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SDLRC - Scientific Articles all years by Author - Sn-Ss


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 - Sn-Ss
Posted/
Published
AuthorTitleSourceRegionKeywords
DS1989-0581
1989
Snail, K.A.Hannssen, L.M., Carrington, W.A., Butler, J.E., Snail, K.A.Diamond synthesis using an oxygen acetylene torchMaterial Letters, Vol. 7, No. 7-8, Dec. pp. 289-292GlobalDiamond synthesis
DS201911-2564
2019
Snatish, M.Snatish, M., Tsunogae, T., Yang, C-X., Han, Y-S., Hari, K.R., Prasanth, M., Uthup, S.The Bastar craton, central India: a window to Archean-paleoproterozoic crustal evolution.Gondwana Research, in press available 69p. PdfIndiacraton

Abstract: The Bastar craton in central India, surrounded by cratonic blocks and Paleoproterozoic to Neoproterozoic orogenic belts, is a window to investigate the Archean-Paleoproterozoic crustal evolution and tectonic processes. Here we propose a new tectonic classification of the craton into the Western Bastar Craton (WBC), Eastern Bastar Craton (EBC), and the intervening Central Bastar Orogen (CBO). We present petrologic, geochemical and zircon U-Pb, REE and Lu-Hf data from a suite of rocks from the CBO and along the eastern margin of the WBC Including: (1) volcanic successions comprising meta-andesite and fine-grained amphibolite, representing arc-related volcanics along a convergent margin; (2) ferruginous sandstone, in association with rhyolite, representing a volcano-sedimentary succession, deposited in an active trench; and (3) metamorphosed mafic-ultramafic suite including gabbro, pyroxenite and dunite invaded by trondhjemite representing the section of sub-arc mantle and arc root adjacent to a long-lasting subduction system. Petrologic studies indicate that the mafic-ultramafic suite crystallized from an island arc tholeiitic parental magma in a suprasubduction zone environment. The chondrite-normalized and primitive mantle normalized diagrams of the mafic and ultramafic rocks suggest derivation from MORB magma. The mixed characters from N-MORB to E-MORB of the studied samples are consistent with subduction modification of a MORB related magma, involving partial melting of the metasomatized mantle wedge. Our zircon U-Pb age data suggest that the cratonic nuclei was constructed as early as Paleoarchean. We present evidence for active subduction and arc magmatism through Mesoarchean to Neoarchean and early Paleoproterozoic, with the trench remaining open until at least 2.3 Ga. Two major crust building events are recognized in the Bastar craton: during Mesoarchean (recycled Paleoarchean subduction-related as well as juvenile/depleted mantle components) and Neoarchean (accretion of juvenile oceanic crust, arc magmatism including granite batholiths and related porphyry mineralization). The final cratonization occurred during latest Paleoproterozoic, followed by collisional assembly of the craton and its incorporation within the Peninsular Indian mosaic during Mesoproterozoic. In the global supercontinent context, the craton preserves the history of Ur, the earliest supercontinent, followed by the Paleo-Mesoproterozoic Columbia, as well as minor thermal imprints of the Neoproterozoic Rodinia and associated Grenvillian orogeny.
DS1984-0684
1984
Snead, J.I.Snead, J.I., Mcculloh, R.P.Geologic Map of LouisianaLousiana Geological Survey, MAP 1: 500, 000GlobalGeology, Mid Continent
DS1989-1416
1989
Sneath, P.H.A.Sneath, P.H.A., Langham, C.D.OUTLIER: a BASIC program for detecting outlying members of multivariate clusters based on presence-absencedataComputers and Geosciences, Vol. 15, No. 6, pp. 939-964GlobalComputer, Program -OUTLIER.
DS1975-0776
1978
Snedden, T.Kay, S.M., Kay, R.W., Hangas, J., Snedden, T.Crustal Xenoliths from Potassic Lavas, Leucite Hills, WyominGeological Society of America (GSA), Vol. 10, No. 7, P. 432. (abstract.).United States, Wyoming, Rocky Mountains, Leucite HillsBlank
DS1981-0382
1981
Snedden, W.T.Snedden, W.T., Kay, S.Initial Stages of Kimberlite Eruption: Evidence from Mantle minerals in Ithaca Kimberlites.Geological Society of America (GSA), Vol. 13, P. 557. (abstract.).United States, Appalachia, New YorkGenesis, Mineral Chemistry
DS1981-0383
1981
Snedden, W.T.Snedden, W.T., Kay, S.Mineral Chemistry of Kimberlite and Included Xenocrysts Ithaca, New York.Geological Society of America (GSA), Vol. 13, No. 3, P. 178. (abstract.).United States, Appalachia, New YorkGeochemistry
DS1983-0348
1983
Snedden, W.T.Kay, S.M., Snedden, W.T., Foster, B.P., Kay, R.W.Upper Mantle Crustal Fragments in the Ithaca KimberlitesJournal of GEOLOGY, Vol. 91, No. 3, PP. 277-290.United States, Appalachia, New YorkNodules, Xenoliths, Petrography
DS1983-0586
1983
Snedden, W.T.Snedden, W.T.Mineralogy and Setting of the Ithaca KimberlitesMsc. Thesis, Cornell University, 91P. AND 72P. APPENDICES.United States, Appalachia, New YorkChemistry, Petrography, Regional Geology, Tectonics, Geophysics
DS1988-0649
1988
Sneddon, M.V.Sneddon, M.V., Hall, D.R.Polycrystalline diamond, manufacture, wear mechanism sand implications for bit designJournal of Petr. Technology, Vol. 40, No. 12, pp. 1593-1601GlobalDiamond Application, CVD.
DS1989-0589
1989
Snee, L.W.Harlan, S.S., Geissman, J.W., Snee, L.W., Schmidt, C.J.Paleomagnetism of Proterozoic mafic dikes, southwest Montana foreland, USANew Mexico Bureau of Mines Bulletin., Continental Magmatism Abstract Volume, Held, Bulletin. No. 131, p. 121 Abstract held June 25-July 1MontanaPaleomagnetics, Dike
DS1991-0667
1991
Snee, L.W.Harlan, S.S., Mehnert, H.H., Snee, L.W., Meen, J.K.Preliminary isotopic (K-Ar and 40Ar/38Ar) age determinations from selected Late Cretaceous and Tertiary igneous rocks in MontanaGuidebook of the Central Montana Alkalic Province, ed. Baker, D.W., Berg. R., No. 100, pp. 136. extended abstractMontanaGeochronology, Igneous rocks
DS1995-1985
1995
Snee, L.W.Verplanck, P.L., Farmer, G.L., Snee, L.W.Isotopic evidence on the origin of compositional layering in an epizonal magma bodyEarth and Planetary Science Letters, Vol. 136, No. 1-2, Nov. 1, pp. 31-42GlobalLayered intrusions, Geochronology
DS1996-0599
1996
Snee, L.W.Harlan, S.S., Geissman, J.W., Snee, L.W., Reynolds, R.L.Late Cretaceous remagnetization of Proterozoic mafic dikes southern Highland Mountains southwest Montana -Ar40 Ar39Geological Society of America (GSA) Bulletin., Vol. 108, No. 6, June pp. 653-668.MontanaGeochronology, Paleomagnetics -Highland Mountains
DS2003-0304
2003
Snee, L.W.Cunningham, D., Owen, L., Snee, L.W., Jiliang, L.Structural framework of a major transcontinental orogenic termination zone: the extremeJournal of the Geological Society of London, Vol. 160, 4, July pp. 575-590.ChinaTectonics - not specific to diamonds
DS200412-0392
2003
Snee, L.W.Cunningham, D., Owen, L., Snee, L.W., Jiliang, L.Structural framework of a major transcontinental orogenic termination zone: the extreme easternmost Tien Shan, China.Journal of the Geological Society, Vol. 160, 4, July pp. 575-590.ChinaTectonics - not specific to diamonds
DS201312-0008
2013
Snegirev, O.V.Afanasiev, V.P., Snegirev, O.V., Tychkov, N.S., Pokhilenko, N.P.Stability of kimberlite garnets exposed to chemical weathering: relationship with Cr contents.Doklady Earth Sciences, Vol. 448, 1, pp. 103-105.TechnologyGarnet mineralogy
DS2002-0375
2002
Sneider, R.Deschamps, F., Trampert, J., Sneider, R.Anomalies of temperature and iron in the uppermost mantle inferred from gravity dat a and tomographic...Physics of the Earth and Planetary Interiors, Vol.129, 3-4, pp.245-64.MantleGeophysics - gravity, Tomography - models
DS200412-0680
2004
Sneider, R.Godey, S., Deschamps, F., Trampert, J., Sneider, R.Thermal and compositional anomalies beneath the North American continent.Journal of Geophysical Research, Vol. 109, B1, 10.1029/2003 JB002263United States, CanadaGeothermometry
DS1992-1439
1992
Sneider, R.M.Sneider, R.M.The economic value of a synergistic organization. Paper quoted duringWoodall's address to SEG Denver MeetingPreprint, 9pAustraliaEconomics, Exploration philosophy
DS2002-0824
2002
Snell, C.S.Kendall, J.M., Sol, S., Thomson, C.J., White, D.J., Asudeh, I., Snell, C.S.Seismic heterogeneity and anisotropy in the western Superior Province, Canada:Geological Society of London Special Publication, No. 199, pp. 27-44.Northwest Territories, Ontario, Manitoba,SaskatchewanGeophysics - seismics
DS200912-0011
2009
Snelling, A.A.Armitage, M.H., Snelling, A.A.Radiohalos and diamonds Are diamond really for ever? Answers in genesis.Proceedsings of the Sixth International Conference on Creationism, Sept. 9, 20p.MantleJust for interest!
DS1960-0776
1967
Snelling, N.J.Allen, P.M., Snelling, N.J., Rex, D.C.Age Determinations from Sierra LeoneM.i.t. Annual Report 15th., NOS. 1381-1415.Sierra Leone, West AfricaGeochronology, Kimberlite
DS1984-0179
1984
Snelling, N.J.Cahen, L., Snelling, N.J., Delhal, J., Vail, J.R.The Geochronology and Evolution of AfricaOxford Clarendon Press, 512P.Africa, South Africa, West Africa, Central Africa, East AfricaKimberley, Tectonics, Structure, Regional Geology
DS1998-0866
1998
SnelsonLevander, A., Henstock, T.J., Snelson, Keller, GormanThe deep probe experiment: what is the role of inherited structure in thecontinents?Geological Society of America (GSA) Annual Meeting, abstract. only, p.A161.Northwest TerritoriesTectonics, Lithoprobe
DS1999-0356
1999
SnelsonKeller, G.R., Miller, Snelson, Sheehan, Levander, GrauchCrustal structure of the Rocky Mountain region, review and recent resultsGeological Society of America (GSA), Vol. 31, No. 7, p. 186. abstract.Alberta, WyomingTectonics
DS200512-0503
2005
SnelsonKeller, G.R., Karlstrom, K.E., Williams, M.L., Miller, K.C., Andronicos, C., Levander, A.R., Snelson, ProdehlThe dynamic nature of the continental crust-mantle boundary: crustal evolution in the southern Rocky Mountain region as an example.American Geophysical Union, Geophysical Monograph, No. 154, pp. 403-420.United States,Wyoming, Colorado PlateauTectonics
DS1997-1069
1997
Snelson, C.M.Snelson, C.M., Keller, G.R., et al.Western North American crustal structure: deep probe 1995Geological Society of America (GSA) Abstracts, Vol. 29, No. 2, March 20-21, p. 48.Alberta, Wyoming, MontanaTectonics, Crustal structure
DS1998-0575
1998
Snelson, C.M.Hanstock, T.J., Levander, A.R., Snelson, C.M., et al.The deep probe experiments: continent scale active source seismic profilingAmerican Geophysical Union (AGU) Annual Meeting, Vol 79, No. 17, p. 229. abstract.Alberta, Montana, Colorado PlateauGeophysics - seismics
DS1998-0865
1998
Snelson, C.M.Levander, A., Henstock, T.J., Snelson, C.M., KellerThe Deep Probe experiment; what is the role of inherited structure in the continents?Geological Society AmericanAnn.Meet., Vol. 30, No. 7, p. 161. abstract.Alberta, Western CanadaLithoprobe
DS1998-1364
1998
Snelson, C.M.Snelson, C.M., Henstock, T.J., Keller, Miller, LevanderCrustal and uppermost mantle structure along the Deep Probe seismic profileRocky Mountain Geol., Vol. 33, No. 2, pp. 181-98.Alberta, Western CanadaGeophysics - seismics, Lithoprobe
DS2003-0163
2003
Snelson, C.M.Brocher, T.M., Parsons, T., Trehu, A.M., Snelson, C.M., Fisher, M.A.Seismic evidence for Wide spread serpentinized forearc upper mantle along theGeology, Vol. 31, 3, pp. 267-70.California, Oregon, Washington, CascadiaGeophysics - seismics, Subduction
DS2003-0164
2003
Snelson, C.M.Brocher, T.M., Parsons, T., Trehu, A.M., Snelson, C.M., Fisher, M.A.Seismic evidence for Wide spread serpentinized forearc upper mantle along theGeology, Vol. 31, 3, pp. 267-70.California, OregonGeophysics - seismics
DS2003-0165
2003
Snelson, C.M.Brocher, T.M., Parsons, T., Trehu, A.M., Snelson, C.M., Fisher, M.A.Seismic evidence for Wide spread serpentinized forearc upper mantle along theGeology, Vol. 31, 3, March, pp. 267-270.California, Oregon, CascadesGeophysics - seismics, Subduction, slabs
DS2003-0166
2003
Snelson, C.M.Brocher, T.M., Parsons, T., Trehu, A.M., Snelson, C.M., Fisher, M.A.Seismic evidence for Wide spread serpentinized forearc upper mantle along theGeology, Vol. 31, 3, March pp. 267-70.California, United StatesGeophysics - seismics
DS200412-0212
2003
Snelson, C.M.Brocher, T.M., Parsons, T., Trehu, A.M., Snelson, C.M., Fisher, M.A.Seismic evidence for Wide spread serpentinized forearc upper mantle along the Cascadia margin.Geology, Vol. 31, 3, March pp. 267-70.United States, CaliforniaGeophysics - seismics
DS200512-1011
2005
Snelson, C.M.Snelson, C.M., Keller, G.R., Miller, K.C., Rumpel, H.M., Prodehl, C.Regional crustal structure derived from the CD-ROM 99 Seismic Refraction/Wide Angle Reflection Profile: the lower crust and upper mantle.American Geophysical Union, Geophysical Monograph, No. 154, pp. 271-292.United States,Wyoming, Colorado PlateauGeophysics - seismics, tectonics
DS201412-0855
2014
Snetkov, V.I.Snetkov, V.I., Talgamer, B.L.Appraisal and exploitation of mining and dressing waste at dredge sites. Journal of Mining Science, Vol. 50, 1, pp. 108-114.Russia, TransbaikaliaDiamond alluvials
DS201412-0856
2014
Snetkov, V.I.Snetkov, V.I., Talgamer, B.L.Appraisal and exploitation of mining and dressing waste at dredge sites. ( Mainly gold but diamonds as well).Journal of Mining Science, Vol. 50, 1, pp. 108-114.RussiaDredging
DS1991-0622
1991
Snieder, R.Gubbins, D., Snieder, R.Dispersion of P waves in subducted lithosphere: evidence for an eclogitelayerJournal of Geophysical Research, Vol. 96, No. B 4, April 10, pp. 6321-6335GlobalMantle, Eclogites
DS2000-0825
2000
Snieder, R.Rohm, A.H.E., Snieder, R., Goes, S., Trampert, J.Thermal structure of continental upper mantle inferred from S wave velocity and surface heat flow.Earth and Planetary Science Letters, Vol.181, No.3, Sept.15, pp.395-407.MantleGeothermometry, Geophysics - seismics
DS2001-0247
2001
Snieder, R.Deschamps, F., Snieder, R., Trampert, J.The relative density to shear velocity scaling in the uppermost mantlePhysical Earth and Planetary Interiors, Vol. 124, No. 3-4, Aug. pp. 193-212.MantleGeophysics - seismics, gravity
DS201504-0220
2015
SNL Metals & MiningSNL Metals & MiningWorld exploration trends 2015SNL Metals Economics Group, March 3, 11p.GlobalExploration - prices, budgets, arenas
DS201312-0853
2012
SNL Metals Economics GroupSNL Metals Economics Group23rd edition of corporate exploration strategies estimates worldwide total exploration budgets to surpass $ 21.5 billion in 2012.SNL Metals Economics Group, Dec. 6, 2p. SummaryGlobalEconomics
DS201312-0854
2013
SNL Metals Economics GroupSNL Metals Economics GroupGroup pipeline activity index Nov-Dec 2012. SNL Metals Economics Group, Feb. 5, 2p.GlobalFinancing
DS201312-0855
2013
SNL Metals Economics GroupSNL Metals Economics GroupWorldwide exploration trends 2013.PDAC 2013, 5p.GlobalEconomics
DS1994-1646
1994
Snoeyenbos, D.K.Snoeyenbos, D.K., Williams, M.I.An Archean eclogite facies terrane from the Snowbird tectonic zone, northern Saskatchewan.Eos, Vol. 75, No. 16, April 19, p. 355.SaskatchewanTectonics, Eclogite facies
DS1995-1785
1995
Snoeyenbos, D.R.Snoeyenbos, D.R., Williams, M.C., Hanmer, S.Archean high pressure metamorphism in the western Canadian ShieldEur. Journal of Mineralogy, Vol. 7, No. 6, Nov. 1, pp. 1251-1272Cordillera, British Columbia, Alberta, Yukonmetamorphism, Shield
DS201509-0434
2015
Snoeyenbos, D.R.Valley, J.W., Reinhard, D.A., Cavosie, A.J., Ushikubo, T., Lawrence, D.F., Larson, D.J., Kelly, T.F., Snoeyenbos, D.R., Strickland, A.Nano- and micro-geochronology in Hadean and Archean zircons by atom-probe tomography and SIMS: new tools for old minerals.American Mineralogist, Vol. 100, pp. 1355-1377.AustraliaGeochronology

Abstract: Atom-probe tomography (APT) and secondary ion mass spectrometry (SIMS) provide complementary in situ element and isotope data in minerals such as zircon. SIMS measures isotope ratios and trace elements from 1–20 ?m spots with excellent accuracy and precision. APT identifies mass/charge and three-dimensional position of individual atoms (±0.3 nm) in 100 nm-scale samples, volumes up to one million times smaller than SIMS. APT data provide unique information for understanding element and isotope distribution; crystallization and thermal history; and mechanisms of mineral reaction and exchange. This atomistic view enables evaluation of the fidelity of geochemical data for zircon because it provides new understanding of radiation damage, and can test for intracrystalline element mobility. Nano-geochronology is one application of APT in which Pb isotope ratios from sub-micrometer domains of zircon provide model ages of crystallization and identify later magmatic and metamorphic reheating.
DS1997-1070
1997
Snoke, A.W.Snoke, A.W., Tullis, J., Todd, V.R.Princeton atlas of fault related rocksPrinceton University of Press, $ 125.00 see date 1998 availabilityGlobalBook - ad, Atlas - Fault related rocks
DS1994-0826
1994
Snoke, J.A.James, D.E., Snoke, J.A.Structure and tectonics in the region of flat subduction beneath centralPeru: crust and uppermost mantleJournal of Geophy. Research, Vol. 99, No. B4, April 10, pp. 6899-6912PeruTectonics, Structure
DS1994-1647
1994
Snoke, J.A.Snoke, J.A., James, D.E.Structure of the continental lithosphere beneath southeast Brasil from surfacewave inversion: prel. results.International Symposium Upper Mantle, Aug. 14-19, 1994, pp. 121-123.BrazilTectonics, Lithosphere
DS200612-0766
2006
Snoke, J.A.Larson, A.M., Snoke, J.A., James, D.E.S-wave velocity structure, mantle xenoliths and the upper mantle beneath the Kaapvaal Craton.Geophysical Journal International, Vol. 167, 1, Oct., pp. 171-186.Africa, South AfricaGeophysics - seismics
DS2002-0103
2002
Snook, I.K.Barnard, A.S., Russo, S.P., Snook, I.K.Comparative Hartree-Fock and density functional theory study of cubic and hexagonal diamond.Philosophical Magazine B., Vol. 82, 17, pp. 1767-1776.GlobalDiamond - morphology
DS2003-0070
2003
Snook, I.K.Barnard, A.S., Russoa, S.P., Snook, I.K.Coexistence of bucky diamonds with nanodiamond and fullerene carbon phasesPhysical Review, Vol. 68, 7, 4p.GlobalDiamond - morphology
DS200412-0095
2003
Snook, I.K.Barnard, A.S., Russoa, S.P., Snook, I.K.Coexistence of bucky diamonds with nanodiamond and fullerene carbon phases.Physical Review Letters, Vol. 68, 7, 4p.TechnologyDiamond - morphology
DS1995-1014
1995
Snopkov, S.V.Kozhevnikov, N.O., Snopkov, S.V.Supermagnetism of traps and its relation to TEM anomaliesRussian Geology and Geophysics, Vol. 36, No. 5, pp. 89-100.Russia, YakutiaGeophysics -TEM., Deposit -Ivushka, Amakinskaya
DS1998-0158
1998
SnowBrandon, A.D., Walker, Morgan, Snow190 Pc 186 Os isotopic systematics of the upper mantle and some plumesMineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 227-8.MantleConvection, Chromitites, peridotites
DS201510-1811
2015
Snow, A.M.Vandenberg, J.A., Herrell, M., Faithful, J.W., Snow, A.M., Lacrampe, J., Bieber, C., Dayyani, S., Chisholm, V.Multiple modeling approach for the aquatic effects assessment of a proposed northern diamond mine development. Gahcho KueMine Water and the Environment, in press available, 19p.Canada, Northwest TerritoriesDeposit - Gahcho Kue

Abstract: Eight water models were used to assess potential aquatic environmental effects of the proposed Gahcho Kué diamond mine on groundwater and surface water flow and quality in the Northwest Territories, Canada. This sequence of models was required to cover different spatial and temporal domains, as well as specific physico-chemical processes that could not be simulated by a single model. Where their domains overlapped, the models were interlinked. Feedback mechanisms amongst models were addressed through iterative simulations of linked models. The models were used to test and refine mitigation plans, and in the development of aquatic component monitoring programs. Key findings generated by each model are presented here as testable hypotheses that can be evaluated after the mine is operational. This paper therefore offers a record of assumptions and predictions that can be used as a basis for post-validation.
DS201609-1754
2016
Snow, A.M.Vandenberg, J.A., Herrell, M., Faithful, J.W., Snow, A.M., Lacrampe, J., Bieber, C., Dayyani, S., Chisholm, V.Multiple modeling approach for the aquatic effects assessment of a proposed northern diamond mine development.Mine Water and the Environment, Vol. 35, pp. 350-368.Canada, Northwest TerritoriesDeposit - Gahcho Kue

Abstract: Eight water models were used to assess potential aquatic environmental effects of the proposed Gahcho Kué diamond mine on groundwater and surface water flow and quality in the Northwest Territories, Canada. This sequence of models was required to cover different spatial and temporal domains, as well as specific physico-chemical processes that could not be simulated by a single model. Where their domains overlapped, the models were interlinked. Feedback mechanisms amongst models were addressed through iterative simulations of linked models. The models were used to test and refine mitigation plans, and in the development of aquatic component monitoring programs. Key findings generated by each model are presented here as testable hypotheses that can be evaluated after the mine is operational. This paper therefore offers a record of assumptions and predictions that can be used as a basis for post-validation.
DS200612-1292
2006
Snow, C.A.Shragge, J., Snow, C.A.Bayesian geochemical discrimination of mafic volcanic rocks.American Journal of Science, Vol. 306, 3, pp. 191-209.TechnologyGeochemistry - not specific to diamonds
DS1981-0384
1981
Snow, D.Snow, D.Ashton Mining Venture Clamps Security on Kimberleys SiteThe National Times, JANUARY 18TH-24TH., P. 5.Australia, Western AustraliaArgyle, Description Of Site, Aborigine
DS2002-1517
2002
Snow, G.G.Snow, G.G., Juhas, A.P.Trends and forces in mining and mineral explorationSociety of Economic Geologists Special Publication, No.9,pp.1-16.GlobalEconomics - trends, evolutionary, consolidation, Statistics, charts, information, discoveries
DS1989-0183
1989
Snow, J.Brown, G., Bracewell, H., Snow, J.Gems of the Mud Tank carbonatiteThe Australian Gemologist, Vol. 17, No. 2, May pp. 52-59AustraliaCarbonatite, Mineralogy
DS1995-1786
1995
Snow, J.A.Snow, J.A.Legal aspects of due diligenceProspectors and Developers Association of Canada (PDAC) Short Course, March 4, pp. 7-40CanadaDue diligence, Legal -Ore reserves
DS1994-1648
1994
Snow, J.E.Snow, J.E., Hart, S.R., Dick, H.J.B.neodymium and Strontium isotope evidence linking mid-ocean ridge basalts and abyssal peridotitesNature, Vol. 371, Sept. 1, pp. 57-60GlobalPeridotites, Geochronology
DS1998-1365
1998
Snow, J.E.Snow, J.E., Schmidt, G.Constraints on Earth accretion deduced from noble metals in the oceanicmantleNature, Vol. 391, No. 6663, Jan. 8, pp. 166-168MantleAccretion, Noble metals, gold, PlatinuM.
DS2002-0701
2002
Snow, J.E.Hellebrand, E., Snow, J.E., Muhe, R.Mantle melting beneath Gakkel Ridge ( Arctic Ocean): abyssal peridotite spinel compositions.Chemical Geology, Vol.182, 2-4, Feb.15, pp.227-55.Arctic OceanPeridotites
DS201112-1009
2011
Snow, J.E.Stracke, A., Snow, J.E., Hellebrand, E., Von der Handt, A., Bourdon, B., Birbaum, K., Gunther, D.Abyssal peridotite Hf isotopes identify extreme mantle depletion.Earth and Planetary Science Letters, Vol. 308, 3-4, pp. 359-368.Mantle, Europe, GreenlandGeochronology
DS201112-1010
2011
Snow, J.E.Stracke, A., Snow, J.E., Hellebrand, E., Von der Handt, A., Bourdon, B., Birbaum, K., Guther, D.Abyssal peridotite Hf isotopes identify extreme mantle depletion.Earth and Planetary Science Letters, Vol. 308, 3-4, pp. 359-368.OceanGakkel Ridge
DS201701-0032
2016
Snow, J.E.Snow, J.E.Petit spots go big. Mantle enrichment processes.Nature Geoscience, Vol. 9, pp. 862-3.MantlePlume, hotspots

Abstract: Mantle enrichment processes were thought to be limited to parts of oceanic plates influenced by plumes and to continental interiors. Analyses of mantle fragments of the Pacific Plate suggest that such enrichment processes may operate everywhere.
DS1993-0799
1993
Snow, M.Kelmelis, J.A., Snow, M.Proceedings of the U.S. Geological Survey global change research forumUnited States Geological Survey (USGS) Circular, No. 1086, 121pUnited StatesBook -ad, Global change
DS1995-1787
1995
Snow, R.A.Snow, R.A.Directors and officers liabilitiesMining and the Environment: regulation and liability, 52pCanadaEconomics, Legal
DS1975-1001
1979
Snowden, D.V.Eales, E.V., Snowden, D.V.Chromiferous Spinels of the Elephant's Head DikeMineralium Deposita., Vol. 14, No. 2, PP. 227-242.Tanzania, East AfricaRelated Rocks
DS1981-0385
1981
Snowden, D.V.Snowden, D.V.Mineralogy and Petrology of Two Kimberlites at Dutoitspan Mine, kimberley.Msc. Thesis, Rhodes University, 134P.South AfricaMicroprobe, Analyses
DS1996-1336
1996
Snowden, D.V.Snowden, D.V.Practical interpretation of resource classification guidelinesAusIMM Conference Perth March 24-28, pp. 305-308AustraliaEconomics, Geostatistics, reserves, resources
DS2000-0341
2000
Snowden, D.V.Glacken, I.M., Snowden, D.V.Mineral resource estimationMin. Res. Ore Res. Est. AusIMM Guide, Mon. 23, pp. 189-98.AustraliaEconomics - geostatistics, ore reserves, exploration, Not specific to diamonds
DS2000-0906
2000
Snowden, D.V.Snowden, D.V.Practical interpretation of mineral resource and ore reserve classification guidelines.Min. Res. Ore Res. Est. AusIMM Guide, Mon. 23, pp. 643-52.AustraliaEconomics - geostatistics, ore reserves, exploration, Not specific to diamonds
DS1994-1649
1994
Snowden, V.Snowden, V.Improving predictions by studying realityGeostatistics for the Next Century, pp. 330-337GlobalGeostatistics, Reserve estimation
DS1992-1153
1992
Snowdon, L.R.Osadetz, K.G., Brooks, P.W., Snowdon, L.R.Oil families and their sources in Canadian Williston Basin (southeastern Saskatchewan and southwestern Manitoba)Canadian Petroleum Geologists Bulletin, Vol. 40, No. 3, September pp.254-273Saskatchewan, ManitobaWilliston Basin, Bakken Formation
DS1984-0685
1984
Snyatkova, O.L.Snyatkova, O.L., Pronyagin, N.I., et al.The carbonatite complex of the Khibiny massif and the discovery perspectives of economically important accumulations of natural soda.(Russian)Izves. Akad. Nauk SSSR (Russian), No. 11, pp.124-128RussiaCarbonatite
DS1998-0672
1998
SnyderJacob, D., Jagoutz, E., Zinngrebe, E., Snyder, TaylorComment and reply on the origins of Yakutian eclogite xenolithsJournal of Petrology, Vol. 39, No. 8, Aug. 1, pp. 1527-1539.Russia, YakutiaEclogites, Diamond genesis
DS1998-0728
1998
SnyderKeller, R., Taylor, L., Snyder, Sobolev, Carlson3- D petrography of a Diamondiferous eclogite from Udachnaya Siberia7th International Kimberlite Conference Abstract, pp. 405-7.Russia, SiberiaTomography, petrography, eclogite, Deposit - Udachnaya
DS1998-0729
1998
SnyderKeller, R.A., Remley, D., Snyder, Taylor, SobolevMantle xenoliths from the Obnazhennaya kimberlite, Yakutia7th International Kimberlite Conference Abstract, pp. 402-4.Russia, YakutiaXenoliths, Deposit - Obnazhennaya
DS1998-1375
1998
SnyderSobolev, V.N., Taylor, L.A., Snyder, Jerde, NealMetasomatism of the mantle beneath Yakutia: a quantitative study of secondary chemistry and mineral..7th International Kimberlite Conference Abstract, pp. 835-7.Russia, YakutiaXenoliths, Deposit - Udachnaya
DS1999-0617
1999
SnyderRuzicka, A., Riciputi, Taylor, Snyder, GreenwoodPetrogenesis of mantle derived sulphide inclusions in Yakutian diamonds: chemical and isotopic disequilibriuM.7th International Kimberlite Conference Nixon, Vol. 2, pp. 741-49.Russia, YakutiaQuenching from high temperatures, Deposit - Mir, 23rd., Aikhal, Udachnaya
DS2000-0908
2000
SnyderSobolev, N.V., Sobolev, V.N., Snyder, Yefimova, TaylorSignificance of eclogitic and related parageneses of natural diamonds #2Snyder, Neal, Ernst, Plan. Petrology and Geochemistry, pp. 15-26.GlobalDiamond - morphology, Diamond - genesis
DS2002-0143
2002
SnyderBerman, R., Pehrsson, S.J., Davis, W.J., Snyder, TellaA new model for ca 1.9 Ga tectonometamorphism in the western Churchill province: linked upper crustal thickGac/mac Annual Meeting, Saskatoon, Abstract Volume, P.9., p.9.SaskatchewanTectonic reconstructions
DS2002-0144
2002
SnyderBerman, R., Pehrsson, S.J., Davis, W.J., Snyder, TellaA new model for ca 1.9 Ga tectonometamorphism in the western Churchill province: linked upper crustal thickGac/mac Annual Meeting, Saskatoon, Abstract Volume, P.9., p.9.SaskatchewanTectonic reconstructions
DS2002-1456
2002
SnyderShearer, S., Bankey, Hill, Finn, Daniels, Snyder, RobertsUnited States aeromagnetic database: a companion to the North American magnetic anomaly map.Geological Society of America Annual Meeting Oct. 27-30, Abstract p. 387.United States, CanadaMap - magnetic
DS1995-1788
1995
Snyder, D.Snyder, D., Tait, S.Replenishment of magma chamber: comparison of fluid mechanic experiments with field relationsContributions to Mineralogy and Petrology, Vol. 122, No. 3, pp. 230-240MantleMagma, Genesis
DS1997-1071
1997
Snyder, D.Snyder, D., Crambes, C., Tait, S., Wiebe, R.A.Magma mingling in dikes and sillsJournal of Geology, Vol. 105, No. 1, Jan. pp. 75-86GlobalPetrology - experimental, Composite dikes
DS1998-1242
1998
Snyder, D.Roberts, B., Snyder, D.Upper crustal structures in the Slave Craton near Yellowknife - results from SNORCLE LINE 1.Yellowknife Geoscience Forum Nov. 25-27, p. 94-5. abstractNorthwest TerritoriesCraton, Tectonics
DS1999-0690
1999
Snyder, D.Snyder, D., Hobbs, R.The BIRPS Atlas II: a second decade of deep seismic reflection profilingGeological Society of London, CD-ROM approx. $ 165.00 United StatesEuropeCD-ROM data, Geophysics - seismics, Caledonia Orogen
DS2000-0455
2000
Snyder, D.Jones, A.G., Snyder, D., Asudeh, I., White, D., EatonLithospheric architecture at the Rae Hearne boundary revealed through magnetotelluric and seismic experimentGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000 Conference, 6p. abstract.Northwest Territories, Churchill, AlbertaGeophysics - seismics, magnetotellurics, Crustal - boundary
DS2001-0346
2001
Snyder, D.Fumagalli, P., Stixrude, L., Snyder, D.The 10 algorithm phase: a high pressure expandable sheet silicate stable during subduction of hydrated ...Earth and Planetary Science Letters, Vol. 186, No. 2, March 30, pp. 125-42.MantleSubduction, Lithosphere
DS2001-0547
2001
Snyder, D.Jones, A.G., Snyder, D., Ford, K.L., Spratt, J., EvansGeophysical experiments in central Baffin Island29th. Yellowknife Geoscience Forum, Nov. 21-23, abstract p. 38-9.Northwest Territories, Baffin IslandGeophysics, Trans Hudson Orogen
DS2002-0788
2002
Snyder, D.Jones, A.G., Snyder, D., Hanmer, S., Asudeh, I., White, D., Eaton, D., Clarke, G.Magnetotelluric and teleseismic study across the Snowbird Tectonics Zone of theGeophysical Research Letters, Vol. 29, 17, 10.1029/2002GL015359Manitoba, Saskatchewan, AlbertaGeophysics - MT, seismics
DS200512-1012
2005
Snyder, D.Snyder, D., Bellefleur, G.Feasibility study for using high resolution seismic methods to estimate kimberlite deposit volumes at Snap Lake diamond mine, Northwest Territories.Geological Survey of Canada, Current Research 2005-C3, 11p.Canada, Northwest TerritoriesGeophysics - crosshole seismology, vibrating, radar
DS200612-0187
2005
Snyder, D.Bruneton, M., Snyder, D.Probing the lithosphere of the Slave Craton through seismic surface wave analysis.32ndYellowknife Geoscience Forum, POSTERCanada, Northwest TerritoriesGeophysics - seismics
DS200612-1327
2005
Snyder, D.Snyder, D., et al.3-D model of the central Slave Craton.32ndYellowknife Geoscience Forum, p. 70 abstractCanada, Northwest TerritoriesTomography
DS200712-0066
2005
Snyder, D.Bellefleur, G., Matthews, L., Roberts,B., McMonnies, B., Salisbury, M., Snyder, D., Perron, G., McGaughty, J.Downhole seismic imaging of the Victor kimberlite, James Bay Lowlands, Ontario: a feasibility study.Geological Survey of Canada Current Research, 2005- C1, 7p.Canada, OntarioGeophysics - seismics
DS200712-1004
2006
Snyder, D.Snyder, D., Bruneton, M.The latest Slave mantle architecture and more on kimberlite trends.34th Yellowknife Geoscience Forum, p. 53. abstractCanada, Northwest TerritoriesGeophysics - seismics
DS200712-1005
2006
Snyder, D.Snyder, D., Bruneton, M.Mantle structure beneath the Wopmay margin of the Slave: Archean or Proterozoic?34th Yellowknife Geoscience Forum, p. 52. abstractCanada, Northwest TerritoriesGeophysics - seismics
DS201112-0772
2010
Snyder, D.Pawlak, A., Eaton, D.W., Bastow, I.D., Kendall, J-M., Helffrich, G., Wookey, J., Snyder, D.Crustal structure beneath Hudson Bay from ambient noise tomography: implications for basin formation.Geophysical Journal International, Vol. 184, 1, pp. 65-82.Canada, Ontario, Quebec, James Bay LowlandsGeophysics -
DS201312-0856
2013
Snyder, D.Snyder, D.Integrated 3-D models of the Slave & Rae cratons.GEM Diamond Workshop Feb. 21-22, Noted onlyCanada, Northwest Territories, AlbertaGeophysics - seismics
DS201312-0857
2013
Snyder, D.Snyder, D.Lithospheric structure and diamond potential of northern Canada.PDAC 2013, 27 ppt slidesCanada, Nunavut, Northwest TerritoriesTectonics
DS201312-0858
2013
Snyder, D.Snyder, D.Imaging Archean -age whole mineral systems.Precambrian Research, Vol. 229, pp. 125-132.Canada, Northwest TerritoriesSlave craton, metasomatism
DS201708-1767
2017
Snyder, D.Snyder, D.Construction and destruction of some North American cratons.11th. International Kimberlite Conference, OralUnited States, Canadacratons

Abstract: Construction histories of Archean cratons remain poorly understood; their destruction is even less clear because of its rarity, but metasomatic weakening is an essential precursor. By assembling geophysical and geochemical data in 3-D lithosphere models, a clearer understanding of the geometry of major structures within the Rae, Slave and Wyoming cratons of central North America is now possible. Little evidence exists of subducted slab-like geometries similar to modern oceanic lithosphere in these construction histories. Underthrusting and wedging of proto-continental lithosphere is inferred from multiple dipping discontinuities, emphasizing the role of lateral accretion. Archean continental building blocks may resemble the modern lithosphere of oceanic plateau, but they better match the sort of refractory crust expected to have formed at Archean ocean spreading centres. Radiometric dating of mantle xenoliths provides estimates of rock types and ages at depth beneath sparse kimberlite occurrences, and these ages can be correlated to surface rocks. The 3.6–2.6 Ga Rae, Slave and Wyoming cratons stabilized during a granitic bloom at 2.61–2.55 Ga. This stabilization probably represents the final differentiation of early crust into a relatively homogeneous, uniformly thin (35–42 km), tonalite-trondhjemite-granodiorite crust with pyroxenite layers near the Moho atop depleted lithospheric mantle. Peak thermo-tectonic events at 1.86–1.7 Ga broadly metasomatized, mineralized and recrystallized mantle and lower crustal rocks, apparently making mantle peridotite more ‘fertile’ and more conductive by introducing or concentrating sulfides or graphite at 80–120 km depths. This metasomatism may have also weakened the lithosphere or made it more susceptible to tectonic or chemical erosion. Late Cretaceous flattening of Farallon lithosphere that included the Shatsky Rise conjugate appears to have weakened, eroded and displaced the base of the Wyoming craton below 140–160 km. This process replaced the old re-fertilized continental mantle with relatively young depleted oceanic mantle.
DS1998-0875
1998
Snyder, D.B.Line, C.E.R., Hobbs, R.W., Snyder, D.B.Estimates of upper crustal heterogeneity in the Baltic Shield from seismic scattering and borehole logs.Tectonophysics, Vol. 286, No. 1-4, Mar. 10, pp. 171-184.Baltic Shield, Sweden, Norway, FinlandGeophysics - seismic
DS2001-1094
2001
Snyder, D.B.Snyder, D.B., Asudeh, I., Bostock, M.G., Lockhart, G.D.Ongoing teleseismic studies of the Slave Craton29th. Yellowknife Geoscience Forum, Nov. 21-23, abstract p. 78.Northwest Territories, Saskatchewan, AlbertaGeophysics - seismics
DS2001-1095
2001
Snyder, D.B.Snyder, D.B., Berman, R., Jones, A.G., Asudeh, I.Tectonic model for the unroofing of the northeastern Hearne domain based on geophysical petrological....29th. Yellowknife Geoscience Forum, Nov. 21-23, abstract p. 79.Northwest Territories, Saskatchewan, AlbertaTectonics
DS2002-1518
2002
Snyder, D.B.Snyder, D.B.Lithospheric growth at margins of cratonsTectonophysics, Vol. 355, 1-4, pp.7-22.MantleGeophysics - seismics, Subduction
DS2002-1519
2002
Snyder, D.B.Snyder, D.B., Bostock, M.G., Lockhart, G.D.Mantle layers in the Slave Craton30th. Yellowknife Geoscience Forum, Abstracts Of Talks And Posters, Nov. 20-22, p. 63. abstractNorthwest TerritoriesGeophysics - seismics, discontinuity
DS2003-1301
2003
Snyder, D.B.Snyder, D.B.Teleseismic investigations of the lithosphere beneath Central Baffin IslandGeological Survey of Canada Current Research, 2003-C14, 10p.NunavutGeophysics - seismics
DS2003-1302
2003
Snyder, D.B.Snyder, D.B., Bostock, M.G., Lockhart, G.D.Mapping the mantle lithosphere for diamond potential8 Ikc Www.venuewest.com/8ikc/program.htm, Session 9, AbstractMantleCraton studies - geophysics seismics, earthquakes, Review
DS2003-1303
2003
Snyder, D.B.Snyder, D.B., Bostock, M.G., Lockhart, G.D.Two anisotropic layers in the Slave CratonLithos, Vol. 71, 2-4, pp. 529-539.Northwest Territories, NunavutGeophysics - seismics
DS2003-1304
2003
Snyder, D.B.Snyder, D.B., Lockhart, G.D.Toward a mantle stratigraphy beneath the Central Slave Craton31st Yellowknife Geoscience Forum, p. 91. (abst.)Northwest TerritoriesGeophysics - seismics
DS200412-0357
2004
Snyder, D.B.Cook, F.A., Clowes, R.M., Snyder, D.B., Van der Velden, A.J., Hall, K.W., Erdmer, P., Evenchick, C.A.Precambrian crust beneath the Mesozoic northern Canadian Cordillera discovered by lithoprobe seismic reflection profiling.Tectonics, Vol. 23, 2, TC2012 10.1029/2003TC001412Canada, Northwest Territories, British Columbia, YukonGeophysics - seismics
DS200412-1864
2003
Snyder, D.B.Snyder, D.B.Teleseismic investigations of the lithosphere beneath Central Baffin Island.Geological Survey of Canada Current Research, 2003-C14, 10p.Canada, NunavutGeophysics - seismics
DS200412-1865
2003
Snyder, D.B.Snyder, D.B., Bostock, M.G., Lockhart, G.D.Mapping the mantle lithosphere for diamond potential.8 IKC Program, Session 9, AbstractMantleCraton studies - geophysics seismics, earthquakes Review
DS200412-1866
2003
Snyder, D.B.Snyder, D.B., Bostock, M.G., Lockhart, G.D.Two anisotropic layers in the Slave Craton.Lithos, Vol. 71, 2-4, pp. 529-539.Canada, NunavutGeophysics - seismics
DS200412-1867
2003
Snyder, D.B.Snyder, D.B., Lockhart, G.D.Toward a mantle stratigraphy beneath the Central Slave Craton.31st Yellowknife Geoscience Forum, p. 91. (abst.)Canada, Northwest TerritoriesGeophysics - seismics
DS200412-1868
2004
Snyder, D.B.Snyder, D.B., Rondenay, S., Bostock, M.G., Lockhart, G.D.Mapping the mantle lithosphere for diamond potential using teleseismic methods.Lithos, Vol. 77, 1-4, Sept. pp. 859-872.Canada, Northwest TerritoriesSlave Craton, exploration geophysics - seismics, imagin
DS200512-1013
2005
Snyder, D.B.Snyder, D.B.Seismic evidence for the growth of cratonic keels.GAC Annual Meeting Halifax May 15-19, Abstract 1p.Canada, Ontario, Northwest TerritoriesGeophysics - seismics, tectonics, Superior and Slave
DS200512-1014
2005
Snyder, D.B.Snyder, D.B., Lockhart, G.D.Kimberlite trends in NW Canada.Journal of the Geological Society, Vol. 162, 5, pp. 737-740.Canada, Northwest Territories, NunavutBrief overview
DS200512-1015
2004
Snyder, D.B.Snyder, D.B., Lockhart, G.D.Kimberlite trends at the surface and at depth.32nd Yellowknife Geoscience Forum, Nov. 16-18, p.72-73. (talk)Canada, Northwest TerritoriesGeophysics - seismics, SKS, Lac de Gras
DS200512-1016
2005
Snyder, D.B.Snyder, D.B., Lockhart, G.D.Kimberlite trends in NW Canada.Journal of the Geological Society, Vol. 162, 5, pp. 737-740.CanadaHistory
DS200612-1090
2006
Snyder, D.B.Pilkington, M., Snyder, D.B., Hemant, K.Weakly magnetic crust in the Canadian Cordillera.Earth and Planetary Science Letters, Vol. 248, 1-2, Aug. 15, pp. 461-470.Canada, British ColumbiaGeophysics - magnetics
DS200712-0909
2006
Snyder, D.B.Rondenay, S., Snyder, D.B., Chen, C.W., Straub, K.M., Bank, C.G., Bostock, M.G.Insight into the assembly and evolution of the Slave Craton from teleseismic dat a analyses.Geochimica et Cosmochimica Acta, In press availableCanada, Northwest TerritoriesGeophysics - seismics
DS200712-1006
2007
Snyder, D.B.Snyder, D.B.Stacked uppermost mantle layers within the Slave Craton of NW Canada as defined by anisotropic seismic discontinuities.Geological Association of Canada, Gac-Mac Yellowknife 2007, May 23-25, Volume 32, 1 pg. abstract p.76-77,Canada, Northwest TerritoriesGeophysics - seismics
DS200812-1086
2008
Snyder, D.B.Snyder, D.B.Mantle structures in the Slave and Rae Cratons inferred from seismic discontinuities.Northwest Territories Geoscience Office, p. 58. abstractCanada, Northwest TerritoriesBrief overview - cratons
DS200812-1087
2008
Snyder, D.B.Snyder, D.B.Stacked uppermost mantle layers within the Slave Craton of NW Canada as defined by anisotropic seismic discontinuities.Tectonics, Vol. 27, TC4006Canada, Northwest TerritoriesGeophysics - seismics
DS200812-1088
2008
Snyder, D.B.Snyder, D.B.Stacked uppermost mantle layers within the Slave Craton of NW Canada as defined by anisotropic seismic discontinuities.Tectonics, Vol. 27, 4, TC4006Canada, Northwest TerritoriesGeophysics - seismics
DS200812-1089
2008
Snyder, D.B.Snyder, D.B.New passive, teleseismological exploration tools to aid the diamond exploration industry.KEGS Shortcourse on Geophysics at PDAC March 1, 5p. plus 35 power pt. slidesTechnologyGeophysics - seismics
DS200912-0386
2009
Snyder, D.B.Kjarsgaard, B.A., Snyder, D.B.The GEM diamond project: an overview.37th. Annual Yellowknife Geoscience Forum, Abstracts p. 33-4.Canada, Northwest Territories, NunavutMantle lithosphere
DS200912-0577
2009
Snyder, D.B.Pedersen, H.A., Fishwick, S., Snyder, D.B.A comparison of cratonic roots through consistent analysis of seismic surface waves.Lithos, Vol. 109, 1-2, pp. 81-95.MantleGeophysics - seismics
DS200912-0705
2009
Snyder, D.B.Snyder, D.B., Kopylova, M.G.Seismically anisotropic subcontinental mantle lithosphere caused by metasomatic wehrlite pyroxenite dyke stockworks.GAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyCanada, Northwest TerritoriesLac de Gras field
DS201012-0066
2010
Snyder, D.B.Bostock, M.G., Eaton, D.W., Snyder, D.B.Teleseismic studies of the Canadian landmass: lithoprobe and its legacy.Canadian Journal of Earth Sciences, Vol. 47, 4, pp. 445-461.CanadaGeophysics - seismic
DS201012-0392
2010
Snyder, D.B.Kjarsgaard, B.A., Snyder, D.B.The GEM diamond project: an update of 2010 activities and a view forward to 2011.38th. Geoscience Forum Northwest Territories, Abstract p. 56.Canada, Northwest TerritoriesGEM database
DS201012-0731
2010
Snyder, D.B.Snyder, D.B., Grutter, H.S.Lithoprobes impact on the Canadian diamond exploration industry.Canadian Journal of Earth Sciences, Vol. 47, 5, pp. 783-800.CanadaGeophysics
DS201012-0732
2009
Snyder, D.B.Snyder, D.B., Lockhart, G.Does seismically anisotropic subcontinental mantle lithosphere require metasomatic wehrlite pyroxenite dyke stockworks?Lithos, Vol. 112 S pp. 961-965.Canada, Northwest TerritoriesSlave Craton
DS201012-0786
2010
Snyder, D.B.Thompson, D.A., Bastow, I.D., Helffich, G., Kendall, J.M., Wookey, J., Snyder, D.B., Eaton, D.W.Precambrian crustal evolution: seismic constraints from the Canadian Shield.Earth and Planetary Science Letters, Vol. 297, 3-4, pp. 655-666.CanadaGeophysics - seismics
DS201112-0066
2011
Snyder, D.B.Bastow, I.D., Thompson, D.A., Wookey, J., Kendall, J-M., Helffrich, G., Snyder, D.B., Eaton, D.W., Darbyshire, F.A.Precambrian plate tectonics: seismic evidence from northern Hudson Bay, Canada.Geology, Vol. 39, 1, pp. 91-94.Canada, Ontario, Quebec, Manitoba, Northwest TerritoriesGeophysics - seismics
DS201112-1039
2011
Snyder, D.B.Thompson, D.A., Helffich, G., Bastow, L.D., Kendall, J-M., Wookey, J., Eaton, D.W., Snyder, D.B.Implications of a simple mantle transition zone beneath cratonic North America.Earth and Planetary Science Letters, Vol. 312, pp. 28-36.Canada, United StatesCraton, convective flow
DS201212-0060
2012
Snyder, D.B.Bastow, I.D., Kendall, J.M., Brisbourne, A.M., Snyder, D.B., Thompson, D., Hawthorne, D., Hefffrich, G.R., Wookey, J., Horleston, A., Eaton, D.The Hudson Bay lithospheric experiment.Astronomy and Geophysics, pp. 6.21-6.24.Canada, Ontario, QuebecGeophysics - seismics
DS201212-0680
2012
Snyder, D.B.Snyder, D.B., Berman, R.G., Kendall, J.M., Sanborn-Barrie, M.Seismic anisotropy and mantle structure of the Rae craton, central Canada, from joint interpretation of SKS splitting and receiver functions.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractCanada, Saskatchewan, Northwest TerritoriesGeophysics - seismics
DS201312-0859
2013
Snyder, D.B.Snyder, D.B., Berman, R.G., Kendall, J-M., Sanborn-Barrie, M.Seismic anisotropy and mantle structure of the Rae craton, central Canada, from joint interpretation of SKS splitting and receiver functions.Precambrian Research, Vol. 232, pp. 189-208.Canada, Ontario, Hudson Bay, Baffin IslandMantle discontinuities
DS201312-0860
2013
Snyder, D.B.Snyder, D.B., Hillier, M., Kjarsgaard, B.A.3-D structural model of the Slave craton mantle lithosphere, Northwest Territories.Geoscience Forum 40 NWT, abstract only p. 47.Canada, Northwest TerritoriesTectonics
DS201312-0861
2013
Snyder, D.B.Snyder, D.B., Kjarsgaard, B.A.Mantle roots of major Precambrian shear zones inferred from structure of the Great Slave Lake shear zone, northwest Canada.Lithosphere, Vol. 5, 6, pp. 539-546.Canada, Northwest TerritoriesStructure - craton
DS201412-0857
2014
Snyder, D.B.Snyder, D.B.Lithospheric structure and diamond potential of northern Canada.2014 Yellowknife Geoscience Forum, p. 71, abstractCanada, Northwest TerritoriesGeophysics - seismic
DS201412-0858
2014
Snyder, D.B.Snyder, D.B., Hillier, M.J., Kjarsgaard, B.A., de Kemp, E.A., Craven, J.A.Lithospheric architecture of the Slave Craton, northwest Canada, as determined from an inter disciplinary 3-D model.Geochemistry, Geophysics, Geosystems: G3, Vol. 15, DOI: 10:1002/2013 GC005168Canada, Northwest TerritoriesTectonics
DS201412-0860
2013
Snyder, D.B.Snyder, D.B., Kjarsgaard, B.A.Mantle roots of major Precambrian shear zones inferred from structure of the Great Slave Lake shear zone.Lithosphere, Vol. 5, no. 6, pp. 539-546.Canada, Northwest TerritoriesGeophysics - seismics
DS201412-0878
2013
Snyder, D.B.Spratt, J.E., Skulski, T., Craven, J.A., Jones, A.G., Snyder, D.B., Kiyan, D.Magnetotelluric investigations of the lithosphere beneath the central Rae craton, maIn land Nunavut, Canada.Journal of Geophysical Research, Vol. 119, pp. 2415-2439.Canada, NunavutGeophysics - magnetotellurics
DS201503-0136
2015
Snyder, D.B.Bastow, I.D., Eaton, D.W., Kendall, J-M., Helffrich, G., Snyder, D.B., Thompson, D.A., Wookey, J., Darbyshire, F.A., Pawlak, A.E.The Hudson Bay lithospheric experiment ( HuBLE): insights into Precambrian plate tectonics and the development of mantle keels.Geological Society of London Special Publication: Continent formation through time., No. 389, pp. 41-67.Canada, Ontario, QuebecGeotectonics

Abstract: Hudson Bay Lithospheric Experiment (HuBLE) was designed to understand the processes that formed Laurentia and the Hudson Bay basin within it. Receiver function analysis shows that Archaean terranes display structurally simple, uniform thickness, felsic crust. Beneath the Palaeoproterozoic Trans-Hudson Orogen (THO), thicker, more complex crust is interpreted as evidence for a secular evolution in crustal formation from non-plate-tectonic in the Palaeoarchaean to fully developed plate tectonics by the Palaeoproterozoic. Corroborating this hypothesis, anisotropy studies reveal 1.8 Ga plate-scale THO-age fabrics. Seismic tomography shows that the Proterozoic mantle has lower wavespeeds than surrounding Archaean blocks; the Laurentian keel thus formed partly in post-Archaean times. A mantle transition zone study indicates ‘normal’ temperatures beneath the Laurentian keel, so any cold mantle down-welling associated with the regional free-air gravity anomaly is probably confined to the upper mantle. Focal mechanisms from earthquakes indicate that present-day crustal stresses are influenced by glacial rebound and pre-existing faults. Ambient-noise tomography reveals a low-velocity anomaly, coincident with a previously inferred zone of crustal stretching, eliminating eclogitization of lower crustal rocks as a basin formation mechanism. Hudson Bay is an ephemeral feature, caused principally by incomplete glacial rebound. Plate stretching is the primary mechanism responsible for the formation of the basin itself.
DS201601-0045
2015
Snyder, D.B.Snyder, D.B., Craven, J.A., Pilkington, M., Hillier, M.J.The three dimensional construction of the Rae craton, central Canada.Geochemistry, Geophysics, Geosystems: G3, Vol. 16, 10, pp. 3555-3574.Canada, Saskatchewan, AlbertaRae Craton

Abstract: Reconstruction of the 3-dimensional tectonic assembly of early continents, first as Archean cratons and then Proterozoic shields, remains poorly understood. In this paper, all readily available geophysical and geochemical data are assembled in a 3-D model with the most accurate bedrock geology in order to understand better the geometry of major structures within the Rae craton of central Canada. Analysis of geophysical observations of gravity and seismic wave speed variations revealed several lithospheric-scale discontinuities in physical properties. Where these discontinuities project upward to correlate with mapped upper crustal geological structures, the discontinuities can be interpreted as shear zones. Radiometric dating of xenoliths provides estimates of rock types and ages at depth beneath sparse kimberlite occurrences. These ages can also be correlated to surface rocks. The 3.6-2.6 Ga Rae craton comprises at least three smaller continental terranes, which "cratonized" during a granitic bloom. Cratonization probably represents final differentiation of early crust into a relatively homogeneous, uniformly thin (35-42 km), tonalite-trondhjemite-granodiorite crust with pyroxenite layers near the Moho. The peak thermotectonic event at 1.86-1.7 Ga was associated with the Hudsonian orogeny that assembled several cratons and lesser continental blocks into the Canadian Shield using a number of southeast-dipping megathrusts. This orogeny metasomatized, mineralized, and recrystallized mantle and lower crustal rocks, apparently making them more conductive by introducing or concentrating sulfides or graphite. Little evidence exists of thin slabs similar to modern oceanic lithosphere in this Precambrian construction history whereas underthrusting and wedging of continental lithosphere is inferred from multiple dipping discontinuities.
DS201701-0033
2017
Snyder, D.B.Snyder, D.B., Humphreys, E., Pearson, D.G.Construction and destruction of some North American cratons. Rae, Slave, WyomingTectonophysics, Vol. 694, pp. 464-486.United States, CanadaMetasomatism

Abstract: Construction histories of Archean cratons remain poorly understood; their destruction is even less clear because of its rarity, but metasomatic weakening is an essential precursor. By assembling geophysical and geochemical data in 3-D lithosphere models, a clearer understanding of the geometry of major structures within the Rae, Slave and Wyoming cratons of central North America is now possible. Little evidence exists of subducted slab-like geometries similar to modern oceanic lithosphere in these construction histories. Underthrusting and wedging of proto-continental lithosphere is inferred from multiple dipping discontinuities, emphasizing the role of lateral accretion. Archean continental building blocks may resemble the modern lithosphere of oceanic plateau, but they better match the sort of refractory crust expected to have formed at Archean ocean spreading centres. Radiometric dating of mantle xenoliths provides estimates of rock types and ages at depth beneath sparse kimberlite occurrences, and these ages can be correlated to surface rocks. The 3.6-2.6 Ga Rae, Slave and Wyoming cratons stabilized during a granitic bloom at 2.61-2.55 Ga. This stabilization probably represents the final differentiation of early crust into a relatively homogeneous, uniformly thin (35-42 km), tonalite-trondhjemite-granodiorite crust with pyroxenite layers near the Moho atop depleted lithospheric mantle. Peak thermo-tectonic events at 1.86-1.7 Ga broadly metasomatized, mineralized and recrystallized mantle and lower crustal rocks, apparently making mantle peridotite more ‘fertile’ and more conductive by introducing or concentrating sulfides or graphite at 80-120 km depths. This metasomatism may have also weakened the lithosphere or made it more susceptible to tectonic or chemical erosion. Late Cretaceous flattening of Farallon lithosphere that included the Shatsky Rise conjugate appears to have weakened, eroded and displaced the base of the Wyoming craton below 140-160 km. This process replaced the old re-fertilized continental mantle with relatively young depleted oceanic mantle.
DS201808-1751
2018
Snyder, D.B.Harris, G.A., Pearson, D.G., Liu, J., Hardman, M.F., Snyder, D.B., Kelsch, D.Mantle composition, age and geotherm beneath the Darby kimberlite field, west central Rae craton.Mineralogy and Petrology, doi.org/10.1007/s00710-018-0609-4 14p.Canada, Northwest Territoriesdeposit - Darby

Abstract: New geological and geophysical research on Canada’s Rae craton are providing an increasingly good baseline for diamond exploration. This study uses mantle xenoliths and xenocrysts from the Darby property, located ~200 km southwest of the community of Kugaaruk, Nunavut, to provide new information on the lithospheric mantle and diamond potential of the western portion of the central Rae. Peridotite xenoliths containing enough fresh olivine have a median Mg# value of 92.5, indistinguishable from the median value of 92.6 typical of cratonic peridotites world-wide. Only of the 14 peridotitic xenoliths contain fresh garnet. Of these, garnet in one sample is classified as harzburgitic (G10), giving a minimum pressure of 4.7 GPa using the P38 geobarometer (38 mW/m2 model geothermal gradient), while garnets from three peridotites are classified as lherzolitic (G9). 52 garnets picked from concentrate have lherzolitic affinities. Lherzolitic diopsides from kimberlite heavy mineral concentrate yield a lithospheric thickness of ~ 200 km. The four garnet peridotite xenoliths and 49 peridotitic garnets from concentrate yield two distinct modes in mantle sampling depths using Ni thermometry, when projected to the Cpx geotherm. A cluster of samples from the higher Ca/Cr lherzolitic garnets equilibrated at 765 to 920 °C with a group of peridotitic garnets (50 % of xenoliths and 28 % of concentrate) from the lower Ca/Cr lherzolitic garnets with anomalously high Ti concentrations yielding super-adiabatic TNi values The aluminum-in-olivine thermometer applied to olivines filtered to be “garnet facies yielded a mantle sampling portion of the mantle cargo from the diamond stability field. A suite of pyroxenitic xenoliths are a feature of each Darby kimberlite target. New screening techniques indicate that these rocks likely originate close to the crust mantle boundary. Osmium isotope analyses of the Darby peridotites reveal whole-rock Re-depletion ages ranging from Mesoarchean to Paleoproterozoic. The pyroxenite xenoliths have very radiogenic Os isotope compositions and provide the first age information from pyroxenites/“eclogites” beneath the Rae craton. Their resulting Archean whole rock TMA ages are consistent with a Mesoarchean age of the western Central Rae lithosphere older than the lithosphere beneath the Repulse Bay block in the East section of the Rae craton (Liu et al., 2016. Precambrian Research 272). The highly depleted olivine compositions, thick cold lithosphere, and Archean ages of the Darby peridotite xenoliths clearly indicate the presence of 200 km thick cold cratonic lithospheric mantle beneath the western segment of the central Rae craton circa 540 Ma. The Archean model ages of most of the pyroxenites support this, notwithstanding the fact that some of these rocks could be sampling either crust or mantle lithologies very close to the crust-mantle boundary. Mantle sampling took place well into the diamond stability field at Darby.
DS201809-2093
2018
Snyder, D.B.Snyder, D.B., Schetselaar, E., Pilkington, M., Schaeffer, A.J.Resolution and uncertainty in lithospheric 3-D geological models. Canada MohoMineralogy and Petrology, doi.org/10.1007/ s00710-018-0619-2. 15p.MantleGeophysics

Abstract: As three-dimensional (3-D) modelling of the subcontinental mantle lithosphere is increasingly performed with ever more data and better methods, the robustness of such models is increasingly questioned. Resolution thresholds and uncertainty within deep multidisciplinary 3-D models based on geophysical observations exist at a minimum of three levels. Seismic waves and potential field measurements have inherent limitations in resolution related to their dominant wavelengths. Formal uncertainties can be assigned to grid-search type forward or inverse models of observable parameter sets. Both of these uncertainties are typically minor when compared to resolution limitations related to the density and shape of a specific observation array used in seismological or potential field surveys. Seismic wave source distribution additionally applies in seismology. A fourth, more complex level of uncertainty relates to joint inversions of multiple data sets. Using independent seismic wave phases or combining diverse methods provides another measure of uncertainty of particular physical properties. Extremely sparse xenolith suites provide the only direct correlation of rock type with observed or modelled physical properties at depths greater than a few kilometers. Here we present one case study of the Canadian Mohorovi?i? (Moho) discontinuity using only two data sets. Refracted and converted seismic waves form the primary determinations of the Moho depth, gravity field modeling provide a secondary constraint on lateral variations, the slope of the Moho, between the sparse seismic estimates. Although statistically marginal, the resulting co-kriged Moho surface correlates better with surface geology and is thus deemed superior.
DS202107-1134
2021
Snyder, D.B.Snyder, D.B., Savard, G., Kjarssgaard, B.A., Vaillancourt, A., Thurston, P.C., Ayer, J.A., Roots, E.Multidisciplinary modeiling of mantle lithosphere structure within the Superior craton, North America.Geochemistry, Geophysics, Geosytems, 20p. PdfCanada, United Statesgeophysics - seismics

Abstract: Structure within the Earth is best studied in three dimensions and using several coincident overlays of diverse information with which one can best see where unusual properties match up. Here we use regional surfaces causing discontinuities in seismic waves a few hundred kilometers deep in the Earth, intersected and thus calibrated by rebuilt rock columns using rare rock samples erupted to the surface in two locations. Electrically conductive regions can be mapped using natural (magnetotelluric) currents. East- and west-dipping seismic discontinuity surfaces match surface structures that developed about 1.8 billion years ago marginal to the Superior crustal block. Surfaces dipping to the southeast and northwest match some boundaries between crustal blocks that are over 2.5 billion years old, but many such crustal boundaries trend more east-west. Conductive rocks appear more commonly above these discontinuity surfaces where gas-rich fluids apparently flowed and that the discontinuities somehow filtered these fluids. The mismatch in orientation and dip between the most ancient deep and exposed structures suggests that plate tectonic processes operating today differed earlier than 2.5 billion years ago.
DS1960-0600
1965
Snyder, F.G.Snyder, F.G., Gerdeman, P.E.Explosive Igneous Activity Along an Illinois Missouri Kansas Axis.American Journal of Science, Vol. 263, PP. 465-493.Appalachia, United States, Illinois, Missouri, Kansas, Central StatesMid-continent, Structure, Tectonics
DS1960-1028
1968
Snyder, F.G.Snyder, F.G.Tectonic History of Mid-continental United StatesUniversity MISSOURI Bulletin., No. 1, PP. 65-77.GlobalMid-continent
DS1970-0192
1970
Snyder, F.G.Snyder, F.G.Structural Lineaments and Mineral Deposits, Eastern United SAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME), PP. 76-94.GlobalMid-continent
DS1998-1444
1998
Snyder, G.Taylor, L.A., Bulanova, G., Snyder, G., Keller, R.Multiple inclusions in diamonds: evidence for complex petrogenesis7th International Kimberlite Conference Abstract, pp. 883-5.Russia, Siberia, YakutiaDiamond morphology, chemistry, inclusions, Deposit - Mir
DS1999-0535
1999
Snyder, G.Patel, S.C., Frost, C.D., Chamberlain, K.R., Snyder, G.Proterozoic metamorphism and uplift history of the north central LaramieMountains, Wyoming.Journal of Metamorphic Geology, Vol. 17, pp. 243-58.WyomingMetamorphic terranes, Geothermometry, geochronology
DS1992-1440
1992
Snyder, G.A.Snyder, G.A., et al.neodymium and Strontium isotopes from Diamondiferous eclogites, Yakutia, Siberia: evidence for an old depleted mantle protolith.Eos, Transactions, Annual Fall Meeting Abstracts, Vol. 73, No. 43, October 27, abstracts p. 656.Russia, SiberiaMantle, Geochronology
DS1993-0462
1993
Snyder, G.A.Fraracci, K.N., Taylor, L.A., Jerde, E.A., Snyder, G.A., ClaytonTwo unusual Diamondiferous eclogite xenoliths from the Mir kimberlite inYakutia, SiberiaGeological Society of America Annual Abstract Volume, Vol. 25, No. 6, p. A445 abstract onlyRussia, Siberia, YakutiaXenoliths -eclogite, Deposit -Mir
DS1993-1493
1993
Snyder, G.A.Snyder, G.A., Jerde, E.A., Taylor, L.A., Halliday, A.N., Sobolevneodymium and Strontium isotopes from Diamondiferous eclogites, UdachnayaEarth and Planetary Science Letters, Vol. 118, No. 1-4, July, pp. 91-100.Russia, Siberia, YakutiaGeochronology, Deposit -Udachnaya
DS1993-1494
1993
Snyder, G.A.Snyder, G.A., Jerde, E.A., Taylor, L.A., Sobolev, N.V.Earliest differentiation of the earth's mantle: evidence from the isotopic studies of Diamondiferous eclogites, Yakutia, Siberia, Russia.Geological Society of America Annual Abstract Volume, Vol. 25, No. 6, p. A73 abstract onlyRussia, Yakutia, RussiaGeochronology, Eclogites
DS1993-1495
1993
Snyder, G.A.Snyder, G.A., Taylor, L.A., Jerde, E.A., et al.Petrogenesis of garnet pyroxenite and spinel peridotite xenoliths of the Tell Danun alkali basalt volcano.International Geology Review, Vol. 35, No. 12, Dec. pp. 1104-1120.SyriaXenoliths, Harrat As Shamah area
DS1994-1348
1994
Snyder, G.A.Pearson, D.G., Snyder, G.A., Shirley, S.B., Taylor, L.A.Rhenium- Osmium (Re-Os) isotope evidence for a mid-Archean age of Diamondiferous eclogite xenoliths -Udachnaya.Mineralogical Magazine, Vol. 58A, pp. 705-706. AbstractRussia, YakutiaGeochronology, Deposit -Udachnaya
DS1994-1658
1994
Snyder, G.A.Sobolev, V.N., Taylor, L.A., Snyder, G.A., Sobolev, N.V.Diamondiferous eclogites from the Udachnaya kimberlite pipe, YakutiaInternational Geology Review, Vol. 36, No. 1, Jan. pp. 42-64.Russia, YakutiaEclogites, Deposit -Udachnaya
DS1995-0123
1995
Snyder, G.A.Beard, B.L., Snyder, G.A., Taylor, L.A., Fraracci, et al.Eclogites from the Mir kimberlite, Russia: evidence of an Archean ophioliteprotolith.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 41-43.Russia, Yakutia, Malo-BotubaEclogites, Deposit -Mir
DS1995-0124
1995
Snyder, G.A.Beard, B.L., Taylor, L.A., Snyder, G.A.Compositional similarities between eclogites from different geologicsettings: Archean and Phanerozoic.Geological Society of America (GSA) abstract, Vol. 27, No. 2, March p. 36.GlobalEclogites
DS1995-1462
1995
Snyder, G.A.Pearson, D.G., Snyder, G.A., Shirey, S.B., Taylor, L.A.Archean Rhenium- Osmium (Re-Os) age for Siberian eclogites and constraints on Archeantectonics.Nature, Vol. 374, No. 6524, April 20, pp. 711-713.Russia, Siberia, RussiaGeochronology, Eclogites
DS1995-1789
1995
Snyder, G.A.Snyder, G.A.Petrology and chemistry of an Early Proterozoic lherzolite -anorthosite pluton of the White Sea complexInternational Geology Review, Vol. 37, No. 6, June, pp. 547-562Europe, KareliaPetrology, Lherzolite
DS1995-1790
1995
Snyder, G.A.Snyder, G.A., Taylor, L.A., Beard, B.L., Sobolev, N.V.Siberian eclogite xenoliths: keys to differentiation of the Archeanmantle.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 549-551.Russia, YakutiaEclogite xenoliths, Deposit -Udachnaya. Mir
DS1995-1791
1995
Snyder, G.A.Snyder, G.A., Taylor, L.A., Jerde, E.A., Clayton, MayedaArchean mantle heterogeneity and origin of Diamondiferous eclogites:evidence hydroxyl in garnets.American Mineralogist, Vol. 80, July-Aug. No. 7-8, pp. 799-809.GlobalGeochronology, Eclogites
DS1995-1797
1995
Snyder, G.A.Sobolev, V.N., Taylor, L.A., Snyder, G.A., Sobolev, N.V.Diamondiferous eclogites from the Siberian Platform: samples with peridotitic signature? #2Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 552-554.Russia, SiberiaEclogites, Peridotites
DS1995-1799
1995
Snyder, G.A.Sobolev, V.N., Taylore, L.A., Snyder, G.A., PokhilenkoA unique metasomatised peridotite xenolith from the Mir kimberlite, Siberian PlatformProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 555-557.Russia, SiberiaXenolith -peridotite, Deposit -Mir
DS1995-1877
1995
Snyder, G.A.Taylor, L.A., Snyder, G.A.Diamondiferous eclogite xenoliths from kimberlites: a mantle or crustalorigin?Geological Society of America (GSA) abstract, Vol. 27, No. 2, March p. 91.South Africa, Russia, YakutiaEclogites, Mantle, crust
DS1996-1337
1996
Snyder, G.A.Snyder, G.A., Taylor, L.A.Diamond genesis in Archean Yakutian eclogites, SiberiaGeological Society of America, Abstracts, Vol. 28, No. 7, p. A-290.Russia, SiberiaEclogites, Diamond genesis
DS1996-1403
1996
Snyder, G.A.Taylor, L.A., Snyder, G.A., Sobolev, N.V.Eclogitic inclusions in diamonds: evidence of complex mantle processes overtime.Earth and Planetary Science Letters, Vol. 142, No. 3/4, Aug. 1, pp. 535-552.RussiaEcologites, Diamond inclusions
DS1996-1404
1996
Snyder, G.A.Taylor, L.A., Valley, J.W., Clayton, R.N., Snyder, G.A.Oxygen isotopes by laser-heating and conventional techniques a study of Siberian Diamondiferous eclogitesInternational Geological Congress 30th Session Beijing, Abstracts, Vol. 1, p. 106.Russia, SiberiaGeochronology, Eclogites
DS1997-1072
1997
Snyder, G.A.Snyder, G.A., Taylor, L.A., Sobolev, N.V.The origins of Yakutian eclogite xenolithsJournal of Petrology, Vol. 38, No. 1, Jan. 1, pp. 85-114.Russia, YakutiaEclogite, Xenolith
DS1998-1366
1998
Snyder, G.A.Snyder, G.A., Keller, R.A., Taylor, L.A., Remley, D.The origin of ultramafic (Group A) eclogites: neodymium and Strontium isotopic evidence from the Obnazhennaya kimberlite.7th International Kimberlite Conference Abstract, pp. 823-5.Russia, YakutiaEclogite xenoliths, Deposit - Obnazhennaya
DS1998-1367
1998
Snyder, G.A.Snyder, G.A., Taylor, L.A., Beard, B.L., HallidayThe diamond bearing Mir eclogites, neodymium and Strontium isotopic evidence for continental crustal input Archean Oceanic7th International Kimberlite Conference Abstract, pp. 826-8.Russia, YakutiaEclogites, Deposit - Mir
DS1998-1371
1998
Snyder, G.A.Sobolev, N.V., Snyder, G.A., et al.Extreme chemical diversity in the mantle during eclogitic diamondformation: evidence from inclusions..International Geology Review, Vol. 40, No. 7, pp. 567-578.Russia, YakutiaDiamond inclusions, mineral chemistry, Deposit - Mir
DS1999-0570
1999
Snyder, G.A.Promprated, P., Taylor, L. A., Snyder, G.A.Petrochemistry of the mantle beneath Thailand: evidence from peridotitexenoliths.International Geology Review, Vol. 41, No. 6, June pp. 506-30.GlobalPeridotite, Xenoliths - not specific to diamonds
DS1999-0691
1999
Snyder, G.A.Snyder, 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
DS2000-0949
2000
Snyder, G.A.Taylor, L.A., Keller, R.A., Snyder, G.A., Wang, W., et al.Diamonds and their mineral inclusions and that they tell us: detailed pullapart a Diamondiferous eclogiteInternational Geology Review, Vol. 42, No. 11, Nov. pp. 959-83.Russia, YakutiaDiamond - morphology, eclogite, Mineral chemistry, cathodluminescence
DS2003-1365
2003
Snyder, G.A.Taylor, L.A., Snyder, G.A., Keller, R., Remley, D.A., Anand. M., Wiesli, R.Petrogenesis of Group A eclogites and websterites: evidence from the ObnazhennayaContributions Mineralogy and Petrology, Vol.Russia, YakutiaPetrology, genesis, Deposit - Obnazhennaya
DS200412-1974
2003
Snyder, G.A.Taylor, L.A., Snyder, G.A., Keller, R., Remley, D.A., Anand,M., Wiesli, R., Valley, J., Sobolev, N.V.Petrogenesis of Group A eclogites and websterites: evidence from the Obnazhennaya kimberlite, Yakutia.Contributions to Mineralogy and Petrology, Vol. 145, pp. 424-443.Russia, YakutiaPetrology, genesis Deposit - Obnazhennaya
DS1989-1417
1989
Snyder, G.L.Snyder, G.L., Hall, R.P., Hughes, D.J., Ludwig, K.R.Mafic intrusives in Precambrian rocks of the Wyoming Province and BeltBasinNew Mexico Bureau of Mines Bulletin., Continental Magmatism Abstract Volume, Held, Bulletin. No. 131, p. 249. AbstractWyomingUltramafic
DS1990-1385
1990
Snyder, G.L.Snyder, G.L.Early Precambrian basic rocks of the USAHall, R.P., Hughes, D.K., editors, Early Precambrian Basic, pp. 191-220Minnesota, Wisconsin, WyomingBasic/ultrabasic, Precambrian
DS1993-0232
1993
Snyder, G.L.Chamberlain, K.R., Patel, S.C., Frost, B.R., Snyder, G.L.Thick skinned deformation of the Archean Wyoming province during Proterozoic arc-continent collision.Geology, Vol. 21, No. 11, November pp. 995-998.Colorado, WyomingTectonics, Deformation -Cheyenne boundary
DS2002-1664
2002
Snyder, K.Vicenzi, E.P., Heaney, P.J., Snyder, K.Radiation halos, a rare microstructure in diamonds from the Central African RepublicEos, American Geophysical Union, Spring Abstract Volume, Vol.83,19, 1p.Central African RepublicDiamond - morphology, carbonado
DS1992-1441
1992
Snyder, M.T.Snyder, M.T.Exploration equipment. the drive for mining efficiency includesexplorationEngineering and Mining Journal, Vol. 193, No. 7, July pp. 38-41GlobalMining equipment, Exploration uses
DS1994-1650
1994
Snyder, M.T.Snyder, M.T.Exploration, exploitation, the processes between and beyond... overview of Mining industry's goalEngineering and Mining Journal, Vol. 195, No. 1, January pp.WW 30-32United States, CanadaEconomics, Exploration activities
DS1991-1093
1991
Snyder, S.L.McCarten, L., Snyder, S.L., Stover, C.W.Map showing the relationship to selected mafic and ultramafic bodies in the crust of the eastern United States to seismically active areasUnited States Geological Survey (USGS) Map, No. MF-2143, 1, 2, 500, 000 $ 3.50AppalachiaMafic, ultramafics, Seismics
DS1997-0159
1997
Snyder, S.L.Cannon, W.F., Daniels, D.L., Snyder, S.L.New aeromagnetic map of the Midcontinent rift in northwestern Wisconsin and adjacent Minnesota.Geological Society of America (GSA) Abstracts, Vol. 29, No. 4, Apr. p. 9.Wisconsin, MinnesotaGeophysics - aeromagnetics, Tectonics
DS2002-0348
2002
Snyder, S.L.Daniels, D.L., Snyder, S.L.Wisconsin aeromagnetic and gravity maps and data: a web site for distribution of dataU.s. Geological Survey, OF 02-0230 58p. http://pubs.usgs.gov/of/2002/of02-498WisconsinBlank
DS200412-0402
2002
Snyder, S.L.Daniels, D.L., Snyder, S.L.Wisconsin aeromagnetic and gravity maps and data: a web site for distribution of data.U.S. Geological Survey, OF 02-0230 58p.United States, WisconsinMap - geophysics
DS1995-1798
1995
Snyderm G.A.Sobolev, V.N., Taylor, L.A., Snyderm G.A.Diamondiferous eclogites and peridotites: are there petrogeneticrelationships?Geological Society of America (GSA) abstract, Vol. 27, No. 2, March p. 88.RussiaEclogites, Deposit -Mir
DS1995-1878
1995
Snyer, G.A.Taylor, L.A., Snyer, G.A., Sobolev, V.N.Trace element chemistry of eclogitic inclusions in diamond and comparisons with host eclogite, Mir.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 625-627.Russia, YakutiaGeochemistry -eclogite, Deposit -Mir
DS1970-0994
1974
Snyman, C.P.Snyman, C.P.Possible Classification Parameters of South Africa Kimberlites.Geological Society of South Africa Transactions, Vol. 77, No. 2, PP. 85-91.South AfricaKimberlite Genesis
DS1993-1009
1993
Snyman, C.P.McNerney, N., Dippenaar, K., Snyman, C.P., Begg, E.J.B.The geology of the Greenview lamprophyric breccia ventSouth African Journal of Geology, Vol. 95, No. 5-6, pp. 194-202South AfricaBreccia, Alkaline rocks
DS1998-1368
1998
Snyman, J.E.W.Snyman, J.E.W.Gemstones... precious stones of interest ( not diamonds)South Africa Council, Handbook # 16, pp. 282-293.South AfricaEconomic - history, areas, Gemstones
DS200712-0592
2007
Snyman, L.W.Lamprecht, G.H., Human, H.G.C., Snyman, L.W.Detection of diamond in ore using pulsed laser Raman spectroscopy.International Journal of Mineral processing, Vol. 84, 1-4, October, pp. 262-273.TechnologySorting, laser excitation
DS200912-0424
2009
Snyman, L.W.Lamprecht, G.H., Human, H.G.C., Snyman, L.W.Diamond detection in ore using laser Raman spectrosopy: comparison between pulsed and continuous wave lasers as excitation source at 532 nm.Transactions of the Institution of Mining and Metallurgy, Vol. 118, 1, March pp. 60-62.TechnologyDiamond processing
DS200412-1962
2004
Snyman, M.Taplin, R., Snyman, M.Doing business in South Africa's new mining environment: a legal perspective.Canadian Institute of Mining and Metallurgy Bulletin, Vol. 97, 1078, March pp. 91-98.Africa, South AfricaLegal - royalty
DS201503-0177
2015
So, B-D.So, B-D., Yuen, D.A.Generation of tectonic over-pressure inside subducting oceanic lithosphere involving phase-loop of olivine-wadsleyite transition.Earth and Planetary Science Letters, Vol. 413, March 1, pp. 59-69.MantleSubduction
DS201112-0916
2011
So, H.Satish-Kumar, M., So, H., Yoshino, T., Kato, M., Hiroi, Y.Experimental determination of carbon isotope fractionation between iron carbide melt and carbon: 12 C-enriched carbon in the Earth's core?Earth and Planetary Science Letters, Vol. 310, 3-4, pp. 340-348.MantleCarbon
DS200512-0659
2005
So, J.F.Lu, P.J., Yao, N., So, J.F., Harlow, G.E., Lu, J.F., Wang, G.F., Chaikin, P.M.The earliest use of corundum and diamond in prehistoric China.Archeometry, Vol. 47,1, Feb. pp. 1-12. Blackwell PublicationsChinaHistory
DS1992-1442
1992
Soares, A.Soares, A.Geostatistical estimation of multi-phase structuresMathematical Geology, Vol. 24, No. 2, February pp. 149-160GlobalGeostatistics, Structure
DS1995-1481
1995
Soares, P.C.Perdoncini, L.C., Soares, P.C., Bizzi, L.A.Diamonds associated with the Permo-Carboniferous glacial deposits in the Parana Basin, Brasil.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 436-438.Brazil, Parana, Paraguay, Uruguay, ArgentinaGeomorphology, Alluvials
DS1998-1369
1998
Soares, P.C.Soares, P.C., Rostirolla, Reis NetoPre-Gondwana continental fragments: amalgamation and mineralization in southeastern South America.Journal of African Earth Sciences, Vol. 27, 1A, p. 187. AbstractSouth AmericaTectonics
DS200712-1007
2007
Soares, P.C.Soares, P.C., Riffel, S.B.Hypsemtric curves as a tool for paleosurface mapping.Mathematical Geology, Vol. 38, 6, pp. 679-695.TechnologyPaleosurfaces - geomorphology not specific to diamonds
DS201112-0777
2010
Soares, P.C.Perdoncini, L.C., Soares, P.C., Roberto de Gois, J.Excursao de acmpo: Geologia e ocxorencias diamantiferas da regiao de Tibagi.5th Brasilian Symposium on Diamond Geology, Nov. 6-12, Guidebook pp. 92-101.South America, Brazil, ParanaGuidebook area - Tibagi
DS201808-1789
2018
Soares de Oliveira, F.V.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.
DS201712-2716
2017
Soares Franca, O.Pereira, R.S., Fuck, R.A., Soares Franca, O., Leite, A.A.Evidence of young, proximal and primary (YPP) diamond source occurring in alluviums in the Santa Antonio do Bonito, Santo Inacio and Douradhinho rivers in Coromandel region, Minas Gerais.Brazilian Journal of Geology, Vol. 47, 3, pp. 383-401.South America, Brazildeposit - Alta Paranaiba

Abstract: Magmatism associated with the Alto Paranaíba structural high comprises kimberlites, kamafugites, and alkaline complexes, forming an approximately 400 x 150 km NW-SE belt in the southern São Francisco Craton. Dating of some intrusions reveals ages between 120 and 75 Ma. Chemical analyses of garnet recovered in alluvium from traditional diamond digging areas indicate peridotitic garnet windows in Três Ranchos and Coromandel. Six hundred and eighty (680) diamonds acquired or recovered during mineral exploration in the digging areas of Romaria, Estrela do Sul, Três Ranchos and Coromandel show unique characteristics, certain populations indicating young, proximal and primary sources (YPP). Analyses of 201 stones from Santo Antônio do Bonito, Santo Inácio and Douradinho rivers alluvium, Coromandel, present no evidence of transport, characterizing a proximal source. Within these river basins, exposures of the Late Cretaceous Capacete Formation basal conglomerate contain mainly small rounded and/or angular quartzite pebbles and of basic and ultrabasic rocks, as well as kimberlite minerals (garnet, ilmenite, spinel, sometimes diamond). A magnetotelluric profile between the Paraná and Sanfranciscana basins shows that the thick underlying lithosphere in the Coromandel region coincides with the peridotitic garnet window and with a diamond population displaying proximal source characteristics. Diamond-bearing kimberlite intrusions occur in different areas of Alto Paranaíba.
DS201112-0981
2010
Soares Lima, E.Soares Lima, E., Landim Dominguez, J.M.Analise de minerais pesados como ferramenta na avaliacao de possiveis depositos diamantiferos na platforma continental no sul da Bahia.5th Brasilian Symposium on Diamond Geology, Nov. 6-12, abstract p. 62.South America, Brazil, BahiaPlacer diamonds
DS201012-0144
2010
Soares RochaDe Oliveira Cordeiro, P.F., Brod, J.A., Ventura Santos, R., Dantas, E.L., Gouvieia de Oliveira, C., Soares Rocha, Barbosa, E.Stable ( C,O) and radiogenic (Sr, Nd) isotopes of carbonates as indicators of magmatic and post magmatic processes of phoscorite series rocks and carbonatites fContributions to Mineralogy and Petrology, In press available, 14p.South America, BrazilCatalao I
DS201112-0256
2011
Soares Rocha BarbosaDe Oliveira Cordeiro, Brod, Palmieri, Gouveia de Oliveira, Soares Rocha Barbosa, Santos, Gaspar, AssisThe Catalao I niobium deposit, central Brazil: resources, geology and pyrochlore chemistry.Ore Geology Reviews, Vol. 41, pp. 112-121.South America, BrazilCarbonatite
DS201212-0681
2012
Soares Rocha Barbosa, E.Soares Rocha Barbosa, E., Brod, J.A., Junqueira-Brod, T.C., Dantas, E.L., De Oliveira Cordeiro, P.F., Siqueira Gomide, C.Bebdourite from its type area Sailtre 1 complex: a key petrogenetic series in the Late-Cretaceous Alto Paranaiba kamafugite carbonatite phoscorite association, central Brazil.Lithos, Vol. 146-147, pp. 56-72.South America, BrazilCarbonatite
DS201112-0257
2011
Soares Rochas Barbosa, E.De Oliveire Cordeiro, P.F., Brod, J.A., Ventura Santos, R., Dantas, E.L., Gouveia de Oliveira, C., Soares Rochas Barbosa, E.Stable (C,O) and radiogenic (Sr,Nd) isotopes of carbonates as indicators of magmatic and post-magmatic processes of phoscorite series rocks and carbonatites from Catalao 1, central Brazil.Contributions to Mineralogy and Petrology, Vol. 161, 3, pp. 451-464.South America, BrazilCarbonatite
DS1987-0644
1987
Sobachenko, V.N.Samoilov, V.S., Ronenson, B.M., Sobachenko, V.N.Geochemistry of alkaline palingenesis and the associatedcarbonatiteformation.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 196, No. 4, pp. 976-980RussiaBlank
DS1989-1331
1989
Sobachenko, V.N.Samoylov, V.S., Ronenson, B.M., Sobachenko, V.N.Geochemistry of alkalic palingenesis and the carbonatite formation associated with itDoklady Academy of Science USSR, Earth Science Section, Vol. 296, No. 1-6, pp. 207-210RussiaCarbonatite, Ilmen-Vishnevorogorsk belt
DS1994-1651
1994
Sobachenko, V.N.Sobachenko, V.N., Gundobin, A.G., Sandimirova, G.P., et al.Strontium isotopes in the rocks of formational type of near fault alkaline carbonate silicate metasomatites.Russian Geology and Geophysics, Vol. 35, No. 3, pp. 51-58.Russia, Urals, YeniseiGeochronology, Carbonatite
DS1975-0864
1978
Sobba raju, M.Setti, D.N., Srennivasa rao, T., Sobba raju, M.A Note on the Occurrence of Kimberlite -carbonatite Enclaves in the Peninsular Gneiss Warangal District, A.p.Indian Minerals, Vol. 32, No. 2, PP. 59-61.India, Andhra PradeshAlluvial Placer Deposits, Genesis
DS1900-0081
1901
Sobbe, F.A.Von.Sobbe, F.A.Von.Mining and Treatment of Diamond Bearing Ground in South Africa.Liverpool Eng. Soc. Transactions, Vol. 22, PP. 103-119.Africa, South AfricaMining Engineering, Diamond Recovery
DS1986-0761
1986
Sobczak, L.W.Sobczak, L.W., Mayr, U., Sweeney, J.F.Crustal section across the polar continent, ocean transition in CanadaCanadian Journal of Earth Sciences, Vol. 23, pp. 608-21.Northwest Territories, Boothia Peninsula, Ellesmere IslandGeodynamics
DS1989-1418
1989
Sobczak, L.W.Sobczak, L.W., Halpenny, J.F., Thomas, M.D.An enhanced residual isostatic anomaly map of Canada: a new perspective for crustal investigationsGeological Society of Canada (GSC) Forum 1989, P. 22 abstractGlobalMidcontinent, Seismics
DS201603-0425
2015
Sobel, E.R.Terra Acosta, V., Bande, A., Sobel, E.R., Parra, M., Schildgen, T.F., Stuart, F., Strecker, M.R. .Cenozoic extension in the Kenya Rift from low temperature thermochronology: links to diachronous spaciotemporal evolution of rifting in East Africa.Tectonics, Vol. 34, 12, pp. 2367-2388.Africa, KenyaRifting

Abstract: The cooling history of rift shoulders and the subsidence history of rift basins are cornerstones for reconstructing the morphotectonic evolution of extensional geodynamic provinces, assessing their role in paleoenvironmental changes and evaluating the resource potential of their basin fills. Our apatite fission track and zircon (U-Th)/He data from the Samburu Hills and the Elgeyo Escarpment in the northern and central sectors of the Kenya Rift indicate a broadly consistent thermal evolution of both regions. Results of thermal modeling support a three-phased thermal history since the early Paleocene. The first phase (~65 50?Ma) was characterized by rapid cooling of the rift shoulders and may be coeval with faulting and sedimentation in the Anza Rift basin, now located in the subsurface of the Turkana depression and areas to the east in northern Kenya. In the second phase, very slow cooling or slight reheating occurred between ~45 and 15?Ma as a result of either stable surface conditions, very slow exhumation, or subsidence. The third phase comprised renewed rapid cooling starting at ~15?Ma. This final cooling represents the most recent stage of rifting, which followed widespread flood-phonolite emplacement and has shaped the present-day landscape through rift shoulder uplift, faulting, basin filling, protracted volcanism, and erosion. When compared with thermochronologic and geologic data from other sectors of the East African Rift System, extension appears to be diachronous, spatially disparate, and partly overlapping, likely driven by interactions between mantle-driven processes and crustal heterogeneities, rather than the previously suggested north south migrating influence of a mantle plume.
DS201811-2595
2018
Sobh, M.Ngalamo, J.F.G., Sobh, M., Bisso, D., Abdelsalam, M.G., Atekwana, E., Ekodeck, G.E.Lithospheric structure beneath the Central Africa Orogenic Belt in Cameroon from the analysis of satellite gravity and passive seismic data.Tectonophysics, Vol. 745, pp. 326-337.Africa, Cameroongeophysics - seismic

Abstract: We present original results that contribute to the understanding of lithospheric structures modification of regions that have witnessed superimposition of multiple tectonic events throughout their geological history. We analyze satellite gravity data through two-dimensional radially-averaged power spectral analysis as well as passive seismic data through thermal modeling to image the depth to the Moho and the lithosphere - asthenosphere boundary (LAB beneath the Central Africa Orogenic Belt (CAOB). The CAOB is an ENE-trending deformation belt extending from Cameroon in the west to Sudan in the east. In Cameroon, it is found on the northern edge of the Congo craton represented by the Oubanguides orogenic belt (the Western Cameroon, the Adamawa - Yade, and the Yaoundé domains). It coincides with the Adamawa plateau and the Benue Trough, and it is spotted by the Cenozoic Cameroon Volcanic Line (CVL). The CAOB was formed during the Precambrian Greater Gondwana assembly but was reactivated during the Mesozoic as a result of Gondwana breakup. We find deeper Moho and LAB) beneath Congo craton and the Yaoundé domain reaching ~50?km and ~200?km, respectively. We map shallower Moho and LAB beneath the CAOB (together with the Adamawa plateau and the Benue trough) reaching ~25?km and ~70?km, respectively. We interpret the shallower LAB beneath the CAOB as due to zonal sub-continental lithospheric mantle (SCLM) delamination along the northern edge of the Congo craton that occurred in association with collisional assembly of Greater Gondwana. This allowed for channelization of mantle flow during the Cenozoic resulting in the formation of the CVL and the uplift of the Adamawa plateau. Our approach can be used to understand the modification of lithospheric structures beneath other terrains that have long tectonic history.
DS201812-2812
2018
Sobh, M.Goussi Ngalamo, J.F., Sobh, M., Bisso, D., Abdelsalam, M.G., Atekwana, E., Ekodeck, G.E.Lithospheric structure beneath the central Africa orogenic belt in Cameroon from the analysis of satellite gravity and passive seismic data.Tectonophysics, Vol. 745, pp. 326-337.Africa, Cameroongeophysics - seismics

Abstract: We present original results that contribute to the understanding of lithospheric structures modification of regions that have witnessed superimposition of multiple tectonic events throughout their geological history. We analyze satellite gravity data through two-dimensional radially-averaged power spectral analysis as well as passive seismic data through thermal modeling to image the depth to the Moho and the lithosphere - asthenosphere boundary (LAB beneath the Central Africa Orogenic Belt (CAOB). The CAOB is an ENE-trending deformation belt extending from Cameroon in the west to Sudan in the east. In Cameroon, it is found on the northern edge of the Congo craton represented by the Oubanguides orogenic belt (the Western Cameroon, the Adamawa - Yade, and the Yaoundé domains). It coincides with the Adamawa plateau and the Benue Trough, and it is spotted by the Cenozoic Cameroon Volcanic Line (CVL). The CAOB was formed during the Precambrian Greater Gondwana assembly but was reactivated during the Mesozoic as a result of Gondwana breakup. We find deeper Moho and LAB) beneath Congo craton and the Yaoundé domain reaching ~50?km and ~200?km, respectively. We map shallower Moho and LAB beneath the CAOB (together with the Adamawa plateau and the Benue trough) reaching ~25?km and ~70?km, respectively. We interpret the shallower LAB beneath the CAOB as due to zonal sub-continental lithospheric mantle (SCLM) delamination along the northern edge of the Congo craton that occurred in association with collisional assembly of Greater Gondwana. This allowed for channelization of mantle flow during the Cenozoic resulting in the formation of the CVL and the uplift of the Adamawa plateau. Our approach can be used to understand the modification of lithospheric structures beneath other terrains that have long tectonic history.
DS200412-1707
2004
Sobie, P.Russell, H.A.J., McClenaghan, M.B., Boucher, D., Sobie, P.Kimberlite indicator minerals distribution in eskers, Lake Timiskaming kimberlite field, Ontario and Quebec: preliminary resultsGeological Association of Canada Abstract Volume, May 12-14, SS14-03 p. 262.abstractCanada, Ontario, Lake TemiskamingGeochemistry, geomorphology
DS201212-0682
2012
Sobie, P.Sobie, P.Overview of Firestone diamonds's activities in Botswana and Lesotho.PDAC 2012, abstractAfrica, Botswana, LesothoDeposits
DS201808-1782
2018
Sobie, P.Rapopo, M., Sobie, P.The Liqhobong kimberlite cluster: an update on the geology.Mineralogy and Petrology, doi.org/10.1007/s00710-018-0624-5 12p.Africa, Lesothodeposit - Liqhobong

Abstract: The Cretaceous Liqhobong kimberlite cluster comprises at least six known diamondiferous Group 1 kimberlite bodies; namely the circular Main Pipe (8.5 ha), ovoid Satellite Pipe (1.6 ha), Discovery Blow (0.15 ha), Blow (0.1 ha), the Main Dike adjoining the blows and pipes, and one other recently exposed dike. The kimberlites intrude Jurassic Drakensberg lavas and outcrop at ~2650 masl in rugged Maluti Mountain terrain, and are emplaced along a strike of about 2.5km. The cluster represents at least three episodes of structurally controlled kimberlite intrusion; the first which comprised the dike(s?) and the two blows (the blows being dike enlargements emplaced 1km apart) and later the two separate emplacements of the Main and Satellite Pipes.
DS1998-0257
1998
Sobie, P.A.Clarke, J., Sobie, P.A., Wilkes, T.A., Zweistra, P.The geology and economic evaluations of the Liqhobong kimberlites, Lesotho.7th International Kimberlite Conference Abstract, pp. 158-160.LesothoPetrology, Deposit - Liqhobong
DS2003-0906
2003
Sobie, P.A.McClenaghan, M.B., Kjarsgaard, I.M., Kjarsgaard, B.A., Sobie, P.A.Application of surficial exploration methods in the Lake Timiskaming kimberlite field8 Ikc Www.venuewest.com/8ikc/program.htm, Session 8, POSTER abstractOntarioGeochemistry, geomorphology
DS200412-1263
2003
Sobie, P.A.McClenaghan, M.B., Kjarsgaard, I.M., Kjarsgaard, B.A., Sobie, P.A.Application of surficial exploration methods in the Lake Timiskaming kimberlite field, Canada.8 IKC Program, Session 8, POSTER abstractCanada, OntarioDiamond exploration Geochemistry, geomorphology
DS200512-1017
2005
Sobie, P.A.Sobie, P.A., Long, G.The mini bulk sampling of kimberlite 92-2 by Contact Diamond Company.CIM Mining Rocks April 24-27th. Toronto Annual Meeting, Paper# 1874 AbstractCanada, Ontario, Kirkland LakeNews item - Contact Diamond
DS201911-2565
2019
Soboelev, N.V.Soboelev, N.V., Logvinova, A.M., Tomilenko, A.A., Wirth, R., Bulbak, T.A., Lukyanova, L.I., Fedorova, E.N., Reutsky, V.N., Efimova, E.S.Mineral and fluid inclusions in diamonds from the Urals placers, Russia: evidence for solid molecular N2 and hydrocarbons in fluid inclusions.Geochimica et Cosmochimica Acta, Vol. 266, pp. 197-212.Russia, Uralsdiamond inclusions

Abstract: The compositions of mineral inclusions from a representative collection (more than 140 samples) of diamonds from the placer deposits in the Ural Mountains were studied to examine their compositional diversity. The overwhelming majority of rounded octahedral and dodecahedral stones typical of placers contain eclogitic (E-type) mineral inclusions (up to 80%) represented by garnets with Mg# 40-75 and Ca# 10-56, including the unique high calcic “grospydite” composition, omphacitic pyroxenes containing up to 65% of jadeite, as well as kyanite, coesite, sulfides, and rutile. Peridotitic (P-type) inclusions are represented by olivine, subcalcic Cr-pyrope, chrome diopside, enstatite and magnesiochromite that are typical for diamonds worldwide. Comparing the chemical composition of olivine, pyrope and magnesiochromite in diamonds of the Urals, north-east of the Siberian platform placers and Arkhangelsk province kimberlites show striking similarity. There are significant differences only in the variations of carbon isotopic composition of the diamonds from the placers of the Urals and north-east of the Siberian platform. One typical rounded dodecahedral diamond was found to contain abundant primary oriented submicrometer-sized (<3.0?µm) octahedral fluid inclusions identified by transmission electron microscopy, which caused the milky color of the entire diamond crystal. The electron energy-loss spectrum of a singular inclusion has a peak at ?405?eV, indicating that nitrogen is present. The Raman spectra with peaks at 2346-2350?cm?1 confirmed that nitrogen exists in the solid state at room temperature. This means that fossilized pressure inside fluid inclusions may be over 6.0 GPa at room temperature, so the diamond may be considered sublithospheric in origin. However, identification of unique fluid inclusions in one typical placer diamond allows one to expand the pressure limit to at least more than 8.0 GPa. The volatile components of four diamonds from the Urals placers were analyzed by gas chromatography-mass spectrometry (GC-MS). They are represented (rel. %) by hydrocarbons and their derivatives (14.8-78.4), nitrogen and nitrogenated compounds (6.2-81.7), water (2.5-5.5), carbon dioxide (2.8-12.1), and sulfonated compounds (0.01-0.96). It is shown that high-molecular-weight hydrocarbons and their derivatives, including chlorinated, nitrogenated and sulfonated compounds, appear to be stable under upper mantle P-T conditions. A conclusion is drawn that Urals placer diamonds are of kimberlitic origin and are comparable in their high E-type/P-type inclusion ratios to those from the northeastern Siberian platform and in part to diamonds of the Arkhangelsk kimberlite province.
DS1993-1493
1993
SobolevSnyder, G.A., Jerde, E.A., Taylor, L.A., Halliday, A.N., Sobolevneodymium and Strontium isotopes from Diamondiferous eclogites, UdachnayaEarth and Planetary Science Letters, Vol. 118, No. 1-4, July, pp. 91-100.Russia, Siberia, YakutiaGeochronology, Deposit -Udachnaya
DS1995-0541
1995
SobolevFinnie, K., Fisher, D., Griffin, W.L., Harris, J., SobolevNitrogen aggregation in metamorphic diamonds from KazakhstanGeochimica et Cosmochimica Acta, Vol. 58, No.23, pp. 5173-5177.Russia, KazakhstanMetamorphic rocks, microdiamonds, Kokchetav massif
DS1995-0683
1995
SobolevGriffin, W.L., Kaminsky, F., O'Reilly, S.Y., Ryan, SobolevMapping the Siberian lithosphere with garnets and spinelsProceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 194-5.Russia, SiberiaGeothermometry, Deposit -Daldyn, Alakit, Malo Botuobiya
DS1996-0269
1996
SobolevChepurov, A.I., Tomilenko, A.A., Shebanin, A.P., SobolevFluid inclusions in diamonds from Yakutian placersDoklady Academy of Sciences, Vol. 339, No. 8, Jan., pp. 128-132.Russia, YakutiaDiamond inclusions, Alluvials
DS1997-1162
1997
SobolevTomilenko, A.A., Chepurov, Turkin, Shebanin, SobolevFluid inclusions in synthetic diamond crystalsDoklady Academy of Sciences, Vol. 353, No. 2, Feb-Mar, pp. 247-50.GlobalDiamond - synthetics, crystallography
DS1998-0220
1998
SobolevCartigny, P., De Corte, Shatsky, Sobolev, JavoyMicrodiamonds from ultra high pressure (UHP) metamorphic rocks of the Kokchetav massif and bearing on carbon and nitrogen ...Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 276-7.RussiaSubduction, Deposit - Kokchetav
DS1998-0318
1998
SobolevDe Corte, K., Cartigny, P., Shatsky, De Paepe, SobolevMicrodiamonds from ultra high pressure (UHP) metamorphic rocks of Kokchetav Massif, northernKazakstan: FTIR spectroscopy....7th International Kimberlite Conference Abstract, pp. 184-186.Russia, KazakhstanMetamorphic rocks, diamond morphology, Deposit - Kokchetav
DS1998-0319
1998
SobolevDe Corte, K., Cartigny, P., Shatsky, Sobolev, JavoyEvidence of fluid inclusions in metamorphic microdiamonds from the Kokchetav Massif.Geochimica et Cosmochimica Acta, Vol. 62, No. 23/24, Dec. pp. 3765-73.Russia, KazakhstanMicrodiamonds, nitrogen, Deposit - Kokchetav Massif
DS1998-0728
1998
SobolevKeller, R., Taylor, L., Snyder, Sobolev, Carlson3- D petrography of a Diamondiferous eclogite from Udachnaya Siberia7th International Kimberlite Conference Abstract, pp. 405-7.Russia, SiberiaTomography, petrography, eclogite, Deposit - Udachnaya
DS1998-0729
1998
SobolevKeller, R.A., Remley, D., Snyder, Taylor, SobolevMantle xenoliths from the Obnazhennaya kimberlite, Yakutia7th International Kimberlite Conference Abstract, pp. 402-4.Russia, YakutiaXenoliths, Deposit - Obnazhennaya
DS1998-1228
1998
SobolevReimers, L.F., Pokhilenko, Yefimova, SobolevUltramafic mantle assemblages from Sytykanskaya kimberlite pipe, Yakutia7th. Kimberlite Conference abstract, pp. 730-32.Russia, YakutiaXenoliths, mineral chemistry, Deposit - Sytykanskaya
DS1998-1624
1998
SobolevZedgenizov, D.A., Logvinova, Shatskii, SobolevInclusions in microdiamonds from some kimberlite diatremes of YakutiaDoklady Academy of Sciences, Vol. 359, No. 2, pp. 204-8.Russia, YakutiaDiamond inclusions, Microdiamonds
DS1999-0691
1999
SobolevSnyder, 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
DS2000-0101
2000
SobolevBorzdov, Y.M., Sokol, Palyanov, Khokhryakov, SobolevGrowth of synthetic diamond monocrystals weighing up to six carats and perspectives of their application.Doklady Academy of Sciences, Vol. 374, No. 7, Sept-Oct. pp. 1113-5.RussiaDiamond - morphology, Diamond - synthesis, Crystallography
DS2001-0934
2001
SobolevPokhilenko, N.P., McDonald, Hall, SobolevAbnormally thick Cambrian lithosphere of the southeast Slave Craton evidence from crystalline inclusions ..Slave-Kaapvaal Workshop, Sept. Ottawa, 3p. abstractNorthwest TerritoriesDiamonds and pyrope compositions - kimberlites, Deposit - Snap Lake
DS2001-0935
2001
SobolevPokhilenko, N.P., Sobolev, McDonald, Hall, YefimovaCrystalline inclusions in diamonds from kimberlites of the Snap lake area: new evidence anomalous lithosphereDoklady Academy of Sciences, Vol. 381, No. 7, Sept/Oct. pp. 806-11.Northwest TerritoriesDiamond - inclusions, Deposit - Snap Lake
DS200512-0007
2004
SobolevAgashev, A.M., Pokhilenko, N.P., Tolstov, A.V., Polyanichko, Malkovets, SobolevNew age dat a on kimberlites from the Yakutian Diamondiferous Province.Doklady Earth Sciences, Vol. 399, 8, pp.1142-1145.Russia, YakutiaGeochronology
DS200612-0047
2006
SobolevAshchepkov, I.V., Vladykin, Sobolev, Pokhilenko, Rotman, Logvinova, Afanasiev, Pokhilenko, KarpenkoReconstruction of the mantle sequences and the structure of the feeding and vein magmatic systems beneath the kimberlite fields of Siberian platform.Vladykin: VI International Workshop, held Mirny, Deep seated magmatism, its sources and plumes, pp. 79-103.Russia, SiberiaDyke systems
DS200612-0048
2006
SobolevAshchepkov, I.V., Vladykin, Sobolev, Pokhilenko, Rotman, Logvinova, Afanasiev, Pokhilenko, KarpenkoVariations of the oxygen conditions in mantle column beneath Siberian kimberlite pipes and it's application to lithospheric structure of feeding systems.Vladykin: VI International Workshop, held Mirny, Deep seated magmatism, its sources and plumes, pp. 125-144.Russia, SiberiaRedox
DS200912-0447
2009
SobolevLiu, Y., Taylor, L.A., Sarbadhikari, Valley, Ushikubo, Spicuzza, Kita, Ketchum, Carlson, Shatsky, SobolevMetasomatic origin of diamonds in the world's largest Diamondiferous eclogite.Lithos, In press - available 41p.RussiaDeposit - Udachnaya
DS201012-0394
2009
SobolevKlein-BenDavid, O., Logvinova, A.M., Schrauder, M., Spetius, Z.V., Weiss, Hauri, Kaminsky, Sobolev, Navon, O.High Mg carbonatitic Micro inclusions in some Yakutian diamonds - a new type of diamond forming fluid.Lithos, Vol. 112 S pp. 648-659.RussiaMineral chemistry - end member
DS201112-0640
2011
SobolevMalkovets, V.G., Zedgenizov, Sobolev, Kuzmin, Gibsher, Shchukina, Golovin, Verichev, PokhilenkoContents of trace elements in olivines from diamonds and peridotite xenoliths of the V.Grib kimberlite pipe ( Arkhangel'sk Diamondiferous province, Russia).Doklady Earth Sciences, Vol. 436, 2, pp. 301-307.RussiaDeposit - Grib
DS1992-1443
1992
Sobolev, A.Sobolev, A., Casey, J.E., Shimizu, N., Perfit, M.Contamination and mixing of Mid Ocean Ridge Basalt (MORB) primary melts: evidence from melt inclusions in Siqueiros picritesEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p.336GlobalExperimental petrology, Picrites
DS201012-0012
2010
Sobolev, A.Arndt, N.T., Guitreau, M., Boullier, A-M., Le Roex, A., Tommasi, A.M., Cordier, P., Sobolev, A.Olivine, and the origin of kimberlite.Journal of Petrology, Vol. 51, 3, pp. 573-602.TechnologyKimberlite genesis
DS1994-1652
1994
Sobolev, A.F.Sobolev, A.F., Danyushevsky, L.V.Petrology and geochemistry of boninites from the north terminations of the Tonga Trench - high Ca magmas.Journal of Petrology, Vol. 35, pt. 5, pp. 1183-1211.GlobalBoninites
DS1984-0238
1984
Sobolev, A.V.Dmitriev, L.V., Sobolev, A.V., Uchanov, A.V., Malaysheva, T.V.Primary Differences in Oxygen Fugacity and Depth of Melting in the Mantle Source Regions for Oceanic Basalts.Earth Plan. Sci. Letters, Vol. 70, PP. 303-310.GlobalMineral Chemistry, Mid Ocean Ridge Basalt (morb)
DS1984-0686
1984
Sobolev, A.V.Sobolev, A.V., Slutskii, A.B.Composition and Crystallization Conditions of the Initial Melt of the Siberian Meimechites in Relation to the General Problem of Ultrabasic Magmas.Soviet Geology And Geophysics, Vol. 25, No. 12, PP. 93-104.RussiaMeimechite, Related Rocks
DS1984-0687
1984
Sobolev, A.V.Sobolev, A.V., Slutskiy, A.B.Composition and crystallization conditions of the initial melt of the Siberian meimechites in relation to the general Problem of ultrabasic magmasSoviet Geology and Geophysics, Vol. 25, No. 12, pp. 93-104RussiaMeimechites
DS1985-0634
1985
Sobolev, A.V.Sobolev, A.V., Sobolev, N.V., Smit, K.B.New Dat a on the Petrology of Olivine Lamproites of Western Australia Based on Results of the Investigation of Magmatic Inclusions in Olivines.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 284, No. 1, PP. 196-Australia, Western AustraliaLamproite, Petrology
DS1985-0635
1985
Sobolev, A.V.Sobolev, A.V., Sobolev, N.V., Smit, K.B., Kononkova, N.N.New dat a on the petrology of olivine lamproites of Western australia From the results of the investigation of magmatic inclusions in olivines.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 284, No. 1, pp. 196-201AustraliaLamproite, Inclusions
DS1986-0690
1986
Sobolev, A.V.Ryabchikov, I.D., Solovova, I.P., Sobolev, N.V., Sobolev, A.V.Nitrogen in lamproitic magmas.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 288, No. 4, pp. 976-979RussiaLamproite
DS1986-0762
1986
Sobolev, A.V.Sobolev, A.V., Sobolev, N.V., Smith, C.B., Dubessy, J.Pecularities in the fluid and melt compositions of the lamproites And kimberlites based on the study of inclusions inolivinesProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 93-94Australia, Russia, ArkansasLamproite
DS1987-0694
1987
Sobolev, A.V.Sobolev, A.V., Sobolev, N.V., Smith, C.B., Kononkova, N.N.New dat a on the petrology of the olivine lamproites of Western Australia revealed by the study of magmatic inclusions inolivineDoklady Academy of Science USSR, Earth Science Section, Vol. 284, No. 5, Publishing July 1987, pp. 106-110AustraliaLamproite, Petrology
DS1989-1419
1989
Sobolev, A.V.Sobolev, A.V., Sobolev, N.V., Smith, C.B., Dubessy, J.Fluid and melt compositions in lamproites And kimberlites based on the study of inclusions inolivineGeological Society of Australia Inc. Blackwell Scientific Publishing, Special, No. 14, Vol. 1, pp. 220-240Australia, RussiaEllendale, Mt. Cedric, Udachnaya, Geochemistry
DS1989-1426
1989
Sobolev, A.V.Sobolev, N.V., Sobolev, A.V., Pokhilenko, N.P., Yefimova, E.S.Chrome spinels coexisting with Yakutian diamondsDiamond Workshop, International Geological Congress, July 15-16th. editors, pp. 105-108. AbstractRussiaMineral chemistry, Chrome spinels
DS1990-0620
1990
Sobolev, A.V.Gurenko, A.A., Sobolev, A.V., Kononkova, N.N.New petrologic dat a on ugandites from the East African Rift, as revealed by study of magmatic inclusions in mineralsDoklady Academy of Science USSR, Earth Science Section, Vol. 305, No. 2, Sept. pp. 130-134UgandaPetrology, Ugandites
DS1990-0621
1990
Sobolev, A.V.Gurenko, A.A., Sobolev, A.V., Kononkova, N.N., Shcherbovskiy, Ye.Ya.Olivine from the ultrabasic and basic rocks of the East African rift system differentiated seriesGeochemistry International, Vol. 27, No. 10, pp. 117-123East AfricaPetrology, Ultrabasics -olivine -analyses
DS1990-0622
1990
Sobolev, A.V.Gurenko, A.A., Sobolev, A.V., Kononkova, N.N., Shcherbovsky, E.Y.Olivine of ultramafic and mafic rocks of the main differentiated seriesof the East African rift system (Russian)No. 3, March pp. 429-436, East AfricaGlobalPetrology
DS1991-0272
1991
Sobolev, A.V.Claoue-Long, J.C., Sobolev, N.V., Shatsky, V.S., Sobolev, A.V.Zircon response to diamond -pressure metamorphism in the Kokchetav USSRGeology, Vol. 19, No. 7, July pp. 710-713RussiaMicroprobe-SHRIMP, Geochronology -age populations
DS1992-0333
1992
Sobolev, A.V.Danyushevskiy, L.V., Sobolev, A.V., Kononkova, N.N.Methods of studying melt inclusions in minerals during investigations on water bearing primitive mantle melts (Tonga Trench boninites)Geochemistry International, Vol. 29, No. 7, pp. 48-61GlobalBoninites
DS1992-1444
1992
Sobolev, A.V.Sobolev, A.V., Kamenskiy, V.S., Kononkova, N.N.New dat a on Siberian meymechite petrologyGeochemistry International, Vol. 29, No. 3, pp. 10-20Russia, SiberiaPetrology, Meymechite
DS1993-0770
1993
Sobolev, A.V.Kamenetskiy, V.S., Portnyagin, M.V., Sobolev, A.V., DanyushevskiyMagma composition and crystallization conditions of the picrite-basalt suite in the Tumrok Ridge, East KamchatkaGeochemistry International, Vol.30, No. 3, March pp. 58-73RussiaPicrites
DS1993-1496
1993
Sobolev, A.V.Sobolev, A.V.Ion probe study of H2O in primary mantle melts: implications for the H2Ocontents and recycling in the mantle.American Geophysical Union, EOS, supplement Abstract Volume, October, Vol. 74, No. 43, October 26, abstract p. 682.MantleExperimental petrology, Mantle melts
DS1993-1497
1993
Sobolev, A.V.Sobolev, A.V., Shimizu, N.Ultra depleted primary melt included in an olivine from the Mid-AtlanticRidge.Nature, Vol. 363, No. 6425, May 13, pp. 151-154.Mid-Atlantic RidgeBlank
DS1994-0678
1994
Sobolev, A.V.Gurenko, A.A., Sobolev, A.V., Kononkova, N.N.The East African rift as indicated by magma inclusions in the mineralsDoklady Academy of Sciences Acad. Science USSR, Vol. 323, No. 2, June pp. 94-100.KenyaTectonics, Petrology
DS1995-1792
1995
Sobolev, A.V.Sobolev, A.V.Melt inclusions as a source of principal petrologic informationEos, Abstracts, Vol. 76, No. 17, Apr 25, p. S 266.MantleMelt, Mantle plumes
DS1996-1338
1996
Sobolev, A.V.Sobolev, A.V.Melt inclusions in minerals as a source of principle petrologicalinformationPetrology, Vol. 4, No. 3, pp. 209-220RussiaMelts, magmas, Petrology
DS1996-1339
1996
Sobolev, A.V.Sobolev, A.V., Chaussidon, M.H2O concentrations in primary melts from supra subduction zones and mid-ocean ridges: implications ...Earth and Planetary Science Letters, Vol. 137, No. 1/4, Jan. 1, pp. 45-56.MantleRecycling, Subduction
DS1996-1340
1996
Sobolev, A.V.Sobolev, A.V., Chaussidon, M.H2O concentrations in primary melts from supra subduction zones in mid-ocean ridges: storage/recyclingEarth and Planetary Science Letters, Vol. 137, No. 1-4, Jan. 1, pp. 45-56MantleWater storage, Subduction, Primary melts
DS2002-0349
2002
Sobolev, A.V.Danyushevsky, L.V., McNeill, A.W., Sobolev, A.V.Experimental and petrological studies of melt inclusions in phenocrysts from mantle derived magmas:Chemical Geology, Vol.183, 1-4, pp.5-24.MantleOverview - techniques, advantages and complications, Magmas
DS2002-0805
2002
Sobolev, A.V.Kamenetsky, V.S., Sobolev, A.V., Eggins, S.M., CrawfordOlivine enriched melt inclusions in chromites from low Ca boninites, Cape Vogel: ultramafic primary magmaChemical Geology, Vol.183, 1-4, pp.287-303.Papua New GuineaMagma - refractory mantle source and enriched component, sub calcic, Geochemistry
DS200512-0461
2005
Sobolev, A.V.Ionov, D., Prikhodko, V.S., Bodinier, J.L., Sobolev, A.V., Weis, D.Lithospheric mantle beneath the south eastern Siberian Craton: petrology of peridotite xenoliths in basalts from the Tokinsky Stanovik.Contributions to Mineralogy and Petrology, Vol. 149, no. 6, pp. 647-665.Russia, SiberiaXenoliths
DS200512-0495
2004
Sobolev, A.V.Kamenetsky, M.B., Sobolev, A.V., Kamenetsky, V.S., Maas, R., Danyushevsky, L.V., Thomas, R., Pokhilenko, N.P., Sobolev, N.V.Kimberlite melts rich in alkali chlorides and carbonates: a potent metasomatic agent in the mantle.Geology, Vol. 32, 10, Oct. pp. 845-848.Russia, Siberia, YakutiaUdachnaya, Group I, volatiles, metasomatism, inclusions
DS200512-0666
2005
Sobolev, A.V.Maas, R., Kamenetsky, M.B., Sobolev, A.V., Kamenetsky, V.S., Sobolev, N.V.Sr Nd Pb isotope evidence for a mantle origin of alkali chlorides and carbonates in the Udachnaya kimberlite, Siberia.Geology, Vol. 33, 7, July, pp. 549-552.Russia, SiberiaGeochronology - Udachnaya
DS200612-0006
2005
Sobolev, A.V.Akinin, V.V., Sobolev, A.V., Ntaflos, T., Richter, W.Clinopyroxene megacrysts from Enmelen melanephelinitic volcanoes (Chukchi Peninsula, Russia): application to composition and evolution of mantle melts.Contributions to Mineralogy and Petrology, Vol. 150, 1, pp. 85-101.RussiaNephelinite
DS200612-0514
2006
Sobolev, A.V.Gurenko, A.A., Sobolev, A.V.Petrology and geochemistry of East African kamafugites: constraints from inclusions in minerals.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 220. abstract only.Africa, UgandaGeochemistry
DS200612-0655
2006
Sobolev, A.V.Kamenetsky, M.B., Kamenetsky, V.S., Crawford, Chung, S-L., Kuzmin, A.J.D.V., Sobolev, A.V.Heterogeneous primary melts of the Emeishan picrites: contribution from eclogite to plume magmas.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 2. abstract only.ChinaEclogite
DS200612-0660
2006
Sobolev, A.V.Kamenetsky, V.S., Kamenetsky, M.B., Sharygin, V.V., Maas, R., Faure, K., Sobolev, A.V.Why are Udachnaya East pipe kimberlites enriched in Cl and alkalis but poor in H2O?Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 3. abstract only.Russia, YakutiaDeposit - Udachnaya mineral chemistry
DS200612-1330
2006
Sobolev, A.V.Sobolev, N.V., Logvinova, A.M., Zedgenizov, D.A., Kuzmin, D.V., Sobolev, A.V.Olivine inclusions in Siberian diamonds: high precision approach to trace elements.International Mineralogical Association 19th. General Meeting, held Kobe, Japan July 23-28 2006, Abstract p. 137.Russia, SiberiaGeochemistry - mineral inclusiosn
DS200612-1391
2006
Sobolev, A.V.Sumino, H., Kaneoka, I., Matsufuji, K., Sobolev, A.V.Deep mantle origin of kimberlite magmas revealed by neon isotopes.Geophysical Research Letters, Vol. 33, L1618Russia, SiberiaGeochemistry - noble gases Udachnaya, MORB
DS200612-1392
2006
Sobolev, A.V.Sumino, H., Kaneoka, I., Matsufuji, K., Sobolev, A.V.Deep mantle origin of kimberlite magmas revealed by neon isotopes.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 624. abstract only.Russia, YakutiaGeochronology
DS200712-1008
2007
Sobolev, A.V.Sobolev, A.V.The amount of recycled crust in sources of mantle derived melts.Science, Vol. 316, no. 5823, April 20, pp. 412-416.MantleMelting
DS200712-1009
2007
Sobolev, A.V.Sobolev, A.V.Melt inclusions and host olivines: what do they tell about mantle processes and sources?Plates, Plumes, and Paradigms, 1p. abstract p. A951.MantleMelting
DS200812-0537
2008
Sobolev, A.V.Kamenetsky, M.B., Kamenenetsky, V.S., Sobolev, A.V., Golovin, Sharygin, Demouchy, Faure, KuzminOlivine in the Udachnaya East kimberlite ( Yakutia, Russia): morphology, compositional zoning and origin.9IKC.com, 3p. extended abstractRussiaDeposit - Udachnaya petrograaphy
DS200812-0538
2008
Sobolev, A.V.Kamenetsky, M.B., Kamenetsky, V.S, Sobolev, A.V., Golovin, A.V.Can pyroxenes be liquidus minerals in the kimberlite magma?9IKC.com, 3p. extended abstractRussiaDeposit - Udachnaya
DS200812-0541
2008
Sobolev, A.V.Kamenetsky, V.S., Kamentsky, M.B., Sobolev, A.V., Golovin, A.V., Demouchy, S., Faure, Sharygin, KuzminOlivine in the Udachnaya east kimberlite ( Yakutia, Russia): types, compositions and origins.Journal of Petrology, Vol. 49, 4, pp. 823-839.Russia, YakutiaDeposit - Udachnaya
DS200812-1090
2008
Sobolev, A.V.Sobolev, A.V.Recycled crust as a cause of large magmatic events in the convecting mantle.Goldschmidt Conference 2008, Abstract p.A880.MantleSubduction
DS200812-1091
2008
Sobolev, A.V.Sobolev, A.V., Hofmann, A.W., Brugmann, G., Batanova, V.G., Kuzmin, D.V.A quantitative link between recycling and osmium isotopes.Science, Vol. 321, 5888, July 25, p. 536.MantleSubduction
DS200812-1092
2008
Sobolev, A.V.Sobolev, N.V., Logvinova, A.M., Zedgenizov, D.A., Pokhilenko, N.P., Kuzmin, D.V., Sobolev, A.V.Olivine inclusions in Siberian diamonds: high precision approach to minor elements.European Journal of Mineralogy, Vol. 20, no. 3, pp. 305-315.Russia, SiberiaDiamond inclusions
DS200912-0273
2009
Sobolev, A.V.Gurenko, A.A., Sobolev, A.V., Hoernle, K.A., Hauff, F., Schincka, H-U.Enriched, HIMU type peridotite and depleted recycled pyroxenite in the Canary plume: a mixed up mantle.Earth and Planetary Science Letters, Vol. 277, 3-4, Jan. 30, pp. 514-524.Europe, Canary IslandsGeothermometry - subduction
DS200912-0669
2008
Sobolev, A.V.Savelieva, G.N., Sobolev, A.V., Batanova, V.G., Suslov, P.V., Brugmann, G.Structure of melt flow channels in the mantle.Geotectonics, Vol. 42, 6, pp. 430-447.MantleMelting
DS200912-0706
2009
Sobolev, A.V.Sobolev, A.V., Krivolutskaya, N.A., Kuzmin, D.V.Petrology of the parental melts and mantle sources of Siberian trap magmatism.Petrology, Vol. 17, 3, May pp. 253-286.RussiaMagmatism - Not specific to diamonds
DS200912-0708
2009
Sobolev, A.V.Sobolev, N.V., Logvinova, A.M., Zedgenizov, D.A., Pokhilenko, N.P., Malygina, E.V., Kuzmin, D.V., Sobolev, A.V.Petrogenetic significance of minor elements in olivines from diamonds and peridotite xenoliths from kimberlites of Yakutia.Lithos, In press - available 38p.Russia, YakutiaDiamond inclusions
DS200912-0838
2009
Sobolev, A.V.Yaxley, G.M., Spandler, C.S., Sobolev, A.V., Rosenthal, A., Green, D.H.Melting and melt peridotite interactions in heterogeneous upper mantle sources of primitive volcanics.Goldschmidt Conference 2009, p. A1482 Abstract.MantleMelting
DS201012-0335
2009
Sobolev, A.V.Kamenetsky, V.S., Kamenetsky, M.B., Sobolev, A.V., Golovin, A.V., Sharyginb, V.V., Pokhilenko, N.P., Sobolev, N.V.Can pyroxenes be liquidus minerals in the kimberlite magma?Lithos, Vol. 112 S pp. 213-235.MantleChemistry
DS201012-0733
2009
Sobolev, A.V.Sobolev, A.V., Sobolev, S.V., Kuzmin, D.V., Malitch, K.N., Petrunin, A.G.Siberian meimechites: origin and relation to flood basalts and kimberlites.Russian Geology and Geophysics, Vol. 50, 12, pp. 999-1033.Russia, SiberiaMeimechite
DS201212-0683
2012
Sobolev, A.V.Sobolev, N.V., Sobolev, A.V., Tomilenko, A.A., Kovyazin, S.V., Kuzmin, D.V.Pyrope lherzolite assemblage of Ti bearing olivine macrocryst from Udachanya ultrafresh kimberlite, Yakutia, Russia.emc2012 @ uni-frankfurt.de, 1p. AbstractRussiaDeposit - Udachnaya
DS201412-0863
2014
Sobolev, A.V.Sobolev, N.V., Sobolev, A.V., Tomilenko, A.A., Kovyazin, S.V., Batanova, V.G., Kuzmin, D.V.Paragenesis and origin of olivine macrocrysts from Udachnaya-East hypabyssal kimberlite, Yakutia, Russia.V.S. Sobolev Institute of Geology and Mineralogy Siberian Branch Russian Academy of Sciences International Symposium Advances in high pressure research: breaking scales and horizons ( Courtesy of N. Poikilenko), Held Sept. 22-26, 2p. AbstractRussia, YakutiaDeposit - Udachnaya-East
DS201502-0041
2014
Sobolev, A.V.Batanova, V.G., Lyaskovskaya, Z.E., Savelieva, G.N., Sobolev, A.V.Peridotites from the Kamchatsky Mys: evidence of oceanic mantle melting near a hotspot.Russian Geology and Geophysics, Vol. 55, pp. 1395-1403.RussiaHarzburgite, plumes

Abstract: A suite of mantle peridotites sampled in the Kamchatsky Mys includes spinel lherzolite, clinopyroxene-bearing harzburgite, and harzburgite. Mineral chemistry of olivine, chromian spinel, and clinopyroxene show strongly correlated element patterns typical of peridotite formed by 8% to more than 22% partial melting. Clinopyroxene in the Kamchatka peridotites is compositionally different from that of both abyssal and suprasubduction varieties: Clinopyroxene in lherzolite is depleted in LREE relative to abyssal peridotite and that in harzburgite has very low LREE and Sr unlike the subduction-related counterpart. These composition features indicate that the rocks ultra-depleted in basaltic components originated in the vicinity of a hotspot, possibly, proto-Hawaiian plume, which provided high temperature and melting degree of the MORB source mantle at mid-ocean ridge.
DS201502-0104
2015
Sobolev, A.V.Sobolev, N.V., Sobolev, A.V., Tomilenko, A.A., Kovyazin, S.V., Batanova, V.G., Kuzmin, D.V.Paragenesis and complex zoning of olivine macrocrysts from unaltered kimberlite of the Udachnaya-East pipe, Yakutia: relationship with the kimberlite formation conditions and evolution.Russian Geology and Geophysics, Vol. 56, 1, pp. 260-279.Russia, YakutiaDeposit - Udachnaya-East
DS201510-1805
2015
Sobolev, A.V.Sobolev, N.V., Sobolev, A.V., Tomilenko, A.A., Batanova, V.G., Tolstov, A.V., Logvinova, A.M., Kuzmin, D.V.Unique compositional pecularities of olivine phenocrysts from the post flood basalt Diamondiferous Malokuonapskaya kimberlite pipe, Yakutia.Doklady Earth Sciences, Vol. 463, 2, pp. 828-832.RussiaDeposit - Malokuonapskaya
DS201605-0903
2016
Sobolev, A.V.Sobolev, A.V., Asafov, E.V., Gurenko, A.A., Arndt, N.T., Batanova, V.G., Portnyagin, M.V., Garbe-Schonberg, D., Krasheninnikov, S.P.Komatites reveal a hydrous Archaen deep mantle reservoir.Nature, Vol. 531, Mar. 31, pp. 628-632.MantleMelting

Abstract: Archaean komatiites (ultramafic lavas) result from melting under extreme conditions of the Earth’s mantle. Their chemical compositions evoke very high eruption temperatures, up to 1,600 degrees Celsius, which suggests even higher temperatures in their mantle source1, 2. This message is clouded, however, by uncertainty about the water content in komatiite magmas. One school of thought holds that komatiites were essentially dry and originated in mantle plumes3, 4, 5, 6 while another argues that these magmas contained several per cent water, which drastically reduced their eruption temperature and links them to subduction processes7, 8, 9. Here we report measurements of the content of water and other volatile components, and of major and trace elements in melt inclusions in exceptionally magnesian olivine (up to 94.5?mole per cent forsterite). This information provides direct estimates of the composition and crystallization temperature of the parental melts of Archaean komatiites. We show that the parental melt for 2.7-billion-year-old komatiites from the Abitibi greenstone belt in Canada contained 30 per cent magnesium oxide and 0.6 per cent water by weight, and was depleted in highly incompatible elements. This melt began to crystallize at around 1,530 degrees Celsius at shallow depth and under reducing conditions, and it evolved via fractional crystallization of olivine, accompanied by minor crustal assimilation. As its major- and trace-element composition and low oxygen fugacities are inconsistent with a subduction setting, we propose that its high H2O/Ce ratio (over 6,000) resulted from entrainment into the komatiite source of hydrous material from the mantle transition zone10. These results confirm a plume origin for komatiites and high Archaean mantle temperatures, and evoke a hydrous reservoir in the deep mantle early in Earth’s history.
DS201610-1877
2016
Sobolev, A.V.Kamenetsky, V.S., Maas, R., Kamenetsky, M.B., Yaxley, G.M., Ehrig, K., Zellmer, G.F., Bindeman, I.N., Sobolev, A.V., Kuzmin, D.V., Ivanov, A.V., Woodhead, J., Schilling, J-G.Multiple mantle sources of continental magmatism: insights from "high-Ti" picrites of Karoo and other large igneous provinces.Chemical Geology, in press available 10p.Africa, South AfricaLIP magmatism

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

Abstract: Magmas forming large igneous provinces (LIP) on continents are generated by extensive melting in the deep crust and underlying mantle and associated with break-up of ancient supercontinents, followed by formation of a new basaltic crust in the mid-oceanic rifts. A lack of the unifying model in understanding the sources of LIP magmatism is justified by lithological and geochemical complexity of erupted magmas on local (e.g. a cross-section) and regional (a single and different LIP) scales. Moreover, the majority of LIP rocks do not fit general criteria for recognizing primary/primitive melts (i.e. < 8 wt% MgO and absence of high-Fo olivine phenocrysts). This study presents the mineralogical (olivine, Cr-spinel, orthopyroxene), geochemical (trace elements and Sr-Nd-Hf-Pb isotopes) and olivine-hosted melt inclusion compositional characteristics of a single primitive (16 wt% MgO), high-Ti (2.5 wt% TiO2) picrite with high-Mg olivine (up to 91 mol% Fo) from the Letaba Formation in the ~ 180 Ma Karoo LIP (south Africa). The olivine compositions (unusually high ?18O (6.17‰), high NiO (0.36–0.56 wt%) and low MnO and CaO (0.12–0.20 and 0.12–0.22 wt%, respectively)) are used to argue for a non-peridotitic mantle source. This is supported by the enrichment of the rock and melts in most incompatible trace elements and depletion in heavy rare earth elements (e.g. high Gd/Yb) that reflects residual garnet in the source of melting. The radiogenic isotopes resemble those of the model enriched mantle (EM-1) and further argue for a long-term enrichment of the source in incompatible trace elements. The enriched high-Ti compositions, strongly fractionated incompatible trace elements, presence of primitive olivine and high-Cr spinel in the Letaba picrites are closely matched by olivine-phyric rocks from the ~ 260 Ma Emeishan (Yongsheng area, SW China) and ~ 250 Ma Siberian (Maimecha-Kotuy region, N Siberia) LIPs. However, many other compositional parameters (e.g. trace element and ?18O compositions of olivine phenocrysts, Fe2 +/Fe3 + in Cr-spinel, Sr-Nd-Hf isotope ratios) only partially overlap or even diverge. We thus imply that parental melts of enriched picritic rocks with forsteritic olivine from three major continental igneous provinces – Karoo, Emeishan and Siberia cannot be assigned to a common mantle source and similar melting conditions. The Karoo picrites also exhibit some mineralogical and geochemical similarities with rocks and glasses in the south Atlantic Ridge and adjacent fracture zones. The geodynamic reconstructions of the continental plate motions since break-up of the Gondwanaland in the Jurassic support the current position of the source of the Karoo magmatism in the southernmost Atlantic. Co-occurrence of modern and recent anomalous rocks with normal mid-ocean ridge basalts in this region can be related to blocks/rafts of the ancient lithosphere, stranded in the ambient upper mantle and occasionally sampled by rifting-related decompressional melting.
DS201707-1376
2017
Sobolev, A.V.Trela, J., Gazel, E., Sobolev, A.V., Moore, L., Bizimis, M.The hottest lavas of the Phanerozoic and the survival of Archean reservoirs.Nature Geoscience, Vol. 10, 6, pp. 451-456.Mantleplumes

Abstract: Large igneous provinces and some hotspot volcanoes are thought to form above thermochemical anomalies known as mantle plumes. Petrologic investigations that support this model suggest that plume-derived melts originated at high mantle temperatures (greater than 1,500?°C) relative to those generated at ambient mid-ocean ridge conditions (about 1,350?°C). Earth’s mantle has also cooled appreciably during its history and the temperatures of modern mantle derived melts are substantially lower than those produced during the Archaean (2.5 to 4.0 billion years ago), as recorded by komatiites (greater than 1,700?°C). Here we use geochemical analyses of the Tortugal lava suite to show that these Galapagos-Plume-related lavas, which formed 89 million years ago, record mantle temperatures as high as Archaean komatiites and about 400?°C hotter than the modern ambient mantle. These results are also supported by highly magnesian olivine phenocrysts and Al-in-olivine crystallization temperatures of 1,570 ± 20?°C. As mantle plumes are chemically and thermally heterogeneous, we interpret these rocks as the result of melting the hot core of the plume head that produced the Caribbean large igneous province. Our results imply that a mantle reservoir as hot as those responsible for some Archaean lavas has survived eons of convection in the deep Earth and is still being tapped by mantle plumes.
DS201711-2532
2017
Sobolev, A.V.Trela, J., Gazel, E., Sobolev, A.V., Moore, L., Bizimis, M., Jicha, B., Batanova, V.G.The hottest lavas of the Phanerozoic and the survival of deep Archean reservoirs.Nature Geoscience, Vol. 10, pp. 451-456.Mantlegeodynamics - plumes

Abstract: Large igneous provinces and some hotspot volcanoes are thought to form above thermochemical anomalies known as mantle plumes. Petrologic investigations that support this model suggest that plume-derived melts originated at high mantle temperatures (greater than 1,500?°C) relative to those generated at ambient mid-ocean ridge conditions (about 1,350?°C). Earth’s mantle has also cooled appreciably during its history and the temperatures of modern mantle derived melts are substantially lower than those produced during the Archaean (2.5 to 4.0 billion years ago), as recorded by komatiites (greater than 1,700?°C). Here we use geochemical analyses of the Tortugal lava suite to show that these Galapagos-Plume-related lavas, which formed 89 million years ago, record mantle temperatures as high as Archaean komatiites and about 400?°C hotter than the modern ambient mantle. These results are also supported by highly magnesian olivine phenocrysts and Al-in-olivine crystallization temperatures of 1,570 ± 20?°C. As mantle plumes are chemically and thermally heterogeneous, we interpret these rocks as the result of melting the hot core of the plume head that produced the Caribbean large igneous province. Our results imply that a mantle reservoir as hot as those responsible for some Archaean lavas has survived eons of convection in the deep Earth and is still being tapped by mantle plumes.
DS201810-2301
2018
Sobolev, A.V.Chayka, I.F., Izokh, A.E., Sobolev, A.V., Batanova, V.G.Low titanium lamproites of the Ryabinoviy Massif ( Aldan shield): crystallization conditions and lithospheric source.Doklady Earth Sciences, Vol. 481, 2, pp. 1008-1012.Russia, Aldan shieldlamproite

Abstract: Obtained data shows that high-potassic dyke rocks of the Ryabinoviy massif (Central Aldan) belong to low-titanium lamproite series (Mediterranean type) and are distinct with “classic” high-titanium lamproites. Based on Al-in-olivine thermometer, temperature of olivine-chrome-spinel pair crystallization varies in range between 1100 and 1250°C. This suggests lithospheric mantle source for the parental melt and makes role of mantle plume insignificant. High-precision data on olivine composition and bulk rock traceelement composition imply mixed source for the parental melt, consisted of depleted peridotite and enriched domains, originated during ancient subduction.
DS201811-2577
2018
Sobolev, A.V.Gurenko, A.A., Sobolev, A.V.Can orthopyroxene be present in the source of Toro-Ankole, East African Rift, kamafugites?Journal of Petrology, Vol. 59, 8, pp. 1517-1550.Africa, Ugandakamafugites

Abstract: We have studied mineral-hosted melt, crystal and fluid inclusions from two ugandite, one mafurite and two katungite samples from the Toro-Ankole volcanic province in the East African Rift, which is the archetypal location for kamafugitic rocks. A main finding of our study is the presence of orthopyroxene as inclusions in an early generation of olivine from all three types of kamafugites, suggesting interaction of a carbonate-rich metasomatic agent with lithospheric peridotite mantle that may have caused almost complete dissolution of orthopyroxene. This process was preceded, accompanied or followed by the formation of phlogopite-clinopyroxene veins resulting from interaction of F-rich and low H2O/CO2 metasomatic fluids with the mantle rocks, which then became the source of the Toro-Ankole kamafugites. Pressure-temperature (P-T) estimates suggest that the parental kamafugitic melts last equilibrated with their source rocks at ?16?±?8?kbar and ?1160?±?130°C. This implies that they could have originated significantly below the solidus of dry, carbonated peridotite, but above the solidus of phlogopite-bearing clinopyroxenite. We conclude that the Toro-Ankole kamafugites originated by very low degrees of partial melting at moderately oxidized conditions (?FMQ = +2•2?±?0•4?atm log units, where FMQ is fayalite-magnetite-quartz buffer) under a high geothermal gradient of 60-80?mW?m?2, in response to lithospheric extension and probable association with an adjacent mantle plume. We estimate that differentiation of parental ugandite, mafurite and katungite magmas could have occurred at depths <12?km in the T range 1150-850°C. Laboratory-heated, homogenized melt inclusions trapped by a second generation of olivine and clinopyroxene are characterized by remarkable silica-undersaturation, compared with mid-ocean ridge basalt and ocean island basalt magmas, with high concentrations of alkalis, Ti, Ba, Sr and Zr, but varying to very low concentrations of Al and Ca. Such alkali-rich, strongly evolved melts might have resulted from extreme (>95%) fractional crystallization of the parental magmas, assuming their chemical compositions to be similar to those of the respective lavas. However, this estimate is about three times higher than the modal amount of phenocrysts in the lavas that could be reinforced by the presence of excess cognate crystals and/or xenocrysts in the lavas. Strong oxidation from FMQ?+?2 to FMQ?+?4 to +?5•2?atm log units of the evolved mafuritic magmas at ?900-1000°C has occurred during the final stage of magma evolution at very shallow crustal depths or possibly directly in the lava flow.
DS201907-1527
2019
Sobolev, A.V.Batanova, V.G., Thompson, J.M., Danyushevsky, L.V., Portnyagin, M.V., Garbe-Schonberg, D., Hauri, E., Kimura, J-I., Chang, Q., Senda, R., Goemann, K., Chauvel, C., Campillo, S., Ionov, D.A., Sobolev,A.V.New olivine reference material for in situ microanalysis.Geostandards and Geoanalytical Research, in press available, 21p.Asia, Mongoliaolivine

Abstract: A new olivine reference material - MongOL Sh11?2 - for in situ analysis has been prepared from the central portion of a large (20 × 20 × 10 cm) mantle peridotite xenolith from a ~ 0.5 My old basaltic breccia at Shavaryn?Tsaram, Tariat region, central Mongolia. The xenolith is a fertile mantle lherzolite with minimal signs of alteration. Approximately 10 g of 0.5-2 mm gem quality olivine fragments were separated under binocular microscope and analysed by EPMA, LA?ICP?MS, SIMS and bulk analytical methods (ID?ICP?MS for Mg and Fe, XRF, ICP?MS) for major, minor and trace elements at six institutions world?wide. The results show that the olivine fragments are sufficiently homogeneous with respect to major (Mg, Fe, Si), minor and trace elements. Significant inhomogeneity was revealed only for phosphorus (homogeneity index of 12.4), whereas Li, Na, Al, Sc, Ti and Cr show minor inhomogeneity (homogeneity index of 1-2). The presence of some mineral and fluid?melt micro?inclusions may be responsible for the inconsistency in mass fractions obtained by in situ and bulk analytical methods for Al, Cu, Sr, Zr, Ga, Dy and Ho. Here we report reference and information values for twenty?seven major, minor and trace elements.
DS201907-1576
2019
Sobolev, A.V.Sobolev, A.V., Asafov, E., Arndt, N., Portnyagin, M., Guenko, A.A., Batanova, G., Garbe-Schonberg, D., Wilson, A.H., Byerly, G., Batanova, V.Deep hydrous mantle reservoir provides evidence for crustal recycling before 3.3 billion years ago.Nature, 32p. Pdf availableMantlewater

Abstract: H2O strongly influences physical properties of the mantle and its ability to melt or convect and can trace recycling of surface reservoirs down to the deep mantle1,2. This makes knowledge of water content in the Earth's interior and its evolution through time crucial to understanding global geodynamics. Komatiites (MgO-rich ultramafic magmas) result from high-degree mantle melting at high pressures3 and thus are excellent probes of H2O contents in the deep mantle. A significant excess of H2O over elements of similar geochemical behavior during mantle melting (e.g. Ce) was recently found in melt inclusions in the most Mg-rich olivine in 2.7 Ga old komatiites from Canada4 and Zimbabwe5. These data were taken as evidence for a deep hydrated mantle reservoir, probably the transition zone, in the Neoarchean time. In this paper we confirm the mantle source of this H2O by measurement of deuterium to hydrogen ratios in these melt inclusions and present similar data for 3.3 Ga old komatiites from the Barberton Greenstone Belt. Using hydrogen isotopes, we show that the mantle sources of these melts contained excess H2O which implies that a deep mantle hydrated reservoir has been present in the Earth's interior at least since the Paleoarchean. The reconstructed initial hydrogen isotope composition of komatiites is significantly more depleted in deuterium than all surface reservoirs and typical mantle but resembles that in dehydrated subducted slabs. Together with a significant excess of chlorine and a temporal trend of Pb/Ce in the mantle sources of komatiites, these results argue that lithosphere recycling into the deep mantle, arguably via subduction, started before 3.3 Ga. (a un-reviewed version of the manuscript accepted for publication in Nature magazine).
DS202006-0914
2020
Sobolev, A.V.Chayka, I.F., Sobolev, A.V., Izokh, A.E., Batanova, V.G., Krasheninnikov, S.P., Chervyakovskaya, M.V., Kontonikas-Charos, A., Kutyrev, A.V., Lobastov, B.M., Chervyakovskiy, V.S.Fingerprints of kamafugite-like magmas in Mesozoic lamproites of the Aldan Shield: evidence from olivine and olivine-hosted inclusions.Minerals, Vol. 10, 4, 30p.Russia, Siberiadeposit - Ryabinoviy

Abstract: Mesozoic (125-135 Ma) cratonic low-Ti lamproites from the northern part of the Aldan Shield do not conform to typical classification schemes of ultrapotassic anorogenic rocks. Here we investigate their origins by analyzing olivine and olivine-hosted inclusions from the Ryabinoviy pipe, a well preserved lamproite intrusion within the Aldan Shield. Four types of olivine are identified: (1) zoned phenocrysts, (2) high-Mg, high-Ni homogeneous macrocrysts, (3) high-Ca and low-Ni olivine and (4) mantle xenocrysts. Olivine compositions are comparable to those from the Mediterranean Belt lamproites (Olivine-1 and -2), kamafugites (Olivine-3) and leucitites. Homogenized melt inclusions (MIs) within olivine-1 phenocrysts have lamproitic compositions and are similar to the host rocks, whereas kamafugite-like compositions are obtained for melt inclusions within olivine-3. Estimates of redox conditions indicate that “lamproitic” olivine crystallized from anomalously oxidized magma (?NNO +3 to +4 log units.). Crystallization of "kamafugitic" olivine occurred under even more oxidized conditions, supported by low V/Sc ratios. We consider high-Ca olivine (3) to be a fingerprint of kamafugite-like magmatism, which also occurred during the Mesozoic and slightly preceded lamproitic magmatism. Our preliminary genetic model suggests that low-temperature, extension-triggered melting of mica- and carbonate-rich veined subcontitental lithospheric mantle (SCLM) generated the kamafugite-like melts. This process exhausted carbonate and affected the silicate assemblage of the veins. Subsequent and more extensive melting of the modified SCLM produced volumetrically larger lamproitic magmas. This newly recognized kamafugitic "fingerprint" further highlights similarities between the Aldan Shield potassic province and the Mediterranean Belt, and provides evidence of an overlap between "orogenic" and "anorogenic" varieties of low-Ti potassic magmatism. Moreover, our study also demonstrates that recycled subduction components are not an essential factor in the petrogenesis of low-Ti lamproites, kamafugites and leucitites.
DS1991-1570
1991
Sobolev, A.Y.Shnai, G.K., Sobolev, A.Y., Igoshina, I.I.Lamproites of southern Verkhoyansk region.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 319, No. 4, pp. 957-961RussiaLamproites
DS1993-1455
1993
Sobolev, A.Ye.Shnay, G.K., Sobolev, A.Ye., Igoshina, I.I.Verkhoyansk-region lamproites resembling Australian diamond bearinglamproites.Doklady Academy of Sciences USSR, Earth Science Section, Vol. 319A, No. 6, Publishing July 1993, pp. 166-171.RussiaLamproites
DS1986-0768
1986
Sobolev, E.V.Sobolev, N.V., Sobolev, E.V., Yefimova, E.S.Some physical and chemical characteristics of diamonds from Copeton New south Wales. Reference to Proceedings 20th.International Gemmological Conference ptThe Australian Gemologist, Vol. 16, No. 3, p. 119. abstractAustraliaDiamond, Morphology
DS1991-1621
1991
Sobolev, E.V.Sobolev, E.V.The impurity centers and some problems of diamond genesisProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 388-390RussiaPoly, orphisM., Diamond morphology, natural, nitrogen
DS1993-1498
1993
Sobolev, E.V.Sobolev, N.V., Galimov, E.M., Efimova, E.S., Sobolev, E.V.Crystalline inclusions, isotopes carbon, nitrogen centers in diamonds, features of garnet from Madjgawan.Russian Geology and Geophysics, Vol. 34, No. 12, pp. 77-83.IndiaDiamond inclusions, Deposit -Madjgawan
DS1995-1638
1995
Sobolev, E.V.Rylov, G.M., Sobolev, E.V.Investigation of B1 defects in natural diamonds using double crystaltechnique.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 479-480.RussiaDiamond morphology, Diamond crystallography
DS1997-0568
1997
Sobolev, N.Kadik, A.A., Zharkova, E.V., Efimova, E.S., Sobolev, N.Redox conditions of the formation of diamond crystals: electrochemicalinvestigations.Doklady Academy of Sciences, Vol. 355A, No. 6, July-Aug. pp. 1370-74.GlobalDiamond morphology, Crystallography
DS2003-0733
2003
Sobolev, N.Koch-Muller, M., Dera, M., Fei, Y., Reno, B., Sobolev, N., Hauri, E.OH in synthetic and natural coesiteAmerican Mineralogist, Vol. 88, 10, Oct. pp. 1436-45.GlobalMineralogy - coesite
DS200412-1024
2003
Sobolev, N.Koch-Muller, M., Dera, M., Fei, Y., Reno, B., Sobolev, N., Hauri, E., Wysoczanski, R.OH in synthetic and natural coesite.American Mineralogist, Vol. 88, 10, Oct. pp. 1436-45.TechnologyMineralogy - coesite
DS200912-0707
2008
Sobolev, N.Sobolev, N., Wirth, R., Logvinova, A.M., Pokhilenko, N.P., Kuzmin, D.V.Retrograde phase transitions of majorite garnets included in diamonds: a case study of subcalcic Cr rich majorite pyrope from a Snap Lake diamond, Canada.American Geological Union, Fall meeting Dec. 15-19, Eos Trans. Vol. 89, no. 53, meeting supplement, 1p. abstractCanada, Northwest TerritoriesDeposit - Snap lake
DS201412-0504
2013
Sobolev, N.Lenaz, D., Skogby, H., Logvinova, A., Sobolev, N., Princivalle, F.A micro-mossbauer study of chromites included in diamond and other mantle related rocks.Physics and Chemistry of Minerals, Vol. 40, 9, pp. 671-679.Russia, SiberiaDiamond inclusions
DS201412-0861
2014
Sobolev, N.Sobolev, N.Ultrahigh pressure mineralogy of the continental lithosphere.ima2014.co.za, IMA Medallist lectureMantleUHP
DS201907-1572
2019
Sobolev, N.Shatsky, V., Jagoutz, E., Kozmenko, O., Ragozin, A., Skuzovatov, S., Sobolev, N.The protolith nature of diamondiferous metamorphic rocks of the Kokchetav Massif.Acta Geologica Sinica, Vol. 93, 1, p. 173-Russiadeposit - Kokchetav

Abstract: International Symposium on Deep Earth Exploration and Practices Beijing, China -October24-26, 2018The protolithnatureof diamondiferous metamorphic rocks of the Kokchetav MassifVladislav Shatsky1,2,3, Emil Jagoutz4, Olga Kozmenko1, Alexey Ragozin1,3, Sergei Skuzovatov2and Nikolai Sobolev1,31Sobolev Institute of Geology and Mineralogy SB RAS, Novosibirsk, 630090, Russia, [email protected] Institute of Geochemistry SB RAS, Irkutsk, Russia3Novosibirsk State University, Novosibirsk, Russia4Max Planck Institute for Chemistry, Mainz, GermanyUltra-high-pressure diamondiferous rocks (UHP) of the Kokchetav subduction-collision zone are considered as an idealobject for studying the mobility of elements insubduction zones of the continental type. The compositional diversity of metasedimentary rocks subjected to UHP metamorphism makes it difficult to establish the nature of their protoliths. This, in turn, complicates estimatesof the degree of depletionof the UHP metamorphic rocks relative to the protoliths.To clarify the nature of protholiths of the Kokchetav diamondiferous rocks we studied the geochemical features and Sm-Nd isotopic composition of diamondiferous calc-silicate, garnet-pyroxene rocks, high-alumina metapelitesand barren granite-gneisses.The nine samples of the Kumdy Kol mocrodiamond deposit (one granite-gneiss, 4-calc-silicate rocks, 3-garnet-pyroxenite) yielded aSm-Nd whole-rockisochronageof 1052±44 Ma. This age is close to the age of formation of the granitic gneiss basement of the Kokchetav massif (1.2-1.05 Ga) (Glorie et al., 2015). Therefore, we assume that the protoliths of these rocks were basementrocks. In this interpretation, their geochemical features may not be directly related to the processes of ultrahigh-pressure metamorphism.At the same time, the high-alumina rocks of the Barchinsky area are depleted todifferent degreeswithrespect to LREE and K yieldeda whole-rockisochron with an age of 509 ± 32 Ma, which suggests partial melting of these rocks duringthe exhumation stage.It was previously assumed that metasedimentary rocks of the Kokchetav microcontinent are the protoliths of diamondiferous rocks (Buslov et al., 2015). However, this contradicts with Sm-Nd isotopic data for metasedimentary rocks of quartzite-schist sequences of the Kokchetav microcontinent (Kovach et al., 2017). The metasedimentary rocks of the Sharyk Formation are characterized by variations in the ?Nd(t)from +4.1 to -3.3 and intNd(DM)from 1.9 to 1.25 Ga, whereasin the UHP metamorphic rocks ?Nd(t)varies from -7.6 to -13.2, and the model ages range from 2.7 to 2.3 Ga. These data clearly indicate that the metasedimentary rocks of the Kokchetav massif could not be the protolith of the ultrahigh-pressure rocks.
DS201910-2297
2019
Sobolev, N.Shatsky, V., Ragozin, A., Logvinova, A., Wirth, R., Sobolev, N.Alluvial diamonds from iron-saturated mantle beneath the northeastern margin of Siberian craton.Goldschmidt2019, 1p. AbstractRussiacraton

