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SDLRC - Scientific Articles all years by Author - Y


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 - Y
Posted/
Published
AuthorTitleSourceRegionKeywords
DS201812-2844
2018
Y, m Zhengm J-P.Ma, Q., Xu, Y-G., Deng, Y,m Zhengm J-P., Sur, M., Griffin, W.L., Xia, B., Yan Wang, C.Similar crust beneath disrupted and intact cratons: arguments against lower crust delamination as a decratonization trigger. North China cratonTectonophysics, in press available 31p.Chinacraton

Abstract: The continental lithosphere is not forever; some cratons have lost their original roots during the course of their evolution. Yet, it is not clear whether gravitational instability of dense lower crust is the primary driver of decratonization. This is addressed here with emphasis being placed on the North China Craton (NCC), because it represents one of the best examples of craton-root disruption in the world, and a place where models can be tested. If lower-crustal delamination was the trigger for decratonization, we would expect a clear contrast in crustal structure and composition between disturbed (rootless) and intact cratons. However, the eastern (disturbed) and western (intact) parts of the NCC show virtually identical physical structure and composition (a thin mafic lower crust and a predominantly intermediate composition overall) although the crust in the disturbed part is thinner than in the intact craton. This suggests that delamination of the lower crust was not a viable mechanism of craton-root disruption in the NCC case. Indeed, the crust beneath the NCC largely resembles those of stable Archean cratons worldwide. Therefore the delamination, if it occurred, may have taken place much earlier (Archean) than previously thought, rather than in the Mesozoic. Delamination may have been a common phenomenon in the early evolution of cratons, probably due to relatively higher mantle temperatures in the Archean Eon.
DS1995-2093
1995
Yaalon, D.H.Yaalon, D.H.The soils we classify. Essay review of recent publications on soiltaxonomyCatena, Vol. 24, No. 4, Oct. 1, pp. 233-242GlobalSoils, geomorphology, Classification
DS2002-1445
2002
Yabovskaya, T.B.Sgrigna, V., D'Ambrosio, C., Yabovskaya, T.B.Numerical modeling of preseismic slow movements crustal blocks caused by quasi-horizontal tectonic forcesPhysics of the Earth and Planetary Interiors, Vol.129, 3-4, pp.313-24.MantleTectonics
DS200912-0828
2009
Yabubchuk, A.Yabubchuk, A.Diamond deposits of the Siberian Craton: products of post 1200 Ma plume events affecting the lithospheric keel.Ore Geology Reviews, Vol. 15, pp. 155-163.Russia, SiberiaDiamond deposits
DS2002-1462
2002
Yabuta, H.Shimoyama, A., Yabuta, H.Mono and bicyclic alkanes and diamondoid hydrocarbons in the Cretaceous Tertiary boundary sediments HokkaidoGeochemical Journal, Vol.36,pp.173-89., Vol.36,pp.173-89.JapanGeochemistry - not on topic but interesting, Diamondoid hydrocarbons
DS2002-1463
2002
Yabuta, H.Shimoyama, A., Yabuta, H.Mono and bicyclic alkanes and diamondoid hydrocarbons in the Cretaceous Tertiary boundary sediments HokkaidoGeochemical Journal, Vol.36,pp.173-89., Vol.36,pp.173-89.JapanGeochemistry - not on topic but interesting, Diamondoid hydrocarbons
DS1992-1710
1992
Yacoot, A.Yacoot, A., Moore, M.An unusual octahedral diamondMineralogical Magazine, Vol. 56, No. 382, March pp. 111-113GlobalDiamond morphology, Mineralogy
DS1993-1785
1993
Yacoot, A.Yacoot, A., Moore, M.X-ray topography of natural tetrahedral diamondsMineralogical Magazine, Vol. 57, No. 387, June pp. 223-230.South AfricaDiamond morphology, Williams' collection diamonds, X-ray
DS200812-0427
2007
Yadrenkin, A.V.Grakhanov, S.A., Yadrenkin, A.V.Prediction of the diamond potential of Triassic rocks in Taimyr.Doklady Earth Sciences, Vol. 417, 8, pp. 1147-1150.RussiaDiamond genesis
DS1997-0926
1997
Yagel, R.Pride, D.E., Memmi, J.M., Loomis, J., Yagel, R.SEARCHMAP - interactive map interpretation system for mineral explorationExplore., No. 95, April pp. 1, 3-10MidcontinentComputer - GIS, Remote sensing, GIS datasets
DS1997-0927
1997
Yagel, R.Pride, D.E., Memmi, J.M., Loomis, J., Yagel, R.SEARCHMAP - interactive map exploration system for mineral exploration.Specific application for diamonds.Explore, No. 95, April pp. 1, 3-10.MidcontinentGIS, Map information data
DS2001-0783
2001
YagiMiyajima, N., Yagi, Hirose, Kondo, Fujino, MiuraPotential host phase of aluminum and potassium in the Earth's lower mantleAmerican Mineralogist, Vol. 86, pp. 740-46.MantleAlkali earth elements
DS200512-1063
2005
YagiSueda, Y., Irifune, T., Nishiyama, N., Rapp, Ferroir, Onozawa, Yagi, Merkel, Miyajima, FunakoshiA new high pressure form of K Al Si3 08 under lower mantle conditions.Geophysical Research Letters, Vol. 31, 23, Dec. 16, DOI 10.1029/2004 GLO21156MantleUHP
DS1960-0769
1966
Yagi, K.Yagi, K., Matsumoto, H.Note on the Leucite Bearing Rocks from the Leucite Hills, Wyoming.Journal of FACULTY SCI. HOKKAIDO University SER. 4, GEOL. MIN., Vol. 13, No. 3, PP. 301-315.GlobalLeucite Hills, Leucite, Rocky Mountains
DS1975-0191
1975
Yagi, K.Sobolev, V.S., Bazarova, T.YU., Yagi, K.Crystallization Temperatures of Wyomingite from Leucite HillContributions to Mineralogy and Petrology, Vol. 49, PP. 301-308.GlobalLeucite Hills, Leucite, Rocky Mountains
DS1980-0150
1980
Yagi, K.Gupta, A.K., Yagi, K.Leucite Bearing Rocks of Manchuria, ChinaSpringer-verlag Publishing, 252P. PP. 86-89. CHINA.ChinaBlank
DS1980-0151
1980
Yagi, K.Gupta, A.K., Yagi, K.Petrology and Genesis of Leucite Bearing Rocks #2New York: Springer Verlag, Vol. 14, 252P.GlobalKimberley, Janlib
DS1980-0152
1980
Yagi, K.Gupta, A.K., Yagi, K., Thermier, H.Petrology and Genesis of Leucite Bearing Rocks #1Chemical Geology, Vol. 31, No. 1-2, PP. 161-163.GlobalLeucite, Genesis, History
DS1986-0319
1986
Yagi, K.Gupta, A.K., Yagi, K., Lovering, J., Jaques, A.L.Geochemical and microprobe studies of diamond bearing ultramafic rocks from central and south IndiaProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 27-29IndiaGeochemistry, Mineral chemistry
DS1990-1603
1990
Yagi, K.Yagi, K., Gupta, A.K., Chatterjee, V.P.The alkalic rocks from Amba Dunga, Deccan Plateau, IndiaInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 2, extended abstract p. 828-829IndiaCarbonatite, Ijolite
DS1998-0779
1998
Yagi, T.Kondo, T., Yagi, T.Phase transition of pyrope garnet under lower mantle conditionsAmerican Geophysical Union (AGU) Geo. Mon., No. 101, pp.MantleGarnet - pyrope
DS1998-0932
1998
Yagi, T.Manghnani, M.H., Yagi, T.Properties of earth and planetary materials at high pressure andtemperature.American Geophysical Union (AGU) Geophys. Monograph., No. 101, 558p. $ 90.00MantleSeperate articles cited of interest
DS2002-1754
2002
Yagi, T.Yagi, T.Behaviour of Earth Materials under deep mantle conditionsProceedings - International School of Physics Enrico Fermi, Vol. 147, pp. 643-56.. Ingenta 1025439481MantleReactions
DS200412-0590
2004
Yagi, T.Fujino, K., sasaki, Y., Komori, T., Ogawa, H., Miyajima, N., Sata, N., Yagi, T.Approach to the mineralogy of the lower mantle by a combined method of a laser heated diamond anvil cell experiment and analyticPhysics of the Earth and Planetary Interiors, Vol. 143-144, pp. 215-221.MantleMineralogy - experimental
DS201412-0403
2014
Yagi, T.Imada, S., Ohta, K., Yagi, T., Hirose, K., Yoshida, H., Nagahara, H.Measurements of lattice thermal conductivity of MgO to core-mantle boundary.Geophysical Research Letters, Vol. 41, 13, pp. 4542-4547.MantleGeothermometry
DS201704-0643
2017
Yagi, T.Ohta, K., Yagi, T., Hirose, K., Ohishi, Y.Thermal conductivity of ferropericlase in the Earths's lower mantle.Earth and Planetary Science Letters, Vol. 465, pp. 29-37.MantleGeothermometry

Abstract: (Mg,?Fe)O ferropericlase (Fp) is one of the important minerals comprising Earth's lower mantle, and its thermal conductivity could be strongly influenced by the iron content and its spin state. We examined the lattice thermal conductivity of (Mg,?Fe)O Fp containing 19 mol% iron up to 111 GPa and 300 K by means of the pulsed light heating thermoreflectance technique in a diamond anvil cell. We confirmed a strong reduction in the lattice thermal conductivity of Fp due to iron substitution as reported in previous studies. Our results also show that iron spin crossover in Fp reduces its lattice thermal conductivity as well as its radiative conduction. We also measured the electrical conductivity of an identical Fp sample up to 140 GPa and 2730 K, and found that Fp remained an insulator throughout the experimental conditions, indicating the electronic thermal conduction in Fp is negligible. Because of the effects of strong iron impurity scattering and spin crossover, the total thermal conductivity of Fp at the core-mantle boundary conditions is much smaller than that of bridgmanite (Bdg). Our findings indicate that Bdg (and post-perovskite) is the best heat conductor in the Earth's lower mantle, and distribution of iron and its valence state among the lower mantle minerals are key factors to control the lower mantle thermal conductivity.
DS202009-1649
2020
Yagi, T.Okuda, Y., Ohta, K., Haseawa, A., Yagi, T., Hirose, K., Kawaguchi, S.I., Ohishi, Y.Thermal conductivity of Fe bearing post- perovskite in the Earth's lowermost mantle.Earth and Planetary Science Letters, Vol. 547, 9p. PdfMantleperovskite

Abstract: The thermal conductivity of post-perovskite (ppv), the highest-pressure polymorph of MgSiO3 in the Earth's mantle, is one of the most important transport properties for providing better constraints on the temperature profile and dynamics at the core-mantle boundary (CMB). Incorporation of Fe into ppv can affect its conductivity, which has never been experimentally investigated. Here we determined the lattice thermal conductivities of ppv containing 3 mol% and 10 mol% of Fe at high P-T conditions - of pressures up to 149 GPa and 177 GPa, respectively, and temperatures up to 1560 K - by means of the recently developed pulsed light heating thermoreflectance technique combining continuous wave heating lasers. We found that the incorporation of Fe into ppv moderately reduces its lattice thermal conductivity as it increases the Fe content. The bulk conductivity of ppv dominant pyrolite is estimated as 1.5 times higher than that of pyrolite consisting of bridgmanite and ferropericlase in the lower mantle, which agrees with the traditional view that ppv acts as a better heat conductor than bridgmanite in the Earth's lowermost mantle.
DS1997-1277
1997
Yagmurlu, F.Yagmurlu, F., Savascin, Y., Ergun, M.Relation of alkaline volcanism and active tectonism within the evolution Of the I sparta Angle, southwest TurkeyJournal of Geology, Vol. 105, No. 6, Nov. pp. 717-728Turkeyvolcanism., Tectonics
DS1989-1666
1989
Yagneyshev, B.S.Yagneyshev, B.S., Yagnysheva, T.A., Khmelevskiy, V.A.Practical significance of lithogeochemical characteristics of secondary dispersion aureoles near kimberlites.(Russian)Mineralogischeskiy Sbornik, (L'vov), (Russian), Vol. 43, No. 2, pp. 77-82.Russia, YakutiaGeochemistry, Siberian Platform
DS1984-0781
1984
Yagnyshev, B.S.Yagnyshev, B.S., Yagnysheva, T.A., Khmelevskiy, V.A., Zatkhey, R.A.Mineral composition pecularities of the lower Paleozoic rocks around kimberlite bodies, west Yakutia.(Russian)Mineral. Zhurn., (Russian), Vol. 38, No. 1, pp. 49-55RussiaBlank
DS1987-0819
1987
Yagnyshev, B.S.Yagnyshev, B.S., Khmelevekiy, V.A.The concealed halo dispersion patterns of Yakutia kimberlites.(Russian)Mineral. Sbornik (L'Vov), (Russian), Vol. 41, No. 1, pp. 87-91RussiaGeochemistry, Deposit -Yakutia area
DS1984-0781
1984
Yagnysheva, T.A.Yagnyshev, B.S., Yagnysheva, T.A., Khmelevskiy, V.A., Zatkhey, R.A.Mineral composition pecularities of the lower Paleozoic rocks around kimberlite bodies, west Yakutia.(Russian)Mineral. Zhurn., (Russian), Vol. 38, No. 1, pp. 49-55RussiaBlank
DS1989-1666
1989
Yagnysheva, T.A.Yagneyshev, B.S., Yagnysheva, T.A., Khmelevskiy, V.A.Practical significance of lithogeochemical characteristics of secondary dispersion aureoles near kimberlites.(Russian)Mineralogischeskiy Sbornik, (L'vov), (Russian), Vol. 43, No. 2, pp. 77-82.Russia, YakutiaGeochemistry, Siberian Platform
DS200512-0987
2004
YagovkinaSimakov, 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
DS201312-0956
2013
Yahata, N.Wang, Y., Hilairet, N., Nishiyama, N., Yahata, N., Tsuchiya, T., Morad, G., Fiquet, G.High pressure, high temperature deformation of CaGeO3 ( perovskite) +-MgO aggregates: implications for multiphase rheology of the lower mantle.Geochemistry, Geophysics, Geosystems: G3, Vol. 14, 9, pp. 3389-3408.MantlePerovskite
DS200912-0829
2009
Yahoo FinanceYahoo FinanceMemorial diamonds deliver eternal life. Algordanza ( from ashes or hair).Finance.yahoo.com, June 23, 1/2p.TechnologyNews item - Algordanza
DS1995-1179
1995
Yajima, H.Matsuda, J.I., Kasumi, A., Yajima, H.Noble gas studies in diamond synthesized shock loading in laboratory And implications on origin in ureilites.Geochim. Cosmochimica Acta, Vol. 59, No. 23, Dec. 1, pp. 4939-4950.GlobalUreilites
DS201312-0988
2013
Yajima, T.Yajima, T., Yamaguchi, Y.Geological mapping of the Francistown area in northeastern Botswana by surface temperature and spectral emissivity information derived from advanced spaceborn thermal emission and reflection radiometer (ASTER) thermal infrared data.Ore Geology Reviews, Vol. 53, pp. 134-144.Africa, BotswanaGeothermometry - Aster
DS1993-1786
1993
Yakarov, K.T.Yakarov, K.T.Placer mining by Almazy Rossii Sakha CompanyDiamonds of Yakutia, pp. 161-162.Russia, YakutiaMining, Alluvials
DS201212-0798
2012
Yakob, J.L.Yakob, J.L., Feineman, M.D., Deane, J.A., Eggler, D.H., Penniston-Dorland, S.C.Lithium partitioning between olivine and diopside at upper mantle conditions: as experimental study.Earth and Planetary Science Letters, Vol. 329-330, pp. 11-21.MantleTechnology
DS1985-0600
1985
Yakol.Serebrya, N.R., Losev, V.G., Voronov, O.A., Rakmani, A.V., Yakol.The Morphology of Diamond Crystals Synthesized from Hydrocarbons. a Technical Note.Kristallogr., Vol. 30, No. 5, PP. 1026-1027.RussiaDiamond Morphology, Synthetics
DS201811-2585
2018
Yakolev, D.Kostrovitsky, S., Yakolev, D.Deciphering kimberlite field structure using ilmenite composition: example of Daldyn field ( Yakutia).European Journal of Mineralogy, doi.org./ 101127/ejm/2018/0030-2783 cost $ 30.00 USRussiadeposit - Daldyn

Abstract: The spatial distribution patterns of Mg-bearing ilmenite (Ilm) composition were studied on 54 kimberlite bodies of the Daldyn field in the Yakutian kimberlite province. The representativity of the ilmenites sampled in this study is ensured by analysing ca. 100 grains from each kimberlite body. The major conclusions are as follows: (1) ilmenites from neighbouring pipes within the same linear cluster have similar average compositions and compositional fields on the MgO-Cr2O3 plots; (2) ilmenites from different clusters of pipes show different average compositions and compositional fields on the MgO-Cr2O3 plots. (3) regardless of belonging to different clusters, low-Mg Ilm across the whole Daldyn field is characterized by a direct correlation between Al2O3 and MgO; (4) significant changes of MgO content are observed in high-Mg Ilm, while Al2O3 content remains at the same level. The similarity of Ilm compositions across the kimberlite field, as shown by the MgO-Al2O3 plots, is due to a common asthenospheric source. The similar Ilm compositions in different bodies within cluster of pipes is accounted for by a single supply of magma via a lithospheric mantle channel for all pipes of the cluster. The composition of the kimberlite melts can be altered owing to the incorporation and assimilation of lithospheric mantle rocks rich in Mg and Cr. These changes of the melt cause corresponding changes in the Ilm macrocryst composition, both during and after crystallization of Ilm. Thus, the Ilm macrocryst composition follows a trend from low-Mg/low-Cr for Ilm crystallizing in the asthenosphere, to high-Mg/high-Cr at higher levels in the lithosphere. The key conclusion of this study is that Ilm can be used to decipher the structure of kimberlite fields. This can provide a reliable geological criterion for grouping an association of pipes together in clusters, which were previously identified only through subjective considerations of the spatial proximity of kimberlite bodies.
DS201212-0376
2012
Yakolev, D.A.Kostrovitskii, S.I., Soloveva, L.V., Gornova, M.A., Alymova, N.V., Yakolev, D.A., Ignative, A.V., Velivetskaya, T.A., Suvorova, L.F.Oxygen isotope composition in minerals of mantle parageneses from Yakutian kimberlites.Doklady Earth Sciences, Vol. 444, 1, pp. 579-584.Russia, YakutiaDeposit - Udachnaya, Komsomolskaya
DS201212-0377
2012
Yakolev, D.A.Kostrovitsky, S.I., Kopylova, M.G., Egorov, K.N., Yakolev, D.A., Kalashnikova, T.V., Sandmirova, G.P.The exceptionally fresh Udachnaya -East kimberlite: evidence for brine and evaporite contamination.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractRussia, YakutiaDeposit - Udachnaya -east
DS201212-0378
2012
Yakolev, D.A.Kostrovitsky, S.I.,Gornova, M.A.,Solovyevas, L.V., Yakolev, D.A.Isotope heterogeneity from oxygen in rocks of lithospheric mantle.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussiaDeposit - Udachnaya
DS201212-0799
2012
Yakolev, D.A.Yakolev, D.A., Kostrovitsky, S., Suvorova, L.F.Typomorphic features of groundmass minerals from Diamondiferous kimberlites of Yakutia.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, YakutiaPetrology
DS201603-0392
2016
Yakolev, D.A.Kostrovitsky, S.I., Skuzovatov, S.Y., Yakolev, D.A., Sun, J., Nasdala, L., Wu, F.Age of Siberian craton crust beneath the northern kimberlite fields: insights to the craton evolution. ( Olenek -Anabar)Gondwana Research, in press available 70p.RussiaGeochronology

Abstract: Comprehensive studies of zircon xenocrysts from kimberlites of the Kuoika field (northeastern Siberian craton) and several kimberlite fields of the eastern Anabar shield, along with data compilation on the age of kimberlite-hosting terranes, reveal details of the evolution of the northern Siberian craton. The age distribution and trace element characteristic of zircons from the Kuoika field kimberlites (Birekte terrane) provide evidence of significant basic and alkaline-carbonatite magmatism in northern Siberia in the Paleozoic and Mesozoic periods. The abundance of 1.8-2.1 Ga zircons in both the Birekte and adjacent Hapchan terranes (the latter hosting kimberlites of the eastern Anabar shield) supports the Paleoproterozoic assembly and stabilization of these units in the Siberian craton and the supercontinent Columbia. The abundance of Archean zircons in the Hapchan terrane reflects the input of an ancient source other than the Birekte terrane and addresses the evolution of the terrane to west (Magan and Daldyn terranes of the Anabar shield). The present study has also revealed the oldest known remnant of the Anabar shield crust, whose 3.62 Ga age is similar to that of the other ancient domain of Siberia, the Aldan shield. The first Hf isotope data for the Anabar shield coupled with the U-Pb systematics indicate three stages of crustal growth (Paleoproterozoic, Neoarchean and Paleoarchean) and two stages of the intensive crustal recycling in the Paleoproterozoic and Neoarchean. Intensive reworking of the existing crust at 2.5-2.8 Ga and 1.8-2.1 Ga is interpreted to provide evidence for the assembly of Columbia. The oldest Hf model age estimation provides a link to Early Eoarchean (3.7-3.95 Ga) and possibly to Hadean crust. Hence, some of the Archean cratonic segments of the Siberian craton could be remnants of the Earth's earliest continental crust.
DS202002-0196
2020
Yakolev, D.A.Kostrovitsky, S.I., Yakolev, D.A.The origin of salts in unaltered kimberlites. Comment on Abersteiner article Journal of Petrology, in press available, 13p.Russiadeposit - Udachnaya-East

Abstract: The article by Abersteiner et al., (2018) discussing the mantle origin of salts in serpentine-free kimberlites from the Udachnaya-East pipe contradicts the views of Kostrovitsky et al. (2013) concerning the origin of these salts from a surface source of brines. Here we wish to emphasize that Abersteiner et al. (2018) have presented erroneous statements regarding the genesis of these rocks. On the basis of the data collected by hydrogeologists working at Udachnaya-East we consider that unaltered kimberlites occur at 400-500 m depth, where the brines precipitated salts. The relation of unaltered kimberlites to the surface sources of salt is illustrated by the cross sections of the Mir and International’naya pipes, where serpentine-free kimberlites occur at the depths of Cambrian evaporite host rocks intercalated with thick halite layers. It is assumed that the salts from surface sources prevented olivine serpentinization. The secondary origin of salts in serpentine-free kimberlites is confirmed by our investigations and the hypothesis regarding the mantle origin of salts is doubtful.
DS202005-0743
2020
Yakolev, D.A.Kostrovitsky, S.I., Yakolev, D.A., Soltys, A., Ivanov, A.S., Matsyuk, S.S., Robles-Cruz, S.E.A genetic relationship between magnesian ilmenite and kimberlites of the Yakutian diamond fields.Ore Geology Reviews, Vol. 120, 16p. PdfRussia, Yakutiailmenite

Abstract: We present new major element geochemical data, and review the existing data for ilmenite macrocrysts, megacrysts, as well as ilmenite in mantle xenoliths from four diamondiferous kimberlite fields in the Yakutian province. This combined data set includes 10,874 analyses of ilmenite from 94 kimberlite pipes. In the studied samples we identify various different ilmenite compositional distributions (e.g., “Haggerty's parabola”, or “Step-like” trends in MgO-Cr2O3 bivariate space), which are common to all kimberlites from a given cluster, but the compositional distributions differ between clusters. We propose three stages of ilmenite crystallization: 1) Mg-Cr poor ilmenite crystallising from a primitive asthenospheric melt (the base of Haggerty's parabola on MgO-Cr2O3 plots). 2) This primitive asthenospheric melt was then modified by the partial assimilation of lithospheric material, which enriched the melt in MgO and Cr2O3 (left branch of Haggerty’s parabola). 3) Ilmenite subsequently underwent sub-solidus recrystallization in the presence of an evolved kimberlite melt under increasing oxygen fugacity (ƒO2) conditions (right branch of Haggerty’s parabola in MgO-Cr2O3 plots). Significant differences in the ilmenite compositional distribution between different kimberlite fields are the result of diverse conditions during subsequent ilmenite crystallization in a kimberlite melt ascending through the lithospheric mantle, which have different textures and compositions beneath the studied kimberlite fields. We propose that a TiO2 fluid formed due to immiscibility of an asthenospheric melt with low Cr and high Ti contents. This fluid infiltrated lithospheric mantle rocks forming Mg-ilmenite. These features indicate a genetic link between ilmenite and the host kimberlite melt.
DS200812-0597
2008
Yakolev, D.A.A.Kostrovitsky, S.A.I.A., Alymova, N.A., Yakolev, D.A.A., Solvaceva, L.A.V.A., Gornova, M.A.A.A.Origin of garnet megacrysts from kimberlites.Doklady Earth Sciences, Vol. 420, 1, pp. 636-640.RussiaPetrology
DS1984-0782
1984
Yakolev, E.N.Yakolev, E.N., Voronov, O.A., Rakhmania, A.V.Synthesis of Diamonds from HydrocarbonsSoviet Journal of Superhard Materials, Vol. 6, No. 4, pp. 9-12RussiaDiamond Morphology
DS201910-2256
2019
Yakolev, I.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]
DS1995-2094
1995
Yakolev, L.Ye.Yakolev, L.Ye., Borevskiy, L.V.Interaction between hydrodynamic, chemical and thermal processes in theearth's crustGeochemistry International, Vol. 32, No. 4, pp. 96-107GlobalGeochemistry
DS201906-1283
2018
Yakolev, V.N.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.
DS1988-0502
1988
Yakolev, Ya.V.Nekrasov, I.Ya., Yakolev, Ya.V., Pavlova, L.A., Gotovtsev, V.V.Unusual inclusions in native gold from the Mir kimberlite pipeDokl. Acad. Sciences USSR Earth Science Section, Vol. 303, No. 6, pp. 160-164RussiaDiamond inclusions, Gold
DS1991-1901
1991
Yakolev, Yu.N.Yakolev, Yu.N., Distler, V.V., Mitrofanov, F.P., et al.Mineralogy of platinum group elements (PGE) in the mafic-ultramafic massifs of the Kola regionMin. Petrol, Vol. 43, No. 3, February pp. 181-192RussiaPlatinuM., Mafic-ultramafic
DS200912-0830
2009
Yakoleva, O.S.Yakoleva, O.S., et al.Mineralogical and geochemical features of high alumin a fenites of the Mont Saint Hilaire alkaline complex, Quebec, Canada.alkaline09.narod.ru ENGLISH, May 10, 2p. abstractCanada, QuebecCarbonatite
DS200812-0151
2008
Yakoleva, S.Z.Buchko, I.V., Sorokin, A.P., Yakoleva, S.Z., Plotkina, Y.V.Petrology of the Early Mesozoic ultramafic mafic Luchin a massif ( southeastern periphery of the Siberian Craton).Russian Geology and Geophysics, Vol. 49, 8, pp. 570-581.RussiaUltramafic rocks
DS201112-0902
2011
Yakoleva, S.Z.Salknikova, E.B., Yakoleva, S.Z., Kotov, A.B., Plotkina, Yu.V.TIMS U-Pb dating of bastnasite, calzitite and tantalite as a powerful tool for timing of rare metal granites and carbonatites, (Eastern Siberia).Goldschmidt Conference 2011, abstract p.1785.RussiaGeochronology
DS200612-0908
2006
YakovenchukMenishikov, Y.P., Krivovichev, S.V., Pakhomovsky, Yakovenchuk, Ivanyuk, Mikhailova, Armbruster,SelivanovaChivruaiite, Ca(Ti,Nb)5(Si6O17)2 (OH,O)5.13-14H20, a new mineral from hydrothermal veins of Khibiny and Lovozero alkaline massifs.American Mineralogist, Vol. 91, 5-6, May pp. 922-928.Russia, Kola PeninsulaMineralogy - alkaline
DS1997-0175
1997
Yakovenchuk, V.Chakhmouradian, A., Yakovenchuk, V., Mitchell, R.H.Isolueshite: a new mineral of the perovskite group from Khibin a alkalinecomplex.European Journal of Mineralogy, Vol. 9, pp. 483-490.Russia, Kola PeninsulaMineralogy, Ijolite, urtite
DS1994-0120
1994
Yakovenchuk, V.N.Bayanova, T.B., Yakovenchuk, V.N.uranium-lead (U-Pb) dating of baddeleyite and zircon from imandrites on the Kolapeninsula.Doklady Academy of Sciences Acad. Science USSR, Vol. 323, No. 2, June pp. 147-150.Russia, Kola PeninsulaGeochronology
DS2003-0751
2003
Yakovenchuk, V.N.Krivovichev, S.V., Armbruster, T., Yakovenchuk, V.N., Pakhomovsky, Y.A.Crystal structure of Lamprophyllite - 2M and Lamprophyllite -2O from the LovozeroEuropean Journal of Mineralogy, Vol. 15, 4, pp. 711-18.Russia, Kola PeninsulaAlkaline rocks - mineralogy
DS200412-1056
2003
Yakovenchuk, V.N.Krivovichev, S.V., Armbruster, T., Yakovenchuk, V.N., Pakhomovsky, Y.A.Crystal structure of Lamprophyllite - 2M and Lamprophyllite -2O from the Lovozero alkaline massif, Kola Peninsula, Russia.European Journal of Mineralogy, Vol. 15, 4, pp. 711-18.Russia, Kola PeninsulaAlkaline rocks, mineralogy
DS200712-1195
2007
Yakovenchuk, V.N.Yakovenchuk, V.N., Pakhomovsky,Y.A., Menshikov, Y.P., Mikhailova, J.A., Ivanyuk, G.Y., Zalkind, O.A.Krivovichevite a new mineral species from the Lovozero alkaline massif, Kola Peninsula, Russia.The Canadian Mineralogist, Vol. 45, 3, pp. 451-456.Russia, Kola PeninsulaAlkaline rocks, mineralogy
DS200712-1196
2007
Yakovenchuk, V.N.Yakovenchuk, V.N., Pakhomovsky,Y.A., Menshikov, Y.P., Mikhailova, J.A., Ivanyuk, G.Y., Zalkind, O.A.Krivovichevite a new mineral species from the Lovozero alkaline massif, Kola Peninsula, Russia.The Canadian Mineralogist, Vol. 45, 3, pp. 451-456.Russia, Kola PeninsulaAlkaline rocks, mineralogy
DS201012-0414
2010
Yakovenchuk, V.N.Krivovichev, S.V., Yakovenchuk, V.N., Zhitova, E.S., Zolotarev, A.A., Pakhomovsky, Y.A., Ivanyuk, G.Yu.Crystal chemistry of natural layered double hydroxides, 1. Quintinite -2H-3c from the Kovdor alkaline massif, Kola Peninsula, Russia.Mineralogical Magazine, Vol. 74, pp. 821-832.Russia, Kola PeninsulaCarbonatite
DS201112-0539
2011
Yakovenchuk, V.N.Korchak, Yu.A., Menshikov, Yu.P., Pakhomovskii, Ya.A., Yakovenchuk, V.N., Ivanyuk, G.Yu.Trap formation of the Kola Peninsula.Petrology, Vol. 19, 1, pp. 87-101.Russia, Kola PeninsulaAlkaline rocks, Lovozero and Khibiny
DS201112-1175
2011
Yakovenchuk, V.N.Zolotarev, A.A., Krivovichev, S.V., Yakovenchuk, V.N., Zhitova, E.S., Pakhomovsky, Y.A., Ivanyuk, G.Y.Crystal chemistry of natural layered double hydroxides from the Kovdor alkaline massif, Kola. Polytypes of quininite: cation ordering and superstructures.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterRussia, Kola PeninsulaAlkalic
DS201507-0325
2015
Yakovenchuk, V.N.Mikhailova, J.A., Kalashnikov, A.O., Sokharev, V.A., Pakhomovsky, Y.A., Konopleva, N.G., Yakovenchuk, V.N., Bazai, A.V., Goryainov, P.M., Ivanyuk, G.Yu.3D mineralogical mapping of the Kovdor phoscorite-carbonatite complex, Russia.Mineralium Deposita, In press available. 19p.RussiaCarbonatite
DS201511-1849
2016
Yakovenchuk, V.N.Kalashnikov, A.O., Yakovenchuk, V.N., Pakhomovsky, Y.A.A., Bazai, A.V., Sokharev, V.A., Konopleva, N.G., Mikhailova, J.A., Goryainov, P.M., Ivanyuk, G.Yu.Scandium of the Kovdor baddeleyite apatite magnetite deposit ( Murmansk region, Russia): mineralogy, spatial distribution, and potential source.Ore Geology Reviews, Vol. 72, pp. 532-537.RussiaCarbonatite
DS201602-0216
2015
Yakovenchuk, V.N.Konopleva, N.G., Ivanyuk, G.Yu., Pakhomovsky, Ya.A., Yakovenchuk, V.N., Mikhailova, Yu.A., Selivanova, E.A.Typochemistry of rinkite and products of its alteration in the Khibiny alkaline pluton, Kola Peninsula.Geology of Ore Deposits, Vol. 57, 7, pp. 614-625.Russia, Kola PeninsulaDeposit - Khibiny

Abstract: The occurrence, morphology, and composition of rinkite are considered against the background of zoning in the Khibiny pluton. Accessory rinkite is mostly characteristic of foyaite in the outer part of pluton, occurs somewhat less frequently in foyaite and rischorrite in the central part of pluton, even more sparsely in foidolites and apatite-nepheline rocks, and sporadically in fenitized xenoliths of the Lovozero Formation. The largest, up to economic, accumulations of rinkite are related to the pegmatite and hydrothermal veins, which occur in nepheline syenite on both sides of the Main foidolite ring. The composition of rinkite varies throughout the pluton. The Ca, Na, and F contents in accessory rinkite and amorphous products of its alteration progressively increase from foyaite and fenitized basalt of the Lovozero Formation to foidolite, rischorrite, apatite-nepheline rocks, and pegmatite-hydrothermal veins.
DS201602-0225
2015
Yakovenchuk, V.N.Menshikov, Yu.P., Mikhailova, Yu.A., Pakhomovsky, Ya.A., Yakovenchuk, V.N., Ivanyuk, G.Yu.Minerals of zirconolite group from fenitized xenoliths in nepheline syenites of Khibiny and Lovozero plutons, Kola Peninsula.Geology of Ore Deposits, Vol. 57, 7, pp. 591-599.Russia, Kola PeninsulaDeposit - Lovozero

Abstract: Zirconolite, its Ce-, Nd-, and Y-analogs, and laachite, another member of the zirconolite group, are typomorphic minerals of the fenitized xenoliths in nepheline syenite and foidolite of the Khibiny-Lovozero Complex, Kola Peninsula, Russia. All these minerals are formed at the late stage of fenitization as products of ilmentie alteration under the effect of Zr-bearing fluids. The diversity of these minerals is caused by the chemical substitutions of Na and Ca for REE, Th, and U compensated by substitution of Ti and Zr for Nb, Fe and Ta, as well as by the redistribution of REE between varieties enriched in Ti (HREE) or Nb (LREE). The results obtained can be used in the synthesis of Synroc-type titanate ceramics assigned for the immobilization of actinides.
DS201602-0226
2016
Yakovenchuk, V.N.Mikhailova, J.A., Kalashnikov, A.O., Sokharev, V.A., Pakhomovsky, Y.A., Konopleva, N.G., Yakovenchuk, V.N., Bazai, A.V., Goryainov, P.M., Ivanyuk, G.Y.3D mineralogical mapping of the Kovdor phoscorite carbonatite complex ( Russia).Mineralium Deposita, Vol. 51, 1, pp. 131-149.RussiaDeposit - Kovdor

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

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

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

Abstract: The comprehensive petrographical, petrochemical and mineralogical study of the Kovdor magnetite-apatite-baddeleyite deposit in the phoscorite-carbonatite complex (Murmansk Region, Russia) revealed a spatial distribution of grain size and chemical composition of three economically extractable minerals — magnetite, apatite, and baddeleyite, showing that zonal distribution of mineral properties mimics both concentric and vertical zonation of the carbonatite-phoscorite pipe.The marginal zone of the pipe consists of (apatite)-forsterite phoscorite carrying fine grains of Ti-Mn-Si-rich magnetite with ilmenite exsolution lamellae, fine grains of Fe-Mg-rich apatite and finest grains of baddeleyite, enriched in Mg, Fe, Si and Mn. The intermediate zone accommodates carbonate-free magnetite-rich phoscorites that carry medium to coarse grains of Mg-Al-rich magnetite with exsolution inclusions of spinel, medium-grained pure apatite and baddeleyite. The axial zone hosts carbonate-rich phoscorites and phoscorite-related carbonatites bearing medium-grained Ti-V-Ca-rich magnetite with exsolution inclusions of geikielite-ilmenite, fine grains of Ba-Sr-Ln-rich apatite and comparatively large grains of baddeleyite, enriched in Hf, Ta, Nb and Sc. The collected data enable us to predict such important mineralogical characteristics of the multicomponent ore as chemical composition and grain size of economic and associated minerals, presence of contaminating inclusions, etc. We have identified potential areas of maximum concentration of such by-products as scandium, niobium and hafnium in baddeleyite and REEs in apatite.
DS201703-0429
2017
Yakovenchuk, V.N.Popova, E., Lushnikov, S.G., Yakovenchuk, V.N.The crystal structure of loparite: a new acentric variety.Mineralogy and Petrology, in press availablePerovskite, REE

Abstract: The crystal structure of the cubic modification of the natural mineral loparite has been studied for the first time by the methods of the X-ray diffraction analysis (?MoK a radiation, 105 independent reflections with I > 3s(I), R = 0.041 in the anisotropic approximation). The structure belongs to the perovskite type (ABO 3) with the double period of the cubic unit cell, a = 7.767(1) Å (sp. gr. Pn3m; Z = 2 for the composition (Ca,Na,Ce)(Na,Ce)3(Ti,Nb)2Ti2O12. Period doubling is explained by ordering of cations both in the A and the B positions.
DS201801-0049
2017
Yakovenchuk, V.N.Popova, E.A., Lushnikov, S.G., Yakovenchuk, V.N., Krivovichev, S.V.The crystal structure of loparite: a new acentric variety.Mineralogy and Petrology, Vol. 111, pp. 827-832.Russia, Kola Peninsuladeposit - Khibiny

Abstract: The crystal structure of a new structural variety of loparite (Na0.56Ce0.21La0.14Ca0.06Sr0.03Nd0.02Pr0.01)S=1.03(Ti0.83Nb0.15)S=0.98O3 from the Khibiny alkaline massif, Kola peninsula, Russia, was solved by direct methods and refined to R1 = 0.029 for 492 unique observed reflections with I > 2s(I). The mineral is orthorhombic, Ima2, a = 5.5129(2), b = 5.5129(2) and c = 7.7874(5) Å. Similarly to other perovskite-group minerals with the general formula ABO3, the crystal structure of loparite is based upon a three-dimensional framework of distorted corner-sharing BO6. The A cations are coordinated by 12 oxygen atoms and are situated in distorted cuboctahedral cavities. In contrast to the ideal perovskite-type structure (Pm3-m), the unit cell is doubled along the c axis and the a and b axes are rotated in the ab plane at 45o. The BO6 octahedron displays distortion characteristic for the d0 transition metal cations with the out-of-center shift of the B site. The symmetry reduction is also attributable to the distortion of the BO6 octahedra which are tilted and rotated with respect to the c axis. The occurrence of a new acentric variety of loparite can be explained by the pecularities of its chemical composition characterized by the increased content of Ti compared to the previously studied samples.
DS201803-0487
2018
Yakovenchuk, V.N.Yakovenchuk, V.N., Yu, G., Pakhomovsky, Y.A., Panikorovskii, T.L., Britvin, S.N., Krivivichev, S.V., Shilovskikh, V.V., Bocharov, V.N.Kampelite, Ba3Mg1.5,Sc4(PO4)6(OH)3.4H2O, a new very complex Ba-Sc phosphate mineral from the Kovdor phoscorite-carbonatite complex ( Kola Peninsula) Russia.Mineralogy and Petrology, Vol. 112, pp. 111-121.Russia, Kola Peninsulacarbonatite - Kovdor
DS201808-1799
2018
Yakovenchuk, V.N.Zhitova, E.S., Krivocichev, S.V., Yakovenchuk, V.N., Ivanyuk, G.Y., Pakhomovsky, Y.A., Mikhailova, J.A.Crystal chemistry of natural layered double hydroxides: 4. Crystal structures and evolution of structural complexity of quintinite polytypes from the Kovdor alkaline ultrabasic massif, Kola Peninsula, Russia.Mineralogical Magazine, Vol. 82, no. 2, pp. 329-346.Russia, Kola Peninsuladeposit - Kovdor

Abstract: Two quintinite polytypes, 3R and 2T, which are new for the Kovdor alkaline-ultrabasic complex, have been structurally characterized. The crystal structure of quintinite-2T was solved by direct methods and refined to R1 = 0.048 on the basis of 330 unique reflections. The structure is trigonal, P c1, a = 5.2720(6), c = 15.113(3) Å and V = 363.76(8) Å3. The crystal structure consists of [Mg2Al(OH)6]+ brucite-type layers with an ordered distribution of Mg2+ and Al3+ cations according to the × superstructure with the layers stacked according to a hexagonal type. The complete layer stacking sequence can be described as …=Ab1C = Cb1A=…. The crystal structure of quintinite-3R was solved by direct methods and refined to R1 = 0.022 on the basis of 140 unique reflections. It is trigonal, R m, a = 3.063(1), c = 22.674(9) Å and V = 184.2(1) Å3. The crystal structure is based upon double hydroxide layers [M2+,3+(OH)2] with disordered distribution of Mg, Al and Fe and with the layers stacked according to a rhombohedral type. The stacking sequence of layers can be expressed as …=?B = BC = CA=… The study of morphologically different quintinite generations grown on one another detected the following natural sequence of polytype formation: 2H ? 2T ? 1M that can be attributed to a decrease of temperature during crystallization. According to the information-based approach to structural complexity, this sequence corresponds to the increasing structural information per atom (IG): 1.522 ? 1.706 ? 2.440 bits, respectively. As the IG value contributes negatively to the configurational entropy of crystalline solids, the evolution of polytypic modifications during crystallization corresponds to the decreasing configurational entropy. This is in agreement with the general principle that decreasing temperature corresponds to the appearance of more complex structures.
DS201905-1046
2019
Yakovenchuk, V.N.Ivanyuk, G.Y., Yakovenchuk, V.N., Panikorovskii, T.L., Konoplyova, N., Pakhomovsky, Y.A., Bazai, A.V., Bocharov, V.N., Krivovichev, S.V.Hydroxynatropyrochlore, ( Na, Ca, Ce)2 Nb2O6(OH), a new member of the pyrochlore group from the Kovdor phoscorite-carbonatite pipe, Kola Peninsula, Russia.Mineralogical Magazine, Vol. 83, pp. 107-113.Russia, Kola Peninsulacarbonatite

Abstract: Hydroxynatropyrochlore, (Na,?a,Ce)2Nb2O6(OH), is a new Na-Nb-OH-dominant member of the pyrochlore supergroup from the Kovdor phoscorite-carbonatite pipe (Kola Peninsula, Russia). It is cubic, Fd-3m, a = 10.3211(3) Å, V = 1099.46 (8) Å3, Z = 8 (from powder diffraction data) or a = 10.3276(5) Å, V = 1101.5(2) Å3, Z = 8 (from single-crystal diffraction data). Hydroxynatropyrochlore is a characteristic accessory mineral of low-carbonate phoscorite of the contact zone of the phoscorite-carbonatite pipe with host foidolite as well as of carbonate-rich phoscorite and carbonatite of the pipe axial zone. It usually forms zonal cubic or cubooctahedral crystals (up to 0.5 mm in diameter) with irregularly shaped relics of amorphous U-Ta-rich hydroxykenopyrochlore inside. Characteristic associated minerals include rockforming calcite, dolomite, forsterite, hydroxylapatite, magnetite,and phlogopite, accessory baddeleyite, baryte, barytocalcite, chalcopyrite, chamosite-clinochlore, galena, gladiusite, juonniite, ilmenite, magnesite, pyrite, pyrrhotite, quintinite, spinel, strontianite, valleriite, and zirconolite. Hydroxynatropyrochlore is pale-brown, with an adamantine to greasy lustre and a white streak. The cleavage is average on {111}, the fracture is conchoidal. Mohs hardness is about 5. In transmitted light, the mineral is light brown, isotropic, n = 2.10(5) (??= 589 nm). The calculated and measured densities are 4.77 and 4.60(5) g•cm-3, respectively. The mean chemical composition determined by electron microprobe is: F 0.05, Na2O 7.97, CaO 10.38, TiO2 4.71, FeO 0.42, Nb2O5 56.44, Ce2O3 3.56, Ta2O5 4.73, ThO2 5.73, UO2 3.66, total 97.65 wt. %. The empirical formula calculated on the basis of Nb+Ta+Ti = 2 apfu is (Na1.02Ca0.73Ce0.09Th0.09 U0.05Fe2+0.02)?2.00 (Nb1.68Ti0.23Ta0.09)?2.00O6.03(OH1.04F0.01)?1.05. The simplified formula is (Na, Ca,Ce)2Nb2O6(OH). The mineral slowly dissolves in hot HCl. The strongest X-ray powderdiffraction lines [listed as (d in Å)(I)(hkl)] are as follows: 5.96(47)(111), 3.110(30)(311), 2.580(100)(222), 2.368(19)(400), 1.9875(6)(333), 1.8257(25)(440) and 1.5561(14)(622). The crystal structure of hydroxynatropyrochlore was refined to R1 = 0.026 on the basis of 1819 unique observed reflections. The mineral belongs to the pyrochlore structure type A2B2O6Y1 with octahedral framework of corner-sharing BO6 octahedra with A cations and OH groups in the interstices. The Raman spectrum of hydroxynatropyrochlore contains characteristic bands of the lattice, BO6, B-O and O-H vibrations and no characteristic bands of the H2O vibrations. Within the Kovdor phoscorite-carbonatite pipe, hydroxynatropyrochlore is the latest hydrothermal mineral of the pyrochlore supergroup, which forms external rims around grains of earlier U-rich hydroxykenopyrochlore and separated crystals in voids of dolomite carbonatite veins. The mineral is named in accordance with the pyrochlore supergroup nomenclature.
DS201912-2795
2019
Yakovenchuk, V.N.Krivovichev, S.V., Yakovenchuk, V.N., Panikorovskii, T.L., Savchenko, E.E., Pakhailova, Yu, A., Selivanova, E.A., Kadyrova, G.I., Ivanyuk, G.Yu.,Krivovchev, S.V.Nikmelnikovite: Ca 12 Fe 2+ Fe 3+3 Al3(SiO4) 6(OH)20: a new mineral from the Kovdor Massif ( Kola Peninsula, Russia)Doklady Earth Sciences, Vol. 488, 2, pp. 1200-1202.Russia, Kola Peninsuladeposit - Kovdor
DS1990-1604
1990
Yakovlev, B.G.Yakovlev, B.G., Matsyuk, S.S., Vishnevskiy, A.A., Chubarov, V.M.Evolution of mineral equilibration temperatures and petrogenesis of the deep mafic ferruginous granulites from Yakutian kimberlite pipes.(Russian)Mineral. Zhurn., (Russian), Vol. 12, No. 4, August pp. 3-15RussiaPetrology, Mineral chemistry
DS201412-0897
2014
Yakovlev, D.Sun, J., Liu, C-Z., Tappe, S., Kostrovitsky, S.I., Wu, F-Y., Yakovlev, D., Yang, Y-H., Yang, J-H.Repeated kimberlite magmatism beneath Yakutia and its relationship to Siberian flood volcanism: insights from in situ U-Pb and Sr-Nd perovskite isotope analysis.Earth and Planetary Science Letters, Vol. 404, Oct. pp. 283-295.Russia, YakutiaKimberlite magmatism
DS200712-0575
2007
Yakovlev, D.A.Kostrovitsky, S.I., Morikyo, T., Serov, I.V., Yakovlev, D.A., Amirzhanov, A.A.Isotope geochemical systematics of kimberlites and related rocks from the Siberian Platform.Russian Geology and Geophysics, Vol. 48, pp. 272-290.RussiaGeochronology
DS200812-1285
2008
Yakovlev, D.A.Yakovlev, D.A., Kostrovitsky, S.I., Alymova, N.V.Mineral composition features from the Upper Muna field, Yakutia.9IKC.com, 3p. extended abstractRussia, YakutiaMineral chemistry - Verhknemunsk
DS201312-0509
2013
Yakovlev, D.A.Kostrovitsky, S.I., Soloveva, L.V., Yakovlev, D.A., Suvorova, L.F., Sandimirova, G.P., Travin, A.V., Yudin, D.S.Kimberlites and megacrystic suite: isotope geochemical studies.Petrology, Vol. 21, 2, pp. 127-144.Russia, YakutiaDeposit - Udachnaya
DS201609-1726
2016
Yakovlev, D.A.Kopylova, M.G., Gaudet, M., Kostrovitsky, S.I., Polozov, A.G., Yakovlev, D.A.Origin of salts and alkali carbonates in the Udachnaya East kimberlite: insights from petrography of kimberlite phases and their carbonate and evaporite xenoliths.Journal of Volcanology and Geothermal Research, in press available 19p.RussiaDeposit - Udachnaya East

