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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
DS202109-1489
2021
Do Cabo, V.Sitnikova, M.A., Do Cabo, V., Wall, F., Goldmann, S.Burbankite and pseudomorphs from the main intrusion calcite carbonatite, Lofdal, Namibia: association, mineral composition, Raman spectroscopy.Mineralogical Magazine, Vol. 85, 4, pp. 496-513.Africa, Namibiadeposit - Lofdal

Abstract: The Neoproterozoic Lofdal alkaline carbonatite complex consists of a swarm of carbonatite dykes and two plugs of calcite carbonatite known as the ‘Main’ and ‘Emanya’ carbonatite intrusions, with associated dykes and plugs of phonolite, syenite, rare gabbro, anorthosite and quartz-feldspar porphyry. In the unaltered Main Intrusion calcite carbonatite the principal rare-earth host is burbankite. As burbankite typically forms in a magmatic environment, close to the carbohydrothermal transition, this has considerable petrogenetic significance. Compositional and textural features of Lofdal calcite carbonatites indicate that burbankite formed syngenetically with the host calcite at the magmatic stage of carbonatite evolution. The early crystallisation of burbankite provides evidence that the carbonatitic magma was enriched in Na, Sr, Ba and light rare earth elements. In common with other carbonatites, the Lofdal burbankite was variably affected by alteration to produce a complex secondary mineral assemblage. Different stages of burbankite alteration are observed, from completely fresh blebs and hexagonal crystals through to complete pseudomorphs, consisting of carbocernaite, ancylite, cordylite, strontianite, celestine, parisite and baryte. Although most research and exploration at Lofdal has focused on xenotime-bearing carbonatite dykes and wall-rock alteration, this complex also contains a more typical calcite carbonatite enriched in light rare earth elements and their alteration products.
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 Săo 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 ?13C 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 ?13C carbonates from -25 to -59‰ are characterized. The formation of abnormally low ?13C in carbonates is determined by the biogenic oxidation of methane from ?13Cmet to -70‰.
DS202104-0571
2021
Dobretsov, N.L.Dobretsov, N.L., Zhmodik, S.M., Lazareva, E.V., Bryanskaya, A.V., Ponomarchuk, V.A., Saryg-ool, B. Yu., Kirichenko, I.S., Tolstov, A.V., Karmanov, N.S.Structural and morphological features of the participation of microorganisms in the formation of Nb-REE-rich ores of the Tomtor field, Russia.Doklady Earth Sciences, Vol. 496, pp. 135-138. Russiadeposit - Tomtor

Abstract: Data indicating the important role of microorganisms in the redistribution of REEs in the weathering crust and the decisive role in the concentration of REEs during the formation of ores in the upper ore horizon of the Tomtor field are obtained. The uptake of REEs was carried out by the community of microorganisms, such as phototrophs, methanogens, methanotrophs, and proteobacteria, which form the basis of the microbiocenosis for this paleoecosystem. The isotopic composition of C carbonates in all samples studied with fossilized microorganisms corresponds to the biogenic one, and the isotopic composition ?18?SMOW (from 7 to 20‰) indicates the endogenous (hydrothermal) and, to a lesser extent, exogenous nature of the solutions. The low (87Sr/86Sr)I values of carbonates (~0.7036-0.7042) exclude the participation of seawater.
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 ?m 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 ?m). 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??m 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.
DS202102-0210
2021
Dokukina, K.A.Mints, M.V., Dokukina, K.A., Afonina, T.B.Precambrian lithosphere beneath Hudson Bay: a new geological model based on the Hudson Bay lithospheric experiment ( HuBLE), Canadian shield.Tectonophysics, Vol. 799, 15p. Doi.org/10.1016/ j.tecto.2020.228701Canada, Ontario, Quebectomography

Abstract: The oval-shaped basin of Hudson Bay occurs near the center of the round-oval Archaean crustal domain of the North American continent. This paper presents models of the geological structure and evolution of the subcontinental lithospheric mantle underlying Hudson Bay and surrounding tectonic provinces based on geological interpretations of regional geological and geophysical data and results of seismic tomography investigations that have been conducted under the Hudson Bay Lithospheric Experiment. The experiment was aimed at lithospheric processes directly related to the origin of the North American craton and the Hudson Bay basin. Hudson Bay is located directly above the lithospheric keel of North America. The geological history demonstrates systematic "renovation" of the basin: (1) origin and evolution of the Neoarchaean Lake Minto basin (~2.75 Ga); (2) accumulation of the Palaeoproterozoic volcanic-sedimentary filling of the epicontinental basin, relics of which is preserved on its passive margins (2.03-1.87 Ga); (3) origin of Ordovician-Late Devonian sedimentary sequence whose maximum thickness reaches 2.5 km; and (4) the development of Late Jurassic-Miocene sediment-filled ring-shaped trough immediately above the lithospheric keel. The Hudson Bay basin occurs above the lithospheric keel in compliance with thermomechanical model of ascending plume. Tomography studies have not detected evidence of either production or transformation of the lithosphere in the Palaeoproterozoic, which are implied by the model of the United Plates of America. Interpretations of tomography data reveal a vertical axial zone in the lithosphere beneath Hudson Bay, which extends from the lithosphere-asthenosphere boundary to the base of the crust or, perhaps, even to the present day surface. The zone is made up of relatively light low-velocity igneous rocks, probably a swarm of kimberlite dikes or pipes. At 2.75 Ga, the North American continent was a single continental mass with Hudson Bay at its center.
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 ?er?ák and ?epišt? sites in the Silesian Unit (Flysch Belt of the Outer Western Carpathians, Czech Republic) host leucocratic dykes and nests which contain accessory minerals enriched in Zr, Nb and REE: Zr-, Nb-rich titanite, zircon, gittinsite, pyrochlore, monazite, REE-rich apatite, epidote, and vesuvianite. Titanite forms wedge-shaped crystals or irregular aggregates enclosed in the analcime groundmass or overgrowths on Zr-rich ferropargasite and taramite or Zr-rich aegirine-augite to aegirine. Titanite crystals show oscillatory or irregular patchy to sector zoning and contain up to 17.7 wt. % ZrO2 and 19.6 wt. % Nb2O5, and ?1.1 wt. % REE2O3. High-field-strength elements (HFSE) are incorporated into the structure of the studied titanite predominantly by substitutions: (i) [6]Ti4+???[6]Zr4+; (ii) [6]Ti4+?+?[6]Al3+???[6]Zr4+?+?[6]Fe3+; and (iii) [6]2Ti4+???[6]Nb5+?+?[6](Al, Fe)3+. Magmatic fractional crystallization, high-temperature hydrothermal autometasomatic overprint and low-temperature hydrothermal alterations resulted in the formation of the HFSE-rich mineral assemblages within the leucocratic teschenites. Autometamorphic processes caused by high-temperature hypersaline aqueous solutions (salinity ~50 wt. %, ~390-510 °C), which were released from the HFSE-enriched residual melt, played a major role in the crystallization of Zr-, Nb-, and REE-rich minerals. The mobilization of HFSE could have occurred either by their sequestration into a fluid phase exsolved from the crystallizing melt or by superimposed alteration processes. The distinctive positive Eu anomaly (EuCN/Eu*?=?1.85) of leucocratic dykes infers possible mixing of Eu2+-bearing magmatic fluids with more oxidized fluids.
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 ?18O and ?13C 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
DS202109-1472
2021
Domack, E.W.Hoffman, P.F., Halverson, G.P., Schrag, D.P., Higgins, J.A., Domack, E.W., Macdonald, F.A., Pruss, S.B., Blattler, C.L., Crockford, P.W., Hodgin, E.B., Bellefroid, E.J., Johnson, B.W., Hodgskiss, M.S.W., Lamothe, K.G., LoBianco, S.J.C., Busch, J.F., HowesSnowballs in Africa: sectioning a long-lived Neoproterozoic carbonate platform and its bathyal foreslope ( NW Namibia). (Octavi Group)Earth Science Reviews , Vol. 219, 103616 231p. PdfAfrica, NamibiaCraton - Congo

Abstract: Otavi Group is a 1.5-3.5-km-thick epicontinental marine carbonate succession of Neoproterozoic age, exposed in an 800-km-long Ediacaran?Cambrian fold belt that rims the SW cape of Congo craton in northern Namibia. Along its southern margin, a contiguous distally tapered foreslope carbonate wedge of the same age is called Swakop Group. Swakop Group also occurs on the western cratonic margin, where a crustal-scale thrust cuts out the facies transition to the platformal Otavi Group. Subsidence accommodating Otavi Group resulted from S?N crustal stretching (770-655?Ma), followed by post-rift thermal subsidence (655-600?Ma). Rifting under southern Swakop Group continued until 650-635?Ma, culminating with breakup and a S-facing continental margin. No hint of a western margin is evident in Otavi Group, suggesting a transform margin to the west, kinematically consistent with S?N plate divergence. Rift-related peralkaline igneous activity in southern Swakop Group occurred around 760 and 746?Ma, with several rift-related igneous centres undated. By comparison, western Swakop Group is impoverished in rift-related igneous rocks. Despite low paleoelevation and paleolatitude, Otavi and Swakop groups are everywhere imprinted by early and late Cryogenian glaciations, enabling unequivocal stratigraphic division into five epochs (period divisions): (1) non-glacial late Tonian, 770-717?Ma; (2) glacial early Cryogenian/Sturtian, 717-661?Ma; (3) non-glacial middle Cryogenian, 661-646?±?5?Ma; (4) glacial late Cryogenian/Marinoan, 646?±?5-635?Ma; and (5) non-glacial early Ediacaran, 635-600?±?5?Ma. Odd numbered epochs lack evident glacioeustatic fluctuation; even numbered ones were the Sturtian and Marinoan snowball Earths. This study aimed to deconstruct the carbonate succession for insights on the nature of Cryogenian glaciations. It focuses on the well-exposed southwestern apex of the arcuate fold belt, incorporating 585?measured sections (totaling >190?km of strata) and?>?8764 pairs of ?13C/?18Ocarb analyses (tabulated in Supplementary On-line Information). Each glaciation began and ended abruptly, and each was followed by anomalously thick ‘catch-up’ depositional sequences that filled accommodation space created by synglacial tectonic subsidence accompanied by very low average rates of sediment accumulation. Net subsidence was 38% larger on average for the younger glaciation, despite its 3.5-9.3-times shorter duration. Average accumulation rates were subequal, 4.0 vs 3.3-8.8?m Myr?1, despite syn-rift tectonics and topography during Sturtian glaciation, versus passive-margin subsidence during Marinoan. Sturtian deposits everywhere overlie an erosional disconformity or unconformity, with depocenters ?1.6?km thick localized in subglacial rift basins, glacially carved bedrock troughs and moraine-like buildups. Sturtian deposits are dominated by massive diamictite, and the associated fine-grained laminated sediments appear to be local subglacial meltwater deposits, including a deep subglacial rift basin. No marine ice-grounding line is required in the 110 Sturtian measured sections in our survey. In contrast, the newly-opened southern foreslope was occupied by a Marinoan marine ice grounding zone, which became the dominant repository for glacial debris eroded from the upper foreslope and broad shallow troughs on the Otavi Group platform, which was glaciated but left nearly devoid of glacial deposits. On the distal foreslope, a distinct glacioeustatic falling-stand carbonate wedge is truncated upslope by a glacial disconformity that underlies the main lowstand grounding-zone wedge, which includes a proximal 0.60-km-high grounding-line moraine. Marinoan deposits are recessional overall, since all but the most distal overlie a glacial disconformity. The Marinoan glacial record is that of an early ice maximum and subsequent slow recession and aggradation, due to tectonic subsidence. Terminal deglaciation is recorded by a ferruginous drape of stratified diamictite, choked with ice-rafted debris, abruptly followed by a syndeglacial-postglacial cap-carbonate depositional sequence. Unlike its Sturtian counterpart, the post-Marinoan sequence has a well-developed basal transgressive (i.e., deepening-upward) cap dolomite (16.9?m regional average thickness, n?=?140) with idiosyncratic sedimentary features including sheet-crack marine cements, tubestone stromatolites and giant wave ripples. The overlying deeper-water calci-rhythmite includes crystal-fans of former aragonite benthic cement ?90?m thick, localized in areas of steep sea-floor topography. Marinoan sequence stratigraphy is laid out over ?0.6?km of paleobathymetric relief. Late Tonian shallow-neritic ?13Ccarb records were obtained from the 0.4-km-thick Devede Fm (~770-760?Ma) in Otavi Group and the 0.7-km-thick Ugab Subgroup (~737-717?Ma) in Swakop Group. Devede Fm is isotopically heavy, +4-8‰ VPDB, and could be correlative with Backlundtoppen Fm (NE Svalbard). Ugab Subgroup post-dates 746?Ma volcanics and shows two negative excursions bridged by heavy ?13C values. The negative excursions could be correlative with Russřya and Garvellach CIEs (carbon isotope excursions) in NE Laurentia. Middle Cryogenian neritic ?13C records from Otavi Group inner platform feature two heavy plateaus bracketed by three negative excursions, correlated with Twitya (NW Canada), Taishir (Mongolia) and Trezona (South Australia) CIEs. The same pattern is observed in carbonate turbidites in distal Swakop Group, with the sub-Marinoan falling-stand wedge hosting the Trezona CIE recovery. Proximal Swakop Group strata equivalent to Taishir CIE and its subsequent heavy plateau are shifted bidirectionally to uniform values of +3.0-3.5‰. Early Ediacaran neritic ?13C records from Otavi Group inner platform display a deep negative excursion associated with the post-Marinoan depositional sequence and heavy values (??+?11‰) with extreme point-to-point variability (?10‰) in the youngest Otavi Group formation. Distal Swakop Group mimics older parts of the early Ediacaran inner platform ?13C records, but after the post-Marinoan negative excursion, proximal Swakop Group values are shifted bidirectionally to +0.9?±?1.5‰. Destruction of positive and negative CIEs in proximal Swakop Group is tentatively attributed to early seawater-buffered diagenesis (dolomitization), driven by geothermal porewater convection that sucks seawater into the proximal foreslope of the platform. This hypothesis provocatively implies that CIEs originating in epi-platform waters and shed far downslope as turbidites are decoupled from open-ocean DIC (dissolved inorganic carbon), which is recorded by the altered proximal Swakop Group values closer to DIC of modern seawater. Carbonate sedimentation ended when the cratonic margins collided with and were overridden by the Atlantic coast-normal Northern Damara and coast-parallel Kaoko orogens at 0.60-0.58?Ga. A forebulge disconformity separates Otavi/Swakop Group from overlying foredeep clastics. In the cratonic cusp, where the orogens meet at a right angle, the forebulge disconformity has an astounding ?1.85?km of megakarstic relief, and km-thick mass slides were displaced gravitationally toward both trenches, prior to orogenic shortening responsible for the craton-rimming fold belt.
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.
DS202108-1272
2021
Domeneghetti, M.C.Barbaro, B.A., Domeneghetti, M.C., Litasov, K.D., Ferriere, L., Pittarello, L., Christ, O., Lorenzon, S., Alvaro, M., Nestola, F.Origin of micrometer-sized impact diamonds in urelilites by catalytic growth involving Fe-Ni-silicide: the example of Kenna meteorite.Geochimica et Cosmochimica Acta, doi.org/10.1016/j.gca.2021.06.022 31p. PdfGlobalmeteorite

Abstract: The occurrence of shock-induced diamonds in ureilite meteorites is common and is used to constrain the history of the ureilite parent bodies. We have investigated a fragment of the Kenna ureilite by micro-X-ray diffraction, micro-Raman spectroscopy and scanning electron microscopy to characterize its carbon phases. In addition to olivine and pigeonite, within the carbon-bearing areas, we identified microdiamonds (up to about 10 ?m in size), nanographite and magnetite. The shock features observed in the silicate minerals and the presence of microdiamonds and nanographite indicate that Kenna underwent a shock event with a peak pressure of at least 15 GPa. Temperatures estimated using a graphite geothermometer are close to 1180 °C. Thus, Kenna is a medium-shocked ureilite, yet it contains microdiamonds, which are typically found in highly shocked carbon-bearing meteorites, instead of the more common nanodiamonds. This can be explained by a relatively long shock event duration (in the order of 4-5 s) and/or by the catalytic effect of Fe-Ni alloys known to favour the crystallization of diamonds. For the first time in a ureilite, carletonmooreite with formula Ni3Si and grain size near 4-7 nm, was found. The presence of nanocrystalline carletonmooreite provides further evidence to support the hypothesis of the catalytic involvement of Fe-Ni bearing phases into the growth process of diamond from graphite during shock events in the ureilite parent body, enabling the formation of micrometer-sized diamond crystals.
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
DS202106-0965
2021
Dominguez-Carretero, D.Pujol-Sola, N., Dominguez-Carretero, D., Proenza, J.A., Haissen, F., Ikenne, M., Gonzales-Jiminez, J.M., Colas, V., Maacha, L., Garcia-Casco, A.The chromitites of the Neoproterozoic Bou Azzer ophiolite ( central Anti-Atlas, Morocco) revisited.Ore Geology Reviews, Vol. 134, 104166, 24p. PdfAfrica, Moroccomoissanite

Abstract: The Neoproterozoic Bou Azzer ophiolite in the Moroccan Anti-Atlas Panafrican belt hosts numerous chromitite orebodies within the peridotite section of the oceanic mantle. The chromitites are strongly affected by serpentinization and metamorphism, although they still preserve igneous relicts amenable for petrogenetic interpretation. The major, minor and trace element composition of unaltered chromite cores reveal two compositional groups: intermediate-Cr (Cr# = 0.60 - 0.74) and high-Cr (Cr# = 0.79 - 0.84) and estimates of parental melt compositions suggest crystallization from pulses of fore-arc basalts (FAB) and boninitic melts, respectively, that infiltrated the oceanic supra-subduction zone (SSZ) mantle. A platinum group elements (PGE) mineralization dominated by Ir-Ru-Os is recognized in the chromitites, which has its mineralogical expression in abundant inclusions of Os-Ir alloys and coexisting magmatic laurite (RuS2) and their products of metamorphic alteration. Unusual mineral phases in chromite, not previously reported in this ophiolite, include super-reduced and/or nominally ultra-high pressure minerals moissanite (SiC), native Cu and silicates (oriented clinopyroxene lamellae), but “exotic” zircon and diaspore have also been identified. We interpret that clinopyroxene lamellae have a magmatic origin, whereas super-reduced phases originated during serpentinization processes and diaspore is linked to late circulation of low-silica fluids related to rodingitization. Zircon grains, on the other hand, with apatite and serpentine inclusions, could either have formed after the interaction of chromitite with mantle-derived melts or could represent subducted detrital sediments later incorporated into the chromitites. We offer a comparison of the Bou Azzer chromitites with other Precambrian ophiolitic chromitites worldwide, which are rather scarce in the geological record. The studied chromitites are very similar to the Neoproterozoic chromitites reported in the Arabian-Nubian shield, which are also related to the Panafrican orogeny. Thus, we conclude that the Bou Azzer chromitites formed in a subduction-initiation geodynamic setting with two-stages of evolution, with formation of FAB-derived intermediate-Cr chromitites in the early stage and formation of boninite-derived high-Cr chromitites in the late stage.
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
DS202105-0769
2021
Donatti-Filho, J.P.Johnson, K., Donatti-Filho, J.P.Brauna 3 mine - South America's first diamond mine developed on a kimberlite deposit.Vancouver Kimberlite Cluster recorded, https://diamonds.eoas. ubc.ca/vancouver kimberliteclusterSouth America, Brazildeposit - Brauna

Abstract: Brazil hosts 1365 kimberlite or kimberlite-like bodies, as well as alluvial diamond deposits that have historically produced the bulk of Brazil's diamond production. Only five kimberlites have been subjected to bulk sampling evaluation using current exploration techniques and diamond recovery technology. The first of these kimberlite deposits to reach commercial production was the Brauna 3 kimberlite, with U-Pb age of 642±6 Ma elocated in the State of Bahia and owned and operated by Lipari Mineracao Ltds. The brauna mine commenced commercial production in 2016 at a capital cost of US $ 65 million, and to date has produced approximately 830,000 cts at an average recovered diamond grade of 21 cpht. The Brauna cluster features two pipe-like bodies, Brauna 3 and Brauna 7, and 22 kimberlite dyke occurrences located on the NE part of the Sao Francisco craton. A robust geological model delineates the Brauna 3 kimberlite pipe to depths of 550 and 410 m below surface for the South and Central-North Lobes, respectively. The geological model reveals a issregularly shapes kimberlite pipe which is structurally controlled by the NW trending strutural lineaments. petrographuic study of the Brauna 3 kimberlite has identified volcaniclastic and coherent kimberlites coexisting in a complex root to diatreme transition zone. The kimberlite is mineralogically close to Group 2 kimberlite containing olivine, spinel, ilmenite, phlogopite, perovskite, apatite, melilite, serpentine, carbonate and sulfates. Geochemically, the Brauna 3 kimberlite is transitional between Group 1 and Group 2 rocks.
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
DS202105-0762
2021
Dong, B.Dong, B., Shi, C., Xu, Z., Wang, K., Luo, H., Sun, F., Wang, P., Wu, E., Zhang, K., Liu, J., Song, Y., Fan, Y.Temperature dependence of optical centers in 1b diamond characteristics by photoluminescence spectra. CVDDiamond & Related Materials, Vol. 116, 108389, 10p. PdfGlobalsynthetics
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.
DS202104-0572
2021
Dong, J.Dong, J., Fischer, R., Stixrude, L., Lithgow-Bertelloni, C.Constraining the volume of Earth's early oceans with a temperature-dependent 2 mantle water storage capacity model.AGU Advances, 1,e2020AV000323Mantlewater

Abstract: At the Earth's surface, the majority of water resides in the oceans, while in the interior, major rock?forming minerals can incorporate significant amounts of water as hydroxyl groups (OH), likely forming another reservoir of water inside the planet. The amount of water that can be dissolved in Earth's mantle minerals, called its water storage capacity, generally decreases at higher temperatures. Over billion?year timescales, the exchange of water between Earth's interior and surface may control the surface oceans' volume change. Here, we calculated the water storage capacity in Earth's solid mantle as a function of mantle temperature. We find that water storage capacity in a hot, early mantle may have been smaller than the amount of water Earth's mantle currently holds, so the additional water in the mantle today would have resided on the surface of the early Earth and formed bigger oceans. Our results suggest that the long?held assumption that the surface oceans' volume remained nearly constant through geologic time may need to be reassessed.
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
DS202107-1098
2021
Dong, S-H.Gao, L-G., Chen, Y-W., Bi, X-W., Gao, J.F., Chen, W.T., Dong, S-H., Luo, J-C., Hu, R-Z.Genesis of carbonatite and associated U-Nb-REE mineralization at Huayang-chuan, central China: insights from mineral paragenesis, chemical and Sr-Nd-C-O isotopic compositions of calcite.Ore Geology Reviews, doi.org/10.1016/j.oregeorev.2021.104310, 50p. PdfChinacarbonatite, REE

Abstract: The Huayangchuan deposit in the North Qinling alkaline province of Central China is a unique carbonatite-hosted giant U-Nb-REE polymetallic deposit. The mineralization is characterized by the presence of betafite, monazite, and allanite as the main ore minerals, but also exhibit relatively high budgets of heavy rare earth elements (HREE = Gd-Lu and Y). The origin of carbonatites has long been controversial, thus hindering our understanding of the genesis of the deposit. Here, we conducted an in-situ trace elemental, Sr-Nd isotopic, and bulk C-O isotopic analyses of multi-type calcites in the deposit. Two principal types (Cal-I and Cal-II), including three sub-types (Cal-I-1, Cal-I-2 and Cal-I-3) of calcites were identified based on crosscutting relationships and calcite textures. Texturally, Cal-I calcites in carbonatites display cumulates with the grain size decreasing from early coarse- (Cal-I-1) to medium- (Cal-I-2) and late fine-grained (Cal-I-3), whereas Cal-II calcites coexist with zeolite displaying zeolite-calcite veinlets. Geochemically, Cal-I calcites contain relatively high REE(Y) (151-2296 ppm), Sr (4947-9566 ppm) and Na (28.6-390 ppm) contents, characterized by right- to left-inclined flat distribution patterns [(La/Yb)N=0.2-4.2] with enrichment of HREE(Y) (136-774 ppm), whereas Cal-II calcites display low REE, Sr and undetectable Na contents, characterized by a right-inclined distribution pattern [(La/Yb)N=13.5, n=16]. The U-Nb-REE mineralization, accompanied with intense and extensive fenitization and biotitization, is mainly associated with the Cal-I-3 calcites which show flat to relatively left-inclined flat REE distribution patterns [(La/Yb)N=0.2-1.0]. Isotopic results show that Cal-I calcites with mantle signatures are primarily igneous in origin, whereas Cal-II are hydrothermal, postdating the U-Nb-REE mineralization. Cal-I calcites (Cal-I-1, Cal-I-2 and Cal-I-3) from mineralized and unmineralized carbonatites, displayed regular changes in REE, Na and Sr contents, but similar trace element distribution patterns and Sr-Nd-C-O isotopic signatures, indicating that these carbonatites originated from the same enriched mantle (EM1) source by low-degree partial melting of HREE-rich carbonated eclogites related to recycled marine sediments. The combination of trace elements and Sr-Nd isotopic composition of calcites further revealed that these carbonatites have undergone highly differentiated evolution. Such differentiation is conducive to the enrichment of ore-forming elements (U-Nb-REE) in the late magmatic-hydrothermal stages owing to extensive ore-forming fluids exsolved from carbonatitic melts. The massive precipitation of the U-Nb-REE minerals from ore-forming hydrothermal fluids may have been triggered by intense fluid-rock reactions indicated by extensive and intense fenitization and biotitization. Therefore, the Huayangchuan carbonatite-related U-Nb-REE deposit may have formed by a combination of processes involving recycled U-Nb-REE-rich marine sediments in the source, differentiation of the produced carbonatitic magmas, and subsequent exsolution of U-Nb-REE-rich fluids that precipitated ore minerals through reactions with wall rocks under the transitional tectonic regime from compression to extension at the end of Late Triassic.
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 ?Nd(T) values of 2.1 ± 0.6 to 6.7 ± 0.3 whereas the ~ 90 Ma perovskites have enriched ?Nd(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?
DS202106-0933
2021
Dongre, A.Dongre, A., Lavhale, P.,Li, Q-L.Perovskite U-Pb age and petrogenesis of the P-12 kimberlite from the Eastern Dharwar craton, southern India: impilcations for a possible linkage at the 1110 Ma large igneous province.Journal of Asian Earth Sciences, Vol.213, 104750, 12p.pdfIndiadeposit -P12

Abstract: Petrology, bulk-rock geochemistry, and perovskite U-Pb age for the P-12 kimberlite pipe from the Wajrakarur kimberlite field, Eastern Dharwar craton (EDC) of southern India is reported. Perovskites yielded a high-precision U-Pb age of 1122 ± 7.7 Ma, taken to be an emplacement age of the host P-12 kimberlite pipe. The groundmass of coherent facies P-12 kimberlite contains monticellite, clinopyroxene, andradite, atoll spinel with titanomagnetite trend, and perovskite with an elevated REE contents. Phlogopite shows restricted Al2O3 and TiO2 contents. Furthermore, olivines with a wider and higher range of core compositions (i.e. Mg# = 84-94) and multi-granular nodules are the hallmark features of the P-12 pipe. This assorted primary mineral content and its composition indicates the transitional nature of the P-12 towards the Kaapvaal lamproites. However, concentrations of bulk-rock major and trace elements in the P-12 and other Wajrakarur kimberlites are similar to the global hypabyssal magmatic kimberlites. Large ion lithophile and high field strength elements (e.g. Ba and Nb) and their ratios (e.g. La/Nb and Th/Nb) suggest the presence of a heterogeneous and lithosphere influenced mantle source region which have been severely overprinted by metasomatizing fluids/melts emanating from the deep sourced upwelling mantle. The presence of such mixed and metasomatized mantle source regions likely to be an important factor for the transitional nature of the P-12 and other Mesoproterozoic kimberlites. Based on the availability of the newest emplacement ages, we propose a geodynamic model for the origin of kimberlites in the Indian subcontinent. The U-Pb age of 1122 ± 7.7 Ma for the P-12 pipe shows its close temporal association to the emplacement of the recently proposed 1110 Ma Large Igneous Province (LIP), with plume center beneath the NW part of the Kalahari craton. Emplacement of the P-12 and other contemporaneous Indian kimberlites, therefore, marks the impingement of mantle plume which contributed heat and triggered partial melting of metasomatized lithospheric mantle without melt input. The eruption phase of ~ 100 million years (i.e. 1050-1153 Ma), for the kimberlites and related rocks in the Indian shield, does not appear to be continuous and can be separated into several short-durational magmatic events. For this reason, small-volume, volatile-rich magmatism during the Mesoproterozoic time in India is linked to the presence of a number of LIPs and associated mantle plumes during Columbia to Rodinia supercontinent transition and assembly of cratonic blocks of the latter.
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 ?18O 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 ?Nd(t) values of 0.0…?1.9. We suggest that basaltic magmas of OIB type (possibly with some the crustal contamination) represent a dominant part of the granitic source. Moreover, the fluorine-enriched fluid phases could provide an additional source of the fluorine. We conclude that most of the mineralization of the Katugin ore deposit occurred during the magmatic stage of the alkaline granitic source melt. The results of detailed mineralogical studies suggest three major types of ores in the Katugin deposit: Zr mineralization, Ta-Nb-REE mineralization and aluminum fluoride mineralization. Most of the ore minerals crystallized from the silicate melt during the magmatic stage. The accessory cryolites in granites crystallized from the magmatic silicate melt enriched in fluorine. However, cryolites in large veins and lens-like bodies crystallized in the latest stage from the fluorine enriched melt. The zircons from the ores in the aegirine-arfvedsonite granite have been dated at 2055?±?7?Ma. This age is close to the previously published 2066?±?6?Ma zircon age of the aegirine-arfvedsonite granites, suggesting that the formation of the Katugin rare-metal deposit is genetically related to the formation of peralkaline granites. We conclude that Katugin rare-metal granites are anorogenic. They can be related to a Paleoproterozoic (?2.05?Ga) mantle plume. As there is no evidence of the 2.05?Ga mantle plume in other areas of southern Siberia, we suggest that the Katugin mineralization occurred on the distant allochtonous terrane, which has been accreted to Siberian Craton later.
DS202007-1143
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.
DS202102-0194
2021
Donskaya, T.V.Gladkochub, D.P., Donskaya, T.V., Pisarevesky, S.A., Salnikova E.B., Mazukabzov, A.M., Kotov, A.B., Motova, Z.I., Stepanova, A.V., Kovach, V.P.Evidence of the latest Paleoproterozoic ( ~1615 Ma) mafic magmatism the southern Siberia: extensional environments in Nuna subcontinent.Precambrian Research, Vol. 354, doi.org/10.1016 /j.precamres. 2020.10049 14p. PdfRussiaCraton - Siberian
DS202202-0201
2022
Donskaya, T.V.Kostrivitsky, S.I., Yakolev, D.A., Sharygin, I.S., Gladkochub, D.P., Donskaya, T.V., Tretiakova, I.G., Dymshits, A.M.Diamondiferous lamproites of Ingashi field, Siberian craton.Geological Society of London Special Publication 513, pp. 45-70.Russialamproites

Abstract: Ingashi lamproite dykes are the only known primary sources of diamond in the Irkutsk district (Russia) and the only non-kimberlitic one in the Siberian craton. The Ingashi lamproite field is situated in the Urik-Iya graben within the Prisayan uplift of the Siberian craton. The phlogopite-olivine lamproites contain olivine, talc, phlogopite, serpentine, chlorite, olivine, garnet, chromite, orthopyroxene, clinopyroxene as well as Sr-F-apatite, monazite, zircon, armolcolite, priderite, potassium Mg-arfvedsonite, Mn-ilmenite, Nb-rutile and diamond. The only ultramafic lamprophyre dyke is composed mainly of serpentinized olivine and phlogopite in the talc-carbonate groundmass and is similar to Ingashi lamproites accessory assemblage with the same major element compositions. Trace element and Sr-Nd isotopic relationships of the Ingashi lamproites are similar to classic lamproites. Different dating methods have provided the ages of lamproites: 1481 Ma (Ar-Ar phlogopite), 1268 Ma (Rb-Sr whole rock) and 300 Ma (U-Pb zircon). Ingashi lamproite ages are controversial and require additional study. The calculated pressure of 3.5 GPamax for clinopyroxenes indicates that lamproite magma originated deeper than 100 km. A Cr-in-garnet barometer shows a 3.7-4.3 GPamin and derivation of Ingashi lamproites deeper than 120 km in depth. Based on the range of typical cratonic geotherms and the presence of diamonds, the Ingashi lamproite magma originated at a depth greater than 155 km.
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.
DS202202-0190
2022
Dora, M.L.Dora, M.L., Randive, K., Meshram, R., Meshram, T., Baswani, S.R., Korakoppa, M., Malviya, V.P.Petrogenesis of a calc-alkaline lamprophyre ( minette) from Thanewasna western Bastar craton, central India: insights from mineral, bulk rock and in-situ trace element geochemistry.Geological Society of London Special Publication 513, pp. 179-207.Indiaminette

Abstract: The lamproites and kimberlites are well known from the Eastern Bastar Craton, Central India. However, a Proterozoic lamprophyre dyke is discussed here, from the Western Bastar Craton (WBC). The field geology, petrographic, mineralogical and whole-rock and in-situ trace element geochemistry of biotite are described to understand the petrogenesis and lithospheric evolution in the WBC. The Thanewasna lamprophyre (TL) is undeformed and unmetamorphosed, intruded into c. 2.5 Ga charnockite and metagabbro but closely associated with c. 1.62 Ga undeformed Mul granite. The TL has a characteristic porphyritic texture, dominated by phenocrysts of biotite, microphenocryst of amphibole, clinopyroxene and a groundmass controlled by feldspar. Mineral chemistry of biotite and amphibole suggest a calc-alkaline (CAL) type, and pyroxene chemistry reveals an orogenic setting. The TL is characterized by high SiO2 and low TiO2, MgO, Ni and Cr, consistent with its subcontinental lithospheric origin. The presence of crustal xenolith and ocelli texture followed by observed variations in Th/Yb, Hf/Sm, La/Nb, Ta/La, Nb/Yb, Ba/Nb indicate substantial crustal contamination. Whole-rock and in-situ biotite analysis by laser ablation inductively coupled plasma mass spectrometry show low concentrations of Ni (30-50 ppm) and Cr (70-150 ppm), pointing to the parental magma evolved nature. Enrichment in H2O, reflected in magmatic mica dominance, combined with high large ion lithophile element, Th/Yb ratios, and striking negative Nb-Ta anomalies in trace element patterns, is consistent with a source that was metasomatized by hydrous fluids corresponding to those generated by subduction-related processes. Significant Zr-Hf and Ti anomalies in the primitive mantle normalized multi-element plots and the rare earth element pattern of the TL, similar to the global CAL average trend, including Eastern Dharwar Craton lamprophyres. Our findings provide substantial petrological and geochemical constraints on petrogenesis and geodynamics. However, the geodynamic trigger that generated CAL magmatism and its role in Cu-Au metallogeny in the WBC, Central India, is presently indistinct in the absence of isotopic studies. Nevertheless, the lamprophyre dyke is emplaced close to the Cu-(Au) deposit at Thanewasna.
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.
DS202104-0590
2021
Dorfman, S.M.Lv, M., Dorfman, S.M., Badro, J., Borensztajin, S., Greenberg, E., Prakapenka, V.B.Reversal of carbonate-silicate cation exchange in cold slabs in Earth's lower mantle. Nature Communications, doi.org/10.10.1038 /s41467-021-21761-9 8p. PdfMantlediamond inclusions

Abstract: The stable forms of carbon in Earth’s deep interior control storage and fluxes of carbon through the planet over geologic time, impacting the surface climate as well as carrying records of geologic processes in the form of diamond inclusions. However, current estimates of the distribution of carbon in Earth’s mantle are uncertain, due in part to limited understanding of the fate of carbonates through subduction, the main mechanism that transports carbon from Earth’s surface to its interior. Oxidized carbon carried by subduction has been found to reside in MgCO3 throughout much of the mantle. Experiments in this study demonstrate that at deep mantle conditions MgCO3 reacts with silicates to form CaCO3. In combination with previous work indicating that CaCO3 is more stable than MgCO3 under reducing conditions of Earth’s lowermost mantle, these observations allow us to predict that the signature of surface carbon reaching Earth’s lowermost mantle may include CaCO3.
DS202104-0614
2021
Dorfman, S.M.Wang, W.,Liu, J., Yang, H., Dorfman, S.M., Lv, M., Li, J., Zhao, J., Hu, M.Y., bi, W., Alp, E.E., Xiao, Y., Wu, Z., Lin, J-F.Iron force constants of bridgmanite at high pressure: implications for iron isotope fractionation in the deep mantle.Geochimica et Cosmochimica Acta, Vol. 294, pp. 215-231. pdfMantlebridgmanite

Abstract: The isotopic compositions of iron in major mantle minerals may record chemical exchange between deep-Earth reservoirs as a result of early differentiation and ongoing plate tectonics processes. Bridgmanite (Bdg), the most abundant mineral in the Earth’s lower mantle, can incorporate not only Al but also Fe with different oxidation states and spin states, which in turn can influence the distribution of Fe isotopes between Bdg and ferropericlase (Fp) and between the lower mantle and the core. In this study, we combined first-principles calculations with high-pressure nuclear resonant inelastic X-ray scattering measurements to evaluate the effects of Fe site occupancy, valence, and spin states at lower-mantle conditions on the reduced Fe partition function ratio (?-factor) of Bdg. Our results show that the spin transition of octahedral-site (B-site) Fe3+ in Bdg under mid-lower-mantle conditions generates a +0.09‰ increase in its ?-factor, which is the most significant effect compared to Fe site occupancy and valence. Fe2+-bearing Bdg varieties have smaller ?-factors relative to Fe3+-bearing varieties, especially those containing B-site Fe3+. Our models suggest that Fe isotopic fractionation between Bdg and Fp is only significant in the lowermost mantle due to the occurrence of low-spin Fe2+ in Fp. Assuming early segregation of an iron core from a deep magma ocean, we find that neither core formation nor magma ocean crystallization would have resulted in resolvable Fe isotope fractionation. In contrast, Fe isotopic fractionation between low-spin Fe3+-bearing Bdg/Fe2+-bearing Fp and metallic iron at the core-mantle boundary may have enriched the lowermost mantle in heavy Fe isotopes by up to +0.20‰.
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 ?13C values varied between ?4.14 and ?3.89‰ while those of ?18O 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
DS202104-0611
2021
Dorofeeva, A.I.Titkov, S.V., Yakovleva, V.V., Breev, I.D., Anisimov, A.N., Baranov, P.G., Dorofeeva, A.I., Bortnikov, N.S.Distribution of nitrogen-vacancy NV centers in cubic diamond crystals from Anabar placers as revealed by ODMR and PL tomography.Doklady Earth Sciences, Vol. 496, 1, pp. 45-47. pdfRussiadeposit - Anabar

Abstract: Nitrogen-vacancy NV- centers, which are of considerable interest for quantum electronics, are artificially produced in the diamond structure by irradiation and subsequent annealing. In this work, these centers were revealed in natural diamonds of cubic habit (type IaA + Ib according to physical classification) from an industrial placer deposit of the Anabar River (NE Siberian platform) using the method of optically detected magnetic resonance (ODMR). Localization of the NV- centers in the dislocations slip planes {111}, separated by distances of about 5 ?m, was established by means of scanning the ODMR and PL signals with a submicron resolution. In various crystals, one or two intersecting systems of such slip planes have been revealed. The largest amounts of these defects were found in the peripheral zones of crystals containing increased amounts of single isomorphic nitrogen atoms in the structure. The data obtained indicate the formation of the NV- centers in natural diamonds under post-crystallization plastic deformation, i.e., by a mechanism that differs from the widely used method of their artificial production.
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 ?18OSMOW and ?18CPDB 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.
DS202104-0601
2021
Doroshkevich, A.G.Prokopyev, I.R., Doroshkevich, A.G., Zhumadilova, D.V., Starikova, A.E., Nugumanova, Ya.N., Vladykin, N.V.Petrogenesis of Zr-Nb ( REE) carbonatites from the Arbarastakh complex ( Aldan Shield, Russia): mineralogy and inclusion data.Ore Geology Reviews, Vol. 131, 104042, 15p. Pdf.Russiadeposit - Arbarastakh

Abstract: The Arbarastakh Neoproterozoic ultramafic carbonatite complex is located in the southwestern part of the Siberian Craton (Aldan Shield) and contains ore-bearing Zr-Nb (REE) carbonatites and phoscorites. Carbonatites are mainly represented by calcite and silicocarbonatite varieties. The primary minerals composing the carbonatites are calcite and dolomite, as well as phlogopite, clinopyroxene, fluorapatite, amphibole, fluorite, K-feldspar and feldspathoids. Olivine (forsterite), Ti-magnetite, apatite, phlogopite, calcite, dolomite and the minor spinel group minerals form the primary phoscorites. The ore-bearing Zr-Nb mineral assemblages of the phoscorites and carbonatites include accessory zircon, zirconolite, perovskite, pyrochlore and baddeleyite. The Ba-Sr-REE hydrothermal mineralisation consists of ancylite-(Ce), bastnaesite-(Ce) and burbankite, as well as barite-celestite, strontianite, barytocalcite, and rare Cu-Fe sulphides. The silicocarbonatites and carbonatites formed in multiple stages from a single alkaline Ca-Na-K-silicocarbonatite melt, while the phoscorites are products of differentiation of the carbonatitic melt and were crystallised from an Fe-rich phosphate-carbonate melt at temperatures of more than 720 °C. The silicate-phosphate-carbonate melts were responsible for the Zr-Nb mineralisation of the carbonatites at temperatures of more than 540-575 °C; the hydrothermal REE-bearing mineral assemblages crystallised from saline (60-70 wt%) carbonatitic fluids of Na-Ca-Mg-F-carbonate composition at a minimum temperature range of 350-300 °C. The Ca-Sr-carbonate as well as the Na-hydro-carbonate fluids were responsible for the Ba-Sr-REE mineralisation of the phoscorites at ~500-480 and 450-430 °C.
DS202106-0972
2021
Doroshkevich, A.G.Sun, J., Zhu, X-K., Belshaw, N.S., Chen, W., Doroshkevich, A.G., Luo, W.J., Song, W.L., Chen, B.B., Cheng, Z.G., Li, Z.H., Wang, Y., Kynicky, J., Henderson, G.M.Ca isotope systematics of carbonatites: insights into carbonatite source and evolution.Geochemical Perspectives Letters, Vol. 17, pp. 11-15. pdfMantlecarbonatites

Abstract: Carbonatite, an unusual carbonate-rich igneous rock, is known to be sourced from the mantle which provides insights into mantle-to-crust carbon transfer. To constrain further the Ca isotopic composition of carbonatites, investigate the behaviour of Ca isotopes during their evolution, and constrain whether recycled carbonates are involved in their source regions, we report ?44/42Ca for 47 worldwide carbonatite and associated silicate rocks using a refined analytical protocol. Our results show that primary carbonatite and associated silicate rocks are rather homogeneous in Ca isotope compositions that are comparable to ?44/42Ca values of basalts, while non-primary carbonatites show detectable ?44/42Ca variations that are correlated to ?13C values. Our finding suggests that Ca isotopes fractionate during late stages of carbonatite evolution, making it a useful tool in the study of carbonatite evolution. The finding also implies that carbonatite is sourced from a mantle source without requiring the involvement of recycled carbonates.
DS202107-1109
2021
Doroshkevich, A.G.Kruk, M.N., Doroshkevich, A.G., Prokopyev, I.R., Izbrodin, I.A.Mineralogy of phoscorites of the Arbarastakh complex, Republic of Sakha, Yakutia, Russia).Minerals MDPI, Vol. 11, 556 24p. PdfRussia, Yakutiacarbonatite

Abstract: The Arbarastakh ultramafic carbonatite complex is located in the southwestern part of the Siberian Craton and contains ore-bearing carbonatites and phoscorites with Zr-Nb-REE mineralization. Based on the modal composition, textural features, and chemical compositions of minerals, the phoscorites from Arbarastakh can be subdivided into two groups: FOS 1 and FOS 2. FOS 1 contains the primary minerals olivine, magnetite with isomorphic Ti impurities, phlogopite replaced by tetraferriphlogopite along the rims, and apatite poorly enriched in REE. Baddeleyite predominates among the accessory minerals in FOS 1. Zirconolite enriched with REE and Nb and pyrochlore are found in smaller quantities. FOS 2 has a similar mineral composition but contains much less olivine, magnetite is enriched in Mg, and the phlogopite is enriched in Ba and Al. Of the accessory minerals, pyrochlore predominates and is enriched in Ta, Th, and U; baddeleyite is subordinate and enriched in Nb. Chemical and textural differences suggest that the phoscorites were formed by the sequential introduction of different portions of the melt. The melt that formed the FOS 1 was enriched in Zr and REE relative to the FOS 2 melt; the melt that formed the FOS 2 was enriched in Al, Ba, Nb, Ta, Th, U, and, to a lesser extent, Sr.
DS202203-0353
2021
Doroshkevich, A.G.Kamenetsky, V.S., Doroshkevich, A.G., Elliott, A.L., Zaitsev, A.N.Carbonatites: contrasting, complex, and controversial.Elements, Vol. 17, pp. 307-314.Mantlemelting

Abstract: Carbonatites are unique, enigmatic, and controversial rocks directly sourced from, or evolved from, mantle melts. Mineral proportions and chemical compositions of carbonatites are highly variable and depend on a wide range of processes: melt generation, liquid immiscibility, fractional crystallization, and post-magmatic alteration. Observations of plutonic carbon-atites and their surrounding metasomatic rocks (fenites) suggest that carbon-atite intrusions and volcanic rocks do not fully represent the true compositions of the parental carbonatite melts and fluids. Carbonatites are enriched in rare elements, such as niobium and rare earths, and may host deposits of these elements. Carbonatites are also important for understanding the carbon cycle and mantle evolution.
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 ?Nd(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 ?Nd (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 ?66Zn (relative to JMC-Lyon-03-0749l)?=?+0.30?±?0.03‰ consistent with the Bulk Silicate Earth estimates of ?66Zn?=?+0.28?±?0.05‰ (Chen et al., 2013). The refractory peridotites have Zn concentrations ranging from 30 to 48 ppm and ?66Zn 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 ?7Li 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 ?7Li (1.8-11.6‰), which we attribute to pre-eruption metasomatism. [Li] in opx is higher than in coexisting olivine while ?7LiOl-Opx (?7LiOl ? ?7LiOpx) 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, ?7Li 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 ?7Li balance between olivine and opx, and bulk rocks. Unaltered ?26Mg 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 ?7Li 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 ?7Li (1.8-11.6‰), which we attribute to pre-eruption metasomatism. [Li] in opx is higher than in coexisting olivine while ?7LiOl-Opx (?7LiOl ? ?7LiOpx) 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, ?7Li 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 ?7Li balance between olivine and opx, and bulk rocks. Unaltered ?26Mg 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.
DS202109-1464
2021
Doucet, L.S.Doucet, L.S., Li, Z-X., El Dien, H.GOceanic and super-deep continental diamond share a transition zone origin and mantle plume transportation.Nature Scientific Reports, Vol. 11, 16958, 11p. Open access https://www.nature .com/articles/s41598- 021-96286-8.pdf Mantlediamond genesis

Abstract: Rare oceanic diamonds are believed to have a mantle transition zone origin like super-deep continental diamonds. However, oceanic diamonds have a homogeneous and organic-like light carbon isotope signature (?13C ? 28 to ? 20‰) instead of the extremely variable organic to lithospheric mantle signature of super-deep continental diamonds (?13C ? 25‰ to?+?3.5‰). Here, we show that with rare exceptions, oceanic diamonds and the isotopically lighter cores of super-deep continental diamonds share a common organic ?13C composition reflecting carbon brought down to the transition zone by subduction, whereas the rims of such super-deep continental diamonds have the same ?13C as peridotitic diamonds from the lithospheric mantle. Like lithospheric continental diamonds, almost all the known occurrences of oceanic diamonds are linked to plume-induced large igneous provinces or ocean islands, suggesting a common connection to mantle plumes. We argue that mantle plumes bring the transition zone diamonds to shallower levels, where only those emplaced at the base of the continental lithosphere might grow rims with lithospheric mantle carbon isotope signatures.
DS202110-1611
2021
Doucet, L.S.Doucet, L.S., Li, Z-X., El Dien, G.H.Oceanic and super-deep continental diamonds share a transition zone origin and mantle plume transportation.Nature Scientfic Reports, Vol. 11, 16958 11p. PdfMantlediamond genesis

Abstract: Rare oceanic diamonds are believed to have a mantle transition zone origin like super-deep continental diamonds. However, oceanic diamonds have a homogeneous and organic-like light carbon isotope signature (?13C ? 28 to ? 20‰) instead of the extremely variable organic to lithospheric mantle signature of super-deep continental diamonds (?13C ? 25‰ to?+?3.5‰). Here, we show that with rare exceptions, oceanic diamonds and the isotopically lighter cores of super-deep continental diamonds share a common organic ?13C composition reflecting carbon brought down to the transition zone by subduction, whereas the rims of such super-deep continental diamonds have the same ?13C as peridotitic diamonds from the lithospheric mantle. Like lithospheric continental diamonds, almost all the known occurrences of oceanic diamonds are linked to plume-induced large igneous provinces or ocean islands, suggesting a common connection to mantle plumes. We argue that mantle plumes bring the transition zone diamonds to shallower levels, where only those emplaced at the base of the continental lithosphere might grow rims with lithospheric mantle carbon isotope signatures.
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.
DS202110-1628
2020
Dowe, J.McManus, C.E., McMillan, N.J., Dowe, J., Bell, J.Diamonds certify themselves: multivariate statistical provenance analysis.Minerals MDPI, Vol. 10, 12p.Blank

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
DS2000-0617
2000
Downes, H.Markwick, A.J.W., Downes, H.Lower crustal granulite xenoliths from the Arkangelsk kimberlite pipes, petrological, geochemical, geophysicsLithos, Vol. 51, No. 1-2, pp. 135-Russia, Kola Peninsula, ArkangelskXenoliths
DS2001-0268
2001
Downes, H.Downes, H.Formation and modification of the shallow sub-continental lithospheric mantle: a reviewJournal of Petrology, Vol. 42, No. 1, Jan. pp. 233-56.EuropeGeochemistry - ultramafic xenolith suites, Massifs
DS2001-0631
2001
Downes, H.Kramm, U., Sindern, S., Downes, H.Timing of magmatism in the Kola alkaline province and the translation of isotope dates - geological processesJournal of South African Earth Sciences, Vol. 32, No. 1, p. A 23 (abs)Russia, Kola Peninsula, Baltic ShieldCarbonatite, Kola
DS2001-0735
2001
Downes, H.Marwick, A.J., Downes, H., Verennikov, N.The lower crust of southeast Belarus: petrological, geophysical and geochemical constraints from xenoliths.Tectonophysics, Vol. 339, No. 1-2, pp. 215-37.RussiaPetrology, Xenoliths
DS2001-1048
2001
Downes, H.Seghedi, I., Downes, H., Pecskay, Thirlwall, Szakacsmagma genesis in a subduction related post collisional volcanic arc segment: the Ukrainian Carpathians.Lithos, Vol. 57, No. 4, July, pp. 237-62.UKraineAlkaline magmatism, Subduction - not specific to diamonds
DS2002-0400
2002
Downes, H.Downes, H., Kostoula, T., Jones, A.P., Beard, A.D., Thirwall, M.F., Bodinier, J.L.Geochemistry and Sr Nd isotopic compositions of mantle xenoliths from the MonteContributions to Mineralogy and Petrology, Vol. 144, 1, Oct. pp. 78-92.ItalyMelilite - carbonatite - not specific to diamonds
DS2002-0401
2002
Downes, H.Downes, H., Marwick, A., Kempton, P.D., Thirwall, M.F.The lower crust beneath cratonic NE Europe isotopic constraints from garnet granulite xenoliths.Terra Nova, Vol. 13, No. 6, pp. 395-400.northeast EuropeGeochronology
DS2002-0402
2002
Downes, H.Downes, H., Peltonen, P., Manttari, I., Sharkov, E.V.Proterozoic zircon ages from lower crust granulite xenoliths, Kola Peninsula, Russia: evidence for crustal growth and reworking.Journal of the Geological Society of London, Vol. 159, 2, pp. 485-488.Russia, Kola PeninsulaBlank
DS2003-0349
2003
Downes, H.Downes, H., Reichow, M.K., Mason, P.R.D., Beard, A.D., Thirlwall, M.F.Mantle domains in the lithosphere beneath the French Massif Central: trace element andChemical Geology, Vol. 200, 1-2, Oct. 16, pp. 71-87.Europe, FranceGeochronology, Peridotites
DS2003-0863
2003
Downes, H.Mahotkin, I.L., Downes, H., Hegner, E., Beard, A.D.Devonian dike swarms of alkaline, carbonatitic and primitiv magma type rocks from the8ikc, Www.venuewest.com/8ikc/program.htm, Session 4, POSTER abstractRussia, Kola PeninsulaMantle geochemistry
DS200412-0446
2004
Downes, H.Dessai, A.G., Markwich, A., Vaselli, O., Downes, H.Granulite and pyroxenite xenoliths from the Deccan Trap: insights into the nature and composition of the lower lithosphere beneaLithos, Vol. 78, 3, Nov. pp. 263-290.IndiaDharwar Craton, crust-mantle transition
DS200412-0476
2004
Downes, H.Downes, H., Beard, A., Hinton, R.Natural experimental charges: an ion microprobe study of trace element distribution coefficients in glass rich hornblendite andLithos, Vol. 75, 1-2, July, pp. 1-17.Europe, Germany, IsraelMagmatism, alkaline, igneous glasses, basanite. foidite
DS200412-0477
2004
Downes, H.Downes, H., Macdonald, R., Upton, B.G.J., Cox, K.G., Bodinier, J-L., Mason, P.R.D., James, D., Hill, P.G., HeaUltramafic xenoliths from the Bearpaw Mountains, Montana: USA: evidence for multiple metasomatic events in the lithospheric mantJournal of Petrology, Vol. 45, 8, pp. 1631-1662.United States, MontanaMetasomatism
DS200412-0478
2002
Downes, H.Downes, H., Peltonen, P., Manttari, I., Sharkov, E.V.Proterozoic zircon ages from lower crust granulite xenoliths, Kola Peninsula, Russia: evidence for crustal growth and reworking.Journal of the Geological Society, Vol. 159, 2, pp. 485-488.Russia, Kola PeninsulaGeochronology
DS200412-0479
2003
Downes, H.Downes, H., Reichow, M.K., Mason, P.R.D., Beard, A.D., Thirlwall, M.F.Mantle domains in the lithosphere beneath the French Massif Central: trace element and isotopic evidence from mantle clinopyroxeChemical Geology, Vol. 200, 1-2, Oct. 16, pp. 71-87.Europe, FranceGeochronology, peridotites
DS200512-0111
2003
Downes, H.Brassinnes, S., DeMaiffe, D., Balaganskaya, E., Downes, H.New mineralogical and geochemical dat a on the Vuorijarvi ultramafic, alkaline and carbonatitic complex ( Kola Region, NW Russia).Periodico di Mineralogia, (in english), Vol. LXX11, 1. April, pp. 79-86.Russia, Kola PeninsulaMelilite
DS200512-0200
2004
Downes, H.Cvetkovic, V., Downes, H., Prelevic, D., Jovanovic, M.Characteristics of the lithospheric mantle beneath East Serbia inferred from ultramafic xenoliths in Paleogene basanites.Contributions to Mineralogy and Petrology, Vol. 148, 3, pp. 335-357.Europe, SerbiaBasanites, Foidites
DS200512-0247
2005
Downes, H.Downes, H., Balaganskaya, E., Beard, A., Liferovich, R., Demaiffe, D.Petrogenetic processes in the ultramafic, alkaline and carbonatitic magmatism in the Kola alkaline province: a review.Lithos, Advanced in press,Russia, Kola PeninsulaCarbonatite, kimberlites
DS200512-0872
2005
Downes, H.Prelevic, D., Foley, S.F., Romer, R.L., Cvetkovic, V., Downes, H.Tertiary ultrapotassic volcanism in Serbia: constraints on petrogenesis and mantle source characteristics.Journal of Petrology, Vol. 46, 7, July pp. 1443-1487.Europe, SerbiaVolcanism
DS200612-0103
2006
Downes, H.Beard, A.D., Downes, H., Mason, P.R.D., Vetrin, V.R.Depletion and enrichment processes in the lithospheric mantle beneath the Kola Peninsula (Russia): evidence from spinel lherzolite wehrlite xenoliths.Lithos, in pressRussia, Kola PeninsulaMetasomatism, Kandalaksha
DS200612-0348
2005
Downes, H.Downes, H., Balaganskaya, E., Beard, A., Liferovich, R., Demaiffe, D.Petrogenetic processes in the ultramafic, alkaline and carbonatitic magmatism in the Kola alkaline province: a review.Lithos, Vol. 85, 1-4, Nov-Dec. pp. 48-75.Russia, Kola PeninsulaCarbonatite
DS200612-0349
2006
Downes, H.Downes, H., Cvetkovic, V., Hock, V., Prelevic, D., Lazarov, M.Refertilization of highly depleted lithospheric mantle ( Balkan Peninsula, SE Europe): evidence from peridotite xenoliths.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.EuropeGeochemistry
DS200612-1540
2006
Downes, H.Wittig, N., Baker, J.A., Downes, H.Dating the mantle roots of young continental crust.Geology, Vol.34, 4, April pp. 237-240.Europe, French Massif CentralGeochronology, xenoliths, Variscan Orogeny
DS200712-0059
2007
Downes, H.Beard, A.D., Downes, H., Mason, P.R., Vetrin, V.R.Depletion and enrichment processes in the lithospheric mantle beneath the Kola Peninsula ( Russia): evidence from spinel lherzolite and wehrlite xenoliths.Lithos, Vol. 94, 1-4, pp. 1-24.RussiaXenoliths
DS200712-0211
2007
Downes, H.Cvetkovi, V., Lazarov, M., Downes, H., Prevelvi, D.Modification of the subcontinental mantle beneath East Serbia: evidence from orthopyroxene rich xenoliths.Lithos, Vol. 92, 1-4, pp. 90-110.EuropeXenoliths - not specific to diamonds
DS200712-0273
2007
Downes, H.Downes, H.Origin and significance of spinel and garnet pyroxenites in the shallow lithospheric mantle: ultramafic massifs in orogenic belts in West EuropeLithos, Vol. 99, 1-2, pp. 1-24.Europe, AfricaPetrology
DS200712-1162
2006
Downes, H.Wilson, M., Downes, H.Tertiary Quaternary intra plate magmatism in Europe and its relationship to mantle dynamics.Geological Society of London Memoir, No. 32, pp. 147-166.EuropeMagmatism
DS200812-0296
2007
Downes, H.Downes, H., Mahotkin, I.I., Beard, A.D., Hegner, E.Petrogenesis of alkali silicate, carbonatitic and kimberlitic magmas of the Kola alkaline carbonatite province.Vladykin Volume 2007, pp. 45-56.Russia, Kola PeninsulaCarbonatite
DS200912-0122
2009
Downes, H.Coltorti, M., Downes, H., Gregoire, M., O'Reilly, S.Y., Beccaluva, L., Bonadiman, Piccardo.Rivalenti, SienaPetrological evolution of the European lithospheric mantle: from Archean to present day.Journal of Petrology, Vol. 50, no. 7, pp. 1181-1184.MantleMagmatism
DS200912-0168
2009
Downes, H.Dessai, A.G., Peinado, M., Gokam, S.G., Downes, H.Structure of the deep crust beneath the Central Indian Tectonic Zone: an integration of geophysical and xenolith data.Gondwana Research, Vol. 17, 1., pp. 162-170.IndiaTectonics
DS200912-0209
2009
Downes, H.Facer, J., Downes, H., Beard, A.In situ serpentinization and hydrous fluid metasomatism in spinel dunite xenoliths from the Bearpaw Mountains, Montana, USA.Journal of Petrology, Vol. 50, 8, pp. 1443-1475.United States, MontanaMetasomatism - not specific to diamonds
DS200912-0409
2009
Downes, H.Koreshkova, M., Downes, H., Levsky, L.Geochemistry and petrology of lower crustal xenoliths from Udachnaya and Komsomolskaya kimberlite pipes, Siberia.Goldschmidt Conference 2009, p. A683 Abstract.Russia, SiberiaDeposit - Udachnaya
DS200912-0410
2009
Downes, H.Koreshkova, M.Y., Downes, H., Nikitina, L.P., Vladykin, N.V., Larionov, A.N., Sergeev, S.A.Trace element and age characteristics of zircons in granulite xenoliths from the Udachnaya pipe, Siberia.Precambrian Research, Vol. 168, 3-4, pp. 197-212.Russia, YakutiaGeochronology
DS200912-0821
2009
Downes, H.Wittig, N., Pearson, D.G., Downes, H., Baker, J.A.The U, Th and Pb elemental and isotope compositions of mantle clinopyroxenes and their grain boundary contamination derived from leaching and digestion experiments.Geochimica et Cosmochimica Acta, Vol. 73, 2, pp. 469-488.MantleGeochronology
DS201012-0114
2010
Downes, H.Coltori, M., Downes, H., Gregoire, M., O'Reilly, S.Y.Petrological evolution of the European lithospheric mantle: introduction.Geological Society of London Special Publication, No. 337, pp. 1-5.EuropeMantle petrology
DS201012-0152
2010
Downes, H.Dessai, A.G., Peinado, M., Gokarn, S.G., Downes, H.Structure of the deep crust beneath the Central Indian Tectonic Zone: an integration of geophysical dat a and xenolith dat a.Gondwana Research, Vol. 17, pp. 162-170.IndiaGeothermometry
DS201012-0533
2010
Downes, H.Nedli, Z., Toth, T.M., Downes, H., Csaszar, G., Beard, A., Szabo, C.Petrology and geodynamical interpretation of mantle xenoliths from Late Cretaceous lamprophyres Villany Mts. Hungary.Tectonophysics, Vol. 488, 1-4, pp. 43-54.Europe, HungaryLamprophyre
DS201012-0726
2010
Downes, H.Smith, B., Downes, H.Trace element distribution in carbonatites from Vuorijarvi ( Kola Peninsula) Russia.International Mineralogical Association meeting August Budapest, abstract p. 554.Russia, Kola PeninsulaAlkalic
DS201112-0034
2011
Downes, H.Ashchepkov, I.V., Andre, L., Downes, H., Belyatsky, B.A.Pyroxenites and megacrysts from Vitim picrite basalts ( Russia): polybaric fractionation of rising melts in the mantle?Journal of Asian Earth Sciences, Vol. 42, 1-2, pp. 14-37.RussiaPicrite
DS201112-0035
2011
Downes, H.Ashchepkov, I.V., Downes, H., Vladykin, N.V., Mitchell, R., Nigmatulina, E., Palessky, S.V.Reconstruction of mantle sequences beneath the Wyoming craton using xenocrysts from Sloan and Kelsey Lake -1 kimberlite pipes, northern Colorado.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., pp. 213-233.United States, Colorado PlateauPyrope compositions -geothermobarometry
DS201112-0036
2011
Downes, H.Ashchepkov, I.V., Ionov, D.A., Ntaflos, T., Downes, H., Palessky, S.V.Origin of craton mantle layering according to PT reconstruction.Goldschmidt Conference 2011, abstract p.459.Russia, YakutiaKimberlite
DS201112-0198
2010
Downes, H.Coltori, M., Downes, H., Gregoirue, M., O'Reilly, S.Y.,editorsPetrological evolution of the European lithospheric mantle.Geological Society of London, Special Publ., 337, 246p.MantleBook - review
DS201112-0274
2011
Downes, H.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
DS201112-0540
2011
Downes, H.Koreshkova, M.Yu., Downes, H., Levsky, L.K., Vladykin, N.V.Petrology and geochemistry of granulite xenoliths from Udachnaya and Komosomolskaya kimberlite pipes, Siberia.Journal of Petrology, Vol. 52, 10, pp. 1857-1885.Russia, SiberiaDeposit - Udachnaya, Komosmolskaya
DS201112-0541
2011
Downes, H.Koreshkova, M.Yu., Downes, H., Levsky, L.K., Vladykin, N.V.Petrology and geochemistry of granulite xenoliths from Udachnaya and Komosomskaya kimberlite pipes, Siberia.Journal of Petrology, Vol. 52, no. 10, pp. 1857-1885.Russia, SiberiaDeposit - Udachnaya, Komosmskaya
DS201112-0542
2011
Downes, H.Koreshkova, M.Yu., Downes, H., Levsky, L.K., Vladykin, N.V.Petrology and geochemistry of granulite xenoliths from Udachnaya and Komosomolskaya kimberlite pipes, Siberia.Journal of Petrology, Vol. 52, 10, pp. 1857-1885.Russia, SiberiaDeposit - Udachnaya, Komosomolskaya
DS201212-0027
2012
Downes, H.Ashchepkov, Downes, H., Mitchell, R.H., Vladykin, N.V., Palessky, S.V.Mantle lithosphere beneath Wyomng is based on Sloan and Kelsy Lake - 1 kimberlite xenocrysts.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractUnited States, Wyoming, Colorado PlateauDeposit - Sloan, Kelsey Lake
DS201212-0036
2013
Downes, H.Ashchepkov, I.V., Vladykin, N.V., Ntaflos, T., Downes, H., Mitchell, R., Smelov, A.P., Alymova, N.V., Kostrovitsky, S.I., Rotman, A.Ya., Smarov, G.P., Makovchuk, I.V., Stegnitsky, Yu.B., Nigmatulina, E.N., Khmehnikova, O.S.Regularities and mechanism of formation of the mantle lithosphere structure beneath the Siberian Craton in comparison with other cratons.Gondwana Research, Vol. 23, 1, pp. 4-24.Russia, SiberiaKimberlite pipes
DS201212-0170
2012
Downes, H.Downes, H., Wall, F., Demeny, A., Szabo, C.S.Continuing the carbonatite controversy.Mineralogical Magazine, Vol. 76, 2, pp. 255-257.TechnologyCarbonatite, brief overview
DS201212-0373
2012
Downes, H.Koreshkova, M.Yu., Downes, H., Rodionov, N.V., Antonov, A.V., Glebovitski, V.A., Sergeev, S.A., Schukina, E.V.Trace element and age characteristics of zircons in lower crustal xenoliths from the Grib kimberlite pipe, Arkhangelsk province, Russia.emc2012 @ uni-frankfurt.de, 1p. AbstractRussia, Archangel, Kola PeninsulaDeposit - Grib
DS201312-0035
2013
Downes, H.Ashchepkov, I.V., Downes, H., Mitchell, R.H., Vladykin, N.V., Coopersmith, H., Palessky, S.V.Wyoming craton mantle lithosphere: reconstructions based on xenocrysts from Sloan and Kelsey Lake kimberlites.Proceedings of the 10th. International Kimberlite Conference, Vol. 1, Special Issue of the Journal of the Geological Society of India,, Vol. 1, pp. 13-27.United States, Colorado PlateauDeposit - Sloan, Kelsey Lake
DS201412-0021
2014
Downes, H.Ashchepkov, I.V., Alymova, N.V., Lognova, A.M., Vladykin, N.V., Kuligin, S.S., Lityukhin, S.I., Downes, H., Stegnitsky, Yu.B., Prokopiev, S.A., Salikhov, R.F., Palessky, V.S., Khmelnikova, O.S.Picroilmenites in Yakutian kimberlites: variations and genetic models.Solid Earth, Vol. 5, pp. 915-938.Russia, YakutiaKimberlite genesis
DS201412-0022
2014
Downes, H.Ashchepkov, I.V., Vladykin, N.N., Ntaflos, T., Kostrovitsky, S.I., Prokopiev, S.A., Downes, H., Smelov, A.P., Agashev, A.M., Logvinova, A.M., Kuligin, S.S., Tychkov, N.S., Salikhov, R.F., Stegnitsky, Yu.B., Alymova, N.V., Vavilov, M.A., Minin, V.A., BabusLayering of the lithospheric mantle beneath the Siberian Craton: modeling using thermobarometry of mantle xenolith and xenocrysts. Tectonophysics, Vol. 634, 5, pp. 55-75.Russia, YakutiaDaldyn, Alakit, Malo-Botuobinsky fields
DS201412-0472
2014
Downes, H.Koreshkova, M.Yu., Downes, H., Glebovitsky, V.A., Rodionov, N.V., Antonov, A.V., Sergeev, S.A.Zircon trace element characteristics and ages in granulite xenoliths: a key to understanding the age and origin of the lower crust, Arkhangelsk kimberlite province, Russia.Contributions to Mineralogy and Petrology, Vol. 167, pp. 973-980.Russia, Archangel, Kola PeninsulaDeposit - Grib
DS201510-1758
2015
Downes, H.Ashchepkov, I.V., Logvinova, A.M., Reimers, L.F., Ntaflos, T., Spetisus, Z.V., Vladykin, N.V., Downes, H., Yudin, D.S., Travin, A.V., Makovchuk, I.V., Palesskiy, V.S., KhmelNikova, O.S.The Sytykanskaya kimberlite pipe: evidence from deep seated xenoliths and xenocrysts for the evolution of the mantle beneath Alakit, Yakutia, Russia.Geoscience Frontiers, Vol. 6, 5, pp. 687-714.Russia, YakutiaDeposit - Sytykanskaya

Abstract: Mantle xenoliths (>150) and concentrates from late autolithic breccia and porphyritic kimberlite from the Sytykanskaya pipe of the Alakit field (Yakutia) were analyzed by EPMA and LAM ICP methods. In P-T-X-f(O2) diagrams minerals from xenoliths show widest variations, the trends P-Fe#-CaO, f(O2) for minerals from porphyric kimberlites are more stepped than for xenocrysts from breccia. Ilmenite PTX points mark moving for protokimberlites from the lithosphere base (7.5 GPa) to pyroxenite lens (5-3.5 GPa) accompanied by Cr increase by AFC and creation of two trends P-Fe#Ol ?10-12% and 13-15%. The Opx-Gar-based mantle geotherm in Alakit field is close to 35 mW/m2 at 65 GPa and 600 °C near Moho was determined. The oxidation state for the megacrystalline ilmenites is lower for the metasomatic associations due to reduction of protokimberlites on peridotites than for uncontaminated varieties at the lithosphere base. Highly inclined linear REE patterns with deep HFSE troughs for the parental melts of clinopyroxene and garnet xenocrysts from breccia were influenced by differentiated protokimberlite. Melts for metasomatic xenoliths reveal less inclined slopes without deep troughs in spider diagrams. Garnets reveal S-shaped REE patterns. The clinopyroxenes from graphite bearing Cr-websterites show inclined and inflected in Gd spectrums with LREE variations due to AFC differentiation. Melts for garnets display less inclined patterns and Ba-Sr troughs but enrichment in Nb-Ta-U. The 40Ar/39Ar ages for micas from the Alakit mantle xenoliths for disseminated phlogopites reveal Proterozoic (1154 Ma) age of metasomatism in early Rodinia mantle. Veined glimmerites with richterite - like amphiboles mark ?1015 Ma plume event in Rodinia mantle. The ?600-550 Ma stage manifests final Rodinia break-up. The last 385 Ma metasomatism is protokimberlite-related.
DS201612-2276
2016
Downes, H.Ashchepkov, I.V., Ntaflos, T., Spetius, Z.V., Salikhov, R.F., Downes, H.Interaction between protokimberlite melts and mantle lithosphere: evidence from mantle xenoliths from the Dalnyaya kimberlite pipe, Yakutia, Russia.Geoscience Frontiers, in press availableRussia, YakutiaDeposit - Dalnyaya

Abstract: The Dalnyaya kimberlite pipe (Yakutia, Russia) contains mantle peridotite xenoliths (mostly lherzolites and harzburgites) that show both sheared porphyroclastic (deformed) and coarse granular textures, together with ilmenite and clinopyroxene megacrysts. Deformed peridotites contain high-temperature Fe-rich clinopyroxenes, sometimes associated with picroilmenites, which are products of interaction of the lithospheric mantle with protokimberlite related melts. The orthopyroxene-derived geotherm for the lithospheric mantle beneath Dalnyaya is stepped similar to that beneath the Udachnaya pipe. Coarse granular xenoliths fall on a geotherm of 35 mWm?2 whereas deformed varieties yield a 45 mWm?2 geotherm in the 2-7.5 GPa pressure interval. The chemistry of the constituent minerals including garnet, olivine and clinopyroxene shows trends of increasing Fe# (=Fe/(Fe + Mg)) with decreasing pressure. This may suggest that the interaction with fractionating protokimberlite melts occurred at different levels. Two major mantle lithologies are distinguished by the trace element patterns of their constituent minerals, determined by LA-ICP-MS. Orthopyroxenes, some clinopyroxenes and rare garnets are depleted in Ba, Sr, HFSE and MREE and represent relic lithospheric mantle. Re-fertilized garnet and clinopyroxene are more enriched. The distribution of trace elements between garnet and clinopyroxene shows that the garnets dissolved primary orthopyroxene and clinopyroxene. Later high temperature clinopyroxenes related to the protokimberlite melts partially dissolved these garnets. Olivines show decreases in Ni and increases in Al, Ca and Ti from Mg-rich varieties to the more Fe-rich, deformed and refertilized ones. Minerals showing higher Fe# (0.11-0.15) are found within intergrowths of low-Cr ilmenite-clinopyroxene-garnet related to the crystallization of protokimberlite melts in feeder channels. In P-f(O2) diagrams, garnets and Cr-rich clinopyroxenes indicate reduced conditions at the base of the lithosphere at ?5 log units below a FMQ buffer. However, Cr-poor clinopyroxenes, together with ilmenite and some Fe-Ca-rich garnets, demonstrate a more oxidized trend in the lower part of lithosphere at ?2 to 0 log units relative to FMQ. Clinopyroxenes from xenoliths in most cases show conditions transitional between those determined for garnets and megacrystalline Cr-poor suite. The relatively low diamond grade of Dalnyaya kimberlites is explained by a high degree of interaction with the oxidized protokimberlite melts, which is greater at the base of the lithosphere.
DS201705-0808
2017
Downes, H.Ashchepkov, I., Ntaflos, T., Logvinova, A., Vladykin, N., Ivanov, A., Spetsius, Z., Stegnitsky, Y., Kostrovitsky, S., Salikhov, R., Makovchuk, I., Shmarov, G., Karpenko, M., Downes, H., Madvedev, N.Evolution of the mantle sections beneath the kimberlite pipes example of Yakutia.European Geosciences Union General Assembly 2017, Vienna April 23-28, 1p. 6337 AbstractRussia, YakutiaDeposit - Sytykanskaya, Dalnyaya, Aykhal, Zarya, Komosomolskaya, Zarnitsa, Udachnaya

Abstract: The PTX diagrams for the separate phases in Sytykanskaya (Ashchepkov et al., 2016) Dalnyaya (Ashchepkov et al., 2017), pipes shows that the PK show the relatively simple P-X trends and geotherms and shows more contrast and simple layering. The PK contain most abundant material from the root of the magma generation they are dunitic veins as the magma feeders represented by the megacrysts. New results for the Aykhal, Zarya and Komsomolskaya pipes in Alake field and Zarnitsa and Udachnaya pipes in Daldyn field show that evolution is accompanied by the developing of metasomatites and branching and veining of the wall rock peridotites . In Aykhal pipe in PK the Gar- dunites prevail, the xenoliths from the dark ABK "Rebus" contain Cr-Ti - rich garnets and ilmenites, more abundant compared with the grey carbonited breccia Nearly the same features were found for Yubileinaya pipe. The example of Komsomolskya pipes show that the ABK contain more eclogitic xenolith than PK. The developing of the magma channel shown in satellite Chukukskaya and Structurnaya pipe was followed by the separation of some parts of the magmatic feeders and crystallization of abundant Gar megacrysts near o the walls blocking the peridotites from the magma feeder. This drastically decrease diamond grade of pipes. Such blocking seems to be the common features for the latest breccias. In Zarnitsa pipe, the dark PK and ABK also contain fresh xenoliths but not only dunites but also sheared and metasomatic varieties and eclogites. Most of dark ABK in Yakutia contain the intergrowth of ilmenites with brown Ti- Cpx showing joint evolution trends. The late breccia contains completely altered peridotite xenoliths mainly of dunite- harzburgite type. The comparison of the trace elements of the coexisting minerals in megacryst show that they were derived from the protokimberlites but are not in complete equilibrium as well as other megacrystalline phases. Ilmenites show inflections of the trace element patterns of most Ilmenites but more regular for the Cpx and Garnets revealing the sub parallel patterns elevating LREE with the rising TRE. But commonly these are not continuous sequances because they developed in the pulsing moving systems like beneath Zarnitsa. The minerals from the feeders like dunites also show the inflected or S-type REE patterns. From the earlier to later phases the TRE compositions became more evolved reflecting the evolution of protokimberlites. The wall rocks also often show the interaction with the more evolved melts and sometimes "cut" spectrums due to the dissolution some phases and repeated melting events So we could suggest the joint evolution of the mantle column protokimberlites and megacrysts composition and type of kimberlites with the diamond grade. The mantle lithospheric base captured by the PK. The developing and rising protokimbelrites was followed by the crystallization of the diamonds in the gradient in FO2 zone in wall rocks due to reductions of C -bearing fluids and carbonatites (> 1 QMF) on peridotites ((< -2 -5 QMF). The most intensive reactions are near the graphite - diamond boundary where protokimberlites are breaking and where most framesites are forming.
DS201801-0030
2017
Downes, H.Koreshkova, M., Downes, H., Millar, I., Levsky, L., Larionov, A., Sergeev, S.Geochronology of metamorphic events in the lower crust beneath NW Russia: a xenolith Hf isotope study.Journal of Petrology, Vol. 58, 8, pp. 1567-1589.Russia, Kola Peninsulageochronology

Abstract: Hf isotope data for zircons and whole-rocks from lower crustal mafic granulite and pyroxenite xenoliths from NW Russia are presented together with the results of U-Pb zircon dating, Sm-Nd and Rb-Sr isotopic compositions of bulk-rocks and minerals, and trace element compositions of minerals. Most zircons preserve a record of only the youngest metamorphic events, but a few Grt-granulite xenoliths retain Archean magmatic zircons from their protolith. Metamorphic zircons have highly variable ?Hf(t) values from -25 to -4. The least radiogenic zircons were formed by recrystallization of primary magmatic Archean zircons. Zircons with the most radiogenic ?Hf grew before garnet or were contemporaneous with its formation. Zircons with ?Hf(t) from -15 to -9 formed by various mechanisms, including recrystallization of pre-existing metamorphic zircons, subsolidus growth in the presence of garnet and exsolution from rutile. They inherited their Hf isotopic composition from clinopyroxene, pargasite, rutile and earlier-formed zircon that had equilibrated with garnet. Subsolidus zircons were formed in response to a major change in mineral association (i.e. garnet- and zircon-producing reactions including partial melting). Recrystallized zircons date the onset of high-temperature conditions without a major change in mineral association. Age data for metamorphic zircons fall into five groups: >1•91 Ga, 1•81-1•86 Ga, 1•74-1•77 Ga, 1•64-1•67 Ga and <1•6 Ga. Most ages correlate with metamorphic events in the regional upper crust superimposed onto rocks of the Belomorian belt during formation of the Lapland Granulite Belt. Zircon formation and resetting at 1•64-1•67 Ga significantly postdates Lapland-Kola orogenic events and may relate to the onset of Mesoproterozoic rifting. The youngest ages (1•6-1•3 Ga) correspond to an event that affected only a few grains in some samples and can be explained by interaction with a localized fluid. The observed garnet-granulite associations were formed at 1•83 Ga in Arkhangelsk xenoliths and 1•74-1•76 Ga in most Kola xenoliths. By the end of the Lapland-Kola orogeny, the rocks were already assembled in the lower crust. However, no addition of juvenile material has been detected and preservation of pre-Lapland-Kola metamorphic zircon indicates that some xenoliths represent an older lower crust. Granulites, pyroxenites and Phl-rich rocks have a common metamorphic history since at least c. 1•75 Ga. At about 1•64 Ga metasomatic introduction of phlogopite took place; however, this was only one of several phlogopite-forming events in the lower crust.
DS201802-0247
2017
Downes, H.Koreshkova, M., Downes, H., Millar, I., Levsky, L., Larianov, A.Geochronology of metamorphic events in the lower crust of NW Russia: a xenolith Hf isotope study.Journal of Petrology, Vol. 58, 8, pp. 1567-1589.Russia, Kola Peninsulageochronology

