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SDLRC - Scientific Articles all years by Author - Do+


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 - Do+
Posted/
Published
AuthorTitleSourceRegionKeywords
DS201112-0271
2011
Do Cabo, V.Do Cabo, V., Sitnikova, M.A., Ellmies, R., Wall, F., Henjes-Kunst, F., Gerdes, A.Geological and geochemical characteristics of carbonatites of Lofdal, Namibia.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterAfrica, NamibiaCarbonatite
DS201112-0272
2011
Do Cabo, V.Do Cabo, V., Sitnikova, M.A., Elmies, R., Wall, F., Henjes-Kunst, F., Gerdes, A.Geological and geochemical characteristics of carbonatites of Lofdal, NamibiaPeralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.140-143.Africa, NamibiaLofdal
DS201112-0273
2011
Do Cabo, V.Do Cabo, V., Sitnikova, M.A., Elmies, R., Wall, F., Henjes-Kunst, F., Gerdes, A.Geological and geochemical characteristics of carbonatites of Lofdal, NamibiaPeralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.140-143.Africa, NamibiaLofdal
DS201412-0195
2014
Do Cabo, V.Do Cabo, V.Geology of the heavy rare earth element-rich Lofdal alkaline carbonatite complex, north west Namibia.ima2014.co.za, PosterAfrica, NamibiaCarbonatite
DS201112-0274
2011
Do Cabo, V.N.Do Cabo, V.N., Wall, F., Sitnikova, M.A., Ellmies, R., Henjes-Kunst, F., Gerdes, A., Downes, H.Mid and heavy REE in carbonatites at Lofdal, Namibia.Goldschmidt Conference 2011, abstract p.770.Africa, NamibiaCarbonatite, dykes
DS2001-1230
2001
Do Carmo Menezes, A.Wernick, E., Do Carmo Menezes, A.The Late Precambrian Potassium alkaline magmatism in the Riberia Fold Belt: a case study of the Piracaiai PlutonJournal of African Earth Sciences, Vol. 19, No. 3, Apr. pp.347-74.Brazil, Sao PauloAlkaline magmatism - not specific to diamonds
DS201809-1992
2018
do Couto Tokashiki, C.Babinski, M., McGee, B., do Couto Tokashiki, C., Tassinari, C.C.G., Souza Saes, G., Cavalante Pinho, F.E.Comparing two arms of an orogenic belt during Gondwana amalgamation: age and provenance of Cuiaba Group, northern Paraguay, Brazil.South American Earth Sciences, Vol. 85, pp. 6-42.South America, Brazilgeochronology

Abstract: The Cuiabá Group is the basal part of the sequence of passive margin sediments that unconformably overly the Amazonian Craton in central Brazil. Despite these rock's importance in understanding Brazil's path in the supercontinent cycle from Rodinia to Gondwana and their potential record of catastrophic glaciation their internal stratigraphy and relationship to other units is still poorly understood. The timing of deposition and source areas for the subunits of the Cuiabá Group sedimentary rocks are investigated here using integrated U-Pb and Sm-Nd isotope data. We sampled in the northern Paraguay Belt, a range that developed in response to the collision between the Amazonian Craton, the Rio Apa Block, the São Francisco Craton and the Paranapanema Block. 1125 detrital zircon LA-ICPMS U-Pb ages were calculated and 22 whole rock samples were used for Sm-Nd isotope analysis. The U-Pb ages range between Archean and Neoproterozoic and the main source is the Sunsás Province. Moving up stratigraphy there is a subtle increase in slightly younger detritus with the youngest grain showing an age of 652?±?5 Ma, found at the top of the sequence. The age spectra are similar across each of the sampled units and when combined with the Sm-Nd data, indicate that the source of the detritus was mostly similar throughout deposition. This is consistent with the analysis here that indicates sedimentation occurred in a passive margin environment on the southern margin of the Amazonian Craton. The maximum depositional age of 652?±?5 Ma along with the age of the overlying cap carbonate of the Mirassol d’Oeste Formation suggests that part of this section of sediments were deposited in the purportedly global ~636 Ma Marinoan glaciation, although we give no sedimentological evidence for glaciation in the study area. Compared to the southern Paraguay Belt where no direct age constraints exist, the glacial epoch could be either Cryogenian or Ediacaran. In addition, available data in the literature indicates a diachronous evolution between the northern and southern arms of the Paraguay Belt in the final stages of deposition and deformation.
DS201702-0210
2017
Doallo, R.Deibe, D., Amor, M., Doallo, R., Miranda, M., Cordero, M.GVLiDAR: an interactive web-based visualization frameowrk to support geospatial measures on lidar data.International Journal of Remote Sensing, Vol. 38, 3, pp. 827-849.TechnologyLIDAR

Abstract: In recent years lidar technology has experienced a noticeable increase in its relevance and usage in a number of scientific fields. Therefore, software capable of handling lidar data becomes a key point in those fields. In this article, we present GPU-based viewer lidar (GVLiDAR), a novel web framework for visualization and geospatial measurement of lidar data point sets. The design of the framework is focused on achieving three key objectives: performance in terms of real-time interaction, functionality, and online availability for the lidar datasets. All lidar files are pre-processed and stored in a lossless data structure, which minimizes transfer requirements and offers an on-demand lidar data web framework.
DS1993-1732
1993
Dobb, A.Williams, G.D., Dobb, A.Tectonics and seismic sequence stratigraphyGeological Society of London Special Publication, No. 71, 230pNamibia, North Sea, France, SpainTable of contents, Tectonics, rifting, basin
DS1998-1413
1998
DobbeStiefenhofer, J., Viljoen, K.S., Tainton, K.M., DobbeThe petrology of a mantle xenolith suite from Venetia, South Africa #17th International Kimberlite Conference Abstract, pp. 868-70.South AfricaPeridotite, Deposit - Venetia
DS1999-0716
1999
DobbeStiefenhofer, J., Voljoen, Tainton, Dobbe, HannwegThe petrology of a mantle xenolith suite from Venetia, South Africa #27th International Kimberlite Conference Nixon, Vol. 2, pp. 836-45.South AfricaXenoliths, petrography, mineral chemistry, geothermomet, Deposit - Venetia
DS2003-0024
2003
Dobbe, R.Appleyard, C.M., Viljoen, K.S., Dobbe, R.A study of eclogitic diamonds and their inclusions from the Finsch kimberlite pipe8 Ikc Www.venuewest.com/8ikc/program.htm, Session 2, AbstractSouth AfricaEclogites, diamonds, melting, Deposit - Finsch
DS2003-0994
2003
Dobbe, R.Naldoo, P., Stiefenhofer, J., Field, M., Dobbe, R.Recent advances in the geology of Koffiefontein mine, Free State Province, South8 Ikc Www.venuewest.com/8ikc/program.htm, Session 1, AbstractSouth AfricaGeology, economics, Deposit - Koffiefontein
DS2003-1429
2003
Dobbe, R.Viljoen, K.S., Dobbe, R.A Diamondiferous lherzolite from the Premier diamond mine, South Africa8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, POSTER abstractSouth AfricaDeposit - Premier
DS200412-0044
2003
Dobbe, R.Appleyard, C.M., Viljoen, K.S., Dobbe, R.A study of eclogitic diamonds and their inclusions from the Finsch kimberlite pipe, South Africa.8 IKC Program, Session 2, AbstractAfrica, South AfricaEclogite, diamonds, melting Deposit - Finsch
DS200412-0045
2004
Dobbe, R.Appleyard, C.M., Viljoen, K.S., Dobbe, R.A study of eclogitic diamonds and their inclusions from the Finsch kimberlite pipe, South Africa.Lithos, Vol. 77, 1-4, Sept. pp. 317-332.Africa, South AfricaProterozoic, dodecahedra, deformation, type IaAB, plate
DS200412-1400
2003
Dobbe, R.Naldoo, P., Stiefenhofer, J., Field, M., Dobbe, R.Recent advances in the geology of Koffiefontein mine, Free State Province, South Africa.8 IKC Program, Session 1, AbstractAfrica, South AfricaGeology, economics Deposit - Koffiefontein
DS200412-2059
2004
Dobbe, R.Vijoen, K.S., Dobbe, R., Smit, B., Thomassot, E., Cartigny, P.Petrology and geochemistry of a Diamondiferous lherzolite from the Premier diamond mine, South Africa.Lithos, Vol. 77, 1-4, Sept. pp. 539-552.Africa, South AfricaPeridotite, infrared analysis, nitrogen, diamond morpho
DS200412-2061
2003
Dobbe, R.Viljoen, K.S., Dobbe, R.A Diamondiferous lherzolite from the Premier diamond mine, South Africa.8 IKC Program, Session 6, POSTER abstractAfrica, South AfricaMantle petrology Deposit - Premier
DS200912-0798
2009
Dobbe, R.Viljoen, F., Dobbe, R., Smit, B.Geochemical processes in peridotite xenoliths from the Premier diamond mine, South Africa: evidence -depletion and refertilization of subcratonic lithosphere.Lithos, In press availableAfrica, South AfricaDeposit - Premier
DS201012-0820
2010
Dobbe, R.Viljoen, F., Dobbe, R., Harris, J., Smit, B.Trace element chemistry of mineral inclusions in eclogitic diamonds from the Premier ( Cullinan) and Finsch kimberlites: implications for evolution mantleLithos, Vol. 118, 1-2, pp. 156-168.Africa, South AfricaDiamond genesis, source
DS1990-0409
1990
Dobbs, P.N.Dobbs, P.N., Guo Yaping, Hu Siyi, Lin Jianrong, Luo Lianquan, ZangA sedimentological study of Diamondiferous Quaternary sediments in southern Shandong ChinaGeol. Journal, Vol. 25, pp. 47-59ChinaSedimentology, Diamond sediments
DS1991-0384
1991
Dobbs, P.N.Dobbs, P.N., Duncan, D.J., Hu, S., Shee, S.R., Colgan, E.A., BrownThe geology of the Mengyin kimberlites, Shandong, ChinaProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 76-78ChinaDiamond exploration, Mineral sampling
DS1994-0434
1994
Dobbs, P.N.Dobbs, P.N., Duncan, D.J., Hu, S., Shee, S.R., Colgan, E.A., BrownThe geology of the Mengyin kimberlites, Shandong ChinaProceedings of Fifth International Kimberlite Conference, Vol. 1, pp. 40-61.ChinaKimberlite, Deposit -Mengyin
DS2002-1199
2002
Dobe, P.Paava, J., Kabek, B., Dobe, P., VavAn, I., et al.Tin polymetric sulphide deposits in the eastern part of the Dachang tin field and role of black shales - originMineralium deposita, China, southCopper, sinx, tin, black shales, metallogeny, Deposit - Dachang
DS1975-0068
1975
Dobecki, T.L.Dobecki, T.L., Lafountain, L.J.Seismicity and Structure Along a Portion of the Midcontinent Geophysical Anomaly.Eos, Vol. 56, No. 9, PP. 602-603. (abstract.).KansasMid-continent
DS201112-0275
2011
Dobinski, W.Dobinski, W.Permafrost - review of definition, terminologies, history, processes, ageEarth Science Reviews, Vol. 108, no. 3-4, Oct. pp. 158-169.GlobalPermafrost review
DS1997-0878
1997
Doblas, M.Oyarzun, R., Doblas, M., Lopez-Ruiz, J., Cebria, .M.Opening of the central Atlantic and asymmetric mantle upwelling phenomena:implications long lived magmatismGeology, Vol. 25, No. 8, August pp. 727-730Mantle, North America, North AtlanticMagma, tectonics, rift, Tholeiite, alkaline
DS2002-0385
2002
Doblas, M.Doblas, M., Lopez Ruiz, J., Cebria, J.M., Youbi, N., De Groote, E.Mantle insulation beneath the West African Craton during the Precambrian Cambrian transition.Geology, Vol. 30, 9, Sept. pp. 839-42.West AfricaGeothermometry
DS2002-0386
2002
Doblas, M.Doblas, M., Lopez-Ruiz, J., Cebria, J-M., Youbi, N., Degroote, E.Mantle insulation beneath the West African craton during Precambrian - Cambrian transition.Geology, Vol. 30,9,Sept. pp. 839-42.West Africa, BrazilGeothermometry, African Craton
DS200512-0235
2005
Dobolev, A.V.Dobolev, A.V., Hofmann, A.W., Sobolev, S.V., Nikogosian, I.K.An olivine free mantle source of Hawaiian shield basalts.Nature, No. 7033, March 31, pp. 590-597.Mantle, HawaiiGeochemistry
DS201112-0276
2011
Doboshkevich, A.G.Doboshkevich, A.G., Ripp, G.S., Savatenkov, V.M.Alkaline magmatism of Vitim Province West Transbaikalia, Russia: age, mineralogical, geochemical and isotope (O, C,D,Sr,Nd) data.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.35-38.RussiaIjolite
DS201112-0277
2011
Doboshkevich, A.G.Doboshkevich, A.G., Ripp, G.S., Savatenkov, V.M.Alkaline magmatism of Vitim Province West Transbaikalia, Russia: age, mineralogical, geochemical and isotope (O, C,D,Sr,Nd) data.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.35-38.RussiaIjolite
DS201112-0867
2011
Doboshkevich, A.G.Ripp, G.S., Doboshkevich, A.G., Ripp, G.S., Lastochkin, Izbrodin, RampilovA way of carbonatite formation from alkaline gabbros, Oshurkovo massif.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.39-41.RussiaOshurkovo
DS201112-0868
2011
Doboshkevich, A.G.Ripp, G.S., Doboshkevich, A.G., Ripp, G.S., Lastochkin, Izbrodin, RampilovA way of carbonatite formation from alkaline gabbros, Oshurkovo massif.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.39-41.RussiaOshurkovo
DS1991-0493
1991
Dobosi, G.Fodor, R.V., Dobosi, G.Magma fractionation, replenishment and mixing as inferred from green ore clinopyroxenes in Pliocene basanite, southern SlovakiaGeological Society of America Annual Meeting Abstract Volume, Vol. 23, No. 5, San Diego, p. A 443Hungary, CzechoslovakiaBasanite, Petrology
DS1998-0355
1998
Dobosi, G.Dobosi, G., Jenner, G.A., Embey-Isztin, A.Clinopyroxene orthopyroxene trace element partition coefficients in spinel peridotite xenoliths.Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 393-4.Europe, Pannonian BasinLherzolite xenoliths
DS2000-0547
2000
Dobosi, G.Kurat, G., Dobosi, G.Garnet and diopside bearing diamondites ( framesites)Mineralogy and Petrology., Vol. 69, No. 3-4, pp. 143-60.GlobalMineralogy - bort
DS2002-0387
2002
Dobosi, G.Dobosi, G., Kurat, G.Trace element abundances in garnets and clinopyroxenes from diamondites - a signature of carbonatitic fluids.Mineralogy and Petrology, Vol. 76, 1-2, pp.21-38.GlobalMineral chemistry
DS2002-0388
2002
Dobosi, G.Dobosi, G., Kurat, G.Trace element abundances in garnets and clinopyroxenes from diamondites - a signature of carbonatitic fluids.Mineralogy and Petrology, Vol. 76, No. 1-2, pp. 21-38.GlobalPetrology, Carbonatite
DS200412-0439
2004
Dobosi, G.Demeny, A., Vennemann, T.W., Hegner, E., Nagy, G., Milton, J.A., Embey-Isztin, A., Homonnay, Z., Dobosi, G.Trace element and C O Sr Nd isotope evidence for subduction related carbonate silicate melts in mantle xenoliths ( Pannonian BasLithos, Vol. 75, 1-2, July pp. 89-113.Europe, HungarySubduction, trace element fingerprinting, petrogenetic
DS200412-1234
2004
Dobosi, G.Maruoka, T., Kurat, G., Dobosi, G., Koeberl, C.Isotopic composition of carbon in diamonds of diamondites: record of mass fractionation in the mantle.Geochimica et Cosmochimica Acta, Vol.68, 7, pp. 1635-1644.MantleGeochronology
DS200612-0826
2005
Dobosi, G.Litvin, Y.A., Kurat, G., Dobosi, G.Experimental study of diamondite formation in carbonate silicate melts: a model approach to natural processes.Russian Geology and Geophysics, Vol. 46, 12, pp. 1285-1299.TechnologyModeling - diamondite
DS200712-0043
2006
Dobosi, G.Azbej, T., Szabo, C., Bodnar, R.J., Dobosi, G.Genesis of carbonate aggregates in lamprophyres from the northeastern Transnubian central range, Hungary: magmatic or hydrothermal origin?Mineralogy and Petrology, Vol. 88, 3-4, pp. 479-497.Europe, HungaryLamprophyre - not specific to diamonds
DS200712-0253
2007
Dobosi, G.Dobosi, G., Wall, F., Jeffries, T.Trace element fractionation during exsolution of garnet from clinopyroxene in an eclogite xenolith from Obnazhennaya(Siberia).Plates, Plumes, and Paradigms, 1p. abstract p. A227.Russia, SiberiaObnazhennaya
DS201012-0158
2010
Dobosi, G.Dobosi, G., Kurat, G.On the origin of silicate bearing diamondites.Mineralogy and Petrology, Vol. 99, 1-2, pp. 29-42.TechnologyBort, aggregates, diamondites
DS201012-0496
2010
Dobosi, G.Mikhail, S., Dobosi, G., Verchovsky, S., Jones, A., Kurat, G.Organic looking carbon and nitrogen isotope compositions in mantle derived diamondites: mantle fractionation vs reworked crustal organics?International Mineralogical Association meeting August Budapest, abstract p. 185.Africa, southern AfricaDiamondites
DS201312-0602
2013
Dobosi, G.Mikhail, S., Dobosi, G., Verchovsky, A.B., Kurat, G., Jones, A.P.Peridotitic and websteritic diamondites provide new information regarding mantle melting and metasomatism induced through the subduction of crustal volatiles.Geochimica et Cosmochimica Acta, Vol. 107, Apr. 15, pp. 1-11.MantleDiamondites
DS201312-1005
2013
Dobosi, G.Zartman, R.E., Kempton, P.D., Kempton, J.B., Paces, H.D., Williams, I.S., Dobosi, G.,Futa, K.Lower crustal xenoliths from Jurassic kimberlite diatremes, Upper Michigan USA: evidence for Proterozoic orogenesis and plume magmatism in the lower crust of the southern Superior Province.Journal of Petrology, Vol. 54, 3, pp. 575-608.United States, MichiganDeposit - Lake Ellen, S69, S10
DS201412-0042
2014
Dobosi, G.Batki, A., Pal-Molnar, E., Dobosi, G., Skelton, A.Petrogenetic significance of ocellar camptonite dykes in the Ditrau alkaline Massif, Romania.Lithos, Vol. 200-201, pp. 181-196.Europe, RomaniaCamptonite
DS1988-0174
1988
Dobozi, I.Dobozi, I.Emergence, performance and world market impact of state mineral enterprises in developing countries: a state of the art reviewColorado School of Mines Department of Mineral Economics, Working Paper No. 88-11, 22p. Database # 17585GlobalEconomics, Developing countries -economics
DS1988-0175
1988
Dobozi, I.Dobozi, I.Centrally planned economiesPreprint Resources for the Future Book to be published 1989 Chapter 5, 80p. Database # 17758GlobalEconomics, Metal demand
DS1995-0423
1995
Dobra, J.L.Dobra, J.L., Bigler, L.M.Cost of acquisition and finding vs U.S. mineral Land's valueEngineering and Mining Journal, Vol. 196, No. 6, p. 16NN-16OO. 2pUnited StatesTaxation, Costs of exploration
DS2001-0260
2001
Dobran, F.Dobran, F.Volcanic processes: mechanism in material transport. Igneous materials, mantle convection, melt segregationKluwer Publ. www.kluwer.com 577p. Nov. approx. $ 100.00 US, 577p. Nov. approx. $ 100.00 USGlobalBook - magma chambers, conduits, pyroclastics, Kimberlite mentioned p. 15 ( more processes)
DS2001-0261
2001
Dobran, F.Dobran, F.Volcanic processes: mechanism in material transport. Igneous materials, mantle convection, melt segregationKluwer Publ. www.kluwer.com 577p. Nov. approx. $ 100.00 US, 577p. Nov. approx. $ 100.00 USGlobalBook - magma chambers, conduits, pyroclastics, Kimberlite mentioned p. 15 ( more processes)
DS1986-0186
1986
Dobransky, D.W.Dobransky, D.W.Coal and clay mineral metamorphism associated with the Dixonville kimberlite dike, PennsylvaniaGeological Society of America, Vol. 18, No. 4, p. 286. (abstract.)GlobalBlank
DS1995-0424
1995
Dobretsov, N.I.Dobretsov, N.I., Shatsky, V.S., Sobolev, N.V.Comparison of the Kokchetav and Dabie Shan metamorphic complexes: coesite and diamond bearing rocks ultra high pressure (UHP)-HP...International Geology Review, Vol. 37, pp. 636-656.ChinaCoesite, metamorphism, Deposit -Kokchetav, Dabie Shan
DS200612-0336
2006
Dobretsov, N.I.Dobretsov, N.I., Buslov, M.M., Zhimulev, F.I., Travin, A.V., Zayachkovsky, A.A.Vendian Early Ordovician geodynamic evolution and model for exhumation of ultrahigh and high pressure rocks from the Kokchetav subduction collision zone.Russian Geology and Geophysics, Vol. 47, 4, pp. 424-440.Russia, KazakhstanUHP
DS201502-0103
2015
Dobretsov, N.I.Sobolev, N.V., Dobretsov, N.I., Ohtani, E., Taylor, L.A., Schertl, H-P., Palyanov, Yu.N.Problems related to crystallogenesis and the deep carbon cycle.Russian Geology and Geophysics, Vol. 56, 1-2, pp. 1-12.MantleCarbon cycle
DS1970-0874
1974
Dobretsov, N.L.Bakirov, A.B., Dobretsov, N.L., et al.Eclogite of the Atbashi Range Tien ShanDoklady Academy of Science USSR, Earth Science Section., Vol. 215, No. 1-6, PP. 125-128.RussiaKimberlite
DS1988-0176
1988
Dobretsov, N.L.Dobretsov, N.L., Dobretsova, L.V.New dat a on eclogites of CubaDoklady Academy of Science USSR, Earth Science Section, Vol. 292, No. 1-6, pp. 86-90GlobalEclogites
DS1991-0385
1991
Dobretsov, N.L.Dobretsov, N.L.Blueschists and eclogites: a possible plate tectonic mechanism for their emplacement from the upper mantleTectonophysics, Vol. 186, pp. 253-268Europe, CaliforniaEclogites, Mantle
DS1991-0386
1991
Dobretsov, N.L.Dobretsov, N.L., Ashchepkov, I.V.Composition and evolution of upper mantle in rift zonesSoviet Geology and Geophysics, Vol. 32, No. 1, pp. 1-7RussiaMantle, Tectonics -rifts
DS1991-0387
1991
Dobretsov, N.L.Dobretsov, N.L., Kirdyashkin, A.G.Dynamics of subduction zones: models of accretion wedge origin and upliftof blue schists and eclogitesSoviet Geology and Geophysics, Vol. 32, No. 3, pp. 4-19RussiaEclogites, Tectonics subduction zones
DS1992-0368
1992
Dobretsov, N.L.Dobretsov, N.L.Analysis of the geology of USSR in terms of plate tectonicsRussian Geology and Geophysics, Vol. 33, No. 6, pp. 125-RussiaTectonics, Plate tectonics
DS1993-0359
1993
Dobretsov, N.L.Dobretsov, N.L., Ashchepkov, I.V., Simonov, V.A., Zhmodik, S.M.Interaction of the upper-mantle rocks with deep seated fluids and melts In the Baikal rift zoneSoviet Geology and Geophysics, Vol. 33, No. 5, pp. 1-14Russia, Commonwealth of Independent States (CIS), BaikalTectonics, Geochemistry, Thermobarometry
DS1993-0360
1993
Dobretsov, N.L.Dobretsov, N.L., Buslov, M.M., Simonov, V.A.Associated ophiolites, glaucophane schists and eclogites of the GornyyAltai.Doklady Academy of Sciences USSR, Vol. 318, pp. 123-127.RussiaEclogites
DS1993-0361
1993
Dobretsov, N.L.Dobretsov, N.L., Kirdyashkin, A.G.Application of two layer convection to structural features and geodynamics of the earthRussian Geology and Geophysics, Vol. 34, No. 1, pp. 1-21RussiaStructure, Plumes, models, lithosphere, Mantle
DS1993-0362
1993
Dobretsov, N.L.Dobretsov, N.L., Kirdyashkin, A.G., Gladkov, I.N.Problems of deep seated geodynamics and modelling of mantle plumesRussian Geology and Geophysics, Vol. 34, No. 12, pp. 3-20.MantleGeodynamics, Mantle plumes
DS1993-0819
1993
Dobretsov, N.L.Kirdyashkin, Dobretsov, N.L.Modeling of two layer mantle convectionDoklady Academy of Sciences USSR, Vol. 318, pp. 73-77.MantleGeophysics
DS1993-0831
1993
Dobretsov, N.L.Knipper, A.L., Dobretsov, N.L., Bogdanov, N.A.Metaophiolites and orogenic lherzolites of the Betic CordillerasInternational Geology Review, Vol. 35, No. 5, pp. 467-484GlobalRhonda, Ojen massifs, Lherzolite
DS1993-0832
1993
Dobretsov, N.L.Knipper, A.L., Dobretsov, N.L., Bogdanov, N.A.Metaophiolites and orogenic lherzolites of the Betic CordillerasInternational Geology Review, Vol. 35, No. 5, pp. 467-484.GlobalRhonda, Ojen massifs, Lherzolite
DS1993-0833
1993
Dobretsov, N.L.Knipper, A.L., Dobretsov, N.L., Bogdanov, N.A.Metaophiolites and orogenic lherzolites of the Betic CordilleraInternational Geology Review, Vol. 35, No. 5, May pp. 467-484RussiaBetic lherzolites
DS1994-0067
1994
Dobretsov, N.L.Aschepekov, J.V., Litasov, Y.D., Dobretsov, N.L.Pyroxenites and composite garnet peridotite xenoliths picrite basalt Vitim plateau Trans Baikal: implication thermobarometry, reconstruction.Proceedings of Fifth International Kimberlite Conference, Vol. 1, pp. 455-466.Russia, BaikalXenoliths, Vitim Plateau
DS1994-0435
1994
Dobretsov, N.L.Dobretsov, N.L.Periodicity of geological processes and depth geodynamicsRussian Geology and Geophysics, Vol. 35, No. 5, pp. 2-14.RussiaTectonics
DS1995-0425
1995
Dobretsov, N.L.Dobretsov, N.L.Tectonics and metamorphism: problems of relationshipPetrology, (QE 420 P4), Vol. 3, No. 1, Jan-Feb. pp. 2-19RussiaTectonics, metamorphism
DS1995-0426
1995
Dobretsov, N.L.Dobretsov, N.L., Coleman, R.G., Ernst, W.G.Geotectonic evolution of diamond bearing paragneisses in the Kokchetav complex of northern Kazakhstan.Eos, Abstracts, Vol. 76, No. 17, Apr 25, p. S 291.Russia, KazakhstanParagneiss, Diamond
DS1996-0368
1996
Dobretsov, N.L.Dobretsov, N.L., Kirdyashkin, A.E.Heat and exchange and rheology of the lower mantle during early earthhistory.Doklady Academy of Sciences, Vol. 345A No. 9, October pp. 441-445.MantleRheology
DS1996-0369
1996
Dobretsov, N.L.Dobretsov, N.L., Shatsky, V.S., Beane, R.J.Tectonic setting and petrology of ultrahigh pressure metamorphic rocks In the Maksyutov Complex, Urals.International Geology Review, Vol. 38, No. 2, Feb. pp. 136-160.Russia, UralsPetrology, Tectonics
DS1997-0278
1997
Dobretsov, N.L.Dobretsov, N.L.Permian Triassic magmatism and sedimentation in Eurasia as a result of asuperplume.Doklady Academy of Sciences, in Eng., Vol. 354, No. 4, pp. 497-500.Europe, AsiaAlkaline magmatism, Superplume, hotspot
DS1997-0279
1997
Dobretsov, N.L.Dobretsov, N.L.Mantle superplumes as a cause of the main geological periodicity and globalreorganizations.Doklady Academy of Sciences, Vol. 355A, No. 6, July-Aug. pp. 1316-19.MantleDiapirs, Plumes, hot spots
DS1997-0280
1997
Dobretsov, N.L.Dobretsov, N.L., Kirdyashkin, A.G.Modeling of subduction processesRussian Geology and Geophysics, Vol. 38, No. 5, pp. 884-895.RussiaMagmatism, Subduction - not specific to diamonds
DS2000-0238
2000
Dobretsov, N.L.Dobretsov, N.L., Kirdyashkin, A.G.Sources of mantle plumesDoklady Academy of Sciences, Vol. 373, No. 5, June-July, pp.879-81.MantlePlumes - sources
DS2001-0262
2001
Dobretsov, N.L.Dobretsov, N.L., Vernikovsky, V.A.Mantle plumes and their geologic manifestationsInternational Geology Review, Vol. 43, No. 9, Sept. pp. 771-87.MantlePlumes, hot spots, Review
DS2001-0605
2001
Dobretsov, N.L.Kirdyashkin, A.G., Dobretsov, N.L., Kirdyashkin, A.A.Turbulent convection and magnetic field of the outer Earth's coreRussian Geology and Geophysics, Vol. 41, No. 5, pp. 579-592.MantleGeophysics - magnetics, Convection
DS2001-0691
2001
Dobretsov, N.L.Litasov, K.D., Ohtani, E., Dobretsov, N.L.Stability of hydrous phase in the Earth's mantleDoklady Academy of Sciences, Vol. 378, No. 4, pp. 456-9.MantleGeochemistry
DS2002-0855
2002
Dobretsov, N.L.Kirdyashkin, A.A., Dobretsov, N.L., Kirdyashkin, A.G.Experimental modeling of the influence of subduction on the spatial structure of convection currents in the asthenosphere under continents.Doklady, Vol.385,June-July, pp. 546-50.MantleSubduction
DS2003-0338
2003
Dobretsov, N.L.Dobretsov, N.L., Kirdyashkin, A.A., Kirdyashkin, A.G.Physicochemical conditions at the core-mantle boundary and formation ofDoklady Earth Sciences, MantleBlank
DS200412-0460
2003
Dobretsov, N.L.Dobretsov, N.L., Kirdyashkin, A.A., Kirdyashkin, A.G.Physicochemical conditions at the core-mantle boundary and formation of thermochemical plumes.Doklady Earth Sciences, Vol. 393A, 9, pp. 1319-1322.MantleGeothermometry
DS200412-0461
2004
Dobretsov, N.L.Dobretsov, N.L., Shatsky, V.S.Exhumation of high pressure rocks of Kokchetav massif: facts and models.Lithos, Vol. 78, 3, Nov. pp. 307-318.RussiaKumdy-dol diamondiferous domain, UHP melting
DS200512-0236
2004
Dobretsov, N.L.Dobretsov, N.L., Buslov, M.M.Serpentinitic melanges associated with HP and UHP rocks in central Asia.International Geology Review, Vol. 46, 11, pp. 957-980.China, AsiaUHP
DS200512-0237
2005
Dobretsov, N.L.Dobretsov, N.L., Buslov, M.M., Zhimulev, F.I., Travin, A.V.The Kochetav Massif as a deformed Cambrian-Early Caradocian collision subduction zone.Doklady Earth Sciences, Vol. 402, 4, pp. 501-505.RussiaSubduction
DS200512-0539
2005
Dobretsov, N.L.Kirdyashkin, A.A., Dobretsov, N.L., Kirdyashkin, A.G., Gladkov, I.N., Surkov, N.V.Hydrodynamic processes associated with plume rise and conditions for eruption conduit formation.Russian Geology and Geophysics, Vol. 46, 9, pp. 869-885.MantleGeodynamics
DS200612-0337
2006
Dobretsov, N.L.Dobretsov, N.L., Kirdyashkin, A.A., Kirdyashkin, A.G., Gladkov, I.N., Surkov, N.V.Parameters of hotspots and thermochemical plumes during their ascent and eruption.Petrology, Vol. 14, 5, pp. 477-491.MantleGeothermometry - hot spots
DS201012-0159
2010
Dobretsov, N.L.Dobretsov, N.L.Distinctive petrological, geochemical, and geodynamic features of subduction related magmatism.Petrology, Vol. 18, 1, pp. 84-106.MantleSubduction, eclogitization
DS201112-0278
2010
Dobretsov, N.L.Dobretsov, N.L., Polyansky, O.P.On formation mechanisms of deep sedimentary basins: is there enough evidence for eclogitization?Russian Geology and Geophysics, Vol. 51, pp. 1314-1321.MantleGeodynamics, rifting
DS201212-0336
2012
Dobretsov, N.L.Jakovlev, A.V., Bushenkova, N.A., Koulakov, I.yu., Dobretsov, N.L.Structure of the upper mantle in the circum-artic region from regional seismic tomography.Russian Geology and Geophysics, Vol. 53, 10. pp. 963-971.RussiaGeophysics - seismic
DS201312-0215
2013
Dobretsov, N.L.Dobretsov, N.L., Buslov, M.M., De Grave, J., Sklyarov, E.V.Interplay of magmatism, sedimentation, and collision processes in the Siberian craton and the flanking orogens.Russian Geology and Geophysics, Vol. 54, 10, pp. 1135-1149.RussiaMagmatism
DS201312-0216
2012
Dobretsov, N.L.Dobretsov, N.L., Shatskiy, A.F.Deep carbon cycle and geodynamics: the role of the core and carbonatite melts in the lower mantle.Russian Geology and Geophysics, Vol. 53, pp. 1117-1132.MantleCarbonatite
DS201502-0047
2015
Dobretsov, N.L.Buslov, M.M., Dobretsov, N.L., Vovna, G.M., Kiselev, V.I.Structural location, composition, and geodynamic nature of diamond bearing metamorphic rocks of the Kokchetav subduction-collision zone of the Central Asian Fold Belt ( Northern Kazakhstan).Russian Geology and Geophysics, Vol. 56, 1-2, pp. 64-80.Russia, KazakhstanKokchetav massif

Abstract: We present data on different aspects of geology, mineralogy, petrology, geochemistry, and geochronology of diamond-bearing metamorphic rocks of the Kumdy-Kol terrane, which show the similarity of their protolith to the sedimentary rocks of the Kokchetav microcontinent. The structural location of the studied objects in the accretion-collision zone evidences that the subduction of the Kokchetav microcontinent beneath the Vendian-Cambrian Ishim-Selety island arc is the main mechanism of transport of graphite-bearing terrigenous-carbonate rocks to zones of their transformation into diamond-bearing metamorphic rocks. The sedimentary rocks of the Kokchetav microcontinent, which are enriched in graphite and iron sulfides and carbonates, contain all components necessary for diamond crystallization in deep-seated subduction zone. This is in agreement with the experimental data and the compositions of fluid-melt inclusions in the minerals of diamond-bearing rocks.
DS201502-0054
2015
Dobretsov, N.L.Dobretsov, N.L., Koulakov, I.Yu., Litasov, K.D., Kukarina, E.V.An integrated model of subduction: contributions from geology, experimental petrology and seismic tomography.Russian Geology and Geophysics, Vol. 56, 1-2, pp. 13-38.MantleSubduction
DS201507-0309
2015
Dobretsov, N.L.Dobretsov, N.L., Zedgenizov, D.A., Litasov, K.D.Evidence for and consequences of the "hot" subduction model.Doklady Earth Sciences, Vol. 461, 1, pp. 517-521.MantleSubduction
DS201507-0320
2015
Dobretsov, N.L.Lazereva, E.V., Zhmodik, S.M., Dobretsov, N.L., Tolstov, A.V., Shcherbov, B.L., Karmanov, N.S., Gerasimov, E.Yu., Bryanskaya, A.V.Main minerals of abnormally high grade ores of the Tomtor deposit ( Arctic Siberia).Russian Geology and Geophysics, Vol. 56, pp. 844-873.RussiaDeposit - Tomtor
DS201509-0394
2015
Dobretsov, N.L.Dobretsov, N.L., Turkina, O.M.Early Precambrian Earth history: plate and plume tectonics and extraterrestrial controls.Russian Geology and Geophysics, Vol. 56, pp. 978-995.MantleSubduction

Abstract: The Hadean and Archean geologic history of the Earth is discussed in the context of available knowledge from different sources: space physics and comparative planetology; isotope geochronology; geology and petrology of Archean greenstone belts (GB) and tonalite-trondhjemite-granodiorite (TTG) complexes; and geodynamic modeling review to analyse plate-tectonic, plume activity, and impact processes. Correlation between the age peaks of terrestrial Hadean-Early Archean zircons and late heavy bombardment events on the Moon, as well as the Hf isotope composition of zircons indicating their mostly mafic sources, hint to an important role of impact processes in the Earth’s history between 4.4 and 3.8 Ga. The earliest continental crust (TTG complexes) formed at 4.2 Ga (Acasta gneisses), while its large-scale recycling left imprint in Hf isotope signatures after 3.75 Ga. The associations and geochemistry of rocks suggest that Archean greenstone belts formed in settings of rifting, ocean floor spreading, subduction, and plume magmatism generally similar to the present respective processes. The Archean history differed in the greater extent of rocks derived from mantle plumes (komatiites and basalts), boninites, and adakites as well as in shorter subduction cycles recorded in alternation of typical calc-alkaline andesite-dacite-rhyolite and adakite series that were generated in a hotter mantle with more turbulent convection and unsteady subduction. The Archean is interpreted as a transient period of small plate tectonics.
DS201602-0202
2015
Dobretsov, N.L.Dobretsov, N.L.Periodicity and driving forces of volcanism.Russian Geology and Geophysics, Vol. 56, pp. 1663-1670.Global, JapanMantle plume

Abstract: The volume and style of volcanism change periodically, with cycles of three main scales, which have different causes and effects. Short cycles of volcanic activity last from tens to thousands of years and are associated with periodic accumulation of magma in shallow chambers and its subsequent eruptions. The eruptions either have internal causes or are triggered externally by variations in solar activity, tidal friction, and Earth’s rotation speed. Medium-scale cycles, hundreds of thousands to millions of years long, are due to changes in spreading and subduction rates. Long cycles (30–120 Ma) are related to ascent of mantle plumes, which take away material and heat from the core-mantle boundary and change the convection rate. These appear to be the major controls of the average periodicity. Acceleration of asthenospheric convection caused by periodic plume activity pulses can change spreading rates and, correspondingly, the relative positions of moving plates. The medium-scale periodicity of volcanism is illustrated by the examples of Kamchatka and Japan, where the intensity of subduction magmatism changes periodically in response to the opening of back-arc basins (Shikoku, Sea of Japan, and South Kurile basin).
DS202006-0946
2020
Dobretsov, N.L.Ponomarchuk, V.A., Dobretsov, N.L. , Lazareva, E.V., Zhmodik, S.M., Karmanov, N.S., Tolstov, A,V., Pyryaev, A.N.Evidence of microbial-induced mineralization in rocks of the Tomtor carbonatite complex ( Arctic Siberia).Doklady Earth Science, Vol. 490, 2, pp. 76-80.Russia, Siberiacarbonatite

Abstract: Carbonates of the Tomtor complex of ultramafic alkaline rocks and carbonatites (the northern part of the Republic of Sakha Yakutia) are distinguished by a wide range of carbon isotopic composition d13C from +2 to -59.9‰. The geological position, localization patterns, mineral and chemical compositions and the relationship with REE mineralization of samples with values of d13C carbonates from -25 to -59‰ are characterized. The formation of abnormally low d13C in carbonates is determined by the biogenic oxidation of methane from d13Cmet to -70‰.
DS1988-0176
1988
Dobretsova, L.V.Dobretsov, N.L., Dobretsova, L.V.New dat a on eclogites of CubaDoklady Academy of Science USSR, Earth Science Section, Vol. 292, No. 1-6, pp. 86-90GlobalEclogites
DS200812-0279
2008
Dobrinets, I.Deijanin, B., Simic, D., Zaitsev, A., Chapman, J., Dobrinets, I., Widemann, A., Del Re, N., Middleton, T., Dijanin, E., Se Stefano, A.Characterization of pink diamonds of different origin: natural ( Argyle, non-Argyle), irradiated and annealed, treated with multi-process, coated and synthetic.Diamond and Related Materials, Vol. 17, 7-10, pp. 1169-1178.AustraliaPink diamonds
DS201412-0196
2013
Dobrinets, I.A.Dobrinets, I.A., Vins, V.G., Zaitsev, A.M.HPHT-treated diamonds: diamonds forever.Springer, 257p. Approx $ 140.TechnologyBook
DS200512-0308
2005
Dobrolyubov, A.I.Gaetskii, R.C., Dobrolyubov, A.I.The tidal discrete wave mechanism of tectonic movements in the lithosphere.Doklady Earth Sciences, Vol. 400, 1, pp. 35-39.MantleTectonics
DS1995-0172
1995
Dobrozhev, L.F.Borisova, E.Y., Bibikova, E.V., Dobrozhev, L.F.The geochronological study of the granite gneiss zircon of the Kokchetav diamond bearing region. (Russian)Doklady Academy of Sciences Nauk., (Russian), Vol. 343, No. 6, Aug. pp. 801-5. #R2010RussiaGeochronology, Deposit -Kokchetav region
DS201412-0415
2014
Dobrrzhinetskaya, L.Jacob, D.E., Dobrrzhinetskaya, L., Wirth, R.New insight into polycrystalline diamond genesis from modern nanoanalytical techniques. Earth Science Reviews, Vol. 136, Sept. pp. 21-35.MantleDiamond, carbonado, UHP, subduction
DS2000-0502
2000
DobrtesovKirdyashkin, A.A., Dobrtesov, KirdyashinExperimental modeling of the influence of subduction zones on the spatial structure of lower mantle....Doklady Academy of Sciences, Vol. 371a, No. 3, Mar-Apr. pp. 565-8.MantleSubduction
DS1960-0655
1966
Dobrtetsov, N.L.Dobrtetsov, N.L., Khar'kiv, A.D., Shemyakin, M.L.The Use of Multi-dimensional Statistical Analysis for Solving Prognosis Problems Based on the Example of Diamond Occurrences in Kimberlites.Geologii i Geofiziki, No. 8, PP. 15-22.RussiaBlank
DS200412-0462
2002
Dobrush, T.Dobrush, T., Wilson, T.Core advantage... preserving and enhancing the value of exploration data.Mining Magazine, Vol. 188,3, March, pp. 124-5.TechnologyData management, information
DS1986-0187
1986
Dobryanskii, L.A.Dobryanskii, L.A., Kurilov, M.V., Boreiko, L.G., Zakharov, E.P.Characteristics of the distribution of trace elements in Rocks of the diamond bearing suite of the Chistyakovo Snezhnaya trough of the DonetsBasin.(Russian)Dopov. Akad. Nauk UKR. RSR Ser. B., Geokl. Khim. Biol., (Russian), No. 3, pp. 5-8RussiaBlank
DS1987-0388
1987
Dobryanskii, L.A.Kurilo, M.V., Dobryanskii, L.A.Geochemical anomalies in the suite of diamond bearing rocks Of the DonetsBasinDoklady Academy of Sciences Nauk SSR, Ser. B., (Russian), No. 4, pp. 13-16RussiaBlank
DS1987-0389
1987
Dobryanskiy, L.A.Kurilo, M.V., Dobryanskiy, L.A.Geochemical anomalies in the diamond suite of rocks of theDonetsBasin.(Russian)Dopov. Akad. Nauk UKR. Ser. B. (Russian), Vol. 1987, No. 4 April pp. 12-15RussiaDneiper-Donets Basin
DS1995-0427
1995
Dobrynina, M.I.Dobrynina, M.I.Kimberlites of the Arkhangelsk diamond province: review of theirstructural, petrophysical, geophysical aspectsSociety for Mining, Metallurgy and Exploration (SME) Meeting, Denver March 1995, abstractRussia, Commonwealth of Independent States (CIS), RussiaKimberlites
DS1995-0428
1995
Dobrynina, M.I.Dobrynina, M.I., Alexandrov, S.P., Garber, D.I.Kimberlites of the Arkhangelsk diamond province review of their structuralsetting, petrophysical characters.American Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint, No. 95-151, 6p.Russia, ArkangelskStructure, Deposit -Arkhangel
DS201112-1018
2011
Dobrzhinetskaya, I.F.Sumino, H., Dobrzhinetskaya, I.F., Burgess, R., Kagi, H.Deep mantle derived noble gases in metamorphic diamonds from the Kokchetav massif, Kazakhstan.Earth and Planetary Science Letters, Vol. 307, 3-4, pp. 439-449.Russia, KazakhstanMicrodiamonds - SCLM, metasomatism, subduction
DS1996-0370
1996
Dobrzhinetskaya, L.Dobrzhinetskaya, L., Green, H.W. II, Wang, S.Alpe Arami: a peridotite Massif from depths of more than 300 kilometersScience, Vol. 271, March 29, pp. 1841-45.GlobalPeridotite massif, Mantle
DS1999-0170
1999
Dobrzhinetskaya, L.Dobrzhinetskaya, L., Bpzilov, K.N., Green, H.W.The solubility of TiO2 in olivine: implications for the mantle wedgeenvironment.Chemical Geology, Vol. 160, No. 4, Sept. 2, pp. 357-70.MantleMineral chemistry - olivine
DS2000-0626
2000
Dobrzhinetskaya, L.Massone, H.J., Dobrzhinetskaya, L., Green, H.W.Quartz Potassium feldspar intergrowths enclosed in eclogitic garnet and omphacite. are pseudomorphs after coesite?Igc 30th. Brasil, Aug. abstract only 4p.Globalmetamorphism, Dabie Shan
DS200712-0254
2007
Dobrzhinetskaya, L.Dobrzhinetskaya, L., Liu, Z., Green, H.W.Synchrotron infrared spectroscopy: confirmation of metamorphic diamond crystallization from C-O-H fluid. ( Erzgebirge region).Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p.149.Europe, GermanyDiamond genesis
DS200712-0255
2007
Dobrzhinetskaya, L.Dobrzhinetskaya, L., Liu, Z., Green, H.W.Synchrotron infrared spectroscopy: confirmation of metamorphic diamond crystallization from C-O-H fluid. ( Erzgebirge region).Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p.149.Europe, GermanyDiamond genesis
DS200712-0256
2007
Dobrzhinetskaya, L.Dobrzhinetskaya, L., Takahata, N., Sano, Y., Green, H.W.Fluid organic matter interaction at high pressure and temperature: evidence from metamorphic diamonds.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p. 279.Russia, Kazakhstan, Europe, GermanyKokchetav and Erzgebirge
DS200712-0257
2007
Dobrzhinetskaya, L.Dobrzhinetskaya, L., Takahata, N., Sano, Y., Green, H.W.Fluid organic matter interaction at high pressure and temperature: evidence from metamorphic diamonds.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p. 279.Russia, Kazakhstan, Europe, GermanyKokchetav and Erzgebirge
DS200712-1198
2007
Dobrzhinetskaya, L.Yang, J-S., Dobrzhinetskaya, L.Diamond and coesite bearing chromitites from the Luobusa ophiolite, Tibet.Geology, Vol. 35, 10, Oct. pp. 875-878.Asia, TibetUHP
DS200812-0287
2007
Dobrzhinetskaya, L.Dobrzhinetskaya, L.Ultrahigh pressure metamorphic fluid: evidence from subduction zone microdiamonds.Geological Society of America Annual Meeting 2007, Denver Oct. 28, 1p. AbstractMantle, Russia, Kazakhstan, Europe, GermanyUHP
DS200812-0288
2008
Dobrzhinetskaya, L.Dobrzhinetskaya, L., Wirth, R.Fluids role in formation of microdiamonds from ultrahigh pressure metamorphic terranes.Goldschmidt Conference 2008, Abstract p.A221.Russia, Europe, GermanyMicrodiamonds
DS200912-0177
2008
Dobrzhinetskaya, L.Dobrzhinetskaya, L., Wirth, R., Yang, J., Green, H.W.Nontraditional 'deliverers' of UHP rocks from Earth's deep interior to surface.American Geological Union, Fall meeting Dec. 15-19, Eos Trans. Vol. 89, no. 53, meeting supplement, 1p. abstractMantleUHP
DS201012-0770
2010
Dobrzhinetskaya, L.Sumino, H., Dobrzhinetskaya, L.Deep mantle derived noble gases in metamorphic microdiamonds from the Kokchetav Massif, Kazakhstan.Goldschmidt 2010 abstracts, abstractRussiaMicrodiamonds
DS201012-0853
2010
Dobrzhinetskaya, L.Wirth, R., Dobrzhinetskaya, L., Harte, B., Green, H.W.Tubular Mg ferrite in magnesiowustite inclusions in diamond from superdeep origin: control of Fe valence by dislocation core structure.International Mineralogical Association meeting August Budapest, abstract p. 210.South America, BrazilPetrology
DS201112-0279
2011
Dobrzhinetskaya, L.Dobrzhinetskaya, L., Wirth, R., Green, H.W., Sumino, H.Fluids nature at peak of ultrahigh pressure metamorphism in deep subduction zones - evidence from diamonds.Goldschmidt Conference 2011, abstract p.769.Russia, Kazakhstan, Europe, GermanyUHP - Kokchetav
DS201312-0218
2013
Dobrzhinetskaya, L.Dobrzhinetskaya, L., Faryad, S.W., Hoinkes, G.Mineral transformations in HP-UHP metamorphic terranes.Journal of Metamorphic Geology, Vol. 31, 1, pp. 3-4.MantleUHP
DS201312-0219
2013
Dobrzhinetskaya, L.Dobrzhinetskaya, L., Wirth, R., Green, H.W., Schreiber, A., O'Bannon, E.First find of polycrystalline diamond in ultrahigh pressure metamorphic terrane of Erzgebirge Germany.Journal of Metamorphic Geology, Vol. 31, pp. 5-18.Europe, GermanyUHP
DS201312-0260
2012
Dobrzhinetskaya, L.Faryad, S.W., Dobrzhinetskaya, L., Hoinkes, G., Zhang, J.Ultrahigh pressure and high-pressure metamorphic terrances in orogenic belts: reactions, fluids and geological processes.Gondwana Research, Vol. 23, 4, pp. 841-MantleUHP
DS201412-0197
2014
Dobrzhinetskaya, L.Dobrzhinetskaya, L., Wirth, R., Green, H.Diamonds in Earth's oldest zircons from Jack Hills conglomerate, Australia, are contamination.Earth and Planetary Science Letters, Vol. 387, pp. 212-218.AustraliaDiamond inclusions
DS201412-0985
2014
Dobrzhinetskaya, L.Wirth, R., Dobrzhinetskaya, L., Harte, B., Schreiber, A., Green, H.W.High-Fe (Mg,Fe)O inclusion in diamond apparently from the lowermost mantle.Earth and Planetary Science Letters, Vol. 404, Oct. pp. 365-375.MantleDiamond inclusions
DS201805-0943
2018
Dobrzhinetskaya, L.Dobrzhinetskaya, L., Mukhin, P., wang, Q., Wirth, R., O'Bannon, E., Zhao, W., Eppelbaum, L., Sokhonchuk, T.Moissanite ( SiC) with metal silicide and silicon inclusions from tuff of Israel: raman spectroscopy and electron microscope studies.Lithos, in press available 58p.Europe, Israelmoissanite

Abstract: Here, we present studies of natural SiC that occurs in situ in tuff related to the Miocene alkaline basalt formation deposited in northern part of Israel. Raman spectroscopy, SEM and FIB-assisted TEM studies revealed that SiC is primarily hexagonal polytypes 4H-SiC and 6H-SiC, and that the 4H-SiC polytype is the predominant phase. Both SiC polytypes contain crystalline inclusions of silicon (Sio) and inclusions of metal-silicide with varying compositions (e.g. Si58V25Ti12Cr3Fe2, Si41Fe24Ti20Ni7V5Zr3, and Si43Fe40Ni17). The silicides crystal structure parameters match Si2TiV5 (Pm-3 m space group, cubic), FeSi2Ti (Pbam space group, orthorhombic), and FeSi2 (Cmca space group, orthorhombic) respectively. We hypothesize that SiC was formed in a local ultra-reduced environment at respectively shallow depths (60-100 km), through a "desilification" reaction of SiO2 with highly reducing fluids (H2O-CH4-H2-C2H6) arisen from the mantle "hot spot" and passing through alkaline basalt magma reservoir. SiO2 (melt) interacting with the fluids may originate from the walls of the crustal rocks surrounding this magmatic reservoir. The "desilification" process led to the formation of SiC and the reduction of metal-oxides to native metals, alloys, and silicides. The latter were trapped by SiC during its growth. Hence, interplate "hot spot" alkali basalt volcanism can now be included as a geological environment where SiC, silicon, and silicides can be found.
DS201808-1766
2018
Dobrzhinetskaya, L.Machev, P., O'Bannon, E.F., Bozhilov, K.N., Wang, Q., Dobrzhinetskaya, L.Not all moissanites are created equal: new constraints on moissanite from metamorphic rocks of Bulgaria. Earth and Planetary Science Letters, Vol. 498, pp. 387-396.Europe, Bulgariamoissanite