Abstract: The Udachnaya East kimberlite is characterized by the presence of chlorides, sulfates and alkali carbonates. This highly atypical mineralogy underpinned a model for an anhydrous alkali-rich primary kimberlite melt, despite the absence of petrographic studies providing textural context to the exotic minerals. The present work documents the petrography of the Udachnaya East kimberlite in order to address this problem. The pipe comprises two varieties of Fort-a-la-Corne type pyroclastic kimberlite, olivine-rich and magmaclast-rich, and coherent kimberlite. These kimberlites entrain xenoliths of limestones, altered shales and siltstones, halite-dominated rocks, dolomites, and coarse calcite rocks. The distinct varieties of the Udachnaya East kimberlite carry different populations of crustal xenoliths, which partially control the mineralogy of the host kimberlite. In magmaclast-rich pyroclastic kimberlite, where halite is absent from the crustal xenoliths, it is not observed in the interclast matrix, or within the magmaclasts. Halite occurs in the interclast matrix of olivine-rich pyroclastic kimberlite, where halite xenoliths are common. Large, ~ 30 cm halite xenoliths are uniquely restricted to the coherent kimberlite and show a strong reaction with it. The halite xenoliths are sourced from depths of - 1500 to - 630 m, where carbonate beds host multiple karst cavities filled with halite and gypsum and occasional sedimentary evaporites. The style of secondary mineralization at Udachnaya depends on whether the kimberlite is coherent or pyroclastic. Shortite, pirssonite and other alkali carbonates replacing calcite and possibly serpentine are abundant only in porous pyroclastic kimberlites of both types and in their shale/siltstone xenoliths. The lower porosity of the coherent kimberlite prevented the interaction of kimberlite with Na brines. Serpentinization localized around halite xenoliths started at temperatures above 500 °C, as indicated by its association with high-temperature iowaite. The model of the “dry” Na and Cl-rich primary kimberlite melt is invalidated on the basis of 1) the restriction of exotic salt minerals to certain kimberlite types and xenoliths; and 2) the absence of halite-rich melt inclusions in olivine of coherent kimberlite.
DS201710-2266
2017
Yakovlev, D.A.Sobolev, N.V., Schertle, H-P., Neuser, R.D., Tomilenko, A.A., Kuzmin, D.V., Loginova, A.M., Tolstov, A.V., Kostrovitsky, S.I., Yakovlev, D.A., Oleinikov, O.B.Formation and evolution of hypabyssal kimberlites from the Siberian craton: part 1 - new insights from cathodluminescence of the carbonates. Anabar and Olenek areaJournal of Asian Earth Sciences, Vol. 145, pt. B, pp. 670-678.Russia, Siberiadeposit - Kuranakh, Kharamay
DS1985-0747
1985
Yakovlev, E.N.Yakovlev, E.N., Shalimov, M.D., Kulikova, L.F., Slesarev, V.N.Synthesis of Diamond from HydrocarbonsZhurn. Fiz. Khim., Vol. 59, No. 6, PP. 1517-1519.RussiaDiamond Crystallography, Morphology
DS1985-0748
1985
Yakovlev, E.N.Yakovlev, E.N., Shalimov, M.D., Kulikova, L.F., Slesarev, V.N.Synthesis of Diamonds from CarbohydratesZhurn. Fiz. Khim., Vol. 59, No. 6, JUNE PP. 1517-1518.RussiaDiamond Sythetic
DS1987-0820
1987
Yakovlev, E.N.Yakovlev, E.N., Voronov, O.A., Rakhmanina, A.V.Polycrystalline diamond aggregates obtained by using hydrocarbons.(Russian)Sverktverd. Mater.(Russian), No. 2, pp. 3-5GlobalDiamond synthesis
DS1999-0577
1999
Yakovlev, E.N.Rakhmania, A.V., Yakovlev, E.N.Experimental modeling of the natural synthesis of polycrystalline diamondGeochemistry International, Vol. 37, No. 7, July pp. 678-82.GlobalDiamond morphology
DS201802-0245
2017
Yakovlev, E.Yu.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.
DS202009-1675
2020
Yakovlev, E.Yu.Yakovlev, E.Yu.Features of radioactive element distribution within the Arkhangelsk diamondiferous province: possible directions for development of isotope-radiogeochemical methods for kimberlite prospecting in complex landscape geology and climate conditions of the subaGeochemistry: Exploration, Environment, Analysis, Vol. 20, pp. 269-279. pdfRussia, Arkangelgeochemisty
DS202004-0532
2020
Yakovlev, G.A.Sharygin, V.V., Britvin, S.N., Kaminsky, F.V., Wirth, R., Nigmatulina, E.N., Yakovlev, G.A., Novoselov, K.A., Murashko, M.N.Ellinaite IMA No. 2019-091 mineral name( gravel of Sorriso creek, Aripuna River).European Journal of Mineralogy, Vol. 32, p. 211.Europe, Israel, South America, Brazil, Mato Grossodiamond inclusion
DS202010-1841
2020
Yakovlev, I.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.
DS202010-1840
2020
Yakovlev, I.V.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.
DS1993-1787
1993
Yakovlev, L.Ye.Yakovlev, L.Ye.The role of metamorphism of the basaltic basement of sedimentary basins incrustal evolutionInternational Geology Review, Vol. 35, No. 1, January pp. 27-47RussiaTectonics, Basins
DS202007-1128
2020
Yakovlev, V.N.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.
DS200512-0625
2005
YakovlevaLevchenkov, O.A., Gaidamako, I.M., Levskii, L.K., Komarov, Yakovleva, Rizvanova, MakeevU Pb age of zircon from the Mir and 325 Let Yakutii pipes.Doklady Earth Sciences, Vol. 400, 1, pp. 99-101.Russia, YakutiaGeochronology
DS200612-0189
2006
YakovlevaBuchko, I.V., Salnikova, E.B., Kotov, A.B., Larin, A.M., Velikoslavinskii, Sorokin, Sorokin, YakovlevaPaleoproterozoic gabbro anorthosites of the Selenga Superterrane, southern framing of the Siberian Craton.Doklady Earth Sciences, Vol. 407, 3, pp. 372-375.Russia, SiberiaTectonics
DS201212-0158
2012
YakovlevaDegtyarev, K.E., Tretyakov, Kotov, Salnikova, Shatagi, Yakovleva, Anismova, PlotkinaThe Chelkar peridotite-gabbronorite pluton ( Kokchetav massif, northern Kazakhstan): formation type and geochronology.Doklady Earth Sciences, Vol. 446, 2, pp. 1162-1166.Russia, KazakhstanGeochronlogy
DS201412-0473
2014
Yakovleva, S.Korikovsky, S., Kotov, A., Salnikova, E., Aranovich, L., Korpechkov, D., Yakovleva, S., Tolmacheva, E., Anisimova, I.The age of the protolith of metamorphic rocks in the southeastern Lapland granulite belt, southern Kola Peninsula: correlation with the Belomorian mobile belt in the context of the problem of Archean eclogites.Petrology, Vol. 22, 2, pp. 91-108.Russia, Kola PeninsulaEclogite
DS200712-0367
2006
Yakovleva, S.V.Golovkov, V.P., Yakovleva, S.V.Electric conductivity of the lower mantle. Methods and results.Geomagnetism and Aeronomy, American Geophysical Union, Vol. 46, 5, pp. 676-681.MantleGeophysics
DS201412-0952
2014
Yakovleva, S.Z.Vladykin, N.V., Kotov, A.B., Borisenko, A.S., Yarmolyuk, V.V., Pokhilenko, N.P., Salnikova, E.B., Travin, A.V., Yakovleva, S.Z.Age boundaries of formation of the Tomtor alkaline ultramafic pluton: U Pb and 40 Ar 39 Ar geochronological studies.Doklady Earth Sciences, Vol. 454, 1, pp. 7-11.RussiaGeochronology
DS201412-0953
2014
Yakovleva, S.Z.Vladykin, N.V., Sotnikov, I.A., Kotov, A.B., Yarmolyuk, V.V., Salnikova, E.B., Yakovleva, S.Z.Structure, age and ore potential of the Burpala rare-metal alkaline Massif, northern Baikal region.Geology of Ore Deposits, Vol. 56, 4, pp. 239-256.RussiaAlkalic
DS1990-1605
1990
Yakovleva, T.P.Yakovleva, T.P., Leskina, L.M., Matyukhin, V.V., Yampolskaya, E.G.Functional state and sickness rate of diamond processing workers. (Russian)Gig Tr Prof. Zabol., (russian), No. 8, pp. 38-42RussiaDiamond processing, Workers
DS2001-1274
2001
Yakubchuk, A.Yakubchuk, A., Seltmann, R., Shatov, V., Cole, A.The Altoids: tectonic evolution and metallogenySeg Newsletter, No. 46, July pp. 1, 7-14.Europe, Siberia, Russia, ChinaCraton, Tectonics
DS2002-1755
2002
Yakubchuk, A.Yakubchuk, A., Cole, A., Seltmann, R., Shatov, V.Tectonic setting, characteristics and regional exploration criteria for gold mineralization...Society of Economic Geologists Special Publication, No.9,pp.177-201.China, Tien ShanOrogeny - Altaid orogenic collage, key example, Deposit - lists
DS201012-0870
2010
Yakubchuk, A.Yakubchuk, A.Restoring the supercontinent Columbia and tracing its fragments after the breakup: a new configuration and Super-Horde hypothesis.Journal of Geodynamics, Vol. 50, 3-4, pp. 166-175.MantleCrustal evolution
DS200612-0574
2005
Yakubchuk, A.S.Herrington, R.J., Puchkov, V.N., Yakubchuk, A.S.A reassessment of the tectonic zonation of the Uralides: implications for metallogeny.Geological Society of London Special Paper, No. 248, pp. 153-166.RussiaTectonics
DS1975-0307
1976
Yakubova, S.A.Kolomiytsev, A.I., Yakubova, S.A.The Columnal Growth Mechanisms of Natural Cubic Diamond Crystals.Zap. Vses. Mineral. Obshch., No. 4, P. 72.RussiaCrystallography
DS1986-0722
1986
Yakubova, S.A.Semenova-Tyan-Shanakaya, A.S., Yakubova, S.A.Internal morphology and microhardness of natural diamond.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR (Russian), Vol. 286, No. 6, pp. 1491-1493RussiaBlank
DS1987-0661
1987
Yakubova, S.A.Semenova-Tyan-Shanskaya, A.S., Yakubova, S.A.Internal morphology and microhardness of natural diamondDokl. Acad. Sciences USSR Earth Science Section, Vol. 286, No. 1-6, September pp. 150-151RussiaBlank
DS2000-1036
2000
Yakubovich, O.V.Yakubovich, O.V., Massa, W., Liferovich, PakhomovskyThe crystal structure of bakhchisaraitsevite: hydrothermal origin from Kovdor phoscorite carbonatiteCanadian Mineralogist, Vol. 38, 4, Aug. pp. 831-8.RussiaCarbonatite, Deposit - Kovdor
DS201610-1889
2016
Yakubovich, O.V.Mochalov, A.G., Yakubovich, O.V., Bortnikov, N.S.190Pt-4He age of PGE ores in the alkaline ultramafic Kondyor Massif ( Khabarovsk district) Russia.Doklady Earth Sciences, Vol. 469, 2, pp. 846-850.RussiaAlkalic

Abstract: A new 190Pt-4He method for dating isoferroplatinum has been developed at the Institute of Precambrian Geology and Geochronology, Russian Academy of Sciences. Here we publish the first results of dating of isoferroplatinum from the main mineralogical and geochemical types of PGE mineralization in dunite. The obtained 190Pt-4He age of isoferroplatinum is 129 ± 6 Ma. The gained 190Pt-4He age of isoferroplatinum specimens of different genesis (magmatic, fluid-metamorphogenic, and metasomatic) from the Kondyor Massif indicates that the PGM mineralization took place synchronously and successively with evolution of primarily picrite, followed by subalkaline and alkaline melts of the Mesozoic tectonic-magmatic activation of the Aldan Shield.
DS1982-0647
1982
Yakubovskaya, N.YE.Yakubovskaya, N.YE., Ilupin, I.P.Magnetic Properties of Picroilmenite of Siberian KimberlitesMineral. Zhurn., No. 4, PT. 5, PP. 36-43.RussiaBlank
DS1999-0217
1999
Yakushev, A.I.Filmonova, L.G., Yakushev, A.I.Zonation in almondine garnets from eclogite microxenoliths indicator metamorphism subduction zone.Proceedings Russ. Min. Soc., *RUSS, Vol. 28, No. 1, pp. 54-62.MantleSubduction zone
DS1988-0671
1988
Yakushev, V.M.Storozhenko, L.E., Tsaur, G.I., Yakushev, V.M.Age and genesis of diamond bearing formations of Volynskii quarry (western slope of the Ural)technical note. (Russian)Izv. Akad Nauk SSSR, Ser. Geol., (Russian), No. 5, May pp. 131-133RussiaGeochronology, Volynskii
DS1992-1711
1992
YakutalmazYakutalmazColourful brochure of the operations and objectives of this associationYakutalmaz Association, Brochure handout by WGM at PDA 55p.Russia, Commonwealth of Independent States (CIS), YakutiaCompany brochure, Yakutalmaz
DS1993-1788
1993
Yakutin, V.E.Yakutin, V.E.Alluvial diamond deposits of western Yakutia: methods of evaluation andexploration.Diamonds of Yakutia, pp. 103-104.Russia, YakutiaAlluvials, Evaluation
DS202002-0187
2020
Yakymchuk, C.Gardiner, N.J., Kirkland, C.L., Hollis, J.A., Cawood, P.A., Nebel, O., Szilas, K., Yakymchuk, C.North Atlantic craton architecture revealed by kimberlite-hosted crustal zircons.Earth and Planetary Science Letters, Vol. 534, 8p. PdfEurope, Greenlandkimberlite genesis

Abstract: Archean cratons are composites of terranes formed at different times, juxtaposed during craton assembly. Cratons are underpinned by a deep lithospheric root, and models for the development of this cratonic lithosphere include both vertical and horizontal accretion. How different Archean terranes at the surface are reflected vertically within the lithosphere, which might inform on modes of formation, is poorly constrained. Kimberlites, which originate from significant depths within the upper mantle, sample cratonic interiors. The North Atlantic Craton, West Greenland, comprises Eoarchean and Mesoarchean gneiss terranes - the latter including the Akia Terrane - assembled during the late Archean. We report U-Pb and Hf isotopic, and trace element, data measured in zircon xenocrysts from a Neoproterozoic (557 Ma) kimberlite which intruded the Mesoarchean Akia Terrane. The zircon trace element profiles suggest they crystallized from evolved magmas, and their Eo-to Neoarchean U-Pb ages match the surrounding gneiss terranes, and highlight that magmatism was episodic. Zircon Hf isotope values lie within two crustal evolution trends: a Mesoarchean trend and an Eoarchean trend. The Eoarchean trend is anchored on 3.8 Ga orthogneiss, and includes 3.6-3.5 Ga, 2.7 and 2.5-2.4 Ga aged zircons. The Mesoarchean Akia Terrane may have been built upon mafic crust, in which case all zircons whose Hf isotopes lie within the Eoarchean trend were derived from the surrounding Eoarchean gneiss terranes, emplaced under the Akia Terrane after ca. 2.97 or 2.7 Ga, perhaps during late Archean terrane assembly. Kimberlite-hosted peridotite rhenium depletion model ages suggest a late Archean stabilization for the lithospheric mantle. The zircon data support a model of lithospheric growth via tectonic stacking for the North Atlantic Craton.
DS1860-0482
1885
Yale, C.G.Yale, C.G.California Diamonds, 1885West American Scientist., Vol. 2, P. 60.United States, CaliforniaDiamond Occurrence
DS1983-0637
1983
Yale, L.B.Yale, L.B.An Investigation of Serpentinization and RodingitizationMsc. Thesis, Stanford Univ, 113pGlobalBlank
DS1998-1608
1998
Yale, L.B.Yale, L.B., Carpenter, S.J.Large igneous provinces and giant dike swarms: proxies for supercontinent cyclicity and mantle convection.Earth and Planetary Science Letters, Vol. 163, No. 1-4, Nov. pp. 109-122.MantleSupercontinent cycle, Dike swarms
DS201811-2620
2015
Yaluma, C.B.Yaluma, C.B.How Zambia transformed its emerald industry.InColor, December pp. 18-19.Africa, Zambiaemeralds
DS200812-1286
2008
YamadaYamaguchi, H.,Kudo, Y., Masuzawa, T., Kudo, M., Yamada, Takakuwa, OkanoCombine x-ray photoelectron spectroscopy/ultraviolet photoelectron spectroscopy/field emission spectroscopy for characterization of electron emmision of diamond.Journal of Vacuum Science and Technology B Microelectronics and Nanometer Structures, Vol. 26, 2, pp. 730-734. American Vacuum SocietyTechnologyDiamond emission
DS200812-1288
2008
Yamada, A.Yamamoto, J., Ando, J-i., Kagi, H., Inoue, T., Yamada, A., Yamazaki, D., Irifune, T.In situ strength measurements on natural upper mantle minerals.Physics and Chemistry of Minerals, Vol. 35, pp. 249-257.MantleRheology, geocbarometry
DS201903-0513
2018
Yamada, A.Greaux, S., Yamada, A.Density variations of Cr-rich garnets in the upper mantle inferred from the elasticity of uvarovite garnet.Comptes Rendu Geoscience, doi.org/10.16/ j.crte.2018.09.012 9p.MantleUHP

Abstract: The thermoelastic parameters of Ca3Cr2Si3O12 uvarovite garnet were examined in situ at high pressure up to 13 GPa and high temperature up to 1100 K by synchrotron radiation energy-dispersive X-ray diffraction within a 6-6-type multi-anvil press apparatus. A least-square fitting of room T data to a third-order Birch-Murnaghan (BM3) EoS yielded K0 = 164.2 ± 0.7 GPa, V0 = 1735.9 ± 0.3 Å3 (K’0 fixed to 4.0). P-V-T data were fitted simultaneously by a modified HT-BM3 EoS, which gave the isothermal bulk modulus K0 = 163.6 ± 2.6 GPa, K’0 = 4.1 ± 0.5, its temperature derivative (?K0,T/?T)P = -0.014 ± 0.002 GPa K-1, and the thermal expansion coefficients a0 = 2.32 ± 0.13 ×10-5 K-1 and b0 = 2.13 ± 2.18 ×10-9 K-2 (K’0 fixed to 4.0). Our results showed that the Cr3+ enrichment in natural systems likely increases the density of ugrandite garnets, resulting in a substantial increase of mantle garnet densities in regions where Cr-rich spinel releases chromium through a metasomatic reaction.
DS201905-1035
2019
Yamada, A.Greaux, S., Yamada, A.Density variations of Cr-rich garnets in the upper mantle inferred from the elasticity of uvarovite garnet.Comptes Rendus Geoscience, in press available 9p.Mantlegarnets

Abstract: The thermoelastic parameters of Ca3Cr2Si3O12 uvarovite garnet were examined in situ at high pressure up to 13 GPa and high temperature up to 1100 K by synchrotron radiation energy-dispersive X-ray diffraction within a 6-6-type multi-anvil press apparatus. A least-square fitting of room T data to a third-order Birch-Murnaghan (BM3) EoS yielded K0 = 164.2 ± 0.7 GPa, V0 = 1735.9 ± 0.3 Å3 (K’0 fixed to 4.0). P-V-T data were fitted simultaneously by a modified HT-BM3 EoS, which gave the isothermal bulk modulus K0 = 163.6 ± 2.6 GPa, K’0 = 4.1 ± 0.5, its temperature derivative (?K0,T/?T)P = -0.014 ± 0.002 GPa K-1, and the thermal expansion coefficients a0 = 2.32 ± 0.13 ×10-5 K-1 and b0 = 2.13 ± 2.18 ×10-9 K-2 (K’0 fixed to 4.0). Our results showed that the Cr3+ enrichment in natural systems likely increases the density of ugrandite garnets, resulting in a substantial increase of mantle garnet densities in regions where Cr-rich spinel releases chromium through a metasomatic reaction.
DS1984-0783
1984
Yamada, H.Yamada, H., Takahashi, E.Subsolidus Phase Relations between Coexisting Garnet and Two Pyroxenes at 50 to 100 Kilobar in the System Cao Mgo Al2ossio2.Proceedings of Third International Kimberlite Conference, Vol. 2, PP. 247-255.GlobalGarnet, Composition, Analyses
DS200412-0962
2004
Yamada, H.Katusra, T., Yamada, H., Nishikawa, O., Maoshuang, K., et al.Olivine wadsleyite transition in the system MgFe 2SiO4.Journal of Geophysical Research, Vol. 109, B2, 10.1029/2003 JB002438TechnologyMineral chemistry
DS200812-1287
2008
Yamada, T.Yamaguchi, H., Salto, I., Kudi, Y., Masuzawa, T., Yamada, T., Kudo, M., Takakuma, Y., Okano, K.Electron emission mechanism of hydrogeneated natural type IIb diamond (111).Diamond and Related Materials, Vol. 17, 2, pp. 162-166.TechnologyType II diamonds
DS1993-0792
1993
Yamaguch, A.Kawarada, H., Yamaguch, A.Excitonic recomnbination radiation as characterization of diamonds usingcathodluminescenceDiamond Relat, Vol. 2, No. 2-4, March 31, pp. 100-105GlobalDiamond morphology, Cathodluminescence
DS200412-0843
2004
Yamaguchi, A.Hokada, T., Misawa, K., Yokoyama, K., Shiraishi, K., Yamaguchi, A.SHRIMP and electron microprobe chronology of UHT metamorphism in the Napier Complex, East Antarctica implications for zircon groContributions to Mineralogy and Petrology, Vol. 147, 1, pp. 1-20.AntarcticaGeochronology
DS200812-1286
2008
Yamaguchi, H.Yamaguchi, H.,Kudo, Y., Masuzawa, T., Kudo, M., Yamada, Takakuwa, OkanoCombine x-ray photoelectron spectroscopy/ultraviolet photoelectron spectroscopy/field emission spectroscopy for characterization of electron emmision of diamond.Journal of Vacuum Science and Technology B Microelectronics and Nanometer Structures, Vol. 26, 2, pp. 730-734. American Vacuum SocietyTechnologyDiamond emission
DS200812-1287
2008
Yamaguchi, H.Yamaguchi, H., Salto, I., Kudi, Y., Masuzawa, T., Yamada, T., Kudo, M., Takakuma, Y., Okano, K.Electron emission mechanism of hydrogeneated natural type IIb diamond (111).Diamond and Related Materials, Vol. 17, 2, pp. 162-166.TechnologyType II diamonds
DS201810-2326
2018
Yamaguchi, R.Guotana, J.M., Morishita, T., Yamaguchi, R., Nishio, I., Tamura, A., Tani, K., Harigane, Y., Szilas, K., Pearson, D.G.Contrasting textural and chemical signatures of chromitites in the Mesoarchean Ulamertoq peridotite body, southern West Greenland.MDPI Geosciences, Researchgate 19p.Europe, Greenlandperidotite

Abstract: Peridotites occur as lensoid bodies within the Mesoarchaean orthogneiss in the Akia terrane of Southern West Greenland. The Ulamertoq peridotite body is the largest of these peridotites hosted within the regional orthogneiss. It consists mainly of olivine, orthopyroxene, and amphibole-rich ultramafic rocks exhibiting metamorphic textural and chemical features. Chromitite layers from different localities in Ulamertoq show contrasting characteristics. In one locality, zoned chromites are hosted in orthopyroxene-amphibole peridotites. Compositional zonation in chromites is evident with decreasing Cr and Fe content from core to rim, while Al and Mg increase. Homogeneous chromites from another locality are fairly uniform and Fe-rich. The mineral chemistry of the major and accessory phases shows metamorphic signatures. Inferred temperature conditions suggest that the zoned chromites, homogeneous chromites, and their hosts are equilibrated at different metamorphic conditions. In this paper, various mechanisms during the cumulus to subsolidus stages are explored in order to understand the origin of the two contrasting types of chromites.
DS201811-2575
2018
Yamaguchi, R.Guotana, J.M., Morishita, T., Yamaguchi, R., Nishio, I., Tamura, A., Harigane, Y., Szilas, K., Pearson, G.Contrasting textural and chemical signatures of chromitites in the Mesoarchean Ulamertoq peridotite body, southern West Greenland.Geosciences, Vol. 8, no. 9, p. 328-Europe, Greenlandperidotite

Abstract: Peridotites occur as lensoid bodies within the Mesoarchaean orthogneiss in the Akia terrane of Southern West Greenland. The Ulamertoq peridotite body is the largest of these peridotites hosted within the regional orthogneiss. It consists mainly of olivine, orthopyroxene, and amphibole-rich ultramafic rocks exhibiting metamorphic textural and chemical features. Chromitite layers from different localities in Ulamertoq show contrasting characteristics. In one locality, zoned chromites are hosted in orthopyroxene-amphibole peridotites. Compositional zonation in chromites is evident with decreasing Cr and Fe content from core to rim, while Al and Mg increase. Homogeneous chromites from another locality are fairly uniform and Fe-rich. The mineral chemistry of the major and accessory phases shows metamorphic signatures. Inferred temperature conditions suggest that the zoned chromites, homogeneous chromites, and their hosts are equilibrated at different metamorphic conditions. In this paper, various mechanisms during the cumulus to subsolidus stages are explored in order to understand the origin of the two contrasting types of chromites.
DS1981-0434
1981
Yamaguchi, S.Yamaguchi, S.The Use of Active Carbon for the Synthesis of DiamondZeitschr. Fur Physik. Chemie (leipzig), Vol. 262, No. 4, PP. 131-145.GlobalDiamond Sythesis
DS201703-0407
2017
Yamaguchi, T.Iizuka, T., Yamaguchi, T., Itano, K., Hibiya, Y., Suzuki, K.What Hf isotopes in zircon tell us about crust mantle evolution.Lithos, Vol. 274-275, pp. 304-327.MantleGeochronology

Abstract: The 176Lu-176Hf radioactive decay system has been widely used to study planetary crust-mantle differentiation. Of considerable utility in this regard is zircon, a resistant mineral that can be precisely dated by the U-Pb chronometer and record its initial Hf isotope composition due to having low Lu/Hf. Here we review zircon U-Pb age and Hf isotopic data mainly obtained over the last two decades and discuss their contributions to our current understanding of crust-mantle evolution, with emphasis on the Lu-Hf isotope composition of the bulk silicate Earth (BSE), early differentiation of the silicate Earth, and the evolution of the continental crust over geologic history. Meteorite zircon encapsulates the most primitive Hf isotope composition of our solar system, which was used to identify chondritic meteorites best representative of the BSE (176Hf/177Hf = 0.282793 ± 0.000011; 176Lu/177Hf = 0.0338 ± 0.0001). Hadean-Eoarchean detrital zircons yield highly unradiogenic Hf isotope compositions relative to the BSE, providing evidence for the development of a geochemically enriched silicate reservoir as early as 4.5 Ga. By combining the Hf and O isotope systematics, we propose that the early enriched silicate reservoir has resided at depth within the Earth rather than near the surface and may represent a fractionated residuum of a magma ocean underlying the proto-crust, like urKREEP beneath the anorthositic crust on the Moon. Detrital zircons from world major rivers potentially provide the most robust Hf isotope record of the preserved granitoid crust on a continental scale, whereas mafic rocks with various emplacement ages offer an opportunity to trace the Hf isotope evolution of juvenile continental crust (from eHf[4.5 Ga] = 0 to eHf[present] = + 13). The river zircon data as compared to the juvenile crust composition highlight that the supercontinent cycle has controlled the evolution of the continental crust by regulating the rates of crustal generation and intra-crustal reworking processes and the preservation potential of granitoid crust. We use the data to explore the timing of generation of the preserved continental crust. Taking into account the crustal residence times of continental crust recycled back into the mantle, we further propose a model of net continental growth that stable continental crust was firstly established in the Paleo- and Mesoarchean and significantly grew in the Paleoproterozoic.
DS200412-1736
2004
Yamaguchi, Y.Satoh, H., Yamaguchi, Y., Makino, K.Ti substitution mechanism in plutonic oxy-kaersutite from the Larvik alkaline complex, Oslo Rift, Norway.Mineralogical Magazine, Vol. 68, 4, Aug. 1, pp. 687-697.Europe, NorwayAlkaline rocks, mineralogy
DS200512-0937
2004
Yamaguchi, Y.Satoh, H., Yamaguchi, Y., Makino, K.Ti substitution mechanism in plutonic oxy-kaesutite from the Larvik alkaline complex, Oslo Rift, Norway.Mineralogical Magazine, Vol. 68, 4, Aug. 1,pp. 687-697.Europe, NorwayPetrology - alkaline
DS200512-1211
2005
Yamaguchi, Y.Yamaguchi, Y., Gspann, J.MD study on high energy reactive carbon and oxygen cluster impact leading to surface erosion on diamond.Nuclear Instruments and Methods in Physics Research Section B., Vol. 228, 1-4, pp. 309-314.Diamond morphology
DS201312-0988
2013
Yamaguchi, Y.Yajima, T., Yamaguchi, Y.Geological mapping of the Francistown area in northeastern Botswana by surface temperature and spectral emissivity information derived from advanced spaceborn thermal emission and reflection radiometer (ASTER) thermal infrared data.Ore Geology Reviews, Vol. 53, pp. 134-144.Africa, BotswanaGeothermometry - Aster
DS201905-1037
2019
Yamaguschi, R.Guotana, J.M., Morishita, T., Yamaguschi, R., Nishio, I., Tamura, A., Tani, K., Harigane, Y., Szilas, K., Pearson, D.G.Contrasting textural and chemical signatures of chromitites in the Mesoarchean Ulamertoq peridotite body, southern west Greenland.Geosciences ( MDPI), Vol. 8, 328- 19p.Europe, Greenlandchromitite

Abstract: Peridotites occur as lensoid bodies within the Mesoarchaean orthogneiss in the Akia terrane of Southern West Greenland. The Ulamertoq peridotite body is the largest of these peridotites hosted within the regional orthogneiss. It consists mainly of olivine, orthopyroxene, and amphibole-rich ultramafic rocks exhibiting metamorphic textural and chemical features. Chromitite layers from different localities in Ulamertoq show contrasting characteristics. In one locality, zoned chromites are hosted in orthopyroxene-amphibole peridotites. Compositional zonation in chromites is evident with decreasing Cr and Fe content from core to rim, while Al and Mg increase. Homogeneous chromites from another locality are fairly uniform and Fe-rich. The mineral chemistry of the major and accessory phases shows metamorphic signatures. Inferred temperature conditions suggest that the zoned chromites, homogeneous chromites, and their hosts are equilibrated at different metamorphic conditions. In this paper, various mechanisms during the cumulus to subsolidus stages are explored in order to understand the origin of the two contrasting types of chromites.
DS1992-1712
1992
Yamaji, A.Yamaji, A.Periodic hotspot distribution and small scale convection in the uppermantleEarth and Planetary Science Letters, Vol. 109, No. 1/2, March pp. 107-116MantleMantle convection, Hotspots
DS2002-1179
2002
Yamakata, M.Okada, T., Utsumi, W., Kaneko, H., Yamakata, M., Shimomura, O.In situ observations of the decomposition of brucite diamond conversion in aqueous fluid at high pressure and temperature.Physics and Chemistry of Minerals, Vol. 29, 7, pp. 439-45.GlobalDiamond - UHP, Mineral exploration potential
DS2002-1756
2002
Yamakazi, D.Yamakazi, D., Karoto, S.Fabric development in ( Mg Fe O during large strain, shear deformation: implications for seismic anisotropy in Earth's lower mantle.Physics of the Earth and Planetary Interiors, Vol. 131, 3-4, pp. 251-67.MantleGeophysics - seismics
DS200412-0043
2003
Yamamoto, E.Antonini, P., Comin-Chiaramonti, P., Gomes, C.B., Censi, P., Riffel, B.F., Yamamoto, E.The Early Proterozoic carbonatite complex of Angico dos Dias, Bahia State, Brazil: geochemical and Sr Nd isotopic evidence for aMineralogical Magazine, Vol. 67, 5, pp. 1039-57.South America, BrazilGeochronology, carbonatites
DS2002-1584
2002
Yamamoto, H.Terabayashi, M., Ota, T., Yamamoto, H., Kaneko, Y.Contact metamorphism of the Daulet Suite by solid state emplacement of the Kokchetav UHP HP metamorphic slab.International Geology Review, Vol. 44, 9, pp. 819-30.RussiaUHP
DS201212-0800
2012
Yamamoto, H.Yamamoto, H., Terabayashi, M., Okura, H., Matsui, T., Kanedo, Y.Northward extrusion of the ultrahigh-pressure units in the southern Dabie metamorphic belt, east-central China.Island Arc, in press availableChinaUHP
DS2001-1275
2001
Yamamoto, J.Yamamoto, J., Watanabe, M., Nozaki, SanoHelium and carbon isotopes in fluorites: implications for mantle carbon contribution ancient subduction zoneJournal of Volc. Geotherm. Res., Vol. 107, No. 1-3, pp. 19-26.JapanCarbon - not specific to diamonds
DS2002-1757
2002
Yamamoto, J.Yamamoto, J., Kagi, H., Kaneoka, Lai, Prikhodko,AraiFossil pressures of fluid inclusions in mantle xenoliths exhibiting rheology of mantle minerals...Earth and Planetary Science Letters, Vol.198,3-4,pp.511-19., Vol.198,3-4,pp.511-19.MantleSpectroscopy, Geobarometry - mantle minerals
DS2002-1758
2002
Yamamoto, J.Yamamoto, J., Kagi, H., Kaneoka, Lai, Prikhodko,AraiFossil pressures of fluid inclusions in mantle xenoliths exhibiting rheology of mantle minerals...Earth and Planetary Science Letters, Vol.198,3-4,pp.511-19., Vol.198,3-4,pp.511-19.MantleSpectroscopy, Geobarometry - mantle minerals
DS2003-0697
2003
Yamamoto, J.Kawakami, Y., Yamamoto, J., Kagi, H.Micro raman densimeter for CO2 inclusions in mantle derived mineralsApplied Spectroscopy, Vol. 57, 11, pp. 1333-1339.MantleMineralogy - technology
DS200412-0965
2003
Yamamoto, J.Kawakami, Y., Yamamoto, J., Kagi, H.Micro raman densimeter for CO2 inclusions in mantle derived minerals.Applied Spectroscopy, Vol. 57, 11, pp. 1333-1339.MantleMineralogy - technology
DS200412-1436
2004
Yamamoto, J.Nishio, Y., Nakai, S., Yamamoto, J., Sumino, H., Matsumoto, T., Prikhodko, V.S., Arai, S.Lithium isotopic systematics of the mantle derived ultramafic xenoliths: implications for EMI origin.Earth and Planetary Science Letters, Vol. 217, 3, Jan. 15, pp. 245-261.MantleGeochronology
DS200412-2165
2004
Yamamoto, J.Yamamoto, J., Kaneoka, I., Nakai, S., Kagi, H., Prikhodko, V.S., Arai, S.Evidence for subduction related components in the subcontinental mantle from low 3He/4He and 40Ar/36Ar ratio in mantle xenolithsChemical Geology, Vol. 207, 3-4, July 16, pp. 237-259.RussiaGeochemistry - noble gases, subduction, lherzolite
DS200712-0514
2006
Yamamoto, J.Kawakami, Y., Yamamoto, J., Kagi, H.Micro-raman densimeter for CO2 inclusions in mantle derived minerals.Applied Spectroscopy, Vol. 57, 11, pp. 1333-1339.TechnologyMineral inclusions
DS200712-1197
2007
Yamamoto, J.Yamamoto, J., Kagi, H., Kawakami, Y., Hirano, N., Nakamura, M.Paleo-Moho depth determined from the pressure of CO2 fluid inclusions: Raman spectroscopic barometry of mantle crust derived rocks.Earth and Planetary Science Letters, Vol. 253, 3-4, pp. 369-377.MantleGeothermometry
DS200812-1288
2008
Yamamoto, J.Yamamoto, J., Ando, J-i., Kagi, H., Inoue, T., Yamada, A., Yamazaki, D., Irifune, T.In situ strength measurements on natural upper mantle minerals.Physics and Chemistry of Minerals, Vol. 35, pp. 249-257.MantleRheology, geocbarometry
DS200912-0771
2009
Yamamoto, J.Toyama, C., Muramatsu, Y., Kojitani, H., Yamamoto, J., Nakai, S., Kaneoka, I.Geochemical studies of kimberlites and their constituent minerals from Chin a and South Africa.Goldschmidt Conference 2009, p. A1343 Abstract.ChinaDeposit - Shandong, Liaoning
DS200912-0831
2009
Yamamoto, J.Yamamoto, J.,Nakai, S., Nishimura, K., Kaneoka, I., Sato, K., Okumura, T., Prikhodko,V.S., Arai, S.Intergranular trace elements in mantle xenoliths from Russian Far East: example for mantle metasomatism by hydrous melt.Island Arc, Vol. 18, 1, pp. 225-241.RussiaMetasomatism
DS201012-0878
2010
Yamamoto, J.Yoshikawa, M., Kawamoto, T., Shibata, T., Yamamoto, J.Geochemical and Sr Nd isotopic characteristics and pressure temperature estimates of mantle xenoliths from French Massif Central: metasomatism and carbonatites..Geological Society of London Special Publication, No. 337, pp. 153-175.Europe, FranceCarbonatite
DS201112-1130
2011
Yamamoto, J.Yamamoto, J., Kurz, M.D., Ishibashi, H., Curtice, J.Noble gas isotopic composition of mantle xenoliths in a kimberlite.Goldschmidt Conference 2011, abstract p.2201.Russia, SiberiaKimberlite magma
DS201312-0922
2013
Yamamoto, J.Toyama, C., Muramatsu, Y., Sumino, H., Yamamoto, J., Kaneoka, I.Halogen ratios in kimberlites and their xenoliths related to the origin.Goldschmidt 2013, 1p. AbstractRussia, Africa, South AfricaKimberlite genesis
DS201805-0968
2018
Yamamoto, J.Ono, K., Harada, Y., Yoneda, A., Yamamoto, J., Yoshiasa, A., Sugiyama, K., Arima, H., Watanabe, T.Determination of elastic constants of single crystal chromian spinel by resonant ultrasound spectroscopy and implications for fluid inclusion geobarometry.Physics and Chemistry of Minerals, Vol. 45, 3, pp. 237-247.Technologyxenolths

Abstract: We determined elastic constants of a single-crystal chromian spinel at temperatures from -15 to 45 °C through the Rectangular Parallelepiped Resonance method. The sample is a natural chromian spinel, which was separated from a mantle xenolith. Elastic constants at an ambient temperature (T = 24.0 °C) are C 11 = 264.8(1.7) GPa, C 12 = 154.5(1.8) GPa and C 44 = 142.6(0.3) GPa. All the elastic constants decrease linearly with increasing temperature. The temperature derivatives are dC 11/dT = -0.049(2) GPa/°K, dC 12/dT = -0.019(1) GPa/°K and dC 44/dT = -0.020(1) GPa/°K. As an implication of the elastic constants, we applied them to the correction of a fluid inclusion geobarometry, which utilizes residual pressure of fluid inclusion as a depth scale. Before entrainment by a magma, the fluid inclusions must have the identical fluid density in constituent minerals of a xenolith. It has been, however, pointed out that fluid density of fluid inclusions significantly varies with host mineral species. The present study elucidates that elastic constants and thermal expansion coefficients cannot explain the difference in fluid density among mineral species. The density difference would reflect the difference in the degree of plastic deformation in the minerals.
DS200612-0880
2006
Yamamoto, K.Matsumoto, T., Maruoka, T., Matsuda, J-I., Shimoda, G., Yamamoto, K., Morishita, T., Arai, S.Isotopic compositions of noble gas and carbon in the Archean carbonatites from the Sillinjarvi mine, central Finland.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 21, abstract only.Europe, FinlandCarbonatite, geochronology
DS201511-1854
2015
Yamamoto, M.Kitawaki, H., Hisanaga, M., Yamamoto, M.Type 1b yellow to brownish yellow CVD synthetic diamonds seen at CGL.Journal of Gemmology, Vol. 34, 7, pp. 594-605.TechnologySynthetics

Abstract: In mid-2012, one of the international diamond grading laboratories in Antwerp reported undisclosed CVD synthetic diamonds, causing a stir in the diamond industry (Even-Zohar, 2012). Since then, reports of undisclosed CVD synthetics have also emerged from gem testing laboratories in India and China (D’ Haenens-Johanson et al., 2013; Song et al., 2014). Central Gem Laboratory (CGL) also reported on undisclosed over 1 ct size CVD synthetic diamonds (Kitawaki et al., 2013). Gem quality CVD products have been improved in their size and quality year after year, and a variety of colours have appeared. Most of the CVD synthetic diamonds reported previously are type II, however, recently some yellow CVD synthetic diamonds containing isolated substitutional nitrogen have been supplied to the gem market (Moe et al., 2014; Hainschwang, 2014). This report describes the gemmological features of fifteen yellow to brownish yellow type Ib CVD synthetic diamonds submitted to CGL without disclosure.
DS201901-0044
2018
Yamamoto, M.Kitawaki, H., Emori, K., Hisanaga, M., Yamamoto, M., Okano, M.LPHT treated pink CVD synthetic diamond.Gems & Gemology, Sixth International Gemological Symposium Vol. 54, 3, 1p. Abstract p. 267.Globalsynthetics