Abstract: Hf isotope data for zircons and whole-rocks from lower crustal mafic granulite and pyroxenite xenoliths from NW Russia are presented together with the results of U-Pb zircon dating, Sm-Nd and Rb-Sr isotopic compositions of bulk-rocks and minerals, and trace element compositions of minerals. Most zircons preserve a record of only the youngest metamorphic events, but a few Grt-granulite xenoliths retain Archean magmatic zircons from their protolith. Metamorphic zircons have highly variable ?Hf(t) values from -25 to -4. The least radiogenic zircons were formed by recrystallization of primary magmatic Archean zircons. Zircons with the most radiogenic ?Hf grew before garnet or were contemporaneous with its formation. Zircons with ?Hf(t) from -15 to -9 formed by various mechanisms, including recrystallization of pre-existing metamorphic zircons, subsolidus growth in the presence of garnet and exsolution from rutile. They inherited their Hf isotopic composition from clinopyroxene, pargasite, rutile and earlier-formed zircon that had equilibrated with garnet. Subsolidus zircons were formed in response to a major change in mineral association (i.e. garnet- and zircon-producing reactions including partial melting). Recrystallized zircons date the onset of high-temperature conditions without a major change in mineral association. Age data for metamorphic zircons fall into five groups: >1•91 Ga, 1•81-1•86 Ga, 1•74-1•77 Ga, 1•64-1•67 Ga and <1•6 Ga. Most ages correlate with metamorphic events in the regional upper crust superimposed onto rocks of the Belomorian belt during formation of the Lapland Granulite Belt. Zircon formation and resetting at 1•64-1•67 Ga significantly postdates Lapland-Kola orogenic events and may relate to the onset of Mesoproterozoic rifting. The youngest ages (1•6-1•3 Ga) correspond to an event that affected only a few grains in some samples and can be explained by interaction with a localized fluid. The observed garnet-granulite associations were formed at 1•83 Ga in Arkhangelsk xenoliths and 1•74-1•76 Ga in most Kola xenoliths. By the end of the Lapland-Kola orogeny, the rocks were already assembled in the lower crust. However, no addition of juvenile material has been detected and preservation of pre-Lapland-Kola metamorphic zircon indicates that some xenoliths represent an older lower crust. Granulites, pyroxenites and Phl-rich rocks have a common metamorphic history since at least c. 1•75 Ga. At about 1•64 Ga metasomatic introduction of phlogopite took place; however, this was only one of several phlogopite-forming events in the lower crust.
DS201803-0433
2017
Downes, H.Ashchepekov, I.V., Ntaflos, T., Logvinova, A.M., Spetius, Z.V., Downes, H.Monomineral universal clinopyroxene and garnet barometers for peridotitic, eclogitic and basaltic systems.Geoscience Frontiers, Vol. 8, pp. 775-795.Mantlegeobarometry

Abstract: New versions of the universal Jd-Di exchange clinopyroxene barometer for peridotites, pyroxenites and eclogites, and also garnet barometer for eclogites and peridotites were developed. They were checked using large experimental data sets for eclogitic (?530) and peridotitic systems (>650). The precision of the universal Cpx barometer for peridotites based on Jd-Di exchange is close to Cr-Tschermakite method produced by Nimis and Taylor (2000). Cpx barometer was transformed by the substitution of major multiplier for KD by the equations dependent from Al-Na-Fe. Obtained equation in combination with the thermometer of Nimis and Taylor (2000) allow to reconstruct position of the magma feeder systems of the alkali basaltic magma within the mantle diapirs in modern platforms like in Vitim plateau and other Southern Siberia localities and several localities worldwide showing good agreement of pressure ranges for black and green suites. These equations allow construct PTX diagrams for the kimberlite localities in Siberia and worldwide calculating simultaneously the PT parameters for different groups of mantle rocks. They give very good results for the concentrates from kimberlite lamproites and placers with mantle minerals. They are useful for PT estimates for diamond inclusions. The positions of eclogite groups in mantle sections are similar to those determined with new Gar–Cpx barometer produced by C. Beyer et al. (2015). The Fe rich eclogites commonly trace the boundary between the lower upper parts of subcontinental lithospheric mantle (SCLM) at 3–4 GPa marking pyroxenite eclogites layer. Ca-rich eclogites and especially grospydites in SCLM beneath Precambrian kimberlites occurs near pyroxenite layer but in younger mantle sections they became common in the lower parts. The diamondiferous Mg Cr-less group eclogites referring to the ancient island arc complexes are also common in the middle part of mantle sections and near 5–6 GPa. Commonly eclogites in lower apart of mantle sections are remelted and trace the high temperature convective branch. The Mg- and Fe-rich pyroxenites also show the extending in pressure trends which suggest the anatexic melting under the influence of volatiles or under the interaction with plums.
DS201911-2569
2019
Downes, H.Tabor, B.E., Downes, H.Textures of mantle peridotite rocks revisited.Lithos, Vol. 348-349. 13p. PdfMantleperidotite

Abstract: Characterisation of textures in mantle peridotites has long been a subjective method, lacking precise definition or quantification. In a continuing effort to quantify textures found in mantle peridotites, we have analysed thin-sections of a wide variety of spinel and garnet peridotite xenoliths from a range of locations, using a grain-section skeleton outline method. Peridotites from ultramafic massifs have also been analysed using the same methodology. The results for all these samples lie on the same linear trend in a plot of grain-section area vs standard deviation as seen in our previous study. This confirms the utility of the quantitative method, which provides observer-independent objective numerical descriptions of textures in peridotites. In addition, two spinel peridotite xenoliths have been disaggregated using an Electric discharge disaggregation technique and were sieved to produce a grain size distribution. SEM imaging has also been used to show that the 3-D shapes of grains of the constituent minerals have concave features. Computed Tomography (CT)-scanning of separated grains and peridotite rock cores has confirmed the concave features of the constituent minerals and their consequent interlocking structures. A ‘perimeter-area’ relation technique has been used to show that the two-dimensional grain-section skeleton outlines clearly display self-similarity (i.e. fractal characteristics). Images of thin-sections were compared with known Euclidian and fractal images; both the thin-section images and the known fractal images yielded fractal dimensions, whereas the Euclidian images did not. The self-similar or fractal nature of textures of mantle peridotite rocks has also been demonstrated by using Box counting, an alternative method for fractal assessment.
DS202007-1124
2020
Downes, H.Ashchepkov, I.V., Vladykin, N.V., Kalashnyk, H.A., Medvedev, N.S., Saprykin, A.I., Downes, H., Khmelnikova, O.S.Incompatible element enriched mantle lithosphere beneath kimberlitic pipes in Priazovie Ukrainian shield: volatile enriched focused melt flow and connection to mature crust?International Geology Review, in press available 24p. PdfEurope, Ukrainedeposit - Priazovie

Abstract: Major, minor and trace element compositions of mantle xenocrysts from Devonian kimberlite pipes in the Priazovie give an insight into the mantle structure beneath the SE Ukranian Shield and its evolution. Garnets yield low temperature conditions as determined by monomineral thermobarometry. The mantle lithosphere is sharply divided at 4.2 GPa, marked by a high temperature Cpx-Ilm-Phl trend, eclogites and changes in pyrope geochemistry. Seven layers are detected: Ist layer at 2.5-1 GPa is enriched mantle (Fe#Ol ~ 0.11 ? 0.14) with Gar- pyroxenites and Sp peridotites; IInd at 2.5-3.2 GPa - Gar-Sp (Fe#Ol 0.08 ? 0.10) peridotite. IIId at 4.3-3.2 GPa is formed of Archaean- Proterozoic peridotites with Fe#Ol ~0.07 ? 0.095. IVth at 3.2-5 GPa- contains pyroxenitic Gar with higher Ca, eclogites, Chr and Cpx (Fe#Ol ~0.10 ? 0.125); Vth at 5.8 ? 5 GPa is marked by sub-Ca garnets, Cr-rich chromites and Mg-Cr ilmenites; VIth layer at 5.8-6.8 GPa contains Fe-enriched pyropes, almandines and Cr-Mg ilmenites near the lithosphere base; VIIth layer > 6.8 GPa consists of ‘hot’ Fe-rich garnets. Garnets show increasing enrichment in LREE, LILE, Hf, Zr with decreasing pressure. Primitive garnets have round REE patterns; depleted ones have S-type patterns inflected at Nd. Garnets from 6.5 to 3 GPa show increasing La/Ybn, Zr-Hf, LILE. Peridotitic clinopyroxenes have inclined linear trace element patterns rounded from La to Pr with high LILE and HFSE levels. The Fe-rich group (reacted with eclogites) shows bell-shaped irregular patterns with LILE close to the LREE levels. A possible reason for LILE (HFSE and) enrichment of the upper part of the mantle is subduction metasomatsm in Archaean times (with participation of mature continental sediments) activated by plumes at 1.8 Ga and earlier which produced pervasive focused melt flow with remelting of mica-amphibole metasomatites giving continuous REE and LILE enrichment in mantle lithologies from 5.8 to 2.5 GPa.
DS202010-1827
2020
Downes, H.Ashchepkov, I., Medvedev, N., Vladykin, N., Ivanov, A., Downes, H.Thermobarometry and geochemistry of mantle xenoliths from Zapolyarnaya pipe, Upper Muna field, Yakutia: implications for mantle layering, interaction with plume melts and diamond grade.Minerals, Vol. 10, 9, 740 10.3390/ min10090755 29p. PdfRussia, Yakutiadeposit - Zapplyarnaya

Abstract: Minerals from mantle xenoliths in the Zapolyarnaya pipe in the Upper Muna field, Russia and from mineral separates from other large diamondiferous kimberlite pipes in this field (Deimos, Novinka and Komsomolskaya-Magnitnaya) were studied with EPMA and LA-ICP-MS. All pipes contain very high proportions of sub-calcic garnets. Zapolyarnaya contains mainly dunitic xenoliths with veinlets of garnets, phlogopites and Fe-rich pyroxenes similar in composition to those from sheared peridotites. PT estimates for the clinopyroxenes trace the convective inflection of the geotherm (40-45 mW•m?2) to 8 GPa, inflected at 6 GPa and overlapping with PT estimates for ilmenites derived from protokimberlites. The Upper Muna mantle lithosphere includes dunite channels from 8 to 2 GPa, which were favorable for melt movement. The primary layering deduced from the fluctuations of CaO in garnets was smoothed by the refertilization events, which formed additional pyroxenes. Clinopyroxenes from the Novinka and Komsomolskaya-Magnitnaya pipes show a more linear geotherm and three branches in the P-Fe# plot from the lithosphere base to the Moho, suggesting several episodes of pervasive melt percolation. Clinopyroxenes from Zapolyarnaya are divided into four groups according to thermobarometry and trace element patterns, which show a stepwise increase of REE and incompatible elements. Lower pressure groups including dunitic garnets have elevated REE with peaks in Rb, Th, Nb, Sr, Zr, and U, suggesting mixing of the parental protokimberlitic melts with partially melted metasomatic veins of ancient subduction origin. At least two stages of melt percolation formed the inclined PT paths: (1) an ancient garnet semi-advective geotherm (35-45 mW•m?2) formed by volatile-rich melts during the major late Archean event of lithosphere growth; and (2) a hotter megacrystic PT path (Cpx-Ilm) formed by feeding systems for kimberlite eruptions (40-45 mW•m?2). Ilmenite PT estimates trace three separate PT trajectories, suggesting a multistage process associated with metasomatism and formation of the Cpx-Phl veinlets in dunites. Heating associated with intrusions of protokimberlite caused reactivation of the mantle metasomatites rich in H2O and alkali metals and possibly favored the growth of large megacrystalline diamonds.
DS202106-0922
2021
Downes, H.Ashchepkov, I.,Medvedev, N.,Ivanov, A., Vladykin, N., Ntafos,T.,Downes, H.,Saprykin, A.,Tolstov, A.Vavilov, M., Shmarov, G.Deep mantle roots of the Zarnitsa kimberlite pipe, Siberian craton, Russia: evidence for multistage polybaric interaction with mantle melts.Journal of Asian Earth Sciences, Vol. 213, 104756, 22p.pdfRussia, Siberiadeposit - Zarnitsa

Abstract: Zarnitsa kimberlite pipe in Central Yakutia contains pyrope garnets with Cr2O3 ranging from 9 to 19.3 wt% derived from the asthenospheric mantle. They show mostly S-shaped, inflected rare earth element (REE) patterns for dunitic and harzburgitic, lherzolitic and harzburgitic varieties and all are rich in high field strength elements (HFSE) due to reaction with protokimberlite melts. Lithospheric garnets (<9 wt% Cr2O3) show a similar division into four groups but have more symmetric trace element patterns. Cr-diopsides suggest reactions with hydrous alkaline, protokimberlitic and primary (hydrous) partial melts. Cr-diopsides of metasomatic origin have inclined REE patterns and high LILE, U, Th and Zr concentrations. Four groups in REE of Ti-rich Cr-diopsides, and augites have asymmetric bell-like REE patterns and are HFSE-rich. Mg-ilmenites low in REE were formed within dunite conduits. Ilmenite derived from differentiated melts have inclined REE patterns with LREE ~ 100 × chondrite levels. Thermobarometry for dunites shows a 34 mWm?2 geotherm with a HT branch (>50 mWm?2) at 6-9 GPa, and a stepped HT geotherm with heated pyroxenite lenses at four levels from 6.5 to 3.5 GPa. Parental melts calculated with KDs suggest that augites and high-Cr garnets in the lithosphere base reacted with essentially carbonatitic melts while garnets from lower pressure show subduction peaks in U, Ba and Pb. The roots of the Zarnitsa pipe served to transfer large portions of deep (>9 GPa) protokimberlite melts to the lithosphere. Smaller diamonds were dissolved due to the elevated oxidation state but in peripheral zones large diamonds could grow.
DS202107-1088
2021
Downes, H.Ashchepkov, V., Vladykin, N.V., Kalashnyk, H.A., Medvedev, N.S., Saprykin, A.I., Downes, H., Khmelnikova, O.S.Incompatible element-enriched mantle lithosphere beneath kimberlitic pipes in Proazovie, Ukrainian shield: volatile enriched focused melt flow and connection to mature crust?International Geology Review, Vol. 63, 10, pp. 1288-1309.Europe, Ukrainedeposit - Priazovie

Abstract: Major, minor and trace element compositions of mantle xenocrysts from Devonian kimberlite pipes in the Priazovie give an insight into the mantle structure beneath the SE Ukranian Shield and its evolution. Garnets yield low temperature conditions as determined by monomineral thermobarometry. The mantle lithosphere is sharply divided at 4.2 GPa, marked by a high temperature Cpx-Ilm-Phl trend, eclogites and changes in pyrope geochemistry. Seven layers are detected: Ist layer at 2.5-1 GPa is enriched mantle (Fe#Ol ~ 0.11 ? 0.14) with Gar- pyroxenites and Sp peridotites; IInd at 2.5-3.2 GPa - Gar-Sp (Fe#Ol 0.08 ? 0.10) peridotite. IIId at 4.3-3.2 GPa is formed of Archaean- Proterozoic peridotites with Fe#Ol ~0.07 ? 0.095. IVth at 3.2-5 GPa- contains pyroxenitic Gar with higher Ca, eclogites, Chr and Cpx (Fe#Ol ~0.10 ? 0.125); Vth at 5.8 ? 5 GPa is marked by sub-Ca garnets, Cr-rich chromites and Mg-Cr ilmenites; VIth layer at 5.8-6.8 GPa contains Fe-enriched pyropes, almandines and Cr-Mg ilmenites near the lithosphere base; VIIth layer > 6.8 GPa consists of ‘hot’ Fe-rich garnets. Garnets show increasing enrichment in LREE, LILE, Hf, Zr with decreasing pressure. Primitive garnets have round REE patterns; depleted ones have S-type patterns inflected at Nd. Garnets from 6.5 to 3 GPa show increasing La/Ybn, Zr-Hf, LILE. Peridotitic clinopyroxenes have inclined linear trace element patterns rounded from La to Pr with high LILE and HFSE levels. The Fe-rich group (reacted with eclogites) shows bell-shaped irregular patterns with LILE close to the LREE levels. A possible reason for LILE (HFSE and) enrichment of the upper part of the mantle is subduction metasomatsm in Archaean times (with participation of mature continental sediments) activated by plumes at 1.8 Ga and earlier which produced pervasive focused melt flow with remelting of mica-amphibole metasomatites giving continuous REE and LILE enrichment in mantle lithologies from 5.8 to 2.5 GPa.
DS200612-0350
2006
Downes, P.J.Downes, P.J., Wartho, J-A., Giffin, B.J.Magmatic evolution and ascent history of the Aries micaceous kimberlite, central Kimberley Basin, Western Australia: evidence from zoned phlogopite phenocrysts and UV laserJournal of Petrology, Vol. 47, 9, Sept. pp. 1751-1783.Australia, Western AustraliaGeochronology - UV laser, analysis phlogopite-biotite
DS200712-0274
2007
Downes, P.J.Downes, P.J., Bevan, A.W.R.Diamonds in western Australia.Rocks and Minerals, Vol. 82, 1, pp. 66-76.AustraliaHistory
DS200712-0275
2007
Downes, P.J.Downes, P.J., Griffin, B.J., Griffin, W.L.Mineral chemistry and zircon geochronology of xenocrysts and altered mantle and crustal xenoliths from the Aries micaceous kimberlite: constraints age..Lithos, Vol. 93, 1-2, pp. 175-198.AustraliaKimberly Craton - central composition age
DS201012-0258
2010
Downes, P.J.Gwalani, L.G., Rogers, K.A., Demeny, A., Groves, D.L., Ramsay, R., Beard, A., Downes, P.J., Eves, A.The Yungul carbonatite dykes associated with the epithermal fluorite deposit at Speewah, Kimberley, Australia: carbon and oxygen isotope constraints originMineralogy and Petrology, Vol. 98, 1-4, pp. 123-141.AustraliaCarbonatite
DS201412-0209
2014
Downes, P.J.Downes, P.J., Demeny, A., Czuppon, G., Jacques, A.L., Verrall, M., Sweetapple, M., Adams, D., McNaughton, N.J., Gwalani, L.G., Griffin, B.J.Stable H-C-O isotope and trace element geochemistry of the Cummins Range carbonatite complex, Kimberley region Western Australia: implications for hydrothermal REE mineralization, carbonatite evolution and mantle source regions.Mineralium Deposita, in press available 28p.AustraliaCarbonatite
DS201412-0210
2014
Downes, P.J.Downes, P.J., Demeny, A., Czuppon, G., Jaques, A.L., Verrall, M., Sweetapple, M., Adams, D., McNaughton, N.J., Gwalani, L.G., Griffin, B.J.Stable H-C-O isotope and trace element geochemistry of the Cummins Range carbonatite complex, Kimberley region western Australia: implications for hydrothermal REE mineralization, carbonatite evolution and mantle source regions.Mineralium Deposita, Vol. 49, p. 905-932.AustraliaCarbonatite
DS201511-1833
2014
Downes, P.J.Downes, P.J., Bevan, A.W.R., Deacon, G.L.The Kimberley Diamond Company Ellendale diamond collection at the Western Australia Museum.Australian Gemmologist, Vol. 24, 12, pp. 289-293.AustraliaDeposit - Ellendale
DS201602-0203
2016
Downes, P.J.Downes, P.J., Dunkley, D.J., Fletcher, I.R., McNaughton, N.J., Rasmusson, B., Jaques, A.L., Verall, M., Sweetapple, M.T.Zirconolite, zircon and monazite-(Ce) U-Th-Pb age constraints on the emplacement, deformation and alteration history of the Cummins Range carbonatite complex, Halls Creek orogen, Kimberley region, Western Australia.Mineralogy and Petrology, In press available, 24p.AustraliaCarbonatite

Abstract: In situ SHRIMP U-Pb dating of zirconolite in clinopyroxenite from the Cummins Range Carbonatite Complex, situated in the southern Halls Creek Orogen, Kimberley region, Western Australia, has provided a reliable 207Pb/206Pb age of emplacement of 1009 ± 16 Ma. Variably metamict and recrystallised zircons from co-magmatic carbonatites, including a megacryst ~1.5 cm long, gave a range of ages from ~1043-998 Ma, reflecting partial isotopic resetting during post-emplacement deformation and alteration. Monazite-(Ce) in a strongly foliated dolomite carbonatite produced U-Th-Pb dates ranging from ~900-590 Ma. Although the monazite-(Ce) data cannot give any definitive ages, they clearly reflect a long history of hydrothermal alteration/recrystallisation, over at least 300 million years. This is consistent with the apparent resetting of the Rb-Sr and K-Ar isotopic systems by a post-emplacement thermal event at ~900 Ma during the intracratonic Yampi Orogeny. The emplacement of the Cummins Range Carbonatite Complex probably resulted from the reactivation of a deep crustal structure within the Halls Creek Orogen during the amalgamation of Proterozoic Australia with Rodinia over the period ~1000-950 Ma. This may have allowed an alkaline carbonated silicate magma that was parental to the Cummins Range carbonatites, and generated by redox and/or decompression partial melting of the asthenospheric mantle, to ascend from the base of the continental lithosphere along the lithospheric discontinuity constituted by the southern edge of the Halls Creek Orogen. There is no evidence of a link between the emplacement of the Cummins Range Carbonatite Complex and mafic large igneous province magmatism indicative of mantle plume activity. Rather, patterns of Proterozoic alkaline magmatism in the Kimberley Craton may have been controlled by changing plate motions during the Nuna-Rodinia supercontinent cycles (~1200-800 Ma).
DS201604-0609
2016
Downes, P.J.Gwalani, L.G., Jaques, A.L., Downes, P.J., Chalapathi Rao, N.V.Kimberlites, lamproites, carbonatites and associated alkaline rocks: a tribute to the work of Rex T. Prider VolumeMineralogy and Petrology, in press available 5p.MantlePrider volume
DS1987-0484
1987
Downey, M.Mitchell, R.H., Platt, R.G., Downey, M.Petrology of lamproites from Smoky Butte, MontanaJournal of Petrology, Vol. 28, No. 4, August pp. 645-677MontanaAnalyses, Petrology
DS1987-0485
1987
Downey, M.Mitchell, R.H., Platt, R.G., Downey, M.Petrology of lamproites from Smokey Butte, MontanaJournal of Petrology, Vol. 28, No. 4, August pp. 645-678MontanaLamproite
DS1991-1175
1991
Downey, M.Mitchell, R.H., Platt, R.G., Downey, M., Laderoute, D.G.Petrology of alkaline lamprophyres from the Coldwell alkaline complex, northwestern OntarioCanadian Journal of Earth Sciences, Vol. 28, No. 10, October pp. 1653-1663OntarioAlkaline lamprophyres, Petrology, Coldwell
DS1992-0389
1992
Downey, M.W.Downey, M.W.Appropriate people and proper organization for successful exploration.Paper quoted during Woodall's address to SEG Denver MeetingArco, 11pUnited StatesEconomics, Exploration philosophy
DS200912-0186
2009
Downey, N.J.Downey, N.J., Gurnis, M.Instantaneous dynamics of the cratonic Congo basin.Journal of Geophysical Research, Vol. 114, B06401AfricaGeodynamics
DS1960-0234
1962
Downie, C.Downie, C., Wilkinson, P.The Explosion Craters of Basotu, Tanganyika TerritoryBulletin. VOLCANOLOGIQUE., Vol. 24, PP. 389-420.Tanzania, East AfricaDiatreme
DS200712-0276
2007
Downie, I.Downie, I.Results driven risk management ( through new and enhanced technology, manpower and process). The holistic approach.Diamonds in Kimberley Symposium & Trade Show, Bristow and De Wit held August 23-24, Kimberley, South Africa, GSSA Diamond Workshop CD slides 26TechnologyResponsibility, social, chain of data interface(s)
DS1984-0241
1984
Downie, I.F.Downie, I.F.Kimberlite Indicators from Wisconsin- the Wahl ProjectBp Selco In House Memo, 2P.United States, Great Lakes, WisconsinProspecting, Sampling
DS1986-0396
1986
Downie, I.F.Janse, A.J.A., Downie, I.F., Reed, L.E., Sinclair, I.G.L.Alkaline diatremes in the Hudson Bay Lowlands, Canada,explorationmethods, petrology and geochemistryProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 469-471OntarioDiamond exploration
DS1986-0397
1986
Downie, I.F.Janse, A.J.A., Downie, I.F., Reef, L.E., Sinclair, I.G.L.Alkaline diatremes in the Hudson Bay Lowlands: explorationmethods, mineralogy, petrology and geochemistryFick ( Proceedings Of The Fourth International Kimberlite Conference), Abstract 1pOntario, James Bay LowlandsAlkaline rocks
DS1989-0699
1989
Downie, I.F.Janse, A.J.A., Downie, I.F., Reed, L.E., Sinclair, I.G.L.Alkaline intrusions in the Hudson Bay Lowlands, Canada: explorationmethods, petrologyGeological Society of Australia Inc. Blackwell Scientific Publishing, Special, No. 14, Vol. 2, pp. 1192-1203OntarioExploration techniques, Geophysics, Petrology
DS1999-0173
1999
Downie, I.F.Downie, I.F.Metallic and industrial mineral assessment report for kimberlites in Muskwa and Teepee Lakes area, .Alberta Geological Survey, MIN 19990005AlbertaExploration - assessment, Montello Resources Ltd.
DS1995-0538
1995
Downing, B.Filion, M., Downing, B.Environmental due diligence -property transactionsProspectors and Developers Association of Canada (PDAC) Short Course, March 4, pp. 165-170GlobalDue diligence, Environmental -ore reserves
DS1989-1326
1989
Downing, B.J.Salter, J.D., Nordin, L., Downing, B.J.Kimberlite-gabbro sorting by use of microwave attentuation: development from the laboratory to a 100 t/h pilot plantInstitute of Mining and Metallurgy (IMM) Proceedings of MMIJ Today's technology for the mining and metalurgical, pp. 347-358GlobalMineral processing, Kimberlite
DS1990-1294
1990
Downing, B.J.Salter, J.D., Downing, B.J., Rix, G.M., Marais, M.G.Development of rock pass level monitors for Finsch diamond mine, SouthAfrica14th. Cmmi Congress Held Edinburgh, Scotland July 2-6, 1990 Institute Of Mining And Metallurgy (imm) Proceedings, pp. 107-111South AfricaMining, Finsch mine
DS1993-1370
1993
Downing, B.J.Salter, J.D., Nordin, L., Downing, B.J.Kimberlite-gabbro sorting use of microwave attenuation:development laboratory -100 t/h pilot plantUnknown, pp. 347-358.South AfricaMineral processing, Deposit -Premier
DS1993-0416
1993
Downing, D.Erdmer, P., Downing, D.Geological, geochemical and geophysical exploration for diamonds in YukonIndian and Northern Affairs Canada, Yukon Region, Open File 1993-5, (T) 71p.YukonOverview of kimberlite exploration -general
DS2001-0269
2001
Downing, D.Downing, D.Canada, 2001Mining Annual Review 2001, 14p.CanadaCountry - overview, economics, mining, Overview - brief
DS1993-0373
1993
Downing, D.A.Downing, D.A.Industrial minerals and minor metals and their potential for development In the YukonYukon Indian and Northern Affairs, Open file 1993-4, 52pYukonIndustrial minerals, Rare earths
DS1982-0416
1982
Downs, J.W.Mcbride, J.H., Downs, J.W.Structural Significance of Circular Land sat Anomalies in The Ozark Region of Missouri and Arkansaw.Geological Society of America (GSA), Vol. 14, No. 7, PP. 559-560, (abstract.).GlobalMid-continent
DS201709-2035
2017
Downs, R.J.Morrison, S.M., Liu, C., Prabhu, E.A., Li, C., Downs, R.J., Golden, J.J., Fox, P., Hummer, D.R., Meyer, M.B., Hazen, R.M.Network analysis of mineralogical systems.American Mineralogist, in press availableTechnologydata sets

Abstract: A fundamental goal of mineralogy and petrology is the deep understanding of mineral phase relationships and the consequent spatial and temporal patterns of mineral coexistence in rocks, ore bodies, sediments, meteorites, and other natural polycrystalline materials. The multi-dimensional chemical complexity of such mineral assemblages has traditionally led to experimental and theoretical consideration of 2-, 3-, or n-component systems that represent simplified approximations of natural systems. Network analysis provides a dynamic, quantitative, and predictive visualization framework for employing “big data” to explore complex and otherwise hidden higher-dimensional patterns of diversity and distribution in such mineral systems. We introduce and explore applications of mineral network analysis, in which mineral species are represented by nodes, while coexistence of minerals is indicated by lines between nodes. This approach provides a dynamic visualization platform for higher-dimensional analysis of phase relationships, because topologies of equilibrium phase assemblages and pathways of mineral reaction series are embedded within the networks. Mineral networks also facilitate quantitative comparison of lithologies from different planets and moons, the analysis of coexistence patterns simultaneously among hundreds of mineral species and their localities, the exploration of varied paragenetic modes of mineral groups, and investigation of changing patterns of mineral occurrence through deep time. Mineral network analysis, furthermore, represents an effective visual approach to teaching and learning in mineralogy and petrology.
DS1991-0626
1991
Downs, R.T.Gunter, M.E., Downs, R.T.Drill: a computer program to aid in building ball and spoke crystalmodelsAmerican Mineralogist, Vol. 76, No. 1-2, Jan-February pp. 293-295GlobalComputer program, Drill: crystal modeling
DS1996-0380
1996
Downs, R.T.Downs, R.T., et al.The equation of state of forsterite to 17.2 GPas and effects of pressuremedia.American Mineralogist, Vol. 81, No. Jan-Feb pp. 51-55.MantlePetrology -experimental
DS1998-1189
1998
Downs, R.T.Prewitt, C.T., Downs, R.T.high pressure crystal chemistryReviews in Mineralogy, Vol. 37, pp. 284-318.MantleMineralogy, Petrology - experimental
DS200512-1083
2005
Downs, R.T.Thompson, R.M., Downs, R.T., Redhammer, G.J.Model pyroxenes III: volume of C2/c pyroxenes at mantle P,T, and x.American Mineralogist, Vol. 90, Nov-Dec. pp. 1840-1851.MantleMantle minerals, chemistry
DS201503-0160
2015
Downs, R.T.Menezes Filho, L.A.D., Atencio, D., Andrade, M.B., Downs, R.T., Chaves, M.L.S.C., Romano, A.W., Scholz, R., Persiano, A.I.C.Pauloabibite, trigonal NaNbO3, isostructural with ilmenite, from the Jacupiranga carbonatite, Cajati, Sao Paulo, Brazil.American Mineralogist, Vol. 100, pp. 442-446.South America, BrazilCarbonatite
DS201508-0360
2015
Downs, R.T.Hystad, G., Downs, R.T., Hazen, R.M.Mineral species frequency distribution conforms to a large number of rare events model: prediction of Earth's missing minerals.Mathematical Geosciences, Vol. 47, no. 6, pp. 647-661.TechnologyNot specific to diamonds but interesting reading!
DS201511-1842
2015
Downs, R.T.Hazen, R.M., Hystad, G., Downs, R.T., Golden, J.J., Pires, A.J., Grew, E.S.Earth's missing minerals.American Mineralogist, Vol. 100, pp. 2344-2347.TechnologyMineralogy

Abstract: Recent studies of mineral diversity and distribution lead to the prediction of >1563 mineral species on Earth today that have yet to be described-approximately one fourth of the 6394 estimated total mineralogical diversity. The distribution of these "missing" minerals is not uniform with respect to their essential chemical elements. Of 15 geochemically diverse elements (Al, B, C, Cr, Cu, Mg, Na, Ni, P, S, Si, Ta, Te, U, and V), we predict that approximately 25% of the minerals of Al, B, C, Cr, P, Si, and Ta remain to be described - a percentage similar to that predicted for all minerals. Almost 35% of the minerals of Na are predicted to be undiscovered, a situation resulting from more than 50% of Na minerals being white, poorly crystallized, and/or water soluble, and thus easily overlooked. In contrast, we predict that fewer than 20% of the minerals of Cu, Mg, Ni, S, Te, U, and V remain to be discovered. In addition to the economic value of most of these elements, their minerals tend to be brightly colored and/or well crystallized, and thus likely to draw attention and interest. These disparities in percentages of undiscovered minerals reflect not only natural processes, but also sociological factors in the search, discovery, and description of mineral species.
DS201605-0844
2016
Downs, R.T.Hazen, R.M., Hummer, D.R., Hystad, G., Downs, R.T., Golden, J.J.Carbon mineral ecology: predicting the undiscovered minerals of carbon.American Mineralogist, Vol. 101, pp. 889-906.TechnologyCarbon minerals
DS201908-1779
2019
Downs, R.T.Hystad, G., Eleish, A., Hazen, R.M., Morrison, S.M., Downs, R.T.Bayesian estimation of Earth's undiscovered mineralogical diversity using noninformative priors. * not specific to diamondsMathematical Geosciences, Vol. 51, pp. 401-417.MantlePoisson-lognormal

Abstract: Recently, statistical distributions have been explored to provide estimates of the mineralogical diversity of Earth, and Earth-like planets. In this paper, a Bayesian approach is introduced to estimate Earth’s undiscovered mineralogical diversity. Samples are generated from a posterior distribution of the model parameters using Markov chain Monte Carlo simulations such that estimates and inference are directly obtained. It was previously shown that the mineral species frequency distribution conforms to a generalized inverse Gauss-Poisson (GIGP) large number of rare events model. Even though the model fit was good, the population size estimate obtained by using this model was found to be unreasonably low by mineralogists. In this paper, several zero-truncated, mixed Poisson distributions are fitted and compared, where the Poisson-lognormal distribution is found to provide the best fit. Subsequently, the population size estimates obtained by Bayesian methods are compared to the empirical Bayes estimates. Species accumulation curves are constructed and employed to estimate the population size as a function of sampling size. Finally, the relative abundances, and hence the occurrence probabilities of species in a random sample, are calculated numerically for all mineral species in Earth’s crust using the Poisson-lognormal distribution. These calculations are connected and compared to the calculations obtained in a previous paper using the GIGP model for which mineralogical criteria of an Earth-like planet were given.
DS1999-0390
1999
Dowsett, J.S.La Prairie, L.F., Vuori, H.F., Dowsett, J.S.Darnley Bay: part 1. historical perspectives on exploration. part 2: theproject... mentions anomalies.8th. Calgary Mining forum, 5p. abstractNorthwest TerritoriesNews item, Darnley Bay
DS1970-0471
1972
Dowty, E.Aoki, K., Fodor, K.K., Dowty, E.Tremolite with High Richterite-molecule Content in Kimberlite from Buell Park, Arizona.American MINERALOGIST., Vol. 57, PP. 1889-1893.ArizonaKimberlite, Colorado Plateau, Rocky Mountains
DS1982-0250
1982
Dowty, E.Harlow, G.E., Dowty, E.K-bearing Omphacite: Significance for Mantle AssemblagesGeological Society of America (GSA), Vol. 14, No. 7, P. 507, (abstract.).GlobalEclogite
DS1998-0306
1998
DoyleDavies, R., Griffin, W.L., Pearson, N.J., Andrew, DoyleDiamonds from the Deep: Pipe DO 27, Slave Craton, Canada7th International Kimberlite Conference Abstract, pp. 170-172.Northwest TerritoriesDiamond inclusions, Deposit - Pipe DO-27
DS1998-0528
1998
DoyleGraham, I., Burgess, bryan, Ravenscroft, Thomas, DoyleThe Diavik kimberlites - Lac de Gras, Northwest Territories, Canada7th International Kimberlite Conference Abstract, pp. 259-61.Northwest TerritoriesHistory, kimberlite, evaluation, Deposit - Diavik
DS1998-1140
1998
DoylePearson, N.J., Griffin, W.L., Doyle, O'Reilly, KiviXenoliths from kimberlite pipes of the Lac de Gras area, Slave Craton, Canada.7th. Kimberlite Conference abstract, pp. 670-2.Northwest TerritoriesGeothermometry, Xenoliths
DS1999-0545
1999
DoylePearson, Griffin, Doyle, O'Reilly, Van Acterbergh, KiviXenoliths from kimberlite pipes of the Lac de Gras area, Slave Craton, Canada. (DO18, 27, A154S)7th International Kimberlite Conference Nixon, Vol. 2, pp. 644-58.Northwest TerritoriesPetrography, mineral chemistry, analyses, thermometry
DS2001-0062
2001
DoyleAulbach, S., Griffin, Pearson, O'Reilly, Doyle, KiviRe Os isotope evidence for Meso-Archean mantle beneath 2.7 Ga Contwoyto Terrane, implications tectonic historySlave-Kaapvaal Workshop, Sept. Ottawa, 5p. abstractMantleGeochemistry - major, trace elements, Slave Craton - tectonics
DS200512-0598
2004
Doyle, B.Larson, P., Doyle, B., Kivi, K.Utilization of drift exploration techniques to constrain kimberlite indicator dispersal, train sources, Credit Lake property, Nunavut.32nd Yellowknife Geoscience Forum, Nov. 16-18, p.44. (talk)Canada, NunavutGeomorphology - till
DS201605-0830
2016
Doyle, B.Doyle, B.Testing the economic viability of a Diamondiferous kimberlite.Vancouver Kimberlite Cluster, May 5, 1p. AbstractTechnologyMicrodiamonds, sampling
DS1995-0439
1995
Doyle, B.J.Doyle, B.J., Stephenson, J.F.An overview of exploration for kimberlites in the Lac de Gras area with specific reference to DO27 pipe.Yellowknife 95, program and abstracts, Sept. 6-8, p. 37-39.Northwest TerritoriesOverview, Kennecott
DS1998-0363
1998
Doyle, B.J.Doyle, B.J., Kivi, K., Scott Smith, B.H.The Tli Kwi Cho ( DO 27 and DO 18) Diamondiferous kimberlite complex SlaveCraton, Northwest Territories.7th International Kimberlite Conference Abstract, pp. 199-201.Northwest TerritoriesGeology, petrology, Deposit - Tli Kwi Cho
DS1998-0535
1998
Doyle, B.J.Griffin, W.L., Doyle, B.J., Ryan, Pearson, O'ReillyLithosphere structure and mantle terranes: Slave Craton, Canada7th International Kimberlite Conference Abstract, pp. 271-273.Northwest TerritoriesTerranes, xenoliths, Deposit - Ranch Lake, Jericho, Cross Lake
DS1999-0266
1999
Doyle, B.J.Griffin, W.L., Doyle, B.J., Natapov, L.M.Layered mantle lithosphere in the Lac de Gras area, Slave Craton:composition, structure and origin.Journal of Petrology, Vol. 40, No. 5, May, pp. 705-28.Northwest TerritoriesMantle, Tectonics
DS2003-0050
2003
Doyle, B.J.Aulbach, S., Griffin, W.L., Pearson, N.J., O'Reilly, S.Y., Kivi, K., Doyle, B.J.Origins of eclogites beneath the central Slave Craton8ikc, Www.venuewest.com/8ikc/program.htm, Session 2, POSTER abstractNorthwest TerritoriesEclogites and Diamonds
DS2003-0316
2003
Doyle, B.J.Davies, R.M., Griffin, W.L., O'Reilly, S.Y., Doyle, B.J.Geochemical characteristics of microdiamonds from kimberlites at Lac de Gras, Central8 Ikc Www.venuewest.com/8ikc/program.htm, Session 3, AbstractNorthwest TerritoriesDiamonds - micro, Geochemistry
DS2003-0503
2003
Doyle, B.J.Griffin, W.L., O'Reilly, S.Y., Doyle, B.J., Kivi, K.Lithospheric mapping beneath the North American plate8 Ikc Www.venuewest.com/8ikc/program.htm, Session 9, AbstractNorthwest Territories, Greenland, LabradorCraton studies, SLCM
DS2003-0890
2003
Doyle, B.J.Masun, K.M., Doyle, B.J., Ball, S., Walker, S.The geology and mineralogy of the Anuri kimberlite, Nunavut, Canada31st Yellowknife Geoscience Forum, p. 63. (abst.)NunavutMineralogy
DS2003-0891
2003
Doyle, B.J.Masun, K.M., Doyle, B.J., Ball, S.A., Walker, S.The geology and mineralogy of the Anuri kimberlite, Nunavut, Canada8ikc, Www.venuewest.com/8ikc/program.htm, Session 1 POSTER abstractNunavutKimberlite geology and economics, Deposit - Anuri
DS2003-1097
2003
Doyle, B.J.Poudjom Dojomani, Y.H., O'Reilly, S.Y., Griffin, W.L., Doyle, B.J.Geophysical analysis of the lithosphere beneath the Slave Craton8 Ikc Www.venuewest.com/8ikc/program.htm, Session 9, POSTER abstractNorthwest TerritoriesGeophysics
DS200412-0076
2004
Doyle, B.J.Aulbach, S., Griffin, W.L., Pearson, N.J., O'Reilly, S.Y., Kivi, K., Doyle, B.J.Mantle formation and evolution, Slave Craton: constraints from HSE abundances and Re Os isotope systematics of sulfide inclusionChemical Geology, Vol. 208, 1-4, pp. 61-88.Canada, Northwest TerritoriesGeochronology, Lac de Gras, metasomatism, melt-deletion
DS200412-0415
2003
Doyle, B.J.Davies, R.M., Griffin, W.L., O'Reilly, S.Y., Doyle, B.J.Geochemical characteristics of microdiamonds from kimberlites at Lac de Gras, Central Slave Craton, Canada.8 IKC Program, Session 3, AbstractCanada, Northwest TerritoriesDiamonds - micro, geochemistry
DS200412-0416
2004
Doyle, B.J.Davies, R.M., Griffin, W.L., O'Reilly, S.Y., Doyle, B.J.Mineral inclusions and geochemical characteristics of microdiamonds from the DO27, A154, A21, A418, DO18, DD17 and Ranch Lake kiLithos, Vol. 77, 1-4, Sept. pp. 39-55.Canada, Northwest TerritoriesSlave Craton, diamond inclusions, C isotopes, N content
DS200412-0723
2003
Doyle, B.J.Griffin, W.L., O'Reilly, S.Y., Abe, N., Aulbach, S., Davies, R.M., Pearson, N.J., Doyle, B.J.,Kivi, K.The origin and evolution of Archean lithospheric mantle.Precambrian Research, Vol. 127, 1-2, Nov. pp. 19-41.China, Africa, Russia, Canada, Northwest TerritoriesGeochemistry, SCLM, continental, Archon, metasomatism
DS200412-0724
2003
Doyle, B.J.Griffin, W.L., O'Reilly, S.Y., Doyle, B.J., Kivi, K.Lithospheric mapping beneath the North American plate.8 IKC Program, Session 9, AbstractCanada, Northwest Territories, Quebec, Labrador, Europe, GreenlandCraton studies, SLCM
DS200412-0725
2004
Doyle, B.J.Griffin, W.L., O'Reilly, S.Y., Doyle, B.J., Pearson, N.J., Coopersmith, H., Kivi, K., Melkovets, V., PokhilenkLithosphere mapping beneath the North American plate.Lithos, Vol. 77, 1-4, Sept. pp. 873-922.Canada, Northwest Territories, Europe, GreenlandArchon, Proton, Tecton, Slave Craton, Kapuskasing Struc
DS200412-1244
2003
Doyle, B.J.Masun, K.M., Doyle, B.J., Ball, S., Walker, S.The geology and mineralogy of the Anuri kimberlite, Nunavut, Canada.31st Yellowknife Geoscience Forum, p. 63. (abst.Canada, NunavutMineralogy
DS200412-1572
2003
Doyle, B.J.Poudjom Dojomani, Y.H., O'Reilly, S.Y., Griffin, W.L., Doyle, B.J.Geophysical analysis of the lithosphere beneath the Slave Craton.8 IKC Program, Session 9, POSTER abstractCanada, Northwest TerritoriesCraton studies Geophysics
DS200412-2033
2003
Doyle, B.J.Van Achterbergh, E., Griffin, W.L., O'Reilly, S.Y., Ryan, C.G., Pearson, N.J., Kivi, K., Doyle, B.J.Melt inclusions from the deep Slave lithosphere: constraints on the origin and evolution of mantle derived carbonatite and kimbe8 IKC Program, Session 3, AbstractCanada, Northwest TerritoriesDiamonds - melting
DS200512-0234
2005
Doyle, B.J.Djomani, Y.H.P., O'Reilly, S.Y., Griffin, W.L., Natapov, L.M., Pearson, N.J., Doyle, B.J.Variations of the effective elastic thickness (Te) and structure of the lithosphere beneath the Slave Province, Canada.Exploration Geophysics, Vol. 36, 3, pp. 266-271.Canada, Northwest TerritoriesGeophysics - seismics, telurics
DS200712-0037
2007
Doyle, B.J.Aulbach, S., Griffin, W.L., Pearson, N.J., O'Reilly, S.Y., Doyle, B.J.Lithosphere formation in the central Slave Craton ( Canada): plume subcretion or lithosphere accretion.Contributions to Mineralogy and Petrology, Vol. 154, 4, pp. 409-427.Canada, Northwest TerritoriesAccretion
DS200712-0038
2007
Doyle, B.J.Aulbach, S., Pearson, N.J., O'Reilly, S.Y., Doyle, B.J.Origins of xenolithic eclogites and pyroxenites from the Central Slave Craton, Canada.Journal of Petrology, Vol. 48, 10, pp. 1843-1873.Canada, Northwest TerritoriesEclogite, geochemistry, geochronology, isotopes
DS200812-0297
2008
Doyle, B.J.Doyle, B.J., Gill, T.I., Thompson, V.The discovery of the Dharma kimberlite complex: evidence for a previously unknown Archean terrain north of Great Bear Lake.Northwest Territories Geoscience Office, p. 21. abstractCanada, Northwest TerritoriesBrief overview - Sanatana, Kennecott
DS201012-0170
2010
Doyle, E.E.Doyle, E.E., Hogg, A.J., Mader, H.M., Sparks, R.S.J.A two layer model for the evolution and propogation of dense and dilute regions of pyroclastic currents.Journal of Volcanology and Geothermal Research, Vol. 190, 3-4, pp. 365-378.TechnologyVolcanism
DS1990-0425
1990
Doyle, H.A.Doyle, H.A.A short history of Australian GeophysicsExploration Geophysics, Vol. 20, No. 4, December pp. 491-496AustraliaOverview, Geophysics -history
DS1993-1013
1993
Doyle, M.McPhie, J., Doyle, M., Allen, R.Volcanic texturesCodes Key Centre, University Of Of Tasmania, $ 90.00United States, Japan, New Zealand, Central and South AmericaBook -ad, Volcanic textures
DS200812-0298
2008
Doyle, M.Doyle, M.'Fishing for Diamonds' Ontario's first diamond mine. VictorProspectors and Developers Association of Canada, March 3, 1/8p. abstract.Canada, Ontario, AttawapiskatVictor - overview
DS201812-2803
2018
Doyle, M.Doyle, M.Perspectives on diamond exploration and evaluation strategies.7th Symposio Brasileiro de Geologia do Diamante , Title only South America, Brazilvaluation
DS2003-0350
2003
Doyle, P.M.Doyle, P.M., Gurney, J.J., Le Roex, A.Xenoliths from the Arnie, Misery and Pigeon kimberlites8ikc, Www.venuewest.com/8ikc/program.htm, Session 4, POSTER abstractNorthwest TerritoriesMantle geochemistry, Deposit - Arnie, Misery, Pigeon
DS200412-0480
2004
Doyle, P.M.Doyle, P.M., Bell, B.R., Le Roex, A.P.Fine grained pyroxenites from the Gansfontein kimberlite, South Africa: evidence for megacryst magma - mantle interaction.South African Journal of Geology, Vol. 107, 1/2, pp. 285-300.Africa, South AfricaDeposit - Gansfontein, petrology
DS200412-0481
2004
Dozier, J.Dozier, J., Painter, T.H.Multispectral and hyper spectral remote sensing of alpine snow properties.Annual Review of Earth and Planetary Sciences, Vol. 32, May pp. 465-494.TechnologyOverview - Hyperspectral remote sensing
DS1993-0374
1993
DPNM BrasilDPNM BrasilAnnual; production -for 1991Dpnm Brasil, pp. 268-269.BrazilDiamond production, Economics
DS200712-0377
2007
Drab, L.Goutorbe, B., Drab, L., Loubet, N., Lucazeau, F.Heat flow of the eastern Canadian rifted continental margin revisited.Terra Nova, Vol. 19, 6, pp. 381-386.CanadaGeothermometry
DS2002-1021
2002
DragertMazzotti, S., Dragert, Hyndman, Miller, HentonGPS deformation in a region of high crustal seismicity: N. Cascadia forearcEarth and Planetary Science Letters, Vol.198,1-2,pp.41-8., Vol.198,1-2,pp.41-8.CordilleraGeophysics - seismics not specific to diamonds
DS2002-1022
2002
DragertMazzotti, S., Dragert, Hyndman, Miller, HentonGPS deformation in a region of high crustal seismicity: N. Cascadia forearcEarth and Planetary Science Letters, Vol.198,1-2,pp.41-8., Vol.198,1-2,pp.41-8.CordilleraGeophysics - seismics not specific to diamonds
DS201112-0199
2010
Drago, S.Conceicao, R.V., Green, D.H., Lenz, C., Gervasconi, F., Drago, S.Derivation of potassic magmas by decompression melting of phlogopite+pargasite lherzolite.5th Brasilian Symposium on Diamond Geology, Nov. 6-12, abstract p. 74.MantleMetasomatism
DS201112-0200
2010
Drago, S.Conceicao, R.V., Lenz, C., Gervasconi, F., Drago, S.Origin of the potassium in the Earth-Moon system and contribution for the K-rich rocks.5th Brasilian Symposium on Diamond Geology, Nov. 6-12, abstract p. 73.MantleMelting
DS201903-0499
2019
Dragone, G.N.Bologna, M.S., Dragone, G.N., Muzio, R., Peel, E., Nunez, Demarco, P., Ussami, N.Electrical structure of the lithosphere from Rio de la Plata craton to Parana Basin: amalgamation of cratonic and refertilized lithospheres in SW Gondwanaland.Tectonics, Vol. 38, 1, pp. 77-94.South America, Brazilcraton

Abstract: We conducted a magnetotelluric (MT) study from Paleoproterozoic Rio de la Plata Craton, in Uruguay, toward Paleozoic?Mesozoic Paraná Basin, in Brazil. The 850?km?long MT transect comprises 35 evenly spaced broadband electromagnetic soundings sites. In the Paraná Basin, 11 additional long?period measurements were acquired to extend the maximum depth of investigation. All data were inverted using two? and three?dimensional approaches obtaining the electrical resistivity structure from the surface down to 200 km. The Rio de la Plata Craton is >200?km thick and resistive (~2,000 ?m). Its northern limit is electrically defined by a lithosphere scale lateral transition and lower crust conductive anomalies (1-10 ?m) interpreted as a Paleoproterozoic suture at the southern edge of Rivera?Taquarembó Block. The latter is characterized by an approximately 100?km thick and moderate resistive (>500 ?m) upper mantle. The Ibaré shear zone is another suture where an ocean?ocean subduction generated the 120?km thick and resistive (>1,000 ?m) Săo Gabriel juvenile arc. Proceeding northward, a 70? to 80?km thick, 150?km wide, and inclined resistive zone is imaged. This zone could be remnant of an oceanic lithosphere or island arcs accreted at the southern border of Paraná Basin. The MT transect terminates within the southern Paraná Basin where a 150? to 200?km?thick less resistive lithosphere (<1,000 ?m) may indicate refertilization processes during plate subduction and ocean closure in Neoproterozoic?Cambrian time. Our MT data support a tectonic model of NNE-SSW convergence for this segment of SW Gondwanaland.
DS202108-1279
2021
Dragone, G.N.Dragone, G.N., Bologna, M.S., Ussami, N., Gimenez, M.E., Alvarez, O., Klinger, F.G.L., Correa-Otto, S.Lithosphere of South American intracratonic basins: electromagnetic and potential field data reveal cratons, terranes, and sutures.Tectonophysics, Vol. 811, 13p. PdfSouth America, Argentinacratons

Abstract: A magnetotelluric survey comprising 18 broadband stations disposed along a 450 km-long profile was carried out at the transition between the Chaco-Paraná (CPB) and the Paraná (PB) intracratonic basins in northeastern Argentina. Three-dimensional inversions of the responses show that the CPB and southern PB lithospheres are resistive (~103 ? m) down to 120 km, but with distinct crustal and upper mantle electrical properties. Also, Bouguer gravity and density anomalies are positive at CPB, whereas they are negative at PB. We associate the CPB lithosphere with the Paleoproterozoic Rio Tebicuary craton and the southern PB lithosphere with an ancient and buried piece of craton, the Southern Paraná craton. Geochemical data of mantle xenoliths from the Cenozoic alkaline/carbonatitic province within the Rio Tebicuary craton suggest a subcontinental lithospheric mantle affected by metasomatic processes, which explains its lower resistivity (reaching values as low as 300 ? m) and higher density (#Mg = 0.87). In contrast, the Southern Paraná craton is more resistive (>103 ? m) and less dense, suggesting a de-hydrated, depleted, and thicker craton. These cratons are separated by a crustal conductor (15 to 20 km depth; 1-10 ? m) that we interpret as a southward continuation of a linear anomaly (Paraná Axial Anomaly) defined in former induction studies within the PB in Brazil. Hence, we redefined the trace of this conductive lineament: instead of bending towards the Torres Syncline, it continues inside the CPB. We propose the lineament to be an Early Neoproterozoic suture zone that controlled the location of maximum subsidence in the intracratonic basins during the Paleozoic. In the Early Cretaceous, the Paraná Axial Anomaly was the site of maximum extrusion and deposition of Serra Geral basalts. This anomaly separates compositionally distinct cratonic lithospheres along its path. Melting of this heterogeneous and enriched mantle created the Paraná igneous province.
DS1994-0450
1994
Dragoni, M.Dragoni, M., Pasquale, V., Verdoya, M., CVhiozzi, P.Rheological consequences of the lithospheric thermal structure in the Fennoscandian shield.Global and Planetary Change, Vol. 8, pp. 113-126.GlobalLithosphere, Structure
DS201112-0911
2011
Dragoni, M.Santini, S., Tallarico, A., Dragoni, M.Magma ascent and effusion from a tensile fracture propogating to the Earth's urface.Geophysical Journal International, in press available,MantleMineral physics, rheology, heat flow, plumes
DS201803-0436
2017
Dragovic, B.Baxter, E.F., Caddick, M.J., Dragovic, B.Garnet: a rock forming mineral petrochronometer.Reviews in Mineralogy & Geochemistry, Vol. 83, Chap. 15, pp. 469-533.Technologygeochronology

Abstract: Garnet could be the ultimate petrochronometer. Not only can you date it directly (with an accuracy and precision that may surprise some), but it is also a common rock-forming and porphyroblast-forming mineral, with wide ranging—yet thermodynamically well understood—solid solution that provides direct and quantitative petrologic context. While accessory phase petrochronology is based largely upon establishing links to the growth or breakdown of key rock-forming pressure–temperature–composition (P–T–X) indicators (e.g., Rubatto 2002; Williams et al. 2007), garnet is one of those key indicator minerals.
DS2001-0145
2001
Dragunov, V.I.Bulin, N.K., Bulina, L.V., Dragunov, V.I.Deep extension zones beneath the Siberian platformDoklady Academy of Sciences, Vol. 381, No. 8, Oct/Nov. pp. 901-5.Russia, SiberiaTectonics, lineaments
DS1995-1513
1995
Drahovzal, J.Potter, C.J., Goldhaber, M.B., Heigold, P.C., Drahovzal, J.Structure of the Reelfoot Rough Creek Rift System, Fluorspar area fault complex and Hicks Dome...United States Geological Survey (USGS) Prof. paper, No. 1538- Q, 20p.Midcontinent, Illinois, KentuckyGeophysics - seismics
DS1992-0390
1992
Drahovzal, J.A.Drahovzal, J.A., Harris, D.C., Wickstrom, L.H., Walker, D.The East continent rift basin: a new discoveryIndiana Publishing Cincinnati Arch Consortium Special Report, No. 52, 25pIndiana, Kentucky, OhioStructure, Rift Basin
DS1992-0884
1992
Drahovzal, J.A.Kolata, D.R., Keith, B.D., Drahovzal, J.A.Illinois Basin consortium program planIllinois Basin Series, 21pGlobalStructure, Kankakee Arch, Cincinnati Arch, New Madrid zone
DS1994-0773
1994
Drake, M.J.Hillgren, V.J., Drake, M.J., Rubie, D.C.high pressure and high temperature experiments on core mantle segregation in the accreting earth.Science, Vol. 264, No. 5164, June 3, pp. 1442-1444.MantleBlank
DS1996-0631
1996
Drake, M.J.Hillgren, V.J., Drake, M.J., Rubie, D.C.high pressure and high temperature metal silicate partitioning of siderophile elements: composition..Geochimica et Cosmochimica Acta, Vol. 60, No. 12, June pp. 2257-2263MantleSilicate liquid composition, Siderophile Metal partioning
DS2002-0403
2002
Drake, M.J.Drake, M.J., Righter, K.Determining the composition of the EarthNature, No. 6876, March 7, pp. 39-44.MantlePetrology
DS200612-0378
2006
Drake, M.J.Ertel, W., Walter, M.J., Drake, M.J., Sylvester, P.J.Experimental study of platinum solubility in silicate melt to 14 GPa and 2273 K: implications for accretion and core formation in Earth.Geochimica et Cosmochimica Acta, Vol. 70, 10, May 15, pp. 2591-2602.MantleMetasomatism - platinum, accretion, boundary
DS1985-0383
1985
Drake, R.Larson, E.E., Patterson, P.E., Curtis, G., Drake, R., Mutschler.Petrologic, Paleomagnetic, and Structural Evidence of a Paleozoic Rift System in Oklahoma, New Mexico, Colorado, and Utah.Geological Society of America (GSA) Bulletin., Vol. 96, No. 11, NOVEMBER PP. 1364-1372.United States, Gulf Coast, Colorado Plateau, Oklahoma, New Mexico, ColoradoGeotectonics
DS1994-0127
1994
Drake, R.E.Beck, M.E., Burmester, R.R., Drake, R.E., Riley, P.D.A tale of two continents: some tectonic contrasts between the Central Andes and the North America Cordillera as illustrated by their paleomagneticsignaturesTectonics, Vol. 13, No. 1, February pp. 215-Cordillera, Andes, ChileTectonics, Geophysics -paleomagnetics
DS200412-0515
2003
Drakopoulos, M.El Goresy, A., Dubrovinsky, L.S., Gillet, P., Mostefaoul, S., Graup, G., Drakopoulos, M., Simionovici, A.S.A new natural super hard transparent polymorph of carbon from the Popigai impact crater, Russia.Comptes Rendus Geoscience, Vol. 335, 12, Oct. pp. 889-898.RussiaLonsdaleite, graphite, mineralogy
DS201412-0222
2003
Drakopoulos, M.El Goresy, A., Dubrovinsky, L.S., Gillet, P., Mostefaoui, S., Graup, G., Drakopoulos, M., Simionovici, A.S., Swamy, V., Masaitis, V.L.A new natural, super-hard, transparent polymorph of carbon from the Popigai impact crater, Russia.Comptes Rendus Geoscience, Vol. 335, pp. 889-898.Russia, YakutiaMeteorite
DS201012-0171
2010
Dransfield, M.Dransfield, M.Conforming Falcon gravity with the global gravity anomaly.Geophysical Prospecting, Vol. 58, 3, pp. 468-483.Africa, South Africa, AustraliaTechnology - not specific to diamonds
DS201012-0172
2010
Dransfield, M.Dransfield, M., Le Roux, T., Burrows, D.Airborne gravimetry and gravity gradiometry at Fugro airborne surveys.Australian Airborne Gravity Conference Extended Abstracts 2010, pp. 49-52.Canada, Northwest TerritoriesGeophysics - gravity, Ekati
DS1994-0451
1994
Dransfield, M.H.Dransfield, M.H., Buckingham, M.J., Van Kann, F.J.Lithological mapping by correlating magnetic and gravity gradient airbornemeasurementsExploration Geophysics, Australian Bulletin, Vol. 25, No. 1, March pp. 25-30GlobalGeophysics -gravity, Lithology
DS201901-0029
2018
Dransfield, M.H.Dransfield, M.H., Chen, T.Heli-borne gravity gradiometry in rugged terrain. (mentions Margaret Lake)Geophysical Prospecting, doi.org/10.1111/1365-2478.12736 Canada, Northwest Territoriesgeophysics
DS201907-1541
2019
Dransfield, M.H.Dransfield, M.H., Chen, T.Heli-borne gravity gradiometry in rugged terrain ( mentions Margaret Lake)Geophysical Prospecting, Vol. 67, 6, pp. 1626-1636.Global, Canada, Northwest Territoriesgeophysics - graviometry

Abstract: For airborne gravity gradiometry in rugged terrain, helicopters offer a significant advantage over fixed?wing aircraft: their ability to maintain much lower ground clearances. Crucially, this provides both better signal?to?noise and better spatial resolution than is possible with a fixed?wing survey in the same terrain. Comparing surveys over gentle terrain at Margaret Lake, Canada, and over rugged terrain at Mount Aso, Japan, demonstrates that there is some loss of spatial resolution in the more rugged terrain. The slightly higher altitudes forced by rugged terrain make the requirements for terrain correction easier than for gentle terrain. Transforming the curvature gradients measured by the Falcon gravity gradiometer into gravity and the complete set of tensor components is done by a Fourier method over gentle terrain and an equivalent source method for rugged terrain. The Fourier method is perfectly stable and uses iterative padding to improve the accuracy of the longer wavelengths. The equivalent source method relies on a smooth model inversion, and the source distribution must be designed to suit the survey design.
DS1860-1028
1898
Draper, D.Draper, D.Note on the Diamonds at Rietfontein Farm, PremierGeological Society of South Africa Transactions, Vol. 3, PP. 87-88.Africa, South Africa, TransvaalAlluvial placers
DS1860-1029
1898
Draper, D.Draper, D., Frames, M.E.The Diamond (1898)Johannesburg: Mathews And Walker., 40P.Africa, South AfricaProspecting
DS1860-1080
1899
Draper, D.Draper, D.Notes on the Paper by Alison Entitled Origin and Formation Of Pans #2Geological Society of South Africa Transactions, Vol. 4, PP. 169-170.Africa, South AfricaGeomorphology
DS1860-1081
1899
Draper, D.Draper, D., Frames, M.E.On the Diamond Pipes of the South African RepublicGeological Society of South Africa Transactions, Vol. 4, PT. 1, P. 5. P. 34.Africa, South AfricaGeology
DS1900-0318
1905
Draper, D.Draper, D.Early Discoveries of DiamondsSouth Africa Mines Commerce and Industry, Vol. 2, Feb. 4TH. P. 1051, ALSO: Engineering and Mining Journal, Vol. 79, PAfrica, South AfricaHistory, Kimberley, Premier, Mines
DS1910-0178
1911
Draper, D.Draper, D.The Diamond Fields of BrasilMining Engineering Journal of South Africa, Vol. 9, PT. 1, MARCH 18TH. No. 419, P. 50.BrazilGeology, History, Genesis
DS1910-0271
1912
Draper, D.Draper, D.Origin of Alluvial DiamondsSouth African Mining Journal 21ST. ANNIVERSARY VOLUME., Vol. 21A, PP. 53-57.South AfricaDiamond Genesis, Alluvial Diamond Placers
DS1910-0272
1912
Draper, D.Draper, D.What South Africa Owes to the GeologistMining Engineering Journal of South Africa, Vol. 10, PT. 1, AUGUST 24TH. P. 962.South AfricaHistory
DS1910-0273
1912
Draper, D.Draper, D.Earliest Discoveries of Diamonds in Cape Colony and TransvaaSouth African Mining Journal 21ST. ANNIVERSARY VOLUME., Vol. 21A, PP. 99-101.South AfricaHistory
DS1910-0463
1915
Draper, D.Draper, D.Discussion on the Paper by Macgregor Entitled Notes on a Graphic Intergrowth of Diopside and Ilmenite from the Bembesi Diamond Field, Southern Rhodesia.Geological Society of South Africa Proceedings, Vol. 18, P. XXXVI.ZimbabweOxide-silicate-intergrowths, Mineralogy
DS1910-0497
1916
Draper, D.Draper, D.Discussion on the Paper by E.h.l. Schwarz Entitled Diamonds from the Molteno Beds.Geological Society of South Africa Proceedings, PP. 39-40.South Africa, Griqualand WestGeology, Genesis
DS1920-0028
1920
Draper, D.Draper, D.Important Diamondiferous Discovery in BrasilMining Engineering Journal of South Africa, Vol. 29, PT. 2, APRIL 24TH. No. 1491, P. 177.BrazilHistory, Deposits, Industry
DS1920-0151
1923
Draper, D.Draper, D.Brazilian Diamonds, 1923Mining Engineering Journal of South Africa, Vol. 33, PT. 2, No. 1634, P. 527.BrazilCurrent Activities
DS1920-0280
1926
Draper, D.Draper, D.Lichtenburg and Diamond GeologyMining Engineering Journal of South Africa, Vol. 37, PT. 1, P. 696.South AfricaDiamond Genesis
DS1920-0329
1927
Draper, D.Draper, D.The Evolution of Diamond Mining and Winning Machinery in South Africa.Mining Engineering Journal of South Africa, Vol. 38, PT. 2, Dec. 10TH. No. 1889, PP. 383-384. ALSO: No.South AfricaHistory, Diamond Mining, Diamond Recovery
DS1920-0330
1927
Draper, D.Draper, D.On the Occurrence of Diamonds Associated with the Chert Beds of the Dolomite Series in the Districts of Ventersdorp Andlichtenburg.Geological Society of South Africa Transactions, Vol. 30, PP. 57-68.South Africa, TransvaalGeology, Alluvial Diamond Placers
DS1920-0376
1928
Draper, D.Draper, D.Reply to the Discussion on His Paper "on the Association Of diamonds with the Chert Beds".Geological Society of South Africa Proceedings, Vol. 31, PP. 42-48.South AfricaGeology, Alluvial Diamond Placers
DS1920-0377
1928
Draper, D.Draper, D.The Western Transvaal Diamond and Emerald Areas. D. Draper Replies Effectively to H.s. Harger's Criticism of His Views.geological Authorities Found Ranged Against the Critic.Mining Engineering Journal of South Africa, Vol. 38, PT. 2, Feb. 11TH. No. 1898, P. 643; No. 1899, Feb.South Africa, TransvaalAlluvial Diamond Placers, Lichtenburg
DS1920-0437
1929
Draper, D.Draper, D.The Diamond Industry of South Africa, Part 2Mining Engineering Journal of South Africa, Vol. 40, No. 1990 P. 304; No. 1993 PP. 385-386; No. 1995 PP.South AfricaDiamond Genesis
DS1920-0438
1929
Draper, D.Draper, D.The Birth of the Diamond Industry in South Africa. Early Discovery, Pioneers, Rules and Regulations and Life on the Diggings.Mining Engineering Journal of South Africa, Vol. 40, AUG. 10TH. No. 1976, PP. 675-677.South AfricaHistory
DS200612-0358
2006
Draper, D.A.Dwarzski, R.E., Draper, D.A., Shearer, C.K., Agee, C.B.Experimental insights on crystal chemistry of high Ti garnets from garnet melt partitioning of rare earth and high field strength elements.American Mineralogist, Vol. 91, 9, pp. 1536-1546.TechnologyPetrology - crystal chemistry
DS1991-0399
1991
Draper, D.S.Draper, D.S.Spinel lherzolite nodules from Simcoe volcano, southeastern Washington:first mantle xenoliths from the Pacific NorthwestEos Transactions, Vol. 72, No. 44, October 29, abstract p. 517GlobalLherzolite, Mantle xenoliths
DS1992-0391
1992
Draper, D.S.Draper, D.S.Spinel lherzolite xenoliths from Lorena Butte, Simcoe Mountains, southern Washington (USA)Journal of Geology, Vol. 100, No. 6, November pp. 766-776GlobalMantle, Xenoliths
DS1994-0274
1994
Draper, D.S.Carroll, M.R., Draper, D.S.Noble gases as trace elements in magmatic processesChemical Geology, Vol. 117, pp. 37-56GlobalGeochemistry, Noble gases
DS1996-0166
1996
Draper, D.S.Brandon, A.D., Draper, D.S.Contraints on the origin of the oxidation state of mantle overlying subduction zones: an example from Simcoe Washington, USAGeochimica et Cosmochimica Acta, Vol. 60, No. 10, pp. 1739-49.GlobalTectonics - subduction
DS1996-0381
1996
Draper, D.S.Draper, D.S.The effect of slab derived hydrous fluids on the oxidation state ofmantle...Cascade Arc.Geological Society of Australia 13th. Convention held Feb., No. 41, abstracts p.116.GlobalSlab subduction, Mantle
DS1996-0382
1996
Draper, D.S.Draper, D.S.Experimental P-T phase relations of silicic, alkaline, aluminous glasses trapped in mantle xenoliths.Geological Society of Australia 13th. Convention held Feb., No. 41, abstracts p.117.MantleXenoliths
DS1999-0174
1999
Draper, D.S.Draper, D.S., Green, T.H.P - T phase relations of silicic, alkaline, aluminous liquids: new result sand applications to mantle meltingEarth and Planetary Science Letters, Vol. 170, No. 3, July 15, pp. 255-68.MantleMelt - alkaline rocks, Metasomatism
DS1999-0175
1999
Draper, D.S.Draper, D.S., Green, T.H.P T phase relations of silicic alkaline, aluminous liquids: new results and apllications to mantle meltingEarth and Planetary Science Letters, Vol. 170, No. 3, July 15, pp. 215-39.MantleMetasomatism
DS201708-1629
2017
Draper, J.C.M.Draper, J.C.M.Ilmenite generations in orangeite from Banankoro, Guinea: implications for exploration.11th. International Kimberlite Conference, PosterAfrica, Guineadeposit - Banankoro
DS2002-0404
2002
Draut, A.E.Draut, A.E., Clift, P.D., Hannigan, R.E., Layne, G., Shimizu, N.A model for continental crust genesis by arc accretion: rare earth element evidence from the Irish Caledonides.Earth and Planetary Science Letters, Vol. 203, 3-4, pp. 861-877.Ireland, ScandinaviaOrogenesis - REE
DS1982-0616
1982
Dravin, V.A.Vavilov, V.S., Gippius, A.A., Dravin, V.A., Zajeev, A.M., Zakup.Cathodluminescence of Natural Diamond Associated with Implanted Impurities.Soviet Physics of Semi-conductors, Vol. 16, No. 11, PP. 1288-1290.RussiaBlank
DS1860-0628
1889
Drayson, A.W.Drayson, A.W.The Diamond Hunters of South AfricaLondon: Griffiths, Farran, Okeden, Welsh, FIRST EDITION, 383P.Africa, South AfricaTravelogue
DS1900-0020
1900
Drayson, A.W.Drayson, A.W.Early Days Amongst the Boers Or, the Diamond Hunters of South Africa.London: Griffiths, Farran, Okeden, Welsh, 383P.Africa, South AfricaTravelogue, Kimberley
DS1999-0359
1999
DredgeKerr, D.E., Kjarsgaard, Knight, Dredge, StirlingRegional distribution and chemistry of kimberlite indicator minerals, northern Contwoyto Lake map area.Geological Survey of Canada (GSC) Open file, No. 3768, 34p. $ 14.00 plus Disc $ 20.00Northwest Territories, NunavutGeochemistry - indictor minerals, Contwoyto Lake area 76E, Tahera
DS1994-1881
1994
Dredge, L.Ward, B., Dredge, L., Kerr, D.Till geochemistry Lac de Gras, District of MackenzieGeological Survey of Canada Open File, No. 2868, 1 disc. $ 15.00Northwest TerritoriesGeochemistry -till, Lac de Gras
DS1994-1883
1994
Dredge, L.Ward, B.C., Kjarsgaard, B., Kerr, D., Dredge, L.Distribution of kimberlite indicator minerals in the Lac de Gras regionNorthwest Territories 1994 Open House Abstracts, p. 61-62. abstractNorthwest TerritoriesGeochemistry
DS2001-1114
2001
Dredge, L.St. Onge, M.R., Corrigan, D., Dredge, L., Scott, D.J.An overview of the multidisciplinary central Baffin Project29th. Yellowknife Geoscience Forum, Nov. 21-23, abstract p. 82-3.Northwest Territories, NunavutGeology - not specific to diamonds
DS1989-0384
1989
Dredge, L.A.Dyke, A.S., Dredge, L.A.Quaternary geology of the northwestern Canadian ShieldGeological Survey of Canada (GSC) DNAG, Quat Geol., No. 1, pp. 189-214.Northwest TerritoriesGeomorphology
DS1990-0426
1990
Dredge, L.A.Dredge, L.A.The Melville Moraine: sea level change and response of the western Margin of the Foxe Ice Dome, Melville Pen.Canadian Journal of Earth Sciences, Vol. 27, pp. 1215-24.Northwest Territories, Melville PeninsulaGeomorphology
DS1992-0392
1992
Dredge, L.A.Dredge, L.A.Field guide to the Churchill region, Manitoba. Glaciations, sea levelchanges, permafrost, landforms and archeology of the Churchill and GillamareasGeological Survey Canada Miscellaneous Report, miscellaneous Report No. 53, 51pManitobaGeomorphology, Field guide
DS1993-0375
1993
Dredge, L.A.Dredge, L.A.Glaciotectonic structures in eastern and Arctic CanadaGeological Survey of Canada, Open file, No. 2660, 55pNorthwest Territories, ArcticGeomorphology, Open File -ad
DS1993-1696
1993
Dredge, L.A.Ward, B.C., Dredge, L.A., Kerr, D.E., Dilabio, R.N.W.Glacial geology and implications for drift prospecting in the Lac de Gras area (76C, D, 86A) northwest Territories.Northwest Territories Exploration Overview for 1993, November pp. 54.Northwest TerritoriesGlacial, Drift prospecting
DS1994-0453
1994
Dredge, L.A.Dredge, L.A., Kerr, D., Ward, B.C., Dilabio, R.M.W.Drift prospecting and surficial geology in the Lac de Gras NTS 76C, 76 86A) Northwest Territories.Geological Survey of Canada Open Forum January 17-19th. Abstracts only, p. 14.Northwest TerritoriesGeomorphology, Drift prospecting
DS1994-0454
1994
Dredge, L.A.Dredge, L.A., Ward, B., Kerr, D.Till geochemistry Aylmer Lake, District of MackenzieGeological Survey of Canada Open File, No. 2867, 1 disc. $ 15.00Northwest TerritoriesGeochemistry -till, Aylmer Lake
DS1994-0455
1994
Dredge, L.A.Dredge, L.A., Ward, B.C., Kerr, D.E.Glacial geology and implications for drift prospecting in the Lac de @Winter Lake, and Aylmer Lake map areas, Northwest Territories.Geological Survey of Canada Current Research, No. 1994, C, pp. 33-38.Northwest TerritoriesGeomorphology, Lac de Gras
DS1994-0456
1994
Dredge, L.A.Dredge, L.A., Ward, B.C., Kerr, D.E.Glacial geology and implications for drift prospecting in the Lac de Gras Winter Lake area, Aylmer Lake maps.Geological Survey of Canada (GSC) Paper, No. 1994-C, pp. 33-38.Northwest TerritoriesGeomorphology, Winter, Aylmer
DS1994-1882
1994
Dredge, L.A.Ward, B.C., Dredge, L.A., Kerr, K.E.Ice flow indicators, Winter Lake, Lac de Gras, and Aylmer Lake District ofMackenzie.Geological Survey of Canada Open file, No. 2808, 1 map, 1: 250, 000 $ 15.00Northwest TerritoriesGeomorphology, Open file
DS1995-0440
1995
Dredge, L.A.Dredge, L.A., Kjarsgaard, B.A., Ward, B.C., Kerr, StirlingDistribution and chemistry of kimberlite indicator minerals, Winter Lake map area. 86A.Geological Survey of Canada Open File, No. 3081, 78p. 1 disk. $ 34.00Northwest TerritoriesGeochemistry, Winter Lake area
DS1995-0941
1995
Dredge, L.A.Kerr, D.E., Dredge, L.A., Ward, B.C., Gebert, J.Quaternary geology and implications for drift prospecting Napaktulik @Point Lake and ContwyotoGeological Survey of Canada (GSC) Paper, No. 1995-E, pp. 201-9.Northwest TerritoriesGeomorphology
DS1995-2029
1995
Dredge, L.A.Ward, B.C., Kerr, D.E., Dredge, L.A.Distribution of kimberlite indicator minerals in till, Lac de Gras regionGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) Annual Meeting Abstracts, Vol. 20, p. A109 AbstractNorthwest TerritoriesGeochemistry, geomorphology, Till sampling
DS1995-2030
1995
Dredge, L.A.Ward, B.C., Kjarsgaard, B.M., Dredge, L.A., Kerr, StirlingDistribution and chemistry of kimberlite indicator minerals Lac de Gras area (76D).Geological Survey of Canada Open File, No. 3079, 161p. 1 disc. $ 43.00Northwest TerritoriesGeochemistry, Deposit -Lac de Gras area
DS1996-0383
1996
Dredge, L.A.Dredge, L.A., Kjarsgaard, B.M., Ward, B.C., Kerr, D.E.Distribution and geochemistry composition of kimberlite indicator Point Lake map area, northwest Territories 86H.Geological Survey of Canada Open File, No. 3341, 21p. and disc total 21.50Northwest TerritoriesGeochemistry, Deposit - Point Lake map area
DS1996-0384
1996
Dredge, L.A.Dredge, L.A., Ward, B.C., Kerr, D.E.Quaternary geology Aylmer Lake areaGeological Survey of Canada (GSC) Map, Map No. 1867A, 1:125, 000Northwest TerritoriesGeomorphology
DS1996-0385
1996
Dredge, L.A.Dredge, L.A., Ward, B.C., Kerr, D.E.Morphology and kelphite preservation on glacially transported pyropegrains.Geological Survey of Canada, LeCheminant ed, OF 3228, pp. 197-203.Northwest TerritoriesPetrology -garnet, kelphite, Lac de Gras area
DS1996-0730
1996
Dredge, L.A.Kerr, D., Ward, B.C., Dredge, L.A.Ice flow patterns and drift exploration for kimberlites in northern SlaveProvince.Geological Survey of Canada Colloquium, Jan. 22-24th., Poster display onlyNorthwest TerritoriesExploration, Geomorphology
DS1996-0731
1996
Dredge, L.A.Kerr, D.E., Dredge, L.A., Ward, B.C.Trace element geochemistry and gold grain results from till samples, WinterLakearea, northwest Territories.Geological Survey of Canada Open File, No. 3206, 137p. $ 43.00 paper and discNorthwest TerritoriesGeochemistry -Gold, Geomorphology, alluvial, till
DS1996-0732
1996
Dredge, L.A.Kerr, D.E., Kjarsgaard, I.M., Dredge, L.A., Ward, StirlingDistribution and composition of kimberlite indicator minerals, Napaktulik Lake map area, northwest Territories 86I.Geological Survey of Canada Open File, No. 3355, 34p. 1 disc. $ 30.00Northwest TerritoriesGeochemistry, Kimberlite indicator minerals
DS1996-1506
1996
Dredge, L.A.Ward, B.C., Dredge, L.A., Kerr, D.E.Surficial geology Contwyoto Lake areaGeological Survey of Canada (GSC) Open File, No. 3200, map 1: 125, 000Northwest TerritoriesGeomorphology
DS1996-1507
1996
Dredge, L.A.Ward, B.C., Dredge, L.A., Kerr, D.E., Kjarsgaard, B.A.Kimberlite indicator minerals in glacial deposits, Lac de Gras area, N.W.T.Geological Survey of Canada, LeCheminant ed, OF 3228, pp. 191-195.Northwest TerritoriesGeomorphology, Lac de Gras area
DS1997-0290
1997
Dredge, L.A.Dredge, L.A., Kerr, D.E., Kjarsgaard, B.M., Knight, WardSlave NATMAP kimberlite indicator minerals in till, Slave ProvinceGeological Survey of Canada Forum 1997 abstracts, p. 26. AbstractNorthwest TerritoriesGeochemistry, Till
DS1997-0291
1997
Dredge, L.A.Dredge, L.A., Kerr, D.E., Kjarsgaard, L.M., Knight, WardKimberlite indicator minerals in till, central Slave Province, NorthwestTerritories.Geological Survey of Canada Open File, No. 3426, 1 poster $ 20.00Northwest TerritoriesGeochemistry, Poster
DS1997-0292
1997
Dredge, L.A.Dredge, L.A., Kerr, D.E., Ward, B.C.Slave NATMAP: a project summary of the surficial geology componentGeological Survey of Canada Forum 1997 abstracts, p. 19. AbstractNorthwest TerritoriesSlave Province, NATMAP, quaternary, surficial
DS1997-0588
1997
Dredge, L.A.Kerr, D.E., Dredge, L.A., et al.Kimberlite indicator minerals in till, Central Slave Province, northwest Territories CanadaExploration 97, Proceedings, pp. 359-362. Poster abstractNorthwest TerritoriesGeochemistry, Geomorphology, Glacial
DS1997-0590
1997
Dredge, L.A.Kerr, D.E., Wolfe, S.A., Dredge, L.A.Surficial geology, Contwoyto Lake, District of Mackenzie, NorthwestTerritories.Geological Survey of Canada Open File, No. 3459, $ 22.40Northwest TerritoriesGeology - surficial
DS1997-0591
1997
Dredge, L.A.Kerr, D.E., Wolfe, S.A., Dredge, L.A.Surficial geology of the Contwoyto Lake map area (north half) District ofMackenzie.Geological Survey of Canada Current Research, No. 1997-C, pp. 51-60.Northwest TerritoriesGeomorphology, Contwoyto Lake area
DS1997-1227
1997
Dredge, L.A.Ward, B.C., Dredge, L.A., Kerr, D.E.Surficial geology Lac de Gras areaGeological Survey of Canada (GSC) Map, No. 1870A, map 1:125, 000Northwest TerritoriesGeomorphology
DS1997-1228
1997
Dredge, L.A.Ward, B.C., Dredge, L.A., Kerr, D.E.Till geochemistry and gold grain results, southern Contwyoto Lake map area76 E 1-8, 12, 13.Geological Survey of Canada (GSC) Open File, No. 3387Northwest TerritoriesGeomorphology
DS1998-0739
1998
Dredge, L.A.Kerr, D.E., Dredge, L.A., McClenaghan, M.B.Kimberlite indicator minerals in till, Lac de Gras area, NorthwestTerritories.Explore, No. 100, Aug. pp. 1, 3-6, 8-11.Northwest TerritoriesGeochemistry, till, Lac de Gras area
DS1998-0740
1998
Dredge, L.A.Kerr, D.E., Knight, R.D., Dredge, L.A.Till geochemistry and gold grain results, Contwyoto Lake map area, 76 E north half.Geological Survey of Canada (GSC) Open File, No. 3654, 120p.Northwest TerritoriesGeochemistry
DS1999-0176
1999
Dredge, L.A.Dredge, L.A.Glacial dispersion patterns and Post glacial marine overlap in the Longstaff Bluff area Baffin Island.Geological Survey of Canada (GSC), Current Research 1999- C, pp. 1-8.Northwest Territories, Baffin IslandGeomorphology
DS2002-1030
2002
Dredge, L.A.McClenaghan, M.B., Ward, B.C., Kjarsgaard, B.A., Kerr, D.E., Dredge, L.A.Indicator minerals and till geochemical dispersal patterns associated with the RanchGeochemistry, Exploration, Environment, Analysis, Vol. 2, No. 4, pp. 299-319.Northwest TerritoriesGeochemistry, Deposit - Ranch Lake
DS200412-0482
2004
Dredge, L.A.Dredge, L.A.Till geochemistry results eastern Baffin Island, Nunavut. 37A, 37D, 27B, 27C.Geological Survey of Canada Open File, No. 4543, 1 CD $ 26. 222p.Canada, NunavutGeochemistry - not specific to diamonds
DS200612-0351
2006
Dredge, L.A.Dredge, L.A., McMartin, I., Kjarsgaard, I.M.Kimberlite indicator minerals in till from the Wager Bay area, maIn land Nunavut: dat a and interpretation NTS 56 G.Geological Survey of Canada, Open file 5087, 1 CD 48p. $ 25.00Canada, NunavutGeochemistry
DS200612-0352
2006
Dredge, L.A.Dredge, L.A., Pehrsson, S.J.Geochemistry and physical properties of till in northern most Manitoba.Geological Survey of Canada, Open file 5320, 134p. $ 9.10Canada, ManitobaGeochemistry - till not specific to diamonds
DS200612-0353
2006
Dredge, L.A.Dredge, L.A., Robertson, L.Ice flow and recessional ice margin indicators, central Baffin Island, Nunavut.Geological Survey of Canada, No. 5341, 1 CD $ 9.10Canada, NunavutGeomorphology
DS1994-0452
1994
Dredge Mitchelmore, M.Dredge Mitchelmore, M., Cook, F.A.Inversion of the Proterozoic Wernecke Basin during tectonic development Of the Racklan OrogenCanadian Journal of Earth Sciences, Vol. 31, No. 3, March pp. 447-457Northwest TerritoriesTectonics, Wernecke Basin
DS1860-0292
1878
Dree, Marquis E.G.De.Dree, Marquis E.G.De.Voyage Aux Mines de Diamants dans le Sud de l'afrique (d'apres Les Notes de Mde. P. Macpatrickson.) Vaal River Tour Du Monde (paris), Vol. 36, PP. 289-336.Africa, South AfricaTravelogue
DS2000-0265
2000
DreherEichelberger, J.C., Chertkoff, D.G., Dreher, NyeMagmas in collision: rethinking chemical zonation in silicic magmasGeology, Vol. 28, No. 7, July, pp. 603-6.GlobalMagmatism - differentiation, calderas
DS200612-0840
2006
Dreher, S.T.Luguet, A., Nowell, G.M., Pearson, D.G., Dreher, S.T.186 Os and 187 Os signatures of pyroxenites and the core mantle interaction debate.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 35, abstract only.MantleGeochronology
DS1992-0358
1992
Dreibus, G.Deruelle, B., Dreibus, G., Jambon, A.Iodine abundances in oceanic basalts: implications for earth dynamicsEarth and Planetary Science Letters, Vol. 108, No. 4, February pp. 217-228GlobalGeochemistry, Oceanic basalts
DS1995-0441
1995
Dreibus, G.Dreibus, G., Brey, G., Girnis, A.The role of carbon dioxide in the generation and emplacement of kimberlitemagmas: new exp. dat a on CO2Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 138-40.GlobalPetrology -experimental -CO2, Kimberlite magmas
DS1995-0442
1995
Dreibus, G.Dreibus, G., Jagoutz, E., Wanke, H.Water in the earth's mantleProceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 141-2.MantleAccretion model -water
DS1996-0386
1996
Dreibus, G.Dreibus, G., Palme, H.Cosmochemical constraints on the sulphur content of the Earth's coreGeochimica Et Cosmochimica Acta, Vol. 60, No. 7, pp. 1125-30.MantleDensity - core
DS1999-0286
1999
Dreibus, G.Handler, M.R., Bennett, V.C., Dreibus, G.Evidence from correlated Ir Os and copper S for late stage mobility inperidotite xenoliths: implications Rhenium- Osmium (Re-Os)Geology, Vol. 27, No. 1, Jan. pp. 75-78.Australia, mantleXenoliths, Geochemistry
DS2003-0640
2003
Dreibus, G.Jagoutz, E., Dreibus, G.On the search for 142 Nd in terrestrial rocks8 Ikc Www.venuewest.com/8ikc/program.htm, Session 4, AbstractSouth Africa, Russia, SiberiaMantle geochemistry, Lherzolitic nodules
DS200412-0874
2003
Dreibus, G.Irvine, G.J., Pearson, D.G., Kjarsgaard, B.A., Carlson, R.W., Kopylova, M.G., Dreibus, G.A Re Os isotope and PGE study of kimberlite derived peridotite xenoliths from Somerset Island and a comparison to the Slave andLithos, Vol. 71, 2-4, pp. 461-488.Africa, South Africa, Northwest Territories, NunavutGeochronology
DS200412-0897
2003
Dreibus, G.Jagoutz, E., Dreibus, G.On the search for 142 Nd in terrestrial rocks.8 IKC Program, Session 4, AbstractAfrica, South Africa, Russia, SiberiaMantle geochemistry Lherzolitic nodules
DS200412-1508
2004
Dreibus, G.E.Pearson, D.G., irvine, G.J., Ionov, D.A., Boyd, F.R., Dreibus, G.E.The Re Os systematics and platinum group element fractionation during mantle melt extraction: a study of massif and xenolith perChemical Geology, Vol. 208, 1-4, pp. 29-59.Africa, Lesotho, Namibia, MoroccoGeochronology, mantle melt extraction
DS1950-0326
1957
Dreimanis, A.Dreimanis, A.Heavy Mineral Studies in Tills of Ontario and Adjacent AreasJournal of SEDIMENT. PETROL., Vol. 27, PP. 148-161.Canada, OntarioGeochemistry
DS1960-0036
1960
Dreimanis, A.Dreimanis, A.The Great Lakes Diamonds. Fourth Report: Summary of Investigations and the Plum Creek and Saukville Areas.Department GEOL. University WESTERN ONTARIO, UNPUBL.United States, Great Lakes, WisconsinDiamond Occurrences
DS1975-1047
1979
Dreimanis, A.Gwyn, Q.H.J., Dreimanis, A.Heavy Mineral Assemblages in Tills and Their Use in Distinguishing Glacial Lobes in the Great Lakes Region.Canadian Journal of Earth Sciences, Vol. 16, No. 12, PP. 2219-2235.United States, Great LakesGeomorphology, Heavy Minerals, Geochemistry
DS1989-0634
1989
Dreimanis, A.Hicock, S.R., Dreimanis, A.Sunnybrook drift indicates a grounded early Wisconsin glacier in the Lake Ontario basinGeology, Vol. 17, No. 2, February pp. 169-172OntarioGeomorphology
DS1992-0393
1992
Dreimanis, A.Dreimanis, A.Early Wisconsi nan in the north central part of the Lake Erie Basin: a newinterpretationGeological Society of America, Special Paper No. 270, pp. 109-118OntarioGeomorphology, Glacial deposits
DS1992-0707
1992
Dreimanis, A.Hicock, S.R., Dreimanis, A.Deformation till in the Great Lakes region: implications for rapid flow along the south-central margin of the Laurentide Ice SheetCanadian Journal of Earth Sciences, Vol. 29, No. 7, July, pp. 1565-1579Ontario, Great LakesGeomorphology, Till, Laurentide Ice Sheet
DS1999-0177
1999
Dreimanis, A.Dreimanis, A.Need for three dimensional analysis of structural elements in glacial deposits determination movement....Gsa Mickelson And Attig, Glacial Processes, SP337, pp.59-67.GlobalGeomorphology - glaciotectonic
DS1995-1919
1995
Drenkard, S.Torgersen, T., Drenkard, S., Stute, M., et al.Mantle helium in ground waters of eastern North America: time and space constraints on sourcesGeology, Vol. 23, No. 8, August pp. 675-678GlobalHot spots, Tectonics
DS201905-1025
2019
Drenth, B.J.Drenth, B.J., Grauchm V.J.S.Finding the gap in America's magnetic maps. ( Apr. 16, 2019)EOS, https://spaces.hightail. com/receive/ 2jvDHdtWRrUnited States, Arkansas, Missouri, Tennesseegeophysics, magnetic
DS202008-1385
2020
Drenth, B.J.Drenth, B.J., Souders, A.K., Schulz, K.J., Feinberg, J.M., Anderson, R.R., Chandler, V.W., Cannon, W.L., Clark, R.J.Evidence for a concealed Midcontinent Rift related northeast Iowa intrusive complex.Precambrian Research, in press available, 43p. PdfUnited States, Iowageophysics - seismics