Abstract: Terrestrial moissanite (SiC) is widely reported as an ultra-high pressure mineral occurring in kimberlites, diamonds and ultramafic/mafic rocks of mantle origin. However, the conditions of crystallization remain largely unknown. Moreover, dozens of SiC occurrences have been reported from continental crust sources such as granitoids, andesite-dacite volcanic rocks and their breccia, metasomatic and metamorphic rocks, and even limestones. The validity of many of these reports is still debated primarily due to possible contaminations from the widespread use of synthetic SiC abrasives in samples preparation. Indeed, reports of well-documented in-situ occurrences of moissanite in association with co-existing minerals are still scarce. The only condition of moissanite formation that is agreed upon is that extremely reducing media are required (e.g. 4.5-6 log units below the iron-wustite buffer). Here, we report the new occurrence of moissanite that was found in-situ within the garnet-staurolite-mica schists of Topolovgrad metamorphic group of Triassic age in Southern Bulgaria. The 10-300 µm moissanite crystals are situated within 0.1-1.2 mm isolated clusters, filled with amorphous carbon and nanocrystalline graphite. Most of moissanite crystals are 15R (rhombohedral) and 6H (hexagonal) polytypes, and one prismatic crystal, found within them, exhibits unusual concentric polytypical zoning with core (15R), intermediate zone (6H) and rim (3C-cubic). Experimental data show that this type of polytypical zonation is likely due to a decrease in temperature (or/and pressure?) and changes in Si/C ratio. Indeed, amphibolite facies metamorphism (500-580?°C - garnet-staurolite zone) followed by a subsequent cooling during the retrograde stage of green schist facies metamorphism (~400-500?°C) could have provided a change in temperature. The SiC containing clusters exhibit evidence that they are pre-metamorphic, and we hypothesize that their protolith was a "lack shale" material likely rich in carbon, hydrocarbon and terrigenous silica. The latter served as a source of isolated chemically-reduced media, which is required for SiC formation. Other concepts to explain moissanite occurrences in metasedimentary rocks are also discussed. Importantly, our findings show that the formation conditions of moissanite are likely more variable than previously recognized.
DS202004-0535
2020
Dobrzhinetskaya, L.Stan, C.V., O'Bannon III, E.F., Mukhin, P., Tamura, N., Dobrzhinetskaya, L.X-ray laue microdiffraction and raman spectroscopic investigation of natural silicon and moissanite.Minerals MDPI, Vol. 10, 10030204 12p. PdfGlobalmoissanite

Abstract: Moissanite, SiC, is an uncommon accessory mineral that forms under low oxygen fugacity. Here, we analyze natural SiC from a Miocene tuff-sandstone using synchrotron Laue microdiffraction and Raman spectroscopy, in order to better understand the SiC phases and formation physics. The studied crystals of SiC consist of 4H- and 6H-SiC domains, formed from either, continuous growth or, in one case, intergrown, together with native Si. The native Si is polycrystalline, with a large crystal size relative to the analytical beam dimensions (>1-2 µm). We find that the intergrown region shows low distortion or dislocation density in SiC, but these features are comparatively high in Si. The distortion/deformation observed in Si may have been caused by a mismatch in the coefficients of thermal expansion of the two materials. Raman spectroscopic measurements are discussed in combination with our Laue microdiffraction results. Our results suggest that these SiC grains likely grew from an igneous melt.
DS202006-0944
2020
Dobrzhinetskaya, L.O'Bannon, E., Xia, G., Shi, F., Wirth, R., King, R.A., Dobrzhinetskaya, L.The transformation of diamond to graphite: experiments reveal the presence of an intermediate linear carbon phase. Diamonds & Related Materials, in press available, 31p. PdfGlobalcarbon

Abstract: Natural diamonds that have been partially replaced by graphite have been observed to occur in natural rocks. While the graphite-to-diamond phase transition has been extensively studied the opposite of this (diamond to graphite) remains poorly understood. We performed high-pressure and temperature hydrous and anhydrous experiments up to 1.0?GPa and 1300?°C using Amplex premium virgin synthetic diamonds (20-40?µm size) as the starting material mixed with Mg (OH)2 as a source of H2O for the hydrous experiments. The experiments revealed that the diamond-to-graphite transformation at P?=?1GPa and T?=?1300?°C was triggered by the presence of H2O and was accomplished through a three-stage process. Stage 1: diamond reacts with a supercritical H2O producing an intermediate 200-500?nm size “globular carbon” phase. This phase is a linear carbon chain; i.e. a polyyne or carbyne. Stage 2: the linear carbon chains are unstable and highly reactive, and they decompose by zigzagging and cross-linking to form sp2-bonded structures. Stage 3: normal, disordered, and onion-like graphite is produced by the decomposition of the sp-hybridized carbon chains which are re-organized into sp2 bonds. Our experiments show that there is no direct transformation from sp3 C-bonds into sp2 C-bonds. Our hydrous high-pressure and high-temperature experiments show that the diamond-to-graphite transformation requires an intermediate metastable phase of a linear hydrocarbon. This process provides a simple mechanism for the substitution of other elements into the graphite structure (e.g. H, S, O).
DS1994-0436
1994
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F.rare earth elements (REE); patterns for protolith of metamorphic rocks from the Kokchetav diamond province of Kazakhstan -tectonicsEos, Annual Meeting November 1, Vol. 75, No. 44, p.701. abstractRussia, Commonwealth of Independent States (CIS), KazakhstanGeochronology, Metamorphic rocks
DS1994-0437
1994
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Braun, I.V., Sheskel, G.G., Podkuiko, Y.A.Geology and structure of diamond bearing rocks of the Kokchetav Massif, Kazahkstan.Tectonophysics, Vol. 233, No. 3-4, May 30, pp. 293-313.Russia, KazahkstanStructure, Diamondiferous rocks
DS1995-0429
1995
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Eide, E.A., et al.Microdiamond in high grade metamorphic rocks of the western gneiss Norway.Geology, Vol. 23, No. 7, July pp. 597-600.NorwayMicrodiamonds, Spectrometry
DS1995-1059
1995
Dobrzhinetskaya, L.F.Larsen, R., Burke, E.A.J., Dobrzhinetskaya, L.F., et al.N2 CO2 CH2 H2O metamorphic fluids in microdiamond bearing lithologies From the western gneiss region.Ngu (norges Geol. Undersoklse, Bulletin., No. 427, pp. 41-43.NorwayDiamonds
DS2001-0263
2001
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Green, H., Mitchell, T., DickersonMetamorphic diamonds: mechanisms of growth and inclusion of oxideGeology, Vol. 29, No. 3, Mar. pp. 263-6.GlobalDiamond inclusions, morphology, Deposit - Kokchetav Massif
DS2003-0339
2003
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Green, H.W., Bozhilov, K.N., Mitchell, T.E., Dickerson, R.M.Crystallization environment of Kazakhstan microdiamond: evidence from nanometricJournal of Metamorphic Geology, Vol. 21, 5, pp. 425-38.Russia, KazakhstanMineral inclusions
DS2003-0340
2003
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Green, H.W., Weschler, M., Darus, M., Wang, Y.C.Focused ion beam technique and transmission electron microscope studies ofEarth and Planetary Science Letters, Vol. 210, 3-4, pp. 399-410.GermanyTechnology
DS2003-0341
2003
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Green, H.W., Weschler, M., Darus, M., Young-ChungFocused ion beam technique and transmission electron microscope studies ofEarth and Planetary Science Letters, Vol. 210, 3-4, May 30, pp.399-410.GermanyDiamond inclusions
DS200412-0463
2003
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Green, H.W., Bozhilov, K.N., Mitchell, T.E., Dickerson, R.M.Crystallization environment of Kazakhstan microdiamond: evidence from nanometric inclusions and mineral associations.Journal of Metamorphic Geology, Vol. 21, 5, pp. 425-38.Russia, KazakhstanMicrodiamonds, mineral inclusions
DS200412-0464
2003
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Green, H.W., Weschler, M., Darus, M., Young-Chung, Wang, Massone, H-J., Stockhert, B.Focused ion beam technique and transmission electron microscope studies of microdiamonds from the Saxonian Erzgerbirge, Germany.Earth and Planetary Science Letters, Vol. 210, 3-4, May 30, pp.399-410.Europe, GermanyDiamond inclusions
DS200412-2169
2003
Dobrzhinetskaya, L.F.Yang, J., Xu, Z., Dobrzhinetskaya, L.F., Green, H.W., Pei, X., Shi, R., Wu, C., Wooden, J.L., Zhang, J., WanDiscovery of metamorphic diamonds in central China: an indication of a > 4000 km long zone of deep subduction resulting from mulTerra Nova, Vol. 15, pp. 370-379.ChinaSubduction, Central Orogenic Belt, UHP
DS200512-0238
2004
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Green, H.W., Renfro, A.P., Bozhilov, K.N., Spengler, D., Van Roemund, H.L.M.Precipitation of pyroxenes and Mg2SiO4 from majorite garnet: simulation of peridotite exhumation from great depth.Terra Nova, Vol. 16, 6, pp. 325-330.MantlePetrology - peridotite
DS200512-0239
2004
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Renfro, A.P., Green, H.W.II.Synthesis of skeletal diamonds: implications for microdiamond formation in orogenic belts.Geology, Vol. 32, 10, Oct. pp. 869-872.KazakhstanUHP, C-O-H fluid, Kokchetav massif
DS200512-0240
2005
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Wirth, R., Green, H.W.Direct observation and analysis of a trapped COH fluid growth medium in metamorphic diamond.Terra Nova, Vol. 17, 5, Oct. pp. 472-477.KazakhstanDiamond morphology, metamorphic, UHP Kokchetav Massif
DS200612-0338
2006
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., liu, Z., Cartigny, P., Zhang, J., Tchkhetia, D., Hemley, R.J., Green II, H.W.Synchrotron infrared and Raman spectroscopy of microdiamonds from Erzgebirge, Germany.Earth and Planetary Science Letters, Vol. 248, 1-2, Aug. 15, pp. 325-334.Europe, GermanyMicrodiamonds
DS200612-0339
2005
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Wirth, R., Green, H.W.Direct observation and analysis of a trapped COH fluid growth medium in metamorphic diamond.Terra Nova, Vol. 17, 5, pp. 472-477.MantleUHP
DS200612-0340
2006
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Wirth, R., Green, H.W.II.Nanometric inclusions of carbonates in Kokchetav diamonds from Kazakhstan: a new constraint for the depth of metamorphic diamond crystallization.Earth and Planetary Science Letters, Vol. 243, 1-2, Mar. 15, pp. 85-93.Russia, KazakhstanDiamond morphology, metamorphism
DS200712-0258
2007
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Green, H.W.Diamond synthesis from graphite in the presence of water and SiO2: implications for diamond formation in quartzites from Kazakhstan.International Geology Review, Vol. 49, 5, pp. 389-400.Russia, KazakhstanDiamond genesis
DS200712-0259
2007
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Green, H.W.Experimental studies of mineralogical assemblages of metasedimentary rocks at Earth's mantle transition zone conditions.Journal of Metamorphic Geology, Vol. 25, 2, pp. 83-96.MantleMineralogy
DS200712-0260
2007
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Wirth, R., Green, H.W.A look inside of diamond forming media in deep subduction zones.Proceedings of National Academy of Sciences USA, Vol. 104, 22, pp. 9128-9132. IngentaMantleSubduction
DS200812-0289
2008
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Brueckner, H.K., Cuthbert, S.I.Ultrahigh pressure metamorphism: from Earth's interior to mountain buildings.Lithos, In press available 20p.MantleUHP
DS200912-0078
2009
Dobrzhinetskaya, L.F.Bruce, L.F., Kopylova, M.G., Longo, M., Ryder, J., Dobrzhinetskaya, L.F.Cathodluminescence of diamonds in metamorphic rocks.37th. Annual Yellowknife Geoscience Forum, Abstracts p. 4-5.TechnologyCL
DS200912-0178
2009
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F.New geological settings for ultrahigh pressure rocks.GAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyMantleUHP
DS200912-0179
2009
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Wirth, R., Green, H.Lamellae of phylosilicates in K rich diopside from UHP marble of the Kokchetav massif, Kazakhstan: FIB-TEM and synchrotron IR studies.Goldschmidt Conference 2009, p. A296 Abstract.RussiaUHPM - diamond inclusions
DS200912-0180
2009
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Wirth, R., Rhede, D., Liu, Z., Green, H.W.Phlogopite and quartz lamellae in diamond bearing diopside from marbles of the Kokchetav massif, Kazakhstan: exsolution or replacement reaction?Journal of Metamorphic Geology, Vol. 27, 9, pp. 607-620.Russia, KazakhstanDeposit - Kokchetav
DS200912-0740
2009
Dobrzhinetskaya, L.F.Sumino, H., Dobrzhinetskaya, L.F.Noble gases in metamorphic diamonds from Kokchetav Massif, Kazakhstan, revisited.Goldschmidt Conference 2009, p. A1291 Abstract.Russia, KazakhstanMicrodiamonds
DS201012-0160
2009
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Wirth, R.Ultradeep rocks and diamonds in the light of advanced scientific technologies.International Year of Planet Earth, New Frontiers in Integrated Solid Earth Sciences, Available at cost? Springerlink Book ChapterTechnologyReview
DS201012-0161
2010
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Wirth, R., Rhede, D.Phlogopite and quartz lamellae in diamond bearing diopside from marbles of the Kochetav Massif, Kazakhstan, exsolution or replacement reaction.Journal of Metamorphic Geology, Vol. 27, 9, pp. 607-620.Russia, KazakhstanKochetav area
DS201012-0643
2010
Dobrzhinetskaya, L.F.Ruskov, T., Spirov, I., Georgieva, M., Yamamoto, S., Green, H.W., McCammon, C.A., Dobrzhinetskaya, L.F.Mossbauer spectroscopy studies of the valence state of iron in chromite from the Luobusa Massif of Tibet: implications for a highly reduced mantle.Journal of Metamorphic Geology, Vol. 28, 5, pp. 551-560.Asia, TibetMetasomatism
DS201112-0121
2011
Dobrzhinetskaya, L.F.Bruce, L.F., Kopylova, M.G., Longo, M., Ryder, J., Dobrzhinetskaya, L.F.Luminescence of diamonds from metamorphic rocks.American Mineralogist, Vol. 96, 1, pp. 14-22.Canada, Ontario, Wawa, Russia, GermanyUHP, cathodluminescence
DS201112-1161
2011
Dobrzhinetskaya, L.F.Zhang, J.F., Xu, H.J., Liu, Q., Green, H.W., Dobrzhinetskaya, L.F.Pyroxene exsolution topotaxy in majoritic garnet from 250 to 300 km depth.Journal of Metamorphic Geology, Vol. 29, 7, pp. 741-751.TechnologyGarnet mineralogy
DS201112-1162
2011
Dobrzhinetskaya, L.F.Zhang, J.F., Xu, H.J., Liu, Q., Green, H.W., Dobrzhinetskaya, L.F.Pyroxene evolution topotaxy in majorite garnet from 250 to 300 km depth.Journal of Metamorphic Geology, In press available,MantleGarnet
DS201201-0840
2012
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F.Microdiamonds - frontier of ultrahigh-pressure metamorphism: a review.Gondwana Research, Vol. 21, 1, pp. 207-233.MantleMicrodiamonds -UHP
DS201212-0163
2013
Dobrzhinetskaya, L.F.Dobrzhinetskaya, L.F., Wirth, R., Green, H.W., Schreiber, A., O'Bannon, E.First find of polycrystalline diamond in ultrahigh-pressure metamorphic terrane of Erzgebirge, Germany.Journal of Metamorphic Geology, Vol. 31, 1, pp. 5-18.Europe, GermanyUHP
DS201611-2126
2016
Dobrzhinetskaya, L.F.Nasdala, L., Dobrzhinetskaya, L.F., Korsakov, A.V., Massone, J-J., Reissner, C.UHP phases versus preparation materials - be cautious when using micro-raman spectroscopy.European Mineralogical Conference held Sept. 11-15, Italy, p. 219. abstract 1p.TechnologyRaman Spectroscopy
DS201705-0824
2017
Dobrzhinetskaya, L.F.Dobrzhinetskaya,L.F., Mukhin, P., Wang, Q., Sokhonchuk, T.Moissanite ( SiC) with metal-silicide and silicon inclusions from tuff of Israel: Raman spectroscopy and electron microscopy studies.Lithos, Vol. 282, pp. 1-11.Asia, IsraelMoissanite

Abstract: Here, we present studies of natural SiC that occurs in situ in tuff related to the Miocene alkaline basalt formation deposited in northern part of Israel. Raman spectroscopy, SEM and FIB-assisted TEM studies revealed that SiC is primarily hexagonal polytypes 4H-SiC and 6H-SiC, and that the 4H-SiC polytype is the predominant phase. Both SiC polytypes contain crystalline inclusions of silicon (Sio) and inclusions of metal-silicide with varying compositions (e.g. Si58V25Ti12Cr3Fe2, Si41Fe24Ti20Ni7V5Zr3, and Si43Fe40Ni17). The silicides crystal structure parameters match Si2TiV5 (Pm-3 m space group, cubic), FeSi2Ti (Pbam space group, orthorhombic), and FeSi2 (Cmca space group, orthorhombic) respectively. We hypothesize that SiC was formed in a local ultra-reduced environment at respectively shallow depths (60-100 km), through a “desilification” reaction of SiO2 with highly reducing fluids (H2O-CH4-H2-C2H6) arisen from the mantle “hot spot” and passing through alkaline basalt magma reservoir. SiO2 (melt) interacting with the fluids may originate from the walls of the crustal rocks surrounding this magmatic reservoir. The “desilification” process led to the formation of SiC and the reduction of metal-oxides to native metals, alloys, and silicides. The latter were trapped by SiC during its growth. Hence, interplate “hot spot” alkali basalt volcanism can now be included as a geological environment where SiC, silicon, and silicides can be found.
DS201808-1790
2017
Dobrzhinetskaya, L.F.Stan, C.V., Obannon, E.F., Dobrzhinetskaya, L.F., Tamura, N.Polytypism in natural SiC using Laue microdiffraction.Acta Crystallographia, A70, 1p. abstractEurope, Israelmoissanite

Abstract: Silicon carbide (SiC, moissanite) is a common industrial material that is rarely found in terrestrial rocks and meteorites. It has been found to adopt over 300 different crystal structures, most of which are polytypic: they consist of alternating layers of Si and C, with only small stacking faults or shears distinguishing them from one another. In nature, only a few polytypes of SiC have been found, primarily a cubic zincblende type (3C-SiC), several hexagonal wurtzite types (4H-SiC and 6H-SiC), and a rhombohedral type (15R-SiC). Our natural silicon carbide sample is from a Miocene tuff (Yizre’el Valley, Israel) related to interplate alkaline basalt volcanism. Three SiC grains with native silicon and metal silicide inclusions were analyzed using Raman spectroscopy and synchrotron Laue X-ray microdiffraction accompanied by mapping at a 5-8 um resolution. SiC is found to crystallize in only the 4H and 6H polytypes. Due to the crystal orientation of the grains, as well as the significant difference in the c-axis length (~10 vs. ~15 um in 4H and 6H respectively), we were able to unambiguously assign polytypes to each diffraction pattern. Each grain contains large areas where one polytype dominates as a single crystal. In some cases, multiple stacking faults and misoriented polycrystalline aggregates of SiC occur at the 4H/6H interface. In other cases we see intercalation of the 4H and 6H crystals throughout the diffracting volume without a significant change in their crystallographic axes orientation, pointing to a possibly incommensurate crystal structure. Stress and strain are also mapped for all three grains, showing a slight (< 2 ppt) compressive strain in the y direction of all three grains, and a tensile strain in the x and z directions. In the SiC-2 grain, a mostly single-crystalline Si inclusion was found, with an exposed surface diameter of ~30 um. We examine residual strain in Si by both Laue X-ray diffraction and Raman spectroscopy, and find results to generally agree between the two measurements.
DS1995-1512
1995
DobrzhinnetskayaPosukhova, L.F., Dobrzhinnetskaya, Nadezhdina, ShadrinaMorphology and growth conditions of diamonds in metamorphic rocksProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 452-454.Russia, Kazakhstan, ChinaMetamorphic, Diamond genesis
DS201212-0164
2012
Dobrzhinskaya, L.F.Dobrzhinskaya, L.F., Wirth, R., Green, H.W., Schreiber, A., O'bannon, E.First find of polycrystalline diamond in ultrahigh pressure metamorphic terrane of Erzgebirge Germany.Journal of Metamorphic Geology, in press availableEurope, GermanyUHP
DS201809-2102
2018
Dobsdon, D.P.Thomson, A.R., Dobsdon, D.P., Brodhollt, J., Crichton, W., Cerantola, V., Piltz, R.Crystallographic in corporation of hydrogen in ringwoodite.Goldschmidt Conference, 1p. AbstractMantlewater

Abstract: The transition zone (TZ) is believed to be the primary destination of subducted water [1], with the main TZ minerals (wadsleyite and ringwoodite) capable of holding up to ~ 3 wt.% H2O in their structures’. Observations of high attenuation and elevated conductivity suggest some areas of the transition zone are hydrated [2,3]. Combined with the observation of ~ 1.4 wt% H2O in a diamond-hosted ringwoodite inclusion [4], it is probable that the transition zone is at least regionally, if not globally, “wet”. The presence of water can induce partial melting, alter chemical partitioning and drastically change the strength of rocks. The detailed effect of water’s presence in the TZ will strongly depend on hydrogen’s incorporation mechanism, i.e. exchange with Si4+, Mg2+, Fe2+ cations or coupled substitution with Fe3+ in ringwoodite. Recent developments in neutron single-crystal Laue diffraction now allow measurements on crystals smaller than 0.1 mm3 [5]. Here we quantitatively study the incorporation of hydrogen in a synthetic iron-bearing ringwoodite. A multi-technique approach, with independent determination of chemistry, ferric iron content, water content and structure via x-ray and neutron diffraction allows a detailed study of the hydrous ringwoodite structure and the incorporation mechanism of water throughout Earth’s TZ.
DS1995-0893
1995
Dobson, D.Jones, A.P., Taniguchi, T., Dobson, D., Milledge, H.J.Experimental nucleation and growth of diamond from carbonate graphitesystems.Geological Society Africa 10th. Conference Oct. Nairobi, p. 119. Abstract.GlobalPetrology -experimental, Diamond
DS1995-0894
1995
Dobson, D.Jones, A.P., Taniguchi, T., Dobson, D., Rabe, R., MilledgeExperimental nucleation and growth of diamond from carbonate-graphitesystems.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 269-270.GlobalPetrology -experimental, Diamond nucleation
DS1998-0167
1998
Dobson, D.Brodholt, J.P., Dobson, D.Electrical conductivity of mantle minerals and the temperature of theEarth's lower mantle.Ima 17th. Abstract Vol., p. A 36, abstractMantleGeothermometry
DS1998-0703
1998
Dobson, D.Jones, A.P., Dobson, D., Milledge, Tabiguchi, LitvinExperiments with low T potassic carbonatitic melts, fluids and diamonds7th International Kimberlite Conference Abstract, pp. 386-8.GlobalCarbonatite, Petrology - experimental
DS2003-0354
2003
Dobson, D.Dubrovinsky, L., Dubrovinskaia, N., Langenhorst, F., Dobson, D., Robie, D.Iron silica interaction at extreme conditions and the electrically conducting layer at theNature, No. 6927, March 6, pp. 58-60.MantleCore mantle boundary, Geochemistry
DS200912-0076
2009
Dobson, D.Brodholt, J., Amman, M., Hunt, S., Walker, S., Dobson, D.The rheological properties of post-perovskite and implications for D'.Goldschmidt Conference 2009, p. A162 Abstract.MantleBoundary
DS201212-0165
2012
Dobson, D.Dobson, D., Ammann, M., Tackley, P.The grain size of the lower mantle.emc2012 @ uni-frankfurt.de, 1p. AbstractMantleConvection
DS201312-0946
2013
Dobson, D.Walker, A.M., Ammann, M.W., Stackhouse, S., Wookey, J., Bordholdt, J.P., Dobson, D.Anisotropy: a cause of heat flux variation at the CMB?Goldschmidt 2013, 1p. AbstractMantlePerovskite
DS201611-2116
2016
Dobson, D.Jones, A.P., McMillan, P.F., Salzmann, C.G., Alvaro, M., Nestola, F., Prencipe, M., Dobson, D., Hazael, R., Moore, M.Structural characteristization of natural diamond shocked to 60 Gpa: implications for Earth and Planetary Systems.Lithos, in press available 25p.TechnologyNatural diamonds

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

Abstract: The possible presence of the high-density carbon polymorph with hexagonal symmetry known as “lonsdaleite” provides an important marker for shock impact events. It is typically considered to form as a metastable phase produced from graphite or other carbonaceous precursors. However, its existence has recently been called into question. Here we collected high-resolution synchrotron X-ray diffraction data for laboratory-shocked and natural impact diamonds that both show evidence for deviations from cubic symmetry, that would be consistent with the appearance of hexagonal stacking sequences. These results show that hexagonality can be achieved by shocking diamond as well as from graphite precursors. The diffraction results are analyzed in terms of a general model that describes intermediate stacking sequences between pure diamond (fully cubic) and “lonsdaleite” (fully hexagonal) phases, with provision made for ordered vs disordered stacking arrangements. This approach provides a “hexagonality index” that can be used to characterize and distinguish among samples that have experienced different degrees of shock or static high pressure-high temperature treatments. We have also examined the relative energetics of diamond and “lonsdaleite” structures using density functional theoretical (DFT) methods. The results set limits on the conditions under which a transformation between diamond and “lonsdaleite” structures can be achieved. Calculated Raman spectra provide an indicator for the presence of extended hexagonal stacking sequences within natural and laboratory-prepared samples. Our results show that comparable crystallographic structures may be developed by impact-generated shockwaves starting from ambient conditions using either of the two different allotropes of carbon (diamond, graphite). This broadens the scope for its occurrence in terrestrial and planetary systems.
DS1982-0178
1982
Dobson, D.C.Dobson, D.C.Geology and Alteration of the Lost River Tin Tungsten Fluorine Deposit, alaskaEconomic Geology, Vol. 77, No. 4, PP. 1033- 1052.GlobalSkarn, Greisen, Breccia, Stockwork, York Mountain, Seward, Mines
DS1995-0892
1995
Dobson, D.P.Jones, A.P., Dobson, D.P., Genge, M.Comment on physical properties of carbonatite magmas inferred from molten salt data, mantle chambers....Geological Magazine, Vol. 132, No. 1, p. 121.GlobalMagma, Carbonatite -silicate
DS2000-0239
2000
Dobson, D.P.Dobson, D.P., Brodholt, J.P.The electrical conductivity and thermal profile of the Earth's Mid-MantleGeophysical Research Letters, Vol. 27, No. 15, Aug. 1, pp. 2325-28.MantleGeothermometry
DS200612-0605
2006
Dobson, D.P.Howell, D., Jones, A.P., Dobson, D.P., Milledge, H.J., Harris, J.W.Birefringence analysis of diamond utilising the MetriPol system.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 268. abstract only.TechnologyDiamond morphology
DS201012-0292
2010
Dobson, D.P.Howell, D., Wood, I.G., Dobson, D.P., Jones, A.P., Nasdala, L., Harris, J.W.Quantifying strain birefringence halos around inclusions in diamond.Contributions to Mineralogy and Petrology, Vol. 160, pp. 705-717.TechnologyDiamond genesis, inclusion remnant pressure
DS201212-0311
2012
Dobson, D.P.Howell, D., Piazolo, S., Dobson, D.P., Wood, I.G., Jones, A.P., Watte, N., Frost, D.J., Fisher, D., Griffin, W.L.Quantitative characterization of plastic deformation of single diamond crystals: a high pressure high temperature (HPHT) experimental deformation study combines with electron backscatter diffraction.Diamond and Related Materials, Vol. 30, pp. 20-30.TechnologyDiamond morphology
DS201212-0322
2012
Dobson, D.P.Hunt, S.A., Davies, D.R., Walker, A.M., McCormack, R.J., Wills, A.S., Dobson, D.P., Li, Li.On the increase in thermal diffusivity caused by the perovskite to post-perovskite phase transition and its implications for mantle dynamics.Earth and Planetary Science Letters, Vol. 319-320, pp. 96-103.MantleGeodynamics
DS201412-0198
2014
Dobson, D.P.Dobson, D.P., Mariani, E.The kinetics of the reaction of majorite plus ferropericlase to ringwoodite: implications for mantle upwellings crossing the 660 km discontinuity.Earth and Planetary Science Letters, Vol. 408, pp. 110-118.MantleRingwoodite
DS201909-2096
2019
Dobson, D.P.Thomson, A.R., Crichton, W.A., Brodholt, J.P., Wood, I.G., Siersch, N.C., Muir, J.M.R., Dobson, D.P., Hunt, S.A..Seismic velocities of CaSiO3 perovskite can explain LLSVPs in Earth's lower mantle.Nature, Vol. 572, 7769, 18p. PdfMantleperovskite

Abstract: Seismology records the presence of various heterogeneities throughout the lower mantle1,2, but the origins of these signals—whether thermal or chemical—remain uncertain, and therefore much of the information that they hold about the nature of the deep Earth is obscured. Accurate interpretation of observed seismic velocities requires knowledge of the seismic properties of all of Earth’s possible mineral components. Calcium silicate (CaSiO3) perovskite is believed to be the third most abundant mineral throughout the lower mantle. Here we simultaneously measure the crystal structure and the shear-wave and compressional-wave velocities of samples of CaSiO3 perovskite, and provide direct constraints on the adiabatic bulk and shear moduli of this material. We observe that incorporation of titanium into CaSiO3 perovskite stabilizes the tetragonal structure at higher temperatures, and that the material’s shear modulus is substantially lower than is predicted by computations3,4,5 or thermodynamic datasets6. When combined with literature data and extrapolated, our results suggest that subducted oceanic crust will be visible as low-seismic-velocity anomalies throughout the lower mantle. In particular, we show that large low-shear-velocity provinces (LLSVPs) are consistent with moderate enrichment of recycled oceanic crust, and mid-mantle discontinuities can be explained by a tetragonal-cubic phase transition in Ti-bearing CaSiO3 perovskite.
DS202007-1144
2020
Dobson, K.J.Haddock, D., Manya, S., Brown, R.J., Jones, T.J., Wadsworth, F.B., Dobson, K.J., Gernon, T.M.Syn-eruptive agglutination of kimberlite volcanic ash. PyroclastsVolcanica, Vol. 3, 1, pp. 169-182. PdfAfrica, Tanzaniadeposit - Igwisi Hills

Abstract: Pyroclastic deposits of the Holocene Igwisi Hills kimberlite volcanoes, Tanzania, preserve unequivocal evidence for rapid, syn-eruptive agglutination. The unusual pyroclasts are composed of ash-sized particles agglutinated to each other by thin necks. The textures suggest the magma was disrupted into droplets during ascent. Collisions between particles occurred within a volcanic plume and on deposition within the conduit to form a weakly agglutinated, porous pyroclastic deposit. Theoretical considerations indicate that agglutination occurred over short timescales. Agglutinated clasts were entrained into weak volcanic plumes and deposited around the craters. Our results support the notion that agglutination can occur during kimberlite eruptions, and that some coherent, dense rocks in ancient kimberlite pipes interpreted as intrusive rocks could instead represent agglutinated pyroclastic rocks. Differentiating between agglutinated pyroclastic rocks and effusive or intrusive rocks in kimberlite pipes is important because of the potential effects that pyroclastic processes might have on diamond concentrations in deposits.
DS202011-2040
2020
Dobson, K.J.Haddock, D., Manya, S., Brown, R.J., Jones, T.J., Wadsworth, F.B., Dobson, K.J., Gernon, T.M.Syn-eruptive agglutination of kimberlite volcanic ash.Volcanica, 15p. PdfAfrica, Tanzaniadeposit - Igwisi Hills kimberlite

Abstract: Pyroclastic deposits of the Holocene Igwisi Hills kimberlite volcanoes, Tanzania, preserve unequivocal evidence for rapid, syn-eruptive agglutination. The unusual pyroclasts are composed of ash-sized particles agglutinated to each other by thin necks. The textures suggest the magma was disrupted into droplets during ascent. Collisions between particles occurred within a volcanic plume and on deposition within the conduit to form a weakly agglutinated, porous pyroclastic deposit. Theoretical considerations indicate that agglutination occurred over short timescales. Agglutinated clasts were entrained into weak volcanic plumes and deposited around the craters. Our results support the notion that agglutination can occur during kimberlite eruptions, and that some coherent, dense rocks in ancient kimberlite pipes interpreted as intrusive rocks could instead represent agglutinated pyroclastic rocks. Differentiating between agglutinated pyroclastic rocks and effusive or intrusive rocks in kimberlite pipes is important because of the potential effects that pyroclastic processes might have on diamond concentrations in deposits.
DS1991-0388
1991
Dobson, M.R.Dobson, M.R.Placer deposits in submarine fan channelsMarine Mining, Vol. 9, pp. 495-506GlobalAlluvial placers, Gold, general
DS1991-1401
1991
Dobss, P.N.Rayner, R.J., Waters, S.B., McKay, I.J., Dobss, P.N., Shaw, A.L.The mid-Cretaceous paleoenvironment of central Southern Africa ( Orapa, Botswana)Paleogeography, Paleoclimatology, Paleoecology, Vol. 88, pp. 147-156BotswanaPaleoenvironment, Orapa
DS200712-0261
2007
Dobtresov, V.Y.Dobtresov, V.Y., Psakhe, S.G., Popov, V.L., Shilko, E.V., Granin, Timofeev,Astafurov, Dimaki, StarchevichIce cover of Lake Baikal as a model for studying tectonic processes in the Earth's crust.Doklady Earth Sciences, Vol. 413, 2, pp. 155-159.RussiaGeomorphology
DS2000-0952
2000
Dobtretsov, N.Theunissen, K., Dobtretsov, N., Korsakov, A.The diamond bearing Kokchetav ultra high pressure (UHP) Massif in northern Kazakhstan: exhumation structure.Terra Nova, Vol, 12, No. 4, pp. 181-187.Russia, KazakhstanUltrahigh pressure
DS201012-0422
2010
Dockweiler, P.J.Landreth, J.O., Dockweiler, P.J.Mountain Pass carbonatite project.International Workshop Geology of Rare Metals, held Nov9-10, Victoria BC, Open file 2010-10, extended abstract pp. 19-20.United States, CaliforniaCarbonatite
DS1994-0047
1994
Dodds, A.R.Anderson, A., Dodds, A.R., McMahon, S., Street, G.J.A comparison of airborne, ground electromagnetic techniques for mapping shallow zone resistivity variationsAseg Volume, Vol. 24, No. 3, 4, pp. 323-332AustraliaGeophysics -airborne electromagnetic, Models
DS1992-0369
1992
Doden, A.G.Doden, A.G., Gold, D.P.Unusual carbonate rich dikes and lamprophyres in Porcupine Dome, east central MontanaGeological Society of America (GSA) Abstracts with programs, 1992 Annual, Vol. 24, No. 7, abstract p. A262MontanaLamprophyres, Carbonate
DS1993-0363
1993
Doden, A.G.Doden, A.G., Gold, D.P.Kimberlite xenocrysts from the Porcupine Dome diatremes east-centralMontana: evidence for multiple sources of garnet and evaluation of diamondpotentialGeological Society of America Annual Abstract Volume, Vol. 25, No. 6, p. A98 abstract onlyMontanaXenocrysts, Garnet
DS1994-0438
1994
Doden, A.G.Doden, A.G., Gold, D.P., Walker, R.Geochemistry of diatremes and dikes with lamprophyric/carbonatitic affinities from discrete alkalic intrusive centres in Montana.Geological Association of Canada (GAC) Abstract Volume, Vol. 19, p. PosterMontanaCarbonatite, Geochemistry
DS1996-0371
1996
Doden, A.G.Doden, A.G.Ultramafic lamprophyres from Porcupine Dome, east central Montana, and their potential for diamonds.Wyoming 32nd. Annual Forum Geology Industrial Minerals, pp. 14-16.MontanaLamprophyres, Porcupine Dome
DS1997-0281
1997
Doden, A.G.Doden, A.G., Gold, D.P.Origin of carbonatite minerals in ultramafic lamprophyres of CentralMontana.Geological Association of Canada (GAC) Abstracts, POSTER.MontanaCarbonatite, Lamprophyres
DS201704-0625
2016
Doden, A.G.Gold, D., Doden, A.G., Mbalu-Keswa, C., Tedeski, J.R., Mathur, R.The Rogue kimberlite dikes in Indiana County, Pennsylvania Part 1. unusual intrusive habit of kimberlite dikes in coal seams.Guidebook 81st annual field conference of Pennsylvania Geologists, Oct. 6-8, pp. 121-160.United States, PennsylvaniaDeposit - Rogue
DS201704-0626
2016
Doden, A.G.Gold, D., Doden, A.G., Mbalu-Keswa, C., Tedeski, J.R., Mathur, R.Supplement to guidebook: Petrography of the Tanoma and Ernest kimberlites.Guidebook 81st annual field conference of Pennsylvania Geologists, Oct. 6-8, pp. 263-268.United States, PennsylvaniaDeposit - Rogue
DS1993-0902
1993
Dodge, D.A.Lee, W.H., Dodge, D.A.A course on PC based seismic networksUnited States Geological Survey (USGS) Open File, No. 92-0441, 535p. $ 81.00GlobalGeophysics -seismics, Course notes
DS1986-0188
1986
Dodge, F.C.W.Dodge, F.C.W., Kistler, R.W., Calk, L.C.Deep crustal xenoliths, Chinese Peak. Sierra NevadaGeological Society of America, Vol. 18, No. 2, p. 102. (abstract.)CaliforniaCrustal genesis
DS1990-1456
1990
Dods, S.D.Teskey, D.J., Dods, S.D., Kuchs, R.P.New high resolution aeromagnetic survey of Lake Superior- a contribution to the Great Lakes International multidisciplinary program on crustal evolutionGLIMPCE.Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) Vancouver 90 Program with Abstracts, Held May 16-18, Vol. 15, p. A129.. AbstractMidcontinentGeophysics -aeromagnetics, GLIMPCE.
DS1991-1711
1991
Dods, S.D.Teskey, D.J., Thomas, M.D., Gibb, R.A., Dods, S.D., Kucks, R.P.High resolution aeromagnetic survey of Lake SuperiorEos, Vol. 72, No. 8, February 19, p. 81, 85, 86Ontario, MichiganBlank
DS1989-0361
1989
Dods, S.W.Dods, S.W., Hinze, W.J., Keating, P., Smith, J.G.Magnetic and gravity anomaly maps of the Lake Huron region35th. Annual Institute On Lake Superior Geology, Proceedings And, pp. 21Michigan, OntarioGeophysics
DS1981-0080
1981
Dodson, M.H.Bell, K., Dodson, M.H.The Geochronology of the Tanzanian ShieldJournal of GEOLOGY, Vol. 89, PP. 109-128.Tanzania, East Africa, Kenya, UgandaCraton, Age Dating, Isotope
DS1989-0362
1989
Dodson, M.H.Dodson, M.H.Diamond dating anomalies (editorial)Nature, Vol. 337, No. 6204, January 19, p. 207GlobalGeochronology, Diamond
DS1992-0370
1992
Doe, B.R.Doe, B.R.Challenging questions for geology and geophysics in the 21st. centuryUnited States Geological Survey (USGS) Open File, No. 92-515, 21p. $ 3.25GlobalGeophysics
DS1993-0364
1993
Doe, B.R.Doe, B.R.Geochemistry of oceanic igneous rocks: ridges and islandsUnited States Geological Survey (USGS) Open File, No. 93-393A, B 11p. and disc. $ 11.75 totalOceanGeochemistry, Igneous rocks
DS2002-0389
2002
Doe, B.R.Doe, B.R.Further considerations of the Ce Yb vs Ba Ce plot in volcanology and tectonicsInternational Geology Review, Vol. 44, 10, pp. 877-912.GlobalTectonics - general not specific to diamonds
DS200412-0465
2004
Doe, B.R.Doe, B.R.Should a nephelinitic series - bearing Oceanic Island be drilled for carbonatites, kimberlites and ultrapotassic rocks?International Geology Review, Vol. 46, no. 3, pp. 158-161.Europe, Cape Verde IslandsCarbonatite
DS1990-0410
1990
DOE.DOE.Resource allocation and mine costing modelNational Technical Information Service, PB 82-500388/WNR Code = approx. $ 240.00 United StatesUnited StatesMine costing model, ore reserves, economics, Book -ad
DS1998-0356
1998
Doeflinger, E.Doeflinger, E., Bayer, R., Chery, J., Burki, B.The Global Position System in mountainous areas: effect of the troposhereon the vertical GPS accuracyC.r. Academy Of Science Paris, Vol. 326, pp. 319-325GlobalGPS, Mountain region
DS1860-0337
1880
Doell, E.Doell, E.Zum Vorkommen des Diamants im Itakolumite Brasiliens und Inden Kopjen Afrikas.Verhandlungen der kk geologischen Reichsanstalt (WIEN), Vol. 8, No. 5, PP. 78-80.Africa, South Africa, South America, BrazilDiamond, Geology
DS1860-0798
1893
Doelter, C.Doelter, C.EdelsteinkundeLeipzig:, Africa, South Africa, GlobalGemology
DS1910-0270
1912
Doelter, C.Doelter, C., et al.Handbuch der Mineralchemie #2Dresden And Leipzig: Steinkopff., Vol. 1, (DIAMOND PP. 28-56.).GlobalKimberlite
DS1910-0175
1911
Doelter, C. VON.Doelter, C. VON.Handbuch der Mineralchemie #1Dresden: Theodor Steinkopff., Vol. 1, PT. 1, PP. 1-160.GlobalMineralogy, Classification, Physical Chemistry, Diamond
DS201012-0833
2010
Doering, P.Wang, W., Doering, P., Tower, J., Lu, R., Eaton-Magana, S., Johnson, P., Emerson, E., Moses, T.M.Strongly coloured pink CVD lab grown diamonds. A new generation of CVD lab-grown diamonds from Apollo Diamond Inc.Gems & Gemology, Vol. 46, 1, Spring pp. 4-17.TechnologyCVD Pink synthetics
DS200712-0104
2006
Doermann, L.Braunmiller, J., Van der Lee, S., Doermann, L.Mantle transition zone thickness in the central South American subduction zone.American Geophysical Union, Geophysical Monograph, No. 168, pp. 215-224.South AmericaSubduction
DS1997-1225
1997
Doermer, W.M.Wannamaker, P.E., Doermer, W.M., Johnston, J.M.Subdued state of tectonism of Great Basin interior relative to margin Based on deep resistivity structureEarth and Planetary Science Letters, Vol. 150, No. 1-2, July pp. 41-102.GlobalTectonics, Geophysics - seismics
DS1993-0950
1993
Doggett, M.Mackenzie, B.W., Doggett, M.How to appraise mineral resourcesCrs Perspective, No. 42, January pp. 28-34CanadaEconomics, MIneral appraisal, ore reserves
DS200612-0341
2006
Doggett, M.Doggett, M.The sky is falling, the sky is falling: the dwindling supply of talent in the mineral industry.Society of Exploration Geophysics, Oct. 4, 28 power point (views)GlobalDemographics of people in industry
DS1992-0975
1992
Doggett, M.D.Mackenzie, B.W., Doggett, M.D.Economics of mineral exploration in AustraliaCentre for Resource Studies, 269p. $ 125.00AustraliaEconomics, Book -ad
DS1992-0976
1992
Doggett, M.D.Mackenzie, B.W., Doggett, M.D.Economic potential of mining in Manitoba: developing taxation policyCentre for Resource Studies, June 124pManitobaEconomics, Legal, Policy and mining taxation
DS1994-0439
1994
Doggett, M.D.Doggett, M.D., Mackenzie, B.W.Mineral potential on Canada's frontiersCrs Perspectives, No. 48, February pp. 19-27CanadaEconomics, Mineral policies for remote areas
DS1995-1135
1995
Doggett, M.D.Mackenzie, B.W., Doggett, M.D.The changing economic climate for mineral supply in CanadaCentre for Resource Studies, Mon. 31, 100p. $ 25.00CanadaEconomics, Mineral supply
DS1910-0525
1917
Doghty, F.W.Doghty, F.W.Early Diamond Discoveries of North AmericaJewellers Circular Keystone, Vol. 74, No. 25, JULY 25TH. P. 41, 43, 45.United States, CanadaBlank
DS1992-0371
1992
Doglioni, C.Doglioni, C.Main differences between thrust beltsTerra Nova, Vol. 4, No. 2, pp. 152-164GlobalStructure, Thrust belts -overview
DS1993-0365
1993
Doglioni, C.Doglioni, C.Some remarks on the origin of foredeepsTectonophysics, Special issue Crustal controls on the internal architecture, Vol. 228, No. 1-2, pp. 1-20GlobalBasin, Foredeep
DS1993-0366
1993
Doglioni, C.Doglioni, C.Geological evidence for a global tectonic polarityJournal of the Geological Society of London, Vol. 150, No. 5, September pp. 9991-1002MantleTectonics, Plate moving mechanisms
DS1994-0440
1994
Doglioni, C.Doglioni, C.Foredeeps versus subduction zonesGeology, Vol. 22, No. 3, March pp. 271-274MantleSubduction, Thrust belts
DS1995-0430
1995
Doglioni, C.Doglioni, C.Geological remarks on the relationships between extension and convergent geodynamic settingsTectonophysics, Vol. 252, No. 1-4, Dec. 30, pp. 253-284GlobalBasin, Tectonics -extension, convergent
DS1999-0171
1999
Doglioni, C.Doglioni, C., Harabaglia, P., Piromallo, C.Orogens and slabs vs their direction of subductionEarth Science Reviews, Vol. 45, No. 3-4, Mar. pp. 167-208.GlobalTectonics, geodynamics, subduction
DS2003-0342
2003
Doglioni, C.Doglioni, C., Carminati, E., Bonatti, E.Rift symmetry and continental upliftTectonics, Vol. 22, 3, pp. 10/1029/2002TC001459GlobalTectonics, Review
DS200412-0466
2003
Doglioni, C.Doglioni, C., Carminati, E., Bonatti, E.Rift symmetry and continental uplift.Tectonics, Vol. 22, 3, pp. 10/1029/2002 TC001459GlobalTectonics Review
DS200512-0198
2005
Doglioni, C.Cruciani, C., Carminati, E., Doglioni, C.Slab dip vs lithosphere age: no direct function.Earth and Planetary Science Letters, In press,Mantle, South AmericaSubduction zones, geochronology, plate tectonics
DS200512-0241
2005
Doglioni, C.Doglioni, C., Green, D.H., Mongelli, F.On the shallow origin of hotspots and the westward drift of the lithosphere.Plates, Plumes, and Paradigms, pp. 735-750. ( total book 861p. $ 144.00)MantleGeophysics
DS200512-0956
2006
Doglioni, C.Scoppola, B., Boccaletti, D., Bevis, M., Carminati, E., Doglioni, C.The westward drift of the lithosphere: a rotational drag?Geological Society of America Bulletin, Vol. 118, 1, pp. 199-209.MantleGeophysics
DS200612-0342
2006
Doglioni, C.Doglioni, C., Carminati, E., Cuffaro, M.Simple kinematics of subduction zones.International Geology Review, Vol. 48, 6, pp. 479-493.MantleSubduction
DS200712-0262
2007
Doglioni, C.Doglioni, C., Carminati, E., Cuffaro, M., Scrocca, D.Subduction, kinematics and dynamic constraints.Earth Science Reviews, Vol. 83, 3-4, pp. 125-175.MantleSubduction
DS200712-0263
2007
Doglioni, C.Doglioni, C., Carminati, E., Cuffaro, M., SCroo, D.Subduction kinematics and dynamic constraints.Earth Science Reviews, In press availableMantleSubduction
DS200812-0254
2008
Doglioni, C.Cuffaro, M., Caputo, M., Doglioni, C.Plate subrotations.Tectonics, Vol. 27, TC4007MantleTectonis
DS201012-0628
2010
Doglioni, C.Riguzzi, F., Panza, G., Varga, P., Doglioni, C.Can Earth's rotation and tidal despinning drive plate tectonics?Tectonophysics, Vol. 484, pp. 60-73.MantleTectonics
DS201312-0221
2013
Doglioni, C.Doglioni, C.Asymmetric mantle convection.Goldschmidt 2013, AbstractMantleSubduction
DS201312-0222
2013
Doglioni, C.Doglioni, C.Asymmetric plate tectonics and asymmetric mantle convection.Goldschmidt 2013, AbstractMantleSubduction
DS201511-1832
2015
Doglioni, C.Doglioni, C., Anderson, D.L.Top-driven asymmetric mantle convection.Geological Society of America Special Paper, No. 514, pp. SPE514-05.MantleConvection

