June pp. 728-744Wisconsin, MichiganTectonics, Structure
DS1993-1470
1993
Sims, P.K.Sims, P.K.Structure map of Archean rocks, Palmer Sands Quad. Michigan showing Great Lakes tectonic zoneUnited States Geological Survey (USGS) Map, Map I 2355, 1: 24, 000 $ 3.00MichiganTectonics, Structure
DS1994-1611
1994
Sims, P.K.Sims, P.K.Archean and early Proterozic tectonic framework of North Central UnitedStates.Geological Society of America Abstracts, Vol. 26, No. 6, April p. 63. Abstract.Wisconsin, WyomingTectonics
DS1994-1612
1994
Sims, P.K.Sims, P.K., Day, W.C.The Great Lakes tectonic zone- revisitedU.s. Geological Survey Bulletin, No. 1904, Chapter S, pp. S1-S 11Minnesota, Wisconsin, Great LakesTectonics
DS1994-1613
1994
Sims, P.K.Sims, P.K., Day, W.C.The Great Lakes tectonic zone- revisitedU.s. Geological Survey Bulletin, No. 1904, Chapter S, pp. S1-S 11.Minnesota, Wisconsin, Great LakesTectonics
DS1996-1317
1996
Sims, P.K.Sims, P.K., Carter, L.M.H.Archean and Proterozoic geology of Lake Superior region... Lake Ellenkimberlite... briefly mentioned.United States Geological Survey (USGS) Prof. Paper, No. 1556, pp. 93-94.MichiganKimberlite, geochronology, Deposit - Lake Ellen
DS1996-1318
1996
Sims, P.K.Sims, P.K., Day, W.C.The western continental margin of the early Proterozoic trans-Hudson orogen exposed in the Hartville Uplift.Geological Society of America, Abstracts, Vol. 28, No. 7, p. A-437.WyomingTectonics, Orogeny - Trans Hudson
DS2002-1494
2002
Sims, P.K.Sims, P.K.The Mesoproterozoic - a time of change in tectonic style and magma types in the North Atlantic continent.Geological Society of America Annual Meeting Oct. 27-30, Abstract p. 43.AppalachiaTectonics - Redfoot rift
DS2002-1495
2002
Sims, P.K.Sims, P.K., Finn, C.A., Rystrom, V.L.Preliminary Precambrian basement map showing geological geophysical domains, Wyoming.U.s.g.s. Open File, 01-0199, map.WyomingMap, Geophysics - geological
DS200512-0997
2004
Sims, P.K.Sims, P.K., Peterman, Z.E., Anderson, E.D.Early tectonic evolution of the North America continent - a model invoking subcontinental mantle deformation.Geological Society of America Annual Meeting ABSTRACTS, Nov. 7-10, Paper 244-2, Vol. 36, 5, p. 567.United States, CanadaTectonics
DS1990-1367
1990
Sims, R.W.Sims, R.W.Mine permitting: a lawyer's perspectiveAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint, No. 90-46, 3pFloridaLaw, Mine permits
DS1998-1506
1998
Sinclair, A.Vallee, M., Sinclair, A.Quality control of resource/reserve estimation - where do we go from here?The Canadian Mining and Metallurgical Bulletin (CIM Bulletin), Vol. 91, No. 1022, July/Aug. pp. 55-57CanadaGeostatistics, ore reserves, discoveries
DS1991-1592
1991
Sinclair, A.J.Sinclair, A.J.A fundamental approach to threshold estimation in exploration geochemistry:probability plots revisitedJournal of Geochemical Exploration -Geochemical Exploration 1989, part II, Vol. 41, No. 1-2, special issue, pp. 1-22GlobalGeochemistry, Computer applications - general probability plots
DS1992-0129
1992
Sinclair, A.J.Blackwell, G.H., Sinclair, A.J.Geostatistical mineral inventory using personal computersThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin), Vol. 85, No. 961, June pp. 65-70GlobalGeostatistics, Computer programs
DS1993-1471
1993
Sinclair, A.J.Sinclair, A.J., Vallee, M.Reviewing continuity: an essential element of quality control for depositand reserve estimationThe Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Annual Meeting Preprint, Paper No. 33, 9pCanadaOre reserve estimation, classification, Geostatistics
DS1994-1614
1994
Sinclair, A.J.Sinclair, A.J.Improved sampling control and dat a gathering for improved mineral inventories and production controlGeostatistics for the Next Century, pp. 323-329GlobalGeostatistics, Sampling control, reserve estimation
DS1997-1189
1997
Sinclair, A.J.Vallee, M., Sinclair, A.J.Efficient resource and reserve estimation depends on high quality geology and evaluation proceduresThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin), Vol. 90, No. 1011, June pp. 76-79GlobalGeostatistics, ore reserves, Evaluation, sampling
DS2002-0343
2002
Sinclair, G.Culshaw, N., Reynolds, P., Sinclair, G., Barr, S.Amphibole and mice40Ar 39Ar ages from the Kaipokok and Aillik domains, Makkovik Province, Labrador: towards a characterization of back arc processes.Canadian Journal of Earth Science, Vol.39,5, May, pp.749-64.LabradorPaleoproterozoic - mobile belt
DS2002-1496
2002
Sinclair, G.S.Sinclair, G.S., Barr, S.M., Culshaw, N.G., Ketchum, J.W.F.Geochemistry and age of the Aillik Group and associated plutonic rocks, MakkovikCanadian Journal of Earth Science, Vol.39,5, May, pp.731-48.LabradorTectonics
DS1997-1049
1997
Sinclair, H.D.Sinclair, H.D.Tectonostratigraphic model for under filled peripheral forelandbasins: an Alpine perspectiveGeological Society of America (GSA) Bulletin, Vol. 109, No. 3, March pp. 324-346EuropeTectonics, Foreland basins
DS1986-0396
1986
Sinclair, I.G.L.Janse, A.J.A., Downie, I.F., Reed, L.E., Sinclair, I.G.L.Alkaline diatremes in the Hudson Bay Lowlands, Canada,explorationmethods, petrology and geochemistryProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 469-471OntarioDiamond exploration
DS1986-0397
1986