Abstract: Diamonds of eclogitic paragenesis are dominant in the placer deposits in the northeastern part of the Siberian Craton. Multiple inclusions and host diamonds carbon isotopes composition are consistent with a mixing model in which they result from the interaction of slab-derived melt/fluid with surrounding mantle [1,2]. A significant portion of diamonds contains black inclusions usually interpreted as graphite or sulphides. Twenty six dark inclusions from the 22 diamonds were exposed by polishing for chemical microanalysis. Inclusions were studied with SEM, TEM and EMP. Fe-C-O melt inclusions in association with with Kfsp, Ol and silicate melt inclusions were identified. Most of the inclusions are heterogeneous in composition and consist of iron carbides, iron in various oxidation states and carbon. Carbides contain impurities of Ni (0-0.6%), Sr (up to 3.4%), Cr (up to 0.8%) Si (up to 1%). Inclusions of wustite and Fe-Ti-O melt were identified in one diamond along with inclusions of Fe-C-O melt. In two cases diamond inclusions found within host diamond crystal. Diamond inclusions are surronded by a border consisting of wustite and siderite. Inclusions of Fe-C-O melt in allivial diamonds are best explained by carbonate melt-iron reaction [3].
DS2002-1581
2002
Sobolev, N..V.Taylor, L.A., Sobolev, N..V., Ghazi, M., Anand, M., Bodner, R.J.The science of diamonds and their inclusions can such dat a be used to establish diamond provenance?Eos, American Geophysical Union, Spring Abstract Volume, Vol.83,19, 1p.BrazilDiamond - inclusions, sulphides
DS1960-0601
1965
Sobolev, N.S.Sobolev, N.S., Kuznetsova, I.K.More Facts on the Mineralogy of Eclogite from Yakutian Kimberlite.Doklady Academy of Science USSR, Earth Science Section., Vol. 163, No. 1-6, PP. 137-140.RussiaBlank
DS1960-0449
1964
Sobolev, N.V.Firsov, L.V., Sobolev, N.V.The Absolute Age of a Xenolith of Eclogite from the Obnazhennaya Kimberlite Pipe.Geologii i Geofiziki, No. 10, PP. 74-77.RussiaBlank
DS1960-0499
1964
Sobolev, N.V.Sobolev, N.V.An Eclogite With RubyDoklady Academy of Sciences AKAD. NAUK SSSR., Vol. 157, PP. 1382-1384.RussiaDiamond Morphology, Inclusion
DS1960-0500
1964
Sobolev, N.V.Sobolev, V.S., Sobolev, N.V.Xenoliths in the Kimberlites of Northern Yakutia. and Problems of the Structure of the Earth's Mantle.Doklady Academy of Science USSR, Earth Science Section., Vol. 158, PP. L08-LLL.RussiaBlank
DS1960-0602
1965
Sobolev, N.V.Sobolev, N.V., Kuznetsova, I.K.New Dat a on the Mineralogy of Eclogites from the Yakutian Kimberlite Pipes.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 163, PP. 471-474.RussiaBlank
DS1960-0603
1965
Sobolev, N.V.Sobolev, N.V., Kuznetsova, I.K.New Dat a on the Mineralogy of Eclogites from the Yakutiann kimberlite Pipes.Doklady Academy of Sciences Nauk SSSR., Vol. 163, PP. 471-474.RussiaBlank
DS1960-0604
1965
Sobolev, N.V.Sobolev, V.S., Sobolev, N.V.Xenoliths in Kimberlite of Northern Yakutia and the Structure of the Mantle.Doklady Academy of Science USSR, Earth Science Section., Vol. 158, No. 1-6, PP. 22-25.RussiaBlank
DS1960-0747
1966
Sobolev, N.V.Sobolev, N.V., Kuznetsova, I.K.Mineralogy of Diamond Bearing EclogitesDoklady Academy of Sciences AKAD. NAUK SSSR., Vol. 167, No. 6, PP. 1365-1368.RussiaMineralogy
DS1960-0878
1967
Sobolev, N.V.Sobolev, N.V., Vakhrushev, V.A.Sulfides in Pyrope Peridotites in Kimberlites from YakutiaZap. Vses. Miner. Obshch., PT. 96, No. 4, P. 450.RussiaBlank
DS1960-0879
1967
Sobolev, N.V.Sobolev, V.S., Sobolev, N.V.Chromium and Chromium Bearing Minerals in Deep- Seated Xenoliths from Kimberlite Pipes.Geol. Rudn. Mestorozh., No. 9, PT. 2, PP. 10-16.RussiaBlank
DS1960-1029
1968
Sobolev, N.V.Sobolev, N.V.The Xenoliths of Eclogites from the Kimberlite Pipes of Yakutia As Fragments of the Upper Mantle Substance.International Geological Congress 23RD., Vol. 1, PP. 155-163.RussiaBlank
DS1960-1030
1968
Sobolev, N.V.Sobolev, N.V.Eklogit Xenoliths in den Kimberlite pipes von YakutienChem. Erde., Vol. 27, No. 2, PP. 164-177.RussiaBlank
DS1960-1031
1968
Sobolev, N.V.Sobolev, N.V.Eclogite Clinopyroxenes from the Kimberlite Pipes of YakutiaLithos, Vol. 1, PP. 54-57.Russia, YakutiaRelated Rocks, Classification
DS1960-1032
1968
Sobolev, N.V.Sobolev, N.V., Kuznetsova, I.K., Zyuzin, N.I.The Petrology of Grospydite Xenoliths from the Zagadochnaya kimberlite Pipe in Yakutia.Journal of Petrology, Vol. 9, PP. 253-280.RussiaBlank
DS1960-1212
1969
Sobolev, N.V.Sobolev, N.V., Lavrentyev, YU. G.Chrome Pyropes from Yakutian DiamondsDoklady Academy of Sciences AKAD. NAUK SSSR., Vol. 189, PP. 162-165.RussiaInclusions, Diamond Morphology
DS1970-0193
1970
Sobolev, N.V.Sobolev, N.V.Eclogites and Pyrope Peridotites from the Kimberlites of Yakutia.Phys. Earth Planetary Interiors, Vol. 3, PP. 398-404.RussiaBlank
DS1970-0421
1971
Sobolev, N.V.Sobolev, N.V.Some Specific Features of Distribution and Transportation Of Xenoliths in the Kimberlite Pipes of Yakutia.Journal of Geophysical Research, Vol. 76, PP. 1309-1314.RussiaBlank
DS1970-0439
1971
Sobolev, N.V.Vakhrushev, V.A., Sobolev, N.V.Sulfidic Formations in Deep Xenoliths from Kimberlites in Yakutia.International Geology Review, Vol. 15, No. 1, PP. 103-110.RussiaBlank
DS1970-0543
1972
Sobolev, N.V.Kharkiv, A.D., Sobolev, N.V., Chumirin, K.G.Inclusions of Chromium Diopside in Zircon from the Kimberlite rocks of the Malaya Botubuya Region.Zap. Vses. Miner, Obschch., Vol. 101, No. 6, PP. 431-433.RussiaPetrography
DS1970-0602
1972
Sobolev, N.V.Sobolev, N.V., et al.Crystalline Inclusions With Octahedral Faces in DiamondsDoklady Academy of Science USSR, Earth Science Section., Vol. 204, No. 1-6, PP. 117-120.RussiaKimberlite
DS1970-0603
1972
Sobolev, N.V.Sobolev, V.S., Sobolev, N.V., Lavrentyev, YU.G.Inclusions in Diamond from a Diamond Bearing EclogiteDoklady Academy of Sciences AKAD. NAUK SSSR., Vol. 207, PP. 164-167.RussiaDiamond Morphology
DS1970-0829
1973
Sobolev, N.V.Sobolev, N.V., Lavrentev, Y.G., Pokhilenko, N.P. USOVA.Chrome Rich Garnets from Kimberlites of Yakutia and their ParagenesesContributions to Mineralogy and Petrology, Vol. 40, pp. 39-52.Russia, YakutiaMineralogy - Garnets
DS1975-0089
1975
Sobolev, N.V.Green, D.H., Sobolev, N.V.Coexisting Garnets and Ilmenites Synthesized at High Pressure pressures from Pyrolite and Olivine Basanite and Their Significance for Kimberlitic Assemblages.Contributions to Mineralogy and Petrology, Vol. 50, PP. 217-229.South AfricaWesselton, Microprobe Analyses
DS1975-1229
1979
Sobolev, N.V.Sobolev, N.V.Deep Seated Inclusions in Kimberlites and the Problem of The Composition of the Upper Mantle.American Geophysical Union., 279P.RussiaKimberley, Diamond Morphology
DS1975-1230
1979
Sobolev, N.V.Sobolev, N.V.Deep seated Inclusions in Kimberlites and the Problem of The composition of the Upper Mantle.Washington: American Geophysical Union (agu), 279P.RussiaKimberlite, Kimberley, Janlib
DS1980-0320
1980
Sobolev, N.V.Sobolev, N.V.Significance of Picroilmenite for Locating Kimberlite FieldsSoviet Geology And Geophysics, Vol. 21, No. 10, PP. 127-128.RussiaBlank
DS1981-0386
1981
Sobolev, N.V.Sobolev, N.V.What the Siberian Diamonds Tell United StatesIndiaqua., Vol. 30, No. 3, PP. 11-13.RussiaKimberlite
DS1981-0387
1981
Sobolev, N.V.Sobolev, N.V., Efimova, E.S., Pospelova, L.N.Native Iron in Diamonds of Yakutiya and Its ParagenesisSoviet Geology And Geophysics, Vol. 22, No. 12, PP. 18-21.RussiaKimberlite, Inclusion, Crystallography
DS1981-0388
1981
Sobolev, N.V.Sobolev, V.S., Sobolev, N.V.Yakut Diamonds: Scientific Problems Connected with Their Study.Journal of GEMMOLOGICAL SOCIETY of JAPAN., Vol. 8, No. 1-8, PP.RussiaBlank
DS1982-0169
1982
Sobolev, N.V.Davis, G.L., Sobolev, N.V., Khar'kiv, A.D.New Dat a on the Age of Yakutian Kimberlites Obtained by The uranium Lead Method on Zircons.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 254, No. 1, PP. 53-57.Russia, YakutiaPipes, Geochronology
DS1982-0396
1982
Sobolev, N.V.Marie, A.M., Mainprice, D.H., Sobolev, N.V.A Transmission Electron Microscopy Study of Olivine Inclusions in Diamond.Proceedings of Third International Kimberlite Conference, TERRA COGNITA, ABSTRACT VOLUME., Vol. 2, No. 3, P. 200, (abstract.).RussiaKimberlite, Udachnaya
DS1982-0500
1982
Sobolev, N.V.Pokhilenko, N.P., Sobolev, N.V., Efimova, E.S.Xenolith of Cataclazed Diamond Bearing Disthenic Eclogite from the Pipe 'udachnaia' Yakutia.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 266, No. 1, PP. 212-216.RussiaBlank
DS1982-0502
1982
Sobolev, N.V.Ponomarenko, A.I., Spetsius, Z.V., Sobolev, N.V.New Type of Diamond Bearing Rock- Garnet PyroxeniteDoklady Academy of Science USSR, Earth Science Section., Vol. 251, No. 2, PP. 89-91.RussiaPetrography
DS1983-0354
1983
Sobolev, N.V.Kharkiv, A.D., Pokhilenko, N.P., Sobolev, N.V.Large Xenoliths of Cataclased Lherzolites from the Udachnaya Kimberlite Pipe of Yakutia.Soviet Geology And Geophysics, Vol. 24, No. 1, PP. 67-72.RussiaMineralogy
DS1983-0569
1983
Sobolev, N.V.Shatskiy, V.S., Sobolev, N.V., Pavlyuchenko, V.S.Xenoliths of rocks with fassaite garnet anorthite in Udachnaya kimberliticpipe, Yakutia.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 272, No. 1, pp. 188-192RussiaBlank
DS1983-0641
1983
Sobolev, N.V.Yefimova, E.S., Sobolev, N.V., Pospelova, L.N.Sulfide Inclusions in Diamonds and their Paragenesis.(russian)Zap. Vses Mineral. Obshch., (Russian), Vol. 112, No. 3, pp. 300-310RussiaInclusions, Diamond Morphology
DS1984-0001
1984
Sobolev, N.V.Afanasev, V.P., Sobolev, N.V., Kharkiv, A.D.The Evolution of the Chemical Composition of Pyrope Associations in Old Dispersion Halos Around Kimberlite Bodies.Soviet Geology And Geophysics, Vol. 25, No. 2, PP. 130-135.RussiaGeochemistry
DS1984-0129
1984
Sobolev, N.V.Bakumenko, I.T., Sobolev, N.V., Khokhriakov, A.F., Chepurov, A.Faceted Inclusions in Diamond CrystalsDoklady Academy of Sciences AKAD. NAUK SSSR., Vol. 278, No. 6, PP. 1461-1465.RussiaDiamond Morphology
DS1984-0591
1984
Sobolev, N.V.Pokhilenko, N.P., Sobolev, N.V., Yefimova, YE.S.Xenolith of Broken Down Diamond Bearing Kyanite Eclogite From the Udachnaya Pipe, Yakutia.Doklady Academy of Science USSR, Earth Science Section., Vol. 266, No. 1-6, MAY PP. 90-94.Russia, YakutiaLherzolite, Geothermometry, Genesis, Diamond Morphology
DS1984-0613
1984
Sobolev, N.V.Rodionov, A.S., Pokhilenko, N.P., Sobolev, N.V.Comparative Description of Major Minerals of the Concentrate of the Two Varieties of Kimberlite of the Dalnyi Pipe of Yakutia.Soviet Geology And Geophysics, Vol. 25, No. 5, PP. 33-44.Russia, YakutiaMineralogy
DS1984-0688
1984
Sobolev, N.V.Sobolev, N.V.Crystalline Inclusions in Diamonds from New South Wales, Australia. #1University of Western Australia - Special Publication, No. 8, PP. 213-226AustraliaBlank
DS1984-0689
1984
Sobolev, N.V.Sobolev, N.V.Crystalline Inclusions in Diamonds from New South Wales, Australia. #2Kimberlite Occurrence And Origin A Basis For Conceptual Mode, P. 23. (abstract.)Australia, New South Wales, CopetonInverell, Mineralogy, Natural, Diamonds, Morphology, Mineral Chemistry
DS1984-0690
1984
Sobolev, N.V.Sobolev, N.V.Kimberlites of the Siberian Platform Their Geological and Mineralogical Features.Kimberlite Occurrence And Origin A Basis For Conceptual Mode, PP. 27-28. (abstract.)Russia, YakutiaGeology, Classification, Distribution, Mineralogy, Geochronology
DS1984-0691
1984
Sobolev, N.V.Sobolev, N.V.Kimberlites of the Siberian Platform: Their Geological and Mineralogical Features.University of Western Australia - Special Publication, No. 8, PP. 275-289.Russia, Siberia, YakutiaAge, Mineralogy, Paragenesis, Pyrope, Spinel, Picroilmenite
DS1984-0692
1984
Sobolev, N.V.Sobolev, N.V., Efimova, E.S., Lavrentiev, I.G., Sobolev, V.S.Predominating Calc-silicate Association of Crystalline Inclusions in Diamonds from the South Australia Placers.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 274, No. 1, PP. 172-179.Australia, South AustraliaAlluvial Diamond Deposits, Mineralogy
DS1984-0693
1984
Sobolev, N.V.Sobolev, N.V., Pokhilenko, N.P., Efimova, E.S.Diamond Bearing Peridotite Xenoliths in Kimberlites and The problem of the Origin of Diamonds.Soviet Geology And Geophysics, Vol. 25, No. 12, PP. 62-76.RussiaGenesis
DS1984-0694
1984
Sobolev, N.V.Sobolev, N.V., Pokhilenko, N.P., Efimova, E.S.Xenoliths of Diamond Bearing Peridotites in Kimberlites And the Problem of Diamonds Origin.Geologii i Geofiziki, No. 12, (300) DECEMBER PP. 63-RussiaGenesis, Petrography
DS1984-0695
1984
Sobolev, N.V.Sobolev, N.V., Yefimova, E.S.Dominant calcsilicate association of crystalline inclusions in placer diamonds from southeastern AustraliaDoklady Academy of Science USSR, Earth Science Section, Vol. 274, Jan-Feb. pp. 148-152Australia, InverellPlacers, Inclusions
DS1985-0323
1985
Sobolev, N.V.Kaminskiy, F.V., Sobolev, N.V.The carbon isotopic composition variations within diamondcrystals.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 285, No. 6, pp. 1436-1438RussiaDiamond Morphology
DS1985-0552
1985
Sobolev, N.V.Radionov, A.S., Sobolev, N.V.A New Find of Graphite Containing Harzburgite Xenoliths Inkimberlite.(russian)Geol. Geofiz., (Russian), No. 12, pp. 32-37RussiaHarzburgite
DS1985-0568
1985
Sobolev, N.V.Rodionov, A.S., Sobolev, N.V.A New Find of Xenolith of Graphite Bearing Harzburgite in KimberliteSoviet Geology and Geophysics, Vol. 26, No. 12, December pp. 26-32RussiaXenolith, Petrology
DS1985-0608
1985
Sobolev, N.V.Shatskiy, V.S., Sobolev, N.V.Pyroxene-plagioclase Symplektites in Eclogites of the Kokchetav MassifSoviet Geology and Geophysics, Vol. 26, No. 9, pp. 76-81RussiaEclogite
DS1985-0609
1985
Sobolev, N.V.Shatskiy, V.S., Sobolev, N.V., Pavlyuchenko, V.S.Fassaite Garnet Anorthite Xenolith from the Udchanaya Kimberlite Pipe, Yakutia.Doklady Academy of Science USSR, Earth Science Section., Vol. 272, No. 1-6, MARCH PP. 137-140.Russia, YakutiaPetrography
DS1985-0634
1985
Sobolev, N.V.Sobolev, A.V., Sobolev, N.V., Smit, K.B.New Dat a on the Petrology of Olivine Lamproites of Western Australia Based on Results of the Investigation of Magmatic Inclusions in Olivines.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 284, No. 1, PP. 196-Australia, Western AustraliaLamproite, Petrology
DS1985-0635
1985
Sobolev, N.V.Sobolev, A.V., Sobolev, N.V., Smit, K.B., Kononkova, N.N.New dat a on the petrology of olivine lamproites of Western australia From the results of the investigation of magmatic inclusions in olivines.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 284, No. 1, pp. 196-201AustraliaLamproite, Inclusions
DS1985-0636
1985
Sobolev, N.V.Sobolev, N.V., Yefimova, E.S., Lavrentyev, YU.G., Sobolev, V.S.Dominant calc-silicate association of crystalline inclusions in placer diamonds from southeastern AustraliaDoklady Academy of Science USSR, Earth Science Section, Vol. 275, April pp. 148-152AustraliaNew South Wales, Diamond Morphology
DS1986-0029
1986
Sobolev, N.V.Arseniev, T.A., Zilbertski, A.K., Sobolev, N.V.The estimation of pressure experiences by crystals of olivinefromkimberlites.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 286, No. 5, pp. 1220-1223RussiaPetrology
DS1986-0030
1986
Sobolev, N.V.Arsenyeva, T.A., Zilbershteyn, A.K., Sobolev, N.V.Evaluation of experimental pressure on olivine crystals inkimberlites.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR., (Russian), Vol. 286, No. 5, pp. 1220-1223RussiaExperimental Petrology
DS1986-0042
1986
Sobolev, N.V.Bakumenko, I.T., Sobolev, N.V., Khokryakov, A.F., Chepurov, A.I.Faceted inclusions in diamond crystalsDoklady Academy of Science USSR, Earth Science Section, Vol. 278, No. 1-6, pp. 168-170RussiaDiamond morphology, Inclusions
DS1986-0506
1986
Sobolev, N.V.Lucas, H., Ramsay, R., Hall, A.E., Smith, C.B., Sobolev, N.V.Garnets from West Australian kimberlites and associated rocksProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 270-272AustraliaBlank
DS1986-0647
1986
Sobolev, N.V.Pokhilenko, N.P., Sobolev, N.V.Xenoliths of Diamondiferous peridotites from Udachnaya kimberlite pipe, YakutiaProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 309-310RussiaBlank
DS1986-0690
1986
Sobolev, N.V.Ryabchikov, I.D., Solovova, I.P., Sobolev, N.V., Sobolev, A.V.Nitrogen in lamproitic magmas.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 288, No. 4, pp. 976-979RussiaLamproite
DS1986-0762
1986
Sobolev, N.V.Sobolev, A.V., Sobolev, N.V., Smith, C.B., Dubessy, J.Pecularities in the fluid and melt compositions of the lamproites And kimberlites based on the study of inclusions inolivinesProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 93-94Australia, Russia, ArkansasLamproite
DS1986-0763
1986
Sobolev, N.V.Sobolev, N.V.The geology of upper Paleozoic diamond bearing deposits of the Tunguskasynclise.(Russian)Trudy Institute Geologii i Geofiziki, (Russian), Vol. 646, 192pRussiaDeposits, Diamond
DS1986-0764
1986
Sobolev, N.V.Sobolev, N.V., Kharkiv, A.D., et al.Garnet crystals with diamond inclusions from kimberlites of the pipe IMXXIII Svezd. KPSS, Yakutia.(Russian)Mineral. Zhurn., (Russian), Vol. 8, No. 2, pp. 23-31RussiaDiamond morphology
DS1986-0765
1986
Sobolev, N.V.Sobolev, N.V., Kharkiv, A.D., Pkhilenko, N.P.Kimberlites, lamproites and the problem of upper mantlecomposition.(Russian)Geol. Geofiz., (Russian), No. 7, pp. 18-29RussiaLamproites
DS1986-0766
1986
Sobolev, N.V.Sobolev, N.V., Kharkiv, A.D., Pokhilenko, N.P.Kimberlites, lamproites and the composition of the upper mantleSoviet Geology and Geophysics, Vol. 27, No. 7, pp. 10-18RussiaKimberlite, Lamproite
DS1986-0767
1986
Sobolev, N.V.Sobolev, N.V., Pokhilenko, N.P., Carswell, D.A., Rodionov, A.S.Sheared lherzolites from kimberlites of YakutiaProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 338-339RussiaBlank
DS1986-0768
1986
Sobolev, N.V.Sobolev, N.V., Sobolev, E.V., Yefimova, E.S.Some physical and chemical characteristics of diamonds from Copeton New south Wales. Reference to Proceedings 20th.International Gemmological Conference ptThe Australian Gemologist, Vol. 16, No. 3, p. 119. abstractAustraliaDiamond, Morphology
DS1986-0769
1986
Sobolev, N.V.Sobolev, N.V., Yefimova, E.S., Shermanina, E.I.Crystalline inclusions in alluvial diamonds from the Urals, USSRProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, p. 429RussiaDiamond inclusions
DS1986-0841
1986
Sobolev, N.V.Vishnevskii, S.A., Dolgov, Yu.A., Sobolev, N.V.Lamproites of the Talakhtakh diatreme on the eastern slope of the AnabarshieldSoviet Geology and Geophysics, Vol. 27, No. 8, pp. 15-24RussiaLamproite
DS1987-0016
1987
Sobolev, N.V.Arsenyeva, T.A., Zilbershteyn, A.Kh., Sobolev, N.V.Determination of the hydrostatic pressure experienced at depth by olivine crystals from kimberliteDokl. Acad. Sciences USSR Earth Science Section, Vol. 286, No. 1-6, September pp. 143-146RussiaBlank
DS1987-0329
1987
Sobolev, N.V.Kaminskiy, F.V., Sobolev, N.V.Variations of the isotope distribution within diamond crystalsDoklady Academy of Science USSR, Earth Science Section, Vol. 285, No. 6, pp. 155-157RussiaBlank
DS1987-0557
1987
Sobolev, N.V.Osorgin, N.Yu., Palyanov, Yu.N., Sobolev, N.V., et al.Fluid inclusions in diamond crystals.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol.l 293, No. 5, pp. 1214-1217RussiaDiamond morphology, Diamond inclusions
DS1987-0558
1987
Sobolev, N.V.Osorgin, N.Yu., Palyanov, Yu.N., Sobolev, N.V., Khokhryakova, I.P., et al.Inclusions of liquified gases in diamond crystals.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR (Russian), Vol. 293, No. 5, pp. 1214-1217RussiaGeochemistry, diamond
DS1987-0694
1987
Sobolev, N.V.Sobolev, A.V., Sobolev, N.V., Smith, C.B., Kononkova, N.N.New dat a on the petrology of the olivine lamproites of Western Australia revealed by the study of magmatic inclusions inolivineDoklady Academy of Science USSR, Earth Science Section, Vol. 284, No. 5, Publishing July 1987, pp. 106-110AustraliaLamproite, Petrology
DS1987-0695
1987
Sobolev, N.V.Sobolev, N.V.Mantle xenoliths and continental lithosphere compositionGeodynamic series in: composition, structure and dynamics of the, Vol. 16, pp. 161-164GlobalBlank
DS1987-0696
1987
Sobolev, N.V.Sobolev, N.V., Nixon, P.H.Xenoliths from the USSR and Mongolia: a selective and brief reviewin: Nixon, P.H. ed. Mantle xenoliths, J. Wiley, pp. 159-166RussiaBlank
DS1988-0528
1988
Sobolev, N.V.Osorgin, N.Yu., Palyanov, Yu. N., Sobolev, N.V., KhokhryakovaLiquified gas inclusions in diamond crystalsDoklady Academy of Science USSR, Earth Science Section, Vol. 293, No. 1-6, September pp. 150-153RussiaDiamond inclusions
DS1989-0393
1989
Sobolev, N.V.Efimova, E.S., Zakharchenko, O.D., Sobolev, N.V., Makhin, A.I.Inclusions in diamonds from a kimberlite pipe.(Russian)Zap. Vses. Mineral. O-Va, (Russian), Vol. 118, No. 2, pp. 74-76RussiaDiamond morphology, Diamond inclusions
DS1989-0462
1989
Sobolev, N.V.Galimov, E.M., Kaminskiy, F.V., Maltsev, K.A., Sobolev, N.V.Relation of carbon isotopic composition with parageneses of mineral inclusions in diamonds in paired kimberlite pipes.(Russian)Geochemistry International (Geokhimiya), (Russian), No. 5, pp. 754-758RussiaGeochronology - C Isotope, Diamond inclusions
DS1989-0463
1989
Sobolev, N.V.Galimov, E.M., Sobolev, N.V., Yefimova, E.S.Isotopic composition of carbon of diamond bearing mineral inclusions From the northern Urals placers.(Russian)Geochemistry International (Geokhimiya), (Russian), No. 9, pp. 1363-1370RussiaDiamond inclusions, Geochronology
DS1989-0696
1989
Sobolev, N.V.Jagoutz, E., Shatsky, V.S., Sobolev, N.V., Pokhilenko, N.P.lead-neodymium-Sr isotope study of the Kokchetav Massif;the outcrop of the lowerlithosphereDiamond Workshop, International Geological Congress, July 15-16th. editors, pp. 32-35. AbstractRussiaMantle, Geochronology
DS1989-0739
1989
Sobolev, N.V.Kadik, A.A., Sobolev, N.V., Zharkova, E.V., Pokhilenko, N.P.Redox conditions of formation of diamond bearing peridotite xenoliths from Udachnaya kimberlite pipe,Yakutia.(Russian)Geochemistry International (Geokhimiya), (Russian), No. 8, August pp. 1120-1135RussiaGeochemistry, Xenoliths - peridotite
DS1989-0901
1989
Sobolev, N.V.Lucas, H., Ramsay, R.R., Hall, A.E., Smith, C.B., Sobolev, N.V.Garnets from Western Australian kimberlites and related rocksGeological Society of Australia Inc. Blackwell Scientific Publishing, Special, No. 14, Vol. 2, pp. 809-819AustraliaLamproite, Heavy minerals, Geochemist
DS1989-1378
1989
Sobolev, N.V.Shatsky, V.S., Sobolev, N.V., Yefimova, E.S.Morphological features of accessory microdiamonds from metamorphic Rocks of the earth's crustDiamond Workshop, International Geological Congress, July 15-16th. editors, pp. 94-95. AbstractRussiaMicrodiamond, Metamorphic rocks
DS1989-1419
1989
Sobolev, N.V.Sobolev, A.V., Sobolev, N.V., Smith, C.B., Dubessy, J.Fluid and melt compositions in lamproites And kimberlites based on the study of inclusions inolivineGeological Society of Australia Inc. Blackwell Scientific Publishing, Special, No. 14, Vol. 1, pp. 220-240Australia, RussiaEllendale, Mt. Cedric, Udachnaya, Geochemistry
DS1989-1420
1989
Sobolev, N.V.Sobolev, N.V.Petrology of the upper mantle and the origin of diamonds; selectedworks.(Russian)Izd. Nauka Novosibirsk, (Russian), 234p.ISBN 5-02-028811 VN G5607 92-29554-B, ; 92-22604-B.RussiaMantle, Diamonds
DS1989-1421
1989
Sobolev, N.V.Sobolev, N.V.Significance of diamonds in metamorphic rocksDiamond Workshop, International Geological Congress, July 15-16th. editors, p. 117RussiaMetamorphic rocks, Microdiamonds
DS1989-1422
1989
Sobolev, N.V.Sobolev, N.V., Galimov, E.M., Smith, C.B., Yefimova, E.S., MaltsevA comp study of the morphology, inclusions and C I composition of diamondsSoviet Geology and Geophysics, Vol. 30, No. 12, pp. 1-19AustraliaMicrodiamonds, Alluvial diamonds
DS1989-1423
1989
Sobolev, N.V.Sobolev, N.V., Shatskii, V.S., Kholdeev, O.V.Erroneous identification of diamonds in garnets from slightly gneissosedgranites.Comments.(Russian)Geol. Geofiz. (Russian), No. 7, pp. 129-130RussiaDiamond inclusions, Granites
DS1989-1424
1989
Sobolev, N.V.Sobolev, N.V., Shatskii, V.S., Kholdeev, O.V.Mistaken identification of diamond crystals in garnets from slightly gneissic granites( in connection with the publications of V.K. Garanin et al.)Soviet Geology and Geophysics, Vol. 30, No. 7, pp. 120-124RussiaDiamond morphology, Granites
DS1989-1425
1989
Sobolev, N.V.Sobolev, N.V., Shvedanko, G.I., et al.Nitrogen in chromites and olivines coexisting with diamonds.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 309, No. 3, pp. 697-700RussiaDiamond inclusions, Nitrogen-chromites/olivin
DS1989-1426
1989
Sobolev, N.V.Sobolev, N.V., Sobolev, A.V., Pokhilenko, N.P., Yefimova, E.S.Chrome spinels coexisting with Yakutian diamondsDiamond Workshop, International Geological Congress, July 15-16th. editors, pp. 105-108. AbstractRussiaMineral chemistry, Chrome spinels
DS1990-0506
1990
Sobolev, N.V.Galimov, E.M., Kaminisky, F.V., Maltsev, K.A., Sobolev, N.V.The relation between delta 13 C and mineral inclusion assemblages in diamonds from paired kimberlite pipesGeochemistry International, Vol. 26, No. 12, pp. 134-137RussiaDiamond inclusions, carbon, Delta 13 C analyses
DS1990-0508
1990
Sobolev, N.V.Galimov, E.M., Sobolev, N.V., Yefimova, E.S., Shemanina, Ye.I.Carbon isotope composition of inclusion bearing diamonds from north UralplacersGeochemistry Int, Vol. 27, No. 4, pp. 131-138RussiaGeochronology CI, Placers
DS1990-0752
1990
Sobolev, N.V.Jagoutz, E., Shatsky, V.S., Sobolev, N.V.Sr-Neodymium-Palladium isotopic study of ultra high pressuret rocks from Kokchetav massifEos, Vol. 71, No. 43, October 23, p. 1707 AbstractRussiaMetamorphic rocks, Diamonds
DS1990-0793
1990
Sobolev, N.V.Kadik, A.A., Sobolev, N.V., Zharkova, Ye.V., Pokhilenko, N.P.Redox conditions of formation of diamond bearing peridotite xenoliths In the Udachnaya kimberlite pipe, YakutiaGeochemistry Int, Vol. 27, No. 4, pp. 41-54RussiaRedox Udachnaya, Peridotite
DS1990-1341
1990
Sobolev, N.V.Shatskii, V.S., Jagoutz, E., Sobolev, N.V., Kozmenko, O.A.Geochemical characteristics of crustal rocks subducted into the uppermantleEos, Vol. 71, No. 43, October 23, p. 1707 AbstractRussiaMetamorphic rocks, Diamonds
DS1990-1386
1990
Sobolev, N.V.Sobolev, N.V., Abouassaleh, K., Kepezhinskas, K.B., ledneva, V.P.Lamprophyres of Cretaceous diatremes of the Syrian rift.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 314, No. 2, pp. 435-439SyriaLamprophyres, Diatremes
DS1990-1387
1990
Sobolev, N.V.Sobolev, N.V., Mankenda, A., Kaminsky, F.V., Sobolev, V.N.Garnets from kimberlites of north-east Angola and relation of Their composition with diamond content.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 315, No. 5, pp. 1225-1229AngolaGarnets and diamonds, Mineralogy
DS1990-1388
1990
Sobolev, N.V.Sobolev, N.V., Shatskii, V.S., Vavilov, M.A.Mineralogical indicators of ultrahigh pressure metamorphism in eclogite bearing complex of Kokchetav Massif, USSRInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 2, extended abstract p. 890-891RussiaEclogite, Mineralogy -inclusions
DS1990-1389
1990
Sobolev, N.V.Sobolev, N.V., Shatskii, V.S., Vavilov, M.A.Ultra high pressure mineral assemblages of inclusions in garnets, zircon sand clinopyroxenes from Diamondiferous metamorphic rocks, northern Kazakhstan, USSREos, Vol. 71, No. 43, October 23, p. 1707 AbstractRussiaMetamorphic rocks, Diamonds
DS1990-1390
1990
Sobolev, N.V.Sobolev, N.V., Shatsky, V.S.Diamond inclusions in garnet from metamorphic rocks: a new environment for diamond formationNature, Vol. 343, No. 6160, February 22, pp. 742-746RussiaDiamond inclusions, Garnet analyses -Metamorp
DS1991-0003
1991
Sobolev, N.V.Afanasev, V.P., Sobolev, N.V., Pokhilenko, N.P.Exogenous changes of the indicator minerals at the formation of mineralogical halos of kimberlite bodiesProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 1-2RussiaAlluvial, Diamonds -mineralogy
DS1991-0272
1991
Sobolev, N.V.Claoue-Long, J.C., Sobolev, N.V., Shatsky, V.S., Sobolev, A.V.Zircon response to diamond -pressure metamorphism in the Kokchetav USSRGeology, Vol. 19, No. 7, July pp. 710-713RussiaMicroprobe-SHRIMP, Geochronology -age populations
DS1991-0607
1991
Sobolev, N.V.Griffin, W.L., Gurney, J.J., Sobolev, N.V., Ryan, C.G.Comparative geochemical evolution of cratonic lithosphere: South Africa andSiberiaProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 119-121South Africa, RussiaGeochemistry, Craton, mineralogy
DS1991-0610
1991
Sobolev, N.V.Griffin, W.L., Ryan, C.G., Gurney, J.J., Sobolev, N.V., Win, T.T.Chromite macrocrysts in kimberlites and lamproites: geochemistry and origin #1Proceedings of Fifth International Kimberlite Conference held Araxa June, pp. 142-144South Africa, RussiaGeochemistry -chrome-spinels, Mantle, exploration
DS1991-0636
1991
Sobolev, N.V.Gurney, J.J., Moore, R.O., Griffin, W.L., Sobolev, N.V.The use of macrocryst minerals to predict diamond potential in kimberlites based on Southern Africa and a comparison with SiberiaGeological Society The Canadian Institute of Mining, Metallurgy and Petroleum (CIM) First Annual Field Conference symposium held, 2pg. abstractSouth Africa, RussiaDiamond potential, Garnet, nickel thermometry
DS1991-0777
1991
Sobolev, N.V.Jacob, D., Jagoutz, E., Sobolev, N.V.A diamond graphite bearing eclogitic xenolith from Roberts Victor-indication for petrogenesis from lead, neodymium, and Sr isotopesProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 190-192South AfricaGeochronology, Geochemistry
DS1991-0794
1991
Sobolev, N.V.Jerde, E.A., Taylor, L.A., Sobolev, N.V., Crozaz, G.Rare earth elements in Diamondiferous eclogites from Yakutia, Siberia:evidence for source region variabilityEos Transactions, Vol. 72, No. 44, October 29, abstract p. 517Russia, Yakutia, SiberiaEclogites, rare earth elements (REE).
DS1991-1007
1991
Sobolev, N.V.Logvinova, A.M., Sobolev, N.V.Crystalline inclusions in chromites from kimberlites and lamproitesProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, p. 240Russia, AustraliaYakutia, Udachnaya, Aikhal, Mir, International, Ellendale, Olivine inclusions
DS1991-1360
1991
Sobolev, N.V.Pokhilenko, N.P., Pearson, D.G., Boyd, F.R., Sobolev, N.V.Megacrystalline dunites and peridotites: hosts for Siberian diamondsCarnegie Institute Annual Report of the Director Geophysical Laboratory, No. 2250, pp. 11-18Russia, SiberiaDunites, Peridotites
DS1991-1446
1991
Sobolev, N.V.Rodionov, A.S., Sobolev, N.V., Pokhilenko, N.P., Suddaby, P.Ilmenite-bearing peridotites and megacrysts from Dalnaya kimberlite pipe, YakutiaProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 339-341RussiaMineral chemistry, ilmenite-pyrope lherzolite, Ilmenite-pyrope wehrlites, Metasomatism
DS1991-1560
1991
Sobolev, N.V.Shatskiy, V.S., Sobolev, N.V., Zayachkov, A.A., Zorin, Y.M.A new manifestation of micro-diamonds in metamorphic rocks as an evidence of the regional character of high-pressure metamorphism in KokchetavMassif.(in Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 321, No. 1, pp. 189-193. # HB124RussiaMicrodiamonds, Metamorphic rocks
DS1991-1561
1991
Sobolev, N.V.Shatsky, V.S., Sobolev, N.V., Zayachkovsky, A.A., Zorin, Y.M., Vavtlov, M.A.New occurrence of microdiamonds in metamorphic rocks as a proof forDoklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 321, pp. 189-193.Russia, Commonwealth of Independent States (CIS)Microdiamonds, Metamorphic rocks
DS1991-1622
1991
Sobolev, N.V.Sobolev, N.V.Specific features of diamonds associated with minerals from new Arkhangelsk Diamondiferous kimberlite province, USSRXiii International Gemmological Conference Held South Africa, Stellenbosch, 2p.abstractRussia, ArkangelskDiamond mineralogy, New Arkhangelsk
DS1991-1623
1991
Sobolev, N.V.Sobolev, N.V., Bakumenko, I.T., Yefimova, E.S., Pokhilenko, N.P.Morphological features of microdiamonds, sodium in garnet and potassium inpyroxenes content of two eclogite xenoliths from Udachnaya pipe(Yakutia).(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 321, No. 3, pp. 585-592Russia, Commonwealth of Independent States (CIS), YakutiaMicrodiamonds, Udachanya pipe
DS1991-1624
1991
Sobolev, N.V.Sobolev, N.V., Bakumenko, I.T., Yefimova, E.S., Pokhilenko, N.P.Pecularities of microdiamond morphology, sodium content in garnets andDoklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 321, No. 3, pp. 585-592. #hh968RussiaMicro-diamonds, Geochemistry
DS1991-1625
1991
Sobolev, N.V.Sobolev, N.V., Shatskiy, V.S., Vavilov, M.A., Goryainov, S.V.Coesite inclusion in zircon from diamond containing gneisses of KokchetavMassif- lst find of coesite in metamorphic rocks of the USSR. (Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 321, No. 1, pp. 184-188. # hb124RussiaCoesite, Metamorphic rocks
DS1991-1626
1991
Sobolev, N.V.Sobolev, N.V., Shvedenkov, G.Yu., Korolyuk, V.S., Yefimova, E.S.Nitrogen in chromites and olivines coexisting with diamondDoklady Academy of Science USSR, Earth Science Section, Vol. 309, No. 1-6, July pp. 193-195RussiaNatural diamond, Nitrogen
DS1991-1627
1991
Sobolev, N.V.Sobolev, N.V., Zuev, V.M., Bezborodov, S.M., Ponomarenko, A.I.Eclogite paragenesis of diamonds from Udachnaya and Mir pipes, YakutiaProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, p. 391RussiaXenoliths, Omphacites
DS1991-1784
1991
Sobolev, N.V.Vavilov, M.A., Sobolev, N.V., Shatskii, V.S.Micas from diamond bearing metamorphic rocks of northern Kazakhstan.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 319, No. 2, pp. 466-470Russia, KazakhstanMetamorphic rocks, Diamonds
DS1992-0485
1992
Sobolev, N.V.Fraracci, K.N., Taylor, L.A., Sobolev, N.V., Sobolev, V.N.Mineral chemistry of Diamondiferous eclogite xenoliths from the Mirkimberlite of the Yakutian kimberlite province, SiberiaGeological Society of America (GSA) Abstracts with programs, 1992 Annual, Vol. 24, No. 7, abstract p. A260Russia, Yakutia, SiberiaEclogites, Diamonds
DS1992-0618
1992
Sobolev, N.V.Griffin, W.L., Ryan, C.G., Gurney, J.J., Sobolev, N.V.Comparative geochemical evolution of the Australian, southern Africa and Siberian cratonic lithosphere11th. Australian Geol. Convention Held Ballarat University College, Jan., AbstractAustralia, South Africa, RussiaCraton, Geochemistry
DS1992-0619
1992
Sobolev, N.V.Griffin, W.L., Ryan, C.G., Gurney, J.J., Sobolev, N.V.Comparative geochemical evolution of the southern African, Siberian and Australian cratonic lithosphereProceedings of the 29th International Geological Congress. Held Japan August 1992, Vol. 1, abstract p. 175South Africa, Russia, AustraliaGeochronology, Craton
DS1992-0786
1992
Sobolev, N.V.Jerde, E.A., Taylor, L.A., Crozaz, G., Sobolev, N.V., Sobolev, V.N.Diamondiferous eclogites from Yakutia Siberia: rare earth element evidence for a range of crustal protolithsGeological Society of America (GSA) Abstracts with programs, 1992 Annual, Vol. 24, No. 7, abstract p. A260Russia, YakutiaEclogites, Diamonds
DS1992-0787
1992
Sobolev, N.V.Jerde, E.A., Taylor, L.A., Sobolev, N.V., Crozaz, C.Diamondiferous eclogites from Yakutia, Siberia: comparison with Kaapvaal craton and rare earth element evidence for source region variabilityProceedings of the 29th International Geological Congress. Held Japan August 1992, Vol. 1, abstract p. 179Russia, Yakutia, southern AfricaEclogites, rare earth elements (REE).
DS1992-1445
1992
Sobolev, N.V.Sobolev, N.V., et al.Inclusion of diamonds, coesite and coexisting minerals in zircons and garnets from metamorphic rocks of Kochetav Massif, Northern Kazakstan, USSRProceedings of the 29th International Geological Congress. Held Japan August 1992, Vol. 2, abstract p. 599Russia, KazakhstanDiamond inclusions, Metamorphic rocks
DS1992-1446
1992
Sobolev, N.V.Sobolev, N.V., Afanasev, V.P., Pokhilenko, N.P., Kaminsky, F.V.Pyropes and diamonds of the Algerian Sahara.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 325, No. 2, pp. 367-373.AlgeriaIndicator minerals, Pyropes, diamonds
DS1992-1447
1992
Sobolev, N.V.Sobolev, N.V., Hassan Abu-Assak, V.V., et al.Lamprophyres of Cretaceous diatremes of the Syrian RiftDoklady Academy of Sciences USSR, Earth Science Section, Vol. 314, No. 1-6, July 1992, pp. 129-132.SyriaLamprophyres, Diatremes
DS1992-1448
1992
Sobolev, N.V.Sobolev, N.V., Mankenda, S.A., Kaminsky, F.V., Sobolev, V.N.Garnets from kimberlites of northeastern Angola and correlations between their compositions and diamond content.Doklady Academy of Sciences USSR, Earth Science Section, Vol. 315, pp. 238-242.AngolaGarnet mineralogy, Diamond content
DS1992-1449
1992
Sobolev, N.V.Sobolev, N.V., Pokhilenko, N.P., Grib, V.P., Skripnichenko, V.A.Specific composition and conditions of formation of deep seated mineralsRussian Geology and Geophysics, Vol. 33, No. 10, pp. 71-78.Russia, Commonwealth of Independent States (CIS), Arkangelsk, RussiaZolotisa Field, Tectonics, Explosion pipes, Kimberlites
DS1992-1450
1992
Sobolev, N.V.Sobolev, N.V., Sinitsyn, A.V., Kushev, V.G.Structural metallogeny of Diamondiferous kimberlitesRussian Geology and Geophysics, Vol. 33, No. 10, pp. 1-3.Russia, Commonwealth of Independent States (CIS), ArkangelskStructure, Metallogeny
DS1993-0398
1993
Sobolev, N.V.Eggler, D.H., Harris, J.W., Sobolev, N.V.Oxidation state of eclogitic diamond sulfide inclusionsGeological Society of America Annual Abstract Volume, Vol. 25, No. 6, p. A99 abstract onlySouthern AfricaEclogite, Diamond inclusions
DS1993-0585
1993
Sobolev, N.V.Griffin, W.L., Sobolev, N.V., Ryan, C.G., Pokhilenko, N.P., WinTrace elements in garnets and chromites: diamond formation in the SiberianlithosphereLithos, Vol. 29, pp. 235-256Russia, Commonwealth of Independent States (CIS), Siberia, YakutiaGeochemistry, Diamond genesis
DS1993-0729
1993
Sobolev, N.V.Jacob, D.E., Jagoutz, E., Sobolev, N.V.Isotopic systematics of subcalcic garnets from SiberiaEos, Transactions, American Geophysical Union, Vol. 74, No. 16, April 20, supplement abstract p. 320Russia, SiberiaGeochemistry -garnets, Geochronology
DS1993-0749
1993
Sobolev, N.V.Jerde, E.A., Taylor, L.A., Crozaz, G., Sobolev, N.V.Exsolution of garnet within clinopyroxene of mantle eclogites - major element and trace-element chemistryContribution to Mineralogy and Petrology, Vol. 114, No. 2, June pp. 148-159MantleEclogites, Geochemistry
DS1993-0750
1993
Sobolev, N.V.Jerde, E.A., Taylor, L.A., Crozaz, G., Sobolev, N.V., Sobolev, V.N.Diamondiferous eclogites from Yakutia, Siberia: evidence for a diversity ofprotolithsContribution to Mineralogy and Petrology, Vol. 114, No. 2, June pp. 189-202GlobalEclogites, Udachnaya pipe, chemistry, geobarometry
DS1993-0767
1993
Sobolev, N.V.Kadik, A.A., Zharkova, E.V., Efimova, E.S., Sobolev, N.V.Electrochemical determination of intrinsic oxygen fugacity of diamondcrystals. (Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 328, No. 3, January pp. 386-389Russia, Commonwealth of Independent States (CIS), YakutiaDiamond morphology
DS1993-0879
1993
Sobolev, N.V.Langer, K., Robarick, E., Sobolev, N.V., Shatsky, V.S.Single crystal spectra of garnets from Diamondiferous high pressure metamorphic rocks from Kazakhstan -indications for OH-,H2O, and FeTi chargetransfer.European Journal of Mineralogy, Vol. 5, No. 6, Nov-Dec pp. 1091-1100.Russia, KazakhstanMetamorphic rocks, Mineralogy -garnets
DS1993-1442
1993
Sobolev, N.V.Shatsky, V.S., Jagoutz, E., Kozmenko, O.A., Blinchik, T.M., Sobolev, N.V.Age and genesis of eclogites from the Kokchetav massif (northernKazakhstan).Russian Geology and Geophysics, Vol. 34, No. 12, pp. 40-50.Russia, KazakhstanGeochronology, Eclogites
DS1993-1443
1993
Sobolev, N.V.Shatsky, V.S., Sobolev, N.V.Some specific features of the origin of diamonds in metamorphicrocks.(Russian)Doklady Academy of Sciences Akad. Nauk, (Russian), Vol. 331, No. 2, July pp. 217-218.RussiaDiamond, Metamorphic rocks
DS1993-1494
1993
Sobolev, N.V.Snyder, G.A., Jerde, E.A., Taylor, L.A., Sobolev, N.V.Earliest differentiation of the earth's mantle: evidence from the isotopic studies of Diamondiferous eclogites, Yakutia, Siberia, Russia.Geological Society of America Annual Abstract Volume, Vol. 25, No. 6, p. A73 abstract onlyRussia, Yakutia, RussiaGeochronology, Eclogites
DS1993-1498
1993
Sobolev, N.V.Sobolev, N.V., Galimov, E.M., Efimova, E.S., Sobolev, E.V.Crystalline inclusions, isotopes carbon, nitrogen centers in diamonds, features of garnet from Madjgawan.Russian Geology and Geophysics, Vol. 34, No. 12, pp. 77-83.IndiaDiamond inclusions, Deposit -Madjgawan
DS1993-1499
1993
Sobolev, N.V.Sobolev, N.V., Pokhilenko, N.P., Afanasev, V.P.Kimberlite pyropes and chromites morphology and chemistry as indicators of diamond grade in Yakutian and Arkangelsk Provinces.Mid-continent diamonds Geological Association of Canada (GAC)-Mineralogical Association of Canada (MAC) Symposium ABSTRACT volume, held Edmonton May, pp. 63-70.Russia, Commonwealth of Independent States (CIS), YakutiaMineral chemistry, Diamond morphology
DS1993-1500
1993
Sobolev, N.V.Sobolev, N.V., Shimizu, N.Trace element variations in diamond inclusion garnets from Siberian kimberlite pipes.American Geophysical Union, EOS, supplement Abstract Volume, October, Vol. 74, No. 43, October 26, abstract p. 637.Russia, SiberiaDiamond inclusions, Deposit -Siberian ones
DS1993-1653
1993
Sobolev, N.V.Vavilov, M.A., Sobolev, N.V., Shatskiy, V.S.Micas in diamond bearing metamorphic rocks of northern KazakhstanDoklady Academy of Sciences USSR, Earth Science Section, Vol. 319A, No. 6, Publishing July 1993, pp. 177-182.Russia, KazakhstanMetamorphic rocks
DS1994-0012
1994
Sobolev, N.V.Afanasev, V.P., Sobolev, N.V., Kirillov, E.A., Yusupov, I.S.Relative abrasive stability of pyrope and pyroilmenite -indicator minerals of kimberlite.(Russian)Doklady Academy of Sciences Nauk, Vol. 337, No. 3, July pp. 359-362.Russia, SiberiaMineralogy, Indicator minerals
DS1994-0299
1994
Sobolev, N.V.Chepurov, A.I., Fedorov, A.I., Sonin, V.M., Sobolev, N.V.Diamond formation in the system (iron, nickel) S-C H at high pressure/temperature parameters. (Russian)Doklady Academy of Sciences Nauk. SSSR, (Russian), Vol. 336, No. 2, May pp. 238-240. # NR556RussiaDiamond genesis, Iron, nickel
DS1994-0666
1994
Sobolev, N.V.Griffin, W.L., Ryan, C.G., Gurney, J.J., Sobolev, N.V., Win, T.T.Chromite macrocrysts in kimberlites and lamproites: geochemistry andorigin. #2Proceedings of Fifth International Kimberlite Conference, Vol. 1, pp. 366-377.AustraliaChromite, Geochemistry
DS1994-0991
1994
Sobolev, N.V.Lawrence, Qu, Qi, Taylor, A., Sobolev, N.V.Eclogites from the Obnazhennaya kimberlite pipe, Yakutia, RussiaInternational Geology Review, Vol. 36, No. 10, Oct. 1, pp. 911-924.RussiaEclogites, petrology, Deposit - Obnazhennaya
DS1994-1589
1994
Sobolev, N.V.Shigley, J.E., Fritsch, E., Koivula, J.I., Sobolev, N.V.The gemological properties of Russian gem quality synthetic yellowdiamonds.Gems and Gemology, Vol. 29, Winter, pp. 228-248.RussiaSynthetic diamonds, Colour -yellow
DS1994-1591
1994
Sobolev, N.V.Shimizu, N., Boyd, F.R., Sobolev, N.V., Pokhilenko, N.P.Chemical zoning of garnets in peridotites and diamondsMineralogical Magazine, Vol. 58A, pp. 831-832. AbstractSouth Africa, Russia, YakutiaGeochemistry, mineral inclusions, Diamond inclusions
DS1994-1653
1994
Sobolev, N.V.Sobolev, N.V.Diamondiferous eclogites from the Siberian platform: samples with peridotite signatures. #1Eos, Vol. 75, No. 16, April 19, p. 192.RussiaEclogites, Peridotites
DS1994-1654
1994
Sobolev, N.V.Sobolev, N.V., Afanasyev, V.P., Pokhilenko, N., Kaminsky, F.Pyropes and diamonds from the Algerian SaharaDoklady Academy of Sciences USSR, Vol. 326, Oct. pp. 151-157.AlgeriaAlluvials, Geochemistry -garnets
DS1994-1655
1994
Sobolev, N.V.Sobolev, N.V., Bakumento, L.T., et al.Morphology of microscopic diamonds containing traces of sodium in garnet sand of potassium in pyroxenes.Doklady Academy of Sciences USSR, Earth Science Section, Vol. 322, No. 1, pp. 138-146.RussiaDiamond morphology, eclogite xenoliths, Deposit -Udachnaya
DS1994-1656
1994
Sobolev, N.V.Sobolev, N.V., Shatskiy, V.S., Vavilov, MM.A., GoryainoZirconium from metamorphic rocks of folded regions a unique container of inclusions diamond, coesite (Russian)Doklady Academy of Sciences Nauk.(Russian), Vol. 334, No. 4, Feb. pp. 488-492.RussiaMetamorphic rocks, Coesite
DS1994-1657
1994
Sobolev, N.V.Sobolev, N.V., Shatsky, V.S., Vavilov, M.A., Goryaynov, S.A coesite inclusion in zircon from diamond containing gneiss of Kokchetav:first find coesite in metamorphic rocks of the USSRDoklady Academy of Sciences USSR, Earth Science Section, Vol. 322, No. 1, pp. 123-127.RussiaDiamond inclusions, Coesite
DS1994-1658
1994
Sobolev, N.V.Sobolev, V.N., Taylor, L.A., Snyder, G.A., Sobolev, N.V.Diamondiferous eclogites from the Udachnaya kimberlite pipe, YakutiaInternational Geology Review, Vol. 36, No. 1, Jan. pp. 42-64.Russia, YakutiaEclogites, Deposit -Udachnaya
DS1995-0192
1995
Sobolev, N.V.Boyd, F.R., Pokhilenko, N.P., Pearson, D.G., Sobolev, N.V.Peridotite xenoliths from the Udachnaya kimberlite pipeProceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 57-59.Russia, YakutiaXenoliths, Deposit -Udachnaya
DS1995-0314
1995
Sobolev, N.V.Chopin, C., Sobolev, N.V.Principal mineralogic indicators of ultra high pressure (UHP) in crustal rocksCambridge University of Press, pp. 96-131.GlobalGarnet, clinopyroxene, microdiamonds, Crustal rocks
DS1995-0424
1995
Sobolev, N.V.Dobretsov, N.I., Shatsky, V.S., Sobolev, N.V.Comparison of the Kokchetav and Dabie Shan metamorphic complexes: coesite and diamond bearing rocks ultra high pressure (UHP)-HP...International Geology Review, Vol. 37, pp. 636-656.ChinaCoesite, metamorphism, Deposit -Kokchetav, Dabie Shan
DS1995-0862
1995
Sobolev, N.V.Jacob, D.E., Jagoutz, E., Sobolev, N.V., Sorowka, A.Isotopic analysis ( Samarium/neodymium, Rubidium-Strontium and Uranium/lead) of single subcalcic garnet grains from Yakutian kimberlites.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 257-259.Russia, YakutiaGeochemistry, isotopes, Geochronology -garnets
DS1995-1104
1995
Sobolev, N.V.Logvinova, A.M., Sobolev, N.V.Morphology and composition of mineral inclusions in chromite macrocrysts from kimberlites and lamproites.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 331-332.Russia, Yakutia, South Africa, Australia, United StatesMorphology -Mineral inclusions, Kimberlites, lamproites
DS1995-1507
1995
Sobolev, N.V.Pokhilenko, N.P., Sobolev, N.V.Mineralogical mapping of the southeast section of the Yakutian kimberlite province and its main results.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 446-448.Russia, YakutiaMineralogy, Deposit -Olenek River Basin area
DS1995-1720
1995
Sobolev, N.V.Shatsky, V.S., Sobolev, N.V., Jagoutz, E., Vavilov, M.A.Ultrahigh pressure metamorphic environment of microdiamondsProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 512-514.Russia, KazakhstanMetamorphic, Deposit -Kokchetav Massif
DS1995-1721
1995
Sobolev, N.V.Shatsky, V.S., Sobolev, N.V., Vavilov, M.A.Diamond bearing metamorphic rocks of the Kokchetav Massif, NorthernKazakhstan.Cambridge University of Press, pp. 427-455.Russia, KazakhstanMetamorphic rocks, Diamond - Kokchetav Massif
DS1995-1737
1995
Sobolev, N.V.Shimizu, N., Sobolev, N.V.Young peridotitic diamonds from the Mir kimberlite pipeNature, Vol. 375, No. 6530, June 1, pp. 394-396.RussiaDiamond morphology, Deposit -Mir
DS1995-1738
1995
Sobolev, N.V.Shimizu, N., Sobolev, N.V., Yefimova, E.S.Chemical heterogeneities of peridotitic inclusion garnets and juvenility ofdiamonds.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 526-528.Russia, YakutiaGeochemistry, Deposit -Mir, Udachnaya, Aikhal
DS1995-1772
1995
Sobolev, N.V.Smirnov, G.I., Chashka, A.I., Sobolev, N.V., TarasyukTypomorphic features of high baric minerals from kimberlites of theUkraine.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 541-542.UKraineXenoliths, Deposit -Azov
DS1995-1790
1995
Sobolev, N.V.Snyder, G.A., Taylor, L.A., Beard, B.L., Sobolev, N.V.Siberian eclogite xenoliths: keys to differentiation of the Archeanmantle.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 549-551.Russia, YakutiaEclogite xenoliths, Deposit -Udachnaya. Mir
DS1995-1793
1995
Sobolev, N.V.Sobolev, N.V., Shatskiy, V.S., Vavilov, GoryaynovZircon in high pressure metamorphic rocks in folded regions as a unique container of inclusions.....Doklady Academy of Sciences, Vol. 336, No. 4, Nov., pp. 79-85.Russia, Kokchetau MassifCoesite, diamond, Inclusions
DS1995-1794
1995
Sobolev, N.V.Sobolev, N.V., Yefimova, E., Reimers, Zakharchenko, MakhinArkhangelsk diamond inclusionsProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 558-560.Russia, ArkangelskDiamond inclusions, Deposit -Lomonosov, Pionerskaya, Karpinski, Pomorskaya
DS1995-1797
1995
Sobolev, N.V.Sobolev, V.N., Taylor, L.A., Snyder, G.A., Sobolev, N.V.Diamondiferous eclogites from the Siberian Platform: samples with peridotitic signature? #2Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 552-554.Russia, SiberiaEclogites, Peridotites
DS1996-0101
1996
Sobolev, N.V.Beard, B.L., Fracacci, K.N., Sobolev, N.V.Petrography and geochemistry of eclogites from the Mir kimberlite, Russia.Contributions to Mineralogy and Petrology, Vol. 125, No. 4, pp. 293-310.Russia, YakutiaGeochemistry, Deposit - Mir
DS1996-0267
1996
Sobolev, N.V.Chepurov, A.I., Fedorov, I.I., Sonin, V.M., Sobolev, N.V.Diamond formation in the system (iron, nickel)-S-C-H at high pressures andtemperatures.Doklady Academy of Sciences, Vol. 338, No. 7, Jan. pp. 61-65.GlobalPetrology -experimental, Diamond genesis
DS1996-1294
1996
Sobolev, N.V.Shatskiy, V.S., Sobolev, N.V.Some aspects of the origin of diamonds in metamorphic rocksDoklady Academy of Sciences, Vol. 336, pp. 67-70.Russia, Kokchetau MassifZewrenda series, Metamorphic rocks
DS1996-1403
1996
Sobolev, N.V.Taylor, L.A., Snyder, G.A., Sobolev, N.V.Eclogitic inclusions in diamonds: evidence of complex mantle processes overtime.Earth and Planetary Science Letters, Vol. 142, No. 3/4, Aug. 1, pp. 535-552.RussiaEcologites, Diamond inclusions
DS1996-1604
1996
Sobolev, N.V.Zharkova, E.V., Kadik, A.A., Sobolev, N.V.Olivine from diamonds -bearing peridotite xenoliths: redox conditions of their formation (Udachnaya pipe).International Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 391.RussiaIGF -olivines, Deposit -Udachnaya
DS1997-1038
1997
Sobolev, N.V.Shimizu, N., Sobolev, N.V., Yefimova, E.S.Chemical heterogeneities of garnets and juvenile character of peridotitic diamonds from Siberia.Russian Geology and Geophysics, Vol. 38, No. 2, pp. 356-372.Russia, SiberiaGeochemistry, Diamond inclusions, garnet zoning
DS1997-1072
1997
Sobolev, N.V.Snyder, G.A., Taylor, L.A., Sobolev, N.V.The origins of Yakutian eclogite xenolithsJournal of Petrology, Vol. 38, No. 1, Jan. 1, pp. 85-114.Russia, YakutiaEclogite, Xenolith
DS1997-1073
1997
Sobolev, N.V.Sobolev, N.V., Kaminsky, F.V., Botkunova, A.I., Griffin, W.L., YefimovaMineral inclusions in diamonds from the Sputnik kimberlite pipe, YakutiaLithos, Vol. 39, No. 3-4, Feb. 1, pp. 135-158.Russia, YakutiaMineral chemistry, Diamond inclusions, mineralogy, Deposit - Sputnik
DS1997-1074
1997
Sobolev, N.V.Sobolev, N.V., Yefimova, Reimers, Zakharchenko, MakhinMineral inclusions in diamonds of the Arkangelsk kimberlite provinceRussian Geology and Geophysics, Vol. 38, No. 2, pp. 379-393.RussiaDiamond inclusions, Deposit - Zolotitsky, Lomonosov, Karpinsky, Pionerskaya
DS1998-0029
1998
Sobolev, N.V.Andre, L., Shatsky, V.S., De Corte, K., Sobolev, N.V.Potassium rich clinopyroxenes as mantle conveyers of crustal derived components.7th International Kimberlite Conference Abstract, pp. 17-19.Australia, RussiaMicroanalyses - omphacite, clinopyroxene, Deposit - Argyle, Kochetav Massif
DS1998-0082
1998
Sobolev, N.V.Barron, K.M., Logvinova, A.M., Sobolev, N.V.Morphology and composition of chromite macrocrysts and their inclusions Guaniamo kimberlite field, Venezuela.7th International Kimberlite Conference Abstract, pp. 43-45.Venezuela, BolivarChromites, Deposit - Guaniamo
DS1998-0674
1998
Sobolev, N.V.Jacob, D.E., Jagoutz, E., Sobolev, N.V.Neodynium and strontium isotopic measurements on single subcalcic garnet grains from Yakutian kimberlites.Neues Jahrbuch f?r Mineralogie Abh., No. 172, pp. 357-379.Russia, YakutiaGeochronology
DS1998-0791
1998
Sobolev, N.V.Korsakov, A.V., Shatsky, V.S., Sobolev, N.V.The first finding of coesite in the eclogites of the Kokchetav MassifDoklady Academy of Sciences, Vol. 360, No. 4, pp. 469-73.RussiaEclogites, Coesite
DS1998-0891
1998
Sobolev, N.V.Logvinova, A.M., Federova, E.N., Sobolev, N.V.Microdiamonds from the Yubileinaya kimberlite pipe, Yakutia: morphology, physical properties, inclusions..7th International Kimberlite Conference Abstract, pp. 512-14.Russia, YakutiaDiamond morphology, mineral inclusions, Deposit - Yubileynaya
DS1998-1175
1998
Sobolev, N.V.Pokhilenko, N.P., Sobolev, N.V., Kuligin, ShimizuPeculiarities of pyroxenite paragenesis garnets distribution in Yakutian kimberlites .. craton mantle7th. Kimberlite Conference abstract, pp. 702-4.Russia, Siberia, YakutiaCraton - lithospheric mantle evolution, Magmatism
DS1998-1342
1998
Sobolev, N.V.Shimizu, N., Sobolev, N.V., Yefimova, E.S.Trace element heterogeneities of in situ diamond inclusion garnets fromSiberia.7th International Kimberlite Conference Abstract, p. 807.Russia, SiberiaDiamond inclusions
DS1998-1344
1998
Sobolev, N.V.Shiryaev, A.A., Galimov, E.M., Sobolev, N.V., KolesovTrace elements in inclusion free diamonds from Venezuela and Arkhangelskdeposits.7th International Kimberlite Conference Abstract, pp. 811-13.Russia, Kola, VenezuelaDiamond formation, genesis, Mineral inclusions
DS1998-1370
1998
Sobolev, N.V.Sobolev, N.V., Efimova, E.S.Compositional variations of chromite inclusions as an indicator of the zonation of diamond crystals.Doklady Academy of Sciences, Vol. 359, No. 2, pp. 163-166.GlobalDiamond inclusions, Chromite
DS1998-1371
1998
Sobolev, N.V.Sobolev, N.V., Snyder, G.A., et al.Extreme chemical diversity in the mantle during eclogitic diamondformation: evidence from inclusions..International Geology Review, Vol. 40, No. 7, pp. 567-578.Russia, YakutiaDiamond inclusions, mineral chemistry, Deposit - Mir
DS1998-1372
1998
Sobolev, N.V.Sobolev, N.V., Yefimova, Channer, Anderson, BarronUnusual upper mantle beneath Guaniamo, Guyana Shield, Venezuela: evidence from diamond inclusions.Geology, Vol. 26, No. 11, Nov. pp. 971-974.VenezuelaEcogitic, peridotitic, ultrmafic type, Roraima Group
DS1998-1373
1998
Sobolev, N.V.Sobolev, N.V., Yefimova, E.S., Channer, D., AndersonA unique eclogitic source of Guaniamo diamonds, Guyana Shield, Venezuela7th International Kimberlite Conference Abstract, pp. 829-31.Venezuela, GuyanaEclogites, Diamond genesis
DS1998-1374
1998
Sobolev, N.V.Sobolev, N.V., Yefimova, E.S., Koptil, V.I.Crystalline inclusions in diamonds in the northeast of the Yakutian diamondiferous province.7th International Kimberlite Conference Abstract, pp. 832-4.Russia, YakutiaDiamond inclusions, Deposit - Dianga
DS1999-0561
1999
Sobolev, N.V.Pokhilenko, N.P., Sobolev, N.V., Kuligin, S.S., ShimizuPeculiarities of distribution of pyroxenite paragenesis garnets in Yakutian kimberlites and some aspects of...7th International Kimberlite Conference Nixon, Vol. 2, pp. 689-98.Russia, Yakutia, KharamaiCraton - evolution of Siberian craton, petrography, Udachnaya, Obnazhennaya
DS1999-0692
1999
Sobolev, N.V.Sobolev, N.V., Sobolev, V.N., Taylor, L.A.Significance of eclogitic and related parageneses of natural diamonds #1International Geology Review, Vol. 41, No. 2, Feb. pp. 129-40.Russia, YakutiaDiamond morphology, Eclogites, genesis
DS1999-0693
1999
Sobolev, N.V.Sobolev, N.V., Yefimova, E.S., Koptil, V.I.Mineral inclusions in diamonds in the northeast of the Yakutian Diamondiferous province.7th International Kimberlite Conference Nixon, Vol. 2, pp. 816-22.Russia, Siberia, YakutiaDiamond - inclusions, Deposit - Olenek, Anabar, Lena, Ebelyakh, Dianga
DS1999-0694
1999
Sobolev, N.V.Sobolev, V.N., Taylor, L.A., Sobolev, N.V.Quantifying the effects of metasomatism in mantle xenoliths: constraints from secondary chemistry ...International Geology Review, Vol. 41, No. 5, pp. 391-416.Russia, YakutiaMIneralogy, Geochemistry, eclogites, Deposit - Udachnaya
DS2000-0771
2000
Sobolev, N.V.Pokhilenko, N.P., Sobolev, N.V., Chernyi, S.D., YanginPyropes and chromites from kimberlites in the Nakyn Field, and Snipe Lake (Slave River region) Evidence...Doklady Academy of Sciences, Vol. 372, No. 4, May-June pp. 638-42.Northwest Territories, Russia, YakutiaLithosphere - structure, Deposit - Nakyn, Snipe Lake
DS2000-0816
2000
Sobolev, N.V.Reutskii, V.N., Efimova, E.S., Sobolev, N.V.Isotopic composition of carbon in polycrystalline aggregates of diamond with inclusions of garnet/rutileRussian Geology and Geophysics, Vol.41,12,pp.1690-6., Vol.41,12,pp.1690-6.Russia, YakutiaDiamond inclusions, Deposit - Mir
DS2000-0817
2000
Sobolev, N.V.Reutskii, V.N., Efimova, E.S., Sobolev, N.V.Isotopic composition of carbon in polycrystalline aggregates of diamond with inclusions of garnet/rutileRussian Geology and Geophysics, Vol.41,12,pp.1690-6., Vol.41,12,pp.1690-6.Russia, YakutiaDiamond inclusions, Deposit - Mir
DS2000-0907
2000
Sobolev, N.V.Sobolev, N.V., Logvinova, A.M., et al.Anomously high nickel admixture in olivine inclusions from microdiamonds, the Juileinaya kimberlite pipe, YakutiaDoklady Academy of Sciences, Vol. 375A, No. 9, pp. 1403-6.Russia, Siberia, YakutiaMicrodiamonds, Deposit - Yubileinaya
DS2000-0908
2000
Sobolev, N.V.Sobolev, N.V., Sobolev, V.N., Snyder, Yefimova, TaylorSignificance of eclogitic and related parageneses of natural diamonds #2Snyder, Neal, Ernst, Plan. Petrology and Geochemistry, pp. 15-26.GlobalDiamond - morphology, Diamond - genesis
DS2000-0909
2000
Sobolev, N.V.Sobolev, N.V., Yefimova, E.S.Composition and petrogenesis of Ti oxides associated with diamondsInternational Geology Review, Vol. 42, No. 8, pp. 758-RussiaDiamond - inclusions, Petrology
DS2001-0350
2001
Sobolev, N.V.Fursenko, B.A., Goryainov, S.V., Sobolev, N.V.high pressure coesite inclusions in diamond: Raman spectroscopyDoklady Academy of Sciences, Vol. 379A, No. 6, July-August pp. 749-51.GlobalCoesite, Diamond - inclusions
DS2001-0599
2001
Sobolev, N.V.Khokhryakov, A.F., Palyanov, Y.N., Sobolev, N.V.Evolution of crystal morphology of natural diamond in dissolution processes: experimental data.Doklady Academy of Sciences, Vol. 381, No. 8, Oct/Nov. pp. 884-88.GlobalDiamond - morphology
DS2001-0600
2001
Sobolev, N.V.Khokhryakov, A.P., Palyanov, Y.N., Sobolev, N.V.Evolution of crustal morphology of natural diamond in dissolution processes: experimental data.Doklady, Vol. 381, No. 8, pp. 884-88.GlobalDiamond - morphology
DS2001-0936
2001
Sobolev, N.V.Pokhilenko, N.P., Sobolev, N.V., McDonald, Hall et alCrystalline inclusions in diamonds from kimberlites of the Snap lake: new evidence anomalous lithosphericDoklady Academy of Sciences, Vol. 380, No. 7, Sept-Oct. pp.806-12.Northwest TerritoriesDiamond - inclusions, Deposit - Snap lake
DS2001-1096
2001
Sobolev, N.V.Sobolev, N.V., Efimova, E.S., Loginova, SukhodolskayaAbundance and composition of mineral inclusions in large diamonds from Yakutia.Doklady Academy of Sciences, Vol. 376, No. 1, Jan-Feb. pp. 34-8.Russia, YakutiaDiamond - inclusions
DS2001-1097
2001
Sobolev, N.V.Sobolev, N.V., Schertl, H.P., Burchard, M., Shatsky, V.An unusual pyrope grossular garnet and its paragenesis from Diamondiferous carbonate silicate rocks KokchetavDoklady Academy of Sciences, Vol. 380, No. 7, Sept-Oct. pp.791-4.Russia, KazakhstanMineralogy - pyrope, Deposit - Kokchetav Massif
DS2002-0841
2002
Sobolev, N.V.Khikhryakov, A.F., Palyanov, Y.N., Sobolev, N.V.Crystal morphology as an indicator of redox conditions of natural diamond dissolution at the mantle Pt parameters.Doklady, Vol.385,June-July, pp. 534-7.MantleDiamond - mineralogy
DS2002-0891
2002
Sobolev, N.V.Korsakov, A.V., Shatsky, V.S., Sobolev, N.V., Zayachokovosky, A.A.Garnet biotite clinozoisite gneiss: a new type of Diamondiferous metamorphic rock from the Kokchetav Massif.European Journal of Mineralogy, Vol. 14, 5, pp. 915-28.RussiaDiamond genesis
DS2002-1207
2002
Sobolev, N.V.Palyanov, Y.N., Sokol, A.G., Borzdov, Y.M., Khokhryakov, A.F., Sobolev, N.V.Diamond formation through carbonate silicate interactionAmerican Mineralogist, Vol. 87, pp. 1009-13.GlobalDiamond - crystallography, genesis, carbon, magnesite, Petrology - experimental
DS2002-1328
2002
Sobolev, N.V.Reutskii, V.N., Pokhilenko, N.P., Hall, A.E., Sobolev, N.V.Polygenous character of diamonds from kimberlites of the Snap lake region ( SlaveDoklady Earth Sciences, Vol. 386, 7, Sept-Oct.pp. 791-4.Northwest TerritoriesDiamond - morphology, Deposit - Snap Lake
DS2002-1520
2002
Sobolev, N.V.Sobolev, N.V., Taylor, L.A.Determining the provenance of a diamond: chromite inclusions as a Russian signatureEos, American Geophysical Union, Spring Abstract Volume, Vol.83,19, 1p.Russia, YakutiaDiamond - inclusions
DS2003-0014
2003
Sobolev, N.V.Anand, M., Taylor, L.A., Carlson, R.C., Taylor, D-H., Sobolev, N.V.Diamond genesis revealed by x-ray tomography of Diamondiferous eclogites8ikc, Www.venuewest.com/8ikc/program.htm, Session 2, POSTER abstractRussia, Siberia, YakutiaEclogites and Diamonds
DS2003-0015
2003
Sobolev, N.V.Anand, M., Taylor, L.A., Misra, K.C., Carlson, W.D., Sobolev, N.V.Diamondiferous eclogite dissections: anomalous diamond genesis?8 Ikc Www.venuewest.com/8ikc/program.htm, Session 2, AbstractRussia, YakutiaEclogites, diamonds, Genesis
DS2003-0330
2003
Sobolev, N.V.Dencker, I., Nimis, P., Zanetti, A., Sobolev, N.V.Major and trace elements composition of Cr diopsides from the Zagadochnaya8ikc, Www.venuewest.com/8ikc/program.htm, Session 4, POSTER abstractRussia, YakutiaMantle geochemistry, Deposit - Zagadochnaya
DS2003-0480
2003
Sobolev, N.V.Golovin, A.V., Sharygin, V.V., Pokhilenko, N.P., Malkovets, V.G., Sobolev, N.V.Secondary melt inclusions in olivine from unaltered kimberlites of the Udachnaya8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, POSTER abstractRussia, YakutiaDeposit - Udachnaya
DS2003-0540
2003
Sobolev, N.V.Hamilton, M.A., Sobolev, N.V., Stern, R.A., Pearson, D.G.SHRIMP U Pb dating of a perovskite inclusion in diamond: evidence for a syneruption8ikc, Www.venuewest.com/8ikc/program.htm, Session 3, POSTER abstractRussia, Siberia, YakutiaDiamonds - inclusions, geochronology, Deposit - Sytykanskaya
DS2003-0725
2003
Sobolev, N.V.Klein Ben David, O., Logvinova, A.M., Izraeli, E.S., Sobolev, N.V., Navon, O.Sulfide melt inclusions in Yubileinaya ( Yakutia) diamonds8ikc, Www.venuewest.com/8ikc/program.htm, Session 3, POSTER abstractRussia, Siberia, YakutiaDiamonds - inclusions, Deposit - Yubileinaya
DS2003-0837
2003
Sobolev, N.V.Loginova, A.M., Klein-Ben David, O., Israeli, E.S., Navon, O., Sobolev, N.V.Micro inclusions in fibrous diamonds from Yubileinaya kimberlite pipe, Yakutia8ikc, Www.venuewest.com/8ikc/program.htm, Session 3, POSTER abstractRussia, YakutiaDiamonds - inclusions, Deposit - Yubileinaya
DS2003-0871
2003
Sobolev, N.V.Malygina, E.V., Pokhilenko, N.P., Sobolev, N.V.Coarse peridotite xenoliths of Udachnaya kimberlite pipe, Yakutia: garnetization of8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, POSTER abstractRussia, Siberia, YakutiaDeposit - Udachnaya
DS2003-0991
2003
Sobolev, N.V.Nadolinny, V.A., Shatsky, V.S., Sobolev, N.V., Twitchen, D.J., Yuryeva, O.P.Observation and interpretation of paramagnetic defects in Brazilian and Central AfricanAmerican Mineralogist, Vol.88, pp. 11-17.Brazil, Central African RepublicSpectroscopy - nitrogen
DS2003-1043
2003
Sobolev, N.V.Palyanov, Yu.N., Borzdov, Yu.M., Ovchinnikov, I.Yu., Sobolev, N.V.Experimental study of the interaction between pentlandite melt and carbon at mantle PtDoklady Earth Sciences, Vol. 392, Sept-Oct. pp. 1026-29.MantleCrystallography
DS2003-1090
2003
Sobolev, N.V.Pokhilenko, N.P., Agashev, A.M., McDonald, J.A., Sobolev, N.V., MityukhinKimberlites of the Nakyn field, Siberia and the Snap Lake King Lake dyke system8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, POSTER abstractNorthwest TerritoriesDeposit - Snap Lake, King Lake
DS2003-1093
2003
Sobolev, N.V.Pokhilenko, N.P., McDonald, J.A., Sobolev, N.V., Reutsky, V.N., Hall, A.E.Crystalline inclusions and C isotope composition of diamonds from the Snap lake/King8 Ikc Www.venuewest.com/8ikc/program.htm, Session 3, AbstractNorthwest TerritoriesDiamonds - geochronology, Deposit - Snap Lake
DS2003-1259
2003
Sobolev, N.V.Sharygin, V.V., Golovin, A.V., Pokhilenko, N.P., Sobolev, N.V.Djerfisherite in unaltered kimberlites of the Udachnaya East pipe, YakutiaDoklay Earth Sciences, Vol. 390, 4, May-June pp. 554-8.RussiaMineralogy, Deposit - Udachnaya
DS2003-1305
2003
Sobolev, N.V.Sobolev, N.V., Loginova, A.M., Yefimova, E.S., Zedgenizov, D.A., Channer, D.Polymineralic eclogite inclusions in Guaniamo diamonds, Venezuela: evidence for8ikc, Www.venuewest.com/8ikc/program.htm, Session 2, POSTER abstractVenezuelaEclogites and Diamonds, Deposit - Guaniamo
DS2003-1306
2003
Sobolev, N.V.Sobolev, N.V., Loginova, A.M., Zedgenizov, D.A., Yefimova, E.S., Taylor,L.A.Mineral inclusions in diamonds from the Komsomolskaya and Krasnopresnenskaya8ikc, Www.venuewest.com/8ikc/program.htm, Session 3, POSTER abstractRussia, SiberiaDiamonds - inclusions, Deposit - Komosomolskaya, Krasnopresnenskaya
DS2003-1307
2003
Sobolev, N.V.Sobolev, N.V., Logvinova, A.M., Zedgenizov, D.A., Yefimova, E.S.Mineral inclusions in microdiamonds and macrodiamonds from kimberlites of Yakutia: a8 Ikc Www.venuewest.com/8ikc/program.htm, Session 3, AbstractRussia, Yakutia, SiberiaDiamonds - inclusions
DS2003-1308
2003
Sobolev, N.V.Sobolev, N.V., Shatsky, V.S., Liou, J.G., Zhang, R.Y., Hwang, Shen, Chu, YuiAn origin of microdiamonds in metamorphic rocks of the Kokchetav Massif, northernEpisodes, Russia, KazakhstanBlank
DS2003-1364
2003
Sobolev, N.V.Taylor, L.A., Anand, M., Promprated, P., Floss, C., Sobolev, N.V.The significance of mineral inclusions in large diamonds from Yakutia, RussiaAmerican Mineralogist, Vol. 88, 5/6, pp. 912-928.Russia, YakutiaDiamond - inclusions, protogenetic, Deposit - Udachnaya, Mir, Aikhal
DS200412-0028
2003
Sobolev, N.V.Anand, M., Taylor, L.A., Misra, K.C., Carlson, W.D., Sobolev, N.V.Diamondiferous eclogite dissections: anomalous diamond genesis?8 IKC Program, Session 2, AbstractRussia, YakutiaEclogite, diamonds Genesis
DS200412-0029
2004
Sobolev, N.V.Anand, M., Taylor, L.A., Misra, K.C., Carlson, W.D., Sobolev, N.V.Nature of diamonds in Yakutian eclogites: views from eclogite tomography and mineral inclusions in diamonds.Lithos, Vol. 77, 1-4, Sept. pp. 333-348.Russia, YakutiaUdachnaya, diamond inclusions, eclogte, xenoliths
DS200412-0685
2003
Sobolev, N.V.Golovin, A.V., Sharygin, V.V., Pkhilenko, N.P., Malkovets, V.G., Kolesov, B.A., Sobolev, N.V.Secondary melt inclusions in olivine from unaltered kimberlites of the Udachnaya East pipe, Yakutia.Doklady Earth Sciences, Vol. 388, 1, pp. 93-96.Russia, YakutiaGeochemistry - mineral chemistry
DS200412-0686
2003
Sobolev, N.V.Golovin, A.V., Sharygin, V.V., Pokhilenko, N.P., Malkovets, V.G., Sobolev, N.V.Secondary melt inclusions in olivine from unaltered kimberlites of the Udachnaya eastern pipe, Yakutia.8 IKC Program, Session 7, POSTER abstractRussia, YakutiaKimberlite petrogenesis Deposit - Udachnaya
DS200412-1213
2003
Sobolev, N.V.Malygina, E.V., Pokhilenko, N.P., Sobolev, N.V.Coarse peridotite xenoliths of Udachnaya kimberlite pipe, Yakutia: garnetization of peridotites of the central Siberian platform8 IKC Program, Session 6, POSTER abstractRussia, Siberia, YakutiaMantle petrology Deposit - Udachnaya
DS200412-1335
2004
Sobolev, N.V.Misra, K.C., Anand, M., Taylor, L.A., Sobolev, N.V.Multi stage metasomatism of Diamondiferous eclogite xenoliths from the Udachnaya kimberlite pipe, Yakutia, Siberia.Contributions to Mineralogy and Petrology, Vol. 146, 6, pp. 696-714.Russia, Siberia, YakutiaDeposit - Udachnaya
DS200412-1492
2004
Sobolev, N.V.Palyanov, Yu.N., Borzdov, Y.M., Kupriyanov, I.N., Sobolev, N.V.Diamond and graphite crystallization from pentlandite melt at HPHT conditions.Lithos, ABSTRACTS only, Vol. 73, p. S82. abstractTechnologyDiamond nucleation
DS200412-1493
2003
Sobolev, N.V.Palyanov, Yu.N., Borzdov, Yu.M., Ovchinnikov, I.Yu., Sobolev, N.V.Experimental study of the interaction between pentlandite melt and carbon at mantle Pt parameters: condition of diamond and grapDoklady Earth Sciences, Vol. 392, Sept-Oct. pp. 1026-29.MantleCrystallography
DS200412-1494
2004
Sobolev, N.V.Palyanov, Yu.N.,Sokol, A.G., Tomilenko, A.A., Sobolev, N.V.Conditions of diamond formation under carbonate silicate interaction.Lithos, ABSTRACTS only, Vol. 73, p. S83. abstractTechnologyDiamond nucleation
DS200412-1561
2003
Sobolev, N.V.Pokhilenko, N.P., Agashev, A.M., McDonald, J.A., Sobolev, N.V., Mityukhin, S.I., Vavilov, M.A., Yanygin, Y.T.Kimberlites of the Nakyn field, Siberia and the Snap Lake King Lake dyke system, Slave Craton, Canada: a new variety of kimberli8 IKC Program, Session 7, POSTER abstractCanada, Northwest TerritoriesKimberlite petrogenesis Deposit - Snap Lake, King Lake
DS200412-1564
2003
Sobolev, N.V.Pokhilenko, N.P., McDonald, J.A., Sobolev, N.V., Reutsky, V.N., Hall, A.E., Logvinova, A.M., Reimers, L.F.Crystalline inclusions and C isotope composition of diamonds from the Snap lake/King Lake kimberlite dyke system: evidence for a8 IKC Program, Session 3, AbstractCanada, Northwest TerritoriesDiamonds - geochronology Deposit - Snap Lake
DS200412-1566
2004
Sobolev, N.V.Pokhilenko, N.P., Sobolev, N.V., Reutsky, V.N., Hall, A.E., Taylor, L.A.Crystalline inclusions and C isotope ratios in diamonds from the Snap Lake/King Lake kimberlite dyke system: evidence of ultradeLithos, Vol. 77, 1-4, Sept. pp. 57-67.Canada, Northwest TerritoriesDiamond inclusions, Carbon isotopes
DS200412-1592
2004
Sobolev, N.V.Promprated, P., Taylor, L.A., Anand, M., Floss, C., Sobolev, N.V., Pokhilenko, N.P.Multiple mineral inclusions in diamonds from the Snap Lake/King Lake kimberlite dike, Slave Craton: a trace element perspective.Lithos, Vol. 77, 1-4, Sept. pp. 69-81.Canada, Northwest TerritoriesDiamond inclusions, trace element, REE, in situ analysi
DS200412-1748
2004
Sobolev, N.V.Schertl, H.P., Neuser, R.D., Sobolev, N.V., Shatsky, V.S.UHP metamorphic rocks from Dora Maira Western Alps and Kokchetav Kazakhstan: new insights using cathodluminescence petrography.European Journal of Mineralogy, Vol. 16, 1, pp. 49-57.KazakhstanUHP
DS200412-1798
2003
Sobolev, N.V.Sharygin, V.V., Golovin, A.V., Pokhilenko, N.P., Sobolev, N.V.Djerfisherite in unaltered kimberlites of the Udachnaya East pipe, Yakutia.Doklady Earth Sciences, Vol. 390, 4, May-June pp. 554-8.RussiaMineralogy Deposit - Udachnaya
DS200412-1869
2004
Sobolev, N.V.Sobolev, N.V., Logvinova, A.M., Zedgenizov, D.A., Seryotkin, Y.V., Tefimova, E.S., Floss, C., Taylor, L.A.Mineral inclusions in microdiamonds and macrodiamonds from kimberlites of Yakutia: a comparative study.Lithos, Vol. 77, 1-4, Sept. pp. 225-242.Russia, Yakutia, SiberiaDiamond inclusions, craton, eclogite, peridotite
DS200412-1870
2003
Sobolev, N.V.Sobolev, N.V., Logvinova, A.M., Zedgenizov, D.A., Yefimova, E.S.Mineral inclusions in microdiamonds and macrodiamonds from kimberlites of Yakutia: a comparative study.8 IKC Program, Session 3, AbstractRussia, Yakutia, SiberiaDiamonds - inclusions
DS200412-1871
2003
Sobolev, N.V.Sobolev, N.V., Shatsky, V.S., Liou, J.G., Zhang, R.Y., Hwang, Shen, Chu, Yui, Zayachkovsky, KasymovAn origin of microdiamonds in metamorphic rocks of the Kokchetav Massif, northern Kazakhstan. US Russian civilian research andEpisodes, December, pp. 290-294.Russia, KazakhstanGenesis - microdiamonds
DS200412-1973
2003
Sobolev, N.V.Taylor, L.A., Anand, M., Promprated, P., Floss, C., Sobolev, N.V.The significance of mineral inclusions in large diamonds from Yakutia, Russia.American Mineralogist, Vol. 88, 5/6, pp. 912-928.Russia, YakutiaDiamond - inclusions, protogenetic Deposit - Udachnaya, Mir, Aikhal
DS200412-1974
2003
Sobolev, N.V.Taylor, L.A., Snyder, G.A., Keller, R., Remley, D.A., Anand,M., Wiesli, R., Valley, J., Sobolev, N.V.Petrogenesis of Group A eclogites and websterites: evidence from the Obnazhennaya kimberlite, Yakutia.Contributions to Mineralogy and Petrology, Vol. 145, pp. 424-443.Russia, YakutiaPetrology, genesis Deposit - Obnazhennaya
DS200412-2027
2004
Sobolev, N.V.Urakaev, F.Kh., Palyanov, Yu.N., DShevchenko, V.S., Sobolev, N.V.Abrasive reactive Mechano chemical synthesis of cohenite with the application of diamond.Doklady Earth Sciences, Vol. 394, 2, pp. 214-218.TechnologyPetrology - experimental
DS200412-2199
2004
Sobolev, N.V.Zedgenizov, D.A., Kagi, H., Shatsky, V.S., Sobolev, N.V.Carbonatitic melts in cuboid diamonds from the Udachnaya kimberlite pipe ( Yukatia): evidence from vibrational spectroscopy.Mineralogical Magazine, Vol. 6, 1, pp. 61-73.Russia, YakutiaDiamond morphology
DS200512-0129
2004
Sobolev, N.V.Buzlukova, L.V., Shatsky, V.S., Sobolev, N.V.Specific structure of the lowermost Earth's crust at the Zagadochnaya kimberlite pipe.Russian Geology and Geophysics, Vol. 45, 8, pp. 942-959.Russia, YakutiaStructure - Zagadochnaya
DS200512-0454
2005
Sobolev, N.V.Hwang, S.L., Shen, P., Chu, H-T., Yui, T-F., Liou, J.G., Sobolev, N.V., Shatsky, V.S.Crust derived potassic fluid in metamorphic microdiamond.Earth and Planetary Science Letters, Vol. 231, 3-4, March 15, pp. 295-306.Russia, SiberiaKokchetav massif
DS200512-0455
2004
Sobolev, N.V.Hwang, S.L., Shen, P., Chu, H-T., Yui, T-F, Liou, J.G., Sobolev, N.V., Zhang, R-Y., Shatsky, V.S., ZayachkovskyKokchetavite: a new potassium feldspar polymorph from the Kokchetav ultrahigh pressure terrane.Contributions to Mineralogy and Petrology, Vol. 148, 3, pp. 380-RussiaUHP
DS200512-0495
2004
Sobolev, N.V.Kamenetsky, M.B., Sobolev, A.V., Kamenetsky, V.S., Maas, R., Danyushevsky, L.V., Thomas, R., Pokhilenko, N.P., Sobolev, N.V.Kimberlite melts rich in alkali chlorides and carbonates: a potent metasomatic agent in the mantle.Geology, Vol. 32, 10, Oct. pp. 845-848.Russia, Siberia, YakutiaUdachnaya, Group I, volatiles, metasomatism, inclusions
DS200512-0666
2005
Sobolev, N.V.Maas, R., Kamenetsky, M.B., Sobolev, A.V., Kamenetsky, V.S., Sobolev, N.V.Sr Nd Pb isotope evidence for a mantle origin of alkali chlorides and carbonates in the Udachnaya kimberlite, Siberia.Geology, Vol. 33, 7, July, pp. 549-552.Russia, SiberiaGeochronology - Udachnaya
DS200512-0817
2005
Sobolev, N.V.Palyanov, Y.N., Sokol, A.G., Tomilenko, A.A., Sobolev, N.V.Conditions of diamond formation through carbonate silicate interaction.European Journal of Mineralogy, Vol. 17, 2, pp. 207-214.Diamond genesis
DS200512-0968
2005
Sobolev, N.V.Shatsky, V.S., Zedgenizov, D.A., Ragozin, A.L., Mityukhin, S.I., Sobolev, N.V.Evidence for metasomatic formation of diamond in eclogite xenolith from the Udachnaya kimberlite pipe.Doklady Earth Sciences, Vol. 402, 4, pp. 587-90.Russia, YakutiaMetasomatism
DS200512-1018
2004
Sobolev, N.V.Sobolev, N.V., Loginova, A.M.Pyrope inclusions in chrome spinels from kimberlites and lamproites and their significance for estimation of the paragenetic assemblage and formation depth.Doklady Earth Sciences, Vol. 399, Oct-Nov. pp. 1074-8.RussiaMineralogy - pyrope
DS200512-1019
2004
Sobolev, N.V.Sobolev, N.V., Logvinova, A.M.Significance of accessory chrome spinel in identifying serpentinite paragenesis.International Geology Review, Vol. 47, 1, pp. 58-64.Russia, YakutiaMineralogy - Udabchnaya
DS200512-1020
2004
Sobolev, N.V.Sobolev, N.V., Logvinova, O.V.Pyrope inclusions in chrome spinels from kimberlites and lamproites and their significance for estimation of the paragenetic assemblage and formation depth.Doklady Earth Sciences, Vol. 399, 8, pp.1074-1079.MantleMineralogy - inclusions
DS200612-0004
2006
Sobolev, N.V.Agashev, A.M., Pokhilenko, N.P., Malkovets, V.G., Sobolev, N.V.Sm Nd isotopic system in garnet megacrysts from the Udachnaya kimberlite pipe (Yakutia) and petrogenesis of kimberlites.Doklady Earth Sciences, Vol. 407A, 3, pp. 491-494.Russia, YakutiaGeochronology - Udachnaya
DS200612-0613
2006
Sobolev, N.V.Hwang, S.L., Chu, H-T., Yui, T-F., Shen, P., Schertl, H-P., Liou, J.G., Sobolev, N.V.Nanometer size P/K rich silica glass (former melt) inclusions in microdiamond from the gneisses of Kokchetav and Erzgebirge massifs: diversified...Earth and Planetary Science Letters, in pressRussia, Europe, GermanyUHP metamorphic microdiamonds, host rock buffering
DS200612-0832
2005
Sobolev, N.V.Logvinova, A.M., Taylor, L.A., Floss, C., Sobolev, N.V.Geochemistry of multiple diamond inclusions of harzburgite garnets as examined in situ.International Geology Review, Vol. 47, 12, Dec. pp. 1223-1233.RussiaDiamond inclusions
DS200612-0833
2006
Sobolev, N.V.Logvinova, A.M., Wirth, R., Sobolev, N.V.Nanometric sized mineral and fluid inclusions in cloudy Siberian diamonds: new insights on diamond formation. Internationalnaya, Yubileynaya.International Mineralogical Association 19th. General Meeting, held Kobe, Japan July 23-28 2006, Abstract p. 137.Russia, SiberiaDiamond inclusions
DS200612-1022
2006
Sobolev, N.V.Palyanov, Yu.N., Borzdov, Yu.M., Khokhryakov, A.F., Kupriyanov, I.N., Sobolev, N.V.Sulfide melts - graphite interaction at HPHT conditions: implications for diamond genesis.Earth and Planetary Science Letters, Vol. 250, 1-2, Oct. 15, pp. 269-280.MantleUHP, diamond genesis, carbon
DS200612-1023
2005
Sobolev, N.V.Palynaov, Y.N., Sokol, A.G., Sobolev, N.V.Experimental modeling of mantle diamond forming processes.Russian Geology and Geophysics, Vol. 46, 12, pp. 1271-1284.MantleDiamond genesis
DS200612-1195
2006
Sobolev, N.V.Rylov, G.M., Fedorova, E.N., Sobolev, N.V.Study of the internal structure of imperfect diamond crystals by the Lane-SR method.Russian Geology and Geophysics, Vol. 47, 2, pp. 249-256.TechnologyDiamond morphology
DS200612-1271
2005
Sobolev, N.V.Shatsky, V.S., Palyanov, Y.N., Sokol, A.G., Tomilenko, A.A., Sobolev, N.V.Diamond formation in UHP dolomite marbles and garnet pyroxene rocks of the Kokchetav Massif, northern Kazakstan: natural and experimental evidence.International Geology Review, Vol. 47, 10, pp. 999-1010.RussiaUHP
DS200612-1272
2006
Sobolev, N.V.Shatsky, V.S., Ragozin, A.J., Sobolev, N.V.Some aspects of metamorphic evolution of ultrahigh pressure calc-silicate rocks.Russian Geology and Geophysics, Vol. 47, 1 pp. 105-119.MantleUHP
DS200612-1328
2006
Sobolev, N.V.Sobolev, N.V.The new Komsomolskaya mine in Yakutia, Russia: unique features of its diamonds.GIA Gemological Research Conference abstract volume, Held August 26-27, p. 28. 1/2p.Russia, YakutiaDiamond morphology, crystallography
DS200612-1329
2006
Sobolev, N.V.Sobolev, N.V.Coesite as an indicator of ultrahigh pressures in continental lithosphere.Russian Geology and Geophysics, Vol. 47, 1 pp. 94-104.MantleUHP - coesite
DS200612-1330
2006
Sobolev, N.V.Sobolev, N.V., Logvinova, A.M., Zedgenizov, D.A., Kuzmin, D.V., Sobolev, A.V.Olivine inclusions in Siberian diamonds: high precision approach to trace elements.International Mineralogical Association 19th. General Meeting, held Kobe, Japan July 23-28 2006, Abstract p. 137.Russia, SiberiaGeochemistry - mineral inclusiosn
DS200612-1331
2006
Sobolev, N.V.Sobolev, N.V., Schertl, H.P., Neuser, R.D.Composition and paragenesis of garnets from ultrahigh pressure calc-silicate metamorphic rocks of the Kokchetav massif.Russian Geology and Geophysics, Vol. 47, 4, pp. 519-Russia, KazakhstanUHP - geochemistry garnets
DS200612-1585
2006
Sobolev, N.V.Zegrenizov, D.A., Harte, B., Shatsky, V.S., Politov, A.A., Rylov, G.M., Sobolev, N.V.Directional chemical variations in diamonds showing octahedral following cuboid growth.Contributions to Mineralogy and Petrology, Vol. 151, 1, Jan. pp. 45-57.Russia, YakutiaMineral chemistry, subduction
DS200712-0799
2007
Sobolev, N.V.Palynaov, Y.N., Shatsky, V.S., Sobolev, N.V., Sokol, A.G.The role of mantle uptrapotassic fluids in diamond formation.Proceedings of National Academy of Sciences USA, Vol. 104, 22, pp. 9122-9127. IngentaMantleDiamond genesis
DS200712-0922
2007
Sobolev, N.V.Rylov, G.M., Fedorova, E.N., Logvinova, A.M., Pokhilenko, N.P., Kulipanov, G.N., Sobolev, N.V.The peculiarities of natural plastically deformed diamond crystals from Internationalnaya pipe, Yakutia.Nuclear Instruments and Methods in Physics Research Section A., Vol. 575, 1-2, pp. 152-154.RussiaDiamond morphology
DS200712-1010
2007
Sobolev, N.V.Sobolev, N.V., Schertl, H-P., Neuser, R.D., Shatsky, V.S.Relict unusually low iron pyrope grossular garnets from UHPM calc-silicate rocks of the Kochetav Massif, Kazakhstan.International Geology Review, Vol. 49, 8, pp. 717-731.Russia, KazakhstanUHP
DS200712-1042
2007
Sobolev, N.V.Stepanov, A.S., Shatsky, V.S., Zedgenizov, D.A., Sobolev, N.V.Causes of variations in morphology and impurities of diamonds from the Udachnaya pipe eclogite.Russian Geology and Geophysics, Vol. 48, no. 9, pp. 758-769.Russia, YakutiaDiamond morphology
DS200812-0002
2008
Sobolev, N.V.Afanasev, V.P., Nikolenko, E.I., Tychikov, N.S., Titov, A.T., Tolstov, A.V., Kornilova, V.P., Sobolev, N.V.Mechanical abrasion of kimberlite indicator minerals: experimental investigations.Russian Geology and Geophysics, Vol. 49, 2, pp. 91-97.TechnologyMineralogy
DS200812-0004
2008
Sobolev, N.V.Agashev, A.M., Pokhilenko, N.P., Takazawa, E., McDonald, J.A., Vavilov, M.A., Watanabe, T., Sobolev, N.V.Primary melting sequence of a deep ( >250 km) lithospheric mantle as recorded in the geochemistry of kimberlite carbonatite assemblages, Snap Lake dyke system, Canada.Chemical Geology, Vol. 255, 3-4, pp. 317-328.Canada, Northwest TerritoriesDeposit - Snap Lake
DS200812-0683
2008
Sobolev, N.V.Logvinova, A.M., Wirth, R., Federova, E.N., Sobolev, N.V.Nanometre-sized mineral and fluid inclusions in cloudy Siberian diamonds: new insights on diamond formation.European Journal of Mineralogy, Vol. 20, no. 3, pp. 317-331.Russia, SiberiaDiamond genesis
DS200812-0684
2008
Sobolev, N.V.Logvinova, A.M., Wirth, R., Fedorova, E.N., Sobolev, N.V.Multi phase assemblages of nanometer sized inclusions in cloudy Siberian diamonds: evidence from TEM.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., 2008 pp. 53-70.Russia, SiberiaDiamond inclusions
DS200812-1046
2008
Sobolev, N.V.Sharygin, V.V., Sobolev, N.V., Channer, D.M.DeR.Oscillatory zoned crystals of the pyrochlore group minerals from the Guaniamo kimberlites, Venezuela: first occurrence of pyrochlore in kimberlite.9IKC.com, 3p. extended abstractSouth America, VenezuelaDeposit - Guaniamo
DS200812-1092
2008
Sobolev, N.V.Sobolev, N.V., Logvinova, A.M., Zedgenizov, D.A., Pokhilenko, N.P., Kuzmin, D.V., Sobolev, A.V.Olivine inclusions in Siberian diamonds: high precision approach to minor elements.European Journal of Mineralogy, Vol. 20, no. 3, pp. 305-315.Russia, SiberiaDiamond inclusions
DS200912-0003
2009
Sobolev, N.V.Afanasyev, V.P., Agashev, A.M., Orihashi, Y., Pokhilenko, N.P., Sobolev, N.V.Paleozoic U Pb age of rutile inclusions in diamonds of the V-VII variety from placers of the northeast Siberian platform.Doklady Earth Sciences, Vol. 428, 1, pp. 1151-1155.RussiaDiamond inclusions
DS200912-0434
2009
Sobolev, N.V.Lenaz, D., Logvinova, A.M., Princivalle, F., Sobolev, N.V.Structural parameters of chromite included in diamond and kimberlites from Siberia: a new tool for discriminating ultramafic source.American Mineralogist, Vol. 94, 7, pp. 1067-1070.Russia, SiberiaDiamond inclusions
DS200912-0708
2009
Sobolev, N.V.Sobolev, N.V., Logvinova, A.M., Zedgenizov, D.A., Pokhilenko, N.P., Malygina, E.V., Kuzmin, D.V., Sobolev, A.V.Petrogenetic significance of minor elements in olivines from diamonds and peridotite xenoliths from kimberlites of Yakutia.Lithos, In press - available 38p.Russia, YakutiaDiamond inclusions
DS200912-0766
2009
Sobolev, N.V.Tomilenko, A.A., Kovyazin, S.V., Pokhilenko, L.N., Sobolev, N.V.Primary hydrocarbon inclusions in garnet of Diamondiferous eclogite from the Udachnaya kimberlite pipe, Yakutia.Doklady Earth Sciences, Vol. 427, 4, pp. 695-8.Russia, YakutiaDeposit - Udachnaya
DS201012-0335
2009
Sobolev, N.V.Kamenetsky, V.S., Kamenetsky, M.B., Sobolev, A.V., Golovin, A.V., Sharyginb, V.V., Pokhilenko, N.P., Sobolev, N.V.Can pyroxenes be liquidus minerals in the kimberlite magma?Lithos, Vol. 112 S pp. 213-235.MantleChemistry
DS201012-0433
2010
Sobolev, N.V.Lenaz, D., Skogby, H., Logvinova, A.M., Princivalle, F., Sobolev, N.V.Fe3+ Fe tot ratio in the mantle: a micro-Mossbauer study of chromites included in diamond and kimberlites.International Mineralogical Association meeting August Budapest, abstract p. 431.Russia, YakutiaOxidation state
DS201012-0690
2009
Sobolev, N.V.Sharygin, V.V., Sobolev, N.V., Channer, D.M.DeR.Oscillatory zoned crystals of pyrochlore group minerals from the Guaniamo kimberlites, Venezuela.Lithos, Vol. 112 S pp. 976-985.South America, VenezuelaMineral chemistry
DS201012-0734
2009
Sobolev, N.V.Sobolev, N.V.Preface: Contribution of Vladimir S. Sobolev to the study of petrology of the lithosphere and diamond genesis.Russian Geology and Geophysics, Vol. 50, 12, pp. 995-998.TechnologyHistory
DS201012-0735
2009
Sobolev, N.V.Sobolev, N.V., Logvinova, A.M., Efimova, E.S.Syngenetic phlogopite inclusions in kimberlite hosted diamonds: implications for role of volatiles in diamond formation.Russian Geology and Geophysics, Vol. 50, 12, pp. 1234-1248.MantleDiamond genesis
DS201012-0804
2009
Sobolev, N.V.Turkin, A.I., Sobolev, N.V.Pyrope knorringite garnets: overview of experimental dat a and natural parageneses.Russian Geology and Geophysics, Vol. 50, 12, pp. 1169-1182.TechnologyGarnet
DS201112-0982
2011
Sobolev, N.V.Sobolev, N.V., Schertl, H-P., Valley, J.W., Page, F.Z., Kita, N.T., Spicuzza, M.J., Neuser, R.D., Logvinova, A.M.Oxygen isotope variations of garnets and clinopyroxenes in a layered Diamondiferous calcsilicate rock from Kokchetav Massif, Kazakhstan: a window into geochemicalContributions to Mineralogy and Petrology, Vol. 162, 5, pp.1079-1092.Russia, KazakhstanDeeply subducted UHPM rocks
DS201112-1050
2011
Sobolev, N.V.Tomilenko, A.A., Kovyazin, S.V., Pokhilenko, L.N., Sobolev, N.V.Silicate globules in kyanite from grospydites of the Zagadochnaya kimberlite pipe, Yakutia: the problem of origin.Doklady Earth Sciences, Vol. 436, 1, pp. 98-101.Russia, YakutiaPetrology
DS201112-1173
2011
Sobolev, N.V.Ziberna, L., Nimis, P., Zanetti, A., Sobolev, N.V., Marzoli, A.Geochemistry of mantle microxenoliths from Zagadochnaya kimberlite, Yakutia, Russia.Goldschmidt Conference 2011, abstract p.2283.Russia, YakutiaNarren Type II kimberlite
DS201212-0061
2012
Sobolev, N.V.Bataleva, Yu.V., Palyanov, Yu.N., Sokol, A.G., Borzdov, Yu.M., Sobolev, N.V.Conditions of formation of Cr-pyrope and escolaite during mantle metasomatism: experimental modeling.Doklady Earth Sciences, Vol. 442, 1, pp. 76-80.TechnologyMetasomatism
DS201212-0197
2012
Sobolev, N.V.Fedorova, E.N., Logvinova, A.M., Mashkovtsev, R., Sobolev, N.V.Internal structure and color of the natural plastically deformed diamonds from the Internationalnaya kimberlite pipe, Yakutia.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, YakutiaDeposit - Internationnaya
DS201212-0417
2012
Sobolev, N.V.Logvinova, A.I., Wirth, R., Sobolev, N.V., Taylor, L.A.Multi-phase sub-micrometer silicate sulfide and fluid inclusions in diamonds: expressions of metasomatism evidenced in peridotites and eclogites.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractRussiaMetasomatism - diamond inclusions
DS201212-0632
2012
Sobolev, N.V.Selyatitskii, A.Yu., Reverdatto, V.V., Kuzmin, D.V., Sobolev, N.V.Minor elements in unusual olivines from high pressure peridotites of the Kokchetav Massif (Northern Kazakhstan).Doklady Earth Sciences, Vol. 445, 2, pp. 1015-1020.Russia, KazakhstanDeposit - Kokchetav
DS201212-0649
2012
Sobolev, N.V.Shirey, S.B., Cartigny, P., Frost, D.J., Nestola, F., Nimis, P., Pearson, D.G., Sobolev, N.V., Walter, M.J.Diamonds and the geology of Earth mantle carbon.GSA Annual Meeting, Paper no. 211-5, abstractMantleSubduction
DS201212-0683
2012
Sobolev, N.V.Sobolev, N.V., Sobolev, A.V., Tomilenko, A.A., Kovyazin, S.V., Kuzmin, D.V.Pyrope lherzolite assemblage of Ti bearing olivine macrocryst from Udachanya ultrafresh kimberlite, Yakutia, Russia.emc2012 @ uni-frankfurt.de, 1p. AbstractRussiaDeposit - Udachnaya
DS201212-0685
2013
Sobolev, N.V.Sokol, A.G., Kupriyanov, I.N., Palyanov, Y.N., Kruk, A.N., Sobolev, N.V.Melting experiments on the Udachnaya kimberlite at 6.3-7.5 Gpa: implications for the role of H2O in magma generation and formation of hydrous olivine.Geochimica et Cosmochimica Acta, Vol. 101, pp. 133-155.RussiaDeposit - Udachnaya
DS201212-0686
2012
Sobolev, N.V.Sokol, A.G., Kupriyanov, I.N., Palyanov, Yu.N., Kruk, A.N., Sobolev, N.V.Melting experiments on the Udachnaya kimberlite at 6.3-7.5 Gpa: implications for the role of H2O in magma generation and formation of hydrous olivine.emc2012 @ uni-frankfurt.de, 1p. AbstractRussiaDeposit - Udachnaya
DS201212-0817
2012
Sobolev, N.V.Zhang, R.Y.,Liou, J.G., Omori, S., Sobolev, N.V., Shatsky, V.S., Iizuka, C.H-O.Tale of the Kulet eclogite from the Koketchev Massive, Kazakhstan: initial tectonic setting and transition from amphibolite to eclogite.Journal of Metamorphic Geology, in press availableRussia, KazakhstanEclogite
DS201312-0152
2013
Sobolev, N.V.Chepurov, A.A., Tychikov, N.S., Sobolev, N.V.Experimental modeling of the conditions of crystallization of subcalcium chromium pyropes.Doklady Earth Sciences, Vol. 452, 2, pp. 1062-1066.RussiaDeposit - Udachnaya
DS201312-0153
2012
Sobolev, N.V.Chepurov, A.I., Sonin, V.M., Chepurov, A.A., Zhimulev, E.I., Kosolobov, S.S., Sobolev, N.V.Diamond interaction with ultradispersed particles of iron in a hydrogene environment: surface micromorphology.Doklady Earth Sciences, Vol. 447, 1, pp. 1284-1287.TechnologyMineralogy
DS201312-0489
2013
Sobolev, N.V.Klein-BenDavid, O., Pearson, D.G., Nowell, G.M., Ottley, C., McNeill, J.C.R., Logvinova, A., Sobolev, N.V.The sources and time integrated evolution of diamond forming fluid - trace elements and Sr isotopic evidence.Geochimica et Cosmochimica Acta, Vol. 125, pp. 146-169.Russia, Africa, Democratic Republic of Congo, Canada, Northwest TerritoriesFibrous diamonds, HDF, Diavik, Udachnaya
DS201312-0531
2013
Sobolev, N.V.Lenaz, D., Skogby, H., Logvinova, A.M., Sobolev, N.V., Princivalle, F.A micro-Mossbauer study of chromites included in diamond and other mantle related rocks.Physics and Chemistry of Minerals, Vol. 40, 9, pp. 671-679.Russia, SiberiaSpectroscopy - diamond
DS201312-0815
2012
Sobolev, N.V.Shirey, S.B., Cartigny, P.,Frost, D.J., Nestola, F., Pearson, D.G., Sobolev, N.V., Walter, M.J.Diamonds and the geology of Earth mantle carbonGeological Society of America Annual Meeting abstract, Paper 211-5, 1/2p. AbstractMantleCarbon
DS201312-0816
2013
Sobolev, N.V.Shirey, S.B., Cartigny, P., Frost, D.J., Keshav, S., Nestola, F., Nimis, P., Pearson, D.G., Sobolev, N.V., Walter, M.J.Diamonds and the geology of mantle carbon.Reviews in Mineralogy and Geochemistry, Vol. 75, pp. 355-421.MantleDiamond genesis
DS201312-0864
2013
Sobolev, N.V.Sokol,A.G.,Kupriyanov, I.N., Palyanov, Y.N., Kruk, A.N., Sobolev, N.V.Melting experiments in the Udachnaya kimberlite at 6.3-7.5 Gpa: implications for the role of H2O in magma generation and formation of hydrous olivine.Geochimica et Cosmochimica Acta, Vol. 101, Jn. 15, pp. 133-155.RussiaDeposit - Udachnaya
DS201312-0869
2012
Sobolev, N.V.Sonin, V.M., Chepurov, A.A., Shcheglov, D.V., Kosolobov, S.S., Logvinova, A.M., Chepurov, A.I., Latyshev, A.V., Sobolev, N.V.Study of the surface of natural diamonds by the method of atomic force microscopy.Doklady Earth Sciences, Vol. 447, 2, pp. 1314-1316.TechnologyDiamond morphology
DS201312-1022
2013
Sobolev, N.V.Ziberna, L., Nimis, P., Zanetti, A., Marzoli, A., Sobolev, N.V.Metasomatic processes in the central Siberian cratonic mantle: evidence from garnet xenocrysts from the Zagadochnaya kimberlite.Journal of Petrology, Vol. 54, pp. 2379-2409.Russia, SiberiaDeposit - Zagadochnaya
DS201412-0101
2014
Sobolev, N.V.Carmody, L., Taylor, L.A., Thaisen, K.G., Tychkov, N., Bodnar, R.J., Sobolev, N.V., Poikhilenko, L.N., Poikilenko, N.P.Ilmenite as a diamond indicator mineral in the Siberian craton: a tool to predict diamond potential.Economic Geology, Vol. 109, no. 3, pp. 775-783.RussiaIlmenite, chemistry
DS201412-0374
2014
Sobolev, N.V.Howarth, G.H., Sobolev, N.V., Pernet-Fisher, J.F., Barry, P.H., Penumado, D., Puplampu, S., Ketcham, R.A., Maisano, J.A., Taylor, D., Taylor, L.A.The secondary origin of diamonds: multi-modal radiation tomography of Diamondiferous mantle eclogites.International Geology Review, Vol. 56, 9, pp. 1172-1180.Russia, Siberia3D
DS201412-0524
2014
Sobolev, N.V.Logvinova, A., Wirth, R., Taylor, L.A., Sobolev, N.V.Aragonite, magnesite and dolomite inclusions in Yakutian diamonds: TEM observations.V.S. Sobolev Institute of Geology and Mineralogy Siberian Branch Russian Academy of Sciences International Symposium Advances in high pressure research: breaking scales and horizons ( Courtesy of N. Poikilenko), Held Sept. 22-26, 1p. AbstractRussia, YakutiaDeposit - Komsomolskaya, Yubileinaya, Udachnaya
DS201412-0658
2014
Sobolev, N.V.Palyanov, Y.N., Bataleva, Y.V., Sokol, A.G., Borzdov, Y.M., Kupriyanov, I.N., Reutsky, V.N., Sobolev, N.V.Mantle slab interaction and redox mechanism of diamond formation.Proceedings of National Academy of Science USA, Vol. 110, 51, Dec. 17, pp.MantleUHP, deep carbon cycle
DS201412-0862
2013
Sobolev, N.V.Sobolev, N.V., Logvinova, A.M., Efimova, E.S.Inclusions of Mn-rich eclogitic garnets in diamonds: evidence for recycling of the Earth's crust.Doklady Earth Sciences, Vol. 451, 1, pp. 1165-1167.TechnologyDiamond morphology
DS201412-0863
2014
Sobolev, N.V.Sobolev, N.V., Sobolev, A.V., Tomilenko, A.A., Kovyazin, S.V., Batanova, V.G., Kuzmin, D.V.Paragenesis and origin of olivine macrocrysts from Udachnaya-East hypabyssal kimberlite, Yakutia, Russia.V.S. Sobolev Institute of Geology and Mineralogy Siberian Branch Russian Academy of Sciences International Symposium Advances in high pressure research: breaking scales and horizons ( Courtesy of N. Poikilenko), Held Sept. 22-26, 2p. AbstractRussia, YakutiaDeposit - Udachnaya-East
DS201502-0074
2015
Sobolev, N.V.Logvinova, A.M., Taylor, L.A., Fedorova, E.N., Yelisseyev, A.P., Wirth, R., Howarth, G., Reutsky, V.N., Sobolev, N.V.A unique Diamondiferous peridoite xenolith from the Udachnaya kimberlite pipe, Yakutia: role of subduction in diamond formation.Russian Geology and Geophysics, Vol. 56, 1, pp. 306-320.Russia, YakutiaDeposit - Udachnaya
DS201502-0086
2015
Sobolev, N.V.Neuser, R.D., Schertl, H-P., Logvinova, A.M., Sobolev, N.V.An EBSD study of olivine inclusions in Siberian diamonds: evidence for syngenetic growth?Russian Geology and Geophysics, Vol. 56, 1, pp. 321-329.RussiaDiamond morphology
DS201502-0101
2015
Sobolev, N.V.Shertl, H.P., Neuser, R.D., Logvinova, A.M., Wirth, R., Sobolev, N.V.Cathodluminescence microscopy of the Kokchetav ultra high pressure calcsilicate rocks: what can we learn from silicates, carbon hosting minerals and diamond?Russian Geology and Geophysics, Vol. 56, 1-2, pp. 100-112.Russia, KazakhstanKokchetav massif
DS201502-0103
2015
Sobolev, N.V.Sobolev, N.V., Dobretsov, N.I., Ohtani, E., Taylor, L.A., Schertl, H-P., Palyanov, Yu.N.Problems related to crystallogenesis and the deep carbon cycle.Russian Geology and Geophysics, Vol. 56, 1-2, pp. 1-12.MantleCarbon cycle
DS201502-0104
2015
Sobolev, N.V.Sobolev, N.V., Sobolev, A.V., Tomilenko, A.A., Kovyazin, S.V., Batanova, V.G., Kuzmin, D.V.Paragenesis and complex zoning of olivine macrocrysts from unaltered kimberlite of the Udachnaya-East pipe, Yakutia: relationship with the kimberlite formation conditions and evolution.Russian Geology and Geophysics, Vol. 56, 1, pp. 260-279.Russia, YakutiaDeposit - Udachnaya-East
DS201504-0202
2015
Sobolev, N.V.Howarth, G.H., Sobolev, N.V., Pernet-Fisher, J.F., Ketcham, R.A., Maisano, J.A., Pokhilenko, L.N., Taylor, D.3-D X-ray tomography of Diamondiferous mantle eclogite xenoliths, Siberia: a review.Journal of Asian Earth Sciences, Vol. 101, 1, pp. 39-67.RussiaDeposit - Udachnaya
DS201509-0427
2015
Sobolev, N.V.Shatsky, V.S., Skuzovatov, S.Yu., Ragozin, A.L., Sobolev, N.V.Mobility of elements in a continental subduction zone: evidence from the UHP metamorphic complex of the Kokchetav massif.Russian Geology and Geophysics, Vol. 56, pp. 1016-1034.RussiaKokchetav massif

Abstract: We studied clastics of high-alumina garnet-kyanite-mica schists and garnet-kyanite-quartz granofelses, including diamond-bearing ones, found in the eluvial sediments near Lake Barchi. In contents of major elements the studied rocks correspond to argillaceous shales. The garnet-kyanite-quartz granofelses are poorer in K (0.49-1.35 wt.% K2O) than the garnet-kyanite-mica schists (4.9-2.2 wt.% K2O) but have the same contents of other major components. The REE patterns of most of the garnet-kyanite-phengite schists are similar to those of the Post-Archean Australian Shale (PAAS) (xLa/Yb = 13). All garnet-kyanite-quartz rocks are much stronger depleted in LREE (xLa/Yb = 1.4) and other incompatible elements. Our studies show that allanite and monazite are the main concentrators of LREE and Th in the garnet-kyanite-phengite rocks of the Barchi site. Monazite, occurring as inclusions in garnet, contains not only LREE but also Th, U, and Pb. Rutile of the nondepleted rocks is enriched in Fe and Nb impurities only. The garnet-kyanite-quartz granofelses bear rutile, apatite, and xenotime as accessory phases. Rutile of the depleted rocks shows wide variations in contents of Nb, Ta, and V impurities. In places, the contents of Nb and Ta reach 10.5 and 2.3 wt.%, respectively. The rutile decomposes into rutile with Nb (1.4 wt.%) and Fe (0.87 wt.%) impurities and titanium oxide rich in Fe (6.61 wt.%), Nb (up to 20.8 wt.%), and Ta (up to 2.81%) impurities. Based on the measured contents of incompatible elements in differently depleted high-alumina rocks, the following series of element mobility during UHP metamorphism has been established: Th > Ce > La > Pr > Nd > K > Ba > Rb > Cs > Sm > Eu. The contents of U, P, and Zr in the depleted rocks are similar to those in the nondepleted rocks. The studies have shown that metapelites subducted to the depths with diamond stability conditions can be depleted to different degrees. This might be either due to their exhumation from different depths of the subduction zone or to the presence of an external source of water controlling the temperature of dissolution of phengite and the formation of supercritical fluid/melt.
DS201509-0428
2015
Sobolev, N.V.Sokol, A.G., Kruk, A.N., Chebotarev, D.A., Palyanov, Yu.N., Sobolev, N.V.The composition of garnet as an indicator of the conditions of peridotite-carbonatite interaction in the subcratonic lithosphere ( Experimental data).Doklady Earth Sciences, Vol. 463, 1, pp. 746-750.MantleGarnet, carbonatite

Abstract: The article focuses on the study of composition of garnets of the lherzolitic and harzburgitic parageneses and the conditions of peridotite. As per the study, reconstruction of the conditions of metasomatism of peridotitic sources of kimberlite is possible in the evolution of garnet. It mentions the importance of dry and hydrous carbonatitic melt upon alteration of peridotitic sources of kimberlite as it acted as an another heat source.
DS201510-1805
2015
Sobolev, N.V.Sobolev, N.V., Sobolev, A.V., Tomilenko, A.A., Batanova, V.G., Tolstov, A.V., Logvinova, A.M., Kuzmin, D.V.Unique compositional pecularities of olivine phenocrysts from the post flood basalt Diamondiferous Malokuonapskaya kimberlite pipe, Yakutia.Doklady Earth Sciences, Vol. 463, 2, pp. 828-832.RussiaDeposit - Malokuonapskaya
DS201512-1978
2015
Sobolev, N.V.Taylor, L.A., Logvinova, A.M., Howarth, G.H., Liu, Y., Peslier, A.H., Rossman, G.R., Guan, Y., Chen, Y., Sobolev, N.V.Low water contents in diamond mineral inclusions: proto-genetic origin in a dry cratonic lithosphere.Earth and Planetary Science Letters, Vol. 433, pp. 125-132.MantleNAMs Nominally Anhydrous Minerals

Abstract: The mantle is the major reservoir of Earth's water, hosted within Nominally Anhydrous Minerals (NAMs) (e.g., , , and ), in the form of hydrogen bonded to the silicate's structural oxygen. From whence cometh this water? Is the water in these minerals representative of the Earth's primitive upper mantle or did it come from melting events linked to crustal formation or to more recent metasomatic/re-fertilization events? During diamond formation, NAMs are encapsulated at hundreds of kilometers depth within the mantle, thereby possibly shielding and preserving their pristine water contents from re-equilibrating with fluids and melts percolating through the lithospheric mantle. Here we show that the NAMs included in diamonds from six locales on the Siberian Craton contain measurable and variable H2O concentrations from 2 to 34 parts per million by weight (ppmw) in olivine, 7 to 276 ppmw in clinopyroxene, and 11-17 ppmw in garnets. Our results suggest that if the inclusions were in equilibrium with the diamond-forming fluid, the water fugacity would have been unrealistically low. Instead, we consider the H2O contents of the inclusions, shielded by diamonds, as pristine representatives of the residual mantle prior to encapsulation, and indicative of a protogenetic origin for the inclusions. Hydrogen diffusion in the diamond does not appear to have modified these values significantly. The H2O contents of NAMs in mantle xenoliths may represent some later metasomatic event(s), and are not always representative of most of the continental lithospheric mantle. Results from the present study also support the conclusions of Peslier et al. (2010) and Novella et al. (2015) that the dry nature of the SCLM of a craton may provide stabilization of its thickened continental roots.
DS201601-0047
2015
Sobolev, N.V.Tomilenko, A.A., Kuzmin, D.V., Bulbak, T.A., Timina, T.Yu., Sobolev, N.V.Composition of primary fluid and melt inclusions in regenerated olivines from hypabyssal kimberlites of the Malokuonapskaya pipe ( Yakutia).Doklady Earth Sciences, Vol. 465, 1, pp. 1168-1171.RussiaDeposit - Malokuonapskaya
DS201602-0206
2016
Sobolev, N.V.Grakhanov, S.A., Zinchuk, N.N., Sobolev, N.V.The age of predictable primary diamond sources in the northeastern Siberian platform.Doklady Earth Sciences, Vol. 465, 2, pp. 1297-1301.Russia, SiberiaDeposit - Malokuonapskaya

Abstract: The U-Pb (SHRIMP) age was determined for zircons collected from 26 observation and sampling sites of diamonds and index minerals in the northeastern Siberian Platform. This part of the region hosts 15 low-diamondiferous Paleozoic and Mesozoic kimberlite fields, excluding the near economic Triassic Malokuonapskaya pipe in the Kuranakh field. Four epochs of kimberlite formation (Silurian, Late Devonian to Early Carboniferous, Middle to Late Triassic, and Middle to Late Jurassic) of the Siberian Platform, including its northeastern part, are confirmed as a result of our studies. Most observation points, including economic Quaternary diamond placers, contain Middle to Late Triassic zircons, which confirms the abundant Late Triassic volcanism in this region. The positive correlation of diamonds and major index minerals of kimberlites (mostly, garnets) at some observation sites indicates the possible Triassic age of the predictable diamondiferous kimberlites.
DS201602-0240
2016
Sobolev, N.V.Sokol, A.G., Kruk, A.N., Chebotarev, D.A., Palynaov, Yu.N., Sobolev, N.V.Conditions of carbonation and wehrlitization of lithospheric peridotite upon interaction with carbonatitic melts.Doklady Earth Sciences, Vol. 465, 2, pp. 1262-1267.RussiaDeposit - Udachnaya

Abstract: Study of the mechanism of carbonation and wehrlitization of harzburgite upon metasomatism by carbonatitic melts of various genesis was carried out. Experiments with durations of 60-150 h were performed at 6.3 GPa and 1200°C. The data showed that carbonatite with MgO/CaO > 0.3 percolating into the peridotitic lithosphere may provide crystallization of magnesite in it. The influence of all studied carbonatites results in wehrlitization of peridotite. The compositions of melts formed by interaction with harzburgite (?2 wt % SiO2, Ca# = 36-47) practically do not depend on the composition of the initial carbonatite. Based on the data obtained, we conclude that the formation of magnesite-bearing and magnesite-free metasomatized peridotites may have a significant influence on the CO2 regime in the further generation of kimberlitic magmas of groups I and II.
DS201602-0245
2016
Sobolev, N.V.Taylor, L.A., Logvinova, A.M., Howarth, G.H., Liu, Y., Peslier, A.H., Rossman, G.R., Guan, Y., Chen, Y., Sobolev, N.V.Low water contents in diamond mineral inclusions: proto-genetic origin in a dry cratonic lithosphere.Earth and Planetary Science Letters, Vol. 433, pp. 125-132.Russia, AfricaKaapvaal and Siberian SCLMs

Abstract: The mantle is the major reservoir of Earth's water, hosted within Nominally Anhydrous Minerals (NAMs) (e.g., , , and ), in the form of hydrogen bonded to the silicate's structural oxygen. From whence cometh this water? Is the water in these minerals representative of the Earth's primitive upper mantle or did it come from melting events linked to crustal formation or to more recent metasomatic/re-fertilization events? During diamond formation, NAMs are encapsulated at hundreds of kilometers depth within the mantle, thereby possibly shielding and preserving their pristine water contents from re-equilibrating with fluids and melts percolating through the lithospheric mantle. Here we show that the NAMs included in diamonds from six locales on the Siberian Craton contain measurable and variable H2O concentrations from 2 to 34 parts per million by weight (ppmw) in olivine, 7 to 276 ppmw in clinopyroxene, and 11-17 ppmw in garnets. Our results suggest that if the inclusions were in equilibrium with the diamond-forming fluid, the water fugacity would have been unrealistically low. Instead, we consider the H2O contents of the inclusions, shielded by diamonds, as pristine representatives of the residual mantle prior to encapsulation, and indicative of a protogenetic origin for the inclusions. Hydrogen diffusion in the diamond does not appear to have modified these values significantly. The H2O contents of NAMs in mantle xenoliths may represent some later metasomatic event(s), and are not always representative of most of the continental lithospheric mantle. Results from the present study also support the conclusions of Peslier et al. (2010) and Novella et al. (2015) that the dry nature of the SCLM of a craton may provide stabilization of its thickened continental roots.
DS201605-0887
2016
Sobolev, N.V.Rezvukhin, D.I., Malkovets, V.G., Sharygin, I.S., Kuzmin, D.V., Litasov, K.D., Gibsher, A.A., Pokhilenko, N.P., Sobolev, N.V.Inclusions of Cr- and Cr-Nb-Rutile in pyropes from the Internationalnaya kimberlite pipe, Yakutia.Doklady Earth Sciences, Vol. 466, 2, Feb. pp. 173-176.Russia, YakutiaDeposit - International

Abstract: The results of study of rutile inclusions in pyrope from the Internatsionalnaya kimberlite pipe are presented. Rutile is characterized by unusually high contents of impurities (up to 25 wt %). The presence of Cr2O3 (up to 9.75 wt %) and Nb2O5 (up to 15.57 wt %) are most typical. Rutile inclusions often occur in assemblage with Ti-rich oxides: picroilmenite and crichtonite group minerals. The Cr-pyropes with inclusions of rutile, picroilmenite, and crichtonite group minerals were formed in the lithospheric mantle beneath the Mirnyi field during their joint crystallization from melts enriched in Fe, Ti, and other incompatible elements as a result of metasomatic enrichment of the depleted lithospheric mantle.
DS201605-0888
2016
Sobolev, N.V.Rezvukhin, D.I., Malkovets, V.G., Sharygin, I.S., Kuzmin, D.V., Litasov, K.D., Gibsher, A.A., Pokhilenko, N.P., Sobolev, N.V.Inclusions of crichonite group minerals in pyropes from the Internatsionalnaya kimberlite pipe, Yakutia.Doklady Earth Sciences, Vol. 466, 2, Feb. pp. 206-209.Russia, YakutiaDeposit - International
DS201606-1101
2016
Sobolev, N.V.Kruk, A.N., Sokol, A.G., Chebotarev, D.A., Palyanov, Yu.A., Sobolev, N.V.Composition of a carbonatitic melt in equilibrium with lherzolite at 5.5-6.3 Gpa and 1350C.Doklady Earth Sciences, Vol. 467, 1, pp. 303-307.Carbonatite

Abstract: Generation of ultra-alkaline melts by the interaction of lherzolite with cardonatites of various genesis was simulated at the P-T parameters typical of the base of the subcratonic lithosphere. Experiments with a duration of 150 h were performed at 5.5 and 6.3 GPa and 1350°C. The concentrations of CaO and MgO in melts are buffered by the phases of peridotite, and the concentrations of alkalis and FeO depend on the composition of the starting carbonatite. Melts are characterized by a low (<7 wt %) concentration of SiO2 and Ca# from 0.40 to 0.47. It is demonstrated that only high-Mg groups of carbonatitic inclusions in fibrous diamonds have a composition close to that of carbonatitic melts in equilibrium with lherzolite. Most likely, the formation of kimberlite-like melts relatively enriched in SiO2 requires an additional source of heat from mantle plumes and probably H2O fluid.
DS201608-1445
2016
Sobolev, N.V.Tomilenko, A.A., Bulbak, T.A., Khomenko, M.O., Kuzmin, D.V., Sobolev, N.V.The composition of volatile components in olivines from Yakutian kimberlites of various ages: evidence from gas chromatography - mass spectrometry.Doklady Earth Sciences, Vol. 469, 1, pp. 690-694.RussiaDeposit - Olivinvaya, Malokuonapskaya, Udachnaya-East

Abstract: The composition of volatiles from fluid and melt inclusions in olivine phenocrysts from Yakutian kimberlite pipes of various ages (Olivinovaya, Malokuonapskaya, and Udachnaya-East) were studied for the first time by gas chromatography-mass spectrometry. It was shown that hydrocarbons and their derivatives, as well as nitrogen-, halogen-, and sulfur-bearing compounds, played a significant role in the mineral formation. The proportion of hydrocarbons and their derivatives in the composition of mantle fluids could reach 99%, including up to 4.9% of chlorineand fluorine-bearing compounds.
DS201610-1874
2016
Sobolev, N.V.Jean, M.M., Taylor, L.A., Howarth, G.H., Peslier, A.H., Fedele, L., Bodnar, R.J., Guan, Y., Doucet, L.S., Ionov, D.A., Logvinova, A.M., Golovin, A.V., Sobolev, N.V.Olivine inclusions in Siberian diamonds and mantle xenoliths: contrasting water and trace -element contents.Lithos, in press available 11p.Russia, SiberiaDiamond inclusions
DS201610-1886
2016
Sobolev, N.V.Melkovets, V.G., Rezvukhin, D.I., Belousova, E.A., Griffin, W.L., Sharygin, I.S., Tretiakova, I.G., Pokhilenko, N.P., Sobolev, N.V.Cr-rich rutile: a powerful tool for diamond exploration.Lithos, in press available 8p.Russia, SiberiaDeposit - Internationalnaya

Abstract: Mineralogical studies and U-Pb dating have been carried out on rutile included in peridotitic and eclogitic garnets from the Internatsionalnaya pipe, Mirny field, Siberian craton. We also describe a unique peridotitic paragenesis (rutile + forsterite + enstatite + Cr-diopside + Cr-pyrope) preserved in diamond from the Mir pipe, Mirny field. Compositions of rutile from the heavy mineral concentrates of the Internatsionalnaya pipe and rutile inclusions in crustal almandine-rich garnets from the Mayskaya pipe (Nakyn field), as well as from a range of different lithologies, are presented for comparison. Rutile from cratonic mantle peridotites shows characteristic enrichment in Cr, in contrast to lower-Cr rutile from crustal rocks and off-craton mantle. Rutile with Cr2O3 > 1.7 wt% is commonly derived from cratonic mantle, while rutiles with lower Cr2O3 may be both of cratonic and off-cratonic origin. New analytical developments and availability of standards have made rutile accessible to in situ U-Pb dating by laser ablation ICP-MS. A U-Pb age of 369 ± 10 Ma for 9 rutile grains in 7 garnets from the Internatsionalnaya pipe is consistent with the accepted eruption age of the pipe (360 Ma). The equilibrium temperatures of pyropes with rutile inclusions calculated using Ni-in-Gar thermometer range between ~ 725 and 1030 °C, corresponding to a depth range of ca ~ 100-165 km. At the time of entrainment in the kimberlite, garnets with Cr-rich rutile inclusions resided at temperatures well above the closure temperature for Pb in rutile, and thus U-Pb ages on mantle-derived rutile most likely record the emplacement age of the kimberlites. The synthesis of distinctive rutile compositions and U-Pb dating opens new perspectives for using rutile in diamond exploration in cratonic areas.
DS201610-1909
2016
Sobolev, N.V.Sobolev, N.V., Shatsky, V.S., Zedgenizov, D.A., Ragozin, A.L., Reutsky, V.N.Polycrystalline diamond aggregates from the Mir kimberlite pipe, Yakutia: evidence for mantle metasomatism.Lithos, in press available 10p.RussiaDeposit - Mir

Abstract: Polycrystalline diamond aggregates (boart, framesites, diamondites) have been widely studied but their origin is poorly understood. We report the results of a study in situ of two polished fragments of fine-grained (40-400 ?m size of individual diamond grains) dense polycrystalline diamond aggregates from the Mir pipe containing visible multiple interstitial garnet inclusions. They were analyzed for major and trace elements of inclusions and one of them — for ?13C and N abundance and isotopic composition of host diamonds. These aggregates are classified as variety IX by Orlov (1977). No cavities were observed in these samples. Sixty two irregular garnet grains and one clinopyroxene inclusion were detected and analyzed in sample Mr 832. Garnets are homogeneous within single grains but variable in Mg# [100Mg/(Mg + Fe)] from 60 up to 87 and CaO contents (3.3-5.3 wt.%) among grains with a trend to negative correlation. Low Cr (550-640 ppm) confirms eclogitic (E-type) paragenesis. High Na2O contents (5.2 wt.%) of a single pyroxene inclusion are additional evidence of eclogitic nature of this sample. Wide variations in trace elements (ppm) are characteristic for garnet grains: Sr (2.7-25.6), Y (9.7-14.1), Zr (15.6-38.7) and positive Eu anomaly is present. The ?13C of diamonds within studied sample is variable (? 6.4 ÷? 9.8 ‰) as well as N abundance (75-1150 ppm) and ?15N ? 27, ? 38, ? 58 ‰. The second peridotitic (U/P-type) sample Mr 838 contains eight inclusions of Mg-rich Cr-pyropes (Mg# ~ 85, Cr2O3 3.2-3.4 wt.%) and magnesite inclusion with 4.35 wt.% FeO and 1.73 wt.% CaO. Trace element content in pyropes is relatively uniform (ppm): Sr (0.4-1.6), Y (13.2-13.4) and Zr (13.0). We conclude that heterogeneous distribution of the trace elements among garnet grains in Mr 832 and magnesite presence in Mr 838 are indicative of the effects of mantle metasomatism and rapid crystallization shortly before the eruption of the kimberlite.
DS201610-1910
2016
Sobolev, N.V.Sobolev, N.V., Wirth, R., Logvinova, A.M., Yelisseyev, A.P., Kuzmin, D.V.Retrograde isochemical phase transformations of majoritic garnets included in diamonds: a case study of subcalcic Cr-rich majoritic pyrope from a Snap Lake diamond, Canada.Lithos, in press available 11p.Canada, Northwest TerritoriesDeposit - Snap Lake

Abstract: Homogeneity of a peridotitic garnet inclusion in diamond demonstrating excess in Si concentration (i.e. presence of majorite component) was investigated by TEM using FIB prepared foils. The host diamond is a low-nitrogen brown stone, which can be related to type IIa with features of strong plastic deformation. The studied sample is represented by Ca-poor Cr-pyrope of harzburgitic (H) paragenesis from Snap Lake dyke, Canada The garnet had been previously reported to contain Si = 3.16 apfu. The revised examination of the sample, resulted in detection of extremely fine-grained symplectite consisting of low Ca-orthopyroxene, clinopyroxene, Cr-spinel and coesite completely located and isolated in the inner part of the garnet crystal, which forms a sharp interface with the surrounding homogeneous garnet. XRD study confirmed the presence of the minerals constituting the symplectite. EPMA showed an identical bulk chemistry of the nanometer-sized symplectite and garnet. Further polishing of the garnet inclusion on the same surface with diamond removed the symplectite, which possibly was present as a thin lens within garnet. The remaining garnet is completely homogeneous as checked by two profiles, and contains unusually high Ni (118.2 ppm) and depleted REE patterns. Estimated PT formation conditions of this garnet are 10.8 GPa and 1450 °C within asthenosphere. Symplectite testifies partial retrograde isochemical phase transformation of the examined garnet which is suggested to be caused by decompression along with plastic deformation of diamond within the coesite stability field at T > 1000 °C and depth no less than 100 km. Because previously published studies of rare majoritic garnets composition were performed by EPMA only, it is possible that the traces of partial phase transformation (symplectite formation) could have been overlooked without additional XRD and/or TEM/AEM studies.
DS201612-2320
2016
Sobolev, N.V.Malkovets, V.G., Rezvukhin, D.I., Belousova, E.A., Griffin, W.L., Sharygin, I.S., Tretiakov, I.G., Gibsher, A.A., O'Reilly, S.Y., Kuzmin, D.V., Litasov, K.D., Logvinova, A.M., Pokhilenko, N.P., Sobolev, N.V.Cr-rich rutile: a powerful tool for diamond exploration.Lithos, Vol. 265, pp. 304-311.Russia, SiberiaDeposit - Internationalskaya

Abstract: Mineralogical studies and U-Pb dating have been carried out on rutile included in peridotitic and eclogitic garnets from the Internatsionalnaya pipe, Mirny field, Siberian craton. We also describe a unique peridotitic paragenesis (rutile + forsterite + enstatite + Cr-diopside + Cr-pyrope) preserved in diamond from the Mir pipe, Mirny field. Compositions of rutile from the heavy mineral concentrates of the Internatsionalnaya pipe and rutile inclusions in crustal almandine-rich garnets from the Mayskaya pipe (Nakyn field), as well as from a range of different lithologies, are presented for comparison. Rutile from cratonic mantle peridotites shows characteristic enrichment in Cr, in contrast to lower-Cr rutile from crustal rocks and off-craton mantle. Rutile with Cr2O3 > 1.7 wt% is commonly derived from cratonic mantle, while rutiles with lower Cr2O3 may be both of cratonic and off-cratonic origin. New analytical developments and availability of standards have made rutile accessible to in situ U-Pb dating by laser ablation ICP-MS. A U-Pb age of 369 ± 10 Ma for 9 rutile grains in 6 garnets from the Internatsionalnaya pipe is consistent with the accepted eruption age of the pipe (360 Ma). The equilibrium temperatures of pyropes with rutile inclusions calculated using Ni-in-Gar thermometer range between ~ 725 and 1030 °C, corresponding to a depth range of ca ~ 100-165 km. At the time of entrainment in the kimberlite, garnets with Cr-rich rutile inclusions resided at temperatures well above the closure temperature for Pb in rutile, and thus U-Pb ages on mantle-derived rutile most likely record the emplacement age of the kimberlites. The synthesis of distinctive rutile compositions and U-Pb dating opens new perspectives for using rutile in diamond exploration in cratonic areas.
DS201701-0003
2016
Sobolev, N.V.Bataleva, Yu.V., Palyanov, Yu.N., Borzdov, Yu.M., Sobolev, N.V.Graphite and diamond formation via the interaction of iron carbide and Fe, Ni sulfide under mantle P-T parameters.Doklady Earth Sciences, Vol. 471, 1, pp. 1144-1148.TechnologyPetrology - experimental

Abstract: Experimental research in the Fe3C-(Fe,Ni)S system was carried out. The objective of the investigation was to model the reactions of carbide-sulfide interaction related to graphite (diamond) formation in reduced lithosphere mantle domains. T ? 1200°C is the formation temperature of the Ni-cohenite + graphite assemblage coexisting with two immiscible melts such as sulfide (Fe60-Ni3-S37)L and metal-sulfide (Fe71-Ni7-S21-C1)L containing dissolved carbon. T ? 1300°C is the generation temperature of a unified melt such as (Fe80-Ni6-S10-C4)L characterized by graphite crystallization and diamond growth. The extraction of carbide carbon during the interaction with the sulfide melt can be considered as one of the potential mechanisms of graphite and diamond formation in the reduced mantle.
DS201705-0876
2017
Sobolev, N.V.Sokol, A.G., Kruk, A.N., Palynov, Y.N., Sobolev, N.V.Stability of phlogopite in ultrapotassic kimberlite-like systems at 5.5-7.5 Gpa.Contributions to Mineralogy and Petrology, in press available 22p.MantleMetasomatism, magmatism, carbonatite

Abstract: Hydrous K-rich kimberlite-like systems are studied experimentally at 5.5-7.5 GPa and 1200-1450 °C in terms of phase relations and conditions for formation and stability of phlogopite. The starting samples are phlogopite-carbonatite-phlogopite sandwiches and harzburgite-carbonatite mixtures consisting of Ol + Grt + Cpx + L (±Opx), according to the previous experimental results obtained at the same P-T parameters but in water-free systems. Carbonatite is represented by a K- and Ca-rich composition that may form at the top of a slab. In the presence of carbonatitic melt, phlogopite can partly melt in a peritectic reaction at 5.5 GPa and 1200-1350 °C, as well as at 6.3-7.0 GPa and 1200 °C: 2Phl + CaCO3 (L)?Cpx + Ol + Grt + K2CO3 (L) + 2H2O (L). Synthesis of phlogopite at 5.5 GPa and 1200-1350 °C, with an initial mixture of H2O-bearing harzburgite and carbonatite, demonstrates experimentally that equilibrium in this reaction can be shifted from right to left. Therefore, phlogopite can equilibrate with ultrapotassic carbonate-silicate melts in a ? 150 °C region between 1200 and 1350 °C at 5.5 GPa. On the other hand, it can exist but cannot nucleate spontaneously and crystallize in the presence of such melts in quite a large pressure range in experiments at 6.3-7.0 GPa and 1200 °C. Thus, phlogopite can result from metasomatism of peridotite at the base of continental lithospheric mantle (CLM) by ultrapotassic carbonatite agents at depths shallower than 180-195 km, which creates a mechanism of water retaining in CLM. Kimberlite formation can begin at 5.5 GPa and 1350 °C in a phlogopite-bearing peridotite source generating a hydrous carbonate-silicate melt with 10-15 wt% SiO2, Ca# from 45 to 60, and high K enrichment. Upon further heating to 1450 °C due to the effect of a mantle plume at the CLM base, phlogopite disappears and a kimberlite-like melt forms with SiO2 to 20 wt% and Ca# = 35-40.
DS201709-2022
2017
Sobolev, N.V.Logvinova, A.M., Wirth, R., Sobolev, N.V.Hydrous silicates within black cloudy zone in diamonds.Goldschmidt Conference, abstract 1p.Canada, Northwest Territoriesdeposit - Diavik

Abstract: Is there the existence of a water-rich zone in the mantle, currently one of the most discussed problem in mantle petrology? There are recent studies of low-water content in nominally anhydrous minerals in diamonds [1] and the chemistry of exceptionally rare phlogopite inclusions coexisting with peridotitic and eclogitic minerals in kimberlite-hosted diamonds [2]. Previous studies have shown that some rapidly formed diamonds reflect the composition of the environment in which they formed [3]. The minerals trapped during nucleation stage remain shielded from any changing conditions during further diamond growth or later mantle metasomatism. Thus, the analysis of diamond microinclusions is a major tool for the direct study of mantle high-density fluids (HDFs) from which the diamonds have precipitated [4]. Using transmission electron microscopy (TEM) techniques, we have investigated hydrous silicates inside nanometerscale, polyphased unclusions, especially in dark cloudy alluvial and kimberlite diamonds. Clinohumite, phlogopite, and phengite were detected. Hydrous silicate phases are accompanied by Ba-Sr-Ca -Fe-Mg carbonates, in addition to sulfides, oxides (magnetite, rutile, ilmenite), F-apatite, KCl, graphite, and fluid bubbles. A contrast occurs between clinohumite associated with phlogopite, F-apatite and highMg carbonates, but phengite, accompanied by a Al, Kbearing, unidentified silicate. These inclusions reflect the composition of fluid from which the host diamond crystallized. The mica composition, in most cases, has excess Si, similar to the high-silica mica identified within diamond microinclusions from Diavik [5]. The fluid-bearing carbonatitic-silicic diamonds grew in water-rich environments with extremely high K-activity, compared to most diamonds, which grew only within limited zones in the Earth’s mantle.
DS201709-2064
2017
Sobolev, N.V.Tomilenko, A.A., Dublansky, Yu.V., Kuzmin, D.V., Sobolev, N.V.Isotope compositions of C and O of magmatic calcites from the Udachnaya-East pipe kimberlite, Yakutia.Doklady Earth Sciences, Vol. 475, 1, pp. 828-831.Russia, Yakutiadeposit - Udachnaya-East

Abstract: It has been demonstrated for the first time that the isotopic compositions of carbon (?13C) in magmatic calcites from the Udachnaya–East pipe kimberlite groundmass varies from–2.5 to–1.0‰ (V-PDB), while those of oxygen (?18O) range from 15.0 to 18.2‰ (V-SMOW). The obtained results imply that during the terminal late magmatic and postmagmatic stages of the kimberlite pipe formation, the carbonates in the kimberlite groundmass became successively heavier isotopically, which indicates the hybrid nature of the carbonate component of the kimberlite: it was formed with contributions from mantle and sedimentary marine sources.
DS201710-2266
2017
Sobolev, N.V.Sobolev, N.V., Schertle, H-P., Neuser, R.D., Tomilenko, A.A., Kuzmin, D.V., Loginova, A.M., Tolstov, A.V., Kostrovitsky, S.I., Yakovlev, D.A., Oleinikov, O.B.Formation and evolution of hypabyssal kimberlites from the Siberian craton: part 1 - new insights from cathodluminescence of the carbonates. Anabar and Olenek areaJournal of Asian Earth Sciences, Vol. 145, pt. B, pp. 670-678.Russia, Siberiadeposit - Kuranakh, Kharamay
DS201710-2269
2017
Sobolev, N.V.Tomilenko, A.A., Kuzmin, D.V., Bulbak, T.A., Sobolev, N.V.Primary melt and fluid inclusions in regenerated crystals and phenocrysts of olivine from kimberlites of the Udachnaya-East pipe, Yakutia: the problem of the kimberlite melt.Doklady Earth Sciences, Vol. 475, 2, pp. 949-952.Russiadeposit - Udachnaya-East

Abstract: The primary melt and fluid inclusions in regenerated zonal crystals of olivine and homogeneous phenocrysts of olivine from kimberlites of the Udachnaya-East pipe, were first studied by means of microthermometry, optic and scanning electron microscopy, electron and ion microprobe analysis (SIMS), inductively coupled plasma mass-spectrometry (ICP MSC), and Raman spectroscopy. It was established that olivine crystals were regenerated from silicate-carbonate melts at a temperature of ~1100°C.
DS201712-2728
2017
Sobolev, N.V.Seryotkin, Yu.V., Skvortsova, V.L., Logvinova, A.M., Sobolev, N.V.Results of study of crystallographic orientation of olivine and diamond from Udachnaya kimberlite pipe, Yakutia.Doklady Earth Sciences, Vol. 476, 2, pp. 1155-1158.Russia, Yakutiadeposit - Udachnaya

Abstract: The crystallographic orientation of three diamonds and 19 olivine inclusions from Udachnaya kimberlite pipe was studied using monocrystal X-ray diffractometry. No epitaxial olivine inclusions were found.
DS201804-0673
2018
Sobolev, N.V.Biller, A.Ya., Logvinova, A.M., Babushkina, S.A., Oleynikov, O.B., Sobolev, N.V.Shrilankite inclusions in garnets from kimberlite bodies and Diamondiferous volcanic-sedimentary rocks of the Yakutian kimberlite province, Russia.Doklady Earth Sciences, Vol. 478, 1, pp. 15-19.Russia, Yakutiadeposit - Yubileinaya

Abstract: Pyrope-almandine garnets (Mg# = 28.3-44.9, Ca# = 15.5-21.3) from a heavy mineral concentrate of diamondiferous kimberlites of the largest diamond deposit, the Yubileinaya pipe, along with kimberlite- like rocks and diamondiferous volcano-sediments of the Laptev Sea coast, have been found to contain polymineral, predominantly acicular inclusions, composed of aggregates of shrilankite (Ti2ZrO6), rutile, ilmenite, clinopyroxene, and apatite. The presence of shrilankite as an inclusion in garnets from assumed garnet-pyroxene rocks of the lower crust, lifted up by diamond-bearing kimberlite, allows it to be considered as an indicator mineral of kimberlite, which expands the possibilities when searching for kimberlite in the Arctic.
DS201804-0739
2018
Sobolev, N.V.Sobolev, N.V.Inclusions in Siberian diamonds and their polycrystalline aggregates and specific features of orogenic diamonds from Kazkhstan.4th International Diamond School: Diamonds, Geology, Gemology and Exploration Bressanone Italy Jan. 29-Feb. 2nd., pp. 41-42. abstractRussiadiamond inclusions
DS201806-1212
2018
Sobolev, N.V.Bataleva, Yu.V., Palyanov, Yu.N., Borzdov, Yu.N., Zdrokov, E.V., Novoselov, I.D., Sobolev, N.V.Formation of the Fe, Mg-silicates, FeO, and graphite ( diamond) assemblage as a result of cohenite oxidation under lithospheric mantle conditions.Doklady Earth Sciences, Vol. 479, 1, pp. 335-338.Mantlegraphite

Abstract: Experimental studies in the Fe3C-SiO2-MgO system (P = 6.3 GPa, T = 1100-1500°C, t = 20-40 h) have been carried out. It has been established that carbide-oxide interaction resulted in the formation of Fe-orthopyroxene, graphite, wustite, and cohenite (1100 and 1200°C), as well as a Fe-C-O melt (1300-1500°C). The main processes occurring in the system at 1100 and 1200°C are the oxidation of cohenite, the extraction of carbon from carbide, and the crystallization of metastable graphite, as well as the formation of ferrosilicates. At T ? 1300°C, graphite crystallization and diamond growth occur as a result of the redox interaction of a predominantly metallic melt (Fe-C-O) with oxides and silicates. The carbide-oxide interaction studied can be considered as the basis for modeling a number of carbon-producing processes in the lithospheric mantle at fO2 values near the iron-wustite buffer.
DS201809-2064
2018
Sobolev, N.V.Logvinova, A.M., Babushkina, S.A., Oleynikov, O.B., Sobolev, N.V.Shrilankite inclusions in garnets from kimberlite bodies and Diamondiferous volcanic sedimentary rocks of the Yakutian kimberlite province.Doklady Earth Sciences, Vol. 478, 1, pp. 15-19.Russiadiamond inclusions

Abstract: Pyrope-almandine garnets (Mg# = 28.3-44.9, Ca# = 15.5-21.3) from a heavy mineral concentrate of diamondiferous kimberlites of the largest diamond deposit, the Yubileinaya pipe, along with kimberlite- like rocks and diamondiferous volcano-sediments of the Laptev Sea coast, have been found to contain polymineral, predominantly acicular inclusions, composed of aggregates of shrilankite (Ti2ZrO6), rutile, ilmenite, clinopyroxene, and apatite. The presence of shrilankite as an inclusion in garnets from assumed garnet-pyroxene rocks of the lower crust, lifted up by diamond-bearing kimberlite, allows it to be considered as an indicator mineral of kimberlite, which expands the possibilities when searching for kimberlite in the Arctic.
DS201812-2778
2018
Sobolev, N.V.Bataleva, Yu.V., Palyanov, Yu.N., Borzdov, Yu.M., Novoselov, I.D., Bayukov, O.A., Sobolev, N.V.Conditions of formation of iron-carbon melt inclusions in garnet and orthopyroxene under P-T conditions of lithospheric mantle.Petrology, Vol. 26, 6, pp. 565-574.Mantleredox

Abstract: Of great importance in the problem of redox evolution of mantle rocks is the reconstruction of scenarios of alteration of Fe0- or Fe3C-bearing rocks by oxidizing mantle metasomatic agents and the evaluation of stability of these phases under the influence of fluids and melts of different compositions. Original results of high-temperature high-pressure experiments (P = 6.3 GPa, T = 13001500°?) in the carbideoxidecarbonate systems (Fe3CSiO2(Mg,Ca)CO3 and Fe3CSiO2Al2O3(Mg,Ca)CO3) are reported. Conditions of formation of mantle silicates with metallic or metalcarbon melt inclusions are determined and their stability in the presence of CO2-fluid representing the potential mantle oxidizing metasomatic agent are estimated. It is established that garnet or orthopyroxene and CO2-fluid are formed in the carbideoxidecarbonate system through decarbonation, with subsequent redox interaction between CO2 and iron carbide. This results in the formation of assemblage of Fe-rich silicates and graphite. Garnet and orthopyroxene contain inclusions of a FeC melt, as well as graphite, fayalite, and ferrosilite. It is experimentally demonstrated that the presence of CO2-fluid in interstices does not affect on the preservation of metallic inclusions, as well as graphite inclusions in silicates. Selective capture of FeC melt inclusions by mantle silicates is one of the potential scenarios for the conservation of metallic iron in mantle domains altered by mantle oxidizing metasomatic agents.
DS201812-2819
2018
Sobolev, N.V.Hwang, S.L., Shen, P., Yui, T.F., Chu, H.T., Logvinova, A.M., Sobolev, N.V.Low energy phase boundary pairs and preferred crystallographic orientations of olivines in nanometer-sized ultrapotassic fluid inclusions of Aykhal diamond.Lithos, Vol. 322, pp. 392-404.Russiadeposit - Aykhal

Abstract: The healed internal conjugated cleavages at the core of Aykhal octahedral diamond sample AH2 were decorated with {111}dia-facetted ultrapotassic fluid/melt inclusion pockets containing nanosized graphite, phlogopite and olivine (Fo92) inclusions. These olivines are either rounded in pockets with ample fluid, or facetted by the {111}dia mold in the pockets with a fluid film. Transmission electron microscopy revealed two distinct crystallographic characteristics of olivine inclusions: (1) pronounced crystallographic texture of olivines grouped in specific diamond domain, and (2) frequent parallelism or sub-parallelism of specific low-energy faces of the two phases, mainly (010)ol, {120}ol, (001)ol and {111}dia, {110}dia, {100}dia in the order of decreasing preference, forming prominent (010)ol/{111}dia, (010)ol/{110}dia, (001)ol/{110}dia, {120}ol/{111}dia, and {120}ol/{110}dia low-energy phase boundaries with thin liquid film of 1-2?nm in between. These findings not only testify to the extremely low adhesion energies of olivine-diamond boundary pairs, but also imply that, in the presence of a fluid phase, the interfacial energetics and the energetically favored crystallographic orientations of olivine inclusions in diamond can be controlled simply by the settlement/attachment of low-energy facets of olivine crystals precipitating from the parental fluid upon the low-energy {111}dia or {110}dia surfaces of diamond. Such interfacial energetics control and the resultant low-energy boundary pairs are characteristically distinct from the common topotaxy or epitaxy between oxide/silicate mineral pairs, but are in a sense like the Van der Waals heteroepitaxy in artificial systems.
DS201901-0006
2018
Sobolev, N.V.Bataleva, Yu.V., Palyanov, Yu.N., Borzdov, Yu.M., Bayukov, O.A., Sobolev, N.V.Experiment al modeling of Co forming processes involving cohenite and CO2 fluid in a silicate mantle.Doklady earth Sciences, Vol. 483, 1, pp. 1427-1430.Mantlepetrology

Abstract: Experimental studies were performed in the Fe3C-SiO2-(Mg,Ca)CO3 system (6.3 GP?, 1100-1500°C, 20-40 h). It is established that the carbide-oxide-carbonate interaction leads to the formation of ferrosilite, fayalite, graphite, and cohenite (1100 and 1200°?), as well as a Fe-C melt (1300°?). It is determined that the main processes in the system are decarbonation, redox-reactions of cohenite and a CO2-fluid, extraction of carbon from carbide, and crystallization of metastable graphite (± diamond growth), as well as the formation of ferriferous silicates. The interaction studied can be considered as a simplified model of the processes that occur during the subduction of oxidized crustal material to reduced mantle rocks.
DS201901-0007
2018
Sobolev, N.V.Bataleva, Yu.V., Palyanov, Yu.N., Borzdov, Yu.M., Novoselov, I.D., Bayukov, O.A., Sobolev, N.V.Conditions of formation of iron-carbon melt inclusions in garnet and orthopyroxene under P-T conditions of lithospheric mantle.Petrology, Vol. 26, 6, pp. 565-574.Mantlemetasomatism

Abstract: Of great importance in the problem of redox evolution of mantle rocks is the reconstruction of scenarios of alteration of Fe?- or Fe3C-bearing rocks by oxidizing mantle metasomatic agents and the evaluation of stability of these phases under the influence of fluids and melts of different compositions. Original results of high-temperature high-pressure experiments (P = 6.3 GPa, T = 1300-1500°?) in the carbide-oxide-carbonate systems (Fe3C-SiO2-(Mg,Ca)CO3 and Fe3C-SiO2-Al2O3-(Mg,Ca)CO3) are reported. Conditions of formation of mantle silicates with metallic or metal-carbon melt inclusions are determined and their stability in the presence of CO2-fluid representing the potential mantle oxidizing metasomatic agent are estimated. It is established that garnet or orthopyroxene and CO2-fluid are formed in the carbide-oxide-carbonate system through decarbonation, with subsequent redox interaction between CO2 and iron carbide. This results in the formation of assemblage of Fe-rich silicates and graphite. Garnet and orthopyroxene contain inclusions of a Fe-C melt, as well as graphite, fayalite, and ferrosilite. It is experimentally demonstrated that the presence of CO2-fluid in interstices does not affect on the preservation of metallic inclusions, as well as graphite inclusions in silicates. Selective capture of Fe-C melt inclusions by mantle silicates is one of the potential scenarios for the conservation of metallic iron in mantle domains altered by mantle oxidizing metasomatic agents.
DS201901-0096
2018
Sobolev, N.V.Zhimulev, E.I., Chepurov, A.I., Sobolev, N.V.Genesis of diamond in metal-carbon and metal-sulfur carbon melts: evidence from experimental data. ( light yellow and colorless diamond)Doklady earth Sciences, Vol. 483, 1, pp. 1473-1474.Mantlemelting

Abstract: The experimental data on diamond growth in the Fe-Ni-S-C and Fe-S-C systems with a sulfur content of 5-14 wt % at 5.5 GPa and 1300-1350°C are reported. Colorless and light yellow diamond crystals with a weight of 0.1-0.8 ct were synthesized. It is shown in the Fe-S-C system that at 5.5. GPa diamond may crystallize in a very narrow temperature range, from 1300 to 1370°C. Based on comparative analysis of the experimental data and the results of the study of native iron inclusions in natural diamonds from kimberlite pipes, it is suggested that diamond genesis may be partly controlled by the pre-eutectic (by the concentration of sulfur in relation to metal) metal-sulfide melt.
DS201907-1559
2019
Sobolev, N.V.Logvinova, A.M., Shatskiy, A., Wirth, R., Tomilenko, A.A., Ugapeva, S.S., Sobolev, N.V.Carbonatite melt in type Ia gem diamond.Lithos, in press available, 17p.Russiadeposit - Sytykanskaya

Abstract: Monocrystalline type Ia diamonds with octahedral growth morphology prevail among lithospheric diamonds, including precious stones. Unlike less common ‘fibrous’ diamonds that grew from alkali-rich carbonate-bearing melts and fluids, the growth medium of ‘monocrystalline’ type Ia diamonds remains debatable. Here we report the first finding of an optically visible (~30??m in size) carbonate inclusion in the center of a gem type Ia octahedral diamond from the Sytykanskaya kimberlite pipe, Yakutia. We found that the inclusion consists of submicron size carbonate phases represented by K2Ca(CO3)2 bütschliite (~15?vol%), Na2Mg(CO3)2 eitelite (~5?vol%), and dolomite (~80?vol%). Although neither bütschliite nor eitelite can coexist with dolomite under mantle P-T conditions, these phases readily appear all together in the quenched products of carbonatite melt under mantle pressures. Thus, at the moment of capture, the inclusion material was a carbonatite melt with the following composition 10(K0.75Na0.25)2CO3?90(Ca0.57Mg0.43)CO3. The content of alkali carbonates at the level of 10?mol% indicates that the melt was formed at a temperature of ?1300?°C. The high K/Na and Ca/(Ca?+?Mg) ratios in this melt indicate its derivation by partial melting of recycled marine sediments (pelites). Considering an age of the last subduction event beneath the Siberian craton, our new finding implies that subducting slabs drag carbonated material of the continental crust beneath ancient cratons, where it experiences partial melting to form a potassic dolomitic melt responsible for the formation of most diamonds, since the Late Archean.
DS201908-1797
2019
Sobolev, N.V.Murri, M., Smith, R.L., McColl, K., Hart, M., Alvaro, M., Jones, A.P., Nemeth, P., Salzmann, C.G., Cora, F., Domeneghetti, M.C., Nestola, F., Sobolev, N.V., Vishnevsky, S.A., Logvinova, A.M., McMillan, P.F.Quantifying hexagonal stacking in diamond. ( lonsdaleite)Nature Scientific Reports, doi.org/10.1038/ s41598-019-46556-3 8p. PdfGlobaldiamond morphology, impact craters