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

Abstract: Large amplitude aeromagnetic and gravity anomalies over a ~9500 km2 area of northeast Iowa and southeast Minnesota have been interpreted to reflect the northeast Iowa intrusive complex (NEIIC), a buried intrusive igneous complex composed of mafic/ultramafic rocks in the Yavapai Province (1.8-1.7 Ga). Hundreds of meters of Paleozoic sedimentary cover and a paucity of basement drilling have prevented detailed studies of the NEIIC. Long considered, but not proven, to be related to the ~1.1 Ga Midcontinent Rift System (MRS), the NEIIC is comparable in areal extent to the richly mineralized Duluth Complex and is similarly located near the margin of the MRS. New geochronological and geophysical data together support an MRS affinity for the NEIIC. A dike swarm imaged in aeromagnetic data is cut by intrusions of the NEIIC, and a new apatite U-Pb date of ~1170 Ma on one of the dikes thus represents a maximum age for the NEIIC. A minimum age constraint is suggested by (1) large-volume magmatism associated with the MRS that was the last such event to affect the region; and (2) the presence of reversely magnetized dikes, similar in character to MRS-related dikes elsewhere, that cut several intrusions of the NEIIC. The NEIIC is largely characterized by the presence of multiple zoned intrusions, many of which contain large volumes of mafic-ultramafic rocks and have strong geophysical similarities to alkaline intrusive complexes elsewhere, including the MRS-related Coldwell Complex of Ontario. The largest of the zoned intrusions are ~40 km in diameter and are interpreted to have thicknesses of many kilometers. Suspected faults, alignments of intrusions, and intrusive margins tend to be aligned along northwest and northeast trends that match the trends of the Belle Plaine fault zone and Fayette structural zone, both previously interpreted as pre-MRS, possibly lithospheric-scale discontinuities that may have controlled NEIIC emplacement. These interpretations collectively imply notable potential for the NEIIC to host several different types of undiscovered base metal and critical mineral deposits.
DS1940-0170
1948
Dresch, J.Dresch, J.Aux Mines de Diamants de Congo Belge et D' AefMonde Col. Iii (paris), No. 225, PP. 83-85.GlobalDiamonds
DS1987-0771
1987
Dreschhoff, G.A.M.Voveney, R.M.Jr., Goebel, E.D., Zeller, E.J., Dreschhoff, G.A.M.Serpentinization and the origin of hydrogen gas in KansasAmerican Association of Petroleum Geologists (AAPG) Bulletin, Vol. 71, No. 1 Jan. pp. 39-48KansasMidcontinent, Tectonics
DS200812-0154
2008
Dresen, G.Burgmann, R., Dresen, G.Rheology of the Lower crust and Upper mantle: evidence from rock mechanics, geodesy and field observations.Annual Review of Earth and Planetary Sciences, Vol. 36, May, pp. 531-567.MantleRheology
DS1992-0394
1992
Dresselhaus, M.S.Dresselhaus, M.S.Fullerenes: down the straight and narrowNature, Vol. 358, No. 6383, July 16, p. 195GlobalFullerenes, Carbon
DS1910-0179
1911
Dresser, J.A.Dresser, J.A.Preliminary Report on the Serpentinites and Associated Rocks in Southern Quebec, Canada.Geological Survey of Canada (GSC), SUMMARY Report FOR 1910, PP. 208-219.Canada, QuebecGeology
DS1910-0345
1913
Dresser, J.A.Dresser, J.A.Preliminary Report on Serpentine and Associated Rocks Southern Quebec.Geological Survey of Canada MEMOIR., No. 22, 103P. PP. 83-84.Canada, QuebecBlank
DS1975-0070
1975
Dressler, B.Dressler, B.Lamprophyres of the North Central Labrador Trough, Quebec, CanadaNeues Jahrbuch f?r Mineralogie MONATSHEFTE., HEFT 6, PP. 268-280.Canada, QuebecRelated Rocks
DS1987-0162
1987
Dressler, B.O.Dressler, B.O., Morrison, G.G., Peredery, W.V., Rao, B.V.The Sudbury structure, Ontario, Canada- a ReviewBraunschweig Wiesbaden Vieweg, pp. 39-68OntarioSudbury, Impact structure
DS1995-0443
1995
Dressler, B.O.Dressler, B.O., Grieve, R.A.F., Sharpton, V.L.Large meteorite impacts and planetary evolutionGeological Society of America (GSA) Special Paper, No. 293, 358p. $ 100.00GlobalBook -ad, Meteorites
DS1996-1292
1996
Dressler, B.O.Sharpton, V.L., Dressler, B.O., et al.New constraints on the Slate Islands impact structure, Ontario. CanadaGeology, Vol. 24, No. 9, Sept. pp. 851-854.OntarioImpact structure, Slate Islands
DS2001-0270
2001
Dressler, B.O.Dressler, B.O., Reimold, W.U.Terrestrial impact melt rocks and glassesEarth Science Reviews, Vol. 56, No. 1-4, pp. 205-84.GlobalImpact craters, ring basins, Review
DS200412-0483
2004
Dressler, B.O.Dressler, B.O., Reimold, W.U.Order or chaos? Origin and mode of emplacement of breccias in floors of large impact structures.Earth Science Reviews, Vol. 67, 1-2, pp. 1-54.GlobalBreccia
DS1995-0444
1995
Drever, G.Drever, G., Matthews, R.Metallic and industrial mineral assessment report on the Alberta diamond project in the Hinton area.Alberta Geological Survey, MIN 1995005AlbertaExploration - assessment, Cameco Corp., Dia Met Minerals
DS1997-0922
1997
Drever, J.I.Prestud Anderson, S., Drever, J.I., Humphrey, N.F.Chemical weathering in glacial environmentsGeology, Vol. 25, No. 5, May pp. 399-402Canada, IndiaWeathering - glacial geomorphology, Geochemistry
DS1986-0193
1986
Drew, G.J.Drew, G.J.A geophysical case history of the AK1 lamproite pipeProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 454-456AustraliaArgyle, Diamond exploration -Geop
DS1994-0457
1994
Drew, G.J.Drew, G.J., Cowan, D.R.Geophysical signature of the Argyle lamproite pipe, western AustraliaUniversity of Western Australia, Publishing No. 26, pp. 393-402.AustraliaGeophysics, Deposit -Argyle
DS1990-0427
1990
Drew, L.J.Drew, L.J., Meng QingrunGeologic map of the Bayan Obo area, Inner Mongolia, ChinaUnited States Geological Survey (USGS) M.I. Map, No. 2057, 1: 50, 000 $ 3.10ChinaCarbonatite, Bayan Obo
DS1990-0428
1990
Drew, L.J.Drew, L.J., Meng Qingrun, Sun WiejunThe Bayan Obo iron-rare-earth-niobium deposits, Inner Mongolia, ChinaLithos, Special Issue, Vol. 25, No. 4, pp. 43-66ChinaRare earths, Carbonatite
DS1991-0400
1991
Drew, L.J.Drew, L.J. , Qingrun, M., Weijun, S.The geology of the Bayan Obo iron rare earths niobium deposits, InnerMongolia, ChinaAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME), Meeting to be held Feb. 25-28th. Denver, Colorado, AbstractChinaCarbonatite, Rare earths
DS1991-0401
1991
Drew, L.J.Drew, L.J., Qinrun, M., Weijun, S.The geology of the Bayan Obo iron-rare earth-niobium deposits, innerMongolia, ChinaAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint, No. 91-10, 14pChinaCarbonatite, Deposit -Bauan Obo
DS1995-0445
1995
Drew, L.J.Drew, L.J., Qinrun, M.Large scale structural geological setting of the Bayan Obo iron rare earth elements (REE)deposit, China.Global Tectonics and Metallogeny, Vol. 5, No. 1-2, Oct. pp. 33-36.China, MongoliaCarbonatite, rare earth elements (REE)., Deposit -Bayan Obo
DS201809-2109
2018
Drewitt, J.W.E.Walter, M.J., Drewitt, J.W.E., Thomson, A.R., Zhang, H., Lord, O.T., Heinen, B.The fate of carbonate in oceanic crust subducted into Earth's mantle.Goldschmidt Conference, 1p. AbstractMantlesubduction

Abstract: The H/C ratio in earth’s exosphere is higher than it is in the source region of primitive basalts, suggesting an enriched carbon reservoir in the mantle[1]. A plausible explanation is that subduction of carbon may have enriched the mantle in recycled carbon over time. Average basaltic crust contains ~ 2 wt.% CO2 [2], and modeling of slab devolatilisation suggests that subducted carbonate may survive to be transported deeper into the mantle [3]. Carbonated oceanic crust should melt in the transition zone along most subduction geotherms due to a deep trough in the carbonated basalt solidus, and mineral inclusions in superdeep diamonds testify to carbonate melt in their formation [4]. Along cool subduction geotherms carbonate may subduct into the lower mantle, potentially enriching the deep mantle in carbon. Here we report on laser-heated diamond anvil cell experiments in the CaO-MgO-SiO2-CO2 and FeO-MgO-SiO2-CO2 systems at lower mantle pressures where we investigate the stability of carbonate in oceanic crust, and test for decarbonation and diamond forming reactions involving carbonate and coexisiting free silica. We find that carbonate reacts with silica to form bridgmanite ± Ca-perovskite + CO2 at pressures in the range of ~50 to 70 GPa. These decarbonation reactions form an impenetrable barrier to subduction of carbonate into the deeper lower mantle, however, slabs may carry solid CO2 (Phase V) into the deeper lower mantle. We also identify reactions where carbonate or CO2 dissociate to form diamond plus oxygen. We suggest that the deep lower mantle may become enriched in carbon in the form of diamond over time due to subduction of carbonate and solid CO2 and its eventual dissociation to form diamond plus oxygen. Release of oxygen during diamond formation may also provide a mechanism for locally oxidizing the deep mantle.
DS201903-0503
2019
Drewitt, J.W.E.Drewitt, J.W.E., Walter, M.J., Zhang, H., McMahon, S.C., Edwards, D., Heinen, B.J., Lord, O.T., Anzellini, S., Kleppe, A.K.The fate of carbonate in oceanic crust subducted into Earth's lower mantle.Earth and Planetary Science Letters, Vol. 511, pp. 213-222.MantleBridgemanite

Abstract: We report on laser-heated diamond anvil cell (LHDAC) experiments in the FeO-MgO-SiO2-CO2 (FMSC) and CaO-MgO-SiO2-CO2 (CMSC) systems at lower mantle pressures designed to test for decarbonation and diamond forming reactions. Sub-solidus phase relations based on synthesis experiments are reported in the pressure range of ?35 to 90 GPa at temperatures of ?1600 to 2200 K. Ternary bulk compositions comprised of mixtures of carbonate and silica are constructed such that decarbonation reactions produce non-ternary phases (e.g. bridgmanite, Ca-perovskite, diamond, CO2-V), and synchrotron X-ray diffraction and micro-Raman spectroscopy are used to identify the appearance of reaction products. We find that carbonate phases in these two systems react with silica to form bridgmanite ±Ca-perovskite + CO2 at pressures in the range of ?40 to 70 GPa and 1600 to 1900 K in decarbonation reactions with negative Clapeyron slopes. Our results show that decarbonation reactions form an impenetrable barrier to subduction of carbonate in oceanic crust to depths in the mantle greater than ?1500 km. We also identify carbonate and CO2-V dissociation reactions that form diamond plus oxygen. On the basis of the observed decarbonation reactions we predict that the ultimate fate of carbonate in oceanic crust subducted into the deep lower mantle is in the form of refractory diamond in the deepest lower mantle along a slab geotherm and throughout the lower mantle along a mantle geotherm. Diamond produced in oceanic crust by subsolidus decarbonation is refractory and immobile and can be stored at the base of the mantle over long timescales, potentially returning to the surface in OIB magmas associated with deep mantle plumes.
DS1993-0376
1993
Drexel, J.F.Drexel, J.F.Brief mention of diamond..South Australia Geological Survey Bulletin, No. 54, Vol. 1, Precambrian, p. 100. very brief onlyAustraliaNews item, Diamond
DS1940-0148
1947
Dreyer, R.M.Dreyer, R.M.Magnetic Survey of the Bala Intrusive, Riley County, Kansas. #1Kansas Geological Survey Bulletin, No. 70, PT. 5, PP. 107-115.United States, Kansas, Central StatesKimberlite, Geophysics
DS1940-0149
1947
Dreyer, R.M.Dreyer, R.M.Magnetic Survey of the Bala Intrusive, Riley County, Kansas. #2Kansas Geological Survey Bulletin, No. 70, Report OF STUDIES, PT. 2, PP. 21-28; PT. 5, PP. 107-United States, Kansas, Central StatesKimberlite, Geophysics, Groundmag
DS1960-0337
1963
Dribble, C.D.Edwards, C.B., Dribble, C.D., Mcbride, B., Roger, T.H.Prospecting for Diamonds in Tanganyika 1959-1961United Nations Report, UNPUBL.Tanzania, East AfricaGeology
DS1999-0178
1999
Dricker, I.Dricker, I., Vinnik, L., Makeyeva, L.Upper mantle flow in eastern EuropeGeophysical Research Letters, Vol. 27, No. 9, May pp. 1219-22.EuropeGeophysics - seismics, Mantle flow, melting
DS1996-0387
1996
Dricker, I.G.Dricker, I.G., Roecker, Kosarev, VinnikShear wave velocity structure of the crust mantle beneath the KolaPeninsula.Geophysical Research. Lett., Vol. 23, No. 22, Nov. 15, pp. 3389-92.Russia, Kola PeninsulaGeophysics - seismics, Structure
DS1996-0388
1996
Dricker, I.G.Dricker, I.G., Roecker, S.W., Kosarev, G.L., Vinnik, L.P.Shear wave velocity structure of the crust and upper mantle beneath the Kola Peninsula.Geophysical Research. Letters, Vol. 23, No. 23, Nov. 15, pp. 3389-3392.Russia, Kola PeninsulaGeophysics - seismics, Mantle
DS2003-0351
2003
Dricker, I.G.Dricker, I.G., Roecker, S.W.Lateral heterogeneity in the upper mantle beneath the Tibetan plateau and itsJournal of Geophysical Research, Vol. 107, 11, Nov. 6, pp. DO1 10.1029/2001JB000797China, TibetGeophysics - seismics
DS200412-0484
2003
Dricker, I.G.Dricker, I.G., Roecker, S.W.Lateral heterogeneity in the upper mantle beneath the Tibetan plateau and its surroundings from SS-S travel time residuals.Journal of Geophysical Research, Vol. 107, 11, Nov. 6, pp. DO1 10.1029/2001 JB000797China, TibetGeophysics - seismics
DS201608-1418
2016
Driesner, T.Kueter, N., Soesilo, J., Fedortchouk, Y., Nestola, F., Belluco, L., Troch, J., Walle, M., Giuillong, M., Von Quadt, A., Driesner, T.Tracing the depositional history of Kalimantan diamonds by zircon provenance and diamond morphology studies. ( kimberlite or lamproite)Lithos, in press availableIndonesia, BorneoDeposit - Kalimantan

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

Abstract: Diamonds in alluvial deposits in Southeast Asia are not accompanied by indicator minerals suggesting primary kimberlite or lamproite sources. The Meratus Mountains in Southeast Borneo (Province Kalimantan Selatan, Indonesia) provide the largest known deposit of these so-called “headless” diamond deposits. Proposals for the origin of Kalimantan diamonds include the adjacent Meratus ophiolite complex, ultra-high pressure (UHP) metamorphic terranes, obducted subcontinental lithospheric mantle and undiscovered kimberlite-type sources. Here we report results from detailed sediment provenance analysis of diamond-bearing Quaternary river channel material and from representative outcrops of the oldest known formations within the Alino Group, including the diamond-bearing Campanian–Maastrichtian Manunggul Formation. Optical examination of surfaces of diamonds collected from artisanal miners in the Meratus area (247 stones) and in West Borneo (Sanggau Area, Province Kalimantan Barat; 85 stones) points toward a classical kimberlite-type source for the majority of these diamonds. Some of the diamonds host mineral inclusions suitable for deep single-crystal X-ray diffraction investigation. We determined the depth of formation of two olivines, one coesite and one peridotitic garnet inclusion. Pressure of formation estimates for the peridotitic garnet at independently derived temperatures of 930–1250 °C are between 4.8 and 6.0 GPa. Sediment provenance analysis includes petrography coupled to analyses of detrital garnet and glaucophane. The compositions of these key minerals do not indicate kimberlite-derived material. By analyzing almost 1400 zircons for trace element concentrations with laser ablation ICP-MS (LA-ICP-MS) we tested the mineral's potential as an alternative kimberlite indicator. The screening ultimately resulted in a small subset of ten zircons with a kimberlitic affinity. Subsequent U–Pb dating resulting in Cretaceous ages plus a detailed chemical reflection make a kimberlitic origin unfavorable with respect to the regional geological history. Rather, trace elemental analyses (U, Th and Eu) suggest an eclogitic source for these zircons. The age distribution of detrital zircons allows in general a better understanding of collisional events that formed the Meratus orogen and identifies various North Australian Orogens as potential Pre-Mesozoic sediment sources. Our data support a model whereby the majority of Kalimantan diamonds were emplaced within the North Australian Craton by volcanic processes. Partly re-deposited into paleo-collectors or residing in their primary host, these diamond-deposits spread passively throughout Southeast Asia by terrane migration during the Gondwana breakup. Terrane amalgamation events largely metamorphosed these diamond-bearing lithologies while destroying the indicative mineral content. Orogenic uplift finally liberated their diamond-content into new, autochthonous placer deposits.
DS200612-1490
2005
Drill, S.I.Vorontsov, A.V., Yarmolyuk, V.V., Kovalenko, V.I., Lykhin, D.A., Drill, S.I., Tatarnikov, S.A.Composition, sources and conditions of magmatism in the north Mongolia, Trans Baikal early Mesozoic rift zone.Problems of Sources of deep magmatism and plumes., pp. 59-01.Asia, MongoliaMagmatism
DS1986-0194
1986
Drinkwater, J.L.Drinkwater, J.L., Ford, A.B., Czamanske, G.K.Apatites of the Dufek intrusion; a preliminary studyAntarctic Journal of the United States, Vol. 21, No. 5, pp. 66-69AntarcticaAlkaline rocks, Dufek
DS201812-2804
2018
Driscol, P.Driscol, P.What goes on deep inside Earth's magnetic dynamo?dtm.carnegiescience.edu, 6p. PdfMantlegeodynamics

Abstract: Earth's global magnetic field shields us from the dangers of space, including harmful levels of Solar radiation. This shield is one of the major reasons why life has survived on Earth, and it all starts in the core, where the geomagnetic field is generated by the turbulent motion of liquid iron deep inside the planet. It's the so-called geodynamo. Scientists like DTM's Peter Driscoll devote their career to understanding the nature of such planetary dynamics. In 2016, Driscoll's research suggested that in ancient times Earth may have been significantly different, with prolonged periods of weak field intensity and strange multipolar geometry with many poles in contrast to the modern north-and-south pole orientation. Now, in a recent paper co-authored with DTM's Cian Wilson, Driscoll finds that geologic evidence for such a complex magnetic field will be very difficult to identify. In preparation for his Neighborhood Lecture on November 8, 2018, Driscoll answers some questions about his latest research and why studying the geodynamo is critical to understanding the history of our planet.
DS200412-0957
2004
Driscoll, N.W.Karner, G.D., Taylor, B., Driscoll, N.W., Kohlstedt, D.L.Rheology and deformation of the lithosphere at continental margins.Colombia University Press, 384p. approx $ 50.00 mh230 @colombia.eduMantleBook - large scale deformation
DS200912-0187
2009
Driscoll, P.Driscoll, P., Olson, P.Polarity reversals in geodynamo models with core evolution.Earth and Planetary Science Letters, Vol. 282, 1-4, pp. 24-33.MantleBoundary
DS201212-0793
2012
Driscoll, P.Wu, B., Driscoll, P., Olson, P.A statistical boundary layer model for the mantle "D" region.Journal of Geophysical Research, Vol. 116, B12, B12112MantleBoundary
DS201608-1400
2016
Driscoll, P.Driscoll, P.What did Earth's ancient magnetic field look like?Geophysical Research Letters , June 30, 4p.MantleGeophysics - magnetics

Abstract: New work from Carnegie’s Peter Driscoll suggests Earth’s ancient magnetic field was significantly different than the present day field, originating from several poles rather than the familiar two. It is published in Geophysical Research Letters. Earth generates a strong magnetic field extending from the core out into space that shields the atmosphere and deflects harmful high-energy particles from the Sun and the cosmos. Without it, our planet would be bombarded by cosmic radiation, and life on Earth’s surface might not exist. The motion of liquid iron in Earth’s outer core drives a phenomenon called the geodynamo, which creates Earth’s magnetic field. This motion is driven by the loss of heat from the core and the solidification of the inner core. But the planet’s inner core was not always solid. What effect did the initial solidification of the inner core have on the magnetic field? Figuring out when it happened and how the field responded has created a particularly vexing and elusive problem for those trying to understand our planet’s geologic evolution, a problem that Driscoll set out to resolve. Here’s the issue: Scientists are able to reconstruct the planet’s magnetic record through analysis of ancient rocks that still bear a signature of the magnetic polarity of the era in which they were formed. This record suggests that the field has been active and dipolar—having two poles—through much of our planet’s history. The geological record also doesn’t show much evidence for major changes in the intensity of the ancient magnetic field over the past 4 billion years. A critical exception is in the Neoproterozoic Era, 0.5 to 1 billion years ago, where gaps in the intensity record and anomalous directions exist. Could this exception be explained by a major event like the solidification of the planet’s inner core? In order to address this question, Driscoll modeled the planet’s thermal history going back 4.5 billion years. His models indicate that the inner core should have begun to solidify around 650 million years ago. Using further 3-D dynamo simulations, which model the generation of magnetic field by turbulent fluid motions, Driscoll looked more carefully at the expected changes in the magnetic field over this period. “What I found was a surprising amount of variability,” Driscoll said. “These new models do not support the assumption of a stable dipole field at all times, contrary to what we’d previously believed.” His results showed that around 1 billion years ago, Earth could have transitioned from a modern-looking field, having a “strong” magnetic field with two opposite poles in the north and south of the planet, to having a “weak” magnetic field that fluctuated wildly in terms of intensity and direction and originated from several poles. Then, shortly after the predicted timing of the core solidification event, Driscoll’s dynamo simulations predict that Earth’s magnetic field transitioned back to a “strong,” two-pole one. “These findings could offer an explanation for the bizarre fluctuations in magnetic field direction seen in the geologic record around 600 to 700 million years ago,” Driscoll added. “And there are widespread implications for such dramatic field changes.” Overall, the findings have major implications for Earth’s thermal and magnetic history, particularly when it comes to how magnetic measurements are used to reconstruct continental motions and ancient climates. Driscoll’s modeling and simulations will have to be compared with future data gleaned from high quality magnetized rocks to assess the viability of the new hypothesis.
DS201903-0504
2019
Driscoll, P.Driscoll, P.Geodynamics recharged. Nature Geoscience, Vol. 12, pp. 83-84.MantleGeophysics - magnetics

Abstract: Transition from a weak and erratic geomagnetic field to a more stable one around 560 million years ago, inferred from palaeomagnetic measurements, suggests that the inner core may have solidified around that time, much later than thought.
DS201909-2035
2019
Driscoll, P.E.Driscoll, P.E., Du, Z.Geodynamo conductivity limits.Geophysical Research Letters, Vol. 46, 14, pp. 7982-7989.Mantlegeophysics

Abstract: In a metal, as in Earth's core, the thermal and electrical conductivities are assumed to be correlated. In a planetary dynamo this implies a contradiction: that both electrical conductivity, which makes it easier to induce current and magnetic field, and conductive heat transport, which hinders thermal convection, should increase simultaneously. Here we show that this contradiction implies that the magnetic induction rate peaks at a particular value of electrical and thermal conductivity and derive the low? and high?conductivity limits for thermal dynamo action. A dynamo regime diagram is derived as a function of electrical conductivity and temperature for Earth's core that identifies four distinct dynamo regimes: no dynamo, thermal dynamo, compositional dynamo, and thermocompositional dynamo. Estimates for the temperature?dependent electrical conductivity of the core imply that the geodynamo may have come close to its high?conductivity “no dynamo” limit prior to inner core nucleation, consistent with recent paleomagnetic observations.
DS201312-0228
2013
Dristas, J.A.Dristas, J.A., Martinez, J-C., Massone, H-J., Pimentel, M.M.Mineralogical and geochemical characterization of a rare ultramafic lamprophyre in the Tandilia belt basement, Rio de la Plata, Argentina.Journal of South American Earth Sciences, Vol. 43, pp. 46-61.South America, ArgentinaLamprophyre
DS2003-0352
2003
Drohan, M.Drohan, M.Making a killing: how and why corporations use armed force to do business. Rhodes (Random House Canada Publ., 376p. $ 37.95AfricaHistory
DS200412-0485
2003
Drohan, M.Drohan, M.Making a killing: how and why corporations use armed force to do business. Rhodes ( De Beers, King Leopold, Talisman Energy, UNRandom House Canada , 376p. $ 37.95AfricaHistory
DS201112-0288
2011
Drohan, M.Drohan, M.Big country, small steps.. taking a critical look at the last decade of corporate social responsibility in Canada. Mentions KPCorporate Knights, No. 35, spring pp. 25-28.CanadaNews item - CSR
DS202106-0934
2021
Drollner, M.Drollner, M., Barham, M., Kirkland, C.L., Ware, B.Every zircon deserves a date: selection bias in detrital geochronology.** not specific to diamondsGeological Magazine, Vol. 158, 6, pp. 1135-1142. pdfGlobalgeochronology

Abstract: Detrital zircon geochronology can help address stratigraphic- to lithospheric-scale geological questions. The approach is reliant on statistically robust, representative age distributions that fingerprint source areas. However, there is a range of biases that may influence any detrital age signature. Despite being a fundamental and controllable source of bias, handpicking of zircon grains has received surprisingly little attention. Here, we show statistically significant differences in age distributions between bulk-mounted and handpicked fractions from an unconsolidated heavy mineral sand deposit. Although there is no significant size difference between bulk-mounted and handpicked grains, there are significant differences in their aspect ratio, circularity and colour, which indicate inadvertent preferential visual selection of euhedral and coloured zircon grains. Grain colour comparisons between dated and bulk zircon fractions help quantify bias. Bulk-mounting is the preferred method to avoid human-induced selection bias in detrital zircon geochronology.
DS2002-0405
2002
Dromart, G.Dromart, G., Garcia, J.P., Allemand, Gaumet, RouselleA volume based approach to calculation of ancient carbonate accumulationsJournal of Geology, Vol.110,1,pp. 195-210.GlobalCarbonate - overview deposit rates, Phanerozoic - exogenic systems
DS1984-0242
1984
Dromgoole, E.L.Dromgoole, E.L.Petrology and chemistry of sulfides in xenoliths from Kilbourne Hole, NewMexicoMsc. Thesis, Washington Univ, 199pColorado Plateau, New MexicoBlank
DS1985-0155
1985
Dromgoole, E.L.Dromgoole, E.L., Pasteris, J.D.Interpretation of the Sulfide Assemblages in a Suite of Xenoliths from Kilbourne Hole, New Mexico.Geological Society of America (GSA), Vol. 17, No. 3, P. 157. (abstract.).United States, New Mexico, Colorado PlateauPetrography, Analyses
DS1987-0163
1987
Dromgoole, E.L.Dromgoole, E.L., Pasteris, J.D.Interpretation of the sulfide assemblages in a suite of xenoliths from Kilbourne Hole, New MexicoMantle metasomatism and alkaline magmatism, edited E. Mullen Morris and, No. 215, pp. 25-46New MexicoMineralogy, Analyses
DS201905-1056
2019
Drooff, C.Lavayssiere, A., Drooff, C., Ebinger, C., Gallacher, R., Illsley-Kemp, F., Finnigan, Oliva, S.J., Keir, D.Deep extent and kinematics of faulting in the southern Tanganyika Rift, Africa.Tectonics, Vol. 38, 3, pp. 842-862.Africarifting

Abstract: Unusually deep earthquakes occur beneath rift segments with and without surface expressions of magmatism in the East African Rift system. The Tanganyika rift is part of the Western rift and has no surface evidence of magmatism. The TANG14 array was deployed in the southern Tanganyika rift, where earthquakes of magnitude up to 7.4 have occurred, to probe crust and upper mantle structure and evaluate fault kinematics. Four hundred seventy?four earthquakes detected between June 2014 and September 2015 are located using a new regional velocity model. The precise locations, magnitudes, and source mechanisms of local and teleseismic earthquakes are used to determine seismogenic layer thickness, delineate active faults, evaluate regional extension direction, and evaluate kinematics of border faults. The active faults span more than 350 km with deep normal faults transecting the thick Bangweulu craton, indicating a wide plate boundary zone. The seismogenic layer thickness is 42 km, spanning the entire crust beneath the rift basins and their uplifted flanks. Earthquakes in the upper mantle are also detected. Deep earthquakes with steep nodal planes occur along subsurface projections of Tanganyika and Rukwa border faults, indicating that large offset (?5 km) faults penetrate to the base of the crust, and are the current locus of strain. The focal mechanisms, continuous depth distribution, and correlation with mapped structures indicate that steep, deep border faults maintain a half?graben morphology over at least 12 Myr of basin evolution. Fault scaling based on our results suggests that M > 7 earthquakes along Tanganyika border faults are possible.
DS1950-0021
1950
Droogmans, H.Droogmans, H., Robert, M., Maury, G.Atlas du KatangaBruxelles: Com. Spec. Du Katanga., Democratic Republic of Congo, Central AfricaGeology, Mineral Resources
DS201012-0133
2010
Droop, G.Cuthbert, S., Qas-Cohen, A., Ballentine, C., Burgess, R., Droop, G.Norwegian garnet websterites: analogues for mantle metasomatism?Goldschmidt 2010 abstracts, abstractEurope, NorwayMetasomatism
DS201112-0837
2011
Droop, G.Quas-Cohen, A., Cuthbert, S., Droop, G., Ballentine, C.J., Burgess, R.Diamond facies fluid flow during subduction: evidence and consequence.Goldschmidt Conference 2011, abstract p.1683.Europe, NorwayWestern Gneiss region
DS1995-1831
1995
Droop, G.T.R.Stevens, G., Clemens, J.D., Droop, G.T.R.Hydrous cordierite in the high grade crust: implications for magmagenerationEconomic Geology Research Unit, Witwatersrand, No. 289, 12pGlobalPetrology - experimental, Magma generation
DS1996-1371
1996
Droop, G.T.R.Stevens, G., Clemns, J.D., Droop, G.T.R.Magma production during granulite facies anatexis: dat a from primitivemeta sedimentary protolithsEconomic Geology Research Unit, Witwatersrand, No. 298, 40pGlobalGranites, Petrology -experimental
DS1996-1372
1996
Droop, G.T.R.Stevens, G., Gibson, R.L., Droop, G.T.R.Polyphase granulite metamorphism in the Vredefort Dome: a window into the deep Kaapvaal craton at 2.06 GaEconomic Geology Research Unit, No. 297, 27pSouth AfricaCraton -Kaapvaal, Greenstone remnants
DS1997-1104
1997
Droop, G.T.R.Stevens, G., Gibson, R.L., Droop, G.T.R.Mid-crustal granulite facies metamorphism in the Central Kaapvaal Craton:Bushveld Complex connectionPrecambrian Research, Vol. 82, No. 1-2, March 1, pp. 113-32South AfricaCraton - Kaapvall, Bushveld Complex, layered intrusion
DS1997-1105
1997
Droop, G.T.R.Stevens, G., Gibson, R.L., Droop, G.T.R.Mid crustal granulite facies metamorphism in the Central Kaapvaal craton:Bushveld Complex connectionPrecambrian Research, Vol. 82, No. 1-2, March pp. 113-132South Africametamorphism, Bushveld Complex
DS1998-0259
1998
Droop, G.T.R.Clemens, J.D., Droop, G.T.R.Fluids, P T paths and the fates of anatectic melts in the Earth's crustLithos, Vol. 44, No. 1-2, Oct., pp. 21-36.MantleMelt, Magmas
DS1994-0458
1994
Drory, M.D.Drory, M.D., Hutchinson, J.W.Diamond coating of titanium alloysScience, Vol. 263, March 25, pp. 1753-1755.GlobalDiamond synthesis -CVD.
DS200912-0188
2008
Droschel, R.Droschel, R.,Evers, J., Ottomeyer, H.The Wittelsbach blue.... 35.56 carat diamond.Gems & Gemology, Vol. 44, 4, pp. 348-363.IndiaDiamonds notable - history
DS1984-0243
1984
Drosdov, V.P.Drosdov, V.P., Turinge, A.P.Gems of the Ussr. Regularity of Distribution. New DiscoveriesIn: Proceedings of the 27th. International Geological Congress held Moscow, August, Vol. 15, pp. 331-341RussiaBrief Mention
DS201112-0390
2011
Drost, K.Grosch, E.G., Kosler, J., McLoughlin, N., Drost, K., Slama, J., Pedersen, R.B.Paleoarchean detrital zircon ages from the earliest tectonic basin in the Barberton greenstone belt, Kaapvaal craton, South Africa.Precambrian Research, Vol. 191, 1-2, pp. 85-99.Africa, South AfricaGeochronology
DS201312-0036
2013
Drouet, S.Assumpcao, M., Bianchi, M., Julia, J., Dias, F.L., Nascimento, R., Drouet, S., Pavao, C.G., Albuquerque, D.F., Lopes, A.E.V.Crustal thickness map of Brazil: dat a compilation and main features.Journal of South American Earth Sciences, Vol. 609, pp. 82-96.South America, BrazilMOHO map
DS1994-0658
1994
Drouillard, P.H.Green, G.N., Drouillard, P.H.The digital geologic map of Wyoming in Arc/INFO formatUnited States Geological Survey (USGS) Open file, No. 94-0425, 10p. $ 1.75WyomingMap, GIS -digitized
DS200512-0987
2004
DrozdovaSimakov, S.K., Kalmykov, A.E., Sorokin, L.M., Novikov, Drozdova, Yagovkina, GrebenshchikovaChaoite formation from carbon bearing fluid at low PT parameters.Doklady Earth Sciences, Vol. 399A, 9, Nov-Dec. pp. 1289-1290.Mineralogy - chaoite
DS200812-1069
2008
Drozdova, I.A.Simakov, S.K., Dubinchuk, V.T., Novikov, M.P., Drozdova, I.A.Formation of diamond and diamond type phases from the carbon bearing fluid at PT parameters correspondoing to processes in the Earth's crust.Doklady Earth Sciences, Vol. 421, 1, pp. 835-837.MantleDiamond genesis
DS202004-0504
2020
Drozdova, T.E.Chernykh, S.V., Chernykh, A.V., Tarelkin, S., Didenko, S. ,Kondakov, M.N., Shcherbachev, K.D., Trifonova, E.V., Drozdova, T.E., Troschiev, S.Y., Prikhodko, D.D., Glybin, Y.N., Chubenko, A.P., Britvich, G.I., Kiselev, D.A., Polushin, N.I., Rabinovich, O.IHPHT single crystal diamond type IIa characterization for particle detectors.Physicsa Status Solidi , doi:10.1002/pssa.201900888GlobalHPHT

Abstract: Various samples of multisectoral high?pressure high?temperature (HPHT) single?crystal diamond plate (IIa type) (4?×?4?×?0.53?mm) are tested for particle detection applications. The samples are investigated by X?ray diffractometry, photoluminescence spectroscopy, Raman spectroscopy, Fourier?transform infrared, and visible/ultraviolet (UV) absorption spectroscopy. High crystalline perfection and low impurity concentration (in the {100} growth sector) are observed. To investigate detector parameters, circular 1.0 and 1.5?mm diameter Pt Schottky barrier contacts are created on {111} and {100} growth sectors. On the backside, a Pt contact (3.5?×?3.5?mm) is produced. The {100} growth sector is proved to be a high?quality detector: the full width at half maximum energy resolution is 0.94% for the 5.489?MeV 226Ra ??line at an operational bias of +500?V. Therefore, it is concluded that the HPHT material {100} growth sector is used for radiation detector production, whose quality is not worse than the chemical vapor deposition method or specially selected natural diamond detectors.
DS202005-0725
2020
Drsydale, Rn.Castillo-Oliver, M., Giuliani, A., Griffin, W.L., Drsydale, Rn.New constraints on the source, composition, and post-emplacement modification of kimberlites from in situ C-O-Sr-isotope analyses of carbonates from the Benfontein sills ( South Africa).Contributions to Mineralogy and Petrology, in press available, 21p. PdfAfrica, South Africadeposit - Benfontein

Abstract: Primary carbonates in kimberlites are the main CO2 carriers in kimberlites and thus can be used to constrain the original carbon and oxygen-isotope composition of kimberlite melts and their deep mantle sources. However, the contribution of syn- and post-emplacement processes to the modification of the C-O-isotope composition of kimberlites is yet to be fully constrained. This study aims to shed new light on this topic through a detailed textural, compositional (major and trace elements), and in situ C-O-Sr isotopic characterisation of carbonates in the Benfontein kimberlite sills (Kimberley, South Africa). Our multi-technique approach not only reveals the petrographic and geochemical complexity of carbonates in kimberlites in unprecedented detail, but also allows identification of the processes that led to their formation, including: (1) magmatic crystallisation of Sr-rich calcite laths and groundmass; (2) crystallisation of late groundmass calcite from hydrothermal fluids; and (3) variable degrees of crustal contamination in carbonate-rich diapirs and secondary veins. These diapirs most likely resulted from a residual C-O-H fluid or carbonate melt with contributions from methane-rich fluids from the Dwyka shale wall rock, leading to higher 87Sr/86Sr and ?18O, but lower ?13C values than in pristine magmatic calcite. Before coalescing into the diapiric segregations, these fluids/melts also variably entrained early formed calcite laths and groundmass phases. Comparison between in situ and bulk-carbonate analyses confirms that O isotopic analyses of bulk carbonates from kimberlite rocks are not representative of the original isotopic signature of the kimberlite magma, whereas bulk C-isotope compositions are similar to those of the pristine magmatic carbonates. Calcite laths and most groundmass grains at Benfontein preserve isotopic values (?18O?=?6-8‰ and ?13C?=???4 to ??6‰), similar to those of unaltered carbonatites worldwide, which, therefore, probably correspond to those of their parental melts. This narrow range suggests kimberlite derivation from a mantle source with little contribution from recycled crustal material unless the recycled material had isotopic composition indistinguishable from typical mantle values.
DS1987-0411
1987
Drubetskoy, Ye.R.Levskiy, L.K., Drubetskoy, Ye.R.Isotopic stratification of the mantle: a summary.(Russian)In: Geochronology and geochemistry of isotopes: a collection of scientific, pp. 110-127RussiaBlank
DS1989-1561
1989
Drubetzkoy, E.R.Vistelius, A.B., Drubetzkoy, E.R., Faas, A.V.Statistical estimation of mineral age by K-Ar methodMathematical Geology, Vol. 21, No. 8, November pp. 905-920GlobalGeostatistics, Geochronology
DS1995-0446
1995
Drucker, I.G.Drucker, I.G.Shear velocity structure of the crust and upper mantle in the KolaPeninsula.Eos, Vol. 76, No. 46, Nov. 7. p.F416-17. Abstract.Russia, Kola PeninsulaMantle, Geophysics -seismic
DS1986-0195
1986
Drucker, M.D.Drucker, M.D.The geology, geochemistry and origin of fenites from thealkaline complexes of northeastern Paraguay, South AmericaGeological Association of Canada (GAC) Annual Meeting, Vol. 11, p. 64, (abstract.)GlobalAlkaline rocks
DS200612-0354
2006
Drucker, R.B.Drucker, R.B.Social, political, economic and gemological impacts on pricing trends. Gemworld International.GIA Gemological Research Conference abstract volume, Held August 26-27, p. 36. 1/2p.GlobalEconomics - pricing
DS1985-0413
1985
Druecker, M.D.Mariano, A.N., Druecker, M.D.Alkaline Igneous Rocks and Carbonatites of ParaguayGeological Society of America (GSA), Vol. 17, No. 3, P. 166. (abstract.).South America, ParaguayGeophysics, Lineaments
DS1994-0459
1994
Druecker, M.D.Druecker, M.D.Mineralogy, mass transfer reactions and intensive parameters associated with fenitization at the Chiriguelo carbonatite complex, Paraguay.Geological Association of Canada (GAC) Abstract Volume, Vol. 19, p.GlobalCarbonatite
DS1993-0551
1993
Drugova, G.M.Glebovitsky, V.A., Drugova, G.M.Tectonothermal evolution of the western Aldan shield, SiberiaPrecambrian Research, Vol. 62, pp. 493-505GlobalTectonics, Geotectonics
DS201112-0289
2011
Druiventak, A.Druiventak, A., Trepmann, C.A., Renner, J., Hanke, K.Low temperature plasticity of olivine during high stress deformation of peridotite at lithospheric conditions - an experimental study.Earth and Planetary Science Letters, Vol. 311, 3-4, pp. 199-211.MantlePeridotite
DS201201-0841
2011
Druiventak, A.Druiventak, A., Matsiak, A., Renner, J., Trepmann, C.A.Kick and cook experiments on peridotite: simulating coseismic deformation and post-seismic creep.Terra Nova, In press available,MantleGeophysics - seismics
DS201212-0171
2012
Druiventak, A.Druiventak, A., Matsyiak, A., Renner, J., Trepmann, C.Kick and cook experiments on peridotite: simulating coseismic deformation post-seismic creep.Terra Nova, Vol. 24, 1, pp. 62-69.MantleGeophysics - seismics
DS1950-0210
1955
Drukker and zon, D.Drukker and zon, D.Diamant in Kunst En IndustrieAmsterdam: Privately Publishing, GlobalKimberlite
DS1998-0521
1998
Drummond, B.Goncharov, A., Drummond, B., Tripolsky, A., Wyborn, L.Average composition of the crust in the Australian, Fennoscandian and Ukrainian shields from refraction..Agso Research Newsletter, No. 28, May pp. 20-23Australia, Ukraine, Norway, Finland, SwedenGeophysics - seismics, Petrology
DS2003-0353
2003
Drummond, B.Drummond, B.Brief description of IGCP project No. 474. Images of the Earth's crust - inner spaceThe Australian Geologist, No. 128, Sept. 30, pp. 32-3.GlobalGeophysics - seismics
DS200412-0486
2003
Drummond, B.Drummond, B.Brief description of IGCP project no. 474. Images of the Earth's crust - inner space, the continents and their margins.The Australian Geologist, No. 128, Sept. 30, pp. 32-3.TechnologyGeophysics - seismics
DS1989-0368
1989
Drummond, B.J.Drummond, B.J., Muirhead, K.J., Wright, C., Wellman, P.A teleseismic travel time residual map of the Australian continentBmr Journal Of Australian Geol. And Geophysics, Vol. 11, pp. 101-105AustraliaGeophysics, Seismics-continent
DS1991-0402
1991
Drummond, B.J.Drummond, B.J., Sexton, M.J., Barton, T.J., Shaw, R.D.The nature of faulting along the margins of the Fitzroy trough, CanningBasin, and implications for the tectonic development of the troughAustralian Society of Exploration Geophysicists and Geological Society of Australia, 8th. Exploration Conference in the Bulletin., Vol. 22, No. 1, March pp. 111-116AustraliaStructure, Geophysics
DS1993-0377
1993
Drummond, B.J.Drummond, B.J., Goleby, B.R., Swager, C.P., Williams, P.R.Constraints on Archean crustal composition and structure provided by deep seismic sounding in the Yilgarn blockOre Geology Reviews, Vol. 8, pp. 117-124AustraliaGeophysics, Kalgoorlie Terrane, Callion Terrane
DS1994-0634
1994
Drummond, B.J.Goleby, B.R., Drummond, B.J., Korsch, R.J., et al.Review of recent results from continental deep seismic profiling inAustraliaTectonophysics, Vol. 232, 1-4, pp. 1-12AustraliaGeophysics -seismics, Profiles
DS1995-0447
1995
Drummond, B.J.Drummond, B.J., Goncharov, A.G., Collins, C.D.N.Upper crustal heterogeneities in Australian Precambrian provinces interpreted from deep seismic profiles (Kola)Agso Journal Of Australia Geol.and Geophysics, Vol. 15, No. 4, ppAustraliaGeophysics -seismics, Kola Superdeep Bore Hole
DS1998-0792
1998
Drummond, B.J.Korsch, R.J., Goleby, B.R., Drummond, B.J.Crustal architecture of central Australia based on deep seismic reflectionprofiling.Tectonophysics, Vol. 288, No. 1-4, Mar. pp. 57-70.Australia, Central AustraliaTectonics, Geophysics - seismic
DS2000-0227
2000
Drummond, B.J.Dentith, M.C., Dent, V.F., Drummond, B.J.Deep crustal structure in the southwestern Yilgarn Craton, western Australia.Tectonophysics, Vol. 235, No.3-4, Oct. 30, pp. 227-56.Australia, westernTectonics, Craton - Yilgarn
DS2000-0245
2000
Drummond, B.J.Drummond, B.J., Goleby, B.R., Sawger, C.P.Crustal signature of Late Archean tectonic episodes in the Yilgarn Craton:evidence from deep seismic soundingTectonophysics, Vol. 329, No. 1-4, Dec. 31, pp. 193-222.AustraliaGeophysics - seismics, Tectonics - craton
DS200412-0346
2004
Drummond, B.J.Collins, C.D.N., Drummond, B.J., Nicoll, M.G.Crustal thickness patterns in the Australian continent.Hillis, R.R., Muller, R.D. Evolution and dynamics of the Australian Plate, Geological Society America Memoir, No. 372, pp. 107-120.AustraliaTectonics
DS200412-1312
2004
Drummond, B.J.Milligan, P.R., Petkovic, P., Drummond, B.J.Potential field datasets for the Australian region: their significance in mapping basement architecture.Hillis, R.R., Muller, R.D. Evolution and dynamics of the Australian Plate, Geological Society America Memoir, No. 372, pp. 129-140.AustraliaGeophysics - seismics
DS200612-1465
2005
Drummond, B.J.Van der Velden, A.J., Cook, F.A., Drummond, B.J., Goleby, B.R.Reflections of the Neoarchean: a global perspective.Benn, K., Mareschal, J-C., Condie, K.C. Archean Geodynamics and Environments, AGU Geophysical Monograph, No. 164, pp. 255-266.MantleGeophysics - seismsics
DS1995-0448
1995
Drummond, I.Drummond, I., Mursden, T.K.Regulating sustainable developmentGlobal Environmental Change, Vol. 5, No. 1, March pp. 51-64United StatesEconomics, Environment
DS200712-0900
2007
Drummond, J.Rodriques da Silva Enriquez, M.A., Drummond, J.Social environmental certification: sustainable development and competitiveness in the mineral industry of the Brazilian Amazon.Natural Resources Forum, Vol. 31, pp. 71-86.South America, BrazilEnvironmental - metals
DS1990-0396
1990
Drummond, M.S.Defant, M.J., Drummond, M.S.Derivation of some modern arc magmas by melting of young subductedlithosphereNature, Vol. 347, October 18, pp. 662-665GlobalMantle Subduction
DS1990-0429
1990
Drummond, M.S.Drummond, M.S., Defant, M.J.A model for trondhjemite tonalite dacit genesis and crustal growth via slabmelting: archean to modern.Journal of Geophysical Research, Vol. 95, No. B 13, Dec. 10, pp. 21503-21.MantleTectonics, Melting, subduction
DS1995-0939
1995
Drummond, M.S.Kepezhinskas, P.K., Defant, M.J., Drummond, M.S.NA metasomatism in the Island Arc mantle by slab melt peridotite interaction -evidence north Kamchatka arcJournal of Petrology, Vol. 36, No. 6, Dec. pp. 1505-1527.RussiaSubduction, Sodium, Metasomatism
DS1996-0727
1996
Drummond, M.S.Kepezhinkas, P., Defant, M.J., Drummond, M.S.Progressive enrichment of island arc mantle by melt peridotite interaction inferred - Kamchatka xenoliths.Geochimica et Cosmochimica Acta, Vol. 60, No. 7, April, pp. 1217-1229RussiaXenoliths, Geochemistry - peridotite, Kamchatka Arc, Kamchatka
DS200512-1181
2005
Drumond, G.Williams, M.L., Jercinovic, M.J., Mahan, K., Drumond, G., Flowers, R.M., Davis, W.J.Regional high T metamorphic events in Proterozoic crust of Laurentia: implications of magmatic underplating for regional tectonics crustal evolution.GAC Annual Meeting Halifax May 15-19, Abstract 1p.Canada, Nunavut, Saskatchewan, AlbertaTectonics, Churchill Province
DS2000-0990
2000
Druppel, K.Von Seckendorff, V., Druppel, K., Okrusch, M.Oxide sulphide relationships in sodalite bearing metasomatites of the Epembe Swartbooisdrif alkaline...Min. Deposita, Vol. 35, pp. 430-50.NamibiaCarbonatite
DS2002-0406
2002
Druppel, K.Druppel, K., Hoefs, J., Litmann, S., Okrusch, M.Carbonatite related fenitisation processes at the southern margin of the Kunene intrusive complex, NW Namibia.18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.250.Namibiacarbonatite - mineralogy
DS200512-0248
2005
Druppel, K.Druppel, K., Hoefs, J., Okrusch, M.Fenitizing processes induced by ferrocarbonatite magmatism at Swartbooisdrif, northwest Namibia.Journal of Petrology, Vol. 46, no. 2, pp. 377-406.Africa, NamibiaCarbonatite
DS200612-0355
2006
Druppel, K.Druppel, K., Wagner, T., Boyce, A.J.Evolution of sulfide mineralization in ferrocarbonatite, Swartbooisdiff, northwestern Namibia: constraints from mineral composition and sulfur isotopeCanadian Mineralogist, Vol. 44, 4, August pp. 877-894.Africa, NamibiaCarbonatite
DS200412-0532
2004
Druru, M.R.Falus, G., Druru, M.R., Van Roermund, H.L.M., Szabo, C.Magmatism related localized deformation in the mantle: a case study.Contributions to Mineralogy and Petrology, Vol. 146, no. 4, pp. 493-505.MantleMagmatism
DS200912-0721
2009
DrurySpengler, D., Brueckner, H.K., Herman, L.M., Van Roermund, Drury, MasonLong lived, cold burial of Baltica to 200 km depth.Earth and Planetary Science Letters, Vol. 281, 1-2, April 30, pp. 27-35.Europe, Baltic ShieldSubduction
DS1987-0164
1987
Drury, M.Drury, M., Taylor, A.Some new measurements of heat flow in the Superior Province of the Canadian ShieldCanadian Journal of Earth Sciences, Vol. 24, No. 7, July pp. 1486-1489CanadaHeat Flow, Geothermometry
DS2002-0366
2002
Drury, M.De Meer, S., Drury, M., De Bresser, H., Pennock, G.Deformation mechanisms, rheology and tectonics : current status and future perspectives.Geological Society of London (U.K.), 424p.$ 167.00 http://bookshop.geolsoc.org.ukMantleBook - tectonics, deformation, lithosphere
DS2003-0324
2003
Drury, M.De Meer, S., Drury, M., De Bresser, H., Pennock, G.Deformation mechanisms, rheology and tectonics: current status and futureGeological Society of London Special Paper, No. 200, 424p. $ 240. www.geosoc.orgMantleCrustal layers, tectonics, structure, Book
DS201705-0885
2017
Drury, M.van den Heuvel, Q., Matveev, S., Drury, M., Gress, M., Chinn, I., Davies, G.Genesis of diamond inclusions: an integrated cathodluminescence ( CL) and electron backscatter diffraction (EBSD) study on eclogitic and peridotitic inclusions and their diamond host.European Geosciences Union General Assembly 2017, Vienna April 23-28, 1p. 6564 AbstractAfrica, BotswanaDeposit - Jwaneng, Letlhakane
DS1985-0156
1985
Drury, M.J.Drury, M.J.The Iceland Research Drilling Project Crustal section: physical properties of some basalts Reydarfjordur.Canadian Journal of Earth Sciences, Vol. 22, pp. 1588-93.GlobalBasalts, Dikes
DS1987-0414
1987
Drury, M.J.Lewis, T.J., Drury, M.J.Heat flow and heat generation in the Churchill Province of the CanadianShield, and their paleotectonic significance-discussionTectonophysics, Vol.132, No.4, Jan. 15, pp. 343-350CanadaShield, Heat Flow
DS1988-0178
1988
Drury, M.J.Drury, M.J.Tectonothermics of the North American Great Plains basementTectonophysics, Vol. 148, No. 3-4, May 1, pp. 299-308MidcontinentBlank
DS1989-0369
1989
Drury, M.J.Drury, M.J.The heat flow-heat generation relationship implications for the nature of continental crustTectonophysics, Vol. 164, No. 2-4, August 1, pp. 93-106CanadaMantle, Crust -heat flow
DS1991-0795
1991
Drury, M.J.Jessop, A.M., Ghomshei, M.M., Drury, M.J.Geothermal energy in CanadaGeothermics, Vol. 20, No. 5-6, pp. 369-385CanadaGeothermal energy, Overview
DS1991-0796
1991
Drury, M.J.Jessop, A.M., Lewis, T.J., Drury, M.J.Terrestrial heat flow in CanadaTerrestrial Heat Flow and the Lithosphere Structure, editors Cermak, V. and, Springer Verlag, pp. 457-474CanadaHeat flow, Geophysics
DS1992-0395
1992
Drury, M.J.Drury, M.J.Heat flow in the Canadian shield and its relation to other geophysicalparametersTerrestrial Heat Flow and the Lithosphere Structure, editors Cermak, V. and, Springer Verlag, pp. 317-337CanadaHeat flow, Geophysics
DS1989-0591
1989
Drury, M.J. editors.Harper, C., Drury, M.J. editors.Kimberlites in the Western Canadian Sedimentary BasinScientific Drilling, sedimentary basins, proceedings of a workshop Can., 1989, pp. 25-26Western Canada, United StatesNews item, Drilling/continental Program
DS1988-0179
1988
Drury, M.R.Drury, M.R., Van Roermund, H.L.M.Metasomatic origin for iron titanium rich multiphase inclusions in olivine from kimberlite xenolithsGeology, Vol. 16, No. 11, pp. 1035-1088South AfricaMineralogy, Kimberlite xenoliths
DS1989-0370
1989
Drury, M.R.Drury, M.R.The Sudbury structure: a CCDP workshop reportGeoscience Canada, Vol. 16, No. 1, March pp. 29-30OntarioSudbury structure, Tectonics
DS1989-0371
1989
Drury, M.R.Drury, M.R., Van Roermund, H.L.M.Fluid assisted recrystallization in upper mantle peridotite xenoliths fromkimberlitesJournal of Petrology, Vol. 30, No. 1, pp. 133-152South AfricaThaba Putsoa, Xenoliths
DS1995-2001
1995
Drury, M.R.Vissers, R.L.M., Drury, M.R., Van der Wal, D.Mantle shear zones and their effect on lithosphere strength during continental breakup.Tectonophysics, Vol. 249, No. 3/4, Sept. 30, pp. 155-172.MantleTectonics, Geodynamics
DS1996-0389
1996
Drury, M.R.Drury, M.R., Fitzgerald, J.D.Grain boundary melt films in an experimentally deformed olivine orthopyroxene rock: implications for melt....Geophysical Research. Letters, Vol. 23, No. 7, Apr. 1, pp. 701-704.MantleOlivine melt distribution
DS1999-0764
1999
Drury, M.R.Van Roermund, H.L.M., Drury, M.R.Ultra high pressure ( P>6GPa) garnet peridotites in western Norway:exhumation of mantle rocks from 185kM.Terra Nova, Vol. 10, pp. 295-301.NorwayGarnet - majoritic, Mineral chemistry
DS2001-1188
2001
Drury, M.R.Van Roermund, H.L., Drury, M.R., Barnhoorn, De RondeRelict majoritic garnet microstructures from ultra deep peridotites in western Norway.Journal of Petrology, Vol. 42, No. 1, Jan. pp. 117-58.NorwayPeridotites, Petrology
DS2002-0367
2002
Drury, M.R.De Meer, S., Drury, M.R., De Bresser, J.H.P., Pennock, G.M.Current issues and new developments in deformation mechanisms, rheology and tectonics.Geological Society of London Special Publication, No.200, pp. 1-28.BlankReview
DS2002-1651
2002
Drury, M.R.Van Roermund, H.L.M., Carswell, D.A., Drury, M.R., Heijboer, T.C.Microdiamonds in a megacrystic garnet websterite pod from Bardane on the island ofGeology, Vol. 30, 11, Nov. pp. 959-62.NorwaySubduction - deep continental, diamond genesis
DS201012-0038
2010
Drury, M.R.Barnhoorn, A., Drury, M.R., Van Roermund, H.L.M.Evidence for low viscosity garnet rich layers in the upper mantle.Earth and Planetary Science Letters, Vol. 289, pp. 54-67.MantleRheology, peridotite, UHP
DS201012-0848
2010
Drury, M.R.Wiggers de Vries, D.F., Drury, M.R., De Winter, D.A.M., Bulanova, G.P., Pearson, D.G., Davies, G.R.Three dimensional cathodluminescence imaging and electron backscatter diffraction: tools for studying the genetic nature of diamond inclusions.Contributions to Mineralogy and Petrology, in press available, 15p.TechnologyDiamond inclusions
DS201112-0061
2011
Drury, M.R.Barnhoorn, A., Van der Wal, W., Drury, M.R.Upper mantle viscosity and lithospheric thickness under Iceland.Journal of Geodynamics, Vol. 52, 3-4, pp. 260-270.Europe, IcelandGeophysics - seismics
DS201112-0231
2011
Drury, M.R.Wiggers de Vries, D.F., Drury, M.R., de Winter, D.A.M., Bulanova, G.P., Pearson, D.G., Davies, G.R.Three dimensional cathodluminescence imaging and electron backscatter diffraction: tools for studying the genetic nature of diamond inclusions.Contributions to Mineralogy and Petrology, Vol. 161, 4, pp. 565-579.RussiaDeposit - Udachnaya
DS201804-0741
2018
Drury, M.R.Spengler, D., van Roermund, H.L.M., Drury, M.R.Deep komatiite signature in cratonic mantle pyroxenite… websterite/Rae cratonJournal of Metamorphic Geology, in press availableEurope, Greenland, Norwaymineral chemistry

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

Abstract: We present new and compiled whole?rock modal mineral, major and trace element data from extremely melt depleted but pyroxenite and garnet(?ite)?bearing Palaeoarchean East Greenland cratonic mantle, exposed as three isolated, tectonically strained orogenic peridotite bodies (Ugelvik, Raudhaugene and Midsundvatnet) in western Norway. The studied lithologies comprise besides spinel? and/or garnet?bearing peridotite (dunite, harzburgite, lherzolite) garnet?clinopyroxenite and partially olivine?bearing garnet?orthopyroxenite and ?websterite. Chemical and modal data and spatial relationships between different rock types suggest deformation to have triggered mechanical mixing of garnet?free dunite with garnet?bearing enclosures that formed garnet?peridotite. Inclusions of olivine in porphyroclastic minerals of pyroxenite show a primary origin of olivine in olivine?bearing variants. Major element oxide abundances and ratios of websterite differ to those in rocks expected to form by reaction of peridotite with basaltic melts or silica?rich fluids, but resemble those of Archean Al?enriched komatiite (AEK) flows from Barberton and Commondale greenstone belts, South Africa. Websterite GdN/YbN, 0.49-0.65 (olivine?free) and 0.73-0.85 (olivine?bearing), overlaps that of two subgroups of AEK, GdN/YbN 0.25-0.55 and 0.77-0.90, with each of them being nearly indistinguishable from one another in not only rare earth element fractionation but also concentration. Websterite MgO content is high, 22.7-29.0 wt%, and Zr/Y is very low, 0.1-1.0. The other, non?websteritic pyroxenites overlap—when mechanically mixed together with garnetite—in chemistry with that of AEK. It follows an origin of websterite and likely all pyroxenite that involves melting of a garnet?bearing depleted mantle source. Pyroxene exsolution lamellae in the inferred solidus garnet in all lithological varieties require the pyroxenites to have crystallized in the majorite garnet stability field, at 3-4 GPa (90-120 km depth) at minimum 1,600°C. Consequently, we interpret the websterites to represent the first recognized deep plutonic crystallization products that formed from komatiite melts. The other pyroxenitic rocks are likely fragments of such crystallization products. An implication is that a mantle plume environment contributed to the formation of (one of) the worldwide oldest lithospheric mantle underneath the eastern Rae craton.
DS201810-2308
2018
Drury, M.R.Davies, G.R., van den Heuvel, Q., Matveev, S., Drury, M.R., Chinn, I.L., Gress, M.U.A combined catholuminescence and electron backscatter diffraction examination of the growth relationships between Jwaneng diamonds and their eclogitic inclusions.Mineralogy and Petrology, doi.org/10.1007/s00710-018-0634-3 12p.Africa, Botswanadeposit - Jwaneng

Abstract: To fully understand the implications of the compositional information recorded by inclusions in diamond it is vital to know if their growth was syn- or protogenetic and the extent to which they have equilibrated with diamond forming agents. The current paradigm is that the majority of inclusions in diamond are syngenetic but recently this assumption has been questioned. This study presents an integrated cathodoluminescence (CL) and electron backscatter diffraction (EBSD) study of 8 diamonds containing eclogitic inclusions: 19 pyrope-almandine garnets, 12 omphacitic clinopyroxenes, 4 sulphides, 1 coesite and 1 rutile from the Jwaneng diamond mine, Botswana. Diamond plates were sequentially polished to expose inclusions at different levels and CL imaging and EBSD were performed to constrain the relationship between diamond and inclusion growth. Despite complex growth and resorption, individual diamonds are single crystals with a homogeneous crystallographic orientation. All individual inclusions have homogeneous crystallographic orientation and no resolvable compositional zonation. The combined CL and EBSD data suggest that epitaxial inclusion-diamond growth is rare (none of 24 inclusions) and that the imposition of cubo-octahedral faces on inclusions does not necessarily result in epitaxy. Individual diamonds contain inclusions that record evidence of both syngentic and protogenetic relationships with the host diamond and in one case an inclusion appears syngenetic to the diamond core but protogenetic to the growth zone that surrounds 70% of the inclusion. These findings emphasise that inclusions in diamonds have multiple modes of origin and that in order to validate the significance of geochronological studies, further work is needed to establish that there is rapid chemical equilibration of protogenetic inclusions with diamond forming agents at mantle temperatures.
DS1994-0004
1994
Drury, R.Abbott, D., Drury, R., Smith, W.H.F.Flat to steep transition in subduction styleGeology, Vol. 22, No. 10, October pp. 937-940MantleSubduction
DS1994-0005
1994
Drury, R.Abbott, D., Drury, R., Smith, W.H.F.Flat to steep transition in subduction styleGeology, Vol. 22, No. 10, October pp. 937-940.MantleTectonics, Subduction
DS1997-0003
1997
Drury, R.Abbott, D.H., Drury, R., Mooney, W.D.Continents as lithological icebergs: the importance of buoyant lithospheric roots.Earth and Planetary Science Letters, Vol. 149, No. 1-4, pp. 15-27.MantleTectonics, Subduction, mantle, Lithospheric roots, Continental Crust
DS1997-0004
1997
Drury, R.Abbott, D.H., Drury, R., Mooney, W.D.Continents as lithological icebergs: the importance of bouyant lithosphericroots.Earth and Planetary Science Letters, Vol. 149, pp. 15-27.Russia, Europe, UralsSubduction, plumes, Oceanic crust
DS1998-0364
1998
Drury, S.Drury, S.Images of the earth: a guide to remote sensingOxford University of Press, GlobalBook - ad, Remote sensing
DS1984-0244
1984
Drury, S.A.Drury, S.A., Harris, N.B.W., Holt, R.W., Reeves-Smith, G.J.Precambrian Tectonics and Crustal Evolution in South IndiaJournal of GEOLOGY, Vol. 92, PP. 3-20.IndiaGeotectonics
DS1993-0378
1993
Drury, S.A.Drury, S.A.Image interpretation in geologyChapman and Hall, 300pBookRemote sensing, Photogeology
DS200412-2166
2004
Druschke, P.A.Yan, Q., Hanson, A.D., Wang, Z., Druschke, P.A., Yan, Z., Wan, T.Neoproterozoic subduction and rifting on the northern margin of the Yangtze Platform: Redonia reconstruction.International Geology Review, Vol.46, 9, Sept. pp. 817-832.ChinaSubduction
DS201911-2534
2019
Druzhbin, D.Ishi, T., Huang, R., Myhill, R., Fei, H., Koemets, I., Liu, Z., Maeda, F., Yuan, L., Wang, L., Druzhbin, D., Yamamoto, T., Bhat, S., Farla, R., Kawazoe, T., Tsujino, N., Kulik, E., Higo, Y., Tange, H., Katsura, T.Sharp 660 km discontinuity controlled by extremely narrow binary post-spinel transition.Nature Geosciences, Vol. 12, pp. 869-872.Mantlediscontinuity

Abstract: The Earth’s mantle is characterized by a sharp seismic discontinuity at a depth of 660?km that can provide insights into deep mantle processes. The discontinuity occurs over only 2?km—or a pressure difference of 0.1?GPa—and is thought to result from the post-spinel transition, that is, the decomposition of the mineral ringwoodite to bridgmanite plus ferropericlase. Existing high-pressure, high-temperature experiments have lacked the pressure control required to test whether such sharpness is the result of isochemical phase relations or chemically distinct upper and lower mantle domains. Here, we obtain the isothermal pressure interval of the Mg-Fe binary post-spinel transition by applying advanced multi-anvil techniques with in situ X-ray diffraction with the help of Mg-Fe partition experiments. It is demonstrated that the interval at mantle compositions and temperatures is only 0.01?GPa, corresponding to 250?m. This interval is indistinguishable from zero at seismic frequencies. These results can explain the discontinuity sharpness and provide new support for whole-mantle convection in a chemically homogeneous mantle. The present work suggests that distribution of adiabatic vertical flows between the upper and lower mantles can be mapped on the basis of discontinuity sharpness.
DS201802-0245
2017
Druzhinin, S.V.Kiselev, G.P., Yakovlev, E.Yu., Druzhinin, S.V., Galkin, A.S.Distribution of radioactive isotopes in rock and ore of Arkhanelskava pipe from the Arkhanelsk diamond province.Geology of Ore Deposits, Vol. 59, pp. 391-406.Russia, Archangeldeposit - Arkhangelskaya

Abstract: The contents of radioactive elements and the uranium isotopic composition of kimberlite in the Arkhangelskaya pipe at the M.V. Lomonosov deposit and of nearby country rocks have been studied. A surplus of 234U isotope has been established in rocks from the near-pipe space. The high ? = 234U/238U ratio is controlled by the geological structure of the near-pipe space. A nonequilibrium uranium halo reaches two pipe diameters in size and can be regarded as a local ore guide for kimberlite discovery. The rocks in the nearpipe space are also characterized by elevated or anomalous U, Th, and K contents with respect to the background.
DS1998-0365
1998
Druzhinin, V.S.Druzhinin, V.S., Karetin, Avtoneev, Gavrilova, TiunovaThe main structures of the crust and upper mantle of the Ural regionDoklady Academy of Sciences, Vol. 360, No. 4, pp. 597-601.Russia, UralsTectonics
DS1985-0157
1985
Dryansky, G.Y.Dryansky, G.Y.The Razzle Dazzle Diamond MarketTown And Country, Vol. 139, No. 5059, PP. 127-128.GlobalMarkets, Diamond
DS1900-0402
1906
Dryer, C.R.Dryer, C.R.The Geologic Features of the Finger Lake RegionScience., NEW SER. Vol. 23, P. 386.United States, Appalachia, New YorkRegional Geology
DS1991-0917
1991
Drynkin, V.I.Kononova, V.A., Sveshnikova, Ye.V., Drynkin, V.I., Gurevich, A.V.Potassic and potassic sodic series of volcanics in the Cenozoic ofYugoslaviaInternational Geology Review, Vol. 33, No. 8, August pp. 793-806YugoslaviaNephelinite, Shoshonite
DS1991-0918
1991
Drynkin, V.I.Kononova, V.A., Sveshnikova, Ye.V., Drynkin, V.I., Gurevich, A.V.Potassic and potassic-sodic series of volcanics in the Cenozoic ofYugoslaviaInternational Geology Review, Vol. 33, No. 8, August pp. 793-806YugoslaviaPotassic rocks, Cenozoic
DS1910-0498
1916
Drysdale, C.W.Drysdale, C.W.Bridge River Map Area, Lillooet DistrictGeological Survey of Canada SUMMARY Report FOR 1915, PP. 75-85.Canada, British ColumbiaBlank
DS201611-2110
2016
Drysdale, R.N.Giuliani, A., Soltys, A., Phillips, D., Kamenetsly, V.S., Maas, R., Geomann, K., Woodhead, J.D., Drysdale, R.N., Griffin, W.L.The final stages of kimberlite petrogenesis: petrography, mineral chemistry, melt inclusions and Sr-C-O isotope geochemistry of the Bultfontein kimberlite ( Kimberley, South Africa).Chemical Geology, in press available 15p.Africa, South AfricaDeposit - Bultfontein