Sinclair, I.G.L.Janse, A.J.A., Downie, I.F., Reef, L.E., Sinclair, I.G.L.Alkaline diatremes in the Hudson Bay Lowlands: explorationmethods, mineralogy, petrology and geochemistryFick ( Proceedings Of The Fourth International Kimberlite Conference), Abstract 1pOntario, James Bay LowlandsAlkaline rocks
DS1989-0699
1989
Sinclair, I.G.L.Janse, A.J.A., Downie, I.F., Reed, L.E., Sinclair, I.G.L.Alkaline intrusions in the Hudson Bay Lowlands, Canada: explorationmethods, petrologyGeological Society of Australia Inc. Blackwell Scientific Publishing, Special, No. 14, Vol. 2, pp. 1192-1203OntarioExploration techniques, Geophysics, Petrology
DS1991-1407
1991
Sinclair, I.G.L.Reed, L.E., Sinclair, I.G.L.The search for kimberlite in the James Bay Lowlands of OntarioThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin), Vol. 84, No. 947, March pp. 132-139OntarioGeophysics -kimberlite exploration, Geochemistry -kimberlite exploration
DS1994-1615
1994
Sinclair, I.G.L.Sinclair, I.G.L.The Le Tac intrusion: kimberlite or lamproite?Geological Association of Canada (GAC) Abstract Volume, Vol. 19, p. PosterQuebecLamproite, Le Tac
DS1984-0672
1984
Sinclair, N.Sinclair, N.Safmarine to Enter Offshore Diamond MiningLloyd's List., AUGUST 25TH.Southwest Africa, NamibiaBlank
DS1975-0869
1978
Sinclair, P.D.Sinclair, P.D., Tempelman-Kluit, D.J., Medaris, L.G.Lherzolite Nodules from a Pleistocene Cinder Cone in Central Yukon.Canadian Journal of Earth Sciences, Vol. 15, No. 2, PP. 220-226.Canada, YukonBlank
DS201812-2882
2018
Sinclair, S.Simpson, L., Sinclair, S., Loescher, B.Short hold time parameters. Diavik mine water treatment plant.2018 Yellowknife Geoscience Forum , p. 74-75. abstractCanada, Northwest Territoriesdeposit - Diavik

Abstract: It is well known that it is very difficult to transport samples from remote locations to the laboratory and allow sufficient time to commence analysis within the prescribed short hold times for certain parameters. Also, the majority of published hold times are based on legacy as opposed to hard science. In an attempt to determine the validity of specific short hold times, a joint study between Diavik and Maxxam was undertaken. The purpose was to determine the stability of short hold time parameters over time using real samples from Diavik sites. Data from two sites will be presented. The first from the Diavik mine water treatment plant influent, which had relatively high levels of the target analytes. The second from a lake water sample with lower native levels of the target analytes. The parameters studied were ammonia (preserved and unpreserved), total nitrogen, nitrite, nitrate, phosphate, total phosphorus and turbidity. All target parameters have a prescribed 3-day hold time.1 pH was also monitored. Samples were collected by Diavik personnel in one-litre containers and extraordinary logistical measures were taken to get them to Maxxam's Burnaby laboratory as soon as possible. On receipt, they were immediately subsampled into appropriate containers. Each parameter (except pH and turbidity) was split into three containers: 1) as received; 2) low level spike added and 3) medium level spike added. All samples were analyzed within 3 at approximately 3-day intervals thereafter for a period of two weeks.
DS201809-2116
2018
Sinclair, S.A.Wilson, D., Sinclair, S.A., Blowes, D.W., Amos,R.T., Smith, L., Sego, D.C.Diavik waste rock project: analysis of measured and simulated acid neutralization processes within a large scale field experiment.Goldschmidt Conference, 1p. AbstractCanada, Northwest Territoriesdeposit - Diavik

Abstract: The geochemical evolution of mine-waste rock often includes concurrent acid generation and neutralization processes. Deposition of mine-waste rock in large, oxygenated, and partially saturated piles can result in release of metals and decreased pH from weathering of sulfide minerals. Acid neutralization processes can often mitigate metals and pH impacts associated with sulfide oxidation. The Diavik Waste Rock Project included large field experiments (test piles built in 2006) conducted to characterize weathering of sulfide waste rock at a scale representative of full size waste-rock piles. Water samples from the unsaturated interior of one of the test piles, constructed of waste rock with ~0.05 wt.% S, were collected using soil water solution samplers and drains at the base of the pile. Field observations indicated pH decreased throughout the depth of the pile during 2008 and 2009 and that carbonate mineral buffering was entirely depleted by 2011 or 2012. Carbonate mineral exhaustion was accompanied by increased concentrations of dissolved Al and Fe in effluent samples collected at the basal drains. These results suggest that dissolution of Al and Fe(oxy)hydroxides occurred after the depletion of carbonate minerals following an acid neutralization sequence that is similar to observations made by previous researchers. A conceptual model of acid neutralization proceses within the pile, developed using physical and geochemical measurements conducted from 2008 to 2012, was used to inform reactive transport simulations conducted in 2017 to quantify the dominant acid neutralization processes within the test pile interior. Reactive transport simulations indicate that the conceptual model developed using the results of field samples provides a reasonable assessment of the evolution of the acid neutralization sequence.