Abstract: Pink diamond is extremely popular among fancy-color diamonds, which has prompted numerous attempts to produce pink diamond artificially. Pink CVD synthetic diamonds appeared on the gem market around 2010. Their color was produced by a multistep process combining post-growth HPHT treatment to remove the brown hue and subsequent electron irradiation, followed by low-temperature annealing. Pink CVD synthetic diamonds treated only with low pressure and high temperature (LPHT), without additional post-growth irradiation, have also been reported but are rarely seen on the market. Recently, a loose pink stone (figure 1) was submitted to the Central Gem Laboratory in Tokyo for grading purposes. Our examination revealed that this 0.192 ct brilliant-cut marquise was a CVD synthetic diamond that had been LPHT treated. Visually, this diamond could not be distinguished from natural diamonds with similar color. However, three characteristics of CVD origin were detected: 1. C-H related absorption peaks between 3200 and 2800 cm-1, located with infrared spectroscopy 2. A luminescence peak at 737 nm, detected with photoluminescence (PL) spectroscopy 3. A trace of lamellar pattern seen in the DiamondView However, irradiation-related peaks such as at 1450 cm-1 (H1a), 741.1 nm (GR1), 594.3 nm, or 393.5 nm (ND1) that are seen in the pink CVD diamonds treated with common multi-step processes were not detected. The presence of four peaks at 3123, 2901, 2870, and 2812 cm-1 between 3200 and 2800 cm-1 suggests this stone was LPHT treated; the following observations indicate that it was not HPHT treated: 1) The 3123 cm-1 peak presumably derived from NVH0 disappears after a normal HPHT treatment. 2) The 2901, 2870, and 2812 cm-1 peaks are known to shift toward higher wavenumbers as the annealing temperature rises. Our own HPHT treatment experiments on CVDgrown diamonds proved that the 2902 and 2871 cm-1 peaks detected after 1600°C annealing shifted to 2907 and 2873 cm-1 after 2300°C annealing. The peak shift of 2901, 2870, and 2812 cm-1 is also related to the pressure during the annealing, as these peaks shifted to 2902, 2871, and 2819 cm-1 at the higher pressure of 7 GPa compared to 2900, 2868, and 2813 cm-1 at the ambient pressure under the same annealing temperature of 1600°C. 3) Absorption peaks at 7917 and 7804 cm-1 in the infrared region and at 667 and 684 nm in the visible range were also detected, which coincide with the features seen in LPHTtreated stones. From the combination of the intensity ratios of optical centers such as H3 and NV centers that were detected with PL measurement, this sample is presumed to have been treated with LPHT annealing at about 1500- 1700°C as a post-growth process. In recent years, CVD synthetic diamonds have been produced in a wider range of colors due to progress in the crystal growth techniques and post-growth treatments. Although HPHT treatment has been employed mainly to improve the color in a diamond, LPHT annealing may become widespread as the technique is further developed. Gemologists need to have deep knowledge about the optical defects in such LPHT-treated specimens.
DS200912-0664
2009
Yamamoto, S.Santosh, M., Maruyana, S., Yamamoto,S.The making and breaking od supercontinents: some speculations based on superplumes, super downwelling and the role of tectosphere.Gondwana Research, Vol. 15, 3-4, pp. 324-341.MantlePlume, hotspots
DS201012-0643
2010
Yamamoto, S.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
DS201012-0659
2010
Yamamoto, S.Santosh, M., Maruyama, S., Komiya, T., Yamamoto, S.Orogens in the evolving Earth: from surface continents to 'lost continents'.The evolving continents: understanding processes of continental growth, Geological Society of London, Vol. 338, pp. 77-106.MantleGeodynamics
DS201312-0464
2013
Yamamoto, S.Kawai, K., Yamamoto, S.,Tsuchiya, T., Maruyama, S.The second continent: existence of granitic continental materials around the bottom of the mantle transition zone.Geoscience Frontiers, Vol. 4, 1, pp. 1-6.MantleGranites
DS201612-2278
2016
Yamamoto, S.Azuma, S., Yamamoto, S., Ichikawa, H., Maruyama, S.Why primordial continents were recycled to the deep: role of subduction erosion.Geoscience Frontiers, in press availableMantleSubduction

Abstract: Geological observations indicate that there are only a few rocks of Archean Earth and no Hadean rocks on the surface of the present-day Earth. From these facts, many scientists believe that the primordial continents never existed during Hadean Earth, and the continental volume has kept increasing. On the other hand, recent studies reported the importance of the primordial continents on the origin of life, implying their existence. In this paper, we discussed the possible process that could explain the loss of the primordial continents with the assumption that they existed in the Hadean. Although depending on the timing of the initiation of plate tectonics and its convection style, subduction erosion, which is observed on the present-day Earth, might have carried the primordial continents into the deep mantle.
DS201707-1322
2017
Yamamoto, T.Fei, H., Yamazaki, D., Sakurai, M., Miyajima, N., Ohfuji, H., Katsura, T., Yamamoto, T.A nearly water-saturated mantle transition zone inferred from mineral viscosity. Wadsleyite, ringwooditeScience Advances, Vol. 3, 6, 7p.Mantlewater

Abstract: An open question for solid-earth scientists is the amount of water in Earth’s interior. The uppermost mantle and lower mantle contain little water because their dominant minerals, olivine and bridgmanite, have limited water storage capacity. In contrast, the mantle transition zone (MTZ) at a depth of 410 to 660 km is considered to be a potential water reservoir because its dominant minerals, wadsleyite and ringwoodite, can contain large amounts of water [up to 3 weight % (wt %)]. However, the actual amount of water in the MTZ is unknown. Given that water incorporated into mantle minerals can lower their viscosity, we evaluate the water content of the MTZ by measuring dislocation mobility, a property that is inversely proportional to viscosity, as a function of temperature and water content in ringwoodite and bridgmanite. We find that dislocation mobility in bridgmanite is faster by two orders of magnitude than in anhydrous ringwoodite but 1.5 orders of magnitude slower than in water-saturated ringwoodite. To fit the observed mantle viscosity profiles, ringwoodite in the MTZ should contain 1 to 2 wt % water. The MTZ should thus be nearly water-saturated globally.
DS201911-2534
2019
Yamamoto, T.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.
DS200712-1090
2007
Yamamotto, J.Tooyama, C., Muramatsu, Y., Yamamotto, J., Kaneoka, I.Determin ation of 33 elements in kimberlites from South Africa and Chin a by ICP-MS.Plates, Plumes, and Paradigms, 1p. abstract p. A1030.Africa, South Africa, ChinaShandon, Liaoning
DS200412-1461
2004
Yamanaka, T.Ohtaka, O., Shimono, M., Ohnisi, N., Fukui, H., Takebe, H., Arima, H., Yamanaka, T.,Kikegawa, T., Kume, S.HIP production of a diamond/ SiC composite and application to high pressure anvils.Physics of the Earth and Planetary Interiors, Vol. 143-144, pp. 587-591.TechnologyUHP
DS1995-2095
1995
Yama-Nkounga, A.Yama-Nkounga, A.Some aspects of privatization in the African mining sector and relatedindustriesMinerals Industry International, November pp. 16-17Africa, South AfricaEconomics, Mining
DS1993-0015
1993
Yamaoka, S.Akaishi, M., Kanda, H., Yamaoka, S.Phosphorous: an elemental catalyst for diamond synthesis and growthScience, Vol. 259, No. 5101, March 12, pp. 1592-1593GlobalDiamond synthesis
DS1993-0041
1993
Yamaoka, S.Arima, M., Nakayama, K., Akaishi, M., Yamaoka, S., Kanda, H.Crystallization of diamond from a silicate melt of kimberlite composition in high temperature and high pressure experiments.Geology, Vol. 21, No. 11, November pp. 968-970.GlobalDiamond genesis, Experimental petrology
DS200712-1063
2007
Yamasaki, S.Takuda, N., Saito, T., Umezawa, H., Okushi, H., Yamasaki, S.The role of boron atoms in heavily boron doped semiconducting homoepitaxial diamond growth - study of surface morphology.Diamond and Related Materials, Vol. 16, 2, Feb., pp. 409-411.TechnologyDiamond morphology
DS200712-1086
2007
Yamasaki, S.Tokuda, N., Saito, T., Umezawa, H., Okushi, H., Yamasaki, S.The role of boron atoms in heavily boron-doped semiconducting homoepitaxial diamond growth. Study of surface morphology.Diamond and Related Materials, Vol. 16, 2, pp. 409-411. Ingenta 1070685096TechnologyDiamond morphology
DS1992-1713
1992
Yamashita, H.Yamashita, H., Arima, M.Melting experiment of group II kimberlites up to 10 GPa: petrogenesis Of kimberlite magmaProceedings of the 29th International Geological Congress. Held Japan August 1992, Vol. 2, abstract p. 538GlobalExperimental petrology, Kimberlites
DS1994-0062
1994
Yamashita, H.Arima, M., Yamashita, H., Ohtani, E.Melting experiments of kimberlite up to 8GPa and its bearing onMetasomatismGeological Association of Canada (GAC) Abstract Volume, Vol. 19, p.GlobalPetrology - experimenta, Metasomatism
DS1995-2096
1995
Yamashita, H.Yamashita, H., Arima, M., Ohtani, E.high pressure melting experiments on group II kimberlite up to 8 GPa:implications MetasomatismProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 669-691.GlobalPetrology -experimental, Group II kimberlite
DS1998-1609
1998
Yamashita, H.Yamashita, H., Arima, M., Ohtani, E.Melting experiments of kimberlite compositions up to 9 GPa: determination of melt compositions using aggregate7th International Kimberlite Conference Abstract, pp. 977-9.GlobalExperimental petrology, Mineral chemistry
DS1994-1960
1994
Yamashita, K.Yanagi, T., Yamashita, K.Genesis of continental crust under arc conditionsLithos, Vol. 33, pp. 209-233MantleVolcanics, Subduction - arcs
DS200912-0324
2009
Yamato, P.Husson, L., Brun, J-P., Yamato, P., Faccenna, C.Episodic slab rollback fosters exhumation of HP-UHP rocks.Geophysical Journal International, Vol. 179, 3, pp. 1291-1300.MantleUHP
DS201312-0112
2014
Yamato, P.Burov, E., Francois, T., Yamato, P., Wolf, S.Mechanisms of continental subduction and exhumation of HP and UHP rocks.Gondwana Research, Vol. 25, pp. 464-493.MantleSubduction
DS201412-0085
2014
Yamato, P.Burov, E., Francois, T., Yamato, P., Wolf, S.Mechanisms of continental subduction and exhumation of HP and UHP rocks.Gondwana Research, Vol. 25, pp. 464-493.MantleSubduction, Eclogites
DS201702-0255
2016
Yamato, P.Yamato, P., Brun, J.P.Metamorphic record of catastrophic pressure drop in subduction zones.Nature Geoscience, Vol. 10, pp. 46-50.MantleSubduction

Abstract: When deeply buried in subduction zones, rocks undergo mineral transformations that record the increase of pressure and temperature. The fact that high-pressure metamorphic parageneses are found at the Earth’s surface proves that rock burial is followed by exhumation. Here we use analysis of available data sets from high-pressure metamorphic rocks worldwide to show that the peak pressure is proportional to the subsequent decompression occurring during the initial stage of retrogression. We propose, using a simple mechanical analysis, that this linear relationship can be explained by the transition from burial-related compression to extension at the onset of exhumation. This major switch in orientation and magnitude of principal tectonic stresses leads to a catastrophic pressure drop prior to actual rock ascent. Therefore, peak pressures are not necessarily, as commonly believed, directly dependent on the maximum burial depth, but can also reflect a change of tectonic regime. Our results, which are in agreement with natural data, have significant implications for rock rheology, subduction zone seismicity, and the magnitudes of tectonic pressures sustained by rocks. Current views of subduction dynamics could be reconsidered in that perspective.
DS201909-2108
2019
Yamato, P.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.
DS2002-1319
2002
Yamauchi, J.Reddy, B.J., Yamauchi, J., Reddy, Ravikumar, ChandraseskharOptical and EPR spectra of Ti 3 in lamprophyllite from Kola Peninsula, RussiaNeues Jahrbuch fur Mineralogie - Monatshefte, No.3, March,ppp.138-40.Russia, Kola PeninsulaMineralogy - titanium
DS2002-1175
2002
YamazakiO'Hara, Y., Stern, Ishii, Yurimoto, YamazakiPeridotites from the Mariana Trough: first look at the mantle beneath an active back-arc basin.Contribution to Mineralogy and Petrology, Vol.143,1,pp.1-18., Vol.143,1,pp.1-18.Mariana TroughPeridotites
DS2002-1176
2002
YamazakiO'Hara, Y., Stern, Ishii, Yurimoto, YamazakiPeridotites from the Mariana Trough: first look at the mantle beneath an active back-arc basin.Contribution to Mineralogy and Petrology, Vol.143,1,pp.1-18., Vol.143,1,pp.1-18.Mariana TroughPeridotites
DS2001-1276
2001
Yamazaki, D.Yamazaki, D., Karato, S.I.Some mineral physics constraints on the rheology and geothermal structures of Earth's lower mantle.American Mineralogist, Vol. 86, No. 4, April pp. 385-391.MantleGeothermometry
DS200512-1212
2005
Yamazaki, D.Yamazaki, D., Inoue, T., Okamoto, M., Irifune, T.Grain growth kinetics of ring woodite and its implication for rheology of the subducting slab.Earth and Planetary Science Letters, Advanced in press,MantleSubduction, mantle transition zone
DS200712-1207
2007
Yamazaki, D.Yoshino, T., Yamazaki, D.Grain growth kinetics of CalrO3 perovskite and post-perovskite, with implications for rheology of D' layer.Earth and Planetary Science Letters, Vol. 255, 3-4, March 30, pp. 485-493.MantleD layer
DS200812-1288
2008
Yamazaki, D.Yamamoto, J., Ando, J-i., Kagi, H., Inoue, T., Yamada, A., Yamazaki, D., Irifune, T.In situ strength measurements on natural upper mantle minerals.Physics and Chemistry of Minerals, Vol. 35, pp. 249-257.MantleRheology, geocbarometry
DS201412-0812
2014
Yamazaki, D.Shimojuku, A., Boujibar, A., Yamazaki, D.Growth of ring woodite reaction rims from MgSiO3 perovskite and periclase at 22.5 Gpa and 1,800 C.Physics and Chemistry of Minerals, Vol. 41, 7, pp. 555-567.TechnologyPerovskite
DS201611-2145
2016
Yamazaki, D.Tsujino, N., Yamazaki, D., Takahashi, E.Mantle dynamics inferred from the crystallographic preferred orientation of bridgmanite.Nature, Oct. 20, 15p.MantlePerovskite

Abstract: Seismic shear wave anisotropy1, 2, 3, 4, 5, 6 is observed in Earth’s uppermost lower mantle around several subducted slabs. The anisotropy caused by the deformation-induced crystallographic preferred orientation (CPO) of bridgmanite (perovskite-structured (Mg,Fe)SiO3) is the most plausible explanation for these seismic observations. However, the rheological properties of bridgmanite are largely unknown. Uniaxial deformation experiments7, 8, 9 have been carried out to determine the deformation texture of bridgmanite, but the dominant slip system (the slip direction and plane) has not been determined. Here we report the CPO pattern and dominant slip system of bridgmanite under conditions that correspond to the uppermost lower mantle (25 gigapascals and 1,873 kelvin) obtained through simple shear deformation experiments using the Kawai-type deformation-DIA apparatus10. The fabrics obtained are characterized by [100] perpendicular to the shear plane and [001] parallel to the shear direction, implying that the dominant slip system of bridgmanite is [001](100). The observed seismic shear- wave anisotropies near several subducted slabs1, 2, 3, 4 (Tonga-Kermadec, Kurile, Peru and Java) can be explained in terms of the CPO of bridgmanite as induced by mantle flow parallel to the direction of subduction.
DS201707-1322
2017
Yamazaki, D.Fei, H., Yamazaki, D., Sakurai, M., Miyajima, N., Ohfuji, H., Katsura, T., Yamamoto, T.A nearly water-saturated mantle transition zone inferred from mineral viscosity. Wadsleyite, ringwooditeScience Advances, Vol. 3, 6, 7p.Mantlewater

Abstract: An open question for solid-earth scientists is the amount of water in Earth’s interior. The uppermost mantle and lower mantle contain little water because their dominant minerals, olivine and bridgmanite, have limited water storage capacity. In contrast, the mantle transition zone (MTZ) at a depth of 410 to 660 km is considered to be a potential water reservoir because its dominant minerals, wadsleyite and ringwoodite, can contain large amounts of water [up to 3 weight % (wt %)]. However, the actual amount of water in the MTZ is unknown. Given that water incorporated into mantle minerals can lower their viscosity, we evaluate the water content of the MTZ by measuring dislocation mobility, a property that is inversely proportional to viscosity, as a function of temperature and water content in ringwoodite and bridgmanite. We find that dislocation mobility in bridgmanite is faster by two orders of magnitude than in anhydrous ringwoodite but 1.5 orders of magnitude slower than in water-saturated ringwoodite. To fit the observed mantle viscosity profiles, ringwoodite in the MTZ should contain 1 to 2 wt % water. The MTZ should thus be nearly water-saturated globally.
DS201412-0997
2014
Yambissa, M.T.Yambissa, M.T., Bingham, P.A., Forder, S.D.Mantle conditions and geochemical environment as controls of diamond survival and grade variation in kimberlitic diamond deposits: Lunda Province NE Angola.30th. International Conference on Ore Potential of alkaline, kimberlite and carbonatite magmatism. Sept. 29-, http://alkaline2014.comAfrica, AngolaDiamond grade
DS1989-1143
1989
Yambrick, R.A.Nutt, C.J., Yambrick, R.A.Preliminary geologic map showing igneous related breccias in Cambrian and older quartzites. DrumMountains, UtahUnited States Geological Survey (USGS) Open File, No. 89-0099, 1 sheet 1, 12, 000 $ 3.25UtahDrum Mountains, Breccias
DS1990-1204
1990
Yamnova, N.A.Pushcharovsky, D.Yu., Yamnova, N.A., Nadezhina, T.N.Comparative crystal chemistry of new minerals from alkaline rocksInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 1, extended abstract p. 334-335RussiaAlkaline rocks, Geochemistry
DS1990-0106
1990
Yamoka, S.Akaishi, M., Kanda, H., Yamoka, S.Synthesis of diamond from graphite-carbonate systems under very high temperature and pressureJournal of Crystal Growth, Vol. 104, pp. 578-581GlobalDiamond synthesis, Experimental mineralogy
DS1990-1605
1990
Yampolskaya, E.G.Yakovleva, T.P., Leskina, L.M., Matyukhin, V.V., Yampolskaya, E.G.Functional state and sickness rate of diamond processing workers. (Russian)Gig Tr Prof. Zabol., (russian), No. 8, pp. 38-42RussiaDiamond processing, Workers
DS2001-0072
2001
YanBai, W. Yang, Robinson, Febg, Zhang, Yan, HuStudy of diamonds from chromitites in the Luobusa ophiolite, TibetActa Geologica Sinica, Vol. 75, No. 3, pp. 409-17.China, TibetChromitites - diamond
DS2001-0073
2001
YanBai, W., Yang, J., Fang, Yan, ZhangExplosion of ultrahigh pressure minerals in the mantleActa Geologica Sinica, Vol. 22, No. 5, pp. 385-90.MantleUHP
DS200612-0071
2006
Yan, B.Bai, W., Ren, Y., Yang, J., Fang, Q., Yan, B.The native iron and wustite assemblage: records of oxygen element from the mantle.Acta Geologica Sinica , Vol. 27, 1, pp. 43-50.MantleMineral chemistry
DS201802-0225
2018
Yan, B.Chen, N., Ma, H., Chen, L., Yan, B., Fang, C., Liu, X., Li, Y., Guo, L., Chen, L., Jia, X.Effects of S on the synthesis of type 1b diamond under high pressure and high temperature.International Journal of Refractory Metals & Hard Materials, Vol. 71, pp. 141-146.Technologysynthetic diamonds
DS201312-0539
2013
Yan, C.Liang, Q., Meng, Y., Yan, C., Krasnicki, S., Lai, J., Hemawan, K., Shu,H., Popov, D., Yu,T., Yang, W., Mao, H., Hemley, R.Developments in synthesis, characterization, and application of large high-quality CVD single crystal diamond.Journal of Superhard Materials, Vol. 35, 4, pp. 195-213.TechnologyDiamond synthetics
DS200512-0421
2005
Yan, C-S.Hemley, R.J.,Chun Chen, Y., Yan, C-S.Growing diamond crystals by chemical vapor deposition.Elements, Vol. 1, 2, March pp. 105-108.CVD, HP
DS2002-1792
2002
Yan, D-P.Zhou, M-F., Yan, D-P., Kennedy, A.K., Li, Y., Ding, J.SHRIMP U Pb zircon geochronology and geochemical evidence for Neoproterozoic arc magmatism along marginEarth and Planetary Science Letters, Vol.196, 1-2, Feb.28, pp.51-67.China, SouthYangtze Block - western margin, Geochemistry, uranium, lead isotopes
DS200812-1289
2008
Yan, J.Yan, J., Chen, J-F., Xu, X-S.Geochemistry of Cretaceous mafic rocks from the Lower Yangtze region, eastern China: characteristics and evolution of the lithospheric mantle.Journal of Asian Earth Sciences, Vol. 33, 3-4, July 15, pp. 177-193.ChinaGeochemistry
DS202004-0547
2020
Yan, J.Yan, J., Ballmer, M.D., Tackley, P.J.The evolution and distribution of recycled oceanic crust in the Earth's mantle: insight from geodynamic models.Earth and Planetary Science Letters, Vol. 537, 116171 12p. PdfMantlegeothermometry

Abstract: A better understanding of the Earth's compositional structure is needed to place the geochemical record of surface rocks into the context of Earth accretion and evolution. Cosmochemical constraints imply that lower-mantle rocks may be enriched in silica relative to upper-mantle pyrolite, whereas geophysical observations support whole-mantle convection and mixing. To resolve this discrepancy, it has been suggested that subducted mid-ocean ridge basalt (MORB) segregates from subducted harzburgite to accumulate in the mantle transition zone (MTZ) and/or the lower mantle. However, the key parameters that control basalt segregation and accumulation remain poorly constrained. Here, we use global-scale 2D thermochemical convection models to investigate the influence of mantle-viscosity profile, planetary-tectonic style and bulk composition on the evolution and distribution of mantle heterogeneity. Our models robustly predict that, for all cases with Earth-like tectonics, a basalt-enriched reservoir is formed in the MTZ, and a harzburgite-enriched reservoir is sustained at 660~800 km depth, despite ongoing whole-mantle circulation. The enhancement of basalt and harzburgite in and beneath the MTZ, respectively, are laterally variable, ranging from ~30% to 50% basalt fraction, and from ~40% to 80% harzburgite enrichment relative to pyrolite. Models also predict an accumulation of basalt near the core mantle boundary (CMB) as thermochemical piles, as well as moderate enhancement of most of the lower mantle by basalt. While the accumulation of basalt in the MTZ does not strongly depend on the mantle-viscosity profile (explained by a balance between basalt delivery by plumes and removal by slabs at the given MTZ capacity), that of the lowermost mantle does: lower-mantle viscosity directly controls the efficiency of basalt segregation (and entrainment) near the CMB; upper-mantle viscosity has an indirect effect through controlling slab thickness. Finally, the composition of the bulk-silicate Earth may be shifted relative to that of upper-mantle pyrolite, if indeed significant reservoirs of basalt exist in the MTZ and lower mantle.
DS202005-0772
2020
Yan, J.Yan, J., Ballmer, M.D., Tackley, P.J.The evolutiom and distribution of recycled oceanic crust in the Earth's mantle: insight from geodynamic models. ( harzburgite)Earth and Planetary Science Letters, Vol. 537, 116171, 12p. PdfMantlegeodynamics

Abstract: A better understanding of the Earth's compositional structure is needed to place the geochemical record of surface rocks into the context of Earth accretion and evolution. Cosmochemical constraints imply that lower-mantle rocks may be enriched in silica relative to upper-mantle pyrolite, whereas geophysical observations support whole-mantle convection and mixing. To resolve this discrepancy, it has been suggested that subducted mid-ocean ridge basalt (MORB) segregates from subducted harzburgite to accumulate in the mantle transition zone (MTZ) and/or the lower mantle. However, the key parameters that control basalt segregation and accumulation remain poorly constrained. Here, we use global-scale 2D thermochemical convection models to investigate the influence of mantle-viscosity profile, planetary-tectonic style and bulk composition on the evolution and distribution of mantle heterogeneity. Our models robustly predict that, for all cases with Earth-like tectonics, a basalt-enriched reservoir is formed in the MTZ, and a harzburgite-enriched reservoir is sustained at 660~800 km depth, despite ongoing whole-mantle circulation. The enhancement of basalt and harzburgite in and beneath the MTZ, respectively, are laterally variable, ranging from ~30% to 50% basalt fraction, and from ~40% to 80% harzburgite enrichment relative to pyrolite. Models also predict an accumulation of basalt near the core mantle boundary (CMB) as thermochemical piles, as well as moderate enhancement of most of the lower mantle by basalt. While the accumulation of basalt in the MTZ does not strongly depend on the mantle-viscosity profile (explained by a balance between basalt delivery by plumes and removal by slabs at the given MTZ capacity), that of the lowermost mantle does: lower-mantle viscosity directly controls the efficiency of basalt segregation (and entrainment) near the CMB; upper-mantle viscosity has an indirect effect through controlling slab thickness. Finally, the composition of the bulk-silicate Earth may be shifted relative to that of upper-mantle pyrolite, if indeed significant reservoirs of basalt exist in the MTZ and lower mantle.
DS202007-1131
2020
Yan, J.Chisenga, C., Van der Meijde, M., Yan, J., Fadel. I., Atekwana, E.A., Steffen, R., Ramotoroko, C.Gravity derived crustal thickness model of Botswana: its implication for the Mw 6.5 April 3, 2017, Botswana earthquake. Tectonophysics, Vol. 787, 228479 12p. PdfAfrica, Botswanageophysics - gravity

Abstract: Botswana experienced a Mw 6.5 earthquake on 3rd April 2017, the second largest earthquake event in Botswana's recorded history. This earthquake occurred within the Limpopo-Shashe Belt, ~350 km southeast of the seismically active Okavango Rift Zone. The region has no historical record of large magnitude earthquakes or active faults. The occurrence of this earthquake was unexpected and underscores our limited understanding of the crustal configuration of Botswana and highlight that neotectonic activity is not only confined to the Okavango Rift Zone. To address this knowledge gap, we applied a regularized inversion algorithm to the Bouguer gravity data to construct a high-resolution crustal thickness map of Botswana. The produced crustal thickness map shows a thinner crust (35-40 km) underlying the Okavango Rift Zone and sedimentary basins, whereas thicker crust (41-46 km) underlies the cratonic regions and orogenic belts. Our results also show localized zone of relatively thinner crust (~40 km), one of which is located along the edge of the Kaapvaal Craton within the MW 6.5 Botswana earthquake region. Based on our result, we propose a mechanism of the Botswana Earthquake that integrates crustal thickness information with elevated heat flow as the result of the thermal fluid from East African Rift System, and extensional forces predicted by the local stress regime. The epicentral region is therefore suggested to be a possible area of tectonic reactivation, which is caused by multiple factors that could lead to future intraplate earthquakes in this region.
DS2001-1277
2001
Yan, L.Yan, L., Lines, L.R.Seismic imaging and velocity analysis for an Alberta Foothills seismic survey.Geophysics, Vol. 66, No. 3, pp. 721-32.AlbertaGeophysics - seismic
DS201908-1826
2019
Yan, L-L.Yan, L-L., Zhang, K-J.Is exhumation of UHP terranes limited to low latitudes? ( coesite and diamond)Journal of Geodynamics, Vol. 130, pp. 41-56.GlobalUHP

Abstract: How the ultrahigh-pressure (UHP) terranes are exhumed to shallow levels but preserving intact relics of the UHP phase assemblages is among the most interesting but challenging topics in geosciences. We investigate all the paleolatitudes where the UHP terranes were exhumed. Our results show that all the UHP terranes in continental collision zones or oceanic accretionary wedges were exhumed within low latitudes (0°-30°), and the average paleolatitude for exhumations of the investigated 43 UHP terranes is ˜5.1° N. In contrast, those UHP xenoliths in mantle-derived igneous rocks could be brought to surface at higher paleolatitudes. Furthermore, the pattern of frequency for the UHP terranes exhumed at convergent boundaries is consistent with that of interglacial stages throughout the Earth history, indicating that the UHP exhumation is controlled by the climate and thus suggesting that the exhumed UHP terranes may be useful paleoclimate indicators.
DS200412-2166
2004
Yan, Q.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
DS201412-1000
2014
Yan, R.Yang, J-J., Fan, Z.F., Yu, C., Yan, R.Coseismic formation of eclogite facies cataclastic dykes at Yangkou in the Chinese Sulu UHP metamorphic belt.Journal of Metamorphic Geology, Vol. 32, 9, pp. 937-960.ChinaUHP
DS202003-0365
2019
Yan, S.Tang, S., Liu, H., Yan, S., Xu, X., Wu, W., Fan, J., Liu, J., Hu, C., Tu, L.A high sensitivity MEMS gravimeter with a large dynamic range. ( not specific to diamonds)Nature.com Microsystems & Nanoengineering, Vol. 5, doi:org/10.1038/ s41378-019-0089-7Globalgeophysics - gravity

Abstract: Precise measurement of variations in the local gravitational acceleration is valuable for natural hazard forecasting, prospecting, and geophysical studies. Common issues of the present gravimetry technologies include their high cost, high mass, and large volume, which can potentially be solved by micro-electromechanical-system (MEMS) technology. However, the reported MEMS gravimeter does not have a high sensitivity and a large dynamic range comparable with those of the present commercial gravimeters, lowering its practicability and ruling out worldwide deployment. In this paper, we introduce a more practical MEMS gravimeter that has a higher sensitivity of 8?µGal/vHz and a larger dynamic range of 8000 mGal by using an advanced suspension design and a customized optical displacement transducer. The proposed MEMS gravimeter has performed the co-site earth tides measurement with a commercial superconducting gravimeter GWR iGrav with the results showing a correlation coefficient of 0.91.
DS2002-1753
2002
Yan, W.Xu, Y.G., Sun, M., Yan, W., Liu, Y., Huang, X.L., Chen, X.M.Xenolith evidence for polybaric melting and stratification of the upper mantle beneath South China.Journal of Asian Earth Sciences, Vol. 20,8, pp. 937-54.ChinaMelt - xenoliths
DS2003-1369
2003
Yan, Y.Teng, J., Zeng, R., Yan, Y.Depth distribution of Moho and tectonic framework in eastern Asian continent and itsScience in China Series d Earth Sciences, Vol. 46, 5, pp. 428-46.Asia, ChinaTectonics
DS200412-1978
2003
Yan, Y.Teng, J., Zeng, R., Yan, Y.Depth distribution of Moho and tectonic framework in eastern Asian continent and its adjacent ocean areas.Science China Earth Sciences, Vol. 46, 5, pp. 428-46.Asia, ChinaTectonics
DS200412-2166
2004
Yan, Z.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
DS1988-0779
1988
Yan BenjinZhang Wenkuan, Yan BenjinOre prospecting criteria and discriminant model for kimberlite typediamonds.*CHIMineral Deposits, *CHI, Vol. 7, No. 3, pp. 77-86. also noted as pp. 71-78ChinaKimberlite, Diamond genesis
DS1985-0749
1985
Yan binggangYan binggang, LIANG RIXUAN, Yang fengying, FANG QINGSONG.Some characters of diamond and diamond bearing ultramafic rocks in Xizang(Tibet).*CHI27th. International Geological Congress Held China**chi, pp. 341-350ChinaUltramafics, Diamond Genesis
DS1982-0648
1982
Yan binggang, SUN DESHO.Yan binggang, SUN DESHO.The Character of Diamonds in Ultrabasic Rocks in Xizang (tibet).Bulletin. Institute GEOL. (CHINESE ACAD. GEOL. SCI.), No. 5, P. 64.China, TibetDiamond Morphology
DS1991-0443
1991
Yan ChenEnkin, R.J., Yan Chen, Courtillot, V., Besse, J., Lisheng Xing, ZhenhaiA Cretaceous pole from South Chin a and the Mesozoic hairpin turn of the Eurasian apparent Polar wander pathJournal of Geophysical Research, Vol. 96, No. B3, March 10, pp. 4007-4027ChinaPaleomagnetism
DS1993-1789
1993
Yan ChenYan Chen, Courtillot, V., Cogne, J-P., Besse, J., Yang, Z., Enkin, R.The configuration of Asia prior to the collision of India: Cretaceous paleomagnetic constraints.Journal of Geophysical Research, Vol. 98, No. B 12, December 10, pp. 21, 927-21, 941.GlobalPaleomagnetics
DS1993-1089
1993
Yan GuohanMu Baolei, Yan GuohanGeochemical features of Triassic alkaline and subalkaline igneous complexes in the Yan-Liao area.Acta Geologica Sinica, Vol. 5, No. 4, pp. 339-356.ChinaAlkaline rocks, Geochemistry
DS2000-1037
2000
Yan LiuYan Liu, Zhong, D., Jiangqing Ji.Carbonatites in the eastern Himalayan syntaxis: a direct evidence for mantle magma upwelling Neogene ...Igc 30th. Brasil, Aug. abstract only 1p.India, HimalayasCarbonatite
DS201712-2701
2017
Yan Wang, C.Liu, Y-L., Ling, M-X., Williams, I.S., Yang, X-Y., Yan Wang, C., Sun, W.The formation of the giant Bayan Obo REE-Nb-Fe deposit, north China, Mesoproterozoic carbonatite and overprinted Palaeozoic dolomitization.Ore Geology Reviews, in press available, 47p.Chinadeposit - Bayan Obo

Abstract: The Bayan Obo ore deposit in Inner Mongolia, North China, the largest-known rare earth element (REE) deposit in the world, is closely associated with carbonatite dykes. Scarce zircon grains, with a wide range of ages and diverse origins, have been extracted from the Wu dyke, a REE-enriched calcitic carbonatite dyke 2?km from the East Ore Body of the Bayan Obo deposit. Three zircon populations were identified based on ages and trace element compositions: 1) Captured zircons with Paleoproterozoic and Archean ages. These zircons have REE patterns and moderate Th/U ratios similar to zircon with silicate inclusions from basement igneous rocks, which have been recognized as contaminants from wall rocks. 2) Carbonatite magmatic zircons with Mesoproterozoic ages. These zircons have high to extremely high Th/U ratios (13-1600), a characteristic signature of the Bayan Obo deposit. Two zircon grains yielded concordant 206Pb/238U ages (1.27?±?0.11?Ga?~?1.42?±?0.18?Ga) and 208Pb/232Th age (1.26?±?0.20?Ga) with calcite inclusions, indicating that the Wu dyke was emplaced at ca. 1.34?Ga, which coincides with a worldwide generation of Mesoproterozoic kimberlites, lamprophyres, carbonatites, and anorogenic magmatism. 3) Hydrothermal zircons with Caledonian and Triassic ages. The Caledonian zircon has 206Pb/238U age of 381?±?4?Ma and 208Pb/232Th age of 367?±?14?Ma with dolomite inclusion. These evidences are consistent with multiple stages of mineralization, Mesoproterozoic calcite carbonatite magmatism interacted by protracted fluxing of subduction-released Caledonian fluids during the closure of the Palaeo-Asian Ocean, coupled with interaction with the mantle wedge and metasomatism of overlying sedimentary carbonate.
DS201812-2844
2018
Yan Wang, C.Ma, Q., Xu, Y-G., Deng, Y,m Zhengm J-P., Sur, M., Griffin, W.L., Xia, B., Yan Wang, C.Similar crust beneath disrupted and intact cratons: arguments against lower crust delamination as a decratonization trigger. North China cratonTectonophysics, in press available 31p.Chinacraton

Abstract: The continental lithosphere is not forever; some cratons have lost their original roots during the course of their evolution. Yet, it is not clear whether gravitational instability of dense lower crust is the primary driver of decratonization. This is addressed here with emphasis being placed on the North China Craton (NCC), because it represents one of the best examples of craton-root disruption in the world, and a place where models can be tested. If lower-crustal delamination was the trigger for decratonization, we would expect a clear contrast in crustal structure and composition between disturbed (rootless) and intact cratons. However, the eastern (disturbed) and western (intact) parts of the NCC show virtually identical physical structure and composition (a thin mafic lower crust and a predominantly intermediate composition overall) although the crust in the disturbed part is thinner than in the intact craton. This suggests that delamination of the lower crust was not a viable mechanism of craton-root disruption in the NCC case. Indeed, the crust beneath the NCC largely resembles those of stable Archean cratons worldwide. Therefore the delamination, if it occurred, may have taken place much earlier (Archean) than previously thought, rather than in the Mesozoic. Delamination may have been a common phenomenon in the early evolution of cratons, probably due to relatively higher mantle temperatures in the Archean Eon.
DS201412-0186
2014
Yan Wong, S.D'Haenens-Johansson, U.F.S., Soe Moe, K., Johnson, P., Yan Wong, S., Lu, R., Wang, W.Near-colorless HPHT synthetic diamonds from AOTC group.Gems & Gemology, Vol. 50, 1, Spring, pp. 30-45.TechnologySynthetic diamonds
DS1990-1606
1990
Yan YaoyangYan Yaoyang, Zhang YijunThe lower Proterozoic metamorphosed impure carbonatites southernJilin.*CHIJilin Geology, *CHI, Vol. 9, No. 4, pp. 34-39ChinaCarbonatite, Petrology
DS200412-2167
2004
Yanagawa, T.K.Yanagawa, T.K., Nakada, M., Yuen, D.A.A simplified mantle convection model for thermal conductivity stratification.Physics of the Earth and Planetary Interiors, Vol. 146, 1-2, pp. 163-177.MantleGeothermometry
DS201810-2359
2018
Yanagi, R.Nakagawa, T., Iwamori, H., Yanagi, R., Nako, A.On the evolutiom of the water ocean in the plate mantle system.Progress in Earth and Planetary Science, Vol. 5, pp. 51- 16p.Mantlewater

Abstract: Here, we investigate a possible scenario of surface seawater evolution in the numerical simulations of surface plate motion driven by mantle dynamics, including thermo-chemical convection and water migration, from the early to present-day Earth to constrain the total amount of water in the planetary system. To assess the validity of two hypotheses of the total amount of water inferred from early planetary formation processes and mineral physics, we examine the model sensitivity to the total water in the planetary system (both surface and deep interior) up to 15 ocean masses. To explain the current size of the reservoir of surface seawater, the predictions based on the numerical simulations of hydrous mantle convection suggest that the total amount of water should range from 9 to 12 ocean masses. Incorporating the dense hydrous magnesium silicate (DHMS) with a recently discovered hydrous mineral at lower mantle pressures (phase H) indicates that the physical mechanism of the mantle water cycle would not be significantly influenced, but the water storage region would be expanded in addition to the mantle transition zone. The DHMS solubility field may have a limited impact on the partitioning of water in the Earth’s deep mantle.
DS1994-1960
1994
Yanagi, T.Yanagi, T., Yamashita, K.Genesis of continental crust under arc conditionsLithos, Vol. 33, pp. 209-233MantleVolcanics, Subduction - arcs
DS1996-1575
1996
Yanamoto, J.K.Yanamoto, J.K.Ore reserve estimation.. a new method of block calculation using the inverse of weighted distanceEngineering and Mining Journal, Vol. 197, No. 9, Sept. p. 69-70, 72GlobalOre reserves, geostatistics, Kriging
DS2002-0288
2002
Yanamoto, T.Chigai, T., Yanamoto, T., Kozasa, T.Heterogeneous condensation of presolar titanium carbide core graphite mantle spherules.Meteoritics and Planetary Science, Vol. 37, 12, p. 1937-52.MantleGraphite
DS1992-1714
1992
Yanbin WangYanbin Wang, Guyot, F., Liebermann, R.C.Electron microcopy of (magnesium, iron) SiO3 perovskite: evidence for structural phase transitions and implications for the lower mantleJournal of Geophysical Research, Vol. 97, No. B9, August 10, pp. 12, 327-12, 347MantlePerovksite
DS1999-0698
1999
Yanev, Y.Sparks, R.S.J., Tait, S.R., Yanev, Y.Dense welding caused by volatile resorptionJournal of Geological Society of London, Vol. 156, No. 2, Mar. pp. 217-26.GlobalMagmatism - volconology
DS2002-1759
2002
Yanez, G.Yanez, G., Cembrano, J., Pardo, M., Ranero, C., SellesThe Challinger Juan Fernadex Maipo major tectonic transition of the Nazca Andean subduction system 33-34Journal of South American Earth Sciences, Vol.15,1,Apr.pp.23-38.Chile, AndesSubduction, Geodynamic evidence and implications
DS1995-0431
1995
Yanez, G.P.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
DS1990-1635
1990
YangZhou Xiuzhong, Huang Yunhaui, Qin Shuying, Deng Chujun, Gao Yan, YangStudies on the type and the typomorphic characteristics of the garnets From kimberlites and the relationship between the garnets and diamondInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 1, extended abstract p. 141-142ChinaMineralogy -garnets, Diamond morphology
DS1993-1790
1993
YangYang, Jianjun, Godard, G., Kienast, J-R., Yongzheng Lu, JinxiongUltrahigh pressure ( 60 Kbar) magnesite-bearing garnet peridotites from northeastern Jiangsu, China.Journal of Geology, Vol. 101, No. 5, September pp. 541-554.ChinaEclogites, Shandong Province
DS2002-0957
2002
YangLiu, F., Xu, Z., Liu, J.G., Katayama, Masago, Maruyama, YangUltra high pressure mineral inclusions in zircons from gneissic core samples of the Chinese continental drilling site in eastern China.European Journal of Mineralogy, No. 3, pp. 499-512.China, easternUHP, Mineral inclusions
DS200612-1560
2006
YangXu, Z., Wang, Q., Ji, S., Chen, J., Zeng, Yang, Chen, Liang, WenkPetrofabrics and seismic properties of garnet peridotite from the UHP Sulu terrane: implications for olivine deformation mechanism in subducting slab.Tectonophysics, Vol. 421, 1-2, pp. 111-127.MantleSubduction - cold, dry continental slab
DS200812-1172
2008
YangTian, S., Hou, Ding, Yang, Yang, Yuan, Xie, Liu, Li.Ages of carbonatite and syenite from the Mianning Dechang REE belt in eastern Indo-Asian collision zone, SW Chin a and their geological significance.Goldschmidt Conference 2008, Abstract p.A947.ChinaCarbonatite
DS200812-1172
2008
YangTian, S., Hou, Ding, Yang, Yang, Yuan, Xie, Liu, Li.Ages of carbonatite and syenite from the Mianning Dechang REE belt in eastern Indo-Asian collision zone, SW Chin a and their geological significance.Goldschmidt Conference 2008, Abstract p.A947.ChinaCarbonatite
DS200812-1292
2008
YangYang, J-H, Wu, F-Y., Wilde, S.A., Belousova, E., Griffin, W.L.Mesozoic decratonization of the North Chin a block.Geology, Vol. 36, 6, June pp. 467-470.ChinaCraton
DS201112-0567
2011
YangLan, T-G., Fan, H-R., Santosh, M., Hu, F-F., Yang, Y-H, Liu, Y.Geochemistry and Sr Nd Pb Hf isotopes of the Mesozoic Dadian alkaline intrusive complex in the Sulu orogenic belt, eastern China: implications for crust mantle interaction.Chemical Geology, Vol. 285, 1-4, pp. 97-114.ChinaAlkalic
DS201112-1133
2011
YangYang, K-F, Fan, H-R., Santosh, M., Hu, F-F., Wang, K-Y.Mesoproterozoic carbonatitic magmatism in the Bayan Obo deposit, Inner Mongolia, North China: constraints for the mechanism of super accumulation of rare earth elements.Ore Geology Reviews, in press available 10p.ChinaCarbonatite, REE
DS201510-1789
2015
YangMoe, K.S., Yang, J-S, Johnson, P., Xu, X., Wang, W.Microdiamonds in chromitite and peridotite. Type 1aB and 1bGSA Annual Meeting, Paper 300-5, 1p. Abstract only BoothRussiaSpectroscopy
DS201511-1827
2015
YangCai, Y-C., Fan, H-R., Santsh, M., Hu, F-F., Yang, K-F, Hu, Z.Subduction related metasomatism of the lithospheric mantle beneath the southeastern North Chin a Craton: evidence from mafic to intermediate dykes in the northern Sulu orogen.Tectonophysics, Vol. 659, pp. 137-151.ChinaSulu orogen - dykes

Abstract: The widespread mafic to intermediate dykes in the northern Sulu orogen provide important constrains on mantle source characteristics and geodynamic setting. Here we present LA-ICPMS zircon U-Pb ages which indicate that the dykes were emplaced during Early Cretaceous (~ 113-108 Ma). The rocks show SiO2 in the range of 46.2 to 59.5 wt.% and alkalic and shoshonitic affinity with high concentrations of MgO (up to 7.6 wt.%), Cr (up to 422 ppm) and Ni (up to 307 ppm). They are enriched in light rare earth elements LREE (La, Ce, Pr, Nd, Sm and Eu) and large ion lithophile elements (LILE, Rb, Sr, Ba, U and Th) and show strong depletion in high field strength elements (HFSE, Nb, Ta, Ti and P). The dykes possess uniformly high (87Sr/86Sr)i (0.70824-0.70983), low eNd(t) (- 14.0 to - 17.4) and (206Pb/204Pb)i (16.66-17.02) and negative eHf(t) (- 23.5 to - 13.7). Our results suggest that the source magma did not undergo any significant crustal contamination during ascent. The systematic variation trends between MgO and major and trace elements suggest fractionation of olivine and clinopyroxene. The highly enriched mantle source for these rocks might have involved melts derived from the subducted lower crust of Yangtze Craton that metasomatized the ancient lithospheric mantle of the North China Craton.
DS202002-0203
2020
YangLiu, S., Fan, H-R., Groves, D.I., Yang, K-F, Yang, Z-F., Wang, Q-W.Multiphase carbonatite related magmatic and metasomatic processes in the genesis of the ore-hosting dolomite in the giant Bayan Obo REE-Nb-Fe deposit.Lithos, in press available, 96p. PdfChinacarbonatite