Abstract: The role of decoupling in the low-velocity zone is crucial for understanding plate tectonics and mantle convection. Mantle convection models fail to integrate plate kinematics and thermodynamics of the mantle. In a first gross estimate, we computed at >300 km3/yr the volume of the plates lost along subduction zones. Mass balance predicts that slabs are compensated by broad passive upwellings beneath oceans and continents, passively emerging at oceanic ridges and backarc basins. These may correspond to the broad low-wavespeed regions found in the upper mantle by tomography. However, west-directed slabs enter the mantle more than three times faster (~232 km3/yr) than in the opposite east- or northeast-directed subduction zones (~74 km3/yr). This difference is consistent with the westward drift of the outer shell relative to the underlying mantle, which accounts for the steep dip of west-directed slabs, the asymmetry between flanks of oceanic ridges, and the directions of ridge migration. The larger recycling volumes along west-directed subduction zones imply asymmetric cooling of the underlying mantle and that there is an "easterly" directed component of the upwelling replacement mantle. In this model, mantle convection is tuned by polarized decoupling of the advecting and shearing upper boundary layer. Return mantle flow can result from passive volume balance rather than only by thermal buoyancy-driven upwelling.
DS1991-0990
1991
Doherty, W.Lightfoot, P.C., Sutcliffe, R.H., Doherty, W.Crustal contamination identified in Keweenawan Osler Group tholeiites, Ontario: a trace element perspectiveJournal of Geology, Vol. 99, pp. 739-760OntarioTholeiites, Crustal contamination, mantle magmas
DS1996-1244
1996
Doherty, W.Sage, R.P., Lightfoot, P.C., Doherty, W.Bimodal cyclical Archean basalts and rhyolites from the Michipicoten Wawa greenstone belt: geochemical evidencePrecambrian Research, Vol. 76, No. 3-4, Feb. 1, pp. 119-154OntarioMantle, magma lithosphere, Superior Province
DS1996-1245
1996
Doherty, W.Sage, R.P., Lightfoot, P.C., Doherty, W.Geochemical characteristics of granitoid rocks from within the Archean Michipicoten greenstone belt...WawaPrecambrian Research, Vol. 76, No. 3-4, Feb. 1, pp. 155-190OntarioSource regions, Tectonic evolution
DS1995-1745
1995
Dohm, C.E.Sichel, H.S., Dohm, C.E., Kleingeld, W.J.New generalized model of observed ore value distributionsInstitute of Mining and Metallurgy (IMM) Bulletin, Sect. A May-Aug, pp. A115-123GlobalGeostatistics, Ore reserves
DS1995-1746
1995
Dohm, C.E.Sichel, H.S., Dohm, C.E., Kleingeld, W.J.New generalized model of observed ore value distributionsTransactions of the Institute of Mining and Metallurgy (IMM)., Vol. 104, No. A, pp. A115-A123.South AfricaGeostatistics, Diamonds mentioned
DS2003-0343
2003
Dohmen, R.Dohmen, R., Chakraborty, S.,Becker, H.W.Si and O diffusion in olivine and implications for characterizing plastic flow in the mantleGeophysical Research Letters, Vol. 29, 21, Nov. 1, p. 26 DOI 10.1029/2002GLO15480MantleChemistry
DS200712-0264
2007
Dohmen, R.Dohmen, R., Costa, F.Modeling of dehydrogenation of olivine during magma ascent.Plates, Plumes, and Paradigms, 1p. abstract p. A229.MantleNAM
DS1989-0363
1989
Dohr, G.Dohr, G.Deep seismic- a tool in the recognition and inter- pretation of large geologic elements: the starting point for deterministic basin modelingGeologische Rundschau, Vol. 78, No. 1, pp. 21-48GlobalBasin, Geophysics - seismic
DS1995-0431
1995
Dohrenwend, J.C.Dohrenwend, J.C., Yanez, G.P., Lowry, G.Cenozoic Lands cape evolution of the southern part of the Gran Sabana, southeastern Venezuela -implicationsUnited States Geological Survey (USGS) Bulletin., No. 2124-A, pp. K1-17.VenezuelaRoraima Group, laterites, paleoplacers, Placers, alluvials
DS201504-0226
2015
Dohring, E.Valentine, G.A., Graettinger, A.H, Macorps, E., Ross, P-S., White, J.D.L., Dohring, E., Sonder, I.Experiments with vertically and laterally migrating subsurface explosions with applications to the geology of phreatomagmatic and hydrothermal explosion craters and diatremes.Bulletin of Volcanology, Vol. 77, 15p.TechnologyDiatremes, kimberlites
DS1981-0141
1981
Dohrmann, B.Dohrmann, B.Grow Rich With DiamondsSan Francisco: Harbor Publishing, (g.p. Putnam's Sons.)., 167P.GlobalKimberley, Investing
DS1988-0777
1988
Doi, A.Yoshioka, T., Imai, O., Ohara, H., Doi, A., Fujimori, N.Thin solid films of ceramic and diamond and their applicationSurf. Coat. Technol, Vol. 36, No. 1-2, pp. 311-318GlobalDiamond applications/coatings
DS1960-0943
1968
Doig, R.Doig, R., Barton, J.M.Ages of Carbonatites and other Alkaline Rocks in QuebecCanadian Journal of Earth Sciences, Vol. 5, PP. 1401-1407.Canada, QuebecGeochronology
DS1970-0713
1973
Doig, R.Helmstaedt, H., Doig, R.Eclogite Nodules from Kimberlite Pipes of the Colorado Plateau Samples of Subducted Franciscan Type Oceanic Lithosphere. #1International Kimberlite Conference FIRST EXTENDED ABSTRACT VOLUME., PP. 171-172.United States, Colorado Plateau, Colorado, Arizona, Utah, New MexicoDiatreme
DS1975-0103
1975
Doig, R.Helmstaedt, H., Doig, R.Eclogite Nodules from Kimberlite Pipes of the Colorado Plateau-samples of Subducted Franciscan Type Oceanic Lithosphere. #2Physics and Chemistry of the Earth, Vol. 9, PP. 95-111.United States, Colorado PlateauBlank
DS1987-0156
1987
Doig, R.Doig, R.Rubidium-Strontium geochronology and metamorphic history of Proterozoic to early Archean rocks north of Cape SmithCanadian Journal of Earth Sciences, Vol. 24, pp. 813-25.QuebecGeochronology, Cape Smith
DS1998-0357
1998
Doig, R.Doig, R.Paleoseismological evidence from lake sediments for recent movement on the Denali and other faults, Yukon.Tectonophysics, Vol. 296, No. 3-4, Nov. 10, pp. 363-70.YukonGeophysics - seismics, Structure
DS1970-0444
1971
Doil'nitsyn, YE. F.Vyshemirskiy, V.S., Doil'nitsyn, YE. F., et al.Organic Origin of Bitumens in the Vilyuy Kimberlite PipesDoklady Academy of Sciences USSR EARTH SCI., Vol. 197, No. 1-6, PP. 215-216.RussiaKimberlite
DS200512-0254
2005
DoinDumoulin, C., Doin, M-P, Arcay, D., Fleitout, L.Onset of small scale instabilities at the base of the lithosphere: scaling laws and role of pre-existing lithospheric structures.Geophysical Journal International, Vol. 160, 1, pp. 345-357.MantleGeophysics - seismics
DS1997-0282
1997
Doin, M.P.Doin, M.P., Fleitout, L., Christensen, U.Mantle convection and stability of depleted and undepleted continentallithosphere.Journal of Geophysical Research, Vol. 102, No. 2, Feb. 10, pp. 2771-88.MantleMagmatism
DS2001-0264
2001
Doin, M.P.Doin, M.P., Henry, P.Subduction initiation and continental crust recycling: the roles of rheology and eclogitization.Tectonophysics, Vol. 342, No. 2, pp. 163-91.MantleEclogites, Subduction
DS2001-0280
2001
Doin, M.P.Dumoulin, C., Doin, M.P., Fleitout, L.Numerical simulations of the cooling of an oceanic lithosphere above a convective mantle.Physics of the Earth and Planetary Interiors, Vol. 125, No. 1-4, pp. 45-64.MantleFluid viscosity, Experimental
DS2001-0281
2001
Doin, M.P.Dumoulin, C., Doin, M.P., Fleitout, L.Numerical simulations of the cooling of an oceanic lithosphere above a convective mantle.Physical Earth and Planetary Interiors, Vol. 125, No. 1-4, pp. 45-64.MantleConvection
DS2002-1090
2002
Doin, M.P.Morency, C., Doin, M.P., Dumoulin, C.Convective destabilization of a thickened continental lithosphereEarth and Planetary Science Letters, Vol. 202, 2, pp. 303-320.MantleTectonics
DS200412-1366
2004
Doin, M.P.Morency, C., Doin, M.P.Numerical simulations of the mantle lithosphere delamination.Journal of Geophysical Research, Vol. 109, B3, 10.1029/2003 JB002462MantleStratigraphy
DS200512-0027
2005
Doin, M-P.Arcay, D., Tric, E., Doin, M-P.Numerical simulations of subduction zones: effect of slab dehydration on the mantle wedge dynamics.Physics of the Earth and Planetary Interiors, Vol. 149, 1-2, March 15, pp. 133-153.MantleSubduction
DS200612-0032
2006
Doin, M-P.Arcay, D., Doin, M-P., Tric, E., Bousquet, R.D.Overriding plate thinning in subduction zones: localized convection induced by slab dehydration.Geochemistry, Geophysics, Geosystems: G3, Vol. 7, Q02007MantleGeothermometry, hydrated slab-derived water fluxes
DS200712-0024
2007
Doin, M-P.Arcay, D., Doin, M-P., Tric, E., Bousquet, R.D.Influence of the precollisional stage on subduction dynamics and the buried crust thermal state: insights from numerical simulations.Tectonophysics, Vol. 441, pp. 27-45.MantleSubduction
DS200712-0026
2007
Doin, M-P.Arcay, D., Tric, E., Doin, M-P.Slab surface temperature in subduction zones: influence of the interplate decoupling depth and upper plate thinning process.Earth and Planetary Science Letters, Vol. 255, 3-4, March 30, pp. 324-338.MantleSubduction
DS1996-1067
1996
Doiron, A.Parent, M., Paradis, S.J., Doiron, A.Palimpset glacial dispersal trains and their significance for driftprospectingJournal of Geochm. Explor, Vol. 56, No. 2, Oct. pp. 123-140Quebec, LabradorGeochemistry, geomorphology, Drift prospecting
DS201602-0198
2015
Dokht, R.M.H.Chen, Y., Gu, Y.J., Dokht, R.M.H., Sacchi, M.D.Crustal imprints of Precambrian orogenesis in western Laurentia.Journal of Geophysical Research, Vol. 120, 10, pp. 6993-7012.Canada, AlbertaGeophysics - seismics LVZs

Abstract: Crustal low-velocity zones (LVZs) have been reported in active orogens such as the Himalayas and the Andes but rarely in stable cratonic regions. In this study, we provide compelling evidence for a significant midcrustal LVZ beneath eastern-central Alberta, an integral part of the Precambrian Canadian Shield covered by thick Phanerozoic sedimentary deposits. This 200?km wide, over 10?km thick midcrustal LVZ is well resolved by shear velocity inversions using P-to-S receiver functions from more than 4600 earthquakes. It is generally overlain by a high-velocity upper crust in the depth range of 8-15?km, especially in western-central Alberta, which coincides with the previously documented Winagami reflection sequence. We interpret the LVZ to be of granitic composition, potentially in connection with the crystallization of partially molten crust during the Paleoproterozoic eon. In addition to the Precambrian tectonic history of western Laurentia, which featured plate convergence conducive to crustal melting, our crustal model is further supported by (1) a moderate spatial correlation between the LVZ and heat flow, and (2) shear velocities consistent with that of granite. The well preserved Winagami reflection sequence and the LVZ are potential evidence of distinct episodes of magmatism and crust modification in the Precambrian basement of the Western Canada Sedimentary Basin. The existence of a broad crustal LVZ suggests extensive subduction, orogenesis, and crustal melting during the Precambrian assembly of the North American craton.
DS1991-0472
1991
Dokol, A.G.Fedorov, I.I., Chepurov, A.I., Osorgin, N.Y., Dokol, A.G., Sobolev, V.The experimental and thermodynamic modelling of C-O-H fluid in equilibrium with graphite and diamond at high pressuret parameters.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 320, No. 3, pp. 710-713RussiaExperimental mineralogy, Graphite, diamond
DS201701-0018
2016
Dokuchaev, A.Ya.Kargin, A.V., Nosova, A.A., Postnikov, A.V., Chugaev, A.V., Postnikova, O.V., Popova, L.P., Poshibaev, V.V., Sazonova, L.V., Dokuchaev, A.Ya., Smirnova, M.D.Devonian ultramafic lamprophyre in the Irkineeva Chadobets trough in the southwest of the Siberian platform: age, composition, and implications for diamond potential prediction.Geology of Ore Deposits, Vol. 58, 5, pp. 383-403.RussiaLamprophyre - aillikite

Abstract: The results of geochronological, mineralogical, petrographical, and geochemical study of the Ilbokich ultramafic lamprophyre are reported. The specific features in the mineral and chemical compositions of the studied ultramafic lamprophyre indicate that it can be regarded as a variety similar to aillikite, while other differences dominated by K-feldspar can be referred to damtjernite. According to Rb-Sr analysis, ultramafic lamprophyre dikes intruded at the turn of the Early and Middle Devonian, about 392 Ma ago. This directly proves the existence of Early Paleozoic alkali-ultramafic magmatism in the northern part of the southwest Siberian Platform. A finding of Devonian alkali-ultramafic lamprophyre is of dual predictive importance. On the one hand, it is indicative of the low probability of finding large diamond-bearing deposits in close association with aillikite. On the other hand, it can be indicative of a possible large Devonian diamond province in the studied territory, where diamondiferous kimberlite is structurally separated from aillikite.
DS201811-2554
2018
Dokuchaev, A.Ya.Bogatikov, O.A., Dokuchaev, A.Ya., Kargin, E.V., Yutkina, E.V., Kondrashov, I.A.Paleoproterozic kimberlites of the Lake Kimozero area, Karelian craton: ore mineralization in kimberlites and fault zones.Doklady Earth Sciences, Vol. 482, 1, pp. 1130-1133.Russiadeposit - Lake Kimozero

Abstract: Syngenetic and epigenetic ore mineralization was studied in Paleoproterozoic metakimberlites in the area of Kimozero Lake. In the Kimozero structure, redeposited ore mineralization is constrained to fracture and shear zones and consists of Fe-vaesite, Fe-Co-polydymite, millerite, Ni-pyrrhotite, pentlandite, chalcopyrite, Zn-bearing copper, galena, and Ni-pyrite. The composition of this mineralization is analogous to that of syngenetic mineralization in pyroclastic and coherent kimberlite, and its likely source was the kimberlite itself.
DS202010-1848
2020
Dokuchaev, A.Ya.Kargin, A.V., Nosova, A.A., Babarina, I.I., Dokuchaev, A.Ya., Kondrashov, I.A.Paleproterozoic kimberlites of Kimozero: petrographic facies recstruction of kimberlite pipe overcoming tectonic and metamorphic modification.Doklady Earth Sciences, Vol. 493, 1, pp. 522-525.Russiadeposit - Kimozero

Abstract: Based on a detailed petrographic investigation and geological observations of the Paleoproterozoic Kimozero kimberlite (Karelia, Russia), we present a new model of kimberlite pipe with multiphase and mono-crater structure. We recognised volcanoclastic and coherent kimberlite series that filled the inner and outer zones of the kimberlite crater. The multiphase structure, emplacement style, petrography and reconstructed size of the Kimozero kimberlite correspond to Phanerozoic kimberlite pipes.
DS201412-0199
2014
Dokuchits, E.Y.Dokuchits, E.Y., Vladykin, N.V.Chemical composition, geochemical features and genesis of charoite and charoite rocks, Murun Complex.30th. International Conference on Ore Potential of alkaline, kimberlite and carbonatite magmatism. Sept. 29-, RussiaCharoite
DS201801-0006
2017
Dokuchits, E.Yu.Borovikov, A.A., Vladykin, N.V., Tretiakova, I.G., Dokuchits, E.Yu.Physicochemical conditions of formation of hydrothermal titanium mineralization on the Murunskiy alkaline massif, western Alden ( Russia).Ore Geology Reviews, in press available, 10p.Russiaalkaline rocks
DS201012-0499
2010
DokukinaMints, M.V., Belousova, E.A., Konilov, A.N., Natapov, Shchipansky, Griffin, O'Reilly, Dokukina, KaulinaMesoarchean subduction processes: 2.87 Ga eclogites from the Kola Peninsula, Russia.Geology, Vol. 38, 8, pp. 739-742.Russia, Kola PeninsulaBelomorian
DS201012-0500
2010
DokukinaMints, M.V., Konilov, A.N., Dokukina, Kaulina, Belousova, Natapov, Griffin, O'ReillyThe Belomorian eclogite province: unique evidence of Meso-Neoarchean subduction and collisionsDoklady Earth Sciences, Vol. 434, 2, pp. 1311-1316.RussiaEclogite
DS201612-2294
2016
Dokukina, K.A.Dokukina, K.A., Mints, M.V., Konilov, A.N.Mesoarchean Gridino mafic dykes swarm of the Belomorian eclogite province of the Fennoscandian shield ( Russia). Acta Geologica Sinica, Vol. 90, July abstract p. 8.Russia, Kola PeninsulaDykes
DS202010-1861
2020
Dokukina, K.A.Mints, M.V., Dokukina, K.A.Age of eclogites formed by the subduction of the mesoarchean oceanic crust (salma, belomorian eclogite province, eastern fennoscandian shield, Russia): a synthesis.Precambrian Research, doi.org/10.1016/j.precamres.2020.105879in press available, 80p. Pdf Russiaeclogites

Abstract: Competing evolutionary models and age of eclogite facies metamorphism, Mesoarchaean, Neoarchaean or Palaeoproterozoic, of the subducted Mesoarchaean oceanic crust (Salma association, Belomorian Eclogite Province) are discussed on a basis of systematic analysis of previously known and newly obtained data. Four main types of zircons were distinguished in eclogites: porous crystals with numerous inclusions from eclogite-metagabbro; wide-rimmed zircons with relict porous cores similar to previous type separated from garnetites; round-oval zircons from eclogite-metagabbronorite that are characteristic for granulite facies rocks and zircons with euhedral oscillatory zoning cores and oval grains that are characteristic for the eclogite facies pillow basalts. Regular changes in REE patterns and in crystallization-recrystallization temperatures of certain domains of the porous zircons display sequence of magmatic and metamorphic events. The?~?2.9?Ga domains retain magmatic-type REE patterns. Low- and medium-temperature inclusions of prenite, pumpelliite, albite, actinolite, chlorite, diaspore and saponite in garnet and abundant microinclusions of the prenite-pumpelliite and greenschist facies in zircons with LREE-MREE enrichment indicate hydrothermal metamorphism in the spreading ridge and ocean floor at 2.9-2.82?Ga. Disappearance of Ce positive anomaly from REE pattern in zircon, change negative to positive Eu anomaly and LREE-MREE enrichment caused by plagioclase removal and replacement of rutile with sphene evidence eclogite facies metamorphism linked with subduction at 2.82-2.78?Ga. Temperatures in the 700-900?°C range of the round-oval zircons from eclogite-metagabbronorite records the Neoarchaean granulite facies overprint at 2.77-2.70?Ga. Series of the high temperature Palaeoprpoterozoic events was terminated by 2.1-1.7?Ga event marked by the rims with lowest REE that frame all types of zircons. Change from positive to negative Eu anomaly, retrieval of negative Ce anomaly indicate the presence of plagioclase, reduction type of fluids and low water activity characteristic of high-temperature metamorphism under stretching condition and mantle-plume activity. The deep reworking of the Sm-Nd isotope system in the Belomorian tectonic province at?~?1.9?Ga, including the Salma eclogite association, was caused by the enormous crustal heating that spread from the Lapland granulite belt southward. Radiogenic 176Hf enrichment of 1.9?Ga zircon indicates recrystallization of a long-existed garnet with release of significant amount of 176Hf.
DS1985-0150
1985
Dokulenc, A.Dokulenc, A.Mineralogy: the Leucite HillsLapidary Journal, Vol. 39, No. 9, December pp. 64-65WyomingLeucite
DS1970-0504
1972
Dolanski, J.Dolanski, J., Beckett, J.Heavy Mineral Identifications from Various Diamond Bearing Leads.New South Wales Geological Survey, GS 1972/14; GS 1972/211, (UNPUBL.).AustraliaKimberlite, Heavy Mineral Concentrates
DS2001-1145
2001
DolbySweet, A.R., Stasiuk, McIntyre, Dolby, Hamblin, KiviStratigraphy of the eroded sedimentary cover recorded by xenoliths and crater fill sediments associated....29th. Yellowknife Geoscience Forum, Nov. 21-23, abstract p. 86-7.Northwest TerritoriesStratigraphy, Lac de Gras field
DS2002-0390
2002
Dold, B.Dold, B., Fontbote, L.Element cycling and secondary mineralogy in porphyry copper tailings as a function of climate, mineralogyJournal of Geochemical Exploration, Vol.74,1-3,pp.3-55.ChileCopper - mining, primary mineralogy, mineral processing, Deposit - la Andina, El Teniente, El Salvador
DS2002-0391
2002
Dolde, J.L.Dolde, J.L.Structural relationships, Millcreek, Madison County, Missouri16th. International Conference On Basement Tectonics '02, Abstracts, 2p., 2p.MissouriStructure
DS200812-0896
2007
Dolejs, D.Piazzoni, A.S., Steinle-Neumann, G., Bunge, H-P., Dolejs, D.A mineralogical model for density and elasticity of the Earth's mantle.Geochemistry, Geophysics, Geosystems: G3, Vol. 8, 11, Nov. 30, pp. 1-23.MantleMineralogy
DS201112-1012
2011
Dolejs, D.Stremprok, M., Seifert, Th., Dolejs, D.Geochemistry of lamprophyres in rare metal districts related to granitoids.Goldschmidt Conference 2011, abstract p.1937.Europe, RussiaMinette, kersantite
DS201312-0071
2013
Dolejs, D.Bernini, D., Wiedenbeck, M., Dolejs, D., Keppler, H.Partitioning of halogens between mantle minerals and aqueous fluids: implications for the fluid flow regime in subduction zones.Contributions to Mineralogy and Petrology, Vol. 165, pp. 117-128.MantleMetasomatism, subduction
DS201705-0864
2017
Dolejs, D.Novella, D., Dolejs, D., Myhill, R., Pamato, M.G., Manthilake, G., Frost, D.J.Melting phase relations in the systems Mg2SiO4-H2O and MgSiO3-H2O and the formation of hydrous melts.Geochimica et Cosmochimica Acta, Vol. 204, pp. 68-82.MantleMelting

Abstract: High-pressure and high-temperature melting experiments were conducted in the systems Mg2SiO4-H2O and MgSiO3-H2O at 6 and 13 GPa and between 1150 and 1900 °C in order to investigate the effect of H2O on melting relations of forsterite and enstatite. The liquidus curves in both binary systems were constrained and the experimental results were interpreted using a thermodynamic model based on the homogeneous melt speciation equilibrium, H2O + O2- = 2OH-, where water in the melt is present as both molecular H2O and OH- groups bonded to silicate polyhedra. The liquidus depression as a function of melt H2O concentration is predicted using a cryoscopic equation with the experimental data being reproduced by adjusting the water speciation equilibrium constant. Application of this model reveals that in hydrous MgSiO3 melts at 6 and 13 GPa and in hydrous Mg2SiO4 melts at 6 GPa, water mainly dissociates into OH- groups in the melt structure. A temperature dependent equilibrium constant is necessary to reproduce the data, however, implying that molecular H2O becomes more important in the melt with decreasing temperature. The data for hydrous forsterite melting at 13 GPa are inconclusive due to uncertainties in the anhydrous melting temperature at these conditions. When applied to results on natural peridotite melt systems at similar conditions, the same model infers the presence mainly of molecular H2O, implying a significant difference in physicochemical behaviour between simple and complex hydrous melt systems. As pressures increase along a typical adiabat towards the base of the upper mantle, both simple and complex melting results imply that a hydrous melt fraction would decrease, given a fixed mantle H2O content. Consequently, the effect of pressure on the depression of melting due to H2O could not cause an increase in the proportion, and hence seismic visibility, of melts towards the base of the upper mantle.
DS201802-0226
2017
Dolejs, D.Chust, T.C., Steinle Neumann, G., Dolejs, D., Schuberth, B.S., Bunge, H.P.A computational framework for mineralogical thermodynamics. MMA-EoSJournal of Geophysical Research, Vol. 122, 10.1002/2017JB014501Mantlethermodynamics

Abstract: We present a newly developed software framework, MMA-EoS, that evaluates phase equilibria and thermodynamic properties of multicomponent systems by Gibbs energy minimization, with application to mantle petrology. The code is versatile in terms of the equation-of-state and mixing properties and allows for the computation of properties of single phases, solution phases, and multiphase aggregates. Currently, the open program distribution contains equation-of-state formulations widely used, that is, Caloric-Murnaghan, Caloric-Modified-Tait, and Birch-Murnaghan-Mie-Grüneisen-Debye models, with published databases included. Through its modular design and easily scripted database, MMA-EoS can readily be extended with new formulations of equations-of-state and changes or extensions to thermodynamic data sets. We demonstrate the application of the program by reproducing and comparing physical properties of mantle phases and assemblages with previously published work and experimental data, successively increasing complexity, up to computing phase equilibria of six-component compositions. Chemically complex systems allow us to trace the budget of minor chemical components in order to explore whether they lead to the formation of new phases or extend stability fields of existing ones. Self-consistently computed thermophysical properties for a homogeneous mantle and a mechanical mixture of slab lithologies show no discernible differences that require a heterogeneous mantle structure as has been suggested previously. Such examples illustrate how thermodynamics of mantle mineralogy can advance the study of Earth's interior.
DS201802-0229
2017
Dolejs, D.Crust. T.C., Steinle-Neumann, G., Dolejs, D., Schuberth, B.S., Bunge, H.P.MMA-EoS: a computational framework for mineralogical thermodynamics.Journal of Geophysical Research, 122, https://doi.org/10.1002/2017JB014501Technologyprogram - MMA-EoS
DS1993-0070
1993
Dolgal, A.S.Balk, P.I., Dolgal, A.S., Balk, T.V.Grid methods for solving inverse problems and practice of their usage while tracing differentiated intrusions according to gravity survey dataRussian Geology and Geophysics, Vol. 34, No. 5, pp. 112-118RussiaGeophysics -gravimetric, Formula - mathematical equations
DS1986-0043
1986
Dolgov, Yu.A.Bakumento, I.T., Dolgov, Yu.A., Doroshev, A.M., et al.Physicochemical formation conditions and features of The composition of rocks of the crust and upper mantleSoviet Geology and Geophysics, Vol. 27, No. 1, pp. 81-88RussiaDiamond, Genesis
DS1986-0841
1986
Dolgov, Yu.A.Vishnevskii, S.A., Dolgov, Yu.A., Sobolev, N.V.Lamproites of the Talakhtakh diatreme on the eastern slope of the AnabarshieldSoviet Geology and Geophysics, Vol. 27, No. 8, pp. 15-24RussiaLamproite
DS1998-0179
1998
Dolgunin, A.V.Budaev, D.A., Dolgunin, A.V., Fomin, A.S.An algorithm of kimberlite Diamondiferous estimations7th International Kimberlite Conference Abstract, pp. 111-12.Russia, YakutiaDiamond petrochemistry - Ti contnent, Deposit - Botuobinskaya
DS1991-0389
1991
Dolivo-Dobrovolskiy, D.V.Dolivo-Dobrovolskiy, D.V., evdokimov, M.D.Zirconium mineralization of the alkalic metasomatites of the MurunComplexInternational Geology Review, Vol. 33, No. 5, May pp. 490-496RussiaAlkaline rocks, Alteration, Metasomatism
DS202101-0022
2020
Dolnicek, Z.Kropac, K., Dolnicek, Z., Uher, P., Burianek, D., Safai, A., Urubek, T.Zirconian-niobian titanite and associated Zr-, Nb-, REE-rich accessory minerals: products of hydrothermal overprint of leucocratic teschenites ( Sileasian Unit, outer western Carpathians, Czech Republic).Geologica Carpathica ** Eng, Vol. 71, 4, pp. 343-360. pdfEurope, Czech Republicalkaline rocks

Abstract: Sills of hydrothermally altered alkaline magmatic rock (teschenite) of Lower Cretaceous age at the Certák and Repište sites in the Silesian Unit (Flysch Belt of the Outer Western Carpathians, Czech Republic) host leucocratic dykes and nests which contain accessory minerals enriched in Zr, Nb and REE: Zr-, Nb-rich titanite, zircon, gittinsite, pyrochlore, monazite, REE-rich apatite, epidote, and vesuvianite. Titanite forms wedge-shaped crystals or irregular aggregates enclosed in the analcime groundmass or overgrowths on Zr-rich ferropargasite and taramite or Zr-rich aegirine-augite to aegirine. Titanite crystals show oscillatory or irregular patchy to sector zoning and contain up to 17.7 wt. % ZrO2 and 19.6 wt. % Nb2O5, and =1.1 wt. % REE2O3. High-field-strength elements (HFSE) are incorporated into the structure of the studied titanite predominantly by substitutions: (i) [6]Ti4+???[6]Zr4+; (ii) [6]Ti4+?+?[6]Al3+???[6]Zr4+?+?[6]Fe3+; and (iii) [6]2Ti4+???[6]Nb5+?+?[6](Al, Fe)3+. Magmatic fractional crystallization, high-temperature hydrothermal autometasomatic overprint and low-temperature hydrothermal alterations resulted in the formation of the HFSE-rich mineral assemblages within the leucocratic teschenites. Autometamorphic processes caused by high-temperature hypersaline aqueous solutions (salinity ~50 wt. %, ~390-510 °C), which were released from the HFSE-enriched residual melt, played a major role in the crystallization of Zr-, Nb-, and REE-rich minerals. The mobilization of HFSE could have occurred either by their sequestration into a fluid phase exsolved from the crystallizing melt or by superimposed alteration processes. The distinctive positive Eu anomaly (EuCN/Eu*?=?1.85) of leucocratic dykes infers possible mixing of Eu2+-bearing magmatic fluids with more oxidized fluids.
DS202101-0036
2014
Dolnicek, Z.Urubek, T., Dolnicek, Z., Kropac, K.Genesis of syntectonic hydrothermal veins in the igneous rock of teschenite association ( Outer western Carpathians, Czeck Republic): growth mechanisms and origin of fluids. ( REE) ** note dateGeologica Carpathica ** Eng, Vol. 65, 6, pp. 419-431. pdf doi: 10.15 /geoca-2015-0003Europe, Czech Republicalkaline rocks

Abstract: Hydrothermal mineralization hosted by the Lower Cretaceous igneous rock of the teschenite association at Jasenice (Silesian Unit, Flysch Belt, Outer Western Carpathians) occurs in two morphological types - irregular vein filled by granular calcite and regular composite vein formed by both fibrous and granular calcite and minor chlorite, quartz, and pyrite. Crosscutting evidence indicates that the granular veins are younger than the composite vein. The composite vein was formed by two mechanisms at different times. The arrangement of solid inclusions in the marginal fibrous zone suggests an episodic growth by the crack-seal mechanism during syntectonic deformation which was at least partially driven by tectonic suction pump during some stages of the Alpine Orogeny. Both the central part of the composite vein and monomineral veins developed in a brittle regime. In these cases, the textures of vein suggest the flow of fluids along an open fracture. The parent fluids of both types of vein are characterized by low temperatures (Th=66-163 °C), low salinities (0.4 to 3.4 wt. % NaCl eq.), low content of strong REE-complexing ligands, and d18O and d13C ranges of + 0.2/+12.5 %. SMOW and -11.8/-14.1 %. PDB, respectively. The parent fluids are interpreted as the results of mixing of residual seawater and diagenetic waters produced by dewatering of clay minerals in the associ-ated flysch sediments. The flow of fluids was controlled by tectonic deformation of the host rock.
DS1992-0372
1992
Dolphin, R.Dolphin, R.The great carat caper. story of Dia Met and BHPCanadian Business, Vol. 65, No. 2, February pp. 67, 68, 70, 72Northwest TerritoriesNews story, Dia Met, BHP
DS201710-2257
2017
Dolsa, S.F.Presser, J.L.B., Tondo, M.J., Dolsa, S.F., Rocca, M.C.L., Alonso, R.N., Benetiz, P., Larroza, F.A., Duarte, B.J.R., Cabral-Antunez, N.D.Brief comments on the impact metamorphism in Cerro Leon quartzites, western Paraguay. English abstract ** in PORTPyroclastic Flow, Vol. 7, 1,pp. 16-24.South America, Paraguayimpact diamonds

Abstract: The petrographic study of two samples (quartzite and impactite) of Cerro León, a mountain range located in the middle of very probable impact basins (Cerro Leon-1, 2, 3 and 4-department of Alto Paraguay, Western-Paraguay) indicated evidences of impact metamorphism: PDFs (Not decorated and decorated) and diaplectic glass. Associated with diaplectic glass, impact diamonds or diamond/lonsdaleite crystals (micro and small macros) were observed with a range of morphologies including isolated and mostly agglutinated crystal varieties. Impact diamonds estimated to have formed by carbonate impact metamorphism present in the sedimentary target-rock of the Silurian/Devonian age. The identification of elements that reveal the impact metamorphism, in the analyzed samples of the Cerro León, evidences that the area of occurrence that would have been indicated as Very Probable Impact Basin, would be more of an Impact Basin.
DS1987-0409
1987
Dolzhanskaya, T.Yu.Levin, V.Ya., Levina, I.A., Glebova, Z.M., Dolzhanskaya, T.Yu.Mineralogy of carbonatites of the Buldym massif in the VishnevoeMountains.(Russian)Mineraly Mestorozhd. Urala, Sverd., (in Russian), pp. 117-123RussiaBlank
DS1994-0425
1994
Domack, E.W.Deynoux, M., Miller, J.M.G., Domack, E.W., Eyles, N.Earth's glacial recordCambridge University of Press Book, 270p.Brazil, China, United States, West Africa, Mali, South AfricaGeomorphology -glacial record, Sedimentology
DS1996-0372
1996
Domanik, K.J.Domanik, K.J., Holloway, J.R.The stability and composition of phengitic muscovite and associated phases from 5.5 to 11 GPa: subductionGeochimica et Cosmochimica Acta, Vol. 60, No. 21, pp. 4133-50.GlobalEclogites, subduction zones, Petrology - experimental
DS200512-0564
2005
Dombrovskaya, M.Koper, K.D., Dombrovskaya, M.Seismic properties of the inner core boundary from PKiKP/P amplitude ratios.Earth and Planetary Science Letters, Vol. 237, 3-4, Sept. 15, pp. 680-694.MantleGeophysics - seismics
DS1995-1008
1995
Dombrovskya, Zh.V.Kotelnikov, D.D., Dombrovskya, Zh.V., Zinchuk, N.N.Major regularities of weathering of silicate rocks of various chemical and mineralogical types.Lithology and mineral resources, Vol. 30, No. 6, pp. 539-544.RussiaLaterites, Kimberlite, silicates
DS201412-0083
2014
Domeer, M.Bull, A.L., Domeer, M., Torsvik, T.H.The effect of plate motion history on the longevity of deep mantle heterogeneities.Earth and Planetary Science Letters, Vol. 401, pp. 172-182.MantleTectonics, Pangea
DS201112-0280
2011
Domeier, M.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
DS201607-1293
2016
Domeier, M.Domeier, M., Doubrovine, P.V., Torsvik, T.H., Spakman, W., Bull, A.L.Global correlation of mantle structure and past subduction.Geophysical Research Letters, Vol. 43, 10, pp. 4945-4953.MantleSubduction

Abstract: Advances in global seismic tomography have increasingly motivated identification of subducted lithosphere in Earth’s deep mantle, creating novel opportunities to link plate tectonics and mantle evolution. Chief among those is the quest for a robust subduction reference frame, wherein the mantle assemblage of subducted lithosphere is used to reconstruct past surface tectonics in an absolute framework anchored in the deep Earth. However, the associations heretofore drawn between lower mantle structure and past subduction have been qualitative and conflicting, so the very assumption of a correlation has yet to be quantitatively corroborated. Here we show that a significant, time-depth progressive correlation can be drawn between reconstructed subduction zones of the last 130 Myr and positive S wave velocity anomalies at 600 -2300 km depth, but that further correlation between greater times and depths is not presently demonstrable. This correlation suggests that lower mantle slab sinking rates average between 1.1 and 1.9 cmyr 1.
DS201808-1752
2018
Domeier, M.Hosseini, K., Mathews, K.J., Sigloch, K., Shephard, G.E., Domeier, M., Tsekhmistrenko, M.SubMachine: web based tools for exploring seismic tomography and other models of Earth's deep interior.Geochemistry, Geophysics, Geosystems, Vol. 19, 5, pp. 1464-1483.Mantlegeophysics - seismic

Abstract: SubMachine is a collection of web-based tools for the interactive visualisation, analysis, and quantitative comparison of global-scale, volumetric (3-D) data sets of the subsurface, with supporting tools for interacting with other, complementary models and data sets as listed below. In short, SubMachine is a computational engine (Machine) to visualize models and datasets of the sub-surface (Sub).
DS201902-0269
2019
Domeier, M.Domeier, M., Torsvik, T.H.Full plate modelling in pre-Jurassic time.Geological Magazine, Vol. 156, 2, pp. 261-280.Mantleplate tectonics

Abstract: A half-century has passed since the dawning of the plate tectonic revolution, and yet, with rare exception, palaeogeographic models of pre-Jurassic time are still constructed in a way more akin to Wegener's paradigm of continental drift. Historically, this was due to a series of problems - the near-complete absence of in situ oceanic lithosphere older than 200 Ma, a fragmentary history of the latitudinal drift of continents, unconstrained longitudes, unsettled geodynamic concepts and a lack of efficient plate modelling tools - which together precluded the construction of plate tectonic models. But over the course of the last five decades strategies have been developed to overcome these problems, and the first plate model for pre-Jurassic time was presented in 2002. Following on that pioneering work, but with a number of significant improvements (most notably longitude control), we here provide a recipe for the construction of full-plate models (including oceanic lithosphere) for pre-Jurassic time. In brief, our workflow begins with the erection of a traditional (or ‘Wegenerian’) continental rotation model, but then employs basic plate tectonic principles and continental geology to enable reconstruction of former plate boundaries, and thus the resurrection of lost oceanic lithosphere. Full-plate models can yield a range of testable predictions that can be used to critically evaluate them, but also novel information regarding long-term processes that we have few (or no) alternative means of investigating, thus providing exceptionally fertile ground for new exploration and discovery.
DS1982-0571
1982
Domeneghetti, C.Smith, D.C., Domeneghetti, C., Rossi, G., Ungararetti, L.Single Crystal Structure Refinements of Super Silicic Clinopyroxenes from the Zagadochnaya Kimberlite Pipe, Yakutia, Ussr.Proceedings of Third International Kimberlite Conference, TERRA COGNITA, ABSTRACT VOLUME., Vol. 2, No. 3, P. 223, (abstract.).RussiaKimberlite, Microprobe, Chemistry
DS1984-0228
1984
Domeneghetti, C.Del negro, A., Carbonin, S., Domeneghetti, C., Molin, G.M.Crystal Chemistry and Evolution of the Clinopyroxene in a SuContributions to Mineralogy and Petrology, Vol. 86, No. 3, PP. 221-229.AustraliaRelated Rocks
DS201507-0326
2015
Domeneghetti, M.C.Milani, S., Nestola, F., Alvaro, M., Pasqual, D., Mazzucchelli, M.L., Domeneghetti, M.C., Geiger, C.A.Diamond -garnet geobarometry: the role of garnet compressibility and expansivity.Lithos, Vol. 227, pp. 140-147.TechnologyGeobarometry
DS201610-1891
2016
Domeneghetti, M.C.Nestola, F., Alvaro, M., Casati, M.N., Wilhelm, H., Kleppe, A.K., Jephcoat, A.P., Domeneghetti, M.C., Harris, J.W.Source assemblage types for cratonic diamonds from x-ray synchroton diffraction.Lithos, in press available 5p.RussiaDeposit - Udachnaya
DS201908-1797
2019
Domeneghetti, M.C.Murri, M., Smith, R.L., McColl, K., Hart, M., Alvaro, M., Jones, A.P., Nemeth, P., Salzmann, C.G., Cora, F., Domeneghetti, M.C., Nestola, F., Sobolev, N.V., Vishnevsky, S.A., Logvinova, A.M., McMillan, P.F.Quantifying hexagonal stacking in diamond. ( lonsdaleite)Nature Scientific Reports, doi.org/10.1038/ s41598-019-46556-3 8p. PdfGlobaldiamond morphology, impact craters

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

Abstract: Diamond is a material of immense technological importance and an ancient signifier for wealth and societal status. In geology, diamond forms as part of the deep carbon cycle and typically displays a highly ordered cubic crystal structure. Impact diamonds, however, often exhibit structural disorder in the form of complex combinations of cubic and hexagonal stacking motifs. The structural characterization of such diamonds remains a challenge. Here, impact diamonds from the Popigai crater were characterized with a range of techniques. Using the MCDIFFaX approach for analysing X-ray diffraction data, hexagonality indices up to 40% were found. The effects of increasing amounts of hexagonal stacking on the Raman spectra of diamond were investigated computationally and found to be in excellent agreement with trends in the experimental spectra. Electron microscopy revealed nanoscale twinning within the cubic diamond structure. Our analyses lead us to propose a systematic protocol for assigning specific hexagonality attributes to the mineral designated as lonsdaleite among natural and synthetic samples.
DS1989-0364
1989
Domergue, C.Domergue, C., Fontan, F., Herail, G.Les techniques artisanales d'exploitation des gites alluviaux: analogies dans le temps et dans l'espaceChron. Rech. Min., (in French), No. 497, pp. 131-138GlobalPlacers, Mining technology -alluvials
DS1990-0411
1990
Domergue, C.Domergue, C., Fontan, F., Herail, G.Les techiques artisanales d'exploitation des gitesalluviaux: analogies dans le temps et dans l'espace. (in French)Chron. Rech. Min., (in French), No. 497, pp. 131-138GlobalAlluvials, Placer mining
DS201112-0280
2011
Dominguez, A.R.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
DS1992-0373
1992
Dominguez, J.M.L.Dominguez, J.M.L.Sequence stratigraphy applied to Precambrian terrains: examples for the State of Bahia.(in Portugese).Revista Brasileira de Geociencas, (in Portugese)., Vol. 22, No. 4, Dec. pp. 422-436BrazilStratigraphy, Precambrian
DS1989-0237
1989
Dominh, K.Cazenave, A., Souriau, A., Dominh, K.Global coupling of earth surface topography with hotspots, geoid and mantleheterogeneitiesNature, Vol. 340, No. 6228, July 6, pp. 54-57GlobalMantle, Hotspots
DS200512-0769
2005
Dominiak, P.Natarajam, R., Savitha, G., Dominiak, P., Wozniak, K., Moorthy, J.N.Corundum, diamond and PtS metal organic frameworks with a difference: self assembly of a unique pair of 3-connecting D2d symmetric 3,3',5,5' tetrakis(4-pyridyl)bimesity1.Angewandie Chemie, Vol. 44, 14, March 29, pp. 2115-2119.Chemistry - framework
DS1994-0441
1994
Dominic, J.B.Dominic, J.B., McConnell, D.A.The influence of structural lithic units in fault related folds, SeminoeMountains, WyomingJournal of Structural Geology, Vol. 16, No. 6, pp. 769-780WyomingStructure, Seminoe area
DS1975-0729
1978
Dominion Mining NlDominion Mining NlEl 1002, Bingara Exploration Reports, DiamondsNew South Wales Open File., No. GS 1978-355, 16P. 2 MAPS, UNPUBL.Australia, New South WalesDiamonds, Bingara, Exploration, Prospecting
DS2003-0344
2003
Dominy, S.Dominy, S., Annels, A.Core recovery for mineral resource estimation - some considerationsEgru Newsletter, April pp. 6-9.GlobalMineral resources - not specific to diamonds
DS200412-0467
2003
Dominy, S.Dominy, S., Annels, A.Core recovery for mineral resource estimation - some considerations.Economic Geology Research Institute, April pp. 6-9.TechnologyMineral resources - not specific to diamonds
DS2003-0020
2003
Dominy, S.C.Annels, A.E., Dominy, S.C.Core recovery and quality: important factors in mineral resource estimation. ( goldApplied Earth Science Transactions Institute Mining and Metallurgy, Vol. 112, Dec. pp. B 305-312.GlobalBlank
DS200412-0042
2003
Dominy, S.C.Annels, A.E., Dominy, S.C.Core recovery and quality: important factors in mineral resource estimation. ( gold related)Applied Earth Science Transactions Institute of Mining and Metallurgy, Vol. 112, Dec. pp. B 305-312.TechnologyEconomics - resource estimation - not specific to diamo
DS200412-0468
2004
Dominy, S.C.Dominy, S.C., Noppe, M.A., Annels, A.E.Errors and uncertainty in mineral resource and ore reserve estimation: the importance of getting it right.Exploration and Mining Geology, Vol.11,1-4,Jan-Oct.2002, publ. Apr. 29,2004 pp. 77-98TechnologyEvaluation - not specific to diamonds
DS201508-0382
2015
Dominy, S.C.Xie, Y., Li, Y., Hou, Z., Cooke, D.R., Danyushevsky, L., Dominy, S.C., Yin, S.A model for carbonatite hosted REE mineralization - the Mianning-Dechang REE belt, western Sichuan Province, China.Ore Geology Reviews, Vol. 70, pp. 595-612.ChinaCarbonatite
DS1990-1493
1990
Domoney, R.N.Van Bever Donker, J.M., Humphreys, H.C., Swartz, H.G., Domoney, R.N.The history of deformation along the boundary between an Archean craton And a Proterozoic island arcTerra, Abstracts of Crustal Dynamics: Pathways and Records held Bochum FRG, Vol. 2, December p. 20South AfricaCraton -Kaapvaal, Tectonics
DS201706-1095
2017
Domrois, S.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.
DS1989-0365
1989
Donahoe, J.L.Donahoe, J.L., Green, N.L., Fang, Jen-HoAn expert system for idenification of minerals in thin sectionJournal of Geology Education, Vol. 37, No. 1, pp. 4-6. Database # 17586GlobalGIS - Mineralogy, Computer- Expert system
DS201212-0166
2012
Donahue, P.H.Donahue, P.H., Simonetti, A., Neal, C.R.Chemical characteristics of natural ilmenite: a possible new reference material.Geostandards and Geoanalytical Research, Vol. 36, 1, pp. 61-73.Asia, Solomon IslandsMalaita alnoite pipes
DS2001-0213
2001
DonaldsonCousens, B.L., Aspler, L.B., Chiarenzelli, DonaldsonEnriched Archean lithospheric mantle beneath western Churchill province tapped during Paleoproterozoic ..Geology, Vol. 29, No. 9, Sept. pp. 827-30.Northwest Territories, Saskatchewan, AlbertaOrogenesis
DS1970-0669
1973
Donaldson, C.Donaldson, C., Reid, A.M., Ridley, W.I.The Igwisi Hills Extrusive Kimberlites1st International Kimberlite Conference, EXTENDED ABSTRACT VOLUME, PP. 93-94.Tanzania, East AfricaGeology
DS1975-0168
1975
Donaldson, C.Reid, A.M., Donaldson, C., Dawson, J.B., Brown, R.W.The Igwisi Hills Extrusive KimberlitePhysics and Chemistry of the Earth., Vol. 9, PP. 199-218.Tanzania, East AfricaGeology
DS1975-0169
1975
Donaldson, C.H.Reid, A.M., Donaldson, C.H., Brown, R.W., Ridley, R.I., Dawson.Mineral Chemistry of Peridotite Xenoliths from the Lashainevolcano, Tanzania.Physics and Chemistry of the Earth., Vol. 9, PP. 525-544.Tanzania, East AfricaMineral Chemistry
DS1982-0179
1982
Donaldson, C.H.Donaldson, C.H., Reid, A.M.Multiple Intrusion in a Kimberlite DykeGeological Society of South Africa Transactions, Vol. 85, No. 1, PP. 1-12.South AfricaDe Beers, Kimberley Area, Kimberlite Pipe And Deposit, Petrogra
DS1984-0239
1984
Donaldson, C.H.Donaldson, C.H.Kinetics of Pyrope Megacryst Reactions in Ascending Basaltic Magma- Relevance to High Pressure Magmatic Crystallization at Leie Ness, East Fife.Geological Magazine., Vol. 121, No. 6, PP. 615-620.ScotlandPetrology, Petrogenesis
DS1984-0469
1984
Donaldson, C.H.Mackenzie, W.S., Donaldson, C.H., Guilford, C.Kimberlite and Garnet PeridotiteAtlas of Igneous Rocks And Their Textures, J.wiley- Halstead, 148P. PP. 81-82.GlobalPhotomicrographs
DS1986-0189
1986
Donaldson, C.H.Donaldson, C.H.The rate of dissolution of olivine, plagioclase and quartz in a basaltmeltMineralogical Magazine, Vol. 49, No. 354, pp. 683-694GlobalBlank
DS1987-0157
1987
Donaldson, C.H.Donaldson, C.H., Dawson, J.B., Kanaris-Sotiriou, R., BatchelorThe silicate lavas of Oldoinyo Lengai, TanzaniaNeus Jahrb. Min. Abhandl, Vol. 156, No. 3, pp. 247-279TanzaniaPetrology
DS1987-0158
1987
Donaldson, C.H.Donaldson, C.H., Hamilton, D.L.Compositional convection and layering in a rock meltNature, Vol. 327, No. 6121, June 4, pp. 413-415GlobalPicrite, Alkaline rocks
DS1996-1274
1996
Donaldson, C.H.Seedhouse, J.K., Donaldson, C.H.Compositional convection caused by olivine crystallization in a synthetic basalt melt.Mineralogical Magazine, Vol. 60, pp. 115-30.MantleMagma chambers
DS201012-0481
2010
Donaldson, C.H.McCreath, J.A., Finch, A.A., Donaldson, C.H., Armour-Brown, A.The petrology and petrogenesis of one of the world's biggest Ta deposits - the Motzfeldt Centre, South Greenland.International Workshop Geology of Rare Metals, held Nov9-10, Victoria BC, Open file 2010-10, extended abstract pp.43.Europe, GreenlandAlkalic
DS2001-0212
2001
Donaldson, et al.Cousens, B.L., Aspler, Chiarenzelli, Donaldson, et al.Enriched Archean lithosphere mantle beneath western Churchill Province tapped during PaleoproterozoicGeology, Vol. 29, No. 9, Sept. pp. 827-30.Alberta, Manitoba, Saskatchewan, Northwest TerritoriesLamprophyres, minettes, Hearn, Metasomatism, subduction, orogenesis
DS1994-1250
1994
Donaldson, J.A.Mueller, W., Donaldson, J.A., Doucet, P.Volcanic and tectono-plutonic influences on sedimentation in the Archean Kirkland Basin, AbitibiPrecambrian Research, Vol. 68, No. 3-4, August pp. 201-230OntarioGreenstone belt -Abitibi, Tectonics
DS2003-1123
2003
Donaldson, J.A.Rainbird, R.H., Hadlari, T., Aspler, L.B., Donaldson, J.A., Le Cheminant, A.N.Sequence stratigraphy and evolution of the Paleoproterozoic intracontinental BakerPrecambrian Research, Vol. 125, 1-2, pp. 21-53.NunavutBlank
DS200412-1609
2003
Donaldson, J.A.Rainbird, R.H., Hadlari, T., Aspler, L.B., Donaldson, J.A., Le Cheminant, A.N., Peterson, T.D.Sequence stratigraphy and evolution of the Paleoproterozoic intracontinental Baker Lake and The lon Basins, western Churchill ProPrecambrian Research, Vol. 125, 1-2, pp. 21-53.Canada, NunavutGeology
DS201212-0262
2012
Donaldson, S.G.Grimwood, B.S.R., Doubleday, N.C., Ljubicic, G.J., Donaldson, S.G., Blangy, S.Engaged acclimatization: towards responsible community based participatory research in Nunavut.Canadian Geographer, in press availableCanada, NunavutCSR - neologism
DS201812-2802
2018
Donati-Filho, J.P.Donati-Filho, J.P.A new geological model, facies recognition and terminology of the Brauna kimberlite field, Bahia - Brazil.7th Symposio Brasileiro de Geologia do Diamante , Title only South America, Brazil, Bahiadeposit - Brauna
DS1992-0374
1992
Donato, D.A.Donato, D.A.MULSIM/PC - a personal computer based structural analysis program for mine design in deep tabular depositsUnited States Bureau of Mines Information Circular, No. 9325, 56pUnited StatesComputer, Program -MULSIM/PC.
DS1989-0366
1989
Donato, M.M.Donato, M.M.Metamorphism of an ophiolitic tectonic melange,northern California Klamath Mountains, USAJournal of Metamorphic Geology, Vol. 7, pp. 515-528. Database # 18179CaliforniaOphiolite, metamorphism
DS201112-0281
2010
Donatti Filho, J.P.Donatti Filho, J.P., Paiva de Oliveira, E., Tappeb, S., Heaman, L.U Pb TIMS perovskite dating of the Brauna kimberlite field, Sao Francisco craton - Brazil: constraints on Neoproterozoic alkaline magmatism.5th Brasilian Symposium on Diamond Geology, Nov. 6-12, abstract p. 81.South America, BrazilGeochronology
DS201412-0200
2014
Donatti Filho, J.P.Donatti Filho, J.P., Schobbenhaus, C.Kimberlito Brauna 3: petrolgia e modelagem geologica do teor diamantifero.6 Simposio Brasileiro de Geologia do Diamante, Aug. 3-7, 1p. AbstractSouth America, BrazilDeposit - Brauna
DS201312-0223
2013
Donatti-Filho, J.P.Donatti-Filho, J.P., Tappe, S., Oliveira, E.P., Heaman, L.M.Age and origin of Neoproterozoic Brauna kimberlitic melt generation with the metasomatized base of Sao Francisco craton, BrazilChemical Geology, Vol. 353, pp. 19-35.South America, BrazilGeochronology, geochemistry (kimberlites and orangeites)
DS201312-0224
2013
Donatti-Filho, J.P.Donatti-Filho, J.P., Oliviera, E.P., McNaughton, N.J.Provenance of zircon xenocrysts in the Neoproterozoic Brauna kimberlite field, Sao Francisco Craton, Brazil: evidence for a thick Paleoproterozoic lithosphere beneath the Serrinha block.Journal of South American Earth Sciences, Vol. 45, pp. 83-96.South America, BrazilDeposit - Brauna
DS201412-0201
2014
Donatti-Filho, J.P.Donatti-Filho, J.P., Schobbenhaus, C.N.Brauna project Brazil: the first kimberlite diamond mine in Latin America.GSSA Kimberley Diamond Symposium and Trade Show provisional programme, Sept. 12, title onlySouth America, BrazilDeposit - Brauna
DS201412-0632
2014
Donatti-Filho, J.P.Nishijima, P.S.T., Donatti-Filho, J.P., Svizzero, D., Oliveira, E.P.de.Petrografia e geoquimica do kimberlito Forca, provincia ignea do alto Paranaiba, M.G.6 Simposio Brasileiro de Geologia do Diamante, Aug. 3-7, 1p. AbstractSouth America, Brazil, Minas GeraisDeposit - Forca
DS201412-0633
2014
Donatti-Filho, J.P.Nishijima, P.S.T., Donatti-Filho, J.P., Svizzero, D., Oliveira, E.P.de.Petrografia e geoquimica da intrusao lamproitica provincia ignea do alto Paranaiba, Minas Gerais. 6 Simposio Brasileiro de Geologia do Diamante, Aug. 3-7, 1p. AbstractSouth America, Brazil, Minas GeraisLamproite
DS1982-0446
1982
Doncan, A.R.Moore, A.E., Erlank, A.J., Doncan, A.R.The Evolution of Olivine Melilitite and Kimberlite MagmasProceedings of Third International Kimberlite Conference, TERRA COGNITA, ABSTRACT VOLUME., Vol. 2, No. 3, P. 214, (abstract.).South AfricaKimberlite, Namaqualand, Bushmanland, Sr, Isotope, Garies, Chemistry
DS201606-1078
2016
Donchak, P.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.
DS1910-0526
1917
Dondero, C.Dondero, C.El Dorado in the Early SixtiesEldorado Republican And Weekly Nugget., Feb. 2ND.United States, California, West CoastBlank
DS201212-0021
2012
Dondi, M.Ardit, M., Dondi, M., Merlini, M., Cruciani, G.Melilite-type and melilite related compounds: structural variations along the join Sr2a, Bax, MgS2iO7 and high pressure behaviour of the two end members.Physics and Chemistry of Minerals, Vol. 39, 3, pp.199-211.TechnologyMelilite
DS1990-0747
1990
Donelick, R.A.Issler, D.R., Beaumont, C., Willett, S.D., Donelick, R.A., MooersPreliminary evidence from apatite fission track dat a concerning the thermal history of the Peace River Arch region, western Canada sedimentary basinGeology of the Peace River Arch, ed. Sc.C. O'Connell, J.S. Bell, Bulletin. Can., Vol. 38A, Special Volume, December pp. 260-269AlbertaGeochronology, Geothermometry
DS2003-1155
2003
Donelick, R.A.Reiners, P.W., Zhou, Z., Ehlers, T.A., Xu, C., Brandon, M.T., Donelick, R.A.Post orogenic evolution of the Dabie Shan, eastern Chin a ( U Th) He and fission trackAmerican Journal of Science, Vol. 303, 6, pp. 489-518.ChinaGeothermometry, UHP
DS200412-1652
2003
Donelick, R.A.Reiners, P.W., Zhou, Z., Ehlers, T.A., Xu, C., Brandon, M.T., Donelick, R.A., Nicolescu, S.Post orogenic evolution of the Dabie Shan, eastern Chin a ( U Th) He and fission track thermochronology.American Journal of Science, Vol. 303, 6, pp. 489-518.ChinaGeothermometry UHP
DS1994-1990
1994
DongZhenin, DongIndicator minerals for diamond in kimberlites9th. IAGOD held Beijing, Aug.12-18., Vol. 1, p. 267-268. abstractChinaDiamond genesis
DS200812-0674
2008
Dong, C.Liu, D., Wilde, S.A, Wan, Y., Wu, J., Zhou, H., Dong, C., Yin, X.New U Pb and Hf isotopic dat a confirm Anshan as the oldest preserved segment of the North Chin a Craton.American Journal of Science, Vol. 308, 3, pp. 200-231.ChinaGeochronology
DS200812-1232
2008
Dong, C.Wan, Y., Liu, D., Wilde, S., Nutman, A., Dong, C., Wang, W.The oldest rocks and zircons in China.Goldschmidt Conference 2008, Abstract p.A994.ChinaAnshan City
DS1984-0322
1984
Dong, C.Y.Grinson, A.S., Dong, C.Y.Kimberlite Magmatism and the Chin a Platform Lithosphere Structure.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 276, No. 4, PP. 920-923.Russia, ChinaTectonics, Genesis
DS2003-0004
2003
Dong, D.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
DS200412-0009
2003
Dong, D.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
DS200812-0488
2008
Dong, F.Huang, F., li, S., Dong, F., He, Y., Chen, F.High mag adakitic rocks in the Dabie orogen, central China: implications for foundering mechanisms of lower continental crust.Chemical Geology, Vol. 255, 1-2, Sept. 30, pp. 1-13.ChinaUHP
DS200812-1300
2008
Dong, G.Yu, X., Zhao, Z., Mo, X., Dong, G.Cenozoic alkaline and carbonatitic magmatism in northeastern Tibetan Plateau: implications for mantle plume.Goldschmidt Conference 2008, Abstract p.A1065.Asia, TibetCarbonatite
DS201412-0517
2014
Dong, G.Liu, D., Zhao, Z., Zhu, D-C., DePaolo, D.J., Harrison, T.M., Mo, X., Dong, G., Zhou, S., Sun, C., Zhang, Z., Liu, J.Post collisional potassic and ultrapotassic rocks in southern Tibet: mantle and crustal origins in response to India-Asia collision and convergence.Geochimica et Cosmochimica Acta, Vol. 143, pp. 207-231.Asia, TibetAlkalic
DS201412-0911
2014
Dong, J.Tang, X., Ntam, M.C., Dong, J., Rainey, E.S., Kavner, A.The thermal conductivity of Earth's lower mantle.Geophysical Research Letters, Vol. 41, 8, pp. 2746-2752.MantleGeothermometry
DS201412-0912
2014
Dong, J.Tang, X., Ntam, M.C., Dong, J., Rainey, E.S.G., Kavner, A.The thermal conductivity of Earth's lower mantle.Geophysical Research Letters, Apr. 16 DOI: 10.1002/2014 GL059385MantleGeothermometry
DS201412-0913
2014
Dong, J.Tang, X., Ntam, M.C., Dong, J., Rainey, E.S.G., Kavner, A.The thermal conductivity of Earth's lower mantle.Geophysical Research Letters, April 16, pp. 2746-2742.MantleGeothermometry
DS201412-0914
2014
Dong, J.Tang, X., Ntam, M.C., Dong, J., Rainey, E.S.G., Kavner, A.The thermal conductivity of Earth's lower mantle.Geophysical Research Letters, Vol. 41, 8, pp. 2746-2752.MantleGeothermometry
DS201709-2021
2017
Dong, J.Li, J., Xhu, F., Dong, J., Liu, J., LaI, X., Chen, B., Meng, Y.Experimental investigations into the fate of subducted carbonates and origin of super deep diamonds.Goldschmidt Conference, abstract 1p.Mantlepetrology