DS1992-1411
1992
Sinclair, W.D.Sinclair, W.D., Jambor, J.L., Birkett, T.C.Rare earths and the potential for rare earth deposits in CanadaThe Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Exploration and Mining Geology, Vol. 1, No. 3, July pp. 265-282CanadaEconomics, overview, Rare earths
DS1993-0820
1993
Sinclair, W.D.Kirkham, R.V., Sinclair, W.D., Thorpe, R.I., Duke, J.M.Mineral deposit modelling ( proceedings of conference UNESCO held August1990)Geological Association of Canada (GAC), $ 40.00 plusGlobalBook -table of contents, Mineral deposit modeling
DS1993-1472
1993
Sinclair, W.D.Sinclair, W.D., Jambor, J.L., Birkett, T.C.Rare earth deposits in Canada: alkaline complexes as potential sources of rare earth elements.Rare earth Minerals: chemistry, origin and ore deposits, International Geological Correlation Programme (IGCP) Project, pp. 128-130. abstractCanadaAlkaline rocks, rare earth elements (REE).
DS1994-1616
1994
Sinclair, W.D.Sinclair, W.D., Richardson, D.G.Studies of rare metal deposits in the Northwest TerritoriesGeological Survey of Canada Bulletin, No. 475, 96p. $ 15.00Northwest TerritoriesAlkaline rocks, Rare earths
DS1994-1617
1994
Sinclair, W.D.Sinclair, W.D., Richardson, J.M., Heagy, A.E., Garson, D.Mineral deposits of Canada -preliminary map and deposit listGeological Survey of Canada Open file, No. 2874, 34p. 1 disk. total cost $ 47.30CanadaMineral deposit listing, Map
DS1995-0478
1995
Sinclair, W.D.Eckstrand, O.R., Sinclair, W.D., Thorpe, R.I.Geology of Canadian mineral deposit typesGeological Survey of Canada Geology of Canada, No. 8, 650p. $ 70.00 or $ 91.00. plus postageCanadaMineral deposits, Table of contents
DS1995-0951
1995
Sinclair, W.D.Kikrham, R.V., Sinclair, W.D., Thorpe, R.I., Duke, J.M.Mineral deposit modelingGeological Association of Canada (GAC) Special Paper, No. 40, 800pGlobalMineral deposit modeling, Resources, economics, SEDEX, VMS, Magmatic, hydrothermal
DS1995-1762
1995
Sinclair, W.D.Sinclair, W.D., Richardson, D.G.Studies of rare metal deposits in the Northwest TerritoriesGeological Survey of Canada Bulletin, No. 475, $ 12.00Northwest TerritoriesPegmatites, Magmatism, Deposit -Thor Lake
DS200412-1187
2004
Sinclair, W.D.Lydon, J.W., Goodfellow, W.D., Dube, B., Paradis, S., Sinclair, W.D., Corrivea, L., Gosselin, P.A preliminary overview of Canada's mineral resources. ( Diamond mentioned).Geological Survey of Canada, Open File 4668, 1 CD $ 20.00 ( pfd of poster, 20p. reptCanadaPoster - resources
DS1950-0302
1956
Sinclair, W.E.Sinclair, W.E.Bechuanaland: a Potential Mineral FieldRhodesian Journal of Mining, Vol. 28, No. 335, P. 374. ALSO: MINING MAGAZINE, Vol. 95, NOBotswanaDiamond Prospecting
DS2002-0372
2002
Sindem, S.Demeny, A., Zaitsev, A.N., Wall, F., Sindem, S., Sitnikova, M.A., KarchevskyCarbon and isotope compositions of carbonatite complexes from the Kola Peninsula, Russia.18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.252.Russia, Kola PeninsulaCarbonatite - mineralogy
DS2001-0615
2001
Sinden, S.Koerner, T., Sinden, S., Kramm, U.Mineral chemistry in fenites of Kalk field carbonatite Complex and bearing on composition of fenitising fluid.Journal of South African Earth Sciences, Vol. 32, No. 1, p. A 23 (abs)NamibiaCarbonatite, Kalkfield Complex
DS1997-0632
1997
Sindern, S.Kramm, U., Sindern, S.neodymium Strontium isotope signatures of fenites from Oldoinyo Langai - a contribution to the discussion -genesisGeological Association of Canada (GAC) Abstracts, TanzaniaCarbonatite, nephelinites, phonolites, Deposit - Oldoinyo Lengai
DS1997-1050
1997
Sindern, S.Sindern, S., Kramm, U.Cancrinite in ultrafenites: a critical mineral for rheomorphic formation of alkaline melts in Iivaara...Geological Association of Canada (GAC) Abstracts, FinlandAlkaline rocks, Deposit - Iivaara
DS1998-0804
1998
Sindern, S.Kramm, U., Sindern, S.neodymium and Strontium isotope signatures of fenites from Oldoinyo Lengai, Tanzania and the genetic relationship ...Journal of Petrology, Vol. 39, No. 11-12, Nov-Dec. pp. 1997-2004TanzaniaCarbonatite, nephelinites, phonolites, genesis, Deposit - Oldoinyo Lengai
DS2001-0631
2001
Sindern, S.Kramm, U., Sindern, S., Downes, H.Timing of magmatism in the Kola alkaline province and the translation of isotope dates - geological processesJournal of South African Earth Sciences, Vol. 32, No. 1, p. A 23 (abs)Russia, Kola Peninsula, Baltic ShieldCarbonatite, Kola
DS2001-1082
2001
Sindern, S.Sindern, S., Kramm, U.Is there a Strontium and neodymium isotopic fingerprint of alkaline metasomatism?Journal of South African Earth Sciences, Vol. 32, No. 1, p. A 33.(abs)GlobalCarbonatite, Magmatism, geochronology - data
DS2002-1769
2002
Sindern, S.Zaitsev, A.N., Demeny, A., Sindern, S., Wall, F.Burbankite group minerals and their alteration in rare earth carbonatites - source of elements and fluids....Lithos, Vol.62,1-2,pp.15-33., Vol.62,1-2,pp.15-33.Russia, Kola PeninsulaGeochronology, Deposit - Khibina, Vuoriyarvi complex