Abstract: The origin of dolomite that hosts the Bayan Obo REE-Nb-Fe deposit (57.4 % REE2O3, 2.16 % Nb2O5, and >1500 % iron oxides) has been controversial for decades, but it is integral to understanding of the genesis of this giant deposit. In this study, based on the textures and in situ major and trace element composition of its carbonates, the dolomite was proved to be initially generated from magnesio-ferro-carbonatite melts. It subsequently experienced magmatic-hydrothermal alteration and recrystallization in a low strain environment, caused by calcio-carbonatitic fluids, with formation of finer-grained dolomite, interstitial calcite and increasing amounts of associated fluorocarbonates. Available stable isotope analyses indicate that the recrystallized ore-hosting dolomite has higher d13C and d18O ratios compared to its igneous coarse-grained precursor. Rayleigh fractionation during the recrystallization process, rather than crustal contamination, played a major role in the highly-variable stable isotope composition of carbonates in the dolomite. Low-T alteration increased variability with apparently random increases in d18O within carbonates. The REE, Ba and Sr were added simultaneously with the elevated (La/Yb)cn from magnesio-ferro-carbonatite melts to calcio-carbonatitic fluids, and to carbonatite-derived aqueous fluids, through which extensive fluorine metasomatism and alkali alteration overlapped the recrystallization of the ore-hosting dolomite. Therefore, the multi-stage REE mineralization at Bayan Obo is closely related to metasomatism by calcio-carbonatitic fluids of previously-emplaced intrusive magnesio-ferro-carbonatite bodies during late evolution of the Bayan Obo carbonatite complex. Then, the ore-hosting dolomitic carbonatite was subjected to compressive tectonics during a Paleozoic subduction event, and suffered intense, largely brittle, deformation, which partially obscured the earlier recrystallization process. The complex, multi-stage evolution of the ore-hosting dolomite is responsible for the uniqueness, high grade and giant size of the Bayan Obo deposit, the world's largest single REE resource with million tonnes of REE oxides.
DS201312-0989
2013
Yang, A.Q.Yang, A.Q., Zeng, Z-j., Zheng, X-q., Hu, Y-l.Emplacement age and Sr-Nd isotopic compositions of the AfrikAnd a alkaline ultramafic complex, Kola Peninsula, Russia.Spectroscopy and Spectral Analysis, Vol. 33, 9, pp. 2374-2378.ChinaDeposit - Mengyin
DS201312-0738
2014
Yang, B.B.Refayee, H.A., Yang, B.B., Liu, K.H., Gao, S.S.Mantle flow and lithosphere asthenosphere coupling beneath the southwestern edge of the North American craton: constraints from shear wave splitting measurements.Earth and Planetary Science Letters, Vol. 402, pp. 209-220.CanadaAnisotropy
DS2000-0427
2000
Yang, C.Hutcheon, I., Cody, J., Yang, C.Fluid flow in the Western Canada Sedimentary Basin - a biased perspective based on geochemistry.Kyser: Fluids and Basin Evolution, Sc 28, pp. 197-210.Alberta, Western Canada Sedimentary BasinBasin - geochemistry
DS202009-1676
2020
Yang, C.Zheng, H., Chen, H., Wu, C., Jiang, H., Gao, C., Kang, Q., Yang, C., Wang, D., Lai, C-K.Genesis of the supergiant Huayangchuan carbonatite-hosted uranium polymetallic deposit in the Qinling orogen, central China.Gondwana Research, Vol. 86, pp. 250-265.ChinaREE

Abstract: The newly-discovered supergiant Huayangchuan uranium (U)-polymetallic deposit is situated in the Qinling Orogen, Central China. The deposit contains economic endowments of U, Nb, Pb, Se, Sr, Ba and REEs, some of which (e.g., U, Se, and Sr) reaching super-large scale. Pyrochlore, allanite, monazite, barite-celestite and galena are the major ore minerals at Huayangchuan. Uranium is mainly hosted in the primary mineral of pyrochlore, and the mineralization is mainly hosted in or associated with carbonatite dikes. According to the mineral assemblages and crosscutting relationships, the alteration/mineralization at Huayangchuan comprises four stages, i.e., pegmatite REE mineralization (I), main mineralization (II), skarn mineralization (III) and post-ore alteration (IV). Coarse-grained euhedral allanite is the main Stage I REE mineral, and the pegmatite-hosted REE mineralization (ca. 1.8 Ga) occurs mostly in the shallow-level of northwestern Huayangchuan, corresponding to the Paleoproterozoic Xiong'er Group volcanic rocks (1.80-1.75 Ga) in the southern margin of North China Block. Carbonatite-hosted Stage II mineralization contributes to the majority of U-Nb-REE-Ba-Sr resources, and is controlled by the Huayangchuan Fault. Stage II mineralization can be further divided into the sulfate mineralization (barite-celestite) (II-A), alkali-rich U mineralization (aegirine-augite + pyrochlore + uraninite + uranothorite) (II-B) and REE (allanite + monazite + chevkinite)-U (pyrochlore + uraninite) mineralization (II-C) substages. Stage II mineralization may have occurred during the Late Triassic Mianlue Ocean closure. Skarn mineralization contributed to the majority of Pb and minor U-REE (uraninite-allanite) resources at Huayangchuan, and is spatially associated with the Late Cretaceous-Early Jurassic (Yanshanian) Huashan and Laoniushan granites. We suggested that hydrothermal fluids derived from the Laoniushan and Huashan granites may have reacted with the Triassic carbonatites, and formed the Huayangchuan Pb skarn mineralization. The mantle-derived Triassic carbonatites may have been fertilized by the U-rich subducting oceanic sediments, and were further enriched through reacting with the Proterozoic U-REE-rich pegmatite wallrocks at Huayangchuan. Ore-forming elements were likely transported in metal complexes (F-, and ), and deposited with the dilution of the complex concentration. This may have formed the distinct vertical mineralization zoning, i.e., sodic fenite-related alkali-U mineralization at depths and potassic fenite-related REE-U mineralization at shallow level.
DS202012-2242
2020
Yang, C.Qin, L., Yang, C.Magnetotelluric soundings on a stratified Earth with two transitional layers.Pure and Applied Physics, Vol. 177, pp. 5263-5274.Mantlegeophysics - magnetics

Abstract: Theoretical magnetotelluric (MT) soundings are investigated for a stratified (five-layered) Earth model consisting of two transitional layers with conductivity varying linearly with depth, and three homogeneous layers with constant conductivity. The analytical expressions for the tangential electric and magnetic fields as well as the surface impedance are derived in terms of Airy functions. The effect of the thicknesses of the two transitional layers and the interlayer between them on the MT responses (apparent resistivity and impedance phase) is examined in detail.
DS202012-2258
2020
Yang, C.Zheng, H., Chen, H., Wu, C., Jiang, H., Gao, C., Kang, Q., Yang, C., Wang, D., Lai, C-k.Genesis of the supergiant Huayanchuan carbonatite-hosted uranium-plymetallic deposit in the Qinling Orogen, central China.Gondwana Research, Vol. 86, pp. 250-265. pdfChinadeposit - Huayangchuan

Abstract: The newly-discovered supergiant Huayangchuan uranium (U)-polymetallic deposit is situated in the Qinling Orogen, Central China. The deposit contains economic endowments of U, Nb, Pb, Se, Sr, Ba and REEs, some of which (e.g., U, Se, and Sr) reaching super-large scale. Pyrochlore, allanite, monazite, barite-celestite and galena are the major ore minerals at Huayangchuan. Uranium is mainly hosted in the primary mineral of pyrochlore, and the mineralization is mainly hosted in or associated with carbonatite dikes. According to the mineral assemblages and crosscutting relationships, the alteration/mineralization at Huayangchuan comprises four stages, i.e., pegmatite REE mineralization (I), main mineralization (II), skarn mineralization (III) and post-ore alteration (IV). Coarse-grained euhedral allanite is the main Stage I REE mineral, and the pegmatite-hosted REE mineralization (ca. 1.8 Ga) occurs mostly in the shallow-level of northwestern Huayangchuan, corresponding to the Paleoproterozoic Xiong'er Group volcanic rocks (1.80-1.75 Ga) in the southern margin of North China Block. Carbonatite-hosted Stage II mineralization contributes to the majority of U-Nb-REE-Ba-Sr resources, and is controlled by the Huayangchuan Fault. Stage II mineralization can be further divided into the sulfate mineralization (barite-celestite) (II-A), alkali-rich U mineralization (aegirine-augite + pyrochlore + uraninite + uranothorite) (II-B) and REE (allanite + monazite + chevkinite)-U (pyrochlore + uraninite) mineralization (II-C) substages. Stage II mineralization may have occurred during the Late Triassic Mianlue Ocean closure. Skarn mineralization contributed to the majority of Pb and minor U-REE (uraninite-allanite) resources at Huayangchuan, and is spatially associated with the Late Cretaceous-Early Jurassic (Yanshanian) Huashan and Laoniushan granites. We suggested that hydrothermal fluids derived from the Laoniushan and Huashan granites may have reacted with the Triassic carbonatites, and formed the Huayangchuan Pb skarn mineralization. The mantle-derived Triassic carbonatites may have been fertilized by the U-rich subducting oceanic sediments, and were further enriched through reacting with the Proterozoic U-REE-rich pegmatite wallrocks at Huayangchuan. Ore-forming elements were likely transported in metal complexes (F-, and ), and deposited with the dilution of the complex concentration. This may have formed the distinct vertical mineralization zoning, i.e., sodic fenite-related alkali-U mineralization at depths and potassic fenite-related REE-U mineralization at shallow level.
DS201911-2564
2019
Yang, C-X.Snatish, M., Tsunogae, T., Yang, C-X., Han, Y-S., Hari, K.R., Prasanth, M., Uthup, S.The Bastar craton, central India: a window to Archean-paleoproterozoic crustal evolution.Gondwana Research, in press available 69p. PdfIndiacraton

Abstract: The Bastar craton in central India, surrounded by cratonic blocks and Paleoproterozoic to Neoproterozoic orogenic belts, is a window to investigate the Archean-Paleoproterozoic crustal evolution and tectonic processes. Here we propose a new tectonic classification of the craton into the Western Bastar Craton (WBC), Eastern Bastar Craton (EBC), and the intervening Central Bastar Orogen (CBO). We present petrologic, geochemical and zircon U-Pb, REE and Lu-Hf data from a suite of rocks from the CBO and along the eastern margin of the WBC Including: (1) volcanic successions comprising meta-andesite and fine-grained amphibolite, representing arc-related volcanics along a convergent margin; (2) ferruginous sandstone, in association with rhyolite, representing a volcano-sedimentary succession, deposited in an active trench; and (3) metamorphosed mafic-ultramafic suite including gabbro, pyroxenite and dunite invaded by trondhjemite representing the section of sub-arc mantle and arc root adjacent to a long-lasting subduction system. Petrologic studies indicate that the mafic-ultramafic suite crystallized from an island arc tholeiitic parental magma in a suprasubduction zone environment. The chondrite-normalized and primitive mantle normalized diagrams of the mafic and ultramafic rocks suggest derivation from MORB magma. The mixed characters from N-MORB to E-MORB of the studied samples are consistent with subduction modification of a MORB related magma, involving partial melting of the metasomatized mantle wedge. Our zircon U-Pb age data suggest that the cratonic nuclei was constructed as early as Paleoarchean. We present evidence for active subduction and arc magmatism through Mesoarchean to Neoarchean and early Paleoproterozoic, with the trench remaining open until at least 2.3 Ga. Two major crust building events are recognized in the Bastar craton: during Mesoarchean (recycled Paleoarchean subduction-related as well as juvenile/depleted mantle components) and Neoarchean (accretion of juvenile oceanic crust, arc magmatism including granite batholiths and related porphyry mineralization). The final cratonization occurred during latest Paleoproterozoic, followed by collisional assembly of the craton and its incorporation within the Peninsular Indian mosaic during Mesoproterozoic. In the global supercontinent context, the craton preserves the history of Ur, the earliest supercontinent, followed by the Paleo-Mesoproterozoic Columbia, as well as minor thermal imprints of the Neoproterozoic Rodinia and associated Grenvillian orogeny.
DS202001-0037
2020
Yang, C-X.Santosh, M., Tsunogae, T., Yang, C-X., Han, T-S., Hari, K.R., Prasanth, M.P.M., Uthup, S.The Bastar craton, central India: a window to Archean - Paleoproterozic crustal evolution.Gondwana Research, Vol. 79, pp. 157-184.Indiacraton

Abstract: The Bastar craton in central India, surrounded by cratonic blocks and Paleoproterozoic to Neoproterozoic orogenic belts, is a window to investigate the Archean-Paleoproterozoic crustal evolution and tectonic processes. Here we propose a new tectonic classification of the craton into the Western Bastar Craton (WBC), Eastern Bastar Craton (EBC), and the intervening Central Bastar Orogen (CBO). We present petrologic, geochemical and zircon U-Pb, REE and Lu-Hf data from a suite of rocks from the CBO and along the eastern margin of the WBC Including: (1) volcanic successions comprising meta-andesite and fine-grained amphibolite, representing arc-related volcanics along a convergent margin; (2) ferruginous sandstone, in association with rhyolite, representing a volcano-sedimentary succession, deposited in an active trench; and (3) metamorphosed mafic-ultramafic suite including gabbro, pyroxenite and dunite invaded by trondhjemite representing the section of sub-arc mantle and arc root adjacent to a long-lasting subduction system. Petrologic studies indicate that the mafic-ultramafic suite crystallized from an island arc tholeiitic parental magma in a suprasubduction zone environment. The chondrite-normalized and primitive mantle normalized diagrams of the mafic and ultramafic rocks suggest derivation from MORB magma. The mixed characters from N-MORB to E-MORB of the studied samples are consistent with subduction modification of a MORB related magma, involving partial melting of the metasomatized mantle wedge. Our zircon U-Pb age data suggest that the cratonic nuclei was constructed as early as Paleoarchean. We present evidence for active subduction and arc magmatism through Mesoarchean to Neoarchean and early Paleoproterozoic, with the trench remaining open until at least 2.3?Ga. Two major crust building events are recognized in the Bastar craton: during Mesoarchean (recycled Paleoarchean subduction-related as well as juvenile/depleted mantle components) and Neoarchean (accretion of juvenile oceanic crust, arc magmatism including granite batholiths and related porphyry mineralization). The final cratonization occurred during latest Paleoproterozoic, followed by collisional assembly of the craton and its incorporation within the Peninsular Indian mosaic during Mesoproterozoic. In the global supercontinent context, the craton preserves the history of Ur, the earliest supercontinent, followed by the Paleo-Mesoproterozoic Columbia, as well as minor thermal imprints of the Neoproterozoic Rodinia and associated Grenvillian orogeny.
DS202003-0361
2020
Yang, C-X.Santosh, M., Tsunogae, T., Yang, C-X., Han, Y-S., Hari, K.R., Manu Prasanth, M.P., Uthup, S.The Bastar craton, central India: a window to Archean - Paleoproterozoic crustal evolution.Gondwana Research, Vol. 79, pp. 157-184.Indiacraton

Abstract: The Bastar craton in central India, surrounded by cratonic blocks and Paleoproterozoic to Neoproterozoic orogenic belts, is a window to investigate the Archean-Paleoproterozoic crustal evolution and tectonic processes. Here we propose a new tectonic classification of the craton into the Western Bastar Craton (WBC), Eastern Bastar Craton (EBC), and the intervening Central Bastar Orogen (CBO). We present petrologic, geochemical and zircon U-Pb, REE and Lu-Hf data from a suite of rocks from the CBO and along the eastern margin of the WBC Including: (1) volcanic successions comprising meta-andesite and fine-grained amphibolite, representing arc-related volcanics along a convergent margin; (2) ferruginous sandstone, in association with rhyolite, representing a volcano-sedimentary succession, deposited in an active trench; and (3) metamorphosed mafic-ultramafic suite including gabbro, pyroxenite and dunite invaded by trondhjemite representing the section of sub-arc mantle and arc root adjacent to a long-lasting subduction system. Petrologic studies indicate that the mafic-ultramafic suite crystallized from an island arc tholeiitic parental magma in a suprasubduction zone environment. The chondrite-normalized and primitive mantle normalized diagrams of the mafic and ultramafic rocks suggest derivation from MORB magma. The mixed characters from N-MORB to E-MORB of the studied samples are consistent with subduction modification of a MORB related magma, involving partial melting of the metasomatized mantle wedge. Our zircon U-Pb age data suggest that the cratonic nuclei was constructed as early as Paleoarchean. We present evidence for active subduction and arc magmatism through Mesoarchean to Neoarchean and early Paleoproterozoic, with the trench remaining open until at least 2.3?Ga. Two major crust building events are recognized in the Bastar craton: during Mesoarchean (recycled Paleoarchean subduction-related as well as juvenile/depleted mantle components) and Neoarchean (accretion of juvenile oceanic crust, arc magmatism including granite batholiths and related porphyry mineralization). The final cratonization occurred during latest Paleoproterozoic, followed by collisional assembly of the craton and its incorporation within the Peninsular Indian mosaic during Mesoproterozoic. In the global supercontinent context, the craton preserves the history of Ur, the earliest supercontinent, followed by the Paleo-Mesoproterozoic Columbia, as well as minor thermal imprints of the Neoproterozoic Rodinia and associated Grenvillian orogeny.
DS201412-0184
2014
Yang, D.Devriese, S.G.R., Corcoran, N., Cowan, D., Davis, K., Bild-Enkin, D., Fournier, D., Heagy, L., Kang, S., Marchant, D., McMillan, M.S., Mitchell, M., Rosenkjar, G., Yang, D., Oldenburg, D.W.Magnetic inversion of three airborne dat a sets over the Tli Kwi Cho kimberlite complex.SEG Annual Meeting Denver, pp. 1790-1794 extended abstractCanada, Northwest TerritoriesGeophysics - Tli Kwi Cho
DS201412-0250
2014
Yang, D.Fournier, D., Heagy, L., Corcoran, N., Devriese, S.G.R., Bild-Enkin, D., Davis, K., Kang, S., Marchant, D., McMillan, M.S., Mitchell, M., Rosenkjar, G., Yang, D., Oldenburg, D.W.Multi-EM systems inversion - towards a common conductivity model for Tli Kwi Cho complex.SEG Annual Meeting Denver, pp. 1795-1798. Extended abstractCanada, Northwest TerritoriesGeophysics - Tli Kwi Cho complex
DS201501-0006
2014
Yang, D.Devriese, S.G.R., Corcoran, N., Cowan, D., Davis, K., Bild-Enkin, D., Fournier, D., Heagy, L., Kang, S., Marchant, D., McMillan, M.S., Mitchell, M., Rosenkjar, G., Yang, D., Oldenburg, D.W.Magnetic inversion of three airborne dat a sets over the Tli Kwi Cho kimberlite complex.SEG Annual Meeting Denver, 5p. Extended abstractCanada, Northwest TerritoriesDeposit - Tli Kwi Cho, geophysics

Abstract: The magnetic and electromagnetic responses from airborne systems at Tli Kwi Cho, a kimberlite complex in the Northwest Territories, Canada, have received considerable attention over the last two decades but a complete understanding of the causative physical properties is not yet at hand. Our analysis is distributed among three papers. In the first, we find a 3D magnetic susceptibility model for the area; in the second, we find a 3D conductivity model; and in the third paper, we find a 3D chargeability model. Our goal is to explain all the geophysical results within a geologic framework. In this first paper, we invert three independent airborne magnetic data sets flown over the Tli Kwi Cho kimberlite complex located in the Lac de Gras kimberlite field in Northwest Territories, Canada. The complex consists of two kimberlites known as DO-27 and DO-18. An initial airborne DIGHEM survey was flown in 1992 and AeroTEM and VTEM data subsequently acquired in 2003 and 2004, respectively. In this paper, we invert each magnetic data set in three dimensions. Both kimberlites are recovered in each model, with DO-27 as a more susceptible body than DO-18. Our goal is to simultaneously invert the three data sets to generate a single susceptibility model for Tli Kwi Cho. This project is part of a larger, on-going investigation by UBC-GIF on inverting magnetic, electromagnetic, and induced polarization data from the Tli Kwi Cho area.
DS201501-0009
2014
Yang, D.Fournier, D., Heagy, L., Corcoran, N., Cowan, D., Devriese, S.G.R., Bild-Enkin, D., Davis, K., Kang, S., Marchant, D., McMillan, M.S., Mitchell, M., Rosenkjar, G., Yang, D., Oldenburg, D.W.Multi-EM systems inversion - towards a common conductivity model for Tli Kwi Cho complex.SEG Annual Meeting Denver, 5p. Extended abstractCanada, Northwest TerritoriesDeposit - Tli Kwi Cho, geophysics

Abstract: The magnetic and electromagnetic responses from airborne systems at Tli Kwi Cho, a kimberlite complex in the Northwest Territories, Canada, have received considerable attention over the last two decades but a complete understanding of the causative physical properties is not yet at hand. Our analysis is distributed among three posters. In the first we find a 3D magnetic susceptibility model for the area; in the second we find a 3D conductivity model; and in the third we find a 3D chargeability model that can explain the negative transient responses measured over the kimberlite pipes. In this second paper we focus upon the task of finding a conductivity model that is compatible with three airborne data sets flown between 1992 and 2004: one frequency-domain data set (DIGHEM) and two time-domain systems (AeroTEM and VTEM). The goal is to obtain a 3D model from which geologic questions can be answered, but even more importantly, to provide a background conductivity needed to complete the 3D IP inversion of airborne EM data. We begin by modifying our pre-existing 1D frequency and time domain inversion codes to produce models that have more lateral continuity. The results are useful in their own right but we have also found that 1D analysis is often very effective in bringing to light erroneous data, assisting in estimating noise floors, and providing some starting information for developing a background model for the 3D EM inversion. Here we show some results from our Laterally Constrained Inversion (LCI) framework. The recovered conductivity models seem to agree on the general location of the kimberlite pipes but disagree on the geometry and conductivity values at depth. The complete 3D inversions in time and frequency, needed to resolved these issues, are currently in progress.
DS201611-2103
2014
Yang, D.Devriese, S.G.R., Corcoran, N., Cowan, D., Davis, K., Bild-Enkin, D., Fournier, D., Heagy, L., Kang, S., Marchant, D., McMillan, M.S., Mitchell, M., Rosenkjar, G., Yang, D., Oldenburg, D.W.Magnetic inversion of three airborne dat a sets over the Tli Kwi Cho kimberlite complex.SEG Annual Meeting Denver, pp. 1790-1794. pdfCanada, Northwest TerritoriesDeposit - Tli Kwi Cho

Abstract: The magnetic and electromagnetic responses from airborne systems at Tli Kwi Cho, a kimberlite complex in the Northwest Territories, Canada, have received considerable attention over the last two decades but a complete understanding of the causative physical properties is not yet at hand. Our analysis is distributed among three papers. In the first, we find a 3D magnetic susceptibility model for the area; in the second, we find a 3D conductivity model; and in the third paper, we find a 3D chargeability model. Our goal is to explain all the geophysical results within a geologic framework. In this first paper, we invert three independent airborne magnetic data sets flown over the Tli Kwi Cho kimberlite complex located in the Lac de Gras kimberlite field in Northwest Territories, Canada. The complex consists of two kimberlites known as DO-27 and DO- 18. An initial airborne DIGHEM survey was flown in 1992 and AeroTEM and VTEM data subsequently acquired in 2003 and 2004, respectively. In this paper, we invert each magnetic data set in three dimensions. Both kimberlites are recovered in each model, with DO-27 as a more susceptible body than DO-18. Our goal is to simultaneously invert the three data sets to generate a single susceptibility model for Tli Kwi Cho. This project is part of a larger, on-going investigation by UBC-GIF on inverting magnetic, electromagnetic, and induced polarization data from the Tli Kwi Cho area.
DS201611-2107
2014
Yang, D.Fournier, D., Heagy, L., Corcoran, N., Cowan, D., Devriese, S.G.R., Bild-Enkin, D., Davis, K., Marchant, M., McMillan, M.S., Mitchell, M., Rosenkjar, G., Yang, D., Oldenburg, D.W.Multi-EM systems inversion - towards a common conductivity model for Tli Kwi Cho complex.SEG Annual Meeting Denver, pp. 1795-1799. pdfCanada, Northwest TerritoriesDeposit - Tli Kwi Cho

Abstract: The magnetic and electromagnetic responses from airborne systems at Tli Kwi Cho, a kimberlite complex in the Northwest Territories, Canada, have received considerable attention over the last two decades but a complete understanding of the causative physical properties is not yet at hand. Our analysis is distributed among three posters. In the first we find a 3D magnetic susceptibility model for the area; in the second we find a 3D conductivity model; and in the third we find a 3D chargeability model that can explain the negative transient responses measured over the kimberlite pipes. In this second paper we focus upon the task of finding a conductivity model that is compatible with three airborne data sets flown between 1992 and 2004: one frequency-domain data set (DIGHEM) and two time-domain systems (AeroTEM and VTEM). The goal is to obtain a 3D model from which geologic questions can be answered, but even more importantly, to provide a background conductivity needed to complete the 3D IP inversion of airborne EM data. We begin by modifying our pre-existing 1D frequency and time domain inversion codes to produce models that have more lateral continuity. The results are useful in their own right but we have also found that 1D analysis is often very effective in bringing to light erroneous data, assisting in estimating noise floors, and providing some starting information for developing a background model for the 3D EM inversion. Here we show some results from our Laterally Constrained Inversion (LCI) framework. The recovered conductivity models seem to agree on the general location of the kimberlite pipes but disagree on the geometry and conductivity values at depth. The complete 3D inversions in time and frequency, needed to resolved these issues, are currently in progress.
DS200812-1282
2008
Yang, D.B.Xu, W-L., Yang, D.B., Gao, S., Yu, Y., Pei, F.P.Mesozoic lithospheric mantle of the Central North Chin a craton: evidence from peridotite xenoliths.Goldschmidt Conference 2008, Abstract p.A1047.ChinaXenoliths
DS201112-1129
2011
Yang, D.B.Xu,L., Zhou, Q.J., Pei, F.P., Yang, D.B., Gao, S., Wang, W., Feng, H.Recycling lower continental crust in an intra continental setting: mineral chemistry and oxygen isotope insights from websterite xenoliths.Goldschmidt Conference 2011, abstract p.2197.ChinaNorth China craton
DS200812-1290
2008
Yang, F.Yang, F., Liu, B., Ni, S., Zeng, X., Dai, Z., Li, Y.Lowermost mantle shear velocity anisotropy beneath Siberia.Acta Seismologica Sinica, Vol. 21, 3, pp. 213-216.RussiaGeophysics - seismics
DS1998-1610
1998
Yang, H.Yang, H., Lyser, K., Ansdell, K.Geochemical and neodymium isotopic compositions of the metasedimentary rocks In the la Ronge DomainPrecambrian Research, Vol. 92, No. 1, Sept. pp. 37-64Saskatchewan, ManitobaTrans Hudson Orogen, Evolution, tectonics
DS200512-0562
2005
Yang, H.Konzett, J., Yang, H., Frost, D.J.Phase relations and stability of magnetoplumbite and crichtonite series phases under upper mantle P-T conditions: an experimental study to 15 GPa with LILEJournal of Petrology, Vol. 46, 4, pp. 749-781.MantleMetasomatism - lithosphere
DS200512-0563
2005
Yang, H.Konzett, J., Yang, H., Frost, D.J.Phase relations and stability of magnetoplumbite and crichtonite series phases under upper mantle P T conditions: an experimental study to 15 GPa. LILEJournal of Petrology, Vol. 46, 4, pp. 749-781.MantleMetasomatism in the lithospheric mantle
DS201801-0064
2017
Yang, H.Simon, S.J., Wei, C.T., Viladkar, S.G., Ellmies, R., Soh, Tamech, L.S., Yang, H., Vatuva, A.Metamitic U rich pyrochlore from Epembe sovitic carbonatite dyke, NW Namibia.Carbonatite-alkaline rocks and associated mineral deposits , Dec. 8-11, abstract p. 12.Africa, Namibiadeposit - Epembe

Abstract: The Epembe carbonatite dyke is located about 80 km north of Opuwo, NW Namibia. The 10 km long dyke is dominated by massive and banded sövitic carbonatite intrusions. Two distinct type of sövite have been recognized: (1) coarse-grained light grey Sövite I which is predominant in brecciated areas and (2) medium- to fine-grained Sövite II which hosts notable concentrations of pyrochlore and apatite. The contact between the carbonatite and basement gneisses is marked by K-feldspar fenite. The pyrochlore chemistry at Epembe shows a compositional trend from primary magmatic Ca-rich pyrochlore toward late hydrothermal fluid enriched carbonatite phase, giving rise to a remarkable shift in chemical composition and invasion of elements such as Si, U, Sr, Ba, Th and Fe. Enrichment in elements like U, Sr and Th lead to metamictization, alteration and A-site vacancy. It is therefore suggested that the carbonatite successive intrusive phases assimilated primary pyrochlore leading to extreme compositional variation especially around the rims of the pyrochlore. The genesis of the Epembe niobium deposit is linked to the carbonatite magmatism but the mechanism that manifested such niobium rich rock remains unclear and might be formed as a result of cumulate process and/or liquid immiscibility of a carbonate-silicate pair.
DS201811-2621
2018
Yang, H.Yang, H., Xiao, J., Yao, Z., Zhang, X., Younus, F., Melnik, R., Wen, B.Homogeneous and heterogenous dislocation nucleation in diamond.Diamond & Related Materials, Vol. 88, pp. 110-117.Mantlediamond morphology

Abstract: Dislocation nucleation plays a key role in plastic deformation of diamond crystal. In this paper, homogeneous and heterogeneous nucleation nature for diamond glide set dislocation and shuffle set dislocation is studied by combining molecular dynamics method and continuum mechanics models. Our results show that although heterogeneous dislocation nucleation can decrease its activation energy, the activation energy at 0?GPa for diamond heterogeneous nucleation is still in the range of 100?eV. For glide set and shuffle set homogeneous nucleation, their critical nucleation shear stress approaches to diamond's ideal shear strength which implies that those dislocations do not nucleate before diamond structural instability only by a purely shearing manner. While for glide set and shuffle set heterogeneous nucleation, their critical nucleation shear stresses are 28.9?GPa and 48.2?GPa, these values are less than diamond's ideal shear strength which implies that these dislocations may be nucleated heterogeneously under certain shear stress condition. In addition, our results also indicate there exists a deformation mode transformation for diamond deformation behavior at strain rate of 10-3/s. Our results provide a new insight into diamond dislocation nucleation and deformation.
DS201906-1317
2019
Yang, H.Liu, J., Wang, W., Yang, H., Wu, Z., Hu, M.Y., Zhao, J., Bi, W., Alp. E.E., Dauphas, N., Liang, W., Chen, B., Lin, J-F.Carbon isotopic signatures of super-deep diamonds mediated by iron redox chemistry.Geochemical Perspectives Letters, Vol. 10, pp. 51-55.Mantleredox

Abstract: Among redox sensitive elements, carbon is particularly important because it may have been a driver rather than a passive recorder of Earth’s redox evolution. The extent to which the isotopic composition of carbon records the redox processes that shaped the Earth is still debated. In particular, the highly reduced deep mantle may be metal-saturated, however, it is still unclear how the presence of metallic phases in?uences the carbon isotopic compositions of super-deep diamonds. Here we report ab initio results for the vibrational properties of carbon in carbonates, diamond, and Fe3C under pressure and temperature conditions relevant to super-deep diamond formation. Previous work on this question neglected the effect of pressure on the equilibrium carbon isotopic fractionation between diamond and Fe3C but our calculations show that this assumption overestimates the fractionation by a factor of ~1.3. Our calculated probability density functions for the carbon isotopic compositions of super-deep diamonds derived from metallic melt can readily explain the very light carbon isotopic compo- sitions observed in some super-deep diamonds. Our results therefore support the view that metallic phases are present during the formation of super-deep diamonds in the mantle below ~250 km.
DS201907-1582
2019
Yang, H.Wang, W., Liu, J., Dauphas, N., Yang, H., Wu, Z., Chen, B., Lin, J-F.Carbon isotopic signatures of diamond formation mediated by iron redox chemistry.Acta Geologica Sinica, Vol. 93, 1, p. 174.Mantleredox

Abstract: Diamonds are key messenger from the deep Earth because someare sourced from the longest isolated and deepest accessible regions of the Earth’s mantle. They are prime recorders of the carbon isotopic compositionof the Earth. The C isotope composition (d13C) of natural diamonds showsa widevariationfrom -41‰ to +3‰ with the primary mode at -5 ± 3‰ [1]. In comparison, the d13C values of chondrites and other planetary bodies range between -26‰ and -15‰ [2]. It is possible that some of the low d13C values were inherited from the Earth’s building blocks,but this is unlikely to be the sole explanation for all low d13C values that can reach as low as -41‰. Organic matter at the Earth’s surface that has low d13C values[3] has been regarded as a possible origin for low d13C values. However, organic carbon is usually accompanied by carbonate with higher d13C values (~0 ‰),and it is not clear why this d13C value does not appear frequently in diamonds. Low d13C diamonds were also formed by deposition from C-O-H fluids,but the equilibrium fractionationinvolved between diamonds and fluids issmall at mantle temperatures [1] and the low d13C values of diamonds can only be achieved after extensive Rayleigh distillation. One unique feature of the Earth isactive plate tectonics driven by mantle convection. Relatively oxidized iron and carbon species at the surface, such as carbonate, Fe2+-and Fe3+-bearing silicatesand oxides, are transported to the deep mantle by subducted slabs and strongly involved inthe redox reactions that generatediamonds [4]. The extent to which the isotopic compositionof C duringdiamond formation recordsredox processes that shaped the Earth is still controversial. Here we report onvibration properties of C andFe at high pressure in carbonates, diamond and Fe3C,based on nuclear resonant inelastic X-ray scattering measurements and density functional theory calculationsand further calculate equilibrium C isotope fractionations among these C-bearing species. Our results demonstrate that redox reactions in subducted slabs could generate eclogitic diamonds with d13C values as low as -41‰ if C in diamonds was sourced from the oxidation of a Fe-C liquid. The large C isotopic fractionation and potentially fast separation between diamonds and a Fe-C melt could enable diamond formation as high as 2%with d13C lower than -40‰.
DS200612-1562
2006
Yang, H-Y.Yang, J., Wu, C., Zhang, J., Shi, R., meng, F.,Wooden, J., Yang, H-Y.Protolith of eclogites in the north Qaidam and Altun UHP terrane, NW China: earlier oceanic crust?Journal of Asian Earth Sciences, In press, availableChinaUHP, subduction, eclogites
DS1996-1576
1996
Yang, J.Yang, J.Study on the mineralogy and petrology of kimberlite from Yingxian County, Shanxi Province.International Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 397.ChinaMineralogy, Deposit - Yingxian County
DS2001-0073
2001
Yang, J.Bai, W., Yang, J., Fang, Yan, ZhangExplosion of ultrahigh pressure minerals in the mantleActa Geologica Sinica, Vol. 22, No. 5, pp. 385-90.MantleUHP
DS2001-1278
2001
Yang, J.Yang, J., Xu, Z., Zhang, J., Chu, C.Y., Zhang, R., LiouTectonic significance of early Paleozoic high pressure rocks in Altun Qaidam Qilian Mountains, northwest.Geological Society of America Memoir, No. 194, pp. 151-70.China, northwestTectonics, ultra high pressure metamorphism
DS2001-1303
2001
Yang, J.Zhang, J., Zhang, Z., Xu, Z., Yang, J., Cui. J.Petrology and geochronology of eclogites from the western segment of the Altyn Tagh, northwestern China.Lithos, Vol. 56, No. 2-3, Mar.pp. 187-206.ChinaGeochronology, Eclogites
DS2003-1313
2003
Yang, J.Song, S., Yang, J., Liou, J.G., Wu, C., Shi, R., Xu, Z.Petrology, geochemistry and isotopic ages of eclogites from the Dulan UHPM terraneLithos, Vol. 70, 3-4, pp. 195-211.ChinaUHP, geochronology
DS2003-1516
2003
Yang, J.Yang, J.Two ultrahigh pressure metamorphic events recognized in the central orogenic belt ofGeological Society of America, Annual Meeting Nov. 2-5, Abstracts p.226.ChinaUHP, geochronology
DS200412-1878
2003
Yang, J.Song, S., Yang, J., Liou, J.G., Wu, C., Shi, R., Xu, Z.Petrology, geochemistry and isotopic ages of eclogites from the Dulan UHPM terrane, the North Qaidam NW China.Lithos, Vol. 70, 3-4, pp. 195-211.ChinaUHP, geochronology
DS200412-2168
2003
Yang, J.Yang, J.Two ultrahigh pressure metamorphic events recognized in the central orogenic belt of China: evidence from the U Pb dating of coeGeological Society of America, Annual Meeting Nov. 2-5, Abstracts p.226.ChinaUHP, geochronology
DS200412-2169
2003
Yang, J.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
DS200512-1210
2004
Yang, J.Xu, Z., Jiang, M., Yang, J.Mantle structure of Qinghai Tibet Plateau: mantle plume, mantle shear zone and delamination of lithospheric slab.Earth Science Frontiers, Vol. 11, 4, pp. 329-344. Ingenta 1045384775China, TibetSubduction
DS200612-0071
2006
Yang, J.Bai, W., Ren, Y., Yang, J., Fang, Q., Yan, B.The native iron and wustite assemblage: records of oxygen element from the mantle.Acta Geologica Sinica , Vol. 27, 1, pp. 43-50.MantleMineral chemistry
DS200612-1561
2006
Yang, J.Xu, Z., Zeng, L., Liu, F., Yang, J., Zhang, Z., McWilliams, M., Liou, J.G.Polyphase subduction and exhumation of the Sulu high pressure ultrahigh pressure metamorphic terrane.Geological Society of America, Special Paper, No. 403, pp. 93-114.ChinaSubduction UHP
DS200612-1562
2006
Yang, J.Yang, J., Wu, C., Zhang, J., Shi, R., meng, F.,Wooden, J., Yang, H-Y.Protolith of eclogites in the north Qaidam and Altun UHP terrane, NW China: earlier oceanic crust?Journal of Asian Earth Sciences, In press, availableChinaUHP, subduction, eclogites
DS200612-1603
2006
Yang, J.Zheng, J., Griffin, W.L., O'Reilly, S.Y., Yang, J., Li, T., Zhang, M., Zhang, R., Liou, J.G.Mineral chemistry of peridotites from Paleozoic, Mesozoic and Cenozoic lithosphere: constraints on mantle evolution beneath eastern China.Journal of Petrology, Vol. 47, 11, pp. 2233-2256.ChinaPeridotite
DS200712-0491
2007
Yang, J.Jiang, N., Liu, Y., Zhou, W., Yang, J., Zhang, S.Derivation of Mesozoic adakitic magmas from ancient lower crust in the North Chin a craton.Geochimica et Cosmochimica Acta, Vol. 71, 10, May 15, pp. 2591-2608.ChinaSubduction
DS200912-0177
2008
Yang, J.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
DS200912-0827
2008
Yang, J.Xu, S., Wu, W., Xiao, W., Yang, J., Chen, J., Ji, S., Liu, Y.Moissanite in serpentine from the Dabie Mountains in China.Mineralogical Magazine, Vol. 72, 4, pp. 899-908.ChinaUHP
DS200912-0832
2009
Yang, J.Yang, J.Diamonds in ophiolitic mantle rocks and podiform chromitites an unsolved mystery.GAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyMantleDiamond genesis
DS201012-0871
2010
Yang, J.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
DS201012-0872
2010
Yang, J.Yang, J., Zhang, Z., Xu, X., Li, Y., Li, J., Jia, Y., Liu, Z., Ba, D.Diamond in the Purang peridotite Massif, west of the Yarlung Zangbu Suture, Tibet: a new discovery.Goldschmidt 2010 abstracts, abstractAsia, TibetPurang Massif
DS201112-1131
2011
Yang, J.Yang, J., Xu, X., Li, Y., Liu, Z., Li, J., Ba, D., Robinson, P.T.Diamond discovered from six different ultramafic massifs along the Yarlung Zangbu suture between the Indian and Eurasian plates.Geological Society of America, Annual Meeting, Minneapolis, Oct. 9-12, abstractAsia, IndiaMantle harzburgites
DS201212-0801
2012
Yang, J.Yang, J., Wirth, R., Xu, X., Robinson, P.T., Rong, H.Mineral inclusions in diamonds from ophiolitic peridotite and chromites.GSA Annual Meeting, Paper no. 74-4, abstractChina, TibetDiamond inclusions
DS201312-0979
2013
Yang, J.Wirth, R., Yang, J.Sources of diamond formation revealed by nano-inclusions in diamond.GAC-MAC 2013 SS4: Diamond: from birth in the mantle to emplacement in kimberlite, abstract onlyMantleDiamond inclusions
DS201312-0990
2012
Yang, J.Yang, J., Wirth, R., Xianhzhen, X., Robinson, P.T., Rong, H.Mineral inclusions in diamonds from ophiolitic peridotite and chromities.Geological Society of America Annual Meeting abstract, Paper 74-4, 1/2p. AbstractTechnologyDiamond inclusions
DS201312-0991
2013
Yang, J.Yang, J., Xu, X., Robinson, P.T.Ophiolite type diamond.Geological Society of America Annual Meeting, Vol. 45, 7, p. 451 abstractTechnologyDiamond genesis
DS201412-0547
2014
Yang, J.Mao, Z., Lin, J-F., Yang, J., Bian, H., Liu, J., Watson, H.C., Huang, S., Chen, J., Prakapenka, V.B., Xiao, Y., Chow, P.Fe, Al bearing post-perovskite in the Earth's lower mantle.Earth and Planetary Science Letters, Vol. 403, pp. 157-163.MantlePerovskite
DS201412-0998
2014
Yang, J.Yang, J.Diamonds and highly reduced minerals in ophiolitic mantle rocks and chromitites.ima2014.co.za, AbstractMantleDiamond mineralogy
DS201412-0999
2014
Yang, J.Yang, J., Meng, F., Xu, X., Robinson, P.T., Dilek, Y., Makeyev, A.B., Wirth, R., Wiedenbeck, M., Cliff, J.Diamonds, native elements and metal alloys from chromitites of the Ray-Iz ophiolite of the Polar Urals.Gondwana Research, Vol. 27, 2, pp. 459-485.Asia, TibetUHP ophiolite diamonds
DS201502-0126
2014
Yang, J.Yang, J., Meng, F., Xu, X., Robinson, P.T., Dilek, Y., Makeyev, A.B., Wirth, R., Wiedenbeck, M., Cliff, J.Diamonds, native elements and metal alloys from chromitites of the Ray-Iz ophiolite of the Polar Urals.Gondwana Research, Vol. 27, 2, pp. 459-485.Russia, UralsChromitite
DS201506-0297
2015
Yang, J.Tian, Y., Yang, J., Robinson, P.T., Xiong, F., Li, Y., Zhang, Z., Liu, Z., Liu, F., Niu, X.Diamond discovered in high Al chromitites of the Sartohay ophiolite, Xinjiang province China.Acta Geologica Sinica, Vol. 89, 2, pp. 332-340.ChinaChromitite
DS201506-0302
2015
Yang, J.Zhu, H., Yang, J., Robinson, P.T., Zhu, Y., Zhu, F., Zhao, X., Liu, Z., Zhang, W., Xu, W.The discovery of diamonds in chromitites of the Hegenshan ophiolite, Inner Mongolia, China.Acta Geologica Sinica, Vol. 89, 2, pp. 341-350.China, MongoliaChromitite
DS201512-1994
2015
Yang, J.Yang, J., Dilek, Y., Robinson, P.T.Diamond and recycled mantle: a new perspectve - introduction of IGCP 649 project. OphiolitesActa Geologica Sinica, Vol. 89, 3, pp. 1036-1038.MantleDiamond genesis
DS201601-0019
2015
Yang, J.Huang, Yang, J., Zhu, Y., Xiong, F., Liu, Z., Zhang, Z., Xu, W.The discovery of diamonds in chromitite of the Hegenshan ophiolite, Inner Mongolia.Acta Geologica Sinica, Vol. 89, 2, p. 32.Asia, MongoliaOphiolite

Abstract: Diamond, moissanite and a variety of other minerals, similar to those reported from ophiolites in Tibet and northern Russia, have recently been discovered in chromitites of the Hegenshan ophiolite of the Central Asian Orogenic Belt, north China. The chromitites are small, podiform and vein-like bodies hosted in dunite, clinopyroxene-bearing peridotite, troctolite and gabbro. All of the analysed chromite grains are relatively Al-rich, with Cr# [100Cr/(Cr+Al)] of about 47-53. Preliminary studies of mainly disseminated chromitite from ore body No. 3756 have identified more than 30 mineral species in addition to diamond and moissanite. These include oxides (mostly hematite, magnetite, rutile, anatase, cassiterite, and quartz), sulfides (pyrite, marcasite and others), silicates (magnesian olivine, enstatite, augite, diopside, uvarovite, pyrope, orthoclase, zircon, sphene, vesuvianite, chlorite and serpentine) and others (e.g., calcite, monazite, glauberite, iowaite and a range of metallic alloys). This study demonstrates that diamond, moissanite and other exotic minerals can occur in high-Al, as well as high-Cr chromites, and significantly extends the geographic and age range of known diamond-bearing ophiolites.
DS201601-0050
2015
Yang, J.Yang, J., Wirth, R., Xiong, F., Tian, Y., Huang, Z., Robinson, P.T., Dilek, Y.The lower mantle minerals in ophiolite hosted diamond.Acta Geologica Sinica, Vol. 89, 2, pp. 108-109.MantleMineralogy
DS201603-0395
2015
Yang, J.Lian, D., Yang, J., Dilek, Y., Robinson, P.T., Wu, W., Wang, Y., Liu, F., Ding, Yi.Diamonds and moissanite from the aladag ophiolite of the eastern Tauride belt, southern Turkey: a final report.Geological Society of America Annual Meeting, Vol. 47, 7, p. 163. abstractEurope, TurkeyMoissanite

Abstract: The Aladag ophiolite in the eastern Tauride belt, southern Turkey, is a well-preserved remnant of oceanic lithosphere. It consists of, in ascending order, harzburgitic to dunitic tectonites, ultramafic and mafic cumulates, isotropic gabbros, sheeted dikes and basaltic pillow lavas. Podiform chromitites are common in the mantle peridotites. Thus far, more than 200 grains of microdiamond and more than 100 grains of moissanite (SiC) have been separated from one sample of podiform chromitite. The microdiamonds occur mostly as subhedral to euhedral, colorless to pale yellow grains, about 50-300 µm in size. Moissanite grains are generally subhedral, light blue to deep blue in color and variable in size. These grains of diamond and moissanite are very similar to in-situ grains in podiform chromitites of Tibet and the Polar Urals of Russia (Yang et al., 2014; 2015), indicating that they are natural minerals, not the result of natural or anthropogenic contamination. As reported elsewhere, the diamonds and moissanite are accompanied by a range of other minerals, including rutile, zircon, quartz and sulfides. The discovery of diamond, moissanite and other unusual minerals in the podiform chromitites of the Aladag massif provide additional evidence for the widespread occurrence of these minerals in ophiolites, indicating that they are related to global mantle processes.
DS201605-0922
2016
Yang, J.Xiong, F., Yang, J., Robinson, P.T., Xu, X., Ba, D., Li, Y., Zhang, Z., Rong, H.Diamonds ad other exotic minerals recovered from peridotites of the Dangqiong ophiolite, western Yarlung-Zangbo suture zone, Tibet.Acta Geologica Sinica, Vol. 90, 2, pp. 425-439.Asia, TibetPeridotite