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

Abstract: The petrogenesis of kimberlites is commonly obscured by interaction with hydrothermal fluids, including deuteric (late-magmatic) and/or groundwater components. To provide new constraints on the modification of kimberlite rocks during fluid interaction and the fractionation of kimberlite magmas during crystallisation, we have undertaken a detailed petrographic and geochemical study of a hypabyssal sample (BK) from the Bultfontein kimberlite (Kimberley, South Africa). Sample BK consists of abundant macrocrysts (> 1 mm) and (micro-) phenocrysts of olivine and lesser phlogopite, smaller grains of apatite, serpentinised monticellite, spinel, perovskite, phlogopite and ilmenite in a matrix of calcite, serpentine and dolomite. As in kimberlites worldwide, BK olivine grains consist of cores with variable Mg/Fe ratios, overgrown by rims that host inclusions of groundmass phases (spinel, perovskite, phlogopite) and have constant Mg/Fe, but variable Ni, Mn and Ca concentrations. Primary multiphase inclusions in the outer rims of olivine and in Fe-Ti-rich (‘MUM’) spinel are dominated by dolomite, calcite and alkali carbonates with lesser silicate and oxide minerals. Secondary inclusions in olivine host an assemblage of Na-K carbonates and chlorides. The primary inclusions are interpreted as crystallised alkali-Si-bearing Ca-Mg-rich carbonate melts, whereas secondary inclusions host Na-K-rich C-O-H-Cl fluids. In situ Sr-isotope analyses of groundmass calcite and perovskite reveal similar 87Sr/86Sr ratios to perovskite in the Bultfontein and the other Kimberley kimberlites, i.e. magmatic values. The ?18O composition of the BK bulk carbonate fraction is above the mantle range, whereas the ?13C values are similar to those of mantle-derived magmas. The occurrence of different generations of serpentine and occasional groundmass calcite with high 87Sr/86Sr, and elevated bulk carbonate ?18O values indicate that the kimberlite was overprinted by hydrothermal fluids, which probably included a significant groundwater component. Before this alteration the groundmass included calcite, monticellite, apatite and minor dolomite, phlogopite, spinel, perovskite and ilmenite. Inclusions of groundmass minerals in olivine rims and phlogopite phenocrysts show that olivine and phlogopite also belong to the magmatic assemblage. We therefore suggest that the crystallised kimberlite was produced by an alkali-bearing, phosphorus-rich, silica-dolomitic melt. The alkali-Si-bearing Ca-Mg-rich carbonate compositions of primary melt inclusions in the outer rims of olivine and in spinel grains with evolved compositions (MUM spinel) support formation of these melts after fractionation of abundant olivine, and probably other phases (e.g., ilmenite and chromite). Finally, the similarity between secondary inclusions in kimberlite olivine of this and other worldwide kimberlites and secondary inclusions in minerals of carbonatitic, mafic and felsic magmatic rocks, suggests trapping of residual Na-K-rich C-O-H-Cl fluids after groundmass crystallisation. These residual fluids may have persisted in pore spaces within the largely crystalline BK groundmass and subsequently mixed with larger volumes of external fluids, which triggered serpentine formation and localised carbonate recrystallisation.
DS202204-0521
2022
Drysdale, R.N.Guiliani, A., Drysdale, R.N., Woodhead, J.D., Planavsky, N.J., Phillips, D., Hergt, J., Griffin, W.L., Oesch, S., Dalton, H., Davies, G.R.Pertubation of the deep-Earth carbon cycle in response to the Cambrian explosion.Science Advances, doi.10.1126/sciadv.abj1325 1p. PdfMantlesubduction

Abstract: Earth’s carbon cycle is strongly influenced by subduction of sedimentary material into the mantle. The composition of the sedimentary subduction flux has changed considerably over Earth’s history, but the impact of these changes on the mantle carbon cycle is unclear. Here, we show that the carbon isotopes of kimberlite magmas record a fundamental change in their deep-mantle source compositions during the Phanerozoic Eon. The 13C/12C of kimberlites before ~250 Ma preserves typical mantle values, whereas younger kimberlites exhibit lower and more variable ratios-a switch coincident with a recognized surge in kimberlite magmatism. We attribute these changes to increased deep subduction of organic carbon with low 13C/12C following the Cambrian Explosion when organic carbon deposition in marine sediments increased significantly. These observations demonstrate that biogeochemical processes at Earth’s surface have a profound influence on the deep mantle, revealing an integral link between the deep and shallow carbon cycles.
DS200412-2027
2004
DShevchenko, V.S.Urakaev, F.Kh., Palyanov, Yu.N., DShevchenko, V.S., Sobolev, N.V.Abrasive reactive Mechano chemical synthesis of cohenite with the application of diamond.Doklady Earth Sciences, Vol. 394, 2, pp. 214-218.TechnologyPetrology - experimental
DS201905-1026
2019
Dsmit, K.V.Dsmit, K.V., Stachel, T., Luth, R.W., Stern, R.A.Evaluating mechanisms for eclogitic diamond growth: an example from Zimmi Neoproterozoic diamonds ( West African Craton).Chemical Geology, doi.org/10,1016/j.chem geo.2019.04.014 37p.Africa, Sierra Leonedeposit - Zimmi

Abstract: Here we present SIMS data for a suite of Zimmi sulphide-bearing diamonds that allow us to evaluate the origin and redox-controlled speciation of diamond-forming fluids for these Neoproterozoic eclogitic diamonds. Low ?13C values below ?15‰ in three diamonds result from fluids that originated as carbon in the oceanic crust, and was recycled into the diamond-stable subcratonic lithospheric mantle beneath Zimmi during subduction. ?13C values between ?6.7 and ?8.3‰ in two diamonds are within the range for mantle-derived carbon and could reflect input from mantle fluids, serpentinised peridotite, or homogenised abiogenic and/or biogenic carbon (low ?13C values) and carbonates (high ?13C values) in the oceanic crust. Diamond formation processes in eclogitic assemblages are not well constrained and could occur through redox exchange reactions with the host rock, cooling/depressurisation of CHO fluids or during H2O-loss from CHO fluids. In one Zimmi diamond studied here, a core to rim trend of decreasing ?13C (?23.4 to ?24.5‰) and decreasing [N] is indicative of formation from reduced CH4-bearing fluids. Unlike mixed CH4-CO2 fluids near the water maximum, isochemical diamond precipitation from such reduced CHO fluids will only occur during depressurisation (ascent) and should not produce coherent fractionation trends in single diamonds that reside at constant depth (pressure). Furthermore, due to a low relative proportion of the total carbon in the fluid being precipitated, measurable carbon isotopic variations in diamond are not predicted in this model and therefore cannot be reconciled with the 1‰ internal core-to- rim variation. Consequently, this Zimmi eclogitic diamond showing a coherent trend in ?13C and [N] likely formed through oxidation of methane by the host eclogite, although the mineralogical evidence for this process is currently lacking.
DS202108-1299
2021
Du, C.R.McLaughlin, N.J., Kalcheim, Y., Suceava, A., Wang, H., Schuller, I.K., Du, C.R.Quantum sensing of insulator -to-metal transitions in a Mott Insulator. NV centres in diamondsAdvanced Quantum Technologies, Vol. 4, doi.10.1002/quite.202000142, 6p. PdfGlobaldiamond morphology
DS201903-0517
2019
Du, D-H.Huang, D-L., Wanf, X-L., Xia, X-P., Wan, Y-S., Zhang, F-F., Li, J-Y., Du, D-H.Neoproterozoic low delta 180 zircons revisited: implications for Rodinia configuration.Geophysical Research Letters, Vol. 46, 2, pp. 678-688.Globalcraton

Abstract: Low??18O magma has received great attention and it has profound implications on geological and climate evolution. Neoproterozoic era is a unique period to breed low??18O magmas and snowball Earth. This manuscript first report Neoproterozoic moderately 18O?depleted zircons from the central part of the Cathaysia Block in South China, and it builds a four end?member Hf?O isotopic mixing model to explain the global low??18O magmas at Neoproterozoic era. Our compilation of low??18O zircon data and our new data confirms that globally Neoproterozoic 18O?depleted magmatic activities generally began after 800 Ma and reached a peak at 780-760 Ma. This provides new information on the rifting of Rodinia supercontinent and suggests close connections between northwest India, Madagascar, and South China in the Rodinia supercontinent. This manuscript deals with the hot?debated topics on oxygen isotopes and supercontinent cycle. We believe that this manuscript will attract international readers from a wide scope of geosciences.
DS200812-0688
2008
Du, J.Lu, Z., Zhang, L., Du, J., Bucher, K.Coesite inclusions in garnet from eclogitic rocks in western Tianshan, northwest China: convincing proof of UHP metamorphism.American Mineralogist, Vol. 93, Nov-dec. pp. 1845-1850.ChinaEclogite
DS201212-0232
2012
Du, L.Geng, Y., Du, L., Ren, L.Growth and reworking of the early Precambrian continental crust in the North Chin a Craton: constraints from zircon Hf isotopes.Gondwana Research, Vol. 21, 2-3, pp. 517-529.ChinaMelting
DS202001-0019
2019
Du, L.Huang, Z., Yuan, C., Long, X., Zhang, Y., Du, L.From breakup of Nuna to assembly of Rodinia: a link between the Chinese central Tianshen block and Fennoscandia.Tectonics, Doi.org/10.1029/ 2018TC005471China, Europe, Fennoscandiageochronology

Abstract: The transition from breakup of Nuna (or Columbia, 2.0-1.6 Ga) to assembly of Rodinia (1.0-0.9 Ga) is investigated by means of U?Pb and Lu?Hf data of detrital zircons from three Neoproterozoic metasedimentary rocks in the Central Tianshan Block (CTB), NW China. These data yield six age peaks around 1.0, 1.13, 1.34, 1.4-1.6, 1.75, and 2.6 Ga. Few zircons are detected between 2.0 and 2.5 Ga. The Paleoproterozoic to Neoproterozoic detrital zircons have Hf isotopic compositions (?22.1 to +13.0) similar to those of coeval magmatic rocks in the CTB, indicating a proximal provenance. These results, together with the geological evidence and the presence of 1.4 Ga orogenic granitoids in the CTB, rule out most cratons as the CTB sources but support a Fennoscandia ancestry. Zircon U?Pb ages and Hf isotopic compositions from the CTB and Fennoscandia suggest that from 1.8 to 1.4 Ga, the ?Hf(t) values increased toward more positive values, consistent with an exterior orogen characteristic that the lower crust was replaced by a juvenile arc crust. In contrast, from 1.4 to 0.9 Ga, zircon ?Hf(t) values decreased to more negative values, reflecting an interior orogen, characterized by enhanced contribution of recycled crustal material from collided continental fragments. This marked shift most likely reflected a transition from breakup of Nuna to assembly of Rodinia, accomplished by a transformation from an exterior orogen to an interior one.
DS202102-0192
2021
Du, L.Geng, Y., Du, L., Kuang, H., Liu, Y.Ca. 1.7 Ga magmatism on southwestern margin of the Yangtze block: response to the breakup of Columbia.Acta Geologica Sinica, Vol. 94, 6, pp. 2031-2052.Chinamagmatism

Abstract: This paper presents some data of the Jiaopingdu gabbro and Caiyuanzi granite at the southwestern margin of the Yangtze Block, on the geochemical compositions, zircon LA-ICP-MS U-Pb ages and Hf isotopic data. The Jiaopingdu gabbro gives the age of 1721 ± 5 Ma, the Caiyuanzi granite 1732 ± 6 Ma and 1735 ± 4 Ma, and the Wenjiacun porphyry granite 1713 ± 4 Ma, suggesting nearly contemporaneous formation time of the gabbro and granite. The bimodal feature is demonstrated by the gabbro SiO2 content of 44.64-46.87 wt% and granite 73.81-77.03 wt%. In addition, the granite has high content of SiO2 and Na2O + K2O, low content of Al2O3 and CaO, enriched in REEs (except Eu) and Zr, Nb, Ga and Y, depleted in Sr, implying it belongs to A?type granite geochemistry and origin of within?plate environment. The zircon ?Hf(t) of the granite and gabbro is at the range of 2-6, which is near the 2.0 Ga evolution line of the crust, implying the parent magma of the gabbro being derived from the depleted mantle and a small amount of crustal material, and the parent magma of the granite from partial melting of the juvenile crust and some ancient crustal material at the same time. Compared with 1.8-1.7 Ga magmatism during breakup of other cratons in the world, we can deduce that the Columbia has initially broken since ca. 1.8 Ga, and some continental marginal or intra?continental rifts occurred at ca. 1.73 Ga.
DS202110-1647
2021
Du, L.Zhu, H., Ionov, D.A., Du, L., Zhang, Z., Sun, W.Ca-Sr isotope and chemical evidence for distinct sources of carbonatite and silicate mantle metasomatism.Geochimica et Cosmochimica Acta, Vol. 312, pp. 158-179. pdfEurope, Norwaydeposit - Spitzbergen

Abstract: Enrichments in light REE without concomitant enrichments in high-field-strength elements in mantle peridotites are usually attributed to inputs from carbonate-rich melts and referred to as ‘carbonatite’ metasomatism as opposed to interaction with evolved silicate melts. Alternatively, both enrichment types are ascribed to percolating volatile-bearing mafic liquids whose chemical signatures evolve from ‘silicate’ to ‘carbonatite’. Here we compare these models for peridotites in which these enrichment types are combined, as may be common in the mantle. We report new Ca-Sr-Nd isotope and chemical data for lherzolite and harzburgite xenoliths from Spitsbergen that were metasomatized, first, by silicate, then by carbonate-rich melts that formed carbonate-bearing pockets replacing earlier minerals. Seven crushed samples were treated with acetic acid that dissolved carbonates formed in the latest event, but not silicates. The leachates (acid-removed carbonates making up 0.6-1.4% of total sample mass) contain much more Sr than the residues after leaching (277-2923 vs. 16-60 ppm), have a greater overall 87Sr/86Sr range (0.7049-0.7141 vs. 0.7036-0.7055) and higher 87Sr/86Sr in each sample than the residues. The leachates have lower ?44/40Ca range (0.17-0.68‰) than the residues (0.78-1.00‰), as well as lower ?44/40Ca than the residues in all samples but one. By and large, the carbonates are out of Ca-Sr isotope equilibrium with the host peridotites implying that the older silicate and younger carbonatite metasomatism were produced by different parental melts, thus supporting the existence of distinctive carbonate-rich metasomatic media in the lithospheric mantle, possibly including recycled materials. The ?44/40Ca in the leachates (i.e. carbonates, 0.17-0.68‰) are well below bulk silicate Earth (BSE) estimates (0.94 ± 0.05‰) and ?44/40Ca in non-metasomatized melt-depleted mantle. Yet, ?44/40Ca in the non-leached whole rock (WR) carbonate-bearing samples (0.75-0.95‰) fall within, or are only slightly lower than, the BSE range. The 87Sr/86Sr range in these WR samples (0.7030-0.7112) includes very high values for peridotites with large aggregates of dolomite and Mg-calcite. It appears that both carbonatite and silicate metasomatism may produce ?44/40Ca values lower than the BSE such that Ca-isotope data cannot robustly tell apart these two enrichment types, yet carbonatite metasomatism may yield the lowest ?44/40Ca. Carbonates, even at small mass fractions, are significant hosts of Sr in the WR Spitsbergen peridotites (8-51 wt.% of Sr mass) because of very high Sr concentrations, but add little to WR Ca balance (3-12 wt.%). As a result, high Sr content and 87Sr/86Sr ratios may be indices (though not definitive proofs) of carbonatite metasomatism in mantle rocks.
DS202204-0547
2022
Du, S.Zhang, W., Mei, T., li, B., Yang, L., Du, S., Miao, Y., Chu, H.Effect of current density and agitation modes on the structural and corrosion behavior of Ni/diamond composite coatings. Nanoparticles ( nickel)Journal of Materials Research and Technology, Vol. 12, pp. 1473-1485.Chinananodiamonds

Abstract: In this work, Ni/diamond composite coatings have been synthesized by electrodeposition in direct current mode. The effects of mechanical and ultrasonic agitations on the microstructural, surface characteristics and electrochemical properties have been comparatively investigated by various methods. Results show that diamond nanoparticles have been evenly dispersed in Ni metallic matrix, which could reinforce their performances. The coatings prepared under ultrasonic and mechanical agitation both exhibit compact, dense and hill-valley like morphology with pyramid-like nickel crystallite grains. The relative texture coefficient (RTC) values show that the preferred orientation of the Ni/diamond coating was (200) texture. From 3 to 5 A dm?2, the crystallite sizes of ultrasonic conditions were 59.2-81.7 nm, which were smaller than 76.3-83.2 nm of magnetic agitations. The average roughness (Ra = 78.9-133 nm) of ultrasonic-assisted coatings were lower than 103-139 nm of magnetic conditions. The mechanism of the co-electrodeposition process was proposed. Electrochemical impedance spectroscopy (EIS) results illustrate that the ultrasonic-assisted electrodeposited Ni/diamond coating has better corrosion resistance than that prepared under mechanical stirring conditions. The Ni/diamond composite coatings could be applied as protective materials in harsh mediums.
DS201701-0020
2016
Du, W.Liu, Z., Du, W., Shinmei, T., Greaux, S., Zhou, C., Arimoto, T., Kunimoto, T., Irifune, T.Garnets in the majorite pyrope system: symmetry, lattice microstain, and order-disorder of cations.Physics and Chemistry of Minerals, in press available 9p.TechnologyGarnet morphology

Abstract: We present a systematic experimental study on the phase transition, lattice microstrain, and order-disorder of cations for garnets in the majorite-pyrope system. Polycrystalline gem-quality garnets were synthesized at high pressure and high temperature using a Kawai-type multi-anvil apparatus. A phase transition from a cubic to tetragonal structure is clearly observed for garnets with the majorite content of more than 74 mol % through X-ray diffraction (XRD) and Raman scattering studies. Microstrain of garnets, evaluated with the Williamson-Hall plot on XRD profiles, shows a nonlinear dependence of the garnet compositions. The variation of the XRD peak broadening suggests the lattice microstrain of these garnets may be associated with the local structural heterogeneities due to the substitution of different cations via the coupled substitution (Mg2+ + Si4+ = 2Al3+) in the garnet structure. The width variation of Raman scattering peaks indicates that cation disorder occurs in the garnet structure for intermediate compositions. It is found that intermediate garnets and end-members have a minimum of microstrain, while those between end-members and intermediate compositions possess a larger microstrain.
DS201112-0314
2011
Du, X.Fan, Q., Sui, J., Du, X., Zhao, Y.Genesis of carbonatite from Hannuoba and Yangyuan north China.Goldschmidt Conference 2011, abstract p.827.ChinaMantle evolution
DS201709-2075
2017
Du, X.Wu, M., Du, X., Tse, J.S., Pan, Y.Viscosity of carbonate melts at high pressures and temperatures.Goldschmidt Conference, abstract 1p.Mantlecarbon

Abstract: Knowledge about the viscosity and other transport properties of CaCO3 melts at high pressures and temperatures relevant to the Earth’s mantle is critically important for understanding the deep carbon cycle [1,2]. We have conducted First-Principles Molecular Dynamics Calculations of CaCO3 melts up to 52.5 GPa and 3000 K to provide atomistic insights into the mechanisms of diffusion and viscosity. Our calculated viscosities of CaCO3 melts at low pressures are in good agreement with those from experiments. In particular, viscosity is almost constant at low pressures but increases linearly with pressure above 10 GPa. The ultralow viscosity of CaCO3 melts at low pressures [1] is readily attributed to the uncorrelated diffusion of Ca2+ and CO3 2- ions (Fig. 1). In contrast, the motions of the Ca2+ cations and CO3 2- anions at pressures >10 GPa become increasingly correlated (Fig. 1), leading to higher viscosities. Compared to water, the viscosity of CaCO3 melts is not anomalously low. Rather, the viscosity of water is anomalously high, because water molecules are strongly H-bonded and behave like polymers.
DS201012-0871
2010
Du, Y.Yang, J., Cawood, P.A., Du, Y.Detrital record of mountain building: provenance of Jurassic foreland basin to the Dabie Mountains.Tectonics, Vol. 29, 4, TC4011.ChinaUHP
DS201412-0996
2014
Du, Y.Xu, Y., Cawood, P., Du, Y., Yu, L., Yu, W., Zhu, Y., Li, W.Linking south Chin a to northern Australia and India on the margin of Gondwana: constraints from detrital zircon U-Pb isotopes in Cambrian strata.Tectonics, Vol. 32, 6, pp. 1547-1558.ChinaGeochronology
DS201502-0064
2015
Du, Y.Huang, L., Du, Y., Chen, G.GeoSegmenter: a statistically learned Chinese word segmenter for the geoscience domain.Computers & Geosciences, Vol. 76, pp. 11-17.TechnologyNot specific to diamonds
DS2003-0170
2003
Du, Z.Brooker, R.A., Du, Z., Blundy, J.D., Kelley, S.P., Allan, N.L., Wood, B.J.The zero charge partitioning behaviour of noble gases during mantle meltingNature, No. 6941, June 12, pp. 738-41.MantleBlank
DS2003-0418
2003
Du, Z.Foulger, G.R., Du, Z., Julian, B.R.Iclandic type crustGeophysical Journal International, IcelandBlank
DS200412-0220
2003
Du, Z.Brooker, R.A., Du, Z., Blundy, J.D., Kelley, S.P., Allan, N.L., Wood, B.J., Chamorro, E.M., Wartho, J.A., PurtThe zero charge partitioning behaviour of noble gases during mantle melting.Nature, No. 6941, June 12, pp. 738-41.MantleMelt, geochemistry
DS200412-0487
2004
Du, Z.Du, Z., Foulger, G.R.Surface wave waveform inversion for variation in upper mantle structure beneath Iceland.Geophysical Journal International, Vol. 157, 1, pp. 305-314.Europe, IcelandGeophysics - seismics
DS200412-0570
2003
Du, Z.Foulger, G.R., Du, Z., Julian, B.R.Iclandic type crust.Geophysical Journal International, Vol. 155, pp. 567-590.Europe, IcelandGeophysics - seismics, mantle, plume
DS200512-1145
2005
Du, Z.Vinnick, L.P., Foulger, G.R., Du,Z.Seismic boundaries in the mantle beneath Iceland: a new constraint on temperature.Geophysical Journal International, Vol. 160, 2, pp. 533-538.Europe, IcelandGeophysics - seismics
DS200612-0356
2005
Du, Z.Du, Z., Vinnik, L.P., Foulger, G.R.Evidence from P to S mantle converted waves for a flat '660 km' discontinuity beneath Iceland.Earth and Planetary Science Letters, Vol. 241, 1-2, pp. 271-280.Europe, IcelandPlume, boundary, hot spot
DS201803-0455
2018
Du, Z.Jackson, C.R., Bennett, N.R., Du, Z., Cottrell, E., Fei, Y.Early episodes of high pressure core formation preserved in plume mantle.Nature , Vol. 553, 7689, pp. 491-495.Mantleplumes

Abstract: The decay of short-lived iodine (I) and plutonium (Pu) results in xenon (Xe) isotopic anomalies in the mantle that record Earth’s earliest stages of formation1,2,3,4,5,6,7,8. Xe isotopic anomalies have been linked to degassing during accretion2,3,4, but degassing alone cannot account for the co-occurrence of Xe and tungsten (W) isotopic heterogeneity in plume-derived basalts9,10 and their long-term preservation in the mantle. Here we describe measurements of I partitioning between liquid Fe alloys and liquid silicates at high pressure and temperature and propose that Xe isotopic anomalies found in modern plume rocks (that is, rocks with elevated 3He/4He ratios) result from I/Pu fractionations during early, high-pressure episodes of core formation. Our measurements demonstrate that I becomes progressively more siderophile as pressure increases, so that portions of mantle that experienced high-pressure core formation will have large I/Pu depletions not related to volatility. These portions of mantle could be the source of Xe and W anomalies observed in modern plume-derived basalts2,3,4,9,10. Portions of mantle involved in early high-pressure core formation would also be rich in FeO11,12, and hence denser than ambient mantle. This would aid the long-term preservation of these mantle portions, and potentially points to their modern manifestation within seismically slow, deep mantle reservoirs13 with high 3He/4He ratios.
DS201909-2035
2019
Du, Z.Driscoll, P.E., Du, Z.Geodynamo conductivity limits.Geophysical Research Letters, Vol. 46, 14, pp. 7982-7989.Mantlegeophysics

Abstract: In a metal, as in Earth's core, the thermal and electrical conductivities are assumed to be correlated. In a planetary dynamo this implies a contradiction: that both electrical conductivity, which makes it easier to induce current and magnetic field, and conductive heat transport, which hinders thermal convection, should increase simultaneously. Here we show that this contradiction implies that the magnetic induction rate peaks at a particular value of electrical and thermal conductivity and derive the low? and high?conductivity limits for thermal dynamo action. A dynamo regime diagram is derived as a function of electrical conductivity and temperature for Earth's core that identifies four distinct dynamo regimes: no dynamo, thermal dynamo, compositional dynamo, and thermocompositional dynamo. Estimates for the temperature?dependent electrical conductivity of the core imply that the geodynamo may have come close to its high?conductivity “no dynamo” limit prior to inner core nucleation, consistent with recent paleomagnetic observations.
DS201910-2255
2019
Du, Z.Du, Z., Deng, J., Miyazaki, Y., Mao, H-k., Karki, B.B., Lee, K.K.M.Fate of hydrous Fe-silicate melt in Earth's deep mantle.Geophysical Research Letters, Vol. 46, doi.org/ 10.1029/ 2019GL083633Mantlemelting

Abstract: Planetary?scale melting is ubiquitous after energetic impacts early in Earth's history. Therefore, determining key melt properties, such as density, is of great significance to better understand Earth's formation and subsequent evolution. In this study, we performed state?of?art first?principles molecular dynamics simulations to examine the density of deep mantle melts, namely, hydrous Fe?rich silicate melts. We find that such hydrous melts can be gravitationally stable near Earth's core?mantle boundary given their likely high iron content. This has great implications for Earth's thermochemical evolution, as well as Earth's volatile cycle.
DS201911-2520
2019
Du, Z.Du, Z., Deng, J., Miyazaki, Y., Mao, H-K., Karki, B.B., Lee, K.K.M.Fate of hydrous Fe-rich silicate melt in Earth's deep mantle.Geophysical Research Letters, Vol. 46, 16, pp. 9466-9473.Mantlewater

Abstract: Planetary-scale melting is ubiquitous after energetic impacts early in Earth's history. Therefore, determining key melt properties, such as density, is of great significance to better understand Earth's formation and subsequent evolution. In this study, we performed state-of-art first-principles molecular dynamics simulations to examine the density of deep mantle melts, namely, hydrous Fe-rich silicate melts. We find that such hydrous melts can be gravitationally stable near Earth's core-mantle boundary given their likely high iron content. This has great implications for Earth's thermochemical evolution, as well as Earth's volatile cycle.
DS201412-0327
2014
du Plessis, A.Gurney, J.J., Kahle, R., Kahle, B., Richardson, S.H., du Plessis, A.X-ray Cat scanning of Diamondiferous mantle xenoliths.GSSA Kimberley Diamond Symposium and Trade Show provisional programme, Sept. 12, title onlyTechnologyX-Ray scanning
DS1991-0403
1991
Du Plessis, C.P.Du Plessis, C.P.Some speculations on the nature of Precambrian plates and tectonicsTerra Abstracts, Precambrian Sedimentary Basins of Southern Africa, ed., Vol. 3, suppl. 3 p. 10. AbstractSouth AfricaKimberlites, Kaapvaal craton
DS1988-0669
1988
Du Plessis, J.G.Stettler, E.H., Du Plessis, J.G., De Beer, J.H.The structure of the Pietersburg greenstone belt, South Africa, as derived from geophysicsSouth African Journal of Geology, Vol. 91, No. 2, June pp. 292-303. Database # 17372South AfricaGreenstone Belt, Geophysics
DS200912-0285
2009
Du Plessis, P.Harvey, S., Kjarsgaard, McClintock, M., Shimell, M., Fourie, L., Du Plessis, P., Read, G.Geology and evaluation strategy of the Star and Orion South kimberlites, Fort a la Corne, Canada.Lithos, In press availableCanada, SaskatchewanDeposit - Star, Orion
DS200912-0384
2009
Du Plessis, P.Kjarsgaard, B.A., Harvey, S., McClintock, M., Zonneveld, J.P., Du Plessis, P., McNeil, D., Heaman, L.Geology of the Orion South kimberlite, Fort a la Corne, Canada.Lithos, In press - available formatted 15p.Canada, SaskatchewanDeposit - Orion South
DS1960-0539
1965
Du preez, L.Du preez, L.Electroparamagnetic Resonance and Optical Investigations Of defect Centers in Diamond.Ph.d. Thesis, University Witwatersrand., GlobalDiamond Morphology
DS1992-0396
1992
Du ShizhengDu ShizhengGarnet clinopyroxenite inclusions in the Cenozoic basalts from HeilongjiangProvince, northeast ChinaInternational Symposium Cenozoic Volcanic Rocks Deep seated xenoliths China and its, Abstracts pp. 58-59ChinaInclusions, Garnet clinopyroxenite
DS201605-0831
2016
Du Toit, D.Du Toit, D., Meno, T., Telema, E., Boshoff, P., Hodder, A.Survey systems adopted to improve safety and efficiency at Finsch diamond mine.Diamonds Still Sparkling SAIMM 2016 Conference, Mar. 14-17, pp. 187-196.Africa, South AfricaDeposit - Finsch
DS202106-0935
2021
Du Toit, E.Du Toit, E., Delport, P.W.J.Supplementary mineral resources and mineral reserves reports: readibility and textural choice.saimm.co.za, 10P. PDFAfrica, South Africaeconomics

Abstract: Investing in a mining venture can be risky and stakeholders need transparent, unbiased reports to understand the Mineral Resources and Mineral Reserves a mining company holds. Readability and textual choice can be used consciously to manipulate perceptions, or it can be done unconsciously. This exploratory study investigates the readability and textual choice of supplementary Mineral Resources and Mineral Reserves Reports of companies listed on the Johannesburg Stock Exchange. The results indicate that narrative manipulation occurs in these reports through word choices that make the reports difficult to read, as well as specific narrative selections. This reduces the informational value of the reports. The results of the study will be useful to various stakeholders, such as mining company management, investors, investment specialists, financial analysts, and even employees and the general community, who all use these reports to make important decisions. It is also useful for the preparers of the Mineral Resources and Mineral Reserves Reports, Competent Persons, and other technical specialists to be aware of readability and that certain textual choices can affect the interpretation of these reports. It is recommended that bodies such as the JSE and the SAMREC and SAMVAL Code committees consider adding a plain language requirement to regulations, guidelines, and codes to ensure transparent, unbiased, and objective reports.
DS2001-0828
2001
Du Toit, G.Nesbit, P.Q., Du Toit, G., Mapasa, K., Feldman, C.Evaluation of the Hicom 120 mill at Venetia mineMinerals Eng., Vol. 14, No. 7, pp. 711-21.South AfricaMining - mineral processing, comminution, Deposit - Venetia
DS1995-1589
1995
Du Toit, R.Roering, C., Van Reenen, D.D., Smit, C.A., Du Toit, R.Deep crustal embrittlement and fluid flow during granulite metamorphism in Limpopo Belt, South AfricaJournal of Geology, Vol. 103, No. 6, pp. 673-686South AfricaTectonics, metamorphism,, Limpopo Belt
DS201605-0872
2016
du Toit, R.Mokgalaka, L., Langenhoven, J., du Toit, R.Progress update on the Petra Diamonds' MTS 3D SpatialDB integration and reporting project.Diamonds Still Sparkling SAIMM 2016 Conference, Mar. 14-17, pp. 239-250.Africa, South AfricaMining - applied
DS201605-0913
2016
du Toit, R.Van Strijp, T., Boshoff, P., du Toit, R.How the mining design evolved through stress and deformation modelling at Finsch diamond mine.Diamonds Still Sparkling SAIMM 2016 Conference, Mar. 14-17, pp. 251-262.Africa, South AfricaDeposit - Finsch
DS201412-0211
2014
Du Vanage, G.Du Vanage, G.Debmar Pacific makes port of call in Cape Town. Ship being repaired and outfitted for another 30 month stint at sea. Engineering and Mining Journaj, May pp. 42-44Africa, NamibiaNamdeb deep sea mining
DS2001-0271
2001
Du Vignaux, N.M.Du Vignaux, N.M., Fleitout, L.Stretching and mixing of viscous blobs in Earth's mantleJournal of Geophysical Research, Vol. 106, No. 12, pp. 30,893-908.MantleTectonics, Rheology
DS201809-2016
2018
DuanDuan, Yunfei, Sun, Ningyu, Wang, Siheng, Li, Xinyang, Guo, Xuan, Ni.Phase stability and thermal equation of state of delta -AIOOH: implication for water transportation in the deep lower mantle.Earth and Planetary Science Letters, Vol. 494, 1, pp. 92-98.Mantlewater

Abstract: In this study, we present new experimental constraints on the phase stability and thermal equation of state of an important hydrous phase, ?-AlOOH, using synchrotron X-ray diffraction up to 142 GPa and 2500 K. Our experimental results have shown that ?-AlOOH remains stable at the whole mantle pressure-temperature conditions above the D? layer yet will decompose at the core-mantle boundary because of a dramatic increase in temperature from the silicate mantle to the metallic outer core. At the bottom transition zone and top lower mantle, the formation of ?-AlOOH by the decomposition of phase Egg is associated with a ?2.1-2.5% increase in density (?) and a ?19.7-20.4% increase in bulk sound velocity (V?). The increase in ? across the phase Egg to ?-AlOOH phase transition can facilitate the subduction of ?-AlOOH to the lower mantle. Compared to major lower-mantle phases, ?-AlOOH has the lowest ? but greatest V?, leading to an anomalous low ? /V? ratio which can help to identify the potential presence of ?-AlOOH in the region. More importantly, water released from the breakdown of ?-AlOOH at the core-mantle boundary could lower the solidus of the pyrolitic mantle to cause partial melting and/or react with Fe in the region to form the low-velocity FeO2Hx phase. The presence of partial melting and/or the accumulation of FeO2Hx phase at the CMB could be the cause for the ultra-low velocity zone. ?-AlOOH is thus an important phase to transport water to the lowermost mantle and helps to understand the origin of the ultra-low velocity zone.
DS201805-0981
2018
Duan, Y.Sun, N., Wei, W., Han, S., Song, J., Li, X., Duan, Y., Prakapenka, V.B., Mao, Z.Phase transition and thermal equations of state of (Fe, Al) -bridgmanite and post perovskite: implication for the chemical heterogeneity at the lowermost mantle.Earth Planetary Science Letters, Vol. 490, pp. 161-169.Mantleperovskite
DS201901-0083
2018
Duan, Y.Sun, N., Wei, W., Han, S., Song, J., Li, X, Duan, Y., Prakapenka, V.B., Mao, Z.Phase transition and thermal equations of state of ( Fe, Al) - bridgmanite and post-perovskite: implication for the chemical heterogeneity at the lowermost mantle.Earth and Planetary Science Letters, Vol. 490, 1, pp. 161-169.Mantlegeothermometry

Abstract: In this study, we have determined the phase boundary between Mg0.735Fe0.21Al0.07Si0.965O3-Bm and PPv and the thermal equations of state of both phases up to 202 GPa and 2600 K using synchrotron X-ray diffraction in laser heated diamond anvil cells. Our experimental results have shown that the combined effect of Fe and Al produces a wide two-phase coexistence region with a thickness of 26 GPa (410 km) at 2200 K, and addition of Fe lowers the onset transition pressure to 98 GPa at 2000 K, consistent with previous experimental results. Furthermore, addition of Fe was noted to reduce the density (?) and bulk sound velocity () contrasts across the Bm-PPv phase transition, which is in contrast to the effect of Al. Using the obtained phase diagram and thermal equations of state of Bm and PPv, we have also examined the effect of composition variations on the ? and profiles of the lowermost mantle. Our modeling results have shown that the pyrolitic lowermost mantle should be highly heterogeneous in composition and temperature laterally to match the observed variations in the depth and seismic signatures of the D? discontinuity. Normal mantle in a pyrolitic composition with ?10% Fe and Al in Bm and PPv will lack clear seismic signature of the D? discontinuity because the broad phase boundary could smooth the velocity contrast between Bm and PPv. On the other hand, Fe-enriched regions close to the cold slabs may show a seismic signature with a change in the velocity slope of the D? discontinuity, consistent with recent seismic observations beneath the eastern Alaska. Only regions depleted in Fe and Al near the cold slabs would show a sharp change in velocity. Fe in such regions could be removed to the outer core by strong core-mantle interactions or partitions together with Al to the high-pressure phases in the subduction mid ocean ridge basalts. Our results thus have profound implication for the composition of the lowermost mantle.
DS200912-0851
2009
Duan, Z.Zhang, C., Duan, Z.A model for C O H fluid in the Earth's mantle.Geochimica et Cosmochimica Acta, Vol. 73, 7, pp. 2089-2102.MantleWater
DS1986-0196
1986
Duane, M.Duane, M.The Argyle lamproite diamond deposits, Kimberley basin, Western Australia.Brief outline (1/2p.) of talk to Barberton MountaIn land Branch meeting Nov.27, 1985GeoBulletin, Vol. 29, No. 1, p. 16AustraliaLamproite
DS1994-0218
1994
Duane, M.Brown, R., Gallagher, K., Duane, M.A quantitative assessment of the effects of magmatism on the thermal history of the Karoo sediment sequenceJournal of African Earth Sciences, Vol. 18, No. 3, April pp. 245-254South AfricaMagmatism, Karoo sedimentology
DS1994-0219
1994
Duane, M.Brown, R., Gallagher, K., Duane, M.A quantitative assessment of effects of magmatism on the thermal history Of the Karoo sedimentary sequenceJourn. African Earth Sciences, Vol. 18, No. 3, pp. 227-243South AfricaMagmatism, Paleotemperatures
DS1991-0404
1991
Duane, M.J.Duane, M.J., Kruger, F.J.Geochronological evidence for tectonically driven brine migration During the early Proterozoic Rheis orogeny of southern AfricaGeophysical Research Letters, Vol. 18, No. 5, May pp. 975-978Southern AfricaGeochronology, Brine
DS201710-2257
2017
Duarte, B.J.R.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.
DS201507-0310
2015
Duarte, J.C.Edwards, S.J., Schellart, W.P., Duarte, J.C.Geodynamic models of continental subduction and obduction of overriding plate forearc oceanic lithosphere on top of continental crust.Tectonics, Vol. 34, 7, pp. 1494-1515.New ZealandSubduction
DS201611-2101
2016
Duarte, J.C.Chen, Z., Schellart, W.P., Strak, V., Duarte, J.C.Does subduction induced mantle flow drive backarc extension?Earth and Planetary Science Letters, Vol. 441, pp. 200-210.MantleSubduction

Abstract: Subduction zones are one of the most striking feature on Earth. They represent one of the two types of convergent plate boundaries, in which one tectonic plates sinks underneath another into the Earth’s mantle. Soon after the advent of the theory of plate tectonics scientists recognized that subduction zones are one of the main drivers of plate motion and mantle convection [Elsasser, 1971]. With trench motion during progressive subduction, overriding plates incorporated in subduction zones may follow the trench and/or deform internally. Such deformation is often characterized by backarc extension, which leads to opening of backarc basins, such as the Tyrrhenian Sea, the Scotia Sea, the Aegean Sea, the North Fiji Basin, and the Lau Basin.
DS1992-0294
1992
Duba, A.Constable, S., Shankland, T.J., Duba, A.The electrical conductivity of an isotropic olivine mantleJournal of Geophysical Research, Vol. 97, No. B3, March 10, pp. 3393-3404MantleGeophysics, Olivine
DS1992-0397
1992
Duba, A.Duba, A.Earth's core not so hotNature, Vol. 359, No. 6392, September 17, pp. 197-198GlobalMantle, Core melting points
DS1994-0460
1994
Duba, A.Duba, A., Heikamp, S., Meurer, W., NOver, G., Will, G.Evidence from borehole samples for the role of accessory minerals in lower crustal conductivity.Nature, Vol. 367, No. 6458, January 6, pp. 59-61.MantleSubduction
DS2000-0049
2000
Duba, A.Bahr, K., Duba, A.Is the asthenosphere electrically anisotropic?Earth and Planetary Science Letters, Vol. 178, No. 1-2, May 15, pp.87-96.MantleGeophysics
DS1998-1323
1998
Duba, A.G.Shankland, T.J., Duba, A.G.Hydrogen and electrical conductivity of mantle olivineTerra Nova, Abstracts, Vol. 10, suppl. 1, 58. abstractMantle, CaliforniaOlivine, San Carlos
DS2000-1034
2000
Duba, A.G.Xu, Y., Shankland, T.J., Duba, A.G.Pressure effect on electrical conductivity of mantle olivinePhysical Earth and Planetary Interiors, Vol. 118, No.1-2, pp. 149-61.MantleGeophysics, Olivine
DS200412-1903
2003
Dubach, K.St.Onge, M.R., Wodicka, N., Scott, D.J., Corrigan, D., Carmichael, D.M., Dubach, K., Berniolles, F., Begin, N.Thermal architecture of a continent-continent collision zone: a Superior to Rae Craton transect of Trans-Hudson Orogen ( Quebec-Geological Association of Canada Annual Meeting, Abstract onlyCanada, QuebecGeothermometry
DS201012-0081
2009
DubeBurns, R.C., Chumakov, A.I., Connell, Dube, Godfried, Hansen, Hartwig, Hoszowska, Masiello, Mkonza, RebakHPHT growth and x-ray characterization of the high quality type IIa diamond.Journal of Physics Condensed Matter, Vol. 21, 36, pp. 364224-364237.TechnologyType II a
DS200412-1187
2004
Dube, B.Lydon, J.W., Goodfellow, W.D., Dube, B., Paradis, S., Sinclair, W.D., Corrivea, L., Gosselin, P.A preliminary overview of Canada's mineral resources. ( Diamond mentioned).Geological Survey of Canada, Open File 4668, 1 CD $ 20.00 ( pfd of poster, 20p. reptCanadaPoster - resources
DS202007-1137
2020
Dube, J-M.Dube, J-M., Darbyshire, F.A., Liddell, M.V., Stephenson, R.Seismic anisotropy of the Canadian High Arctic: evidence from shear wave splitting.Tectonophysics, Vol. 789, 228524, 13p. PdfCanada, Arcticgeophysics - seismics

Abstract: The Canadian High Arctic preserves a long and complex tectonic history, including craton formation, multiple periods of orogenesis, extension and basin formation, and the development of a passive continental margin. We investigate the possible preservation of deformational structures throughout the High Arctic subcontinental lithosphere using measurements of seismic anisotropy from shear wave splitting at 11 seismograph stations across the region, including a N-S transect along Ellesmere Island. The majority of measurements indicate a fast-polarisation orientation that parallels tectonic trends and boundaries, suggesting that lithospheric deformation is the dominant source of seismic anisotropy in the High Arctic; however, a sub-lithospheric contribution cannot be ruled out. Beneath Resolute in the central Canadian Arctic, distinct back-azimuthal variations in splitting parameters can be explained by two anisotropic layers. The upper layer is oriented E-W and correlates with tectonic trends and the inferred lithospheric deformation history of the region. The lower layer has a ?NNE-SSW orientation and may arise from present-day convective mantle flow beneath locally-thinned continental lithosphere. In addition to inferences of anisotropic structure beneath the Canadian High Arctic, measurements from the far north of our study region suggest the presence of an anisotropic zone in the lowermost mantle beneath northwest Alaska.
DS1985-0158
1985
Dubeau, M.I.Dubeau, M.I., Edgar, A.D.The Stability of Priderite Up to 30 Kb: Inferences on its Potential As a Reservoir for K, Ba and Ti in Mantle Sources For Lamproitic Magmas.Geological Association of Canada (GAC)., Vol. 10, P. A15, (abstract.).GlobalExperimental Petrology
DS1985-0159
1985
Dubeau, M.L.Dubeau, M.L., Edgar, A.D.Priderite Stability in the System K2mgti7o16 - Ba Mg7o16Mineralogical Magazine, Vol. 49, pp. 603-606AustraliaLamproite, Priderite
DS201312-0229
2013
Dube-Loubert, H.Dube-Loubert, H., Roy, M., Allard, G., Lamothe, M., Veilette, J.J.Glacial and nonglacial events in the eastern James Bay lowlands, Canada.Canadian Journal of Earth Sciences, Vol. 50, 4, pp. 379-396.Canada, Ontario, QuebecGeomorphology
DS1984-0153
1984
Dubessy, J.Bergman, S.C., Dubessy, J.Co2 Co Fluid Inclusions in a Composite Peridotite Xenolith:implications for Upper Mantle Oxygen Fugacity.Contributions to Mineralogy and Petrology, Vol. 85, PP. 1-13.United States, NevadaLunar Crater, Spectroscopy, Mineral Chemistry
DS1986-0762
1986
Dubessy, J.Sobolev, A.V., Sobolev, N.V., Smith, C.B., Dubessy, J.Pecularities in the fluid and melt compositions of the lamproites And kimberlites based on the study of inclusions inolivinesProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 93-94Australia, Russia, ArkansasLamproite
DS1989-1419
1989
Dubessy, J.Sobolev, A.V., Sobolev, N.V., Smith, C.B., Dubessy, J.Fluid and melt compositions in lamproites And kimberlites based on the study of inclusions inolivineGeological Society of Australia Inc. Blackwell Scientific Publishing, Special, No. 14, Vol. 1, pp. 220-240Australia, RussiaEllendale, Mt. Cedric, Udachnaya, Geochemistry
DS201709-1984
2017
Dubessy, J.Feneyrol, J., Giuliani, G., Demaiffe, D., Ohenstetter, D., Fallick, A.E., Dubessy, J., Martelet, J-E., Rakotondrazafy, A.F.M., Omito, E., Ichangi, D., Nyamai, C., Wamunyu, W.Age and origin of the tsavorite and tanzanite mineralozing fluids in the Neoproterozoic Mozambique metamorphic belt.The Canadian Mineralogist, Vol. 55, pp. 763-786.Africa, Kenya, Tanzania, Madagascartanzanite

Abstract: The genetic model previously proposed for tsavorite- (and tanzanite-) bearing mineralization hosted in the Neoproterozoic Metamorphic Mozambique Belt (stretching from Kenya through Tanzania to Madagascar) is refined on the basis of new Sm-Nd age determinations and detailed Sr-O-S isotope and fluid-inclusion studies. The deposits are hosted within meta-sedimentary series composed of quartzites, graphitic gneisses, calc-silicate rocks intercalated with meta-evaporites, and marbles. Tsavorite occurs either in nodules (also called “boudins”) oriented parallel to the metamorphic foliation in all of the deposits in the metamorphic belt or in quartz veins and lenses located at the hinges of anticlinal folds (Lelatema fold belt and Ruangwa deposits, Tanzania). Gem tanzanite occurs in pockets and lenses in the Lelatema fold belt of northern Tanzania. The Sm-Nd isotopic data for tsavorites and tanzanites hosted in quartz veins and lenses from Merelani demonstrate that they formed at 600 Ma, during the retrograde metamorphic episode associated with the East African Orogeny. The tsavorites hosted in nodules do not provide reliable ages: their sedimentary protoliths had heterogeneous compositions and their Sm-Nd system was not completely rehomogenized, even at the local scale, by the fluid-absent metamorphic recrystallization. The initial 87Sr/86Sr isotopic ratios of calcite from marble and tanzanites from Merelani fit with the strontium isotopic composition of Neoproterozoic marine carbonates. Seawater sediment deposition in the Mozambique Ocean took place around 720 Ma. The quartz-zoisite O-isotopic thermometer indicates a temperature of formation for zoisite between 385 and 448 °C. The sulfur isotopic composition of pyrite (between –7.8 and –1.3‰ V-CDT) associated with tsavorite in the Lelatema fold belt deposits suggests the contribution of reduced marine sulfate. The sulfur in pyrite in the marbles was likely derived from bacterial sulfate reduction which produced H2S. Fluid inclusion data from tsavorite and tanzanite samples from the Merelani mine indicate the presence of a dominant H2S-S8±(CH4)±(N2)±(H2O)-bearing fluid. In the deposits in Kenya and Madagascar, the replacement of sulfate by tsavorite in the nodules and the boron isotopic composition of tourmaline associated with tsavorite are strong arguments in favor of the participation of evaporites in garnet formation.
DS200812-0188
2008
Dubey, C.S.Cathos, E.J., Dubey, C.S., Sivasubramanian, P.Monazite ages from carbonatites and high grade assemblages along the Kambam Fault ( Southern Granulite Terrane, South India).American Mineralogist, Vol. 93, 8-9, pp. 1230-1244.IndiaCarbonatite
DS1940-0205
1949
Dubey, V.S.Dubey, V.S., Merh, S.Diamondiferous Plug of Majhgawan in Central IndiaGeol. Min. Met. Soc. India Quarterly Journal, Vol. 21, PP. 1-6.India, Madhya PradeshGeology
DS1990-0467
1990
Dubik, F.Yu.Fedorov, P.I., Dubik, F.Yu.The late Cretaceous shoshonitic assemblage of central KamchatkaInternational Geology Review, Vol. 32, No. 10, October pp. 972-980RussiaShoshonites, Related rocks
DS200812-0863
2008
Dubinchuk, V.A.T.A.Patyk-Kara, N.A.G.A., Andrianova, E.A.A.A., Dubinchuk, V.A.T.A.Secondary alterations of zircons in placers.Doklady Earth Sciences, Vol. 419, 1, pp. 253-256.RussiaAlluvials, not specific to diamonds
DS200812-0864
2008
Dubinchuk, V.A.T.A.Patyk-Kara, N.A.G.A., Andrianova, E.A.A.A., Dubinchuk, V.A.T.A.Secondary alterations of zircons in placers.Doklady Earth Sciences, Vol. 419, 2, pp. 253-256.RussiaAlluvials, zircon, Not specific to diamonds
DS1990-0241
1990
Dubinchuk, V.T.Brodin, B.V., Shulgin, A.S., Dubinchuk, V.T., Sidorenko, G.A.The mineralogy of low temperature hydrothermal molybdenum depositsInternational Geology Review, Vol. 32, No. 11, November pp. 1156-1165RussiaMolybdenuM., Mineralogy
DS200812-1069
2008
Dubinchuk, V.T.Simakov, S.K., Dubinchuk, V.T., Novikov, M.P., Drozdova, I.A.Formation of diamond and diamond type phases from the carbon bearing fluid at PT parameters correspondoing to processes in the Earth's crust.Doklady Earth Sciences, Vol. 421, 1, pp. 835-837.MantleDiamond genesis
DS201012-0173
2010
Dubinchuk, V.T.Dubinchuk, V.T., Simakov, S.K., Pechnikov, V.A.Lonsdaleite in diamond bearing metamorphic rocks of the Kokchetav massif.Doklady Earth Sciences, Vol. 430, 1, pp. 40-42.RussiaUHP Mineralogy
DS202110-1620
2021
Dubinina, E.Korolev, N., Nikitina, L.P., Goncharov, A.,Dubinina, E., Melnik, A.E., Muller, D., Chen, Y-X., Zinchenko, V.Three types of mantle eclogite from two layers of oceanic crust: a key case of metasomatically- aided transformation of low-to-high-magnesian eclogite.Journal of Petrology, 10.1093/petrology /egab070 98p. PdfAfrica, Angoladeposit - Catoca

Abstract: Reconstructed whole-rock and mineral major- and trace-element compositions, as well as new oxygen isotope data, for 22 mantle eclogite xenoliths from the Catoca pipe (Kasai Craton) were used to constrain their genesis and evolution. On the basis of mineralogical and major-element compositions, the Catoca eclogites can be divided into three groups: high-alumina (high-Al) (kyanite-bearing), low-magnesian (low-Mg#), and high-magnesian (high-Mg#) eclogites. The high-Al Catoca eclogites contain kyanite and corundum; high Al2O3 contents in rock-forming minerals; rare earth element (REE) patterns in garnets showing depleted LREEs, positive Eu anomalies (1.03-1.66), and near-flat HREEs; and high Sr contents in garnets and whole-rock REE compositions. All of these features point to a plagioclase-rich protolith (probably gabbro). Reconstructed whole-rock compositions (major elements, MREEs, HREEs, Li, V, Hf, Y, Zr, and Pb) and ?18O of 5.5-7.4‰ of the low-Mg# Catoca eclogites are in good agreement with the compositions of picrite basalts and average mid-ocean ridge basalt (MORB). The depleted LREEs and NMORB-normalised Nd/Yb values of 0.07-0.41 indicate that the degree of partial melting for the majority of the low-Mg# eclogites protolith was ?30%. The narrow ?18O range of 5.5-7.4‰ near the ‘gabbro-basalt’ boundary (6‰) obtained for the high-Al and low-Mg# Catoca eclogites reflects the influence of subduction-related processes. This case shows that mantle eclogites represented by two different lithologies and originating from different protoliths — plagioclase-rich precursor, presumably gabbro (for high-Al eclogites), and basalt (low-Mg# eclogites) — can provide similar and overlapping ?18O signatures on account of the influence of subduction-related processes. Chemical compositions of the high-Mg# eclogites indicate a complicated petrogenesis, and textural signatures reveal recrystallisation. The presence of Nb-rich rutile (8-12 wt% of Nb2O5) enriched with HFSE (Zr/Hf of 72.6-75.6) and multiple trace-element signatures (including reconstructed whole-rock NMORB-normalised Ce/Yb of 3.9-10.6 and Sr/Y of 5.8-9.6, MgO contents of 15.7-17.9 wt%, and high Ba and Sr) provide strong evidence for deep metasomatic alteration. High Cr contents in clinopyroxene (800-3740 ppm), garnet (430-1400 ppm), and accessory rutile (700-2530 ppm), together with extremely low Li contents of 1.0-2.4 ppm in clinopyroxene, may indicate hybridisation of the eclogites with peridotite. Comparison of the chemical compositions (major and trace elements) of (1) unaltered fresh cores of coarse-grained garnets from the low-Mg# eclogites, (2) secondary garnet rims (ubiquitous in the low-Mg# eclogites), (3) proto-cores in the coarse-grained garnet (high-Mg# eclogites), and (4) homogeneous recrystallised fine-grained garnets (high-Mg# eclogites) suggests that the high-Mg# eclogites formed through recrystallisation of low-Mg# eclogite in the presence of an external fluid in the mantle. Four of the five high-Mg# samples show that mantle metasomatism inside the Kasai craton mantle beneath the Catoca pipe occurred at a depth range of 145-160 km (4.5-4.8 GPa).
DS200812-0122
2008
Dubinina, E.O.Bogatikov, O.A., Kononova, V.A., Dubinina, E.O., Nosova, A.A., Kondrashov, I.A.Nature of carbonates from kimberlites of the Zimnii Bereg field, Arkangelsk: evidence from Rb Sr C and O isotope data.Doklady Earth Sciences, Vol. 421,1, pp. 807-811.Russia, Kola Peninsula, ArchangelDeposit - Zimnii Bereg
DS201705-0863
2017
Dubinina, E.O.Nosova, A.A., Dubinina, E.O., Sazonova, L.V., Vargin, A.V., lebedeva, N.M., Khvostikov, V.A., Burmii, Zh.P., Kondrashov, I.A., Tretyachenko, V.V.Geochemistry and oxygen isotopic composition of olivine in kimberlites from the Arkhangelsk Province: contribution of mantle metasomatism.Petrology, Vol. 25, 2, pp. 150-180.Russia, Archangel, Kola PeninsulaDeposit - Grib, Pionerskaya

Abstract: The paper presents data on the composition of olivine macrocrysts from two Devonian kimberlite pipes in the Arkhangelsk diamond province: the Grib pipe (whose kimberlite belongs to type I) and Pionerskaya pipe (whose kimberlite is of type II, i.e., orangeite). The dominant olivine macrocrysts in kimberlites from the two pipes significantly differ in geochemical and isotopic parameters. Olivine macrocrysts in kimberlite from the Grib pipe are dominated by magnesian (Mg# = 0.92-0.93), Ti-poor (Ti < 70 ppm) olivine possessing low Ti/Na (0.05-0.23), Zr/Nb (0.28-0.80), and Zn/Cu (3-20) ratios and low Li concentrations (1.2-2.0 ppm), and the oxygen isotopic composition of this olivine ?18O = 5.64‰ is higher than that of olivine in mantle peridotites (?18O = 5.18 ± 0.28‰). Olivine macrocrysts in kimberlite from the Pionerskaya pipe are dominated by varieties with broadly varying Mg# = 0.90-0.93, high Ti concentrations (100-300 ppm), high ratios Ti/Na (0.90-2.39), Zr/Nb (0.31-1.96), and Zn/Cu (12-56), elevated Li concentrations (1.9-3.4 ppm), and oxygen isotopic composition ?18O = 5.34‰ corresponding to that of olivine in mantle peridotites. The geochemical and isotopic traits of low-Ti olivine macrocrysts from the Grib pipe are interpreted as evidence that the olivine interacted with carbonate-rich melts/fluids. This conclusion is consistent with the geochemical parameters of model melt in equilibrium with the low-Ti olivine that are similar to those of deep carbonatite melts. Our calculations indicate that the variations in the ?18O of the olivine relative the “mantle range” (toward both higher and lower values) can be fairly significant: from 4 to 7‰ depending on the composition of the carbonate fluid. These variations were formed at interaction with carbonate fluid, whose ?18O values do not extend outside the range typical of mantle carbonates. The geochemical parameters of high-Ti olivine macrocrysts from the Grib pipe suggest that their origin was controlled by the silicate (water-silicate) component. This olivine is characterized by a zoned Ti distribution, with the configuration of this distribution between the cores of the crystals and their outer zones showing that the zoning of the cores and outer zones is independent and was produced during two episodes of reaction interaction between the olivine and melt/fluid. The younger episode (when the outer zone was formed) likely involved interaction with kimberlite melt. The transformation of the composition of the cores during the older episode may have been of metasomatic nature, as follows from the fact that the composition varies from grain to grain. The metasomatic episode most likely occurred shortly before the kimberlite melt was emplaced and was related to the partial melting of pyroxenite source material.
DS202005-0754
2020
Dubinina, E.O.Nosova, A.A., Kargin, A.V., Sazonova, L.V., Dubinina, E.O., Chugaev, A.V., Lebedeva, N.M., Yudin, D.S., Larionova, Y.O., Abersteiner, A., Gareev, B.I., Batalin, G.A.Sr-Nd-Pb isotopic systematic and geochronology of ultramafic alkaline magmatism of the southwestern margin of the Siberian craton: metasomatism of the sub-continental lithospheric mantle related to subduction and plume events.Lithos, Vol. 364-365, 21p. PdfRussia, Siberiadeposit - Ilbokich, Chadobets

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

Abstract: To provide new insights into the origin and evolution of ultramafic lamprophyres (UMLs) and their mantle source, we examined two UML (aillikite and damtjernite) occurrences of different ages in the western portion of the Siberian Craton (Ilbokich and Chadobets). New age, mineral and rock geochemistry, along with Sr-Nd-Pb-C-O isotope data was obtained. Our new 206Pb/238U perovskite age (399 ± 4 Ma) confirms the previously published Early Devonian age of the Ilbokich aillikite. RbSr isochron and 40Ar/39Ar dating yielded a Middle Triassic age (243 ± 3 Ma and 241 ± 1 Ma, respectively) for the Chadobets aillikites, indicating post-Trap emplacement of these rocks. Both UMLs are characterized by incompatible elements, including light rare earth element (LREE) enrichments (La is up to ×200 chondrite concentration), and strong fractionation of REEs ((La/Yb)n: 33-84). Despite the close geochemical affinity of both UMLs, the Nd isotopic compositions of aillikites, as well as the Pb isotopic composition of Chadobets and Ilbokich UMLs, do not overlap and are distinctly different from each other. The initial Sr and Nd isotopic compositions of the Ilbokich UMLs fall in within a narrow 87Sr/86Sr0 range (0.7032-0.7042) and ?Nd(T) (4.03-3.97). Chadobets UMLs have a similar Sr isotopic signature (87Sr/86Sr0: 0.7031-0.7043) and a more depleted Nd isotopic signature (?Nd(T) 4.09-5.08). The initial Pb isotope compositions of the Chadobets UMLs are moderately radiogenic, ranging between 206Pb/204Pb = 18.4-19.0, 208Pb/204Pb = 38.3-38.8, and are characterized by a narrow 207Pb/204Pb ratio between 15.5 and 15.6. The Ilbokich Pb isotope compositions are less variable and range between 206Pb/204Pb = 18.0-18.4, 208Pb/204Pb = 37.8-38.4 and 207Pb/204Pb ratios between 15.5 and 15.6. The oxygen isotopic composition of carbonate from both UMLs is characterized by highly variable ?18O values from +12.1 and up to +20.5‰ (SMOW). The isotopic composition of ?13C values range from ?1.3‰ to ?7.1. Based on the minor impact of crustal contamination in both aillikites, it is inferred that their radiogenic isotope composition reflects a mantle source signature. The mantle source of the Chadobets aillikites is likely to include carbonatitic magma as a metasomatic agent. In contrast, phlogopite-rich metasomes within the lithospheric mantle could have contributed more significantly to the Ilbokich aillikites. These metasomes could be formed during the Caledonian orogeny, which did not only affect the southwestern boundary of the Siberian Craton, but also expanded to the craton interior. This study provides additional support for the evolution of the south-western portion of the Siberian SCLM, ranging from mantle containing phlogopite enrichment domains during the Early Devonian to hydrous-phase reduced mantle in the Triassic due to the thermal impact of the Siberian Traps.
DS202010-1843
2020
Dubinina, E.O.Erofeeva, K.G., Samsonov, A.V., Stepanova, A.V., Larionova, Yu.O., Dubinina, E.O., Egorova, S.V., Arzamastesev, A.A., Kovalchuk, E.V., Abramova, V.D.Olivine and clinopyroxene phenocrysts as a proxy for the origin and crustal evolution of primary mantle melts: a case study of 2.40 Ga mafic sills in the Kola-Norwegian Terrane, northern Fennoscandia.Petrology, Vol. 28, 4, pp. 338-356. pdfEurope, Norway, Kola Peninsulamelting

Abstract: New petrographic, geochemical, and isotopic (Sr, Nd, and ?18?) data on olivine and pyroxene phenocrysts provide constraints on the composition and crustal evolution of primary melts of Paleoproterozoic (2.40 Ga) picrodoleritic sills in the northwest Kola province, Fennoscandian Shield. The picrodolerites form differentiated sills with S-shaped compositional profiles. Their chilled margins comprise porphyritic picrodolerite (upper margin) and olivine gabbronorite (bottom) with olivine and clinopyroxene phenocrysts. Analysis of the available data allows us to recognize three main stages in the crystallization of mineral assemblages. The central parts of large (up to 2 mm) olivine phenocrysts (Ol-1-C) crystallized at the early stage. This olivine (Mg# 85-92) is enriched in Ni (from 2845 to 3419 ppm), has stable Ni/Mg ratio, low Ti, Mn and Co concentrations, and contains tiny (up to 10 ?m) diopside-spinel dendritic lamella that probably originated due to the exsolution from high Ca- and Cr- primary magmatic olivine. All these features of Ol-1-C are typical of olivine from primitive picritic and komatiitic magmas (De Hoog et al., 2010; Asafov et al., 2018). Ol-1-C contains large (up to 0.25 mm) crystalline inclusions of high-Al enstatite (Mg# 80-88) and clinopyroxene (Mg# 82-90), occasionally in association with Ti-pargasite and chromian spinel (60.4 wt.% Al2O3). These inclusions are regarded as microxenoliths of wall rock that were captured by primary melt at depths more than 30 km and preserved due to the conservation in magmatic olivine. The second stage was responsible for the crystallization of Ol-1 rim (Ol-1-R), small (up to 0.3 mm) olivine (Ol-2, Mg# 76-85) grains, and central parts of large (up to 1.5 mm) clinopyroxene (Cpx-C) phenocrysts in the mid-crustal transitional magma chamber (at a depth of 15-20 km) at 1160-1350°C. At the third stage, Cpx-C phenocrysts were overgrown by low-Mg rims (Mg# 70-72) similar in composition to the groundmass clinopyroxene from chilled picrodolerite and gabbro-dolerite in the central parts of the sills. This stage likely completed the evolution of picrodoleritic magma and occurred in the upper crust at a depth of about 5 km. All stages of picrodoleritic magma crystallization were accompanied by contamination. Primary melts were contaminated by upper mantle and/or lower crust as recognized from xenocrystic inclusions in Ol-1-C. The second contamination stage is supported by the negative values of ?Nd(2.40) = -1.1 in clinopyroxene phenocrysts. At the third stage, contamination likely occurred in the upper crust when ascending melts filled gentle fractures. This caused vertical whole-rock Nd heterogeneity in the sills (Erofeeva et al., 2019), and difference in Nd isotopic composition of clinopyroxene phenocrysts and doleritic groundmass. It was also recognized that residual evolved melts are enriched in radiogenic strontium but have neodymium isotopic composition similar to other samples. It could be explained by the interaction of the melts with fluid formed via decomposition of biotite from surrounding gneisses under the effect of high-temperature melts.
DS202112-1934
2021
Dubinina, V.N.Korolev, N., Nikitina, L.P., Goncharov, A., Dubinina, V.N., Melnik, A., Muller, D., Chen, Y-X., Zinchenko, V.N.Three types of mantle eclogite from two layers of oceanic crust: a key case of metasomatically-aided transformation of low-to-high-magnesian eclogite.Journal of Petrology, Vol. 62, 11, pp. 1-38. pdfAfrica, Angoladeposit - Catoca

Abstract: Reconstructed whole-rock (RWR) and mineral major- and trace-element compositions, as well as new oxygen isotope data, for 22 mantle eclogite xenoliths from the Catoca pipe (Kasai Craton) were used to constrain their genesis and evolution. On the basis of mineralogical and major-element compositions, the Catoca eclogites can be divided into three groups: high-alumina (high-Al) (kyanite-bearing), low-magnesian (low-Mg#), and high-magnesian (high-Mg#) eclogites. The high-Al Catoca eclogites contain kyanite and corundum; high Al2O3 contents in rock-forming minerals; rare earth element (REE) patterns in garnets showing depleted LREEs, positive Eu anomalies (1.03-1.66), and near-flat HREEs; and high Sr contents in garnets and whole-rock REE compositions. All of these features point to a plagioclase-rich protolith (probably gabbro). RWR compositions (major elements, MREEs, HREEs, Li, V, Hf, Y, Zr, and Pb) and ?18O of 5.5-7.4‰ of the low-Mg# Catoca eclogites are in good agreement with the compositions of picrite basalts and average mid-ocean ridge basalt (MORB). The depleted LREEs and NMORB-normalised Nd/Yb values of 0.07-0.41 indicate that the degree of partial melting for the majority of the low-Mg# eclogites protolith was ?30%. The narrow ?18O range of 5.5-7.4‰ near the ‘gabbro-basalt’ boundary (6‰) obtained for the high-Al and low-Mg# Catoca eclogites reflects the influence of subduction-related processes. This case shows that mantle eclogites represented by two different lithologies and originating from different protoliths—plagioclase-rich precursor, presumably gabbro (for high-Al eclogites), and basalt (low-Mg# eclogites)—can provide similar and overlapping ?18O signatures on account of the influence of subduction-related processes. Chemical compositions of the high-Mg# eclogites indicate a complicated petrogenesis, and textural signatures reveal recrystallisation. The presence of Nb-rich rutile (8-12 wt% of Nb2O5) enriched with high field strength elements (HFSE) (Zr/Hf of 72.6-75.6) and multiple trace-element signatures (including RWR, NMORB-normalised Ce/Yb of 3.9-10.6 and Sr/Y of 5.8-9.6, MgO contents of 15.7-17.9 wt%, and high Ba and Sr) provide strong evidence for deep metasomatic alteration. High Cr contents in clinopyroxene (800-3740 ppm), garnet (430-1400 ppm), and accessory rutile (700-2530 ppm), together with extremely low Li contents of 1.0-2.4 ppm in clinopyroxene, may indicate hybridisation of the eclogites with peridotite. Comparison of the chemical compositions (major and trace elements) of (1) unaltered fresh cores of coarse-grained garnets from the low-Mg# eclogites, (2) secondary garnet rims (ubiquitous in the low-Mg# eclogites), (3) proto-cores in the coarse-grained garnet (high-Mg# eclogites), and (4) homogeneous recrystallised fine-grained garnets (high-Mg# eclogites) suggests that the high-Mg# eclogites formed through recrystallisation of low-Mg# eclogite in the presence of an external fluid in the mantle. Four of the five high-Mg# samples show that mantle metasomatism inside the Kasai craton mantle beneath the Catoca pipe occurred at a depth range of 145-160 km (4.5-4.8 GPa).
DS201112-0264
2011
DubitskyDenison, V.N., Mavrin, Serebryanaya, Dubitsky, Aksenenkov, Kirichenko, Kuzmin, kulnitsky, PerehoginFirst priniples, UV Raman, X-ray diffraction and TEM study of the structure and lattic dynamics of the diamond lonsdaleite system.Diamond and Related Materials, Vol. 20, 7, pp. 951-953.TechnologyLonsdaleite
DS201709-2064
2017
Dublansky, Yu.V.Tomilenko, A.A., Dublansky, Yu.V., Kuzmin, D.V., Sobolev, N.V.Isotope compositions of C and O of magmatic calcites from the Udachnaya-East pipe kimberlite, Yakutia.Doklady Earth Sciences, Vol. 475, 1, pp. 828-831.Russia, Yakutiadeposit - Udachnaya-East

Abstract: It has been demonstrated for the first time that the isotopic compositions of carbon (?13C) in magmatic calcites from the Udachnaya–East pipe kimberlite groundmass varies from–2.5 to–1.0‰ (V-PDB), while those of oxygen (?18O) range from 15.0 to 18.2‰ (V-SMOW). The obtained results imply that during the terminal late magmatic and postmagmatic stages of the kimberlite pipe formation, the carbonates in the kimberlite groundmass became successively heavier isotopically, which indicates the hybrid nature of the carbonate component of the kimberlite: it was formed with contributions from mantle and sedimentary marine sources.
DS1990-1510
1990
Dubois, J.Velde, B., Dubois, J., Touchard, G., Badri, A.Fractal analysis of fractures in rocks: the Cantor's dust methodTectonophysics, Vol. 179, pp. 345-352GlobalFractal analysis, Methodology
DS1991-1790
1991
Dubois, J.Velde, B., Dubois, J., Moore, D., Touchard, G.Fractal patterns of fractures in granitesEarth Planetary Science Letters, Vol. 104, No. 1, May pp. 25-35GlobalGranites, Fractals
DS1998-0366
1998
Dubois, J.Dubois, J., et al.Dynamic systems and dynamic classification problems in geophysicalapplicationsSpringer, 250p. $ 110.00GlobalBook - ad, Geophysics
DS2002-0625
2002
Dubois, J.O.Gvishiani, A., Dubois, J.O.Artificial intelligence and dynamic systems for geophysical applicationsSpringer, 334p.GlobalBook - Geophysics - seismology, fuzzy logic
DS200412-0756
2002
Dubois, J.O.Gvishiani, A., Dubois, J.O.Artificial intelligence and dynamic systems for geophysical applications.Springer, 334p.TechnologyBook - Geophysics - seismology,fuzzy logic
DS201509-0433
2015
Dubois, M.Thiery, V., Rolin, P., Dubois, M., Caumon, M-C.Discovery of metamorphic microdiamonds from the parautochthonous units of the Variscan French Massif Central.Gondwana Research, Vol. 28, pp. 954-960.Europe, FranceMicrodiamonds

Abstract: The Variscan French Massif Central (FMC) is classically described as a stack of nappes with increasing metamorphism from the bottom (parautochthonous unit) to the top (lower and upper gneiss units). Ultra-high pressure (UHP) metamorphism was already recognized in the uppermost units, with notably coesite-bearing rocks. We report the first finding of metamorphic microdiamonds in the parautochthonous unit, revealing that the UHP event affected the whole stack of nappes and also that the pressures reached are above what was previously expected, since the presence of diamond, according to the peak temperature estimates for this unit, indicates pressures of ca. 3 GPa (i.e. 100 km depth). At the scale of the FMC, this finding adds complexity to the established models. On a broader scale, this adds evidence of similarity between this part of the belt and other UHP Variscan terranes such as the Erzgebirge and the Bohemian Massif.
DS201603-0426
2016
Dubois, M.Thiery, V., Rolin, P., Dubois, M., Caumon, M-C., Goncalves, P.Reply: Discovery of metamorphic microdiamonds from the parautochthonous units of the Variscan French Massif Central: comment.Gondwana Research, in press available 2p.EuropeMicrodiamonds
DS1960-0442
1964
Dubois, R.L.Dubois, R.L., Carey, W.W.Magnetic Investigations of a Ring Dike, Buell Park, ArizonaGeophysics, Vol. 29, No. 4, PP. 553-564.United States, Arizona, Colorado PlateauKimberlite, Geophysics
DS1989-0372
1989
Dubois, R.L.Dubois, R.L.Archeomagnetic results from southwest United States and Mesoamerica and comparison with some other areasPhysics of the Earth and Planetary Interiors, Vol. 56, pp. 18-33Cordillera, Basin and RangeTectonics, Paleostructure
DS200812-0299
2008
Dubopvikova, Z.Dubopvikova, Z., Polekhovsky, Yu.Some special features of Kimozero kimberlites of Onega Flexure (Karelia, Russia).9IKC.com, 3p. extended abstractRussiaDeposit - Kimozero
DS202111-1759
2021
Dubovinsky, L.Britvin, S., Vlasenko, N.S., Aslandukov, A., Aslandova, A., Dubovinsky, L., Gorelova, L.A., Krzhizhanvskaya, M.G., Vereshchagin, O.S., Bocharov, V.N., Shelukina, Y.S., Lozhkin, M.S., Zaitsev, A.N., Nestola, F.Natural cubic perovskite, Ca(Ti,Si,Cr) O 3-delta, a versatile potential host rock-forming and less common elements up to Earth's mantle pressure.American Mineralogist, doi:10.2138/am-2022-8186 in pressMantleperovskite

Abstract: Perovskite, CaTiO3, originally described as a cubic mineral, is known to have a distorted (orthorhombic) crystal structure. We herein report on the discovery of natural cubic perovskite. This was identified in gehlenite rocks occurring in a pyrometamorphic complex of the Hatrurim Formation (the Mottled Zone), in the vicinity of the Dead Sea, Negev Desert, Israel. The mineral is associated with native ?-(Fe,Ni) metal, schreibersite (Fe3P) and Si-rich fluorapatite. The crystals of this perovskite reach 50 ?m in size and contain many micron sized inclusions of melilite glass. The mineral contains significant amounts of Si substituting for Ti (up to 9.6 wt.% SiO2) corresponding to 21 mol.% of the davemaoite component (cubic perovskite-type CaSiO3), in addition to up to 6.6 wt.% Cr2O3. Incorporation of trivalent elements results in the occurrence of oxygen vacancies in the crystal structure; this being the first example of natural oxygen-vacant ABO3 perovskite with the chemical formula Ca(Ti,Si,Cr)O3-? (? ~ 0.1). Stabilization of cubic symmetry (space group Pm?3m) is achieved via the mechanism not reported so far for CaTiO3, namely displacement of an oxygen atom from its ideal structural position (site splitting). The mineral is stable at atmospheric pressure to 1250±50 °C; above this temperature its crystals fuse with the embedded melilite glass, yielding a mixture of titanite and anorthite upon melt solidification. The mineral is stable upon compression to at least 50 GPa. The a lattice parameter exhibits continuous contraction from 3.808(1) Ĺ at atmospheric pressure to 3.551(6) Ĺ at 50 GPa. The second-order truncation of the Birch-Murnaghan equation of state gives the initial volume V0 equal to 55.5(2) Ĺ3 and room temperature isothermal bulk modulus K0 of 153(11) GPa. The discovery of oxygen-deficient single perovskite suggests previously unaccounted ways for incorporation of almost any element into the perovskite framework up to pressures corresponding to those of the Earth’s mantle.
DS1990-0430
1990
DuBray, E.A.DuBray, E.A., Quick, J.E., Sekner, G.I., Pallister, J.S.SAVEWARE I: a dozen programs designed to read DATASAVE files, perform various petrologic calculations and produce printed and graphical dataanalysisUnited States Geological Survey (USGS) Open file, No. 90-616-A, B, C $ 4.50, $6.00, $12.00GlobalComputer, Program -SAVEWAREI
DS1995-0449
1995
DuBray, E.A.DuBray, E.A.Preliminary compilation of descriptive geoenvironmental mineral depositmodelsUnited States Geological Survey (USGS) Open file, No. 95-831, 270p. $ 50.00United StatesEnvironment, Models -mineral deposits
DS1995-0450
1995
DuBray, E.A.DuBray, E.A., et al.Compositional characteristics of middle to upper Tertiary volcanic rocks Of the Bolivian AltiplanoUnited States Geological Survey (USGS) Bulletin, No. B2119, 30p. $ 2.75BoliviaGeochemistry, Volcanics
DS1992-0398
1992
Dubray, J.J.Dubray, J.J., Pantano, C.G., Yarborogh, W.A.Graphite as a substrate for diamond growthJournal of Applied Physics, Vol. 72, No. 7, October 1, pp. 3136-3142. # JT007GlobalDiamond genesis, Graphite
DS200412-0488
2004
Dubroninsky, L.Dubroninsky, L., et al.Reaction of iron and silica at core mantle boundary conditions.Physics of the Earth and Planetary Interiors, Vol. 146, 1-2, pp. 243-247.MantleGeochemistry
DS2003-0354
2003
Dubrovinskaia, N.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
DS201612-2324
2014
Dubrovinskaia, N.Nemeth, P., Garvies, L.A.J., Aoki, T., Dubrovinskaia, N., Dubrovinsky, L.Londaleite is faulted and twinned cubic diamond and does not exist as a discrete material.Nature Communications, Nov. 10p. * note dateTechnologyLonsdaleite

Abstract: Lonsdaleite, also called hexagonal diamond, has been widely used as a marker of asteroidal impacts. It is thought to play a central role during the graphite-to-diamond transformation, and calculations suggest that it possesses mechanical properties superior to diamond. However, despite extensive efforts, lonsdaleite has never been produced or described as a separate, pure material. Here we show that defects in cubic diamond provide an explanation for the characteristic d-spacings and reflections reported for lonsdaleite. Ultrahigh-resolution electron microscope images demonstrate that samples displaying features attributed to lonsdaleite consist of cubic diamond dominated by extensive {113} twins and {111} stacking faults. These defects give rise to nanometre-scale structural complexity. Our findings question the existence of lonsdaleite and point to the need for re-evaluating the interpretations of many lonsdaleite-related fundamental and applied studies.
DS201112-0729
2011
Dubrovinskaia, N.A.Naygina, O., Dubrovinsky, L.S., McCammon, C.A., Kurnosov, A., Kantor, I.Y., Prakapenka, V.B., Dubrovinskaia, N.A.X-ray diffraction and Mossbauer spectroscopy study of fcc iron hydride FeH at high pressures and implications for the composition of the Earth's core.Earth and Planetary Science Letters, Vol. 307, 3-4, pp. 409-414.MantleHydrogen budget
DS201212-0699
2012
Dubrovinskaia, N.A.Spivak, A.V., Litvin, Yu.A., Ovsyannikov, S.V., Dubrovinskaia, N.A., Dubrovinsky, L.S.Stability and breakdown of Ca13CO3 melt associated with formation of 13 C diamond in static high pressure experiments up to 43 Gpa and 3900K.Journal of Solid State Chemistry, Vol. 191, pp. 102-106.TechnologyDiamond - genesis
DS201412-0866
2013
Dubrovinskaia, N.A.Solopova, N.A., Litvin, Yu.A., Spivak, A.V., Dubrovinskaia, N.A., Dubrovinsky, L.S., Urusov, V.S.The phase diagram of Na carbonate, an alkaline component of the growth medium of ultradeep diamonds.Doklady Earth Sciences, Vol. 451, 1, pp. 1106-1109.TechnologyUHP
DS201112-0993
2011
Dubrovinskii, L.S.Spivak, A.V., Dubrovinskii, L.S., Litvin, Yu.A.Congruent melting of calcium carbonate in a static experiment at 3500 K and 10-22 GPa: its role in the genesis of untradeep diamonds.Doklady Earth Sciences, Vol. 439, 2, pp.1171-1174.TechnologyDiamond genesis
DS201112-0992
2011
Dubrovinskii, Yu.Spivak, A., Dubrovinskii, Yu., LitvinCongruent melting of calcium carbonate in a static experiment at 3500 K and 10-22 GPa: its role in the genesis of ultradeep diamonds.Doklady Earth Sciences, Vol. 439, 2, pp. 1171-1174.MantleUHP diamond genesis
DS200812-0728
2008
DubrovinskyMcCammon, C., Kantor, I., Narygina, O., Roquette, J., Ponkratz, Sergieev, Mezouar, Prakapenka, DubrovinskyStable intermediate spin ferrous iron in lower mantle perovskite.Nature Geoscience, Vol. 1, 10, pp. 684-687.MantlePerovskite
DS201012-0213
2010
DubrovinskyFrost, D.F., Asahara, Y., Rubie, D.C., Miyajima, N., Dubrovinsky, Holzapfel, Ohtani, Miyahara, SakaiPartitioning of oxygen between the Earth's mantle and core.Journal of Geophysical Research, Vol. 115, B2 , B02202.MantleChemistry
DS201112-0698
2011
DubrovinskyMookerjee, M., Nakajima, Y., Steinle-Neumann, G., Glazyrin, K., Wu, X., Dubrovinsky, McCammon, ChumakovHigh pressure behaviour of iron carbide (Fe[7]C[3j] at inner core conditions.Journal of Geophysical Research, Vol. 116, B4, B04201.MantleHP core
DS201412-0566
2013
DubrovinskyMcCammon, C., Glazyrin, K., Kantor, A., Kantor, I., Kupenko, I., Narygina, O., Potapin, V., Vasily, P., Sinmyo, C., Chumakov, Ruffer, Sergueev, Smirnov, DubrovinskyIron spin state in silicate perovskite at conditions of Earth's deep interior.International Journal of High Pressure Research, Vol. 33, 3, pp. 663-672.MantlePerovskite
DS201907-1555
2019
DubrovinskyKupenko, G.A., Vasilukov, D.M., McCammon, C., Charleton, S., Cerantola, V., Kantor, I., Chumakov, A.I.., Ruffer, R., Dubrovinsky, L, Sanchez-Valle, C.Magnetism in cold subducting slabs at mantle transition zone depths.Nature, Vol. 570, 7759, p. 102.Mantlesubduction

