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

SDLRC - Scientific Articles all years by Author - A-An


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 - A-An
Posted/
Published
AuthorTitleSourceRegionKeywords
DS0812-0641
2008
A.Lee, C-T A., Luffi, P., Hoink, T., Li, Z-X.,A., Lenardic, A.The role of serpentine in preferential craton formation in the late Archean by lithosphere underthrusting.Earth and Planetary Science Letters, Vol. 269, 1-2, May 15, pp. 96-104.MantleGeochronology - cratons
DS1860-0327
1880
A.H. Smith And CoA.H. Smith And CoA Short Sketch of the African Diamond MinesA.h. Smith And Co., 12P.Africa, South AfricaMineralogy, Morphology
DS1975-0902
1979
A.O. Australia Pty. LtdA.O. Australia Pty. LtdEl 1626, El 1627, El 1629, El 1630, El 1649, El 1651, El 1704, El 1705 Final Report 1977-1979.Northern Territory Geological Survey Open File Report, No. CR 80/031, 11P.Australia, Northern TerritoryProspecting, Geochemistry, Sampling
DS1975-0903
1979
A.O. Australia Pty. LtdA.O. Australia Pty. LtdEl 1768 Annual Report on Exploration for Period Ending 5/12/79.Northern Territory Geological Survey Open File Report, No. CR 80/101, 17P.Australia, Northern TerritoryProspecting, Sampling, Geophysics
DS1806-1229
2018
Aadhiseshan, K.R.Jayananda, M., Santosh, M., Aadhiseshan, K.R.Formation of Archean (3600-2500 Ma) continental crust in the Dharwar craton, southern India.Earth Science Reviews, Vol. 181, pp. 12-42.Indiageodynamics

Abstract: The generation, preservation and destruction of continental crust on Earth is of wide interest in understanding the formation of continents, cratons and supercontinents as well as related mineral deposits. In this contribution, we integrate the available field, petrographic, geochronologic, elemental Nd-Hf-Pb isotope data for greenstones, TTG gneisses, sanukitoids and anatectic granites from the Dharwar Craton (southern India). This review allows us to evaluate the accretionary processes of juvenile crust, mechanisms of continental growth, and secular evolution of geodynamic processes through the 3600-2500?Ma window, hence providing important insights into building of continents in the Early Earth. The Dharwar Craton formed by assembly of micro-blocks with independent thermal records and accretionary histories. The craton can be divided into three crustal blocks (western, central and eastern) separated by major shear zones. The western block contains some of the oldest basement rocks with two generations of volcano-sedimentary greenstone sequences and discrete potassic plutons whereas the central block consist of older migmatitic TTGs, abundant younger transitional TTGs, remnants of ancient high grade supracrustal rocks, linear volcanic-dominated greenstone belts, voluminous calc-alkaline granitoids of sanukitoid affinity and anatectic granites. In contrast, the eastern block comprises younger transitional TTGs, abundant diatexites, thin volcanic-sedimentary greenstone belts and calc-alkaline plutons. Published geochronologic data show five major periods of felsic crust formation at ca. 3450-3300?Ma, 3230-3150?Ma, 3000-2960?Ma, 2700-2600?Ma, and 2560-2520?Ma which are sub-contemporaneous with the episodes of greenstone volcanism. U-Pb ages of inherited zircons in TTGs, as well as detrital zircons together with Nd-Pb-Hf isotope data, reveal continental records of 3800-3600?Ma. The U-Pb zircon data suggest at least four major reworking events during ca. 3200?Ma, 3000?Ma, 2620-2600?Ma, and 2530-2500?Ma corresponding to lower crustal melting and spatially linked high grade metamorphic events. The TTGs are sub-divided into the older (3450-3000?Ma) TTGs and the younger (2700-2600?Ma) transitional TTGs. The older TTGs can be further sub-divided into low-Al and high-Al groups. Elemental and isotopic data suggest that the low-Al type formed by melting of oceanic island arc crust within plagioclase stability field. In contrast, the elemental and isotopic features for the high-Al group suggest derivation of their magmatic precursor by melting of oceanic arc crust at deeper levels (55-65?km) with variable garnet and ilmenite in residue. The transitional TTGs likely formed by melting of composite sources involving both enriched oceanic arc crust and sub-arc mantle with minor contamination of ancient crustal components. The geochemical and isotopic compositions of granitoids with sanukitoid affinity suggest derivation from enriched mantle reservoirs. Finally, anatectic granites were produced by reworking of crustal sources with different histories. In the light of the data reviewed in this contribution, we propose the following scenario for the tectonic evolution of the Dharwar Craton. During 3450-3000?Ma, TTGs sources (oceanic arc crust) formed by melting of down going slabs and subsequent melting of such newly formed crust at different depths resulted in TTG magmas. On the contrary, by 2700?Ma the depth of slab melting increased. Melting of slab at greater depth alongside the detritus results in enriched melts partly modified the overlying mantle wedge. Subsequent melting of such newly formed enriched oceanic arc crust and surrounding arc-mantle generated the magmatic precursor to transitional TTGs. Finally at ca. 2600-2560?Ma, eventual breakoff of down going slab caused mantle upwelling which induced low degree (10-15%) melting of overlying enriched mantle at different depths, thereby, generating the sanukitoid magmas which upon emplacement into the crust caused high temperature metamorphism, reworking and final cratonization.
DS1012-0395
2010
Aanyu, K.Koehm, D., Lindenfeld, M., Rumpker, G., Aanyu, K., Haines, S., Passchier, C.W., Sachu, T.Active transgression faults in rift transfer zones: evidence for complex stress fields and implications for crustal fragmentation processes in the western branchInternational Journal of Earth Sciences, Vol. 99, 7, pp. 1633-1642.Africa, East AfricaEast African Rift
DS1012-0444
2010
Aanyu, K.Link, K., Koehm, D., Barth, M.G., Tiberindwa, J.V., Barifaijo, E., Aanyu, K., Foley, S.F.Continuous cratonic crust between the Congo and Tanzania blocks in western Uganda.International Journal of Earth Sciences, Vol. 99, 7, pp. 1559-1573.Africa, Uganda, TanzaniaGeophysics - seismics
DS1612-2350
2016
Aarab, E.M.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
DS1975-0513
1977
Aarden, H.M.Garcia, V., Aarden, H.M.Analysis Preliminar de Correlaciones Y Agrupaciones Geo-quimicas En Lateritas Del Cerro Impacto, Estado Bolivar.Fith. Congreso Geologico Venezolano, PP. 941-946.South America, VenezuelaLaterite, Geochemistry, Analyses
DS2001-0626
2001
Aaro, S.Korje, A., Heikkinen, P., Aaro, S.Crustal structure of the northern Baltic Sea paleoriftTectonophysics, Vol. 331, No. 4, Feb. 28, pp. 341-58.Baltic SeaTectonics - rifting
DS1995-1538
1995
Aaros, S.Raisanen, M.L., Tarvainen, T., Aaros, S.NORMA - a program to calculate a normative mineralogy for glacial tills and rocks from chemical analysis.Gff., Vol. 117, pp. 215-224.GlobalGeomorphology, Computer Program - NORMA.
DS1994-0001
1994
Ababou, R.Ababou, R., Bagtzoglou, A.C., Wood, E.F.On the condition number of covariance matrices in kriging, estimation, and simulation of random fieldsMathematical Geology, Vol. 26, No. 1, pp. 99-133GlobalGeostatistics, Kriging
DS2000-0157
2000
Abaca-Hernandez, F.Chica-Olmo, M., Abaca-Hernandez, F.Computing geostatistical image texture for remotely sensed dat a classification.Computers and Geosciences, Vol. 26, No. 4, Apr. pp. 373-84.GlobalComputer - Program, Remote sensing - not specific to diamond
DS1312-0741
2013
Abad, I.Reolid, M., Sacchez-Gomez, M., Abad, I., Gomez-Sanchez, M.E., de Mora, J.Natural monument of the Volcano of Cancarix, Spain: a case of lamproite phreatomagmatic volcanism.Geoheritage, Vol. 5, 1, pp. 35-45.Europe, SpainLamproite
DS1212-0270
2012
Abad, J.D.Guneralp, I., Abad, J.D., Zolezzi, G., Hooke, J.Advances and challenges in meandering channels research.Geomorphology, Vol. 163-164, pp. 1-9.TechnologyMeandering channels - issue (not specific to diamonds)
DS1504-0204
2015
Abakumov, A.M.Kaminsky, F.V., Ryabchikov, I.D., McCammon, C.A., Longo, M., Abakumov, A.M., Turner, S., Heidari, H.Oxidation potential in the Earth's lower mantle as recorded by ferropericlase inclusions in diamond.Earth and Planetary Science Letters, Vol. 417, pp. 49-56.South America, BrazilDeposit - Juina
DS1995-0001
1995
Abalos, B.Abalos, B., Cusi, J.D.Correlation between seismic anisotropy and major geological structures in southwest Liberia: a case study on continental lithosphere deformation.Tectonics, Vol. 14, No. 4, Aug. pp. 1021-40.GlobalLithosphere, tectonics
DS0412-1226
2003
Abart, R.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
DS0912-0599
2009
Abart, R.Prenzel, J., Abart, R., Keller, L.Complex chemical zoning in eclogite facies garnet reaction rims: the role of grain boundary diffusion.Mineralogy and Petrology, Vol. 95, 3-4, pp. 303-313.TechnologyMineral chemistry
DS1012-0255
2010
Abart, R.Guzmics, T., Mitchell, R.H., Szabo, C., Berkesi, M., Milke, R., Abart, R.Carbonatite melt inclusions in coexisting magnetite, apatite and monticellite in Kerimasi calciocarbonatite, Tanzania: melt evolution and petrogenesis.Contributions to Mineralogy and Petrology, Vol. 161, 2, pp. 177-196.Africa, TanzaniaCarbonatite
DS1112-0675
2011
Abart, R.Milke, R., Abart, R., Keller, L., Rhede, D.The behaviour of Mg, Fe, and Ni during the replacement of olivine by orthopyroxene: experiments relevant to mantle metasomatism.Mineralogy and Petrology, In press available, 8p.MantleMetasomatism
DS1112-0676
2011
Abart, R.Milke, R., Abart, R., Keller, L., Rhede, D.The behaviour of Mg, Fe and Ni during the replacement of olivine by orthopyroxene: experiments relevant to mantle metasomatism.Mineralogy and Petrology, In press available, 8p.MantlePeridotite, xenoliths
DS2003-0876
2003
Abart, R.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
DS1991-1368
1991
Abate, R.Popplewell, G., Abate, R.The application of modular plants to diamond recovery #1The Canadian Mining and Metallurgical Bulletin (CIM Bulletin) ., Session, Vol. 84, No. 947, March p. 99. AbstractGlobalDiamond recovery, Mining applications-processing
DS1991-0001
1991
Abate, R.L.Abate, R.L.Ore designed modular plants for small scale mining operations in Third World countriesInstitute of Mining and Metallurgy (IMM) Newsletter, December pp. 19-21AfricaDiamond recovery, Sortex, alluvial mining
DS1993-0002
1993
Abate, R.L.Abate, R.L.The design and development of modular process plants for small scale diamond mining operations #1Prospectors and Developers Diamond Workshop, held March 27th, Toronto, 7pSouth AfricaMining, Processing plants
DS1994-0002
1994
Abate, R.L.Abate, R.L.The design and development of modular process plants for small scale diamond mining operations #2The Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Section, p. 69. abstractNorthwest TerritoriesMining, Mineral processing plants
DS1997-0002
1997
Abate, R.L.Abate, R.L.A review of marine diamond mining and processing. Points of interest28th. Annual Underwater Mining Institute, 6p.South Africa, NamibiaMarine mining, Overview
DS1507-0333
2015
Abazova, Z.M.Sazonova, L.V., Nosova, A.A., Kargin, A.V., Borisovskiy, S.E., Tretyachenko, V.V., Abazova, Z.M., Griban, Yu.G.Olivine from the Pionerskaya and V. Grib kimberlite pipes, Arkangelsk diamond province, Russia: types, composition, and origin.Petrology, Vol. 23, 3, pp. 227-258.RussiaDeposit - Grib
DS2002-1460
2002
Abbaschian, R.Shigley, J.E., Abbaschian, R., Clarke, C.Gemesis laboratory created diamonds. a study of the jewelry quality yellow synthetic diamonds being grown on a commercial scale by Genesis Corp. Sarasota FloridaGems & Gemology, Vol. 38, 4, pp. 301-310.GlobalDiamond - synthesis, Economics
DS1998-0001
1998
Abbasi, K.Abbasi, K.uranium-lead (U-Pb) zircons dates from lower crustal xenoliths, State Line kimberlitedistrict, Colorado.Geological Society of America (GSA) Annual Meeting, abstract. only, p.A352.ColoradoGeochronology, State Line District
DS1992-0001
1992
Abbey, S.Abbey, S.Evaluation and application of reference materials for the analysis of rock sand mineralsChemical Geology, Vol. 95, No. 1-2, January 1, pp. 123-130GlobalGeochemistry -analysis, Rocks and minerals -overview
DS1988-0221
1988
Abbinett, D.Forsyth, D.A., Thomas, M.D., Broome, J., Abbinett, D., Halpenny, J.Regional geophysics of the central metasedimentary beltGeological Society of America (GSA) Abstract Volume, Vol. 20, No. 5, March p. 344. abstractGlobalBlank
DS1990-0485
1990
Abbinett, D.Forsyth, D.A., Pilkington, M., Grieve, R.A.F., Abbinett, D.Major circular structure beneath southern Lake Huron defined from potential field dataGeology, Vol. 18, No. 8, August pp. 773-777Ontario, Great LakesGeophysics -aeromagnetics, Tectonics
DS1810-2292
2018
Abbo, A.Abbo, A., Avigad, D., Gerdes, A.The lower crust of the Northern broken edge of Gondwana: evidence for sediment subduction and syn-Variscan anorogenic imprint from zircon U-Pb-Hf granulite xenoliths.Gondwana Research, Vol. 64, pp. 84-96.Europesubduction

Abstract: The continental basement in the Eastern Mediterranean represents the northern edge of Gondwana, which has been the site of repeated crustal accretion and has subsequently been modified by consecutive rifting events. We investigated the geologic and thermal history of the North Gondwana lower crust by examining the U-Pb-Hf isotope systematics in zircons within 6 mafic granulite xenoliths from Pliocene lava cone in North Israel. The lava cone protrudes through the platform cover that seals the late Neoproterozoic junction between the Arabian-Nubian basement to the South and the Cadomian basement exposed in the Taurides to the North. The mafic granulite xenoliths are composed of plagioclase + orthopyroxene + clinopyroxene ± garnet ± spinel ± secondary amphibole. U-Pb zircon ages from the granulites vary among the different samples with distinct zircon age populations at 400-1200 Ma, 170-350 Ma, and 3.6-4.2 Ma, attesting the lower crust preserves a prolonged thermal and igneous history. While 400-550 Ma U-Pb ages are interpreted to be the result of Pb loss, the wide scatter of zircon grains aged between 550 and 1200 Ma, alongside their diverse eHf(t) values (-25-+10), is an extraordinary evidence for the accretion of Neoproterozoic sediments into the North Gondwana arc root lower crust. The U-Pb-Hf signature of these zircons resembles Cadomian sediments of the Tauride block to the north, indicating southward (present coordinates) subduction under North Gondwana and possible accretion of fore-arc sediments to the lower crust through relamination in the latest Neoproterozoic. One xenolith contained metamorphic-shaped zircons aged 170-350 Ma with positive eHf values and Hf-TDM of 0.85 Ga interpreted to reflect Paleozoic recycling of the Neoproterozoic juvenile Arabian basement, which we consider to form a major component of the lower crust in the region. An overwhelming cluster of Carboniferous zircons concentrating at 305 Ma with exclusively negative eHf values around -6, was retrieved from three xenoliths. Some of these zircons portrayed igneous textures and shape. While Carboniferous igneous activity is the hallmark of Western Europe's Variscan orogeny, the latter did not affect the southern rifted edge of Neo-Tethys where our xenoliths were retrieved. The Paleozoic age-Hf composition in our xenoliths is therefore interpreted to result from syn-Variscan recycling of Neoproterozoic sedimentary remains in the lower crust, and some degree of melting in a non-orogenic environment. Rather than with horizontal plate motions and orogeny, the Carboniferous zircon ages in the xenoliths appear to coalesce with significant vertical movements that created continental scale unconformities and a broad basin and swell architecture known to develop over the entire North Gondwana margin at that time. The Carboniferous aged zircons in northern Israel lower crustal xenoliths are therefore a unique gauge of the thermal perturbation that accompanied the large-scale mantle dynamics below the then passive North African margin of Gondwana, while Variscan orogenic accretion occurred on the Eurasian margin. These lower crustal granulites xenoliths therefore contain important information with respect to the nature of the lower crust under Israel, with implications on the geodynamic setting during the Cadomian and Variscan cycles.
DS2001-1157
2001
AbbottThorkelson, FD.J., Mortensen, Creaser, Davidson, AbbottEarly Proterozoic magmatism in Yukon: constraints on the evolution of northwestern Laurentia.Canadian Journal of Earth Science, Vol. 38, No. 10, Oct. pp. 1479-94.YukonMagmatism - not specific to diamonds
DS1970-0458
1972
Abbott, A.L.Abbott, A.L.Gem Trails of CaliforniaAnaheim: Privately Publishing, 84P.CaliforniaKimberlite
DS1989-0001
1989
Abbott, D.Abbott, D., Anders, M.Identifying Precambrian hotspots: the Limpopo beltEos, Vol. 70, No. 43, October 24, p. 1357. AbstractSouthern AfricaBeitbridge, Diamonds
DS1990-0101
1990
Abbott, D.Abbott, D., Menke, W.Length of the global plate boundary at 2.4 GaGeology, Vol. 18, No. 1, January pp. 58-61GlobalCraton, Size of the plates
DS1992-0002
1992
Abbott, D.Abbott, D.Sailing continents: the extent of >1.6 1.8 Ga basementEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p. 323MantleKimberlite, lamproite, Xenoliths
DS1994-0003
1994
Abbott, D.Abbott, D., Burgess, L., Longhi, J., Smith, W.H.F.An empirical thermal history of the Earth's upper mantleJournal of Geophy. Res., Vol. 99, No. B7, July 10, pp. 13, 385-13, 850.MantleGeothermometry
DS1994-0004
1994
Abbott, D.Abbott, D., Drury, R., Smith, W.H.F.Flat to steep transition in subduction styleGeology, Vol. 22, No. 10, October pp. 937-940MantleSubduction
DS1994-0005
1994
Abbott, D.Abbott, D., Drury, R., Smith, W.H.F.Flat to steep transition in subduction styleGeology, Vol. 22, No. 10, October pp. 937-940.MantleTectonics, Subduction
DS1995-0002
1995
Abbott, D.Abbott, D., Mooney, W.The structural and geochemical evolution of the continental crust -support for oceanic plateau model.Review Geophysics, Vol. 33, No. 5, pp. 231-242.MantleGeochemistry, Crust -structure
DS1996-1181
1996
Abbott, D.Riccardi, K., Abbott, D.Increased mantle convection during the Mid Cretaceous- a comparative studyof mantle potential temperature.Journal of Geophysical Research, Vol. 101, No. B4, April 10, pp. 8673-8684.MantleSubduction
DS1996-1377
1996
Abbott, D.Stoddart, P.R., Abbott, D.Influence of the tectonsphere upon plate motionJournal of Geophysical Research, Vol. 101, No. B3, March 10, pp. 5425-33.MantleTectonics
DS1998-0002
1998
Abbott, 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
DS1998-1031
1998
Abbott, D.Mooney, W.D., Abbott, D.The formation of continental crust and lithosphere: a synthesis based on seismic reflection profiling...Geological Society of America (GSA) Annual Meeting, abstract. only, p.A109.MantleTectonic, Lithoprobe
DS1999-0223
1999
Abbott, D.Franco, H., Abbott, D.Gravity signatures of terrane accretionLithos, Vol. 46, pp. 5-16.MantleGeophysics - gravity, Tectonics - not specific to diamonds
DS2000-0001
2000
Abbott, 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
DS2001-0205
2001
Abbott, D.Condie, K.C., Des Marais, D.J., Abbott, D.Precambrian superplumes and supercontinents: a record in black shales, carbon isotopes and paleoclimates.Precambrian Research, Vol. 106, No. 3-4, Mar. 1, pp. 239-60.MantleHot spots
DS1996-0001
1996
Abbott, D.G.Abbott, D.G., Camp, D.C.The use of new microtunneling technology to escavate hard rock in a miningapplicationSociety for Mining, Metallurgy and Exploration (SME)-American Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint, 96-19United StatesMining, Underground
DS0412-2015
2003
Abbott, D.H.Trubitsyn, V.P., Mooney, W.D., Abbott, D.H.Cold cratonic roots and thermal blankets: how continents affect mantle convection.International Geology Review, Vol. 45, 6, pp. 479-96.MantleTectonics
DS1312-0001
2013
Abbott, D.H.Abbott, D.H., Mooney, W.D., Van Tongeron, J.A.The character of the Moho and lower crust within Archean cratons and the tectonic implications.Tectonophysics, Vol. 609, pp. 690-705.Africa, South Africa, ZimbabweKaapvaal Craton
DS1996-0002
1996
Abbott, D.H.Abbott, D.H.Plumes and hotspots as sources of greenstone beltsLithos, Vol. 37, No. 2/3, April pp. 113-128MantleGreenstone belts, Plumes, hotspots
DS1997-0003
1997
Abbott, D.H.Abbott, D.H., Drury, R., Mooney, W.D.Continents as lithological icebergs: the importance of buoyant lithospheric roots.Earth and Planetary Science Letters, Vol. 149, No. 1-4, pp. 15-27.MantleTectonics, Subduction, mantle, Lithospheric roots, Continental Crust
DS1997-0004
1997
Abbott, D.H.Abbott, D.H., Drury, R., Mooney, W.D.Continents as lithological icebergs: the importance of bouyant lithosphericroots.Earth and Planetary Science Letters, Vol. 149, pp. 15-27.Russia, Europe, UralsSubduction, plumes, Oceanic crust
DS2000-0002
2000
Abbott, D.H.Abbott, D.H.Do large impacts strengthen mantle plumes and produce komatiites?Geological Society of America (GSA) Abstracts, Vol. 32, No. 7, p.A-314.MantleImpacts
DS2002-0002
2002
Abbott, D.H.Abbott, D.H., Isley, A.E.The intensity, occurrence and duration of superplume events and eras over geological time.Journal of Geodynamics, Vol.34, 2, Sept. pp. 265-307.GlobalTectonics, Geochronology
DS2002-0003
2002
Abbott, D.H.Abbott, D.H., Isley, A.E.Extraterrestrial influence on mantle plume activityEarth and Planetary Science Letters, Vol. 205, 1-2, pp. 53-62.MantleHot spots, plumes
DS2002-0004
2002
Abbott, D.H.Abbott, D.H., Isley, A.E.The intensity, occurrence and duration of superplume events and eras over geological timeJournal of Geodynamics, Vol. 34, 2, pp. 265-307.MantleTectonics
DS2002-0751
2002
Abbott, D.H.Isley, A.E., Abbott, D.H.Implications of the temporal distribution of high Mg magmas for mantle plume volcanism through time.Journal of Geology, Vol.110, 2, pp. 141-58.MantleMagmatism, high magnesium magmas, Plume - hot spots
DS2002-0752
2002
Abbott, D.H.Isley, A.E.,Abbott, D.H.Implications of the temporal distribution of high Mg magmas for mantle plume volcanism through time.Journal of Geology, Vol.110,No.2,pp.141-58.GlobalUltramafics, komatiites, meimcheites, picrites, Plume - time series, geochronology
DS2003-1390
2003
Abbott, D.H.Trubitsyb, V.P., Mooney, W.D., Abbott, D.H.Cold cratonic roots and thermal blankets: how continents affect mantle convectionInternational Geology Review, Vol. 45, 6, pp. 479-96.MantleTectonics
DS2003-1392
2003
Abbott, D.H.Trubitsyn, V.P., Mooney, W.D., Abbott, D.H.Cold cratonic roots and thermal blankets: how continents affect mantle convectionInternational Geology Review, Vol. 45, 6, June pp. 479-96.MantleConvection, Geothermometry
DS0412-1771
2004
Abbott, G.Schwab, D.L., Thorkelson, D.J., Mortensen, J.K., Creaser, R.A., Abbott, G.The Bear River dykes (1265-1269) Ma): westward continuation of the Mackenzie dyke swarm into Yukon, Canada.Precambrian Research, Vol. 133, no. 3-4, Aug. 20, pp.175-186.Canada, YukonDyke swarms, geochronology
DS1995-0003
1995
Abbott, G.Abbott, G.Overview of MDD field trip to northeast Russia in September 1994The Gangue, No. 47, Jan. pp. 1, 3-5, 8RussiaFieldtrip overview
DS1993-0003
1993
Abbott, R.Abbott, R., Champigny, N.Implementing management systems... EMS (environmental management system)Mining Environmental Management, pp. 4, 5CanadaEnvironmental, Management systems
DS1997-0005
1997
Abbott, R.M.Abbott, R.M.Strategic mining environmental managementNorth American Mining, June pp. 16-17United StatesMining - environment, Legal
DS1900-0284
1905
Abbott, W.J.L.Abbott, W.J.L.Gemmological Tables for the Use of Diamond and Gem Merchants; Jewellers and Students.London:, 4 SHEETS.GlobalDiamond Cutting, Standards
DS1996-0720
1996
Abbruzzi, J.M.Kay, S.M., Abbruzzi, J.M.Magmatic evidence for Neogene lithospheric evolution of the central Andean'flat-slab' between 30 and 23 deg S.Tectonophysics, Vol. 259, No. 1-3, June 30, pp. 15-28Andes, Cordillera, Bolivia, ArgentinaSubduction, Tectonics
DS1996-0873
1996
Abbruzzi, J.M.Mahlburg Kay, S., Orrell, S., Abbruzzi, J.M.Zircon and whole rock neodymium lead isotopic evidence for a Grenville age and a Laurentian Origin for the basementJournal of Geology, Vol. 104, No. 6, Nov. pp. 637-648ArgentinaGeochronology, Precordillera
DS1412-0088
2014
Abdallah, N.Caby, R., Bruguier, O., Fernandez, L., Hammor, D., Bosch, D., Mechati, M., Laouar, R., Ouabadi, A., Abdallah, N., Douchet, C.Metamorphic diamonds in a garnet megacryst from the Edough Massif (northeastern Algeria)… Recognition and geodynamic consequences.Tectonophysics, Vol. 637, pp. 341-353.Africa, AlgeriaEdough Massif
DS1709-1965
2017
Abdallah, N.Bruguier, O., Bosch, D., Caby, R., Vitale-Brovarone, A., Fernadez, L., Hammor, D., Laouar, R., Ouabadi, A., Abdallah, N., Mechanti, M.Age of UHP metamorphism in the Western Mediterranean: insight from rutile and minute zircon inclusions in a diamond bearing garnet megacryst ( Edough Massif, NE Algeria).Earth and Planetary Science Letters, Vol. 474, pp. 215-225.Africa, Algeriadiamond inclusions

Abstract: Diamond-bearing UHP metamorphic rocks witness for subduction of lithospheric slabs into the mantle and their return to shallow levels. In this study we present U-Pb and trace elements analyses of zircon and rutile inclusions from a diamond-bearing garnet megacryst collected in a mélange unit exposed on the northern margin of Africa (Edough Massif, NE Algeria). Large rutile crystals (up to 300 µm in size) analyzed in situ provide a U-Pb age of 32.4 ± 3.3 Ma interpreted as dating the prograde to peak subduction stage of the mafic protolith. Trace element analyses of minute zircons (=30 µm) indicate that they formed in equilibrium with the garnet megacryst at a temperature of 740-810 °C, most likely during HP retrograde metamorphism. U-Pb analyses provide a significantly younger age of 20.7 ± 2.3 Ma attributed to exhumation of the UHP units. This study allows bracketing the age of UHP metamorphism in the Western Mediterranean Orogen to the Oligocene/early Miocene, thus unambiguously relating UHP metamorphism to the Alpine history. Exhumation of these UHP units is coeval with the counterclockwise rotation of the Corsica-Sardinia block and most likely resulted from subduction rollback that was driven by slab pull.
DS1993-0004
1993
Abdel Raman, E.M.Abdel Raman, E.M., et al.A new ophiolite occurrence in northwest Sudan - contraints on late Proterozoictectonism.Terra Nova, Vol. 2, pp. 363-76.GlobalTectonics, Ultramafic volcanism.
DS1412-0001
2014
Abdelfadil, K.M.Abdelfadil, K.M., Romer, R.L., Glodny, J.Mantle wedge metasomatism revealed by Li isotopes in orogenic lamprophyres. ( Bohemian Massif)Lithos, Vol. 196-197, pp. 14-26.EuropeLamprophyre
DS1312-0002
2013
Abdelfadil, Kh.M.Abdelfadil, Kh.M., Romer, R.L., Seifert, Th., Lobst, R.Calc-alkaline lamprophyres from Lusatia ( Germany) - evidence for a repeatedly enriched mantle source.Chemical Geology, Vol. 353, pp. 230-245.Europe, GermanyLamprophyre
DS2003-0001
2003
Abdelrahman, E.Abdelrahman, E., El-Araby, T., Essa, K.A least square minimisation approach to depth, index parameter and amplitudeExploration Geophysics, (Australian Bulletin), Vol. 34, No. 4, Dec. pp. 241-248.GlobalBlank
DS0412-0001
2003
Abdelrahman, E.M.Abdelrahman, E.M., El Araby, T.M., Essa, K.S.A least squares minimisation approach to depth, index parameter, and amplitude coefficient determination from magnetic anomaliesExploration Geophysics, Vol. 34, pp. 241-248.TechnologyGeophysics - magnetics, dykes, ( not specific to diamon
DS0712-0001
2007
Abdelrahman, E.M.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
DS2002-0005
2002
Abdelrahman, E.S.M.Abdelrahman, E.S.M., El Araby, H.M., El Araby, T.M., Essa, K.S.A new approach to depth determination from magnetic anomaliesGeophysics, Vol. 67, 5, pp. 1524-31.GlobalGeophysics - magnetics not specific to diamonds
DS1994-0006
1994
Abdel-Rahman, A.F.M.Abdel-Rahman, A.F.M.Nature of biotites from alkaline, calc-alkaline and peraluminous magmasJournal of Petrology, Vol. 35, No. 2, April pp. 525-542GlobalMagmatism, Mineral chemistry -biotites
DS1994-0007
1994
Abdel-Rahman, A.F.M.Abdel-Rahman, A.F.M.Alkali amphibole: a potential source of rare earth elements in felsicalkaline rocks.Exploration and Mining Geology, Vol. 3, No. 2, April pp. 81-94.Quebec, Labrador, California, Nubian ShieldAlkaline rocks, Deposit -Oka
DS1712-2667
2018
Abdelsalam, G.Abdelsalam, G., Atekwana, E., Elsenbeck, J., Jones, A.G., Chikambwe, E.Imaging Precambrian lithospheric structure in Zambia using electromagnetic methods.Gondwana Research, Vol. 54, pp. 38-49.Africa, Zambia, Malawigeophysics

Abstract: The Precambrian geology of eastern Zambia and Malawi is highly complex due to multiple episodes of rifting and collision, particularly during the formation of Greater Gondwana as a product of the Neoproterozoic Pan-African Orogeny. The lithospheric structure and extent of known Precambrian tectonic entities of the region are poorly known as there have been to date few detailed geophysical studies to probe them. Herein, we present results from electromagnetic lithospheric imaging across Zambia into southern Malawi using the magnetotelluric method complemented by high-resolution aeromagnetic data of the upper crust in order to explore the extent and geometry of Precambrian structures in the region. We focus particularly on determining the extent of subcontinental lithospheric mantle (SCLM) beneath the Archean-Paleoproterozoic cratonic Bangweulu Block and the Mesoproterozoic-Neoproterozoic Irumide and Southern Irumide Orogenic Belts. We also focus on imaging the boundaries between these tectonic entities, particularly the boundary between the Irumide and Southern Irumide Belts. The thickest and most resistive lithosphere is found beneath the Bangweulu Block, as anticipated for stable cratonic lithosphere. Whereas the lithospheric thickness estimates beneath the Irumide Belt match those determined for other orogenic belts, the Southern Irumide Belt lithosphere is substantially thicker similar to that of the Bangweulu Block to the north. We interpret the thicker lithosphere beneath the Southern Irumide Belt as due to preservation of a cratonic nucleus (the pre-Mesoproterozoic Niassa Craton). A conductive mantle discontinuity is observed between the Irumide and Southern Irumide Belts directly beneath the Mwembeshi Shear Zone. We interpret this discontinuity as modified SCLM relating to a major suture zone. The lithospheric geometries determined from our study reveal tectonic features inferred from surficial studies and provide important details for the tectonothermal history of the region.
DS0412-1072
2003
Abdelsalam, M.Kusky, T.M., Abdelsalam, M., Tucker, R.D., Stern, R.J.Evolution of the East African and related orogens, and the assembly of Gondwana.Precambrian Research, Vol. 123, 2-4, pp. 81-85.Gondwana, East Africa, TanzaniaTectonics
DS2003-0763
2003
Abdelsalam, M.Kusky, T.M., Abdelsalam, M., Tucker, R.D., Stern, R.J.Evolution of the East African and related orogens, and the assembly of GondwanaPrecambrian Research, Vol. 123, 2-4, pp. 81-85.Gondwana, East Africa, TanzaniaBlank
DS1112-0001
2011
Abdelsalam, M.G.Abdelsalam, M.G., Gao, S.S., Liegeois, J-P.Upper mantle structure of the Sahara metacraton.Journal of African Earth Sciences, Vol. 60, 5, pp. 328-336.AfricaUpper mantle structure, convection
DS1212-0407
2013
Abdelsalam, M.G.Liegeois, J-P., Abdelsalam, M.G., Ennih, N., Ouabadi, A.Metacraton: nature, genesis and behaviour.Gondwana Research, Vol. 23, 1, pp. 220-237.TechnologySubduction
DS1705-0832
2017
Abdelsalam, M.G.Goussi Ngalamo, J.F., Bisso, D., Abdelsalam, M.G., Atekwana, E.A., Katumwehe, A.B., Ekodeck, G.E.Geophysical imaging of metacratonization in the northern edge of the Congo craton in Cameroon.Journal of African Earth Sciences, Vol. 129, pp. 94-107.Africa, CameroonCraton, Congo

Abstract: We used the World Gravity Map (WGM 2012) data to investigate the Archean Congo craton and the Oubanguides orogenic belt in Cameroon. The Oubanguides orogenic belt constitutes, from northwest to southeast, the Neoproterozoic West Cameroon domain, the Paleoproterozoic-Neoproterozoic Adamawa-Yade domain, and the dominantly Neoproterozoic Yaoundé domain (the crustal expression of the suture zone between the Congo craton and the orogenic terranes). We analyzed the WGM 2012 data to identify different gravity anomalies. We also applied the two-dimensional (2D) radially-averaged power spectral analysis to the WGM 2012 data to estimate the Moho depth. Additionally, we developed a 2D forward gravity model along a Nsbnd S profile to image the lithospheric structure of the Precambrian entities. We found that: (1) the Congo craton, the Yaoundé domain, the southeastern part of the West Cameroon domain, and the northern part of the Adamawa-Yade domain are characterized by low gravity anomaly. (2) the southern part of the Adamawa-Yade domain is marked by a pronounced E-W trending high gravity anomaly. (3) the crust is thicker beneath the Congo craton, the Yaoundé domain and the southern part of the Adamawa-Yade domain. (4) the presence of a denser lower crust material beneath the southern part of the Adamawa-Yade domain. We propose that this denser crustal material is an under-thrusted portion of the Congo craton that has been densified through metacratonization processes that accompanied collision between the craton and the orogenic terranes. This is in good agreement with geological and geochemical observations indicating that the northern edge of the Congo craton and the Adamawa-Yade domain had undergone metacratonization during the Neoproterozoic. Our suggestion is also in good agreement with observations which show that the margins of many cratons worldwide have been decratonized due to subduction processes. Our work highlights the importance of potential field geophysical data in mapping the metacratonized margins of cratons.
DS1801-0055
2018
Abdelsalam, M.G.Sarfian, E., Evans, R.L, Abdelsalam, M.G., Atekwana, E., Elsenbeck, J., Jones, A.G., Chikambwe, E..Imaging Precambrian lithospheric structure in Zambia using electromagnetic methods.Gondwana Research, Vol. 54, pp. 38-49.Africa, Zambiageophysics -em
DS1802-0263
2018
Abdelsalam, M.G.Sarafian, E., Evans, R.L., Abdelsalam, M.G., Atekwana, E., Elsenbeck, J., Jones, A.G., Chikambwe, E.Imaging Precambrian lithospheric structure in Zambia using electromagnetic methods.Gondwana Research, Vol. 54, pp. 38-49.Africa, Zambiageophysics

Abstract: The Precambrian geology of eastern Zambia and Malawi is highly complex due to multiple episodes of rifting and collision, particularly during the formation of Greater Gondwana as a product of the Neoproterozoic Pan-African Orogeny. The lithospheric structure and extent of known Precambrian tectonic entities of the region are poorly known as there have been to date few detailed geophysical studies to probe them. Herein, we present results from electromagnetic lithospheric imaging across Zambia into southern Malawi using the magnetotelluric method complemented by high-resolution aeromagnetic data of the upper crust in order to explore the extent and geometry of Precambrian structures in the region. We focus particularly on determining the extent of subcontinental lithospheric mantle (SCLM) beneath the Archean-Paleoproterozoic cratonic Bangweulu Block and the Mesoproterozoic-Neoproterozoic Irumide and Southern Irumide Orogenic Belts. We also focus on imaging the boundaries between these tectonic entities, particularly the boundary between the Irumide and Southern Irumide Belts. The thickest and most resistive lithosphere is found beneath the Bangweulu Block, as anticipated for stable cratonic lithosphere. Whereas the lithospheric thickness estimates beneath the Irumide Belt match those determined for other orogenic belts, the Southern Irumide Belt lithosphere is substantially thicker similar to that of the Bangweulu Block to the north. We interpret the thicker lithosphere beneath the Southern Irumide Belt as due to preservation of a cratonic nucleus (the pre-Mesoproterozoic Niassa Craton). A conductive mantle discontinuity is observed between the Irumide and Southern Irumide Belts directly beneath the Mwembeshi Shear Zone. We interpret this discontinuity as modified SCLM relating to a major suture zone. The lithospheric geometries determined from our study reveal tectonic features inferred from surficial studies and provide important details for the tectonothermal history of the region.
DS1809-2021
2018
Abdelsalam, M.G.Fletcher, A.W., Abdelsalam, M.G., Emishaw, L., Atekwana, E.A., Lao-Davila, D.A., Ismail, A.Lithospheric controls on the rifting of the Tanzanian Craton at the Eyasi Basin, eastern branch of the East African Rift system.Tectonics, Aug 14, doi: 10.1029/2018 TC005065Africa, Tanzaniacraton

Abstract: Continental rifts most often nucleate within orogenic belts. However, some studies in the East African Rift System (EARS) have shown that continental rifts can also develop withincratons. This work investigated the ~1.5 Ma Eyasibasin,which propagates in a WSW direction into the Tanzanian craton. The basin is located where the Eastern Branch of the EARS transitions from a narrow rift (~70 km wide) thewider(~300 km wide) North Tanzanian Divergence. Unlike the rest of the Eastern Branch segments, the Eyasibasindoes not follow the Mozambique orogenic belt located on the eastern margin of the Tanzanian craton. This work generatedlithospheric-scale sections across the basinusing: (1) Digital Elevation Model to map surface rift-related brittle structures; (2) Aeromagnetic data to determine the depth to the Precambrian basement;and (3) World Gravity Model 2012 to estimatecrustal and lithospheric thickness by applying the two-dimensional(2D) radially-averaged power spectral analysis and 2D forward gravity modeling. These cross-sectionsshow that the Eyasibasinnucleates within a previously unidentified suture zone within the Tanzanian cratonand that this suture zone is characterized by thinner lithospherethat can be as thin as ~95 km. This zone ofthinner lithosphere is offset southeastwardfrom the surface expression of the Eyasibasinand might have facilitated the formation of other basins further south. Furthermore, the lithospheric thickness map indicates that the Tanzanian craton is heterogeneous and possibly composed of multiplesmaller cratonic fragments.
DS1811-2595
2018
Abdelsalam, M.G.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.
DS1812-2812
2018
Abdelsalam, M.G.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.
DS1904-0733
2019
Abdelsalam, M.G.Evans, R.L., Elsenbeck, J., Zhu, J., Abdelsalam, M.G., Sarafian, E., Mutamina, D., Chilongola, F., Atekwana, E.A., Jones, A.G.Structure of the lithosphere beneath the Barotse basin, western Zambia, from magnetotelluric data.Tectonics, Vol. 38, 2, pp. 666-686.Africa, Zambiageophysics

Abstract: A magnetotelluric survey in the Barotse Basin of western Zambia shows clear evidence for thinned lithosphere beneath an orogenic belt. The uppermost asthenosphere, at a depth of 60-70 km, is highly conductive, suggestive of the presence of a small amount of partial melt, despite the fact that there is no surface expression of volcanism in the region. Although the data support the presence of thicker cratonic lithosphere to the southeast of the basin, the lithospheric thickness is not well resolved and models show variations ranging from ~80 to 150 km in this region. Similarly variable is the conductivity of the mantle beneath the basin and immediately beneath the cratonic lithosphere to the southeast, although the conductivity is required to be elevated compared to normal lithospheric mantle. In a general sense, two classes of model are compatible with the magnetotelluric data: one with a moderately conductive mantle and one with more elevated conductivities. This latter class would be consistent with the impingement of a stringer of plume-fed melt beneath the cratonic lithosphere, with the melt migrating upslope to thermally erode lithosphere beneath the orogenic belt that is overlain by the Barotse Basin. Such processes are potentially important for intraplate volcanism and also for development or propagation of rifting as lithosphere is thinned and weakened by melt. Both models show clear evidence for thinning of the lithosphere beneath the orogenic belt, consistent with elevated heat flow data in the region.
DS1996-0003
1996
Abdelsalam, M.G.Abdelsalam, M.G.Suture and shear zones in the Arabian Nubian shieldJournal of African Earth Sciences, Vol. 23, No. 3, Oct. 1, pp. 289-310Africa, Saudi Arabia, SudanTectonics, Arabian-Nubian shield
DS2002-0006
2002
Abdelsalam, M.G.Abdelsalam, M.G., Liegeois, J.P., Stern R.J.The Saharan metacratonJournal of African Earth Sciences, Vol.34, No.3-4,April-May pp. 119-36.AfricaTectonics, Craton
DS2000-0003
2000
Abdrahmanov, K.A.Abdrahmanov, K.A.New petrologic geodynamic model of diamond bearing magmatic formations And diamond deposit forecast.Igc 30th. Brasil, Aug. abstract only 1p.RussiaMagmatism - lamproite-kimberlite-picrite
DS1998-0003
1998
Abdrakhimov, M.Z.Abdrakhimov, M.Z., Kouznetsova, E.I.Development of intergranular cracking and relaxation of stress in deep crystalline rock of eartb crust ....7th International Kimberlite Conference Abstract, pp. 1-3.RussiaGeochemistry, Physico-chemical influence of water
DS1012-0358
2010
Abdu, Y.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
DS1412-0111
2014
Abdu, Y.Chakhmouradian, A.R., Cooper, M.A., Ball, N., Reguir, E.P., Medici, L., Abdu, Y., Antonov, A.A.Vladykinite Na3Sr4(Fe2+Fe3+)Si8O24: a new complex sheet silicate from peralkaline rocks of the Murun complex, eastern Siberia, Russia.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., pp. 5-21TechnologyAlkalic
DS1510-1761
2014
Abdu, Y.Chakhmouradian, A.R., Cooper, M.A., Ball, N., Reguir, E.P., Medici, L., Abdu, Y., Antonov, A.A.Vladykinite, Na3Sr4(Fe2+Fe3+)Si8024: a new complex sheet silicate from peralkaline rocks of the Murun Complex, eastern Siberia, Russia.Deep-seated magmatism, its sources and plumes, Proceedings of XIII International Workshop held 2014., Vol. 2014, pp. 5-21.Russia, SiberiaDeposit - Murun

Abstract: Vladykinite, ideally Na3Sr4(Fe2+Fe3+)Si8O24, is a new complex sheet silicate occurring as abundant prismatic crystals in a dike of coarse-grained peralkaline feldspathoid syenite in the north-central part of the Murun complex in eastern Siberia, Russia (Lat. 58° 22' 48? N; Long. 119° 03' 44? E). The new mineral is an early magmatic phase associated with aegirine, potassium feldspar, eudialyte, lamprophyllite, and nepheline; strontianite (as pseudomorphs after vladykinite) and K-rich vishnevite are found in the same assemblage, but represent products of late hydrothermal reworking. Vladykinite is brittle, has a Mohs hardness of 5, and distinct cleavage on {100}. In thin section, it is colorless, biaxial negative [a = 1.624(2), b = 1.652(2), g = 1.657(2), 2Vmeas = 44(1)°, 2Vcalc = 45(1)°] and shows an optic orientation consistent with its structural characteristics (X^a = 5.1° in b obtuse, Z^c = 4.7° in b acute, Y = b). The Raman spectrum of vladykinite consists of the following vibration modes (listed in order of decreasing intensity): 401, 203, 465, 991, 968, 915, 348, 167, 129, 264, 1039, and 681 cm–1; O-H signals were not detected. The Mössbauer spectrum indicates that both Fe2+ and Fe3+ are present in the mineral (Fe3+/FeS = 0.47), and that both cations occur in a tetrahedral coordination. The mean chemical composition of vladykinite (acquired by wavelength-dispersive X-ray spectrometry and laser-ablation inductively-coupled-plasma mass-spectrometry), with FeS recast into Fe2+ and Fe3+ in accord with the Mössbauer data, gives the following empirical formula calculated to 24 O atoms: (Na2.45Ca0.56)S3.01(Sr3.81 K0.04Ba0.02La0.02Ce0.01)S3.90(Fe2+0.75Fe3+0.66Mn0.26Zn0.16Al0.12Mg0.05Ti0.01)S2.01(Si7.81Al0.19)S8.00O24. The mineral is monoclinic, space group P21/c, a = 5.21381(13), b = 7.9143(2), c = 26.0888(7) Å, b = 90.3556(7)°, V = 1076.50(5) Å3, Z = 2. The ten strongest lines in the powder X-ray diffraction pattern are [dobs in Å (I) (hkl)]: 2.957 (100) (123, 123); 2.826 (100) (117, 117); 3.612 (58) (114, 114); 3.146 (37) (120); 2.470 (32) (210, 01.10); 4.290 (30) (111, 111); 3.339 (30) (106, 115, 106); 2.604 (28) (200); 2.437 (25) (034); 1.785 (25) (21.10, 234). The structure of vladykinite, refined by single-crystal techniques on the basis of 3032 reflections with Fo > 4sFo to R1 = 1.6%, consists of tetrahedral sheets parallel to (100) and consisting of (Si8O24)16– units incorporating four-membered silicate rings and joined into five- and eight-membered rings by sharing vertices with larger tetrahedra hosting Fe2+, Fe3+, Mn, Zn, Al, Mg, and Ti. Larger cations (predominantly Na, Sr, and Ca) are accommodated in octahedral and square-antiprismatic interlayer sites sandwiched between the tetrahedral sheets. Structural relations between vladykinite and other sheet silicates incorporating four-, five-, and eight-membered rings are discussed. The name vladykinite is in honor of Nikolay V. Vladykin (Vinogradov Institute of Geochemistry, Russia), in recognition of his contribution to the study of alkaline rocks. Holotype and co-type specimens of the mineral were deposited in the Robert B. Ferguson Museum of Mineralogy in Winnipeg, Canada.
DS1602-0241
2015
Abdu, Y.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, a 103.174(2), ß 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 > 4sF) reflections collected with a single-crystal APEX II ULTRA three-circle diffractometer with a rotating-anode generator (MoKa), multilayer optics, and an APEX-II 4K CCD detector. Electron-microprobe analysis gave the empirical formula (Na5.39Ca0.36Mn0.04Mg0.01)S5.80 (Ti2.77Nb0.48Mg0.29Fe3+0.23Mn0.20Zr0.02Ta0.01)S4(Si2.06O7)2[P1.98O5(OH)3]O2[O0.82F0.65(OH)0.53]S2, 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.
DS1412-0091
2014
Abdu, Y.A.Camara, F., Skolova, E., Abdu, Y.A., Hawthorne, F.C.Nafertisite Na3Fe2 10Ti2(Si6017)02(OH)6F(H2))2 from Mt. Kukisvumchorr Khibiny alkaline massif, Kola Peninsula, Russia: refinement of the crystal structure and revision of the chemical formula.European Journal of Mineralogy, Vol. 26, pp. 689-700.Russia, Kola PeninsulaKhibiniy Massif
DS1512-1903
2015
Abdu, Y.A.Chakhmouradian, A.R., Cooper, M.A., Medici, L., Abdu, Y.A., Shelukhina, Y.S.Anzaite-(Ce), a new rare earth mineral and structure type from the AfrikAnd a silicocarbonatite, Kola Peninsula.Mineralogical Magazine, Vol. 79, 5, pp. 1231-1244.RussiaCarbonatite