Abstract: Carbonates are common rock-forming minerals in the Earth’s crust and act as sinks of atmospheric carbon dioxide. Subduction of hydrothermally altered oceanic lithosphere returns carbon to the interior, where more than three quarters of Earth’s carbon is stored. The contribution of subducted carbonates to the Earth's long-term deep carbon cycle is uncertain and has recently emerged as a topic of intense debate [1]. Moreover, mantle-slab interaction has been proposed as a mechanism to produce super-deep diamonds, thus questioning the use of certain mineral inclusions to infer lower-mantle origin [2]. Here we report new data on the chemical stability and reaction kinetics of carbonates in the mantle from multianvil and diamond-anvil-cell experiments. Our results suggest that carbon can be sequestered into deep Earth through reaction freezing and that the index minerals for super-deep diamonds are not reliable indicators for their formation depths.
DS201908-1821
2019
Dong, J.Wang, C., Song, S., Wei, C., Su, L., Allen, M.B., Niu, Y., Li, X-H., Dong, J.Paleoarchean deep mantle heterogeneity recorded by enriched plume remnants.Nature Geoscience, doi.org/10.1038/s41561-019-0410-y 10p pdfMantlePlumes, hotspots

Abstract: The thermal and chemical state of the early Archaean deep mantle is poorly resolved due to the rare occurrences of early Archaean magnesium-rich volcanic rocks. In particular, it is not clear whether compositional heterogeneity existed in the early Archaean deep mantle and, if it did, how deep mantle heterogeneity formed. Here we present a geochronological and geochemical study on a Palaeoarchaean ultramafic-mafic suite (3.45-Gyr-old) with mantle plume signatures in Longwan, Eastern Hebei, the North China Craton. This suite consists of metamorphosed cumulates and basalts. The meta-basalts are iron rich and show the geochemical characteristics of present-day oceanic island basalt and unusually high mantle potential temperatures (1,675?°C), which suggests a deep mantle source enriched in iron and incompatible elements. The Longwan ultramafic-mafic suite is best interpreted as the remnants of a 3.45-Gyr-old enriched mantle plume. The first emergence of mantle-plume-related rocks on the Earth 3.5-3.45?billion years ago indicates that a global mantle plume event occurred with the onset of large-scale deep mantle convection in the Palaeoarchaean. Various deep mantle sources of these Palaeoarchaean mantle-plume-related rocks imply that significant compositional heterogeneity was present in the Palaeoarchaean deep mantle, most probably introduced by recycled crustal material.
DS1999-0419
1999
Dong, S.Liu, X., Dong, S., Xue, H., Zhou, J.Significance of allanite ( Ce) in granitic gneisses from the ultrahigh pressure metamorphic terrane...Mineralogical Magazine, Vol. 63, No. 4, Aug. pp. 579-86.Chinametamorphism, Dabie Shan area
DS2000-0868
2000
Dong, S.Schmid, J.C., Ratschibacher, L., Dong, S.How did the foreland react? Yangtze foreland fold and thrust belt deformation related to exhumation of DabieáShanTerra Nova, Vol. 11, No. 6, pp. 266-72.China, eastern Chinaultra high pressure (UHP) - Dabie Shan, Continental crust
DS200412-1163
2004
Dong, S.Liu, X., Wei, C., Li, S., Dong, S., Liu, J.Thermobaric structure of a traverse across western Dabie Shan: implications for collision tectonics between the Sino-Korean andJournal of Metamorphic Geology, Vol. 22, 4, pp. 361-379.ChinaUHP, geothermobarometry
DS200512-0242
2005
Dong, S.Dong, S., Gao, R., Cong, B., Zhao, Z., Liu, X., Li, S., Huang, D.Crustal structure of the southern Dabie ultrahigh pressure orogen and Yangtze foreland from deep seismic reflection profiling.Terra Nova, Vol. 16, 6, Dec. pp. 319-324.ChinaUHP, tectonics
DS200512-0650
2004
Dong, S.Liu, X., Jah, B., Liu, D., Dong, S., Li, S.SHRIMP U-Pb zircon dating of a metagabbro and eclogites from western Dabie Shan ( Hong'an Block) Chin a and its tectonic implications.Tectonophysics, Vol. 394, 3-4, Dec. 1-, pp. 171-192.ChinaGeochronology, UHP
DS200612-1130
2006
Dong, S.Ratschbacher, L., Franz, L., Enkelmann, E., Jonckheere, R., Porschke, A., Hacker, B.R., Dong, S., Zhang, Y.The Sino-Korean Yangtze suture, the Huwan detachment and the Paleozoic Tertiary exhumation of ultra high pressure rocks along the Tongbai Xinxian Dabie Mtns.Geological Society of America, Special Paper, No. 403, pp. 45-76.ChinaUHP
DS200612-1512
2006
Dong, S.Wawrzenitz, N., Romer, R.L., Oberhansli, R., Dong, S.Dating of subduction and differential exhumation of UHP rocks fromn the Central Dabie Complex ( E-China): constraints from microfabrics, Rb-Sr and U-Pb isotope systems.Lithos, in press,ChinaGeochronology, UHP
DS201903-0518
2018
Dong, S.Huang, W., Liu, Y., Dong, S., Chao, D.Nominal type IaB diamond with detectable uncompensated boron. FTIRGems & Gemology, Vol. 54, 4, pp. 454-455.Globaldiamond mineralogy

Abstract: n recent years, nominal type IaAB and IIa diamonds with transient 2800 cm-1 FTIR absorption peaks arising from uncompensated boron produced under UV radiation have been reported (J. Li et al., A diamond with a transient 2804 cm-1 absorption peak, Journal of Gemmology, Vol. 35, 2016, pp. 248-252; Winter 2016 Lab Notes, pp. 412-413). The National Center of Supervision and Inspection on Quality of Gold and Silver Products recently examined a type IaB diamond that exhibited instantaneous 2803 cm-1 FTIR absorption shortly after exposure to an ultra-short-wave (< 230 nm) UV source.
DS200812-0290
2008
Dong, S.W.Dong, S.W., Li, Q.S., Gao, R., Liu, F.T., Liu, X.C., Xue, H.M., Guan, Y.Moho mapping in the Dabie ultrahigh pressure collisional orogen, central China.American Journal of Science, Vol. 308, 4, pp. 517-528.ChinaUHP
DS201112-1164
2011
Dong, X.Zhang, Z.M., Dong, X., Liou, J.G., Liu, F., Wang, W., Yui, F.Metasomatism of garnet periodite from Jiangzhuang, Sulu UHP belt: constraints on the interactions between crust and mantle rocks during subduction of cont. lithosphereJournal of Metamorphic Geology, in press availableChinaUHP
DS201112-1165
2011
Dong, X.Zhang, Z.M., Dong, X., Liou, J.G., Liu, F., Wang, W., Yui, F.Metasomatism of garnet peridotite from Jiangzhuang, southern Sulu UHP belt: constraints on the interactions between crust and mantle rocks during subduction of continentalJournal of Metamorphic Geology, Vol. 29, 9, pp. 917-937.ChinaUHP
DS201112-1166
2011
Dong, X.Zhang, Z.M., Shen, K., Liou, J.G., Dong, X., Wang, W., Yu, F., Liu, F.Fluid rock interactions during UHP metamorphism: a review of the Dabie Sulu orogen, east-central China.Journal of Asian Earth Sciences, Vol. 42, 3, pp. 316-329.ChinaUHP
DS201212-0820
2012
Dong, X.Zhang, Z.M., Shen, K., Liou, J.G., Dong, X., Wang, W., Yu, F., Liu, F.Fluid rock interactions during UHP metamorphism: a review of the Dabie-Sulu orogen, east central China.Journal of Asian Earth Sciences, Vo. 43, 3, pp. 316-329.ChinaUHP
DS1996-0373
1996
Dong, Z.Dong, Z.Garnets in basalts and their comparison with those in kimberlitesInternational Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 388.ChinaKimberlites, Mineralogy -garnets
DS1996-0374
1996
Dong, Z.Dong, Z.Spinels of mantle xenoliths in basalts and their comparison with those ofkimberlites.International Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 388.ChinaXenoliths, Kimberlites
DS1997-0283
1997
Dong, Z.Dong, Z., Taylor, L.A., Dong-HwaPyropes from China: peridotite xenoliths from kimberlites versus megacrysts in basalts.International Geology Review, Vol. 39, No. 2, Feb. pp. 141-150.ChinaKimberlites, Xenoliths
DS1995-0432
1995
Dong BiDong Bi, Morton, R.D.Magnetic spherules from Recent fluvial sediments in Alberta, Canada:characteristics and possible originsCanadian Journal of Earth Sciences, Vol. 32, No. 4, April pp. 351-358AlbertaSpherules - meteor, extraterrestrial
DS1992-0375
1992
Dong henxinDong henxin, Shen Meidong, Ke Jie, Wang BingxiSpinels of mantle xenoliths in Cenozoic basalts from eastern ChinaInternational Symposium Cenozoic Volcanic Rocks Deep seated xenoliths China and its, Abstracts pp. 56-57ChinaMantle, Xenoliths
DS1990-0412
1990
Dong ZhenxinDong ZhenxinClinopyroxenes from kimberlites in ChinaInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 2, extended abstract p. 792-794ChinaClinopyroxenes, Kimberlites
DS1990-0413
1990
Dong ZhenxinDong Zhenxinchromium-spinels from kimberlites and other rocksInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 2, extended abstract p. 794-795ChinaKimberlites, chromium-spinels
DS1990-0414
1990
Dong ZhenxinDong ZhenxinIlmenites in kimberlites from ChinaInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 2, extended abstract p. 795-796ChinaKimberlites, Ilmenites
DS1990-0415
1990
Dong ZhenxinDong ZhenxinPyropes of kimberlites from ChinaInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 2, extended abstract p. 796-798ChinaKimberlites, Pyropes
DS1990-1588
1990
Dong ZhenxinWu Gongbao, Dong ZhenxinMossbauer study of chromites in kimberlites and its geologicalsignificanceInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 1, extended abstract p. 461-463ChinaMineralogy -chromites, Kimberlites
DS1991-0390
1991
Dong ZhenxinDong ZhenxinGeochemistry of kimberlites in China.*CHIChinese Academy of Geological Sciences Bulletin, *CHI, Vol. 23, pp. 99-114ChinaGeochemistry, Ultramafics
DS1991-0391
1991
Dong ZhenxinDong ZhenxinSome geological characteristics of kimberlite type diamond deposits in Chin a and their ore prospecting indicators.*CHIMineral Deposits, K'Uang Ch'uang Ti Chih**CHI, Vol. 10, No. 5, pp. 255-264ChinaKimberlite, Indicator minerals
DS1991-0392
1991
Dong ZhenxinDong ZhenxinMicas in kimberlites from ChinaProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 470-472ChinaMineral chemistry, Classification of micas-phlogopite
DS1991-0393
1991
Dong ZhenxinDong ZhenxinOlivines in Shandong kimberlitesProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 473-474ChinaMineral chemistry, Diamond inclusions
DS1991-0394
1991
Dong ZhenxinDong ZhenxinCharacteristics of chromium-spinels in kimberlites and their comparison With those in other rocks.*CHIDizhi Lunping (Geological Review) *CHI, Vol. 37, No. 6, pp. 508-517ChinaPetrology, Kimberlites, ultramafics
DS1992-0376
1992
Dong ZhenxinDong ZhenxinThe study of petrology and geochemistry of kimberlites from ChinaProceedings of the 29th International Geological Congress. Held Japan August 1992, Vol. 2, abstract p. 577ChinaKimberlite
DS1992-0377
1992
Dong ZhenxinDong ZhenxinClinopyroxenes in kimberlites of ChinaActa Geologica Sinica, Vol. 5, No. 3, September pp. 259-270ChinaKimberlites, Geochemistry, clinopyroxenes
DS1992-0378
1992
Dong ZhenxinDong ZhenxinMantle xenoliths in kimberlites from ChinaProceedings of the 29th International Geological Congress. Held Japan August 1992, Vol. 1, abstract p. 178ChinaKimberlites, Xenoliths
DS1993-0367
1993
Dong ZhenxinDong Zhenxin, Cong Andong, Han Zhuguo, H.Mineralogical criteria for determination of diamond content in kimberlites.*CHIMineral Deposits *CHI, Vol.12, No. 1, pp. 48-54ChinaMineral chemistry, Indicator minerals
DS1980-0114
1980
Dong zhenxin, ZHOU JIANXIONG.Dong zhenxin, ZHOU JIANXIONG.The Typomorphic Characteristics of Chromites from Kimberlites in Chin a and Their Significance in Exploration of Diamonddeposits.Acta Geol. Sinica., Vol. 54, No. 4, PP. 284-299.ChinaProspecting Chang Ma Chuan, Tou Tau Ko, Yeh Chi, Ming Chuan Wan
DS1986-0310
1986
Dong ZunyingGrinson, A.S., Dong ZunyingKimberlite volcanism and structure of lithosphere on the ChineseSOURCE[ Doklady Academy of Science USSR, Earth Science SectionDoklady Academy of Science USSR, Earth Science Section, Vol. 276, January, No. 1-6, pp. 64-66ChinaDistribution, Tectonics
DS1998-0999
1998
Dong-DingMeyers, J.B., Rosendahl, B.R., Harrison, C., Dong-DingDeep imaging seismic and gravity results from the offshore Cameroon Volcanic Line and African hotlines.Tectonophysics, Vol. 284, No. 1-2, Jan. 15, pp. 31-63.West Africa, Sierra LeoneGeophysics - seismics, Mantle convection, Craton
DS1997-0283
1997
Dong-HwaDong, Z., Taylor, L.A., Dong-HwaPyropes from China: peridotite xenoliths from kimberlites versus megacrysts in basalts.International Geology Review, Vol. 39, No. 2, Feb. pp. 141-150.ChinaKimberlites, Xenoliths
DS200612-0343
2005
Dongre, A.Dongre, A., Kamde, G., Chalapathi Rao, N.V., Kale, H.S.Is megacrystic/xenocrystic ilmenite entrainment in the source magma responsible for the non-Diamondiferous nature of the Maddur-Kotakonda-Narayanpet kimberlitesGeological Society of India, Bangalore November Meeting Group Discussion on Kimberlites and Related Rocks India, Abstract p. 72.India, Andhra Pradesh, Dharwar CratonIlmenite, chemistry
DS200812-0025
2008
Dongre, A.Amand, M., Terada, K., Osborne, I., Chalapathi Rao, N.V., Dongre, A.SHRIMP U- Pb dating of perovskite from southern Indian kimberlites.9IKC.com, 3p. extended abstractIndiaGeochronology
DS200812-0199
2008
Dongre, A.Chalapathi Rao, N.V., Dongre, A., Kamde, G., Srivisastra, R.K., Sridhar, M., Kaminisky, F.V.Petrology, geochemistry and genesis of new Mesoproterozoic high magnesian calcite rich kimberlites of Siddanpalli, eastern Dharwar Craton...products9IKC.com, 3p. extended abstractIndiaSubduction related magmatic sources?
DS200812-0200
2008
Dongre, A.Chalapathi Rao, N.V., Kamde, G.D., Kale, H.S., Dongre, A.Geological setting and petrographic diversity of the lamproite dykes at the northern and north eastern margin of the Cuddapah Basin, southern India.Indian Dykes: editors Srivastava, Sivaji, Chalapathi Rao, pp. 281-290.IndiaLamproite
DS200812-0291
2008
Dongre, A.Dongre, A., Chalapathi Rao, N.V., Kamde, G.Limestone xenolith in Siddanpalli kimberlite, Gadwal granite greenstone terrain, eastern Dhwar Craton: remnant of Proterozoic platformal cover sequence - ageJournal of Geology, Vol. 116, pp. 184-191.IndiaDeposit - Siddanpalli
DS200812-0292
2008
Dongre, A.Dongre, A., Chalapathi Rao, N.V., Kamde, G.Limestone xenolith in Siddanpalli kimberlite, Gadwal granite - greenstone terrain, Eastern Dhawar Craton, southern India: remnant of Proterozoic platformal cover sequence of BJournal of Petrology, Vol. 116, pp. 184-191.IndiaGeochronology - Bhima Kurnool age
DS200912-0104
2009
Dongre, A.Chalapathi Rao, N.V., Dongre, A., Kamde, G., Srivastava, R.K., Sridhar, M., Kaminsky, F.V.Petrology, geochemistry and genesis of newly discovered Mesoproterozoic highly magnesian, calcite rich kimberlites from Siddanpalli, Eastern Dharwar CratonMineralogy and Petrology, Online availableIndiaProducts of subduction-related magmatic sources?
DS201012-0097
2010
Dongre, A.Chalapathi Rao, N.V., Anand, M., Dongre, A., Osborne, I.Carbonate xenoliths hosted by the Mesoproterozoic Siddanpalli kimberlite cluster ( Eastern Dharwar craton): implications for the geodynamic evolution ofInternational Journal of Earth Sciences, Vol. 99, pp. 1791-1804.IndiaDiamond and uranium metallogenesis
DS201012-0098
2010
Dongre, A.Chalapathi Rao, N.V., Dongre, A., Kamde, G., Srivastava, R.K., Sridhar, M., Kaminisky, F.V.Petrology, geochemistry and genesis of newly discovered Mesoproterozoic highly magnesian, calcite rich kimberlites from Siddanpalli, eastern Dharwar Craton...Mineralogy and Petrology, Vol. 98, 1-4, pp. 313-328.IndiaSubduction related magmatic sources?
DS201509-0389
2015
Dongre, A.Chalapathi Rao, N.V., Dongre, A., Wu, F-Y., Lehmann, B.A Late Cretaceous ( ca.90Ma) kimberlite event in southern India: implication for sub-continental lithospheric mantle evolution and diamond exploration. WajrakarurGondwana Research, in press available 12p.IndiaDeposit - Timmasamudram
DS201607-1344
2016
Dongre, A.Dongre, A.Classificication of diamond source rocks in the Wajrakarur kimberlite field of southern India: a mineral genetic approach.IGC 35th., Session A Dynamic Earth 1p. AbstractIndiaDeposit - Wajrakur
DS201609-1710
2016
Dongre, A.Chalapathi Rao, N.V., Dongre, A., Wu, F-Y., Lehmann, B.A Late Cretaceous ( ca.90Ma) kimberlite event in southern India: implication for sub-continental lithospheric mantle evolution and diamond exploration.Gondwana Research, Vol. 35, pp. 378-389.India, MadagascarDeposit - Wajrakarur

Abstract: We report groundmass perovskite U -Pb (SIMS) ages, perovskite Nd isotopic (LA-ICPMS) composition and bulk-rock geochemical data of the Timmasamudram diamondiferous kimberlite cluster, Wajrakarur kimberlite field, in the Eastern Dharwar craton of southern India. The kimberlite pipes gave similar Mesoproterozoic ages of 1086 ± 19 Ma (TK-1, microcrystic variant) and 1119 ± 12 Ma (TK-3). However, a perovskite population sampled from the macrocrystic variant of TK-1 gave a much younger Late Cretaceous age of ca. 90 Ma. This macrocrystic kimberlite phase intrudes the Mesoproterozoic microcrystic phase and has a distinct bulk-rock geochemistry. The Nd-isotope composition of the ~ 1100 Ma perovskites in the cluster show depleted eNd(T) values of 2.1 ± 0.6 to 6.7 ± 0.3 whereas the ~ 90 Ma perovskites have enriched eNd(T) values of - 6.3 ± 1.3. The depleted-mantle (DM) model age of the Cretaceous perovskites is 1.2 Ga, whereas the DM model age of the Proterozoic perovskites is 1.2 to 1.5 Ga. Bulk-rock incompatible trace element ratios (La/Sm, Gd/Lu, La/Nb and Th/Nb) of all Timmasamudram kimberlites show strong affinity with those from the Cretaceous Group II kimberlites from the Bastar craton (India) and Kaapvaal craton (southern Africa). As the Late Cretaceous age of the younger perovskites from the TK-1 kimberlite is indistinguishable from that of the Marion hotspot-linked extrusive and intrusive igneous rocks from Madagascar and India, we infer that all may be part of a single Madagascar Large Igneous Province. Our finding constitutes the first report of Cretaceous kimberlite activity from southern India and has significant implications for its sub-continental lithospheric mantle evolution and diamond exploration programs.
DS201612-2295
2016
Dongre, A.Dongre, A., Chalapathi Rao, N.V., Viljoen, K.S., Lehmann, B.Petrology, genesis and geodynamic implication of the Mesoproterozoic- Late Cretaceous Timmasamudram kimberlite cluster, Wajrakarur field, eastern Dharwar craton, southern India.Geoscience Frontiers, in press availableIndiaDeposit - Timmasamudram

Abstract: New mineralogical and bulk-rock geochemical data for the recently recognised Mesoproterozoic (ca. 1100 Ma) and late Cretaceous (ca. 90 Ma) kimberlites in the Timmasamudram cluster (TKC) of the Wajrakarur kimberlite field (WKF), Eastern Dharwar Craton, southern India, are presented. On the basis of groundmass mineral chemistry (phlogopite, spinel, perovskite and clinopyroxene), bulk-rock chemistry (SiO2, K2O, low TiO2, Ba/Nb and La/Sm), and perovskite Nd isotopic compositions, the TK-1 (macrocrystic variety) and TK-4 (microcrystic variety) kimberlites in this cluster are here classified as orangeites (i.e. Group II kimberlites), with geochemical characteristics that are very similar to orangeites previously described from the Bastar Craton in central India, as well as the Kaapvaal Craton in South Africa. The remaining kimberlites (e.g., TK-2, TK-3 and the TK-1 microcrystic variant), are more similar to other 1100 Ma, Group I-type kimberlites of the Eastern Dharwar Craton, as well as the typical Group I kimberlites of the Kaapvaal Craton. Through the application of geochemical modelling, based on published carbonated peridotite/melt trace element partition coefficients, we show that the generation of the TKC kimberlites and the orangeites results from low degrees of partial melting of a metasomatised, carbonated peridotite.
DS201707-1319
2017
Dongre, A.Dongre, A., Chalapathi Rao, N.V., Viljpoen, K.S., Lehmann, B.Petrology, genesis and geodynamic implication of the Mesoproterozoic - Late Cretaceous Timmasamudram kimberlite cluster, Wajrakarur field, eastern Dharwar Craton, southern India.Geoscience Frontiers, Vol. 8, pp. 541-553.Indiadeposit - Timmasamudram

Abstract: New mineralogical and bulk-rock geochemical data for the recently recognised Mesoproterozoic (ca. 1100 Ma) and late Cretaceous (ca. 90 Ma) kimberlites in the Timmasamudram cluster (TKC) of the Wajrakarur kimberlite field (WKF), Eastern Dharwar Craton, southern India, are presented. On the basis of groundmass mineral chemistry (phlogopite, spinel, perovskite and clinopyroxene), bulk-rock chemistry (SiO2, K2O, low TiO2, Ba/Nb and La/Sm), and perovskite Nd isotopic compositions, the TK-1 (macrocrystic variety) and TK-4 (Macrocrystic variety) kimberlites in this cluster are here classified as orangeites (i.e. Group II kimberlites), with geochemical characteristics that are very similar to orangeites previously described from the Bastar Craton in central India, as well as the Kaapvaal Craton in South Africa. The remaining kimberlites (e.g., TK-2, TK-3 and the TK-1 microcrystic variant), are more similar to other 1100 Ma, Group I-type kimberlites of the Eastern Dharwar Craton, as well as the typical Group I kimberlites of the Kaapvaal Craton. Through the application of geochemical modelling, based on published carbonated peridotite/melt trace element partition coefficients, we show that the generation of the TKC kimberlites and the orangeites results from low degrees of partial melting of a metasomatised, carbonated peridotite. Depleted mantle (TDM) Nd perovskite model ages of the 1100 Ma Timmasamudram kimberlites show that the metasomatic enrichment of their source regions are broadly similar to that of the Mesoproterozoic kimberlites of the EDC. The younger, late Cretaceous (ca. 90 Ma) TK-1 (macrocrystic variant) and TK-4 kimberlites, as well as the orangeites from the Bastar Craton, share similar Nd model ages of 1100 Ma, consistent with a similarity in the timing of source enrichment during the amalgamation of Rodinia supercontinent. The presence of late Cretaceous diamondiferous orangeite activity, presumably related to the location of the Marion hotspot in southern India at the time, suggests that thick lithosphere was preserved, at least locally, up to the late Cretaceous, and was not entirely destroyed during the breakup of Gondwana, as inferred by some recent geophysical models.
DS201708-1628
2017
Dongre, A.Dongre, A.Ultramafic lamprophyre from the Wajrakarur kimberlite field of southern India and its petrogenetic significance.11th. International Kimberlite Conference, PosterIndiadeposit - Wajrakarur
DS201809-2099
2018
Dongre, A.Tappe, S., Dongre, A., Liu, C-Z., Wu, F-Y.Premier evidence for prolonged kimberlite pipe formation and its influence on diamond transport from deep Earth. Dikes sampled, geochronologyGeology, Vol. 46, pp. 843-846.Africa, South Africadeposit - Cullinan

Abstract: Volcanic pipes, or maar-diatreme volcanoes, form during explosive eruptions of mantle-derived magmas near Earth's surface. Impressive examples are the carrot-shaped, downward tapering structures formed by kimberlite magmas. Kimberlites originate from >150 km depth within Earth's mantle beneath thick continental roots, away from tectonic plate margins. Kimberlite pipes can be significant diamond deposits, and the complex architecture revealed during exploration and mining is ascribed to repeated magma injections leading to multiple eruptions. Repeated magmatic pulses cause diatremes to widen and grow downward, forming kilometer-sized subterranean structures. However, the time-resolved evolution of kimberlite pipe systems is largely unknown. We present the first U/Pb perovskite ages for newly discovered kimberlite dikes (1139.8 ± 4.8 Ma) that cut through the volcaniclastic infill of the Premier kimberlite pipe (1153.3 ± 5.3 Ma) at Cullinan Diamond Mine, South Africa. The ages reveal that renewed kimberlite volcanic activity occurred, at a minimum, 3 m.y. after the main pipe formation. This finding suggests that the largest kimberlite pipes, and maar-diatreme volcanoes in general, may be magmatically active for several millions of years, which conflicts with this volcanism being described as 'monogenetic' at millennia time scales. Exemplified by Tier-1 diamond deposits on the Kaapvaal craton, long-lasting kimberlite volcanic activity may be an important factor in growing large diatremes, plus enabling effective transport of mantle cargo from the diamond stability field to Earth's surface.
DS201905-1041
2019
Dongre, A.Hazarika, B., Malpe, D.B., Dongre, A.Petrology and geochemistry of a boninite dyke from the western Bastar craton of central India.Journal of Earth System Science, Vol. 128:32Indiacraton

Abstract: The Dongargarh Supergroup along with the basal Amgaon Gneissic Complex constitutes the northwestern part of the central Indian Bastar craton. In the present study, we report a new finding of a boninite dyke intruded in the Amgaon gneisses of this area. The dyke composed of mainly pyroxenes, amphiboles and subordinate amount of plagioclase. The higher contents of SiO2 (51-54 wt.%), MgO (12-14 wt.%), Ni (375-473 ppm), Cr (1416-1580 ppm) and very low TiO2 (0.2-0.4 wt.%) are consistent with the boninite nature of the dyke as well as the unevolved primary nature of the source magma. The extraordinarily high CaO content (15.97-17.7 wt.%) with higher CaO/Al2O3 (3.13-3.96) ratios classifies it as high-Ca boninite. The trace element ratios including Zr/Ti, Ti/V, Ti/Sc and Ti/Yb further show its geochemical similarity with the Archaean boninite. The dyke also shows negative high-field strength element (Nb, Ta and Ti) anomalies which are the characteristics of the boninite rocks reported elsewhere and along with the enriched light rare earth element pattern, it shows more affinity particularly with the northern Bastar boninite dyke. The mineralogical and geochemical similarities of the boninite dykes from the Bastar craton indicate a widespread boninitic event during the Palaeoproterozoic having a similar origin. These boninite dykes indicate the preservation of subduction-related signatures in the lithospheric mantle beneath the Bastar craton at the time of its evolution or may be during the convergence of the Bastar and Bundelkhand cratons.
DS201906-1288
2019
Dongre, A.Dongre, A., Tappe, S.Kimberlite and carbonatite dykes within the Premier diatreme root ( Cullinan diamond mine, South Africa: new insights to mineralogical-genetic classifications and magma CO2 degassing.Lithos, Vol. 338-339, pp. 155-173.Africa, South Africadeposit - Cullinan

Abstract: The ca. 1153?Ma Premier kimberlite pipe on the Kaapvaal craton has been intruded by late-stage kimberlite and carbonatite magmas forming discrete 0.5 to 5?m wide dykes within the lower diatreme. On the basis of petrography and geochemistry, the fresh kimberlite dykes represent archetypal monticellite phlogopite kimberlite of Group-1 affinity. Their mineral compositions, however, show marked deviations from trends that are typically considered as diagnostic for Group-1 kimberlite in mineralogical-genetic classification schemes for volatile-rich ultramafic rocks. Groundmass spinel compositions are transitional between magnesian ulvöspinel (a Group-1 kimberlite hallmark feature) and titanomagnetite trends, the latter being more diagnostic for lamproite, orangeite (formerly Group-2 kimberlite), and aillikite. The Premier kimberlite dykes contain groundmass phlogopite that evolves by Al- and Ba-depletion to tetraferriphlogopite, a compositional trend that is more typical for orangeite and aillikite. Although high-pressure cognate and groundmass ilmenites from the Premier hypabyssal kimberlites are characteristically Mg-rich (up to 15?wt% MgO), they contain up to 5?wt% MnO, which is more typical for carbonate-rich magmatic systems such as aillikite and carbonatite. Manganese-rich groundmass ilmenite also occurs in the Premier carbonatite dykes, which are largely devoid of mantle-derived crystal cargo, suggesting a link to the kimberlite dykes by fractionation processes involving development of residual carbonate-rich melts and fluids. Although mineralogical-genetic classification schemes for kimberlites and related rocks may provide an elegant approach to circumvent common issues such as mantle debris entrainment, many of the key mineral compositional trends are not as robust for magma type identification as previously thought. Utilizing an experimentally constrained CO2-degassing model, it is suggested that the Premier kimberlite dykes have lost between 10 and 20?wt% CO2 during magma ascent through the cratonic lithosphere, prior to emplacement near the Earth's surface. Comparatively low fO2 values down to -5.6 ?NNO are obtained for the kimberlite dykes when applying monticellite and perovskite oxybarometry, which probably reflects significant CO2 degassing during magma ascent rather than the original magma redox conditions and those of the deep upper mantle source. Thus, groundmass mineral oxybarometry may have little value for the prediction of the diamond preservation potential of ascending kimberlite magmas. After correction for olivine fractionation and CO2-loss, there remains a wide gap between the primitive kimberlite and carbonatite melt compositions at Premier, which suggests that these magma types cannot be linked by variably low degrees of partial melting of the same carbonated peridotite source in the deep upper mantle. Instead, fractionation processes produced carbonate-rich residual melts/fluids from ascending kimberlite magma, which led to the carbonatite dykes within Premier pipe.
DS201910-2272
2019
Dongre, A.Khan, S., Dongre, A., Viljoen, F., Li, Q., Le Roux, P.Petrogenesis of lamprophyres synchronous to kimberlites from the Wajrakarur kimberlite field: implications for contrasting lithospheric mantle sources and geodynamic evolution of the eastern Dharwar craton of southern India.Geological Journal, Vol. 54, 5, pp. 2994-3016.Indiadeposit - Wajrakarur

Abstract: Kimberlite field is an example of widespread Mesoproterozoic intracontinental magmatism. Recent studies have identified deep subcontinental lithospheric mantle as a source region of the kimberlite magmatism while timing, origin, and processes responsible for the generation of coeval lamprophyres remain poorly constrained. Here, we present and discuss new petrological and geochemical data for two lamprophyre dykes from the Wajrakarur kimberlite field and assess their petrogenetic relation to the kimberlite occurrences. Based on mineral compositional and whole-rock geochemical characters, it is suggested that lamprophyres are formed through low degrees of partial melting of “enriched” lithospheric mantle that was modified and metasomatized by melts derived from recycled crust. This differs from geochemical imprints found in coeval kimberlites, where a crustal source component appears to be absent and is more consistent with rock derivation from “depleted” lithosphere which has experienced interaction with asthenosphere-derived melts. An apparent lack of garnet in the mantle sources of lamprophyres is suggestive of melting at comparatively shallow depth (~100 km) relative to the kimberlites. Hence, these geochemically contrasting rocks, although have formed at the same time, are derived from vertically heterogeneous lithospheric mantle sources and can be explained through and linked with a thermal anomaly in the underlying convective asthenosphere. We suggest that the deeper mantle source region of the kimberlites was more pristine and devoid of subduction-related signatures, whereas the shallower mantle source region of the lamprophyres seems to have preserved imprints of plate convergence and subduction associated with the evolution of the Dharwar Craton.
DS202002-0192
2019
Dongre, A.Hazarika, B., Malpe, D.B., Dongre, A.Petrology and geochemistry of a boninite dyke from the western Bastar craton of central India.Journal of Earth System Science, Vol. 128, 17p. PdfIndiaboninite

Abstract: The Dongargarh Supergroup along with the basal Amgaon Gneissic Complex constitutes the northwestern part of the central Indian Bastar craton. In the present study, we report a new finding of a boninite dyke intruded in the Amgaon gneisses of this area. The dyke composed of mainly pyroxenes, amphiboles and subordinate amount of plagioclase. The higher contents of SiO2 (51-54 wt.%), MgO (12-14 wt.%), Ni (375-473 ppm), Cr (1416-1580 ppm) and very low TiO2 (0.2-0.4 wt.%) are consistent with the boninite nature of the dyke as well as the unevolved primary nature of the source magma. The extraordinarily high CaO content (15.97-17.7 wt.%) with higher CaO/Al2O3 (3.13-3.96) ratios classifies it as high-Ca boninite. The trace element ratios including Zr/Ti, Ti/V, Ti/Sc and Ti/Yb further show its geochemical similarity with the Archaean boninite. The dyke also shows negative high-field strength element (Nb, Ta and Ti) anomalies which are the characteristics of the boninite rocks reported elsewhere and along with the enriched light rare earth element pattern, it shows more affinity particularly with the northern Bastar boninite dyke. The mineralogical and geochemical similarities of the boninite dykes from the Bastar craton indicate a widespread boninitic event during the Palaeoproterozoic having a similar origin. These boninite dykes indicate the preservation of subduction-related signatures in the lithospheric mantle beneath the Bastar craton at the time of its evolution or may be during the convergence of the Bastar and Bundelkhand cratons.
DS202003-0342
2020
Dongre, A.Hazarika, B., Malpe, D.B., Dongre, A.Petrogenesis of mafic dykes from the western Bastar craton of central India and their relation to ourgrowth of Columbia supercontinent.Mineralogy and Petrology, in press available, 20p. PdfIndiacraton

Abstract: We report mineral compositions and bulk rock geochemistry of mafic dykes intruded in the western part of Bastar craton, comprising of Archaean Amgaon Group and Proterozoic Dongargarh Supergroup of rocks. Field relations show two distinct trends of these dykes which are almost perpendicular to each other but having similar mineralogical and geochemical characteristics. Dykes are mostly composed of pyroxenes, plagioclase and subordinate amount of amphiboles and Fe-Ti oxides (magnetite and ilmenite). These hypersthene normative basaltic dykes show tholeiitic trend and are characterised by narrow compositional variations of MgO (6.067.08 wt%), FeOt (15.0617.78 wt%), TiO2 (1.182.24 wt%), Al2O3 (11.9615.54 wt%) and low Mg# [atomic Mg/(Mg?+?Fe2+)?×?100] values in the range of 3748. Low loss on ignition (LOI) values <2 wt% and significant trends of trace elements (Nb, La, Th, Sr) with Zr indicate insignificant effects of post magmatic processes in these dykes. Smooth correlations between major oxides and MgO, among trace element ratios (Ce/La, Th/Yb, Nb/Yb) and negative Nb-Ta anomalies without positive Zr and Hf anomalies negate the crustal contamination effects. The correlations of compatible (e.g. Cr, Ni) and incompatible (e.g. Ba, Rb) elements show involvement of both fractional crystallisation and partial melting processes in their formation. Flat heavy rare earth element (HREE) pattern with low (Tb/Yb)n values reveal their genesis from a mantle source without involvement of garnet and geochemical models suggested in the present study indicate melting from spinel lherzolite mantle source. Strong geochemical similarities of present dykes with those of earlier reported Lakhna (1.46 Ga) and Bandimal (1.42 Ga) dykes of northern Bastar craton suggest a widespread mafic magmatic event across the Bastar craton during 1.421.46 Ga. Present dykes therefore represent a subduction related outgrowth of Columbia supercontinent due to the accretion of continental margins.
DS202009-1651
2020
Dongre, A.Pattnaik, J., Ghosh, S., Dongre, A.Plume activity and carbonated silicate melt metasomatism in Dharwar cratonic lithosphere: evidence from peridotite xenoliths in Wajrakarur kimberlites.Lithos, in press available, 63p. PdfIndiadeposit - Wajrakarur

Abstract: We report petrography, mineralogy, major- and trace-element compositions of a rare selection of spinel- and garnet-bearing peridotite xenoliths and single crystals separated from peridotites hosted in the Mesoproterozoic Wajrakarur kimberlites from the Eastern Dharwar craton (EDC), India. These ultramafic xenoliths consist of olivine (modal 74-82 vol%) with Fo92-93, clinopyroxene, orthopyroxene, spinel, garnet, and/or ilmenite. Calculated equilibrium pressure and temperature conditions are 2.5-5.0?GPa and 710-1179?°C for these peridotites, which suggests residence depths >160?km near the base of the Dharwar cratonic lithospheric mantle. Garnet in these ultramafic rocks [with Mg#?=?molar (Mg/(Mg?+?Fetotal)?×?100 of 80-88] displays either “sinuous” LREE-enriched patterns with depletion in Gd and Er for harzburgites or “normal” LREE-depleted, HREE-enriched patterns for lherzolites. Two groups of clinopyroxenes (group-I and group-II) were also observed with high LREE (LaN?>?10) and low LREE (LaN?
DS201012-0099
2009
Dongre, A.N.Chalapathi Rao, N.V., Dongre, A.N.Mineralogy and geochemistry of kimberlites NK-2 and KK-6 Narayanpet kimberlite field, eastern Dharwar Craton, southern India: evidence for transitional ...The Canadian Mineralogist, Vol. 47, 5, pp. 1117-1135,IndiaKimberlite signature
DS201012-0162
2010
Dongre, A.N.Dongre, A.N., Chalapathi Rao, N.V.Mineralogy and geochemistry of NK-2 and KK-6 kimberlites, Narayanpet kimberlite field, eastern Dharwar craton, southern India: evidence....International Dyke Conference Held Feb. 6, India, 1p. AbstractIndiaEvidence for transitional (South African)K signature
DS201412-0116
2014
Dongre, A.N.Chalapathi Rao, N.V., Kumar, A., Sahoo, S., Dongre, A.N., Talukdar, D.Petrology and petrogenesis of Mesoproterozoic lamproites from the Ramadugu field NW margin of the Cuddapah basin, eastern Dharwar craton, southern India.Lithos, Vol. 196-197, pp. 150-168.IndiaLamproite
DS201412-0187
2013
Dongre, A.N.Dhote, P.S., Dongre, A.N., Subbarao, D.V.Petrochemistry of crater facies Tokapal kimberlite pipe, Bastar craton, central India and its orangeitic affinities.Journal of the Geological Society of India, Vol. 82, no. 5, pp. 484-494.IndiaOrangeite
DS201508-0350
2015
Dongre, A.N.Dongre, A.N., Jacob, D.E., Stern, R.A.Subduction related origin of eclogite xenoliths from the Wajrakarur kimberlite field, Eastern Dharwar craton, southern India: constraints from petrology and geochemistry.Geochimica et Cosmochimica Acta, Vol. 166, pp. 165-188.IndiaDeposit - Wajrakarur
DS201508-0351
2015
Dongre, A.N.Dongre, A.N., Viljoen, K.S., Ma, M.The Pipe-15 kimberlite: a new addition to the Wajrakarur cluster of the Wajrakarur kimberlite field, Eastern Dharwar craton, southern India.Journal of the Geological Society of India, Vol. 86, 1, pp. 71-79.IndiaDeposit - Pipe-15
DS201603-0373
2016
Dongre, A.N.Dongre, A.N., Viljoen, K.S., Chalapathi Rao, N.V., Gucsik, A.Origin of Ti rich garnets in the groundmass of Wajrakarur field kimberlites, southern India: insights from EPMA and Raman spectroscopy.Mineralogy and Petrology, in press available, 13p.IndiaDeposit - Wajrakur

Abstract: Although Ti-rich garnets are commonly encountered in the groundmass of many alkaline igneous rocks, they are comparatively rare in kimberlites. Here we report on the occurrence of Ti-rich garnets in the groundmass of the P-15 and KL-3 kimberlites from the diamondiferous Wajrakarur field in the Eastern Dharwar craton of southern India. These garnets contain considerable Ti (11.7-23.9 wt.% TiO2), Ca (31.3-35.8 wt.% CaO), Fe (6.8-15.5 wt.% FeOT) and Cr (0.04-9.7 wt.% Cr2O3), but have low Al (0.2-5.7 wt.% Al2O3). In the case of the P-15 kimberlite they display a range in compositions from andradite to schorlomite, with a low proportion of grossular (andradite(17.7-49.9)schorlomite(34.6-49.5)-grossular(3.7-22.8)-pyrope(1.9-10.4)). A few grains also contain significant chromium and represent a solid solution between schorlomite and uvarovite. The Ti-rich garnets in the KL-3 kimberlite, in contrast, are mostly schorlomitic (54.9-90.9 mol %) in composition. The Ti-rich garnets in the groundmass of these two kimberlites are intimately associated with chromian spinels, perhaps suggesting that the garnet formed through the replacement of spinel. From the textural evidence, it appears unlikely that the garnets could have originated through secondary alteration, but rather seem to have formed through a process in which early magmatic spinels have reacted with late circulating, residual fluids in the final stages of crystallization of the kimberlite magma. Raman spectroscopy provides evidence for low crystallinity in the spinels which is likely to be a result of their partial transformation into andradite during their reaction with a late-stage magmatic (kimberlitic) fluid. The close chemical association of these Ti-rich garnets in TiO2-FeO-CaO space with those reported from ultramafic lamprophyres (UML) is also consistent with results predicted by experimental studies, and possibly implies a genetic link between kimberlite and UML magmas. The occurrence of Ti-rich garnets of similar composition in the Swartruggens orangeite on the Kaapvaal craton in South Africa, as well as in other kimberlites with an orangeitic affinity (e.g. the P-15 kimberlite on the Eastern Dharwar craton in southern India), is inferred to be a reflection of the high Ca- and high Ti-, and the low Al-nature, of the parent magma (i.e. Group II kimberlites).
DS201605-0828
2016
Dongre, A.N.Dongre, A.N., Viljoen, K.S., Chalapathi Rao, N.V.Origins of Ti-rich garnets in the groundmass of Wajrakarur field kimberlites, southern India: insights from EPMA and Raman spectroscopy.Mineralogy and Petrology, Vol. 110, 2, pp. 295-307.IndiaDeposit - Wajrakarur

Abstract: Although Ti-rich garnets are commonly encountered in the groundmass of many alkaline igneous rocks, they are comparatively rare in kimberlites. Here we report on the occurrence of Ti-rich garnets in the groundmass of the P-15 and KL-3 kimberlites from the diamondiferous Wajrakarur field in the Eastern Dharwar craton of southern India. These garnets contain considerable Ti (11.7-23.9 wt.% TiO2), Ca (31.3-35.8 wt.% CaO), Fe (6.8-15.5 wt.% FeOT) and Cr (0.04-9.7 wt.% Cr2O3), but have low Al (0.2-5.7 wt.% Al2O3). In the case of the P-15 kimberlite they display a range in compositions from andradite to schorlomite, with a low proportion of grossular (andradite(17.7-49.9)schorlomite(34.6-49.5)-grossular(3.7-22.8)-pyrope(1.9-10.4)). A few grains also contain significant chromium and represent a solid solution between schorlomite and uvarovite. The Ti-rich garnets in the KL-3 kimberlite, in contrast, are mostly schorlomitic (54.9-90.9 mol %) in composition. The Ti-rich garnets in the groundmass of these two kimberlites are intimately associated with chromian spinels, perhaps suggesting that the garnet formed through the replacement of spinel. From the textural evidence, it appears unlikely that the garnets could have originated through secondary alteration, but rather seem to have formed through a process in which early magmatic spinels have reacted with late circulating, residual fluids in the final stages of crystallization of the kimberlite magma. Raman spectroscopy provides evidence for low crystallinity in the spinels which is likely to be a result of their partial transformation into andradite during their reaction with a late-stage magmatic (kimberlitic) fluid. The close chemical association of these Ti-rich garnets in TiO2-FeO-CaO space with those reported from ultramafic lamprophyres (UML) is also consistent with results predicted by experimental studies, and possibly implies a genetic link between kimberlite and UML magmas. The occurrence of Ti-rich garnets of similar composition in the Swartruggens orangeite on the Kaapvaal craton in South Africa, as well as in other kimberlites with an orangeitic affinity (e.g. the P-15 kimberlite on the Eastern Dharwar craton in southern India), is inferred to be a reflection of the high Ca- and high Ti-, and the low Al-nature, of the parent magma (i.e. Group II kimberlites).
DS1975-0998
1979
Donkers, J.M.Donkers, J.M.Equipment for Off-shore MiningResources Minerales Sous Marines, Scolari, G. Editor., French Geological Survey (BRGM) No. 7, PP. 275-295.South Africa, West AfricaDiamond Mining Recovery, Alluvials, Marine Placers
DS200512-0243
2004
Donnadieu, Y.Donnadieu, Y., Ramstein, G., Godderis, Y., Fluteau, F.Global tectonic setting and climate of the Late Neoproterozoic: a climate geochemical coupled study.American Geophysical Union, Geophysical Monograph, No. 146, pp. 79-90.Geomorphology - tectonics
DS200812-0638
2008
Donnadieu, Y.Le Hir, G., Ramstein, G., Donnadieu, Y., Godderis, Y.Scenario for the evolution of atmospheric pCO2 during a snowball Earth.Geology, Vol. 36, 1, pp. 47-50.MantleCarbon cycle
DS201201-0845
2011
Donnadieu, Y.Godderis, Y., Le Hir, G., Donnadieu, Y.Modelling the Snowball Earth.The Geological Record of Neoproterozoic glaciations, Memoirs 2011; Vol. 36, pp. 151-161.GlobalSnowball - model
DS202001-0034
2019
Donnadieu, Y.Ramstein, G., Godderis, Y., Donnadieu, Y., Sepulchre, P., Fluteau, F., Zhang, Z., Zhang, R., Su, B., Jiang, D., Schuster, M., Besse, J.Some illustrations of large tectonically driven climate changes in Earth history.Tectonics, doi.org/10.1029/ 2019TC005569Mantletectonics