Abstract: Various combinations of diamond, moissanite, zircon, quartz, corundum, rutile, titanite, almandine garnet, kyanite, and andalusite have been recovered from the Dangqiong peridotites. More than 80 grains of diamond have been recovered, most of which are pale yellow to reddish-orange to colorless. The grains are all 100-200 µm in size and mostly anhedral, but with a range of morphologies including elongated, octahedral and subhedral varieties. Their identification was confirmed by a characteristic shift in the Raman spectra between 1325 cm-1 and 1333 cm-1, mostly at 1331.51 cm-1 or 1326.96 cm-1. Integration of the mineralogical, petrological and geochemical data for the Dongqiong peridotites suggests a multi-stage formation for this body and similar ophiolites in the Yarlung-Zangbo suture zone. Chromian spinel grains and perhaps small bodies of chromitite crystallized at various depths in the upper mantle, and encapsulated the UHP, highly reduced and crustal minerals. Some oceanic crustal slabs containing the chromian spinel and their inclusion were later trapped in suprasubduction zones (SSZ), where they were modified by island arc tholeiitic and boninitic magmas, thus changing the chromian spinel compositions and depositing chromitite ores in melt channels.
DS201606-1093
2015
Yang, J.Howell, D., Griffin, W.L., Yang, J., Gain, S., Stern, R.A., Huang, J-X., Jacob, D.E., Xu, X., Stokes, A.J., O'Reilly, S.Y., Pearson, N.J.Diamonds in ophiolites: contamination or a new diamond growth environment?Earth and Planetary Science Letters, Vol. 430, pp. 284-295.Asia, TibetLuobusa Massif Type Iib

Abstract: For more than 20 years, the reported occurrence of diamonds in the chromites and peridotites of the Luobusa massif in Tibet (a complex described as an ophiolite) has been widely ignored by the diamond research community. This skepticism has persisted because the diamonds are similar in many respects to high-pressure high-temperature (HPHT) synthetic/industrial diamonds (grown from metal solvents), and the finding previously has not been independently replicated. We present a detailed examination of the Luobusa diamonds (recovered from both peridotites and chromitites), including morphology, size, color, impurity characteristics (by infrared spectroscopy), internal growth structures, trace-element patterns, and C and N isotopes. A detailed comparison with synthetic industrial diamonds shows many similarities. Cubo-octahedral morphology, yellow color due to unaggregated nitrogen (C centres only, Type Ib), metal-alloy inclusions and highly negative View the MathML sourcedC13 values are present in both sets of diamonds. The Tibetan diamonds (n=3n=3) show an exceptionally large range in View the MathML sourcedN15 (-5.6 to +28.7‰+28.7‰) within individual crystals, and inconsistent fractionation between {111} and {100} growth sectors. This in contrast to large synthetic HPHT diamonds grown by the temperature gradient method, which have with View the MathML sourcedN15=0‰ in {111} sectors and +30‰+30‰ in {100} sectors, as reported in the literature. This comparison is limited by the small sample set combined with the fact the diamonds probably grew by different processes. However, the Tibetan diamonds do have generally higher concentrations and different ratios of trace elements; most inclusions are a NiMnCo alloy, but there are also some small REE-rich phases never seen in HPHT synthetics. These characteristics indicate that the Tibetan diamonds grew in contact with a C-saturated Ni-Mn-Co-rich melt in a highly reduced environment. The stable isotopes indicate a major subduction-related contribution to the chemical environment. The unaggregated nitrogen, combined with the lack of evidence for resorption or plastic deformation, suggests a short (geologically speaking) residence in the mantle. Previously published models to explain the occurrence of the diamonds, and other phases indicative of highly reduced conditions and very high pressures, have failed to take into account the characteristics of the diamonds and the implications for their formation. For these diamonds to be seriously considered as the result of a natural growth environment requires a new understanding of mantle conditions that could produce them.
DS201607-1387
2016
Yang, J.Yang, J., Dilek, Y., Pearce, J., Schertl, H-P., Zhang, C.Diamonds and crustal recycling into deep mantle.IGC 35th., Session The Deep Earth 1 p. abstractMantleSubduction
DS201612-2349
2016
Yang, J.Yang, J., Robinson, P.T., Dilek, Y.Geological occurrences of diamond-bearing ophiolites.Acta Geologica Sinica, Vol. 90, 1, July abstract P. 216GlobalUHP
DS201709-2076
2017
Yang, J.Xiong, F., Yang, J., Robinson, P.T., Dilek, Y., Milushi, I., Xu, X., Zhou, W., Zhang, Z., Rong, H.Diamonds discovered from high-Cr podiform chromitites from Bulqiza, eastern Mirdita ophiolite, Albania.Acta Geologica Sinica, Vol. 91, 2, pp. 455-468.Europe, Albaniadiamonds in chromitites

Abstract: Various combinations of diamond, moissanite, zircon, corundum, rutile and titanitehave been recovered from the Bulqiza chromitites. More than 10 grains of diamond have been recovered, most of which are pale yellow to reddish–orange to colorless. The grains are all 100–300 µm in size and mostly anhedral, but with a range of morphologies including elongated, octahedral and subhedral varieties. Their identification was confirmed by a characteristic shift in the Raman spectra between 1325 cm-1 and 1333 cm-1, mostly at 1331.51 cm-1 or 1326.96 cm-1. This investigation extends the occurrence of diamond and moissanite to the Bulqiza chromitites in the Eastern Mirdita Ophiolite. Integration of the mineralogical, petrological and geochemical data of the Bulqiza chromitites suggests their multi–stage formation. Magnesiochromite grains and perhaps small bodies of chromitite formed at various depths in the upper mantle, and encapsulated the ultra–high pressure, highly reduced and crustal minerals. Some oceanic crustal slabs containing the magnesiochromite and their inclusion were later trapped in suprasubduction zones, where they were modified by tholeiitic and boninitic arc magmas, thus changing the magnesiochromite compositions and depositing chromitite ores in melt channels.
DS201710-2240
2017
Yang, J.Lian, D., Yang, J., Dilek, Y., Wu, W., Zhang, Z., Xiong, F., Liu, F., Zhou, W.Deep mantle origin and ultra-reducing conditions in podiform chromitite: diamonds, moissanite, and other unusual minerals in podiform chromitites from the Pozanti-Karsanti ophiolite, southern Turkey.Americam Mineralogist, Vol. 103, 5p.Europe, Turkeymoissanites

Abstract: The Pozanti-Karsanti ophiolite situated in the eastern Tauride belt, southern Turkey, is a well-preserved oceanic lithosphere remnant comprising, in ascending order, mantle peridotite, ultramafic and mafic cumulates, isotropic gabbros, sheeted dikes, and basaltic pillow lavas. Two types of chromitites are observed in the Pozanti-Karsanti ophiolite. One type of chromitites occurs in the cumulate dunites around the Moho, and the other type of chromitites is hosted by the mantle harzburgites below the Moho. The second type of chromitites has massive, nodular, and disseminated textures. We have conducted the mineral separation work on the podiform chromitites hosted by harzburgites. So far, more than 100 grains of microdiamond and moissanite (SiC) have been recovered from the podiform chromitite. The diamonds and moissanite are accompanied by large amounts of rutile. Besides zircon, monazite and sulfide are also very common phases within the separated minerals. The discovery of diamond, moissanite, and the other unusual minerals from podiform chromitite of the Pozanti-Karsanti ophiolite provides new evidences for the common occurrences of these unusual minerals in ophiolitic peridotites and chromitites. This discovery also suggests that deep mantle processes and materials have been involved in the formation of podiform chromitite.
DS201710-2262
2017
Yang, J.Robinson, P.T., Yang, J., Tian, Y., Zhu, H.Diamonds, super reduced and crustal minerals in chromitites of the Hegenshan and Sartohay ophiolites, central Asian orogenic belt, China.Acta Geologica Sinica, Vol. 91, s1, p. 32 abstractChinadiamond inclusions

Abstract: The Central Asian Orogenic Belt (CAOB) is a huge tectonic mélange that lies between the North China Craton and the Siberian Block. It is composed of multiple orogenic belts, continental fragments, magmatic and metamorphic rocks, suture zones and discontinuous ophiolite belts. Although the Hegenshan and Sartohay ophiolites are separated by nearly 3000 km and lie in completely different parts of the CAOB, they are remarkably similar in many respects. Both are composed mainly of serpentinized peridotite and dunite, with minor gabbro and sparse basalt. They both host significant podiform chromitites that consist of high-Al, refractory magnesiochromite with Cr#s [100Cr/(Cr+Al)] averaging >60. The Sartohay ophiolite has a zircon U-Pb age of ca. 300 Ma and has been intruded by granitic plutons of similar age, resulting in intense hydrothermal activity and the formation of gold-bearing listwanites. The age of the Hegenshan is not firmly established but is thought to have formed in the Carboniferous. Like many other ophiolites that we have investigated in other orogenic belts, the chromitites in these two bodies have abundant diamonds, as well as numerous super-reduced and crustal minerals. The diamonds are mostly, colorless to pale yellow, 200-300 µm across and have euhedral to anhedral shapes. They all have low carbon isotopes (d14C = -18 to -29) and some have visible inclusions. These are accompanied by numerous super-reduced minerals such as moissanite, native elements (Fe, Cr, Si, Al, Mn), and alloys (e.g., Ni-Mn-Fe, Ni-Fe-Al, Ni-Mn-Co, Cr-Ni-Fe, Cr-Fe, Cr-Fe-Mn), as well as a wide range of oxides, sulfides and silicates. Grains of zircon are abundant in the chromitites of both ophiolites and range in age from Precambrian to Cretaceous, reflecting both incorporation of old zircons and modification of grains by hydrothermal alteration. Our investigation confirms that high-Al, refractory chromitites in these two ophiolites have the same range of exotic minerals as high-Cr metallurgical chromitites such as those in the Luobusa ophiolite of Tibet. These collections of exotic minerals in ophiolitic chromitites indicate complex, multi-stage recycling of oceanic and continental crustal material at least to the mantle transition zone, followed by uprise and emplacement of the peridotites into relatively shallow ophiolites.
DS201710-2279
2017
Yang, J.Wu, W., Yang, J., Ma, C., Milushi, I., Lian, D., Tian, Y.Discovery and significance of diamonds and moissanites in chromitites within the Skenderbeu Massif of the Mirdita zone ophiolite, west Albania.Acta Geologica Sinica, Vol. 91, 3, pp. 882-897.Europe, Albaniamoissanites

Abstract: In recent years diamonds and other unusual minerals (carbides, nitrides, metal alloys and native elements) have been recovered from mantle peridotites and chromitites (both high-Cr chromitites and high-Al chromitites) from a number of ophiolites of different ages and tectonic settings. Here we report a similar assemblage of minerals from the Skenderbeu massif of the Mirdita zone ophiolite, west Albania. So far, more than 20 grains of microdiamonds and 30 grains of moissanites (SiC) have been separated from the podiform chromitite. The diamonds are mostly light yellow, transparent, euhedral crystals, 200-300 µm across, with a range of morphologies; some are octahedral and cuboctahedron and others are elongate and irregular. Secondary electron images show that some grains have well-developed striations. All the diamond grains have been analyzed and yielded typical Raman spectra with a shift at ~1325 cm-1. The moissanite grains recovered from the Skenderbeu chromitites are mainly light blue to dark blue, but some are yellow to light yellow. All the analyzed grains have typical Raman spectra with shifts at 766 cm-1, 787 cm-1, and 967 cm-1. The energy spectrums of the moissanites confirm that the grains are composed entirely of silicon and carbon. This investigation expands the occurrence of diamonds and moissanites to Mesozoic ophiolites in the Neo-Tethys. Our new findings suggest that diamonds and moissanites are present, and probably ubiquitous in the oceanic mantle and can provide new perspectives and avenues for research on the origin of ophiolites and podiform chromitites.
DS201711-2537
2017
Yang, J.Zhu, R., Zhang, H., Zhu, G., Meng, H., Fan, H., Yang, J., Wu, F., Zhang, Z.Craton destruction and related resources.International Journal of Earth Sciences, Vol. 106, 7, pp. 2233-2257.Chinacraton

Abstract: Craton destruction is a dynamic event that plays an important role in Earth’s evolution. Based on comprehensive observations of many studies on the North China Craton (NCC) and correlations with the evolution histories of other cratons around the world, craton destruction has be defined as a geological process that results in the total loss of craton stability due to changes in the physical and chemical properties of the involved craton. The mechanisms responsible for craton destruction would be as the follows: (1) oceanic plate subduction; (2) rollback and retreat of a subducting oceanic plate; (3) stagnation and dehydration of a subducting plate in the mantle transition zone; (4) melting of the mantle above the mantle transition zone caused by dehydration of a stagnant slab; (5) non-steady flow in the upper mantle induced by melting, and/or (6) changes in the nature of the lithospheric mantle and consequent craton destruction caused by non-steady flow. Oceanic plate subduction itself does not result in craton destruction. For the NCC, it is documented that westward subduction of the paleo-Pacific plate should have initiated at the transition from the Middle-to-Late Jurassic, and resulted in the change of tectonic regime of eastern China. We propose that subduction, rollback and retreat of oceanic plates and dehydration of stagnant slabs are the main dynamic factors responsible for both craton destruction and concentration of mineral deposits, such as gold, in the overriding continental plate. Based on global distribution of gold deposits, we suggest that convergent plate margins are the most important setting for large gold concentrations. Therefore, decratonic gold deposits appear to occur preferentially in regions with oceanic subduction and overlying continental lithospheric destruction/modification/growth.
DS201802-0261
2017
Yang, J.Robinson, P.T., Yang, J., Tian, Y., Zhu, H.Diamonds, super reduced and crustal minerals in chromitites of the Hegenshan and Sartohay ophiolites, central Asian orogenic belt, China.Acta Geologica Sinica, Vol. 91, 1, p. 32.Asia, Chinamineralogy

Abstract: The Central Asian Orogenic Belt (CAOB) is a huge tectonic mélange that lies between the North China Craton and the Siberian Block. It is composed of multiple orogenic belts, continental fragments, magmatic and metamorphic rocks, suture zones and discontinuous ophiolite belts. Although the Hegenshan and Sartohay ophiolites are separated by nearly 3000 km and lie in completely different parts of the CAOB, they are remarkably similar in many respects. Both are composed mainly of serpentinized peridotite and dunite, with minor gabbro and sparse basalt. They both host significant podiform chromitites that consist of high-Al, refractory magnesiochromite with Cr#s [100Cr/(Cr+Al)] averaging >60. The Sartohay ophiolite has a zircon U-Pb age of ca. 300 Ma and has been intruded by granitic plutons of similar age, resulting in intense hydrothermal activity and the formation of gold-bearing listwanites. The age of the Hegenshan is not firmly established but is thought to have formed in the Carboniferous.Like many other ophiolites that we have investigated in other orogenic belts, the chromitites in these two bodies have abundant diamonds, as well as numerous super-reduced and crustal minerals. The diamonds are mostly, colorless to pale yellow, 200-300 µm across and have euhedral to anhedral shapes. They all have low carbon isotopes (d14C = -18 to -29) and some have visible inclusions. These are accompanied by numerous super-reduced minerals such as moissanite, native elements (Fe, Cr, Si, Al, Mn), and alloys (e.g., Ni-Mn-Fe, Ni-Fe-Al, Ni-Mn-Co, Cr-Ni-Fe, Cr-Fe, Cr-Fe-Mn), as well as a wide range of oxides, sulfides and silicates. Grains of zircon are abundant in the chromitites of both ophiolites and range in age from Precambrian to Cretaceous, reflecting both incorporation of old zircons and modification of grains by hydrothermal alteration. Our investigation confirms that high-Al, refractory chromitites in these two ophiolites have the same range of exotic minerals as high-Cr metallurgical chromitites such as those in the Luobusa ophiolite of Tibet. These collections of exotic minerals in ophiolitic chromitites indicate complex, multi-stage recycling of oceanic and continental crustal material at least to the mantle transition zone, followed by uprise and emplacement of the peridotites into relatively shallow ophiolites.
DS201804-0685
2018
Yang, J.Dilek, Y., Yang, J.Ophiolites, diamonds, and ultrahigh pressure minerals: new discoveries and concepts on upper mantle petrogenesis.Lithosphere, Vol. 10, 1, pp. 3-13.MantleUHP - metasomatism

Abstract: Ophiolitic peridotites represent variously depleted residues of the primitive mantle after multiple episodes of partial melting, melt extraction, and melt-rock interactions. They display a wide range of compositional and geochemical heterogeneities at different scales, and their incompatible bulk-rock compositions and mineral chemistries are commonly inconsistent with their evolution through simple partial melting processes at shallow mantle depths. Approaching these issues from different perspectives, the papers in this volume concentrate on (1) melt evolution and magmatic construction of ophiolites in various tectonic settings, and (2) the occurrence of microdiamonds, ultrahigh-pressure (UHP) minerals, and crustal material as inclusions in ophiolitic chromitites and peridotites. Crustal and mantle rock units exposed in different ophiolites show that the mantle melt sources of ophiolitic magmas undergo progressive melting, depletion, and enrichment events, constantly modifying the melt compositions and the mineralogical and chemical makeup of residual peridotites. Formation and incorporation of microdiamonds and UHP minerals into chromite grains occurs at depths of 350-660 km in highly reducing conditions of the mantle transition zone. Carbon for microdiamonds and crustal minerals are derived from subduction-driven recycling of surface material. Host peridotites with their UHP mineral and diamond inclusions are transported into shallow mantle depths by asthenospheric upwelling, associated with either slab rollback-induced channel flow or superplumes. Decompression melting of transported mantle rocks beneath oceanic spreading centers and their subsequent flux melting in mantle wedges result in late-stage formation of podiform chromitites during the upper mantle petrogenesis of ophiolites. Future studies should demonstrate whether diamonds and UHP minerals also occur in peridotites and chromitites of nonsubduction-related ophiolites.
DS201805-0993
2018
Yang, J.Xiong, F., Yang, J., Xu, X., Kapsiotis, A., Hao, X., Liu, Z.Compositional and isotopic heterogeneities in the Neo-Tethyan upper mantle recorded by coexisting Al rich and Cr rich chromitites in the Purang massif, SW Tibet (China).Journal of Asian Earth Sciences, Vol. 159, pp. 109-129.China, Tibetchromitites

Abstract: The Purang harzburgite massif in SW Tibet (China) hosts abundant chrome ore deposits. Ores consist of 20 to >95% modal chromian spinel (Cr-spinel) with mylonitic fabric in imbricate shaped pods. The composition of Cr-spinel in these ores ranges from Al-rich [Cr#Sp or Cr/(Cr?+?Al)?×?100?=?47.60-57.56] to Cr-rich (Cr#Sp: 62.55-79.57). Bulk platinum-group element (PGE) contents of chromitites are also highly variable ranging from 17.5?ppb to ~2.5?ppm. Both metallurgical and refractory chromitites show a general enrichment in the IPGE (Os, Ir and Ru) with respect to the PPGE (Rh, Pt and Pd), resulting mostly in right-sloping primitive mantle (PM)-normalized PGE profiles. The platinum-group mineral (PGM) assemblages of both chromitite types are dominated by heterogeneously distributed, euhedral Os-bearing laurite inclusions in Cr-spinel. The Purang chromitites have quite inhomogeneous 187Os/188Os ratios (0.12289-0.13194) that are within the range of those reported for mantle-hosted chromitites from other peridotite massifs. Geochemical calculations demonstrate that the parental melts of high-Cr chromitites were boninitic, whereas those of high-Al chromitites had an arc-type tholeiitic affinity. Chromite crystallization was most likely stimulated by changes in magma compositions due to melt-peridotite interaction, leading to the establishment of a heterogeneous physicochemical environment during the early crystallization of the PGM. The highly variable PGE contents, inhomogeneous Os-isotopic compositions and varying Cr#Sp ratios of these chromitites imply a polygenetic origin for them from spatially distinct melt inputs. The generally low ?Os values (<1) of chromitites indicate that their parental melts originated within different sections of a heterogeneously depleted mantle source region. These melts were most likely produced in the mantle wedge above a downgoing lithospheric slab.
DS201807-1538
2015
Yang, J.Yang, J., Robinson, P.T., Dilek, Y.Diamond bearing ophiolites and their geological occurrence. ** note dateEpisodes, Vol. 38, 4, pp. 344-364.China, Tibet, Russiaophiolites

Abstract: We document in this study the geological occurrence of diamonds and other ultrahigh-pressure (UHP) minerals in ophiolitic mantle peridotites and podiform chromitites from different orogenic belts. These minerals exist in both high-Cr and high-Al chromitites. Most ophiolite-hosted diamonds are small (~ 200-500 µm across), and some contain distinctive inclusions (i.e., coesite, Ni-Mn-Co alloys, spessartite, tephroite). All of the analyzed diamonds have extremely light carbon isotope compositions (d13C = -28.7 to -18.3‰) and variable trace element contents that distinguish them from most kimberlitic and UHP metamorphic varieties. A wide range of highly reduced minerals, such as native elements, Ni-Mn-Co alloys, Fe-Si and Fe-C phases and moissanite (SiC) also occuras accompanying mineral separates confirming the super-reducing conditions of their environment of formation. The presence of exsolution lamellae of diopside and coesite in some chromite grains suggests chromite crystallization depths around >380 km, near the mantle transition zone. Carbon and other recycled crustal materials at these depths are likely to have been derived from previously subducted material. The peridotites encapsulating the podiform chromitites and diamonds were transported to shallow mantle by convection cells beneath oceanic spreading centers. The chromitites may have formed in the deep mantle or in shallow suprasubduction zone environments. Our observations suggest that diamonds, UHP minerals and recycled crustal material are likely to be ubiquitous in the oceanic mantle.
DS201808-1744
2018
Yang, J.Fu, S., Yang, J., Zhang, Y., Okuschi, T., McCammon, C., Kim, H-I., Lee, S.K., Lin, J-F.Abnormal elasticity of Fe bearing bridgmanite in the Earth's lower mantle.Geophysical Research Letters, Vol. 45, 10, pp. 4725-4732.Mantlebridgmanite

Abstract: Seismic heterogeneities in the Earth's lower mantle have been attributed to thermal and/or chemical variations of constituent minerals. Bridgmanite is the most abundant lower-mantle mineral and contains Fe and Al in its structure. Knowing the effect of Fe on compressional and shear wave velocities (VP, VS) and density of bridgmanite at relevant pressure-temperature conditions can help to understand seismic heterogeneities in the region. However, experimental studies on both VP and VS of Fe-bearing bridgmanite have been limited to pressures below 40 GPa. In this study, VP and VS of Fe-bearing bridgmanite were measured up to 70 GPa in the diamond anvil cell. We observed drastic softening of VP by ~6(±1)% at 42.6-58 GPa and increased VS at pressures above 40 GPa. We interpret these observations as due to a spin transition of Fe3+. These observations are different to previous views on the effect of Fe on seismic velocities of bridgmanite. We propose that the abnormal sound velocities of Fe-bearing bridgmanite could help to explain the seismically observed low correlation between VP and VS in the mid-lower mantle. Our results challenge existing models of Fe enrichment to explain the origin of Large Low Shear Velocity provinces in the lowermost mantle.
DS201809-2010
2018
Yang, J.Chen, Y., Yang, J., Xu, Z., Tian, Y., Shengmin, L.Diamonds and other unusual minerals from peridotites of the Myitkyin a ophiolite, Myanmar.Journal of Asian Earth Sciences, Vol. 164, pp. 179-193.Asia, Myanmarperidotites

Abstract: Peridotites from the Myitkyina ophiolite are mainly composed of lherzolite and harzburgite. The lherzolites have relatively fertile compositions, with 39.40-43.40?wt% MgO, 1.90-3.17?wt% Al2O3 and 1.75-2.84?wt% CaO. They contain spinel and olivine with lower Cr# (12.6-18.2) and Fo values (88.7-91.6) than those of the harzburgites (24.5-59.7 and 89.6-91.6 respectively). The harzburgites have more refractory compositions, containing 42.40-46.23?wt% MgO, 0.50-1.64?wt% Al2O3 and 0.40-1.92?wt% CaO. PGE contents of the peridotites show an affinity to the residual mantle. Evaluation of petrological and geochemical characteristics of these peridotites suggests that the lherzolites and harzburgites represent residual mantle after low to moderate degrees of partial melting, respectively, in the spinel stability field. The U-shaped, primitive mantle-normalized REE patterns and strong positive Ta and Pb anomalies of the harzburgites suggest melt/fluid refertilization in either a MOR or SSZ setting after their formation at a MOR. Mineral separation of the peridotites has yield a range of exotic minerals, including diamond, moissanite, native Si, rutile and zircon, a collection similar to that reported for ophiolites of Tibet and the Polar Urals. The discovery of these exotic minerals in the Myitkyina ophiolite supports the view that they occur widely in the upper oceanic mantle.
DS201809-2057
2018
Yang, J.Lian, D., Yang, J., Wiedenbeck, M., Dilek, Y., Rocholl, A., Wu, W.Carbon and nitrogen isotope, and mineral inclusion studies on the diamonds from the Pozanti-Karsanti chromitite, Turkey. MicrodiamondsContributions to Mineralogy and Petrology, doi.org:10.1007/ s00410-018-1499-5 19p.Europe, Turkeydiamond inclusions

Abstract: The Pozanti-Karsanti ophiolite (PKO) is one of the largest oceanic remnants in the Tauride belt, Turkey. Micro-diamonds were recovered from the podiform chromitites, and these diamonds were investigated based on morphology, color, cathodoluminescence, nitrogen content, carbon and nitrogen isotopes, internal structure and inclusions. The diamonds recovered from the PKO are mainly mixed-habit diamonds with sectors of different brightness under the cathodoluminescence images. The total d13C range of the PKO diamonds varies between - 18.8 and - 28.4‰, with a principle d13C mode at - 25‰. Nitrogen contents of the diamonds range from 7 to 541 ppm with a mean value of 171 ppm, and the d15N values range from - 19.1 to 16.6‰, with a d15N mode of - 9‰. Stacking faults and partial dislocations are commonly observed in the Transmission Electron Microscopy foils whereas inclusions are rather rare. Combinations of ( Ca0.81Mn0.19)SiO3, NiMnCo-alloy and nanosized, quenched fluid phases were observed as inclusions in the PKO diamonds. We believe that the 13C-depleted carbon signature of the PKO diamonds derived from previously subducted crustal matter. These diamonds may have crystallized from C-saturated fluids in the asthenospheric mantle at depth below 250 km which were subsequently carried rapidly upward by asthenospheric melts.
DS201901-0046
2018
Yang, J.Lin, J-F, Mao, Z., Yang, J., Fu, F.Elasticity of lower-mantle bridgemanite.Nature, Vol. 564, pp. E18-E26.Mantlebridgmanite
DS201902-0315
2018
Yang, J.Rummel, L., Kaus, B.J.P., White, R.W., Mertz, D.F., Yang, J., Baumann, T.S.Coupled petrological geodynamical modeling of a compositionally heterogeneous mantle plume.Tectonophysics, Vol. 723, pp. 242-260.Mantlehot spot

Abstract: Self-consistent geodynamic modeling that includes melting is challenging as the chemistry of the source rocks continuously changes as a result of melt extraction. Here, we describe a new method to study the interaction between physical and chemical processes in an uprising heterogeneous mantle plume by combining a geodynamic code with a thermodynamic modeling approach for magma generation and evolution. We pre-computed hundreds of phase diagrams, each of them for a different chemical system. After melt is extracted, the phase diagram with the closest bulk rock chemistry to the depleted source rock is updated locally. The petrological evolution of rocks is tracked via evolving chemical compositions of source rocks and extracted melts using twelve oxide compositional parameters. As a result, a wide variety of newly generated magmatic rocks can in principle be produced from mantle rocks with different degrees of depletion. The results show that a variable geothermal gradient, the amount of extracted melt and plume excess temperature affect the magma production and chemistry by influencing decompression melting and the depletion of rocks. Decompression melting is facilitated by a shallower lithosphere-asthenosphere boundary and an increase in the amount of extracted magma is induced by a lower critical melt fraction for melt extraction and/or higher plume temperatures. Increasing critical melt fractions activates the extraction of melts triggered by decompression at a later stage and slows down the depletion process from the metasomatized mantle. Melt compositional trends are used to determine melting related processes by focusing on K2O/Na2O ratio as indicator for the rock type that has been molten. Thus, a step-like-profile in K2O/Na2O might be explained by a transition between melting metasomatized and pyrolitic mantle components reproducible through numerical modeling of a heterogeneous asthenospheric mantle source. A potential application of the developed method is shown for the West Eifel volcanic field.
DS201905-1086
2019
Yang, J.Wu, W., Yang, J., Wirth, R., X=Zheng, J., Lian, D., Qiu, T., Milushi, I.Carbon and nitrogen isotopes and mineral inclusions in diamonds from chromitites of the Mirdita ophiolite ( Albania) demonstrate recycling of oceanic crust into the mantle.American Mineralogist, Vol. 104, pp. 485-500.Europe, Albaniadiamond inclusions

Abstract: Geophysical investigations and laboratory experiments provide strong evidence for subduction of ancient oceanic crust, and geological and mineralogical observations suggest that subducted oceanic crust is recycled into the upper mantle. This model is supported by some direct petrologic and miner-alogical evidence, principally the recovery of super-deep diamonds from kimberlites and the presence of crustal materials in ophiolitic chromitites and peridotites, but many details are still unclear. Here we report the discovery of ophiolite-hosted diamonds in the podiform chromitites of the Skenderbeu massif of the Mirdita ophiolite in the western part of Neo-Tethys. The diamonds are characterized by exceedingly light C isotopes (d13CPDB ~ -25‰), which we interpret as evidence for subduction of organic carbon from Earth's surface. They are also characterized by an exceptionally large range in d 15Nair (-12.9‰ to +25.5‰), accompanied by a low N aggregation state. Materials sparsely included in diamonds include amorphous material, Ni-Mn-Co alloy, nanocrystals (20 × 20 nm) of calcium silicate with an orthorhombic perovskite structure (Ca-Pv), and fluids. The fluids coexisting with the alloy and Ca-Pv provide clear evidence that the diamonds are natural rather than synthetic. We suggest that the Skenderbeu diamonds nucleated and grew from a C-saturated, NiMnCo-rich melt derived from a subducted slab of ocean crust and lithosphere in the deep mantle, at least in the diamond stability field, perhaps near the top of the mantle transition zone. The subsequent rapid upward transport in channeled networks related to slab rollback during subduction initiation may explain the formation and preservation of Skenderbeu diamonds. The discovery of diamonds from the Mirdita ophiolite not only provides new evidence of diamonds in these settings but also provides a valuable opportunity to understand deep cycling of subducted oceanic crust and mantle composition.
DS201907-1586
2019
Yang, J.Xu, X., Cartigny, P., Yang, J., Dilek, Y., Xiong, F., Guo, G.FTIR spectroscopy data and carbon isotope characteristics of the ophiolite hosted diamonds.Acta Geologica Sinica, Vol. 93, 1, p.38.Asia, Russiamicrodiamonds

Abstract: We report new d13C -values data and N-content and N-aggregation state values for microdiamonds recovered from peridotites and chromitites of the Luobusa ophiolite (Tibet) and chromitites of the Ray-Iz ophiolite in the Polar Urals (Russia). All analyzed microdiamonds contain significant nitrogen contents (from 108 up to 589 ± 20% atomic ppm) with a consistently low aggregation state, show identical IR spectra dominated by strong absorption between 1130 cm-1 and 1344 cm-1, and hence characterize Type Ib diamond. Microdiamonds from the Luobusa peridotites have d13C -PDB-values ranging from -28.7‰ to -16.9‰, and N-contents from 151 to 589 atomic ppm. The d13C and N-content values for diamonds from the Luobusa chromitites are -29‰ to -15.5‰ and 152 to 428 atomic ppm, respectively. Microdiamonds from the Ray-Iz chromitites show values varying from -27.6 ‰ to -21.6 ‰ in d13C and from 108 to 499 atomic ppm in N. The carbon isotopes values bear similar features with previously analyzed metamorphic diamonds from other worldwide localities, but the samples are characterized by lower N-contents. In every respect, they are different from diamonds occurring in kimberlites and impact craters. Our samples also differ from the few synthetic diamonds; we also analyzed showing enhanced d13C -variability and less advanced aggregation state than synthetic diamonds. Our newly obtained N-aggregation state and N-content data are consistent with diamond formation over a narrow and rather cold temperature range (i.e. <950°C), and in a short residence time (i.e. within several million years) at high temperatures in the deep mantle.
DS201907-1587
2019
Yang, J.Yang, J., Robinson, P., Xu, X., Xiong, F., Lian, D.Diamond in oceanic peridotites and chromitites: evidence for deep recycled mantle in the global ophiolite record.Acta Geologica Sinica, Vol. 93, 2, p.42.Europe, Turkey, Albania, Russia, Chinamicrodiamonds

Abstract: Diamonds have been discovered in mantle peridotites and chromitites of six ophiolitic massifs along the 1300 km-long Yarlung-Zangbo suture (Bai et al., 1993; Yang et al., 2014; Xu et al., 2015), and in the Dongqiao and Dingqing mantle peridotites of the Bangong-Nujiang suture in the eastern Tethyan zone (Robinson et al., 2004; Xiong et al., 2018). Recently, in-situ diamond, coesite and other UHP mineral have also been reported in the Nidar ophiolite of the western Yarlung-Zangbo suture (Das et al., 2015, 2017). The above-mentioned diamond-bearing ophiolites represent remnants of the eastern Mesozoic Tethyan oceanic lithosphere. New publications show that diamonds also occur in chromitites in the Pozanti-Karsanti ophiolite of Turkey, and in the Mirdita ophiolite of Albania in the western Tethyan zone (Lian et al., 2017; Xiong et al., 2017; Wu et al., 2018). Similar diamonds and associated minerals have also reported from Paleozoic ophiolitic chromitites of Central Asian Orogenic Belt of China and the Ray-Iz ophiolite in the Polar Urals, Russia (Yang et al., 2015a, b; Tian et al., 2015; Huang et al, 2015). Importantly, in-situ diamonds have been recovered in chromitites of both the Luobusa ophiolite in Tbet and the Ray-Iz ophiolite in Russia (Yang et al., 2014, 2015a). The extensive occurrences of such ultra-high pressure (UHP) minerals in many ophiolites suggest formation by similar geological events in different oceans and orogenic belts of different ages. Compared to diamonds from kimberlites and UHP metamorphic belts, micro-diamonds from ophiolites present a new occurrence of diamond that requires significantly different physical and chemical conditions of formation in Earth's mantle. The forms of chromite and qingsongites (BN) indicate that ophiolitic chromitite may form at depths of >150-380 km or even deeper in the mantle (Yang et al., 2007; Dobrthinetskaya et al., 2009). The very light C isotope composition (d13C -18 to -28‰) of these ophiolitic diamonds and their Mn-bearing mineral inclusions, as well as coesite and clinopyroxene lamallae in chromite grains all indicate recycling of ancient continental or oceanic crustal materials into the deep mantle (>300 km) or down to the mantle transition zone via subduction (Yang et al., 2014, 2015a; Robinson et al., 2015; Moe et al., 2018). These new observations and new data strongly suggest that micro-diamonds and their host podiform chromitite may have formed near the transition zone in the deep mantle, and that they were then transported upward into shallow mantle depths by convection processes. The in-situ occurrence of micro-diamonds has been well-demonstrated by different groups of international researchers, along with other UHP minerals in podiform chromitites and ophiolitic peridotites clearly indicate their deep mantle origin and effectively address questions of possible contamination during sample processing and analytical work. The widespread occurrence of ophiolite-hosted diamonds and associated UHP mineral groups suggests that they may be a common feature of in-situ oceanic mantle. The fundamental scientific question to address here is how and where these micro-diamonds and UHP minerals first crystallized, how they were incorporated into ophiolitic chromitites and peridotites and how they were preserved during transport to the surface. Thus, diamonds and UHP minerals in ophiolites have raised new scientific problems and opened a new window for geologists to study recycling from crust to deep mantle and back to the surface.
DS201908-1827
2018
Yang, J.Yang, J., Robinson, P.T., Xu, X., Xiong, F., Lian, D.Diamond in oceanic peridotites and chromitites: evidence for deep recycled mantle in the global ophiolite record.International Symposium on Deep Earth Exploration and Practices, Beijing Oct. 24-26. 1 p. abstractChinadiamond genesis

Abstract: Diamonds have been discovered in mantle peridotites and chromitites of six ophiolitic massifs along the 1300 km-long Yarlung-Zangbo suture (Bai et al., 1993; Yang et al., 2014; Xu et al., 2015), and in the Dongqiao and Dingqing mantle peridotites of the Bangong-Nujiang suture in the eastern Tethyan zone (Robinson et al., 2004; Xiong et al., 2018). Recently, in-situ diamond, coesite and other UHP mineral have also been reported in the Nidar ophiolite of the western Yarlung-Zangbo suture (Das et al., 2015, 2017). The above-mentioned diamond-bearing ophiolites represent remnants of the eastern Mesozoic Tethyan oceanic lithosphere. New publications show that diamonds also occur in chromitites in the Pozanti-Karsanti ophiolite of Turkey, and in the Mirdita ophiolite of Albania in the western Tethyan zone (Lian et al., 2017; Xiong et al., 2017; Wu et al., 2018). Similar diamonds and associated minerals have also reported from Paleozoic ophiolitic chromitites of Central Asian Orogenic Belt of China and the Ray-Iz ophiolite in the Polar Urals, Russia (Yang et al., 2015a, b; Tian et al., 2015; Huang et al, 2015). Importantly, in-situ diamonds have been recovered in chromitites of both the Luobusa ophiolite in Tbet and the Ray-Iz ophiolite in Russia (Yang et al., 2014, 2015a). The extensive occurrences of such ultra-high pressure (UHP) minerals in many ophiolites suggest formation by similar geological events in different oceans and orogenic belts of different ages. Compared to diamonds from kimberlites and UHP metamorphic belts, micro-diamonds from ophiolites present a new occurrence of diamond that requires significantly different physical and chemical conditions of formation in Earth's mantle. The forms of chromite and qingsongites (BN) indicate that ophiolitic chromitite may form at depths of >150-380 km or even deeper in the mantle (Yang et al., 2007; Dobrthinetskaya et al., 2009). The very light C isotope composition (d13C -18 to -28‰) of these ophiolitic diamonds and their Mn-bearing mineral inclusions, as well as coesite and clinopyroxene lamallae in chromite grains all indicate recycling of ancient continental or oceanic crustal materials into the deep mantle (>300 km) or down to the mantle transition zone via subduction (Yang et al., 2014, 2015a; Robinson et al., 2015; Moe et al., 2018). These new observations and new data strongly suggest that micro-diamonds and their host podiform chromitite may have formed near the transition zone in the deep mantle, and that they were then transported upward into shallow mantle depths by convection processes. The in-situ occurrence of micro-diamonds has been well-demonstrated by different groups of international researchers, along with other UHP minerals in podiform chromitites and ophiolitic peridotites clearly indicate their deep mantle origin and effectively address questions of possible contamination during sample processing and analytical work. The widespread occurrence of ophiolite-hosted diamonds and associated UHP mineral groups suggests that they may be a common feature of in-situ oceanic mantle. The fundamental scientific question to address here is how and where these micro-diamonds and UHP minerals first crystallized, how they were incorporated into ophiolitic chromitites and peridotites and how they were preserved during transport to the surface. Thus, diamonds and UHP minerals in ophiolites have raised new scientific problems and opened a new window for geologists to study recycling from crust to deep mantle and back to the surface.
DS201909-2066
2019
Yang, J.Niu, X., Dilek, Y., Liu, F., Feng, G., Yang, J.Early Devonian ultrapotassic magmatism in the North China craton: geochemical and isotopic evidence for subcontinental lithospheric mantle metasomatism by subducted sediment - derived fluids.Geological Magazine, 17p. PdfChinametasomatism

Abstract: We report new U-Pb zircon age data, zircon in situ oxygen isotope, mineral chemistry, whole-rock geochemistry and Sr-Nd isotopic compositions from the Early Devonian ultrapotassic Gucheng pluton in the North China Craton, and discuss its petrogenesis. The Gucheng pluton is exposed in the northern part of the North China Craton and forms a composite intrusion, consisting of K-feldspar-bearing clinopyroxenite, clinopyroxene-bearing syenite and alkali-feldspar syenite. Mineral phases in these lithologies include clinopyroxene (Wo43-48En19-35Fs18-38), sanidine (An0Ab3-11Or89-97), and subordinate titanite, andradite and Na-feldspar. These rocks show homogeneous Sr but variable Nd isotopic compositions, and have relatively high zircon in situ oxygen isotopes (d18O = 5.2-6.7). The Gucheng plutonic rocks formed through fractional crystallization and accumulation from ultrapotassic magmas, which were originated from partial melting of metasomatic vein systems in the subcontinental lithospheric mantle of the North China Craton. These vein networks developed as a result of the reactions of fluids derived from subducted pelitic sediments on the downgoing Palaeo-Asian ocean floor with the enriched, subcontinental lithospheric mantle peridotites. Sensitive high-resolution ion microprobe (SHRIMP) U-Pb zircon dating has revealed a crystallization age of 415 Ma for the timing of the emplacement of the Gucheng pluton that marks the early stages of alkaline magmatism associated with the Andean-type continental margin evolution along the northern edge of the North China Craton facing the Palaeo-Asian Ocean.
DS201909-2109
2019
Yang, J.Yang, J., Lian, D., Robinson, P.T., Qiu, T., Xiong, F., Wu, W.A shallow origin for diamonds in ophiolitic chromitites. Geology, Vol. 47, pp. e475.North America, Mexicomicrodiamonds
DS201910-2280
2019
Yang, J.Lian, D., Yang, J.Ophiolite hosted diamond: a new window for probing carbon cycling in the deep mantle.Engineering, in press available, 23p. PdfMantlecoesite

Abstract: As reported in our prior work, we have recovered microdiamonds and other unusual minerals, including pseudomorph stishovite, moissanite, qingsongite, native elements, metallic alloys, and some crustal minerals (i.e., zircon, quartz, amphibole, and rutile) from ophiolitic peridotites and chromitites. These ophiolite-hosted microdiamonds display different features than kimberlitic, metamorphic, and meteoritic diamonds in terms of isotopic values and mineral inclusions. The characteristic of their light carbon isotopic composition implies that the material source of ophiolite-hosted diamonds is surface-derived organic matter. Coesite inclusions coexisting with kyanite rimming an FeTi alloy from the Luobusa ophiolite show a polycrystalline nature and a prismatic habit, indicating their origin as a replacement of stishovite. The occurrence in kyanite and coesite with inclusions of qingsongite, a cubic boron nitride mineral, and a high-pressure polymorph of rutile (TiO2 II) point to formation pressures of 10-15?GPa at temperatures ~1300?°C, consistent with depths greater than 380?km, near the mantle transition zone (MTZ). Minerals such as moissanite, native elements, and metallic alloys in chromite grains indicate a highly reduced environment for ophiolitic peridotites and chromitites. Widespread occurrence of diamonds in ophiolitic peridotites and chromitites suggests that the oceanic mantle may be a more significant carbon reservoir than previously thought. These ophiolite-hosted diamonds have proved that surface carbon can be subducted into the deep mantle, and have provided us with a new window for probing deep carbon cycling.
DS202003-0372
2020
Yang, J.Yang, J., Simakov, S.K., Moe, K., Scribano, V., Lian, D., Wu, W.Comment on the Comparison of enigmatic diamonds from Tolbachik arc volcano ( Litasov 2019) also Litasov responseGondwana Research, in press availableRussiaKamchatka
DS202005-0747
2020
Yang, J.Lin, J-F., Mao, Z., Yang, J., Fu, S.Elasticity of lower-mantle bridgmanite.Nature, Vol. 564, 7736, doi:10.1038/s41586-018-0741-7Mantlebridgmanite
DS202005-0773
2020
Yang, J.Yang, J., Faccenda, M.Intraplate volcanism originating from upwelling hydrous mantle transition zone.Nature, Vol. 579, 7797, pp. 1-4. pdfMantlewater, volcanism