DS2002-1770
2002
Sindern, S.Zaitsev, A.N., Demeny, A., Sindern, S., Wall, F.Burbankite group minerals and their alteration in rare earth carbonatites - source of elements and fluids....Lithos, Vol.62,1-2,pp.15-33., Vol.62,1-2,pp.15-33.Russia, Kola PeninsulaGeochronology, Deposit - Khibina, Vuoriyarvi complex
DS200412-1840
2004
Sindern, S.Sindern, S., Zaitsev, A.N., Demeny, A., et al.Mineralogy and geochemistry of silicate dyke rocks associated with carbonatites from the Khibin a complex, Kola Russia - isotopeMineralogy and Petrology, Vol. 80, 3-4, March pp. 215-239.Russia, Kola PeninsulaCarbonatite
DS201705-0843
2017
Sindern, S.Kramm, U., Korner, T., Kittel, M., Baier, H., Sindern, S.Triassic emplacement age of the Kalkfeld complex, NW Namibia: implications for carbonatite magmatism and its relationship to the Tristan Plume.International Journal of Earth Sciences, in press available 17p.Africa, NamibiaAlkaline rocks

Abstract: Rb-Sr whole-rock and mineral isotope data from nepheline syenite, tinguaite, and carbonatite samples of the Kalkfeld Complex within the Damaraland Alkaline Province, NW Namibia, indicate a date of 242?±?6.5 Ma. This is interpreted as the age of final magmatic crystallization in the complex. The geological position of the complex and the spatially close relationship to the Lower Cretaceous Etaneno Alkaline Complex document a repeated channeling of small-scale alkaline to carbonatite melt fractions along crustal fractures that served as pathways for the mantle-derived melts. This is in line with Triassic extensional tectonic activity described for the nearby Omaruru Lineament-Waterberg Fault system. The emplacement of the Kalkfeld Complex more than 100 Ma prior to the Paraná-Etendeka event and the emplacement of the Early Cretaceous Damaraland intrusive complexes excludes a genetic relationship to the Tristan Plume. The initial eSr-eNd pairs of the Kalkfeld rocks are typical of younger African carbonatites and suggest a melt source, in which EM I and HIMU represent dominant components.
DS201711-2523
2017
Sindern, S.Kramm, U., Korner, T., Kittel, M., Baier, H., Sindern, S.Triassic emplacement age of the Kalkfeld complex, NW Namibia: implications for carbonatite magmatism and its relationship to the Tristan Plume.International Journal of Earth Sciences, Vol. 106, pp. 2797-2813.Africa, Namibiacarbonatites

Abstract: Rb-Sr whole-rock and mineral isotope data from nepheline syenite, tinguaite, and carbonatite samples of the Kalkfeld Complex within the Damaraland Alkaline Province, NW Namibia, indicate a date of 242?±?6.5 Ma. This is interpreted as the age of final magmatic crystallization in the complex. The geological position of the complex and the spatially close relationship to the Lower Cretaceous Etaneno Alkaline Complex document a repeated channeling of small-scale alkaline to carbonatite melt fractions along crustal fractures that served as pathways for the mantle-derived melts. This is in line with Triassic extensional tectonic activity described for the nearby Omaruru Lineament-Waterberg Fault system. The emplacement of the Kalkfeld Complex more than 100 Ma prior to the Paraná-Etendeka event and the emplacement of the Early Cretaceous Damaraland intrusive complexes excludes a genetic relationship to the Tristan Plume. The initial eSr-eNd pairs of the Kalkfeld rocks are typical of younger African carbonatites and suggest a melt source, in which EM I and HIMU represent dominant components.
DS201803-0459
2018
Sindern, S.Kramm, U., Korner, T., Kittel, M., Baier, H., Sindern, S.Triassic emplacement age of Kakfeld complex, NW Namibia: implications for carbonatite magmatism and its relationship to the Tristan plume.International Journal of Earth Sciences, Vol. 106, 8, pp. 2797-2813.Africa, Namibiacarbonatite

Abstract: Rb-Sr whole-rock and mineral isotope data from nepheline syenite, tinguaite, and carbonatite samples of the Kalkfeld Complex within the Damaraland Alkaline Province, NW Namibia, indicate a date of 242 ± 6.5 Ma. This is interpreted as the age of final magmatic crystallization in the complex. The geological position of the complex and the spatially close relationship to the Lower Cretaceous Etaneno Alkaline Complex document a repeated channeling of small-scale alkaline to carbonatite melt fractions along crustal fractures that served as pathways for the mantle-derived melts. This is in line with Triassic extensional tectonic activity described for the nearby Omaruru Lineament-Waterberg Fault system. The emplacement of the Kalkfeld Complex more than 100 Ma prior to the Paraná-Etendeka event and the emplacement of the Early Cretaceous Damaraland intrusive complexes excludes a genetic relationship to the Tristan Plume. The initial ?Sr-?Nd pairs of the Kalkfeld rocks are typical of younger African carbonatites and suggest a melt source, in which EM I and HIMU represent dominant components.