Abstract: The Earth’s crust-mantle boundary, the Mohorovi?i? discontinuity, has been traditionally considered to be the interface between the magnetic crust and the non-magnetic mantle1. However, this assumption has been questioned by geophysical observations2,3 and by the identification of magnetic remanence in mantle xenoliths4, which suggest mantle magnetic sources. Owing to their high critical temperatures, iron oxides are the only potential sources of magnetic anomalies at mantle depths5. Haematite (?-Fe2O3) is the dominant iron oxide in subducted lithologies at depths of 300 to 600 kilometres, delineated by the thermal decomposition of magnetite and the crystallization of a high-pressure magnetite phase deeper than about 600 kilometres6. The lack of data on the magnetic properties of haematite at relevant pressure-temperature conditions, however, hinders the identification of magnetic boundaries within the mantle and their contribution to observed magnetic anomalies. Here we apply synchrotron Mössbauer source spectroscopy in laser-heated diamond anvil cells to investigate the magnetic transitions and critical temperatures in Fe2O3 polymorphs7 at pressures and temperatures of up to 90 gigapascals and 1,300 kelvin, respectively. Our results show that haematite remains magnetic at the depth of the transition zone in the Earth’s mantle in cold or very cold subduction geotherms, forming a frame of deep magnetized rocks in the West Pacific region. The deep magnetic sources spatially correlate with preferred paths of the Earth’s virtual geomagnetic poles during reversals8 that might not reflect the geometry of the transitional field. Rather, the paths might be an artefact caused by magnetized haematite-bearing rocks in cold subducting slabs at mid-transition zone depths. Such deep sources should be taken into account when carrying out inversions of the Earth’s geomagnetic data9, and especially in studies of planetary bodies that no longer have a dynamo10, such as Mars.
DS1998-0367
1998
Dubrovinsky, L.Dubrovinsky, L., Saxena, S.K., Johansson, B.Theoretical study of the stability of MgSiO3 perovskite in the deepmantle.Geophs. Res. Lett., Vol. 25, No. 23, Dec. 1, pp. 4253-56.MantlePerovskite
DS2001-0272
2001
Dubrovinsky, L.Dubrovinsky, L., et al.Chemical interaction of iron and Al2O3 as a source of heterogeneity at the Earth's core - mantle boundary.Nature, No. 8636, Aug. 2, pp. 527-9.MantleGeochemistry, Core - boundary
DS2003-0354
2003
Dubrovinsky, L.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
DS200812-0587
2008
Dubrovinsky, L.Kopylova, M., Navon, O., Dubrovinsky, L., Khachatryan, G.Mineralogy and natural diamond forming fluids.Goldschmidt Conference 2008, Abstract p.A490.Africa, Democratic Republic of CongoDiamond mineralogy
DS201012-0402
2010
Dubrovinsky, L.Kopylova, M., Navon, O., Dubrovinsky, L., Khachatryan, G.Carbonatitic mineralogy of natural diamond forming fluids.Earth and Planetary Science Letters, Vol. 291, 1-4, pp. 126-137.MantleCarbonatite
DS201012-0728
2010
Dubrovinsky, L.Smith, E., Kopylova, M., Dubrovinsky, L., Tomlinson, E.X-ray diffraction study of the mineral and fluid inclusions in fibrous diamond.38th. Geoscience Forum Northwest Territories, Abstract pp.124-125.Canada, Northwest Territories, Ontario, Africa, Democratic Republic of CongoMineral inclusions - Panda, Jericho
DS201112-0979
2011
Dubrovinsky, L.Smith, E.M., Kopylova, M.G., Dubrovinsky, L., Navon, O., Ryder, J.E., Tomlinson, L.Transmission X-ray diffraction as a new tool for diamond fluid inclusion studies.Mineralogical Magazine, Vol. 75, 5, Oct. pp. 2657-2675.Africa, Democratic Republic of Congo, Canada, Ontario, Wawa, Northwest Territories, NunavutDeposit - Mbuji-Mayi, Wawa, Panda, Jericho
DS201312-0247
2013
Dubrovinsky, L.Ernok, A., Boffa Ballaran, T., Caracas, R., Miyajima, N., Bykova, E., Prakapenka, V., Liermann, H-P., Dubrovinsky, L.Pressure induced phase transitions in coesite.Goldschmidt 2013, AbstractTechnologyCarbonatite
DS201312-0720
2014
Dubrovinsky, L.Prescher, C., Weigel, C., McCammon, C., Narygina, O., Potapkin, V., Kupenko, I., Sinmyo, R., Chumakov, A.I., Dubrovinsky, L.Iron spin state in silicate glass at high pressure: implications for melts in the Earth's lower mantle.Earth and Planetary Science Letters, Vol. 385, pp. 130-136.MantleUHP
DS201412-0297
2014
Dubrovinsky, L.Glazyrin, K., Boffa Ballaran, T., Frost, D.J., McCammon, C., Kantor, A., Merlini, M., Hanfland, M., Dubrovinsky, L.Magnesium silicate perovskite and effect of iron oxidation state on its bulk sound velocity at the conditions of the lower mantle.Earth and Planetary Science Letters, Vol. 393, pp. 182-186.MantlePerovskite
DS201412-0515
2014
Dubrovinsky, L.Litvin, Yu., Spivak, A., Dubrovinsky, L.Evolution of the Earth's lower-mantle matter: stishovite paradox and origin of "super-deep" diamonds ( experiments at 24 Gpa)European High Pressure Research Group, Lyon France June 22-27., 1p. Abstract availableMantleStishovite
DS201412-0834
2014
Dubrovinsky, L.Sinmyo, R., Pesce, G., Greenberg, E., McCammon, C., Dubrovinsky, L.Lower mantle electrical conductivity based on measurements of Al, Fe-bearing perovskite under lower mantle conditions.Earth and Planetary Science Letters, Vol. 393, pp. 165-172.MantleGeophysics
DS201504-0213
2015
Dubrovinsky, L.Prescher, C., Dubrovinsky, L., Bykova, E., Kupenko, I., Glazyrin, K.High Poisson's ration of Earth's inner core explained by carbon alloying.Nature Geoscience, Vol. 8, 3, pp. 220-223.MantleCore, carbon
DS201509-0429
2015
Dubrovinsky, L.Spivak, A., Solopova, N., Dubrovinsky, L., Litvin, Y.Melting relations of multicompnent carbonate MgCO3-FeCO3-CaCO3-Na2CO3 system at 12-26 Gpa: application to deeper mantle diamond formation.Physics and Chemistry of Minerals, DOI 10.1007/ s00269-015-0765-6MantleMelting

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

Abstract: Carbonatic components of parental melts of the deeper mantle diamonds are inferred from their primary inclusions of (Mg, Fe, Ca, Na)-carbonate minerals trapped at PT conditions of the Earth’s transition zone and lower mantle. PT phase diagrams of MgCO3-FeCO3-CaCO3-Na2CO3 system and its ternary MgCO3-FeCO3-Na2CO3 boundary join were studied at pressures between 12 and 24 GPa and high temperatures. Experimental data point to eutectic solidus phase relations and indicate liquidus boundaries for completely miscible (Mg, Fe, Ca, Na)- and (Mg, Fe, Ca)-carbonate melts. PT fields for partial carbonate melts associated with (Mg, Fe)-, (Ca, Fe, Na)-, and (Na2Ca, Na2Fe)-carbonate solid solution phases are determined. Effective nucleation and mass crystallization of deeper mantle diamonds are realized in multicomponent (Mg, Fe, Ca, Na)-carbonatite-carbon melts at 18 and 26 GPa. The multicomponent carbonate systems were melted at temperatures that are lower than the geothermal ones. This gives an evidence for generation of diamond-parental carbonatite melts and formation of diamonds at the PT conditions of transition zone and lower mantle.
DS201612-2324
2014
Dubrovinsky, L.Nemeth, P., Garvies, L.A.J., Aoki, T., Dubrovinskaia, N., Dubrovinsky, L.Londaleite is faulted and twinned cubic diamond and does not exist as a discrete material.Nature Communications, Nov. 10p. * note dateTechnologyLonsdaleite

Abstract: Lonsdaleite, also called hexagonal diamond, has been widely used as a marker of asteroidal impacts. It is thought to play a central role during the graphite-to-diamond transformation, and calculations suggest that it possesses mechanical properties superior to diamond. However, despite extensive efforts, lonsdaleite has never been produced or described as a separate, pure material. Here we show that defects in cubic diamond provide an explanation for the characteristic d-spacings and reflections reported for lonsdaleite. Ultrahigh-resolution electron microscope images demonstrate that samples displaying features attributed to lonsdaleite consist of cubic diamond dominated by extensive {113} twins and {111} stacking faults. These defects give rise to nanometre-scale structural complexity. Our findings question the existence of lonsdaleite and point to the need for re-evaluating the interpretations of many lonsdaleite-related fundamental and applied studies.
DS201707-1367
2017
Dubrovinsky, L.Sinmyo, R., McCammon, C., Dubrovinsky, L.The spin state of Fe3+ in lower mantle bridgmanite.American Mineralogist, Vol. 102, pp. 1263-1269.Mantlebridgmanite

Abstract: Iron- and aluminum-bearing MgSiO3 bridgmanite is the most abundant mineral in the Earth’s interior; hence its crystal chemistry is fundamental to expanding our knowledge of the deep Earth and its evolution. In this study, the valence and spin state of iron in well-characterized Al-free Fe3+-rich bridgmanite were investigated by means of Mössbauer spectroscopy to understand the effect of ferric iron on the spin state. We found that a minor amount of Fe3+ is in the low-spin state above 36 GPa and that its proportion does not increase substantially with pressure up to 83 GPa. This observation is consistent with recent experimental studies that used Mössbauer and X-ray emission spectroscopy. In the Earth’s deep lower mantle, Fe3+ spin crossover may take place at depths below 900 and 1200 km in pyrolite and MORB, respectively. However, the effect of spin crossover on physical properties may be small due to the limited amount of Fe3+ in the low-spin state.
DS201709-2014
2017
Dubrovinsky, L.Kiseeva, E.S., Vasiukov, D.M., Wood, B.J., McCammon, C., Stachel, T., Chumakov, A., Dubrovinsky, L.Oxidation state of majoritic garnet inclusions in diamond.Goldschmidt Conference, abstract 1p.Africa, South Africadeposit, Jagersfontein

Abstract: Diamond inclusions are the only samples from the mantle transition zone (410-660 km) and the lower mantle. Majoritic garnet is a rare inclusion, limited to pressures of ~8-20 Gpa with Si content being indicative of depth of re-equilibration. These garnet inclusions can therefore provide information on properties of the transition zone such as oxidation state. In this study, we used Synchrotron Mössbauer Source (SMS) to determine the ferric-ferrous ratios of 13 small (30 to 100 micrometers diameter) majoritic inclusions in diamonds from Jagersfontein. The studied inclusions have pyroxenitic affinities [1], with compositions intermediate between typical peridotite and eclogite. They contain 4.62-11.2 wt% CaO, 0.03-0.34 wt% Cr2O3 and Mg# of 0.65-0.81. Minimum pressures for their equilibration using Beyer and Frost [2] barometer are between 8 and 18 GPa with at least 4 of these inclusions being formed in the transition zone. The Fe3+/Fetotal ratios in the garnets increase from 0.08±0.01 to 0.30±0.03 with increasing pressure. These values define a clear extension of the trend apparent in the data from peridotite xenoliths crystallised at lower pressures. Thermodynamic calculations suggest that these high ferric contents correspond to oxygen fugacities above the FeFeO (IW) buffer, which means that the high Fe3+ contents were not generated by disproportionation of Fe2+ to Fe3+ and Fe0 . It is more likely that carbonate was the oxidising agent responsible for generating the high Fe3+ of these garnets.
DS201902-0285
2018
Dubrovinsky, L.Kiseeva, E.S., Vasiukov, D.M., Wood, B.J., McCammon, C., Stachel, T., Bykov, M., Bykova, E., Chumakov, A., Cerantola, V., Harris, J.W., Dubrovinsky, L.Oxidized iron in garnets from the mantle transition zone.Nature Geoscience, Vol. 11, pp. 144-147. Africa, South Africadeposit - Jagersfontein

Abstract: The oxidation state of iron in Earth’s mantle is well known to depths of approximately 200?km, but has not been characterized in samples from the lowermost upper mantle (200-410?km depth) or the transition zone (410-660?km depth). Natural samples from the deep (>200?km) mantle are extremely rare, and are usually only found as inclusions in diamonds. Here we use synchrotron Mössbauer source spectroscopy complemented by single-crystal X-ray diffraction to measure the oxidation state of Fe in inclusions of ultra-high pressure majoritic garnet in diamond. The garnets show a pronounced increase in oxidation state with depth, with Fe3+/(Fe3++ Fe2+) increasing from 0.08 at approximately 240?km depth to 0.30 at approximately 500?km depth. The latter majorites, which come from pyroxenitic bulk compositions, are twice as rich in Fe3+ as the most oxidized garnets from the shallow mantle. Corresponding oxygen fugacities are above the upper stability limit of Fe metal. This implies that the increase in oxidation state is unconnected to disproportionation of Fe2+ to Fe3+ plus Fe0. Instead, the Fe3+ increase with depth is consistent with the hypothesis that carbonated fluids or melts are the oxidizing agents responsible for the high Fe3+ contents of the inclusions.
DS202009-1635
2020
Dubrovinsky, L.Koemets, I., Satta, N., Marquardt, H., Kiseeva, E.S., Kurnosov, A., Stachel, T., Harris, J.W., Dubrovinsky, L.Elastic properties of majorite garnet inclusions in diamonds and the seismic signature of pyroxenites in the Earth's upper mantle.American Mineralogist, Vol. 105, pp. 984-991. pdfMantlediamond inclusions

Abstract: Majoritic garnet has been predicted to be a major component of peridotite and eclogite in Earth's deep upper mantle (>250 km) and transition zone. The investigation of mineral inclusions in diamond confirms this prediction, but there is reported evidence of other majorite-bearing lithologies, intermediate between peridotitic and eclogitic, present in the mantle transition zone. If these lithologies are derived from olivine-free pyroxenites, then at mantle transition zone pressures majorite may form monomineralic or almost monomineralic garnetite layers. Since majoritic garnet is presumably the seismically fastest major phase in the lowermost upper mantle, the existence of such majorite layers might produce a detectable seismic signature. However, a test of this hypothesis is hampered by the absence of sound wave velocity measurements of majoritic garnets with relevant chemical compositions, since previous measurements have been mostly limited to synthetic majorite samples with relatively simple compositions. In an attempt to evaluate the seismic signature of a pyroxenitic garnet layer, we measured the sound wave velocities of three natural majoritic garnet inclusions in diamond by Brillouin spectroscopy at ambient conditions. The chosen natural garnets derive from depths between 220 and 470 km and are plausible candidates to have formed at the interface between peridotite and carbonated eclogite. They contain elevated amounts (12-30%) of ferric iron, possibly produced during redox reactions that form diamond from carbonate. Based on our data, we model the velocity and seismic impedance contrasts between a possible pyroxenitic garnet layer and the surrounding peridotitic mantle. For a mineral assemblage that would be stable at a depth of 350 km, the median formation depth of our samples, we found velocities in pyroxenite at ambient conditions to be higher by 1.9(6)% for shear waves and 3.3(5)% for compressional waves compared to peridotite (numbers in parentheses refer to uncertainties in the last given digit), and by 1.3(13)% for shear waves and 2.4(10)% for compressional waves compared to eclogite. As a result of increased density in the pyroxenitic layer, expected seismic impedance contrasts across the interface between the monomineralic majorite layer and the adjacent rocks are about 5-6% at the majorite-eclogite-interface and 10-12% at the majoriteperidotite-boundary. Given a large enough thickness of the garnetite layer, velocity and impedance differences of this magnitude could become seismologically detectable.
DS202109-1454
2021
Dubrovinsky, L.Bindi, L., Sinmyo, R., Bykova, E., Ovsyannikov, S.V., McCammon, C., Kupenko, I., Ismailova, L., Dubrovinsky, L., Xie, X.Discovery of Elgoresyite ( Mg,FE)5Si2O9: implications for novel iron magnesium silicates in rocky planetery interiors. Mentions Earth's magmatismACS Earth Space Chemistry, Vol. 5, pp. 2124-2130.Mantlebridgmanite

Abstract: As the most abundant material of rocky planets, high-pressure polymorphs of iron- and aluminum-bearing magnesium silicates have long been sought by both observations and experiments. Meanwhile, it was recently revealed that iron oxides form (FeO)m(Fe2O3)n homologous series above ?10 GPa according to laboratory high-pressure experiments. Here, we report a new high-pressure iron-magnesium silicate, recently approved by the International Mineralogical Association as a new mineral (No. 2020-086) and named elgoresyite, in a shock-induced melt vein of the Suizhou L6 chondrite with a chemistry of (Mg,Fe)5Si2O9. The crystal structure of this new silicate is the same as the iron oxide Fe7O9, strongly suggesting that silicates also form ((Mg,Fe)O)m + n(SiO2)n series that are isostructural to iron oxides via (Mg2+,Fe2+) + Si4+ = 2Fe3+ substitution. To test this hypothesis, the phase relationships of the silicates and iron oxides should be further investigated at higher temperature conditions. Newly found iron-magnesium silicate is a potential constituent mineral in rocky planets with relatively high MgO + FeO content.
DS1998-1288
1998
Dubrovinsky, L.SSaxena, S.K., Dubrovinsky, L.S, Lazor, P.Mineralogy of the core and lower mantleIma 17th. Abstract Vol., p. A 42, abstractMantleMineralogy
DS1996-1256
1996
Dubrovinsky, L.S.Saxena, S.K., Dubrovinsky, L.S., Hu, J.Stability of perovskite in the earth's mantleScience, Vol. 274, No. 5291, Nov. 22, pp. 1357-9.MantlePerovskite
DS2000-0861
2000
Dubrovinsky, L.S.Saxena, S.K., Lazor, P., Dubrovinsky, L.S.A model of Earth's deep interior based on mineralogical dataMin. Petrol., Vol. 69, No. 1-2, pp. 1-10.MantleMineralogy, Model - mineralogy
DS2003-0379
2003
Dubrovinsky, L.S.El Goresy, A., Dubrovinsky, L.S., Gillet, P., Mostefaoul, S., Graup, G.A new natural super hard transparent polymorph of carbon from the Popigai impactComptes Rendus Geosciences, IN FRENCH, Vol. 335, 12, Oct. pp. 889-898.RussiaBlank
DS200412-0515
2003
Dubrovinsky, L.S.El Goresy, A., Dubrovinsky, L.S., Gillet, P., Mostefaoul, S., Graup, G., Drakopoulos, M., Simionovici, A.S.A new natural super hard transparent polymorph of carbon from the Popigai impact crater, Russia.Comptes Rendus Geoscience, Vol. 335, 12, Oct. pp. 889-898.RussiaLonsdaleite, graphite, mineralogy
DS200912-0366
2008
Dubrovinsky, L.S.Keepler, H., Dubrovinsky, L.S., Narygina, O., Kantor, I.Optical absorption and radioactive thermal conductivity silicate perovskite to 125 Gpa at high pressures, silicate perovskite, abundant in Earth's mantle....Science, Vol. 322, 5907 Dec. 5, pp. 1529-1531.MantleGeothermometry Radioactive heat important in deep Earth
DS201112-0729
2011
Dubrovinsky, L.S.Naygina, O., Dubrovinsky, L.S., McCammon, C.A., Kurnosov, A., Kantor, I.Y., Prakapenka, V.B., Dubrovinskaia, N.A.X-ray diffraction and Mossbauer spectroscopy study of fcc iron hydride FeH at high pressures and implications for the composition of the Earth's core.Earth and Planetary Science Letters, Vol. 307, 3-4, pp. 409-414.MantleHydrogen budget
DS201112-0994
2011
Dubrovinsky, L.S.Spivak, A.V., Litvin, Yu.A., Dubrovinsky, L.S.Stability and breakdown of Ca13 CO3 melt combined with formation of 13 C diamond in static experiments up to 80 GPa and 4000K.Goldschmidt Conference 2011, abstract p.1923.TechnologyNatural super deep diamonds origin
DS201212-0699
2012
Dubrovinsky, L.S.Spivak, A.V., Litvin, Yu.A., Ovsyannikov, S.V., Dubrovinskaia, N.A., Dubrovinsky, L.S.Stability and breakdown of Ca13CO3 melt associated with formation of 13 C diamond in static high pressure experiments up to 43 Gpa and 3900K.Journal of Solid State Chemistry, Vol. 191, pp. 102-106.TechnologyDiamond - genesis
DS201412-0222
2003
Dubrovinsky, L.S.El Goresy, A., Dubrovinsky, L.S., Gillet, P., Mostefaoui, S., Graup, G., Drakopoulos, M., Simionovici, A.S., Swamy, V., Masaitis, V.L.A new natural, super-hard, transparent polymorph of carbon from the Popigai impact crater, Russia.Comptes Rendus Geoscience, Vol. 335, pp. 889-898.Russia, YakutiaMeteorite
DS201412-0711
2014
Dubrovinsky, L.S.Prescher, C., Langenhorst, F., Dubrovinsky, L.S., Prakapenka, V.B., Miyajima, N.The effect of Fe spin crossovers on its partitioning behavior and oxidation state in a pyrolitic Earth's lower mantle system.Earth and Planetary Science Letters, Vol. 399, pp. 86-91.MantleOxidation
DS201412-0866
2013
Dubrovinsky, L.S.Solopova, N.A., Litvin, Yu.A., Spivak, A.V., Dubrovinskaia, N.A., Dubrovinsky, L.S., Urusov, V.S.The phase diagram of Na carbonate, an alkaline component of the growth medium of ultradeep diamonds.Doklady Earth Sciences, Vol. 451, 1, pp. 1106-1109.TechnologyUHP
DS201511-1882
2015
Dubrovinsky, L.S.Spivak, A.V., Solopova, N.A., Dubrovinsky, L.S., Litvin, Yu.A.The system MgCO3-FeCO3-CaCO3-Na2CO3 at 12-23 Gpa: phase relations and significance for the genesis of ultradeep diamonds.Doklady Earth Sciences, Vol. 464, 1, pp. 946-950.MantleDiamond genesis

Abstract: Physical-chemical experimental studies at 12-23 GPa of phase relationships within four-members carbonate system MgCO3-FeCO3-CaCO3-Na2CO3 and its marginal system MgCO3-FeCO3-Na2CO3 were carried out. The systems are quite representative for a set of carbonate phases from inclusions in diamonds within transitional zone and lower mantle. PT-phase diagrams of multicomponent carbonate systems are suggested. PT parameters of boundaries of their eutectic melting (solidus), complete melting (liquids) are established. These boundaries define area of partial melting. Carbonate melts are stable, completely mixable, and effective solvents of elemental carbon thus defining the possibility of ultra-deep diamonds generation.
DS201511-1883
2015
Dubrovinsky, L.S.Spivak, A.V., Solopova, N.A., Dubrovinsky, L.S., Litvin, Yu.A.Melting relations of multicomponent carbonate MgCOs-FeCO3-CaCO3-Na2COs system at 12-26 Gpa: application to deeper mantle diamond formation.Physics and chemistry of Minerals, Vol. 42, 10, pp. 817-824.TechnologyDiamond genesis - experimental
DS201706-1091
2017
Dubrovinsky, L.S.Litvin, Y.A., Spivak, A.V., Simonova, D.A., Dubrovinsky, L.S.The stishovite paradox in the evolution of lower mantle magmas and diamond forming melts ( experiment at 24 and 26 Gpa)Doklady Earth Sciences, Vol. 473, pp. 444-448.Technologydiamond - ultradeep

Abstract: Experimental studies of phase relations in the oxide-silicate system MgO-FeO-SiO2 at 24 GPa show that the peritectic reaction of bridgmanite controls the formation of stishovite as a primary in situ mineral of the lower mantle and as an effect of the stishovite paradox. The stishovite paradox is registered in the diamond-forming system MgO-FeO-SiO2-(Mg-Fe-Ca-Na carbonate)-carbon in experiments at 26 GPa as well. The physicochemical mechanisms of the ultrabasic-basic evolution of deep magmas and diamondforming media, as well as their role in the origin of the lower mantle minerals and genesis of ultradeep diamonds, are studied.
DS201709-2057
2017
Dubrovinsky, L.S.Spivak, A.V., Litvin, Y.A., Dubrovinsky, L.S.Evolution of the lower mantle magma and diamond forming melts ( Experiment at 24-26 Gpa).Goldschmidt Conference, abstract 1p.Technologypetrology

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

Abstract: The peritectic reaction of ringwoodite (Mg,Fe)2SiO4 and silicate-carbonate melt with formation of magnesiowustite (Fe,Mg)O, stishovite SiO2, and Mg, Na, Ca, K-carbonates is revealed by experimental study at 20 GPa of phase relations in the multicomponent diamond-forming MgO-FeO-SiO2-Na2CO3-CaCO3-K2CO3 system of the Earth mantle transition zone. An interaction of CaCO3 and SiO2 with a formation of Ca-perovskite CaSiO3 is also detected. It is shown that the peritectic reaction of ringwoodite and melt with the formation of stishovite controls physicochemically the fractional ultrabasic-basic evolution of both magmatic and diamond-forming systems of deep horizons of the transition zone up to its boundary with the Earth lower mantle.
DS202009-1632
2020
Dubrovinsky, L.S.Iskrina, A., Spivak, A.V., Bobrov, A.V., Eremin, N.N., Marchenko, E.I., Dubrovinsky, L.S.Synthesis and crystal structures of new high-pressure phases CaAl2O4 and Ca2Al6O11.Lithos, Vol. 374-375, 6p. PdfMantlegarnet

Abstract: The phases of CaAl2O4 and Ca2Al6O11 were synthesized at 15 GPa and 1600 °C. Microprobe data gave formulae Ca1.003Al1.998O4 and Ca2.05Al5.97O11, on the basis of 4 and 11 oxygen atoms. The crystal structures have been refined by single-crystal X-ray diffraction. Orthorhombic unitcell parameters for CaAl2O4 are a = 8.8569(10) Ĺ; b = 2.8561(4) Ĺ; c = 10.2521(11) Ĺ; V = 259.34(5) Ĺ3; Z = 8 (space group Pnma). The Ca2Al6O11 phase was obtained for the first time. It crystallizes with a space group P42/mnm and has lattice parameters a = b = 11.1675(4) Ĺ; c = 2.83180(10) Ĺ; V = 353.16(2) Ĺ3; Z = 2. A Raman spectrum was obtained for a new phase for the first time. Our results suggest that both studied phases are stable under the condition of the transition zone and can be considered as potential aluminum concentrators in the Earth's deep geospheres.
DS200912-0404
2009
Dubrovisnky, L.Kopylova, M.G., Navon, O., Dubrovisnky, L.Carbonatitic affinity of natural diamond forming fluids.37th. Annual Yellowknife Geoscience Forum, Abstracts p. 37.TechnologyDiamond morphology - cubic fibrous
DS1988-0180
1988
Dubrovskiy, V.V.Dubrovskiy, V.V., Klimenko, V.M., Ovichinnikov, L.N. Editor.Comparative gaseous characteristics of diatremes in diamond potential and rare earth provinces.(Russian)Theory Practice of Geoch. Explor.Modern Conditions, IV All Union Meet, Vol. 7, p. 66. (Russian)RussiaDiatremes, Gases
DS1994-0461
1994
Dubrule, O.Dubrule, O.Estimating or choosing a geostatistical modelGeostatistics for the Next Century, pp. 3-14GlobalGeostatistics, Models
DS1995-0913
1995
DubucKanesewich, E.R., Burianyk, Dubuc, Lemieux, KalantzisThree dimensional seismic reflection studies of the Alberta basementCanadian Journal of Exploration Geophysics, Vol. 31, No. 1-2, pp. 1-10.AlbertaGeophysics - seismics, Tectonics
DS2000-0246
2000
Dubuffet, F.Dubuffet, F., Rabinowicz, M., Monnereau, M.Multiple scales in mantle convectionEarth and Planetary Science Letters, Vol. 178, No. 3-4, May 30, pp. 351-66.MantleSubduction, Convection
DS201012-0745
2010
Dubuffet, F.Sramek, O., Ricard, Y., Dubuffet, F.A multiphase model of core formation.Geophysical Journal International, Vol. 181, 1, pp. 198-220.MantleMagmatism
DS200512-0385
2005
DuceaHacker, B., Luffi, P., Lutkov, V., Minaev, Metcalfe, Ratschbacher, Plank, Ducea, Patinodouce, McWiliamsNear ultrahigh pressure processing of continental crust: Miocene crustal xenoliths from the Pamir.Journal of Petrology, Vol. 46, 8, pp. 1661-1687.Asia, PamirXenoliths
DS200512-0910
2005
Ducea, E.A.Root, D.B., Hacker, B.R., Gans, P.B., Ducea, E.A., Eide, J.L.Discrete ultrahigh prssure domains in the Western Gneiss region, Norway: implications for formation and exhumation.Journal of Metamorphic Geology, Vol. 23, 1, pp. 45-61.Europe, NorwayUHP
DS1998-0368
1998
Ducea, M.Ducea, M., Saleeby, J.Crustal recycling beneath continental arcs: silica rich glass inclusions inEarth and Planetary Science Letters, Vol. 156, No. 1-2, Mar. 15, pp. 101-116.California, Sierra NevadaXenoliths, Subduction
DS2001-0273
2001
Ducea, M.Ducea, M.The California Arc: thick granitic batholiths, eclogitic residues, lithospheric scale thrusting...Gsa Today, Nov. pp. 4-10.CaliforniaMagmatism - magmatic flare ups, Hot spots, tectonics
DS200712-0278
2007
Ducea, M.Ducea, M.Searching for the perfectly removable ultrabasic and dense lower crust.Plates, Plumes, and Paradigms, 1p. abstract p. A241.MantleRecycling
DS1994-0462
1994
Ducea, M.N.Ducea, M.N., McInnies, B.I., Wyllie, P.J.Sulfur variations in glasses from volcanic rocks: effect of melt composition on sulfur solubilityInternational Geology Review, Vol. 36, No. 8, August pp. 703-714GlobalVolcanics, Sulphur content
DS1996-0390
1996
Ducea, M.N.Ducea, M.N., Saleeby, J.B.Bouyancy sources for a large uprooted mountain range, Sierra Nevada, California: evidence from xenoliths...Journal of Geophysical Research, Vol. 101, No. B4, April 10, pp. 8229-8244.CaliforniaMantle xenoliths, Sierra Nevada
DS1998-0369
1998
Ducea, M.N.Ducea, M.N., Saleeby, J.B.The age and origin of a thick mafic ultramafic keel from beneath the Sierra Nevada Batholith.Contributions to Mineralogy and Petrology, Vol. 133, No. 1-2, pp. 169=85.Nevada, Colorado PlateauTectonics
DS200512-0249
2005
Ducea, M.N.Ducea, M.N., Saleeby, J., Morrison, J., Valencia, V.A.Subducted carbonates, metasomatism of mantle wedges, and possible connections to diamond formation: an example from California.American Mineralogist, Vol. 90, pp. 864-870.United States, CaliforniaSierra Nevada mantle, peridotites
DS201012-0472
2010
Ducea, M.N.Manthei, C.D., Ducea, M.N., Girardi, J.D., Patchett, P.Isotopic and geochemical evidence for a recent transition in mantle chemistry beneath the western Canadian Cordillera.Journal of Geophysical Research, Vol. 115, B2, B202204.Canada, Alberta, saskatchewan, Northwest TerritoriesGeochemistry
DS201112-0290
2011
Ducea, M.N.Ducea, M.N.Fingerprinting orogenic delamination.Geology, Vol.39, 2, pp. 191-192.MantleSubduction - recycling
DS201607-1294
2016
Ducea, M.N.Ducea, M.N., Saleeby, J.B., Bergantz, G.The architecture, chemistry and evolution of continental magmatic arcs.Annual Review of Earth and Planetary Sciences, Vol. 43, pp. 299-331.MantleMagmatism

Abstract: Continental magmatic arcs form above subduction zones where the upper plate is continental lithosphere and/or accreted transitional lithosphere. The best-studied examples are found along the western margin of the Americas. They are Earth's largest sites of intermediate magmatism. They are long lived (tens to hundreds of millions of years) and spatially complex; their location migrates laterally due to a host of tectonic causes. Episodes of crustal and lithospheric thickening alternating with periods of root foundering produce cyclic vertical changes in arcs. The average plutonic and volcanic rocks in these arcs straddle the compositional boundary between an andesite and a dacite, very similar to that of continental crust; about half of that comes from newly added mafic material from the mantle. Arc products of the upper crust differentiated from deep crustal (>40 km) residual materials, which are unstable in the lithosphere. Continental arcs evolve into stable continental masses over time; trace elemental budgets, however, present challenges to the concept that Phanerozoic arcs are the main factories of continental crust.
DS1999-0432
1999
Ducharme, E.B.Macek, J.J., Ducharme, E.B., Lettley, C., McGregor, C.R.Thompson nickel belt project: retrieval of core from Falcon bridge Bucko exploration site near Wabowden.Man. Geological Survey Report Activities, pp. 15-17.ManitobaExploration - drilling, Bucko project, Falconbridge Ltd.
DS1997-0293
1997
Duchene, S.Duchene, S., Lardeaux, J.M., Albarade, F.Exhumation of eclogites: insights from depth time path analysisTectonophysics, Vol. 280, No. 1-2, Oct. 26, pp. 125-140.MantleEclogites, Subduction
DS1998-0022
1998
Duchene, S.Allbarede, F., Duchene, S.Simulated garnet clinopyroxene geothermometry of eclogites #1Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 33.MantleThermometry, Eclogites
DS1999-0179
1999
Duchene, S.Duchene, S., Albarede, F.Simulated garnet clinopyroxene geothermometry of eclogites #2Contributions to Mineralogy and Petrology, Vol. 135, No. 1, pp. 75-91.GlobalGeothermometry, Eclogites
DS2001-0705
2001
Duchene, S.Luais, B., Duchene, S., De Sigoyer, J.Sm Nd disequilibrium in high pressure, low temperature Himalayan and Alpine rocksTectonophysics, Vol. 342, No. 1-2, Dec. pp. 1-22.AlpsGeochronology, UHP - high pressure
DS2001-1018
2001
Duchene, S.Sautter, V., Duchene, S., Marques, F.O.New analytical and numerical geospeedometers tested on garnet pyroxenites from Braganca Nappe Complex.Tectonophysics, Vol. 342, No. 1-2, Dec. pp. 39-59.Portugal, northeastGeospeedometry
DS201012-0813
2010
Duchene, S.Vanderhaeghe, O., Duchene, S.Crustal scale mass transfer, geotherm and topography at convergent plate.Terra Nova, Vol. 22, 5, October pp. 315-323.MantleSubduction
DS1985-0160
1985
Duchesne, J.C.Duchesne, J.C., Roelandts, I., Demaiffe, D., Weis, D.Petrogenesis of Monzonitic Dykes in the Egerund Ogna Anorthosite (rogaland S.w. Norway): Trace Elements and Isotopic (sr Pb) Constraints.Contributions to Mineralogy and Petrology, Vol. 90, No. 2-3, PP. 214-225.Norway, ScandinaviaBlank
DS200412-0077
2003
Duchesne, J.C.Auwera, J.V., Bogaerts, M., Liegeois, J.P., De Maiffe, D., Wilmart, E., Bolle, O., Duchesne, J.C.Derivation of the 1.0 0.9 Ga ferro potassic A type granitoids of southern Norway by extreme differentiation from basic magmas.Precambrian Research, Vol. 124, 2-4, pp. 107-148..Europe, NorwayAlkalic
DS201710-2237
2017
Duchkov, A.A.Kulrenya, M.V., Chernyshov, G.S., Serdyukov, A.S., Duchkov, A.A.Procedure and results of seismic investigations into causes of landslides in permafrost rocks.Journal of Mining Science, Vol. 52, 5, pp. 835-841.Russiadeposit - Yubilieny

Abstract: The article focuses on seismic monitoring of causes of landslides. Such studies are of great importance in open pit mining in permafrost rocks. Extensive mining-induced impact in combination with natural thawing of permafrost as a consequence of the planet warming may end in catastrophe. The authors describe a procedure for plotting velocity profiles of seismic waves along slopes in the presence of extremely contrast discontinuities conditioned by permafrost rocks. The presented approach enables studying slip surfaces of landslides and detecting potential failure zones where wave velocities are lower due to extensive jointing. The processed field data obtained in the area near Chagan-Uzun settlement in Kosh-Agach district of the Republic of Altai are reported.
DS1991-0405
1991
Duchkov, A.D.Duchkov, A.D.Review of Siberian heat flow dataTerrestrial Heat Flow and the Lithosphere Structure, editors Cermak, V. and, Springer Verlag, pp. 426-443Russia, SiberiaHeat flow, Geophysics
DS1995-0451
1995
Duchkov, A.D.Duchkov, A.D., Sokolova, L.S.Thermal structure of lithosphere of Siberian PlatformProceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 143-5.Russia, SiberiaGeothermometry, Siberian Platform
DS1997-0294
1997
Duchkov, A.D.Duchkov, A.D., Sokolova, L.S.Thermal structure of the lithosphere of the Siberian PlatformRussian Geology and Geophysics, Vol. 38, No. 2, pp. 528-537.Russia, SiberiaGeothermometry, Mantle structure, tectonics
DS2000-0247
2000
Duchkov, A.D.Duchkov, A.D., Puzankov, Y.M., Sokolova, L.S.Heat flow of kimberlite provinces on cratonsRussian Geology and Geophysics, Vol. 40, No. 7, pp.1078-86.MantleHot spots, Craton - geothermometry
DS2003-0610
2003
Ducker, K.Humphreys, E., Hessler, E., Ducker, K., Farmer, G.L., Erlsev, E., Atwater, T.How Laramide age hydration of North America lithosphere by the Farallon slabInternational Geology Review, Vol. 45, 7, July pp. 575-595.Colorado, WyomingTectonics
DS1991-0406
1991
Duckworth, K.Duckworth, K., Calvert, H.T., Juigali, J.A method for obtaining depth estimates from the geometry of SlingramprofilesGeophysics, Vol. 56, No. 10, October, pp. 1543-1552GlobalGeophysics -electromagnetics, Overburden, host rock
DS1995-0157
1995
Duckworth, R.C.Blake, K.L., Duckworth, R.C.Mineralization styles in the Proterozoic of SwedenShort Course Metallogeny of Proterozoic Basins, 37pSwedenMetallogeny, Proterozoic
DS201412-0245
2014
Duclaux, G.Fisher, L., Gazley, M.F., Baensch, A., Barnes, S.J., Cleverely, J., Duclaux, G.Resolution of geochemical and lithostratigraphic complexity: a workflow for application of portable X-ray fluorescence to mineral exploration.Geochemistry: Exploration, Environment, Analysis, Vol. 14, 2, pp. 139-148.TechnologyGeochemistry
DS1984-0245
1984
Dudar, L.P.Dudar, L.P., Votyakov, S.L., et al.Spectroscopic properties of zircons from the kimberlite rocks ofTiman.(Russian)Mineral. Sbornik, (Russian), Vol.46, pp. 84-89RussiaMineralogy
DS2000-0608
2000
Dudar, V.A.Makeyev, A.B., Dudar, V.A., Bryanchaninova, N.I.Original rocks of Uralian and Timanian diamondsIgc 30th. Brasil, Aug. abstract only 1p.Russia, Urals, TimanDiamond - morphology, Deposit - Ichetju
DS1994-0463
1994
Dudas, F.Dudas, F.Constraints on magma ascent velocities from xenoliths in volcanic pipesEos, Vol. 75, No. 16, April 19, p. 353.MontanaCrazy Mountains, Xenoliths
DS201012-0629
2010
Dudas, F.Rioux, M.,Bowring, S., Dudas, F., Hanson, R.Characterizing the U-Pb systematics of baddeleyite through chemical abrasion: application of multi-step digestion methods to baddelyite geochronology.Contributions to Mineralogy and Petrology, in press available 25p.Africa, South AfricaCarbonatite, Phalaborwa
DS201112-0090
2011
Dudas, F.Blackburn, T., Bowring, S., Perron, T., Mahan, K., Dudas, F.A long term record of continental lithosphere exhumation via U-Pb thermochronology of the lower crust.Goldschmidt Conference 2011, abstract p.532.United States, MontanaCraton, keels
DS201112-0091
2011
Dudas, F.Blackburn, T., Bowring, S.A., Schoene, B., Mahan, K., Dudas, F.U-Pb thermochronology: creating a temporal record of lithosphere thermal evolution.Contributions to Mineralogy and Petrology, in press, availableMantleGeothermometry - xenoliths
DS1987-0165
1987
Dudas, F.O.Dudas, F.O., Carlson R.W., Eggler, D.H.Regional middle Proterozoic enrichment of the subcontinental mantle source of igneous rocks from central MontanaGeology, Vol. 15, No. 1, pp.22-25MontanaUSA, Carbonatite
DS1987-0166
1987
Dudas, F.O.Dudas, F.O., Eggler, D.H.neodymium anomalies and speculations on the role of garnet in the sources of alkalic igneous rocksGeological Society of America, Vol. 19, No. 7 annual meeting abstracts, p.648. abstracMontanaCrazy Mountains, Lamproites
DS1987-0181
1987
Dudas, F.O.Eggler, D.H., Dudas, F.O., Hearn, B.C., McCallum, M.E., McGee, E.S.Lithosphere of the continental United States: Xenoliths in Kimberlites and other alkaline magmasin: Nixon, P.H. ed. Mantle xenoliths, J. Wiley, pp. 41-58United States, Montana, Colorado Wyoming, Kansas, Arkansas, MichiganTennessee, Kentucky, Pennsylvania, New York, Wyoming, Arizon
DS1988-0190
1988
Dudas, F.O.Eggler, D.H., Meen, J.K., Welt, F., Dudas, F.O., Furlong, K.P.Tectonomagmatism of the Wyoming ProvinceColorado School of Mines Quarterly, Vol. 83, No. 2, Summer pp. 25-40Wyoming, MontanaMetasomatism, xenoliths, lithosphere, Missouri Breaks, kimberlites
DS1989-0373
1989
Dudas, F.O.Dudas, F.O.Petrogenesis and mantle source of igneous Rocks in the Crazy Mountains, MontanaPh.D. Thesis, Penn. State Univ, 400pMontanaPetrology, Alkaline rocks
DS1989-0609
1989
Dudas, F.O.Hearn, B.C.Jr., Dudas, F.O., Eggler, D.H., Hyndman, D.W. , O'BrienMontana high pressureotassium igneous province. Crazy Mountains to Montana. July 20-27American Geophysical Union (AGU) 28th. International Geological Congress Field Trip Guidebook, No. T 346, 86pMontanaHighwood Mountains, Minettes, Shonkinites, Lamproites
DS1991-0407
1991
Dudas, F.O.Dudas, F.O.Geochemistry of igneous rocks from the Crazy Mountains, Montana, and tectonic models for the Montana alkalic provinceJournal of Geophysical Research, Vol. 96, No. B8, July 30, pp. 13, 261-13, 278MontanaCrazy Mountains, Alkaline rocks
DS1996-0391
1996
Dudas, F.O.Dudas, F.O.Geochemistry and age of Haymond School dike, southcentral MontanaGeological Society of America, Abstracts, Vol. 28, No. 7, p. A-481.MontanaGeochemistry, Dike
DS1999-0180
1999
Dudas, F.O.Dudas, F.O., Harlan, S.S.An ancient depleted mantle sample from a 42 Ma dike in Montana: constraints on persistence of the lithosphere.Journal of Geology, Vol. 107, No. 3, May pp. 287-300.MontanaMagmatism - Eocene, Wyoming Province, geochronology
DS200912-0676
2009
Dudas, F.O.L.Schoene, B., Dudas, F.O.L., Bowring, S., De Wit, M.Sm Nd isotopic mapping of lithospheric growth and stabilization in the eastern Kaapvaal craton.Terra Nova, Vol. 21, 3, pp. 219-228.Africa, South AfricaGeochronology
DS1983-0202
1983
Dudchik, Y.I.Dudchik, Y.I., Komarov, F.F.The Influence of the Planar Potential Form on the Channeling Radiation Spectrum.Radiation Effects, Vol. 76, No. 3, PP. 61-65.GlobalExperimental Studies, Mineralogy
DS1989-0540
1989
Duddy, I.R.Green, P.F., Duddy, I.R., Leslett, G.M., Hegarty, K.A., GleadowThermal annealing of fission tracks in apatite, 4. Quantitative modelling techniques and extension to geological timescalesChemical Geology, Vol. 79, No. 2, August 1, pp. 155-GlobalGeochronology, Timescales
DS1989-1025
1989
Duddy, I.R.Miller, D.S., Duddy, I.R.Early Cretaceous uplift and erosion of the Northern Appalachian basin, New York, based on apatite fission track analysisEarth and Planetary Science Letters, Vol. 93, No. 1, May pp. 35-49GlobalGeochronology
DS200612-0494
2006
Duddy, I.R.Green, P.K., Duddy, I.R.Interpretation of apatite ( U-Th) /He ages and fission track ages from cratons.Earth and Planetary Science Letters, in pressEurope, Sweden, FennoscandiaGeothermometry, geochronology
DS1984-0356
1984
Dudeney, A.W.L.Hodgson, M., Dudeney, A.W.L.Determination of Olivine and Serpentine in Kimberlites by X-ray Diffraction.Analyst., Vol. 109, No. 9, P. 1129. (abstract.).GlobalMineralogy
DS1984-0357
1984
Dudeney, A.W.L.Hodgson, M., Dudeney, A.W.L.Determination of Olivine and Serpentine in Kimberlite by X Ray Diffraction.Analyst., Vol. 109, No. 9, SEPTEMBER PP. 1129-1133.South AfricaMineralogy, Mineral Chemistry, Wesselton, Analytical Standards
DS1988-0309
1988
Dudeney, A.W.L.Hodgson, M., Dudeney, A.W.L.Hydrothermal alteration of kimberlite in acid media with aluminum ionadditionsTransactions of the Institute of Mining and Metallurgy (IMM), Pt. C Vol. 97, March pp. C1-C14GlobalMineral processing, Kimberlite
DS1985-0534
1985
Dudenov, YU.A.Plotnikova, S.P., Dudenov, YU.A., Malanina, R.V., Kulakov, V.M.The internal structure and properties of a variety of diamond of cubichabit.(Russian)Kristallografiya, (Russian), Vol. 30, No. 6, pp. 1140-1144RussiaDiamond Luminescence, Diamond Morphology
DS1988-0364
1988
Dudkin, O.B.Kogarko, L.N., Kramm, U., Dudkin, O.B., Minakov, F.V.Age and genesis of carbonatites of the Khibiny alkalic pluton as inferred from rubidium-strontium isotope dataDoklady Academy of Science USSR, Earth Science Section, Vol. 289, No. 1-6, January pp. 196-198RussiaBlank
DS1991-0408
1991
Dudkin, O.B.Dudkin, O.B.Carbonatite and the sequence of formation of the Khibiny plutonInternational Geology Review, Vol. 33, No. 4, April pp. 375-384RussiaCarbonatite, Khibiny
DS1992-0399
1992
Dudkin, O.B.Dudkin, O.B.Mineral concentrations in alkaline platform massifsProceedings of the 29th International Geological Congress. Held Japan August 1992, Vol. 2, abstract p. 574Russia, Kola PeninsulaCarbonatite, Alkaline rocks
DS1994-0464
1994
Dudkin, O.B.Dudkin, O.B., Mitrofanov, F.P.Features of the Kola alkali provinceGeochemistry International, Vol. 31, No. 3, pp. 1-11.Russia, Kola PeninsulaAlkaline rocks, Geology
DS2001-0274
2001
Dudkin, O.B.Dudkin, O.B.Geochemistry of carbonatite from the Khibiny pluton and its place among similar rocksGeochemistry International, Vol. 39, No. 7, pp. 711-15.RussiaCarbonatite
DS1986-0199
1986
Dudko, E.A.Dukhovskiy, A.A., Artamonova, N.A., Dudko, E.A., MilshteinDeep structure of the Siberian platform kimberlite fields.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR (Russian), Vol. 290, No. 4, pp. 920-924RussiaTectonics
DS1986-0200
1986
Dudko, E.A.Dukhovskiy, A.A., Artaonova, N.A., Dudko, E.A., Milstein, E.D.Deep structure of the Siberian platform kimberlite field.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 290, No. 4, pp. 920-924RussiaBlank
DS1970-0506
1972
Dudley, P.P.Dudley, P.P.Comments on the Distribution and Age of High-grade Blueschists, Associated Eclogites and Amphibolites from the Tiburon Peninsula, California.Geological Society of America (GSA) Bulletin., Vol. 83, No. 11, PP. 3497-3500.United States, California, West CoastEclogite
DS200512-0250
2005
Dudnikova, V.B.Dudnikova, V.B., Gaister, A.V., Zharikov, E.V., Senin, V.G., Urusov, V.S.Chromium distribution between forsterite and its melt: dependence on chromium content in melt and redox conditions.Geochemistry International, Vol. 43, 5, pp. 471-477.MantleMelting
DS200612-1454
2006
Dudnikova, V.B.Urusov, V.S., Dudnikova, V.B., Zharikov, E.V.Crystal chemical and energy analysis of partition coefficients of impurities during melt crystallization: the case of olivine.Geochemistry International, Vol. 44, 1, pp. 19-32.MantleMantle melting
DS1995-2003
1995
Dudok, I.V.Vityk, M.O., Bodnar, R.J., Dudok, I.V.Natural and synthetic re-equilibration textures of fluid inclusions in quartz (Marmarosh diamonds)refill-European Journ. of Mineralogy, No. 5, pp. 1071-1088.GlobalQuartz - imitation diamonds
DS1996-1486
1996
Dudok, I.V.Vityk, M.O., Bodnar, R.J., Dudok, I.V.Fluid inclusions in Marmarosh diamonds: evidence for tectonic history Of the folded Carpathian Mountains.Tectonophysics, Vol. 255, No. 1-2, April 20, pp. 163-UKraineMarmarosh - not diamonds, Tectonics
DS1984-0246
1984
Duebendorfer, E.M.Duebendorfer, E.M. , Houston, R.S.Structure of a Part of the Cheyenne Belt Eastern Medicine Bow Mountains.Geological Society of America (GSA), Vol. 16, No. 4, P. 220. (abstract.).United States, Wyoming, Rocky Mountains, Medicine Bow MountainsRelated Rocks
DS1987-0167
1987
Duebendorfer, E.M.Duebendorfer, E.M., Houston, R.S.Proterozoic accretionary tectonics at the southern margin of the Archean Wyoming cratonGeological Society of America (GSA) Bulletin, Vol. 98, pp. 554-568United States, WyomingTectonics
DS200412-0489
2004
Duecker, K.Duecker, K., Yuan, H.Upper mantle P wave velocity structure from PASSCAL teleseismic transects across Idaho, Wyoming and Colorado.Geophysical Research Letters, Vol. 31, 8, April 28, DO 10.1029/2004 GLO19476United States, WyomingGeophysics - seismics
DS200512-0283
2004
Duecker, K.Fee, D., Duecker, K.Mantle transition zone topography and structure beneath the Yellowstone hotspot.Geophysical Research Letters, Vol. 31, 18, Sept. 28, 10.1029/2004 GLO20636.MantlePlume
DS1993-0379
1993
Dueholm, K.S.Dueholm, K.S., Garde, m A.A., Pedersen, A.K.Preparation of accurate geological and structural maps, cross sections orb lock diagrams from colour slides, using multi-model photogrammetryJournal of Structural Geology, Vol. 15, No. 7, pp. 933-937GlobalStructure, Maps, slides
DS1994-0792
1994
Dueken, K.G.Humphreys, E.D., Dueken, K.G.Western U.S. upper mantle structureJournal of Geophysical Research, Vol. 99, No. B5, May 10, pp. 9615-9634.Colorado, WyomingMantle, Structure
DS1994-0793
1994
Dueken, K.G.Humphreys, E.D., Dueken, K.G.Physical state of the western U.S. upper mantleJournal of Geophysical Research, Vol. 99, No. B5, May 10, pp. 9635-9650.Colorado, WyomingMantle, Structure
DS1995-0233
1995
Dueker, K.Bump, H., Dueker, K., et al.Colorado Plateau crust and upper mantle structure from the deep probe natural source experiment.Eos, Vol. 76, No. 46, Nov. 7. p.F604. Abstract.Colorado PlateauMantle, Geophysics -seismics
DS2001-0275
2001
Dueker, K.Dueker, K., Yuan, H., Zurek, B.Thick structured Proterozoic lithosphere of the Rocky Mountain regionGsa Today, Dec. pp. 4-9.Colorado PlateauTectonics, tomography, seismics
DS2002-1764
2002
Dueker, K.Yuan, H., Dueker, K.Upper mantle tomographic VP and VS images of the Middle Rocky Mountains in Wyoming, Colorado and New Mexico: evidence for a thick heterogeneous chemical lithosphereGeological Society of America Annual Meeting Oct. 27-30, Abstract p. 473.Wyoming, Colorado, New MexicoTomography
DS2003-0611
2003
Dueker, K.Humphreys, E., Hessler, E., Dueker, K., Farmer, G.L., Erslev, E., Atwater, T.How Laramide age hydration of North American lithosphere by the Farallon SlabInternational Geology Review, Vol. 45, 7, July pp. 575-95.Wyoming, ColoradoSubduction
DS200412-0858
2003
Dueker, K.Humphreys, E., Hessler, E., Dueker, K., Farmer, G.L., Erslev, E., Atwater, T.How Laramide age hydration of North American lithosphere by the Farallon Slab controlled subsequent activity in the Western UnitInternational Geology Review, Vol. 45, 7, July pp. 575-95.United States, WyomingSubduction
DS200512-1226
2005
Dueker, K.Yuan, H., Dueker, K.Upper mantle tomographic Vp and Vs images of the Rocky Mountains in Wyoming, Colorado, New Mexico: evidence for a thick heterogeneous chemical lithosphere.American Geophysical Union, Geophysical Monograph, No. 154, pp. 329-346.United States,Wyoming, Colorado PlateauGeophysics - seismics, tectonics
DS200912-0495
2009
Dueker, K.Mercier, J.P., Bostock, M.G., Cassidy, J.F., Dueker, K., Gaherty, J.B., Garnero, E.J., Revenaugh, ZandtBody wave tomography of western Canada.Tectonophysics, Vol. 475, 2, pp. 480-492.Canada, Alberta, British Columbia, Northwest TerritoriesGeophysics - seismics
DS201412-0249
2014
Dueker, K.Foster, K., Dueker, K., Schmandt, B., Yuan, H.A sharp cratonic lithosphere-asthenosphere boundary beneath the American Midwest and its relation to mantle flow.Earth and Planetary Science Letters, Vol. 402, pp. 82-89.United States, Colorado PlateauGeophysics - seismics
DS201910-2270
2019
Dueker, K.Keifer, I., Dueker, K.Testing the hypothesis that temperature modulates 410 and 660 discontinuity topography beneath the eastern United States.Earth and Planetary Science letters, Vol. 524, 115723 11p.United Statestomography

Abstract: The leading hypothesis to explain 410 and 660 km discontinuity topography and coincident velocity variations is the thermal hypothesis stated as: temperature variations are the primary modulator of discontinuity topography and seismic velocity variations. To test the thermal hypothesis, discontinuity topography maps are correlated with coincident P- and S-velocity variations for the eastern half of the United States sampled by IRIS-EarthScope USArray seismic data. The discontinuity topography maps were made via common-conversion point migration of P-wave receiver functions. The receiver functions were made using a multi-event and multi-station deconvolution method. Fundamental to our results is the choice of three-dimensional P- and S-velocity models, which are used as migration velocity models and for correlation analysis. Two three-dimensional velocity models are used in our analysis: the MITS-model of Golos et al. (2018) and the SL-model of Schmandt and Lin (2014). The Pearson correlation coefficient is used to estimate the degree of linearity between the discontinuity topography and coincident velocity variations. A bivariate regression of discontinuity topography versus coincident velocity variations (termed the mineral physics slope) is performed and compared to a range of slopes constrained by published velocity-temperature derivatives and Clapeyron slopes. Using spatially binning, the discontinuity topography and coincident velocity variations, spatial maps of the correlation coefficient and mineral physics slope are made. Most of the discontinuity sampling area has reasonable correlation values (?0.4) and plausible mineral physics slope values. The veracity of the thermal hypothesis is assessed by integrating the probability density functions of the mineral physics slopes over a domain defined by the published range of 410 and 660 Clapeyron slopes. At the 410, the MITS-model and SL-model thermal hypothesis probabilities are 52% and 51%, respectively, and the seismic Clapeyron slope estimates are 2.7 and 1.3 MPa/K, respectively. At the 660, the MITS-model and SL-model thermal hypothesis probabilities are 54% and 75%, respectively and the seismic Clapeyron slope estimates are ?1.1 and ?1.7 MPa/K, respectively. These Clapeyron slopes estimates are in the middle of plausible Clapeyron slope ranges. Using these Clapeyron slopes, temperature maps show a ±300 K range at the 410 and a ±600 K range at the 660. For regions that are inconsistent with the thermal hypothesis, we suggest that the leading explanations are uncertainties in the velocity models used and secondarily, hydration effects.
DS1992-0738
1992
Dueker, K.G.Humphreys, E.D., Dueker, K.G., Biasi, G.P.Western U.S. tectonic and volcanic activity: the role of the mantleGeological Society of America (GSA) Abstract Volume, Vol. 24, No. 5, May p. 34. abstract onlyMantleTectonics, Structure
DS2000-0425
2000
Dueker, K.G.Humphries, E.D, Dueker, K.G., Schutt, D.L., Smith, R.Beneath Yellowstone: evaluating plume and nonplume models using teleseismic images of the Upper Mantle.Gsa Today, Vol. 10, No. 12, Dec. pp. 1-7.Idaho, WashingtonPlumes - not related to diamonds
DS2003-0465
2003
Dueker, K.G.Gilbert, H.J., Sheehan, A.F., Dueker, K.G., Molnar, P.Receiver functions in the western United States with implications for upper mantleJournal of Geophysical Research, Vol. 108, B5, May 1, 10.1029/2002JB001194.Colorado, WyomingGeophysics - seismics
DS2003-0466
2003
Dueker, K.G.Gilbert, H.J., Sheehan, A.F., Dueker, K.G., Molnar, P.Receiver functions in the western United States, with implications for upper mantleJournal of Geophysical Research, Vol. 108, 5, ETG3 DOI 10.1029/2002JB001194.United States, Colorado, WyomingGeophysics - seismics
DS200412-0664
2003
Dueker, K.G.Gilbert, H.J., Sheehan, A.F., Dueker, K.G., Molnar, P.Receiver functions in the western United States, with implications for upper mantle structure and dynamics.Journal of Geophysical Research, Vol. 108, 5, ETG3 DOI 10.1029/2002 JB001194.United States, Colorado PlateauGeophysics - seismics
DS201312-0360
2013
Dueker, K.G.Hansen, S.M., Dueker, K.G., Stachnik, J.C., Aster, R.C., Karlstrom, K.E.A rootless rockies support and lithospheric structure of the Colorado Rocky Mountains inferred from CREST and TA seismic data.Geochemistry, Geophysics, Geosystems: G3, Vol. 14, 8, pp. 2670-2695.United StatesGeophysics - seismics
DS201412-0779
2014
Dueker, K.G.Schmandt, B., Jacobsen, S.D., Becker, T.W., Liu, Z., Dueker, K.G.Dehydration melting at the top of the lower mantle.Science, Vol. 344, 6189, June 13, pp. 1265-68.MantleWater in transition zone
DS201805-0994
2018
Dueker, K.G.Zhang, Z., Dueker, K.G., Huang, H-H.Ps mantle transition zone imaging beneath the Colorado Rocky Mountains: evidence for an upwelling hydrous mantle.Earth Planetary Science Letters, Vol. 492, pp. 197-205.United States, Coloradomantle - discontinuity

Abstract: We analyze teleseismic P-to-S conversions for high-resolution imaging of the mantle transition zone beneath the Colorado Rocky Mountains using data from a dense PASSCAL seismic broadband deployment. A total of 6,021 P-to-S converted receiver functions are constructed using a multi-channel minimum-phase deconvolution method and migrated using the common converted point technique with the 3-D teleseismic P- and S-wave tomography models of Schmandt and Humphreys (2010). The image finds that the average depths of the 410-km discontinuity (the 410) and 660-km discontinuity (the 660) at and respectively. The peak-to-peak topography of both discontinuities is 33 km and 27 km respectively. Additionally, prominent negative polarity phases are imaged both above and below the 410. To quantify the mean properties of the low-velocity layers about 410 km, we utilize double gradient layer models parameterization to fit the mean receiver function waveform. This waveform fitting is accomplished as a grid-search using anelastic synthetic seismograms. The best-fitting model reveals that the olivine-wadsleyite phase transformation width is 21 km, which is significantly larger than anhydrous mineral physics prediction (4-10 km) (Smyth and Frost, 2002). The findings of a wide olivine-wadsleyite phase transformation and the negative polarity phases above and below the 410, suggest that the mantle, at least in the 350-450 km depth range, is significantly hydrated. Furthermore, a conspicuous negative polarity phase below the 660 is imaged in high velocity region, we speculate the low velocity layer is due to dehydration flux melting in an area of convective downwelling. Our interpretation of these results, in tandem with the tomographic image of a Farallon slab segment at 800 km beneath the region (Schmandt and Humphreys, 2010), is that hydrous and upwelling mantle contributes to the high-standing Colorado Rocky Mountains.
DS201806-1262
2018
Dueker, K.G.Zhang, Z., Dueker, K.G., Huang, H-H.Ps mantle transition zone imaging beneath the Colorado Rocky Mountains: evidence for an upwelling hydrous mantle.Earth and Planetary Science Letters, Vol. 492, pp. 197-205.United States, Coloradogeophysics - seismic

Abstract: We analyze teleseismic P-to-S conversions for high-resolution imaging of the mantle transition zone beneath the Colorado Rocky Mountains using data from a dense PASSCAL seismic broadband deployment. A total of 6,021 P-to-S converted receiver functions are constructed using a multi-channel minimum-phase deconvolution method and migrated using the common converted point technique with the 3-D teleseismic P- and S-wave tomography models of Schmandt and Humphreys (2010). The image finds that the average depths of the 410-km discontinuity (the 410) and 660-km discontinuity (the 660) at and respectively. The peak-to-peak topography of both discontinuities is 33 km and 27 km respectively. Additionally, prominent negative polarity phases are imaged both above and below the 410. To quantify the mean properties of the low-velocity layers about 410 km, we utilize double gradient layer models parameterization to fit the mean receiver function waveform. This waveform fitting is accomplished as a grid-search using anelastic synthetic seismograms. The best-fitting model reveals that the olivine-wadsleyite phase transformation width is 21 km, which is significantly larger than anhydrous mineral physics prediction (4-10 km) (Smyth and Frost, 2002). The findings of a wide olivine-wadsleyite phase transformation and the negative polarity phases above and below the 410, suggest that the mantle, at least in the 350-450 km depth range, is significantly hydrated. Furthermore, a conspicuous negative polarity phase below the 660 is imaged in high velocity region, we speculate the low velocity layer is due to dehydration flux melting in an area of convective downwelling. Our interpretation of these results, in tandem with the tomographic image of a Farallon slab segment at 800 km beneath the region (Schmandt and Humphreys, 2010), is that hydrous and upwelling mantle contributes to the high-standing Colorado Rocky Mountains.
DS200512-0251
2005
Dufek, J.Dufek, J., Bergantz, G.W.Lower crustal magma genesis and preservation: a stochastic framework for the evaluation of basalt crust interaction.Journal of Petrology, Vol. 46, 11, pp. 2167-2195.MantleMagmatism - not specific to diamonds
DS200512-0252
2005
Dufek, J.Dufek, J., Cooper, K.M.226Ra /230Th excess generated in the lower crust: implications for magma transport and storage time scales.Geology, Vol. 33, 10, Oct, pp. 833-36.MantleMelting
DS200812-0982
2008
Dufek, J.Ruprecht, P., Bergantz, G.W., Dufek, J.Modeling of gas driven magmatic overturn: tracking of phenocryst dispersal and gathering during magma mixing.Geochemistry, Geophysics, Geosystems: G3, in press available, 60p.MantleMagmatism
DS201708-1573
2017
Dufek, J.Karakas, O., Degruyter, W., Bachmann, O., Dufek, J.life time and size of shallow magma bodies controlled by crustal-scale magmatism.Nature Geoscience, Vol. 10, 6, p. 446.Mantlemagmatism

Abstract: Magmatic processes on Earth govern the mass, energy and chemical transfer between the mantle, crust and atmosphere. To understand magma storage conditions in the crust that ultimately control volcanic activity and growth of continents, an evaluation of the mass and heat budget of the entire crustal column during magmatic episodes is essential. Here we use a numerical model to constrain the physical conditions under which both lower and upper crustal magma bodies form. We find that over long durations of intrusions (greater than 105 to 106?yr), extensive lower crustal mush zones develop, which modify the thermal budget of the upper crust and reduce the flux of magma required to sustain upper crustal magma reservoirs. Our results reconcile physical models of magma reservoir construction and field-based estimates of intrusion rates in numerous volcanic and plutonic localities. Young igneous provinces (less than a few hundred thousand years old) are unlikely to support large upper crustal reservoirs, whereas longer-lived systems (active for longer than 1 million years) can accumulate magma and build reservoirs capable of producing super-eruptions, even with intrusion rates smaller than 10?3 to 10?2?km3?yr?1. Hence, total duration of magmatism should be combined with the magma intrusion rates to assess the capability of volcanic systems to form the largest explosive eruptions on Earth.
DS1994-0465
1994
Duff, P.McL.D.Duff, P.McL.D.Holmes priciples of physical geologyRoutledge, 791pGlobalPhysical geology -revised Holmes, Book -ad
DS200912-0793
2009
Duffar, T.Venet, L., Duffar, T., Deguen, R.Grain structure of the Earth's inner core.Comptes Rendus Geoscience, In press available, 4p.MantleGeophysics - seismics
DS1989-0374
1989
Duffin, M.E.Duffin, M.E.Nature and origin of authigenic K-feldspar in Precambrian basement Rocks of the North AmericanmidcontinentGeology, Vol. 17, No. 8, August pp. 765-768MidcontinentPrecambrian basement
DS1989-1335
1989
Duffy, D.E.Santner, T.J., Duffy, D.E.Statistical analysis of discrete dataSpringer Verlag Texts in Statistics, 367p. approx.$ 45.00GlobalGeostatistics, Book -Statistics
DS1983-0203
1983
Duffy, S.M.Duffy, S.M.De Beers Is ForeverBarrons, Oct. 31ST. PP. 6-7, 16.South Africa, GlobalInvestment, History, Cso, Diamond
DS201412-0212
2014
Duffy, T.Duffy, T.Crystallography's journey to the deep Earth. Improved methods for studing minerals at extreme pressures and temperatures.Nature, Vol. 506, 7489, pp. 427-429.MantleUHP
DS1995-0452
1995
Duffy, T.S.Duffy, T.S., et al.Elasticity of forsterite to 16 Gps and the composition of the uppermantle.Nature, Vol. 378, No. 6553, Nov. 9, p. 170.MantlePetrology
DS1998-0370
1998
Duffy, T.S.Duffy, T.S., Wang, Y.Pressure volume temperature equations of stateReviews in Mineralogy, Vol. 37, pp. 425-58.MantleMineralogy, Petrology - experimental
DS2000-0892
2000
Duffy, T.S.Shim, S.H., Duffy, T.S., Shen, G.The stability and PVT equation of state of CaSiO3 perovskite in the Earth's lower mantle.Journal of Geophysical Research, Vol.105, No.11, Nov.10, pp.25955-68.MantlePerovskite
DS2001-1064
2001
Duffy, T.S.Shim, S.H., Duffy, T.S., Shen, G.The post spinel transformation in Mg2 SiO4 and its relation to the 660 Km seismic discontinuity.Nature, Vol. No. 6837, pp. 571-3.MantleBoundary
DS2001-1065
2001
Duffy, T.S.Shim, S.H., Duffy, T.S., Shen, G.Stability and structure of MgSiO3 perovskite to 2300 km depth in Earth's mantleScience, Vol. 5539, Sept. 28, pp. 2437-9.MantleCore mantle boundary, Geochemistry
DS200512-0978
2005
Duffy, T.S.Shieh, S.R., Duffy, T.S., Shen, G.X ray diffraction study of phase stability in SiO2 at deep mantle conditions.Earth and Planetary Science Letters, Vol. 235, 1-2, pp. 273-282.MantleGeochemistry
DS200612-1183
2006
Duffy, T.S.Rubie, D.C., Duffy, T.S., Ohtani, E.New developments in high pressure mineral physics and applications to the Earth's interior.Elsevier, 750p. approx. $ 120 USMantleBook - mantle mineralogy, volatiles, rheology, melting
DS200612-1346
2005
Duffy, T.S.Speziale, S., Jiang, F., Duffy, T.S.Compositional dependence of the elastic wave velocities of mantle minerals: implications for seismic properties of mantle rocks.American Geophysical Union, Geophysical Monograph, ed. Van der Hilst, Earth's Deep mantle, structure ...., No. 160, pp. 301-320.MantleGeophysics - seismics
DS200712-0948
2007
Duffy, T.S.Schich, S.R., Duffy, T.S., Liu, Z., Ohtani, E.The hydrogen within the deep mantle.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p.153.MantleHydrogen budget
DS200712-0949
2007
Duffy, T.S.Schich, S.R., Duffy, T.S., Liu, Z., Ohtani, E.The hydrogen within the deep mantle.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p.153.MantleHydrogen budget
DS200712-0981
2007
Duffy, T.S.Shim, S-H., Kubo, A., Duffy, T.S.Raman spectroscopy of perovskite and post-perovskite phases of MgGeO3 to 123 GPa.Earth and Planetary Science Letters, Vol. 260, 1-2, pp. 166-178.MantlePerovskite
DS200712-0982
2007
Duffy, T.S.Shim, S-H., Kubo, A., Duffy, T.S.Raman spectroscopy of perovskite and post-perovskite phases of MgGeO3 to 123 GPa.Earth and Planetary Science Letters, Vol. 260, 1-2, pp. 166-178.MantlePerovskite
DS200812-0300
2008
Duffy, T.S.Duffy, T.S.Some recent advances in understanding the mineralogy of Earth's deep mantle.Philosophical Transactions Royal Society of London Series A Mathematical Physical and Engineering Sciences, Vol. 366, no. 1883, pp. 4273-4294.MantleMineralogy
DS200812-0301
2008
Duffy, T.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
DS200812-0474
2008
Duffy, T.S.Hirose, K., Takafur, N., Fujino, K., Shieh, S.R., Duffy, T.S.Iron partitioning between perovskite and post peroovskite: a transmission electron microscope study.American Mineralogist, Vol. 93, pp. 1678-1681.MantlePhase transition
DS202205-0679
2022
Duffy, T.S.Dutta, R., Tracy, S.J., Cohen, R.E. , Miozzi, F., Luo, K., Yang, J., Burnley, P.C., Smith, D., Meng, Y., Chariton, S., Prakapenka, V.B., Duffy, T.S.Ultrahigh-presssure disordered eight-coordinated phase of Mg2GeO4: analogue for super Earth mantles. GermaniumPNAS, https://doi.org/10.1073/pnas.2114424119Mantlegeodynamics

Abstract: Mg2GeO4 is important as an analog for the ultrahigh-pressure behavior of Mg2SiO4, a major component of planetary interiors. In this study, we have investigated magnesium germanate to 275 GPa and over 2,000 K using a laser-heated diamond anvil cell combined with in situ synchrotron X-ray diffraction and density functional theory (DFT) computations. The experimental results are consistent with the formation of a phase with disordered Mg and Ge, in which germanium adopts eightfold coordination with oxygen: the cubic, Th3P4-type structure. DFT computations suggest partial Mg-Ge order, resulting in a tetragonal I4Ż2d structure indistinguishable from I4Ż3d Th3P4 in our experiments. If applicable to silicates, the formation of this highly coordinated and intrinsically disordered phase may have important implications for the interior mineralogy of large, rocky extrasolar planets.
DS200612-1014
2006
Dufour, F.O'Neill, C., Moresi, L., Muller, D., Albert, R., Dufour, F.Ellipse 3D: a particle in cell finite element hybrid code for modelling mantle convection and lithosphere deformation.Computers & Geosciences, Vol. 32, 10, pp. 1769-1779.TechnologyComputer program - convection model
DS201112-0223
2011
DuFrane, S.A.Crow, R., Karlstrom, K., Asmerom, Y., Schmandt, B., Polyak, V., DuFrane, S.A.Shrinking of the Colorado Plateau via lithospheric mantle erosion: evidence from Nd and Sr isotopes and geochronology of Neogene basalts.Geology, Vol. 39, 1, pp. 27-30.United States, Colorado PlateauGeochronology
DS201312-0838
2013
Dufrane, S.A.Smit, K.V., Stachel, T., Creaser, R.A., Ickert, R.B., Dufrane, S.A., Stern, R.A., Seller, M.Origin of eclogite and pyroxenite xenoliths from the Victor kimberlite, Canada, and implications for Superior Craton formation.Geochimica et Cosmochimica Acta, Vol. 125, pp. 308-337.Canada, OntarioDeposit - Victor
DS201412-0845
2014
DuFrane, S.A.Smit, K.V., Stachel, T., Creaser, R.A., Ickert, R.B., DuFrane, S.A., Stern, R.A., Seller, M.Origin of eclogite and pyroxenite xenoliths from the Victor kimberlite, Canada, and implications for Superior craton formation.Geochimica et Cosmochimica Acta, Vol. 125, pp. 308-337.Canada, Ontario, AttawapiskatDeposit - Victor
DS201812-2787
2018
Dufrane, S.A.Buryak, S., Reyes, A.V., Siver, P.A., Li, L., Dufrane, S.A.Bulk organic geochemistry and U-Pb zircon geochronology of the Wombat sedimentary fill.2018 Yellowknife Geoscience Forum , p. 98-99. abstractCanada, Northwest Territoriesdeposit - Wombat