Abstract: Most magmatism occurring on Earth is conventionally attributed to passive mantle upwelling at mid-ocean ridges, to slab devolatilization at subduction zones, or to mantle plumes. However, the widespread Cenozoic intraplate volcanism in northeast China1,2,3 and the young petit-spot volcanoes4,5,6,7 offshore of the Japan Trench cannot readily be associated with any of these mechanisms. In addition, the mantle beneath these types of volcanism is characterized by zones of anomalously low seismic velocity above and below the transition zone8,9,10,11,12 (a mantle level located at depths between 410 and 660 kilometres). A comprehensive interpretation of these phenomena is lacking. Here we show that most (or possibly all) of the intraplate and petit-spot volcanism and low-velocity zones around the Japanese subduction zone can be explained by the Cenozoic interaction of the subducting Pacific slab with a hydrous mantle transition zone. Numerical modelling indicates that 0.2 to 0.3 weight per cent of water dissolved in mantle minerals that are driven out from the transition zone in response to subduction and retreat of a tectonic plate is sufficient to reproduce the observations. This suggests that a critical amount of water may have accumulated in the transition zone around this subduction zone, as well as in others of the Tethyan tectonic belt13 that are characterized by intraplate or petit-spot volcanism and low-velocity zones in the underlying mantle.
DS200612-0838
2006
Yang, J.H.Lu, X.P., Wu, F.Y., Guo, J.H., Wilde, S.A., Yang, J.H., Liu, X.M., Zhang, XoZircon U Pb geochronological constraints on the Paleoproterozoic crustal evolution of the Eastern Block in the North Chin a Craton.Precambrian Research, Vol. 146, 3-4, pp. 138-164.ChinaGeochronology
DS200912-0436
2009
Yang, J.H.Li, Q.L., Li, X.H., Wu, F.Y., Yang, J.H.SIMS U-Th-Pb dating of kimberlite perovskite.Goldschmidt Conference 2009, p. A755 Abstract.Africa, South AfricaDeposit - Wesselton
DS1999-0817
1999
Yang, J.J.Yang, J.J., Jahn, B.M.Sinking intrusion model for the emplacement of garnet bearing peridotites into continent collision orogens...Geology, Vol. 27, No. 8, Aug. pp. 767-8.MantleSubduction, Petrology - peridotites
DS2000-1038
2000
Yang, J.J.Yang, J.J., Jahn, B.M.Deep subduction of mantle derived garnet peridotites from Su Lu ultra high pressure metamorphic terrane in China.Igc 30th. Brasil, Aug. abstract only 1p.Chinaultra high pressure (UHP) metamorphism
DS2003-0641
2003
Yang, J.J.Jahn, B., Fan, Q., Yang, J.J., Henin, O.Petrogenesis of the Maowu pyroxenite eclogite body from the UHP metamorphicLithos, Vol. 70, 3-4, pp. 243-67.ChinaUHP, geochronology
DS2003-1517
2003
Yang, J.J.Yang, J.J.Relict edenite in a garnet lherzolite from the Chinese Su Lu UHP metamorphic terrane:American Mineralogist, Vol.88, pp. 180-88.ChinaUHP - ultrahigh metamorphism
DS2003-1518
2003
Yang, J.J.Yang, J.J.Titanium clinohumite garnet pyroxene rock from the Su Lu UHP metamorphic terraneLithos, Vol. 70, 3-4, pp. 359-79.ChinaUHP, eclogites, metamorphism
DS2003-1519
2003
Yang, J.J.Yang, J.J., Enami, M.Chromian dissakisite ( Ce) in a garnet lherzolite from the Chinese Su Lu UHPAmerican Mineralogist, Vol. 88, 4, April, pp. 604-10.China, MantleUHP - ultra high pressure, REE
DS200412-0898
2003
Yang, J.J.Jahn, B., Fan, Q., Yang, J.J., Henin, O.Petrogenesis of the Maowu pyroxenite eclogite body from the UHP metamorphic terrane of Dabie Shan: chemical and isotopic constraLithos, Vol. 70, 3-4, pp. 243-67.ChinaUHP, geochronology
DS200412-2170
2003
Yang, J.J.Yang, J.J.Titanium clinohumite garnet pyroxene rock from the Su Lu UHP metamorphic terrane China: chemical evolution and tectonic implicatLithos, Vol. 70, 3-4, pp. 359-79.ChinaUHP, eclogites, metamorphism
DS200812-1291
2008
Yang, J.J.Yang, J.J., Powell, R.Ultrahigh pressure garnet peridotites from the devolatization of sea floor hydrated ultramafic rocks.Journal of Metamorphic Geology, Vol. 26, 6, pp. 695-716.ChinaQaidiam - peridotites
DS2003-1314
2003
Yang, J.S.Song, S.G., Yang, J.S., Xu, ZQ, Shi, R.D.Metamorphic evolution of the coesite bearing ultrahigh pressure terrane in the NorthJournal of Metamorphic Geology, Vol. 21, 6, pp. 631-44.ChinaUHP
DS2003-1547
2003
Yang, J.S.Zhang, R.Y., Liou, J.G., Yang, J.S., Ye, K.Ultrahigh pressure metamorphism in the forbidden zone: the Xugou garnet peridotiteJournal of Metamorphic Geology, Vol. 21, 6, pp. 539-50.ChinaUHP
DS200412-1880
2003
Yang, J.S.Song, S.G., Yang, J.S., Xu, ZQ, Shi, R.D.Metamorphic evolution of the coesite bearing ultrahigh pressure terrane in the North Qaidam northern Tibet, NW China.Journal of Metamorphic Geology, Vol. 21, 6, pp. 631-44.ChinaUHP
DS200412-2207
2003
Yang, J.S.Zhang, R.Y., Liou, J.G., Yang, J.S., Ye, K.Ultrahigh pressure metamorphism in the forbidden zone: the Xugou garnet peridotite.Journal of Metamorphic Geology, Vol. 21, 6, pp. 539-50.ChinaUHP
DS200512-1243
2005
Yang, J.S.Zhang, J.X., Yang, J.S., Mattison, C.G., Xu, Z.Q., Meng, F.C., Shi, R.D.Two contrasting eclogite cooling histories, north Qaidam HP/UHP terrane, western China: petrological and isotopic constraints.Lithos, Vol. 84, 1-2, Sept. pp. 51-76.ChinaEclogite, UHP, geochronology
DS200512-1246
2004
Yang, J.S.Zhang, R.Y., Liou, J.G., Yang, J.S., Liu, L., Jahn, B-M.Garnet peridotites in the UHP Mountain Belts of China.International Geology Review, Vol. 46, 11, pp. 981-1004.China, AsiaUHP
DS200512-1248
2005
Yang, J.S.Zhang, R.Y., Yang, J.S., Wooden, J.L., Liou, J.G., Li, T.F.U Pb SHRIMP geochronology of zircon in garnet peridotite from the Sulu UHP terrane, China: implications for mantle metasomatism and subduction.Earth and Planetary Science Letters, Vol. 237, 3-4, Sept. 15, pp. 729-743.Asia, ChinaUHP metamorphism, geochronology
DS200612-1604
2006
Yang, J.S.Zheng, J., Griffin, W.L., O'Reilly, S.Y., Yang, J.S., Zhang, R.Y.A refractory mantle protolith in younger continental crust, east central China: age and composition of zircon in Sulu ultrahigh pressure peridotite.Geology, Vol. 34, 9, Sept. pp. 705-708.ChinaUHP, geochronology
DS200712-1228
2007
Yang, J.S.Zhang, R.Y., Li, T., Rumble, D., Yui, T-F., Li, L., Yang, J.S., Pan, Y., Liou, J.G.Multiple metasomatism in Sulu ultrahigh P garnet peridotite constrained by petrological geochemiscal investigations.Journal of Metamorphic Geology, Vol. 25, 2, pp. 149-164..ChinaUHP
DS200812-0659
2008
Yang, J.S.Li, T.F., Yang, J.S., Zhang, R.Y.Geochemical characteristics, UHP metamorphic age, and genesis of the Huijialing garnet clinopyroxenite, Sulu terrane, China.International Geology Review, Vol. 50, 1, pp. 48-60.ChinaUHP
DS200812-1312
2008
Yang, J.S.Zhang, R.Y., Pan, Y.M., Yang, Y.H., Li, T.F., Liou, J.G., Yang, J.S.Chemical composition and ultrahigh P metamorphism of garnet peridotites from the Sulu UHP terrane, China: investigation of major, trace elements and Hf isotopesChemical Geology, in press available,ChinaUHP
DS200812-1313
2008
Yang, J.S.Zhang, R.Y., Pan, Y.M., Yang, Y.H., Li, T.F., Liou, J.G., Yang, J.S.Chemical composition and ultrahigh P metamorphism of garnet peridotites from the Sulu UHP terrane, China: investigation of major trace elements and Hf isotopes.Chemical Geology, Vol. 255, 1-2, Sept. 30, pp. 250-264.ChinaUHP
DS201112-1132
2011
Yang, J.S.Yang, J.S., Robinson, P.T.In situ diamonds and moissanite in podiform chromitites of the Loubusa and Ray-Iz ophiolites, Tibet and Russia.Goldschmidt Conference 2011, abstract p.2209.Russia, Asia, TibetDiamonds
DS201312-0337
2013
Yang, J.S.Griffin, W.L., Yang, J.S., Robinson, P., Howell, D., Shi, R., O'Reilly, S.Y., Pearson, D.J.Diamonds and super reducing UHP assemblages in ophiolitic mantle, Tibet: where are the eclogites?X International Eclogite Conference, 1p. abstractAsia, TibetDiamond genesis
DS201601-0051
2015
Yang, J.S.Yang, J.S., Wirth, R., Wiedenbeck, M., Griffin, W.L., Meng, F.C., Chen, S.Y., Bai, W.J., Xu, X.X., Makeeyev, A.B., Bryanchaniniova, N.I.Diamonds and highly reduced minerals from chromitite of the Ray-Iz ophiolite of the Polar Urals: deep origin of podiform chromitites and ophiolitic diamonds.Acta Geologica Sinica, Vol. 89, 2, p. 107.Russia, Polar UralsOphiolite
DS201810-2390
2018
Yang, J.S.Yang, J.S., Trumball, R.B., Robinson, P.T., Xiong, F.H., Lian, D.Y.Comment: Ultra high pressure and ultra reduced minerals in ophiolites may form by lightning strikes. Super Reduced Minerals SURGeochemical Perspectives Letters, Vol. 8, pp. 6-7.Mantlemoissanite
DS202006-0959
2020
Yang, J.W.Yang, J.W., Park, J.H., Byun, M.G., Park, J., Yu, B.D., Hwan, N.M.Beyond carbon solvency effects of catalytic metal Ni on diamond growth.Diamonds & Related Materials, in press available, 27p. PdfGlobalnitrogen

Abstract: To understand the physical and chemical roles of catalytic metal Ni in the growth of diamond, ab-initio calculations of the structural, electronic, and kinetic properties of a Ni-covered C (111) surface were performed. Findings from this theoretical study highlight two important roles of Ni in addition to its carbon-solvency effect, widely known to play a catalytic role in the growth of diamond. The first role is to facilitate the formation of a thermodynamically stable Ni-C interface with a diamond bulk-like structure and the second is to induce surfactant-mediated growth enabling continuous layer-by-layer growth for diamond.
DS200712-1225
2007
Yang, J-F.Zhang, H-F., Nakamura, E., Sun, M., Kobayashi,K., Zhang, J., Yang, J-F., Tang, Y-J.Transformation of subcontinental lithospheric mantle through peridotite melt reaction: evidence from a highly fertile mantle xenolith from the North Chin a Craton.International Geology Review, Vol. 49, 7, July pp. 658-679.ChinaMelting
DS200612-1547
2006
Yang, J-H.Wu, F-Y., Walker, R.J., Yang, Y-H., Yuan, H-L., Yang, J-H.The chemical temporal evolution of lithospheric mantle underlying the North Chin a Craton.Geochimica et Cosmochimica Acta, Vol. 70, 19, pp. 5013-5034.ChinaDeposit - Tieling, Fuxian, Mengyin - geochemistry -SCLM
DS200612-1548
2006
Yang, J-H.Wu, F-Y., Yang, Y-H., Xie, L-W., Yang, J-H., Xu, P.Hf isotopic compositions of the standard zircons and baddeleyites used in U Pb geochronology.Chemical Geology, Vol. 234, 1-2, Oct 30, pp. 105-126.ChinaUHP, geochronology
DS200912-0836
2009
Yang, J-H.Yang, Y-H., Wu, F-Y., Wilde, S.A., Liu, X-M., Zhang, Y-B., Xie, L-W., Yang, J-H.In in situ perovskite Sr Nd isotopic constraints on the petrogenesis of the Ordovician Mengyin kimberlites in North Chin a craton.Chemical Geology, Vol. 264, 1-4, pp. 24-42.ChinaDeposit - Mengyin
DS201012-0861
2010
Yang, J-H.Wu, F.Y., Yang, Y-H., Mitchell, R.H., Li, J-H., Yang, J-H., Zhang, Y-B.In situ U Pb age determination and Nd isotopic analysis of perovskites from kimberlites in southern Africa and Somerset Island, Canada.Lithos, Vol. 115, pp. 205-222.Canada, Nunavut, Africa, South AfricaGeochronology
DS201212-0167
2012
Yang, J-H.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
DS201212-0834
2012
Yang, J-H.Zhu, R-X., Yang, J-H., Wu, F-Y.Timing of destruction of the North Chin a craton.Lithos, Vol. 149, pp. 51-60.ChinaSubduction
DS201412-0897
2014
Yang, J-H.Sun, J., Liu, C-Z., Tappe, S., Kostrovitsky, S.I., Wu, F-Y., Yakovlev, D., Yang, Y-H., Yang, J-H.Repeated kimberlite magmatism beneath Yakutia and its relationship to Siberian flood volcanism: insights from in situ U-Pb and Sr-Nd perovskite isotope analysis.Earth and Planetary Science Letters, Vol. 404, Oct. pp. 283-295.Russia, YakutiaKimberlite magmatism
DS201706-1114
2017
Yang, J-H.Zhu, Y-S., Yang, J-H., Sun- J-F., Wang, H.Zircon Hf-0 isotope evidence for recycled oceanic and continental crust in the sources of alkaline rocks.Geology, Vol. 45, 5, pp. 407-410.Mantlealkaline rocks
DS201709-2061
2017
Yang, J-H.Sun, J., Liu, C-Z., Kostrovisky, S.I., Wu, F-Y., Yang, J-H., Chu, Z., Yang, Y-H.Constraints from peridotites in the Obnazhennaya kimberlite.Goldschmidt Conference, abstract 1p.Russiadeposit - Obnazhennaya

Abstract: The characteristics of the sub-continental lithospheric mantle (SCLM) post-date the Siberian plume event (250 Ma) is still unclear; nearly all published data for mantle xenoliths are from a single kimberlite erupt before he Siberian plume (Udachnaya). We report major elements of the whole rock, trace elements data of clinopyroxene and Re-Os isotope and PGE concentration of mantle xenoliths from the Obnazhennaya kimberlite pipe (160 Ma). The Obnazhennaya mantle xenoliths, including spinel harzburgites, spinel dunites, spinel lherzolites, spinel-garnet lherzolite. The spinel harzburgites and dunites have refractory compositions, with 0.23-1.35 wt.% Al2O3, 0.41-3.11 wt.% CaO and 0.00-0.09 wt.% TiO2. Clinopyroxenes in harzburgites and dunites have lower Na2O but higher Cr2O3 contents. Modeling of the Y and Yb contents in clinopyroxenes indicates that the spinel harzburgites and dunites have been subjected to ca. 12-17% degrees of partial melting. The spinel harzburgites and dunites have 187Os/188Os of 0.11227-0.11637, giving a TRD age of 1.6-2.2 Ga. This suggests that old cratonic mantle still existed beneath the Obnazhennaya. In contrast, the lherzolites (both spinel- and spinel-garnet-) have more fertile compositions, containing 2.16-6.55 wt.% Al2O3, 2.91-7.55 wt.% CaO and 0.04-0.15 wt.% TiO2. Both spinel and spinelgarnet lherzolites have more radiogenic 187Os/188Os ratios (0.11931-0.17627), enriched P-PGEs. The higher Al2O3 and Os content and depleted IPGE character of these lherzolites suggest that they were not juvenile mantle accreted by Siberian mantle plume but the refertilized ancient mantle. Therefore, our result suggest that the cratonic mantle beneath the Obnazhennaya has not been replaced by juvenile mantle during the Siberian mantle plume.
DS201709-2062
2017
Yang, J-H.Sun, J., Liu, C-Z., Kostrovisky, S.I., Wu, F-Y., Yang, J-H., Chu, Z., Yang, Y-H.Composition of the lithospheric mantle in the northern Siberian craton: constraints from the peridotites in the Obnazhennaya kimberlite.Goldschmidt Conference, abstract 1p.Russia, Siberiadeposit - Obnazhennaya

Abstract: The characteristics of the sub-continental lithospheric mantle (SCLM) post-date the Siberian plume event (250 Ma) is still unclear; nearly all published data for mantle xenoliths are from a single kimberlite erupt before he Siberian plume (Udachnaya). We report major elements of the whole rock, trace elements data of clinopyroxene and Re-Os isotope and PGE concentration of mantle xenoliths from the Obnazhennaya kimberlite pipe (160 Ma). The Obnazhennaya mantle xenoliths, including spinel harzburgites, spinel dunites, spinel lherzolites, spinel-garnet lherzolite. The spinel harzburgites and dunites have refractory compositions, with 0.23-1.35 wt.% Al2O3, 0.41-3.11 wt.% CaO and 0.00-0.09 wt.% TiO2. Clinopyroxenes in harzburgites and dunites have lower Na2O but higher Cr2O3 contents. Modeling of the Y and Yb contents in clinopyroxenes indicates that the spinel harzburgites and dunites have been subjected to ca. 12-17% degrees of partial melting. The spinel harzburgites and dunites have 187Os/188Os of 0.11227-0.11637, giving a TRD age of 1.6-2.2 Ga. This suggests that old cratonic mantle still existed beneath the Obnazhennaya. In contrast, the lherzolites (both spinel- and spinel-garnet-) have more fertile compositions, containing 2.16-6.55 wt.% Al2O3, 2.91-7.55 wt.% CaO and 0.04-0.15 wt.% TiO2. Both spinel and spinelgarnet lherzolites have more radiogenic 187Os/188Os ratios (0.11931-0.17627), enriched P-PGEs. The higher Al2O3 and Os content and depleted IPGE character of these lherzolites suggest that they were not juvenile mantle accreted by Siberian mantle plume but the refertilized ancient mantle. Therefore, our result suggest that the cratonic mantle beneath the Obnazhennaya has not been replaced by juvenile mantle during the Siberian mantle plume.
DS201803-0488
2018
Yang, J-H.Yang, Y-H., Wu, F-Y., Yang, J-H., Mitchell, R.H., Zhao, Z-F., Xie, L-W., Huang, C., Ma, Q., Yang, M., Zhao, H.U-Pb age determination of schorlomite garnet by laser ablation inductively coupled plasma mass spectrometry. Magnet Cove, Fanshan, Ozernaya, Alno, Prairie LakeJournal of Analytical At. Spectrometry, Vol. 33, pp. 231-239.United States, Arkansas, China, Hebei, Russia, Kola Peninsula, Europe, Sweden, Canada, Ontariogeochronology

Abstract: We report the first U-Pb geochronological investigation of schorlomite garnet from carbonatite and alkaline complexes and demonstrate its applicability for U-Pb age determination using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) due to its relatively high U and Th abundances and negligible common Pb content. The comparative matrix effects of laser ablation of zircon and schorlomite are investigated and demonstrate the necessity of a suitable matrix-matched reference material for schorlomite geochronology. Laser-induced elemental fractional and instrumental mass discrimination were externally-corrected using an in house schorlomite reference material (WS20) for U-Pb geochronology. In order to validate the effectiveness and robustness of our analytical protocol, we demonstrate the veracity of U-Pb age determination for five schorlomite samples from: the Magnet Cove complex, Arkansas (USA); the Fanshan ultrapotassic complex, Hebei (China); the Ozernaya alkaline ultramafic complex, Kola Peninsula (Russia); the Alnö alkaline-rock carbonatite complex (Sweden); and the Prairie Lake carbonatite complex, Ontario (Canada). The schorlomite U-Pb ages range from 96 Ma to 1160 Ma, and are almost identical to ages determined from other accessory minerals in these complexes and support the reliability of our analytical protocol. Schorlomite garnet U-Pb geochronology is considered to be a promising new technique for understanding the genesis of carbonatites, alkaline rocks, and related rare-metal deposits.
DS201809-2119
2018
Yang, J-H.Zhu, Y-S., Yang, J-H., Wang, H., Wu, F-Y.A Paleoproterozoic basement beneath the Rangrim massif revealed by in situ U-Pb ages and Hf isotopes of xenocrystic zircons from Triassic kimberlites of the North Korea.Goldschmidt Conference, 1p. AbstractAsia, North Koreadeposit - Rangrim

Abstract: Zircon xenocrysts from the kimberlites offer a unique opportunity to identify the cryptic basement components hidden in the deep crust and thus to image lithospheric structure and crustal evolution. Zircon xenocrysts from the Triassic kimberlites, exposed in the Rangrim massif of North Korea, were selected for in situ U-Pb and Hf analyses. These zircon xenocrysts are all crust-derived. Their U-Pb age spectrum is characterized by one prominent age population at ca. 1.9-1.8 Ga without any Archean ages, indicating a Paleoproterozoic-dominated basement in the depth of the Rangrim massif. Archean basement should be very limited or absent at depth. This is different with the previous thought of the Rangrim massif being an Archean terrane. However, most of those Paleoproterozoic zircons display negative eHf(t) values (-9.7~+0.7) with the average Hf model age of 2.83 ± 0.09 Ga (2s), implying that protoliths of those zircons were not juvenile but derived from reworking of the pre-existed Archean basement. These observations argue for a strong crustal reworking event occurred in the Rangriam massif during Paleoproterozoic, which exhausted most of the preexisted Archean basement rocks and generated a large abundance of Paleoproterozoic rocks. The 1.9~1.8 Ga thermal event has been well documented in the adjacent Jiao- Liao-Ji orogenic belt of the North China Craton. Both of them are characterized by the widely distributed 1.9~1.8 Ga magmatism and share similar igneous rock assemblage. We suggest that the Rangrim massif may be the eastern extension of the Jiao-Liao-Ji belt in North Korea, constituting part of a huge Paleoproterozoic orogen in the eastern margin of the Sino-Korean craton.
DS201902-0336
2019
Yang, J-H.Zhu, Y-S., Yang, J-H., Wang, H., Wu, F-Y.A Paleoproterozoic basement beneath the Rangnim Massif revealed by the in-situ U-Pb ages and Hf isotopes of xenocrystic zircons from the Triassic kimberlites of North Korea.Geological Magazine, on line available Asia, Koreakimberlites

Abstract: In situ U-Pb and Hf analyses were used for crustal zircon xenocrysts from Triassic kimberlites exposed in the Rangnim Massif of North Korea to identify components of the basement hidden in the deep crust of the Rangnim Massif and to clarify the crustal evolution of the massif. The U-Pb age spectrum of the zircons has a prominent population at 1.9-1.8 Ga and a lack of Archaean ages. The data indicate that the deep crust and basement beneath the Rangnim Massif are predominantly of Palaeoproterozoic age, consistent with the ages of widely exposed Palaeoproterozoic granitic rocks. In situ zircon Hf isotope data show that most of the Palaeoproterozoic zircon xenocrysts have negative ?Hf ( t ) values (-9.7 to +0.7) with an average Hf model age of 2.86 ± 0.02 Ga (2 s ), which suggests that the Palaeoproterozoic basement was not juvenile but derived from the reworking of Archaean rocks. Considering the existence of Archaean remanent material in the Rangnim Massif and their juvenile features, a strong crustal reworking event is indicated at 1.9-1.8 Ga, during which time the pre-existing Archaean basement was exhausted and replaced by a newly formed Palaeoproterozoic basement. These features suggest that the Rangnim Massif constitutes the eastern extension of the Palaeoproterozoic Liao-Ji Belt of the North China Craton instead of the Archaean Liaonan Block as previously thought. A huge Palaeoproterozoic orogen may exist in the eastern margin of the Sino-Korean Craton.
DS201907-1585
2019
Yang, J-H.Wu, F-Y., Yang, J-H., Xu, Y-G., Wilde, S.A., Walker, R.J.Destruction of the North China craton in the Mesozoic.Annual Reviews of Earth and Planetary Sciences, Vol. 47, pp. 173-195.Chinacraton

Abstract: The North China Craton (NCC) was originally formed by the amalgamation of the eastern and western blocks along an orogenic belt at ~1.9 Ga. After cratonization, the NCC was essentially stable until the Mesozoic, when intense felsic magmatism and related mineralization, deformation, pull-apart basins, and exhumation of the deep crust widely occurred, indicative of destruction or decratonization. Accompanying this destruction was significant removal of the cratonic keel and lithospheric transformation, whereby the thick (~200 km) and refractory Archean lithosphere mantle was replaced by a thin (<80 km) juvenile one. The decratonization of the NCC was driven by flat slab subduction, followed by a rollback of the paleo-Pacific plate during the late Mesozoic. A global synthesis indicates that cratons are mainly destroyed by oceanic subduction, although mantle plumes might also trigger lithospheric thinning through thermal erosion. Widespread crust-derived felsic magmatism and large-scale ductile deformation can be regarded as petrological and structural indicators of craton destruction.
DS201911-2579
2019
Yang, J-H.Zhu, Y-S., Yang, J-H., Wang, H., Wu, F-Y.A paleoproterozoic basement beneath the Rangnim Massif revealed by the in situ U-Pb ages and Hf isotopes of xenocrystic zircons from Triassic kimberlites of North Korea.Geological Magazine, Vol. 156, 10, pp. 1657-1667.Asia, Koreakimberlites

Abstract: n situ U-Pb and Hf analyses were used for crustal zircon xenocrysts from Triassic kimberlites exposed in the Rangnim Massif of North Korea to identify components of the basement hidden in the deep crust of the Rangnim Massif and to clarify the crustal evolution of the massif. The U-Pb age spectrum of the zircons has a prominent population at 1.9-1.8 Ga and a lack of Archaean ages. The data indicate that the deep crust and basement beneath the Rangnim Massif are predominantly of Palaeoproterozoic age, consistent with the ages of widely exposed Palaeoproterozoic granitic rocks. In situ zircon Hf isotope data show that most of the Palaeoproterozoic zircon xenocrysts have negative ?Hf(t) values (-9.7 to +0.7) with an average Hf model age of 2.86 ± 0.02 Ga (2s), which suggests that the Palaeoproterozoic basement was not juvenile but derived from the reworking of Archaean rocks. Considering the existence of Archaean remanent material in the Rangnim Massif and their juvenile features, a strong crustal reworking event is indicated at 1.9-1.8 Ga, during which time the pre-existing Archaean basement was exhausted and replaced by a newly formed Palaeoproterozoic basement. These features suggest that the Rangnim Massif constitutes the eastern extension of the Palaeoproterozoic Liao-Ji Belt of the North China Craton instead of the Archaean Liaonan Block as previously thought. A huge Palaeoproterozoic orogen may exist in the eastern margin of the Sino-Korean Craton.
DS201912-2835
2019
Yang, J-H.Yang, Y-H., Wu, F-Y., Qiu-Li, L., Rojas-Agramonte, Y., Yang, J-H., Yang, L., Ma, Q., Xie, L-W., Huang, C., Fan, H-R., Zhao, Z-F., Xu, C.In situ U-Th-Pb dating and Sr-Nd isotope analysis of bastnasite by LA-(MC)-ICP-MS.Geostandards and Geoanalltical Research, Vol. 43, 3, pp. 543-565.China, Europe, Sweden, Asia, Mongolia, United States, Africa, Malawi, MadagascarREE

Abstract: Bastnäsite is the end member of a large group of carbonate-fluoride minerals with the common formula (REE) CO3F•CaCO3. This group is generally widespread and, despite never occurring in large quantities, represents the major economic light rare earth element (LREE) mineral in deposits related to carbonatite and alkaline intrusions. Since bastnäsite is easily altered and commonly contains inclusions of earlier-crystallised minerals, in situ analysis is considered the most suitable method to measure its U-Th-Pb and Sr-Nd isotopic compositions. Electron probe microanalysis and laser ablation (multi-collector) inductively coupled plasma-mass spectrometry of forty-six bastnäsite samples from LREE deposits in China, Pakistan, Sweden, Mongolia, USA, Malawi and Madagascar indicate that this mineral typically has high Th and LREE and moderate U and Sr contents. Analysis of an in-house bastnäsite reference material (K-9) demonstrated that precise and accurate U-Th-Pb ages could be obtained after common Pb correction. Moreover, the Th-Pb age with its high precision is preferable to the U-Pb age because most bastnäsites have relatively high Th rather than U contents. These results will have significant implications for understanding the genesis of endogenous ore deposits and formation processes related to metallogenic geochronology research.
DS2003-1520
2003
Yang, J-J.Yang, J-J., Enami, M.Chromian dissakisite (Ce) in a garnet lherzolite from the Chinese Su-Lu UHPAmerican Mineralogist, Vol. 88, pp. 604-10.ChinaUHP, Su-Lu Zhimafang
DS2003-1560
2003
Yang, J-J.Zheng, Y-F., Yang, J-J., Gong, B., Jahn, B-M.Partial equilibrium of radiogenic and stable isotope systems in garnet peridotite duringAmerican Mineralogist, Vol. 88, pp. 1633-43.ChinaGeochronology, UHP
DS200412-2171
2003
Yang, J-J.Yang, J-J., Enami, M.Chromian dissakisite (Ce) in a garnet lherzolite from the Chinese Su-Lu UHP metamorphic terrane: implications for Cr incorporatiAmerican Mineralogist, Vol. 88, pp. 604-10.ChinaUHP, Su-Lu Zhimafang
DS200412-2227
2003
Yang, J-J.Zheng, Y-F., Yang, J-J., Gong, B., Jahn, B-M.Partial equilibrium of radiogenic and stable isotope systems in garnet peridotite during ultrahigh pressure metamorphism.American Mineralogist, Vol. 88, pp. 1633-43.ChinaGeochronology, UHP, Shimafang, Sulu
DS200612-1563
2006
Yang, J-J.Yang, J-J.Ca rich garnet clinopyroxene rocks at Hujialin in the Su Lu terrane (eastern China): deeply subducted arc cumulates?Journal of Petrology, Vol. 47, 5, pp. 965-990.Asia, ChinaUHP, subduction
DS201412-0382
2014
Yang, J-J.Huang, M-X., Yang, J-J., Powell, R., Mo, X.High pressure metamorphism of serpentinzed chromitite at Luobusha ( southern Tibet).American Journal of Science, Vol. 314, pp. 400-433.Asia, TibetDiamond and coesite
DS201412-1000
2014
Yang, J-J.Yang, J-J., Fan, Z.F., Yu, C., Yan, R.Coseismic formation of eclogite facies cataclastic dykes at Yangkou in the Chinese Sulu UHP metamorphic belt.Journal of Metamorphic Geology, Vol. 32, 9, pp. 937-960.ChinaUHP
DS201412-1001
2014
Yang, J-J.Yang, J-J., Huang, M-X., Wu, Q-Y., Zhang, H-R.Coesite bearing eclogite breccia: implication for coseismic ultrahigh-pressure metamorphism and the rate of process.Contributions to Mineralogy and Petrology, Vol. 167, pp. 1013-MantleEclogite
DS200712-1198
2007
Yang, J-S.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
DS200912-0776
2009
Yang, J-S.Trumball, R.B., Yang, J-S., Robinson, P.T., Di Pierro, S., Vennemann, T., Wiedenbeck, M.The carbon isotope composition of natural SiC (moissanite) from the Earth's mantle: new discoveries from ophiolites.Lithos, In press - available 31p.MantleMoissanite
DS201112-0871
2004
Yang, J-S.Robinson, P.T., Bai, W-J., Malpas, J., Yang, J-S., Zhou, M-F., Fang, Q-S., Hu, X-F., Cameron, StaudigelUltra high pressure minerals in the Loubasa ophiolite, Tibet and their tectonic implications.Aspects of the Tectonic evolution of China, Editors Fletcher, Ali, Aitchison, Geological Society Of America, Spec. Pub.226, pp.247-71China, TibetUHP
DS201502-0093
2014
Yang, J-S.Robinson, P.T., Trumbull, R.B., Schmitt, A., Yang, J-S., Li, J-W., Zhou, M-F., Erzinger, J., Dare, S., Xiong, F.The origin and significance of crustal minerals in ophiolitic chromitites and peridotites.Gondwana Research, Vol. 27 2, pp. 486-506.Peridotite
DS201510-1816
2015
Yang, J-S.Yang, J-S., Wirth, R., Xu, X., Tian, Y., Huang, Z., Robinson, P.T., Dilek, Y.Formation of ophiolite hosted diamonds by deep subduction of oceanic lithosphere: evidence from mineral inclusions.GSA Annual Meeting, Paper 81-2, 1p. Abstract onlyMantleMineral inclusions

Abstract: In recent years we have confirmed the existence of ophiolite-hosted diamonds on Earth, which occur in mantle peridotites and podiform chromitites of many ophiolites. These diamonds differ significantly from most kimberlite varieties, particularly in their inclusions. The typical inclusions in the diamonds are Mn-rich phases, i.e., NiMnCo alloy, native Mn, MnO, galaxite, Mn olivine and Mn garnet. Ca-silicate perovskite, a typical lower mantle mineral, was identified as mineral inclusions in diamond. One occurs as a 60-nanometer, euhedral grain associated with NiMnCo alloy and graphite, while another one occurs as a 50-nanometer grain within a large inclusion containing both NiMnCo alloy and Nd-Se-Cu-S phase. By EDS the perovskite has Ca 48.3%, Si 37.7% and Mn 14.1% with oxygen. TEM diffraction data show that the inclusion has d-spacings and angles between adjacent lattice planes are consistent to the Ca-silicate perovskite with an orthorhombic structure. The only known source of such light carbon is organic material in surface sediments and the best known sources of abundant manganese are Fe-Mn-rich sediments and Mn nodules, both of which are common on the seafloor. Many parts of the modern seafloor are also covered by sediments with a continental provenance. Phases such as SiO2 and Al2O3 are not expected in mantle peridotites and must have been introduced from shallow levels. We propose that subduction of oceanic lithosphere carries C, Mn, Si, Al and REE to the transition zone or lower mantle where the material is mixed with highly reduced material, perhaps derived from greater depths. Crystallization of diamond from a C-rich fluid encapsulates the observed inclusions. The diamonds and associated minerals are incorporated into chromite grains during chromite crystallization at depth of mantle transition zone, and are carried to shallower levels by mantle convection. Accumulation of chromite grains produces podiform chromitites containing a range of exotic minerals. However, the presence of diamonds and other UHP minerals in ophiolitic peridotites indicates that such phases can persist far outside their normal stability fields.
DS201606-1090
2016
Yang, J-S.Griffin, W.L., Afonso, J.C., Belousova, E.A., Gain, S.E., Gong, X-H., Gonzalez-Jiminez, J.M., Howell, D., Huang, J-X., McGowan, N., Pearson, N.J., Satsukawa, T., Shi R., Williams, P., Xiong, Q., Yang, J-S., Zhang, M., O'Reilly, S.Y.Mantle recycling: transition zone metamorphism of Tibetan ophiolitic peridotites and its tectonic implications.Journal of Petrology, in press available, 30p.Asia, China, TibetPeridotite

Abstract: Large peridotite massifs are scattered along the 1500?km length of the Yarlung-Zangbo Suture Zone (southern Tibet, China), the major suture between Asia and Greater India. Diamonds occur in the peridotites and chromitites of several massifs, together with an extensive suite of trace phases that indicate extremely low fO2 (SiC, nitrides, carbides, native elements) and/or ultrahigh pressures (UHP) (diamond, TiO2 II, coesite, possible stishovite). New physical and isotopic (C, N) studies of the diamonds indicate that they are natural, crystallized in a disequilibrium, high-T environment, and spent only a short time at mantle temperatures before exhumation and cooling. These constraints are difficult to reconcile with previous models for the history of the diamond-bearing rocks. Possible evidence for metamorphism in or near the upper part of the Transition Zone includes the following: (1) chromite (in disseminated, nodular and massive chromitites) containing exsolved pyroxenes and coesite, suggesting inversion from a high-P polymorph of chromite; (2) microstructural studies suggesting that the chromitites recrystallized from fine-grained, highly deformed mixtures of wadsleyite and an octahedral polymorph of chromite; (3) a new cubic Mg-silicate, with the space group of ringwoodite but an inverse-spinel structure (all Si in octahedral coordination); (4) harzburgites with coarsely vermicular symplectites of opx + Cr-Al spinel ± cpx; reconstructions suggest that these are the breakdown products of majoritic garnets, with estimated minimum pressures to?>?13?GPa. Evidence for a shallow pre-metamorphic origin for the chromitites and peridotites includes the following: (1) trace-element data showing that the chromitites are typical of suprasubduction-zone (SSZ) chromitites formed by magma mixing or mingling, consistent with Hf-isotope data from magmatic (375?Ma) zircons in the chromitites; (2) the composition of the new cubic Mg-silicate, which suggests a low-P origin as antigorite, subsequently dehydrated; (3) the peridotites themselves, which carry the trace element signature of metasomatism in an SSZ environment, a signature that must have been imposed before the incorporation of the UHP and low-fO2 phases. A proposed P-T-t path involves the original formation of chromitites in mantle-wedge harzburgites, subduction of these harzburgites at c. 375?Ma, residence in the upper Transition Zone for >200 Myr, and rapid exhumation at c. 170-150?Ma or 130-120?Ma. Os-isotope data suggest that the subducted mantle consisted of previously depleted subcontinental lithosphere, dragged down by a subducting oceanic slab. Thermomechanical modeling shows that roll-back of a (much later) subducting slab would produce a high-velocity channelized upwelling that could exhume the buoyant harzburgites (and their chromitites) from the Transition Zone in?
DS201705-0858
2017
Yang, J-S.Moe, K., Yang, J-S., Johnson, P., Wang, W.Spectroscopic analysis of microdiamonds in ophiolitic chromitite and peridotite.Lithosphere, 9p.Asia, Tibet, Russia, UralsMicrodiamonds

Abstract: Microdiamonds ~200 µm in size, occurring in ophiolitic chromitites and peridotites, have been reported in recent years. Owing to their unusual geological formation, there are several debates about their origin. We studied 30 microdiamonds from 3 sources: (1) chromitite ore in Luobusa, Tibet; (2) peridotite in Luobusa, Tibet; and (3) chromitite ore in Ray-Iz, polar Ural Mountains, Russia. They are translucent, yellow to greenish-yellow diamonds with a cubo-octahedral polycrystalline or single crystal with partial cubo-octahedral form. Infrared (IR) spectra revealed that these diamonds are type Ib (i.e., diamonds containing neutrally charged single substitutional nitrogen atoms, Ns0, known as the C center) with unknown broad bands observed in the one-phonon region. They contain fluid inclusions, such as water, carbonates, silicates, hydrocarbons, and solid CO2. We also identified additional microinclusions, such as chromite, magnetite, feldspar (albite), moissanite, hematite, and magnesiochromite, using a Raman microscope. Photoluminescence (PL) spectra measured at liquid nitrogen temperature suggest that these diamonds contain nitrogen-vacancy, nickel, and H2 center defects. We compare them with high-pressure-high-temperature (HPHT) synthetic industrial diamond grits. Although there are similarities between microdiamonds and HPHT synthetic diamonds, major differences in the IR, Raman, and PL spectra confirm that these microdiamonds are of natural origin. Spectral characteristics suggest that their geological formation is different but unique compared to that of natural gem-quality diamonds. Although these microdiamonds are not commercially important, they are geologically important in that they provide an understanding of a new diamond genesis.
DS2000-0602
2000
Yang, K.Ma, C., Ehlers, C., Xu, C., Li, Z., Yang, K.The roots of the Dabie Shan ultrahigh pressure metamorphic terrane: constraints from geochemistry ...Precambrian Research, Vol. 102, No. 3-4, Aug.pp. 279-301.Chinaultra high pressure (UHP), geochronology, Dabie Shan region
DS200712-1153
2007
Yang, K.White, N.C., Yang, K.Exploring in China: the challenges and rewards.SEG Newsletter, No.70, July pp. 1, 8-15.ChinaOverview - not specific to diamonds
DS201112-1100
2011
Yang, K.Wang, K., Fan, H., Yang, K., Hu, F., Ma, Y.Bayan Obo carbonatites: texture evidence from polyphase intrusive and extrusive carbonatites.Acta Geologica Sinica, Vol. 84, 6, pp. 1365-1376.Asia, ChinaCarbonatite
DS202001-0047
2020
Yang, K.Wang, X., Xiao, Y., Sun, Y., Wang, Y., Liu, J., Yang, K., Gu, H., Hou, Z., Tian, Y., Wu, W., Ma, Y.Initiation of the North China craton destruction: constraints from the diamond bearing alkaline basalts from Langan, China.Gondwana Research, Vol. 80, pp. 228-243.Chinacraton

Abstract: The North China Craton (NCC) is an atypical ancient landmass that suffered lithospheric destruction. Previous studies suggest that the eastern part of the lithospheric mantle of the NCC has been thinned and modified in the Mesozoic. However, the initiation time and mechanism of the destruction remain controversial. Mafic magmatismcould provide a unique windowinto deciphering the lithospheric mantle composition and its evolution. Here we present geochemical and geochronological data of the diamond-bearing alkaline basalts from Lan'gan, located in the southeastern margin of the NCC. Zircon U-Pb dating yielded an average age of 174 ± 14 Ma, representing the first reported Jurassic basalts in the eastern NCC. The Lan'gan basalts are enriched in light rare earth elements (LREE) and large ion lithosphile elements (LILE). Sr-Nd-Pb-Hf isotopic compositions (87Sr/86Sr(t) = 0.70646-0.70925, eNd(t) = -2.1 to -4.9, 206Pb/204Pb(t) = 17.14-18.12, 207Pb/204Pb(t) = 15.28-15.61, 208Pb/204Pb(t) = 37.82-38.67, and zircon eHf(t) = -17 to -21) are enriched compared to depleted mantle. The presence of primary amphibole indicates that the magma source of the basalts was water enriched. These observations suggest that, the lithospheric mantle of the eastern NCC were significantly refertilized, likely by slab derived fluids/melts fromthe Paleo-Pacific subduction. Owing to the Paleo-Pacific subduction, the lithosphericmantle of the eastern NCCwere reduced in viscosity and intensity, and finally promoted partialmelting in a limited scale to generate the investigated alkaline basalts. Hence, the discovery of diamond in the Lan'gan basalts demonstrates that the lithosphere of the NCC remained thick, and that large-scale destruction had not initiated in the early Jurassic beneath this region.
DS202004-0542
2020
Yang, K.Wang, X., Xiao, Y., Wang, Y., Liu, J., Yang, K., Gu, H., Hou, Z., Tian, Y., Wu, W., Ma, Y.Initiation of the North China Craton destruction: constraints from the diamond bearing alkaline basalts from Langan China.Gondwana Research, Vol. 80, pp. 228-243.Chinadeposit - Langan

Abstract: The North China Craton (NCC) is an atypical ancient landmass that suffered lithospheric destruction. Previous studies suggest that the eastern part of the lithospheric mantle of the NCC has been thinned and refertilized in the Mesozoic. However, the initiation time and mechanism of the destruction remain controversial. Mafic magmatism could provide a unique window into deciphering the lithospheric mantle composition and its evolution. Here we present geochemical and geochronological data of the diamond-bearing alkaline basalts from Lan'gan, located in the southeastern margin of the NCC. Zircon UPb dating yielded an average age of 174?±?14?Ma, representing the first reported Jurassic basalts in the eastern NCC. The Lan'gan basalts are enriched in light rare earth elements (LREE) and large ion lithosphile elements (LILE). Sr-Nd-Pb-Hf isotopic compositions (87Sr/86Sr(t)?=?0.70646-0.70925, eNd(t)?=?-2.1 to -4.9, 206Pb/204Pb(t)?=?17.14-18.12, 207Pb/204Pb(t)?=?15.28-15.61, 208Pb/204Pb(t)?=?37.82-38.67, and zircon eHf(t)?=?-17 to -21) are slightly enriched compared to depleted mantle. The presence of primary amphibole indicates that the magma source of the basalts was water enriched. These observations suggest that, the lithospheric mantle of the eastern NCC were significantly refertilized, likely by slab derived fluids/melts from the Paleo-Pacific subduction. Owing to the Paleo-Pacific subduction, the lithospheric mantle of the eastern NCC were reduced in viscosity and intensity, and finally promoted partial melting in a limited scale to generate the investigated alkaline basalts. Hence, the discovery of diamond in the Lan'gan basalts demonstrates that the lithosphere of the NCC remained thick, and that large-scale destruction had not initiated in the early Jurassic beneath this region.
DS201112-1134
2011
Yang, K-F.Yang, K-F., Fan, H-R., Santosh, M., Hu, F-F., Wang, K-Y.Mesoproterozoic mafic and carbonatitic dykes from the northern margin of the North Chin a craton: implications for the fin al breakup of Columbia supercontinent.Tectonophysics, Vol. 498, pp. 1-10.ChinaCarbonatite, Bayan Obo
DS201412-0236
2014
Yang, K-F.Fan, H-R., Hu, F-F., Yang, K-F., Pirajno, F., Liu, X., Wang, K-Y.Integrated U-Pb and Sm-Nd geochronology for a REE rich carbonatite dyke at the giant Bayan Obo REE deposit, northern China.Lithos, in press availableChinaDeposit - Bayan Obo
DS201412-0238
2014
Yang, K-F.Fan, H-R., Hu, F-F., Yang, K-F., Pirajno, F., Liu, X., Wang, K-Y.Integrated U Pb and Sm Nd geochronology of a REE rich carbonatite dyke at the gaint Bayan Obo REE deposit, northern China.Ore Geology Reviews, Vol. 63, pp. 510-519.ChinaCarbonatite
DS202010-1857
2020
Yang, K-F.Liu, S., Ding, L., Fan, H-R., Yang, K-F., Tang, Y-W. She, H-D, Hao, M-z.Hydrothermal genesis of Nb mineralization in the giant Bayan Obo REE-Nb-Fe deposit ( China): implicated by petrography and geochemistry of Nb-bearing minerals.Precambrian Research, Vol. 348, 105864 24p. PdfChinadeposit - Bayan Obo

Abstract: The Bayan Obo REE-Nb-Fe deposit, which reserves the current largest REE resources globally, also hosts over 70% of China’s Nb resources. Unlike many world-class carbonatite-related Nb deposits (e.g. Morro dos Seis Lagos and Araxá, Brazil) with igneous or secondary origin, Nb was mainly stored in Nb-bearing minerals (aeschynite, ilmenorutile, baotite, fergusonite etc.) of hydrothermal origin at Bayan Obo, supported by evidence from petrography, element and isotopic geochemistry. Although igneous fersmite and columbite were occasionally discovered in local carbonatite dykes, the Mesoproterozoic and Paleozoic hydrothermal metasomatism occurred in the ore-hosting dolomite, related to carbonatite intrusion and the closure of Paleo-Asian Ocean respectively, has played a more significant role during the ultimate Nb enrichment. REE, however, was significantly enriched during both the carbonatite-related magmatic and hydrothermal processes. Consequently, there was differentiated mineralization between REE and Nb in the carbonatite dykes and the ores. Niobium mineralization at Bayan Obo is rather limited in Mesoproterozoic carbonatite, whereas more extensive in the metasomatized ore-hosting dolomite, and generally postdating the REE mineralization at the same stage. According to mineral geochemistry, Bayan Obo aeschynite was classified into 3 groups: aeschynite-(Nd) with convex REE patterns (Group 1); aeschynite-(Ce) (Group 2) and nioboaeschynite (Group 3) with nearly flat REE patterns. Aeschynite (Group 1), ilmenorutile and fergusonite precipitated from Paleozoic hydrothermal fluids with advanced fractionation of Ce-rich REE minerals. The Mesoproterozoic hydrothermal Nb mineralization, represented by aeschynite (Group 3) and baotite, occurred postdating REE mineralization at same stage. Besides, fersmite and aeschynite (Group 2) precipitated from the Mesoproterozoic REE-unfractionated melt and hydrothermal fluids, respectively. All above Nb-bearing minerals exhibit extreme Nb-Ta fractionation as a primary geochemical characteristic of mantle-derived carbonatite. The forming age of the aeschynite megacrysts (Group 1) has not been accurately determined. However, the potential age was constrained to ~430 Ma or alternatively ~270-280 Ma subjected to subduction and granite activity, respectively. These aeschynite crystals inherited REEs from multiphase former REE mineralization, with an intermediate apparent Sm-Nd isochron age between the Mesoproterozoic and the Paleozoic REE mineralization events.
DS202012-2254
2020
Yang, K-F.Wang, Z-Y., Fan, H-R., Zhou, L., Yang, K-F., She, H-D.Carbonatite-related REE deposits: an overview.MDPI Minerals, Vol. 10, 965 doi:103390/min10110965, 26p. PdfChinacarbonatite, REE