Abstract: Anzaite-(Ce), ideally Formula Fe2+Ti6O18(OH)2, is a new, structurally complex mineral occurring as scarce minute crystals in hydrothermally altered silicocarbonatites in the Afrikanda alkali-ultramafic complex of the Kola Peninsula, Russia. The mineral is a late hydrothermal phase associated with titanite, hibschite, clinochlore and calcite replacing the primary magmatic paragenesis. The rare-earth elements (REE) (dominated by Ce), Ti and Fe incorporated in anzaite-(Ce) were derived from primary Ti oxides abundant in the host rock. Anzaite-(Ce) is brittle and lacks cleavage; the density calculated on the basis of structural data is 5.054(6) g cm-3. The mineral is opaque and grey with a bluish hue in reflected light; its reflectance values range from 15-16% at 440 nm to 13-14% at 700 nm. Its infrared spectrum shows a prominent absorption band at 3475 cm-1 indicative of OH- groups. The average chemical composition of anzaite-(Ce) gives the following empirical formula calculated on the basis of 18 oxygen atoms and two OH- groups: (Ce2.18Nd0.85La0.41Pr0.26Sm0.08Ca0.36Th0.01)S4.15Fe0.97(Ti5.68Nb0.22Si0.04)S5.94O18(OH)2. The mineral is monoclinic, space group C2/m, a = 5.290(2), b = 14.575(6), c = 5.234(2) Å, ß = 97.233(7)°, V = 400.4(5) Å3, Z = 1. The ten strongest lines in the X-ray micro-diffraction pattern are [dobs in Å (I) hkl]: 2.596 (100) 002; 1.935 (18) 170; 1.506 (14) 133; 1.286 (13) 1.11.0; 2.046 (12) 2I41; 1.730 (12) 003; 1.272 (12) 0.10.2; 3.814 (11) 1I11; 2.206 (9) 061; 1.518 (9) 172. The structure of anzaite-(Ce), refined by single-crystal techniques to R1 = 2.1%, consists of alternating layers of type 1, populated by REE (+ minor Ca) in a square antiprismatic coordination and octahedrally coordinated Fe2+, and type 2, built of five-coordinate and octahedral Ti, stacked parallel to (001). This atomic arrangement is complicated by significant disorder affecting the Fe2+, five-coordinate Ti and two of the four anion sites. The order-disorder pattern is such that only one half of these positions in total occupy any given (010) plane, and the disordered (010) planes are separated by ordered domains comprising REE, octahedral Ti and two anion sites occupied by O2-. Structural and stoichiometric relations between anzaite-(Ce) and other REE-Ti (±Nb, Ta) oxides are discussed. The name anzaite-(Ce) is in honour of Anatoly N. Zaitsev of St Petersburg State University (Russia) and The Natural History Museum (UK), in recognition of his contribution to the study of carbonatites and REE minerals. The modifier reflects the prevalence of Ce over other REE in the composition of the new mineral.
DS0812-0574
2008
Abduriyim, A.Kitawaki, H., Abduriyim, A., Okano, M.Identification of melee size synthetic yellow diamonds in jewelry.Gems & Gemology, Vol. 44, 3, pp. 202-213.TechnologySynthetics
DS2001-0039
2001
Abe, M.Arai, S., Kida, M., Abe, M., Yurimoto, H.Petrology of peridotite xenoliths in alkali basalt ( 11 Ma) from Boun, Korea: insight into upper mantle....Journal of Min. Petrol. Sciences, Vol. 96, No. 3, pp. 89-99.GlobalMantle mineralogy - East Asian continental margin
DS0412-0723
2003
Abe, N.Griffin, W.L., O'Reilly, S.Y., Abe, N., Aulbach, S., Davies, R.M., Pearson, N.J., Doyle, B.J.,Kivi, K.The origin and evolution of Archean lithospheric mantle.Precambrian Research, Vol. 127, 1-2, Nov. pp. 19-41.China, Africa, Russia, Canada, Northwest TerritoriesGeochemistry, SCLM, continental, Archon, metasomatism
DS0712-0023
2007
Abe, N.Arai, S., Abe, N., Ishimaru, S.Mantle peridotites from the Western Pacific.Gondwana Research, Vol. 11, 1-2, Jan. pp. 180-199.AsiaPeridotite
DS1701-0027
2016
Abe, N.Pilet, S., Abe, N., Rochat, L., Kaczmarek, M-A., Hirano. N., Machida, S., Buchs, D.M., Baumgartner, P.O., Muntener, O.Pre-subduction metasomatic enrichment of the oceanic lithosphere induced by plate flexure.Nature Geoscience, Vol. 9, pp. 898-903.MantleSubduction

Abstract: Oceanic lithospheric mantle is generally interpreted as depleted mantle residue after mid-ocean ridge basalt extraction. Several models have suggested that metasomatic processes can refertilize portions of the lithospheric mantle before subduction. Here, we report mantle xenocrysts and xenoliths in petit-spot lavas that provide direct evidence that the lower oceanic lithosphere is affected by metasomatic processes. We find a chemical similarity between clinopyroxene observed in petit-spot mantle xenoliths and clinopyroxene from melt-metasomatized garnet or spinel peridotites, which are sampled by kimberlites and intracontinental basalts respectively. We suggest that extensional stresses in oceanic lithosphere, such as plate bending in front of subduction zones, allow low-degree melts from the seismic low-velocity zone to percolate, interact and weaken the oceanic lithospheric mantle. Thus, metasomatism is not limited to mantle upwelling zones such as mid-ocean ridges or mantle plumes, but could be initiated by tectonic processes. Since plate flexure is a global mechanism in subduction zones, a significant portion of oceanic lithospheric mantle is likely to be metasomatized. Recycling of metasomatic domains into the convecting mantle is fundamental to understanding the generation of small-scale mantle isotopic and volatile heterogeneities sampled by oceanic island and mid-ocean ridge basalts.
DS1995-0054
1995
Abe, N.Arai, S., Abe, N.Reaction of orthopyroxene in peridotite xenoliths with alkali-basalt melt and its implication for alpine crAmerican Mineralogist, Vol. 80, No. 9-10, Sept, Oct pp. 1041-1047.JapanXenoliths
DS1998-0004
1998
Abe, N.Abe, N., Arai, S., Yurimoto, H.Petrology of the arc peridotite xenoliths: implications for geochemical evolution of the wedge mantle.7th International Kimberlite Conference Abstract, pp. 4-6.MantleXenoliths, Subduction
DS2000-0004
2000
Abe, N.Abe, N., Arai, S., Shcheka, S., Yurimoto, H.Petrology of harzburgite and related xenoliths from Avacha volcano, Kamchatka Arc and its implication for..Igc 30th. Brasil, Aug. abstract only 1p.RussiaMantle - wedge mantle processes, Xenoliths
DS2001-0001
2001
Abe, N.Abe, N.Petrochemistry of serpentinized peridotite from the Iberia abyssal plain: its character intermediate ....Geological Society of London Special Publication, No. 187, pp. 143-60.MantleMantle - upper, sub-oceanic - sub-continental
DS2003-0502
2003
Abe, N.Griffin, W.L., O'Reilly, S.Y., Abe, N., Aulbach, S., Davies, R.M., Pearson, N.J.The origin and evolution of Archean lithospheric mantlePrecambrian Research, Vol. 127, 1-2, Nov. pp. 19-41.China, South Africa, Siberia, Northwest Territories, BoGeochemistry, SCLM, continental, Archon, metasomatism
DS1993-0005
1993
Abe, Y.Abe, Y.Physical state of the very early earthLithos, Vol. 30, No. 3-4, Septtember pp. 223-236MantleGeodynamics
DS1012-0276
2010
Abedu, B.Hetman, C.M., Nowicki, T., Freeman, L., Abedu, B.The preliminary geology and evaluation of the Koidu kimberlite dykes, Sierra Leone.International Dyke Conference Held Feb. 6, India, 1p. AbstractAfrica, Sierra LeoneDyke morphology
DS1212-0298
2012
Abedu, B.Hetman, C.M., Freeman, L., Nowicki, T.E., Abedu, B.Internal geology development and emplacement of the K1 kimberlite pipe, Koidu mine, Sierra Leone, West Africa.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractAfrica, Sierra LeoneDeposit - Koidu
DS1212-0493
2012
Abedu, B.Moss, S., Nowicki, T., Hetman, C., Freeman, L.,Abedu, B.Geology and evaluation of kimberlite dykes at Koidu, Sierra Leone.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractAfrica, Sierra LeoneDeposit - Koidu
DS1412-0339
2013
Abedu, B.Harder, M., Nowicki, T.E., Hetman, C.M., Freeman, L., Abedu, B.Geology and exploration of the K2 kimberlite, Koidu mine, Sierra Leone, West Africa.Proceedings of the 10th. International Kimberlite Conference, Vol. 2, pp. 191-208.Africa, Sierra LeoneDeposit - Koidu (K2)
DS1212-0284
2012
Abedub, B.Harder, M.C., Nowickia, C., Hetman, T.E., Hetmana, D., Freeman, C.M., Abedub, B.Geology and evaluation of the K2 kimberlite, Koidu mine, Sierra Leone, West Africa.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractAfrica, Sierra LeoneDeposit - K2 Koidu
DS0412-0345
2003
Abello, J.Collins, A.S., Johnson, S., Fitzimmona, I.C.W., Powell, C.McA., Hulscher, B., Abello, J., Razakamana, T.Neoproterozoic deformation in central Madagascar: a structural section through part of the East African orogen.Proterozoic East Gondwana: Supercontinent assembly and Breakup. Ed. Yoshida , Geological Society of London Spe, No. 206, pp. 363-380.Africa, MadagascarPlume, tectonics
DS1903-0507
2019
Abelsalam, M.G.Evans, R.L., Elsenbeck, J., Zhu, J., Abelsalam, M.G., Sarafian, E., Mutamina, D., Chilongola, F., Atekwan, E., Jones, A.G.Structure of the lithosphere beneath the Barotse Basin, western Zambia from magnetotelluric data.Tectonics, in press available Africa, Zambiamelting

Abstract: A magnetotelluric survey in the Barotse Basin of western Zambia shows clear evidence for thinned lithosphere beneath an orogenic belt. The uppermost asthenosphere, at a depth of 60-70 km, is highly conductive, suggestive of the presence of a small amount of partial melt, despite the fact that there is no surface expression of volcanism in the region. Although the data support the presence of thicker cratonic lithosphere to the southeast of the basin, the lithospheric thickness is not well resolved and models show variations ranging from ~80 to 150 km in this region. Similarly variable is the conductivity of the mantle beneath the basin and immediately beneath the cratonic lithosphere to the southeast, although the conductivity is required to be elevated compared to normal lithospheric mantle. In a general sense, two classes of model are compatible with the magnetotelluric data: one with a moderately conductive mantle and one with more elevated conductivities. This latter class would be consistent with the impingement of a stringer of plume-fed melt beneath the cratonic lithosphere, with the melt migrating upslope to thermally erode lithosphere beneath the orogenic belt that is overlain by the Barotse Basin. Such processes are potentially important for intraplate volcanism and also for development or propagation of rifting as lithosphere is thinned and weakened by melt. Both models show clear evidence for thinning of the lithosphere beneath the orogenic belt, consistent with elevated heat flow data in the region.
DS1992-0003
1992
Aber, J.S.Aber, J.S.The glaciation of northeastern KansasBoreas, Vol. 20, No. 4, December 1st. pp. 297-314KansasGeomorphology, Glacial
DS1993-0006
1993
Aber, J.S.Aber, J.S.Glaciotectonics and mapping glacial depositsCanadian Press Research Center, University of Regina, Saskatchewan S4S O42 Payable, 310p. $ 78.00 plus GST etcGlobalGlacial deposits, Geomorphology
DS1993-0007
1993
Aber, J.S.Aber, J.S.Proceedings and field guide of the Inqua Commision on formation and properties of glacial depositsCanadian Plains Research Center, University of Regina, Regina, 310p. approx. $ 75.00Russia, Saskatchewan, GlobalGeomorphology, glacial deposits, Table of contents
DS1995-0004
1995
Aber, J.S.Aber, J.S., Bluemle, J.P., Brighton-Grette, J., et al.Glaciotectonic map of North AmericaGeological Society of America (GSA) Map, No. MCHO79, 1: 6, 500, 000 $ 21.00Canada, United StatesMap, Glaciology, glacial, structures
DS2001-0002
2001
Aber, J.S.Aber, J.S., Aber, S.W.Limestone xenoliths in Hills Pond lamproite, Woodson County, KansasKansas Academy of Science, Vol. 104, No. 1/2, pp. 123-28.KansasLamproite, Deposit - Hills Pond
DS2001-0002
2001
Aber, S.W.Aber, J.S., Aber, S.W.Limestone xenoliths in Hills Pond lamproite, Woodson County, KansasKansas Academy of Science, Vol. 104, No. 1/2, pp. 123-28.KansasLamproite, Deposit - Hills Pond
DS1998-1146
1998
AbercrombiePeirce, J.W., Goussev, Charters, Abercrombie, De PaoliIntrasedimentary magnetization by vertical fluid flow and exotic geochemistry.Leading Edge, Vol. 17, No. 1, pp. 89-92.Alberta, Western CanadaGeophysics - magnetics, Basin
DS1999-0019
1999
AbercrombieArden, K.M., DePaoli, Johnson, Hemstock, AbercrombieMetallic and industrial mineral assessment report on the Athabasca permitsin northeastern Alberta.Alberta Geological Survey, MIN 19990004AlbertaExploration - assessment, Birch Mountain Resources Ltd.
DS1998-0005
1998
Abercrombie, H.Abercrombie, H.Metallic and industrial mineral assessment report on the precious and base metals in northeast Alberta.Alberta Geological Survey, MIN 19980001Alberta, northeastExploration - assessment, Birch Mountain Resources Ltd.
DS1860-0575
1888
Abercromby, R.Abercromby, R.Seas and Skies in Many Latitudes; Or, Wanderings in Search Of Weather.London: E. Stanford., 447P.Africa, South AfricaTravelogue
DS1985-0501
1985
Aberg, G.Nystrom, J.O., Svensson, N.B., Aberg, G.An occurrence of apatite rich rocks of carbonatitic affinity near the Jotnian graben structure in Gavle, central SwedenGeol. Forens, Vol. 107, No. 3, pp. 185-195Sweden, ScandinaviaCarbonatite
DS1709-1975
2017
Abernethy, F.Crosby, J., Mikhail, S., Stuart, F., Abernethy, F.Tracing volatiles in Earth's mantle using He-C-N isotopes in garnet bearing diamondites.Goldschmidt Conference, abstract 1p.Mantlediamondites

Abstract: The origin of diamond-forming carbon in the Earth is unclear [1-3]; sources include subducted organic sediment and primordial mantle carbon. For example, some diamonds contain eclogitic silicate + sufide inclusions and have depleted ?13C (-10 to -30‰), enriched ?15N (+3 to +35‰) values, consistent with subducted crustal material [2-3]. However, some diamonds show mantle-like ?15N (<-5‰) and depleted ?13C values (-10 to -30‰ ) which have been cited as evidence of enstatite chondrite-like primordial C-N sources [1]. The helium isotope composition of mantle rocks are powerful tracers,of Earth’s volatile history because primordial 3He is not recycled back into the mantle. However, there are few He isotope studies of diamond fluids. The 3He/4He of garnetbearing diamondites from the Orapa mine (Botswana) range from 0.1 to 3 Ra [4-5], consistent with a recycled origin. However, our recent work has identified a suite of diamondites with 3He/4He = 0.06 to 8.2 Ra which correlates negatively with ?13C, suggesting that the subduction-related C is associated with mantle 3He/4He ratios. To unravel this complexity we are combining He, C and N isotope analyses in polycrystalline diamond from garnetbearing diamondites from the Orapa mine. These data will also be used to assess the extent to which carbon and nitrogen isotopes are decoupled during diamond-formation [3].
DS0512-0001
2005
Abers, G.A.Abers, G.A.Seismic low velocity layer at the top of subducting slabs: observations, predictions, and systematics.Physics of the Earth and Planetary Interiors, Vol. 149, 1-2, March 15, pp. 7-29.MantleSubduction
DS0612-1402
2006
Abers, G.A.Syracuse, E.M., Abers, G.A.Global compilation of variations in slab depth beneath arc volcanoes and implications.Geochemical, Geophysics, Geosystems: G3, Vol. 7, 5, May 23, 18p.MantleSlab geometry, thickness, dip - not specific to diamond
DS1112-1076
2011
Abers, G.A.Van Keken, P.E., Hacker, B.R., Syracuse, E.M.,Abers, G.A.Subduction factory: 4. Depth dependent flux of H2O from subducting slabs worldwide.Journal of Geophysical Research, Vol. 116, B01401.MantleSubduction
DS1212-0277
2012
Abers, G.A.Hacker, B.R., Abers, G.A.Subduction factory 5: Unusually low Poisson's ratios in subduction zones from elastic anisotropy of peridotite.Journal of Geophysical Research, Vol. 117, B6, B06308.MantleSubduction
DS1707-1298
2017
Abers, G.A.Abers, G.A., van Keken, P.E., Hacker, B.R.The cold and relatively dry nature of mantle forearcs in subduction zones.Nature Geoscience, Vol. 10, pp. 333-337.Mantlesubduction

Abstract: Some of Earth's coldest mantle is found in subduction zones at the tip of the mantle wedge that lies between the subducting and overriding plates. This forearc mantle is isolated from the flow of hot material beneath the volcanic arc, and so is inferred to reach temperatures no more than 600 to 800 °C - conditions at which hydrous mantle minerals should be stable. The forearc mantle could therefore constitute a significant reservoir for water if sufficient water is released from the subducting slab into the mantle wedge. Such a reservoir could hydrate the plate interface and has been invoked to aid the genesis of megathrust earthquakes and slow slip events. Our synthesis of results from thermal models that simulate the conditions for subduction zones globally, however, indicates that dehydration of subducting plates is too slow over the life span of a typical subduction zone to hydrate the forearc mantle. Hot subduction zones, where slabs dehydrate rapidly, are an exception. The hottest, most buoyant forearcs are most likely to survive plate collisions and be exhumed to the surface, so probably dominate the metamorphic rock record. Analysis of global seismic data confirms the generally dry nature of mantle forearcs. We conclude that many subduction zones probably liberate insufficient water to hydrate the shallower plate boundary where great earthquakes and slow slip events nucleate. Thus, we suggest that it is solid-state processes and not hydration that leads to weakening of the plate interface in cold subduction zones.
DS1999-0625
1999
Abers, G.A.Sarker, G., Abers, G.A.Lithospheric temperature estimates from seismic attentuation across range fronts in southern and central.Geology, Vol. 27, No. 5, May pp. 427-30.GlobalCraton, Tian Shan Mountains
DS0412-1914
2004
Abers, G.C.Stachnik, J.C., Abers, G.C., Christensen, D.H.Seismic attenuation and mantle wedge temperatures in the Alaska subduction zone.Journal of Geophysical Research, Vol. 109, B10, B10405 10.1029/2004 JBO3018United States, AlaskaGeophysics - seismics, geothermometry
DS1610-1838
2016
Abersteiner, A.Abersteiner, A., Giuliani, A., Kamenetsky, V.S., Phillips, D.Petrographic and melt inclusion constraints on the petrogenesis of a magmaclast from the Venetia kimberlite cluster, South Africa.Chemical Geology, in press available 11p.Africa, South AfricaDeposit - Venetia

Abstract: Kimberlitic magmaclasts are discrete ovoid magmatic fragments that formed prior to emplacement from disrupted kimberlite magma. To provide new constraints on the origin and evolution of the kimberlite melts, we document the mineralogy and petrography of a magmaclast recovered from one of the ca. 520 Ma Venetia kimberlites, South Africa. The sample (BI9883) has a sub-spherical shape and consists of a ~ 10 mm diameter central olivine macrocryst, surrounded by porphyritic kimberlite. The kimberlitic material consists of concentrically aligned, altered olivine phenocrysts, set in a crystalline groundmass of calcite, chromite, perovskite, phlogopite, apatite, ilmenite, titanite, sulphides, rutile and magnetite along with abundant alteration phases (i.e. serpentine, talc and secondary calcite). These features are typical of archetypal hypabyssal kimberlites. We examined primary fluid/melt inclusions in chromite, perovskite and apatite containing a diversity of daughter phases. Chromite and perovskite host polycrystalline inclusions containing abundant alkali-carbonates (i.e. enriched in K, Na, Ba, Sr), phosphates, Na-K chlorides, sulphides and equal to lesser quantities of olivine, phlogopite and pleonaste. In contrast, apatite hosts polycrystalline assemblages with abundant alkali-carbonates and Na-K chlorides and lesser amounts of olivine, monticellite and phlogopite. Numerous solid inclusions of shortite (Na2Ca2(CO3)3), Na-Sr-carbonates and apatite occur in groundmass calcite along with fluid inclusions containing daughter crystals of Na-carbonates and Na-chlorides. The primary inclusions in chromite, perovskite and apatite are considered to represent remnants of fluid(s)/melt(s) trapped during crystallisation of the host minerals, whereas the fluid inclusions in calcite are probably secondary in origin. The component proportions of these primary fluid/melt inclusions were estimated in an effort to constrain the composition of the evolving kimberlite melt. These estimates suggest melt evolution from a silicate-carbonate kimberlite melt that became increasingly enriched in carbonates, phosphates, alkalis and chlorides, in response to the fractional crystallisation of constituent minerals (i.e. olivine to apatite). The concentric alignment of crystals around the olivine kernel and ovoid shape of the magmaclast can be ascribed to the low viscosity of the kimberlite melt and rapid rotation whilst in a liquid or partial crystalline state, or to progressive layer-by-layer growth of the magmaclast. Although the mineralogy of our sample is similar to hypabyssal kimberlites worldwide, it differs from hypabyssal kimberlite units in the main Venetia pipes, which contain monticellite-phlogopite rich assemblages and segregationary matrix textures. Therefore magmaclast BI9883 probably originated from a batch of magma distinct from those that produced known hypabyssal units within the Venetia kimberlite cluster.-
DS1707-1299
2017
Abersteiner, A.Abersteiner, A., Giuliani, A., Kamenetsky, V.S., Phillips, D.Petrographic and melt inclusion constraints on the petrogenesis of a magmaclast from the Venetia kimberlite cluster, South Africa.Chemical Geology, Vol. 455, pp. 331-341.Africa, South Africadeposit - Venetia

Abstract: Kimberlitic magmaclasts are discrete ovoid magmatic fragments that formed prior to emplacement from disrupted kimberlite magma. To provide new constraints on the origin and evolution of the kimberlite melts, we document the mineralogy and petrography of a magmaclast recovered from one of the ca. 520 Ma Venetia kimberlites, South Africa. The sample (BI9883) has a sub-spherical shape and consists of a ~ 10 mm diameter central olivine macrocryst, surrounded by porphyritic kimberlite. The kimberlitic material consists of concentrically aligned, altered olivine phenocrysts, set in a crystalline groundmass of calcite, chromite, perovskite, phlogopite, apatite, ilmenite, titanite, sulphides, rutile and magnetite along with abundant alteration phases (i.e. serpentine, talc and secondary calcite). These features are typical of archetypal hypabyssal kimberlites. We examined primary fluid/melt inclusions in chromite, perovskite and apatite containing a diversity of daughter phases. Chromite and perovskite host polycrystalline inclusions containing abundant alkali-carbonates (i.e. enriched in K, Na, Ba, Sr), phosphates, Na-K chlorides, sulphides and equal to lesser quantities of olivine, phlogopite and pleonaste. In contrast, apatite hosts polycrystalline assemblages with abundant alkali-carbonates and Na-K chlorides and lesser amounts of olivine, monticellite and phlogopite. Numerous solid inclusions of shortite (Na2Ca2(CO3)3), Na-Sr-carbonates and apatite occur in groundmass calcite along with fluid inclusions containing daughter crystals of Na-carbonates and Na-chlorides. The primary inclusions in chromite, perovskite and apatite are considered to represent remnants of fluid(s)/melt(s) trapped during crystallisation of the host minerals, whereas the fluid inclusions in calcite are probably secondary in origin. The component proportions of these primary fluid/melt inclusions were estimated in an effort to constrain the composition of the evolving kimberlite melt. These estimates suggest melt evolution from a silicate-carbonate kimberlite melt that became increasingly enriched in carbonates, phosphates, alkalis and chlorides, in response to the fractional crystallisation of constituent minerals (i.e. olivine to apatite). The concentric alignment of crystals around the olivine kernel and ovoid shape of the magmaclast can be ascribed to the low viscosity of the kimberlite melt and rapid rotation whilst in a liquid or partial crystalline state, or to progressive layer-by-layer growth of the magmaclast. Although the mineralogy of our sample is similar to hypabyssal kimberlites worldwide, it differs from hypabyssal kimberlite units in the main Venetia pipes, which contain monticellite-phlogopite rich assemblages and segregationary matrix textures. Therefore magmaclast BI9883 probably originated from a batch of magma distinct from those that produced known hypabyssal units within the Venetia kimberlite cluster.
DS1708-1563
2017
Abersteiner, A.Abersteiner, A., Kamanetsky, V.S., Kamenetsky, M., Goemann, K., Ehrig, K., Rodemann, T.Significance of halogens ( F, Cl) in kimberlite melts: insights from mineralogy and melt inclusions in the Roger pipe ( Ekati, Canada).Chemical Geology, in press available, 16p.Canada, Northwest Territoriesdeposit, Roger, Ekati

Abstract: The abundance and distribution of halogens (F, Cl) are rarely recorded in kimberlites and therefore their petrogenetic significance is poorly constrained. Halogens are usually present in kimberlite rocks in the structure of phlogopite and apatite, but their original concentrations are never fully retained due to the effects of alteration. To provide new constraints on the origin and evolution of halogens in kimberlites and their melts, we present a detailed study of the petrography and geochemistry of the late-Cretaceous Group-I (or archetypal) Roger kimberlite (Ekati cluster, Canada). The studied samples contain abundant anhedral-to-euhedral olivine which is set in a crystalline groundmass of monticellite, phlogopite, apatite, spinel (i.e. magnesian ulvöspinel-magnetite (MUM), Mg-magnetite, pleonaste, Cr-spinel), and perovskite along with abundant secondary alteration phases (i.e. serpentine, garnet (andradite-schlorlomite), amakinite ((Fe2 +, Mg, Mn)(OH)2), calcite). The Roger kimberlite is characterised by the highest recorded F-content (up to 2688 ppm) of the Ekati cluster kimberlites, which is reflected by the preservation of F-rich phases, where bultfonteinite (Ca4(Si2O7)(F, OH)2) and fluorite commonly replace olivine. In order to examine the composition and evolution of the kimberlite melt prior to post-magmatic processes, we studied melt inclusions in olivine, Cr-spinel, monticellite and apatite. Primary multiphase melt inclusions in Cr-spinel, monticellite and apatite and secondary inclusions in olivine are shown to contain a diversity of daughter phases and compositions that are dominated by alkali/alkali-earth (Na, K, Ba, Sr)-enriched Ca-Mg-carbonates ± F, Na-K-chlorides and sulphates, phosphates ± REE, spinel, silicates (e.g. olivine, phlogopite, (clino)humite), and sulphides. Although alkali/alkali-earth- and halogen-bearing phases are abundant in melt inclusions, they are generally absent from the kimberlite groundmass, most likely due to ubiquitous effects of syn- and/or post-magmatic alteration (i.e. serpentinisation). Comparisons between halogens and other trace elements of similar compatibility (i.e. F/Nd and Cl/U) in the Roger kimberlite and their respective estimated primitive mantle abundances show that halogens should be a more significant component in kimberlites than typically measured. We propose that fluorine in the Roger kimberlite was magmatic and was redistributed during hydrothermal alteration by Ca-bearing serpentinising fluids to produce the observed bultfonteinite/fluorite assemblages. Based the compositions and daughter mineral assemblages in primary melt inclusions and reconstructed halogen abundances, we suggest that Cr-spinel, monticellite and apatite crystallised from a variably differentiated Si-P-Cl-F-bearing carbonate melt that was enriched in alkalis/alkali-earths and highly incompatible trace elements
DS1708-1564
2017
Abersteiner, A.Abersteiner, A., Kamanetsky, V.S., Pearson, D.G., Kamenetsky, M., Ehrig, K., Goemann, K., Rodemann, T.Monticellite in group I kimberlites: implications for evolution of parallel melts and post emplacement CO2 degassing. Leslie, Pipe 1Chemical Geology, in press available, 54p.Canada, Northwest Territories, Europe, Finlanddeposit, Leslie

Abstract: Monticellite is a magmatic and/or deuteric mineral that is often present, but widely varying in concentrations in Group-I (or archetypal) kimberlites. To provide new constraints on the petrogenesis of monticellite and its potential significance to kimberlite melt evolution, we examine the petrography and geochemistry of the minimally altered hypabyssal monticellite-rich Leslie (Canada) and Pipe 1 (Finland) kimberlites. In these kimberlites, monticellite (Mtc) is abundant (25–45 vol%) and can be classified into two distinct morphological types: discrete and intergrown groundmass grains (Mtc-I), and replacement of olivine (Mtc-II). Monticellite in group-I kimberlites: Implications for evolution of parental melts and post-emplacement CO 2 degassing (PDF Download Available).
DS1708-1588
2017
Abersteiner, A.Abersteiner, A.Significance of halogens ( F, Cl) in kimberlite melts: insights from mineralogy and melt inclusions in the Roger pipe ( Ekati, Canada).11th. International Kimberlite Conference, PosterCanada, Northwest Territoriesdeposit - Roger

Abstract: The abundance and distribution of halogens (F, Cl) are rarely recorded in kimberlites and therefore their petrogenetic significance is poorly constrained. Halogens are usually present in kimberlite rocks in the structure of phlogopite and apatite, but their original concentrations are never fully retained due to the effects of alteration. To provide new constraints on the origin and evolution of halogens in kimberlites and their melts, we present a detailed study of the petrography and geochemistry of the late-Cretaceous Group-I (or archetypal) Roger kimberlite (Ekati cluster, Canada). The studied samples contain abundant anhedral-to-euhedral olivine which is set in a crystalline groundmass of monticellite, phlogopite, apatite, spinel (i.e. magnesian ulvöspinel-magnetite (MUM), Mg-magnetite, pleonaste, Cr-spinel), and perovskite along with abundant secondary alteration phases (i.e. serpentine, garnet (andradite-schlorlomite), amakinite ((Fe2 +, Mg, Mn)(OH)2), calcite). The Roger kimberlite is characterised by the highest recorded F-content (up to 2688 ppm) of the Ekati cluster kimberlites, which is reflected by the preservation of F-rich phases, where bultfonteinite (Ca4(Si2O7)(F, OH)2) and fluorite commonly replace olivine. In order to examine the composition and evolution of the kimberlite melt prior to post-magmatic processes, we studied melt inclusions in olivine, Cr-spinel, monticellite and apatite. Primary multiphase melt inclusions in Cr-spinel, monticellite and apatite and secondary inclusions in olivine are shown to contain a diversity of daughter phases and compositions that are dominated by alkali/alkali-earth (Na, K, Ba, Sr)-enriched Ca-Mg-carbonates ± F, Na-K-chlorides and sulphates, phosphates ± REE, spinel, silicates (e.g. olivine, phlogopite, (clino)humite), and sulphides. Although alkali/alkali-earth- and halogen-bearing phases are abundant in melt inclusions, they are generally absent from the kimberlite groundmass, most likely due to ubiquitous effects of syn- and/or post-magmatic alteration (i.e. serpentinisation). Comparisons between halogens and other trace elements of similar compatibility (i.e. F/Nd and Cl/U) in the Roger kimberlite and their respective estimated primitive mantle abundances show that halogens should be a more significant component in kimberlites than typically measured. We propose that fluorine in the Roger kimberlite was magmatic and was redistributed during hydrothermal alteration by Ca-bearing serpentinising fluids to produce the observed bultfonteinite/fluorite assemblages. Based the compositions and daughter mineral assemblages in primary melt inclusions and reconstructed halogen abundances, we suggest that Cr-spinel, monticellite and apatite crystallised from a variably differentiated Si-P-Cl-F-bearing carbonate melt that was enriched in alkalis/alkali-earths and highly incompatible trace elements.
DS1708-1589
2017
Abersteiner, A.Abersteiner, A.Monticellite in Group 1 kimberlites: implications for evolution of partial melts and post-emplacement CO2 degassing.11th. International Kimberlite Conference, PosterTechnologymonticellite

Abstract: Monticellite is a magmatic and/or deuteric mineral that is often present, but widely varying in concentrations in Group-I (or archetypal) kimberlites. To provide new constraints on the petrogenesis of monticellite and its potential significance to kimberlite melt evolution, we examine the petrography and geochemistry of the minimally altered hypabyssal monticellite-rich Leslie (Canada) and Pipe 1 (Finland) kimberlites. In these kimberlites, monticellite (Mtc) is abundant (25–45 vol%) and can be classified into two distinct morphological types: discrete and intergrown groundmass grains (Mtc-I), and replacement of olivine (Mtc-II). Monticellite in group-I kimberlites: Implications for evolution of parental melts and post-emplacement CO 2 degassing (PDF Download Available). Available from: https://www.researchgate.net/publication/318032868_Monticellite_in_group-I_kimberlites_Implications_for_evolution_of_parental_melts_and_post-emplacement_CO_2_degassing [accessed Aug 10, 2017].
DS1711-2522
2017
Abersteiner, A.Kargin, A.V., Sazonova, L.V., Nosova, A.A., Lebedeva, N.M., Tretyachenko, V.V., Abersteiner, A.Cr-rich clinopyroxene megacrysts from the Grib kimberlite, Arkangelsk province, Russia: relation to clinopyroxene-phlogopite xenoliths and evidence for mantle metasomatism by kimberlite melts.Lithos, in press available, 52p.Russia, Archangeldeposit - Grib

Abstract: To provide new insights into the origin of megacrysts and metasomatism of the subcontinental lithospheric mantle (SCLM), we present a detailed petrographic and geochemical investigation of clinopyroxene-phlogopite xenoliths and clinopyroxene megacrysts from the Grib kimberlite (Arkhangelsk diamond province, Russia). Clinopyroxene megacrysts and clinopyroxene from clinopyroxene-phlogopite xenoliths have similar petrography, major and trace element compositions, and are therefore classified as Cr-rich megacrysts. Geothermobarometry suggests that Cr-rich clinopyroxenes originate from within the SCLM (3.6-4.7 GPa and 764-922 °C). Phlogopite from clinopyroxene-phlogopite xenoliths have low-Ti and -Cr compositions that overlaps with phlogopite megacrysts from the Grib kimberlite. The clinopyroxene-phlogopite rocks within the SCLM are the main source for Cr-rich clinopyroxene and low-Ti phlogopite megacrysts in the Grib kimberlite matrix. Trace element compositions of studied Cr-rich clinopyroxenes have similar geochemical features to clinopyroxenes megacrysts occurrences worldwide and overlap with clinopyroxenes from phlogopite-garnet peridotite xenoliths from the Grib kimberlite. The strong depletion in Ti, Nb, Ta and to a lesser extent in Zr and Hf in clinopyroxene reflects equilibrium with Ti-oxides, such as ilmenite. The clinopyroxene-phlogopite xenoliths could be the final product of metasomatism of garnet peridotites within the SCLM beneath the Grib kimberlite. The calculated equilibrium of clinopyroxene melt compositions suggests that the metasomatic agents were derived from silicate-bearing kimberlite melts. The presence of veinlets infilled with kimberlitic mineral assemblages in clinopyroxene grains suggests that the clinopyroxene-phlogopite rocks experienced intense interactions with kimberlite melt after their formation, but before their entrainment into the host kimberlite magma. This interaction resulted in the formation of high-Ti and -Cr phlogopite and high-Ti clinopyroxene rims, zones and grains with spongy textures. Finally, we propose the sequence of metasomatic events that occurred in the SCLM and the subsequent formation of the Grib kimberlite.
DS1802-0216
2018
Abersteiner, A.Abersteiner, A., Kamenetsky, V.S., Kamenetsky, M., Goemann, K., Ehrig, K., Rodemann, T.Significance of halogens ( F, Cl) in kimberlite melts: insights from mineralogy and melt inclusions in the Roger pipe ( Ekati, Canada).Chemical Geology, Vol. 478, pp. 148-163.Canada, Northwest Territoriesdeposit - Roger

Abstract: The abundance and distribution of halogens (F, Cl) are rarely recorded in kimberlites and therefore their petrogenetic significance is poorly constrained. Halogens are usually present in kimberlite rocks in the structure of phlogopite and apatite, but their original concentrations are never fully retained due to the effects of alteration. To provide new constraints on the origin and evolution of halogens in kimberlites and their melts, we present a detailed study of the petrography and geochemistry of the late-Cretaceous Group-I (or archetypal) Roger kimberlite (Ekati cluster, Canada). The studied samples contain abundant anhedral-to-euhedral olivine which is set in a crystalline groundmass of monticellite, phlogopite, apatite, spinel (i.e. magnesian ulvöspinel-magnetite (MUM), Mg-magnetite, pleonaste, Cr-spinel), and perovskite along with abundant secondary alteration phases (i.e. serpentine, garnet (andradite-schlorlomite), amakinite ((Fe2 +, Mg, Mn)(OH)2), calcite). The Roger kimberlite is characterised by the highest recorded F-content (up to 2688 ppm) of the Ekati cluster kimberlites, which is reflected by the preservation of F-rich phases, where bultfonteinite (Ca4(Si2O7)(F, OH)2) and fluorite commonly replace olivine. In order to examine the composition and evolution of the kimberlite melt prior to post-magmatic processes, we studied melt inclusions in olivine, Cr-spinel, monticellite and apatite. Primary multiphase melt inclusions in Cr-spinel, monticellite and apatite and secondary inclusions in olivine are shown to contain a diversity of daughter phases and compositions that are dominated by alkali/alkali-earth (Na, K, Ba, Sr)-enriched Ca-Mg-carbonates ± F, Na-K-chlorides and sulphates, phosphates ± REE, spinel, silicates (e.g. olivine, phlogopite, (clino)humite), and sulphides. Although alkali/alkali-earth- and halogen-bearing phases are abundant in melt inclusions, they are generally absent from the kimberlite groundmass, most likely due to ubiquitous effects of syn- and/or post-magmatic alteration (i.e. serpentinisation). Comparisons between halogens and other trace elements of similar compatibility (i.e. F/Nd and Cl/U) in the Roger kimberlite and their respective estimated primitive mantle abundances show that halogens should be a more significant component in kimberlites than typically measured. We propose that fluorine in the Roger kimberlite was magmatic and was redistributed during hydrothermal alteration by Ca-bearing serpentinising fluids to produce the observed bultfonteinite/fluorite assemblages. Based the compositions and daughter mineral assemblages in primary melt inclusions and reconstructed halogen abundances, we suggest that Cr-spinel, monticellite and apatite crystallised from a variably differentiated Si-P-Cl-F-bearing carbonate melt that was enriched in alkalis/alkali-earths and highly incompatible trace elements.
DS1802-0217
2018
Abersteiner, A.Abersteiner, A., Kamenetsky, V.S., Pearson, D.G., Kamenetsky, M., Goemann, K., Ehrig, K., Rodemann, T.Monticellite in group I kimberlites: implications for evolution of parental melts and post emplacement CO2 degassing.Chemical Geology, Vol. 478, pp. 76-88.Canada, Northwest Territories, Europe, Finlanddeposit - Leslie, Pipe 1

Abstract: Monticellite is a magmatic and/or deuteric mineral that is often present, but widely varying in concentrations in Group-I (or archetypal) kimberlites. To provide new constraints on the petrogenesis of monticellite and its potential significance to kimberlite melt evolution, we examine the petrography and geochemistry of the minimally altered hypabyssal monticellite-rich Leslie (Canada) and Pipe 1 (Finland) kimberlites. In these kimberlites, monticellite (Mtc) is abundant (25-45 vol%) and can be classified into two distinct morphological types: discrete and intergrown groundmass grains (Mtc-I), and replacement of olivine (Mtc-II). Primary multiphase melt inclusions in monticellite, perovskite and Mg-magnetite contain assemblages dominated by alkali (Na, K, Ba, Sr)-enriched Ca-Mg-carbonates, chlorides, phosphates, spinel, silicates (e.g. olivine, phlogopite) and sulphides. These melt inclusions probably represent snapshots of a variably differentiated kimberlite melt that evolved in-situ towards carbonatitic and silica-poor compositions. Although unconstrained in their concentration, the presence of alkali-carbonates and chlorides in melt inclusions suggests they are a more significant component of the kimberlite melt than commonly recorded by whole-rock analyses. We present petrographic and textural evidence showing that pseudomorphic Mtc-II resulted from an in-situ reaction between olivine and the carbonate component of the kimberlite melt in the decarbonation reactio. This reaction is supported by the preservation of abundant primary inclusions of periclase and to a lesser extent Fe-Mg-oxides in monticellite, perovskite and Mg-magnetite. Based on the preservation of primary periclase inclusions, we infer that periclase also existed in the groundmass, but was subsequently altered to brucite. We suggest that CO2 degassing in the latter stages of kimberlite emplacement into the crust is largely driven by the observed reaction between olivine and the carbonate melt. For this reaction to proceed, CO2 should be removed (i.e. degassed), which will cause further reaction and additional degassing in response to this chemical system change (Le Chatelier's principle). Our study demonstrates that these proposed decarbonation reactions may be a commonly overlooked process in the crystallisation of monticellite and exsolution of CO2, which may in turn contribute to the explosive eruption and brecciation processes that occur during kimberlite magma emplacement and pipe formation.
DS1811-2552
2018
Abersteiner, A.Abersteiner, A., Kamenetsky, V.S., Golovin, A.V., Kamenetsky, M., Goemann, K.Was crustal contamination involved in the formation of the serpentine-free Udachnaya-East kimberlite? New insights into parental melts, liquids, liquidus assemblage and effects of alteration.Journal of Petrology, Vol. 59, 8, pp. 1467-1492.Russiadeposit - Udachnaya-East

Abstract: The petrologically unique Udachnaya-East kimberlite (Siberia, Russia) is characterised by unserpentinised and H2O-poor volcaniclastic and coherent units that contain fresh olivine, along with abundant alkali-rich carbonates, chlorides, sulphides and sulphates in the groundmass. These mineralogical and geochemical characteristics have led to two divergent models that advocate different origins. It has been suggested that the unserpentinised units from Udachnaya-East are representative of pristine unaltered kimberlite. Conversely, the alkali-chlorine-sulphur enrichment has been attributed to interactions with crustal materials and/or post-emplacement contamination by brines. The mineralogical and geochemical features and the compositions of melt inclusions in unserpentinised and serpentinised Udachnaya-East kimberlite varieties are compared in this study. Both varieties of kimberlite have similar major, compatible and incompatible trace element concentrations and primitive mantle normalised trace element patterns, groundmass textures and silicate, oxide and sulphide mineral compositions. However, these two kimberlite varieties are distinguished by: (i) the presence of unaltered olivine, abundant Na-K-Cl-S-rich minerals (i.e. chlorides, S-bearing alkali-carbonates, sodalite) and the absence of H2O-rich phases (i.e. serpentine, iowaite (Mg4Fe3+(OH)8OCl•3(H2O)) in unserpentinised samples, and (ii) the absence of alkali- and chlorine-enriched phases in the groundmass and characteristic olivine alteration (i.e. replacement by serpentine and/or iowaite) in serpentinised samples. In addition, melt inclusions hosted in olivine, monticellite, spinel and perovskite from unserpentinised and serpentinised kimberlite contain identical daughter phase assemblages that are dominated by alkali-carbonates, chlorides and sulphates/sulphides. This enrichment in alkalis, chlorine and sulphur in melt inclusions demonstrates that these elements were an intrinsic part of the parental magma. The paucity of alkali-carbonates and chlorides in the groundmass of serpentinised Udachnaya-East kimberlite is attributed to their instability and removal during post-emplacement alteration. All evidence previously used in support of crustal and brine contamination of the Udachnaya-East kimberlite is thoroughly evaluated. We demonstrate that ‘contamination models’ are inconsistent with petrographic, geochemical and melt inclusion data. Our combined data suggest that the Udachnaya-East kimberlite crystallised from an essentially H2O-poor, Si-Na-K-Cl-S-bearing carbonate-rich melt.
DS1812-2771
2018
Abersteiner, A.Abersteiner, A., Kamenetsky, V.S., Goemann, K., Giuliani, A., Howarth, G.H., Castillo-Oliver, M., Thomspon, J., Kamenetsky,M., Cherry, A.Composition and emplacement of the Benfontein kimberlite sill complex ( Kimberley, South Africa): textural, petrographic and melt inclusion constraints.Lithos, doi.org/10.1016 /jlithos.2018 .11.017 32p.Africa, South Africadeposit - Benfontein

Abstract: The Benfontein kimberlite is a renowned example of a sill complex and provides an excellent opportunity to examine the emplacement and evolution of intrusive kimberlite magmas. We have undertaken a detailed petrographic and melt inclusion study of the Benfontein Upper, Middle and Lower sills. These sills range in thickness from 0.25 to 5?m. New perovskite and baddeleyite U/Pb dating produced ages of 85.7?±?4.4?Ma and 86.5?±?2.6?Ma, respectively, which are consistent with previous age determinations and indicate emplacement coeval with other kimberlites of the Kimberley cluster. The Benfontein sills are characterised by large variations in texture (e.g., layering) and mineral modal abundance between different sill levels and within individual samples. The Lower Sill is characterised by carbonate-rich diapirs, which intrude into oxide-rich layers from underlying carbonate-rich levels. The general paucity of xenogenic mantle material in the Benfontein sills is attributed to its separation from the host magma during flow differentiation during lateral spreading. The low viscosity is likely responsible for non-explosive emplacement of the Benfontein sills, while the rhythmic layering is attributed to multiple magma injections. The Benfontein sills are marked by the excellent preservation of olivine and groundmass mineralogy, which is composed of monticellite, spinel, perovskite, baddeleyite, ilmenite, apatite, calcite, dolomite along with secondary serpentine and glagolevite [NaMg6[Si3AlO10](OH,O)8•H2O]. This is the first time glagolevite is reported in kimberlites. Groundmass spinel exhibits atoll-textures and is composed of a magnesian ulvöspinel magnetite (MUM) or chromite core, surrounded by occasional pleonaste and a rim of Mg-Al-magnetite. We suggest that pleonaste crystallised as a magmatic phase, but was resorbed back into the residual host melt and/or removed by alteration. Analyses of secondary inclusions in olivine and primary inclusions in monticellite, spinel, perovskite, apatite and interstitial calcite are largely composed of Ca-Mg carbonates and, to a lesser extent, alkali-carbonates and other phases. These inclusions probably represent the entrapment of variably differentiated parental kimberlite melts, which became progressively more enriched in carbonate, alkalis, halogens and sulphur during crystal fractionation. Carbonate-rich diapirs from the Lower Sill contain more exotic phase assemblages (e.g., Ba-Fe titanate, barite, ancylite, pyrochlore), which probably result from the extreme differentiation of residual kimberlite melts followed by physical separation and isolation from the parental carbonate-rich magma. It is likely that any alkali or halogen rich minerals crystallising in the groundmass were removed from the groundmass during syn-/post-magmatic alteration, or in the case of Na, remobilised to form secondary glagolevite. The Benfontein sill complex therefore provides a unique example of how the composition of kimberlites may be modified after magma emplacement in the upper crust.
DS1902-0254
2019
Abersteiner, A.Abersteiner, A., Kamenetsky, V.S., Goemann, K., Giuliani, A., Howarth, G.H., Castillo-Oliver, M., Thompson, J., Kamenetsky, M., Cherry, A.Composition and emplacement of the Benfontein kimberlite sill complex ( Kimberley, South Africa): textural, petrographic and melt inclusion constraints.Lithos, Vol. 324-325, pp. 297-314.Africa, South Africadeposit - Benfontein

Abstract: The Benfontein kimberlite is a renowned example of a sill complex and provides an excellent opportunity to examine the emplacement and evolution of intrusive kimberlite magmas. We have undertaken a detailed petrographic and melt inclusion study of the Benfontein Upper, Middle and Lower sills. These sills range in thickness from 0.25 to 5?m. New perovskite and baddeleyite U/Pb dating produced ages of 85.7?±?4.4?Ma and 86.5?±?2.6?Ma, respectively, which are consistent with previous age determinations and indicate emplacement coeval with other kimberlites of the Kimberley cluster. The Benfontein sills are characterised by large variations in texture (e.g., layering) and mineral modal abundance between different sill levels and within individual samples. The Lower Sill is characterised by carbonate-rich diapirs, which intrude into oxide-rich layers from underlying carbonate-rich levels. The general paucity of xenogenic mantle material in the Benfontein sills is attributed to its separation from the host magma during flow differentiation during lateral spreading. The low viscosity is likely responsible for non-explosive emplacement of the Benfontein sills, while the rhythmic layering is attributed to multiple magma injections. The Benfontein sills are marked by the excellent preservation of olivine and groundmass mineralogy, which is composed of monticellite, spinel, perovskite, baddeleyite, ilmenite, apatite, calcite, dolomite along with secondary serpentine and glagolevite [NaMg6[Si3AlO10](OH,O)8•H2O]. This is the first time glagolevite is reported in kimberlites. Groundmass spinel exhibits atoll-textures and is composed of a magnesian ulvöspinel - magnetite (MUM) or chromite core, surrounded by occasional pleonaste and a rim of Mg-Al-magnetite. We suggest that pleonaste crystallised as a magmatic phase, but was resorbed back into the residual host melt and/or removed by alteration. Analyses of secondary inclusions in olivine and primary inclusions in monticellite, spinel, perovskite, apatite and interstitial calcite are largely composed of Ca-Mg carbonates and, to a lesser extent, alkali-carbonates and other phases. These inclusions probably represent the entrapment of variably differentiated parental kimberlite melts, which became progressively more enriched in carbonate, alkalis, halogens and sulphur during crystal fractionation. Carbonate-rich diapirs from the Lower Sill contain more exotic phase assemblages (e.g., Ba-Fe titanate, barite, ancylite, pyrochlore), which probably result from the extreme differentiation of residual kimberlite melts followed by physical separation and isolation from the parental carbonate-rich magma. It is likely that any alkali or halogen rich minerals crystallising in the groundmass were removed from the groundmass during syn-/post-magmatic alteration, or in the case of Na, remobilised to form secondary glagolevite. The Benfontein sill complex therefore provides a unique example of how the composition of kimberlites may be modified after magma emplacement in the upper crust.
DS1902-0255
2019
Abersteiner, A.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.
DS1902-0294
2018
Abersteiner, A.Malyeshev, S.V., Pasenko, A.M., Ivanov, A.V., Gladkochub, D.P., Savatenkov, V.M., Meffre, S., Abersteiner, A., Kamenetsky, V.S., Shcherbakov, V.D.Geodynamic significance of the Mesoproterozoic magmatism of the Udzha paleo-rift ( Northern Siberian craton) based in U-Pb geochronology and paleomagnetic data.Minerals ( mdpi.com), Vol. 8, 12, 11p. PdfRussia, Siberiacraton

Abstract: The emplacement age of the Great Udzha Dyke (northern Siberian Craton) was determined by the U-Pb dating of apatite using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). This produced an age of 1386 ± 30 Ma. This dyke along with two other adjacent intrusions, which cross-cut the sedimentary units of the Udzha paleo-rift, were subjected to paleomagnetic investigation. The paleomagnetic poles for the Udzha paleo-rift intrusions are consistent with previous results published for the Chieress dyke in the Anabar shield of the Siberian Craton (1384 ± 2 Ma). Our results suggest that there was a period of intense volcanism in the northern Siberian Craton, as well as allow us to reconstruct the apparent migration of the Siberian Craton during the Mesoproterozoic.
DS1706-1095
2017
Abert, C.Marshak, S., Domrois, S., Abert, C., Larson, T., Pavlis, G., Hamburger, M., Yang, X., Gilbert, H., Chen, C.The basement revealed: tectonic insight from a digital elevation model of the Great Unconformity, USA cratonic platform.Geology, Vol. 45, 5, pp. 391-394.United Statestectonics - Mid continent

Abstract: Across much of North America, the contact between Precambrian basement and Paleozoic strata is the Great Unconformity, a surface that represents a >0.4 b.y.-long hiatus. A digital elevation model (DEM) of this surface visually highlights regional-scale variability in the character of basement topography across the United States cratonic platform. Specifically, it delineates Phanerozoic tectonic domains, each characterized by a distinct structural wavelength (horizontal distance between adjacent highs) and/or structural amplitude (vertical distance between adjacent lows and highs). The largest domain, the Midcontinent domain, includes long-wavelength epeirogenic basins and domes, as well as fault-controlled steps. The pronounced change in land-surface elevation at the Rocky Mountain Front coincides with the western edge of the Midcontinent domain on the basement DEM. In the Rocky Mountain and Colorado Plateau domains, west of the Rocky Mountain Front, structural wavelength is significantly shorter and structural amplitude significantly higher than in the Midcontinent domain. The Bordering Basins domain outlines the southern and eastern edges of the Midcontinent domain. As emphasized by the basement DEM, several kilometers of structural relief occur across the boundary between these two domains, even though this boundary does not stand out on ground-surface topography. A plot of epicenters on the basement DEM supports models associating intraplate seismicity with the Midcontinent domain edge. Notably, certain changes in crustal thickness also coincide with distinct changes in basement depth.
DS1312-0003
2013
Abete, T.Abete, T.Deep carbonate recycling and metasomatic enrichment of the sub-continental lithospheric mantle inferred from mantle xenoliths of the East African Rift system.Goldschmidt 2013, AbstractAfricaMetasomatism
DS1709-2067
2017
Abhinay, K.Upadhyay, D., Ranjan, S., Abhinay, K., Pruseth, K.L., Nanda, J.K.India-Antarica connection: constraints from deformed alkaline rocks and carbonatites.Goldschmidt Conference, abstract 1p.Indiacarbonatites