Abstract: The Wombat locality (64.73°N, 110.59°W) is a diamondiferous kimberlite in the Lac de Gras kimberlite field of Northwest Territories. Two drill cores, CH 93-29 and DDH 0-005, intersect the Wombat crater facies and include 195 m of well preserved, undisturbed lake sediment fill. Bulk sediment elemental analysis, C isotope composition, and Rock-Eval pyrolysis, together with inferences from microfossils, are used to characterize conditions of sedimentation and paleoenvironment in the maar lake. Bulk sediment C/N, hydrogen index (HI), and ?13C indicate material derived from C3 land plants dominates the sedimentary organic matter, with a minor algal contribution. The ?13C values range from -25.3 ‰ to -30.2 ‰ (average -26.6 ‰) and are typical for C3 land plants, with fluctuations in ?13C likely related to shifts in the proportions of land-derived material and algal organic matter. An overall trend of higher ?13C towards the top of the core suggests increasing autochthonous organic matter production. 18 samples analyzed by Rock-Eval pyrolysis all plot in the Type III kerogen field for HI vs. Tmax,with average Tmax values ~425 °C indicative of the low thermal maturity of organic matter. Total organic carbon (TOC) averages 3.6 wt.% and average total carbonate content is 14.1 wt.%, indicating bottom water anoxia and substantial carbonate input from weathering of overlying carbonate cover rocks, respectively. Together with well-preserved freshwater microfossils (e.g. diatoms, chrysophytes, synurophytes), the results indicate deposition in a non-marine setting. The age of the Wombat maar lake sediments is determined using MC-LA-ICP-MS U-Pb zircon geochronology from two distal rhyolitic tephra beds found in the core DDH 0-005, yielding a date of 82.97±0.60 Ma (MSWD = 1.7, n=18 of 33 grains analyzed). This minimum age suggests that Wombat kimberlite pipe emplacement occurred during the Late Cretaceous, with sedimentation in the maar beginning shortly thereafter. Though our geochronology is preliminary at this point, our findings from the Wombat pipe post-eruptive lake sediment fill provide direct evidence for a non-marine environment in the Lac De Gras area during the Late Cretaceous. Furthermore, microfossils in the Wombat pipe sediment fill likely include the oldest-known occurrence of freshwater diatoms.
DS200712-0968
2007
DuFrane, W.Sharp, T.G., Diedrich, T., Marton, F.C., DuFrane, W.Subduction of hydrated lithosphere: 300 ppm H2O in subducting olivine would eliminate the metastable olivine wedge.Plates, Plumes, and Paradigms, 1p. abstract p. A923.MantleSubduction
DS1999-0181
1999
Dufresne, M.Dufresne, M.Diamond exploration in northern Alberta: an update8th. Calgary Mining forum, 1p. abstractAlbertaNews item
DS2001-0287
2001
Dufresne, M.Eccles, D.R., Dufresne, M., Copeland, D., Csanyi, W., Creighton, S.Alberta kimberlite indicator mineral geochemical compilationAlberta Geological Survey, www.ags.gov.ab.ca, ESR 01-20, $ 20.AlbertaGeochemistry - database
DS1994-0466
1994
Dufresne, M.B.Dufresne, M.B., Olson, R.A., Schmitt, D.R., et al.The diamond potential of Alberta: a regional synthesis of structural and stratigraphic setting and potential.Alberta Research Council, Open file, 1994-10, $ 85.00AlbertaStructure, Stratigraphy, diamonds
DS1997-0174
1997
Dufresne, M.B.Chain, L., Dufresne, M.B.Metallic and industrial mineral assessment report on the field and sampling program for Cadotte Lake area.Alberta Geological Survey, MIN 19970011AlbertaExploration - assessment, Utrasonic Industrial Ltd.
DS1997-0343
1997
Dufresne, M.B.Fenton, M.M., Pawlowicz, J.G., Dufresne, M.B.Till mineralogy and geochemistry in northern Alberta: updateGeological Survey of Canada Forum 1997 abstracts, p. 21. AbstractAlbertaGeochemistry, Till
DS1998-0371
1998
Dufresne, M.B.Dufresne, M.B., Olsen, R.A., Eccles, D.R., Fenton, et al.Alberta diamonds - an update on the newly emerging diamondiferous kimberlite field in western Canada. #2Calgary Mining Forum, Apr. 8-9, p. 21-3. abstractAlbertaRegional geology, History
DS1998-0378
1998
Dufresne, M.B.Eccles, D., Lywood, P., Dufresne, M.B.Diamond and metallic mineral potential of the Kakwa Wapiti areaCalgary Mining Forum, Apr. 8-9, p. 59. poster abstractAlbertaGeochemistry - Heavy minerals
DS1998-1098
1998
Dufresne, M.B.Olson, R.A., Dufresne, M.B.Alberta diamonds - an update on the newly emerging diamondiferous kimberlite field in western Canada. #1Handout - extended abstract, 7p.AlbertaNews item
DS1998-1130
1998
Dufresne, M.B.Pawlowicz, J.G., Dufresne, M.B., Fenton, M.M.Diamond indicator mineral anomaly from till, Northern AlbertaAlberta Geological Survey, Geo Notes 98-01.Alberta, NorthernGeochemistry
DS1998-1131
1998
Dufresne, M.B.Pawlowicz, J.G., Dufresne, M.B., Fenton, M.M.Diamond indicator minerals from auger core holes, a possible second dispersal ttrain in the Peerless area.Alberta Geological Survey, Geo Notes 98-02.Alberta, NorthernGeochemistry
DS1998-1538
1998
Dufresne, M.B.Vernet, D., Dufresne, M.B.Metallic and industrial mineral assessment report on the Pelican Mountain area, Alberta.Alberta Geological Survey, MIN 19980009AlbertaExploration - assessment, Ellesmere Minerals Limited
DS1999-0182
1999
Dufresne, M.B.Dufresne, M.B., Copeland, D.A.Evaluation of the diamond potential of Ice River mining Martineau River property.Alberta Geological Survey, MIN 19990029AlbertaExploration - assessment, Sunburst Mines, Ice River Mining
DS2000-0248
2000
Dufresne, M.B.Dufresne, M.B., Eccles, D.R.Diamond indicator minerals and trends in northern AlbertaGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) Calgary May 2000, 1p.AlbertaSampling - indicator minerals, brief - history
DS2002-0407
2002
Dufresne, M.B.Dufresne, M.B., Noyes, A.K.The diamond potential of the Brilliant Mining Corporation's Medley River property, East Central Alberta.Mineral Assesment Files, Alberta Geological Survey, www.ags.gov.ab.ca, MIN 0105AlbertaAssessment - Medley River area
DS1990-0303
1990
Dugan, J.P. Jr.Chan, Chien-Lu, Dugan, J.P. Jr.Krypton and xenon isotopic compositions of carbonatite calcite from the Magnet Cove complex, ArkansawGeological Society of America (GSA) Annual Meeting, Abstracts, Vol. 22, No. 7, p. A160ArkansasCarbonatite, Geochronology
DS1990-0431
1990
Dugan, J.P.Jr.Dugan, J.P.Jr., Chan, Chien-LuKrypton and xenon isotopic compositions of peridotite in the Prairie Creek Complex, ArkansawV.m. Goldschmidt Conference Held May 2-4, 1990, Program And Abstract, p. 42. Abstract onlyArkansasGeochronology, Geochemistry
DS1992-0400
1992
Dugan, J.P.Jr.Dugan, J.P.Jr., Chien-Lu ChenCalcite inclusion in a a diamond from ArkansawEos, Transactions, Annual Fall Meeting Abstracts, Vol. 73, No. 43, October 27, abstracts p. 657ArkansasDiamond inclusion, Calcite
DS1900-0746
1909
Duggan, C.A.O.Duggan, C.A.O.Down the Chute: a Miner's Extraordinary ExperienceWide World Magazine., Vol. 22, Feb. PP. 436-442.Africa, South AfricaHistory, Mining
DS1989-1248
1989
Duggan, J.S.Raab, G.A., Enwall, R.E., Cole, W.H., Kuharic, C.A., Duggan, J.S.Fast analysis of heavy metals in contaminated soils using field -portable X-ray fluorescence technology and geostatisticsPreprint from Northwest Mining Association 95th. Annual Meeting held Dec., 19pGlobalGeostatistics, X-ray fluorescence Heavy metals
DS1995-0453
1995
Duggan, K.M.Duggan, K.M., Chamberlain, K.R., Frost, B.Late to post orogenic extension in a Proterozoic arc continent collisionalzone, southeastern Wyoming.Geological Society of America (GSA) Abstracts, Vol. 27, No. 6, abstract p. A 161.WyomingTectonics, Medicine Bow Mountains
DS1984-0414
1984
Duggan, M.B.Knutson, J., O'reilly, S.Y., Duggan, M.B., Jaques, A.L.The Nature of the Lower Crust and Upper Mantle Beneath Eastern Australia As Inferred from Xenolith Studies.Geological Society of Australia., No. 12, ABSTRACT VOLUME PP. 310-311.Australia, Eastern AustraliaXenoliths, Petrography
DS1994-0467
1994
Duggan, M.B.Duggan, M.B., Jaques, A.L.Proterozoic shoshonitic lamprophyres from Tennant CreekGeological Society of Australia Abstract Volume, No. 37, pp. 87.AustraliaShoshonite, Lamprophyre, dikes
DS1996-0392
1996
Duggan, M.B.Duggan, M.B., Jaques, A.L.Mineralogy and geochemistry of Proterozoic shoshonitic lamprophyres From the Tennant Creek Inlier.Australian Journal of Earth Sciences, Vol. 43, No. 3, June 1, pp. 269-278.AustraliaLamprophyres, Shoshonite
DS2002-0728
2002
DuggenHoenle, K., Tilton, G., LeBas, Duggen, GarbeSchonbergGeochemistry of oceanic carbonatites compared with continental carbonatites; mantle recycling of oceanic..Contribution to Mineralogy and Petrology, Vol.142, 5, pp.520-42.Mantle, OceanicCarbonatite - recycling crustal carbonate
DS2002-0729
2002
DuggenHoernle, K., Tilton, Le Bas, Duggen, Garbe-SchonbergGeochemistry of oceanic carbonatites compared with continental carbonatites: mantle recycling of oceanic..Contributions to Mineralogy and Petrology, Vol. 142, No. 5, Feb. pp. 520-42.MantleGeochemistry, Carbonatite - crustal carbonate
DS200912-0189
2009
Duggen, K.A.Duggen, K.A., Hoernle, F., Hauff, A., Klugel, M., Bouabdellah, Thirwall, M.F.Flow of Canary mantle plume material through a subcontinental lithospheric corridor beneath Africa to the Mediterranean.Geology, Vol. 37, 3, pp. 283-286.EuropePlume
DS200812-0120
2008
Duggen, S.Boanadiman, C., Coltari, M., Duggen, S., Paludetti, L., Siena,F.,Thirwall, M.F., Upton, BGJ.Paleozoic subduction related and kimberlite or carbonatite metasomatism in the Scottish lithospheric mantle.Geological Society of London, Special Publications no. 293, pp. 303-334.Europe, ScotlandSubduction
DS201012-0068
2010
Duggen, S.Bouabdellah, M., Hoernle,K., Kchit, A., Duggen, S., Hauff, Klugel, Lowry, BeaudoinPetrogenesis of the Eocene Tamzert continental carbonatites ( central High Atlas, Morocco): implications for a common source for Tamzert and CanaryJournal of Petrology, Vol. 51, 8, pp. 1655-1686.Europe, Canary Islands, MoroccoCarbonatite
DS1988-0181
1988
Duickas, A.B.Duickas, A.B., Mudrey, M.G.Jr.A midcontinent rift model based upon Gregory rift tectonic and sedimentation geometriesGeological Society of America Abstracts with Program, Vol. 20, No. 2, January p.96-7. Sth. Central, LawrenceWisconsin, KenyaMid continent
DS1983-0204
1983
Duijvestijn, M.J.Duijvestijn, M.J., Lugt, C. Van Der., et al.13 C Nmr Spectroscopy in Diamonds Using Dynamic Nuclear Polarization.Chemical Physics Letters, Vol. 102, No. 1, Nov. 11TH. PP. 25-28.GlobalSpectroscopy, Natural Diamonds, Carbon
DS1997-0031
1997
Duiski, P.Andrade, F.R.D., Bau, M., Duiski, P.Zirconium and hafnium in carbonatites: a re-evaluationGeological Association of Canada (GAC) Abstracts, GlobalCarbonatite
DS1950-0348
1957
Dujardin, R.A.Pollard, E.R., Dixon, C.G., Dujardin, R.A.Diamond Resources of British GuianaBritish Guiana Geological Survey, Bulletin. 28, 43p.GlobalDiamond Occurrences
DS1994-0468
1994
Duk Rodkin, A.Duk Rodkin, A., Hughes, O.L.Tertiary Quaternary drainage of the pre-glacial Mackenzie BasinInqua., Vol. 22/23, pp. 221-241.Northwest Territories, British Columbia, Alberta, SaskatchewanGeomorphology, Mackenzie Basin
DS1994-0469
1994
Duk Rodkin, A.Duk Rodkin, A., Hughes, O.L.Tertiary Quaternary drainage of the pre-glacial Mackenzie BasinInqua., Vol. 22-23, pp. 221-241Northwest Territories, British Columbia, Alberta, SaskatchewanGeomorphology, Mackenzie Basin
DS2002-0408
2002
Duk Rodkin, A.Duk Rodkin, A.Preglacial drainage and placer diamond potential in the Northwest Territories of Canada.Geological Society of Australia Abstracts, Vol. 67, p. 410. abstract.Northwest TerritoriesGeomorphology
DS1998-1644
1998
Dukardt, Y.A.Zinchouk, N.N., Dukardt, Y.A., Boris, Y.I.Specific features of zoning of ancient platforms' territories according To the degree of perspectiveness7th International Kimberlite Conference Abstract, pp. 1020-23.Russia, Siberia, YakutiaTectonic metamorphic stages, Craton
DS200512-0253
2004
Duke, G.I.Duke, G.I., Frost, C.D.Carbonatite fingerprints on Black Hills alkalic suite?Geological Society of America Annual Meeting ABSTRACTS, Nov. 7-10, Paper 88-27, Vol. 36, 5, p. 224.United States, Montana, South DakotaMagmatism
DS200912-0190
2009
Duke, G.I.Duke, G.I.Black Hills - Alberta carbonatite - kimberlite linear trend: slab edge at depth?Tectonophysics, Vol. 464, pp. 186-194.Canada, Alberta, United States, MontanaKimberlite
DS200912-0191
2008
Duke, G.I.Duke, G.I., Carlson, R.W., Eby, G.N.Two distinct sets of magma sources in Cretaceous rocks from Magnet Cove, Prairie Creek, and other igneous centres of the Arkansas Alkaline Province, USA.American Geological Union, Fall meeting Dec. 15-19, Eos Trans. Vol. 89, no. 53, meeting supplement, 1p. abstractUnited States, ArkansasLamproite
DS201412-0213
2014
Duke, G.I.Duke, G.I., Carlson, R.W., Frost, C.D., Hearn, B.C.Jr., Eby, G.N.Continental scale linearity of kimberlite-carbonatite magmatism, mid-continent North America.Earth and Planetary Science Letters, Vol. 403, pp. 157-163.Canada, United StatesLineaments
DS1975-1000
1979
Duke, J.M.Duke, J.M.Computer simulation of the fractionation of olivine and sulphide from mafic and ultramafic magmas.Can. Min., Vol. 17, pp. 507-14.GlobalMagmatism - Not Specific To Diamonds
DS1982-0180
1982
Duke, J.M.Duke, J.M., Bonardi, M.Chromian and radite from Reaume TownshipCan. Min., Vol. 20, pp. 49-53.OntarioWehrite, Garnet Mineralogy
DS1993-0820
1993
Duke, J.M.Kirkham, R.V., Sinclair, W.D., Thorpe, R.I., Duke, J.M.Mineral deposit modelling ( proceedings of conference UNESCO held August1990)Geological Association of Canada (GAC), $ 40.00 plusGlobalBook -table of contents, Mineral deposit modeling
DS1995-0951
1995
Duke, J.M.Kikrham, R.V., Sinclair, W.D., Thorpe, R.I., Duke, J.M.Mineral deposit modelingGeological Association of Canada (GAC) Special Paper, No. 40, 800pGlobalMineral deposit modeling, Resources, economics, SEDEX, VMS, Magmatic, hydrothermal
DS1989-0083
1989
Duke, N.A.Barron, K.M., Duke, N.A., Hodder, R.W.A high level Archean alkaline carbonatite complex,Springpole Lake NorthWest OntarioGeological Association of Canada (GAC) Annual Meeting Program Abstracts, Vol. 14, p. A72. (abstract.)OntarioCarbonatite
DS1989-0084
1989
Duke, N.A.Barron, K.M., Duke, N.A., Hodder, R.W.Petrology of the Springpole Lake alkalic volcanic complexOntario Geological Survey miscellaneous Paper, No. 143, pp. 133-145OntarioAlkaline rocks, Springpole Lake complex
DS2000-0030
2000
Duke, N.A.Armstrong, J.P., Strand, P.D., Duke, N.A.Archean lamprophyre diking, Yellowknife Greenstone Belt, between mantle sourced magmatic events, ....28th. Yellowknife Geoscience Forum, p. 7-8.abstractNorthwest TerritoriesLamprophyre - dykes
DS1989-0375
1989
Duke, W.E.Duke, W.E.Other bank financingMine Financing seminar, held April 17th. Toronto, Database # 17803GlobalMine financing, Economics, Alternative banks
DS1975-0501
1977
Dukes, J.W.Sr.Dukes, J.W.Sr.A Field Trip for DiamondsLapidary Journal, Vol. 30, No. 11, P. 2610.United States, Great Lakes, WisconsinBlank
DS1996-0013
1996
Dukhanin, A.S.Alekseev, S.G., Dukhanin, A.S., Veshev, S.A., Voroshilov, N.A.Some aspects of practical use of geoelectrochemical methods of exploration for deep seated mineralizationJournal of Geochem. Explor, Vol. 56, No. 1, June, pp. 79-86RussiaGeochemical exploration, Mineralization -at depth
DS1950-0383
1958
Dukhanin, S.F.Dukhanin, S.F., Krutoyariskiy, M.A.Interpretation of Aerial Photographs in Prospecting for Kimberlite Bodies.Inf. Bulletin. Niiga., No. 10, PP. 59-65.RussiaBlank
DS1984-0247
1984
Dukhovskii, A.A.Dukhovskii, A.A.Regional Regularities of Spatial Distribution of Kimberlite magmatism of East Siberia from Geophysical Data.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 275, No. 5, PP. 1136-1140.RussiaKimberlite, Geophysics
DS1986-0197
1986
Dukhovskiy, A.A.Dukhovskiy, A.A.Regional patterns in the areal distribution of kimberlite magmatism In eastern Siberia, as suggested by geophysical dataDoklady Academy of Science USSR, Earth Science Section, Vol. 276, January pp. 89-93RussiaGeophysics, structure, Gravity
DS1986-0198
1986
Dukhovskiy, A.A.Dukhovskiy, A.A., Artamonova, N.A., Belyayev, G.M., Nikishov, K.N.Structural controls on kimberlite formation in the Anabar megablockInternational Geology Review, Vol. 28, No. 11, Nov. pp. 1336-1345RussiaStructure, Tectonics, Geophysics, gravity
DS1986-0199
1986
Dukhovskiy, A.A.Dukhovskiy, A.A., Artamonova, N.A., Dudko, E.A., MilshteinDeep structure of the Siberian platform kimberlite fields.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR (Russian), Vol. 290, No. 4, pp. 920-924RussiaTectonics
DS1986-0200
1986
Dukhovskiy, A.A.Dukhovskiy, A.A., Artaonova, N.A., Dudko, E.A., Milstein, E.D.Deep structure of the Siberian platform kimberlite field.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 290, No. 4, pp. 920-924RussiaBlank
DS1988-0182
1988
Dukhovskiy, A.A.Dukhovskiy, A.A., Artamonova, N.A., Duko, Ye.A., Milshteyn, Ye.D.Deep structure of the kimberlite fields of the Siberian PlatformDoklady Academy of Science USSR, Earth Science Section, Vol. 290, No. 1-6, March pp. 122-124RussiaStructure, Kimberlite fields
DS1988-0182
1988
Duko, Ye.A.Dukhovskiy, A.A., Artamonova, N.A., Duko, Ye.A., Milshteyn, Ye.D.Deep structure of the kimberlite fields of the Siberian PlatformDoklady Academy of Science USSR, Earth Science Section, Vol. 290, No. 1-6, March pp. 122-124RussiaStructure, Kimberlite fields
DS1994-1026
1994
Duk-Rodkin, A.Lemmen, D.S., Duk-Rodkin, A., Bednarski, J.M.Late glacial drainage systems along the northwestern margin of the Laurentide ice sheet.Quat. Science Reviews, Vol. 13, pp. 805-828.Northwest Territories, British Columbia, MontanaGeomorphology
DS1996-0076
1996
Duk-Rodkin, A.Barendregt, R.W., Enkin, R.J., Duk-Rodkin, A., Baker, J.Paleomagnetic evidence for late Cenozoic glaciations in the Mackenzie Mountains of the Northwest TerritoriesCanadian Journal of Earth Sciences, Vol. 33, No. 6, June pp. 896-903.Northwest TerritoriesGeomorphology, Paleomagnetism
DS202201-0010
2021
Duk-Rodkin, A.Ciadullo, E., Flemming, R., Currie, L., Duk-Rodkin, A.Provenance of kimberlite indicator minerals from Saglek basin, Labrador Sea, Canada.GAC/MAC Meeting UWO, 1p. Abstract p. 72.Canada, Labradordeposit - Saglek

Abstract: The Mokami and Saglek formations are comprised of Middle Eocene to Plio-Pleistocene deltaic deposits in the Labrador Sea, at the mouth of the Hudson Strait. In this study we use the provenance of KIM minerals to investigate the origin of these sediments. Fifty one mineral grains were obtained from Miocene to possibly Pliocene Mokami and Saglek formation strata by sub-sampling ocean cuttings from the Petro-Canada et al. Rut H-11 well. These grains were examined by optical methods, micro X-ray diffraction (?XRD) and Electron Probe Microanalysis (EPMA) at Western University for identification purposes, and 20 grains were determined to be of peridotitic mantle origin, based on the well-established compositional and mineral-formula discrimination criteria. The compositions of these Kimberlite Indicator Minerals (KIMs) have been compared to equivalent mineral grains from known Canadian kimberlite deposits, in a preliminary attempt to determine their provenance. Out of eleven garnets in the suite, nine garnets were classified as G9, thus establishing their lherzolitic mantle origin; one garnet was wehrlitic (G12), and one garnet was crustal (G0) (Fig 1A). The presence of G9 garnets, however, does not indicate provenance, as G9 garnets are ubiquitous in the mantle. Three Cr-diopside grains were found in the suite. They all passed compositional and mineral-formula criteria established by Ziberna et al. (2016) to be recognized as peridotitic. On Al+Cr-Na-K versus Ca/(Ca+Mg+Fe) plots (e.g. Grütter 2009, Fig. 4), these grains plotted in a region occupied by both garnet peridotite and spinel-garnet peridotite, such that formation in the presence of garnet is confirmed, but the type of peridotite is not definitive. These grains were used to calculate P-T conditions of formation using the Nimis and Taylor (2000) thermobarometer, and the Cr-diopside grains revealed P-T formation conditions ranging from 1304-1417 °C and 4.5-5.2 GPa (Fig 1B). These grains plot in the P-T region representing an extension of that occupied by both Somerset and Kirkland Lake kimberlites, however, calculated temperatures significantly above 1300 °C should be treated the caution because this has not been reported for Cr-diopside from any Canadian kimberlites. It is worth noting that the Cr-diopside grains definitively do not match those from the Chidliak kimberlites, although that kimberlite field is located geographically proximal to the Saglek deposit. Seven orthopyroxene grains found in the suite had compositions matching kimberlites from the Slave craton (Fig. 1C). This provenance agrees with the paleo-drainage pattern of the Bell River basin, which extended from the Northern Interior plains to the Sea of Labrador until the late Pleistocene.
DS201807-1512
2018
Dukstra, A.H.Marien, C., Dukstra, A.H., Wilkins, C.The hydrothermal alteration of carbonatite in the Fen complex, Norway: mineralogy, geochemistry and implications for rare earth element resource formation.Mineralogical Magazine Open access special publication Critical metal mineralogy and ore genesis, Vol. 82 (S1) pp. S115-S131.Europe, Norwaycarbonatite

Abstract: The Fen Complex in Norway consists of a ~583 Ma composite carbonatite-ijolite-pyroxenite diatreme intrusion. Locally, high grades (up to 1.6 wt.% total REE) of rare-earth elements (REE) are found in a hydrothermally altered, hematite-rich carbonatite known as rřdbergite. The progressive transformation of primary igneous carbonatite to rřdbergite was studied here using scanning electron microscopy and inductively coupled plasma-mass spectrometry trace-element analysis of 23 bulk samples taken along a key geological transect. A primary mineral assemblage of calcite, dolomite, apatite, pyrite, magnetite and columbite with accessory quartz, baryte, pyrochlore, fluorite and REE fluorocarbonates was found to have transformed progressively into a secondary assemblage of dolomite, Fe-dolomite, baryte, Ba-bearing phlogopite, hematite with accessory apatite, calcite, monazite-(Ce) and quartz. Textural evidence is presented for REE fluorocarbonates and apatite breaking down in igneous carbonatite, and monazite-(Ce) precipitating in rřdbergite. The importance of micro-veins, interpreted as feeder fractures, containing secondary monazite and allanite, is highlighted. Textural evidence for included relics of primary apatite-rich carbonatite are also presented. These acted as a trap for monazite-(Ce) precipitation, a mechanism predicted by physical-chemical experiments. The transformation of carbonatite to rřdbergite is accompanied by a 10-fold increase in REE concentrations. The highest light REE (LREE) concentrations are found in transitional vein-rich rřdbergite, whereas the highest heavy REE (HREE) and Th concentrations are found within the rřdbergites, suggesting partial decoupling of LREE and HREE due to the lower stability of HREE complexes in the aqueous hydrothermal fluid. The hydrothermal fluid involved in the formation of rřdbergite was oxidizing and had probably interacted with country-rock gneisses. An ore deposit model for the REE-rich rřdbergites is presented here which will better inform exploration strategies in the complex, and has implications for carbonatite-hosted REE resources around the world.
DS201112-0784
2011
Dulapchii, E.V.Pervov, S., Somov, V., Korshunov, A.V., Dulapchii, E.V.The Catoca kimberlite pipe, Republic of Angola: a paleovolcanological model.Geology of Ore Deposits, Vol. 53, no. 4, pp. 295-308.Africa, AngolaDeposit - Catoca
DS1986-0835
1986
Duliski, P.Viladkar, S.G., Duliski, P.Rare earth element abundances in carbonatites, alkaline rock sand fenites of the Amba Dungar Complex Gujarst India.Neues Jahrbuch f?r Mineralogie Petrol, No. 1, January pp. 37-48IndiaRare earth, Alkaline rocks
DS2003-0161
2003
Duller, G.A.Bristow, C.S., Lancaster, N., Duller, G.A.Combining ground penetrating radar and optical dating to determine dune migration inGeological Society of America, Annual Meeting Nov. 2-5, Abstracts p.300.NamibiaGPR, geomorphology
DS200412-0209
2003
Duller, G.A.Bristow, C.S., lancaster, N.,Duller, G.A.Combining ground penetrating radar and optical dating to determine dune migration in Namibia.Geological Society of America, Annual Meeting Nov. 2-5, Abstracts p.300.Africa, NamibiaGPR, geomorphology
DS1997-0137
1997
Dullo, W. Ch.Bruns, P., Rakoczy, H., Dullo, W. Ch.Slow sedimentation and Ir anomalies at the Cretaceous/ Tertiary boundaryGeologische Rundschau, Vol. 86, No. 1, pp. 168-177GlobalBoundary, Iridium anomalies
DS2002-0218
2002
Dulski, P.Buhn, B., Rankin, A.H., Schneider, J., Dulski, P.The nature of orthomagmatic, carbonatitic fluids precipitating REE Sr rich flourite, fluid inclusion...Chemical Geology, Vol.186,1-2, pp. 75-98., Vol.186,1-2, pp. 75-98.NamibiaGeochronology - fluorite, Deposit - Okorusu
DS2002-0219
2002
Dulski, P.Buhn, B., Rankin, A.H., Schneider, J., Dulski, P.The nature of orthomagmatic, carbonatitic fluids precipitating REE Sr rich flourite, fluid inclusion...Chemical Geology, Vol.186,1-2, pp. 75-98., Vol.186,1-2, pp. 75-98.NamibiaGeochronology - fluorite, Deposit - Okorusu
DS200512-0948
2004
Dulski, P.Schultz, F., Lehmann, B., Tawackoli, S., Rossling, R., Belyatsky, B., Dulski, P.Carbonatite diversity in the Central Andes: the Ayopaya alkaline province, Bolivia.Contributions to Mineralogy and Petrology, Vol. 148, 4, pp. 391-408.South America, BoliviaCarbonatite
DS200912-0457
2008
Dulski, P.Lucassen, F., Franz, G., Romer, G.L., Dulski, P.Late Cenozoic xenolths as a guide to the chemical isotopic composition and thermal state of the upper mantle under northeast Africa.European Journal of Mineralogy, Vol. 20, 6, pp. 1079-1096.AfricaGeochemistry
DS201112-0621
2011
Dulski, P.Lucassen, F., Franz, G., Dulski, P., Romer, R.L., Rhede, D.Element and Sr isotope signatures of titanite as indicator of variable fluid composition in hydrated eclogite.Lithos, Vol. 121, 1-4, pp. 12-24.TechnologyMetamorphism
DS201905-1068
2019
Dultsev, V.F.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
DS201906-1339
2019
Dultsev, V.F.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
DS1993-0888
1993
Dulziel, I.W.D.Lawyer, L.A., Dulziel, I.W.D.Antarctic plate: tectonics from a gravity anomly and infrared satelliteimageGsa Today, Vol. 3, No. 6, May pp. 117, 118, 119, 122AntarcticaTectonics, Geophysics -gravity, ice
DS201605-0832
2016
Dumanska-Slowik, M.Dumanska-Slowik, M.Evolution of mariupolite ( nepheline syenite) in the alkaline Oktiabrski Massif ( Ukraine) as the host of potential Nb-Zr-REE mineralization.Ore Geology Reviews, Vol. 78, pp. 1-13.Europe, UkraineMetasomatism

Abstract: Mariupolite, aegirine-albite nepheline syenite, outcropping only in the Oktiabrski massif in south-eastern Ukraine, is a potential resource of Nb, Zr and REE for future exploration and development. Some types of this rock can be also used in ceramics, glass and building industry and jewellery. Mariupolite is composed of (1) magmatic and (2) subsolidus and hydrothermal components. The magmatic assemblage includes zircon, aegirine, nepheline, albite, K-feldspar, pyrochlore, fluorapatite, fluorbritholite-(Ce) and magnetite. Alkaline-carbonate-chloride-rich fluids exsolved very early in the history of the rock, in a late stage of, or directly after, its consolidation, induced intensive high-temperature alteration of the primary mariupolite components resulted in formation of cancrinite, calcite, fluorite, REE-bearing minerals such as monazite, parasite-(Ce), bastnäsite-(Ce), as well as sodalite, natrolite and hematite. The genesis of this peculiar mineralization seems to be associated with multistage magmatic and tectonic activity of the Ukrainian Shield and fluids mediated metasomatic processes.
DS200512-0380
2005
Dumas, P.Guilhaumou, N., Sautter, V., Dumas, P.Synchrotron FTIR microanalysis of volatiles in melt inclusions and exsolved particles in ultramafic deep seated garnets.Chemical Geology, In press.Africa, South AfricaJagersfontein, ultradeep xenoliths, partial melting
DS200712-0379
2007
Dumas, P.Grant, K., Ingrin, J., Lorand, J.P., Dumas, P.Water partitioning between mantle minerals from peridotite xenoliths.Contributions to Mineralogy and Petrology, Vol. 154, 1, pp. 15-34.MantleMineralogy - hydrous phase
DS201903-0542
2019
Dumazer, G.Schmiedel, T., Gailland, O., Haug, O.T., Dumazer, G., Breikreuz, C.Coulomb failure of Earth's brittle crust controls growth, emplacement and shapes of igneous sills, saucer-shaped sills and laccoliths.Earth and Planetary Science Letters, Vol. 510, pp. 161-172.MantleMagmatism

Abstract: Tabular intrusions are common features in the Earth's brittle crust. They exhibit a broad variety of shapes, ranging from thin sheet intrusions (sills, saucer-shaped sills, cone sheets), to more massive intrusions (domed and punched laccoliths, stocks). Such a diversity of intrusion shapes reflects different emplacement mechanisms caused by contrasting host rock and magma rheologies. Most current models of tabular intrusion emplacement assume that the host rock behaves purely elastically, whereas numerous observations show that shear failure plays a major role. In this study, we investigate the effects of the host rock's Coulomb properties on magma emplacement by integrating (1) laboratory models using dry Coulomb granular model hosts of variable strength (cohesion) and (2) limit analysis numerical models. Our results show that both sheet and massive tabular intrusions initiate as a sill, which triggers shear failure of its overburden along an inclined shear damage zone at a critical sill radius, which depends on the emplacement depth and the overburden's cohesion. Two scenarios are then possible: (1) if the cohesion of the overburden is significant, opening of a planar fracture along the precursory weakened shear damage zones to accommodate magma flow, leads to the formation of inclined sheets, or (2) if the cohesion of the overburden is negligible, the sill inflates and lifts up the overburden, which is dissected by several faults that control the growth of a massive intrusion. Finally, we derive a theoretical scaling that predicts the thickness-to-radius aspect ratios of the laboratory sheet intrusions. This theoretical prediction shows how sheet intrusion morphologies are controlled by a mechanical equilibrium between the flowing viscous magma and Coulomb shear failure of the overburden. Our study suggests that the emplacement of sheet and massive tabular intrusions are parts of the same mechanical regime, in which the Coulomb behavior of the Earth's brittle crust plays an essential role.
DS200812-0302
2008
Dumberry, M.Dumberry, M.Gravitational torque on the inner core and decadal polar motion.Geophysical Journal International, Vol. 172, no. 3, March pp. 903-920.MantleCore
DS200812-0303
2008
Dumberry, M.Dumberry, M.Decadal variations in gravity caused by a tilt of the inner core.Geophysical Journal International, Vol. 172, no. 3, March pp. 921-933.MantleCore
DS201012-0174
2010
Dumberry, M.Dumberry, M., Mound, J.Inner core mantle gravitational locking and the super rotation of the inner core.Geophysical Journal International, Vol. 181, 2, pp. 806-817.MantleGeophysics - gravity
DS201112-0291
2011
Dumberry, M.Dumberry, M.A new twist on inner-core spin.Nature Geoscience, Vol. 4, pp. 216-217.MantleGeophysics - seismics
DS201112-0292
2011
Dumberry, M.Dumberry,M.A new twist on inner-core spin. Detection of a shift of the hemispheric boundary that occurred over geological timescales removes the contradiction.Nature Geoscience, Vol. 4, April pp. 216-217.MantleStructure of core
DS201412-0168
2014
Dumberry, M.Davies, C.J., Stegman, D.R., Dumberry, M.The strength of gravitational core mantle coupling.Geophysical Research Letters, Vol. 41, 11, pp. 3786-3792.MantleGeophysics - gravity
DS201412-0169
2014
Dumberry, M.Davies, C.J., Stegman, D.R., Dumberry, M.The strength of gravitational core-mantle coupling.Geophysical Research Letters, Vol. 41, 11, pp. 3786-3792.MantleGeophysics - gravity
DS1991-0409
1991
Dumitru, T.A.Dumitru, T.A., Gans, P.B., Foster, D.A., Miller, E.L.Refrigeration of the western Cordilleran lithosphere during Laramide shallow angle subductionGeology, Vol. 19, No. 11, November pp. 1145-1148CordilleraSubduction, Tectonics
DS201012-0784
2010
Dumka, D.Thalenhorst, H., Dumka, D.Bulk sampling of mineral projects using a sample tower: lessons from the field. ( Strathcona Mineral Services)Canadian Institute of Mining and Metallurgy, Vol. 1, no. 1, pp. 44-54.Canada, NunavutDeposit - Meliadine gold
DS1997-0368
1997
DummettGaranin, V.K., Dummett, Amtauer, Kudryavtseva, FipkeInternal structure and spectroscopic characteristics of diamonds from Lomonosov deposit.Doklady Academy of Sciences, Vol. 353, No. 2, Feb-Mar, pp. 233-5.Russia, Kola PeninsulaDiamond - morphology, Deposit - Lomonosov
DS2002-0623
2002
Dummett, H.Gutnick, J., Dummett, H.Recent diamond discoveries in Nunavut - Tahera's success in the Slave CratonProspectors and Developers Association of Canada (PDAC) 2002, 1p. abstractNorthwest Territories, NunavutExploration, Tahera Corporation
DS1985-0708
1985
Dummett, H.T.Waldman, M.A., Mccandless, T.E., Dummett, H.T.Geology and Mineralogy of the Twin Knobs # 1 Lamproite Pikecounty, Arkansaw #2Geological Society of America (GSA), Vol. 17, No. 3, P. 196. (abstract.).United States, Gulf Coast, Arkansas, PennsylvaniaGeochronology, Evaluation
DS1985-0709
1985
Dummett, H.T.Waldman, M.A., Mccandless, T.E., Dummett, H.T.Geology and Mineralogy of the Twin Knobs # 1 Lamproite Pikecounty, Arkansaw #1Preprint of Paper Presented Geological Society of America (gsa), 17P. 12 FIGS. 1 TABLE.United States, Gulf Coast, Arkansas, PennsylvaniaLamproite, Prospecting, Geophysics, Geochemistry
DS1987-0168
1987
Dummett, H.T.Dummett, H.T., Fipke, C.E., Blusson, S.L.Diamond exploration in the North American Cordillerain: Geoexpo/86, A.E.G. publ, pp. 168-176British ColumbiaDiatremes
DS1987-0777
1987
Dummett, H.T.Waldman, M.A., McCandless, T.E., Dummett, H.T.Geology and petrography of the Twin Knobs # 1 lamproite, Pike County, ArkansawMantle metasomatism and alkaline magmatism, edited E. Mullen Morris and, No. 215, pp. 205-216ArkansasAnalyses p. 212, 214
DS1991-0410
1991
Dummett, H.T.Dummett, H.T.Diamond exploration in North AmericaThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin) ., Session on Diamonds at The Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Annual Meeting April, Vol. 84, No. 947, March p. 90. AbstractCanada, United StatesExploration, Brief overview
DS1992-0401
1992
Dummett, H.T.Dummett, H.T.Letter to editor in response to Griffin's outline of nickel thermometerExplore ( Exploration Geochemist's Newsletter), No. 75, p. 3AustraliaDiamond exploration, Nickel thermometer
DS1994-0470
1994
Dummett, H.T.Dummett, H.T., Fipke, C.E., Moore, R.O.Update on the BHP- DIA MET joint venture diamond project, NorthwestTerritories.The Canadian Institute of Mining, Metallurgy and Petroleum (CIM) District 6, Oct. 11-15th. Vancouver, p.63 abstract plus 4p.Northwest TerritoriesSampling, Deposit -Point Lake
DS1994-1228
1994
Dummett, H.T.Moore, R.O., Fipke, C.E., Dummett, H.T.The BHP Dia Met joint venture diamond project, Northwest Territories, Canada.The Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Section Meeting Oct. 12, Vancouver, 4p.Northwest TerritoriesProject update, Exploration, sampling, geophysics
DS1995-0454
1995
Dummett, H.T.Dummett, H.T.Geology of the Exeter diamond deposits, northwest Territories, CanadaSociety for Mining, Metallurgy and Exploration (SME) Meeting, Denver March 1995, abstractNorthwest TerritoriesDiamond deposits
DS1995-0542
1995
Dummett, H.T.Fipke, C.E., Dummett, H.T., Moore, R.O., Carlson, J.A.History of the discovery of Diamondiferous kimberlites in the Northwest Territories of Canada.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 158-60.Northwest TerritoriesDiscovery -brief overview
DS1996-0393
1996
Dummett, H.T.Dummett, H.T.The development of microanalyses of garnets in chromites for diamond exploration in northwest Territories.Society for Mining, Metallurgy and Exploration (SME)/American Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) PHoenix, Arizona, March 13th., p. 48. AbstractNorthwest TerritoriesDiamond exploration, Microproble
DS1999-0183
1999
Dummett, H.T.Dummett, H.T.Critical elements of exploration successNorth Atlantic Minerals Symposium, Sept. pp. 191-3.GlobalEconomics, success, discoveries, philosophy, Exploration
DS2003-0900
2003
Dummett, H.T.McCandless, T.E., Dummett, H.T.Some aspects of chromian spinel (chromite) chemistry in relation to diamondGeological Association of Canada Annual Meeting, Abstract onlyGlobalGeochemistry
DS200412-1260
2003
Dummett, H.T.McCandless, T.E., Dummett, H.T.Some aspects of chromian spinel (chromite) chemistry in relation to diamond exploration.Geological Association of Canada Annual Meeting, Abstract onlyTechnologyGeochemistry
DS200512-0676
2005
Dumond, G.Mahan, K.H., Williams, M.L., Dumond, G., Card, C.Reconstruction of a large deep crustal terrane: implications for the Snowbird tectonic zone and early growth of Laurentia.GAC Annual Meeting Halifax May 15-19, Abstract 1p.Canada, Alberta, SaskatchewanTrans Hudson Orogen, tectonics
DS201312-0230
2013
Dumond, G.Dumond, G.,Thomas, W.A., Mickus, K.L., Keller, G.R.Resolving geological and geophysical evidence for a reactivated Cambrian plate boundary beneath the Ouachita orogen: the Alabama- Oklahoma transform fault.Geological Society of America, 47th Meeting South central April 4-5, 1/2p. AbstractUnited States, AlabamaLamproite
DS1986-0201
1986
Dumont, J.F.Dumont, J.F.Identification par teledetection de l'accident de la Sanaga(Cameroun) saposition dans le contexte des grands accidentsd'Afrique Centrale et de lalimite noGeodynamique, (in French), Vol.1, No. 1, pp. 13-19GlobalTectonics
DS1993-0380
1993
Dumont, R.Dumont, 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
DS1993-0381
1993
Dumont, R.Dumont, R., Stone, P., Teskey, D.Aeromagnetic survey -Cypress HillsThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin) , Annual Meeting Abstracts approximately 10 lines, Vol. 86, No. 968, March POSTER ABSTRACT p. 69AlbertaGeophysics, Kimberlite pipes
DS1993-1584
1993
Dumont, R.Teskey, D.J., Dumont, R., Stone, P.E., Gibb, R.A.The aeromagnetic survey program of the Geological Society of Canada (GSC)- implications for kimberliteexploration.Mid-continent diamonds Geological Association of Canada (GAC)-Mineralogical Association of Canada (MAC) Symposium ABSTRACT volume, held Edmonton May, pp. 27-30.Northwest TerritoriesGeophysics
DS1994-1102
1994
Dumont, R.Mariano, J., Dumont, R., Ross, G., Teskey, D.Correlations between mantle derived alkaline intrusive rocks and semi-magnetic lineations in southeastern Alberta.Geological Survey of Canada Open Forum January 17-19th. Abstracts only, p. 26, 27.AlbertaGeophysics -magnetics, Alkaline rocks
DS1996-0722
1996
Dumont, R.Keating, P., Tod, J., Dumont, R.The National aeromagnetic databaseGeological Survey of Canada, LeCheminant ed, OF 3228, pp. 229-232.CanadaGeophysics -aeromagnetics
DS1997-0977
1997
Dumont, R.Ross, G.M., Mariano, J., Dumont, R., Kjarsgaard, B., TeskeyWas Eocene magmatism Wide spread in subsurface southern Alberta? evidence from new aeromagnetic anomaly dataGeological Survey of Canada, Bulletin. No. 500, pp. 235-246.AlbertaMagmatism, Archean Medicine Hat Block
DS2001-0276
2001
Dumont, R.Dumont, R., Coyle, M., Potvin, J.High resolution aeromagnetic dataGeological Survey of Canada (GSC) Open File, No. 4029-56. $ 20. eachOntario, northernGeophysics - total field magnetic
DS2001-0277
2001
Dumont, R.Dumont, R., Coyle, M.J., Potvin, J.High resolution aeromagnetic data.. total field. parts of NTS 42 B, G. OGeological Survey of Canada (GSC) Open File, No. 4029-56, 1:50,000 $ 20.00 eachOntarioGeophysics - magnetics, Specific areas - not all Quebec
DS2001-0278
2001
Dumont, R.Dumont, R., Coyle, M.J., Potvin, J.High resolution aeromagnetic data.. first vertical derivative. parts of NTS 42 B, G. OGeological Survey of Canada (GSC) Open File, No. 4057-84, 1:50,000 $ 20.00 eachOntarioGeophysics - magnetics, Specific areas - not all Quebec
DS2001-0279
2001
Dumont, R.Dumont, R., Coyle, M.J., Potvin, J.Aeromagnetic total field map, QuebecGeological Survey of Canada (GSC) Open File, No. 4126-55, 1:50,000 $ 20.00 eachQuebecGeophysics - magnetics, Specific areas - not all Quebec
DS2001-0280
2001
Dumoulin, C.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
Dumoulin, C.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
Dumoulin, C.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
DS200512-0254
2005
Dumoulin, C.Dumoulin, 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
DS201212-0251
2012
Dumoulin, C.Golle, O., Dumoulin, C., Choblet, G., Cadek, O.Topography and geoid induced by a convecting mantle beneath an elastic lithosphere.Geophysical Journal International, in press availableMantleConvection
DS1998-0960
1998
Dumpleton, S.Mather, J., Banks, D., Dumpleton, S., Fermor, M.Groundwater contaminants and their migrationsGeological Society of London Special Publication, No. 128, 320p. $ 115GlobalBook - ad, Groundwater management, hydrogeology
DS1998-0961
1998
Dumpleton, S.Mather, J., Banks, D., Dumpleton, S., Fermor, M.Groundwater contaminants and their migrationGeological Society of London Special Publication, No. 128, 380pGlobalBook - table of contents, Groundwater, environmental
DS1988-0445
1988
Dunaeva, G.V.Matsyuk, S.S., Platonov, A.N., Taran, M.N., Nazarov, Yu.N., Dunaeva, G.V.Optical spectroscopy as an effective investigative method when prospecting for kimberlites.*UKR.Visn. Akad. Nauk UKR. RSR, *UKR., No. 2, pp. 53-59RussiaBlank
DS2001-0444
2001
Dunai, T.J.Hanyu, T., Dunai, T.J., Davies, G.R., Kaneoka, I.Noble gas study of the Reunion hotspot: evidence for distinct less degassed mantle sources.Earth and Planetary Science Letters, Vol. 193, No. 1-2, pp. 83-98.Mauritius, MantleGeochronology, hot spots, degassing
DS200712-0055
2007
Dunai, T.J.Barry, T.L., Ivanov, A.V., Rasskazov, S.V., Demonterova, E.I., Dunai, T.J., Davies, G.R., HarrisonHelium isotopes provide no evidence for deep mantle involvement in Wide spread Cenozoic volcanism across central Asia.Lithos, Vol. 95, 3-4, pp. 415-424.AsiaGeochronology
DS1988-0183
1988
Dunbar, J.A.Dunbar, J.A., Sawyer, D.S.Continental rifting at pre-existing lithospheric weaknessesNature, Vol. 333, No. 6172, June 2, pp. 450-451MidcontinentBlank
DS1989-0376
1989
Dunbar, J.A.Dunbar, J.A., Sawyer, D.S.How preexisting weaknesses control the style of continental breakupJournal of Geophysical Research, Vol. 94, No. B6, June 10, pp. 7278-7292GlobalTectonics, Plate tectonics
DS1975-0002
1975
Duncan, A.R.Ahrens, L.H., Dawson, J.B., Duncan, A.R., Erlank, A.J.First International Conference on Kimberlites Held in Cape Town from 24th to 28th September 1973.Physics And Chemistry of The Earth, New York: Pergamon Press, Vol. 9, 936P.GlobalKimberlite, Kimberley, Janlib
DS1980-0121
1980
Duncan, A.R.Erlank, A.J., Allsopp, H.I., Duncan, A.R., Bristow, J.W.Mantle Heterogeneity Beneath Southern Africa: Evidence From a Volcanic Record.Royal Society of London PHIL. Transactions, Vol. 297, No. 1431, PP. 295-308.South AfricaTectonic
DS1994-1730
1994
Duncan, A.R.Sweeney, R.J., Duncan, A.R., Erlank, A.J.Geochemistry and petrogenesis of central Lebombo basalts of the KarooIgneous ProvinceJournal of Petrology, Vol. 35, pt. 1, pp. 95-125.South Africa, Zimbabwe, Swaziland, LesothoGeochemistry, Magma - basalts
DS1995-0455
1995
Duncan, A.R.Duncan, A.R.A review of South African research on volcanic rocks, related intrusive rocks and mantle derived materialsSouth Afr. Journal of Science, Vol. 91, No. 5, May pp. 255-264South AfricaVolcanics, Alkaline rocks research 1991-5
DS1998-0405
1998
Duncan, A.R.Ewart, A., Milner, S.C., Duncan, A.R.Etendeka, volcanism of the Goboboseb Mountains and Messum Igneous Namibia. Pt. 1. geochemistryJournal of Petrology, Vol. 39, No. 2, pp. 191-NamibiaTristan Plume melts, Early Cretaceous, Crustal contamination - Parana Etendeka
DS1994-0471
1994
Duncan, C.C.Duncan, C.C., Turcotte, D.L.On the breakup and coalescence of continentsGeology, Vol. 22, No. 2, Feberuary pp. 103-106GlobalContinental drift
DS1994-0472
1994
Duncan, C.C.Duncan, C.C., Turcotte, D.L.On the breakup and coalesence of continentsGeology, Vol. 22, No. 2, February pp. 103-106.GlobalGondwana
DS1991-0384
1991
Duncan, D.J.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
DS1991-0675
1991
Duncan, D.J.Harris, J.W., Duncan, D.J., Zhang, F., Mia, Q., Zhu, Y.The physical characteristics and syngenetic inclusion geochemistry Of diamonds from Pipe 50, Liaoning Province, People's Republic of Chin a #1Proceedings of Fifth International Kimberlite Conference held Araxa June, pp. 160-162ChinaDiamond morphology, Peridotite, Diamond inclusions
DS1994-0434
1994
Duncan, D.J.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
DS1994-0721
1994
Duncan, D.J.Harris, J.W., Duncan, D.J., Zhang F., Mia Q, Zhu Y.The physical characteristics and syngenetic inclusion geochemistry Of diamonds from Pipe 50, Lianoning Province #2Proceedings of Fifth International Kimberlite Conference, Vol. 2, pp. 106-115.ChinaDiamond morphology, Geochemistry
DS2001-0086
2001
Duncan, G.Barron, B.J., Barton, L.M., Duncan, G.Garnets, diamonds: diatremes and subduction, Bingara Area, NSWJournal of the Proceedings of the Royal Society of New South Wales, Vol. 134, p.101-2. abstractAustralia, New South WalesBlank
DS200412-0096
2001
Duncan, G.Barron, B.J., Barton, L.M., Duncan, G.Garnets, diamonds: diatremes and subduction, Bingara Area, NSW.Journal of the Proceedings of the Royal Society of New South Wales, Vol. 134, p.101-2. abstractAustralia, New South WalesDiamond - morphology
DS200612-0092
2005
Duncan, G.Barron, B.J., Barron, L.M., Duncan, G.Eclogitic and ultrahigh pressure crustal garnets and their relationship to Phanerozoic subduction diamonds, Bingara area, New England Fold Belt, eastern Australia.Economic Geology, Vol. 100, 8, Dec. pp.AustraliaUHP subduction
DS1992-1345
1992
Duncan, K.Schultz-Ela, D., Duncan, K.Restore Users manual and softwareUniversity of Texas at Austin, $ 249.95 plus postage and handlingGlobalComputer, Program -RESTORE.
DS201707-1320
2017
Duncan, M.S.Duncan, M.S., Dasgupta, R.Rise of Earth's atmospheric oxygen controlled by efficient subduction of organic carbon.Nature Geoscience, Vol. 10, 6, pp. 387-392.Mantlesubduction - carbon

Abstract: The net flux of carbon between the Earth’s interior and exterior, which is critical for redox evolution and planetary habitability, relies heavily on the extent of carbon subduction. While the fate of carbonates during subduction has been studied, little is known about how organic carbon is transferred from the Earth’s surface to the interior, although organic carbon sequestration is related to sources of oxygen in the surface environment. Here we use high pressure–temperature experiments to determine the capacity of rhyolitic melts to carry carbon under graphite-saturated conditions in a subducting slab, and thus to constrain the subduction efficiency of organic carbon, the remnants of life, through time. We use our experimental data and a thermodynamic model of CO2 dissolution in slab melts to quantify organic carbon mobility as a function of slab parameters. We show that the subduction of graphitized organic carbon, and the graphite and diamond formed by reduction of carbonates with depth, remained efficient even in ancient, hotter subduction zones where oxidized carbon subduction probably remained limited. We suggest that immobilization of organic carbon in subduction zones and deep sequestration in the mantle facilitated the rise (~103–5 fold) and maintenance of atmospheric oxygen since the Palaeoproterozoic and is causally linked to the Great Oxidation Event. Our modelling shows that episodic recycling of organic carbon before the Great Oxidation Event may also explain occasional whiffs of atmospheric oxygen observed in the Archaean.
DS201807-1491
2018
Duncan, M.S.Garber, J.M., Maurya, S., Hernandez, J-A., Duncan, M.S., Zeng, Li., Zhang, H.L., Faul, U., McCammon, C., Montagner, J-P., Moresi, L., Romanowicz, B.A., Rudnick, R.L., Stixrude, L.Multidisciplinary constraints on the abundance of diamond and eclogite in the cratonic lithosphere. Mentions Jericho and Roberts VictorGeochemistry, Geophysics, Geosystems, https://doi.org/10.1029/2018GCC007534Globalthermobarometry

Abstract: Some seismic models derived from tomographic studies indicate elevated shear?wave velocities (?4.7 km/s) around 120?150 km depth in cratonic lithospheric mantle. These velocities are higher than those of cratonic peridotites, even assuming a cold cratonic geotherm (i.e., 35 mW/m2 surface heat flux) and accounting for compositional heterogeneity in cratonic peridotite xenoliths and the effects of anelasticity. We reviewed various geophysical and petrologic constraints on the nature of cratonic roots (seismic velocities, lithology/mineralogy, electrical conductivity, and gravity) and explored a range of permissible rock and mineral assemblages that can explain the high seismic velocities. These constraints suggest that diamond and eclogite are the most likely high?Vs candidates to explain the observed velocities, but matching the high shear?wave velocities requires either a large proportion of eclogite (>50 vol.%) or the presence of up to 3 vol.% diamond, with the exact values depending on peridotite and eclogite compositions and the geotherm. Both of these estimates are higher than predicted by observations made on natural samples from kimberlites. However, a combination of ?20 vol.% eclogite and ~2 vol.% diamond may account for high shear?wave velocities, in proportions consistent with multiple geophysical observables, data from natural samples, and within mass balance constraints for global carbon. Our results further show that cratonic thermal structure need not be significantly cooler than determined from xenolith thermobarometry.
DS201808-1745
2018
Duncan, M.S.Garber, J.M., Maurya, S., Hernandez, J-A., Duncan, M.S., Zeng, L., Zhang, H.L., Faul, U., McCammon, C., Montagner, J-P., Moresi, L., Romanowicz, B.A., Rudnick, R.L., Stixrude, L.Multidisciplinary constraints on the abundance of diamond and eclogite in the cratonic lithosphere.G3 Geochemistry, Geophysics, Geosystems, http:/orchid.org/0000-0001-5313-0982Mantleeclogite
DS201809-2024
2018
Duncan, M.S.Garber, J.M., Maurya, S., Hernandez, J.A., Duncan, M.S., Zeng, L., Zhang, H.L.Multidisciplanary constraints on the abundance of diamond and eclogite in the cratonic lithosphere.Geochemistry, Geophysics, Geosystems, Vol. 19, 7, pp. 2062-2086. doi.org/10/1029/ 2018GC007534Mantlegeophysics - seismics

Abstract: Some seismic models derived from tomographic studies indicate elevated shear?wave velocities (?4.7 km/s) around 120-150 km depth in cratonic lithospheric mantle. These velocities are higher than those of cratonic peridotites, even assuming a cold cratonic geotherm (i.e., 35 mW/m2 surface heat flux) and accounting for compositional heterogeneity in cratonic peridotite xenoliths and the effects of anelasticity. We reviewed various geophysical and petrologic constraints on the nature of cratonic roots (seismic velocities, lithology/mineralogy, electrical conductivity, and gravity) and explored a range of permissible rock and mineral assemblages that can explain the high seismic velocities. These constraints suggest that diamond and eclogite are the most likely high?Vs candidates to explain the observed velocities, but matching the high shear?wave velocities requires either a large proportion of eclogite (>50 vol.%) or the presence of up to 3 vol.% diamond, with the exact values depending on peridotite and eclogite compositions and the geotherm. Both of these estimates are higher than predicted by observations made on natural samples from kimberlites. However, a combination of ?20 vol.% eclogite and ~2 vol.% diamond may account for high shear?wave velocities, in proportions consistent with multiple geophysical observables, data from natural samples, and within mass balance constraints for global carbon. Our results further show that cratonic thermal structure need not be significantly cooler than determined from xenolith thermobarometry.
DS202009-1628
2018
Duncan, M.S.Garber, J.M., Maurya, S., Hernandez, J.A., Duncan, M.S., Zeng, L., Zhang, H.L.Multidisciplenary constraints on the abundance of diamond and eclogite in the cratonic lithosphere.Geochemistry, Geophysics, Geosystems, Vol. 19: https://doi.org/10.1029/2018GC007534Mantleeclogite

Abstract: Some seismic models derived from tomographic studies indicate elevated shear?wave velocities (?4.7 km/s) around 120-150 km depth in cratonic lithospheric mantle. These velocities are higher than those of cratonic peridotites, even assuming a cold cratonic geotherm (i.e., 35 mW/m2 surface heat flux) and accounting for compositional heterogeneity in cratonic peridotite xenoliths and the effects of anelasticity. We reviewed various geophysical and petrologic constraints on the nature of cratonic roots (seismic velocities, lithology/mineralogy, electrical conductivity, and gravity) and explored a range of permissible rock and mineral assemblages that can explain the high seismic velocities. These constraints suggest that diamond and eclogite are the most likely high?Vs candidates to explain the observed velocities, but matching the high shear?wave velocities requires either a large proportion of eclogite (>50 vol.%) or the presence of up to 3 vol.% diamond, with the exact values depending on peridotite and eclogite compositions and the geotherm. Both of these estimates are higher than predicted by observations made on natural samples from kimberlites. However, a combination of ?20 vol.% eclogite and ~2 vol.% diamond may account for high shear?wave velocities, in proportions consistent with multiple geophysical observables, data from natural samples, and within mass balance constraints for global carbon. Our results further show that cratonic thermal structure need not be significantly cooler than determined from xenolith thermobarometry.
DS1991-0780
1991
Duncan, R.Jacques, A.L., Knutson, J., Duncan, R.A review of the carbonatites of AustraliaProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 205-207AustraliaMount Weld, Ponton Creek, Cummins Range, Mundine Well, Mud Tank, Redbank, Walloway
DS200512-0066
2005
Duncan, R.Barragn, R., Baby, P., Duncan, R.Cretaceous alkaline intra-plate magmatism in the Ecuadorian Oriente Basin: geochemical, geochronological and tectonic evidence.Earth and Planetary Science Letters, Vol. 236, 3-4, pp. 670-690.South America, EcuadorMagmatism
DS200512-0716
2005
Duncan, R.Melluso, L., Morra, V., Bortsu, P., Tommasini, S., Renna, MR, Duncan, R., Franciosi, L., D'Amelio, F.Geochronology and petrogenesis of the Cretaceous Antampombato Ambatovy Complex and associated dyke swarm, Madagascar.Journal of Petrology, Vol. 46, 10, pp. 1963-1996.Africa, MadagascarGeochronology - dike
DS1975-0731
1978
Duncan, R.A.Duncan, R.A., Hargraves, R.B., Brey, G.P.Age, Palaeomagnetism and Chemistry of Melilite Basalts in The Southern Cape, South Africa.Geology Magazine., Vol. 115, PP. 317-396.South AfricaRelated Rocks, Geochronology, Geochemistry
DS1975-0732
1978
Duncan, R.A.Duncan, R.A., Hargraves, R.B., Grey, G.P.Age, Paleomagnetism and Chemistry of Melilite Basalts in The Southern Cape, South Africa.Geology Magazine (London), Vol. 115, No. 5, PP. 317-327.South AfricaGeochronology, Geochemistry
DS1987-0169
1987
Duncan, R.A.Duncan, R.A., Green, D.H.The geochemistry and petrology of an alkaline lamprophyre sheet intrusion complex on Maio Cape Verde RepublicContributions to Mineralogy and Petrology, Vol. 96, pp. 326-342GlobalMantle genesis, Peridotites
DS1990-1197
1990
Duncan, R.A.Prestvik, T., Barnes, C.G., Sunbdvoll, B., Duncan, R.A.Petrology of Peter I-OY (Peter-I Island), west AntarcticaJournal of Volcanology, Vol. 44, No. 3-4, December pp. 315-338AntarcticaPetrology, Related rocks
DS1991-0411
1991
Duncan, R.A.Duncan, R.A.Ocean drilling and the volcanic record of hotspotsGsa Today, Vol. 1, No. 10, October pp. 213-215, 216, 219GlobalHotspots, Overview
DS1991-0412
1991
Duncan, R.A.Duncan, R.A., Richards, M.A.Hotspots, mantle plumes, flood basalts and true polar wanderReviews of Geophysics, Vol. 29, No. 1, February pp. 31-50GlobalMantle, Hotspots
DS1996-0728
1996
Duncan, R.A.Kerr, A.C., Marriner, G.F., Duncan, R.A.The petrogenesis of Gorgona komatiites, picrites basalts: new field, petrographic and geochem. constraintsLithos, Vol. 37, No. 2/3, April pp. 245-260GlobalKomatiites, Petrography
DS1996-1417
1996
Duncan, R.A.Tejada, M.L.G., Mahoney, J.J., Duncan, R.A., Hawkins, M.P.Age and geochemistry of basement and alkalic rocks of Malaita and SantaIsabel, Solomon Islands, Ontong JavaJournal of Petrology, Vol. 37, No. 2, pp. 361-394.GlobalGeochemistry, Alkaline rocks
DS1998-1418
1998
Duncan, R.A.Storey, M., Duncan, R.A., Laresen, H.C.40 Ar-39 Ar geochronology of the West Greenland Tertiary volcanicprovince.Earth and Planetary Science Letters, Vol. 160, No. 3-4, Aug. 1, pp. 569-586.GreenlandGeochronology, Argon
DS200412-1932
2004
Duncan, R.A.Storey, M., Pedersen, A.K., Stecher, O., Bernstein, S., Larsen, H.C., Larsen, L.M., Baker, Duncan, R.A.Long lived post breakup magmatism along the East Greenland margin: evidence for shallow mantle metasomatism by the Iceland plumeGeology, Vol. 32, 2, Feb. pp. 173-176.Europe, Greenland, IcelandMagmatism
DS200512-0255
2005
Duncan, R.A.Duncan, R.A.Timing and duration of volcanism at large igneous provinces: implications for geodynamics and links to hotspots.Chapman Conference held in Scotland August 28-Sept. 1 2005, 1p. abstractMantleMantle plume
DS1986-0861
1986
Duncan, R.K.Willett, G.C., Duncan, R.K., Rankin, R.A.Geology and economic evaluation of the Mt. Weld carbonatite,Laverton Western Australia #1Proceedings of the Fourth International Kimberlite Conference, Held, No. 16, pp. 97-99AustraliaCarbonatite
DS1989-0377
1989
Duncan, R.K.Duncan, R.K., Willett, G.C.High grade lanthanide and yttrium mineralization in the paleo-regolith Of the Mt. Weld carbonatite, western AustraliaGeological Association of Canada (GAC) Annual Meeting Program Abstracts, Vol. 14, p. A20. (abstract.)AustraliaCarbonatite
DS1989-1628
1989
Duncan, R.K.Willett, G.C., Duncan, R.K., Rankin, R.A.Geology and economic evaluation of the Mt. Weldcarbonatite, Laverton Western Australia #2Geological Society of Australia Inc. Blackwell Scientific Publishing, No. 14, Vol. 2, pp. 1215-1238AustraliaCarbonatite, Mt. Weld
DS201904-0730
2019
Duncombe, J.Duncombe, J.The unsolved mystery of the Earth blobs.EOS, 100, https://doi.org/10.1029/ 2019EO117193Mantletomography

Abstract: Researchers peering into Earth’s interior found two continent-sized structures that upend our picture of the mantle. What could their existence mean for us back on Earth’s surface?
DS202008-1386
2020
Duncombe, J.Duncombe, J.Earth's core is in the hot seat.Eos, 101, doi,org./10.1029 /EO145531 June 24, MantleCore age

Abstract: How old is Earth’s inner core? High-pressure and high-temperature experiments suggest that our planet’s inner furnace may be much younger than expected.
DS202008-1387
2020
Duncombe, J.Duncombe, J.The ticking time bomb of Arctic permafrost.Eos, 101, doi,org./10.1029/EO1414607 June 24, Russiapermafrost

Abstract: Arctic infrastructure is under threat from thawing permafrost.
DS2000-0249
2000
Dundon, P.J.Dundon, P.J.The impact of environmental issues on the definition of ore reservesMin. Res. Ore Res. Est. AusIMM Guide, Mon. 23, pp. 395-402.AustraliaEconomics - geostatistics, ore reserves, exploration, Not specific to diamonds
DS1982-0432
1982
Dungan, M.Menzies, M.A., Kempton, P., Dungan, M.Nature of the Continental Mantle Below the Geronimo Volcanic Field Arizona, United States (us)Proceedings of Third International Kimberlite Conference, TERRA COGNITA, ABSTRACT VOLUME., Vol. 2, No. 3, PP. 230-231, (abstract.).ArizonaKimberlite, Rare Earth Elements (ree), Rocky Mountains
DS1985-0439
1985
Dungan, M.Menzies, M., Kempton, P., Dungan, M.Interaction of Continental Lithosphere and Asthenosphere Melts Below the Geronimo Volcanic Field, Arizona UsaJournal of PETROLOGY, Vol. 26, No. 3, AUGUST PP. 663-693.United States, Colorado Plateau, ArizonaMantle Evolution
DS200812-0321
2008
Dungan, M.Erdmann, S., Scaillet, B., Dungan, M.Zoning in olivine xenocryst in hydrous systems.Goldschmidt Conference 2008, Abstract p.A245.MantleZoning patterns
DS1982-0323
1982
Dungan, M.A.Kempton, P.D., Dungan, M.A., Menzies, M.A.Petrology and Geochemistry of Ultramafic Xenoliths from The geronimo Volcanic FieldProceedings of Third International Kimberlite Conference, TERRA, Vol. 2, No. 3, P. 222, (abstract.).United States, Arizona, Colorado PlateauBlank
DS1984-0399
1984
Dungan, M.A.Kempton, P.D., Menzies, M.A., Dungan, M.A.Petrography, Petrology and Geochemistry of Xenoliths and Megacrysts from the Geronimo Volcanic Field, Southeastern Arizona.Proceedings of Third International Kimberlite Conference, Vol. 2, PP. 71-83.United States, Colorado Plateau, ArizonaHarzburgite, Lherzolite, Rare Earth Elements (ree), Websterite, Wehrlite, Mineral Chemistry
DS1987-0343
1987
Dungan, M.A.Kempton, P.D., Dungan, M.A., Blanchard, D.P.Petrology and geochemistry of xenolith bearing alkalic basalts from The geronimo Volcanic field, southeast Arizona, evidence for polybaric fractionation and implicatMantle metasomatism and alkaline magmatism, edited E. Mullen Morris and, No. 215, pp. 347-370ArizonaAnalyses p. 356-7-8
DS1989-0378
1989
Dungan, M.A.Dungan, M.A., Colucci, M.T., Ferguson, K.M., Balsley, S.D.A comparison of dominantly andesitic pre-rift volcanism to dominantlyNew Mexico Bureau of Mines Bulletin., Continental Magmatism Abstract Volume, Held, Bulletin. No. 131, p. 78 Abstract held June 25-July 1New MexicoTectonics, Rifts
DS1993-1811
1993
Dungan, M.A.Zhang, M., Suddaby, P., Thompson, R.N., Dungan, M.A.The origins of contrasting zoning patterns in hyalophane from olivineleucitites, northeast China.Mineralogical Magazine, Vol. 57, No. 389, December pp. 565-573.ChinaLeucite, Mineralogy
DS1993-1812
1993
Dungan, M.A.Zhang, M., Suddaby, P., Thompson, R.N., Dungan, M.A.Barian titanian phlogopite from potassic lavas in northeast China:chemistry, substitutions and paragenesis.American Mineralogist, Vol. 78, No. 9, 10, September-October pp. 1056-1065.ChinaLeucitites
DS2002-0329
2002
Dungan, M.A.Costa, P., Dungan, M.A., Singer, B.S.Hornblende and phlogopite bearing gabbroic xenoliths from Volcan San Pedro... evidence for melt and fluid..Journal of Petrology, Vol. 43, No. 2, pp. 219-42.Chile, AndesMigration, reactions subducted related plutons
DS1997-0295
1997
Dungan, P.Dungan, P.Rock solid: the impact of the mining and primary metals industries on the Canadian economyUniversity of Toronto Institute for Policy Analysis, 220p. $ 25.00CanadaEconomics - mining industry, Book - table of contents
DS2000-0441
2000
Duning, G.R.James, D.T., Duning, G.R.uranium-lead (U-Pb) geochronological constraints for Paleoproterozoic evolution of the Core Zone, southeastern Churchill ProvPrecambrian Research, Vol. 103, No. 1-2, Sept. pp. 31-54.Saskatchewan, Manitoba, Western CanadaGeochronology, Churchill Province
DS1997-0995
1997
Dunitz, J.D.Sarma, J.A.R.O., Nangia, A., Dunitz, J.D.Even odder carbonsNature, Vol. 387, No. 6632, May 29, pp. 464-65.GlobalCarbon, Mineralogy
DS201708-1572
2017
Dunkl, I.Hueck, M., Oriolo, S., Dunkl, I., Wemmer, K., Oyhantcabal, P., Schanofski, M., Stipp Basei, M.A., Siegesmund, S.Phanerozoic low temperature evolution of the Uruguayan shield along the South American passive margin.Journal of the Geological Society, Vol. 174, pp. 609-626.South America, Uruguaymagmatism

Abstract: The crystalline basement of Uruguay was assembled during the Brasiliano Orogeny in the Neoproterozoic Era and was later affected by discrete tectonic activity. A new multi-method low-temperature dataset including (U–Th)/He ages from both zircon and apatite, T–t modelling and K–Ar dating of fine sericite fractions and fault gouge reveal a detailed post-orogenic geological history spanning the Phanerozoic Eon. The juxtaposition of the terranes that compose the area was achieved in the Ediacaran Period, and post-collision was marked by intense exhumation, in which the crystalline basement reached near-surface conditions by the early to mid-Palaeozoic. Regional subsidence promoted sedimentation in the Paraná Basin until the Permian, covering and reheating much of the basement that is at present exposed. Afterwards, deposition and volcanism were mostly confined to its current limits. Regional exhumation of the shield during the Permo-Triassic exposed much of the northern portion of the basement, and the south was further affected by the opening of the South Atlantic Ocean during the Mesozoic. Little exhumation affected the Uruguayan Shield during the Cenozoic, as reflected in its modest topography. The reactivation of inherited Neoproterozoic structures influenced the development of Mesozoic basins and the present-day landscape.
DS202102-0182
2020
Dunkl, I.Dunkl, I. Comparability of heavy mineral data - the first interlaboratory round robin. *** authors cited are too many + 50 more Not specific to diamondsEarth-Science Reviews, Vol. 211, doi.org/ 10.1016/ j.earscirev.2020 .103210 27p. Pdf Globalmineralogy - data

Abstract: Heavy minerals are typically rare but important components of siliciclastic sediments and rocks. Their abundance, proportions, and variability carry valuable information on source rocks, climatic, environmental and transport conditions between source to sink, and diagenetic processes. They are important for practical purposes such as prospecting for mineral resources or the correlation and interpretation of geologic reservoirs. Despite the extensive use of heavy mineral analysis in sedimentary petrography and quite diverse methods for quantifying heavy mineral assemblages, there has never been a systematic comparison of results obtained by different methods and/or operators. This study provides the first interlaboratory test of heavy mineral analysis. Two synthetic heavy mineral samples were prepared with considerably contrasting compositions intended to resemble natural samples. The contributors were requested to provide (i) metadata describing methods, measurement conditions and experience of the operators and (ii) results tables with mineral species and grain counts. One hundred thirty analyses of the two samples were performed by 67 contributors, encompassing both classical microscopic analyses and data obtained by emerging automated techniques based on electron-beam chemical analysis or Raman spectroscopy. Because relatively low numbers of mineral counts (N) are typical for optical analyses while automated techniques allow for high N, the results vary considerably with respect to the Poisson uncertainty of the counting statistics. Therefore, standard methods used in evaluation of round robin tests are not feasible. In our case the ‘true’ compositions of the test samples are not known. Three methods have been applied to determine possible reference values: (i) the initially measured weight percentages, (ii) calculation of grain percentages using estimates of grain volumes and densities, and (iii) the best-match average calculated from the most reliable analyses following multiple, pragmatic and robust criteria. The range of these three values is taken as best approximation of the ‘true’ composition. The reported grain percentages were evaluated according to (i) their overall scatter relative to the most likely composition, (ii) the number of identified components that were part of the test samples, (iii) the total amount of mistakenly identified mineral grains that were actually not added to the samples, and (iv) the number of major components, which match the reference values with 95% confidence. Results indicate that the overall comparability of the analyses is reasonable. However, there are several issues with respect to methods and/or operators. Optical methods yield the poorest results with respect to the scatter of the data. This, however, is not considered inherent to the method as demonstrated by a significant number of optical analyses fulfilling the criteria for the best-match average. Training of the operators is thus considered paramount for optical analyses. Electron-beam methods yield satisfactory results, but problems in the identification of polymorphs and the discrimination of chain silicates are evident. Labs refining their electron-beam results by optical analysis practically tackle this issue. Raman methods yield the best results as indicated by the highest number of major components correctly quantified with 95% confidence and the fact that all laboratories and operators fulfil the criteria for the best-match average. However, a number of problems must be solved before the full potential of the automated high-throughput techniques in heavy mineral analysis can be achieved.
DS2002-0087
2002
Dunkle, S.Ayers, J.C., Dunkle, S., Gao, S., Miller, C.F.Constraints on timing of peak and retrograde metamorphism in the Dabie Shan ultrahigh pressure metamorphic belt, east central China, using U Th PbChemical Geology, Vol.186,2-3, pp.315-31.ChinaUHP, Geochronology - dating of zircon and monazite
DS1998-0130
1998
DunkleyBlack, S., Macdonald, R., Barreiro, Dunkley, SmithOpen system alkaline magmatism in northern Kenya: evidence from U seriesdisequilibration temperatures and radiogenic...Contributions to Mineralogy and Petrology, Vol. 131, No. 4, May pp. 364-378.KenyaGeochronology - isotopes, Alkaline rocks
DS201112-0098
2011
Dunkley, D.J.Bose, S., Dunkley, D.J., Dasgupta, S., Das, K., Arima, M.India-Antarctica-Australia-Laurentia connection in the Paleoproterozoic-Mesoproterozoic revisited: evidence from new zircon U Pb and monzazite chemical age dataGeological Society of America Bulletin, Vol. 123, 9/10 pp. 2031-2049.IndiaEastern Ghats Belt, geochronology
DS201602-0203
2016
Dunkley, D.J.Downes, P.J., Dunkley, D.J., Fletcher, I.R., McNaughton, N.J., Rasmusson, B., Jaques, A.L., Verall, M., Sweetapple, M.T.Zirconolite, zircon and monazite-(Ce) U-Th-Pb age constraints on the emplacement, deformation and alteration history of the Cummins Range carbonatite complex, Halls Creek orogen, Kimberley region, Western Australia.Mineralogy and Petrology, In press available, 24p.AustraliaCarbonatite

Abstract: In situ SHRIMP U-Pb dating of zirconolite in clinopyroxenite from the Cummins Range Carbonatite Complex, situated in the southern Halls Creek Orogen, Kimberley region, Western Australia, has provided a reliable 207Pb/206Pb age of emplacement of 1009 ± 16 Ma. Variably metamict and recrystallised zircons from co-magmatic carbonatites, including a megacryst ~1.5 cm long, gave a range of ages from ~1043-998 Ma, reflecting partial isotopic resetting during post-emplacement deformation and alteration. Monazite-(Ce) in a strongly foliated dolomite carbonatite produced U-Th-Pb dates ranging from ~900-590 Ma. Although the monazite-(Ce) data cannot give any definitive ages, they clearly reflect a long history of hydrothermal alteration/recrystallisation, over at least 300 million years. This is consistent with the apparent resetting of the Rb-Sr and K-Ar isotopic systems by a post-emplacement thermal event at ~900 Ma during the intracratonic Yampi Orogeny. The emplacement of the Cummins Range Carbonatite Complex probably resulted from the reactivation of a deep crustal structure within the Halls Creek Orogen during the amalgamation of Proterozoic Australia with Rodinia over the period ~1000-950 Ma. This may have allowed an alkaline carbonated silicate magma that was parental to the Cummins Range carbonatites, and generated by redox and/or decompression partial melting of the asthenospheric mantle, to ascend from the base of the continental lithosphere along the lithospheric discontinuity constituted by the southern edge of the Halls Creek Orogen. There is no evidence of a link between the emplacement of the Cummins Range Carbonatite Complex and mafic large igneous province magmatism indicative of mantle plume activity. Rather, patterns of Proterozoic alkaline magmatism in the Kimberley Craton may have been controlled by changing plate motions during the Nuna-Rodinia supercontinent cycles (~1200-800 Ma).
DS201704-0634
2017
Dunkley, D.J.Korhonen, F.J., Johnson, S.P., Wingate, M.T.D., Fletcher, I.R., Dunkley, D.J., Roberts, M.P., Sheppard, S., Muhling, J.R., Rasmussen, B.Radiogenic heating and craton-margin plate stresses as drivers for intraplate orogeny.Journal of Metamorphic Geology, in press availableMantleCraton

Abstract: The Proterozoic belts that occur along the margins of the West Australian Craton, as well as those in intraplate settings, generally share similar geological histories that suggest a common plate-margin driver for orogeny. However, the thermal drivers for intraplate orogenesis are generally more poorly understood. The Mutherbukin Tectonic Event records a protracted period of Mesoproterozoic reworking of the Capricorn Orogen and offers significant insight into both the tectonic drivers and heat sources of long-lived intraplate orogens. Mineral assemblages and tectonic fabrics related to this event occur within a 50 km-wide fault-bound corridor in the central part of the Gascoyne Province in Western Australia. This zone preserves a crustal profile, with greenschist facies rocks in the north grading to upper amphibolite facies rocks in the south. The P- T-t evolution of 13 samples from 10 localities across the Mutherbukin Zone is investigated using phase equilibria modelling integrated with in situ U-Pb monazite and zircon geochronology. Garnet chemistry from selected samples is used to further refine the P-T history and shows that the dominant events recorded in this zone are prolonged D1 transpression between c. 1320 and 1270 Ma, followed by D2 transtension from c. 1210 to 1170 Ma. Peak metamorphic conditions in the mid-crust reached >650 °C and 4.4-7 kbar at c. 1210-1200 Ma. Most samples record a single clockwise P-T evolution during this event, although some samples might have experienced multiple perturbations. The heat source for metamorphism was primarily conductive heating of radiogenic mid- and upper crust, derived from earlier crustal differentiation events. This crust was thickened during D1 transpression, although the thermal effects persisted longer than the deformation event. Peak metamorphism was terminated by D2 transtension at c. 1210 Ma, with subsequent cooling driven by thinning of the radiogenic crust. The coincidence of a sedimentary basin acting as a thermal lid and a highly radiogenic mid-crustal batholith restricted to the Mutherbukin Zone accounts for reworking being confined to a discrete crustal corridor. Our results show that radiogenic regions in the shallow to mid crust can elevate the thermal gradient and localize deformation, causing the crust to be more responsive to far-field stresses. The Mutherbukin Tectonic Event in the Capricorn Orogen was synchronous with numerous Mesoproterozoic events around the West Australian Craton, suggesting that thick cratonic roots play an important role in propagating stresses generated at distant plate boundaries.
DS201709-2019
2017
Dunkley, D.J.Kohonen, F.J., Johnson, S.P., Wingate, M.T.D., Kirkland, C.L., Fletcher, I.R., Dunkley, D.J., Roberts, M.P., Sheppard, S., Muhling, J.R., Rasmussen, B.Radiogenic heating and craton margin plate stresses as drivers for intraplate orogeny.Journal of Metamorphic Geology, Vol. 35, 6, pp. 631-661.Mantlegeothermometry

Abstract: The Proterozoic belts that occur along the margins of the West Australian Craton, as well as those in intraplate settings, generally share similar geological histories that suggest a common plate-margin driver for orogeny. However, the thermal drivers for intraplate orogenesis are more poorly understood. The Mutherbukin Tectonic Event records a protracted period of Mesoproterozoic reworking of the Capricorn Orogen and offers significant insight into both the tectonic drivers and heat sources of long-lived intraplate orogens. Mineral assemblages and tectonic fabrics related to this event occur within a 50 km-wide fault-bound corridor in the central part of the Gascoyne Province in Western Australia. This zone preserves a crustal profile, with greenschist facies rocks in the north grading to upper amphibolite facies rocks in the south. The P–T–t evolution of 13 samples from 10 localities across the Mutherbukin Zone is investigated using phase equilibria modelling integrated with in situ U–Pb monazite and zircon geochronology. Garnet chemistry from selected samples is used to further refine the P–T history and shows that the dominant events recorded in this zone are prolonged D1 transpression between c. 1,320 and 1,270 Ma, followed by D2 transtension from c. 1,210 to 1,170 Ma. Peak metamorphic conditions in the mid-crust reached >650°C and 4.4–7 kbar at c. 1,210–1,200 Ma. Most samples record a single clockwise P–T evolution during this event, although some samples might have experienced multiple perturbations. The heat source for metamorphism was primarily conductive heating of radiogenic mid- and upper crust, derived from earlier crustal differentiation events. This crust was thickened during D1 transpression, although the thermal effects persisted longer than the deformation event. Peak metamorphism was terminated by D2 transtension at c. 1,210 Ma, with subsequent cooling driven by thinning of the radiogenic crust. The coincidence of a sedimentary basin acting as a thermal lid and a highly radiogenic mid-crustal batholith restricted to the Mutherbukin Zone accounts for reworking being confined to a discrete crustal corridor. Our results show that radiogenic regions in the shallow to mid crust can elevate the thermal gradient and localize deformation, causing the crust to be more responsive to far-field stresses. The Mutherbukin Tectonic Event in the Capricorn Orogen was synchronous with numerous Mesoproterozoic events around the West Australian Craton, suggesting that thick cratonic roots play an important role in propagating stresses generated at distant plate boundaries.
DS1985-0161
1985
Dunlop, D.J.Dunlop, D.J.Paleomagnetism of Archean rocks from northwestern Ontario: V. Poohbah Lake alkaline complex, Quetico.Canadian Journal of Earth Sciences, Vol. 22, pp. 27-38.OntarioAlkaline Rocks, Deposit - Poohbah
DS1988-0143
1988
Dunlop, D.J.Costanzo-Alvarez, V., Dunlop, D.J.Paleomagnetic evidence for post 2.55 GA tectonic tilting and 1.1 GA reactivation in the southern Kapuskasing zone, Ontario, CanadaJournal of Geophysical Research, Vol. 93, No. B8, August 10, pp. 9126-9136GlobalMidcontinent
DS1993-0281
1993
Dunlop, D.J.Constazo-Alvarez, V., Dunlop, D.J.Paleomagnetism of alkaline complexes and remagnetization in the Kapuskasing structural zone, Ontario, CanadaJournal of Geophysical Research, Vol. 98, No. B3, March 10, pp. 4063-4079OntarioTectonics, Kapuskasing Structural Zone
DS1995-0456
1995
Dunlop, D.J.Dunlop, D.J.Magnetism in rocksJournal of Geophysical Research, Vol. 100, No. B2, Feb. 10, pp. 2161-2174GlobalMagnetism in rocks, Review
DS1995-0457
1995
Dunlop, D.J.Dunlop, D.J.Magnetism in rocksJournal of Geophysical Research, Vol. 100, No. B2, Feb. 10, pp. 2161-2174.MantleMagnetism, Review
DS201012-0175
2010
Dunlop, D.J.Dunlop, D.J., Ozdemir, O.,Costanzo-Alvarez, V.Magnetic properties of rocks of the Kapuskasing uplift ( Ontario, Canada) and origin of long wavelength magnetic anomalies.Geophysical Journal International, Vol. 183, 2, Nov. pp. 645-659.Canada, OntarioGeophysics - not specific to diamonds
DS201412-0214
2014
Dunlop, D.J.Dunlop, D.J.Grenvillia and Laurentia - a Precambrian Wilson cycle?Canadian Journal of Earth Sciences, Vol. 51, pp. 1-10.MantleTectonics
DS201412-0215
2014
Dunlop, D.P.Dunlop, D.P.Grenvillia and Laurentia - a Precambrian Wilson cycle?Canadian Journal of Earth Sciences, Vol. 51, 3, pp. 187-196.Canada, OntarioWilson cycle
DS1985-0189
1985
Dunlop, H.M.Fitton, J.G., Dunlop, H.M.The Cameroon Line, West Africa, and its Bearing on the Origin of Oceanic and Continental Alkali Basalt.Earth Plan. Sci. Letters, Vol. 72, PP. 23-38.West Africa, CameroonTectonics, Geochemistry, Metasomatism, Large-ion Lithophile Elements (lile), Major Element Chemistry
DS202111-1760
2021
Dunlop, J.Bruno, H., Helibron, M., Strachen, R., Fowler, M., de MorrisonValeriano , C., Bersan, S., Moreira, H., Cutts, K., Dunlop, J., Almeida, R., Almeida, J., Storey, C.Earth's new tectonic regime at the dawn of the Paleozoic: Hf isotope evidence for efficient crustal growth and reworking in the Sao Francisco craton, Brazil.Geology, Vol. 49, 10, pp. 1214-1219. pdfSouth America, Brazilcraton