Abstract: The rare earth elements (REEs) have unique and diverse properties that make them function as an “industrial vitamin” and thus, many countries consider them as strategically important resources. China, responsible for more than 60% of the world’s REE production, is one of the REE-rich countries in the world. Most REE (especially light rare earth elements (LREE)) deposits are closely related to carbonatite in China. Such a type of deposit may also contain appreciable amounts of industrially critical metals, such as Nb, Th and Sc. According to the genesis, the carbonatite-related REE deposits can be divided into three types: primary magmatic type, hydrothermal type and carbonatite weathering-crust type. This paper provides an overview of the carbonatite-related endogenetic REE deposits, i.e., primary magmatic type and hydrothermal type. The carbonatite-related endogenetic REE deposits are mainly distributed in continental margin depression or rift belts, e.g., Bayan Obo REE-Nb-Fe deposit, and orogenic belts on the margin of craton such as the Miaoya Nb-REE deposit. The genesis of carbonatite-related endogenetic REE deposits is still debated. It is generally believed that the carbonatite magma is originated from the low-degree partial melting of the mantle. During the evolution process, the carbonatite rocks or dykes rich in REE were formed through the immiscibility of carbonate-silicate magma and fractional crystallization of carbonate minerals from carbonatite magma. The ore-forming elements are mainly sourced from primitive mantle, with possible contribution of crustal materials that carry a large amount of REE. In the magmatic-hydrothermal system, REEs migrate in the form of complexes, and precipitate corresponding to changes of temperature, pressure, pH and composition of the fluids. A simple magmatic evolution process cannot ensure massive enrichment of REE to economic values. Fractional crystallization of carbonate minerals and immiscibility of melts and hydrothermal fluids in the hydrothermal evolution stage play an important role in upgrading the REE mineralization. Future work of experimental petrology will be fundamental to understand the partitioning behaviors of REE in magmatic-hydrothermal system through simulation of the metallogenic geological environment. Applying "comparative metallogeny" methods to investigate both REE fertile and barren carbonatites will enhance the understanding of factors controlling the fertility.
DS201912-2799
2019
Yang, L.Liu, J., Hu, Q., Bi, W., Yang, L., Xiao, Y., Chow, P., Meng, Y., Prakapenka, V.B., Mao, H-K., Mao, W.L.Altered chemistry of oxygen and iron under deep Earth conditionsNature Communications, 8p. PdfMantlegeochemistry

Abstract: A drastically altered chemistry was recently discovered in the Fe-O-H system under deep Earth conditions, involving the formation of iron superoxide (FeO2Hx with x?=?0 to 1), but the puzzling crystal chemistry of this system at high pressures is largely unknown. Here we present evidence that despite the high O/Fe ratio in FeO2Hx, iron remains in the ferrous, spin-paired and non-magnetic state at 60-133?GPa, while the presence of hydrogen has minimal effects on the valence of iron. The reduced iron is accompanied by oxidized oxygen due to oxygen-oxygen interactions. The valence of oxygen is not -2 as in all other major mantle minerals, instead it varies around -1. This result indicates that like iron, oxygen may have multiple valence states in our planet’s interior. Our study suggests a possible change in the chemical paradigm of how oxygen, iron, and hydrogen behave under deep Earth conditions.
DS201912-2835
2019
Yang, L.Yang, Y-H., Wu, F-Y., Qiu-Li, L., Rojas-Agramonte, Y., Yang, J-H., Yang, L., Ma, Q., Xie, L-W., Huang, C., Fan, H-R., Zhao, Z-F., Xu, C.In situ U-Th-Pb dating and Sr-Nd isotope analysis of bastnasite by LA-(MC)-ICP-MS.Geostandards and Geoanalltical Research, Vol. 43, 3, pp. 543-565.China, Europe, Sweden, Asia, Mongolia, United States, Africa, Malawi, MadagascarREE

Abstract: Bastnäsite is the end member of a large group of carbonate-fluoride minerals with the common formula (REE) CO3F•CaCO3. This group is generally widespread and, despite never occurring in large quantities, represents the major economic light rare earth element (LREE) mineral in deposits related to carbonatite and alkaline intrusions. Since bastnäsite is easily altered and commonly contains inclusions of earlier-crystallised minerals, in situ analysis is considered the most suitable method to measure its U-Th-Pb and Sr-Nd isotopic compositions. Electron probe microanalysis and laser ablation (multi-collector) inductively coupled plasma-mass spectrometry of forty-six bastnäsite samples from LREE deposits in China, Pakistan, Sweden, Mongolia, USA, Malawi and Madagascar indicate that this mineral typically has high Th and LREE and moderate U and Sr contents. Analysis of an in-house bastnäsite reference material (K-9) demonstrated that precise and accurate U-Th-Pb ages could be obtained after common Pb correction. Moreover, the Th-Pb age with its high precision is preferable to the U-Pb age because most bastnäsites have relatively high Th rather than U contents. These results will have significant implications for understanding the genesis of endogenous ore deposits and formation processes related to metallogenic geochronology research.
DS200812-1235
2007
Yang, L-K.Wang, F., Lu, X-X., Lo, C-H., Wu, F-Y., He, H-Y., Yang, L-K., Zhu, R-X.Post collisional, potassic monzonite-minette complex Shahewan in the Qinling Mountains: 40Ar 39Ar thermochronology, petrogenesis, implications - dynamicJournal of Asian Earth Sciences, Vol. 31, 2, October pp. 153-166.ChinaMinette
DS201803-0488
2018
Yang, M.Yang, Y-H., Wu, F-Y., Yang, J-H., Mitchell, R.H., Zhao, Z-F., Xie, L-W., Huang, C., Ma, Q., Yang, M., Zhao, H.U-Pb age determination of schorlomite garnet by laser ablation inductively coupled plasma mass spectrometry. Magnet Cove, Fanshan, Ozernaya, Alno, Prairie LakeJournal of Analytical At. Spectrometry, Vol. 33, pp. 231-239.United States, Arkansas, China, Hebei, Russia, Kola Peninsula, Europe, Sweden, Canada, Ontariogeochronology

Abstract: We report the first U-Pb geochronological investigation of schorlomite garnet from carbonatite and alkaline complexes and demonstrate its applicability for U-Pb age determination using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) due to its relatively high U and Th abundances and negligible common Pb content. The comparative matrix effects of laser ablation of zircon and schorlomite are investigated and demonstrate the necessity of a suitable matrix-matched reference material for schorlomite geochronology. Laser-induced elemental fractional and instrumental mass discrimination were externally-corrected using an in house schorlomite reference material (WS20) for U-Pb geochronology. In order to validate the effectiveness and robustness of our analytical protocol, we demonstrate the veracity of U-Pb age determination for five schorlomite samples from: the Magnet Cove complex, Arkansas (USA); the Fanshan ultrapotassic complex, Hebei (China); the Ozernaya alkaline ultramafic complex, Kola Peninsula (Russia); the Alnö alkaline-rock carbonatite complex (Sweden); and the Prairie Lake carbonatite complex, Ontario (Canada). The schorlomite U-Pb ages range from 96 Ma to 1160 Ma, and are almost identical to ages determined from other accessory minerals in these complexes and support the reliability of our analytical protocol. Schorlomite garnet U-Pb geochronology is considered to be a promising new technique for understanding the genesis of carbonatites, alkaline rocks, and related rare-metal deposits.
DS1975-1268
1979
YANG, Meie.Zhang ruyuan, YANG, Meie.The Calculation Method of Composition of GarnetScientia Geol. Sinica., Vol. 15, No. 1, PP. 98-99.ChinaGarnet, Endmember Calculation, Element Ratios
DS200712-0882
2007
Yang, P.Reguir, E., Halden, N., Chakmouradian, A., Yang, P., Zaitsev, A.N.Contrasting evolutionary trends in magnetite from carbonatites and alkaline silicate rocks.Plates, Plumes, and Paradigms, 1p. abstract p. A826.Africa, TanzaniaCarbonatite
DS200812-0192
2008
Yang, P.Chakhmouradian, A.H., Bohm, C.O., Demeny, A., Reguir, E.P., Hegger, E., Halden, N.M., Yang, P.Kimberlite from Wekusko Lake, Manitoba: a diamond indicator bearing beforsite and not a kimberlite, after all.9IKC.com, 3p. extended abstractCanada, manitobaCarbonatite
DS200812-0194
2008
Yang, P.Chakhmouradian, A.R., Demeny, A., Reguir, E.P., Hegner, E., Halden, N.M., Yang, P.'Kimberlite' from Wekusko Lake, Manitoba: re-assessment and implications for further exploration. Beforsite ( primary dolomite carbonatite)... 'notion' could beManitoba Geological Survey, Nov. 21, 1p. abstract.Canada, ManitobaPetrology - potentially diamondiferous
DS200812-0946
2008
Yang, P.Reguir, E., Chakhmouradian, A., Halden, N., Malkovets, V., Yang, P.Major and trace element compositional variation of phlogopite from kimberlites and carbonatites as a petrogenetic indicator.9IKC.com, 3p. extended abstractCanada, AfricaGeochemistry - ferromagnesian micas
DS200812-0947
2008
Yang, P.Reguir, E.P., Chakhmouradian, A.R., Halden, N.M., Yang, P., Zaitsev, A.N.Early magmatic and reaction induced trends in magnetite from the carbonatites of Kerimasi, Tanzania.Canadian Mineralogist, Vol. 46, 4, August pp.Africa, TanzaniaCarbonatite
DS200912-0623
2009
Yang, P.Reguir, E.P., Chakmouradian, A.R., Halden, N.M., Malkovets, V.G., Yang, P.Major and trace element compositional variation of phlogopite from kimberlites and carbonatites as a petrogenetic indicator.Lithos, In press available, 50p.TechnologyGeochemistry - ferromagnesian micas
DS201012-0094
2009
Yang, P.Chakhmouradian, A.R., Bohm, C.O., Demeny, A., Reguir, E.P., Hegner, E., Creaser, R.A., Halden, N.M., Yang, P.'Kimberlite' from Wekusko Lake Manitoba: actually a diamond indicator bearing dolomite carbonatite.Lithos, Vol. 112 S pp. 347-357.Canada, ManitobaCarbonatite
DS201012-0619
2010
Yang, P.Reguir, E.P., Chakhmouradian, A.R., Halden, N.M., Yang, P.Trace element variations in clinopyroxene from calcite carbonatites.International Mineralogical Association meeting August Budapest, abstract p. 575.Canada, Ontario, Russia, Aldan Shield, Kola PeninsulaCarbonatite
DS201012-0620
2010
Yang, P.Reguir, E.P., Chakhmouradian, A.R., Halden, N.M., Yang, P.Contrasting trends of trace element zoning in phlogopite from calcite carbonatites.International Mineralogical Association meeting August Budapest, abstract p. 575.United States, Colorado Plateau, Russia, Canada, Ontario, QuebecCarbonatite
DS201312-0674
2013
Yang, P.Osovetskii, B.M., Reguir, E.P., Chakhmouradian, A.R., Veksler, I.V., Yang, P., Kamanetsky, V.S., Camacho, A.Trace element analysis and U-Pb geochronology of perovskite and its importance for tracking unexposed rare metal and diamond deposits.GAC-MAC 2013 SS4: Diamond: from birth to the mantle emplacement in kimberlite., abstract onlyMantleGeochronology
DS201412-0112
2014
Yang, P.Chakhmouradian, A.R., Reguir, E.P., Kressal, R.D., Crozier, J., Pisiak, L.K., Sidhu, R., Yang, P.Carbonatite hosted niobium deposit at Aley, northern British Columbia ( Canada): mineralogy, geochemistry and petrogenesis.Ore Geology Reviews, Vol. 64, pp. 642-666.Canada, British ColumbiaCarbonatite
DS201508-0344
2015
Yang, P.Chakhmouradian, A.R., Reguir, E.P., Coueslan, C., Yang, P.Calcite and dolomite in intrusive carbonatites. II Trace element variations.Mineralogy and Petrology, in press available 17p.GlobalCarbonatite

Abstract: The composition of calcite and dolomite from several carbonatite complexes (including a large set of petrographically diverse samples from the Aley complex in Canada) was studied by electron-microprobe analysis and laser-ablation inductively-coupled-plasma mass-spectrometry to identify the extent of substitution of rare-earth and other trace elements in these minerals and the effects of different igneous and postmagmatic processes on their composition. Analysis of the newly acquired and published data shows that the contents of rare-earth elements (REE) and certain REE ratios in magmatic calcite and dolomite are controlled by crystal fractionation of fluorapatite, monazite and, possibly, other minerals. Enrichment in REE observed in some samples (up to ~2000 ppm in calcite) cannot be accounted for by coupled substitutions involving Na, P or As. At Aley, the REE abundances and chondrite-normalized (La/Yb)cn ratios in carbonates decrease with progressive fractionation. Sequestration of heavy REE from carbonatitic magma by calcic garnet may be responsible for a steeply sloping "exponential" pattern and lowered Ce/Ce* ratios of calcite from Magnet Cove (USA) and other localities. Alternatively, the low levels of Ce and Mn in these samples could result from preferential removal of these elements by Ce4+- and Mn3+-bearing minerals (such as cerianite and spinels) at increasing f(O2) in the magma. The distribution of large-ion lithophile elements (LILE = Sr, Ba and Pb) in rock-forming carbonates also shows trends indicative of crystal fractionation effects (e.g., concomitant depletion in Ba + Pb at Aley, or Sr + Ba at Kerimasi), although the phases responsible for these variations cannot be identified unambiguously at present. Overall, element ratios sensitive to the redox state of the magma and its complexing characteristics (Eu/Eu*, Ce/Ce* and Y/Ho) are least variable and in both primary calcite and dolomite, approach the average chondritic values. In consanguineous rocks, calcite invariably has higher REE and LILE levels than dolomite. Hydrothermal reworking of carbonatites does not produce a unique geochemical fingerprint, leading instead to a variety of evolutionary trends that range from light-REE and LILE enrichment (Turiy Mys, Russia) to heavy-REE enrichment and LILE depletion (Bear Lodge, USA). These differences clearly attest to variations in the chemistry of carbonatitic fluids and, consequently, their ability to mobilize specific trace elements from earlier-crystallized minerals. An important telltale indicator of hydrothermal reworking is deviation from the primary, chondrite-like REE ratios (in particular, Y/Ho and Eu/Eu*), accompanied by a variety of other compositional changes depending on the redox state of the fluid (e.g., depletion of carbonates in Mn owing to its oxidation and sequestration by secondary oxides). The effect of supergene processes was studied on a single sample from Bear Lodge, which shows extreme depletion in Mn and Ce (both due to oxidation), coupled with enrichment in Pb and U, possibly reflecting an increased availability of Pb2+ and (UO2)2+ species in the system. On the basis of these findings, several avenues for future research can be outlined: (1) structural mechanisms of REE uptake by carbonates; (2) partitioning of REE and LILE between cogenetic calcite and dolomite; (3) the effects of fluorapatite, phlogopite and pyrochlore fractionation on the LILE budget of magmatic carbonates; (4) the cause(s) of coupled Mn-Ce depletion in some primary calcite; and (5) relations between fluid chemistry and compositional changes in hydrothermal carbonates.
DS201702-0201
2017
Yang, P.Chakhmouradian, A.R., Rehuir, E.P., Zaitsev, A.N., Coueslan, C., Xu, C., Kynicky, J., Hamid Mumin, A., Yang, P.Apatite in carbonatitic rocks: compositional variation, zoning, element partitioning and petrogeneitic significance.Lithos, in press available, 138p.TechnologyCarbonatite

Abstract: The Late Cretaceous (ca. 100 Ma) diamondiferous Fort à la Corne (FALC) kimberlite field in the Saskatchewan (Sask) craton, Canada, is one of the largest known kimberlite fields on Earth comprising essentially pyroclastic kimberlites. Despite its discovery more than two decades ago, petrological, geochemical and petrogenetic aspects of the kimberlites in this field are largely unknown. We present here the first detailed petrological and geochemical data combined with reconnaissance Nd isotope data on drill-hole samples of five major kimberlite bodies. Petrography of the studied samples reveals that they are loosely packed, clast-supported and variably sorted, and characterised by the presence of juvenile lapilli, crystals of olivine, xenocrystal garnet (peridotitic as well as eclogitic paragenesis) and Mg-ilmenite. Interclast material is made of serpentine, phlogopite, spinel, carbonate, perovskite and rutile. The mineral compositions, whole-rock geochemistry and Nd isotopic composition (Nd: + 0.62 to - 0.37) are indistinguishable from those known from archetypal hypabyssal kimberlites. Appreciably lower bulk-rock CaO (mostly < 5 wt%) and higher La/Sm ratios (12-15; resembling those of orangeites) are a characteristic feature of these rocks. Their geochemical composition excludes any effects of significant crustal and mantle contamination/assimilation. The fractionation trends displayed suggest a primary kimberlite melt composition indistinguishable from global estimates of primary kimberlite melt, and highlight the dominance of a kimberlite magma component in the pyroclastic variants. The lack of Nb-Ta-Ti anomalies precludes any significant role of subduction-related melts/fluids in the metasomatism of the FALC kimberlite mantle source region. Their incompatible trace elements (e.g., Nb/U) have OIB-type affinities whereas the Nd isotope composition indicates a near-chondritic to slightly depleted Nd isotope composition. The Neoproterozoic (~ 0.6-0.7 Ga) depleted mantle (TDM) Nd model ages coincide with the emplacement age (ca. 673 Ma) of the Amon kimberlite sills (Baffin Island, Rae craton, Canada) and have been related to upwelling protokimberlite melts during the break-up of the Rodinia supercontinent and its separation from Laurentia (North American cratonic shield). REE inversion modelling for the FALC kimberlites as well as for the Jericho (ca. 173 Ma) and Snap Lake (ca. 537 Ma) kimberlites from the neighbouring Slave craton, Canada, indicate all of their source regions to have been extensively depleted (~ 24%) before being subjected to metasomatic enrichment (1.3-2.2%) and subsequent small-degree partial melting. These findings are similar to those previously obtained on Mesozoic kimberlites (Kaapvaal craton, southern Africa) and Mesoproterozoic kimberlites (Dharwar craton, southern India). The striking similarity in the genesis of kimberlites emplaced over broad geological time and across different supercontinents of Laurentia, Gondwanaland and Rodinia, highlights the dominant petrogenetic role of the sub-continental lithosphere. The emplacement of the FALC kimberlites can be explained both by the extensive subduction system in western North America that was established at ca. 150 Ma as well as by far-field effects of the opening of the North Atlantic ocean during the Late Cretaceous.
DS201801-0053
2017
Yang, P.Reguir, E.P., Chakhmouradian, A.R., Zaitsev, A.N., Yang, P.Trace element variations and zoning in phlogopite from carbonatites and phoscorites.Carbonatite-alkaline rocks and associated mineral deposits , Dec. 8-11, abstract p. 8-9.carbonatites

Abstract: Phlogopite from carbonatites and phoscorites worldwide shows three major types of core-to-rim trends of compositional variation: Ba+Al-, Fe and Fe+Al enrichment. These major-element trends are accompanied by largely consistent changes in traceelement abundances. Uptake of Rb, Sr, Ba, Sc, V, Mn and HFSE by phlogopite is susceptible to changes in the availability of these elements due to precipitation of other early silicate and oxide phases (especially, magnetite, apatite and niobates). In rare cases, more complex oscillatory and sector patterns are juxtaposed over the principal evolutionary trend, indicating kinetic and crystal-chemical controls over element uptake. Phlogopite is a common accessory to major constituent of carbonatites and genetically related rocks (including phoscorites). Major-element variations of phlogopite from these rocks have been addressed in much detail in the literature (for references, see Reguir et al. 2009), whereas its trace-element characteristics and zoning patterns have so far received little attention. In this work, we examined the compositional variation of phlogopite from 23 carbonatite and phoscorite localities worldwide. The major-element compositions were determined using wavelength-dispersive X-ray spectrometry (WDS) and trace-element abundances by laser-ablation inductively-coupled-plasma mass-spectrometry (LA-ICPMS). Previously, two major core-to-rim zoning trends have been identified in micas from calcite carbonatites (Reguir et al. 2009, 2010). Phlogopite from Oka (Canada) and Iron Hill (USA), for example, involves an increase in kinoshitalite component rim-ward, accompanied by enrichment in high-field-strength elements (HFSE = Zr, Nb, Ta), Sr and Sc. At most other carbonatite localities (e.g., Kovdor in Russia, or Prairie Lake in Canada), phlogopite crystals exhibit rim-ward enrichment in Fe. In the present work, we confirmed these two common types of zoning, and identified new patterns that have not been reported in the previous literature. In addition to the common Fe-enrichment trend, which occurs in both carbonatites (e.g., Guli in Russia and Sokli in Finland) and phoscorites (e.g., Aley in Canada), we identified a Fe-Al-enrichment subtype of this zoning pattern observed, for example, in samples from the Shiaxiondong calcite carbonatite (China). Overall, the Fe-enrichment pattern is accompanied by rim-ward depletion in Ba, Rb and HFSE, coupled with enrichment in Mn. Other trace elements exhibit no consistent variation among the studied samples. The Shiaxiondong material is characterized by the highest recorded Rb values, ranging from 1120 to 660 ppm. Phlogopite from the Kovdor calcite-forsterite-magnetite phoscorite contains the highest recorded levels of Nb and Ta, ranging from 320 ppm and 40 ppm, respectively, in the core to 85 ppm and 4 ppm in the rim. The maximum levels of Zr (up to 50 ppm) were observed in the core of Prairie Lake phlogopite, whereas its rim contains the highest measured Mn content (up to 4100 ppm). The levels of Sc are typically below 100 ppm in samples from calcite and dolomite carbonatites, but may reach 280 ppm in phoscorites. Interestingly, phlogopite from phoscorites shows rim-ward enrichment in Sc, whereas the opposite trend is observed in carbonatitic micas. Phlogopite from calcite carbonatites at Zibo (China) and Valentine Township (Canada), and from phoscorites at Aley (Canada) shows an unusual zoning pattern involving depletion in Fe, which is accompanied by a decrease in Al, Ba, Sr, Zr, Hf, Y, Sc and V abundances. The concentrations of other trace elements, including Nb and Ta show inconsistent variations. In the Aley phoscorite, phlogopite is enriched in Ba (up to 15000 ppm in the core and < 7500 ppm in the rim), but poor in Sr (80 and 35 ppm in the core and rim, respectively) relative to those from the Zibo and Valentine carbonatites. Zirconium levels reach 200 and 170 ppm in the core, and drop to < 40 and 60 ppm in the rim of the Valentine and Zibo samples, respectively. In the Aley sample, the content of Zr does not exceed 55 ppm. The Zibo sample is also enriched in V (up to 230 and 160 ppm in the core and rim, respectively) relative to the two other samples (< 100 ppm V). The Sc and Hf levels are consistently low (less than 30 and 4 ppm, respectively). In addition to simple core-rim patterns, phlogopite from carbonatites and phoscorites may exhibit oscillatory zoning, which involves periodic variations in Fe/Mg ratio. Iron-rich zones are relatively depleted in Mn, but enriched in Nb. One sample of phoscoritic phlogopite (Aley) exhibits striking sector zoning juxtaposed over the overall Feenrichment trend and Fe-Mg oscillations. In terms of major elements, basal sectors perpendicular to [001] are enriched in Fe and Al, but depleted in Mg and K relative to the flank sectors. This enrichment is accompanied by higher Ba, Sr and HFSE levels in the basal sector. Our data confirm that there is no universal pattern of zoning in carbonatitic or phoscoritic phlogopite, and variations in the content of most trace elements are strongly coupled to major-element patterns. Three major core-to-rim variation trends, as well as juxtaposed oscillatory and sector patterns, can be recognized. The observed compositional variations indicate that, in the majority of cases, the trace-element composition of phlogopite is controlled by partitioning of Rb, Sr, Ba, Sc, V, Mn and HFSE between this mineral, its parental magma, and co-precipitating early phases. Among the latter, magnetite, apatite and niobates appear to exert the greatest influence on element distributions. More complex oscillatory and sector patterns imply the presence of kinetic and crystal-chemical controls over element uptake in certain carbonatitic systems
DS201012-0295
2010
Yang, Q.Huang, X., Niu, Y., Xu, Y-G., Chen, L-L., Yang, Q.Mineralogical and geochemical constraints on the preogenesis of post collisional potassic and ultrpotassic rocks from Western Yunnan, SW China.Journal of Petrology, Vol. 51, 8, pp. 1617-1654.ChinaAlkalic
DS201909-2106
2019
Yang, Q.Wang, T., Gao, S.S., Dai, Y., Yang, Q., Liu, K.H.Lithospheric structure and evolution of southern Africa: constraints from joint inversion of Rayleigh wave dispersion and receiver functions.Geochemistry, Geophysics, Geosystems, Vol. 20, 7, pp. 3311-3327.Africa, South Africageophysics

Abstract: We conduct a joint inversion of teleseismic receiver functions and Rayleigh wave phase velocity dispersion from both ambient noise and earthquakes using data from 79 seismic stations in southern Africa, which is home to some of the world's oldest cratons and orogenic belts. The area has experienced two of the largest igneous activities in the world (the Okavango dyke swarm and Bushveld mafic intrusion) and thus is an ideal locale for investigating continental formation and evolution. The resulting 3-D shear wave velocities for the depth range of 0-100 km and crustal thickness measurements show a clear spatial correspondence with known geological features observed on the surface. Higher than normal mantle velocities found beneath the southern part of the Kaapvaal craton are consistent with the basalt removal model for the formation of cratonic lithosphere. In contrast, the Bushveld complex situated within the northern part of the craton is characterized by a thicker crust and higher crustal Vp/Vs but lower mantle velocities, which are indicative of crustal underplating of mafic materials and lithospheric refertilization by the world's largest layered mafic igneous intrusion. The thickened crust and relatively low elevation observed in the Limpopo belt, which is a late Archean collisional zone between the Kaapvaal and Zimbabwe cratons, can be explained by eclogitization of the basaltic lower crust. The study also finds evidence for the presence of a stalled segment of oceanic lithosphere beneath the southern margin of the Proterozoic Namaqua-Natal mobile belt.
DS202008-1401
2020
Yang, S.Huang, S., Tschauner, O., Yang, S., Humayun, M.HIMU signature trapped in a diamond from the mantle transition zone.Goldschmidt 2020, 1p. AbstractMantlediamond inclusion

Abstract: Mantle plumes sample the deep mantle. A limited number of geochemical endmember components can describe the isotopic and compositional variations in the ocean island basalts (OIBs), which are produced by plume volcanism. The endmembers are correlated to compositions in the OIB source regions or represent incorporation of material upon ascent. However, their actual nature and origins are still highly debated. The depths of plume sources have been proposed to be anywhere between the core-mantle boundary and the upper mantle, and need not be the same for all plume-related volcanic activities. Using a combination of synchrotron micro-X ray fluorescence and -diffraction mapping, and in-situ Laser Ablation Inductively Coupled Plasma Mass Spectrometry, we show that the elemental features of HIMU-rich OIBs, such as Bermuda, St Helena, and Cook-Austral, exactly match the geochemical signature of a multiphase inclusion in a diamond. The geochemical signature in our studied diamond inclusion is markedly different from that of inclusions in lithospheric diamonds. The phases identified in the inclusion are majorite-rich garnet, ilmenite, the sodic 10Å-phase (TAP), and liebermannite. Furthermore, we show that this inclusion was entrapped at 14.5 ± 0.5 GPa (420-440 km) and 1450 ± 50 K. At the conditions of entrapment, the diamond inclusion phase assembly was garnet + ilmenite + liebermannite + clinopyroxene + stishovite + fluid. Sodic TAP is a retrograde product of reaction between clinopyroxene, stishovite, and fluid upon ascent. Its presence shows that the HIMU source is water-saturated. Entrapment in diamond indicates that the fluid also contained carbonate. The conditions of 14.5 ± 0.5 GPa and 1450 ± 50 K plot right on top of the alkaline carbonatite solidus, and match the formation of carbonatitic melt from subducted slabs plus diamond formation from reaction of carbonate with iron. In summary, our data show that the transition zone source accounts for the global HIMU endmember.
DS202008-1459
2020
Yang, S.Yang, S., Humayaun, M., Salters, V.J.M.Elemental constrains on the amount of recycled crust in the generation of mid-ocean basalts.Science Advances, https://phys.org/ news/2020-06- geochemists- mystery-earth-crust .htmlMantlegeochemistry

Abstract: Mid-oceanic ridge basalts (MORBs) are depleted in incompatible elements, but ridge segments far from mantle plumes frequently erupt chemically enriched MORBs (E-MORBs). Two major explanations of E-MORBs are that these basalts are generated by the melting of entrained recycled crust (pyroxenite) beneath ridges or by the melting of refertilized peridotites. These two hypotheses can be discriminated with compatible element abundances from Sc to Ge, here termed the ScGe elements. Here, we demonstrate that E-MORBs have systematically lower Ge/Si and Sc contents and slightly higher Fe/Mn and Nb/Ta ratios than depleted MORBs (D-MORBs) due to the mixing of low-degree pyroxenite melts. The Ge/Si ratio is a new tracer that effectively discriminates between melts derived from peridotite sources and melts derived from mixed pyroxenite-peridotite sources. These new data are used to estimate the distribution of pyroxenite in the mantle sources of global MORB segments.
DS201212-0824
2013
Yang, S-H.Zhao, X-M., Zhang, H-F., Su, F., Lo, C-H., Yang, S-H., Guo, J-H.Phlogopite 40 Ar/39 Ar geochronology of mantle xenoliths from the North Chin a craton: constraints on the eruption ages of of Cenozoic basalts.Gondwana Research, Vol. 23, 1, pp. 208-219.ChinaGeochronology
DS201412-0960
2014
Yang, S-H.Wang, H., Wu, Y-B., Gao, S., Zheng, J-P., Liu, Q., Liu, X-C., Qin, Z-W., Yang, S-H., Gong, H-J.Deep subduction of continental crust in accretionary orogen: evidence from U-Pb dating on diamond-bearing zircons from the Qinling orogen, central China.Lithos, Vol. 190-191, pp. 420-429.ChinaUHP
DS200512-1213
2005
Yang, T.Yang, T., Shen, Y.P wave velocity structure of the crust and uppermost mantle beneath Iceland from local earthquake tomography.Earth and Planetary Science Letters, Advanced in press,Europe, IcelandMantle tomography, hot spot, plume
DS200612-1564
2006
Yang, T.Yang, T., Shen, Y., Van der lee, S., Solomon, S.C., Hung, S.H.Upper mantle structure beneath the Azores hotspot from finite frequency seismic tomography.Earth and Planetary Science Letters, Vol. 250, 1-2, pp. 11-26.AzoresGeophysics - seismics
DS200912-0446
2009
Yang, T.Liu, Q., Yang, T., Zeng, Q., Zheng, J., Luo, Y., Qui, N., Xu, H., Jin, Z.Magnetic study of the UHP eclogites from the Chinese Continental Scientific drilling project.Journal of Geophysical Research, Vol. 114, B02106.ChinaUHP
DS201012-0454
2010
Yang, T.Liu, Q., Zeng, Q., Zheng, J., Yang, T., Qui, N., Liu, Z., Lou, Y., Jin, Z.Magnetic properties of serpentinized garnet peridotites from the CCSD main hole in the Sulu ultrahigh pressure metamorphic belt, eastern China.Journal of Geophysical Research, Vol. 115, B6, B06104ChinaUHP
DS201412-1003
2014
Yang, T.Yang, T., Leng, W.Dynamics of hidden hotspot tracks beneath the continental lithosphere.Earth and Planetary Science Letters, Vol. 401 pp. 294-300.MantlePlume
DS201803-0485
2018
Yang, T.Wang, D., Wang, X-L., Cai, Y., Goldstein, S.L., Yang, T.Do Hf isotopes in magmatic zircons represent those of their host rocks?Journal of Asian Earth Sciences, Vol. 154, pp. 202-212.Mantlezircons

Abstract: Lu-Hf isotopic system in zircon is a powerful and widely used geochemical tracer in studying petrogenesis of magmatic rocks and crustal evolution, assuming that zircon Hf isotopes can represent initial Hf isotopes of their parental whole rock. However, this assumption may not always be valid. Disequilibrium partial melting of continental crust would preferentially melt out non-zircon minerals with high time-integrated Lu/Hf ratios and generate partial melts with Hf isotope compositions that are more radiogenic than those of its magma source. Dissolution experiments (with hotplate, bomb and sintering procedures) of zircon-bearing samples demonstrate this disequilibrium effect where partial dissolution yielded variable and more radiogenic Hf isotope compositions than fully dissolved samples. A case study from the Neoproterozoic Jiuling batholith in southern China shows that about half of the investigated samples show decoupled Hf isotopes between zircons and the bulk rocks. This decoupling could reflect complex and prolonged magmatic processes, such as crustal assimilation, magma mixing, and disequilibrium melting, which are consistent with the wide temperature spectrum from ~630?°C to ~900?°C by Ti-in-zircon thermometer. We suggest that magmatic zircons may only record the Hf isotopic composition of their surrounding melt during crystallization and it is uncertain whether their Hf isotopic compositions can represent the primary Hf isotopic compositions of the bulk magmas. In this regard, using zircon Hf isotopic compositions to trace crustal evolution may be biased since most of these could be originally from disequilibrium partial melts.
DS201906-1327
2019
Yang, T.Muller, R.D., Zahirovic, S., Williams, S.E., Cannon, J., Seton, M., Bower, D.J., Tetley, M., Heine, C., Le Breton, E., Liu, S., Russell, S.H.J., Yang, T., Leonard, J., Gurnis, M.A global plate model including lithospheric deformation along major rifts and orogens since the Triassic.Tectonics, May 5, 36p. Mantleplate tectonics

Abstract: Global deep-time plate motion models have traditionally followed a classical rigid plate approach, even though plate deformation is known to be significant. Here we present a global Mesozoic-Cenozoic deforming plate motion model that captures the progressive extension of all continental margins since the initiation of rifting within Pangea at ~240 Ma. The model also includes major failed continental rifts and compressional deformation along collision zones. The outlines and timing of regional deformation episodes are reconstructed from a wealth of published regional tectonic models and associated geological and geophysical data. We reconstruct absolute plate motions in a mantle reference frame with a joint global inversion using hotspot tracks for the last 80 million years and minimizing global trench migration velocities and net lithospheric rotation. In our optimized model net rotation is consistently below 0.2°/Myr, and trench migration scatter is substantially reduced. Distributed plate deformation reaches a Mesozoic peak of 30 million km2 in the Late Jurassic (~160-155 Ma), driven by a vast network of rift systems. After a mid-Cretaceous drop in deformation it reaches a high of 48 million km2 in the Late Eocene (~35 Ma), driven by the progressive growth of plate collisions and the formation of new rift systems. About a third of the continental crustal area has been deformed since 240 Ma, partitioned roughly into 65% extension and 35% compression. This community plate model provides a framework for building detailed regional deforming plate networks and form a constraint for models of basin evolution and the plate-mantle system.
DS201907-1562
2019
Yang, T.Muller, D., Zahirovic, S., Williams, S.E., Cannon, J., Seton, M., Bower, D.J., Tetley, M., Heine, C., Le Breton, E., Liu, S., Russell, S.H.J., Yang, T., Leonard, J., Gurnis, M.A global plate model including lithospheric deformation along major rifts and orogens since the Triassic.Tectonics, in press available, 37p.Africa, globalplate tectonics, rotation

Abstract: Global deep-time plate motion models have traditionally followed a classical rigid plate approach, even though plate deformation is known to be significant. Here we present a global Mesozoic-Cenozoic deforming plate motion model that captures the progressive extension of all continental margins since the initiation of rifting within Pangea at ~240 Ma. The model also includes major failed continental rifts and compressional deformation along collision zones. The outlines and timing of regional deformation episodes are reconstructed from a wealth of published regional tectonic models and associated geological and geophysical data. We reconstruct absolute plate motions in a mantle reference frame with a joint global inversion using hot spot tracks for the last 80 million years and minimizing global trench migration velocities and net lithospheric rotation. In our optimized model, net rotation is consistently below 0.2°/Myr, and trench migration scatter is substantially reduced. Distributed plate deformation reaches a Mesozoic peak of 30 × 106 km2 in the Late Jurassic (~160-155 Ma), driven by a vast network of rift systems. After a mid-Cretaceous drop in deformation, it reaches a high of 48 x 106 km2 in the Late Eocene (~35 Ma), driven by the progressive growth of plate collisions and the formation of new rift systems. About a third of the continental crustal area has been deformed since 240 Ma, partitioned roughly into 65% extension and 35% compression. This community plate model provides a framework for building detailed regional deforming plate networks and form a constraint for models of basin evolution and the plate-mantle system.
DS200512-1214
2005
Yang, T.N.Yang, T.N., Zeng, L., Liou, J.G.Mineral evolution of a garnet pyroxenite nodule within eclogite, eastern Sulu ultrahigh-pressure metamorphic terrane, east China.Journal of Metamorphic Geology, Vol. 23, 8, pp. 667-680.ChinaUHP
DS200612-0788
2006
Yang, T.N.Leech, M.L., Webb, L.E., Yang, T.N.Diachronous histories for the Dabie Sulu orogen from high temperature geochronology.Geological Society of America, Special Paper, No. 403, pp. 1-22.ChinaUHP
DS200612-1515
2006
Yang, T.N.Webb, L.E., Leech, M.L., Yang, T.N.49 Ar 39 Ar thermochronology of the Sulu terrane: Late Triassic exhumation of high and ultrahigh pressure rocks -implications for Mesozoic tectonics East Asia.Geological Society of America, Special Paper, No. 403, pp. 77-92.ChinaUHP
DS200612-1516
2006
Yang, T.N.Webb, L.E., Leech, M.L., Yang, T.N.40 Ar 39 Ar thermochronology of the Sulu terrane: Late Triassic exhumation of high and UHP rocks and implications for Mesozoic tectonics in East Asia.Geological Society of America Special Paper, No. 403, pp. 77-92.ChinaUHP - Sulu, Dabie, geothermometry
DS200812-1293
2008
Yang, T.N.Yang, T.N., Zeng, L., Zhao, Z.R., Liou, J.G.Retrograde reaction of an ultrahigh pressure metamorphic spinel pyroxenite lens, northeast Sulu UHP terrane, eastern China.International Geology Review, Vol. 50, 1, pp. 32-47.ChinaUHP
DS1999-0780
1999
Yang, W.Wang, X., Neubauer, F., Genser, J., Yang, W.The Dabie ultra high pressure (UHP) unit, Central China: a Cretaceous extensional allochthon superposed on a Triassic Orogen.Terra Nova, Vol. 10, No. 5, p. 260-67.ChinaTectonics, metamorphism, Dabie
DS2003-1521
2003
Yang, W.Yang, W.Flat mantle reflectors in eastern China: possible evidence for lithospheric thinningTectonophysics, Vol. 369, 3-4, July pp. 219-30.ChinaGeophysics - seismics, Heterogeneity
DS200412-2172
2003
Yang, W.Yang, W.Flat mantle reflectors in eastern China: possible evidence for lithospheric thinning.Tectonophysics, Vol. 369, 3-4, July pp. 219-30.ChinaGeophysics - seismics Heterogeneity
DS200912-0833
2009
Yang, W.Yang, W., Teng, F-Z., Zhang, H-F.Chondritic magnesium isotopic composition of the terrestrial mantle: a case study of peridotite xenoliths from the North Chin a craton.Earth and Planetary Science Letters, Vol. 288, 3-4, pp. 475-481.ChinaGeochronology
DS201112-0612
2011
Yang, W.Liu, S-A., Teng, F-Z., Yang, W., Wu, F-Y.High temperature inter-mineral magnesium isotope fractionation in mantle xenoliths from the North Chin a craton.Earth and Planetary Science Letters, Vol. 308, 1-2, pp. 131-140.ChinaGeochronology UHP
DS201312-0539
2013
Yang, W.Liang, Q., Meng, Y., Yan, C., Krasnicki, S., Lai, J., Hemawan, K., Shu,H., Popov, D., Yu,T., Yang, W., Mao, H., Hemley, R.Developments in synthesis, characterization, and application of large high-quality CVD single crystal diamond.Journal of Superhard Materials, Vol. 35, 4, pp. 195-213.TechnologyDiamond synthetics
DS201312-0908
2013
Yang, W.Teng, F-Z., Yang, W., Rudnick, R., Hu, Y.Heterogeneous magnesium isotopic composition of the lower continental crust: a xenolith perspective.Geochemistry, Geophysics, Geosystems: G3, Vol. 14, 9, pp. 3844-3856.MantleXenoliths
DS201412-1024
2014
Yang, W.Zhang, L., Meng, Y., Yang, W.,Wang, L., Mao, W.L., Zeng, Q-S., Jeong, J.S., Wagner, A.J., Mkhoyan, K.A., Liu, W., Xu, R., Mao, H-K.Disproportionation of (Mg,Fe) SiO3 perovskite in Earth's deep lower mantle.Science, Vol. 344, no. 6186, pp. 877-882.MantlePerovskite
DS201603-0432
2016
Yang, W.Yang, W., Teng, F-Z., Li, W-Y., Liu, S-A., Ke, S., Liu, Y-S., Zhang, H-F., Gao, S.Magnesium isotopic composition of the deep continental crust.American Mineralogist, Vol. 101, pp. 243-252.MantleMineralogy
DS201703-0410
2017
Yang, W.Jia, X., Wang, X., Yang, W.Petrogenesis and geodynamic implications of the Early Paleozoic potassic and ultrapotassic rocks in the south Chin a block.Journal of Asian Earth Sciences, Vol. 135, pp. 80-94.ChinaAlkaline rocks

Abstract: In this paper, some potassic and ultrapotassic rocks in the South China Block (SCB) have been recognized, according to a set of new geochronological, geochemical and Sr-Nd isotopic data. Zircon U-Pb dating from six plutons yield consistent crystallization ages of 445-424 Ma. These potassic and ultrapotassic rocks can be geochemically subdivided into three groups. Group 1, represented by the Longchuan gabbro, longmu diabase, Tangshang and Danqian diorite (445-433 Ma), have low silica contents (SiO2 = 47.38-54.16 wt.%), and high MgO (4.21-9.51 wt.%) and total alkalis (Na2O + K2O = 3.08-5.57 wt.%), with K2O/Na2O ratios of 0.62-1.82. They are enriched in LREE and depleted in Ba, Sr and Ta-Nb-Ti, and exhibit relatively high initial 87Sr/86Sr ratios (0.70561-0.71128), low eNd(430 Ma) values (-8.4 to -3.2), suggesting that they were most plausibly generated by the partial metling of enriched mantle source (EMI). Group 2, from the Huwei diorite (424 Ma), have 45.68-52.87 wt.% of SiO2, 5.79-9.25 wt.% of MgO and 52-65 of mg-number. They have significantly higher Th (9.92 ppm), Ce (88.0-115 ppm) concentration and Ce/Yb (27.6-46.8), Th/Yb ratios (2.58-7.99), and relatively low initial 87Sr/86Sr ratios (0.70501-0.70599), and high eNd(430 Ma) values (-2.1 to -1.5). We propose that they originated from the partial melting of the depleted mantle source with subsequent contamination by crustal materials. Group 3, represented by the Daning lamprophyre (~445 Ma), has SiO2 contents ranging from 41.73 wt.% to 45.22 wt.%, MgO from 13.74 wt.% to 15.16 wt.%, and mg-muber from 73 to 77, with high K2O/Na2O ratios (>2.0). They have 87Sr/86Sr ratios of 0.62912-0.70384 and eNd(t = 430 Ma) values of -6.4 to -6.3, indicating that the source components are close to the EMI source, with significant sediments involved. These Silurian potassic and ultrapotassic rocks in the SCB can be responsible for post-orogenic delamination and intra-plate extension. And the delamination had a small size and a long duration, and a negligible impact.
DS2002-0781
2002
Yang, W.Z.Jiang, Y.R., Jiang, S.Y., Ling, H.F., Zhou, X.R., Rui, X.J., Yang, W.Z.Petrology and geochemistry of shoshonitic plutons from the western Kunlun OrogenLithos, Vol.63,3-4, pp. 165-187.ChinaShoshonites
DS1983-0638
1983
Yang, X.Yang, X.Microstructure and Stress Estimation of Minerals in Lherzolite Residual Fragments.Acta Geol. Sinica., Vol. 57, No. 4, PP. 391-400.ChinaBlank
DS201312-0528
2013
Yang, X.Lai, X., Yang, X.Geochemical characteristics of the Bayan Obo giant REE Nb Fe deposit: constraints on its genesis.Journal of South American Earth Sciences, Vol. 41, pp. 99-112.ChinaDeposit - Bayan Obo
DS201512-1995
2015
Yang, X.Yang, X.OH solubility in olivine in the peridotote-COH system under reducing conditions and implications for water storage and hydrous melting in the reducing upper mantle.Earth and Planetary Science Letters, Vol. 432, pp. 199-209.MantleMelting