Abstract: Deformed Alkaline Rocks and Carbonatites (DARCs) are markers of suture zones where continents have rifted apart and later amalgamated [1]. Petrological and geochronological data indicates that parts of India and East Antarctica may have been involved in several episodes of collision and breakup during the assembly of past supercontinents [2]. DARCs at the eastern margin of the Eastern Ghats Province (EGP) in India preserve the record of these amalgamation and breakup events. It is thought that the Napier Complex of East Antarctica collided with the Dharwar Craton of India at ca. 1.60 Ga forming the central and eastern Indian shield [3]. New zircon U-Pb ages from DARCs at the EGP margin show that the alkaline complexes (Kamakhyanagar: 1350±14 Ma Rairakhol: 1379±6 Ma; Khariar: 1478±5 Ma; Koraput: 1387±34 Ma; Kunavaram: 1360±5 Ma; Jojuru: 1352±6 Ma) were emplaced in a narrow time interval. The alkaline magmatism marks an episode of rifting in the Indo-Antarctic continental fragment, correlatable with breakup of the Columbia supercontinent. Metamorphic zircon from the alkaline rocks furnish age populations at 917-950 Ma, 792- 806 Ma and 562-569 Ma. The 917-950 Ma ages are correlated with the closure of an oceanic basin between the Ruker Terrane of East Antarctica and the Indian Shield during the assembly of the Rodinia supercontinent. This led to the collision of the Ruker Terrane with the combined India-Napier Complex producing the Grenville-age EGPRayner Complex orogen [2, 3]. The 792-806 Ma ages record the disintegration of Rodinia when Greater India started to break away from East Antarctica [4]. In the early Paleozoic, India reconverged towards Antarctica and Australia during Gondwanaland assembly. The 562-569 Ma zircon ages date the resulting collisions during Pan-African orogenesis.
DS1710-2272
2017
Abhinay, K.Upadhyay, D., Ranjan, S., Abhinay, K., Pruseth, K.L., Nanda, J.K.India-Antarctica connection: constraints from deformed alkaline rocks and carbonatites.Goldschmidt Conference, 1p. AbstractIndiacarbonatites

Abstract: Re-Os and platinum group element analyses are reported for peridotite xenoliths from the 533 Ma Venetia kimberlite cluster situated in the Limpopo Mobile Belt, the Neoarchaean collision zone between the Kaapvaal and Zimbabwe Cratons. The Venetian xenoliths provide a rare opportunity to examine the state of the cratonic lithosphere prior to major regional metasomatic disturbance of Re-Os systematics throughout the Phanerozoic. The 32 studied xenoliths record Si-enrichment that is characteristic of the Kaapvaal lithospheric mantle and can be subdivided into five groups based on Re-Os analyses. The most pristine group I samples (n = 13) display an approximately isochronous relationship and fall on a 3.28 ± 0.17 Ga (95 % conf. int.) reference line that is based on their mean TMA age. This age overlaps with the formation age of the Limpopo crust at 3.35-3.28 Ga. The group I samples derive from ~50 to ~170 km depth, suggesting coeval melt depletion of the majority of the Venetia lithospheric mantle column. Group II and III samples have elevated Re/Os due to Re addition during kimberlite magmatism. Group II has otherwise undergone a similar evolution as the group I samples with overlapping 187Os/188Os at eruption age: 187Os/188OsEA, while group III samples have low Os concentrations, unradiogenic 187Os/188OsEA and were effectively Re-free prior to kimberlite magmatism. The other sample groups (IV and V) have disturbed Re-Os systematics and provide no reliable age information. A strong positive correlation is recorded between Os and Re concentrations for group I samples, which is extended to groups II and III after correction for kimberlite addition. This positive correlation precludes a single stage melt depletion history and indicates coupled remobilisation of Re and Os. The combination of Re-Os mobility, preservation of the isochronous relationship, correlation of 187Os/188Os with degree of melt depletion and lack of radiogenic Os addition puts tight constraints on the formation and subsequent evolution of Venetia lithosphere. First, melt depletion and remobilisation of Re and Os must have occurred within error of the 3.28 Ga mean TMA age. Second, the refractory peridotites contain significant Re despite recording >40 % melt extraction. Third, assuming that Si-enrichment and Re-Os mobility in the Venetia lithospheric mantle were linked, this process must have occurred within ~100 Myr of initial melt depletion in order to preserve the isochronous relationship. Based on the regional geological evolution, we propose a rapid recycling model with initial melt depletion at ~3.35 Ga to form a tholeiitic mafic crust that is recycled at ~3.28 Ga, resulting in the intrusion of a TTG suite and Si-enrichment of the lithospheric mantle. The non-zero primary Re contents of the Venetia xenoliths imply that TRD model ages significantly underestimate the true depletion age even for highly depleted peridotites. The overlap of the ~2.6 Ga TRD ages with the time of the Kaapvaal-Limpopo collision is purely fortuitous and has no geological significance. Hence, this study underlines the importance of scrutiny if age information is to be derived from whole rock Re-Os analyses.
DS0712-0001
2007
Abo-Ezz, E.R.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
DS2002-0007
2002
Aboriginal Community Development and the Mineral IndustryAboriginal Community Development and the Mineral IndustryAnnual conference proceedings Vol.sInfo@canadaforum.com, 1993-2001 listing of conference proceedingsCanadaMineral development - partnerships, legal
DS1990-1386
1990
Abouassaleh, K.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
DS1992-0138
1992
Abouchami, W.Boher, M., Abouchami, W., Michard, A., Albarede, F., Arndt, N.T.Crustal growth in West Africa at 2.1 GaJournal of Geophysical Research, Vol. 97, No. B1, January 10, pp. 345-369GlobalGeophysics, Craton
DS1989-0002
1989
Abouchamy, W.Abouchamy, W., Boher, M., Michard, A., Albarede, E., et al.Crustal growth in West Africa at 2.1 Ga: preliminary resultsEos, Vol. 70, No. 15, April 11, p. 485. (abstract.)West Africa, Mauritania, Senegal, Mali, Guinea, Ivory CoastGhana, Burkina Faso, Tectonics, Geochronology
DS1991-1095
1991
Abousetta, A.McClay, K.R., Waltham, D.A., Scott, A.D., Abousetta, A.Physical and seismic modelling of listric normal fault geometriesThe geometry of normal faults, editors Roberts, A.M., Yielding, G., No. 56, pp. 231-239GlobalStructure -faults, Fault geometry -listric
DS0412-0577
2003
Abraham, A.C.Francis, D., Abraham, A.C.Interrogating the Cordillera lithosphere with mafic volcanics and mantle xenoliths.Geological Association of Canada Annual Meeting, Abstract onlyCanada, Northwest TerritoriesXenoliths
DS2001-0003
2001
Abraham, A.C.Abraham, A.C., Francis, D., Polve, M.Recent alkaline basalts as probes of the lithospheric mantle roots of the Northern Canadian Cordillera.Chemical Geology, Vol. 175, pp. 361-86.Yukon, British Columbia, CordilleraTectonics, Geochronology
DS2003-0423
2003
Abraham, A.C.Francis, D., Abraham, A.C.Interrogating the Cordillera lithosphere with mafic volcanics and mantle xenolithsGeological Association of Canada Annual Meeting, Abstract onlyNorthwest TerritoriesXenoliths
DS1994-0008
1994
Abraham, A.P.G.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
Abraham, A.P.G.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
DS1860-0529
1887
Abraham, F.Abraham, F.Die Diamant Gesellschaften SuedafrikasBerlin: Steinitz, 115P.Africa, South AfricaHistory, Economics
DS0412-1532
2003
AbrahamsenPersonen, L.J., Elming, Mertansen, Pisarvesky, D' Agrilla Filho, Meert, Schmidt, Abrahamsen, BylundPaleomagnetic configuration of continents during the Proterozoic.Tectonophysics, Vol. 375, 1-4, pp. 289-324.MantleMagnetics
DS1112-0280
2011
Abrajevitch, A.Dominguez, A.R., Van der Voo, R., Torsvik, T.H., Hendriks, B.W.H, Abrajevitch, A., Domeier, M., Larsen, B.T., Rousse, S.The ~270 Ma paleolatitude of Baltica and its significance for Pangea models.Geophysical Journal International, In press availableEurope, Baltic ShieldGeochronology
DS0612-1129
2006
Abramov, S.S.Rass, I.T., Abramov, S.S., Utenkov, V.A., Kozlovskii, V.M., Korpechkov, D.I.Role of fluid in the genesis of carbonatites and alkaline rocks: geochemical evidence.Geochemistry International, Vol. 44, 7. pp. 656-664.RussiaCarbonatite
DS1975-0218
1976
Abramov, V.A.Abramov, V.A., Popolitov, E.I.Geochemical Properties of Xenoliths of Upper Mantle RocksDoklady Academy of Science USSR, Earth Science Section., Vol. 231, No. 1-6, PP. 172-175.RussiaGeochemistry, Kimberlite, Garnet
DS1990-0102
1990
Abramovich, I.I.Abramovich, I.I., Klushin, I.G.Geodynamics and metallogeny of folded beltsA.a. Balkema Publ, 255pRussiaBook -ad, Metallogeny -folded belts
DS1986-0797
1986
Abramovich, M.G.Tauson, V.L., Abramovich, M.G.Polymorphism of crystals and phase dimensional effect: graphite- diamondtransformation. (Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 287, No. 1, pp. 201-205RussiaDiamond morphology
DS1987-0727
1987
Abramovitch, M.G.Tauson, V.L., Abramovitch, M.G.Polymorphism of crystals and the phase size effect: the graphite diamondtransitionDoklady Academy of Science USSR, Earth Science Section, Vol. 287, No. 1-6, pp. 148-152RussiaBlank
DS1997-0006
1997
Abramovitz, T.Abramovitz, T., Berthelsen, A., Thybo, H.Proterozoic sutures and terranes in the southeastern Baltic Shield interpreted from BABEL deep seismic data.Tectonophysics, Vol. 270, No. 3/4, March 15, pp. 259-278.Sweden, Norway, Baltic ShieldGeophysics - seismic BABEL, Tectonics
DS2002-0122
2002
Abramovitz, T.Bayer, U., Thybo, H., Abramovitz, T.Inter wedging and inversion structures around the trans European suture zone in the Baltic sea, a manifestation of compressive tectonic phases.Tectonophysics, Vol. 360, 1-4, pp. 265-80.Europe, Baltic SeaTectonics
DS1983-0527
1983
Abrams, G.Raab, P., Moss, C., Abrams, G.Aeromagnetic Dat a from Southeastern MissouriUnited States Geological Survey (USGS) GD 83-004, DOI/DF 83-005., GlobalMid Continent
DS1990-0103
1990
Abrams, G.A.Abrams, G.A., Grauch, V.J., Bankey, V.Complete bouguer gravity anomaly map of the Uinta and Piceance basins andvicinity, Utah and ColoradoUnited States Geological Survey (USGS) Open File, No. MF-2008-D, 1 : 500, 000Utah, Colorado PlateauGeophysics -gravity, Map
DS1994-0009
1994
Abrams, G.A.Abrams, G.A., Knepper, D.H.Complete bouguer gravity anomaly isostatic residual gravity, gradient and terrain mapsUnited States Geological Survey (USGS), GP-1009, 1: 1 M.ColoradoGeophysics -gravity, Map
DS1993-1808
1993
Abramson, E.H.Zaug, J.M., Abramson, E.H., Brown, J.M., Slutsky, L.J.Second velocites in olivine at earth mantle pressuresScience, Vol. 260, No. 5113, June 4, pp. 1487-1488.MantleOlivine
DS0812-0001
2008
Abrates, M.Abrates, M., Viererck-Goette, L., Ulyych, J., Munsel, D.Melilitic rocks of the CECIP examples from Vogtland W. Bohemia.Goldschmidt Conference 2008, Abstract p.A2.Europe, Germany, Czech RepublicMelilitite
DS2000-0350
2000
AbreuGorayeb, P.S.S., Moura, C.A.V., Gaudette, H.E., AbreuTransamazonic evolution of Sao Luis Craton and northwest Ceara Brasil - and its coerrelation with west Africa.Igc 30th. Brasil, Aug. abstract only 1p.Brazil, West AfricaCraton - tectonics, Magmatism
DS1983-0001
1983
Abreu, P.D.A.Abreu, P.D.A., Munhoz, D.T.V.A Paleogeographic Reconstruction and a Study of Heavy Minerals As An indicator of Primary Diamond Sources in the Serra Do Espinhaco, Minasgerais.(in Portugese).In: Geology of the Precambrian, Geological Society Brasil, Geol. Bol, Vol. 3, pp. 219-234BrazilHeavy Minerals, Alluvials
DS1709-1949
2017
Abritis, A.Abritis, A., McCook, A.Cash bonuses for peer reviewed papers go global. Overview citing Chin a excessive payments.Retraction Watch, Aug. 10, 3p.Global, Chinaresearch papers

Abstract: China is well known for the generous bonuses it pays scientists who land a peer-reviewed publication in a prestigious research journal. But scientists in many countries are reaping similar bounties. After spotting a discussion on a scholarship listserv about the topic, we dug further to find official documents on such payments from institutions named in the thread. Searching the internet using key terms such as “publishing cash incentives” and “schemes cash publishing” widened our net. We relied mostly on online documents in English, so we surely missed some policies. The numbers in the graphic below represent the maximum amounts we uncovered at a particular institution in a specific country. Even under those constraints, we documented publishing incentives from all corners of the globe, including at a number of U.S. institutions. Awards are primarily cash; some are as small as the $10 that Oakwood University in Huntsville, Alabama, bestows on authors when their papers are cited in the literature. Some institutions designate payments for faculty members, whereas others reward student authors.
DS2001-1057
2001
AbsarShanker, R., Nag, S., Ganguly, A., Absar, Rawat, SinghAre Majhgawan Hinota pipe rocks truly group I kimberlite?Indian Acad. Sciences Earth and Plan., Vol. 110, No. 1, pp. 63-76.IndiaKimberlite - classification, Deposit - Majhgawan
DS1312-0957
2013
Abson, J.P.Ward, J.D., De Wit, M.C., Revitt, A.W., Abson, J.P.Geological and economic aspects of the Proterozoic Umkondo Group diamond placer near Marange, Zimbabwe.Geoforum , 32ppt. AvailableAfrica, ZimbabweDeposit - Marange area
DS1998-1582
1998
Abson, J.P.Williams, C.M., Robey, J.A., Abson, J.P.Petrography and mineral chemistry of the Mwenezi - 01 kimberlite, Zimbabwe.7th International Kimberlite Conference Abstract, pp. 955-7.ZimbabwePetrography, geothermometry, Deposit - Mwenezi-01
DS1989-0003
1989
Abstract volumeAbstract volumeMining environment in the '90s. 95th Annual ConventionNorthwest Mining Association, Dec. 6-8, 1989GlobalNorthwest Mining Convention, Mineral deposits
DS1112-1146
2011
Abt, D.Yuan, H., Romanowicz, B., Fischer, K., Abt, D.3-D shear wave radially and azimuthally anisotropic velocity model of the North American upper mantle.Geophysical Journal International, in press Jan. 17Canada, United StatesGeophysics - seismics
DS1012-0200
2010
Abt, D.L.Fischer, K.M., Ford, H.A., Abt, D.L., Rychert, C.A.The lithosphere asthenosphere boundary.Annual Review of Earth and Planetary Sciences, Vol. 38, pp. 551-575.MantleBoundary
DS1112-0334
2010
Abt, D.L.Ford, H.A., Fischer, K.M., Abt, D.L., Rychert, C.A., Elkins-Tanton, L.T.The lithosphere asthenosphere boundary and cratonic lithospheric layering beneath Australia from Sp wave imaging.Earth and Planetary Science Letters, Vol. 300, 3-4, pp. 299-310.AustraliaGeophysics - seismics
DS1312-0004
2013
Abu-Alam, T.S.Abu-Alam, T.S., Santosh, M., Brown, M.,Stuwe, K.Gondwana collision.Mineralogy and Petrology, Vol. 107, pp. 631-634.MantleKenoraland
DS1989-0004
1989
Abyzov, A.M.Abyzov, A.M., Smirnov, E.P.Chromatographic spectra of thermal-description of CO, CO2, and H2O from graphite and diamond.(Russian)Kinet. Catal., (Russian), Vol. 30, No. 4, Jul-Aug. pp. 796-802RussiaDiamond morphology, Chromatographic spectra
DS1012-0001
2010
Abzalov, M.Z.Abzalov, M.Z.Use of twinned drillholes in mineral resource estimation.Exploration and Mining Geology, Vol. 118, 1-4, pp. 13-23.TechnologyQuality control - not specific to diamonds
DS1809-2100
2018
Accardo, N.Tepp, G., Ebinger, C.J., Zal, H., Gallacher, R., Accardo, N., Shillington, D.J., Gaherty, J., Keir, D., Nyblade, A.A., Mbogoni, G.J., Chindandali, P.R.N., Ferdinand-Wambura, R., Mulibo, G.D., Kamihanda, G.Seismic anistrotropy of the Upper mantle below the western rfit, East Africa.Journal of Geophysical Research, Vol. 123, 7, pp. 5644-5660.Africa, east Africageophysics - seismic

Abstract: Although the East African rift system formed in cratonic lithosphere above a large-scale mantle upwelling, some sectors have voluminous magmatism, while others have isolated, small-volume eruptive centers. We conduct teleseismic shear wave splitting analyses on data from 5 lake-bottom seismometers and 67 land stations in the Tanganyika-Rukwa-Malawi rift zone, including the Rungwe Volcanic Province (RVP), and from 5 seismometers in the Kivu rift and Virunga Volcanic Province, to evaluate rift-perpendicular strain, rift-parallel melt intrusion, and regional flow models for seismic anisotropy patterns beneath the largely amagmatic Western rift. Observations from 684 SKS and 305 SKKS phases reveal consistent patterns. Within the Malawi rift south of the RVP, fast splitting directions are oriented northeast with average delays of ~1 s. Directions rotate to N-S and NNW north of the volcanic province within the reactivated Mesozoic Rukwa and southern Tanganyika rifts. Delay times are largest (~1.25 s) within the Virunga Volcanic Province. Our work combined with earlier studies shows that SKS-splitting is rift parallel within Western rift magmatic provinces, with a larger percentage of null measurements than in amagmatic areas. The spatial variations in direction and amount of splitting from our results and those of earlier Western rift studies suggest that mantle flow is deflected by the deeply rooted cratons. The resulting flow complexity, and likely stagnation beneath the Rungwe province, may explain the ca. 17 Myr of localized magmatism in the weakly stretched RVP, and it argues against interpretations of a uniform anisotropic layer caused by large-scale asthenospheric flow or passive rifting.
DS1212-0001
2012
Accredited Gemologists AssociationAccredited Gemologists AssociationThrough the looking glass - the future of diamonds. Panel discussion - Lucent new technology; HPHT diamond technology; Diamond supply? (Coopersmith)Conference Las Vegas May 31, Held May 31TechnologyPanel discussion
DS1702-0234
2016
Acededo, R.D.Presser, J.L.B., Farina-Dolsa, S., Larroza-Cristaldo, F.A., Rocca, M., Alonso, R.N., Acededo, R.D., Cabral-Antunez, N.D., Baller, L., Zarza-Lima, P.R., Sekatcheff, J.M.Modeled mega impact structures in Paraguay: II the eastern region. **PortBoletin del Museo Nacional de Historia Narural del Paraguay, Vol. 20, 2, pp. 205-213. pdf available in * PortSouth America, ParaguayImpact Crater

Abstract: We report here the discovery and study of several new modeled large impact craters in Eastern Paraguay, South America. They were studied by geophysical information (gravimetry, magnetism), field geology and also by microscopic petrography. Clear evidences of shock metamorphic effects were found (e.g., diaplectic glasses, PF, PDF in quartz and feldspar) at 4 of the modeled craters: 1) Negla: diameter:~80-81 km., 2) Yasuka Renda D:~96 km., 3) Tapyta, D: ~80 km. and 4) San Miguel, D: 130-136 km. 5) Curuguaty, D: ~110 km. was detected and studied only by geophysical information. Target-rocks range goes from the crystalline Archaic basement to Permian sediments. The modeled craters were in some cases cut by tholeiitic/alkaline rocks of Mesozoic age and partially covered by lavas of the basaltic Mesozoic flows (Negla, Yasuka Renda, Tapyta and Curuguaty). One of them was covered in part by sediments of Grupo Caacupé (age: Silurian/Devonian). Some of these modeled craters show gold, diamonds, uranium and REE mineral deposits associated. All new modeled large impact craters are partially to markedly eroded.
DS1707-1359
2017
Acevedo, R.D.Presser, J.L.B., Vladykin, N.V., Bitschene, P.R., Tondo, M.J., Acevedo, R.D., Alonso, R., Benitez, P.Olivine-lamproite from Ybtyruzu lamproite field, eastern Paraguay. *** In SpaPyroclastic Flow *** Spa, Vol. 7, 1, pp. 1-15.South America, Paraguaylamproite

Abstract: Numerous Mesozoic bodies of lamproite-like intrusions are located NE and E of the city of Villarrica, Guairá Department, in eastern Paraguay. This magmatic field, known as Ybytyruzú Field, lies immediately on the margin of the SW part of Paranapanemá cratonic-block, just of the Asunción rift backs-horst and so related to deep crustal/lithospheric fracture zones.Mostly of observed rocks are weathered, however fresh samples were collected in dykes from Acaty (=Yzu-2), Tacuarita (=Yzu-7); lava/breccias from Mbocayaty (=Yzu-3); and sill from Salto Boni (=Yzu-6). They intrude, both, the sediments (Independencia Group and Misiones Formation) and the tholeiitic basalts of the Paraná Basin. In the present study we have performed petrographic and mineral chemistry data to show that all of the study rocks, from the Ybytyruzú Field, are lamproites (leucite lamproite from Yzu-2/Yzu-3/Yzu-7 and sanidine lamproite from Yzu-6).With respect to Yzu-2, Yzu-3 and Yzu-6, the following analyzes show the lamproite character: -phenocrysts/microphenocrysts of: olivine (mg# (Mg/(Mg+Fe)) 0.80-0.85), Al-poor diopside (Al2O3 0.53-2.09% and TiO2 0.65-1.61%), phlogopite/Al-poor-Ti phlogopite (mg# 0.76-0.85, TiO2 5.8-10.2% and Al2O3 12.7-13.9%), Mg-Ti magnetites and leucite (pseudomorphs). -and matrix phases of: Al-poor diopside (Al2O3 0.39-2.46% and TiO2 0.43-1.55%), Al-poor-Ti phlogopite/biotite (mg# 0.57-0.80, TiO2 5.6-10.2% and Al2O3 8.9-12.8%), Mg-Ti magnetites/Ti-magnetites; sanidine (0-4.0% Fe2O3, 0-2.6% BaO and 0-2.5% Na2O). And as accessory phases, ilmenite (0.2-5.7% MgO and 0.3-6.6% MnO), K and Ti-rich Feeckermanite/richterite (1.32-3.6% K2O and 4.7-9.0% TiO2), K-rich Fe-Mg-Mn amphiboles, apatite and quartz (Yzu-6). And so, Ybytyruzú lamproite-like intrusions authenticates the true lamproitic province in Paraguay. III; INTERNATIONAL, 2000 BRAZIL 2000; 3 1ST INTERNATIONAL GEOLOGICAL CONGRESS; ABSTRACTS VOLUME
DS1995-0736
1995
Achache, J.Hamoudi, M., Achache, J., Cohen, Y.Global Magsat anomaly maps at ground levelEarth and Planetary Science Letters, Vol. 133, No. 3-4, July 15, pp. 533-548GlobalGeophysics -Magsat
DS1998-0570
1998
Achache, J.Hamoudi, M., Cohen, Y., Achache, J.Can the thermal thickness of the continental lithosphere be estimated from Magsat data.Tectonophysics, Vol. 284, No. 1-2, Jan. 15, pp. 19-29.MantleGeophysics - MAGSAT., Crustal thickness
DS1112-1026
2011
AchardTallaire, A., Barjon, J., Brinza, O., Achard, Silva, Mille, Issaoui, Tardieu, GicquelDislocations and impurities introduced from etch-pitts at the epitaxial growth resumption of diamond.Diamond and Related Materials, Vol. 20, 7, pp. 875-881.TechnologyDiamond morphology
DS0612-1508
2005
Achard, J.Wang, W., Tallaire, A., Hall, M.S., Moses, T.M., Achard, J., Sussmans, R.S., Gicquel, A.Experimental CVD synthetic diamonds form LIMPH-CNRD France.Gems & Gemology, Vol. 41, 3, Fall, pp. 234244.TechnologySynthetic diamonds
DS0612-0875
2001
Acharya, G.R.Mathew, M.P., Ramachandra, H.M., Gouda, H.C., Singh, R.K., Acharya, G.R., Murthy, C.V.V.S., Rao, K.S.IGRF corrected regional aeromagnetic anomaly map of parts of Peninsular India - potential for mapping and mineral exploration.National Seminar on Exploration Survey, Geological Society of India Special Publication, No. 58, pp. 395-405.India, Andhra Pradesh, Karnataka, Tamil Nadu, KeralaGeophysics - magnetics
DS1991-0002
1991
Acharya, S.Acharya, S., Anand, S., Reddy, B.R., Das, R.P.Processing of kimberlite tailings to recover magnesium as MgO or MgSO417th. International Mineral Proceedings Congress, Preprints, pp. 199-209.IndiaMineral processing, Kimberlite tailinsg -magnesiuM.
DS1991-1403
1991
Acharya, S.Reddy, B.R., Acharya, S., Anand, S., Das, R.P.Preparation and characterization of magnesium sulfate heptahydrate From kimberlite tailingsJournal of Thermal Analysis, Vol. 37, No. 5, May pp. 945-951GlobalMining, Mineral processing -tailings
DS1998-0006
1998
Acharyva, S.K.Acharyva, S.K.Break up of East Gondwana Indo-Australian continent: dispersal and accretionary history continental blocks.Journal of African Earth Sciences, Vol. 27, 1A, p. 2. AbstractGondwana, India, AustraliaTectonics, Accretion
DS1989-1371
1989
Acharyya, S.K.Sengupta, S., Acharyya, S.K., Van Den Hul, H.J., Chattopadhyay, B.Geochemistry of volcanic rocks from the Naga Hillsophiolites,northeast India and their inferred tectonic settingJournal of the Geological Society of London, Vol. 146, No. 3, May pp. 491-498IndiaHarzburgite, Tectonics
DS1990-1334
1990
Acharyya, S.K.Sengupta, S., Ray, K.K., Acharyya, S.K., de Smeth, J.B.Nature of ophiolite occurrences along the eastern margin of the Indian plate and their tectonicsignificanceGeology, Vol. 18, No. 5, May pp. 439-442IndiaOphiolites, Tectonics
DS2001-0979
2001
AchauerRitter, J.R.R., Jordan, M., Christensen, U.R., AchauerA mantle plume below the Eifel volcanic fields, GermanyEarth and Planetary Science Letters, Vol. 186, No. 1, pp. 7-14.GlobalTomography, Hot spot
DS1989-0324
1989
Achauer, U.Dahlheim, H.A., Davis, P., Achauer, U.Teleseismic investigation of the East African Rift- KenyaJournal of African Earth Sciences, Vol. 8, No. 2/3/4, pp. 461-470KenyaTectonics, Rifting
DS1991-0603
1991
Achauer, U.Green, W.V., Achauer, U., Meyer, R.P.A three dimensional seismic image of the crust and upper mantle beneath the Kenya riftNature, Vol. 354, No. 6350, November 21, pp. 199-203KenyaMantle, Tectonics -rifting Kenya Rift
DS1992-0004
1992
Achauer, U.Achauer, U.A study of the Kenya rift using delay time tomography analysis and gravitymodelingTectonophysics, Vol. 209, pp. 197-207East Africa, KenyaTectonics, Geophysics -gravity
DS1995-0006
1995
Achauer, U.Achauer, U., Ritter, J.R.R.Upper mantle structure of the Kenya Rift based on joint interpretation of delay time tomography - bouguer dataGeological Society Africa 10th. Conference Oct. Nairobi, pp. 137-8. Abstract.KenyaTectonics, Geophysics -gravity
DS0412-0002
2003
Achchepkov, I.V.Achchepkov, I.V.Empirical garnet thermobarometer for mantle peridotites.Geological Society of America, Annual Meeting Nov. 2-5, Abstracts p.326.Russia, Canada, Northwest TerritoriesGeothermometry
DS2003-0002
2003
Achchepkov, I.V.Achchepkov, I.V.Empirical garnet thermobarometer for mantle peridotitesGeological Society of America, Annual Meeting Nov. 2-5, Abstracts p.326.Russia, Northwest TerritoriesGeothermometry
DS1609-1734
2010
Acker, A.Olivier, D., Bornman, F., Roode, L., Acker, A.Finsch mine treatment plant upgrade project.The 4th Colloquium on Diamonds - source to use held Gabarone March 1-3, 2010, 14p.Africa, South AfricaDeposit - Finsch

Abstract: De Beers' Finsch Mine is situated in the Northern Cape ,province, 170 km northwest of Kimberley. The concentrator facility, designed and constructed by Bateman Engineering, was commissioned in 1967 and upgraded in 1979 using diamond liberation and extraction technology available at the time of design. Since then significant advances in diamond processing and technology have been made and these -have been incorporated into the new main treatment plant and recovery plant flowsheets, making diamond liberation and recovery from the Pre-1979 dumps a viable economic option at Finsch." Significant challenges were experienced as a result of the integration of new technology and its associated infrastructure into an existing plant. Major process flow changes were implemented during the execution phase of the project. The combined effect of these issues resulted in the project being overspent by 25% and the final handover to the Client was some 18 months later than originally planned." The paper highlights some of the difficulties experienced as a result of changes made during the execution phases of the project.
DS1910-0172
1911
Ackere, J. Van.Coppieters, D., Ackere, J. Van.La Regime Minier du Congo BelgeBrussels:, 288P.Democratic Republic of Congo, Central AfricaMining Industry, Kimberley
DS0912-0001
2009
Ackerman, L.Ackerman, L., Walker, R.J., Puchtel, I.S., Pitcher, L., Jelinek, E., Strnad, L.Effects of melt percolation on highly siderophile elements and Os isotopes in subcontinental lithospheric mantle: a study of upper mantle profile central EuropeGeochimica et Cosmochimica Acta, Vol. 73, 8, pp. 2400-2414.Europe, Czech RepublicGeochonology
DS1112-0002
2011
Ackerman, L.Ackerman, L., Spacek, P., Svojtka, M.Pyroxenite xenoliths from Cenozoic alkaline basalts, Bohemian Massif.Goldschmidt Conference 2011, abstract p.406.Europe, Bohemia, PolandBasanites, Foidites
DS1606-1076
2016
Ackerman, L.Ackerman, L., Bizimis, M., Haluzova, E., Slama, J., Svojtka, M.Re-Os and Lu-Hf isotopic constraints on the formation and age of mantle pyroxenites from the Bohemian Massif.Lithos, Vol. 256-257, pp. 197-210.Europe, Czech Republic, AustriaPyroxenite

Abstract: We report on the Lu-Hf and Re-Os isotope systematics of a well-characterized suite of spinel and garnet pyroxenites from the Gföhl Unit of the Bohemian Massif (Czech Republic, Austria). Lu-Hf mineral isochrons of three pyroxenites yield undistinguishable values in the range of 336-338 Ma. Similarly, the slope of Re-Os regression for most samples yields an age of 327 ± 31 Ma. These values overlap previously reported Sm-Nd ages on pyroxenites, eclogites and associated peridotites from the Gföhl Unit, suggesting contemporaneous evolution of all these HT-HP rocks. The whole-rock Hf isotopic compositions are highly variable with initial eHf values ranging from - 6.4 to + 66. Most samples show a negative correlation between bulk rock Sm/Hf and eHf and, when taking into account other characteristics (e.g., high 87Sr/86Sr), this may be explained by the presence of recycled oceanic sediments in the source of the pyroxenite parental melts. A pyroxenite from Horní Kounice has decoupled Hf-Nd systematics with highly radiogenic initial eHf of + 66 for a given eNd of + 7.8. This decoupling is consistent with the presence of a melt derived from a depleted mantle component with high Lu/Hf. Finally, one sample from Becváry plots close to the MORB field in Hf-Nd isotope space consistent with its previously proposed origin as metamorphosed oceanic gabbro. Some of the websterites and thin-layered pyroxenites have variable, but high Os concentrations paralleled by low initial ?Os. This reflects the interaction of the parental pyroxenitic melts with a depleted peridotite wall rock. In turn, the radiogenic Os isotope compositions observed in most pyroxenite samples is best explained by mixing between unradiogenic Os derived from peridotites and a low-Os sedimentary precursor with highly radiogenic 187Os/188Os. Steep increase of 187Os/188Os at nearly uniform 187Re/188Os found in a few pyroxenites may be connected with the absence of primary sulfides, but the presence of minor late stage sulfide-bearing veinlets likely associated with HT-HP metamorphism at crustal conditions.
DS1707-1300
2017
Ackerman, L.Ackerman, L., Magna, T., Rapprich, V., Upadhyay, D., Kratky, O., Cejkova, B., Erban, V., Kochergina, Y.V., Hrstka, T.Contrasting petrogenesis of spatially related carbonatites from Samalpatti and Sevattur, Tamil Nadu, India.Lithos, Vol. 284-285, pp. 257-275.Indiacarbonatite - Samalpatti, Sevattur

Abstract: Two Neoproterozoic carbonatite suites of spatially related carbonatites and associated silicate alkaline rocks from Sevattur and Samalpatti, south India, have been investigated in terms of petrography, chemistry and radiogenic–stable isotopic compositions in order to provide further constraints on their genesis. The cumulative evidence indicates that the Sevattur suite is derived from an enriched mantle source without significant post-emplacement modifications through crustal contamination and hydrothermal overprint. The stable (C, O) isotopic compositions confirm mantle origin of Sevattur carbonatites with only a modest difference to Paleoproterozoic Hogenakal carbonatite, emplaced in the same tectonic setting. On the contrary, multiple processes have shaped the petrography, chemistry and isotopic systematics of the Samalpatti suite. These include pre-emplacement interaction with the ambient crustal materials with more pronounced signatures of such a process in silicocarbonatites. Calc-silicate marbles present in the Samalpatti area could represent a possible evolved end member due to the inability of common silicate rocks (pyroxenites, granites, diorites) to comply with radiogenic isotopic constraints. In addition, Samalpatti carbonatites show a range of C–O isotopic compositions, and d13CV-PDB values between + 1.8 and + 4.1‰ found for a sub-suite of Samalpatti carbonatites belong to the highest values ever reported for magmatic carbonates. These heavy C–O isotopic signatures in Samalpatti carbonatites could be indicative of massive hydrothermal interaction with carbonated fluids. Unusual high-Cr silicocarbonatites, discovered at Samalpatti, seek their origin in the reaction of pyroxenites with enriched mantle-derived alkali-CO2-rich melts, as also evidenced by mantle-like O isotopic compositions. Field and petrographic observations as well as isotopic constraints must, however, be combined with the complex chemistry of incompatible trace elements as indicated from their non-uniform systematics in carbonatites and their individual fractions. We emphasise that, beside common carriers of REE like apatite, other phases may be important for incompatible element budgets, such as mckelveyite–(Nd) and kosmochlor, found in these carbonatites. Future targeted studies, including in-situ techniques, could help further constrain temporal and petrologic conditions of formation of Sevattur and Samalpatti carbonatite bodies.
DS1710-2209
2017
Ackerman, L.Ackerman, L., Slama, J., Haluzova, E., Magna, T., Rapprich, V., Kochergin, Y., Upadhyay, D.Hafnium isotope systematics of carbonatites and alkaline silicate rocks from south and west India.Goldschmidt Conference, 1p. AbstractIndiadeposit - Amba Dongar
DS1801-0001
2017
Ackerman, L.Ackerman, L., Magna, T., Rapprich, V., Upadhyay, D., Kratky, O., Cejkova, B., Erban, V., Kochergina, Y.V., Hrstka, T.Contrasting petrogenesis of spatially related carbonatites from Samalpatti and Sevattur, Tamil Nadu, India: insights from trace element and isotopic geochemistry.Carbonatite-alkaline rocks and associated mineral deposits , Dec. 8-11, abstract p. 31-33.Indiadeposit - Samalpatti, Sevattur

Abstract: The Tamil Nadu region in southern India hosts several carbonatite bodies (e.g., Hogenakal, Samalpatti, Sevattur, Pakkanadu-Mulakkadu) which are closely associated with alkaline silicate rocks such as syenites, pyroxenites or dunites (e.g, Kumar et al., 1998; Schleicher et al., 1998; Srivastava, 1998). This is in contrast to the carbonatite occurrences in north-western India associated with the Deccan Trap basalts (e.g., Amba Dongar) or Proterozoic Newania dolomitic carbonatites. We have studied two, spatially related, Neoproterozoic carbonatite-silico(carbonatite) suites in association with alkaline silicate rocks (e.g., pyroxenite, gabbro) from Sevattur and Samalpatti in terms of petrography, chemistry and radiogenic-stable isotopic compositions in order to provide constraints on their genesis and evolution. In these two bodies, several different carbonatite types have been reported previously with striking differences in their trace element and isotopic compositions (Srivastava, 1998; Viladkar and Subramanian, 1995; Schleicher et al., 1998; Pandit et al., 2002). Collected data for previously poorly studied calcite carbonatites from the Sevattur representing the first carbonatite magmas on this locality, indicate similar geochemical characteristics to those of dolomitic carbonatites, such as high LREE/HREE ratios, very high Sr and Ba contents, large amounts of apatite and magnetite, identical Sr-Nd-C-O isotopic compositions. Thus, they were derived from an enriched mantle source without significant post-emplacement modifications through crustal contamination and hydrothermal overprint, in agreement with previous studies (e.g., Schleicher et al., 1998). Detailed microprobe analyses revealed that high levels of some incompatible elements (e.g., REE, Y, Sr, Ba) cannot be accounted by matrix calcite hosting only significant amounts of SrO (~0.6-1.2 wt.%). On the other hand, abundant micro- to nano-scale exsolution lamellae and/or inclusions of mckelveyite-(Nd) appear to host a significant fraction of LREE in parallel with apatite. Distribution of Sr is most likely influenced also by common but heterogeneously dispersed barite and strontianite. Newly acquired as well as detailed inspection of available geochemical data permits distinguish two different types of carbonatites in Samalpatti: (1) Type I similar to Sevattur carbonatites in terms of mineralogy, trace element and radiogenic-stable isotopic compositions and (2) Type II with remarkably low concentrations of REE and other incompatible trace elements, more radiogenic Sr isotopic compositions and extremely variable C–O isotopic values. The petrogenesis of the Type II seems to be intimately associated with the presence of silicocarbonatites and abundant silicate mineral domains. Instead of liquid immiscible separation from a silicate magma, elevated SiO2 contents observed in silico-carbonatites may have resulted from the interaction of primary carbonatitic melts and crustal rocks prior to and/or during magma emplacement. Arguments for such hypothesis include variable, but radiogenic Sr isotopic compositions correlated with SiO2 and other lithophile elements (e.g., Ti, Y, Zr, REE). Calc-silicate marbles present in the Samalpatti area could represent a possible evolved crustal end member for such process due to the inability of common silicate rocks (pyroxenites, granites, diorites) to comply with radiogenic isotopic constraints. The wide range of C-O isotopic compositions found in Samalpatti carbonatites belong to the highest values ever reported for magmatic carbonates and can be best explained by massive hydrothermal interaction with carbonated fluids. Unusual high-Cr silicocarbonatites were discovered at Samalpatti forming centimetre to decimetre-sized enclaves enclosed in pyroxenites with sharp contacts at hand specimen scale. Detailed microprobe analyses revealed peculiar chemical compositions of the Mgamphibole with predominantly sodic composition embaying and replacing Na-Cr-rich pyroxene (kosmochlor), accompanied by the common presence of Cr-spinel and titanite. Such association have been reported for hydrous metasomatism by Na-rich carbonatitic melts at upper mantle conditions (Ali and Arai, 2013). However, the mineralogy and the mode of occurrence of Samalpatti Mg–-r-rich silicocarbonatites argue against such origin. We explain the petrogenesis of these rocks through the reaction of pyroxenites with enriched mantle-derived alkali-CO2-rich melts, as also evidenced by mantle-like O and Hf isotopic compositions.
DS1801-0048
2017
Ackerman, L.Polak, L., Ackerman, L., Rapprich, V., Magna, T.Platinum group element and rhenium osmium geochemistry of selected carbonatites from India, USA and East africa.Carbonatite-alkaline rocks and associated mineral deposits , Dec. 8-11, abstract p. 22-23.India, United States, Africa, East Africacarbonatites

Abstract: Carbonatites and associated alkaline silicate rocks might have potential economic impact for a large variety of metals such as Cu, Ni, Fe and platinum-group elements (PGE - Os, Ir, Ru, Pd, Pt) as it is demonstrated in South Africa (Phalaborwa; Taylor et al. 2009) or Brazil (Ipanema; Fontana 2006). In addition, determined PGE contents along with Re-Os isotopic compositions may also provide important information about PGE fractionation during the genesis of upper mantle-derived carbonatitic melts and nature of their sources. Nevertheless, the existing PGE data for carbonatites are extremely rare, limited mostly to Chinese localities and they are not paralleled by Re-Os isotopic data (Xu et al. 2008). Therefore, in this study, we present the first complete PGE datasets together with Re-Os determinations for a suite of selected carbonatite bodies worldwide. We have chosen eight carbonatite sites with different alkaline rock association, age and geotectonic position. Among these, the youngest samples are from East African rift system and include Oldoinyo Dili, Tanzania with an age spanning from ~0 to 45 Ma; same as Tororo and Sukulu in Uganda (Woolley and Kjarsgaard 2008). These carbonatites are in association with pyroxenites and nepheline syenites. Another young carbonatitic complex is Amba Dongar in west India with Cretaceous age of ~65 Ma associated with alkaline volcanic rocks such as trachybasalts within Deccan Traps (Sukheswala and Udas 1963). Proterozoic bodies are represented by Iron Hill, USA carbonatites associated with pyroxenite, melitolite and ijolite with age ranging from ~520 to 580 Ma (Nash 1972). These carbonatites are famous for their intensive and varied fenitization. Last and the oldest carbonatites in this study comes from Samalpatti and Sevattur, South India having the age of ~800 Ma (Schleicher et al. 1997) and outcropping as small bodies within alkaline rocks such as pyroxenite, syenite and gabbro. The PGE concentrations and Re-Os isotopic ratios were determined by standard methods consisting of decarbonatization using HCl, decomposition of samples in Carius Tubes in the presence of reverse aqua regia and spikes (isotopic dilution), separation of Os by CHCl3 followed by N-TIMS measurements and Ir, Ru, Pd, Pt, Re isolation by anion exchange chromatography followed by ICP-MS measurements. All analysed carbonatites exhibit extremely low PGE contents (S PGE up to 1 ppb), even in the samples with high S contents (up to 1.5 wt. %). Such values are much lower than other determined so far for upper mantle-derived melts such as basalts, komatiites, etc. (Day et al. 2016). Such signatures indicate very low partitioning of PGE into carbonatitic melts and/or early separation of PGE-bearing fraction. Elements from iridium-group I-PGE; Os, Ir and Ru; mostly < 0.1 ppb) are distinctly lower compared to palladiumgroup elements and Re (PPGE; Pt, Pd, Re; mostly > 0.1 ppb) with some rocks being largely enriched in Re (up to ~6 ppb). Most of the analysed carbonatites exhibit progressive enrichment from Os to Re and consequently, PdN/ReN < 0.1 except south India carbonatites and associated alkaline rocks (> 0.30). Rocks analysed so far for Os have OsN/IrN up to 6.2 that might suggest that the carbonatites might concentrate Os over Ir. The highest HSEtot contents have been found in Mg-Cr-rich silicocarbonatites from South India (up to 40 ppb) and taking into account their only slightly radiogenic 187Os/188Os ratios (0.14-0.57), these rocks represents mixture of CO2-rich alkaline mantle melts and country rocks. Very high concentrations of HSE have been also found in magnetite separated from Fe-carbonatite from Amba Dongar, India (0.2-0.5 ppb of I-PGE and 0.9-9 ppb of P-PGE). The 187Os/188Os ratios determined so far for carbonatites from South India vary from 0.24 to 6.5 and calculated ?Os values range from +100 up to +5000. Such wide range of values suggest extremely heterogenous source of the melts and/or possible contamination by 187Os-rich crustal materials.
DS1805-0953
2018
Ackerman, M.Ivanov, A.V., Mukasa, S.B., Kamenetsky, V.S., Ackerman, M., Demonterova, E.I., Pokrovsky, B.G., Vladykin, N.V., Kolesnichenko, M.V., Litasov, K.D., Zedgenizov, D.A.Origin of high-Mg melts by volatile fluxing without significant excess of temperature.Chemical Geology, https://doi.org/ 10.1016/j .chemgeo. 2018.03.11Russiameimechites
DS1975-1226
1979
Ackermand, D.Smith, J.V., Hervig, R.L., Ackermand, D., Dawson, J.B.Potassium, Rubidium, and Barium in Micas from Kimberlite and Peridotitic xenoliths and Implications for Origin of Basaltic Rocks.International Kimberlite Conference SECOND., Vol. 1, PP. 241-251.South Africa, Canada, Ontario, QuebecBasaltic Rocks, Kiberlites, Mica
DS1975-1227
1979
Ackermans, D.Smith, J.V., Hervig, R.L., Ackermans, D., Dawson, J.B.Potassium, Rubidium and Barium in Micas from Kimberlites and Peridotitic xenoliths and Implications for Origin of Basaltic Rocks.Proceedings of Second International Kimberlite Conference, Proceedings Vol. 1, PP. 241-251.South AfricaMineralogy
DS0512-0376
2005
Acocella, V.Gudmundsson, A., Acocella, V., De Natale, G.The tectonics and physics of volcanoes.Journal of Volcanology and Geothermal Research, Vol. 144, 1-4, pp. 1-5.MantleVolcanoes
DS1960-0771
1967
Acquaah, G.H.M.Acquaah, G.H.M.The Diamond Industry in the Bonsa ValleyB.a. Thesis, University Cape Coast., Ghana, West AfricaProduction, History
DS1993-1223
1993
Acquah, P.C.Peters, J.W., Kesse, G.O., Acquah, P.C.Regional trends in African geology. Proceedings 9th. International Geol. Conference held Accra 1992Geological Society Africa/Ghana, 420pGhana, Uganda, Tanzania, Zaire, Togo, Ivory CoastGold, Tarkian, Birimian, Proterozoic, Mozambique, Book -Table of contents
DS1994-0010
1994
Acquah, P.C.Acquah, P.C.Government environmental regulations and implementation in the miningsectorNatural Resources forum, Vol. 18, No. 3, August pp. 193-206GlobalLegal, laws, Environment
DS0712-0125
2007
Acremont, E.Burov, E.,Guillou Frottier, L., Acremont, E., Le Pourthier, L., Cloetingh, S.Plume head lithosphere interactions near intra continental plate boundaries.Tectonophysics, Vol. 434, 1-4, pp. 15-38.MantleHotspots
DS2002-1193
2002
Acs, P.Ortner, H., Reiter, F., Acs, P.Easy handling of tectonic data: the program Tectonics VB for Mac and Tectonics FP for Windows.Computers and Geosciences, Vol. 28, 10, pp. 1193-1200.GlobalComputers, Program - Tectonics
DS1998-0476
1998
Acton, G.D.Garza, R.S.M., Acton, G.D., Geissman, J.W.Carboniferous through Jurassic paleomagnetic dat a and their bearing on rotation of the Colorado Plateau.Journal of Geophysical Research, Vol. 103, No. B10, Oct. 10, pp. 24179-88.Colorado PlateauGeophysics - paleomagnetics, Tectonics
DS2000-0005
2000
Acton, G.D.Acton, G.D., Tessema, A., Bilham, R.The tectonic and geomagnetic significance of paleomagnetic observations from volcanic rocks centralEarth and Planetary Science Letters, Vol. 180, No. 3-4, pp. 225-42.AfricaTectonics, Volcanics
DS1992-0605
1992
Adam, .Green, T.H., Adam, ., Sie, S.H.Trace element partitioning between silicate minerals and carbonatite at 25Kbar and application to mantle MetasomatismMineralogy and Petrology, Vol. 46, No. 3, pp. 179-184MantleSilicates, Metasomatism
DS1711-2497
2017
Adam, C.Adam, C., Caddick, M.J., King, S.D.Pyroxenite causes fat plumes and stagnant slabs.Geophysical Research Letters, DOI: 10.1003/ 2017GL072943Mantleplumes

Abstract: Conventional wisdom holds that there is a change in the pattern of mantle convection between 410 and at 660 km, where structural transformations convert olivine into its high-pressure polymorphs. In this regard, recent tomographic studies have been a complete surprise, revealing (i) rapid broadening of slow seismic anomalies beneath hotspots from hundreds of kilometers wide at shallow depths to 2000-3000 km wide deeper than ~800 km, and (ii) fast seismic anomalies associated with subducted lithosphere that appear to flounder at 800-1000 km. It is difficult to reconcile these observations with the conventional view of a mantle that experiences limited mineralogical change below 660 km. Here we propose that plumes and slabs contain significant proportions of lithologies that experience an entirely different suite of mineral reactions, demonstrating that both subducted basalt and pyroxenite upwelling in plumes experience substantial changes in mineralogy and thus physical properties at ~800 km depth. We show the importance of this for mantle rheology and dynamics and how it can explain hitherto puzzling mantle tomographic results.
DS0612-0001
2006
Adam, J.Adam, J., Green, T.Trace element partitioning between mica and amphibole bearing garnet lherzolite and hydrous basanitic melt: 1. experimental results and the investigation controlsContributions to Mineralogy and Petrology, Online, availableAustralia, TasmaniaPartitioning behaviour, melting
DS0612-0495
2006
Adam, J.Green, T.H., Hauri, E.H., Gaetani, G.A., Adam, J.New calculations on water storage in the upper mantle, and implications for mantle melting models.Geochimica et Cosmochimica Acta, Vol. 70, 18, 1, p. 215, abstract only.MantleWater
DS1212-0002
2012
Adam, J.Adam, J., Oberti, R., Camara, F., Green, T.H., Rushmer, T.The effect of water on equilibrium relations between clinopyroxenes and basanitic magmas: tracing water and non- volatile incompatible elements in the Earth's mantle.emc2012 @ uni-frankfurt.de, 1p. AbstractMantleMelting
DS1412-0864
2013
Adam, J.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
DS1605-0808
2016
Adam, J.Adam, J., Turner, M., Hauri, E.H., Turner, S.Crystal/melt partitioning of water and other volatiles during the near-solidus melting of mantle peridotite: comparisons with non-volatile incompatible elements and implications for the generation of intraplate magmatism.American Mineralogist, Vol. 101, pp. 876-888.MantleMagmatism - basanite, melting