Abstract: Diamond is a material of immense technological importance and an ancient signifier for wealth and societal status. In geology, diamond forms as part of the deep carbon cycle and typically displays a highly ordered cubic crystal structure. Impact diamonds, however, often exhibit structural disorder in the form of complex combinations of cubic and hexagonal stacking motifs. The structural characterization of such diamonds remains a challenge. Here, impact diamonds from the Popigai crater were characterized with a range of techniques. Using the MCDIFFaX approach for analysing X-ray diffraction data, hexagonality indices up to 40% were found. The effects of increasing amounts of hexagonal stacking on the Raman spectra of diamond were investigated computationally and found to be in excellent agreement with trends in the experimental spectra. Electron microscopy revealed nanoscale twinning within the cubic diamond structure. Our analyses lead us to propose a systematic protocol for assigning specific hexagonality attributes to the mineral designated as lonsdaleite among natural and synthetic samples.
DS201909-2060
2019
Sobolev, N.V.Logvinova, A.M., Shatskiy, A., Wirth, R., Tomilenko, A.A., Ugapeva, S.S., Sobolev, N.V.Carbonatite melt in type Ia gem diamond. Lithos, Vol. 342-343, pp. 463-467.Russiadeposit - Sytykanskaya

Abstract: Monocrystalline type Ia diamonds with octahedral growth morphology prevail among lithospheric diamonds, including precious stones. Unlike less common ‘fibrous’ diamonds that grew from alkali-rich carbonate-bearing melts and fluids, the growth medium of ‘monocrystalline’ type Ia diamonds remains debatable. Here we report the first finding of an optically visible (~30??m in size) carbonate inclusion in the center of a gem type Ia octahedral diamond from the Sytykanskaya kimberlite pipe, Yakutia. We found that the inclusion consists of submicron size carbonate phases represented by K2Ca(CO3)2 bütschliite (~15?vol%), Na2Mg(CO3)2 eitelite (~5?vol%), and dolomite (~80?vol%). Although neither bütschliite nor eitelite can coexist with dolomite under mantle P-T conditions, these phases readily appear all together in the quenched products of carbonatite melt under mantle pressures. Thus, at the moment of capture, the inclusion material was a carbonatite melt with the following composition 10(K0.75Na0.25)2CO3?90(Ca0.57Mg0.43)CO3. The content of alkali carbonates at the level of 10?mol% indicates that the melt was formed at a temperature of ?1300?°C. The high K/Na and Ca/(Ca?+?Mg) ratios in this melt indicate its derivation by partial melting of recycled marine sediments (pelites). Considering an age of the last subduction event beneath the Siberian craton, our new finding implies that subducting slabs drag carbonated material of the continental crust beneath ancient cratons, where it experiences partial melting to form a potassic dolomitic melt responsible for the formation of most diamonds, since the Late Archean.
DS201910-2287
2019
Sobolev, N.V.Mikhailenko, D.S., Korsakov, A.V., Rezvukhina, O.V., Golovin, A.V., Sobolev, N.V.A find of coesite in diamond bearing kyanite eclogite from the Udachnaya kimberlite pipe, Siberian craton.Doklady Earth Sciences, Vol. 487, 2, pp. 925-928.Russia, Siberiadeposit - Udachnaya

Abstract: A find of coesite in a kyanite graphite-diamond-bearing eclogite xenolith from the Udachnaya-Vostochnaya kimberlite pipe is described in this paper. The coesite relics were found in intensely fractured garnet indicating some influence of the kimberlite melt, which is supported by the typical secondary mineral assemblage around this inclusion. These data indicate that shallower diamond-free coesite-grade rocks (2.7 GPa) underwent metamorphism distinct from diamond-bearing coesite eclogites (?4 GPa). The metasomatic alteration of rock as a result of the C-O-H fluid-rock interaction during diamond crystallization may be another possible reason for the absence of coesite in diamond-bearing xenoliths.
DS201910-2288
2019
Sobolev, N.V.Nestola, F., Zaffiro, G., Mazzucchelli, M.L., Nimis, P., Andreozzi, G.B., Periotto, B., Princivalle, F., Lenaz, D., Secco, L., Pasqualetto, L., Logvinova, A.M., Sobolev, N.V., Lorenzetti, A., Harris, J.W.Diamond inclusion system recording old deep lithosphere conditions at Udachnaya ( Siberia).Nature Research, Vol. 9, 12586 8p. PdfRussia, Siberiadeposit - Udachnaya

Abstract: Diamonds and their inclusions are unique fragments of deep Earth, which provide rare samples from inaccessible portions of our planet. Inclusion-free diamonds cannot provide information on depth of formation, which could be crucial to understand how the carbon cycle operated in the past. Inclusions in diamonds, which remain uncorrupted over geological times, may instead provide direct records of deep Earth’s evolution. Here, we applied elastic geothermobarometry to a diamond-magnesiochromite (mchr) host-inclusion pair from the Udachnaya kimberlite (Siberia, Russia), one of the most important sources of natural diamonds. By combining X-ray diffraction and Fourier-transform infrared spectroscopy data with a new elastic model, we obtained entrapment conditions, Ptrap?=?6.5(2) GPa and Ttrap?=?1125(32)-1140(33) °C, for the mchr inclusion. These conditions fall on a ca. 35?mW/m2 geotherm and are colder than the great majority of mantle xenoliths from similar depth in the same kimberlite. Our results indicate that cold cratonic conditions persisted for billions of years to at least 200?km in the local lithosphere. The composition of the mchr also indicates that at this depth the lithosphere was, at least locally, ultra-depleted at the time of diamond formation, as opposed to the melt-metasomatized, enriched composition of most xenoliths.
DS201911-2559
2019
Sobolev, N.V.Schmitt, A.K., Zack, T., Kooijman, E., Logvinova, A.M., Sobolev, N.V.U-Pb ages of rare rutile inclusions in diamond indicate entrapment synchronous with kimberlite formation. MirLithos, in press available, 47p. PdfRussiadeposit - Mir
DS202008-1379
2020
Sobolev, N.V.Chepurov, A.I., Tomilenko, A.A., Sonin, V.M., Zhimulev, E.I., Bulbak, T.A., Cheperov, A.A., Sobolev, N.V.Interaction of an Fe-Ni melt with anthracene ( C14H10) in the presence of olivine at 3 Gpa: fluid phase composition.Doklady Earth Sciences, Vol. 492, pp. 333-337.MantleUHP, diamond

Abstract: The first results on the interaction between an Fe-Ni melt and anthracene (?14?10) in the presence of olivine at 3 GPa and 1500°? and on the study of the component composition of the fluid generated in this process are presented. The stability of aliphatic hydrocarbons in the implemented conditions is confirmed experimentally. It is established that, under these conditions, crystallization of high-magnesian olivines occurs (Fo = 97-98 mol %). The composition of the fluid is similar to the composition of the fluid from inclusions in synthetic diamonds. The conditions implemented in the experiment might have occurred at the early stages of the Earth’s evolution.
DS202011-2029
2001
Sobolev, N.V.Ashchepkov, I.V., Afanasiev, V.P., Pokhilenko, N.P., Sobolev, N.V., Vladykin, N.V., Saprykin, A.I., Khmelnikova, O.S., Anoshin, G.N.Small note on the composition of Brazilian mantle. *** NOTE DATERevista Brasileira de Geociencas*** ENG, Vol. 31, 4, pp. 653-660. pdfSouth America, Brazilkimberlites

Abstract: Garne ts from couc eru ratc from the vargcm l kimberl ite pipe show a long compos itional range and reveallong lincar tre nds within the lherzolite field in a Cr~Ol - CaO% dia gram (Sobolcv et til. 1974) (lip (0 11% MgO). fon ned by grains of different dimensions with fcw deviations to harzburg itcs . Larger grains (fraction +3) arc higher in CaO with less Cr~01 (to 5.5%). TIle Cr20 1 freq uen cy reduc es in hyperbo lic function for each fraction . IImenites reve;1142-56% Ti0 2l..'Olllpositionai range with linear FeO - MgO correhuions but 3(4) separate groups for A I ~01 suggest different proport ion of co-prccipimted gimlet , probably due to polybn ric Irncnonanon. lncreasing Cr~O l nnd r"t..-Q% conte nt (fractionation uegn:e ) with red ucing TiO~ is in accord with Ar c mod el.. Ganict xenolith fnnnldnin II pipe with large Ga r- Cpxgrains and fine Mica-Curb bearing mat rix refer to 60 kbcr and 35 mv/m2 gcothcrm . 11displays enr iched trace c lement pat ter ns but not completely equilibrated compositions for Ga r anti Cpx. sugges ting low degree me lting of rela tively fertile mantle. St udied uuuc rinlmay s uggcsrmcrasomu tized, relat ively fertile and irre gularly heated mantle bene ath Sombcrn Bra zil as found by (Carvalho & Lccnnrdos 1997).
DS202011-2054
2020
Sobolev, N.V.Murri, M., Smith, R.L., McColl, K., Hart, M., Alvaro, M., Jones, A.P., Nemeth, P., Salzmann, C.G., Cora, F., Domeneghetti, M.C., Nestola, F., Sobolev, N.V., Vishnevsky, S.A., Logvinova, A.M., McMillan, P.F.Quantifying hexagonal stacking in diamond.Nature/scientific reports, 8p. PdfGlobalcrystallography

Abstract: Diamond is a material of immense technological importance and an ancient signifier for wealth and societal status. In geology, diamond forms as part of the deep carbon cycle and typically displays a highly ordered cubic crystal structure. Impact diamonds, however, often exhibit structural disorder in the form of complex combinations of cubic and hexagonal stacking motifs. The structural characterization of such diamonds remains a challenge. Here, impact diamonds from the Popigai crater were characterized with a range of techniques. Using the MCDIFFaX approach for analysing X-ray diffraction data, hexagonality indices up to 40% were found. The effects of increasing amounts of hexagonal stacking on the Raman spectra of diamond were investigated computationally and found to be in excellent agreement with trends in the experimental spectra. Electron microscopy revealed nanoscale twinning within the cubic diamond structure. Our analyses lead us to propose a systematic protocol for assigning specific hexagonality attributes to the mineral designated as lonsdaleite among natural and synthetic samples.
DS202102-0213
2021
Sobolev, N.V.Palyanov, Y.N., Borzdov, Y.M., Sokol, A.G., Btaaleva, Y.V., Kupriyanov, I.N., Reitsky, V.N., Wiedenbeck, M., Sobolev, N.V.Diamond formation in an electric field under deep Earth conditions.Science Advances, Vol. 7, 4, eabb4644 doi: 10.1126/ sciadv.abb4644 28p. PdfMantlegeophysics

Abstract: Most natural diamonds are formed in Earth’s lithospheric mantle; however, the exact mechanisms behind their genesis remain debated. Given the occurrence of electrochemical processes in Earth’s mantle and the high electrical conductivity of mantle melts and fluids, we have developed a model whereby localized electric fields play a central role in diamond formation. Here, we experimentally demonstrate a diamond crystallization mechanism that operates under lithospheric mantle pressure-temperature conditions (6.3 and 7.5 gigapascals; 1300° to 1600°C) through the action of an electric potential applied across carbonate or carbonate-silicate melts. In this process, the carbonate-rich melt acts as both the carbon source and the crystallization medium for diamond, which forms in assemblage with mantle minerals near the cathode. Our results clearly demonstrate that electric fields should be considered a key additional factor influencing diamond crystallization, mantle mineral-forming processes, carbon isotope fractionation, and the global carbon cycle.
DS202104-0591
2021
Sobolev, N.V.Malkovets, V.G., Shatsky, V.S., Dak, A.I., Gibsher, A.A., Yakovlev, I.V., Belousova, E.A., Tsujimori, T., Sobolev, N.V.Evidence for multistage and polychronous alkaline-ultrabasic Mesozoic magmatism in the area of diamondiferous placers of the Ebelyakh River basin, ( eastern slope of the Anabar shield).Doklady Earth Sciences, Vol. 496, 1, pp. 48-52.Russiadeposit - Anabar

Abstract: New mineralogical and isotope-geochemical data for zircon megacrysts (n = 48) from alluvium of Kholomolokh Creek (a tributary of the Ebelakh River) are reported. Using the geochemical classification schemes, the presence of zircons of kimberlitic and carbonatitic genesis was shown. The U-Pb dating of zircons revealed two major age populations: the Triassic (258-221 Ma, n = 18) and Jurassic (192-154 Ma, n = 30). Weighted mean 206Pb/238U ages allowed us to distinguish the following age stages: 155 ± 3, 161 ± 2, 177 ± 1.5, 183 ± 1.5, 190 ± 2, 233 ± 2.5, and 252 ± 4 Ma. It is suggested that the Ebelyakh diamonds could have been transported from the mantle depths by kimberlite, as well as by other related rocks, such as carbonatite, lamprophyre, lamproite, olivine melilitite, etc. Diamonds from the Ebelyakh placers most likely have polygenic native sources and may be associated with polychronous and multistage Middle Paleozoic and Mesozoic kimberlite and alkaline-ultrabasic magmatism in the eastern slope of the Anabar Shield (the Ebelyakh, Mayat, and Billyakh river basins).
DS202104-0594
2021
Sobolev, N.V.Mikhailenko, D.S., Korsakov, A.V., Ohfuji, H., Sobolev, N.V.Silicate inclusions in metamorphic diamonds from the ultra-high pressure Kokchetav complex, Kazakhstan.Doklady Earth Sciences, Vol. 496, pp. 142-145.Russia, Kazakhstandeposit - Kokchetav

Abstract: Mineral inclusions in cubic diamonds from garnet-clinopyroxene rock of the Kokchetav massif were studied. The coexistence of fluid and silicate inclusions in the central part of the diamond of the G0 sample was revealed by means of transmission electron microscopy. Silicate inclusions are represented by intergrowths of garnet and mica, which are spatially related with the carbonate and fluid inclusions. The first finding of silicate inclusions in the cubic diamonds from the UHP complex discovered over 50 years of their study is apparently due to a selective capture of the silicate minerals in the process of the diamond crystallization from the carbonate-bearing C-O-H fluid. The processes of diamond crystallization in the metamorphic deeply subducted rocks and upper mantle rocks, which are carried to the surface as xenoliths by kimberlite melts, have much in common.
DS202110-1634
2021
Sobolev, N.V.Proskumin, V.F., Grakhanov, S.A., Petrov, O.V., Vasiliev, E.A., Berzon, E.I., Antonov, A.V., Sobolev, N.V.Forecast of the diamond potential of Taimyr.Doklady Earth Sciences, Vol. 499, 2, pp. 611-615.Russiadeposit - Taimyr

Abstract: Although irrefutable evidence for the presence of signs of diamondiferous kimberlite on the Taimyr Peninsula were obtained in the 1930s, it was only in 2020 that a macrodiamond (>1 mm) was first discovered in Eastern Taimyr. This was a colorless laminar crystal of a transitional shape from an octahedron to a rhombododecahedron. According to the set of features, the crystal is rare and atypical of the known primary and alluvial deposits of the Siberian Diamond Province. The find of this diamond indicates the presence of primary sources and the need for medium-scale geological survey and exploration over a large area from Anabar Bay (Pronchishchev Ridge) to the west to the Kiryaka-Tas and Tulai-Kiryaka highlands and to the northeast to Tsvetkov Cape.
DS202203-0355
2022
Sobolev, N.V.Loginova, A.M., Serebryannikov, A.O., Sobolev, N.V.Compositional variations and rare paregeneses of multiple magnesiochromite inclusions in Yakutian diamonds.Doklady Earth Sciences, Vol. 501, pt. 1, pp. 919-924. pdfRussia, Yakutiacathodluminescence

Abstract: The zoning of diamonds was studied using cathodoluminescence (CL) and the chemical composition of mineral inclusions in six typical diamonds from kimberlites of Yakutia. The diamonds were ground on special equipment until inclusions with dimensions of 10-200 ?m were brought to the surface. The inclusions are characterized by a morphology reflecting the influence of the host diamonds. Multiple inclusions and intergrowths of magnesiochromite, olivine, pyrope, and phlogopite are located in both the central and peripheral zones of diamonds. In three diamonds, significant differences in the composition of magnesiochromites in different growth zones were observed, while in the other three such differences were not found. The overwhelming majority (five out of the six diamonds studied), according to the compositional features of magnesiochromite, olivine, and phlogopite, belong to the dunite-harzburgite paragenesis prevailing in diamonds from various diamond-bearing provinces of the Earth. In one of the diamonds, a lherzolite paragenesis, identified by the composition of the pyrope inclusion in magnesiochromite, was observed for the first time. The complex history of diamond growth and the variations in the chemical composition of the included minerals indicate the possibility of coexistence of syngenetic and protogenetic inclusions in the same diamond crystal.
DS1997-1075
1997
Sobolev, P.O.Sobolev, P.O., Rundquist, D.V.Change of seismicity in accordance with the stage of tectonic evolution Of the East African Rifts.Doklady Academy of Sciences, Vol. 355, No. 5, Jun-July pp. 664-68.Tanzania, KenyaTectonics, Rifting - gravity
DS202108-1270
2021
Sobolev, S.Baes, M., Sobolev, S., Gerya, T., Stern, R., Brune, S.Plate motion and plume-induced subduction inititation.Gondwana Research, Vol. 98, pp. 277-288. pdfSouth Americasubduction

Abstract: Impingement of a hot buoyant mantle plume head on the lithosphere is one of the few scenarios that can initiate a new subduction zone without requiring any pre-existing weak zones. This mechanism can start subduction and plate tectonics on a stagnant lid and can also operate during active plate tectonics where plume-lithosphere interactions is likely to be affected by plate motion. In this study, we explore the influence of plate motion on lithospheric response to plume head-lithosphere interaction including the effect of magmatic weakening of lithosphere. Using 3d thermo-mechanical models we show that the arrival of a new plume beneath the lithosphere can either (1) break the lithosphere and initiate subduction, (2) penetrate the lithosphere without subduction initiation, or (3) spread asymmetrically below the lithosphere. Outcomes indicate that lithospheric strength and plume buoyancy control plume penetration through the lithosphere whereas the plate speed has a subordinate influence on this process. However, plate motion may affect the geometry and dynamics of plume-lithosphere interaction by promoting asymmetry in the subduction zone shape. When a sufficiently buoyant plume hits a young but subductable moving lithosphere, a single-slab modern-style subduction zone can form instead of multiple subduction zones predicted by stagnant lid models. In the case of subduction initiation of older moving oceanic lithosphere, asymmetrical cylindrical subduction is promoted instead of more symmetrical stagnant lid subduction. We propose that the eastward motion of the Farallon plate in Late Cretaceous time could have played a key role in forming one-sided subduction along the southern and western margin of the Caribbean and NW South America.
DS1983-0110
1983
Sobolev, S.V.Artyushkov, E.V., Sobolev, S.V.Physics of Kimberlite Magmatism: AppendixAnnales Scientifiques De L' Universite De Clermont-ferrand Ii, No. 74, PP. 137-140.RussiaTechnical Caluculations
DS1984-0117
1984
Sobolev, S.V.Artyushkov, E.V., Sobolev, S.V.Physics of Kimberlite MagmatismProceedings of Third International Kimberlite Conference, Vol. 1, PP. 308-321.GlobalGenesis, Model, Diapir-crack
DS1987-0697
1987
Sobolev, S.V.Sobolev, S.V.Conditions of transport of plutonic xenolithsDoklady Academy of Science USSR, Earth Science Section, Vol. 297, No. 6, Nov-Dec., pp. 23-26RussiaXenoliths, Magma transport
DS1995-1795
1995
Sobolev, S.V.Sobolev, S.V., Widmer, R., Babeyko, A.Yu.3-D temperature and composition in the upper mantle constraint by global seismic tomography/mineral physicsProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 561-563.MantleTomography, Geophysics -seismics
DS1996-1341
1996
Sobolev, S.V.Sobolev, S.V., Fuchs, K.Meeting of geophysics with kimberlites - preface editorialTectonophysics, Vol. 262, No. 1-4, Sept. 30, p.1.RussiaGeophysics
DS1996-1342
1996
Sobolev, S.V.Sobolev, S.V., Zeyen, H., et al.Upper mantle temperatures from teleseismic tomography of French massif central - composition, reactions, meltEarth and Planetary Science Letters, Vol. 140, pp. 147-163GlobalMantle tomography, Geophysics -seismics
DS2002-0850
2002
Sobolev, S.V.Kind, R., Yuan, X., Saul, J., Nelson, D., Sobolev, S.V., Mechie, J., Zhao, W.Seismic images of crust and upper mantle beneath Tibet: evidence for Eurasian plateScience, No. 5596, pp. 1219-1221.Mantle, ChinaGeophysics - seismics
DS2002-1617
2002
Sobolev, S.V.Trumbull, R.B., Sobolev, S.V., Bauer, K.Petrophysical modeling of high seismic velocity crust at the Namibian volcanic marginGeological Society of America Special Paper, No. 362, pp. 221-34.NamibiaGeophysics - seismics
DS2003-0085
2003
Sobolev, S.V.Bauer, K., Schukze, A., Ryberg, T., Sobolev, S.V., Weber, M.H.Classification of lithology from seismic tomography: a case study from the MessumJournal of Geophysical Research, Vol. 108, B3, 10.1029/2001JB001073.NamibiaGeophysics - seismics, Not specific to diamonds
DS2003-0812
2003
Sobolev, S.V.Li, X., Kind, R., Yuan, X., Sobolev, S.V., Hanka, W., Ramesh, D.S., Gu, Y.Seismic observation of narrow plumes in the oceanic upper mantleGeophysical Research Letters, Vol. 30, 6, p. 67. DOI10.1029/2002GLO15411MantlePlumes
DS2003-1394
2003
Sobolev, S.V.Trumbull, R.B., Sobolev, S.V., Bauer, K.Petrophysical modeling of high seismic velocity crust at the Namibian volcanic marginGeological Society of America Special Paper, No. 362, chapter 12.NamibiaMagmatism, Petrology
DS200412-1130
2003
Sobolev, S.V.Li, X., Kind, R., Yuan, X., Sobolev, S.V., Hanka, W., Ramesh, D.S., Gu, Y., Dziewonski, A.M.Seismic observation of narrow plumes in the oceanic upper mantle.Geophysical Research Letters, Vol. 30, 6, p. 67. DOI10.1029/2002 GLO15411MantleGeophysics - seismics Plumes
DS200412-2016
2002
Sobolev, S.V.Trumbull, R.B., Sobolev, S.V., Bauer, K.Petrophysical modeling of high seismic velocity crust at the Namibian volcanic margin.Geological Society of America Special Paper, No. 362, pp. 221-34.Africa, NamibiaGeophysics - seismics
DS200512-0235
2005
Sobolev, S.V.Dobolev, A.V., Hofmann, A.W., Sobolev, S.V., Nikogosian, I.K.An olivine free mantle source of Hawaiian shield basalts.Nature, No. 7033, March 31, pp. 590-597.Mantle, HawaiiGeochemistry
DS201012-0733
2009
Sobolev, S.V.Sobolev, A.V., Sobolev, S.V., Kuzmin, D.V., Malitch, K.N., Petrunin, A.G.Siberian meimechites: origin and relation to flood basalts and kimberlites.Russian Geology and Geophysics, Vol. 50, 12, pp. 999-1033.Russia, SiberiaMeimechite
DS201506-0261
2015
Sobolev, S.V.Dannberg, J., Sobolev, S.V.Low-bouyancy thermochemical plumes resolve controversy of classical mantle plume concept.Nature Communications, Vol. 6, 6960 DOI: 10.1038 /ncomms7960MantleMagmatism
DS201802-0220
2017
Sobolev, S.V.Baes, M., Sobolev, S.V.Mantle flow as a trigger for subduction initiation: a missing element of the Wilson Cycle concept.Geochemistry, Geophysics, Geosystems, Vol. 18, 12, pp. 4469-4486.Mantlesubduction

Abstract: The classical Wilson Cycle concept, describing repeated opening and closing of ocean basins, hypothesizes spontaneous conversion of passive continental margins into subduction zones. This process, however, is impeded by the high strength of passive margins, and it has never occurred in Cenozoic times. Here using thermomechanical models, we show that additional forcing, provided by mantle flow, which is induced by neighboring subduction zones and midmantle slab remnants, can convert a passive margin into a subduction zone. Models suggest that this is a long-term process, thus explaining the lack of Cenozoic examples. We speculate that new subduction zones may form in the next few tens of millions of years along the Argentine passive margin and the U.S. East Coast. Mantle suction force can similarly trigger subduction initiation along large oceanic fracture zones. We propose that new subduction zones will preferentially originate where subduction zones were active in the past, thus explaining the remarkable colocation of subduction zones during at least the last 400 Myr.
DS201806-1237
2018
Sobolev, S.V.Osei Tutu, A., Sobolev, S.V., Steinberger, B., Popov, A.A., Rogozhina, I.Evaluating the influence of plate boundary friction and mantle viscosity on plate velocities.Geochemistry, Geophysics, Geosystems, Vol. 19, 3, pp. 642-666.Mantlegeophysics - seismic
DS201907-1577
2019
Sobolev, S.V.Sobolev, S.V., Brown, M.Surface erosion events controlled the evolution of plate tectonics on Earth.Nature, Vol. 570, June 6, p. 52-57.Mantleplate tectonics

Abstract: Plate tectonics is among the most important geological processes on Earth, but its emergence and evolution remain unclear. Here we extrapolate models of present-day plate tectonics to the past and propose that since about three billion years ago the rise of continents and the accumulation of sediments at continental edges and in trenches has provided lubrication for the stabilization of subduction and has been crucial in the development of plate tectonics on Earth. We conclude that the two largest surface erosion and subduction lubrication events occurred after the Palaeoproterozoic Huronian global glaciations (2.45 to 2.2 billion years ago), leading to the formation of the Columbia supercontinent, and after the Neoproterozoic ‘snowball’ Earth glaciations (0.75 to 0.63 billion years ago). The snowball Earth event followed the ‘boring billion’—a period of reduced plate tectonic activity about 1.75 to 0.75 billion years ago that was probably caused by a shortfall of sediments in trenches—and it kick-started the modern episode of active plate tectonics.
DS1991-0472
1991
Sobolev, V.Fedorov, I.I., Chepurov, A.I., Osorgin, N.Y., Dokol, A.G., Sobolev, V.The experimental and thermodynamic modelling of C-O-H fluid in equilibrium with graphite and diamond at high pressuret parameters.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 320, No. 3, pp. 710-713RussiaExperimental mineralogy, Graphite, diamond
DS1993-0433
1993
Sobolev, V.Fedorov, I.I., Chepurov, A.I., Osorgin, N.Yu., Sokol, A.G., Sobolev, V.Experimental modeling and thermodydnamic analysis of C-O-H fluid in equilibrium with graphite and diamond at high pressures and temperatures.Doklady Academy of Sciences USSR, Earth Science Section, Vol. 321, No. 8, August 1993, pp. 163-166.Russia, Commonwealth of Independent States (CIS)Geothermometry, Graphite/diamond interface
DS1995-1727
1995
Sobolev, V.Shchukin, V.S., Sobolev, V., Larehence, V.A., Makhin, A.I.Geology of the diamond deposits in the Arkhangelsk region, RussiaSociety for Mining, Metallurgy and Exploration (SME) Meeting, Denver March 1995, abstractRussia, Commonwealth of Independent States (CIS), RussiaDiamond deposits
DS1975-0438
1976
Sobolev, V.K.Yermolenko, YU.P., Sobolev, V.K.Diamonds from Conglomerates of the Nadezhdin Suite Middle Devonian) of Northern Timan.Vyssh. Uchebn. Zaved. Izv. Geol. Razved., 1976, No. 12, PP. 159-161.RussiaBlank
DS1982-0574
1982
Sobolev, V.K.Sobolev, V.K., Stankovskiy, A.F.Carbonate Inclusions in Chrome Spinnellids from Kimberlite Sheets.Doklady Academy of Science USSR, Earth Science Section., Vol. 251, No. 6, PP. 140-141.RussiaXenoliths, Mineralogy
DS1983-0587
1983
Sobolev, V.K.Sobolev, V.K.Nature of Shells on Chrome Spinellid and Diamond Crystals from kimberlite.Doklady Academy of Sciences ACAD. NAUK USSR EARTH SCI. SECTION., Vol. 257, No. 1-6, PP. 148-151.RussiaDiamond, Genesis, Morphology, Crystallography
DS1983-0588
1983
Sobolev, V.K.Sobolev, V.K., Kiluev, I.A., et al.The Structural Typomorphism of North European Diamonds #1Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 269, No. 1, PP. 200-204.RussiaCrystallography
DS1983-0589
1983
Sobolev, V.K.Sobolev, V.K., Matsiuk, S.S.New Dat a on Titanian Pyropes in Connection with the Problem of Their Original Sources.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 270, No. 5, PP. 1195-1198.RussiaGarnet, Mineralogy, Genesis
DS1984-0696
1984
Sobolev, V.K.Sobolev, V.K., Klyuyev, YU.A., et al.The Structural Typomorphism of North European Diamonds #2Doklady Academy of Science USSR, Earth Science Section., Vol. 269, No. 1-6, SEPTEMBER PP. 115-118.RussiaDiamond Morphology
DS1995-1728
1995
Sobolev, V.K.Shchukin, V.S., Sobolev, V.K., et al.Geology of the diamond deposit of the Arkhangelsk region of RussiaAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint, No. 95-167, 12p.Russia, ArkangelskGeology, Deposit -Arkhangel
DS2002-0989
2002
Sobolev, V.K.Makeev, A.B., Kisel, S.I., Sobolev, V.K., Filippov, V.N., Bryanchaninova, N.I.Native metals in kimberlite pipe aureoles of the Arkhangelsk Diamondiferous provinceDoklady Earth Sciences, Vol. 385A, 6, pp. 714-8.Russia, Kola Peninsula, ArkangelskGeochemistry, Deposit - Arkangel area
DS1990-1387
1990
Sobolev, V.N.Sobolev, N.V., Mankenda, A., Kaminsky, F.V., Sobolev, V.N.Garnets from kimberlites of north-east Angola and relation of Their composition with diamond content.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 315, No. 5, pp. 1225-1229AngolaGarnets and diamonds, Mineralogy
DS1992-0485
1992
Sobolev, V.N.Fraracci, K.N., Taylor, L.A., Sobolev, N.V., Sobolev, V.N.Mineral chemistry of Diamondiferous eclogite xenoliths from the Mirkimberlite of the Yakutian kimberlite province, SiberiaGeological Society of America (GSA) Abstracts with programs, 1992 Annual, Vol. 24, No. 7, abstract p. A260Russia, Yakutia, SiberiaEclogites, Diamonds
DS1992-0786
1992
Sobolev, V.N.Jerde, E.A., Taylor, L.A., Crozaz, G., Sobolev, N.V., Sobolev, V.N.Diamondiferous eclogites from Yakutia Siberia: rare earth element evidence for a range of crustal protolithsGeological Society of America (GSA) Abstracts with programs, 1992 Annual, Vol. 24, No. 7, abstract p. A260Russia, YakutiaEclogites, Diamonds
DS1992-1448
1992
Sobolev, V.N.Sobolev, N.V., Mankenda, S.A., Kaminsky, F.V., Sobolev, V.N.Garnets from kimberlites of northeastern Angola and correlations between their compositions and diamond content.Doklady Academy of Sciences USSR, Earth Science Section, Vol. 315, pp. 238-242.AngolaGarnet mineralogy, Diamond content
DS1993-0750
1993
Sobolev, V.N.Jerde, E.A., Taylor, L.A., Crozaz, G., Sobolev, N.V., Sobolev, V.N.Diamondiferous eclogites from Yakutia, Siberia: evidence for a diversity ofprotolithsContribution to Mineralogy and Petrology, Vol. 114, No. 2, June pp. 189-202GlobalEclogites, Udachnaya pipe, chemistry, geobarometry
DS1994-1658
1994
Sobolev, V.N.Sobolev, V.N., Taylor, L.A., Snyder, G.A., Sobolev, N.V.Diamondiferous eclogites from the Udachnaya kimberlite pipe, YakutiaInternational Geology Review, Vol. 36, No. 1, Jan. pp. 42-64.Russia, YakutiaEclogites, Deposit -Udachnaya
DS1995-1796
1995
Sobolev, V.N.Sobolev, V.N., Taylor, L.A., Snyder et al.A unique metasomatised peridotite xenolith from the Siberian PlatformGeological Society of America (GSA) Abstracts, Vol. 27, No. 6, abstract p. A 48.Russia, SiberiaXenoliths, Metasomatism
DS1995-1797
1995
Sobolev, V.N.Sobolev, V.N., Taylor, L.A., Snyder, G.A., Sobolev, N.V.Diamondiferous eclogites from the Siberian Platform: samples with peridotitic signature? #2Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 552-554.Russia, SiberiaEclogites, Peridotites
DS1995-1798
1995
Sobolev, V.N.Sobolev, V.N., Taylor, L.A., Snyderm G.A.Diamondiferous eclogites and peridotites: are there petrogeneticrelationships?Geological Society of America (GSA) abstract, Vol. 27, No. 2, March p. 88.RussiaEclogites, Deposit -Mir
DS1995-1799
1995
Sobolev, V.N.Sobolev, V.N., Taylore, L.A., Snyder, G.A., PokhilenkoA unique metasomatised peridotite xenolith from the Mir kimberlite, Siberian PlatformProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 555-557.Russia, SiberiaXenolith -peridotite, Deposit -Mir
DS1995-1878
1995
Sobolev, V.N.Taylor, L.A., Snyer, G.A., Sobolev, V.N.Trace element chemistry of eclogitic inclusions in diamond and comparisons with host eclogite, Mir.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 625-627.Russia, YakutiaGeochemistry -eclogite, Deposit -Mir
DS1998-1375
1998
Sobolev, V.N.Sobolev, V.N., Taylor, L.A., Snyder, Jerde, NealMetasomatism of the mantle beneath Yakutia: a quantitative study of secondary chemistry and mineral..7th International Kimberlite Conference Abstract, pp. 835-7.Russia, YakutiaXenoliths, Deposit - Udachnaya
DS1999-0692
1999
Sobolev, V.N.Sobolev, N.V., Sobolev, V.N., Taylor, L.A.Significance of eclogitic and related parageneses of natural diamonds #1International Geology Review, Vol. 41, No. 2, Feb. pp. 129-40.Russia, YakutiaDiamond morphology, Eclogites, genesis
DS1999-0694
1999
Sobolev, V.N.Sobolev, V.N., Taylor, L.A., Sobolev, N.V.Quantifying the effects of metasomatism in mantle xenoliths: constraints from secondary chemistry ...International Geology Review, Vol. 41, No. 5, pp. 391-416.Russia, YakutiaMIneralogy, Geochemistry, eclogites, Deposit - Udachnaya
DS2000-0908
2000
Sobolev, V.N.Sobolev, N.V., Sobolev, V.N., Snyder, Yefimova, TaylorSignificance of eclogitic and related parageneses of natural diamonds #2Snyder, Neal, Ernst, Plan. Petrology and Geochemistry, pp. 15-26.GlobalDiamond - morphology, Diamond - genesis
DS1950-0084
1951
Sobolev, V.S.Sobolev, V.S.A Survey of the Geology of Diamond Deposits of Africa, Australia, Borneo and North America.Moskva: Gos. Izdat. Geol. Lit., 125P.South Africa, Australia, Borneo, United StatesGeology, Kimberley
DS1950-0325
1957
Sobolev, V.S.Buriv, A.P., Sobolev, V.S.Diamonds of SiberiaMoscow: Gosgeoltekhizdat., 158P.RussiaKimberlite
DS1950-0342
1957
Sobolev, V.S.Moor, G.G., Sobolev, V.S.The Problem of the Siberian KimberlitesMineral. Sb. L'vov Gos. University, No. 11, PP. 369-371.RussiaBlank
DS1960-0020
1960
Sobolev, V.S.Bobrievich, A.P., Smirnov, G.I., Sobolev, V.S.The Mineralogy of Xenoliths of a Grossularite Pyroxene Kyanite Rock from the Kimberlites of Yakutia.Geol. Series, Ussr, American Geological Institute Translation., No. 3, PP. 18-24.RussiaKimberlite
DS1960-0021
1960
Sobolev, V.S.Bobrievich, A.P., Smirnov, G.I., Sobolev, V.S.Eclogite Xenoliths With Diamond InclusionsDoklady Academy of Science USSR, Earth Science Section., Vol. 126, No. 1-6, PP. 581-583.RussiaKimberlite
DS1960-0218
1962
Sobolev, V.S.Bobrievich, A.P., Sobolev, V.S.Kimberlite Formations of the North Part of the Siberian Platform.In: The Petrography of The Ussr, PT. L, PP. 3L4-3L6.RussiaBlank
DS1960-0400
1963
Sobolev, V.S.Sobolev, V.S.Features of Volcanism of the Siberian PlatformPacific Science., Vol. 17, No. 4, PP. 452-457.RussiaDiatreme
DS1960-0500
1964
Sobolev, V.S.Sobolev, V.S., Sobolev, N.V.Xenoliths in the Kimberlites of Northern Yakutia. and Problems of the Structure of the Earth's Mantle.Doklady Academy of Science USSR, Earth Science Section., Vol. 158, PP. L08-LLL.RussiaBlank
DS1960-0604
1965
Sobolev, V.S.Sobolev, V.S., Sobolev, N.V.Xenoliths in Kimberlite of Northern Yakutia and the Structure of the Mantle.Doklady Academy of Science USSR, Earth Science Section., Vol. 158, No. 1-6, PP. 22-25.RussiaBlank
DS1960-0879
1967
Sobolev, V.S.Sobolev, V.S., Sobolev, N.V.Chromium and Chromium Bearing Minerals in Deep- Seated Xenoliths from Kimberlite Pipes.Geol. Rudn. Mestorozh., No. 9, PT. 2, PP. 10-16.RussiaBlank
DS1960-1213
1969
Sobolev, V.S.Sobolev, V.S.Kimberlite Genesis ProblemIavcei, Symposium Oxford., PP. 38-39.RussiaBlank
DS1960-1214
1969
Sobolev, V.S.Sobolev, V.S.Peridotites with Chromium Rich Garnets and Diamond Bearing Eclogites As the Most Deep Seated Xenoliths in Kimberlites.Iavcei, Symposium Oxford., PP. 45-47.RussiaBlank
DS1970-0603
1972
Sobolev, V.S.Sobolev, V.S., Sobolev, N.V., Lavrentyev, YU.G.Inclusions in Diamond from a Diamond Bearing EclogiteDoklady Academy of Sciences AKAD. NAUK SSSR., Vol. 207, PP. 164-167.RussiaDiamond Morphology
DS1970-0875
1974
Sobolev, V.S.Bakumenko, I.T., Sobolev, V.S.Inclusions in Minerals of Ultramafic Xenoliths from the Avacha Volcano.Doklady Academy of Science USSR, Earth Science Section., Vol. 218, No. 1-6, PP. 157-160.RussiaKimberlite
DS1975-0191
1975
Sobolev, V.S.Sobolev, V.S., Bazarova, T.YU., Yagi, K.Crystallization Temperatures of Wyomingite from Leucite HillContributions to Mineralogy and Petrology, Vol. 49, PP. 301-308.GlobalLeucite Hills, Leucite, Rocky Mountains
DS1975-0871
1978
Sobolev, V.S.Sobolev, V.S., Panina, L.I., Podgornikh, N.M.Crystallization Temperatures of Several Carbonatite Minerals from Siberia.I Symposio International De Carbonatitos, PP. 215-219.RussiaPetrology, Mineral Chemistry
DS1981-0388
1981
Sobolev, V.S.Sobolev, V.S., Sobolev, N.V.Yakut Diamonds: Scientific Problems Connected with Their Study.Journal of GEMMOLOGICAL SOCIETY of JAPAN., Vol. 8, No. 1-8, PP.RussiaBlank
DS1984-0692
1984
Sobolev, V.S.Sobolev, N.V., Efimova, E.S., Lavrentiev, I.G., Sobolev, V.S.Predominating Calc-silicate Association of Crystalline Inclusions in Diamonds from the South Australia Placers.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 274, No. 1, PP. 172-179.Australia, South AustraliaAlluvial Diamond Deposits, Mineralogy
DS1985-0636
1985
Sobolev, V.S.Sobolev, N.V., Yefimova, E.S., Lavrentyev, YU.G., Sobolev, V.S.Dominant calc-silicate association of crystalline inclusions in placer diamonds from southeastern AustraliaDoklady Academy of Science USSR, Earth Science Section, Vol. 275, April pp. 148-152AustraliaNew South Wales, Diamond Morphology
DS200812-0905
2008
Sobolev, V.S.Pokhilenko, L.N., Pokhilenko, N.P., Fedorov, L.I., Tomilenko, A.A., Usova, L.V., Fomina, L.N., Sobolev, V.S.Fluid regime pecularities of the lithosphere mantle of the Siberian Platform.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., 2008 pp. 122-136.Russia, SiberiaMantle chemistry
DS201112-1150
2011
Sobolev, V.S.Zaitsev, A.N., Sharygin, V.V., Sobolev, V.S., Kamenetsky, V.S., Kamenetsky, M.B.Silicate carbonate liquid immiscibility in 1917 eruption nephelinite lavas, Oldoinyo Lengai volcano, Tanzania: melt inclusion study.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterAfrica, TanzaniaCarbonatite
DS1986-0770
1986
Sobolev, V.V.Sobolev, V.V., Slobodskoy, V.Ya., Selyukov, S.N., Udoyev, A.A.Transformation of chaoite into other hydrocarbon phases.(Russian)Zapiski Vsesoy. Mineral. Obshchestva, (Russian), pp. 218-221RussiaBlank
DS1987-0698
1987
Sobolev, V.V.Sobolev, V.V.Diamond crystallization in natureCombust. Explos. Shock Waves, Vol. 23, No. 1, Jan-Feb pp. 83-86GlobalBlank
DS1987-0699
1987
Sobolev, V.V.Sobolev, V.V.Diamond crystallization in nature.(Russian)Fiz. Goreniya Vzryva, (Russian), Vol. 23, No. 1, pp. 91-95RussiaDiamond, Crystallography
DS1994-1659
1994
Sobolev, V.V.Sobolev, V.V.Crystallization of diamond particles in the interstellar mediumGeochemistry International, Vol. 31, No. 4, pp. 103-106.GlobalMeteorites, Diamond morphology
DS1993-1247
1993
Sobolev N.V.Pokhilenko, N.P., Sobolev N.V., Boyd, F.R., Pearson, D.G., Shimizum N.Megacrystalline pyrope peridotites in the lithosphere of the Siberianplatform: mineralogy, geochemical pecularities and the problem of their origin.Russian Geology and Geophysics, Vol. 34, No. 1, pp. 1-12.Russia, Commonwealth of Independent States (CIS), SiberiaPyrope peridotites, Siberian Platform, Geochemistry
DS1997-0346
1997
Soboleva, S.Ferraris, G., Khomyakov, A.P., Belluso, E., Soboleva, S.Polysomatic relationships in some titanosilicates occurring in the hyperagpaitic alkaline rocks Kola Pen.Proceedings 30th. I.G.C., Pt. 16, pp. 17-27.Russia, Kola PeninsulaAlkaline rocks
DS1982-0575
1982
Soboleva, S.V.Soboleva, S.V., et al.Characteristics of Phlogopite of Mantle OriginInternational Geology Review, Vol. 24, No. 1, PP. 35-40.RussiaObnazhennaya, Pyrope Garnet, Genesis
DS1990-1638
1990
Soboleva, S.V.Zinchuk, N.N., Soboleva, S.V., Kotelnikov, D.D., Antonyuk, B.P.Properties of layer silicates from kimberlite and host rocks in zones actively affected by trap magmatism (illustrated by Yakutia)Doklady Academy of Science USSR, Earth Science Section, Vol. 305, No. 2, Sept. pp. 160-162RussiaKimberlite, Skarns
DS2001-0698
2001
Sobolov, N.V.Logvinova, A.M., Zedgenizov, D.A., Sobolov, N.V.Pyroxenite paragenesis of abundant mineral and probable fluid inclusions in microdiamonds from Mir kimberliteDoklady Academy of Sciences, Vol. 380, No. 7, Sept-Oct. pp.795-800.Russia, SiberiaMineralogy - micro diamonds, Deposit - Mir
DS1991-1628
1991
Sobolyev, V.K.Sobolyev, V.K.The problem of primary source of Brasil type diamonds (the case history of discovery of diamond deposits in the Arkhangelsk region)Proceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 553-555RussiaPSSD (primary source of spheroidal diamonds), Diamond genesis
DS1982-0612
1982
Sobornov, O.P.Ukhanov, A.V., Sobornov, O.P., et al.Thorium and Uranium Contents in Kimberlites of Siberia and Africa Based on the Results of New Gamma Spectrometric Determinations.Geochemistry International (Geokhimiya)., No. 8, AUGUST, PP. 1204-1210.Russia, South AfricaMineral Chemistry
DS1987-0700
1987
Sobornov, O.P.Sobornov, O.P., Zolotukhina, T.M.Radio elements in standard samples pertaining to magmatic rocks included In the single system of the USSR state standard samplesGeostandard Newsletter, Vol. 11, No. 1, pp. 123-126RussiaAnorthorosite, harzburgite, kimberlite, Spectrometry
DS2000-0910
2000
Sobouti, F.Sobouti, F., Hamed, J.A.Thermo-mechanical modeling of subduction of continental lithosphereGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000, 2p. abstract.MantleGeodynamics, tectonics
DS2001-1098
2001
Sobouti, F.Sobouti, F., Ghods, A., Arkani-Hamed, J.On the advection of sharp material interfaces in geodynamic problems: entrainment of the D layer.Journal of Geodynamics, Vol. 31, No. 5, pp. 459-79.MantleConvection - chemistry
DS200812-0502
2008
Sobovlev, A.V.Ionov, D.A., Sobovlev, A.V.Geochemical fingerprinting of the lithospheric mantle using high precision olivine analyses.Goldschmidt Conference 2008, Abstract p.A410.MantleXenolith chemistry
DS1984-0697
1984
Sobzcak, L.W.Sobzcak, L.W., Overton, A.Shallow and deep crustal structure of the western Sverdrup Basin, ArcticCanada.Canadian Journal of Earth Sciences, Vol. 21, p. 902-19.Northwest TerritoriesGeophysics - Gravity
DS1950-0303
1956
Soc. International Forestiere Et Miniere Du CongoSoc. International Forestiere Et Miniere Du CongoHistory and Founding of Company into African AffairsBruxelles: L. Cuypers, 209P.Democratic Republic of Congo, Central AfricaKasai, Diamonds, Mining, Kimberley
DS1981-0245
1981
Sochneva, E.G.Konstantinovskiy, A.A., Sochneva, E.G., et al.Pyrope and Picroilmenite Finds in the Riphean Rocks of the Northern Part of the Siberian PlatformDoklady Academy of Science USSR, Earth Science Section., Vol. 247, No. 1-6, PP. 147-149.RussiaHeavy Minerals, Prospecting
DS1970-0604
1972
Sochurek, H.Sochurek, H.What It Is Like to Live in Siberia During WinterSmithsonian Magazine., Vol. 4, No. 10, PP. 44-52.RussiaBlank
DS1997-1076
1997
Societe GeneraleSociete GeneraleReunion Mining - performance outline Skorpion featured not diamondsSociete Generale Promotional, 12p.ZimbabweNews item - promotional, Reunion Mining PLC.
DS1860-0038
1867
Society Arts Journal of LondonSociety Arts Journal of LondonPrecious Stones at the Cape of Good HopeSociety Arts Journal of London, Vol. 15, Oct. 4TH., P. 703.Africa, South Africa, Griqualand West, Orange RiverAlluvial placers, History, Diamonds Notable
DS1860-0057
1868
Society Arts Journal of LondonSociety Arts Journal of LondonDiamonds at the Cape Colony. #2Society Arts Journal of London, Vol. 16, PP. 849-850; PP. 854-855; ALSO Vol. 17, P. 46.Africa, South AfricaCurrent Activities
DS1860-0194
1873
Society Arts Journal of LondonSociety Arts Journal of LondonCape Diamonds Vaal River, Waldreck's PlantSociety Arts Journal of London, Vol. 21, P. 155.Africa, South Africa, Cape ProvinceDiamonds Notable
DS1860-0241
1875
Society Arts Journal of LondonSociety Arts Journal of LondonNotes on Diamonds from the CapeSociety Arts Journal of London, Vol. 23, P. 930.Africa, South AfricaDiamond Occurrence
DS1998-1376
1998
Society for Mining, Metallurgy and Exploration (SME).Society for Mining, Metallurgy and Exploration (SME).Remediation of historical mine sites - technical summaries andbibliographySociety for Mining, Metallurgy and Exploration (SME)., 136p. $ 30.00GlobalBook - ad, Environment - remediation
DS1994-1660
1994
Society of Economic GeologistsSociety of Economic GeologistsAssays: conflict between quality and cost... forum reviewSeg Newsletter, No. 16, January pp. 16, 17GlobalGeochemistry, Sampling -assays
DS1996-1343
1996
Society of Economic GeologistsSociety of Economic GeologistsActivity in Norway at a low level... costs and rights of LappsSeg Newsletter, No. 26, July, p. 39.NorwayNews item, RTZ, Ashton, Monopros
DS1996-1344
1996
Society of Economic GeologistsSociety of Economic GeologistsNorthern Europe - exploration review... Alcastone Mining.. applying for diamond exploration in Sweden.Seg Newsletter, No. 26, July, p. 38.SwedenNews item, Alcastone Mining
DS1996-1345
1996
Society of Economic GeologistsSociety of Economic GeologistsMinish FIn land Oy (Ashton Mining) contesting Alcastone Mining applicationSeg Newsletter, No. 26, July, p. 38.SwedenNews item, Ashton Mining Ltd.
DS1996-1346
1996
Society of Economic GeologistsSociety of Economic GeologistsGeoforum AB, RTZ and NordEx AB all involved in exploration concessions...Seg Newsletter, No. 26, July, p. 38.SwedenNews item, Geoforum AB, RTZ, NordEX
DS200912-0709
2008
Society of Economic GeologistsSociety of Economic GeologistsDiamonds and kimberlites 1905-2007. All papers from Economic Geology issues.Society of Economic Geology, Compilation series CD rom $ 75.00 USGlobalDiamond papers
DS2003-1309
2003
Society of Economic Geologists University of Toronto Student ChapterSociety of Economic Geologists University of Toronto Student ChapterKimberlites and diamond exploration. Overview, petrography, mineral inclusionsSeg University Of Toronto Email [email protected], March 7,8th. 2 day $ 500.TorontoShort Course - diamond exploration
DS2000-0911
2000
Society of Exploration Geophysics Australia PreviewSociety of Exploration Geophysics Australia PreviewAdvances in seismic processing 1990-2000Seg Australia Preview, August pp. 17-26.GlobalGeophysics - seismics ( not specific to diamonds)
DS1993-1501
1993
Society of Mining Geologists of JapanSociety of Mining Geologists of JapanFerro-manganese depositsResource Geology of Japan, No. 17GlobalBook -table of contents, Ferro-manganese deposits
DS202111-1768
2021
Sodelund, U.Gong, Z., Evans, D.A.D., Youbi, N., Lahna, A.A., Sodelund, U., Malek, M.A., Wen, B., Jing, X., Ding, J., Boumedhdi, M.A., Ernst, R.E.Reorienting the West African craton in Paleoproterozoic-Msoproterozoic supercontinent Nuna.Geology, Vol. 49, 10, pp. 1171-1176. pdfAfrica, west AfricaNuna

Abstract: The location of the West African craton (WAC) has been poorly constrained in the Paleoproterozoic-Mesoproterozoic supercontinent Nuna (also known as Columbia). Previous Nuna reconstruction models suggested that the WAC was connected to Amazonia in a way similar to their relative position in Gondwana. By an integrated paleomagnetic and geochronological study of the Proterozoic mafic dikes in the Anti-Atlas Belt, Morocco, we provide two reliable paleomagnetic poles to test this connection. Incorporating our new poles with quality-filtered poles from the neighboring cratons of the WAC, we propose an inverted WAC-Amazonia connection, with the northern WAC attached to northeastern Amazonia, as well as a refined configuration of Nuna. Global large igneous province records also conform to our new reconstruction. The inverted WAC-Amazonia connection suggests a substantial change in their relative orientation from Nuna to Gondwana, providing an additional example of large-magnitude cumulative azimuthal rotations between adjacent continental blocks over supercontinental cycles.
DS1910-0311
1912
Sodenstern, E. VON.Sodenstern, E. VON.Auf den Diamant feldern in Suedwest. Pomona und AnderesKol. Heimat., Vol. 6, No. 4, PP. 2-3.Southwest Africa, NamibiaDiamonds, Occurrences, Littoral Diamond Placers
DS1975-1231
1979
Soderberg, R.K.Soderberg, R.K., Keller, G.R., Braile, L.W., Hinze, W.J., et al.A Gravity and Tectonic Study of the Rough Creek Fault Zone And Related Features.National Technical Information Service NUREG CR/1014, PP. 134-164.GlobalMid Continent, New Madrid
DS1981-0389
1981
Soderberg, R.K.Soderberg, R.K., Keller, G.R.Geophysical Evidence for Deep Basin in Western KentuckyAmerican Association of Petroleum Geologists Bulletin., Vol. 65, PP. 226-234.GlobalMid-continent
DS201012-0077
2010
SoderlundBuchan, K.L., Ernst, R.E., Bleeker, W., Davis, W.J., Villeneuve, M., Van Breeman, O., Hamilton, SoderlundMap of Proterozoic magmatic events in the Slave Craton, Wopmay Orogen and environs, Canadian Shield.International Dyke Conference Held Feb. 6, India, 1p. AbstractCanada, Northwest TerritoriesMagmatism
DS2001-0538
2001
Soderlund, U.Johannsen, L., Moller, C., Soderlund, U.Geochronology of eclogite facies metamorphism in the Sveconorwegian Province of southwest Sweden.Precambrian Research, Vol. 106, No. 3-4, Mar. 1, pp. 261-76.SwedenEclogites
DS201012-0185
2010
Soderlund, U.Ernst, R.E., Bleeker, W., Soderlund, U., Hamilton, M.A., Sylvester, P.J., Chamberlain, K.R.Using the global dolerite dyke swarm record to reconstruct supercontinents back to 2.7 Ga.International Dyke Conference Held Feb. 6, India, 1p. AbstractGlobalPangea
DS201012-0236
2010
Soderlund, U.Gladkochub, D.P., Pisarevsky, S.A., Ernst, R., Donskaya, T.V., Soderlund, U., Mazukabzov, A.M., Hanes, J.Large igneous province of about 1750 Ma in the Siberian Craton.Doklady Earth Sciences, Vol. 430, 2, pp. 163-167.RussiaMagmatism
DS201012-0262
2010
Soderlund, U.Halls, H.C., Lovette, A., Soderlund, U., Hamilton, M.A.Paleomagnetism and U Pb geochronology from the western end of the Grenville dyke swarm and the question of true polar wander during the Ediacaran.International Dyke Conference Held Feb. 6, India, 1p. AbstractUnited States, CanadaAlkaline rocks, complexes
DS201312-0241
2013
Soderlund, U.El Bahat, A., Ikenne, M., Soderlund, U., Cousens, B., Youbi, N., Ernst, R., Soulaimani, A., El Janati, M., Hafid, A.U PB baddeleyite ages and geochemistry of dolerite dykes in the Bas Draa In lier of the Anti-Atlas of Morocco: newly identified Ma event in the West African craton.Lithos, Vol. 174, pp. 85-98.Africa, MoroccoGeochronology
DS201312-0248
2013
Soderlund, U.Ernst, R.E., Bleeker, W., Soderlund, U., Kerr, A.C.Large igneous provinces and supercontinents: toward completing the plate tectonic revolution.Lithos, Vol. 174, pp. 1-14.PangeaLIP
DS201312-0511
2013
Soderlund, U.Kouyate, D., Soderlund, U., Youbi, N., Ernst, R., Hafid, A., Ikeene, M., Soulaimani, A., Betrand, H., El Janati, M., Rkha, C.U Pb baddeleyite and zircon ages of 2040 Ma, 1650 Ma and 885 Ma on dolerites in the West African Craton ( Anti-Atlas inliers) : possible links to break up of Precambrian supercontinents.Lithos, Vol. 174, pp. 71-84.AfricaGeochronology
DS201312-0650
2013
Soderlund, U.Nilsson, M.K.M., Klausen, M.B., Soderlund, U., Ernst, R.E.Precise U Pb ages and geochemistry of Paleoproterozoic mafic dykes from southern West Greenland: linking the North Atlantic and the Dharwar cratons.Lithos, Vol. 174, pp. 255-270.Europe, Greenland, IndiaGeochronology
DS201312-0899
2013
Soderlund, U.Tait, J., Straathof, G., Soderlund, U., Ernst, R.E., Key, R., Jowitt, S.M., Lo, K., Dahmada, M.E.M., N'Diaya, O.The Ahmeyim Great Dyke of Mauritania: a newly dated Archean intrusion.Lithos, Vol. 174, pp. 323-332.Africa, MauritaniaGeochronology
DS201312-0999
2013
Soderlund, U.Youbi, N., Kouyate, D., Soderlund, U., Ernst, R.E., Soulaimani, A., Hafid, A., Ikenne, M., El Bahat, A., Betrand, H., Chaham, K.R., Ben Abbou, M., Mortaji, A., El Ghorfi, M., Zouhair, M., El Janati, M.The 1750 Ma magmatic event of the West African Craton ( Anti-Atlas) Morocco.Precambrian Research, Vol. 236, pp. 106-123.Africa, MoroccoDike swarms
DS201606-1084
2016
Soderlund, U.Evans, D.A.D., Trindade, R.I.F., Catelani, E.L., D'Agrella-Filho, Heaman, L.M., Oliveira, E.P., Soderlund, U., Ernst, R.E., Smirnovm A.V., Salminen, J.M.Return to Rodinia? Moderate to high paleolatitude of the Sao Francisco/Congo craton at 920 Ma.Geological Society of London Special Publication Supercontinent Cycles through Earth History., Vol. 424, pp. 167-190.South America, BrazilSupercontinents

Abstract: Moderate to high palaeolatitudes recorded in mafic dykes, exposed along the coast of Bahia, Brazil, are partly responsible for some interpretations that the São Francisco/Congo craton was separate from the low-latitude Rodinia supercontinent at about 1050 Ma. We report new palaeomagnetic data that replicate the previous results. However, we obtain substantially younger U-Pb baddeleyite ages from five dykes previously thought to be 1.02- 1.01 Ga according to the 40 Ar/ 39 Ar method. Specifically, the so-called 'A-normal' remanence direction from Salva-dor is dated at 924.2 + 3.8 Ma, within error of the age for the 'C' remanence direction at 921.5 + 4.3 Ma. An 'A-normal' dyke at Ilhéus is dated at 926.1 + 4.6 Ma, and two 'A-normal' dykes at Olivença have indistinguishable ages with best estimate of emplacement at 918.2 + 6.7 Ma. We attribute the palaeomagnetic variance of the 'A-normal' and 'C' directions to lack of averaging of geomagnetic palaeosecular variation in some regions. Our results render previous 40 Ar/ 39 Ar ages from the dykes suspect, leaving late Mesoproterozoic palaeolatitudes of the São Francisco/Congo craton unconstrained. The combined 'A-normal' palaeomagnetic pole from coastal Bahia places the São Francisco/Congo craton in moderate to high palaeolatitudes at c. 920 Ma, allowing various possible positions of that block within Rodinia. Despite more than two decades of intense global research, the configuration of Neoproterozoic supercontinent Rodinia remains enigmatic. Following the first global synthesis by Hoffman (1991), most models include a central location for Laurentia, flanked by 'East' Gondwana-Land cra-tons along its proto-Cordilleran margin and 'West'
DS201607-1295
2016
Soderlund, U.Ernst, R.E., Hamilton, M.A., Soderlund, U., Hanes, J.A., Gladkochub, D.P., Okrugin, A.V., Kolotilina, T., Mekhonoshin, A.S., Bleeker, W., LeCheminant, A.N., Buchan, K.L., Chamberlain, K.R., Didenko, A.N.Long lived connection between southern Siberia and northern Laurentia in the Proterozoic.Nature Geoscience, Vol. 9, 6, pp. 464-469.Canada, RussiaProterozoic

Abstract: Precambrian supercontinents Nuna-Columbia (1.7 to 1.3 billion years ago) and Rodinia (1.1 to 0.7 billion years ago) have been proposed. However, the arrangements of crustal blocks within these supercontinents are poorly known. Huge, dominantly basaltic magmatic outpourings and intrusions, covering up to millions of square kilometres, termed Large Igneous Provinces, typically accompany (super) continent breakup, or attempted breakup and offer an important tool for reconstructing supercontinents. Here we focus on the Large Igneous Province record for Siberia and Laurentia, whose relative position in Nuna-Columbia and Rodinia reconstructions is highly controversial. We present precise geochronology—nine U -Pb and six Ar -Ar ages—on dolerite dykes and sills, along with existing dates from the literature, that constrain the timing of emplacement of Large Igneous Province magmatism in southern Siberia and northern Laurentia between 1,900 and 720 million years ago. We identify four robust age matches between the continents 1,870, 1,750, 1,350 and 720 million years ago, as well as several additional approximate age correlations that indicate southern Siberia and northern Laurentia were probably near neighbours for this 1.2-billion-year interval. Our reconstructions provide a framework for evaluating the shared geological, tectonic and metallogenic histories of these continental blocks.
DS201612-2350
2016
Soderlund, U.Youbi, N., Ernst, R.E., Soderlund, U., Boumehdi, M.A., Bensalah, M.K., Aarab, E.M.Morocco, North Africa: a dyke swarm bonanza.Acta Geologica Sinica, Vol. 90, July abstract p. 15.Africa, MoroccoDykes
DS201805-0952
2017
Soderlund, U.Ikenne, M., Lahna, A.A., Soderlund, U., Tassinar, C.C.G., Ernst, R.E., Pin, Ch., Youbi, N., El Aouli, EH., Hafid, A., Admou, H., Mata, J., Bouougri, EH., Boumehdi, M.A.New Mesoproterozoic age constraints for the Taghdout Group, Anti-Atlas ( Morocco): toward a new lithostratigra[hic framework for the Precambrian in the NW margin of the West African Craton.The First West African Craton and Margins International Workshop WACMA, Held Apr. 24-29. 1p. AbstractAfrica, Moroccogeochronology
DS201811-2605
2018
Soderlund, U.Salminen, J., Hanson, R., Evans, D.A.D., Gong, Z., Larson, T., Walker, O., Gumsley, A., Soderlund, U., Ernst, T.Direct Mesoproterozoic connection of the Congo and Kalahari cratons in proto-Africa: strange attractors across supercontinental cycles.Geology, doi.org/10.1130/G45294.1 4p.Africacraton

Abstract: Mobilistic plate-tectonic interpretation of Precambrian orogens requires that two conjoined crustal blocks may derive from distant portions of the globe. Nonetheless, many proposed Precambrian cratonic juxtapositions are broadly similar to those of younger times (so-called “strange attractors”), raising the specter of bias in their construction. We evaluated the possibility that the Congo and Kalahari cratons (Africa) were joined together prior to their amalgamation along the Damara-Lufilian-Zambezi orogen in Cambrian time by studying diabase dikes of the Huila-Epembe swarm and sills in the southern part of the Congo craton in Angola and in Namibia. We present geologic, U-Pb geochronologic, and paleomagnetic evidence showing that these two cratons were directly juxtaposed at ca. 1.1 Ga, but in a slightly modified relative orientation compared to today. Recurring persistence in cratonic connections, with slight variations from one supercontinent to the next, may signify a style of supercontinental transition similar to the northward motion of Gondwana fragments across the Tethys-Indian oceanic tract, reuniting in Eurasia.
DS201811-2609
2018
Soderlund, U.Stark, J.C., Wilde, S.A., Soderlund, U., Li, Z-X., Rasmussen, B., Zi, J-W.First evidence of Archean mafic dykes at 2.62 Ga in the Yilgarn Craton, Western Australia: links to cratonisation and the Zimbabwe craton.Precambrian Research, Vol. 317, pp. 1-13.Australia, Africa, Zimbabwecraton

Abstract: The Archean Yilgarn Craton in Western Australia hosts at least five generations of Proterozoic mafic dykes, the oldest previously identified dykes belonging to the ca. 2408-2401?Ma Widgiemooltha Supersuite. We report here the first known Archean mafic dyke dated at 2615?±?6?Ma by the ID-TIMS U-Pb method on baddeleyite and at 2610?±?25?Ma using in situ SHRIMP U-Pb dating of baddeleyite. Aeromagnetic data suggest that the dyke is part of a series of NE-trending intrusions that potentially extend hundreds of kilometres in the southwestern part of the craton, here named the Yandinilling dyke swarm. Mafic magmatism at 2615?Ma was possibly related to delamination of the lower crust during the final stages of assembly and cratonisation, and was coeval with the formation of late-stage gold deposit at Boddington. Paleogeographic reconstructions suggest that the Yilgarn and Zimbabwe cratons may have been neighbours from ca. 2690?Ma to 2401?Ma and if the Zimbabwe and Kaapvaal cratons amalgamated at 2660-2610?Ma, the 2615?Ma mafic magmatism in the southwestern Yilgarn Craton may be associated with the same tectonic event that produced the ca. 2607-2604?Ma Stockford dykes in the Central Zone of the Limpopo Belt. Paleomagnetic evidence and a similar tectonothermal evolution, including coeval low-pressure high-temperature metamorphism, voluminous magmatism, and emplacement of mafic dykes, support a configuration where the northern part of the Zimbabwe Craton was adjacent to the western margin of the Yilgarn Craton during the Neoarchean. Worldwide, reliably dated mafic dykes of this age have so far been reported from the Yilgarn Craton, the Limpopo Belt and the São Francisco Craton.
DS201812-2828
2018
Soderlund, U.Kastek, N., Ernst, R.E., Cousens, B.L., Kamo, S.L., Bleeker, W., Soderlund, U., Baragar, W.R.A., Sylvester, P.U-Pb geochronology and geochemistry of the Povungnituk Group of the Cape Smith Belt: part of a craton scale circa 2.0 Ga Minto-Povungnituk Large Igneous Province, northern Superior craton. Lithos, Vol. 320-321, pp. 315-331.Canada, Quebeccarbonatite

Abstract: Magmatism of the Povungnituk Group of the Cape Smith Belt, northern Superior craton, was formed in three stages: (i)early alkaline magmatism and associated carbonatites (undated), (ii) a main flood basalt sequence (Beauparlant Formation) (constrained between 2040 and 1991?Ma), and (iii) a late stage alkaline pulse (Cecilia Formation) (ca. 1959?Ma). We suggest that the main stage of magmatic activity (middle pulse) was of short duration. A new UPb baddeleyite age of 1998?±?6?Ma is obtained from a dolerite sill intruding the uppermost section of the Beauparlant Formation. This age has regional significance because it matches the previously obtained 1998?±?2?Ma age for the Watts Group (Purtuniq) ophiolite of the northern Cape Smith Belt and the 1998?±?2?Ma?U-Pb age of the Minto dykes intruding the craton to the south. These coeval units, along with additional units correlated on paleomagnetic grounds (Eskimo Formation), are interpreted to define a large igneous province (LIP), extending over an area of >400,000?km2, which we herein define as the Minto-Povungnituk LIP. Geochemical comparison between the Watts Group ophiolite, Minto dykes and the mafic Povungnituk Group shows significant differences allowing these data to be divided into two groups and domains within the LIP. A northern domain, comprising the Povungnituk and Watts groups, shows mixing between a depleted mantle source and a more enriched mantle plume-sourced melt. A southern domain comprising the Minto dykes and the paleomagnetically linked Eskimo Formation shows signs of an even more enriched source, while these magmas also show the effect of crustal contamination. Two distinct source mechanisms can be responsible for the observed geochemical differences between the two domains. First, a difference in lithospheric sources, where melting of different portions of Superior craton lithosphere caused the different melt signatures in the interior of the craton. In this case magmatism in the two domains is only related by having the same heat source (e.g.,a mantle plume) interpreted to be located on the northwestern side of the northern Superior craton. Second, two distinct deep mantle sources that remained separated within the ascending plume. This is analogous to some current hotspots interpreted to sample both large low shear velocity provinces (LLSVP) and adjacent ambient deep mantle. This latter interpretation would allow for the use of bilateral chemistry in LIPs as a potential tool for the recognition and mapping of the LLSVP boundaries throughout Earth's history.
DS201902-0261
2019
Soderlund, U.Baratoux, L., Soderlund, U., Ernst, R.E., de Roever, E., Jessell, M.W., Kamo, S., Naba, S., Perrouty, S., Metelka, V., Yatte, D., Grenholm, M., Diallo, D.P., Ndiaye, P.M., Dioh, E., Cournede, C., Benoit, M., Baratoux, D., Youbi, N., Rousse, S., BendaoudNew U-Pb baddeleyite ages of mafic dyke swarms of the West African and Amazonian cratons: implication for their configuration in supercontinents through time.Dyke Swarms of the World: a modern perspective, Srivastava et al. eds. Springer , pp. 263-314.Africa, West Africa, South Americageochronology

Abstract: Eight different generations of dolerite dykes crosscutting the Paleoproterozoic basement in West Africa and one in South America were dated using the high precision U-Pb TIMS method on baddeleyite. Some of the individual dykes reach over 300 km in length and they are considered parts of much larger systems of mafic dyke swarms representing the plumbing systems for large igneous provinces (LIPs). The new U-Pb ages obtained for the investigated swarms in the southern West African Craton (WAC) are the following (oldest to youngest): 1791?±?3 Ma for the N010° Libiri swarm, 1764?±?4 Ma for the N035° Kédougou swarm, 1575?±?5 for the N100° Korsimoro swarm, ~1525-1529 Ma for the N130° Essakane swarm, 1521?±?3 Ma for the N90° Sambarabougou swarm, 915?±?7 Ma for the N070° Oda swarm, 867?±?16 Ma for the N355° Manso swarm, 202?±?5 Ma and 198?±?16 Ma for the N040° Hounde swarm, and 200?±?3 Ma for the sills in the Taoudeni basin. The last ones are related to the Central Atlantic Magmatic Province (CAMP) event. The Hounde swarm is oblique to the dominant radiating CAMP swarm and may be linked with the similar-trending elongate Kakoulima intrusion in Guinea. In addition, the N150° Käyser swarm (Amazonian craton, South America) is dated at 1528?±?2 Ma, providing a robust match with the Essakane swarm in a standard Amazonia-West African craton reconstruction, and resulting in a combined linear swarm >1500 km by >1500 km in extent. The Precambrian LIP barcode ages of c. 1790, 1765-1750, 1575, 1520, 915. 870 Ma for the WAC are compared with the global LIP record to identify possible matches on other crustal blocks, with reconstruction implications. These results contribute to the refinement of the magmatic ‘barcode’ for the West African and Amazonian cratons, representing the first steps towards plausible global paleogeographic reconstructions involving the West African and Amazonian cratons.
DS201902-0316
2019
Soderlund, U.Salminen, J., Hanson, R., Evans, D.A.D., Gong, Z., Larson, T., Walker, O., Gumsley, A., Soderlund, U., Ernst, R.Direct Mesoproterozoic connection of the Congo and Kalahari cratons in proto-Africa: strange attractors across supercontinental cycles.Geology, Vol. 46, pp. 1101-1104.Africa, Angola, Namibiacraton

Abstract: Mobilistic plate-tectonic interpretation of Precambrian orogens requires that two conjoined crustal blocks may derive from distant portions of the globe. Nonetheless, many proposed Precambrian cratonic juxtapositions are broadly similar to those of younger times (so-called “strange attractors”), raising the specter of bias in their construction. We evaluated the possibility that the Congo and Kalahari cratons (Africa) were joined together prior to their amalgamation along the Damara-Lufilian-Zambezi orogen in Cambrian time by studying diabase dikes of the Huila-Epembe swarm and sills in the southern part of the Congo craton in Angola and in Namibia. We present geologic, U-Pb geochronologic, and paleomagnetic evidence showing that these two cratons were directly juxtaposed at ca. 1.1 Ga, but in a slightly modified relative orientation compared to today. Recurring persistence in cratonic connections, with slight variations from one supercontinent to the next, may signify a style of supercontinental transition similar to the northward motion of Gondwana fragments across the Tethys-Indian oceanic tract, reuniting in Eurasia.
DS201902-0317
2019
Soderlund, U.Samal, A.K., Srivastava, R.K., Ernst, R.E., Soderlund, U.Neoarchean-Mesoproterozoic mafic dyke swarms of the Indian shield mapped using google Earth images and ArcGIStm, and links with Large Igneous Provinces.Srivastava: Dyke Swarms of the World: a Modern Perspective, Springer, researchgate 56p. PdfIndiadykes

Abstract: We present dyke swarm maps generated using Google Earth™ images, ArcGIS™, field data, and available geochronological ages of Neoarchean-Mesoproterozoic (ranging in age from ~2.80 to ~1.10 Ga) mafic dyke swarms and associated magmatic units of the different Archean cratons of the Indian shield which represent the plumbing system of Large Igneous Provinces (LIPs). The spatial and temporal distributions together with the trends of the dyke swarms provide important informations about geodynamics. Twenty four dyke swarms (17 have been precisely dated), mostly mafic in nature, have been mapped from the different cratons and named/re-named to best reflect their location, trend, distribution and distinction from other swarms. We have identified 14 distinct magmatic events during the Neoarchean-Mesoproterozoic in the Indian shield. These intraplate magmatic events (many of LIP scale) of the Indian shield and their matches with coeval LIPs on other crustal blocks suggest connections of the Indian shield within known supercontinents, such as Kenorland/Superia (~2.75-2.07 Ga), Columbia/Nuna (1.90-1.38 Ga), and Rodinia (1.20-0.72 Ga). However, further detailed U-Pb geochronology and associated paleomagnetism are required to come to any definite constraints on the position of the Indian cratons within these supercontinents.
DS201905-1077
2018
Soderlund, U.Soderlund, U., Bleeker, W., Demirer, K., Srivastava, R.K., Hamilton, M., Nilsson, M., Personen, L.J., Samal, A.K., Jayananda, M., Ernst, R.E., Srinivas, M.Emplacement ages of Paleoproterozoic mafic dyke swarms in eastern Dharwar craton, India: implications for paleoreconstructions and support for a ~30 degree change in dyke trends from south to north.Precambrian Research, doi.org/10.1016/ j.precamres.2018.12.017Indiacraton

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

Abstract: Based on trend, cross-cutting relationships and U-Pb dating, Precambrian mafic dykes in the Singhbhum craton, earlier collectively identified as ‘Newer Dolerite Swarm’ have been separated into seven distinct swarms, which are thought to be the plumbing systems for Large Igneous Provinces (LIPs). These Singhbhum swarms range in age from ?2.80 Ga to ?1.76 Ga, and include the ?2.80 Ga NE-SW trending Keshargaria swarm, ?2.75-2.76 Ga NNE-SSW to NE-SW trending Ghatgaon swarm, the ?2.26 Ga NE-SW to ENE-WSW trending Kaptipada swarm (based on a new U-Pb ID-TIMS age 2256 ± 6 Ma), the ?1.77 Ga WNW-ESE trending Pipilia swarm, the early-Paleoproterozoic E-W to ENE-WSW trending Keonjhar swarm, the middle-Paleoproterozoic NW-SE to NNW-SSE trending Bhagamunda swarm, and the late-Paleoproterozoic N-S to NNE-SSW trending Barigaon swarm. Two of the Singhbhum swarms, the ?2.26 Ga Kaptipada and ?1.77 Ga Pipilia, are closely matched with the ?2.26-2.25 Ga Ippaguda-Dhiburahalli and ?1.79 Ga Pebbair swarms, respectively, of the eastern Dharwar craton. The correlations suggest that the Singhbhum and Dharwar cratons were close enough at these times to share two reconstructed LIPs, a 2.26-2.25 Ga Kaptipada- Ippaguda-Dhiburahalli LIP and a 1.79-1.77 Ga Pipilia-Pebbair LIP, and if so, both swarms must be present in the intervening Bastar craton (candidates are proposed). Also, the 2.76-2.75 Ga Ghatgaon swarm of the Singhbhum craton can be provisionally correlated with ?2.7 Ga Keshkal swarm of the Bastar craton. The 2.26-2.25 Ga Kaptipada-Ippaguda-Dhiburahalli LIP of the Singhbhum-Bastar-Dharwar reconstruction has age matches in the Vestfold Hills of Antarctica (?2.24 Ga dykes), the Kaapvaal craton (the ?2.25-2.23 Ga Hekpoort lavas) and perhaps the Zimbabwe craton (2.26 Ga Chimbadzi troctolite intrusions). The 1.76-1.79 Ga Pipilia-Pebbair LIP of the Singhbhum-Bastar-Dharwar reconstruction has age matches in the North China, Australian Shield, Amazonian, Rio de Plata and Sarmatia cratons. The relevance of these matches for reconstructions will require future testing using paleomagnetic studies. While there are ?2.7-2.8 Ga LIP-type greenstone belts in many crustal blocks, there are no precise matches with the 2.76-2.75 Ga Ghatgaon swarm of the Singhbhum craton. Howe
DS202004-0500
2020
Soderlund, U.Ba, M.H., Ibough, H., Lo, K., Youbi, N., Jaffal, M., Ernst, R.E., Niang, A.J., Dia, I., Abdeina, E.H., Bensalah, M.K., Boumehdi, M.A., Soderlund, U.Spatial and temporal distribution patterns of Precambrian mafic dyke swarms in northern Mauritania ( West African Craton): analysis and results fro remote sensing interpretation, geographical information systems ( GIS), Google Earth TM images, and regionaArabian Journal of Geosciences, Vol. 13, , 209 orchid.org/ 0000-002-3287-9537Africa, Mauritaniacraton

Abstract: We used remote sensing, geographical information systems, Google Earth™ images, and regional geology in order to (i) improve the mapping of linear structures and understand the chronology of different mafic dyke swarms in the Ahmeyim area that belongs to the Archean Tasiast-Tijirit Terrane of the Reguibat Shield, West African craton, NW Mauritania. The spatial and temporal distributions with the trends of the dyke swarms provide important information about geodynamics. The analysis of the mafic dyke swarms map and statistical data allow us to distinguish four mafic dyke swarm sets: a major swarm trending NE-SW to NNE-SSW (80%) and three minor swarms trending EW to ENE-WSW (9.33%), NW-SE to WNW-ESE (9.06%), and NS (1.3%). The major swarms extend over 35 km while the minor swarms do not exceed 13 km. The Google Earth™ images reveal relative ages through crossover relationships. The major NE-SW to NNE-SSW and the minor NS swarms are the oldest generations emplaced in the Ahemyim area. The NW-SE-oriented swarm dykes which are cutting the two former swarms are emplaced later. The minor E-W to WSW-ENE swarms are probably the youngest. A precise U-Pb baddeleyite age of 2733?±?2 Ma has been obtained for the NNE-SSW Ahmeyim Great Dyke. This dyke is approximately 1500 m wide in some zone and extends for more than 150 km. The distinct mafic dyke swarms being identified in this study can potentially be linked with coeval magmatic events on other cratons around the globe to identify reconstructed LIPs and constrain continental reconstructions.
DS1960-0748
1966
Soderstrom, L.Soderstrom, L.The Kimberlites of Avike Bay on the Bothnian Coast of SwedenGeol. Foren. Forhandl., Vol. 88, PP. 351-360.Sweden, ScandinaviaKimberlite, Alnoite, Petrology
DS200612-1332
2006
Sodoudi, F.Sodoudi, F., Yuan, X., Liu, Q., Chen, J.K.Lithospheric thickness beneath the Dabie Shan, central eastern Chin a from S receiver functions.Geophysical Journal International, Vol. 166, 3, pp. 1362-1367.ChinaGeophysics - seismics, UHP
DS201012-0220
2010
Sodoudi, F.Geissler, W.H., Sodoudi, F., Kind, R.Thickness of the central and eastern European lithosphere as soon by S receiver functions.Geophysical Journal International, Vol. 181, 2, pp. 604-634.EuropeGeophysics - seismic
DS201012-0330
2010
Sodoudi, F.Jones, A.G., Plomerova, J., Korja, T., Sodoudi, F., Spakman, W.Europe from the bottom up: a statistical examination of the central and northern European lithosphere asthenosphere boundary comparing seismological & EMLithos, in press available, 51p.EuropeGeophysics - seismics
DS201212-0790
2012
Sodoudi, F.Wolbern, I., Rumpker, G., Link, K., Sodoudi, F.Melt infiltration of the lower lithosphere beneath the Tanzania craton and the Albertine rift inferred from S receiver functions.Geochemical, Geophysics, Geosystems: G3, Vol. 10, in pressAfrica, TanzaniaTomography
DS201412-0864
2013
Sodoudi, F.Sodoudi, F., Yuan, X., Kind, R., Lebedev, S., Adam, J., et al.Seismic evidence for stratification in composition and anisotropic fabric within the thick lithosphere of Kalahari craton.Geochemistry, Geophysics, Geosystems: G3, Vol. 14, 12, pp. 5393-5412.Africa, South AfricaGeophysics - seismics
DS200812-1239
2007
Soe Moe, K.Wang, W., Hall, W.S., Soe Moe, K., Tower, J., Moses, T.M.Latest generation CVD grown synthetic diamonds from Appollo Diamond Inc.Gems & Gemology, Vol. 43, 4, Winter pp. 294-312.TechnologyOverview of CVD
DS201212-0762
2012
Soe Moe, K.Wang, W., D'Haenens-Johansson, U.F.S., Johnson, P., Soe Moe, K., Emerson, E., Newton, M., Moses, T.M.CVD synthetic diamodns from Gemesis Corp.Gems & Gemology, Vol. 48, 2, Summer pp. 80-97.TechnologyGemesis
DS201312-0954
2012
Soe Moe, K.Wang, W., D'Haenens-Johansson, U.F.S., Johnson, P., Soe Moe, K., Emerson, E., Newton, M.E., Moses, T.M.CVD synthetic diamonds from Gemesis Corp.Gems & Gemology, Vol. 48, , summer pp. 80-97.TechnologyGemesis
DS201412-0186
2014
Soe Moe, K.D'Haenens-Johansson, U.F.S., Soe Moe, K., Johnson, P., Yan Wong, S., Lu, R., Wang, W.Near-colorless HPHT synthetic diamonds from AOTC group.Gems & Gemology, Vol. 50, 1, Spring, pp. 30-45.TechnologySynthetic diamonds
DS2002-0682
2002
Soeding, E.Hay, W.W., Soeding, E., De Conto, R.M., Wold, C.N.The late Cenozoic uplift - climate change paradoxInternational Journal of Earth Sciences, Vol. 91, No. 5, Oct. pp. 746-74.GlobalGeomorphology - climate change
DS2000-0912
2000
Soedjatmiko, B.Soedjatmiko, B., Christensen, N.I.Seismic anisotropy under extended crust: evidence from upper mantle xenoliths, Cima Volcanic Field.Tectonophysics, Vol.321, No.3, June 15, pp. 279-96.CaliforniaGeophysics - seismics, Xenoliths - olivine
DS200812-1065
2008
Soemundsson, K.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
DS201608-1418
2016
Soesilo, J.Kueter, N., Soesilo, J., Fedortchouk, Y., Nestola, F., Belluco, L., Troch, J., Walle, M., Giuillong, M., Von Quadt, A., Driesner, T.Tracing the depositional history of Kalimantan diamonds by zircon provenance and diamond morphology studies. ( kimberlite or lamproite)Lithos, in press availableIndonesia, BorneoDeposit - Kalimantan

Abstract: Diamonds in alluvial deposits in Southeast Asia are not accompanied by indicator minerals suggesting primary kimberlite or lamproite sources. The Meratus Mountains in Southeast Borneo (Province Kalimantan Selatan, Indonesia) provide the largest known deposit of these so-called “headless” diamond deposits. Proposals for the origin of Kalimantan diamonds include the adjacent Meratus ophiolite complex, ultra-high pressure (UHP) metamorphic terranes, obducted subcontinental lithospheric mantle and undiscovered kimberlite-type sources. Here we report results from detailed sediment provenance analysis of diamond-bearing Quaternary river channel material and from representative outcrops of the oldest known formations within the Alino Group, including the diamond-bearing Campanian-Maastrichtian Manunggul Formation. Optical examination of surfaces of diamonds collected from artisanal miners in the Meratus area (247 stones) and in West Borneo (Sanggau Area, Province Kalimantan Barat;
DS201707-1342
2017
Soesilo, J.Kueter, N., Soesilo, J., Fedortchouk, Y., Nestola, F., Belluco, L., Troch, J., Walle, M., Guillong, M., Von Quadt, A., Driesner, T.Tracing the depositional history of Kalimantan diamonds by zircon proveneance and diamond morphology studies. Appendix 1 and 2Academia.edu, Supplementary material app. 1 and 2, both 10p.Asia, Kalimantandeposit - Kalimantan

Abstract: Diamonds in alluvial deposits in Southeast Asia are not accompanied by indicator minerals suggesting primary kimberlite or lamproite sources. The Meratus Mountains in Southeast Borneo (Province Kalimantan Selatan, Indonesia) provide the largest known deposit of these so-called “headless” diamond deposits. Proposals for the origin of Kalimantan diamonds include the adjacent Meratus ophiolite complex, ultra-high pressure (UHP) metamorphic terranes, obducted subcontinental lithospheric mantle and undiscovered kimberlite-type sources. Here we report results from detailed sediment provenance analysis of diamond-bearing Quaternary river channel material and from representative outcrops of the oldest known formations within the Alino Group, including the diamond-bearing Campanian–Maastrichtian Manunggul Formation. Optical examination of surfaces of diamonds collected from artisanal miners in the Meratus area (247 stones) and in West Borneo (Sanggau Area, Province Kalimantan Barat; 85 stones) points toward a classical kimberlite-type source for the majority of these diamonds. Some of the diamonds host mineral inclusions suitable for deep single-crystal X-ray diffraction investigation. We determined the depth of formation of two olivines, one coesite and one peridotitic garnet inclusion. Pressure of formation estimates for the peridotitic garnet at independently derived temperatures of 930–1250 °C are between 4.8 and 6.0 GPa. Sediment provenance analysis includes petrography coupled to analyses of detrital garnet and glaucophane. The compositions of these key minerals do not indicate kimberlite-derived material. By analyzing almost 1400 zircons for trace element concentrations with laser ablation ICP-MS (LA-ICP-MS) we tested the mineral's potential as an alternative kimberlite indicator. The screening ultimately resulted in a small subset of ten zircons with a kimberlitic affinity. Subsequent U–Pb dating resulting in Cretaceous ages plus a detailed chemical reflection make a kimberlitic origin unfavorable with respect to the regional geological history. Rather, trace elemental analyses (U, Th and Eu) suggest an eclogitic source for these zircons. The age distribution of detrital zircons allows in general a better understanding of collisional events that formed the Meratus orogen and identifies various North Australian Orogens as potential Pre-Mesozoic sediment sources. Our data support a model whereby the majority of Kalimantan diamonds were emplaced within the North Australian Craton by volcanic processes. Partly re-deposited into paleo-collectors or residing in their primary host, these diamond-deposits spread passively throughout Southeast Asia by terrane migration during the Gondwana breakup. Terrane amalgamation events largely metamorphosed these diamond-bearing lithologies while destroying the indicative mineral content. Orogenic uplift finally liberated their diamond-content into new, autochthonous placer deposits.
DS1997-1077
1997
Soesoo, A.Soesoo, A., Bons, P.D., Gray, D.R., Foster, D.A.Divergent double subduction: tectonics and petrologic consequencesGeology, Vol. 25, No. 8, August pp. 755-758.MantleTectonics, Subduction
DS1998-0389
1998
Soesoo, A.Elburg, M.A., Soesoo, A.Jurassic alkali rich magmatism in Victoria (Australia): its relation to Gondwana break up.Journal of African Earth Sciences, Vol. 27, 1A, p. 64. AbstractAustraliaGondwana, Alkaline magmatism
DS2001-0900
2001
Soffer, R.J.Peddle, D.R., White, H.P., Soffer, R.J., Miller, J.R.Reflectance processing of remote sensing spectroradiometer dataComp. and Geosciences, Vol. 27, No. 2, pp. 203-13.GlobalRemote sensing - reflectance, Program - BOREAS not specific to diamonds
DS201610-1867
2015
Sofianides, A.S.Harlow, G.E., Sofianides, A.S.Gems & Crystals from one of the World's great collections. American Museum of Natural HistoryAmerican Mineralogist, Vol. 101, p. 2132.GlobalBook review
DS201704-0619
2017
Sofonio, K.Baker, D.R., Sofonio, K.A metasomatic mechanism for the formation of Earth's earliest evolved crust.Earth and Planetary Science Letters, Vol. 463, pp. 48-55.MantleMetasomatism

Abstract: Following giant impacts the early Hadean Earth was shrouded in a steam atmosphere for durations on the order of 1 Ma. In order to investigate the potential of this atmosphere to fractionate major elements between various silicate reservoirs and influence a planet's geochemical evolution, we performed experiments simulating the interaction of a post-giant-impact steam atmosphere with a bulk silicate Earth (BSE) composition. Our experiments indicate that the composition of the solute in a water-rich atmosphere at 10 MPa and ?727?°C is remarkably similar to that of Earth's modern continental crust and would constitute up to 10% of the solution mass. This solute composition is similar to solute compositions previously measured at higher pressures, but distinct from those of near-solidus peridotite melts. Mass balance calculations based upon the hypothesis that Earth's initial water concentration was similar to that in CI carbonaceous chondrites, and that degassing and metasomatism produced the BSE, indicate that metasomatism could produce from 10 to 300% of the mass of the modern crust. If instead the amount of metasomatism is estimated by the difference between the water concentration in the BSE and in the depleted upper mantle, then a mass of up to approximately 4% of the current crust could be produced by metasomatism. Using results of earlier research we find that the solute is expected to have a smaller Sm/Nd ratio than the residual BSE, and if the solute was formed early in Earth's history its Nd isotopic signatures would be highly enriched. Although we cannot be certain that the metasomatic process created a significant fraction of Earth's crust in the early Hadean, our research indicates that it has the potential to form crustal nuclei and possibly was responsible for the production of incompatible-element enriched reservoirs in the early Earth, as seen in the isotopic signatures of Archean rocks.
DS201912-2826
2019
Sofonov, O.G.Sofonov, O.G., Butvina, V.G., Limanov, E.V., Kosova, S.A.Mineral indicators of reactions involving fluid salt components in the deep lithosphere. (eclogites and peridotites)Petrology, Vol. 27, pp. 489-515.MantleUHP, redox

Abstract: The salt components of aqueous and aqueous-carbonic fluids are very important agents of metasomatism and partial melting of crustal and mantle rocks. The paper presents examples and synthesized data on mineral associations in granulite- and amphibolite-facies rocks of various composition in the middle and lower crust and in upper-mantle eclogites and peridotites that provide evidence of reactions involving salt components of fluids. These data are analyzed together with results of model experiments that reproduce some of these associations and make it possible to more accurately determine their crystallization parameters.
DS200812-1208
2007
Sofroneev, S.V.Vasilev, E.A., Sofroneev, S.V.Zoning of diamonds from the Mir kimberlite pipe: results of Fourier transformed infrared spectroscopy.Geology of Ore Deposits, Vol. 49, 6, pp. 784-791.Russia, YakutiaDeposit - Mir
DS1950-0236
1955
SoguinexSoguinexRoche D'origine du Diamant En GuineeLa Chronique Des Mines Coloniales, 23RD. ANNEE, No. 228, JUNE, PP. 175-176.GlobalGenesis, Diamond
DS201801-0064
2017
SohSimon, 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.
DS1988-0650
1988
Sohn, I.Sohn, I.The debt crisis and minerals exporting developing countries: problems andprospectsNatural Resources forum, Vol. 12, No. 4, November pp. 383-392. Database # 17739Third GlobalEconomics, Macro-economics
DS200912-0710
2009
Sohn, I.Sohn, I.Minerals-supply security and mineral-use efficiency: some observations from the 1970-2005 interval.Minerals & Energy - Raw Materials Report, Vol. 23, no. 4, pp. 145- 161.GlobalEconomic modelling pitfalls
DS2003-0154
2003
Sohn, R.A.Braun, M.G., Sohn, R.A.Melt migration in plume ridge systemsEarth and Planetary Science Letters, Vol. 213, 3-4, pp. 417-30.GlobalTectonics - not specific to diamonds
DS200412-0202
2003
Sohn, R.A.Braun, M.G., Sohn, R.A.Melt migration in plume ridge systems.Earth and Planetary Science Letters, Vol. 213, 3-4, pp. 417-30.GlobalTectonics - not specific to diamonds
DS1930-0264
1937
Sohnge, P.G.Sohnge, P.G.The Geology and archeology of the Vaal River BasinGeological Survey of South Africa MEMOIR., No. 35South AfricaVaal River Diggings
DS1950-0465
1959
Sohnge, P.G.Devilliers, J.DE, Sohnge, P.G.The Geology of the RichtersveldGeological Survey of South Africa, MEMOIR No. 48, 295P.South AfricaAlexander Bay, Geology, Kimberley
DS1960-0401
1963
Sohnge, P.G.Sohnge, P.G.Genetic Problems of Pipe Deposits in South AfricaGeological Society of South Africa Proceedings, Vol. 66, PP. 19-77.South AfricaGenesis
DS1989-1427
1989
Soifer, B.T.Soifer, B.T., Beichman, C.A., Sanders, D.B.An infrared view of the universe #1American Scientist, Vol. 77, No. 1, January-February pp. 46-53. Database #GlobalGeophysics, Remote sensing -IRAS
DS201212-0470
2012
Sojem, J.Michael, L., Sojem, J., Robin, P.The geology and geochemistry of the Wadagera kimberlite and the characteristics of the underlying subcontinental lithospheric mantle, Dharwar Craton, India10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractIndiaDeposit - Wadagera
DS201507-0325
2015
Sokharev, V.A.Mikhailova, J.A., Kalashnikov, A.O., Sokharev, V.A., Pakhomovsky, Y.A., Konopleva, N.G., Yakovenchuk, V.N., Bazai, A.V., Goryainov, P.M., Ivanyuk, G.Yu.3D mineralogical mapping of the Kovdor phoscorite-carbonatite complex, Russia.Mineralium Deposita, In press available. 19p.RussiaCarbonatite
DS201511-1849
2016
Sokharev, V.A.Kalashnikov, A.O., Yakovenchuk, V.N., Pakhomovsky, Y.A.A., Bazai, A.V., Sokharev, V.A., Konopleva, N.G., Mikhailova, J.A., Goryainov, P.M., Ivanyuk, G.Yu.Scandium of the Kovdor baddeleyite apatite magnetite deposit ( Murmansk region, Russia): mineralogy, spatial distribution, and potential source.Ore Geology Reviews, Vol. 72, pp. 532-537.RussiaCarbonatite
DS201602-0226
2016
Sokharev, V.A.Mikhailova, J.A., Kalashnikov, A.O., Sokharev, V.A., Pakhomovsky, Y.A., Konopleva, N.G., Yakovenchuk, V.N., Bazai, A.V., Goryainov, P.M., Ivanyuk, G.Y.3D mineralogical mapping of the Kovdor phoscorite carbonatite complex ( Russia).Mineralium Deposita, Vol. 51, 1, pp. 131-149.RussiaDeposit - Kovdor

Abstract: The Kovdor baddeleyite-apatite-magnetite deposit in the Kovdor phoscorite-carbonatite pipe is situated in the western part of the zoned alkali-ultrabasic Kovdor intrusion (NW part of the Fennoscandinavian shield; Murmansk Region, Russia). We describe major intrusive and metasomatic rocks of the pipe and its surroundings using a new classification of phoscorite-carbonatite series rocks, consistent with the IUGS recommendation. The gradual zonation of the pipe corresponds to the sequence of mineral crystallization (forsterite-hydroxylapatite-magnetite-calcite). Crystal morphology, grain size, characteristic inclusions, and composition of the rock-forming and accessory minerals display the same spatial zonation pattern, as do the three minerals of economic interest, i.e. magnetite, hydroxylapatite, and baddeleyite. The content of Sr, rare earth elements (REEs), and Ba in hydroxylapatite tends to increase gradually at the expense of Si, Fe, and Mg from early apatite-forsterite phoscorite (margins of the pipe) through carbonate-free, magnetite-rich phoscorite to carbonate-rich phoscorite and phoscorite-related carbonatite (inner part). Magnetite displays a trend of increasing V and Ca and decreasing Ti, Mn, Si, Cr, Sc, and Zn from the margins to the central part of the pipe; its grain size initially increases from the wall rocks to the inner part and then decreases towards the central part; characteristic inclusions in magnetite are geikielite within the marginal zone of the phoscorite-carbonatite pipe, spinel within the intermediate zone, and ilmenite within the inner zone. The zoning pattern seems to have formed due to both cooling and rapid degassing (pressure drop) of a fluid-rich magmatic column and subsequent pneumatolytic and hydrothermal processes.
DS201604-0611
2016
Sokharev, V.A.Ivanyuk, G.Yu., Kalashnikov, A.O., Pakhomovsky, Ya.A., Mikhailov, J.A., Yakovenchuk, V.N., Konopleva, N.G., Sokharev, V.A., Bazai, A.V., Goryainov, P.M.Economic minerals of the Kovdor baddeleyite apatite magnetite deposit, Russia: mineralogy, spatial distribution and ore processing optimization.Ore Geology Reviews, in press available 73p.RussiaDeposit - Kovdor

Abstract: The comprehensive petrographical, petrochemical and mineralogical study of the Kovdor magnetite-apatite-baddeleyite deposit in the phoscorite-carbonatite complex (Murmansk Region, Russia) revealed a spatial distribution of grain size and chemical composition of three economically extractable minerals — magnetite, apatite, and baddeleyite, showing that zonal distribution of mineral properties mimics both concentric and vertical zonation of the carbonatite-phoscorite pipe. The marginal zone of the pipe consists of (apatite)-forsterite phoscorite carrying fine grains of Ti-Mn-Si-rich magnetite with ilmenite exsolution lamellae, fine grains of Fe-Mg-rich apatite and finest grains of baddeleyite, enriched in Mg, Fe, Si and Mn. The intermediate zone accommodates carbonate-free magnetite-rich phoscorites that carry medium to coarse grains of Mg-Al-rich magnetite with exsolution inclusions of spinel, medium-grained pure apatite and baddeleyite. The axial zone hosts carbonate-rich phoscorites and phoscorite-related carbonatites bearing medium-grained Ti-V-Ca-rich magnetite with exsolution inclusions of geikielite-ilmenite, fine grains of Ba-Sr-Ln-rich apatite and comparatively large grains of baddeleyite, enriched in Hf, Ta, Nb and Sc. The collected data enable us to predict such important mineralogical characteristics of the multicomponent ore as chemical composition and grain size of economic and associated minerals, presence of contaminating inclusions, etc. We have identified potential areas of maximum concentration of such by-products as scandium, niobium and hafnium in baddeleyite and REEs in apatite.
DS201605-0847
2016
Sokharev, V.A.Ivanyuk, G.Yu., Kalashnikov, A.O., Pakhomovsky, Ya.A., Mikhailova, J.A., Yakovenchuk, V.N., Konopleva, N.G., Sokharev, V.A., Bazai, A.V., Goryainov, P.M.Economic minerals of the Kovdor baddeleyite apatite magnetite deposit, Russia: mineralogy, spatial distribution and ore procesing optimization.Ore Geology Reviews, Vol. 77, pp. 279-311.RussiaCarbonatite, Kovdor

Abstract: The comprehensive petrographical, petrochemical and mineralogical study of the Kovdor magnetite-apatite-baddeleyite deposit in the phoscorite-carbonatite complex (Murmansk Region, Russia) revealed a spatial distribution of grain size and chemical composition of three economically extractable minerals — magnetite, apatite, and baddeleyite, showing that zonal distribution of mineral properties mimics both concentric and vertical zonation of the carbonatite-phoscorite pipe. The marginal zone of the pipe consists of (apatite)-forsterite phoscorite carrying fine grains of Ti-Mn-Si-rich magnetite with ilmenite exsolution lamellae, fine grains of Fe-Mg-rich apatite and finest grains of baddeleyite, enriched in Mg, Fe, Si and Mn. The intermediate zone accommodates carbonate-free magnetite-rich phoscorites that carry medium to coarse grains of Mg-Al-rich magnetite with exsolution inclusions of spinel, medium-grained pure apatite and baddeleyite. The axial zone hosts carbonate-rich phoscorites and phoscorite-related carbonatites bearing medium-grained Ti-V-Ca-rich magnetite with exsolution inclusions of geikielite-ilmenite, fine grains of Ba-Sr-Ln-rich apatite and comparatively large grains of baddeleyite, enriched in Hf, Ta, Nb and Sc. The collected data enable us to predict such important mineralogical characteristics of the multicomponent ore as chemical composition and grain size of economic and associated minerals, presence of contaminating inclusions, etc. We have identified potential areas of maximum concentration of such by-products as scandium, niobium and hafnium in baddeleyite and REEs in apatite.
DS201608-1413
2016
Sokharev, V.A.Ivanyuk, G.Yu., Kalashnikov, A.O., Pakhomovsky, Ya.A., Mikhailova, J.A., Yakovenchuk, V.N., Konopleva, N.G., Sokharev, V.A., Bazai, A.V., Goryainov, P.M.Economic minerals of the Kovdor baddeleyite apatite magnetite deposit, Russia: mineralogy, spatial distribution and ore processing optimization.Ore Geology Reviews, Vol. 77, pp. 279-311.RussiaDeposit - Kovdor

Abstract: The comprehensive petrographical, petrochemical and mineralogical study of the Kovdor magnetite-apatite-baddeleyite deposit in the phoscorite-carbonatite complex (Murmansk Region, Russia) revealed a spatial distribution of grain size and chemical composition of three economically extractable minerals — magnetite, apatite, and baddeleyite, showing that zonal distribution of mineral properties mimics both concentric and vertical zonation of the carbonatite-phoscorite pipe.The marginal zone of the pipe consists of (apatite)-forsterite phoscorite carrying fine grains of Ti-Mn-Si-rich magnetite with ilmenite exsolution lamellae, fine grains of Fe-Mg-rich apatite and finest grains of baddeleyite, enriched in Mg, Fe, Si and Mn. The intermediate zone accommodates carbonate-free magnetite-rich phoscorites that carry medium to coarse grains of Mg-Al-rich magnetite with exsolution inclusions of spinel, medium-grained pure apatite and baddeleyite. The axial zone hosts carbonate-rich phoscorites and phoscorite-related carbonatites bearing medium-grained Ti-V-Ca-rich magnetite with exsolution inclusions of geikielite-ilmenite, fine grains of Ba-Sr-Ln-rich apatite and comparatively large grains of baddeleyite, enriched in Hf, Ta, Nb and Sc. The collected data enable us to predict such important mineralogical characteristics of the multicomponent ore as chemical composition and grain size of economic and associated minerals, presence of contaminating inclusions, etc. We have identified potential areas of maximum concentration of such by-products as scandium, niobium and hafnium in baddeleyite and REEs in apatite.
DS201705-0824
2017
Sokhonchuk, T.Dobrzhinetskaya,L.F., Mukhin, P., Wang, Q., Sokhonchuk, T.Moissanite ( SiC) with metal-silicide and silicon inclusions from tuff of Israel: Raman spectroscopy and electron microscopy studies.Lithos, Vol. 282, pp. 1-11.Asia, IsraelMoissanite

Abstract: Here, we present studies of natural SiC that occurs in situ in tuff related to the Miocene alkaline basalt formation deposited in northern part of Israel. Raman spectroscopy, SEM and FIB-assisted TEM studies revealed that SiC is primarily hexagonal polytypes 4H-SiC and 6H-SiC, and that the 4H-SiC polytype is the predominant phase. Both SiC polytypes contain crystalline inclusions of silicon (Sio) and inclusions of metal-silicide with varying compositions (e.g. Si58V25Ti12Cr3Fe2, Si41Fe24Ti20Ni7V5Zr3, and Si43Fe40Ni17). The silicides crystal structure parameters match Si2TiV5 (Pm-3 m space group, cubic), FeSi2Ti (Pbam space group, orthorhombic), and FeSi2 (Cmca space group, orthorhombic) respectively. We hypothesize that SiC was formed in a local ultra-reduced environment at respectively shallow depths (60-100 km), through a “desilification” reaction of SiO2 with highly reducing fluids (H2O-CH4-H2-C2H6) arisen from the mantle “hot spot” and passing through alkaline basalt magma reservoir. SiO2 (melt) interacting with the fluids may originate from the walls of the crustal rocks surrounding this magmatic reservoir. The “desilification” process led to the formation of SiC and the reduction of metal-oxides to native metals, alloys, and silicides. The latter were trapped by SiC during its growth. Hence, interplate “hot spot” alkali basalt volcanism can now be included as a geological environment where SiC, silicon, and silicides can be found.
DS201805-0943
2018
Sokhonchuk, T.Dobrzhinetskaya, L., Mukhin, P., wang, Q., Wirth, R., O'Bannon, E., Zhao, W., Eppelbaum, L., Sokhonchuk, T.Moissanite ( SiC) with metal silicide and silicon inclusions from tuff of Israel: raman spectroscopy and electron microscope studies.Lithos, in press available 58p.Europe, Israelmoissanite

Abstract: Here, we present studies of natural SiC that occurs in situ in tuff related to the Miocene alkaline basalt formation deposited in northern part of Israel. Raman spectroscopy, SEM and FIB-assisted TEM studies revealed that SiC is primarily hexagonal polytypes 4H-SiC and 6H-SiC, and that the 4H-SiC polytype is the predominant phase. Both SiC polytypes contain crystalline inclusions of silicon (Sio) and inclusions of metal-silicide with varying compositions (e.g. Si58V25Ti12Cr3Fe2, Si41Fe24Ti20Ni7V5Zr3, and Si43Fe40Ni17). The silicides crystal structure parameters match Si2TiV5 (Pm-3 m space group, cubic), FeSi2Ti (Pbam space group, orthorhombic), and FeSi2 (Cmca space group, orthorhombic) respectively. We hypothesize that SiC was formed in a local ultra-reduced environment at respectively shallow depths (60-100 km), through a "desilification" reaction of SiO2 with highly reducing fluids (H2O-CH4-H2-C2H6) arisen from the mantle "hot spot" and passing through alkaline basalt magma reservoir. SiO2 (melt) interacting with the fluids may originate from the walls of the crustal rocks surrounding this magmatic reservoir. The "desilification" process led to the formation of SiC and the reduction of metal-oxides to native metals, alloys, and silicides. The latter were trapped by SiC during its growth. Hence, interplate "hot spot" alkali basalt volcanism can now be included as a geological environment where SiC, silicon, and silicides can be found.
DS2001-1099
2001
Sokjolov, S.V.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
DS1995-1421
1995
SokolPalyanov, Yu.N., Khokhyakov, A.F., Borzdov, Yu.M., SokolDiamond morphology in growth and dissolution processesProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 415-417.GlobalDiamond morphology, Diamond growth
DS1997-0881
1997
SokolPalyanov, Y.N., Borzdov, Sokol, Khokhryakov, Gusev ..Dislocation free monocrystals of sythetic diamondDoklady Academy of Sciences, Vol. 353, No. 2, Feb-Mar, pp. 243-6.GlobalDiamond - synthetics, crystallography
DS1998-1108
1998
SokolPalyanov, Y.N., Gusev, V.A., Kupriyanov, Borzdov, SokolThe effect of growth rate on formation of nitrogenous defects in diamond7th. Kimberlite Conference abstract, pp. 649-51.RussiaDiamond inclusions, Mineralogy
DS2000-0101
2000
SokolBorzdov, Y.M., Sokol, Palyanov, Khokhryakov, SobolevGrowth of synthetic diamond monocrystals weighing up to six carats and perspectives of their application.Doklady Academy of Sciences, Vol. 374, No. 7, Sept-Oct. pp. 1113-5.RussiaDiamond - morphology, Diamond - synthesis, Crystallography
DS201512-1960
2015
Sokol, A.Reutsky, V., Borzdov, Y., Palyanov, Y., Sokol, A., Izokh, O.Carbon isotope fractionation during experimental crystallization of diamond from carbonate fluid at mantle conditions.Contributions to Mineralogy and Petrology, Vol. 170, pp. 41-MantleHPHT

Abstract: We report first results of a systematic study of carbon isotope fractionation in a carbonate fluid system under mantle PT conditions. The system models a diamond-forming alkaline carbonate fluid using pure sodium oxalate (Na2C2O4) as the starting material, which decomposes to carbonate, CO2 and elementary carbon (graphite and diamond) involving a single source of carbon following the reaction 2Na2C2O4 ? 2Na2CO3 + CO2 + C. Near-liquidus behaviour of carbonate was observed at 1300 °C and 6.3 GPa. The experimentally determined isotope fractionation between the components of the system in the temperature range from 1300 to 1700 °C at 6.3 and 7.5 GPa fit the theoretical expectations well. Carbon isotope fractionation associated with diamond crystallisation from the carbonate fluid at 7.5 GPa decreases with an increase in temperature from 2.7 to 1.6 ‰. This trend corresponds to the function ?Carbonate fluid-Diamond = 7.38 × 106 T?2.
DS202205-0697
2022
Sokol, A.Kruk, A., Sokol, A.Role of volatiles in the evolution of a carbonatitic melt in peridotitic mantle: experimental constraints at 6.3 Gpa and 1200-1450C. Minerals ( MDPI), Vol. 12, 466 20p. PdfMantlecarbonatite

Abstract: Reconstruction of the mechanisms of carbonatitic melt evolution is extremely important for understanding metasomatic processes at the base of the continental lithospheric mantle (CLM). We have studied the interaction between garnet lherzolite and a carbonatitic melt rich in molecular CO2 and H2O in experiments at 6.3 GPa and 1200-1450 °C. The interaction with garnet lherzolite and H2O-bearing carbonatite melt leads to wehrlitization of lherzolite, without its carbonation. Introduction of molecular CO2 and H2O initiates carbonation of olivine and clinopyroxene with the formation of orthopyroxene and magnesite. Partial carbonation leads to the formation of carbonate-silicate melts that are multiphase saturated with garnet harzburgite. Upon complete carbonation of olivine already at 1200 °C, melts with 27-31 wt% SiO2 and MgO/CaO ? 1 are formed. At 1350-1450 °C, the interaction leads to an increase in the melt fraction and the MgO/CaO ratio to 2-4 and a decrease in the SiO2 concentration. Thus, at conditions of a thermally undisturbed CLM base, molecular CO2 and H2O dissolved in metasomatic agents, due to local carbonation of peridotite, can provide the evolution of agent composition from carbonatitic to hydrous silicic, i.e., similar to the trends reconstructed for diamond-forming high density fluids (HDFs) and genetically related proto-kimberlite melts.
DS2002-1205
2002
Sokol, A.C.Palyanov, Y.N., Sokol, A.C., Borzdov, V.M.Diamond formation through carbonate silicate interactionAmerican Mineralogist, Vol.87,7, pp. 1009-13.GlobalDiamond - genesis, morphology
DS1992-0450
1992
Sokol, A.G.Fedorov, I.I., Chepurov, A.I., Osorgin, N. Yu., Sokol, A.G.Modeling of component composition of graphite and diamond equilibrated C-O-H fluid at high temperatures and pressuresRussian Geology and Geophysics, Vol. 33, No. 4, pp. 61-68RussiaDiamond morphology, Experimental petrology
DS1993-0433
1993
Sokol, A.G.Fedorov, I.I., Chepurov, A.I., Osorgin, N.Yu., Sokol, A.G., Sobolev, V.Experimental modeling and thermodydnamic analysis of C-O-H fluid in equilibrium with graphite and diamond at high pressures and temperatures.Doklady Academy of Sciences USSR, Earth Science Section, Vol. 321, No. 8, August 1993, pp. 163-166.Russia, Commonwealth of Independent States (CIS)Geothermometry, Graphite/diamond interface
DS1997-0883
1997
Sokol, A.G.Palyanov, Y.N., Sokol, A.G., Borzdov, et al.Synthesis and characterization of diamond single crystals up to 4 caratsDoklady Academy of Sciences, Vol. 355A, No. 6, July-Aug. pp. 856-61.RussiaDiamond morphology, Diamond synthesis
DS1998-1109
1998
Sokol, A.G.Palynaov, Yu.N., Sokol, A.G., Borzdov, Y.M., et al.Diamond crystallization in the systems CaCO3-C, MgCO3-C, CaMg (CO3)-CDoklady Academy of Sciences, Vol. 363, No. 8, Oct-Nov. pp. 1156-60.GlobalDiamond mineralogy - experimental, Diamond morphology
DS1998-1377
1998
Sokol, A.G.Sokol, A.G., Palynanov, Y.N., Borzdov et al.Diamond crystallization in a Na2 CO3 meltDoklady Academy of Sciences, Vol. 361a, No. 6, pp. 821-4.MantleDiamond morphology, Petrology
DS2000-0772
2000
Sokol, A.G.Polyanov, Yu.N., Sokol, A.G., Khokhryakov et al.Diamond and graphite crystallization in COH fluid at Pt parameters of the natural diamond formation. #1Doklady Academy of Sciences, Vol. 375A, No. 9, pp. 1395-8.GlobalDiamond - morphology
DS2000-0913
2000
Sokol, A.G.Sokol, A.G., Tomilenko, A.A., Palyanov, Borzdov, et al.Fluid regime of diamond crystallization in carbonate carbon systemsEuropean Journal of Mineralogy, Vol. 12, pp. 367-75.GlobalDiamond - morphology, crystal, Petrology - experimental
DS2001-0880
2001
Sokol, A.G.Palyanov, Y.N., Shatsky, V.S., Sokol, A.G., TomilenkoCrystallization of metamorphic diamond: an experimental modelingDoklady, Vol. 381, No. 8, pp. 935-8.GlobalDiamond - morphology, Metamorphism
DS2001-0881
2001
Sokol, A.G.Palyanov, Y.N., Sokol, A.G., Khokhryakov, PalyanovaDiamond and graphite crystallization in COH fluid at PT parameters of the natural diamond formation. #2Doklady Academy of Sciences, Vol. 375A, No. 9, Nov.Dec. pp.1395-98.GlobalDiamond - genesis
DS2001-1100
2001
Sokol, A.G.Sokol, A.G., Borzdov, Y.M., Palynov, Y.M.An experimental demonstrator of diamond formation in the dolomite carbon and dolomite fluid carbon systems.Eur. Jour. Min., Vol. 13, No. 5, pp. 893-900.RussiaCarbonatite, Petrology - experimental
DS2002-1204
2002
Sokol, A.G.Palyanov, N., Sokol, A.G., Borzdov, M., Khokhryakov, A.Fluid bearing alkaline carbonate melts as the medium for the formation of diamonds in Earth's mantle:Lithos, Vol. 60, No. 3-4, Feb. pp. 145-59.MantlePetrology - experimental study
DS2002-1206
2002
Sokol, A.G.Palyanov, Y.N., Sokol, A.G., Borzdov, KhokhryakovFluid bearing alkaline carbonate melts as the medium for the formation of diamonds in Earth's mantle:Lithos, Vol.60, pp. 145-59.MantleDiamond - crystallization, melting, UHP, Petrology - experimental
DS2002-1207
2002
Sokol, A.G.Palyanov, Y.N., Sokol, A.G., Borzdov, Y.M., Khokhryakov, A.F., Sobolev, N.V.Diamond formation through carbonate silicate interactionAmerican Mineralogist, Vol. 87, pp. 1009-13.GlobalDiamond - crystallography, genesis, carbon, magnesite, Petrology - experimental
DS2002-1453
2002
Sokol, A.G.Shatsky, A.F., Borzdov, Yu.M., Sokol, A.G., Palyanov, Y.N.Phase formation and diamond crystallization in carbon bearing ultrapotassic carbonate silicate systems.Russian Geology and Geophysics, Vol. 43, 10, pp. 889-901.GlobalDiamond - morphology
DS2002-1521
2002
Sokol, A.G.Sokol, A.G., Palyanov, Y.N.Crystallization of diamond and graphite in C O H fluid under mantle P T parameters18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.79. (poster)MantleUHP mineralogy - crystallography
DS200412-1494
2004
Sokol, A.G.Palyanov, Yu.N.,Sokol, A.G., Tomilenko, A.A., Sobolev, N.V.Conditions of diamond formation under carbonate silicate interaction.Lithos, ABSTRACTS only, Vol. 73, p. S83. abstractTechnologyDiamond nucleation
DS200412-1872
2004
Sokol, A.G.Sokol, A.G., Palyanov, Yu.N.Diamond formation in MgO SiO2 H2O C system at 7.5 GPa and 1600 C.Lithos, ABSTRACTS only, Vol. 73, p. S104. abstractTechnologyDiamond nucleation
DS200512-0817
2005
Sokol, A.G.Palyanov, Y.N., Sokol, A.G., Tomilenko, A.A., Sobolev, N.V.Conditions of diamond formation through carbonate silicate interaction.European Journal of Mineralogy, Vol. 17, 2, pp. 207-214.Diamond genesis
DS200512-1021
2004
Sokol, A.G.Sokol, A.G., Palyanov, Yu.N.Diamond crystallization in fluid and carbonate fluid systems under mantle P T conditions: 2. an analytical review of experimental data.Geochemistry International, Vol. 42, 11, pp. 1018-1032.MantleExperimental petrology
DS200512-1022
2004
Sokol, A.G.Sokol, A.G., Palynaov, Y.N., Palyanova, G.A., Tomilenko, A.A.Diamond crystallization in fluid and carbonate fluid systems under mantle P-T conditions: 1. fluid composition.Geochemistry International, Vol. 42, 9, pp. 830-838.MantleGeochemistry - diamond crystallography
DS200612-1023
2005
Sokol, A.G.Palynaov, Y.N., Sokol, A.G., Sobolev, N.V.Experimental modeling of mantle diamond forming processes.Russian Geology and Geophysics, Vol. 46, 12, pp. 1271-1284.MantleDiamond genesis
DS200612-1271
2005
Sokol, A.G.Shatsky, V.S., Palyanov, Y.N., Sokol, A.G., Tomilenko, A.A., Sobolev, N.V.Diamond formation in UHP dolomite marbles and garnet pyroxene rocks of the Kokchetav Massif, northern Kazakstan: natural and experimental evidence.International Geology Review, Vol. 47, 10, pp. 999-1010.RussiaUHP
DS200712-0796
2007
Sokol, A.G.Palyanov, Y.N., Borzdov, Y.M., Batleva, Y.V., Sokol, A.G., Palyanova, G.A.Reducing role of sulfides and diamond formation in the Earth's mantle.Earth and Planetary Science Letters, Vol. 260, 1-2, pp. 242-256.MantleDiamond genesis
DS200712-0797
2007
Sokol, A.G.Palyanov, Y.N., Borzdov, Yu.M., Bataleva, Yu.V., Sokol, A.G., Palyanova, G.A., Kupriyanov, I.N.Reducing role of sufides and diamond formation in the Earth's mantle.Earth and Planetary Science Letters, Vol. 260, 1-2, pp. 242-256.MantleDiamond genesis
DS200712-0798
2007
Sokol, A.G.Palyanov, Y.N., Borzdov, Yu.M., Bataleva, Yu.V., Sokol, A.G., Palyanova, G.A., Kupriyanov, I.N.Reducing role of sufides and diamond formation in the Earth's mantle.Earth and Planetary Science Letters, Vol. 260, 1-2, pp. 242-256.MantleDiamond genesis
DS200712-0799
2007
Sokol, A.G.Palynaov, Y.N., Shatsky, V.S., Sobolev, N.V., Sokol, A.G.The role of mantle uptrapotassic fluids in diamond formation.Proceedings of National Academy of Sciences USA, Vol. 104, 22, pp. 9122-9127. IngentaMantleDiamond genesis
DS200712-1011
2008
Sokol, A.G.Sokol, A.G., Palyanov, Yu.N.Diamond formation in the system MgO Si02 H20C at 7.5 GPa and 1,600 C.Contributions to Mineralogy and Petrology, Vol. 155, 1, pp. 33-43.TechnologyDiamond genesis - petrology
DS200812-0617
2008
Sokol, A.G.Kupriyanov, I.N., Paynamov, Yu.N., Kalinin, A.A., Sokol, A.G., Khokhryakov, A.F., Gusev, V.A.The effect of HPHT treatment on the spectroscopic features of type IIb synthetic diamonds.Diamond and Related Materials, Vol. 17, 7-10, pp. 1203-1206.TechnologyType IIb synthetics
DS200912-0374
2009
Sokol, A.G.Khokhryakov, A.F., Nechaev, D.V., Sokol, A.G., Palyanov, Y.N.Formation of various types of graphite inclusions in diamond: experimental data.Lithos, In press availableTechnologyDiamond inclusions
DS200912-0562
2009
Sokol, A.G.Palyanov, Y.N., Sokol, A.G.The effect of composition of mantle fluids/melts on diamond formation processes.Lithos, in press availableMantleChemistry
DS200912-0711
2009
Sokol, A.G.Sokol, A.G., Palyanova, G.A., Palyanov, Y.N., Tomilenko, A.A., Melenevsky, V.N.Fluid regime and diamond formation in the reduced mantle: experimental constraints.Geochimica et Cosmochimica Acta, Vol. 73, 19, pp. 5820-5834.MantleDiamond genesis, crystallography
DS201012-0561
2010
Sokol, A.G.Palyanov, Y.N., Borzdov, Y.M., Khokhryakov, A.F.,Kupriyanov, I.N., Sokol, A.G.Effect of nitrogen impurity on diamond crystal growth processes.Crystal Growth & Design, Vol. 10, 6, pp. 3169-3175.TechnologyDiamond morphology
DS201012-0562
2009
Sokol, A.G.Palyanov, Y.N., Kupriyanov, I.N., Borzdov, Y.M., Sokol, A.G., Khokhryakov, A.F.Diamond crystallization from a sulfur - carbon system at HPHT conditions.Crystal Growth & Design, Vol. 9, 6, pp. 2922-2926.TechnologyDiamond synthesis
DS201212-0061
2012
Sokol, A.G.Bataleva, Yu.V., Palyanov, Yu.N., Sokol, A.G., Borzdov, Yu.M., Sobolev, N.V.Conditions of formation of Cr-pyrope and escolaite during mantle metasomatism: experimental modeling.Doklady Earth Sciences, Vol. 442, 1, pp. 76-80.TechnologyMetasomatism
DS201212-0684
2012
Sokol, A.G.Sokol, A.G., Kupriyanov, I., Palyanov, Yu., Kruk, A.Water activity in kimberlite magmas: constrains from melting experiments at 6.3 Gpa.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussiaDeposit - Udachnaya
DS201212-0685
2013
Sokol, A.G.Sokol, A.G., Kupriyanov, I.N., Palyanov, Y.N., Kruk, A.N., Sobolev, N.V.Melting experiments on the Udachnaya kimberlite at 6.3-7.5 Gpa: implications for the role of H2O in magma generation and formation of hydrous olivine.Geochimica et Cosmochimica Acta, Vol. 101, pp. 133-155.RussiaDeposit - Udachnaya
DS201212-0686
2012
Sokol, A.G.Sokol, A.G., Kupriyanov, I.N., Palyanov, Yu.N., Kruk, A.N., Sobolev, N.V.Melting experiments on the Udachnaya kimberlite at 6.3-7.5 Gpa: implications for the role of H2O in magma generation and formation of hydrous olivine.emc2012 @ uni-frankfurt.de, 1p. AbstractRussiaDeposit - Udachnaya
DS201312-0863
2013
Sokol, A.G.Sokol, A.G., Kupriyanov, I.N., Palyanov, Y.N.Partitioning of H2O between olivine and carbonate-silicate melts at 6.30 Gpa and 1400C: implications for kimberlite formation.Earth and Planetary Science Letters, Vol. 383, pp. 58-67.MantleKimberlite genesis
DS201312-0864
2013
Sokol, A.G.Sokol,A.G.,Kupriyanov, I.N., Palyanov, Y.N., Kruk, A.N., Sobolev, N.V.Melting experiments in the Udachnaya kimberlite at 6.3-7.5 Gpa: implications for the role of H2O in magma generation and formation of hydrous olivine.Geochimica et Cosmochimica Acta, Vol. 101, Jn. 15, pp. 133-155.RussiaDeposit - Udachnaya
DS201412-0658
2014
Sokol, A.G.Palyanov, Y.N., Bataleva, Y.V., Sokol, A.G., Borzdov, Y.M., Kupriyanov, I.N., Reutsky, V.N., Sobolev, N.V.Mantle slab interaction and redox mechanism of diamond formation.Proceedings of National Academy of Science USA, Vol. 110, 51, Dec. 17, pp.MantleUHP, deep carbon cycle
DS201502-0089
2015
Sokol, A.G.Palyanov, Y.U., Sokol, A.G., Khokhryakov, A.F., Kruk, A.N.Conditions of diamond crystallization in kimberlite melt: experimental data.Russian Geology and Geophysics, Vol. 56, 1-2, pp. 196-210.TechnologyDiamond morphology
DS201502-0092
2015
Sokol, A.G.Reutsky, V.N., Palyanov, Yu.N., Borzdov, Yu.M., Sokol, A.G.Isotope fractionation of carbon during diamond cystallization in model systems.Russian Geology and Geophysics, Vol. 56, 1-2, pp. 239-244.TechnologyDiamond morphology
DS201502-0105
2015
Sokol, A.G.Sokol, A.G., Kruk, A.N.Conditions of kimberlite magma generation: experimental constraints.Russian Geology and Geophysics, Vol. 56, 1, pp. 245-259.MantleKimberlite genesis
DS201507-0331
2015
Sokol, A.G.Persikov, E.S., Bukhtiyarov, P.G., Sokol, A.G.Change in the viscosity of kimberlite and basaltic magmas during their origin and evolution ( prediction).Russian Geology and Geophysics, Vol. 56, pp. 885-892.Canada, Northwest Territories, RussiaDeposit - Jericho, Udachnaya
DS201509-0428
2015
Sokol, A.G.Sokol, A.G., Kruk, A.N., Chebotarev, D.A., Palyanov, Yu.N., Sobolev, N.V.The composition of garnet as an indicator of the conditions of peridotite-carbonatite interaction in the subcratonic lithosphere ( Experimental data).Doklady Earth Sciences, Vol. 463, 1, pp. 746-750.MantleGarnet, carbonatite

Abstract: The article focuses on the study of composition of garnets of the lherzolitic and harzburgitic parageneses and the conditions of peridotite. As per the study, reconstruction of the conditions of metasomatism of peridotitic sources of kimberlite is possible in the evolution of garnet. It mentions the importance of dry and hydrous carbonatitic melt upon alteration of peridotitic sources of kimberlite as it acted as an another heat source.
DS201510-1806
2015
Sokol, A.G.Sokol, A.G., Khokhryakov, A.F., Palyanov, Yu.N.Composition of primary kimberlite magma: constraints from melting and diamond dissolution experiments.Contributions to Mineralogy and Petrology, Vol. 170, 19p.RussiaDeposit - Udachnaya

Abstract: Experiments are applied to constrain the composition of primary kimberlitic magmas which were in equilibrium with lithospheric peridotite and could resorb the entrained diamond to form typical dissolution features. The experiments are run on samples of a model carbonatite and a melt of the Udachnaya kimberlite at 6.3 GPa and 1400 °C, and at unbuffered or Re-ReO2-buffered oxygen fugacity (1-2 log units above Ni-O). Near-liquidus dry Fe3+-free carbonatitic melt (derived from carbonated harzburgite) is saturated with the Ol-Grt-Opx-Mgs assemblage and is almost inert to diamond. Carbonatitic melts that bear 4.6-6.8 wt% Fe2O3 or 1.5 wt% H2O are in equilibrium only with Mgs ± Ol near the liquidus. Dissolution of diamond by these melts produces surface textures uncommon (corrosion sculptures) or common (negative-oriented trigons, shield-shaped laminae and elongate hillocks) to kimberlitic diamonds. The near-liquidus melt of the Udachnaya kimberlite (Yakutia) with 10-12 wt% H2O is saturated with the Ol-Grt-px assemblage and may result from melting of carbonated garnet-bearing wehrlite. Hydrous kimberlitic melt likewise resorbs diamonds forming typical negative-oriented trigons, shield-shaped laminae and elongate hillocks on their surfaces. Therefore, the melts that could originate in the thermal conditions of subcratonic lithosphere, entrain diamond and dissolve it to produce dissolution features on crystal surfaces, were compositionally close to kimberlite (16-19 wt% SiO2) and rich in H2O. Dry Fe3+-bearing carbonatites with fO2 controlled by the ferric/ferrous equilibrium slightly above the Ni-NiO buffer cannot be diamond carriers.
DS201601-0005
2015
Sokol, A.G.Bataleva, Y.V., Palyanov, Y.N., Sokol, A.G., Borzdov, Y.M., Bayukov, O.A.Wustite stability in the presence of CO2 -fluid and a carbonate silicate melt: implications for the graphite/diamond formation and generation of Fe-rich mantle metasomatic agents.Lithos, in press available, 40p.MantleMelting
DS201602-0193
2016
Sokol, A.G.Bataleva, Y.V., Palyanov, Y.N., Sokol, A.G., Borzdov, Y.M., Bayukov, O.A.Wustite stability in the presence of CO2 fluid and a carbonate silicate melt: implications for the graphite/diamond formation and generation of Fe rich mantle metasomatic agents.Lithos, Vol. 244, pp. 20-29.GlobalFerropericlase inclusions

Abstract: Experimental simulation of the interaction of wüstite with a CO2-rich fluid and a carbonate-silicate melt was performed using a multianvil high-pressure split-sphere apparatus in the FeO-MgO-CaO-SiO2-Al2O3-CO2 system at a pressure of 6.3 GPa and temperatures in the range of 1150 °C–1650 °C and with run time of 20 h. At relatively low temperatures, decarbonation reactions occur in the system to form iron-rich garnet (Alm75Prp17Grs8), magnesiowüstite (Mg# ? 0.13), and CO2-rich fluid. Under these conditions, magnesiowüstite was found to be capable of partial reducing CO2 to C0 that leads to the formation of Fe3+-bearing magnesiowüstite, crystallization of magnetite and metastable graphite, and initial growth of diamond seeds. At T ? 1450 °C, an iron-rich carbonate-silicate melt (FeO ~ 56 wt.%, SiO2 ~ 12 wt.%) forms in the system. Interaction between (Fe,Mg)O, SiO2, fluid and melt leads to oxidation of magnesiowüstite and crystallization of fayalite-magnetite spinel solid solution (1450 °C) as well as to complete dissolution of magnesiowüstite in the carbonate-silicate melt (1550 °C–1650 °C). In the presence of both carbonate-silicate melt and CO2-rich fluid, dissolution (oxidation) of diamond and metastable graphite was found to occur. The study results demonstrate that under pressures of the lithospheric mantle in the presence of a CO2-rich fluid, wüstite/magnesiowüstite is stable only at relatively low temperatures when it is in the absolute excess relative to CO2-rich fluid. In this case, the redox reactions, which produce metastable graphite and diamond with concomitant partial oxidation of wüstite to magnetite, occur. Wüstite is unstable under high concentrations of a CO2-rich fluid as well as in the presence of a carbonate-silicate melt: it is either completely oxidized or dissolves in the melt or fluid phase, leading to the formation of Fe2 +- and Fe3 +-enriched carbonate-silicate melts, which are potential metasomatic agents in the lithospheric mantle.
DS201602-0240
2016
Sokol, A.G.Sokol, A.G., Kruk, A.N., Chebotarev, D.A., Palynaov, Yu.N., Sobolev, N.V.Conditions of carbonation and wehrlitization of lithospheric peridotite upon interaction with carbonatitic melts.Doklady Earth Sciences, Vol. 465, 2, pp. 1262-1267.RussiaDeposit - Udachnaya

Abstract: Study of the mechanism of carbonation and wehrlitization of harzburgite upon metasomatism by carbonatitic melts of various genesis was carried out. Experiments with durations of 60-150 h were performed at 6.3 GPa and 1200°C. The data showed that carbonatite with MgO/CaO > 0.3 percolating into the peridotitic lithosphere may provide crystallization of magnesite in it. The influence of all studied carbonatites results in wehrlitization of peridotite. The compositions of melts formed by interaction with harzburgite (?2 wt % SiO2, Ca# = 36-47) practically do not depend on the composition of the initial carbonatite. Based on the data obtained, we conclude that the formation of magnesite-bearing and magnesite-free metasomatized peridotites may have a significant influence on the CO2 regime in the further generation of kimberlitic magmas of groups I and II.
DS201604-0630
2016
Sokol, A.G.Sokol, A.G., Kruk, A.N., Chebotarev, D.A., Palyanov, Y.N.Carbonatite melt-peridotite interaction at 5.5- 7.0 Gpa: implications for metasomatism in lithospheric mantle. KimberliteLithos, Vol. 248-251, pp. 66-79.MantleMetasomatism

Abstract: Interaction between carbonatite melt and peridotite is studied experimentally by melting samples of interlayered peridotite-carbonatite-peridotite in graphite containers at 1200-1350 °C and 5.5-7.0 GPa in a split-sphere multianvil apparatus. Starting compositions are lherzolite and harzburgite, as well as carbonatite which may form in the upper part of a slab or in a plume-related source. Most experimental runs were of 150 h duration in order for equilibrium to be achieved. The interaction produced carbonatitic melts with low SiO2 (? 7 wt.%) and high alkalis. At 1200 °C, melt-peridotite interaction occurs through Mg-Ca exchange, resulting in elimination of orthopyroxene and crystallization of magnesite and clinopyroxene. At 1350 °C hybridization of the carbonatite and magnesite-bearing peridotite melts occurred with consumption of clinopyroxene and magnesite, and crystallization of orthopyroxene at MgO/CaO ? 4.3. The resulting peridotite-saturated melt has Ca# (37-50) depending on primary carbonatite composition. Compositions of silicate phases are similar to those of high-temperature peridotite but are different from megacrysts in kimberlites. CaO and Cr2O3 changes in garnet produced from the melt-harzburgite interaction at 1200 and 1350 °C perfectly match the observed trend in garnet from metasomatized peridotite of the Siberian subcontinental lithospheric mantle. K-rich carbonatite melts equilibrated with peridotite at 5.5-7.0 GPa and 1200-1350 °C correspond to high-Mg inclusions in fibrous diamond. Carbonatite melt is a weak solvent of entrained xenoliths and therefore cannot produce kimberlitic magma if temperatures are ~ 1350 °C on separation from the lithospheric peridotite source and ~ 1000 °C on eruption.
DS201606-1101
2016
Sokol, A.G.Kruk, A.N., Sokol, A.G., Chebotarev, D.A., Palyanov, Yu.A., Sobolev, N.V.Composition of a carbonatitic melt in equilibrium with lherzolite at 5.5-6.3 Gpa and 1350C.Doklady Earth Sciences, Vol. 467, 1, pp. 303-307.Carbonatite

Abstract: Generation of ultra-alkaline melts by the interaction of lherzolite with cardonatites of various genesis was simulated at the P-T parameters typical of the base of the subcratonic lithosphere. Experiments with a duration of 150 h were performed at 5.5 and 6.3 GPa and 1350°C. The concentrations of CaO and MgO in melts are buffered by the phases of peridotite, and the concentrations of alkalis and FeO depend on the composition of the starting carbonatite. Melts are characterized by a low (<7 wt %) concentration of SiO2 and Ca# from 0.40 to 0.47. It is demonstrated that only high-Mg groups of carbonatitic inclusions in fibrous diamonds have a composition close to that of carbonatitic melts in equilibrium with lherzolite. Most likely, the formation of kimberlite-like melts relatively enriched in SiO2 requires an additional source of heat from mantle plumes and probably H2O fluid.
DS201608-1431
2016
Sokol, A.G.Palyanov, Y.N., Kupriyanov, I.N., Sokol, A.G., Borzdov, Y.M., Khokhryakov, A.F.Effect of CO2 on crystallization and properties of diamond from ultra-alkaline carbonate melt.Lithos, in press available, 12p.TechnologyDiamond formation

Abstract: An experimental study on diamond crystallization in CO2-rich sodium-carbonate melts has been undertaken at a pressure of 6.3 GPa in the temperature range of 1250-1570 °C and at 7.5 GPa in the temperature range of 1300-1700 °C. Sodium oxalate (Na2C2O4) was used as the starting material, which over the course of the experiment decomposed to form sodium carbonate, carbon dioxide and elemental carbon. The effects of pressure, temperature and dissolved CO2 in the ultra-alkaline carbonate melt on diamond crystallization, morphology, internal structure and defect-and-impurity content of diamond crystals are established. Diamond growth is found to proceed with formation of vicinal structures on the {100} and {111} faces, resulting eventually in the formation of rounded polyhedrons, whose shape is determined by the combination tetragon-trioctahedron, trigon-trioctahedron and cube faces. Spectroscopic studies reveal that the crystallized diamonds are characterized by specific infrared absorption and photoluminescence spectra. The defects responsible for the 1065 cm? 1 band dominating in the IR spectra and the 566 nm optical system dominating in the PL spectra are tentatively assigned to oxygen impurities in diamond.
DS201610-1844
2016
Sokol, A.G.Bataleva, Y.V., Palyanov, Y.N., Borzdov, Y.M., Kupriyanov, I.N., Sokol, A.G.Synthesis of diamonds with mineral, fluid and melt inclusions.Lithos, in press available 12p.TechnologyDiamond inclusions

Abstract: Experiments on the synthesis of inclusions-bearing diamond were performed in the SiO2-((Mg,Ca)CO3-(Fe,Ni)S system at 6.3 GPa and 1650-1750 °C, using a multi-anvil high pressure apparatus of the "split-sphere" type. Diamond synthesis was realized in the "sandwich-type" experiments, where the carbonate-oxide mixture acted as a source of both CO2-dominated fluid and carbonate-silicate melt, and Fe,Ni-sulfide played a role of reducing agent. As a result of redox reactions in the carbonate-oxide-sulfide system, diamond was formed in association with graphite and Mg,Fe-silicates, coexisting with CO2-rich fluid, carbonate-silicate and sulfide melts. The synthesized diamonds are predominantly colorless or light-yellow monocrystals with octahedral habit (20-200 ?m), and polycrystalline aggregates (300-400 ?m). Photoluminescence spectroscopy revealed defects related to nickel impurity (S3 optical centers), which are characteristic of many diamonds in nature. The density of diamond crystallization centers over the entire reaction volume was ~3 × 102-103 cm? 3. The overwhelming majority of diamonds synthesized were inclusions-bearing. According to Raman spectroscopy data, diamond trapped a wide variety of inclusions (both mono- and polyphase), including orthopyroxene, olivine, carbonate-silicate melt, sulfide melt, CO2-fluid, graphite, and diamond. The Raman spectral pattern of carbonate-silicate melt inclusions have bands characteristic of magnesite and orthopyroxene (± SiO2). The spectra of sulfide melt displayed marcasite and pyrrhotite peaks. We found that compositions of sulfide, silicate and carbonate phases are in good agreement not only with diamond crystallization media in experiments, but with data on natural diamond inclusions of peridotitic and eclogitic parageneses. The proposed methodological approach of diamond synthesis can be used for experimental simulation of the formation of several types of mineral, fluid and melt inclusions, observed in natural diamonds.
DS201705-0876
2017
Sokol, A.G.Sokol, A.G., Kruk, A.N., Palynov, Y.N., Sobolev, N.V.Stability of phlogopite in ultrapotassic kimberlite-like systems at 5.5-7.5 Gpa.Contributions to Mineralogy and Petrology, in press available 22p.MantleMetasomatism, magmatism, carbonatite

Abstract: Hydrous K-rich kimberlite-like systems are studied experimentally at 5.5-7.5 GPa and 1200-1450 °C in terms of phase relations and conditions for formation and stability of phlogopite. The starting samples are phlogopite-carbonatite-phlogopite sandwiches and harzburgite-carbonatite mixtures consisting of Ol + Grt + Cpx + L (±Opx), according to the previous experimental results obtained at the same P-T parameters but in water-free systems. Carbonatite is represented by a K- and Ca-rich composition that may form at the top of a slab. In the presence of carbonatitic melt, phlogopite can partly melt in a peritectic reaction at 5.5 GPa and 1200-1350 °C, as well as at 6.3-7.0 GPa and 1200 °C: 2Phl + CaCO3 (L)?Cpx + Ol + Grt + K2CO3 (L) + 2H2O (L). Synthesis of phlogopite at 5.5 GPa and 1200-1350 °C, with an initial mixture of H2O-bearing harzburgite and carbonatite, demonstrates experimentally that equilibrium in this reaction can be shifted from right to left. Therefore, phlogopite can equilibrate with ultrapotassic carbonate-silicate melts in a ? 150 °C region between 1200 and 1350 °C at 5.5 GPa. On the other hand, it can exist but cannot nucleate spontaneously and crystallize in the presence of such melts in quite a large pressure range in experiments at 6.3-7.0 GPa and 1200 °C. Thus, phlogopite can result from metasomatism of peridotite at the base of continental lithospheric mantle (CLM) by ultrapotassic carbonatite agents at depths shallower than 180-195 km, which creates a mechanism of water retaining in CLM. Kimberlite formation can begin at 5.5 GPa and 1350 °C in a phlogopite-bearing peridotite source generating a hydrous carbonate-silicate melt with 10-15 wt% SiO2, Ca# from 45 to 60, and high K enrichment. Upon further heating to 1450 °C due to the effect of a mantle plume at the CLM base, phlogopite disappears and a kimberlite-like melt forms with SiO2 to 20 wt% and Ca# = 35-40.
DS201712-2717
2017
Sokol, A.G.Persikov, E.S., Bukhtiyarov, P.G., Sokol, A.G.Viscosity of hydrous kimberlite and basaltic melts at high pressures.Russian Geology and Geophysics, Vol. 58, pp. 1093-1100.Mantlekimberlite

Abstract: New experimental data on the temperature and pressure dependences of the viscosity of synthetic hydrous kimberlite melts (82 wt.% silicate + 18 wt.% carbonate; degree of depolymerization: 100NBO/T = 313 for anhydrous melts and 100NBO/T = 247 for melts with 3 wt.% H2O) were obtained at a water pressure of 100 MPa and at lithostatic pressures of 5.5 and 7.5 GPa in the temperature range 1300-1950 °C. The temperature dependence of the viscosity of these melts follows the exponential Arrhenius-Frenkel-Eyring equation in the investigated range of temperatures and pressures. The activation energies of viscous flow for hydrous kimberlite melts were first shown to increase linearly with increasing pressure. Under isothermal conditions (T = 1800 °C), the viscosity of hydrous kimberlite melts increases exponentially by about an order of magnitude as the pressure increases from 100 MPa to 7.5 GPa. The new experimental data on the viscosity of hydrous kimberlite melts (error ± 30 rel.%) are compared with forecast viscosity data for anhydrous kimberlite and basaltic melts (100NBO/T = 51.5) and for hydrous basaltic melts (100NBO/T = 80). It is shown that at comparable temperatures, the viscosity of hydrous kimberlite melts at a moderate pressure (100 MPa) is about an order of magnitude lower than the viscosity of hydrous basaltic melts, whereas at a high pressure (7.5 GPa) it is more than twice higher. It is first established that water dissolution in kimberlite melts does not affect seriously their viscosity (within the measurement error) at both moderate (100 MPa) and high (7.5 GPa) pressures, whereas the viscosity of basaltic melts considerably decreases with water dissolution at moderate pressures (100 MPa) and remains unchanged at high pressures (P > 3.5 GPa).
DS201803-0470
2017
Sokol, A.G.Persikov, E.S., Bukhtiyarov, P.G., Sokol, A.G.Viscosity of hydrous kimberlite and basaltic melts at high pressures.Russian Geology and Geophysics, Vol. 58, pp. 1093-1100.Mantlemelting

Abstract: New experimental data on the temperature and pressure dependences of the viscosity of synthetic hydrous kimberlite melts (82 wt.% silicate + 18 wt.% carbonate; degree of depolymerization: 100NBO/T = 313 for anhydrous melts and 100NBO/T = 247 for melts with 3 wt.% H2O) were obtained at a water pressure of 100 MPa and at lithostatic pressures of 5.5 and 7.5 GPa in the temperature range 1300-1950 °C. The temperature dependence of the viscosity of these melts follows the exponential Arrhenius-Frenkel-Eyring equation in the investigated range of temperatures and pressures. The activation energies of viscous flow for hydrous kimberlite melts were first shown to increase linearly with increasing pressure. Under isothermal conditions (T = 1800 °C), the viscosity of hydrous kimberlite melts increases exponentially by about an order of magnitude as the pressure increases from 100 MPa to 7.5 GPa. The new experimental data on the viscosity of hydrous kimberlite melts (error ± 30 rel.%) are compared with forecast viscosity data for anhydrous kimberlite and basaltic melts (100NBO/T = 51.5) and for hydrous basaltic melts (100NBO/T = 80). It is shown that at comparable temperatures, the viscosity of hydrous kimberlite melts at a moderate pressure (100 MPa) is about an order of magnitude lower than the viscosity of hydrous basaltic melts, whereas at a high pressure (7.5 GPa) it is more than twice higher. It is first established that water dissolution in kimberlite melts does not affect seriously their viscosity (within the measurement error) at both moderate (100 MPa) and high (7.5 GPa) pressures, whereas the viscosity of basaltic melts considerably decreases with water dissolution at moderate pressures (100 MPa) and remains unchanged at high pressures (P > 3.5 GPa).
DS201810-2365
2018
Sokol, A.G.Persikov, E.S., Bukhityarov, P.G., Sokol, A.G.Viscosity of haplokimberlitic and basaltic melts at high pressures: experimental and theoretical studies.Chemical Geology, Vol. 497, pp. 54-63.MantleUHP

Abstract: Only limited data are available at present on the viscosity of kimberlite magmas. We investigate viscosity of synthetic carbonate-bearing (silicate82?+?carbonate18, wt%, 100NBO/T?=?313) anhydrous haplokimberlite melts theoretically and in experiments. We use new experimental data on viscosity of anhydrous haplokimberlite melts and a physical-chemical model (Persikov and Bukhtiyarov 2009; Persikov et al. 2015) to compare basic viscosity features in kimberlitic and basaltic melts (100NBO/T?=?56). Viscosity of melts is determined by the falling sphere quenching method in a large range of temperatures from 1300 to 1950?°C and pressures up to 7.5?GPa. We use two types of high-pressure apparatuses: a high gas pressure apparatus and a high pressure split-sphere multi-anvil apparatus to study the viscosity of melts at moderate (100?MPa CO2 pressure) and high (5.5?GPa and 7.5?GPa) pressures, respectively. The measured viscosity ranges for anhydrous haplokimberlite melts are from 1.5 (±0.45) to 0.11(±0.03) Pa s. The temperature dependence of the viscosity of haplokimberlite and basaltic melts is consistent with the theoretical Arrhenian equation. At a constant temperature, viscosity of anhydrous haplokimberlite melts increases exponentially about ten-fold as pressure increases from 100?MPa to 7.5?GPa. The activation energy of viscous flow increases linearly with pressure increase from 100?MPa to 7.5?GPa for anhydrous haplokimberlite melts but decreases in the case of basaltic melts, with the minimum at ~5.5?GPa. At a moderate pressure (100?MPa), haplokimberlite melts are about twenty times less viscous than basaltic melts, but are about four times more viscous at a high pressure (7.5?GPa), the temperature being 1800?°C in both cases. The experimentally observed behavior of the viscosity of anhydrous haplokimberlite melts is consistent with predictions of the physical-chemical model within the range of uncertainties in both experimental and calculated data (±30% rel.). Thus, the physical-chemical model is used to discuss possible effects of volume percentages of crystals and bubbles on viscosity of kimberlitic and basaltic magmas at different pressures and temperatures during their origin, evolution, and ascent.
DS201812-2834
2018
Sokol, A.G.Kruk, A.N., Sokol, A.G., Palyanov, Yu.N.Phase relations in the harzburgite-hydrous carbonate melt at 5.5-7.5 Gpa and 1200-1350 C. ( primary kimberlite)Petrology, Vol. 26, 6, pp. 575-587.Mantlemetasomatism

Abstract: Phase relations are studied experimentally in the harzburgite-hydrous carbonate melt system, the bulk composition of which represents primary kimberlite. Experiments were carried out at 5.5 and 7.5 GPa, 1200-1350°?, and \({{X}_{{{\text{C}}{{{\text{O}}}_{2}}}}}\) = 0.39-0.57, and lasted 60 hours. It is established that olivine-orthopyroxene-garnet-magnesite-melt assemblage is stable within the entire range of the studied parameters. With increase of temperature and \({{X}_{{{\text{C}}{{{\text{O}}}_{2}}}}}\) in the system, Ca# in the melt and the olivine fraction in the peridotite matrix significantly decrease. The composition of silicate phases in run products is close to those of high-temperature mantle peridotite. Analysis of obtained data suggest that magnesite at the base of subcontinental lithosphere could be derived by metasomatic alteration of peridotite by asthenospheric hydrous carbonate melts. The process is possible in the temperature range typical of heat flux of 40-45 mW/m², which corresponds to the conditions of formation of the deepest peridotite xenoliths. Crystallization of magnesite during interaction with peridotite matrix can be considered as experimentally substantiated mechanism of CO2 accumulation in subcratonic lithosphere.
DS202008-1449
2020
Sokol, A.G.Sokol, I.A., Sokol, A.G., Zaikin, P.A., Tomilenko, A.A., Bulbak, T.A.Hydrogenation of graphite, diamond, carbonates and iron carbides as the source of hydrocarbons in the upper mantle.Goldschmidt 2020, 1p. AbstractMantlehydrogen

Abstract: Formation of hydrocarbons by reactions of hydrogenbearing fluids with carbon [1] (13C soot, graphite, or diamond), carbonate-bearing pelites [2] and iron carbides (Fe3C and Fe7C3) [3] was simulated at 5.5-7.8 GPa and 1100- 1400°C, fH2 in Pt and Au capsules being controlled at the Mo+MoO2+H2O or Fe+FeO+H2O equilibria. For the first time, formation of hydrocarbons from inorganic compounds was proved by the reaction of 13C with hydrogen, which yielded isotopically pure alkanes. The greatest amounts of HCs (CH4/C2H6 < 1, CH4/C3H8 and CH4/C4H10 ? 10) formed at 1400°C in the 10-hr run. The amount of HCs synthesized at 1200°C was twice smaller. The rate of HCs formation was slowest in runs with diamond. At 1200 °C, light alkanes (C1?C2>C3>C4) formed either by direct hydrogenation of Fe3C or Fe7C3, or by hydrogenation of graphite/diamond in the presence of Fe3C, Fe7C3. The CH4/C2H6 ratio in the fluids decreased from 5 to 0.5 with decreasing iron activity and the C fraction increased in the series: Fe-Fe3C?Fe3C- Fe7C3?Fe7C3-graphite?graphite-Fe3C-magnesite and Fe3C-H2O-CO2 systems at 1200 °C yielded magnesiowüstite and wüstite, respectively, and both produced C-rich Fe7C3 and mainly light alkanes (C1?C2>C3>C4). In the experiments containing pelites methaneimine (CH3N) was found to be the main N-bearing compound. The experiments have provided the first unambiguous evidence that volatile-rich and reduced mantles of terrestrial planets (at fO2 near or below IW) provided favorable conditions for abiotic generation of complex hydrocarbon systems that predominantly contain light alkanes. The conditions favorable for HC formation exist in earth mantle, where slab-derived H2O-, CO2- and carbonate-bearing fluids interact with metal-saturated mantle.
DS202102-0213
2021
Sokol, A.G.Palyanov, Y.N., Borzdov, Y.M., Sokol, A.G., Btaaleva, Y.V., Kupriyanov, I.N., Reitsky, V.N., Wiedenbeck, M., Sobolev, N.V.Diamond formation in an electric field under deep Earth conditions.Science Advances, Vol. 7, 4, eabb4644 doi: 10.1126/ sciadv.abb4644 28p. PdfMantlegeophysics

Abstract: Most natural diamonds are formed in Earth’s lithospheric mantle; however, the exact mechanisms behind their genesis remain debated. Given the occurrence of electrochemical processes in Earth’s mantle and the high electrical conductivity of mantle melts and fluids, we have developed a model whereby localized electric fields play a central role in diamond formation. Here, we experimentally demonstrate a diamond crystallization mechanism that operates under lithospheric mantle pressure-temperature conditions (6.3 and 7.5 gigapascals; 1300° to 1600°C) through the action of an electric potential applied across carbonate or carbonate-silicate melts. In this process, the carbonate-rich melt acts as both the carbon source and the crystallization medium for diamond, which forms in assemblage with mantle minerals near the cathode. Our results clearly demonstrate that electric fields should be considered a key additional factor influencing diamond crystallization, mantle mineral-forming processes, carbon isotope fractionation, and the global carbon cycle.
DS202103-0410
2021
Sokol, A.G.Sokol, A.G., Kruk, A.N.Role of CO2 in the evolution of kimberlite magma: experimental constraints at 5.5GPa and 1200-1450 C.Lithos, in press available, 13p. PdfGlobalmagmatism

Abstract: According to the existing models of kimberlite origin, free exsolution CO2 may be an important agent in the evolution of primary kimberlite magma and initiation of crack propagation. We study the reaction of garnet lherzolite with carbonatitic melt rich in molecular CO2 and H2O in experiments at 5.5 GPa and 1200-1450 °C. The experimental results show that carbonation of olivine with formation of orthopyroxene and magnesite can buffer the contents of molecular CO2 in the melt, which impedes immediate separation of CO2 fluid from melt equilibrated with the peridotite source. The solubility of molecular CO2 in the melt decreases from 20 -25 wt% at 4.5-6.8 wt% SiO2 typical of carbonatite to below 7-12 wt% in more silicic melts with 26-32 wt% SiO2. Interaction of garnet lherzolite with carbonatitic melt (at a weight proportion of 2:1) in the presence of 2-3 wt% H2O and 17-24 wt% of total CO2 at 1200-1450 °C yields low-SiO2 (<10 wt%) alkali?carbonated melts, which shows multiphase saturation with magnesite-bearing garnet harzburgite. Thus, carbonatitic melts rich in volatiles can originate in a harzburgite source at moderate temperatures common to continental lithospheric mantle (CLM). Excessive volatiles may be present in carbonatitic melts not equilibrated with the peridotitic source due to the formation of metasomatic reaction zones. Having separated from the source, carbonatitic magma enriched in molecular CO2 and H2O can rapidly become more silicic (>25 wt% SiO2) by dissolution and carbonation of entrapped peridotite. Furthermore, interaction of garnet lherzolite with carbonatitic melt rich in K, CO2, and H2O at 1350 °C produces immiscible carbonate-silicate and K-rich silicate melts. Quenched silicate melt develops globules of foam-like vesicular glass. Differentiation of immiscible melts early during their ascent may equalize the compositions of kimberlite magmas generated in different CLM sources. The fluid phase can release explosively from ascending magma at lower pressures as a result of SiO2 increase which reduces the solubility of CO2 and due to the decarbonation reaction of magnesite and orthopyroxene.
DS202105-0771
2021
Sokol, A.G.Khokhryakov, A., Kruk, A.N., Sokol, A.G.The effect of oxygen fugacity on diamond resorption in ascending kimberlite melt.Lithos, 10.1016/j.lithos.2021.106166, 12p.Russiadeposit - Udachnaya

Abstract: When transported by magmas to the Earth's surface, diamond crystals underwent resorption, the intensity of which significantly differed in various kimberlite pipes. We experimentally simulated diamond resorption at different oxygen fugacities (fO2) in ascending kimberlite magma enriched in CO2 and H2O. The experiments were carried out using specially prepared unaltered Group I kimberlite from the Udachnaya East pipe (Yakutia) and model carbonatite at 3.0 GPa, 1200-1400 °C, and fO2 in a range of NNO-2 to NNO + 3.2 log units (where NNO is Ni-NiO buffer). Over the investigated range of conditions, resorption of octahedral diamond crystals is found to occur according to a single scenario. Negative trigons and shield-shaped laminae develop on the {111} faces and crystal edges are truncated by the surfaces of tetrahexahedroids. The rate of diamond resorption increases in all studied systems as fO2 and temperature are raised. In this case, water-enriched melts are the most aggressive media in the investigated T-fO2 interval. Among the most oxidized high-temperature melts, it is carbonatite melts depleted in SiO2 that provide the maximum rate of diamond resorption. Furthermore, the rates of diamond resorption we obtained are an order of magnitude higher than those previously measured in silicate melts containing CO2 and H2O, at fO2 values from the NNO buffer to NNO-2. Therefore, high oxygen fugacity, a temperature of ~1400 °C, and essentially carbonate composition of water-containing magma could provide a high intensity of diamond resorption at the mantle stage of magma ascent to the surface. Apparently, this process primarily influenced the formation of the appearance and preservation of natural diamond crystals in kimberlite pipes.
DS202112-1933
2020
Sokol, A.G.Khokhryakov, A., Nechaev, D.V., Sokol, A.G.Microrelief of rounded diamond crystals as an indicator of the redox conditions of their resorption in a kimberlite melt.Crystals, Vol. 10, 12p. Pdf Russiadiamond morphology

Abstract: We conducted a detailed study of the morphology of diamond crystals partially dissolved in a water-bearing kimberlite melt at pressure of 6.3 GPa, temperature of 1400 °C, and two oxygen fugacities (fO2) corresponding to the Re-ReO2 buffer and near the magnetite-hematite (MH) buffer. The triangular etch pits on the {111} faces, which formed during experimental diamond dissolution, were found to completely correspond to negative trigons on natural diamond crystals in the shape and sidewalls inclination angle. Furthermore, two experimental fO2 values were associated with two relief types of the rounded tetrahexahedroid surfaces typical of natural rounded diamonds. Therefore, the surface microrelief on rounded natural diamond crystals was concluded to be an indicator of the redox conditions of natural diamond resorption.
DS202205-0695
2022
Sokol, A.G.Khokhryakov, A.F., Kruk, A.N., Sokol, A.G., Nechaev, D.V.Experimental modeling of diamond reportion during mantle metasomatism.Minerals ( MDPI), Vol. 12, 4, pp. 414-MantleMetasomatism

Abstract: The morphology of resorbed diamond crystals is a valuable source of information on the composition and ascent rate of kimberlite magmas, as well as on possible redox conditions in protolith. Previously, diamond resorption was thoroughly investigated at P-T-fO2 parameters of the kimberlite magma ascent. In this study, we investigated diamond resorption using unaltered group I kimberlite and model carbonatite at P-T-fO2 parameters that are typical of the peridotite source of kimberlite magmas in the subcontinental lithospheric mantle. An analysis of previous studies made it possible to determine the rate of diamond octahedron transformation into a spherical tetrahexahedron depending on the composition of the carbonate-silicate melt. It was shown that the rate of diamond resorption at 6.3 GPa increases in all the investigated systems as fO2 and temperature rise. There is a steady decrease in the diamond resorption rate as pressure increases from 1 GPa to 6.3 GPa. The morphology comparison of the experimentally produced samples with natural diamonds is indicative of the significant contribution of metasomatic alteration of protolith by the oxidized agent and at the initial stages of kimberlite magma ascent to the resorption of natural diamonds.
DS202205-0719
2022
Sokol, A.G.Sokol, A.G., Kruk, A.N., Persikov, E.S.Dissolution of peridotite in a volatile-rich carbonate melt as a mechanism of the formation of kimberlite-like melts ( experimental constraints).Doklady Earth Science, Vol. 503, 2, pp. 157-163.Globalkimberlite magmatism