DS1988-0640
1988
Sindeyev, A.S.Sindeyev, A.S.New shoshonite province in northeastern USSRDoklady Academy of Science USSR, Earth Science Section, Vol. 294, No. 1-6, October pp. 116-118RussiaShoshonite
DS1996-1319
1996
Sinding, K.Sinding, K., Poulin, R., MacDonald, D.Property rights for mineral resourcesJournal of Mineral Policy, Vol. 12, No. 1, pp. 24-29GlobalLegal, Mineral resources - property rights
DS1996-1320
1996
Sinding, K.Sinding, K., Poulin, R., MacDonald, D.Property rights for mineral resources.... not specific to diamonds but ofinterest.Journal of Mineral Policy, Vol. 12, No. 1, pp. 24-29.GlobalLegal, Property rights
DS1999-0672
1999
Sinding, K.Sinding, K.Environmental impact assessment and management in the mining industryNatural Res. forum, Vol. 23, pp. 57-63.GlobalMining - environmental, Not specific to diamonds
DS200512-0998
2005
Sinding, K.Sinding, K.The dynamics of artisanal and small scale mining reform.Natural Resources Forum, Vol. 29, 3, August pp. 243-252.GlobalNews item - economics
DS1970-0633
1973
Sinding-Larsen, R.Bolviken, B., Sinding-Larsen, R.Total Error and Other Criteria in the Interpretation of Stream Sediment Data.Unknown, PP. 285-296.IndiaGeochemistry
DS1991-1593
1991
Sinding-Larsen, R.Sinding-Larsen, R., et al.Structural interpretation of the Okavango Basin (South Central Africa) from multisatillite imageryProceedings of the Eighth Thematic Conference on Geologic Remote, Vol. I, pp. 597-604GlobalRemote sensing, Structure
DS1994-0295
1994
Sinding-Larsen, R.Chen, Zhuocheng, Sinding-Larsen, R.Discovery process modelling - a sensitivity studyNonrenewable Resources, Vol. 3, No. 4, Winter pp. 295-303GlobalGeostatistics, Model -discovery efficiency
DS200812-1240
2008
Sine, C.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
DS200812-1072
2008
Sine, C.R.Sine, C.R., Wilson, D., Gao, W., Grand, S.P., Aster, R., Ni, J., Baldridge, W.S.Mantle structure beneath the western edge of the Colorado Plateau.Geophysical Research Letters, Vol. 35, 10, May 28, L10303.United States, Colorado PlateauTectonics
DS200712-0992
2007
Siner, S.F.Siner, S.F.Global warming: man-made or natural?Imprints ( Hillsdale College), Vol. 36, 8, August 5p. www.hillsdale.eduGlobalEnvironmental overview
DS201906-1347
2019
Sing, T.D.Sing, T.D., Manikyamba, C., Tang, L., Khelen, A.Phanerozoic magmatism in the Proterozoic Cuddapah basin and its connection with the Pangean supercontinent.Geoscience Frontier, doi.org/10.1016/ j.gsf.2019.04.001Indiamagmatism

Abstract: Magmatic pulses in intraplate sedimentary Basins are windows to understand the tectonomagmatic evolution and paleaoposition of the Basin. The present study reports the U-Pb zircon ages of mafic flows from the Cuddapah Basin and link these magmatic events with the Pangean evolution during late Carboniferous-Triassic/Phanerozoic timeframe. Zircon U-Pb geochronology for the basaltic lava flows from Vempalle Formation, Cuddapah Basin suggests two distinct Phanerozoic magmatic events coinciding with the amalgamation and dispersal stages of Pangea at 300 Ma (Late Carboniferous) and 227 Ma (Triassic). Further, these flows are characterized by analogous geochemical and geochronological signatures with Phanerozoic counterparts from Siberian, Panjal Traps, Emeishan and Tarim LIPs possibly suggesting their coeval and cogenetic nature. During the Phanerozoic Eon, the Indian subcontinent including the Cuddapah Basin was juxtaposed with the Pangean LIPs which led to the emplacement of these pulses of magmatism in the Basin coinciding with the assemblage of Pangea and its subsequent breakup between 400 Ma and 200 Ma.