Abstract: Concentrations of H2O, F, Cl, C, P, and S have been measured by secondary ion mass spectrometry (SIMS) in experimentally produced peridotite phases (including clinopyroxene, orthopyroxene, olivine, garnet, amphibole, and mica) and coexisting basanitic glasses. Because only two experiments produced glasses on quenching (with the melt phase in others reverting to felt-like crystallite masses) H2O concentrations in melts were also separately determined from mass-balance relationships and by assuming constant H2O/La in melts and starting materials. The resulting values were used to calculate mineral/melt partition coefficients (D values) for H2O [where DH2Ocrystal/melt = (mass fraction of H2O in crystal)/(mass fraction of H2O in melt)] for conditions of 1025-1190 °C and 1.0-3.5 GPa. These gave 0.0064-0.0164 for clinopyroxene, 0.0046-0.0142 for orthopyroxene, 0.0015-0.0016 for olivine, and 0.0016-0.0022 for garnet. Although less information was obtained for the other volatiles, F was found to be significantly more compatible than H2O during peridotite melting, whereas Cl is significantly less compatible. S also has small but appreciable solubilities in amphiboles and micas, but not in pyroxenes or olivine. The solubility of C in silicate minerals appears to be negligible, although C was present in coexisting melts (~0.5 wt% as CO2) and as residual graphite during experiments. The D values for H2O in clinopyroxene and orthopyroxene are positively correlated with ivAl but negatively correlated with the H2O concentrations of melts (when considered as wt%). These relationships are consistent with the broad trends of previously published partitioning data. Although some of the concentration dependence can be related to cross-correlation between ivAl in pyroxenes and H2O concentrations in melts (via the latter’s control of liquidus temperatures) this relationship is too inconsistent to be a complete explanation. A concentration dependence for DH2Omineral/melt can also be independently predicted from speciation models for H2O in silicate melts. Thus it is likely that DH2Opyx/melt is influenced by both ivAl and the absolute concentration of H2O in melts. DH2O/DCe for clinopyroxene is inversely correlated with M2 site radii. Because the latter decrease with increasing pressure and temperature, relatively hot and/or deeply derived melts should be enriched in Ce relative to H2O when compared to melts from cooler and shallower mantle sources. Conversely, melts from H2O-rich settings (e.g., subduction zones) should have higher H2O/Ce than their source rocks. When combined with previously obtained partitioning data for non-volatile elements (from the same experiments), our data are consistent with the enrichment of intraplate basalt sources in both volatile and non-volatile incompatible elements by small-degree melts derived from local mid-ocean ridge basalt sources. In this way, volatiles can be seen to play an active role (via their promotion of partial-melting and metasomatic processes) in the auto-regulation of incompatible element concentrations in the depleted upper mantle.
DS1808-1783
2018
Adam, J.Ravenna, M., Lebedev, S., Fullea, J., Adam, J.Shear wave velocity structure of Southern Africa's lithosphere: variations in the thickness and composition of cratons and their effect on topography.Geochemistry, Geophysics, Geosystems, Vol. 19, 5, pp. 1499-1518.Africa, South Africacraton

Abstract: Cratons, the ancient cores of continents, have an unusually thick lithosphere (the tectonic plate beneath them). At least ~200 km thick, it has a highly anomalous composition, making it less dense than the surrounding mantle. Cratonic lithosphere can thus be cooled to much lower temperatures than elsewhere. Variations in this delicate buoyancy balance probably give rise to variations in the surface elevation across the Earth's stable continents. Lithospheric thickness and composition are key parameters, but both are notoriously difficult to determine. Here we use very accurate measurements of seismic surface-wave velocities and determine deep structure beneath cratons in southern Africa. We discover an unexpectedly strong, gradual thickening of the lithosphere from the central Kaapvaal Craton to the neighboring Limpopo Belt (from 200 to 300 km thick). Curiously, surface elevation decreases monotonically with increasing lithospheric thickness. This demonstrates the effect of the deep lithosphere on topography and gives us new information on the composition of the deepest parts of lithosphere.
DS1810-2385
2018
Adam, J.Tuck-Martin, A., Adam, J., Eagles, G.New plate kinematic model and tectono-stratigraphic history of the East African and West Madagascar margins.Basin Research, doi:10.1111/bre.12294 23p.Africa, Madagascartectonics

Abstract: The continental margins of East Africa and West Madagascar are a frontier for hydrocarbon exploration. However, the links between the regional tectonic history of sedimentary basins and margin evolution are relatively poorly understood. We use a plate kinematic model built by joint inversion of seafloor spreading data as a starting point to analyse the evolution of conjugate margin segments and corresponding sedimentary basins. By correlating megasequences in the basins to the plate model we produce a margin-scale tectono-stratigraphic framework comprising four phases of tectonic development. During Phase 1 (183-133 Ma) Madagascar/India/Antarctica separated from Africa, first by rifting and later, after breakup (at ca. 170-165 Ma), by seafloor spreading in the West Somali and Mozambique basins and dextral strike-slip movement on the Davie Fracture Zone. Mixed continental/marine syn-rift megasequences were deposited in rift basins followed by shallow-marine early postrift sequences. In Phase 2 (133-89 Ma) spreading ceased in the West Somali basin and Madagascar became fixed to the African plate. However, spreading continued between the African and Antarctic plates and deposition of the early postrift megasequence continued. The onset of spreading on the Mascarene Ridge separated India from Madagascar in Phase 3 (89-60 Ma). Phase 3 was characterized by the onset of deposition of the late postrift megasequence with continued deep marine sedimentation. At the onset of Phase 4 (60 Ma onward) spreading on the Mascarene ridge ceased and the Carlsberg Ridge propagated south to form the Central Indian Ridge, separating India from the Seychelles and the Mascarene Plateau. Late postrift deposition continued until a major unconformity linked to the development of the East African Rift System marked the change to deposition of the modern margin megasequence.
DS1991-0602
1991
Adam, J.Green, T.H., Adam, J.Assessment of the garnet-clinopyroxene iron-magnesium exchange thermometer using new experimental dataJournal of Metamorphic Geology, Vol. 9, No. 3, May pp. 341-347AustraliaEclogites, Geothermetry
DS1992-0606
1992
Adam, J.Green, T.H., Adam, J., Sie, S.Trace element partitioning and mantle Metasomatism11th. Australian Geol. Convention Held Ballarat University College, Jan., Listing of papers to be given attempting to get volAustraliaGeochemistry, Mantle
DS1993-0574
1993
Adam, J.Green, T.H., Adam, J., Sie, S.H.Proton microprobe determined trace element partition coefficients betweenpargasite, augite and silicate of carbonatitic meltsEos, Transactions, American Geophysical Union, Vol. 74, No. 16, April 20, supplement abstract p. 340GlobalMineral chemistry, Carbonatite
DS2000-0359
2000
Adam, J.Green, T.H., Blundy, J.D., Adam, J., Yaxley, G.M.SIMS determination of trace element partition coefficients between clinopyroxene and basaltsLithos, Vol. 53, No. 3-4, Sept. 1, pp. 165-87.GlobalPetrology - experimental, Garnet
DS2000-0360
2000
Adam, J.Green, T.H., Blundy, J.D., Adam, J., Yaxley, G.M.SIMS determination of trace element partion coefficients between garnet, clinopyroxene and basalticLithos, Vol. 53, No. 3-4, Sept. pp. 165-87.GlobalPetrology - experimental, Gpa and Temp
DS2001-0004
2001
Adam, J.Adam, J., Green, T.Experimentally determined partition coefficients for minor and trace elements in peridotite minerals...European Journal of Mineralogy, Vol. 13, pp. 815-27.GlobalCarbonatite melt, relevance to natural Carbonatite, Microprobe ICP-MS
DS2001-0409
2001
Adam, J.Green, T., Adam, J.Partition co-efficients - modeling crust-mantle... carbonatite - a popular mantle metasomatic agent.Gemoc Annual Report 2000, p. 34-5.MantleCarbonatite, Geochemistry
DS1312-0529
2013
Adam, J.M-C.Lebedev, S., Adam, J.M-C., Meier, T.Mapping the Moho with seismic surface waves: a review, resolution analysis and recommended inversion strategies.Tectonophysics, Vol. 609, pp. 377-394.MantleMohorovic discontinuity
DS1992-0005
1992
Adamia, S.Adamia, S., et al.Geology of the Republic of Georgia: a reviewInternational Geology Review, Vol. 34, No. 5, pp. 447-476.Georgia, RussiaGeneral geology - not specific to diamonds, Gondwana
DS1992-0006
1992
Adamia, S.Adamia, S., Akhvlediani, K.T., Kilasonia, V.M., Nairn, A.E.M.Geology map of the Dubawnt Lake area, Northwest TerritoriesInternational Geology Review, Vol. 34, No. 5, May pp. 447-476Russia, GeorgiaGeology, Review
DS0612-1169
2006
Adamo, I.Rolandi, V., Brajkovic, A., Adamo, I., Landonio, M.Diamonds from Udachnaya pipe, Yakutia. Their morphology, optical and Raman characteristics, FTIR and CL features.Australian Gemmologist, Vol. 22, no. 9 Jan-Mar, pp.RussiaDiamond morphology
DS0512-0113
2005
AdamsBrenker, 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
DS2000-0256
2000
AdamsEaton, D.W., Atkinson, Ferguson, Adams, Asudeh, JonesPOLARIS: an in depth look at Canada's subcontinental mantle and earthquakehazards.Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000 Conference, 4p. abstract.Ontario, Northwest TerritoriesGeophysics - seismics, lithospheric, Structure - Phanerozoic
DS1112-0003
2011
Adams, A.Adams, A., Nyblade, A.Shear wave velocity structure of the southern African upper mantle with implications for the uplift of southern Africa.Geophysical Journal International, Vol. 186, 2, pp. 808-824,AfricaGeophysics - seismics
DS1112-0004
2011
Adams, A.Adams, A., Nyblade, A.Shear wave velocity structure of the southern African upper mantle with implications for the uplift of southern Africa.Geophysical Journal International, in press available,AfricaGeophysics - seismics
DS1212-0003
2012
Adams, A.Adams, A., Nyblade, A., Weeraratne, D.Upper mantle shear wave velocity structure beneath the East African Plateau: evidence for a deep plateauwide low velocity anomaly.Geophysical Journal International, Vol. 189, 1, pp. 123-142.AfricaGeophysics - seismics
DS1312-0662
2013
Adams, A.Odonnell, J.P., Adams, A., Nyblade, A.A., Mulibo, G.D., Tugume, F.The uppermost mantle shear wave velocty structure of eastern Africa from Rayleigh wave tomography: constraints on rift evolution.Geophysical Journal International, Vol. 194, 2, pp. 961-978.AfricaGeophysics - seismics
DS1998-0007
1998
Adams, A.E.Adams, A.E., MacKenzie, W.S.A colour atlas of carbonate sediments and rocks under the microscopeOxford University of Press, 192p. approx. $ 90.00GlobalBook - ad, Atlas - carbonate sediments
DS1992-0979
1992
Adams, C.Maclean, D., Adams, C.Diamonds in Canada odds of finding a mine are long, but favourable forWood Gundy Investment Research, June 24, 5pCanada, Northwest TerritoriesNews item, Promotional literature -background
DS1997-0007
1997
Adams, C.Adams, C.Financing exploration through Canadian markets: an updateAssaying and Reporting Conference Nov. 10-11, 1997 Singapore, 34 slide copies onlyCanadaSampling, assaying, ore reserves, discoveries, Geostatistics, gold, investment, economics, legal
DS1602-0189
2016
Adams, C.J.Augstsson, C., Wilner, A.P., Rusing, T., Niemeyer, H., Gerdes, A., Adams, C.J., Miller, H.The crustal evolution of South America from a zircon Hf-isotope perspective.Terra Nova, In press availableSouth AmericaGeochronology

Abstract: Hf-isotope data of greater than 1100 detrital zircon grains from the Palaeozoic, south-central Andean Gondwana margin record the complete crustal evolution of South America, which was the predominant source. The oldest grains, with crustal residence ages of 3.8-4.0 Ga, are consistent with complete recycling of existing continental crust around 4 Ga. We confirm three major Archaean, Palaeoproterozoic (Transamazonian) and late Mesoproterozoic to early Neoproterozoic crust-addition phases as well as six igneous phases during Proterozoic to Palaeozoic time involving mixing of juvenile and crustally reworked material. A late Mesoproterozoic to early Neoproterozoic, Grenville-age igneous belt can be postulated along the palaeo-margin of South America. This belt was the basement for later magmatic arcs and accreted allochthonous microcontinents as recorded by similar crustal residence ages. Crustal reworking likely dominated over juvenile addition during the Palaeozoic era, and Proterozoic and Archaean zircons were mainly crustally reworked from the eroding, thickened Ordovician Famatinian arc.
DS1604-0591
2016
Adams, C.J.Augustsson, C., Willner, A.P., Rusing, T., Niemeyer, H., Gerdes, A., Adams, C.J., Miller, H.The crustal evolution of South America from a zircon Hf-isotope perspective.Terra Nova, Vol. 28, 2, pp. 128-137.South AmericaTectonics

Abstract: Hf-isotope data of >1100 detrital zircon grains from the Palaeozoic, south-central Andean Gondwana margin record the complete crustal evolution of South America, which was the predominant source. The oldest grains, with crustal residence ages of 3.8-4.0 Ga, are consistent with complete recycling of existing continental crust around 4 Ga. We confirm three major Archaean, Palaeoproterozoic (Transamazonian) and late Mesoproterozoic to early Neoproterozoic crust-addition phases as well as six igneous phases during Proterozoic to Palaeozoic time involving mixing of juvenile and crustally reworked material. A late Mesoproterozoic to early Neoproterozoic, Grenville-age igneous belt can be postulated along the palaeo-margin of South America. This belt was the basement for later magmatic arcs and accreted allochthonous microcontinents as recorded by similar crustal residence ages. Crustal reworking likely dominated over juvenile addition during the Palaeozoic era, and Proterozoic and Archaean zircon was mainly crustally reworked from the eroding, thickened Ordovician Famatinian arc.
DS1412-0209
2014
Adams, D.Downes, P.J., Demeny, A., Czuppon, G., Jacques, A.L., Verrall, M., Sweetapple, M., Adams, D., McNaughton, N.J., Gwalani, L.G., Griffin, B.J.Stable H-C-O isotope and trace element geochemistry of the Cummins Range carbonatite complex, Kimberley region Western Australia: implications for hydrothermal REE mineralization, carbonatite evolution and mantle source regions.Mineralium Deposita, in press available 28p.AustraliaCarbonatite
DS1412-0210
2014
Adams, D.Downes, P.J., Demeny, A., Czuppon, G., Jaques, A.L., Verrall, M., Sweetapple, M., Adams, D., McNaughton, N.J., Gwalani, L.G., Griffin, B.J.Stable H-C-O isotope and trace element geochemistry of the Cummins Range carbonatite complex, Kimberley region western Australia: implications for hydrothermal REE mineralization, carbonatite evolution and mantle source regions.Mineralium Deposita, Vol. 49, p. 905-932.AustraliaCarbonatite
DS1603-0381
2016
Adams, D.Griffin, W.L., Gain, S.E.M., Adams, D., Huang, J-X., Saunders, M.,Toledo, V., Pearson, N.J., O'Reilly, S.Y.Heaven on Earth: tistarite ( Ti203) and other nebular phases in corundum aggregates from Mt. Carmel volcanic rocks.Israel Geological Society, pp. 85-86. abstractEurope, IsraelMoissanite

Abstract: This ending talk, focused on the ongoing cooperative research of Prof. Griffin and his team at Macquarie University and Shefa Yamim, since January 2014, highlighting unique corundum species characteristics. Preliminary results of this research were presented in the IGS Annual Meeting of 2015, whereas this year Prof. Griffin has shared innovative findings only microscopically tracked within titanium-rich corundum aggregates. One of the more abundant minerals is Tistarite (Ti2O3), previously known only as a single grain in a primitive type of meteorite (!). An article has been submitted to a scientific journal detailing this first terrestrial occurrence. Several other minerals are common in meteorites, but unknown or extremely rare on Earth. About half of these minerals are unknown to science, and will be described as new minerals in the scientific literature. The first of these is a Titanium-Aluminium-Zirconium oxide, informally known as TAZ; it will be submitted to the International Mineralogical Association for recognition as a new mineral, ShefaTAZite. Using state of the art technologies such as Thermal Ionisation Mass Spectrometry (TIMS) and Electron Microscopy Facility (EMF) that has three scanning electron microscopes, all with EBSD capability, and a transmission electron microscope - Prof. Griffin revealed spectacular imagery of minerals and rare compounds associated with titanium rich corundum aggregates.
DS1603-0382
2016
Adams, D.Griffin, W.L., Gain, S.E.M., Adams, D., Toledo, V., Pearson, N.J., O'Reilly, S.Y.Deep-Earth methane, mantle dynamics and mineral exploration: insights from northern Israel, southern Tibet and Kamchatka.Israel Geological Society, pp. 87-88. abstractEurope, Israel, TibetMoissanite
DS1992-0007
1992
Adams, D.C.Adams, D.C., Keller, G.R.A geophysical investigation of possible southern extensions of The midcontinent rift systemGeological Society of America (GSA) Abstracts with programs, 1992 Annual, Vol. 24, No. 7, abstract p. A329MidcontinentGeophysics, Tectonic, rifting
DS1992-0835
1992
Adams, D.C.Keller, G.R., Adams, D.C.Thoughts on the nature and extent of Keweenawan rifting in North America based on recent results in other rift systemsEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p. 319MidcontinentKeweenawan Rift, Tectonics
DS1994-0011
1994
Adams, D.C.Adams, D.C., Keller, G.R.Possible extension of the Midcontinent Rift in West Texas and eastern NewMexico.Canadian Journal of Earth Sciences, Vol. 31, No. 4, April pp. 709-720.Texas, New MexicoTectonics, Midcontinent Rift
DS1610-1865
2016
Adams, D.T.Griffin, W.L., Gain, S.E.M., Adams, D.T., Huang, J-X., Saunders, M., Toledo, V., Pearson, N.J., O'Reilly, S.Y.First terrestrial occurrence of tistarite ( Ti2O3): ultra-low oxygen fugacity in the upper mantle beneath Mount Carmel, Israel.Geology, Vol. 44, 10, pp. 815-818.Europe, IsraelMoissanite

Abstract: The minimum oxygen fugacity (fO2) of Earth's upper mantle probably is controlled by metal saturation, as defined by the iron-wüstite (IW) buffer reaction (FeO ? Fe + O). However, the widespread occurrence of moissanite (SiC) in kimberlites, and a suite of super-reduced minerals (SiC, alloys, native elements) in peridotites in Tibet and the Polar Urals (Russia), suggest that more reducing conditions (fO2 = 6-8 log units below IW) must occur locally in the mantle. We describe pockets of melt trapped in aggregates of corundum crystals ejected from Cretaceous volcanoes in northern Israel which contain high-temperature mineral assemblages requiring extremely low fO2 (IW < -10). One abundant phase is tistarite (Ti2O3), previously known as a single grain in the Allende carbonaceous chondrite (Mexico) and believed to have formed during the early evolution of the solar nebula. It is associated with other reduced phases usually found in meteorites. The development of super-reducing conditions in Earth's upper mantle may reflect the introduction of CH4 + H2 fluids from the deep mantle, specifically related to deep-seated volcanic plumbing systems at plate boundaries.
DS1860-0722
1892
Adams, F.D.Adams, F.D.On a Melilite Bearing Rock (alnoite) from St. Anne de Bellevue, Near Montreal.American Journal of Science, SER. 3, Vol. 43, PP. 269-279.Canada, QuebecMelilite, Alnoite
DS1900-0140
1903
Adams, F.D.Adams, F.D.The Montregian Hills- a Canadian Petrographic ProvinceJournal of GEOLOGY, Vol. 11, PP. 239-282.Canada, QuebecAlkaline rocks
DS1986-0001
1986
Adams, G.E.Adams, G.E., Bishop, F.C.The olivine-clinopyroxene geobarometer experimental results in the CEMS system and application to natural lherzolitesGeological Society of America (GSA) Abstract Volume, Vol. 18, No. 6, p. 522. (abstract.)GlobalLherzolite, Geobarometry, Thermobarome
DS1997-0167
1997
Adams, G.W.Carlson, S.M., Adams, G.W.The Diamondiferous SIX-PAK ultramafic lamprophyre diatreme, Kenosha, Wisconsin, USAInstitute Lake Superior Geology, 2p.WisconsinLamprophyre, Diamonds
DS1859-0072
1842
Adams, J.Adams, J.Memo on the Geology of Bundelk hand and JubbalporeAsiatic Soc. Bengal Journal, Vol. 11, PP. 392-411.IndiaRegional Geology
DS1983-0232
1983
Adams, J.Forsyth, D., Morel, P., Hasegawa, H., Wetmiller, R., Adams, J.Comparative Study of the Geophysical and Geological InformatAtomic Energy of Canada Research Limited., No. TR-238, 52P.Canada, OntarioTectonics
DS1989-0005
1989
Adams, J.Adams, J., Basham, P.The seismicity and seismotectonics of Canada east of the CordilleraGeoscience Canada, Vol. 16, No. 1, March pp. 3-16Appalachia, MidcontinentGeophysics, Seismics
DS1989-0547
1989
Adams, J.Grieve, R.A.F., Adams, J., Goodacre, A.K., Nevitt, L., TeskeyThe Canadian geophysical atlasGeological Society of Canada (GSC) Forum 1989, P. 12 abstractOntarioGeophysical atlas
DS1989-1687
1989
Adams, J.Zoback, M.L., Zoback, M.D., Adams, J., Assumpcao, M., et al.Global patterns of tectonic stressNature, Vol. 341, No. 6240, September 28, pp. 291-298GlobalTectonics, Rift
DS1993-0008
1993
Adams, J.Adams, J., Ckague, J.J.Neotectonics and large scale geomorphology of CanadaCanadian Journal of Earth Sciences, Vol. 17, No. 2, pp. 248-63.CanadaGeomorphology, Gophysics - seismics
DS1993-0009
1993
Adams, J.Adams, J., Clague, J.J.Neotectonics and large scale geomorphology of CanadaPhysical Georgraphy, Vol. 17, No. 2, pp.248-264CanadaGeomorphology, Tectonics, structure
DS1996-0004
1996
Adams, J.Adams, J.Paleoseismology in Canada: a dozen years of progressJournal of Geophysical Research, Vol. 101, No. 3, March 10, pp. 6193-6208.CanadaGeophysics -seismics, History
DS0512-0002
2005
Adams, M.G.Adams, M.G., Lentz, D.R., Shaw, C.S., Williams, P.F., Archibald, D.A., Cousens, B.Eocene shoshonitic mafic dykes intruding the Monashee Complex, British Columbia: a petrogenetic relationship with the Kam loops Group volcanic sequence.Canadian Journal of Earth Sciences, Vol. 42, 1, pp. 11-24.Canada, British ColumbiaShoshonite
DS1012-0769
2010
Adams, N.Sullivan, D., Adams, N.Digging in: recent developments on conflict minerals.enoughproject.org, Jan. 14p.Africa, Democratic Republic of CongoNews item - legal
DS1981-0001
1981
Adams, R.C.G.Adams, R.C.G., Bielicki, T.A., Lang, A.R.Correlation of Electrostatic Charging Patterns with Internal Structure in Diamonds.Journal of MATERIALS SCIENCE., Vol. 16, No. 9, PP. 2369-2380.GlobalDiamond Morphology
DS0712-0002
2007
Adams, S.Adams, S.King of Bling: how a poor boy from London became diamond merchant to the world's super wealthy.Forbes.com, Vol. 180, 3, August 13, p. 84.Global, Europe, EnglandNews item - Laurence Graff
DS1975-0219
1976
Adams, W.T.Adams, W.T.Gem Stones; United States Bureau of Mines, 1976United States Bureau of Mines MINERALS YEARBOOK, Vol. 1, PP. 1-10.United States, Canada, Global, South AfricaBlank
DS1975-0904
1979
Adams, W.T.Adams, W.T.Diamond-industrialUnited States Bureau of Mines MINERAL COMMODITY PROFILE., JUNE 16P.United States, GlobalProduction, Supply, Exports, Resources, Reserves
DS1900-0606
1908
Adamson, F.Adamson, F.New Patent for Improved Diamond WasherSouth African Mining Journal, Vol. 6, PT. 2, SEPT. 12TH. P. 793.Africa, South AfricaMining Methods
DS1950-0442
1959
Adamson, R.J.Adamson, R.J.Some Account of the Diamond Mining Practices in Southern Africa.South African Institute of Mining and Metallurgy. Journal, Vol. 60, No. 1, PP. 23-50.South Africa, Southwest Africa, NamibiaMining Methods, Diamond Recovery, Kimberlite Pipes
DS1960-0001
1960
Adamson, R.J.Adamson, R.J.Diamond Recovery in Southern AfricaSouth African Institute of Mining and Metallurgy. Journal, Vol. 61, SEPT., PP.South AfricaMining Methods, Diamond Recovery, Kimberlite Pipes
DS1960-0315
1963
Adamson, R.J.Adamson, R.J., Hodgson, H.F.The Re-treatment Plant at Premier Diamond MineSouth African Institute of Mining and Metallurgy. Journal, Vol. 64, SEPT. PP. 45-67.South AfricaDiamond Mining Recovery, Kimberlite Pipes
DS1920-0356
1928
Adar, D.A.Adar, D.A.Diamonds; Lippincott's Magazine, 1928Lippincott's Magazine., Vol. 47, P. 525.South AfricaCurrent Activities
DS0812-0193
2008
Adar, F.Chakhmouradian, A.R., Cooper, M.A., Medici, L., Hawthorne, F.C., Adar, F.Fluorine rich hibschite from silicocarbonatite, AfrikAnd a Complex, Russia: crystal chemistry and conditions of crystallization.Canadian Mineralogist, Vol. 46, 4, August pp.RussiaCarbonatite
DS1980-0001
1980
Adcock, G.Adcock, G.Diamonds: a New Appraisal for Estate PlannersTrusts And Estates, Vol. 119, No. 1, PP. 52-55.GlobalInvestment
DS1012-0569
2010
Adcock, S.W.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
DS1312-0875
2013
Adcock, S.W.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
DS0412-1664
2004
Addad, A.Ricolleau, A., Perrillat, J.P., Fiquet, G., Menguy, N., Daniel, I., Addad, A., Vanni, C.The fate of subducted basaltic crust in the Earth's lower mantle: an experimental petrological study.Lithos, ABSTRACTS only, Vol. 73, p. S93. abstractMantleSubduction
DS0812-0069
2008
Addad, A.Auzende, A-L., Badro, J., Ryerson, F.J., Weber, P.K., Fallon, S.J., Addad, A., Siebert, J., Fiquet, G.Element partitioning between magnesium silicate perovskite and ferropericlase: new insights into bulk lower mantle geochemistry.Earth and Planetary Science Letters, Vol. 269, 1-2, May 15, pp. 164-174.MantleGeochemistry
DS0812-0892
2008
Addison, R.Petterson, M.G., Toila, D., Cronin, S.J., Addison, R.Communicating geoscience to indigenous people: examples from the Solomon Islands.Geological Society of London Special Publication, No. 305, pp. 141-161.Asia, Solomon IslandsAboriginal
DS1212-0602
2012
Addoum, B.Roure, F., Casero, P., Addoum, B.Alpine inversion of the North Africa margin and delamination of its continental lithosphere.Tectonics, Vol. 31, 3, TC3006AfricaTectonics
DS0912-0604
2009
Adel, S.H.Purohit, M.K., Kathal, P.K., Adel, S.H.Discovery of micro-diamonds in beach sands of the Negapattinam and Vedaranniyam beaches, southern east coast of India.Current Science, Vol. 98, 6, March 25, pp.767-8.IndiaMicrodiamonds
DS2002-0008
2002
Adeoye, A.Adeoye, A.Remote sensing analysis of basement complex of southwestern Nigeria using radar imagery.16th. International Conference On Basement Tectonics '02, Abstracts, 2p., 2p.NigeriaStructure - lineaments
DS1012-0475
2010
Ader, M.Mata, J., Moreira, M., Doucelance, R., Ader, M., Silva, L.C.Noble gas and carbon isotopic signatures of Cape Verde oceanic carbonatites: implications for carbon provenance.Earth and Planetary Science Letters, Vol. 291, 1-4, pp. 70-83.Europe, Cape Verde IslandsCarbonatite
DS0612-0002
2005
Adetoro, D.O.Adetoro, D.O.Examining mediation as the opportunity cost of litigation: can it be sustained in the long term?Minerals & Energy - Raw Materials Report, Vol. 20, 2, June pp. 28-35.GlobalLegal
DS1705-0872
2017
Adetunji, J.Rollinson, H., Adetunji, J., Lenaz, D., Szilas, K.Archean chromitites show constant Fe3+/Efe in Earth's asthenospheric mantle since 3.8 Ga.Journal of Petrology, in press available 42p.Europe, Greenland, Africa, ZimbabweMelting, Fiskenaesset Compex, Ujaragssuit, Limpopo belt
DS1809-2107
2018
Adhikari, A.Vadlamani, R., Bera, M.K., Samata, A., Mukherjee, S., Adhikari, A., Sarkar, A.Oxygen, Sr and Nd isotopic evidence from kyanite eclogite xenoliths ( KL-2 pipe, Wajrakarur) for pre 1.1 Ga mantle metasomatism in eastern Dharwar SCLM.Goldschmidt Conference, 1p. AbstractIndiadeposit - KL-2

Abstract: Kyanite-eclogite xenoliths from Wajrakarur are considered as remnants of subducted ocean-floor crust. Here trace element concentration and isotopic data are presented in garnet (Grt) and kyanite (Ky) from xenoliths KL-2 E1-E4, characterized by. We use the precise 87Sr/86Sr host kimberlite groundmass perovskite ratio (0.70312-0.70333, as a proxy for the extent of kimberlitic magma infiltration at 1.1 Ga. The xenolithic Grt and Cr-rich (upto 1506 ppm) Ky have more radiogenic 87Sr/86Sr values than kimberlite, at 1.1 Ga, of 0.703829-0.705203 and 0.703811-0.704502, respectively. Furthermore, the Grt and Ky 143Nd/144Nd ratios, at 1.1 Ga, are 0.509321-0.511372 and 0.510951-0.511156, respectively, and are distinctly lower than those of the host kimberlite (0.511870-0.512290). This indicates that the infiltration of kimberlitic fluid has not altered the 87Sr/86Sr and 143Nd/144Nd ratios in the Grt and Ky, and therefore their isotope compositions must be inherited and predate the kimberlite magma generation event at 1.1 Ga. Trace elements in Grt and Ky indicate extreme metasomatism (Sr in Grt 104-296 ppm, in Ky 672-8713 ppm [limit Sr<2ppm] and Nb in Grt 0.64-1.78 ppm, in Ky 1.7-4.54 ppm [limit Nb<0.5ppm]). The xenoliths underwent at least one major melting event inferred from extreme depletions in Re, Os and 177Os/178Os ratios [5]. Their mantle-like d18O values (Grt 5.3-5.4‰, Ky 5.3-5.9‰), positive Eu anomalies in both Grt and Ky (similar to Group 1 HREE-depleted garnets of) suggests that the protolith likely was a chromite-bearing leucogabbro, emplaced as a high-pressure cumulate at the crust-mantle boundary, which was later eclogitized due to deep-seated subduction and underwent episodes of extreme melting and metasomatism before 1.1 Ga and at least before 1.7 Ga, as inferred from their youngest Re depletion dates.
DS1701-0001
2016
Adhikary, D.Adhikary, D., Sahoo, R.K., Maurya, N.Petrography and geochemistry of new finding alkaline lamprophyre dyke in eastern margin of the eastern Dharwar craton, near Khammam, Telangana India.Acta Geologica Sinica, Vol. 90, 1, p. 197. abstractIndiaLamprophyre
DS1995-0007
1995
Adisoma, G.S.Adisoma, G.S., Hester, M.G.Grade estimation and its precision in mineral resources: the jackknifeapproachAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint, No. 95-59, 8pArizonaCopper, Geostatistics -jackknife
DS1996-0005
1996
Adisoma, G.S.Adisoma, G.S., Hester, M.G.Grade estimation and its precision in mineral resources: the jacknifeapproachMining Engineering, Vol. 48, No. 2, Feb. pp. 84-88United StatesOre reserves, geostatistics, Kriging, Jacknife approach
DS1992-0008
1992
Adjei, A.O.Adjei, A.O.The significance of northeast southwest parallel fractures in the West African CratonInternational Basement Tect., No. 7, pp. 49-60.GlobalCraton, Metallogeny - not specific to diamonds
DS1412-0300
2014
Adjerid, Z.Godard, G., Chabou, M.C., Adjerid, Z.First African diamonds discovered in Algeria by the ancient Arabo-Berbers: history and insight into the source rocks.Comptes Rendus Geoscience, Vol. 346, 7-8, pp. 179-189.Africa, AlgeriaHistory, lamproite
DS1988-0001
1988
Adkins-Heljeson, D.M.Adkins-Heljeson, D.M., Berendsen, P., McCafferty, A.E.Correlation of aeromagnetic and gravity dat a in the Joplin 2degree quadrangle of Kansas and Missouri to basement composition and structureGeological Society of America Abstracts with Program, Vol. 20, No. 2, January p. 89. Sth. Central, LawrenceGlobalMid continent, Tectonics
DS1990-0997
1990
Adkins-Heljeson, D.M.McCafferty, A.E., Adkins-Heljeson, D.M., Yarger, H.L.Complete bouguer gravity anomaly map of the Joplin Quadrangle Kansas andMissouriUnited States Geological Survey (USGS) Open File No. 89-0283, 1 sheet 1: 250, 000 $3.25, GlobalGeophysics-gravity
DS1312-0005
2013
Adler, C.Adler, C.A new line of sight - Mellier CEO of De Beers.Optima, Dec. pp. 10-19.GlobalMellier discussion
DS1860-0072
1869
Adler, N.Adler, N.Diamanten in Sued-afrika Vaal RiverVerhandlungen der kk geologischen Reichsanstalt (WIEN), ALSO: NEUES JAHRB. MI, PP. 351-352; (1870 P. 485).Africa, South Africa, Cape ProvinceHistory
DS1991-0921
1991
Admakin, L.A.Kostrovitskii, S.I., Admakin, L.A.Occurrence of petrified wood in the Obnazhennaya kimberlite pipeSoviet Geology and Geophysics, Vol. 32, No. 11, pp. 70-71Russia, YakutiaFossil wood, Deposit -Obnazhennaya
DS1805-0952
2017
Admou, H.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
DS1989-1338
1989
Admou, H.Saquaque, A., Admou, H., Karson, J., Hefferan, K., Reuber, I.Precambrian accretionary tectonics in the Bou-Azzer-El Graara region, Anti-Atlas, MoroccoGeology, Vol. 17, No. 12, December pp. 1107-1110MoroccoOphiolite, Late Proterozoic
DS2000-0401
2000
Admou, H.Hefferan, K.P., Admou, H., Saquaque, A.Anti-Atlas (Morocco) role in Neoproterozoic western GondwanaPrecambrian Research, Vol. 103, No. 1-2, Sept. pp.89-96.MoroccoTectonics, Gondwana
DS1993-1838
1993
Adodin, E.E.Zudin, N.G., Adodin, E.E.Preliminary classification, evaluation and reprocessing of diamondsDiamonds of Yakutia, pp. 177-180.Russia, YakutiaDiamond evaluation
DS1989-0006
1989
Adrian, J.Adrian, J., Winfield, G.M.Geochemical and mineralogical features of a re-enriched zone within the Goudini carbonatite complex Transvaal South AfricaXiii International Geochemical Exploration Symposium, Rio 89 Brazilian Geochemical, p. 61-62. AbstractSouth AfricaCarbonatite, Goudini
DS1412-0002
2014
Adriao, A.Adriao, A., Conceicao, R., Carniel, L., Gervasoni, F.Chemical and isotopic evidences of mantle source heterogeneity in the RosaRio do Sul kimberlite province.Goldschmidt Conference 2014, 1p. AbstractSouth America, BrazilDeposit - RosaRio do Sul
DS1996-0006
1996
Adu-Anokye, S.Adu-Anokye, S., Cobblah, A., Mireku-Gyimah, D.Geostatistical mineral reserve estimation of a Diamondiferous deposit - acase study.Surface Mining, 1996, South African Institute of Mining and Metallurgy (IMM)., pp. 93-100.GhanaBirim diamond field, Diamond reserves, geostatistics
DS0412-0003
2004
Adushkin, V.V.Adushkin, V.V., Ovchinnikov, V.M.The mosaic in reflections from the Earth's solid core boundary.Doklady Earth Sciences, Vol. 397, 6, July-August pp. 883-885.MantleGeophysics - seismics
DS2000-1014
2000
Ady, B.E.Whittaker, R.C., Karpuz, R., Wheeler, W., Ady, B.E.4D regional tectonic modeling: plate reconstruction using a geographic information systemGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000, 4p. abstract.Greenland, NorwayTectonics - GIS
DS0912-0002
2009
Aeh, A.Aeh, A., Gerdes, A., Barton, J.H.Archean accretion and crustal evolution of the Kalahari craton: the zircon age and Hf isotope record of granitic rocks- Barberton/Swaziland to Francistown Arc.Journal of Petrology, Vol. 50, 5, pp. 933-966.Africa, South AfricaGeochronology
DS0512-0025
2004
Aeolus Lee, C.T.Anser Li, Z.X., Aeolus Lee, C.T.The constancy of upper mantle fo2 through time inferred from V/Sc ratios in basalts.Earth and Planetary Science Letters, Vol. 228, 3-4, pp. 483-493.MantlePetrology - basalts
DS0612-0003
2005
Aeoluslee, C.T.Aeoluslee, C.T., Leeman, W.P., Canil, D., Li, Z.X.Similar V/Sc systematics in MORB and Arc basalts: implications for the oxygen fugacities of their mantle source regions.Journal of Petrology, Vol. 46, 11, pp. 2313-2336.MantlePetrology
DS1012-0247
2010
AfanasevGrakhanov, S.A., Malanin, Yu.A., Pavlov, Afanasev, Pokhilenko, Gerasimchuk, LipashovaRhaetian diamond placers in Siberia.Russian Geology and Geophysics, Vol. 51, pp. 127-135.Russia, Yakutia, SakhaAlluvials
DS1612-2272
2016
Afanasev, A.Afanasev, A., Belyaeva, E.Linear stability analysis for hydrothermal alteration of kimberlitic rocks.Geophysical Journal International, Vol. 205, 3, pp. 1874-1885.TechnologyAlteration

Abstract: The influx of groundwater into hot kimberlite deposits results in the reaction of water with olivine-rich rocks. The products of the reaction are serpentine and release of latent heat. The rise of temperature due to the heat release increases the rate of the reaction. Under certain conditions, this self-speeding up of the reaction can result in instabilities associated with a significantly higher final serpentinisation in slightly warmer regions of the kimberlite deposit. We conduct linear stability analysis of serpentinisation in an isolated volume of porous kimberlitic rocks saturated with water and an inert gas. There is a counteracting interplay between the heat release tending to destabilise the uniform distribution of parameters and the heat conduction tending to stabilise it by smoothing out temperature perturbations. We determine the critical spatial scale separating the parameters where one phenomenon dominates over another. The perturbations of longer-than-critical length grow, whereas the perturbations of shorter-than-critical length fade. The analytical results of the linear stability analysis are supported by direct numerical simulations using a full nonlinear model.
DS1983-0002
1983
Afanasev, B.P.Afanasev, B.P., Yangin, YU.T.Buried Primary Dispersion Streams of Kimberlite Bodies in The MalobuTo bin Skii Region.Geology And Geophysics, Vol. 24, No. 6, PP. 76-81.Russia, YakutiaGeochemistry, Sampling
DS0712-0471
2007
Afanasev, V.Izbekov, E., Podyachev, B., Afanasev, V.Signs of symmetric diamond concentration in the eastern Siberian Platform.Doklady Earth Sciences, Vol. 411, 9, pp. 1339-1340.RussiaDiamond genesis
DS0712-0472
2007
Afanasev, V.Izbekov, E., Podyachev, B., Afanasev, V.Signs of symmetric diamond concentration in the eastern Siberian Platform.Doklady Earth Sciences, Vol. 411, 9, pp. 1339-1340.RussiaDiamond genesis
DS0712-1018
2007
Afanasev, 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
DS0712-1019
2007
Afanasev, 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
DS1709-1981
2017
Afanasev, V.Egorova, E., Afanasev, V.Mineralogical features for determining age of kimberlites from Siberian craton by kimberlitic indicator minerals from placers. Mayat, Muna, Tychan, KenkemeGoldschmidt Conference, abstract 1p.Russia, Siberiageochemistry

Abstract: The history of kimberlite magmatism in the Siberian craton comprised the Middle Paleozoic (Late Devonian), Triassic, and Jurassic-Cretaceouse events. The Middle Paleozoic event produced greatest amounts of diamond-bearing kimberlites; diamond contents in the Triassic rocks are much lower, while the Jurassic-Cretaceous kimberlites are actually barren [1]. Minerals derived from kimberlites of different ages often coexist in placers and dispersion trains, which poses problems to the use of mineralogical methods for diamond exploration. The problem can be solved by knowing the morphological features of kimberlite indicator minerals typical of each magmatic event [2]. Garnets from Middle Paleozoic kimberlites have the following features: a) chemistry corresponding to diverse parageneses, including those of diamond assemblage; b) weak to strong wear; predominant medium and high wear degrees; c)signatures of dissolution in Late Devonian laterite weathering profiles. Garnets from Triassic kimberlites differ in a) lower paragenetic diversity; few or absent garnets of diamond assemblage; b) only low wear degree; strong wear restricted to garnets from Triassic kimberlites hosted by coastal sediments; c) no dissolution signatures. Jurassic-Cretaceous ages of kimberlites can be inferred from a) changes in paragenetic diversity as a result of deep metasomatism and predominance of shallow lherzolite varieties; no diamond assemblage garnets; b) weak wear; c) no dissolution signatures. The approach was used to estimate the ages of kimberlites in some kimberlite provinces. As a result, we inferred the existence of Middle Paleozoic kimberlites in the Kyutyungde graben, in the catchments of the Mayat, Billakh (Anabar area), and Muna rivers, in the MarkhaMorkoka interfluve, and in the Tychan diamond province (Krasnoyarsk region); Triassic kimberlites in the northern slope of the Olenek uplift and within the Bulkur uplift; and Late Jurassic-Early Cretaceous kimberlites in the Kenkeme catchment north of Yakutsk city.
DS0712-0473
2006
Afanasev, V.P.Izbekov, E.D., Podyachev, B.P., Afanasev, V.P.Signs of symmetric diamond concentration in the eastern Siberian platform.Doklady Earth Sciences, Vol. 411, 9, Nov-Dec. pp. 1339-1340.Russia, SiberiaDiamond genesis
DS0712-1022
2007
Afanasev, V.P.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
DS0812-0002
2008
Afanasev, V.P.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
DS0812-0798
2008
Afanasev, V.P.Nikolenko, E.I., Afanasev, V.P., Pokhilenko, N.P.Garnets of crustal parageneses in alluvial deposits of the eastern Siberian platform: genesis and search significance.Russian Geology and Geophysics, Vol. 49, pp. 655-666.Russia, YakutiaMuna Markha drainage
DS1012-0002
2009
Afanasev, V.P.Afanasev, V.P., Zinchuk, N.N., Logvinova, A.M.Distribution of placer diamonds related to Precambrian sources.Geology of Ore Deposits, Vol. 51, 8, pp. 675-683.RussiaAlluvials
DS1012-0541
2010
Afanasev, V.P.Nikolenko, E.I., Afanasev, V.P., Pokhilenko, N.P.Pecularities of the composition of zoned picroilmenites from the Massadou field, (Guinea) and Dachanya pipe ( Yakutia) kimberlites.Doklady Earth Sciences, Vol. 434, 2, pp.1386-1389.Africa, Guinea, RussiaGeochemistry - Massadou, Dachanaya
DS1012-0590
2010
Afanasev, V.P.Pokhilenko, N.P., Afanasev, V.P., Vavilov, M.A.Behaviour of kimberlite indicator minerals during the formation of mechanical dispersion halos in glacial settings.Lithology and Mineral Resources, Vol. 45, 4, pp. 324-329.Canada, Northwest TerritoriesDeposit - CL 25
DS1012-0741
2010
Afanasev, V.P.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
DS1112-0005
2011
Afanasev, V.P.Afanasev, V.P., Lobanov, S.S., Pokhilenko, N.P., Koptil, Mityukhin, Gerasimchuk, Pomazanski, GorevPolygenesis of diamonds in Siberian Platform. Five groups of diamonds have been distinquished.Russian Geology and Geophysics, Vol.l 52, pp. 259-274.Russia, SiberiaDiamond placers, alluvials
DS1212-0523
2012
Afanasev, V.P.Nikolenko, E., Afanasev, V.P., Chepurov, A.Fe rich ilmenite and kimberlite melt interaction, experimental researchs.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, Africa, Angola, GuineaDeposit - Dachnaya, Catoca, Massadon
DS1212-0562
2012
Afanasev, V.P.Pokhilenko, N.P., Afanasev, V.P., McDonald, J.A., Vavilov, M.A., Kulgin, S.S., Pokhilenko, L.N., Golovin, A.V., Agashev, A.M.Kimberlite indicator minerals in terrigene sediments of lower part of Mackenzie River Basin, NWT, Canada: evidence of new craton with thick lithosphere.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractCanada, Northwest TerritoriesGeochemistry - KIMS
DS1312-0649
2012
Afanasev, V.P.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
DS1412-0308
2014
Afanasev, V.P.Goryainov, S.V., Likhacheva, A.Y., Rashchenko, S.V., Shubin, A., Afanasev,V.P., Poikilenko, N.P.Raman identification of lonsdalaeite in Popigai impactites.Journal of Raman Spectroscopy, Vol. 45, 4, pp. 305-313.RussiaLonsdaleite
DS1612-2297
2016
Afanasev, V.P.Egorova, E.O., Afanasev, V.P., Pokhilenko, N.P.Middle Paleozoic kimberlite magmatism in the northeastern Siberia.Doklady Earth Sciences, Vol. 470, 2, pp. 1023-1026.Russia, SiberiaDeposit - Billyakh River placers

Abstract: The mineral chemistry and crystal morphology of kimberlite pyropes from the Billyakh River placer in the northeastern Siberian craton are characterised in terms of the placer history. The pyropes bear signatures of chemical weathering (dissolution), presumably in a Middle Paleozoic laterite profile, and therefore were originally hosted by Middle Paleozoic kimberlites. The broad occurrence of placer pyropes with lateritic dissolution signatures points to the presence of Middle Paleozoic diamond-bearing kimberlites in the study area.
DS1984-0001
1984
Afanasev, V.P.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
DS1984-0002
1984
Afanasev, V.P.Afanasev, V.P., Varlamov, V.A., Garanin, V.K.The Abrasion of Minerals in Kimberlites in Relation to the Conditions and Distances of Their Transportation.Soviet Geology And Geophysics, Vol. 25, No. 10, OCTOBER PP. 112-117.RussiaMorphology, Petrography
DS1985-0001
1985
Afanasev, V.P.Afanasev, V.P., Zinchuk, N.N., Boris, E.I.Characteristics of concentration of a kimberlite material inancient sedimentary deposits of Yakutia. (in Russian)Rudn. Spets. Osad. Form. Sib. Dalnego Vostoka, (in Russian), pp. 129-133RussiaBlank
DS1986-0473
1986
Afanasev, V.P.Kvasnitsa, V.N., Vuiki, V.I., Tsymbal, Yu.S., Afanasev, V.P., et al.Crystal morphology and paragenesis of cut garnets fromkimberlites.(Russian)Mineral. Zhurn., (Russian), Vol. 8, No. 1, pp. 30-44RussiaPyrope, Morphology
DS1987-0001
1987
Afanasev, V.P.Afanasev, V.P., Zinchuk, N.N.Minerogenesis of ancient placers of diamonds on the eastern edge of the Tunguska syncliseSoviet Geology and Geophysics, Vol. 28, No. 1, pp. 79-84RussiaPlacers, Genesis
DS1989-0007
1989
Afanasev, V.P.Afanasev, V.P.Technique for mapping of heavy mineral concentrate dispersion haloes In kimberlite bodiesSoviet Geology and Geophysics, Vol. 30, No. 5, pp. 32-37RussiaGeochemistry, Prospecting/sampling
DS1989-0008
1989
Afanasev, V.P.Afanasev, V.P.Prospecting based on heavy mineral seperates in the Yakutia Diamond bearing province.(Russian)Sov. Geol., (Russian), No. 1, pp. 24-33RussiaHeavy minerals, Prospecting
DS1991-0003
1991
Afanasev, V.P.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
DS1992-1446
1992
Afanasev, V.P.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
DS1993-1499
1993
Afanasev, V.P.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
DS1994-0012
1994
Afanasev, V.P.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
DS1995-2000
1995
Afanasev, V.P.Vishnevsky, S.A., Afanasev, V.P., Koptil, V.I.Impact diamonds : their features, origin and significanceProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 657-659.GlobalDiamonds -impact, Meteorites
DS1998-0008
1998
Afanasev, V.P.Afanasev, V.P., Zinchuk, N.N., Koptil, V.I.Diamond polygenesis: evidence for the native sources of placers of northeastern Siberian PlatformDoklady Academy of Sciences, Vol. 361A, No. 6, pp. 761-4.Russia, SiberiaAlluvials, placers, Genesis, origin
DS1999-0001
1999
Afanasev, V.P.Afanasev, V.P., Zinchuk, N.N.Main lithodynamic types of dispersion haloes of index kimberlite mineral sand environments of their formationGeo. Ore Dep., Vol. 41, No. 3, pp. 252-RussiaGeochemistry, Lithogeochemistry, indicator minerals
DS2000-0006
2000
Afanasev, V.P.Afanasev, V.P., Pokhilenko, Loginova, Zinchuk, EfimovaProblem of false kimberlite indicators: a new morphogenetic type Cr spinellide Diamondiferous areas.Russian Geology and Geophysics, Vol.41,12,pp.1676-89., Vol.41,12,pp.1676-89.RussiaGeochemistry - indicators, Chrome spinellide
DS2000-0007
2000
Afanasev, V.P.Afanasev, V.P., Pokhilenko, Loginova, Zinchuk, EfimovaProblem of false kimberlite indicators: a new morphogenetic type Cr spinellide Diamondiferous areas.Russian Geology and Geophysics, Vol.41,12,pp.1676-89., Vol.41,12,pp.1676-89.RussiaGeochemistry - indicators, Chrome spinellide
DS2001-0005
2001
Afanasev, V.P.Afanasev, V.P., Zinchuk, Pkhilenko, Krivonos, YanyginKarst role in the formation of diamond placers of the Muno Markhinskii interfluve Yakutsk diamond provinceGeol. Ore Depos., Vol. 43, No. 3, pp. 234-8.Russia, SiberiaAlluvials, Geomorphology
DS2002-1528
2002
Afanasev, V.P.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
DS1212-0678
2012
Afanasev, V.P.D.Smith, E.M., Kopylova, M.G., Nowell, G.M., Pearson, D.G., Ryder, J., Afanasev, V.P.D., Beeby, A.The contrast in trace element chemistry and volatile composition between fluid inclusions n fibrous and octahedral diamonds.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractCanada, Ontario, WawaDiamond inclusions
DS1212-0419
2012
Afanasev, Z.L.Lokhov, K., Lukyanova, L., Antonev, A.V., Polekhovsky, I.N., Antonov, A.V., Afanasev, Z.L., Bogomolov, E.S., Sergeev, S.A.U Pb and Lu-Hf isotopic systems in zircons and Hf-Nd isotopic systemization of the Kimozero kimberlites, Karelia.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, Archangel, Kola PeninsulaDeposit - Kimozero
DS1975-0905
1979
Afanaseyev, V.P.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
DS1991-0004
1991
Afanaseyev, V.P.Afanaseyev, V.P.Regularities of evolution of kimberlite minerals and their associations during formation of concentrate haloesSoviet Geology and Geophysics, Vol. 32, No. 3, pp. 78-84RussiaKimberlite geochemistry, Indicator mineralogy
DS0512-0036
2004
AfanasievAshchepkov, I.V., Vladykin, Rotman, Loginova, Afanasiev, Palessky, Saprykin, Anoshin, Kuchkin, KhmelnikovaMir and Internationalnaya kimberlite pipes - trace element geochemistry and thermobarometry of mantle minerals.Deep seated magmatism, its sources and their relation to plume processes., pp. 194-208.RussiaGeobarometry - Mir, International
DS0612-0047
2006
AfanasievAshchepkov, 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
DS0612-0048
2006
AfanasievAshchepkov, 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
DS1012-0016
2010
AfanasievAshchepkov, I., Afanasiev, Vladykin, Pokhilenko, Ntaflos, Travin, Ionov, Palessky, Logvinova, Kuligin, MityukhinReasons of variations of the mineral compositions of the mantle rocks beneath the Yakutian kimberlite province.International Mineralogical Association meeting August Budapest, abstract p. 141.Russia, YakutiaGeothermometry
DS0412-0004
2004
Afanasiev, V.Afanasiev, V., et al.Interpreting diamond morphology. The shape and surface features of diamonds are characteristic of primary deposits. Assist explRough Diamond Review, No. 5, June, pp.RussiaDiamond morphology, placers
DS0512-0003
2004
Afanasiev, V.Afanasiev, V.Surface modifications to diamonds often occur from damage due to alluvial transportation and from chemical attack after growth. These features can contribute to characterisationRough Diamond Review, No.7, December pp.Diamond morphology, placers, characteristics
DS0912-0163
2009
Afanasiev, V.De Stefano, A., Kopylova, M.C., Cartigny, P., Afanasiev, V.Diamonds and eclogites of the Jericho kimberlite ( Northern Canada).Contributions to Mineralogy and Petrology, Vol. 158, 3, Sept. pp. 295-315.Canada, NunavutDeposit - Jericho
DS1312-0006
2013
Afanasiev, V.Afanasiev, V., Agashev, A., Pokhilenko, N.Dispersion haloes of kimberlite indicator minerals in the Siberian Platform: history and formation conditions.Geology of Ore Deposits, Vol. 55, 4, pp. 256-264.RussiaMineral chemistry
DS1412-1007
2014
Afanasiev, V.Yelisseyev, A., Khrenov, A., Afanasiev, V., Pustavarov, V., Gromilov, S., Panchenko, A., Poikilenko, N., Litasov, K.Luminesence of impact diamonds from the Popigai astrobleme.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, SiberiaDiamond luminescence
DS1502-0036
2015
Afanasiev, V.Afanasiev, V., Ashchekov, I., Nikolenko, E.Concentrates and mantle xenocrysts from the Lao River Guinea and reconstruction of the mantle structure. Economic Geology Research Institute 2015, Vol. 17,, # 2484, 1p. AbstractAfrica, GuineaKimberlite dykes
DS1502-0087
2015
Afanasiev, V.Nikolenko, E., Tychkov, N., Afanasiev, V.Mantle xenocrysts of the Chompolo kimberlite field, Aldan shield, south Yakutia.Economic Geology Research Institute 2015, Vol. 17,, # 2471, 1p. AbstractRussiaDeposit - Chompolinskoe
DS1509-0439
2015
Afanasiev, V.Yelisseyev, A., Khrenov, A., Afanasiev, V., Pustovarov, V., Gromilov, S., Panchenko, A., Pokhilenko, N., Litasov, K.Luminescence of natural carbon nanomaterial: impact diamonds from the Popigai crater.Diamond and Related Materials, Vol. 58, pp. 69-77.RussiaDeposit - Popigai