Abstract: In the experiments at 3.0-6.3 GPa and 1200-1350°C, it is found that under P-T parameters close to the conditions in ascending kimberlite magma, the carbonate melt enriched in potassium and volatiles is able to dissolve effectively the entire amount of xenogenic peridotite material that can potentially transport. As a result of this process, the melt is enriched in SiO2 (up to 30 wt %) and is transformed from carbonate to a kimberlite-like one. In the range of parameters studied, due to the high solubility of CO2 in the melt and the appearance of magnesite, an equilibrium fluid phase is not formed in the system. The interaction realized in the experiments may be the most important factor at the initial stage of magma evolution. The calculations performed in this work show that even after the dissolution of 30-50 wt % of lherzolite, the volatile-rich carbonate-silicate melt has a high degree of depolymerization (the ratio of the number of nonbridging oxygen atoms to the number of tetrahedrally coordinated ions (100NBO/T from 250 to 390) remains low-viscous (0.3-32.6 Pa s) and able to ascend to the surface rapidly. The obtained data indicate that immiscibility occurs between the potassium-rich carbonate-silicate and highly silicate melts only at 5.5 GPa and 1350°C and is likely to have a minor impact on the evolution of magma.
DS202008-1449
2020
Sokol, I.A.Sokol, I.A., Sokol, A.G., Zaikin, P.A., Tomilenko, A.A., Bulbak, T.A.Hydrogenation of graphite, diamond, carbonates and iron carbides as the source of hydrocarbons in the upper mantle.Goldschmidt 2020, 1p. AbstractMantlehydrogen

Abstract: Formation of hydrocarbons by reactions of hydrogenbearing fluids with carbon [1] (13C soot, graphite, or diamond), carbonate-bearing pelites [2] and iron carbides (Fe3C and Fe7C3) [3] was simulated at 5.5-7.8 GPa and 1100- 1400°C, fH2 in Pt and Au capsules being controlled at the Mo+MoO2+H2O or Fe+FeO+H2O equilibria. For the first time, formation of hydrocarbons from inorganic compounds was proved by the reaction of 13C with hydrogen, which yielded isotopically pure alkanes. The greatest amounts of HCs (CH4/C2H6 < 1, CH4/C3H8 and CH4/C4H10 ? 10) formed at 1400°C in the 10-hr run. The amount of HCs synthesized at 1200°C was twice smaller. The rate of HCs formation was slowest in runs with diamond. At 1200 °C, light alkanes (C1?C2>C3>C4) formed either by direct hydrogenation of Fe3C or Fe7C3, or by hydrogenation of graphite/diamond in the presence of Fe3C, Fe7C3. The CH4/C2H6 ratio in the fluids decreased from 5 to 0.5 with decreasing iron activity and the C fraction increased in the series: Fe-Fe3C?Fe3C- Fe7C3?Fe7C3-graphite?graphite-Fe3C-magnesite and Fe3C-H2O-CO2 systems at 1200 °C yielded magnesiowüstite and wüstite, respectively, and both produced C-rich Fe7C3 and mainly light alkanes (C1?C2>C3>C4). In the experiments containing pelites methaneimine (CH3N) was found to be the main N-bearing compound. The experiments have provided the first unambiguous evidence that volatile-rich and reduced mantles of terrestrial planets (at fO2 near or below IW) provided favorable conditions for abiotic generation of complex hydrocarbon systems that predominantly contain light alkanes. The conditions favorable for HC formation exist in earth mantle, where slab-derived H2O-, CO2- and carbonate-bearing fluids interact with metal-saturated mantle.
DS201912-2827
2019
Sokol, K.Sokol, K., Prelevic, D., Romer, R.L., Cokulov, N.Cretaceous ultrapotassic magmatism from the Sava-Vardar zone of the BalkansLithos, doi:10.1016/j.lithos.2019.105268Europemagmatism

Abstract: Late Cretaceous global plate reorganization associated with the inception of counterclockwise rotation of Africa relative to Europe initiated in the Balkan region small-volume magmatism of diverse geochemical signature along the enigmatic Sava-Vardar Zone. We study a Late Cretaceous lamprophyric sill in Ripanj village near Belgrade to constrain this magmatic episode. The lamprophyre is characterized by high contents of Na, P, Fe and Al, and low contents of K, Ca and Mg. Its original nature (Na, K, Ca and Mg) is concealed by intense alteration (albitization of feldspar and partial chloritization of phlogopite) that erased the ultrapotassic affinity of the rocks and resulted in extremely low K/Na ratios. The recalculated chemical composition demonstrates that the rocks are ultrapotassic, with K2O and MgO > 3 wt % and K2O/Na2O > 2, and belong to the durbachite-vaugnerite series, i. e., the plutonic equivalents of minettes and kersantites. Two phlogopite concentrates gave Ar-Ar ages of 86.80 ± 0.5 Ma and 86.90 ± 0.5 Ma. Our combined elemental and Sr-Nd-Pb isotope data (87Sr/86Sr 0.70667-0.70677, 143Nd/144Nd 0.512426-0.512429, 206Pb/204Pb 18.82-19.13, 207Pb/204Pb 15.67-15.68, 208Pb/204Pb 38.92-39.19) for representative lamprophyric samples suggests magma derivation from a light rare earth elements (LREE) and K enriched, metasomatized mantle source. The content of LREE of the rocks is enriched, whereas heavy rare earth elements (HREE) is depleted. Rare earth elements (REE) of the whole rock and REE of diopside all indicate that garnet was present in their source. There are two viable and mutually-excluding geodynamic scenarios for the Late Cretaceous magmatism in the Balkans: (i) If the Sava-Vardar ocean still existed in the Late Cretaceous and was subducted under the European plate with arc volcanism along the Apuseni-Banat-Timok-Panagyurishte-Srednjogorje belt, coeval magmatism in the Sava-Vardar Zone occurred in a fore-arc setting, and may be related to ridge subduction; (ii) If the Mesozoic ocean closed already during the Upper Jurassic or Lower Cretaceous, the Late Cretaceous volcanism within the Sava-Vardar Zone represents intracontinental volcanism associated with transtensional tectonics.
DS202204-0536
2022
Sokol, K.Sokol, K., Finch, A.A., Hutchison, W., Cloutier, J., Borst, A.M., Humphreys, M.C.S.Quantifying metasomatic high-field-strength and rare-earth element transport from alkaline magmas.Geology, Vol. 50, 3, pp. 305-310.Europe, Greenlandalkaline

Abstract: Alkaline igneous rocks host many global high-field-strength element (HFSE) and rare-earth element (REE) deposits. While HFSEs are commonly assumed to be immobile in hydrothermal systems, transport by late-stage hydrothermal fluids associated with alkaline magmas is reported. However, the magnitude of the flux and the conditions are poorly constrained and yet essential to understanding the formation of REE-HFSE ores. We examined the alteration of country rocks (“fenitization”) accompanying the emplacement of a syenite magma at Illerfissalik in Greenland, through analysis of changes in rock chemistry, mineralogy, and texture. Our novel geochemical maps show a 400-m-wide intrusion aureole, within which we observed typically tenfold increases in the concentrations of many elements, including HFSEs. Textures suggest both pervasive and structurally hosted fluid flow, with initial reaction occurring with the protolith's quartz cement, leading to increased permeability and enhancing chemical interaction with a mixed Ca-K-Na fenitizing fluid. We estimated the HFSE masses transferred from the syenite to the fenite by this fluid and found ~43 Mt of REEs were mobilized (~12% of the syenite-fenite system total rare-earth-oxide [TREO] budget), a mass comparable to the tonnages of some of the world's largest HFSE resources. We argue that fenite can yield crucial information about the tipping points in magma evolution because retention and/or loss of volatile-bonded alkali and HFSEs are key factors in the development of magmatic zirconosilicate-hosted HFSE ores (e.g., Kringlerne, at Ilímaussaq), or the formation of the syenite-hosted Nb-Ta-REE (Motzfeldt-type) roof-zone deposits.
DS1985-0585
1985
Sokolina, G.A.Samolov, M.I., Sokolina, G.A., Iakovlev, E.N.Specific Features of Graphite-diamond Phase TransformationDoklady Academy of Sciences Nauk SSSR., Vol. 282, No. 3, PP. 617-619.RussiaMineralogy
DS1995-1351
1995
SokolovNikitina, 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
DS1994-1661
1994
Sokolov, A.L.Sokolov, A.L., Viljoen, R.P., Scheglov, A.D.Mineral provinces and tectonic regimes: ancient platforms, mobile belts and zones of tectonic-magmaticExploration and Mining Geology, Vol. 3, No. 4, Oct. pp. 315-328South Africa, RussiaMetallogeny -overview, Tectonics, belts, zones
DS1982-0576
1982
Sokolov, B.N.Sokolov, B.N.The Formation of Diamond Placers; Basic ProblemsMoscow: Izd. Nauka., 96P.RussiaDiamond Origin, Alluvial Placer Deposits, Kimberley
DS201212-0448
2012
Sokolov, M.Martin, R.F., Sokolov, M., Magaji, S.S.Punctuated anorogenic magmatism.Lithos, Vol. 152, pp. 132-140.Canada, Greenland, Russia, AfricaMagmatism
DS1998-1533
1998
Sokolov, S.Veksler, I.V., Nielsen, T., Sokolov, S.Mineralogy of crystallized melt inclusions from Gardiner and Kovdorul tramafic alkaline complexes...Journal of Petrology, Vol. 39, No. 11-12, Nov-Dec. pp. 2015-31.Greenland, Russia, Kola PeninsulaCarbonatite, genesis, Deposit - Gardiner, Kovdor
DS2002-0350
2002
Sokolov, S.Danyushevsky, L.V., Sokolov, S., Falloon, T.J.Melt inclusions in olivine phenocrysts: using diffusive re-equilibration to determine theJournal of Petrology, Vol. 43, 9, Sept.pp. 1651-72.GlobalOlivine rocks
DS2002-1522
2002
Sokolov, S.Sokolov, S.Melt inclusions as indicators of the magmatic origin of carbonatite rare metal and rare earth minerals.Chemical Geology, Vol.183, 1-4, pp.373-8.GlobalMagmatism, Carbonatite
DS2003-1310
2003
Sokolov, S.D.Sokolov, S.D.Accretionary tectonics: the state of the artGeotectonics, Vol. 37, 1, pp. 1-14.GlobalTectonics, Review
DS1975-0627
1977
Sokolov, S.V.Sokolov, S.V.Distribution of Trace Elements in Magnetites of Ultrabasic Alkalic and Carbonatite Massif Rocks.Zap. Vses. Min. Obschch., No. 3, PP. 281-290.RussiaCarbonatite
DS1981-0390
1981
Sokolov, S.V.Sokolov, S.V.Shortite, First Find in CarbonatiteDoklady Academy of Science USSR, Earth Science Section., Vol. 247, No. 1-6, PP. 174-177.RussiaRelated Rocks
DS1982-0577
1982
Sokolov, S.V.Sokolov, S.V., et al.Calcite of the Carbonatites of Cherigovka Zone, Western AzovMineral. Zhurn., Vol. 4, No. 4, PP. 66-74.RussiaBlank
DS1984-0698
1984
Sokolov, S.V.Sokolov, S.V.Carbonates of Massifs of Ultramafites, Alkaline Rocks and CarbonatitesGeochemistry International (Geokhimiya)., No. 12, DECEMBER PP. 1840-1857.RussiaCarbonatite
DS1985-0637
1985
Sokolov, S.V.Sokolov, S.V.Carbonates in Ultramafite, Alkali Rock and Carbonatite IntrusionsGeochemistry International, Vol. 22, No. 4, pp. 150-166RussiaCarbonatite, Rare Earth Elements (ree), Geochemistry, Alkaline Rocks
DS1986-0771
1986
Sokolov, S.V.Sokolov, S.V.Thermobarogeochemical study of apatite from rocks of carbonatite complexes.(Russian)Termobarogeokhimiya End. Prot. Vlad., (Russian), pp. 25-32RussiaBlank
DS1988-0026
1988
Sokolov, S.V.Baganov, V.I., Sokolov, S.V.Thermobarometry of ultramafic paragenesis.(Russian)Izd. Nedra Moscow, USSR, (Russian), 149pRussiaBarometry, Mineral composition
DS1989-1428
1989
Sokolov, S.V.Sokolov, S.V.Humite group minerals from carbonatite formations ofalkaline-ultramaficmassifs.(Russian)Zap. Vses. Mineral. O-Va, (Russian), Vol. 118, No. 3, pp. 54-64RussiaCarbonatite, Humite group minerals
DS1989-1429
1989
Sokolov, S.V.Sokolov, S.V.Melilite rocks of massifs of ultramafites, Alkaline rocks andcarbonatites.(Russian)Geochemistry International (Geokhimiya), (Russian), No. 12, December pp. 1683-1693RussiaMelilite, Carbonatite
DS1990-1391
1990
Sokolov, S.V.Sokolov, S.V.Melilite rocks in massifs composed of ultramafites, alkali rocks andcarbonatitesGeochemistry International, Vol. 27, No. 7, pp. 1-10RussiaCarbonatite, Melilites
DS1994-1662
1994
Sokolov, S.V.Sokolov, S.V.Alkali carbonatite complexes and carbonatite formation conditionsGeochemistry International, Vol. 31, No. 6, pp. 46-54.RussiaCarbonatite
DS1994-1663
1994
Sokolov, S.V.Sokolov, S.V.The heterogeneity of carbonatiteDoklady Academy of Sciences USSR, Vol. 327, Oct. pp. 145-148.RussiaCarbonatite, Texture
DS1995-1983
1995
Sokolov, S.V.Veksler, I.V., Sokolov, S.V.Evolution of carbonatite melts in ultramafic alkaline intrusions: evidence from melt inclusions study.Eos, Abstracts, Vol. 76, No. 17, Apr 25, p. S 270.TanzaniaCarbonatite, natroCarbonatite, Deposit -Oldoinyo-Lengai
DS1997-1078
1997
Sokolov, S.V.Sokolov, S.V.Manganese monticellite: the first find in plutonic carbonatitesGeological Association of Canada (GAC) Abstracts, POSTER.RussiaCarbonatite
DS1997-1079
1997
Sokolov, S.V.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
DS1997-1080
1997
Sokolov, S.V.Sokolov, S.V., Veksler, I.V.Mineralogy of melt inclusions in niocalite from carbonatites of the OkaComplex, Canada.Geological Association of Canada (GAC) Abstracts, POSTER.QuebecCarbonatite
DS200512-0529
2005
Sokolov, V.Kidalov, S., Sokolov, V., Shakov, F., Vul, A.Mechanism of the catalytic effect of fullerenes on the graphite-diamond phase.Doklady Physical Chemistry, Vol. 404, 1-3, Sept. pp. 179-181.TechnologyFullerenes
DS1970-0673
1973
Sokolov, V.A.Eremeev, A.N., Sokolov, V.A., Solovov, A.P., Yanitskii, I.N.Application of Helium Surveying to Structural Mapping and Ore Deposit Forecasting.International GEOCHEM. Exploration Symposium 4TH., PP. 183-192.RussiaKimberlite, Geophysics
DS1975-0905
1979
Sokolov, V.N.Afanaseyev, V.P., Kharkiv, A.D., Sokolov, V.N.The Morphology and Morphogenesis of the Garnets in the Kimberlites of Yakutia.Soviet Geology And Geophysics, Vol. 20, No. 3, PP. 65-75.RussiaGenesis
DS1982-0659
1982
Sokolov, V.N.Zinchuk, N.N., Kotelnikov, D.D., Sokolov, V.N.Variation of the Mineral Composition and Structural Features of the Kimberlites of Yakutia During Weathering.Soviet Geology And Geophysics, Vol. 23, No. 2, PP. 36-44.RussiaMineralogy, Geochemistry, Classification, Geomorphology
DS200812-0173
2008
Sokolova, E.Camara, F., Sokolova, E.The structure of bornemanite, a Group III Ti silicate mineral from Lovozero alkaline massif, Kola Peninsula, Russia.Goldschmidt Conference 2008, Abstract p.A131.Russia, Kola PeninsulaMineralogy
DS201012-0358
2010
Sokolova, E.Khomyakov, A.P., Camara, F., Sokolova, E., Abdu, Y., Hawthorne, F.C.Paraershovite, a new mineral species from the Khibin alkaline massif, Kola Peninsula, Russia: description and crystal structure.Canadian Mineralogist, Vol. 48, 2, pp. 291-300.Russia, Kola PeninsulaAlkalic
DS201212-0104
2012
Sokolova, E.Camara, F.,Sokolova, E., Hawthorne, F.C.Kazanskyite, Ba Ti Nb Na3 Ti (Si207) 202 (OH) 2 (H20)4, a group III Ti disilicate mineral from the Khibiny alkaline massif, Kola Peninsula, Russia: description and crystal structure.Mineralogical Magazine, Vol. 76, 3, pp. 473-492.Russia, Kola PeninsulaAlkalic
DS201602-0241
2015
Sokolova, E.Sokolova, E., Abdu, Y., Hawthorne, F.C., Genovese, A., Camara, F., Khomyakov, A.P.From structure topology to chemical composition. XVIII. Titanium silicates: revision of the crystal structure and chemical formula of Betalomonosovite, a group IV TS-block mineral from the Lovozero alkaline massif, Kola Peninsula.The Canadian Mineralogist, Vol. 53, pp. 401-428.Russia, Kola PeninsulaLovozero Massif

Abstract: The crystal structure of betalomonosovite, ideally Na6?4Ti4(Si2O7)2[PO3(OH)][PO2(OH)2]O2(OF), a 5.3331(7), b 14.172(2), c 14.509(2) Å, ? 103.174(2), ? 96.320(2), ? 90.278(2)°, V 1060.7(4) Å3, from the Lovozero alkaline massif, Kola peninsula, Russia, has been refined in the space group PFormula to R = 6.64% using 3379 observed (Fo > 4?F) reflections collected with a single-crystal APEX II ULTRA three-circle diffractometer with a rotating-anode generator (MoK?), multilayer optics, and an APEX-II 4K CCD detector. Electron-microprobe analysis gave the empirical formula (Na5.39Ca0.36Mn0.04Mg0.01)?5.80 (Ti2.77Nb0.48Mg0.29Fe3+0.23Mn0.20Zr0.02Ta0.01)?4(Si2.06O7)2[P1.98O5(OH)3]O2[O0.82F0.65(OH)0.53]?2, Dcalc. = 2.969 g cm?3, Z = 2, calculated on the basis of 26 (O + F) apfu, with H2O determined from structure refinement. The crystal structure of betalomonosovite is characterized by extensive cation and anion disorder: more than 50% of cation sites are partly occupied. The crystal structure of betalomonosovite is a combination of a titanium silicate (TS) block and an intermediate (I) block. The TS block consists of HOH sheets (H-heteropolyhedral, O-octahedral) and exhibits linkage and stereochemistry typical for Group IV (Ti + Mg + Mn = 4 apfu) of the TS-block minerals. The I block is a framework of Na polyhedra and P tetrahedra which ideally gives {Na2?4[PO3(OH)][PO2(OH)2]} pfu. Betalomonosovite is an Na-poor OH-bearing analogue of lomonosovite, Na10Ti4(Si2O7)2(PO4)2O4. In the betalomonosovite structure, there is less Na in the I block and in the TS block when compared to the lomonosovite structure. The OH groups occur mainly in the I block where they coordinate P and Na atoms and in the O sheet of the TS block (minor). The presence of OH groups in the I block and in the TS block is supported by IR spectroscopy and bond-valence calculations on anions. High-resolution TEM of lomonosovite shows the presence of pervasive microstructural intergrowths, accounting for the presence of signals from H2O in the infrared spectrum of anhydrous lomonosovite. More extensive lamellae in betalomonosovite suggest a topotactic reaction from lomonosovite to betalomonosovite.
DS201012-0736
2010
Sokolova, E.L.Sokolova, E.L., Spiridonov, E.M., Vorobev, S.A.Cl bearing lizardite in metamorphosed kimberlites from the Udachnaya Vostochnaya pipe, Yakutia.Petrology, Vol. 18, 2, pp. 126-130.RussiaDeposit - Udachnaya
DS201012-0744
2010
Sokolova, E.L.Spiridonov, E.M., Paulov, L.A., Sokolova, E.L., Vorobev, E.I., Agakhanov, A.A.Chlorine bearing lizardite from metakimberlite of the Udachanaya East pipe.Doklady Earth Sciences, Vol. 431, 1, pp. 403-405.Russia, YakutiaDeposit - Udachnaya East
DS2001-1101
2001
Sokolova, E.V.Sokolova, E.V., Hawthorne, F.C.The crystal chemistry of malinkoite and Lisitsynite from the Khibin a Lovozero Complex, Kola Peninsula.Can. Mineralog., Vol. 39, No. 1, Feb. No.159-69.Russia, Kola PeninsulaMineralogy, alkaline, Deposit - Khibina Lovozero
DS200812-1093
2007
Sokolova, E.Y.Sokolova, E.Y., Varentsov, I.M.Deep array electromagnetic sounding on the Baltic Shield: external excitation model and implications for upper mantle conductivity studies.Tectonophysics, Vol. 445, 1-2, pp. 3-25.Europe, Baltic ShieldGeophysics - magnetics
DS1995-0451
1995
Sokolova, L.S.Duchkov, A.D., Sokolova, L.S.Thermal structure of lithosphere of Siberian PlatformProceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 143-5.Russia, SiberiaGeothermometry, Siberian Platform
DS1997-0294
1997
Sokolova, L.S.Duchkov, A.D., Sokolova, L.S.Thermal structure of the lithosphere of the Siberian PlatformRussian Geology and Geophysics, Vol. 38, No. 2, pp. 528-537.Russia, SiberiaGeothermometry, Mantle structure, tectonics
DS2000-0247
2000
Sokolova, L.S.Duchkov, A.D., Puzankov, Y.M., Sokolova, L.S.Heat flow of kimberlite provinces on cratonsRussian Geology and Geophysics, Vol. 40, No. 7, pp.1078-86.MantleHot spots, Craton - geothermometry
DS201312-0865
2013
Sokolova, T.S.Sokolova, T.S., Dorogokupets, P.I., Litasov, K.D.Self consistent pressure scales based on the equations of state for ruby, diamond, MgO, B2-NaCl, as well as Au, Pt and other metals to 4 Mbar and 3000K.Russian Geology and Geophysics, Vol. 54, pp. 181-199.MantleMelting
DS201502-0055
2015
Sokolova, T.S.Dorogokupets, P.I., Dymshits, A.M., Sokolova, T.S., Danilov, B.S., Litasov, K.D.The equations of state of forsterite, wadsleyite, ringwoodite, akimotoite, Mg2SiO4 perovskite and post perovskite and phase diagram for the Mg2SiO4 system at pressures of up to 130 Gpa.Russian Geology and Geophysics, Vol. 56, 1-2, pp. 172-189.TechnologyPerovskite
DS201805-0978
2016
Sokolova, T.S.Sokolova, T.S., Dorogokupets, P.I., Dymshits, A.M., Danilov, B.S., Konstantin, D.Microsoft excel spreadsheet for calculations of P-V-T relations and thermodynamic properties from equations of state of MgO, diamond and nine other metals as pressure markers in high-pressure and high-temperature experiments.Computers & Geosciences, Vol. 94, 1, pp. 162-169.TechnologyUHP

Abstract: We present Microsoft Excel spreadsheets for calculation of thermodynamic functions and P-V-T properties of MgO, diamond and 9 metals, Al, Cu, Ag, Au, Pt, Nb, Ta, Mo, and W, depending on temperature and volume or temperature and pressure. The spreadsheets include the most common pressure markers used in in situ experiments with diamond anvil cell and multianvil techniques. The calculations are based on the equation of state formalism via the Helmholtz free energy. The program was developed using Visual Basic for Applications in Microsoft Excel and is a time-efficient tool to evaluate volume, pressure and other thermodynamic functions using T-P and T-V data only as input parameters. This application is aimed to solve practical issues of high pressure experiments in geosciences and mineral physics.
DS1980-0321
1980
Sokolova, V.N.Sokolova, V.N.Layered Intrusions of the Imandra Varzuga Zone, Kola PeninsulaInternational Geology Review, Vol. 23, No. 6, pp. 648-58.Russia, Kola PeninsulaTectonics - Layered Intrusion, Mafic
DS1984-0520
1984
Sokolova, V.P.Milashev, V.A., Sokolova, V.P.Megafracturing of the Earth's Crust and the Structural Boundaries of Kimberlite Fields.Soviet Geology And Geophysics, Vol. 25, No. 10, OCTOBER PP. 126-131.RussiaGeotectonics
DS1989-1020
1989
Sokolova, V.P.Milashev, V.A., Sokolova, V.P.Some patterns of distribution and formation of kimberlite fieldsSoviet Geology and Geophysics, Vol. 30, No. 4, pp. 67-74RussiaKimberlite distribution, Tectonics
DS1993-1502
1993
Sokolova, Yu.V.Sokolova, Yu.V., Mironova, N.A.A rheological model for the continental crust derived from metamorphic complexes and crustal xenoliths.Geotectonics, Vol. 26, No. 3, pp. 194-200.RussiaXenoliths, Baikal Rift Zone
DS1998-1378
1998
Sokolovsky, A.K.Sokolovsky, A.K., Serokurov, Yu.N., Kalmykov, V.D.System analysis of remote sensing dat a on structural control of diamondiferous areas.7th International Kimberlite Conference Abstract, pp. 838-40.RussiaRemote sensing, Tectonics, structure
DS1996-1347
1996
Sokolv, B.A.Sokolv, B.A., Piyp, V.B., Yefimova, Ye. A.Basement structure in the centre of the East European Craton, as inferred from seismic data.Doklady Academy of Sciences, Vol. 336, pp. 72-78.Russia, Arkangelsk, EuropeBasement -depth, Geophysics -seismics
DS2003-0287
2003
Sokouris, D.Corti, G., Bonini, M., Continelli, S., Innocenti, F., Manetti, P., Sokouris, D.Analogue modelling of continental extension: a review focused on the relations betweenEarth Science Reviews, Vol. 63, No. 3-4, pp. 169-247.MantleMagmatism, tectonics
DS200412-0373
2003
Sokouris, D.Corti, G., Bonini, M., Continelli, S., Innocenti, F., Manetti, P., Sokouris, D.Analogue modelling of continental extension: a review focused on the relations between the patterns of deformation and the preseEarth Science Reviews, Vol. 63, no. 3-4, pp. 169-247.MantleMagmatism, tectonics
DS200412-0374
2004
Sokoutis, D.Corti, G., Bonini, M., Sokoutis, D., innocenti, F., Manetti, P., Cloetingh, S., Mulugeta, G.Continental rift architecture and patterns of magma migration: a dynamic analysis based on centrifuge models.Tectonics, Vol. 23, 2, TC2012 10.1029/2003 TC001561MantleGeodynamics
DS200612-1437
2006
Sokoutis, D.Triel, C., Brun, J=P., Sokoutis, D.Extension of thickened crust and hot lithosphere: inferences from laboratory modeling.Tectonics, Vol. 25, 1, TC1005TechnologyTectonics, mantle
DS200712-1012
2007
Sokoutis, D.Sokoutis, D., Corti, G., Bonin, M., Brun, J.P., Cloetingh, S., Maudit, T., Manetti, P.Modelling the extension of heterogeneous hot lithosphere.Tectonophysics, Vol. 444, pp. 63-79.MantleRheology, back arc extension
DS201012-0461
2010
Sokoutis, D.Luth, S., Willingshofer, E., Sokoutis, D., Cloetingh, S.Analogie modelling of continental collision: influence of plate coupling on mantle lithosphere subduction, crustal deformation and surface topography.Tectonophysics, Vol. 484, pp. 87-102.MantleTectonics
DS201412-0976
2013
Sokoutis, D.Willingshofer, E., Sokoutis, D., Beekman, F., Cloetingh, S.Subduction and deformation of the continental lithosphere in response to plate and crust-mantle coupling.Geology, Vol. 41, pp. 1239-1242.MantleSubduction
DS201901-0010
2018
Sokoutis, D.Brun, J-P., Sokoutis, D., Tirel, C., Gueydan, F., Beslier, M-O.Crustal versus mantle core complexes.Tectonophysics, Vol. 746, pp. 22-45.Mantlegeodynamics

Abstract: Deep crustal and mantle rocks are exhumed in core complex mode of extension in three types of structures: metamorphic core complexes, oceanic core complexes and magma poor passive margins. Using available analogue and numerical models and their comparison with natural examples, the present paper reviews the mechanical processes involved in these different types of extensional setting. Three main aspects are considered: i) the primary role of lithosphere rheology, ii) the lithosphere-scale patterns of progressive deformation that lead to the exhumation of deep metamorphic or mantle rocks and iii) the initiation and development of detachment zones. Crustal core complexes develop in continental lithospheres whose Moho temperature is higher than 750 °C with “upper crust-dominated” strength profiles. Contrary to what is commonly believed, it is argued from analogue and numerical models that detachments that accommodate exhumation of core complexes do not initiate at the onset of extension but in the course of progressive extension when the exhuming ductile crust reaches the surface. In models, convex upward detachments result from a rolling hinge process. Mantle core complexes develop in either the oceanic lithosphere, at slow and ultra-slow spreading ridges, or in continental lithospheres, whose initial Moho temperature is lower than 750 °C, with “sub-Moho mantle-dominated” strength profiles. It is argued that the mechanism of mantle exhumation at passive margins is a nearly symmetrical necking process at lithosphere scale without major and permanent detachment, except if strong strain localization could occur in the lithosphere mantle. Distributed crustal extension, by upper crust faulting above a décollement along the ductile crust increases toward the rift axis up to crustal breakup. Mantle rocks exhume in the zone of crustal breakup accommodated by conjugate mantle shear zones that migrate with the rift axis, during increasing extension.
DS1999-0355
1999
Sol, S.Kay, I., Sol, S., Francism D.Shear wave splitting observations in the Archean Craton of westernSuperior.Geophysical Research Letters, Vol. 26, No. 17, Sept. 1, pp. 2669-72.Ontario, ManitobaCraton, Geophysics
DS2002-0824
2002
Sol, S.Kendall, J.M., Sol, S., Thomson, C.J., White, D.J., Asudeh, I., Snell, C.S.Seismic heterogeneity and anisotropy in the western Superior Province, Canada:Geological Society of London Special Publication, No. 199, pp. 27-44.Northwest Territories, Ontario, Manitoba,SaskatchewanGeophysics - seismics
DS2002-1523
2002
Sol, S.Sol, S., Thomson, C.J., Kendall, J.M., White, D., Van Decan, J.C., Asudeh, I.Seismic tomographic images of the cratonic upper mantle beneath the Western SuperiorPhysics of the Earth and Planetary Letters, Vol. 134, 1-2, pp. 53-69.Manitoba, Saskatchewan, Alberta, Northwest TerritoriesGeophysics - seismics, subduction
DS200712-0327
2007
Sol, S.Frederickson, A.W., Miong, S.K., Darbyshire, F.A., Eaton, D.W., Rondenay, S., Sol, S.Lithospheric variations across the Superior Province, Ontario Canada: evidence from tomographic wave splitting.Journal of Geophysical Research, Vol. 112, B7, B07318.Canada, OntarioGeophysics - seismics
DS202205-0703
2021
Solak, N.Mansoor, M., Mansoor, M., Mansoor, M., Aksoy, A., Seyhan, S.N., Yildirim, B., Tahiri, A., Solak, N., Kazmanli, K., Er, Z., Czelej, K., Urgen, M.Ab-nitro calculation of point defect equilibria during heat treatment: nitrogen, hydrogen, and silicon doped diamond.Researchgate preprint Istanbul Technical University , 18p. PdfGlobaldiamond morphology

Abstract: Point defects are responsible for a wide range of optoelectronic properties in materials, making it crucial to engineer their concentrations for novel materials design. However, considering the plethora of defects in co-doped semiconducting and dielectric materials and the dependence of defect formation energies on heat treatment parameters, process design based on an experimental trial and error approach is not an efficient strategy. This makes it necessary to explore computational pathways for predicting defect equilibria during heat treatments. The accumulated experimental knowledge on defect transformations in diamond is unparalleled. Therefore, diamond is an excellent material for benchmarking computational approaches. By considering nitrogen, hydrogen, and silicon doped diamond as a model system, we have investigated the pressure dependence of defect formation energies and calculated the defect equilibria during heat treatment of diamond through ab-initio calculations. We have plotted monolithic-Kröger-Vink diagrams for various defects, representing defect concentrations based on process parameters, such as temperature and partial pressure of gases used during heat treatments of diamond. The method demonstrated predicts the majority of experimental data, such as nitrogen aggregation path leading towards the formation of the B center, annealing of the B, H3, N3, and NVHx centers at ultra high temperatures, the thermal stability of the SiV center, and temperature dependence of NV concentration. We demonstrate the possibility of designing heat treatments for a wide range of semiconducting and dielectric materials by using a relatively inexpensive yet robust first principles approach, significantly accelerating defect engineering and high-throughput novel materials design.
DS201212-0687
2012
Solano, J.M.S.Solano, J.M.S., Jackson, M.D., Sparks, R.S.J., Blundy, J.D., Annen, C.Melt segregation in deep crustal hot zones: a mechanism for chemical differentiation, crustal assimilation and the formation of evolved magmas.Journal of Petrology, Vol. 53, 10, pp. 1999-2026.MantleHotspots, magmatism
DS1998-0171
1998
Solar, G.S.Brown, M., Solar, G.S.Shear zone systems and melts: feedback relations and self organization in orogenic beltsJournal of Struct. Geol, Vol. 20, No. 2-3, Feb.1, pp. 211-228GlobalTectonics, Orogeny, subduction
DS1985-0293
1985
Solberg, T.N.Hogarth, D.D., Hartree, R., Loop, J., Solberg, T.N.Rare Earth Element Minerals in Four Carbonatites Near Gatineau QuebecAmerican Mineralogist, Vol. 70, pp. 1135-1142QuebecCarbonatite, Rare Earths
DS200512-1023
2005
Soldati, G.Soldati, G., Boschi, L.The resolution of whole Earth seismic tomographic models.Geophysical Journal International, Vol. 161, 1, p. 143.MantleGeophysics - seismics
DS201212-0688
2012
Soldati, G.Soldati, G., Boschi, L., Forte, A.M.Tomography of core mantle boundary and lowermost mantle coupled by geodynamics.Geophysical Journal International, Vol. 189, 2, pp. 730-746.MantleGeodynamics
DS201312-0866
2013
Soldati, G.Soldati, G., Koelemeijer, P., Boschi, L., Deuss, A.Constraints on core-mantle boundary topography from normal mode splitting.Geochemistry, Geophysics, Geosystems: G3, Vol. 14, 5, pp. 1333-1342.MantleHeterogeneity
DS1993-1503
1993
Soler, P.Soler, P.The Andean mineralizations revisited: orogenesis, subduction -related calc-alkaline magmatism and metallogenesis in the Central Peruvian AndesProceedings of the Second Biennial SGA Meeting, held Granada Sept., pp. 771-774PeruSubduction, Alkaline rocks
DS1996-0624
1996
Soler, P.Herail, G., Oller, J., Soler, P.Strike slip faulting, thrusting and related basins in the Cenozoic evolution of the southern branch OroclineTectonophysics, Vol. 259, No. 1-3, June 30, pp. 201-212BoliviaTectonics, Faulting, thrusting
DS1996-0674
1996
Soler, P.Jaillard, E., Soler, P.Cretaceous to early Paleocene tectonic evolution of the northern Central Andes 0-10 and its relations geodynaM.Tectonophysics, Vol. 259, No. 1-3, June 30, pp. 41-54Andes, Cordillera, Bolivia, ArgentinaGeodynamics, Tectonics
DS200512-0137
2005
Soler, P.Carlier, G., Lorand, J.P., Liegeois, J.P., Fornari, M., Soler, P., Carlotto, V., Cardenas, J.Potassic ultrapotassic mafic rocks delineate two lithospheric mantle blocks beneath southern Peruvian Altiplano.Geology, Vol. 33, 7, July, pp. 601-604.South America, PeruLamproite
DS200712-1013
2007
Soleva, L.V.Soleva, L.V.Reworking of the lithospheric mantle of the Siberian Craton by reduced fluids in the middle Paleozoic kimberlite event: geochemical consequences.Doklady Earth Sciences, Vol. 413, 2, pp. 238-243.RussiaGeochemistry
DS200912-0027
2009
Solferino, G.Bagdassarov, N., Solferino, G., Golabek, G.J., Schmidt, M.W.Centrifuge assisted percolation of Fe-S melts in partially molten peridotite: time constraints for planetary core formation.Earth and Planetary Science Letters, Vol. 288, 1-2, pp. 84-95.MantleMelting
DS201212-0626
2012
Solferino, G.Schmidt, M.W., Forien, M., Solferino, G., Bagdassarov, N.Setting and compaction of olivine in basaltic magmas: an experimental study on the time scales of cumulate formation.Contributions to Mineralogy and Petrology, Vol. 164, 6, pp. 959-976.MantleMagmatism
DS201412-0321
2014
Solgadi, F.Groulier, P.A., Andre-Mayer, A.S., Ohnenstetter, D., Zeh, A., Moukhsil, A., Solgadi, F., El Basbas, A.Petrology, geochemistry and age of the Crevier alkaline intrusion.GAC-MAC Annual Meeting May, abstract 1p.Canada, QuebecAlkalic
DS201512-1971
2015
Solgadi, F.Solgadi, F., Groulier, P.A, Moukhsil, A., Ohnenstetter, D., Andre-Mayer, A.S., Zeh, A.Nb-Ta-REE mineralization associated with the Crevier alkaline intrusion.Symposium on critical and strategic materials, British Columbia Geological Survey Paper 2015-3, held Nov. 13-14, pp. 69-74.Canada, QuebecAlkalic

Abstract: The Crevier alkaline intrusion is in the Grenville Province, north of the Lac Saint-Jean region of Québec (Fig. 1). It covers ~25 km2 (Bergeron, 1980) and intrudes charnockitic suites in the allochthon belt defi ned by Rivers et al. (1989). This intrusion has a U-Pb zircon age of 957.5 ± 2.9 Ma (Groulier et al., 2014) and is oriented N320°, along the axis of crustal weakness known as the Waswanipi-Saguenay corridor (Bernier and Moorhead, 2000). This corridor is related to the Saguenay graben, which hosts the Saint-Honoré (Niobec) Nb-Ta-REE deposit and Montviel REE deposit. The age of the Saint-Honoré carbonatite was estimated at 584 to 650 Ma (K-Ar whole rock; Vallée and Dubuc, 1970; Boily and Gosselin, 2004). The Montviel intrusion has a U-Pb zircon age of 1894 ± 3.5 Ma (David et al., 2006; Goutier, 2006). These crystallization ages are very different and cannot be related to a single event for the injection of alkaline intrusions. As mapped by Bergeron (1980), the Crevier alkaline intrusion is broadly composed of syenite and carbonatite rocks (Fig. 2). The Nb- Ta mineralization consists of pyrochlore hosted by a nepheline syenite dike swarm in the centre of the intrusion. The highest REE concentrations, up to 729 ppm La and 1465 ppm Ce, are at the edge of the Crevier alkaline intrusion (Niotaz sud showing; Fig. 2).
DS1993-1504
1993
Solheim, L.P.Solheim, L.P., Pelthier, W.R.Mantle phase Transitions and layered convectionCanadian Journal of Earth Sciences, Vol. 30, pp. 881-92.MantleConvection model
DS1993-1505
1993
Solheim, L.P.Solheim, L.P., Peltier, W.R.Mantle phase transitions and layered convectionCanadian Journal of Earth Sciences, Vol. 30, No. 5, May pp. 881-892GlobalLayered intrusions, Mantle, Numerical simulations
DS1996-1348
1996
Solheim, L.P.Solheim, L.P.Episodic mantle convectionGlobal Tectonics and Metallogeny, Vol. 6, No. 1, pp. 25-33MantleHeat flow, Convection
DS200412-1693
2004
Solidilov, L.N.Ross, A.R., Thybo, H., Solidilov, L.N.Reflection seismic profiles of the core mantle boundary.Journal of Geophysical Research, Vol. 109, B8 August 11 10.1029/2003 JB002515MantleGeophysics - seismics
DS200512-0912
2004
Solidilov, L.N.Ross, A.R., Thybo, H., Solidilov, L.N.Reflection seismic profiles of the core-mantle boundary.Journal of Geophysical Research, Vol. 109, 8, B08303 DOI 10.1029/200 3JB002515.MantleGeophysics - seismics
DS200712-0001
2007
Soliman, K.S.Abdelrahman, E.M., Abo-Ezz, E.R., Soliman, K.S., El-Araby, T.M., Essa, K.S.A least squares window curve method for interpretation of magnetic anomalies caused by dipping dikes.Pure and Applied Geophysics, Vol. 164, 5, May pp. 1027-1044.CanadaGeophysics - airborne magnetics
DS1970-0194
1970
Solin, S.A.Solin, S.A., Ramdas, A.K.Raman Spectrum of DiamondPhys. Rev. B., Vol. 1, No. 4, Feb. 15, pp. 1687-1698GlobalSpectroscopy, Diamond Morphology
DS1992-1451
1992
Soller, D.R.Soller, D.R.Text and references to accompany map showing the thickeness and character of Quaternary sediments in the glaciated United States east of the RockyMountainsUnited States Geological Survey (USGS) Bulletin, No. 1921, 54p. $ 3.25GlobalGeomorphology, Glacial sediments
DS1993-1506
1993
Soller, D.R.Soller, D.R., Moy, W-S.Preliminary digital quaternary geol. map for IndianaUnited States Geological Survey (USGS) Open File, No. 93-0268-A, 5p. $ 1.50 plus disc $ 40.00IndianaGeomorphology, Computer digital data
DS1998-1379
1998
Soller, D.R.Soller, D.R.Map showing the thickness and character of Quaternary sediments in the glaciated USA east of Rocky Mtns...United States Geological Survey (USGS), Map I 1970-B, 1 1m. $ 4.00GlobalGeomorphology - glacial sediments
DS2000-0105
2000
SolliBraathen, A., Nordgulen, Osmundsen, Andersen, SolliDevonian, orogen parallel, opposed extension in the central Norwegian Caledonides.Geology, Vol. 28, No. 7, July, pp. 615-18.NorwayBaltica, Laurentia, Tectonics
DS200912-0634
2008
Solli, A.Robinson, P., Solli, A., Engvik, A., Erambert, M., Bingen, B., Schiellerup, H., Njange, F.Solid solution between potassic obertitie and potassic fluoro magnesio arfvedsonite in a silica rich lamproite from northeast Mozambique.European Journal of Mineralogy, Vol. 20, 6, pp. 1011-1018.Africa, MozambiqueLamproite
DS1997-1081
1997
Sollner, F.Sollner, F., Trouw, R.A.J.The Andrelandia depositional cycle: a post trans- amazonic sequence ...evidence uranium-lead (U-Pb) (U-Pb) dating of zircons.Journal of South American Earth Sciences, Vol. 10, No. 1, pp, 21-28Brazil, Minas GeraisSao Francisco Craton, Geochronology
DS2000-0914
2000
Sollner, F.Sollner, F., Miller, H., Herve, M.An early Cambrian granodiorite age from Pre-Andean basement of Tierra del Fuego: the missing link...Journal of South American Earth Sciences, Vol. 13, No. 3, July pp. 163-77.South America, AntarcticaTectonics, Gondwanaland
DS1988-0714
1988
Solnick-Legg, H.Tzeng, Y., Kung, P.J., Zee, R., Legg, K., Solnick-Legg, H., BurnsSpiral hollow cathode plasma assisted diamond depositionAppl. Phys. Letters, Vol. 53, No. 23, pp. 2326-2327GlobalDiamond coatings, Diamond applications
DS2003-1013
2003
Solodilov, L.Nielsen, L., Thybo, H., Morozov, I.B., Smithson, S.B., Solodilov, L.Teleseismic Pn arrivals influence of mantle velocity gradient and crustal scatteringGeophysical Journal International, Vol. 152, No. 2, pp. F1-F6.MantleGeophysics - seismics
DS200712-0576
2006
Solodilov, L.Kostyuchenko, S., Sapozhnikov, R., Egorkin, A., Gee, D.G., Berzin, R., Solodilov, L.Crustal structure and tectonic model of northeastern Baltica, based on deep seismic and potential field data.Geological Society of London Memoir, No. 32, pp. 521-540.Europe, Baltic ShieldTectonics, geophysics
DS1996-1083
1996
Solodilov, L.N.Pavlenkova, N.I., Pavlenkova, G.A., Solodilov, L.N.High velocities in the uppermost mantle of the Siberian cratonTectonophysics, Vol. 262, pp. 51-65.Russia, SiberiaGeophysics - seismics, Mantle, Siberian craton
DS1998-1467
1998
SolodovTitkov, S., Gorshkov, Vinokov, Bershov, Solodov, SivtsovCarbonado from Yakutian diamond deposits (Russia): microinclusions, impurities and paragenetic centres.7th International Kimberlite Conference Abstract, pp. 914-6.Russia, YakutiaCarbonado, Deposit - Udachnaya
DS2001-1160
2001
SolodovTitkov, S.V., Gorshkov, Vinokurov, Bershov, SolodovGeochemistry and genesis of carbonado from Yakutian diamond depositsGeochemistry International, Vol. 39, No. 3, pp. 228-36.Russia, YakutiaMicroinclusions, Carbonado
DS1985-0638
1985
Solodov, N.A.Solodov, N.A.Carbonatite Formations and their Rare Metal Metallogeny.(russian)Redk. Elem.(Russian), Vol. 18, pp. 102-113RussiaCarbonatite, Rare Earths
DS200612-1429
2006
SolodovaTitkov, S.V., Gorshkov, A.I., Solodova, Ryabchikov, Magazina, Sivtsov, Gasanov, Sedova, SamosorovMineral Micro inclusions in cubic diamonds from the Yakutian deposits based on analytical electron microscopy data.Doklady Earth Sciences, Vol. 410, no. 7 July-August, pp. 1106-1108.Russia, YakutiaDiamond inclusions
DS1985-0208
1985
Solodova, I.P.Gafitullina, D.S., Solodova, I.P., Khaidarov, A.A.Trace Elements in Diamonds.(russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 284, No. 6, pp. 1464-1466RussiaDiamond Morphology
DS201112-0983
2011
Solodova, Y.Solodova, Y.Mineralogical characteristics of diamonds from the Nurbinskaya pipe, Yakutian diamond bearing province.GIA International Symposium 2011, Gems & Gemology, Summer poster abstract p. 134-5.Russia, YakutiaDiamond morphology
DS1985-0233
1985
Solodova, Y.P.Gifitullina, D.S., Solodova, Y.P., Khaydarov, A.A.Impurities in Diamonds of Fibrous Structure.*rusDoklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 284, No. 6, pp. 1464-1466RussiaCrystallography, Diamond Morphology
DS1985-0418
1985
Solodova, Y.P.Martovitskiy, V.P., Solodova, Y.P.The internal structure and morphology of penetrating twins ofnaturaldiamond.(Russian)Mineral. Zhurn., (Russian), Vol. 7, No. 5, pp. 40-50RussiaDiamond Morphology
DS200712-0728
2007
Solodova, Y.P.Mineeva, R.M., Speransky, A.V., Titkov, S.V., Solodova, Y.P., Samosorov, G.G.Paramagnetic N1 centre in plastically deformed and differently colored crystals of natural diamond.Doklady Earth Sciences, Vol. 415, 5, pp. 782-785.TechnologyDiamond morphology
DS200712-1014
2006
Solodova, Y.P.Solodova, Y.P., Sedova, E.A., Samosorov, G.G., Kurbatov, K.K.Comparative investigation of diamonds from various pipes in the Malaya Botuobiya and Daldyn Alakit areas, Siberia.Gems & Gemology, 4th International Symposium abstracts, Fall 2006, p.141-2. abstract onlyRussiaDiamond morphology
DS200712-1084
2006
Solodova, Y.P.Titkov, S.V., Solodova, Y.P., Gorshkov, A.I., Magaina, L.O., Sivtsov, A.V., Sedova, E.A., Gasanov, SamosorovInclusions in white gray diamonds of cubic habit from Siberia.Gems & Gemology, 4th International Symposium abstracts, Fall 2006, p.127-8. abstract onlyRussiaDiamond morphology
DS1987-0233
1987
Solodova, Yu.P.Gafitullina, D.S., Solodova, Yu.P., Khaydarov, A.A.Impurities in diamonds with fibrous textureDoklady Academy of Science USSR, Earth Science Section, Vol. 284, No. 5, Publishing July 1987, pp. 163-166RussiaMineralogy
DS1988-0420
1988
Solodova, Yu.P.Lobanov, F.I., Solodova, Yu.P., Tatyanina, N.A.Effect of impurity induced defects on the morphology of type Idiamonds (according to Yu.L. Orlov).(Russian)Izv. Vyssch. Uchebn. Zaved., Geol. Razved., (Russian), No. 6, pp. 31-36RussiaDiamond morphology, Type 1
DS201502-0114
2015
Solodova, Yu.P.Titkov, S.V., Shiryaev, A.A., Zudina, N.N., Zudin, N.G., Solodova, Yu.P.Defects in cubic diamonds from the placers in the northeastern Siberian platform: results of IR microspectrometry.Russian Geology and Geophysics, Vol. 56, 1, pp. 354-365.RussiaDiamond morphology
DS1989-1685
1989
Sololeva, S.V.Zinchuk, N.N., Sololeva, S.V., Kotelnikov, D.D., Antonyuk, B.P.Characteristics of phyllosilicates from Kimberlites and their country rocks in the zones of active exposure to traprock magmatism (Yakutia).(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 305, No. 5, pp. 1199-1202RussiaAlteration
DS2001-1102
2001
Solomatov, V.S.Solomatov, V.S.Grain size dependent viscosity convection and the thermal evolution of theEarth.Earth and Planetary Science Letters, Vol. 191, No. 3-4, pp. 203-12.MantleGeothermometry, Convection
DS2002-1524
2002
Solomatov, V.S.Solomatov, V.S., ElKhozondar, R., Tikare, V.Grain size in the lower mantle: constraints from numerical modeling of grain growth in two phase systemsPhysics of the Earth and Planetary Interiors, Vol.129, 3-4, pp.265-82.MantleExperimental petrology
DS200412-1873
2004
Solomatov, V.S.Solomatov, V.S.Initiation of subduction by small scale convection.Journal of Geophysical Research, Vol. 109, B1, 10.1029/2003 JB002628MantleSubduction - not specific to diamonds
DS200812-1094
2008
Solomatov, V.S.Solomatov, V.S., Reese, C.C.Grain size variations in the Earth's mantle and the evolution of primordial heterogeneities.Journal of Geophysical Research, Vol. 113, B7 B7408.MantleGeochemistry
DS201606-1118
2016
Solomatova, N.V.Solomatova, N.V., Jackson, J.M., Sturhahn, W., Wicks, J.K., Zhao, J., Toellner, T.S., Kalkan, B., Steinhardt, W.M.Equation of state and spin crossover of ( Mg,Fe)O at high pressure, with implications for explaining topographic relief at the core mantle boundary.American Mineralogist, Vol. 101, 5, pp. 1084-1093.MantleCore, mantle boundary
DS201703-0442
2017
Solomnikova, A.V.Zubkov, V.I., Solomnikova, A.V., Post, J.E., Gaillou, E., Butler, J.E.Characterization of electronic properties of natural type 11b diamonds.Diamond and Related Materials, Vol. 72, pp. 87-93.TechnologyDiamonds - type 11b

Abstract: Precision admittance spectroscopy measurements were carried out over wide temperature and frequency ranges for a set of natural single crystal type IIb diamond samples. Peaks of conductance spectra vs. temperature and frequency were used to compute the Arrhenius plots, and activation energies were derived from these plots. The capacitance-voltage profiling was used to estimate the majority charge carrier concentration and its distribution into depth of the samples. Apparent activation energies between 315 and 325 meV and the capture cross section of about 10? 13 cm2 were found for samples with uncompensated boron concentrations in the range of 1 to 5 × 1016 cm? 3 (0.06-0.3 ppm). The obtained boron concentrations are in good coincidence with FTIR results for the samples. Also, a reason for the difference between the observed admittance activation energy and the previously reported ionization energy for the acceptor boron in diamond (0.37 eV) is proposed.
DS1995-0531
1995
Solomon, G.B.Fenteng, J.A., Asabere, R.K., Solomon, G.B.Integrated reclamation planning of disconfigured Lands cape after surface mining operations at Ghana (GCD.Singhal, Mine Planning, pp. 657-665.GhanaEnvironment, dumps, Reclamation
DS1991-0625
1991
Solomon, M.Gulson, B.L., Solomon, M., Vaasjoki, M., Both, R.Tasmania adrift?Australian Journal of Earth Sciences, Vol. 38, pp. 249-250TasmaniaTectonics, Structure
DS1994-1664
1994
Solomon, M.Solomon, M., Groves, D.I.The geology and origins of Australia's mineral depositsOxford University Press, 864pAustraliaMineral deposits, Book -ad
DS1994-1665
1994
Solomon, M.Solomon, M., Groves, D.I., Jaques, A.The geology and origin of Australia's mineral depositsOxford Press, 960p. approx. $ 410.00AustraliaBook -table of contents, Deposits
DS1995-0211
1995
Solomon, M.Bristow, J., Moloi, N., Solomon, M., Rocha, J.Minerals and mining in South Africa: past, present and futureProspectors and Developers Association of Canada (PDAC) Reprint, 8pSouth AfricaEconomics, Mining industry, legal
DS1995-1800
1995
Solomon, M.H.Solomon, M.H., Van Schahlkwyk, J.Privitization in the minerals sector in South AfricaRaw Materials Report, Vol. 11, No. 3, pp. 14-24.South AfricaEconomics, legal privitization, Alexcor
DS1995-1801
1995
Solomon, M.H.Solomon, M.H., Von Schalkwyk, J.Privatization in the minerals sector in South AfricaRaw Materials Report, Vol. 11, No. 3, pp. 14-24South AfricaLegal, Economics -mineral sectors Alexcor
DS1997-1082
1997
Solomon, M.H.Solomon, M.H.South African minerals industry: implications of downscalingJournal of Mineral Policy, Business and Environment, Vol. 12, No. 4, pp. 21-30South AfricaEnvironment, closures, Gold, prices, economics, discoveries, success
DS1997-1083
1997
Solomon, M.H.Solomon, M.H.Small and mid-scale mining in South Africa: beyond the RhetoricJournal of Mineral Policy, Vol. 12, No. 3, pp. 23-30South AfricaMining - classification/ numbers, Economics
DS2002-1732
2002
Solomon, S.Wolfe, C.J., Bjarnson, I.T., VanDecarm J.C., Solomon, S.Assessing the depth resolution of tomographic models of upper mantle structure beneath Iceland.Geophysical Research Letters, Vol.29, 2, pp. 21-4.IcelandTomography, Geophysics - seismics
DS1990-1392
1990
Solomon, S.C.Solomon, S.C.New images for old faultsNature, Vol. 344, No. 6269, April 26, pp. 816-817GlobalStructure, Geophysics -seismics MCS
DS1992-1452
1992
Solomon, S.C.Solomon, S.C.The structure of the Mid Ocean RidgesAnnual Review of Earth and Planetary Science, Vol. 20, pp. 329-64.MantleMagmatism, convection
DS2002-1145
2002
Solomon, S.C.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
Solomon, S.C.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
DS2002-1457
2002
Solomon, S.C.Shen, Y., Solomon, S.C., Bjarnason, Nolet, MorganSeismic evidence for a tilted mantle plume and north south mantle flow beneath IcelandEarth and Planetary Science Letters, Vol.197,3-4,pp.261-77.IcelandTransition zones, discontinuities, convection
DS200612-1564
2006
Solomon, S.C.Yang, T., Shen, Y., Van der lee, S., Solomon, S.C., Hung, S.H.Upper mantle structure beneath the Azores hotspot from finite frequency seismic tomography.Earth and Planetary Science Letters, Vol. 250, 1-2, pp. 11-26.AzoresGeophysics - seismics
DS1960-0447
1964
Solomonidina, N.L.Elyanov, A.A., Petrova, M.G., Solomonidina, N.L.The First Discovery of Kimberlites in the East of the Aldanshield.Izv. Vses. Ucheb. Zaved. Ser. Geol., No. 8, . PP. 123-124.RussiaBlank
DS1991-1629
1991
Solomovich, L.I.Solomovich, L.I., Trifonov, B.A.The association of Rapakivi granites, alkaline rocks, and carbonatites In the Tien ShanInternational Geology Review, Vol. 33, No. 2, Feb. pp. 191-202RussiaCarbonatite, Tien Shan
DS1993-1507
1993
Solopanov, A.T.Solopanov, A.T., Chebkasov, R.V.Problems of environmental control when mining diamond deposits in westernYakutia.Diamonds of Yakutia, Russia, Extended Abstracts, Volume in English $ 115.00, pp. 163-164.Russia, YakutiaMining, Environmental
DS201509-0429
2015
Solopova, N.Spivak, A., Solopova, N., Dubrovinsky, L., Litvin, Y.Melting relations of multicompnent carbonate MgCO3-FeCO3-CaCO3-Na2CO3 system at 12-26 Gpa: application to deeper mantle diamond formation.Physics and Chemistry of Minerals, DOI 10.1007/ s00269-015-0765-6MantleMelting

Abstract: Carbonatic components of parental melts of the deeper mantle diamonds are inferred from their primary inclusions of (Mg, Fe, Ca, Na)-carbonate minerals trapped at PT conditions of the Earth’s transition zone and lower mantle. PT phase diagrams of MgCO3-FeCO3-CaCO3-Na2CO3 system and its ternary MgCO3-FeCO3-Na2CO3 boundary join were studied at pressures between 12 and 24 GPa and high temperatures. Experimental data point to eutectic solidus phase relations and indicate liquidus boundaries for completely miscible (Mg, Fe, Ca, Na)- and (Mg, Fe, Ca)-carbonate melts. PT fields for partial carbonate melts associated with (Mg, Fe)-, (Ca, Fe, Na)-, and (Na2Ca, Na2Fe)-carbonate solid solution phases are determined. Effective nucleation and mass crystallization of deeper mantle diamonds are realized in multicomponent (Mg, Fe, Ca, Na)-carbonatite-carbon melts at 18 and 26 GPa. The multicomponent carbonate systems were melted at temperatures that are lower than the geothermal ones. This gives an evidence for generation of diamond-parental carbonatite melts and formation of diamonds at the PT conditions of transition zone and lower mantle.
DS201601-0046
2015
Solopova, N.Spivak, A., Solopova, N., Dubrovinsky, L., Litvin, Y.Melting relations of multicomponent carbonate MgCO3-FeCO3-CaCO3-Na2CO3 system at 12-26 Gpa: application to deeper mantle diamond formation.Physics and Chemistry of Minerals, Vol. 42, pp. 817-824.MantleCarbonatite, diamond genesis

Abstract: Carbonatic components of parental melts of the deeper mantle diamonds are inferred from their primary inclusions of (Mg, Fe, Ca, Na)-carbonate minerals trapped at PT conditions of the Earth’s transition zone and lower mantle. PT phase diagrams of MgCO3-FeCO3-CaCO3-Na2CO3 system and its ternary MgCO3-FeCO3-Na2CO3 boundary join were studied at pressures between 12 and 24 GPa and high temperatures. Experimental data point to eutectic solidus phase relations and indicate liquidus boundaries for completely miscible (Mg, Fe, Ca, Na)- and (Mg, Fe, Ca)-carbonate melts. PT fields for partial carbonate melts associated with (Mg, Fe)-, (Ca, Fe, Na)-, and (Na2Ca, Na2Fe)-carbonate solid solution phases are determined. Effective nucleation and mass crystallization of deeper mantle diamonds are realized in multicomponent (Mg, Fe, Ca, Na)-carbonatite-carbon melts at 18 and 26 GPa. The multicomponent carbonate systems were melted at temperatures that are lower than the geothermal ones. This gives an evidence for generation of diamond-parental carbonatite melts and formation of diamonds at the PT conditions of transition zone and lower mantle.
DS200912-0448
2009
Solopova, N.A.Livin, Yu.AQ., Spivak, A.V., Solopova, N.A., Litvin, V.Yu., Bobrov, A.V.Physicochemical factors of diamond and graphite formation in carbonatite melts on experimental grounds.alkaline09.narod.ru ENGLISH, May 10, 2p. abstractTechnologyExperimental melt
DS201412-0865
2014
Solopova, N.A.Solopova, N.A.Crystallization of diamond in carbonate melts in experiments under 5.5 - 84.0 Gpa pressure. IN RUSSIANThesis, Lomonosov State University and Institute of Experimental Mineralogy ** IN Russian ( courtesy of Kaminsky), 25p. Available pdfTechnologyDiamond crystallography
DS201412-0866
2013
Solopova, N.A.Solopova, N.A., Litvin, Yu.A., Spivak, A.V., Dubrovinskaia, N.A., Dubrovinsky, L.S., Urusov, V.S.The phase diagram of Na carbonate, an alkaline component of the growth medium of ultradeep diamonds.Doklady Earth Sciences, Vol. 451, 1, pp. 1106-1109.TechnologyUHP
DS201511-1882
2015
Solopova, N.A.Spivak, A.V., Solopova, N.A., Dubrovinsky, L.S., Litvin, Yu.A.The system MgCO3-FeCO3-CaCO3-Na2CO3 at 12-23 Gpa: phase relations and significance for the genesis of ultradeep diamonds.Doklady Earth Sciences, Vol. 464, 1, pp. 946-950.MantleDiamond genesis

Abstract: Physical-chemical experimental studies at 12-23 GPa of phase relationships within four-members carbonate system MgCO3-FeCO3-CaCO3-Na2CO3 and its marginal system MgCO3-FeCO3-Na2CO3 were carried out. The systems are quite representative for a set of carbonate phases from inclusions in diamonds within transitional zone and lower mantle. PT-phase diagrams of multicomponent carbonate systems are suggested. PT parameters of boundaries of their eutectic melting (solidus), complete melting (liquids) are established. These boundaries define area of partial melting. Carbonate melts are stable, completely mixable, and effective solvents of elemental carbon thus defining the possibility of ultra-deep diamonds generation.
DS201511-1883
2015
Solopova, N.A.Spivak, A.V., Solopova, N.A., Dubrovinsky, L.S., Litvin, Yu.A.Melting relations of multicomponent carbonate MgCOs-FeCO3-CaCO3-Na2COs system at 12-26 Gpa: application to deeper mantle diamond formation.Physics and chemistry of Minerals, Vol. 42, 10, pp. 817-824.TechnologyDiamond genesis - experimental
DS201909-2087
2019
Soloshenko, N.G.Shchukina, E.V., Agashev, A.M., Soloshenko, N.G., Streletskaya, M.V.Origin of the V. Grib pipe eclogites ( Arkhangelsk region, NW Russia): geochemistry, Sm-Nd and Rb-Sr isotopes and relation to regional Precambrian tectonics.Mineralogy and Petrology, in press available 20p. PdfRussia, Archangeldeposit - Grib

Abstract: In this paper, new main and trace elements and isotopic data are presented for 14 coarse-grained eclogite xenoliths from the V. Grib kimberlite pipe in the central part of the Arkhangelsk Diamondiferous Province. Based on reconstructed whole rock MgO content, this suite is divided into high-MgO and low-MgO varieties. Eclogitic groups have a similar range of variations in the trace element compositions of garnet, clinopyroxene and reconstructed whole rock. All eclogites show positive Eu anomalies in garnet and Sr anomalies in the whole rock. The negative correlation between the Mg#, Sr/Lu ratio and HREE in a whole rock points to upper and lower oceanic crustal rocks as a protolith for eclogites with high and low whole rock HREEs, respectively. Low-MgO eclogites with higher whole rock HREEs have the basaltic upper oceanic crustal protolith, whereas the protoliths of eclogites with lower whole rock HREEs could be of gabbroic composition from the lower oceanic crust. High-MgO eclogites could represent MgO-rich portions of oceanic crustal rocks: picritic/MgO basalt portions in the upper oceanic crust and troctolite portions in the lower oceanic crust. The Sr and Nd isotope compositions suggest a complex history of eclogites during their residence in the lithospheric mantle. Similarities in the Nd isotope compositions and two-point Sm-Nd isochron ages are evidence for re-equilibration of the Sm-Nd isotope system between the eclogite garnet and clinopyroxene via a pre-kimberlite thermal event at 396?±?24 Ma. The subset of clinopyroxenes from four eclogites has a Sr isotope composition that plots on the isochron at an age of 2.84 Ga, which reflects the time of the subduction event and emplacement into the lithosphere and corresponds to the time of the Belomorian Eclogite Province of Baltic Shield formation.
DS1992-0575
1992
Solova, I.P.Girnis, A.V., Solova, I.P., Ryabchikov, I.D., Guzhova, A.V.high pressure experiments on the conditions of generation of the Prairie Creek lamproite magmaGeochemistry International, Vol. 29, No. 4, pp. 94-102ArkansasLamproite, Experimental petrology
DS200512-1024
2003
Solova, I.P.Solova, I.P., Girnis, A.V., Rass, I.T., Keller, J., Kononkova, N.N.Different styles of evolution of CO2 rich alkaline magmas: the role of melt composition in carbonate silicate liquid immiscibility. ( Mahlberg)Periodico di Mineralogia, (in english), Vol. LXX11, 1. April, pp. 87-93.Europe, GermanyMagmatism
DS201709-2008
2017
Solovea, L.V.Kalasnikova, T.V., Solovea, L.V., Kostrovitsky, S.I.Metasomatic features in the mantle xenoliths from Obnajennaya kimberlite pipe - the mineral composition evidence.Goldschmidt Conference, abstract 1p.Russiadeposit - Obnajennaya

Abstract: The modal metasomatic alteration for lithosphere mantle may be investigated using mantle xenoliths from kimberlite pipes. The mantle xenoliths from upper-Jurassic Obnajennaya kimberlite pipe (Kuoika field, Yakutia) were studied. Three main xenoliths groups in Obnajennaya pipe were distinguished based on the petrographic and geochemical features: 1. Sp, Sp-Grt, Grt harzburgites - lherzolites, Sp, Sp-Grt, Grt olivine websterites and Sp, Sp-Grt, Grt websterite (so-called magnesium group - about 80 % from xenoliths). The high magnesium mineral composition, high estimated temperature (1250 - 1500°?) for exsolution pyroxene megacrystals, presence of sulphide globules and distribution curves for rare earth elements in garnets (La-Yb increasing) are to assume the crystallisation from melt. The 10% magnesium mantle xenoliths are observed the secondary metasomatic phlogopite and amphibole (pargasite). The clinopyroxene distribution curves demonstrate the wide range of values and altered samples show higher content HFSE group elements that primary clinopyroxene. The increasing of HFSE and rare earth element concentrations can also be traced by the amphibole chemical composition. The 40Ar/39Ar dating of phlogopite from was result 1639 ± 5 Ma nearly corresponding to the time of Siberian craton accretion Thus during Siberian craton accretion (about 1.7 Ga) the melts-fluids enriching Nb + Ta and REE impacted on lithosphere mantle under Kuoika field. 2. Eclogites and Grt clinopyroxenites with similar mineral composition (about 10-15% xenoliths). The high ?O18 for garnet and clinopyroxene (5.7–5.8‰) allows to assume subduction genesis. 3. Phl-Ilm rocks characterizing ferrous mineral composition (~ 10 % xenoliths). This group are charactetrized are ferrous mineral composition. The 40Ar/39Ar phlogopite dating resulted to 800-500 Ma, signed the potassium and titanium metasomatic fluide – melt influenced
DS2001-0997
2001
Solovena, I.Ryabichikov, I.D., Ntaflos, Th., Buchl, A., Solovena, I.Subalkaline picrobasalts and plateau basalts from the Putorana Plateau: mineral compositions and geochemistryGeochemistry International, Vol. 39, No. 5, pp. 415-31.Russia, SiberiaContinental flood basalt province, Picrites
DS201907-1578
2019
Solovera, L.Solovera, L., Kostrovitsky, S.I., Kalashnikova, T.V., Ivanov, A.V.The nature of phlogopite - ilmenite and ilmenite parageneses in deep seated xenoliths from Udachnaya kimberlite pipe.Doklady Earth Sciences, Vol. 486, 1, pp. 537-540.Russiadeposit - Udachnaya

Abstract: The article describes the petrography and mineralogy of xenoliths ilmenite-phlogopite containing deformed and granular peridotites from the Udachnaya-Eastern pipe. The age of pholopite porphyroclast from the studied deformed xenoliths matches with age of Phl megacryst and itself hosted kimberlites from Udachnaya pipe indicating the following processes closed in time: (1) crystallization of the low-Cr megacryst association; (2) deformation of rocks on the mantle lithosphere-asthenosphere border during the kimberlite-forming cycle; (3) formation of protokimberlite melts.
DS201312-0605
2013
Solovev, A.V.Miller, E.L., Solovev, A.V., Prokopiev, A.V., Toro, J., Harris, D., Kuzmichev, A.B., Gehrels, G.E.Triassic river systems and the paleo-Pacific margin of northwestern Pangea. Lena River systemGondwana Research, Vol. 23, 4, pp. 1631-1645.RussiaSource areas
DS202110-1637
2021
Solovev, K.A.Solovev, K.A., Golovin, A.V., Sharygin, I.S., Pokhilenko, N.P.Origin of epigenetic iron-rich olivine in lherzolite xenolith from the Udachnaya kimberlite pipe ( Siberian craton).Doklady Earth Sciences, Vol. 499, 2, pp. 619-622.Russiadeposit - Udachnaya

Abstract: Olivine is the most common rock-forming mineral of the majority of the lithospheric mantle rocks beneath ancient cratons. This study provides the information about an epigenetic olivine in a lherzolite xenolith from the Udachnaya kimberlite pipe (Siberian craton), which is characterized by lower Mg# compared to the rock-forming one (Mg# = 87.4). The iron-rich olivine has been observed in the epigenetic mineral assemblage that forms a kelyphite shell around the rock-forming garnet. Olivine from the kelyphite shell occurs as both homogeneous grains (Mg# = 84.3-85.9) and zoned grains (Mg# = 85.1-87.5). The major and minor elements asymmetric zoning patterns have been found in the rock-forming olivine grains at the contact with the kelyphite shell. These olivine grains have an outer low Mg# (up to 85.9) zone at the contact with the kelyphite shell as the epigenetic olivine grains in the kelyphite shell. We suggest that the iron-rich epigenetic olivine was produced as the result of a reaction between the rock-forming garnet and the primitive kimberlite melt. During this reaction, a hybrid melt was formed in the interstitial space. The hybrid melt was iron-enriched relative to the kimberlite melt. The source of iron for the micro-portions of the interstitial hybrid melt was the rock-forming garnet.
DS202112-1945
2021
Solovev, K.A.Sharygin, I.S., Golovin, A.V., Dymshits, A.M., Kalugina, A.D., Solovev, K.A., Malkovets, V.G., Pokhilenko, N.P.Relics of deep alkali-carbonate melt in the mantle xenolith from the Komosomolskaya-Magnitnaya kimberlite pipe ( Upper Muna field, Yakutia).Doklady Earth Sciences, Vol. 500, 2, pp. 842-847.Russia, Yakutiadeposit - Komosomolskaya-Magnitnaya

Abstract: The results of study secondary crystallized melt inclusions in olivine of a sheared peridotite xenolith from the Komsomolskaya-Magnitnaya kimberlite pipe (Upper Muna field, Yakutia) are reported. Monticellite, phlogopite, tetraferriphlogopite KMg3(Fe3+)Si3O10(F,Cl,OH), apatite, aphthitalite K3Na(SO4)2, burkeite Na6CO3(SO4)2, and carbonates, namely calcite, nyerereite (Na,K)2Ca(CO3)2, shortite Na2Ca2(CO3)3, and eitelite Na2Mg(CO3)2, were detected among the daughter minerals of the melt inclusions by the method of confocal Raman spectroscopy. The abundance of alkali carbonates in the inclusions indicates the alkali-carbonate composition of the melt. Previously, identical inclusions of alkali-carbonate melt were reported in olivine of sheared peridotites from the Udachnaya pipe (Daldyn field). Melt inclusions in sheared peridotites are the relics of a crystallized kimberlite melt that penetrated into peridotites either during the transport of xenoliths to the surface or directly in the mantle shortly prior to the entrapment of xenoliths by the kimberlite magma. If the second scenario took place, the finds of alkali-carbonate melt inclusions in sheared peridotites carried from different mantle depths in the Udachnaya and Komsomolskaya-Magnitnaya kimberlite pipes indicate a large-scale metasomatic alteration of the lithospheric mantle of the Siberian Craton by alkaline-carbonate melts, which preceded the kimberlite magmatism. However, regardless of which of the two models proposed above is correct, the results reported here support the alkali-carbonate composition of primary kimberlite melts.
DS1989-0516
1989
Solovev, V.A.Gladkikh, V.S., Solovev, V.A.Niobium and zirconium in alkaline olivine basalts and alkaline basaltoids of the Baikal-Mongolian regions as criteria for estimating their distrib. In mantle sourceSoviet Geology and Geophysics, Vol. 30, No. 2, pp. 62-68RussiaAlkaline basaltoids, Rare earths
DS1990-1393
1990
Solovev, V.O.Solovev, V.O.Final magmatism: pecularities of its manifestation and itsgeologicalmessenceSoviet Geology and Geophysics, Vol. 31, No. 3, pp. 56-61RussiaMagma, Tectonics
DS2002-1525
2002
SolovevaSolovevaMegacrystalline orthopyroxenite with graphite from the Udachnaya pipe, YakutiaDoklady Earth Sciences, Vol. 385, 5 June-July, pp.589-92.Russia, YakutiaMineralogy, Deposit - Udachnaya
DS200612-0366
2006
SolovevaEgorov, K.N., Soloveva, Kovach, Menshagin, Maslovskaya, Sekerin, BankovskayaPetrological features of olivine phlogopite lamproites of the Sayan region: evidence from the Sr Nd isotope and ICP MS trace element data.Geochemistry International, Vol. 44, 7. pp. 729-735.RussiaLamproite
DS201212-0689
2012
SolovevaSoloveva, Kostrovitsky, S., Yasnygina, T.A.Fluid and magma transfer in subcontinental lithospheric mantle of the Siberian craton and its geochemical evolution.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, SiberiaGeochemistry
DS2000-0915
2000
Soloveva, L.V.Soloveva, L.V., Gornova, M.A., Lozhkin, V.I.Trace elements in the xenoliths of pyroxenites, eclogites and mafic granulites from Udachnaya ...Doklady Academy of Sciences, Vol. 373A, No. 6, Aug-Sept. pp.1004-7.Russia, YakutiaGeochemistry, Deposit - Obnazhennaya, Udachnaya
DS2001-1103
2001
Soloveva, L.V.Soloveva, L.V., Gornova, M.A.Geochemical prototypes of basic granulites from Yakutian kimberlitesDoklady Academy of Sciences, Vol. 377, No. 2, Feb-Mar. pp.204-6.Russia, YakutiaChemistry - granulites
DS2002-1526
2002
Soloveva, L.V.Soloveva, L.V., Kostrovitskii, S.I., Ukhanov, A.V., Suvorova, L.F., AlymovaMegacrystalline orthopyroxenite with graphite from the Udachanaya pipe, YakutiaDoklady, Vol.385,June-July, pp. 589-92.Russia, YakutiaMineralogy, Deposit - Udachnaya
DS200412-0510
2004
Soloveva, L.V.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
DS200412-1874
2004
Soloveva, L.V.Soloveva, L.V., Gornova, M.A., Markova, M.E., Lozhkin, V.I.Geochemical identification of granulites in xenoliths from Yakutian kimberlites.Geochemistry International, Vol. 42, 3, pp. 220-235.Russia, YakutiaGeochemistry
DS200412-1875
2004
Soloveva, L.V.Soloveva, L.V., Gornova, M.A., Egorov, K.N., Smironov, E.V.REE and HFSE distribution in rocks and minerals from granular peridotite xenoliths in the Udachnaya kimberlite pipe.Doklady Earth Sciences, Vol. 395, 4, March-April, pp. 456-460.Russia, YakutiaGeochemistry
DS200412-1876
2004
Soloveva, L.V.Soloveva, L.V., Gornova, M.A., Lozhkin, V.I.Geochemical identification of granulites in xenoliths from Yakutian kimberlites.Geochemistry International, Vol. 42, 3, pp. 220-235.Russia, YakutiaGeochemistry
DS200612-0367
2005
Soloveva, L.V.Egorov, K.N., Soloveva, L.V., Kovach, V.P., Menshagin, Y.V., Maslovskaya, Sekerin, A.P., Bankovskaya, E.V.Mineralogical and isotope geochemical characteristics of Diamondiferous lamproites of the Sayan region.Doklady Earth Sciences, Vol. 403A, 6, pp. 861-865.RussiaGeochronology
DS200812-1095
2008
Soloveva, L.V.Soloveva, L.V., lavrentew, Y.G., Egorov, K.N., Kostrovitskii, S.I., Korolyuk, V.N., Suvorova, L.F.The genetic relationship of the deformed peridotites and garnet megacrysts from kimberlites with asthenospheric melts.Russian Geology and Geophysics, Vol. 49, 4, pp. 207-224.RussiaPetrology - Udachnaya
DS201012-0737
2010
Soloveva, L.V.Soloveva, L.V., Yasnygina, T.A., Korolyuk, V.N., Egorov, K.N.Geochemical evolution of deep fluids in the mantle lithosphere of the Siberian Craton during the Middle Paleozoic kimberlite cycle.Doklady Earth Sciences, Vol. 434, 2, pp.1330-1336.RussiaGeochemistry - melting
DS201012-0738
2010
Soloveva, L.V.Soloveva, L.V., Yasnygina, T.A., Kostrovitskii, S.I.Isotopic and geochemical evidence for a subduction setting during formation of the mantle lithosphere in the northeastern part of the Siberian Craton.Doklady Earth Sciences, Vol. 432, 2, pp. 799-803.RussiaSubduction
DS201212-0182
2012
Soloveva, L.V.Egorov, K.N., Soloveva, L.V., Koshkarev, D.A.Rare element composition of pyropes and lamproites and ancient dispersion haloes of the southwestern Siberian platform.Doklady Earth Sciences, Vol. 443, 2, pp. 496-501.Russia, SiberiaLamproites - Ingashin, Prisayan region
DS201212-0183
2012
Soloveva, L.V.Egorov, K.N., Soloveva, L.V., Koshkarev, D.A.Rare element composition of pyropes and lamproites and ancient dispersion haloes of the southwestern Siberian platform.Doklady Earth Sciences, Vol. 443, 2, pp. 496-501.Russia, SiberiaIngashin field
DS201212-0376
2012
Soloveva, L.V.Kostrovitskii, S.I., Soloveva, L.V., Gornova, M.A., Alymova, N.V., Yakolev, D.A., Ignative, A.V., Velivetskaya, T.A., Suvorova, L.F.Oxygen isotope composition in minerals of mantle parageneses from Yakutian kimberlites.Doklady Earth Sciences, Vol. 444, 1, pp. 579-584.Russia, YakutiaDeposit - Udachnaya, Komsomolskaya
DS201312-0509
2013
Soloveva, L.V.Kostrovitsky, S.I., Soloveva, L.V., Yakovlev, D.A., Suvorova, L.F., Sandimirova, G.P., Travin, A.V., Yudin, D.S.Kimberlites and megacrystic suite: isotope geochemical studies.Petrology, Vol. 21, 2, pp. 127-144.Russia, YakutiaDeposit - Udachnaya
DS201312-0867
2012
Soloveva, L.V.Soloveva, L.V., Yasnygina, T.A., Egorov, K.N.Metasomatic parageneses in deep seated xenoliths from pipes Udachnaya and Komosomolskaya Magnitinaya as indicators of fluid transfer through the manyle lithosphere of the Siberian Craton.Russian Geology and Geophysics, Vol. 53, 12, pp. 1291-1303.RussiaDeposit - Udachnaya, Komosomolskaya
DS201412-0867
2014
Soloveva, L.V.Soloveva, L.V., Kalashnikova, T.V., Kostrovitsky, S.I., Suvorova, L.F.Zoning of garnets in deformed peridotites from the Udachnaya kimberlite pipe.Doklady Earth Sciences, Vol. 457, 2, pp. 997-1002.RussiaDeposit - Udachnaya
DS202008-1409
2020
Soloveva, L.V.Klashnikova, T.V., Soloveva, L.V., Kostrovitsky, S.I., Sun, J.Geochemical features of peridotite xenolith from Obnazhennaya kimberlite pipe - cumulates or residues?Goldschmidt 2020, 1p. AbstractRussiadeposit - Obnazhennaya

Abstract: This study concerns the geochemical characteristics of mantle xenoliths from the upper-Jurassic Obnazhennaya kimberlite pipe (Kuoika field, Yakutian kimberlite province, the north-east of Siberian craton). The so-called magnesian xenolith group (Sp, Sp-Grt, Grt lherzolites, olivine websterites and websterites) was distinguished, the rocks of the group are assumed to be of the same genesis based on transitions in modal mineral composition and a change in the composition of minerals. The chemical composition (CaO, MgO) of most depleted harzburgites, as well as part of the lherzolites of the magnesian group coincide with the restites obtained by experimental melting, which suggested their residue origin. Narrow variations in the composition of olivine (Mg # - 91-92; NiO - 0.35-0.45 wt.%) and orthopyroxene (Mg # - 92-93) for Obnazhennaya peridotites also support this hypothesis. In terms of chemical composition, olivines coincide with the “mantle trend” of olivines from the lithospheric mantle. Nevertheless, garnets from the peridotites consistently change their composition in the direction of decreasing Cr2O3, CaO and Mg # values from Grt, Sp-Grt lherzolites to Grt websterites. The garnet composition from Obnazhennaya peridotites differs from Udachnaya peridotites, for which the residue hypothesis assumed. They are similar in composition to garnets from Beni-Bousera garnet pyroxenites, as well as to garnets from deformed lherzolites of the Udachnaya pipe, which suggests crystallization of garnets from the melt and the effect of metasomatic processes. The formation of orogenic massifs is a multi-stage process, many authors suggest that pyroxenite veins in mafic complexes are cumulative in origin and show signs of metasomatic processes (in particular, enrichment with aluminum, calcium and chromium, increased REE concentrations in garnet). So peridotite cumulative origin and further metasomatic transformations were suggested.
DS200812-0102
2008
Soloviev, A.A.Belov, S.V., Burmistrov, A.A., Soloviev, A.A., Kedrov, E.O.Carbonatites and kimberlites of the world... database and geoinformation system: experience of creation and use for solving geological tasks.AIP Conference Proceedings, American Institute of Physics, No. 1009, pp. 113-122.GlobalDatabase
DS1993-1051
1993
Soloviev, N.S.Mironov, Yu.B., Soloviev, N.S.Geology and metallogeny of the north Choibalasan region, MongoliaRussian Geology and Geophysics, Vol. 33, No. 3, pp. 60-65Russia, MongoliaMetallogeny, Tectonics
DS1984-0699
1984
Solovieva, L.V.Solovieva, L.V., Vladimirov, B.M., Zavialova, L.L., Barankevich.Deep Seated Inclusions of the Complex Type from the Udachnaia Kimberlite Pipe.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 277, No. 2, PP. 461-466.RussiaBlank
DS1989-0464
1989
Soloviova, L.V.Galimov, E.M., Soloviova, L.V., Belomestnykh, A.V.Carbon isotope composition of different forms of carbon in eclogite from Mir kimberlite pipe.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 305, No. 4, pp. 953-956RussiaEclogite, Geochronology
DS201012-0681
2010
Solovive, S.Seltmann, R., Solovive, S., Shatov, V., Piranjo, F., Naumov, E., Cherkasov, S.Metallogeny of Siberia: tectonic, geologic and metallogenic settings of selected significant deposits.Australian Journal of Earth Sciences, Vol. 57, no. 8, pp. 655-706.Russia, SiberiaOverview ... brief mention of diamonds
DS1986-0772
1986
Solovjeva, L.V.Solovjeva, L.V.Heterogeneity of the upper mantle beneath the Siberian PlatformProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 340-342RussiaBlank
DS1991-0431
1991
Solovjeva, L.V.Egorov, K.N., Bogdanov, V., Solovjeva, L.V., Barankevich, V.G.Evidence of magmatism, metasomatism and deformation processes obtained From the study of the unique compositionally complex nodule from the Udachanya pipeProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 495-497RussiaNodule, Deposit -Udachnaya
DS1991-1630
1991
Solovjeva, L.V.Solovjeva, L.V., Dneprovskaya, M.N., Brandt, S.B.Oxygen, Carbon and Strontium isotopic composition of calcites in garnet megacrysts and carbonatized granulitic xenoliths from the Udachnaya kimberlite pipe, YakutiaProceedings of Fifth International Kimberlite Conference held Araxa June, pp. 558-559RussiaGeochronology, Calcites
DS1991-1631
1991
Solovjeva, L.V.Solovjeva, L.V., Vladirmirov, B.M.Cognate suite of garnet clinopyroxenite -olivine websterite lherzolite From the Udachanya kimberlite pipe, YakutiaProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 560-561RussiaMineral chemistry, Lherzolite
DS1991-1632
1991
Solovjeva, L.V.Solovjeva, L.V., Zavjalova, L.L.Layered structure of the upper mantle beneath the Siberian platform:petrological and geophysical dataProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 562-563RussiaXenoliths, Geophysics
DS1991-1633
1991
Solovjeva, L.V.Solovjeva, L.V., Barankevich, V.G., Lipskaya, L.L.Metasomatic processes in subcontinental lithospheric mantle beneath the Siberian PlatformProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 556-557RussiaDeposit -Udachnaya, Mantle xenoliths
DS1995-1802
1995
Solovjeva, L.V.Solovjeva, L.V., Dneprovskaya, L.R., Lipskaya, V.I., et al.Deformed dunites from the Udachnaya pipeProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 564-565.Russia, YakutiaDunites, Deposit -Udachnaya
DS1995-1803
1995
Solovjeva, L.V.Solovjeva, L.V., Egorov, K.N., Dneprovskaya, L.R., et al.The role of fO2 regime in evolution of mantle metasomatism and diamondformation.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 566-568.MantleOxygen fugacity, Metasomatism
DS1995-1804
1995
Solovjeva, L.V.Solovjeva, L.V., Kislev, A.I., Mordvinova, BarankevichEvolution of the ancient subcontinental lithosphere from the deep seated and lower crust xenoliths data.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 569-571.Russia, Yakutia, Anabar, SiberiaXenoliths, Deposit -Udachnaya, Obnazhennaya
DS1998-1380
1998
Solovjeva, L.V.Solovjeva, L.V., Barankevich, V.G., Bayukov, O.A.Polychrome olivines in coarse grained lherzolites from the Udachnaya pipe -possible fine indicators ...7th International Kimberlite Conference Abstract, pp. 841-3.Russia, YakutiaMetasomatism, xenoliths, Deposit - Udachnaya
DS2001-0397
2001
Solovjeva, L.V.Gornova, M.A., Solovjeva, L.V., Glazunov, BelozerovaFormation of Precambrian lithosphere mantle geochemical analysis of coarseAlkaline Magmatism -problems mantle source, pp. 223-41.Russia, SiberiaCraton, Geochemistry
DS200512-0353
2002
Solovjeva, L.V.Gornova, M.A., Solovjeva, L.V.Application of rare element composition of garnet and clinopyroxene from peridotite xenoliths ( Udachnaya kimberlite) for modeling of primitive mantle meltingDeep Seated Magmatism, magmatism sources and the problem of plumes., pp. 148-162.RussiaREE - melting
DS200512-0354
2001
Solovjeva, L.V.Gornova, M.A., Solovjeva, L.V., Glazunov, O.M., Belozerova, O.Yu.Formation of Precambrian lithosphere mantle - geochemical analysis of coarse grained peridotites from kimberlites, Siberian Craton.Alkaline Magmatism and the problems of mantle sources, pp. 223-241.Russia, SiberiaGeochemistry
DS200512-1025
2005
Solovjeva, L.V.Solovjeva, L.V., Egorov, K.N., Kostrovitsky, S.I., Gornova, M.A.The effect of different metasomatic processes on geochemical heterogeneity of upper mantle of the Siberian craton.GAC Annual Meeting Halifax May 15-19, Abstract 1p.Russia, Yakutia, SakhaUdachnaya, geochemistry
DS200612-1333
2006
Solovjeva, L.V.Solovjeva, L.V., Egorov, K.N.Effects of the Yakutian plume on processes within the upper mantle of the Siberian Craton: geochemical data.Vladykin: VI International Workshop, held Mirny, Deep seated magmatism, its sources and plumes, pp. 104-124.Russia, SiberiaHotspots, metamorphism
DS200712-0781
2006
Solovoa, I.P.Nielsen, T.F.D., Turkov, V.A., Solovoa, I.P., Kogarko, L.N., Ryabchikov, I.D.A Hawaiian beginning for the Iceland plume: modeling of reconnaissance olivine hosted melt inclusions in Palaeogene picrite lavas from east Greenland.Lithos, Vol. 92, 1-2, Nov, pp. 83-104.Europe, GreenlandPicrite
DS201212-0690
2012
Solovoa, I.P.Solovoa, I.P., Girnis, A.V.silicate carbonate liquid immiscibility and crystallization of carbonate and K rich basaltic magma: insights from melt and fluid inclusions.Mineralogical Magazine, Vol. 76, 2, pp. 411-439.MantleCarbonatite, melting
DS1970-0673
1973
Solovov, A.P.Eremeev, A.N., Sokolov, V.A., Solovov, A.P., Yanitskii, I.N.Application of Helium Surveying to Structural Mapping and Ore Deposit Forecasting.International GEOCHEM. Exploration Symposium 4TH., PP. 183-192.RussiaKimberlite, Geophysics
DS1998-1270
1998
SolovovaRyabchikov, I., Brooks, C.K., Kogarko, Nielsen, SolovovaTertiary picrites from Greenland: modelling sources and petrogenesis from melt inclusion compositions.Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1306-7.GreenlandMagnesian melts, Plume
DS1991-0576
1991
Solovova, I.Girnis, A., Solovova, I., Ryabchikov, I., Kogarko, L.Petrogenesis of Prairie Creek lamproites: constraints from melt inclusion sand high pressure experimentsProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, p. 513ArkansasLamproite, Deposit -Prairie Creek
DS1991-1634
1991
Solovova, I.Solovova, I., Girnis, A., Kogarko, L., Ryabchikov, I.A study of Micro inclusions in minerals of Spanish lamproitesProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, p. 564GlobalLamproite, Melt inclusions
DS1991-1635
1991
Solovova, I.Solovova, I., Girnis, A., Naumov, V., Guzhova, A.Immiscible salt and silicate melts: dat a from Micro inclusions in minerals of alkali basaltsEuropean Current Research Fluid Inclusions, Firenze, Italy April 10-12, Abstracts, ECROFI XI, p. 205RussiaCarbonatite, Fluid inclusions
DS1992-1453
1992
Solovova, I.Solovova, I., Girnis, A., Ryabchikov, D.Fluid regime of highly potassic mafic-ultramafic magmasProceedings of the 29th International Geological Congress. Held Japan August 1992, Vol. 1, abstract p. 195Arkansas, AustraliaLamproites, Carbon dioxide
DS200912-0021
2009
Solovova, I.Babansky, A., Solovova, I.Mineralogy and geochemistry of K rich basalts of the central part of the Sredinnyi Range, Kamchatka.alkaline09.narod.ru ENGLISH, May 10, 2p. abstractRussiaMineralogy
DS200912-0712
2009
Solovova, I.Solovova, I., Girnis, A., Kopylova, M.Fluid and melt inclusions in minerals of West Greenland lamprophyres. Maniitsoq areaalkaline09.narod.ru ENGLISH, May 10, 2p. abstractEurope, GreenlandChemistry
DS201012-0739
2010
Solovova, I.Solovova, I., Girnis, A.Potassium rich carbonatite magma: mechanism of formation and mineralogy as a result of examination melt inclusions (eastern Pamir).International Mineralogical Association meeting August Budapest, abstract p. 577.Russia, PamirCarbonatite
DS1982-0578
1982
Solovova, I.P.Solovova, I.P., et al.Inclusions of High Density Co2 in Mantle LherzolitesDoklady Academy of Sciences Nauk SSSR., Vol. 263, No. 1, PP. 179-182.RussiaKimberlite
DS1986-0690
1986
Solovova, I.P.Ryabchikov, I.D., Solovova, I.P., Sobolev, N.V., Sobolev, A.V.Nitrogen in lamproitic magmas.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 288, No. 4, pp. 976-979RussiaLamproite
DS1987-0369
1987
Solovova, I.P.Kovalenko, V.I., Solovova, I.P., Ryabchikov, I.D., et al.Fluidized CO2 sulphide silicate media as agents of mantle metasomatism and megacrysts formation: evidence from a large druse in a spinel lherzolitexenolithPhysics of the Earth and Planetary Interiors, Vol. 45, No.3 April pp. 280-293GlobalPetrology
DS1987-0701
1987
Solovova, I.P.Solovova, I.P., Kovalenko, V.I., Naumov, V.B., Ryabchikov, I.D.Carbon dioxide sulfide silicate inclusions in clinopyroxenes ofmantlexenolithsDoklady Academy of Science USSR, Earth Science Section, Vol. 285, No. 1-6, August pp. 111-114RussiaBlank
DS1988-0651
1988
Solovova, I.P.Solovova, I.P., Kogarko, L.N., Ryabchikov, I.D., et al.Spanish high pressureotassium magmas and evidence of their generation depth ( as inferred from thermobarogeochemical data)Dokl. Acad. Sciences USSR Earth Science Section, Vol. 303, No. 6, pp. 101-103GlobalUltrapotassic -lamproite like, Magma
DS1988-0652
1988
Solovova, I.P.Solovova, I.P., Kogarko, L.N., Ryabchikov, I.D., Naumov, V.B.high pressureotassium magmas of Spain and evidence of their formation depth from thermobaro geochemical data.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 303, No. 1, pp. 182-185GlobalLamproite, Geothermometry
DS1989-1430
1989
Solovova, I.P.Solovova, I.P., Ghirnis, A.V., Kogarko, L.N., Ryabchik.., I.D.Geochemical pecularities of Prior Creek lamproites based on dat a of studyof Micro inclusions inolivines.(Russian) (Prairie CreekArk.?)Geochemistry International (Geokhimiya), (Russian), No. 10, October pp. 1449-1459RussiaLamproite, Geochemistry
DS1996-1349
1996
Solovova, I.P.Solovova, I.P., Girnia, A.V., Ryabchikov, I.D.Inclusions of carbonate and silicate melts in minerals of alkali basaltoids from the East Pamirs.Petrology, Vol. 4, No. 2, pp. 339-363.Russia, PamirAlkalic rocks, Basaltoids -potassic
DS1997-0845
1997
Solovova, I.P.Nielsen, T.F.D., Solovova, I.P., Veksler, I.V.Parental melts of melilitolite and origin of alkaline carbonatite: evidence from crystallized melt inclusionsContributions to Mineralogy and Petrology, Vol. 126, No. 4, pp. 331-344.GreenlandGardiner Complex, Melilitolite
DS1998-1381
1998
Solovova, I.P.Solovova, I.P., Ryabchikov, I.D., Kogarko, KononkovaInclusions in minerals of the Palaborwa carbonatite complex, South AfricaGeochemistry International, Vol. 36, No. 5, pp. 377-388.South AfricaCarbonatite, Deposit - Palabora
DS2001-0998
2001
Solovova, I.P.Ryabichikov, I.D., Solovova, I.P., Ntaflos, Th., BuchlSubalkaline picrobasalts: melt inclusion chemistry, composition of primary magmas and P T regime -Geochemistry International, Vol. 39, No. 5, pp. 432-46.Russia, SiberiaSuperplume
DS2002-1377
2002
Solovova, I.P.Ryabchikov, I.D., Solovova, I.P., Kogarko, L.N., Bray, G.P., Ntaflos, Th.Thermodynamic parameters of generation of meymechites and alkaline picrites in theGeochemistry International, Vol. 40, 11, pp. 1031-41.RussiaPicrites, meymechites
DS2003-1311
2003
Solovova, I.P.Solovova, I.P., Girnis, A.V.Extraction of ore components from mafic magmas by immiscible carbonate and saltin Mineral Exploration and Sustainable Development Vol. 1, eds. Eliopoulos et al., Ore forming processes associated with mafic and ultramafic rockseast Greenlandalkaline igneous complex, Verknedunkeldykskii massif, Gardiner massif
DS200612-0978
2006
Solovova, I.P.Nielsen, T.F.D.,Turkov, V.A., Solovova, I.P., Kogarko, L.N., Ryabchikov, I.D.A Hawaiian beginning for the Iceland plume: modelling of reconnaissance dat a for olivine hosted melt inclusions in Palaeogene picrite lavas East Greenland.Lithos, in press availableEurope, GreenlandPicrite, melting
DS200612-1334
2005
Solovova, I.P.Solovova, I.P., Girnis, A.V., Kogarko, L.N., Kononkova, N.N., Stoppa, F., Rosaatelli, G.Compositions of magma and carbonate silicate liquid immiscibility in the Vulture alkaline igneous complex, Italy.Lithos, Vol. 85, 1-4, Nov-Dec. pp. 113-128.Europe, ItalyCarbonatite
DS200612-1335
2006
Solovova, I.P.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
DS200912-0656
2009
Solovova, I.P.Ryabichikov, I.D., Kogarko, L.N., Solovova, I.P.Physicochemical conditions of magma formation at the base of the Siberian plume: insights from the investigation of melt inclusions in the meymechites and alkali picrites of the Maimecha KotuiPetrology, Vol. 17, 3, May pp. 287-199.RussiaPicrite
DS201012-0740
2009
Solovova, I.P.Solovova, I.P., Girnis, A.V., Ryabchikov, I.D., Kononkova, N.N.Mechanisms of formation of barium rich phlogopite and strontium rich apatite during the final stages of alkaline magma evolution.Geochemistry International, Vol. 47, 6, June, pp. 578-591.MantleMagmatism
DS201112-0984
2011
Solovova, I.P.Solovova, I.P., Girnis, A.V., Kogarko, L.N., Kononkova, N.N.Compositions of magmas and carbonate silicate liquid immiscibility in the Vulture alkaline igneous complex, Italy.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., pp. 150-170.Europe, ItalyCarbonatite
DS201212-0691
2012
Solovova, I.P.Solovova, I.P., Ohnenstetter, D., Girnis, A.V.Melt inclusions in olivine from boninites of New Caledonia: postentrapment melt modification and estimation of primary magma compositions.Petrology, Vol. 20, 6, pp. 529-544.AsiaBoninites
DS201312-0868
2012
Solovova, I.P.Solovova, I.P., Girnis, A.V., Kononkova, N.N.Relationships of carbonate and K rich basaltoid magmas: insight from melt and fluid inclusions.Vladykin, N.V. ed. Deep seated magmatism, its sources and plumes, Russian Academy of Sciences, pp. 164-203.MantleMetasomatism
DS201412-0868
2014
Solovova, I.P.Solovova, I.P., Girnis, A.V.Behavior of F and Cl in agpaitic acid melts.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., pp. 155-159.TechnologyMelting
DS1993-1508
1993
Solovyev, S.G.Solovyev, S.G.Late Paleozoic subalkaline potassic shoshonite-latite magmatism in Central Tien Shan.International Geology Review, Vol. 35, No. 3, March pp. 288-?ChinaAlkaline rocks
DS1950-0422
1958
Solov'yev, D.S.Rabkin, M.I., Solov'yev, D.S.Kimberlites and Diamond Deposits of the Middle Course of The Olenek River.Leningrad: Niiga., Vol. 97.RussiaBlank
DS1988-0653
1988
Solovyeva, I.A.Solovyeva, I.A.Deep structure of shields of cratons (review and problems)Geotectonics, Vol. 21, No. 2, pp. 91-101RussiaShield, Craton
DS1987-0702
1987
Solovyeva, I.V.Solovyeva, I.V., Vladimirov, B.M., Kiselev, A.I.Types of mantle metasomatism and their probable connection with the lithospheric processes.(Russian)Metasomatism and Ore genesis, Theses of reports, The VI all union, pp. 36-37. AbstractRussiaKimberlite, Petrology
DS1981-0391
1981
Solovyeva, L.V.Solovyeva, L.V., Vladimirov, B.M., Kostrovitskiy, S.I.Autoliths of Kimberlites and their GenesisIzvest. Akad. Nauk Sssr Geol. Ser., No. 7, PP. 5-18.RussiaGenesis
DS1984-0426
1984
Solovyeva, L.V.Kostrovitsky, S.I., Vladimrov, B.M., Solovyeva, L.V.Association of Mineral Inclusions in Olivine in Kimberlites.(russian)Doklady Academy of Sciences Akademy Nauk SSSR (Russian), Vol. 276, No. 2, pp. 451-454RussiaMineralogy
DS1986-0458
1986
Solovyeva, L.V.Kostrovitskiy, S.I., Vladimirov, B.M., Solovyeva, L.V., FiveyskayaAssociations of mineral inclusions in olivine from kimberliteDoklady Academy of Science USSR, Earth Science Section, Vol. 276, January pp. 114-117RussiaUdachnaya, Mineralogy
DS1986-0773
1986
Solovyeva, L.V.Solovyeva, L.V., Vladimirov, B.M., Zavyalova, L.L., Barankevich, V.V.Complex deep seated inclusions from the Udachnaya kimberlite pipeDoklady Academy of Science USSR, Earth Science Section, Vol. 277, March pp. 77-82RussiaYakutia, Analyses
DS1986-0842
1986
Solovyeva, L.V.Vladimirov, B.M., Solovyeva, L.V.A comparative study of fluid and melt inclusions, theircompositions, time-space relations, genesis and tectoniccontrolProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 95-96GlobalClassification
DS1988-0654
1988
Solovyeva, L.V.Solovyeva, L.V., Barankevich, V.G., Zavyalova, L.L., Lipskaya, V.I.Metasomatic alterations in ferromagnesian eclogite from the UdachnayapipeDokl. Acad. Sciences USSR Earth Science Section, Vol. 303, No. 6, pp. 107-110RussiaEclogite, Alteration
DS1989-0465
1989
Solovyeva, L.V.Galimov, E.M., Solovyeva, L.V., Belomesnyy, A.B.Isotopic composition of various forms of carbon in eclogite from kimberlite of the Mir pipeDoklady Academy of Sciences USSR, Earth Science Section, Vol. 305, No. 2, March-April pp. 204-206RussiaCarbon, Eclogite -Mir pipe
DS1990-0509
1990
Solovyeva, L.V.Galimov, E.M., Solovyeva, L.V., Belomestnykh, A.V.Carbon isotope composition of metasomatized mantle rocksGeochemistry International, Vol. 26, No. 11, April pp. 38-43RussiaMantle, Geochronology
DS201212-0378
2012
Solovyevas, L.V.Kostrovitsky, S.I.,Gornova, M.A.,Solovyevas, L.V., Yakolev, D.A.Isotope heterogeneity from oxygen in rocks of lithospheric mantle.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussiaDeposit - Udachnaya
DS1990-1394
1990
Solow, A.R.Solow, A.R.Geostatistical cross-validation: a cautionary noteMath. Geol, Vol. 22, No. 6, August pp. 637-639GlobalGeostatistics, Cross validation
DS1993-1509
1993
Solow, A.R.Solow, A.R.On the efficiency of the indicator approach in geostatisticsMathematical Geology, Vol. 25, No. 1, pp. 53-57GlobalGeostatistics, Kriging
DS1993-1510
1993
Solow, R.Solow, R.An almost practical step towards sustainabilityResources Policy, Vol. 19, No. 3, September pp. 162-172GlobalEconomics, Metal markets
DS200712-0593
2007
Solozhenko, V.L.Langenhorst, F., Solozhenko, V.L.ATEM-EELS study of diamond like phases in the B-C-N system.Plates, Plumes, and Paradigms, 1p. abstract p. A542.TechnologyB-C-N compounds
DS201112-0985
2011
Soltani, S.Soltani, S., Hezarkhani, A.Determination of realistic and statistical value of the information gathered from exploratory drilling.Natural Resources Research, in press available, 8p.TechnologyGeostatistics - not specific to diamonds
DS201412-0869
2014
Soltanmohammadi, A.Soltanmohammadi, A., Rahgoshay, M., Ceuleneer, G.Clinopyroxene composition of mafic-ultramafic xenoliths in alkaline rocks, northwestern Iran: an example of cognate type xenoliths in lamprophyres.30th. International Conference on Ore Potential of alkaline, kimberlite and carbonatite magmatism. Sept. 29-, IranXenoliths
DS201606-1119
2016
Soltys, A.Soltys, A., Giuliani, A., Phillips, D., Kamenetsky, V.S., Maas, R., Woodhead, J., Rodemann, T.In-situ assimilation of mantle minerals by kimberlitic magmas - direct evidence from a garnet wehrlite xenolith entrained in the Bultfontein kimberlite ( Kimberley, South Africa).Lithos, Vol. 256-257, pp. 182-196.Africa, South AfricaDeposit - Bultfontein

Abstract: The lack of consensus on the possible range of initial kimberlite melt compositions and their evolution as they ascend through and interact with mantle and crustal wall rocks, hampers a complete understanding of kimberlite petrogenesis. Attempts to resolve these issues are complicated by the fact that kimberlite rocks are mixtures of magmatic, xenocrystic and antecrystic components and, hence, are not directly representative of their parental melt composition. Furthermore, there is a lack of direct evidence of the assimilation processes that may characterise kimberlitic melts during ascent, which makes understanding their melt evolution difficult. In this contribution we provide novel constraints on the interaction between precursor kimberlite melts and lithospheric mantle wall rocks. We present detailed textural and geochemical data for a carbonate-rich vein assemblage that traverses a garnet wehrlite xenolith [equilibrated at ~ 1060 °C and 43 kbar (~ 140-145 km)] from the Bultfontein kimberlite (Kimberley, South Africa). This vein assemblage is dominated by Ca-Mg carbonates, with subordinate oxide minerals, olivine, sulphides, and apatite. Vein phases have highly variable compositions indicating formation under disequilibrium conditions. Primary inclusions in the vein minerals and secondary inclusion trails in host wehrlite minerals contain abundant alkali-bearing phases (e.g., Na-K bearing carbonates, Mg-freudenbergite, Na-bearing apatite and phlogopite). The Sr-isotope composition of vein carbonates overlaps those of groundmass calcite from the Bultfontein kimberlite, as well as perovskite from the other kimberlites in the Kimberley area. Clinopyroxene and garnet in the host wehrlite are resorbed and have Si-rich reaction mantles where in contact with the carbonate-rich veins. Within some veins, the carbonates occur as droplet-like, globular segregations, separated from a similarly shaped Si-rich phase by a thin meniscus of Mg-magnetite. These textures are interpreted to represent immiscibility between carbonate and silicate melts. The preservation of reaction mantles, immiscibility textures and disequilibrium in the vein assemblage, suggests quenching, probably triggered by entrainment and rapid transport toward the Earth's surface in the host kimberlite magma. Based on the Sr-isotope systematics of vein carbonate minerals, and the close temporal relationship between carbonate-rich metasomatism and kimberlite magmatism, we suggest that the carbonate-rich vein assemblage was produced by the interaction between a melt genetically related to the Bultfontein kimberlite and wehrlitic mantle wall rock. If correct, this unique xenolith sample provides a rare snapshot of the assimilation processes that might characterise parental kimberlite melts during their ascent through the lithospheric mantle.
DS201611-2110
2016
Soltys, A.Giuliani, A., Soltys, A., Phillips, D., Kamenetsly, V.S., Maas, R., Geomann, K., Woodhead, J.D., Drysdale, R.N., Griffin, W.L.The final stages of kimberlite petrogenesis: petrography, mineral chemistry, melt inclusions and Sr-C-O isotope geochemistry of the Bultfontein kimberlite ( Kimberley, South Africa).Chemical Geology, in press available 15p.Africa, South AfricaDeposit - Bultfontein

Abstract: The petrogenesis of kimberlites commonly is obscured by interaction with hydrothermal fluids, including deuteric (late-magmatic) and/or groundwater components. To provide new constraints on the modification of kimberlite rocks during overprinting by such fluids and on the fractionation of kimberlite magmas during crystallisation, we have undertaken a detailed petrographic and geochemical study of a hypabyssal sample (BK) from the Bultfontein kimberlite (Kimberley, South Africa).
DS201707-1327
2017
Soltys, A.Giuliani, A., Soltys, A., Phillips, D., Kamenetsky, V.S., Maas, R., Goemann, K., Woodhead, J.D., Drysdale, R.N., Griffin, W.L.The final stages of kimberlite petrogenesis: petrography, mineral chemistry, melt inclusions and Sr-C-O isotope geochemistry of the Bultfontein kimberlite ( Kimberley, South Africa.Chemical Geology, Vol. 455, pp. 342-256.Africa, South Africadeposit - Bultfontein

Abstract: The petrogenesis of kimberlites is commonly obscured by interaction with hydrothermal fluids, including deuteric (late-magmatic) and/or groundwater components. To provide new constraints on the modification of kimberlite rocks during fluid interaction and the fractionation of kimberlite magmas during crystallisation, we have undertaken a detailed petrographic and geochemical study of a hypabyssal sample (BK) from the Bultfontein kimberlite (Kimberley, South Africa). Sample BK consists of abundant macrocrysts (> 1 mm) and (micro-) phenocrysts of olivine and lesser phlogopite, smaller grains of apatite, serpentinised monticellite, spinel, perovskite, phlogopite and ilmenite in a matrix of calcite, serpentine and dolomite. As in kimberlites worldwide, BK olivine grains consist of cores with variable Mg/Fe ratios, overgrown by rims that host inclusions of groundmass phases (spinel, perovskite, phlogopite) and have constant Mg/Fe, but variable Ni, Mn and Ca concentrations. Primary multiphase inclusions in the outer rims of olivine and in Fe-Ti-rich (‘MUM’) spinel are dominated by dolomite, calcite and alkali carbonates with lesser silicate and oxide minerals. Secondary inclusions in olivine host an assemblage of Na-K carbonates and chlorides. The primary inclusions are interpreted as crystallised alkali-Si-bearing Ca-Mg-rich carbonate melts, whereas secondary inclusions host Na-K-rich C-O-H-Cl fluids. In situ Sr-isotope analyses of groundmass calcite and perovskite reveal similar 87Sr/86Sr ratios to perovskite in the Bultfontein and the other Kimberley kimberlites, i.e. magmatic values. The ?18O composition of the BK bulk carbonate fraction is above the mantle range, whereas the ?13C values are similar to those of mantle-derived magmas. The occurrence of different generations of serpentine and occasional groundmass calcite with high 87Sr/86Sr, and elevated bulk carbonate ?18O values indicate that the kimberlite was overprinted by hydrothermal fluids, which probably included a significant groundwater component. Before this alteration the groundmass included calcite, monticellite, apatite and minor dolomite, phlogopite, spinel, perovskite and ilmenite. Inclusions of groundmass minerals in olivine rims and phlogopite phenocrysts show that olivine and phlogopite also belong to the magmatic assemblage. We therefore suggest that the crystallised kimberlite was produced by an alkali-bearing, phosphorus-rich, silica-dolomitic melt. The alkali-Si-bearing Ca-Mg-rich carbonate compositions of primary melt inclusions in the outer rims of olivine and in spinel grains with evolved compositions (MUM spinel) support formation of these melts after fractionation of abundant olivine, and probably other phases (e.g., ilmenite and chromite). Finally, the similarity between secondary inclusions in kimberlite olivine of this and other worldwide kimberlites and secondary inclusions in minerals of carbonatitic, mafic and felsic magmatic rocks, suggests trapping of residual Na-K-rich C-O-H-Cl fluids after groundmass crystallisation. These residual fluids may have persisted in pore spaces within the largely crystalline BK groundmass and subsequently mixed with larger volumes of external fluids, which triggered serpentine formation and localised carbonate recrystallisation.
DS201708-1768
2017
Soltys, A.Soltys, A.Apatite from Kimberley kimberlites ( South Africa): petrography and mineral chemistry.11th. International Kimberlite Conference, PosterAfrica, South Africadeposit - Kimberley

Abstract: The petrogenesis of kimberlites is commonly obscured by interaction with hydrothermal fluids, including deuteric (late-magmatic) and/or groundwater components. To provide new constraints on the modification of kimberlite rocks during fluid interaction and the fractionation of kimberlite magmas during crystallisation, we have undertaken a detailed petrographic and geochemical study of a hypabyssal sample (BK) from the Bultfontein kimberlite (Kimberley, South Africa). Sample BK consists of abundant macrocrysts (N1 mm) and (micro-) phenocrysts of olivine and lesser phlogopite, smaller grains of apatite, serpentinised monticellite, spinel, perovskite, phlogopite and ilmenite in a matrix of calcite, serpentine and dolomite. As in kimberlites worldwide, BK olivine grains consist of cores with variable Mg/Fe ratios, overgrown by rims that host inclusions of groundmass phases (spinel, perovskite, phlogopite) and have constant Mg/Fe, but variable Ni, Mn and Ca concentrations. Primary multiphase inclusions in the outer rims of olivine and in Fe-Ti-rich (‘MUM’) spinel are dominated by dolomite, calcite and alkali carbonates with lesser silicate and oxide minerals. Secondary inclusions in olivine host an assemblage of Na-K carbonates and chlorides. The primary inclusions are interpreted as crystallised alkali-Si-bearing Ca-Mg-rich carbonate melts, whereas secondary inclusions host Na-K-rich C-O-H-Cl fluids. In situ Sr-isotope analyses of groundmass calcite and perovskite reveal similar 87Sr/86Sr ratios to perovskite in the Bultfontein and the other Kimberley kimberlites, i.e. magmatic values. The ?18O composition of the BK bulk carbonate fraction is above the mantle range, whereas the ?13C values are similar to those of mantle-derived magmas. The occurrence of different generations of serpentine and occasional groundmass calcite with high 87Sr/86Sr, and elevated bulk carbonate ?18O values indicate that the kimberlite was overprinted by hydrothermal fluids, which probably included a significant groundwater component. Before this alteration the groundmass included calcite, monticellite, apatite and minor dolomite, phlogopite, spinel, perovskite and ilmenite. Inclusions of groundmass minerals in olivine rims and phlogopite phenocrysts show that olivine and phlogopite also belong to the magmatic assemblage. We therefore suggest that the crystallised kimberlite was produced by an alkali-bearing, phosphorus-rich, silica-dolomitic melt. The alkali-Si-bearing Ca-Mg-rich carbonate compositions of primary melt inclusions in the outer rims of olivine and in spinel grains with evolved compositions (MUM spinel) support formation of these melts after fractionation of abundant olivine, and probably other phases (e.g., ilmenite and chromite). Finally, the similarity between secondary inclusions in kimberlite olivine of this and other worldwide kimberlites and secondary inclusions in minerals of carbonatitic, mafic and felsic magmatic rocks, suggests trapping of residual Na-K-rich C-O-H-Cl fluids after groundmass crystallisation. These residual fluids may have persisted in pore spaces within the largely crystalline BK groundmass and subsequently mixed with larger volumes of external fluids, which triggered serpentine formation and localised carbonate recrystallisation.
DS201708-1769
2017
Soltys, A.Soltys, A.Primitive melt composition of the Bultfontein kimberlite ( South Africa).11th. International Kimberlite Conference, PosterAfrica, South Africadeposit - Bultfontein
DS201803-0477
2018
Soltys, A.Soltys, A., Giuliani, A., Phillips, D.A new approach to reconstructing the composition and evolution of kimberlite melts: a case study of the archetypal Bultfontein kimberlite ( Kimberley, South Africa).Lithos, in press available Africa, South Africadeposit - Bultfontein

Abstract: The compositions of kimberlite melts at depth and upon emplacement in the upper crust remain elusive. This can be attributed to the unquantified effects of multiple processes, such as alteration, assimilation, xenocryst contamination, and fractional crystallisation. The inability to accurately constrain the composition and physical properties of kimberlite melts prevents a comprehensive understanding of their petrogenesis. To improve constraints on the compositions of kimberlite melts, we have combined modal analysis including the discrimination of xenocrystic from magmatic phases, with mineral chemistry determinations to reconstruct a whole-rock composition. We apply this approach to a sample of “fresh” macrocrystic hypabyssal kimberlite (sample BK-1) from the Bultfontein mine (Kimberley, South Africa). The accuracy of this whole-rock reconstruction method is validated by the similarity between reconstructed and measured whole-rock compositions. A series of corrections are then applied to account for the effects of post-emplacement serpentinisation, pre-emplacement olivine crystallisation, and the inclusion and assimilation of mantle material. This approach permits discernment of melt compositions at different stages of kimberlite evolution. The primitive melt parental to the Bultfontein kimberlite is estimated to contain 17.4-19.0?wt% SiO2, 20.2-22.8?wt% MgO, 20.9-21.9?wt% CaO, 2.1-2.3?wt% P2O5, 1.2-1.4?wt% TiO2, 0.9-1.1?wt% Al2O3, and 0.6-0.7?wt% K2O, and has a Mg# of 83.4-84.4. Primary volatile contents (i.e., after an attempt to account for volatile loss) are tentatively estimated at ~2.1-2.2?wt% H2O and ~22.9-25.4?wt% CO2. This composition is deficient in SiO2, MgO and H2O, but enriched in CaO and CO2 compared with most previous estimates of primitive kimberlite melts. We suggest that the primitive melt parental to the Bultfontein kimberlite was a transitional silicate-carbonate melt, which was progressively enriched in SiO2, MgO, Al2O3, Cr2O3, and Na2O through the assimilation of lithospheric mantle material. Comparisons with experimentally produced low-degree melts of carbonated lherzolite indicate that the Bultfontein kimberlite could have formed by ~0.5% melting of asthenospheric mantle at ~6.0-8.6?GPa (i.e., ~190-285?km) and ~1400-1500?°C. The low calculated Na2O contents (<0.2?wt%), which are inconsistent with derivation from low-degree melting of lherzolite, suggest that an alkali-bearing, volatile-rich fluid was exsolved during ascent or released after emplacement, and subsequently removed.
DS201807-1527
2018
Soltys, A.Soltys, A., Giuliani, A., Phillips, D.Crystallisation sequence and magma evolution of the De Beers dyke ( Kimberley, South Africa).Mineralogy and Petrology, June 14, DOI:10.1007/ s00710-018 -0588-5, 16p.Africa, South Africadeposit - De Beers dyke

Abstract: We present petrographic and mineral chemical data for a suite of samples derived from the De Beers dyke, a contemporaneous, composite intrusion bordering the De Beers pipe (Kimberley, South Africa). Petrographic features and mineral compositions indicate the following stages in the evolution of this dyke: (1) production of antecrystic material by kimberlite-related metasomatism in the mantle (i.e., high Cr-Ti phlogopite); (2) entrainment of wall-rock material during ascent through the lithospheric mantle, including antecrysts; (3) early magmatic crystallisation of olivine (internal zones and subsequently rims), Cr-rich spinel, rutile, and magnesian ilmenite, probably on ascent to the surface; and (4) crystallisation of groundmass phases (i.e., olivine rinds, Fe-Ti-rich spinels, perovskite, apatite, monticellite, calcite micro-phenocrysts, kinoshitalite-phlogopite, barite, and baddeleyite) and the mesostasis (calcite, dolomite, and serpentine) on emplacement in the upper crust. Groundmass and mesostasis crystallisation likely forms a continuous sequence with deuteric/hydrothermal modification. The petrographic features, mineralogy, and mineral compositions of different units within the De Beers dyke are indistinguishable from one another, indicating a common petrogenesis. The compositions of antecrysts (i.e., high Cr-Ti phlogopite) and magmatic phases (e.g., olivine rims, magnesian ilmenite, and spinel) overlap those from the root zone intrusions of the main Kimberley pipes (i.e., Wesselton, De Beers, Bultfontein). However, the composition of these magmatic phases is distinct from those in ‘evolved’ intrusions of the Kimberley cluster (e.g., Benfontein, Wesselton water tunnel sills). Although the effects of syn-emplacement flow processes are evident (e.g., alignment of phases parallel to contacts), there is no evidence that the De Beers dyke has undergone significant pre-emplacement crystal fractionation (e.g., olivine, spinel, ilmenite). This study demonstrates the requirement for detailed petrographic and mineral chemical studies to assess whether individual intrusions are in fact ‘evolved’; and that dykes are not necessarily produced by differentiated magmas.
DS201812-2797
2018
Soltys, A.Das, H., Kobussen, A.F., Webb, K.J., Phillips, D., Maas, R., Soltys, A., Rayner, M.J., Howell, D.Bunder deposit: The Bunder diamond project, India: geology, geochemistry, and age of Saptarshi lamproite pipes.Society of Economic Geology Geoscience and Exploration of the Argyle, Bunder, Diavik, and Murowa Diamond Deposits, Special Publication no. 20, pp. 201-222.Indiadeposit - Bunder
DS201905-1033
2019
Soltys, A.Giuliani, A., Martin, L.A.J., Soltys,A., Griffin, W.L.Mantle like oxygen isotopes in kimberlites determined by in situ SIMS analyses of zoned olivine.Geochimica et Cosmochimica Acta, in press available, 19p.Africa, South Africa, Canada, South America, Brazildeposit - Lac de Gras, Paranaiba

Abstract: Kimberlites are the deepest melts produced on Earth that are erupted at the surface and can therefore provide unique insights into the composition and evolution of the mantle. Radiogenic isotopes provide ambiguous evidence for the occurrence of recycled crustal material in kimberlite sources. Oxygen isotopes can fractionate significantly only in the shallow crust, and thus represent a powerful tracer of subducted material in the sources of kimberlite. To constrain the oxygen isotope composition of kimberlite melts, we have examined olivine grains in eleven Cretaceous to Eocene archetypal kimberlites from southern Africa, Lac de Gras (Canada) and Alto Paranaiba (Brazil), which exhibit radiogenic isotope evidence for recycled crustal material in their sources including highly radiogenic Pb isotopes and Nd-Hf isotope compositions deviating below the mantle array. Olivine grains are commonly zoned between a mantle-derived xenocrystic core and one or more magmatic overgrowths, i.e. occasional internal zones, ubiquitous rims and rare rinds (moving outward from the core). The oxygen isotope composition of different olivine zones was determined in situ within separated olivine grains by secondary ion mass spectrometry (SIMS) after point selection using back-scattered electron (BSE) images combined with major and minor element analyses. With the exception of a few cores, the ?18O values of different olivine zones do not deviate from typical mantle olivine values of 5.18?±?0.28‰ (Mattey et al., 1994). There are no correlations between oxygen isotopes and major/minor element compositions for internal zones and rims from individual localities or in the entire dataset. This indicates that the oxygen isotope composition of kimberlite melts is not affected by melt differentiation to the point of olivine rim crystallisation. However, olivine rinds from the Koala kimberlite (Canada) display an inverse correlation between ?18O and Mn-Ca concentrations, with ?18O values extending below the mantle range, which is probably due to carbonate fractionation, CO2 degassing and/or assimilation of serpentine-rich material after kimberlite emplacement in the upper crust. The mantle-like ?18O composition of olivine internal zones and rims suggests that assimilation of mantle material and liberation of a CO2-rich phase during ascent in the mantle do not significantly modify the original ?18O signature of kimberlite melts. Modelling of oxygen isotope fractionation shows that up to 15 wt% of CO2 can be lost by kimberlites en route to the upper crust. Our results combined with mass balance calculations indicate that only a limited amount (<5-10 wt%) of recycled crustal material could occur in the source of kimberlites from southern Africa, Lac de Gras and Alto Paranaiba, or that the recycled material had an oxygen isotope composition similar to the mantle.
DS201905-1078
2019
Soltys, A.Soltys, A., Giuliani, A., Phillips, D.Crystallization sequence and magma evolution of the De Beers dyke ( Kimberley, South Africa).Mineralogy and Petrology, doi.org/10.1007/ s00710-018-0588-5 17p.Africa, South Africadeposit - De Beers dyke

Abstract: We present petrographic and mineral chemical data for a suite of samples derived from the De Beers dyke, a contemporaneous, composite intrusion bordering the De Beers pipe (Kimberley, South Africa). Petrographic features and mineral compositions indicate the following stages in the evolution of this dyke: (1) production of antecrystic material by kimberlite-related metasomatism in the mantle (i.e., high Cr-Ti phlogopite); (2) entrainment of wall-rock material during ascent through the lithospheric mantle, including antecrysts; (3) early magmatic crystallisation of olivine (internal zones and subsequently rims), Cr-rich spinel, rutile, and magnesian ilmenite, probably on ascent to the surface; and (4) crystallisation of groundmass phases (i.e., olivine rinds, Fe-Ti-rich spinels, perovskite, apatite, monticellite, calcite micro-phenocrysts, kinoshitalite-phlogopite, barite, and baddeleyite) and the mesostasis (calcite, dolomite, and serpentine) on emplacement in the upper crust. Groundmass and mesostasis crystallisation likely forms a continuous sequence with deuteric/hydrothermal modification. The petrographic features, mineralogy, and mineral compositions of different units within the De Beers dyke are indistinguishable from one another, indicating a common petrogenesis. The compositions of antecrysts (i.e., high Cr-Ti phlogopite) and magmatic phases (e.g., olivine rims, magnesian ilmenite, and spinel) overlap those from the root zone intrusions of the main Kimberley pipes (i.e., Wesselton, De Beers, Bultfontein). However, the composition of these magmatic phases is distinct from those in ‘evolved’ intrusions of the Kimberley cluster (e.g., Benfontein, Wesselton water tunnel sills). Although the effects of syn-emplacement flow processes are evident (e.g., alignment of phases parallel to contacts), there is no evidence that the De Beers dyke has undergone significant pre-emplacement crystal fractionation (e.g., olivine, spinel, ilmenite). This study demonstrates the requirement for detailed petrographic and mineral chemical studies to assess whether individual intrusions are in fact ‘evolved’; and that dykes are not necessarily produced by differentiated magmas.
DS201909-2090
2019
Soltys, A.Soltys, A., Giuliani, A., Phillips, D.Apatite geochemistry provides insights into the late magmatic evolution of kimberlites.Goldschmidt2019, 1p. AbstractAfrica, South Africadeposit - Kimberley

Abstract: The late evolution of kimberlite magmas, i.e., during and-following emplacement into the upper crust, remains a-controversial aspect of kimberlite petrogenesis. Likewise, it is-unclear whether or not there is a link between melt composition-and the emplacement mechanism of intrusive kimberlites (i.e.,-planar dykes/sills vs. irregular intrusions in the root zone of-pipes). Resolving these issues is hampered by the absence of-comparative studies of late-magmatic kimberlite phases (e.g.,-apatite, monticellite, mica) in dykes, sills, and root-zone-intrusions from the same locality.-Here we report petrographic and mineral-chemical results-for groundmass phases in samples of dykes, sills, and root zone-intrusions from the Kimberley kimberlites (South Africa).-Early crystalised phases (e.g., olivine, spinel) in dykes/sills and-root-zone intrusions have indistingushable compositions, and-hence crystallised from similar primitive melts. Conversely,-apatite major element compositions are variable and can-discriminate dykes/sills (i.e., low and constant Sr, with-increasing Si) from root zone intrusions (high but variable Sr,-low and constant Si). The Sr depletion in root zone apatite is-interpreted to represent fractional crystallisation of earlier-apatite, perovskite, and calcite from a broadly similar parental-melt. Silica enrichment of apatite from dykes/sills may be-attributed to the coupled incorporation of CO32- and Si into the-apatite structure, reflecting higher CO2 contents in the melts-that formed dykes/sills. CO2 enrichment in the dykes/sills is-consistent with petrographic obervations. Dykes/sills are-enriched in carbonates, may contain dolomite, and are depleted-in mica and monticellite compared to the groundmass of rootzone-kimberlites. This suggests the melts parental to-dykes/sills have a higher CO2/H2O ratio compared to those-parental to root zone intrusions. These two distinct melt-evolution paths cannot be due to crustal contamination before-emplacement because the Sr-isotope compositions of latecrystallised-carbonates are indistinguishable in dykes/sills and-root-zone intrusions. We speculate that CO2 is better retained-in dykes/sills due to a higher confining pressure (i.e., lack of-breakthrough to the surface).-
DS201910-2301
2019
Soltys, A.Soltys, A., Giuliani, A., Phillips, D.Apatite geochemistry provides insights into the Late magmatic evolution of kimberlites.Goldschmidt2019, 1p. AbstractMantlemagmatism

Abstract: The late evolution of kimberlite magmas, i.e., during and following emplacement into the upper crust, remains a controversial aspect of kimberlite petrogenesis. Likewise, it is unclear whether or not there is a link between melt composition and the emplacement mechanism of intrusive kimberlites (i.e., planar dykes/sills vs. irregular intrusions in the root zone of pipes). Resolving these issues is hampered by the absence of comparative studies of late-magmatic kimberlite phases (e.g., apatite, monticellite, mica) in dykes, sills, and root-zone intrusions from the same locality. Here we report petrographic and mineral-chemical results for groundmass phases in samples of dykes, sills, and root zone intrusions from the Kimberley kimberlites (South Africa). Early crystalised phases (e.g., olivine, spinel) in dykes/sills and root-zone intrusions have indistingushable compositions, and hence crystallised from similar primitive melts. Conversely, apatite major element compositions are variable and can discriminate dykes/sills (i.e., low and constant Sr, with increasing Si) from root zone intrusions (high but variable Sr, low and constant Si). The Sr depletion in root zone apatite is interpreted to represent fractional crystallisation of earlier apatite, perovskite, and calcite from a broadly similar parental melt. Silica enrichment of apatite from dykes/sills may be attributed to the coupled incorporation of CO32- and Si into the apatite structure, reflecting higher CO2 contents in the melts that formed dykes/sills. CO2 enrichment in the dykes/sills is consistent with petrographic obervations. Dykes/sills are enriched in carbonates, may contain dolomite, and are depleted in mica and monticellite compared to the groundmass of rootzone kimberlites. This suggests the melts parental to dykes/sills have a higher CO2/H2O ratio compared to those parental to root zone intrusions. These two distinct melt evolution paths cannot be due to crustal contamination before emplacement because the Sr-isotope compositions of latecrystallised carbonates are indistinguishable in dykes/sills and root-zone intrusions. We speculate that CO2 is better retained in dykes/sills due to a higher confining pressure (i.e., lack of breakthrough to the surface).
DS202005-0743
2020
Soltys, A.Kostrovitsky, S.I., Yakolev, D.A., Soltys, A., Ivanov, A.S., Matsyuk, S.S., Robles-Cruz, S.E.A genetic relationship between magnesian ilmenite and kimberlites of the Yakutian diamond fields.Ore Geology Reviews, Vol. 120, 16p. PdfRussia, Yakutiailmenite

Abstract: We present new major element geochemical data, and review the existing data for ilmenite macrocrysts, megacrysts, as well as ilmenite in mantle xenoliths from four diamondiferous kimberlite fields in the Yakutian province. This combined data set includes 10,874 analyses of ilmenite from 94 kimberlite pipes. In the studied samples we identify various different ilmenite compositional distributions (e.g., “Haggerty's parabola”, or “Step-like” trends in MgO-Cr2O3 bivariate space), which are common to all kimberlites from a given cluster, but the compositional distributions differ between clusters. We propose three stages of ilmenite crystallization: 1) Mg-Cr poor ilmenite crystallising from a primitive asthenospheric melt (the base of Haggerty's parabola on MgO-Cr2O3 plots). 2) This primitive asthenospheric melt was then modified by the partial assimilation of lithospheric material, which enriched the melt in MgO and Cr2O3 (left branch of Haggerty’s parabola). 3) Ilmenite subsequently underwent sub-solidus recrystallization in the presence of an evolved kimberlite melt under increasing oxygen fugacity (ƒO2) conditions (right branch of Haggerty’s parabola in MgO-Cr2O3 plots). Significant differences in the ilmenite compositional distribution between different kimberlite fields are the result of diverse conditions during subsequent ilmenite crystallization in a kimberlite melt ascending through the lithospheric mantle, which have different textures and compositions beneath the studied kimberlite fields. We propose that a TiO2 fluid formed due to immiscibility of an asthenospheric melt with low Cr and high Ti contents. This fluid infiltrated lithospheric mantle rocks forming Mg-ilmenite. These features indicate a genetic link between ilmenite and the host kimberlite melt.
DS202006-0950
2020
Soltys, A.Soltys, A., Giuliani, A., Phillips, D.Apatite compositions and groundmass mineralogy record divergent melt/fluid evolution trajectories in coherent kimberlites caused by differing emplacement mechanisms.Contributions to Mineralogy and Petrology, Vol. 175, 21p. PdfAfrica, South Africadeposit - Kimberley

Abstract: Kimberlites are pipe-like igneous bodies, consisting of a pyroclastic crater and diatreme, commonly underlain by coherent root-zone rocks, and with associated dyke/sill complexes. The processes that control the different modes of coherent kimberlite emplacement remain uncertain. In addition, late evolution of kimberlite melts during emplacement into the upper crust remains poorly constrained. Therefore, it is unclear whether there is a link between melt composition/evolution and the emplacement mechanism of coherent kimberlites (i.e. planar dykes/sills vs. irregular bodies in the root zone). An absence of comparative studies on late-stage magmatic phases across the different emplacement modes of coherent kimberlite from the same locality hamper resolution of these issues. Therefore, we report petrographic and mineral chemical data for groundmass apatite in samples of dyke, sill, and root-zone kimberlites from the Kimberley cluster (South Africa). Early crystallised phases (olivine, spinel, Mg-ilmenite) in dyke/sill and root-zone kimberlites have indistinguishable compositions, and hence crystallised from similar primitive melts. Conversely, apatite compositions are generally distinct in dyke/sill (low Sr, high and variable Si) and root-zone kimberlites (high and variable Sr, low Si). The Si enrichment of apatite in dykes/sills is attributed to the coupled incorporation of CO32? and SiO44? for PO43?, reflecting higher CO2 contents in their parental melts, and potentially higher Si contents due to the preferential crystallisation of carbonates over mica/monticellite. The low Sr contents of apatite in dyke/sill kimberlites reflect equilibrium with a (kimberlite) melt (i.e. DSr is close to unity for carbonate and silicate melts), whereas the higher Sr contents of apatite in root-zone kimberlites require crystallisation from, or overprinting by a H2O?±?CO2 fluid (significantly higher DSr). The relative enrichment of CO2 in kimberlite dykes/sills is evident from the abundance of carbonates, the presence of mesostasis dolomite and calcite phenocrysts in some samples, and concomitant reduced proportions of other groundmass phases (e.g. serpentine, mica, monticellite). During late alteration of kimberlite dykes/sills, monticellite is typically replaced by carbonates, whereas olivine and pleonaste are relatively stable, indicating the melts which form dykes/sills evolve to higher CO2/H2O ratios. It is unlikely that these two distinct evolutionary paths were caused by crustal contamination before or during near surface magma emplacement, because crustal assimilation is not recorded in the O and Sr isotopic composition of late crystallising olivine rinds or carbonates, respectively. We suggest that higher concentrations of CO2 are retained in kimberlite dykes/sills due to higher confining pressures (i.e. lack of breakthrough to the surface). In contrast, exsolution of CO2 from root-zone kimberlites increased melt H2O/CO2 ratios and promoted the crystallisation of mica and monticellite at the expense of dolomite and calcite. Apatite compositions have the potential to aid in the discrimination of kimberlites from lamproites (higher LREE, Sr, F, and S, lower Si contents) and carbonatites (higher LREE, F, Cl and S, lower Fe contents). However, the compositions of kimberlitic apatite overlap those from aillikites, probably due to similar late-stage melt compositions.
DS202007-1142
2020
Soltys, A.Giuliani, A., Pearson, D.G., Soltys, A., Dalton, H., Phillips, D., Foley, S.F., Lim, E.Kimberlite genesis from a common primary melt modified by lithospheric mantle assimilation.Science Advances, Vol. 6, eeaz0424Mantlemelting

Abstract: Quantifying the compositional evolution of mantle-derived melts from source to surface is fundamental for constraining the nature of primary melts and deep Earth composition. Despite abundant evidence for interaction between carbonate-rich melts, including diamondiferous kimberlites, and mantle wall rocks en route to surface, the effects of this interaction on melt compositions are poorly constrained. Here, we demonstrate a robust linear correlation between the Mg/Si ratios of kimberlites and their entrained mantle components and between Mg/Fe ratios of mantle-derived olivine cores and magmatic olivine rims in kimberlites worldwide. Combined with numerical modeling, these findings indicate that kimberlite melts with highly variable composition were broadly similar before lithosphere assimilation. This implies that kimberlites worldwide originated by partial melting of compositionally similar convective mantle sources under comparable physical conditions. We conclude that mantle assimilation markedly alters the major element composition of carbonate-rich melts and is a major process in the evolution of mantle-derived magmas.
DS202007-1178
2020
Soltys, A.Soltys, A., Giuliani, A,m Phillips, D., Kamenetsky, V.S.Kimberlite metasomatism of the lithosphere and the evolution of olivine in carbonate rich melts evidence from the Kimberley kimberlites ( South Africa).Journal of Petrology, 10.1093/petrology /egaa062/5857610 90p. PdfAfrica, South Africadeposit - Kimberley

Abstract: Olivine is the most abundant phase in kimberlites and is stable throughout most of the crystallisation sequence, thus providing an extensive record of kimberlite petrogenesis. To better constrain the composition, evolution, and source of kimberlites we present a detailed petrographic and geochemical study of olivine from multiple dyke, sill, and root zone kimberlites in the Kimberley cluster (South Africa). Olivine grains in these kimberlites are zoned, with a central core, a rim overgrowth, and occasionally an external rind. Additional ‘internal’ and ‘transitional’ zones may occur between the core and rim, and some samples of root zone kimberlites contain a late generation of high-Mg olivine in cross-cutting veins. Olivine records widespread pre-ascent (proto-)kimberlite metasomatism in the mantle including: (a) Relatively Fe-rich (Mg# <89) olivine cores interpreted to derive from the disaggregation of kimberlite-related megacrysts (20% of cores); (b) Mg-Ca-rich olivine cores (Mg# >89; >0.05?wt.% CaO) suggested to be sourced from neoblasts in sheared peridotites (25% of cores); (c) transitional zones between cores and rims probably formed by partial re-equilibration of xenocrysts (now cores) with a previous pulse of kimberlite melt (i.e., compositionally heterogeneous xenocrysts); and (d) olivine from the Wesselton water tunnel sills, internal zones (I), and low-Mg# rims, that crystallised from a kimberlite melt that underwent olivine fractionation within the shallow lithospheric mantle. Magmatic crystallisation begins with internal olivine zones (II), which are common but not ubiquitous in the Kimberley olivine. These zones are euhedral, contain rare inclusions of chromite, and have a higher Mg# (90.0 ± 0.5), NiO, and Cr2O3 contents, but are depleted in CaO compared to the rims. Internal olivine zones (II) are interpreted to crystallise from a primitive kimberlite melt during its ascent and transport of olivine toward the surface. Their compositions suggest assimilation of peridotitic material (particularly orthopyroxene) and potentially sulfides prior to or during crystallisation. Comparison of internal zones (II) with liquidus olivine from other mantle-derived carbonate-bearing magmas (i.e., orangeites, ultramafic lamprophyres, melilitites) show that low (100×) Mn/Fe (?1.2), very low Ca/Fe (?0.6), and moderate Ni/Mg ratios (?1.1) appear to be the hallmarks of olivine in melts derived from carbonate-bearing garnet-peridotite sources. Olivine rims display features indicative of magmatic crystallisation, which are typical of olivine rims in kimberlites worldwide - i.e. primary inclusions of chromite, Mg-ilmenite and rutile, homogeneous Mg# (88.8 ± 0.3), decreasing Ni and Cr, increasing Ca and Mn. Rinds and high-Mg olivine are characterised by extreme Mg-Ca-Mn enrichment and Ni depletion, and textural relationships indicate these zones represent replacement of pre-existing olivine, with some new crystallisation of rinds. These zones likely precipitated from evolved, oxidised, and relatively low-temperature kimberlite fluids after crustal emplacement. In summary, this study demonstrates the utility of combined petrography and olivine geochemistry to trace the evolution of kimberlite magmatic systems from early metasomatism of the lithospheric mantle by (proto-)kimberlite melts, to crystallisation at different depths en route to surface, and finally late-stage deuteric/hydrothermal fluid alteration processes after crustal emplacement.
DS202007-1179
2020
Soltys, A.Soltys, A., Giuliani, A., Phillips, D.Apatite compositions and groundmass mineralogy record divergent melt/fluid evolution trajectories in coherent kimberlites caused by differing emplacement mechanisms.Contributions to Mineralogy and Petrology, Vol. 175, 49 dor.org./10.1007 /s00410-020-01686-0Africa, South Africadeposit - Kimberley

Abstract: Kimberlites are pipe-like igneous bodies, consisting of a pyroclastic crater and diatreme, commonly underlain by coherent root-zone rocks, and with associated dyke/sill complexes. The processes that control the different modes of coherent kimberlite emplacement remain uncertain. In addition, late evolution of kimberlite melts during emplacement into the upper crust remains poorly constrained. Therefore, it is unclear whether there is a link between melt composition/evolution and the emplacement mechanism of coherent kimberlites (i.e. planar dykes/sills vs. irregular bodies in the root zone). An absence of comparative studies on late-stage magmatic phases across the different emplacement modes of coherent kimberlite from the same locality hamper resolution of these issues. Therefore, we report petrographic and mineral chemical data for groundmass apatite in samples of dyke, sill, and root-zone kimberlites from the Kimberley cluster (South Africa). Early crystallised phases (olivine, spinel, Mg-ilmenite) in dyke/sill and root-zone kimberlites have indistinguishable compositions, and hence crystallised from similar primitive melts. Conversely, apatite compositions are generally distinct in dyke/sill (low Sr, high and variable Si) and root-zone kimberlites (high and variable Sr, low Si). The Si enrichment of apatite in dykes/sills is attributed to the coupled incorporation of CO32? and SiO44? for PO43?, reflecting higher CO2 contents in their parental melts, and potentially higher Si contents due to the preferential crystallisation of carbonates over mica/monticellite. The low Sr contents of apatite in dyke/sill kimberlites reflect equilibrium with a (kimberlite) melt (i.e. DSr is close to unity for carbonate and silicate melts), whereas the higher Sr contents of apatite in root-zone kimberlites require crystallisation from, or overprinting by a H2O?±?CO2 fluid (significantly higher DSr). The relative enrichment of CO2 in kimberlite dykes/sills is evident from the abundance of carbonates, the presence of mesostasis dolomite and calcite phenocrysts in some samples, and concomitant reduced proportions of other groundmass phases (e.g. serpentine, mica, monticellite). During late alteration of kimberlite dykes/sills, monticellite is typically replaced by carbonates, whereas olivine and pleonaste are relatively stable, indicating the melts which form dykes/sills evolve to higher CO2/H2O ratios. It is unlikely that these two distinct evolutionary paths were caused by crustal contamination before or during near surface magma emplacement, because crustal assimilation is not recorded in the O and Sr isotopic composition of late crystallising olivine rinds or carbonates, respectively. We suggest that higher concentrations of CO2 are retained in kimberlite dykes/sills due to higher confining pressures (i.e. lack of breakthrough to the surface). In contrast, exsolution of CO2 from root-zone kimberlites increased melt H2O/CO2 ratios and promoted the crystallisation of mica and monticellite at the expense of dolomite and calcite. Apatite compositions have the potential to aid in the discrimination of kimberlites from lamproites (higher LREE, Sr, F, and S, lower Si contents) and carbonatites (higher LREE, F, Cl and S, lower Fe contents). However, the compositions of kimberlitic apatite overlap those from aillikites, probably due to similar late-stage melt compositions.
DS202008-1390
2020
Soltys, A.Fitzpaynek, A., Giuliani, A., Magalhaes, N., Soltys, A., Fiorentini, M., Farquhar, J.The petrology and sulphur istopic composition of sulphide and sulphate in the Kimberley kimberlites.Goldschmidt 2020, 1p. AbstractAfrica, South Africadeposit - Kimberley

Abstract: The petrology and bulk-rock sulphur isotopic compositions of kimberlite samples from four localities (Bultfontein, De Beers, Kimberley, Wesselton) of the archetypal Kimberley cluster, South Africa, were used to investigate the origin(s) of S in kimberlites and gain insights into the occurrence of recycled crustal material in the source of Mesozoic kimberlites. The samples, which show variable degrees of alteration, are all hypabyssal and were derived from coherent root-zones as well as dykes and sills. Typical sulphide minerals are Cu-Fe-Ni-sulphides with less common pyrite, galena, sphalerite, and djerfisherite. They occur in a variety of textural associations, for example as groundmass phases, secondary inclusions in olivine, inclusions in matrix phases (e.g., phlogopite), or in carbonate-serpentine segregations. Barite is the most commonly observed sulphate phase. Bulk-sample ?34SVCDT values of sulphides in fresh kimberlites, which mostly do not contain barite, vary from - 2.0 to -5.7 ‰. Slightly altered kimberlite samples, in which sulphides were generally associated with serpentine, returned somewhat higher bulk-sulphide ?34SVCDT (-3.8 to +1.1 ‰). One sample from the Wesselton Water Tunnel Sills complex contains abundant barite and pyrite in its groundmass, with the latter having ?34SVCDT (+0.2 to +1.9 ‰) similar to altered kimberlites. Two further altered samples returned ?34SVCDT values (-10.1 to -13.0 ‰) that suggest a contribution from the local country rocks (Dwyka shale: ?34SVCDT from -10.2 to -10.5 ‰). All samples have near-zero ?33S values, suggesting that material displaying mass-independent fractionation has not played an important role. The negative ?34SVCDT values of fresh kimberlites from Kimberley suggest the involvement of recycled crustal material in their source, which is consistent with radiogenic isotope compositions. Overall, it appears that most kimberlitic sulphide S isotopic compositions can be explained by the action of a few typical magmatic/hydrothermal processes.
DS202009-1664
2020
Soltys, A.Soltys, A., Giuliani, A., Phillips, D., Kamenetsky, V.S.Kimberlite metasomatism of the lithosphere and the evolution of olivine in carbonate rich melts - evidence from the Kimberley kimberlites ( South Africa).Journal of Petrology, in press available, 90p. PdfAfrica, South Africadeposit - Kimberley

Abstract: Olivine is the most abundant phase in kimberlites and is stable throughout most of the crystallization sequence, thus providing an extensive record of kimberlite petrogenesis. To better constrain the composition, evolution, and source of kimberlites we present a detailed petrographic and geochemical study of olivine from multiple dyke, sill, and root zone kimberlites in the Kimberley cluster (South Africa). Olivine grains in these kimberlites are zoned, with a central core, a rim overgrowth, and occasionally an external rind. Additional ‘internal’ and ‘transitional’ zones may occur between the core and rim, and some samples of root zone kimberlites contain a late generation of high-Mg olivine in cross-cutting veins. Olivine records widespread pre-ascent (proto-)kimberlite metasomatism in the mantle including the following features: (1) relatively Fe-rich (Mg# <89) olivine cores interpreted to derive from the disaggregation of kimberlite-related megacrysts (20?% of cores); (2) Mg-Ca-rich olivine cores (Mg# >89; >0•05?wt% CaO) suggested to be sourced from neoblasts in sheared peridotites (25?% of cores); (3) transitional zones between cores and rims probably formed by partial re-equilibration of xenocrysts (now cores) with a previous pulse of kimberlite melt (i.e. compositionally heterogeneous xenocrysts); (4) olivine from the Wesselton water tunnel sills, internal zones (I), and low-Mg# rims, which crystallized from a kimberlite melt that underwent olivine fractionation and stalled within the shallow lithospheric mantle. Magmatic crystallization begins with internal olivine zones (II), which are common but not ubiquitous in the Kimberley olivine. These zones are euhedral, contain rare inclusions of chromite, and have a higher Mg# (90•0 ± 0•5), NiO, and Cr2O3 contents, but are depleted in CaO compared with the rims. Internal olivine zones (II) are interpreted to crystallize from a primitive kimberlite melt during its ascent and transport of olivine toward the surface. Their compositions suggest assimilation of peridotitic material (particularly orthopyroxene) and potentially sulfides prior to or during crystallization. Comparison of internal zones (II) with liquidus olivine from other mantle-derived carbonate-bearing magmas (i.e. orangeites, ultramafic lamprophyres, melilitites) shows that low (100×) Mn/Fe (?1•2), very low Ca/Fe (?0•6), and moderate Ni/Mg ratios (?1•1) appear to be the hallmarks of olivine in melts derived from carbonate-bearing garnet-peridotite sources. Olivine rims display features indicative of magmatic crystallization, which are typical of olivine rims in kimberlites worldwide; that is, primary inclusions of chromite, Mg-ilmenite and rutile, homogeneous Mg# (88•8 ± 0•3), decreasing Ni and Cr, and increasing Ca and Mn. Rinds and high-Mg olivine are characterized by extreme Mg-Ca-Mn enrichment and Ni depletion, and textural relationships indicate that these zones represent replacement of pre-existing olivine, with some new crystallization of rinds. These zones probably precipitated from evolved, oxidized, and relatively low-temperature kimberlite fluids after crustal emplacement. In summary, this study demonstrates the utility of combined petrography and olivine geochemistry to trace the evolution of kimberlite magmatic systems from early metasomatism of the lithospheric mantle by (proto-)kimberlite melts, to crystallization at different depths en route to surface, and finally late-stage deuteric or hydrothermal fluid alteration after crustal emplacement.
DS2001-1104
2001
Soltzer, R.L.Soltzer, R.L., Van der Hilst, R.D., Karason, H.Comparing P and S wave heterogeneity in the mantleGeophysical Research Letters, Vol. 28, No. 7, April 1, pp.1335-8.MantleHeterogeneity
DS200812-0597
2008
Solvaceva, L.A.V.A.Kostrovitsky, S.A.I.A., Alymova, N.A., Yakolev, D.A.A., Solvaceva, L.A.V.A., Gornova, M.A.A.A.Origin of garnet megacrysts from kimberlites.Doklady Earth Sciences, Vol. 420, 1, pp. 636-640.RussiaPetrology
DS1995-2117
1995
Solyanik, V.A.Zalishchak, B.L., Solyanik, V.A.The far eastern provinces of kimberlites, lamproites, nephelinites.alkaline basaltoids, Hyperbasites ...Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 681.Russia, Primoye, Khabarovsk, Amur, Sakhalin IslandLamproites, Khanka, Sikhote- Alin, Anjui
DS201904-0765
2018
Solyanik, V.A.Pakhomova, V.A., Fedoseev, D.G., Kultenko, S.Y., Karabtsov, A.A., Tishkina, V.B., Solyanik, V.A., Kamynin, V.A.Synthetic moissanite coated with diamond film imitating rough diamond.Gems & Gemology, Vol. 54, 4, 4p.Russiamoissanite
DS1989-0833
1989
Solymos, K.Kubovics, I., Szabo, C., Solymos, K.Geochemistry of phlogophites in ultramafic xenoliths of lamprophyre dikes (Alcusutdoboz Hungary)Neues Jahrbuch Fur Mineralogie Abhandlungen, Vol. 161, No. 2, October pp. 171-191HungaryGeochemistry, Lamprophyres
DS1989-1431
1989
Somanas, C.Somanas, C., Knapp, R.W., Yarger, H.L., Steeples, D.W.Geophysical model of the Midcontinent geophysical anomaly in northeasternKansasKansas Geological Survey, Bulletin. 226, pp. 215-228KansasGeophysics, Midcontinent
DS201801-0066
2017
Somani, O.P.Somani, O.P.Rare earth element applications, market outlook and Indian perspectives.Carbonatite-alkaline rocks and associated mineral deposits , Dec. 8-11, abstract p.41-42.Indiarare earths

Abstract: Rare earth elements (REE) are a group of seventeen chemical elements that occur together in the periodic table. The group consists of yttrium and the 15 lanthanide elements (lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium). Promethium does not occur in nature because it is highly and the only lanthanide which has no stable (or even long-lived) isotopes. The most stable isotope of the element is Promethium-145, a half-life of 17.7 years. Due to its very less half-life most of the Promethium might have exhausted within first 10,000 years of formation of Earth. Scandium is found in most rare earth element deposits and is sometimes classified as a rare earth element. The rare earth elements are all metals, and the group is often referred to as the "rare earth metals." These metals have many similar properties, and that often causes them to be found together in geologic deposits. They are also referred to as "rare earth oxides" because many of them are typically sold as oxide compounds. The rare earths elements are classified into two groups; Cerium Group and Yttrium group, the former consists of light rare earths ( Sc, La, Ce, Nd, Pr, Pm, Sm and Eu ). The later is composed of (Y, Gd,Tb, Dy, Ho, Er, Tm, Yb and Lu). In nature the minerals of cerium group are different then the Yttrium group. The most common light rare earth minerals are monazite and bastnasite and for the heavy rare earth element the mineral is xenotime. Rare earth elements are not as "rare" as their name implies. Thulium and lutetium are the two least abundant rare earth elements - but they each have an average crustal abundance that is nearly 200 times greater than the crustal abundance of gold. However, these metals are very difficult to mine because it is unusual to find them in concentrations high enough for economical extraction. The most abundant rare earth elements are cerium, yttrium, lanthanum and neodymium. They have average crustal abundances that are similar to commonly used industrial metals such as chromium, nickel, zinc, molybdenum, tin, tungsten, and lead. Again, they are rarely found in extractable levels. Because of their unique magnetic, luminescent, and electrochemical properties, these elements help make many technologies perform with reduced weight, emissions, and energy consumption, and give them greater efficiency, performance, miniaturization, speed, durability, and thermal stability. Rare earth-enabled products and technologies help to fuel global economic growth, maintain high standards of living, and save lives. Rare earth elements are used extensively in aerospace and defense, health care, clean energy, electronics, transportation and vehicles, catalysts, polishing industry etc. Global resources of rare earths are about 120 Mt, China tops with 44 Mt, Vietnam and Brazil both 22Mt each, Russia 18 Mt, India 6.9 Mt, Australia 3.4 Mt, USA 1.4 Mt, Greenland 1.5 Mt, Malawi, 0.136 Mt, South Africa 0.86 Mt. The major producers today are China and Australia. China producing about 105,000 tons and Australia, 14000 tons, Russia, 3000 tons, India, 1700 tons, Brazil, 1100 tons, Thailand 800 tons, Malaysia, 300 tons( based on 2016 data). In 2016, excess global supply caused prices for many rare-earth compounds and metals to decline, and China continued to dominate the global supply. In China, the rare-earth mining production quota for 2016 was set at 105,000 tons, unchanged from 2015.The major reason of price decline was the illegal mining of rare earths in China which cause pollution and other financial losses. Now China is clamping down on mining as part of a campaign to tackle pollution and tighten control of its massive industrial complex. Various measures to curb production have already driven up prices of aluminum, steel, and now rare earths. Praseodymium-neodymium oxide, a raw material for the metal, has almost doubled this year, Neodymium surged by nearly a third in August alone and is up 81 percent in 2017. Demand for some rare earths may exceed supply in the second half after the crackdown on illegal mines. The global demand for automobiles, consumer electronics, energy-efficient lighting, permanent magnets and catalysts is expected to rise rapidly over the next decade. Rare earth magnet demand is expected to increase, as is the demand for rechargeable batteries. New developments in medical technology are expected to increase the use of surgical lasers, magnetic resonance imaging, and positron emission tomography scintillation detectors. Rare earth elements are heavily used in all of these industries, so the demand for them should remain high. So far EVs and renewable energy from clean technology point of view are concerned the rare earths join with niche metals including lithium and cobalt as beneficiaries of rapid growth in the electric vehicle industry and in renewable energy in the form of permanent magnets used in gearless turbines. By 2020, the REE demand in EVs will increase from 2000 tons per year to 7000 tons per year in 2020 and 12000 tons by 2024. In India, Indian Rare Earth Ltd is planning to produce 10,000 tons REO per year. The carbonatite hosted REE deposit with non-monazite sources has also been identified in Barmer district of Rajasthan.
DS201512-1920
2015
Somani, R.Gokhale, M., Madhura, Somani, R., RakeshFullerenes: chemistry and its applications.Mini-Reviews in Organic Chemistry, Vol. 12, 4, pp. 355-366.TechnologyFullerenes

Abstract: Fullerenes being allotropes of carbon, have been considered as new class of molecules. Unlike diamond and graphite, this is made up of hollow carbon cage structure. The idea of spheroidal cage structures of C60 arose from construction of geodesic domes made by renowned architect Buckminster Fuller. Although fullerenes have low solubility in physiological media they finds promising biological applications. The photo, electrochemical and physical properties of C60 and other fullerene derivatives finds applications in medical fields. The ability of fullerenes to fit inside the hydrophobic cavity of HIV proteases makes them potential inhibitor for substrates to catalytic active site of enzyme. It possesses radical scavenging and antioxidant property. At the same time, when it exposed to light it can form singlet oxygen in high quantum yields which with direct electron transfer from excited state of fullerenes and DNA bases finally results in cleavage of DNA. The fullerenes are also used as a carrier for gene and drug delivery system. The associated low toxicity of fullerenes is sufficient to attract the researchers for investigation of these interesting molecules.
DS201907-1565
2019
Sombini, G.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
DS201706-1076
2017
Somers, A.M.Harmon, R.S., Hark, R.R., Throckmorton, C.S., Rankey, E.C., Wise, M.A., Somers, A.M., Collins, L.M.Geochemical fingerprinting by handheld laser-induced breakdown spectroscopy. (LIBS)Geostandards and Geoanalytical Research, in press availableTechnologyspectroscopy

Abstract: A broad suite of geological materials were studied a using a handheld laser-induced breakdown spectroscopy (LIBS) instrument. Because LIBS is simultaneously sensitive to all elements, the full broadband emission spectrum recorded from a single laser shot provides a ‘chemical fingerprint’ of any material - solid, liquid or gas. The distinguishing chemical characteristics of the samples analysed were identified through principal component analysis (PCA), which demonstrates how this technique for statistical analysis can be used to identify spectral differences between similar sample types based on minor and trace constituents. Partial least squares discriminant analysis (PLSDA) was used to distinguish and classify the materials, with excellent discrimination achieved for all sample types. This study illustrates through four selected examples involving carbonate minerals and rocks, the oxide mineral pair columbite-tantalite, the silicate mineral garnet and native gold how portable, handheld LIBS analysers can be used as a tool for real-time chemical analysis under simulated field conditions for element or mineral identification plus such applications as stratigraphic correlation, provenance determination and natural resources exploration.
DS202106-0949
2021
Somers, A.M.Lawley, C.J.M., Somers, A.M., Kjarsgaard, B.A.Rapid geochemical imaging of rocks and minerals with handheld laser induced breakdown spectroscopy. ( LIBS)Journal of Geochemical Exploration, Vol. 222, 106694, 16p. PdfCanada, Nunavutdeposit - Jericho, Muskox

Abstract: Geochemical imaging is a powerful tool for unravelling the complex geological histories of rocks and minerals. However, its applications have until recently been restricted to geological research in a lab environment due to the cost and size of conventional instrumentation, long analysis times, and extensive sample preparation for some methods. Herein we present a rapid, qualitative geochemical imaging method for rocks and minerals using handheld LIBS. Analyses were completed directly on sawed drill core surfaces for a suite of kimberlite-hosted mantle xenoliths (Jericho and Muskox kimberlites, Nunavut, Canada). Semi-automated LIBS spectral processing following a new open-source workflow allows stitching of multiple small-area maps (each approximately 3 × 3 mm that take 2-3 min to complete) to produce cm-scale geochemical images of variably altered mantle xenolith samples (total data acquisition in 1-2 h). Replicate analyses of a Znsingle bondAl alloy reference material (NZA-1; CANMET) that were undertaken during standard-sample bracketing suggests that the relative standard deviation (RSD) is typically 15-20% for sum-normalized emission intensities above the estimated background. We demonstrate with open-source machine learning tools how qualitative LIBS spectral data can be converted to Feature-Of-Interest (FOI) maps to distinguish a variety of metasomatic and alteration features (e.g., Cr-diopside, kelyphite rims on pyrope garnet, and calcite veinlets) from the primary mantle mineralogy (e.g., olivine and orthopyroxene). Our results further demonstrate that the resolution of handheld LIBS-based geochemical imaging is sufficient to map veinlets and grain boundaries lined with metasomatic minerals. The LIBS approach is particularly sensitive for mapping the microscale distribution of elements with low atomic number (e.g., Li and Na). These light elements are difficult to detect at low concentrations with other handheld and field-portable technologies, but represent important geochemical tracers of hydrothermal and magmatic processes. Rapid LIBS mapping thus represents an emerging geochemical imaging tool for unravelling the complex geological history of rocks and minerals in the field with minimal to no sample preparation.
DS1996-0405
1996
Somerton, I.Eberle, D., Hutchins, D.G., Rebbeck, R.J., Somerton, I.Compilation of the Namibian airborne magnetic surveys: procedures, problem sand results.Journal of African Earth Sciences, Vol. 22, No. 2, Feb. pp. 191-206.NamibiaGeophysics -magnetics, Compilation
DS201806-1219
2018
Somerville, I.Dai, L., Li, S., Li, Z-H., Somerville, I., Santosh, M.Dynamics of exhumation and deformation of HP-UHP orogens in double subduction collision systems: numerical modeling and implications for the Western Dabie Orogen.Earth Science Reviews, Vol. 182, pp. 68-84.ChinaUHP