DS1991-1594
1991
Singaraju, V.Singaraju, V., et al.Quaternary geology and geomorphological studies for diamond in lower Saileru Basin, Prakasam and Cuddapah District, Andhra Pradesh.Records Geological Survey of India, Vol. 124, pt. 5, pp. 45-47.IndiaAlluvials, Diamonds
DS2002-0329
2002
Singer, B.S.Costa, P., Dungan, M.A., Singer, B.S.Hornblende and phlogopite bearing gabbroic xenoliths from Volcan San Pedro... evidence for melt and fluid..Journal of Petrology, Vol. 43, No. 2, pp. 219-42.Chile, AndesMigration, reactions subducted related plutons
DS2003-0925
2003
Singer, B.S.Medaris, L.G., Singer, B.S., Dott, R.H., Naymark, A., Johnson, C.M., SchottLate Paleoproterozoic climate, tectonics and metamorphism in the southern LakeJournal of Geology, Vol. 111, 3, pp. 243-258.MichiganTectonics
DS200412-1286
2003
Singer, B.S.Medaris, L.G., Singer, B.S., Dott, R.H., Naymark, A., Johnson, C.M., Schott, R.C.Late Paleoproterozoic climate, tectonics and metamorphism in the southern Lake Superior region and proto North America: evidenceJournal of Geology, Vol. 111, 3, pp. 243-258.United States, MichiganTectonics
DS200512-0439
2004
Singer, B.S.Hoffman, K.A., Singer, B.S.Regionally recurrent paleomagnetic transitional fields and mantle processes.American Geophysical Union, No. 145, pp. 233-244.MantleGeophysics - paleomagnetics
DS200812-0479
2008
Singer, B.S.Hoffman, K.A., Singer, B.S.Magnetic source separation in Earth's outer core.Science, Vol. 321, 5897 p. 1800.MantleGeophysics - magnetics, boundary
DS1986-0741
1986
Singer, D.A.Singer, D.A.Descriptive model of carbonatite deposits. Grade and tonnage model of carbonatite depositsUnited States Geological Survey (USGS) Bulletin, No. 1693, pp. 51-53GlobalCarbonatite
DS1992-0256
1992
Singer, D.A.Chung, C.F., Jefferson, C.W., Singer, D.A.A quantitative link among mineral deposit modelling, geoscience mapping and exploration resource assessmentEconomic Geology, Vol. 87, No. 1, Jan-Feb. pp. 194-197GlobalMineral exploration, ore reserves, Mineral deposit modeling
DS1993-1473
1993
Singer, D.A.Singer, D.A.Basic concepts in three part quantitative assessments of undiscovered mineral resourcesNonrenewable Resources, Vol. 2, No. 2, Summer pp. 69-81GlobalOre reserves, mineral deposit models, Economics, grade and tonnage
DS1994-1618
1994
Singer, D.A.Singer, D.A.Conditional estimates of the number of podiform chromite depositsNonrenewable Resources, Vol. 3, No. 4, Fall pp. 200-204California, OregonPodiform chromites
DS1997-1051
1997
Singer, D.A.Singer, D.A., Kouda, R.Classification of mineral deposits into types using mineralogy with aprobalistic neural networkNonrenewable Resources, Vol. 6, No. 1, March pp. 26-32GlobalModel - geostatistics, classification, Bayes theory
DS200812-1073
2008
Singer, D.A.Singer, D.A.Mineral deposit densities for estimating mineral resources.Mathematical Geology, Vol. 40, pp. 33-46.TechnologyNot specific to diamonds
DS201112-0084
2009
Singer, D.A.Berger, V.I., Singer, D.A., Orris, G.J.Carbonatites of the world - explored deposits of Nb and REE - database and grade and tonnage models.U.S. Geological Survey, GlobalCarbonatite
DS201112-0966
2010
Singer, D.A.Singer, D.A.Progress in integrated quantitative mineral resource assessments.Ore Geology Reviews, Vol. 38, pp. 242-250.TechnologyMethodology - computing
DS201112-0967
2011
Singer, D.A.Singer, D.A., Kouda, R.Probabilistic estimates of number of undiscovered deposits and their total tonnages in permissive tracts using deposit densities.Natural Resources Research, Vol. 20, 2, June pp. 89-94.TechnologyEconomics - not specific to diamonds
DS201312-0827
2013
Singer, D.A.Singer, D.A.The log normal distribution of metals resources in mineral deposits. ** not applicable to diamonds but of interestOre Geology Reviews, Vol. 55, pp. 80-86.TechnologyResource evaluation
DS1910-0589
1919
Singewald, J.T.Miller, B.L., Singewald, J.T.Diamonds in Brasil and British GuianaNew York: Mcgraw Hill, 598P. 1ST. EDITION.Brazil, South America, Guyana, GuianaDiamonds
DS1930-0041
1930
Singewald, J.T.Singewald, J.T., Milton, C.An Alnoite Pipe, its Contact Phenomena and Ore Deposition Near Avon, missouri.Journal of Geology, Vol. 38, No. 1, PP. 54-66.Missouri, United States, Central StatesRelated Rocks, Diatreme
DS1930-0011
1930
Singewald, J.T.Jr.Ball, S.H., Singewald, J.T.Jr.An Alnoite Pipe, its Contact Phenomena and Ore Deposition Near Avon, missouri. a DiscussionJournal of Geology, Vol. 38, No. 5, PP. 456-459.Missouri, United States, Central StatesAlnoite, Related Rocks, Diatreme
DS1998-1322
1998
SinghShanker, R., Singh, Kumar, MathyPre-Gondwana events and evolution of the Indian subcontinent as part ofGondwana.Journal of African Earth Sciences, Vol. 27, 1A, p. 178. AbstractIndiaTectonics
DS2001-1057
2001
SinghShanker, R., Nag, S., Ganguly, A., Absar, Rawat, SinghAre Majhgawan Hinota pipe rocks truly group I kimberlite?Indian Acad. Sciences Earth and Plan., Vol. 110, No. 1, pp. 63-76.IndiaKimberlite - classification, Deposit - Majhgawan
DS201506-0296
2015
SinghSingh, SlabunovThe central Bundelk hand Archean greenstone complex, Bundlekhand Craton, central India: geology, composition and geochronology of supracrustal rocks.International Geology Review, Vol. 57, 11-12, pp. 1349-1364.IndiaCraton
DS200412-1055
2004