Abstract: Impact diamonds (IDs) from the Popigai crater are aggregates of nanoparticulate graphite and cubic and hexagonal diamonds. IDs demonstrate broad-band emissions at 3.05, 2.8, 2.3 and 2.0 eV, which are associated with structural defects and are similar to those in detonation ultra-dispersed diamonds and CVD diamond films. A doublet with components at 1.7856 and 1.7892 eV in some ID samples is related to R1,2 lines of Cr3 + ions in corundum inclusions. The presence of N3, H3, NV0 and NV- vibronic systems in some of the ID samples shows that (i) there is nitrogen impurity and (ii) samples underwent high temperature annealing that promoted vacancies and nitrogen diffusion and defect aggregation. The luminescence decay fits with a sum of two exponential components: lifetime of the fast one is in the 5 to 9 ns range. Parameters of the traps responsible for broad thermoluminescence peaks at 148, 180, 276 and 383 K were estimated.
DS1705-0884
2017
Afanasiev, V.Ugapeva, S., Goryainov, S., Afanasiev, V., Ponkratov, K.Raman mapping of mechanical stress field in diamond around a chromite inclusion.European Geosciences Union General Assembly 2017, Vienna April 23-28, 1p. 11676 AbstractTechnologyDiamond inclusions
DS0912-0839
2009
Afanasiev, V.A.P.A.Yelisseyev, A.A.P.A., Afanasiev, V.A.P.A., Ikorsky, V.A.N.A.Magnetic susceptibility of natural diamonds.Doklady Earth Sciences, Vol. 425, 2, pp. 330-333.TechnologyDiamond morphology
DS0412-2181
2004
Afanasiev, V.P.Yelisseyev, A.P., Pokhilenko, N.P., Steeds, J.W., Zedgenizov, D.A., Afanasiev, V.P.Features of coated diamonds from the Snap Lake/King Lake kimberlite dyke, Slave Craton, Canada, as revealed by optical topographLithos, Vol. 77, 1-4, Sept. pp. 83-97.Canada, Northwest TerritoriesCoated diamonds, absorption, luminescence, nickel, nitr
DS0512-0004
2004
Afanasiev, V.P.Afanasiev, V.P., Griffin, W.L., Natapov, L.M., Zinchuk, N.N., Matukhin, R.G., Mikrtychiyan, G.A.Diamond prospects in the southwestern flank of the Tungusk synclise.Geology of Ore Deposits, Vol. 47, 1, pp. 45-62.Russia, YakutiaDaldyn, Tychany, geochemistry
DS1112-0006
2010
Afanasiev, V.P.Afanasiev, V.P., Tychkov, N.S., Pokhilenko, N.P., Ovchinnikov, Yu.I.About kimberlite indicator minerals in the Triassic tuffs of the Tunguska sineclise.Doklady Earth Sciences, Vol. 435, 2, pp. 1555-1559.RussiaDiamond exploration
DS1112-0536
2011
Afanasiev, V.P.Kopylova, M.G., Afanasiev, V.P., Bruce, L.F., Thurston, P.C., Tyder, J.Metaconglomerate preserves evidence for kimberlite Diamondiferous root and medium grade terrane of a pre-2.7 Ga Southern Superior protocraton.Earth and Planetary Science Letters, Vol. 312, 1-2, Dec. 1, pp. 213-235.Canada, OntarioMetaconglomerates
DS1212-0004
2012
Afanasiev, V.P.Afanasiev, V.P., Poikilenko, N.P.Abrasion of diamond: an experimental study and field evidence.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractRussia, YakutiaDiamond morphology
DS1212-0371
2012
Afanasiev, V.P.Kopylova, M.G., Miller, C., Afanasiev, V.P., Bruce, L., Thurston, P., Ryder, J.Kimberlite derived harzburgitic diamonds from a >2.7 GA southern Superior Province, Protocraton.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractCanada, Ontario, WawaDiamond morphology
DS1212-0679
2012
Afanasiev, V.P.Smith, E.M., Kopylova, M.G., Nowell, G.M., Pearson, D.G., Ryder, J., Afanasiev, V.P.The contrast in trace element chemistry and volatile composition between fluid inclusions in fibrous and octahedral diamonds.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractCanada, Ontario, WawaDiamond - inclusions
DS1212-0806
2012
Afanasiev, V.P.Yelisseyev, A.P., Afanasiev, V.P., Kopylova, M.G., Bulbak, T.A.The effect of metamorphic annealing and Betairradiation in optical properties of type 1AA diamonds.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractCanada, Ontario, RussiaDiamond - metamorphism
DS1312-0007
2013
Afanasiev, V.P.Afanasiev, V.P., Aschepkov, I.V., Verzhak, V.V., O'Brien, H., Palessky, S.V.PT conditions and trace element variations of picroilmenites and pyropes from placers and kimberlites in the Arkhangelsk region, NW Russia.Journal of Asian Earth Sciences, Vol. 70, pp. 45-63.Russia, Kola Peninsula, ArchangelDeposit - Verkhotinskoe , Kepinskoe fields
DS1312-0008
2013
Afanasiev, V.P.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
DS1312-0714
2013
Afanasiev, V.P.Pokhilenko, N.P., Afanasiev, V.P.New prospective for diamond deposits in Siberia.PDAC 2013, March 4, 1/2p. Abstract only as conflict in his scheduleRussiaOverview - Siberia
DS1312-0846
2013
Afanasiev, V.P.Smith, E.M., Kopylova, M.G., Frezzotti, M.L., Afanasiev, V.P.Nitrogen bubbles in the mantle: evidence from diamond inclusions.GAC-MAC 2013 SS4: Diamond: from birth in the mantle to emplacement in kimberlite, abstract onlyMantleDiamond inclusions
DS1312-0847
2013
Afanasiev, V.P.Smith, E.M., Kopylova, M.G., Frezzotti, M.L., Afanasiev, V.P.Diamond inclusions reveal fugitive mantle nitrogen.Goldschmidt 2013, AbstractMantleDiamond inclusions
DS1412-0695
2014
Afanasiev, V.P.Poikhilenko, N.P., Afanasiev, V.P., Agashev, A.M., Malkovets, V.G., Poikhilenko, L.N.New archean terranes with thick lithosphere of arctic regions of Siberia and North American ancient platforms: are they prospective for Diamondiferous kimberlites?30th. International Conference on Ore Potential of alkaline, kimberlite and carbonatite magmatism. Sept. 29-, Russia, CanadaKimberlite
DS1412-0696
2014
Afanasiev, V.P.Poikhilenko, N.P., Afanasiev, V.P., Poikhilenko, L.N.Polymict breccia xenolith from Noyabrskaya pipe.30th. International Conference on Ore Potential of alkaline, kimberlite and carbonatite magmatism. Sept. 29-, Russia, SiberiaDeposit - Noyabrskaya
DS1504-0219
2015
Afanasiev, V.P.Smith, E.M., Kopylova, M.G., Frezzotti, M.L., Afanasiev, V.P.Fluid inclusions in the Ebelyakh diamonds: evidence of CO2 liberation in eclogite and the effect of H2O on diamond habit.Lithos, Vol. 216-217, pp. 106-117.RussiaDeposit - Ebelyakh River
DS1606-1111
2016
Afanasiev, V.P.Samdanov, D.A., Afanasiev, V.P., Tychkov, N.S., Pokhilenko, N.P.Mineralogical zoning of the Diamondiferous areas: application experience of paragenetic analysis of garnets from kimberlites.Doklady Earth Sciences, Vol. 467, 1, pp. 228-231.Russia, YakutiaDeposit area - Muna-Markha

Abstract: Paragenetic analysis of pyropes from alluvial deposits of the Muna—Markha interfluve (Sakha-Yakutia Republic) made it possible to distinguish relatively uniform areas that are promising for the discovery of kimberlite bodies.
DS1608-1447
2016
Afanasiev, V.P.Ugapeva, S.S., Pavlushin, A.D., Goryainov, S.V., Afanasiev, V.P., Poikilenko, N.P.Comparative characteristics of diamonds with olivine inclusions from the Ebelyakh placer and kimberlite pipes of the Yakutian Diamondiferous province.Doklady Earth Sciences, Vol. 468, 1, pp. 473-477.RussiaDeposit - Mir, Aykhal, Udachnaya, XXII Congress

Abstract: The results of morphological examination and the character of the structural orientation and estimation of residual pressure calculated from spectra of combination dispersion in olivine inclusions within diamonds of the Ebelyakh placer and kimberlite pipes of the Yakutian Diamondiferous Province are presented. The data analysis aimed at revealing indications of similarity and/or differences between diamonds from the pipes and the placer. Differences in the structural orientation and spectra of combination dispersion of the inclusions of olivine in dodecahedroids of placers of the northeastern part of the Siberian Platform support the assumption of their non-kimberlite nature.
DS1702-0258
2016
Afanasiev, V.P.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.
DS1705-0892
2017
Afanasiev, V.P.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.
DS1804-0740
2018
Afanasiev, V.P.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.
DS1810-2325
2018
Afanasiev, V.P.Gromilov, S.A., Afanasiev, V.P., Poikhilenko. N.P.Moissanites of the Popigai astrobleme.Doklady Earth Sciences, Vol. 481, 2, pp. 997-999.Russiamoissanite

Abstract: Moissanites were found in tagamites of the Popigai meteorite crater along with impact diamonds. We have studied 55 samples including 49 individual polytypes and six intergrowths. The numbers of 6H, 15R, 4H, 6H/15R, and 6H/4H polytypes are 82, 7, 5, 4, and 2%, respectively. By the assemblage of polytypes, the moissanites of the Popigai astrobleme are distinct from kimberlite moissanites, as well as from synthetic SiC, which is characterized by the absence of the 4H polytype and the presence of more diverse inclusions (including Fe-bearing). The Popigai astrobleme is one of few objects with reliable natural moissanite. Technogenic contamination is excluded, since any researcher can find this mineral in tagamites.
DS1986-0495
1986
Afanasiev, V.P.Lipatova, V.A., Afanasiev, V.P.Mineralogical and palynological substantiation of the existence of remedial carboniferous intermediate reservoirs of kimberlite minerals in the northMalo-BotuobinskDoklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 288, No. 6, pp. 1453-1456RussiaBlank
DS1987-0002
1987
Afanasiev, V.P.Afanasiev, V.P., Zinchuk, N.N.Metallogeny of old diamond placers of eastern frame of theTunguskasyneclise.(Russian)Geol. Geofiz.(Russian), No. 1, January ppRussiaBlank
DS1995-0008
1995
Afanasiev, V.P.Afanasiev, V.P.Geological mineralogical system of searching for diamond depositsProceedings of the Sixth International Kimberlite Conference Extended Abstracts, pp. 1-3.Russia, Siberia, YakutiaHalo identification, Indicator minerals
DS1995-2149
1995
Afanasiev, V.P.Zinchuk, N.N., Afanasiev, V.P.Genetic types and main tendencies for Diamondiferous placers formationProceedings of the Sixth International Kimberlite Conference Almazy Rossii Sakha abstract, p. 36.Russia, YakutiaPlacers, alluvials, Deposit -Siberian Platform
DS1998-0009
1998
Afanasiev, V.P.Afanasiev, V.P., Pokhilenko, N.P., Logvinova, A.M.Problem of false indicators for kimberlites and lamproites ( on the exampleof chromites).7th International Kimberlite Conference Abstract, pp. 7-8.Russia, Yakutia, ArkangelskMineralogy - chromium spinels
DS2003-1083
2003
Afanasiev, V.P.Pkhilenko, N.P., Zedgenizov, D.A., Afanasiev, V.P., Rylov, G.M., Milledge, H.J.Morphology and internal structure of diamonds from Snap Lake, King Lake kimberlite8ikc, Www.venuewest.com/8ikc/program.htm, Session 3, POSTER abstractNorthwest TerritoriesDiamonds - morphology, Deposit - Snap Lake, King Lake
DS1986-0263
1986
Afanasjev, V.P.Garanin, V.K., Kudryavtseva, G.P., Posukhova, T.V., Afanasjev, V.P.Morphology of kimberlite minerals: its usage for predicting and searchingfor diamond depositsProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 457-459RussiaDiamond exploration
DS1803-0431
2017
Afanasyev, A.A.Afanasyev, A.A., Belyaeva, E.A.The stability of serpentization due to water flow in kimberlite.Journal of Appled Mathematics and Mechanics, Vol. 81, pp. 206-213.Russiadeposit - Mir

Abstract: A linear analysis of the stability of the course of serpentization, that is, of the exothermic hydration reaction, due to the flow of water in a kimberlite pipe is carried out, taking both the heat conduction and the convective heat transfer by the fluid saturating the pipe rocks into account. It is shown that two different serpentization processes exist: a homogeneous process and an inhomogeneous process associated with a loss of stability by the homogeneous process and a non-uniform reaction rate distribution. Dimensionless similarity parameters that determine the course of the reaction are proposed. It is shown that convective heat transfer promotes a stabilization of the flow and the formation of a homogeneous serpentinite distribution. Other conditions being equal, an increase in the convective heat flux leads to an increase in the wavelengths of the unstable perturbations and to a decrease in their amplitude. A critical value of the flow rate exists, and, when this is exceeded, instability does not develop and serpentinization takes place under homogeneous conditions.
DS1960-1058
1969
Afanasyev, G.D.Afanasyev, G.D., et al.Eclogite of the Front Range, Northern CaucasusDoklady Academy of Science USSR, Earth Science Section., Vol. 187, No. 1-6, PP. 164-166.RussiaKimberlite
DS1312-0995
2013
Afanasyev, V.Yelisseyev, A., Meng, G.S., Afanasyev, V., Pokhilenko, N., Pustovarov, V., Isakova, A., Lin, Z.S, Lin, H.Q.Optical properties of impact diamonds from the Popigai astroblemes.Diamond and Related Materials, Vol. 37, pp. 8-16.Russia, SiberiaMeteortic diamonds
DS0912-0003
2009
Afanasyev, V.P.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
DS1812-2901
2018
Afanasyev, V.P.Yelisseyev, A.P., Afanasyev, V.P., Gromilov, S.A.Yakutites from the Popigai meteorite crater.Diamond & Related Materials, Vol. 89, pp. 10-17.Russiameteorite

Abstract: For the first time, 60 large diamond aggregates were found inside the Popigai meteorite crater during washing of alluvial deposits along the Dogoi river crossing the crater. These aggregates are similar in appearance to yakutites from the placers of Northern Yakutia (YPY), and we regard them as yakutites from the Popigai crater (YPC). The structure and optical properties of Popigai impact diamonds from the impact melt rocks (tagamites) in the crater (PIDT) and yakutites YPC/YPY were compared in detail. In all these cases, a polycrystalline structure consisting of nanoscale grains of cubic and twinned cubic diamond (lonsdaleite) was found. This is the result of a solid-phase graphite-diamond transition due to an impact event 35?million?years ago. The diamond aggregates show the following features: a red shift of the short-wave edge of the transmission, broadening of the diamond Raman peaks, signals from other diamond polytypes and numerous inclusions of other minerals in the Raman spectra, and a dominant broadband photoluminescence (PL). PL in the N3 system associated with N3V centers in PIDT diamonds indicates a high-temperature annealing of these aggregates with resulting aggregation of impurities during the prolonged cooling of large impact melt pockets and pools. It is assumed that some of the impact diamonds were ejected from the crater during the impact event and experienced rapid cooling. Some of these diamonds fell back into the crater (YPC yakutites), others have been deposited outside the crater and displaced during erosion (YPY yakutites). Difference in size and shape between the PIDTs and yakutites YPC/YPY is due to the difference in size of original graphite flakes or aggregates and/or due to the fundamentally different technologies of diamond extraction.
DS1970-0859
1974
Afanasyev, V.P.Afanasyev, V.P., Ivaniv, I.N., Koptil, V.I., Kharkiv, A.D.Typomorphism of Diamonds from Kimberlite Veins and the Possible Bed Rock Sources of Diamond Bearing Placers in Northwestern Yakutia.Doklady Academy of Science USSR, Earth Science Section., Vol. 214, No. 1-6, PP. 154-157.Russia, West Africa, GuineaMineralogy, Genesis
DS1981-0002
1981
Afanasyev, V.P.Afanasyev, V.P., et al.On the In homogeneity of Chrome Bearing Ilmenite from the Zimnyaya Kimberlite Pipe and its Genetic Significance.Geol. Rudn. Mestorozhd., Vol. 23, No. 2, PP. 44-57.RussiaPetrography
DS1986-0002
1986
Afanasyev, V.P.Afanasyev, V.P.The mechanical wear of kimberlite minerals as shown by thinsections.(Russian)Soviet Geology (Russian), No. 10, pp. 81-87RussiaWeathering, Kimberlite
DS1986-0003
1986
Afanasyev, V.P.Afanasyev, V.P., Gerasimov, A.Yu., Babenko, V.V.Self-limitation of picroilmenite during reduction processes as a resultof anistropy of the mechanicalproperties.(Russian)In: Mineralogical crystallography and its application to mineral, pp. 159-163RussiaMineralogy, Picroilmenite
DS1986-0004
1986
Afanasyev, V.P.Afanasyev, V.P., Sibertsev, Y.M., Yegorov, A.Y.Minerals from kimberlites in ancient littoral reservoir rocks. (Russian)Izv. Vysshikh Uchn. Zaved. Geol. I Razveda (Russian), Vol. 2, pp. 48-54RussiaPetrology, Mineral chemistry
DS1986-0435
1986
Afanasyev, V.P.Kharkiv, A.D., Afanasyev, V.P., Zinchuk, N.N.Mineralogical mapping of potential diamond territories; basic method For the exploration of diamond deposits.(Russian)In: Mineralogical crystallography and its application mineral, pp. 30-37RussiaOre guides
DS1987-0417
1987
Afanasyev, V.P.Lipitova, V.A., Afanasyev, V.P.Mineralogic and playnologic proof of the Pre-middle Carboniferous age of intermediate kimberlitic mineral reservoirs in the northern part of the MalayaDoklady Academy of Science USSR, Earth Science Section, Vol. 288, No. 1-6, pp. 102-105RussiaBlank
DS1988-0002
1988
Afanasyev, V.P.Afanasyev, V.P., Babenko, V.V.Migration properties of kimberlite mineralsDokl. Acad. Sciences USSR Earth Science Section, Vol. 303, No. 6, pp. 141-144RussiaAlluvials, Modeling, kimberlite miner
DS1988-0003
1988
Afanasyev, V.P.Afanasyev, V.P., Babenko, V.V.Migration properties of kimberlite minerals.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 303, No. 3, pp. 714-718RussiaMineralogy, Migration
DS1988-0708
1988
Afanasyev, V.P.Tsyganov, V.A., Zincguk, N.N., Afanasyev, V.P.Problem of evaluating a general population from non-random samples (as exemplified by the indicator properties of kimberlites)Doklady Academy of Science USSR, Earth Science Section, Vol. 301, No. 4, July-Aug, pp. 74-78RussiaSampling, Kimberlite minerals
DS1993-0010
1993
Afanasyev, V.P.Afanasyev, V.P., Tsyganov, V.A., Choumirin, K.G.Methods of qualitative and quantitative processing and interpretation of heavy mineral data.Diamonds of Yakutia, Russia, Volume $ 115.00 Can., pp. 53-56.Russia, YakutiaMineralogy, Heavy minerals
DS1994-1654
1994
Afanasyev, V.P.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
DS1996-0007
1996
Afanasyev. V.P., et al.Afanasyev. V.P., et al.Relative abrasion resistance of pyrope and picroilmenite, two indicator minerals in kimberlite.Doklady Academy of Sciences, Vol. 342 No. 4, May, pp. 93-97.Russia, AlgeriaGeochemistry, Deposit - Malaya Botuobaya, Kyutyungda, Dyukunnakh
DS0412-1881
2003
Afanesev, V.P.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
DS2003-1315
2003
Afanesev, V.P.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
DS0612-0046
2005
AfansievAshchepkov, I.V., Vladykin, Rotman, Afansiev, Loginova, Kuchkin, Palessky, Nikolaeva, Saprykin, AnoshinVariations of the mantle mineralogy and structure beneath Upper - Muna kimberlite field.Problems of Sources of Deep Magmatism and Plumes., pp. 170-187.RussiaMineralogy
DS0812-0051
2008
AfansievAshchepkov, I.V., Pokhilenko, Vladykin, Rotam, Afansiev, Logvinova, Kostrovitsky, Karpenko, KuliginReconstruction of mantle sections beneath Yakutian kimberlite pipes using monomineral thermobaraometry.Geological Society of London, Special Publication, SP 293, pp. 335-352.RussiaGeothermometry
DS0812-0052
2007
AfansievAshchepkov, I.V., Vladykin, Pkhilenko, Logvinova, Palessky, Afansiev, Alymova, Stegnitsky, Khmelnikova RotamanVariations of ilmenite compositions from Yakutian kimberlites and the problem of their origin.Vladykin Volume 2007, pp. 71-89.Russia, YakutiaIlmenite, kimberlite
DS0812-0053
2008
AfansievAshchepkov, Pokhilenko, Vladykon, Loginova, Rotman, Afansiev, Kuligin, Malygina, Alymova, Stegnitsky, KhmetnikovaPlume interaction and evolution of the continental mantle lithosphere.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., 2008 pp. 104-121.MantlePlume
DS1012-0018
2010
AfansievAshchepkov, I.V., Pokhilenko, Vladykin, Logvinova, Afansiev, Kuligin, Malygina, Alymova, KostrovitskyStructure and evolution of the lithospheric mantle beneath Siberian Craton, theromobarometric study.Tectonophysics, Vol. 485, pp. 17-41.RussiaGeothermometry
DS1012-0017
2010
Afansiev, V.Ashchepkov, I., Pokhienko, N., Afansiev, V., Logvinova, A., Pokhienko, L.I., Ntaflos, Ionov, Kuligin, MityukhinMonomineral thermobarometry for the diamond inclusions from Siberia: genetic links.International Mineralogical Association meeting August Budapest, abstract p. 184.RussiaThermobarometry - Mir, Alakite
DS0612-0045
2005
Afansiev, V.P.Ashchepkov, I.V., Vladykin, N.V., Pokhilenko, N.P., Rotman, A.Y., Afansiev, V.P., Logvinova, A.M.Using the monomineral thermobarometry for the reconstruction of the mantle sections.Problems of Sources of Deep Magmatism and Plumes., pp. 210-228.MantleGeothermometry
DS1112-0537
2011
Afansiev, V.P.Kopylova, M.G., Afansiev, V.P., Bruce, L., Ryder, J.Diamondiferous conglomerate preserves evidence for kimberlite and the deep cratonic root of the Mesoarchean southern Superior Craton.Goldschmidt Conference 2011, abstract p.1221.Canada, OntarioWawa
DS1112-0538
2011
Afansiev, V.P.Kopylova, M.G., Afansiev, V.P., Bruce, L.F., Ryder, J.Diamond exploration in orogenic settings: lessons from Wawa metaconglomerate.Yellowknife Geoscience Forum Abstracts for 2011, abstract p. 52-53.Canada, Ontario, WawaHeavy minerals
DS1412-0851
2014
Afansiev, V.P.Smith, E.M., Kopylova, M.G., Frezzotti, M.L., Afansiev, V.P.N-rich fluid inclusions in octahedrally-grown diamond.Earth and Planetary Science Letters, Vol. 393, pp. 39-48.Canada, Ontario, WawaDiamond inclusions
DS1610-1919
2016
Afansiev, V.P.Yelisseyev, A.P., Afansiev, V.P., Panchenko, A.V., Gromilov, S.A., Kaichev, V.V., Sarasev, A.A.Yakutites: are they impact diamonds from the Popigai crater?Lithos, in press available 14p.RussiaImpact diamonds

Abstract: Yakutites are coarse (up to 15 mm or larger) aggregates dispersed for more than 500 km around the Popigai meteorite crater. They share many features of similarity with impact diamonds found inside the crater, in elemental and phase compositions, texture, and optical properties as revealed by X-ray photoelectron spectroscopy, X-ray diffraction, and optical spectroscopy (Raman, absorption, luminescence and microscopic) studies. The N3 vibronic system appearing in the luminescence spectra of Popigai impact diamonds (PIDs) indicates a presence of nitrogen impurity and a high-temperature annealing of diamonds that remained in the crater after solid-phase conversion from graphite. Yakutites lack nitrogen-vacancy centers as signatures of annealing, which may indicate quenching at the time of ejection. Thus, both PIDs and yakutites originated during the Popigai impact event and yakutites were ejected to large distances.
DS1994-0957
1994
Afansiev, V.P.Kryuchkov, A.I., Leliukh, M.J., Krasinets, S.S., Afansiev, V.P.Two unusual Paleozoic kimberlite diatremes in the Daldyn-Alakit region Of the Siberian PlatformProceedings of Fifth International Kimberlite Conference, Vol. 1, pp. 34-39.Russia, SiberiaDaldyn-Alakit, Kimberlite diatremes
DS1998-1382
1998
Afasev, V.P.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
DS1988-0709
1988
Afasyev, P.Tsyganov, V.A., Zinchuk, N.N., Afasyev, P., Ovichinnikov, L.N.Express estimation of open and semi-open regions with complexTheory Practice of Geoch. Explor.Modern Conditions, IV All Union Meet, Vol. 7, pp. 140-141. (Russian)RussiaGeochemistry, Kimberlites
DS1988-0390
1988
Afasyev, V.P.Kvasnitsa, V.N., Krochuk, m V.M., Afasyev, V.P., Tsymbal, Yu.S.Crystal morphology of kimberlite chrome spinel.(Russian)Mineral. Zhurn., (Russian), Vol. 10, No. 3, June pp. 45-51RussiaMineralogy, Spinel
DS0712-0242
2006
Affaton, P.Deynoux, M., Affaton, P., Trompette, R., Villeneuve, M.Pan-African tectonic evolution and glacial events registered in Neoproterozoic to Cambrian cratonic and foreland basins of West Africa.Journal of African Earth Sciences, Vol. 46, 5, Dec. pp. 397-426.Africa, West AfricaTectonics
DS1212-0534
2012
Affaton, P.Owona, S., Tichomirowa, M., Ratschbacher, L., Ondoa, J.M., Youmen, D., Pfander, J., Tchoua, F.M., Affaton, P., Ekodeck, G.E.New igneous zircon Pb/Pb and metamorphic Rb/Sr ages in the Yaounde Group, Cameroon, Central Africa): implications for the Central African fold belt evolution close to the Congo Craton.International Journal of Earth Sciences, Vol. 101, 7, pp. 1689-1703.Africa, CameroonGeochronology
DS1212-0535
2012
Affaton, P.Owona, S., Tichomirowa, M., Ratschbacher, L., Ondoa, W.J., Youmen, D., Pfander, J., Tchoua, F.M., Affaton, P., Ekodeck, G.E.New igneous zircon Pb/Pb and metamorphic Rb/Sr ages in the Yaounde Group ( Cameron, Central Africa): implications for the Central African fold belt evolution close to the Congo Craton.International Journal of Earth Sciences, Vol. 101, pp. 1689-1703.Africa, CameroonGeochronology
DS1995-0009
1995
Affaton, P.Affaton, P., Trompette, R., Uhlein, A., Boudzoumou, F.The Panafrican Brasiliano Aracuai West Congo fold belt in the framework Of western Gondwana aggregation 600MaGeological Society Africa 10th. Conference Oct. Nairobi, p. 20. AbstractWest Africa, BrazilTectonics, Rodinia Supercontinent
DS1997-0050
1997
Affaton, P.Attoh, K., Dallmeyer, R.D., Affaton, P.Chronology of nappe assembly in the Pan-African Dahomeyide orogen, WestAfrica: evidence from 40 Ar 39Precambrian Research, Vol. 82, No. 1-2, March pp. 153-172West Africa, GhanaGeochronology, Orogeny
DS0512-0005
2005
AfgemAfgemThe new Afgem.... overview of company, Rex and three kimberlite mines.Mineweb, August 21, 2p.Africa, South AfricaNews item - Rex
DS1988-0367
1988
Afilaka, J.O.Kogbe, C.A., Afilaka, J.O.Review of Africa's solid mineral resource potentialJournal of African Earth Sciences, Vol. 7, No. 3, pp. 589-600AfricaDiamonds pp. 597-598. chart p. 599, Brief description
DS1506-0271
2015
Afiri, A.Gueydan, F., Pitra, P., Afiri, A., Poujol, M., Essaifi, A., Paquette, J-L.Oligo-Miocene thinning of the Beni Bousera peridotites and their Variscan crustal host rocks, Internal Rif, Morocco.Tectonics, Vol. 34, pp.1244-1268.Africa, MoroccoPeridotite
DS0512-0006
2005
Afonso, J.C.Afonso, J.C., Ranali, G., Fernandez, M.Thermal expansivity and elastic properties of the lithospheric mantle: results from mineral physics of composites.Physics of the Earth and Planetary Interiors, Vol. 149, 3-4, April 15, pp. 279-306.MantleGeothermometry
DS0912-0266
2009
Afonso, J.C.Griffin, W.L., Begg, G., O'Reilly, S.Y., Afonso, J.C.Paleo-Archean generation of the continental lithosphere.Goldschmidt Conference 2009, p. A466 Abstract.MantleKimberlite xenoliths
DS0912-0268
2009
Afonso, J.C.Griffin, W.L., O'Reilly, S.Y., Afonso, J.C., Begg, G.C.The composition and evolution of lithospheric mantle: a re-evaluation and its tectonic implications.Journal of Petrology, Vol. 50,no. 7,. pp. 1185-1204.MantleTectonics
DS1012-0003
2010
Afonso, J.C.Afonso, J.C., Ranalli, G., Fernandez, M., Griffin, W.L., O'Reilly, S.Y., Faul, U.On the VpVs-Mg# correlation in mantle peridotites: implications for the identification of thermal and compositional anomalies in the upper mantle.Earth and Planetary Science Letters, Vol. 289, 3-4, pp. 606-618.MantleChemistry
DS1012-0197
2010
Afonso, J.C.Fernadez, M., Afonso, J.C., Ranalli, G.The deep lithospheric structure of the Namibian volcanic margin.Tectonophysics, Vol.481, 1-4, pp. 68-81.Africa, NamibiaTectonics
DS1112-0481
2011
Afonso, J.C.Jemenez-Munt, I., Fernandez, M., Verges, J., Garcia-Castellanos, D., Fullea, J., Perez-Gussinye, M., Afonso, J.C.Decoupled crust mantle accommodation of Africa-Eurasia convergence in the NW Moroccan margin.Journal of Geophysical Research, Vol. 116, B08403, 12p.Africa, MoroccoGeophysics - density
DS1312-0009
2013
Afonso, J.C.Afonso, J.C., Fullea, J., Connolly, J., Rawlinson, N., Yang, Y., Jones, A.G.Multi observable thermochemical tomography: a new framework in integrated studies of the lithosphere.Goldschmidt 2013, AbstractMantleGeothermometry
DS1606-1090
2016
Afonso, J.C.Griffin, W.L., Afonso, J.C., Belousova, E.A., Gain, S.E., Gong, X-H., Gonzalez-Jiminez, J.M., Howell, D., Huang, J-X., McGowan, N., Pearson, N.J., Satsukawa, T., Shi R., Williams, P., Xiong, Q., Yang, J-S., Zhang, M., O'Reilly, S.Y.Mantle recycling: transition zone metamorphism of Tibetan ophiolitic peridotites and its tectonic implications.Journal of Petrology, in press available, 30p.Asia, China, TibetPeridotite

Abstract: Large peridotite massifs are scattered along the 1500?km length of the Yarlung-Zangbo Suture Zone (southern Tibet, China), the major suture between Asia and Greater India. Diamonds occur in the peridotites and chromitites of several massifs, together with an extensive suite of trace phases that indicate extremely low fO2 (SiC, nitrides, carbides, native elements) and/or ultrahigh pressures (UHP) (diamond, TiO2 II, coesite, possible stishovite). New physical and isotopic (C, N) studies of the diamonds indicate that they are natural, crystallized in a disequilibrium, high-T environment, and spent only a short time at mantle temperatures before exhumation and cooling. These constraints are difficult to reconcile with previous models for the history of the diamond-bearing rocks. Possible evidence for metamorphism in or near the upper part of the Transition Zone includes the following: (1) chromite (in disseminated, nodular and massive chromitites) containing exsolved pyroxenes and coesite, suggesting inversion from a high-P polymorph of chromite; (2) microstructural studies suggesting that the chromitites recrystallized from fine-grained, highly deformed mixtures of wadsleyite and an octahedral polymorph of chromite; (3) a new cubic Mg-silicate, with the space group of ringwoodite but an inverse-spinel structure (all Si in octahedral coordination); (4) harzburgites with coarsely vermicular symplectites of opx + Cr-Al spinel ± cpx; reconstructions suggest that these are the breakdown products of majoritic garnets, with estimated minimum pressures to?>?13?GPa. Evidence for a shallow pre-metamorphic origin for the chromitites and peridotites includes the following: (1) trace-element data showing that the chromitites are typical of suprasubduction-zone (SSZ) chromitites formed by magma mixing or mingling, consistent with Hf-isotope data from magmatic (375?Ma) zircons in the chromitites; (2) the composition of the new cubic Mg-silicate, which suggests a low-P origin as antigorite, subsequently dehydrated; (3) the peridotites themselves, which carry the trace element signature of metasomatism in an SSZ environment, a signature that must have been imposed before the incorporation of the UHP and low-fO2 phases. A proposed P-T-t path involves the original formation of chromitites in mantle-wedge harzburgites, subduction of these harzburgites at c. 375?Ma, residence in the upper Transition Zone for >200 Myr, and rapid exhumation at c. 170-150?Ma or 130-120?Ma. Os-isotope data suggest that the subducted mantle consisted of previously depleted subcontinental lithosphere, dragged down by a subducting oceanic slab. Thermomechanical modeling shows that roll-back of a (much later) subducting slab would produce a high-velocity channelized upwelling that could exhume the buoyant harzburgites (and their chromitites) from the Transition Zone in?
DS1709-1998
2017
Afonso, J.C.Henry, H., Afonso, J.C., Satsukawa, T., Griffin, W.L., O'Reilly, S.Y., Kaczmarek, M-A., Tilhac, R., Gregoire, M., Ceuleneer, G.The unexplored potential impact of pyroxenite layering on upper mantle seismic properties.Goldschmidt Conference, abstract 1p.Europe, Spain, United States, Californiageophysics - seismics

Abstract: It is now accepted that significant volumes of pyroxenites are generated in the subduction factory and remain trapped in the mantle. In ophiolites and orogenic massifs the geometry of pyroxenite layers and their relationships with the host peridotite can be observed directly. Since a large part of what is known about the upper mantle structure is derived from the analysis of seismic waves, it is crucial to integrate pyroxenites in the interpretations. We modeled the seismic properties of a peridotitic mantle rich in pyroxenite layers in order to determine the impact of layering on the seimsic properties. To do so, EBSD data on deformed and undeformed pyroxenites from the Cabo Ortegal complex (Spain) and the Trinity ophiolite (California, USA) respectively are combined with either A or B-type olivine fabrics in order to model a realistic pyroxenite-rich upper mantle. Consideration of pyroxeniterich domains within the host mantle wall rock is incorporated in the calculations using the Schoenberg and Muir group theory [1]. This quantification reveals the complex dependence of the seismic signal on the deformational state and relative abundance of each mineral phase. The incorporation of pyroxenites properties into geophysical interpretations in understanding the lithospheric structure of subduction zones will lead to more geologically realistic models.
DS1801-0017
2017
Afonso, J.C.Giuliani, A., Campeny, M., Kamenetsky, V.S., Afonso, J.C., Maas, R., Melgarejo, J.C., Kohn, B.P., Matchen, E.L., Mangas, J., Goncalves, A.O., Manuel, J.Southwestern Africa on the burner: Pleistocene carbonatite volcanism linked to deep mantle upwelling in Angola.Geology, Vol. 45, 11, pp. 971=974.Africa, Angolacarbonatite - Catanda

Abstract: The origin of intraplate carbonatitic to alkaline volcanism in Africa is controversial. A tectonic control, i.e., decompression melting associated with far-field stress, is suggested by correlation with lithospheric sutures, repeated magmatic cycles in the same areas over several million years, synchronicity across the plate, and lack of clear age progression patterns. Conversely, a dominant role for mantle convection is supported by the coincidence of Cenozoic volcanism with regions of lithospheric uplift, positive free-air gravity anomalies, and slow seismic velocities. To improve constraints on the genesis of African volcanism, here we report the first radiometric and isotopic results for the Catanda complex, which hosts the only extrusive carbonatites in Angola. Apatite (U-Th-Sm)/He and phlogopite 40Ar/39Ar ages of Catanda aillikite lavas indicate eruption at ca. 500-800 ka, more than 100 m.y. after emplacement of abundant kimberlites and carbonatites in this region. The lavas share similar high-µ (HIMU)-like Sr-Nd-Pb-Hf isotope compositions with other young mantle-derived volcanics from Africa (e.g., Northern Kenya Rift; Cameroon Line). The position of the Catanda complex in the Lucapa corridor, a long-lived extensional structure, suggests a possible tectonic control for the volcanism. The complex is also located on the Bié Dome, a broad region of fast Pleistocene uplift attributed to mantle upwelling. Seismic tomography models indicate convection of deep hot material beneath regions of active volcanism in Africa, including a large area encompassing Angola and northern Namibia. This is strong evidence that intraplate late Cenozoic volcanism, including the Catanda complex, resulted from the interplay between mantle convection and preexisting lithospheric heterogeneities.
DS0912-0235
2009
Afonso, L.A.D.Fullea, J.J.C., Afonso, L.A.D., Connolly, M., et al.LitMod3D: an interactive 3-D software to model the thermal, compositional, density, seismological, and rheological structure of the lithosphere and sublithosGeochemistry, Geophysics, Geosystems: G3, Vol. 10, QO8019TechnologyModels
DS1997-0008
1997
Africa FocusAfrica FocusHandbook og African stock exchangesAfrica Focus, $ 40.00 United StatesAfricaLegal - stock exchanges, Book - ad
DS1012-0004
2010
African AnalystAfrican AnalystBreaking the curse... a case for transparent taxation.African Analyst, Vol. 5, 1, pp. 34-52.AfricaEconomics - taxation
DS1994-0013
1994
African Conference Mining InvestmentAfrican Conference Mining InvestmentANGOLA. #1African Conference Mining Investment, June 8-9, 32p.AngolaCountry profile, Diamond production
DS1994-0014
1994
African Conference Mining InvestmentAfrican Conference Mining InvestmentBOTSWANA, 1994; African Conference Mining InvestmentAfrican Conference Mining Investment, June 8-9, 20p.BotswanaCountry profile, Diamond production
DS1994-0015
1994
African Conference Mining InvestmentAfrican Conference Mining InvestmentGHANAAfrican Conference Mining Investment, June 8-9, 36p.GhanaCountry profile, Diamond production
DS1994-0016
1994
African Conference Mining InvestmentAfrican Conference Mining InvestmentIVORY COASTAfrican Conference Mining Investment, June 8-9, 10p.GlobalCountry profile, Diamond production
DS1994-0017
1994
African Conference Mining InvestmentAfrican Conference Mining InvestmentBURKin a FASO. (in French)African Conference Mining Investment, June 8-9, 13p.GlobalCountry profile, Diamond production
DS1994-0018
1994
African Conference Mining InvestmentAfrican Conference Mining InvestmentMali Africa project planned...Niger River south.African Conference Mining Investment, June 8-9, 34p.GlobalCountry profile, Diamond production
DS1994-0019
1994
African Conference Mining InvestmentAfrican Conference Mining InvestmentGUINEA. (in French)African Conference Mining Investment, June 8-9, 18p.GuineaCountry profile, Diamond production
DS1994-0020
1994
African Conference Mining InvestmentAfrican Conference Mining InvestmentNAMIBIA (1994)African Conference Mining Investment, June 8-9, 4p.NamibiaCountry profile, Diamond production
DS1994-0021
1994
African Conference Mining InvestmentAfrican Conference Mining InvestmentSIERRA LEONE 1994African Conference Mining Investment, June 8-9, 18p.Sierra LeoneCountry profile, Diamond production
DS1994-0022
1994
African Conference Mining InvestmentAfrican Conference Mining InvestmentTANZANIA (1994)African Conference Mining Investment, June 8-9, 24p.TanzaniaCountry profile, Diamond production
DS1994-0023
1994
African Conference Mining InvestmentAfrican Conference Mining InvestmentZAMBIAAfrican Conference Mining Investment, June 8-9, 36p.ZambiaCountry profile
DS1994-0024
1994
African Conference Mining InvestmentAfrican Conference Mining InvestmentZIMBABWEAfrican Conference Mining Investment, June 8-9, 10p.ZimbabweCountry profile, Diamonds
DS2002-0009
2002
African ExchangeAfrican ExchangeTrends in mining laws and regulation among the developing nationsAfrican Exchange, Feb. pp. 53-55.AfricaList of countries, taxes, law, legal
DS1991-1183
1991
Aftab Khan, M.Moon, C.J., Aftab Khan, M.Mineral exploration... review in various countriesMining Annual Review, June 1991, pp. 175-195GlobalMineral exploration, Review 1990
DS1992-0009
1992
Aftab Khan, M.Aftab Khan, M., Maguire, P.K.H., Swain, C.J.Geophysical models of the Kenya riftTectonophysics, Vol. 209, pp. 209-211. Extended abstractEast Africa, KenyaTectonics, Geophysics -gravity, seismics
DS1984-0473
1984
Agafanov, L.V.Makeev, A.B., Agafanov, L.V., Goncharenko, A.I.The Relation of the Chemical Composition to the Physical Properties of Chrome Spinels in Alpinotypic Ultrabasites.Soviet Geology And Geophysics, Vol. 25, No. 2, PP. 125-129.RussiaMineral Chemistry
DS1312-0154
2013
Agafonov, L.V.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
DS1975-0001
1975
Agafonov, L.V.Agafonov, L.V., et al.Deep Seated Inclusions in Alkalic Basaltoids of the Shavaryin Tsaram Pipe, Mongolian People's Republic.Doklady Academy of Science USSR, Earth Science Section., Vol. 224, No. 1-6, PP. 130-132.RussiaKimberlite, Pyrope
DS0712-0223
2007
Agafonov, V.Davydov, V.A., Rakhmanina, A.V., Rols, S., Agafonov, V., Pulikkathara, M.X., Wal, R.V., Khabashesku, V.N.Size dependent phase transition of diamond to graphite at high pressures.Journal of Physical Chemistry , Vol. 111, no. 35, pp. 12918-12925. Ingenta 1074185621TechnologyUHP
DS1012-0744
2010
Agakhanov, A.A.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
DS1904-0763
2019
Agangi, A.Olierook, H.K.H., Agangi, A., Plavsa, D., Reddy, S.M., Yao, W., Clark, C., Occipinti, S.A., Kylander-Clark, A.R.C.Neoproterozoic hydrothermal activity in the west Australian craton related to Rodinia assembly or breakup?Gondwana Research, Vol 68, 1, pp. 1-12.Australiacraton

Abstract: The timing of final assembly and initiation of subsequent rifting of Rodinia is disputed. New rutile ages (913?±?9?Ma, 900?±?8?Ma and 873?±?3?Ma) and published zircon, monazite, titanite, biotite, muscovite and xenotime geochronology from the Capricorn Orogen (West Australian Craton) reveal a significant early Neoproterozoic event characterized by very low to low metamorphic grade, abundant metasomatism, minor leucogranitic and pegmatitic magmatism and NW-SE fault reactivation episodes between ca. 955 and 830?Ma. Collectively, these are termed the ca. 955-830?Ma Kuparr Tectonic Event. An age range of ca. 955-830?Ma is concomitant with the final stages of Rodinia assembly and the initial stages of its attempted breakup. Very low- to low-grade metamorphic and structural geological evidence favor a distal north-south compressional regime as the driver for hydrothermal activity during ca. 955-830?Ma. Nearby continental collision or accretion from the west (e.g., South China and/or Tarim) are ruled out. The cessation of metasomatism and magmatism in the West Australian Craton after ca. 830?Ma is concomitant with the emplacement of the Gairdner-Amata dyke swarm and associated magmatic activity in South China and Laurentia, the inception of the Adelaide Rift Complex and the deposition of the Centralian Superbasin. We posit that the cessation of hydrothermal activity in the Capricorn Orogen was caused by a tectonic switch from compressional to extensional at ca. 830?Ma. Magmatic and hydrothermal fluids were transferred away from the Capricorn Orogen to the incipient Adelaide Rift Complex, terminating metasomatism in the West Australian Craton. Ultimately, the Kuparr Tectonic Event marked the final stages of Rodinia assembly and its cessation marks the initial stages of its attempted breakup.
DS0712-0003
2007
Agar, B.Agar, B., Coulter, D.Remote sensing for mineral exploration - a decade perspective 1997-2007. ( not specific to diamonds)... good review.Proceedings of Exploration 07 edited by B. Milkereit, pp. 109-136.TechnologyRemote sensing - review
DS1994-0025
1994
Agar, R.A.Agar, R.A.Geoscan airborne multi-spectral scanners as exploration tools for Western Australian diamond and gold deposits.University of Western Australia, Publishing No. 26, pp. 435-447.AustraliaRemote sensing, Deposit -Aries
DS1994-0026
1994
Agar, R.A.Agar, R.A.Geoscan airborne multi-spectral scanners as applied to exploration for western Australian diamond and gold.Tenth Thematic conference on geologic remote sensing, held May, 1994, Vol. 10, pp. II.651-666.AustraliaRemote sensing, Geoscan
DS1990-0846
1990
Agar, S.M.Knipe, R.J., Ritter, E.H., Agar, S.M., Prior, D.J., Law, R.D.Deformation mechanisms, rheology and tectonicsGeological Society of London Special Publication, No. 54, 520pGlobalRock deformation, fracture, faulting, flow mechanisms, Flow laws, rock fabrics, tectonics
DS1412-0003
2014
Agard, P.Agard, P., Zuo, X., Funiciello, F., Bellahsen, N., Faccenna, C., Savva, D.Obduction: why, how and where. Clues from analog models.Earth and Planetary Science Letters, Vol. 393, pp. 132-145.MantleSubduction
DS1812-2772
2018
Agard, P.Agard, P., Plunder, A., Angiboust, S., Bonnet, G., Ruh, J.The subduction plate interface: rock record and mechanical coupling ( from long to short timescales).Lithos, Vol. 320-321, pp. 537-566.Mantlesubduction