Abstract: The dynamics of formation and exhumation of high-pressure (HP) and ultra-high pressure (UHP) metamorphic orogens in double subduction-collision zones remain enigmatic. Here we employ two-dimensional thermo-mechanical numerical models to gain insights on the exhumation of HP-UHP metamorphic rocks, as well as their deformation during the collision of a micro-continent with pro- and retro-continental margins along two subduction zones. A three-stage collisional process with different convergence velocities is tested. In the initial collisional stage, a fold-and-thrust belt and locally rootless superimposed folds are developed in the micro-continent and subduction channel, respectively. In the second (exhumation) stage of HP-UHP rocks, a faster convergence model results in upwelling of the asthenosphere, which further leads to a detachment between the crust and lithospheric mantle of the micro-continent. A slower convergence model results in rapid exhumation of HP-UHP rocks along the north subduction channel and a typical piggy-back thrusting structure in the micro-continent. A non-convergence model produces a slab tear-off, leading to the rebound of residual lithosphere of the micro-continent. In the third and final stage, a series of back and ramp thrusts are formed in the micro-continent with the pro-continent re-subducted. Based on an analogy of our numerical results with the Western Dabie Orogen (WDO), we suggest that: (1) slab tear-off results in a rebound of residual lithosphere, which controls the two-stage syn-collisional exhumation process of HP-UHP rocks in the WDO; and (2) in contrast to the single subduction-collision system, the exhumation range of the partially molten rocks with lower viscosity and density is restricted to a specific region of the micro-continent by the Mianlue and Shangdan subduction zones, which generated the complex deformation features in the WDO.
DS1997-1084
1997
Somerville, R.C.J.Somerville, R.C.J.The forgiving air... understanding environmental changeUniversity of of California Press, $ 22.00GlobalBook - ad, Environment - air
DS200812-1096
2008
Sommer, A.P.Sommer, A.P., Zhu, D., Fecht, H.J.Genesis on diamonds.Crystal Growth & Design, Vol. 8, 8, pp.2628-2629.TechnologyDiamond genesis
DS2003-0876
2003
Sommer, H.Markl, G., Abart, R., Vennemann, T., Sommer, H.Mid-crustal metasomatic reaction veins in a spinel peridotiteJournal of Petrology, Vol. 44, 6, pp. 1097-1120.MantleBlank
DS2003-1312
2003
Sommer, H.Sommer, H., Kroner, A., Hauzenberger, C., Muhongo, S., Wingate, M.T.Metamorphic petrology and zircon geochronology of high grade rocks from the centralJournal of Metamorphic Geology, Vol. 21, 9, pp. 915-934.TanzaniaGeochronology - not specific to diamonds
DS200412-1226
2003
Sommer, H.Markl, G., Abart, R., Vennemann, T., Sommer, H.Mid-crustal metasomatic reaction veins in a spinel peridotite.Journal of Petrology, Vol. 44, 6, pp. 1097-1120.MantleMetasomatism
DS200412-1877
2003
Sommer, H.Sommer, H., Kroner, A., Hauzenberger, C., Muhongo, S., Wingate, M.T.Metamorphic petrology and zircon geochronology of high grade rocks from the central Mozambique belt of Tanzania: crustal recycliJournal of Metamorphic Geology, Vol. 21, 9, pp. 915-934.Africa, TanzaniaGeochronology - not specific to diamonds
DS200712-1015
2007
Sommer, H.Sommer, H., Regenauer-Lieb, K.R., Hauzenberger, C.Diamonds, xenoliths and kimberlites: a window in the Earth's mantle. UNESCO IGCP 557.Plates, Plumes, and Paradigms, 1p. abstract p. A954.MantleE and P type diamonds
DS200812-1097
2008
Sommer, H.Sommer, H., Regenauer Lieb, K., Hauzenberger, C., Gasharova, B.Rapid uplift of the Jwaneng kimberlite, south Botswana: caused by mantle metasomatism and documented by OH diffusion profiles in garnet from eclogitic xenoliths.Goldschmidt Conference 2008, Abstract p.A882.Africa, BotswanaDeposit - Jwaneng
DS200812-1098
2008
Sommer, H.Sommer, H., Regenauerlieb, K., Gasharova, B., Siret, D.Grain boundaries: a possible water reservoir in the Earth's mantle?Mineralogy and Petrology, Vol. 94, 1-2, pp. 1-8.MantleWater
DS200912-0595
2009
Sommer, H.Potgeiter, J., Sommer, H., Regenauer-Lieb, K., Gasharova, B., Purchase, M.OH and CO2 diffusion profiles in garnets from eclogite xenoliths from the Rovic diamond mine, South Africa. ( Unesco IGCP 557)Goldschmidt Conference 2009, p. A1046 Abstract.Africa, South AfricaDeposit - Rovic
DS200912-0596
2008
Sommer, H.Potgeter, J., Sommer, H., Regenauer-Lieb, K., Gasharova, B.Oh and CO2 diffusion profiles in garnets from eclogitic xenoliths from the Victor mine, South Africa.American Geological Union, Fall meeting Dec. 15-19, Eos Trans. Vol. 89, no. 53, meeting supplement, 1p. abstractAfrica, South AfricaDeposit - Roberts Victor
DS200912-0602
2008
Sommer, H.Purchase, M., Sommer, H.Diffusion profiles of OH towards melt inclusions in garnets in lherzolite xenoliths from the Victor diamond mine.American Geological Union, Fall meeting Dec. 15-19, Eos Trans. Vol. 89, no. 53, meeting supplement, 1p. abstractAfrica, South AfricaDeposit - Roberts Victor
DS200912-0603
2009
Sommer, H.Purchase, M., Sommer, H., Regenauer-Lieb, K., Gasharova, B., Potgeiter, J.OH partitioning coefficient between garnets and melt inclusions in lherzolite xenoliths from the Kimberley diamond mine, South Africa.Goldschmidt Conference 2009, p. A1059 Abstract.Africa, South AfricaDeposit - Kimberley
DS200912-0622
2008
Sommer, H.Regenauer-Lieb, K., Sommer, H., Gaede, H., Gaede, O.Weertman cracks and the fast extraction of diamonds from the Earth's mantle.American Geological Union, Fall meeting Dec. 15-19, Eos Trans. Vol. 89, no. 53, meeting supplement, 1p. abstractAfrica, BotswanaDeposit - Jwaneng
DS200912-0713
2009
Sommer, H.Sommer, H.Wet low angle subduction: a possible mechanism belwo the Tanzania craton 2 Ga ago.Mineralogy and Petrology, Vol. 96, 1-2, May pp. 113-120.Africa, TanzaniaKimberlite
DS200912-0714
2009
Sommer, H.Sommer, H.Wet low angle subduction: a possible mechanism below the Tanzanian Craton 2 Ga ago.Mineralogy and Petrology, Vol. 96, pp. 112-120.Africa, TanzaniaSubduction
DS200912-0715
2009
Sommer, H.Sommer, H., Regenauer-Lieb, K., Gaede, O.Weertman cracks and the near sonic extraction of diamonds from the Earth's mantle.Goldschmidt Conference 2009, p. A1249 Abstract.Africa, BotswanaDeposit - Jwaneng
DS201112-0816
2011
Sommer, H.Potgeiter, J., Sommer, H., Regenauer-Lieb, K., Jung, H., Gasharova, B.The formation of microdiamonds in cracks caused by C-O-H rich fluid under medium to low pressure conditions.Goldschmidt Conference 2011, abstract p.1662.Africa, South AfricaVictor
DS201112-0836
2011
Sommer, H.Purchase, M., Sommer, H., Regenauer-Lieb, K., Jung, H., Gasharova, B.Coexistent aqueous fluid phase and melt in lherzolites from Bultfontein, South Africa.Goldschmidt Conference 2011, abstract p.1675.Africa, South AfricaDeposit - Bultfontein
DS201112-0986
2011
Sommer, H.Sommer, H., Regenauer-Lieb, K., Gaede, O., Jung, H., Gasharova, B.WEERTMAN cracks: a possible mechanism for near sonic speed diamond extraction from the Earth's mantle.Goldschmidt Conference 2011, abstract p.1908.MantleTransport for diamond bearing kimberlite melts
DS201212-0692
2012
Sommer, H.Sommer, H., Regenauer-Lieb, K., Gasharova, B., Jung, H.The formation of volcanic centers at the Colorado Plateau as a result of the passage of aqueous fluid through the oceanic lithospher and the subcontinental mantle" new implications for the planetary water cycle in the western United States.Journal of Geodynamics, Vol. 61, Oct. pp. 154-171.United States, Colorado PlateauVolcanism
DS201412-0870
2013
Sommer, H.Sommer, H., Wan,Y., Kroner, A., Xie, H., Jacob, D.E.Shrimp zircon ages and petrology of lower crustal granulite xenoliths from the Letseng-La-Terae kimberlite, Lesotho: further evidence for a Namaquanatal connection.South Africa Journal of Geology, Vol. 116, 2, pp. 183-198.Africa, LesothoDeposit - Letseng
DS201705-0877
2017
Sommer, H.Sommer, H., Jacob, D.E., Stern, R.A., Petts, D., Mattey, D.P., Pearson, D.G.Fluid induced transition from banded kyanite to bimineralic eclogite and implications for the evolution of cratons.Geochimica et Cosmochimica Acta, in press available 55p.Africa, South AfricaDeposit - Roberts Victor

Abstract: Heterogeneous, modally banded kyanite-bearing and bimineralic eclogites from the lithospheric mantle, collected at the Roberts Victor Diamond mine (South Africa), show a reaction texture in which kyanite is consumed. Geothermobarometric calculations using measured mineral compositions in Perple_X allowed the construction of a P-T path showing a steep, cool prograde metamorphic gradient of 2 °C/km to reach peak conditions of 5.8 GPa and 890 °C for the kyanite eclogite. The kyanite-out reaction formed bimineralic eclogite and is probably an integral part of the mineralogical evolution of most archetypal bimineralic eclogites at Roberts Victor and potentially elsewhere. The kyanite-out reaction occured at close to peak pressure (5.3 GPa) and was associated with a rise in temperature to 1380 °C. Mass balance calculations show that upon breakdown, the kyanite component is fully accommodated in garnet and omphacite via a reaction system with low water fugacity that required restricted fluid influx from metasomatic sources. The ?18O values of garnets are consistently higher than normal mantle values. Each sample has its characteristic trend of ?18O variance between garnets in the kyanite-bearing sections and those in the bimineralic parts covering a range between 5.1‰ and 6.8‰. No systematic change in O-isotope signature exists across the sample population. Differences in garnet trace element signatures between differing lithologies in the eclogites are significant. Grossular-rich garnets coexisting with kyanite have strong positive Eu-anomalies and low Gd/Yb ratios, while more pyrope-rich garnets in the bimineralic sections have lost their positive Eu-anomaly, have higher Gd/Yb ratios and generally higher heavy rare earth element contents. Garnets in the original kyanite-bearing portions thus reflect the provenance of the rocks as metamorphosed gabbros/troctolites. The kyanite-out reaction was most likely triggered by a heating event in the subcratonic lithosphere. As kyanite contains around 100 ppm of H2O it is suggested that the kyanite-out reaction, once initiated by heating and restricted metasomatic influx, was promoted by the release of water contained in the kyanite. The steep (high-P low-T) prograde P-T path defining rapid compression at low heating rates is atypical for subduction transport of eclogites into the lithospheric mantle. Such a trajectory is best explained in a model where strong lateral compression forces eclogites downward to higher pressures, supporting models of cratonic lithosphere formation by lateral collision and compression.
DS201709-2056
2017
Sommer, H.Sommer, H., Jacob, D.E., Stern, R.A., Petts, D., Mattey, D.P., Pearson, D.G.Fluid induced transition from banded kyanite to bimineralic eclogite and implications for the evolution of cratons.Goldschmidt Conference, abstract 1p.Africa, South Africadeposit - Roberts Victor

Abstract: Heterogeneous, modally banded kyanite-bearing and bimineralic eclogites from the lithospheric mantle, collected at the Roberts Victor Diamond mine (South Africa), show a reaction texture in which kyanite is consumed. Geothermobarometric calculations using measured mineral compositions in Perple_X allowed the construction of a P-T path showing a steep, cool prograde metamorphic gradient of 2 °C/km to reach peak conditions of 5.8 GPa and 890 °C for the kyanite eclogite. The kyanite-out reaction formed bimineralic eclogite and is probably an integral part of the mineralogical evolution of most archetypal bimineralic eclogites at Roberts Victor and potentially elsewhere. The kyanite-out reaction occured at close to peak pressure (5.3 GPa) and was associated with a rise in temperature to 1380 °C. Mass balance calculations show that upon breakdown, the kyanite component is fully accommodated in garnet and omphacite via a reaction system with low water fugacity that required restricted fluid influx from metasomatic sources. The ?18O values of garnets are consistently higher than normal mantle values. Each sample has its characteristic trend of ?18O variance between garnets in the kyanite-bearing sections and those in the bimineralic parts covering a range between 5.1‰ and 6.8‰. No systematic change in O-isotope signature exists across the sample population. Differences in garnet trace element signatures between differing lithologies in the eclogites are significant. Grossular-rich garnets coexisting with kyanite have strong positive Eu-anomalies and low Gd/Yb ratios, while more pyrope-rich garnets in the bimineralic sections have lost their positive Eu-anomaly, have higher Gd/Yb ratios and generally higher heavy rare earth element contents. Garnets in the original kyanite-bearing portions thus reflect the provenance of the rocks as metamorphosed gabbros/troctolites. The kyanite-out reaction was most likely triggered by a heating event in the subcratonic lithosphere. As kyanite contains around 100 ppm of H2O it is suggested that the kyanite-out reaction, once initiated by heating and restricted metasomatic influx, was promoted by the release of water contained in the kyanite. The steep (high-P low-T) prograde P-T path defining rapid compression at low heating rates is atypical for subduction transport of eclogites into the lithospheric mantle. Such a trajectory is best explained in a model where strong lateral compression forces eclogites downward to higher pressures, supporting models of cratonic lithosphere formation by lateral collision and compression.
DS200512-0113
2005
SomogyiBrenker, F.E., Vincze, L., Velemans, Nasdala, Stachel, Vollmer, Kersten, Somogyi, Adams, Joswig, HarrisDetection of a Ca rich lithology in the Earth's deep ( >300km) convecting mantle.Earth and Planetary Science Letters, Vol. 236, 3-4, pp. 579-587.Africa, GuineaKankan, diamond inclusions, spectroscopy
DS201012-0019
2009
SomovAshchepkov, I.V., Rotman, Nossyko, Somov, Shimupi, Vladykin, Palessky, Saprykin, KhmelnikovaComposition and thermal structure of mantle beneath the western part of the Congo-Kasai craton according to xenocrysts from Angola kimberlites.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., p. 158-180.Africa, AngolaGeothermometry
DS200512-0914
2004
Somov, S.V.Rotman, A.Y., Ganga, J., Nosyko, S.F., Shimupi, J., Zintchouk, N.N., Somov, S.V.Kimberlites of Angola: structural tectonic position and geology.Deep seated magmatism, its sources and their relation to plume processes., pp. 178-193.Africa, AngolaTectonics
DS201212-0035
2012
Somov, S.V.Ashchepkov, I.V., Rotmas, A.Y., Somov, S.V.Composition and thermal structure of the lithospheric mantle beneath kimberlite pipes from the Catoca cluster, Angola.Tectonophysics, Vol. 530-531, pp. 128-151.Africa, AngolaDeposit - Catoca
DS201112-0784
2011
Somov, V.Pervov, S., Somov, V., Korshunov, A.V., Dulapchii, E.V.The Catoca kimberlite pipe, Republic of Angola: a paleovolcanological model.Geology of Ore Deposits, Vol. 53, no. 4, pp. 295-308.Africa, AngolaDeposit - Catoca
DS1982-0642
1982
Son, K.H.Won, I.J., Son, K.H.Crustal Interpretation of the Magsat Dat a in the Continental United States.National Technical Information Service NASA CR/169837 E83-10183, 35P.United StatesMid-continent, Magsat, Magnetics
DS1997-1085
1997
Sondag, F.Sondag, F., Soubies, F., Melfi, A.Hydrogeochemistry in soils and sediments in the area of the Lagoa Campestre Lake ( Salitre): chemical balancesApplied Geochemistry, Vol. 12, No. 2, March, 1, pp. 155-162Brazil, Minas GeraisRare earth elements, Laterites
DS200612-0202
2006
Sonder, I.Buttner, R., Dellino, P., Raue, H., Sonder, I., Zimanowski, B.Stress induced brittle fragmentation of magmatic melts: theory and experiments.Journal of Geophysical Research, Vol. 111, No. B8, B08204MantleMagmatism
DS201504-0226
2015
Sonder, I.Valentine, G.A., Graettinger, A.H, Macorps, E., Ross, P-S., White, J.D.L., Dohring, E., Sonder, I.Experiments with vertically and laterally migrating subsurface explosions with applications to the geology of phreatomagmatic and hydrothermal explosion craters and diatremes.Bulletin of Volcanology, Vol. 77, 15p.TechnologyDiatremes, kimberlites
DS201504-0227
2014
Sonder, I.Valentine, G.A., Graettinger, A.H, Sonder, I.Explosion depths for phreatomagmatic eruptions.Geophysical Research Letters, Vol. 41, pp. 3045-51.TechnologyMagmatism - phreatomagmatic
DS1992-1454
1992
Sonder, L.J.Sonder, L.J., Chamberlain, C.P.Tectonic controls of metamorphic field gradientsEarth and Planetary Science Letters, Vol. 111, No. 2-4, July pp. 517-536GlobalTectonics, Metamorphic gradients
DS1998-0704
1998
Sonder, L.J.Jones, C.H., Sonder, L.J., Unruh, J.R.Lithospheric gravitational potential energy and past orogenesis:implications for conditions - deformation..Geology, Vol. 26, No. 7, July pp. 639-642.Colorado, WyomingLaramide Orogeny, deformation, Mantle
DS1988-0301
1988
Sondergard, M.A.Herzfeld, U.C., Sondergard, M.A.MAPCOMP- a Fortran program for weighted Thematic Map comparisonComputers and Geosciences, Vol. 14, No. 5, pp. 699-714. Database # 17573GlobalComputer, Program- MAPCOMP
DS1991-1322
1991
Sonderholm, M.Peel, J.S., Sonderholm, M.Sedimentary basins: evolution, facies and sediment budgetGronslands Geologiske Undersogelse, 160pGreenlandSedimentary basins, Table of contents
DS1998-0302
1998
Sonderholm, M.Dam, G., Larsen, M., Sonderholm, M.Sedimentary response to mantle plumes: implications from Paleocene onshoresuccessions, West and East.Geology, Vol. 26, No. 3, March pp. 207-210.GreenlandPlume model, volcanism.
DS2002-0464
2002
SongFoden, J., Song, Turner, Elburg, Smith, VandersteldtGeochemical evolution of lithospheric mantle beneath southeast South AustraliaChemical Geology, Vol.182, 2-4, Feb.15, pp.663-95.Southeast AustraliaGeochemistry
DS201012-0867
2010
SongXu, C., Kynicky, J., Chamouradian, A.R., Qi, L., Wenlei, SongA unique Mo deposit associated with carbonatites in the Qinling orogenic belt, central China.Lithos, In press unformatted 46p. availableChinaCarbonatite
DS201705-0878
2017
SongSong, WL, Xu, C., Chakhmouradian, A.R., Kynicky, J., Huang, K., Zhang, ZL.Carbonatites of Tarim ( NW China): first evidence of crustal contribution in carbonatites from a large igneous province.Lithos, Vol. 282-283, pp. 1-9.ChinaCarbonatite, subduction

Abstract: Many carbonatites are associated both spatially and temporally with large igneous provinces (LIPs), and considered to originate from a mantle plume source lacking any contribution from recycled crustal materials. Here, we report an occurrence of carbonatite enriched in rare-earth elements (REE) and associated with the Tarim LIP in northwestern China. The Tarim LIP comprises intrusive and volcanic products of mantle plume activity spanning from ~ 300 to 280 Ma. The carbonatites at Wajilitage in the northwestern part of Tarim are dominated by calcite and dolomite varieties, and contain abundant REE minerals (principally, monazite and REE-fluorcarbonates). Th-Pb age determination of monazite yielded an emplacement age of 266 ± 5.3 Ma, i.e. appreciably younger than the eruption age of flood basalts at ~ 290 Ma. The carbonatites show low initial 87Sr/86Sr (0.7037-0.7041) and high ?Nd(t) (1.2-4) values, which depart from the isotopic characteristics of plume-derived basalts and high-Mg picrites from the same area. This indicates that the Wajilitage carbonatites derived from a mantle source isotopically distinct from the one responsible for the voluminous (ultra)mafic volcanism at Tarim. The carbonatites show ?26MgDSM3 values (? 0.99 to ? 0.65‰) that are significantly lower than those in typical mantle-derived rocks and rift carbonatites, but close to marine sediments and orogenic carbonatites. We propose that the carbonatites in the Tarim LIP formed by decompressional melting of recycled sediments mixed with the ambient mantle peridotite. The enriched components in the Tarim plume could be accounted for by the presence of recycled sedimentary components in the subcontinental mantle.
DS200412-1156
2004
Song, B.Liu, F., Xu, Z., Liou, J.G., Song, B.SHRIMP U Pb ages of ultrahigh pressure and retrograde metamorphism of gneisses, south western Sulu terrane, eastern China.Journal of Metamorphic Geology, Vol. 22, 4, pp. 315-326.ChinaGeochronology, UHP
DS200612-1336
2006
Song, B.Song, S., Zhang, L., Niu, Y., Li, S., Song, B., Liu, D.Evolution from oceanic subduction to continental collision: a case study from the northern Tibetan Plateau based on geochemical and geochronological data.Journal of Petrology, Vol. 47, 3, pp. 435-455.ChinaSubduction
DS201112-0591
2011
Song, D.Li, H., Li, S., Song, D., Gong, M., Li, X., Jia, J.Crustal and uppermost mantle velocity structure beneath northwestern Chin a from seismic ambient noise tomography.Geophysical Journal International, in press availableChinaGeophysics - seismics
DS201805-0981
2018
Song, J.Sun, N., Wei, W., Han, S., Song, J., Li, X., Duan, Y., Prakapenka, V.B., Mao, Z.Phase transition and thermal equations of state of (Fe, Al) -bridgmanite and post perovskite: implication for the chemical heterogeneity at the lowermost mantle.Earth Planetary Science Letters, Vol. 490, pp. 161-169.Mantleperovskite
DS201901-0083
2018
Song, J.Sun, N., Wei, W., Han, S., Song, J., Li, X, Duan, Y., Prakapenka, V.B., Mao, Z.Phase transition and thermal equations of state of ( Fe, Al) - bridgmanite and post-perovskite: implication for the chemical heterogeneity at the lowermost mantle.Earth and Planetary Science Letters, Vol. 490, 1, pp. 161-169.Mantlegeothermometry

Abstract: In this study, we have determined the phase boundary between Mg0.735Fe0.21Al0.07Si0.965O3-Bm and PPv and the thermal equations of state of both phases up to 202 GPa and 2600 K using synchrotron X-ray diffraction in laser heated diamond anvil cells. Our experimental results have shown that the combined effect of Fe and Al produces a wide two-phase coexistence region with a thickness of 26 GPa (410 km) at 2200 K, and addition of Fe lowers the onset transition pressure to 98 GPa at 2000 K, consistent with previous experimental results. Furthermore, addition of Fe was noted to reduce the density (?) and bulk sound velocity () contrasts across the Bm-PPv phase transition, which is in contrast to the effect of Al. Using the obtained phase diagram and thermal equations of state of Bm and PPv, we have also examined the effect of composition variations on the ? and profiles of the lowermost mantle. Our modeling results have shown that the pyrolitic lowermost mantle should be highly heterogeneous in composition and temperature laterally to match the observed variations in the depth and seismic signatures of the D? discontinuity. Normal mantle in a pyrolitic composition with ?10% Fe and Al in Bm and PPv will lack clear seismic signature of the D? discontinuity because the broad phase boundary could smooth the velocity contrast between Bm and PPv. On the other hand, Fe-enriched regions close to the cold slabs may show a seismic signature with a change in the velocity slope of the D? discontinuity, consistent with recent seismic observations beneath the eastern Alaska. Only regions depleted in Fe and Al near the cold slabs would show a sharp change in velocity. Fe in such regions could be removed to the outer core by strong core-mantle interactions or partitions together with Al to the high-pressure phases in the subduction mid ocean ridge basalts. Our results thus have profound implication for the composition of the lowermost mantle.
DS202106-0952
2021
Song, J.Li, W., Xie, X., Song, J., Xie, R., Wang, J., Li, G.,Hou, H., Lu, J.Assessment and source identification of toxic metals in an abandoned synthetic diamond production plant from Anhui Province, China.Environmental Forensics, Vol. 22, 3-4, pp. 340-350. abstract onlyChinasynthetics

Abstract: In this study, soil and sediment samples along with groundwater samples were collected and analyzed from an abandoned synthetic diamond production plant in Anhui Province, South China. Chemical analysis, pollution characteristics analysis, and correlation analysis were conducted to assess and to determine the source(s) of the toxic metal and organic pollutions in the study sites. The Co and Ni concentrations of soil samples collected from the production area exceed the risk screening value for contaminated development land in Soil Environment Quality Standards for soil pollution risk control on construction land (Trial) of China, while the concentrations of other toxic elements such as Cr, Cu, and Zn are lower than the screening value. The PCA and HCA results are consistent with the correlation coefficient analysis and indicate that industrial activities are the main sources of Co and Ni. The chemical composition and source analysis results of soil and groundwater show that toxic metals originating from catalyst and low pH value from acid waste water should be the main point of concern in the synthetic diamond production plant.
DS201412-0520
2014
Song, M.Liu, X., Xiong, X., Audetat, A., Li, Y., Song, M., Li, L., Sun, W., Ding, X.Partitioning of copper between olivine, orthopyroxene, clinopyroxene, spinel, garnet, and silicate melts at upper mantle conditions.Geochimica et Cosmochimica Acta, Vol. 125, pp. 1-22.MantleMineral chemistry
DS201802-0268
2018
Song, M-s.Sun, W-d., Hawkesworth, C.J., Yao, C., Zhang, C-C., Huang, R.f., Liu, X., Sun, X-L, Ireland, T., Song, M-s., Ling, M-x., Ding, X., Zhang, Z-f., Fan, W-m., Wu, Z-q.Carbonated mantle domains at the base of the Earth's transition zone.Chemical Geology, Vol. 478, pp. 69-75.Mantlecarbonatite

Abstract: The oxygen fugacity of the upper mantle is 3-4 orders of magnitude higher than that of the lower mantle and this has been attributed to Fe2 + disproportionating into Fe3 + plus Fe0 at pressures > 24 GPa. The upper mantle might therefore have been expected to have evolved to more oxidizing compositions through geological time, but it appears that the oxygen fugacity of the upper mantle has remained constant for the last 3.5 billion years. Thus, it indicates that the mantle has been actively buffered from the accumulation of Fe3 +, and that this is linked to oxidation of diamond to carbonate coupled with reduction of Fe3 + to Fe2 +. When subducted plates penetrate into the lower mantle, compensational upwelling transports bridgmanite into the transition zone, where it breaks down to ringwoodite and majorite, releasing the ferric iron. The system returns to equilibrium through oxidation of diamond. Early in Earth history, diamond may have been enriched at the base of the transition zone in the Magma Ocean, because it is denser than peridotite melts at depths shallower than 660 km, and it is more buoyant below. Ongoing oxidation of diamond forms carbonate, leading to relatively high carbonate concentrations in the source of ocean island basalts.
DS2003-1313
2003
Song, S.Song, S., Yang, J., Liou, J.G., Wu, C., Shi, R., Xu, Z.Petrology, geochemistry and isotopic ages of eclogites from the Dulan UHPM terraneLithos, Vol. 70, 3-4, pp. 195-211.ChinaUHP, geochronology
DS200412-1878
2003
Song, S.Song, S., Yang, J., Liou, J.G., Wu, C., Shi, R., Xu, Z.Petrology, geochemistry and isotopic ages of eclogites from the Dulan UHPM terrane, the North Qaidam NW China.Lithos, Vol. 70, 3-4, pp. 195-211.ChinaUHP, geochronology
DS200412-1879
2004
Song, S.Song, S., Zhang, L., Niu, Y.Ultra deep origin of garnet peridotite from north Qaidam ultrahigh pressure belt, northern Tibetan Plateau, NW China.American Mineralogist, Vol. 89, 7, pp. 1330-36.China, TibetUHP
DS200512-1026
2005
Song, S.Song, S., Zhang, L., Chen, J., Liou, J.G., Niu, Y.Sodic amphibole exsolutions in garnet from garnet-peridotite, North Qaidam UHP belt, NW China: implications for ultradeep origin and hydroxyl defects in mantle garnets.American Mineralogist, Vol. 90, pp. 814-820.ChinaUHP, water
DS200512-1027
2005
Song, S.Song, S., Zhang, L., Niu, Y., Su, L., Jian, P., Liu, D.Geochronology of diamond bearing zircons from garnet peridotite in the North Qaidam UHPM belt, Northern Tibetan Plateau: a record of lithospheric subduction.Earth and Planetary Science Letters, Vol. 234, 1-2, pp. 99-118.Asia, TibetGeochronology
DS200512-1244
2005
Song, S.Zhang, L., Song, S., Liou, J.G., Ai, Y., Li, X.Relict coesite exsolution omphacite from western Tian Shan eclogites, China.American Mineralogist, Vol. 90, 1, Jan. pp. 181-186.ChinaUHP
DS200612-1336
2006
Song, S.Song, S., Zhang, L., Niu, Y., Li, S., Song, B., Liu, D.Evolution from oceanic subduction to continental collision: a case study from the northern Tibetan Plateau based on geochemical and geochronological data.Journal of Petrology, Vol. 47, 3, pp. 435-455.ChinaSubduction
DS200912-0716
2009
Song, S.Song, S., Su, L., Niu, Y., Lai, Y., Zhang, L.CH4 inclusions in orogenic harzburgite: evidence for reduced slab fluids and implication for redox melting in mantle wedge.Geochimica et Cosmochimica Acta, Vol. 73, 6, pp. 1737-1754.MantleSubduction
DS200912-0717
2009
Song, S.Song, S., Su, L., Niu, Y., Zhang, G., Zhang, L.Two types of peridotite in North Qaidam UHPM belt and their tectonic implications for oceanic and continental subduction: a review.Journal of Asian Earth Sciences, Vol. 35, 3-4, pp. 285-297.ChinaUHP
DS201012-0868
2010
Song, S.Xu, Y., Song, S., Zheng, Y-F.Evidence from pyroxenite xenoliths for subducted lower oceanic crust in subcontinental lithospheric mante,Goldschmidt 2010 abstracts, abstractMantleSubduction
DS201112-1160
2011
Song, S.Zhang, C., Zhang, L., Van Roermund, H., Song, S., Zhang, G.Petrology and SHRIMP U-Pb dating of Xitieshan eclogite, North Quidam, UHP metamorphic belt, NW China.Journal of Asian Earth Sciences, Vol. 32, 4, pp. 752-767.ChinaUHP
DS201412-0871
2014
Song, S.Song, S., Niu, Y., Zhang, C., Zhang, L.Continental orogenesis from ocean subduction, continent collision/subduction, to orogen collapse, and orogen recycling: the example of the North Qaidam UHPM belt, NW China.Earth Science Reviews, Vol. 129, pp. 59-84.ChinaUHP
DS201908-1821
2019
Song, S.Wang, C., Song, S., Wei, C., Su, L., Allen, M.B., Niu, Y., Li, X-H., Dong, J.Paleoarchean deep mantle heterogeneity recorded by enriched plume remnants.Nature Geoscience, doi.org/10.1038/s41561-019-0410-y 10p pdfMantlePlumes, hotspots

Abstract: The thermal and chemical state of the early Archaean deep mantle is poorly resolved due to the rare occurrences of early Archaean magnesium-rich volcanic rocks. In particular, it is not clear whether compositional heterogeneity existed in the early Archaean deep mantle and, if it did, how deep mantle heterogeneity formed. Here we present a geochronological and geochemical study on a Palaeoarchaean ultramafic-mafic suite (3.45-Gyr-old) with mantle plume signatures in Longwan, Eastern Hebei, the North China Craton. This suite consists of metamorphosed cumulates and basalts. The meta-basalts are iron rich and show the geochemical characteristics of present-day oceanic island basalt and unusually high mantle potential temperatures (1,675?°C), which suggests a deep mantle source enriched in iron and incompatible elements. The Longwan ultramafic-mafic suite is best interpreted as the remnants of a 3.45-Gyr-old enriched mantle plume. The first emergence of mantle-plume-related rocks on the Earth 3.5-3.45?billion years ago indicates that a global mantle plume event occurred with the onset of large-scale deep mantle convection in the Palaeoarchaean. Various deep mantle sources of these Palaeoarchaean mantle-plume-related rocks imply that significant compositional heterogeneity was present in the Palaeoarchaean deep mantle, most probably introduced by recycled crustal material.
DS2003-1314
2003
Song, S.G.Song, S.G., Yang, J.S., Xu, ZQ, Shi, R.D.Metamorphic evolution of the coesite bearing ultrahigh pressure terrane in the NorthJournal of Metamorphic Geology, Vol. 21, 6, pp. 631-44.ChinaUHP
DS200412-1880
2003
Song, S.G.Song, S.G., Yang, J.S., Xu, ZQ, Shi, R.D.Metamorphic evolution of the coesite bearing ultrahigh pressure terrane in the North Qaidam northern Tibet, NW China.Journal of Metamorphic Geology, Vol. 21, 6, pp. 631-44.ChinaUHP
DS200712-1016
2007
Song, S.G.Song, S.G., Zhang, L.F., Niu, Y., Wei, C.J., Liou, J.G., Shu, G.M.Ecologite and carpholite bearing metasedimentary rocks in the North Qilian suture zone, NW China: implications for Early Paleozoic cold oceanic subduction and water transport intoJournal of Metamorphic Geology, Vol. 25, 5, pp. 547-563.MantleWater transport
DS201112-0141
2011
Song, S.G.Cao, Y., Song, S.G., Niu, Y.L., Jung, H., Jin, Z.M.Variation of mineral composition, fabric and oxygen fugacity from massive to foliated eclogites during exhumation of subducted ocean crust in North Qiilian sutureJournal of Metamorphic Geology, Vol. 29, 7, pp. 699-720.ChinaSubduction
DS1993-1511
1993
Song, S.H.Song, S.H., Foden, J.Geochemical evolution of lithospheric mantle beneath Southeast South Australia.The Xenolith window into the lower crust, abstract volume and workshop, p. 18AustraliaGeochemistry, Mantle
DS200712-1017
2007
Song, T-R.A.Song, T-R.A., Helberger, D.V.A depleted destabilized continental lithosphere near the Rio Grande Rift.Earth and Planetary Science Letters, Vol. 262, 1-2, pp. 175-184.United States, Colorado PlateauTectonics
DS201112-0186
2011
Song, W.Chilarova, H., Kynicky , Cheng, X., Song, W., Chalmouradian, A., Reguir, K.The largest deposit of strategic REE Bayan Obo, geological situation and environmental hazards.Goldschmidt Conference 2011, abstract p.677.ChinaCarbonatite, bastnaesite
DS201112-1128
2011
Song, W.Xu, C., Taylor, R.N., Kynicky, J., Chakhmouradiam, A.R., Song, W., Wang, L.The origin of enriched mantle beneath North Chin a block: evidence from young carbonatites.Lithos, Vol. 127, 1-2, pp. 1-9.ChinaCarbonatite
DS201412-0995
2014
Song, W.Xu, C., Chakhmouradian, A.R., Taylor, R.N., Kynicky, J., Li, W., Song, W., Fletcher, I.R.Origin of carbonatites in the South Qinling orogen: implications for crustal recycling and timing of collision between south and north Chin a blocks.Geochimica et Cosmochimica Acta, Vol. 143, pp. 189-206.ChinaCarbonatite
DS201705-0890
2017
Song, W.Xu, C., Kynicky, J., Tao, R., Liu, X., Zhang, L., Pohanka, M., Song, W., Fei, Y.Recovery of an oxidized majorite inclusion from Earth's deep asthenosphere.Science Advances, Vol. 3, 4, e1601589MantleEclogite

Abstract: Minerals recovered from the deep mantle provide a rare glimpse into deep Earth processes. We report the first discovery of ferric iron-rich majoritic garnet found as inclusions in a host garnet within an eclogite xenolith originating in the deep mantle. The composition of the host garnet indicates an ultrahigh-pressure metamorphic origin, probably at a depth of ~200 km. More importantly, the ferric iron-rich majoritic garnet inclusions show a much deeper origin, at least at a depth of 380 km. The majoritic nature of the inclusions is confirmed by mineral chemistry, x-ray diffraction, and Raman spectroscopy, and their depth of origin is constrained by a new experimental calibration. The unique relationship between the majoritic inclusions and their host garnet has important implications for mantle dynamics within the deep asthenosphere. The high ferric iron content of the inclusions provides insights into the oxidation state of the deep upper mantle.
DS201707-1370
2017
Song, W.Song, W., Xu, C., Chakhmouradian, A.R., Kynicky, J., Huang, K., Zhang, Z.Carbonatites of Tarim ( NW China): first evidence of crustal contribution in carbonatites from large igneous province.Lithos, Vol. 282-283, pp. 1-9.China, Mongoliacarbonatite - Tarim

Abstract: Many carbonatites are associated both spatially and temporally with large igneous provinces (LIPs), and considered to originate from a mantle plume source lacking any contribution from recycled crustal materials. Here, we report an occurrence of carbonatite enriched in rare-earth elements (REE) and associated with the Tarim LIP in northwestern China. The Tarim LIP comprises intrusive and volcanic products of mantle plume activity spanning from ~ 300 to 280 Ma. The carbonatites at Wajilitage in the northwestern part of Tarim are dominated by calcite and dolomite varieties, and contain abundant REE minerals (principally, monazite and REE-fluorcarbonates). Th–Pb age determination of monazite yielded an emplacement age of 266 ± 5.3 Ma, i.e. appreciably younger than the eruption age of flood basalts at ~ 290 Ma. The carbonatites show low initial 87Sr/86Sr (0.7037–0.7041) and high ?Nd(t) (1.2–4) values, which depart from the isotopic characteristics of plume-derived basalts and high-Mg picrites from the same area. This indicates that the Wajilitage carbonatites derived from a mantle source isotopically distinct from the one responsible for the voluminous (ultra)mafic volcanism at Tarim. The carbonatites show ?26MgDSM3 values (? 0.99 to ? 0.65‰) that are significantly lower than those in typical mantle-derived rocks and rift carbonatites, but close to marine sediments and orogenic carbonatites. We propose that the carbonatites in the Tarim LIP formed by decompressional melting of recycled sediments mixed with the ambient mantle peridotite. The enriched components in the Tarim plume could be accounted for by the presence of recycled sedimentary components in the subcontinental mantle.
DS201712-2683
2017
Song, W.Deng, M., Xu, C., Song, W., Tang, H., Liu, Y., Zang, Q., Zhou, Y., Feng, M., Wei, C.REE mineralization in the Bayan Obo deposit, China: evidence from mineral paragenesis.Ore Geology Reviews, in press available, 10p.Chinadeposit - Bayan Obo

Abstract: Preliminary mineralogical and geochemical studies have been carried out on dolomite marble drill cores from the Bayan Obo REE deposit in China. Three types of apatites and four types of monazites have been identified based on textural features: Type 1 apatite occurs as grains with minor monazite (Type 1 monazite) on its border; Type 2 apatite veinlet shows clusters of assemblages with abundant bastnäsite and parisite at the rim; Type 3 apatite has a linear array associated with fluorite and bastnäsite veinlets. Type 2 monazite occurs as clusters intergrowing with parisite and fluorite. Type 3 and 4 monazites occur as polymineralic (fluorite and bastnäsite) and monomineralic veinlets, respectively. These four types of monazites have similar LREE composition but variable Y content (Y2O3 ranging from below determination limits to 0.7?wt%). The three types of apatites also show different REE content and distribution patterns, ranging from high REE abundance (?REE?+?Y: 27243-251789?ppm) and strong LREE enrichment [(La/Yb)CN ?101] in Type 1, less LREE enrichment [(La/Yb)CN ?8] in Type 2 to relatively low REE abundance (?REE?+?Y: 4323-11175?ppm) but high REE fractionation [(La/Yb)CN ?58] in Type 3. The primary apatite has high Sr (5461-6892?ppm) and REE content, implying a carbonatite origin. The late-stage apatites (Types 2 and 3) show different Sr and REE abundances. Significant differences in their Sr composition (6189?±?573, 6041?±?549 and 3492?±?802 for Types 1-3 samples, respectively) and Y/Ho ratio (20.9?±?0.11, 19.5?±?0.17 and 17.4?±?0.37, respectively) indicate that the three types of apatites may have crystallized from different metasomatic fluids. Multi-stage metasomatism resulted in remobilization and redeposition of primary REE minerals to form the Bayan Obo REE deposit.
DS201805-0977
2018
Song, W.Smith, M., Kynicky, J., Xu, C., Song, W., Spratt, J., Jeffries, T., Brtnicky, M., Kopriva, A., Cangelosi, D.The origin of secondary heavy rare earth element enrichment in carbonatites: constraints from the evolution of the Huanglongpu district, China.Lithos, Vol. 308-309, pp. 65-82.Chinacarbonatite

Abstract: The silico?carbonatite dykes of the Huanglongpu area, Lesser Qinling, China, are unusual in that they are quartz-bearing, Mo-mineralised and enriched in the heavy rare earth elements (HREE) relative to typical carbonatites. The textures of REE minerals indicate crystallisation of monazite-(Ce), bastnäsite-(Ce), parisite-(Ce) and aeschynite-(Ce) as magmatic phases. Burbankite was also potentially an early crystallising phase. Monazite-(Ce) was subsequently altered to produce a second generation of apatite, which was in turn replaced and overgrown by britholite-(Ce), accompanied by the formation of allanite-(Ce). Bastnäsite and parisite where replaced by synchysite-(Ce) and röntgenite-(Ce). Aeschynite-(Ce) was altered to uranopyrochlore and then pyrochlore with uraninite inclusions. The mineralogical evolution reflects the evolution from magmatic carbonatite, to more silica-rich conditions during early hydrothermal processes, to fully hydrothermal conditions accompanied by the formation of sulphate minerals. Each alteration stage resulted in the preferential leaching of the LREE and enrichment in the HREE. Mass balance considerations indicate hydrothermal fluids must have contributed HREE to the mineralisation. The evolution of the fluorcarbonate mineral assemblage requires an increase in aCa2+ and aCO32? in the metasomatic fluid (where a is activity), and breakdown of HREE-enriched calcite may have been the HREE source. Leaching in the presence of strong, LREE-selective ligands (Cl?) may account for the depletion in late stage minerals in the LREE, but cannot account for subsequent preferential HREE addition. Fluid inclusion data indicate the presence of sulphate-rich brines during alteration, and hence sulphate complexation may have been important for preferential HREE transport. Alongside HREE-enriched magmatic sources, and enrichment during magmatic processes, late stage alteration with non-LREE-selective ligands may be critical in forming HREE-enriched carbonatites.
DS201805-0979
2018
Song, W.Song, W., Xi, C., Smith, M.P., Chakhmouradian, A.R., Brenna, M., Kynicky, J., Chen, W., Yang, Y., Tang, H.Genesis of the world's largest rare earth element deposit, Bayan Obo, China: protracted mineralization evolution over ~ 1.b.y.Geology, Vol. 48, 4, pp. 323-326.Chinadeposit - Bayan Obo

Abstract: The unique, giant, rare earth element (REE) deposit at Bayan Obo, northern China, is the world’s largest REE deposit. It is geologically complex, and its genesis is still debated. Here, we report in situ Th-Pb dating and Nd isotope ratios for monazite and Sr isotope ratios for dolomite and apatite from fresh drill cores. The measured monazite ages (361-913 Ma) and previously reported whole-rock Sm-Nd data show a linear relationship with the initial Nd isotope ratio, suggesting a single-stage evolution from a Sm-Nd source that was formed before 913 Ma. All monazites show consistent ?Nd(1.3Ga) values (0.3 ± 0.6) close to those of the adjacent 1.3 Ga carbonatite and mafic dikes. The primary dolomite and apatite show lower 87Sr/86Sr ratios (0.7024-0.7030) than the recrystallized dolomite (0.7038-0.7097). The REE ores at Bayan Obo are interpreted to have originally formed as products of ca. 1.3 Ga carbonatitic magmatism and to have undergone subsequent thermal perturbations induced by Sr-rich, but REE-poor, metamorphic fluids derived from nearby sedimentary rocks.
DS201810-2348
2018
Song, W.Liu, Y., Chakhmouradian, A.R., Hou, Z., Song, W., Kynicky, J.Development of REE mineralization in the giant Maoniuping deposit ( Sichuan, China): insights from mineralogy, fluid inclusions, and trace element geochemistry.Mineralium Deposita, doi.org/10.1007/s00126-018-0836-y 18p.Chinacarbonatite

Abstract: Rare-earth deposits associated with intrusive carbonatite complexes are the world’s most important source of these elements (REE). One of the largest deposits of this type is Maoniuping in the Mianning-Dechang metallogenic belt of eastern Tibet (Sichuan, China). In the currently mined central part of the deposit (Dagudao section), REE mineralization is hosted by a structurally and mineralogically complex Late Oligocene (26.4 ±?1.2 Ma, 40Ar/39Ar age of fluorphlogopite associated with bastnäsite) hydrothermal vein system developed in a coeval syenite intrusion. Low-grade stockworks of multiple veinlets and breccias in the lower part of the orebody grade upwards into progressively thicker veins (up to 12 m in width) that are typically zoned and comprise ferromagnesian micas (biotite to fluorphlogopite), sodium clinopyroxenes (aegirine to aegirine-augite), sodium amphiboles (magnesio-arfvedsonite to fluororichterite), K-feldspar, fluorite, barite, calcite, and bastnäsite. The latter four minerals are most common in the uppermost 80 m of the Dagudao section and represent the climax of hydrothermal activity. Systematic variations in the fluid inclusion data indicate a continuous hydrothermal evolution from about 230-400 °C (fluid inclusions in feldspar, clinopyroxene, and amphibole) to 140-240 °C (fluid inclusions in bastnäsite, fluorite, calcite). Hydrothermal REE transport was probably controlled by F?, (SO4)2?, Cl?, and (CO3)2? as complexing ligands. We propose that at Dagudao, silicate magmas produced orthomagmatic fluids that explored and expanded a fissure system generated by strike-slip faulting. Initially, the fluids had appreciable capacity to transport REE and, consequently, no major mineralization developed. The earliest minerals to precipitate were alkali- and Fe-rich silicates containing low levels of F, which caused progressive enrichment of the fluid in Ca, Mg, F, Cl, REE, (SO4)2?, and (CO3)2?, leading to the crystallization of aegirine-augite, fluororichterite, fluorphlogopite, fluorite, barite, calcite, and bastnäsite gradually. Barite, fluorite, calcite, and bastnäsite are the most common minerals in typical ores, and bastnäsite generally postdates these gangue minerals. Thus, it is very probable that fluid cooling and formation of large amount of fluorite, barite, and calcite triggered bastnäsite precipitation in the waning stage of hydrothermal activity.
DS201906-1308
2019
Song, W.Kynicky, J., Smith, M.P., Song, W., Fryzova, R., Brtnicky, M.The role of carbonate-flouride melt immiscibility in shallow REE deposits evolution: new evidence from Mongolia.3rd International Critical Metals Meeting held Edinburgh, 1p. abstract p. 52.Asia, MongoliaREE
DS202003-0337
2020
Song, W.Feng, M., Song, W., Kynicky, J., Smith, M., Cox, C., Kotlanova, M., Brtnicky, M., Fu, W., Wei, C.Primary rare earth element enrichment in carbonatites: evidence from melt inclusions in Ulgii Khild carbonatite, Mongolia.Ore Geology Reviews, Vol. 117, 14p. PdfAsia, Mongoliadeposit - Ulgii Khild
DS201906-1363
2019
Song, W.L.Wei, C.W., Xu, C., Chakhmouradian, A.R., Brenna, M., Kynicky, J., Song, W.L.Petrogenesi of dolomite and calcite carbonatites in orogenic belts.GAC/MAC annual Meeting, 1p. Abstract p. 194.Chinadeposit - Caotan

Abstract: Subduction zones are an important way for crustal materials to enter deep parts of the Earth. Therefore, carbonatites in orogenic belt are of great significance in revealing deep carbon cycling pathways. To date, mantle-derived carbonatites have been identified in many orogenic belts, and their origin is considered to be related to subducted sediments. However, almost all orogenic carbonatites are composed of calcite, and their C isotopic compositions show typical mantle values, lacking any evidence of sedimentary origin. Here, we report decoupling of C and Sr isotopes between intimately associated dolomite and forsterite-calcite carbonatites from Caotan in the Qinling orogen, central China. The dolomite carbonatite is mainly composed of dolomite (plus minor apatite and magnetite), which has elevated ?13CPDB values (-3.1 to -3.6 ‰) and low 87Sr/86Sr ratios (0.7026-0.7042). The forsterite-calcite carbonatite consists of calcite (60-65 vol. %), forsterite and its replacement products (30-35 vol. %), and magnetite. The calcite shows mantle-like ?13CPDB (-6.2 to -7.2 ‰) but high initial 87Sr/86Sr values (0.7053-0.7076). Neodymium and Pb isotopic compositions are comparable in the two carbonatite types. The forsterite-calcite carbonatite is interpreted to have formed by metasomatic interaction of primary dolomitic melts with eclogite in thickened lower crust during collision of the North and South China cratons. The reaction resulted in decarbonation and depletion of the carbonatitic magma in 13C. Because of its initially low REE and Pb contents, the Nd-Pb isotopic signature of the primary dolomitic melt was preserved in the forsterite-calcite carbonatite. We propose that some orogenic calcite carbonatites may not be primary mantle-derived rocks and their mantle-like ?13CPDB values may be misleading.
DS202106-0972
2021
Song, W.L.Sun, J., Zhu, X-K., Belshaw, N.S., Chen, W., Doroshkevich, A.G., Luo, W.J., Song, W.L., Chen, B.B., Cheng, Z.G., Li, Z.H., Wang, Y., Kynicky, J., Henderson, G.M.Ca isotope systematics of carbonatites: insights into carbonatite source and evolution.Geochemical Perspectives Letters, Vol. 17, pp. 11-15. pdfMantlecarbonatites

Abstract: Carbonatite, an unusual carbonate-rich igneous rock, is known to be sourced from the mantle which provides insights into mantle-to-crust carbon transfer. To constrain further the Ca isotopic composition of carbonatites, investigate the behaviour of Ca isotopes during their evolution, and constrain whether recycled carbonates are involved in their source regions, we report ?44/42Ca for 47 worldwide carbonatite and associated silicate rocks using a refined analytical protocol. Our results show that primary carbonatite and associated silicate rocks are rather homogeneous in Ca isotope compositions that are comparable to ?44/42Ca values of basalts, while non-primary carbonatites show detectable ?44/42Ca variations that are correlated to ?13C values. Our finding suggests that Ca isotopes fractionate during late stages of carbonatite evolution, making it a useful tool in the study of carbonatite evolution. The finding also implies that carbonatite is sourced from a mantle source without requiring the involvement of recycled carbonates.
DS201602-0242
2016
Song, WL.Song, WL., Xu, C., Veksler, H.V., Kynicky, J.Experimental study of REE, Ba, Sr, Mo and W partitioning between carbonatitic melt and aqueous fluid with implications for rare metal mineralization.Contributions to Mineralogy and Petrology, Vol. 171, 12p.MantleCarbonatite

Abstract: Carbonatites host some unique ore deposits, especially rare earth elements (REE). Hydrothermal fluids have been proposed to play a significant role in the concentration and transport of REE and other rare metals in carbonatites, but experimental constraints on fluid-melt equilibria in carbonatitic systems are sparse. Here we present an experimental study of trace element (REE, Ba, Sr, Mo and W) partitioning between hydrous fluids and carbonatitic melts, bearing on potential hydrothermal activity associated with carbonatite ore-forming systems. The experiments were performed on mixtures of synthetic carbonate melts and aqueous fluids at 700-800 °C and 100-200 MPa using rapid-quench cold-seal pressure vessels and double-capsule assemblages with diamond traps for analyzing fluid precipitates in the outer capsule. Starting mixtures were composed of Ca, Mg and Na carbonates spiked with trace elements. Small amounts of F or Cl were added to some of the mixtures to study the effects of halogens on the element distribution. The results show that REE, Ba, Sr, Mo and W all preferentially partition into carbonatite melt and have fluid-melt distribution coefficients (D f/m) below unity. The REE partitioning is slightly dependent on the major element (Ca, Mg and Na) composition of the starting mixtures, and it is influenced by temperature, pressure, and the presence of halogens. The fluid-melt D values of individual REE vary from 0.02 to 0.15 with Df/mLu being larger than Df/mLa by a factor of 1.1-2. The halogens F and Cl have strong and opposite effects on the REE partitioning. Fluid-melt D REE are about three times higher in F-bearing compositions and ten times lower in Cl-bearing compositions than in halogen-free systems. Df/mW and Df/mMo are the highest among the studied elements and vary between 0.6 and 0.7; Df/mBa is between 0.05 and 0.09, whereas Df/mSr is at about 0.01-0.02. The results imply that carbonatite-related REE deposits were probably formed by fractional crystallization of carbonatitic melts rather than from exsolved hydrothermal fluids. The same appears to be true for a carbonatite-related Mo deposit recently discovered in China.
DS2002-1570
2002
Song, X.Sun, X., Song, X.PKP travel times at near antipodal distances: implications for inner core anisotropy and lowermost mantle structure.Earth and Planetary Science Letters, Vol.199,3-4,pp.429-45.MantleGeophysics - anisotropy
DS200812-1143
2008
Song, X.Sun, X., Song, X.The inner core of the Earth: texturing of iron crystals from three dimensional seismic anisotropy.Earth and Planetary Science Letters, Vol. 269, 1-2, May 15, pp. 56-65.MantleGeophysics - seismics
DS201503-0178
2015
Song, X.Wang, T., Song, X., Xia, H.H.Earth's core has a core.Nature Geoscience, Feb. 10, 3p. OnlineEarth, MantleGeophysics - seismic
DS202202-0226
2021
Song, X.Yin, J.N., Song, X.A review of major rare earth element and yttrium deposits in China.Australian Journal of Earth Sciences, Vol.1, pp. 1-25. pdfChinaREE

Abstract: Rare earth element and yttrium (REY) deposits are important strategic resources widely used in high-tech applications, such as solar cells and wind turbines. This paper summarises the temporal-spatial characteristics and genesis of REY deposits in China classified as alkaline carbonatite, ion-adsorption, placer, sedimentary metamorphism, marine sedimentary phosphorite and coal-hosted REY types. This study focuses on alkaline carbonatite and ion-adsorption deposits, because of their importance in terms of both exploitation and global reserves. The general characteristics, genesis, and enrichment of these REY deposit types are summarised, and eight districts have been identified as having prospectivity for REY, based on geological and geochemical data. An overview of these districts is presented, together with a detailed investigation of four important districts in terms of geological settings, mineralisation, regional deposit models and metallogenic prospect. KEY POINTS: 1) REY deposits in China can be classified as alkaline carbonatite, ion-adsorption, placer, sedimentary metamorphism and marine sedimentary phosphorite and coal-hosted REY types. 2) Ion-adsorption REY in the weathering profile of granitic rocks is strongly controlled by the resistance to weathering, climate, topography and layers of weathering crust. 3) Carbonatite and alkaline rocks are major hosts for REYs and commonly have high concentrations of REY-bearing accessory minerals. 4) Eight districts have been identified as having prospectivity for REY in China.
DS200612-0093
2006
Song, X.H.Barron, L.M., Song, X.H.Radial strain birefringence in UHP diamond from Copeton, NSW.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.Australia, New South WalesDiamond morphology
DS1989-0256
1989
Song, Y.Chen, C.Y., Frey, F.A., Song, Y.Evolution of the upper mantle beneath southeastAustralia: geochemical evidence from peridotite xenoliths in Mount Leura basaniteEarth and Planetary Science Letters, Vol. 93, No. 2, June pp. 195-209AustraliaBasanite, Mount Leura
DS1989-1432
1989
Song, Y.Song, Y., Zhi, X., Frey, F.A.The geochemistry of basalts and mantle xenoliths From the Hannouba eastern China: implications for petrogenesis and the composition of subcont.mantleNew Mexico Bureau of Mines Bulletin., Continental Magmatism Abstract Volume, Held, Bulletin. No. 131, p. 250. AbstractChinaXenoliths
DS200712-1203
2007
Song, Y.Ye, K., Song, Y., Wu, J.Upward mantle wedge convection recorded by Zhimafang orogenic garnet lherzolite, Sulu UHP terrane, eastern China.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p. 258-259.ChinaUHP
DS200712-1204
2007
Song, Y.Ye, K., Song, Y., Wu, J.Upward mantle wedge convection recorded by Zhimafang orogenic garnet lherzolite, Sulu UHP terrane, eastern China.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p. 258-259.ChinaUHP
DS201505-0235
2015
Song, Y.Giuliani, G.,Pivin, M., Fallick, A.E., Ohnenstetter, D., Song, Y., Demaiffe, D.Geochemical and oxygen isotope signatures of mantle corundum megacrysts from the Mbuji-Mayi kimberlite, Democratic Republic of Congo and the Changle alkali basalt, China.Comptes Rendus Geoscience, Vol. 347, 1, pp. 24-34.Africa, Democratic Republic of Congo, ChinaDeposit - Mbuji-Mayi
DS202103-0426
2021
Song, Y.Zhou, L., Chai, C., Zhang, W., Song, Y., Zhang, Z., Yang, Y.oI20-carbon: a new superhard carbon allotrope.Diamond & Related Materials, Vol. 113, 108284, 8p. PdfGlobalcarbon

Abstract: A new orthorhombic carbon crystal denoted oI20?carbon possessing the Immm space group was designed. Its structure is formed by stacking of a cage structure, which consists of 32 carbon atoms. Its stability and structural, mechanical and electronic properties were investigated by first-principles simulations. Density functional theory calculations show that this new carbon allotrope is thermodynamically stable (even more stable than synthesized T?carbon and supercubane). Ab initio molecular dynamics (AIMD) simulations show that it can maintain the structure above a temperature of 1000 K, indicating its excellent thermal stability. oI20?carbon can also maintain dynamic stability under a high pressure of 100 GPa. It is an anisotropic superhard material with a Vickers hardness of 46.62 GPa. Notably, the cage structure gives it a low density, which has a really small value among superhard carbon allotropes. In addition, it is worth noting that oI20?carbon has an indirect ultrawide band structure with a bandgap of 4.55 eV (HSE06), which is higher than that of most previously reported superhard carbon allotropes. All these outstanding properties show that it is a potential material for high-temperature, high-frequency electronic devices and the aerospace industry.
DS202105-0762
2021
Song, Y.Dong, B., Shi, C., Xu, Z., Wang, K., Luo, H., Sun, F., Wang, P., Wu, E., Zhang, K., Liu, J., Song, Y., Fan, Y.Temperature dependence of optical centers in 1b diamond characteristics by photoluminescence spectra. CVDDiamond & Related Materials, Vol. 116, 108389, 10p. PdfGlobalsynthetics
DS201608-1441
2016
Song, Z.Song, Z., Lu, T., Tang, S., Ke, J., Su, J., Gao, B., Bi, L., Wang, D.Identification of colourless HPHT grown synthetic diamonds from Shandong China.The Journal of Gemmology, Vol. 35, 2, pp. 14-147.ChinaSynthetics
DS201804-0747
2017
Song, Z.Tang, S., Song, Z., Lu, T., Su, J., Ma, Y.Two natural type IIa diamonds with strong phosphorescence and Ni related defects.Gems & Gemology Lab Notes, Vol. 53, 4, pp. 476-478.Technologyfluoresecence

Abstract: Strong phosphorescence under UV excitation is rarely seen in natural diamond and normally limited to hydrogen-rich type Ia or type IaA/Ib chameleons and type IIb diamonds (T. Hainschwang et al., "A gemological study of a collection of chameleon diamonds," Spring 2005 G&G, pp. 20-35; S. Eaton-Magaña and R. Lu, "Phosphorescence in type IIb diamonds," Diamond and Related Materials, Vol. 20, No. 7, 2011, pp. 983-989). When seen in other diamond types, an even rarer occurrence, it is shorter and less intense. Recently, the National Gemstone Testing Center (NGTC) in Beijing encountered two natural diamonds that showed extraordinarily strong blue phosphorescence and uncommon fluorescence colors under the DiamondView.
DS201808-1792
2018
Song, Z.Tang, S., Su, J., Lu, T., Ma, Y., Ke, J., Song, Z., Zhang, S., Liu, H.A thick overgrowth of CVD synthetic diamond on a natural diamond.Journal of Gemmology, Vol. 36, 2, pp. 134-141.Technologysynthetics

Abstract: In October 2017, a natural diamond overgrown by a thick layer of CVD synthetic diamond was identified at the Beijing laboratory of the National Gemstone Testing Center (NGTC). The round-brilliant-cut sample was near-colourless and weighed 0.11 ct. No sign of the overgrowth was observed with magnification. However, DiamondView images showed a distinct boundary in the pavilion separating layers of different luminescence: The upper layer displayed red fluorescence with greenish blue phosphorescence, while the lower portion showed deep blue fluorescence and no phosphorescence. Infrared spectroscopy revealed that the upper layer was type IIa and the lower portion was type Ia. Ultraviolet-visible-near infrared (UV-Vis-NIR) spectroscopy recorded an unusual co-existence of the N3 centre at 415 nm together with absorption due to [Si-V]-defects at 737 nm. The photoluminescence (PL) spectrum confirmed a high level of [Si-V]-defects. The approximate thickness of the CVD synthetic layer was ~740 µm, which is much thicker than previously reported for such overgrowths. The presence of the N3 centre in the natural diamond layer caused this sample to be passed as natural by various screening instruments. Luminescence imaging is key to identifying such overgrowths, and should be relied upon more heavily in the screening procedures used by gemmological laboratories in the future.
DS201901-0043
2018
Song, Z.Ke, J., Lu, T., Lan, Y., Song, Z., Tang, S., Zhang, J., Chen, H.Recent developments in detection and gemology in China, particularly for Chinese synthetic diamonds.Gems & Gemology, Sixth International Gemological Symposium Vol. 54, 3, 1p. Abstract p. 268.Chinasynthetics

Abstract: China is the world’s largest producer of HPHT-grown industrial diamonds. Its 2016 production of about 20 billion carats accounted for 98% of the global supply. Since the beginning of 2015, meleesized colorless HPHT synthetic diamonds have been tested at the National Gemstone Testing Center’s (NGTC) Shenzhen and Beijing laboratories in parcels submitted by different clients, which means that colorless HPHT synthetic diamonds have entered the Chinese jewelry market and may be mistaken for natural diamonds. CVD synthesis technology has grown rapidly in recent years. Large colorless and colored (blue, pink) CVD-grown diamonds have been entering the market, and a few have been fraudulently sold as natural diamonds. China has independently developed gem-grade HPHT synthetic diamond production technology since 2002, and can grow gem-grade type Ib, IIa, and IIb and high-nitrogen-content synthetic diamonds in volume, depending on market needs. Gemgrade type Ib, IIa, and IIb HPHT synthetic diamonds have been grown using the temperature gradient method, under a cubic press at high pressure (e.g., 5.4 GPa) and high temperature (1300-1600°C). Driven by a specific temperature gradient, the carbon source from high-purity graphite (>99.9%) located at the high-temperature zone can diffuse into the seed crystals in the cubic press, resulting in the crystallization of synthetic diamonds. Chinese production of melee-sized colorless to near-colorless HPHT synthetic diamonds accounts for about 90% of the global output. Gem-grade type IIa and IIb CVD synthetic diamonds are grown using the microwave plasma chemical vapor deposition (MPCVD) and direct current (DC) arc plasma methods. Faceted colorless CVD diamonds can be grown in sizes up to 6 ct by at least two Chinese companies (table 1). After testing and analyzing thousands of natural and synthetic diamonds collected directly from the Chinese companies, NGTC independently developed the GV5000, PL5000, DS5000, and ADD6000 instruments for rapidly screening and identifying the diamonds based on the gemological characteristics obtained. Besides HPHT and CVD synthetic diamonds, a thickly layered hybrid diamond consisting of both natural and CVD material was identified at the NGTC Beijing laboratory (figure 1). The identification features and properties of regrown CVD synthetic diamonds using natural type Ia diamond crystals as seeds will be reported. The current status and features of colored stones examined at NGTC laboratories, including several cases studies, will be discussed.
DS202010-1879
2020
Song, Z.Song, Z., Lu, T., Liu, H., Dai, H., Ke, J., Zhu, W., Zhang, J.Identification of Type IIa blue CVD diamonds from Huzhou SinoC semiconductor.Journal of Gemmology, Vol. 37, 3, pp. 306-313.Chinasynthetics

Abstract: Gemmological and spectroscopic characteristics are reported for two type IIa blue CVD synthetic diamonds from Huzhou SinoC Semiconductor Science and Technology Co. Ltd, China. These are the first relatively large (1.76 and 2.63 ct) blue CVD synthetics examined in NGTC’s laboratories, and their colour was slightly brighter than other blue synthetic diamonds that we have encountered. In the DiamondView, they fluoresced blue (with purple-red in one sample), which is unusual for CVD synthetics. The mid- and near-IR absorption spectra of one sample showed no hydrogen-related features, while the other synthetic diamond showed a weak absorption at 6853 cm?1attributed to hydrogen. The spectra of both samples had a very weak line at 1332 cm?1 due to isolated nitrogen and a distinct band at 9282 cm-1 related to radiation. A very strong GR1 absorption feature was detected by UV-Vis-NIR spectroscopy. Photoluminescence spectra obtained at liquid-nitrogen temperature recorded emissions related to radiation (mainly in the 480-510 nm region), N-V and [Si-V]- centres, and several unassigned weak emissions. This combination of optical centres strongly suggests that these samples underwent post-growth treatment to improve their transparency before they were irradiated to produce blue colouration.
DS1992-0062
1992
Song CaoBachu, S., Song CaoPresent and past geothermal regimes and source rock maturation, Peace River Arch area, CanadaAmerican Association of Petroleum Geologists Bulletin, Vol. 76, No. 10, October pp. 1535-1549AlbertaStructure, Peace River Arch
DS1988-0655
1988
Song ZijiSong Ziji, Zhang WeijiA discussion on the primary rock formation and forming conditions of the Kuan Ping group.*CHIYanshi Kuang. Zazhi, *CHI, Vol. 7, No. 2, pp. 118-126ChinaCarbonatite
DS2002-1527
2002
Songnian, L.Songnian, L., Chunliang, Y., Huaikun, L., Humin, L.A group of rfiting events in the termin al Paleoproterozoic in the North Chin a CratonGondwana Research, Vol. 5, No. 1, pp. 123-32.ChinaCraton, Tectonics
DS2002-0465
2002
Song-Suck-HwanFoden, J., Song-Suck-Hwan, Turner, S., Elburg, M., Smith, P.B., Van der StedtGeochemical evolution of lithospheric mantle beneath S.E. South AustraliaChemical Geology, Vol. 182, No. 2-4, pp. 663-95.AustraliaMagmatism
DS200612-0208
2006
Songyong, C.Cailai, W., Wooden, J.L., Jingsui, Y., Robinson, P.T., Lingsen, Z., Rendeng, S., Songyong, C.Granitic magmatism in the North Qaidam Early Paleozoic Ultra high pressure metamorphic belt, northwest China.International Geology Review, Vol. 48, 3, pp. 223-240.Asia, ChinaUHP
DS1985-0318
1985
Soni, M.K.Kameswara, R.T., Soni, M.K.A Review of Rewa Group (vindhyan Supergroup) with Reference Topaisun information in Panna Diamond Belt, Madhya PradeshRecords of the Geological Survey of India, pp. 107-123IndiaBlank
DS200712-1018
2007
Sonin, V.Sonin, V., Zhimulev, E., Afanasev, V., Fedorov, I., Cheperov, A.Diamond interaction with silicate melts in a hydrogen atmosphere.Geochemistry International, Vol. 45, 4, pp. 399-404.TechnologyMelting
DS200712-1019
2007
Sonin, V.Sonin, V., Zhimulev, E., Afanasev, V., Fedorov, I., Cheperov, A.Diamond interaction with silicate melts in a hydrogen atmosphere.Geochemistry International, Vol. 45, 4, pp. 399-404.TechnologyMelting
DS200712-1020
2006
Sonin, V.Sonin, V., Zhimulev, E., Fedorov, I., Cheperov, A.Effect of oxygen fugacity on the etching rate of diamond crystals in silicate melt.Geology of Ore Deposits, Vol. 48, 6, pp. 499-501.TechnologyDiamond morphology
DS200712-1021
2006
Sonin, V.Sonin, V., Zhimulev, E., Fedorov, I., Cheperov, A.Effect of oxygen fugacity on the etching rate of diamond crystals in silicate melt.Geology of Ore Deposits, Vol. 48, 6, pp. 499-501.TechnologyDiamond morphology
DS202002-0218
2019
Sonin, V.Sonin, V., Leech, M., Chepurov, A., Zhimulev, E., Chepurov, A.Why are diamonds preserved in UHP metamorphic complexes? Experimental evidence for the effect of pressure on diamond graphitization.International Geology Review, Vol. 61, 4, pp. 504-519.Russia, Chinacoesite, UHP

Abstract: The preservation of metastable diamond in ultrahigh-pressure metamorphic (UHPM) complexes challenges our understanding of the processes taking place during exhumation of these subduction zone complexes. The presence of diamonds in UHPM rocks implies that diamonds remained metastable during exhumation, and within thermodynamic stability of graphite for an extended period. This work studies the influence of pressure on the surface graphitization rate of diamond monocrystals in carbonate systems to understand the preservation of microdiamond during exhumation of UHP subduction complexes. Experiments were performed with 2-3 mm synthetic diamond monocrystals at 2-4 GPa in ????3 (1550°?) and ?2??3 (1450°?) melts using a high-pressure multi-anvil apparatus. The highest rate of surface graphitization took place at 2 GPa; diamond crystals were almost completely enveloped by a graphite coating. At 4 GPa, only octahedron-shaped pits formed on flat {111} diamond crystal faces. Our results demonstrate that the surface graphitization rate of diamonds in the presence of carbonate melts at 1450-1550°C increases with decreasing pressure. Decreased pressure alone can graphitize diamond regardless of exhumation rate. Metastable diamond inclusions survive exhumation with little or no graphitization because of excess pressure up to 2 GPa acting on them, and because inclusions are protected from interaction with C-O-H fluid.
DS202110-1606
2021
Sonin, V.Chepurov, A., Zhimulev, E., Chepurov, A., Sonin, V.Where did the largest diamonds grow? The experiments on percolation of Fe-Ni melt through olivine matrix in the presence of hydrocarbons.Lithos, Vol. 404-405, 106437, 10p. PdfMantlediamond genesis

Abstract: Recently it was found that large natural diamonds can grow from a metal liquid. One of the principal issues of the proposed hypothesis is the formation of so-called “pockets” filled with Fe-Ni melt and hydrocarbons in the Earth's mantle. The existing models of Fe migration imply percolation of liquid melt through interconnected interstices between silicate minerals, although these models face several fundamental problems in explaining the process of penetration of Fe melt between solid crystalline phases like silicate and oxide minerals. The aim of the present study is to contribute to the mechanism of Fe-Ni melt migration, and to elucidate the evolution of the "pockets" in the presence of hydrocarbons. The experiments were performed using a high-pressure apparatus "BARS" at pressures 3 and 5?GPa, and temperature 1600?°C. A silicate matrix consisting of natural olivine grains was used. The interstices in olivine were filled with anthracene that decomposes under high P-T into a complex hydrocarbon fluid. Percolation of Fe-Ni (64/36?wt%) melt through the interstices was demonstrated which occurred at relatively high rates. The basis of the proposed mechanism is "solubility-enhanced infiltration": Fe-Ni occupies the space filled with light elements or substances that are soluble in the melt. It is suggested that the following simple, but efficient mechanism supports the growth of large diamonds as well as their resorption and storage within silicate mantle of the Earth for a long time.
DS202112-1922
2021
Sonin, V.Chepurov, A., Sonin, V., Shcheglov, D., Zhimulev, E., Sitnikov, S., Yelisseyev, A., Chepurov, A.Surface porosity of natural crystals after the catalytic hydrogenation.Crystals, Vol. 11, 1341 9p pdfRussiadeposit - Popigai

Abstract: The study of diamond surfaces is traditionally undertaken in geology and materials science. As a sample material, two natural diamond crystals of type Ia were selected, and their luminescence and nitrogen state was characterized. In order to etch the surface catalytic hydrogenation was performed using Fe particles as an etchant. Micromorphology of the surface was investigated by scanning electron and laser confocal microscopy. It was demonstrated that etching occurred perpendicular to the crystal surface, with no signs of tangential etching. The average depth of caverns did not exceed 20-25 ?m with a maximal depth of 40 ?m. It is concluded that catalytic hydrogenation of natural type Ia diamonds is effective to produce a porous surface that can be used in composites or as a substrate material. Additionally, the comparison of results with porous microsculptures observed on natural impact diamond crystals from the Popigai astrobleme revealed a strong resemblance.
DS202112-1951
2021
Sonin, V.Sonin, V., Zhimulev, E., Chepurov, A., Gryaznov, I., Chepurov, A., Afanasiev, V., Poikilenko, N.Experimental etching of diamonds: extrapolation to impact diamonds from the Popigai Crater ( Russia)MDPI, Vol. 11, 11p. Pdf Russiadeposit - Popigai

Abstract: Diamond etching in high-temperature ambient-pressure experiments has been performed aimed to assess possible postimpact effects on diamonds in impact craters, for the case of the Popigai crater in Yakutia (Russia). The experiments with different etchants, including various combinations of silicate melts, air, and inert gases, demonstrated the diversity of microstructures on {111} diamond faces: negative or positive trigons, as well as hexagonal, round, or irregularly shaped etch pits and striation. The surface features obtained after etching experiments with kimberlitic diamonds are similar to those observed on natural impact diamonds with some difference due to the origin of the latter as a result of a martensitic transformation of graphite in target rocks. Extrapolated to natural impact diamonds, the experimental results lead to several inferences: (1) Diamond crystals experienced natural oxidation and surface graphitization during the pressure decrease after the impact event, while the molten target rocks remained at high temperatures. (2) Natural etching of diamonds in silicate melts is possible in a large range of oxidation states controlled by O2 diffusion. (3) Impact diamonds near the surface of molten target rocks oxidized at the highest rates, whereas those within the melt were shielded from the oxidizing agents and remained unchanged.
DS200812-1099
2008
Sonin, V.A.M.A.Sonin, V.A.M.A., Zhimulev, E.A.I.A., Chepurov, A.A.I.A., Fedorov, I.A.I.A.Diamond stability in NaCl and NaF melts at high pressure.Doklady Earth Sciences, Vol. 420, 1, pp. 641-643.TechnologyUHP
DS1985-0118
1985
Sonin, V.M.Chepurov, A.I., Khokhria, A.F., Sonin, V.M.The shapes of diamond crystal dissolution in silicate melt sunder highpressure.(Russian)Doklady Academy of Sciences Nauk. SSSR, (Russian), Vol. 285, No. 1, pp. 212-216RussiaDiamond Morphology
DS1987-0106
1987
Sonin, V.M.Chepurov, A.I., Khokhryakov, A.F., Sonin, V.M., Palyanov, Yu.N.Shapes derived by solution of diamond crystals in silicate melts at hightemperaturesDoklady Academy of Science USSR, Earth Science Section, Vol. 285, No. 1-6, August pp. 133-137RussiaBlank
DS1994-0299
1994
Sonin, V.M.Chepurov, A.I., Fedorov, A.I., Sonin, V.M., Sobolev, N.V.Diamond formation in the system (iron, nickel) S-C H at high pressure/temperature parameters. (Russian)Doklady Academy of Sciences Nauk. SSSR, (Russian), Vol. 336, No. 2, May pp. 238-240. # NR556RussiaDiamond genesis, Iron, nickel
DS1994-1666
1994
Sonin, V.M.Sonin, V.M., Bagryantsev, D.G., Federov, I.I., Chepurov.A.Formation of corrosion figures on diamond crystalsRussian Geology and Geophysics, Vol. 35, No. 6, pp. 57-61.RussiaDiamond morphology
DS1995-0306
1995
Sonin, V.M.Chepurov, A.I., Federov, I.I., Sonin, V.M.Experimental simulation of diamond genesisProceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 109.GlobalPetrology -experimental, Diamond genesis
DS1996-0267
1996
Sonin, V.M.Chepurov, A.I., Fedorov, I.I., Sonin, V.M., Sobolev, N.V.Diamond formation in the system (iron, nickel)-S-C-H at high pressures andtemperatures.Doklady Academy of Sciences, Vol. 338, No. 7, Jan. pp. 61-65.GlobalPetrology -experimental, Diamond genesis
DS1996-0268
1996
Sonin, V.M.Chepurov, A.I., Sonin, V.M., Khokhryakova, I.P.Interaction of free state metals with diamond under high temperatureannealing.Russian Geology and Geophysics, Vol. 36, No. 7, pp. 61-68.RussiaDiamond synthesis
DS1997-1086
1997
Sonin, V.M.Sonin, V.M., Zhiumulev, E.I., Fedorov, I.I., Osorgin, N.Y.Etching of diamond crystals in silicate melt in the presence of aqueous fluid under high pressure-T parameters.Geochemistry International, Vol. 35, No. 4, pp. 393-397.GlobalPetrology - experimental, Diamond morphology
DS1998-0243
1998
Sonin, V.M.Chepurov, A.I., Fedorov, I.I., Sonin, V.M.Experimental studies of diamond formation at high pressureT parameters (supplement to model for natural diamond).Russian Geology and Geophysics, Vol. 39, No. 2, pp. 240-9.GlobalDiamond morphology, Pressure, metamorphism
DS1998-1382
1998
Sonin, V.M.Sonin, V.M., Chepurov, A.I., Afasev, V.P., Zinchuk, N.N.The origin of discoid sculptures on diamond crystalsDoklady Academy of Sciences, Vol. 361, No. 5, pp. 635-7.GlobalDiamond morphology
DS1999-0695
1999
Sonin, V.M.Sonin, V.M., Bagriantsev, D.G., Turkin, A.I., Babich, Y.Formation of pseudohemimorphic diamond crystals during dissolution in a thermal gradient.in RUSSIAN.Proceedings Russ. Min. Soc., (Russian), Vol. 28, No. 1, pp. 122125.GlobalDiamond morphology
DS2000-0916
2000
Sonin, V.M.Sonin, V.M., Federov, I.I., Pokhilenko, L., PokhilenkoDiamond oxidation rate as related to oxygen fugacityGeol. Ore Dep., Vol. 42, No. 6, pp. 496-503.RussiaDiamond - geochemistry
DS2001-1105
2001
Sonin, V.M.Sonin, V.M., Zhimulev, Fedorov, Tomilenko, ChepurovEtching of diamond crystals in a dry silicate melt at high pressure-temperature parameters.Geochemistry International, Vol. 39, No. 3, pp. 268-74.GlobalDiamond - experimental petrology, Morphogenesis
DS2002-1528
2002
Sonin, V.M.Sonin, V.M., Zhimulev, E.I., Afanasev, V.P., Chepurov, A.I.Genetic aspects of the diamond morphologyGeology of Ore Deposits, Vol. 44, 4, pp. 291-299.GlobalDiamond - morphology, genesis
DS2003-1315
2003
Sonin, V.M.Sonin, V.M., Zhimulev, .I., Chepurov, A.I., Afanesev, V.P., Tomileno, A.A.Etching of diamond crystals in the system silicate melt C O H S fluid under a highGeochemistry International, Vol. 41, 7, pp. 688-93.GlobalDiamond - morphology
DS200412-1881
2003
Sonin, V.M.Sonin, V.M., Zhimulev, .I., Chepurov, A.I., Afanesev, V.P., Tomileno, A.A.Etching of diamond crystals in the system silicate melt C O H S fluid under a high pressure.Geochemistry International, Vol. 41, 7, pp. 688-93.TechnologyDiamond - morphology
DS200412-1882
2004
Sonin, V.M.Sonin, V.M., Zhimulev, E.I., Tomilenko, A.A., Chepurov, S.A., Chepurov, A.I.Chromatographic study of diamond etching in kimberlitic melts in the context of diamond natural stability.Geology of Ore Deposits, Vol. 46, 3, pp. 182-190.TechnologyDiamond morphology
DS200412-2228
2004
Sonin, V.M.Zhimulev, E.I., Sonin, V.M., Fedorov, I.I., Tomilenko, A.A., Pkhilenko, L.N., Chepurov, A.I.Diamond stability with respect to oxidation in experiments with minerals from mantle xenoliths at high P T parameters.Geochemistry International, Vol. 42, 6, pp. 520-525.MantleDiamond morphology, etching
DS200612-0390
2006
Sonin, V.M.Fedorov, I.I., Chepurov, A.I., Sonin, V.M., Zhimulev, E.I.Experimental study of the effect of high pressure and high temperature on silicate and oxide inclusions in diamonds.Geochemistry International, Vol. 44, 10, pp. 1048-1052.TechnologyUHP, diamond inclusions
DS200712-0306
2006
Sonin, V.M.Fedorov, I.I., Chepurov, A.I., Sonin, V.M., Zhimulev, E.I.Experimental study of the effect of high pressure and high temperature on silicate and oxide inclusions in diamonds.Geochemistry International, Vol. 44, 10, pp. 1048-TechnologyUHP - diamond inclusions
DS200712-1022
2007
Sonin, V.M.Sonin, V.M., Zhimulev, E.I., Afanasev, V.P., Fedorov, I.I., Chepurov, A.I.Diamond interaction with silicate melts in a hydrogen atmosphere.Geochemistry International, Vol. 45, 4, pp. 399-404.MantleDiamond genesis
DS200712-1023
2006
Sonin, V.M.Sonin, V.M., Zhimulev, E.I., Fedorov, I.I., Chepurov, A.I.Effect of oxygen fugacity on the etching rate of diamond crystals in silicate melt.Geology of Ore Deposits, Vol. 48, 6, pp. 499-501.TechnologyDiamond morphology
DS200812-0216
2008
Sonin, V.M.Cheperuv, A.I., Federov, I.I., Sonin, V.M., Logvinova, A.M., Chepurov, A.A.Thermal effect on sulfide inclusions in diamonds ( from experimental data).Russian Geology and Geophysics, Vol. 49, 10, pp. 738-742.TechnologyThermometry
DS200812-0217
2008
Sonin, V.M.Chepunov, A.I., Fedorov, I.I., Sonin, V.M., Logvinova, A.M., Chepunov, A.A.Thermal effect on sulfide inclusions in diamonds ( from experimental data).Russian Geology and Geophysics, Vol. 49, pp. 738-742.Russia, YakutiaTechnology - sulphide inclusions, UHP
DS200812-0341
2008
Sonin, V.M.Federov, I.I., Chepurov, A.I., Sonin, V.M., Chepurov, A.A., Logvina, A.M.Experimental and thermodynamic study of the crystallization of diamond and silicates in a metal silicate carbon system.Geochemistry International, Vol. 46, 4, pp. 340-350.TechnologyGeochemistry - diamond
DS200912-0111
2009
Sonin, V.M.Chepurov, A.I., Zhimulev, E.I., Eliseev, A.P., Sonin, V.M., Federov, I.I.The genesis of low - N diamonds.Geochemistry International, Vol. 47, 5, pp. 522-525.TechnologyType IIa
DS200912-0112
2009
Sonin, V.M.Chepurov, A.I., Zhimulev, E.I., Sonin, V.M., Chepurov, A.A., Pokhilenko, N.P.Crystallization of diamond in metal sulfide melts.Doklady Earth Sciences, Vol. 428, 1, pp. 1139-1141.MantleDiamond morphology, geochemistry
DS200912-0863
2009
Sonin, V.M.Zhimulev, E.I., Sonin, V.M., Chepurov, A.I., Tomilenko, A.A.Chromatographic study of formation conditions of rhombododecahedral diamond crystals.Geology of Ore Deposits, Vol. 51, 3, pp. 243-246.TechnologyDiamond morphology
DS201012-0741
2010
Sonin, V.M.Sonin, V.M., Zhimulev, E.I., Chepurov, A.I., Afanasev, V.P., Pokhilenko, N.P.High pressure etching of diamond in chloride melt in the presence of aqueous fluid.Doklady Earth Sciences, Vol. 434, 2, pp. 1359-1361.TechnologyUHP
DS201112-0182
2011
Sonin, V.M.Chepurov, A.I., Zhimulev, E.I., Sonin, V.M., Chepurov, A.A., Tomilenko, A.A., Pokilenko, N.P.Experimental estimation of the rate of gravitiation fractioning of xenocrysts in kimberlite magma at high P-T parameters.Doklady Earth Sciences, Vol. 440, 2, pp. 1427-1430.MantleDiamond genesis
DS201212-0830
2012
Sonin, V.M.Zhimulev, E.I., Chepuruv, A.I., Sinyakova, E.F., Sonin, V.M., Chepurov, A.A.Diamond crystallization in the Fe-Co-SC and Fe-Ni-S C systems and the role of sulfide metal melts in the genesis of diamond.Geochemistry International, Vol. 50, 3, pp. 205-216.TechnologyDiamond genesis
DS201312-0153
2012
Sonin, V.M.Chepurov, A.I., Sonin, V.M., Chepurov, A.A., Zhimulev, E.I., Kosolobov, S.S., Sobolev, N.V.Diamond interaction with ultradispersed particles of iron in a hydrogene environment: surface micromorphology.Doklady Earth Sciences, Vol. 447, 1, pp. 1284-1287.TechnologyMineralogy
DS201312-0154
2013
Sonin, V.M.Chepurov, A.I., Zhimulev, E.I., Agafonov, L.V., Sonin, V.M., Chepurov, A.A., Tomilenko, A.A.The stability of ortho- and clinopyroxenes, olivine and garnet in kimberlitic magma.Russian Geology and Geophysics, Vol. 54, 4, pp. 406-415.RussiaMineral chemistry
DS201312-0649
2012
Sonin, V.M.Nikolenko, E.I., Afanasev, V.P., Chepurov, A.I., Sonin, V.M., Poikhilenko, N.P.Experimental study of the interaction between emoilmenite and kimberlite melt at a pressure of 2 Gpa.Doklady Earth Sciences, Vol. 447, 2, pp. 1306-1309.Africa, GuineaDeposit - Massadou
DS201312-0869
2012
Sonin, V.M.Sonin, V.M., Chepurov, A.A., Shcheglov, D.V., Kosolobov, S.S., Logvinova, A.M., Chepurov, A.I., Latyshev, A.V., Sobolev, N.V.Study of the surface of natural diamonds by the method of atomic force microscopy.Doklady Earth Sciences, Vol. 447, 2, pp. 1314-1316.TechnologyDiamond morphology
DS201312-0870
2013
Sonin, V.M.Sonin, V.M., Chepurov, A.I., Zhimulev, E.I., Chepurov, A.A.Surface graphitization of diamond in K2C03 melt at high pressure.Doklady Earth Sciences, Vol. 451, 2, pp. 858-860.TechnologyUHP
DS201702-0258
2016
Sonin, V.M.Zhimulev, E.I., Sonin, V.M., Afanasiev, V.P., Chepuov, A.I., Pokhilenko, N.P.Fe-S melt as a likely solvent of diamond under mantle conditions.Doklady Earth Sciences, Vol. 471, 2, pp. 1277-1279.MantleDiamond morphology

Abstract: The first results of experimental study of diamond dissolution in a S-bearing Fe melt at high P-T parameters are reported and the morphology of partially dissolved crystals is compared with that of natural diamonds. Our results show that under the experimental conditions (4 GPa, 1400°C), flat-faced octahedral diamond crystals are transformed into curve-faced octahedroids with morphological features similar to those of natural diamonds.
DS201705-0892
2017
Sonin, V.M.Zhimulev, E.I., Sonin, V.M., Afanasiev, V.P., Chepurov, A.I., Pokhilenko, N.P.Fe-S melt as a likely solvent of diamond under mantle conditions.Doklady Earth Sciences, Vol. 471, 2, pp. 1277-1279.MantleDiamond morphology

Abstract: The first results of experimental study of diamond dissolution in a S-bearing Fe melt at high P-T parameters are reported and the morphology of partially dissolved crystals is compared with that of natural diamonds. Our results show that under the experimental conditions (4 GPa, 1400°C), flat-faced octahedral diamond crystals are transformed into curve-faced octahedroids with morphological features similar to those of natural diamonds.
DS201709-1972
2017
Sonin, V.M.Chepurov, A.A., Kosolobov, S.S., Shcheglov, D.V., Sonin, V.M., Chepurov, A.I., Latyshev, A.V.Nanosculptures on round surfaces of natural diamonds.Geology of Ore Deposits, Vol. 59, 3, pp. 256-264.Russiadeposit - Udachnaya -East

Abstract: The results of a study using scanning electron microscopy and atomic force microscopy comprising the micromorphology of the ditrigonal and trigonal layers on surfaces near the edges of octahedral diamond crystals from the Udachnaya-Eastern kimberlite pipe in Yakutia are presented. The studied surface sculptures are elongated parallel to the direction ?111? and have similar morphological features, characterized by a wavy profile across the lamination, the absence of flat areas at the micro- and nanolevel. It is proposed that both sculpture types were formed as a result of dissolution under natural conditions. This suggestion is corroborated by the revelation of negative trigons on the octahedral facets of the studied diamonds.
DS201804-0740
2018
Sonin, V.M.Sonin, V.M., Zhimulev, E.I., Pomazanskiy, B.S., Zemnuhov, A.L., Chepurov, A.A., Afanasiev, V.P., Chepurov, A.I.Morphological features of diamond crystals dissolved in Fe0.7 S0.3 melt at 4GPa and 1400.Geology of Ore Deposits, Vol. 60, pp. 82-92.Technologydiamond morphology

Abstract: An experimental study of the dissolution of natural and synthetic diamonds in a sulfur-bearing iron melt (Fe0.7S0.3) with high P-T parameters (4 GPa, 1400°?) was performed. The results demonstrated that under these conditions, octahedral crystals with flat faces and rounded tetrahexahedral diamond crystals are transformed into rounded octahedroids, which have morphological characteristics similar to those of natural diamonds from kimberlite. It was suggested that, taking into account the complex history of individual natural diamond crystals, including the dissolution stages, sulfur-bearing metal melts up to sulfide melts were not only diamond-forming media during the early evolution of the Earth, but also natural solvents of diamond in the mantle environment before the formation of kimberlitic melts.
DS201809-2011
2018
Sonin, V.M.Chepurov, A.A., Sonin, V.M., Chepurov, A.I., Tomilenko, A.A.The effects of the concentration of olivine xenocrysts on the viscosity of kimberlite melts: experimental evidence.Journal of Volcanology and Seismology, Vol. 12, 2, pp. 140-149.Russiadeposit- Nyurbinskaya

Abstract: The study of viscosity in sub-liquidus heterogeneous media, which includes kimberlite magma at the pressures and temperatures that prevail in the mantle, is an urgent task. We have conducted experiments in the serpentine-olivine, serpentine-CaCO3?olivine, and native kimberlite-olivine systems at a pressure of 4 GPa and temperatures of 1400?1600°? in a BARS high-pressure device using the technique of a falling Pt pellet. The samples were examined after experiments to find fine-grained chilled mass of crystals where the Pt pellet was observed at the time of chilling. The concentration of the solid phase was varied in the experiments between 10 and 50 wt %. We showed that when 50 wt % of olivine grains has been introduced, it was not possible to detect the motion of the Pt pellet, while when the concentration of olivine xenocrysts reached 10 wt %, the Pt pellet very rapidly descended to the bottom of the reaction volume. Viscosity was calculated using the Stokes method. We found that the viscosity of a homogeneous kimberlite melt at 4 GPa and 1600°? is below 2 Pa s, with the viscosity of a melt that contained up to 10 wt % of the solid phase being approximately constant. A kimberlite melt that contained 30 wt % of the solid phase had a viscosity on the order of 100 Pa s, while with 50 wt % of the solid phase the relative viscosity of an ultrabasic system increased to reach values over 1000 Pa s.
DS201809-2094
2018
Sonin, V.M.Sonin, V.M., Zhimulev, E.I., Chepurov, A.A., Chepurov, A.I., Pokhilenko, N.P.Influence of the sulfur concentration in the Fe-S melt on diamond preservation under P-T conditions of the Earth's mantle.Doklady Earth Sciences, Vol. 481, 1, pp. 922-924.Mantlegeochemistry

Abstract: The results of experiments on dissolution of diamond in a Fe melt with variable concentrations of S at high P-T parameters are presented. It is established that the maximal degree of diamond dissolution occurs at a sulfur concentration of 15 wt %. With decreasing or increasing S content, dissolution of diamond slows down and almost does not occur during the period of the experiment (60 min), when the "eutectic" composition is gained. In contrast to a pure Fe melt, the presence of S decreases the carbon solubility and, therefore, reduces the aggressiveness of metal melt in relation to diamonds, thus, stimulating their preservation in the Earth’s mantle, especially if the concentration of S exceeds that in the "eutectic" composition.
DS201811-2613
2018
Sonin, V.M.Tomilenko, A.A., Zhimulev, E.I., Bulbak, T.A., Sonin, V.M., Chepurov, A.I., Pokhilenko, N.P.Peculiarities of the composition of volatiles of diamonds synthesized in the Fe-S-C system: data on gas chromatography - mass spectrometry.Doklady Earth Sciences, Vol. 482, 1, pp. 1207-1211.Russiaspectrometry

Abstract: The first chromatography-mass spectroscopy data on volatiles in diamonds synthesized in the Fe-S-C system with 5 wt % S at 1400-1450°C and 5.0-5.5 GPa indicate the evolution of volatile composition during the diamond growth and, correspondingly, the variation in redox conditions of the reaction cell. A significant role is played by various hydrocarbons (HCs) and their derivatives, the content of which can reach 87%. Our data on possible abiogenic synthesis of HCs (components of natural gas and oil) can result in global recalculations (including climate) related to the global C cycle.
DS202005-0735
2020
Sonin, V.M.Gryaznov, I.A., Zhimulev, E.I., Sonin, V.M., Lindenblot, E.S., Chepurov, A.A.Morphological features of diamond crystals resulting from dissolution in a Fe-Ni-S melt under high pressure.Doklady Earth Sciences, Vol. 489, 2, pp. 1449-1452 .pdfRussiadiamond morphology, CLIPPIR

Abstract: The primary results are presented on the dissolution of plane-faced diamond crystals of octahedral habit in a Fe-Ni-S melt under 3.5 GPa and 1400°C. It was found that the dissolution resulted in the transformation of plane-faced into curve-faced individuals of morphological features characteristic for kimberlite diamonds. It was concluded that the diamond forms as such might have formed in reduced domains of the Earth’s mantle before becoming involved in the kimberlite magma.
DS202007-1130
2020
Sonin, V.M.Cheperov, A.I., Sonin, V.M., Zhimulev, E.I., Cheperov, A.A.Preservation conditions of CLIPPIR diamonds in the Earth's mantle in a heterogeneous metal-sulphide-silicate medium ( experimental modeling).Journal of Mineralogical and Petrological Sciences, Vol. 115, pp. 236-246. pdfMantlediamond inclusions

Abstract: The genesis of CLIPPIR diamonds (Cullinan-like, large, inclusion-poor, pure, irregular, and resorbed) have attracted much interest due to their possible crystallization from metal melt in deep horizons of the earth’s mantle. These diamonds usually show a pronounced resorption and irregular morphology. The present paper reports new experimental data on the dissolution of diamond crystals at high P-T parameters in Fe-S melt containing large amounts of silicate components (5-20 wt%). The experiments were performed using a split-sphere multi-anvil apparatus (BARS) at a pressure of 4 GPa and a temperature of 1450 °C. The samples consisted of natural diamond crystals placed in mixtures of Fe, S, and kimberlite. Wide variations in dissolution rates of diamond crystals were obtained. The absence of diamond dissolution in a heterogeneous medium indicates that the amount of solid silicate phases present in metal melt plays a role in the preservation of diamonds. This study demonstrated how diamonds can be stored in natural environments due to the heterogeneity of the medium composition which could insulate diamonds from the metal-sulphide melt. The obtained results improve our understanding of processes that lead to preservation of CLIPPIR diamonds in the deep mantle.
DS202008-1379
2020
Sonin, V.M.Chepurov, A.I., Tomilenko, A.A., Sonin, V.M., Zhimulev, E.I., Bulbak, T.A., Cheperov, A.A., Sobolev, N.V.Interaction of an Fe-Ni melt with anthracene ( C14H10) in the presence of olivine at 3 Gpa: fluid phase composition.Doklady Earth Sciences, Vol. 492, pp. 333-337.MantleUHP, diamond

Abstract: The first results on the interaction between an Fe-Ni melt and anthracene (?14?10) in the presence of olivine at 3 GPa and 1500°? and on the study of the component composition of the fluid generated in this process are presented. The stability of aliphatic hydrocarbons in the implemented conditions is confirmed experimentally. It is established that, under these conditions, crystallization of high-magnesian olivines occurs (Fo = 97-98 mol %). The composition of the fluid is similar to the composition of the fluid from inclusions in synthetic diamonds. The conditions implemented in the experiment might have occurred at the early stages of the Earth’s evolution.
DS202010-1880
2020
Sonin, V.M.Sonin, V.M., Tomilenko, A.A., Zhimulev, E.I., Bulbak, T.A., Timina, T.Y., Chepurov, A.I., Pokhilenko, N.P.Diamond crystallization at high pressure: the relative efficiency of metal graphite and metal carbonate systems.Doklady Earth Sciences, Vol. 493, 1, pp. 508-512.RussiaUHP

Abstract: Data on the interaction of the Fe-Ni melt with CaCO3 and graphite at 5 GPa and 1400°? under the thermogradient conditions used in experiments on the growth of diamond on the BARS high-pressure apparatus are presented. The phase composition and component composition of the fluid captured by diamonds in the form of inclusions were studied by gas chromatography-mass spectrometry (GC-MS). Diamonds were synthesized from graphite. During the interaction of the Fe-Ni melt with CaCO3, Ca-Fe oxides and (Fe, Ni)3C carbide were formed. The stability of heavy hydrocarbons under the experimental conditions was confirmed. It was established that the composition of the fluid in synthesized diamonds is close to the composition of the fluid from inclusions in some natural diamonds. Nevertheless, it was concluded that crystallization of large diamonds under natural conditions is hardly possible due to the filling of the main crystallization volume with refractory oxide phases.
DS202104-0609
2020
Sonin, V.M.Sonin, V.M., Zhimulev, E.I., Chepurov, A.A., Lindenblot, E.S., Loginova, A.M., Shcheglov, D.V., Pomazanskii, B.S., Afanasiev, V.P., Chepurov, A.I.Dissolution of natural octahedral diamonds in an Fe-S melt at high pressure.Geology of Ore Deposits, Vol. 62, 6, pp. 497-507. pdfRussia, Yakutiadeposit Yubileinaya

Abstract: An experimental study was carried out on the dissolution of natural octahedral diamonds from the Internatsionalnaya and Yubileinaya kimberlite pipes (Yakutia) in an Fe-S melt at 4 GPa and 1450-1500°C with different sulfur contents (10-25 wt %). It was found that with an increase in sulfur content in the iron melt, the degree of diamond dissolution sharply decreases. The stationary (final) shape of diamond crystal dissolution under the achieved conditions corresponds to an octahedroid with trigonal etching layers, which is confirmed by photogoniometry. Diamonds with similar morphology are common in kimberlite pipes, especially in mantle xenoliths from kimberlites. It was concluded that diamonds with this shape did not undergo natural dissolution in a kimberlite magma, but, similar to flat-faced octahedra, were probably isolated from it in xenoliths. Therefore, the higher the content of octahedroid-shaped diamonds with trigonal layers in a deposit, the smaller the direct influence of an aggressive kimberlite magma on the diamond content.
DS202107-1135
2021
Sonin, V.M.Sonin, V.M., Gryaznov, I.A., Chepurov, A. I., Pokhilenko, N.P.H2O as a possible initiator of surface graphitization of impact diamonds.Doklady Earth Sciences, Vol. 498, 1, pp. 388-391.Russiadiamond crystallography
DS1998-1383
1998
Sonnenthal, E.L.Sonnenthal, E.L., McBirney, A.R.The Skaergaard layered series. Pt. IV. Reaction-transport simulations of foundered blocksJournal of Petrology, Vol. 39, No. 4, Apr. pp. 633-661GreenlandCrystallization, Melt composition, convection
DS1990-1395
1990
Sonoki, I.K.Sonoki, I.K., Garda, G.M.K-Ar ages of alkaline rock from Southern Brasil and Eastern Paraguay:compilation and adaptation of new decay constants. (in Portugese).National Technical Information Service Rept, No. DE90635110/WNR 17p. United States Sales $ 15.00 AO3Brazil, ParaguayAlkaline rocks, Geochronology
DS2000-0917
2000
Sonora Diamond CorpSonora Diamond CorpListing requirements for TSE being reviewedSonora Diamond Corp., July 20, 1p.GlobalNews item - press release
DS2000-0918
2000
Sonora Diamond CorpSonora Diamond CorpCease trading order rescinded... filings up to dateSonora Diamond Corp., Nov. 21, 1p.GlobalNews item - press release
DS1987-0703
1987
Soo Meen WeeSoo Meen Wee, Wilband, J.T.Geochemistry and the tectonic significance of early Proterozoic (X) dike swarms ,northern Michigan and northeastern WisconsinEos, Vol. 68, No. 44, November 3, p. 1518. Abstract onlyMichigan, WisconsinTectonics
DS1987-0704
1987
SOO MEEN WEESOO MEEN WEE, Wilband, J.T.Geochemistry and tectonic significance of early Proterozoic Dike swarms Northern Michigan and Northeastern WisconsinEos, Vol. 68, No. 44, November 3, p. 1518. Abstract onlyMichigan, WisconsinBlank
DS1989-1433
1989
Soo Meen WeeSoo Meen Wee, Wiband, J.T.Geochemistry, petrogenesis and tectonic significance of early Proterozoicigneous rocks of The upper Peninsula of Michigan, USAGeological Association of Canada (GAC) Annual Meeting Program Abstracts, Vol. 14, p. A95. (abstract.)MichiganPetrology, Tectonics
DS1999-0696
1999
Soofi, M.A.Soofi, M.A., King, S.D.A modified beam analysis effect of lateral forces on lithospheric flexure and its implication -post rift..Tectonophysics, Vol. 306, No. 2, June 15, pp. 149-62.United StatesTectonics, Midcontinent Rift system
DS2002-1529
2002
Soofi, M.A.Soofi, M.A., King, S.D.Post rift deformation of the Midcontinent rift under Grenville tectonismTectonophysics, Vol. 359, No. 3-4, pp. 209-23.Ontario, AppalachiaTectonics - rifting
DS1997-1091
1997
Soole, P.Speight, H.E., Soole, P., Wu, X.Development of an integrated automated, terrestrial photogrammetric system for mine mapping, planning..Australian Institute of Mining and Metallurgy (AusIMM) Bulletin, No. 6, Sept, pp. 21-37AustraliaMining, mapping, Safety, GIS, photogrammetry
DS1993-1703
1993
Soon MeenWee, Soon MeenGeochemical evidence for the tectonic setting of early Proterozoic metavolcanic sequences in southern Lake Superior regionJournal of Mining and Petrology, Economic Geology, Vol. 88, pp. 320-334MichiganTectonics, Petrology
DS202203-0366
2021
Soonthorntantikul, W.Soonthorntantikul, W., Atikarnsakul, U., Vertriest, W.Blue sapphires from Mogok, Myanmar: a gemological review.Gems & Gemology, Vol. 57, pp. 292-317.Asia, Myanmarsapphire

Abstract: Burmese sapphires are among the most coveted colored gemstones in the world. The historical importance of this source and the fine quality of its high-grade material contribute to the legendary status of these gems. Since Mogok is such a long-known source, there are many classic studies available, but modern analytical data are often missing or not up to current standards. This article summarizes the characteristics of Burmese sapphires, including standard gemological properties, inclusion observations, and spectroscopic and trace element analyses. This information was collected from hundreds of blue sapphires that GIA's field gemologists sampled while visiting different mining regions in Mogok over the past decade. Our observations indicate that these sapphires show a wide range of blue color intensities but very consistent inclusion scenes. Trace element chemistry did not show any significant differences between various regions apart from a wider range of Fe concentrations in sapphires from north of Mogok. Rare observations such as orange fluorescence and unusual FTIR spectra can be attributed to the chemical compositions of the sapphires.
DS1999-0686
1999
Soper, N.J.Smith, M.P., Soper, N.J., Criag, L.E.Paleokarst systems in the Neoproterozoic of eastern North Greenland in relation to extensional tectonics..Journal of Geological Society of London, Vol. 156, No. 1, Jan. pp. 113-24.GreenlandLaurentian margin, Tectonics, Geomorphology
DS1990-1396
1990
Sopher, S.R.Sopher, S.R.Brasil's climate should warm up. Opposing foreign investment would limit exploration opportunitiesEngineering and Mining Journal, Vol. 191, No. 7, July pp. 32-36BrazilEconomics, Exploration activities
DS1995-0526
1995
Sopuck, V.Fedorowich, J.S., Jain, J.C., Kerrich, R., Sopuck, V.Trace element analysis of garnet by laser-ablation microprobe ICP-MS....pyrope garnet.Canadian Mineralogist, Vol. 33, No. 2, April pp. 469-480.Wyoming, South AfricaGarnet -mass spectrometry, Deposit -Schaffer, Frank Smith
DS202102-0200
2020
Sorcar, N.Joshi, K.B., Sorcar, N., Pant, N.C., Nandakumar, V., Ahmad, T., Tomson, J.K.Characterization of multiple episodes of melt generation from lower crust during Archean using amphibole composition.Episodes, doi.org/10.18814/ epiiugs/2020 /020092 24p. PdfIndiaCraton - Bundelkhand

Abstract: Spatial association of tonalite trondhjemite granodiorites (TTGs) and high-K granitoids (anatectic and hybrid granites) from the Bundelkhand Craton (BC), Central India, is well known. Geochronological data indicates multiple episodes of formation of these high silica rocks showing a spread of ~1 Ga during Paleo to Neoarchaean. In the present study, we try to understand the evolution of TTGs and high-K granitoids (hybrid granites) from the BC using amphibole composition. The amphibole in both TTGs and high-K granitoids (hybrid granites) from the BC are characterised as magmatic, zoned, and calcic in nature. We find that the amphibole composition of the studied rocks is dominated by magnesiohornblende along with less common occurrence of tschermakite, magnesiohastingsite and edenite. Overall variation in amphibole compositions in terms of exchange vectors show a well defined linear trend (except for a late stage low-grade metamorphic readjustment), which suggests melt control over crystallization and evolution of amphibole chemistry. Moreover, the geothermobarometric analysis points towards higher pressure formation of TTGs in comparison to that of high-K granitoids (hybrid granites), with nearly the same temperature conditions in both the cases. Combining all our findings, we propose the evolution of the two considered rock types through lower crustal melting under varying PH2O conditions at different depths of emplacement.
DS1950-0237
1955
Sorensen, H.Sorensen, H.A Preliminary Note on Some Peridotites from Northern NorwayNorsk Geol. Tidsskr., Vol. 35, PP. 93-104.Norway, ScandinaviaPetrography
DS1950-0238
1955
Sorensen, H.Sorensen, H.A Petrographical and Structural Study of the Rocks Around The Peridotite at Engenbrae, Holandsfjord, Northern Norway.Norges Geol. Unders. Skr., No. 191, PP. 71-102.Norway, ScandinaviaTectonics, Petrography
DS1989-1434
1989
Sorensen, H.Sorensen, H.The crustal origin of eclogite -static or dynamicIn: Bridgewater, D. Fluid movements -element transport and the composition, pp. 121-123GlobalEclogite, Origin
DS1992-1455
1992
Sorensen, H.Sorensen, H.Agpaitic nepheline syenites: a potential source of rare elementsApplied Geochemistry, Vol. 7, pp. 417-427Brazil, China, Greenland, RussiaRare earths, Nepheline syenites
DS1993-0030
1993
Sorensen, H.Andersen, T., Sorensen, H.Crystallization and metasomatism of nepheline syenite xenoliths in quartz bearing intrusive rocks in the Permian Oslo rift, southeast Norway.Norsk Geologisk Tidskrift, Vol. 73, pp. 250-266.NorwayXenoliths
DS200612-0073
2006
Sorensen, H.Bailey, J.C., Sorensen, H., Andersen, T., Kogarko, L.N., Rose-Hansen, J.On the origin of microrhythmic layering in arfvedsonite lujavrite from the Ilimaussaq alkaline complex, South Greenland.Lithos, in press availableEurope, GreenlandAlkalic
DS200612-1337
2006
Sorensen, H.Sorensen, H., Bohse, H., Bailey, J.C.The origin and mode of emplacement of lujavrites in the Ilmaussaq alkaline complex, South Greenland.Lithos, in press availableEurope, GreenlandAlkaline rocks, agpaitic nepeheline syenites
DS1996-1350
1996
Sorensen, H.S.Sorensen, H.S., Wilson, J.R.Petrology of the Treknattan intrusion in the Fongen-Hyllingen complex Trondheim region: layered..Lithos, Vol. 38, pp. 109-127NorwayLayered intrusion, troctolite, Dioritic Fongen-Hyllingen
DS1996-1413
1996
Sorensen, H.S.Tegner, C., Robnins, B., Sorensen, H.S.Crystallization from stratified magmas in the Honningsvag intrusive Suite:a reappraisalMineralogical Magazine, Vol. 60, No. 1, Feb pp. 41-52NorwayMagma -layered intrusive, Honningsvag
DS200512-0014
1998
Sorensen, P.G.Andersen, A.C., Jorgensen, U.G., Nicolaisen, F.M., Sorensen, P.G., Glejbal, K.Spectral features of presolar diamonds in laboratory and in carbon star atmospheres.Astronomy and Astrophysics, Vol. 330, pp. 1080-1090.Meteorite
DS1990-0689
1990
Sorensen, S.Hickmott, D.D., Sorensen, S., Rogers, P.Trace element abundances in minerals from a metasomatized garnet-amphibolite Catalin a schist ,southern CaliforniaGeological Society of America (GSA) Annual Meeting, Abstracts, Vol. 22, No. 7, p. A349CaliforniaGeochemistry, Pixie trace elements
DS1984-0700
1984
Sorensen, S.S.Sorensen, S.S.Trace Element Effects of Eclogite/peridotite Metasomatism, Catalin a schist Terrane, Southern California.Geological Society of America (GSA), Vol. 16, No. 6, P. 663. (abstract.).United States, California, West CoastBlank
DS1997-1087
1997
Sorensen, S.S.Sorensen, S.S., Grossman, J.N.Phengite hosted large-ion lithophile elements (LILE) enrichment in eclogite and related rocks: Implications for fluid mediated mass transferJournal of Petrology, Vol. 38, No. 1, Jan. 1, pp. 3-34.MantleMagma genesis, Subduction
DS2003-0228
2003
Sorensen, S.S.Catlos, E.J., Sorensen, S.S.Phengite based chronology of K and Ba rich fluid flow in two paleosubduction zonesScience, No. 5603, Jan. 3, pp. 92-95.GlobalSubduction, Tectonics
DS200612-1442
2006
Sorensen, S.S.Tsujimori, T., Sisson, V.B., Liou, J.G., Harlow, G.E., Sorensen, S.S.Windows to the very low temperature subduction process: a review of worldwide lawsonite eclogites.International Mineralogical Association 19th. General Meeting, held Kobe, Japan July 23-28 2006, Abstract p.207.MantleSubduction
DS200612-1443
2006
Sorensen, S.S.Tsujimori, T., Sisson, V.B., Liou, J.G., Harow, G.E., Sorensen, S.S.Very low temperature record of the subduction process: a review of worldwide lawsonite eclogites.Lithos, In press available,Canada, British Columbia, Guatemala, Australia, NorwaySubduction - cold, UHP metamorphism
DS200712-0058
2007
Sorensen, S.S.Beane, R.J., Sorensen, S.S.Protolith signatures and element mobility of the Maksyutov Complex subducted slab, Southern Ural Mountains, Russia.International Geology Review, Vol. 49, 1, pp. 52-72.Russia, UralsSubduction
DS200712-0192
2007
Sorensen, S.S.Cloos, M., Carlson, W.D., Gilbert, M.C., Liou, J.G., Sorensen, S.S.Convergent margin terranes and associated regions: a tribute to W.G. Ernst.Geological Society of America, Special Publication 419, 273p. $ 70.00GlobalConference book - geotectonics
DS201212-0294
2012
Sorensen, S.S.Henning, O.,Sorensen, S.S., Hakin, S., Pedersen, B.oC., Christiansen, Z.I.Non destructive identification of micrometer scale minerals and their position within a bulk sample.Canadian Mineralogist, Vol. 50, 2, pp. 501-509.TechnologyMicrotomography
DS201212-0549
2012
Sorensen, S.S.Penniston-Dorland, S., Walker, R.J., Pitcher, L., Sorensen, S.S.Mantle crust interactions in a paleosubduction zone: evidence from highly siderophile element systematics of eclogite and related rocks.Earth and Planetary Science Letters, Vol. 319-320, pp. 295-306.MantleSubduction
DS201507-0315
2015
Sorensen, SS.Harlow, G.E., Tsujimori, T., Sorensen, SS.Jadeites and plate tectonics.Annual Review of Earth and Planetary Sciences, Vol. 43, pp. 105-138.MantleJadeites
DS1986-0774
1986
Sorenson, H.Sorenson, H.The alkaline rocks- a reviewFortsch. Mineral, Vol. 64, No. 1, pp. 63-86GlobalAlkaline rocks
DS1992-1456
1992
Sorenson, H.Sorenson, H.Agpatic nepheline syenites - a potential source of rare elementsApplied Geochemistry, Vol.7, No. 5, September pp. 417-428GlobalNepheline syenites, Rare earths
DS1991-0568
1991
Sorenson, S.S.Giarmita, M.J., Sorenson, S.S.Fluids attending moderate depths of subduction: evidence from fluid inclusions in Type-C eclogites from high grade rocksGeological Society of America Annual Meeting Abstract Volume, Vol. 23, No. 5, San Diego, p. A 447GlobalEclogites, Subduction
DS201607-1300
2016
Sorenson, S.S.Harlow, G.E., Tsujimori, T., Sorenson, S.S.Jadeites and plate tectonics.Annual Review of Earth and Planetary Sciences, Vol. 43, pp. 105-138.MantleJadeites

Abstract: Jadeitite is a relatively rare, very tough rock composed predominantly of jadeite and typically found associated with tectonic blocks of high-pressure/low-temperature metabasaltic rocks (e.g., eclogite, blueschist) in exhumed serpentinite-matrix mélanges. Studies over the past ?20 years have interpreted jadeitite either as the direct hydrous fluid precipitate from subduction channel dewatering into the overlying mantle wedge or as the metasomatic replacement by such fluids of oceanic plagiogranite, graywacke, or metabasite along the channel margin. Thus, jadeitites directly sample and record fluid transport in the subduction factory and provide a window into this geochemical process that is critical to a major process in the Earth system. They record the remarkable transport of large ion lithophile elements, such as Li, Ba, Sr, and Pb, as well as elements generally considered more refractory, such as U, Th, Zr, and Hf. Jadeitite is also the precious form of jade, utilized since antiquity in the form of tools, adornments, and symbols of prestige.
DS2001-1106
2001
Sorentino, C.Sorentino, C.Formal mineral asset valuation methods: DCF/NPV and option theory methodsValmin 01, Mineral Asset Valuation Oct. 25-6th., pp.160-70.AustraliaEconomics - costs, Mineral reserves, resources, valuation, exploration
DS1992-0252
1992
Sorlien, C.Chorowicz, J., Sorlien, C.Obique extensional tectonics in the Malawi Rift, AfricaGeological Society of America (GSA) Abstract Volume, Vol. 104, No. 8, August pp. 1015-1023East AfricaTectonics, Malawi Rift
DS1990-0392
1990
Sornette, A.Davy, Ph., Sornette, A., Sornette, D.Some consequences of a proposed fractal nature of continental faultingNature, Vol. 348, No. November 1, pp. 56-58India, AsiaTectonics, Faulting -continental
DS1990-0392
1990
Sornette, D.Davy, Ph., Sornette, A., Sornette, D.Some consequences of a proposed fractal nature of continental faultingNature, Vol. 348, No. November 1, pp. 56-58India, AsiaTectonics, Faulting -continental
DS1993-1512
1993
Sorokhtin, N.O.Sorokhtin, O.G., Mitrofanov, F.P., Sorokhtin, N.O.Origin of diamonds and the diamond potential of the Kola Peninsula.Advertised to be published.Russian Academy of Sciences .. new series of English language books Fax 7, 160p.$130.00 United States 7 Kolpachny Per. Block 3, 101933 MoscowRussia, Kola PeninsulaDiamondiferous rocks, Tectonics
DS1993-1512
1993
Sorokhtin, O.G.Sorokhtin, O.G., Mitrofanov, F.P., Sorokhtin, N.O.Origin of diamonds and the diamond potential of the Kola Peninsula.Advertised to be published.Russian Academy of Sciences .. new series of English language books Fax 7, 160p.$130.00 United States 7 Kolpachny Per. Block 3, 101933 MoscowRussia, Kola PeninsulaDiamondiferous rocks, Tectonics
DS2000-0919
2000
Sorokhtina, N.V.Sorokhtina, N.V., Voloshin, A.V., Pakhomovsky, Y.A.Hemimorphite from carbonatites of the Kola Peninsula. IN RUSSIANProceedings Russ. Min. Soc. *RUSS, Vol. 129, No. 2, pp.80-84.Russia, Kola PeninsulaCarbonatite
DS2000-0942
2000
Sorokhtina, N.V.Subbotin, V.V., Volshin, A.V., Sorokhtina, N.V.New mineral phases of niobium in carbonatites of the Kola alkaline province,Russia.Igc 30th. Brasil, Aug. abstract only 1p.Russia, Kola PeninsulaCarbonatite
DS201112-0636
2011
Sorokhtina, N.V.Malitch, K.N., Karpisky, A.P., Sorokhtina, N.V., Goncharov, M.M.Carbonatite of the Guli massif as a possible source of gold: evidence from zirconolite inclusions in Au rich nuggets.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.147-150.Russia, SiberiaGuli
DS201112-0637
2011
Sorokhtina, N.V.Malitch, K.N., Karpisky, A.P., Sorokhtina, N.V., Goncharov, M.M.Carbonatite of the Guli massif as a possible source of gold: evidence from zirconolite inclusions in Au rich nuggets.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.147-150.Russia, SiberiaGuli
DS201112-0638
2011
Sorokhtina, N.V.Malitch, K.N., Sorokhtina, N.V., Goncharov, N.N., Goncharov, M.M.Carbonatite of the Guli Massif as a possible source of gold: evidence from zirconolite inclusions in au-rich nuggets.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterRussia, SiberiaCarbonatite
DS201112-0987
2011
Sorokhtina, N.V.Sorokhtina, N.V., Asavin, A.M., Konomkova, N.N., Senin, V.Composition of K bearing sulfide associations in carbonatites of the Guli massif of the Polar Siberia.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.144-146.Russia, SiberiaGuli
DS201112-0988
2011
Sorokhtina, N.V.Sorokhtina, N.V., Asavin, A.M., Konomkova, N.N., Senin, V.Composition of K bearing sulfide associations in carbonatites of the Guli massif of the Polar Siberia.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.144-146.Russia, SiberiaGuli
DS201112-0989
2011
Sorokhtina, N.V.Sorokhtina, N.V., Asavin, A.M., Kononkova, N.N.Composition of K bearing sulfide associations in carbonatites of the Guli Massif of the Polar Siberia.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterRussia, SiberiaCarbonatite
DS201312-0493
2013
Sorokhtina, N.V.Kogarko, L.N., Sorokhtina, N.V., Kononkova, N.N., Klimovich, I.V.Uranium and thorium in carbonatitic minerals from the Guli Massif, Polar Siberia.Geochemistry International, Vol. 51, 10, pp. 767-776.RussiaCarbonatite
DS201412-0078
2014
Sorokhtina, N.V.Buikin, A.I., Verchovsky, A.B., Sorokhtina, N.V., Kogarko, L.N.Composition and sources of volatiles and noble gases in fluid inclusions in pyroxenites and carbonatites of the Seblyar Massif, Kola Peninsula.Petrology, Vol. 22, 5, p. 507-520.Russia, Kola PeninsulaAlkalic
DS201801-0067
2017
Sorokhtina, N.V.Sorokhtina, N.V., Belyatsky, B.V., Kononkova, N.N., Rodionov, N.V., Lepkhina, E.N., Antonov, A.V., Sergeev, S.A.Pyrochlore group minerals from Paleozoic carbonatite massifs of the Kola Peninsula: composition and evolution.Carbonatite-alkaline rocks and associated mineral deposits , Dec. 8-11, abstract p. 20-21.Russia, Kola Peninsulacarbonatites

Abstract: Chemical composition and evolution of pyrochlore-group minerals (Nb?Ta?Ti) from the early phoscorites and calcite carbonatites, and late rare-earth dolomite carbonatites from Seblyavr and Vuorijarvi Paleozoic massifs have been studied. There are two trends in pyrochlore composition evolution: the change of U, Ti, and Ta enriched varieties by calcium high-Nb, and the change of early calcium varieties by barium-strontium pyrochlores. The substitutions are described by the typical reactions: 2Ti4+ + U4+ ? 2Nb5+ + Ca2+; Ta5+ ? Nb5+; U4+ + v (vacancy) ? 2Ca2+. The Ca ranges in pyrochlores are explained by isomorphic occupation of the cation position A with Ba, Sr, and REE, the total concentration of which increases as the carbonatite melt evolved and reaches a maximum in rare-earth dolomite carbonatites. The formation of barium pyrochlore is mainly due to successive crystallization from the Ba and Sr enriched melt (oscillatory zoning crystals), or with the secondary replacement of grain margins of the calcium pyrochlore, as an additional mechanism of formation. High enrichments in LREE2O3 (up to 6 wt.%) are identified. The fluorine content in pyrochlore group minerals varies widely. A high concentration (up to 8 wt.%) is found in central and marginal zones of crystals from calcite carbonatites, while it decreases in the pyrochlore from dolomite carbonatites. Fluorine in the crystal lattice has sufficient stability during cation-exchange processes and it is not lost in the case of developing of late carbonatites over the earlier ones. In the late mineral populations the relics enriched by this component are observed. There is a positive correlation of fluorine with sodium. The marginal and fractured zones of pyrochlore crystals from all rock types are represented by phases with a cation deficiency in position A and an increased Si. The evolution of mineral composition depends on the alkaline-ultramafic melt crystallization differentiation, enrichment of the late melts by alkalis and alkaline earth metals at the high fluorine activity. It is determined that the fluorine sharply increases from the early pyroxenites to the carbonatite rocks of the massif. The foscorites and carbonatites of the early stages of crystallization are the most enriched in fluorine, while the late dolomite carbonatites are depleted by this component and enriched in chlorine and water. The fluorine saturation of the early stages of carbonatite melting leads to the formation of fluorapatite and pyrochlore minerals which are the main mineralsconcentrators of fluorine. Pyrochlore group minerals from the Paleozoic carbonatite complexes of the Kola Peninsula are characterized by decreasing Pb, Th and U, and Th/U ratios in the transition from the early foscorites to later calcite carbonatites and hydrothermal dolomite carbonatites. The pyrochlore age varies within the 420-320 m.y. interval (U-Pb SHRIMPII data), while the rocks of the earliest magmatic stages has an individual grain age of 423 ± 15 Ma, but pyrochlore ages for calcite and dolomite carbonatites are younger: 351 ± 8.0 Ma and 324 ± 6.1 Ma, respectively. Such a dispersion of the age data is apparently associated with a disturbed Th/U ratio due to high ability for cation-exchange processes of pyrochlore crystalline matrix including secondary transformations. The research was done within the framework of the scientific program of Russian Academy of Sciences and state contract K41.2014.014 with Sevzapnedra.
DS202001-0041
2019
Sorokhtina, N.V.Sorokhtina, N.V., Kogarko, L.N., Zaitsev, V.A., Kononkova, N.N., Asavin, A.M.Sulfide mineralization in the carbonatites and phoscorites of the Guli Massif, Polar Siberia, and their noble metal potential.Geochemistry International, Vol. 57, 11, pp. 1125-1146.Russia, Siberiacarbonatite

Abstract: We report the first combined investigation (neutron activation, X-ray fluorescence, and electron microprobe analysis) of mineral forms of Au and Ag and noble metal distribution in the sulfide-bearing phoscorites and carbonatites of the Guli alkaline ultrabasic massif (Polar Siberia) and magnetite and sulfide separates from these rocks. The highest noble metal contents were observed in the sulfide separates from the carbonatites: up to 2.93 Pt, 61.6 Au, and 3.61 ppm Ag. Pyrrhotite, djerfisherite, chalcopyrite, and pyrite are the most abundant sulfides and the main hosts for Au and Ag. The latest assemblage of chalcopyrite, Ag-rich djerfisherite, lenaite, sternbergite, and native silver shows significant Ag concentrations. The wide occurrence of K sulfides and presence of multiphase inclusions in pyrrhotite consisting of rasvumite, K?Na–Ca carbonate, carbocernaite, strontianite, galena, chalcopyrite, sternbergite, lenaite, and native silver suggest that the sulfides were formed at high activities of K, Na, Sr, LREE, F, Cl, and S. Chlorine shows high complex-forming capacity to Ag and could be an agent of noble metal transport in the carbonatites. Crystallization of the early djerfisherite–pyrrhotite assemblages of the phoscorites and carbonatites began at a temperature not lower than 500°C and continued up to the formation of late Ag-bearing sulfides at temperatures not higher than 150°C. The carbonatite-series rocks could be enriched in Au and Ag during late low-temperature stages and serve as a source for Au placers.
DS202109-1492
2021
Sorokhtina, N.V.Viladkar, S.G., Sorokhtina, N.V.Evolution of pyrochlore in carbonatites of the Amba Dongar complex, India.Mineralogical Magazine, Vol. 85, 4, pp. 554-567.Indiadeposit - Amba Dongar

Abstract: Pyrochlore-group minerals are common accessory rare-metal bearing minerals in the calcite and ankerite carbonatites of the Amba Dongar complex (India). Pyrochlore from the Amba Dongar carbonatites differs from that in other Indian complexes in Ta, Zr, Ti, rare earth element (REE) and Pb contents, but is similar with respect to Ca, Ba and Sr abundances. The evolution of pyrochlore composition was studied to understand the alteration processes and the formation of late-stage pyrochlores enriched in REE and Pb. The early magmatic pyrochlore are calcio- and niobium-dominant types and were replaced by secondary cation-deficient varieties as a consequence of the action of hydrothermal fluids and supergene weathering. These processes produce changes mainly at the A site, rarely at the B site, and the original F is replaced by OH- groups. Calcium and Na can be extracted from the structure at the alteration stage and charge balance is achieved by the introduction of REE, Th, U, Ba or Sr. At the latest supergene stages, marginal and fractured zones of pyrochlore grains are altered to Pb-rich, Si-rich and cation-deficient hydrated varieties. The magmatic pyrochlore was crystallised in a highly alkaline environment at a high activity of Ca and at temperatures near 600°C, the alteration of pyrochlore began in a hydrothermal environment at temperatures below 350°C. The major compositional changes that are associated with the alteration are summarised by the following reactions: Ca2+ + Nb5+? REE3+ + Ti4+; Nb5+ + Fe3+ ? Ti4+ + Zr4+; and 2Nb5+ + Ca2+ ? Ti4+ + Si4+ + U4+.
DS200612-0189
2006
SorokinBuchko, I.V., Salnikova, E.B., Kotov, A.B., Larin, A.M., Velikoslavinskii, Sorokin, Sorokin, YakovlevaPaleoproterozoic gabbro anorthosites of the Selenga Superterrane, southern framing of the Siberian Craton.Doklady Earth Sciences, Vol. 407, 3, pp. 372-375.Russia, SiberiaTectonics
DS200612-0189
2006
SorokinBuchko, I.V., Salnikova, E.B., Kotov, A.B., Larin, A.M., Velikoslavinskii, Sorokin, Sorokin, YakovlevaPaleoproterozoic gabbro anorthosites of the Selenga Superterrane, southern framing of the Siberian Craton.Doklady Earth Sciences, Vol. 407, 3, pp. 372-375.Russia, SiberiaTectonics
DS200812-0151
2008
Sorokin, A.P.Buchko, I.V., Sorokin, A.P., Yakoleva, S.Z., Plotkina, Y.V.Petrology of the Early Mesozoic ultramafic mafic Luchin a massif ( southeastern periphery of the Siberian Craton).Russian Geology and Geophysics, Vol. 49, 8, pp. 570-581.RussiaUltramafic rocks
DS201502-0097
2015
Sorokin, K.Sharapov, V., Sorokin, K., Perepechko, Y.Dynamics of mantle rock metasomatic transformation in permeable lithospheric zones beneath Siberian craton.Economic Geology Research Institute 2015, Vol. 17,, # 2153, 1p. AbstractRussiaGeothermometry
DS200412-1826
2004
Sorokin, L.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
DS200512-0987
2004
Sorokin, L.M.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
DS1988-0771
1988
Sorokin, M.Yu.Yegorov, I.V., Sorokin, M.Yu., Yaskevich, V.G.The experience of structural geomorphological studies in predicting kimberlite spatial distribution.(Russian)Geomorfologiya, (Russian), Vol. 1988, No. 3, pp. 24-28RussiaPetrology, Geomorphology
DS201901-0008
2018
Sorokin, P.B.Blank, V.D., Churkin, V.D., Kulnitsky, B.A., Perezhogin, I.A., Kirichenko, A.N., Erohin, S.V., Sorokin, P.B., Popov, M.Y.Pressure induced transformation of graphite and diamond to onions.Crystals MDPI, Vol. 8, 2, 8p. Doi.org/10.3390/cryst8020068Russiacarbon nanotubes

Abstract: In this study, we present a number of experiments on the transformation of graphite, diamond, and multiwalled carbon nanotubes under high pressure conditions. The analysis of our results testifies to the instability of diamond in the 55-115 GPa pressure range, at which onion-like structures are formed. The formation of interlayer sp3-bonds in carbon nanostructures with a decrease in their volume has been studied theoretically. It has been found that depending on the structure, the bonds between the layers can be preserved or broken during unloading.
DS1988-0263
1988
Sorokina, V.D.Gorokhov, N.P., Tiunov, A.A., Kistanova, T.I., Sorokina, V.D.Use of phosphates in the flotation of pyrochlorefromcarbonatitepipes.(Russian)Tsvetn. Met. (Moscow), (Russian), No. 12, pp. 87-88RussiaCarbonatite, Mineral processing applic
DS1995-0862
1995
Sorowka, A.Jacob, D.E., Jagoutz, E., Sobolev, N.V., Sorowka, A.Isotopic analysis ( Samarium/neodymium, Rubidium-Strontium and Uranium/lead) of single subcalcic garnet grains from Yakutian kimberlites.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 257-259.Russia, YakutiaGeochemistry, isotopes, Geochronology -garnets
DS1950-0239
1955
Sorum, H.Sorum, H.Contribution to the Mineralogy of the Sove DepositKong. Norsk Vidensk. Selsk. Skr., Vol. 28, PP. 112-127.Norway, ScandinaviaMineralogy
DS1975-1027
1979
Soshkina, L.T.Garanin, V.K., Kudryavtseva, G.P., Soshkina, L.T.Possible Applications of Thermomagnetic Analysis in Kimberlite Body Prospecting.Vses. Mineral O-vo Zap., No. 5, PP. 621-630.RussiaKimberlite, Geophysics
DS1983-0240
1983
Soshkina, L.T.Garanin, V.K., Kudriavtseva, G.P., Soshkina, L.T.Genesis of Ilmenite from KimberlitesDoklady Academy of Science USSR, Earth Science Section., Vol. 172, No. 1-6, MARCH PP. 102-106.RussiaGenesis, Petrography, Mineralogy
DS1984-0595
1984
Soshkina.Posukhova, T.V., Bocharova, G.I., Kudryavtseva, G.P., Soshkina.Features of Morphology and Internal Structure of Ilmenite from kimberlites of the Malo Botuobinskii Region of Yakutia.Moscow University Geol. Bulletin., Vol. 39, No. 6, PP. 36-44.Russia, YakutiaMicroscopy, Mineralogy, Amaka Pipe, Taezhnyi
DS1930-0282
1938
Sosman, R.H.Sosman, R.H.Evidence on the Intrusion Temperature of PeridotiteAmerican Journal of Science, Vol. 35, PP. 353-359.Appalachia, PennsylvaniaRelated Rocks
DS201912-2805
2019
Sossi, P.McCoy-West, A.J., Chowdhury, P., Burton, K.W., Sossi, P., Nowell, G,M., Fitton, J.G., Kerr, A.C., Cawood, P.A., Williams, H.M.Extensive crustal extraction in Earth's early history inferred from molybdenum isotopes.Nature Geoscience, Vol. 12, pp. 946-951.Mantlepicrites

Abstract: Estimates of the volume of the earliest crust based on zircon ages and radiogenic isotopes remain equivocal. Stable isotope systems, such as molybdenum, have the potential to provide further constraints but remain underused due to the lack of complementarity between mantle and crustal reservoirs. Here we present molybdenum isotope data for Archaean komatiites and Phanerozoic komatiites and picrites and demonstrate that their mantle sources all possess subchondritic signatures complementary to the superchondritic continental crust. These results confirm that the present-day degree of mantle depletion was achieved by 3.5 billion years ago and that Earth has been in a steady state with respect to molybdenum recycling. Mass balance modelling shows that this early mantle depletion requires the extraction of a far greater volume of mafic-dominated protocrust than previously thought, more than twice the volume of the continental crust today, implying rapid crustal growth and destruction in the first billion years of Earth’s history.
DS201412-0616
2014
Sossi, P.A.Nebel, O., Campbell, I.H., Sossi, P.A.Hafnium and iron isotopes in early Archean komatiites record a plume driven convection cycle in the Hadean Earth.Earth and Planetary Science Letters, Vol. 397, pp. 111-120.MantleConvection
DS1995-1805
1995
Sosso, F.Sosso, F.Some observations on a gem quality synthetic yellow diamond produced in the region of Vladimir (Russia).Journal of Gemology, Vol. 24, No. 5, Jan. pp. 363-368.RussiaDiamond morphology, Diamond synthesis
DS1995-0464
1995
Sotin, C.Dupeyrat, L., Sotin, C., Parmentier, E.M.Thermal and chemical convection in planetary mantlesJournal of Geophy. Res. Sol., Vol. 100, No. 1, Jan. 10, pp. 497-520.MantleGeochemistry, Convection
DS2002-0414
2002
Sotin, C.Eberle, M.A., Grasset, O., Sotin, C.A numerical study of the interaction between the mantle wedge, subducting slab and overriding plate.Physics of the Earth and Planetary Interiors, Vol. 134, 3-4, Dec. 22, pp. 191-202.MantleSubduction, Tomography
DS201412-0953
2014
Sotnikov, I.A.Vladykin, N.V., Sotnikov, I.A., Kotov, A.B., Yarmolyuk, V.V., Salnikova, E.B., Yakovleva, S.Z.Structure, age and ore potential of the Burpala rare-metal alkaline Massif, northern Baikal region.Geology of Ore Deposits, Vol. 56, 4, pp. 239-256.RussiaAlkalic
DS201502-0106
2015
Sotnikova, I.Sotnikova, I., Vladykin, N.Genesis of rare metal pegmatites and alkaline fluorite rocks of Burpala Massif, northern Baikal folded zone.Economic Geology Research Institute 2015, Vol. 17,, # 3020, 1p. AbstractRussiaCarbonatite
DS201612-2344
2016
Sotnikova, I.A.Vladykin, N.V., Sotnikova, I.A.Petrology, geochemistry and source characteristics of the Burpala alkaline massif, north Baikal.Geoscience Frontiers, in press availableRussiaAlkalic

Abstract: The Burpala alkaline massif contains rocks with more than 50 minerals rich in Zr, Nb, Ti, Th, Be and rare earth elements (REE). The rocks vary in composition from shonkinite, melanocratic syenite, nepheline and alkali syenites to alaskite and alkali granite and contain up to 10% LILE and HSFE, 3.6% of REE and varying amounts of other trace elements (4% Zr, 0.5% Y, 0.5% Nb, 0.5% Th and 0.1% U). Geological and geochemical data suggest that all the rocks in the Burpala massif were derived from alkaline magma enriched in rare earth elements. The extreme products of magma fractionation are REE rich pegmatites, apatite-fluorite bearing rocks and carbonatites. The Sr and Nd isotope data suggest that the source of primary melt is enriched mantle (EM-II). We correlate the massif to mantle plume impact on the active margin of the Siberian continent.
DS202204-0542
2022
Sotnikova, I.A.Vladykin, N.V., Ashchepkov, I.V., Sotnikova, I.A., Medvedev, N.S.Lamproites of Kayla pipe and their mantle xenocrysts, SE Aldan shield, Russia: geochemistry and petrology.Jounral of Earth System Science, Vol. 131 81 doi.org/10/1007/s12040-022-01814-3 19p. PdfRussiadeposit - Kayla

Abstract: Origin of abundant alkaline and related lamproite massifs and dykes in Aldan shield have no explanation and the geochemistry of rocks and their xenocrysts is used for the explanation. Bulk-rock geochemistry, mineral chemistry data of the Kayla lamproites of Russia and mineral chemical data (trace and rare elements) of the mantle xenocrysts found in these lamproites was studied using ICP MS and electron microprobe analyses (EPMA). The trace element spectrum of Kayla tuffs and breccias show the similarity with the olivine lamproites and belong to the orogenic type according to Th-U-Nb systematics. Primitive mantle normalized trace element (TRE) spider diagrams show right-leaning patterns with the peaks in large ion lithophile elements Sr, Pb, U, and troughs in Ta, Nb suggesting melting of original peridotites mixed with the ancient EMI (according to Nd, Sr isotopes) source probably belonging to eclogites or lower crust. The age of the emplacement is 132-134 Ma, similar to the Chompolo lamprophyres and many other alkaline Aldan complexes. Thermo-barometric estimation from Cr-diopsides and chromites xenocrysts suggest the origin from the spinel-garnet transition in the lithospheric mantle region. The P-T estimates derived from low-Cr-clinopyroxene xenocrysts, and related to lamproites show a high heat flow of 90 mW/m2 due to interaction with the plume-related magma. The Cr-diopsides and chromites give 45 mW/m2 geotherm similar to regional heat flow. The chondrite normalized rare earth element (REE) pattern for chrome-diopsides is steeper, compared to the low-chrome varieties. Primitive mantle normalized spidergram of Cr-diopsides displays peaks for Sr, U, and Th, and deep troughs of Nd, Nb, Ta. REE. The trace element spider diagrams of both types of xenocrysts show that they were equilibrated with the lamproitic melts and reconstructed parental melts of low-Cr-clinopyroxene coincides with the lamproite spectrums.
DS1993-1513
1993
Soto, J.I.Soto, J.I.PTMAFIC: software for thermobarometry and activity calculations with mafic and ultramafic assemblagesAmerican Mineralogist, Vol. 78, No. 7-8, July-August, pp. 840-843GlobalComputer, Program: PTMAFIC.
DS1993-1514
1993
Soto, J.I.Soto, J.I.PTMAFIC: sodtware for thermobarometry and activity calculations with mafic and ultramafic assemblages.American Mineralogist, Vol. 78, No. 7-8, July-August pp. 840-844.GlobalComputer Program, PTMAFIC.
DS202012-2209
2020
Sottili, G.Buono, G., Fanara, S., Macedonio, G., Palladino, D.M., Petrosino, P., Sottili, G., Pappalardo, L.Dynamics of degassing in evolved alkaline magmas: petrological, experimental and theoretical insights.Earth-Science Reviews, Vol. 211, 103402, 23p. PdfMantlealkaline

Abstract: In the last few decades, advanced monitoring networks have been extended to the main active volcanoes, providing warnings for variations in volcano dynamics. However, one of the main tasks of modern volcanology is the correct interpretation of surface-monitored signals in terms of magma transfer through the Earth's crust. In this frame, it is crucial to investigate decompression-induced magma degassing as it controls magma ascent towards the surface and, in case of eruption, the eruptive style and the atmospheric dispersal of tephra and gases. Understanding the degassing behaviour is particularly intriguing in the case of poorly explored evolved alkaline magmas. In fact, these melts frequently feed hazardous, highly explosive volcanoes (e.g., Campi Flegrei, Somma-Vesuvius, Colli Albani, Tambora, Azores and Canary Islands), despite their low viscosity that usually promotes effusive and/or weakly explosive eruptions. Decompression experiments, together with numerical models, are powerful tools to examine magma degassing behaviour and constrain field observations from natural eruptive products and monitoring signals. These approaches have been recently applied to evolved alkaline melts, yet numerous open questions remain. To cast new light on the degassing dynamics of evolved alkaline magmas, in this study we present new results from decompression experiments, as well as a critical review of previous experimental works. We achieved a comprehensive dataset of key petrological parameters (i.e., 3D textural data for bubbles and microlites using X-ray computed microtomography, glass volatile contents and nanolite occurrence) from experimental samples obtained through high temperature-high pressure isothermal decompression experiments on trachytic alkaline melts at super-liquidus temperature. We explored systematically a range of final pressures (from 200 to 25 MPa), decompression rates (from 0.01 to 1 MPa s?1), and volatile (H2O and CO2) contents. On these grounds, we integrated coherently literature data from decompression experiments on evolved alkaline (trachytic and phonolitic) melts under various conditions, with the aim to fully constrain the degassing mechanisms and timescales in these magmas. Finally, we simulated numerically the experimental conditions to evaluate strengths and weaknesses in decrypting degassing behaviour from field observations. Our results highlight that bubble formation in evolved alkaline melts is primarily controlled by the initial volatile (H2O and CO2) content during magma storage. In these melts, bubble nucleation needs low supersaturation pressures (? 50-112 MPa for homogeneous nucleation, ? 13-25 MPa for heterogeneous nucleation), resulting in high bubble number density (~ 1012-1016 m?3), efficient volatile exsolution and thus in severe rheological changes. Moreover, the bubble number density is amplified in CO2-rich melts (mole fraction XCO2 ? 0.5), in which continuous bubble nucleation predominates on growth. These conditions typically lead to highly explosive eruptions. However, moving towards slower decompression rates (? 10?1 MPa s?1) and H2O-rich melts, permeable outgassing and inertial fragmentation occur, promoting weakly explosive eruptions. Finally, our findings suggest that the exhaustion of CO2 at deep levels, and the consequent transition to a H2O-dominated degassing, can crucially enhance magma vesiculation and ascent. In a hazard perspective, these constraints allow to postulate that time-depth variations of unrest signals could be significantly weaker/shorter (e.g., minor gas emissions and short-term seismicity) during major eruptions than in small-scale events.
DS202109-1455
2021
Sottili, G.Buono, G., Fanara, S., Macedonio, G., Palladino, D.M., Petrosino, P., Sottili, G., Pappalardo, L.Dynamics of degassing in evolved alkaline magmas: petrological, experimental and theoretical insights.Earth Science Reviews , Vol. 211, 103402, 23p. PdfMantlegeodynamics

Abstract: In the last few decades, advanced monitoring networks have been extended to the main active volcanoes, providing warnings for variations in volcano dynamics. However, one of the main tasks of modern volcanology is the correct interpretation of surface-monitored signals in terms of magma transfer through the Earth's crust. In this frame, it is crucial to investigate decompression-induced magma degassing as it controls magma ascent towards the surface and, in case of eruption, the eruptive style and the atmospheric dispersal of tephra and gases. Understanding the degassing behaviour is particularly intriguing in the case of poorly explored evolved alkaline magmas. In fact, these melts frequently feed hazardous, highly explosive volcanoes (e.g., Campi Flegrei, Somma-Vesuvius, Colli Albani, Tambora, Azores and Canary Islands), despite their low viscosity that usually promotes effusive and/or weakly explosive eruptions. Decompression experiments, together with numerical models, are powerful tools to examine magma degassing behaviour and constrain field observations from natural eruptive products and monitoring signals. These approaches have been recently applied to evolved alkaline melts, yet numerous open questions remain. To cast new light on the degassing dynamics of evolved alkaline magmas, in this study we present new results from decompression experiments, as well as a critical review of previous experimental works. We achieved a comprehensive dataset of key petrological parameters (i.e., 3D textural data for bubbles and microlites using X-ray computed microtomography, glass volatile contents and nanolite occurrence) from experimental samples obtained through high temperature-high pressure isothermal decompression experiments on trachytic alkaline melts at super-liquidus temperature. We explored systematically a range of final pressures (from 200 to 25 MPa), decompression rates (from 0.01 to 1 MPa s?1), and volatile (H2O and CO2) contents. On these grounds, we integrated coherently literature data from decompression experiments on evolved alkaline (trachytic and phonolitic) melts under various conditions, with the aim to fully constrain the degassing mechanisms and timescales in these magmas. Finally, we simulated numerically the experimental conditions to evaluate strengths and weaknesses in decrypting degassing behaviour from field observations. Our results highlight that bubble formation in evolved alkaline melts is primarily controlled by the initial volatile (H2O and CO2) content during magma storage. In these melts, bubble nucleation needs low supersaturation pressures (? 50-112 MPa for homogeneous nucleation, ? 13-25 MPa for heterogeneous nucleation), resulting in high bubble number density (~ 1012-1016 m?3), efficient volatile exsolution and thus in severe rheological changes. Moreover, the bubble number density is amplified in CO2-rich melts (mole fraction XCO2 ? 0.5), in which continuous bubble nucleation predominates on growth. These conditions typically lead to highly explosive eruptions. However, moving towards slower decompression rates (? 10?1 MPa s?1) and H2O-rich melts, permeable outgassing and inertial fragmentation occur, promoting weakly explosive eruptions. Finally, our findings suggest that the exhaustion of CO2 at deep levels, and the consequent transition to a H2O-dominated degassing, can crucially enhance magma vesiculation and ascent. In a hazard perspective, these constraints allow to postulate that time-depth variations of unrest signals could be significantly weaker/shorter (e.g., minor gas emissions and short-term seismicity) during major eruptions than in small-scale events.
DS2001-0981
2001
SoubiesRocha, E.B., Nasraqui, M., Soubies, BilalGeochemical evolution of pyrochlore during supergene alteration of CatalaoII ore deposits.Journal of South African Earth Sciences, Vol. 32, No. 1, p. A 29.(abs)BrazilCarbonatite, Catalao II
DS1989-1435
1989
Soubies, F.Soubies, F., Melfi, A.J., Aparecida Sardela, I.Zirconium mobility during lateritic weathering of alkaline rocks of Pocosde CaldasXiii International Geochemical Exploration Symposium, Rio 89 Brazilian Geochemical, p. 206. Abstract very briefBrazilAlkaline rocks, Geochemistry
DS1990-1397
1990
Soubies, F.Soubies, F., Melfi, A.J., Autefage, F.Geochemical behaviour of rare earth elements in alterites of phosphate and titanium ore deposits in Tapira (Minas Gerais, Brasil):importance ofphosphatesChemical Geology ( Geochem. of the Earth's surface and of min. formation, 2nd., Vol. 84, No. 1-4, July 5, pp. 377. AbstractBrazilAlkaline rocks, rare earth elements (REE) -phosphates
DS1997-1085
1997
Soubies, F.Sondag, F., Soubies, F., Melfi, A.Hydrogeochemistry in soils and sediments in the area of the Lagoa Campestre Lake ( Salitre): chemical balancesApplied Geochemistry, Vol. 12, No. 2, March, 1, pp. 155-162Brazil, Minas GeraisRare earth elements, Laterites
DS202008-1385
2020
Souders, A.K.Drenth, B.J., Souders, A.K., Schulz, K.J., Feinberg, J.M., Anderson, R.R., Chandler, V.W., Cannon, W.L., Clark, R.J.Evidence for a concealed Midcontinent Rift related northeast Iowa intrusive complex.Precambrian Research, in press available, 43p. PdfUnited States, Iowageophysics - seismics

Abstract: Large amplitude aeromagnetic and gravity anomalies over a ~9500 km2 area of northeast Iowa and southeast Minnesota have been interpreted to reflect the northeast Iowa intrusive complex (NEIIC), a buried intrusive igneous complex composed of mafic/ultramafic rocks in the Yavapai Province (1.8-1.7 Ga). Hundreds of meters of Paleozoic sedimentary cover and a paucity of basement drilling have prevented detailed studies of the NEIIC. Long considered, but not proven, to be related to the ~1.1 Ga Midcontinent Rift System (MRS), the NEIIC is comparable in areal extent to the richly mineralized Duluth Complex and is similarly located near the margin of the MRS. New geochronological and geophysical data together support an MRS affinity for the NEIIC. A dike swarm imaged in aeromagnetic data is cut by intrusions of the NEIIC, and a new apatite U-Pb date of ~1170 Ma on one of the dikes thus represents a maximum age for the NEIIC. A minimum age constraint is suggested by (1) large-volume magmatism associated with the MRS that was the last such event to affect the region; and (2) the presence of reversely magnetized dikes, similar in character to MRS-related dikes elsewhere, that cut several intrusions of the NEIIC. The NEIIC is largely characterized by the presence of multiple zoned intrusions, many of which contain large volumes of mafic-ultramafic rocks and have strong geophysical similarities to alkaline intrusive complexes elsewhere, including the MRS-related Coldwell Complex of Ontario. The largest of the zoned intrusions are ~40 km in diameter and are interpreted to have thicknesses of many kilometers. Suspected faults, alignments of intrusions, and intrusive margins tend to be aligned along northwest and northeast trends that match the trends of the Belle Plaine fault zone and Fayette structural zone, both previously interpreted as pre-MRS, possibly lithospheric-scale discontinuities that may have controlled NEIIC emplacement. These interpretations collectively imply notable potential for the NEIIC to host several different types of undiscovered base metal and critical mineral deposits.
DS202010-1839
2020
Souders, A.K.Drenth, N.J., Souders, A.K., Schulz, K.J., Feinberg, J.M., Anderson, R.R., Chandler, V.W., Cannon, W.F., Clark, R.J.Evidence for a concealed Midcontinent Rift related northeast Iowa intrusive complex.Precambrian Research, Vol. 347, 105845, 23p. PdfUnited States, Iowageochronology, geophysics - gravity

Abstract: Large amplitude aeromagnetic and gravity anomalies over a ~9500 km2 area of northeast Iowa and southeast Minnesota have been interpreted to reflect the northeast Iowa intrusive complex (NEIIC), a buried intrusive igneous complex composed of mafic/ultramafic rocks in the Yavapai Province (1.8-1.7 Ga). Hundreds of meters of Paleozoic sedimentary cover and a paucity of basement drilling have prevented detailed studies of the NEIIC. Long considered, but not proven, to be related to the ~1.1 Ga Midcontinent Rift System (MRS), the NEIIC is comparable in areal extent to the richly mineralized Duluth Complex and is similarly located near the margin of the MRS. New geochronological and geophysical data together support an MRS affinity for the NEIIC. A dike swarm imaged in aeromagnetic data is cut by intrusions of the NEIIC, and a new apatite U-Pb date of ~1170 Ma on one of the dikes thus represents a maximum age for the NEIIC. A minimum age constraint is suggested by (1) large-volume magmatism associated with the MRS that was the last such event to affect the region; and (2) the presence of reversely magnetized dikes, similar in character to MRS-related dikes elsewhere, that cut several intrusions of the NEIIC. The NEIIC is largely characterized by the presence of multiple zoned intrusions, many of which contain large volumes of mafic-ultramafic rocks and have strong geophysical similarities to alkaline intrusive complexes elsewhere, including the MRS-related Coldwell Complex of Ontario. The largest of the zoned intrusions are ~40 km in diameter and are interpreted to have thicknesses of many kilometers. Suspected faults, alignments of intrusions, and intrusive margins tend to be aligned along northwest and northeast trends that match the trends of the Belle Plaine fault zone and Fayette structural zone, both previously interpreted as pre-MRS, possibly lithospheric-scale discontinuities that may have controlled NEIIC emplacement. These interpretations collectively imply notable potential for the NEIIC to host several different types of undiscovered base metal and critical mineral deposits.
DS1950-0427
1958
Soufoulis, J.Soufoulis, J.Report on the Reconnaissance of the Diamondiferous Country In the Vicinity of Nullagine, Pilbara Gold field Western Australia.Western Australia Geological Survey, Section B., No. 109, PP. 91-94.Australia, Western AustraliaKimberlite, Diamond
DS1988-0656
1988
Sougy, J.Sougy, J., Rodgers, J.The West African connection: evolution of the central Atlantic ocean And its continental marginsProceedings of the Penrose Conference held in France Jan 17-22, 1984, pp. 311-515West AfricaBlank
DS1970-0900
1974
Sougy, J.M.A.Dillon, W.P., Sougy, J.M.A.Geology of West Africa and Canary and Cape Verde IslandsIn: The Ocean Basins And Margins, Volume 2, The North Atlant, PP. 315-390.West Africa, Guinea, Sierra Leone, Senegal, Ivory Coast, GhanaTectonics, Structure
DS201703-0408
2017
Souhassou, M.Ikenne, M., Souhassou, M., Arai, S., Soulaimani, A.A historical overview of Moroccan magmatic events along the northwest edge of the West African craton.Journal of African Earth Sciences, Vol. 127, pp. 3-15.Africa, MoroccoCraton - magmatism

Abstract: Located along the northwestern edge of the West African Craton, Morocco exhibits a wide variety of magmatic events from Archean to Quaternary. The oldest magmatic rocks belong to the Archean Reguibat Shield outcrops in the Moroccan Sahara. Paleoproterozoic magmatism, known as the Anti-Atlas granitoids, is related to the Eburnean orogeny and initial cratonization of the WAC. Mesoproterozoic magmatism is represented by a small number of mafic dykes known henceforth as the Taghdout mafic volcanism. Massive Neoproterozoic magmatic activity, related to the Pan-African cycle, consists of rift-related Tonian magmatism associated with the Rodinia breakup, an Early Cryogenian convergent margin event (760-700 Ma), syn-collisional Bou-Azzer magmatism (680-640 Ma), followed by widespread Ediacaran magmatism (620-555 Ma). Each magmatic episode corresponded to a different geodynamic environment and produced different types of magma. Phanerozoic magmatism began with Early Cambrian basaltic (rift?) volcanism, which persisted during the Middle Cambrian, and into the Early Ordovician. This was succeeded by massive Late Devonian and Carboniferous, pre-Variscan tholeiitic and calc-alkaline (Central Morocco) volcanic flows in basins of the Moroccan Meseta. North of the Atlas Paleozoic Transform Zone, the Late Carboniferous Variscan event was accompanied by the emplacement of 330-300 Ma calc-alkaline granitoids in upper crustal shear zones. Post-Variscan alkaline magmatism was associated with the opening of the Permian basins. Mesozoic magmatism began with the huge volumes of magma emplaced around 200 Ma in the Central Atlantic Magmatic Province (CAMP) which was associated with the fragmentation of Pangea and the subsequent rifting of Central Atlantic. CAMP volcanism occurs in all structural domains of Morocco, from the Anti-Atlas to the External Rif domain with a peak activity around 199 Ma. A second Mesozoic magmatic event is represented by mafic lava flows and gabbroic intrusions in the Internal Maghrebian flysch nappes as well as in the external Mesorif. This event consists of Middle-Upper Jurassic MORB tholeiites emplaced during opening of the Alpine Tethys ocean. The Central High Atlas also records Early Cretaceous alpine Tethys magmatism associated with the aborted Atlas rift, or perhaps linked to plume activity on the edge of the WAC. Cenozoic magmatism is associated with Tertiary and Quaternary circum-Mediterranean alkaline provinces, and is characterized by an intermittent activity over 50 Ma from the Anti-Atlas to the Rif Mountain along a SW-NE volcanic lineament which underlines a thinned continental lithosphere.
DS2002-0970
2002
Souhel, A.Lowner, R., Souhel, A., Chafiki, D., Canerot, J., Klitzsch, E.Structural and sedimentologic relations between the high and middle Atlas of Morocco during the Jurassic time.Journal of African Earth Sciences, Vol.34, No.3-4,April-May pp. 287-90.MoroccoTectonics
DS200612-0198
2006
Soulaimani, A.Burkhard, M., Caritag, S., Helg, U., Robert Charrue, C., Soulaimani, A.Tectonics of the Anti-Atlas of Morocco.Comptes Rendus Geoscience, Vol. 338, 1-2, pp. 11-24.Africa, MoroccoTectonics
DS201312-0241
2013
Soulaimani, A.El Bahat, A., Ikenne, M., Soderlund, U., Cousens, B., Youbi, N., Ernst, R., Soulaimani, A., El Janati, M., Hafid, A.U PB baddeleyite ages and geochemistry of dolerite dykes in the Bas Draa In lier of the Anti-Atlas of Morocco: newly identified Ma event in the West African craton.Lithos, Vol. 174, pp. 85-98.Africa, MoroccoGeochronology
DS201312-0511
2013
Soulaimani, A.Kouyate, D., Soderlund, U., Youbi, N., Ernst, R., Hafid, A., Ikeene, M., Soulaimani, A., Betrand, H., El Janati, M., Rkha, C.U Pb baddeleyite and zircon ages of 2040 Ma, 1650 Ma and 885 Ma on dolerites in the West African Craton ( Anti-Atlas inliers) : possible links to break up of Precambrian supercontinents.Lithos, Vol. 174, pp. 71-84.AfricaGeochronology
DS201312-0999
2013
Soulaimani, A.Youbi, N., Kouyate, D., Soderlund, U., Ernst, R.E., Soulaimani, A., Hafid, A., Ikenne, M., El Bahat, A., Betrand, H., Chaham, K.R., Ben Abbou, M., Mortaji, A., El Ghorfi, M., Zouhair, M., El Janati, M.The 1750 Ma magmatic event of the West African Craton ( Anti-Atlas) Morocco.Precambrian Research, Vol. 236, pp. 106-123.Africa, MoroccoDike swarms
DS201703-0408
2017
Soulaimani, A.Ikenne, M., Souhassou, M., Arai, S., Soulaimani, A.A historical overview of Moroccan magmatic events along the northwest edge of the West African craton.Journal of African Earth Sciences, Vol. 127, pp. 3-15.Africa, MoroccoCraton - magmatism