Abstract: A zircon Hf isotope data set from Archean and Paleoproterozoic magmatic and metasedimentary rocks of the southern Săo Francisco craton (Brazil) is interpreted as evidence of accretionary and collisional plate tectonics since at least the Archean-Proterozoic boundary. During the Phanerozoic, accretionary and collisional orogenies are considered the end members of different plate tectonic settings, both involving preexisting stable continental lithosphere and consumption of oceanic crust. However, mechanisms for the formation of continental crust during the Archean and Paleoproterozoic are still debated, with the addition of magmatic rocks to the crust being explained by different geodynamic models. Hf isotopes can be used to quantify the proportion of magmatic addition into the crust: positive ?Hf values are usually interpreted as indications of magmatic input from the mantle, whereas crust-derived rocks show more negative ?Hf. We show that the crust of the amalgamated Paleoproterozoic tectonostratigraphic terranes that make up the southern Săo Francisco craton were generated from different proportions of mantle and crustal isotopic reservoirs. Plate tectonic processes are implied by a consistent sequence of events involving (1) the generation of juvenile subduction-related magmatic arc rocks, followed by (2) collisional orogenesis and remelting of older crust, and (3) post-collisional bimodal magmatism.
DS2001-0185
2001
DunnChiarenzeli, J., Aspler, Dunn, Cousens, Osarko, PowisMulti element and rare earth element composition of lichens, mosses and vascular plants from Barrenlands.Applied Geochem., Vol. 16, No. 2, pp. 245-70.Northwest Territories, NunavutGeochemistry - biochemistry
DS2001-1050
2001
Dunn, C.Seneshen, D., Grunsky, E., Rencz, A., Hall, G., Dunn, C.Geochemical exploration for kimberlites in northern Alberta37th. Forum Industrial Minerals;, May 23-5, pp. 33-4.AlbertaGeochemistry
DS201512-1899
2015
Dunn, C.Bluemel, B., Dunn, C., Hart, C., Leijd, M.Biogeochemical expressions of buried REE mineralization at Norra Karr, southern Sweden.Symposium on critical and strategic materials, British Columbia Geological Survey Paper 2015-3, held Nov. 13-14, pp. 231-240.TechnologyRare earths

Abstract: Biogeochemical exploration is an effective but underutilized method for delineating covered mineralization. Plants are capable of accumulating rare earth elements (REEs) in their tissue, and ferns (pteridophytes) are especially adept because they are one of the most primitive land plants, therefore lack the barrier mechanisms developed by more evolved plants. The Norra Kärr Alkaline Complex, located in southern Sweden approximately 300km southwest of Stockholm, is a peralkaline nepheline syenite enriched in heavy rare earth elements (HREEs). The deposit, roughly 300m wide, 1300m long, and overlain by up to 4 m of Quaternary sediments, has been well-defined by diamond drilling. The inferred REE mineral resource, over 60 million tonnes averaging 0.54% Total Rare Earth Oxide (TREO), is dominantly hosted within the pegmatitic “grennaite” unit, a eudialyte-catapleiite-aegerine nepheline syenite. Vegetation and soil samples were collected from the surficial environment above Norra Kärr to address four key questions: which plant species is the most effective biogeochemical exploration medium; what are the annual and seasonal REE variations in that plant; how do the REEs move through the soil profile; and into which part of the plant are they concentrated. Athyrium filix-femina (lady fern) has the highest concentration of LREEs and HREEs (up to 125.17ppm Ce and 1.03ppm Dy) in its dry leaves; however, there is better contrast between background and anomalous areas in Dryopteris filix-mas (wood fern), which makes it the preferred biogeochemical sampling medium. The REE content in all fern species was shown to decrease from root > frond > stem, and chondrite normalized REE patterns within the plant displayed preferential fractionation of the LREEs in the fronds relative to the roots. Samples collected from an area directly overlying the deposit had up to five times greater HREE content (0.74ppm Dy) in August than the same plants did in June (0.14ppm Dy). The elevated REE content and distinct contrast to background demonstrate that biogeochemical sampling is an effective method for REE exploration in this environment.
DS1989-0379
1989
Dunn, C.E.Dunn, C.E.The Sturgeon Lake kimberlite- an investigation into the geochemical response exhibited by organic samplemediaSaskatchewan Geological Survey Summary of Investigations for 1989, Report No. 89-4, pp. 172-180SaskatchewanGeochemistry, Sturgeon Lake area
DS1993-0382
1993
Dunn, C.E.Dunn, C.E.Diamondiferous kimberlite in Saskatchewan, Canada- a biogeochemical SOURCE[ Journal of Geochemical Exploration,Special issue Proceedings of geochemical Exploration 1991 held RenoJournal of Geochemical Exploration, Special issue Proceedings of, Vol. 47, No. 1-3, pp. 131-142SaskatchewanKimberlite, Geochemistry
DS1995-0458
1995
Dunn, C.E.Dunn, C.E.Introduction to biogeochemical prospectingBiological systems in mineral exploration and processing, pp. 233-242GlobalGeochemistry, Biogeochemistry -prospecting techniques
DS1995-0459
1995
Dunn, C.E.Dunn, C.E.A field guide to biogeochemical prospectingBiological systems in mineral exploration and processing, pp. 345-369GlobalGeochemistry, Biogeochemistry -prospecting techniques
DS1995-0460
1995
Dunn, C.E.Dunn, C.E.Mineral exploration beneath temporate forests: the information supplied bytreesExploration and Mining Geology (The Canadian Institute of Mining, Metallurgy and Petroleum (CIM)), Vol. 4, No. 3, July pp. 197-204SaskatchewanGeochemistry, geobotany, Exploration -plants
DS1995-0461
1995
Dunn, C.E.Dunn, C.E.Biogeochemical prospecting for metalsBiological systems in mineral exploration and processing, pp. 371-425Saskatchewan, Nova Scotia, British ColumbiaGeochemistry, Biogeochemistry -prospecting metals
DS1995-1201
1995
Dunn, C.E.McClenaghan, M.B., Dunn, C.E.Biogeochemical survey over kimberlites in the Kirkland Lake area northeastern Ontario.Geological Survey of Canada, Open File 3005Ontario, Kirkland LakeGeochemistry -biogeochemistry, Kimberlites
DS1996-0394
1996
Dunn, C.E.Dunn, C.E., McClenaghan, M.B.Biogeochemical studies of kimberlitesGeological Survey of Canada, LeCheminant ed, OF 3228, pp. 219-223.Saskatchewan, OntarioBiogeochemistry, Mineral sampling -indicators
DS2001-0282
2001
Dunn, C.E.Dunn, C.E., Smith, D., Kerr, D.E.Biogeochemical survey of the Drybones area, NTS 85 I/4, using outer bark of Black Spruce.Geological Survey of Canada (GSC) Open File, D3991, 1 CD, $ 52.Northwest TerritoriesBiogeochemistry - not specific to diamonds
DS201112-0964
2011
Dunn, C.E.Simandl, G.J., Fajber, R., Dunn, C.E.Biogeochemical footprint of the Ta and Nb bearing carbonatite Blue River area, British Columbia, Canada.Goldschmidt Conference 2011, abstract p.1877.Canada, British ColumbiaCarbonatite
DS201112-0965
2011
Dunn, C.E.Simandl, G.J., Fajber, R., Dunn, C.E., Ulry, B., Dahrouge, J.Biogeochemical exploration vectors in search of carbonatite, Blue River British Columbia.British Columbia Geological Survey, BCGS GeoFile, 2011-05.Canada, British ColumbiaCarbonatite
DS2000-0250
2000
Dunn, D.Dunn, D., Smith, D., McDowell, F.W., Bergman, S.C.Mantle and crustal xenoliths from the Prairie Creek lamproite province, Arkansas.Geological Society of America (GSA) Abstracts, Vol. 32, No. 7, p.A-386.ArkansasXenoliths, Deposit - Black Lick, Twin Knobs
DS2003-0355
2003
Dunn, D.Dunn, D.Diamond evaluation of the Prairie Creek lamproite province, Arkansas, USA8 Ikc Www.venuewest.com/8ikc/program.htm, Session 8, POSTER abstractArkansasDeposit - Prairie Creek
DS2003-0356
2003
Dunn, D.Dunn, D., Smith, D., Bergman, S.C.Mantle xenoliths from the Prairie Creek lamproite province, Arkansas, USA8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, AbstractArkansasMantle petrology, Deposit - Prairie Creek
DS200412-0490
2003
Dunn, D.Dunn, D.Diamond evaluation of the Prairie Creek lamproite province, Arkansas, USA.8 IKC Program, Session 8, POSTER abstractUnited States, ArkansasDiamond exploration
DS200412-0491
2003
Dunn, D.Dunn, D., Smith, D., Bergman, S.C.Mantle xenoliths from the Prairie Creek lamproite province, Arkansas, USA.8 IKC Program, Session 6, AbstractUnited States, ArkansasMantle petrology Deposit - Prairie Creek
DS201112-0388
2011
Dunn, D.Griffin, W.L., Begg, G.C., Dunn, D., O'Reilly, S.Y., Natapov, L.M., Karlstrom, K.Archean lithospheric mantle beneath Arkansas: continental growth by microcontinent accretion.Geological Society of America Bulletin, Vol. 123, 9-10, pp. 1763-1775.United States, ArkansasPrairie Creek lamproites
DS201112-0389
2011
Dunn, D.Griffin, W.L., Begg, G.C., Dunn, D., O'Reilly, S.Y., Natapov, L.M., Karlstrom, K.Archean lithospheric mantle beneath Arkansas: continental growth by microcontinent accretion.Geological Society of America Bulletin, Vol. 123, 9/10 pp. 1763-1775.United States, ArkansasPrairie Creek lamproites
DS1985-0062
1985
Dunn, D.P.Bergman, S.C., Dunn, D.P., Krol, L.G.Petrology and Geochemistry of the Linhaisai Minette, Karamuriver, Central Kalimantan.Geological Association of Canada (GAC)., Vol. 10, P. A4, (abstract.).Kalimantan, BorneoBlank
DS1987-0048
1987
Dunn, D.P.Bergman, S.C., Dunn, D.P., Krol, L.G.Petrology of the Linhaisai minette, central Kalimantan, IndonesiaCanadian Mineralogist, In pressIndonesiaMinette
DS1988-0053
1988
Dunn, D.P.Bergman, S.C., Dunn, D.P., Krol., L.G.Rock and mineral chemistry of the Linhaisai minette, centralIndonesia, and the origin of the Borneo diamondsCanadian Mineralogist, Vol. 26, No. 1, March pp. 23-43GlobalBlank
DS2003-0357
2003
Dunn, D.P.Dunn, D.P.Diamond economics of the Prairie Creek lamproite, Murfreesboro, Arkansas, USAOre Geology Reviews, Vol. 22, 3-4, March pp. 251-262.ArkansasEconomics - erosion model, history, grades, Deposit - Prairie Creek
DS200812-0304
2008
Dunn, D.P.Dunn, D.P.Arkansas crustal xenoliths: implications for basement rocks of the northern Gulf Coast.Geological Society of America South Central Section, March 30, abstractUnited States, ArkansasXenoliths
DS200912-0192
2009
Dunn, D.P.Dunn, D.P.Arkansas crustal xenoliths: implications for basement rocks of the northern Gulf Coast, USA.Lithosphere, Vol. 1, no. 1, pp. 60-64.United States, ArkansasPetrology
DS1860-0139
1871
Dunn, E.J.Dunn, E.J.Notes on the Rocks and Minerals of the Owens District. Report of Mining Surveyors and Registrars.Victoria: Department of Mines, Appendix A., AustraliaDiamond Occurrence
DS1860-0140
1871
Dunn, E.J.Dunn, E.J.Notes on the Diamond Fields Vaal River DutoitspanCape Town: Saul Solomon., 20P.Africa, South Africa, Cape ProvinceGeology
DS1860-0228
1874
Dunn, E.J.Dunn, E.J.On the Mode of Occurrence of Diamonds in South Africa Sheitfontein Quarterly Journal of Geological Society (London), Vol. 30, PP. 54-60. ALSO: Geology Magazine (London), Dec. 2, Vol.Africa, South Africa, Cape ProvinceRegional Geology
DS1860-0276
1877
Dunn, E.J.Dunn, E.J.Further Notes on the Diamond Fields of South AfricaQuarterly Journal of Geological Society (London), Vol. 33, PP. 879-883.Africa, South Africa, Cape ProvinceGeology
DS1860-0363
1881
Dunn, E.J.Dunn, E.J.Notes on the Diamond Fields, South AfricaQuarterly Journal of Geological Society (London), Vol. 37, PP. 609-612. ALSO: Geology Magazine (London), Dec. 2, VOLAfrica, South Africa, Cape ProvinceGeology
DS1910-0346
1913
Dunn, E.J.Dunn, E.J.The Woolshed Valley, BeechworthVictoria Geological Survey Bulletin., No. 25Australia, VictoriaDiamond Occurrence
DS1910-0554
1918
Dunn, E.J.Dunn, E.J.The Discovery of Diamonds in South AfricaIndustrial Australian And Mining Standard., JULY 18TH. PP. 91-92.South AfricaHistory
DS1920-0439
1929
Dunn, E.J.Dunn, E.J.The Geological Map of South AfricaGeology Magazine (London), Vol. 63, PP. 289-292.South AfricaGeology
DS1920-0440
1929
Dunn, E.J.Dunn, E.J.Diamonds in South Africa; 1929Geology Magazine (London), Vol. 66, PP. 334-336.South AfricaHistory
DS1994-1701
1994
Dunn, P.G.Stone, J.G., Dunn, P.G.Ore reserve estimates in the real worldSociety of Economic Geologists, Special Publication No. 3, 150pGlobalOre reserves, Table of contents
DS201412-0412
2014
Dunn, R.L.A.Ito, G., Dunn, R.L.A., Wolfe, C.J., Gallego, A., Fu, Y.Seismic anisotropy and shear wave splitting associated with mantle plume-plate interactions.Journal of Geophysical Research, Vol. 119, no. 6, pp. 4923-4937.MantleGeophysics - seismics
DS1992-1367
1992
Dunn, T.Sen, G., Dunn, T.Preliminary results of mantle metasomatism experimentsEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p.335-6MantleExperimental petrology, Metasomatism
DS1993-0797
1993
Dunn, T.Kelemen, P.B., Shimizu, N., Dunn, T.Relative depletion of niobium in some arc magmas and the continental crust:partitioning of K, Nb, La, and Ce during melt/rock reaction in the uppermantleEarth and Planetary Science Letters, Vol. 120, No. 3/4 December pp. 111-134MantleMelt rock interaction, potassium, lanthanum, cerium
DS1995-1705
1995
Dunn, T.Sen, C., Dunn, T.Experimental model metasomatism of a spinel lherzolite and production of amphibole bearing peridotite.Contributions to Mineralogy and Petrology, Vol. 119, No. 4, April pp. 422-432.New MexicoKilbourne Hole, experimental petrology, Peridotites
DS1996-0948
1996
Dunne, T.Mertes, L.A.K., Dunne, T., Martinelli, L.A.Channel floodplain geomorphology along the Solinoes Amazon River, BrasilGeological Society of America (GSA) Bulletin., Vol. 108, No. 9, Sept. pp. 1089-1107.BrazilGeomorphology, Alluvials - not specific to diamonds
DS200812-0239
2008
Dunne, T.Constantine, J.A., Dunne, T.Meander cutoff and the controls on the production of oxbow lakes. ( not specific to diamonds)Geology, Vol. 36, 1, pp. 23-26.GlobalGeomorphology
DS201705-0837
2017
Dunnell, K.Jaszczak, J.A., Dunnell, K.The Magnificent Mineralogy of Diamond.lithographie.org, No. 19, pp. 24-35.TechnologyBook - mineralogy
DS1997-0296
1997
Dunnigan, G.M.Dunnigan, G.M., Hammen, J.L., Harris, T.R.A SAS-IML program for implementing two phase regression analysis of geophysical time series dataComputers and Geosciences, Vol. 23, No. 7, pp. 763-770GlobalComputers, Program - SAS-IML
DS1987-0379
1987
DunningKrogh, T.E., Corfu, F., Davis, Dunning, Heaman, NakamuraPrecise uranium-lead (U-Pb) isotopic ages of diabase dikes and mafic to ultramafic rocks using trace amounts of baddeleyiteHalls and Fahrig, Geological Association of Canada (GAC) Special Vol., No. 34, pp. 147-52.Quebec, Ontario, Manitoba, Northwest TerritoriesGeochronology
DS1997-0533
1997
Dunning, G.Indares, A., Dunning, G.Coronitic metagabbro and eclogite from the Grenville province westernQuebec: geochronology ...Canadian Journal of Earth Sciences, Vol. 34, pp. 891-904.Quebec, Labrador, Ungavametamorphism
DS1998-0653
1998
Dunning, G.Indares, A., Dunning, G., Cox, R., Gale, D.high pressure high temperature rocks from the base of thick continentalcrust: Manicouagan imbricate zone.Tectonics, Vol. 17, No. 3, June pp. 426-40.Quebec, Labrador, Ungavametamorphism
DS2000-0430
2000
Dunning, G.Indares, A., Dunning, G., Cox, R.Tectono-thermal evolution of deep crust in a Mesoproterozoic continental collision setting....Canadian Journal of Earth Sciences, Vol.37, No.2-3, Feb.Mar, pp.325-40.QuebecGeothermometry, Tectonics - Manicouagan
DS202109-1469
2021
Dunning, G.Good, D.J., Hollings, P., Dunning, G., Epstein, R., McBride, J., Jedemann, A., Magnus, S., Bohav, T., Shore, G.A new model for the Coldwell Complex and associated dykes of the Midcontinent Rift, Canada.Journal of Petrology, Vol. 62, 7, 10.1093/petrology/ega036Canadadeposit - Coldwell

Abstract: Mafic intrusions on the NE shoulder of the Midcontinent Rift (Keweenawan LIP), including Cu-PGE mineralized gabbros within the Coldwell Complex (CC), and rift parallel or radial dykes outside the CC are correlated based on characteristic trace element patterns. In the Coldwell Complex, mafic rocks are subdivided into four groups: (1) early metabasalt; (2) Marathon Series; (3) Layered Series; (4) Geordie-Wolfcamp Series. The Marathon Series are correlated with the rift radial Abitibi dykes (1140?Ma), and the Geordie-Wolfcamp Series with the rift parallel Pukaskwa and Copper Island dykes. U-Pb ages determined for five gabbros from the Layered and Marathon Series are between 1107•7 and 1106•0?Ma. Radiogenic isotope ratios show near chondritic (CHUR) ?Nd(1106?Ma) and 87Sr/86Sri values that range from -0•38 to +1•13 and 0•702537 to 0•703944, respectively. Distinctive geochemical properties of the Marathon Series and Abitibi dykes, such as Ba/La (14-37), Th/Nb (0•06-0•12), La/Sm (3•8-7•7), Sr/Nd (21-96) and Zr/Sm (9-19), are very different from those of the Geordie-Wolfcamp Series and a subset of Copper Island and Pukaskwa dykes with Ba/La (8•7-11), Th/Nb (0•12-0•13), La/Sm (6•7-7•9), Sr/Nd (5-7•8) and Zr/Sm (18-24). Each unit exhibits covariation between incompatible element ratios such as Zr/Sm and Nb/La or Gd/Yb, Sr/Nd and Ba/La, and Nb/Y and Zr/Y, which are consistent with mixing relationship between two or more mantle domains. These characteristics are unlike those of intrusions on the NW shoulder of the MCR, but resemble those of mafic rocks occurring in the East Kenya Rift. The results imply that an unusual and long-lived mantle source was present in the NE MCR for at least 34?Myr (spanning the 1140?Ma Abitibi dykes and the 1106?Ma Marathon series) and indicate potential for Cu-PGE mineralization in an area much larger than was previously recognized.
DS1987-0378
1987
Dunning, G.R.Krogh, T.E., Corfu, F., Davis, D.W., Dunning, G.R., Heaman, L.M.Precise uranium-lead (U-Pb) (U-Pb) ages of diabase dykes and mafic to ultramafic rocks usingGeological Association of Canada (GAC) Special Paper, No. 34, p. 151QuebecIle Bizard kimberlite brief mention
DS1991-0791
1991
Dunning, G.R.Jenner, G.A., Dunning, G.R., Malpas, J., Brown, M., Brace, T.Bay of Islands and Little Port complexes, revisited: age, geochemical and isotopic evidence confirm suprasubduction-zone originCanadian Journal of Earth Sciences, Vol. 28, No. 10, October pp. 1635-1652NewfoundlandOphiolites, Geochronology
DS1997-0595
1997
Dunning, G.R.Ketcheum, J.W.F., Culshawm N.G., Dunning, G.R.uranium-lead (U-Pb) geochronology constraints on Paleoproterozoic orogenesis in the Makkovik Province, labrador.Canadian Journal of Earth Sciences, Vol. 34, pp. 1072-88.Quebec, Labrador, Ungavageochronoloyg, Makkovik Province
DS2000-0442
2000
Dunning, G.R.James, D.T., Dunning, G.R., Fairchild, T.R.Proterozoic microfossils from subsurface siliclastic rocks of the Sao Francico Craton, south central Brasil.Precambrian Research, Vol. 103, No. 1-2, Sept.pp. 31-54.Brazil, south centralCraton - Sao Francisco
DS2002-0340
2002
Dunning, G.R.Crowley, J.L., Myers, J.S., Dunning, G.R.Timing and nature of multiple 3700-3600 Ma tectonic events in intrusive rocks north of the Isua greenstone belt, southern West Greenland.Geological Society of America Bulletin, Vol. 114,10,Oct. pp. 1311-25.GreenlandTectonics
DS2003-1135
2003
Dunning, G.R.Rawlings Hinchey, A.M., Sylvester, P.J., Meyers, J.S., Dunning, G.R., Kosler, J.Paleoproterozoic crustal genesis: calc-alkaline magmatism of the Torngat OrogenPrecambrian Research, Vol. 125, 1-2, pp. 55-85.Labrador, QuebecMagmatism
DS200412-1635
2003
Dunning, G.R.Rawlings Hinchey, A.M., Sylvester, P.J., Meyers, J.S., Dunning, G.R., Kosler, J.Paleoproterozoic crustal genesis: calc-alkaline magmatism of the Torngat Orogen, Voisey's Bay area, Labrador.Precambrian Research, Vol. 125, 1-2, pp. 55-85.Canada, Quebec, LabradorTectonics Magmatism
DS1995-0462
1995
Dunphy, J.M.Dunphy, J.M., Ludden, J.N., Francis, D.Geochemistry of mafic magmas from the Ungava orogen : implications for mantle reservoir compositions at 2.OGaChemical Geology, Vol. 120, pp. 361-380Quebec, Labrador, UngavaGeochemistry, Proterozoic mobile belts
DS1995-0463
1995
Dunphy, J.M.Dunphy, J.M., Ludden, J.N., Parrish, R.R.Stitching together the Ungava Orogen: geochronological TIMS ICP-MS and geochemical constraints -Canadian Journal of Earth Sciences, Vol. 32, pp. 2115-27.Quebec, Labrador, UngavaMagmatic events
DS200412-0023
2004
Dunphy, J.M.Alvin, M.P., Dunphy, J.M., Groves, D.I.Nature and genesis of a carbonatite associated fluorite deposit at Speewash, East Kimberley region, western Australia.Mineralogy and Petrology, Vol. 80, 3-4, March pp. 127-153.AustraliaCarbonatite
DS202012-2223
2020
Dunsby, C.Jones, D.C., Kumar, S., Lanigan, P.M.P., McGuiness, C.D., Dale, M.W., Twichen, D.J., Fisher, D., Martineau, P.M., Neil, M.A., Dunsby, C., French, P.M.W.Multidemensional luminescence microscope for imaging defect colour centres in diamond.Methods and Applications in Flouresence, Vol. 8, 1, 01404 htpp:dx.doi.org/10.1088/2050-6120/ab4eacGloballuminescence

Abstract: We report a multidimensional luminescence microscope providing hyperspectral imaging and time-resolved (luminescence lifetime) imaging for the study of luminescent diamond defects. The instrument includes crossed-polariser white light transmission microscopy to reveal any birefringence that would indicate strain in the diamond lattice. We demonstrate the application of this new instrument to detect defects in natural and synthetic diamonds including N3, nitrogen and silicon vacancies. Hyperspectral imaging provides contrast that is not apparent in conventional intensity images and the luminescence lifetime provides further contrast.
DS1900-0115
1902
Dunstan, B.Dunstan, B.Report on the Sapphire Fields of Anakie, QueenslandQueensland Geological Survey Records For 1901, P. 9; PP. 19-20, PLATE 2, FIG. 10.Australia, QueenslandDiamond, Boliuma Creek
DS1992-1678
1992
Dunsworth, E.A.Wilson, M., Rosenbaum, J.M., Dunsworth, E.A., Larsen, G.Are melillitites partial melts of the thermal boundary layer?Eos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p.325Europe, GermanyUpper Rhinegraben Volcanic Province, Melillitite
DS2002-1126
2002
DunworthNeumann, E.R., Dunworth, Sundvolt, TollefsrudB1 basaltic lavas in Vestfold Jeloya area, central Oslo rift: derivation from initial melts formed ... enrichedLithos, Vol.61, 1-2, pp. 21-53.Norway, EuropeMantle plume - progressive partial melting, Clinopyroxenites, wehrlites, websterites
DS1998-0372
1998
Dunworth, E.Dunworth, E., Bell, K.Melilitolites: a new scheme of classificationCanadian Mineralogist, Vol. 36, No. 3, June pp. 895-903.GlobalPetrology - classification, Melilitolites - melilite
DS1994-0138
1994
Dunworth, E.A.Bell, K., Dunworth, E.A., Bulakh, A.G., Ivaniov, V.V.Terskii Coast, Russia: from kimberlite to carbonatite?Geological Association of Canada (GAC) Abstract Volume, Vol. 19, p.RussiaCarbonatite, Terskii Coast
DS1995-2065
1995
Dunworth, E.A.Wilson, M., Rosenbaum, J.M., Dunworth, E.A.Melilitites: partial melts of the thermal boundary layerContributions to Mineralogy and Petrology, Vol. 119, No. 2/3, pp. 181-196.GlobalMelilitites
DS1995-2066
1995
Dunworth, E.A.Wilson, M., Rosenbaum, J.M., Dunworth, E.A.Melilitites: partial melting of the internal boundary layerMineralogy and Petrology, Vol. 119, No. 2-3, pp. 181-196.MantleMelilitites, Geochemistry
DS1996-0109
1996
Dunworth, E.A.Bell, K., Dunworth, E.A., Bulakh, A.G., Ivanikov, V.V.Alkaline rocks of the Turiy Peninsula, Russia, including type localityturjaite and turjite: a reviewCanadian Mineralogist, Vol. 34, pt. 2, April pp. 265-280.RussiaAlkaline rocks, Petrology
DS1997-0297
1997
Dunworth, E.A.Dunworth, E.A., Bell, K., Arzamastsev, A.A., Bulakh, A.Age relationships, isotopic disequilibrium and trace element characteristics of the Turily Massif.....Geological Association of Canada (GAC) Abstracts, POSTER.Russia, Kola PeninsulaCarbonatite, Terskii Coast pipes
DS1997-0298
1997
Dunworth, E.A.Dunworth, E.A., Bell, K., Bulakh, A.G., Ivanikov, V.V.The Turiy massif: the role of A1 coordination and major element partitioning in melilitolites, carbonatites...Geological Association of Canada (GAC) Abstracts, Russia, Kola PeninsulaCarbonatite
DS1998-0373
1998
Dunworth, E.A.Dunworth, E.A., Wilson, M.Olivine melilitites of the southwest German Tertiary volcanic province: mineralogy and petrogenesis.Journal of Petrology, Vol. 39, No. 10, Oct. pp. 1805-GermanyMelilitites
DS2003-0358
2003
Dunworth, E.A.Dunworth, E.A., Bell, K.The Turiy Massif, Kola Peninsula, Russia: mineral chemistry of an ultramafic alkalineMineralogical Magazine, Vol. 67, 3, pp. 423-52.Russia, Kola PeninsulaCarbonatite
DS200412-0492
2003
Dunworth, E.A.Dunworth, E.A., Bell, K.The Turiy Massif, Kola Peninsula, Russia: mineral chemistry of an ultramafic alkaline carbonatite intrusion.Mineralogical Magazine, Vol. 67, 3, pp. 423-52.Russia, Kola PeninsulaCarbonatite
DS201605-0897
2016
Duparc, O.H.Schoor, M., Boulliard, J.C., Gaillou, E., Duparc, O.H., Esteve, I., Baptiste, B., Rondeau, B., Fritsch, E.Plastic deformation in natural diamonds: rose channels associated to chemical twinning.Diamond and Related Materials, in press available 14p.TechnologyDiamond morphlogy
DS2000-0488
2000
Dupas-BruzekKerschhofer, L., Rubiem Sharp, Connell, Dupas-BruzekKinetics of intracrystalline olivine - ring woodite transformationPhysical Earth and Planetary Interiors, Vol. 121, No. 1-2, pp.59-76.GlobalRingwoodite
DS1995-0464
1995
Dupeyrat, L.Dupeyrat, L., Sotin, C., Parmentier, E.M.Thermal and chemical convection in planetary mantlesJournal of Geophy. Res. Sol., Vol. 100, No. 1, Jan. 10, pp. 497-520.MantleGeochemistry, Convection
DS1993-0383
1993
DuPlessis, A.DuPlessis, A.A diamond in the rough... Chuck Fipke and Dia Met set off a Canadian diamond rushCanadian Pacific Airlines on Board magazine, February pp. 35-41Northwest TerritoriesNews item, Popular account
DS1950-0061
1951
Duplessis, A.J.Duplessis, A.J.Die Bende Op die Grens: Avontuur Speurverhaal Uit die Oue Dae Van die Kimberley Diamantdelwerye.Pretoria: V.d. Walt., 230P.South AfricaKimberley, Diamond
DS1997-0299
1997
DuPlessis, A.J.DuPlessis, A.J.South Africa - rainbow nation of mineral wealthEngineering and Mining Journal, Vol. 198, No. 5, May pp. 16ee-nnSouth AfricaOverview, Mining, environmental
DS1989-0321
1989
Duplessis, C.Dagbert, M., Buchanan, M.J., Duplessis, C.Evaluating industrial minerals deposits- Microcomputers can helpThe Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Annual Meeting Preprint, Outline of slide comments only, 8p. Database # 18040GlobalComputer, Program -slide comments only
DS1990-0432
1990
DuPlessis, C.P.DuPlessis, C.P., Walraven, F.The tectonic setting of the Bushveld Complex in Southern Africa Part 1.Structural deformation and distributionTectonophysics, Vol. 179, pp. 305-319Southern AfricaTectonics -structure, Bushveld Complex
DS2000-0251
2000
DuPlessis, I.DuPlessis, I., Viljoen, R.M., Smit, J.T.Novel liberation technology... mentions diamond processing but not specific to diamonds.Minerals Engineering, Conference 2p, abstractSouth AfricaMineral processing - comminution
DS1960-0139
1961
Duplessis, J.H.Duplessis, J.H.Diamonds are Dangerous. the Adventures of an Agent of the International Diamond Security Organization.New York: John Day, 250P.Democratic Republic of Congo, Zimbabwe, Central AfricaKimberley, Katanga, Idb
DS1987-0170
1987
Dupont, P.L.Dupont, P.L., Lapierre, H., Gravelle, BertrandCaracterisation du magmatism Proterozoique superieur en Afrique de l'ouestet implications geodynamiques: rrifts intracratoniques au Panafricain?Canadian Journal of Earth Sciences, Vol. 24, pp. 96-109.GlobalAlkaline rocks, magmatism
DS1860-0636
1889
Dupont.Lemaire, C., Dupont.Carte des Mines D'or et de le Diamant du CapRev. France De L'etranger Et Des Colonies (paris), SEPT. 1Africa, South Africa, Griqualand WestDiamond Occurrence
DS1998-0374
1998
Duppenbecker, S.J.Duppenbecker, S.J., Illiffe, J.E.The application of basin modelling techniquesGeological Society of London Spec. Pub, No. 141, 256p. $ 125.00EuropeBook - ad, Basins - models
DS1990-0433
1990
Dupre, B.Dupre, B., Arndt, N.T.lead isotopic compositions of Archean komatiites and sulfidesChemical Geology, Vol. 85, No. 1/2, July 10 pp. 35-56AustraliaKambalda, Komatiites
DS1991-0535
1991
Dupre, B.Gariepy, C., Dupre, B.lead isotopes and crust mantle evolutionMineralogical Association of Canada -Short Course Handbook, Vol. 19, Chapter 6, pp. 191-224GlobalMantle, geochronology, Subduction zones
DS1993-1388
1993
Dupre, B.Schiano, P., Algre, C.J., Dupre, B., Lewin, E., Joron, J-L.Variability of trace elements in basaltic suitesEarth and Planetary Science Letters, Vol. 119, No. 1-2, August pp. 37-52GlobalGeochemistry, Basalt
DS1996-0395
1996
Dupre, B.Dupre, B., Gaillardet, J., Rousseau, D., Allegre, C.J.Major and trace elements of river borne material: The Congo BasinGeochimica et Cosmochimica Acta, Vol. 60, No. 8, April pp. 1301-1321.Central African RepublicCongo River Basin, Black Rivers, weathering
DS2002-1056
2002
Dupre, B.Millot, R., Gaillardet, J., Dupre, B., Allegre, C.J.The global control of silicate weathering rates and the coupling of physical erosion: new insights from riversEarth and Planetary Science Letters, Vol.196, 1-2, Feb.28, pp.83-98.Northwest Territories, Alberta, Manitoba, Ontario, QuebecGeomorphology
DS1991-0899
1991
Dupree, R.Kohn, S.C., Dupree, R., Mortuza, M.G., Henderson, C.M.B.An NMR study of structure and ordering in synthetic K2gSi5O12, a leuciteanaloguePhys. Chem. Minerals, Vol. 18, pp. 144-152GlobalMineral chemistry, Leucite
DS1995-0989
1995
Dupree, R.Kohn, S.C., Henderson, C.M.B., Dupree, R.Si-Al order in leucite revisited: new information from an analcite derivedanalogue.American Mineralogist, Vol. 80, July-Aug. No. 7-8, pp. 705-714.GlobalMineralogy, Leucite
DS1996-0396
1996
Dupuis, J.Dupuis, J., Cookenboo, H., Foulkes, J.Integrated kimberlite exploration program in northwest Territories: Ranch Lake, Jericho and5034 Diamondiferous kimberlites.northwest Territories Exploration overview 1995, March pp. 3-10. abstractNorthwest TerritoriesHistory, GIS, Deposit -Ranch Lake, Jericho, 5034
DS1986-0191
1986
Duput, C.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
DS1987-0062
1987
DupuyBodinier, J.L., DupuyDistribution of trace transition elements in olivine and pyroxenes from ultramafic xenoliths: application of microprobe analysisAmerican Mineralogist, Vol. 72, pp. 902-913LesothoAnalyses
DS1989-0933
1989
Dupuy, C.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
DS1990-0218
1990
Dupuy, C.Bodinier, J.L., Vasseur, G., Vernieres, J., Dupuy, C., Fabries, J.Mechanisms of mantle metasomatism: geochemical evidence from the Lherzorogenic peridotiteJournal of Petrology, Vol. 31, No. 3, June pp. 597-628GermanyMantle Metasomatism, Geochemistry
DS1991-0102
1991
Dupuy, C.Bernardgriffiths, J., Fourcade, S., Dupuy, C.Isotopic study (Strontium, neodymium, Oxygen and Carbon) of lamprophyresEarth Planetary Science Letters, Vol. 103, No. 1-4, April pp. 190-199MoroccoGeochronology, Crust, lamprophyres
DS1991-0413
1991
Dupuy, C.Dupuy, C., Mevel, C., Bodinier, J-L, Savoyant, L.Zabargad peridotite: evidence for multistage metasomatism during Red SeariftingGeology, Vol. 19, No. 7, July pp. 722-725GlobalMantle Metasomatism, Peridotites
DS1991-1131
1991
Dupuy, C.Menzies, M., Dupuy, C., Nicolas, A.Orogenic lherzolites and mantle processes #2Terra News, Vol. 3, No. 1, pp. 6-8GlobalWorkshop -overview, Mantle -lherzolites
DS1992-0337
1992
Dupuy, C.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
DS1992-0402
1992
Dupuy, C.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
Dupuy, C.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
DS1993-0716
1993
Dupuy, C.Ionov, D.A., Dupuy, C., O'Reilly, S.Y., Kopylova, M.G., GenshaftCarbonated peridotite xenoliths from Spitzbergen: implications for trace element signature of mantle carbonate MetasomatismEarth and Planetary Science Letters, Vol. 119, No. 3, September pp. 283-298NorwayMantle Metasomatism, Geochronology
DS1993-0717
1993
Dupuy, C.Ionov, D.A., Dupuy, C., O'Reilly, S.Y., Kopylova, M.G., GenshaftCarbonated peridotite xenoliths from Spitsbergen: implications from trace element signature of mantle carbonate MetasomatismEarth and Planetary Science Letters, Vol. 119, No. 3, September pp. 283-298NorwayXenoliths, Mantle Metasomatism
DS1995-0465
1995
Dupuy, C.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
DS202012-2212
2019
Dupuy, D.C.Dupuy, D.C., Phillips, J.C.Selecting a diamond verification instrument based on the results of the Assure program: an initial analysis.Journal of Gemmology, Vol. 36, pp. 606-619.Globalluminescence

Abstract: Recently, the rapid growth in synthetic diamond production-particularly in melee sizes-and the salting of melee parcels with synthetics have generated a commensurate increase in the need for diamond verification instruments (DVIs). Ongoing independent third-party testing of these instruments is being done through the Assure Program. DVI performance is tested in a UL laboratory using carefully developed testing standards and sample sets (i.e. natural diamonds and as-grown and treated synthetics, as well as simulants as appropriate). The initial phase of testing was performed during latter 2018 and the first part of 2019, and as of July 2019 results for 16 widely available devices from 12 DVI manufacturers were published online in the Assure Directory (https://diamondproducers.com/assure/assure-directory). From these test results, the authors have evaluated several important parameters that will help users select the best instrument for their needs. Performance results from several additional DVIs are expected to be released in the near future, and further testing and publi-cation of the data will occur as new instruments are introduced and existing ones are updated.
DS202001-0008
2019
Dupuy, H.Dupuy, H., Phillips, J.G.Selecting a diamond verification: instrument based on the results of the Assure program: an initial analysis.Journal of Gemmology, Vol. 36, 7, pp. 606-619.Globaldiamond identification
DS1994-0787
1994
Duquette, D.Hrabi, R.B., Grant, J.W., Berclaz, A., Duquette, D., Villeneuve, M.E.Geology of the northern half of the Winter Lake supracrustal belt, SlaveProvince, Northwest Territories.Geological Survey of Canada Current Research, No. 1994, C, pp. 13-22.Northwest TerritoriesGeology, Winter Lake
DS202202-0189
2022
Durai, P.R.Brahma, S., Sahoo, S., Durai, P.R.First report of carbonatite from Gundlupet area, western Dharwar Craton, Karnataka, southern India.Journal of the Geological Society of India, Vol.98, pp. 35-40. Indiacarbonatite

Abstract: A new carbonatite body has been discovered from Gundlupet area, western Dharwar craton, southern India which is located at juncture of major shear zones namely, Kollegal shear zone to the east, Sargur shear zone to the west and Moyar shear zone to the south. The carbonatite and associated syenite have intruded into the peninsular gneissic complex. The southern margin of the syenite has a tectonic contact with the peninsular gneissic complex suggesting their emplacement is related to the splay shear of Moyar shear zone. The Gundlupet carbonatite is dominantly sövite with minor beforsite and iron rich carbonatite which are associated with phenocrystic magnetite, apatite, amphibole, pyroxene and monazite. Fenitisation is observed in local scale along the contact of carbonatite and syenite where metasomatic alterations took place to give rise to alkali amphibole and pyroxene rich rock. Geochemically, the carbonatite is characterised by high CaO content (48.86%-51.80%), P2O5 (0.35%-3.23%) and low SiO2 (3.09%-5.30%). The high Sr (5750-13445 ppm) content and low Ni, Cr, Zn and Cu content indicates that the melt has undergone some degree of fractionation before crystallization. Gundlupet carbonatite is enriched in LREE with values ranging from 5666 ppm to 7530 ppm and average LREE of 6248 ppm.
DS200812-0943
2008
DuraiswamiRay, R., Shukia, A.D., Sheth, H.C., Ray, J.S., Duraiswami, Vanderkluysen, Rautela, MallikHighly heterogeneous Precambrian basement under the central Deccan Traps, India: direct evidence from xenoliths in dykes.Gondwana Research, Vol. 13, 3, pp. 375-385.IndiaPetrology - dykes
DS200912-0360
2009
Duraiswami, R.A.Karmalkar, N.R., Duraiswami, R.A., Chalapathi Rao, N.V., Paul, D.K.Mantle derived mafic ultramafic xenoliths and the nature of Indian sub-continental lithosphere.Journal of the Geological Society of India, Vol. 73, no. 5, May, pp. 657-679.IndiaKalyandurg, Brahmanpalle clusters
DS201112-0504
2009
Duraiswami, R.A.Karmalkar, N.R., Duraiswami, R.A., Chalapthi Rao, N.V., Paul, D.K.Mantle derived mafic-ultramafic xenoliths and the nature of Indian sub-continental lithosphere.Journal of the Geological Society of India, Vol. 73, pp. 657-679.India, Andhra PradeshKimberlites, lamproites, nephelinites, basanites
DS201312-0461
2014
Duraiswami, R.A.Karmalkar, N.R., Duraiswami, R.A., Jonnalagadda, M.K., Griffin, W.L.Mid-Cretaceous lamproite from the Kutch region, Gujarat, India: genesis and tectonic implications.Gondwana Research, Vol. 26, 3-4, pp. 942-956.IndiaLamproite
DS201412-0444
2014
Duraiswami, R.A.Karmalkar, N.R., Duraiswami, R.A., Jonnalagadda, M.K., Griffin, W.L.Mid-Cretaceous lamproite from the Kutch region, Gujarat, NW India: genesis and tectonic implications.Gondwana Research, Vol. 26, 3-4, Nov. pp. 942-956.IndiaLamproite
DS201801-0012
2017
Duraiswami, R.A.Duraiswami, R.A.Textural evidences of late stage carbonate dissolution precipitation and stable isotope exchange re-equilibration in the Kangankunde carbonatite complex, Malawi.Carbonatite-alkaline rocks and associated mineral deposits , Dec. 8-11, abstract p. 39-40.Africa, Malawideposit - Kangankunde

Abstract: The Kangankunde carbonatite complex, southern Malawi is an eroded remnant of a carbonatite depocentre belonging to the Lower Cretaceous Chilwa Alkaline Province (Garson and Campbell-Smith, 1965; Karmalkar et al., 2010). The carbonatite complex consists of fenites, carbonated agglomeratic breccias and ankeritic-ferron dolomite carbonatite with sporadic patches of REE minerals. Coarse pegmatitic siderite and ankeritic carbonatite hosts exotic cavities and vugs that contain RE minerals like monazite, synchysite, bastnasite, and florencite-goyazite along with barite and strontianite. Bright green monazite occurs with thick quartz veins and as disseminations within host carbonatites (Garson and Campbell-Smith, 1965; Holt, 1965). Texturally, the host carbonatite exhibits euhedral to subhedral rhombohedra of ankerite-calcite and dolomite set in a fine groundmass. However samples close to mineralized zones show streaky textures, streaming effects and patterns that resemble remobilization and fluidization. Textural evidences such as presence of pseudomorphs containing the REE mineral assemblage, veinlets and drusy cavities indicate that REE mineralization replaced earlier formed carbonates (Wall et al. 1994). SEM micromorphology of such carbonatites show several dissolution-precipitation features indicating that there was a pervasive fluid interaction with the host subsequent to cooling and crystallization. Within cavities and vugs, the precipitation is closely associated with monazite veins and formation of minerals like collinsite, synchysite and rare aragonite (Duraiswami and Shaikh, 2010). Carbon and oxygen isotope ratios were determined on 8 bulk carbonatite powders from Kangankunde using Thermo Fisher Scientific GasBench II, equipped with autosampler (CTC Analytics AG, Zwingen, Switzerland), and coupled to a Delta Plus XP Mass Spectrometer at NGRI, Hyderabad. International Standards NBS-19-1 and NBS-18-1 plus internal standards were used. The internal precision (1s) measured for raw d18O and d13C was 0.04–0.08‰ and 0.03 to 0.06 respectively. The ?13C VS V-PDB show restricted range (-0.31 to -2.76) but ?18O VS V-SMOW values vary widely (8.22 to 24.5). The samples analysed in the present study plot outside the Primary Igneous Carbonatite field (Demény et al., 2004) and are related either to carbo-hydrothermal fluids or alteration of dolomite by a later, cooling, deuteric fluid (Fendley et al., 2017). This study provides conclusive textural evidences (pseudomorphic replacements, atolls, iron-oxide exsolution fringes from dolomite/ankerite, coloform banding, secondary veinlets, etc.) to supports geochemical and stable isotopic inferences about the role of late stage hydrothermal fluids and subsequent alterations in the Kangankunde carbonatite complex (Wall and Mariano, 1996, Wall et al., 1994, Doroshkevich et al., 2009, Fendley et al., 2017).
DS200512-0960
2004
Durali, S.Seitz, H-M., Brey, G.P., Lahaye, Y., Durali, S., Weyer, S.Lithium isotopic signatures of peridotite xenoliths and isotopic fractionation at high temperature between olivine and pyroxenes.Chemical Geology, Vol. 212, 1-2, pp. 163-177.MantlePetrology - not specific to diamonds
DS201806-1248
2018
Durali-Muller, S.Seitz, H-M., Brey, G.P., Harris, J.W., Durali-Muller, S., Ludwig, T., Hofer, H.E.Ferropericlase inclusions in ultradeep diamonds from Sao Luiz ( Brazil): high Li abundances and diverse Li-isotope and trace element compositions suggest an origin from a subduction melange.Mineralogy and Petrology, in press available, 10p.South America, Brazil, Juinadeposit - Sao Luiz

Abstract: The most remarkable feature of the inclusion suite in ultradeep alluvial and kimberlitic diamonds from Sao Luiz (Juina area in Brazil) is the enormous range in Mg# [100xMg/(Mg?+?Fe)] of the ferropericlases (fper). The Mg-richer ferropericlases are from the boundary to the lower mantle or from the lower mantle itself when they coexist with ringwoodite or Mg- perovskite (bridgmanite). This, however, is not an explanation for the more Fe-rich members and a lowermost mantle or a “D” layer origin has been proposed for them. Such a suggested ultra-deep origin separates the Fe-rich fper-bearing diamonds from the rest of the Sao Luiz ultradeep diamond inclusion suite, which also contains Ca-rich phases. These are now thought to have an origin in the uppermost lower mantle and in the transition zone and to belong either to a peridotitic or mafic (subducted oceanic crust) protolith lithology. We analysed a new set of more Fe-rich ferropericlase inclusions from 10 Sao Luiz ultradeep alluvial diamonds for their Li isotope composition by solution MC-ICP-MS (multi collector inductively coupled plasma mass spectrometry), their major and minor elements by EPMA (electron probe micro-analyser) and their Li-contents by SIMS (secondary ion mass spectrometry), with the aim to understand the origin of the ferropericlase protoliths. Our new data confirm the wide range of ferropericlase Mg# that were reported before and augment the known lack of correlation between major and minor elements. Four pooled ferropericlase inclusions from four diamonds provided sufficient material to determine for the first time their Li isotope composition, which ranges from ?7Li?+?9.6 ‰ to ?3.9 ‰. This wide Li isotopic range encompasses that of serpentinized ocean floor peridotites including rodingites and ophicarbonates, fresh and altered MORB (mid ocean ridge basalt), seafloor sediments and of eclogites. This large range in Li isotopic composition, up to 5 times higher than ‘primitive upper mantle’ Li-abundances, and an extremely large and incoherent range in Mg# and Cr, Ni, Mn, Na contents in the ferropericlase inclusions suggests that their protoliths were members of the above lithologies. This mélange of altered rocks originally contained a variety of carbonates (calcite, magnesite, dolomite, siderite) and brucite as the secondary products in veins and as patches and Ca-rich members like rodingites and ophicarbonates. Dehydration and redox reactions during or after deep subduction into the transition zone and the upper parts of the lower mantle led to the formation of diamond and ferropericlase inclusions with variable compositions and a predominance of the Ca-rich, high-pressure silicate inclusions. We suggest that the latter originated from peridotites, mafic rocks and sedimentary rocks as redox products between calcite and SiO2.
DS200712-0279
2007
Duran, A.Duran, A., Caginalp, G.Overreaction diamonds: precursors and aftershocks for significant price changes.Quantitative Finance, Vol. 7, 3, pp. 321-342.GlobalDiamond prices
DS200712-0280
2007
Duran, A.Duran, A., Caginalp, G.Overreaction diamonds: precursors and aftershocks for significant price changes.Quantitative Finance, Vol. 7, 3, pp. 321-342.GlobalDiamond prices
DS202204-0516
2022
Duran, L.Boscaini, A., Marzoli, A., Bertrand, H., Chiagradia, M., Jourdan, F., Faccende, M., Meyzen, C.M., Callegaro, S., Duran, L. Cratonic keels controlled the emplacement of the Central Atlantic Magmatic Province ( CAMP)Earth and Planetary Science Letters, Vol. 584, doi 10.1016/j.espl.2022.117480Africa, Mali, Mauritaniacraton

Abstract: Large Igneous Provinces (LIPs) are exceptionally voluminous magmatic events frequently related to continental break-up, global climate changes and mass extinctions. One interesting aspect of many LIPs is their spatial proximity to cratons, begging the question of a potential control of thick lithosphere on their emplacement. In this study, we investigate the relationship between the emplacement of the Central Atlantic Magmatic Province (CAMP) and the thick lithospheric mantle of the Precambrian cratons that formed the central portion of Pangea and are currently located on the continents surrounding the Central Atlantic Ocean. CAMP outcrops are frequently located over the margins of the thick cratonic keels, as imaged by recent tomographic studies, suggesting a role of lithosphere architecture in controlling magma genesis and emplacement. Here we focus on CAMP dykes and sills from the Hank, Hodh, and Kaarta basins in North-Western Africa (NW-Africa, Mali and Mauritania) emplaced at the edge of the Reguibat and Leo-Man Shields. The investigated intrusive rocks show compositions similar to most CAMP magmas, in particular those of the Tiourjdal geochemical group, limited to NW-Africa, and of the Prevalent group, occurring all over the CAMP. Geochemical modelling of CAMP basalts requires a Depleted MORB Mantle (DMM) source enriched by recycled continental crust (1-4%) and melting beneath a lithosphere of ca. 80 km in thickness. On the contrary, melting under a significantly thicker lithosphere (>110 km) does not produce magmas with compositions similar to those of CAMP basalts. This suggests that CAMP magmatism was likely favoured by decompression-induced partial melting of the upwelling asthenospheric mantle along the steep lithospheric boundaries of stable cratons. The architecture of the pre-existing lithosphere (i.e., the presence of stable thick cratonic keels juxtaposed to relatively thinner lithosphere) appears to have been a critical factor for localizing mantle upwelling and partial melting during extensive magmatic events such as in the CAMP.
DS200512-0207
2004
Durance, P.Danyushevsky, L.V., Leslie, R.A.J., Crawford, A.J., Durance, P.Melt inclusions in primitive olivine phenocrysts: the role of localized reaction processes in the origin of anomalous compositions.Journal of Petrology, Vol. 45, 12, pp. 2531-2553.Petrology - not specific to diamonds
DS1910-0180
1911
Durand, H.M.Sir.Durand, H.M.Sir.A Holiday in South AfricaEdinburgh: Blackwood., 275P.South AfricaHistory, Biography
DS1860-0311
1879
Durand, M.W.Durand, M.W.Voyages du P. Duparquet dans l'afrique Australe D'apres Seslettres Par M. l'abbe Durand.Soc. Geogr. (paris) Bulletin., PP. 153-170; PP. 275-292.Africa, South AfricaTravelogue
DS201212-0172
2012
Durand, S.Durand, S., Chambat, F., Matas, J., Ricard, Y.Constraining the kinetics of mantle phase changes with seismic data.Geophysical Journal International, in press availableMantleGeophysics - seismics
DS201602-0229
2016
Durand, S.Perrillat, J.P., Chollet, M., Durand, S., van de Moortele, B., Chambat, F., Mezouar, M., Daniel, I.Kinetics of the olivine-ring woodite transformation and seismic attentuation in the Earth's mantle transition zone.Earth and Planetary Science Letters, Vol. 433, pp. 360-369.MantleGeophysics - seismics

Abstract: In regions of the mantle where multi-phases coexist like at the olivine-wadsleyite-ringwoodite transitions, the stress induced by the seismic waves may drive a mineralogical reaction between the low to high pressure phases, a possible source of dissipation. In such a situation, the amount of attenuation critically depends on the timescale for the phase transformations to reach equilibrium relative to the period of the seismic wave. Here we report synchrotron-based measurements of the kinetics of the olivine to ringwoodite transformation at pressure-temperature conditions of the co-stability loop, for iron-rich olivine compositions. Both microstructural and kinetic data suggest that the transformation rates are controlled by growth processes after the early saturation of nucleation sites along olivine grain boundaries. Transformation-time data show an increase of reaction rates with temperature and iron content, and have been fitted to a rate equation for interface-controlled transformation: G=k0?T?exp?[n?XFa]?exp?[?(?Ha+PV?)/RT]×[1?exp?(?Gr/RT)]G=k0?T?exp?[n?XFa]?exp?[?(?Ha+PV?)/RT]×[1?exp?(?Gr/RT)], where XFaXFa is the fayalite fraction, the exponential factor n=9.7n=9.7, View the MathML sourceln?k0=?9.1 ms?1. View the MathML sourceXFa?1 and ?Ha=199 kJ/mol?Ha=199 kJ/mol, assuming V?=0 cm3/molV?=0 cm3/mol. Including these new kinetic results in a micro-mechanical model of a two-phase loop (Ricard et al., 2009), we predict View the MathML sourceQK?1 and View the MathML sourceQ??1 significantly higher than the PREM values for both body waves and normal modes. This attests that the olivine-wadsleyite transition can significantly contribute to the attenuation of the Earth's mantle transition zone.
DS1986-0175
1986
Durand-Wackenheim, C.Debeaux, M., Durand-Wackenheim, C., Thiebaut, J.Cortlandite, monchiquite and ophites in the vicinity of the Job Springs, Haute-Garonne, France.(in French)Bulletin. de la Soc. d'Histoire Naturelle de Toulouse, Vol. 122, pp. 79-86FranceMonchiquite, Geochemistry
DS1991-0414
1991
Durant, D.Durant, D.Overview -conference report on the International Volcanological Congress conference held last September 1990 in Mainz, West GermanyGeoscience Canada, Vol. 18, No. 1, March pp. 22-24GlobalConference report, Volcanology
DS1990-0434
1990
Durasova, N.A.Durasova, N.A., Belyayeva, V.I., Ignatenko, K.I.Distribution and modes of occurrence of copper in boninite type magmasGeochemistry International, Vol. 27, No. 2, February pp. 127-132RussiaBoninite
DS1984-0248
1984
Durazzo, A.Durazzo, A., Taylor, L.A., Shervais, J.W.Ultramafic Lamprophyre in a Carbonate Platform Environment, mt. Queglia, Abruzzo, Italy.Neues Jahrbuch f?r Mineralogie, Vol. 150, No. 2, PP. 199-217.ItalyBlank
DS1989-1063
1989
Durazzo, A.Morten, L., Taylor, L.A., Durazzo, A.Spinels in harzburgite and lherzolite inclusions From the San Giovannillarione quarry,Lessini Mountains, Veneto Region, ItalyMineralogy and Petrology, Vol. 40, No. 1, March pp. 73-88ItalyHarzburgite, Lherzolite
DS1999-0184
1999
Durazzo, A.Durazzo, A.Using mineralogy in the petrogenesis of ultramafic rocks: examples fromItaly.International Geology Review, Vol. 41, pp. 175-90.ItalyAlnoite dike, Basanite, Lessini Mountains
DS201212-0173
2012
Duretz, T.Duretz, T., Gerya, T.V., Kaus, B.J.P., Andersen, T.B.Thermomechanical modeling of slab eduction.Journal of Geophysical Research, Vol. 117, B08411 17p.MantlePlate tectonics - subduction
DS201212-0174
2012
Duretz, T.Duretz, T., Schmalholz, S.M., Gerya, T.V.Dynamics of slab detachment.Geochemical, Geophysics, Geosystems: G3, Vol. 13, 3, 17p.MantleBreakoff, heating
DS201312-0231
2013
Duretz, T.Duretz, T., Gerya, T.V.Slab detachment during continental collision: influence of crustal rheology and interaction with lithospheric delamination.Tectonophysics, Vol. 602, pp. 124-140.MantleRheology
DS201909-2108
2019
Duretz, T.Yamato, P., Duretz, T., Angiboust, S.Brittle/ductile deformation of eclogites: insights from numerical models.Geochemistry, Geophysics, Geosystems, Vol. 20, 7, pp. 3116-3133.mantleeclogites

Abstract: How rocks deform at depth during lithospheric convergence and what are the magnitudes of stresses they experience during burial/exhumation processes constitute fundamental questions for refining our vision of short?term (i.e., seismicity) and long?term tectonic processes in the Earth's lithosphere. Field evidence showing the coexistence of both brittle and ductile deformation at high pressure?low temperature (HP?LT) conditions particularly fuels this questioning. We here present 2D numerical models of eclogitic rock deformation by simple shear performed at centimeter scale. To approximate the eclogite paragenesis, we considered the deformed medium as composed of two mineral phases: omphacite and garnet. We run a series of models at 2.0 GPa and 550 °C for different background strain rates (from 10?14 s?1 to 10?8 s?1) and for different garnet proportions (from 0% to 55%). Results show that whole rock fracturing can occur under HP?LT conditions for strain rates larger than ~10?10 s?1. This suggests that observation of brittle features in eclogites does not necessarily mean that they underwent extreme strain rate. Care should therefore be taken when linking failure of eclogitic rocks to seismic deformation. We also explore the ranges of parameters where garnet and omphacite are deforming with a different deformation style (i.e., frictional vs viscous) and discuss our results in the light of naturally deformed eclogitic samples. This study illustrates that effective stresses sustained by rocks can be high at these P?T conditions. They reach up to ~1 GPa for an entirely fractured eclogite and up to ~500 MPa for rocks that contain fractured garnet.
DS201212-0175
2012
Durey, H.Durey, H.Sacred and symbolic Ancient India and the lure of its diamonds.hughdurey.com website and hughdurey @gmail.com, $ 85.00 and sea mail $ 35. or airmail $56.00IndiaBook - photographs
DS2000-0252
2000
Durham, B.Durham, B.GQ diamond discoveryToronto Geological Discussion Group, absts Oct. 24, pp. 21-22.OntarioOverview
DS200612-0814
2006
Durham, B.Li, L.,Weidner, D., Raterron, P., Chen, J., Vaughan, M., Mei, S., Durham, B.Deformation of olivine at mantle pressure using D-DIA.European Journal of Mineralogy, Vol. 18, 1, pp. 7-19.TechnologyExperimental petrology
DS1970-0618
1973
Durham, C.C.Allan, J.F., Cameron, E.M., Durham, C.C.Reconnaissance geochemistry using lake sediments of a 36, 000 sq mile area of northwestern Shield.Geological Survey of Canada (GSC) Paper, No. 72-50Quebec, OntarioGeochemistry
DS201012-0491
2010
Durham, W.B.Mei, S., Suzuki, A.M., Kohlstadt, D.L., Dixon, N.A., Durham, W.B.Experimental constraints on the strength of the lithospheric mantle.Journal of Geophysical Research, Vol. 115, B8, B08204.MantleGeophysics - seismics
DS201901-0028
2018
Durham, W.B.Dixon, N.A., Durham, W.B.Measurement of activation volume for creep of dry olivine at upper-mantle conditions.Journal of Geophysical Research: Solid Earth, Vol. 123, 10, pp. 8459-8473.Mantleolivine

Abstract: Olivine is the most abundant and among the weakest phases in Earth's upper mantle, and thus, its rheological properties play a critical role in governing thermal structure and convective flow in the upper mantle. A persistent obstacle to constraining the in situ flow properties of olivine by laboratory experiment has been the difficulty in resolving the effect of pressure, which is weak within the 0? to ~2?GPa pressure range of conventional laboratory deformation instruments but potentially strong over the 1? to ~14?GPa range of the upper mantle. Using a deformation?DIA, one of a new generation of bonafide deformation devices designed for operation to ?10 GPa, we have deformed dry, polycrystalline San Carlos olivine in high?temperature creep with the singular intent of providing the best achievable measurement of activation volume V* and a comprehensive statement of uncertainty. Under strictly dry conditions, at constant temperature (1,373 K) and strain rate (1 × 10?5 s?1), varying only pressure (1.8 to 8.8 GPa), we measure V* = 15 ± 5 cm3/mol. We have reproduced the well?known mechanism change from [100]?slip to [001]?slip near 5 GPa and determined that, whatever the change in V* associated with the change in slip system, the effective value of 15 ± 5 cm3/mol is still accurate for modeling purposes in the 2? to 9?GPa pressure range. This is a substantial pressure effect, which in the absence of a temperature gradient would represent a viscosity increase from the top to bottom of the upper mantle of 5 ± 2 orders of magnitude.
DS201911-2552
2019
Durheim, R.Ortiz, K., Nyblade, A., Meijde, M., Paulssen, H., Kwadiba, M., Ntibinyane, O., Durheim, R., Fadel, I., Homman, K.Upper mantle P and S wave velocity structure of the Kalahari craton and surrounding Proterozoic terranes, southern Africa.Geophysical Research Letters, Vol. 46, 16, pp. 9509-9518.Africa, South Africageophysics - seismics

Abstract: P and S waves travel times from large, distant earthquakes recorded on seismic stations in Botswana and South Africa have been combined with existing data from the region to construct velocity models of the upper mantle beneath southern Africa. The models show a region of higher velocities beneath the Rehoboth Province and parts of the northern Okwa Terrane and the Magondi Belt, which can be attributed to thicker cratonic lithosphere, and a region of lower velocities beneath the Damara?Ghanzi?Chobe Belt and Okavango Rift, which can be attributed a region of thinner off?craton lithosphere. This finding suggests that the spatial extent of thick cratonic lithosphere in southern Africa is greater than previously known. In addition, within the cratonic lithosphere an area of lower velocities is imaged, revealing parts of the cratonic lithosphere that may have been modified by younger magmatic events.
DS201012-0121
2010
Durmus, B.Cooper, A.F., Durmus, B., Palin, J.M.Petrology and petrogenesis of carbonatitic rocks in syenites from Central Anatolia, Turkey.International Mineralogical Association meeting August Budapest, abstract p. 551.Europe, TurkeyCarbonatite
DS1984-0249
1984
Duroc-Danner, J.M.Duroc-Danner, J.M.On the Identification of a Light Pink Pyrope Garnet and a Kornerupine.Journal of Gemology AND Proceedings GEMM. Association GREAT BRITAIN., Vol. 19, No. 4, PP. 311-316.GlobalCrystallography
DS1996-0693
1996
Durocher, C.A.Johnson, K.W., Durocher, C.A.Trends technologies, and case histories for the modern explorationistProspectors and Developers Association of Canada (PDAC) Short Course, 250p. approx. $ 45.00GlobalBook -table of contents, Short course -Exploration technology
DS2001-0283
2001
Durocher, K.E.Durocher, K.E., Kyser, K., Delaney, G.D.Thermotectonic studies in the Paleoproterozoic Glennie Domain, Trans Hudson orogen.Precambrian Research, Vol. 109, No. 3-4. July, pp. 175-202.Manitoba, AlbertaTrans Hudson Orogeny, Tectonics, geothermometry
DS201112-0373
2011
Durr, H.H.Gleeson, T., Smith, L., Moosdorf, N., Hartmann, J., Durr, H.H., manning, A.H., Van Beek, P.H., Jellinek, A.Mapping permeability over the surface of the Earth.Geophysical Research Letters, Vol. 38, L02401MantleGeophysics
DS1996-0397
1996
Durr, S.B.Durr, S.B., Dingeldey, D.P.The Kaoko belt (Namibia): part of a late Neoproterozoic continental scale strike slip systemGeology, Vol. 24, No. 6, June pp. 503-506NamibiaCongo Craton, Kalahari Craton, Kaoko Belt
DS1997-0300
1997
Durr, S.B.Durr, S.B., Dingeldey, D.P., Prave, A.R.Tale of three cratons: tectonostratigraphic anatomy of the Damara Orogen in northwest Namibia and the assembly ....Geology, Vol. 25, No. 12, Dec. pp. 1149-1150.NamibiaCraton, Damara Orogeny
DS1990-0666
1990
DurrheimHart, R.J., Andreoli, M.A.G., Smith, C.B., Otter, M.L., DurrheimUltramafic rocks in the centre of the Vredefort structure (South Africa):possible exposure of the upper mantleChem. Geol, Vol. 83, No. 3/4, June 25, pp. 233-248South AfricaUltramafics, Mantle - Vredefort structure
DS201012-0352
2009
Durrheim, P.H.G.M.Kgaswane, E., Nyblade, A.A., Jordi, J., Durrheim, P.H.G.M., Raymond, J., Payanos, M.E.Shear wave velocity structure of the lower crust in southern Africa: evidence for compositional heterogeneity within Archean and Proterozoic terrains.Journal of Geophysical Research, Vol. 114, B12, B12304.AfricaGeophysics - seismics
DS201312-0232
2013
Durrheim, R.Durrheim, R.Africa ARRAY studies of the structure and evolution of the African continent.AEM-SAGA Conference, Talk title listedAfricaGeophysics
DS202011-2067
2020
Durrheim, R.White-Gaynor, A.L., Nyblade, A.A., Durrheim, R., Raveloson, R., van der Meijde, M., Fadel, I., Paulssen, H., Kwadiba, M., Ntibinyane, O., Titus, N., Sitali, M.Lithospheric boundaries and upper mantle structure beneath southern Africa imaged by P and S wave velocity models.Geochemistry, Geophysics, Geosystems, 10.1029/GC008925 20p. PdfAfrica, South AfricaGeophysics, seismic

Abstract: We report new P and S wave velocity models of the upper mantle beneath southern Africa using data recorded on seismic stations spanning the entire subcontinent. Beneath most of the Damara Belt, including the Okavango Rift, our models show lower than average velocities (?0.8% Vp; ?1.2% Vs) with an abrupt increase in velocities along the terrane's southern margin. We attribute the lower than average velocities to thinner lithosphere (~130 km thick) compared to thicker lithosphere (~200 km thick) immediately to the south under the Kalahari Craton. Beneath the Etendeka Flood Basalt Province, higher than average velocities (0.25% Vp; 0.75% Vs) indicate thicker and/or compositionally distinct lithosphere compared to other parts of the Damara Belt. In the Rehoboth Province, higher than average velocities (0.3% Vp; 0.5% Vs) suggest the presence of a microcraton, as do higher than average velocities (1.0% Vp; 1.5% Vs) under the Southern Irumide Belt. Lower than average velocities (?0.4% Vp; ?0.7% Vs) beneath the Bushveld Complex and parts of the Mgondi and Okwa terranes are consistent with previous studies, which attributed them to compositionally modified lithosphere resulting from Precambrian magmatic events. There is little evidence for thermally modified upper mantle beneath any of these terranes which could provide a source of uplift for the Southern African Plateau. In contrast, beneath parts of the Irumide Belt in southern and central Zambia and the Mozambique Belt in central Mozambique, deep?seated low velocity anomalies (?0.7% Vp; ?0.8% Vs) can be attributed to upper mantle extensions of the African superplume structure.
DS1991-0415
1991
Durrheim, R.J.Durrheim, R.J., Mooney, W.D.Archean and Proterozoic crustal evolution: evidence from crustalseismologyGeology, Vol. 19, No. 6, June pp. 606-609Canada, United StatesTectonics, Crust
DS1992-0404
1992
Durrheim, R.J.Durrheim, R.J., Green, R.W.E.A seismic refraction investigation of the Archean Kaapvaal craton, SouthAfrica, using mine tremors as the energy sourceGeophys. Journal of International, Vol. 108, No. 3, March pp. 812-832South AfricaGeophysics -seismics, Craton
DS1994-0473
1994
Durrheim, R.J.Durrheim, R.J., Mooney, W.D.Evolution of the Precambrian lithosphere: seismological and geochemicalconstraintsJournal of Geophysical Research, Vol. 99, pp. 15, 359-74.Alberta, Western CanadaTectonics, Lithosphere
DS1994-0474
1994
Durrheim, R.J.Durrheim, R.J., Mooney, W.D.Evolution of the Precambrian lithosphere: seismological and geochemical constraints.Journal of Geophysical Research, Vol. 99, No. B8, Aug. 10, pp. 15, 359-374MantlePrecambrian, Xenoliths, Geophysics -seismics
DS200612-0204
2006
Durrieu, N.Cagnard, F., Durrieu, N., Gapais, D., Brun, J-P, Ehlers, C.Crustal thickening and lateral flow during compression of hot lithospheres, with particular reference to Precambrian times.Terra Nova, Vol. 18, Feb. pp. 72-78.MantleGeothermometry
DS200612-0205
2006
Durrieu, N.Cagnard, F., Durrieu, N., Gapais, D., Brun, J-P., Ehlers, C.Crustal thickening and lateral flow during compression of hot lithospheres, with particular reference to Precambrian times.Terra Nova, Vol. 18, 1, Feb. pp. 72-78.MantleGeophysics - seismics
DS200612-0206
2006
Durrieu, N.Cagnard, F., Durrieu, N., Gapais, D., Brun, J-P., Ehlers, C.Crustal thickening and lateral flow during compression of hot lithospheres, with particular reference to Precambrian times.Terra Nova, Vol. 18, 1, pp. 72-78.MantleMelting
DS1989-0380
1989
Dusansky, R.Dusansky, R.Diamonds are a governments best friend- burden free taxes on goods valued for their values- comment andreply... by Ng YkAmerican Economic Review, Vol. 79, No. 5, December pp. 1285-1290United StatesEconomics, Diamonds
DS200612-1517
2005
Duschesne, J-C.Weihed, P., Arndt, N., Billstrom, K., Duschesne, J-C., Eilu, P., Martinsson, O., Papunen, H., Lahtinen, R.Precambrian geodynamics and ore formation: the Fennoscandian shield.Ore Geology Reviews, Vol. 27, pp. 273-322.Europe, FennoscandiaMetallogeny - tectonics
DS1990-0435
1990
Dushin, V.A.Dushin, V.A.High -magnesium andesites and boninites from the initial (early) Ripheids of the Polar UralsDoklady Academy of Sciences USSR, Earth Science Section, Vol. 306, No. 3, pp. 93-96RussiaBoninites, Petrology -analyses
DS1990-0387
1990
Dushin, Y.P.Danoliv, A.P., Dementiyenko, A.I., Dushin, Y.P., Khristenko, A.I.Structural and mineralogical pre-conditions of mantle mineralization in Bureya MassifInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 2, extended abstract p. 789-791RussiaKimberlites, Pyrope
DS1995-0466
1995
Dushnisky, K.Dushnisky, K., Pelletier, C.A.Environmental risk assessment and international mineral developmentInternational Journal of Surface Mining, Reclamation and environ, Vol. 9, No. 1, pp. 19-22GlobalEnvironment, Mining development
DS202006-0917
2020
Dushyantha, N.Dushyantha, N., Batapola, N., Ilankoon, I.M.S.K., Rohitha, S., Premasiri, R., Abeysinghe, B., Ratnayake, N., Dissanayake, K.The story of rare earth elements ( REES): occurrences, global distribution, genesis, geology, mineralogy and global production.Ore Geology Reviews, Vol. 122, 17p. PdfGlobalREE