Abstract: Short- and long-term processes at or close to the subduction plate interface (e.g.,mineral transformations, fluid release, seismicity and more generally deformation) might be more closely related than previously thought. Increasing evidence from the fossil rock record suggests that some episodes of their long geological evolution match or are close to timescales of the seismic cycle. This contribution uses rocks recovered (episodically) from subduction zones, together with insights from thermomechanical modelling, to provide a new dynamic vision of the nature, structure and properties of the plate interface and to bridge the gap between the mechanical behavior of active subduction zones (e.g.,coupling inferred from geophysical monitoring) and fossil ones (e.g.,coupling required to detach and recover subducted slab fragments). Based on critical observations and an exhaustive compilation of worldwide subducted oceanic units (for which the presence near the plate interface, rock types, pressure, temperature, T/P gradients, thickness and timing of detachment can be assessed), the present study demonstrates how long-term mechanical coupling exerts a key control on detachment from the slab and potential rock recovery. Critical assessment of rock T/P characteristics indicates that these fragments can indeed be used as natural probes and provide reliable information on subduction interface dynamics down to ~2.8?GPa. Rock clusters are identified at depths of 30, 5560 and 80?km, with some differences between rock types. Data also reveal a first-order evolution with subduction cooling (in the first ~5?Myr), which is interpreted as reflecting a systematic trend from strong to weak mechanical coupling, after which subduction is lubricated and mostly inhibits rock recovery. This contribution places bounds on the plate interface constitution, regular thickness (<300?m; i.e. where/when there is no detachment), changing geometry and effective viscosity. The concept of ‘coupled thickness' is used here to capture subduction interface dynamics, notably during episodes of strong mechanical coupling, and to link long- and short-term deformation. Mechanical coupling depends on mantle wedge rheology, viscosity contrasts and initial structures (e.g.,heterogeneous lithosphere, existence of décollement horizons, extent of hydration, asperities) but also on boundary conditions (convergence rates, kinematics), and therefore differs for warm and cold subduction settings. Although most present-day subduction zone segments (both along strike and downdip) are likely below the detachment threshold, we propose that the most favorable location for detachment corresponds to the spatial transition between coupled and decoupled areas. Effective strain localization involves dissolution-precipitation and dislocation creep but also possibly brittle fractures and earthquakes, even at intermediate depths.
DS1984-0394
1984
Agarwal, A.Karkare, S.G., Agarwal, A.The alkalic ultramafic carbonatitic complex of Kala DoohgarKachchh, District Gujrat and the problem of basement toJurassicsIndian Journal of GeocheM., Vol. 1, No. 2, pp. 11-26IndiaCamptonite, Carbonatite
DS1999-0002
1999
Agarwal, B.N.P.Agarwal, B.N.P., Das, L.K., Shaw, R.K.Gravity anomalies, tectonics and ore deposits: a predictive genetic mode lover Aravallis, India.Global Tectonics and Met., Vol. 7, No. 1, Feb. pp. 47-52.IndiaGeophysics - gravity, Model - not specific to diamonds
DS1999-0003
1999
Agarwal, B.N.P.Agarwal, B.N.P., Das, L.K., Shaw, R.K.Tectonics and metallogeny over Central Indian Shield: a geophysicalanalysis.Global Tectonics and Met., Vol. 7, No. 1, Feb. pp. 41-46.IndiaGeophysics - gravity, Tectonics - not specific to diamonds
DS1999-0004
1999
Agarwal, B.N.P.Agarwal, B.N.P., Shaw, R.K.Three dimensional configuration of Moho discontinuity over some parts Of india from gravity field data.Global Tectonics and Met., Vol. 7, No. 1, Feb. pp. 13-14.IndiaLithosphere, Structure - MOHO discontinuty
DS1980-0050
1980
Agarwal, K.Banerjee, P.K., Agarwal, K.History of Diamond Mining With Special Reference to PannaTranscript of Paper From Diamond Seminar, Bombay, 9P.India, Madhya PradeshHistory
DS2002-0010
2002
Agarwal, K.K.Agarwal, K.K., Singh, I.B., Sharma, M., Sharma, S., Rajagopalan, G.Extensional tectonic activity in the cratonward parts ( peripheral bulge) of the Ganga Plain foreland basin, India.International Journal of Earth Sciences, Vol. 91, 5, pp. 897-905.IndiaTectonics - not specific to diamonds
DS1960-0586
1965
Agarwal, M.K.Patel, A.G., Agarwal, M.K.Microstructure of Panna DiamondsAmerican Mineralogist., Vol. 50, No. 1/2, PP. 124-131.India, PannaDiamond Morphology
DS1970-0894
1974
Agarwal, Y.K.Chaudhuri, R., Banerji, K.C., Agarwal, Y.K.The Interactions of Coal and Mica PeridotiteIndia Sci. Congr. 61st. Session Proceedings, No. 3, PP. 147-148.IndiaBlank
DS1312-0006
2013
Agashev, A.Afanasiev, V., Agashev, A., Pokhilenko, N.Dispersion haloes of kimberlite indicator minerals in the Siberian Platform: history and formation conditions.Geology of Ore Deposits, Vol. 55, 4, pp. 256-264.RussiaMineral chemistry
DS1502-0100
2015
Agashev, A.Shchukina, E., Agashev, A., Pokhilenko, N.Multistage metasomatism in lithospheric mantle beneath V. Grib pipe ( Arkhangelsk Diamondiferous province, Russia): evidence from REE patterns in garnet xenocrysts.Economic Geology Research Institute 2015, Vol. 17,, # 1940, 1p. AbstractRussia, Kola Peninsula, ArchangelDeposit - Grib
DS1708-1590
2017
Agashev, A.Agashev, A.Geochemistry of eclogite xenoliths from kimberlite pipe Udachnaya: section of Archean oceanic crust sampled?11th. International Kimberlite Conference, OralRussia, Siberiadeposit - Udachnaya

Abstract: A suite of 17 unique big (1 to 20 kg) and fresh ecligite xenoliths from Udachnaya kimberlite pipe have been studied for their whole-rock and minerals major and trace elements composition.Whole rock major elements composition of the Udachnaya eclogite xenoliths suite have a great variability in their MgO contents (9-19Wt%). Based on major elements composition Udachnaya eclogites can be subdivided in two subsets, high magnesian (Mg# 68.8-81.9) and low magnesian (Mg# 56.8-59). High variations also shown by Al2O3 and Na2O concentrations and high Mg# samples tend to contain less of those oxides then low Mg# samples with some exceptions. Two eclogitic groups are clearly different in style of inter-elements correlations. FeO and CaO contents are positively correlate with MgO in low Mg# group of eclogites but negatively in high Mg# group. The same relations present between Al2O3 contents of eclogite group with their Mg#. Compared to present day MORB composition eclogite samples have similar contents of most of elements with some depletion in TiO2 and P2O5 and enrichment in MgO and K2O. The variability of these elements concentrations can be related to melt extraction while elevated K2O can indicate late metasomatic enrichment. In terms of trace elements composition Udachnaya eclogites are enriched over PM but comparable to that of MORB composition, except significant enrichment in LILE elements (Rb, Ba, K, Sr). The records of both subduction related processes and mantle metasomatism could be find in geochemical features of these rocks. Most of the eclogites show positive Eu anomaly which is direct evidence of plagioclase accumulation in eglogites protolith. Variation of La/Yb ratio (1-11), in majority of samples are the range 2-4 indicates different degrees of samples metasomatic enrichment in LREE. Udachnaya eclogites have range of Sm/Nd ratio from 0.25 to 0.5 (MORB is 0.32) which positive covariates with Nd content. This trend could not be a result of melt extraction nor metasomatic enrichment rather it could reflect heterogeneity of oceanic crust composition and/or mixing with peridotite component during subduction.
DS1708-1591
2017
Agashev, A.Agashev, A.Geochemistry of Mirny field kimberlites, Siberia.11th. International Kimberlite Conference, PosterRussia, Siberiadeposit - Mirny
DS0412-1561
2003
Agashev, A.M.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
DS0412-1562
2003
Agashev, A.M.Pokhilenko, N.P., Agashev, A.M., McDonald, J.A., Vavilov, M.A., Clark, D.B., Wright, K.J.Kimberlites and carbonatites of the Snap Lake King Lake dyke system: structural setting, petrochemistry and petrology of a uniqu8 IKC Program, Session 7, POSTER abstractCanada, Northwest TerritoriesKimberlite petrogenesis Deposit - Snap Lake, King Lake
DS0512-0007
2004
Agashev, A.M.Agashev, 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
DS0612-0004
2006
Agashev, A.M.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
DS0812-0003
2008
Agashev, A.M.Agashev, A.M., Kuligan, S.S., Orihashi, Y., Pokhilenko, N.P., Vavilov, M.A., Clarke, D.Ages of zircons from Jurassic sediments of Bluefish River slope, NWT and the possible age of kimberlite activity in the Lena West property.Doklady Earth Sciences, Vol. 421, 1, pp. 751-754.Canada, Northwest TerritoriesDeposit - Lena West, geochronology
DS0812-0004
2008
Agashev, A.M.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
DS0912-0003
2009
Agashev, A.M.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
DS1012-0005
2010
Agashev, A.M.Agashev, A.M., Pokhilenko, N.P., Cherepanova, Yu.V., Golovin, A.V.Geochemical evolution of rocks at the base of the lithospheric mantle: evidence from study of xenoliths of deformed peridotites from kimberlite of UdachnayaDoklady Earth Sciences, Vol. 432, 2, pp. 746-749.RussiaDeposit - Udachnaya
DS1112-1063
2011
Agashev, A.M.Tychkov, N.S., Agashev, A.M., Pokhilenko, N.P., Bzhan, I.S.Estimation of the refertilization grade of lithosphere roots by the chemical composition of garnets from Siberian kimberlites.Doklady Earth Sciences, Vol. 439, 2, pp.1175-1178.Russia, SiberiaGeochemistry - garnets
DS1212-0005
2012
Agashev, A.M.Agashev, A.M., Ionov, D.A., Pokhilenko, N.P., Golovin, A.V., Surgutonova, E.A., Sharygin, I.S.Metasomatism in cratonic mantle root: insight from geochemistry of deformed peridotite xenoliths of Udachnaya pipe.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, YakutiaDeposit - Udachnaya
DS1212-0006
2012
Agashev, A.M.Agashev, A.M., Orihashi, Y., Rotman, A.Ua., Pokhilenko, N.P., erov, I.V., Tolstov, A.V.Rutile and titanite as the minerals for dating kimberlite emplacement age: an example of Amakinskaya and Taezhnaya pipes of Mirny field, Siberia10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, YakutiaDeposit - Mirny field
DS1212-0562
2012
Agashev, A.M.Pokhilenko, N.P., Afanasev, V.P., McDonald, J.A., Vavilov, M.A., Kulgin, S.S., Pokhilenko, L.N., Golovin, A.V., Agashev, A.M.Kimberlite indicator minerals in terrigene sediments of lower part of Mackenzie River Basin, NWT, Canada: evidence of new craton with thick lithosphere.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractCanada, Northwest TerritoriesGeochemistry - KIMS
DS1212-0739
2012
Agashev, A.M.Tychkov, N.S., Agashev, A.M., Pokhilenko, N.P.Refertilisation grade estimations of lithosphere roots by the chemical composition of garnets from Siberian kimberlites.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, SiberiaGarnet
DS1312-0010
2013
Agashev, A.M.Agashev, A.M., Ionov, D.A., Pkhilenko, N.P., Golovin, A.V., Cherepanova, Yu., Sharygin, I.S.Metasomatism in lithospheric mantle roots: constraints from whole rock and mineral chemical composition of deformed peridotite xenoliths from kimberlite pipe Udachnaya.Lithos, Vol. 160-161, pp. 201-215.Mantle, Russia, SiberiaDeposit - Udachnaya
DS1312-0045
2013
Agashev, A.M.Ashchepkov, I.V., Ntaflos, T., Kuligin, S.S., Malygina, E.V., Agashev, A.M., Logvinova, A.M., Mitukhin, S.I., Vladykin, N.V.Deep seated xenoliths from the brown breccia of the Udachnaya pipe, Siberia.Proceedings of the 10th International Kimberlite Conference, Vol. 1, Special issue of the Journal of Geological Society of India, Vol. 1, pp. 59-73.RussiaDeposit - Udachnaya
DS1412-0022
2014
Agashev, A.M.Ashchepkov, I.V., Vladykin, N.N., Ntaflos, T., Kostrovitsky, S.I., Prokopiev, S.A., Downes, H., Smelov, A.P., Agashev, A.M., Logvinova, A.M., Kuligin, S.S., Tychkov, N.S., Salikhov, R.F., Stegnitsky, Yu.B., Alymova, N.V., Vavilov, M.A., Minin, V.A., BabusLayering of the lithospheric mantle beneath the Siberian Craton: modeling using thermobarometry of mantle xenolith and xenocrysts. Tectonophysics, Vol. 634, 5, pp. 55-75.Russia, YakutiaDaldyn, Alakit, Malo-Botuobinsky fields
DS1412-0373
2014
Agashev, A.M.Howarth, G.H., Barry, P.H., Pernet-Fisher, J.F., Baziotis, I.P., Pokhilenko, N.P., Poikhilenko, L.N., Bodnar, R.L., Taylor, L.A., Agashev, A.M.Superplume metasomatism: evidence from Siberian mantle xenoliths.Lithos, Vol. 184-187, pp. 209-224.RussiaMetasomatism
DS1412-0695
2014
Agashev, A.M.Poikhilenko, N.P., Afanasiev, V.P., Agashev, A.M., Malkovets, V.G., Poikhilenko, L.N.New archean terranes with thick lithosphere of arctic regions of Siberia and North American ancient platforms: are they prospective for Diamondiferous kimberlites?30th. International Conference on Ore Potential of alkaline, kimberlite and carbonatite magmatism. Sept. 29-, Russia, CanadaKimberlite
DS1412-0718
2014
Agashev, A.M.Ragozin, A.L., Zedgenizov, D.A., Shatskii, V.S., Orihashi, Y., Agashev, A.M., Kagi, H.U Pb age of rutile from the eclogite xenolith of the Udachnaya kimberlite pipe.Doklady Earth Sciences, Vol. 457, 1, pp. 861-864.Russia, YakutiaDeposit - Udachnaya
DS1412-0937
2014
Agashev, A.M.Tychkov, N.S., Agashev, A.M., Malygina, E.V., Nikolenko, E.I., Pokhilenko, N.P.Thermal pertubations in the lithospheric mantle as evidenced from P-T equilibrium conditions of xenoliths from the Udachnaya kimberlite pipe.Doklady Earth Sciences, Vol. 454, 1, pp. 84-88.Russia, YakutiaDeposit - Udachnaya
DS1412-1013
2014
Agashev, A.M.Yudin, D.S., Tomilenko, A.A., Travin, A.V., Agashev, A.M., Pokhilenko, N.P., Orihashi, yu.The age of the Udachnaya-East kimberlite: U/Pb and 40 Ar/39Ar data.Doklady Earth Sciences, Vol. 455, 1, pp. 288-290.RussiaDeposit - Udachnaya
DS1502-0091
2015
Agashev, A.M.Poikilenko, N.P., Agashev, A.M., Litasov, K.D., Pokhilenko, L.N.Carbonatite metasomatism of peridotite lithospheric mantle: implications for diamond formation and carbonatite-kimberlite magmatism.Russian Geology and Geophysics, Vol. 56, 1, pp. 280-295.MantleCarbonatite
DS1504-0183
2015
Agashev, A.M.Barry, P.H., Hilton, D.R., Day, J.M.D., Pernet-Fisher, J.F., Howarth, G.H., Magna, T., Agashev, A.M., Pokhilenko, N.P., Opkhilenko, L.N., Taylor, L.A.Helium isotope evidence for modification of the cratonic lithosphere during the Permo-Triassic Siberian flood basalt event.Lithos, Vol. 216-217, pp. 73-80.Russia, SiberiaDeposit - Udachnaya, Obnazhennaya

Abstract: Major flood basalt emplacement events can dramatically alter the composition of the sub-continental lithospheric mantle (SCLM). The Siberian craton experienced one of the largest flood basalt events preserved in the geologic record — eruption of the Permo-Triassic Siberian flood basalts (SFB) at ~250 Myr in response to upwelling of a deep-rooted mantle plume beneath the Siberian SCLM. Here, we present helium isotope (3 He/ 4 He) and concentra-tion data for petrologically-distinct suites of peridotitic xenoliths recovered from two temporally-separated kim-berlites: the 360 Ma Udachnaya and 160 Ma Obnazhennaya pipes, which erupted through the Siberian SCLM and bracket the eruption of the SFB. Measured 3 He/ 4 He ratios span a range from 0.1 to 9.8 R A (where R A = air 3 He/ 4 He) and fall into two distinct groups: 1) predominantly radiogenic pre-plume Udachnaya samples (mean clinopyroxene 3 He/ 4 He = 0.41 ± 0.30 R A (1s); n = 7 excluding 1 outlier), and 2) 'mantle-like' post plume Obnazhennaya samples (mean clinopyroxene 3 He/ 4 He = 4.20 ± 0.90 R A (1s); n = 5 excluding 1 outlier). Olivine separates from both kimberlite pipes tend to have higher 3 He/ 4 He than clinopyroxenes (or garnet). Helium con-tents in Udachnaya samples ([He] = 0.13–1.35 µcm 3 STP/g; n = 6) overlap with those of Obnazhennaya ([He] = 0.05–1.58 µcm 3 STP/g; n = 10), but extend to significantly higher values in some instances ([He] = 49– 349 µcm 3 STP/g; n = 4). Uranium and thorium contents are also reported for the crushed material from which He was extracted in order to evaluate the potential for He migration from the mineral matrix to fluid inclusions. The wide range in He content, together with consistently radiogenic He-isotope values in Udachnaya peridotites suggests that crustal-derived fluids have incongruently metasomatized segments of the Siberian SCLM, whereas high 3 He/ 4 He values in Obnazhennaya peridotites show that this section of the SCLM has been overprinted by Permo-Triassic (plume-derived) basaltic fluids. Indeed, the stark contrast between pre-and post-plume 3 He/ 4 He ra-tios in peridotite xenoliths highlights the potentially powerful utility of He-isotopes for differentiating between various types of metasomatism (i.e., crustal versus basaltic fluids).
DS1507-0336
2015
Agashev, A.M.Shchukina, E.V., Agashev, A.M., Golovin, N.N., Pokhilenko, N.P.Equigranualr eclogites from the V. Grib kimberlite pipe: evidence for Paleoproterozoic subduction on the territory of the Arkangelsk Diamondiferous province.Doklady Earth Sciences, Vol. 462, 1, pp. 497-501.Russia, Archangel, Kola PeninsulaDeposit - Grib
DS1602-0237
2015
Agashev, A.M.Shchukina, E.V., Agashev, A.M., Kostrovitsky, S.I., Pokhilenko, N.P.Metasomatic processes in the lithospheric mantle beneath the V. Grib kimberlite pipe ( Arkangelsk Diamondiferous province, Russia).Russian Geology and Geophysics, Vol. 56, pp. 1701-1716.RussiaDeposit - Grib

Abstract: New data on metasomatic processes in the lithospheric mantle in the central part of the Arkhangelsk diamondiferous province (ADP) are presented. We studied the major- and trace-element compositions of minerals of 26 garnet peridotite xenoliths from the V. Grib kimberlite pipe; 17 xenoliths contained phlogopite. Detailed mineralogical, petrographic, and geochemical studies of peridotite minerals (garnet, clinopyroxene, and phlogopite) have revealed two types of modal metasomatic enrichment of the lithospheric-mantle rocks: high temperature (melt) and low-temperature (phlogopite). Both types of modal metasomatism significantly changed the chemical composition of the peridotites. Low-temperature modal metasomatism manifests itself as coarse tabular and shapeless phlogopite grains. Two textural varieties of phlogopite show significant differences in chemical composition, primarily in the contents of TiO2, Cr2O3, FeO, Ba, Rb, and Cs. The rock-forming minerals of phlogopite-bearing peridotites differ in chemical composition from phlogopite-free peridotites, mainly in higher FeO content. Most garnets and clinopyroxenes in peridotites are the products of high-temperature mantle metasomatism, as indicated by the high contents of incompatible elements and REE pattern in these minerals. Fractional-crystallization modeling gives an insight into the nature of melts (metasomatic agents). They are close in composition to picrites of the Izhmozero field, basalts of the Tur’ino field, and carbonatites of the Mela field of the ADP. The REE patterns of the peridotite minerals make it possible to determine the sequence of metasomatic enrichment of the lithospheric mantle beneath the V. Grib kimberlite pipe.
DS1606-1095
2016
Agashev, A.M.Ilyina, O.V., Tychkov, N.S., Agashev, A.M., Golovin, A.V., Izokh, A.E., Kozmenko, O.A., Poikilanko, N.P.PGE distribution in deformed lherzolites of the Udachnaya kimberlite pipe ( Yakutia).Doklady Earth Sciences, Vol. 467, 2, pp. 408-411.Russia, YakutiaDeposit - Udachnaya

Abstract: The results of the first study of the PGE distribution in deformed lherzolites of the Udachnaya kimberlite pipe (Yakutia) are presented here. The complex character of evolution of the PGE composition in the Deformed lherzolites is assumed to be the result of silicate metasomatism. At the first stage, growth in the amount of clinopyroxene and garnet in the rock is accompanied by a decrease in the concentration of the compatible PGE (Os, Ir). During the final stage, the rock is enriched with incompatible PGE (Pt, Pd) and Re possible due to precipitation of submicron-sized particles of sulfides in the interstitial space of these mantle rocks.
DS1612-2336
2016
Agashev, A.M.Shchukina, E.V., Agashev, A.M., Pokhilenko, N.P.Metasomatic origin of garnet xenocrysts from the V. Grib kimberlite pipe, Arkhangelsk region, NW Russia.Geoscience Frontiers, in press availableRussia, Archangel, Kola PeninsulaDeposit - Grib

Abstract: This paper presents new major and trace element data from 150 garnet xenocrysts from the V. Grib kimberlite pipe located in the central part of the Arkhangelsk diamondiferous province (ADP). Based on the concentrations of Cr2O3, CaO, TiO2 and rare earth elements (REE) the garnets were divided into seven groups: (1) lherzolitic “depleted” garnets (“Lz 1”), (2) lherzolitic garnets with normal REE patterns (“Lz 2”), (3) lherzolitic garnets with weakly sinusoidal REE patterns (“Lz 3”), (4) lherzolitic garnets with strongly sinusoidal REE patterns (“Lz 4”), (5) harzburgitic garnets with sinusoidal REE patterns (“Hz”), (6) wehrlitic garnets with weakly sinusoidal REE patterns (“W”), (7) garnets of megacryst paragenesis with normal REE patterns (“Meg”). Detailed mineralogical and geochemical garnet studies and modeling results suggest several stages of mantle metasomatism influenced by carbonatite and silicate melts. Carbonatitic metasomatism at the first stage resulted in refertilization of the lithospheric mantle, which is evidenced by a nearly vertical CaO-Cr2O3 trend from harzburgitic (“Hz”) to lherzolitic (“Lz 4”) garnet composition. Harzburgitic garnets (“Hz”) have probably been formed by interactions between carbonatite melts and exsolved garnets in high-degree melt extraction residues. At the second stage of metasomatism, garnets with weakly sinusoidal REE patterns (“Lz 3”, “W”) were affected by a silicate melt possessing a REE composition similar to that of ADP alkaline mica-poor picrites. At the last stage, the garnets interacted with basaltic melts, which resulted in the decrease CaO-Cr2O3 trend of “Lz 2” garnet composition. Cr-poor garnets of megacryst paragenesis (“Meg”) could crystallize directly from the silicate melt which has a REE composition close to that of ADP alkaline mica-poor picrites. P-T estimates of the garnet xenocrysts indicate that the interval of ~60-110 km of the lithospheric mantle beneath the V. Grib pipe was predominantly affected by the silicate melts, whereas the lithospheric mantle deeper than 150 km was influenced by the carbonatite melts.
DS1701-0034
2016
Agashev, A.M.Surgutanova, E.A., Agashev, A.M., Demonterova, E.I., Golovin, A.V., Pokhilenko, N.P.Sr and Nd isotope composition of deformed peridotite xenoliths from Udachnaya kimberlite pipe.Doklady Earth Sciences, Vol. 471, 1, pp. 1104-1207.RussiaDeposit - Udachnaya

Abstract: New results of Rb-Sr and Sm-Nd isotope analyses have been obtained on samples of deformed peridotite xenoliths collected from the Udachnaya kimberlite pipe (Yakutia). The data obtained imply two main stages of metasomatic alteration of the lithospheric mantle base matter in the central part of the Siberian Craton. Elevated ratios of Sr isotopes may be considered as evidence of an ancient stage of metasomatic enrichment by a carbonatite melt. The acquired Nd isotope composition together with the geochemistry of the deformed peridotite xenoliths suggests that the second stage of metasomatic alteration took place shortly before formation of the kimberlite melt. The metasomatic agent of this stage had a silicate character and arrived from an asthenosphere source, common for the normal OIB type (PREMA) and the Group-I kimberlite.
DS1709-2000
2017
Agashev, A.M.Ilyina, O.V., Pokhilenko, L.N., Agashev, A.M.Characteristics of platinum group elements ( PGE) distribution in mantle xenoliths from kimberlite Udachnaya pipe ( Yakutia).Goldschmidt Conference, abstract 1p.Russia, Yakutiadeposit - Udachnaya

Abstract: We report PGE data in xenoliths of the deformed and granular peridotites. The deformed peridotites are the most deep-seated rocks and represent a narrow range of depth (180-220 km) while granular peridotites are located throughout the section of the lithospheric mantle. PGE distribution in the deformed peridotites [1] generally corresponds to that in our granular peridotites and xenoliths from Lesotho [2]. But in contrast with broad range of PGE concentrations in granular peridotites, the deformed peridotites show nearly flat pattern from Os to Pt, except of Pd (Fig.1). Granular peridotites show good positive correlation between PGE and Fe2O3. We suppose that they enriched in PGE by iron phase during its evolution. As for deformed peridotites we propose that they were depleted in Ir and Os followed by the increase of Ga and Cpx on the first stage of mantle metasomatism. On the last stage the enrichment of Pt, Pd and Re was probably a result of submicron sulphide phase’s presipitation in the interstices of mantle rocks.
DS1807-1477
2018
Agashev, A.M.Agashev, A.M., Pokhilenko, L.N., Pokhilenko, N.P., Shchukina, E.V.Geochemistry of eclogite xenoliths from the Udachnaya kimberlite pipe: section of ancient oceanic crust sampled.Lithos, DOI:10.1016 /j.lithos.2018 .05.027 available 52p.Russiadeposit - Udachnaya

Abstract: A suite of seventeen unique, large, and fresh eclogite xenoliths from the Udachnaya pipe have been studied for their whole-rock and mineral major- and trace-element compositions. Based on their major-element compositions, the Udachnaya eclogites can be subdivided in two groups: high magnesian (Mg# 68.8-81.9) and low magnesian (Mg# 56.8-59). The two eclogite groups are clearly different in the style of correlation between major elements. Positive correlations of FeO and CaO with MgO are observed in the low-magnesian group, whereas these correlations are negative in the high-magnesian group. In terms of trace element composition, the Udachnaya eclogites are enriched over Primitive Mantle, but comparable to mid-ocean-ridge basalt composition, except for significant enrichment in large-ion lithophile elements (LILE; Rb, Ba, K, Sr). Most of the samples show a positive Eu anomaly, irrespective of group. Reconstructed whole-rock composition from clinopyroxene and garnet modal abundances contains much less incompatible elements (LILE, light rare earth elements, high field strength elements) than measured composition. Approximately 60 to 100% of the middle rare earth elements, Zr, and Hf, and nearly 100% of the heavy rare earth elements, Co, V, and Sc of the whole-rock budget are concentrated in Gar and Cpx. Variations in major element compositions cover a full section of the modern and Archaean oceanic crust, from troctolite, through gabbroic rocks, to basalts. The low-Mg# eclogites could have formed from upper oceanic crust protoliths, being a mixture of basalts and gabbro, whereas the high-Mg# eclogites are originated from gabbro-troctolite section of the lower oceanic crust. Concordant variations of Eu anomaly with the Lu/Sr ratio and the V and Ni contents in the eclogite compositions are in agreement with the fractionation of plagioclase, clinopyroxene, and olivine in their low-pressure precursor rocks. Negative correlations of SiO2 and MgO, and a low Nd/YbNMORB ratio, in the low-Mg# eclogites are in agreement with partial melt loss, but the presence of accessory quartz limits the degree of melting to 13%. Major and trace element compositions suggest that the high-Mg# eclogites, and, consequently, the lower oceanic crust, could not have experienced significant melt loss, and subduction in the Archaean may have been essentially dry, compared to the present day.
DS1808-1722
2018
Agashev, A.M.Agashev, A.M., Nakai, S., Serov, I.V., Tolstov, A.V., Garanin, K.V., Kovalchuk, O.E.Geochemistry and origin of the Mirny field kimberlites, Siberia.Mineralogy and Petrology, doi.org/10.1007/s00710-018-06174 12p.Russia, Siberiadeposit - Mirny

Abstract: Here we present new data from a systematic Sr, Nd, O, C isotope and geochemical study of kimberlites of Devonian age Mirny field that are located in the southernmost part of the Siberian diamondiferous province. Major and trace element compositions of the Mirny field kimberlites show a significant compositional variability both between pipes and within one diatreme. They are enriched in incompatible trace elements with La/Yb ratios in the range of (65-00). Initial Nd isotope ratios calculated back to the time of the Mirny field kimberlite emplacement (t?=?360 ma) are depleted relative to the chondritic uniform reservoir (CHUR) model being 4 up to 6 ?Nd(t) units, suggesting an asthenospheric source for incompatible elements in kimberlites. Initial Sr isotope ratios are significantly variable, being in the range 0.70387-0.70845, indicating a complex source history and a strong influence of post-magmatic alteration. Four samples have almost identical initial Nd and Sr isotope compositions that are similar to the prevalent mantle (PREMA) reservoir. We propose that the source of the proto-kimberlite melt of the Mirny field kimberlites is the same as that for the majority of ocean island basalts (OIB). The source of the Mirny field kimberlites must possess three main features: It should be enriched with incompatible elements, be depleted in the major elements (Si, Al, Fe and Ti) and heavy rare earth elements (REE) and it should retain the asthenospheric Nd isotope composition. A two-stage model of kimberlite melt formation can fulfil those requirements. The intrusion of small bodies of this proto-kimberlite melt into lithospheric mantle forms a veined heterogeneously enriched source through fractional crystallization and metasomatism of adjacent peridotites. Re-melting of this source shortly after it was metasomatically enriched produced the kimberlite melt. The chemistry, mineralogy and diamond grade of each particular kimberlite are strongly dependent on the character of the heterogeneous source part from which they melted and ascended.
DS1808-1775
2017
Agashev, A.M.Paquette, J.L., Ionov, D.A., Agashev, A.M., Gannoun, A., Nikolenko, E.I.Age, provenance and Precambrian evolution of the Anabar shield from U Pb and Lu Hf isotope dat a on detrital zircons, and the history of the northern and central Siberian craton.Precambrian Research, Vol. 301, pp. 134-144.Russiacraton

Abstract: The Anabar shield in northern Siberia is one of the world’s least studied Precambrian areas, and provides a ‘window’ into the crustal basement of the central and northern Siberian craton. We report U-Pb and Hf isotope data for detrital zircons sampled in a profile across its major structural units. They define a U-Pb age range from 1.8 to 3.4 Ga with three main periods: 1.8-2.0 Ga, 2.4-2.8 Ga and 3.0-3.4 Ga. The oldest zircons yield super-chondritic eHf(t) implying that the parental magmas of their source rocks were juvenile, i.e. formed from depleted mantle (DM). Thus, the crustal basement of the Anabar shield, and probably the whole central and northern Siberian craton, started to form in the mid-Paleoarchean, and included no recycled crust. Zircons with 2.5-2.7 Ga ages define two eHf(t) intervals. One is super-chondritic (+2 to +7) implying juvenile sources, the other is sub-chondritic (-3 to -12) indicative of recycled crust, probably formed at 3.2-3.4 Ga, in magma sources. Nearly all 1.8-2.0 Ga zircons have sub-chondritic eHf(t) (-2 to -29) implying derivation from sources dominated by recycled crust formed at ~2.6 Ga and ~3.4 Ga and little or no juvenile addition. These events accompanied amalgamation of the entire craton by welding of Archean domains. The Bekelekh unit of the Daldyn series has the highest proportion of ~2.6 Ga zircons and may be the oldest ‘nucleus’ of the Anabar shield, whereas the Kilegur unit of the same series is essentially Proterozoic (1.95 Ga). The largest amount of 3.1-3.4 Ga zircons, as well as common 2.6-2.7 Ga zircons, occur in the Ambardakh unit of the Upper Anabar series. Our data suggest alternation of areas with dominant ages of 1.95 Ga and ~2.6 Ga, with the younger zircons coming from granites and granulites, and the older ones from gneisses. They show no evidence for significant ages differences for the Anabar and Olenek provinces. The final amalgamation of the entire Siberian craton by welding of Archean blocks, may have taken place at around 1954 ± 6 Ma.
DS1903-0501
2019
Agashev, A.M.Chepurov, A., Faryad, S.W., Agashev, A.M.Experimental crystallization of a subcalcic Cr-rich pyrope in the presence of REE bearing carbonatite.Chemical Geology, carbonatite

Abstract: This paper focuses on formation of subcalcic Cr-rich garnet (up to 14.25?wt% Cr2O3) in the model ultramafic system corresponding to natural harzburgite with the presence of REE-bearing fluid phase. The experiments were carried out using a “split-sphere” type multi-anvil high-pressure apparatus (BARS) at a pressure of 5?GPa and a temperature of 1300?°C. Natural serpentine, chromite, corundum and REE-carbonatite were used as starting components. Crystallization of garnet occurred in subsolidus conditions by the reaction of orthopyroxene and spinel in the presence of fluid phase. Composition of fluid was controlled by interaction of water released by decomposition of serpentine with carbonate. By using different amounts of carbonatite (0.5 and 1.5?wt%) as a source of calcium and REE, subcalcic Cr-rich garnets with up to 3.5?wt% CaO were crystallized, which are typical for inclusions of harzburgitic paragenesis in natural diamonds. The experiments demonstrated that the rare earth elements (REE) released from the initial carbonatite were transported by the fluid and were incorporated into the newly formed garnet. The distribution of REE in garnet revealed a vivid enrichment toward the heavy REE (HREE), showing the pattern with a very steep slope. These results confirmed high partitioning of HREE into garnet. The present study indicates that the mantle carbonatites, which contain very high proportions of light REE (LREE) to HREE, can play an important role as source material in formation of REE-rich fluids to crystallize garnets with typical REE patterns in mantle peridotites.
DS1998-0010
1998
Agashev, A.M.Agashev, A.M., Fomin, A.S., Watanabe, T., Pokhilenko, N.Preliminary age determination of recently discovered kimberlites of the Siberian kimberlite province.7th International Kimberlite Conference Abstract, pp. 9-10.Russia, SiberiaGeochronology, Deposit - Sredne-Marxz, Botuobinskaya, Nurbinskaya
DS1998-0011
1998
Agashev, A.M.Agashev, A.M., Watanabe, T., Kuligin, S.S., PokhilenkoStrontium neodymium isotopes in the garnet pyroxenite xenoliths from Siberian kimberlites: a new insight into lithospheric..7th International Kimberlite Conference Abstract, pp. 11-13.Russia, SiberiaGarnet pyroxenite, mantle, Geochemistry
DS2000-0008
2000
Agashev, A.M.Agashev, A.M., Orihashi, Watanabe, Pkhilenko, SerenkoIsotope geochemical features of the Siberian Platform kimberlites in connection with problem of their origin.Russ. Geol. and Geophys., Vol. 41, No. 1, pp. 87-97.Russia, SiberiaGeochemistry, geochronology, Genesis
DS2001-0006
2001
Agashev, A.M.Agashev, A.M., Pokhilenko, McDonald, Takazawa, VavilovA unique kimberlite carbonatite primary association in the Snap lake dyke system: evidence from geochemical..Slave-Kaapvaal Workshop, Sept. Ottawa, 2p. abstractNorthwest TerritoriesGeochemistry, geochronology, Slave Craton, Deposit - Snap Lake
DS2001-0007
2001
Agashev, A.M.Agashev, A.M., Watanabe, Bydaev, Pokhilenko, FominGeochemistry of kimberlites from the Nakyn field, Siberia: evidence for unique source composition.Geology, Vol. 29, No. 3, Mar. pp. 267-70.Russia, SiberiaGeochronology, geochemistry
DS2001-0008
2001
Agashev, A.M.Agashev, A.M., Watanabe, T., Kuligin, S.S., PokhilenkoRubidium-Strontium and Samarium-neodymium isotopes in garnet pyroxenite xenoliths from Siberian kimberlites: an insight into lith. mantleJournal of Mineralogy and Petrology. Sciences, Vol. 96, No. 1, pp. 7-18.Russia, SiberiaGeochronology, Lithospheric - xenoliths
DS2003-1090
2003
Agashev, A.M.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
DS2003-1091
2003
Agashev, A.M.Pokhilenko, N.P., Agashev, A.M., McDonald, J.A., Vavilov, M.A., Clark, D.B..Kimberlites and carbonatites of the Snap Lake King Lake dyke system: structural8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, POSTER abstractNorthwest TerritoriesDeposit - Snap Lake, King Lake
DS1112-1062
2011
Agashev, N.Tychkov, N., Agashev, N., Poikilenko, N., Bazhan, I.Estimation of the refertilization grade of lithosphere roots by the chemical composition of garnets from Siberian kimberlites.Doklady Earth Sciences, Vol. 439, 2, pp. 1175-1178.Russia, SiberiaGarnet geochemistry
DS1996-1301
1996
Agata, T.Shibata, K., Suwa, K., Agata, T.Excess Argon in biotites from Broderick Falls (Webuye) area, western Kenya: implications for tectonothermal..Journal of African Earth Sciences, Vol. 23, No. 3, Oct. 1, pp. 433-442KenyaArchean, Mozambique belt
DS2001-0009
2001
Agbossoumonde, Y.Agbossoumonde, Y., Menot, R.P., Guillot, S.Metamorphic evolution of Neoproterozoic eclogites from south To go (West Africa)Journal of African Earth Sciences, Vol.33,2,Aug.pp.227-44.Togo, West AfricaEclogites, Metamorphism
DS1989-1572
1989
Agee, C.Walker, D., Agee, C.Partioning "equilibrium",temperature gradients, and constraints on earthdifferentiationEarth and Planetary Science Letters, Vol. 96, pp. 49-60GlobalMantle petrogenesis -experimental petrology, Perovskites
DS0612-0358
2006
Agee, C.B.Dwarzski, R.E., Draper, D.A., Shearer, C.K., Agee, C.B.Experimental insights on crystal chemistry of high Ti garnets from garnet melt partitioning of rare earth and high field strength elements.American Mineralogist, Vol. 91, 9, pp. 1536-1546.TechnologyPetrology - crystal chemistry
DS0812-0005
2008
Agee, C.B.Agee, C.B.Compressibility of water in magma and the prediction of density crossovers in mantle differentiation.Philosophical Transactions Royal Society of London Series A Mathematical Physical and Engineering Sciences, Vol. 366, no. 1883, pp. 4239-4252.MantleMagmatism
DS1212-0726
2012
Agee, C.B.Thoma, C.W., Liu, Q., Agee, C.B., Asimov, P.D., Lange, R.A.Multi-technique equation for Fe2SiO4 melt and the density of Fe bearing silicate melts from 0 to 161 Gpa.Journal of Geophysical Research, Vol. 117, 18p. B10206TechnologyMantle mineralogy
DS1989-0009
1989
Agee, C.B.Agee, C.B., Walker, D.Comments on constraints on element partition coefficients between MgSiO3perovskite and liquid determined by direct measurementsEarth and Planetary Science Letters, Vol. 94, pp. 160-163GlobalMantle, Petrogenesis
DS1990-0104
1990
Agee, C.B.Agee, C.B.A new look at differentiation of the earth from melting experiments on the Allende meteoriteNature, Vol. 346, No. 6287 August 30, pp. 834-837GlobalMeteorite
DS1993-0011
1993
Agee, C.B.Agee, C.B.Petrology of the mantle transition zoneAnnual Review of Earth and Planetary Sciences, Vol. 21, pp. 19-42MantlePetrology
DS1993-0012
1993
Agee, C.B.Agee, C.B., Walker, D.Olivine flotation in mantle meltEarth and Planetary Science Letters, Vol. 114, No. 2/3, January pp. 315-324MantleGeochemistry, Olivine
DS1996-0840
1996
Agee, C.B.Li, J., Agee, C.B.Geochemistry of mantle core differentiation at high pressuresNature, Vol. 381, No. 6584, June 20, pp. 686-688.MantleGeochemistry
DS1998-0012
1998
Agee, C.B.Agee, C.B.Phase deformations and seismic structure in the Upper Mantle and transitionzone.Reviews in Mineralogy, Vol. 37, pp. 165-204.MantleGeophysics - seismics, Geodynamics - boundary
DS2001-0682
2001
Agee, C.B.Li, J., Agee, C.B.Element partitioning constraints on the light element composition of the Earth's core.Geophysical Research Letters, Vol. 28, No. 1, Jan. pp.81-4.MantleGeochemistry - core
DS1980-0002
1980
Agee, J.Agee, J., Garrison, J.R.JR., Taylor, L.A.Kimberlites: a Window Into the Mantle Beneath the Southeastern Appalachians #1Geological Society of America (GSA), Vol. 12, No. 4, P. 169. (abstract.).Appalachia, VirginiaGeology
DS1980-0003
1980
Agee, J.J.Agee, J.J., Garrison, J.R.JR., Taylor, L.A.Kimberlites: a Window Into the Mantle Beneath the Southeastern Appalachians #2Eos, Vol. 61, No. 17, P. 412, (abstract.).Appalachia, KentuckyGeology
DS1982-0001
1982
Agee, J.J.Agee, J.J., Garrison, J.R.JR., Taylor, L.A.Petrogenesis of Oxide Minerals in Kimberlite, Elliott County, Kentucky.American Mineralogist., Vol. 67, No. 1-2, PP. 28-42.GlobalIlmenite, Petrography, Microprobe
DS1988-0480
1988
Ageeva, L.I.Mogarovskii, V.V., Davydova, Z.M., Ageeva, L.I.Tungsten in alkaline basaltic rocks of southern Tien-Shan andPamirs.(Russian)Doklady Academy of Sciences Nauk Tadzh. SSSR, (Russian), Vol. 31, No. 8, pp. 542-544RussiaAlkaline rocks
DS1987-0272
1987
Agena, W.F.Hamilton, R.M., Agena, W.F., McKeown, F.A.Deep structure of the new Madrid Seismic zone interpreted from seismic reflection profilesEos, Vol. 68, No.44, November 3, p. 1355. abstract onlyArkansas, MissouriGeophysics
DS1989-0010
1989
Agena, W.F.Agena, W.F., Lee, M.W., Grow, J.A.Reprocessing of the COCORP dat a recorded across the Wichita Mountain Uplift and the Anadarko Basin in southern OklahomaUnited States Geological Survey (USGS) Open File, No. 89-0357, 20p. $ 3.50GlobalGeophysics, Tectonics -COCORP
DS1990-1043
1990
Agena, W.F.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
DS1990-1175
1990
Agena, W.F.Perry, W.J., Agena, W.F.Structural interpretations of the Ouachita frontal zone near HartshorneOklahoma, based on reprocessed seismic reflection dataGeological Society of America (GSA) Annual Meeting, Abstracts, Vol. 22, No. 7, p. A231GlobalTectonics, Geophysics -seismics
DS1994-1764
1994
Agenbacht, A.L.D.Thomas, R.J., Agenbacht, A.L.D., Cornell, D.H., Moore, J.M.The Kibaran of southern Africa: tectonic evolution and metallogenyOre Geology Reviews, Vol. 9, pp. 131-160South Africa, Ontario, NamaqualandSEDEX, metallogeny, Copper, nickel, VMS
DS1993-0013
1993
Ager, D.Ager, D.The new catastrophism... rare event in geological historyCambridge Press, 278p. $ 35.00GlobalBook -ad, CatastrophisM.
DS1994-0027
1994
Ager, D.Ager, D.The new catastrophism... rare event .Cambridge University of press, 231p. $ 25.00GlobalCatastrophisM., Book -ad
DS1993-1151
1993
Aggarwal, H.Oberbeck, V.R., Marshall, J.R., Aggarwal, H.Impacts, tillites and the breakup of GondwanalandJournal of Geology, Vol. 101, No. 1, January, pp. 1-19Craters, Rifting
DS1993-1152
1993
Aggarwal, H.Oberbeck, V.R., Marshall, J.R., Aggarwal, H.Impacts, tillites and the breakup of GondwanalandJournal of Geology, Vol. 101, No. 1, January pp. 1-19.Tectonics, Rifting
DS0512-0915
2004
Aggrawal, S.K.Roy, A., Sarkar, A., Jeyakumar, S., Aggrawal, S.K., Ebihara, M., Satoh, H.Late Archean mantle metasomatism below eastern Indian Craton: evidence from trace elements, REE geochemistry and Sr Nd O isotope systematics of ultramafic dykes.Proceedings National Academy of Sciences India , Vol. 113, 4, pp. 649-666. Ingenta 1045680437IndiaMetasomatism, geochemistry
DS0512-0916
2004
Aggrawal, S.K.Roy, A., Sarkar, A., Jeyakumar, S., Aggrawal, S.K., Ebihara, M., Satoh, H.Late Archean mantle metasomatism below eastern Indian craton: evidence from trace elements, REE geochemistry and Sr Nd O isotope systematics of ultramafic dykes.Proceedings National Academy of Sciences India , Vol. 113, 4, pp. 649-665.India, AsiaPeridotite, harzburgite, geochronology
DS2002-1371
2002
Aggrawal, S.K.Roy, A., Sarkar, A., Jeyakumar, S., Aggrawal, S.K., Ebihara, M.Sm Nd age and mantle source characteristics of the Dhanjori volcanic rocks, eastern India.Geochemical Journal, Vol. 36, 5, pp. 503-18.IndiaGeochronology, magmatism
DS1990-1073
1990
Aggrey, K.E.Muenow, D.W., Garcia, M.O., Aggrey, K.E., Bednarz, U., SchminckeVolatiles in submarine glasses as a discriminant of tectonic origin:application to the Troodos ophioliteNature, Vol. 343, No. 6254, January 11, pp. 159-161CyprusOphiolite, Tectonic origin
DS1902-0314
2019
Aghajani, H.Roshanravan, B., Aghajani, H., Yousefi, M., Kreuzer, O.An improved prediction-area plot for prospectivity analysis of mineral deposits ( not specific to diamonds).Natural Resources Research, doi.org/10.1007/s11053-018-9439-7 17p.Iranchromite

Abstract: In this paper an improved prediction-area plot has been developed. This type of plot includes performance measures similar to other existing methods (receiver operating characteristics, success-rate curves and ordinary prediction-area plots) and, therefore, offers a reliable method for evaluating the performance of spatial evidence maps and prospectivity models. To demonstrate the reliability of the improved prediction-area plot proposed, we investigated the benefits of augmented targeting criteria through remotely sensed exploration features, compared to only geological map-derived criteria, for mineral prospectivity analysis using as an example the podiform chromite deposits of the Sabzevar Ophiolite Belt, Iran. The application of the newly developed improved prediction-area plot to the prospectivity models generated in this study indicated that the augmented targeting criteria by using remote sensing data perform better than non-updated geological map-derived criteria, and that model effectiveness can be improved by using an integrated approach that entails geologic remote sensing.
DS1980-0004
1980
AgidAgidProspects for Production Cooperation Between India and GhanaA.g.i.d. News, No. 24, JULY, PP. 30-31.India, Ghana, West AfricaDiamond Production
DS0912-0107
2009
Agnard, F.Chardon, D., Capais, D., Agnard, F.Flow of ultra hot orogens: a review from the Precambrian, clues for the Phanerozoic.Tectonophysics, Vol. 477, pp. 105-118.MantleUHP, orogens
DS1996-0008
1996
Agnerian, H.Agnerian, H.Survey of mineral property transactions July 1994- to June 1996Preprint from author, 11pGlobalRange of the values of mineral property transactions, Economics
DS1112-0007
2011
Agnew, J.Agnew, J., Daniels, A.Safe by accident. BooksafeByaccident.com, $ 21.95 USGlobalBook - on safety for mining industry
DS1998-0997
1998
Agnon, A.Meriaux, C., Agnon, A., Lister, J.R.The thermal signature of subducted lithospheric slabs at the core mantleboundary.Earth and Planetary Science Letters, Vol. 160, No. 3-4, Aug. 1, pp. 551-562.MantleSubduction, Boundary
DS1999-0472
1999
Agnon, A.Meriaux, C., Lister, J.R., Agnon, A.Dike propagation with distributed damage of the host rockEarth and Planetary Science Letters, Vol. 165, No. 2, Jan. 30, pp. 177-86.GlobalDike, Tectonics
DS1992-0860
1992
Agoshkov, V.M.Khodyrev, O.Yu., Agoshkov, V.M., Slutskiy, A.B.The system peridotite-aequeous fluid at upper mantle parametersDoklady Academy of Science USSR, Earth Science Section, Vol. 312, No. 1-3, June pp. 255-258MantleModel, Peridotite
DS1902-0289
2018
Agostinetti, N.P.Lamarque, G., Agostinetti, N.P., Julia, J., Evain, M.Joint interpretation of SKS-splitting measurements and receiver function data for detecting seismic anisotropy in the upper mantle: feasibility and limitations.AGU, 1p. abstract Mantlegeophysics -seismic

Abstract: Measuring seismic anisotropy within the Earth is essential as it constitutes a proxy for inferring upper mantle deformation related to mantle flow, that develops preferred orientations of the minerals in response to tectonic strain. The most-used method to detect anisotropy beneath a seismic station is the measurement of teleseismic SKS wave splitting on two horizontal recordings, i.e. measuring the delay time (dt) between two fast- and slow- polarized shear-waves and the orientation of polarization (F). This technique allows a integrative measurement (SKS data, hereinafter) that estimates the average F and dt along the entire SKS ray-path. Despite its importance for large-scale anisotropy within the upper mantle, the analysis of SKS data suffers from several limitations : (1) SKS data become difficult to interpret in regions where several anisotropic layers occur; (2) SKS waves fail to provide robust information about anisotropy related to thin layers; and (3) SKS data can investigate rock volumes with an horizontal symmetry axis only. During the last decade a new method, called harmonic decomposition of teleseismic Receiver Functions (RFs) has been developed in order to detect more complex anisotropic layering. This methodology is based on the extraction of back-azimuth harmonics of the RF dataset. Briefly, it constitutes a tool to appreciate the value of F and dt at every depth-level affording a detailed study of the rock anisotropy with both plunging and horizontal symmetry axis. RFs studies are however commonly limited to the first 10-15s of the signal and do not sample the deepest anisotropy. In this work we investigate in details both SKS data and RFs harmonic decomposition for a pool of stations deployed in northeastern Brasil, in order to understand how results from the analysis of these two observables can be jointly interpreted. We focus our study on the permanent station RCBR and on temporary seismic stations deployed in the area. We show that comparison and/or joint interpretation is not straightforward as both results can vary according to the amount of data available and their distribution in back-azimuth, and filtering. However, tacking into account those issues, the integration of these two observables represent a great step-forward for robust detection of upper mantle anisotropy.
DS0512-1095
2005
Agostini, S.Tonarini, S., Agostini, S., Innocent, F., Manetti, P.d11B as tracer of slab dehydration and mantle evolution in western Anatolia Cenozoic magmatism.Terra Nova, Vol. 17, 3, pp. 259-264.MantleMagmatism - not specific to diamonds
DS1612-2318
2016
Agostini, S.Lustrino, M., Agostini, S., Chalal, Y., Fedele, L., Stagno, V., Colombi, F., Bouguerra, A.Exotic lamproites or normal ultrapotassic rocks? The Late Miocene volcanic rocks from Kef Hahouner, NE Algeria, in the frame of the circum-Mediterranean lamproites.Journal of Volcanology and Geothermal Research, in press available 15p.Africa, AlgeriaLamproite