Abstract: Located along the northwestern edge of the West African Craton, Morocco exhibits a wide variety of magmatic events from Archean to Quaternary. The oldest magmatic rocks belong to the Archean Reguibat Shield outcrops in the Moroccan Sahara. Paleoproterozoic magmatism, known as the Anti-Atlas granitoids, is related to the Eburnean orogeny and initial cratonization of the WAC. Mesoproterozoic magmatism is represented by a small number of mafic dykes known henceforth as the Taghdout mafic volcanism. Massive Neoproterozoic magmatic activity, related to the Pan-African cycle, consists of rift-related Tonian magmatism associated with the Rodinia breakup, an Early Cryogenian convergent margin event (760-700 Ma), syn-collisional Bou-Azzer magmatism (680-640 Ma), followed by widespread Ediacaran magmatism (620-555 Ma). Each magmatic episode corresponded to a different geodynamic environment and produced different types of magma. Phanerozoic magmatism began with Early Cambrian basaltic (rift?) volcanism, which persisted during the Middle Cambrian, and into the Early Ordovician. This was succeeded by massive Late Devonian and Carboniferous, pre-Variscan tholeiitic and calc-alkaline (Central Morocco) volcanic flows in basins of the Moroccan Meseta. North of the Atlas Paleozoic Transform Zone, the Late Carboniferous Variscan event was accompanied by the emplacement of 330-300 Ma calc-alkaline granitoids in upper crustal shear zones. Post-Variscan alkaline magmatism was associated with the opening of the Permian basins. Mesozoic magmatism began with the huge volumes of magma emplaced around 200 Ma in the Central Atlantic Magmatic Province (CAMP) which was associated with the fragmentation of Pangea and the subsequent rifting of Central Atlantic. CAMP volcanism occurs in all structural domains of Morocco, from the Anti-Atlas to the External Rif domain with a peak activity around 199 Ma. A second Mesozoic magmatic event is represented by mafic lava flows and gabbroic intrusions in the Internal Maghrebian flysch nappes as well as in the external Mesorif. This event consists of Middle-Upper Jurassic MORB tholeiites emplaced during opening of the Alpine Tethys ocean. The Central High Atlas also records Early Cretaceous alpine Tethys magmatism associated with the aborted Atlas rift, or perhaps linked to plume activity on the edge of the WAC. Cenozoic magmatism is associated with Tertiary and Quaternary circum-Mediterranean alkaline provinces, and is characterized by an intermittent activity over 50 Ma from the Anti-Atlas to the Rif Mountain along a SW-NE volcanic lineament which underlines a thinned continental lithosphere.
DS200612-0199
2006
Soulainmani, A.Burkhard, M., Caritg, S., Helg, U., Robert-Charrue, C., Soulainmani, A.Tectonics of the Anti-Atlas of Morocco.Comptes Rendus Geoscience, Vol. 338, 1-2, pp. 11-24.Africa, MoroccoTectonics
DS1988-0619
1988
SoulasSebrier, M., Lavenu, A., Fornari, SoulasTectonics and uplift in Central Andes from Eocene to presentGeodynamique, Eng., Vol. 3, No. 1-2, pp. 85-106.Peru, Bolivia, ChileTectonics
DS201709-2045
2017
Soumya, G.S.Radhakrishna, T., Soumya, G.S., Satyanarayana, K.V.V.Paleomagnetism of the Cretaceous lamproites from Gondwana basin of the Damodar Valley in India and migration of the Kerguelen plume in the southeast Indian Ocean.Journal of Geodynamics, Vol. 109, pp. 1-9.Indialamproites

Abstract: The paper presents new palaeomagnetic results and reassesses complete set of published palaeomagnetic results on the lamproite intrusions in the Gondwana formations of the Eastern India. Altogether eleven sites register reliable characteristic magnetisations corresponding to the c. 110 Ma emplacement age of the lamproites. A mean ChRM is estimated with D = 331.3°; I = ?62.4° (?95 = 6.2°, k = 55; N = 11). The palaeomagnetic pole of ? = 14.9°: ? = 287.6° (A95 = 8.4°) is established for the lamproites and it averaged the secular variation and confirms to the Geocentric Axial Dipole (GAD). The pole compares remarkably well with the grand mean pole reported for the Rajmahal traps that are attributed to represent location of the Kerguelen mantle plume head. The palaeolatitudes transferred to Rajmahal coordinates (25.05°: 87.84°) are situated ?6° north of the present location of the Kerguelen hotspot location. The interpretations are consistent with earlier suggestions of southward migration of the plume based on palaeomagnetic results of Site 1138 of the ODP Leg 183 and with the predictions of numerical models of global mantle circulation.
DS1989-0237
1989
Souriau, A.Cazenave, A., Souriau, A., Dominh, K.Global coupling of earth surface topography with hotspots, geoid and mantleheterogeneitiesNature, Vol. 340, No. 6228, July 6, pp. 54-57GlobalMantle, Hotspots
DS2003-1316
2003
Souriau, A.Souriau, A., Teste, A., Chevrot, S.Is there any structure inside the liquid core?Geophysical Research Letters, Vol. 30, 11, 10.1029/2003GLO17008MantleMelting
DS200412-1883
2003
Souriau, A.Souriau, A., Teste, A., Chevrot, S.Is there any structure inside the liquid core?Geophysical Research Letters, Vol. 30, 11, 10.1029/2003 GLO17008MantleMelting
DS201504-0221
2015
Souriau, A.Souriau, A.Presumption of large scale heterogeneity at the top of the outer core basal layer.Earth and Planetary Science Letters, Vol. 415, April pp. 175-182.MantleCore
DS1998-1075
1998
Sours-Page, R.Nielsen, R.L., Michael, P.J., Sours-Page, R.Chemical and physical indicators of compromised melt inclusionsGeochimica et Cosmochimica Acta, Vol. 62, No. 5, pp. 831-9.MantleBasaltic suites, Geochemistry
DS1998-1384
1998
Sours-Page, R.Sours-Page, R., Nielsen, R.L.Constraints on the diversity of mantle melts using rehomogenized meltinclusions.Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1430-1.MantleMelting
DS1991-1636
1991
Sousa, F.J.Sousa, F.J.Revisao da geologia da Porcao southwest do estado de Mato Grosso, s do estado de Rondonia e do leste da BoliviaRevista Brasileira de Geoci?ncias , (in Portugese)., Vol. 21, No. 1, pp. 74-81Bolivia, BrazilRegional geology
DS1991-1637
1991
Sousa, F.J.Sousa, F.J.Review of the geology of the region encompassed by portions of Mato Grosso and Rondonia States (Brasil) and eastern Bolivia.POR.Revista Brasileira de Geociencias, (in Portugese)., Vol. 21, No. 1, March pp. 74-81Brazil, BoliviaGeology, Mato Grosso, Rondonia
DS1960-0402
1963
Sousa E MelloSousa E MelloCompanie de Diamante de AngolaLisbon: Enlg., 168P.Angola, Central AfricaMining, Kimberley
DS201902-0306
2018
Sousa Lima Costa, I.Peres Rocha, M., Assumpcao, M., Fuck, R., Araujo de Azevedo, P., Penna, Crepaldi Affonso, G.M., Sousa Lima Costa, I., Farrapo Albuquetque, D.Llithosphere expression of the boundary between the Amazonian and extra-Amazonian domains of the South American platform from travel time seismic tomography.Researchgate, AGU 1p. Preprint pdfSouth Americacraton

Abstract: The South American platform is the stable part of the South American plate, unaffected by the orogenesis of the Andes and the Caribbean. Its basement is composed of Archean and Proterozoic cratonic blocks amalgamated by mobile belts, and can be separated in two large domains or continental masses: 1) The Amazonian, Northwest-west portion, including the Amazonian craton, related to the Laurentia supercontinent; and 2) the extra-Amazonian, Central-southeast or Brasiliano domain, related to West Gondwana, formed of several paleocontinental fragments, where the São Francisco and Rio de La Plata cratons and the Paranapanema block are the largest. It has been suggested that these two domains are separated by the Transbrasiliano Lineament to the south and the Araguaia Fold Belt to the north. Teleseismic P waves from 4,989 earthquakes recorded by 339 stations operated mainly in Brazil in the last 25 years have been used for relative-time tomography. The Amazonian domain is predominantly characterized by higher velocities. The SW (extra-Amazonian) domain is characterized by several blocks with high velocities, such as in and around the Sao Francisco Craton, and the Paranapanema block. Results of P-wave travel time tomography allowed to observe a strong low-velocity anomaly near 100-200 km depth following the Araguaia-Paraguay fold belt. This strong low-velocity anomaly could be considered the limit between these two domains, reaching lithospheric depths, and does not necessarily follow the Transbrasiliano lineament, especially in its southern portion.
DS201312-0919
2013
Soustelle, V.Tommasi, A., Baptiste, V., Soustelle, V., Le Roux, V., Mainprice, D., Vauchez, A.Heterogeneity and anisotropy in the lithospheric mantle.Goldschmidt 2013, AbstractMantleGeophysics
DS201412-0872
2014
Soustelle, V.Soustelle, V., Walte, N.P., Manthilake, M.A.G.M., Frost, D.J.Melt migration and melt rock reactions in the deforming Earth's upper mantle: experiments at high pressure and temperature.Geology, Vol. 42, pp. 83-86.MantleMelting
DS202101-0041
2020
Soustelle, V.Wang, Y-F., Qin, J-Y., Soustelle, V., Zhang, J-F., Xu, H-J.Pyroxene does not always preserve its source hydrogen concentration: clues from peridotite xenoliths. Geochimica et Cosmochimica Acta, in press availabe 38p. PdfChinametasomatism

Abstract: Water is key to many geodynamical processes in the Earth's upper mantle, yet its preservation in mantle minerals is still debated. To throw some light on this problem, we here carried out an integrated study of whole-rock and mineral chemistry, and hydrogen concentrations in olivine, orthopyroxene, and clinopyroxene within 18 spinel lherzolite samples from three localities (Lianshan, Panshishan, and Tashan) in the Nanjing area, eastern China. Whole-rock and mineral compositions suggest that the studied peridotite samples interacted with melt at different melt/rock ratios following various degrees of partial melting (up to 11%). Fourier transform infrared (FTIR) measurements show that olivine is almost dry (<1 wt ppm H2O) while the cores of orthopyroxene and clinopyroxene contain 14-151 wt ppm H2O and 41-218 wt ppm H2O, respectively. Profile analyses of >70 orthopyroxene grains, which are homogeneous in major-element compositions, covering all the studied samples show hydrogen-depleted rims, indicative of hydrogen diffusional loss. This hydrogen zonation is probably caused by hydrogen chemical diffusion controlled by the mobility of trivalent cations (most likely Al3+) in response to magma degassing or partial melting of peridotite during ascent, or interactions of peridotite with melt, or a combination of these processes. By contrast, no hydrogen zonation is observed in clinopyroxene. Based upon the comparison of chemical compositions (especially Fe and AlIV contents) of clinopyroxene within our samples with those in diffusion experiments, it is inferred that the hydrogen diffusivity in clinopyroxene should be larger than that in orthopyroxene from our samples. This inference points to that clinopyroxene within the studied samples must have experienced diffusional loss of hydrogen as well, suggesting that water concentrations in the lithospheric mantle beneath the study area are probably underestimated. Furthermore, it also implies that orthopyroxene instead of clinopyroxene most likely preserves the in-situ water concentrations at depth, at least at its core. The absence of hydrogen zonation in clinopyroxene can be attributed to its fine-grained nature and fast hydrogen diffusivity. Our FTIR data also show that Lianshan and Tashan samples have water concentration ratio between clinopyroxene and orthopyroxene (RCpx/Opx) of ?2, similar to mantle xenoliths from eastern China and other localities worldwide, yet Panshishan samples have higher RCpx/Opx values (2.3-5.9). Since hydrogen loss is suggested for both pyroxenes, RCpx/Opx of ?2 thus cannot be taken as a reliable indicator of preservation of original water concentration of mantle source and equilibrium partitioning of hydrogen between pyroxene, as opposed to previous suggestions.
DS1900-0501
1907
South Afirca MinesSouth Afirca MinesA Year's Progress at Kimberley. River Diggings Produce Diamonds Valued at 392, 514 Pounds in 1906.South Africa Mines Commerce and Industry, Vol. 5, PT. 1, JULY 6TH. P. 388.Africa, South AfricaProduction
DS1986-0775
1986
South Africa Department Mineral Bureau DirectorySouth Africa Department Mineral Bureau DirectoryOperating diamond Mines in the Republic of South AfricaSouth Africa Department Mineral Bureau Directory, No. 5/85, 46pSouth AfricaDiamond Mines, Overview
DS1994-1667
1994
South Africa Department of Mineral and Energy AffairsSouth Africa Department of Mineral and Energy AffairsSouth Africa's mineral industry 1992/1993. OverviewSouth Africa Department of Mineral and Energy Affairs, 20p.South AfricaMineral industry statistics, Diamond production
DS2003-1317
2003
South Africa Department of Trade and IndustrySouth Africa Department of Trade and IndustrySouth Africa's economic transformation: a strategy for broad based black economicDti, Depratment Of Trade And Commerce, South AfricaBlank
DS1900-0377
1906
South Africa GovernmentSouth Africa GovernmentThe Orange River Colony. Its Resources and DevelopmentBloemfontein: Orange Free State Mines Department Annual Report Fo, Africa, South AfricaMineral Resources, Current Activities, Diamond Occurrence
DS1900-0378
1906
South Africa GovernmentSouth Africa GovernmentThe Lower Vaal River DiggingsSouth Africa, Vol. 71, AUG. 4TH. P. 353.Africa, South AfricaCurrent Activities
DS1900-0379
1906
South Africa GovernmentSouth Africa GovernmentThe River Diggings (1906)South Africa, Vol. 71, AUGUST 11TH. PP. 432-433.Africa, South AfricaCurrent Activities
DS1900-0375
1906
South Africa HandbookSouth Africa HandbookThe Diamond Fields of South Africa. Romance and Reality of Their Discovery and Progress.London: South Africa Handbook, No. 35, 32P.Africa, South AfricaHistory, Vaal River Diggings, Orange River Diggings, Alluvial
DS1860-0726
1892
South Africa MagazineSouth Africa MagazineExcellent Finds at the Vaal River Diggings, Gong-Gong, Waldeck's, large stone 72 ctSouth Africa Magazine., Vol. 14, P. 329.Africa, South Africa, Griqualand West, Vaal RiverAlluvials
DS1860-0727
1892
South Africa MagazineSouth Africa MagazineVaal River Diggings (1892)South Africa Magazine., Vol. 15, JULY 2ND. P. 18.Africa, South AfricaProspecting
DS1860-0775
1893
South Africa MagazineSouth Africa MagazineMr. Dore InterviewedSouth Africa Magazine., Vol. 18, APRIL 15TH. P. 103.Africa, South AfricaHistory
DS1860-0777
1893
South Africa MagazineSouth Africa MagazineThe Big Diamond DealSouth Africa Magazine., Vol. 19, AUG. 19TH. PP. 330-331.Africa, South AfricaEconomics
DS1860-0826
1894
South Africa MagazineSouth Africa MagazineDiamonds in Wood in the de Beers MineSouth Africa Magazine., Vol. 24, Dec. 1ST. P. 396.Africa, South Africa, Griqualand WestMineralogy
DS1860-0865
1895
South Africa MagazineSouth Africa MagazineDiamond Fields. #2South Africa Magazine., Vol. 26, JUNE 8TH. P. 498.Africa, South AfricaCurrent Activities
DS1860-0866
1895
South Africa MagazineSouth Africa MagazineDiamond Fields. #1South Africa Magazine., Vol. 26, MAY 25TH. P. 421.Africa. South AfricaCurrent Activities, Mines
DS1860-0869
1895
South Africa MagazineSouth Africa MagazineDiamond Fields. #3South Africa Magazine., Vol. 26, MAY 4TH. P. 254.Africa, South AfricaEconomics
DS1860-0877
1895
South Africa MagazineSouth Africa MagazineThe Rietspruit Discovery ant holes, KaalvaliSouth Africa Magazine., Vol. 19, PP. XXXIX-XL.South Africa, TransvaalProspecting
DS1900-0519
1907
South Africa MagazineSouth Africa MagazineAn American Kimberley in EmbryoSouth Africa Magazine., Vol. 75, AUGUST 24TH. P. 487.United States, Gulf Coast, Arkansas, PennsylvaniaDiamond Occurrence
DS2000-0920
2000
South Africa Min. EnergySouth Africa Min. EnergySouth Africa's mineral industry 1998/1999. review of selected commodities:precious metals and diamonds.South Africa Min. Energy, pp. 23-30.South AfricaDiamond industry - overview, production
DS1995-1806
1995
South Africa Mineral IndustrySouth Africa Mineral IndustryMineral industry statistics for diamondsSouth Africa Mineral Industry, pp. 21-24.South AfricaEconomics, Diamond production, sales
DS200912-0718
2009
South Africa Mineral Resources Development UnitSouth Africa Mineral Resources Development UnitNew digital map of precious metals and stones in South Africa.[email protected] or [email protected], 1: 1,000,000 DVDAfrica, South AfricaMap
DS1996-1351
1996
South Africa Minerals Industry 1995/96South Africa Minerals Industry 1995/96Diamonds .. overview by A.K. DamarupurshadSouth Africa Minerals Industry 1995/96, pp. 22-27.South AfricaNews item, Diamonds
DS1900-0289
1905
South Africa MinesSouth Africa MinesDiamond Mining in the Orange River ColonySouth Africa Mines, NOV 24TH. AND Dec. 1ST.Africa, South AfricaCurrent Activities
DS1900-0477
1907
South Africa MinesSouth Africa MinesMonastery Diamonds. a Curious Story. Jewellers and Diamond Cutters at fault. the Mine Reopened.South Africa Mines Commerce and Industry, Vol. 5, PT. 1, JUNE 15TH. P. 318.Africa, South AfricaDiamond Morphology
DS1900-0480
1907
South Africa MinesSouth Africa MinesThe Geology of the Smaldeel DistrictSouth Africa Mines Commerce and Industry, Vol. 5, PT. 1, JUNE 22ND. P. 344.Africa, South AfricaGeology
DS1900-0481
1907
South Africa MinesSouth Africa MinesThe Slump in Diamond Shares. Reported Rupture between de Beers and the Premier. Is the Diamond Market Disorganized. Important Developments.South Africa Mines Commerce and Industry, Vol. 5, PT. 1, JULY 20TH. PP. 423-424.Africa, South AfricaInvestment, Cso
DS1900-0482
1907
South Africa MinesSouth Africa MinesThe Geology of Diamonds. a Scientific Controversy. Papers By Dr. Sandberg and Mr. J.p. Johnson.South Africa Mines Commerce and Industry, Vol. 5, PT. 1, AUGUST 31ST. PP. 558-559.South AfricaKimberlite Genesis
DS1900-0483
1907
South Africa MinesSouth Africa MinesDiamond PipesSouth Africa Mines Commerce and Industry, Vol. 5, PT. 1, No. 214, APRIL 13TH. PP. 132-133.Africa, South AfricaKimberlite Genesis
DS1900-0486
1907
South Africa MinesSouth Africa MinesThe Kimberlite Solvent Process. a New and Improved Method To Treat Diamondiferous Ground.South Africa Mines Commerce and Industry, Vol. 5, PT. 1, JUNE 29TH. P. 365.Africa, South AfricaMining Methods
DS1900-0487
1907
South Africa MinesSouth Africa MinesDiamond PecularitiesSouth Africa Mines Commerce and Industry, Vol. 5, PT. 1, JUNE 15TH. P. 314.Africa, South AfricaMonastery, Diamond Morphology
DS1900-0488
1907
South Africa MinesSouth Africa MinesGarnet Pyroxene Nodules: Facts about KimberliteSouth Africa Mines Commerce and Industry, Vol. 5, PT. 1, JUNE 29TH. P. 364.Africa, South AfricaNewlands Mine
DS1900-0489
1907
South Africa MinesSouth Africa MinesRoberts Victor DiamondsSouth Africa Mines Commerce and Industry, Vol. 5, PT. 1, No. 217, MAY 4TH. P. 181.Africa, South AfricaProduction
DS1900-0490
1907
South Africa MinesSouth Africa MinesColumn Report: Beresford; Lace; Rietspruit; HarrisdaleSouth Africa Mines Commerce and Industry, Vol. 5, PT. 1, JULY 13TH. P. 407.Africa, South AfricaProspecting
DS1900-0491
1907
South Africa MinesSouth Africa MinesColumn Report: Celtic; Harrsidale; New EasternSouth Africa Mines Commerce and Industry, Vol. 5, PT. 1, JUNE 29TH. PP. 369-370.Africa, South AfricaProspecting
DS1900-0492
1907
South Africa MinesSouth Africa MinesVaal River Activity: Satisfactory ProgressSouth Africa Mines Commerce and Industry, Vol. 5, PT. 1, No. 216, APRIL 27TH. P. 164.Africa, South AfricaProspecting
DS1900-0493
1907
South Africa MinesSouth Africa MinesColumn Report: Kaffirs dam Closed; Balmoral Resurrected; Lovedale; Tokoza; Pniel; British Diamonds.South Africa Mines Commerce and Industry, Vol. 5, PT. 1, AUGUST 17TH. P. 515.Africa, South AfricaProspecting, Current Activities
DS1900-0494
1907
South Africa MinesSouth Africa MinesColumn Report: Pretoria Districts; Tokoza Diamonds; Rietspruit; Steyn; Premier; Kameelfontein; British Diamonds.South Africa Mines Commerce and Industry, Vol. 5, PT. 1, JUNE 22ND. PP. 347-348.Africa, South AfricaProspecting, Current Activities
DS1900-0495
1907
South Africa MinesSouth Africa MinesColumn Report: Beresford Diamonds; Horseshoe Syndicate; King Syndicate; Kamfersdam; Vulcans; Reitspruit; Queen Victoria Diamonds.South Africa Mines Commerce and Industry, Vol. 5, PT. 1, No. 215, APRIL 20TH. PP. 152-153.Africa, South AfricaProspecting, Current Activities
DS1900-0496
1907
South Africa MinesSouth Africa MinesColumn Report: Voorspoed Diamonds; Beresford; DoornfonteinSouth Africa Mines Commerce and Industry, Vol. 5, PT. 1, No. 218, MAY 11TH. P. 214.Africa, South AfricaProspecting, Current Activities
DS1900-0502
1907
South Africa MinesSouth Africa MinesHarrisdale Estate. an Attractive Proposition; Alluvial Prospects, No Royalty from Diggers.South Africa Mines Commerce and Industry, Vol. 5, PT. 1, No. 221 JUNE 21ST. PP. 276-278.Africa, South AfricaProspecting, Company Report
DS1900-0503
1907
South Africa MinesSouth Africa MinesOrange River ColonyBloemfontein: Orange Free State Mines Department 3rd. Annual Report, 47P.Africa, South AfricaMineral Resources, Current Activities
DS1900-0530
1907
South Africa MinesSouth Africa MinesTwo Rhodesian Ventures Reviewed. the Falcon Mines and the Somabula Diamond Fields. What Developments Has Revealed.South Africa Mines Commerce and Industry, Vol. 5, PT. 1, JUNE 22ND. P. 345.Africa, ZimbabweProspecting, Geology
DS1900-0623
1908
South Africa MinesSouth Africa MinesA Year's Prospecting in the Orange River Colony. the Search for Diamond Farms. Boshof and Vredefort Minerals.South Africa Mines Commerce and Industry, Vol. 6, PT. 1, No. 303, Dec. 26TH. P. 1197.Africa, South AfricaProspecting
DS1997-1088
1997
South Africa MinesSouth Africa MinesA minerals and mining policy for South Africa, Green Paper for publicdiscussionSouth Africa Mines, 72pSouth AfricaMining - legal, Economics, ownership, management, environment, governan
DS2001-1107
2001
South Africa MinesSouth Africa MinesDraft: Mineral policy bill... September 24South Africa Mines, 140p.South AfricaLegal - mineral resources
DS1900-0148
1903
South Africa Mines CommerceSouth Africa Mines CommerceOrange Free State and Transvaal Diamonds Mining CompanySouth Africa Mines Commerce and Industry, Vol. 1, MAY 9TH. PP. 209-210.Africa, South AfricaCompany Report
DS1900-0149
1903
South Africa Mines CommerceSouth Africa Mines CommerceColumn Report: Elandshoek and Pretoria Diamond Fields Developments.South Africa Mines Commerce and Industry, Vol. 1, No. 5, MAY 2ND. PP. 174-175.Africa, South AfricaCurrent Activities
DS1900-0150
1903
South Africa Mines CommerceSouth Africa Mines CommerceColumn Report: Bynestpoort; Elandshoek; Rustenburg; Eastern Diamonds.South Africa Mines Commerce and Industry, Vol. 1, No. 1, MARCH 28TH. PP. 63-64.Africa, South AfricaCurrent Activities, Companies
DS1900-0151
1903
South Africa Mines CommerceSouth Africa Mines CommerceThe Immortal DiamondSouth Africa Mines Commerce and Industry, Vol. 1, AUGUST 22ND. P. 519.Africa, South AfricaDiamond Genesis, Morphology
DS1900-0153
1903
South Africa Mines CommerceSouth Africa Mines CommerceSouth African Diamond Fields (1903)South Africa Mines Commerce and Industry, Vol. 1, AUGUST 15TH. PP. 506-507.Africa, South AfricaHistory, Premier, Geology
DS1900-0154
1903
South Africa Mines CommerceSouth Africa Mines CommerceThe Draft Diamond LawSouth Africa Mines Commerce and Industry, Vol. 1, AUGUST 8TH. PP. 487-488.Africa, South AfricaLaws
DS1900-0155
1903
South Africa Mines CommerceSouth Africa Mines CommerceThe Diamond LawSouth Africa Mines Commerce and Industry, Vol. 1, JULY 4TH. PP. 363-364; JUNE 20TH. PP. 322-323.Africa, South AfricaLaws
DS1900-0156
1903
South Africa Mines CommerceSouth Africa Mines CommerceAmended Diamond OrdinanceSouth Africa Mines Commerce and Industry, Vol. 1, JULY 25TH. PP. 433-434.Africa, South AfricaLaws, Politics
DS1900-0159
1903
South Africa Mines CommerceSouth Africa Mines CommerceColumn Report: River Diggings Find; North Rand Diamonds; Production.South Africa Mines Commerce and Industry, Vol. 1, JULY 25TH. P. 434.Africa, South AfricaProspecting, Current Activities
DS1900-0160
1903
South Africa Mines CommerceSouth Africa Mines CommerceColumn Report: Pretoria Diamond Fields; Kaalfontein; Royal Diamonds.South Africa Mines Commerce and Industry, Vol. 1, SEPT. 12TH. P. 601.Africa, South AfricaProspecting, Current Activities
DS1900-0161
1903
South Africa Mines CommerceSouth Africa Mines CommerceColumn Report: Kaalfontein and Methusaleh Question at Kimberley; Diamonds Near Jacobsdal.South Africa Mines Commerce and Industry, Vol. 1, SEPT. 26TH. P. 643.Africa, South AfricaProspecting, Current Activities
DS1900-0164
1903
South Africa Mines CommerceSouth Africa Mines CommerceColumn Report: Kaalfontein; New Weltevreden; Dutoitspan; Braamfontein; Lace.South Africa Mines Commerce and Industry, Vol. 1, JULY 11TH. P. 393.Africa, South AfricaProspecting, Current Actvities
DS1900-0165
1903
South Africa Mines CommerceSouth Africa Mines CommerceColumn Report: Pretoria Diamond Fields; Orangia; Premier; Monastery.South Africa Mines Commerce and Industry, Vol. 1, No. 2, APRIL 4TH. PP. 82-83.Africa, South AfricaCurrent Activities, Companies
DS1900-0166
1903
South Africa Mines CommerceSouth Africa Mines CommerceColumn Report: Alexandria Mines; Premier; Eastern Diamonds; Claim Pegging; Montrose.South Africa Mines Commerce and Industry, Vol. 1, No. 3, APRIL 11TH. P. 108.Africa, South AfricaCurrent Actvities, Companies
DS1900-0167
1903
South Africa Mines CommerceSouth Africa Mines CommerceThe Premier Mine. the World's Biggest Diamond MineSouth Africa Mines Commerce and Industry, Vol. 1, JUNE 27TH. PP. 344-346.Africa, South AfricaHistory, Company Report
DS1900-0374
1906
South Africa Mining JournalSouth Africa Mining JournalKimberley and the Projected Diamond FusionSouth African Mining Journal, Feb. 12TH. P. 557.Africa, South AfricaProspecting
DS1900-0616
1908
South Africa Mining JournalSouth Africa Mining JournalHow Harrisdale Made HistorySouth African Mining Journal, JUNE 6TH. P. 371.Africa, South AfricaCurrent Activities, Prospecting
DS1900-0392
1906
South Africa Mining ReviewSouth Africa Mining ReviewAn American KimberleySouth Africa Mining Review, Vol. 72, Oct. 13TH. P. 81.United States, Kentucky, AppalachiaDiamond Occurrence, Diamonds Notable
DS1900-0475
1907
South Africa Mining ReviewSouth Africa Mining ReviewAfrican Alluvial Ltd. #1South Africa Mining Review, Vol. 7, PT. 2, Dec. 4TH. P. 323.Africa, South AfricaAlluvial Diamond Placers, Diamond Recovery
DS1900-0478
1907
South Africa Mining ReviewSouth Africa Mining ReviewAfrican Alluvial Ltd. #2South Africa Mining Review, Vol. 76, Oct. 19TH. P. 187.Africa, South AfricaDredging, Alluvial Diamond Placers
DS1900-0479
1907
South Africa Mining ReviewSouth Africa Mining ReviewThe Origin of Diamonds. Criticism of Dr. Voit's TheoriesSouth Africa Mining Review, Vol. 75, SEPT. 14TH. P. 704.Africa, South AfricaGenesis
DS1900-0484
1907
South Africa Mining ReviewSouth Africa Mining ReviewDiggers and Valuation PercentagesSouth Africa Mining Review, Vol. 76, Oct. 26TH. P. 226.Africa, South AfricaMineral Economics, Prices
DS1900-0485
1907
South Africa Mining ReviewSouth Africa Mining ReviewEngineering Notes for South African ReadersSouth Africa Mining Review, Vol. 76, Nov. 2ND. PP. 316-317.Africa, South AfricaMining Engineering
DS1900-0499
1907
South Africa Mining ReviewSouth Africa Mining ReviewOn the Vaal River Diggings. a Visit to the Alluvial FieldsSouth Africa Mining Review, Vol. 5, PT. 1, MARCH 30TH. PP. 78-91.Africa, South AfricaAlluvial Diamond Placers
DS1900-0504
1907
South Africa Mining ReviewSouth Africa Mining ReviewGlen Diamond SyndicateSouth Africa Mining Review, Vol. 75, P. 647. SEPT. 7TH.Africa, South AfricaAlluvial Diamond Placers
DS1900-0505
1907
South Africa Mining ReviewSouth Africa Mining ReviewVaal River Diggings (1907)South Africa Mining Review, Vol. 74, APRIL 27TH. P. 279.Africa, South AfricaMining Engineering
DS1900-0506
1907
South Africa Mining ReviewSouth Africa Mining ReviewDiving for DiamondsSouth Africa Mining Review, Vol. 75, AUG. 3RD. P. 296.Africa, South AfricaMining Engineering
DS1900-0614
1908
South Africa Mining ReviewSouth Africa Mining ReviewThe Great Premier. Will the Company Cheapen Diamonds?South Africa Mining Review, Vol. 6, PT. 2, OCTOBER.Africa, South AfricaEconomics
DS1900-0615
1908
South Africa Mining ReviewSouth Africa Mining ReviewHarrisdale River DiggingsSouth Africa Mining Review, Vol. 6, PT. 2, Oct. 24TH. P. 941.Africa, South AfricaCurrent Activities
DS1900-0618
1908
South Africa Mining ReviewSouth Africa Mining ReviewYears Prospecting in the Orange River ColonySouth Africa Mining Review, Vol. 6, PT. 2, Dec. 26TH. P. 1197.Africa, South AfricaDiamonds, Prospecting
DS1900-0619
1908
South Africa Mining ReviewSouth Africa Mining ReviewThe Price of River StonesSouth Africa Mining Review, Vol. 6, PT. 1, JUNE 27TH. P. 454.Africa, South AfricaMineral Economics, Prices, Diamonds
DS1900-0621
1908
South Africa Mining ReviewSouth Africa Mining ReviewNorthern Transvaal Copper and Diamonds. Seta and BergdahlSouth Africa Mining Review, Vol. 6, PT. 2, Nov. 21ST. P. 1044.Africa, South AfricaDiamond Occurrence
DS202105-0793
2021
South African Diamond Producers OrganizationSouth African Diamond Producers OrganizationStrategy for short and medium term.SAPP, 9p. Pdf executive summaryAfrica, South Africaalluvials, legal
DS1860-0425
1884
South African HandbookSouth African HandbookAlluvial Gold and Diamonds in the Earlier Days. #1South African Handbook, No. 10, PP. 26-31.Africa, South Africa, Cape ProvinceHistory
DS1996-1352
1996
South African Institute of Mining and Metallurgy (IMM).South African Institute of Mining and Metallurgy (IMM).Hidden wealth proceedings of a conference on innovative technologySouth African Institute of Mining and Metallurgy (IMM)., $ 70.00 United StatesSouth AfricaBook - ad, Metallurgy
DS1994-1668
1994
South African Journal of GeologySouth African Journal of GeologySpecial issue on layered igneous rocksSouth African Journal of Geology, Vol. 97, No. 4, Dec. pp. 389-520South AfricaLayered intrusions, Deposit -Bushveld Complex
DS1860-0867
1895
South African Mining JournalSouth African Mining JournalDiscussion on the Validity of a Stone Found in the Monastery Mine.South African Mining Journal, Vol. 4, PT. 1, AUGUST 3RD. P. 929.Africa, South AfricaDiamond Occurrence
DS1860-0868
1895
South African Mining JournalSouth African Mining JournalGamble on Stocks.. Robinson DiamondsSouth African Mining Journal, Vol. 4, PT. 1, Feb. 16TH. P. 408.Africa, South AfricaEconomics
DS1860-0871
1895
South African Mining JournalSouth African Mining JournalRobinson Diamonds Vaal RiverSouth African Mining Journal, Vol. 4, PT. 1, MARCH 2ND. P. 459.Africa, South AfricaMining Recovery
DS1860-0872
1895
South African Mining JournalSouth African Mining JournalKimberley and Its Diamonds (1895)South African Mining Journal, Vol. 4, PT. 1, AUGUST 17TH. PP. 981-983.Africa, South AfricaHistory, Geology
DS1860-0874
1895
South African Mining JournalSouth African Mining JournalMinerals in the Free State, Orange RiverSouth African Mining Journal, Vol. 4, PT. 1, MARCH 9TH. PP. 488-489.Africa, South AfricaProspecting
DS1860-0875
1895
South African Mining JournalSouth African Mining JournalDiamonds Found Near Mahash's on the Lebombo Range East of Southwest Swaziland.South African Mining Journal, Vol. 4, PT. 1, Jan. 12TH. PP. 299-300.Africa, SwazilandDiamond Occurrence
DS1900-0004
1900
South African Mining JournalSouth African Mining JournalLatest Griqualand West Diamond Discoveries, PostmasburgSouth African Mining Journal, JAN 24TH. P. 439.Africa, South AfricaCurrent Activities
DS1900-0634
1908
South African Mining JournalSouth African Mining JournalA New Menace to the Diamond MarketSouth African Mining Journal, Vol. 6, PT. 1, MAY 23RD. P. 315.United States, Gulf Coast, ArkansasEconomics
DS1900-0635
1908
South African Mining JournalSouth African Mining JournalAmerican Diamonds. #3South African Mining Journal, Vol. 6, PT. 1, MAY 2ND. PP. 241-242.United States, Gulf Coast, ArkansasEconomics
DS1900-0723
1909
South African Mining JournalSouth African Mining JournalThe Origin of the Vaal River Diamonds. Some Recent Dicoveries and Important Deductions. Mr Harger's Paper. New Theories on the Genesis of the Diamonds.South African Mining Journal, Vol. 7, PT. 2, No. 342, SEPT. 25TH. PP. 41-42. PT. 2, No. 34Africa, South AfricaDiamond genesis
DS1900-0724
1909
South African Mining JournalSouth African Mining JournalThe Origin of Diamonds (1909)South African Mining Journal, Vol. 7, PT. 2, Oct. 2ND. No. 343, PP. 61-62.Africa, South AfricaDiamond genesis
DS1900-0726
1909
South African Mining JournalSouth African Mining JournalRiver Diggers' EarningsSouth African Mining Journal, Vol. 7, PT. 1, JUNE 26TH. P. 457.Africa, South AfricaMineral Economics, Earnings
DS1900-0727
1909
South African Mining JournalSouth African Mining JournalAnother Blue Ground DisintegratorSouth African Mining Journal, Vol. 7, PT. 1, MARCH 15TH. P. II.Africa, South AfricaMining Engineering, Methods
DS1900-0728
1909
South African Mining JournalSouth African Mining JournalThe Kimberley and the Vaal River Diamond FieldsSouth African Mining Journal, Vol. 7, PT. 1, P. 439.Africa, South AfricaAlluvial Diamond Placers
DS1900-0729
1909
South African Mining JournalSouth African Mining JournalThe Kimberley and Vaal River Diamond Fields. Last Year's Operations and Some Striking Statistics of Valuable Finds. a Review of the River Diggings.South African Mining Journal, Vol. 7, PT. 1, JUNE 19TH. P. 439.Africa, South AfricaMining Economics, Production, Alluvial Diamond Placers
DS1900-0731
1909
South African Mining JournalSouth African Mining JournalThe Caisson on the River Diggings VaalSouth African Mining Journal, Vol. 6, PT. 2, Jan. 9TH., PP. 1245-1246. ILLUSTRATED.Africa, South AfricaAlluvial Diamond Placers
DS1900-0732
1909
South African Mining JournalSouth African Mining JournalThe River Diggings (1909) VaalSouth African Mining Journal, Vol. 7, PT. 2, Dec. 4TH. No. 352, P. 323.Africa, South AfricaMining Engineering
DS1900-0733
1909
South African Mining JournalSouth African Mining JournalGerman Southwest African Diamond Fields #1South African Mining Journal, Vol. 7, PT. 2, Dec. 18TH. PP. 385-386.Africa, NamibiaDiamond Occurrence
DS1900-0739
1909
South African Mining JournalSouth African Mining JournalMr. Draper and the Arkansas DiamondsSouth African Mining Journal, Vol. 7, PT. 2, Oct. 9TH. P. 98.United States, Gulf Coast, Arkansas, PennsylvaniaDiamond genesis
DS1988-0657
1988
South Australia Department of Mines and EnergySouth Australia Department of Mines and EnergyMineral Resources Review. Section on Diamond explorationSouth Australia Department of Mines and Energy, Review No. 156 ppAustralia, South AustraliaDiamond exploration overv
DS1996-1353
1996
South Australia Mines and EnergySouth Australia Mines and EnergyDiamonds ... brief one paragraph on Echunga and Eurelia diamondsMineral Exploration and Development in South Australia, p. 68.AustraliaDiamonds -brief
DS201807-1516
2018
Southam, C.Mervine, E.M., Wilson, S.A., Power, I.M., Dipple, G.M., Turvey, C.C., Hamilton, J.L., Vanderzee, S., Raudsepp, M., Southam, C., Matter, J.M., Kelemen, P.B., Stiefenhofer, J., Miya, Z., Southam, G.Potential for offsetting diamond mine carbon emissions through mineral carbonation of processed kimberlite: an assessment of De Beers mine sites in South Africa and Canada.Mineralogy and Petrology, 10.1007/ s00710-018- 0589-4, 14p.Africa, South Africa, Canada, Northwest Territories, Ontariodeposit - Venetia, Voorspoed, Gahcho Kue, Victor, Snap Lake

Abstract: De Beers kimberlite mine operations in South Africa (Venetia and Voorspoed) and Canada (Gahcho Kué, Victor, and Snap Lake) have the potential to sequester carbon dioxide (CO2) through weathering of kimberlite mine tailings, which can store carbon in secondary carbonate minerals (mineral carbonation). Carbonation of ca. 4.7 to 24.0 wt% (average?=?13.8 wt%) of annual processed kimberlite production could offset 100% of each mine site’s carbon dioxide equivalent (CO2e) emissions. Minerals of particular interest for reactivity with atmospheric or waste CO2 from energy production include serpentine minerals, olivine (forsterite), brucite, and smectite. The most abundant minerals, such as serpentine polymorphs, provide the bulk of the carbonation potential. However, the detection of minor amounts of highly reactive brucite in tailings from Victor, as well as the likely presence of brucite at Venetia, Gahcho Kué, and Snap Lake, is also important for the mineral carbonation potential of the mine sites.
DS200912-0181
2009
Southam, G.Donnkervoort, L.J., Southam, G.Microbial response in peat overlying kimberlite pipes in the Attawapiskat area, northern Ontario.EOS Transaction of AGU, Vol. 90, no. 22 1p. abstractCanada, Ontario, AttawapiskatGeochemistry
DS201708-1770
2017
Southam, G.Southam, G.Microbial response to the presence of buried kimberlite pipes in the Attwapiskat region, northern Ontario: bacteria-kimberlite interactions.11th. International Kimberlite Conference, PosterCanada, Ontario, AttawapiskatMicrobiology
DS201807-1516
2018
Southam, G.Mervine, E.M., Wilson, S.A., Power, I.M., Dipple, G.M., Turvey, C.C., Hamilton, J.L., Vanderzee, S., Raudsepp, M., Southam, C., Matter, J.M., Kelemen, P.B., Stiefenhofer, J., Miya, Z., Southam, G.Potential for offsetting diamond mine carbon emissions through mineral carbonation of processed kimberlite: an assessment of De Beers mine sites in South Africa and Canada.Mineralogy and Petrology, 10.1007/ s00710-018- 0589-4, 14p.Africa, South Africa, Canada, Northwest Territories, Ontariodeposit - Venetia, Voorspoed, Gahcho Kue, Victor, Snap Lake

Abstract: De Beers kimberlite mine operations in South Africa (Venetia and Voorspoed) and Canada (Gahcho Kué, Victor, and Snap Lake) have the potential to sequester carbon dioxide (CO2) through weathering of kimberlite mine tailings, which can store carbon in secondary carbonate minerals (mineral carbonation). Carbonation of ca. 4.7 to 24.0 wt% (average?=?13.8 wt%) of annual processed kimberlite production could offset 100% of each mine site’s carbon dioxide equivalent (CO2e) emissions. Minerals of particular interest for reactivity with atmospheric or waste CO2 from energy production include serpentine minerals, olivine (forsterite), brucite, and smectite. The most abundant minerals, such as serpentine polymorphs, provide the bulk of the carbonation potential. However, the detection of minor amounts of highly reactive brucite in tailings from Victor, as well as the likely presence of brucite at Venetia, Gahcho Kué, and Snap Lake, is also important for the mineral carbonation potential of the mine sites.
DS1992-1457
1992
Southard, D.A.Southard, D.A.Compression of digitized map imagesComputers and Geosciences, Vol. 18, No. 9, pp. 1213-1253GlobalComputer, Digitized mapping
DS1990-0890
1990
Southard, J.B.Kuhnle, R.A., Southard, J.B.Flume experiments on the transport of heavy minerals in gravel bedstreamsJournal of Sedimentary Petrology, Vol. 60, No. 5, September pp. 687-696GlobalExperimental - alluvial, Heavy minerals
DS1986-0776
1986
Souther, J.G.Souther, J.G.The western Anahim belt: root zone of a peralkaline magma systemCanadian Journal of Earth Sciences, Vol. 23, pp. 895-908.British ColumbiaDike swarms
DS1998-1385
1998
Southern African Development CommunitySouthern African Development CommunityDiamonds in the SADC regionMineral Res. Surv. Prog., No. 3, 36p. 16p. appendicesSouth Africa, Swaziland, Tanzania, Zimbabwe, Angola, Botswana, LesothoAlluvial, marine diamond, kimberlite, paleoplacers, Diamond production, potential
DS1996-0015
1996
Southern P.A.Allan, J.G., Southern P.A.Baseline dat a collectionEnvironmental Management in Australia Minerals and Energy, UNSW Press, pp. 676-685AustraliaMineral processing, Environmental - mining
DS200612-1338
2006
SouthernEra DiamondsSouthernEra DiamondsBoard restructured.Mineweb, June 8, 2p.Africa, South AfricaNews item - SouthernEra
DS1940-0130
1946
Southey, M.N.Southey, M.N.Kimberley and the Diamond Fields of Griqualand West 1869-190Cape Town: Msc. Thesis, University Cape Town., 28P.South AfricaHistory, Bibliography
DS1998-1386
1998
Southwell, K.Southwell, K.Meteorites: diamonds in the dustNature, Vol. 392, No. 6672, March 12, p. 133-134.GlobalMeteorites
DS1990-1398
1990
Southwick, D.C.Southwick, D.C.The essential role of scientific drilling in Precambrian research inMinnesotaGeological Society of America (GSA) Annual Meeting, Abstracts, Vol. 22, No. 7, p. A198MinnesotaBedrock, Crust
DS1975-0208
1975
Southwick, D.L.Weiblen, P.W., Morey, G.B., Southwick, D.L.A Geological Model for the Evolution of the Midcontinent Gravity High. Part Ii, Petrology.Eos, Vol. 56, No. 9, P. 603. (abstract.).GlobalMid-continent
DS1975-0431
1976
Southwick, D.L.Weiblen, P.W., Morey, G.B., Southwick, D.L., Walton, M.S.The Effect of Ancestral Structures on the Evolution of the Midcontinent Rift and the Duluth Complex.International Geological Congress, 25TH. Vol. 3, P. 695. (abstract.).GlobalMid-continent
DS1982-0447
1982
Southwick, D.L.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
DS1987-0705
1987
Southwick, D.L.Southwick, D.L., Chandler, V.W.Mica bearing olivine pyroxenite of possible lamproite kimberlite affinityin Central MinnesotaEconomic Geology, Vol. 82, No. 1, Jan. Feb. pp. 212-217MinnesotaUSA, Lamproite
DS1990-0305
1990
Southwick, D.L.Chandler, V.W., Southwick, D.L.Aeromagnetic MinnesotaEos, Vol. 71, No. 11, March 13, pp. 329MinnesotaGeophysics -aeromagnetics, Brief overview
DS1991-1638
1991
Southwick, D.L.Southwick, D.L.On the genesis of Archean granite through two stage melting of the Quetico accretionary prism at a transpressional plate boundaryGeological Society of America (GSA) Bulletin, Vol. 103, No. 11, November pp. 1385-1394OntarioAccretionary complex, Tectonics
DS1991-1639
1991
Southwick, D.L.Southwick, D.L., Morey, G.B.Precambrian geologic framework in MinnesotaMinnesota Geological Survey, Information Circular No. 34, pp. 49-56MinnesotaPrecambrian geology, Tectonics
DS1991-1640
1991
Southwick, D.L.Southwick, D.L., Morey, G.B.Tectonic imbrication and foredeep development in the Penokean Orogen, east-central Minnesota-interpret. on regional geophysics and the results of testdrillingUnited States Geological Survey (USGS) Bulletin, No. 1904 C, 15pMinnesotaTectonics, Geophysics
DS1991-1641
1991
Southwick, D.L.Southwick, D.L., Morey, G.B.Tectonic imbrication and foredeep developments in the Penokean Orogen, east central Minnesota: an interp. based on regional geophysics, results of testdrillingUnited States Geological Survey (USGS) Bulletin, No. B 1904-C, D, pp. C 1-17. $ 2.00MinnesotaTectonics, Geophysics -magnetics
DS1991-1642
1991
Southwick, D.L.Southwick, D.L., Morey, G.B., Holst, T.B.Tectonic imbrication and foredeep development in the Penokean Orogeny, east central Minnesota: an interpretation based on regional geophysics and drillUnited States Geological Survey (USGS) Bulletin, No. 1904 C-D, 17p. and 10pMinnesotaTectonics, Penokean Orogeny
DS1984-0428
1984
Southworth, C.S.Kover, A.N., Jones, J.E., Southworth, C.S.Major Sources of New Radar Dat a for Exploration ResearchUnited States Geological Survey (USGS), pp. 833-61.AppalachiaRemote Sensing - Radar
DS1993-1515
1993
Southworth, C.S.Southworth, C.S., Gray, K.J., Sutter, J.F.Middle Eocene intrusive igneous rocks of the Central Appalachian Valley and Ridge Province -setting, chemistry, structureU.s. Geological Survey Bulletin, Vol. 1839-J, 21pAppalachiaIgneous rocks, Geochemistry
DS201312-0404
2013
Southworth, R.Howell, D., Stern, R.A., Griffin, W.L., Southworth, R., Mikhail, S., Stachel, T., Verchovsky, A.B., O'Reilly, S.Y., Pearson, N.J.New thermodynamic models and calculated phase equilibration temperatures in NCFMAS for basic and ultrabasic compositions through the transition zone into the uppermost lower mantle.Goldschmidt 2013, AbstractTechnologyCrystallography
DS201312-0406
2015
Southworth, R.Howell, D., Stern, R.A., Griffin, W.L., Southworth, R., Mikhail, S., Stachel, T.Nitrogen isotope systematics and origins of mixed-habit diamonds.Geochimica et Cosmochimica Acta, Vol. 157, pp. 1-12.Africa, South AfricaDeposit - Roberst Victor
DS201412-0581
2014
Southworth, R.Mikhail, S., Verchovsky, A.B., Howell, D., Hutchison, M.T., Southworth, R., Thomson, A.R., Warburton, P., Jones, A.P., Milledge, H.J.Constraining the internal variability of the stable isotopes of carbon and nitrogen within mantle diamonds.Chemical Geology, Vol. 366, pp. 14-23.Africa, Russia, South America, BrazilDiamond inclusions
DS201412-0873
2014
Southworth, R.Southworth, R.Understanding delta 15N variations in the mantle using integral variabilities in natural diamonds.ima2014.co.za, PosterTechnologyDiamond morphology
DS201606-1094
2015
Southworth, R.Howell, D., Stern, R.A., Griffin, W.L., Southworth, R., Mikhail, S., Stachel, T.Nitrogen isotope systematics and origins of mixed habit diamonds.Geochimica et Cosmochimica Acta, Vol. 157, pp. 1-12.TechnologyDiamond morphology

Abstract: Nitrogen isotope values from mantle diamonds are a commonly used tracer in the quest to track volatiles within the Earth’s mantle through deep time. Interpretations of this isotope data are valid so long as stable isotope fractionation processes in the mantle are understood. The fractionation of nitrogen isotopes between {1 1 1} and {1 0 0} growth sectors is well documented for high-pressure high-temperature (HPHT) synthetic diamonds, but there is little data on whether it also occurs in natural mixed-habit diamonds. We present 91 in-situ nitrogen isotope (?15N) measurements, along with carbon isotope (?13C) values and nitrogen abundances [N], obtained from three mixed-habit diamonds by secondary ion mass spectrometry (SIMS). While the well-documented enrichment of nitrogen concentrations in octahedral sectors compared to contemporaneous cuboid sectors is observed, a similarly clear disparity is not obvious in the ?15N data. Whereas HPHT synthetic diamonds exhibit 15N enrichment in the {1 0 0} sectors by ?+30‰, the mixed-habit diamonds studied here show enrichment of the octahedral sectors in 15N by only 0.4-1‰. This major difference between HPHT synthetic and natural mixed-habit diamonds is proposed to be the result of different physical properties of the growth interfaces. The smooth interfaces of the octahedral sectors are the same in both types of crystal, but the outermost atoms on the smooth cube interfaces of an HPHT synthetic diamond behave differently to those on the rough cuboid interfaces of the natural mixed-habit diamonds, resulting in different ?15N values. Both the ?13C (average of ??8.7‰) and ?15N (average of ?0‰) data show only minor offsets from the typical mantle values (?13C = ?5 ± 3‰, ?15N = ?5 ± 4‰). This may indicate diamond formation from a mantle derived fluid/melt containing a minor subducted component (lowering ?13C values and elevating ?15N) or relate to moderate degrees of isotopic fractionation of a pure mantle fluid/melt by prior diamond precipitation. The homogeneous nature of both the carbon and nitrogen isotopic compositions of all three diamonds, however, documents continuous and unlimited supply of diamond forming fluid/melt, with a constant composition. Such homogenous isotopic compositions exclude fluid mixing or isotopic fractionation close to the site of diamond formation and preclude distinguishing between these two processes based on diamond analyses alone.
DS1900-0220
1903
Souvielle, E.M.Souvielle, E.M.The Origin of the Diamond (meteoritic)Scientific American Supplement., Vol. 56, No. 1437, JULY 18TH. PP. 23035-36.RussiaDiamond Genesis
DS201112-0015
2011
Souza, A.J.Amoudry, L.O., Souza, A.J.Deterministic coastal morphological and sediment transport modeling: a review and discussion.Reviews of Geophysics, Vol. 49, 21p. RG2002GlobalSediment dynamics - not specific to diamonds but useful
DS2000-0189
2000
Souza, C.R.Correa-Gomes, L.C., Oliveira, E.P., Souza, C.R.Kinematic analysis of coeval Neoproterozoic shear zones and alkaline dike swarms in SSE Bahia State, Brasil.Igc 30th. Brasil, Aug. abstract only 1p.Brazil, BahiaDike swarms - Itabuna Itaju do Colonia shear zone, Craton
DS1997-1089
1997
Souza, J.C.Souza, J.C., Sampaio, C.H.Technical and economical studies on the industrialization of precious stones in southern Brasil17th. World Mining Congress Oct. Mexico, pp. 115-125BrazilGemstones
DS1991-1688
1991
Souza, J.C.F.Tallarico, F.H.B., Souza, J.C.F., Leonardos, O.H., Meyer, H.O.A.The Mat a Do Lenco mica-rich kimberlite, western Minas GeraisProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 408-409BrazilMacrocrysts, Mineral chemistry
DS202008-1382
2020
Souza, M.R.W.Conceicao, R.V., Marcon, V.H., Souza, M.R.W., Carniel, L.C., Quinteiro, R.V.S., Rovani, P., Mizusaki, A.M.P., Spitzenberger, M.S.Carbonatite/lamproite liquid imissibility in the Earth's mantle through the nefeline-diopside-kalsilite+-CO2, CH4, H2O diagram.Goldschmidt 2020, 1p. AbstractMantlelamproite

Abstract: The presence and speciation of volatile C-H-O elements in the silicate systems play an important role in the genesis of magmas on the Earth’s mantle, due to the fact that these elements, mainly in the form of H2O, CO2, CH4 and CxHy, decrease the solidi temperatures of source rocks, making magmatism possible in Earth’s present day thermal conditions [1]. Among those elements, carbon is the only element that changes its valence according to the oxygen fugacity (fO2) conditions of the environment, resulting in different speciation, as: CO3 -2, CO2, Cgraphite/diamond, CH4 or heavier hydrocarbons. In the present work, we are determining phase stability of minerals, water, CO2 and CH4 in the system Nefeline-Kalsilite-Diopside. Our experiments are conducted under 4.0 GPa and temperatures up to 1300°C, using a 1000 tonf hydraulic press coupled with toroidal chambers. Preliminary experiments performed at 1300°C and 4.0GPa (initial composition in the Olivine-Quartz- Kalsalite/Nepheline system: 40mol% Ol90, 40mol% Nph50Kls50 and 20mol% Qz, PH2O,CO2=Ptotal) resulted in the formation of forsterite (Fo90) in equilibrium with phlogopite (Phl), melt and volatile phases (CO2 and CH4). Closer to the Diopside vertice, the addition of CO3 to the sample resulted in a imisibility of a carbonatitic and a silicatic melt, in which the carbonititic melt is enriched in sodium, while the silcate melt is enriched in potassium. Appart from that, experiments in different parts of the diagram suggest compositions from nephelinite-kalsilitite to lamproites composition for the silicate melt in equilibrium with diopside (solid solution with omphacite) and phlogopite. This work is a continuation of previous work in the anhydrous diagram and future works will provide the addition of CH4 as the volatile phase
DS201712-2725
2017
Souza, V.S.Rossoni, M.B., Bastos Neto, A.C., Souza, V.S., Marquea, J.C., Dantas, E., Botelho, N.F., Giovannini, A.L., Pereira, V.P.U-Pb zircon geochronological investigation on the Morro dos Seis Lagos carbonatite complex and associated Nb deposit ( Amazonas, Brazil).Journal of South American Earth Sciences, Vol. 80, pp. 1-17.South America, Brazilcarbonatite

Abstract: We present results of U-Pb dating (by MC-ICP-MS) of zircons from samples that cover all of the known lithotypes in the Seis Lagos Carbonatite Complex and associated lateritic mineralization (the Morro dos Seis Lagos Nb deposit). The host rock (gneiss) yielded an age of 1828 ± 09 Ma interpreted as the crystallization time of this unit. The altered feldspar vein in the same gneiss yielded an age of 1839 ± 29 Ma. Carbonatite samples provided 3 groups of ages. The first group comprises inherited zircons with ages compatible with the gneissic host rock: 1819 ± 10 Ma (superior intercept), 1826 ± 5 Ma (concordant age), and 1812 ± 27 Ma (superior intercept), all from the Orosirian. The second and the third group of ages are from the same carbonatite sample: the superior intercept age of 1525 ± 21 Ma (MSWD ¼ 0.77) and the superior intercept age of 1328 ± 58 Ma (MSWD ¼ 1.4). The mineralogical study indicates that the ~1.3 Ga zircons have affinity with carbonatite. It is, however, a tendence rather than a well-defined result. The data allow state that the age of 1328 ± 58 Ma represents the maximum age of the carbonatite. Without the same certainty, we consider that the data suggest that this age may be the carbonatite age, whose emplacement would have been related to the evolution of the K'Mudku belt. The best age obtained in laterite samples (a superior intercept age of 1828 ± 12 Ma) is considered the age of the main source for the inherited zircons related to the gneissic host rock.
DS202005-0770
2020
Souza, V.S.Weska, R.K., Ferreira Barbosa, P., Martins, M.V.C., Souza, V.S., Dantas, E.L.Pectolite in the Carolina kimberlitic intrusion, Espigao D'Oeste - Rondonia, Brazil. ( Pimenta Bueno field)Journal of South American Earth Sciences, Vol. 100, 10.1016/j.jsames.2020.102583 7p. PdfSouth America, Brazil, Rondoniadeposit - Carolina

Abstract: In this study, we characterize pectolite that occurs in a Carolina kimberlitic intrusion from the Pimenta Bueno Kimberlite Field (PBKF). The PBKF is the only kimberlite field of Permo-Carboniferous age in Brazil and is found on the southern Amazonian Craton. Pectolite, an Na-Ca-silicate usually identified in alkaline rocks as a primary mineral, is not common in the mineral paragenesis of kimberlites and is described here for the first time in Brazil. The genesis of pectolite in kimberlite has been well-studied and can be interpreted as a primary or secondary mineral resulting from the infiltration of an Na-rich fluid into metasomatic reactions. In the rocks from the PBKF, pectolite mainly occurs as fibrous and radial aggregates enriched in K2O that grow between olivine partially altered to serpentine and phlogopite. The results of field and petrographic observations suggest that the PBKF pectolite is of secondary origin, having formed during the hydrothermal alteration of the Carolina kimberlitic intrusion.
DS202203-0335
2022
Souza, V.S.Barbosa, N.A., Fuck, R.A., Souza, V.S., Dantas, E.L., Tavares Jr., S.S.Evidence of Paleoproterozoic SLIP, northern Amazonian craton, Brazil.Journal of South American Earth Sciences, Vol. 111, 19p. PdfSouth America, Brazilgeophysics - seismics

Abstract: The Orocaima SLIP consists of an association of acid-intermediate volcanic-plutonic rocks. The volcanic rocks were generated in explosive eruptions through low eruptive columns, probably associated with fissural volcanism in the north of the Amazonian Craton, Brazil, between 2.0 and 1.98 Ga. It generated ignimbrites, whose facies (volcanic breccia rich in lithic, lapilli-tuff and lithic lapilli-tuff) show the proximity of the source. The extensive area of ca. 200.000 km2 of ignimbrite, rhyolite and dacite deposits, as well as the age range (2.0-1.98 Ga) and geochemical signatures suggest that the Orocaima volcano-plutonism may correspond to one of the oldest silicic LIPs in the world. The silicic volcanism is essentially subaerial and characterized by high-grade ignimbrites (densely welded) and subordinate lava, the ages of which indicate the longevity of the volcanic event in the Orosirian. They are included in the Surumu Group and comprise rocks with high-K calc-alkaline affinities and were emplaced in a subduction-related setting, similar to the rocks that extend through Venezuela, Guyana and Suriname (Cuchivero-Surumu-Iwokrama-Dalbana metavolcanic belt - CSID). The occurrence of mafic fragments disseminated in volcanic and granitic rocks in the north of Roraima, Brazil and in other segments of the CSID belt suggests the coexistence of acid and basic magmas. Except for one sample (?Nd(t) = -2.3), the Nd isotopic data of analyzed Surumu Group volcanic rocks yielded positive ?Nd(t) values (0.5-4.48; TDM = 2.0-2.47 Ga), suggesting generation from magmas derived from the mantle or from the melting of new juvenile crust. The Orocaima volcanism bears no evidence of involvement of Archean sources in the generation of the rocks. Thus, the Orocaima volcano-plutonism may represent one of the most significant ignimbrite eruption events during the Palaeoproterozoic in the world.-
DS201112-0756
2011
Souza, Z.S.Oliveira, E.P., Souza, Z.S., McNaughton, N.J., Lafon, J.M., Costa, F.G., Figueiro, A.M.The Rio Capim volcanic plutonic sedimentary belt, Sao Francisco craton, Brazil: geological, geochemical and isotopic evidence for oceanic accretion during....Gondwana Research, Vol. 19, 3, pp. 735-750.South America, BrazilPaleoproterozoic continental collision
DS200512-1137
2004
Souza de Alvarenga, C.J.Ventura Santos, R., Souza de Alvarenga, C.J., Babinski, M., Ramos, M.L.S., Cukrov, N., Fonsec, M.A., Da NorbregaCarbon isotopes of Mesoproterozoic Neoproterozoic sequences from southern Sao Francisco craton and Aracuai Belt, Brazil: paleogeorgraphic implications.Journal of South American Earth Sciences, Vol. 18, 1, Dec. 30, pp. 27-39.South America, BrazilGeomorphology, glaciation, geochronology,carbonatites
DS201709-2043
2017
Souza Filhio, A.G.Pimenta Martins, L.G., Matos, M.J.S., Paschoal, A.R., Freire, P.T.C., Andrade, N.F., Aguiar, A.L., Kong, J., Neves, B.R.A., de Oliveira, A.B., Mazzoni, M.S.C., Souza Filhio, A.G., Cancad, L.G.Raman evidence for pressure induced formation of diamondene.Nature Communications, Vol. 8, 9p.Technologydiamondene

Abstract: Despite the advanced stage of diamond thin-film technology, with applications ranging from superconductivity to biosensing, the realization of a stable and atomically thick two-dimensional diamond material, named here as diamondene, is still forthcoming. Adding to the outstanding properties of its bulk and thin-film counterparts, diamondene is predicted to be a ferromagnetic semiconductor with spin polarized bands. Here, we provide spectroscopic evidence for the formation of diamondene by performing Raman spectroscopy of double-layer graphene under high pressure. The results are explained in terms of a breakdown in the Kohn anomaly associated with the finite size of the remaining graphene sites surrounded by the diamondene matrix. Ab initio calculations and molecular dynamics simulations are employed to clarify the mechanism of diamondene formation, which requires two or more layers of graphene subjected to high pressures in the presence of specific chemical groups such as hydroxyl groups or hydrogens.
DS2000-0604
2000
Souza Filho, C.R.Machado, I.F., Souza Filho, C.R.Revisiting the largest diamond found in the AmericasIgc 30th. Brasil, Aug. abstract only 1p.Brazil, Minas GeraisDiamond - notable President Vargas
DS201112-0959
2011
Souza Filho, C.R.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
DS201112-0734
2010
Souza Gomes, N.Newman, J.A., Teixeira Carvalho de Newman, D., Gandini, A.L., Souza Gomes, N., Krambrock, K.W.H., Pimenta, M.A.Caracterizacao mineralogica dos diamantes policristalinos (carbonados) da regiao de Santa Elena de Uairen, estado Bolivar, Venezuela.5th Brasilian Symposium on Diamond Geology, Nov. 6-12, abstract p. 46-47.South America, VenezuelaCarbonado
DS201809-1992
2018
Souza Saes, G.Babinski, M., McGee, B., do Couto Tokashiki, C., Tassinari, C.C.G., Souza Saes, G., Cavalante Pinho, F.E.Comparing two arms of an orogenic belt during Gondwana amalgamation: age and provenance of Cuiaba Group, northern Paraguay, Brazil.South American Earth Sciences, Vol. 85, pp. 6-42.South America, Brazilgeochronology

Abstract: The Cuiabá Group is the basal part of the sequence of passive margin sediments that unconformably overly the Amazonian Craton in central Brazil. Despite these rock's importance in understanding Brazil's path in the supercontinent cycle from Rodinia to Gondwana and their potential record of catastrophic glaciation their internal stratigraphy and relationship to other units is still poorly understood. The timing of deposition and source areas for the subunits of the Cuiabá Group sedimentary rocks are investigated here using integrated U-Pb and Sm-Nd isotope data. We sampled in the northern Paraguay Belt, a range that developed in response to the collision between the Amazonian Craton, the Rio Apa Block, the São Francisco Craton and the Paranapanema Block. 1125 detrital zircon LA-ICPMS U-Pb ages were calculated and 22 whole rock samples were used for Sm-Nd isotope analysis. The U-Pb ages range between Archean and Neoproterozoic and the main source is the Sunsás Province. Moving up stratigraphy there is a subtle increase in slightly younger detritus with the youngest grain showing an age of 652?±?5 Ma, found at the top of the sequence. The age spectra are similar across each of the sampled units and when combined with the Sm-Nd data, indicate that the source of the detritus was mostly similar throughout deposition. This is consistent with the analysis here that indicates sedimentation occurred in a passive margin environment on the southern margin of the Amazonian Craton. The maximum depositional age of 652?±?5 Ma along with the age of the overlying cap carbonate of the Mirassol d’Oeste Formation suggests that part of this section of sediments were deposited in the purportedly global ?636 Ma Marinoan glaciation, although we give no sedimentological evidence for glaciation in the study area. Compared to the southern Paraguay Belt where no direct age constraints exist, the glacial epoch could be either Cryogenian or Ediacaran. In addition, available data in the literature indicates a diachronous evolution between the northern and southern arms of the Paraguay Belt in the final stages of deposition and deformation.
DS2002-0933
2002
Soyer, W.Leibecker, J., Getzmeier, A., Honig, M., Kuras, O., Soyer, W.Evidence of electrical anisotropic structures in the lower crust and the upper mantleEarth and Planetary Science Letters, Vol. 202, 2, pp. 289-302.EuropeGeophysics - seismics
DS1986-0777
1986
Sozin, Yu.I.Sozin, Yu.I., Nikitin, Yu.I., Poltaeatskii, V.G.Substructure and phase composition of natural diamonds containing lonsdaleite #2Sverkhtverd Material (Russian), No. 4, pp. 12-15RussiaDiamond, Morphology
DS1986-0778
1986
Sozin, Yu.I.Sozin, Yu.I., Nikitin, Yu.I., Poltoratskii, V.G.Substructure and phase composition of natural diamonds containing lonzdaleite #1Soviet Journal of Superhard. Mater, Vol. 8, No. 4, pp. 14-18RussiaNatural diamond
DS1987-0706
1987
Sozin, Yu.I.Sozin, Yu.I., Nikitin, Yu.I., Poltoratskiy, V.G.Natural mosaic diamond single crystals containing lonsdaleite.(Russian)Izmenie Svoistv. Mater. Pod. Deist. Vys. Davl. Kiev., (Russian), pp. 44-8. Khim. Zhur. abstract No. 4E293 1987RussiaBlank
DS201112-0002
2011
Spacek, P.Ackerman, L., Spacek, P., Svojtka, M.Pyroxenite xenoliths from Cenozoic alkaline basalts, Bohemian Massif.Goldschmidt Conference 2011, abstract p.406.Europe, Bohemia, PolandBasanites, Foidites
DS1997-0915
1997
Spada, G.Piromallo, C., Spada, G., Ricard, Y.Sea Level fluctuations due to subduction: the role of mantle rheologyGeophys. Research Letters, Vol. 24, No. 13, July 1, pp. 1587-90MantleSubduction, Sea level
DS2003-0256
2003
Spada, G.Cianetti, S., Giunchi, C., Spada, G.Mantle viscosity beneath the Hudson Bay: an inversion based on the MetropolisJournal of Geophysical Research, Vol. 107, 12, Dec. 6, pp. DO! 10.1029/2001JB000585OntarioGeophysics - seismics
DS200412-0330
2003
Spada, G.Cianetti, S., Giunchi, C., Spada, G.Mantle viscosity beneath the Hudson Bay: an inversion based on the Metropolis algorithm.Journal of Geophysical Research, Vol. 107, 12, Dec. 6, pp. DO! 10.1029/2001 JB000585Canada, OntarioGeophysics - seismics
DS200412-1545
2004
Spada, G.Pians Agostinni, N., Spada, G., Cianetti, S.Mantle viscosity inference: a comparison between simulated annealing and neighbourhood algorithm inversion methods.Geophysical Journal International, Vol. 157, 2, pp. 890-900.MantleGeophysics
DS1999-0096
1999
Spadea, P.Brown, D., Spadea, P.Processes of forearc and accretionary complex formation during arc continent collision in the southern Ural MtnGeology, Vol. 27, No. 7, July pp. 649-52.Russia, UralsCrust - tectonics, collision
DS200712-0116
2006
Spadea, P.Brown, D., Spadea, P., Puchkov, V., Alvarez-Marron, J., Herrington, R., Willner, A.P., Hetzel, R., Gorozhanina, Y., Juhlin, C.Arc continent collision in the southern Urals.Earth Science Reviews, in press availableRussia, UralsBaltica tectonics, UHP, geochemistry
DS1995-1807
1995
Spadini, G.Spadini, G., Bertotti, G., Cloetingh, S.Tectono stratigraphic modelling of the Sardinian margin of the TyrrhenianSea.Tectonophysics, Vol. 252, pp. 269-84.GlobalTectonics
DS200512-1028
2004
Spaggiardi, C.V.Spaggiardi, C.V., Gray, D.R., Foster, D.A.Lachlan Orogen subduction accretion systematics revisited.Australia Journal of Earth Sciences, Vol. 51, 4, pp. 549-553.AustraliaSubduction - not specific to diamonds
DS201412-0144
2014
Spaggiari, R.Coopersmith, H., Toledo, V., Fritsch, E., Ward, J., De Wit, M., Spaggiari, R.Geology and exploration of gem deposits at Mt. Carmel, northern Israel: natural moissanite, sapphire, ruby and diamond.Geological Society of America Conference Vancouver Oct. 19-22, 2p. AbstractEurope, IsraelMoissanite
DS201412-0933
2014
Spaggiari, R.Toledo, V., Ward, J., De Wet, M., Spaggiari, R., Coopersmith, H.Developing a geological model to guide placer exploration in the Kishon catchment, northern Israel.Shefa Yamin Exploration & Mining, 2p. Poster and 1 page abstractEurope, IsraelKishon Placers
DS201505-0248
2015
Spaggiari, R.Toledo, V., Ward, J., de Wit, M., Spaggiari, R., Coopersmith, H., Wald, R.A transient fluvial placer in the mid reach of the Kishon Valley northern Israel: initial results of follow up exploration.Israel Geological Society, 1p.posterEurope, IsraelExploration results
DS201609-1716
2016
Spaggiari, R.De Wit, M., Bhebhe, Z., Davidson, J., Haggerty, S.E., Hundt, P., Jacob, J., Lynn, M., Marshall, T.R., Skinner, C., Smithson, K., Stiefenhofer, J., Robert, M., Revitt, A., Spaggiari, R., Ward, J.Overview of diamonds resources in Africa.Episodes, Vol. 9, 2, pp. 198-238.AfricaDiamond resources - overview

Abstract: From the discovery of diamonds in South Africa in 1866 until the end of 2013, Africa is estimated to have produced almost 3.2 Bct out of a total global production of 5.03 Bct, or 63.6% of all diamonds that have ever been mined. In 2013 African countries ranked 2nd (Botswana), 3rd (DRC), 6th (Zimbabwe), 7th (Angola), 8th (South Africa), and 9th (Namibia), in terms of carat production and 1st (Botswana), 4th (Namibia), 5th (Angola), 6th (South Africa), 7th (Zimbabwe), and 9th (DRC), in terms of value of the diamonds produced. In 2013 Africa produced 70.6 Mct out of a global total of 130.5 Mct or 54.1%, which was valued at US$ 8.7 billion representing 61.5% of the global value of US$ 14.1 billion.
DS200612-1339
2006
Spaggiari, R.I.Spaggiari, R.I., Bluck, B.J., Ward, J.D.Characteristics of Diamondiferous Plio PLeistocene littoral deposits within the palaeo Orange River mouth, Namibia.Ore Geology Reviews, Vol. 28, 4, pp. 475-492.Africa, NamibiaGeomorphology, alluvials, placers, marine
DS202109-1490
2021
Spaggiari, R.I. de WitSpaggiari, R.I. de Wit, M.C.J.Diamondiferous alluvial deposits of the Longatshimo Valley, Kasai Province, southern DRC: a sedimentary and economic model of a central African diamond placer.South African Journal of Geology, Vol. 124, pp. 499-518.Africa, Democratic Republic of Congodeposit - Kasai

Abstract: The Kasai alluvial field in southern Democratic Republic of Congo (DRC) is part of central Africa’s largest diamond placer that has produced more than 200 million carats, mainly derived from Quaternary deposits. A small part of these deposits, along and within the Longatshimo River, is the subject of this study providing a glimpse into the alluvial history of the Kasai diamond placer. This work documents their sedimentological and diamond mineralization attributes, as well as their emplacement processes, which can inform future exploration models. The key controls of this placer formation, notably Quaternary climatic variations, fluvial landscape evolution and bedrock conditions are also evaluated. A consequence of the interplay among these processes is that diamond supply (from Cretaceous alluvial sources), recycling and concentration were most pronounced and consistent, in the Late Quaternary. Alluvial diamond mineralization in this central African region thus evolved differently to those in southern Africa. Based on exploration results in the Longatshimo Valley, diamond concentration improves but diamond size diminishes with decreasing deposit age, and thus the modern river sediments contain the highest abundance but smallest diamonds. This is opposite to the grade and diamond size trend that characterises southern African fluvial diamond placers. The Longatshimo River study offers insight into the Kasai alluvial field, and its placer model is expected to be applicable to the exploration of other central African diamond placers.
DS200712-1136
2007
Spaggiari, S.Ward, J., Spaggiari, S., Kriel, L.Digging in the DRC: shades of Ye olde Kimberley?Diamonds in Kimberley Symposium & Trade Show, Bristow and De Wit held August 23-24, Kimberley, South Africa, GSSA Diamond Workshop CD slides 40Africa, Democratic Republic of CongoHistory, locals! Mbelenge
DS1999-0697
1999
Spaggiori, R.I.Spaggiori, R.I., Ward, J.D., De Wit, M.C.J.Fluvial characteristics of the Diamondiferous Droogeveldt gravels, VaalValley, South Africa.Economic Geology, Vol. 94, No. 5, Aug. pp. 741-48.South AfricaDiamond alluvials, Droogeveldt area
DS1988-0658
1988
Spakman, W.Spakman, W.Upper mantle delay time tomography with an application to the collision zone of the Eurasian, African and Arabian platesGeologica Ultraiectina, No. 53, 200pAfricaGeophysics, Mantle
DS1991-1776
1991
Spakman, W.Van der Hilst, R., Engdahl, R., Spakman, W., Nolet, G.Tomographic imaging of subducted lithosphere below northwest Pacific islandarcsNature, Vol. 353, Septe. 5, pp. 37-43Pacific IslandsMantle, Tectonics
DS1999-0064
1999
Spakman, W.Bijwaard, H., Spakman, W.Tomographic evidence for a narrow whole mantle plume below IcelandEarth and Planetary Science Letters, Vol. 166, No. 3-4, Mar. 15, pp. 121-6.GlobalMantle plume, Hotspot, seismic
DS1999-0760
1999
Spakman, W.Vaan der Voo, R., Spakman, W., Bijwaaard, H.Tehyan subducted slabs under IndiaEarth and Planetary Science Letters, Vol. 171, No. 1, Aug. 15, pp. 7-20.IndiaSubduction - slabs
DS1999-0761
1999
Spakman, W.Vacher, P., Spakman, W., Wortel, M.J.R.Numerical tests on the seismic visibility of metastable minerals at subduction zones.Earth and Planetary Science Letters, Vol. 170, No. 3, Julu. 15, pp. 335-MantleGeophysics - seismics, Mineralogy
DS200412-0765
2004
Spakman, W.Hall,R., Spakman, W.Mantle structure and tectonic evolution of the region north and east of Australia.Hillis, R.R., Muller, R.D. Evolution and dynamics of the Australian Plate, Geological Society America Memoir, No. 372, pp. 361-382.AustraliaTectonics
DS201012-0330
2010
Spakman, W.Jones, A.G., Plomerova, J., Korja, T., Sodoudi, F., Spakman, W.Europe from the bottom up: a statistical examination of the central and northern European lithosphere asthenosphere boundary comparing seismological & EMLithos, in press available, 51p.EuropeGeophysics - seismics
DS201012-0810
2010
Spakman, W.Van der Meer, D.G., Spakman, W., Van Hinsbergen, D.J.J., Amaru, M.L., Torsvik, T.H.Towards absolute plate motions constrained by lower mantle slab remnants.Nature Geoscience, Vol. 3, Jan. pp. 36-40.MantleTectonics, Pangea
DS201606-1116
2016
Spakman, W.Shephard, G.E., Tronnes, R.G., Spakman, W., Panet, I., Gaina, C.Evidence of slab material under Greenland and links to Cretaceous high Arctic magmatism.Geophysical Research Letters, Vol. 43, 8, pp. 3717-3726.Europe, GreenlandMagmatism

Abstract: Understanding the evolution of extinct ocean basins through time and space demands the integration of surface kinematics and mantle dynamics. We explore the existence, origin, and implications of a proposed oceanic slab burial ground under Greenland through a comparison of seismic tomography, slab sinking rates, regional plate reconstructions, and satellite-derived gravity gradients. Our preferred interpretation stipulates that anomalous, fast seismic velocities at 1000-1600?km depth imaged in independent global tomographic models, coupled with gravity gradient perturbations, represent paleo-Arctic oceanic slabs that subducted in the Mesozoic. We suggest a novel connection between slab-related arc mantle and geochemical signatures in some of the tholeiitic and mildly alkaline magmas of the Cretaceous High Arctic Large Igneous Province in the Sverdrup Basin. However, continental crustal contributions are noted in these evolved basaltic rocks. The integration of independent, yet complementary, data sets provides insight into present-day mantle structure, magmatic events, and relict oceans.
DS201607-1293
2016
Spakman, W.Domeier, M., Doubrovine, P.V., Torsvik, T.H., Spakman, W., Bull, A.L.Global correlation of mantle structure and past subduction.Geophysical Research Letters, Vol. 43, 10, pp. 4945-4953.MantleSubduction

Abstract: Advances in global seismic tomography have increasingly motivated identification of subducted lithosphere in Earth’s deep mantle, creating novel opportunities to link plate tectonics and mantle evolution. Chief among those is the quest for a robust subduction reference frame, wherein the mantle assemblage of subducted lithosphere is used to reconstruct past surface tectonics in an absolute framework anchored in the deep Earth. However, the associations heretofore drawn between lower mantle structure and past subduction have been qualitative and conflicting, so the very assumption of a correlation has yet to be quantitatively corroborated. Here we show that a significant, time-depth progressive correlation can be drawn between reconstructed subduction zones of the last 130 Myr and positive S wave velocity anomalies at 600 -2300 km depth, but that further correlation between greater times and depths is not presently demonstrable. This correlation suggests that lower mantle slab sinking rates average between 1.1 and 1.9 cmyr 1.
DS201612-2337
2016
Spakman, W.Shephard, G.E., Tronnes, R.G., Spakman, W., Panet, I., Gaina, C.Evidence for slab material under Greenland and links to Cretaceous high arctic magmatism.Geophysical Research Letters, Vol. 7, 10.1002/ 2016GL068424Europe, GreenlandMagmatism

Abstract: Understanding the evolution of extinct ocean basins through time and space demands the integration of surface kinematics and mantle dynamics. We explore the existence, origin, and implications of a proposed oceanic slab burial ground under Greenland through a comparison of seismic tomography, slab sinking rates, regional plate reconstructions, and satellite-derived gravity gradients. Our preferred interpretation stipulates that anomalous, fast seismic velocities at 1000-1600?km depth imaged in independent global tomographic models, coupled with gravity gradient perturbations, represent paleo-Arctic oceanic slabs that subducted in the Mesozoic. We suggest a novel connection between slab-related arc mantle and geochemical signatures in some of the tholeiitic and mildly alkaline magmas of the Cretaceous High Arctic Large Igneous Province in the Sverdrup Basin. However, continental crustal contributions are noted in these evolved basaltic rocks. The integration of independent, yet complementary, data sets provides insight into present-day mantle structure, magmatic events, and relict oceans.
DS201804-0680
2018
Spakman, W.Chertova, M.V., Spakman, W., Steinberger, B.Mantle flow influence on subduction evolution.Earth and Planteray Science Letters, Vol. 489, pp. 258-266.Mantlesubduction

Abstract: The impact of remotely forced mantle flow on regional subduction evolution is largely unexplored. Here we investigate this by means of 3D thermo-mechanical numerical modeling using a regional modeling domain. We start with simplified models consisting of a 600 km (or 1400 km) wide subducting plate surrounded by other plates. Mantle inflow of ?3 cm/yr is prescribed during 25 Myr of slab evolution on a subset of the domain boundaries while the other side boundaries are open. Our experiments show that the influence of imposed mantle flow on subduction evolution is the least for trench-perpendicular mantle inflow from either the back or front of the slab leading to 10-50 km changes in slab morphology and trench position while no strong slab dip changes were observed, as compared to a reference model with no imposed mantle inflow. In experiments with trench-oblique mantle inflow we notice larger effects of slab bending and slab translation of the order of 100-200 km. Lastly, we investigate how subduction in the western Mediterranean region is influenced by remotely excited mantle flow that is computed by back-advection of a temperature and density model scaled from a global seismic tomography model. After 35 Myr of subduction evolution we find 10-50 km changes in slab position and slab morphology and a slight change in overall slab tilt. Our study shows that remotely forced mantle flow leads to secondary effects on slab evolution as compared to slab buoyancy and plate motion. Still these secondary effects occur on scales, 10-50 km, typical for the large-scale deformation of the overlying crust and thus may still be of large importance for understanding geological evolution.
DS201811-2616
2018
Spakman, W.van der Meer, D.G., van Hinsbergen, D.J.J., Spakman, W.Atlas of the underworld: slab remnants in the mantle, their sinking history, and a new outlook on lower mantle viscosity.Tectonophysics, Vol. 773, 1, pp. 309-448.Mantlegeophysics - seismic

Abstract: Across the entire mantle we interpret 94 positive seismic wave-speed anomalies as subducted lithosphere and associate these slabs with their geological record. We document this as the Atlas of the Underworld, also accessible online at www.atlas-of-the-underworld.org, a compilation comprising subduction systems active in the past ~ 300 Myr. Deeper slabs are correlated to older geological records, assuming no relative horizontal motions between adjacent slabs following break-off, using knowledge of global plate circuits, but without assuming a mantle reference frame. The longest actively subducting slabs identified reach the depth of ~ 2500 km and some slabs have impinged on Large Low Shear Velocity Provinces in the deepest mantle. Anomously fast sinking of some slabs occurs in regions affected by long-term plume rising. We conclude that slab remnants eventually sink from the upper mantle to the core-mantle boundary. The range in subduction-age versus - depth in the lower mantle is largely inherited from the upper mantle history of subduction. We find a significant depth variation in average sinking speed of slabs. At the top of the lower mantle average slab sinking speeds are between 10 and 40 mm/yr, followed by a deceleration to 10-15 mm/yr down to depths around 1600-1700 km. In this interval, in situ time-stationary sinking rates suggest deceleration from 20 to 30 mm/yr to 4-8 mm/yr, increasing to 12-15 mm/yr below 2000 km. This corroborates the existence of a slab deceleration zone but we do not observe long-term (> 60 My) slab stagnation, excluding long-term stagnation due to compositional effects. Conversion of slab sinking profiles to viscosity profiles shows the general trend that mantle viscosity increases in the slab deceleration zone below which viscosity slowly decreases in the deep mantle. This is at variance with most published viscosity profiles that are derived from different observations, but agrees qualitatively with recent viscosity profiles suggested from material experiments.
DS201902-0328
2018
Spakman, W.Van der Meer, D.G., van Hinsbergen, D.J.J., Spakman, W.Atlas of the underworld: slab remnants in the mantle, their sinking history, and a new outlook on lower mantle viscosity.Tectonophysics, Vol. 723, 1, pp. 309-448.Mantlesubduction

Abstract: Across the entire mantle we interpret 94 positive seismic wave-speed anomalies as subducted lithosphere and associate these slabs with their geological record. We document this as the Atlas of the Underworld, also accessible online at www.atlas-of-the-underworld.org, a compilation comprising subduction systems active in the past ~ 300 Myr. Deeper slabs are correlated to older geological records, assuming no relative horizontal motions between adjacent slabs following break-off, using knowledge of global plate circuits, but without assuming a mantle reference frame. The longest actively subducting slabs identified reach the depth of ~ 2500 km and some slabs have impinged on Large Low Shear Velocity Provinces in the deepest mantle. Anomously fast sinking of some slabs occurs in regions affected by long-term plume rising. We conclude that slab remnants eventually sink from the upper mantle to the core-mantle boundary. The range in subduction-age versus - depth in the lower mantle is largely inherited from the upper mantle history of subduction. We find a significant depth variation in average sinking speed of slabs. At the top of the lower mantle average slab sinking speeds are between 10 and 40 mm/yr, followed by a deceleration to 10-15 mm/yr down to depths around 1600-1700 km. In this interval, in situ time-stationary sinking rates suggest deceleration from 20 to 30 mm/yr to 4-8 mm/yr, increasing to 12-15 mm/yr below 2000 km. This corroborates the existence of a slab deceleration zone but we do not observe long-term (> 60 My) slab stagnation, excluding long-term stagnation due to compositional effects. Conversion of slab sinking profiles to viscosity profiles shows the general trend that mantle viscosity increases in the slab deceleration zone below which viscosity slowly decreases in the deep mantle. This is at variance with most published viscosity profiles that are derived from different observations, but agrees qualitatively with recent viscosity profiles suggested from material experiments.
DS201910-2306
2019
Spakman, W.Van Hinsbergen, D.J.J., Torsvik, T.H., Schmid, S.M., Matenco, L.C., Maffione, M., Vissers, R.L.M., Gurer, D., Spakman, W.Orogenic architecture of the Mediterranean region and kinematic reconstruction of its tectonic evolution since the Triassic. AtriaGondwana Research, in press available 427p.Europecraton

Abstract: The basins and orogens of the Mediterranean region ultimately result from the opening of oceans during the early break-up of Pangea since the Triassic, and their subsequent destruction by subduction accommodating convergence between the African and Eurasian Plates since the Jurassic. The region has been the cradle for the development of geodynamic concepts that link crustal evolution to continental break-up, oceanic and continental subduction, and mantle dynamics in general. The development of such concepts requires a first-order understanding of the kinematic evolution of the region for which a multitude of reconstructions have previously been proposed. In this paper, we use advances made in kinematic restoration software in the last decade with a systematic reconstruction protocol for developing a more quantitative restoration of the Mediterranean region for the last 240 million years. This restoration is constructed for the first time with the GPlates plate reconstruction software and uses a systematic reconstruction protocol that limits input data to marine magnetic anomaly reconstructions of ocean basins, structural geological constraints quantifying timing, direction, and magnitude of tectonic motion, and tests and iterations against paleomagnetic data. This approach leads to a reconstruction that is reproducible, and updatable with future constraints. We first review constraints on the opening history of the Atlantic (and Red Sea) oceans and the Bay of Biscay. We then provide a comprehensive overview of the architecture of the Mediterranean orogens, from the Pyrenees and Betic-Rif orogen in the west to the Caucasus in the east and identify structural geological constraints on tectonic motions. We subsequently analyze a newly constructed database of some 2300 published paleomagnetic sites from the Mediterranean region and test the reconstruction against these constraints. We provide the reconstruction in the form of 12 maps being snapshots from 240 to 0 Ma, outline the main features in each time-slice, and identify differences from previous reconstructions, which are discussed in the final section.
DS1996-1354
1996
Spaletti, L.A.Spaletti, L.A., Salda, L.H. dalla.A pull apart volcanic related Tertiary Basin, an example from the Patagonian AndesJournal of South American Earth Sciences, Vol. 9, No. 3/4, pp. 197-206Peruvolcanism., Tectonics
DS1996-1355
1996
Spalletti, L.A.Spalletti, L.A., Dalla Salda. L.H.A pull apart volcanic related Tertiary basin an example from the PatagonianAndes.Journal of South American Earth Sciences, Vol. 9, No. 3-4, pp. 197-206.Andes, Chile, ArgentinaTectonics - volcanism.
DS2001-0332
2001
Spalletti, L.A.Franzese, J.R., Spalletti, L.A.Late Triassic early Jurassic continental extension in southwestern Gondwana: tectonic segmentation - riftingJournal of South American Earth Sciences, Vol. 14, No. 3, July pp. 257-270.GondwanaTectonics
DS200412-1884
2004
Spandler, C.Spandler,C., Hermann, J., Arculus, R., Mavrogenes, J.Geochemical heterogeneity and element mobility in deeply subducted oceanic crust; insights from high-pressure mafic rocks from NChemical Geology, Vol. 206, 1-2, May 28, pp. 21-42.New CaledoniaSubduction, geochemistry, eclogite
DS200612-1340
2006
Spandler, C.Spandler, C., Hermann, J.High pressure veins in eclogite from New Caledonia and their significance for fluid migration in subduction zones.Lithos, Vol. 89, 1-2, June pp. 135-153.Asia, New CaledoniaGeochemistry, Pouebo Eclogite Melange, subduction
DS201012-0742
2010
Spandler, C.Spandler, C., Petke, T., Hermann, J.Experimental and natural constraints on the composition of UHP metamorphic fluids. Keynote paper.Goldschmidt 2010 abstracts, abstractTechnologyReview - UHP
DS201312-0871
2013
Spandler, C.Spandler, C., Pirard, C.Element recycling from subducting slabs to arc crust: a review.Lithos, Vol. 170-171, pp. 208-223.MantleSubduction
DS201810-2374
2018
Spandler, C.Rosenthal, A., Yaxley, G.M., Crichton, W.A., Kovacs, I.J., Spandler, C., Hermann, J., Sandorne, J.K., Rose-Koga, E., Pelleter, A-A.Phase relations and melting of nominally 'dry' residual eclogites with variable CaO/Na2O from 3 to 5 Gpa and 1250 to 1500C; implications for refertilisation of upwelling heterogeneous mantle. Lithos, Vol. 314-315, pp. 506-519.Mantlemelting
DS201812-2855
2018
Spandler, C.Nazari-Dehkordi, T., Spandler, C., Oliver, N.H.S., Wilson, R.Unconformity related rare earth element deposits: a regional scale hydrothermal mineralization type of Northern Australia.Economic Geology, Vol. 113, 6, pp. 1297-1305.Australia, Northern AustraliaREE

Abstract: Rare earth element (REE) orebodies are typically associated with alkaline igneous rocks or develop as placer or laterite deposits. Here, we describe an economically important heavy (H)REE mineralization type that is entirely hydrothermal in origin with no demonstrable links to magmatism. The mineralization occurs as numerous xenotime-rich vein and breccia orebodies across a large area of northern Australia but particularly close to a regional unconformity between Archean metasedimentary rocks of the Browns Range Metamorphics and overlying Proterozoic sandstones of the Birrindudu Group. The deposits formed at 1.65 to 1.61 Ga along steeply dipping faults; there is no known local igneous activity at this time. Depletion of HREEs in the Browns Range Metamorphics, together with the similar nonradiogenic Nd isotope composition of the orebodies and the Browns Range Metamorphics, indicates that ore metals were leached directly from the Browns Range metasedimentary rocks. We propose an ore genesis model that involves fluid leaching HREEs from the Browns Range Metamorphics and subsequently mixing with P-bearing acidic fluid from the overlying sandstones in fault zones near the unconformity. The union of P and HREEs via fluid mixing in a low-Ca environment triggered extensive xenotime precipitation. This mineralization is unlike that of any other class of REE ore deposit but has a similar setting to unconformity-related U deposits of Australia and Canada, so we assign it the label “unconformity-related REE.” Further discoveries of this REE mineralization type are expected near regional unconformities within Proterozoic intracontinental sedimentary basins across the globe.
DS201901-0077
2018
Spandler, C.Slezak, P., Spandler, C.Ghosts of apatite past: using hyperspectral cathodluminescence and micro-geochemical data to reveal multi-generational apatite in the Gifford Creek carbonatite complex, Australia.The Canadian Mineralogist, Vol. 56, pp. 773-797.Australia, western Australiadeposit - Gifford Creek

Abstract: Apatite can host significant levels of trace elements, including REE, within its crystal lattice, making it particularly useful for deciphering geological events and processes. This study employs hyperspectral cathodoluminescence (CL) and in situ microchemical techniques to identify and characterize various generations of apatite occurring in the phoscorites, carbonatites, and fenites of the Gifford Creek Carbonatite Complex (GCCC), Western Australia. Hyperspectral CL revealed that apatite crystals in all samples have complex internal zoning, including multiple distinct generations, with zones of relatively bright CL generally having more complex spectra compared to darker CL zones. Most of the CL spectra have prominent sharp peaks at ?1.4 eV and ?2.l eV as well as a broad peak between 2.3 eV and 3.5 eV. We relate these different peaks to individual REE activators and groups of activators, in particular Nd3+, Eu3+, Sm3+, and Ce3+. Trace element analyses of apatite confirm the relative enrichment of REE in the CL brighter zones. Most apatite generations exhibit concave-down to sinusoidal REY patterns lacking Eu anomalies, but often feature distinct negative Y anomalies. The depletion in LREE is interpreted to be due to LREE sequestration into monazite, which is relatively abundant in most of the samples. Most apatite samples contain very low Si contents, but appreciable Na, so REE incorporation into apatite was primarily via a coupled substitution of REE + Na replacing 2Ca, which is consistent with the highly alkaline, low SiO2 environment under which the apatite formed. Based on the combined trace-element signatures and CL textures, we interpret the multiple generations of apatite to reflect magmatic growth from alkaline magmas followed by recrystallization during subsequent metamorphic/hydrothermal events. The notable exception is the apatite core domains from a fenite sample that contain relatively high Si and Mn contents, low Sr, and relatively HREE-enriched REY patterns with distinct negative Eu anomalies. This apatite is interpreted to be relict from the granitic precursor to fenitization. The apatite samples also show systematic compositional variations across the GCCC, with apatite from phoscorite samples from the southeast part of the complex containing higher Sr, lower Gd/Ce, and lower ?3 values (normalized REE pattern inflections) compared to apatite from the northwest part of the complex. Recognition of these spatial variations in apatite compositions from the intra-grain micro-scale through to the district scale demonstrates the utility of combining advanced petrographic methods, such as hyperspectral CL, with micro-chemical analysis to reveal complex geological records preserved in apatite. As apatite is a common accessory mineral, these techniques may be more broadly applicable to igneous source tracing, understanding metamorphic and/or metasomatic processes, provenance studies from detrital mineral records, and studies of the evolution of ore systems.
DS201903-0544
2019
Spandler, C.Slezak, P., Spandler, C.Carbonates as recorders of mantle derived magmatism and subsequent tectonic events: an example of the Gifford Creek carbonatite complex, western Australia.Lithos, Vol. 328-329, pp. 212-227.Australia, western Australiadeposit - Gifford Creek

Abstract: The Gifford Creek Carbonatite Complex (GCCC), Western Australia contains a diverse suite of alkaline igneous rocks, including magnesiocarbonatites, ferrocarbonatites, phoscorites, fenites, magmatic-hydrothermal peralkaline dykes, and ironstones. This study employs U-Pb, Sm-Nd, and Lu-Hf radiogenic isotope techniques on monazite - (Ce), fluorapatite, and zircon to determine the origin, age, and history of the GCCC. Zircon crystals found in glimmerite alteration selvages adjacent to ferrocarbonatites exhibit pyramidal crystal morphologies, ?Hf values of ?1.8 to ?4.3, high Th/U, and variable Zr/Hf, all of which are indicative of carbonatitic zircon sourced from an enriched mantle component. Uranium-Pb dating of these zircons returned a definitive magmatic age of ~1370?Ma for the GCCC. Monazite hosted in the ferrocarbonatites, phoscorites, and fenite alteration assemblages yielded variable U-Pb ages ranging from ca. 1250?Ma to 815?Ma. Neodymium isotope isochrons determined from coexisting monazite and apatite gave ages between ca. 1310?Ma to ca. 1190?Ma, but all with similar initial 143Nd/144Nd values of 0.51078-0.51087. The 1370?Ma age of the GCCC does not correspond to any known mantle plume activity, but does broadly correlate with the separation of the North China Craton from the West Australian Craton as part of the greater breakup of Nuna. The monazite and apatite ?Nd data illustrate that the multiple younger U-Pb monazite and Nd isotope isochron ages are not recording multiple magmatic intrusions into the complex, but rather represent partial recrystallisation/resetting of REE-bearing minerals during the protracted tectonic history of the Western Australia Craton from ~1300?Ma to 815?Ma and its involvement in the breakup of Nuna and assembly and disassembly of Rodinia. The age variability in the U-Pb and the Sm-Nd isotope systems in monazite and apatite reveal that tectonically-induced hydrothermalism can contribute to the isotopic resetting of phosphate minerals. This age resetting, if properly identified, can be used as a thorough geochronological record of tectonism affecting alkaline igneous complexes after initial magmatic emplacement.
DS202001-0050
2020
Spandler, C.Yaxley, G.M., Ghosh, S., Kiseeva, E.S., Mallick, A., Spandler, C., Thomson, A.R., Walter, M.J.Co2 rich melts in the earth.IN: Deep Carbon: past to present. Editors Orcutt, Danielle, Dasgupta, pp. 129-162.Mantlemelting

Abstract: This chapter reviews the systematics of partial melting of mantle lithologies - like peridotite and eclogite - in the presence of carbon dioxide. It discusses the composition of mantle-derived magmas generated in the presence of carbon dioxide and whether magmas erupted on Earth’s surface resemble carbonated magmas from the mantle. It reviews how the production of carbon dioxide-rich magma in the mantle varies as a function of tectonic settings - beneath continents and oceans and in subduction zones - and time.
DS202004-0533
2020
Spandler, C.Slezak, P., Spandler, C.Petrogenesis of the Gifford Creek carbonatite complex, western Australia.Contributions to Mineralogy and Petrology, Vol. 175, 28p. Pdf.Australiacarbonatite

Abstract: The 1370 Ma Gifford Creek Carbonatite Complex (GCCC) comprises a diverse suite of alkaline dyke and sill complexes that cover an area of?~?250 km2 in the Gascoyne Province, Western Australia. Most carbonatite types are interpreted to be related products of fractional crystallisation, with calcite carbonatites representing cumulate rocks and dolomite carbonatites representing crystallised products of the derivative liquids. Genetic relationships between these carbonatites and other alkaline igneous units are less clear. The ankerite-siderite carbonatites and magnetite-biotite dykes are likely of related magmatic origin as both have distinctly high LREE and low HFSE contents. The ankerite-siderite carbonatites have mantle-like ?13C isotope values of ? 6.1 to ? 7.1‰ and similar geochemistry to other known magmatic ferrocarbonatites. Silica-rich alkaline veins found near the centre of the complex have trace element signatures that are antithetic to the magnetite-biotite dykes, so these veins are interpreted to represent products of alkali- and F-rich magmatic-hydrothermal fluids exsolved from the magnetite-biotite dykes during their emplacement. Carbon, O, Sr, and Nd isotope data are consistent with an enriched mantle source for the origin of the GCCC, with mantle enrichment likely caused by plate convergence processes associated with the c. 2.0 Ga Glenburgh Orogeny. There is no evidence to link mantle plume activity with formation of the GCCC; rather, alkaline magmatism is interpreted to result from low degree melting of the metasomatised mantle during reactivation of the crustal suture zone at 1370 Ma. The carbonatitic magmas utilised the Lyons River Fault to traverse the crust to be emplaced as the GCCC. Post magmatic alteration has variably modified the O and Sr isotope compositions of carbonates from these rocks. We therefore appeal for careful evaluation of isotopic data from ancient carbonatites, as isotopic resetting may be more common than currently recognised.
DS202007-1180
2020
Spandler, C.Spandler, C., Slezak, P., Nazari-Dehkordi, T.Tectonic significance of Australian rare earth element deposits.Earth Science Reviews, Vol. 207, 103219 16p. PdfAustraliaREE

Abstract: Australia is host to a diverse range of rare earth element (REE) ore deposits, and therefore is well placed to be a major supplier of REE into the future. This paper presents a review of the geology and tectonic setting of Australia's hard-rock REE resources. The deposits can be classified into four groups: 1. Carbonatite associated; 2. Peralkaline/alkaline volcanic associated; 3. Unconformity related, and; 4. Skarns and iron-oxide?copper?gold (IOCG) related. With the exception of the unconformity related deposits, all of these deposit groups are directly or indirectly related to continental alkaline magmatism. Extensive fractional crystallisation and/or igneous accumulation of REE minerals were essential ore-forming processes for carbonatite-associated and peralkaline/alkaline volcanic-associated deposits, while hydrothermal transport and concentration of REE sourced from basement rocks was responsible for producing ore in unconformity-related, skarns and, potentially, IOCG deposits. The economic potential of many deposits has also been enhanced by supergene alteration processes. All of Australia's REE deposits formed in an intracontinental setting in association with crustal-scale fault zones or structures that acted as transport conduits for ore-forming magmas or fluids. Most deposits formed in the Mesoproterozoic under conditions of relative tectonic quiescence. There is little evidence for the involvement of mantle plumes, with the exception of the Cenozoic peralkaline volcanic systems of eastern Australia, and possibly the IOCG deposits. Instead, ore productive magmas were generated by melting of previously-enriched mantle lithosphere in response to disruption of the lithosphere-asthenophere boundary due to fault activation. REE minerals in many deposits also record episodes of recrystallisation/resetting due to far-field effects of orogenic activity that may significantly postdate primary ore formation. Therefore, REE orebodies can be effective recorders of intracontinental deformation events. In general, Australia's inventory of REE deposits is similar to the global record. Globally, the Mesoproterozoic appears to be a particularly productive time period for forming REE orebodies due to favourable conditions for generating ore-fertile magmas and favourable preservation potential due to a general lack of aggressive continental recycling (i.e., active plate tectonics).
DS202105-0790
2021
Spandler, C.Slezak, P., Spandler, C., Border, A., Whittock, K.Geology and ore genesis of the carbonatite-associated Yangibana REE district, Gascoyne Province, Western Australia.Mineralium Deposita, 10.1007/s00126-020-01026-z 20p. PdfAustraliaREE

Abstract: The Yangibana rare earth element (REE) district consists of multiple mineral deposits/prospects hosted within the Mesoproterozoic Gifford Creek Carbonatite Complex (GCCC), Western Australia, which comprises a range of rock types including calcite carbonatite, dolomite carbonatite, ankerite-siderite carbonatite, magnetite-biotite dykes, silica-rich alkaline veins, fenite, glimmerites and what have historically been called “ironstones”. The dykes/sills were emplaced during a period of extension and/or transtension, likely utilising existing structures. The Yangibana REE deposits/prospects are located along many of these structures, particularly along the prominent Bald Hill Lineament. The primary ore mineral at Yangibana is monazite, which is contained within ankerite-siderite carbonatite, magnetite-biotite dykes and ironstone units. The ironstones comprise boxwork-textured Fe oxides/hydroxides, quartz, chalcedony and minor monazite and subordinate rhabdophane. Carbonate mineral-shaped cavities in ironstone, fenite and glimmerite alteration mantling the ironstone units, and ankerite-siderite carbonatite dykes altering to ironstone-like assemblages in drill core indicate that the ironstones are derived from ankerite-siderite carbonatite. This premise is further supported by similar bulk-rock Nd isotope composition of ironstone and other alkaline igneous rocks of the GCCC. Mass balance evaluation shows that the ironstones can be derived from the ankerite-siderite carbonatites via significant mass removal, which has resulted in passive REE concentration by ~?2 to ~?10 times. This mass removal and ore tenor upgrade is attributed to extensive carbonate breakdown and weathering of ankerite-siderite carbonatite by near-surface meteoric water. Monazite from the ironstones has strong positive and negative correlations between Pr and Nd, and Nd and La, respectively. These relationships are reflected in the bulk-rock drill assays, which display substantial variation in the La/Nd throughout the GCCC. The changes in La/Nd are attributed to variations in primary magmatic composition, shifts in the magmatic-hydrothermal systems related to CO2 versus water-dominated fluid phases, and changes in temperature.
DS200712-0910
2007
Spandler, C.S.Rosenthal, A., Yaxley, G.M., Green, D.H., Hermann, J., Spandler, C.S.Phase and melting relations of a residual garnet clinopyroxenite.Plates, Plumes, and Paradigms, 1p. abstract p. A851.MantleMelting
DS200712-1202
2007
Spandler, C.S.Yaxley, G.M., Spandler, C.S., Green, D.H., Rosenthal, A., Brey, G.P.The influence of minor elements on melting of eclogite in the mantle.Plates, Plumes, and Paradigms, 1p. abstract p. A1143.MantleMelting
DS200812-0972
2008
Spandler, C.S.Rosenthal, A., Yaxley, G.M., Green, D.H., Hermann, J., Spandler, C.S.Melting of residual eclogites with variable proportions of quartz coesite.Goldschmidt Conference 2008, Abstract p.A806.TechnologyMagma genesis
DS200912-0838
2009
Spandler, C.S.Yaxley, G.M., Spandler, C.S., Sobolev, A.V., Rosenthal, A., Green, D.H.Melting and melt peridotite interactions in heterogeneous upper mantle sources of primitive volcanics.Goldschmidt Conference 2009, p. A1482 Abstract.MantleMelting
DS201012-0638
2010
Spandler, C.S.Rosenthal, A., Yaxley, G.M., Green, D.H., Hermann, J., Spandler, C.S., Kovacs, I., Mernagh, T.P.Phase and melting relations of a residual eclogite within an upwelling heterogeneous upper mantle.International Mineralogical Association meeting August Budapest, abstract p. 156.MantlePetrogenesis
DS201212-0599
2012
Spandler, C.S.Rosenthall, A., Yaxley, G.M., Green, D.H., Kovacs, I., Herman, J., Spandler, C.S., Mernagh, T.P.Phase and melting relations of a residue eclogite/pyroxenite within an upwelling heterogeneous upper mantle.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractMantleMelting
DS200612-0114
2006
Spangenberg, J.Beeskow, B., Treloar, P.J., Rankin, A.H., Vennemann, T.W., Spangenberg, J.A reassessment of models for hydrocarbon generation in the Khibiny nepheline syenite complex, Kola Peninsula, Russia.Lithos, in press availableRussiaAlkalic
DS200712-1024
2006
Spar, D.L.Spar, D.L.Continuity and change in the international diamond market.Journal of Economic Perspectives, Brief Review of:, Vol. 20, 3, pp.195-208. Gems & Gemology Spring 07 p.93GlobalHistory
DS1993-0137
1993
Spark, R.N.Borradaile, G.J., erner, T., Dehls, J.F., Spark, R.N.Archean regional transpression and paleomagnetism in northwestern CanadaTectonophysics, Vol. 220, No. 1-4, April 15, pp. 117-126OntarioGeophysics, Paleomagnetism
DS1994-0922
1994
Spark, R.N.Kjarsgaard, B.A., Spark, R.N., Jakop, Z.J.Preliminary geology Kaola 76D/10Geological Survey of Canada (GSC) Open File, No. 2966, map, 1: 50, 000Northwest TerritoriesGeology
DS1994-0923
1994
Spark, R.N.Kjarsgaard, B.A., Spark, R.N., Jakop, Z.J.Geology, Ursula Lake 76D/16Geological Survey of Canada (GSC) Open File, No. 2967, map, 1: 50, 000Northwest TerritoriesGeology
DS1994-0924
1994
Spark, R.N.Kjarsgaard, B.A., Spark, R.N., Jakop, Z.J.Preliminary geology Koala District of MackenzieGeological Survey of Canada Open file Map., No. 2966, 1: 50, 000 $ 19.75Northwest TerritoriesGeology map, Koala area
DS1994-0925
1994
Spark, R.N.Kjarsgaard, B.A., Spark, R.N., Jakop, Z.J.Preliminary geology Ursula Lake District of MackenzieGeological Survey of Canada Open file Map., No. 2967, 1: 50, 000 $ 19.75Northwest TerritoriesGeology map, Ursula Lake area
DS1999-0364
1999
Spark, R.N.Kjarsgaard, B.A., Jakop, Z.J., Spark, R.N.Preliminary geology, Exeter Lake 76D/15Geological Survey of Canada (GSC) Open File, No. 3702, map, 1: 50, 000Northwest TerritoriesGeology
DS200512-0541
2005
Spark, R.N.Kjarsgaard, B.A., Spark, R.N., Jakop, Z.J.Preliminary geology Koala district of Mackenzie Northwest Territories. Map 76 D 10.Geological Survey of Canada Open File, OF 2966 $ 21.00Canada, Northwest TerritoriesGeology map
DS200512-0542
2005
Spark, R.N.Kjarsgaard, B.A., Spark, R.N., Jakop, Z.J.Preliminary geology Ursula Lake district of Mackenzie Northwest Territories. Map 76 D 16.Geological Survey of Canada Open File, OF 2967 $ 21.00Canada, Northwest TerritoriesGeology map
DS201607-1315
2016
Sparkman< W.Shephard, G.E., Tronnes, R.G., Sparkman< W., Panet, I., Gaina, C.Evidence for slab material under Greenland and links to Cretaceous High Arctic magmatism.Geophysical Research Letters, Vol. 43, 8, pp. 3717-3726.Europe, GreenlandMagmatism

Abstract: Understanding the evolution of extinct ocean basins through time and space demands the integration of surface kinematics and mantle dynamics. We explore the existence, origin, and implications of a proposed oceanic slab burial ground under Greenland through a comparison of seismic tomography, slab sinking rates, regional plate reconstructions, and satellite-derived gravity gradients. Our preferred interpretation stipulates that anomalous, fast seismic velocities at 1000 -1600?km depth imaged in independent global tomographic models, coupled with gravity gradient perturbations, represent paleo-Arctic oceanic slabs that subducted in the Mesozoic. We suggest a novel connection between slab-related arc mantle and geochemical signatures in some of the tholeiitic and mildly alkaline magmas of the Cretaceous High Arctic Large Igneous Province in the Sverdrup Basin. However, continental crustal contributions are noted in these evolved basaltic rocks. The integration of independent, yet complementary, data sets provides insight into present-day mantle structure, magmatic events, and relict oceans.
DS1998-0002
1998
Sparks, D.Abbott, D., Mooney, W., Sparks, D.Growth rate of early continents from two parameters: crustal thickness and depleted mantle thickness.Geological Society of America (GSA) Annual Meeting, abstract. only, p.A207.MantleArchean
DS2000-0001
2000
Sparks, D.Abbott, D., Sparks, D., Herzberg, C., Mooney, W., et al.Quantifying Precambrian crustal extraction: the root is the answerTectonophysics, Vol. 322, No. 1-2, pp.163-90.MantleTectonics - root
DS200512-0164
2005
Sparks, D.Cheadle, M.J., Sparks, D.Komatiites and the temperature of the mantle ' some like it hot'.Chapman Conference held in Scotland August 28-Sept. 1 2005, 1p. abstractMantleMantle plume, geothermometry
DS1991-1643
1991
Sparks, D.W.Sparks, D.W., Parmentier, E.M.Melt extraction from the mantle beneath spreading centersEarth and Planetary Science Letters, Vol. 105, pp. 368-377GlobalMantle, Melt migration
DS1993-1516
1993
Sparks, D.W.Sparks, D.W., Parmentier, E.M., Morgan, J.P.Three dimensional mantle convection beneath a segmented spreading center:implications along axis variations in crustal thickness.Journal of Geophysical Research, Vol. 98, No. B 12, Dec.10, pp. 21, 977-995.MantleConvection, Crust thickness, gravity
DS1992-0814
1992
Sparks, G.Kajner, L., Sparks, G.Quantifying the value of flexibility when conducting stochastic mine investment analysisThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin), Vol. 85, No. 964, October pp. 68-71GlobalEconomics, ore reserves, Suspending operations -limit losses
DS200912-0362
2009
Sparks, R.J.Kavanagh, J.L., Sparks, R.J.A thermodynamic model to describe temperature changes during kimberlite ascent.GAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyTechnologyGeothermometry
DS200612-1341
2006
Sparks, R.J.S.Sparks, R.J.S., Baker, L., Brown, R.J., Field, M., Schumacher, J., Stripp, G., Walters, A.Dynamical constraints on kimberlite volcanism.Journal of Volcanology and Geothermal Research, in press availableAfrica, South AfricaGeodynamics, eruptions, diamonds, models, fluidization
DS200912-0130
2009
Sparks, R.J.S.Costa, A., Sparks, R.J.S., Macedonio, G., melnik, O.Effects of wall rock elasticity on magma flow in dykes during explosive eruptions.Earth and Planetary Science Letters, Vol. 288, 3-4, pp. 455-462.MantleMagmatism - not specific to diamonds
DS1993-1517
1993
Sparks, R.S.Sparks, R.S., Huppert, H.E., et al.Origin of model and rythmic igneous layering by sedimentation in aconvecting magma chamberNature, Vol. 361, No. 6409, January 21, pp. 246-248GlobalMagma, Layered intrusion
DS1993-1518
1993
Sparks, R.S.Sparks, R.S., Huppert, Koyaguchi, HallworthOrigin of modal and rhthmic igneous layering by sedimentation in aconvecting magma chamber.Nature, Vol. 361, Jan. 21, pp. 246-8.GlobalMagmatism - convection
DS2002-0047
2002
Sparks, R.S.Annen, C., Sparks, R.S.Effects of repetitive emplacement of basaltic intrusions on thermal evolution and melt generation in the crust.Earth and Planetary Science Letters, Vol. 203, 3-4, pp. 937-55.MantleMelting - heat flow
DS200812-1100
2007
Sparks, R.S.Sparks, R.S., Brown, R.J., Field, M., Gilbertson, M.Kimberlite ascent and eruption.Nature, Vol. 450, 7172, p. E21.TechnologyClassification
DS200912-0249
2009
Sparks, R.S.Gernon, T.M., Sparks, R.S., Field, M., Ogilvie-Harris, R.C.Geological constraints on the emplacement of the Snap lake kimberlite dyke, NW Territories, Arctic Canada.GAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyCanada, Northwest TerritoriesDeposit - Snap Lake
DS200912-0363
2009
Sparks, R.S.Kavanagh, J.L., Sparks, R.S.Temperature changes in ascending kimberlite magma.Earth and Planetary Science Letters, Vol. 286, 3-4, pp. 404-413.MantleMagmatism, geothermometry
DS200912-0547
2009
Sparks, R.S.Ogilvie-Harris, R.C., Sparks, R.S., Field, M., Gernon, T.M.The geochemistry of the Snap Lake kimberlite dyke, Northwest Territories: phlogopite and spinel.GAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyCanada, Northwest TerritoriesDeposit - Snap Lake
DS201912-2819
2019
Sparks, R.S.Russell, J.K., Sparks, R.S., Kavanagh, G.M.Kimberlites volcanology: transport, ascent and eruption.Elements, Vol. 15, 6, pp.Mantlediamond genesis
DS1989-0671
1989
Sparks, R.S.J.Huppert, H.E., Sparks, R.S.J.Chilled margins in igneous rocksEarth and Planetary Science Letters, Vol. 92, pp. 397-405. Database # 17826GlobalRock classification
DS1989-1436
1989
Sparks, R.S.J.Sparks, R.S.J.In situ differentiation in magmaNature, Vol. 340, No. 6230, July 20, p. 187GlobalMagma, Layered intrusion
DS1990-1399
1990
Sparks, R.S.J.Sparks, R.S.J.Crystal capture, sorting and retention in convectingmagma: discussion andreplyGeological Society of America (GSA) Bulletin, Vol. 102, No. 6, June pp. 847-848GlobalMagma, Volcanic petrology
DS1991-1644
1991
Sparks, R.S.J.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
DS1993-0621
1993
Sparks, R.S.J.Hallworth, M.A., Phillips, J.C., Huppert, H.E., Sparks, R.S.J.Entrainment in turbulent gravity currentsNature, Vol. 362, No. 6423, April 29, pp. 829-830GlobalSedimentation
DS1998-0510
1998
Sparks, R.S.J.Gilbert, J.S., Sparks, R.S.J.Future research directions on the physics of explosive volcanic eruptionsGilbert and Sparks, Geological Society of London, No. 145, pp. 1-7.GlobalVolcanic processes - not specific to diamonds
DS1998-0983
1998
Sparks, R.S.J.McLeod, P., Sparks, R.S.J.The dynamics of xenolith assimilationContributions to Mineralogy and Petrology, Vol. 132, No. 1, pp. 21-33.MantleXenoliths
DS1998-1387
1998
Sparks, R.S.J.Sparks, R.S.J., Bursik, Carey. Gilbert, GlazeVolcanic plumesJohn Wiley, 570pGlobalBook - table of contents, volcanism, fluid dynamics, eruptions
DS1998-1388
1998
Sparks, R.S.J.Sparks, R.S.J., Gilbert, J.S.The physics of explosive volcanic eruptionsGeological Society of London Spec. Pub, No. 145, 192p. $ 98.00GlobalBook - ad, Magma, flow, fragmentation, phretomagmatic
DS1999-0698
1999
Sparks, R.S.J.Sparks, R.S.J., Tait, S.R., Yanev, Y.Dense welding caused by volatile resorptionJournal of Geological Society of London, Vol. 156, No. 2, Mar. pp. 217-26.GlobalMagmatism - volconology
DS200612-0029
2006
Sparks, R.S.J.Annen, C., Blundy, J.D., Sparks, R.S.J.The genesis of intermediate and silicic magmas in deep crustal hot zones.Journal of Petrology, Vol. 47, 3, pp. 505-539.MantleMagmatism - not specific to diamonds
DS200612-0184
2006
Sparks, R.S.J.Brown, R.J., Tait, M., Field, M., Sparks, R.S.J.Progressive enlargement and infill of a kimberlite pipe: K2 pipe, Venetia kimberlite field, Limpopo Province, South Africa.Emplacement Workshop held September, 5p. extended abstractAfrica, South AfricaDeposit - K2, Venetia - lithofacies assemblages
DS200612-0447
2006
Sparks, R.S.J.Gernon, T.M., Gilbertson, M.A., Sparks, R.S.J., Walters, A., Field, M.Gas solid fluidisation in an experimental tapered bed: insights into processes in diverging volcanic conduits.Emplacement Workshop held September, 5p. extended abstractTechnologyFluidisation, emplacement
DS200612-0448
2006
Sparks, R.S.J.Gernon, T.M., Sparks, R.S.J., Brown, R.J., Field, M.Gas segregation pipes in kimberlite: evidence for fluidisation at Orapa south pipe, Botswana.Emplacement Workshop held September, 5p. extended abstractAfrica, BotswanaDeposit - Orapa - fluidisation, structure
DS200612-0670
2006
Sparks, R.S.J.Kavanagh, J.L., Menand, T., Sparks, R.S.J.An experimental investigation of sill formation and propogation in layered elastic media.Emplacement Workshop held September, 1p. abstractGlobalDynamics - sill intrusion
DS200612-1342
2006
Sparks, R.S.J.Sparks, R.S.J., Baker, Brooker, Brown, Field, Fontana, Gernon, Kavanagh, Shumacher, Stripp, Walter, Walters, White, WindsorDynamical constraints on kimberlite volcanism,Emplacement Workshop held September, 5p. abstractGlobalMagmatism, water, stages
DS200612-1388
2006
Sparks, R.S.J.Stripp, G.R., Field, M., Schumacher, J.C., Sparks, R.S.J., Cressey, G.Post emplacement serpentinization and related hydrothermal metamorphism in a kimberlite from Venetia, South Africa.Journal of Metamorphic Geology, Vol. 24, 6, August pp. 515-534.Africa, South AfricaMetamorphism - deposit - Venetia
DS200612-1389
2006
Sparks, R.S.J.Stripp, G.R., Field, M., Schumacher, J.C., Sparks, R.S.J., Cressy, G.Post emplacement serpentinization and related hydrothermal metamorphism in a kimberlite from Venetia, South Africa.Emplacement Workshop held September, 5p. abstractAfrica, South AfricaDeposit - Venetia, petrography, alteration
DS200612-1505
2006
Sparks, R.S.J.Walters, A.L., Phillips, J.C., Brown, R.J., Field, M., Gernon, T., Stripp, G., Sparks, R.S.J.The role of fluidisation in the formation of volcaniclastic kimberlite: grain size observations and experimental investigation.Journal of Volcanology and Geothermal Research, in press availableAfrica, South AfricaDeposit - Venetia, explosive eruption, fluidization
DS200712-0119
2007
Sparks, R.S.J.Brown, R.J., Kavanagh, J., Sparks, R.S.J., Tait, M., Field, M.Mechanically disrupted and chemically weakened zones in segmented dike system cause vent localization: evidence from kimberlite volcanic systems.Geology, Vol. 35, 9, pp. 815-818.Africa, South AfricaDeposit - Swartruggems dike swarm
DS200812-0145
2008
Sparks, R.S.J.Brown, R.J., Buse, B., Sparks, R.S.J., Field, M.On the welding of pyroclasts from very low viscosity magmas: examples from kimberlite volcanoes. Venetia K2, BK9 Damtshaa (Orapa)Journal of Geology, Vol. 117, pp. 354-374.Africa, South Africa, BotswanaClassification - coherent kimberlite
DS200812-0146
2008
Sparks, R.S.J.Brown, R.J., Field, M., Gernon, T., Gilbertson, M., Sparks, R.S.J.Problems with in vent column collapse model for the emplacement of massive volcaniclastic kimberlite. Discussion of Porritt - Fox kimberliteJournal of Volcanology and Geothermal Research, in press available 8p.Canada, Northwest territoriesFox kimberlite petrology
DS200812-0148
2009
Sparks, R.S.J.Brown, R.J., Tait, M., Field, M., Sparks, R.S.J.Geology of a complex kimberlite pipe ( K2 pipe), Venetia Mine, South Africa: insights into conduit processes during explosive ultrabasic eruptions.Bulletin Volcanology, Vol. 71, 1, pp. 95-112.Africa, South AfricaDeposit - Venetia
DS200812-0397
2008
Sparks, R.S.J.Gernon, T.M., Gilbertson, M.A., Sparks, R.S.J., Field, M.Gas fluidization in an experimental tapered bed: insights into processes in diverging volcanic conduits.Journal of Volcanology and Geothermal Research, Vol. 174, 1-3, pp. 49-56.TechnologyEmplacement, diatreme
DS200812-0398
2008
Sparks, R.S.J.Gernon, T.M., Sparks, R.S.J., Field, M.Degassing structures in volcaniclastic kimberlite: examples from southern African kimberlite pipes.Journal of Volcanology and Geothermal Research, Vol. 174, 1-3, pp. 186-194.Africa, South AfricaFluidisation,pyroclastic flows, Orapa. Venetia. Letseng
DS200912-0218
2009
Sparks, R.S.J.Field, M., Gernon, T.M., Mock, A., Walters, A., Sparks, R.S.J., Jerram, D.A.Variations of olivine abundance and grain size in the Snap lake kimberlite intrusion, Northwest Territories, Canada: a possible proxy for diamonds.Lithos, In press available 13p.Canada, Northwest TerritoriesDeposit - Snap Lake
DS200912-0247
2009
Sparks, R.S.J.Gernon, T.M., Fontana, G., Field, M., Sparks, R.S.J., Brown, R.J., Niocaill, C.M.Pyroclastic flow deposits from a kimberlite eruption: the Orapa south crater, Botswana.Lithos, In press available 13p.Africa, BotswanaDeposit - Orapa
DS200912-0248
2009
Sparks, R.S.J.Gernon, T.M., Gilbertson, M.A., Sparks, R.S.J., Field, M.The role of gas fluidization in the formation of massive volcanoclastic kimberlite.Lithos, In press available 33p.MantleFluidization
DS200912-0719
2009
Sparks, R.S.J.Sparks, R.S.J., Brooker, R.A., Field, M., Kavanagh, J., Schumacher, J.C., Walter, M.J., White, J.The nature of erupting kimberlite melts.Lithos, In press available, 30p.MantleMelting
DS201012-0083
2010
Sparks, R.S.J.Buse, B., Schumacher, J.C., Sparks, R.S.J., Field, M.Growth of bultfontenite and hydrogarnet in metasomatized basalt xenoliths in the B/K9 kimberlite, Damtshaa: insights into hydrothermal metamorphism pipeContributions to Mineralogy and Petrology, Vol. 160, 4, pp. 533-550.Africa, BotswanaMetamorphism - BK9
DS201012-0170
2010
Sparks, R.S.J.Doyle, E.E., Hogg, A.J., Mader, H.M., Sparks, R.S.J.A two layer model for the evolution and propogation of dense and dilute regions of pyroclastic currents.Journal of Volcanology and Geothermal Research, Vol. 190, 3-4, pp. 365-378.TechnologyVolcanism
DS201012-0546
2009
Sparks, R.S.J.Ogilvie-Harris, R.C., Field, M., Sparks, R.S.J., Walter, M.J.Perovskite from the Dutoitspan kimberlite, Kimberley, South Africa: implications for magmatic processes.Mineralogical Magazine, Vol. 73, no. 6, pp. 915-928.Africa, South AfricaDeposit - Dutoitspan
DS201112-0115
2011
Sparks, R.S.J.Brooker, R.A., Sparks, R.S.J., Kavanagh, J.L., Field, M.The volatile content of hypabyssal kimberlite magmas: some constraints from experiments on natural rock compositions.Bulletin Volcanology, in press available 23p.Canada, Nunavut, Northwest Territories, Africa, South AfricaDeposit - Jericho, Lac de Gras
DS201112-0130
2011
Sparks, R.S.J.Buse, B., Sparks, R.S.J., Field, M., Schumacher, J.C., Chisi, K., Thaodi, T.Geology of the BK9 kimberlite ( Damtshaa, Botswana): implications for the formation of dark volcaniclastic kimberlite.Bulletin Volcanology, In press available, 17p.Africa, BotswanaGeology - Damtshaa
DS201112-0210
2011
Sparks, R.S.J.Costa, A., Gottsman, J., Melnik, O., Sparks, R.S.J.A stress controlled mechanism for the intensity of very large magnitude explosive eruptions.Earth and Planetary Science Letters, Vol. 310, 1-2, pp. 161-166.MantleDyke fed eruptions - column collapse
DS201112-0331
2011
Sparks, R.S.J.Fontana, G., Niocaill, C.M., Brown, R.J., Sparks, R.S.J., Field, M.Emplacement temperatures of pyroclastic and volcaniclastic deposits in kimberlite pipes in southern Africa.Bulletin Volcanology, In press available, 21p.Africa, South Africa, BotswanaPaleomagnetism
DS201112-0507
2011
Sparks, R.S.J.Kavanagh, J.L., Sparks, R.S.J.Insights of dyke emplacement mechanics from detailed 3D dyke thickness datasets.Journal of the Geological Society, Vol. 168, pp. 965-978.MantleGeodynamics - not specific to diamonds
DS201112-0508
2011
Sparks, R.S.J.Kavanagh, J.L., Sparks, R.S.J.Insights of dyke emplacement mechanics from detailed 3D dyke thickness datasets.Journal of the Geological Society, Vol. 168, pp. 965-978.Africa, South AfricaSwartruggens, Star, Helam, Muil, Main, Changehouse
DS201112-0914
2011
Sparks, R.S.J.Sarkar, C., Storey, C.D., Hawkesworth, C.J., Sparks, R.S.J.Degassing in kimberlite: oxygen isotope ratios in perovskites from explosive and hypabyssal kimberlites.Earth and Planetary Science Letters, Vol. 312, 3-4, pp. 291-299.Africa, Botswana, South AfricaDeposit - Orapa, Wesselton
DS201112-0915
2011
Sparks, R.S.J.Sarkar, C., Storey, C.D., Hawkesworth, C.J., Sparks, R.S.J.Oxygen isotopes in perovskites from kimberlites.Goldschmidt Conference 2011, abstract p.1798.Africa, Botswana, South AfricaOrapa, Wesselton
DS201212-0091
2012
Sparks, R.S.J.Brown, R.J., Buisman, M.I., Fontana, G., Field, M., Mac Niocaill, C., Sparks, R.S.J., Stuart, F.M.Eruption of kimberlite magmas: physical volcanology, geomorphology and age of the youngest kimberlitic volcanoes known on Earth ( the Upper Pleistocene/Holocene Igwisi Hills volcanoes, Tanzania).Bulletin Volcanology, in press availableAfrica, TanzaniaDeposit - Igwisi
DS201212-0092
2012
Sparks, R.S.J.Brown, R.J., Manya, S., Buisman, I., Fontana, G., Field, M., MacNiocaill, C., Sparks, R.S.J., Stuart, F.M.Eruption of kimberlite magmas: physical volcanology, geomrphology and age of the youngest kimberlitic volcanoes known on Earth ( the Upper Pleistocene-Holocene Igwisi Hills, volcanoes, Tanzania.Bulletin of Volcanology, Vol. 74, 7, pp. 1621-1643.Africa, TanzaniaIgwisi Hills
DS201212-0093
2012
Sparks, R.S.J.Brown, R.J., Manya, S., Buisman, I., Sparks, R.S.J., Field, M., Stuart, F.M., Fontana, G.Physical volcanology, geomorphology, and cosmogenic 3HE dating of the youngest kimberlite volcanoes on Earth ( The Holocene Igwisi Hills, Volcanoes, Tanzania.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractAfrica, TanzaniaIgwisi Hills - geochronology
DS201212-0095
2012
Sparks, R.S.J.Buisman, I., Sparks, R.S.J., Walter, M.J., Brown, R.J., Manya, S., Kavanagh, J.Olivine chemistry of exceptionally young ( Holocene) kimberlite of the Igwisi Hills volcano, Tanzania.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractAfrica, TanzaniaDeposit - Igwisi
DS201212-0235
2012
Sparks, R.S.J.Gernon, T.M., Field, M., Sparks, R.S.J.Geology of the Snap Lake kimberlite intrusion, NWT, Canada: field observations and their interpretation.Journal of the Geological Society, Vol. 169, pp. 1-16.Canada, Northwest TerritoriesDeposit - Snap Lake
DS201212-0236
2012
Sparks, R.S.J.Gernon, T.M.I., Ogilvie-Harris, R.C., Sparks, R.S.J.,Field, M.Emplacement of the Snap Lake kimberlite intrusion, Northwest Territories, Canada.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractCanada, Northwest TerritoriesDeposit - Snap Lake
DS201212-0529
2012
Sparks, R.S.J.Ogilvie-Harris, R.C., Field, M., Brooker, R.A., Walter, M.J., Sparks, R.S.J.The petrology of AK6, Botswana: implications of volcanic and igneous processes.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractAfrica, BotswanaDeposit - AK6
DS201212-0530
2012
Sparks, R.S.J.Ogily-Harris, R.C., Brooker, R.A., Sparks, R.S.J., Walter, M.J.An experimental investigation of the carbonatite-kimberlite melt.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractAfrica, South AfricaDeposit - Dutoitspan
DS201212-0623
2012
Sparks, R.S.J.Sarkar, C., Storey, C.D., Hawkesworth, C.J., Sparks, R.S.J.Trace element nd isotope geochemistry of perovskite from kimberlites of southern Africa.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractAfrica, South AfricaGeochemistry
DS201212-0687
2012
Sparks, R.S.J.Solano, J.M.S., Jackson, M.D., Sparks, R.S.J., Blundy, J.D., Annen, C.Melt segregation in deep crustal hot zones: a mechanism for chemical differentiation, crustal assimilation and the formation of evolved magmas.Journal of Petrology, Vol. 53, 10, pp. 1999-2026.MantleHotspots, magmatism
DS201212-0693
2013
Sparks, R.S.J.Sparks, R.S.J.Kimberlite volcanism.Annual Review of Earth and Planetary Sciences, Vol. 41, available April 2013MantleVolcanism
DS201212-0694
2012
Sparks, R.S.J.Sparks, R.S.J., Buisman, I., Brooker, R., Brown, R.J., Field, M., Gernon, T., Kavanagh,J., Ogilvie-Harris, R., Schumacher, J.C.Dynamics of kimberlite magam ascent, intrusion and eruption.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractGlobalDiamond genesis
DS201212-0772
2012
Sparks, R.S.J.White, J.L., Sparks, R.S.J., Bailey, K., Barnett, W.P., Field, M., Windsor, L.Kimberlite sills and dykes associated with the Wesselton kimberlite pipe, Kimberley, South Africa.South African Journal of Geology, Vol. 115, 1, pp. 1-32.Africa, South AfricaDeposit - Wesselton
DS201312-0129
2013
Sparks, R.S.J.Cashman, K.V., Sparks, R.S.J.How volcanoes work: a 25 year perspective.Geological Society of America Bulletin, Vol. 125, pp. 664-690.GlobalVolcanoes - review
DS201412-0079
2014
Sparks, R.S.J.Buisman, I., Sparks, R.S.J., Brown, R., Manya, S.Microanalysis of olivine chemistry of exceptionally young kimberlite of the Igwisi Hills, volcano, Tanzania.Volcanic and Magmatic Studies Group meeting, Poster Held Jan. 6-8. See minsoc websiteAfrica, TanzaniaIgwisi
DS201704-0648
2017
Sparks, R.S.J.Sparks, R.S.J., Cashman, K.V.Dynamic magma systems: implications for forecasting volcanic activity.Elements, Vol. 13, 1, pp. 35-40.MantleMagmatism

Abstract: Magma systems that supply volcanoes can extend throughout the crust and consist of mush (melt within a crystalline framework) together with ephemeral magma accumulations. Within a crystal-rich mush, slow processes of melt segregation and heat loss alternate with fast processes of destablisation and magma transport. Magma chambers form by two mechanisms: incremental magma intrusion into sub-solidus rocks or the segregation and rapid merging of melt-rich layers within mush regions. Three volcanic states reflect alternations of slow and fast processes: dormancy, unrest and eruption. Monitoring needs to detect processes of melt and fluid movements in the lower and middle crust during destabilisation to improve forecasting.
DS201901-0042
2018
Sparks, R.S.J.Jackson, M.D., Blundy, J., Sparks, R.S.J. Chemical differentiation, cold storage and remobilization of magma in the Earth's crust.Nature, Vol. 564, pp. 405-409.Mantlemagmatism

Abstract: The formation, storage and chemical differentiation of magma in the Earth’s crust is of fundamental importance in igneous geology and volcanology. Recent data are challenging the high-melt-fraction ‘magma chamber’ paradigm that has underpinned models of crustal magmatism for over a century, suggesting instead that magma is normally stored in low-melt-fraction "mush reservoirs". A mush reservoir comprises a porous and permeable framework of closely packed crystals with melt present in the pore space1,10. However, many common features of crustal magmatism have not yet been explained by either the ‘chamber’ or ‘mush reservoir’ concepts. Here we show that reactive melt flow is a critical, but hitherto neglected, process in crustal mush reservoirs, caused by buoyant melt percolating upwards through, and reacting with, the crystals. Reactive melt flow in mush reservoirs produces the low-crystallinity, chemically differentiated (silicic) magmas that ascend to form shallower intrusions or erupt to the surface. These magmas can host much older crystals, stored at low and even sub-solidus temperatures, consistent with crystal chemistry data. Changes in local bulk composition caused by reactive melt flow, rather than large increases in temperature, produce the rapid increase in melt fraction that remobilizes these cool- or cold-stored crystals. Reactive flow can also produce bimodality in magma compositions sourced from mid- to lower-crustal reservoirs. Trace-element profiles generated by reactive flow are similar to those observed in a well studied reservoir now exposed at the surface. We propose that magma storage and differentiation primarily occurs by reactive melt flow in long-lived mush reservoirs, rather than by the commonly invoked process of fractional crystallization in magma chambers.
DS202202-0217
2022
Sparks, R.S.J.Sparks, R.S.J., Blundym J.D., Cashman, K.V., Jackson, M., Rust, A., Wilson, C.J.N.Large silicic magma bodies and very large magnitude explosive eruptions. *** not specific to diamondsBulletin of Volcanology, Vol. 84, 8, 6p. PdfMantlemagmatism

Abstract: Over the last 20 years, new concepts have emerged into understanding the processes that lead to build up to large silicic explosive eruptions based on integration of geophysical, geochemical, petrological, geochronological and dynamical modelling. Silicic melts are generated within magma systems extending throughout the crust by segregation from mushy zones. Segregated melt layers become unstable and can assemble into ephemeral upper crustal magma chambers rapidly prior to eruption. In the next 10 years, we can expect major advances in dynamical models as well as in analytical and geophysical methods, which need to be underpinned in field research.
DS200912-0082
2009
Sparks, S.Buisman, I., Sparks, S., Walker, M.Towards a better understanding of the origin and evolution of kimberlite melts using melt phase relations in CMAS-CO2-H2O-K2O.Goldschmidt Conference 2009, p. A172 Abstract.MantleMelting
DS200912-0083
2008
Sparks, S.Buisman, I., Sparks, S., Walter, M.The origin and evolution of kimberlite melts: stabilizing phlogopite in the CMAS-CO2-H2O-K2O system.American Geological Union, Fall meeting Dec. 15-19, Eos Trans. Vol. 89, no. 53, meeting supplement, 1p. abstractMantleMelting
DS201012-0663
2010
Sparks, S.Sarkar, C., Storey, C., Hawkesworth, C., Sparks, S., Field, M.Fingerprinting of kimberlite sources by isotope studies of accessory minerals: a mantle tracer.Goldschmidt 2010 abstracts, P. 553. abstractTechnologyGeochronology, perovskites
DS1996-0434
1996
Sparks, S.J.Ernst, G.G.J., Sparks, S.J.Sedimentation from turbulent jets and plumesJournal of Geophysical Research, Vol. 101, No. B 3, March 10, pp. 5575-90GlobalSedimentology, Plumes
DS200912-0246
2009
Sparks, S.J.Gernon, T.M., Field, M., Sparks, S.J.Depositional processes in a kimberlite crater: the Upper Cretaceous Orapa South pipe.(Botswana).Sedimentology, Vol. 56, 3, pp. 623-643.Africa, BotswanaGeology - pyroclastic flow
DS200912-0091
2009
Sparks, S.R.Buse, B., Sparks, S.R., Field, M.Growth of Bultfonteinite and hydrogarnet in metasomatized basalt xenoliths in the BK9 kimberlite, Orapa, Botswana: insights and hydrothermal metamorphism in kimberlite pipes.GAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyAfrica, BotswanaDeposit - Orapa
DS200912-0224
2009
Sparks, S.R.Fontana, G.P.,MacNiocaill, C., Brown, R.J., Sparks, S.R., Field, M., Gernon, T.M.Emplacement temperatures of pyroclastic and colcaniclastic deposits in kimberlite pipes in southern Africa: new constraints from paleomagnetic measurementsGAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyAfrica, Botswana, South AfricaDeposit - AK1, Orapa, K1, K2 Venetia
DS200912-0720
2009
Sparks, S.R.Sparks, S.R., Booker, R., Field, M., Kavanagh, J.Volatiles in kimberlite magmas: experimental constraints.GAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyTechnologyMelting
DS1990-0400
1990
Sparlin, M.A.Deri, C.P., Sparlin, M.A.Salt dome seismic profiling from the inside outThe Leading Edge of Exploration, Vol. 9, No. 8, August pp. 22-26GlobalGeophysics- seismics, Review -practical/ salt d
DS202110-1616
2021
Sparta, D.Griffin, W.L., Gain, S.E.M., Saunders, M., Camara, F., Bindi, L., Sparta, D., Toledo, V., O'Reilly, S.Y.Cr203 in corundum: ultrahigh contents under reducing conditions. American Mineralogist, Vol. 106, pp. 1420-1437. pdfEurope, Israeldeposit - Mount Carmel

Abstract: Xenocrysts and xenoliths in Upper Cretaceous pyroclastics on Mount Carmel (northern Israel) represent a series of similar magma-fluid systems at different stages of their evolution, recording a continuous decrease in oxygen fugacity (fO2) as crystallization proceeded. Corundum coexisting with Fe-Mg-Cr-Al spinels, other Fe-Mg-Al-Na oxides, and Fe-Ni alloys in apparent cumulates crystallized at fO2 values near the iron-wüstite (IW) buffer (fO2 = IW±1) and is zoned from high-Cr cores to lower-Cr rims, consistent with fractional crystallization trends. The reconstructed parental melts of the cumulates are Al-Cr-Fe-Mg oxides with ca. 2 wt% SiO2. Corundum in other possible cumulates that contain Cr-Fe (Fe 45 wt%) alloys has low-Cr cores and still lower-Cr rims. Corundum coexisting with Cr0 (fO2 = IW-5) in some possible cumulates has low-Cr cores, but high-Cr rims (to >30% Cr2O3). These changes in zoning patterns reflect the strong decrease in the melting point of Cr2O3, relative to Al2O3, with decreasing fO2. The electron energy loss spectroscopy (EELS) analyses show that all Cr in corundum that coexists with Cr0 is present as Cr3+. This suggests that late in the evolution of these reduced melts, Cr2+ has disproportionated via the reaction 3Cr2+(melt) ? 2Cr3+(Crn) + Cr0. The most Cr-rich corundum crystallized together with ?-alumina phases including NaAl11O17 (diaoyudaoite) and KAl11O17 (kahlenbergite) and ??-alumina phases; residual melts crystallized a range of (K,Mg)2(Al,Cr)10O17 phases with the kahlenbergite structure. The parental melts of these assemblages appear to have been Al-Cr-K-Na-Mg oxides, which may be related to the Al-Cr-Fe-Mg oxide melts mentioned above, through fractional crystallization or liquid immiscibility. These samples are less reduced (fO2 from IW to IW-5) than the assemblages of the trapped silicate melts in the more abundant xenoliths of corundum aggregates (fO2 = IW-6 to IW-10). They could be considered to represent an earlier stage in the fO2 evolution of an “ideal” Mt. Carmel magmatic system, in which mafic or syenitic magmas were fluxed by mantle-derived CH4+H2 fluids. This is a newly recognized step in the evolution of the Mt. Carmel assemblages and helps to understand element partitioning under highly reducing conditions.
DS1989-0461
1989
Spasennykh, M. Yu.Galimov, E.M., Botkunov, A.I., Garanin, V.K., Spasennykh, M. Yu.Carbon-containing fluid inclusions in garnet and olivine from Kimberlites of the Udachnaya pipe. (USSR)(Russian)Geochemistry International (Geokhimiya), (Russian), No. 7, pp. 1011-1015RussiaFluid inclusions, Garnet
DS200812-0677
2008
Spasojevi, S.Liu, L., Spasojevi, S., Gurnis, M.Reconstructing Farallon plate subduction beneath North America back to the late Cretaceous.Science, Vol. 322, 5903, Nov. 7, pp. 934-937.United States, CanadaSubduction
DS1997-1090
1997
Spassov, E.Spassov, E., Kennett, B., Weekes, J.Seismogenic zoning of southeast AustraliaAustralian Journal of Earth Sciences, Vol. 44, pp. 527-534AustraliaGeophysics - seismics, Zones
DS2001-0338
2001
Spath, A.Frimmel, H.E., Zartman, R.E., Spath, A.The Richtersveld igneous complex: uranium-lead (U-Pb) zircon and geochemical evidence for beginning Neoproterozoic...Journal of Geology, Vol. 109, pp. 493-508.South AfricaContinental breakup, Geotectonics
DS2001-0664
2001
Spath, A.Le Roex, A.P., Spath, A., Zartman, R.E.Lithospheric thickness beneath the southern Kenya Rift: implications from basalt geochemistry.Contributions to Mineralogy and Petrology, Vol. 142, No. 1, Oct. pp.89-106.Kenya, southern AfricaGeochemistry - basalt
DS2001-1108
2001
Spath, A.Spath, A., Le Roex, A.P., Opiyo-Akech, N.Plume lithosphere interaction and the origin of continental rift related alkaline volcanism - ChyluluJournal of Petrology, Vol. 42, No. 4, Apr. pp. 765-88.Kenyavolcanism, hot spots, alkaline rocks, Chylulu Hills Volcanic Province
DS1988-0659
1988
Speak, K.E.Speak, K.E., Frenklach, M., Badzian, A., Badzian, T.Vapor deposition of crystalline diamondCeram. Eng. Sci.Proc, Vol. 9, No. 9-10, pp. 1095-1102GlobalDiamond coating, CVD.
DS1989-1437
1989
Spear, F.S.Spear, F.S., Menard, T.Program GIBBS: a generalized Gibbs method algorithMAmerican Mineralogist, Vol. 74, No. 7 and 8, July-August pp. 942-943GlobalComputer, Program - GIBBS
DS1991-1645
1991
Spear, F.S.Spear, F.S., Peacock, S.M., Kohn, M.J., Florence, F.P., Menard, T.Computer programs for petrologic P-T-t path calculationsAmerican Mineralogist, Vol. 76, No. 11, 12 November-December pp. 2009-2012GlobalComputer, Program -petrologic P-T-t
DS1993-1519
1993
Spear, F.S.Spear, F.S.Metamorphic phase equilibration temperatures and pressure-temperature time pathsMineralogical Society of America Monograph, 824p. approx. $ 37.00GlobalBook -ad, Metamorphic petrology
DS201412-0874
2014
Spear, F.S.Spear, F.S., Thomas, J.B., Hallett, B.W.Overstepping the garnet isograd: a comparison of QuiG barometry and thermodynamic modeling quartz in garnet isocrhon.Contributions to Mineralogy and Petrology, Vol. 168, pp. 1059 -United States, VermontGarnet ( not specfic to diamond)
DS1987-0707
1987
Spear, K.E.Spear, K.E.Growth of crystalline diamond from low pressure gasesEarth and Mineral Sciences, Vol. 56, No. 4, Summer pp. 53-59GlobalBlank
DS1989-1438
1989
Spear, K.E.Spear, K.E.Diamond - ceramic coating of the futureJournal of American Ceram. Soc, Vol. 72, No. 2, pp. 171-191GlobalDiamond Application, CVD.
DS1989-1439
1989
Spear, K.E.Spear, K.E.Thermodynamics of CVD diamond growth (meeting abstract.)abstract Pap. ACS, 197 (Apr.) 38-Fuel April 9, 1989, ASCA No. #T5776GlobalDiamond morphology, CVD.
DS1989-1440
1989
Spear, K.E.Spear, K.E.Chemical and energetic aspects of CVD diamond growthAmerican Chem. Soc. Div. Preprint, Vol. 34, No. 2, pp. 436-443GlobalDiamond synthesis, CVD.
DS1982-0149
1982
Spear, P.M.Collins, A.T., Spear, P.M.Optically Active Nickel in Synthetic DiamondJournal of Physics, Sect. D. Applied Physics, Vol. 15, No. 12, PP. L183-L187.GlobalSynthetic Diamond, Geochemistry, Spectra Absorption
DS1986-0147
1986
Spear, P.M.Collins, A.T., Spear, P.M.Optical studies of the 5RL center in diamondJournal of Phys. C., Vol. 19, No. 34, December pp. 6845-6858GlobalMineralogy, Diamond
DS1986-0342
1986
Spear, P.M.Harris, J.W., Spear, P.M.Systematic studies of nitrogen in diamonds from known sourcesProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 398-400South Africa, Botswana, AustraliaDiamond morphology
DS1989-0349
1989
Spear, P.M.Deines, P., Harris, J.W., Spear, P.M., Gurney, J.J.Nitrogen and C-13 content of Finsch and Premier diamonds and theirimplicationsGeochimica et Cosmochimica Acta, Vol. 53, No. 6, June pp. 1367-1378South AfricaDiamond morphology, Diamond inclusions
DS1996-1522
1996
Spear, P.M.Welbourn, C.M., Cooper, M., Spear, P.M.De Beers natural versus synthetic diamond verification instrumentsGems and Gemology, Vol. 32, fall pp. 156-169.GlobalDiamonds - synthetic, Technology - instruments
DS1992-1229
1992
Special IssuePrecambrian Research, Special IssuePrecambrian metallogeny related to plate tectonicsPrecambrian Research, Special Issue, Vol. 58, 450pGlobalMetallogeny, Plate tectonics, areas of interest
DS200612-0257
2006
Speciale, S.Clar, S.M., Speciale, S., Jeanloz, R., Kunz, M., Caldwell, W.A., Walter, M., Walker, D.Using advanced accelerators to understand the lower mantle and beyond.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 104, abstract only.MantleGeochemistry
DS201312-0540
2013
Speciale, S.Lin, J-F., Speciale, S., Mao, Z., Marquardt, H.Effects of the electronic spin transitions of iron in lower mantle minerals: implications for deep mantle geophysics and geochemistry.Reviews of Geophysics, Vol. 51, 2, pp. 244-275.MantleMineralogy
DS202011-2061
2020
Speciale, S.Speciale, S., Censi, P., Gomes, C., Marques, L.Carbonatites from the southern Brazilian platform: a review. II: isotopic evidences.Open Geosciences ( researchgate), 26p. PdfSouth America, Brazilcarbonatite

Abstract: Early and Late Cretaceous alkaline and alkaline-carbonatitic complexes from southern Brazil are located along the main tectonic lineaments of the South America Platform. Calcium-, magnesium-, and ferrocarbonatites are well represented and frequently associated even in the same complex. Primary carbonates present significant variations in C-O isotopic compositions, which are mainly due to isotope exchange with H2O-CO2-rich hydrothermal fluids, whereas fractional crystallization or liquid immiscibility probably affects the ?18O and ?13C values by no more than 2?‰ Our isotope exchange model implies that the most significant isotopic variations took place in a hydrothermal environment, e.g., in the range 400-80°C, involving fluids with the CO2/H2O ratio ranging from 0.8 to 1. Sr-Nd-Pb isotope systematics highlight heterogeneous mixtures between HIMU and EMI mantle components, similar to the associated alkaline rocks and the flood tholeiites from southern Brazil. In spite of the strong variation shown by C-O isotopes, Sr-Nd-Pb-Os isotopic systematics could be related to an isotopically enriched source where the chemical heterogeneities reflect a depleted mantle "metasomatized" by small-volume melts and fluids rich in incompatible elements. These fluids are expected to have promoted crystallization of K-rich phases in the mantle, which produced a veined network variously enriched in LILE and LREE. The newly formed veins (enriched component) and peridotite matrix (depleted component) underwent a different isotopic evolution with time as reflected by the carbonatites. These conclusions may be extended to the whole Paraná-Etendeka system, where isotopically distinct parent magmas were generated following two main enrichment events of the subcontinental lithospheric mantle at 2.0-1.4 and 1.0-0.5?Ga, respectively, as also supported by Re-Os systematics. The mantle sources preserved the isotopic heterogeneities over a long time, suggesting a nonconvective lithospheric mantle beneath different cratons or intercratonic regions. Overall, the data indicate that the alkaline-carbonatitic magmatism originated from a locally heterogeneous subcontinental mantle.
DS202205-0689
2022
Speciale, S.Immoor, J., Miyagi, L., Liemann, H-P., Speciale, S., Schulze, K., Buchen, J., Kumosov, A., Marquardt, H.Weak cubic CaSiO3 perovskite in the Earth's mantle.Nature, Vol. 603, pp. 276-279.Mantlesubduction

Abstract: Cubic CaSiO3 perovskite is a major phase in subducted oceanic crust, where it forms at a depth of about 550?kilometres from majoritic garnet1,2,28. However, its rheological properties at temperatures and pressures typical of the lower mantle are poorly known. Here we measured the plastic strength of cubic CaSiO3 perovskite at pressure and temperature conditions typical for a subducting slab up to a depth of about 1,200?kilometres. In contrast to tetragonal CaSiO3, previously investigated at room temperature3,4, we find that cubic CaSiO3 perovskite is a comparably weak phase at the temperatures of the lower mantle. We find that its strength and viscosity are substantially lower than that of bridgmanite and ferropericlase, possibly making cubic CaSiO3 perovskite the weakest lower-mantle phase. Our findings suggest that cubic CaSiO3 perovskite governs the dynamics of subducting slabs. Weak CaSiO3 perovskite further provides a mechanism to separate subducted oceanic crust from the underlying mantle. Depending on the depth of the separation, basaltic crust could accumulate at the boundary between the upper and lower mantle, where cubic CaSiO3 perovskite may contribute to the seismically observed regions of low shear-wave velocities in the uppermost lower mantle5,6, or sink to the core-mantle boundary and explain the seismic anomalies associated with large low-shear-velocity provinces beneath Africa and the Pacific.
DS1987-0708
1987
Specius, Z.Specius, Z., Bulanova, G.P.Native iron in Diamondiferous eclogites from the Udachnayakimberlitepipe.(Russian)Doklady Academy of Sciences Nauk. SSSR, (Russian), Vol. 294, No. 6, pp. 1445-1448RussiaEclogite, Xenolith
DS1995-2153
1995
Specius, Z.V.Zinchuk, N.N., Specius, Z.V., Zuev, V.M., Romanov, N.N.The experience of mineralogic petrographic mapping of kimberlite pipesProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 698-699.Russia, YakutiaPetrography, Deposit -Mir, Udachnaya
DS1991-1646
1991
Speckman, W.S.Speckman, W.S.MSTRACK: a computerized tracking system for manuscripts written in Paradox for the IBM PC and compatiblesUnited States Geological Survey (USGS) Open File, No. 91-0443-A, B, 50p. disc, $ 13.50 totalGlobalComputer, Program -MSTRACK
DS1995-1808
1995
Spector, A.Spector, A., Lawler, T.L.Application of aeromagnetic dat a to mineral potential evaluation inMinnesotaGeophysics, Vol. 60, No. 6, Nov. Dec. pp. 1704-1714MinnesotaGeophysics, Metallogeny
DS2003-1235
2003
Specuzza, M.J.Schultz, D.J., Valley, J.W., Specuzza, M.J., Channer, D.M.Oxygen isotope composition of eclogitic and peridotitic garnet xenocrysts from the LaInternational Geology Review, Vol. 45, No. 11, Nov. pp. 968-75.VenezuelaGeochronology
DS200412-1769
2003
Specuzza, M.J.Schulze, D.J., Valley, J.W., Specuzza, M.J., Channer, D.M.Oxygen isotope composition of eclogitic and peridotitic garnet xenocrysts from the La Ceniza kimberlite, Guaniamo, Venezuela.International Geology Review, Vol. 45, no. 11, Nov. pp. 968-75.South America, VenezuelaGeochronology
DS1994-1669
1994
Speece, M.A.Speece, M.A., Frost, B.R., Smithson, S.B.Precambrian basement structure and Laramide deformation revealed by seismic reflection profiling in the Laramie Mountains, Wyoming.Tectonics, Vol. 13, No. 2, Apr. pp. 354-66.WyomingTectonics - structure, Diapir - geophysics - seismics
DS1991-1517
1991
Speed, A.A.Schneiders, B.R., Smyk, M.C., Speed, A.A.Field trip Guidebook for the Nipigon-Marathon areaOntario Geological Survey Open File, No. 5763, 55pOntarioAlkaline rocks, Coldwell Complex
DS1991-1518
1991
Speed, A.A.Schneiders, B.R., Smyk, M.C., Speed, A.A.Field trip guidebook to the Nipigon-Marathon areaOntario Geological Survey Open File, No. 5763, 55pOntarioDiatremes, Guidebook
DS1992-1316
1992
Speed, R.C.Russo, R.M., Speed, R.C.Oblique collision and tectonic wedging of the South American continent and Caribbean terranesGeology, Vol. 20, No. 5, May pp. 447-450CaribbeanTectonics, Geophysics -gravity
DS1993-1418
1993
Speed, R.C.Sellock, R.L., Ortega-Gutierrez, F., Speed, R.C.Tectonostratigraphic terranes and tectonic evolution of MexicoGeological Society of America Special Paper, No. 278, 150p. approx. $ 50.00MexicoBook -table of contents, Tectonics
DS1994-1503
1994
Speed, R.C.Russo, R.M., Speed, R.C.Spectral analysis of gravity anomalies and the architecture of tectonicwedging, northeast Venezuela, TrinidadTectonics, Vol. 13, No. 3, June pp. 613-622Venezuela, TrinidadGeophysics -gravity, Tectonics
DS201810-2378
2018
Speelmanns, I.M.Speelmanns, I.M., Schmidt, M.W., Liebske, C.Nitrogen solubility in core materials.Geophysical Research Letters, Vol. 45, 15, pp. 7434-7443. doi.org/10.1029/ 2018GLO79130Mantlenitrogen

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

Abstract: Nitrogen is a key constituent of our atmosphere and forms the basis of life, but its early distribution between Earth reservoirs is not well constrained. We investigate nitrogen partitioning between metal and silicate melts over a wide range of conditions relevant for core segregation during Earth accretion, i.e. 1250-2000 °C, 1.5-5.5 GPa and oxygen fugacities of ?IW-5.9 to ?IW-1.4 (in log units relative to the iron-wüstite buffer). At 1250 °C, 1.5 GPa, ranges from 14 ± 0.1 at ?IW-1.4 to 2.0 ± 0.2 at ?IW-5, N partitioning into the core forming metal. Increasing pressure has no effect on , while increasing temperature dramatically lowers to 0.5 ± 0.15 at ?IW-4. During early core formation N was hence mildly incompatible in the metal. The partitioning data are then parameterised as a function of temperature and oxygen fugacity and used to model the evolution of N within the two early prevailing reservoirs: the silicate magma ocean and the core. Depending on the oxidation state during accretion, N either behaves lithophile or siderophile. For the most widely favoured initially reduced Earth accretion scenario, N behaves lithophile with a bulk partition coefficient of 0.17 to 1.4, leading to 500-700 ppm N in closed-system core formation models. However, core formation from a magma ocean is very likely accompanied by magma ocean degassing, the core would thus contain ?100 ppm of N, and hence, does not constitute the missing N reservoir. Bulk Earth N would thus be 34-180 ppm in the absence of other suitable reservoirs, >98% N of the chondritic N have hence been lost during accretion.
DS200412-0582
2003
Spegaard, H.Friborg, T., Spegaard, H., Christensen, TR., Lloyd, C.R., Panikov, N.S.Siberian wetlands: where a sink is a source.Geophysical Research Letters, Vol. 30, 21, Nov. 1, 10.1029/2003 GLO17797RussiaGeophysics
DS201611-2123
2016
Speich, L.Kohn, S.C., Speich, L., Smith, C.B., Bulanova, G.P.FTIR thermochronometry of natural diamonds: a closer look.Lithos, in press available 34p.Africa, Zimbabwe, Australia, South America, BrazilDeposit - Murowa, Argyle, Machado River

Abstract: Fourier Transform Infrared (FTIR) spectroscopy is a commonly-used technique for investigating diamonds, that gives the most useful information if spatially-resolved measurements are used. In this paper we discuss the best way to acquire and present FTIR data from diamonds, using examples from Murowa (Zimbabwe), Argyle (Australia) and Machado River (Brazil). Examples of FTIR core-to-rim line scans, maps with high spatial resolution and maps with high spectral resolution that are fitted to extract the spatial variation of different nitrogen and hydrogen defects are presented. Model mantle residence temperatures are calculated from the concentration of A and B nitrogen-containing defects in the diamonds using known times of annealing in the mantle. A new, two-stage thermal annealing model is presented that better constrains the thermal history of the diamond and that of the mantle lithosphere in which the diamond resided. The effect of heterogeneity within the analysed FTIR volume is quantitatively assessed and errors in model temperatures that can be introduced by studying whole diamonds instead of thin plates are discussed. The spatial distribution of VN3H hydrogen defects associated with the 3107 cm? 1 vibration does not follow the same pattern as nitrogen defects, and an enrichment of VN3H hydrogen at the boundary between pre-existing diamond and diamond overgrowths is observed. There are several possible explanations for this observation including a change in chemical composition of diamond forming fluid during growth or kinetically controlled uptake of hydrogen.
DS201705-0841
2017
Speich, L.Kohn, S., Speich, L., Smith, C., Bulanova, G.Developments in FTIR spectroscopy of diamonds and better constraints on diamond thermal histories.European Geosciences Union General Assembly 2017, Vienna April 23-28, 1p. 16438 AbstractAfrica, Zimbabwe, Australia, South America, BrazilDeposit - Murowa, Argyle, Machado River