Singh, A.Krishnakanta, Singh, A.Geochemistry and petrogenesis of granite in Kundal area, Malani igneous suite, western Rajasthan.Journal Geological Society of India, Vol. 60, 2, pp. 183-192.IndiaTectonics
DS200612-1312
2006
Singh, A.Singh, A., Kumar, M.R., Raju, P.S., Ramesh, D.S.Shear wave anisotropy of the northeast Indian lithosphere.Geophysical Research Letters, Vol. 33, 16, August 28, L16302.IndiaGeophysics - seismics
DS200712-1123
2007
Singh, A.Vinnik, L., Singh, A., Kiselev, S., Kumar, M.R.Upper mantle beneath foothills of the western Himalaya: subducted lithospheric slab or keel of the Indian Shield?Geophysical Journal International, Vol. 171, 3, Dec. pp. 1162-1171.AsiaIndia-Eurasia zone
DS200812-0573
2008
Singh, A.Kiselev, S., Vinnik, L., Oreshin, S., Gupta, S., Rai, S.S., Singh, A., Kumar, Mohan.Lithosphere of the Dharwar craton by joint inversion of P and S receiver functions.Geophysical Journal International, In press ( available)IndiaGeophysics - seismics
DS200912-0478
2009
Singh, A.Masun, K., Sthapak, A.V., Singh, A., Vaidya, A., Krishna, C.Exploration history and geology of the Diamondiferous ultramafic Saptarshi intrusions, Madhya Pradesh, India.Lithos, In press available, 37p.IndiaBunder project area
DS201312-0733
2013
Singh, A.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
DS201412-0833
2014
Singh, A.Singh, A., Mercier, J-P., Ravi Kumar, M., Srinagesh, D., Chadha, R.K.Continental scale body wave tomography of India: evidence for attrition and preservation of lithospheric roots.Geochemistry, Geophysics, Geosystems: G3, Vol. 15, 3, pp. 658-675.IndiaGeophysics - seismics
DS201504-0218
2015
Singh, A.Singh, A., Singh, C., Kennett, B.L.N.A review of crust and upper mantle structure beneath the Indian subcontinent.Tectonophysics, Vol. 644-645, pp. 1-21.IndiaGeophysics - seismics, geothermometry
DS201806-1242
2018
Singh, A.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
Singh, A.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.
DS201507-0338
2015
Singh, A.K.Upadhyay, D., Kooijman, E., Singh, A.K., Mezger, K., Berndt, J.The basement of the Deccan Traps and its Madagascar connection: constraints from xenoliths.Journal of Geology, Vol. 123, pp. 295-310.Africa, MadagascarXenoliths
DS200412-1841
2004
Singh, A.P.Singh, A.P., Mishra, D.C., Gupta, S.B., Rao, M.R.K.Crustal structure and domain tectonics of the Dharwar Craton ( India): insights from new gravity data.Journal of Asian Earth Sciences, Vol. 23, 1, March pp. 141-152.IndiaTectonics, geophysics - gravity, continental collision
DS201112-0715
2011
Singh, A.P.Nageswara Rao, B., Kumar, N., Singh, A.P., Prabhakar Rao, M.R.K., Mall, D.M., Singh, B.Crustal density structure across the Central Indian shear zone from gravity data.Journal of Asian Earth Sciences, Vol. 42, 3, pp. 341-353..IndiaGeophysics - Bundelkhand Craton
DS201412-0488
2014
Singh, A.P.Kumar, N., Zeyen, H., Singh, A.P.3D lithosphere density structure of Southern Indian shield from joint inversion of gravity, geoid and topography data.Journal of Asian Earth Sciences, Vol. 89, pp. 98-107.IndiaGeophysics - seismics
DS201511-1880
2015
Singh, A.P.Singh, A.P., Kumar, N., Zeyen, H.Three dimensional lithospheric mapping of the eastern Indian Shield: a multi-parametric inversion approach.Tectonophysics, Vol. 665, pp. 164-176.IndiaGeophysics - seismics

Abstract: We analyzed satellite gravity and geoid anomaly and topography data to determine the 3D lithospheric density structure of the Singhbhum Protocontinent. Our density model shows that distinct vertical density heterogeneities exist throughout the lithosphere beneath the Singhbhum Protocontinent. The crustal structure identified includes a lateral average crustal density variation from 2800 to 2890 kg/m3 as well as a relatively flat Moho at 35-40 km depth in Singhbhum Protocontinent and Bastar Craton. A similar Moho depth range is found for the Mahanadi, Damodar, and Bengal basins. In the northern part of the area, Moho undulates between more than 40 km under the confluence of Mahanadi-Damodar Gondwana basins and the Ganga foreland basin, and 36-32 km under the Eastern Ghats Mobile belt and finally reaches 24 km in the Bay of Bengal. The lithosphere-asthenosphere boundary (LAB) across the Singhbhum Protocontinent is at a depth of about 130-140 km. In the regions of Bastar Craton and Bengal Basin, the LAB dips to about 155 ± 5 km depth. The confluence of Mahanadi and Damodar Gondwana basins toward the north-west and the foreland Ganga Basin toward the north are characterized by a deeper LAB lying at a depth of over 170 and 200 km, respectively. In the Bay of Bengal, the LAB is at a shallower depth of about 100-130 km except over the 85 0E ridge (150 km), and off the Kolkata coast (155 km). Significant density variation as well as an almost flat crust-mantle boundary indicates the effect of significant crustal reworking. The thin (135-140 km) lithosphere provides compelling evidence of lithospheric modification in the Singhbhum Protocontinent. Similarities between the lithospheric structures of the Singhbhum Craton, Chhotanagpur Gneiss Complex, and Northern Singhbhum Mobile Belt confirm that the repeated thermal perturbation controlled continental lithospheric modification in the Singhbhum Protocontinent.