Abstract: For the celebration of the 50th anniversary of the publication of the pioneering papers that established the basis of plate tectonic, this paper was solicited to illustrate the close relation between tectonics and climate. Amongst the large spectrum of interactions that depict how tectonics modified the climate at geological time steps, we choose to illustrate two major issues: (1) How the “tryptic” climate/long-term carbon cycle/tectonics explains the extraordinary glacial episode (717-635 Ma) occurring during Neoproterozoic era? (2) How major tectonic events (i.e., the slow shrinkage of a huge epicontinental sea and the uplift of large mountains ranges in Asia and Africa) drastically changed the climate and shaped the pattern of present-day monsoons systems. This paper is the result of long-standing collaboration with many researchers from different countries.
DS1981-0142
1981
Donnay, G.Donnay, G.The Symmetry of DiamondInternational CONGRESS of CRYSTALLOGRAPHY, No. 12, P. C-187.GlobalDiamond Morphology
DS1981-0143
1981
Donnay, G.Donnay, G., Donnay, J.D.H.Symmetry and Twinning in DiamondSoviet Physics, Crystallography, Vol. 26, No. 6, PP. 729-732.RussiaKimberlite
DS1981-0143
1981
Donnay, J.D.H.Donnay, G., Donnay, J.D.H.Symmetry and Twinning in DiamondSoviet Physics, Crystallography, Vol. 26, No. 6, PP. 729-732.RussiaKimberlite
DS1985-0331
1985
Donnell, G.P.Kaygi, P.B.O, Donnell, G.P., Welland, M.J.Stratigraphy and Tectonic Development of the Southern Ouachita Thrust Belt- Implications of New Subsurface Data, Arkansas.Geological Society of America (GSA), Vol. 17, No. 7, P. 624. (abstract.).United States, Gulf Coast, Arkansas, OklahomaTectonics
DS200712-0209
2006
Donnelly, C.Creighton, S., Stachel, T., McLean, H., Donnelly, C., Whiteford, S., Luth, R.W.Diamondiferous peridotite microxenoliths from the Diavik diamond mine: a challenge to the G10 paradigm in diamond exploration?34th Yellowknife Geoscience Forum, p. 13. abstractCanada, Northwest TerritoriesGeology - Diavik
DS200612-1361
2006
Donnelly, C.L.Stachel, T., Creighton, S., McLean, H., Donnelly, C.L., Whiteford, S., Luth, R.W.Diamondiferous microxenoliths from the Diavik diamond mine ( Canada): lherzolite hosts for harzburgitic diamonds?Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 56. abstract only.Canada, Northwest TerritoriesDeposit - Diavik, xenolith mineral chemistry
DS200712-0265
2007
Donnelly, C.L.Donnelly, C.L., Stachel, T., Creighton, S., Muehlenbachs, K., Whiteford, S.Diamonds and their mineral inclusions from A154 South pipe mine, Northwest Territories, Canada.Lithos, Vol. 98, 1-4, pp. 160-176.Canada, Northwest TerritoriesDeposit - A154
DS200812-0293
2008
Donnelly, C.L.Donnelly, C.L., O'Reilly, S.Y., Griffin, W.L.The kimberlites and related rocks of the Kuruman kimberlite Province, Kaapvaal Craton, South Africa.9IKC.com, 3p. extended abstractAfrica, South AfricaDeposit - Kuruman - petrography
DS201012-0163
2010
Donnelly, C.L.Donnelly, C.L., Griffin, W.L., O'Reilly, S.Y.,Pearson, N.J., Shee, S.R.The kimberlites and related rocks of the Kuruman kimberlite Province, Kaapvaal Craton, South Africa.Contributions to Mineralogy and Petrology, in press available 21p.Africa, South AfricaGeochemistry - trace elements
DS201112-0282
2006
Donnelly, C.L.Donnelly, C.L.The characterization of diamonds and their mineral inclusions from the Diavik diamond mine, Lac de Gras, Northwest Territories, Canada.Thesis: University of Alberta, Earth and Atmospheric Sciences Msc., 187p.Canada, Northwest TerritoriesThesis - note availability based on request to author
DS201112-0283
2011
Donnelly, C.L.Donnelly, C.L., Griffin, W.L., O'Reilly, S.Y.,Pearson, N.J., Shee, S.R.The kimberlites and related rocks of the Kuruman kimberlite province, Kaapvaal craton, South Africa.Contributions to Mineralogy and Petrology, Vol. 161, 3, pp. 351-371.Africa, South AfricaDeposit -
DS201212-0011
2012
Donnelly, C.L.Aliforova, T.A., Pokhilenko, L.N., Ovchinnikov, Y.I., Donnelly, C.L., Riches, A.J.V., Taylor, L.A.Petrologic origin of exsolution textures in mantle minerals: evidence in pyroxenite xenoliths from Yakutia kimberlites.International Geology Review, Vol. 54, 9, pp. 1071-1092.RussiaDeposit - Yakutia
DS201212-0167
2012
Donnelly, C.L.Donnelly, C.L., Griffin, W.L., Yang, J-H., O'Reilly, Z.Y., li Li, Q., Pearson, N.J., Li, X-H.In situ U Pb dating and Sr Nd isotopic analysis of perovskite: constraints on the age and petrogenesis of the Kuruman kimberlite province, Kaapvaal Craton, South Africa.Journal of Petrology, Vol. 53, 12, pp. 2407-2522.Africa, South AfricaDeposit - Kuruman
DS200412-0469
2004
Donnelly, K.E.Donnelly,K.E., Goldstein, S.L., Langmuir, C.H., Spiegelman, M.Origin of enriched ocean ridge basalts and implications for mantle dynamics.Earth and Planetary Science Letters, Vol. 226, 3-4, Oct. 15, pp. 347-366.MantleE-MORB, geochemistry, isotope, trace, convective mixing
DS200612-0344
2005
Donnelly, L.Donnelly, L., et al.The characterization of diamonds and their mineral inclusions from the Diavik Diamond Mine, Lac de Gras NWT Canada.32ndYellowknife Geoscience Forum, POSTERCanada, Northwest TerritoriesDiamond inclusions
DS200812-0294
2008
Donnelly, L.J.Donnelly, L.J.Communication in geology: a personal perspective and lessons from volcanic, mining, exploration, geotechnical, police and geoforensic investigations.Geological Society of London Special Publication, No. 305, pp. 107-121.Media
DS1975-0499
1977
Donnelly, M.E.Donnelly, M.E., Mccallum, M.E.Petrology and Structure of the Southern Portion of the Mullen Creek Mafic Complex, Medicine Bow Mountains, Wyoming.Geological Society of America (GSA), Vol. 9, No. 6, PP. 72-721, (abstract.).United States, Wyoming, Rocky Mountains, Medicine Bow MountainsBlank
DS1975-0999
1979
Donnelly, M.E.Donnelly, M.E.Petrology and Structure of a Portion of the Precambrian Mullen Creek Metaigneus Mafic Complex, Medicine Bow Mountains, Wyoming.Fort Collins: Msc. Thesis, Colorado State University, United States, Wyoming, Rocky Mountains, Medicine Bow MountainsRegional Studies
DS1982-0419
1982
Donnelly, M.E.Mccallum, M.E., Donnelly, M.E., Mussard, D.E.Generalized Geologic Map and Rapid Whole Rock, Minor ElementUnited States Geological Survey (USGS) OPEN FILE REPORT., IN PREP.GlobalKimberlite, Medicine Bow Mountains Rocky Mountains
DS2001-1149
2001
Donnelly-Nolan, J.Tanton, L.T.E., Grove, T.L., Donnelly-Nolan, J.Hot shallow mantle melting under the Cascades volcanic arcGeology, Vol. 19, No. 7, July pp. 631-4.California, OregonSubduction - not related to diamonds
DS1996-0375
1996
Donner, J.Donner, J.The Fennoscandian shield within FennoscandiaBulletin. Geological Society Finland, Vol. 68, 1, pp. 99-103.FinlandBaltic shield, Terminology - Fennoscandia
DS200912-0181
2009
Donnkervoort, L.J.Donnkervoort, L.J., Southam, G.Microbial response in peat overlying kimberlite pipes in the Attawapiskat area, northern Ontario.EOS Transaction of AGU, Vol. 90, no. 22 1p. abstractCanada, Ontario, AttawapiskatGeochemistry
DS2000-0240
2000
Donohue, C.L.Donohue, C.L., Essene, E.J.An oxygen barometer with the assemblage garnet - epidoteEarth and Planetary Science Letters, Vol.181, No.3, Sept.15, pp.459-72.GlobalGeobarometry
DS200412-1417
2004
Donolini, A.Nekvasil, H., Donolini, A., Horn, J., Filiberto, J., Long, H., Lindsley, D.H.The origin and evolution of silica saturated alkalic suites: an experimental study.Journal of Petrology, Vol. 45, 4, pp. 669-691.TechnologyAlkalic
DS1970-0505
1972
Donova, K.V.Donova, K.V., Uvarov, V.A., et al.Sokrovishcha Almaznogo Fonda SssrMoscova: Izdatelstvo Izobrazitelnoe Iskusstvo, 136P.RussiaKimberlite, Kimberley, Catalogue, Diamond
DS201709-1951
2017
Donovan, J.J.Andersen, A.K., Clark, J.G., Larson, P.B., Donovan, J.J.REE fractionation, mineral speciation, and supergene enrichment of the Bear Lodge carbonatites, Wyoming, USA.Ore Geology Reviews, Vol. 89, pp. 780-807.United States, Wyomingcarbonatite - Bear Lodge

Abstract: The Eocene (ca. 55–38 Ma) Bear Lodge alkaline complex in the northern Black Hills region of northeastern Wyoming (USA) is host to stockwork-style carbonatite dikes and veins with high concentrations of rare earth elements (e.g., La: 4140–21000 ppm, Ce: 9220–35800 ppm, Nd: 4800–13900 ppm). The central carbonatite dike swarm is characterized by zones of variable REE content, with peripheral zones enriched in HREE including yttrium. The principle REE-bearing phases in unoxidized carbonatite are ancylite and carbocernaite, with subordinate monazite, fluorapatite, burbankite, and Ca-REE fluorocarbonates. In oxidized carbonatite, REE are hosted primarily by Ca-REE fluorocarbonates (bastnäsite, parisite, synchysite, and mixed varieties), with lesser REE phosphates (rhabdophane and monazite), fluorapatite, and cerianite. REE abundances were substantially upgraded (e.g., La: 54500–66800 ppm, Ce: 11500–92100 ppm, Nd: 4740–31200 ppm) in carbonatite that was altered by oxidizing hydrothermal and supergene processes. Vertical, near surface increases in REE concentrations correlate with replacement of REE(±Sr,Ca,Na,Ba) carbonate minerals by Ca-REE fluorocarbonate minerals, dissolution of matrix calcite, development of Fe- and Mn-rich gossan, crystallization of cerianite and accompanying negative Ce anomalies in secondary fluorocarbonates and phosphates, and increasing d18O values. These vertical changes demonstrate the importance of oxidizing meteoric water during the most recent modifications to the carbonatite stockwork. Scanning electron microscopy, energy dispersive spectroscopy, and electron probe microanalysis were used to investigate variations in mineral chemistry controlling the lateral complex-wide geochemical heterogeneity. HREE-enrichment in some peripheral zones can be attributed to an increase in the abundance of secondary REE phosphates (rhabdophane group, monazite, and fluorapatite), while HREE-enrichment in other zones is a result of HREE substitution in the otherwise LREE-selective fluorocarbonate minerals. Microprobe analyses show that HREE substitution is most pronounced in Ca-rich fluorocarbonates (parisite, synchysite, and mixed syntaxial varieties). Peripheral, late-stage HREE-enrichment is attributed to: 1) fractionation during early crystallization of LREE selective minerals, such as ancylite, carbocernaite, and Ca-REE fluorocarbonates in the central Bull Hill dike swarm, 2) REE liberated during breakdown of primary calcite and apatite with higher HREE/LREE ratios, and 3) differential transport of REE in fluids with higher PO43-/CO32- and F-/CO32- ratios, leading to phosphate and pseudomorphic fluorocarbonate mineralization. Supergene weathering processes were important at the stratigraphically highest peripheral REE occurrence, which consists of fine, acicular monazite, jarosite, rutile/pseudorutile, barite, and plumbopyrochlore, an assemblage mineralogically similar to carbonatite laterites in tropical regions.
DS1990-0416
1990
Donovan, R.N.Donovan, R.N.Southern midcontinent- Texas transect, surface bedrock geologyGeological Society of America (GSA) Abstracts with programs, South-Central, Vol. 22, No. 1, p. 5GlobalMidcontinent, Tectonics
DS1990-0417
1990
Donovan, R.N.Donovan, R.N., Busbey, A.B., Morgan, K.M., Denison, R.E., LidiakSouthern midcontinent-Texas transect overviewGeological Society of America (GSA) Annual Meeting, Abstracts, Vol. 22, No. 7, p. A192GlobalGeochronology, Geophysics
DS1990-1066
1990
Donovan, R.N.Morgan, K.M., Donovan, R.N.Southern midcontinent -Texas transect, lineament analysisGeological Society of America (GSA) Abstracts with programs, South-Central, Vol. 22, No. 1, p. 29GlobalMidcontinent, Tectonics
DS1987-0159
1987
Donovan, S.K.Donovan, S.K.The fit of the continents in the late PrecambrianNature, Vol. 327, No. 6118, May 14, pp. 139-140Southern AfricaPaleostructure, Pangea
DS1992-0379
1992
Donovan-Ealy, P.F.Donovan-Ealy, P.F., Hendricks, J.D.Gravity and magnetic anomalies associated with Tertiary volcanism and a Proterozoic crustal boundary, Hopi Buttes volcanic field, Navajo Nation, ArizonaGeological Society of America (GSA) Abstracts with programs, 1992 Annual, Vol. 24, No. 7, abstract p. A82ArizonaGeophysics -magnetics, volcanism.
DS2001-0385
2001
DonskayaGladkochub, D.P., Sklyarov, Donskaya, MazukabzovPetrology of gabbro dolerites from Neoproterozoic dike swarms in the Sharyzhalgai block - problem breakup...Petrology, Vol. 9, No. 6, pp. 560-75.RussiaTectonics - Rodinia supercontinent, Dike swarms
DS2001-0386
2001
DonskayaGladkochub, D.P., Sklyarov, Donskaya, Mazukabzov, et al.Petrology of gabbro dolerites from Neoproterozoic dike swarms in Sharyzhalgai Block with reference to problemPetrology, Vol.9, 6, pp. 560-75.Russia, SiberiaCraton - breakup of the Rodinia supercontinent, Magma - melt
DS200612-0467
2006
Donskaya, L.Gladkochub, D., Pisarevsky, S., Donskaya, L., Mazukabzov, A., Stanevich, A., Sklyarov, E.Siberian Craton and its evolution in terms of Rodinia hypothesis.Episodes, Vol. 29, 3, pp. 169-174.Russia, SiberiaCraton, genesis
DS200512-0864
2005
Donskaya, T.Poller, U., Gladkochub, D., Donskaya, T., Mazukabzov, A., Sklyarov, E., Todt, W.Multistage magmatic and metamorphic evolution in the southern Siberian craton: Archean and paleoproterozoic zircon ages revealed by SHRIMP and TIMS.Precambrian Research, Vol. 136, 3-4, pp. 353-368.Russia, SiberiaGeochronology
DS200712-0847
2006
Donskaya, T.A.Pisarevsky, S.A., Gladkochub, D.P., Donskaya, T.A., De Waeel, B., Mazukabzov, A.M.Paleomagnetism and geochronology of mafic dykes in south Siberia, Russia: the first precisely dated Permian paleomagnetic pole from the Siberian Craton.Geophysical Journal International, Vol. 167, 2, pp. 649-658.RussiaGeochronology
DS2001-0265
2001
Donskaya, T.V.Donskaya, T.V., Salnikova, Sklyarov, GladkochubEarly Proterozoic Post collision magmatism at the southern flank of the Siberian Craton: geochronological...Doklady, Vol.383, No. 1-2, Feb-Mar. pp. 125-8.Russia, SiberiaGeodynamic - magmatism, Geochronology
DS2002-0578
2002
Donskaya, T.V.Gladkochub, D.P., Donskaya, T.V., Mazukabzov, A.M., Sklyarov, E.V.The Urik Iya graben of the Sayan In lier of the Siberian Craton: new geochronologicalDoklady Earth Sciences, Vol. 386, 7, Sept-Oct.pp. 737-41.Russia, SiberiaGeochronology, Geodynamics, tectonics - not specific to diamonds
DS2002-1505
2002
Donskaya, T.V.Sklyarov, E.V., Gladkochub, D.P., Mazukabzov, A.M., Donskaya, T.V.Geological complexes in the margin of the Siberian Craton as indicators of the evolutionRussian Journal of Earth Science, Vol. 4, 3, JuneRussiaMagmatism, Gondwana
DS200512-0865
2005
Donskaya, T.V.Poller, U., Gladkochub, D.P., Donskaya, T.V., Mazukabzov, A.M., Sklyarov, E.V., Todt, W.Timing of Early Proterozoic magmatism along the southern margin of the Siberian Craton ( Kitoy area).Geological Society of America Special Paper, No. 389, pp. 215-226.RussiaMagmatism ( not specific to diamonds)
DS200612-0468
2006
Donskaya, T.V.Gladkochub, D.P., Wingate, M.T.D., Pisarevsky, S.A., Donskaya, T.V., Mazukababzov, Ponomarchuk, StanevichMafic intrusions in southwestern Siberia and implications for a Neoproterozoic connection with Laurentia.Precambrian Research, Vol. 147, 3-4, July 5, pp. 260-278.Russia, CanadaMagmatism
DS200612-0469
2006
Donskaya, T.V.Gladkochub, D.P., Wingate, M.T.D., Pisarevsky, S.A., Donskaya, T.V., Mazukabzov, Ponomarchuk, StanevichMafic intrusions in southwestern Siberia and implications for a Neoproterozoic connection with Laurentia.Precambrian Research, In press, availableRussia, SiberiaGeochronology, Biryusa, magmatism
DS200712-0363
2007
Donskaya, T.V.Gladkochub, D.P., Donskaya, T.V., Mazukabzov, A.M., Stanevich, A.M., Sklyarov, E.V., Ponomarchuk, V.A.Signature of Precambrian extension events in the southern Siberian Craton.Russian Geology and Geophysics, Vol. 48, pp. 17-31.RussiaDike swarm, rifting, Rodinia
DS200812-0413
2008
Donskaya, T.V.Gladkochub, D.P., Sklyarov, E.V., Donskaya, T.V., Stanevich, A.M., Mazukabzov, A.M.A period of global uncertainty ( Blank spot) in the Precambrian history of the southern Siberian Craton and the problem of the transproterozoic supercontinent.Doklady Earth Sciences, Vol. 421, 1, pp. 774-778.Russia, SiberiaTectonics
DS200912-0182
2009
Donskaya, T.V.Donskaya, T.V., Gladkochub, D.P., Pisarevsky, S.A., Poller, U., Mazukabov, A.M., Bayanova, T.B.Discovery of Archean crust within the Akitkan orogenic belt of the Siberian craton: new insight into its architecture and history.Precambrian Research, Vol. 170, 1-2, pp. 61-72.Russia, SiberiaTectonics
DS201012-0236
2010
Donskaya, T.V.Gladkochub, D.P., Pisarevsky, S.A., Ernst, R., Donskaya, T.V., Soderlund, U., Mazukabzov, A.M., Hanes, J.Large igneous province of about 1750 Ma in the Siberian Craton.Doklady Earth Sciences, Vol. 430, 2, pp. 163-167.RussiaMagmatism
DS201312-0315
2013
Donskaya, T.V.Gladkochub, D.P., Kostrovitskii, S.I., Donskaya, T.V., De Waele, B., Mazukabzov, A.M.Age of zircons from diamond bearing lamproites of the East Sayan as an indicator of known and unkonwn endogenous events in the south Siberian craton.Doklady Earth Sciences, Vol. 450, 2, June pp. 597-601.Russia, SayanLamproite
DS201712-2686
2017
Donskaya, T.V.Gladkochub, D.P., Donskaya, T.V., Sklyarov, E.V., Kotov, A.B., Vladykin, N.V., Pisarevsky, S.A., Larin, A.M., Salnikova, E.B., Saveleva, V.B., Sharygin, V.V., Starikova, A.E., Tolmacheva, E.V., Velikoslavinsky, S.D., Mazukabzov, A.M., Bazarova, E.P., KovaThe unique Katugin rare metal deposit ( southern Siberia): constraints on age and genesis.Ore Geology Reviews, in press available, 18p.Russia, Siberiadeposit - Katugin

Abstract: We report new geological, mineralogical, geochemical and geochronological data about the Katugin Ta-Nb-Y-Zr (REE) deposit, which is located in the Kalar Ridge of Eastern Siberia (the southern part of the Siberian Craton). All these data support a magmatic origin of the Katugin rare-metal deposit rather than the previously proposed metasomatic fault-related origin. Our research has proved the genetic relation between ores of the Katugin deposit and granites of the Katugin complex. We have studied granites of the eastern segment of the Eastern Katugin massif, including arfvedsonite, aegirine-arfvedsonite and aegirine granites. These granites belong to the peralkaline type. They are characterized by high alkali content (up to 11.8?wt% Na2O?+?K2O), extremely high iron content (FeO*/(FeO*?+?MgO)?=?0.96-1.00), very high content of most incompatible elements - Rb, Y, Zr, Hf, Ta, Nb, Th, U, REEs (except for Eu) and F, and low concentrations of CaO, MgO, P2O5, Ba, and Sr. They demonstrate negative and CHUR-close eNd(t) values of 0.0…-1.9. We suggest that basaltic magmas of OIB type (possibly with some the crustal contamination) represent a dominant part of the granitic source. Moreover, the fluorine-enriched fluid phases could provide an additional source of the fluorine. We conclude that most of the mineralization of the Katugin ore deposit occurred during the magmatic stage of the alkaline granitic source melt. The results of detailed mineralogical studies suggest three major types of ores in the Katugin deposit: Zr mineralization, Ta-Nb-REE mineralization and aluminum fluoride mineralization. Most of the ore minerals crystallized from the silicate melt during the magmatic stage. The accessory cryolites in granites crystallized from the magmatic silicate melt enriched in fluorine. However, cryolites in large veins and lens-like bodies crystallized in the latest stage from the fluorine enriched melt. The zircons from the ores in the aegirine-arfvedsonite granite have been dated at 2055?±?7?Ma. This age is close to the previously published 2066?±?6?Ma zircon age of the aegirine-arfvedsonite granites, suggesting that the formation of the Katugin rare-metal deposit is genetically related to the formation of peralkaline granites. We conclude that Katugin rare-metal granites are anorogenic. They can be related to a Paleoproterozoic (~2.05?Ga) mantle plume. As there is no evidence of the 2.05?Ga mantle plume in other areas of southern Siberia, we suggest that the Katugin mineralization occurred on the distant allochtonous terrane, which has been accreted to Siberian Craton later.
DS202007-1143
2020
Donskaya, T.V.Gladkochub, D.P., Donskaya, T.V.Geochemical composition of dolerites as an indicator of the distance of a dike swarm from the mantle plume center ( case study of Proterozoic dike swarms, Siberian craton).Doklady Earth Sciences, Vol. 491, pp. 243-246.Russia, Siberiadyke

Abstract: Based on investigation of Proterozoic mafic dike swarms of the Siberian Craton, we inferred how the geochemical and isotopic characteristics of dike swarms of dolerites of Large Igneous Provinces depend on their distance from the mantle plume head. It has been found that the dolerite parent melts near the mantle plume head correspond to OIB compositions. At significant distances from the plume, the initial melts of dolerites are generated in the subcontinental lithospheric mantle, which provides a wide range of their compositions differing from typical OIB and do not indicate directly the genetic relationship of these mafic rocks with the mantle plume.
DS200512-1230
2003
Donskiy, M.Zagnitko, V., Krydik, S., Donskiy, M.Isotopic geochemistry of carbonatites of Ukraine.Periodico di Mineralogia, (in english), Vol. LXX11, 1. April, pp. 153-159.Europe, UkraineGeochronology, Chernigovka Complex
DS1998-0358
1998
Doodson, A.Doodson, A., DePaolo, D.J., Kennedy, B.M.Helium isotopes in lithospheric mantle: evidence from Tertiary basalts Of the western USAGeochimica et Cosmochimica Acta, Vol. 62, No. 23/24, Dec. pp. 3775-87.Colorado Plateau, MantleLithosphere, Geochronology, Noble gases
DS1998-0160
1998
Dooley, J.Braun, J., Dooley, J., Goleby, B., Van der Hilst et al.Structure and evolution of the Australian continentAmerican Geophysical Union (AGU) Geodynamic Series, Vol. 26, 186p. app. $ 42.00AustraliaMantle - lithosphere, structure, Tectonics
DS1992-0380
1992
Dooley, K.Dooley, K.Geographic information systems in E and P computingGeobyte, Vol. 7, No. 5, pp. 36-40GlobalComputer, GIS
DS1995-1198
1995
Dooley, T.McClay, K., Dooley, T.Analogue models of pull apart basinsGeology, Vol. 23, No. 8, August pp. 711-714Andes, ArgentinaBasins, Tectonics
DS1998-0973
1998
Dooley, T.McClay, K.R., Dooley, T., Lewis, G.Analog modeling of progradational delta systemsGeology, Vol. 26, No. 9, Sept. pp. 772-4GlobalDelta systems, basins, model, Graben, Fold thrust, tectonics
DS200412-0105
2003
Doorgapershad, A.Barton, J.M., Barnett, W.P., Barton, E.S., Barnett, M., Doorgapershad, A., Twiggs, C., Klemd, B.R., Martin, J.The geology of the areas surrounding the Venetia kimberlite pipes, Limpopo belt, South Africa: a complex interplay of Nappe tectSouth African Journal of Geology, Vol. 106, 2-3, pp. 109-128.Africa, South AfricaDeposit - Venetia, tectonics
DS200412-0470
2003
Doorgapershad, A.Doorgapershad, A., Barnett, M., Twiggs, C., Martin, J., Millonig, L., Zenglein, R.Procedures used to produce a digitized geological mapping database of the area around the Venetia kimberlite pipes, Limpopo BeltSouth African Journal of Geology, Vol. 106, 2-3, pp. 103-108.Africa, South AfricaDeposit - Venetia, mapping
DS200912-0183
2009
Doornbos, C.Doornbos, C., Heaman, L.M., Doupe, J.P., England, J., Simonetti, A., Lejeunesse, P.The first integrated use of in situ U Pb geochronology and geochemical analyses to determine long distance transport of glacial erratics from maIn land Canada into western Arctic Archipelgo.Canadian Journal of Earth Sciences, Vol. 46, 2, pp. 101-122.Canada, Melville PeninsulaGeochronology - western Arctic Archipelago
DS1993-1292
1993
Doornbos, D.J.Rekdal, T., Doornbos, D.J.A modified form of diffraction tomography to image boundary structuresGeophysics, Vol. 58, No. 8, August pp. 1136-1147GlobalGeophysics -seismics, Tomography, Mantle
DS1993-1293
1993
Doornbos, D.J.Rekdal, T., Doornbos, D.J.A modified form of diffraction tomography to image boundary structuresGeophysics, Vol. 58, No. 8, August pp. 1136-1147.GlobalMantle, Tectonics, boundary structure
DS200912-0402
2009
Dopp, S.P.Koorneef, J.M., Davies, G.R., Dopp, S.P., Vukmanovic, Z., Nikogosian, I.K., Mason, P.R.D.Nature and timing of multiple metasomatic events in the sub-cratonic lithosphere beneath Labait, Tanzania.Lithos, In press availableAfrica, TanzaniaMetasomatism
DS1994-0442
1994
Doppelhammer, S.K.Doppelhammer, S.K., Hargraves, R.B.Paleomagnetism of Schuller and Franspoort kimberlite pipes in South Africa and an improved Premier pole.Precambrian Research, Vol. 69, No. 1-4, Oct. pp. 193-198.South AfricaGeophysics -Paleomagnetism, Deposit -Schuller, Franspoort
DS202007-1163
2019
Dora, M.L.Meshram, R.R., Dora, M.L., Naik, R., Shareef, M., Gopalakrishna, G., Moeshram, T., Baswani, S.R., Randive, K.R.A new find of calc-alkaline lamprophyres in Thanewasna area, western Bastar craton, India.Journal of Earth System Science, Vol. 128, 1, 7p. PdfIndiaminette

Abstract: Lamprophyre dykes within the granitoid and charnockite are reported for the first time from the Western Bastar Craton, Chandrapur district, Maharashtra. It shows porphyritic-panidiomorphic texture under a microscope, characterised by the predominance of biotite phenocrysts with less abundance of amphibole and clinopyroxene microphenocryst. The groundmass is composed more of K-feldspars over plagioclase, amphiboles, clinopyroxene, biotite, chlorite, apatite, sphene and magnetite. The mineral chemistry of biotite and magnesio-hornblende is indicative of minette variety of calc-alkaline lamprophyre (CAL), which is further supported by preliminary major oxides and trace element geochemistry. This unique association of CAL with granitoid provides an opportunity to study the spatio-temporal evolution of the lamprophyric magma in relation to the geodynamic perspective of the Bastar Craton.
DS1990-0418
1990
Dorais, M.J.Dorais, M.J.Compositional variations in pyroxenes and amphiboles of the Belknap Mountains complex, New Hampshire: evidence for the origin of silica-saturated alkaline rocksAmerican Mineralogist, Vol. 75, No. 9-10. Sept.-Oct. pp. 1092-1105GlobalMonteregian Hills, Alkaline rocks
DS1992-0381
1992
Dorais, M.J.Dorais, M.J., Floss, C.An ion and electron microprobe study of the mineralogy of enclaves and hostsyenites of the Red Hill Complex.Journal of Petrology, Vol. 33, pt. 5, pp. 1193-1218.GlobalAlkaline rocks
DS1996-0313
1996
Dorais, M.J.Cullers, R.L., Dorais, M.J., Berendsen, P., Chaudhuri, S.Mineralogy and petrology of Cretaceous subsurface lamproite sills, southeastern Kansas, USALithos, Vol. 38, pp. 185-206.KansasLamproite, Deposit -Ecco Ranch, Guess, Silver City, Rose Dome
DS1900-0184
1903
Doran, S.Doran, S.Diamonds in Painted DesertIndust. Rec. Oil Review., Vol. 3, No. 26, SEPT. 5TH. P. 6.United States, Arizona, Colorado PlateauDiamond Occurrence
DS1920-0067
1921
Doran, W.J.Doran, W.J.The Diamond DiggerBritish South Africa Annual, PP. 71-75.South AfricaHistory
DS201903-0502
2019
Doranti-Tiritan, C.da Silva, B.V., Hackspacher, P.C., Siqueira Riberio, M.C., Glasmacher, U.A., Goncalves, A.O., Doranti-Tiritan, C., de Godoy, D.F., Constantino, R.R.Evolution of the southwestern Angolan margin: episodic burial and exhumation is more realistic than long term denudation.International Journal of Earth Sciences, Vol. 108, pp. 89-113.Africa, Angolathermochronology

Abstract: There are two main points of view regarding how continental margins evolve. The first one argues that the present-day margins have been developed by long-term denudation since a major exhumation episode, probably driven by rifting or another relevant tectonic event. The second one argues that continental margins underwent alternating burial and exhumation episodes related to crustal tectonic and surface uplift and subsidence. To demonstrate that the proximal domain of the southwestern Angolan margin has evolved in a polycyclic pattern, we present a review of geological and thermochronological information and integrate it with new combined apatite fission-track and (U-Th)/He data from Early Cretaceous volcanic and Precambrian basement samples. We also provide hypotheses on the possible mechanisms able to support the vertical crustal movements of this margin segment, which are also discussed based on some modern rifting models proposed for Central South Atlantic. The central apatite fission-track ages range from 120.6?±?8.9 to 272.9?±?21.6 Ma, with the mean track lengths of approximately 12 µm. The single-grain apatite (U-Th)/He ages vary between 52.2?±?1 and 177.2?±?2.6 Ma. The integration of the thermochronological data set with published geological constraints supports the following time-temperature evolution: (1) heating since the Carboniferous-Permian, (2) cooling onset in the Early Jurassic, (3) heating onset in the Early Cretaceous, (4) cooling onset in the Mid- to Late Cretaceous, (5) heating onset in the Late Cretaceous, and (6) cooling onset in the Oligocene-Miocene. The thermochronological data and the geological constraints, support that the proximal domain of the southwestern Angolan margin was covered in the past by pre-, syn-, and post-rift sediments, which were eroded during succeeding exhumation events. For this margin segment, we show that a development based on long-term denudation is less realistic than one based on burial and exhumation episodes during the last 130 Myr.
DS2000-0241
2000
Dorbath, C.Dorbath, C., Masson, F.Composition of crust and upper mantle in Central Andes: inferred from P wave velocity and Poisson's ratio.Tectonophysics, Vol. 327, No. 3-4, Dec.15, pp. 213-224.South America, AndeanLithosphere, Geophysics - seismics
DS1999-0140
1999
Dorbath, L.Comte, D., Dorbath, L., Meneses, C.A double layered seismic zone in Africa, northern ChileGeophysical Research Letters, Vol. 26, No. 13, July 1, pp. 1965-8.Africa, ChileGeophysics - seismics
DS1989-0119
1989
Dorbes, J.Bille, C., Chapoulie, R., Dorbes, J., Schvoerer, M.Reconnaissance d'un diamant de synthese de Beers parmi d'autres gemmes grace a la cathodluminescence.(in French)Revue de Gemmologie, (in French), No. 100, pp. 19-21GlobalNatural diamonds, Luminesence
DS1987-0548
1987
Dorbor, J.Onstott, T.C., Dorbor, J.40Ar-39 Ar and paleomagnetic resulots from Liberia and the Precambrian APW dat a base for the West African shieldJournal of African Earth Sciences, Vol. 6, No. 4, pp. 537-552GlobalTectonics, Geochronology, Argon, Geophysics
DS2001-1263
2001
Dorbor, J.Wright, L., Dorbor, J.Liberia cooperates in study of terrorists in diamond trade.Mining Annual Review, 3p.GlobalCountry - overview, economics, mining, Overview - brief
DS1987-0160
1987
Dorbor, J.K.Dorbor, J.K.The Precambrian of Liberia: some chemical features of LiberiangranitoidsThe Compass, Vol. 64, No. 4, pp. 244-263GlobalGeneral geology, Background
DS1990-1085
1990
Dorbor, J.K.Nair, A.M., Dorbor, J.K.Industrial minerals of LiberiaIndustrial Minerals, No. 270, March p. 137. ( 1 page overview)GlobalBrief overview, Diamonds mentioned
DS201809-2032
2018
Dorbor, J.K.Gunn, A.G., Dorbor, J.K., Mankelow, J.M., Lusty, P.A.J., Deady, E.A., Shaw, R.A.A review of the mineral potential of Liberia.Ore Geology Reviews, Vol. 101, pp. 413-431.Africa, Liberiadiamonds

Abstract: The Republic of Liberia in West Africa is underlain mostly by Precambrian rocks of Archaean (Liberian) age in the west and of Proterozoic (Eburnean) age in the east. By analogy with similar terranes elsewhere in the world, and in West Africa in particular, the geology of Liberia is favourable for the occurrence of deposits of a wide range of metals and industrial minerals, including gold, iron ore, diamonds, base metals, bauxite, manganese, fluorspar, kyanite and phosphate. Known gold deposits, mostly orogenic in style, occur widely and are commonly associated with north-east-trending regional shear zones. Gold mining commenced at the New Liberty deposit in western Liberia in 2015, while significant gold resources have also been identified at several other sites in both Archaean and Proterozoic terranes. Liberia has large resources of itabirite-type iron ores, most of which are located in the Liberian terrane, and was the largest producer in Africa prior to the onset of civil war in 1989. Production of iron ore is currently restricted to a single mine, Yekepa, in the Nimba Range. Other important deposits, some of them previously mined, include Bong, the Western Cluster, Putu and Goe Fantro. There is a long history of alluvial diamond production in western and central Liberia, together with more than 160 known occurrences of kimberlite. Most of the known kimberlites occur in three clusters of small pipes and abundant dykes, located at Kumgbor, Mano Godua and Weasua, close to the border with Sierra Leone. Many of these are considered to be part of a single province that includes Jurassic age diamondiferous kimberlites in Sierra Leone and Guinea. Deposits and occurrences of a wide range of other metals and industrial minerals are also known. Several of these have been worked on a small scale in the past, mainly by artisanal miners, but most are poorly known in detail with sub-surface information available at only a few localities. By comparison with most other countries in West Africa, the geology of Liberia is poorly known and there has been very little systematic exploration carried out for most commodities other than gold, iron ore and diamonds since the 1960s and 1970s. Further detailed field and laboratory investigations using modern techniques are required to properly evaluate the potential for the occurrence of economic deposits of many minerals and metals in a variety of geological settings. Digital geological, geochemical, geophysical and mineral occurrence datasets, including new national airborne geophysical survey data, provide a sound basis for the identification of new exploration targets, but in almost every part of the country there is a need for new and more detailed geological surveys to underpin mineral exploration.
DS1986-0423
1986
Dorda, J.Karwowski, L., Dorda, J.The mineral forming environment of Marmaros diamonds. *POLMineralogia Polonica, *POL, Vol. 17, No. 1, pp. 3-16GlobalPetrology, Silicates
DS1999-0215
1999
Dore, A.G.Fichler, C., Rundhovde, E., Dore, A.G.Regional tectonic interpretation of image enhanced gravity and magneticdat a covering mid-Norwegian shelfTectonophysics, Vol. 306, No. 2, June 15, pp. 183-98.NorwayTectonics, Geophysics - gravity
DS200512-0660
2005
Dore, A.G.Lundin, E.R., Dore, A.G.Fixity of the Iceland 'hotspot' on the Mid-Atlantic Ridge: observational evidence, mechanisms, and implications for Atlantic volcanic margins.Plates, Plumes, and Paradigms, pp. 627-652. ( total book 861p. $ 144.00)Europe, IcelandTectonics
DS201911-2574
2019
Dore, A.G.Wilson, R.W., Huseman, G.A., Buiter, S.J.H., McCaffrey, K.J.W., Dore, A.G.Fifty years of the Wilson Cycle concept in plate tectonics: an overview.IN: Cycle Concepts in Plate Tectonics, editors Wilson and Houseman , Geological Society of London special publication 470, pp. 1-17. pdfMantleplate tectonics

Abstract: It is now more than 50 years since Tuzo Wilson published his paper asking ‘Did the Atlantic close and then re-open?’. This led to the ‘Wilson Cycle’ concept in which the repeated opening and closing of ocean basins along old orogenic belts is a key process in the assembly and breakup of supercontinents. This implied that the processes of rifting and mountain building somehow pre-conditioned and weakened the lithosphere in these regions, making them susceptible to strain localization during future deformation episodes. Here we provide a retrospective look at the development of the concept, how it has evolved over the past five decades, current thinking and future focus areas. The Wilson Cycle has proved enormously important to the theory and practice of geology and underlies much of what we know about the geological evolution of the Earth and its lithosphere. The concept will no doubt continue to be developed as we gain more understanding of the physical processes that control mantle convection and plate tectonics, and as more data become available from currently less accessible regions.
DS1999-0372
1999
DorendorfKoloskov, A.V., Flerov, G.B., Seliverstov, DorendorfPotassic volcanics of central Kamchatka and the Late Cretaceous Paleogene Kuril Kamchatka alkaline Province.Petrology, Vol. 7, No. 5, pp. 527-RussiaAlkaline rocks
DS2001-0193
2001
Dorendorf, F.Churkikova, T., Dorendorf, F., Worner, G.Sources and fluids in the mantle wedge below Kamchatka, evidence from across arc geochemical variation.Jour. Petrol., Vol. 42, No. 8, pp. 1567-93.Russia, KamchatkaMantle - geochemistry
DS1998-1534
1998
DorfmanVeksler, I.V., Petibon, Jenner, Dorfman, DingwellTrace element partitioning in immiscible silicate carbonate liquid systems:an initial experimenatal ...Journal of Petrology, Vol. 39, No. 11-12, Nov-Dec. pp. 2095-2104.MantleCarbonatite, Petrology - experimental
DS1997-0284
1997
Dorfman, A.Dorfman, A., Veksler, I., Dingwell, D.Study of element distribution between immiscible silicate and carbonate liquid using a centrifuge auto..Geological Association of Canada (GAC) Abstracts, POSTER.GlobalBlank
DS1990-0792
1990
Dorfman, A.M.Kadik, A.A., Dorfman, A.M., Bagdasarov, N.Sh., Lebedev, Ye.B.Influence of pyroxenes on the melt distribution in the intergranular spacein a peridotiteGeochemical Int, Vol. 27, No. 3, pp. 131-134RussiaPyroxenes, Mantle melt
DS1991-0395
1991
Dorfman, M.D.Dorfman, M.D., Kapustin, Yu.L.Liquation phenomena in a carbonate dike of the Mushugai-Khuduk complex, MongoliaSoviet Geology and Geophysics, Vol. 32, No. 8, pp. 79-82China, MongoliaCarbonatite, Petrography
DS200812-0301
2008
Dorfman, S.Duffy, T.S., Kubo, A., Shieh, S., Dorfman, S., Prakapenka, V.High pressure phases in the MgO FeO Al2O3 SiO2 system: implications for the deep mantle.Goldschmidt Conference 2008, Abstract p.A230.MantlePetrology
DS201606-1130
2016
Dorfman, S.M.Zhang, Z., Dorfman, S.M., Labidi, J., Zhang, S., Li, M., Manga, M., Stixrude, L., McDonough, W.F., Williams, Q.Primordial metallic melt in the deep mantle.Geophysical Research Letters, Vol. 43, 8, pp. 3693-3697.MantleMelting

Abstract: Seismic tomography models reveal two large low shear velocity provinces (LLSVPs) that identify large-scale variations in temperature and composition in the deep mantle. Other characteristics include elevated density, elevated bulk sound speed, and sharp boundaries. We show that properties of LLSVPs can be explained by the presence of small quantities (0.3-3%) of suspended, dense Fe-Ni-S liquid. Trapping of metallic liquid is demonstrated to be likely during the crystallization of a dense basal magma ocean, and retention of such melts is consistent with currently available experimental constraints. Calculated seismic velocities and densities of lower mantle material containing low-abundance metallic liquids match the observed LLSVP properties. Small quantities of metallic liquids trapped at depth provide a natural explanation for primitive noble gas signatures in plume-related magmas. Our model hence provides a mechanism for generating large-scale chemical heterogeneities in Earth's early history and makes clear predictions for future tests of our hypothesis.
DS201607-1323
2016
Dorfman, S.M.Zhang, Z., Dorfman, S.M., Labidi, J., Zhang, S., Li, M., Manga, M., Stixrude, L., McDonough, W.F., Williams, Q.Primordial metallic melt in the deep mantle.Geophysical Research Letters, Vol. 43, 8, pp. 3693-3699.MantleMelting

Abstract: Seismic tomography models reveal two large low shear velocity provinces (LLSVPs) that identify large-scale variations in temperature and composition in the deep mantle. Other characteristics include elevated density, elevated bulk sound speed, and sharp boundaries. We show that properties of LLSVPs can be explained by the presence of small quantities (0.3 -3%) of suspended, dense Fe-Ni-S liquid. Trapping of metallic liquid is demonstrated to be likely during the crystallization of a dense basal magma ocean, and retention of such melts is consistent with currently available experimental constraints. Calculated seismic velocities and densities of lower mantle material containing low-abundance metallic liquids match the observed LLSVP properties. Small quantities of metallic liquids trapped at depth provide a natural explanation for primitive noble gas signatures in plume-related magmas. Our model hence provides a mechanism for generating large-scale chemical heterogeneities in Earth's early history and makes clear predictions for future tests of our hypothesis.
DS201804-0686
2018
Dorfman, S.M.Dorfman, S.M., Badro, J., Nabiel, F., Prakapenka, V.B., Cantoni, M., Gillet, P.Carbonate stability in the reduced lower mantle.Earth and Planteray Science Letters, Vol. 489, pp. 84-91.Mantlecarbonate

Abstract: Carbonate minerals are important hosts of carbon in the crust and mantle with a key role in the transport and storage of carbon in Earth's deep interior over the history of the planet. Whether subducted carbonates efficiently melt and break down due to interactions with reduced phases or are preserved to great depths and ultimately reach the core-mantle boundary remains controversial. In this study, experiments in the laser-heated diamond anvil cell (LHDAC) on layered samples of dolomite (Mg,?Ca)CO3 and iron at pressure and temperature conditions reaching those of the deep lower mantle show that carbon-iron redox interactions destabilize the MgCO3 component, producing a mixture of diamond, Fe7C3, and (Mg,?Fe)O. However, CaCO3 is preserved, supporting its relative stability in carbonate-rich lithologies under reducing lower mantle conditions. These results constrain the thermodynamic stability of redox-driven breakdown of carbonates and demonstrate progress towards multiphase mantle petrology in the LHDAC at conditions of the lowermost mantle.
DS201910-2281
2019
Dorfman, S.M.Liu, J., Dorfman, S.M., Lv, M., Li, J., Xhu, F., Kono, Y.Loss of immiscible nitrogen from metallic melt explains Earth's missing nitrogen.Geochemical Perspectives Letters, Vol. 11, pp. 18-22.Mantlenitrogen

Abstract: Nitrogen and carbon are essential elements for life, and their relative abundances in planetary bodies are important for understanding planetary evolution and habitability. The high C/N ratio in the bulk silicate Earth (BSE) relative to chondrites has been difficult to explain through partitioning during core formation and outgassing from molten silicate. Here we propose a new model that may have released nitrogen from the metallic cores of accreting bodies during impacts with the early Earth. Experimental observations of melting in the Fe-N-C system via synchrotron X-ray radiography of samples in a Paris-Edinburgh press reveal that above the liquidus, iron-rich melt and nitrogen-rich liquid coexist at pressures up to at least 6 GPa. The combined effects of N-rich supercritical fluid lost to Earth’s atmosphere and/or space as well as N-depleted alloy equilibrating with the magma ocean on its way to the core would increase the BSE C/N ratio to match current estimates.
DS202002-0206
2020
Dorfman, S.M.McCammon, C., Bureau, H., Cleaves II, H.J., Cottrell, E., Dorfman, S.M., Kellogg, L.H., Li, J., Mikhail, S., Moussallam, Y., Sanloup, C., Thomson, A.R., Brovarone, A.V.Deep Earth carbon reactions through time and space. ( mentions diamond)American Mineralogist, Vol. 105, pp. 22-27.Mantlesubduction

Abstract: Reactions involving carbon in the deep Earth have limited manifestations on Earth's surface, yet they have played a critical role in the evolution of our planet. The metal-silicate partitioning reaction promoted carbon capture during Earth's accretion and may have sequestered substantial carbon in Earth's core. The freezing reaction involving iron-carbon liquid could have contributed to the growth of Earth's inner core and the geodynamo. The redox melting/freezing reaction largely controls the movement of carbon in the modern mantle, and reactions between carbonates and silicates in the deep mantle also promote carbon mobility. The 10-year activity of the Deep Carbon Observatory has made important contributions to our knowledge of how these reactions are involved in the cycling of carbon throughout our planet, both past and present, and has helped to identify gaps in our understanding that motivate and give direction to future studies.
DS202009-1624
2020
Dorfman, S.M.Dorfman, S.M., Potapkin, V., Lv, M., Greenberg, E., Kupenko, I., Chumakov, A.I., Bi, W., Alp, E.E., Liu, J., Magrez, A., Dutton, S.E., Cava, R.J., McCammon, C.A., Gillet, P.Effects of composition and pressure on electronic states of iron in bridgmanite.American Mineralogist, Vol. 105, pp. 1030-1039. pdfMantleredox

Abstract: Electronic states of iron in the lower mantle's dominant mineral, (Mg,Fe,Al)(Fe,Al,Si)O3 bridgmanite, control physical properties of the mantle including density, elasticity, and electrical and thermal conductivity. However, the determination of electronic states of iron has been controversial, in part due to different interpretations of Mössbauer spectroscopy results used to identify spin state, valence state, and site occupancy of iron. We applied energy-domain Mössbauer spectroscopy to a set of four bridgmanite samples spanning a wide range of compositions: 10-50% Fe/total cations, 0-25% Al/total cations, 12-100% Fe3+/total Fe. Measurements performed in the diamond-anvil cell at pressures up to 76 GPa below and above the high to low spin transition in Fe3+ provide a Mössbauer reference library for bridgmanite and demonstrate the effects of pressure and composition on electronic states of iron. Results indicate that although the spin transition in Fe3+ in the bridgmanite B-site occurs as predicted, it does not strongly affect the observed quadrupole splitting of 1.4 mm/s, and only decreases center shift for this site to 0 mm/s at ~70 GPa. Thus center shift can easily distinguish Fe3+ from Fe2+ at high pressure, which exhibits two distinct Mössbauer sites with center shift ~1 mm/s and quadrupole splitting 2.4-3.1 and 3.9 mm/s at ~70 GPa. Correct quantification of Fe3+/total Fe in bridgmanite is required to constrain the effects of composition and redox states in experimental measurements of seismic properties of bridgmanite. In Fe-rich, mixed-valence bridgmanite at deep-mantle-relevant pressures, up to ~20% of the Fe may be a Fe2.5+ charge transfer component, which should enhance electrical and thermal conductivity in Fe-rich heterogeneities at the base of Earth's mantle.
DS202012-2253
2020
Dorfman, S.M.Tian, D., Lv, M., Wei, S.S., Dorfman, S.M., Shearer, P.M.Global variations of Earth's 520- and 550-km discontinuities.Earth and Planetary Letters, Vol. 552, 116600, 13p. PdfMantlecore-mantle boundary

Abstract: We investigate seismic discontinuities in the mantle transition zone (MTZ) by analyzing SS precursors recorded at global seismic stations. Our observations confirm the global existence of the 520-km discontinuity. Although substantial regional depth variations in the 520-km discontinuity are generally correlated with temperature in the mid-MTZ, they cannot be fully explained by the Clapeyron slope of the wadsleyite-ringwoodite phase transition, suggesting both thermal and compositional heterogeneities in the MTZ. A second discontinuity at ~560-km depth, previously interpreted as splitting of the 520-km discontinuity, is most commonly detected in cold subduction zones and hot mantle regions. The depth separation between the 520- and 560-km discontinuities varies from ~80 km in cold regions to ~40 km in hot areas. The exsolution of calcium-perovskite (Ca-pv) from majorite garnet has been proposed to explain the velocity and density changes across the 560-km discontinuity. However, the gradual exsolution of perovskite and partitioning of Ca and Al between perovskite and garnet appear inconsistent with the relatively “sharp” discontinuity in seismic observations and thus need to be revisited in the future. Nevertheless, because the only known transition in major minerals at this depth in the MTZ is the formation of Ca-pv, the existence of the 560-km discontinuity may imply localized high calcium concentrations in the mid-MTZ possibly related to the recycling of oceanic crust.
DS201710-2278
2017
Doria, G.Wolfe, A.P., Reyes, A.V., Royer, D.L., Greenwood, D.R., Doria, G., Gagen, M.H., Siver, P.A., Westgate, J.A.Middle Eocene CO2 and climate reconstructed from the sediment fill of a subarctic kimberlite Maar.Geology , Vol. 45, 7, pp. 619-622.Canada, Northwest Territoriesdeposit - Giraffe