Abstract: Fourier Transform Infrared (FTIR) spectroscopy is a commonly-used technique for investigating diamonds. It gives the most useful information if spatially-resolved measurements are used [1]. In this contribution we discuss the best way to acquire and present FTIR data from diamonds, using examples from Murowa (Zimbabwe), Argyle (Australia) and Machado River (Brazil). Examples of FTIR core-to-rim line scans, maps with high spatial resolution and maps with high spectral resolution that are fitted to extract the spatial variation of different nitrogen and hydrogen defects are presented. Model mantle residence temperatures are calculated from the concentration of A and B nitrogen-containing defects in the diamonds using known times of annealing in the mantle. A new, two-stage thermal annealing model is presented that better constrains the thermal history of the diamond and that of the mantle lithosphere in which the diamond resided. The effect of heterogeneity within the analysed FTIR volume is quantitatively assessed and errors in model temperatures that can be introduced by studying whole diamonds instead of thin plates are discussed. The kinetics of platelet growth and degradation will be discussed and the potential for two separate, kinetically-controlled defect reactions to be used to constrain a full thermal history of the diamond will be assessed. [1] Kohn, S.C., Speich, L., Smith, C.B. and Bulanova, G.P., 2016. FTIR thermochronometry of natural diamonds: A closer look.
DS201803-0478
2017
Speich, L.Speich, L., Kohn, S.C., Wirth, R., Bulanova, G.P., Smith, C.B.The relationship between platelet size and the B' infrared peak of natural diamonds revisited. Type 1aLithos, Vol. 278-281, pp. 419-426.Technologydiamond morphology

Abstract: Platelets in diamond are extended planar defects that are thought to be generated during the nitrogen aggregation process in type Ia diamonds. They were subjected to intensive research during the 1980s and 1990s but the techniques used for observation of defects in diamond have improved since that time and new insights can be gained by further study. This study combines high resolution Fourier Transform Infrared (FTIR) analysis, with an emphasis on the main platelet peak, and transmission electron microscopic (TEM) imaging. By performing TEM and FTIR analyses on volumes of diamond that were closely spatially related it is shown that the average platelet diameter, D, follows the relationship D=ax?b where x is the position of the platelet peak in the infrared spectrum, a is a constant and b is the minimum position of the platelet peak. The best fit to the data is obtained if a value of b=1360cm?1 is used, giving a fitted value of a=221. The observed variation in infrared (IR) peak width can also be explained in terms of this relationship. Additionally, platelet morphology was found to vary according to diameter with large platelets being more elongated. The tendency to become more elongated can be described by the empirical equation AR=11.9D+19.6+0.4 where AR is the aspect ratio. Using the relationships established here, it will be possible to study platelet abundance and size as a function of parameters such as nitrogen concentration, nitrogen aggregation and diamond residence time in the mantle. This work therefore will open up new methods for constraining the geological history of diamonds of different parageneses and from different localities.
DS201809-2050
2018
Speich, L.Kohn, S.C., Speich, L., Bulanova, G.P., Smith, C.B., Gress, M.U., Davies, G.R.Modelling the temperature history of mantle lithosphere using FTIR maps of diamonds.Goldschmidt Conference, 1p. AbstractAfrica, Zimbabwe. Australia, Canada, Northwest Territories, South Africa, Botswanadeposit - Murowa, Argyle, Diavik, Venetia, Orapa

Abstract: FTIR maps of diamond plates, cut through the centre of growth, contain abundant information about changing defect concentrations from core to rim. These data can, in principle, be interpreted in terms of the variation in conditions of diamond growth and the temperatures experienced by the diamond during the period of mantle residence between growth and exhumation. Many diamonds show multiple growth zones that can be observed by cathodoluminescence. Importantly, the combination of nitrogen concentration and nitrogen aggregation measured by FTIR can be used to determine whether the growth zones are of similar or very different ages (Kohn et al., 2016). In this study, we use automated fitting of several thousand individual spectra within each FTIR map to define a model temperature for each pixel using the Python program, QUIDDIT. We then use a two-stage aggregation model to constrain potential temperature-time histories for each diamond. To take full advantage of the temperature history recorded by zoned diamonds, radiometric ages of inclusions are required. If the growth ages of each zone and the date of exhumation are well-known, then a model temperature can be calculated for each zone. The combination of zone-specific ages and improved quality and processing of FTIR spectra is able to provide unique new insights into the thermal history of diamondbearing lithospheric mantle. For the first time we will be able to use the N defects in diamonds to work out whether a particular location in the lithosphere has heated or cooled over long periods of geological time. The implications for the mechanism of formation of lithosphere will be discussed. We will illustrate the approach using examples of zoned diamonds from Murowa (Zimbabwe), Argyle (Australia), Diavik (Canada), Venetia (South Africa) and Orapa (Botswana).
DS201904-0781
2018
Speich, L.Speich, L., Kohn, S.C., Bulanova, G.P., Smith, C.B.The behaviour of platelets in natural diamonds and the development of a new mantle thermometer.Contributions to Mineralogy and Petrology, Vol. 173, pp. 39-GlobalFTIR

Abstract: Platelets are one of the most common defects occurring in natural diamonds but their behaviour has not previously been well understood. Recent technical advances, and a much improved understanding of the correct interpretation of the main infrared (IR) feature associated with platelets (Speich et al. 2017), facilitated a systematic study of platelets in 40 natural diamonds. Three different types of platelet behaviour were identified here. Regular diamonds show linear correlations between both B-centre concentrations and platelet density and also between platelet size and platelet density. Irregular diamonds display reduced platelet density due to platelet breakdown, anomalously large or small platelets and a larger platelet size distribution. These features are indicative of high mantle storage temperatures. Finally, a previously unreported category of subregular diamonds is defined. These diamonds experienced low mantle residence temperatures and show smaller than expected platelets. Combining the systematic variation in platelet density with temperatures of mantle storage, determined by nitrogen aggregation, we can demonstrate that platelet degradation proceeds at a predictable rate. Thus, in platelet-bearing diamonds where N aggregation is complete, an estimate of annealing temperature can now be made for the first time.
DS202009-1665
2020
Speich, L.Speich, L., Kohn, S.C.QUIDDIT - a software tool for automated processing of diamond IR spectra.Computers & Geosciences, doi: 10.1016/j.cageo. 2020.104558 available 30p. PdfGlobalQUIDDIT

Abstract: Goal: QUIDDIT (QUantification of Infrared-active Defects in Diamond and Inferred Temperatures) is a novel Python application for fast and automated processing of IR spectra of diamond. It was first developed for the work presented in previous studies (Kohn et al., 2016; Speich et al. 2017 and 2018) and has been used in our lab successfully. The goal of this project is to enhance the software and provide easy access to users in research and industry alike. Read the "Project Log" section for more information.
DS202010-1881
2020
Speich, L.Speich, L., Kohn, S.C.QUIDDIT - Quantification of infrared active defects in diamond and inferred temperatures.Computers and Geosciences, Vol. 144, 7p. PdfGlobalFTIR

Abstract: QUIDDIT is a free Python software-package designed to process Fourier Transform Infrared (FTIR) spectra of diamonds automatically and efficiently. Core capabilities include baseline correction, determination of nitrogen concentration, nitrogen aggregation state and model temperature and fitting of both the 3107 cm-1 and platelet (B’) peaks. These capabilities have allowed the authors to study platelet defects and their relationship to nitrogen aggregation in previous studies. Data visualisation, vital to interpreting and evaluating results, is another key component of the software. QUIDDIT can be applied to single spectra as well as linescan and 2-dimensional map data. Recently, additional features such as manual platelet peak and nitrogen fitting, custom batch peak fitting and two-stage aggregation modelling were made available. QUIDDIT has been used successfully for natural diamonds containing aggregated forms of nitrogen in the past and has since been adapted for the study of diamonds containing C-centres as well.
DS201605-0904
2016
Speich, L. .Speich, L. .Developments in FTIR spectroscopy of diamond ( part 2): the kinetics of platelet growth and degradation as a potential thermochronometer.DCO Edmonton Diamond Workshop, June 8-10TechnologyFTIR spectroscopy
DS201812-2785
2018
Speich, L. SmithBulanova, G.P., Speich, L. Smith, C.B., Gaillou, E., Koln, S.C., Wibberley, E., Chapman, J.G., Howell, D., Davy, A.T.Argyle deposit: The unique nature of Argyle fancy diamonds: internal structure, paragenesis, and reasons for color.Society of Economic Geology Geoscience and Exploration of the Argyle, Bunder, Diavik, and Murowa Diamond Deposits, Special Publication no. 20, pp. 169-190.Australia, western Australiadeposit - Argyle
DS201112-0886
2011
Speigelman, M.Rudge, J.F., Bercovici, D., Speigelman, M.Disequilibrium melting of a two phase multicomponent mantle.Geophysical Journal International, Vol. 184, 2, pp. 699-718.MantleMelting
DS1997-1091
1997
Speight, H.E.Speight, H.E., Soole, P., Wu, X.Development of an integrated automated, terrestrial photogrammetric system for mine mapping, planning..Australian Institute of Mining and Metallurgy (AusIMM) Bulletin, No. 6, Sept, pp. 21-37AustraliaMining, mapping, Safety, GIS, photogrammetry
DS1920-0305
1926
Speight, W.L.Speight, W.L.Life on the Diggings. the Lure of the DiamondDurban: Natal Mercury, Oct. 20TH.South AfricaCurrent Activities
DS1920-0403
1928
Speight, W.L.Speight, W.L.The Tragedy of the Diggings. Economic Aspects of VenturesDurban: Natal Mercury, AUGUST 1ST.South AfricaMineral Economics, Earnings
DS1920-0469
1929
Speight, W.L.Speight, W.L.Digging Up FortunesColonizer., Vol. 34, JANUARY PP. 10-11.South AfricaAlluvial Diamond Placers, Current Activities
DS1920-0470
1929
Speight, W.L.Speight, W.L.On the Diamond DiggingsContemporary Review., Vol. 135, JUNE, PP. 770-776.South AfricaHistory, Current Activities
DS1995-1809
1995
Speilberg, N.Speilberg, N., Anderson, B.D.Seven ideas that shook the universeJohn Wiley, 355p. approx. $ 32.00 United StatesGlobalBook -ad, Astronomy, energy, conservation, symmetry
DS1996-1356
1996
Speilgelman, M.Speilgelman, M.Geochemical consequences of melt transport in 2-D: the sensitivity of trace elements to mantle dynamics.Earth and Planetary Science Letters, Vol. 139, pp. 115-132.MantleGeodynamics, Geochemistry, melting
DS2002-0596
2002
SpenceGorman, D., Clowes, Ellis, Henstock, Spence, KellerDeep probe: imaging the roots of western North AmericaCanadian Journal of Earth Science, Vol.39,3,Mar.pp.375-98., Vol.39,3,Mar.pp.375-98.Alberta, Montana, Colorado, CordilleraGeophysics - seismics, Tectonics
DS2002-0597
2002
SpenceGorman, D., Clowes, Ellis, Henstock, Spence, KellerDeep probe: imaging the roots of western North AmericaCanadian Journal of Earth Science, Vol.39,3,Mar.pp.375-98., Vol.39,3,Mar.pp.375-98.Alberta, Montana, Colorado, CordilleraGeophysics - seismics, Tectonics
DS1985-0639
1985
Spence, A.Spence, A.Shoshonites and Associated Rocks of Central British ColumbiaBritish Columbia Report of Fieldwork, FOR 1984-1, PP. 426-437.Canada, British ColumbiaAlkaline Rocks
DS1990-1400
1990
Spence, D.A.Spence, D.A., Turcotte, D.L.Buoyancy-driven magma fracture: a mechanism for ascent through the lithosphere and the emplacement ofdiamondsJournal of Geophysical Research, Vol. 95, No. B 4, April 10, pp. 5133-5144GlobalDiamond genesis, Magma
DS2000-0280
2000
Spence, G.D.Fallows, S.J., Spence, G.D., Rogers, G.C.Upper crustal velcocity structure of the southwestern Canadian Cordillera from explosion recordings -seismicPure and Applied Geophys., Vol. 158, No. 9, Sept. pp. 1315-36.British Columbia, CordilleraGeophysics - seismics
DS201512-1939
2015
Spence, 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).
DS1990-1401
1990
Spence, J.A.Spence, J.A.Gold exploration in Guyana and VenezuelaThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin), Vol. 83, No. 939, July p. 114. Abstract (PDA)GlobalBrief overview, Diamond activities
DS2001-1109
2001
Spence, K.N.Spence, K.N.Development of Canadian standards and guidelines for valuation of mineral properties- a perspective ..Valmin 01, Mineral Asset Valuation Oct. 25-6th., pp.24-33.CanadaEconomics - methods, Mineral reserves, resources, valuation, exploration
DS201507-0312
2015
Spence, S.Gernon, T.M., Spence, S., Trueman, C.N., Taylor, R.N., Rohling, E., Hatter, S.J., Harding, I.C.Emplacement of Cabezo Maria lamproite volcano (Miocene) SE Spain.Bulletin of Volcanology, Vol. 77, 6, pp. 52-Europe, SpainLamproite
DS2002-0373
2002
Spenceley, J.DeMull, T.J., Spenceley, J., Hickey, P.Batu Hijau: from discovery to productionMining Engineering, Vol.54.4,April,pp.13-24.Indonesia, SumbawaCopper, mining, Deposit - Batu Hijau
DS2002-1127
2002
SpencerNeumann, E.R., WulffPedersen, E., Pearson, SpencerMantle xenoliths from Tenerife: evidence for reactions between mantle peridotites and silicic carbonatite ..Journal of Petrology, Vol.43,5,pp.825-8., Vol.43,5,pp.825-8.Canary IslandsXenoliths, Melting
DS2002-1128
2002
SpencerNeumann, E.R., WulffPedersen, E., Pearson, SpencerMantle xenoliths from Tenerife: evidence for reactions between mantle peridotites and silicic carbonatite ..Journal of Petrology, Vol.43,5,pp.825-8., Vol.43,5,pp.825-8.Canary IslandsXenoliths, Melting
DS1989-1441
1989
Spencer, C.Spencer, C., Green, A., Morel-a-l'Huissier, P.The extension of the Grenville basement beneath the northern Appalachians:results from the Quebec-Maine seismic reflection and refraction surveysTectonics, Vol. 8, No. 4, August pp. 677-696GlobalGeophysics-Seismics, Tectonics
DS1990-1043
1990
Spencer, C.Milkereit, B., Green, A.G., Lee, M.W., Agena, W.F., Spencer, C.Pre- and post stack migration of Glimpce reflection dataTectonophysics, Vol. 174, No. 1/2, March 1, pp. 1-14Ontario, MichiganGeophysics -Seismics, Glimpce
DS1990-1044
1990
Spencer, C.Milkereit, B., Spencer, C.Multiattribute processing of seismic data: application to dip displaysCanadian Journal of Exploration Geophysics, Vol. 26, No. 1-2, December pp. 47-53GlobalGeophysics, Seismics
DS201604-0636
2016
Spencer, C.Thomas, R.J, Spencer, C., Bushi, A.M., Baglow, N., Gerrit de Kock, B., Hortswood, M.S.A., Hollick, L., Jacobs, J., Kajara, S., Kaminhanda, G., Key, R.M., Magana, Z., McCourt, M.W., Momburi, P., Moses, F., Mruma, A., Myamilwa, Y., Roberts, N.M.W., HamisiGeochronology of the centra Tanzania craton and its southern and eastern orogenic margins.Precambrian Research, in press available 57p.Africa, TanzaniaGeochronology

Abstract: Geological mapping and zircon U-Pb/Hf isotope data from 35 samples from the central Tanzania Craton and surrounding orogenic belts to the south and east allow a revised model of Precambrian crustal evolution of this part of East Africa. The geochronology of two studied segments of the craton shows them to be essentially the same, suggesting that they form a contiguous crustal section dominated by granitoid plutons. The oldest orthogneisses are dated at ca. 2820 Ma (Dodoma Suite) and the youngest alkaline syenite plutons at ca. 2610 Ma (Singida Suite). Plutonism was interrupted by a period of deposition of volcano-sedimentary rocks metamorphosed to greenschist facies, directly dated by a pyroclastic metavolcanic rock which gave an age of ca. 2725 Ma. This is supported by detrital zircons from psammitic metasedimentary rocks, which indicate a maximum depositional age of ca. 2740 Ma, with additional detrital sources 2820 and 2940 Ma. Thus, 200 Ma of episodic magmatism in this part of the Tanzania Craton was punctuated by a period of uplift, exhumation, erosion and clastic sedimentation/volcanism, followed by burial and renewed granitic to syenitic magmatism. In eastern Tanzania (Handeni block), in the heart of the East African Orogen, all the dated orthogneisses and charnockites (apart from those of the overthrust Neoproterozoic granulite nappes), have Neoarchaean protolith ages within a narrow range between 2710 and 2630 Ma, identical to (but more restricted than) the ages of the Singida Suite. They show evidence of Ediacaran "Pan-African" isotopic disturbance, but this is poorly defined. In contrast, granulite samples from the Wami Complex nappe were dated at ca. 605 and ca. 675 Ma, coeval with previous dates of the "Eastern Granulites" of eastern Tanzania and granulite nappes of adjacent NE Mozambique. To the south of the Tanzania Craton, samples of orthogneiss from the northern part of the Lupa area were dated at ca. 2730 Ma and clearly belong to the Tanzania Craton. However, granitoid samples from the southern part of the Lupa "block" have Palaeoproterozoic (Ubendian) intrusive ages of ca. 1920 Ma. Outcrops further south, at the northern tip of Lake Malawi, mark the SE continuation of the Ubendian belt, albeit with slightly younger ages of igneous rocks (ca. 1870-1900 Ma) which provide a link with the Ponte Messuli Complex, along strike to the SE in northern Mozambique. In SW Tanzania, rocks from the Mgazini area gave Ubendian protolith ages of ca. 1980-1800 Ma, but these rocks underwent Late Mesoproterozoic high-grade metamorphism between 1015 and 1040 Ma. One granitoid gave a crystallisation age of ca. 1080 Ma correlating with known Mesoproterozoic crust to the east in SE Tanzania and NE Mozambique. However, while the crust in the Mgazini area was clearly one of original Ubendian age, reworked and intruded by granitoids at ca. 1 Ga, the crust of SE Tanzania is a mixed Mesoproterozoic terrane and a continuation from NE Mozambique. Hence the Mgazini area lies at the edge of the Ubendian belt which was re-worked during the Mesoproterozoic orogen (South Irumide belt), providing a further constraint on the distribution of ca. 1 Ga crust in SE Africa. Hf data from near-concordant analyses of detrital zircons from a sample from the Tanzania Craton lie along a Pb-loss trajectory (Lu/Hf = 0), extending back to ?3.9 Ga. This probably represents the initial depleted mantle extraction event of the cratonic core. Furthermore, the Hf data from all igneous samples, regardless of age, from the entire study area (including the Neoproterozoic granulite nappes) show a shallow evolution trend (Lu/Hf = 0.028) extending back to the same mantle extraction age. This implies the entire Tanzanian crust sampled in this study represents over 3.5 billion years of crustal reworking from a single crustal reservoir and that the innermost core of the Tanzanian Craton that was subsequently reworked was composed of a very depleted, mafic source with a very high Lu/Hf ratio. Our study helps to define the architecture of the Tanzanian Craton and its evolution from a single age-source in the early Eoarchaean.
DS201612-2343
2016
Spencer, C.Thomas, R.J., Macey, P.H., Spencer, C., Dhansay, T., Diener, J.F.A., Lambert, C.W., Frei, D., Nguno, A.The Sperrgebeit Domain, Aurus Mountains, SW Namibia: a ~2020-850 Ma window within the Pan-African Gariep Orogen.Precambrian Research, Vol. 286, pp. 35-58.Africa, NamibiaGeochronology
DS1997-1092
1997
Spencer, C.H.Spencer, C.H.The electromagnetic spectrum and remote sensingEom., Nov. pp. 18-20GlobalRemote sensing - brief overview, Geophysics - radio waves
DS201312-0872
2013
Spencer, C.J.Spencer, C.J., Hawkesworth, C., Cawood, P.A., Dhuime, B.Not all supercontinents are created equal: Gondwana-Rodinia case study.Geology, Vol. 41, pp. 795-798.Gondwana, RodiniaGondwana
DS201412-0875
2014
Spencer, C.J.Spencer, C.J., Cawood, P.A., Hawkesowrth, C.J., Raub, T.D., Prave, A.R., Roberts, N.M.W.Proterozoic onset of crustal reworking and collisional tectonics: reappraisal of the zircon oxygen isotope record.Geology, in press availableMantleTectonics
DS201503-0171
2015
Spencer, C.J.Roberts, N.M.W., Spencer, C.J.The zircon archives of continent formation through time.Geological Society of London Special Publication: Continent formation through time., No. 389, pp. 197-225.MantleGeochronology
DS201710-2267
2017
Spencer, C.J.Spencer, C.J., Roberts, N.M.W., Santosh, M.Growth, destruction, and preservation of Earth's continental crust.Earth-Science Reviews, Vol. 172, pp. 87-106.Mantlegeodynamics

Abstract: From the scant Hadean records of the Jack Hills to Cenozoic supervolcanoes, the continental crust provides a synoptic view deep into Earth history. However, the information is fragmented, as large volumes of continental crust have been recycled back into the mantle by a variety of processes. The preserved crustal record is the balance between the volume of crust generated by magmatic processes and the volume destroyed through return to the mantle by tectonic erosion and lower crustal delamination. At present-day, the Earth has reached near-equilibrium between the amount of crust being generated and that being returned to the mantle at subduction zones. However, multiple lines of evidence support secular change in crustal processes through time, including magma compositions, mantle temperatures, and metamorphic gradients. Though a variety of isotopic proxies are used to estimate crustal growth through time, none of those currently utilized are able to quantify the volumes of crust recycled back into the mantle. This implies the estimates of preserved continental crust and growth curves derived therefrom represent only a minimum of total crustal growth. We posit that from the Neoarchean, the probable onset of modern-day style plate tectonics (i.e. steep subduction), there has been no net crustal growth (and perhaps even a net loss) of the continental crust. Deciphering changes from this equilibrium state through geologic time remains a continual pursuit of crustal evolution studies.
DS201809-2046
2018
Spencer, C.J.Johnson, T.E., Gardiner, N.J., Miljkovic, K., Spencer, C.J., Kirkland, C.L., Bland, P.A., Smithies, R.H.Are Earth's oldest felsic rocks impact melts? Acasta Gneiss ComplexGoldschmidt Conference, 1p. AbstractCanada, Northwest Territoriesmeteorite

Abstract: Earth’s oldest felsic rocks, the 4.02 billion-year-old Idiwhaa gneisses of the Acasta Gneiss Complex, northwest Canada, have compositions that are distinct from the felsic rocks that typify Earth’s ancient continental nuclei, implying they formed through a different process. Using phase equilibria and trace element modelling, we show that the Idiwhaa gneisses were produced by partial melting of ironrich amphibolite host rocks at very low pressures, equating to the uppermost ~3 km of mafic crust. The heat required for such shallow melting is most easily explained through meteorite impacts. Hydrodynamic impact modelling shows that, not only is this scenario physically plausible, but the region of shallow melting appropriate to formation of the Idiwhaa gneisses would have been widespread. Given the predicted high flux of meteorites during the late Hadean, impact melting may have been the predominant mechanism that generated Hadean felsic rocks.
DS201810-2318
2018
Spencer, C.J.Gardiner, N.J., Searle, M.P., Morley, C.K., Robb, L.J., Whitehouse, M.J., Roberts, N.M.W., Kirkland, C.L., Spencer, C.J.The crustal architecture of Myanmar imaged through zircon U-Pb, Lu-Hf and O isotopes: tectonic and metallogenic implications. ReviewGondwana Research, Vol. 62, pp. 27-60.Asia, Myanmartectonics

Abstract: The Tethys margin in central and eastern Asia is comprised of continental terranes separated by suture zones, some of which remain cryptic. Determining the crustal architecture, and therefore the geological history, of the Eastern Tethyan margin remains challenging. Sited in the heart of this region, Myanmar is a highly prospective but poorly explored minerals jurisdiction. A better understanding of Myanmar's mineralization can only be realized through a better understanding of its tectonic history, itself reflected in at least four major magmatic belts. The Eastern and the Main Range Provinces are associated with the Late Permian to Early Triassic closure of Palaeo-Tethys. The Mogok-Mandalay-Mergui Belt and Wuntho-Popa Arc are a response to the Eocene closure of Neo-Tethys. However, magmatic ages outside these two orogenic events are also recorded. We present new zircon U-Pb, Lu-Hf and O isotope data from magmatic rocks across Myanmar, which we append to the existing dataset to isotopically characterize Myanmar's magmatic belts. Eastern Province Permian I-type magmatism has evolved eHf (-10.9 to -6.4), whilst Main Range Province Triassic S-type magmatism also records evolved eHf (-13.5 to -8.8). The Mogok-Mandalay-Mergui Belt is here divided into the Tin Province and the Mogok Metamorphic Belt. The Tin Province hosts ca. 77-50 Ma magmatism with evolved eHf (-1.2 to -15.2), and d 18 O of 5.6-8.3‰. The Mogok Metamorphic Belt exhibits a more complex magmatic and metamorphic history, and granitoids record Jurassic, Late Cretaceous, and Eocene to Miocene phases of magmatism, all of which exhibit evolved eHf values between -4.6 and -17.6, and d 18 O between 6.3 and 9.2‰. From the Tagaung-Myitkyina Belt, we report a magmatic age of 172 Ma and eHf of 18.1 to 10.8. To accommodate the geological evidence, we propose a tectonic model for Myanmar involving a greater Sibumasu - where the documented zircon isotopic variations reflect compositional variations in magmatic source - and invoke the role of a Tengchong Block. The Baoshan Block and Greater Sibumasu were likely assembled on or before the Triassic, a former Andean margin and suture which may lie across the Northern Shan Plateau, and reflected in isotopic differences between the northern and southern parts of the Mogok Metamorphic Belt. This contiguous Sibumasu-Baoshan Block then sutured onto the Indochina margin in the Late Triassic. We propose that a Tengchong Block within Myanmar provides for a southerly termination of the Meso-Tethys suture immediately north of the Mogok area. A discrete Tengchong Block may explain a discontinuous arc of Late Triassic to Jurassic I-type magmatism in central Myanmar, representing an Andean-type margin sited above a subducting Meso-Tethys on the margin of Sibumasu. The Tengchong Block sutured onto Greater Sibumasu before the Late Cretaceous, after which subduction of Neo-Tethys drove the magmatism of the Wuntho-Popa Arc and ultimately that of the Tin Province. The metallogenic character of granite belts in Myanmar reflects the crustal architecture of the region, which is remarkable for its prolific endowment of granite-hosted Sn-W mineralization in two quite distinct granite belts related to sequential Indosinian and Himalayan orogenesis.
DS201811-2582
2018
Spencer, C.J.Johnson, T.E., Gardiner, N.J., Miljkovic, K., Spencer, C.J., Kirkland, C.L., Bland, P.A., Smithies, H.An impact melt origin for Earth's oldest known evolved rocks. Acasta GneissNature Geoscience, Vol. 11, pp. 795-799.Canada, Northwest Territoriesmelting

Abstract: Earth’s oldest evolved (felsic) rocks, the 4.02-billion-year-old Idiwhaa gneisses of the Acasta Gneiss Complex, northwest Canada, have compositions that are distinct from the felsic rocks that typify Earth’s ancient continental nuclei, implying that they formed through a different process. Using phase equilibria and trace element modelling, we show that the Idiwhaa gneisses were produced by partial melting of iron-rich hydrated basaltic rocks (amphibolites) at very low pressures, equating to the uppermost ~3?km of a Hadean crust that was dominantly mafic in composition. The heat required for partial melting at such shallow levels is most easily explained through meteorite impacts. Hydrodynamic impact modelling shows not only that this scenario is physically plausible, but also that the region of shallow partial melting appropriate to formation of the Idiwhaa gneisses would have been widespread. Given the predicted high flux of meteorites in the late Hadean, impact melting may have been the predominant mechanism that generated Hadean felsic rocks.
DS201902-0290
2019
Spencer, C.J.Li, Z.X., Mitchell, R.N., Spencer, C.J., Ernst, R., Pisarevsky, S., Kirscher, U., Murphy, J.B.Decoding Earth's rhythms: modulation of supercontinent cycles by longer superocean episodes.Precambrian Research, Vol. 323, pp. 1-5.Mantlesubduction

Abstract: The supercontinent cycle of episodic assembly and breakup of almost all continents on Earth is commonly considered the longest period variation to affect mantle convection. However, global zircon Hf isotopic signatures and seawater Sr isotope ratios suggest the existence of a longer-term variation trend that is twice the duration of the supercontinent cycle. Here we propose that since ?2 billion years ago the superocean surrounding a supercontinent, as well as the circum-supercontinent subduction girdle, survive every second supercontinent cycle. This interpretation is in agreement with global palaeogeography and is supported by variations in passive margin, orogen, and mineral deposit records that each exhibits both ?500-700 million years periodic signal and a 1000-1500 million years variation trend. We suggest that the supercontinent cycle is modulated by an assembly that alternates between dominantly extroversion after a more complete breakup, and dominantly introversion after an incomplete breakup of the previous supercontinent.
DS201909-2073
2019
Spencer, C.J.Pastor-Galan, D., Nance, R.D., Murphy, J.B., Spencer, C.J.Supercontinents: myths, mysteries, and milestones.Researchgate, 26p. PdfGlobalsupercontinents

Abstract: There is an emerging consensus that Earth's landmasses amalgamate quasi-periodically into supercontinents, interpreted to be rigid super-plates essentially lacking tectonically active inner boundaries and showing little internal lithosphere-mantle interactions. The formation and disruption of supercontinents have been linked to changes in sea-level, biogeochemical cycles, global climate change, continental margin sedimentation, large igneous provinces, deep mantle circulation, outer core dynamics and Earth's magnetic field. If these hypotheses are correct, long-term mantle dynamics and much of the geological record, including the distribution of natural resources, may be largely controlled by these cycles. Despite their potential importance, however, many of these proposed links are, to date, permissive rather than proven. Sufficient data are not yet available to verify or fully understand the implications of the supercontinent cycle. Recent advances in many fields of geoscience provide clear directions for investigating the supercontinent cycle hypothesis and its corollaries but they need to be vigorously pursued if these far-reaching ideas are to be substantiated.
DS201911-2553
2019
Spencer, C.J.Pastor-Galan, D., Nance, R.D., Murphy, J.B., Spencer, C.J.Supercontinents: myths, mysteries, and milestones.IN: Cycle Concepts in Plate Tectonics, editors Wilson and Houseman , Geological Society of London special publication 470, pp. 39-64.Mantleplate tectonics

Abstract: There is an emerging consensus that Earth's landmasses amalgamate quasi-periodically into supercontinents, interpreted to be rigid super-plates essentially lacking tectonically active inner boundaries and showing little internal lithosphere-mantle interactions. The formation and disruption of supercontinents have been linked to changes in sea-level, biogeochemical cycles, global climate change, continental margin sedimentation, large igneous provinces, deep mantle circulation, outer core dynamics and Earth's magnetic field. If these hypotheses are correct, long-term mantle dynamics and much of the geological record, including the distribution of natural resources, may be largely controlled by these cycles. Despite their potential importance, however, many of these proposed links are, to date, permissive rather than proven. Sufficient data are not yet available to verify or fully understand the implications of the supercontinent cycle. Recent advances in many fields of geoscience provide clear directions for investigating the supercontinent cycle hypothesis and its corollaries but they need to be vigorously pursued if these far-reaching ideas are to be substantiated.
DS202008-1384
2020
Spencer, C.J.Doucet, L.S., Li, Z-X., Gamel El Dien, H., Pourteau, A., Murphy, B., Collins, W.J., Mattielli, N., Olierook, H.K.H., Spencer, C.J., Mitchell, R.N.Distinct formation history for deep mantle domains reflected in geochemical differences.Nature Geoscience, Vol. 13, pp. 511-515. pdfMantlegeochemistry

Abstract: The Earth’s mantle is currently divided into the African and Pacific domains, separated by the circum-Pacific subduction girdle, and each domain features a large low shear-wave velocity province (LLSVP) in the lower mantle. However, it remains controversial as to whether the LLSVPs have been stationary through time or dynamic, changing in response to changes in global subduction geometry. Here we compile radiogenic isotope data on plume-induced basalts from ocean islands and oceanic plateaus above the two LLSVPs that show distinct lead, neodymium and strontium isotopic compositions for the two mantle domains. The African domain shows enrichment by subducted continental material during the assembly and breakup of the supercontinent Pangaea, whereas no such feature is found in the Pacific domain. This deep-mantle geochemical dichotomy reflects the different evolutionary histories of the two domains during the Rodinia and Pangaea supercontinent cycles and thus supports a dynamic relationship between plate tectonics and deep-mantle structures.
DS202009-1625
2020
Spencer, C.J.Doucet, L.S., Li, Z-X., GamelEl Dien, H., Pourteau, A., Murphy, J.B., Collins, W.J., Mattielli, N., Olierook, H.K.H., Spencer, C.J., Mitchell, R.N.Distinct formation history for deep mantle domains reflected in geochemical differences.Nature Geoscience, Vol. 13, July pp. 511-515. pdfMantlegeochemistry

Abstract: The Earth’s mantle is currently divided into the African and Pacific domains, separated by the circum-Pacific subduction girdle, and each domain features a large low shear-wave velocity province (LLSVP) in the lower mantle. However, it remains controversial as to whether the LLSVPs have been stationary through time or dynamic, changing in response to changes in global subduction geometry. Here we compile radiogenic isotope data on plume-induced basalts from ocean islands and oceanic plateaus above the two LLSVPs that show distinct lead, neodymium and strontium isotopic compositions for the two mantle domains. The African domain shows enrichment by subducted continental material during the assembly and breakup of the supercontinent Pangaea, whereas no such feature is found in the Pacific domain. This deep-mantle geochemical dichotomy reflects the different evolutionary histories of the two domains during the Rodinia and Pangaea supercontinent cycles and thus supports a dynamic relationship between plate tectonics and deep-mantle structures.
DS202009-1673
2020
Spencer, C.J.Volante, S., Pouteau, A., Collins, W.J., Blereau, E., Li, Z-X., Smit, M., Evans, N.J., Nordsvan, A.R., Spencer, C.J., McDonald, B.J., Li, J., Gunter, C.Multiple P-T-d-t paths reveal the evolution of the final Nuna assembly in northeast Australia. Georgetown InlierJournal of Metamorphic Geology, Vol. 38, pp. 593-627.Australiageochronology

Abstract: The final assembly of the Mesoproterozoic supercontinent Nuna was marked by the collision of Laurentia and Australia at 1.60 Ga, which is recorded in the Georgetown Inlier of NE Australia. Here, we decipher the metamorphic evolution of this final Nuna collisional event using petrostructural analysis, major and trace element compositions of key minerals, thermodynamic modelling, and multi?method geochronology. The Georgetown Inlier is characterised by deformed and metamorphosed 1.70-1.62 Ga sedimentary and mafic rocks, which were intruded by c. 1.56 Ga old S?type granites. Garnet Lu-Hf and monazite U-Pb isotopic analyses distinguish two major metamorphic events (M1 at c. 1.60 Ga and M2 at c. 1.55 Ga), which allows at least two composite fabrics to be identified at the regional scale—c. 1.60 Ga S1 (consisting in fabrics S1a and S1b) and c. 1.55 Ga S2 (including fabrics S2a and S2b). Also, three tectono?metamorphic domains are distinguished: (a) the western domain, with S1 defined by low?P (LP) greenschist facies assemblages; (b) the central domain, where S1 fabric is preserved as medium?P (MP) amphibolite facies relicts, and locally as inclusion trails in garnet wrapped by the regionally dominant low?P amphibolite facies S2 fabric; and (c) the eastern domain dominated by upper amphibolite to granulite facies S2 foliation. In the central domain, 1.60 Ga MP-medium?T (MT) metamorphism (M1) developed within the staurolite-garnet stability field, with conditions ranging from 530-550°C at 6-7 kbar (garnet cores) to 620-650°C at 8-9 kbar (garnet rims), and it is associated with S1 fabric. The onset of 1.55 Ga LP-high?T (HT) metamorphism (M2) is marked by replacement of staurolite by andalusite (M2a/D2a), which was subsequently pseudomorphed by sillimanite (M2b/D2b) where granite and migmatite are abundant. P-T conditions ranged from 600 to 680°C and 4-6 kbar for the M2b sillimanite stage. 1.60 Ga garnet relicts within the S2 foliation highlight the progressive obliteration of the S1 fabric by regional S2 in the central zone during peak M2 metamorphism. In the eastern migmatitic complex, partial melting of paragneiss and amphibolite occurred syn? to post? S2, at 730-770°C and 6-8 kbar, and at 750-790°C and 6 kbar, respectively. The pressure-temperature-deformation-time paths reconstructed for the Georgetown Inlier suggest a c. 1.60 Ga M1/D1 event recorded under greenschist facies conditions in the western domain and under medium?P and medium?T conditions in the central domain. This event was followed by the regional 1.56-1.54 Ga low?P and high?T phase (M2/D2), extensively recorded in the central and eastern domains. Decompression between these two metamorphic events is ascribed to an episode of exhumation. The two?stage evolution supports the previous hypothesis that the Georgetown Inlier preserves continental collisional and subsequent thermal perturbation associated with granite emplacement.
DS202101-0040
2021
Spencer, C.J.Wang, C., Mitchell, Ross.N., Murphy, J.B., Peng, P., Spencer, C.J.The role of megacontinents in the supercontinent cycle.Geology, in press availabe 5p. PdfMantlePangea

Abstract: Supercontinent Pangea was preceded by the formation of Gondwana, a “megacontinent” about half the size of Pangea. There is much debate, however, over what role the assembly of the precursor megacontinent played in the Pangean supercontinent cycle. Here we demonstrate that the past three cycles of supercontinent amalgamation were each preceded by ~200 m.y. by the assembly of a megacontinent akin to Gondwana, and that the building of a megacontinent is a geodynamically important precursor to supercontinent amalgamation. The recent assembly of Eurasia is considered as a fourth megacontinent associated with future supercontinent Amasia. We use constraints from seismology of the deep mantle for Eurasia and paleogeography for Gondwana to develop a geodynamic model for megacontinent assembly and subsequent supercontinent amalgamation. As a supercontinent breaks up, a megacontinent assembles along the subduction girdle that encircled it, at a specific location where the downwelling is most intense. The megacontinent then migrates along the girdle where it collides with other continents to form a supercontinent. The geometry of this model is consistent with the kinematic transitions from Rodinia to Gondwana to Pangea.
DS202102-0205
2020
Spencer, C.J.Martin, E.L., Spencer, C.J., Collins, W.J., Thomas, R.J., Macey, P.H., Roberts, N.M.W.The core of Rodinia formed by the juxtaposition of opposed retreating and advancing accretionary orogens.Earth-Science Reviews, Vol. 211, doi.org/10.1016 /j.earscirev.2020 .103413 17p. Pdf Globalcratons

Abstract: Long-lived (800?Ma) Paleo- to Mesoproterozoic accretionary orogens on the margins of Laurentia, Baltica, Amazonia, and Kalahari collided to form the core of the supercontinent, Rodinia. Accretionary orogens in Laurentia and Baltica record predominately radiogenic zircon ?Hf(t) and whole-rock Pb isotopic compositions, short crustal residence times (ca. 0.5?Ga), and the development of arc-backarc complexes. The accretionary orogenic record of Laurentia and Baltica is consistent with a retreating accretionary orogen and analogous to the Phanerozoic western Pacific orogenic system. In contrast, the Mesoproterozoic orogens of Amazon and Kalahari cratons record unradiogenic zircon ?Hf(t) values, ca. 0.8?Ga crustal residence times, and more ancient whole-rock Pb isotopic signatures. The accretionary orogenic record of Amazonia and Kalahari indicates the preferential incorporation of cratonic material in continental arcs of advancing accretionary orogens comparable to the Phanerozoic eastern Pacific orogenic system. Based on similarities in the geodynamic evolution of the Phanerozoic circum-Pacific orogens peripheral to Gondwana/Pangea, we suggest that the Mesoproterozoic accretionary orogens formed as peripheral subduction zones along the margin of the supercontinent Nuna (ca. 1.8-1.6?Ga). The eventual collapse of this peripheral subduction zone onto itself and closure of the external ocean around Nuna to form Rodinia is equivalent to the projected future collapse of the circum-Pacific subduction system and juxtaposition of Australia-Asia with South America. The juxtaposition of advancing and retreating accretionary orogens at the core of the supercontinent Rodinia demonstrates that supercontinent assembly can occur by the closure of external oceans and indicates that future closure of the Pacific Ocean is plausible.
DS202111-1786
2021
Spencer, C.J.Spencer, C.J.Enigmatic mid-proterozoic orogens: hot, thin, and low.Geophysical Research Letters, doi:10.1029/2021GL093312Mantleorogeny

Abstract: Orogenesis is the process whereby tectonic plates converge and mountain systems are created. In the case of the Andes and Himalayas, orogenesis resulted in significant thickening of the continental crust. Recent attempts to provide geochemical proxies for crustal thickness have allowed geologists to track the thickness of the crust through geologic time. One period of time in particular between 1850 and ?850 million years ago-the mid-Proterozoic-was characterized as having relatively thin crust. Some have argued this is evidence for a period of "orogenic quiescence." However, the geologic record is rife with ancient orogenic belts during this time as evidenced by the metamorphic and igneous rock records. In particular, the metamorphic rocks display higher than normal temperature/pressure ratios indicating unusually hot crust. We propose that the thin crust at this time is a product of high temperatures resulting in greater crustal flow and therefore lower mountain ranges.
DS1989-1266
1989
Spencer, J.E.Reynolds, S.J., Spencer, J.E., Asmerom, Y., DeWitt, E., LaubachEarly Mesozoic uplift in west-central Arizona and southeastern CaliforniaGeology, Vol. 17, No. 3, March pp. 207-211Arizona, CaliforniaGreat Basin area, Proterozoic
DS1995-1810
1995
Spencer, J.E.Spencer, J.E.Uplift of the Colorado Plateau due to lithosphere attenuation during Laramide low angle subduction.Eos, Vol. 76, No. 46, Nov. 7. p.F605. Abstract.Colorado PlateauCrust, Geodynamics
DS1999-0699
1999
Spencer, J.E.Spencer, J.E.The active southwest margin of the Colorado Plateau: uplift of mantleorigin: discussion and reply.Geological Society of America (GSA) Bulletin., Vol. 111, No. 1, pp. 154-7.Colorado PlateauTectonics
DS200812-0426
2007
Spencer, L.Graham, I.T., Spencer, L., Yaxley, G., Barron, L.The use of zircon in diamond exploration - a preliminary case study from the Cempaka deposit, SE Kalimantan, Indonesia.Geological Society of Australia Abstracts, No. 86, pp. 32-35.IndonesiaDeposit - Cempaka
DS1900-0239
1904
Spencer, L.J.Bauer, M., Spencer, L.J.Precious Stonesá1904Griffin And Co., INDIA PP. 140-155; Brasil PP. 155-179; SOUTH AFRICA PP. 179-Australia, Borneo, Brazil, Guyana, India, South Africa, United States, RussiaDiamond Occurrence
DS1900-0275
1904
Spencer, L.J.Spencer, L.J.Gemology. Translation of Bauer BookUnknown., 711P.Africa, South AfricaDiamonds
DS1910-0104
1910
Spencer, L.J.Spencer, L.J.Notes on the Weight of the Culli nan Diamond and on the Value of the Carat Weight.Mineralogical Magazine, Vol. 15, No. 71, PP. 318-326. ALSO: CHEM. NEWS, Vol. 101, PPSouth Africa, TransvaalCrystallography, Diamonds Notable, Premier Mine
DS1910-0214
1911
Spencer, L.J.Spencer, L.J.The Larger Diamonds of South AfricaMineralogical Magazine., Vol. 16, No. 74, PP. 140-148.South AfricaDiamonds Notable
DS1920-0197
1924
Spencer, L.J.Spencer, L.J.An Inclusion of Magnetite in DiamondMineralogical Magazine., Vol. 20, No. 107, PP. 245-247. ALSO: CHEM. abstract., Vol.South Africa, GlobalBlack Inclusions
DS1930-0228
1936
Spencer, L.J.Spencer, L.J.A Key to Precious Stones. #2London And Glasgow: Blackie And Sons Ltd., 237P.South AfricaHistory, Diamonds Notable, Kimberley
DS1940-0131
1946
Spencer, L.J.Spencer, L.J.A Key to Precious Stones. #1London., GlobalKimberlite, Kimberley, Janlib, Gemology
DS1992-1338
1992
Spencer, R.Schena, G.D., Gochin, R.J., Spencer, R.Assessing impact of a mineral project on the economy of a developing country -part 1: input-output modelsInstitute of Mining and Metallurgy (IMM) Transactions, Vol. 101, pp. A 29-A35GlobalEconomics, ore reserves, Ranking mineral projects
DS1992-1339
1992
Spencer, R.Schena, G.D., Gochin, R.J., Spencer, R.Assessing impact of a mineral project on the economy of a developing country- part 2: cost /benefit analysisTransactions of the Institute of Mining and Metallurgy (IMM), Vol. 100, pp. A181-A188NamibiaEconomics, Diamond mining mentioned
DS1999-0700
1999
Spencer, R.Spencer, R.The Grib pipe and diamonds in northwest EuropeProspectors and Developers Association of Canada (PDAC) abstract volume, p. 7, 8.Europe, Russia, Kola, Norway, Sweden, Baltic States, LaplandOverview, Deposit - Grib
DS200512-1029
2005
Spencer, R.Spencer, R.Northwest Europe: the last frontier.PDAC 2005, Abstract 1p.Europe, Finland, Kola Peninsula, Baltic ShieldBrief overview abstract
DS201805-0967
2007
Spencer, R.O'Brien, H., Philippips, D., Spencer, R.Isotopic ages of Lentiira-Kuhmo-Kostomuksha olivine lamproite - Group II kimberlites NOTE Date of publ. Bulletin of the Geological Survey of Finland, Vol. 79, 2, pp. 203-215.Europe, Finlanddeposit - Lentiira Kuhmo

Abstract: The Lentiira-Kuhmo-Kostomuksha triangle, along the Finland - Russian border and within the central part of the Archean Karelian craton, contains numerous examples of phlogopite-rich, ultramafic, mantle-xenocryst-bearing and, in some cases, diamond-bearing dike rocks. Laser probe Ar-Ar data on phlogopite from 3 dike rocks on the Finnish side (Lentiira, Kuhmo) all gave ages within error of each other, 1202 ± 3 Ma (2?), 1199 ± 3 Ma (2?) and 1204 ± 4 Ma (2?) while a fourth sample produced mixed ages. Published Rb-Sr dates on mineralogically and chemically similar dikes from the Russian side (Kostomuksha) are 1232 ± 5 Ma. The question remains open whether these represent two distinct age populations or whether differences in isotopic system behavior are the reason for the 30 m.y. age difference.
DS2003-1025
2003
Spencer, R.G.O'Brien, H.E., Lehtonen, M.L., Spencer, R.G., Birnie, A.C.Lithospheric mantle eastern Finland, a 240 km 3D transect8 Ikc Www.venuewest.com/8ikc/program.htm, Session 8, AbstractFinlandDiamond exploration - geophysics, seismics
DS200412-1456
2003
Spencer, R.G.O'Brien, H.E., Lehtonen, M.L., Spencer, R.G., Birnie, A.C.Lithospheric mantle eastern Finland, a 240 km 3D transect.8 IKC Program, Session 8, AbstractEurope, FinlandDiamond exploration - geophysics, seismics
DS201212-0527
2012
Spencer, R.G.O'Brien, H.E., Birnie, A.C., Spencer, R.G.Diamondiferous megacrystal garnet and orthopyroxene from Liqhobong, Lesotho.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractAfrica, LesothoDeposit - Liqhobong
DS201212-0528
2012
Spencer, R.G.O'Brien, H.E., Spencer, R.G.Lemphane kimberlite diamond project: petrology update.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractAfrica, LesothoDeposit - Lemphane
DS2002-1530
2002
Spencer, R.M.Spencer, R.M., Montenegro, J.L., Gaibor,Perez,MantillaThe Portovelo Zaruma mining camp: southwest Ecuador: porphyry and epithermal environments.Seg Newsletter, No. 49, April, pp. 1,8-14.EcuadorCopper, gold, Deposit - Portovelo Zaruma, R-Nivel, Muluncay
DS1940-0132
1946
Spencer, R.V.Spencer, R.V.Exploration of the Magnet Cove Rutile Company Property, Hotspring County, Arkansaw.United States Bureau of Mines Report INV., No. 3900, 23P.United States, Gulf Coast, Arkansas, Hot Spring CountyProspecting
DS1940-0037
1941
Spencer. L.jSpencer. L.jThe Gibeon Shower of Meteoritic Irons in Southwest AfricaMineralogical Magazine, Vol. 26, No. 176, PP. 19-35.Southwest Africa, NamibiaMeteorites, Brukkaros
DS200512-0238
2004
Spengler, D.Dobrzhinetskaya, L.F., Green, H.W., Renfro, A.P., Bozhilov, K.N., Spengler, D., Van Roemund, H.L.M.Precipitation of pyroxenes and Mg2SiO4 from majorite garnet: simulation of peridotite exhumation from great depth.Terra Nova, Vol. 16, 6, pp. 325-330.MantlePetrology - peridotite
DS200912-0721
2009
Spengler, D.Spengler, D., Brueckner, H.K., Herman, L.M., Van Roermund, Drury, MasonLong lived, cold burial of Baltica to 200 km depth.Earth and Planetary Science Letters, Vol. 281, 1-2, April 30, pp. 27-35.Europe, Baltic ShieldSubduction
DS201112-0990
2011
Spengler, D.Spengler, D., Nishihara, Y., Fujino, K.Super Si garnet breakdown kinetics and implications for craton evolution.Goldschmidt Conference 2011, abstract p.1921.MantleConvection
DS201312-0873
2013
Spengler, D.Spengler, D.SCLM super Si garnet traces the Archean.Goldschmidt 2013, 1p. AbstractMantleGarnet
DS201804-0741
2018
Spengler, D.Spengler, D., van Roermund, H.L.M., Drury, M.R.Deep komatiite signature in cratonic mantle pyroxenite… websterite/Rae cratonJournal of Metamorphic Geology, in press availableEurope, Greenland, Norwaymineral chemistry

Abstract: We present new and compiled whole rock modal mineral, major and trace element data from extremely melt depleted but pyroxenite and garnet(?ite) bearing Palaeoarchaean East Greenland cratonic mantle, exposed as three isolated, tectonically strained orogenic peridotite bodies (Ugelvik, Raudhaugene, Midsundvatnet) in western Norway. The studied lithologies comprise besides spinel? and/or garnet?bearing peridotite (dunite, harzburgite, lherzolite) garnet?clinopyroxenite and partially olivine?bearing garnet?orthopyroxenite and ?websterite. Chemical and modal data and spatial relationships between different rock types suggest deformation to have triggered mechanical mixing of garnet?free dunite with garnet?bearing enclosures that formed garnet?peridotite. Inclusions of olivine in porphyroclastic minerals of pyroxenite show a primary origin of olivine in olivine?bearing variants. Major element oxide abundances and ratios of websterite differ to those in rocks expected to form by reaction of peridotite with basaltic melts or silica?rich fluids, but resemble those of Archaean Al?enriched komatiite (AEK) flows from Barberton and Commondale greenstone belts, South Africa. Websterite GdN/YbN, 0.49-0.65 (olivine?free) and 0.73-0.85 (olivine?bearing), overlaps that of two subgroups of AEK, GdN/YbN 0.25-0.55 and 0.77-0.90, with each of them being nearly indistinguishable from one another in rare earth element fractionation but also concentration. Websterite MgO content is high, 22.7-29.0 wt.%, and Zr/Y is very low, 0.1-1.0. The other, non?websteritic pyroxenites overlap - when mechanically mixed together with garnetite - in chemistry with that of AEK. It follows an origin of websterite and likely all pyroxenite that involves melting of a garnet?bearing depleted mantle source. Pyroxene exsolution lamellae in the inferred solidus garnet in all lithological varieties require the pyroxenites to have crystallised in the majorite garnet stability field, at 3-4 GPa (90-120 km depth) at minimum 1600 °C. Consequently, we interpret the websterites to represent the first recognised deep plutonic crystallisation products that formed from komatiite melts. The other pyroxenitic rocks are likely fragments of such crystallisation products. An implication is that a mantle plume environment contributed to the formation of (one of) the worldwide oldest lithospheric mantle underneath the eastern Rae craton.
DS201807-1528
2018
Spengler, D.Spengler, D., van Roermund, H.L.M., Drury, M.R.Deep komatiite signature in cratonic mantle pryoxenite.Journal of Metamorphic Geology, Vol. 36, 5, pp. 591-602.Mantlecraton

Abstract: We present new and compiled whole?rock modal mineral, major and trace element data from extremely melt depleted but pyroxenite and garnet(?ite)?bearing Palaeoarchean East Greenland cratonic mantle, exposed as three isolated, tectonically strained orogenic peridotite bodies (Ugelvik, Raudhaugene and Midsundvatnet) in western Norway. The studied lithologies comprise besides spinel? and/or garnet?bearing peridotite (dunite, harzburgite, lherzolite) garnet?clinopyroxenite and partially olivine?bearing garnet?orthopyroxenite and ?websterite. Chemical and modal data and spatial relationships between different rock types suggest deformation to have triggered mechanical mixing of garnet?free dunite with garnet?bearing enclosures that formed garnet?peridotite. Inclusions of olivine in porphyroclastic minerals of pyroxenite show a primary origin of olivine in olivine?bearing variants. Major element oxide abundances and ratios of websterite differ to those in rocks expected to form by reaction of peridotite with basaltic melts or silica?rich fluids, but resemble those of Archean Al?enriched komatiite (AEK) flows from Barberton and Commondale greenstone belts, South Africa. Websterite GdN/YbN, 0.49-0.65 (olivine?free) and 0.73-0.85 (olivine?bearing), overlaps that of two subgroups of AEK, GdN/YbN 0.25-0.55 and 0.77-0.90, with each of them being nearly indistinguishable from one another in not only rare earth element fractionation but also concentration. Websterite MgO content is high, 22.7-29.0 wt%, and Zr/Y is very low, 0.1-1.0. The other, non?websteritic pyroxenites overlap—when mechanically mixed together with garnetite—in chemistry with that of AEK. It follows an origin of websterite and likely all pyroxenite that involves melting of a garnet?bearing depleted mantle source. Pyroxene exsolution lamellae in the inferred solidus garnet in all lithological varieties require the pyroxenites to have crystallized in the majorite garnet stability field, at 3-4 GPa (90-120 km depth) at minimum 1,600°C. Consequently, we interpret the websterites to represent the first recognized deep plutonic crystallization products that formed from komatiite melts. The other pyroxenitic rocks are likely fragments of such crystallization products. An implication is that a mantle plume environment contributed to the formation of (one of) the worldwide oldest lithospheric mantle underneath the eastern Rae craton.
DS201902-0321
2019
Spengler, D.Spengler, D., Alifirova, T.A.Formation of Siberian cratonic mantle websterites from high Mg magmas.Lithos, Vol. 326-327, pp. 384-396.Russiawebsterites

Abstract: Garnet-(olivine) websterite xenoliths from the lithospheric mantle of the central and northeastern parts of the Siberian Craton contain exsolution microstructures after Si- and Ti-rich precursor garnets. We petrographically, geochemically, and thermobarometrically investigated 13 such xenoliths from the Mir, Obnazhennaya, and Udachnaya kimberlite pipes. All samples contain garnet grains with needle- to lamellae-shaped precipitates (up to 3.0?vol%), including Ti-oxide and/or pyroxene. Orthopyroxene and clinopyroxene grains host oriented lamellae of complementary Ca-rich and Ca-poor pyroxene, respectively, in addition to lamellae of garnet and Ti- and/or Cr-oxides. The common exsolution lamellae assemblages in garnet and pyroxene imply that exsolution occurred during cooling from high-temperature precursors. Exsolution is unlikely to have resulted from variations in pressure, given experimental and thermodynamic constraints. Host mineral partitioning of transition metal and lanthanide elements with different diffusivities record temperatures that range between those of local geotherms and a dry pyroxenite solidus. Inferred magmatic minimum temperatures of 1500-1700?°C satisfy the physical conditions predicted from experimental studies of the solubility of excess Si and Ti in garnet. Granular inclusions of all major minerals within each other imply an overlapping crystallisation history. The reconstructed compositions of the websterite whole-rocks have high MgO contents (15.7-35.7?wt%). A plot of MgO/SiO2 versus SiO2 forms an array, apart from the compositions of natural websterites that formed by interaction of peridotite with basaltic or siliceous melts. The array overlaps the compositional range of komatiite flows from Commondale and Barberton, South Africa, including spinifex, massive, and cumulate subtypes of komatiites. Other major and minor element abundances and ratios of the Siberian websterite suite resemble those of South African Al-enriched komatiites and are distinct from melt-rock reaction websterites. Therefore, the mineral microstructures and geochemistry of the Siberian websterites are suggestive of the former presence of a thermal anomaly. We propose that mantle plume activity or a similar form of lower-mantle ascent played a major role in stabilising cratonic nuclei before amalgamation of the present-day Siberian Craton.
DS201910-2251
2019
Spengler, D.Cutts, J.A., Smit, M.A., Spengler, D., Kooijman, E., van Roermund, H.L.M.Two billion years of mantle evolution in sync with global tectonic cycles.Earth and Planetary Science letters, Vol. 528, 115820 11p.Mantlecraton

Abstract: The continental crust and sub-continental lithospheric mantle (SCLM) are co-dependent reservoirs in terms of their geochemistry, tectonics, and long-term evolution. Obtaining insight into the mechanisms of lithosphere formation and differentiation requires robust constraint on the complex petrological history of mantle rocks. This has proven difficult as samples from the deep mantle are rare and, although many may have formed in the Archean, no such age has been obtained directly from mantle-derived silicate minerals. Lutetium-hafnium geochronology of garnet has the potential of overcoming this limitation. In this study, this technique was applied on fragments of the SCLM exposed in the Norwegian Caledonides. The chronologic record of these rocks is rich and extensive, yet it is difficult to interpret and is, in part, inconsistent. Our Lu-Hf results from supersilicic pyrope in dunite provide the first Archean internal isochron ages for mantle rocks. These ages are consistent with a period of juvenile crust formation worldwide and provide a record of deeply sourced mantle upwellings from >350 km depth. Results from fertile rock types indicate that melting and isotope re-equilibration occurred in sync with two Proterozoic supercontinent break-up events that are recorded in the Laurentian and Baltic lithospheres. Together, the results indicate that since its extraction during a period of rapid Archean crustal growth, the SCLM appears to have largely been at petro-physical and chemical stasis, with the exception of major episodes of continental break-up. The evolution of the SCLM is thus, highly punctuated and ultimately controlled by the Wilson cycle.
DS202002-0171
2019
Spengler, D.Cutts, J.A., Smit, M., Spengler, D., van Roermind, H., Kooijman, E.Punctuated evolution of the Archean SCLM in sync with the supercontinent cycle. Western Gneiss ComplexAmericam Geophysical Union Fall meeting, 1p. AbstractEurope, Norwayeclogites, peridotites

Abstract: The preservation of Archean cratons is typically attributed to the presence of a highly-depleted and buoyant sub-continental lithospheric mantle (SCLM) that is equally old or older than its overlying crust. Time constraints on the formation and petrological evolution of the SCLM are key to investigating its long-term evolution and role in the formation and preservation of the continental crust. Nevertheless, such constraints are difficult to obtain as well-preserved samples of the SCLM are rare and typically lack conventional chronometric minerals. The history of SCLM rocks is typically inferred on the basis of model ages, many of which indicate an Archean origin; however, these dates are difficult to link to specific mineral assemblages or chemical signatures, and the petrological and dynamic processes that these represent. Garnet Lu-Hf geochronology is one of the few chronometers that could overcome this limitation. In this study, a refined method in Lu-Hf garnet chronology was applied to fragments of the Laurentian SCLM that are now exposed as orogenic peridotites in the ultrahigh-pressure domains of the Western Gneiss Complex, Norway. The peridotite bodies comprise a variety of unusually well-preserved rock types-from dunites that record decompression and melting at >350 km depth to fertile lithologies produced by melting and fluid metasomatism. Our internal isochron results from pyrope (after exsolution from majorite) in dunite samples yielded identical Neoarchean ages; these are the first-ever obtained for mantle garnet. The ages coincide with a time interval during which there was voluminous juvenile crust formation, indicating a link between this global process and the deeply sourced mantle upwellings that these samples represent. Internal isochrons from websterite-and clinopyroxenite-hosted pyrope yielded Meso-to Neoproterozoic ages that exactly match two distinct supercontinent break-up events in the overlying continental crust. Together, the new Lu-Hf results indicate that since its extraction during a period of widespread Archean crustal growth, the Laurentian SCLM appears to have largely been at petro-physical and chemical stasis and evolved only during short pulses that ran in sync with the supercontinent cycle.
DS202101-0033
2020
Spengler, D.Spengler, D., Alifirova, T.A.Formation of Siberian cratonic mantle websterites from high - Mg magmas.Lithos, in press available 13p. PdfRussiadeposit - Mir, Obnazhennaya, Udachnaya

Abstract: Garnet-(olivine) websterite xenoliths from the lithospheric mantle of the central and northeastern parts of the Siberian Craton contain exsolution microstructures after Si- and Ti-rich precursor garnets. We petrographically, geochemically, and thermobarometrically investigated 13 such xenoliths from the Mir, Obnazhennaya, and Udachnaya kimberlite pipes. All samples contain garnet grains with needle- to lamellae-shaped precipitates (up to 3.0?vol%), including Ti-oxide and/or pyroxene. Orthopyroxene and clinopyroxene grains host oriented lamellae of complementary Ca-rich and Ca-poor pyroxene, respectively, in addition to lamellae of garnet and Ti- and/or Cr-oxides. The common exsolution lamellae assemblages in garnet and pyroxene imply that exsolution occurred during cooling from high-temperature precursors. Exsolution is unlikely to have resulted from variations in pressure, given experimental and thermodynamic constraints. Host mineral partitioning of transition metal and lanthanide elements with different diffusivities record temperatures that range between those of local geotherms and a dry pyroxenite solidus. Inferred magmatic minimum temperatures of 1500-1700?°C satisfy the physical conditions predicted from experimental studies of the solubility of excess Si and Ti in garnet. Granular inclusions of all major minerals within each other imply an overlapping crystallisation history. The reconstructed compositions of the websterite whole-rocks have high MgO contents (15.7-35.7?wt%). A plot of MgO/SiO2 versus SiO2 forms an array, apart from the compositions of natural websterites that formed by interaction of peridotite with basaltic or siliceous melts. The array overlaps the compositional range of komatiite flows from Commondale and Barberton, South Africa, including spinifex, massive, and cumulate subtypes of komatiites. Other major and minor element abundances and ratios of the Siberian websterite suite resemble those of South African Al-enriched komatiites and are distinct from melt-rock reaction websterites. Therefore, the mineral microstructures and geochemistry of the Siberian websterites are suggestive of the former presence of a thermal anomaly. We propose that mantle plume activity or a similar form of lower-mantle ascent played a major role in stabilising cratonic nuclei before amalgamation of the present-day Siberian Craton.
DS1981-0082
1981
Spera, F.J.Bergman, S.C., Foland, K.A., Spera, F.J.On the Origin of an Amphibole Rich Vein in a Peridotite Inclusion from the Lunar Crater Volcanic Fields, Nevada, United States (us)Earth and Planetary Science Letters, Vol. 56, PP. 343-361.United States, NevadaGreat Basin, Mineral Chemistry
DS1984-0701
1984
Spera, F.J.Spera, F.J.Carbon Dioxide in Petrogenesis Iii: Role of Volatiles in The Ascent of Alkaline Magma with Special Reference to Xenolith Bearing Mafic Lavas.Contributions to Mineralogy and Petrology, Vol. 88, PP. 217-232.GlobalPetrogenesis, Mantle Metsomatism, Research, Kimberlite, Nepheline
DS1987-0709
1987
Spera, F.J.Spera, F.J.Dynamics of translithospheric migration of metasomatic fluid and alkalinemagmaIn: Mantle Metasomatism, edited M.A. Menzies, C.J. Hawkesworth, Academic, pp. 1-20GlobalBlank
DS1989-1149
1989
Spera, F.J.Oldenburg, C.M., Spera, F.J., Yuen, D.A., Sewell, G.Dynamic mixing in magma bodies: theory, simulations and implicationsJournal of Geophysical Research, Vol. 94, No. B7, July 10, pp. 9215-9236GlobalMagma, Genesis
DS1990-1479
1990
Spera, F.J.Trial, A.F., Spera, F.J.Mechanisms for the generation of compositional heterogeneities in magmachambersGeological Society of America (GSA) Bulletin, Vol. 102, No. 3, March pp. 353-367GlobalLayered intrusions, Experimental petrology
DS200712-1025
2006
Spera, F.J.Spera, F.J., Yuen, D.A., Giles, G.Tradeoffs in chemical and thermal variations in the post perovskite phase transition: mixed phase regions in the deep lower mantle?Physics of the Earth and Planetary Interiors, Vol. 159, 3-4, Dec. pp. 234-246.MantleGeothermometry
DS202201-0018
2022
Spera, F.J.Heinonen, J.S., Spera, F.J., Bohrson, W.A.Thermodynamic limits for assimilation of silicate crust in primitive magmas.Geology, Vol. 50, 1, pp. 81-85.Mantlemagmatism

Abstract: Some geochemical models for basaltic and more primitive rocks suggest that their parental magmas have assimilated tens of weight percent of crustal silicate wall rock. But what are the thermodynamic limits for assimilation in primitive magmas? We pursue this question quantitatively using a freely available thermodynamic tool for phase equilibria modeling of open magmatic systems—the Magma Chamber Simulator (https://mcs.geol.ucsb.edu)—and focus on modeling assimilation of wall-rock partial melts, which is thermodynamically more efficient compared to bulk assimilation of stoped wall-rock blocks in primitive igneous systems. In the simulations, diverse komatiitic, picritic, and basaltic parental magmas assimilate progressive partial melts of preheated average lower, middle, and upper crust in amounts allowed by thermodynamics. Our results indicate that it is difficult for any subalkaline primitive magma to assimilate more than 20?30 wt% of upper or middle crust before evolving to compositions with higher SiO2 than a basaltic magma (52 wt%). On the other hand, typical komatiitic magmas have thermodynamic potential to assimilate as much as their own mass (59?102 wt%) of lower crust and retain a basaltic composition. The compositions of the parental melt and the assimilant heavily influence both how much assimilation is energetically possible in primitive magmas and the final magma composition given typical temperatures. These findings have important implications for the role of assimilation in the generation and evolution of, e.g., ultramafic to mafic trans-Moho magmatic systems, siliceous high-Mg basalts, and massif-type anorthosites.
DS2000-0659
2000
Speranskii, A.V.Mineeva, R.M., Speranskii, A.V., Bao, Berhsov, et al.Diamond crystals from Peoples Republic of Chin a and electron spin resonance and cathodluminesence study.Geochemistry International, Vol. 38, No. 4, pp. 323-30.ChinaSpectrometry - ESR, CL, Deposit - Shenli, Shandong, Liaoning
DS200412-1317
2004
Speranskii, A.V.Mineeva, R.M., Speranskii, A.V., Titkov, S.V., Zhilicheva, O.M., Bershov, L.V., Bogatikov, O.A., KudryavtsevaSpectroscopic and morphological characteristics of diamonds from the Grib kimberlite pipe.Doklady Earth Sciences, Vol. 394, 1, Jan-Feb. pp. 96-99.Russia, Kola Peninsula, ArchangelDiamond morphology, deposit - Grib
DS1995-1265
1995
Speranskiy, A.V.Mineyeva, R.M., Speranskiy, A.V., Titkov, S.V., Bershov, L.V.A new type of paramagnetic centre based on nickel ions in natural diamondDoklady Academy of Sciences, Vol. 335A, No. 3, Nov., , pp. 143-147.RussiaDiamond morphology, Nickel
DS200712-0728
2007
Speransky, A.V.Mineeva, R.M., Speransky, A.V., Titkov, S.V., Solodova, Y.P., Samosorov, G.G.Paramagnetic N1 centre in plastically deformed and differently colored crystals of natural diamond.Doklady Earth Sciences, Vol. 415, 5, pp. 782-785.TechnologyDiamond morphology
DS200912-0501
2009
Speransky, A.V.Mineeva, R.M., Titkov, S.V., Speransky, A.V.Structural defects in natural plastically deformed diamonds: evidence from EPR spectroscopy.Geology of Ore Deposits, Vol. 51, 3, pp. 233-242.Russia, UralsSpectroscopy
DS201412-0932
2015
Speransky, A.V.Titkov, S.V., Mineeva, R.M., Zudina, N.N., Sergeev, A.M., Ryabchikov, I.D., Shiryaev, A.A., Speransky, A.V., Zhikhareva, V.P.The luminescent nature of orange coloration in natural diamonds: optical and EPR study.Physics and Chemistry of Minerals, Vol. 42, 2, pp. 131-141.TechnologyDiamond - spectroscopy
DS201503-0180
2015
Speransky, A.V.Titkov, S.V., Mineeva, R.M., Zudina, N.N., Sergeev, A.M., Ryabchikov, I.D., Shiryaev, A.A., Speransky, A.V., Zhikhareva, V.P.The luminescent nature of orange coloration in natural diamonds: optical and EPR study.Physics and Chemistry of Minerals, Vol. 42, 2, pp. 131-144.TechnologyDiamond Colour
DS201608-1444
2016
Speransky, A.V.Titkov, S.V., Mineeva, R.M., Ryabchikov, I.D., Speransky, A.V.Sites of N1 nitrogen paramagnetic centers in natural diamond crystals: disssymmetrization of the structure as a result of plastic deformation.Doklady Earth Sciences, Vol. 468, 1., pp. 500-502.RussiaMorphology - brown diamonds
DS1930-0283
1938
Spereisen, F.J.Spereisen, F.J.Gem Minerals of CaliforniaCalifornia Division of Mines Report, No. 34, PP. 34-78.California, West CoastDiamonds
DS2001-1110
2001
Sperner, B.Sperner, B., Lorenz, F., Hettel, Muller, B., Wenzel, F.Slab break off abrupt cut or gradual detachment? New insights from Vrancea region (southeast Carpathians).Terra Nova, Vol. 13, pp. 172-79.RomaniaSubduction - slab, Tectonics
DS201808-1777
2018
Sperner, B.Pflander, J.A., Jung, S., Klugel, A., Munker, C., Romer, R.L., Sperner, B., Rohrmuller, J.Recurrent local melting of metasomatised lithospheric mantle in response to continental rifting: constraints from basanites and nephelinites/melilitites from SE Germany.Journal of Petrology, Vol. 59, 4, pp. 667-694.Europe, Germanymelilitites

Abstract: Cenozoic primitive basanites, nephelinites and melilitites from the Heldburg region, SE Germany, are high-MgO magmas (8•5-14•1?wt % MgO), with low SiO2 (34•2-47•1?wt %) and low to moderately high Al2O3 (9•0-15•5?wt %) and CaO (8•7-12•7?wt %). The Ni and Cr contents of most samples are up to 470?ppm and 640?ppm, respectively, and match those inferred for primary melts. In multi-element diagrams, all samples are highly enriched in incompatible trace elements with chondrite-normalised La/Yb?=?19-45, strongly depleted in Rb and K, with primitive mantle normalised K/La?=?0•15-0•72, and moderately depleted in Pb. The initial Sr-Nd-Hf isotope compositions (87Sr/86Sr?=?0•7033-0•7051, 143Nd/144Nd?=?0•51279-0•51288 and 176Hf/177Hf?=?0•28284-0•28294) fall within the range observed for other Tertiary volcanic rocks of the Central European Volcanic Province, whereas 208Pb/204Pb and 206Pb/204Pb (38•42-38•88 and 18•49-18•98) are distinctly lower at comparable 207Pb/204Pb (15•60-15•65). Trace element modelling and pressure-temperature estimates based on major element compositions and experimental data suggest that the nephelinites/melilitites formed within the lowermost lithospheric mantle, close to the lithosphere-asthenosphere boundary, by ?3-5% partial melting of a highly enriched, metasomatised, carbonated phlogopite-bearing garnet-lherzolite at temperatures?<1250?°C and pressures of ?2•8?GPa. This corresponds to a melting depth of less than ?85?km. Formation and eruption of these magmas, based on 40Ar/39Ar dating, started in the late Eocene (38•0 Ma) and lasted until the late Oligocene (25•4 Ma). Basanite eruptions occurred in the same area in the middle Miocene, about 7•7 Myr after nephelinite/melilitite generation has ceased, and lasted from 17•7 to 13•1 Ma. The basanites were generated at lower pressures (2•2-1•7?GPa) at similar temperatures (?1220-1250?°C) within the spinel stability field in the lithospheric mantle by 2-6% partial melting. Isotope and trace element systematics indicate that the lithospheric mantle source of the Heldburg magmas was affected by metasomatism associated with long-lasting subduction of oceanic and continental crust during the Variscan orogeny. Aqueous or supercritical fluids that formed at temperatures?<1000?°C and pressures of likely?>4?GPa infiltrated the thermal boundary layer at the base of the lithospheric mantle and imprinted a crustal lead isotope, and to a minor extent crustal Sr, Nd and Hf isotope signatures. They also reduced Nb/U, Ce/Pb, Lu/Hf, Sm/Nd, U/Pb and Th/Pb, but increased Rb/Sr and Nb/Ta and amplified the enrichment of LILE and LREE relative to HREE. This lead to the highly-enriched trace element patterns observed in both sample suites, and to overall less radiogenic 206Pb/204Pb and 208Pb/204Pb compared to other continental basalts in Central Europe, and to less radiogenic 176Hf/177Hf and 143Nd/144Nd that plot distinctly below the terrestrial mantle array. Temporal evolution of magmatism in the Heldburg region coincides with the changing Tertiary intraplate stress field in Central Europe, which developed in response to the Alpine orogeny. Magmatism was most probably caused in response to lithosphere deformation and perturbation of the thermal boundary layer, and not by actively upwelling asthenosphere.
DS1975-0628
1977
Spero, S.A.Spero, S.A.Diamonds, Love and Compatibility. (so You Think You've Got A Gem!).Hicksville, New York: Exposition Press, 119P.GlobalKimberlite, Kimberley
DS1975-0829
1978
Sperr, J.T.Ogden, P.R.JR., Sperr, J.T., Gunter, W.D.Morphology of a Recent Ultrapotassic Volcanic Field, Leucite Hills, Southwestern Wyoming.Geological Society of America (GSA), Vol. 10, No. 3, P. 140, (abstract.).GlobalRocky Mountains, Leucite Hills, Leucite
DS1920-0471
1929
Sperry, A.B.Sperry, A.B.The Intrusive Rocks of Riley County, KansasKansas Acad. Science Transactions, Vol. 32, ABSTRACT ONLY.United States, Kansas, Central StatesBlank
DS1992-1080
1992
Sperry, D.R.Moison, D.L., Sperry, D.R.Influence of production costs and inventories on mineral pricesNatural Resources forum, November pp. 271-276GlobalEconomics, Industrial minerals
DS201510-1758
2015
Spetisus, Z.V.Ashchepkov, I.V., Logvinova, A.M., Reimers, L.F., Ntaflos, T., Spetisus, Z.V., Vladykin, N.V., Downes, H., Yudin, D.S., Travin, A.V., Makovchuk, I.V., Palesskiy, V.S., KhmelNikova, O.S.The Sytykanskaya kimberlite pipe: evidence from deep seated xenoliths and xenocrysts for the evolution of the mantle beneath Alakit, Yakutia, Russia.Geoscience Frontiers, Vol. 6, 5, pp. 687-714.Russia, YakutiaDeposit - Sytykanskaya

Abstract: Mantle xenoliths (>150) and concentrates from late autolithic breccia and porphyritic kimberlite from the Sytykanskaya pipe of the Alakit field (Yakutia) were analyzed by EPMA and LAM ICP methods. In P-T-X-f(O2) diagrams minerals from xenoliths show widest variations, the trends P-Fe#-CaO, f(O2) for minerals from porphyric kimberlites are more stepped than for xenocrysts from breccia. Ilmenite PTX points mark moving for protokimberlites from the lithosphere base (7.5 GPa) to pyroxenite lens (5-3.5 GPa) accompanied by Cr increase by AFC and creation of two trends P-Fe#Ol ?10-12% and 13-15%. The Opx-Gar-based mantle geotherm in Alakit field is close to 35 mW/m2 at 65 GPa and 600 °C near Moho was determined. The oxidation state for the megacrystalline ilmenites is lower for the metasomatic associations due to reduction of protokimberlites on peridotites than for uncontaminated varieties at the lithosphere base. Highly inclined linear REE patterns with deep HFSE troughs for the parental melts of clinopyroxene and garnet xenocrysts from breccia were influenced by differentiated protokimberlite. Melts for metasomatic xenoliths reveal less inclined slopes without deep troughs in spider diagrams. Garnets reveal S-shaped REE patterns. The clinopyroxenes from graphite bearing Cr-websterites show inclined and inflected in Gd spectrums with LREE variations due to AFC differentiation. Melts for garnets display less inclined patterns and Ba-Sr troughs but enrichment in Nb-Ta-U. The 40Ar/39Ar ages for micas from the Alakit mantle xenoliths for disseminated phlogopites reveal Proterozoic (1154 Ma) age of metasomatism in early Rodinia mantle. Veined glimmerites with richterite - like amphiboles mark ?1015 Ma plume event in Rodinia mantle. The ?600-550 Ma stage manifests final Rodinia break-up. The last 385 Ma metasomatism is protokimberlite-related.
DS1990-1155
1990
Spetius, Z.V.Pankov, V.Yu., Spetius, Z.V.Iron silicide and native silicon inclusions in moissanite from the Sytykan kimberlite pipeDoklady Academy of Science USSR, Earth Science Section, Vol. 305, No. 2, Sept. pp. 152-155RussiaKimberlite, Moissanite
DS2001-1111
2001
Spetius, Z.V.Spetius, Z.V.A xenolith of high temperature Diamondiferous peridotites from the Udachnaya kimberlite pipe.Doklady Academy of Sciences, Vol. 379, No. 5, June-July pp. 550-2.Russia, SiberiaXenolith - petrology, Deposit - Udachnaya
DS2002-1531
2002
Spetius, Z.V.Spetius, Z.V., Belousova, Griffin, O'Reilly, PearsonArchean sulphide inclusions in Paleozoic zircon megacrysts from the Mir kimberlite: implications datingEarth and Planetary Science Letters, Vol.199,1-2,pp.111-26., Vol.199,1-2,pp.111-26.Russia, YakutiaGeochronology - dating of diamonds, Deposit - Mir
DS2002-1532
2002
Spetius, Z.V.Spetius, Z.V., Belousova, Griffin, O'Reilly, PearsonArchean sulphide inclusions in Paleozoic zircon megacrysts from the Mir kimberlite: implications datingEarth and Planetary Science Letters, Vol.199,1-2,pp.111-26., Vol.199,1-2,pp.111-26.Russia, YakutiaGeochronology - dating of diamonds, Deposit - Mir
DS200812-1101
2008
Spetius, Z.V.Spetius, Z.V., Taylor, L.A.Diamonds of Siberia. Photographic evidence for their origin. Excellent photography ...Tranquility Base Press, P.O. Box 473, Lenoir City, TN 37771 USA, goodbook @tranquility basepress.com US $ 92.00Russia, SiberiaBook - diamond genesis
DS201012-0394
2009
Spetius, Z.V.Klein-BenDavid, O., Logvinova, A.M., Schrauder, M., Spetius, Z.V., Weiss, Hauri, Kaminsky, Sobolev, Navon, O.High Mg carbonatitic Micro inclusions in some Yakutian diamonds - a new type of diamond forming fluid.Lithos, Vol. 112 S pp. 648-659.RussiaMineral chemistry - end member
DS201612-2276
2016
Spetius, Z.V.Ashchepkov, I.V., Ntaflos, T., Spetius, Z.V., Salikhov, R.F., Downes, H.Interaction between protokimberlite melts and mantle lithosphere: evidence from mantle xenoliths from the Dalnyaya kimberlite pipe, Yakutia, Russia.Geoscience Frontiers, in press availableRussia, YakutiaDeposit - Dalnyaya

Abstract: The Dalnyaya kimberlite pipe (Yakutia, Russia) contains mantle peridotite xenoliths (mostly lherzolites and harzburgites) that show both sheared porphyroclastic (deformed) and coarse granular textures, together with ilmenite and clinopyroxene megacrysts. Deformed peridotites contain high-temperature Fe-rich clinopyroxenes, sometimes associated with picroilmenites, which are products of interaction of the lithospheric mantle with protokimberlite related melts. The orthopyroxene-derived geotherm for the lithospheric mantle beneath Dalnyaya is stepped similar to that beneath the Udachnaya pipe. Coarse granular xenoliths fall on a geotherm of 35 mWm?2 whereas deformed varieties yield a 45 mWm?2 geotherm in the 2-7.5 GPa pressure interval. The chemistry of the constituent minerals including garnet, olivine and clinopyroxene shows trends of increasing Fe# (=Fe/(Fe + Mg)) with decreasing pressure. This may suggest that the interaction with fractionating protokimberlite melts occurred at different levels. Two major mantle lithologies are distinguished by the trace element patterns of their constituent minerals, determined by LA-ICP-MS. Orthopyroxenes, some clinopyroxenes and rare garnets are depleted in Ba, Sr, HFSE and MREE and represent relic lithospheric mantle. Re-fertilized garnet and clinopyroxene are more enriched. The distribution of trace elements between garnet and clinopyroxene shows that the garnets dissolved primary orthopyroxene and clinopyroxene. Later high temperature clinopyroxenes related to the protokimberlite melts partially dissolved these garnets. Olivines show decreases in Ni and increases in Al, Ca and Ti from Mg-rich varieties to the more Fe-rich, deformed and refertilized ones. Minerals showing higher Fe# (0.11-0.15) are found within intergrowths of low-Cr ilmenite-clinopyroxene-garnet related to the crystallization of protokimberlite melts in feeder channels. In P-f(O2) diagrams, garnets and Cr-rich clinopyroxenes indicate reduced conditions at the base of the lithosphere at ?5 log units below a FMQ buffer. However, Cr-poor clinopyroxenes, together with ilmenite and some Fe-Ca-rich garnets, demonstrate a more oxidized trend in the lower part of lithosphere at ?2 to 0 log units relative to FMQ. Clinopyroxenes from xenoliths in most cases show conditions transitional between those determined for garnets and megacrystalline Cr-poor suite. The relatively low diamond grade of Dalnyaya kimberlites is explained by a high degree of interaction with the oxidized protokimberlite melts, which is greater at the base of the lithosphere.
DS201707-1371
2017
Spetius, Z.V.Spetius, Z.V., Cliff, J., Griffin, W.L., O'Reilly, S.Y.Carbon isotopes of eclogite hosted diamonds from the Nyurbinskaya kimberlite pipe, Yakutia: the metasomatic origin of diamonds.Chemical Geology, Vol. 455, pp. 131-147.Russia, Yakutiadeposit - Nyurbinskaya

Abstract: Carbon isotope compositions and the distribution of nitrogen and hydrogen in diamonds from 18 eclogites from Nurbinskaya kimberlites were studied in situ in polished plates. Cathodoluminescence images show that most of the diamonds have complex growth structures with distinctive core, intermediate and rim zones. In some diamonds the cores display dissolution features, and intermediate growth zones are separated from the cores by narrow rounded oscillatory zones. At least three crystals show interrupted multistage diamond growth; variations in ?13C of 2–3‰ occur across the contacts between distinct zones. Generally, ?13C within the diamond cores varies only by 1–2‰, in rare cases up to 3.3‰. ?13C values are usually lower in the intermediate zones and drop further towards the rims by up to 3‰. High-resolution SIMS profiles show that variations in ?13C across the diamond growth zones are sharp with no evidence of diffusive relaxation. Diamonds with predominantly tangential octahedral growth have a wide range in ?13C from ? 15.2‰ up to 9.0‰ (± 0.4‰), and their nitrogen (N) contents vary between 30 and 1500 at. ppm. Six diamonds show little internal variation along the isotopic profiles with changes in ?13C of only 0.3–0.9‰ around mean values ranging from ? 6‰ to ? 3‰. Five crystals are isotopically heavy, with relatively homogeneous ?13C up to 9‰. FTIR data show markedly different N concentrations and nitrogen aggregation states between major growth zones. This implies that the diamonds in eclogitic xenoliths from Nyurbinskaya pipe grew in multiple and interrupted growth events, probably from fluids enriched in K and H. The wide variations of ?13C in the studied eclogitic diamonds and identification of their anomalously positive ?13C values, combined with the wide range of high ?18O in garnets from the diamondiferous xenoliths of the Nyurbinskaya pipe, which are mostly outside of the mantle range, suggest a crustal contribution to the parental mantle-related fluids forming diamonds in these xenoliths and indicate the complex metasomatic evolution of the lithospheric mantle beneath the Nakynsky kimberlite field.
DS201803-0433
2017
Spetius, Z.V.Ashchepekov, I.V., Ntaflos, T., Logvinova, A.M., Spetius, Z.V., Downes, H.Monomineral universal clinopyroxene and garnet barometers for peridotitic, eclogitic and basaltic systems.Geoscience Frontiers, Vol. 8, pp. 775-795.Mantlegeobarometry

Abstract: New versions of the universal Jd-Di exchange clinopyroxene barometer for peridotites, pyroxenites and eclogites, and also garnet barometer for eclogites and peridotites were developed. They were checked using large experimental data sets for eclogitic (?530) and peridotitic systems (>650). The precision of the universal Cpx barometer for peridotites based on Jd-Di exchange is close to Cr-Tschermakite method produced by Nimis and Taylor (2000). Cpx barometer was transformed by the substitution of major multiplier for KD by the equations dependent from Al-Na-Fe. Obtained equation in combination with the thermometer of Nimis and Taylor (2000) allow to reconstruct position of the magma feeder systems of the alkali basaltic magma within the mantle diapirs in modern platforms like in Vitim plateau and other Southern Siberia localities and several localities worldwide showing good agreement of pressure ranges for black and green suites. These equations allow construct PTX diagrams for the kimberlite localities in Siberia and worldwide calculating simultaneously the PT parameters for different groups of mantle rocks. They give very good results for the concentrates from kimberlite lamproites and placers with mantle minerals. They are useful for PT estimates for diamond inclusions. The positions of eclogite groups in mantle sections are similar to those determined with new Gar–Cpx barometer produced by C. Beyer et al. (2015). The Fe rich eclogites commonly trace the boundary between the lower upper parts of subcontinental lithospheric mantle (SCLM) at 3–4 GPa marking pyroxenite eclogites layer. Ca-rich eclogites and especially grospydites in SCLM beneath Precambrian kimberlites occurs near pyroxenite layer but in younger mantle sections they became common in the lower parts. The diamondiferous Mg Cr-less group eclogites referring to the ancient island arc complexes are also common in the middle part of mantle sections and near 5–6 GPa. Commonly eclogites in lower apart of mantle sections are remelted and trace the high temperature convective branch. The Mg- and Fe-rich pyroxenites also show the extending in pressure trends which suggest the anatexic melting under the influence of volatiles or under the interaction with plums.
DS202003-0330
2019
Spetius, Z.V.. KislovBadukhinov, L.D., Spetius, Z.V.. Kislov, E.V., Ivanov, A.S., Monkhorov, R.V.Parageneses of garnet inclusions in diamonds from Yakutia kimberlites based on Raman and IR spectroscopy data. Udachnaya, Zapolyarnaya, Komolskaya, Yuibeyana, Aikhal, Mir, Mayskaya.Geology of Ore Deposits, Vol. 61, 7, pp. 606-612. pdfRussia, Yakutiadiamond inclusions
DS2001-0897
2001
SpetsiusPearson, N.J., Griffin, Spetsius, O'ReillyIn situ Re Os analysis of mantle sulphides: a new microanalytical technique to unravel the evolution...Slave-Kaapvaal Workshop, Sept. Ottawa, 6p. abstractRussia, Siberia, YakutiaGeochronology, Deposit - Udachnaya
DS201112-0639
2011
SpetsiusMalkovets, V.G., Griffin, Pearson, Rezvukhin, O'Reilly, Pokhilenko, Garanin, Spetsius, LitasovLate metasomatic addition of garnet to the SCLM: Os-isotope evidence.Goldschmidt Conference 2011, abstract p.1395.RussiaUdachnaya, Daldyn
DS200412-1050
2004
Spetsius, N.V.A.Kostrovskii, S.J., Spetsius, N.V.A., Suvorova, L.F.Clinopyroxene olivine ilmenite megacryst assemblage in kimberlite from the Udachnaya pipe.Doklady Earth Sciences, Vol. 396, 4, May-June, pp. 504-507.Russia, YakutiaPetrology
DS2003-1020
2003
Spetsius, S.Nowell, G.M., Pearson, D.G., Jacob, D.E., Spetsius, S., Nixon, P.H., HaggertyThe origin of alkremites and related rocks: a Lu Hf Rb Sr and Sm Nd isotope study8ikc, Www.venuewest.com/8ikc/program.htm, Session 4, POSTER abstractRussia, YakutiaMantle geochemistry, Deposit - Udachnaya
DS201312-0336
2013
Spetsius, S.Griffin, W.L., Belousova, E.A., O'Neill, C., O'Reilly, S.Y., Malkovets, V., Pearson, N.J., Spetsius, S., Wilde, S.A.The world turns over: Hadean-Archean crust mantle evolution.Lithos, Vol. 189, pp. 2-15.MantleCrust- mantle review
DS2003-1014
2003
Spetsius, V.Z.Nikiforava, A., Bobrov, A.V., Spetsius, V.Z.Garnet clinopyroxene assemblage of mantle rocks from the Obnazhennaya kimberlite8ikc, Www.venuewest.com/8ikc/program.htm, Session 2, POSTER abstractRussia, YakutiaEclogites and Diamonds, Deposit - Obnazhennaya
DS200612-1344
2005
Spetsius, V.Z.Spetsius, Z.V., Spetsius, V.Z.Exsolution textures and minerals In homogeneity in xenoliths from Yakutian kimberlites: evidence for the mantle evolution.Problems of Sources of deep magmatism and plumes., pp. 148-169.Russia, YakutiaMineral chemistry
DS1986-0779
1986
Spetsius, X.V.Spetsius, X.V., Nikishov, K.N., Makhoto, V.F.Kyanite eclogite with sanidine from the Udachnaya kimberlite pipeDoklady Academy of Sciences Acad. Science USSR Earth Science Section, Vol. 279, No. 1-6, pp. 138-141South AfricaMineral chemistry, Roberts Victor, Analyses sanidine eclogit
DS1986-0780
1986
Spetsius, Z.Spetsius, Z., Safronov, A.F.Some compositional; characteristics of rutile in eclogitic associations and those in paragenesis with diamond.(Russian)Zap. Vses. Mineral O-Va, (Russian), Vol. 115, No. 6, pp. 699-705RussiaParagenesis
DS1994-1495
1994
Spetsius, Z.Rudnick, R.L., Spetsius, Z.Trace elements in diamond inclusions from eclogites reveal link to Archeangranites.Earth Planetary Science Letters, Vol. 128, No. 3-4, Dec. pp. 199-214.IrelandDiamond inclusions, Eclogites
DS2003-0620
2003
Spetsius, Z.Ionov, D., Spetsius, Z., Weiss, D., Bodinier, J.L.Hf Nd Sr isotope and trace element evidence for a diversity of origins of rutile bearingGeological Association of Canada Annual Meeting, Abstract onlyRussia, SiberiaGeochronology, Eclogite
DS200412-0872
2003
Spetsius, Z.Ionov, D., Spetsius, Z., Weiss, D., Bodinier, J.L.Hf Nd Sr isotope and trace element evidence for a diversity of origins of rutile bearing eclogite xenoliths from the Siberian CrGeological Association of Canada Annual Meeting, Abstract onlyRussia, SiberiaGeochronology Eclogite
DS201012-0743
2010
Spetsius, Z.Spetsius, Z.Environment of diamonds in eclogites from kimberlites ( Yakutia): application to their genesis.International Mineralogical Association meeting August Budapest, AbstractRussiaDiamond genesis
DS201412-0876
2014
Spetsius, Z.Spetsius, Z.Metasomatic diamonds in eclogite xenoliths from Yakutian kimberlites: implications for diamond grade estimation.ima2014.co.za, AbstractRussia, YakutiaDiamond grade
DS201502-0040
2015
Spetsius, Z.Ashchepkov, I., Ntaflos, T., Spetsius, Z.Trace element study of the xenoliths study of the mantle xenoliths from Sytykanskaya pipe, Yakutia.Economic Geology Research Institute 2015, Vol. 17,, # 2624, 1p. AbstractRussiaDeposit - Sytykanskaya
DS201612-2274
2016
Spetsius, Z.Ashchepkov, I.V., Logvinova, A.M., Ntaflos, T., Vladykin, N.V., Kostrovitsky, S.I., Spetsius, Z., Mityukhin, S.I., Prokopyev, S.A., Medvedev, N.S., Downe, H.Alakit and Daldyn kimberlite fields, Siberia, Russia: two types of mantle sub-terranes beneath central Yakutia?Geoscience Frontiers, in press availableRussia, SiberiaDeposit - Alakit, Daldyn

Abstract: Mineral data from Yakutian kimberlites allow reconstruction of the history of lithospheric mantle. Differences occur in compositions of mantle pyropes and clinopyroxenes from large kimberlite pipes in the Alakit and Daldyn fields. In the Alakit field, Cr-diopsides are alkaline, and Stykanskaya and some other pipes contain more sub-calcic pyropes and dunitic-type diamond inclusions, while in the Daldyn field harzburgitic pyropes are frequent. The eclogitic diamond inclusions in the Alakit field are sharply divided in types and conditions, while in the Daldyn field they show varying compositions and often continuous Pressure-Temperature (P-T) ranges with increasing Fe# with decreasing pressures. In Alakit, Cr-pargasites to richterites were found in all pipes, while in Daldyn, pargasites are rare Dalnyaya and Zarnitsa pipes. Cr-diopsides from the Alakit region show higher levels of light Rare Earth Elements (LREE) and stronger REE-slopes, and enrichment in light Rare Earth Elements (LREE), sometimes Th-U, and small troughs in Nb-Ta-Zr. In the Daldyn field, the High Field Strength Elements HFSE troughs are more common in clinopyroxenes with low REE abundances, while those from sheared and refertilized peridotites have smooth patterns. Garnets from Alakit show HREE minima, but those from Daldyn often have a trough at Y and high U and Pb. PTXfO2 diagrams from both regions show similarities, suggesting similar layering and structures. The degree of metasomatism is often higher for pipes which show dispersion in P-Fe# trends for garnets. In the mantle beneath Udachnaya and Aykhal, pipes show 6-7 linear arrays of P-Fe# in the lower part of the mantle section at 7.5-3.0 GPa, probably reflecting primary subduction horizons. Beneath the Sytykanskaya pipe, there are several horizons with opposite inclinations which reflect metasomatic processes. The high dispersion of the P-Fe# trend indicating widespread metasomatism is associated with decreased diamond grades. Possible explanation of the differences in mineralogy and geochemistry of the mantle sections may relate to their tectonic positions during growth of the lithospheric keel. Enrichment in volatiles and alkalis possibly corresponds to interaction with subduction-related fluids and melts in the craton margins. Incorporation of island arc peridotites from an eroded arc is a possible scenario.
DS201705-0808
2017
Spetsius, Z.Ashchepkov, I., Ntaflos, T., Logvinova, A., Vladykin, N., Ivanov, A., Spetsius, Z., Stegnitsky, Y., Kostrovitsky, S., Salikhov, R., Makovchuk, I., Shmarov, G., Karpenko, M., Downes, H., Madvedev, N.Evolution of the mantle sections beneath the kimberlite pipes example of Yakutia.European Geosciences Union General Assembly 2017, Vienna April 23-28, 1p. 6337 AbstractRussia, YakutiaDeposit - Sytykanskaya, Dalnyaya, Aykhal, Zarya, Komosomolskaya, Zarnitsa, Udachnaya

Abstract: The PTX diagrams for the separate phases in Sytykanskaya (Ashchepkov et al., 2016) Dalnyaya (Ashchepkov et al., 2017), pipes shows that the PK show the relatively simple P-X trends and geotherms and shows more contrast and simple layering. The PK contain most abundant material from the root of the magma generation they are dunitic veins as the magma feeders represented by the megacrysts. New results for the Aykhal, Zarya and Komsomolskaya pipes in Alake field and Zarnitsa and Udachnaya pipes in Daldyn field show that evolution is accompanied by the developing of metasomatites and branching and veining of the wall rock peridotites . In Aykhal pipe in PK the Gar- dunites prevail, the xenoliths from the dark ABK "Rebus" contain Cr-Ti - rich garnets and ilmenites, more abundant compared with the grey carbonited breccia Nearly the same features were found for Yubileinaya pipe. The example of Komsomolskya pipes show that the ABK contain more eclogitic xenolith than PK. The developing of the magma channel shown in satellite Chukukskaya and Structurnaya pipe was followed by the separation of some parts of the magmatic feeders and crystallization of abundant Gar megacrysts near o the walls blocking the peridotites from the magma feeder. This drastically decrease diamond grade of pipes. Such blocking seems to be the common features for the latest breccias. In Zarnitsa pipe, the dark PK and ABK also contain fresh xenoliths but not only dunites but also sheared and metasomatic varieties and eclogites. Most of dark ABK in Yakutia contain the intergrowth of ilmenites with brown Ti- Cpx showing joint evolution trends. The late breccia contains completely altered peridotite xenoliths mainly of dunite- harzburgite type. The comparison of the trace elements of the coexisting minerals in megacryst show that they were derived from the protokimberlites but are not in complete equilibrium as well as other megacrystalline phases. Ilmenites show inflections of the trace element patterns of most Ilmenites but more regular for the Cpx and Garnets revealing the sub parallel patterns elevating LREE with the rising TRE. But commonly these are not continuous sequances because they developed in the pulsing moving systems like beneath Zarnitsa. The minerals from the feeders like dunites also show the inflected or S-type REE patterns. From the earlier to later phases the TRE compositions became more evolved reflecting the evolution of protokimberlites. The wall rocks also often show the interaction with the more evolved melts and sometimes "cut" spectrums due to the dissolution some phases and repeated melting events So we could suggest the joint evolution of the mantle column protokimberlites and megacrysts composition and type of kimberlites with the diamond grade. The mantle lithospheric base captured by the PK. The developing and rising protokimbelrites was followed by the crystallization of the diamonds in the gradient in FO2 zone in wall rocks due to reductions of C -bearing fluids and carbonatites (> 1 QMF) on peridotites ((< -2 -5 QMF). The most intensive reactions are near the graphite - diamond boundary where protokimberlites are breaking and where most framesites are forming.
DS2003-1366
2003
Spetsius, Z.A.Taylor, L.A., Spetsius, Z.A., Wiesli, R., Anand, M., Promprated, P., Valley, J.The origin of mantle peridotites: crustal signatures from Yakutian kimberlites8ikc, Www.venuewest.com/8ikc/program.htm, Session 4, POSTER abstractRussia, YakutiaMantle geochemistry
DS1981-0392
1981
Spetsius, Z.V.Spetsius, Z.V., Ponomarenko, A.I.Vitrified Eclogite, Representative of the Earth's Asthenosphere.Doklady Academy of Science USSR, Earth Science Section., Vol. 248, No. 1-6, PP. 115-118.RussiaBlank
DS1981-0393
1981
Spetsius, Z.V.Spetsius, Z.V., Zayachkovskiy, A.A., Gorokhov, S.S.Discovery of a Diamond Dniester Type in Eclogite Xenoliths with Some placers.Mineral. Sbornik L'vov, Vol. 35, No. 1, PP. 71-73.RussiaBlank
DS1982-0501
1982
Spetsius, Z.V.Ponomarenko, A.I., Spetsius, Z.V.Mineral Rims on Diamonds from KimberlitesInternational Geology Review, Vol. 24, No. 7, PP. 829-834.RussiaEvaluation, Carbonate, Genesis, Analyses, Microprobe, Crystallography
DS1982-0502
1982
Spetsius, Z.V.Ponomarenko, A.I., Spetsius, Z.V., Sobolev, N.V.New Type of Diamond Bearing Rock- Garnet PyroxeniteDoklady Academy of Science USSR, Earth Science Section., Vol. 251, No. 2, PP. 89-91.RussiaPetrography
DS1984-0702
1984
Spetsius, Z.V.Spetsius, Z.V., Nikishov, K.N., Makhotko, V.F.Sanidine bearing kyanite eclogites from the Udachnayakimberlitepipe.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 279, No. 1, pp. 177-180RussiaEclogite, Sanidine
DS1984-0703
1984
Spetsius, Z.V.Spetsius, Z.V., Nikishov, K.N., Makhotko, V.F.Sanidine Bearing Kyanite Eclogite from Kimberlite Pipe Udachnaia.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 279, No. 1, PP. 177-180.RussiaInclusions
DS1986-0116
1986
Spetsius, Z.V.Bulanova, G.P., Spetsius, Z.V.Paragenesis and pecularities of sulphides in diamonds and mantle xenoliths from kimberlitesProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 374-376RussiaDiamond morphology
DS1986-0781
1986
Spetsius, Z.V.Spetsius, Z.V., Nikishov, K.N., Makhotko, V.F.Kyanite eclogite with sanadine from the Udachnaya kimberlite pipeDoklady Academy of Science USSR, Earth Science Section, Vol. 279, No. 1-6, pp. 138-141RussiaEclogite
DS1988-0627
1988
Spetsius, Z.V.Serenko, V.P., Spetsius, Z.V.Petrochemical model of the earth crust in kimberlitic magmatism regions ofYakutia.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 299, No. 2, pp. 471-476RussiaBlank
DS1988-0660
1988
Spetsius, Z.V.Spetsius, Z.V., Bulanova, G.P.Native iron in diamond bearing eclogite from the Udachnaya kimberliteDoklady Academy of Science USSR, Earth Science Section, Vol. 294, No. 1-6, October pp. 144-146RussiaEclogite, Iron
DS1988-0661
1988
Spetsius, Z.V.Spetsius, Z.V., Bulanova, G.P., Leskova, N.V.Djerfisherite and its genesis in kimberlitic rocksDoklady Academy of Science USSR, Earth Science Section, Vol. 293, No. 1-6, September pp. 133-136RussiaDjerfisherite
DS1989-1170
1989
Spetsius, Z.V.Pankov, V.I., Spetsius, Z.V.Inclusions of iron silicates and native silicon in moissanite from the Sytykanskaia kimberlite pipe.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 305, No. 3, pp. 704-707RussiaDiamond inclusions, Moissanite
DS1990-0253
1990
Spetsius, Z.V.Bulanova, G.P., Spetsius, Z.V.Inclusion in diamond and minerals of mantle xenoliths from kimberlites as A source of information on the upper mantle compositionInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 2, extended abstract p. 784-785RussiaDiamond morphology, Diamond inclusions
DS1990-1402
1990
Spetsius, Z.V.Spetsius, Z.V.Geological and technological assessment of primary diamond depositsInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 2, extended abstract p. 1004-1005RussiaBrief -overview, Listing of reasons
DS1990-1403
1990
Spetsius, Z.V.Spetsius, Z.V.Megaxenolith of coesite eclogite from the Udachnaya kimberlite pipe.(Russian)Dokl. Akad., Nauk SSSR, (Russian), Vol. 312, No. 1, pp. 153-147RussiaCoesite Udachnaya, Eclogite
DS1990-1404
1990
Spetsius, Z.V.Spetsius, Z.V.Diamond bearing xenolith of garnet peridotite from the Mir kimberlitepipe.(Russian)Dokl. Akad.Nauk SSSR, (Russian), Vol. 313, No. 4, pp. 939-943RussiaDiamond inclusions, Garnet peridotite
DS1990-1405
1990
Spetsius, Z.V.Spetsius, Z.V., Bulanova, G.P.First find of sulphides in contact with diamonds in eclogite xenoliths From the Udachnaya pipeDoklady Academy of Sciences USSR, Earth Sci. Section, Vol. 306, No. 3, pp. 83-87RussiaDiamond inclusions, Sulphides
DS1990-1442
1990
Spetsius, Z.V.Talnikova, S.B., Spetsius, Z.V., Pavlova, L.A.Characteristics of the phase composition of sulfide inclusions in garnets from the Udachnaya kimberlite pipe. (Russian)Mineral. Zhurn., (Russian), Vol. 12, No. 6, pp. 44-51Russia, YakutiaDiamond inclusions, Garnets
DS1991-0817
1991
Spetsius, Z.V.Kadik, A.A., Zharkova, Y.Y., Spetsius, Z.V.Redox conditions of the formation of diamond bearing kyanites of eclogites(kimberlite pipe Udachnaya, Yakutia).(Russian)Dan. SSSR, (Russian), Vol. 320, No. 2, pp. 440-444Russia, YakutiaEclogites, kyanites, Diamonds
DS1991-1647
1991
Spetsius, Z.V.Spetsius, Z.V.Megaxenolith of coesite eclogite from the Udachnaya kimberlite pipeDoklady Academy of Sciences USSR Earth Sci. Section, Vol. 313, No. 1, pp. 187-190Russia, YakutiaCoesite, eclogite, Deposit -Udachnaya
DS1992-1458
1992
Spetsius, Z.V.Spetsius, Z.V.A diamond bearing xenolith of garnet peridotite from the Mir kimberlitepipeDoklady Academy of Science USSR, Earth Science Section, Vol. 313, No. 106, June pp. 200-203Russia, YakutiaDiamonds, Mir
DS1992-1459
1992
Spetsius, Z.V.Spetsius, Z.V.A review of the Diamondiferous eclogite xenoliths from kimberlite pipes ofYakutia: implications for diamond genesisProceedings of the 29th International Geological Congress. Held Japan August 1992, Vol. 1, abstract p. 179Russia, YakutiaEclogite, Diamond genesis
DS1992-1460
1992
Spetsius, Z.V.Spetsius, Z.V.The Yakutian kimberlite Province of the East Siberian CratonInternational Geology Review, Vol. 34, No. 4, April pp. 399-411.Russia, YakutiaKimberlite, Craton
DS1993-1438
1993
Spetsius, Z.V.Sharonova. Z.V., Pechersk, D.M., Spetsius, Z.V.Paleomagnetic examination of the serpentinization stage of kimberlites and xenoliths from the Udachnaya pipe.(Russian)Fizik Zemli, (Russian), No. 4, April pp. 69-75.Russia, YakutiaGeophysics, paleomagnetics, Deposit -Udachnaya
DS1994-1670
1994
Spetsius, Z.V.Spetsius, Z.V., Bezborodov, S.M.Mineralogy of new occurrences of diamond bearing eclogites from the Udachnaya kimberlite pipe.Doklady Academy of Sciences USSR, Vol. 327, Oct. pp. 160-164.Russia, YakutiaEclogites, diamonds, Deposit -Udachnaya
DS1994-1671
1994
Spetsius, Z.V.Spetsius, Z.V., Bulanova, G.P., Griffin, W.L.Eclogite containing diamond with a garnet inclusion from the Mir pipeDoklady Academy of Sciences Acad. Science USSR, Vol. 323, No. 2, June pp. 115-119.Russia, YakutiaEcologite, diamond inclusions, Deposit -Mir
DS1994-1672
1994
Spetsius, Z.V.Spetsius, Z.V., Ustinov, V.I., Grinenko, V.A.Variation of oxygen isotope composition during alteration of eclogite To the amorphous state.Doklady Academy of Sciences Acad. Science USSR, Vol. 323, No. 2, June pp. 151-155.RussiaEclogite, Geochronology
DS1995-1811
1995
Spetsius, Z.V.Spetsius, Z.V.Diamondiferous eclogites from Yakutia: evidence for a late stage and multistage formation of diamonds.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 572-574.Russia, YakutiaEclogites, Diamond genesis, age
DS1995-1812
1995
Spetsius, Z.V.Spetsius, Z.V.Occurrence of diamond in the mantle; a case study from the SiberianPlatformJournal of Geochemical Exploration, Vol. 52, pp. 25-40.Russia, SiberiaMantle, Diamond genesis
DS1995-1813
1995
Spetsius, Z.V.Spetsius, Z.V., Griffin, W.L.Trace elements in silicate and ore minerals of eclogite xenoliths From kimberlite pipe Udachnaya, Yakutia.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 575-577.Russia, YakutiaGeochemistry, xenoliths, Deposit -Udachnaya
DS1996-1357
1996
Spetsius, Z.V.Spetsius, Z.V.Mineralogic- petrographic mapping of kimberlite ores and distribution of diamond kimberlite pipes of YakutiaInternational Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 398.Russia, YakutiaPetrography, Diamond mineralogy
DS1998-1389
1998
Spetsius, Z.V.Spetsius, Z.V.Two generations of diamonds in the eclogite xenoliths7th International Kimberlite Conference Abstract, pp. 844-6.Russia, YakutiaEclogites, Deposit - Udachnaya, Mir, Sytykanskaya
DS1998-1390
1998
Spetsius, Z.V.Spetsius, Z.V., Bezborodov, S.M.Compositional variations and floatability of kimberlite ores of Russia7th International Kimberlite Conference Abstract, pp. 847-9.Russia, YakutiaMineral processing - chemical analyses, Zonality
DS1998-1391
1998
Spetsius, Z.V.Spetsius, Z.V., Griffin, B.Secondary phases associated with diamonds in eclogites from Udachnaya pipe:implications for diamond genesis.7th International Kimberlite Conference Abstract, pp. 850-2.Russia, SiberiaXenoliths, Deposit - Udachnaya
DS1998-1392
1998
Spetsius, Z.V.Spetsius, Z.V., Griffin, W.L.Trace element composition of garnet kelphites in xenoliths from Udachnayaas evidence of their origin.7th International Kimberlite Conference Abstract, pp. 853-5.Russia, SiberiaXenoliths, kelphitic rims, Deposit - Udachnaya
DS1998-1393
1998
Spetsius, Z.V.Spetsius, Z.V., Taylor, W.R., Griffin, B.Major and trace element partioning between mineral phases in diamondiferous and non-Diamondiferous eclog..7th International Kimberlite Conference Abstract, pp. 856-8.Russia, SiberiaEclogites, Deposit - Udachnaya
DS1999-0701
1999
Spetsius, Z.V.Spetsius, Z.V.Two generations of diamonds in eclogite xenoliths from Yakutia7th International Kimberlite Conference Nixon, Vol. 2, pp. 823-28.Russia, Siberia, YakutiaEclogite, petrography, morphology, Deposit - Udachnaya, Mir, Sytykanskaya
DS2002-1533
2002
Spetsius, Z.V.Spetsius, Z.V., Taylor, L.A.Partial melting in mantle eclogite xenoliths: connections with diamond paragenesisInternational Geology Review, Vol. 44, No. 11, Nov. pp. 973-87.GlobalDiamond genesis
DS2003-1318
2003
Spetsius, Z.V.Spetsius, Z.V.Highly aluminous xenoliths from kimberlites of Yakutia: mantle petrology implication8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, POSTER abstractRussia, Siberia, YakutiaDeposit - Udachnaya
DS2003-1319
2003
Spetsius, Z.V.Spetsius, Z.V., Mityukhin, S.I., Ivanov, A.S.First discovery of Diamondiferous xenolith in kimberlite from the Botuoba pipe, NakynDoklady Earth Sciences, Vol. 391, 5, pp. 703-6.Russia, YakutiaDiamond genesis, deposit
DS2003-1320
2003
Spetsius, Z.V.Spetsius, Z.V., Taylor, L.A.Diamonds of Yakutia: photographic evidence for their originBellwether Publishing Ltd., [email protected], http:web.utk.edu/~pgi/research/diamond.html due Sept.Russia, YakutiaBook - announcement to be published Sept. 2003
DS2003-1321
2003
Spetsius, Z.V.Spetsius, Z.V., Taylor, L.A.Metasomatic diamonds in eclogite xenoliths: petrologic and photographic evidence8ikc, Www.venuewest.com/8ikc/program.htm, Session 3, POSTER abstractRussia, YakutiaDiamonds - inclusions, Deposit - Udachnaya, Sytykanskaya
DS200412-1885
2003
Spetsius, Z.V.Spetsius, Z.V.Highly aluminous xenoliths from kimberlites of Yakutia: mantle petrology implication.8 IKC Program, Session 6, POSTER abstractRussia, Siberia, YakutiaMantle petrology Deposit - Udachnaya
DS200412-1886
2004
Spetsius, Z.V.Spetsius, Z.V.Petrology of highly aluminous xenoliths from kimberlites of Yakutia.Lithos, Vol. 77, 1-4, Sept. pp. 525-538.Russia, YakutiaEclogite, kyanite, coesite, lithosphere, Udachnaya, Zag
DS200412-1887
2003
Spetsius, Z.V.Spetsius, Z.V., Mityukhin, S.I., Ivanov, A.S.First discovery of Diamondiferous xenolith in kimberlite from the Botuoba pipe, Nakyn Field, Yakutia.Doklady Earth Sciences, Vol. 391, 5, pp. 703-6.Russia, YakutiaDiamond genesis , deposit
DS200412-1888
2003
Spetsius, Z.V.Spetsius, Z.V., Taylor, L.A.Diamonds of Yakutia: photographic evidence for their origin.Bellwether Publishing Ltd., due Sept.Russia, YakutiaBook - announcement to be published Sept. 2003
DS200512-0911
2002
Spetsius, Z.V.Rosen, O.M., Serenko, V.P., Spetsius, Z.V., Manakov, A.V., Zinchuk, N.N.Yakutian kimberlite province: position in the structure of the Siberian Craton and composition of the upper and lower crust.Russian Geology and Geophysics, Vol. 45, 1, pp. 1-24.Russia, SiberiaTectonics
DS200512-1030
2004
Spetsius, Z.V.Spetsius, Z.V.Metasomatism and partial melting in xenoliths from the kimberlites of Yakutia: implication to the origin of diamonds.Deep seated magmatism, its sources and their relation to plume processes., pp. 128-159.RussiaGenesis
DS200512-1031
2002
Spetsius, Z.V.Spetsius, Z.V.Evidence for the resemblance of the subcontinental lithospheric mantle in the areas of kimberlite lamproite magmatism: constraints on the evolution of the Siberian Craton.Deep Seated Magmatism, magmatism sources and the problem of plumes., pp. 132-147.Russia, SiberiaMagmatism - Siberian Craton
DS200512-1032
2005
Spetsius, Z.V.Spetsius, Z.V., Mityukhin, S.I., Ivanov, A.S., Banzeruk, S.V.Paragenesis of inclusions in diamonds from the Botuobinskaya kimberlite pipe.Doklady Earth Sciences, Vol. 403, 5, pp. 808-811.RussiaDiamond genesis
DS200512-1033
2003
Spetsius, Z.V.Spetsius, Z.V., Taylor, L.A.Kimberlite xenoliths as evidence for subducted oceanic crust in the formation of the Siberian Carton.Plumes and problems of deep sources of alkaline magmatism, pp. 5-19.RussiaSubduction
DS200612-0937
2005
Spetsius, Z.V.Mityukhin, S.I., Spetsius, Z.V.Paragenesis of inclusions in diamonds from the Botuobinskaya pipe. Nakyn field, Yakutia.Russian Geology and Geophysics, Vol. 46, 12, pp. 1225-1236.Russia, YakutiaDiamond inclusions - Botuobinskaya
DS200612-1343
2006
Spetsius, Z.V.Spetsius, Z.V., Ivanov, A.S., Mityukhin, S.I.Diamondiferous xenoliths and megacrysts from the Nyurbinskaya kimberlite pipe, Nakynsky field, Yakutia).Doklady Earth Sciences, Vol. 409, 5, pp. 779-783.RussiaDeposit - Nyurbinskaya
DS200612-1344
2005
Spetsius, Z.V.Spetsius, Z.V., Spetsius, V.Z.Exsolution textures and minerals In homogeneity in xenoliths from Yakutian kimberlites: evidence for the mantle evolution.Problems of Sources of deep magmatism and plumes., pp. 148-169.Russia, YakutiaMineral chemistry
DS200612-1345
2006
Spetsius, Z.V.Spetsius, Z.V., Taylor, L.A., Valley, J.V., Ivanov, A.S., Banzeruk, V.L., Spicuzza, M.Garnets of anomalous oxygen isotope composition in Diamondiferous xenoliths Nyurbinskaya pipe, Yakutia.Vladykin: VI International Workshop, held Mirny, Deep seated magmatism, its sources and plumes, pp. 59-78.Russia, YakutiaDeposit - Nyurbaninskaya, mineralogy
DS200612-1418
2005
Spetsius, Z.V.Taylor, L.A., Spetsius, Z.V., Wiesli, R., Spicuzza, M., Valley, J.W.Diamondiferous peridotites from oceanic protoliths: crustal signatures from Yakutian.Russian Geology and Geophysics, Vol. 46, 12, pp. 1176-1184.RussiaPeridotite - diamond morphology
DS200712-1026
2007
Spetsius, Z.V.Spetsius, Z.V., Griffin, W.L., O'Reilly, S.Y., Banzeruck, V.I.Trace elements in garnets of Diamondiferous xenoliths from the Nurbinskaya pipe, Yakutia.Plates, Plumes, and Paradigms, 1p. abstract p. A961.RussiaNurbinskaya
DS200812-1102
2007
Spetsius, Z.V.Spetsius, Z.V.The nature of indicator minerals in kimberlites: a case from the mantle xenoliths studying.Vladykin Volume 2007, pp. 90-108.MantleXenoliths - mineral chemistry
DS200812-1103
2008
Spetsius, Z.V.Spetsius, Z.V., Taylor, L.A., Valley, J.W., DeAngelsi, M., Spicuzza, M., Ivanov, A.S., Banzeruk, V.I.Diamondiferous xenoliths from crustal subduction: garnet oxygen isotopes from the Nyurbinskaya pipe, Yakutia.European Journal of Mineralogy, Vol. 20, no. 3, pp. 375-385.Russia, YakutiaDeposit - Nyurbinskaya
DS200812-1104
2008
Spetsius, Z.V.Spetsius, Z.V., Zezekalo, M., Yu, Tarskhix, O.Y.Pecularities of mineralogy and petrography of the upper Muna field kimberlites: application to the lithospheric mantle composition.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., 2008 pp. 137-146.Russia, SiberiaDeposit - Muna field
DS200912-0722
2009
Spetsius, Z.V.Spetsius, Z.V., Wiggers De Vries, D.F., Davies, G.R.Combined C isotope and geochemical evidence for a recycled origin for Diamondiferous eclogite xenoliths from kimberlites of Yakutia.Lithos, In press availableRussia, YakutiaGeochronology, geochemistry
DS201012-0405
2010
Spetsius, Z.V.Kornilova, V.P., Spetsius, Z.V., Lelukh, M.I., Gerasimchuk, A.V.Pecularities of garnets from kimberlites of Nakynsky field, Yakutia.International Mineralogical Association meeting August Budapest, abstract p. 571.Russia, YakutiaChemistry - Mayaskaya, Nuyrbinskaya pipes
DS201012-0626
2010
Spetsius, Z.V.Riches, A.J.V., Liu, Y., Day, J.M.D., Spetsius, Z.V., Taylor, L.A.Evolution of the Siberian platform: constraints from Diamondiferous xenoliths of Nyurbinskaya.Goldschmidt 2010 abstracts, abstractRussiaDeposit - Nyurbinskaya
DS201012-0627
2010
Spetsius, Z.V.Riches, A.J.V., Liu, Y., Day, J.M.D., Spetsius, Z.V., Taylor, L.A.Subducted oceanic crust as diamond hosts revealed by garnets of mantle xenoliths from Nyyurbinskaya, Siberia.Lithos, In press available, 54p.Russia, YakutiaPetrology
DS201112-0861
2010
Spetsius, Z.V.Riches, A.J.V., Liu, Y., Day, J.M.D., Spetsius, Z.V., Taylor, L.A.Subducted oceanic crust as diamond hosts revealed by garnets of mantle xenoliths from Nyurbinskaya, Siberia.Lithos, Vol. 120, pp. 368-378.Russia, SiberiaEclogite, genesis
DS201112-0991
2011
Spetsius, Z.V.Spetsius, Z.V., Belousova, E.A., Griffin, W.L., O'Reilly, S.Y., Ivanov, A.S.Zircon from kimberlites of the Nyurbinskaya pipe as indicator of kimberlite emplacement and lithosphere evolution.Goldschmidt Conference 2011, abstract p.1922.RussiaNakynsky
DS201212-0438
2012
Spetsius, Z.V.Malkovets, V.G., Griffin, W.L., Pearson, N.J., Rezvukhin, D.I., Oreilly, S.Y., Pokhilenko, N.P., Garanin, V.K., Spetsius, Z.V., Litasov, K.D.Late metasomatic addition of garnet to the SCLM: Os-itope evidence.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractMantleMetasomatism
DS201212-0695
2012
Spetsius, Z.V.Spetsius, Z.V., Griffin, W.L., Ivanov, A.S.Inclusions and internal structure of diamonds: a key to their genetic growth.emc2012 @ uni-frankfurt.de, 1p. AbstractRussiaDeposit - Udachnaya, Nurbinskaya
DS201212-0696
2012
Spetsius, Z.V.Spetsius, Z.V., Kamenetsky, V.S.Mapping of mineral phases around diamonds in eclogite xenoliths from the Udachnaya kimberlite pipe ( Yakutia): remarks to their metasomatic genesis.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, YakutiaDeposit - Udachnaya
DS201212-0697
2012
Spetsius, Z.V.Spetsius, Z.V., Kovalchuck, O.E., Bogush, I.N.Properties of diamonds in xenoliths from kimberlites of Yakutia: implication to their origin and exploration.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, YakutiaXenoliths
DS201312-0874
2012
Spetsius, Z.V.Spetsius, Z.V., Kornilova, V.P., Tarskikh, O.V.Pecularities of petrography and mineralogy kimberlites from deep levels of the Internationalaya pipe.Vladykin, N.V. ed. Deep seated magmatism, its sources and plumes, Russian Academy of Sciences, pp. 204-225.RussiaDeposit - Internationalaya
DS201412-0676
2014
Spetsius, Z.V.Pernet-Fisher, J.F., Howarth, G.H., Liu, Y., Barry, P.H., Carmody, L., Valley, J.W., Bodnar, R.J., Spetsius, Z.V., Taylor, L.A.Komsomolskaya Diamondiferous eclogites: evidence for oceanic crustal protoliths.Contributions to Mineralogy and Petrology, Vol. 167, pp. 1-17.Russia, SiberiaDeposit - Komsomolskaya
DS201412-0877
2014
Spetsius, Z.V.Spetsius, Z.V., Polyanichko, V.V., Xarlamova, E.I.,Tarskix, O.V., Ivanov, A.S.Geology, petrography and mineralogy of the Zarya pipe kimberlites.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., pp. 160-177.RussiaDeposit - Zarya
DS201502-0107
2015
Spetsius, Z.V.Spetsius, Z.V., Bogush, I.N., Kovalchuk, O.E.FTIR mapping of diamond plates of eclogitic and peridotitic xenoliths from Nyurbinskaya pipe, Yakutia: genetic implications.Russian Geology and Geophysics, Vol. 56, 1, pp. 344-353.RussiaDeposit - Nyurbinskaya
DS201510-1807
2014
Spetsius, Z.V.Spetsius, Z.V., Polyanichko, V.V., Xarlamova, E.I., Tarskix, O.V., Ivanov, A.S.Geology, petrography and mineralogy of the Zarya pipe kimberlites.Deep-seated magmatism, its sources and plumes, Proceedings of XIII International Workshop held 2014., Vol. 2014, pp. 160-177.RussiaDeposit - Zarya
DS201612-2275
2016
Spetsius, Z.V.Ashchepkov, I.V., Ntaflos, T., Logvinova, A.M., Spetsius, Z.V., Downe, H., Vladykin, N.V.Monomineral universal clinopyroxene and garnet barometers for peridotitic, eclogitic and basaltic systems.Geoscience Frontiers, in press availableTechnologyMineralogy

Abstract: New versions of the universal Jd-Di exchange clinopyroxene barometer for peridotites, pyroxenites and eclogites, and also garnet barometer for eclogites and peridotites were developed. They were checked using large experimental data sets for eclogitic (?530) and peridotitic systems (>650). The precision of the universal Cpx barometer for peridotites based on Jd-Di exchange is close to Cr-Tschermakite method produced by Nimis and Taylor (2000). Cpx barometer was transformed by the substitution of major multiplier for KD by the equations dependent from Al-Na-Fe. Obtained equation in combination with the thermometer of Nimis and Taylor (2000) allow to reconstruct position of the magma feeder systems of the alkali basaltic magma within the mantle diapirs in modern platforms like in Vitim plateau and other Southern Siberia localities and several localities worldwide showing good agreement of pressure ranges for black and green suites. These equations allow construct PTX diagrams for the kimberlite localities in Siberia and worldwide calculating simultaneously the PT parameters for different groups of mantle rocks. They give very good results for the concentrates from kimberlite lamproites and placers with mantle minerals. They are useful for PT estimates for diamond inclusions. The positions of eclogite groups in mantle sections are similar to those determined with new Gar-Cpx barometer produced by C. Beyer et al. (2015). The Fe rich eclogites commonly trace the boundary between the lower upper parts of subcontinental lithospheric mantle (SCLM) at 3-4 GPa marking pyroxenite eclogites layer. Ca-rich eclogites and especially grospydites in SCLM beneath Precambrian kimberlites occurs near pyroxenite layer but in younger mantle sections they became common in the lower parts. The diamondiferous Mg Cr-less group eclogites referring to the ancient island arc complexes are also common in the middle part of mantle sections and near 5-6 GPa. Commonly eclogites in lower apart of mantle sections are remelted and trace the high temperature convective branch. The Mg- and Fe-rich pyroxenites also show the extending in pressure trends which suggest the anatexic melting under the influence of volatiles or under the interaction with plums.
DS201612-2279
2016
Spetsius, Z.V.Bardukhinov, L.D., Spetsius, Z.V., Monkhorov, R.V.Coesite inclusions in diamonds of Yakutia. Doklady Earth Sciences, Vol. 470, 2, pp. 1042-1045.Russia, YakutiaDeposit - Zapolyarnaya, Maiskaya, Komsomolskaya-Magnitnaya

Abstract: The results of the study of diamonds with inclusions of high-pressure modification of SiO2 (coesite) by Raman spectroscopy are reported. It is established that the octahedral crystal from the Zapolyarnaya pipe is characterized by the highest residual pressure (2.7 ± 0.07 GPa). An intermediate value of this parameter (2.1 ± 0.07 GPa) was obtained for a crystal of transitional habit from the Maiskaya pipe. The minimal Raman shift was registered for coesite in diamond from the Komsomol’skaya-Magnitnaya pipe and provided a calculated residual pressure of 1.8 ± 0.03 GPa. The residual pressures for crystals from the placer deposits of the Kuoika and Bol’shaya Kuonamka rivers are 2.7 ± 0.07 and 3.1 ± 0.1 GPa, respectively. Octahedral crystals were formed in the mantle at a higher pressure than rhombododecahedral diamonds.
DS201804-0742
2018
Spetsius, Z.V.Spetsius, Z.V., Bogush, I.N., Ivanov, A.S.Xenolith of eclogites with diamonds from the Yubileinaya kimberlite pipe.Doklady Earth Sciences, Vol. 478, 1, pp. 88-91.Russia, Yakutiadeposit - Yubilienaya

Abstract: The first results of study of minerals and diamonds of diamond-bearing eclogites from kimberlites of the Yubileinaya pipe with a variable percent amount of clinopyroxene and garnet are presented. Samples with a garnet content from 30 to 90% of the xenolith volume are dominant among the round to oval xenoliths with diamonds. Five eclogite samples contain grains of accessory rutile, as well as corundum and kyanite. Some samples host two or more diamond crystals.
DS201809-2095
2018
Spetsius, Z.V.Spetsius, Z.V., Bogush, I.N.Pecularities of diamonds in eclogitic xenoliths from the Komsomolskaya pipe, Yakutia.Doklady Earth Sciences, Vol. 480, 1, pp. 666-670.Russiadeposit - Komsomolskaya

Abstract: The first studies of diamonds in eclogitic xenoliths from the Komsomolskaya kimberlite pipe are described. Among round and oval-shaped xenoliths with diamond ingrowths, samples with a garnet content of 40-90% of the xenolith volume dominate. Two eclogite samples contain grains of accessory rutile; a kyanite sample is also revealed. Certain samples contain two or more crystals of diamonds. Diamonds with an octahedral habit and crystals with transitional habits, which belong to an octahedral-rhombic dodecahedral row, dominate in eclogites; there are many variety VIII aggregates. A high concentration of structural nitrogen, commonly in the A form, was registered in most of the crystals. Diamonds with a small content of nitrogen impurities, 40-67% in the B1 form, are present in a number of xenoliths. The calculated temperatures of the formation of eclogitic xenoliths is 1100-1300°C. Diversity in the impurity compositions of diamonds in the same xenolith shows that these diamonds were formed at various times and in different settings. The diamond position in xenoliths, the various level of nitrogen aggregation in the diamonds, and a number of other factors point to the later formation of the diamonds, as compared to minerals of eclogites, from fluid or fluid-melts in the process of metasomatosis.
DS201902-0255
2019
Spetsius, Z.V.Abersteiner, A., Kamenetsky, V.S., Goemann, K., Golovin, A.V., Sharygin, I.S., Giuliani, A., Rodemann, T., Spetsius, Z.V., Kamenetsky, M.Djerfisherite in kimberlites and their xenoliths: implications for kimberlite melt evolution.Contributions to Mineralogy and Petrology, Vol. 174, 8 22p. Africa, South Africa, Russia, Canada, Northwest Territoriesdeposit - Bultfontein, Roberts Victor, Udachnaya-East, Obnazhennaya, Vtorogodnitsa, Koala, Leslie

Abstract: Djerfisherite (K6(Fe,Ni,Cu)25S26Cl) occurs as an accessory phase in the groundmass of many kimberlites, kimberlite-hosted mantle xenoliths, and as a daughter inclusion phase in diamonds and kimberlitic minerals. Djerfisherite typically occurs as replacement of pre-existing Fe-Ni-Cu sulphides (i.e. pyrrhotite, pentlandite and chalcopyrite), but can also occur as individual grains, or as poikilitic phase in the groundmass of kimberlites. In this study, we present new constraints on the origin and genesis of djerfisherite in kimberlites and their entrained xenoliths. Djerfisherite has extremely heterogeneous compositions in terms of Fe, Ni and Cu ratios. However, there appears to be no distinct compositional range of djerfisherite indicative of a particular setting (i.e. kimberlites, xenoliths or diamonds), rather this compositional diversity reflects the composition of the host kimberlite melt and/or interacting metasomatic medium. In addition, djerfisherite may contain K and Cl contents less than the ideal formula unit. Raman spectroscopy and electron backscatter diffraction (EBSD) revealed that these K-Cl poor sulphides still maintain the same djerfisherite crystal structure. Two potential mechanisms for djerfisherite formation are considered: (1) replacement of pre-existing Fe-Ni-Cu sulphides by djerfisherite, which is attributed to precursor sulphides reacting with metasomatic K-Cl bearing melts/fluids in the mantle or the transporting kimberlite melt; (2) direct crystallisation of djerfisherite from the kimberlite melt in groundmass or due to kimberlite melt infiltration into xenoliths. The occurrence of djerfisherite in kimberlites and its mantle cargo from localities worldwide provides strong evidence that the metasomatising/infiltrating kimberlite melt/fluid was enriched in K and Cl. We suggest that kimberlites originated from melts that were more enriched in alkalis and halogens relative to their whole-rock compositions.
DS202201-0001
2021
Spetsius, Z.V.Ashchepkov, I.V., Logvinova, A.M., Spetsius, Z.V.Thermobarometry of inclusions: implications to the structure of lithospheric mantle and evolution in time and diamond formation.Acta Geologica Sinica, Vol. 95, 1, pp. 18-21.Mantlegeobarometry
DS1997-1168
1997
Spetsius etTrautman, R.L., Griffin, B.J., Taylor, W.R., Spetsius etA comparison of the microdiamonds from kimberlite and lamproite of Yakutia and Australia.Russian Geology and Geophysics, Vol. 38, No. 2, pp. 341-355.Australia, Russia, YakutiaMicrodiamonds, Morphology, physical properties
DS1991-0107
1991
Spetsuius, Z.V.Beskrovanov, V.V., Spetsuius, Z.V., Malogolovets, V.G., KhrenovMorphology and physical properties of diamonds from mantlexenoliths.(Russian)Mineral. Zhurn., (Russian), Vol. 13, No. 5, October pp. 31-42RussiaDiamond morphology, Xenoliths
DS1995-1391
1995
SpettelO'Neill, H. St. C., Dingwell, D.B., Borisov, A., SpettelExperimental petrochemistry of some highly siderophile elements at hightemperatures, core formation mantle.Chemical Geology, Vol. 120, No. 3-4, March 1, pp. 255-273.MantleGeochemistry
DS1983-0328
1983
Spettel, B.Jagoutz, E., Spettel, B., Waenke, H., Dawson, B.Identification of Early Differentiation Processes on the Earth.Meteoritics, Vol. 18, No. 4, PP. 319-320. (abstract.).GlobalGeochemistry, Kimberlite, Ultramafics
DS1984-0375
1984
Spettel, B.Jagoutz, E., Dawson, J.B., Hoernes, S., Spettel, B., Waenke, H.Anorthositic Oceanic Crust in the Archean EarthLunar and Planetary Science Conference 15th. Abstract Volume, Vol. 15, pp. 395-396GlobalAnorthosite
DS1989-0714
1989
Spettel, B.Jochum, K.P., McDonough, W.F., Palme, H., Spettel, B.Compositional constraints on the continental lithospheric mantle from trace elements in spinel peridotite xenolithsNature, Vol. 340, No. 6234, August 17, pp. 548-550GlobalMantle, Xenoliths
DS1989-1095
1989
Spettel, B.Navon, O., Spettel, B., Hutcheon, I.H., Rossman, G.R, WasserburgMicro-inclusions in diamonds from Zaire and BotswanaDiamond Workshop, International Geological Congress, July 15-16th. editors, pp. 69-72. AbstractGlobalDiamond Inclusions, Diamond morphology
DS1994-0886
1994
Spettel, B.Keller, J., Spettel, B.The trace element composition and petrogenesis of natrocarbonatitesCarbonatite volcanism, Ed. Bell, K., Keller, J., pp. 70-86.TanzaniaPetrology - Carbonatite volcanism., Deposit -Oldoinyo Lengai
DS1996-1379
1996
Spettel, B.Stolz, A.J., Jochun, K.P., Spettel, B., Hoffmann, A.W.Fluid and melt related enrichment in the subarc mantle: evidence from Niobium-Tantalum variations in island arc basaltsGeology, Vol. 24, No. 7, July, pp. 587-590MantleSubarc subduction, Basalts
DS2003-1228
2003
Spettel, B.Schmidt, G., Witt Eiscksen, G., Palme, H., Seek, H., Spettel, B., Kratz, K.L.Highly siderophile elements ( PGE Re and Au) in mantle xenoliths from the west EiffelChemical Geology, Vol. 196, No. 1-4, pp. 77-105.GermanyXenoliths
DS200412-1757
2003
Spettel, B.Schmidt, G., Witt Eiscksen, G., Palme, H., Seek, H., Spettel, B., Kratz, K.L.Highly siderophile elements ( PGE Re and Au) in mantle xenoliths from the west Eiffel volcanic field, Germany.Chemical Geology, Vol. 196, no. 1-4, pp. 77-105.Europe, GermanyXenoliths
DS200912-0840
2009
Spetzler, H.A.Yoneda, A., Chen, G., Spetzler, H.A., Getting, I.G.The effect of composition, temperature and pressure on the elasticity of olivine and garnet: implications for interpreting seismic velocity variations in mantle.mantleplumes.org, 8p.MantleGeophysics - seismics
DS200612-1346
2005
Speziale, S.Speziale, S., Jiang, F., Duffy, T.S.Compositional dependence of the elastic wave velocities of mantle minerals: implications for seismic properties of mantle rocks.American Geophysical Union, Geophysical Monograph, ed. Van der Hilst, Earth's Deep mantle, structure ...., No. 160, pp. 301-320.MantleGeophysics - seismics
DS200612-1347
2005
Speziale, S.Speziale, S., Milner, A., Lee, V.E., Clark, S.M.Iron spin transition in Earth's mantle.Proceedings of National Academy of Science USA, Vol. 102, no. 50, Dec. 13, p. 17918.MantleGeochemistry
DS200612-1521
2006
Speziale, S.Wenk, H-R., Speziale, S., McNamara, A.K., Garnero, E.J.Modeling lower mantle anistropy development in a subducting slab.Earth and Planetary Science Letters, Vol. 245, 1-2, pp. 302-314.MantleSubduction
DS201610-1893
2016
Speziale, S.Pamato, M.G., Kurnosov, A., Boffa Ballaran, T., Frost, D.J., Ziberna, L., Gianni, M., Speziale, S., Tkachev, S.N., Zhuravlev, K.K., Prakapenka, V.B.Single crystal elasticity of majoritic garnets: stagnant slabs and thermal anomalies at the base of the transition zone.Earth and Planetary Science Letters, Vol. 451, pp. 114-124.MantleSubduction

Abstract: The elastic properties of two single crystals of majoritic garnet (Mg3.24Al1.53Si3.23O12 and Mg3.01Fe0.17Al1.68Si3.15O12), have been measured using simultaneously single-crystal X-ray diffraction and Brillouin spectroscopy in an externally heated diamond anvil cell with Ne as pressure transmitting medium at conditions up to ?30 GPa and ?600 K. This combination of techniques makes it possible to use the bulk modulus and unit-cell volume at each condition to calculate the absolute pressure, independently of secondary pressure calibrants. Substitution of the majorite component into pyrope garnet lowers both the bulk (KsKs) and shear modulus (G ). The substitution of Fe was found to cause a small but resolvable increase in KsKs that was accompanied by a decrease in ?Ks/?P?Ks/?P, the first pressure derivative of the bulk modulus. Fe substitution had no influence on either the shear modulus or its pressure derivative. The obtained elasticity data were used to derive a thermo-elastic model to describe VsVs and VpVp of complex garnet solid solutions. Using further elasticity data from the literature and thermodynamic models for mantle phase relations, velocities for mafic, harzburgitic and lherzolitic bulk compositions at the base of Earth's transition zone were calculated. The results show that VsVs predicted by seismic reference models are faster than those calculated for all three types of lithologies along a typical mantle adiabat within the bottom 150 km of the transition zone. The anomalously fast seismic shear velocities might be explained if laterally extensive sections of subducted harzburgite-rich slabs pile up at the base of the transition zone and lower average mantle temperatures within this depth range.
DS201809-2003
2018
Speziale, S.Buchen, J., Marquardt, H., Speziale, S., Kawazoe, T., Ballaran, T.B., Kumosov, A.High pressure single crystal elasticity of wadlsleyite and the seismic signature of water on the shallow transition zone.Earth and Planetary Science Letters, Vol. 498, pp. 77-87.Mantlegeophysics - seismic

Abstract: Earth's transition zone at depths between 410 km and 660 km plays a key role in Earth's deep water cycle since large amounts of hydrogen can be stored in the nominally anhydrous minerals wadsleyite and ringwoodite, . Previous mineral physics experiments on iron-free wadsleyite proposed low seismic velocities as an indicative feature for hydration in the transition zone. Here we report simultaneous sound wave velocity and density measurements on iron-bearing wadsleyite single crystals with 0.24 wt-% . By comparison with earlier studies, we show that pressure suppresses the velocity reduction caused by higher degrees of hydration in iron-bearing wadsleyite, ultimately leading to a velocity cross-over for both P-waves and S-waves. Modeling based on our experimental results shows that wave speed variations within the transition zone as well as velocity jumps at the 410-km seismic discontinuity, both of which have been used in previous work to detect mantle hydration, are poor water sensors. Instead, the impedance contrast across the 410-km seismic discontinuity that is reduced in the presence of water can serve as a more robust indicator for hydrated parts of the transition zone.
DS202204-0523
2022
Speziale, S.Immoor, J., Miyagi, L., Liermann, H-P., Speziale, S., Schulkze, K., Buchen, J., Kurnosov, A., Marquardt, H.Weak cubic CaSi0s perovskite in the Earth's mantle.Nature , Vol. 603, pp. 276-279. 10.1038/s41586-021-04378-2Mantleperovskite

Abstract: Cubic CaSiO3 perovskite is a major phase in subducted oceanic crust, where it forms at a depth of about 550 kilometres from majoritic garnet1,2,28. However, its rheological properties at temperatures and pressures typical of the lower mantle are poorly known. Here we measured the plastic strength of cubic CaSiO3 perovskite at pressure and temperature conditions typical for a subducting slab up to a depth of about 1,200 kilometres. In contrast to tetragonal CaSiO3, previously investigated at room temperature3,4, we find that cubic CaSiO3 perovskite is a comparably weak phase at the temperatures of the lower mantle. We find that its strength and viscosity are substantially lower than that of bridgmanite and ferropericlase, possibly making cubic CaSiO3 perovskite the weakest lower-mantle phase. Our findings suggest that cubic CaSiO3 perovskite governs the dynamics of subducting slabs. Weak CaSiO3 perovskite further provides a mechanism to separate subducted oceanic crust from the underlying mantle. Depending on the depth of the separation, basaltic crust could accumulate at the boundary between the upper and lower mantle, where cubic CaSiO3 perovskite may contribute to the seismically observed regions of low shear-wave velocities in the uppermost lower mantle5,6, or sink to the core-mantle boundary and explain the seismic anomalies associated with large low-shear-velocity provinces beneath Africa and the Pacific7-9.
DS200412-1889
2004
Spicak, A.Spicak, A., Cadek, O., Engdahl, E.R.Structure and tectonics of convergent plate margins.Physics of the Earth and Planetary Interiors, Vol. 141, 4, pp. 241-MantleTectonics
DS200712-0795
2007
SpicuzzaPage, F.Z., Fu, B., Kita, N.T., Fournelle, Spicuzza, Schulze, Viljoen, Basei, ValleyZircons from kimberlite: new insights into oxygen isotopes, trace elements, and Ti in zircon thermometry.Geochimica et Cosmochimica Acta, Vol. 71, 15, pp. 3887-3903.TechnologyZircon thermometry
DS200912-0447
2009
SpicuzzaLiu, Y., Taylor, L.A., Sarbadhikari, Valley, Ushikubo, Spicuzza, Kita, Ketchum, Carlson, Shatsky, SobolevMetasomatic origin of diamonds in the world's largest Diamondiferous eclogite.Lithos, In press - available 41p.RussiaDeposit - Udachnaya
DS1991-1525
1991
Spicuzza, M.Schulze, D.J., Valley, J.W., Viljoen, K.S., Spicuzza, M.Carbon isotope composition of graphite in mantle eclogitesProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 353-355South Africa, BotswanaXenoliths, Bellsbank, Jagersfontein, Orapa, Letlhakane, eclogites
DS1998-1301
1998
Spicuzza, M.Schulze, D.J., Valley, J.W., Bell, D.R., Spicuzza, M.Significance of oxygen isotope variations in the chromium-poor megacryst suite7th. Kimberlite Conference abstract, pp. 769-71.South Africa, North AmericaKimberlite - Group I, II, Subduction
DS2001-1039
2001
Spicuzza, M.Schulze, D.K., Valley, J.R., Bell, D.R., Spicuzza, M.Oxygen isotope variations in Cromium poor megacrysts from kimberliteGeochimica et Cosmochimica Acta., Vol. 65, No. 23, pp. 4375-84.Ontario, South AfricaGeochronology, Chromium
DS200612-1345
2006
Spicuzza, M.Spetsius, Z.V., Taylor, L.A., Valley, J.V., Ivanov, A.S., Banzeruk, V.L., Spicuzza, M.Garnets of anomalous oxygen isotope composition in Diamondiferous xenoliths Nyurbinskaya pipe, Yakutia.Vladykin: VI International Workshop, held Mirny, Deep seated magmatism, its sources and plumes, pp. 59-78.Russia, YakutiaDeposit - Nyurbaninskaya, mineralogy
DS200612-1418
2005
Spicuzza, M.Taylor, L.A., Spetsius, Z.V., Wiesli, R., Spicuzza, M., Valley, J.W.Diamondiferous peridotites from oceanic protoliths: crustal signatures from Yakutian.Russian Geology and Geophysics, Vol. 46, 12, pp. 1176-1184.RussiaPeridotite - diamond morphology
DS200812-0584
2008
Spicuzza, M.Konish, H., Xu, H., Spicuzza, M.,Valley, J.W.Polycrystalline diamond inclusions in Jack Hills zircon: carbonado?Goldschmidt Conference 2008, Abstract p.A489.AustraliaDiamond inclusions
DS200812-1103
2008
Spicuzza, M.Spetsius, Z.V., Taylor, L.A., Valley, J.W., DeAngelsi, M., Spicuzza, M., Ivanov, A.S., Banzeruk, V.I.Diamondiferous xenoliths from crustal subduction: garnet oxygen isotopes from the Nyurbinskaya pipe, Yakutia.European Journal of Mineralogy, Vol. 20, no. 3, pp. 375-385.Russia, YakutiaDeposit - Nyurbinskaya
DS201901-0039
2018
Spicuzza, M.Gu, T., Valley, J., Kitajima, K., Spicuzza, M., Fournelle, J., Stern, R., Ohfuji, H., Wang, W.Evidence of subducted altered oceanic crust into deep mantle from inclusions of type IaB diamonds,Gems & Gemology, Sixth International Gemological Symposium Vol. 54, 3, 1p. Abstract p. 306-7.Mantlediamond inclusions

Abstract: Nitrogen is one of the most common impurities in diamond, and its aggregation styles have been used as criteria for diamond classification. Pure type IaB diamonds (with 100% nitrogen in B aggregation) are rather rare among natural diamonds. The occurrence of the B center is generally associated with high temperature and a long residence time of the host diamond, which would potentially provide information on the earth’s deep interior. Seawater circulation is the unique process that shapes the surface of our planet and potentially has a profound effect on its interior due to slab subduction. In about 50 type IaB diamonds with detectable micro-inclusions submitted to GIA for screening, we found that more than 70% of them contained a typical mineral assemblage from the sublithosphere. Jeffbenite (TAPP), majorite garnet, enstatite, and ferropericlase have been observed, which could be retrograde products of former bridgmanite. CaSiO3-walstromite with larnite and titanite is the dominant phase present in approximately 40% of all diamond samples. Direct evidence from oxygen isotope ratios measured by secondary ion mass spectrometry, or SIMS, (?18OVSMOWin the range +10.7 to +12.5‰) of CaSiO3-walstromite with coexisting larnite and titanite that retrograde from CaSiO3-perovskite suggest that hydrothermally altered oceanic basalt can subduct to depths of >410 km in the transition zone. Incorporation of materials from subducted altered oceanic crust into the deep mantle produced diamond inclusions that have both lower mantle and subduction signatures. Ca(Si,Al)O3-perovskite was observed with a high concentration of rare earth elements (>5 wt.%) that could be enriched under P-Tconditions in the lower mantle. Evidence from ringwoodite with a hydroxide bond, coexisting tuite and apatite, precipitates of an NH3phase, and cohenite with trace amounts of Cl imply that the subducted brines can potentially introduce hydrous fluid to the bottom of the transition zone. In the diamonds with subducted materials, the increasing carbon isotope ratio from the core to the rim region detected by SIMS (?13C from -5.5‰ to -4‰) suggests that an oxidized carbonate-dominated fluid was associated with recycling of the subducted hydrous material. The deep subduction played an important role in balancing redox exchange with the reduced lower mantle indicated by precipitated iron nanoparticles and coexisting hydrocarbons and carbonate phases.
DS1998-0086
1998
Spicuzza, M.J.Barth, M.G., Rudnick, R.L., Spicuzza, M.J., Valley, J.The role of eclogites in the growth of Archean cratons: a case study from west Africa.7th International Kimberlite Conference Abstract, pp. 52-54.GlobalMan Shield, eclogites, Deposit - Koidu
DS1998-1507
1998
Spicuzza, M.J.Valley, J.W., Kinny, P.D., Spicuzza, M.J.Zircon megacrysts from kimberlite: oxygen isotope variability among mantlemelts.Contributions to Mineralogy and Petrology, Vol. 133, No. 1-2, pp. 1-11.MantleGeochronology, Megacryst - mineralogy
DS2000-0874
2000
Spicuzza, M.J.Schulze, D.J., Valley, J.W., Spicuzza, M.J.Coesite eclogites from the Roberts Victor kimberlite, South AfricaLithos, Vol. 54, No. 1-2, Oct. pp. 23-32.South AfricaTectonics - subduction, Deposit - Roberts Victor
DS2002-0112
2002
Spicuzza, M.J.Barth, M.G., Rudnick, R.L., Horn, J., McDononough, W.F., Spicuzza, M.J.Geochemistry of xenolithic eclogites from West Africa: part 2. origins of the high MgO eclogites.Geochimica et Cosmochimica Acta, Vol. 66, 24, pp. 4325-45.West Africa, Liberia, Sierra LeoneEclogites
DS2002-0683
2002
Spicuzza, M.J.Haynes, E.A., Moetcher, D.P., Spicuzza, M.J.Oxygen isotope contamination of carbonates, silicates and oxides in selected carbonatites: constraints on crystallization temperatures of carbonatitic magmas.Unknown, Vol. 193, 1-2, Jan 15, pp. 43-57.GlobalCarbonatite, Geochemistry
DS2003-1238
2003
Spicuzza, M.J.Schulze, D.J., Valley, J.W., Viljoen, K.S., Spicuzza, M.J.Oxygen isotope composition of mantle eclogites8ikc, Www.venuewest.com/8ikc/program.htm, Session 2, POSTER abstractSouth Africa, ColoradoEclogites and Diamonds, Geochronology
DS200512-0950
2005
Spicuzza, M.J.Schulze, D.J., Harte, B., Channer, D.M.DrR., Spicuzza, M.J., Viljoen, K.S.Stable isotope evidence for a subduction origin for mantle eclogites and their diamonds.GAC Annual Meeting Halifax May 15-19, Abstract 1p.United States, ColoradoGeochronology, diamond genesis
DS200612-1460
2005
Spicuzza, M.J.Valley, J.W., Lackey, J.S., Cavosie, A.J., Clechenko, C.C., Spicuzza, M.J., Basei, M.A.S., Bindeman, I.N.4.4 billion years of crustal maturation: oxygen isotope ratios.Contributions to Mineralogy and Petrology, Vol. 150, 8, Dec. pp. 561-580.MantleGeochronology
DS201012-0589
2010
Spicuzza, M.J.Pivin, M., Valley, J.W., Spicuzza, M.J., Demaiffe, D.Oxygen isotopic composition of garnet clinopyroxene and zircon megacrysts from kimberlites in Democratic Republic of Congo: insights into their petrogenesis.International Mineralogical Association meeting August Budapest, abstract p. 560.Africa, Democratic Republic of CongoDeposit - Mbuji-Mayi
DS201112-0982
2011
Spicuzza, M.J.Sobolev, N.V., Schertl, H-P., Valley, J.W., Page, F.Z., Kita, N.T., Spicuzza, M.J., Neuser, R.D., Logvinova, A.M.Oxygen isotope variations of garnets and clinopyroxenes in a layered Diamondiferous calcsilicate rock from Kokchetav Massif, Kazakhstan: a window into geochemicalContributions to Mineralogy and Petrology, Vol. 162, 5, pp.1079-1092.Russia, KazakhstanDeeply subducted UHPM rocks
DS201412-0938
2014
Spicuzza, M.J.Valley, J.W., Cavosie, T., Ushikubo, T., Reinhard, D.A., Lawrence, D.F., Larson, D.J., Clifton, P.H., Kelly, T.F., Wilde, S.A., Moser, D.E., Spicuzza, M.J.Hadean age for a post-magma-ocean zircon confirmed by atom-probe tomography.Nature Geoscience, Vol. 7, pp.219-223.MantleGeochronology
DS201505-0243
2015
Spicuzza, M.J.Katzir, Y., Anenburg, M., Kaminchik, J., Segev, A., Blichert-Toft, J., Spicuzza, M.J., Valley, J.W.Garnet pyroxenites as markers of recurring extension and magmatism at the rifted margins of the Levant basin.Israel Geological Society, Abstracts 1p.Europe, Israel, Mt. CarmelPyroxenite
DS201904-0782
2019
Spiech, L.Spiech, L.Update on project Quiddit .. Notes on Diavik diamond rims.researchgate.net, 2p. PdfCanada, Northwest Territoriesdiamond morphology
DS201502-0108
2015
Spiegel, S.J.Spiegel, S.J.Contested diamond certification: reconfiguring global and national interests in Zimbabwe's Marange fields.Geoforum, Vol. 59, Feb. pp. 258-267.Africa, ZimbabweConflict Diamonds CSR
DS2001-1112
2001
Spiegelman, M.Spiegelman, M., Kelemen, P.B., Aharonov, E.Causes and consequences of flow organization during melt transport: the reaction infiltration instabilityJournal of Geophysical Research, Vol. 106, No.2, Feb.10, pp. 2061-78.MantleCompaction media, Melting
DS2002-0034
2002
Spiegelman, M.Anders, M.H., Gregory-Wodzicki, K.M., Spiegelman, M.A critical evaluation of Late Tertiary accelerated uplift rates for the eastern Cordillera, central AndesJournal of Geology, Vol.110,1,pp. 89-100.BoliviaTectonics
DS200412-0469
2004
Spiegelman, M.Donnelly,K.E., Goldstein, S.L., Langmuir, C.H., Spiegelman, M.Origin of enriched ocean ridge basalts and implications for mantle dynamics.Earth and Planetary Science Letters, Vol. 226, 3-4, Oct. 15, pp. 347-366.MantleE-MORB, geochemistry, isotope, trace, convective mixing
DS200512-0500
2003
Spiegelman, M.Katz, R.F., Spiegelman, M., Langmuir, C.H.A new parameterization of hydrous mantle melting.Geochemistry, Geophysics, Geosystems: G3, Vol. 4, 9, p. 1073 10.1029/2002 GC000433MantleMelting, water
DS200912-0153
2009
Spiegelman, M.Dasgupta, R., Hirschmann, M.M., McDonough, W.F., Spiegelman, M., Withers, A.C.Trace element partitioning between garnet lherzolite and carbonatite at 6.6 and 8.6 GPa with application to the geochemistry of the mantle and mantle derived meltsChemical Geology, Vol. 262, 1-2, May 15, pp. 57-77.MantleMelting
DS201012-0641
2010
Spiegelman, M.Rudge, J.F., Kelemen, P.B., Spiegelman, M.A simple model of reaction induced cracking applied to serpentinization and carbonation of peridotite.Earth and Planetary Science Letters, Vol. 291, 1-4, pp. 215-227.MantleSubduction
DS201704-0641
2017
Spiegelman, M.W.Nakagawa, T., Spiegelman, M.W.Global scale water circulation in the Earth's mantle: implications for the mantle water budget in the early Earth.Earth and Planetary Science Letters, Vol. 464, pp. 189-199.MantleWater

Abstract: We investigate the influence of the mantle water content in the early Earth on that in the present mantle using numerical convection simulations that include three processes for redistribution of water: dehydration, partitioning of water into partially molten mantle, and regassing assuming an infinite water reservoir at the surface. These models suggest that the water content of the present mantle is insensitive to that of the early Earth. The initial water stored during planetary formation is regulated up to 1.2 OMs (OM = Ocean Mass; 1.4×1021 kg1.4×1021 kg), which is reasonable for early Earth. However, the mantle water content is sensitive to the rheological dependence on the water content and can range from 1.2 to 3 OMs at the present day. To explain the evolution of mantle water content, we computed water fluxes due to subducting plates (regassing), degassing and dehydration. For weakly water dependent viscosity, the net water flux is almost balanced with those three fluxes but, for strongly water dependent viscosity, the regassing dominates the water cycle system because the surface plate activity is more vigorous. The increased convection is due to enhanced lubrication of the plates caused by a weak hydrous crust for strongly water dependent viscosity. The degassing history is insensitive to the initial water content of the early Earth as well as rheological strength. The degassing flux from Earth's surface is calculated to be approximately O(1013) kg/yrO(1013) kg/yr, consistent with a coupled model of climate evolution and mantle thermal evolution.
DS201504-0222
2015
Spiegl, T.C.Spiegl, T.C., Paeth, H., Frimmel, H.E.Evaluating key parameters for the initiation of a Neoproterozoic Snowball Earth with a single Earth System Model of intermediate complexity.Earth and Planetary Science Letters, Vol. 415, April pp. 100-110.MantleModel
DS1990-0198
1990
Spies, B.Best, M., Spies, B.Recent developments in analysis and presentation of large dat a sets in mineral explorationGeophysics, The leading Edge of Exploration, Vol. 9, No. 9, September pp. 37-43GlobalComputers, Geophysics
DS201902-0304
2019
Spiess, R.Nimis, P., Nestola, F., Schiazza, M., Reali, R., Agrosi, G., Mele, D., Tempesta, G., Howell, D., Hutchison, M.T., Spiess, R.Fe-rich ferropericlase and magnesiowustite inclusions reflecting diamond formation rather than ambient mantle.Geology, Vol. 47, 1., pp. 27-30.South America, Brazildeposit - Juina

Abstract: At the core of many Earth-scale processes is the question of what the deep mantle is made of. The only direct samples from such extreme depths are diamonds and their inclusions. It is commonly assumed that these inclusions reflect ambient mantle or are syngenetic with diamond, but these assumptions are rarely tested. We have studied inclusion-host growth relationships in two potentially superdeep diamonds from Juina (Brazil) containing nine inclusions of Fe-rich (XFe ?0.33 to ?0.64) ferropericlase-magnesiowüstite (FM) by X-ray diffractometry, X-ray tomography, cathodoluminescence, electron backscatter diffraction, and electron microprobe analysis. The inclusions share a common [112] zone axis with their diamonds and have their major crystallographic axes within 3°-8° of those of their hosts. This suggests a specific crystallographic orientation relationship (COR) resulting from interfacial energy minimization, disturbed by minor post-entrapment rotation around [112] due to plastic deformation. The observed COR and the relationships between inclusions and diamond growth zones imply that FM nucleated during the growth history of the diamond. Therefore, these inclusions may not provide direct information on the ambient mantle prior to diamond formation. Consequently, a “non-pyrolitic” composition of the lower mantle is not required to explain the occurrence of Fe-rich FM inclusions in diamonds. By identifying examples of mineral inclusions that reflect the local environment of diamond formation and not ambient mantle, we provide both a cautionary tale and a means to test diamond-inclusion time relationships for proper application of inclusion studies to whole-mantle questions.
DS201902-0322
2019
Spiga, R.Spiga, R., Barberi, C., Bertini, I., Lazzarin, M., Nestola, F.The origin of water on Earth: stars or diamonds?Rendiconti Lincei. Scienze Fisische e Naturali *** In Eng, 8p. PdfMantlewater