Abstract: Rare earth elements (REEs) including fifteen lanthanides, yttrium and scandium are found in more than 250 minerals, worldwide. REEs are used in various high-tech applications across various industries, such as electrical and electronics, automotive, renewable energy, medical and defence. Therefore, the demand for REEs in the global market is increasing day by day due to the surging demand from various sectors, such as emerging economies, green technology and R&D sectors. Rare earth (RE) deposits are classified on the basis of their genetic associations, mineralogy and form of occurrences. The Bayan Obo, Mountain Pass, Mount Weld and China’s ion adsorption clays are the major RE deposits/mines in the world to date and their genesis, chronology and mineralogy are discussed in this review. In addition, there are other RE deposits, which are currently being mined or in the feasibility or exploration stages. Most of the RE resources, production, processing and supply are concentrated in the Asia-Pacific region. In this regard, China holds the dominancy in the RE industry by producing more than 90% of the current rare earth requirements. Thus, REEs are used as a powerful tool by China in trade wars against other countries, especially against USA in 2019. However, overwhelming challenges in conventional RE explorations and mining make secondary RE resources, such as electric and electronic waste (e-waste) and mine tailings as promising resources in the future. Due to the supply risk of REEs and the monopoly of the REEs market, REEs recycling is currently considered as an effective method to alleviate market fluctuations. However, economical and sustainable processing techniques are yet to be established to exploit REEs via recycling. Moreover, there are growing ecological concerns along with social resistance towards the RE industry. To overcome these issues, the RE industry needs to be assessed to maintain long-term social sustainability by fostering the United Nations sustainable development goals (SDGs).
DS1993-0384
1993
Duskin, D.J.Duskin, D.J., Jarvis, W.Kimberlites in MichiganMid-continent diamonds Geological Association of Canada (GAC)-Mineralogical Association of Canada (MAC) Symposium ABSTRACT volume, held Edmonton May, pp. 99-100MichiganHistorical overview, Diamond exploration Program
DS1982-0086
1982
Dusmatov, V.D.Baratov, R.B., Klimov, G.K., Dusmatov, V.D., Gorshkov, Y.N.New Dat a on Explosion Pipes of Karkul Konchoch in Southern Tien Shan.Doklady Academy of Sciences Nauk TADZH. SSR., Vol. 25, No. 10, PP. 604-607.RussiaPetrology, Kimberlite, Pamirs, Karakul, Konchoch
DS201212-0124
2012
Dussin, I.A.Chemale, F., Dussin, I.A., Alkmim, F.F., Martins, M.S., Queiroga, G., Armstrong, R., Santos, M.N.Unravelling a Proterozoic basin history through detrital zircon geochronology: the case of the Esponhaco Supergroup, Minas Gerais, Brazil.Gondwana Research, Vol. 22, 1, pp. 200-206.South America, Brazil, Minas GeraisSan Francisco Congo paleocraton, diamond bearing sequences
DS2000-0848
2000
Dussin, T.M.Sa Carneiro Chaves, M.L., Dussin, T.M., Sano, Y.The source of the Espinhaco diamonds: evidences from Shrimp uranium-lead (U-Pb) zircon ages of Sopa conglomerate....Revista Brasileira e Geociencas, Vol. 30, No. 2, pp. 265-9.Brazil, Minas GeraisGeochronology, Deposit - Espinhaco
DS200612-1314
2006
DusunurSingh, S.C., Crawford, W.C., Carton, Seher, Combier, Cannat, Canales, Dusunur, Escartin, MirandaDiscovery of a magma chamber and faults beneath a Mid-Atlantic Ridge hydrothermal field.Nature, Vol. 442 Aug. 31, pp. 1029-1031.MantleTectonics
DS1975-0733
1978
Dutch, S.I.Dutch, S.I.The Colorado Lineament: a Middle Precambrian Wrench Fault System.Geological Society of America (GSA) Bulletin., Vol. 90, PT. 1, PP. 313-316.Colorado, North Dakota, South Dakota, WisconsinMid-continent
DS1981-0144
1981
Dutch, S.I.Dutch, S.I.A Three Plate Model of the Midcontinent Gravity HighGeological Society of America (GSA), Vol. 13, No. 6, P. 276. (abstract.).GlobalMid-continent
DS1983-0205
1983
Dutch, S.I.Dutch, S.I.Geophysics and the Evolution of the MidcontinentGeological Society of America (GSA), Vol. 15, No. 6, P. 563. (abstract.).GlobalMid Continent
DS1983-0206
1983
Dutch, S.I.Dutch, S.I.Proterozoic Structural Provinces in the North Central United States.Geology, Vol. 11, No. 8, PP. 478-481.United StatesMid-continent
DS1990-0436
1990
Dutch, S.I.Dutch, S.I.A possible geophysical signature of ancient terrane boundariesGeological Society of America (GSA) Abstract Volume, North-Central Section April, p. 9. abstractAppalachiaGeophysics -magnetics-gravity
DS200612-0357
2006
Dutch, S.I.Dutch, S.I.The Earth has a future. Geologic Time, process rates.Geosphere, Vol. 2, 3, pp. 113-124.TechnologyGeomorphology, tectonics, environment
DS1989-1218
1989
DuthouPillet, D., Bonhomme, M.G., Duthou, ChenevoyChronologie Rb-Sr et K-Ar du granite peralcalin du Lac Brisson, Labradorcentral.Canadian Journal of Earth Sciences, Vol. 26, pp. 328-32.Labrador, QuebecGeochronology
DS1900-0270
1904
Dutoit, A.L.Rogers, A.W., Dutoit, A.L.The Sutherland Volcanic Pipes and Their Relationship to Other Vents in South Africa.Phil. Soc. Sth. Afr. Transactions, Vol. 15, PT. 2, PP. 61-83. ALSO: ZEITSCHR. KRYST. (LEIPZIG)Africa, South AfricaDiatremes, Non-kimberlitic, Mineralogy
DS1900-0271
1904
Dutoit, A.L.Rogers, A.W., Dutoit, A.L.Geological Survey of Parts of Ceres, Sutherland and Calvinia. Volcanic Pipes of Sutherland.Cape of Good Hope Geol. Comm. 8th. Annual Report, 8TH. Annual Report, PP. 43-67.Africa, South AfricaRegional Geology, Kimberlite, Melilitite, Matzesfontein
DS1900-0354
1905
Dutoit, A.L.Rogers, A.W., Dutoit, A.L.The Volcanic Pipes of Sutherland, and Their Relation to The other Vents in South Africa.Phil. Soc. Sth. Afr. Transactions, Vol. 15, PP. 61-83. ZEITSCHR. KRYST. (LEIPZIG), Vol. 42, P.Africa, South AfricaRelated Rocks
DS1900-0403
1906
Dutoit, A.L.Dutoit, A.L.The Diamondiferous Gravels. In: Geological Survey of the East Portion of Griqualand West.Cape of Good Hope Geol. Comm. 11th. Annual Report, PP. 171-176.Africa, South AfricaRegional Geology, Alluvial Diamond Placers
DS1900-0547
1907
Dutoit, A.L.Dutoit, A.L.Pipe AmygdaloidsGeology Magazine (London), Vol. 44, PP. 13-17.Africa, South AfricaKimberlite, Genesis
DS1900-0548
1907
Dutoit, A.L.Dutoit, A.L.The Diamondiferous and Allied Pipes and FissuresCape of Good Hope Geol. Comm. 11th. Annual Report, PP. 135-170.Africa, South AfricaRegional Geology, Kimberlite Mines And Deposits
DS1900-0657
1908
Dutoit, A.L.Dutoit, A.L.Kimberlite and Allied Pipes and Fissure in Hopetown, Britstown, Prieska and Hay.Cape of Good Hope Geol. Comm. 12th. Annual Report, PP. 185-190.Africa, South AfricaRegional Geology, Kimberlite Mines And Deposits
DS1900-0747
1909
Dutoit, A.L.Dutoit, A.L.The Evolution of the River System of GriqualandRoyal Society. STH. AFR. Transactions, Vol. 1, PP. 347-361.Africa, South AfricaGeography, Alluvial Diamond Placers
DS1900-0748
1909
Dutoit, A.L.Dutoit, A.L.The Kimberlite and Allied Pipes and Fissures in Prieska, Britstown, Victoria West and Carnarvon.Cape of Good Hope Geol. Comm. 13th. Annual Report, PP. 111-127.Africa, South AfricaRegional Geology, Kimberlite Mines And Deposits
DS1900-0798
1909
Dutoit, A.L.Rogers, A.W., Dutoit, A.L.An Introduction to the Geology of the Cape ColonyLondon: Longmans, 491P.Africa, South AfricaKimberley, Geology, Regional
DS1910-0041
1910
Dutoit, A.L.Dutoit, A.L.The Diamond Bearing Blue Ground and Allied Rocks of South Africa.Edinburgh Geological Society Transactions, Vol. 9, PP. 361-362.South AfricaMineralogy, Geology
DS1910-0042
1910
Dutoit, A.L.Dutoit, A.L.Discussion of Paper by Wagner " the Origin of German South West African diamonds". #2Geological Society of South Africa Proceedings, Vol. 13, PP. XLIII-XLIV.Southwest Africa, NamibiaDiamond Genesis, Marine Diamond Placers
DS1910-0090
1910
Dutoit, A.L.Rogers, A.W., Dutoit, A.L.Kimberlite and Allied Pipes and Fissures in Carnarvon and Victoria West.Cape of Good Hope Geol. Comm. 14th. Annual Report, PP. 98-103.South AfricaRegional Geology, Kimberlite Mines And Deposits
DS1910-0274
1912
Dutoit, A.L.Dutoit, A.L.Geological Survey of the StormbergenCape of Good Hope Geol. Comm. 16th. Annual Report, PP. 121-136.South AfricaRegional Geology
DS1910-0347
1913
Dutoit, A.L.Dutoit, A.L.The Geology of Mount Currie and Umzimkulu (cape) and Alfred county (natal),union of South Africa.Geological Survey of South Africa 1ST. Annual Report, PT. 5, PP. 83-101.South AfricaRegional Geology
DS1910-0499
1916
Dutoit, A.L.Dutoit, A.L.Discussion on the Paper by Schwarz Entitled Diamonds from The Molteno Beds. #2Geological Society of South Africa Proceedings, Vol. 19, PP. XLII-XLIII.South Africa, Cape ProvinceAlluvial Diamond Placers
DS1920-0029
1920
Dutoit, A.L.Dutoit, A.L.The Karroo Dolerites of South Africa, a Study in Hypabyssalinjection.Geological Society of South Africa Proceedings, Vol. 23, PP. 1-42. ALSO: Geological Society of South Africa Proceedings, Vol. 23South Africa, Southwest Africa, NamibiaPetrology, Emplacement, Basaltic Rocks
DS1920-0281
1926
Dutoit, A.L.Dutoit, A.L.The Geology of South Africa (1926)Edinburgh: Oliver And Boyd., 463P.South AfricaGeology, Stratigraphy, Diamonds, Kimberley
DS1920-0331
1927
Dutoit, A.L.Dutoit, A.L.A Geological Comparison of South America with South Africa.with a Palaeontological Contribution by F.r. Cowper-reed.Carnegie Institute, No. 381, 158P.South Africa, South America, Southwest Africa, NamibiaPalaeontology, Tectonics, Continental Structure, Kimberley
DS1920-0378
1928
Dutoit, A.L.Dutoit, A.L.Some Reflections upon a Geological Comparison of South Africa with South America. Anniversary Address.Geological Society of South Africa Proceedings, Vol. 31, PP. XIX-XXXVIII. ALSO: Mining Engineering Journal of South Africa, VSouth AfricaTectonics, Continental Structure, Geology
DS1920-0379
1928
Dutoit, A.L.Dutoit, A.L.Discussion on a Paper by P.a. Wagner Entitled the Diamond Deposits on the Coast of Little Namaqualand.Geological Society of South Africa Proceedings, Vol. 31, PP. I-II.South Africa, Namaqualand CoastLittoral Diamond Placers, Genesis
DS1920-0441
1929
Dutoit, A.L.Dutoit, A.L.The Geology of the Major Portion of East Griqualand. an Explanation of Cape Sheet No. 35, Matatiele.Geological Survey of South Africa, MAP No. 35, 31P.South Africa, Cape ProvinceAlluvial Diamond Placers
DS1920-0442
1929
Dutoit, A.L.Dutoit, A.L., Rogers, A.W., Wagner, P.A.Kimberley (1929)International Geological Congress 15TH., GUIDEBOOK EXCURSION., No. AC., 34P.South Africa, Cape Province, Kimberley AreaGuidebook
DS1920-0449
1929
Dutoit, A.L.Houghton, S.H., Dutoit, A.L.Cape KimberlitesInternational Geological Congress 15TH., UNKNOWN.South Africa, Griqualand WestGeology
DS1930-0022
1930
Dutoit, A.L.Dutoit, A.L.Recent Diamond Prospecting in South AfricaEconomic Geology, Vol. 25, SEPT.-Oct. PP. 653-657.South AfricaCurrent Activities, Prospecting
DS1930-0023
1930
Dutoit, A.L.Dutoit, A.L.Diamonds; South Africa, 1930British Association Handbook On South Africa And Science, Crocker, PP. 127-147.South AfricaDiamond Occurrences, Geology, Genesis, Kimberley
DS1930-0104
1932
Dutoit, A.L.Dutoit, A.L.How the Kimberlite Pipes Serve to Reveal the UnknownEconomic Geology, Vol. 27, No. 2, PP. 206-210.South AfricaGeology, Genesis
DS1930-0136
1933
Dutoit, A.L.Dutoit, A.L.Crustal Movements As a Factor in the Geographical Evolution of South Africa.Geological Society of South Africa, Vol. 16, No. 3, PP.South AfricaTectonics
DS1930-0155
1934
Dutoit, A.L.Dutoit, A.L.A Discussion and Criticism of a Paper by Shand " the Heavy Minerals of Kimberlite".Geological Society of South Africa Proceedings, Vol. 37, PP. 64-67.South AfricaHeavy Minerals Concentrations
DS1930-0243
1937
Dutoit, A.L.Dutoit, A.L.Our Wandering ContinentsEdinburgh: Oliver And Boyd., 366P.South AfricaContinental Drift, Kimberley
DS1950-0062
1951
Dutoit, A.L.Dutoit, A.L.The Diamondiferous Gravels of LichtenburgSth. Afr. Geological Survey Memoir., No. 44, 58P. XEROX.South AfricaKimberlite, Kimberley, Janlib, Mineralogy
DS1950-0099
1952
Dutoit, A.L.Dutoit, A.L.Comparacao Geologica Entre a America Do Sul E a Africa Do Sul. Rev.Reio De Janeiro: Serv. Graf. Do Institute Bras. De Geograf. E Es, 179P.Brazil, South Africa, South AmericaKimberley, Tectonics
DS1950-0175
1954
Dutoit, A.L.Dutoit, A.L., Haughton, S.H.The Geology of South Africa (1954)Edinburgh: Oliver And Boyd., 611P. 3RD. EDITION.South AfricaKimberlite, Kimberley, Janlib, Geology
DS1950-0466
1959
Dutoit, G.J.Dutoit, G.J.William son Diamond MineMine And Quarry Eng., Vol. 25, APRIL, PP. 90-103; PP. 146-153.; MAY PP. 194-200.Tanzania, East AfricaMining Methods
DS1960-1095
1969
Dutoit, G.J.Dutoit, G.J.The Formative Years of the Mwadui Diamond MineMwadui Eng. Association Journal, Vol. 1, P. 12.Tanzania, East AfricaHistory
DS1987-0627
1987
Dutra, C.V.Ruberti, E., Gomes, C.B., Dutra, C.V.Geochemical aspects of alkaline mafics of Banhadao PR. Brasil. (in Portugese)National Technical Information Service DE 88704779, DE 88704779, 27p. $ 13.95BrazilAlkaline rocks
DS1994-0475
1994
Dutrow, B.Dutrow, B., Cash, T., Henry, D.Crystal chemistry of charoite: a product of intense metasomatic processesGeological Society of America (GSA) Abstract Volume, Vol. 26, No. 7, ABSTRACT only p. A481.RussiaCharoite, Little Murun alkaline
DS202003-0344
2019
Dutrow, B.L.Katsuke, Y., Sun, Z., Breeding, C.M., Dutrow, B.L.Geographic origin of Paraiba tourmaline.Gems & Gemology, Vol. 55, 4, pp. 648-659.South America, Braziltourmaline

Abstract: Vivid blue to green copper-bearing tourmalines, known as Paraíba tourmalines, are recovered from deposits in Brazil, Nigeria, and Mozambique. These tourmalines are sought after for their intense colors. Prices are based, in part, on the geographic origin of a stone, and determining provenance is thus an important aspect for Paraíba tourmaline. However, their geographic origin cannot be established by standard gemological testing and/or qualitative chemical analyses. GIA has established sophisticated criteria requiring quantitative chemical analyses to determine geographic origin for these tourmalines. These criteria were based on several hundred samples from known sources spanning the three countries. Highly accurate and precise quantitative elemental concentrations for Cu, Zn, Ga, Sr, Sn, and Pb are acquired with laser ablationinductively coupled plasmamass spectrometry (LA-ICP-MS). These data can then be plotted as a function of elemental concentration for accurate geographic origin determination.
DS1950-0130
1953
Dutt, N.V.B.S.Dutt, N.V.B.S.Ancient Diamond Mining in Andhra and Its FutureIndian Minerals, Vol. 7, No. 3, PP. 138-150.India, Andhra PradeshHistory
DS1960-0235
1962
Dutt, N.V.B.S.Dutt, N.V.B.S.Geology of the Kurnool SystemIndia Geological Survey Records, Vol. 87, No. 3, P. 576.India, Andhra PradeshStratigraphy
DS1982-0181
1982
Dutt, N.V.B.S.Dutt, N.V.B.S.Geology and Mineral Resources of Andhra Pradesh. Including Proterozoic Palaeogeography of Peninsular India.Hyderabad: Ramesh Printers, 205P.India, Andhra PradeshGeology, Resources, Economics
DS1986-0202
1986
Dutt, N.V.B.S.Dutt, N.V.B.S.Geology and mineral resources of Andhra PradeshIndia Department Natural Resources Cooperative Society Hyderaba, 432p. 41 tables 5 figures 6 mapsIndiaDiamond
DS1989-1369
1989
Dutta, A.Sen Gupta, S., Dutta, A., Bandopadhyay, R.Ultra-potassic rock from Raniganj coalfieldIndian Minerals, Vol. 43, No. 1, January-March pp. 19-24IndiaLamproite -Ultra-potassic, Alkaline rocks
DS2003-0861
2003
Dutta, P.Mahatha, S., Dutta, P.Incorporating cumulative impact concerns into EIAsMining Environmental Management, Vol. 11, 2, March pp. 16-21.GlobalCheck list, Environmental - example coal project
DS200412-1200
2003
Dutta, P.Mahatha, S., Dutta, P.Incorporating cumulative impact concerns into EIAs.Mining Environmental Management, Vol. 11, 2, March pp. 16-21.GlobalCheck list Environmental - example coal project
DS202205-0679
2022
Dutta, R.Dutta, R., Tracy, S.J., Cohen, R.E. , Miozzi, F., Luo, K., Yang, J., Burnley, P.C., Smith, D., Meng, Y., Chariton, S., Prakapenka, V.B., Duffy, T.S.Ultrahigh-presssure disordered eight-coordinated phase of Mg2GeO4: analogue for super Earth mantles. GermaniumPNAS, https://doi.org/10.1073/pnas.2114424119Mantlegeodynamics

Abstract: Mg2GeO4 is important as an analog for the ultrahigh-pressure behavior of Mg2SiO4, a major component of planetary interiors. In this study, we have investigated magnesium germanate to 275 GPa and over 2,000 K using a laser-heated diamond anvil cell combined with in situ synchrotron X-ray diffraction and density functional theory (DFT) computations. The experimental results are consistent with the formation of a phase with disordered Mg and Ge, in which germanium adopts eightfold coordination with oxygen: the cubic, Th3P4-type structure. DFT computations suggest partial Mg-Ge order, resulting in a tetragonal I4Ż2d structure indistinguishable from I4Ż3d Th3P4 in our experiments. If applicable to silicates, the formation of this highly coordinated and intrinsically disordered phase may have important implications for the interior mineralogy of large, rocky extrasolar planets.
DS201412-0660
2013
Dutta, S.Pandev, O.P., Srivastava, R.P., Vedanti, N., Dutta, S., Dimri, V.P.Anomalous crustal and lithospheric mantle structure of southern part of the Vindhyan Basin and its geodynamic implications.Journal of Asian Earth Sciences, Vol. 91, pp. 316-328.IndiaGeophysics - seismics
DS202009-1624
2020
Dutton, S.E.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.
DS201907-1550
2019
Duuring, P.Holden, E-J., Liu, W., Horrocks, T., Wang, R., Wedge, D., Duuring, P., Beardsmore, T.GeoDocA - fast analysis of geological content in mineral exploration reports: a text mining approach. Not specific to diamondOre Geology Reviews, in press available, 20p.AustraliaAnalysis system
DS1860-0378
1882
Duval, C.Duval, C.With a Show through South Africa and Personal Reminiscences of the Transvaal War.London: Tinsley Bros., TWO VOLUMES.Africa, South Africa, Cape ProvinceTravelogue
DS1996-0563
1996
Duval, D.Green, T., Duval, D., Louthean, R.New frontiers in diamondsDuval Minecom, 416 470 Granville Street, Vancouver BC., 604 669-1493 Fax $ 65.00 inc. P and HGlobalBook, Anecdotes, diamond industry, companies, areas of intere
DS1993-1235
1993
Duval, J.S.Phillips, J.D., Duval, J.S., Ambroziak, R.A.National geophysical dat a and topographic dat a for the conterminous USAUnited States Geological Survey (USGS), DDS-0009, 1 disc. $ 32.00United StatesGeophysics, CD-ROM datafile
DS1999-0185
1999
Duval, J.S.Duval, J.S., Riggle, F.E.Profiles of gamma ray and magnetic dat a from aerial surveys over the conterminous United States.United States Geological Survey (USGS) CD RoM., DDS 0031, 3 cd-roms, $ 52.00United StatesGeophysics - gamma, magnetics
DS201710-2219
2017
Duvbovinsky, L.Cerantola, V., Bykova, E., Kupenko, I., Merlini, M., Ismailova, L., McCammon, C., Bykov, M., Chumakov, A.I., Petitgirard, S., Kantor, I., Svityk, V., Jacobs, J., Hanfland, M., Mezouar, M., Prescher, C., Ruffer, R., Prakapenka, V.B., Duvbovinsky, L.How iron carbonates help form diamonds.Nature Communications, July 18 #15960Mantlecarbonate inclusions
DS1981-0300
1981
Duvenhage, A.W.A.Meyer, R., Duvenhage, A.W.A.A Regional Gravity Survey of Part of the North Western Capeprovince.Geological Society of South Africa Transactions, Vol. 84, No. 1, P. 85. (abstract.).South AfricaRegional Tectonics, Geophysics
DS2001-1133
2001
Duyster, J.Stockhert, B., Duyster, J., Trepmann, C., Massonne, HJ.Microdiamond daughter crystals precipitated from supercritical COH + silicate fluids included garnet...Geology, Vol. 29, No. 5, May, pp. 391-4.GermanyDiamond, ultra high pressure (UHP), metamorphism, Erzgebirge area
DS200812-0305
2008
Dvir, O.Dvir, O., Kessel, R.The character and composition of fluid in equilibrium with peridotite in subduction zones.Goldschmidt Conference 2008, Abstract p.A234.MantleSubduction
DS201112-0293
2011
Dvir, O.Dvir, O., Pettke, T., Fumagalli, P., Kessel, R.Fluids in the peridotite water system up to 6GPa and 800 degreesC: new experimental constrains on dehydration reactions.Contributions to Mineralogy and Petrology, Vol. 161, 6, pp. 829-844.MantleWater
DS201212-0176
2012
Dvir, O.Dvir, O., Angert, A., Kessel, R.Determining the composition of C-H-O liquids following high-pressure and high-temperature diamond-trap experiments.Contributions to Mineralogy and Petrology, in press available 7p.TechnologyMantle, HP
DS201312-0233
2013
Dvir, O.Dvir, O., Angert, A., Kessel, R.Determining the composition of C-H-O liquids following high pressure and high temperature diamond trap experiments.Contributions to Mineralogy and Petrology, Vol. 165, 3, pp. 593-599.MantleUHP
DS201312-0148
2013
Dvoichenkova, G.P.Chanturia, V.A., Bogachev, V.I., Trofimova, E.A., Dvoichenkova, G.P.Mechanism and efficiency of water based removal of grease from diamonds during grease seperation.Journal of Mining Science, Vol. 48, 3, pp. 559-564.Russia, YakutiaDeposit - Mir
DS201504-0193
2014
Dvoichenkova, G.P.Dvoichenkova, G.P.Mineral formations on natural diamond surface and their destruction using electrochemically modified mineralized water.Journal of Mining Science, Vol. 50, 4, pp. 788-799.TechnologyDiamond morphology - surfaces
DS201510-1765
2014
Dvoichenkova, G.P.Dvoichenkova, G.P.Mineral formations on natural diamond surface and their destruction using electrochemically modified mineralized water.Journal of Mining Science, Vol. 50, 4, pp. 788-799.TechnologyDiamond morphology

Abstract: The article describes modeling and analysis of formation, attachment and dissolving of mineral substances on surface of diamond crystals. Based on the thermodynamic analysis and experimental research, the author validates deposition of chemical compounds as the main factor to govern mineral formations on natural diamond surface under contact with mineralized water in the occurrence conditions of kimberlite ore and during mining and processing. The efficiency of electrochemically modified water in dissolving and removal of mineral formations from diamond surface is ascertained.
DS201611-2100
2015
Dvoichenkova, G.P.Chanturia, V.A., Dvoichenkova, G.P., Kovalchuk, O.E., Timofeev, A.S.Surface composition and role of hydrophilic diamonds in foam separation.Journal of Mining Science , Vol. 51, 5, pp. 1235-1241.RussiaMineral processing ** in Russian

Abstract: The article presents new test results on structural and chemical properties of mineral formations on the surface of natural hydrophilic diamonds using Raman, X-ray phase and Auger spectroscopy methods. Analysis of morphological features of nano formations involved scanning electron microscope Jeol-5610 and analyzer INCA. Based on the studies into phase composition of diamonds non-recovered in the circuit of kimberlite ore processing, two types of mineral formations are discovered on their surface: microformations as silicate nature globules less than 1 ?m in size and silicate nano films more than 5 nm thick. The tests detect also presence of layered talc silicates that make diamond surface hydrophilic.
DS201701-0005
2016
Dvoichenkova, G.P.Chanturia, V.A., Bunin, I.Zh., Dvoichenkova, G.P., Kovalchuk, O.E.Low temperature effects to improve efficiency of photoluminescence separation of diamonds in kimberlite ore processing.Journal of Mining Science, Vol. 52, no. 2, pp. 332-340.Russia, YakutiaDeposit - Mir

Abstract: The article gives new experimental data on spectral characteristics of photoluminescence of natural diamonds extracted from deep horizons of Mir and Internatsionalnaya Pipes, Republic of Sakha (Yakutia) depending on composition of basic and additional optically active structural defects in crystals and on temperature during spectrum recording, considering kinetics of luminescence. It is hypothesized on applicability of low-temperature effects to enhance efficiency of photoluminescence separation of diamond crystals.
DS201702-0203
2016
Dvoichenkova, G.P.Chanturia, V.A., Bunin, I.Zh., Dvoichenkova, G.P., Kovalchuk, O.E.Low temperature effects to improve effeciency of photoluminescence separation of diamonds in kimberlite ore processing.Journal of Mining Science, Vol. 52, 2, pp. 332-340.TechnologySpectroscopy

Abstract: The lithosphere beneath the Western Canada Sedimentary Basin has potentially undergone Precambrian subduction and collisional orogenesis, resulting in a complex network of crustal domains. To improve the understanding of its evolutionary history, we combine data from the USArray and three regional networks to invert for P-wave velocities of the upper mantle using finite-frequency tomography. Our model reveals distinct, vertically continuous high (> 1%) velocity perturbations at depths above 200 km beneath the Precambrian Buffalo Head Terrane, Hearne craton and Medicine Hat Block, which sharply contrasts with those beneath the Canadian Rockies (
DS201705-0817
2016
Dvoichenkova, G.P.Chanturia, V.A., Dvoichenkova, G.P., Kovalchuk, O.E.Classification of mineral species on the surface of natural diamond crystals.Journal of Mining Science, Vol. 52, 3, pp. 535-540.RussiaDiamond morphology

Abstract: The analytical research has yielded differences in composition of mineral species on the surface of natural diamonds of hyperaltered kimberlites under conditions of diamond ore occurrence and processing. The classification of the mineral species is based on the mineral origin, properties and attachment on the diamond crystal surface.
DS201705-0818
2015
Dvoichenkova, G.P.Chanturia, V.A., Dvoichenkova, G.P., Kovalchuk, O.E.Surface properties of diamonds recovered from metasomatically modified kimberlites duing processing.Journal of Mining Science, Vol. 51, 2, pp. 353-362.RussiaDiamond morphology
DS201705-0819
2015
Dvoichenkova, G.P.Chanturia, V.A., Dvoichenkova, G.P., Kovalchuk, O.E., Timofeev, S.A.Surface composition and role of hydrophillic diamonds in foam seperation.Journal of Mining Science, Vol. 51, 6, pp. 1235-1241.RussiaDiamond morphology

Abstract: The article presents new test results on structural and chemical properties of mineral formations on the surface of natural hydrophilic diamonds using Raman, X-ray phase and Auger spectroscopy methods. Analysis of morphological features of nano formations involved scanning electron microscope Jeol-5610 and analyzer INCA. Based on the studies into phase composition of diamonds non-recovered in the circuit of kimberlite ore processing, two types of mineral formations are discovered on their surface: microformations as silicate nature globules less than 1 ?m in size and silicate nano films more than 5 nm thick. The tests detect also presence of layered talc silicates that make diamond surface hydrophilic.
DS201804-0679
2017
Dvoichenkova, G.P.Chanturia, V.A., Ryazantseva, M.V., Dvoichenkova, G.P., Minenko, V.G., Koporulina, E.V.Surface modification of rock forming minerals of diamond bearing kimberlites under interaction with wastewater and electrochemically treated water.Journal of Mining Science, Vol. 53, 1, pp. 126-132.Russiadeposit - Mir

Abstract: The structural and chemical surface transformation of basic kimberlite-forming minerals (calcite, olivine, serpentine) under the contact with natural and waste mineralized water and products of electrochemical treatment of the water are studied using X-ray photoelectronic spectroscopy, scanning electron microscopy and X-ray spectral micro-analysis, and atomic force microscopy. It is found that contact with kimberlite extract and recycling water induces chemical modification of calcite surface, which consists in adsorption of hydrocarbon impurities, and chlorine- and silica-bearing compounds, majority of which are removed during interaction with the product of electrochemical treatment of recycling water. The change in the structural and chemical surface properties of rock-forming silicates, aside from adsorption-desorption of organic compound, is also connected with the distortion of nano-size layer structure after leaching of Mg, Fe and Si, and with the carbonatization of the surface.
DS201906-1283
2018
Dvoichenkova, G.P.Chanturia, V.A., Dvoichenkova, G.P., Morozov, V.V., Kovalchuk, O.E., Podkamenny, Y.A., Yakolev, V.N.Experimental justification of luminophore composition for indication of diamonds in x-ray luminescence separation of kimberlite ore.Journal of Mineral Science, Vol. 54, 3, pp. 458-465.Russialuminescence

Abstract: Organic and inorganic luminophores of similar luminescence parameters as diamonds are selected. Indicators, based on the selected luminophores, are synthesized. Spectral and kinetic characteristics of luminophores are experimentally determined for making a decision on optimal compositions to ensure maximum extraction of diamonds in X-ray luminescence separation owing to extra recovery of non-luminescent diamond crystals. As the components of luminophore-bearing indicators, anthracene and K-35 luminophores are selected as their parameters conform luminescence parameters of diamonds detected using X-ray luminescence separator with standard settings.
DS202007-1128
2020
Dvoichenkova, G.P.Chanturia, V.A., Dvoichenkova, G.P., Morozov, V.V., Kovalchuk, O.E., Pdkamennyi, Yu.A., Yakovlev, V.N.Selective attachment of luminophore bearing emulsion at diamonds - mechanism analysis and mode selection. X-rayJournal of Mining Science, Vol. 56, 1, pp. 96-103. pdfGloballuminescence

Abstract: The authors present an efficient modification method of X-ray fluorescence separation with mineral and organic luminophores used to adjust spectral and kinetic characteristics of anomalously luminescent diamonds. The mechanism of attachment of luminophores at diamonds and hydrophobic minerals is proved, including interaction between the organic component of emulsions and the hydrophobic surface of a treated object and the concentration of insoluble luminophore grains at the organic and water interface. Selective attachment of the luminophore-bearing organic phase of emulsion at the diamond surface is achieved owing to phosphatic dispersing agents. Tri-sodium phosphate and sodium hexametaphosphate added to emulsion reduce attachment of the luminophore-bearing organic phase at the surface of kimberlite minerals. It is shown that phosphate concentration of 1.0-1.5 g/l modifies and stabilizes spectral and kinematic parameters of kimberlite mineral on the level of initial values. This mode maintains the spectral and kinematic characteristics of anomalously luminescent diamonds at the wanted level to ensure extraction of diamonds to concentrate.
DS202111-1761
2020
Dvoichenkova, G.P.Chanturia, V.A., Dvoichenkova, G.P., Morozov, V.V., Kovalchuk, O.E., Podkamennyi, Yu.A., Yakolev, V.N.Selective attachment of luminophore-bearing emulsion at diamonds - mechanism analysis and mode selection.Journal of Mining Science, Vol. 56, 1, pp. 96-103, 8p. PdfRussialuminescence

Abstract: The authors present an efficient modification method of X-ray fluorescence separation with mineral and organic luminophores used to adjust spectral and kinetic characteristics of anomalously luminescent diamonds. The mechanism of attachment of luminophores at diamonds and hydrophobic minerals is proved, including interaction between the organic component of emulsions and the hydrophobic surface of a treated object and the concentration of insoluble luminophore grains at the organic and water interface. Selective attachment of the luminophore-bearing organic phase of emulsion at the diamond surface is achieved owing to phosphatic dispersing agents. Tri-sodium phosphate and sodium hexametaphosphate added to emulsion reduce attachment of the luminophore-bearing organic phase at the surface of kimberlite minerals. It is shown that phosphate concentration of 1.0-1.5 g/l modifies and stabilizes spectral and kinematic parameters of kimberlite mineral on the level of initial values. This mode maintains the spectral and kinematic characteristics of anomalously luminescent diamonds at the wanted level to ensure extraction of diamonds to concentrate.
DS202111-1776
2021
Dvoichenkova, G.P.Morozov, V.V., Dvoichenkova, G.P., Kovalenko, E.G., Chanturia, E.L., Chernysheva, E.N.The mechanism and parameters of froth flotation stimulation for diamond-bearing materials by thermal and electrochemical effects.Journal of Mining Science, Vol. 57, 2, pp. 286-297. pdfRussiaIPKON RAS

Abstract: The thermodynamic analysis and tests of minerogenesis under higher temperatures determine conditions of thermochemical decomposition of hydrophilic attachments on diamond surface. It is found that hydrophilic mineral attachments can be removed from diamond surface by combining thermal treatment of slurry at the temperature of 80-85 ?C with electrochemical treatment of recirculated water, which enables required change in ion-molecule composition of water phase in the slurry. The hybrid conditioning technology ensures recovery of the natural hydrophobic behavior and floatability of diamonds and enhances performance of froth flotation of diamonds by 5.1%.
DS1990-0437
1990
Dvorachek, M.Dvorachek, M., Rosenfeld, A., Honigstein, A.Contamination of geological samples in scanning electron microscopyNeues Jahrb, No. 12, pp. 707-716GlobalMicroscopy, Review
DS200612-0358
2006
Dwarzski, R.E.Dwarzski, R.E., Draper, D.A., Shearer, C.K., Agee, C.B.Experimental insights on crystal chemistry of high Ti garnets from garnet melt partitioning of rare earth and high field strength elements.American Mineralogist, Vol. 91, 9, pp. 1536-1546.TechnologyPetrology - crystal chemistry
DS200812-0842
2008
Dwivedi, M.M.Pandey, K., Dwivedi, M.M.Natural and fancy diamonds: synthesis and characterization techniques.Proceedings of National Academy of Sciences India , Vol. 78, 3, pp. 231-236. Ingenta art1083898765IndiaTechnology
DS1995-1660
1995
Dwivedy, K.K.Sarkar, S.C., Dwivedy, K.K., Das, A.K.Rare earth deposits in India - an outline of their types, distribution, mineralogy geochemistry genesis.Global Tectonics and Metallogeny, Vol. 5, No. 1-2, Oct. pp. 53-61.IndiaCarbonatite, rare earth elements (REE)., Deposits -list
DS1996-0795
1996
Dwivedy, K.K.Kumar, D., Mamallan, R., Dwivedy, K.K.Carbonatite magmatism in northeast IndiaJournal of Southeast Asian Earth Sciences, Vol. 13, No. 2, Feb. 1, pp. 145-?IndiaCarbonatite, Magmatism
DS1985-0162
1985
Dworkin, S.I.Dworkin, S.I., et al.Late Wisconsi nan ice flow reconstruction for the central Great Lakesregion.Canadian Journal of Earth Sciences, Vol. 22, pp. 935-40.Ontario, Michigan, WisconsinGeomorphology
DS1986-0226
1986
Dwornik, E.J.Evans, H.T., Dwornik, E.J., Milton, C.Kassite from the Diamond Jo Quarry, Magnet Cove, Hot SpringCounty, Arkansaw- the problem of cafetite and kassiteAmerican MIneralogist, Vol. 71, No. 7-8, July-August pp. 1045-1048ArkansasMineralogy
DS1975-0992
1979
Dwson, J.B.Delaney, J.S., Smith, J.V., Dwson, J.B., Nixon, P.H.Manganese Thermometer for Mantle PeridotitesContributions to Mineralogy and Petrology, Vol. 71, pp. 157-69.South AfricaGeothermometry
DS1989-0381
1989
Dyack, B.J.Dyack, B.J.The impact of the proposed goods and services tax on the Canadian MiningIndustryCentre for Resource Studies, CRS Perspectives, No. 31, November 4p. Database # 18220CanadaMining issues, Legal -taxation
DS200612-1173
2005
Dyakonov, D.B.Romanko, E.F., Egorov, N.N., Podvysotskii, V.T., Sablukov, S.M., Dyakonov, D.B.A new Diamondiferous kimberlite region in southwestern Angola.Doklady Earth Sciences, Vol. 403A, 6, pp. 817-821.Africa, AngolaDiamond exploration
DS200712-0286
2007
Dyakonov, D.B.Egorov, K.N., Ramnko, E.F., Podvysotsky, V.T., Sabulukov, S.M., Garanin, V.K., Dyakonov, D.B.New dat a on kimberlite magmatism in southwestern Angola.Russian Geology and Geophysics, Vol. 48, 4, pp. 323-336.Africa, AngolaMagmatism - kimberlites
DS201212-0177
2012
Dyakonov, D.B.Dyakonov, D.B., Garanin, VK., Garanin, K.V., Bushueva, E.B., Enalieva, M.A., Wedensky, E.S.Searching for new diamond deposits in western Liberia.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractAfrica, LiberiaProspects - Yambassen, Kumgbo
DS200912-0193
2009
Dyakonova, A.G.Dyakonova, A.G., Ivanov, K.S., Surina, O.V., Asafev, P.F., Vishnev, V.S., Konoplin, A.D.The structure of the tectonosphere of the Urals and West Siberian platform by electromagnetic data.Doklady Earth Sciences, Vol. 423, 3-6, pp. 1479-1481.RussiaGeophysics - EM
DS200912-0194
2008
Dyakonova, A.G.Dyakonova, A.G., Ivanov, K.S., Surina, O.V., Astafev, P.F., Vishnev, V.S., Konoplin, A.D.The structure of the tectonosphere of the Urals and West Siberian Platform by electromagnetic data.Doklady Earth Sciences, Vol. 423A, No. 9, pp. 14791482.Russia, SiberiaGeophysics
DS1986-0311
1986
Dyakov, A.G.Gritsik, V.V., Dyakov, A.G.Geochemical aspects of the crystal morphology of diamond.(Russian)Mineral. Kristallogr. I EE Prim. V. Prakt. Geol. Kiev (Russian), Vol. 1986 pp. 132-134RussiaBlank
DS1988-0274
1988
Dyakov, A.G.Gritsik, V.V., Dyakov, A.G., Poberezhskiy, V.A.Carbon isotope composition of diamonds from different diamond bearing provinces of the world.(Russian)Mineral. Sbornik (L'Vov), (Russian), Vol. 42, No. 1, pp. 68-70Russia, GlobalGeochronology, Diamonds, Carbon isotope
DS1989-0382
1989
Dyar, M.D.Dyar, M.D., McGuire, A.V.Crystal chemistry of clinopyroxene from mantle xenolithsGeological Society of America (GSA) Annual Meeting Abstracts, Vol. 21, No. 6, p. A240. AbstractCaliforniaMantle, Dish Hill
DS1989-0383
1989
Dyar, M.D.Dyar, M.D., McGuire, A.V., Ziegler, R.D.Redox equilibration temperatures and crystal chemistry of coexisting minerals from spinel lherzolite mantle xenolithsAmerican MIneralogist, Vol. 74, No. 9-10, September-October pp. 969-980California, Arizona, New Mexico, Saudi ArabiaLherzolite, Mantle xenoliths
DS1989-0987
1989
Dyar, M.D.McGuire, A.V., Dyar, M.D., Ward, K.A.Neglected Fe3+/Fe2+ ratios- a study of Fe3+ content of megacrysts from alkali basaltsGeology, Vol. 17, No. 8, August pp. 687-690GlobalMantle xenoliths, Petrology
DS1991-0672
1991
Dyar, M.D.Harrell, M.D., Dyar, M.D., McGuire, A.V.Redox behaviour of metasomatism in a composite xenolithGeological Society of America Annual Meeting Abstract Volume, Vol. 23, No. 5, San Diego, p. A 272New MexicoXenoliths, Spectroscopy, Kilbourne Hole
DS1991-1108
1991
Dyar, M.D.McGuire, A.V., Dyar, M.D., Nielson, J.E.Metasomatic oxidation of upper mantle peridotiteContributions to Mineralogy and Petrology, Vol. 109, No. 2, pp. 252-264MantleMantle oxidation, Peridotite
DS1992-0074
1992
Dyar, M.D.Banfields, J.F., Dyar, M.D., McGuire, A.V.The defect microstructure of oxidized mantle olivine from Dish HillCaliforniaAmerican Mineralogist, Vol. 77, No. 9-10, September-October pp. 977-986CaliforniaXenoliths, Mantle
DS1992-0075
1992
Dyar, M.D.Banfields, J.F., Dyar, M.D., McGuire, A.V.The defect structure of oxidized mantle olivine from Dish Hill, CaliforniaAmerican Mineralogist, Vol. 77, pp. 977-86.CaliforniaMetasomatism - mantle
DS1992-0405
1992
Dyar, M.D.Dyar, M.D., McGuire, A.V., Mackwell, S.J.Fe3/H and D/H in kaersutites- misleading indicators of mantle sourcefugacitiesGeology, Vol. 20, No. 6, June pp. 565-568GlobalMantle, iron, Hydrogen, Geochronology
DS1993-0385
1993
Dyar, M.D.Dyar, M.D., Mackwell, S.J., Cross, L.R., Robertson, J.D.Crystal chemistry of iron and Hydrogen in mantle kaersutite: implications for mantle MetasomatismAmerican Mineralogist, Vol. 78, No. 9, 10, September-October pp. 968-979MantleMetasomatism, iron, Hydrogen, Geochemistry
DS1995-0467
1995
Dyar, M.D.Dyar, M.D., Martin, S.V., et al.iron III and D/H in mantle derived augite megacrysts from Dish Hill, implications for alteration during transportGeological Society of America (GSA) Abstracts, Vol. 27, No. 6, abstract p. A 48.CaliforniaSpectroscopy, Hydrogen, Deposit -Dish Hill
DS2000-0501
2000
Dyar, M.D.King, P.L., Hervig, R.L., Dyar, M.D.Partitioning of Fe3 iron total between amphibole and basanitic melt as a function of oxygen fugacity.Earth and Planetary Science Letters, Vol. 178, No. 1-2, May 15, pp. 97-112.GlobalBasanite
DS1998-0354
1998
Dyatlov, V.L.Dmitriev, A.N., Dyatlov, V.L., Litasov, K.D.Physical model of kimberlite pipes formation: new constraints theory of non-homogenous physical vacuuM.7th International Kimberlite Conference Abstract, pp. 196-8.RussiaNon-homogenous vacuum ( NPV), Emplacement model
DS2001-1125
2001
DyckStasiuk, L.D., Sweet, A.R., Hamblin, Issler, Dyck, KiviUpdate on multidisciplinary study of sedimentary cover sequence Lac de Gras kimberlite field.29th. Yellowknife Geoscience Forum, Nov. 21-23, abstract p. 81.Northwest TerritoriesPetrology - geochemistry, Lac de Gras field
DS202111-1779
2021
Dyck, B.Niyazova, S., Kopylova, M., Dyck, B., Benisek, A., Dachs, E., Stefano, A.The assimilation of felsic xenoliths in kimberlites: insights into temperature and volatiles during kimberlite emplacement. ( Renard)Contributions to Mineralogy and Petrology, Vol. 176, 10, 28p. PdfCanada, Quebecdeposit - Renard

Abstract: This study aims to constrain the nature of kimberlite-xenolith reactions and the fluid origin for Kimberley-type pyroclastic kimberlite (KPK). KPKs are characterized by an abundance of basement xenoliths (15-90%) and display distinct pipe morphology, textures, and mineralogy. To explain the KPK mineralogy deviating from the mineralogy of crystallized kimberlite melt, we study reactions between hypabyssal kimberlite transitional to KPK and felsic xenoliths. Here, we characterize the pectolite-diopside-phlogopite-serpentine-olivine common zonal patterns using petrography, bulk composition, thermodynamic modelling, and conserved element ratio analysis. To replicate the observed mineral assemblages, we extended the thermodynamic database to include pectolite, using calculated density functional theory methods. Our modelling reproduces the formation of the observed distinct mineralogy in reacted granitoid and gneiss. The assimilation of xenoliths is a process that starts from high temperatures (1200-600 °C) with the formation of clinopyroxene and wollastonite, continues at 600-200 °C with the growth of clinopyroxene, garnet, and phlogopite finishing at temperatures?
DS2003-0988
2003
Dyck, D.Mustafa, J., Nowicki, T.E., Oshust, P., Dyck, D., Crawford, B., Harrison, S.The geology of the Misery kimberlite, Ekati diamond mine, Canada8ikc, Www.venuewest.com/8ikc/program.htm, Session 1 POSTER abstractNorthwest TerritoriesKimberlite geology and economics, Deposit - Misery
DS2003-1021
2003
Dyck, D.Nowicki, T.E., Crawford, B., Dyck, D., Carlson, J., McElroy, R., Helmstaedt, H.A review of the geology of kimberlite pipes of the Ekati property, Northwest8 Ikc Www.venuewest.com/8ikc/program.htm, Session 1, AbstractNorthwest TerritoriesGeology, Deposit - Ekati
DS200412-1450
2003
Dyck, D.Nowicki, T.E., Crawford, B., Dyck, D., Carlson, J., McElroy, R., Helmstaedt, H., Oshust, P.A review of the geology of kimberlite pipes of the Ekati property, Northwest Territories, Canada8 IKC Program, Session 1, AbstractCanada, Northwest TerritoriesGeology Deposit - Ekati
DS200612-0892
2006
Dyck, D.McElroy, R., Nowicki, T., Dyck, D., Carlson, J., Todd, J., Roebuck, S., Crawford, B., Harrison, S.The geology of the PAnd a kimberlite Ekati mine, Canada.Emplacement Workshop held September, 5p. extended abstractCanada, Northwest TerritoriesDeposit - Panda geology
DS200612-0956
2006
Dyck, D.Mustafa, J., Norwicki, T., Oshust, P., Dyck, D., Crawford, B., Harrison, S.The geology of the Misery kimberlite, Ekati diamond mine, Canada.Emplacement Workshop held September, 5p. abstractCanada, Northwest TerritoriesDeposit - Misery
DS200812-0248
2007
Dyck, D.Coutts, B., Heimbach, J., Dyck, D.Panda, from pyrope to production ( now you've found a kimberlite, the work is just starting). BHP Billiton35th. Yellowknife Geoscience Forum, Abstracts only p. 11-12.Canada, Northwest TerritoriesMine planning - Panda
DS2003-1327
2003
Dyck, D.D.Stasiuk, L.D., Sweet, A.R., Issler, D.R., Kivi, K., Lockhart, G., Dyck, D.D.Pre and post kimberlite emplacement thermal history of Cretaceous and Tertiary8ikc, Www.venuewest.com/8ikc/program.htm, Session 1 POSTER abstractNorthwest TerritoriesKimberlite geology and economics, Geothermometry
DS1998-1064
1998
Dyck, D.R.Nassiuk, W.W., Dyck, D.R.Fossils recovered from kimberlite pipes in the Lac de Gras field, Slave Province - geological indicators.7th International Kimberlite Conference Abstract, pp. 612-14.Northwest TerritoriesPaleontology, Deposit - Point Lake, Nancy, Sue
DS2001-0284
2001
Dyck, D.R.Dyck, D.R., Carlson, J.A.The geology of the Ekati diamond mine, Lac de Gras Northwest TerritoriesNw Mining Association Meet., Dec. 7, 1p. abstr.Northwest TerritoriesNews item, Ekati
DS2002-0409
2002
Dyck, D.R.Dyck, D.R., Carlson, J.Kimberlite geology of the Ekati Diamond Mine, Lac de Gras, Northwest TerritoriesGac/mac Annual Meeting, Saskatoon, Abstract Volume, P.31., p.31.Northwest TerritoriesBrief - overview, Deposit - Ekati
DS2002-0410
2002
Dyck, D.R.Dyck, D.R., Carlson, J.Kimberlite geology of the Ekati Diamond Mine, Lac de Gras, Northwest TerritoriesGac/mac Annual Meeting, Saskatoon, Abstract Volume, P.31., p.31.Northwest TerritoriesBrief - overview, Deposit - Ekati
DS2003-0359
2003
Dyck, D.R.Dyck, D.R., Oshust, P.A., Carlson, J.A., Mullins, M.P.Effective resource estimates for primary diamond deposits - Ekati diamond mine8 Ikc Www.venuewest.com/8ikc/program.htm, Session 1, AbstractNorthwest TerritoriesEconomic - resources, Deposit - Ekati
DS2003-0538
2003
Dyck, D.R.Hamblin, A.P., Stasiuk, L.D., Sweet, L.D., Lockhart, G., Dyck, D.R., Jagger, K.Post kimberlite Eocene strat a in Crater Basin, Lac de Gras, Northwest Territories8ikc, Www.venuewest.com/8ikc/program.htm, Session 1 POSTER abstractNorthwest TerritoriesKimberlite geology and economics, Stratigraphy
DS2003-0911
2003
Dyck, D.R.McElroy, R.E., Nowicki, T.E., Dyck, D.R., Carlson, J.A., Todd, J.K., RoebuckThe geology of the PAnd a kimberlite, Ekati diamond mine, Canada8ikc, Www.venuewest.com/8ikc/program.htm, Session 1 POSTER abstractNorthwest TerritoriesKimberlite geology and economics, Deposit - Panda
DS200412-0493
2003
Dyck, D.R.Dyck, D.R., Oshust, P.A., Carlson, J.A., Mullins, M.P.Effective resource estimates for primary diamond deposits - Ekati diamond mine, Canada.8 IKC Program, Session 1, AbstractCanada, Northwest TerritoriesEconomic - resources
DS200412-0753
2004
Dyck, D.R.Gurney, J.J., Hildebrand, P.R., Carlson, J.A., Fedortchouk, Y., Dyck, D.R.The morphological characteristics of diamonds from the Ekati property, Northwest Territories, Canada.Lithos, Vol. 77, 1-4, Sept. pp. 21-38.Canada, Northwest TerritoriesDiamond morphology, colour
DS201312-0877
2013
Dye, S.T.Sramek, O., McDonough, W.F., Kite, E.S., Lekic, V., Dye, S.T., Zhong, S.Geophysical and geochemical constraints on geoneutrino fluxes from Earth's mantle.Earth and Planetary Science Letters, Vol. 361, pp. 356-366.MantleTomography
DS201212-0107
2012
Dyer, A.Campbell, I.S., Dyer, A., Williams, C., Lythgoe, P.R.The masquerade of alkaline carbonatitic tuffs by zeolites: a new global pathfinder hypothesis.Mineralium Deposita, in press available 12p.GlobalAlkaline rocks, magmatism
DS201212-0108
2012
Dyer, A.Campbell, L.S., Dyer, A., Williams, C., Lythgoe, P.R.The masquerade of alkaline-carbonatite tuffs by zeolites: a new global pathfinder hypothesis.Mineralium Deposita, Vol. 47, 4, pp. 371-382.MantleMagmatism - carbonatite
DS201312-0119
2013
Dyer, A.Campbell, L.S., Dyer, A., Williams, C., Lythgoe, P.R.Exploring the preservation of alkaline carbonatitic extrusive rocks in relation to continent formation.Goldschmidt 2013, AbstractMantleMineral reaction paths
DS201312-0120
2013
Dyer, A.Campbell, L.S., Dyer, A., Williams, C., Lythgoe, P.R.Alkaline-carbonatitic extrusive rocks in relation to continent formation.Goldschmidt 2013, AbstractMantleZeolite masquerade
DS1994-0476
1994
Dyer, B.C.Dyer, B.C., Fawcett, A.The use of tomographic imaging in mineral explorationExploration and Mining Geology, Vol. 3, No. 4, Oct. pp. 383-388ZimbabweTomography, chromite, Remote sensing
DS1984-0250
1984
Dyer, H.Dyer, H.De Beers Diamond Synthesis 25th. Anniversary 1959-1984Indiaqua., No. 39, 1984/III, PP. 11-15.South AfricaDiamond Synthesis
DS1970-0284
1971
Dyer, H.B.Dyer, H.B.The Diamond Industry-past, Present and FutureInd. Diamond Rev., FOR 1971, No. 5, PP. 184-188.South Africa, Angola, West Africa, Southwest Africa, NamibiaHistory, Research
DS1986-0296
1986
Dyer, J.B.Goodell, P.C., Keller, G.R., Dyer, J.B.The Sierra Del Nido tectonic block- a newly recognized cratonic feature In northern MexicoGeological Society of America (GSA) (Abstract Volume), Vol. 18, No. 6, p. 618. (abstract.)MexicoTectonics
DS1996-0398
1996
Dyer, M.D.Dyer, M.D., McCammon, C., Schaefer, M.W.Mineral spectroscopy: a tribute to Roger C. BurnsGeochemical Society, Book $ 35.00 United StatesGlobalSpectroscopy, Book -ad
DS200512-0065
2005
Dyer, R.D.Barnet, P.J., Dyer, R.D.Surficial geochemistry case studies project: Lake Nipigon region geoscience initiative.Ontario Geological Survey, Open file 6167, 144p. $ 36.00Canada, OntarioGeochemistry - indicator minerals
DS201605-0837
2016
Dyer, R.D.Gao, C., Crabtree, D.C., Dyer, R.D.Indicator mineral and geochemistry dat a for a till and alluvium sampling survey in the McFaulds Lake ( Ring of Fire) area, northern Ontario. Mentions KIMS.Ontario Geological Survey Report and Data, Report 6309, Data release 322.Canada, OntarioGeochemistry - KIMS
DS1960-1096
1969
Dyer, R.G.Dyer, R.G., Brookins, D.G.Mineralogy and Petrography of the Leonardville Kimberlite, Riley County, Kansas.Geological Society of America (GSA), PT. 2, P. 10, (abstract.).United States, Kansas, Central StatesBlank
DS1970-0070
1970
Dyer, R.G.Dyer, R.G.Petrology of the Leonardville Kimberlite, Riley County, Kansas.Msc. Thesis, Kansas State., United States, Kansas, Central StatesBlank
DS1970-0071
1970
Dyer, R.G.Dyer, R.G., Brookins, D.G.Petrography and Geochemistry of the Leonardville Kimberlite, Riley County, Kansas.Kansas Academy of Science Transactions, Vol. 73, PP. 460-480.United States, Kansas, Central StatesBlank
DS202002-0222
2019
Dygert, N.Zhang, Y., Nelson, P., Dygert, N., Lin, J-F.Fe alloy slurry and a compacting cumulate pile across Earth's inner-core boundary.Journal of Geophysical Research: Solid Earth, doi:10.1029/ 2019JB017792MantleCore boundary

Abstract: Seismic observations show a reduced P wave velocity gradient layer at the bottom ~280 km of the outer core and a hemispherical dichotomy at the top ~50-200 km of the inner core compared to the one?dimensional Preliminary reference Earth model (PREM). These seismic features manifest physical and chemical phenomena linked to thermal evolution and formation processes of the inner core. We have developed a physical model to explain these seismic features. At the inner?outer boundary, the crystallization of Fe alloy co?exists with the residue melt producing a “snowing” slurry layer (F layer), consistent with observed seismic velocity gradient. Solid Fe alloy crystals accumulate and eventually compact at the top of the inner core, and may exhibit lateral variations in thickness between the east?west hemispheres. Our model can explain the east?west asymmetry observed in the seismic velocity. Our model uses mineral physics and seismological results to provide a holistic view of the physical and chemical processes for the inner?core growth over geological time.
DS200612-0359
2004
Dyke, A.Dyke, A.An outline of North American deglaciation with emphasis on central and northern Canada.Ehlers, J., Gibbard, P.L. Quaternary Glaciations - extent and chronology, Elsevier, Vol. 2b Part II, pp. 373-424.Canada, British Columbia, Yukon, AlbertaGeomorphology
DS2002-0411
2002
Dyke, A.L.Dyke, A.L., Harmon, P., Mahanta, A.M.Falcon spreads its wings. Einstein and Newton... now new ones Galileo .. brief summary of performance and rationale behind BHP Billiton business.Preview, August pp. 25-28.Australia, Canada, United States, Mexico, Chile, Peru, South AfricaGeophysics - magnetics, Kimberlites
DS1987-0171
1987
Dyke, A.S.Dyke, A.S.A reinterpretation of glacial and marine limits around the northwestern Laurentide Ice sheet.Canadian Journal of Earth Sciences, Vol. 24, pp. 591-601.Northwest Territories, AlaskaGeomorphology
DS1987-0172
1987
Dyke, A.S.Dyke, A.S., Prest, V.K.The Late Wisconsi nan and Holocene history of the Laurentide ice sheetGeograph. Phys. Quaternaire, Vol. 41, pp. 237-63.Northwest TerritoriesGeomorphology
DS1988-0184
1988
Dyke, A.S.Dyke, A.S., Morris, T.F.Drumlin fields, dispersal trains and ice streams in Arctic CanadaCanadian Geographer, Vol. 32, No. 1, pp. 86-90Ontario, Northwest TerritoriesGeomorphology, Glacial
DS1989-0384
1989
Dyke, A.S.Dyke, A.S., Dredge, L.A.Quaternary geology of the northwestern Canadian ShieldGeological Survey of Canada (GSC) DNAG, Quat Geol., No. 1, pp. 189-214.Northwest TerritoriesGeomorphology
DS1991-0416
1991
Dyke, A.S.Dyke, A.S., Andrews, J. T., et al.Radiocarbon dates pertinent to defining the last glacial maximum for Laurentide andGeological Survey of Canada (GSC) Open File, No. 4120, 50p. $ 13.OntarioGeomorphology
DS1996-0399
1996
Dyke, A.S.Dyke, A.S.Preliminary paleogeographic maps of glaciated North AmericaGeological Survey of Canada, Open file 3296, 6 colour sheets $ 117.00Canada, United StatesAddendum - time slice maps 18, 000 to 1000 BP, Geomorphology maps
DS1996-0400
1996
Dyke, A.S.Dyke, A.S.Preliminary paleogeographic maps of glaciated North AmericaGeological Survey of Canada, Open file, No. 3296, 6 maps $ 120.00Canada, United States, North AmericaMap, Glaciation - paleogeographic
DS2001-0285
2001
Dyke, A.S.Dyke, A.S., Hopper, J.M.G.Deglaciation of northwest Baffin Island, Nunavut. NTS 47 C,D,E,F,G,H, 48A,B,C,D, 57 E.H.,58 A,D.Geological Survey of Canada (GSC) Map, No. 19991, 1:500,000Northwest Territories, Nunavut, Baffin IslandGeomorphology
DS2003-0360
2003
Dyke, A.S.Dyke, A.S., Moore, A., Robertson, L.Deglaciation of North AmericaGeological Survey of Canada Open File, No. 1574, 1 CD, $ 26.00Canada, United StatesGeomorphology
DS2003-0361
2003
Dyke, A.S.Dyke, A.S., St. Onge, D.A., Savelle, J.M.Deglaciation of southwestern Victoria Island and adjacent Arctic mainland, NunavutGeological Survey of Canada Map, No. 2027A, 1: 500,000 $ 20.NunavutGeomorphology
DS200412-0494
2003
Dyke, A.S.Dyke, A.S., Moore, A., Robertson, L.Deglaciation of North America.Geological Survey of Canada Open File, No. 1574, 1 CD, $ 26.00Canada, United StatesGeomorphology
DS200412-0495
2003
Dyke, A.S.Dyke, A.S., St.Onge, D.A., Savelle, J.M.Deglaciation of southwestern Victoria Island and adjacent Arctic mainland, Nunavut, NWT.Geological Survey of Canada Map, No. 2027A, 1: 500,000 $ 20.Canada, NunavutMap Geomorphology
DS2003-0524
2003
Dyke, D.Gurney, J.J., Hildebrand, P., Carlson, J., Dyke, D., Fedortchouk, Y.Diamonds from the Ekati core and buffer zone properties8 Ikc Www.venuewest.com/8ikc/program.htm, Session 3, AbstractNorthwest TerritoriesDiamonds - inclusions, Deposit - Ekati
DS200412-0752
2003
Dyke, D.Gurney, J.J., Hildebrand, P., Carlson, J., Dyke, D., Fedortchouk, Y.Diamonds from the Ekati core and buffer zone properties.8 IKC Program, Session 3, AbstractCanada, Northwest TerritoriesDiamonds - inclusions Deposit - Ekati
DS200812-0306
2008
Dyksterhuis, S.Dyksterhuis, S., Muller, R.D.Cause and evolution of interplate orogeny in Australia.Geology, Vol. 36, 6, June pp. 495-498.AustraliaTectonics
DS1988-0185
1988
Dymek, R.F.Dymek, R.F., Boak, J.L., Brothers, S.C.Titanium chondrite- and titaium clinohumite-bearing metadunite from the3800 Ma Usua supracrustal belt, west Greenland:chemistry, petrology andoriginAmerican Mineralogist, Vol. 73, No. 5-6, May-June pp. 547-558GreenlandBlank
DS2001-0875
2001
Dymek, R.F.Owens, B.E., Dymek, R.F.Petrogenesis of the Labrieville alkalic anorthosite Massif, Grenville Province, QuebecJour. Petrol., Vol. 42, No.8, pp. 1519-46.Quebec, GrenvilleAlkaline rocks
DS1995-0468
1995
Dyment, J.Dyment, J., Arkanihan, J.Spreading rate dependent magnetization of the oceanic lithosphere -magnetic anomalies -review... marine.Geophys. Journal of International, Vol. 121, No. 3, June pp. 789-804.OceansGeophysics -magnetics, Lithosphere
DS1996-0042
1996
Dyment, J.Arkani-Hamed, J., Dyment, J.Magnetic potential and magnetization contrasts of Earth's lithosphereJournal of Geophysical Research, Vol. 101, No. 5, May 10, pp. 1401-26.MantleGeophysics -magnetics
DS201012-0085
2010
Dyment, J.Cande, S.C., Patroat, P., Dyment, J.Motion between the Indian, Antarctic and African plates in the early Cenozoic.Geophysical Journal International, in press availableMantleGeotectonics
DS1987-0173
1987
Dymer, R.F.Dymer, R.F.Petrogenetic implications of pyroxene compositional trends In the St.Urbain anorthosite complex and associated rocks, QuebecGeological Society of America, Vol. 19, No. 7 annual meeting abstracts, p.650. abstracQuebecAnorthosite
DS1987-0174
1987
Dymkin, A.M.Dymkin, A.M., Bobylev, I.B., Anfilogov, V.N.Study of low temperature immiscibility of melts in the systemleucite-fayalite-anorthite-silicaDoklady Academy of Science USSR, Earth Science Section, Vol. 284, No. 5, Publishing July 1987, pp. 120-122RussiaLeucite
DS1993-0936
1993
Dymnikov, W.G.Lukyanova, L.I., Derevyan, I.V., Mareiche, A.M., Dymnikov, W.G.On manifestation of Mesozoic ultra potassium magmatism and prospects of diamond bearing of Chernyshev Range district, Polar Urals.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 330, No. 5, June pp. 617-619.Russia, Commonwealth of Independent States (CIS), UralsAlkaline rocks, Ultrapotassic
DS1975-0271
1976
Dymnikova, N.G.Dymnikova, N.G., Gnevushev, M.A., et al.Temperature Influence on Behaviour of Chromium Ions During Synthesis of Pyrope.Zap. Vses. Mineral. Obshch., No. 4, PP. 472-475.RussiaMineral Chemistry
DS201012-0060
2010
Dymshits, A.Bobrov, A., Dymshits, A., Litvin, Yu., Litasov, K., Shatskiy, A., Ohtani, E.Sodium bearing majorite garnet: nature and experimental aspects.International Mineralogical Association meeting August Budapest, abstract p. 148.Russia, Timan, South America, Brazil, ChinaUHP
DS201412-0216
2014
Dymshits, A.Dymshits, A., Litasov, K., Sharygin, I., Shatskiy, A., Ohtani, E.Mineral physics of high pressure garnets.V.S. Sobolev Institute of Geology and Mineralogy Siberian Branch Russian Academy of Sciences International Symposium Advances in high pressure research: breaking scales and horizons ( Courtesy of N. Poikilenko), Held Sept. 22-26, 2p. AbstractTechnologyGarnet
DS201504-0194
2015
Dymshits, A.Dymshits, A., Sharygin, I., Litasov, K., Shatskiy, A., Gavryushkin, P., Ohtani, E., Suzuki, A., Funakoshi, K.In situ observation of the pyroxene majorite transition in Na2MgSi5O12 using synchroton radiation and Raman spectroscopy of Na-majorite.American Mineralogist, Vol. 100, pp. 378-384.MantleMajorite
DS201910-2256
2019
Dymshits, A.Dymshits, A., Sharygin, I., Yakolev, I., Malovets, V.Thermal state and composition of the lithospheric mantle beneath the Upper Muna kimberlite field, Yakutia.Goldschmidt2019, 1p. AbstractRussia, Yakutiadeposit - Upper Muna

Abstract: Mantle xenoliths brought up by kimberlitic magmas are the main source of data on the composition and physical conditions of cratonic mantle. Temperature varioations in a complete lithospheric mantle section (80-200 km) of the Siberian craton beneath the Upper Muna kimberlite filed are estimated based 49 peridotite xenolith and 330 Cpx grains from the Komsomolskaya-Magnitnaya pipe. Pressure and temperature estimates closely follow the 34.5 mW/m2 conductive geotherm. Thermal lithospere thickness is of ~ 220 km, and “diamond window” in the Paleozoic is ~75 km thick (Fig.1). Olivine compositions range in Mg# from 82 to 94 and the majority of olivenes has very high Mg# > 93. Garnets compositions mainlly follow to harzburgite-dunite and lherzolite trends plotted as Cr2O3 vs CaO. The composition of the minerals indicated the extremly depleted lithospheric mantle beneath the Upper-Muna kimberlite field. Figure 1: Model palaeogeotherms calculated using the program FITPLOT. Komsomolskaya-Magnitnaya - our data, Novinka and Udachaya are from Z16 [1]
DS202010-1840
2020
Dymshits, A.Dymshits, A., Sharygin, I., Malkovets, V., Yakovlev, I.V., Gibsher, A.A., Alifirova, T.A., Vorobei, S.S., Potapov, S.V., Garanin, V.K.Thermal state, thickness and composition of the lithospheric mantle beneath the Upper Muna kimberlite field, Siberian Craton, constrained by clinopyroxene xenocrysts and comparison with Daldyn and Mirny fields.Minerals, 10.1039/DOJA00308E 20p. PdfRussiadeposit - Muna

Abstract: To gain better insight into the thermal state and composition of the lithospheric mantle beneath the Upper Muna kimberlite field (Siberian craton), a suite of 323 clinopyroxene xenocrysts and 10 mantle xenoliths from the Komsomolskaya-Magnitnaya (KM) pipe have been studied. We selected 188 clinopyroxene grains suitable for precise pressure (P)-temperature (T) estimation using single-clinopyroxene thermobarometry. The majority of P-T points lie along a narrow, elongated field in P-T space with a cluster of high-T and high-P points above 1300 °C, which deviates from the main P-T trend. The latter points may record a thermal event associated with kimberlite magmatism (a “stepped” or “kinked” geotherm). In order to eliminate these factors, the steady-state mantle paleogeotherm for the KM pipe at the time of initiation of kimberlite magmatism (Late Devonian-Early Carboniferous) was constrained by numerical fitting of P-T points below T = 1200 °C. The obtained mantle paleogeotherm is similar to the one from the nearby Novinka pipe, corresponding to a ~34-35 mW/m2 surface heat flux, 225-230 km lithospheric thickness, and 110-120 thick "diamond window" for the Upper Muna field. Coarse peridotite xenoliths are consistent in their P-T estimates with the steady-state mantle paleogeotherm derived from clinopyroxene xenocrysts, whereas porphyroclastic ones plot within the cluster of high-T and high-P clinopyroxene xenocrysts. Discrimination using Cr2O3 demonstrates that peridotitic clinopyroxene xenocrysts are prevalent (89%) among all studied 323 xenocrysts, suggesting that the Upper Muna mantle is predominantly composed of peridotites. Clinopyroxene-poor or -free peridotitic rocks such as harzburgites and dunites may be evident at depths of 140-180 km in the Upper Muna mantle. Judging solely from the thermal considerations and the thickness of the lithosphere, the KM and Novinka pipes should have excellent diamond potential. However, all pipes in the Upper Muna field have low diamond grades (<0.9, in carats/ton), although the lithosphere thickness is almost similar to the values obtained for the high-grade Udachnaya and Mir pipes from the Daldyn and Mirny fields, respectively. Therefore, other factors have affected the diamond grade of the Upper Muna kimberlite field.
DS202010-1841
2020
Dymshits, A.Dymshits, A., Sharygin, I., Liu, Z., Korolev, N., Malkovets, V., Alifirova, T., Yakovlev, I., Xu, Y-G.Oxidation state of the lithospheric mantle beneath Komosomolskaya-Magnitnaya kimberlite pipe, Upper Muna field, Siberian craton.Minerals, Vol. 10, 9, 740 10.3390/ min10090740 24p. PdfRussiadeposit - Muna

Abstract: The oxidation state of the mantle plays an important role in many chemical and physical processes, including magma genesis, the speciation of volatiles, metasomatism and the evolution of the Earth’s atmosphere. We report the first data on the redox state of the subcontinental lithospheric mantle (SCLM) beneath the Komsomolskaya-Magnitnaya kimberlite pipe (KM), Upper Muna field, central Siberian craton. The oxygen fugacity of the KM peridotites ranges from ?2.6 to 0.3 logarithmic units relative to the fayalite-magnetite-quartz buffer (?logfO2 (FMQ)) at depths of 120-220 km. The enriched KM peridotites are more oxidized (?1.0-0.3 ?logfO2 (FMQ)) than the depleted ones (from ?1.4 to ?2.6 ?logfO2 (FMQ)). The oxygen fugacity of some enriched samples may reflect equilibrium with carbonate or carbonate-bearing melts at depths >170 km. A comparison of well-studied coeval Udachnaya and KM peridotites revealed similar redox conditions in the SCLM of the Siberian craton beneath these pipes. Nevertheless, Udachnaya peridotites show wider variations in oxygen fugacity (?4.95-0.23 ?logfO2 (FMQ)). This indicates the presence of more reduced mantle domains in the Udachnaya SCLM. In turn, the established difference in the redox conditions is a good explanation for the lower amounts of resorbed diamonds in the Udachnaya pipe (12%) in comparison with the KM kimberlites (33%). The obtained results advocate a lateral heterogeneity in the oxidation state of the Siberian SCLM.
DS200912-0058
2009
Dymshits, A.M.Bobrov, A.V., Spivak, A.V., Divaev, F.K., Dymshits, A.M., Litvin, Yu.A.High pressure melting relations of diamond forming carbonatites: formation of syngenetic peridotitic and eclogitic minerals ( experiments at 7.0 and 8.5 GPa).alkaline09.narod.ru ENGLISH, May 10, 2p. abstractTechnologyMelting
DS200912-0195
2009
Dymshits, A.M.Dymshits, A.M., Bobrov, A.V., Litvin, Yu.A.Experimental study of formation of Na rich majorite garnet in the context of diamond deep mantle genesis.alkaline09.narod.ru ENGLISH, May 10, 2p. abstractTechnologyDiamond stability
DS201012-0061
2009
Dymshits, A.M.Bobrov, A.V., Dymshits, A.M., Litvin, Yu.Conditions of magmatic crystallization of Na bearing majoritic garnets in the Earth mantle: evidence from experimental and natural data.Geochemistry International, Vol. 47, 10, Oct. pp. 951-965.MantleMagmatism
DS201112-0096
2011
Dymshits, A.M.Bobrov, A.V., Litvin, Yu.A., Dymshits, A.M.Experimental studies of carbonatite silicate systems and problem of the diamond formation.Moscow, GEOS, IN RUSSIAN, 208p. IN RUSSIANTechnologyBook - reference only
DS201212-0178
2012
Dymshits, A.M.Dymshits, A.M., Bindi, L., Bobrov, A.V., Litasov, K.D., Shatskiy, A.F., Ohtani, E., Litvin, Yu.A.Sodium majorite and its pyrope solid solutions high pressure experiment and crystal chemical implications.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractTechnologyMineral Chemistry
DS201502-0055
2015
Dymshits, A.M.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
Dymshits, A.M.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.
DS202112-1945
2021
Dymshits, A.M.Sharygin, I.S., Golovin, A.V., Dymshits, A.M., Kalugina, A.D., Solovev, K.A., Malkovets, V.G., Pokhilenko, N.P.Relics of deep alkali-carbonate melt in the mantle xenolith from the Komosomolskaya-Magnitnaya kimberlite pipe ( Upper Muna field, Yakutia).Doklady Earth Sciences, Vol. 500, 2, pp. 842-847.Russia, Yakutiadeposit - Komosomolskaya-Magnitnaya

Abstract: The results of study secondary crystallized melt inclusions in olivine of a sheared peridotite xenolith from the Komsomolskaya-Magnitnaya kimberlite pipe (Upper Muna field, Yakutia) are reported. Monticellite, phlogopite, tetraferriphlogopite KMg3(Fe3+)Si3O10(F,Cl,OH), apatite, aphthitalite K3Na(SO4)2, burkeite Na6CO3(SO4)2, and carbonates, namely calcite, nyerereite (Na,K)2Ca(CO3)2, shortite Na2Ca2(CO3)3, and eitelite Na2Mg(CO3)2, were detected among the daughter minerals of the melt inclusions by the method of confocal Raman spectroscopy. The abundance of alkali carbonates in the inclusions indicates the alkali-carbonate composition of the melt. Previously, identical inclusions of alkali-carbonate melt were reported in olivine of sheared peridotites from the Udachnaya pipe (Daldyn field). Melt inclusions in sheared peridotites are the relics of a crystallized kimberlite melt that penetrated into peridotites either during the transport of xenoliths to the surface or directly in the mantle shortly prior to the entrapment of xenoliths by the kimberlite magma. If the second scenario took place, the finds of alkali-carbonate melt inclusions in sheared peridotites carried from different mantle depths in the Udachnaya and Komsomolskaya-Magnitnaya kimberlite pipes indicate a large-scale metasomatic alteration of the lithospheric mantle of the Siberian Craton by alkaline-carbonate melts, which preceded the kimberlite magmatism. However, regardless of which of the two models proposed above is correct, the results reported here support the alkali-carbonate composition of primary kimberlite melts.
DS202202-0201
2022
Dymshits, A.M.Kostrivitsky, S.I., Yakolev, D.A., Sharygin, I.S., Gladkochub, D.P., Donskaya, T.V., Tretiakova, I.G., Dymshits, A.M.Diamondiferous lamproites of Ingashi field, Siberian craton.Geological Society of London Special Publication 513, pp. 45-70.Russialamproites

Abstract: Ingashi lamproite dykes are the only known primary sources of diamond in the Irkutsk district (Russia) and the only non-kimberlitic one in the Siberian craton. The Ingashi lamproite field is situated in the Urik-Iya graben within the Prisayan uplift of the Siberian craton. The phlogopite-olivine lamproites contain olivine, talc, phlogopite, serpentine, chlorite, olivine, garnet, chromite, orthopyroxene, clinopyroxene as well as Sr-F-apatite, monazite, zircon, armolcolite, priderite, potassium Mg-arfvedsonite, Mn-ilmenite, Nb-rutile and diamond. The only ultramafic lamprophyre dyke is composed mainly of serpentinized olivine and phlogopite in the talc-carbonate groundmass and is similar to Ingashi lamproites accessory assemblage with the same major element compositions. Trace element and Sr-Nd isotopic relationships of the Ingashi lamproites are similar to classic lamproites. Different dating methods have provided the ages of lamproites: 1481 Ma (Ar-Ar phlogopite), 1268 Ma (Rb-Sr whole rock) and 300 Ma (U-Pb zircon). Ingashi lamproite ages are controversial and require additional study. The calculated pressure of 3.5 GPamax for clinopyroxenes indicates that lamproite magma originated deeper than 100 km. A Cr-in-garnet barometer shows a 3.7-4.3 GPamin and derivation of Ingashi lamproites deeper than 120 km in depth. Based on the range of typical cratonic geotherms and the presence of diamonds, the Ingashi lamproite magma originated at a depth greater than 155 km.
DS1990-1170
1990
Dyrelius, D.Pederson, L.B., Rasmussen, T.M., Dyrelius, D.Construction of component maps from aeromagnetic total field anomaly mapsGeophysical Prospecting, Vol. 38, pp. 795-804GlobalGeophysics, Aeromagnetics- component maps
DS1997-0301
1997
Dysinger, D.K.Dysinger, D.K.Capital budgeting: forecasting the future #1Mining Engineering, Vol. 49, No. 9, September pp. 35-38GlobalEconomics, Cash flow, forecasting, budget
DS1997-0302
1997
Dysinger, D.K.Dysinger, D.K.Capital budgeting: forecasting the future #2Society for Mining, Metallurgy and Exploration (SME) Preprint, No. 97-118, 7pGlobalEconomics, discoveries, Budgets - capital
DS1983-0207
1983
Dziedzic, A.Dziedzic, A., Ryka, W.Carbonatites in the Tajno Intrusion, (northeast Poland).*polArchiwum Mineral., *POL, Vol. 38, No. 2, pp. 4-34GlobalCarbonatite
DS201212-0400
2012
Dziewonski, A.Lekic, V., Cottaar, S., Dziewonski, A., Romanowicz, B.Cluster analysis of global lower mantle tomography: a new class of structure and implications for chemical heterogeneity.Earth and Planetary Science Letters, Vol. 357-358, pp. 68-77.MantleBoundary
DS1984-0015
1984
Dziewonski, A.M.Anderson, D.L., Dziewonski, A.M.Seismic TomographySci. American, Vol. 251, No. 4, Oct. pp. 60-80.MantleTomography, Geophysics - Seismics
DS1991-0503
1991
Dziewonski, A.M.Forte, A.M., Peltier, W.R., Dziewonski, A.M.Inferences of mantle viscosity from tectonic plate velocitiesGeophysical Research Letters, Vol. 18, No. 9, September pp. 1747-1750GlobalMantle, Geophysics -plate tectonics
DS1991-1671
1991
Dziewonski, A.M.Su Weijun, Dziewonski, A.M.Predominance of long wave length heterogeneity in the mantleNature, Vol. 352, No. 6331, July 11, pp. 121-125GlobalMantle, Geophysics-seismics
DS1995-0552
1995
Dziewonski, A.M.Forte, A.M., Dziewonski, A.M., O'Connell, R.J.Continent ocean chemical heterogeneity in the mantle based on seismictomography.Science, Vol. 268, April 21, pp. 386-388.MantleGeodynamic, Geophysics -seismics
DS1998-0888
1998
Dziewonski, A.M.Liu, X.F., Tromp, J., Dziewonski, A.M.Is there a first order discontinuity in the lowermost mantle?Earth and Planetary Science Letters, Vol. 160, No. 3-4, Aug. 1, pp. 343-52.MantleGeophysics - seismics, Discontinuity
DS2001-0420
2001
Dziewonski, A.M.Gu, Y., Dziewonski, A.M., Ekstrom, C.Preferential detection of the Lehmann discontinuity beneath continentsGeophysical Research Letters., Vol. 28, No. 24, Dec. 15, pp. 4655-58.MantleGeophysics - seismics, Discontinuity, boundary
DS2003-0516
2003
Dziewonski, A.M.Gu, Y.J., Dziewonski, A.M., Ekstrom, G.Simultaneous inversion for mantle shear velocity and topography of transition zoneGeophysical Journal International, Vol. 154, 2, pp. 559-83.MantleGeophysics - seismics, Discontinuity
DS200412-0738
2004
Dziewonski, A.M.Gu, Yu.J., Dziewonski, A.M., Ekstrom, G.Simultaneous inversion for mantle shear velocity and topography of transition zone discontinuities.Geophysical Journal International, Vol. 154, 2, pp. 559-583.MantleGeophysics - seismics, boundary
DS200412-1130
2003
Dziewonski, A.M.Li, X., Kind, R., Yuan, X., Sobolev, S.V., Hanka, W., Ramesh, D.S., Gu, Y., Dziewonski, A.M.Seismic observation of narrow plumes in the oceanic upper mantle.Geophysical Research Letters, Vol. 30, 6, p. 67. DOI10.1029/2002 GLO15411MantleGeophysics - seismics Plumes
DS200512-0256
2005
Dziewonski, A.M.Dziewonski, A.M.The robust aspects of global seismic tomography.Plates, Plumes, and Paradigms, pp. 147-154. ( total book 861p. $ 144.00)GlobalGeophysics - seismics, tomography - overview
DS200812-0256
2008
Dziewonski, A.M.Dalton, C.A., Ekstrom, G., Dziewonski, A.M.The global attenuation structure of the upper mantle.Journal of Geophysical Research, Vol. 113, B09303.MantleGeodynamics
DS200812-0257
2008
Dziewonski, A.M.Dalton, C.A., Ekstrom, G., Dziewonski, A.M.The global attenuation structure of the upper mantle.Journal of Geophysical Research, Vol. 113, B9, B09303.MantleTectonics
DS200812-0619
2008
Dziewonski, A.M.Kustowski, B., Ekstrom, G., Dziewonski, A.M.Anisotropic shear wave velocity structure of the Earth's mantle: a global model.Journal of Geophysical Research, Vol. 113, B6306.MantleModel
DS200812-0620
2008
Dziewonski, A.M.Kustowski, B., Ekstrom, G., Dziewonski, A.M.Anisotropic shear wave velocity structure of the Earth's mantle: a global model.Journal of Geophysical Research, Vol. 113, B06306MantleTomography
DS200812-0792
2008
Dziewonski, A.M.Nettles, M., Dziewonski, A.M.Radially isotopic shear velocity structure of the upper mantle globally and beneath North America.Journal of Geophysical Research, Vol. 113, B02303.MantleGeophysics - seismics
DS201012-0176
2010
Dziewonski, A.M.Dziewonski, A.M., Lekic, V., Romanowicz, B.A.Mantle anchor structure: an argument for bottom up tectonics.Earth and Planetary Science Letters, Vol. 299, pp. 69-79.MantleSubduction
DS1998-1483
1998
Dziewowski, A.M.Tromp, J., Dziewowski, A.M.Two views of the deep mantleScience, Vol. 281, No. 5377, July 31, p. 656.MantleGenesis
DS200612-0360
2006
Dziggel, A.Dziggel, A., Knipfer, S., Kisters, A.F.M., Meyer, F.M.PT and structural evolution during exhumation of high T, medium P basement rocks in the Barberton Mountain Land, South Africa.Journal of Metamorphic Geology, Vol. 24, 7, Sept. pp. 535-551.Africa, South AfricaTectonics
DS201312-0234
2013
Dziuba, F.Dziuba, F.A geophysical case history for kimberlite exploration, Kennady North, NT.2013 Yellowknife Geoscience Forum Abstracts, p. 17-18. abstractCanada, Northwest TerritoriesGeophysics - Kelvin
DS1988-0506
1988
Dzurisin, D.Newhall, C.G., Dzurisin, D.Historical unrest at large calderas of the worldUnited States Geological Survey (USGS) Bulletin, No. 1855, two volumes 598p., 510p. $ 34.00 United States approxGlobalBook -review, Calderas
DS1997-1129
1997
Dzurisin, D.Svorak, J.J., Dzurisin, D.Volcano geodesy: the search for magma reservoirs and the formation of eruptive ventsReviews of Geophysics, Vol. 35, No. 3, August pp. 343-384Hawaii, California, Italy, Papua New Guinea, JapanMagma, Vents
DS200512-0344
2005
DzyubaGladkov, A.S., Zinchuk, N.N, Bornyakov, S.A., Sherman, S.I., Manakov, A.V., Matrosov, V.A., Garat, DzyubaNew dat a on the internal structure and formation mechanism of kimberlite hosting fault zones in the Malaya Botuoba region, Yakutian Diamondiferous provinceDoklady Earth Sciences, Vol. 402, 4, pp. 520-23.Russia, YakutiaTectonics, structure, Malaya Botuoba
DS1983-0652
1983
Dzyublo, A.D.Zinchuk, N.N., Kharkiv, A.D., Kotelnikov, D.D., Dzyublo, A.D.Serpentine from Kimberlites of YakutiaAkad. Nauk Sssr Mineral. Muzey Im A.e. Fersmana., No. 31, PP. 65-81.Russia, YakutiaMineralogy
Author Index
A-An Ao+ B-Bd Be-Bk Bl-Bq Br+ C-Cg Ch-Ck Cl+ D-Dd De-Dn Do+ E F-Fn Fo+ G-Gh Gi-Gq Gr+ H-Hd He-Hn Ho+ I J K-Kg Kh-Kn Ko-Kq Kr+ L-Lh
Li+ M-Maq Mar-Mc Md-Mn Mo+ N O P-Pd Pe-Pn Po+ Q R-Rh Ri-Rn Ro+ S-Sd Se-Sh Si-Sm Sn-Ss St+ T-Th Ti+ U V W-Wg Wh+ X Y Z
 
 

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