Abstract: The late Miocene (11-9 Ma) volcanic rocks of Kef Hahouner, ~ 40 km NE of Constantine (NE Algeria), are commonly classified as lamproites in literature. However, these rocks are characterized by an anhydrous paragenesis with plagioclase and Mg-rich olivine phenocrysts, set in a groundmass made up of feldspars, pyroxenes and opaque minerals. Thus, we classify the Kef Hahouner rocks as ultrapotassic shoshonites and latites, having K2O > 3 wt.%, K2O/Na2O > 2.5, MgO > 3-4 wt.%, SiO2 < 55-57 wt.% and SiO2/K2O < 15. All the investigated samples show primitive mantle-normalized multi-element patterns typical of orogenic (arc-type) magmas, i.e. enriched in LILE (e.g. Cs, Rb and Ba) and LREE (e.g. La/Yb = 37-59) with respect to the HFSE, peaks at Pb and troughs at Nb and Ta. Initial isotopic ratios are in the range of 87Sr/86Sr = 0.70874-0.70961, 143Nd/144Nd = 0.51222-0.51223, 206Pb/204Pb = 18.54-18.60, 207Pb/204Pb = 15.62-15.70 and 208Pb/204Pb = 38.88-39.16. The Kef Hahouner volcanic rocks show multi-element patterns similar to the other circum-Mediterranean lamproites and extreme Sr, Nd and Pb isotopic compositions. Nevertheless, the abundant plagioclase, the presence of Al-rich augite coupled with high Al2O3 whole rock compositions (9.6-21.4 wt.%), and the absence of phlogopite are all at inconsistent with the definition of lamproite. We reviewed the rocks classified as lamproites worldwide, and found that many of these rocks, as for the Kef Hahouner samples, should be actually defined as "normal" potassic to ultrapotassic volcanic rocks. Even the grouping of lamproites into "orogenic" and "anorogenic" types appears questionable.
DS1902-0293
2019
Agostini, S.Lustrino, M., Fedele, L., Agostini, S., Prelevic, D., Salari, G.Leucitites within and around the Mediterranean area. Lithos, Vol. 324-325, pp. 216-233.Europeleucitites

Abstract: Leucite-bearing volcanic rocks are commonly found within and around the Mediterranean area. A specific type of this rock group are leucitites. They are found both in a hinterland position of active and fossil subduction systems as well as in foreland tectonic settings, but none have been found in the Maghreb (N Africa) and Mashreq (Middle East) areas. Here a review of the main leucitite occurrences in the circum-Mediterranean area is presented, with new whole-rock, mineral chemical and Sr-Nd-Pb isotopic ratios on key districts, with the aim of clarifying the classification and genesis of this rock type. Many of the rocks classified in literature as leucitites do not conform to the IUGS definition of leucitite (i.e., rocks with >10?vol% modal leucite and with foids/(foids + feldspars) ratio?>?0.9, with leucite being the most abundant foid). Among circum-Mediterranean rocks classified as leucitites in the literature, we distinguish two types: clinopyroxene-olivine-phyric (COP) and leucite- phyric (LP) types. Only the second group can be truly classified as leucitite, being characterized by the absence or the very rare presence of feldspars, as well as by ultrapotassic composition. The COP group can be distinguished from the LP group on the basis of lower SiO2, Na2O?+?K2O, K2O/Na2O, Al2O3, Rb and Ba, and higher MgO, TiO2, Nb, Cr and Ni. The LP group shows multi-elemental patterns resembling magmas emplaced in subduction-related settings, while COP rocks are much more variable, showing HIMU-OIB-like to subduction-related-like incompatible element patterns. COP rocks are also characterized generally by more homogeneous isotopic compositions clustering towards low Sr and high Nd isotopic ratios, while LP leucitites plot all in the enriched Sr-Nd isotopic quadrant. LP rocks usually have lower 206Pb/204Pb and higher 207Pb/204Pb. This study shows that the geochemical signal of mantle melts does not always reflect the tectonic setting of magma emplacement, suggesting paying extreme attention in proposing geodynamic reconstructions on the basis of chemical data only.
DS0712-0004
2007
Agranier, A.Agranier, A., Lee, C-T.A.Quantifying trace element disequilibration temperatures in mantle xenoliths and abyssal peridotites.Earth and Planetary Science Letters, Vol. 257, 1-2, May 15, pp. 290-298.MantleGeochemistry
DS0412-0005
2004
Agrawal, P.K.Agrawal, P.K., Pandey, O.P.Unusual lithospheric structure and evolutionary pattern of the cratonic segments of the South Indian Shield.Earth Planets and Space, Vol. 56, 2, pp. 139-150. Ingenta 1043471076IndiaTectonics, eastern Dharwar Craton, geothermometry
DS1985-0484
1985
Agrawal, P.K.Negri, J.G., Agrawal, P.K., Thakur, N.K.Vertical Component Magsat Anomalies and Indian Tectonic Boundaries.Indian Academy of Science Proceedings, Vol. 94, No. 1, MARCH PP. 35-42.IndiaGeotectonics
DS2001-0885
2001
Agrawal, P.K.Pandey, O.P., Agrawal, P.K.Nature of lithospheric deformation beneath the western continental margin of India.Journal of Geological Society India, Vol. 57, No. 6, pp. 497-506.IndiaTectonics
DS2002-1210
2002
Agrawal, P.K.Pandrey, O.P., Agrawal, P.K., Chetty, T.R.K.Unusual lithospheric structure beneath the Hyderabad granitic region, eastern Dharwar craton, south India.Physics of the Earth and Planetary Interiors, Vol. 130, 1-2, pp.59-69.India, southHeat flow, Cratonic mantle lithosphere
DS0412-0006
2004
Agrawal, S.Agrawal, S., Guevara, M., Verma, S.P.Discriminate analysis applied to establish major element field boundaries for tectonic varieties of basic rocks.International Geology Review, Vol. 46, 7, pp. 575-594.TechnologyGeochemistry - not specific to diamonds
DS0612-0955
2005
Agredo, J.Munoz, M., Agredo, J., De Ignacio, C., Fernandez-Suarez, J., Jeffries, T.E.New dat a ( U Pb K Ar) on the geochronology of the alkaline carbonatitic association of Fuerteventura, Canary Islands, Spain.Lithos, Vol. 85, 1-4, Nov-Dec. pp. 140-153.Europe, SpainCarbonatite, Geochronology
DS1998-1161
1998
AgrinierPhilpott, P., Agrinier, ScambelluriChlorine cycling during subduction of altered oceanic crustMineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1169-70.MantleSubducion, Volatiles
DS2001-0658
2001
Agriniet, P.Laverne, C., Agriniet, P., Hermitte, D., Bohn, M.Chemical fluxes during hydrothermal alteration of 1200 m long section of dikes in the oceanic crust Hole 504B.Chemical Geology, Vol. 181,No. 1-4, pp. 73-98.GlobalDike - sheeted, ophiolite, dolerite, Geochemistry
DS1412-0004
2013
Agrosi, G.Agrosi, G., Tempesta, G., Scandael, E., Harris, J.W.Growth and post-growth defects in a diamond from Finsch mine ( South Africa).European Journal of Mineralogy, Vol. 25, pp. 551-559.Africa, South AfricaDeposit - Finsch
DS1604-0589
2016
Agrosi, G.Agrosi, G., Nestola, F., Tempestra, G., Bruno, M., Scandale, E., Harris, J.X-ray topographic study of a diamond from Udachnaya: implications for the genetic nature of inclusions.Lithos, Vol. 248-251, pp. 153-159.RussiaDeposit - Udachnaya

Abstract: In recent years, several studies have focused on the growth conditions of the diamonds through the analysis of the mineral inclusions trapped in them. In these studies, it is crucial to distinguish between protogenetic, syngenetic and epigenetic inclusions. X-ray topography (XRDT) can be a helpful tool to verify, in a non-destructive way, the genetic nature of inclusions in diamond. With this aim, a diamond from the Udachnaya kimberlite, Siberia, was investigated. The diamond, previously studied by Nestola et al. (2011), has anomalous birefringence and the two largest olivines have typical “diamond-imposed” shapes. The study of the topographic images shows that the diamond exhibits significant deformation fields related to post growth plastic deformation. The absence of dislocations starting from the olivine inclusions, and the dark contrasts around them represent the main results obtained by XRDT, contributing to the elucidation of the relationships between the diamond and the olivines at the micron-meter scale. The dark halo surrounding the inclusions was likely caused by the effect of different thermo-elastic properties between the diamond and the inclusions. The absence of dislocations indicates that the diamond-imposed morphology did not produce the volume distortion commonly associated with the entrapment of the full-grown inclusions and, thus, only based on such evidence, a syngenetic origin could be proposed. In addition, stepped figures optically observed at the interface between diamond and one of the olivines suggest processes of selective partial dissolution that would contribute to a change in the final morphology of inclusions. These results show that a diamond morphology may be imposed to a full-grown (protogenetic) olivine during their encapsulation, suggesting that the bulk of the inclusion is protogenetic, whereas its more external regions, close to the diamond-inclusion interface, could be syngenetic.
DS1705-0806
2017
Agrosi, G.Agrosi, G., Tempesta, G., Mele, D., Allegretta, I., Teranzo, R., Nestola, F.Multi analytical approach for non-destructuve analyses of a diamond from Udachnaya and its trapped inclusions: the first report of (fe, Ni) 1+xS machinawite sulphide in diamonds.European Geosciences Union General Assembly 2017, Vienna April 23-28, 1p. 5374 AbstractRussiaDeposit - Udachnaya

Abstract: The study of diamonds and the mineral inclusions trapped in them is of great interest for Earth science, since they can provide insight about deep mantle conditions and its evolution. The conventional techniques commonly used are destructive and thus do not allow the employment of different methods used simultaneously to obtain integrated and complementary results. Significant information about the growth conditions of diamonds and their inclusions still trapped within them can be preferably obtained by in situ investigation. In this study, we propose a multi-analytical approach, using a set of non-destructive techniques with conventional sources, to investigate one diamond from Udachnaya kimberlite (Siberia, Russia). The combined use of micro-X-ray Tomography, micro-X-ray Fluorescence, X-Ray Powder Diffraction and micro-Raman spectroscopy, allowed us to determine the spatial distribution of the inclusions, their chemical and mineralogical composition and, finally, the paragenetic suite, totally preserving the diamond host. The sample was also studied by means of X-ray Diffraction Topography to characterize the structural defects and to obtain genetic information about the growth history of the diamond. The combination of the different data provided a sort of «mapping» of a diamond. The X-Ray Topographic images show that the sample investigated exhibits plastic deformation. Actually, one set of {111} slip lamellae, corresponding to polysynthetic twinning, affect the whole sample. The tomographic images reveal that the primary inclusions, not observable optically, show a poly-faceted shape corresponding to an assemblage of tiny crystals. The chemical data display that the trapped minerals are mono-sulphides of Fe, Ni. The diagrams obtained by the X-Ray diffraction reveal that the inclusions mainly consist of an assemblage of tiny crystals of pentlandite and pyrrothite. Nevertheless, a thorough analysis of the diffraction data suggests the presence of another mono-sulphide of Fe,Ni: mackinawite. Raman spectra taken on these inclusions confirm, for the first time, the presence of this metastable phase as inclusion in diamond. The genetic implications of these results are discussed.
DS1712-2668
2017
Agrosi, G.Agrosi, G., Tempesta, G., Mele, D., Allegretta, I., Terzano, R., Shirery, S.B., Pearson, G.D., Nestola, F.Non-destructive, multi-method, internal analysis of multiple inclusions in a single diamond: first occurrence of mackinawite ( Fe,Ni)1+xSAmerican Mineralogist, Vol. 102, pp. 2235-2243.Russia, Siberiadeposit - Udachnaya

Abstract: A single gem lithospheric diamond with five sulfide inclusions from the Udachnaya kimberlite (Siberia, Russia) has been analyzed non-destructively to track the growth conditions of the diamond. Sulfides are the most abundant mineral inclusions in many lithospheric diamond crystals and are the most favorable minerals to date diamond crystals by Re-Os isotope systematics. Our investigation used non-destructive, micro-techniques, combining X-ray tomography, X-ray fluorescence, X-ray powder diffraction, and Raman spectroscopy. This approach allowed us to determine the spatial distribution of the inclusions, their chemical and mineralogical composition on the microscale, and, finally, the paragenetic association, leaving the diamond host completely unaffected. The sample was also studied by X-ray diffraction topography to characterize the structural defects of the diamond and to obtain genetic information about its growth history. The X-ray topographic images show that the sample investigated exhibits plastic deformation. One set of {111} slip lamellae, corresponding to polysynthetic twinning, affects the entire sample. Chemical data on the inclusions still trapped within the diamond show they are monosulfide solid solutions of Fe, Ni and indicate a peridotitic paragenesis. Micro-X-ray diffraction reveals that the inclusions mainly consist of a polycrystalline aggregate of pentlandite and pyrrothite. A thorough analysis of the Raman data suggests the presence of a further Fe, Ni sulfide, never reported so far in diamonds: mackinawite. The total absence of any oxides in the sulfide assemblage clearly indicates that mackinawite is not simply a “late” alteration of pyrrhotite and pentlandite due to secondary oxidizing fluids entering diamond fractures after the diamond transport to the surface. Instead, it is likely formed as a low-temperature phase that grew in a closed system within the diamond host. It is possible that mackinawite is a more common phase in sulfide assemblages within diamond crystals than has previously been presumed, and that the percentage of mackinawite within a given sulfide assemblage could vary from diamond to diamond and from locality to locality.
DS1712-2669
2017
Agrosi, G.Agrosi, G., Tempestra, G., Della Ventura, G., Guidi, M., Hutchison, M., Nimis, P., Nestola, F.Non-destructive in situ study of plastic deformations in diamonds: x-ray diffraction topography and micro-FTIR mapping of two super deep diamond crystals from Sao Luiz ( Juina, Brazil).Crystals, Vol. 7, #233South America, Brazildeposit - Juina

Abstract: Diamonds from Juina, Brazil, are well-known examples of superdeep diamond crystals formed under sublithospheric conditions and evidence would indicate their origins lie as deep as the Earth's mantle transition zone and the Lower Mantle. Detailed characterization of these minerals and of inclusions trapped within them may thus provide precious minero-petrogenetic information on their growth history in these inaccessible environments. With the aim of studying non-destructively the structural defects in the entire crystalline volume, two diamond samples from this locality, labelled JUc4 and BZ270, respectively, were studied in transmission mode by means of X-ray Diffraction Topography (XRDT) and micro Fourier Transform InfraRed Spectroscopy (µFTIR). The combined use of these methods shows a good fit between the mapping of spatial distribution of extended defects observed on the topographic images and the µFTIR maps corresponding to the concentration of N and H point defects. The results obtained show that both samples are affected by plastic deformation. In particular, BZ270 shows a lower content of nitrogen and higher deformation, and actually consists of different, slightly misoriented grains that contain sub-grains with a rounded-elongated shape. These features are commonly associated with deformation processes by solid-state diffusion creep under high pressure and high temperature.
DS1901-0001
2017
Agrosi, G.Agrosi, G., Tempesta, G., Della Ventura, G., Cestelli Guidi, M., Hutchison, M., Nimis, P., Nestola, F.Non-destructive in situ study of plastic deformation in diamonds: X-ray diffraction topography and uFTIR mapping of two super deep diamond crystals from Sao Luiz ( Juina, Brazil).Crystals MDPI, Vol. 7, 8, 11p. Doi.org/10. 3390/cryst7080233South America, Brazildeposit - Juina

Abstract: Diamonds from Juina, Brazil, are well-known examples of superdeep diamond crystals formed under sublithospheric conditions and evidence would indicate their origins lie as deep as the Earth’s mantle transition zone and the Lower Mantle. Detailed characterization of these minerals and of inclusions trapped within them may thus provide precious minero-petrogenetic information on their growth history in these inaccessible environments. With the aim of studying non-destructively the structural defects in the entire crystalline volume, two diamond samples from this locality, labelled JUc4 and BZ270, respectively, were studied in transmission mode by means of X-ray Diffraction Topography (XRDT) and micro Fourier Transform InfraRed Spectroscopy (µFTIR). The combined use of these methods shows a good fit between the mapping of spatial distribution of extended defects observed on the topographic images and the µFTIR maps corresponding to the concentration of N and H point defects. The results obtained show that both samples are affected by plastic deformation. In particular, BZ270 shows a lower content of nitrogen and higher deformation, and actually consists of different, slightly misoriented grains that contain sub-grains with a rounded-elongated shape. These features are commonly associated with deformation processes by solid-state diffusion creep under high pressure and high temperature.
DS1902-0304
2019
Agrosi, G.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.
DS1212-0007
2012
Agrusta, R.Agrusta, R., Tommasi, A.Lithosphere thinning by small scale convection in a plume fed low viscosity layer beneath a moving plate.emc2012 @ uni-frankfurt.de, 1p. AbstractMantlePlume
DS1602-0187
2015
Agrusta, R.Agrusta, R., Tommasi, A., Arcay, D., Gonzalez, A., Gerya, T.How partial melting affects small-scale convection in a plume-fed sublithospheric layer beneath fast-moving plates.Geochemistry, Geophysics, Geosystems: G3, Vol. 16, 11, Nov. pp. 3924-3945.MantleConvection

Abstract: Numerical models show that small-scale convection (SSC) occurring atop a mantle plume is a plausible mechanism to rejuvenate the lithosphere. The triggering of SSC depends on the density contrast and on the rheology of the unstable layer underlying the stagnant upper part of the thermal boundary layer (TBL). Partial melting may change both properties. We analyze, using 2-D numerical simulations, how partial melting influences the dynamics of time-dependent SSC instabilities and the resulting thermo-mechanical rejuvenation of an oceanic plate moving atop of a plume. Our simulations show a complex behavior, with acceleration, no change, or delay of the SSC onset, due to competing effects of the latent heat of partial melting, which cools the plume material, and of the buoyancy increase associated with both melt retention and depletion of residue following melt extraction. The melt-induced viscosity reduction is too localized to affect significantly SSC dynamics. Faster SSC triggering is promoted for low melting degrees (low plume temperature anomalies, thick lithosphere, or fast moving plates), which limit both the temperature reduction due to latent heat of melting and the accumulation of depleted buoyant residue in the upper part of the unstable layer. In contrast, high partial melting degrees lead to a strong temperate decrease due to latent heat of melting and development of a thick depleted layer within the sublithospheric convecting layer, which delay the development of gravitational instabilities. Despite differences in SSC dynamics, the thinning of the lithosphere is not significantly enhanced relatively to simulations that neglect partial melting.
DS1704-0615
2017
Agrusta, R.Agrusta, R., Goes, S., van Hunen, J.Subducting slab transition zone interaction: stagnation, penetration and mode switches.Earth and Planetary Science Letters, Vol. 464, pp. 10-23.MantleSubduction

Abstract: Seismic tomography shows that subducting slabs can either sink straight into the lower mantle, or lie down in the mantle transition zone. Moreover, some slabs seem to have changed mode from stagnation to penetration or vice versa. We investigate the dynamic controls on these modes and particularly the transition between them using 2D self-consistent thermo-mechanical subduction models. Our models confirm that the ability of the trench to move is key for slab flattening in the transition zone. Over a wide range of plausible Clapeyron slopes and viscosity jumps at the base of the transition zone, hot young slabs (25 Myr in our models) are most likely to penetrate, while cold old slabs (150 Myr) drive more trench motion and tend to stagnate. Several mechanisms are able to induce penetrating slabs to stagnate: ageing of the subducting plate, decreasing upper plate forcing, and increasing Clapeyron slope (e.g. due to the arrival of a more hydrated slab). Getting stagnating slabs to penetrate is more difficult. It can be accomplished by an instantaneous change in the forcing of the upper plate from free to motionless, or a sudden decrease in the Clapeyron slope. A rapid change in plate age at the trench from old to young cannot easily induce penetration. On Earth, ageing of the subducting plate (with accompanying upper plate rifting) may be the most common mechanism for causing slab stagnation, while strong changes in upper plate forcing appear required for triggering slab penetration.
DS1707-1329
2017
Agrusta, R.Goes, S., Agrusta, R., van Hunen, J., Garel, F.Subduction - transition zone interaction: a review.Geosphere, Vol. 13, 3, pp. 644-8.Mantlesubduction

Abstract: As subducting plates reach the base of the upper mantle, some appear to flatten and stagnate, while others seemingly go through unimpeded. This variable resistance to slab sinking has been proposed to affect long-term thermal and chemical mantle circulation. A review of observational constraints and dynamic models highlights that neither the increase in viscosity between upper and lower mantle (likely by a factor 20–50) nor the coincident endothermic phase transition in the main mantle silicates (with a likely Clapeyron slope of –1 to –2 MPa/K) suffice to stagnate slabs. However, together the two provide enough resistance to temporarily stagnate subducting plates, if they subduct accompanied by significant trench retreat. Older, stronger plates are more capable of inducing trench retreat, explaining why backarc spreading and flat slabs tend to be associated with old-plate subduction. Slab viscosities that are ~2 orders of magnitude higher than background mantle (effective yield stresses of 100–300 MPa) lead to similar styles of deformation as those revealed by seismic tomography and slab earthquakes. None of the current transition-zone slabs seem to have stagnated there more than 60 m.y. Since modeled slab destabilization takes more than 100 m.y., lower-mantle entry is apparently usually triggered (e.g., by changes in plate buoyancy). Many of the complex morphologies of lower-mantle slabs can be the result of sinking and subsequent deformation of originally stagnated slabs, which can retain flat morphologies in the top of the lower mantle, fold as they sink deeper, and eventually form bulky shapes in the deep mantle.
DS1901-0035
2017
Agrusta, R.Goes, S., Agrusta, R., van Hunen, J., Garel, F.Subduction - transition zone interaction: a review.Geosphere, Vol. 13, 3, pp. 644-664.Mantlesubduction

Abstract: As subducting plates reach the base of the upper mantle, some appear to flatten and stagnate, while others seemingly go through unimpeded. This variable resistance to slab sinking has been proposed to affect long-term thermal and chemical mantle circulation. A review of observational constraints and dynamic models highlights that neither the increase in viscosity between upper and lower mantle (likely by a factor 20-50) nor the coincident endothermic phase transition in the main mantle silicates (with a likely Clapeyron slope of -1 to -2 MPa/K) suffice to stagnate slabs. However, together the two provide enough resistance to temporarily stagnate subducting plates, if they subduct accompanied by significant trench retreat. Older, stronger plates are more capable of inducing trench retreat, explaining why backarc spreading and flat slabs tend to be associated with old-plate subduction. Slab viscosities that are ~2 orders of magnitude higher than background mantle (effective yield stresses of 100-300 MPa) lead to similar styles of deformation as those revealed by seismic tomography and slab earthquakes. None of the current transition-zone slabs seem to have stagnated there more than 60 m.y. Since modeled slab destabilization takes more than 100 m.y., lower-mantle entry is apparently usually triggered (e.g., by changes in plate buoyancy). Many of the complex morphologies of lower-mantle slabs can be the result of sinking and subsequent deformation of originally stagnated slabs, which can retain flat morphologies in the top of the lower mantle, fold as they sink deeper, and eventually form bulky shapes in the deep mantle.
DS0812-0006
2008
AGS LaboratoriesAGS Laboratories'The Real Ideal' - AGS Laboratories defines the Real Ideal cut diamond.AGS Laboratories, July 21, 1p.TechnologyNews item - American Gem Society Laboratories
DS1994-0028
1994
AGSOAGSORegolith conference abstract volumeAgso, $ 15.00AustraliaBook ad -regolith, Laterites, ferricretes, silcretes
DS1994-0029
1994
AGSOAGSO12 map Kalimantan 1: 250, 000 geoscientific series completed by AGSOAus Geo News, No. 22, June p. 8.GlobalMap -ad
DS1995-0010
1995
AGSOAGSOThe regolith .... featured thematic issueAgso Journal Of Australian Geol. And Geophysics, AustraliaBook -ad, Regolith thematic issue
DS1996-0009
1996
AGSOAGSOAustralian impact structuresAgso, Vol. 16, No. 4, pp. 371-620AustraliaImpact structures, Table of contents
DS1996-0010
1996
AGSOAGSOMaps- new 1:100, 000 geological maps of the East KimberleyAustralian Geological Survey Organization, Maps, paper or digitalAustraliaMaps, Kimberley region, Halls Creek
DS1997-0009
1997
AGSOAGSODepth to magnetic basement mapsAgso, AustraliaExploration, Basement
DS1997-0010
1997
AGSOAGSOComparative Paleoproterozoic tectonics and metallogenesis in Australian and Fennoscandian shieldsAgso, Australia, Fennoscandia, Baltic shieldBook - ad, Metallogeny
DS1112-0008
2011
Agterberg, F.Agterberg, F.A modified weights-of-evidence method for regional mineral resource estimation.Natural Resources Research, Vol.20, 2, pp. 95-TechnologySpatial modeling, logistic regression
DS1112-0009
2011
Agterberg, F.Agterberg, F.A modified weights of evidence method for regional mineral resource estimation.Natural Resources Research, Vol. 20, 2, June pp. 95-TechnologyEconomics - not specific to diamonds
DS0612-1302
2006
Agterberg, F.P.Sim, B.L., Agterberg, F.P.A conceptual model for kimberlite emplacement by solitary interfacial mega-waves on the core mantle boundary.Journal of Geodynamics, Vol. 41, 5, July, pp. 451-461.MantleConvection, magnetics, D layer Rogue waves ULVZ
DS0612-1303
2006
Agterberg, F.P.Sim, B.L., Agterberg, F.P.A conceptual model for kimberlite emplacement by solitary interfacial megawaves on the core mantle boundary.Journal of Geodynamics, Vol. 41, 5, pp. 451-461.MantleGeophysics
DS1993-0014
1993
Agterberg, F.P.Agterberg, F.P., Cheng, Q., Wright, D.F.Fractal modelling of mineral depositsApcom Xxiv, pp. 43-53British ColumbiaGeostatistics, Mineral potential, Deposit -Sulphurets
DS1993-0559
1993
Agterberg, F.P.Goodacre, A.K., Bonham-Carter, G.F., Agterberg, F.P., Wrightm D.F.A statistical analysis of the spatial association of seismicity with drainage patterns and magnetic anomalies in western QuebecTectonophysics, Vol. 217, No. 3-4, January 30, pp. 285-306QuebecGeomorphology, Geophysics -seismics
DS1995-0011
1995
Agterberg, F.P.Agterberg, F.P.Multifractal modeling of the sizes and grades of giant and supergiantdepositsInternational Geology Review, Vol. 37, No. 1, Jan. pp. 1-8GlobalGiant ore deposits, Model -fractals
DS1997-0011
1997
Agterberg, F.P.Agterberg, F.P.Multifractal modelling of the sizes and grades and supergiant depositsGlobal Tectonics and Metallogeny, Vol. 6, No. 2, March pp. 131-136GlobalModelling - fractals, discoveries, Deposits - giant
DS0412-0007
2003
Ague, J.Ague, J.Fluid flow in the deep crust.Treatise on Geochemistry, Holland Editor, Volume 3, pp. 195-228.MantleGeochemistry, chemical transport
DS1412-0043
2013
Ague, J.I.Baxter, E.F., Caddick, M.J., Ague, J.I.Garnet: common mineral, uncommonly useful.Elements, Vol. 9, 6, Dec. pp. 415-420.MantleGarnet mineralogy
DS0612-1530
2006
Ague, J.J.Wilbur, D.E., Ague, J.J.Chemical disequilibrium during garnet growth: Monte Carlo simulations of natural crystal morphologies.Geology, Vol. 34, 8, August pp. 689-692.TechnologyMetamorphism, crystal growth - not specific to diamond
DS0912-0463
2009
Ague, J.J.Lyubetskaya, T., Ague, J.J.Effect of metamorphic reactions on thermal evolution in collisional orogens.Journal of Metamorphic Geology, Vol. 27, 8, pp. 579-600.MantleGeothermometry
DS1412-0005
2013
Ague, J.J.Ague, J.J., Carlson, W.D.Metamorphism as garnet sees it: the kinetics of nucleation and growth, equilibrium, and diffusional relaxation.Elements, Vol. 9, 6, Dec. pp. 439-445.MantleCrystallography
DS1501-0001
2014
Ague, J.J.Ague, J.J.Deep carbon: subduction goes organic.Nature Geoscience, 2p.MantleCarbon

Abstract: Aqueous subduction-zone fluids contain CO2 and methane. New calculations indicate that these fluids also host a wide array of organic carbon species, in concentrations sufficient to influence the deep carbon cycle.
DS1711-2507
2017
Ague, J.J.Chu, X., Ague, J.J., Podladchikov, Y.Y., Tian, M.Ultrafast eclogite formation via melting induced overpressure.Earth and Planetary Science Letters, Vol. 479, pp. 1-17.Mantleeclogite

Abstract: The conventional wisdom holds that metamorphic reactions take place at pressures near-lithostatic so that the thermodynamic pressure, reflected by the mineral assemblage, is directly correlated with depth. On the other hand, recent field-based observations and geodynamic simulations suggest that heterogeneous stress and significant pressure deviations above lithostatic (overpressure) can occur in Earth's crust. Here we show that eclogite, normally interpreted to form at great depths in subduction zones and Earth's mantle, may form at much shallower depths via local overpressure generated in crustal shear zones. The eclogites studied crop out as lenses hosted by felsic paragneiss in a sheared thrust slice and represent a local pressure and temperature anomaly in the Taconic orogenic belt, southern New England. Sharply-defined chemical zones in garnet, which record ~5 kbar pressure rise and fall accompanied by a temperature increase of 150-200?°C, demonstrate extremely short timescales of diffusion. This requires anomalously fast compression (~500 yrs) and decompression. We use coupled phase equilibria and garnet diffusion forward modeling to fit the observed garnet profiles and test the likely paths using a Monte Carlo-type approach, accounting for off-center sectioning of garnet. The simulation shows that a ~5 kbar pressure increase after the temperature peak is necessary to reproduce the garnet zoning. Remarkably, this post-peak-T compression (from 9 kbar to 14 kbar) lasted only ~500 yrs. If the compression was due to burial along a lithostatic pressure gradient, the descent speed would exceed 30 m?yr-1, defying any observed or modeled subduction rates. Local overpressure in response to partial melting in a confined volume (Vrijmoed et al., 2009) caused by transient shear heating can explain the ultra-fast compression without necessitating burial to great depth.
DS1999-0005
1999
Ague, J.J.Ague, J.J., Rye, D.M.Simple models of CO2 release from metacarbonates with implications for interpretation of directions...Journal of Petrology, Vol. 40, No. 9, Sept. pp. 1443-Mantle, crustCarbonatization, Model - Flow
DS1709-2043
2017
Aguiar, A.L.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.
DS1910-0549
1918
Aguilar y santillan, R.Aguilar y santillan, R.Bibliografia Geologica Y Minera de la Republica MexicanaMexico Department Minas Bol. Minero, 97P.MexicoBlank
DS1910-0231
1912
Aguillon, L.Aguillon, L.Note sur le Regime Legal des Mines Au Congo BelgeAnnual DES Mines, Vol. 1, PT. 1, 24P.Democratic Republic of CongoMining, History, Law
DS2000-0225
2000
Aguirre-Diaz, G.J.Delgado Granados, H., Aguirre-Diaz, G.J., Stock, J.M.Cenozoic tectonics and volcanism of MexicoGeological Society of America Special paper, No. 334, 300p.MexicoBook - table of contents
DS1987-0003
1987
Agyei, E.K.Agyei, E.K., Van Landewijk, J.E.J.M., Armstrong, R.L., Harakal, J.E.Rubidium-strontium and potassium-argon geochronometry of southeasternGhanaJournal of African Earth Science, Vol. 6, No. 2, pp. 153-161GhanaCarbonatite
DS2001-0579
2001
AhallKarlstrom, R.E., Ahall, Harlam, Williams, McLellandLong lived (1.8-1.0) Ga convergent Orogen in southern Laurentia: its extensions to Australia and Baltica....Precambrian Research, Vol. 111, No. 1-4, pp. 5-30.Australia, Norway, BalticaRodinia - tectonics, Orogeny
DS1997-0012
1997
Ahall, K.I.Ahall, K.I., Gower, C.F.The Gothian and Labradorian orogens: variations in accretionary tectonismalong Paleoproterozoicmargin..Gff., Vol. 119, pp. 181-191.Scandinavia, LabradorOrogeny, Laurentia-Baltica
DS1998-0013
1998
Ahall, K.I.Ahall, K.I., Connelly, J.Intermittent 1.53 - 1.13 Ga magmatism in western Baltica: age constraints and correlations...Precambrian Research, Vol. 92, No. 1, Sept. 1, pp. 1-20.Europe, Baltic ShieldSupercontinent, geochronology, Tectonics
DS1998-0014
1998
Ahall, K.I.Ahall, K.I., Cornell, D.H., Armstrong, R.Ion probe zircon dating of metasedimentary units across the Skagerrak: new constraints early Mesoproterozoic.Precambrian Research, Vol. 87, No. 3-4, Feb. 1, pp. 117-134Sweden, Norway, Finland, Baltic ShieldGeochronology
DS2000-0009
2000
Ahall, K.I.Ahall, K.I., Connelly, J.N., Brewer, T.S.Episodic rapakivi magmatism due to distal orogenesis? correlation of 1.69-1.50 Ga orogenic and inboard....Geology, Vol. 28, No. 9, Sept. pp. 823-6.Baltic Shield, Norway, Sweden, Finland, Russia, KolaMagmatism, Orogenic growth
DS2000-0010
2000
Ahall, K.I.Ahall, K.I., Larson, S.A.Growth related 1.85-1.55 Ga magmatism in the Baltic Shield: a review addressing tectonics characteristics.Gff., Vol. 122, pp. 193-206.Finland, Norway, Sweden, Baltic States, FennoscandiaTransscandinavian Igneous Belt, Magmatism, Tectonics
DS2001-0010
2001
Ahall, K.I.Ahall, K.I., Brewer, T.S., Connelly, J.N.Deciphering the complex accretionary growth history of the Baltic Shield between 1.7 - 1.5 Ga and links...Geological Association of Canada (GAC) Annual Meeting Abstracts, Vol. 26, p.1, abstract.Baltic Shield, Baltica, LaurentiaMagmatism - intracontinental
DS2002-0205
2002
Ahall, K.I.Brewer, T.S., Ahall, K.I., Darbyshire, D., Menuge, J.Geochemistry of late Mesoproterozoic volcanism in southwestern Scandinavia: implications for ...plate..Journal of Geological Society of London, Vol. 159, 2, pp. 129-44.ScandinaviaSveconorwegian Grenvillian plate tectonic models, Tectonics
DS1997-0013
1997
Aharonov, E.Aharonov, E., et al.Three dimensional flow and reaction in porous media: implications forearth's mantle and sedimentary basinsJournal Geophys. Research, Vol. 102, No. 7, July 10, pp. 14821-34.MantleGeophysics, Flow
DS2001-1112
2001
Aharonov, E.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
DS1989-0011
1989
Ahern, J.L.Ahern, J.L., Dikeou, P.J.Evolution of the lithosphere beneath the Michigan basinEarth and Planetary Science Letters, Vol. 95, No. 1, /2, October pp. 73-84MichiganTectonics, Mantle
DS0412-0438
2004
Ahijado, A.Demeny, A., Vennemann, T.W., Ahijado, A., et al.Oxygen isotope thermometry in carbonatites, Fuerteventura Canary Islands, Spain.Mineralogy and Petrology, Vol. 80, 3-4, March pp. 155-172.Europe, Canary IslandsCarbonatite
DS0812-0281
2008
Ahijado, A.Demeny, A., Casilla, R., Ahijado, A., De la Nuez, J., Milton, A.J., Nagy, G.Carbonate xenoliths in La Palma: carbonatite or alteration product?Chemie der Erde, Vol. 68, 4, pp. 369-381.Europe, SpainCarbonatite
DS0812-0282
2008
Ahijado, A.Demeny, A., Casillas, R., Ahijado, A., La Nuez, J.de, Milton, J.A., Nagy, G.Carbonate xenoliths in La Palma: carbonatite or alteration product?Chemie der Erde, Vol. 68, 4, pp. 369-381.Europe, Canary IslandsGeochronology
DS1112-0152
2011
Ahijado, A.Casillas, R., Demeny, A., Nagy, G., Ahijado, A., Fernandez, C.Metacarbonatites in the Basal Complex of Fuerteventura ( Canary Islands). The role of fluid/rock interactions during contact metamorphism and anatexis.Lithos, Vol. 125, pp. 503-520.Europe, Canary IslandsCarbonatite
DS2001-0011
2001
Ahijado, A.Ahijado, A., Casillas, R., Hernandez-Pacheco, A.The dike swarms of the Amanay Massif, Fuerteventura, Canary Islands (Spain)Journal of African Earth Sciences, Vol. 19, No. 3, Apr. pp.333-46.GlobalAlkaline rocks, Dike Swarms
DS1806-1209
2018
Ahline, N.Ardon, T., Ahline, N.Fancy deep brown-orange CVD synthetic diamond. 0.56 ctGems & Gemology, Vol. 54, 1, p. 64Technologysynthetics
DS1312-0011
2013
Ahlqvist, O.Ahlqvist, O., Harvey, F., Ban, H., Chen, W., Fonanella, S., Guo, M.,Singh, N.Making journal articles 'live': turning academic writing into scientific dialog.Geojournal, Vol. 78, 1, pp. 61-68.TechnologyKnowledge dissemination
DS1950-0248
1956
Ahmad, F.Ahmad, F.On the Source of the Panna Diamonds and the Nature of the Majhgawan Plug.Indian Sci. Congr. 43rd. Session Proceedings, ABSTRACT.India, Madhya PradeshBlank
DS1980-0117
1980
Ahmad, S.N.Ehrenberg, S.N., Ahmad, S.N., Perry, E.C.JR.Oxygen Isotopic Compositions of Garnet Granulites from Colorado Plateau Diatremes.Eos, Vol. 61, No. 17, APRIL 22ND. P. 387.United States, Colorado PlateauBlank
DS0412-0861
2004
Ahmad, T.Hussein, M.F., Mondal, MEA, Ahmad, T.Petrological and geochemical characteristics of Archean gneisses and granitoids from Bastar Craton, central India - implicationGondwana Research, Vol. 7, 2, pp. 531-538.IndiaSubduction
DS0812-0007
2008
Ahmad, T.Ahmad, T., Deb, M., Tarney, J., Raza, M.Proterozoic mafic volcanism in the Aravalli Delhi orogen, northwest India: geochemistry and tectonic framework.Journal of Geological Society of India, Vol. 72, 1, pp. 93-112.IndiaTectonics
DS0812-0008
2008
Ahmad, T.Ahmad, T., Jayananda, M.Plutonism and Precambrian magmatism in India.Glimpses of Geoscience Research in India, The Indian report to IUGS 2004-08, pp. 160-173.IndiaShield areas
DS0812-0760
2008
Ahmad, T.Mondal, M.E.A., Chandra, R., Ahmad, T.Precambrian mafic magmatism in Bundelk hand Craton.Journal of Geological Society of India, Vol. 72, 1, pp. 113-122.IndiaMagmatism
DS0812-1107
2008
Ahmad, T.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
DS1012-0512
2010
Ahmad, T.Mondal, M.E.A., Hussain, M.F., Ahmad, T.Mafic dyke swarms of central Indian shield: implications for a pre-Rodinia supercontinent assembly.International Dyke Conference Held Feb. 6, India, 1p. AbstractIndiaDeposit - Bunder
DS1998-0015
1998
Ahmadian, A.Ahmadian, A., Kitamura, M.Morphology of spinel twinned crystals of natural diamondIma 17th. Abstract Vol., p. A 83, abstractSouth Africa, RussiaDiamond morphology
DS2002-0011
2002
Ahmadjan, A.Ahmadjan, A., Kitamura, M.Re-entrant and salient corner effects of spinel twinned natural diamond18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.147.MantleDiamond - morphology
DS1950-0001
1950
Ahman, E.Ahman, E.Ett Fynd Av Frisk Olivin I Kimberlit Fran Kalix Skargard I Norrbotten.Geol. Foren. Forhandl., Vol. 72, PP. 207-211.Sweden, ScandinaviaKimberlite, Alnoite
DS1950-0050
1951
Ahman, E.Ahman, E.Ett Blockfynd Av Ovanlig Art Fran Kalix SkargardGeol. Foren. Forhandl., Vol. 73, PP. 603-607.Sweden, ScandinaviaAlnoite
DS1960-0002
1960
Ahman, E.Ahman, E.The Kalix AreaInternational Geological Congress, 21 ST., GUIDE BOOK A 32 and C 26, PP. 23-26.Sweden, ScandinaviaAlnoite
DS1960-0772
1967
Ahman, E.Ahman, E.Vastra Graddmanhallan Island, Kalix Archipelago, NorrbottenGeol. Foren. Forhandl., Vol. 89, PT. 1, No. 528, PP. 50-61.Norway, ScandinaviaPetrography
DS1981-0254
1981
Ahman, E.Kresten, P., Ahman, E., Brunfelt, A.O.Alkaline Ultramafic Lamprophyres and Associated Carbonatite dykes from the Kalix Area, Northern Sweden.Geologische Rundschau, Vol. 70, No. 3, PP. 1215-1231.Sweden, ScandinaviaAlnoite
DS1511-1819
2014
Ahmat, A.L.Ahmat, A.L.The Ellendale diamond field: exploration history, discovery, geology and mining.Australian Gemmologist, Vol. 24, 12, pp. 280-288.AustraliaDeposit - Ellendale

Abstract: The Ellendale diamond field in West Kimberley is one of only three hard-rock diamond mine locations in Australia. Though not the first Australian diamond mine, Ellendale was the country’s first hard-rock deposit. It holds a special place in world diamond history as it led in November 1976 to the recognition of a new host-rock for diamond, olivine lamproite. Up until that time, commercial-sized diamonds were considered to be sourced only from kimberlite. The Ellendale lamproites are geologically very young, only 22 Ma (million of years) old. Within several years of the initial discovery, some 46 lamproite pipes were found at Ellendale. By 1980, 38 of these pipes had been assessed for their diamond content. More than two decades later, geologists from the Kimberley Diamond Company (KDC) recognized eluvial diamond enrichment over these pipes. After a lengthy legal battle, they wrested the Ellendale mining lease from the Ashton Joint Venture and commenced mining there in May 2002. Ellendale is recognized as a source of high-value fancy yellow diamonds. These high priced stones have been marketed through a special deal with Tiffany & Co since 2009. But the future of mining there is tenuous. Ellendale 4 was closed in 2009, and the high Australian dollar, combined with dwindling reserves, may jeopardize the survival of Ellendale 9.
DS1112-0024
2011
Ahmed, A.H.Arai, S., Ahmed, A.H., Miura, M.Ultrahigh pressure podiform chromitites as a possible deep recycled material.Goldschmidt Conference 2011, abstract p.447.Asia, Tibet, OmanUHP
DS1502-0037
2015
Ahmed, A.H.Ahmed, A.H., Habtoor, A.Heterogeneously depleted Precambrian lithosphere deduced from mantle peridotites and associated chromitite deposits of Al, Ays ophiolite, northwestern Arabian shield, Saudi Arabia.Ore Geology Reviews, Vol. 67, pp. 279-296.Africa, Saudi ArabiaPeridotite

Abstract: The mantle section of Al'Ays ophiolite consists of heterogeneously depleted harzburgites, dunites and large-sized chromitite pods. Two chromitite-bearing sites (Site1 and Site2), about 10 km apart horizontally from one another, were examined for their upper mantle rocks. Cr-spinels from the two sites have different chemistry; Cr-rich in Site1 and Al-rich in Site2. The average Cr-ratio = (Cr/(Cr + Al) atomic ratio) of Cr-spinels in harzburgites, dunites and chromitites is remarkably high 0.78, 0.77 and 0.87, respectively, in Site1, compared with those of Site2 which have intermediate ratio averages 0.5, 0.56 and 0.6, respectively. The platinum-group elements (PGE) in chromitites also show contrasting patterns from Site1 to Site2; having elevated IPGE (Os, Ir, Ru) and strongly depleted in PPGE (Rh, Pt, Pd) with steep negative slopes in the former, and gentle negative slopes in the latter. The oxygen fugacity (?log fO2) values deduced from harzburgites and dunites of Site1 show a wide variation under reducing conditions, mostly below the FMQ buffer. The Site2 harzburgites and dunites, on the other hand are mostly above the FMQ buffer. Two magmatic stages are suggested for the lithospheric evolution of Al'Ays ophiolite in response to a switch of tectonic setting. The first stage produced a peridotites–chromitites suite with Al-rich Cr-spinels, possibly beneath a mid-ocean ridge setting, or most likely in back-arc rift of a supra-subduction zone setting. The second stage involved higher degrees of partial melting, produced a peridotites–chromitites suite with Cr-rich Cr-spinels, possibly in a fore-arc setting. The coexistence of compositionally different mantle suites with different melting histories in a restricted area of an ophiolite complex may be attributable to a mechanically juxtaposed by mantle convection during recycling. The mantle harzburgites and dunites are apt to be compositionally modified during recycling process; being highly depleted (Site1 case) than their original composition (Site2 case).
DS1601-0001
2016
Ahmed, A.H.Ahmed, A.H., Moghazi, A.K.D., Moufti, M.R., Dawood, Y.H., Ali, K.A.Nature of the lithospheric mantle beneath the Arabian shield and genesis of Al-spinel micropods: evidence from the mantle xenoliths of Harrat Kishb, western Saudi Arabia.Lithos, Vol. 240-243, pp. 119-139.Africa, Saudi ArabiaPeridotite

Abstract: The Harrat Kishb area of western Saudi Arabia is part of the Cenozoic volcanic fields in the western margin of the Arabian Shield. Numerous fresh ultramafic xenoliths are entrained in the basanite lava of Harrat Kishb, providing an opportunity to study the nature and petrogenetic processes involved in the evolution of the lithospheric mantle beneath the Arabian Shield. Based on the petrological characteristics and mineralogical compositions, the majority of the mantle xenoliths (~ 92%) are peridotites (lherzolites and pyroxene-bearing harzburgites); the remaining xenoliths (~ 8%) are unusual spinel-rich wehrlites containing black Al-spinel micropods. The two types of mantle xenoliths display magmatic protogranular texture. The peridotite xenoliths have high bulk-rock Mg#, high forsterite (Fo90-Fo92) and NiO (0.24-0.46 wt.%) contents of olivine, high clinopyroxene Mg# (0.91-0.93), variable spinel Cr# (0.10-0.49, atomic ratio), and approximately flat chondrite-normalized REE patterns. These features indicate that the peridotite xenoliths represent residues after variable degrees of melt extraction from fertile mantle. The estimated P (9-16 kbar) and T (877-1227 °C) as well as the oxidation state (?logfO2 = - 3.38 to - 0.22) under which these peridotite xenoliths originated are consistent with formation conditions similar to most sub-arc abyssal-type peridotites worldwide. The spinel-rich wehrlite xenoliths have an unusual amount (~ 30 vol.%) of Al-spinel as peculiar micropods with very minor Cr2O3 content (< 1 wt.%). Olivines of the spinel-rich wehrlites have low-average Fo (Fo81) and NiO (0.18 wt.%) contents, low-average cpx Mg# (0.79), high average cpx Al2O3 content (8.46 wt.%), and very low-average spinel Cr# (0.01). These features characterize early mantle cumulates from a picritic melt fraction produced by low degrees of partial melting of a garnet-bearing mantle source. The relatively high Na2O and Al2O3 contents of cpx suggest that the spinel-rich wehrlites are formed under high P (11-14 kbar), T (1090-1130 °C), and oxidation state (?logfO2 FMQ = + 0.14 to + 0.37), which occurred slightly below the crust-mantle boundary. The REE patterns of spinel-rich wehrlites are almost similar to those of the associated peridotite xenoliths, which confirm at least a spatial genetic linkage between them. Regarding the formation of Al-spinel micropods in spinel-rich wehrlite cumulates, it is suggested that the melt-rock reaction mechanism is not the only process by which podiform chromitite is formed. Early fractionation of picritic melts produced by partial melting of a mantle source under high P-T conditions could be another mechanism. The cpx composition, not opx, as it was assumed, seems to be the main control of the size and composition of spinel concentrations.
DS1990-1289
1990
Ahmed, F.Sadig, A.A., Ahmed, F.Gravity signatures over selected ring complexes in the Sudan, and their tectonic significanceJournal of African Earth Sciences, Vol. 9, No. 3/4, pp. 481-487GlobalGeophysics -gravity, Tectonics
DS0612-0966
2001
Ahmed, M.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
DS2001-0012
2001
Ahmed, M.Ahmed, M., Shivanna, S.Search for kimberlites in the granitic terrain of Gulbarga and Raichur districts, Karnataka.India Geological Survey Records, No. 132, 5, p. 90-91.IndiaNews item - exploration
DS0912-0004
2009
Ahmed, S.Ahmed, S.Value addition in diamonds and other gemstones by nuclear radiation: the phobias and safety considerations.Atoms for Peace: an Internatiohnal Journal, Interscience Publishers Ltd., August 13, Vol. 2, no. 4, pp. 409-418. Ingenta art00008Technologydiamond
DS1312-0520
2013
Ahmed, S.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
DS1611-2121
2016
Ahmed, S.Kaur, G., Mitchell, R.H., Ahmed, S.Typomorphic mineralogy of the Vattikod lamproites from Mesoproterozoic Ramadugu lamproite field, Nalgonda district, Telangana India: a plausible manifestation of subduction related alkaline magmatism in the Eastern Ghats mobile belt?IGC 35th., 1p. AbstractIndiaLamproite

Abstract: Lamproites are mineralogically complex rocks and their bulk rock geochemistry is not for characterization of their parental magmas (Mitchell and Bergman, [1]). Characterization is best accomplished by consideration of their typomorphic mineralogy. We have investigated nine dykes from Vattikod (VL1:Vl8 and VL10). The mineral assemblage and their compositions are comparable to those of lamproites in terms of the presence of phlogopite (Ti-rich, Al-poor phlogopite and tetraferriphlogopite); amphiboles (potassic-arfvedsonite, potassic-richterite, potassic-ferro-richterite, potassic-katophorite, Ti- rich potassic-katophorite, Ti-rich potassic-magnesio-katophorite); Al-poor pyroxene; feldspars (K- feldspar, Ba-K-feldspar and Na-feldspar), spinels (chromite-magnetite and qandilite-ulvÖspinel-ZnFe2O4). These dykes have also undergone varied degrees of deuteric alteration as shown by the development of secondary phases such as titanite, allanite, hydro-zircon, calcite, chlorite, quartz and cryptocrystalline SiO2. We have classified the Vattikod dyke on the basis of their typomorphic major mineralogy in conjunction with alteration affects as: Group 1 (VL1); Group 2 (VL2 and VL3); Group 3 (VL4 and VL5); Group 4 (VL6, VL7 and VL8); and Group 5 (VL10). Group 2 dykes are pseudoleucite-amphibole-lamproite; Group 3 dykes are pseudoleucite-phlogopite-lamproite; Group 4 dykes are pseudoleucite-phlogopite- amphibole-lamproite. The Group 1 dyke is completely altered and the precursor mineralogy cannot be identified. Group 5 dyke is also extensively altered but contains fresh euhedral apatite microphenocrysts together with pseudomorphs after leucite and is classified as a pseudoleucite-apatite-(phlogopite?) lamproite. It is suggested that the Vattikod lamproites represent a spectrum of modal variants of lamproite produced by the differentiation and crystallization of a common parental peralkaline potassic magma. The near-linear disposition of Deformed Alkaline Rocks and Carbonatites commonly known as DARC’s (Burke and Khan, [2]) and lamproites in eastern India implies a relationship with subduction-related processes (Das Sharma & Ramesh, [3]; Gurmeet Kaur & Mitchell, [4]). We propose that the Vattikod and other lamproites in eastern India emplaced at 1100-1450 Ma are possible manifestations of subduction- related alkaline magmatism along the Eastern Ghats Mobile Belt, in contrast to extension-related anorogenic lamproite magmatism related to supercontinent(s) break-up as has been suggested for Ramadugu and other Dharwar Craton lamproites.
DS1805-0954
2018
Ahmed, S.Kaur, G., Mitchell, R.H., Ahmed, S.Mineralogy of the Vattikod lamproite dykes, Ramadugu lamproite field, Nalgonda District, Telangama: a possible expression of ancient subduction related alkaline magmatism along eastern Ghats mobile belt, India.Mineralogical Magazine, Vol. 82, 1, pp. 35-58.Indialamproite