Abstract: Eocene paleoclimate reconstructions are rarely accompanied by parallel estimates of CO2 from the same locality, complicating assessment of the equilibrium climate response to elevated CO2. We reconstruct temperature, precipitation, and CO2 from latest middle Eocene (ca. 38 Ma) terrestrial sediments in the posteruptive sediment fill of the Giraffe kimberlite in subarctic Canada. Mutual climatic range and oxygen isotope analyses of botanical fossils reveal a humid-temperate forest ecosystem with mean annual temperatures (MATs) more than 17 °C warmer than present and mean annual precipitation ~4× present. Metasequoia stomatal indices and gas-exchange modeling produce median CO2 concentrations of ~630 and ~430 ppm, respectively, with a combined median estimate of ~490 ppm. Reconstructed MATs are more than 6 °C warmer than those produced by Eocene climate models forced at 560 ppm CO2. Estimates of regional climate sensitivity, expressed as ?MAT per CO2 doubling above preindustrial levels, converge on a value of ~13 °C, underscoring the capacity for exceptional polar amplification of warming and hydrological intensification under modest CO2 concentrations once both fast and slow feedbacks become expressed.
DS1996-0376
1996
Dorian, J.Dorian, J.Minerals and mining in the transitional economiesLmj, Emerging Markets Issue, Vol. 327, No. 8398, Oct. 4, pp. 15, 17, 19, 20.GlobalEconomics, Legislation
DS1986-0190
1986
Dorian, J.P.Dorian, J.P., Clark, A.L.Value of tectonic regions in the United StatesMathematical Geology, Vol. 18, No. 4, May pp. 385-400GlobalTectonics
DS1988-0177
1988
Dorian, J.P.Dorian, J.P., Clark, A.L., Sun Yi-Ying, Zhou Zou-Xia, Li Ji-LiangMineral resources of China: apparent controls on distributionGeoJournal, Vol. 17, No. 3, pp. 373-388ChinaOverview of tectonic/metalogeny no ref. to diamond
DS1991-0396
1991
Dorian, J.P.Dorian, J.P.USSR-MONGOLIA... a minerals association about to endResources Policy, Vol. 17, No. 1, March pp. 42-53RussiaEconomics, Relationship to Mongolia
DS1993-0369
1993
Dorian, J.P.Dorian, J.P.Minerals and mining in KazakhstanMining Engineering, Vol. 45, No. 11, November pp. 1363-1367Kazakhstan, RussiaCountry profile, Overview of geology, mining
DS1994-0443
1994
Dorian, J.P.Dorian, J.P., Humphreys, H.B.Economic impacts of mining.. a changing role in the transitionaleconomies.Natural Resources Forum, Vol. 18, No. 1, February, pp. 17-29.China, Russia, Commonwealth of Independent States (CIS), RussiaMining, Economics
DS1996-0377
1996
Dorian, P.S.Dorian, P.S., Kort, P.S.Joint mineral ventures in the former Soviet Union: prospects, problems andrealitiesNatural Resources forum, Vol. 20, No. 3, Aug. pp. 199-215Russia, Commonwealth of Independent States (CIS)Legal, Mining
DS200712-0267
2007
Dorijnamjaa, D.Dorijnamjaa, D., Kondratov, L.S., Voinkov, D.M., Amarsaikhan, Ts.Specific gas composition of the absorbed form in impatites of the diamond bearing Mongolian astropipes.Plates, Plumes, and Paradigms, 1p. abstract p. A231.Asia, MongoliaAgit Khangay, Khuree Mandal Tsenkher, Bayan Khuree
DS1996-0301
1996
Dorin, D.Corriveau, L., Tellier, M., Dorin, D., Amelin, Y.Le dyke de minette de Rivard et le complexe gneissique cuprifrer de Bondy:implications tectoniques....Geological Survey of Canada (GSC) Open File, No. 3078, 73p.Quebec, GrenvilleMinettes
DS1999-0172
1999
Doring, J.Doring, J., Gotze, H.J.The isostatic state of the southern Urals crustGeol. Rundsch., Vol. 87, No. 4, Mar. pp. 500-10.Russia, UralsGeophysics - geodynamics, Tectonics
DS200612-0345
2006
Dorjnamjaa, D.Dorjnamjaa, D., Selenge, D., Garanin, K.V.Diamond bearing astropipes in Mongolia their recognition and characteristics.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1. abstract only.Asia, MongoliaUHP Breccia pipes
DS200612-0346
2006
Dorjnamjaa, D.Dorjnamjaa, D., Tomurkhuu, D., Davaadorj, T.The geotectonic evolution and metallogeny of Mongolia during the Precambrian Phanerozoic time.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.Asia, MongoliaTectonics
DS201012-0164
2010
Dorjnamjaa, D.Dorjnamjaa, D., Selenge, D., Amarsaikhan, T., Enkhbaatar, B.Some new scientific facts on the diamond and gold forming astropipe geostructures of Mongolia.Goldschmidt 2010 abstracts, PosterAsia, MongoliaMeteorite
DS201709-1980
2011
Dorjnamjaa, D.Dorjnamjaa, D., Voinkov, D.M., Kondratov, L.S., Selenge, D., Altanshagai, G., Enkhbatar, B.Concerning diamond and gold bearing astropipes of Mongolia.International Journal of Astronomy and Astrophysics, Vol. 1, pp. 98-104.Asia, Mongoliaastropipes, impact craters

Abstract: In this paper we present summation of eighteen year’s investigation of the all gold and diamond-bearing astropipes of Mongolia. Four astropipe structures are exemplified by the Agit Khangay (10 km in diameter, 470 38' N; 960 05' E), Khuree Mandal (D=11 km; 460 28' N; 980 25' E), Bayan Khuree (D=1 km; 440 06' N; 1090 36' E), and Tsenkher (D=7 km; 980 21' N; 430 36' E) astropipes of Mongolia. Detailed geological and gas-geochemical investigation of the astropipe structures show that diamond genesis is an expression of collision of the lithospheric mantle with the explosion process initiated in an impact collapse meteor crater. The term "astropipes" (Dorjnamjaa et al., 2010, 2011) is a neologism and new scientific discovery in Earth science and these structures are unique in certain aspects. The Mongolian astropipes are genuine "meteorite crater" structures but they also contain kimberlite diamonds and gold. Suevite-like rocks from the astropipes contain such minerals, as olivine, coesite, moissanite (0,6 mm), stishovite, coesite, kamacite,tektite, khamaravaevite (mineral of meteorite titanic carbon), graphite-2H, khondrite, picroilmenite, pyrope, phlogopite, khangaite (tektite glass, 1,0-3,0 mm in size), etc. Most panned samples and hand specimens contain fine diamonds with octahedrol habit (0, 2-2,19 mm, 6,4 mg or 0,034-0,1 carat) and gold (0,1-5 g/t). Of special interest is the large amount of the black magnetic balls (0,05-5,0 mm) are characterized by high content of Ti, Fe, Co, Ni, Cu, Mn, Mg, Cd, Ga, Cl, Al, Si, K. Meanwhile, shatter cones (size approx. 1.0 m) which are known from many meteorite craters on the Earth as being typical of impact craters were first described by us Khuree Mandal and Tsenkher astropipe structures. All the described meteorite craters posses reliable topographic, geological, mineralogical, geochemical, and aerospace mapping data, also some geophysical and petrological features (especially shock metamorphism) have been found, all of which indicate that these structures are a proven new type of gold-diamond-bearing impact structure, termed here "astropipes". The essence of the phenomenon is mantle manifestation and plume of a combined nuclear-magma-palingenesis interaction.
DS201412-0202
2014
Dorkin, G.Dorkin, G.The regional relationships of the different gravel deposits in the Middle Orange region, northern Cape, South Africa.GSSA Kimberley Diamond Symposium and Trade Show provisional programme, Sept. 10-12, POSTERAfrica, South AfricaMiddle Orange River
DS201610-1856
2016
Dorkin, G.De Wit, M.C.J., Dorkin, G., Morris, D.The alluvial diamonds deposits … of the north west province and the Lower Val-Middle Orange Basin.IGC 35th., Field Trip Guide pre-6 Aug. 22-27, 45p. PdfAfrica, South AfricaGuidebook - alluvials
DS1996-0378
1996
Dorling, S.L.Dorling, S.L., Dentith, M.C., Groves, D.I., Playford, P.Heterogeneous brittle deformation in the Devonian carbonate rocks of the Pilbara range, Canning Basin...Australian Journal of Earth Sciences, Vol. 43, No. 1, Feb. pp. 15-20.AustraliaLennard Shelf, Structure, faulting, tectonics
DS1991-0397
1991
Dorn, R.I.Dorn, R.I.Rock varnishAmerican Scientist, Vol. 79, No. 6, Nov.Dec. pp. 542-560GlobalRock varnish, Overview
DS1991-1346
1991
Dorn, R.I.Phillips, F.M., Dorn, R.I.New methods for dating geomorphic surfaces.. Penrose Conference reportGsa Today, Vol. 1, No. 5, May p. 102GlobalGeomorphology, Age determinations
DS1995-0433
1995
Dorn, R.I.Dorn, R.I.Digital processing of back scatter electron imagery: a microscopic approach to quantifying chemical weatheringGeological Society of America (GSA) Bulletin, Vol. 107, No. 6, June pp. 725-741HawaiiWeathering, backscatter electron (BSE) imaging imagery
DS1998-0359
1998
Dorn, R.I.Dorn, R.I.Rock coatingsElsevier, Dev. Earth Sci. Proc, No. 6, 429pGlobalGeochemistry, Crusts, carbonates, skins, varnish, films, nitrates
DS1910-0176
1911
Dornbach, P.Dornbach, P.Dernburg und die Sued West Afrika DiamantenfrageBerlin: Deutsche Kolonialverlag, Southwest Africa, NamibiaDiamond, Politics
DS201911-2518
2019
Dorneles, N.T.de Almeida Morales, B.A., de Almeida, D.D.P.M., Koester, E., da Rocha, A.M.R., Dorneles, N.T., da Rosa, M.B., Martins, A.A.Mineralogy, whole-rock geochemistry and C, O isotopes from Passo Feio carbonatite, Sul-Riograndense shield, Brazil.Journal of South American Earth Sciences, Vol. 94, 102208 13p. PdfSouth America, Brazilcarbonatite

Abstract: Carbonatites are peculiar igneous rocks, consisting mainly of greater than 50% carbonate minerals, which arouse an economic interest due to the potentiality of high phosphate content and Light Rare Earth Elements (LREE) associated with their occurrence. The Passo Feio Carbonatite (PFC) is located 17?km Southwest of Caçapava do Sul city and constitutes NW dipping body, which is interposed with Passo Feio Formation metamorphic rocks. The PFC varies texturally from massive to foliated, being mainly composed of calcites and dolomites and on a smaller scale by apatites, phlogopites and tremolites. The opaque minerals correspond to hematites, magnetites, pyrites and barites, while the accessory minerals are represented by zircons, monazites- (Ce) and aeschynites- (Ce). Probably those REE mineral phases correspond to a hydrothermal stage, with the REE remobilization from apatites into those latter REE-rich mineral phases - this hypothesis is corroborated by geochemistry, mineral chemistry and microtextures found. Considering the results of mineral chemistry and taking into account the textural criteria, it was possible to classify carbonatite as an alvikite, with geochemical patterns that do not indicate economic potential for REE. However, soil geochemistry showed an important enrichment in REE, reflecting a probable concentration of monazites- (Ce) and aeschynites- (Ce), and because of this, it was possible to establish a zone in which the Passo Feio Carbonatite would probably be extended. In the stable isotope analyzes, the d13C values varied between -4.14 and -3.89‰ while those of d18O between 10.01 and 11.32‰ which can be attributed to the cooling of the magma itself, without suggesting metamorphic processes or subsequent changes. The deformation found in this carbonatite was probably developed in late-magmatic conditions, guided by tectonics associated with horizontal movements in shear zones. Thus, this work suggests that this carbonatite was the product of the reactivation of mantle sources, within a post-collision magmatic context of the Sul-Riograndense Shield.
DS201012-0594
2010
Dorofeev, S.A.Posukhova, T.V., Dorofeev, S.A., Gao, Y.Mineralogy of the wastes from diamond bearing mines. Arkangelsk LiaoninInternational Mineralogical Association meeting August Budapest, abstract p. 349.Russia, ChinaMining - recycling
DS1997-0839
1997
Dorofeeva, V.A.Naumov, V.B., Kovalenko, V.I., Dorofeeva, V.A.Magmatic volatile components and their role in the formation of ore formingfluidsGeology of Ore Deposits, Vol. 39, No. 6, pp. 451-460RussiaMagma, Genesis
DS2002-0895
2002
Dorofeeva, V.A.Kovalenko, V.I., Naumov, V.B., Yarmolyuk, V.V., Dorofeeva, V.A., MigdisovBalance of H2O and Cl between the Earth's mantle and outer shellsGeochemistry International, Vol. 40, 10, Oct. pp. 943-71.MantleWater, chlorine
DS200612-0739
2006
Dorofeeva, V.A.Kovalenko, V.I., Naumov, V.B., Girnis, A.V., Dorofeeva, V.A., Yarmolyuk, V.V.Composition and chemical structure of oceanic mantle plumes.Petrology, Vol. 14, 5, pp. 452-476.MantleGeochemistry - hot spots
DS200712-0578
2007
Dorofeeva, V.A.Kovalenko, V.I., Naumov, V.B., Girnis, A.V., Dorofeeva, V.A., Yarmoluk, V.V.Average contents of incompatible and volatile components in depleted, oceanic plume, and within plate continental mantle types.Doklady Earth Sciences, Vol. 445, 6, pp. DOI:10.1134/S1028334 X07060116MantleGeochemistry - plumes
DS201012-0409
2009
Dorofeeva, V.A.Kovalenko, V.I., Naumov, V.B., Girnis, A.V., Dorofeeva, V.A., Yarmolyuk, V.V.Average compositions of magmas and mantle sources of Mid-Ocean Ridges and intraplate Oceanic and Continental settings estimated from the dat a of melt inclusionsDeep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., p.35-78,MantleGlasses of basalts
DS201012-0529
2009
Dorofeeva, V.A.Naumov, V.B., Dorofeeva, V.A., Mironova, O.F.Principal physiochemical parameters of natural mineral forming fluids.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., p. 117-150.MantleMineral chemistry
DS201112-0549
2010
Dorofeeva, V.A.Kovalenko, V.I., Naumov, V.B., Girnis, A.V., Dorofeeva, V.A., Yarmolyuk, V.V.Average composition of basic magmas and mantle sources of island arcs and active continental margins estimated from the dat a on melt inclusions and quenched glassesVladykin, N.V., Deep Seated Magmatism: its sources and plumes, pp. 22-53.MantlePetrology
DS201112-0726
2011
Dorofeeva, V.A.Naumov, V.B., Kovanenko, V.I., Dorofeeva, V.A., Girnis, A.V., Yarmolyuk,V.V.Average compositions of igneous melts from main geodynamic settings according to the investigation of melt inclusions in minerals& quenched glasses of rocks.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., pp. 171-204.MantleMelt inclusion database
DS201312-0865
2013
Dorogokupets, P.I.Sokolova, T.S., Dorogokupets, P.I., Litasov, K.D.Self consistent pressure scales based on the equations of state for ruby, diamond, MgO, B2-NaCl, as well as Au, Pt and other metals to 4 Mbar and 3000K.Russian Geology and Geophysics, Vol. 54, pp. 181-199.MantleMelting
DS201502-0055
2015
Dorogokupets, P.I.Dorogokupets, P.I., Dymshits, A.M., Sokolova, T.S., Danilov, B.S., Litasov, K.D.The equations of state of forsterite, wadsleyite, ringwoodite, akimotoite, Mg2SiO4 perovskite and post perovskite and phase diagram for the Mg2SiO4 system at pressures of up to 130 Gpa.Russian Geology and Geophysics, Vol. 56, 1-2, pp. 172-189.TechnologyPerovskite
DS201805-0978
2016
Dorogokupets, P.I.Sokolova, T.S., Dorogokupets, P.I., Dymshits, A.M., Danilov, B.S., Konstantin, D.Microsoft excel spreadsheet for calculations of P-V-T relations and thermodynamic properties from equations of state of MgO, diamond and nine other metals as pressure markers in high-pressure and high-temperature experiments.Computers & Geosciences, Vol. 94, 1, pp. 162-169.TechnologyUHP

Abstract: We present Microsoft Excel spreadsheets for calculation of thermodynamic functions and P-V-T properties of MgO, diamond and 9 metals, Al, Cu, Ag, Au, Pt, Nb, Ta, Mo, and W, depending on temperature and volume or temperature and pressure. The spreadsheets include the most common pressure markers used in in situ experiments with diamond anvil cell and multianvil techniques. The calculations are based on the equation of state formalism via the Helmholtz free energy. The program was developed using Visual Basic for Applications in Microsoft Excel and is a time-efficient tool to evaluate volume, pressure and other thermodynamic functions using T-P and T-V data only as input parameters. This application is aimed to solve practical issues of high pressure experiments in geosciences and mineral physics.
DS200612-1106
2006
Dorokhova, G.I.Posukhova, T.V., Malakhova, F., Dorokhova, G.I.X ray computer microtomography - effective method of the investigation of the inclusion in diamond.International Mineralogical Association 19th. General Meeting, held Kobe, Japan July 23-28 2006, Abstract p.TechnologyDiamond inclusions
DS1996-0379
1996
Doronina, N.A.Doronina, N.A., Sklyarov, Ye.V.Relationship of eclogite and granulite metamorphism within the South MuyaBlock.Doklady Academy of Sciences, Vol. 344 No. 7, August pp. 105-110.Russia, ChinaKokchetav block, Eclogites
DS201212-0168
2012
Doronzo, D.M.Doronzo, D.M., Mart, J., Sulpizio, R., Dellino, P.Aerodynamics of stratovolcanoes during multiphase processes.Journal of Geophysical Research,, Vol. 117, B1, B01207.MantleVolcanoes
DS1991-0172
1991
Doroshev, A.Brey, G.P., Doroshev, A., Kogarko, L.The join pyrope knorringite-experimental constraints for a new geothermo barometer for coexisting garnet and spinelProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 26-28GlobalMineralogy
DS1983-0430
1983
Doroshev, A.M.Malinovskii, I.I., Doroshev, A.M., Kalinin, A.A.Investigation of the Stability of Pyrope-grossular Garnets Under the Pressure of 30kbar.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 268, No. 1, PP. 163-168.RussiaBlank
DS1986-0043
1986
Doroshev, A.M.Bakumento, I.T., Dolgov, Yu.A., Doroshev, A.M., et al.Physicochemical formation conditions and features of The composition of rocks of the crust and upper mantleSoviet Geology and Geophysics, Vol. 27, No. 1, pp. 81-88RussiaDiamond, Genesis
DS1989-0052
1989
Doroshev, A.M.Babich, Yu.V., Doroshev, A.M., Malinovskii, I.Yu.Heat-activated transformation of coesite at standard pressureSoviet Geology and Geophysics, Vol. 30, No. 2, pp. 140-146RussiaCoesite, Mineralogy
DS1990-0419
1990
Doroshev, A.M.Doroshev, A.M., Galkin, V.M., Turkin, A.I., Kalinin, A.A.Thermal expansion of garnets of pyrope grossularite and pyrope Knorringiteseries.(Russian)Geochemistry International (Geokhimiya), (Russian), No. 1, January 1990, pp. 152-155RussiaGarnet-pyrope, Geochemistry
DS1990-0420
1990
Doroshev, A.M.Doroshev, A.M., Galkin, V.M., Turkin, A.I., Kalinin, A.A.Thermal expansion in the pyrope-grossular and pyrope-knorringite garnetseriesGeochemistry International, Vol. 27, No. 8, pp. 144-149RussiaMineralogy, Pyrope
DS1992-0382
1992
Doroshev, A.M.Doroshev, A.M., et al.Experimental evidence of high pressure origin of the potassium bearingclinopyroxenesProceedings of the 29th International Geological Congress. Held Japan August 1992, Vol. 2, abstract p. 602RussiaExperimental petrology, Clinopyroxenes
DS1995-0434
1995
Doroshev, A.M.Doroshev, A.M., Palyanov, Yu.N., Turkin, A.I., et al.Experimental investigation of joint crystallization of diamond with minerals of eclogites and peridotites.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 135-7.Russia, YakutiaDiamond morphology, genesis, Deposit -Mir
DS1997-0285
1997
Doroshev, A.M.Doroshev, A.M., Brey, G.P., Girnis, A.V., Turkin, A.I.Pyrope - knorringite garnets in the Earth's mantle: experimental in the MgOAl2O3 SiO2 Cr2O3 systemRussian Geology and Geophysics, Vol. 38, No. 2, pp. 559-586.MantleGarnets, Petrochemistry
DS1998-1490
1998
Doroshev, A.M.Turkin, A.I., Ashchepkov, I.V., Doroshev, A.M.Experimental simulation of the garnet to spinel lherzolite transition in anatural systemRussian Geol. Geophys., Vol. 38, No. 7, pp. 1199-1209.GlobalPetrology - experimental, Garnet
DS200712-0268
2007
Doroshkevich, A.Doroshkevich, A., Wall, F., Ripp, G.Magmatic graphite in dolomite carbonatite at Pogranichnoe North Transbaikalia, Russia.Contributions to Mineralogy and Petrology, Vol. 153, 3, pp. 339-353.RussiaCarbonatite
DS201312-0225
2013
Doroshkevich, A.Doroshkevich, A., Ripp, G., Vladykin, N., Savatenkov, V.Sources of the Late Riphean carbonatite magmatism of northern Transbaikalia.Geochemistry International, Vol. 49, 12, pp. 1195-1207.RussiaCarbonatite
DS202008-1436
2020
Doroshkevich, A.Prokopyev, I.R., Kozlov, E., Fomina,E., Doroshkevich, A.Mineralogy and fluid regime of formation of the REE-Late-Stage hydrothermal mineralization of Petyayan-Vara carbonatites ( Vuoriyarvi, Kola region, NW Russia.Minerals, 19p. PdfRussia, Kola Peninsulacarbonatite

Abstract: The Vuoriyarvi Devonian alkaline-ultramafic complex (northwest Russia) contains magnesiocarbonatites with rare earth mineralization localized in the Petyayan-Vara area. High concentrations of rare earth elements are found in two types of these rocks: (a) ancylite-dominant magnesiocarbonatites with ancylite-baryte-strontianite-calcite-quartz (±late Ca-Fe-Mg carbonates) ore assemblage, i.e., “ancylite ores”; (b) breccias of magnesiocarbonatites with a quartz-bastnäsite matrix (±late Ca-Fe-Mg carbonates), i.e., “bastnäsite ores.” We studied fluid inclusions in quartz and late-stage Ca-Fe-Mg carbonates from these ore assemblages. Fluid inclusion data show that ore-related mineralization was formed in several stages. We propose the following TX evolution scheme for ore-related processes: (1) the formation of ancylite ores began under the influence of highly concentrated (>50 wt.%) sulphate fluids (with thenardite and anhydrite predominant in the daughter phases of inclusions) at a temperature above300-350 °C; (2) the completion of the formation of ancylite ores and their auto-metasomatic alteration occurred under the influence of concentrated (40-45 wt.%) carbonate fluids (shortite and synchysite-Ce in fluid inclusions) at a temperature above 250-275 °C; (3) bastnäsite ores deposited from low-concentrated (20-30 wt.%) hydrocarbonate-chloride fluids (halite, nahcolite, and/or gaylussite in fluid inclusions) at a temperature of 190-250 °C or higher. Later hydrothermal mineralization was related to the low-concentration hydrocarbonate-chloride fluids (<15 wt.% NaCl-equ.) at 150-200 °C. The presented data show the specific features of the mineral and fluid evolution of ore-related late-stage hydrothermal rare earth element (REE) mineralization of the Vuoriyarvi alkaline-ultramafic complex.
DS2002-0392
2002
Doroshkevich, A.G.Doroshkevich, A.G., Kobylkina, O.V., Ripp, G.S.Role of sulfates in the formation of carbonatites in the western Transbaikal regionDoklady Earth Sciences, Vol. 387A,9, pp. 131-4.RussiaCarbonatite
DS200512-0244
2004
Doroshkevich, A.G.Doroshkevich, A.G., Ripp, G.S.Estimation of the conditions of formations of REE carbonatites in western Transbaikalia.Russian Geology and Geophysics, Vol. 45, 4, pp. 456-463.RussiaCarbonatite, rare earths
DS200512-0904
2004
Doroshkevich, A.G.Ripp, G.S., Badmatsyrenov, M.V., Doroshkevich, A.G., Isbrodin, L.A.Mineral composition and geochemical characteristic of the Veseloe carbonatites ( Northern Transbaikalia, Russia).Deep seated magmatism, its sources and their relation to plume processes., pp. 257-272.RussiaCarbonatite, mineralogy
DS200612-0771
2006
Doroshkevich, A.G.Lastochkin, E.I., Ripp, G.S., Doroshkevich, A.G., Badmatsirenov, M.V.Metamorphism of the Vesloe carbonatites, north Transbaikalia, Russia.Vladykin: VI International Workshop, held Mirny, Deep seated magmatism, its sources and plumes, pp. 207-RussiaCarbonatite
DS200612-1162
2005
Doroshkevich, A.G.Ripp, G.S., Badmatsyrenov, M.V., Doroshkevich, A.G., Izbrodin, I.A.New carbonatite bearing area in northern Transbaikalia. Muya and Pogranichnoe.Petrology, Vol. 13, 5, pp. 489-498.RussiaCarbonatite, metasomatism
DS200612-1163
2006
Doroshkevich, A.G.Ripp, G.S., Karmanov, N.S., Doroshkevich, A.G., Badmatsyrenov, M.V., Izbrodin, I.A.Chrome bearing mineral phases in the carbonatites of northern Transbaikalia.Geochemistry International, Vol. 44, 4, pp. 395-402.RussiaCarbonatite
DS200712-0269
2007
Doroshkevich, A.G.Doroshkevich, A.G., Wall, A.G., Ripp, G.S.Magmatic graphite in dolomite carbonatite at Pogranichnoe, North Transbaikalia, Russia.Contributions to Mineralogy and Petrology, Vol. 153, 3, pp. 339-353.RussiaCarbonatite
DS200712-0270
2007
Doroshkevich, A.G.Doroshkevich, A.G., Wall, F., Ripp, G.S.Calcite bearing dolomite carbonatite dykes from Veseloe, north Transbaikala, Russia, and possible Cr rich mantle xenoliths.Mineralogy and Petrology, Vol. 90, 1-2, pp. 19-49.RussiaCarbonatite
DS200712-0271
2007
Doroshkevich, A.G.Doroshkevich, A.G., Wall, F., Ripp, G.S.Calcite bearing dolomite carbonatite dykes from Veseloe, North Transbaikalia, Russia and possible Cr rich mantle xenoliths.Mineralogy and Petrology, Vol. 90, 1-2, pp. 19-49.RussiaCarbonatite
DS200812-0295
2008
Doroshkevich, A.G.Doroshkevich, A.G., Ripp, G.S., Viladkar, S.G., Vladykin, N.V.The Arshan REE carbonatites, southwestern Transbaiklia, Russia: mineralogy, parageneis, and evolution.Canadian Mineralogist, Vol. 46, 4, August pp.RussiaCarbonatite
DS200912-0184
2009
Doroshkevich, A.G.Doroshkevich, A.G., Ripp, G., Viladkar, S.Newania carbonatites, western India: example of mantle derived magnesium carbonatites.Mineralogy and Petrology, in press availableIndiaCarbonatite
DS201012-0165
2010
Doroshkevich, A.G.Doroshkevich, A.G., Ripp, G., Vladkar, S.Newania carbonatites, western India:example of mantle derived magnesium carbonatites.Mineralogy and Petrology, Vol. 98, 1-4, pp. 283-295.IndiaCarbonatite
DS201012-0166
2009
Doroshkevich, A.G.Doroshkevich, A.G., Ripp, G.S.Isotopic systematics of the rocks of the Khalyuta carbonatite complex of western Transbaikalia.Geochemistry International, Vol. 47, 12, pp. 1198-1211.RussiaGeochronology
DS201012-0167
2010
Doroshkevich, A.G.Doroshkevich, A.G., Ripp, G.S., Moore, K.R.Genesis of the Khaluta alkaline basic Ba Sr carbonatite complex (West Transbaikala) Russia.Mineralogy and Petrology, Vol. 98, 1-4, pp. 245-268.RussiaCarbonatite
DS201012-0168
2009
Doroshkevich, A.G.Doroshkevich, A.G., Viladar, S.G., Ripp, G.S., Burtseva, M.V.Hydrothermal REE mineralization in the Amba Dongar carbonatite complex, Gujarat, India.Canadian Mineralogist, Vol. 47, 5, pp. 1105-1116.IndiaCarbonatite
DS201112-0284
2011
Doroshkevich, A.G.Doroshkevich, A.G., Ripp, G.S., Savatenkov, V.M.Alkaline magmatism of Vitim province, West Transbaikalia, Russia: age, mineralogical, geochemical and isotope (O, C,D, Sr, Nd) data.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterRussiaMagmatism
DS201112-0869
2011
Doroshkevich, A.G.Ripp, G.S., Doroshkevich, A.G.A way of carbonatite formation from alkaline gabbros, Oshurkovo Massif (Transbaikalia, Russia).Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterRussiaCarbonatite
DS201212-0169
2012
Doroshkevich, A.G.Doroshkevich, A.G., Ripp, G.S., Izbrodin, I.A., Savatenkov, V.M.Alkaline magmatism of the Vitim province, west Transbaikalia, Russia: age, mineralogical, geochemical and isotope (O,C,D,Sr and Nd) data.Lithos, Vol. 152, pp. 157-172.RussiaMagmatism
DS201312-0114
2013
Doroshkevich, A.G.Burtseva, M.V., Ripp, G.S., Doroshkevich, A.G., Viladkar, S.G., Varadan, R.Features of mineral and chemical composition of the Khamambettu carbonatites, Tamil, Nadu.Journal of the Geological Society of India, Vol. 81, 5, pp. 655-664.IndiaCarbonatite
DS201412-0203
2014
Doroshkevich, A.G.Doroshkevich, A.G., Ripp, G.S., Izbrodin, I.A., Sergeev, S.A., Travin, A.V.Geochronology of the Gulkhen Massif, Vitim alkali province, western Transbaikalia.Doklady Earth Sciences, Vol. 457, 2, pp. 940-944.RussiaAlkalic
DS201710-2258
2017
Doroshkevich, A.G.Prokopyev, I.R., Doroshkevich, A.G., Redina, A.A.Magnetite apatite dolomitic rocks of Ust-Chulman ( Aldan Shield, Russia): Seligdar type carbonatites?Mineralogy and Petrology, in press available 10p.Russiacarbonatite

Abstract: The Ust-Chulman apatite ore body is situated within the Nimnyrskaya apatite zone at the Aldan shield in Russia. The latest data confirm the carbonatitic origin of the Seligdar apatite deposit (Prokopyev et al. in Ore Geol Rev 81:296-308, 2017). The results of our investigations demonstrate that the magnetite-apatite-dolomitic rocks of the Ust-Chulman are highly similar to Seligdar-type dolomitic carbonatites in terms of the mineralogy and the fluid regime of formation. The ilmenite and spinel mineral phases occur as solid solutions with magnetite, and support the magmatic origin of the Ust-Chulman ores. The chemical composition of REE- and SO3-bearing apatite crystals and, specifically, monazite-(Ce) mineralisation and the formation of Nb-rutile, late hydrothermal sulphate minerals (barite, anhydrite) and haematite are typical for carbonatite complexes. The fluid inclusions study revealed similarities to the evolutionary trend of the Seligdar carbonatites that included changes of the hydrothermal solutions from highly concentrated chloride to medium-low concentrated chloride-sulphate and oxidized carbonate-ferrous.
DS201712-2678
2017
Doroshkevich, A.G.Chebotarev, D.A., Doroshkevich, A.G., Sharygin, V.V., Yudin, D.S., Ponomarchuk, A.V., Sergeev, S.A.Geochronology of the Chuktukon carbonatite massif, Chadobets uplift ( Krasnoyarsk Territory).Russian Geology and Geophysics, Vol. 58, pp. 1222-1231.Russiacarbonatite

Abstract: We present results of U-Pb (SHRIMP II) and Ar-Ar geochronological study of the rocks of the Chuktukon massif, which is part of the Chadobets alkaline-carbonatite complex, and of the weathering crust developed after them. Perovskite from picrites and monazite from the weathering crust were dated by the U-Pb (SHRIMP II) method, and rippite from carbonatites, by the Ar-Ar method. Rippite has first been used as a geochronometer. The estimated ages (252 ± 12 and 231 ± 2.7 Ma) testify to two magmatism pulses close in time (within the estimation error) to the stages of alkaline magmatism in the Siberian Platform (250-245 and 238-234 Ma). These pulses characterize, most likely, the processes accompanying and completing the activity of the mantle superplume that formed the Siberian Igneous Province at 250-248 Ma. The monazite-estimated age (102.6 ± 2.9 Ma) reflects the time of formation of the ore-bearing weathering crust on the massif rocks.
DS201801-0059
2017
Doroshkevich, A.G.Sharygin, V.V., Doroshkevich, A.G.Mineralogy of secondary olivine hosted inclusions in calcite carbonatiites of the Belaya Zima alkaline complex, eastern Sayan Russia: evidence for late magmatic Na-Ca-rich carbonate composition.Journal of the Geological Society of India, Vol. 90, 5, pp. 524-530.Russiacarbonatite

Abstract: Secondary multiphase inclusions were studied in olivine from olivine-pyrochlore varieties of calcite carbonatites of the Belaya Zima alkaline complex, Eastern Sayan, Siberia, Russia. The inclusions form trails cross-cutting the host olivine. Their composition varies from carbonate to silicate-carbonate species. Multiphase silicate-carbonate inclusions contain Na-Ca-carbonates (shortite, nyerereite), Na-Mg-carbonates (northupite, eitelite, bradleyite), common carbonates (calcite, dolomite), Ba-Sr-rich carbonates (olekminskite, burbankite, strontianite), tetraferriphlogopite, magnetite, humite-clinohumite and other mineral phases. Na-Ca-carbonates, tetraferriphlogopite, humiteclinohumite and magnetite are omnipresent and dominant phases within the inclusions. The phase composition of secondary olivinehosted inclusions seems to reflect evolutionary features for the Belaya Zima carbonatites at their late stages of formation. During crystallization calciocarbonatite melt gradually evolved toward enrichment in alkalis (mainly, in sodium) and volatile components (Cl, F and H2O).
DS201802-0260
2018
Doroshkevich, A.G.Prokopyev, I.R., Doroshkevich, A.G., Redina, A.A., Obukhov, A.V.Magnetite apatite dolomitic rocks of Ust Chulman ( Aldan Shield, Russia): Seligdar type carbonatites?Mineralogy and Petrology, in press available, 10p.Russia, Aldan shieldcarbonatites

Abstract: The Ust-Chulman apatite ore body is situated within the Nimnyrskaya apatite zone at the Aldan shield in Russia. The latest data confirm the carbonatitic origin of the Seligdar apatite deposit (Prokopyev et al. in Ore Geol Rev 81:296-308, 2017). The results of our investigations demonstrate that the magnetite-apatite-dolomitic rocks of the Ust-Chulman are highly similar to Seligdar-type dolomitic carbonatites in terms of the mineralogy and the fluid regime of formation. The ilmenite and spinel mineral phases occur as solid solutions with magnetite, and support the magmatic origin of the Ust-Chulman ores. The chemical composition of REE- and SO3-bearing apatite crystals and, specifically, monazite-(Ce) mineralisation and the formation of Nb-rutile, late hydrothermal sulphate minerals (barite, anhydrite) and haematite are typical for carbonatite complexes. The fluid inclusions study revealed similarities to the evolutionary trend of the Seligdar carbonatites that included changes of the hydrothermal solutions from highly concentrated chloride to medium-low concentrated chloride-sulphate and oxidized carbonate-ferrous.
DS201901-0016
2019
Doroshkevich, A.G.Chebotarev, D.A., Veksler, I.V., Wohlgemuth-Uberwasser, C., Doroshkevich, A.G., Koch-Muller, M.Experimental study of trace element distribution between calcite, fluorite and carbonatitic melt in the systemCaCO3+CaF2+Na2CO3+-Ca3(P04)2 at 100MPa.Contributions to Mineralogy and Petrology, Vol. 174, 4, doi.org/10. 1007/s00410-018-1530-x 13p.Mantlecarbonatite

Abstract: Here we present an experimental study of the distribution of a broad range of trace elements between carbonatite melt, calcite and fluorite. The experiments were performed in the CaCO3 + CaF2 + Na2CO3 ± Ca3(PO4)2 synthetic system at 650-900 °C and 100 MPa using rapid-quench cold-seal pressure vessels. Starting mixtures were composed of reagent-grade oxides, carbonates, Ca3(PO4)2 and CaF2 doped with 1 wt% REE-HFSE mixture. The results show that the distribution coefficients of all the analyzed trace elements for calcite and fluorite are below 1, with the highest values observed for Sr (0.48-0.8 for calcite and 0.14-0.3 for fluorite) and Y (0.18-0.3). The partition coefficients of REE gradually increase with increasing atomic number from La to Lu. The solubility of Zr, Hf, Nb and Ta in the synthetic F-rich carbonatitic melts, which were used in our experiments, is low and limited by crystallization of baddeleyite and Nb-bearing perovskite.
DS201905-1024
2019
Doroshkevich, A.G.Doroshkevich, A.G., Chebotarev, D.A., Sharygin, V.V.. Prokopyev, I.R., Nikolenko, A.M.Petrology of alkaline silicate rocks and carbonatites of the Chuktukon massif, Chadobets upland, Russia: sources, evolution and relation to the Triassic Siberian LIP.Lithos, Vol. 332-333, pp. 245-260.Russiacarbonatite

Abstract: The petrogenesis of temporally and spatially associated carbonatitic and deeply derived carbonated alkaline silicate magmas provides an opportunity to gain insights into the nature of the deepest lithospheric mantle. The Chuktukon massif, which is part of the Chadobets alkaline ultramafic carbonatite complex (Chadobets upland, Siberian craton) is a carbonatite-melilitite-damtjernite intrusion, whose emplacement was coeval with the Siberian Traps large igneous province (LIP). In this study, the sources of the primary melts are examined, the petrogenetic evolution of the complex is reconstructed and the relationship with the Siberian LIP is also discussed. Isotopic and geochemical information indicate that the source for the Chuktukon primary melts was isotopically moderately depleted and the primarymelts were formed by lowdegree partial melting of garnet carbonated peridotite. Hydrothermal processes caused 18O- and 13C- enrichment. The weathering process was accompanied by trace element re-distribution and enrichment of the weathering crust in Zn, Th, U, Nb, Pb and REE, relative to the Chuktukon rocks and a change in radiogenic (Sr, Nd) isotope compositions.
DS201905-1068
2019
Doroshkevich, A.G.Prokopyev, I.R., Doroshkevich, A.G., Sergeev, S.A., Ernst, R.E., Ponomarev, J.D., Redina, A.A., Chebotarev, D.A., Nikolenko, A.M., Dultsev, V.F., Moroz, T.N., Minakov, A.V.Petrography, mineralogy and SIMS U-Pb geochronology of 1.0 - 1.8 Ga carbonatites and associated alkaline rocks of the Central Aldan magnesiocarbonatite province ( South Yakutia, Russia).Mineralogy and Petrology, Doi.org/a0.1007/ s00710-019-00661-3 24p.Russiacarbonatites
DS201906-1289
2019
Doroshkevich, A.G.Doroshkevich, A.G., Chebotarev, D.A., Sharygin, V.V., Prokopyev, I.R., Nikolenko, A.M.Petrology of alkaline silicate rocks and carbonatites of the Chuktukon massif, Chadobets upland, Russia: sources, evolution and relation to the Triassic Siberian LIP.Lithos, Vol. 332-333, pp. 245-260.Russiacarbonatites

Abstract: The petrogenesis of temporally and spatially associated carbonatitic and deeply derived carbonated alkaline silicate magmas provides an opportunity to gain insights into the nature of the deepest lithospheric mantle. The Chuktukon massif, which is part of the Chadobets alkaline ultramafic carbonatite complex (Chadobets upland, Siberian craton) is a carbonatite-melilitite-damtjernite intrusion, whose emplacement was coeval with the Siberian Traps large igneous province (LIP). In this study, the sources of the primary melts are examined, the petrogenetic evolution of the complex is reconstructed and the relationship with the Siberian LIP is also discussed. Isotopic and geochemical information indicate that the source for the Chuktukon primary melts was isotopically moderately depleted and the primary melts were formed by low degree partial melting of garnet carbonated peridotite. Hydrothermal processes caused 18 O- and 13 C- enrichment. The weathering process was accompanied by trace element re-distribution and enrichment of the weathering crust in Zn, Th, U, Nb, Pb and REE, relative to the Chuktukon rocks and a change in radiogenic (Sr, Nd) isotope compositions.
DS201906-1339
2019
Doroshkevich, A.G.Prokopyev, I.R., Doroshkevich, A.G., Sergeev, S.A., Ernst, R.E., Ponomarev, J.D., Redina, A.A., Chebotarev, D.A., Nikolenko, A.M., Dultsev, V.F., Moroz, T.N., Minakov, A.V.Petrography, mineralogy and SIMS U-Pb geochronology of 1.9-1.8 Ha carbonatites and associated alkaline rocks of the Central-Aldan magnesiocarbonatite province ( South Yakutia, Russia).Mineralogy and Petrology, Vol. 113, pp. 329-352.Russia, Yakutiacarbonatites
DS202008-1426
2020
Doroshkevich, A.G.Nikolenko, A.M., Doroshkevich, A.G., Ponomarchuk, A.V., Redina, A.A., Prokopyev, I.R., Vladykin, N.V., Nikolaeva, I.V.Ar-Ar geochronology and petrogenesis of the Mushgai-Khudag alkaline-carbonatite complex 9 southern Mongolia).Lithos, Vol. 372-372, 105675 15p. PdfAsia, Mongoliacarbonatite

Abstract: The Mushgai-Khudag alkaline-carbonatite complex, located in southern Mongolia within the Central Asian Orogenic Belt (CAOB), comprises a broad range of volcanic and subvolcanic alkaline silicate rocks (melanephelinite-trachyte and shonkinite-alkaline syenite, respectively). Magnetite-apatite rocks, carbonatites, and fluorite mineralization are also manifested in this area. The complex formed between 145 and 133 Ma and is contemporaneous with late Mesozoic alkaline-carbonatite magmatism within the CAOB. Major and trace element characteristics of silicate rocks in the Mushgai-Khudag complex imply that these rocks were formed by the fractional crystallization of alkaline ultramafic parental magma. Magnetite-apatite rocks may be a product of silicate-Ca-Fe-P liquid immiscibility that took place during the alkaline syenite crystallization stage. The Mushgai-Khudag rocks have variable and moderately radiogenic Sr (87Sr/86Sr(i) = 0.70532-0.70614), ?Nd(t) = -1.23 to 1.25) isotopic compositions. LILE/HFSE values and SrNd isotope compositions indicate that the parental melts of Mushgai-Khudag were derived from a lithospheric mantle source that was affected by a metasomatic agent in the form a mixture of subducted oceanic crust and its sedimentary components. The d18OSMOW and d18CPDB values for calcites in carbonatites range from 16.8‰ to 19.2‰ and from -3.9‰ to 2.0‰, respectively. CO covariations in calcites of the Mushgai-Khudag carbonatites can be explained by the slight host limestone assimilation.
DS201803-0443
2018
Doroshkevich< A.G.Doroshkevich< A.G., Prokopyev, I.R., Izokh, A.E., Klemd, R., Ponomarchuk, A.V., Nikolaeva, I.V., Vladykin, N.V.Isotopic and trace element geochemistry of the Seligdar magnesiocarbonatites ( South Yakutia, Russia): insights regarding the mantle evolution beneath the Aldan Stanovoy shield.Journal of Asian Earth Sciences, Vol. 154, pp. 354-368.Russia, Yakutiacarbonatite -Seligdar

Abstract: The Paleoproterozoic Seligdar magnesiocarbonatite intrusion of the Aldan-Stanovoy shield in Russia underwent extensive postmagmatic hydrothermal alteration and metamorphic events. This study comprises new isotopic (Sr, Nd, C and O) data, whole-rock major and trace element compositions and trace element characteristics of the major minerals to gain a better understanding of the source and the formation process of the carbonatites. The Seligdar carbonatites have high concentrations of P2O5 (up to 18?wt%) and low concentrations of Na, K, Sr and Ba. The chondrite-normalized REE patterns of these carbonatites display significant enrichments of LREE relative to HREE with an average La/Ybcn ratio of 95. Hydrothermal and metamorphic overprints changed the trace element characteristics of the carbonatites and their minerals. These alteration processes were responsible for Sr loss and the shifting of the Sr isotopic compositions towards more radiogenic values. The altered carbonatites are further characterized by distinct 18O- and 13C-enrichments compared to the primary igneous carbonatites. The alteration most likely resulted from both the percolation of crustal-derived hydrothermal fluids and subsequent metamorphic processes accompanied by interaction with limestone-derived CO2. The narrow range of negative eNd(T) values indicates that the Seligdar carbonatites are dominated by a homogenous enriched mantle source component that was separated from the depleted mantle during the Archean.
DS200912-0628
2009
Doroshkevick, A.G.Ripp, G.S., Doroshkevick, A.G., Posokhov, V.F.Age of carbonatite magmatism in Transbaikalia.Petrology, Vol. 17, 1, pp. 73-89.RussiaCarbonatite
DS2000-0971
2000
DorrValverde-Vaquero, P., Dorr, Belka, Franke, WiszniewskaUranium-lead (U-Pb) single grain dating of detrital zircon in the Cambrian of central Poland: implications for GondwanaEarth and Planetary Science Letters, Vol. 184, No.1, Dec.30, pp. 225-40.GlobalTectonics - Baltica, Trans European Suture Zone - not specific to diamonds
DS2001-0143
2001
Dorr, W.Buhn, B., Dorr, W., Brauns, C.M.Petrology and age of Otjisazu carbonatite complex: implications pre- and syJournal of African Earth Sciences, Vol. 32, No. 1, Jan. pp. 1-18.NamibiaCarbonatite
DS200412-1998
2004
Dorr, W.Timmermann, H., Stedra, V., Gerdes, A., Noble, S.R., Parrish, R.R., Dorr, W.The problem of dating high pressure metamorphism: a U Pb isotope and geochemical study on eclogites and related rocks of the MarJournal of Petrology, Vol. 45, 7, pp. 1311-1338.Europe, Czech RepublicEclogite, UHP
DS1997-0286
1997
Dorre, A.S.Dorre, A.S., et al.Crustal thickness of Egypt determined by gravity dataJournal of African Earth Sciences, Vol. 25, No. 3, Oct. pp. 425-34EgyptGeophysics - gravity
DS1993-0370
1993
Dort, W.Jr.Dort, W.Jr., Zeller, E.J.Extensive late-Quaternary faulting in the Mid-continent Great PlainsGeological Society of America Annual Abstract Volume, Vol. 25, No. 6, p. A70 abstract onlyNebraskaTectonics, Structure -faults
DS201112-0383
2010
Dos Reis Neto, J.M.Gouveau Vasconcellos, E.M., Dos Reis Neto, J.M.Caracterizacao morfologica de cristais de diamante do Rio Tibagi, municipio de Telemaco Borba, Parana.5th Brasilian Symposium on Diamond Geology, Nov. 6-12, abstract p. 34-35.South America, Brazil, ParanaDiamond morphology
DS202002-0186
2020
dos Santis Alvarenga, R.Garcia, L.F., Abel, M., Perrin, M., dos Santis Alvarenga, R.The GeoCore ontology: a core ontology for general use in geology.Computers and Geosciences, Vol. 135, 104387 9p. PdfGlobalGeoCore

Abstract: Domain ontologies assume the role of representing, in a formal way, a consensual knowledge of a community over a domain. This task is especially difficult in a wide domain like Geology, which is composed of diversified science resting on a large variety of conceptual models that were developed over time. The meaning of the concepts used by the various professionals often depends on the particular vision that they have of a domain according to their background and working habits. Ontology development in Geology thus necessitates a drastic elucidation of the concepts and vocabulary used by geologists. This article intends to contribute to solving these difficulties by proposing a core ontology named GeoCore Ontology resting on the BFO top ontology, specially designed for describing scientific fields. GeoCore Ontology contains well-founded definitions of a limited set of general concepts within the Geology field that are currently considered by all geologists whatever their skill. It allows modelers to separately consider a geological object, the substance that constitutes it, the boundaries that limit it and the internal arrangement of the matter inside it. The core ontology also allows the description of the existentially dependent qualities attached to a geological object and the geological process that generated it in a particular geological age. This small set of formally defined and described concepts combined with concepts from BFO provides a backbone for deriving by subsumption more specialized geological concepts and also constitutes a baseline for integrating different existent domain ontologies within the Geology domain. The GeoCore ontology and the methodology that we used for building it, provide solutions for unveiling major misunderstanding regarding the concepts that are commonly used for formulating geological interpretations. This will facilitate the communication of this information to external Geology users and its integration in domain applications.
DS1991-0479
1991
Dos Santos, A.B.R.M.Filho, A.I., Dos Santos, A.B.R.M., Riffel, B.F., Lapido-LoureiroAspects of the geology, petrology and chemistry of Angolan carbonatitesJournal of Geochemical Exploration, Special Publications Geochemical Exploration, Vol. 40, No. 1-3, pp. 205-226AngolaCarbonatite, Petrology
DS201412-0127
2014
Dos Santos, A.M.Chheda, T.D., Mookherjee, M., Mainprice, D., Dos Santos, A.M., Molaison, J.J., Chantel, J., Manthilake, G., Bassett, W.A.Structure and elasticity of phlogopite under compression: geophysical implications.Physics of the Earth and Planetary Interiors, Vol. 233, pp. 1-12.MantleGeophysics
DS201906-1301
2019
dos Santos, E.Higgins, M., Bedard, L.P., dos Santos, E., Vander Auwera, J.Lamprophyres, carbonatites and phoscorites of the Saguenay City alkali province, Quebec, CanadaGAC/MAC annual Meeting, 1p. Abstract p. 108.Canada, QuebecCcrbonatite