DS200512-0190
2005
Singh, B.Cornelius, M., Singh, B., Meyer, S., Smith, R.E., Cornelius, A.J.Laterite geochemistry applied to diamond exploration in the Yilgarn Craton, western Australia.Geochemistry, Exploration and Environmental Analysis, Vol. 5, pp.291-310.Australia, South America, Brazil, Minas GeraisGeochemistry - Aries, Coromandel
DS200612-1313
2006
Singh, B.Singh, B., Cornelius, M.Geochemistry and mineralogy of the regolith profile over the Aries kimberlite pipe, Westerm Australia.Geochemistry: Exploration, Environment, Analysis, Vol. 6, 4, pp. 311-323.AustraliaDeposit - Aries
DS201112-0715
2011
Singh, B.Nageswara Rao, B., Kumar, N., Singh, A.P., Prabhakar Rao, M.R.K., Mall, D.M., Singh, B.Crustal density structure across the Central Indian shear zone from gravity data.Journal of Asian Earth Sciences, Vol. 42, 3, pp. 341-353..IndiaGeophysics - Bundelkhand Craton
DS201312-0521
2013
Singh, B.Kumar, M.R., Mishra, D.C., Singh, B., Venkat Raju, D.Ch., Singh, M.Geodynamics of NW India: subduction, lithospheric flexure , ridges and seismicity.Journal Geological Society of India, Vol. 81, pp. 61-78.IndiaGravity - bouguer
DS1990-1368
1990
Singh, B.P.Singh, B.P., Gupta, S.K., Dhawan, U., Lal, K.Characterization of synthetic diamonds by EPR and X-raydiffractiontechniquesJournal of Material Science, Vol. 25, No. 28, February pp. 1487-1490GlobalDiamond synthesis, EPR and X-ray diffraction
DS201412-0302
2013
Singh, B.P.Gokarn, S.G., Rao, C.K., Selvaraj, C., Gupta, G., Singh, B.P.Crustal evolution and tectonics of the Archean Bundelk hand craton, central India.Journal of the Geological Society of India, Vol. 82, No. 5, pp. 455-460.IndiaTectonics
DS201504-0218
2015
Singh, C.Singh, A., Singh, C., Kennett, B.L.N.A review of crust and upper mantle structure beneath the Indian subcontinent.Tectonophysics, Vol. 644-645, pp. 1-21.IndiaGeophysics - seismics, geothermometry
DS1992-1588
1992
Singh, D.P.Upadhyay, O.P., Singh, D.P.Effect of discontinuities on the stability of slopes in opencast Mines by equivalent material modelling techniquesInternational Journal of Surface Mining and Reclamation, Vol. 6, pp. 99-102GlobalComputer, Program -open pit
DS1970-0417
1971
Singh, G.D.Singh, G.D.Recovery of Diamonds from Majhgawan TuffIndia Geological Survey Miscellaneous Publishing, No. 19, PP. 169-175.India, Madhya PradeshMining Engineering
DS1960-0276
1962
Singh, H.N.Mathur, S.M., Singh, H.N.Geology and Sampling of the Majhgawan Diamond Deposit, Panna District, Madhya Pradesh.India Geological Survey Bulletin. Ser. A, Economic Geology, No. 21, 59P. INDIA Geological Survey RECORDS, Vol. 87, PT. 4, PP.India, Madhya PradeshProspecting, Sampling
DS1970-0348
1971
Singh, H.N.Mathur, S.M., Singh, H.N.Petrology of the Majhgawan Pipe RockIndia Geological Survey Miscellaneous Publishing, No. 19, PP. 78-85.India, Madhya PradeshPetrology
DS1996-1321
1996
Singh, I.B.Singh, I.B., et al.Geochemistry, petrogenesis and tectonic setting of Proterozoic mafic dykeswarms, Eastern Dharwar CratonJournal of Geological Society India, Vol. 47, No. 5, May, ppIndiaDike swarms
DS2002-0010
2002
Singh, I.B.Agarwal, K.K., Singh, I.B., Sharma, M., Sharma, S., Rajagopalan, G.Extensional tectonic activity in the cratonward parts ( peripheral bulge) of the Ganga Plain foreland basin, India.International Journal of Earth Sciences, Vol. 91, 5, pp. 897-905.IndiaTectonics - not specific to diamonds
DS200412-1844
2004
Singh, K.D.P.Singh, Y., Singh, K.D.P., Prasad, R.N.Rb Sr whole rock isochron age of early Proterozoic potassic granite from Dharmawaram, Karimnagar district, Andhra Pradesh.Journal Geological Society of India, Vol. 64, 1, pp. 93-96.India, Andhra PradeshGeochronology - not specific to diamonds
DS1981-0380
1981
Singh, K.N.Singh, K.N.On the Studies of Lamprophyres from the Area between Damohini and Jamunia Nalas in Parts of Jharia Coalfield District Dhanbad, Bihar.Indian Minerals, Vol. 35, No. 2, APRIL-JUNE P. 41.India, BiharLamprophyres
DS201312-0521
2013
Singh, M.Kumar, M.R., Mishra, D.C., Singh, B., Venkat Raju, D.Ch., Singh, M.Geodynamics of NW