Abstract: The mineralogy of nine recently discovered dykes (VL1:VL8 and VL10) in the vicinity of Vattikod village, Nalgonda district in Telangana State is described. The mineral assemblage present and their compositions are comparable to those of bona fide lamproites in terms of the presence of phlogopite (Ti-rich, Al-poor phlogopite and tetraferriphlogopite); amphiboles (potassic-arfvedsonite, potassic-richterite, potassic-ferro-richterite, potassic-katophorite, Ti-rich potassic-katophorite, Ti-rich potassic-magnesio-katophorite); Al-poor clinopyroxenes; feldspars (K-feldspar, Ba-K-feldspar and Na-feldspar) and spinels (chromite-magnetite and qandilite-ulvöspinel-franklinite). These dykes have undergone diverse and significant degrees of deuteric alteration as shown by the formation of secondary phases such as: titanite, allanite, hydro-zircon, calcite, chlorite, quartz and cryptocrystalline SiO2. On the basis of their respective mineralogy: the VL4 and VL5 dykes are classified as pseudoleucite-phlogopite lamproite; VL2 and VL3 dykes as pseudoleucite-amphibole-lamproite; and VL6, VL7 and VL8 as pseudoleucite-phlogopite-amphibole-lamproite. VL10 is extensively altered but contains fresh euhedral apatite microphenocrysts together with pseudomorphs after leucite and is classified as a pseudoleucite-apatite-(phlogopite?) lamproite. The mineralogy of the Vattikod lamproite dykes is compared with that of the Ramadugu, Somavarigudem and Yacharam lamproite dykes which also occur in the Ramadugu lamproite field. The lamproites from the Eastern Dharwar Craton are considered as being possible expressions of ancient subduction-related alkaline magmatism along the Eastern Ghats mobile belt.
DS1991-0005
1991
Ahmed, Z.Ahmed, Z., McCormick, G.R.A newly discovered kimberlitic rock from PakistanMineralogical Magazine, Vol. 54, December pp. 537-546PakistanKimberlite, Mineral chemistry
DS1996-0011
1996
Ahmed Benan, C.Ahmed Benan, C., Deynoux, M.Facies association and sequence stratigraphy on an upper Proterozoic cratonic platform: Aldar ..C.r. Academy Of Science, Vol. 322, iia, pp. 625-32.GlobalCraton, Stratigraphy
DS1995-0012
1995
Ahmed Zid, I.Ahmed Zid, I.A kimberlitic lamprophyre and associated alkalic basaltic rocks from Pishlin District, Pakistan.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 4.PakistanSpangar Garkai, Kozh Kach areas, Alkaline rocks
DS1995-0013
1995
Ahmed Zid, I.Ahmed Zid, I., Madon, M.Electron microscopy of high pressure phases synthesized from natural garnets in a diamond anvil cell: mantle.Earth and Planetary Science Letters, Vol. 129, No. 1-4, January pp. 233-248.MantleGarnet mineralogy, Petrology -experimental
DS2002-0012
2002
Ahmedov, A.Ahmedov, A., Panova, E., Krupenik, V., Svehnikova, K.Diamond from Early Proterozoic and Devonian rocks of the joint zone of the Baltic Shield and Russian platform.18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.272.Russia, Baltic ShieldLithogenesis - sedimentary basins
DS0412-0319
2003
AhnChen, J.F., Xie, Z., Li, H.M., Zhang, X.D., Zhou, T.X., Park, Ahn, Chen, ZhangU Pb zircon ages for a collision related K rich complex at Shidao in the Sulu ultrahigh pressure terrane, China.Geochemical Journal, Vol. 37, pp. 35-46.ChinaUHP, shoshonites
DS2003-0248
2003
AhnChen, J.F., Xie, Z., Li, H.M., Zhang, X.D., Zhou, T.X., Park, Ahn, Chen, ZhangU Pb zircon ages for a collision related K rich complex at Shidao in the Sulu ultrahighGeochemical Journal, Vol. 37, pp. 35-46.ChinaBlank
DS1950-0139
1953
Ahrens, L.H.Holyk, W., Ahrens, L.H.Potassium in Ultramafic RocksGeochim Et Cosmochim. Acta., Vol. 4, PP. 241-250.South AfricaPetrology
DS1960-0675
1966
Ahrens, L.H.Gurney, J.J., Berg, G.W., Ahrens, L.H.Observations on Caesium Enrichment and the Potassium Rubidium Caesium Relationship in Eclogites from the Roberts Victormine.Nature., Vol. 210, PP. 1025-1027.South AfricaGeochronology, Mineralogy
DS1960-0773
1967
Ahrens, L.H.Ahrens, L.H., Cherry, R.D., Erlank, A.J.Observations on the Th-u Relationship in Zircons from Granitic Rocks and from Kimberlites.Geochim. Et. Cosmochim. Acta., Vol. 31, PP. 2379-2387.South AfricaUranium, Thorium, Mineral Chemistry
DS1970-0699
1973
Ahrens, L.H.Gurney, J.J., Ahrens, L.H.The Zinc Content of Some Ultramafic and Basic RocksGeological Society of South Africa Transactions, Vol. 76, No. 3, PP. 301-307.South AfricaMineralogy
DS1975-0002
1975
Ahrens, L.H.Ahrens, L.H., Dawson, J.B., Duncan, A.R., Erlank, A.J.First International Conference on Kimberlites Held in Cape Town from 24th to 28th September 1973.Physics And Chemistry of The Earth, New York: Pergamon Press, Vol. 9, 936P.GlobalKimberlite, Kimberley, Janlib
DS1975-1169
1979
Ahrens, L.H.Nyambok, I.O., Ahrens, L.H.Geochemistry of the Carbonatite Complexes in East AfricaPhysics and Chemistry of the Earth., Vol. 11, PP. 533-539.East Africa, UgandaLeucitite, Leucite, Genesis, Related Rocks
DS1983-0003
1983
Ahrens, L.H.Ahrens, L.H.New Minerals from the Upper MantleGeological Society of South Africa Quarterly NEWS Bulletin., Vol. 27, No. 3, SEPTEMBER PP. 13-14.South Africa, Kimberley AreaMineralogy
DS0412-0012
2004
Ahrens, T.J.Akins, J.A., Luo, S.N., Asimow, P.D., Ahrens, T.J.Shock induced melting of MgSiO3 perovskite and implications for melts in Earth's lowermost mantle.Geophysical Research Letters, Vol. 31, 14, DOI 10.1029/2004 GLO20237MantleMelt
DS0412-0068
2004
Ahrens, T.J.Asimow, P.D., Sun, D., Akins, J.A., Luo, S.N., Ahrens, T.J.Petrology of the lowermost mantle.Geochimica et Cosmochimica Acta, 13th Goldschmidt Conference held Copenhagen Denmark, Vol. 68, 11 Supp. July, ABSTRACT p.A561.MantleGeophysics - seismics
DS0912-0519
2009
Ahrens, T.J.Mosenfelder, J.L., Asimow, P.D., Frost, D.J., Rubie, D.C., Ahrens, T.J.The MgSiO3 system at high pressure: thermodynamic properties of perovskite, postperovskite and melt from global inversion of shock and static compression data.Journal of Geophysical Research, Vol. 114, B1 B01203.MantlePerovskite
DS1983-0361
1983
Ahrens, T.J.Kondo, K., Ahrens, T.J.Shock Impression of Diamond CrystalGeophysical Research Letters, Vol. 10, No. 4, PP. 181-184.GlobalGenesis, Formation
DS1989-0012
1989
Ahrens, T.J.Ahrens, T.J.Water storage in the mantleNature, Vol. 342, November 9, pp. 122-123GlobalMantle, Genesis, Origin
DS1990-0907
1990
Ahrens, T.J.Lay, T., Ahrens, T.J., Olson, P., Smyth, J., Loper, D.Studies of the earth's deep interior: goals and trendsPhysics Today, Vol. 43, No. 10, October pp. 44-52GlobalDynamic earth system, Mantle
DS1997-0514
1997
Ahrens, T.J.Holland, K.G., Ahrens, T.J.Melting of (magnesium, iron)(magnesium, iron)2 SiO4 at the core-mantle boundary of the earth.Science, Vol. 275, No. 5306, Mar. 14, pp. 1623-25.MantleMelting, Core-mantle boundary
DS2002-0972
2002
Ahrens, T.J.Luo, S.N., Mosenfelder, J.L., Asimow, P.D., Ahrens, T.J.Direct shock wave loading of stishovite to 235 GPa: implications for perovskite stabilityGeophysical Research Letters, Vol. 29, 14, July 15, p. 36-MantleMineralogy
DS1975-0440
1977
Ahuja, H.S.Ahuja, H.S.Kimberlites: a ReviewMsc. Thesis, Northeastern Illinois University, Chicago, GlobalKimberlite, Genesis, Occurrences, Classification
DS0412-0132
2003
Ahuja, k R.Belonoshko, A.B., Ahuja,k R., Johannson, B.Stability of the body centered cubic phase of iron in the Earth's inner core.Nature, No. 6952, August 28, pp. 1032-4.MantleGeochemistry
DS2003-0097
2003
Ahuja, k R.Belonoshko, A.B., Ahuja,k R., Johannson, B.Stability of the body centered cubic phase of iron in the Earth's inner coreNature, No. 6952, August 28, pp. 1032-4.MantleGeochemistry
DS0512-1002
2005
Ahuja, R.Skorodumova, N.V., Belonoshko, A.B., Huang, L., Ahuja, R., Johansson, B.Stability of the MgCO3 structures under lower mantle conditions.American Mineralogist, Vol.90, pp. 1008-1011.MantleCarbon, Liquid outer core, boundary
DS0612-1485
2006
Ahuja, R.Vitos, L., Magyati-Kope, B., Ahuja, R., Kollar, J., Grimvall, G., Johansson, B.Phase transformations between garnet and perovskite phases in the Earth's mantle: a theoretical study.Physics of the Earth and Planetary Interiors, Vol. 156, 1-2, pp. 108-116.MantleLower mantle, majorite, geophysics -seismic
DS0712-0468
2007
Ahuja, R.Isaev, E.I., Skorodumova, N.V., Ahuja, R., Vekilov, Y.K., Johansson, B.Dynamical stability of Fe-H in the Earth's mantle and core regions.Proceedings of National Academy of Sciences USA, Vol. 104, 22, pp. 9168-9177. IngentaMantleChemistry
DS0812-0337
2008
Ahuja, R.Fang, C., Ahuja, R.Local structure and electronic spin transition of Fe bearing MgSiO3 perovskite under conditions of the Earth's lower mantle.Physics of the Earth and Planetary Interiors., Vol. 166, 1-2, pp. 77-82.MantleMineral chemistry
DS1312-1008
2013
AiZeng, X-Q., Zheng, Y-L., Yang, Z-J., Ai, Hu, Q.Study on the micro-FTIR and raman spectra of the alluvial diamonds from Yangtze craton and their geological significance.Spectroscopy and Spectral Analysis, Vol. 33, no. 10.pp. 2694-2699.ChinaAlluvials
DS0512-0664
2005
Ai, X.Ma, C., She, Z., Ai, X.An Early Cretaceous intrusive complex in the Dabie Shan ultrahigh pressure metamorphic terrane, East China. Evidence for the beginning of post orogenic collapse.GAC Annual Meeting Halifax May 15-19, Abstract 1p.ChinaUHP, crustal root
DS0412-0008
2003
Ai, Y.Ai, Y., Zheng, T.The upper mantle discontinuity structure beneath eastern China.Geophysical Research Letters, Vol. 30, 21, Nov. 1, 10.1029/2003 GLO17678ChinaGeophysics - seismics
DS0412-0009
2003
Ai, Y.Ai, Y., Zheng, T., Xu, W., He, Y., Dong, D.A complex 660 km discontinuity beneath northeast China.Earth and Planetary Science Letters, Vol. 212, 1-2, pp. 63-71.ChinaGeophysics - seismics Tectonics
DS0512-1244
2005
Ai, Y.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
DS0712-0005
2007
Ai, Y.Ai,Y., Chen, Q-F., Zeng, F., Hong, X., Ye, W.The crust and upper mantle structure beneath southeastern China.Earth and Planetary Science Letters, Vol. 260, 3-4, pp. 549-563.ChinaTectonics
DS1212-0827
2012
Ai, Y.Zheng, T., Zhu, R., Liang, Ai, Y.Intralithospheric mantle structures recorded continental subduction.Journal of Geophysical Research, Vol. 117, B3, B03308MantleSubduction
DS1508-0370
2015
Ai, Y.O'Leary, M.C., Lange, R.A., Ai, Y.The compressability of CaCO3-Li2CO3-Na2CO3-K2CO3 liquids: application to natrocarbonatite and CO2- bearing nephelinite liquids from Oldoinyo Lengai.Contributions to Mineralogy and Petrology, Vol. 170, 18p.Africa, TanzaniaDeposit - Oldoinyo Lengai
DS2003-0003
2003
Ai, Y.Ai, Y., Zheng, T.The upper mantle discontinuity structure beneath eastern ChinaGeophysical Research Letters, Vol. 30, 21, 2089 DOI.1029/2003GLO17678eastern ChinaGeophysics - seismics
DS2003-0004
2003
Ai, Y.Ai, Y., Zheng, T., Xu, W., He, Y., Dong, D.A complex 660 km discontinuity beneath northeast ChinaEarth and Planetary Science Letters, Vol. 212, 1-2, pp. 63-71.ChinaTectonics
DS1810-2304
2018
Aibai, A.Cheng, Z., Zhang, Z., Aibai, A., Kong, W., Holtz, F.The role of magmatic and post-magmatic hydrothermal processes on rare earth element mineralization: a study of the Bachu carbonatites from the Tarim Large Igneous Province, NW China.Lithos, Vol. 314-315, pp. 71-87.Chinacarbonatite

Abstract: The contribution of magmatic and hydrothermal processes to rare earth element (REE) mineralization of carbonatites remains an area of considerable interest. With the aim of better understanding REE mineralization mechanisms, we conducted a detailed study on the petrology, mineralogy and C-O isotopes of the Bachu carbonatites, NW China. The Bachu carbonatites are composed predominantly of magnesiocarbonatite with minor calciocarbonatite. The two types of carbonatite have primarily holocrystalline textures dominated by dolomite and calcite, respectively. Monazite-(Ce) and bastnäsite-(Ce), the major REE minerals, occur as euhedral grains and interstitial phases in the carbonatites. Melt inclusions in the dolomite partially rehomogenize at temperatures above 800?°C, and those in apatite have homogenization temperatures (Th) ranging from 645 to 785?°C. Oxygen isotope ratios of the calciocarbonatite intrusions (d18OV-SMOW?=?6.4‰ to 8.3‰), similar to the magnesiocarbonatites, indicate the parental magma is mantle-derived, and that they may derive from a more evolved stage of carbonatite fractionation. The magnesiocarbonatites are slightly enriched in LREE whereas calciocarbonatites have higher HREE concentrations. Both dolomite and calcite have low total REE (TREE) contents ranging from 112 to 436?ppm and 88 to 336?ppm, respectively, much lower than the bulk rock composition of the carbonatites (371 to 36,965?ppm). Hence, the fractional crystallization of carbonates is expected to elevate REE concentrations in the residual magma. Rocks from the Bachu deposit with the highest TREE concentration (up to 20?wt%) occur as small size (2?mm to 3 cm) red rare earth-rich veins (RRV) with barite + celestine + fluorapatite + monazite-(Ce) associations. These rocks are interpreted to have a hydrothermal origin, confirmed by the fluid inclusions in barite with Th in the range 198-267?°C. Hydrothermal processes may also explain the existence of interstitial textures in the carbonatites with similar mineral assemblages. The C-O isotopic compositions of the RRV (d13CV-PDB?=?-3.6 to -4.3‰, d18OV-SMOW?=?7.6 to 9.8‰) are consistent with an origin resulting from fluid exsolution at the end of the high temperature fractionation trend. A two-stage model involving fractional crystallization and hydrothermal fluids is proposed for the mineralization of the Bachu REE deposit.
DS2002-0939
2002
AibingLi, Aibing, Fischer, K.M., Van der Lee, S., Wysession, M.Crust and upper mantle discontinuity structure beneath eastern North AmericaJournal of Geophysical Research, Vol.107,5, May 28, 10.1029/2002JB001891AppalachiaCore - mantle boundary, Geophysics - seismics
DS1950-0443
1959
Aicard, P.Aicard, P.Application des Methodes Geochimiques (chromium et Nickel) a la Recherche de Pipes Kimberlitique: Relutats Obtenus sur un Pipe Deja Connu (kenieba) Soudan Francais.Annual Mines, PARIS, No. 2, PP. 1-3=106.West Africa, French Equatorial AfricaSekonomata, Geochemistry
DS0412-1109
2004
Aifa, T.LeFort, J.P., Aifa, T., Bourrouilh, R.Paleomagnetic and paleontologic evidence for an antipodal position of the West African Craton and of norther Chin a in Rodinia puComptes Rendus Geoscience, Vol. 336, 2, Feb. pp. 159-165.ChinaGeophysics - magnetism
DS2002-0931
2002
Aifa, T.Lefort, J.P., Aifa, T.Evidence for circum terrestrial loop of the Apwp of the west African Craton between 2.2 ad 0.9 Ga: its temporary amalgamation to Columbia and Rodinia.11th. Quadrennial Iagod Symposium And Geocongress 2002 Held Windhoek, Abstract p. 32.Africa, Gondwana, RodiniaGeochronology, Reguibat Uplift
DS1984-0450
1984
Aikem, C.L.V.Leonhardt, F.H., Aikem, C.L.V.Gravity Study of Some Shallow and Deep Structures in the Ouachita Tectonic Belt, Oklahoma.Geophysics, Vol. 49, No. 5, MAY P. 618. (abstract.).OklahomaMid-continent
DS0512-0434
2005
Aiken, C.Hinze, W.J., Aiken, C., Brozena, J., Coakley, Dater, Flanagan, Forsberg, Hildenbrand, Keller, KelloggNew standards for reducing gravity data: the North American gravity database.Geophysics, Vol. 70, 4, pp. J25-J32.Canada, United StatesGeophysics - gravity
DS1982-0320
1982
Aiken, C.L.V.Keller, G.R., Kruger, J.M., Schneider, R.V., Aiken, C.L.V., Lai.Regional Geophysical Studies of the Southern Oklahoma Aulocogen and Ouachita SystemGeological Society of America (GSA), Vol. 14, No. 3, P. 115, (abstract.).OklahomaMid-continent, Geophysics
DS1983-0349
1983
Aiken, C.L.V.Keller, G.R., Coultrip, R.L., Peeples, W.J., Aiken, C.L.V.A Regional Gravity Study of the Colorado Plateau and Adjacent Regions.Geological Society of America (GSA), Vol. 15, No. 5, P. 317. (abstract.).Colorado, Rocky Mountains, Colorado Plateau, Arizona, New MexicoMid-continent
DS1991-0006
1991
Aiken, J.D.Aiken, J.D.Two late Proterozoic glaciations, Mackenzie Mountains, northwesternCanadaGeology, Vol. 19, No. 5, May pp. 445-448Northwest TerritoriesGeomorphology, Glaciation
DS1606-1078
2016
Aileres, L.Betts, P.G., Armit, R.J., Stewart, J., Aitken, A.R.A., Aileres, L., Donchak, P., Hutton, L., Withnall, I., Giles, D.Australia and Nuna.Geological Society of London Special Publication Supercontinent Cycles through Earth History., Vol. 424, pp. 47-81.AustraliaSupercontinents

Abstract: The Australian continent records c. 1860-1800 Ma orogenesis associated with rapid accretion of several ribbon micro-continents along the southern and eastern margins of the proto-North Australian Craton during Nuna assembly. The boundaries of these accreted micro-continents are imaged in crustal-scale seismic reflection data, and regional gravity and aeromagnetic datasets. Continental growth (c. 1860-1850 Ma) along the southern margin of the proto-North Australian Craton is recorded by the accretion of a micro-continent that included the Aileron Terrane (northern Arunta Inlier) and the Gawler Craton. Eastward growth of the North Australian Craton occurred during the accretion of the Numil Terrane and the Abingdon Seismic Province, which forms part of a broader zone of collision between the northwestern margins of Laurentia and the proto-North Australian Craton. The Tickalara Arc initially accreted with the Kimberley Craton at c. 1850 Ma and together these collided with the proto-North Australian Craton at c. 1820 Ma. Collision between the West Australian Craton and the proto-North Australian Craton at c. 1790-1760 Ma terminated the rapid growth of the Australian continent.
DS0912-0591
2009
Ailleres, L.Porritt, L.A., Cas, R.A., Ailleres, L., Oshust, P.The influence of volcanological and sedimentalogical processes on diamond distribution: example from the Ekati diamond mine, NWT Canada.GAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyCanada, Northwest TerritoriesDeposit - Ekati
DS1212-0567
2012
Ailleres, L.Porritt, L.A., Cas, R.A.F., Ailleres, L., Oshust, P.The influence of volcanological and sedimentaological processes on diamond grade distribution in kimberlites: examples from the Ekati diamond mine, NWT, Canada.Bulletin of Volcanology, Vol. 73, 8, pp. 1085-1105.Canada, Northwest TerritoriesDiamond grade
DS1412-0056
2014
Ailleres, L.Blaikie, T.N., Ailleres, L., Betts, P.G., Cas, R.A.F.A geophysical comparison of the diatremes of simple and complex maar volcanoes, Newer Volcanics Province, south-eastern Australia.Journal of Volcanology and Geothermal Research, Vol. 276, pp. 64-81.AustraliaVolcanoes
DS1412-0057
2014
Ailleres, L.Blaikie, T.N., Ailleres, L., Betts, P.G., Cas, R.A.F.A geophysical comparison of the diatremes of simple and complex Maar volcanoes, Newer Volcanic Province, south-eastern Australia.Journal of Volcanology and Geothermal Research, Vol. 276, pp. 64-81.AustraliaGeophysics - volcanoes
DS1504-0185
2015
Ailleres, L.Block, S., Ganne, J., Baratoux, A.Z., Parra-Avila, L.A., Jessell, M., Ailleres, L., Siebenaller, L.Petrological and geochronological constraints on lower crust exhumation during Paleoproterozoic (Eburnean) Orogeny, NW Ghana, West African craton.Journal of Metamorphic Geology, Vol. 33, 5, pp. 463-494.Africa, GhanaGeochronology

Abstract: New petrological and geochronological data are presented on high-grade ortho- and paragneisses from northwestern Ghana, forming part of the Paleoproterozoic (2.25-2.00 Ga) West African Craton. The study area is located in the interference zone between N-S and NE--SW-trending craton-scale shear zones, formed during the Eburnean orogeny (2.15-2.00 Ga). High-grade metamorphic domains are separated from low-grade greenstone belts by high-strain zones, including early thrusts, extensional detachments and late-stage strike-slip shear zones. Paragneisses sporadically preserve high-pressure, low-temperature (HP-LT) relicts, formed at the transition between the blueschist facies and the epidote-amphibolite sub-facies (10.0-14.0 kbar, 520-600 °C), and represent a low (~15 °C km-1) apparent geothermal gradient. Migmatites record metamorphic conditions at the amphibolite-granulite facies transition. They reveal a clockwise pressure-temperature-time (P-T-t) path characterized by melting at pressures over 10.0 kbar, followed by decompression and heating to peak temperatures of 750 °C at 5.0-8.0 kbar, which fit a 30 °C km-1 apparent geotherm. A regional amphibolite facies metamorphic overprint is recorded by rocks that followed a clockwise P-T-t path, characterized by peak metamorphic conditions of 7.0-10.0 kbar at 550-680 °C, which match a 20-25 °C km-1 apparent geotherm. These P-T conditions were reached after prograde burial and heating for some rock units, and after decompression and heating for others. The timing of anatexis and of the amphibolite facies metamorphic overprint is constrained by in-situ U-Pb dating of monazite crystallization at 2138 ± 7 and 2130 ± 7 Ma respectively. The new data set challenges the interpretation that metamorphic breaks in the West African Craton are due to diachronous Birimian ‘basins’ overlying a gneissic basement. It suggests that the lower crust was exhumed along reverse, normal and transcurrent shear zones and juxtaposed against shallow crustal slices during the Eburnean orogeny. The craton in NW Ghana is made of distinct fragments with contrasting tectono-metamorphic histories. The range of metamorphic conditions and the sharp lateral metamorphic gradients are inconsistent with ‘hot orogeny’ models proposed for many Precambrian provinces. These findings shed new light on the geodynamic setting of craton assembly and stabilization in the Paleoproterozoic. It is suggested that the metamorphic record of the West African Craton is characteristic of Paleoproterozoic plate tectonics and illustrates a transition between Archean and Phanerozoic orogens.
DS1991-0007
1991
Aina, A.Aina, A., Emofurieta, W.O.VLF anomalies at contacts between Precambrian rocks in southwest NigeriaGeoexploration, Vol. 28, No. 1, April, pp. 55-66NigeriaGeophysics -VLF., Precambrian
DS1991-0008
1991
Aina, A.Aina, A., Emofurieta, W.O.The use of very low frequency electromagnetic method for non-conductive resource evaluation and geological mappingJournal of African Earth Sciences, Vol. 12, No. 4, pp. 609-616NigeriaGeophysics, Electromagnetics -mapping
DS1992-0010
1992
Aina, A.Aina, A., Olarewaju, V.O.Geological interpretation of aeromagnetic dat a in some parts of North central NigeriaJournal of Africam Earth Sciences, Vol. 14, No. 1, pp. 103-109NigeriaGeophysics, Granite ring complexes
DS0412-1485
2003
Ainbinder, H.Ovcharenko, O.V., Ainbinder, H., Shilin, K.Y., Kramskov, N.P.Geomechanical substantiation of the parameters for underground mining of Mir kimberlite pipe.Journal of Mining Science, Vol. 38, 6, pp. 528-33.Russia, Siberia, YakutiaMining Deposit - Mir
DS2003-1038
2003
Ainbinder, H.Ovcharenko, O.V., Ainbinder, H., Shilin, K.Y., Kramskov, N.P.Geomechanical substantiation of the parameters for underground mining of MirJournal of Mining Science, ( Kluwer Academic), Vol. 38, 6, pp. 528-33.Russia, Siberia, YakutiaMining, Deposit - Mir
DS1012-0800
2009
Ainbinder, L.L.Trubetskoy, K.N., Galchenko, Y.P., Ainbinder, L.L., Sabinyan, G.V.Outlook for the enhanced safety and improved efficiency of diamond deposit mining.Journal of Mining Science, Vol. 45, 6, pp. 581-590.RussiaMining - Yakutia pipes
DS1989-0013
1989
Ainemer, A.I.Ainemer, A.I.Placer forming barriersMarine Mining, Vol. 8, pp. 281-291GlobalPlacers, Classifications
DS1989-0014
1989
Ainemer, A.I.Ainemer, A.I.Placer forming barriersMarine Mining, Vol. 8, pp. 283-91.GlobalPlacers, alluvials, Geomorphology - not specific to diamonds - mentions
DS1984-0003
1984
Aines, R.Aines, R., Rossman, G.R.Water Content of Mantle GarnetsGeology, Vol. 12, Dec. pp. 720-23.Colorado PlateauGarnet Megacrysts, Green Knobs, Garnet Ridge
DS1982-0002
1982
Aines, R.D.Aines, R.D., Rossman, G.R.The Hydrous Component in GarnetsGeological Society of America (GSA), Vol. 14, No. 7, P. 430, (abstract.).Colorado Plateau, South Africa, United States, Rocky MountainsMineralogy
DS0412-1817
2003
Aiqun, S.Shuyin, N., Quanlin, H., Zengqian, H., Aiqun, S., Baode, W., Hongyang, L., Chuanshi, X.Cascaded evolution of mantle plumes and metallogenesis of core and mantle derived elements.Acta Geologica Sinica, Vol. 77, 4, pp. 522-536.MantleMetallogeny
DS1988-0681
1988
Aires, J.R.Szatmari, P., Aires, J.R.Physical modelling of early Cretaceous continental breakup between South America and Africa.(in Portugese).Revista Brasileira de Geociencias, (in Portugese)., Vol. 18, No. 3, September p. 313. (abstract.)BrazilTectonics
DS1809-1988
2015
Airo, M.L.Airo, M.L.Geophysical signatures of mineral deposit types ( mentions diamonds).Finland Geological Survey, http://tupa.gtk.fi /julkaisu/ specialpaper/ sp_058.pdfFinlandgeophysics

Abstract: In this Special Paper volume, the review of physical properties of ore deposit types or mineralization styles is mainly based on published information, in particular on the key note speeches and presentations that were given at two geosciences conferences: Exploration07 held in Toronto in 2007 (proceedings by Milkereit (ed.) 2007), and the SGA meeting held in Uppsala in 2013 (proceedings by Johnsson et al. (eds.) 2013). Diamonds referred to on p. 13.
DS0812-0334
2008
AitAyad, N.Ezzouhari, H., Ribeiro, M.L., AitAyad, N., Moreira, M.E., Charif, A., Ramos, J.M.F., De Oliveira, D.P.S., Coke, C.The magmatic evolution at the Moroccan outboard of the West African Craton between the Late Neoproterozoic and the Early Palaeozoic.Special Publication - Geological Society of London, No. 297, pp. 329-344.Africa, MoroccoMagmatism
DS1994-0030
1994
Aitcheson, S.J.Aitcheson, S.J., Forrest, A.H.Quantification of crustal contamination in open magmatic systemsJournal of Petrology, Vol. 35, No. 2, April pp. 461-488GlobalMagmatism, Crustal contamination
DS1995-0014
1995
Aitcheson, S.J.Aitcheson, S.J., et al.lead isotopes define basement domains of the Altiplano central AndesGeology, Vol. 23, No. 6, June pp. 555-8.Argentina, Peru, Bolivia, ChileGeophysics - gravity
DS1995-0015
1995
Aitcheson, S.J.Aitcheson, S.J., Harmon, R.S., et al.lead isotopes define basement domains of the Altiplano central AndesGeology, Vol. 23, No. 6, June pp. 555-558Peru, Chile, Argentina, AndesGeochronology, Altiplano -Puna Plateau
DS0412-1212
2004
Aitchison, J.C.Malpas, J., Fletcher, C.J.N., Aitchison, J.C.Aspects of the tectonic evolution of China.Geological Society of London Special Paper, No. 226, 368p. $140.ChinaBook - tectonics
DS0512-0011
2005
Aitchison, J.C.Ali, J.R., Aitchison, J.C.Greater India. 80 year old concept in plate tectonic models of India-Asia collision system.Earth Science Reviews, Vol. 72, 3-4, pp. 169-188.IndiaTectonics, Gondwana, paleogeography
DS0512-0680
2004
Aitchison, J.C.Malpas, J., Fletcher, C.J.N., Ali, J.R., Aitchison, J.C.Aspects of the tectonic evolution of China.Geological Society of London , Special Publication 226, 368p. $134.ChinaBook - tectonics
DS0612-0013
2005
Aitchison, J.C.Ali, J.R., Aitchison, J.C.Greater India.Earth Science Reviews, Vol. 72, 3-4, pp. 169-188.IndiaTectonics
DS0912-0106
2009
Aitchison, J.C.Chan, G.H.N., Waters, D.J., Searle, M.P., Aitchison, J.C., Horstwood, M.S.A., Crowley, Q., Lo, C.H., Chan J.Probing the basement of southern Tibet: evidence from crustal xenoliths entrained in a Miocene ultrapotassic dyke.Journal of the Geological Society, Vol. 166, 1, pp. 45-52.Asia, TibetAlkalic
DS1995-0016
1995
Aitchison, J.C.Aitchison, J.C., Flood, P.G.Gamilaroi Terrane: a Devonian rifted intra-oceanic island arc assemblage, New South Wales Australiavolcanism Assoc. Extensional...Geological Society of London Sp, No. 81, pp. 155-168AustraliaNew England Orogen, Tectonics
DS1997-0195
1997
Aitchison, J.C.Clarke, G.L., Aitchison, J.C., Cluzel, D.Eclogites and blueschists of the Pam Peninsula, northeast New Caledonia: areappraisalJournal of Petrology, Vol. 38, No. 7, July pp. 843-876New CaledoniaMagma
DS1112-0086
2011
Aitken, A.Betts, P.G., Giles, D., Aitken, A.Paleoproterozoic accretion processes of Australia and comparisons with Laurentia.International Geology Review, Vol. 53, no. 11-12, pp. 1357-1376.Australia, CanadaTectonics
DS1610-1884
2016
Aitken, A.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
DS0812-0009
2008
Aitken, A.R.A.Aitken, A.R.A., Betts, P.G.High resolution aeromagnetic dat a over central Australia assist Grenville era 1300-11 Ma Rodinia reconstructions.Geophysical Research Letters, Vol. 35, 1, L01306-400.Gondwana, RodiniaGeophysics - magnetics
DS1312-0012
2013
Aitken, A.R.A.Aitken, A.R.A., Raimondo, T., Capitano, F.A.The intraplate character of supercontinent tectonics.Gondwana Research, Vol. 24, 3-4, pp. 807-814.AfricaGeodynamics
DS1606-1078
2016
Aitken, A.R.A.Betts, P.G., Armit, R.J., Stewart, J., Aitken, A.R.A., Aileres, L., Donchak, P., Hutton, L., Withnall, I., Giles, D.Australia and Nuna.Geological Society of London Special Publication Supercontinent Cycles through Earth History., Vol. 424, pp. 47-81.AustraliaSupercontinents

Abstract: The Australian continent records c. 1860-1800 Ma orogenesis associated with rapid accretion of several ribbon micro-continents along the southern and eastern margins of the proto-North Australian Craton during Nuna assembly. The boundaries of these accreted micro-continents are imaged in crustal-scale seismic reflection data, and regional gravity and aeromagnetic datasets. Continental growth (c. 1860-1850 Ma) along the southern margin of the proto-North Australian Craton is recorded by the accretion of a micro-continent that included the Aileron Terrane (northern Arunta Inlier) and the Gawler Craton. Eastward growth of the North Australian Craton occurred during the accretion of the Numil Terrane and the Abingdon Seismic Province, which forms part of a broader zone of collision between the northwestern margins of Laurentia and the proto-North Australian Craton. The Tickalara Arc initially accreted with the Kimberley Craton at c. 1850 Ma and together these collided with the proto-North Australian Craton at c. 1820 Ma. Collision between the West Australian Craton and the proto-North Australian Craton at c. 1790-1760 Ma terminated the rapid growth of the Australian continent.
DS1989-0015
1989
Aitken, J.D.Aitken, J.D.Uppermost Proterozoic Formations in central Mackenzie Mountains, NorthwestTerritoriesGeological Survey of Canada Bulletin, No. 368, 27p. Database # 17639Northwest TerritoriesProterozoic, Geology
DS1993-1543
1993
Aitken, J.D.Stott, D.F., Cook, G.G., Aitken, J.D.Sedimentary cover of the craton: CanadaGeological Society of America DNAG Volume, GNC-D1, 826p. approx. $ 115.00CanadaBook -table of contents, Craton -sedimentary cover
DS1993-1544
1993
Aitken, J.D.Stott, D.F., Cook, G.G., Aitken, J.D.Sedimentary cover of the craton: CanadaGeological Society of America, DNAG Volumes, GNC-D1, 826p. ISBN 0-660-13133-1 $ 115.00 United StatesCanadaWestern Basin, stratigraphy, industrials, Hudson Platform, tectonics
DS1900-0001
1900
Aitton, D.Aitton, D.Eene Bladzijde Uit de Geschiedenis Van den O.v.sDordrecht: Corns. Morks, 14P.Africa, South AfricaHistory
DS0612-0005
2006
Aizawa, Y.Aizawa, Y., Yoneda, A.P V T equation of state of MgSiO3 perovskite and MgO periclase: implications for lower mantle composition.Physics of the Earth and Planetary Interiors, Vol. 155, 1-2, pp. 87-95.MantleGeophysics - seismics, model
DS1988-0324
1988
Ajai KumarJain, Ajai Kumar, Tapi, R.D.Study of carbonatite in the northeast of BarwahDistrict, Khargone, SOURCE[ Vijana Parshad Anusandhan Patrike, (Ind)Vijana Parshad Anusandhan Patrike, (Ind), Vol. 31, No. 2-3, June pp. 89-96IndiaCarbonatite
DS1975-1253
1979
Ajakaiye, D.E.Verheijen, P.J.T., Ajakaiye, D.E.Geophysical Anomalies Over a Pipe Suspectedly Kimberlite In the Precambrian Metamorphic Schist Belt of Northern Nigeria.Geoexploration., Vol. 17, PP. 293-303.GlobalKimberlite, Geophysics, Groundmag
DS1987-0549
1987
Ajakaiye, D.E.Onugba, A., Ajakaiye, D.E.Resistivity and seismic refraction survey of the Masari-KafurKimberlite pipe in NigeriaExploration 87, Technical abstract volume, held Toronto, Sept. 27-Oct., p. 52 abstract onlyNigeriaGeophysics
DS1989-1153
1989
Ajakaiye, D.E.Onugba, A., Bello, A., Ajakaiye, D.E.Resistivity and seismic refraction survey of the Masari/Kafur Kimberlite pipe in northern Nigeria ( and its groundwater reserves)Journal of African Earth Sciences, Vol. 9, No. 2, pp. 235-243NigeriaGeophysics, Seismics
DS1986-0391
1986
Ajarzo, J.MAjarzo, J.MThe argyle diamond mine (1986)The Syrian Journal of Geology, Vol. 11-12, pp. 17-22AustraliaBlank
DS1996-0072
1996
Ajayan, P.M.Banhart, T., Ajayan, P.M.Carbon onion as nanoscopic pressure cells for diamond formationNature, Vol. 382, No. 6590, Aug. 1, pp. 433-435.GlobalDiamond genesis, Diamond morphology
DS0412-0010
2003
Ajit, T.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
DS2003-0005
2003
Ajit, T.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
DS1112-0649
2011
Aka, F.T.Marzoli, A., Aka, F.T., Chiaradia, M., Reisberg, L., Merle, R.Origin of Cameroon Line basanites from metasomatized lithosphere.Goldschmidt Conference 2011, abstract p.1420.Africa, CameroonCongo craton keel
DS0712-0502
2007
Akagi, T.Kagi, H., Sato, S., Akagi, T., Kanda, H.Generation history of carbonado inferred from photoluminescence spectra, cathodluminesence imaging, and carbon isotope composition.American Mineralogist, Vol. 91, 1, pp. 217-224.Africa, Central African RepublicCarbonado, radiation damage
DS1988-0004
1988
Akagi, T.Akagi, T., Masuda, A.Isotopic and elemental evidence for a relationship between kimberlite and Zaire cubic diamondsNature, Vol. 336, No. 6200, Dec. 15, pp. 665-667Democratic Republic of CongoDiamond morphology
DS1988-0444
1988
Akagi, T.Masuda, A., Akagi, T.The cause of misleading K-Ar ages of diamonds, actually young but apparently older than the solar systemGeochemical Journal, Vol. 22, pp. 139-142GlobalAge determinations, Experimental
DS1990-0105
1990
Akagi, T.Akagi, T.Genesis of diamonds and behaviour of trace elements in seawater.*JPNGeochemistry, *JPN., Vol. 24, No. 1, pp. 1-12GlobalGeochemistry, Diamond genesis
DS2002-0799
2002
Akagi, T.Kagi, H., Sato, S., Kanda, T., Akagi, T.Internal strain and thermal history of carbonado inferred from photoluminescence spectroscopy: relationship to carbon isotopic compositions.Eos, American Geophysical Union, Spring Abstract Volume, Vol.83,19, 1p.Central African RepublicDiamond - morphology, carbonado
DS0812-0010
2008
Akai, C.Akai, C.K richterite olivine phlogopite diopside sanidine lamproites from the Afyon volcanic province, Turkey.Geological Magazine, Vol. 145, 4, pp. 570-585.Europe, TurkeyLamproite
DS0812-0919
2008
Akai, C.Prelevic, D., Boev, B., Zouros, N., Akai, C.Lamproites and alkaline rocks of southern Balkans and Aegean region.9th. IKC Field Trip Guidebook, CD 45p.Europe, Macedonia, Greece, TurkeyGuidebook - lamproites
DS1012-0597
2010
Akai, C.Prelevic, D., Akai, C., Romer, R.L., Foley, S.F.Lamproites as indicators of accretion and/or shallow subduction in the assembly of south western Anatolia, Turkey.Terra Nova, in press available,Europe, TurkeyLamproite
DS1990-0106
1990
Akaishi, M.Akaishi, M., Kanda, H., Yamoka, S.Synthesis of diamond from graphite-carbonate systems under very high temperature and pressureJournal of Crystal Growth, Vol. 104, pp. 578-581GlobalDiamond synthesis, Experimental mineralogy
DS1993-0015
1993
Akaishi, M.Akaishi, M., Kanda, H., Yamaoka, S.Phosphorous: an elemental catalyst for diamond synthesis and growthScience, Vol. 259, No. 5101, March 12, pp. 1592-1593GlobalDiamond synthesis
DS1993-0041
1993
Akaishi, M.Arima, M., Nakayama, K., Akaishi, M., Yamaoka, S., Kanda, H.Crystallization of diamond from a silicate melt of kimberlite composition in high temperature and high pressure experiments.Geology, Vol. 21, No. 11, November pp. 968-970.GlobalDiamond genesis, Experimental petrology
DS2002-0057
2002
Akaishi, M.Arima, M., Kozai, Y., Akaishi, M.Diamond nucleation and growth by reduction of carbonate melts under high pressure and high temperature conditions.Geology, Vol.30,8,Aug.pp.691-4.MantleGenesis - diamond morphology
DS1012-0598
2010
Akal, C.Prelevic, D., Akal, C., Foley, S.F., Romer, R.L., Stracke, A., Van den Bogaard,P.Post collisional mantle dynamics of an orogenic lithosphere: lamproitic mafic rocks from SW Anatolia, Turkey.Geological Society of America Abstracts, 1p.Europe, TurkeyLamproite
DS1112-0824
2011
Akal, C.Prelevic, D., Akal, C., Foley, S.F., Romer, R.R.,Stracke, 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 held Tubingen Germany June 16-18, PosterEurope, TurkeyAlkalic
DS1112-0825
2011
Akal, C.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
DS1112-0826
2011
Akal, C.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
DS1512-1970
2015
Akam, C.Simandl, G.J., Akam, C., Paradis, S.Selected critical materials: uses, markets, and resources.Symposium on critical and strategic materials, British Columbia Geological Survey Paper 2015-3, held Nov 13-14 2015, pp. 1-4.GlobalStrategic materials
DS1801-0063
2017
Akam, C.Simandl, G.J., Mackay, D.A.R., Ma, X., Luck, P., Gravel, J., Akam, C.The direct indicator mineral concept and QEMSCAN applied to exploration for carbonatite and carbonatite related ore deposits.in: Ferbey, T. Plouffe, A., Hickein, A.S. eds. Indicator minerals in tills and stream sediments of the Canadian Cordillera. Geological Association of Canada Special Paper,, Vol. 50, pp. 175-190.Canada, British Columbiacarbonatite - Aley, Lonnie, Wicheeda

Abstract: This volume consists of a series of papers of importance to indicator minerals in the Canadian Cordillera. Topics include the glacial history of the Cordilleran Ice Sheet, drift prospecting methods, the evolution of survey sampling strategies, new analytical methods, and recent advances in applying indicators minerals to mineral exploration. This volume fills a notable knowledge gap on the use of indicator minerals in the Canadian Cordillera. We hope that the volume serves as a user guide, encouraging the wider application of indicator minerals by the exploration community.
DS0712-0006
2007
Akaogi, M.Akaogi, M.Phase transitions of minerals in the transition zone and upper part of the lower mantle.Ohtani: Advances in high pressure mineralogy, pp. 1-14.MantleMineralogy
DS1212-0333
2012
Akaogi, M.Ishii, T., Kojitani, H., Akaogi, M.High pressure phase transitions and subduction behaviour of continent crust at pressure temperature conditions up to the upper part of the lower mantle.Earth and Planetary Science Letters, Vol. 357-358, pp. 31-41.MantleSubduction
DS1802-0218
2018
Akaogi, M.Akaogi, M., Kawahara, A., Kojitani, H., Yoshida, K., Anegawa, Y., Ishii, T.High pressure phase transitions in MgCr2O4 MgSiO4 composition: reactions between olivine and chromite with implications for ultrahigh pressure chromitites.American Mineralogist, Vol. 103, pp. 161-170.Mantlechromites
DS1975-0232
1976
Akaogi, M.Aoki, K., Fujino, K., Akaogi, M.Titanochondrite and Titanoclinohumite Derived from the Upper Mantle in the Buell Park Kimberlite, Arizona.Contributions to Mineralogy and Petrology, Vol. 56, PP. 243-253.GlobalKimberlite, Colorado Plateau, Rocky Mountains
DS2000-0542
2000
Akaogi, M.Kubo, A., Akaogi, M.Post garnet transitions in the system up to 28 Gpas: phase relations of garnet, ilmenite and perovskite.Physical Earth and Planetary Interiors, Vol. 121, No. 1-2, pp.85-102.GlobalGarnets, Perovskite
DS2000-0943
2000
Akaogi, M.Suzuki, T., Akaogi, M., Nakamura, E.Partioning of major elements between garnet structured minerals and silicate melt at pressure3-15 GPa.Physical Earth and Planetary Interiors, Vol. 120, No.1-2, pp. 79-92.GlobalPetrology - experimental, Garnet - silicate melts
DS2002-0013
2002
Akaogi, M.Akaogi, M., Tanaka, A., Ito, E.Garnet ilmenite perovskite transitions in the system ... at high pressures and high temperatures: phase equilibria, colorimetry and implications for mantle structurePhysics of the Earth and Planetary Interiors, Vol. 132, 4, pp. 303-24.MantleStructure - UHP
DS1985-0002
1985
Akasaka, M.Akasaka, M., Ohashi, H.57 Iron Mossbauer Study of Synthetic Iron 3 MelilitesPhysics Chem. Minerals, Vol. 12, No. 1, PP. 13-18.GlobalExperimental Petrology
DS0612-0628
2005
Akatkin, V.N.Ivanov, V.V., Kolesova, L.G., Khanchuk, A.I., Akatkin, V.N., Molchanova, G.B., Nechaev, V.P.Find of diamond crystals in Jurassic rocks of the Meymechite picrite complex in the Sikhote Alin Orogenic belt.Doklady Earth Sciences, Vol. 404, 7, pp. 975-978.RussiaPicrite
DS1984-0004
1984
Akbari, G.E.Akbari, G.E.The Origin and Evolution of the Earth; S Atmosphere and Hydrosphere.Ph.d. Thesis, University of Georgia (athens), 169P.GlobalExperimental, Fluid Inclusions, Diamonds, Models
DS0612-0194
2005
Akber-Knutson, S.Bukowinski, M.S.T., Akber-Knutson, S.The role of theoretical mineral physics in modeling the Earth's interior.American Geophysical Union, Geophysical Monograph, ed. Van der Hilst, Earth's Deep mantle, structure ...., No. 160, pp. 137-164.MantleGeophysics - seismics
DS0712-1041
2007
Akber-Knutson, S.Steinle-Neumann, G., Lee, K.K.M., Akber-Knutson, S.Potassium partitioning in the lowermost mantle from ab-initio computations.Plates, Plumes, and Paradigms, 1p. abstract p. A971.MantleGeodynamics
DS0412-0011
2003
AKD LimitedAKD LimitedAKD recovers another 244 diamonds at Abaete. Lico target.MiningNews.net, May 16, 1p.South America, BrazilNews item - press release
DS1999-0006
1999
Akelaitis, D.Akelaitis, D.Recent developments for migrating individualsThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin) ., Vol. 92, No. 1033, Sept. pp. 109-110.CanadaEconomics - tax
DS1970-0459
1972
Akella, J.Akella, J., Boyd, F.R.Partioning of Titanium and Aluminum Between Pyroxenes, Garnets and OxideCarnegie Institute Yearbook, 1971, PP. 378-384.IndiaMineral Chemistry, Experimental Petrology
DS1970-0460
1972
Akella, J.Akella, J., Boyd, F.R.Partitioning of Titanium and Aluminum between Pyroxenes, Garnets and oxides.Carnegie Institute Yearbook, FOR 1971, PP. 378-384.Lesotho, South AfricaMatsoku, Skaergaard, Research
DS1970-0860
1974
Akella, J.Akella, J.Solubility of Al203 in Orthopyroxene Coexisting with Garnet and Clinopyroxene for Compositions in the Diopside Pyrope Join in the System Casi03 Mgsi03 Al203.Carnegie Institute Yearbook, FOR 1973, PP. 273-277.GlobalMineralogy
DS1970-0861
1974
Akella, J.Akella, J., Boyd, F.R.Petrogenetic Grid for Garnet LherzolitesCargegie Institute Yearbook For 1973, PP. 269-273.South AfricaMineral Chemistry, Petrography
DS1975-0441
1977
Akella, J.Akella, J., Mccallister, R.H., Meyer, H.O.A.Mineralogical Studies on the Diamondiferous Kimberlite of The Wajrakarur Area Southern India #1University of California LAWRENCE LIVERMORE LAB., National Technical Information Service Report No. 7807, 21P.India, Andhra PradeshMineralogy
DS1975-0906
1979
Akella, J.Akella, J., Rao, P.S., Mcallister, R.H., Boyd, F.R., Meyer, H.O.Mineralogical Studies on the Diamondiferous Kimberlite of The Wajrakarur Area, Southern India #2Proceedings of Second International Kimberlite Conference, Vol. 1, PP. 172-177.India, Andhra PradeshMineralogy
DS1810-2305
2018
Akensov, S.M.Chukanov, N.V., Rastsvetaeva, R.K., Kruszewski, L., Akensov, S.M., Rusakov, V., Britvin, S.N., Vozchikova, S.A.Siudaite, Na8(Mn2+2Na) Ca6Fe3+3Zr3NbSi25O74(OH)2Cl.5H20: a new eudialyte group mineral from the Khibiny alkaline massif, Kola Peninsula.Physics and Chemistry of Minerals, Vol. 45, pp. 745-758.Russia, Kola Peninsulaalkaline

Abstract: The new eudialyte-group mineral siudaite, ideally Na8(Mn2+2Na)Ca6Fe3+3Zr3NbSi25O74(OH)2Cl•5H2O, was discovered in a peralkaline pegmatite situated at the Eveslogchorr Mt., Khibiny alkaline massif, Kola Peninsula, Russia. The associated minerals are aegirine, albite, microcline, nepheline, astrophyllite, and loparite-(Ce). Siudaite forms yellow to brownish-yellow equant anhedral grains up to 1.5 cm across. Its lustre is vitreous, and the streak is white. Cleavage is none observed. The Mohs’ hardness is 4½. Density measured by hydrostatic weighing is 2.96(1) g/cm3. Density calculated using the empirical formula is equal to 2.973 g/cm3. Siudaite is nonpleochroic, optically uniaxial, negative, with ??=?1.635(1) and e?=?1.626(1) (??=?589 nm). The IR spectrum is given. The chemical composition of siudaite is (wt%; electron microprobe, H2O determined by HCN analysis): Na2O 8.40, K2O 0.62, CaO 9.81, La2O3 1.03, Ce2O3 1.62, Pr2O3 0.21, Nd2O3 0.29, MnO 6.45, Fe2O3 4.51. TiO2 0.54, ZrO2 11.67, HfO2 0.29, Nb2O5 2.76, SiO2 47.20, Cl 0.54, H2O 3.5, -O?=?Cl -?0.12, total 99.32. According to Mössbauer spectroscopy data, all iron is trivalent. The empirical formula (based on 24.5 Si atoms pfu, in accordance wi