Abstract: The Saguenay City alkali province (~ 580 Ma) comprises the Saint-Honoré alkaline complex (carbonatite-syenite), lesser-known minor subsurface carbonatite intrusions and several sets of lamprophyre (sl) dykes. Flat-lying, north-dipping dykes (l-100 cm) that crop out close the Saguenay River/Fjord were formed by multiple intrusions of a very fluid magma. The dykes are continuously variable in composition from carbonatite to ultramafic lamprophyre. Olivine phenocrysts (l-3 mm) are pseudomorphed by serpentine but phlogopite phenocrysts (l-5 mm) are well preserved in a matrix of a fine-grained serpentine, chlorite and carbonate. A few dykes are phoscorites, with abundant phenocrysts of phlogopite, oxides, apatite and accessory baddeleyite. In all dykes, the matrix may have been originally fine-grained or even glassy, and subsequently altered by water dissolved in the original magma. Several dykes contain abundant xenoliths: mostly crustal and possibly one of mantle origin. Low-carbonate dykes have a narrow range in Sr isotopes (0.7030-0.7033) versus the wider range of high-carbonate dykes (0.7032-0.7046), but this distinction is not seen in eNd (3.4-4.9). Overall, it appears that each batch of magma was small and came from independent mantle sources. Recently, we found a new set of vertical, NW-directed lamprophyres around the Baie des Ha! Ha!, about 15 km south of the main swarm. They have phlogopite phenocrysts to 50 mm and olivine pseudomorphs. Their contrasting orientation suggests that they have a different age to the Saguenay River dykes, but they have yet to be dated. The overall pattern is of an extensive mantle source that delivered small volumes of volatile-rich ultramafic magmas over a long period. We consider that some of these magma batches accumulated and differentiated in a magma chamber beneath the Saint-Honoré alkaline complex, whereas others rose uninterrupted to high levels of the crust where they were emplaced as dykes.
DS201507-0323
2016
dos Santos, R.P.Z.Mantovani, M.S.M., Louro, V.H.A., Ribeiro, V.B., Requejo, H.S., dos Santos, R.P.Z.Geophysical analysis of Catalao 1 alkaline carbonatite complex in Goias, Brazil.Geophysical Prospecting, Vol. 64, pp. 216-227.South America, BrazilDeposit - Catalao
DS1994-0155
1994
Dos Santos Afonso, M.Biber, M.V., Dos Santos Afonso, M., Stumm, W.The coorindation chemistry of weathering: IV. Inhibition of the dissolution of oxide mineralsGeochimica et Cosmochimica Acta, Vol. 58, No. 9, May pp. 1999-2010GlobalGeochemistry, Laterites, weathering
DS1997-1150
1997
Doser, D.I.Tesha, A.L., Nyblade, A.A., Doser, D.I.Rift localization in suture thickened crust: evidence from bouguer gravity anomalies in northeast Tanzania.Tectonophysics, Vol. 278, No. 1-4, Sept. 15, pp. 315-328.Africa, east Africa, Tanzania, KenyaTectonics, Geophysics - gravity
DS2003-0142
2003
Dosseto, A.Bourdon, B., Turner, S., Dosseto, A.Dehydration and partial melting in subduction zones: constraints from U seriesJournal of Geophysical Research, Vol. 108, B6, 10.1029/2002JB001839 June 6MantleMelting, Subductioon
DS200412-0189
2003
Dosseto, A.Bourdon, B., Turner, S., Dosseto, A.Dehydration and partial melting in subduction zones: constraints from U series disequilibria.Journal of Geophysical Research, Vol. 108, B6, 10.1029/2002 JB001839 June 6MantleMelting, Subduction
DS201112-0285
2010
Dosseto, A.Dosseto, A., Turner, S., Van-Orman, J.Timescales of magmatic processes: from core to atmosphere.Wiley Blackwell, Paperback 978-1-444-33261-2 $ 100.00GlobalBook - advertisement
DS201112-0286
2010
Dosseto, A.Dosseto, A., Turner, S.P., Van Orman, J.A.editors.Timescales of magmatic processes: from core to atmosphere.Wiley Blackwell, 272p. $ 99.95MantleBook - geochronology, magmatism
DS1989-0556
1989
Dosso, L.Guerrot, C., Peucat, J.J., Capdevila, R., Dosso, L.Archean protoliths within early Proterozoic granulitic crust of the west European Hercynian belt: possible relics of the west African cratonGeology, Vol. 17, No. 3, March pp. 241-244West AfricaCraton, Proterozoic
DS2000-0242
2000
Dosso, L.Dosso, L., Bourgault, H., Vlastelic, I.Heterogeneity of the sub oceanic depleted mantleIgc 30th. Brasil, Aug. abstract only 1p.MantleTectonics
DS2002-1673
2002
Dosso, L.Vlastelic, I., Bougault, H., Dosso, L.Heterogeneous heat production in the Earth's upper mantle: blob melting and MORB composition.Earth and Planetary Science Letters, Vol.199,1-2,pp.157-72., Vol.199,1-2,pp.157-72.MantleMelting
DS2002-1674
2002
Dosso, L.Vlastelic, I., Bougault, H., Dosso, L.Heterogeneous heat production in the Earth's upper mantle: blob melting and MORB composition.Earth and Planetary Science Letters, Vol.199,1-2,pp.157-72., Vol.199,1-2,pp.157-72.MantleMelting
DS200412-1820
2004
Dosso, L.Silantyev, S.A., Bazylev, B.A., Dosso, L., Karpenko, S.F., Belyatskii, B.V.Relation between plume magmatism and mantle metasomatism beneath the Mid-Atlantic Ridge: petrological and geochemical evidence iPetrology, Vol.l2, 1, pp. 1-16.MantleMetasomatism
DS201412-0753
2014
Dosso, L.Rooney, T.O., Nelson, W.R., Dosso, L., Furman, T., Hanan, B.The role of continental lithosphere metasomes in the production of HIMU-like magmatism on the northeast African and Arabian plates, East African Rift zone.Geology, Vol. 42, pp. 419-422.AfricaMagmatism
DS1998-0783
1998
DostalKontak, D.J., Jensen, S.M., Dostal, ArchibaldPetrology of Late Cretaceous (CA 90 Ma) lamprophyric dykes from NorthGreenland.Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) Abstract Volume, p. A94. abstract.GreenlandDikes - lamprophyre, Petrography
DS2001-0622
2001
DostalKontak, D.J., Jensen, S.M., Dostal, Archibald, KyserCretaceous mafic dike swarm, Peary Land, northern most Greenland: geochronology and petrology.Canadian Mineralogist, Vol. 39, No. 4, Aug. pp. 997-1020.GreenlandLamprophyres, Mantle plume
DS1984-0240
1984
Dostal, J.Dostal, J., Boivan, P.A.Geochemistry and Petrology of Ultramafic Xenoliths and Their Host Basalts from Tallante, Southern Spain.Geological Association of Canada (GAC), Vol. 9, P. 58. (abstract.).SpainRelated Rocks, Lherzolite
DS1985-0151
1985
Dostal, J.Dostal, J., et al.Geochemistry of Precambrian baslatic rocks from the Central African republic ( Equatorial Africa).Canadian Journal of Earth Sciences, Vol. 22, pp. 653-62.Central African RepublicBasalts
DS1986-0191
1986
Dostal, J.Dostal, J., Baragarm W.R.A., Duput, C.Petrogenesis of the Natusiak continental basalts, Victoria Island, Northwest Territories.Canadian Journal of Earth Sciences, Vol. 23, pp. 622=32.Northwest Territories, Victoria IslandBasalts
DS1989-0367
1989
Dostal, J.Dostal, J., Jackson, G.D., Galley, A.Geochemistry of Neohelikian Nauyat plateau basalts, Borden rift basin, northwestern Baffin Island.Canadian Journal of Earth Sciences, Vol. 26, pp. 2214-23.Northwest Territories, Baffin IslandBasalts
DS1989-0933
1989
Dostal, J.Marcelot, G., Dupuy, C., Dostal, J., Rancan, J.P., Pouclet, A.Geochemistry of mafic volcanic rocks from the Lake Kivu (Zaire and Rwanda)section of the western branch Of the African riftJournal of Volcanology and Geothermal Research, Vol. 39, No. 1, October pp. 73-88Democratic Republic of CongoTectonics, Rifting
DS1990-0421
1990
Dostal, J.Dostal, J., McCutcheon, S.R.Geochemistry of Late Proterozoic basaltic rocks from southeastern NewBrunswick, CanadaPrecambrian Research, Vol. 47, No. 1-2, April pp. 83-98New BrunswickGeochemistry, Basalt
DS1992-0337
1992
Dostal, J.Dautria, J.M., Dupuy, C., Takeris, D., Dostal, J.Carbonate metasomatism in the lithospheric mantle-peridotitic xenoliths from a melilitic district of the Sahara BasinContributions to Mineralogy and Petrology, Vol. 111, No. 1, June pp. 37-52AfricaMetasomatism, Melilite
DS1992-0383
1992
Dostal, J.Dostal, J., Mueller, W.Archean shoshonites from the Abitibi greenstone belt, Chibougamau(Quebec, Canada): geochemistry and tectonic settingJournal of Volcanology and Geothermal Research, Vol. 53, pp. 145-165QuebecShoshonites, Geochemistry
DS1992-0402
1992
Dostal, J.Dupuy, C., Liotard, J.M., Dostal, J.Zircon/Hafnium fractionation in intraplate basaltic rocks: carbonate metasomatism in the mantle sourceGeochimica et Cosmochimica Acta, Vol. 56, pp. 2417-2423China, Cook Islands, Zaire, Cape Verde IslandsMantle, Basalts
DS1992-0403
1992
Dostal, J.Dupuy, C., Michard, A., Dostal, J., Dautel, D., Baragar, R.A.Proterozoic flood basalts from the Coppermine River area, NorthwestTerritories: isotope and trace element geochemistryCanadian Journal of Earth Sciences, Vol. 29, No. 9, September pp. 1937-1943Northwest TerritoriesBasalts, Geochemistry
DS1995-0324
1995
Dostal, J.Church, B.N., Dostal, J., Pettipas, A.R.Late Paleozoic gabbroic rocks of the Bridge River accretionary complex, southwestBC: geology and geochemistryGeologische Rundschau, Vol. 84, No. 4, pp. 710-719British ColumbiaGeochemistry, Bridge River Complex
DS1995-0465
1995
Dostal, J.Dupuy, C., Micard. A., Dostal, J., Dautel, D., Baragar, W.R.A.Isotope and trace element geochemistry of Proterozoic Natusiak flood basalts from the northwest Canadian ShieldChemical Geology, Vol. 120, No. 1-2, Feb. 1, pp.15-26OntarioGeochemistry, Natusial basalts
DS1998-0360
1998
Dostal, J.Dostal, J., Owen, J.V.Cretaceous alkaline lamprophyres from northeastern Czech Republic:geochemistry and petrogenesis.Geol. Rundsch., Vol. 87, pp. 67-77.GlobalLamprophyres, Geochemistry
DS2000-0046
2000
Dostal, J.Ayer, J.A., Dostal, J.neodymium and lead isotopes from Lake of the Woods greenstone belt: implications for mantle evolution and crust...Canadian Journal of Earth Sciences, Vol. 37, No.12, Dec. pp. 1677-89.OntarioGeochronology - mantle, Southern Superior Province
DS2002-0342
2002
Dostal, J.Culshaw, N., Dostal, J.Amphibolites of the Swhawanaga domain, Central Gneiss Belt: tectonic setting and implications for relationsPrecambrian Research, Vol. 113, No. 1-2, Jan. pp. 65-85.Ontario, Grenville, MidcontinentTectonics, Midcontinent
DS2002-0393
2002
Dostal, J.Dostal, J., Caby, R., Keppie, J.D., Maza, M.Neoproterozoic magmatism in southwestern Algeria ( Sebkha el Melah Inlier): a northerly extension of the Trans Saharan orogen.Journal of African Earth Sciences, Vol. 35, 2, Aug. pp. 213-25.AlgeriaShoshonite, West African Craton
DS2003-0345
2003
Dostal, J.Dostal, J., Brietsprecher, K., Church, B.N., Thorkelson, D., Hamilton, T.S.Eocene melting of Precambrian lithospheric mantle: analcime bearing volcanic rocksJournal of Volcanology and Geothermal Research, Vol. 126, 3-4, Aug. 20, pp. 303-326.British ColumbiaMetasomatism
DS200412-0471
2003
Dostal, J.Dostal, J., Brietsprecher, K., Church, B.N., Thorkelson, D., Hamilton, T.S.Eocene melting of Precambrian lithospheric mantle: analcime bearing volcanic rocks from the Challis Kam loops belt of south centrJournal of Volcanology and Geothermal Research, Vol. 126, 3-4, Aug. 20, pp. 303-326.Canada, British ColumbiaMetasomatism
DS200412-1801
2004
Dostal, J.Shellnutt, J.G., Dostal, J., Keppie, J.D.Petrogenesis of the 723 Ma Coronation sills, Amundsen basin, Arctic Canada: implications for the break-up of Rodinia.Precambrian Research, Vol. 129, 3-4, March 10, pp. 309-324.Canada, ArcticGeochronology
DS200512-0245
2005
Dostal, J.Dostal, J., Keppie, J.D., Hamilton, M.A., Araab, E.M., Lefort, J.P., Murphy, J.B.Crustal xenoliths in Triassic lamprophyre dykes in western Morocco: tectonic implications for the Rheic Ocean suture.Geological Magazine, Vol. 142, 2, pp. 159-172.Africa, MoroccoLamprophyre
DS200512-0365
2005
Dostal, J.Greenough, J.D., Dostal, J., Mallory-Greenough, L.M.Igneous rock association- pt. 4 Oceanic volcanism 1 mineralogy and petrology.Geoscience Canada, Vol. 32, 1, March pp. 29-45.MantleHotspots, tectonics, basalts
DS200712-0764
2007
Dostal, J.Murphy, J.B., Dostal, J.Continental mafic magmatism of different ages in the same terrane: constraints on the evolution of an enriched mantle source.Geology, Vol. 35, 4, pp. 335-338.MantleMagmatism
DS201605-0829
2016
Dostal, J.Dostal, J.Rare metal deposits associated with alkaline/peralkaline igneous rocks.SEG Reviews in Economic Geology, editors Verplanck, P.L., Hitzman, M.W., No. 18, pp. 33-54.Canada, Northwest Territories, Ontario, Europe, Greenland, Russia, Sweden, Africa, South AfricaThor, Nechalacho, Ilmmassaq, Loverzero, Kipawa, Noira Karr, Planesberg
DS201702-0211
2016
Dostal, J.Dostal, J.Rare metal deposits associated with alkaline/peralkaline igneous rocks.Reviews in Economic Geology, Vol. 18, pp. 33-54.GlobalAlkalic

Abstract: Highly evolved alkaline/peralkaline igneous rocks host deposits of rare earth elements (REE) including Y as well as Zr, Hf, Nb, Ta , U and Th. The host rocks spanning from silica-undersaturated (nepheline syenites) to silica-oversaturated (granites) occur in intraplate tectonic environments, mainly in continental settings and are typically associated with rifting, faulting and/or crustal extension. They range in age from Neoarchean/Paleoproterozoic to Mesozoic, but several significant deposits are of Mesoproterozoic age. The deposits/prospects can be subdivided into three types. The first is hosted by nepheline syenitic rocks of large, layered alkaline intrusions where the mineralization commonly occurs in layers rich in REE-bearing minerals which mostly show cumulate textures (e.g., Thor Lake/Nechalacho, Canada; Ilimaussaq, Greenland; Lovozero, Russia; Kipawa, Canada; Norra Kärr, Sweden; Pilanesberg, South Africa). The second type includes mineralization in peralkaline granitic rocks where REE-bearing minerals are usually disseminated. The mineralization is typically hosted by pegmatites (including the NYF-type), felsic dikes and minor granitic intrusions (e.g., Strange Lake, Canada; Khaldzan-Buregtey, Mongolia; Ghurayyah, Saudi Arabia; Bokan, Alaska, United States). The third type is disseminated and very fine-grained and hosted by peralkaline felsic volcanic/volcaniclastic rocks, mostly of trachytic composition (e.g., Dubbo Zirconia and Brockman/Hastings, Australia). The bulk of the REE is present in ore/accessory minerals which in some mineralized zones, particularly in cumulate rocks from alkaline complexes, can reach >10 vol.%. Mineralization is composed of a variety of REE-bearing minerals which frequently show complex replacement textures. They include fluorocarbonates, phosphates, silicates and oxides. Economically most important are bastnäsite, monazite, xenotime, loparite, eudialyte, synchysite and parasite. Many other minerals are either sparse or it is difficult with present technology to profitably extract REE from them on a commercial scale. Compared to carbonatite-hosted REE deposits, the REE mineralization in alkaline/peralkaline complexes has lower light REE concentrations but has commonly higher contents of heavy REE and Y and shows a relative depletion of Eu. Elevated concentrations of U and Th of the ore assemblages make gamma-ray (radiometric) surveys an important exploration tool. The host peralkaline (granitic, trachytic and nepheline syenitic) magmas undergo extensive fractional crystallization which is protracted in part due to high contents of halogens and alkalis. The REE mineralization in these rocks is related to late stages of magma evolution, and typically records two mineralization periods. The first produces the primary magmatic ore assemblages which are associated with the crystallization of fractionated peralkaline magma rich in rare metals. This assemblage is commonly overprinted during the second period by the late magmatic to hydrothermal fluids which remobilize and enrich the original ore. The parent magmas are derived from a metasomatically enriched mantle-related lithospheric source by very low degrees of partial melting triggered probably by uplift (adiabatic) or mantle plume activity. The rare metal deposits/mineralization related to peralkaline igneous rocks represent one of the most economically important resources of heavy REE including Y. In addition to REE, some of these deposits contain economically valuable concentrations of other rare metals including Zr, Nb, Ta, Hf, Be, U and Th as well as phosphates.
DS1994-1891
1994
Dostal, R.J.Watters, B.R., Dostal, R.J., Slimmon, W.I., Thomas, D.J.Geochemistry, petrogenesis tectonic setting of Early Proterozic volcanic rocks of the Flin Flon DomainNeues Jahr.Min. Pet, Vol. 1994, No. 9, pp. 416-432SaskatchewanGeochemistry, Flin Flon Domain
DS1993-0380
1993
DostalerDumont, R., Kiss, F., Stone, Anderson, Dostaler, JobinAeromagnetic surveys 1992-3. joint ventures -international coloboration MDAGeological Survey of Canada (GSC) Forum 1993, p. E12, F13-14. abstractManitobaGeophysics - magnetics
DS1992-0384
1992
Dott, R.H.Dott, R.H.Eustasy: the historical ups and downs of a major geological conceptGeological Society of America Memoir, No. 180, 110pGlobalBook -table of contents, Sea level changes, eustasy
DS2003-0925
2003
Dott, R.H.Medaris, L.G., Singer, B.S., Dott, R.H., Naymark, A., Johnson, C.M., SchottLate Paleoproterozoic climate, tectonics and metamorphism in the southern LakeJournal of Geology, Vol. 111, 3, pp. 243-258.MichiganTectonics
DS200412-1286
2003
Dott, R.H.Medaris, L.G., Singer, B.S., Dott, R.H., Naymark, A., Johnson, C.M., Schott, R.C.Late Paleoproterozoic climate, tectonics and metamorphism in the southern Lake Superior region and proto North America: evidenceJournal of Geology, Vol. 111, 3, pp. 243-258.United States, MichiganTectonics
DS1975-0730
1978
Dott, R.H.Jr.Dott, R.H.Jr.Tectonics and Sedimentation a Century LaterEarth Sci. Reviews, Vol. 14, PP. 1-34.GlobalGeosynclines, Mid-continent
DS1997-0287
1997
Dott, R.H.Jr.Dott, R.H.Jr.James Dwight Dana's old tectonics - global contraction under divinedirectionAmerican Journal of Science, Vol. 297, No. 3, March pp. 283-311GlobalProfile - Dana, Tectonics
DS201212-0262
2012
Doubleday, N.C.Grimwood, B.S.R., Doubleday, N.C., Ljubicic, G.J., Donaldson, S.G., Blangy, S.Engaged acclimatization: towards responsible community based participatory research in Nunavut.Canadian Geographer, in press availableCanada, NunavutCSR - neologism
DS201809-2004
2018
Doublier, M.P.Calvert, A.J., Doublier, M.P.Archean continental spreading inferred from seismic images of the Yilgarn Craton.Nature Geoscience, Vol. 11, July, pp. 526-530.Australiageophysics - seismic

Abstract: On the early Earth, oceanic plateaux similar to present-day Iceland are thought to have evolved into less dense microcontinents as they thickened by continued melt intrusion and crustal fractionation. These earliest continents may have been so weak on a hotter Earth that they collapsed laterally in response to thickening by further magmatic growth or tectonic imbrication. This continental spreading is likely to have resulted in the development of pervasive ductile strain fabrics in the deeper crust, which, if preserved, could generate seismic reflections. Here we present seismic images from the ancient core of the Archaean Yilgarn Craton of Australia that reveal shallowly dipping to horizontal reflections that pervade the middle and lower crust. We interpret these reflective fabrics as the result of widespread lateral crustal flow during the late stage of craton evolution approximately 2.66 to 2.61?billion years ago, which coincided with the widespread intrusion of high-temperature crustal melts, as thickened early continental crust collapsed. The consequent subsidence of large regions of the upper crust, including volcanic and sedimentary greenstone rocks, in the hanging walls of listric mid-lower crustal ductile flow fabrics caused these rocks to drop beneath the granitic melts rising towards the surface, and did not involve Rayleigh-Taylor instabilities within a mostly mobile crust.
DS201112-1075
2011
Doubrovine, P.V.Van Hinsbergen, D.J.J., Steinberger, B., Doubrovine, P.V., Gassmuller, R.Acceleration and deceleration of India-Asia convergence since the Cretaceous: roles of mantle plumes and continental collision.Journal of Geophysical Research, in press availableIndia, China, AsiaHotspots
DS201607-1293
2016
Doubrovine, P.V.Domeier, M., Doubrovine, P.V., Torsvik, T.H., Spakman, W., Bull, A.L.Global correlation of mantle structure and past subduction.Geophysical Research Letters, Vol. 43, 10, pp. 4945-4953.MantleSubduction

Abstract: Advances in global seismic tomography have increasingly motivated identification of subducted lithosphere in Earth’s deep mantle, creating novel opportunities to link plate tectonics and mantle evolution. Chief among those is the quest for a robust subduction reference frame, wherein the mantle assemblage of subducted lithosphere is used to reconstruct past surface tectonics in an absolute framework anchored in the deep Earth. However, the associations heretofore drawn between lower mantle structure and past subduction have been qualitative and conflicting, so the very assumption of a correlation has yet to be quantitatively corroborated. Here we show that a significant, time-depth progressive correlation can be drawn between reconstructed subduction zones of the last 130 Myr and positive S wave velocity anomalies at 600 -2300 km depth, but that further correlation between greater times and depths is not presently demonstrable. This correlation suggests that lower mantle slab sinking rates average between 1.1 and 1.9 cmyr 1.
DS2000-0243
2000
Douce, A.E.P.Douce, A.E.P.Granulites, crustal melting and heating of the lower crustGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000, 2p. abstract.MantleMelting - not specific to diamonds
DS2002-1504
2002
Douce, A.E.P.Skjerlie, K.P., Douce, A.E.P.The fluid absent partial melting of a zoisite bearing quartz eclogite from 1.0 to 3.2 GPa implications....Journal of Petrology, Vol. 43, No. 2, pp. 291-314.MantleMelting in thickened continental crust, Subduction zone processes
DS201212-0497
2012
Doucekance, R.Mourao, C., Mata, J., Doucekance, R., Madeira, J., Millet, M-A., Moreira, M.Geochemical temporal evolution of Brava Island magmatism: constraints on the variability of Cape Verde mantle sources and on carbonatite-silicate magma link.Chemical Geology, Vol. 334, pp. 44-61.Europe, Cape Verde IslandsCarbonatite
DS200712-0272
2007
Doucelance, R.Doucelance, R., Mata, J., Moreira, M., Silva, L.C.Isotope evidence for the origin of Cape Verde oceanic carbonatites.Plates, Plumes, and Paradigms, 1p. abstract p. A233.Europe, Cape Verde IslandsCarbonatite, geochronology
DS201012-0169
2010
Doucelance, R.Doucelance, R., Hammouda, T., Moreira, M., Martins, J.C.Geochemical constraints on depth of origin of oceanic carbonatites: The Cape Verde Case.Geochimica et Cosmochimica Acta, Vol. 74, 24, pp. 7261-7282.Europe, Cape Verde IslandsCarbonatite
DS201012-0475
2010
Doucelance, R.Mata, J., Moreira, M., Doucelance, R., Ader, M., Silva, L.C.Noble gas and carbon isotopic signatures of Cape Verde oceanic carbonatites: implications for carbon provenance.Earth and Planetary Science Letters, Vol. 291, 1-4, pp. 70-83.Europe, Cape Verde IslandsCarbonatite
DS201012-0519
2009
Doucelance, R.Mourai, C., Mata, J., Doucelance, R., Madeira, J., Brum da Silviera, A., Silva, L.C., Moreira, M.Quaternary extrusive calciocarbonatite volcanism on Brava Island ( Cape Verde): a nephelinite carbonatite immiscibility product.Journal of African Earth Sciences, Vol. 56, 2-3, pp. 59-74.Europe, Cape Verde IslandsCarbonatite
DS201412-0204
2014
Doucelance, R.Doucelance, R., Bellot, N., Boyet, M., Hammouda, T., Bosq, C.What coupled cerium and neodynium isotopes tell us about the deep source of oceanic carbonatites.Earth and Planetary Science Letters, Vol. 407, pp. 175-195.Europe, Cape Verde Islands, Africa, MoroccoCarbonatite
DS200912-0668
2009
Doucet, L.Saumet, S., Bascou, J., Ionov, D., Doucet, L.Seismic properties of the Siberian craton mantle from Udachnaya xenoliths.Goldschmidt Conference 2009, p. A1160 Abstract.Russia, SiberiaDeposit - Udachnaya
DS201012-0309
2010
Doucet, L.Ionov, D.A., Doucet, L., Golovin, A., Ashchepkov, I.Can cratonic mantle be formed in subduction related settings?Goldschmidt 2010 abstracts, AbstractMantleSubduction
DS200912-0185
2009
Doucet, L.S.Doucet, L.S., Ionov, D.A., Ashchepkov, I.New petrographic, major and trace element dat a on lithospheric mantle beneath central Siberian craton.Goldschmidt Conference 2009, p. A302 Abstract.RussiaDeposit - Udachnaya
DS201012-0310
2010
Doucet, L.S.Ionov, D.A., Doucet, L.S., Ashchepkov, I.V.Composition of the lithospheric mantle in the Siberian craton: new constraints from fresh peridotites in the Udachnaya East kimberlite.Journal of Petrology, Vol. 51, 11, pp. 2177-2210.RussiaMantle petrology
DS201112-0063
2011
Doucet, L.S.Bascou, J., Doucet, L.S., Saumet, S., Ionov, D.A., Ashchepkov, I.V., Golovin, A.V.Seismic velocities, anisotropy and deformation in Siberian cratonic mantle: EBSD dat a on xenoliths from the Udachnaya kimberlite.Earth and Planetary Science Letters, Vol. 304, 1-2, pp. 71-84.RussiaDeposit - Udachnaya
DS201112-0287
2011
Doucet, L.S.Doucet, L.S., Ionov, D.A., Carlson, R.W., Golovin, A.V., Ashchepkov, I.V.Os isotope and PGE dat a on the age and evolution of lithospheric mantle in the central Siberian Craton.Goldschmidt Conference 2011, abstract p.777.RussiaUdachnaya kimberlite
DS201112-0380
2011
Doucet, L.S.Goncharov, A.G., Ionov, D.A., Doucet, L.S., Ashchepkov, I.V.Redox state of lithospheric mantle in central Siberian craton: a Mossbauer study of peridotite xenoliths from the Udachnaya kimberlite.Goldschmidt Conference 2011, abstract p.930.RussiaGeochronology
DS201112-0465
2011
Doucet, L.S.Ionov, D.A., Doucet, L.S., Carlson, R.W., Pokhilenko, N.P., Golovin, A.V., Ashchepkov, I.V.Peridotite xenolith inferences on the formation and evolution of the central Siberian cratonic mantle.Goldschmidt Conference 2011, abstract p.1085.Russia, SiberiaUdachnaya
DS201212-0257
2012
Doucet, L.S.Goncharov, A.G., Ionov, D.A., Doucet, L.S., Pokhilenko, L.N.Thermal stress, oxygen fugacity and C O H fluid appreciation in cratonic lithospheric mantle: new dat a on peridotite xenoliths from the Udachnaya kimberlite, Siberia.Earth and Planetary Science Letters, Vol. 357-358, pp. 99-110.RussiaDeposit - Udachnaya
DS201312-0226
2013
Doucet, L.S.Doucet, L.S., Ionov, D.A., Golovin, A.V.The origin of coarse garnet peridotites in cratonic lithosphere: new dat a on xenoliths from the Udachnaya kimberlite, central Siberia.Contributions to Mineralogy and Petrology, Vol. 165, pp. 1225-1242.Russia, SiberiaDeposit - Udachnaya
DS201312-0429
2013
Doucet, L.S.Ionov, D.A., Doucet, L.S., Golovin, A.V.The origin of garnet peridotites in the Siberian cratonic mantle from chemical, modal and textural data.Goldschmidt 2013, AbstractRussia, SiberiaDeposit - Udachnaya
DS201412-0205
2014
Doucet, L.S.Doucet, L.S., Ionov, D.A., Golovin, A.V.Paleoproterozoic formation age for the Siberian cratonic mantle: Hf and Nd isotope dat a on refractory peridotite xenoliths from the Udachnaya kimberlite.Chemical Geology, Vol. 391, pp. 42-55.RussiaDeposit - Udachnaya
DS201412-0206
2014
Doucet, L.S.Doucet, L.S., Peslier, A.H., Ionov, D.A.High water contents in the Siberian cratonic mantle linked to metasomatism: an FTOR study of Udachnaya peridotite xenoliths.Geochimica et Cosmochimica Acta, Vol. 137, pp. 159-187.Russia, YakutiaDeposit - Udachnaya
DS201412-0208
2014
Doucet, L.S.Doucet, L.S., Peslier, A.H., Ionov, D.A., Brandon, A.D., Golovin, A.V., Goncharov, A.G., Ashchepkov, I.V.High water contents in the Siberian cratonic mantle linked to metasomatism: an FTIR study of Udachnaya peridotite xenoliths.Geochimica et Cosmochimica Acta, in press availableRussia, SiberiaDeposit - Udachnaya
DS201509-0401
2015
Doucet, L.S.Ionov, D.A., Carlson, R.W., Doucet, L.S., Golovin, A.V., Oleinikov, O.B.The age and history of the lithospheric mantle of the Siberian craton: Re-Os and PGE study of peridotite xenoliths from the Obnazhennaya kimberlite.Earth and Planetary Science Letters, Vol. 428, pp. 108-119.Russia, SiberiaDeposit - Obnazhennaya

Abstract: The formation age of the lithospheric mantle of the Siberian craton (one of the largest on Earth) is not well established; nearly all published whole-rock Re–Os data are for mantle xenoliths from a single kimberlite in the center of the craton (Udachnaya). We report Re–Os isotope and PGE concentration data for 19 spinel and garnet peridotite xenoliths from the Obnazhennaya kimberlite in the northeastern portion of the craton. Most samples in this study, and many Obnazhennaya peridotites in general, show a combination of relatively low Al2O3 (0.1–2%) with high CaO (1.4–4%) concentrations. Only four dunites and harzburgites in our sample suite have low contents of both Al2O3 and CaO (0.1–0.8%), but their relatively low Mg# (0.888–0.919) and highly variable Os concentrations (0.6–35 ppb) suggest they may have formed in melt migration channels rather than as residues of partial melt extraction. A group of six Ca-rich (2.0–3.2% CaO) peridotites yields the highest Re–Os model ages (mean TRD = 2.8 Ga, mean TMA = 3.5 Ga). Eight peridotites with low to moderate Al2O3 (<2%) and Mg# =0.91, including three low-Ca harzburgites, yield lower Re–Os model ages (mean TRD = 1.9 Ga, mean TMA = 2.2 Ga). The remainder of the samples may not yield meaningful TRD ages because they are not refractory (Al2O3 >2.6% and/or Mg# =0.90). We interpret these results as evidence for a two-stage formation of the lithospheric mantle. The peridotites formed at the two stages show very similar chemical compositions. The enrichment in Ca, which we attribute to widespread post-melting metasomatism by carbonate-rich melts, may have taken place either at the end of the Archean melting event, when at least one Ca–Al-rich peridotite was formed, or later. The combined Re–Os age data on xenoliths from Obnazhennaya and Udachnaya suggest that the lithospheric mantle beneath the Siberian craton was not formed in a single event, but grew in at least two events, one in the late Archean and the other in the Paleoproterozoic. This study further indicates that the formation of highly melt-depleted lithospheric mantle was not limited to the Archean, but continued well into the Paleoproterozoic when the Siberian craton was stabilized.
DS201610-1859
2016
Doucet, L.S.Doucet, L.S., Mattielli, N., Ionov, D.A., Debouage, W., Golovin A.V.Zn isotopic heterogeneity in the mantle: a melting control?Earth and Planetary Science Letters, Vol. 451, pp. 232-240.MantlePeridotite

Abstract: We present new Zn elemental and isotope data on seventeen fertile and refractory mantle peridotite xenoliths. Eleven fertile peridotites are garnet and spinel lherzolites from Vitim and Tariat (Siberia and Mongolia) and represent some of the most pristine fertile peridotites available. Six refractory peridotites are spinel harzburgites from the Udachnaya kimberlite (Siberian craton) that are nearly pristine residues of high-degree polybaric melting at high pressure (7-4 GPa). Geochemical data suggest that Zn isotopic compositions in the peridotites have not been affected by post-melting processes such as metasomatism, contamination by the host-magmas or alteration. The fertile peridotites have uniform Zn concentrations (59±2 ppm59±2 ppm) and Zn isotopic compositions with d66Zn (relative to JMC-Lyon-03-0749l)?=?+0.30?±?0.03‰ consistent with the Bulk Silicate Earth estimates of d66Zn?=?+0.28?±?0.05‰ (Chen et al., 2013). The refractory peridotites have Zn concentrations ranging from 30 to 48 ppm and d66Zn from +0.10±0.01‰+0.10±0.01‰ to +0.18±0.01‰+0.18±0.01‰ with an average of +0.14±0.03‰+0.14±0.03‰. Our data suggest that the lithospheric mantle has a heterogeneous Zn isotopic composition. Modeling of Zn isotope partitioning during partial melting of fertile mantle suggests that high degrees of melt extraction (>30%) may significantly fractionate Zn isotopes (up to 0.16‰) and that during mantle melting, Zn concentrations and isotopic compositions are mainly controlled by the stability of clinopyroxene and garnet within the melting residue. Because the stability of clinopyroxene and garnet is mainly pressure dependent we suggest that both the depth and the degrees of melt extraction may control Zn isotope fractionation during mantle melting.
DS201610-1874
2016
Doucet, L.S.Jean, M.M., Taylor, L.A., Howarth, G.H., Peslier, A.H., Fedele, L., Bodnar, R.J., Guan, Y., Doucet, L.S., Ionov, D.A., Logvinova, A.M., Golovin, A.V., Sobolev, N.V.Olivine inclusions in Siberian diamonds and mantle xenoliths: contrasting water and trace -element contents.Lithos, in press available 11p.Russia, SiberiaDiamond inclusions
DS201712-2693
2017
Doucet, L.S.Ionov, D.A., Doucet, L.S., Pogge von Strandmann, A.E., Golovin, A.V., Korsakov, A.V.Links between deformation, chemical enrichment and Li isotope compositions in the lithospheric mantle of the central Siberian craton.Chemical Geology, Vol. 475, pp. 105-121.Russia, Siberiacraton, geochronology

Abstract: We report the concentrations ([Li]) and isotopic compositions of Li in mineral separates and bulk rocks obtained by MC-ICPMS for 14 previously studied garnet and spinel peridotite xenoliths from the Udachnaya kimberlite in the central Siberian craton as well as major and trace element compositions for a new suite of 13 deformed garnet peridotites. The deformed Udachnaya peridotites occur at > 5 GPa; they are metasomatized residues of melt extraction, which as a group experienced greater modal and chemical enrichments than coarse peridotites. We identify two sub-groups of the deformed peridotites: (a) mainly cryptically metasomatized (similar to coarse peridotites) with relatively low modal cpx (< 6%) and garnet (< 7%), low Ca and high Mg#, sinusoidal REE patterns in garnet, and chemically unequilibrated garnet and cpx; (b) modally metasomatized with more cpx and garnet, higher Ca, Fe and Ti, and equilibrated garnet and cpx. The chemical enrichments are not proportional to deformation degrees. The deformation in the lower lithosphere is caused by a combination of localized stress, heating and fluid ingress from the pathways of ascending proto-kimberlite melts, with metasomatic media evolving due to reactions with wall rocks. Mg-rich olivine in spinel and coarse garnet Udachnaya peridotites has 1.2-1.9 ppm Li and d7Li of 1.2-5.0‰, i.e. close to olivine in equilibrated fertile to depleted off-craton mantle peridotites from literature data, whereas olivine from the deformed peridotites has higher [Li] (2.4-7.5 ppm) and a broader range of d7Li (1.8-11.6‰), which we attribute to pre-eruption metasomatism. [Li] in opx is higher than in coexisting olivine while ?7LiOl-Opx (d7LiOl - d7LiOpx) ranges from - 6.6 to 7.8‰, indicating disequilibrium inter-mineral [Li] and Li-isotope partitioning. We relate these Li systematics to interaction of lithospheric peridotites with fluids or melts that are either precursors of kimberlite magmatism or products of their fractionation and/or reaction with host mantle. The melts rich in Na and carbonates infiltrated, heated and weakened wall-rock peridotites to facilitate their deformation as well as produce high [Li] and variable, but mainly high, d7Li in olivine. The carbonate-rich melts preferentially reacted with the opx without achieving inter-mineral equilibrium because opx is consumed by such melts, and because of small volumes and uneven distribution of the metasomatic media, as well as short time spans between the melt infiltration and the capture of the wall-rock fragments by incoming portions of ascending kimberlite magma as xenoliths. Trapped interstitial liquid solidified as cryptic components responsible for high [Li] and the lack of d7Li balance between olivine and opx, and bulk rocks. Unaltered d26Mg values (0.20-0.26‰) measured in several olivine separates show no effects of the metasomatism on Mg-isotopes, apparently due to high Mg in the peridotites.
DS201801-0024
2017
Doucet, L.S.Ionov, D.A., Doucet, L.S., Pogge von Strandmann, P.A.E., Golovin, A.V., Korsakov, A.V.Links between deformation, chemical enrichments and Li-isotope compositions in the lithospheric mantle of the central Siberian craton.Chemical Geology, Vol. 475, pp. 105-121.Russiadeposit - Udachnaya

Abstract: We report the concentrations ([Li]) and isotopic compositions of Li in mineral separates and bulk rocks obtained by MC-ICPMS for 14 previously studied garnet and spinel peridotite xenoliths from the Udachnaya kimberlite in the central Siberian craton as well as major and trace element compositions for a new suite of 13 deformed garnet peridotites. The deformed Udachnaya peridotites occur at > 5 GPa; they are metasomatized residues of melt extraction, which as a group experienced greater modal and chemical enrichments than coarse peridotites. We identify two sub-groups of the deformed peridotites: (a) mainly cryptically metasomatized (similar to coarse peridotites) with relatively low modal cpx (< 6%) and garnet (< 7%), low Ca and high Mg#, sinusoidal REE patterns in garnet, and chemically unequilibrated garnet and cpx; (b) modally metasomatized with more cpx and garnet, higher Ca, Fe and Ti, and equilibrated garnet and cpx. The chemical enrichments are not proportional to deformation degrees. The deformation in the lower lithosphere is caused by a combination of localized stress, heating and fluid ingress from the pathways of ascending proto-kimberlite melts, with metasomatic media evolving due to reactions with wall rocks. Mg-rich olivine in spinel and coarse garnet Udachnaya peridotites has 1.2-1.9 ppm Li and d7Li of 1.2-5.0‰, i.e. close to olivine in equilibrated fertile to depleted off-craton mantle peridotites from literature data, whereas olivine from the deformed peridotites has higher [Li] (2.4-7.5 ppm) and a broader range of d7Li (1.8-11.6‰), which we attribute to pre-eruption metasomatism. [Li] in opx is higher than in coexisting olivine while ?7LiOl-Opx (d7LiOl - d7LiOpx) ranges from - 6.6 to 7.8‰, indicating disequilibrium inter-mineral [Li] and Li-isotope partitioning. We relate these Li systematics to interaction of lithospheric peridotites with fluids or melts that are either precursors of kimberlite magmatism or products of their fractionation and/or reaction with host mantle. The melts rich in Na and carbonates infiltrated, heated and weakened wall-rock peridotites to facilitate their deformation as well as produce high [Li] and variable, but mainly high, d7Li in olivine. The carbonate-rich melts preferentially reacted with the opx without achieving inter-mineral equilibrium because opx is consumed by such melts, and because of small volumes and uneven distribution of the metasomatic media, as well as short time spans between the melt infiltration and the capture of the wall-rock fragments by incoming portions of ascending kimberlite magma as xenoliths. Trapped interstitial liquid solidified as cryptic components responsible for high [Li] and the lack of d7Li balance between olivine and opx, and bulk rocks. Unaltered d26Mg values (0.20-0.26‰) measured in several olivine separates show no effects of the metasomatism on Mg-isotopes, apparently due to high Mg in the peridotites.
DS201802-0242
2018
Doucet, L.S.Ionov, D.A., Doucet, L.S., Xu, Y., Golovin, A.V., Oleinikov, O.B.Reworking of Archean mantle in the NE Siberian craton by carbonatite and silicate melt metasomatism: evidence from a carbonate bearing, dunite to web sterite xenolith suite from the Obnazhennaya kimberlite.Geochimica et Cosmochimica Acta, in press available, 46p.Russia, Siberiadeposit - Obnazhennaya

Abstract: The Obnazhennaya kimberlite in the NE Siberian craton hosts a most unusual cratonic xenolith suite, with common rocks rich in pyroxenes and garnet, and no sheared peridotites. We report petrographic and chemical data for whole rocks (WR) and minerals of 20 spinel and garnet peridotites from Obnazhennaya with Re-depletion Os isotope ages of 1.8-2.9 Ga (Ionov et al., 2015a) as well as 2 pyroxenites. The garnet-bearing rocks equilibrated at 1.6-2.8 GPa and 710-1050°C. Some xenoliths contain vermicular spinel-pyroxene aggregates with REE patterns in clinopyroxene mimicking those of garnet. The peridotites show significant scatter of Mg# (0.888-0.924), Cr2O3 (0.2-1.4 wt.%) and high NiO (0.3-0.4 wt.%). None are pristine melting residues. Low-CaO-Al2O3 (=0.9 wt.%) dunites and harzburgites are melt-channel materials. Peridotites with low to moderate Al2O3 (0.4-1.8 wt.%) usually have CaO > Al2O3, and some have pockets of calcite texturally equilibrated with olivine and garnet. Such carbonates, exceptional in mantle xenoliths and reported here for the first time for the Siberian mantle, provide direct evidence for modal makeover and Ca and LREE enrichments by ephemeral carbonate-rich melts. Peridotites rich in CaO and Al2O3 (2.7-8.0 wt.%) formed by reaction with silicate melts. We infer that the mantle lithosphere beneath Obnazhennaya, initially formed in the Mesoarchean, has been profoundly modified. Pervasive inter-granular percolation of highly mobile and reactive carbonate-rich liquids may have reduced the strength of the mantle lithosphere leading the way for reworking by silicate melts. The latest events before the kimberlite eruption were the formation of the carbonate-phlogopite pockets, fine-grained pyroxenite veins and spinel-pyroxene symplectites. The reworked lithospheric sections are preserved at Obnazhennaya, but similar processes could erode lithospheric roots in the SE Siberian craton (Tok) and the North China craton, where ancient melting residues and reworked garnet-bearing peridotites are absent.The modal, chemical and Os-isotope compositions of the Obnazhennaya xenoliths produced by reaction of refractory peridotites with melts are very particular (high Ca/Al, no Mg#-Al correlations, highly variable Cr, low 187Os/188Os, continuous modal range from olivine-rich to low-olivine peridotites, wehrlites and websterites) and distinct from those of fertile lherzolites in off-craton xenoliths and peridotite massifs. These features argue against the concept of ‘refertilization’ of cratonic and other refractory peridotites by mantle-derived melts as a major mechanism to form fertile to moderately depleted lherzolites in continental lithosphere. The Obnazhennaya xenoliths represent a natural rock series produced by ‘refertilization’, but include no rocks equivalent in modal, major and trace element to the fertile lherzolites. This study shows that ‘refertilization’ yields broad, continuous ranges of modal and chemical compositions with common wehrlites and websterites that are rare among off-craton xenoliths.
DS201902-0279
2018
Doucet, L.S.Ionov, D.A., Doucet, L.S., Xu, Y., Golovin, A.V., Oleinikov, O.B.Reworking of Archean mantle in the NE Siberian craton by carbonatite and silicate melt metasomatism: evidence from a carbonate bearing, dunite to websterite xenolith suite from the Obnazhennaya kimberlite.Geochimica et Cosmochimica Acta, Vol. 224, pp. 132-153.Russia, Siberiadeposit - Obnazhennaya

Abstract: The Obnazhennaya kimberlite in the NE Siberian craton hosts a most unusual cratonic xenolith suite, with common rocks rich in pyroxenes and garnet, and no sheared peridotites. We report petrographic and chemical data for whole rocks (WR) and minerals of 20 spinel and garnet peridotites from Obnazhennaya with Re-depletion Os isotope ages of 1.8-2.9?Ga (Ionov et al., 2015a) as well as 2 pyroxenites. The garnet-bearing rocks equilibrated at 1.6-2.8?GPa and 710-1050?°C. Some xenoliths contain vermicular spinel-pyroxene aggregates with REE patterns in clinopyroxene mimicking those of garnet. The peridotites show significant scatter of Mg# (0.888-0.924), Cr2O3 (0.2-1.4?wt.%) and high NiO (0.3-0.4?wt.%). None are pristine melting residues. Low-CaO-Al2O3 (=0.9?wt.%) dunites and harzburgites are melt-channel materials. Peridotites with low to moderate Al2O3 (0.4-1.8?wt.%) usually have CaO?>?Al2O3, and some have pockets of calcite texturally equilibrated with olivine and garnet. Such carbonates, exceptional in mantle xenoliths and reported here for the first time for the Siberian mantle, provide direct evidence for modal makeover and Ca and LREE enrichments by ephemeral carbonate-rich melts. Peridotites rich in CaO and Al2O3 (2.7-8.0?wt.%) formed by reaction with silicate melts. We infer that the mantle lithosphere beneath Obnazhennaya, initially formed in the Mesoarchean, has been profoundly modified. Pervasive inter-granular percolation of highly mobile and reactive carbonate-rich liquids may have reduced the strength of the mantle lithosphere leading the way for reworking by silicate melts. The latest events before the kimberlite eruption were the formation of the carbonate-phlogopite pockets, fine-grained pyroxenite veins and spinel-pyroxene symplectites. The reworked lithospheric sections are preserved at Obnazhennaya, but similar processes could erode lithospheric roots in the SE Siberian craton (Tok) and the North China craton, where ancient melting residues and reworked garnet-bearing peridotites are absent. The modal, chemical and Os-isotope compositions of the Obnazhennaya xenoliths produced by reaction of refractory peridotites with melts are very particular (high Ca/Al, no Mg#-Al correlations, highly variable Cr, low 187Os/188Os, continuous modal range from olivine-rich to low-olivine peridotites, wehrlites and websterites) and distinct from those of fertile lherzolites in off-craton xenoliths and peridotite massifs. These features argue against the concept of ‘refertilization’ of cratonic and other refractory peridotites by mantle-derived melts as a major mechanism to form fertile to moderately depleted lherzolites in continental lithosphere. The Obnazhennaya xenoliths represent a natural rock series produced by ‘refertilization’, but include no rocks equivalent in modal, major and trace element to the fertile lherzolites. This study shows that ‘refertilization’ yields broad, continuous ranges of modal and chemical compositions with common wehrlites and websterites that are rare among off-craton xenoliths.
DS202001-0010
2019
Doucet, L.S.El Dien, H.G., Doucet, L.S., Li, Z-X.Global geochemical fingerprinting of plume intensity suggests coupling with the supercontinent cycle.Nature Communications, Vol 10, 1, doi.org/10.1038 /s41467-019-13300 8p. PdfMantleplumes, hotspots

Abstract: Plate tectonics and mantle plumes are two of the most fundamental solid-Earth processes that have operated through much of Earth history. For the past 300 million years, mantle plumes are known to derive mostly from two large low shear velocity provinces (LLSVPs) above the core-mantle boundary, referred to as the African and Pacific superplumes, but their possible connection with plate tectonics is debated. Here, we demonstrate that transition elements (Ni, Cr, and Fe/Mn) in basaltic rocks can be used to trace plume-related magmatism through Earth history. Our analysis indicates the presence of a direct relationship between the intensity of plume magmatism and the supercontinent cycle, suggesting a possible dynamic coupling between supercontinent and superplume events. In addition, our analysis shows a consistent sudden drop in MgO, Ni and Cr at ~3.2-3.0 billion years ago, possibly indicating an abrupt change in mantle temperature at the start of global plate tectonics.
DS202003-0335
2020
Doucet, L.S.Doucet, L.S., Li, Z-X., Ernst, R.E., Kirscher, U., Gamel El Dien, H., Mitchell, R.N.Coupled supercontinent-mantle plume events evidence by oceanic plume record.Geology, Vol. 48, pp. 159-163.Mantle, Africageodynamics

Abstract: The most dominant features in the present-day lower mantle are the two antipodal African and Pacific large low-shear-velocity provinces (LLSVPs). How and when these two structures formed, and whether they are fixed and long lived through Earth history or dynamic and linked to the supercontinent cycles, remain first-order geodynamic questions. Hotspots and large igneous provinces (LIPs) are mostly generated above LLSVPs, and it is widely accepted that the African LLSVP existed by at least ca. 200 Ma beneath the supercontinent Pangea. Whereas the continental LIP record has been used to decipher the spatial and temporal variations of plume activity under the continents, plume records of the oceanic realm before ca. 170 Ma are mostly missing due to oceanic subduction. Here, we present the first compilation of an Oceanic Large Igneous Provinces database (O-LIPdb), which represents the preserved oceanic LIP and oceanic island basalt occurrences preserved in ophiolites. Using this database, we are able to reconstruct and compare the record of mantle plume activity in both the continental and oceanic realms for the past 2 b.y., spanning three supercontinent cycles. Time-series analysis reveals hints of similar cyclicity of the plume activity in the continent and oceanic realms, both exhibiting a periodicity of ~500 m.y. that is comparable to the supercontinent cycle, albeit with a slight phase delay. Our results argue for dynamic LLSVPs where the supercontinent cycle and global subduction geometry control the formation and locations of the plumes.
DS202007-1136
2020
Doucet, L.S.Doucet, L.S., Xu, Y., Klaessens, D., Hui, H., Ionov, D.A., Mattielli, N.Decoupled water and iron enrichments in the cratonic mantle: a study on peridotite xenoliths from Tok, SE Siberian craton.American Mineralogist, Vol. 105, pp. 803-819.Russia, Siberia peridotites

Abstract: Water and iron are believed to be key constituents controlling the strength and density of the lithosphere and, therefore, play a crucial role in the long-term stability of cratons. On the other hand, metasomatism can modify the water and iron abundances in the mantle and possibly triggers thermo-mechanical erosion of cratonic keels. Whether local or large scale processes control water distribution in cratonic mantle remains unclear, calling for further investigation. Spinel peridotite xenoliths in alkali basalts of the Cenozoic Tok volcanic field sampled the lithospheric mantle beneath the southeastern margin of the Siberian Craton. The absence of garnet-bearing peridotite among the xenoliths, together with voluminous eruptions of basaltic magma, suggests that the craton margin, in contrast to the central part, lost its deep keel. The Tok peridotites experienced extensive and complex metasomatic reworking by evolved, Ca-Fe-rich liquids that transformed refractory harzburgite to lherzolite and wehrlite. We used polarized Fourier transform infrared spectroscopy (FTIR) to obtain water content in olivine, orthopyroxene (Opx), and clinopyroxene (Cpx) of 14 Tok xenoliths. Olivine, with a water content of 0-3 ppm H2O, was severely degassed, probably during emplacement and cooling of the host lava flow. Orthopyroxene (49-106 ppm H2O) and clinopyroxene (97-300 ppm H2O) are in equilibrium. The cores of the pyroxene grains, unlike olivine, experienced no water loss due to dehydration or addition attributable to interaction with the host magma. The water contents of Opx and Cpx are similar to those from the Kaapvaal, Tanzania, and North China cratons, but the Tok Opx has less water than previously studied Opx from the central Siberian craton (Udachnaya, 28-301 ppm; average 138 ppm). Melting models suggest that the water contents of Tok peridotites are higher than in melting residues, and argue for a post-melting (metasomatic) origin. Moreover, the water contents in Opx and Cpx of Tok peridotites are decoupled from iron enrichments or other indicators of melt metasomatism (e.g., CaO and P2O5). Such decoupling is not seen in the Udachnaya and Kaapvaal peridotites but is similar to observations on Tanzanian peridotites. Our data suggest that iron enrichments in the southeastern Siberian craton mantle preceded water enrichment. Pervasive and large-scale, iron enrichment in the lithospheric mantle may strongly increase its density and initiate a thermo-magmatic erosion. By contrast, the distribution of water in xenoliths is relatively “recent” and was controlled by local metasomatic processes that operate shortly before the volcanic eruption. Hence, water abundances in minerals of Tok mantle xenoliths appear to represent a snapshot of water in the vicinity of the xenolith source regions.
DS202007-1138
2020
Doucet, L.S.El Dien, H.G., Doucet, L.S., Murphy, J.B., Li, Z-X.Geochemical evidence for a widespread mantle re-enrichment 3.2 billion years ago: implications for global-scale plate tectonics.Scientific Reports, Vol. 10, 9461 8 pdfMantlemelting