Abstract: This contribution deals with two different hypotheses on the origin of superficial water on the Earth: the Endogenous hypothesis and the Exogenous one. They proposed that water either was brought to the surface of the Earth from the deep interior of the Earth or would have come to the Earth from celestial bodies that bombarded the planet billions of years ago. The evidence from recent astronomical and geological findings supporting the two alternative hypotheses will be discussed.
DS2001-1113
2001
Spikings, R.A.Spikings, R.A., Winkler, W., Seward, D., Handler, R.Along strike variations in the thermal and tectonic response of the continental Ecuadorian Andes- collisionEarth and Planetary Science Letters, Vol. 186, No. 1, Mar. 15, pp. 57-73.Andes, EcuadorTectonics, Geothermometry
DS1991-1065
1991
Spiller, D.E.Martinez, E., Spiller, D.E.Gravity magnetic seperationEngineering and Mining Journal, Vol. 192, No. 6, June pp. 16 EE, 16 GG. (2p.)United StatesMineral processing -general, Gravity magnetics
DS200512-0177
2005
Spinks, K.D.Cole, J.W., Milner, D.M., Spinks, K.D.Calderas and caldera structure: a review.Earth Science Reviews, Vol. 69, 1-2, pp. 1-26.GlobalCalderas
DS200712-0607
2007
Spior, B.LeBas, M.J., Xueming, Y., Taylor, R.N., Spior, B., Milton, J.A., Peishan, Z.New evidence from a calcite dolomite carbonatite dyke for the magmatic origin of the massive Bayan Obo ore bearing dolomite marble, Inner Mongolia China.Mineralogy and Petrology, Vol. 91, 3-4, pp. 287-China, MongoliaCarbonatite
DS2002-1315
2002
SpiridonovRazvozzhaeva, E.A., Prokofev, Spiridonov, MartikhaevPrecious metals and carbonaceous substance in ores of the Sukhoi Log deposit, Eastern Siberia, Russia.Geology of Ore Deposits, Vol.44,2,pp. 103-110.RussiaGold, carbon, metallogeny, Deposit - Sukhoi Log
DS201012-0736
2010
Spiridonov, E.M.Sokolova, E.L., Spiridonov, E.M., Vorobev, S.A.Cl bearing lizardite in metamorphosed kimberlites from the Udachnaya Vostochnaya pipe, Yakutia.Petrology, Vol. 18, 2, pp. 126-130.RussiaDeposit - Udachnaya
DS201012-0744
2010
Spiridonov, E.M.Spiridonov, E.M., Paulov, L.A., Sokolova, E.L., Vorobev, E.I., Agakhanov, A.A.Chlorine bearing lizardite from metakimberlite of the Udachanaya East pipe.Doklady Earth Sciences, Vol. 431, 1, pp. 403-405.Russia, YakutiaDeposit - Udachnaya East
DS201904-0768
2018
Spiridonov, E.M.Putintseva, E.V., Spiridonov, E.M.Ilmenite Group minerals in the Russia's oldest diamondiferous kimberlites of Kimozero, Karelia.Geology of Ore Deposits, Vol. 60, 7, pp. 625-635.Russiadeposit - Kimozero

Abstract: The paper discusses the morphology and compositional variations of ilmenite group minerals from kimberlites of two phases at the Kimozero locality, the oldest in Russia. Phenocrysts of Mn-rich picroilmenite and Fe-rich geikielite in kimberlites of both phases are similar in morphology and composition. Ilmenite from cement in the second-phase kimberlites enriched in Mg and rimming small regularly shaped chrome spinel phenocrysts is not present in the first-phase kimberlites. Ilmenite, manganilmenite, and Fe-bearing pyrophanite (22-24 wt % MnO) abundant in the cement of the second-phase kimberlites are twice as rich in Nb and substantially richer in Mn than ilmenite up to manganilmenite from the cement of the first-phase kimberlites. Ilmenite and manganilmenite of the first-phase kimberlites is enriched in Zn (up to 1.5 wt % ZnO). Ilmenite from the second-phase kimberlites contains up to 3 wt % Cr2O3. In Nb concentration, kimberlitic rocks of the Kimozero are similar to those found in other parts of the world (up to 3.5 wt % Nb2O5). Significant Mn-enrichment of the ilmenite group minerals is a common feature of Kimozero kimberlitic rocks. It is suggested that kimberlites in which all ilmenite group minerals—from megacrysts and phenocrysts to small segregations in the cement—are enriched in Me, formed with the participation of carbonatite melts with increased alkalinity.
DS1998-0845
1998
SpiritoLeckie, D.A., Nadon, Spirito, McCurdy, FriskeEvolution of fluvial landscapes in the Western Canada Foreland Basin; Late Jurassic to the modern...Geological Survey of Canada Open File, No. 2369Alberta, Northwest TerritoriesGeochemistry - regional stream sediment
DS1999-0458
1999
Spirito, W.A.McCurdy, M.W., Anglin, C.D., Spirito, W.A., Eddy, B.Geochemical surveys and interpretation. Briefly mentions diamondGeological Survey of Canada (GSC) Open File, No. 3714, pp. D1-34.. $ 50.00Northwest Territories, Nunavut, Bathurst IslandGeochemistry
DS201012-0569
2010
Spirito, W.A.Paulen, R.C., Adcock, S.W., Spirito, W.A., Chorlton, L.B., McClenaghan, M.B., Oviatt, Budulan, RobinsonsInnovative methods to search, download and display indicator mineral data: a new Tri-Territorial Indicator Mineral Database.38th. Geoscience Forum Northwest Territories, Abstract pp. 75-76.Canada, Northwest TerritoriesGEM database
DS201312-0712
2013
Spirito, W.A.Plouffe, A., McClenaghan, M.B., Paulen, R.C., McMartin, I., Campbell, J.E., Spirito, W.A.Quality assurance and quality control measures applied to indicator mineral studies at the Geological Survey of Canada.GSC Open file 7374 Ftp2.cits.rncan.gc.ca, pp. 13-20.CanadaQuality controls
DS201312-0875
2013
Spirito, W.A.Spirito, W.A., Adcock, S.W., Paulen, R.C.Managing geochemical data: challenges and best practices.GSC Open file 7374 Ftp2.cits.rncan.gc.ca, pp. 21-26.TechnologyGeochemistry
DS201412-0567
2013
Spirito, W.A.McClenaghan, M.B., Plouffe, A., McMartin, I., Campbell, J.E., Spirito, W.A., Paulen, R.C., Garrett, R.G., Hall, G.E.M.Till sampling and geochemical analytical protocols used by the Geological Survey of Canada.Geochemistry: Exploration, Environment, Analysis, Vol. 13, pp. 285-301.TechnologySampling
DS201412-0693
2013
Spirito, W.A.Plouffe, A., McClenaghan, M.B., Paulen, R.C., McMartin, I., Campbell, J.E., Spirito, W.A.Processing of glacial sediments for the recovery of indicator minerals: protocols used at the Geological Survey of Canada.Geochemistry: Exploration, Environment, Analysis, Vol. 13, pp. 303-316.TechnologySampling
DS1991-0273
1991
Spiro, B.Clarke, L.B., Le Bas, M.J., Spiro, B.Rare earth, trace element and stable isotope fractionation of carbonatites at Kruidfontein, TransvaalProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 49-51South AfricaCarbonatite, Sovite, Alvikite
DS1994-0314
1994
Spiro, B.Clarke, L.B., Le Bas, M.J., Spiro, B.Rare earth, trace element and stabe isotope fractionation of carbonatites at Kruidfontein, Transvaal.Proceedings of Fifth International Kimberlite Conference, Vol. 1, pp. 236-251.South AfricaRare earths, Carbonatite
DS1994-1874
1994
Spiro, B.Wall, F., Barreiro, B.A., Spiro, B.Isotopic evidence for late stage processes in carbonatites: rare earth mineralization in carbonatitesMineralogical Magazine, Vol. 58A, pp. 951-952. AbstractMalawiCarbonatite
DS1997-0655
1997
Spiro, B.Le Bas, M.J., Spiro, B., Xueming, Y.Oxygen, carbon and strontium isotope study of the carbonatitic dolomitehost of the Bayan Obo rare earth elements (REE) depositMineralogical Magazine, No. 407, August pp. 531-542.ChinaCarbonatite, Deposit - Bayan Obo
DS200812-0635
2008
Spiro, B.Le Bas, M.J., Xueming, Y., Taylor, R.N., Spiro, B., Milton, J.A., Peishan, Z.New evidence from a calcite dolomite carbonatite dyke for the magmatic origin of the massive Bayan Obo ore bearing dolomite marble, Inner Mongolia, China.Mineralogy and Petrology, Vol. 90, 3-4, pp. 223-248.China, MongoliaCarbonatite
DS201712-2676
2017
Spiro, B.Broom-Fendley, S., Wall, F., Spiro, B., Ullmann, C.V.Deducing the source and composition of rare earth mineralising fluids in carbonatites: insights from isotopic ( C,O,87Sr/86SR) dat a from Kangankunde, Malawi.Contributions to Mineralogy and Petrology, Vol. 172, 96Africa, Malawicarbonatite

Abstract: Carbonatites host some of the largest and highest grade rare earth element (REE) deposits but the composition and source of their REE-mineralising fluids remains enigmatic. Using C, O and 87Sr/86Sr isotope data together with major and trace element compositions for the REE-rich Kangankunde carbonatite (Malawi), we show that the commonly observed, dark brown, Fe-rich carbonatite that hosts REE minerals in many carbonatites is decoupled from the REE mineral assemblage. REE-rich ferroan dolomite carbonatites, containing 8-15 wt% REE2O3, comprise assemblages of monazite-(Ce), strontianite and baryte forming hexagonal pseudomorphs after probable burbankite. The 87Sr/86Sr values (0.70302-0.70307) affirm a carbonatitic origin for these pseudomorph-forming fluids. Carbon and oxygen isotope ratios of strontianite, representing the REE mineral assemblage, indicate equilibrium between these assemblages and a carbonatite-derived, deuteric fluid between 250 and 400 °C (?18O + 3 to + 5‰VSMOW and ?13C ? 3.5 to ? 3.2‰VPDB). In contrast, dolomite in the same samples has similar ?13C values but much higher ?18O, corresponding to increasing degrees of exchange with low-temperature fluids (< 125 °C), causing exsolution of Fe oxides resulting in the dark colour of these rocks. REE-rich quartz rocks, which occur outside of the intrusion, have similar ?18O and 87Sr/86Sr to those of the main complex, indicating both are carbonatite-derived and, locally, REE mineralisation can extend up to 1.5 km away from the intrusion. Early, REE-poor apatite-bearing dolomite carbonatite (beforsite: ?18O + 7.7 to + 10.3‰ and ?13C ?5.2 to ?6.0‰; 87Sr/86Sr 0.70296-0.70298) is not directly linked with the REE mineralisation.
DS201012-0643
2010
Spirov, I.Ruskov, T., Spirov, I., Georgieva, M., Yamamoto, S., Green, H.W., McCammon, C.A., Dobrzhinetskaya, L.F.Mossbauer spectroscopy studies of the valence state of iron in chromite from the Luobusa Massif of Tibet: implications for a highly reduced mantle.Journal of Metamorphic Geology, Vol. 28, 5, pp. 551-560.Asia, TibetMetasomatism
DS1983-0347
1983
Spitsyn, B.V.Karaseva, L.G., Karpukhina, T.A., Spitsyn, B.V.Epr Spectra of Atomic Hydrogen in Sythetic Diamonds.(russian)Zhurn. Fiz. Khim., (Russian), Vol. 57, No. 2, pp. 491-493RussiaDiamond Morphology
DS1988-0662
1988
Spitsyn, B.V.Spitsyn, B.V., Builov, L.L., Deryagin, B.V.Diamond and diamond like films: deposition from the vapor phase structure and propertiesProg. Cryst. Growth Charact, Vol. 17, No. 2, pp. 79-170GlobalCitation states in English and a Review, CVD Diamond application
DS202008-1382
2020
Spitzenberger, M.S.Conceicao, R.V., Marcon, V.H., Souza, M.R.W., Carniel, L.C., Quinteiro, R.V.S., Rovani, P., Mizusaki, A.M.P., Spitzenberger, M.S.Carbonatite/lamproite liquid imissibility in the Earth's mantle through the nefeline-diopside-kalsilite+-CO2, CH4, H2O diagram.Goldschmidt 2020, 1p. AbstractMantlelamproite

Abstract: The presence and speciation of volatile C-H-O elements in the silicate systems play an important role in the genesis of magmas on the Earth’s mantle, due to the fact that these elements, mainly in the form of H2O, CO2, CH4 and CxHy, decrease the solidi temperatures of source rocks, making magmatism possible in Earth’s present day thermal conditions [1]. Among those elements, carbon is the only element that changes its valence according to the oxygen fugacity (fO2) conditions of the environment, resulting in different speciation, as: CO3 -2, CO2, Cgraphite/diamond, CH4 or heavier hydrocarbons. In the present work, we are determining phase stability of minerals, water, CO2 and CH4 in the system Nefeline-Kalsilite-Diopside. Our experiments are conducted under 4.0 GPa and temperatures up to 1300°C, using a 1000 tonf hydraulic press coupled with toroidal chambers. Preliminary experiments performed at 1300°C and 4.0GPa (initial composition in the Olivine-Quartz- Kalsalite/Nepheline system: 40mol% Ol90, 40mol% Nph50Kls50 and 20mol% Qz, PH2O,CO2=Ptotal) resulted in the formation of forsterite (Fo90) in equilibrium with phlogopite (Phl), melt and volatile phases (CO2 and CH4). Closer to the Diopside vertice, the addition of CO3 to the sample resulted in a imisibility of a carbonatitic and a silicatic melt, in which the carbonititic melt is enriched in sodium, while the silcate melt is enriched in potassium. Appart from that, experiments in different parts of the diagram suggest compositions from nephelinite-kalsilitite to lamproites composition for the silicate melt in equilibrium with diopside (solid solution with omphacite) and phlogopite. This work is a continuation of previous work in the anhydrous diagram and future works will provide the addition of CH4 as the volatile phase
DS1995-2108
1995
Spivack, A.J.You, C.F., Spivack, A.J., Gieskes, J.M., RosenbauerExperimental study of boron geochemistry: implications for fluid processes in subduction zonesGeochimica et Cosmochimica Acta, Vol. 59, No. 12, pp. 2435-2442GlobalGeochemistry - experimental, Boron
DS1996-1581
1996
Spivack, A.J.You, C.-F., Castillo, P.R., Spivack, A.J.Trace element behaviour in hydrothermal experiments: implications for fluid processes at shallow depths..Earth and Planetary Science Letters, Vol. 140, No. 1-4, May 1, pp. 41-52MantlePetrology -experimental, Subduction zones
DS1998-1205
1998
Spivack, A.J.Ransom, B., Kastner, M., Spivack, A.J.Chlorine fluid cycling in subduction zones: evidence chloride concentrations and chlorine stable isotopes.Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1233-4.MantleSubduction
DS201112-0992
2011
Spivak, A.Spivak, A., Dubrovinskii, Yu., LitvinCongruent melting of calcium carbonate in a static experiment at 3500 K and 10-22 GPa: its role in the genesis of ultradeep diamonds.Doklady Earth Sciences, Vol. 439, 2, pp. 1171-1174.MantleUHP diamond genesis
DS201412-0515
2014
Spivak, A.Litvin, Yu., Spivak, A., Dubrovinsky, L.Evolution of the Earth's lower-mantle matter: stishovite paradox and origin of "super-deep" diamonds ( experiments at 24 Gpa)European High Pressure Research Group, Lyon France June 22-27., 1p. Abstract availableMantleStishovite
DS201509-0429
2015
Spivak, A.Spivak, A., Solopova, N., Dubrovinsky, L., Litvin, Y.Melting relations of multicompnent carbonate MgCO3-FeCO3-CaCO3-Na2CO3 system at 12-26 Gpa: application to deeper mantle diamond formation.Physics and Chemistry of Minerals, DOI 10.1007/ s00269-015-0765-6MantleMelting

Abstract: Carbonatic components of parental melts of the deeper mantle diamonds are inferred from their primary inclusions of (Mg, Fe, Ca, Na)-carbonate minerals trapped at PT conditions of the Earth’s transition zone and lower mantle. PT phase diagrams of MgCO3-FeCO3-CaCO3-Na2CO3 system and its ternary MgCO3-FeCO3-Na2CO3 boundary join were studied at pressures between 12 and 24 GPa and high temperatures. Experimental data point to eutectic solidus phase relations and indicate liquidus boundaries for completely miscible (Mg, Fe, Ca, Na)- and (Mg, Fe, Ca)-carbonate melts. PT fields for partial carbonate melts associated with (Mg, Fe)-, (Ca, Fe, Na)-, and (Na2Ca, Na2Fe)-carbonate solid solution phases are determined. Effective nucleation and mass crystallization of deeper mantle diamonds are realized in multicomponent (Mg, Fe, Ca, Na)-carbonatite-carbon melts at 18 and 26 GPa. The multicomponent carbonate systems were melted at temperatures that are lower than the geothermal ones. This gives an evidence for generation of diamond-parental carbonatite melts and formation of diamonds at the PT conditions of transition zone and lower mantle.
DS201601-0046
2015
Spivak, A.Spivak, A., Solopova, N., Dubrovinsky, L., Litvin, Y.Melting relations of multicomponent carbonate MgCO3-FeCO3-CaCO3-Na2CO3 system at 12-26 Gpa: application to deeper mantle diamond formation.Physics and Chemistry of Minerals, Vol. 42, pp. 817-824.MantleCarbonatite, diamond genesis

Abstract: Carbonatic components of parental melts of the deeper mantle diamonds are inferred from their primary inclusions of (Mg, Fe, Ca, Na)-carbonate minerals trapped at PT conditions of the Earth’s transition zone and lower mantle. PT phase diagrams of MgCO3-FeCO3-CaCO3-Na2CO3 system and its ternary MgCO3-FeCO3-Na2CO3 boundary join were studied at pressures between 12 and 24 GPa and high temperatures. Experimental data point to eutectic solidus phase relations and indicate liquidus boundaries for completely miscible (Mg, Fe, Ca, Na)- and (Mg, Fe, Ca)-carbonate melts. PT fields for partial carbonate melts associated with (Mg, Fe)-, (Ca, Fe, Na)-, and (Na2Ca, Na2Fe)-carbonate solid solution phases are determined. Effective nucleation and mass crystallization of deeper mantle diamonds are realized in multicomponent (Mg, Fe, Ca, Na)-carbonatite-carbon melts at 18 and 26 GPa. The multicomponent carbonate systems were melted at temperatures that are lower than the geothermal ones. This gives an evidence for generation of diamond-parental carbonatite melts and formation of diamonds at the PT conditions of transition zone and lower mantle.
DS201705-0850
2017
Spivak, A.Litvin, Y., Spivak, A.Ultrabasic basic change over primary inclusions in lower mantle diamonds: mineralogical and experimental evidence for crucial role of stishovite paradox.European Geosciences Union General Assembly 2017, Vienna April 23-28, 1p. 4785 AbstractMantleMelting

Abstract: Melting relations of the lower-mantle magmatic system MgO - FeO - CaO - SiO2 are characterized by peritectic reaction of bridgmanite (Mg,Fe)SiO3 and melt with formation of Fe-rich phases of periclase-wustite solid solutions (MgO•FeO)ss and stishovite SiO2. The reaction proceeds also in melts-solutions of lower-mantle diamond-parental system MgO - FeO - CaO - SiO2 - (Mg-Fe-Ca-Na-carbonate) - C. Xenoliths of lower mantle rocks were never found among the deep mantle derived materials. Estimation of lower-mantle mineralogy as ferropericlase+ bridgmanite+ Ca-perovskite association is inferred from high-pressure subsolidus experiments with ultrabasic pyrolite composition (Akaogi, 2007). The paradoxical in situ paragenesis of stishovite and ferropericlase as primary inclusions in lower-mantle diamonds (Kaminsky, 2012) takes its explanation from the bridgmanite peritectic reaction (effect of "stishovite paradox") (Litvin et al., 2014). Based on the data for inclusions, physico-chemical study on syngenesis of diamonds and primary inclusions has experimentally revealed the ferropericlase-bridgmanite-Ca-perovskite-stishovite-magnesiowustite-(Mg-Fe-Ca-Na-carbonate)-carbon compositions of the lower-mantle diamond-forming system .(Litvin et al., 2016). The generalized diagram of diamong-forming media characterizes the variable compositions of growths melts for diamonds and paragenetic phases and their genetic relationships with lower mantle matter, and it is the reason for genetic classifying primary inclusions. Fractional ultrabasic-basic evolution and continuous paragenetic transition from ultrabasic bridgmanite-ferropericlase to basic stishovite-magnesiowustite assemblages in the of lower-mantle diamond-parental melts-solutions are providing by the physico-chemical mechanism of stishovite paradox. References Akaogi M. (2007). Phase transformations of minerals in the transition zone and upper part of the lower mantle.
DS200612-1348
2006
Spivak, A.A.Spivak, A.A.Rigidity of tectonic structures in the central east European platform.Doklady Earth Sciences, Vol. 410, 7, pp. 1083-1086.EuropeTectonics
DS2000-0529
2000
Spivak, A.V.Kostrovitsky, S.I., Spivak, A.V.Approaches to create the model of kimberlite field formationIgc 30th. Brasil, Aug. abstract only 1p.Russia, YakutiaDiamond - genesis, Deposit - Alakit, Kuoik
DS2002-0955
2002
Spivak, A.V.Litvin, Y.A., Butvina, V.G., Spivak, A.V.Formation of natural diamonds in carbonate silicate and sulphide melts: the evidence from high pressure experiments.18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.75.Russia, ChinaUHP - mineralogy, Kokchetav, Dabie Shan
DS2003-0828
2003
Spivak, A.V.Litvin, Y.A., Spivak, A.V.Rapid growth of diamondite at the contact between graphite and carbonate melt:Doklady Earth Sciences, Vol. 391, 6a, pp. 888-891.GlobalDiamondite
DS2003-0830
2003
Spivak, A.V.Litvin, Yu.A., Spivak, A.V.Rapid growth of diamondite at the contact between graphite and carbonate melt:Doklady Earth Sciences, Vol. 391A, 6, July-August, pp. 888-891.GlobalPetrology
DS200412-1155
2003
Spivak, A.V.Litvin, Yu.A., Spivak, A.V.Rapid growth of diamondite at the contact between graphite and carbonate melt: experiments at 7.5 - 8.5 Gpa.Doklady Earth Sciences, Vol. 391A, 6, July-August, pp. 888-891.TechnologyPetrology
DS200412-1890
2004
Spivak, A.V.Spivak, A.V., Litvin, Yu.A.Diamond spontaneous and seeded growth in natural like carbonate carbon system: boundary conditions, kinetics, Nano aspects ( expLithos, ABSTRACTS only, Vol. 73, p. S106. abstractTechnologyDiamond nucleation
DS200612-1287
2005
Spivak, A.V.Shiryaev, A.A., Spivak, A.V., Litvin, Yu.A., Urusov, V.S.Formation of nitrogen A defects in diamond during growth in carbonate carbon solutions melts: experiments at 5.5-8.5 GPa.Doklady Earth Sciences, Vol. 403, 6, pp. 908-911.TechnologyExperimental petrology
DS200612-1349
2006
Spivak, A.V.Spivak, A.V., Shiryaev, A.A., Litvin, Yu.A.Growth of diamond in multicomponent carbonate - carbon melts: formation of the mixed C- and A-defects.International Mineralogical Association 19th. General Meeting, held Kobe, Japan July 23-28 2006, Abstract p. 138.MantleDiamond morphology
DS200812-1105
2008
Spivak, A.V.Spivak, A.V., Litvin, Y.A., Shushkanova, A.V., Litvin, V.Y., Shiryaev, A.A.Diamond formation in carbonate silicate sulfide carbon melts: Raman and IR microspectroscopy.European Journal of Mineralogy, Vol. 20, no. 3, pp. 341-347.TechnologyDiamond genesis
DS200912-0058
2009
Spivak, A.V.Bobrov, A.V., Spivak, A.V., Divaev, F.K., Dymshits, A.M., Litvin, Yu.A.High pressure melting relations of diamond forming carbonatites: formation of syngenetic peridotitic and eclogitic minerals ( experiments at 7.0 and 8.5 GPa).alkaline09.narod.ru ENGLISH, May 10, 2p. abstractTechnologyMelting
DS200912-0443
2009
Spivak, A.V.Litvin, Yu.A., Bobrov, A.V., Kuzyura, A.V., Spivak, A.V., Litvin, Y.Yu., Butvina, V.G.Mantle carbonatite magma in diamond genesis.Goldschmidt Conference 2009, p. A774 Abstract.MantleMelting
DS200912-0448
2009
Spivak, A.V.Livin, Yu.AQ., Spivak, A.V., Solopova, N.A., Litvin, V.Yu., Bobrov, A.V.Physicochemical factors of diamond and graphite formation in carbonatite melts on experimental grounds.alkaline09.narod.ru ENGLISH, May 10, 2p. abstractTechnologyExperimental melt
DS201112-0993
2011
Spivak, A.V.Spivak, A.V., Dubrovinskii, L.S., Litvin, Yu.A.Congruent melting of calcium carbonate in a static experiment at 3500 K and 10-22 GPa: its role in the genesis of untradeep diamonds.Doklady Earth Sciences, Vol. 439, 2, pp.1171-1174.TechnologyDiamond genesis
DS201112-0994
2011
Spivak, A.V.Spivak, A.V., Litvin, Yu.A., Dubrovinsky, L.S.Stability and breakdown of Ca13 CO3 melt combined with formation of 13 C diamond in static experiments up to 80 GPa and 4000K.Goldschmidt Conference 2011, abstract p.1923.TechnologyNatural super deep diamonds origin
DS201212-0698
2012
Spivak, A.V.Spivak, A.V., Litvin, Yu.A.Paragenetic relations of diamond with silicate and carbonate minerals in the carbonatite diamond system: experiments at 8.5 GpaGeochemistry International, Vol. 50, 3, pp. 217-226.TechnologyDiamond - carbonatite
DS201212-0699
2012
Spivak, A.V.Spivak, A.V., Litvin, Yu.A., Ovsyannikov, S.V., Dubrovinskaia, N.A., Dubrovinsky, L.S.Stability and breakdown of Ca13CO3 melt associated with formation of 13 C diamond in static high pressure experiments up to 43 Gpa and 3900K.Journal of Solid State Chemistry, Vol. 191, pp. 102-106.TechnologyDiamond - genesis
DS201412-0866
2013
Spivak, A.V.Solopova, N.A., Litvin, Yu.A., Spivak, A.V., Dubrovinskaia, N.A., Dubrovinsky, L.S., Urusov, V.S.The phase diagram of Na carbonate, an alkaline component of the growth medium of ultradeep diamonds.Doklady Earth Sciences, Vol. 451, 1, pp. 1106-1109.TechnologyUHP
DS201510-1808
2015
Spivak, A.V.Spivak, A.V.Genesis of superdeep diamond and inclusions from the Earth's lower mantle ( experimental research). IN RUSSIANInstitute of Experimental Mineralogy, Russian Academy of Sciences, Chernogolova ( Moscow) IN RUSSIAN, 216p. Available pdfMantleDiamond inclusions
DS201511-1882
2015
Spivak, A.V.Spivak, A.V., Solopova, N.A., Dubrovinsky, L.S., Litvin, Yu.A.The system MgCO3-FeCO3-CaCO3-Na2CO3 at 12-23 Gpa: phase relations and significance for the genesis of ultradeep diamonds.Doklady Earth Sciences, Vol. 464, 1, pp. 946-950.MantleDiamond genesis

Abstract: Physical-chemical experimental studies at 12-23 GPa of phase relationships within four-members carbonate system MgCO3-FeCO3-CaCO3-Na2CO3 and its marginal system MgCO3-FeCO3-Na2CO3 were carried out. The systems are quite representative for a set of carbonate phases from inclusions in diamonds within transitional zone and lower mantle. PT-phase diagrams of multicomponent carbonate systems are suggested. PT parameters of boundaries of their eutectic melting (solidus), complete melting (liquids) are established. These boundaries define area of partial melting. Carbonate melts are stable, completely mixable, and effective solvents of elemental carbon thus defining the possibility of ultra-deep diamonds generation.
DS201511-1883
2015
Spivak, A.V.Spivak, A.V., Solopova, N.A., Dubrovinsky, L.S., Litvin, Yu.A.Melting relations of multicomponent carbonate MgCOs-FeCO3-CaCO3-Na2COs system at 12-26 Gpa: application to deeper mantle diamond formation.Physics and chemistry of Minerals, Vol. 42, 10, pp. 817-824.TechnologyDiamond genesis - experimental
DS201706-1091
2017
Spivak, A.V.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.
DS201709-2057
2017
Spivak, A.V.Spivak, A.V., Litvin, Y.A., Dubrovinsky, L.S.Evolution of the lower mantle magma and diamond forming melts ( Experiment at 24-26 Gpa).Goldschmidt Conference, abstract 1p.Technologypetrology

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.
DS201810-2379
2018
Spivak, A.V.Spivak, A.V., Litvin, Y.A.Evolution of magmatic and diamond forming systems of the Earth's Lower Mantle.Springer, 108p. ISBN 978-3319785172Mantlemagmatism

Abstract: This book sheds valuable new light on the genetic mineralogy of lower-mantle diamonds and syngenetic minerals. It presents groundbreaking experimental results revealing the melting relations of ultrabasic and basic associations and a physicochemical peritectic mechanism of their evolution. The experimental investigations included here reveal the key multicomponent, multiphase oxide-silicate-carbonate-carbon parental media for lower-mantle diamonds and syngenetic minerals. Consequently, readers will find extensive information on the diamond-parental oxide-silicate-carbonate-carbon melts-solutions that supplement the general features of lower-mantle diamond genesis and the most efficient ultrabasic-basic evolution. The experimental results on physicochemical aspects, combined with analytical mineralogy data, make it possible to create a generalized composition diagram of the diamond-parental melts-solutions, there by completing the mantle-carbonatite concept for the genesis of lower-mantle diamonds and syngenetic minerals. This book addresses the needs of all researchers studying the Earth’s deepest structure, super-deep mineral formation including diamonds, and magmatic evolution.
DS201910-2302
2019
Spivak, A.V.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.
DS202009-1632
2020
Spivak, A.V.Iskrina, A., Spivak, A.V., Bobrov, A.V., Eremin, N.N., Marchenko, E.I., Dubrovinsky, L.S.Synthesis and crystal structures of new high-pressure phases CaAl2O4 and Ca2Al6O11.Lithos, Vol. 374-375, 6p. PdfMantlegarnet

Abstract: The phases of CaAl2O4 and Ca2Al6O11 were synthesized at 15 GPa and 1600 °C. Microprobe data gave formulae Ca1.003Al1.998O4 and Ca2.05Al5.97O11, on the basis of 4 and 11 oxygen atoms. The crystal structures have been refined by single-crystal X-ray diffraction. Orthorhombic unitcell parameters for CaAl2O4 are a = 8.8569(10) Å; b = 2.8561(4) Å; c = 10.2521(11) Å; V = 259.34(5) Å3; Z = 8 (space group Pnma). The Ca2Al6O11 phase was obtained for the first time. It crystallizes with a space group P42/mnm and has lattice parameters a = b = 11.1675(4) Å; c = 2.83180(10) Å; V = 353.16(2) Å3; Z = 2. A Raman spectrum was obtained for a new phase for the first time. Our results suggest that both studied phases are stable under the condition of the transition zone and can be considered as potential aluminum concentrators in the Earth's deep geospheres.
DS202109-1479
2021
Spivak, A.V.Litvin, Yu.A., Spivak, A.V., Kuzyura, A.V.Physicogeochemical evolution of melts of superplumes uplift from the lower mantle to the transition zone: experiment at 26 and 20 Gpa.Geochemistry International, Vol. 66, 7, pp. 607-629. pdfMantleplumes

Abstract: The Western Pacific Triangular Zone (WPTZ) is the frontier of a future supercontinent to be formed at 250 Ma after present. The WPTZ is characterized by double-sided subduction zones to the east and south, and is a region dominated by extensive refrigeration and water supply into the mantle wedge since at least 200 Ma. Long stagnant slabs extending over 1200 km are present in the mid-Mantle Boundary Layer (MBL, 410-660 km) under the WPTZ, whereas on the Core-Mantle Boundary (CMB, 2700-2900 km depth), there is a thick high-V anomaly, presumably representing a slab graveyard. To explain the D? layer cold anomaly, catastrophic collapse of once stagnant slabs in MBL is necessary, which could have occurred at 30-20 Ma, acting as a trigger to open a series of back-arc basins, hot regions, small ocean basins, and presumably formation of a series of microplates in both ocean and continent. These events were the result of replacement of upper mantle by hotter and more fertile materials from the lower mantle.
DS202203-0368
2021
Spivak, A.V.Timmerman, S., Spivak, A.V., Jones, A.P.Carbonatitic melts and their role in diamond formation in the deep earth.Elements, Vol. 17, pp. 321-326.Mantlediamond genesis

Abstract: Carbonatitic high-density fluids and carbonate mineral inclusions in lithospheric and sub-lithospheric diamonds reveal comparable compositions to crustal carbonatites and, thus, support the presence of carbon-atitic melts to depths of at least the mantle transition zone (~410-660 km depth). Diamonds and high pressure-high temperature (HP-HT) experiments confirm the stability of lower mantle carbonates. Experiments also show that carbonate melts have extremely low viscosity in the upper mantle. Hence, carbonatitic melts may participate in the deep (mantle) carbon cycle and be highly effective metasomatic agents. Deep carbon in the upper mantle can be mobilized by metasomatic carbonatitic melts, which may have become increasingly volumetrically significant since the onset of carbonate subduction (~3 Ga) to the present day.
DS200812-0992
2008
Spivakov, S.V.Sabulov, S.M., Sabulukova, L.I., Stegnitsky, Yu.B., Karpenko, M.A., Spivakov, S.V.Volcanic rocks of the Nyurbinskaya pipe: a portrayal of regional upper mantle evolution from the Riphean to the Carboniferous time, and its geodynamic relationship.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., 2008 pp. 71-103.Russia, SiberiaDeposit - Nyurbinskaya
DS201810-2346
2018
Spival, A.V.Litvin, Yu.A., Kuzyura, A.V., Varlamov, D.A., Bovkun, A.V., Spival, A.V., Garanin, V.K.Interaction of kimberlite magma with diamonds upon uplift from the upper mantle to the Earth's crust.Geochemistry International, Vol. 56, 9, pp. 881-900.Russiadeposit - Nyurbinskaya

Abstract: Interaction between a melt of kimberlite from the Nyurbinskaya pipe (Yakutia) and natural monocrystalline diamonds was studied experimentally at 0.15 GPa and 1200-1250°C in high-pressure and high-temperature Ar gas “bombs.” The loss of diamond weight with slight surface dissolution of diamonds in a Ca carbonate-bearing kimberlite melt over the course of 2 h (the period of kimberlite transport from upper-mantle diamond-forming chambers to the crustal cumulative centers) is 3-4.5%. In 4 and 7-8 days (under the conditions of crustal cumulative centers), the weight of diamond decreases with remarkable bulk dissolution by 13.5 and 24.5-27.5%, respectively. In the run at 0.15 GPa and 1200°C kimberlite and ilmenite (added) melts interact to produce perovskite melt. Both of the melts, rich in titanium minerals, are immiscible with kimberlite melt and therefore cannot influence the diamond dissolution kinetics in the kimberlite melt. The experimental results suggest that precisely the dissolution processes for thermodynamically metastable diamonds in silicate-carbonate kimberlitic magmas are responsible for the effective decrease in the diamond potential of kimberlite deposits. The paper discusses the physicochemical reasons for the decrease in the kimberlite diamond potential during the chemically active history of diamond genesis: from upper-mantle chambers to the explosive release of diamonds and kimberlite material from cumulative centers to the Earth’s surface. The data on experimental physicochemical studies of the origin, analytical mineralogy of inclusions, and isotope geochemistry of diamonds are correlated.
DS1859-0039
1828
Spix, J.B.VONSpix, J.B.VON, Martius, C.F.P. VON.Reise in BrasilienMuenchen: Lentner., 2 VOLS., 885P., ( DIAMONDS Brasil Vol. 2, PP. 429-484 ). XERBrazilTravelogue
DS1995-0209
1995
Spohn, T.Breuer, D., Spohn, T.Possible flush instability in mantle convection at the Archean Proterozoictransition.Nature, Vol. 378, Dec. 7, pp. 608-610.MantleCraton, Archean, Mantle convection
DS201904-0745
2019
Spohn, T.Honing, D., Tosi, N., Hansen-Goos, H., Spohn, T.Bifurcation in the growth of continental crust. (Water-land ratio)Physics of the Earth and Planetary Interiors, Vol. 287, pp. 37-50.Mantleplate tectonics

Abstract: Is the present-day water-land ratio a necessary outcome of the evolution of plate tectonic planets with a similar age, volume, mass, and total water inventory as the Earth? This would be the case - largely independent of initial conditions - if Earth’s present-day continental volume were at a stable unique equilibrium with strong self-regulating mechanisms of continental growth steering the evolution to this state. In this paper, we question this conjecture. Instead we suggest that positive feedbacks in the plate tectonics model of continental production and erosion may dominate and show that such a model can explain the history of continental growth. We investigate the main mechanisms that contribute to the growth of the volume of the continental crust. In particular, we analyze the effect of the oceanic plate speed, depending on the area and thickness of thermally insulating continents, on production and erosion mechanisms. Effects that cause larger continental production rates for larger values of continental volume are positive feedbacks. In contrast, negative feedbacks act to stabilize the continental volume. They are provided by the increase of the rate of surface erosion, subduction erosion, and crustal delamination with the continental volume. We systematically analyze the strengths of positive and negative feedback contributions to the growth of the continental crust. Although the strengths of some feedbacks depend on poorly known parameters, we conclude that a net predominance of positive feedbacks is plausible. We explore the effect of the combined feedback strength on the feasibility of modeling the observed small positive net continental growth rate over the past 2-3 billion years. We show that a model with dominating positive feedbacks can readily explain this observation in spite of the cooling of the Earth’s mantle acting to reduce the continental production rate. In contrast, explaining this observation using a model with dominating negative feedbacks would require the continental erosion and production rates to both have the same or a sufficiently similar functional dependence on the thermal state of the mantle, which appears unreasonable considering erosion to be largely dominated by the surface relief and weathering. The suggested scenario of dominating positive feedbacks implies that the present volume of the continental crust and its evolution are strongly determined by initial conditions. Therefore, exoplanets with Earth-like masses and total water inventories may substantially differ from the Earth with respect to their relative land/surface ratios and their habitability.
DS1994-0008
1994
Spooner, E.T.C.Abraham, A.P.G., Davis, D.W., Kamo, S.L., Spooner, E.T.C.Geochronlogical constraints on late Archean magmatism deformation and gold quartz vein mineralization AnialikCanadian Journal of Earth Sciences, Vol. 31, No. 8, Aug. pp. 1365-1383Northwest TerritoriesGreenstone belt, gold, deformation, Anialik River
DS1995-0005
1995
Spooner, E.T.C.Abraham, A.P.G., Spooner, E.T.C.Late Archean regional deformation and structural controls on gold quartzvein mineralization Slave ProvinceCanadian Journal of Earth Sciences, Vol. 32, No. 8, Aug. pp. 1132-1171Northwest TerritoriesGold, structure, tectonics, Anialik greenstone belt
DS1990-0591
1990
Spooner, J.Grace, K., Spooner, J.The economics of the rare earth elementsThe Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Annual Meeting Paper preprint, No. 8, 15pGlobalEconomics, Rare earths-excellent overview
DS1997-1093
1997
Spped, R.C.Spped, R.C., Sharp, W.D., Foland, K.A.Late Paleozoic granitoid gneisses of northeastern Venezuela and the North america Gondwana collision zoneJournal of Geology, Vol. 105, No. 4, July, pp. 475-470VenezuelaTectonics
DS1920-0404
1928
Sprague, C.Sprague, C.Diamond Production in South AfricaStone And Webster Journal, Vol. 43, OCTOBER PP. 517-527.South AfricaMining Engineering
DS200612-1350
2006
Sprague, K.Sprague, K., De Kemp, E., Wong, W., McGaughey, J., Perron, G., Barrie, T.Spatial targeting using queries in a 3 D GIS environment with application to mineral exploration.Computers & Geosciences, Vol.32, 3, pp. 396-418.TechnologyComputer - programs
DS201201-0854
2011
Sprague, M.R.Lee, K.C., Sprague, M.R., Sussman, B.J., Nunn, J., Langford, N.K., Jin, X-M., Champoin, T., et al.Entangling microscopic diamonds at room temperature. ( quantum technology)Science, Vol. 334, no. 6060, Dec. 2, pp. 1253-1256.TechnologyQuantum state of diamonds
DS2001-0545
2001
SprattJones, A.G., Ferguson, Chave, Evans, SprattSlave electromagnetic studiesSlave-Kaapvaal Workshop, Sept. Ottawa, 2p. abstractNorthwest TerritoriesGeophysics - electromagnetic
DS200512-0284
2005
SprattFerguson, I.J., Craven, J.A., Kurtz, R.D., Boerner, D.E., Bailey, Wu, Orellana, Spratt, Wennberg, NortonGeoelectric response of Archean lithosphere in the western Superior Province, central Canada.Physics of the Earth and Planetary Interiors, Vol. 150, 1-3, May 16, pp. 123-143.Canada, OntarioGeophysics - magnetotelluric, North Caribou terrane
DS200712-0404
2006
SprattHamilton, M.P., Jones, A.G., Evans, R.L., Evans, S., Fourie, C.J.S., Mountford, SprattElectrical anisotropy of South African lithosphere compared with seismic from shear wave splitting analyses.Physics of the Earth and Planetary Interiors, Vol. 158, 2-4, Oct. 16, pp. 226-239.Africa, South AfricaGeophysics - seismics
DS201112-0312
2011
SprattEvans, R.L., Jones, A.G., Garcia, X., Muller, M., Hamilton, Evans, Fourie, Spratt, Webb, Jelsma, HutchinsElectrical lithosphere beneath the Kaapvaal craton, southern Africa.Journal of Geophysical Research, Vol. 116, B4, B04105.Africa, South AfricaGeophysics - seismics
DS201112-0812
2011
SprattPolyakova, 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
DS1993-1228
1993
Spratt, D.A.Peterson, T.D., Spratt, D.A.Analcite bearing igneous rocks from the Crowsnest Formation, southwesternAlberta.Geological Survey Canada Paper, No. 93-1C, pp. 51-57.AlbertaIgneous rocks
DS1994-0993
1994
Spratt, D.A.Lawton, D.C., Spratt, D.A., Hopkins, J.C.Tectonic wedging beneath the Rocky Mountain foreland basin, Alberta, Canada.Geology, Vol. 22, No. 6, June pp. 519-522.AlbertaStructure, Tectonics
DS2001-0547
2001
Spratt, J.Jones, A.G., Snyder, D., Ford, K.L., Spratt, J., EvansGeophysical experiments in central Baffin Island29th. Yellowknife Geoscience Forum, Nov. 21-23, abstract p. 38-9.Northwest Territories, Baffin IslandGeophysics, Trans Hudson Orogen
DS200412-0927
2003
Spratt, J.Jones, A.G., Lezaeta, P., Ferguson, I.J., Chave, A.D., Evans, R.L., Garcia, X., Spratt, J.The electrical structure of the Slave Craton.Lithos, Vol. 71, 2-4, pp. 505-527.Canada, NunavutGeophysics - seismics
DS200512-0273
2005
Spratt, J.Evans, S., Jones, A.G., Spratt, J., Katsube, J.Central Baffin Island electromagnetic experiment (CBEX): mapping the North American central plains (NACP) conductivity anomaly in the Canadian arctic.Physics of the Earth and Planetary Interiors, Vol. 150, 1-3, May 16, pp. 107-122.Canada, Nunavut, Baffin IslandTrans Hudson Orogeny, geophysics - magnetotelluric
DS200812-1305
2008
Spratt, J.Zaitsev, A.N., Keller, J., Spratt, J., Perova, E.N., Kearlsey, A.Nyereite pissonite calcite shortite relationships in altered natrocarbonatites, Oldoinyo Lengai, Tanzania.Canadian Mineralogist, Vol. 46, 4, August pp.Africa, TanzaniaCarbonatite
DS200912-0845
2009
Spratt, J.Yusupov, R.G., Stanley, C.J., Welch, M.D., Spratt, J., Cressey, G., Rusmsey, M.S., Seltmann, R., IgamberdievMavlyanovite, Mn5813: a new mineral species from a lamproite diatreme, Chatkal Ridge, Uzbekistan.Mineralogical Magazine, Vol. 73, 1, Feb. pp. 43-50.RussiaLamproite mineralogy
DS201012-0883
2010
Spratt, J.Zaitsev, N., Williams, C.T., Britvin,S.N., Kuznetsova, I.V., Spratt, J., Petrov, S.V., Keller, J.Kerimasite Ca3ZR2(Si)O12, a new garnet from carbonatites of Kerimasi volcano and surrounding explosion craters, northern Tanzania.Mineralogical Magazine, Vol. 74, pp. 803-820.Africa, TanzaniaCarbonatite
DS201012-0886
2010
Spratt, J.Zaitssev, A.N., Wenzel, T., Markl, G., Spratt, J., Petrov, S.V., Williams, C.T.Sadiman volcano, Crater Highlands, Tanzania: does it really contain melilitites and carbonatites or is it just a phonolite nephelinite volcano?International Mineralogical Association meeting August Budapest, abstract p. 559.Africa, TanzaniaPetrology
DS201112-0958
2011
Spratt, J.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
DS201201-0861
2011
Spratt, J.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
DS201312-0876
2013
Spratt, J.Spratt, J.Electrical resistivity of the Rae craton lithosphere.GEM Diamond Workshop Feb. 21-22, Noted onlyCanadaGeophysics
DS201412-1015
2014
Spratt, J.Zaitsev, A.N., Williams, C.T., Jeffreis, T.E., Strekopytov, S., Moutte, J., Ivashchenkova, O.V., Spratt, J., Petrov, S.V., Wall, F., Seltmann, R., Borozdin, A.P.Rare earth elements in phoscorites and carbonatites of the Devonian Kola alkaline province, Russia: examples from Kovdor, Khibina, Vuoriyarvi and Turiy Mys complexes.Ore Geology Reviews, Vol. 64, pp. 204-225.Russia, Kola PeninsulaCarbonatite
DS201412-1017
2014
Spratt, J.Zaitsev, A.N., Williams, C.T., Jeffries, T.E., Strekopytov, S., Moutte, J., Ivashchenkova, O.V., Spratt, J., Petrov, S.V., Wall, F., Seltmann, R., Borozdin, A.P.Rare earth elements in phoscorites and carbonatites of the Devonian Kola alkaline province, Russia: examples from Kovdor, Khibina, Vuoriyarvi and Turiy Mys complexes.Ore Geology Reviews, Vol. 61, pp. 204-225.Russia, Kola PeninsulaCarbonatite
DS201412-1019
2014
Spratt, J.Zaitsev, A.N., Williams, C.T., Jeffries, T.E., Strekopytov, S., Moutte, J., Ivashchenkova, O.V., Spratt, J., Petrov, S.V., Wall, F., Seltmann, R., Borozdin, A.P.Rare earth elements in phoscorites and carbonatites of the Devonian Kola alkaline province, Russia: examples from Kovdor, Khibina, Vuoriyarvi and Turiy Mys complexes.Ore Geology Reviews, in press availableRussia, Kola PeninsulaCarbonatite
DS201506-0256
2015
Spratt, J.Bell, K., Zaitsev, A.N., Spratt, J., Frojdo, S., Rukhlov, A.S.Elemental, lead and sulfur isotopic compositions of galena from Kola carbonatites, Russia - implications for melt and mantle evolution.Mineralogical Magazine, Vol. 79, 2, pp. 219-241.RussiaCarbonatite, Kola

Abstract: Galena from four REE-rich (Khibina, Sallanlatvi, Seblyavr, Vuoriyarvi) and REE-poor (Kovdor) carbonatites, as well as hydrothermal veins (Khibina) all from the Devonian Kola Alkaline Province of northwestern Russia was analysed for trace elements and Pb and S isotope compositions. Microprobe analyses show that the only detectable elements in galena are Bi and Ag and these vary from not detectable to 2.23 and not detectable to 0.43 wt.% respectively. Three distinct galena groups can be recognized using Bi and Ag contents, which differ from groupings based on Pb isotope data. The Pb isotope ratios show significant spread with 206Pb/204Pb ratios (16.79 to 18.99), 207Pb/204Pb (15.22 to 15.58) and 208Pb/204Pb ratios (36.75 to 38.62). A near-linear array in a 207Pb/204Pb vs. 206Pb/204Pb ratio diagram is consistent with mixing between distinct mantle sources, one of which formed during a major differentiation event in the late Archaean or earlier. The S isotopic composition (?34S) of galena from carbonatites is significantly lighter (–-6.7 to -–10.3% Canyon Diablo Troilite (CDT) from REE-rich Khibina, Seblyavr and Vuoriyarvi carbonatites, and - 3.2% CDT from REE-poor Kovdor carbonatites) than the mantle value of 0%. Although there is no correlation between S and any of the Pb isotope ratios, Bi and Ag abundances correlate negatively with ?34S values. The variations in the isotopic composition of Pb are attributed to partial melting of an isotopically heterogeneous mantle source, while those of ?34S (together with Bi and Ag abundances) are considered to be process driven. Although variation in Pb isotope values between complexes might reflect different degrees of interaction between carbonatitic melts and continental crust or metasomatized lithosphere, the published noble gas and C, O, Sr, Nd and Hf isotopic data suggest that the variable Pb isotope ratios are best attributed to isotopic differences preserved within a sub-lithospheric mantle source. Different Pb isotopic compositions of galena from the same complex are consistent with a model of magma replenishment by carbonatitic melts/fluids each marked by quite different Pb isotopic compositions.
DS201610-1884
2016
Spratt, J.Lindsay, M., Spratt, J., Occhipinti, S., Aitken, A., Dentith, M., Metelka, V., Hollis, J., Tyler, I.Integrated interpretation of magnetotelluric and potential field data: assessing the northeast Kimberley region. ( no mention of kimberlites)ASEG-PESA-AIG 2016 25th Geophysical Conference, Abstract 4p.AustraliaGeophysics
DS201706-1113
2017
Spratt, J.Zaitsev, A.N., Zhitova, E.S., Spratt, J., Zolotarev, A.A., Krivovichev, S.V.Isolueshite, NaNb03, from the Kovdor carbonatite, Kola Peninsula, Russia: composition, crystal structure and possible formation scenarios.Neues Jahrbuch fur Mineralogie, Vol. 194, 2, pp. 165-173.Russia, Kola Peninsuladeposit - Kovdor

Abstract: Isolueshite, a cubic complex oxide with the formula NaNbO3, occurs as euhedral crystals 0.4 - 0.7 mm in size in calcite carbonatite, Kovdor ultrabasic-alkaline complex (Kola, Russia). Average composition of isolueshite, based on 40 analyses by wavelength-dispersive electron microprobe is (Na0.84Ca0.07Sr0.01La0.01Ce0.01)?0.95(Nb0.90Ti0.11)?1.01O3. Minor and trace elements are Ti (4.1- 6.8 wt.% TiO2), REEs (1.8 - 4.0 wt.% REE2O3), Ca (1.7- 3.3 wt.% CaO), Zr (0.1- 0.8 wt.% ZrO2), Sr (0.3 - 0.4 wt.% SrO), Th (0.1- 0.5 wt.% ThO2), Fe (0.1- 0.2 wt.% Fe2O3) and Ta (0.1 wt.% Ta2O5). The crystal structure of isolueshite was refined to an agreement index (R1) of 0.028 for 82 unique reflections with |F0| ? 4 ?(F). The mineral is cubic, Pm3-m, a = 3.9045(5) Å and V = 59.525(13) Å3. The diffraction pattern of the crystal contains only regular and strong Bragg reflections with no signs of diffuse scattering. There are two sites in the crystal structure: A is 12-coordinated (A-O = 2.556(3) Å) and located at the corners of the cubic primitive cell and B is situated in the center of the unit-cell and has an octahedral coordination. The crystal-chemical formula based on the structure refinement is (Na0.84(1)Ca0.16(1))(Nb0.88(1)Ti0.12(1))O3. We suggest that isolueshite is a quenched (kinetically favored) polymorph of lueshite that formed as a result of rapid crystallization due to the sudden drop in temperature and/or pressure.
DS201805-0977
2018
Spratt, J.Smith, M., Kynicky, J., Xu, C., Song, W., Spratt, J., Jeffries, T., Brtnicky, M., Kopriva, A., Cangelosi, D.The origin of secondary heavy rare earth element enrichment in carbonatites: constraints from the evolution of the Huanglongpu district, China.Lithos, Vol. 308-309, pp. 65-82.Chinacarbonatite

Abstract: The silico?carbonatite dykes of the Huanglongpu area, Lesser Qinling, China, are unusual in that they are quartz-bearing, Mo-mineralised and enriched in the heavy rare earth elements (HREE) relative to typical carbonatites. The textures of REE minerals indicate crystallisation of monazite-(Ce), bastnäsite-(Ce), parisite-(Ce) and aeschynite-(Ce) as magmatic phases. Burbankite was also potentially an early crystallising phase. Monazite-(Ce) was subsequently altered to produce a second generation of apatite, which was in turn replaced and overgrown by britholite-(Ce), accompanied by the formation of allanite-(Ce). Bastnäsite and parisite where replaced by synchysite-(Ce) and röntgenite-(Ce). Aeschynite-(Ce) was altered to uranopyrochlore and then pyrochlore with uraninite inclusions. The mineralogical evolution reflects the evolution from magmatic carbonatite, to more silica-rich conditions during early hydrothermal processes, to fully hydrothermal conditions accompanied by the formation of sulphate minerals. Each alteration stage resulted in the preferential leaching of the LREE and enrichment in the HREE. Mass balance considerations indicate hydrothermal fluids must have contributed HREE to the mineralisation. The evolution of the fluorcarbonate mineral assemblage requires an increase in aCa2+ and aCO32? in the metasomatic fluid (where a is activity), and breakdown of HREE-enriched calcite may have been the HREE source. Leaching in the presence of strong, LREE-selective ligands (Cl?) may account for the depletion in late stage minerals in the LREE, but cannot account for subsequent preferential HREE addition. Fluid inclusion data indicate the presence of sulphate-rich brines during alteration, and hence sulphate complexation may have been important for preferential HREE transport. Alongside HREE-enriched magmatic sources, and enrichment during magmatic processes, late stage alteration with non-LREE-selective ligands may be critical in forming HREE-enriched carbonatites.
DS202104-0619
2021
Spratt, J.Zaitsev, A.N., Spratt, J., Shtukenberg, A.G., Zolotarev, A.A., Britvin, S.N., Petrov, S.V., Kuptsova, A.V., Antonov, A.V.Oscillatory- and sector zoned pyrochlore from carbonatites of the Kerimasi volcano, Gregory rift, Tanzania.Mineralogical Magazine, Vol. Pp. 1-22. pdfAfrica, Tanzaniacarbonatite

Abstract: The Quaternary carbonatite-nephelinite Kerimasi volcano is located within the Gregory rift in northern Tanzania. It is composed of nephelinitic and carbonatitic pyroclastic rocks, tuffs, tuff breccias and pyroclastic breccias, which contain blocks of different plutonic (predominantly ijolite) and volcanic (predominantly nephelinite) rocks including carbonatites. The plutonic and volcanic carbonatites both contain calcite as the major mineral with variable amounts of magnetite or magnesioferrite, apatite and forsterite. Carbonatites also contain accessory baddeleyite, kerimasite, pyrochlore and calzirtite. Zr and Nb minerals are rarely observed in rock samples, though they are abundant in eluvial deposits of carbonatite tuff/pyroclastic breccias in the Loluni and Kisete craters. Pyrochlore, ideally (CaNa)Nb 2 O 6 F, occurs as octahedral and cubo-octahedral crystals up to 300 ?m in size. Compositionally, pyrochlore from Loluni and Kisete differs. The former is enriched in U (up to 19.4 wt.% UO 2 ), light rare earth elements (up to 8.3 wt.% LREE 2 O 3 ) and Zr (up to 14.4 wt.% ZrO 2 ), and the latter contains elevated Ti (up to 7.3 wt.% TiO 2 ). All the crystals investigated were crystalline, including those with high U content ( a = 10.4152(1) Å for Loluni and a = 10.3763(1) Å for Kisete crystals). They have little or no subsolidus alteration nor low-temperature cation exchange ( A -site vacancy up to 1.5% of the site), and are suitable for single-crystal X-ray diffraction analysis ( R 1 = 0.0206 and 0.0290; for all independent reflections for Loluni and Kisete crystals, respectively). Observed variations in the pyrochlore composition, particularly Zr content, from the Loluni and Kisete craters suggest crystallisation from compositionally different carbonatitic melts. The majority of pyrochlore crystals studied exhibit exceptionally well-preserved oscillatory- and sometimes sector-type zoning. The preferential incorporation of smaller and higher charged elements into more geometrically constrained sites on the growing surfaces explains the formation of the sector zoning. The oscillatory zoning can be rationalised by considering convectional instabilities of carbonatite magmas during their emplacement.
DS202109-1496
2021
Spratt, J.Zaitsev, A.N., Spratt, J., Shtukenberg, A.G., Zolotarev, A.A., Britvin, S.N., Petrov, S.V., Kuptsova, A.V., Antonov, A.V.Oscillatory- and select-zoned pyrochlore from carbonatites of the Kerimasi volcano, Gregory Rift, Tanzania.Mineralogical Magazine, Vol. 85, 4, pp. 532-553.Africa, Tanzaniadeposit - Kerimasi

Abstract: The Quaternary carbonatite-nephelinite Kerimasi volcano is located within the Gregory rift in northern Tanzania. It is composed of nephelinitic and carbonatitic pyroclastic rocks, tuffs, tuff breccias and pyroclastic breccias, which contain blocks of different plutonic (predominantly ijolite) and volcanic (predominantly nephelinite) rocks including carbonatites. The plutonic and volcanic carbonatites both contain calcite as the major mineral with variable amounts of magnetite or magnesioferrite, apatite and forsterite. Carbonatites also contain accessory baddeleyite, kerimasite, pyrochlore and calzirtite. Zr and Nb minerals are rarely observed in rock samples, though they are abundant in eluvial deposits of carbonatite tuff/pyroclastic breccias in the Loluni and Kisete craters. Pyrochlore, ideally (CaNa)Nb 2 O 6 F, occurs as octahedral and cubo-octahedral crystals up to 300 ?m in size. Compositionally, pyrochlore from Loluni and Kisete differs. The former is enriched in U (up to 19.4 wt.% UO 2 ), light rare earth elements (up to 8.3 wt.% LREE 2 O 3 ) and Zr (up to 14.4 wt.% ZrO 2 ), and the latter contains elevated Ti (up to 7.3 wt.% TiO 2 ). All the crystals investigated were crystalline, including those with high U content ( a = 10.4152(1) Å for Loluni and a = 10.3763(1) Å for Kisete crystals). They have little or no subsolidus alteration nor low-temperature cation exchange ( A -site vacancy up to 1.5% of the site), and are suitable for single-crystal X-ray diffraction analysis ( R 1 = 0.0206 and 0.0290; for all independent reflections for Loluni and Kisete crystals, respectively). Observed variations in the pyrochlore composition, particularly Zr content, from the Loluni and Kisete craters suggest crystallisation from compositionally different carbonatitic melts. The majority of pyrochlore crystals studied exhibit exceptionally well-preserved oscillatory- and sometimes sector-type zoning. The preferential incorporation of smaller and higher charged elements into more geometrically constrained sites on the growing surfaces explains the formation of the sector zoning. The oscillatory zoning can be rationalised by considering convectional instabilities of carbonatite magmas during their emplacement.
DS200512-1034
2005
Spratt, J.E.Spratt, J.E., Jones, A.G., Nelson, K.D., Unsworth, M.J., INDEPTH MT TeamCrustal structure of the India - Asia collision zone, southern Tibet, from INDEPTH MT investigations.Physics of the Earth and Planetary Interiors, India, Asia, TibetGeophysics, EM and magnetotelluric
DS200612-0524
2006
Spratt, J.E.Hamilton, M.P., Jones, A.G., Evans, R.L., Evans, S., Fourie, C.J.S., Garcia, X., Mountford, A., Spratt, J.E., SAMTEX MTElectrical anisotropy of South African lithosphere compared with seismic anisotropy from shear wave splitting analyses.Physics of the Earth and Planetary Interiors, In press, availableAfrica, South AfricaGeophysics - magnetotellurics
DS200912-0723
2009
Spratt, J.E.Spratt, J.E., Jones, A.G., Jackson, V.A., Collins, L., Avdeeva, A.Lithospheric geometry of the Wopmay orogen from a Slave Craton to Bear province magnetotelluric transect.Journal of Geophysical Research, Vol. 114, B1 B01101.CanadaGeophysics - magnetotellurics
DS201412-0434
2014
Spratt, J.E.Jones, A.G., Ledo, J., Ferguson, I.J., Craven, J.A., Unswrth, M.J., Chouteau, M., Spratt, J.E., Enkin, R.The electrical resistivity of Canada's lithosphere and correlation with other parameters: contributions from lithoprobe and other programmes.Canadian Journal of Earth Sciences, Vol. 51, 6, pp. 573-617.CanadaGeophysics
DS201412-0878
2013
Spratt, J.E.Spratt, J.E., Skulski, T., Craven, J.A., Jones, A.G., Snyder, D.B., Kiyan, D.Magnetotelluric investigations of the lithosphere beneath the central Rae craton, maIn land Nunavut, Canada.Journal of Geophysical Research, Vol. 119, pp. 2415-2439.Canada, NunavutGeophysics - magnetotellurics
DS201212-0810
2012
Spratt, W.J.Zaitsev, A.N., Marks, M.A.W., Wenzel, T., Spratt, W.J., Sharygin, V.V., Strekoptov, G.M.Mineralogy, geochemistry and petrology of the phonolitic to nephelinitic Sadiman volcano, Crater Highlands, Tanzania.Lithos, Vol. 152, pp. 66-83.Africa, TanzaniaNephelinite
DS1996-0872
1996
Spray, J.Magloughlin, J., Chester, F.M., Spray, J.Fine grained fault rocks... overview of Penrose conferenceGsa Today, Vol. 6, No. 4, April pp. 33-37GlobalTectonics, Fault rock genesis, mechanisms, deformation
DS1988-0663
1988
Spray, J.G.Spray, J.G.Thrust related metamorphism beneath the Shetland Islands oceanic northeast ScotlandCanadian Journal of Earth Sciences, Vol. 25, No. 11, November pp. 1760-1776ScotlandTectonics, Oceanic
DS1988-0664
1988
Spray, J.G.Spray, J.G.Retrograde eclogite from Mont Albert, gaspe, Quebec, DiscussionCanadian Journal of Earth Sciences, Vol. 25, pp. 1542-43.QuebecEclogite
DS1992-1461
1992
Spray, J.G.Spray, J.G.A physical basis for the frictional melting of some rock-forming mineralsTectonophysics, Vol. 204, No. 3-4, April 15, pp. 203-222GlobalRock-forming minerals, Tectonics
DS1993-1520
1993
Spray, J.G.Spray, J.G.Viscosity determinations of some frictionally generated silicate melts:implications for fault zone rheology at high strain ratesJournal of Geophysical Research, Vol. 98, No. B5, May 10, pp. 8053-8068Scotland, WashingtonStructure, Fault zones, deformation studies
DS1995-1814
1995
Spray, J.G.Spray, J.G., Thompson, L.M.Friction melt distribution in a multi ring impact basinNature, Vol. 373, No. 6510, Jan. 12, p. 130-131GlobalCraters, Basins
DS1997-1094
1997
Spray, J.G.Spray, J.G.SuperfaultsGeology, Vol. 25, No. 7, July pp. 579-582GlobalCrater Collapse, Cauldera, ring faults
DS1999-0702
1999
Spray, J.G.Spray, J.G.Shocking rocks by cavitation and bubble implosionGeology, Vol. 27, No. 8, Aug. pp. 695-98.MantleChondrites, ringwoodite
DS1990-1406
1990
Sprenger, A.Sprenger, A., ten Kate, W.G.A graphical software system to present stratigraphic information of surveyed sectionsComputers and Geosciences, Vol. 16, No. 4, pp. 517-538GlobalComputer, Program -graphics stratigraphy
DS1991-1648
1991
Sprenke, K.F.Sprenke, K.F.Gravity modeling with LOTUS 1-23Journal of Geophysical Research, Vol. 17, No. 5, pp. 719-GlobalGravity anomalies
DS1992-1462
1992
Sprenke, K.F.Sprenke, K.F.Analytic geometry formulas and computer routines for stereonet problemsJournal of Geology Education, Vol. 40, pp. 109-115GlobalComputer, Program -stereonet
DS1910-0384
1913
Sprigade, P.Sprigade, P., Lotz, H.Karte des Sperrgebietes in Deutsch-suedwestafrikaBerlin: Dietrich Reimer., 10 MAPSSouthwest Africa, NamibiaDiamond Occurrences, Littoral Diamond Placers
DS1987-0710
1987
Spriggs, A.Spriggs, A., Davies, G.R., Nixon, P.H.Geochemistry of kimberlite source regions: the Gibeon province, NamibiaTerra Cognita, Conference abstracts Oceanic and Continental Lithosphere:, Vol. 7, No. 4, Autumn, abstract only p. 625Namibia, Southwest AfricaBlank
DS1988-0665
1988
Spriggs, A.J.Spriggs, A.J.An isotopic and geochemical study of kimberlites and associated Alkaline rocks from NamibiaPh.d Thesis University of Leeds, 348p. (University of Microfilms, 348pSouthwest Africa, NamibiaKimberlites, Geochemistry
DS1991-0344
1991
Spriggs, A.J.Davies, G.R., Spriggs, A.J., Nixon, P.H., Rex, D.C.A non cognate origin for the Gibeon kimberlite megacryst suiteProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 63-65Southwest Africa, Namibia, South AfricaPetrography, Geochronology -isotope
DS2001-0226
2001
Spriggs, A.J.Davies, G.R., Spriggs, A.J., Nixon, P.H.A non cognate origin for the Gibeon kimberlite megacryst suite, Namibia: implications for the originJournal of Petrology, Vol. 42, No. 1, Jan. pp. 159-72.NamibiaKimberlite - origin, Geochronology - Sr neodymium lead isotopes
DS1860-0393
1882
Spring, W.Spring, W.Les Mines de Diamant de l'afrique Australe (1882)- the Diamond Mines of south Africa.Annual SOC. GEOL. BELG., Vol. 8, PP. 70-73.Africa, South Africa, Cape ProvinceMineralogy
DS1998-1394
1998
Springer, M.Springer, M., Forster, A.Heat flow density across the Central Andean subduction zoneTectonophysics, Vol. 291, No. 1-4, June 15, pp. 123-140.Andes, South AmericaSubduction
DS1991-1649
1991
Springer VerlagSpringer VerlagCycle events in stratigraphySpringer Verlag, 785p. $ approx. $ 60.00GlobalEinsele, G., Ricken, W., Seilacher, A., Stratigraphy -cycle events
DS1990-0688
1990
Springett, M.W.Hester, M.G., Springett, M.W.Geostatistics and kriging: surviving in the real worldAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint, No. 90-92, 10pGlobalGeostatistics, Kriging
DS1985-0640
1985
Springfield, J.T.Springfield, J.T., Mansker, W.L.Factors Affecting Garnet Metamerism and Applications in Kimberlite Evaluation/exploration.Geological Society of America (GSA), Vol. 17, No. 3, P. 193. (abstract.).GlobalGarnet, Population, Mineral Chemistry, Colour
DS1990-0974
1990
Sprininansan, M.Madhaven, V., Rao, J.M., Sprininasan, T.P., Sprininansan, M.The mid-Proterozoic dyke swarm of mica lamprophyres and microshonkinites from Elchuru IndiaMafic dykes and emplacement mechanisms, Editors A.J. Parker, P.C., pp. 363-372IndiaLamprophyric dykes, Shonkinites
DS1990-0974
1990
Sprininasan, T.P.Madhaven, V., Rao, J.M., Sprininasan, T.P., Sprininansan, M.The mid-Proterozoic dyke swarm of mica lamprophyres and microshonkinites from Elchuru IndiaMafic dykes and emplacement mechanisms, Editors A.J. Parker, P.C., pp. 363-372IndiaLamprophyric dykes, Shonkinites
DS200712-1027
2007
Sproule, C.Sproule, C.Trust in trade associations. Crucial role in ensuring ethical business practices and social responsibility.Canadian Diamonds, Spring, pp. 8, 10.CanadaSocial responsibility
DS1990-1498
1990
Sprowl, D.R.Van Schmus, W.R., Martin, M.W., Sprowl, D.R., Geissman, J.Age, neodymium and lead isotopic composition and magnetic polarity for subsurface samples of the 1100 Ma midcontinent riftGeological Society of America (GSA) Annual Meeting, Abstracts, Vol. 22, No. 7, p. A174GlobalGeochronology, Geophysics -magnetics
DS1995-2090
1995
Sprowl, D.R.Xia, Jinghai, Sprowl, D.R.Moho depths in Kansas from gravity inversion assuming exponential densitycontrast.Computers and Geosciences, Vol. 21, No. 2, pp. 237-244.GlobalBasement, Geophysics - gravity
DS1996-1568
1996
Sprowl, D.R.Xia, J., Sprowl, D.R., Steeples, D.W.A model of Precambrian geology of Kansas derived from gravity and magneticdata.Computers and Geosciences, Vol. 22, No. 8, pp. 883-895.KansasGeophysics - magnetics, Precambrian
DS200812-0551
2008
Spurgin, S.Keller, J., Spurgin, S., Weisenberger, T.Tertiary Rhinegraben volcanism: Kaiserstuhl and Hegau.9th. IKC Field Trip Guidebook, CD 38p.Europe, GermanyGuidebook - Volcanics and carbonatite
DS202105-0763
2021
Spurgin, S.Fosu, B.R., Ghosh, P., Weisenberger, T.B., Spurgin, S., Viladar, S.G.A triple oxygen isotope perspective on the origin, evolution, and diagenetic alteration of carbonatites.Geochimica et Cosmochimica Acta, Vol. 299, pp. 52-68. pdfMantlecarbonatites

Abstract: Carbonatites are unique magmatic rocks that are essentially composed of carbonates, and they usually host a diverse suite of minor and accessory minerals. To provide additional insights on their petrogenesis, triple oxygen isotope analyses were carried out on carbonatites from sixteen localities worldwide in order to assess the behaviour of oxygen isotopes (mass-dependent fractionation) during their formation. The study evaluates the mineralogical differences, i.e., calcite, dolomite, ankerite, and Na-carbonates, and the mode of emplacement (intrusive or extrusive) in the mantle-derived carbonatites to further constrain the triple oxygen isotopic composition (??17O) of the upper mantle. ??17O values in the intrusive calcite carbonatites vary between ?0.003 to ?0.088‰ (n?=?20) and ?0.024 to ?0.085‰ (n?=?5) in the dolomite varieties. We surmise that the magnitude of isotopic fractionation in the different carbonate phases during their formation is similar and thus, the observed variations are independent of mineralogy and may be related to alteration in the rocks. Taking the samples that classify as primary igneous carbonatites altogether, the average ??17O value of the mantle is estimated as ?0.047?±?0.027‰ (1SD, n?=?18) which overlaps those of other mantle rocks, minerals and xenoliths, indicating that the mantle has a relatively homogenous oxygen isotope composition. Two ankerite carbonatites have identical ??17O values as calcite but a few samples, together with pyroclastic tuffs have significantly lower ??17O values (?0.108 to ?0.161‰). This deviation from mantle ??17O signature suggests diagenetic alteration (dissolution and recrystallisation) and mixing of carbonate sources (juvenile and secondary carbonates) which is consistent with the high ?18O and clumped isotope (?47) values recorded in the pyroclastic and ankeritic rocks. In summary, diagenetic alteration driven by fluid-rock interaction at low temperatures, sub-solidus re-equilibration with magmatic waters, and the incorporation of secondary carbonates altogether facilitate the alteration of original isotopic compositions of carbonatites, obliterating their primary mantle signatures.
DS1989-0737
1989
Spurr, B.D.Jupp, P.E., Spurr, B.D.Statistical estimation of a shock center: Slate Islands astroblemeMathematical Geology, Vol. 21, No. 2, pp. 191-198Ontario, United StatesGeostatistics
DS201901-0034
2018
Squibb, C.Fulop, A., Kopylova, M., Kurszlaukis, S., Hilchie, L., Ellemers, P., Squibb, C.Petrography of Snap Lake kimberlite dyke ( Northwest Territories, Canada) and its interaction with country rock granitoids.Journal of Petrology, Vol. 59, 12, pp. 2493-2518.Canada, Northwest Territoriesdeposit - Snap Lake

Abstract: Carbonate-rich intrusions in contact with felsic rocks theoretically should show the effects of interaction between the two rock types, due to their contrasting compositions. In reality, though, such interaction is rarely reported at kimberlite contacts. We present the first documented case of lithological and mineralogical zonation at the margin of a kimberlite, the Snap Lake dyke, in contact with the wall-rock granitoid. Our detailed petrographic, mineralogical and geochemical study shows that the fresh hypabyssal kimberlite consists of olivine macrocrysts and microcrysts, and phlogopite macrocrysts set in a groundmass of serpentinized monticellite, phlogopite, spinel, perovskite and apatite, with interstitial lizardite and calcite. This typical Group I kimberlite mineralogy does not match the bulk-rock composition, which resembles a Group II micaceous kimberlite. The mismatch between the chemical and mineralogical properties is ascribed to contamination by granitoid xenoliths and metasomatic reactions with the felsic country rocks, the Snap Lake kimberlite has extremely low bulk-Ca compared to other documented Group I kimberlites. Reaction with deuteric H2O and CO2 has led to Ca removal, serpentinization of olivine, replacement of calcite by dolomite, alteration of perovskite and decomposition of apatite. Adjacent to the contact with the host granitoid and in haloes around granitoid clasts, poikilitic phlogopite and lizardite are replaced by subsolidus phlogopite and a multiphase phyllosilicate composed of phlogopite+?lizardite+?chlorite+?talc. A modified isocon analysis accounts for felsic xenolith assimilation and isolates metasomatic changes. Enrichment of altered kimberlites in Si owes solely to xenolith incorporation. The metasomatic ingress of granitoid-derived Al for a limited distance inside the dyke was counteracted by a flux of Mg and Fe to the granitoid. Metasomatic changes in K and Ca tend to be positive in all lithologies of kimberlite and in the granitoids implying distal transport. The combination of xenolith digestion with metasomatic element transport is expected in hybrid zones where kimberlite magmas interact with felsic wall-rocks.
DS201112-0825
2011
Sracke, A.Prelevic, D., Akal, C., Romer, R.R., Sracke, A., Van den Bogaard, P.Ultrapotassic mafic rocks as geochemical proxies for post collisional dynamics of orogenic lithospheric mantle: the case of southwestern Anatolia, Turkey.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.119-121.Europe, TurkeyLamproite
DS201112-0826
2011
Sracke, A.Prelevic, D., Akal, C., Romer, R.R., Sracke, A., Van den Bogaard, P.Ultrapotassic mafic rocks as geochemical proxies for post collisional dynamics of orogenic lithospheric mantle: the case of southwestern Anatolia, Turkey.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.119-121.Europe, TurkeyLamproite
DS1995-0223
1995
Sraega, D.Bryant, T., Cantin, B., Stweart, R., Sraega, D.Metallic and industrial mineral assessment report for the Pembin a field sampling project.Alberta Geological Survey, MIN 19950016AlbertaExploration - assessment
DS1994-1673
1994
Sraega, D.I.Sraega, D.I.Metallic and industrial mineral assessment report on the Christin a BlockAlberta Geological Survey, MIN 19940003AlbertaExploration - assessment, Takla Star Resources, Fairstar Exploration
DS1994-1674
1994
Sraega, D.I.Sraega, D.I.Metallic and industrial mineral assessment report on the Edmonton blockAlberta Geological Survey, MIN 19940004AlbertaExploration - assessment, Takla Star Resources, Fairstar Exploration
DS1994-1675
1994
Sraega, D.I.Sraega, D.I.Metallic and industrial mineral assessment report on the Ram River BlockAlberta Geological Survey, MIN 19940005AlbertaExploration - assessment, Takla Star Resources, Fairstar Exploration
DS1994-1676
1994
Sraega, D.I.Sraega, D.I.Pincher Block government assessment reportAlberta Geological Survey, MIN 19940006AlbertaExploration - assessment, Takla Star Resources, Fairstar Exploration
DS1994-1677
1994
Sraega, D.I.Sraega, D.I.Legend Block government assessment reportAlberta Geological Survey, MIN 19940007.AlbertaExploration - assessment, Takla Star Resources, Fairstar Exploration
DS201012-0745
2010
Sramek, O.Sramek, O., Ricard, Y., Dubuffet, F.A multiphase model of core formation.Geophysical Journal International, Vol. 181, 1, pp. 198-220.MantleMagmatism
DS201312-0877
2013
Sramek, O.Sramek, O., McDonough, W.F., Kite, E.S., Lekic, V., Dye, S.T., Zhong, S.Geophysical and geochemical constraints on geoneutrino fluxes from Earth's mantle.Earth and Planetary Science Letters, Vol. 361, pp. 356-366.MantleTomography
DS202008-1432
2020
Sramek, O.Patocka, V., Sramek, O., Tosi, N.Minimum heat flow from the core and thermal evolution of the Earth.Physics of the Earth and Planetary Interiors, Vol. 305, 106457, 17p. PdfMantlegeothermometry

Abstract: The role of heat flow coming from the core is often overlooked or underestimated in simple models of Earth's thermal evolution. Throughout most of Earth's history, the mantle must have been extracting from the core at least the amount of heat that is required to operate the geodynamo. In view of recent laboratory measurements and theoretical calculations indicating a higher thermal conductivity of iron than previously thought, the above constraint has important implications for the thermal history of the Earth's mantle. In this work we construct a paramaterized mantle convection model that treats both the top and the core-mantle boundary heat fluxes according to the boundary layer theory, or alternatively employs the model of Labrosse (2015) to compute the thermal evolution of the Earth's core. We show that the core is likely to provide all the missing heat that is necessary in order to avoid the so-called “thermal catastrophe” of the mantle. Moreover, by analyzing the mutual feedback between the core and the mantle, we provide the necessary ingredients for obtaining thermal histories that are consistent with the petrological record and have reasonable initial conditions. These include a sufficiently high viscosity contrast between the lower and upper mantle, whose exact value is sensitive to the activation energy that governs the temperature dependence of the viscosity.
DS2002-1227
2002
Sreeamamurty, A.Patel, M.K., Sreeamamurty, A.Regional search for kimberlite in basal Chhattisgarh formations and surrounding granitic terrain in Saraipalli area, Raipur district, Madhya Pradesh P-II stage.Geological Society of India Records, Vol. 133,6, pp.125-6.India, Madhya PradeshKimberlite
DS201012-0137
2010
Sreenivas, B.Das Sharma, S., Ramesh, D.S., Li, X., Yuan, B., Sreenivas, B., Kind, R.Response of mantle transition zone thickness to plume bouyancy flux.Geophysical Journal International, Vol. 180, 1, pp. 49-58.MantlePlume
DS201903-0525
2019
Sreenivas, B.Kumar, P., Tewari, H.C., Sreenivas, B.Seismic structure of the Central Indian crust and its implications on the crustal evolution.Journal of the Geological Society of India, Vol. 93, 2, pp. 163-170.Indiageophysics - seismic

Abstract: The crustal structures of the Narmada region in Central India bounded by fault system (Narmada- North and South faults : NNF and NSF) has been derived from deep seismic sounding (DSS) studies along the two profiles trending almost north-south direction. The wide-angle phases have been modeled kinematically and dynamically using the 2-D asymptotic ray tracing technique. The combined seismic and gravity modeling reveals a multilayer crust in the region. The crustal wide-angle reflection phases map the Moho discontinuity, where the P-wave velocity jumps from 7.2 km s-1 to 8.0-8.1 km s-1, at depth varying between 38 km and 44 km. A layer with velocity 7.2 km s-1, exists above the Moho in most parts of the profiles and is attributed to the magmatic underplating related to the Deccan volcanism (~65 Ma). The intriguing observation of the study is a zone characterized by anomalous high velocity (6.5-6.6 km s-1) within the upper crust. 2-D gravity modeling demonstrates that this anomalous layer has a density of ~2.9 gm cm-3, which is equivalent to the rocks metamorphosed to granulite/amphibolite facies. This high velocity layer probably represents the granulite enclaves within the Archaean granites/gneiss rocks and was formed during the cratonization of the Achaean crust. Importantly, this high velocity layer shows an average upward displacement of ~8.5 km within the region bounded by NNF and NSF as compared to the regions beyond it. The studies suggest that the observed displacement in the high velocity layer of the upper crust is a result of repeated reactivation of the Narmada fault system.
DS202009-1611
2020
Sreenivas, B.Bhaskar Rao, Y.J., Kumar, T.V., Sreenivas, B., Babu, E.V.S.S.K.A review of Paleo to Neoarchean crustal evolution in the Dharwar craton, southern Indian and the transition towards a plate tectonic regime.Episodes, Vol. 43, 1, pp. 51-68.Indiacraton

Abstract: An emerging view is that Earth’s geodynamic regime witnessed a fundamental transition towards plate tectonics around 3.0 Ga (billion years). However, the manifestations of this change may have been diachronous and craton-specific. Here, we review geological, geophysical and geochronological data (mainly zircon U-Pb age-Hf isotope compositions) from the Dharwar craton representing over a billion year-long geologic history between ~3.5 and 2.5 Ga. The Archean crust comprises an oblique section of ~12 km from middle to deep crust across low- to mediumgrade granitegreenstone terranes, the Western and Eastern Dharwar Cratons (WDC and EDC), and the highgrade Southern Granulite Terrain (SGT). A segment of the WDC preserving Paleo- to Mesoarchean gneisses and greenstones is characterised by ‘dome and keel’ structural pattern related to vertical (sagduction) tectonics. The geology of the regions with dominantly Neoarchean ages bears evidence for convergent (plate) tectonics. The zircon U-Pb age-Hf isotope data constrain two major episodes of juvenile crust accretion involving depleted mantle sources at 3.45 to 3.17 Ga and 2.7 to 2.5 Ga with crustal recycling dominating the intervening period. The Dharwar craton records clear evidence for the operation of modern style plate tectonics since ~2.7 Ga.
DS200712-0393
2007
Sreenivasan, B.Gubbins, D., Willis, A.P., Sreenivasan, B.Correlation of Earth's magnetic field with lower mantle thermal and seismic structure.Physics of the Earth and Planetary Interiors, Vol. 162, 3-4, pp. 256-260.MantleGeophysics - seismics
DS200712-0394
2007
Sreenivasan, B.Gubbins, D., Willis, A.P., Sreenivasan, B.Correlation of Earth's magnetic field with lower mantle thermal and seismic structure.Physics of the Earth and Planetary Interiors, Vol. 162, 3-4, pp. 256-260.MantleGeophysics - seismics
DS200712-1159
2007
Sreenivasan, B.Willis, A.P., Sreenivasan, B., Gubbins, D.Thermal core mantle interaction: exploring regimes for 'locked' dynamo action.Physics of the Earth and Planetary Interiors, Vol. 165, 1-2, pp. 83-92.MantleGeodynamics
DS202012-2248
2020
Sreenivasan, B.Sahoo, S., Sreenivasan, B.Response of Earth's magnetic field to large lower mantle heterogeneity.Earth and Planetary Letters, Vol. 550, 116507, 11p. PdfRussia, Canadageophysics - magnetics

Abstract: A simplified two-fold pattern of convection in the Earth's core is often used to explain the non-axisymmetric magnetic flux concentrations in the present day geomagnetic field. For large lateral variations in the lower mantle heat flux, however, a substantial east-west dichotomy in core convection may be expected. This study examines the effect of a large lateral variation in heat flux at the outer boundary in cylindrical annulus experiments that achieve approximate geostrophy of the convection as well as in rapidly rotating spherical shell simulations. In either geometry, the imposed boundary heat flux is derived from the seismic shear wave velocity in the lowermost mantle. The pattern of large-scale convection in the simulations closely follows that in the annulus experiments, which suggests that the lateral buoyancy at the equator essentially determines the structure of core convection. In particular, the location of a coherent downwelling that forms beneath Canada in mildly driven convection entirely switches over to the Siberian region in strongly driven states. Spherical dynamo models in turn show that this eastward migration of convection causes the relative instability or even the disappearance of the high-latitude magnetic flux in the Western hemisphere. Finally, large radial buoyancy causes homogenization of convection, which may place an upper bound for the Rayleigh number in the core.
DS1975-0864
1978
Srennivasa rao, T.Setti, D.N., Srennivasa rao, T., Sobba raju, M.A Note on the Occurrence of Kimberlite -carbonatite Enclaves in the Peninsular Gneiss Warangal District, A.p.Indian Minerals, Vol. 32, No. 2, PP. 59-61.India, Andhra PradeshAlluvial Placer Deposits, Genesis
DS200812-0936
2008
Sridhar, D.N.Rao, D.V.S., Balaram, V., Raju, K.N., Sridhar, D.N.Paleoproterozoic boninite like rocks in an intracratonic setting from northern Bastar Craton, central India.Journal of the Geological Society of India, Vol. 27, 3, pp. 373-380.IndiaBoninites
DS200812-1137
2008
Sridhar, D.N.Subba Rao, D.V., Sridhar, D.N., Balaram, V., Nagaraju, K., Gnaneshwara Rao, T., Keshavakrishna, A., Singh, U.P.Proterozoic mafic ultramafic dyke swarms in the vicinity of Chhattisgarh Khariar Singhora basins in northern Bastar Craton, central India.Indian Dykes: editors Srivastava, Sivaji, Chalapathi Rao, pp. 377-396.IndiaBoninites
DS2003-0005
2003
Sridhar, M.Ajit, T., Reddy, K., Sridhar, M., Ravi, S., Charavrthi, V., Neelakaran, S.Petrography and geochemistry of the Krishna lamproite field, Andhra PradeshJournal of the Geological Society of India, Vol. 61, 2, Feb., pp. 131-46.India, Andhra PradeshLamproite
DS2003-1148
2003
Sridhar, M.Reddy, T.A.K., Sridhar, M., Ravi, S., Chakravarthi, V., Neelakantam, S.Petrography and geochemistry of the Krishna lamproite field, Andhra PradeshGeological Society of India Journal, Vol. 61, 2, pp. 131-46.India, Andhra PradeshLamproites
DS200412-0010
2003
Sridhar, M.Ajit, T., Reddy, K., Sridhar, M., Ravi, S., Charavrthi, V., Neelakaran, S.Petrography and geochemistry of the Krishna lamproite field, Andhra Pradesh.Journal of the Geological Society of India, Vol. 61, 2, Feb., pp. 131-46.India, Andhra PradeshGeochemistry Lamproite
DS200412-1891
2004
Sridhar, M.Sridhar, M., Chowdhary, V.S., BNayak, S.S., Augustine, P.F.Discovery of kimberlite pipes in Gadwal area, Mahbubnagar District, Andhra Pradesh.Journal of Geological Society of India, Vol. 63, 1, pp. 95-99.India, Andhra PradeshKimberlite
DS200612-0250
2005
Sridhar, M.Chowdary, V.S., Rau, T.K., Bhaskara Rao, K.S., Sridhar, M., Sinha, K.K.Discovery of a new kimberlite cluster - Timmasamudram kimberlite cluster, Wajrakarus kimberlite field, Anantapur district, Andhra Pradesh.Geological Society of India, Bangalore November Meeting Group Discussion on Kimberlites and Related Rocks India, Abstract p. 39-41.India, Andhra Pradesh, Dharwar CratonKimberlite - Timmasamudran
DS200612-0970
2005
Sridhar, M.Nayak, S.S., Ravi, S., Sridhar, M., Reddy, N.S., Chowdary, V.S., Bhaskara Rao, K.S., Sinha, K.K., Rao, T.K.Geology and tectonic setting of kimberlites of Dharwar Craton.Geological Society of India, Bangalore November Meeting Group Discussion on Kimberlites and Related Rocks India, Abstract p. 36-38.India, Andhra Pradesh, Dharwar CratonTectonics
DS200612-1135
2005
Sridhar, M.Rau, T.K., Reddy, N.S., Ravi, S., Sridhar, M., Chowdary, V.S., Bhaskara Rao, K.S.Primary source rocks for diamonds in Banaganapalle conglomerate ( Kurnool Group) - a critical appraisal.Geological Society of India, Bangalore November Meeting Group Discussion on Kimberlites and Related Rocks India, Abstract p. 77-79.India, Andhra Pradesh, Dharwar CratonConglomerate - Banaganapalle
DS200612-1351
2005
Sridhar, M.Sridhar, M., Rau, T.K.Discovery of a new lamproite field - Ramadugu lamproite field (RLF) Nalgonda district, Andhra Pradesh.Geological Society of India, Bangalore November Meeting Group Discussion on Kimberlites and Related Rocks India, Abstract p. 55-57.India, Andhra Pradesh, Dharwar CratonLamproite - Ramadugu
DS200812-0199
2008
Sridhar, M.Chalapathi Rao, N.V., Dongre, A., Kamde, G., Srivisastra, R.K., Sridhar, M., Kaminisky, F.V.Petrology, geochemistry and genesis of new Mesoproterozoic high magnesian calcite rich kimberlites of Siddanpalli, eastern Dharwar Craton...products9IKC.com, 3p. extended abstractIndiaSubduction related magmatic sources?
DS200912-0104
2009
Sridhar, M.Chalapathi Rao, N.V., Dongre, A., Kamde, G., Srivastava, R.K., Sridhar, M., Kaminsky, F.V.Petrology, geochemistry and genesis of newly discovered Mesoproterozoic highly magnesian, calcite rich kimberlites from Siddanpalli, Eastern Dharwar CratonMineralogy and Petrology, Online availableIndiaProducts of subduction-related magmatic sources?
DS201012-0098
2010
Sridhar, M.Chalapathi Rao, N.V., Dongre, A., Kamde, G., Srivastava, R.K., Sridhar, M., Kaminisky, F.V.Petrology, geochemistry and genesis of newly discovered Mesoproterozoic highly magnesian, calcite rich kimberlites from Siddanpalli, eastern Dharwar Craton...Mineralogy and Petrology, Vol. 98, 1-4, pp. 313-328.IndiaSubduction related magmatic sources?
DS201212-0580
2012
Sridhar, M.Ravi, S., Sufija, M.V., Patel, S.C., Gupta, T., Sridhar, M., Kaminsky, F.V., Khachatryan, G.K., Netravali, S.V.Diamonds from the eastern Dharwar craton, India: their physical and infrared characteristics.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractIndiaDiamond morphology
DS201312-0520
2013
Sridhar, M.Kumar, A., Ahmed, S., Priya, R., Sridhar, M.Discovery of lamproites near Vattikod area, nw margin of the Cuddapah basin, eastern Dharwar craton, southern India.Journal of the Geological Society of India, Vol. 82, 4, pp. 307-312.IndiaLamproite
DS200712-0866
2007
SridherRajendra Prasad, B., Kesava Rao, G., Mall, D.M., Koteswarar Rao, P., Raju, S., Reddy, SridherTectonic implications of seismic reflectivity pattern observed over the Precambrian southern granulite terrain, India.Precambrian Research, Vol. 153, 1-2, pp. 1-10.IndiaGeophysics - seismics
DS201806-1242
2018
Srijayanthi, G.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
Srijayanthi, G.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.
DS200612-1352
2005
Srikantappa, C.Srikantappa, C., Fareeduddin, Malathi, M.N.Olivine hosted melt inclusions and serpentine hosted aqueous fluids in diamond bearing kimberlites from Wajakarur, Andhra Pradesh, India.Geological Society of India, Bangalore November Meeting Group Discussion on Kimberlites and Related Rocks India, Abstract p. 75-76.India, Andhra Pradesh, Dharwar CratonDiamond inclusions
DS1993-1423
1993
Srimal, N.Sen, G., Macfarlane, A., Srimal, N.Mantle metasomesGeological Society of America Annual Abstract Volume, Vol. 25, No. 6, p. A99 abstract onlyHawaiiMantle, Metasomatism
DS2003-0522
2003
Srinagesh, D.Gupta, S., Rai, S.S., Prakasam, K.S., Srinagesh, D., Basal, B.K., Chadha, R.K.The nature of the crust in southern India: implications for Precambrian crustal evolutionGeophysical Research Letters, Vol. 30, 8, 10.1029/2002GLO16770IndiaTectonics
DS200412-0750
2003
Srinagesh, D.Gupta, S., Rai, S.S., Prakasam, K.S., Srinagesh, D., Basal, B.K., Chadha, R.K., Priestly, K., Gaur, V.K.The nature of the crust in southern India: implications for Precambrian crustal evolution.Geophysical Research Letters, Vol. 30, 8, 10.1029/2002 GLO16770IndiaTectonics
DS201312-0733
2013
Srinagesh, D.Ravi Kumar, M., Saikia, D., Singh, A., Srinagesh, D., Baidya, P.R., Dattatrayam, R.S.Low shear velocities in the sublithospheric mantle beneath the Indian shield?Journal of Geophysical Research, 50114IndiaTectonics
DS201412-0833
2014
Srinagesh, D.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
DS202106-0943
2021
Srinagesh, D.Illa, B., Reshma, K.S., Kumar, P., Srinagesh, D., Haldar, C., Kumar, S., Mandal, P.Pn tomography and anisotropic study of the Indian Shield and the adjacent regions.Tectonophysics, Vo. 813, 228932 23p. PdfIndiatomography

Abstract: High-resolution P-wave velocity and anisotropy structure of the hitherto elusive uppermost mantle beneath the Indian shield and its surrounding regions are presented to unravel the tectonic imprints in the lithosphere. We inverted high quality 19,500 regional Pn phases from 172 seismological stations for 4780 earthquakes at a distance range of 2° to 15° with a mean apparent Pn velocity of 8.22 km/s. The results suggest that the Pn velocity anomalies with fast anisotropic directions are consistent with the collision environments in the Himalaya, Tibetan Plateau, Tarim Basin, and Burmese arc regions. The higher Pn anomalies along the Himalayan arc explicate the subducting cold Indian lithosphere. The cratonic upper mantle of the Indian shield is characterized by Pn velocity of 8.12-8.42 km/s, while the large part of the central Indian shield has higher mantle-lid velocity of ~8.42 km/s with dominant anisotropic value of 0.2-0.3 km/s (~7.5%) suggesting the presence of mafic ‘lava pillow’ related to the Deccan volcanism. The impressions of the rifts and the mobile belts are conspicuous in the velocity anomaly image indicating their deep seated origin. The Pn anisotropy in the Indian shield exhibits a complex pattern and deviates from the absolute plate motion directions derived from the SKS study, demonstrating the presence of frozen anisotropy in the Indian lithospheric uppermost mantle, due to the large scale tectonic deformation after its breakup from the Gondwanaland. Whereas, Pn and SKS anisotropic observations are well consistent in Tarim basin, Tibetan regions, eastern Himalayan syntaxis and the Burmese arc. The modeled anisotropic Pn clearly manifests a lower velocity anomaly bounded by 85°E and 90°E ridges in the southern Bay of Bengal. Further, 85°E ridge spatially separates the BoB lithosphere into faster and slower regions consistent with the body wave tomography and free-air gravity observation.
DS1989-1442
1989
Sringesh, D.Sringesh, D., Rai, S.S., Ramesh, D.S., Gaur, V.K., Rao, C.V.R.Evidence for thick continental roots beneath South Indian shieldGeophysical Research Letters, Vol. 16, No. 9, September pp. 1055-1058IndiaMantle
DS2003-0523
2003
Sringesh, D.Gupta, S., Rai, S.S., Prakasam, K.S., Sringesh, D., Chadha, R.K., Priestly, K.First evidence for anomalous thick crust beneath mid Archean western Dharwar cratonCurrent Science, Vol. 84, 9, pp. 1219-26.IndiaCraton
DS200412-0751
2003
Sringesh, D.Gupta, S., Rai, S.S., Prakasam, K.S., Sringesh, D., Chadha, R.K., Priestly, K., Gaur, V.K.First evidence for anomalous thick crust beneath mid Archean western Dharwar craton.Current Science, Vol. 84, 9, pp. 1219-26.IndiaCraton
DS1992-0902
1992
Srinivansan, R.Kumar, A., Srinivansan, R., Gopalan, K., Patil, D.J.A reappraisal of an Archean carbonatite of Nellor schist belt, SouthIndiaJournal Geological Society of India, Vol. 40, August pp. 169-174IndiaCarbonatite, Geochemistry
DS1998-0916
1998
Srinivas, M.Madhaven, V., David, K., Srinivas, M.Comparative study of lamprophyres from the Cuddapah Intrusive province(CIP) Andhra Pradesh, India.Journal of Geological Society India, Vol. 52, No. 6, Dec. pp. 621-42.India, South IndiaLamprophyres, Deposit - Elchuru, Purimetla, PrakasaM.
DS1999-0435
1999
Srinivas, M.Madhaven, V., Rao, J.M., Srinivas, M.Mid Proterozoic intraplate alkaline magmatism in the eastern Dharwar Craton of India: the Cuddapah ProvinceJournal of Geological Society IndiaM., Vol. 53, No. 2, Feb. 1, pp. 143-62.India, CuddapahAlkaline rocks, Magmatism, Craton
DS200412-1892
2004
Srinivas, M.Srinivas, M.Signatures of Mesoproterozoic alkaline magmatic province from Andhra Pradesh, southern Peninsula India.Geochimica et Cosmochimica Acta, 13th Goldschmidt Conference held Copenhagen Denmark, Vol. 68, 11 Supp. July, ABSTRACT p.A593.India, Andhra PradeshKimberlites, lamproites
DS200712-1028
2007
Srinivas, M.Srinivas, M., Reddy, A.G.S.The Podili alkaline complex, Prakasam alkaline province, Andhra Pradesh, southern India.Plates, Plumes, and Paradigms, 1p. abstract p. A963.India, Andhra PradeshAlkalic
DS201612-2286
2016
Srinivas, M.Chandra Phani, P.R., Srinivas, M.Regolith geochemical studies in kimberlitic terrain: a case study from Lattavaram kimberlite cluster, eastern Dharwar Craton, southern India.Acta Geologica Sinica, Vol. 90, July abstract p. 191.IndiaDeposit - Lattavaram

Abstract: Utility of geochemistry in mineral exploration is known since more than half-a-century. In reconnaissance diamond exploration, regolith geochemistry is a well known tool worldwide and helps in distinguishing bedrock geology in hard rock terrains. More than 100 kimberlite pipes were discovered so far in the Eastern Dharwar Craton (EDC) of South India by various public and private organizations. Within the EDC, majority of diamondiferous pipe clusters occur in Anantapur District of Andhra Pradesh state in India. Lattavaram kimberlite cluster (LKC) is one among them in this district and four pipes in this cluster are reported to be diamondiferous along with two kimberlite bodies at Muligiripalli. The kimberlite pipes at Lattavaram occur in semi-circular shape whereas a kimberlite body exposed at Muligiripalli village occurs as a dyke within the granitoid country. The pipe 4 at Lattavaram exhibits conspicuous difference in the soil color and texture i.e., greenish color and mottled texture when compared with the reddish brown compact residual soils of granitic country rock. In the Indian context, soil regolith geochemistry is not a popular subject in search of kimberlites. It is observed that little or no literature is available on the utility of regolith geochemistry applied to kimberlite or diamond exploration in India. An attempt is made in this study, to demonstrate and understand the spatial surface geochemical signatures using residual soil geochemistry on known kimberlite pipes viz., 3 and 4 of LKC. Spatial and statistical analysis of trace and rare earth elements revealed that certain elements show predominance in the vicinity of the kimberlite pipes which can act as an exploration guide in distinguishing kimberlitic rocks within a granitoid country. These elements show distinct variation in their dispersion in the soil which can be attributed to basement lithology. It is observed that elements like Cr, Ni, Co, Cu, Nb, Zr, Ti, Ba and rare earth elements (REE) are significantly enriched in the mottled zone and calcretized duricrust relative to the country rock granitoids. A suite of trace elements comprising those associated with ultramafic rocks (Cr, Co & Ni) and felsic rocks (Nb, La, Sm and P) can readily distinguish the ultramafic/kimberlitic regolith from that derived from granitoid or felsic rocks which can be used as an exploration path finder.
DS201705-0816
2017
Srinivas, M.Chandra Phani, R., Srinivas, M.Geochemistry of some calcretes in Nalgonda district: implications for target selection in kimberlite/lamproite exploration.National Seminar on Strategic trends and future perspectives in the development of natural resources of Telangana state, Kakatiya University, Abstract Volume, 1, March 30,31 pp. 18-19.India, TelanganaLamproites

Abstract: The authigenic carbonates which occur in arid and semi-arid regions of the world are commonly referred to as calcretes or caliche or kankar. These are pedogenic calcretes which occur in association with soil forming the residual regolith. Many rock types produce calcretes upon weathering and denudation, but calcrete derived from certain rocks acts as an exploration guide. Calcrete is a prominent sampling medium in countries like Australia and South Africa whereas it is not so popular in the Indian context. Kimberlites, being ultrapotassic in nature and owing to the enrichment of olivine, serpentine an calcite, often produce calcrete duricrust as a capping on the outcrops. The calcretes derived from kimberlites contain relict kimberlitic xenocrystic minerals like pyrope, ilmenite, Cr-diopside, pseudomorphs of olivine, phlogopite etc. unlike those derived from other rock types. The calcretes derived from granitoid rocks significantly contain minerals like chert, quartz, semi-weathered feldspar etc. Recently more than fifteen lamproites have been discovered at Vattikodu and Chintalapalli and one lamprophyre at Bayyaram of Telangana state, by the Geological Survey of India, unraveling new panorama that the state has a substantial potential for occurrence of more kimberlite clan rocks. Perhaps for the first time, an attempt has been made here to test the geochemical affinity of calcretes from various locations within Nalgonda district, which is endowed mostly with granitic terrain and Cuddapah sedeimentaries in the southern part. About sixteen samples have been collected from the in-situ regolith, spread in the granite-mafic dyke terrain, with an omission of calcretes occurring in transported black soil areas. The samples were geochemically analysed for major and trace elements for a preliminary study. The data has been compared with published geochemical data of lamproites of Ramadugu Field, to understand their geohchemical association. The calcretes are low in SiO2 (33.92-45.1wt %), high in K2O (1.07-2.21wt %) and CaO (0.78-13.61wt %). When compared to other major elements, MgO displays low concentration and K2O has a higher concentration than Na2O. The trace elements are found to be enriched in some of the samples collected in close vicinity of known lamproite occurrences. The samples show a high degree of chemical weathering, alteration and compositional variation indices. It is observed that enrichment of elements like Cr, Nb, Ni indicates, similar to parent kimberlite/lamproite rock, favourable targets for further ground exploration in virgin areas. In the present study, two samples, towards five kilometers southeast of Vattikodu Lamproite Field, possess higher Nb (>25ppm) concentration, which stand out as explorable targets for further ground investigations. Further field investigations such as geological mapping, pitting, petrography and geochemistry on these two locations are in progress to ascertain whether or not these two targets unveil new kimberlites/lamproites in the area.
DS201712-2719
2017
Srinivas, M.Phani, P.R.C., Srinivas, M.Quantitative study of indicator minerals on kimberlite pipe-5 at Muligiripalli, Wajrakarur field, southern India. Preliminary results of loam sampling.Russian Mineralogical Society 200th. Anniversary meeting Oct. 10-13., 4p. Abstract pdfIndiadeposit - Pipe-5, Wajrakakarur

Abstract: In an attempt to study the kimberlite indicator minerals (KIMs), loam sampling in the close vicinity of the pipes has been carried out on some kimberlites of the WKF. In this paper, preliminary results of KIMs derived out of loam sampling on one of the WKF pipes at Muligiripalli (pipe-5) are presented. Surface loam sampling has been carried out in the topographically low-lying areas in the close proximity of the pipe outcrop. Four composite samples, at a spacing of ~100 meters, weighing 25 kg each have been collected and sieved through 1 mm mesh. Approximately 5 kg of ‘-1’ fraction has been obtained after sieving which is further subjected to coning and quartering. The material has been subjected to heavy mineral (HM) separation using a manual jig. The HM further screened through Frantz’s isodynamic separator to separate magnetic mineral grains. The HM assemblage includes ilmenite, chromite, Cr-diopside, olivine and sphene. ). To ascertain the kimberlitic nature of the HM grains and thereby to check diamondiferous nature of this pipe, additonal loam sampling to obtain more number of mineral grains to carry out Electron Microprobe Analysis (EPMA) is planned.
DS201805-0971
2018
Srinivas, M.Phani, R., Raju, V.V., Srinivas, M.Petrological and geochemical characteristics of a shoshonitic lamprophyre, Sivarampet, Wajrakarur, kimberlite field, southern India.Journal of Applied Geology and Geophysics (IOSR), Vol. 6, 2, pp. 55-69. pdfIndiashoshonite

Abstract: Field geological, petrographic and geochemical characteristics of a lamprophyre intrusion, presumably of plug-type, at Sivarampet (SPL), occurring within the Wajrakarur kimberlite field (WKF) to the west of Cuddapah basin, are presented and discussed. The lamprophyre intrusion occurs as brecciated outcrop with angular country rock granitoid clasts and also it forms stringers/veinlets within the granitic country rock. The melanocratic rock displays panidiomorphic/porphyritic texture, typical of lamprophyres, comprising clinopyroxene, biotite, phlogopite set in a groundmass of feldspar, magnetite and spinel. Plagioclase is dominant feldspar. The K2O/Na2O ratio ranges from 1.55 to 1.89 wt %, making it distinctly potassic and brings out its shoshonitic behaviour. The fractionated chondrite normalised patterns of REE (with average (La/Yb)N= 21.01 ppm) implies involvement of an enriched mantle source while depleted values of Nb, Hf, Th and U concentrations indicate prevalence of subducted component in the mantle source. The concentrations of Rb, Sr and Ba indicate presence of phlogopite in the source. Based on the mineral assemblages, the SPL can be classified as calc-alkaline variety; however, its geochemistry shows characteristics of both alkaline and calc-alkaline varieties. The moderate Mg# (52 to 55.6) and low concentration of Ni (95.61 to 112.4 ppm) in the bulk rock indicate a low degree of partial melting of magmatic fluid from enriched asthenospheric mantle which underwent fractionation of olivine and pyroxene, subsequently producing lamprophyre magma. Recent discovery of diamonds in shoshonitic lamprophyres of Canada, appeals further investigations on diamondiferous nature of similar rock types of the WKF.
DS201809-2076
2018
Srinivas, M.Phani, P.R., Srinivas, M.Petrogenesis and diamond prospectivity of kimberlites of Anumpalli cluster, Wajrakarur field, southern India.Goldschmidt Conference, 1p. AbstractIndiadeposit - Anumpalli

Abstract: The Wajrakarur kimberlite field (WKF) records >45 pipes so far, majority being diamodiferous. In addition to pipe-10 (Anumpalli) and 11 (Dibbasanipalli) discovered by the Geological Survey of India, of late, Rio Tinto Group has discovered three more outcropping pipes in this area (east of Dibbasanipalli, west of Anumpalli and Khaderpet) and termed all these five pipes as Anumpalli kimberltie cluster (AKC). The AKC pipes contain crustal granitoid xenoliths. The Khaderpet and Dibbasanipalli east pipes show effects of fenitisation in the country rock granitoids and are intensely chloritised kimberlite granite breccias; however, the former is unique in having its association with carbonatite (sovite) intrusion. Petrographically, the AKC kimberlites exhibit inequigranular texture resulted by anhedral to subhedral olivine macrocrysts and pseudomorphs, phenocrysts of Crdiopside, ilmenite, perovskite and minor or no amounts of phologopite with two generations of olivine within a finegrained matrix of same mineral phases. Based on the major element geochemistry the AKC pipes are classified as Group- I archetypal. Based on trace element modeling, the AKC pipes appear to be originated form garnet lherzolite source with residual garnet of 0.5 to 5%, associated with stable continental and/or orogenic area and remarkably belong to non-subduction environment. The observed LREE enrichment and low HREE cencentrations in the AKC, is consistent with inferior degrees of partial melting (0.1 to 2%). The AKC pipes appear to have originated from a hydrous magma enriched in volatiles. Exploration evidences support that kimberlites of the AKC are diamodiferous. The calculated diamond grade (DG) values of the AKC pipes are high (3.43 to 8.48) which are inversely proportional to the TiO2 content. In the binary diagram of Ta and Sc (ppm), the AKC pipes plot in the field of ‘Fe-Ti diamondiferous kimberlites’. In the Fe2O3 (wt %) vs. Y (ppm) diagram, the AKC pipes plot in the ‘prospective’ field. The diamondiferous nature of the AKC pipes indicates the conditions of diamond preservation at metastable phases in crustal environment during rapid ascent of kimberlite melt to the surface from the deep mantle, which is supported by low density and ultralow viscosity of these intrusions.
DS201902-0307
2019
Srinivas, M.Phani, P.R.C., Srinivas, M.Context for diamond exploration in Telangana state through a holistic petrological appraisal of kimberlite clan rocks ( KCR).Earth, Ocean, Atmospheric & Environmental Sciences, 1p. Abstract EOAES-0-14Indiacraton

Abstract: The abstracts broadly summarises petrological aspects of kimberlite clan rocks so far discovered in the Telangana state in light of recent finds emphasising the context for diamond exploration in the state. This was presented in the '1st Telangana Science Congress (TSSC)-2018' organised by the Telangana Academy of Science, Hyderabad and National institute of Technology, Warangal (22-24, December, 2018).
DS201905-1077
2018
Srinivas, M.Soderlund, U., Bleeker, W., Demirer, K., Srivastava, R.K., Hamilton, M., Nilsson, M., Personen, L.J., Samal, A.K., Jayananda, M., Ernst, R.E., Srinivas, M.Emplacement ages of Paleoproterozoic mafic dyke swarms in eastern Dharwar craton, India: implications for paleoreconstructions and support for a ~30 degree change in dyke trends from south to north.Precambrian Research, doi.org/10.1016/ j.precamres.2018.12.017Indiacraton

Abstract: Large igneous provinces (LIPs) and especially their dyke swarms are pivotal to reconstruction of ancient supercontinents. The Dharwar craton of southern Peninsular India represents a substantial portion of Archean crust and has been considered to be a principal constituent of Superia, Sclavia, Nuna/Columbia and Rodinia supercontinents. The craton is intruded by numerous regional-scale mafic dyke swarms of which only a few have robustly constrained emplacement ages. Through this study, the LIP record of the Dharwar craton has been improved by U-Pb geochronology of 18 dykes, which together comprise seven generations of Paleoproterozoic dyke swarms with emplacement ages within the 2.37-1.79 Ga age interval. From oldest to youngest, the new ages (integrated with U-Pb ages previously reported for the Hampi swarm) define the following eight swarms with their currently recommended names: NE-SW to ESE-WNW trending ca. 2.37 Ga Bangalore-Karimnagar swarm. N-S to NNE-SSW trending ca. 2.25 Ga Ippaguda-Dhiburahalli swarm. N-S to NNW-SSE trending ca. 2.22 Ga Kandlamadugu swarm. NW-SE to WNW-ESE trending ca. 2.21 Ga Anantapur-Kunigal swarm. NW-SE to WNW-ESE trending ca. 2.18 Ga Mahbubnagar-Dandeli swarm. N-S, NW-SE, and ENE-WSW trending ca. 2.08 Ga Devarabanda swarm. E-W trending 1.88-1.89 Ga Hampi swarm. NW-SE ca. 1.79 Ga Pebbair swarm. Comparison of the arcuate trends of some swarms along with an apparent oroclinal bend of ancient geological features, such as regional Dharwar greenstone belts and the late Archean (ca. 2.5 Ga) Closepet Granite batholith, have led to the hypothesis that the northern Dharwar block has rotated relative to the southern block. By restoring a 30° counter clockwise rotation of the northern Dharwar block relative to the southern block, we show that pre-2.08 Ga arcuate and fanning dyke swarms consistently become approximately linear. Two possible tectonic models for this apparent bending, and concomitant dyke rotations, are discussed. Regardless of which deformation mechanisms applies, these findings reinforce previous suggestions that the radial patterns of the giant ca. 2.37 Ga Bangalore-Karimnagar dyke swarm, and probably also the ca. 2.21 Ga Anantapur-Kunigal swarm, may not be primary features.
DS201907-1568
2018
Srinivas, M.Phani, R., Srinivas, M.The calcrete geochemistry in identifying kimberlite lamproite exploration targets - a case study from Nalgonda district, Telangana, southern India.International Journal of Trend in Scientific Research and Development, Vol. 2, 2, pp. 964-975. pdfIndialamproite

Abstract: The pedogenic carbonates, found mainly in arid and semi-arid regions of the world, are commonly referred to as calcretes or caliche or kankar authigenic carbonate products which occur in association with soil, forming the residual regolith. Many rock types can produce calcretes upon weathering and denudation, but calcrete derived from certain rocks like kimberlite/lamproite acts as an exploration guide. Calcrete is a prominent sampling medium in diamond-rich countries like Australia and South Africa whereas it has not received popularity in the Indian context. Kimberlites being ultrapotassic in nature and owing to the enrichment of olivine and serpentine often produce calcrete duricrust as a capping. Recently more than twenty lamproites have been discovered in the Telangana state by the Geological Survey of India. These occurrences unravel a new panorama that the state has a substantial potential for occurrence of more kimberlite/lamproite clan rocks. An attempt has been made here to test the geochemical affinity of calcretes from various locations within Nalgonda district. The geochemical data of calcrete samples of this study has been compared with published geochemical data of lamproites of Ramadugu Field, to understand their geochemical association to kimberlite/lamproite. The calcretes are low in SiO2 (33.92-45.1 wt %), high in K2O (1.07-2.21 wt %) and CaO (0.78 When compared to other major elements, MgO displays low concentration. The trace elements are found to be enriched in some of the samples collected in close vicinity of known lamproite occurrences. The samples show high degree of chemic alteration and compositional variation indices. It is observed that enrichment of elements like Cr, Nb, Ba, Ti, Zr etc. indicates, similar to parent kimberlite/lamproite rock, favourable targets for further ground exploration in virgin areas present study, two samples, towards five kilometers northeast of Vattikodu Lamproite Field, possess higher concentrations of Nb (>25ppm), Ba (>400 ppm), Zr (>650 ppm) and Ti (>3500 ppm) which stand out as plausible explorable targets for further ground investigations. Further investigations on these two locations are suggested to ascertain whether or not these two targets unveil new kimberlites/lamproite occurrences in the area.
DS201907-1569
2019
Srinivas, M.Phani, R., Srinivas, M.Role of calcrete petrography in reconnaissance kimberlite exploration - some evidence from Wajkakarur field, Anantapur district, Andhra Pradesh.Science Spectrum, Vol. 3, 3-4, pp. 44-56. pdfIndiadeposit - Wajrakarur
DS200412-1893
2004
Srinivas, S.Srinivas, S.Basinal and structural appraisal of magnetic dat a of Chattisgarh region, central India.Journal Geological Society of India, Vol. 63, 3, pp. 323-335.IndiaGeophysics - magnetics, structure
DS201412-0487
2014
Srinivasa Sarma, D.Kumar, A., Nagaraju, E., Srinivasa Sarma, D., Davis, D.W.Precise baddeleyite geochronology by the thermal extraction thermal ionization mass spectrometry method.Chemical Geology, Vol. 371, pp. 72-79.Africa, South AfricaDeposit - Palabora carbonatite
DS1990-1407
1990
Srinivasan, A.Srinivasan, A., Richards, J.A.Knowledge based techniques for multi-source classificationInternational Journal of Remote Sensing, Vol. 11, No. 3, March, pp. 505-542GlobalRemote sensing, GIS, Computer systems
DS200412-1894
2004
Srinivasan, A.Srinivasan, A., Top,Z., Sclosser, P., Hohmann, R., Iskandarani, M., Olson, D.B., Lupton, J.E., Jenkins, W.J.Mantle 3 He distribution and deep circulation in the Indian Ocean.Journal of Geophysical Research, Vol. 109, 6, 10.1029/2003 JC002028Indian OceanMineralogy
DS201810-2380
2018
Srinivasan, A.Srinivasan, A.What termites can teach us. Roboticists are fascinated by their 'swarm intelligence', biologists by their ability to turn grass into energy. But can humans replicate their achievements?TheNewYorker.com, Sept. 17, 10p. Globaltermites
DS2001-0787
2001
Srinivasan, P.Mohanty, S.N., Srinivasan, P.Regional survey to identify potential blocks for occurrence of kimberlite/lamproite pipesRecords of the Geological Survey of India, Vol. 132, 3, eastern 1997-1998, pp.209-11.India, OrissaGeochemistry
DS2002-1071
2002
Srinivasan, P.Mohanty, S.N., Srinivasan, P.Regional survey to identify potential blocks for occurrence of kimberlite/lamproite pipes in Indravati River Basin, Koraput and Nabarangapur Districts, OrissaRecords of the Geological Survey of India, Vol. 133, 3, eastern 1998-1999, pp.191-3.India, OrissaGeochemistry
DS200412-1347
2001
Srinivasan, P.Mohanty, S.N., Srinivasan, P.Regional survey to identify potential blocks for occurrence of kimberlite/lamproite pipes in Indravati Basin, Koraput and Nawarangpur district, Orissa.Records of the Geological Survey of India, Vol. 132, 3, eastern 1997-1998, pp.209-11.India, OrissaGeochemistry
DS200412-1348
2002
Srinivasan, P.Mohanty, S.N., Srinivasan, P.Regional survey to identify potential blocks for occurrence of kimberlite/lamproite pipes in Indravati River Basin, Koraput andRecords of the Geological Survey of India, Vol. 133, 3, eastern 1998-1999, pp.191-3.India, OrissaGeochemistry
DS200612-0942
2001
Srinivasan, P.Mohanty, S.N., Srinivasan, P.Regional exploration scenario and primary diamond source rock targeting in Ib, Tel and Indravati river basins of Orissa.National Seminar on Exploration Survey, Geological Society of India Special Publication, No. 58, pp. 623-627.India, OrissaDiamond exploration
DS1992-0903
1992
Srinivasan, R.Kumar, A., Srinivasan, R., Gopalan, K., Patil, D.J.A reappraisal of an Archean carbonatite of Neollore schist belt, KarnatakaJournal of Geological Society India, Vol. 40, No. 2, August pp. 169-175IndiaCarbonatite
DS1999-0533
1999
Srinivasan, R.Parthasarathy, G., Srinivasan, R., Vairamani et al.Occurrence of natural fullerenes in low grade metamorphosed Proterozoic shungite from Karelia, RussiaGeochimica et Cosmochimica Acta, Vol. 62, No. 21-22, Nov. pp, 3541-44.RussiaFullerenes, Carbon - shales
DS2003-1138
2003
Srinivasan, R.Ray, L., Kumar, P.S., Reddy, G.K., Roy, S., Rao, G.V., Srinivasan, R., RaoHigh mantle heat flow in a Precambrian granite province: evidence from southern IndiaJournal of Geophysical Research, Vol. 108, B2, 10.1029/2001JB000688IndiaUHP
DS2003-1139
2003
Srinivasan, R.Ray, L., Kumar, P.S., Reddy, G.K., Roy, S., Rao, G.V., Srinivasan, R., RaoHigh mantle heat flow in a Precambrian granulite province: evidence from southernJournal of Geophysical Research, Vol. 108, 2, ETG 6IndiaUHP, Geothermometry
DS200412-1637
2003
Srinivasan, R.Ray, L., Kumar, P.S., Reddy, G.K., Roy, S., Rao, G.V., Srinivasan, R., Rao, R.U.M.High mantle heat flow in a Precambrian granulite province: evidence from southern India.Journal of Geophysical Research, Vol. 108, 2, ETG 6IndiaUHP Geothermometry
DS200612-1353
2001
Srinivasan, R.Srinivasan, R., Chandrasekaran, V.Search for kimberlites/lamproites in the Krishnagiri terrain of northern part of Tamil Nadu and future strategies.National Seminar on Exploration Survey, Geological Society of India Special Publication, No. 58, pp. 647-649.India, Tamil NaduDiamond exploration
DS201808-1785
2018
Srinivasan, S.Rose, B.C. ,Huang, D., Zhang, Z-H., Stevenson, P., Tyryshkin, A.M., Sangtawesin, S., Srinivasan, S., Loudin, L., Markham, M.L., Edmonds, A.M., Twitchen, D.J., Lyon, S.A., de Leon, N.P.Observation of an environmentally insensitive solid-state spin defect in diamond.Science , Vol. 361, July 6, p. 60-63.Technologysynthetic

Abstract: Engineering coherent systems is a central goal of quantum science. Color centers in diamond are a promising approach, with the potential to combine the coherence of atoms with the scalability of a solid-state platform. We report a color center that shows insensitivity to environmental decoherence caused by phonons and electric field noise: the neutral charge state of silicon vacancy (SiV0). Through careful materials engineering, we achieved >80% conversion of implanted silicon to SiV0. SiV0 exhibits spin-lattice relaxation times approaching 1 minute and coherence times approaching 1 second. Its optical properties are very favorable, with ~90% of its emission into the zero-phonon line and near -transform-limited optical linewidths. These combined properties make SiV0 a promising defect for quantum network applications.
DS1989-0873
1989
Srinivasan, T.P.Leelanandam, C., Srinivasan, T.P., Ratnakar, J.The sub-alkaline and alkaline rocks of the Settupallecomplex, Prakasamdistrict, Andhra Pradesh IndiaGeological Society of India, Memoir, Editor C. LeelanandaM., No. 15, pp. 241-265IndiaAlkaline rocks, Fayalite
DS1994-1678
1994
Srinivason, R.Srinivason, R., et al.Middle -late Archean geology of eastern Baltic shields, note on similarity and contrast with Archean s. India.Proceedings Indian Acad. Sciences, Vol. 102, No. 4, Dec. pp. 567-587.India, Baltic shieldArchean geology
DS2002-1302
2002
SrinivasuluRamadass, G., Rao, I.B.R., Himabindu, D., SrinivasuluPseudo surface velocities (densities) and pseudo depth densities along profiles Dharwar Craton, India.Current Science, Vol.82,No.2, pp. 197-201.IndiaGeophysics - seismics, Craton - Dharwar
DS2002-1301
2002
Srinivasulu, N.Ramadass, G., Ramaprasada Rao, I.B., Himanbindu, D., Srinivasulu, N.Psuedo surface velocities ( densities) and pseudo depth densities ( velocities) along selected profiles in the Dharwar Craton, India.Current Science, Vol. 82,No. 2, Jan. 25, pp. 197-201.IndiaGeophysics - seismics
DS2003-1126
2003
Srinivasulu, N.Ramadass, G., Rao, I.B.R., Srinivasulu, N., Himabindu, D.Density studies in the Dharwar Craton along the Jadcharla Goa subtransectJournal Geological Society of India, Vol. 61, 4, pp. 439-448.IndiaGeophysics - seismics
DS200412-1615
2003
Srinivasulu, N.Ramadass, G., Rao, I.B.R., Srinivasulu, N., Himabindu, D.Density studies in the Dharwar Craton along the Jadcharla Goa subtransect.Journal Geological Society of India, Vol. 61, 4, pp. 439-448.IndiaGeophysics - seismics
DS1996-0554
1996
SriramaGowd, T.N., Srirama, Rao, S.V., Chary, K.B.Stress field and seismicity in the Indian shield: effects of the collision between India and Eurasia.Pure and Applied Geophysics, Vol. 146, No. 3-4, May 1, pp. 503-532.India, EurasiaTectonics, Geophysics -seismics
DS201212-0700
2012
Srivasta, R.K.Srivasta, R.K., Melluso, L., Petrone, C.M., Guarino, V., Sinha, A.K.Evolution of the Early Cretaceous alkaline Jasra complex, Shillong Plateau, northeastern India.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractIndiaDeposit - Jasra
DS201312-0726
2013
Srivastava, A.K.Radhakrishna, T., Chandra, R., Srivastava, A.K., Balasubramonian, G.Central/eastern Indian Bundelk hand and Bastar cratons in the Paleoproterozoic supercontinental reconstructions: a paleomagnetic perspective.Precambrian Research, Vol. 226, pp. 91-104.IndiaPaleomagnetism
DS201212-0461
2012
Srivastava, C.M.Melluso, L., Rajesh,K., Srivastava, C.M., Petrone, V., Guarino, V., Sinha, A.K.Mineralogy, magmatic affnity and evolution of the Early Cretaceous alkaline complex of Jasra, Shillong Plateau, northeastern India.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractIndiaDeposit - Jasra
DS200412-1895
2004
Srivastava, D.C.Srivastava, D.C.Origin and ductile shearing of the microgranitoid enclaves in the granulite granitoid terrane around Devariya Bandanwara area, cJournal Geological Society of India, Vol. 63, 6, pp. 587-610..India, RajasthanStructure
DS200712-0053
2007
Srivastava, G.P.Barman, S., Srivastava, G.P.Temperature dependence of the thermal conductivity of different forms of diamond.Journal of Applied Physics, Vol. 101, 12, June 15, 123507 (8p).TechnologyDiamond thermometry
DS2002-1467
2002
Srivastava, J.K.Shivana, S.,Srivastava, J.K.,Nambiar, A.R.Kimberlite occurrence in Raichur area, KarnatakaJournal Geological Society of India, Vol. 59,No.3,pp. 269-72.IndiaGeology, Deposit - Raichur area
DS2002-1470
2002
Srivastava, J.K.Shivanna, S., Srivastava, J.K., Nambiar, A.R.Kimberlite occurrence in Raichur area, Karnataka. Near UndraldoddiJournal of the Geological Society of India, Vol. 59, March, pp. 269-271.IndiaGeology - kimberlite
DS2002-1471
2002
Srivastava, J.K.Shivanna, S., Srivastava, J.K., Nambiar, A.R.Kimberlite occurrence in Raichur area, KarnatakaJournal Geological Society of India, Vol. 59, pp. 269-71.India, KarnatakaKimberlite
DS2002-1472
2002
Srivastava, J.K.Shivanna, S., Srivastava, J.K., Nambiar, A.R.Kimberlite occurrence in Raichur area, KarnatakaJournal of the Geological Society of India, Vol. 59, March pp. 269-271.India, KarnatakaPetrology
DS200412-1811
2002
Srivastava, J.K.Shivanna, S., Srivastava, J.K., Nambiar, A.R.Kimberlite occurrence in Raichur area, Karnataka.Journal of the Geological Society of India, Vol. 59, March pp. 269-271.India, KarnatakaPetrology
DS200612-0966
2001
Srivastava, J.K.Nambiar, A.R., Shivanna, S., Ahmed, M., Srivastava, J.K.Search for kimberlites in Karnataka - status and scope.National Seminar on Exploration Survey, Geological Society of India Special Publication, No. 58, pp. 603-613.India, KarnatakaDiamond exploration
DS200612-0967
2005
Srivastava, J.K.Nambiar, A.R., Shivanna, S., Srivastava, J.K.A preliminary report on the occurrence of manganoan ilmenite in kimberlites of Karnataka.Geological Society of India, Bangalore November Meeting Group Discussion on Kimberlites and Related Rocks India, Abstract p. 65-66.India, Karnataka, Dharwar CratonMineralogy
DS200612-1288
2005
Srivastava, J.K.Shivanna, S., Srivastava, J.K., Nambiar, A.R.Kimberlites of Raichur kimberlite field, Raichur district, Karnataka, southern India.Geological Society of India, Bangalore November Meeting Group Discussion on Kimberlites and Related Rocks India, Abstract p. 52-54.India, Karnataka, Dharwar CratonKimberlites - Raichur
DS201212-0143
2012
Srivastava, J.K.Das, J.N., Korkoppa, M.M., Fareeduddin, Shivana, S., Srivastava, J.K., Gera, N.L.Tuffisitic kimberlite from eastern Dharwar craton, Undraldoddi area, Raichur District, Karnataka, India10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractIndia, KarnatakaDeposit - Undraldoddi area
DS201412-0165
2013
Srivastava, J.K.Das, J.N., Korakoppa, M.M., Fareeduddin, Shivana, S., Srivastava, J.K., Gera, N.L.Tuffisitic kimberlite from eastern Dharwar craton, Undraldoddi area, Raichur district, Karnataka India.Proceedings of the 10th. International Kimberlite Conference, Vol. 2, pp. 109-128.India, KarnatakaDeposit - Raichur district
DS1980-0057
1980
Srivastava, M.Behal, S.C., Srivastava, M.Mineral Processing Plant for Recovery of Diamonds at Jungel, Mirzapur District, Uttar Pradesh.India Geological Survey Spec. Publishing, No. 4, PP. 633-637.India, Uttar PradeshMining Engineering
DS202005-0730
2020
Srivastava, P.Fareeduddin., Pant, N.C., Gupta, S., Chakraborty, P., Sensarma, S., Jain, A.K., Prasad, G.V.R., Srivastava, P., Rjan, S., Tiwari, V.M.The geodynamic evolution of the Indian subcontinent - an introduction.Episodes ( IUGS), Vol. 43, 1, pp. 1-18.Indiacarbonatite
DS202009-1627
2020
Srivastava, P.Fareeduddin, Pant, N.C., Gupta, S., Chakraborty, P., Sensarma, S., Jain, A.K., Prasad, G.V.R., Srivastava, P., Rajan, S., Tiwari, V.M.The geodynamic evolution of the Indian subcontinent - an introduction.Episodes, Vol. 43, 1, pp. 8p.Indiacarbonatites
DS1989-0862
1989
Srivastava, R.K.Le Bas, M.J., Srivastava, R.K.The mineralogy and geochemistry of the Mundwara carbonatite dykes, SirohiDistrict, Rajasthan, IndiaNeues Jahrb. F. Mineralogie, Abh, Vol. 160, No. 2, March, pp. 202-227IndiaGeochemistry, Carbonatite
DS1989-1443
1989
Srivastava, R.K.Srivastava, R.K.Alkaline and peralkaline rocks of RajasthanGeological Society of India, Memoir, Editor C. LeelanandaM., No. 15, pp. 3-24IndiaAlkaline rocks, Alkali-basaltic, nepheline
DS1994-1679
1994
Srivastava, R.K.Srivastava, R.K.Petrology, petrochemistry and genesis of alkaline rocks associated with the Ambadungar carbonatite complex, Baroda District, Gujarat India.Journal of the Geological Society of India, Vol. 43, No. 1, January pp. 23-39.IndiaCarbonatite, Geochemistry
DS1995-2016
1995
Srivastava, R.K.Wall, F., Le Bas, M.J., Srivastava, R.K.Carbonatite dykes at Sarnu -Dandali, Rajasthan, IndiaGeological Society Africa 10th. Conference Oct. Nairobi, p. 126-7. Abstract.IndiaCarbonatite, Deposit -Sarnu Dandali
DS1996-1358
1996
Srivastava, R.K.Srivastava, R.K.Petrology of the Proterozoic alkaline carbonatite complex of Samalpatti Tamil Nadu:carbonate-silicateInternational Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 383.IndiaCarbonatite, Liquid immiscibility
DS1997-1095
1997
Srivastava, R.K.Srivastava, R.K.Petrology, geochemistry and genesis of rift related carbonatites ofAmbadungar, India.Mineralogical Magazine, Vol. 61, No. 1-4, pp. 47-66.IndiaCarbonatite
DS2000-0900
2000
Srivastava, R.K.Sinha, A.K., Srivastava, R.K.Mesozoic mafic ultramafic ijolite carbonatite complexes of Assam MeghalayaPlateau, northeast India.Igc 30th. Brasil, Aug. abstract only 1p.India, northeastCarbonatite, Geochronology
DS2003-1322
2003
Srivastava, R.K.Srivastava, R.K., Singh, R.K.Geochemistry of high Mg mafic dykes from the Bastar Craton: evidence of LateCurrent Science, Vol. 85, 6, pp. 808-811.IndiaBoninite
DS200412-1896
2003
Srivastava, R.K.Srivastava, R.K., Singh, R.K.Geochemistry of high Mg mafic dykes from the Bastar Craton: evidence of Late Archean boninite like rocks in an intracratonic setCurrent Science, Vol. 85, 6, pp. 808-811.IndiaBoninites
DS200412-1897
2004
Srivastava, R.K.Srivastava, R.K., Singh, R.K.Trace element geochemistry and genesis of Precambrian sub-alkaline mafic dikes from the central Indian Craton: evidence for mantJournal of Asian Earth Sciences, Vol. 23, 3, pp. 373-389.IndiaMetamsomatism
DS200412-1898
2004
Srivastava, R.K.Srivastava, R.K., Singh, R.K., Verma, S.P.Neoarchean mafic volcanic rocks from the southern Bastar greenstone belt, central India: petrological and tectonic significance.Precambrian Research, Vol. 131, 3-4, pp. 305-322.IndiaTectonics - not specific to diamonds
DS200412-1899
2004
Srivastava, R.K.Srivastava, R.K., Sinha, A.K.Geochemistry of early Cretaceous alkaline ultramafic mafic complex from Jasra, Karbi Anglong, Shillong Plateau, northeastern IndGondwana Research, Vol. 7, pp. 549-561.IndiaAlkaline rocks, carbonatite
DS200412-1900
2004
Srivastava, R.K.Srivastava, R.K., Sinha, A.K.Trace element geochemistry and genesis of Precambrian sub-alkaline mafic dikes from the central Indian craton: evidence for mantJournal of Asian Earth Sciences, Vol. 23, 3, July, pp. 373-389.IndiaMantle metasomatism, Bastar
DS200412-1901
2004
Srivastava, R.K.Srivastava, R.K., Sinha, A.K.Early Cretaceous Sung Valley ultramafic alkaline carbonatite complex, Shitong Plateau, northeastern India: petrological and geneMineralogy and Petrology, Vol. 80, 3-4, March pp. 241-263.IndiaCarbonatite
DS200512-1035
2005
Srivastava, R.K.Srivastava, R.K., et al.Hot fluid driven metasomatism of Samalpatti carbonatites, south India: evidence from petrology, mineral chemistry, trace elements and stable isotopes.Gondwana Research, Vol. 8, 1, pp. 77-85.IndiaCarbonatite
DS200512-1036
2005
Srivastava, R.K.Srivastava, R.K., Heaman, L.M., Sinha, A.K., Shihua, S.Emplacement age and isotope geochemistry of Sung Valley alkaline carbonatite complex, Shillong Plateau, northeastern India: implications for primary carbonateLithos, Vol. 81, 1-4, April pp. 33-54.IndiaMelt, silicate rocks, geochronology, Kerguelen plume
DS200612-1354
2006
Srivastava, R.K.Srivastava, R.K.Geochemistry and petrogenesis of neoarchean high Mg low Ti mafic igneous rocks in an intracratonic setting, central India craton: evidence for boninite magmatism.Geochemical Journal, Vol. 40, 1, pp. 15-32.IndiaBoninites
DS200612-1355
2006
Srivastava, R.K.Srivastava, R.K.Geochemistry and petrogenesis of neoArchean high Mg low Ti mafic igneous rocks in and intracratonic setting, Central India craton: evidence for boninite magmatism.Geochemical Journal, Vol. 40, 1, pp. 15-32.Asia, IndiaMagmatism
DS200612-1356
2005
Srivastava, R.K.Srivastava, R.K., Chalapathi Rao, N.V.The Jungel Valley re-visited: evidence from the lamprophyres for the presence of a Paleoproterozoic carbonate rich metasomatised mantle in Mahakoshal beltGeological Society of India, Bangalore November Meeting Group Discussion on Kimberlites and Related Rocks India, Abstract p. 123.India, Madhya Pradesh, Aravalli Bundelkhand CratonMetasomatism
DS200712-1029
2007
Srivastava, R.K.Srivastava, R.K., Chalapathi Rao, N.V.Petrology, geochemistry and tectonic significance of Paleoproterozoic alkaline lamprophyres from the Jungel Valley, Mahakostal supracrustal belt, Central India.Mineralogy and Petrology, Vol. 89, 3-4, pp. 189-215.IndiaLamprophyre
DS200712-1030
2007
Srivastava, R.K.Srivastava, R.K., Gautam, G.C.Geochemistry of distinct mafic intrusive rocks from Darba-Kukanar and Kerlapal-Sukma-Mokhp southern Bastar Craton: further dat a on the Early Precambrian mafic magmatism of central India.Journal of the Geological Society of India, Vol. 69, 6, pp. 1176-1188.IndiaBastar Craton
DS200812-0201
2008
Srivastava, R.K.Chalapathi Rao, N.V., Srivastava, R.K.Petrology and geochemistry of Diamondiferous Mesoproterozoic kimberlites from Wajrakarur kimberlite field, eastern Dharwar craton, southern India: genesis and constraints on mantleContributions to Mineralogy and Petrology, Vol. 157, 2, pp. 245-265.IndiaDeposit - Wajrakarur
DS200812-0367
2008
Srivastava, R.K.French, J.E., Heaman, L.M., Chacko, T., Srivastava, R.K.1891-1883 Ma southern Bastar-Cuddapah mafic igneous events, India: a newly recognized large igneous province.Precambrian Research, Vol. 160, pp. 308-322.IndiaGeochronology - sill
DS200812-1106
2008
Srivastava, R.K.Srivastava, R.K.Global intracratonic boninite norite magmatism during the Neoarchean Paleoproterozoic: evidence from the Central Indian Bastar Craton.International Geology Review, Vol. 50, 1, pp. 61-74.IndiaBoninites
DS200812-1107
2008
Srivastava, R.K.Srivastava, R.K., Ahmad, T.Precambrian mafic magmatism in the Indian Shield: an introduction.Journal of the Geological Society of India, Vol. 72, 1, pp. 9-14.IndiaMagmatism
DS200812-1108
2008
Srivastava, R.K.Srivastava, R.K., Sivaji, Ch., Chalapathi Rao, N.V.Indian dykes Geochemistry, Geophysics and Geochronology,Narosa Press, India, 626p. narosa.comIndiaSpecific chapters cited seperately
DS200912-0104
2009
Srivastava, R.K.Chalapathi Rao, N.V., Dongre, A., Kamde, G., Srivastava, R.K., Sridhar, M., Kaminsky, F.V.Petrology, geochemistry and genesis of newly discovered Mesoproterozoic highly magnesian, calcite rich kimberlites from Siddanpalli, Eastern Dharwar CratonMineralogy and Petrology, Online availableIndiaProducts of subduction-related magmatic sources?
DS200912-0724
2009
Srivastava, R.K.Srivastava, R.K., Chalapathi Rao, N.V., Sinha, A.K.Cretaceous potassic intrusives with affinities to aillikites from Jharia area: magmatic expression of metasomatically veined and thinned lithospheric mantleLithos, AvailableIndiaSinghbhum Craton
DS200912-0725
2009
Srivastava, R.K.Srivastava, R.K., Chalapathi Rao, N.V., Sinha, A.K.Cretaceous potassic intrusives with affinities to aillikites from Jharia area: magmatic expression of metasomatically veined and thinned lithospheric mantleLithos, In press availableIndiaSinghbhum Craton
DS200912-0726
2009
Srivastava, R.K.Srivastava, R.K., Gautam, G.C.Precambrian mafic magmatism in the Bastar Craton - central India.Journal of the Geological Society of India, Vol. 73, 1, pp. 52-72.IndiaMagmatism
DS201012-0098
2010
Srivastava, R.K.Chalapathi Rao, N.V., Dongre, A., Kamde, G., Srivastava, R.K., Sridhar, M., Kaminisky, F.V.Petrology, geochemistry and genesis of newly discovered Mesoproterozoic highly magnesian, calcite rich kimberlites from Siddanpalli, eastern Dharwar Craton...Mineralogy and Petrology, Vol. 98, 1-4, pp. 313-328.IndiaSubduction related magmatic sources?
DS201012-0493
2010
Srivastava, R.K.Melluso, L., Srivastava, R.K., Guarino, V., Zanetti, A., Sinha, A.K.Mineral compositions and petrogenetic evolution of the ultramafic alkaline carbonatitic complex of Sung Valley, northeastern India.The Canadian Mineralogist, Vol. 48, 2, pp. 205-229.IndiaCarbonatite
DS201012-0746
2010
Srivastava, R.K.Srivastava, R.K., Gautam, G.C.Map of distinct early Precambrian mafic dyke swarms from the central Indian Bastar Craton and their possible relation with Paleosupercontinent and Large Igneous Province.International Dyke Conference Held Feb. 6, India, 1p. AbstractIndiaBastar Craton geochronology
DS201012-0747
2010
Srivastava, R.K.Srivastava, R.K., Mondal, S.K., Balaram, V., Gautam, G.C.PGE geochemistry of low Ti high Mg siliceous mafic rocks within the Archean Central Indian Bastar Craton: implications for magma fractionation.Mineralogy and Petrology, Vol. 98, 1-4, pp. 329-345.IndiaMagmatism - not specific to diamonds
DS201012-0748
2010
Srivastava, R.K.Srivastava, R.K., Sinka, A.K.Early Cretaceous alkaline carbonatite intrusions within the Shillong Plateau, eastern India.International Dyke Conference Held Feb. 6, India, 1p. AbstractIndiaAlkaline rocks, magmatism
DS201312-0141
2013
Srivastava, R.K.Chalapathi Rao, N.V., Sinha, A.K., Kumar, S., Srivastava, R.K.K rich titanite from the Jharia ultrapotassic rock, Gondwana coal fields, eastern India, and its petrological significance.Journal of the Geological Society of India, Vol. 81, 6, pp. 733-736.IndiaPetrology
DS201509-0430
2015
Srivastava, R.K.Srivastava, R.K., Gautam, G.C.Geochemistry and petrogenesis of Paleo-Mesoproterozoic mafic dyke swarms from northern Bastar craton, central India: geodynamic implications in reference to Columbia supercontinent.Gondwana Research, Vol. 28, pp. 1061-1078.IndiaDike swarms

Abstract: Field setting, petrography, geochemistry and available radiometric ages of Proterozoic mafic dykes from the northern Bastar craton have helped to identify four sets of mafic dykes; two Paleoproterozoic [viz. NW-SE North Bastar dykes (NBD) and ENE-WSW Dongargarh-Chhura dykes (DCD)] and two Mesoproterozoic [viz. 1.42 Ga ENE-WSW Bandalimal dykes (BDD) and 1.44 Ga N-S Lakhna dykes (LKD)]. Their petrographic and geochemical characteristics are very distinct and suggest their derivation from different mantle melts. Chemistry of all the four sets suggests different petrogenetic histories and samples of each distinct set are co-genetic nature. The NBD, the DCD and the BDD samples are sub-alkaline tholeiitic in nature, whereas the LKD samples show alkaline nature. Very distinct REE patterns are observed for all the four sets again suggesting their different petrogenetic histories. Geochemical comparison between the studied samples and mafic dyke samples of southern and central parts of the Bastar craton suggests very different picture for the northern Bastar craton. Only one set of northern Bastar dykes, i.e. the NBD, matches with BD1 dykes; no other dyke sets match with any of the dyke swarms identified in southern and central Bastar craton. Geochemically it is not straightforward to confirm crustal contamination, however, on the other hand, possibility of crustal contamination cannot be ruled out completely. A petrogenetic model based on trace element data suggests that all the four sets are derived from different mantle melts. The NBD and the DCD are probably generated within spinel stability field, whereas the BDD and the LKD may be derived from melts generated within garnet stability field. Available geological and geochemical data support the emplacement of studied dykes in a stable continental rift tectonic setting, however earlier intrusions have chemistry similar to N-MORB. The available geological, geochemical and geochronological data on the four indentified sets of mafic dykes from the northern Bastar craton indicate their relation to the assembly and break-up of Columbia supercontinent.
DS201607-1316
2016
Srivastava, R.K.Srivastava, R.K., Pimentel, M.M., Gautam, G.C.Nd-isotope and geochemistry of an early Paleoproterozoic high Si high Mg boninite-norite suite of rocks in the southern Bastar craton, central India: petrogenesis and tectonic significance.International Geology Review, Vol. 58, 13, pp. 1596-1615.IndiaBoninites

Abstract: Nd-isotope and lithogeochemistry of an early Palaeoproterozoic high-Si high-Mg boninite -norite (BN) suite of rocks from the southern Bastar craton, central India, are presented to understand their nature, origin, and tectonic setting of emplacement. Various types of evidence, such as field relationships, radiometric metamorphic ages, and the global distribution of BN magmatism, suggest emplacement in an intracratonic rift setting, commonly around 2.4 -2.5 Ga. On the basis of geochemistry these high-Si high-Mg rocks are classified as high-Ca boninites, high-Mg norites, and high-Mg diorites. Nd-isotope data indicate that the high-Mg norite and the high-Mg diorite samples are similar, whereas the high-Ca boninites have a different isotopic character. The high-Mg norite and the high-Mg diorite samples have younger TDM model ages than the high-Ca boninites. Geochemical and Nd-isotopic characteristics of the studied rocks indicate some prospect of crustal contamination; however, the possibility of mantle metasomatism during ancient subduction event cannot be ignored. Trace-element modelling suggests that the high-Ca boninites may have crystallized from a magma generated by a comparatively greater percentage of melting of a lherzolite mantle source than the source for the other two varieties. Furthermore, the high-Ca boninite rocks are most likely derived from an Archaean subduction process (the Whundo-type), whereas the other two types are the products of the interaction of subduction-modified refractory mantle wedge and a plume, around the Neoarchaean -Palaeoproterozoic boundary. The emplacement of the high-Mg norites and the high-Mg diorites may be linked to crustal thickening and associated cratonization at the end of the Archaean.
DS201608-1398
2016
Srivastava, R.K.Chalapathi Rao, N.V., Srivastava, R.K.Kimberlites, lamproites, lamprophyres, varbonatites, other alkaline rocks and mafic dykes from the Indian shield: glimpses of research ( 2012-2016).Proceedings National Academy of Sciences India , Vol. 82, 3, July special issue pp. 515-536.IndiaKimberlites, lamproites

Abstract: Major highlights of researches carried out on kimberlites, lamproites, lamprophyres, carbonatites, other alkaline rocks and mafic dykes from the Indian shield during 2012-2016 are presented. New findings involving field mapping, petrology, geochemistry (including high quality mineral based in situ isotopic studies) and geophysics have provided remarkable insights on the mode of their occurrence, timing of emplacement, mineralogy and bulk-rock composition, redox conditions, relative contribution of the lithosphere and asthenosphere, as well as their economic potential. Several large-scale geodynamic aspects such as plume-lithosphere interactions, ancient subduction events, layered structure of the sub-continental lithospheric mantle, spatial extent of the Precambrian large igneous provinces and supercontinent configurations could be unraveled from these studies on deep-mantle derived small-volume magmatic rocks.
DS201902-0317
2019
Srivastava, R.K.Samal, A.K., Srivastava, R.K., Ernst, R.E., Soderlund, U.Neoarchean-Mesoproterozoic mafic dyke swarms of the Indian shield mapped using google Earth images and ArcGIStm, and links with Large Igneous Provinces.Srivastava: Dyke Swarms of the World: a Modern Perspective, Springer, researchgate 56p. PdfIndiadykes

Abstract: We present dyke swarm maps generated using Google Earth™ images, ArcGIS™, field data, and available geochronological ages of Neoarchean-Mesoproterozoic (ranging in age from ~2.80 to ~1.10 Ga) mafic dyke swarms and associated magmatic units of the different Archean cratons of the Indian shield which represent the plumbing system of Large Igneous Provinces (LIPs). The spatial and temporal distributions together with the trends of the dyke swarms provide important informations about geodynamics. Twenty four dyke swarms (17 have been precisely dated), mostly mafic in nature, have been mapped from the different cratons and named/re-named to best reflect their location, trend, distribution and distinction from other swarms. We have identified 14 distinct magmatic events during the Neoarchean-Mesoproterozoic in the Indian shield. These intraplate magmatic events (many of LIP scale) of the Indian shield and their matches with coeval LIPs on other crustal blocks suggest connections of the Indian shield within known supercontinents, such as Kenorland/Superia (~2.75-2.07 Ga), Columbia/Nuna (1.90-1.38 Ga), and Rodinia (1.20-0.72 Ga). However, further detailed U-Pb geochronology and associated paleomagnetism are required to come to any definite constraints on the position of the Indian cratons within these supercontinents.
DS201904-0783
2019
Srivastava, R.K.Srivastava, R.K., Guarino, V., Wu, F-Y., Melluso, L., Sinha, A.K.Evidence of sub continental lithospheric mantle sources and open system crystallization processes from in situ U-Pb ages and Nd-Sr-Hf isotope geochemistry of the Cretaceous ultramafic alkaline (carbonatite) intrusions from the Shillong Plateau, north-eastLithos, Vol. 330, 1, pp. 108-119.Indiacarbonatite

Abstract: New in-situ U-Pb ages and Sr-Nd-Hf isotopic data on mineral phases of the Sung Valley and Jasra ultramafic-alkaline-(carbonatite) intrusions (Shillong Plateau, India) shed new light on the petrogenetic processes of volcanism in north-eastern India during the Cretaceous. Perovskites of Sung Valley dunite, ijolite and uncompahgrite yielded U-Pb ages of 109.1?±?1.6, 104.0?±?1.3 and 101.7?±?3.6?Ma, respectively. A U-Pb age of 106.8?±?1.5?Ma was obtained on zircons of a Sung Valley nepheline syenite. Perovskite of a Jasra clinopyroxenite yielded an age of 101.6?±?1.2?Ma, different from the U-Pb age of 106.8?±?0.8?Ma on zircon of Jasra syenites. The variation in Sr-Nd-Hf isotopic compositions [initial 87Sr/86Sr?=?0.70472 to 0.71080; ?Nd i?=??10.85 to +0.86; ?Hf i?=??7.43 to +1.52] matches the bulk-rock isotopic composition of the different rock units of Sung Valley and Jasra. Calcite and apatite in the carbonatites, the perovskite in a dunite, and the bulk-rock carbonatites of Sung Valley intrusion have the lowest initial 87Sr/86Sr and ?Nd, taken to be the best proxies of the mantle source composition, which is dominated by components derived from the lithospheric mantle. The alkaline intrusions of north-eastern India are significantly younger than the Sylhet tholeiitic magmatism. The silicate rocks of both intrusions have isotopic composition trending to that of the underlying Shillong crust, indicating the effects of fractional crystallization and low-pressure crustal contamination during the emplacement of the various intrusive magma pulses.
DS201905-1070
2019
Srivastava, R.K.Rai, A.K., Srivastava, R.K., Samal, A.K., Sesha Sai, V.V.Geochemistry, petrogenesis, and geodynamic implications of NE-SW to ENE - WSW trending Paleoproterozoic mafic dyke swarms from southern region of the western Dharwar Craton.Geological Journal, Doi: 10.1002/gj.3493Indiageodynamics

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

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

Abstract: Based on trend, cross-cutting relationships and U-Pb dating, Precambrian mafic dykes in the Singhbhum craton, earlier collectively identified as ‘Newer Dolerite Swarm’ have been separated into seven distinct swarms, which are thought to be the plumbing systems for Large Igneous Provinces (LIPs). These Singhbhum swarms range in age from ?2.80 Ga to ?1.76 Ga, and include the ?2.80 Ga NE-SW trending Keshargaria swarm, ?2.75-2.76 Ga NNE-SSW to NE-SW trending Ghatgaon swarm, the ?2.26 Ga NE-SW to ENE-WSW trending Kaptipada swarm (based on a new U-Pb ID-TIMS age 2256 ± 6 Ma), the ?1.77 Ga WNW-ESE trending Pipilia swarm, the early-Paleoproterozoic E-W to ENE-WSW trending Keonjhar swarm, the middle-Paleoproterozoic NW-SE to NNW-SSE trending Bhagamunda swarm, and the late-Paleoproterozoic N-S to NNE-SSW trending Barigaon swarm. Two of the Singhbhum swarms, the ?2.26 Ga Kaptipada and ?1.77 Ga Pipilia, are closely matched with the ?2.26-2.25 Ga Ippaguda-Dhiburahalli and ?1.79 Ga Pebbair swarms, respectively, of the eastern Dharwar craton. The correlations suggest that the Singhbhum and Dharwar cratons were close enough at these times to share two reconstructed LIPs, a 2.26-2.25 Ga Kaptipada- Ippaguda-Dhiburahalli LIP and a 1.79-1.77 Ga Pipilia-Pebbair LIP, and if so, both swarms must be present in the intervening Bastar craton (candidates are proposed). Also, the 2.76-2.75 Ga Ghatgaon swarm of the Singhbhum craton can be provisionally correlated with ?2.7 Ga Keshkal swarm of the Bastar craton. The 2.26-2.25 Ga Kaptipada-Ippaguda-Dhiburahalli LIP of the Singhbhum-Bastar-Dharwar reconstruction has age matches in the Vestfold Hills of Antarctica (?2.24 Ga dykes), the Kaapvaal craton (the ?2.25-2.23 Ga Hekpoort lavas) and perhaps the Zimbabwe craton (2.26 Ga Chimbadzi troctolite intrusions). The 1.76-1.79 Ga Pipilia-Pebbair LIP of the Singhbhum-Bastar-Dharwar reconstruction has age matches in the North China, Australian Shield, Amazonian, Rio de Plata and Sarmatia cratons. The relevance of these matches for reconstructions will require future testing using paleomagnetic studies. While there are ?2.7-2.8 Ga LIP-type greenstone belts in many crustal blocks, there are no precise matches with the 2.76-2.75 Ga Ghatgaon swarm of the Singhbhum craton. Howe
DS202009-1666
2020
Srivastava, R.K.Srivastava, R.K.Early Cretaceous alkaline-alkaline silicate and carbonatite magmatism in the Indian shield - a review: implications for a possible remnant of greater Kerguelen Large Igneous Province.Episodes, Vol. 43, 1, pp. 300-313.Indiacarbonatites

Abstract: The early Cretaceous (ca. 118-100 Ma) alkaline/ultraalkaline silicate and carbonatite magmatism, exclusively recorded in the Chhotanagpur Gneissic Complex and the Shillong Plateau-Mikir Hills in the eastern/northeastern regions of the Indian Shield, have been reviewed to understand their genetic aspects. These are thought to be associated to the Kerguelen hot spot, active in this region during ca. 118-100 Ma. The existing geochemical, geochronological and isotopic data do not support any definite emplacement order for these diverse groups of magmatic suites. It is likely that they were derived from distinct magma batches with direct or indirect involvement of the Kerguelen plume. The available data suggest their possible derivation from the depleted asthenosphere/lithosphere with negligible contribution from the Kerguelen mantle plume. It is likely that mantle plume provided additional heat necessary to melt the asthenosphere/lithosphere. These data also suggest effects of low-pressure crustal contamination, crystal accumulation and fractional crystallization, rather than mantle-derived heterogeneity. These identified magmatic events together with other known magmatic events such as southeastern Tibet, Abor volcanics, SW Australia and eastern Antarctica during ca. 140-100 Ma could be related to the Kerguelen plume and integral part of the Greater Kerguelen Large Igneous Province, and have possible impact on the breakup of East Gondwanaland.
DS202012-2233
2020
Srivastava, R.K.Melluso, L., Sethna, S.F., Srivastava, R.K.First occurrence of melilite, potassic richterite and tetraferriphlogopite in Deccan Trap- related alkaline rocks, and its petrogenetic significance: the Rajpuri ijolitenephlinite intrusion, Murud, Mumbai area, India.Journal of Mineralogy and Geochemistry, https://doi.org/ 10.1127/njma/2020/0236Indiamelilite
DS202205-0720
2022
Srivastava, R.K.Srivastava, R.K., Guarino, V., Melluso, L.Early Cretaceous ultramafic-alkaline-carbonatite magmatism in the Shilong Plateau-Mikir Hills, northeastern India - a synthesis.Mineralogy and Petrology, 10.1007/s00710-022-00777-z 20p. PdfIndiadeposit - Shilong Plateau

Abstract: A comprehensive mineralogical, geochemical and isotopic review of six ultramafic-alkaline-carbonatite magmatic intrusions of the Shillong Plateau (Sung Valley, Jasra, Swangkre-Rongjeng, and Mawpyut) and Mikir Hills (Samchampi-Samteran and Barpung) is presented here, using the published data. These intrusions emplaced ca. 115-102 Ma ago, thus are significantly younger than the tholeiitic flood basalts erupted in Rajmahal-Sylhet province (ca. 118-115 Ma). The intrusive lithologies vary from ultramafic (dunites, clinopyroxenites, melilitolites) to mafic (ijolites, gabbros sensu lato, shonkinites), to felsic (syenites, nepheline syenites) and carbonatites (mostly calcite-rich varieties). The volcanic-subvolcanic facies (lamprophyres, phonolites) are not abundant. The range of chemical compositions of the magmatic phases in the various assemblages is notable; the intrusive rocks are thus the result of crystallization of magmas from variably evolved, independent liquid-lines-of descent, generally of alkaline/strongly alkaline lineages and sodic-to-potassic in affinity. The large variations of the Sr-Nd isotopic ratios of the silicate intrusive rocks (sensu lato) suggest a role of shallow-level crustal contamination during their formation. The carbonatites of the Sung Valley and Samchampi-Samteran have different isotope ratios than the associated silicate rocks, have some isotopic affinity with the Group I tholeiitic basalts of Rajmahal Traps and have an ultimate genesis in a carbonate-bearing lithospheric mantle.
DS1989-0689
1989
Srivastava, R.M.Isaaks, E.H., Srivastava, R.M.Applied geostatisticsOxford University Press, 560p. Paperback approx.$35.00BookGeostatistics, Sampling data sets
DS1991-1578
1991
Srivastava, R.M.Shurtz, R.F., Srivastava, R.M., Isaaks, E.H.Comment and reply on the paper "study of probabilistic and deterministicgeostatistics"Mathematical Geology, Vol. 23, No. 3, April pp. 443-480. pp. 481-497GlobalGeostatistics, Probablilistic
DS200412-1902
2004
Srivastava, R.P.Srivastava, R.P., Chattopadhyay, S., Vedanti, N., Dimri, V.P.Gravity and magnetic studies over the circular geomorphic crater looking structures in the Narmada Traps, central India.Journal Geological Society of India, Vol. 64, 1, pp. 97-102.IndiaGeophysics - gravity, magnetics, Deccan basalts
DS201312-0678
2013
Srivastava, R.P.Pandey, O.P., Vedanti, N., Srivastava, R.P., Uma, V.Was Archean Dharwar craton ever stable? A seismic perspective.Journal of the Geological Society of India, Vol. 81, 6, pp. 774-780.IndiaGeophysics - seismics
DS201412-0660
2013
Srivastava, R.P.Pandev, O.P., Srivastava, R.P., Vedanti, N., Dutta, S., Dimri, V.P.Anomalous crustal and lithospheric mantle structure of southern part of the Vindhyan Basin and its geodynamic implications.Journal of Asian Earth Sciences, Vol. 91, pp. 316-328.IndiaGeophysics - seismics
DS201412-0719
2013
Srivastava, S.Rai, S.Borah, Kajaljyoti, Das, Gupta, R., Srivastava, S., Shalivahan, P., Sivaram, K., Kumar, K., Meena, S.The South India Precambrian crust and shallow lithospheric mantle: initial results from the India Deep Imaging Experiment ( INDEX).Journal of Earth System Science, Vol. 122, 6, pp. 1435-1453.IndiaDrilling
DS1990-1408
1990
Srivastava, S.P.Srivastava, S.P., Schouten, H., Roest, W.R., et al.Iberian plate kinetics: a jumping plate boundary between Eurasia andAfricaNature, Vol. 344, No. 6268, April 19, pp. 756-759NewfoundlandPlate tectonics, Iberian plate
DS1981-0394
1981
Srivastava, V.N.Srivastava, V.N., et al.Characteristic Geophysical Response Over Kimberlite Plugs And Other Ultrabasic Bodies in Jungel Valley, Mirzapur District, Utter Pradesh.India Geological Survey Spec. Publishing Geophysical Prospecting., India, Uttar PradeshKimberlite, Geophysics
DS200812-1109
2008
Srivastra, R.K.Srivastra, R.K., Chalapathi Rao, N.V., Sinha, A.K., Bharati, R.L.Petrology and geochemistry of the ultrapotassic alkaline intrusives from the Damodar valley, eastern Indian shield necessitate revision in IUGS ...9IKC.com, 3p. extended abstractIndiaUltrapotassic alkaline composition
DS200812-0199
2008
Srivisastra, R.K.Chalapathi Rao, N.V., Dongre, A., Kamde, G., Srivisastra, R.K., Sridhar, M., Kaminisky, F.V.Petrology, geochemistry and genesis of new Mesoproterozoic high magnesian calcite rich kimberlites of Siddanpalli, eastern Dharwar Craton...products9IKC.com, 3p. extended abstractIndiaSubduction related magmatic sources?
DS201412-0879
2014
SRK Consulting and friendsSRK Consulting and friendsPDAC Short course Primary diamond deposits: information required to support robust business decisions related to project acquisition and investment.PDAC Short course, SC no. 7 March 1 (one day)GlobalShort course advertisement
DS1989-0755
1989
Sruoga, P.Kay, S.M., Ramos, V.A., Mpodozis, C., Sruoga, P.Late Paleozoic to Jurassic silicic magmatism at theGondwanamargin:analogy to the middle Proterozoic in North America?Geology, Vol. 17, No. 4, April pp. 324-328MidcontinentTectonics
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
 
 

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