Abstract: Progressive mantle melting during the Earth’s earliest evolution led to the formation of a depleted mantle and a continental crust enriched in highly incompatible elements. Re-enrichment of Earth’s mantle can occur when continental crustal materials begin to founder into the mantle by either subduction or, to a lesser degree, by delamination processes, profoundly affecting the mantle’s trace element and volatile compositions. Deciphering when mantle re-enrichment/refertilization became a global-scale process would reveal the onset of efficient mass transfer of crust to the mantle and potentially when plate tectonic processes became operative on a global-scale. Here we document the onset of mantle re-enrichment/refertilization by comparing the abundances of petrogenetically significant isotopic values and key ratios of highly incompatible elements compared to lithophile elements in Archean to Early-Proterozoic mantle-derived melts (i.e., basalts and komatiites). Basalts and komatiites both record a rapid-change in mantle chemistry around 3.2 billion years ago (Ga) signifying a fundamental change in Earth geodynamics. This rapid-change is recorded in Nd isotopes and in key trace element ratios that reflect a fundamental shift in the balance between fluid-mobile and incompatible elements (i.e., Ba/La, Ba/Nb, U/Nb, Pb/Nd and Pb/Ce) in basaltic and komatiitic rocks. These geochemical proxies display a significant increase in magnitude and variability after ~3.2 Ga. We hypothesize that rapid increases in mantle heterogeneity indicate the recycling of supracrustal materials back into Earth’s mantle via subduction. Our new observations thus point to a?=?3.2 Ga onset of global subduction processes via plate tectonics.
DS202008-1384
2020
Doucet, L.S.Doucet, L.S., Li, Z-X., Gamel El Dien, H., Pourteau, A., Murphy, B., Collins, W.J., Mattielli, N., Olierook, H.K.H., Spencer, C.J., Mitchell, R.N.Distinct formation history for deep mantle domains reflected in geochemical differences.Nature Geoscience, Vol. 13, pp. 511-515. pdfMantlegeochemistry

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

Abstract: The Earth’s mantle is currently divided into the African and Pacific domains, separated by the circum-Pacific subduction girdle, and each domain features a large low shear-wave velocity province (LLSVP) in the lower mantle. However, it remains controversial as to whether the LLSVPs have been stationary through time or dynamic, changing in response to changes in global subduction geometry. Here we compile radiogenic isotope data on plume-induced basalts from ocean islands and oceanic plateaus above the two LLSVPs that show distinct lead, neodymium and strontium isotopic compositions for the two mantle domains. The African domain shows enrichment by subducted continental material during the assembly and breakup of the supercontinent Pangaea, whereas no such feature is found in the Pacific domain. This deep-mantle geochemical dichotomy reflects the different evolutionary histories of the two domains during the Rodinia and Pangaea supercontinent cycles and thus supports a dynamic relationship between plate tectonics and deep-mantle structures.
DS202001-0007
2019
Doucet, L-S.Doucet, L-S., Li, Z-X., Kirscher, U., El Dien, H.G.Coupled supercontinent -mantle plume events evidenced by oceanic plume record.Geology, Vol. 48, 5p. Mantleplumes, hotspots
DS1994-1250
1994
Doucet, P.Mueller, W., Donaldson, J.A., Doucet, P.Volcanic and tectono-plutonic influences on sedimentation in the Archean Kirkland Basin, AbitibiPrecambrian Research, Vol. 68, No. 3-4, August pp. 201-230OntarioGreenstone belt -Abitibi, Tectonics
DS1998-0526
1998
Doucet, P.Goutier, J., Doucet, P., Dion, C., Beausoleil, C.Geologie de la region du lac Esprit (SNRC 33F05)Quebec Department of Mines, RG 98-09, 39p.QuebecGeology
DS1998-0527
1998
Doucet, P.Goutier, J., Doucet, P., Dion, C., Beausoleil, C.Geologie de la region du lac Kowskatehkakmow (SNRC 33F06)Quebec Department of Mines, RG 98-16, 48p.QuebecGeology
DS2001-0649
2001
Doucet, P.Lacroix, S., Doucet, P., Jean, A.Diamond and nickel potential of northern Quebec attracts attentionProspectors and Developers Association of Canada (PDAC) Exploration and development Highlights, pp. 10-11.Quebec, Ungava, LabradorKimberlites, Exploration - discoveries
DS1985-0152
1985
Douchaeva, V.S.Douchaeva, V.S., Borisova, V.V.Geochemistry of Basic Ultrabasic Magmatism of the Kola Peninsula.(russian)Petrol. Kriter. Otsenki Rudn. Dokembr., (Russian), Akad. Nauk SSSR Publishing, pp. 51-64RussiaWebsterite, Harzburgite, Lherzolite
DS201412-0088
2014
Douchet, C.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
DS2002-0669
2002
DoucoureHarvey, J.D., De Wit, M.J., Stankiewicz, J., DoucoureStructural variations of the crust in the southwestern Cape, deduced from seismic receiver functions.South Africa Journal of Geology, Vol. 104, pp. 231-42.South AfricaKaapvaal Craton, Tectonics
DS1994-1259
1994
Doucoure, C.M.Mushayandebvu, M.F., Doucoure, C.M.Regional crustal trends in South Africa from the spectral analysis of topographic and gravity dataJournal of African Earth Sciences, Vol. 19, No. 1-2, July-Aug. pp. 27-34South AfricaRemote sensing, Tectonics, Geophysics -gravity
DS1998-0361
1998
Doucoure, C.M.Doucoure, C.M., De Wit, M.J., Reeves, C.V.Towards a gravity map of Gondwana #1Journal of African Earth Sciences, Vol. 27, 1A, p. 62. AbstractGondwanaGeophysics - gravity
DS2000-0244
2000
Doucoure, C.M.Doucoure, C.M., De Wit, M.J., Reeves, C.V.Towards a gravity map of Gondwana #2Journal of African Earth Sciences, Vol.31, No.1, July, pp.195-204.GondwanaGeophysics - gravity, Map
DS2003-0346
2003
Doucoure, C.M.Doucoure, C.M., De Wit, M.J.Old inherited origin for the present near bimodal topography of AfricaJournal of African Earth Sciences, Vol. 36, 4, May pp. 371-88.AfricaTectonics, gravity, epirogeny, igneous magmatism
DS200412-0472
2003
Doucoure, C.M.Doucoure, C.M., De Wit, M.J.Old inherited origin for the present near bimodal topography of Africa.Journal of African Earth Sciences, Vol. 36, 4, May pp. 371-88.AfricaTectonics, gravity, epirogeny, igneous magmatism
DS1998-0331
1998
Doucoure, M.De Wit, M.J., Thiart, C., Doucoure, M.Gondwana mineralization and metallogenesisJournal of African Earth Sciences, Vol. 27, 1A, p. 58. AbstractGondwanaTectonics, Metallogeny - not specific to diamonds
DS1999-0162
1999
Doucoure, M.De Wit, M., Thiart, C., Doucoure, M., Wilsher, W.Scent of a supercontinent: Gondwana's ores as chemical tracers... tin, tungsten and Neoproterozoic...Journal of African Earth Sciences, Vol. 28, No. 1, pp. 35-51.Gondwana, RodiniaLaurentia - Gondwana connection, Tectonics - not specific to diamonds
DS2001-0122
2001
Dougherty-Page, J.Bons, P.D., Dougherty-Page, J., Elburg, M.A.Stepwise accumulation and ascent of magmasJournal of Metamorphic Geology, Vol. 19, No. 5, Sept. pp. 625-32.MantleMagmatism
DS201312-0227
2013
Doughty, M.Doughty, M., Eyles, N., Eyles, C.High resolution seismic reflection profiling of neotectonic faults in Lake Timiskaming Graben, Ontario-Quebec, Canada.Sedimentology, Vol. 60, 4, pp. 983-1006.Canada, Ontario, QuebecGeophysics - seismics , Kimberlite mentioned
DS1960-0334
1963
Doughty, O.Doughty, O.Early Diamond Days :the Opening of the Diamond Fields of South Africa.London: Longmans Green And Co., 237P.South AfricaHistory, Kimberley
DS1992-0385
1992
Doughty, P.T.Doughty, P.T., Sherriff, S.D.Paleomagnetic evidence for en echelon crustal extension and crustal rotations in western Montana and IdahoTectonics, Vol. 11, No. 3, June pp. 663-671Montana, IdahoPaleomagnetics, Crustal extension
DS1998-0362
1998
Doughty, P.T.Doughty, P.T., Price, R.A., Parrish, R.R.Geology and uranium-lead (U-Pb) geochronology of Archean basement and Proterozoic cover...Cordilleran structure...Canadian Journal of Earth Sciences, Vol. 35, No. 1, Jan. pp. 39-54.British Columbia, Alberta, MontanaTectonics - Precambrian, Basement provinces
DS1987-0161
1987
Douglas, B.J.Douglas, B.J., Saul, S.L., Stern, C.R.Rheology of the upper mantle beneath the Southern most South America inferred from peridotite xenolithsJournal of Geology, Vol. 95, No.2, March pp. 241-254South AmericaMantle genesis
DS1975-0500
1977
Douglas, I.N.Douglas, I.N., Runciman, W.A.Application of Magnetic Circular Diochroism Spectroscopy To the Optical Spectra of Natural and Irradiated Diamonds.Physics And Chemistry of Minerals, Vol. 1, No. 2, PP. 129-136.AustraliaMineralogy, Spectroscopy, Optical Properties
DS1970-0670
1973
Douglas, M.Douglas, M.Kimberley in ColourInternational Publishing SERV., 32P.Australia, Western AustraliaPhotography, Kimberley, General
DS1970-0901
1974
Douglas, McKenna and Partners Pty. Ltd.Douglas, McKenna and Partners Pty. Ltd., Western Mining Corp.El 648 and El 649 Upper Bingara Gulf Creek, Cobbadah Areas Exploration Reports Diamonds.New South Wales Geological Survey, No. GS 1974/354, 54P.Australia, New South WalesProspecting, Sampling, Geochemistry
DS1997-0288
1997
Douglas, R.Douglas, R.Mining trends in Africa. ( Caterpillar Inc. Mining Group presentation)Miga Conference Held Denver June 3-5, 7pAfricaMining
DS1975-0069
1975
Douglas mckenna and partners prop. ltd.Douglas mckenna and partners prop. ltd. , Western Mining CorpEl 648 and El 649 Upper Bingara Gulf Creek Cobbadah Area Diamonds Final Report.New South Wales Geological Survey, No. GS 1975/323, 16P.Australia, New South WalesProspecting, Sampling
DS1995-0818
1995
Douglass, A.Holton, J.R., Haynes, P.H., McIntyre, M.E., Douglass, A.Stratosphere- Troposphere exchangeReviews of Geophysics, Vol. 33, No. 4, Nove, pp. 403-439GlobalGlobal change, Review
DS1993-0371
1993
Doukardt, Y.A.Doukardt, Y.A.On the role of paleorift structures and tectonic control in kimberlite volcanic origin.Diamonds of Yakutia, pp. 119-121.Russia, YakutiaTectonics, Kimberlite origin
DS1995-0435
1995
Doukardt, Yu.A.Doukardt, Yu.A., Boris, E.I.Structural formational and morphological regionalization of the Siberian Platform basement:Proceedings of the Sixth International Kimberlite Conference Almazy Rossii Sakha abstract, p. 24.Russia, YakutiaTectonics, Craton
DS1994-0444
1994
Doukhan, J.C.Doukhan, N., Sautter, V., Doukhan, J.C.Ultradeep, ultramafic mantle xenoliths: transmission electron microscopy preliminary results.Physics of the Earth and Planetary Interiors, Vol. 82, No. 3-4, pp. 195-207.South AfricaXenoliths, Deposit -Jagersfontein
DS1993-0372
1993
Doukhan, J-C.Doukhan, N., Doukhan, J-C., Ingrin, J., Jaoul, RatteronEarly partial melting in pyroxenesAmerican Mineralogist, Vol. 78, pp. 1246-56.MantleMelting - xenoliths
DS1995-0436
1995
Doukhan, J-C.Doukhan, J-C.The phenomenon of early partial meltingC.r. Academy Of Science Paris, *in English, Vol. 320, II app. 1-8.MantleMelt -partial, diopside, TEM.
DS1993-0372
1993
Doukhan, N.Doukhan, N., Doukhan, J-C., Ingrin, J., Jaoul, RatteronEarly partial melting in pyroxenesAmerican Mineralogist, Vol. 78, pp. 1246-56.MantleMelting - xenoliths
DS1994-0444
1994
Doukhan, N.Doukhan, N., Sautter, V., Doukhan, J.C.Ultradeep, ultramafic mantle xenoliths: transmission electron microscopy preliminary results.Physics of the Earth and Planetary Interiors, Vol. 82, No. 3-4, pp. 195-207.South AfricaXenoliths, Deposit -Jagersfontein
DS1985-0153
1985
Doulenc, A.Doulenc, A.The Leucite Hills...wyomingiteLapidary Journal, Vol. 39, No. 9, DECEMBER PP. 64-65.United States, Colorado Plateau, Wyoming, Leucite HillsMineralogy
DS1996-1557
1996
Douma, M.Wolfe, S., Burgess, M., Douma, M., Hyde, C., Robinson, S.Geological and geophysical investigations of ground ice glaciofluvialdeposits, Slave Province.Northwest Territories Exploration Overview, Nov. 26, p. 3-37.Northwest TerritoriesGeological, geophysics, geomorphology, Slave Province
DS2000-0368
2000
Doumnang Mbaigne, J-C.Guiraud, R., Doumnang Mbaigne, J-C.Evidence for a 6000 km length northwest -southeast striking lineament in northern Africa: the Tibesti lineament.Journal of Geological Society of London, Vol. 157, No. 5, Sept.pp. 897-900.Africa, north, Egypt, SudanStructure, Lineaments
DS200912-0183
2009
Doupe, J.P.Doornbos, C., Heaman, L.M., Doupe, J.P., England, J., Simonetti, A., Lejeunesse, P.The first integrated use of in situ U Pb geochronology and geochemical analyses to determine long distance transport of glacial erratics from maIn land Canada into western Arctic Archipelgo.Canadian Journal of Earth Sciences, Vol. 46, 2, pp. 101-122.Canada, Melville PeninsulaGeochronology - western Arctic Archipelago
DS201412-0621
2014
Dousa, W.S.Neto, I.C., Castro, C.C., Silveira, F.V., Cunha, L.M., Weska, R.K., Dousa, W.S.Intrusos kimberliticas de Rondonia: uma sintese com base no conhecimento atual.6 Simposio Brasileiro de Geologia do Diamante, Aug. 3-7, 6p. AbstractSouth America, BrazilRondonia area
DS200612-0396
2006
Douvalis, A.P.Fitzgerald, C.B., Venkatesan, M., Douvalis, A.P., Coey, J.M.Magnetic properties of carbonado diamonds.Journal of Magnetism and Magnetic Materials, Elsevier, Vol. 300, 2, pp. 368-372.TechnologyDiamond morphology
DS1994-0445
1994
Dove, A.Dove, A., Lee, G.Breccia filled diatreme in Permian Illawarra coal measures and Triassicstrata, Kandos, New South Wales.Royal Soc. New South Wales Journal, Vol. 127, pp. 39-45.Australia, New South WalesDiatreme, Xenoliths
DS1910-0177
1911
Dove, K.Dove, K.Deutsch Suedwestafrika. #1In: Das Ueberseeische Deutschland, Union Deutscher Verlagsge, Vol.1, PP. 175-228.Southwest Africa, NamibiaGeology, Kimberley
DS1991-1291
1991
Dove, M.T.Palmer, D.C., Dove, M.T.Phase transition behaviour in natural and synthetic leucite: a structuralperspectiveEos, Spring Meeting Program And Abstracts, Vol. 72, No. 17, April 23, p. 144GlobalLeucite, Mineralogy -crystallography
DS2002-0394
2002
Dove, M.T.Dove, M.T.An introduction to the use of neutron scattering methods in mineral scienceEuropean Journal of Mineralogy, Vol. 14,pp.203-24., Vol. 14,pp.203-24.GlobalMineral behaviour - techniques, Neutron scattering
DS2002-0395
2002
Dove, M.T.Dove, M.T.An introduction to the use of neutron scattering methods in mineral scienceEuropean Journal of Mineralogy, Vol. 14,pp.203-24., Vol. 14,pp.203-24.GlobalMineral behaviour - techniques, Neutron scattering
DS2002-0396
2002
Dove, M.T.Dove, M.T.An introduction to the use of neutron scattering methods in mineral sceincesEuropean Journal of Mineralogy, Vol.14,2,pp.203-24.GlobalTechnology
DS2002-0397
2002
Dove, M.T.Dove, M.T.An introduction to the use of neutron scattering methods in mineral sciencesEuropean Journal of Mineralogy, Vol.14,2,pp.203-24.GlobalTechnology - not specific to diamonds
DS1990-0422
1990
Dover, J.H.Dover, J.H.Problems of terrane terminology- causes and effectsGeology, Vol. 18, No. 6, June pp. 487-488GlobalTerminology, Terranes
DS2002-0398
2002
Dover, M.Dover, M.Following diamonds around the world... the quest for diamond tracking techniques and technologies has generated interesting ideas. the goal remains elusive.Canadian Diamonds, Winter, pp. 14, 16.GlobalNews item, Diamond provenance
DS2002-0399
2002
Dover, M.Dover, M.The rough neighbourhood.. step behind the thick walls and high security and catch a glimpse of life at Ekati sorting house.Canadian Diamonds, Fall, pp. 30-32.Northwest TerritoriesDiamond sorting facility, Deposit - Ekati
DS200412-0473
2002
Dover, M.Dover, M.Following diamonds around the world... the quest for diamond tracking techniques and technologies has generated interesting ideaCanadian Diamonds, Winter, pp. 14, 16.TechnologyNews item - diamond provenance
DS1988-0051
1988
Doveton, J.Berendsen, P., Borcherding, R.M., Doveton, J., Gerhard, L.Texaco Persch # 1, Washington County, Kansas:preliminary geologic report of pre-Phanerozoic rocksKansas Geological Survey Open File Rept, No. 88-22, 116pKansasMidcontinent, Tectonics
DS1991-0641
1991
Doveton, J.H.Hagens, A., Doveton, J.H.Application of a simple cerebellar model to geologic surface mappingComputers and Geosciences, Vol. 17, No. 4, pp. 561-568GlobalComputers, Surface mapping
DS1994-0446
1994
Doveton, J.H.Doveton, J.H.Geologic log analysis using computer methodsAmerican Association of Petroleum Geologists, 169p. approx. 43.00 United StatesGlobalBook -ad, Statistics, oil industry related
DS1991-0398
1991
Dovgal, V.N.Dovgal, V.N.Magmatism of increased alkalinity and upliftsSoviet Geology and Geophysics, Vol. 32, No. 1, pp. 48-51RussiaAlkaline intrusives, Carbonatite, Magmatism
DS200512-0246
2005
Dovgal, V.N.Dovgal, V.N.Nepheline syenites of different alkalinity types of the Altai Sayan area and geologic conditions of their formation.Russian Geology and Geophysics, Vol. 46, 7, pp. 716-724.RussiaAlkalic
DS1989-0108
1989
Dovsteon, J.Berendsen, P., Newell, K.D., Watney, W.L., Dovsteon, J., SteeplesPreliminary report on the Texaco deep Precambrian drill hole in The midcontinent rift systemUnited States Geological Survey (USGS) Open file, United States Geological Survey (USGS)-Missouri G.S. Symp: Mineral resource potential of, p. 2. (abstract.)GlobalTectonics
DS201312-0901
2013
Dowall, D.Tappe, S., Pearson, D.G., Kjarsgaard, B.A., Nowell, G., Dowall, D.Mantle transition zone input to kimberlite magmatism near a subduction zone: origin of anomalous Nd-Hf isotope systematics at Lac de Gras, Canada.Earth and Planetary Science Letters, Vol. 371-372, pp. 235-251.Canada, Northwest TerritoriesGeochronology, convection
DS201312-0903
2013
Dowall, D.Tappe, S., Pearson, D.G., Kjarsgaard, B.A., Nowell, G.M., Dowall, D.Linking kimberlite magmatism, transition zone diamonds, and subduction processes.Goldschmidt 2013, AbstractMantleSubduction
DS2001-0266
2001
Dowall, D.P.Dowall, D.P., Nowell, G.M., Pearson, Kjarsgaard, et al.Geochemistry of Slave and Somerset Island kimberlites29th. Yellowknife Geoscience Forum, Nov. 21-23, abstract p. 13-14.Northwest Territories, Somerset IslandGeochemistry - mantle lithosphere, Deposit - Jericho, Somerset Island
DS2001-0267
2001
Dowall, D.P.Dowall, D.P., Nowell, Pearson, Kjarsgaard, KopylovaComparative geochemistry of the source regions of southern African and Slave kimberlites.Slave-Kaapvaal Workshop, Sept. Ottawa, 6p. abstractNorthwest Territories, South AfricaGeochemistry, Geochronology - Lac de Gras, Contwyoto, Somerset
DS2003-0347
2003
Dowall, D.P.Dowall, D.P., Pearson, D.G., Nowell, G.M., Kjarsgaard, B.A., Armstrong, J.Comparative geochemistry of kimberlites from the Lac de Gras field, NWT - an8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, AbstractNorthwest TerritoriesKimberlite petrogenesis, Geochronology, database 98
DS2003-1050
2003
Dowall, D.P.Pearson, D.G., Nowell, G.M., Dowall, D.P., Kjarsgaard, B.A., Kopylova, M.G.The relative roles of lithosphere and convecting mantle in kimberlites from the Slave8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, AbstractNorthwest TerritoriesKimberlite petrogenesis, Geochronology
DS200412-0474
2003
Dowall, D.P.Dowall, D.P., Pearson, D.G., Nowell, G.M., Kjarsgaard, B.A., Armstrong, J., Hortswood, M.S.A.Comparative geochemistry of kimberlites from the Lac de Gras field, NWT - an integrated isotopic and elemental study.8 IKC Program, Session 7, AbstractCanada, Northwest TerritoriesKimberlite petrogenesis, Database 98
DS200412-1509
2003
Dowall, D.P.Pearson, D.G., Nowell, G.M., Dowall, D.P., Kjarsgaard, B.A., Kopylova, M.G., Armstrong, J.A.The relative roles of lithosphere and convecting mantle in kimberlites from the Slave Province NWT: constraints from Re Os isoto8 IKC Program, Session 7, AbstractCanada, Northwest TerritoriesKimberlite petrogenesis Geochronology
DS200812-0577
2008
Dowall, D.P.Kjarsgaard, B.A., Pearson, D.G., Tappe, S., Nowell, G.M., Dowall, D.P.Kimberlites: high H2O/CO2, MgO rich and K poor silica undersaturated magmas. Lac de Gras9IKC.com, 3p. extended abstractAfrica, South Africa, Canada, Northwest TerritoriesGroup 1 kimberlites
DS200812-0868
2008
Dowall, D.P.Pearson, D.G., Nowell, G.M., Kjarsgaard, B.A., Dowall, D.P.The genesis of kimberlite: geochemical constraints.9IKC.com, 3p. extended abstractCanada, Northwest TerritoriesDeposit - Lac de Gras geochemistry
DS200912-0385
2009
Dowall, D.P.Kjarsgaard, B.A., Pearson, D.G., Tappe, S., Nowell, G.M., Dowall, D.P.Geochemistry of hypabyssal kimberlites from Lac de Gras Canada: comparisons to global database and implications to the parent magma problem.Lithos, In press available, 49p.Canada, Northwest TerritoriesGeochemical - whole rock database
DS1992-0386
1992
Dowd, P.A.Dowd, P.A.A review of recent developments in geostatisticsComputers and Geosciences, Vol. 17, No. 10, pp. 1481-?GlobalComputers, Geostatistics
DS1992-0387
1992
Dowd, P.A.Dowd, P.A.Integrated computer package for geostatistical estimation and modellingTransactions of the Institute of Mining and Metallurgy (IMM), Vol. 101, May-August pp. A95-A102GlobalGeostatistics, Computer Program
DS1992-0388
1992
Dowd, P.A.Dowd, P.A.Geostatistical ore reserve estimation: a case study in a disseminated nickel depositGeological Society Special Publication, Case histories and methods in mineral, No. 63, pp. 243-255GlobalOre reserves, geostatistics, Nickel
DS1994-0447
1994
Dowd, P.A.Dowd, P.A.Risk assessment in reserve estimation and open pit planning #1Institute of Mining and Metallurgy, Vol. 103, pt. A, pp. A 148-154GlobalEconomics, Ore reserves, geostatistics
DS1994-0448
1994
Dowd, P.A.Dowd, P.A.Is research in mining geostats as dead as a dodo? Comments on Armstrong'spaperGeostatistics for the Next Century, pp. 313-314GlobalGeostatistics, Reserve estimates
DS1994-0449
1994
Dowd, P.A.Dowd, P.A., Omar, A.H.Open pit optimization part 1 and part 2 open pit design and scheduling.Institute of Mining and Metallurgy (IMM) Bulletins, pp. A 95-113GlobalMining, Open pit designs
DS1995-0437
1995
Dowd, P.A.Dowd, P.A.Risk assessment in reserve estimation and open pit planning #2Transactions of the Institute of Mining and Metallurgy (IMM), Vol. 104, Sept-Dec. pp. A187-191GlobalEconomics, Ore Reserves, geostatistics
DS1997-0016
1997
Dowd, P.A.Al Dabbagh, M., Dowd, P.A.Saudi Arabia's developing mining industryMining Ind. Int, Sept. pp. 38-44Saudi ArabiaMining, Economics
DS1997-0289
1997
Dowd, P.A.Dowd, P.A.Risk in minerals projects: analysis, perception and managementTransactions of the Institute of Mining and Metallurgy (IMM), Vol. 106, Jan-Apr. pp. A9-18GlobalGIS, geostatistics, Exploration, mining, discoveries, legal
DS2001-0888
2001
Dowd, P.A.Pardo Iguzquiza, E., Dowd, P.A.VARIOG2D: a computer program for estimating the semi-variogram and its uncertainty.Computers and Geosciences, Vol. 27, No. 5, pp. 549-62.GlobalComputer - VARIOG2D.
DS200612-0347
2006
Dowd, P.A.Dowd, P.A., Pardo-Iguzquiza, E.Core log integration: optimal geostatistical signal reconstruction from secondary information.Transactions of the Institution of Mining and Metallurgy, Vol. 115, 2, pp. 59-70.TechnologyGeostatistics - not specific to diamonds
DS1990-0423
1990
Dowdeswell, J.A.Dowdeswell, J.A.Dynamic former ice sheetsNature, Vol. 346, No. 6287 August 30, pp. 795-796OntarioGeomorphology, Laurentide
DS2003-0348
2003
Dowdeswell, J.A.Dowdeswell, J.A., Cofaigh, C.O.Glacier influenced sedimentation on high latitude continental marginsGeological Society of London, Special Publication, No. 203, 378p. $ 142. http://bookshop.geolsoc.org.ukGlobalBook
DS200412-0341
2004
Dowdeswell, J.A.Cofaigh, C.O.,Taylor, J., Dowdeswell, J.A., Pudsey, C.J.Paleo-ice stream, trough mouth fans and high latitude continental slope sedimentation.Boreas, Vol. 32, 1, pp. 37-55.TechnologyGeomorphology - not specific to diamonds
DS200412-0475
2003
Dowdeswell, J.A.Dowdeswell, J.A., Cofaigh, C.O.Glacier influenced sedimentation on high latitude continental margins.Geological Society of London, Special Publication, No. 203, 378p. $ 1 bookshop.geolsoc.org.ukGlobalBook - Geomorphology, glacial, dynamics
DS201510-1787
2015
Dowe, J.McManus, C.E., Dowe, J., McMillan, N.J.Determination of diamond provenance is possible with multivariate analysis of LIBS spectra. ( Laser Induced Breakdown Spectroscopy)GSA Annual Meeting, Paper 300-4, 1p. Abstract only BoothTechnologySpectroscopy

Abstract: The ability to accurately determine the provenance of gem diamonds impacts economic, political, and national security arenas. Currently, provenance determinations rely on: 1) gemological and mineralogical features of stones, such as spectroscopic measurements, geochemistry, and inclusions, and 2) certification and tracking of individual stones through the Kimberly Process Certificate Scheme. Unfortunately, during cutting and polishing, many gemological features are obliterated and tracking individual stones through the chain of custody can be difficult. This study resulted in a highly successful method for determining provenance of cut diamonds from information in the stone itself. A set of 30 cut diamonds from each of ten controlled localities and one set of 30 synthetic diamonds were analyzed by Laser-Induced Breakdown Spectroscopy (LIBS). The sample set (330 total diamonds) includes both kimberlite and placer diamonds from five countries and five different cratons. LIBS acquires the atomic emission spectra released from a material during laser ablation. The spectra contain information from nearly every element in the periodic table, and thus are unique chemical, or quantagenetic, signatures of the material. Spectra were analyzed using a Bayesian statistical method that compares groups of samples defined by the reported locations of the stones to clusters of samples defined by spectral similarity. Ideally, each spectral cluster coincides with a group of stones. The spectrum of each sample is compared to a set of reference spectra from each group to determine the probable provenance of the sample. The correlation between groups and clusters was excellent, with average accuracy of 98%, suggesting that diamonds from each location are spectrally similar to each other and distinct from those from other locations. This is true even for diamonds from kimberlites in close proximity to each other. Synthetic diamonds are easily distinguished from natural diamonds (100% success). Some groups of diamonds in the study are more heterogeneous than others. For instance, a placer group has five recognizable spectrally-defined sub-clusters. This work demonstrates that diamond provenance can be determined at a high level of confidence on individual cut gemstones.
DS201512-1949
2015
Dowe, J.McManus, C.E., Dowe, J., McMillan, N.J.Determination of diamond provenance is possible with multivariate analysis of LIBS spectra.Materialytics.com, Available from c.McManus @materialytics.com 1 poster ( 4 parts)GlobalLaser Induced Breakdown Spectroscopy

Abstract: The ability to accurately determine the provenance of gem diamonds impacts economic, political, and national security arenas. Currently, provenance determinations rely on: 1) gemological and mineralogical features of stones, such as spectroscopic measurements, geochemistry, and inclusions, and 2) certification and tracking of individual stones through the Kimberly Process Certificate Scheme. Unfortunately, during cutting and polishing, many gemological features are obliterated and tracking individual stones through the chain of custody can be difficult. This study resulted in a highly successful method for determining provenance of cut diamonds from information in the stone itself. A set of 30 cut diamonds from each of ten controlled localities and one set of 30 synthetic diamonds were analyzed by Laser-Induced Breakdown Spectroscopy (LIBS). The sample set (330 total diamonds) includes both kimberlite and placer diamonds from five countries and five different cratons. LIBS acquires the atomic emission spectra released from a material during laser ablation. The spectra contain information from nearly every element in the periodic table, and thus are unique chemical, or quantagenetic, signatures of the material. Spectra were analyzed using a Bayesian statistical method that compares groups of samples defined by the reported locations of the stones to clusters of samples defined by spectral similarity. Ideally, each spectral cluster coincides with a group of stones. The spectrum of each sample is compared to a set of reference spectra from each group to determine the probable provenance of the sample. The correlation between groups and clusters was excellent, with average accuracy of 98%, suggesting that diamonds from each location are spectrally similar to each other and distinct from those from other locations. This is true even for diamonds from kimberlites in close proximity to each other. Synthetic diamonds are easily distinguished from natural diamonds (100% success). Some groups of diamonds in the study are more heterogeneous than others. For instance, a placer group has five recognizable spectrally-defined sub-clusters. This work demonstrates that diamond provenance can be determined at a high level of confidence on individual cut gemstones.
DS202012-2232
2020
Dowe, J.McManus, C.E., McMillan, N.J., Dowe, J., Bell, J.Diamonds certify themselves: multivariate statistical provenance analysis.MDPI Minerals, Vol. 10, 916, doi:10.2290/ min0100916, 12p. PdfGlobalspectroscopy

Abstract: The country or mine of origin is an important economic and societal issue inherent in the diamond industry. Consumers increasingly want to know the provenance of their diamonds to ensure their purchase does not support inhumane working conditions. Governments around the world reduce the flow of conflict diamonds via paper certificates through the Kimberley Process, a United Nations mandate. However, certificates can be subject to fraud and do not provide a failsafe solution to stopping the flow of illicit diamonds. A solution tied to the diamonds themselves that can withstand the cutting and manufacturing process is required. Here, we show that multivariate analysis of LIBS (laser-induced breakdown spectroscopy) diamond spectra predicts the mine of origin at greater than 95% accuracy, distinguishes between natural and synthetic stones, and distinguishes between synthetic stones manufactured in different laboratories by different methods. Two types of spectral features, elemental emission peaks and emission clusters from C-N and C-C molecules, are significant in the analysis, indicating that the provenance signal is contained in the carbon structure itself rather than in inclusions.
DS1960-0441
1964
Dowell, A.R.Dowell, A.R.A Magnetic Investigation of Northern Riley County, KansasMsc. Thesis, Kansas State University, 84P.United States, Kansas, Central StatesKimberlite, Geophysics
DS1995-0438
1995
Dowie, M.Dowie, M.Losing ground: American environmentalism at the close of the TwentiethCenturyMit Press, 317p. approx. $ 25.00 United StatesUnited StatesBook -ad, EnvironmentalisM.
DS1995-0801
1995
Dowling, S.E.Hill, R.E.T., Barnes, S.J., Gole, M.J., Dowling, S.E.The volcanology of komatiites as deduced from field relationships in the Norseman-Wiluna greenstone beltLithos, Vol. 34, No. 1-3, Jan. pp. 159-188AustraliaKomatiites, Norseman greenstone belt
DS201802-0231
2017
Dowman, E.Dowman, E., Wall, F., Treloar, P.J., Rankin, A.H.Rare earth mobility as a result of multiple phases of fluid activity in fenite around the Chilwa Island carbonatite, Malawi.Mineralogical Magazine, Vol. 81, 6, pp. 1367-1395.Africa, Malawicarbonatite - Chilwa

Abstract: Carbonatites are enriched in critical raw materials such as the rare earth elements (REE), niobium, fluorspar and phosphate. A better understanding of their fluid regimes will improve our knowledge of how to target and exploit economic deposits. This study shows that multiple fluid phases penetrated the surrounding fenite aureole during carbonatite emplacement at Chilwa Island, Malawi. The first alkaline fluids formed the main fenite assemblage and later microscopic vein networks contain the minerals of potential economic interest such as pyrochlore in high-grade fenite and RE minerals throughout the aureole. Seventeen samples of fenite rock from the metasomatic aureole around the Chilwa Island carbonatite complex were chosen for study (Natural History Museum, London collection BM1968 P37). In addition to the main fenite assemblage of feldspar and aegirine ± arfvedsonite, riebeckite and richterite, the fenite contains micro-mineral assemblages including apatite, ilmenite, rutile, magnetite, zircon, RE minerals and pyrochlore in vein networks. Petrography using SEM-EDX showed that the RE minerals (monazite, bastnäsite and parisite) formed later than the fenite feldspar, aegirine and apatite and provide evidence of REE mobility into all grades of fenite. Fenite apatite has a distinct negative Eu anomaly (determined by LA-ICP-MS) that is rare in carbonatite-associated rocks and interpreted as related to pre-crystallisation of plagioclase and co-crystallisation with K-feldspar in the fenite. The fenite minerals have consistently higher mid REE/light REE ratios (La/Sm = ~1.3 monazite, ~1.9 bastnäsite, ~1.2 parisite) than their counterparts in the carbonatites (La/Sm = ~2.5 monazite, ~4.2 bastnäsite, ~3.4 parisite). Quartz in the low- and medium-grade fenite hosts fluid inclusions, typically a few µm in diameter, secondary and extremely heterogeneous. Single phase, 2- and 3-phase, single solid and multi solid-bearing examples are present, with 2-phase the most abundant. Calcite, nahcolite, burbankite and barite were found in the inclusions. Decrepitation of inclusions occurred at around 200°C before homogenisation but melting temperature data indicate that the inclusions contain relatively pure CO2. A minimum salinity of around 24 wt.% NaCl equivalent was determined. Among the trace elements in whole rock analyses, enrichment in Ba, Mo, Nb, Pb, Sr, Th and Y and depletion in Co, Hf and V are common to carbonatite and fenite but enrichment in carbonatitic type elements (Ba, Nb, Sr, Th, Y, and REE) generally increases towards the inner parts of the aureole. A schematic model contains multiple fluid events, related to first and second boiling of the magma, accompanying intrusion of the carbonatites at Chilwa Island, each contributing to the mineralogy and chemistry of the fenite. The presence of distinct RE mineral micro-assemblages in fenite at some distance from carbonatite could be developed as an exploration indicator of REE enrichment.
DS201802-0233
2018
Dowman, E.Elliott, H.A.L., Wall, F., Chakmouradian, A.R., Siegfried, P.R., Dahlgren, S., Weatherley, S., Finch, A.A., Marks, M.A.W., Dowman, E., Deady, E.Fenites associated with carbonatite complexes: a review.Ore Geology Reviews, Vol. 92, pp. 38-59.Globalcarbonatites

Abstract: Carbonatites and alkaline-silicate rocks are the most important sources of rare earth elements (REE) and niobium (Nb), both of which are metals imperative to technological advancement and associated with high risks of supply interruption. Cooling and crystallizing carbonatitic and alkaline melts expel multiple pulses of alkali-rich aqueous fluids which metasomatize the surrounding country rocks, forming fenites during a process called fenitization. These alkalis and volatiles are original constituents of the magma that are not recorded in the carbonatite rock, and therefore fenites should not be dismissed during the description of a carbonatite system. This paper reviews the existing literature, focusing on 17 worldwide carbonatite complexes whose attributes are used to discuss the main features and processes of fenitization. Although many attempts have been made in the literature to categorize and name fenites, it is recommended that the IUGS metamorphic nomenclature be used to describe predominant mineralogy and textures. Complexing anions greatly enhance the solubility of REE and Nb in these fenitizing fluids, mobilizing them into the surrounding country rock, and precipitating REE- and Nb-enriched micro-mineral assemblages. As such, fenites have significant potential to be used as an exploration tool to find mineralized intrusions in a similar way alteration patterns are used in other ore systems, such as porphyry copper deposits. Strong trends have been identified between the presence of more complex veining textures, mineralogy and brecciation in fenites with intermediate stage Nb-enriched and later stage REE-enriched magmas. However, compiling this evidence has also highlighted large gaps in the literature relating to fenitization. These need to be addressed before fenite can be used as a comprehensive and effective exploration tool.
DS201803-0444
2017
Dowman, E.Dowman, E., Wall, F., Treloar, P.J., Rankin, A.H.Rare earth mobility as a result of multiple phases of fluid activity in fenite around the Chilwa Island carbonatite, Malawi.Mineralogical Magazine, Vol. 81, 6, pp. 1367-1395.Africa, Malawicarbonatite

Abstract: Carbonatites are enriched in critical raw materials such as the rare earth elements (REE), niobium, fluorspar and phosphate. A better understanding of their fluid regimes will improve our knowledge of how to target and exploit economic deposits. This study shows that multiple fluid phases penetrated the surrounding fenite aureole during carbonatite emplacement at Chilwa Island, Malawi. The first alkaline fluids formed the main fenite assemblage and later microscopic vein networks contain the minerals of potential economic interest such as pyrochlore in high-grade fenite and RE minerals throughout the aureole. Seventeen samples of fenite rock from the metasomatic aureole around the Chilwa Island carbonatite complex were chosen for study (Natural History Museum, London collection BM1968 P37). In addition to the main fenite assemblage of feldspar and aegirine ± arfvedsonite, riebeckite and richterite, the fenite contains micro-mineral assemblages including apatite, ilmenite, rutile, magnetite, zircon, RE minerals and pyrochlore in vein networks. Petrography using SEM-EDX showed that the RE minerals (monazite, bastnäsite and parisite) formed later than the fenite feldspar, aegirine and apatite and provide evidence of REE mobility into all grades of fenite. Fenite apatite has a distinct negative Eu anomaly (determined by LA-ICP-MS) that is rare in carbonatite-associated rocks and interpreted as related to pre-crystallisation of plagioclase and co-crystallisation with K-feldspar in the fenite. The fenite minerals have consistently higher mid REE/light REE ratios (La/Sm = ~1.3 monazite, ~1.9 bastnäsite, ~1.2 parisite) than their counterparts in the carbonatites (La/Sm = ~2.5 monazite, ~4.2 bastnäsite, ~3.4 parisite). Quartz in the low- and medium-grade fenite hosts fluid inclusions, typically a few µm in diameter, secondary and extremely heterogeneous. Single phase, 2- and 3-phase, single solid and multi solid-bearing examples are present, with 2-phase the most abundant. Calcite, nahcolite, burbankite and barite were found in the inclusions. Decrepitation of inclusions occurred at around 200°C before homogenisation but melting temperature data indicate that the inclusions contain relatively pure CO2. A minimum salinity of around 24 wt.% NaCl equivalent was determined. Among the trace elements in whole rock analyses, enrichment in Ba, Mo, Nb, Pb, Sr, Th and Y and depletion in Co, Hf and V are common to carbonatite and fenite but enrichment in carbonatitic type elements (Ba, Nb, Sr, Th, Y, and REE) generally increases towards the inner parts of the aureole. A schematic model contains multiple fluid events, related to first and second boiling of the magma, accompanying intrusion of the carbonatites at Chilwa Island, each contributing to the mineralogy and chemistry of the fenite. The presence of distinct RE mineral micro-assemblages in fenite at some distance from carbonatite could be developed as an exploration indicator of REE enrichment.
DS201612-2274
2016
Downe, H.Ashchepkov, I.V., Logvinova, A.M., Ntaflos, T., Vladykin, N.V., Kostrovitsky, S.I., Spetsius, Z., Mityukhin, S.I., Prokopyev, S.A., Medvedev, N.S., Downe, H.Alakit and Daldyn kimberlite fields, Siberia, Russia: two types of mantle sub-terranes beneath central Yakutia?Geoscience Frontiers, in press availableRussia, SiberiaDeposit - Alakit, Daldyn

Abstract: Mineral data from Yakutian kimberlites allow reconstruction of the history of lithospheric mantle. Differences occur in compositions of mantle pyropes and clinopyroxenes from large kimberlite pipes in the Alakit and Daldyn fields. In the Alakit field, Cr-diopsides are alkaline, and Stykanskaya and some other pipes contain more sub-calcic pyropes and dunitic-type diamond inclusions, while in the Daldyn field harzburgitic pyropes are frequent. The eclogitic diamond inclusions in the Alakit field are sharply divided in types and conditions, while in the Daldyn field they show varying compositions and often continuous Pressure-Temperature (P-T) ranges with increasing Fe# with decreasing pressures. In Alakit, Cr-pargasites to richterites were found in all pipes, while in Daldyn, pargasites are rare Dalnyaya and Zarnitsa pipes. Cr-diopsides from the Alakit region show higher levels of light Rare Earth Elements (LREE) and stronger REE-slopes, and enrichment in light Rare Earth Elements (LREE), sometimes Th-U, and small troughs in Nb-Ta-Zr. In the Daldyn field, the High Field Strength Elements HFSE troughs are more common in clinopyroxenes with low REE abundances, while those from sheared and refertilized peridotites have smooth patterns. Garnets from Alakit show HREE minima, but those from Daldyn often have a trough at Y and high U and Pb. PTXfO2 diagrams from both regions show similarities, suggesting similar layering and structures. The degree of metasomatism is often higher for pipes which show dispersion in P-Fe# trends for garnets. In the mantle beneath Udachnaya and Aykhal, pipes show 6-7 linear arrays of P-Fe# in the lower part of the mantle section at 7.5-3.0 GPa, probably reflecting primary subduction horizons. Beneath the Sytykanskaya pipe, there are several horizons with opposite inclinations which reflect metasomatic processes. The high dispersion of the P-Fe# trend indicating widespread metasomatism is associated with decreased diamond grades. Possible explanation of the differences in mineralogy and geochemistry of the mantle sections may relate to their tectonic positions during growth of the lithospheric keel. Enrichment in volatiles and alkalis possibly corresponds to interaction with subduction-related fluids and melts in the craton margins. Incorporation of island arc peridotites from an eroded arc is a possible scenario.
DS201612-2275
2016
Downe, H.Ashchepkov, I.V., Ntaflos, T., Logvinova, A.M., Spetsius, Z.V., Downe, H., Vladykin, N.V.Monomineral universal clinopyroxene and garnet barometers for peridotitic, eclogitic and basaltic systems.Geoscience Frontiers, in press availableTechnologyMineralogy

Abstract: New versions of the universal Jd-Di exchange clinopyroxene barometer for peridotites, pyroxenites and eclogites, and also garnet barometer for eclogites and peridotites were developed. They were checked using large experimental data sets for eclogitic (~530) and peridotitic systems (>650). The precision of the universal Cpx barometer for peridotites based on Jd-Di exchange is close to Cr-Tschermakite method produced by Nimis and Taylor (2000). Cpx barometer was transformed by the substitution of major multiplier for KD by the equations dependent from Al-Na-Fe. Obtained equation in combination with the thermometer of Nimis and Taylor (2000) allow to reconstruct position of the magma feeder systems of the alkali basaltic magma within the mantle diapirs in modern platforms like in Vitim plateau and other Southern Siberia localities and several localities worldwide showing good agreement of pressure ranges for black and green suites. These equations allow construct PTX diagrams for the kimberlite localities in Siberia and worldwide calculating simultaneously the PT parameters for different groups of mantle rocks. They give very good results for the concentrates from kimberlite lamproites and placers with mantle minerals. They are useful for PT estimates for diamond inclusions. The positions of eclogite groups in mantle sections are similar to those determined with new Gar-Cpx barometer produced by C. Beyer et al. (2015). The Fe rich eclogites commonly trace the boundary between the lower upper parts of subcontinental lithospheric mantle (SCLM) at 3-4 GPa marking pyroxenite eclogites layer. Ca-rich eclogites and especially grospydites in SCLM beneath Precambrian kimberlites occurs near pyroxenite layer but in younger mantle sections they became common in the lower parts. The diamondiferous Mg Cr-less group eclogites referring to the ancient island arc complexes are also common in the middle part of mantle sections and near 5-6 GPa. Commonly eclogites in lower apart of mantle sections are remelted and trace the high temperature convective branch. The Mg- and Fe-rich pyroxenites also show the extending in pressure trends which suggest the anatexic melting under the influence of volatiles or under the interaction with plums.
DS2001-0585
2001
DownesKempton, P.D., Downes, Neymark, Wartho, Zartman SharkovGarnet granulite xenoliths from the Northern Baltic Shield - underplated lower crust of paleoproterozoic ..Journal of Petrology, Vol. 42, No. 4, pp. 731-63.Russia, Kola Peninsula, Baltic ShieldLarge igneous province, Metasomatism, geochronology
DS2001-0586
2001
DownesKempton, P.D., Downes, Neymark, Wartho, Zartman, SharkovGarnet granulite xenoliths from the northern Baltic Shield - the underplated lower crust of a paleoprot...Journal of Petrology, Vol. 42, No. 4, Apr. pp. 731-64.Baltic Shield, Kola PeninsulaIgneous Province, Geochronology
DS1985-0154
1985
Downes, H.Downes, H.Tertiary and Quaternary Volcanism of the Massif Central, France.Conference Report of The Meeting of The Volcanics Studies Gr, 1P. ABSTRACT.GlobalGeochronology, Basanite, Petrology
DS1986-0192
1986
Downes, H.Downes, H., Berger, E.T.Geochemical studies of sub-continental lithospheric mantle,massifcentral, FranceTerra Cognita, Vol. 6, No. 1, p. 32. (abstract.)GlobalBlank
DS1990-0424
1990
Downes, H.Downes, H.Shear zones in the upper mantle -relation between geochemical enrichment and deformation in mantleperidotitesGeology, Vol. 18, No. 4, April pp. 374-377GlobalMantle, Peridotites
DS1990-0820
1990
Downes, H.Kempton, P.D., Downes, H., Harmon, R.S.Evidence for lower crustal mixing zones in granulite xenoliths: examples from the French Massif Central and the southwest United States (US)Geological Society of America (GSA) Annual Meeting, Abstracts, Vol. 22, No. 7, p. A255ArizonaMantle, Xenoliths
DS1991-1130
1991
Downes, H.Menzie, M.A., Bodinier, J.L., Thirlwall, M., Downes, H.Asthenosphere-lithosphere relationships within orogenic massifsProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 281-284ItalyThermal boundary layer, hydrofracturing, xenoliths, Proterozoic, classification, characteristics
DS1992-1676
1992
Downes, H.Wilson, M., Downes, H.Mafic alkaline magmatism associated with the European Cenozoic riftsystemTectonophysics, Vol. 208, pp. 173-182EuropeTectonics, Alkaline rocks
DS1994-1170
1994
Downes, H.Menzies, M.A., Bodinier, J.L., Downes, H., Thirlwall, M.Temporal and spatial relationships organic lherzolite massifs -a key understanding depleted and shallow mantle xenoliths.Proceedings of Fifth International Kimberlite Conference, Vol. 1, pp. 423-433.MantleXenoliths, Lherzolites
DS1994-1928
1994
Downes, H.Wilson, M., Rosenbaum, J.M., Downes, H.Evolution of the European mantle lithosphere a Strontium, neodymium, lead isotope perspective.Mineralogical Magazine, Vol. 58A, pp. 979-980. AbstractEuropeBoundary Layer, Mantle
DS1995-0933
1995
Downes, H.Kempton, P.D., Downes, H., Beard, A.Petrology and geochemistry of xenoliths from the northern Baltic shield:evidence for partial melting...Lithos, Vol. 36, No. 3/4, Dec. 1, pp. 157-184.Baltic Shield, Norway, Finland, KolaArchean Terrane, Metasomatism, Xenoliths
DS1996-0099
1996
Downes, H.Beard, A.D., Downes, H., Vetrin, V., Kempton, P.D.Petrogenesis of Devonian lamprophyre and carbonatite minor intrusions, Kandalaksha Gulf (Kola Peninsula).Lithos, Vol. 39, 1-2, Dec. pp. 93-119.RussiaCarbonatite, Kola Peninsula
DS1996-0100
1996
Downes, H.Beard, A.D., Downes, H., Vetrin, V., Kempton, P.D., MaduskiPetrogenesis of Devonian lamprophyre and carbonatite minor intrusions Kandalaksha Gulf, Kola Peninsula.Lithos, Vol. 39, pp. 93-119.Russia, Kola PeninsulaCarbonatite
DS1996-0899
1996
Downes, H.Mason, P.R.D., Downes, H., Mattey, D.Crustal assimilation as a major petrogenetic process in the East Carpathian Neogene and Quat. margin arcJournal of Petrology, Vol. 37, No. 4, Aug. 1, pp. 927-960RomaniaTectonics
DS1998-0093
1998
Downes, H.Beard, A.D., Downes, H., Hegner, E., Sablukov, S.M.Mineralogy and geochemistry of Devonian ultramafic minor intrusions of southern Kola Peninsula.Contributions to Mineralogy and Petrology, Vol. 130, pp. 288-303.Russia, Arkangelsk, Kola PeninsulaKimberlites, mellilites, Petrogenesis
DS1998-0094
1998
Downes, H.Beard, A.D., Mason, P.R.D., Downes, H.Depletion and enrichment processes in lithospheric mantle beneath the Baltic Shield (Kola and Arkangelsk)7th International Kimberlite Conference Abstract, pp. 58-60.Russia, Kola Peninsula, ArkangelskSpinel, garnet peridotites, Xenoliths
DS1998-0954
1998
Downes, H.Mason, P.R.D., Downes, H., Jarvis, K., Vannucci, R.An investigation of incompatible trace elements in Massif Central mantle xenoliths by laser ablation.7th International Kimberlite Conference Abstract, pp. 549-1MantleGeochemistry - ICP-MS, Xenoliths -light rare earth element (LREE).
DS1999-0824
1999
Downes, H.Zangana, N.A., Downes, H., Bea, F.Geochemical variation in peridotite xenoliths and their constituent clinopyroxenes from Ray Pic: implicationsChemical Geology, Vol. 153, No. 1-4, Jan. pp. 11-36.Europe, French Massif CentralMantle - shallow lithosphere