Abstract: Experimental studies of OH solubility in peridotite minerals are of crucial importance for understanding some key geochemical, geophysical and geodynamical properties of the upper mantle. In reducing depths of the upper mantle, C-O-H fluids are dominated by CH4 and H2O. However, available experimental H-annealing of olivine concerning water storage capacity in the reducing upper mantle has been exclusively carried out by equilibrating olivine with H2O only. In this study, OH solubility in olivine has been investigated by annealing natural olivine crystals under peridotite-bearing and CH4-H2O-present conditions with piston cylinder and multi-anvil apparatus. Experiments were performed at 1-7 GPa and 1100-1350?°C and with oxygen fugacity controlled by Fe-FeO buffer, and OH solubilities were measured from polarized infrared spectra. The olivines show no change in chemical composition during the experiments. The infrared spectra of all the annealed olivines show OH bands in the range 3650-3000 cm-1, at both high (>3450 cm-1) and low (<3450 cm-1) frequency, and the bands at ~3400-3300 cm-1 are greatly enhanced above ~3 GPa and 1300?°C. The determined H2O solubility is ~90-385 ppm for the olivine coexisting with H2O (1-7 GPa and 1100?°C), and is ~40-380 ppm for the olivine coexisting with CH4-H2O (1-7 GPa and 1100-1350?°C). When CH4 is present in the equilibrium fluid, the H2O solubility is reduced by a factor of ~2.3 under otherwise identical conditions, indicating a strong effect of CH4 on the partitioning of water between olivine and coexisting fluid. The storage capacity of water in the reducing upper mantle is, modeled with the measured solubility of olivine and available partition coefficients of water between coexisting minerals, up to ~2 orders of magnitude lower than some previous estimates. Considering the temperature along the geotherm in the reducing oceanic upper mantle, the required H2O concentration to trigger hydrous melting is 250 and 535 ppm at ~100 and 210 km depth, respectively, and is even larger at greater depths. These values exceed the typical H2O abundance (~100±50 ppm~100±50 ppm) in the upper mantle, suggesting that pervasive hydrous melting at reducing depths of the oceanic upper mantle is not likely. Similar arguments may also be casted for the reducing deep upper mantle in the continental regions.
DS201512-1996
2015
Yang, X.Yang, X., Williams, M.Landforms and processes in arid and semi-arid environments.Catena, Vol. 134, pp. 4-13.Africa, South Africa, AustraliaGeomorphology
DS201702-0256
2017
Yang, X.Yang, X., Lai, X., Pirajno, F., Liu, Y., Mingxing, L., Sun, W.Genesis of the Bayan Obo Fe_REE-Nb formation in Inner Mongolia, North Chin a craton: a perspective review.Precambrian Research, Vol. 288, pp. 39-71.ChinaDeposit - Bayan Obo

Abstract: The Bayan Obo deposit in Inner Mongolia, North China Craton (NCC) is the largest rare-earth element (REE) resource in the world. Due to the complex element and mineral compositions and the activity of several geological events, the ore-forming mechanism is still controversial. Previous models are reviewed here to provide information for further investigation on the Bayan Obo deposit. In this study, we summarize all different types of Fe-REE-Nb mineralization using field observations and microscope work, in which we recognize 9 types of Fe-REE-Nb ores in the Bayan Obo ore district. By compiling and re-evaluating a large number of published geochemical data, this paper provides solid evidence that the Bayan Obo deposit formed through interaction between sedimentary rocks and carbonatite magmatism. From the results of our review, it can be conjectured that the formation of iron ores was originated from sedimentation (Pt1), whereas the formation of REE mineralized dolomite might be related to interaction and reaction between the carbonatite magmas and/or associated fluids with sedimentary carbonate rocks, with the REE-bearing carbonatite magmas having undergone intense fractionation enrichment process. The C-O-S-Fe-Mg isotopes indicate that the REE-Nb mineralization was derived from metasomatism (fenitic alteration) of sedimentary carbonate. A new model is proposed for this unique REE-Nb mineralization, which is related to the subduction of Siberian Craton beneath the North China Craton since Early Paleozoic period. We interpret that the Bayan Obo Fe-REE-Nb ore deposits and their massive barren host, H8 dolomite, were generated as a result of interaction of fluids expelled from a subcontinental lithospheric mantle (SCLM)-derived carbonatite magma with sedimentary carbonates.
DS201706-1095
2017
Yang, X.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.
DS201712-2679
2018
Yang, X.Chen, C., Hersh, G., Fischer, K.M., Andronicos, C.L., Pavlis, G.L., Hamburger, M.W., Marshak, S., Larson, T., Yang, X.Lithospheric discontinuities beneath the U.S. Midcontinent - signatures of Proterozoic terrane accretion and failed rifting.Earth and Planetary Science Letters, Vol. 481, pp. 223-235.United States, Illinois, Indiana, Kentuckygeophysics - seismics Reelfoot Rift

Abstract: Seismic discontinuities between the Moho and the inferred lithosphere-asthenosphere boundary (LAB) are known as mid-lithospheric discontinuities (MLDs) and have been ascribed to a variety of phenomena that are critical to understanding lithospheric growth and evolution. In this study, we used S-to-P converted waves recorded by the USArray Transportable Array and the OIINK (Ozarks-Illinois-Indiana-Kentucky) Flexible Array to investigate lithospheric structure beneath the central U.S. This region, a portion of North America's cratonic platform, provides an opportunity to explore how terrane accretion, cratonization, and subsequent rifting may have influenced lithospheric structure. The 3D common conversion point (CCP) volume produced by stacking back-projected Sp receiver functions reveals a general absence of negative converted phases at the depths of the LAB across much of the central U.S. This observation suggests a gradual velocity decrease between the lithosphere and asthenosphere. Within the lithosphere, the CCP stacks display negative arrivals at depths between 65 km and 125 km. We interpret these as MLDs resulting from the top of a layer of crystallized melts (sill-like igneous intrusions) or otherwise chemically modified lithosphere that is enriched in water and/or hydrous minerals. Chemical modification in this manner would cause a weak layer in the lithosphere that marks the MLDs. The depth and amplitude of negative MLD phases vary significantly both within and between the physiographic provinces of the midcontinent. Double, or overlapping, MLDs can be seen along Precambrian terrane boundaries and appear to result from stacked or imbricated lithospheric blocks. A prominent negative Sp phase can be clearly identified at 80 km depth within the Reelfoot Rift. This arrival aligns with the top of a zone of low shear-wave velocities, which suggests that it marks an unusually shallow seismic LAB for the midcontinent. This boundary would correspond to the top of a region of mechanically and chemically rejuvenated mantle that was likely emplaced during late Precambrian/early Cambrian rifting. These observations suggest that the lithospheric structure beneath the Reelfoot Rift may be an example of a global phenomenon in which MLDs act as weak zones that facilitate the removal of cratonic lithosphere that lies beneath.
DS202002-0200
2019
Yang, X.Lai, X., Yang, X.U-Pb ages and Hf isotope of zircons from a carbonatite dyke in the Bayan Obo Fe-REE deposit in Inner Mongolia: its geological significance.Acta Geologica Sinica, Vol. 93, 6, pp. 1783-1796.China, MongoliaREE

Abstract: Detailed studies on U-Pb ages and Hf isotope have been carried out in zircons from a carbonatite dyke associated with the Bayan Obo giant REE-Nb-Fe deposit, northern margin of the North China Craton (NCC), which provide insights into the plate tectonic in Paleoproterozoic. Analyses of small amounts of zircons extracted from a large sample of the Wu carbonatite dyke have yielded two ages of late Archaean and late Paleoproterozoic (with mean 207Pb/206Pb ages of 2521±25 Ma and 1921±14 Ma, respectively). Mineral inclusions in the zircon identified by Raman spectroscopy are all silicate minerals, and none of the zircon grains has the extremely high Th/U characteristic of carbonatite, which are consistent with crystallization of the zircon from silicate, and the zircon is suggested to be derived from trapped basement complex. Hf isotopes in the zircon from the studied carbonatite are different from grain to grain, suggesting the zircons were not all formed in one single process. Majority of ?Hf(t) values are compatible with ancient crustal sources with limited juvenile component. The Hf data and their TDM2 values also suggest a juvenile continental growth in Paleoproterozoic during the period of 1940-1957 Ma. Our data demonstrate the major crustal growth during the Paleoproterozoic in the northern margin of the NCC, coeval with the assembly of the supercontinent Columbia, and provide insights into the plate tectonic of the NCC in Paleoproterozoic.
DS2003-1522
2003
Yang, X.M.Yang, X.M., Yang, X.Y., Zheng, Y.F., Le Bas, M.J.A rare earth element rich carbonatite dyke at Bayan Obo, Inner Mongolia, NorthMineralogy and Petrology, Vol. 78, 1-2, pp. 93-110.ChinaREE, Deposit - Bayan Obo
DS200412-2173
2003
Yang, X.M.Yang, X.M., Yang, X.Y., Zheng, Y.F., Le Bas, M.J.A rare earth element rich carbonatite dyke at Bayan Obo, Inner Mongolia, North China.Mineralogy and Petrology, Vol. 78, 1-2, pp. 93-110.ChinaREE Deposit - Bayan Obo
DS2001-1279
2001
Yang, X.Y.Yang, X.Y., Zheng, Y.F., Liu, D., Dai, J.Chemical and carbon isotope compositions of fluid inclusions in peridotite xenoliths and eclogites...Physics and Chemistry of the Earth Pt. A. Solid Earth, Vol. 26, No. 9-10, pp. 705-18.ChinaGeodynamics
DS2001-1280
2001
Yang, X.Y.Yang, X.Y., Zheng, Y.F., Liu, D., Dai, J.Chemical and carbon isotope compositions of igneous rocks from Lower Yangtze region, constraints on sourcesPhysics and Chemistry of the Earth, Vol. 26, pt. A. No. 9-10, pp. 705-18.ChinaPeridotite - xenoliths
DS2003-1522
2003
Yang, X.Y.Yang, X.M., Yang, X.Y., Zheng, Y.F., Le Bas, M.J.A rare earth element rich carbonatite dyke at Bayan Obo, Inner Mongolia, NorthMineralogy and Petrology, Vol. 78, 1-2, pp. 93-110.ChinaREE, Deposit - Bayan Obo
DS200412-2173
2003
Yang, X.Y.Yang, X.M., Yang, X.Y., Zheng, Y.F., Le Bas, M.J.A rare earth element rich carbonatite dyke at Bayan Obo, Inner Mongolia, North China.Mineralogy and Petrology, Vol. 78, 1-2, pp. 93-110.ChinaREE Deposit - Bayan Obo
DS200512-1215
2005
Yang, X.Y.Yang, X.Y.Geochemistry of rare gases in eclogites from Dabie Shan orogenic belt, eastern China.Journal of the Geological Society of India, Vol. 65, 4, pp. 479-481.ChinaEclofites, UHP
DS2003-1523
2003
Yang, X-M.Yang, X-M., Yang, X-Y., Zheng, Y.F., Le Bas, M.J.A rare earth carbonatite dyke at Bayan Obo, Inner Mongolia, north ChinaMineralogy and Petrology, Vol. 78, 1-2, pp. 93-110.ChinaCarbonatite, Deposit - Bayan Obo
DS200712-1199
2007
Yang, X-M.Yang,X-M.Using the Rittmann serial index to define the alkalinity of igneous rocks.Neues Jahrbuch fur Geologie und Palaontologie , Vol. 184, 1, August pp. 95-103.TechnologyAlkalic
DS200712-1200
2007
Yang, X-M.Yang,X-M.Using the Rittmann serial index to define the alkalinity of igneous rocks.Neues Jahrbuch fur Geologie und Palaontologie , Vol. 184, 1, August pp. 95-103.TechnologyAlkalic
DS2003-1523
2003
Yang, X-Y.Yang, X-M., Yang, X-Y., Zheng, Y.F., Le Bas, M.J.A rare earth carbonatite dyke at Bayan Obo, Inner Mongolia, north ChinaMineralogy and Petrology, Vol. 78, 1-2, pp. 93-110.ChinaCarbonatite, Deposit - Bayan Obo
DS200912-0834
2009
Yang, X-Y.Yang, X-Y., Sun, W-D., Zhang, X., Zheng, Y-F.Geochemical constraints on the genesis of the Bayan Obo Fe Nb REE deposit in the Inner Mongolia, China.Geochimica et Cosmochimica Acta, Vol. 73, 5, March 1, pp. 1417-1436.China, MongoliaCarbonatite
DS201212-0393
2012
Yang, X-Y.Lai, X-D., Yang, X-Y.Geochemical characteristics of the Bayan Obo giant REE-Nb-Fe deposit: constraints on its genesis.Journal of South American Earth Sciences, in press available 58p.ChinaCarbonatite
DS201712-2701
2017
Yang, X-Y.Liu, Y-L., Ling, M-X., Williams, I.S., Yang, X-Y., Yan Wang, C., Sun, W.The formation of the giant Bayan Obo REE-Nb-Fe deposit, north China, Mesoproterozoic carbonatite and overprinted Palaeozoic dolomitization.Ore Geology Reviews, in press available, 47p.Chinadeposit - Bayan Obo

Abstract: The Bayan Obo ore deposit in Inner Mongolia, North China, the largest-known rare earth element (REE) deposit in the world, is closely associated with carbonatite dykes. Scarce zircon grains, with a wide range of ages and diverse origins, have been extracted from the Wu dyke, a REE-enriched calcitic carbonatite dyke 2?km from the East Ore Body of the Bayan Obo deposit. Three zircon populations were identified based on ages and trace element compositions: 1) Captured zircons with Paleoproterozoic and Archean ages. These zircons have REE patterns and moderate Th/U ratios similar to zircon with silicate inclusions from basement igneous rocks, which have been recognized as contaminants from wall rocks. 2) Carbonatite magmatic zircons with Mesoproterozoic ages. These zircons have high to extremely high Th/U ratios (13-1600), a characteristic signature of the Bayan Obo deposit. Two zircon grains yielded concordant 206Pb/238U ages (1.27?±?0.11?Ga?~?1.42?±?0.18?Ga) and 208Pb/232Th age (1.26?±?0.20?Ga) with calcite inclusions, indicating that the Wu dyke was emplaced at ca. 1.34?Ga, which coincides with a worldwide generation of Mesoproterozoic kimberlites, lamprophyres, carbonatites, and anorogenic magmatism. 3) Hydrothermal zircons with Caledonian and Triassic ages. The Caledonian zircon has 206Pb/238U age of 381?±?4?Ma and 208Pb/232Th age of 367?±?14?Ma with dolomite inclusion. These evidences are consistent with multiple stages of mineralization, Mesoproterozoic calcite carbonatite magmatism interacted by protracted fluxing of subduction-released Caledonian fluids during the closure of the Palaeo-Asian Ocean, coupled with interaction with the mantle wedge and metasomatism of overlying sedimentary carbonate.
DS201802-0250
2018
Yang, X-Y.Liu, Y-L., Ling, M-X., Williams, I.S., Yang, X-Y., Wang, C.Y.The formation of the giant Bayan Obo REE Nb Fe deposit, North China, Mesoproterozoic carbonatite and overprinted Paleozoic dolomitization.Ore Geology Reviews, Vol. 92, pp. 73-83.Chinadeposit - Bayan Obo

Abstract: The Bayan Obo ore deposit in Inner Mongolia, North China, the largest-known rare earth element (REE) deposit in the world, is closely associated with carbonatite dykes. Scarce zircon grains, with a wide range of ages and diverse origins, have been extracted from the Wu dyke, a REE-enriched calcitic carbonatite dyke 2?km from the East Ore Body of the Bayan Obo deposit. Three zircon populations were identified based on ages and trace element compositions: 1) Captured zircons with Paleoproterozoic and Archean ages. These zircons have REE patterns and moderate Th/U ratios similar to zircon with silicate inclusions from basement igneous rocks, which have been recognized as contaminants from wall rocks. 2) Carbonatite magmatic zircons with Mesoproterozoic ages. These zircons have high to extremely high Th/U ratios (13-1600), a characteristic signature of the Bayan Obo deposit. Two zircon grains yielded concordant 206Pb/238U ages (1.27?±?0.11?Ga?~?1.42?±?0.18?Ga) and 208Pb/232Th age (1.26?±?0.20?Ga) with calcite inclusions, indicating that the Wu dyke was emplaced at ca. 1.34?Ga, which coincides with a worldwide generation of Mesoproterozoic kimberlites, lamprophyres, carbonatites, and anorogenic magmatism. 3) Hydrothermal zircons with Caledonian and Triassic ages. The Caledonian zircon has 206Pb/238U age of 381?±?4?Ma and 208Pb/232Th age of 367?±?14?Ma with dolomite inclusion. These evidences are consistent with multiple stages of mineralization, Mesoproterozoic calcite carbonatite magmatism interacted by protracted fluxing of subduction-released Caledonian fluids during the closure of the Palaeo-Asian Ocean, coupled with interaction with the mantle wedge and metasomatism of overlying sedimentary carbonate.
DS200612-1552
2005
Yang, X-Z.Xia, Q-K., Sheng, Y-M., Yang, X-Z., Yu, H-M.Heterogeneity of water in garnets from UHP eclogites, eastern Dabie Shan, China.Chemical Geology, Vol. 224, 4, Dec. 20, pp. 237-246.ChinaUHP, Bixiling
DS2002-1760
2002
Yang, Y.Yang, Y., Liu, M.Deformation of convergent plates. Evidence from discrepancies between GPS velocities and rigid plate motions.Geophysical Research Letters, Vol. 29,10,May15,pp.110-MantleTectonics
DS200812-1294
2008
Yang, Y.Yang, Y., Forsyth, D.W.Attenuation in the upper mantle beneath southern California: physical state of the lithosphere and asenthosphere.Journal of Geophysical Research, Vol. 113, B03308.United States, CaliforniaTectonics
DS200812-1295
2008
Yang, Y.Yang, Y., Li, A., Ritzwoller, M.H.Crustal and uppermost mantle structure in southern Africa revealed from ambient noise and teleseismic tomography.Geophysical Journal International, In Press available.Africa, South AfricaGeophysics - seismics
DS200812-1296
2008
Yang, Y.Yang, Y., Li, A., Ritzwoller, M.H.Crustal and uppermost mantle structure in southern Africa revealed from ambient noise and teleseismic tomography.Geophysical Journal International, Vol. 174, 1, pp. 235-248.Africa, South AfricaGeophysics - seismics
DS200812-1297
2008
Yang, Y.Yang, Y., Li, A., Ritzwoller, M.H.Crustal and uppermost mantle structure in southern Africa revealed from ambient noise and teleseismic tomography.Geophysical Journal International, Vol. 174, pp. 235-248.Africa, South AfricaTomography
DS200912-0050
2009
Yang, Y.Bensen, G.D., Ritzwoller, M.H., Yang, Y.A 3 D shear velocity model of the crust and uppermost mantle beneath the United States from ambient seismic noise.Geophysical Journal International, Vol. 177, 3, pp. 1177-1196.United StatesGeophysics - seismics
DS200912-0835
2008
Yang, Y.Yang, Y., Ritzwoller, M.H., Lin, F.C., Moshetti, M.P., Shapiro, N.M.Structure of the upper crust and uppermost mantle beneath the western United States revealed by ambient noise and earthquake tomography.Journal of Geophysical Research, Vol. 113, B12, B12310.United StatesGeophysics - seismics
DS201012-0515
2010
Yang, Y.Moschetti, M.P., Rotzwoller, M.H., Lin, F-C., Yang, Y.Crustal shear wave velocity structure of the western United States inferred from ambient seismic noise and earthquake data.Journal of Geophysical Research, Vol. 115, B10 B10306.United StatesGeophysics - seismics
DS201112-0234
2011
Yang, Y.Dai, L-Q., Zhao, Z-F., Zheng, Y-F., Li, Q., Yang, Y., Dai, M.Zircon Hf-O isotope evidence for crust mantle interaction during continental deep subduction.Earth and Planetary Science Letters, Vol. 308, 1-2, pp. 229-244.MantleSubduction
DS201112-0603
2011
Yang, Y.Lin, F-C., Ritzwoller, M.H., Yang, Y., Moschetti, M.P., Fouch, M.J.Complex and variable crustal and uppermost mantle seismic anisotropy in the western United States.Nature Geoscience, Vol. 4, pp. 55-71.MantleTomography
DS201312-0009
2013
Yang, Y.Afonso, J.C., Fullea, J., Connolly, J., Rawlinson, N., Yang, Y., Jones, A.G.Multi observable thermochemical tomography: a new framework in integrated studies of the lithosphere.Goldschmidt 2013, AbstractMantleGeothermometry
DS201312-0347
2012
Yang, Y.Guo, S., Ye, K., Wu, Y., Chen, Y., Yang, Y., Zhang, L., Liu, J., Mao, Q., Ma, Y.A potential method to confirm the previous existence of lawsonite in eclogite: the mass imbalance of Sr and LREEs in multi stage epidote ( Ganghe, Dabie UHP terrane).Journal of Metamorphic Gology, Vol. 31, 4, pp. 415-435.ChinaUHP
DS201709-2077
2017
Yang, Y.Ying, Y., Chen, W., Lu, J., Jiang, S-Y., Yang, Y.In situ U-Th-Pb ages of the Miaoya carbonatite complex in the South Qinling orogenic belt, central China.Lithos, in press available, 57p.Chinacarbonatite - Miaoya

Abstract: The Miaoya carbonatite complex in the South Qinling orogenic belt hosts one of the largest rare earth element (REE)-Nb deposits in China that is composed of carbonatite and syenite. The emplacement age of the complex and the geochronological relationship between the carbonatite and syenite have long been debated. In this study, in situ U-Th-Pb ages have been obtained for the constituent minerals zircon, monazite and columbite from carbonatite and syenite of the Miaoya complex, together with their chemical and isotopic compositions. In situ trace element compositions for zircon from carbonatite and syenite are highly variable. The zircon displays slightly heavy REE (HREE)-enriched chondrite-normalized patterns with no Eu anomaly and various light REE (LREE) contents. In situ Th-Pb dating for zircon from the Miaoya complex by laser ablation ICP-MS yields ages of 442.6 ± 4.0 Ma (n = 53) for syenite and 426.5 ± 8.0 Ma (n = 23) for carbonatite. Monazite from carbonatite and syenite shows similar chondrite-normalized REE patterns and yields a consistent Th-Pb age of ~ 240 Ma. Based on petrographic and chemical composition, columbite from the carbonatite can be identified into two groups. The columbite dispersed within carbonatite is characterized by slightly LREE-enriched chondrite-normalized REE patterns, whereas columbite associated with apatite is characterized by LREE-depleted trends. Columbite has been further determined to have a weighted mean 206Pb/238U age of 232.8 ± 4.5 Ma (n = 9) using LA-ICP-MS. Detailed geochronological and chemical investigations suggest that there were two major episodes of magmatic/metasomatic activities in the formational history of the Miaoya carbonatite complex. The early alkaline magmatism emplaced in the Silurian was related to the opening of the Mianlue Ocean, whereas the late metasomatism or hydrothermal overprint occurred during the Triassic South Qinling orogeny. The latter serves as the major ore formation period for both REE (e.g., monazite) and Nb (e.g., columbite).
DS201805-0979
2018
Yang, Y.Song, W., Xi, C., Smith, M.P., Chakhmouradian, A.R., Brenna, M., Kynicky, J., Chen, W., Yang, Y., Tang, H.Genesis of the world's largest rare earth element deposit, Bayan Obo, China: protracted mineralization evolution over ~ 1.b.y.Geology, Vol. 48, 4, pp. 323-326.Chinadeposit - Bayan Obo

Abstract: The unique, giant, rare earth element (REE) deposit at Bayan Obo, northern China, is the world’s largest REE deposit. It is geologically complex, and its genesis is still debated. Here, we report in situ Th-Pb dating and Nd isotope ratios for monazite and Sr isotope ratios for dolomite and apatite from fresh drill cores. The measured monazite ages (361-913 Ma) and previously reported whole-rock Sm-Nd data show a linear relationship with the initial Nd isotope ratio, suggesting a single-stage evolution from a Sm-Nd source that was formed before 913 Ma. All monazites show consistent eNd(1.3Ga) values (0.3 ± 0.6) close to those of the adjacent 1.3 Ga carbonatite and mafic dikes. The primary dolomite and apatite show lower 87Sr/86Sr ratios (0.7024-0.7030) than the recrystallized dolomite (0.7038-0.7097). The REE ores at Bayan Obo are interpreted to have originally formed as products of ca. 1.3 Ga carbonatitic magmatism and to have undergone subsequent thermal perturbations induced by Sr-rich, but REE-poor, metamorphic fluids derived from nearby sedimentary rocks.
DS202009-1623
2019
Yang, Y.Deng, L-P., Liu, Y-C., Yang, Y., Groppo, C., Rolfo, F., Gu, X-F.Anatexis of high-T eclogites in the Dabie orogen triggered by exhumation and post-orogenic collapse.European Journal of Mineralogy, Vol. 31, pp. 889-803. pdfChinaeclogite

Abstract: A combined study of detailed petrographic observation, mineral chemistry analysis and phase equilibrium modeling indicates that the high-temperature eclogites from the Dabie orogen, central China, experienced two episodes of anatexis: the first is phengite dehydration melting during the exhumation of deeply subducted slices, and the second is heating melting related to the post-orogenic collapse. Petrographic evidence and clues of the anatectic events include biotite + plagioclase + garnet ± amphibole intergrowth in matrix and biotite + plagioclase intergrowth within amphibole porphyroblast. Pressure-temperature (P-T) pseudosection and modal variation diagram indicate that the biotite + plagioclase + garnet ± amphibole in matrix was formed by the reactions phengite + clinopyroxene + quartz = melt + sanidine + garnet + plagioclase and later melt + sanidine + garnet = biotite + plagioclase, while the biotite + plagioclase intergrowths within poikiloblastic amphibole were formed by the reaction amphibole + muscovite + epidote = biotite + plagioclase + melt. In addition, the combination of petrological observations and P-T estimates suggests that the first melting event occurred at the late Triassic, while the second is related to the early Cretaceous mountain-root removal and subsequent asthenospheric upwelling and heat input. As the P-T paths of high-temperature/ultrahigh-pressure rocks have high probabilities to cross-cut phengite-melting curves, phengite melting during decompression may be a common process in these rocks. Moreover, the coexistence of multiple episodes of anatexis in a single tectonic slice suggests caution when identifying and dating partial melting in high-temperature/(ultra)high-pressure rocks.
DS200712-1230
2007
Yang, Y.H.Zhang, R.Y., Liou, J.G., Zheng, J.P., Yang, Y.H.Mineral REE ad Lu Hf isotope geochemistry of zircon in the mantle - derived eclogite from Donghai the Sulu UHP terrane: new constraints for the origin of eclogite.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p. 250.ChinaGeochronology
DS200712-1231
2007
Yang, Y.H.Zhang, R.Y., Liou, J.G., Zheng, J.P., Yang, Y.H.Mineral REE ad Lu Hf isotope geochemistry of zircon in the mantle - derived eclogite from Donghai the Sulu UHP terrane: new constraints for the origin of eclogite.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p. 250.ChinaGeochronology
DS200812-1312
2008
Yang, Y.H.Zhang, R.Y., Pan, Y.M., Yang, Y.H., Li, T.F., Liou, J.G., Yang, J.S.Chemical composition and ultrahigh P metamorphism of garnet peridotites from the Sulu UHP terrane, China: investigation of major, trace elements and Hf isotopesChemical Geology, in press available,ChinaUHP
DS200812-1313
2008
Yang, Y.H.Zhang, R.Y., Pan, Y.M., Yang, Y.H., Li, T.F., Liou, J.G., Yang, J.S.Chemical composition and ultrahigh P metamorphism of garnet peridotites from the Sulu UHP terrane, China: investigation of major trace elements and Hf isotopes.Chemical Geology, Vol. 255, 1-2, Sept. 30, pp. 250-264.ChinaUHP
DS2003-1524
2003
Yang, Y.S.Yang, Y.S., Wooden, J.L., Wu. C.L., Liu, F.L., Xu. ZQ, Shi, R.D., Katayama, I.SHRIMP U Pb dating of coesite bearing zircon from the ultrahigh pressureJournal of Metamorphic Geology, Vol. 21, 6, pp. 551-60.ChinaUHP
DS200412-2174
2003
Yang, Y.S.Yang, Y.S., Wooden, J.L., Wu,C.L., Liu, F.L., Xu,ZQ, Shi, R.D., Katayama, I., Liou, J.G., Maruyama, S.SHRIMP U Pb dating of coesite bearing zircon from the ultrahigh pressure metamorphic rocks, Sulu terrane, east China.Journal of Metamorphic Geology, Vol. 21, 6, pp. 551-60.ChinaUHP
DS200612-1547
2006
Yang, Y-H.Wu, F-Y., Walker, R.J., Yang, Y-H., Yuan, H-L., Yang, J-H.The chemical temporal evolution of lithospheric mantle underlying the North Chin a Craton.Geochimica et Cosmochimica Acta, Vol. 70, 19, pp. 5013-5034.ChinaDeposit - Tieling, Fuxian, Mengyin - geochemistry -SCLM
DS200612-1548
2006
Yang, Y-H.Wu, F-Y., Yang, Y-H., Xie, L-W., Yang, J-H., Xu, P.Hf isotopic compositions of the standard zircons and baddeleyites used in U Pb geochronology.Chemical Geology, Vol. 234, 1-2, Oct 30, pp. 105-126.ChinaUHP, geochronology
DS200912-0114
2009
Yang, Y-H.Chu, Z-Y., Wu, F-Y., Walker, R.J., Rudnick, R.L., Pitcher, L., Puchtel, I.S., Yang, Y-H., Wilde, S.A.Temporal evolution of the lithospheric mantle beneath the North Chin a Craton.Journal of Petrology, Vol. 50, 10, pp. 1857-1898.ChinaGeodynamics
DS200912-0836
2009
Yang, Y-H.Yang, Y-H., Wu, F-Y., Wilde, S.A., Liu, X-M., Zhang, Y-B., Xie, L-W., Yang, J-H.In in situ perovskite Sr Nd isotopic constraints on the petrogenesis of the Ordovician Mengyin kimberlites in North Chin a craton.Chemical Geology, Vol. 264, 1-4, pp. 24-42.ChinaDeposit - Mengyin
DS200912-0866
2009
Yang, Y-H.Zhu-Yin Chu, Wu, F-Y., Walker, R.J., Rudnick, R.L., Pitcher, L., Puchtel, I.S., Yang, Y-H., Wilde, S.A.Temporal evolution of the lithospheric mantle beneath the eastern north Chin a craton.Journal of Petrology, Vol. 50, 10, October, pp. 1857-1898.ChinaTectonics
DS201012-0765
2010
Yang, Y-H.Su, B-X., Zhang, H-F., Sakyi, P.A., Yang, Y-H., Ying, J-F., Tang, Y-J., Qin, K-Z., Xiao, Y., Zhao, Mao, MaThe origin of spongy texture in minerals of mantle xenoliths from the western Qinling, central China.Contributions to Mineralogy and Petrology, in press available, 18p.ChinaXenoliths
DS201012-0766
2010
Yang, Y-H.Su, B-X., Zhang, H-F., Sakyi, P.A., Ying, J-F., Tang, Y-J., Yang, Y-H., Qin, K-Z., Xiao, Y., Zhao, X-M.Compositionally stratified lithosphere and carbonatite metasomatism recorded in mantle xenoliths from the Western Qinling (Central China).Lithos, Vol. 116, pp. 111-128.ChinaCarbonatite
DS201012-0861
2010
Yang, Y-H.Wu, F.Y., Yang, Y-H., Mitchell, R.H., Li, J-H., Yang, J-H., Zhang, Y-B.In situ U Pb age determination and Nd isotopic analysis of perovskites from kimberlites in southern Africa and Somerset Island, Canada.Lithos, Vol. 115, pp. 205-222.Canada, Nunavut, Africa, South AfricaGeochronology
DS201112-0594
2011
Yang, Y-H.Li, Q., Wu, F-Y., Li, X-H., Qiu, Z-L., Yang, Y-H., Tang, G-Q.Precisely dating Paleozoic kimberlites in the North Chin a craton and Hf isotopic constraints on the evolution of the subcontinental lithospheric mantle.Lithos, Vol. 126, pp. 127-134.ChinaMengyin, Fuxian
DS201112-0595
2011
Yang, Y-H.Li, Q-L., Wu, F-Y., Li, X-H., Qiu, Z-L., Liu, Y., Yang, Y-H., Tang, G-Q.Precise age determin ation of the Paleozoic kimberlites in North Chin a craton and Hf isotopic constraint on the evolution of its subcontinental lithospheric mantle.Goldschmidt Conference 2011, abstract p.1316.ChinaMengyin, Fuxian
DS201112-1122
2011
Yang, Y-H.Wu, F-Y., Yang, Y-H.,Li, Q-L., Mitchell, R.H., Dawson, J.B., Brandl, G., Yuhara, M.In situ determination of U-Pb ages and Sr-Nd-Hf isotopic constraints on the petrogenesis of the Phalaborwa carbonatites complex, South Africa.Lithos, Vol. 127, 1-2, pp. 309-322.Africa, South AfricaCarbonatite, geochronology, Palaborwa
DS201212-0797
2013
Yang, Y-H.Xu, W-L., Zhou, Q-J., Pei, F-P., Gao, S., Li, Q-L., Yang, Y-H.Destructive of the North Chin a craton: delamin ation or thermal/chemical erosion? Mineral chemistry and oxygen isotope insights from websterite xenoliths.Gondwana Research, Vol. 23, 1, pp. 119-129.ChinaCraton, destruction
DS201212-0812
2012
Yang, Y-H.Zhang, H-F., Yang,Y-H., Santosh, M., Zhao, X-M., Ying, J-F., Xiao, Y.Evolution of the Archean and Paleoproterozoic lower crust beneath the Trans-North Chin a Orogen and the western block of the north Chin a craton.Gondwana Research, Vol. 22, 1, pp. 73-85.ChinaGeochronology, tectonics, cratons
DS201312-0984
2013
Yang, Y-H.Wu, F-Y., Mitchell, R.H., Li, Q-L., Liu, C-Z., Yang, Y-H.In situ U-Pb age determination and Sr-Nd isotopic analysis of perovskite from the Premier ( Cullinan) kimberlite, South Africa. ~1150Chemical Geology, Vol. 353, pp. 83-95.Africa, South AfricaGeochronology
DS201312-0986
2013
Yang, Y-H.Wu,F-Y., Arzamastsev, A.A., Mitchell, R.H., Li, Q-L., Sun, J., Yang, Y-H., Wang, R-C.Emplacement age and Sr-Nd isotopic compositions of the AfrikAnd a alkaline ultramafic complex, Kola Peninsula, Russia.Chemical Geology, Vol. 353, pp. 210-229.Russia, Kola PeninsulaAfrikanda Complex
DS201412-0897
2014
Yang, Y-H.Sun, J., Liu, C-Z., Tappe, S., Kostrovitsky, S.I., Wu, F-Y., Yakovlev, D., Yang, Y-H., Yang, J-H.Repeated kimberlite magmatism beneath Yakutia and its relationship to Siberian flood volcanism: insights from in situ U-Pb and Sr-Nd perovskite isotope analysis.Earth and Planetary Science Letters, Vol. 404, Oct. pp. 283-295.Russia, YakutiaKimberlite magmatism
DS201703-0440
2017
Yang, Y-H.Wu, F-Y.,Mitchell, R.H., Li, Q-L., Zhang, C., Yang, Y-H.Emplacement age and isotopic composition of the Prairie Lake carbonatite complex, northwestern Ontario, Canada.Geological Magazine, Vol. 154, 2, pp. 217-236.Canada, OntarioCarbonatite

Abstract: Alkaline rock and carbonatite complexes, including the Prairie Lake complex (NW Ontario), are widely distributed in the Canadian region of the Midcontinent Rift in North America. It has been suggested that these complexes were emplaced during the main stage of rifting magmatism and are related to a mantle plume. The Prairie Lake complex is composed of carbonatite, ijolite and potassic nepheline syenite. Two samples of baddeleyite from the carbonatite yield U-Pb ages of 1157.2±2.3 and 1158.2±3.8 Ma, identical to the age of 1163.6±3.6 Ma obtained for baddeleyite from the ijolite. Apatite from the carbonatite yields the same U-Pb age of ~1160 Ma using TIMS, SIMS and laser ablation techniques. These ages indicate that the various rocks within the complex were synchronously emplaced at about 1160 Ma. The carbonatite, ijolite and syenite have identical Sr, Nd and Hf isotopic compositions with a 87Sr/86Sr ratio of ~0.70254, and positive eNd(t)1160 and eHf(t)1160 values of ~+3.5 and ~+4.6, respectively, indicating that the silicate and carbonatitic rocks are co-genetic and related by simple fractional crystallization from a magma derived from a weakly depleted mantle. These age determinations extend the period of magmatism in the Midcontinent Rift in the Lake Superior area to 1160 Ma, but do not indicate whether the magmatism is associated with passive continental rifting or the initial stages of plume-induced rifting.
DS201709-2061
2017
Yang, Y-H.Sun, J., Liu, C-Z., Kostrovisky, S.I., Wu, F-Y., Yang, J-H., Chu, Z., Yang, Y-H.Constraints from peridotites in the Obnazhennaya kimberlite.Goldschmidt Conference, abstract 1p.Russiadeposit - Obnazhennaya

Abstract: The characteristics of the sub-continental lithospheric mantle (SCLM) post-date the Siberian plume event (250 Ma) is still unclear; nearly all published data for mantle xenoliths are from a single kimberlite erupt before he Siberian plume (Udachnaya). We report major elements of the whole rock, trace elements data of clinopyroxene and Re-Os isotope and PGE concentration of mantle xenoliths from the Obnazhennaya kimberlite pipe (160 Ma). The Obnazhennaya mantle xenoliths, including spinel harzburgites, spinel dunites, spinel lherzolites, spinel-garnet lherzolite. The spinel harzburgites and dunites have refractory compositions, with 0.23-1.35 wt.% Al2O3, 0.41-3.11 wt.% CaO and 0.00-0.09 wt.% TiO2. Clinopyroxenes in harzburgites and dunites have lower Na2O but higher Cr2O3 contents. Modeling of the Y and Yb contents in clinopyroxenes indicates that the spinel harzburgites and dunites have been subjected to ca. 12-17% degrees of partial melting. The spinel harzburgites and dunites have 187Os/188Os of 0.11227-0.11637, giving a TRD age of 1.6-2.2 Ga. This suggests that old cratonic mantle still existed beneath the Obnazhennaya. In contrast, the lherzolites (both spinel- and spinel-garnet-) have more fertile compositions, containing 2.16-6.55 wt.% Al2O3, 2.91-7.55 wt.% CaO and 0.04-0.15 wt.% TiO2. Both spinel and spinelgarnet lherzolites have more radiogenic 187Os/188Os ratios (0.11931-0.17627), enriched P-PGEs. The higher Al2O3 and Os content and depleted IPGE character of these lherzolites suggest that they were not juvenile mantle accreted by Siberian mantle plume but the refertilized ancient mantle. Therefore, our result suggest that the cratonic mantle beneath the Obnazhennaya has not been replaced by juvenile mantle during the Siberian mantle plume.
DS201709-2062
2017
Yang, Y-H.Sun, J., Liu, C-Z., Kostrovisky, S.I., Wu, F-Y., Yang, J-H., Chu, Z., Yang, Y-H.Composition of the lithospheric mantle in the northern Siberian craton: constraints from the peridotites in the Obnazhennaya kimberlite.Goldschmidt Conference, abstract 1p.Russia, Siberiadeposit - Obnazhennaya

Abstract: The characteristics of the sub-continental lithospheric mantle (SCLM) post-date the Siberian plume event (250 Ma) is still unclear; nearly all published data for mantle xenoliths are from a single kimberlite erupt before he Siberian plume (Udachnaya). We report major elements of the whole rock, trace elements data of clinopyroxene and Re-Os isotope and PGE concentration of mantle xenoliths from the Obnazhennaya kimberlite pipe (160 Ma). The Obnazhennaya mantle xenoliths, including spinel harzburgites, spinel dunites, spinel lherzolites, spinel-garnet lherzolite. The spinel harzburgites and dunites have refractory compositions, with 0.23-1.35 wt.% Al2O3, 0.41-3.11 wt.% CaO and 0.00-0.09 wt.% TiO2. Clinopyroxenes in harzburgites and dunites have lower Na2O but higher Cr2O3 contents. Modeling of the Y and Yb contents in clinopyroxenes indicates that the spinel harzburgites and dunites have been subjected to ca. 12-17% degrees of partial melting. The spinel harzburgites and dunites have 187Os/188Os of 0.11227-0.11637, giving a TRD age of 1.6-2.2 Ga. This suggests that old cratonic mantle still existed beneath the Obnazhennaya. In contrast, the lherzolites (both spinel- and spinel-garnet-) have more fertile compositions, containing 2.16-6.55 wt.% Al2O3, 2.91-7.55 wt.% CaO and 0.04-0.15 wt.% TiO2. Both spinel and spinelgarnet lherzolites have more radiogenic 187Os/188Os ratios (0.11931-0.17627), enriched P-PGEs. The higher Al2O3 and Os content and depleted IPGE character of these lherzolites suggest that they were not juvenile mantle accreted by Siberian mantle plume but the refertilized ancient mantle. Therefore, our result suggest that the cratonic mantle beneath the Obnazhennaya has not been replaced by juvenile mantle during the Siberian mantle plume.
DS201803-0488
2018
Yang, Y-H.Yang, Y-H., Wu, F-Y., Yang, J-H., Mitchell, R.H., Zhao, Z-F., Xie, L-W., Huang, C., Ma, Q., Yang, M., Zhao, H.U-Pb age determination of schorlomite garnet by laser ablation inductively coupled plasma mass spectrometry. Magnet Cove, Fanshan, Ozernaya, Alno, Prairie LakeJournal of Analytical At. Spectrometry, Vol. 33, pp. 231-239.United States, Arkansas, China, Hebei, Russia, Kola Peninsula, Europe, Sweden, Canada, Ontariogeochronology

Abstract: We report the first U-Pb geochronological investigation of schorlomite garnet from carbonatite and alkaline complexes and demonstrate its applicability for U-Pb age determination using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) due to its relatively high U and Th abundances and negligible common Pb content. The comparative matrix effects of laser ablation of zircon and schorlomite are investigated and demonstrate the necessity of a suitable matrix-matched reference material for schorlomite geochronology. Laser-induced elemental fractional and instrumental mass discrimination were externally-corrected using an in house schorlomite reference material (WS20) for U-Pb geochronology. In order to validate the effectiveness and robustness of our analytical protocol, we demonstrate the veracity of U-Pb age determination for five schorlomite samples from: the Magnet Cove complex, Arkansas (USA); the Fanshan ultrapotassic complex, Hebei (China); the Ozernaya alkaline ultramafic complex, Kola Peninsula (Russia); the Alnö alkaline-rock carbonatite complex (Sweden); and the Prairie Lake carbonatite complex, Ontario (Canada). The schorlomite U-Pb ages range from 96 Ma to 1160 Ma, and are almost identical to ages determined from other accessory minerals in these complexes and support the reliability of our analytical protocol. Schorlomite garnet U-Pb geochronology is considered to be a promising new technique for understanding the genesis of carbonatites, alkaline rocks, and related rare-metal deposits.
DS201810-2360
2018
Yang, Y-H.Nasdala, L., Corfu, F., Schoene, B., Tapster, S.R., Wall, C.J., Schmitz, M.D., Ovtcharova, M., Schaltegger, U., Kennedy, A.K., Kronz, A., Reiners, P.W., Yang, Y-H., Wu, F-Y., Gain, S.E.M., Griffin, W.L., Szymanowski, D., Chanmuang, C., Ende, N.M., ValleyGZ7 and GZ8 - two zircon reference materials for SIMS U-Pb geochronology.Geostandards and Geoanalytical Research, http://orchid.org/0000-0002-2701-4635 80p.Asia, Sri Lankageochronology

Abstract: Here we document a detailed characterization of two zircon gemstones, GZ7 and GZ8. Both stones had the same mass at 19.2 carats (3.84 g) each; both came from placer deposits in the Ratnapura district, Sri Lanka. The U-Pb data are in both cases concordant within the uncertainties of decay constants and yield weighted mean ²°6Pb/²³8U ages (95% confidence uncertainty) of 530.26 Ma ± 0.05 Ma (GZ7) and 543.92 Ma ± 0.06 Ma (GZ8). Neither GZ7 nor GZ8 have been subjected to any gem enhancement by heating. Structure-related parameters correspond well with the calculated alpha doses of 1.48 × 10¹8 g?¹ (GZ7) and 2.53 × 10¹8 g?¹ (GZ8), respectively, and the (U-Th)/He ages of 438 Ma ± 3 Ma (2s) for GZ7 and 426 Ma ± 9 Ma (2s) for GZ8 are typical of unheated zircon from Sri Lanka. The mean U concentrations are 680 µg g?¹ (GZ7) and 1305 µg g?¹ (GZ8). The two zircon samples are proposed as reference materials for SIMS (secondary ion mass spectrometry) U-Pb geochronology. In addition, GZ7 (Ti concentration 25.08 µg g?¹ ± 0.18 µg g?¹; 95% confidence uncertainty) may prove useful as reference material for Ti-in-zircon temperature estimates.
DS201912-2835
2019
Yang, Y-H.Yang, Y-H., Wu, F-Y., Qiu-Li, L., Rojas-Agramonte, Y., Yang, J-H., Yang, L., Ma, Q., Xie, L-W., Huang, C., Fan, H-R., Zhao, Z-F., Xu, C.In situ U-Th-Pb dating and Sr-Nd isotope analysis of bastnasite by LA-(MC)-ICP-MS.Geostandards and Geoanalltical Research, Vol. 43, 3, pp. 543-565.China, Europe, Sweden, Asia, Mongolia, United States, Africa, Malawi, MadagascarREE

Abstract: Bastnäsite is the end member of a large group of carbonate-fluoride minerals with the common formula (REE) CO3F•CaCO3. This group is generally widespread and, despite never occurring in large quantities, represents the major economic light rare earth element (LREE) mineral in deposits related to carbonatite and alkaline intrusions. Since bastnäsite is easily altered and commonly contains inclusions of earlier-crystallised minerals, in situ analysis is considered the most suitable method to measure its U-Th-Pb and Sr-Nd isotopic compositions. Electron probe microanalysis and laser ablation (multi-collector) inductively coupled plasma-mass spectrometry of forty-six bastnäsite samples from LREE deposits in China, Pakistan, Sweden, Mongolia, USA, Malawi and Madagascar indicate that this mineral typically has high Th and LREE and moderate U and Sr contents. Analysis of an in-house bastnäsite reference material (K-9) demonstrated that precise and accurate U-Th-Pb ages could be obtained after common Pb correction. Moreover, the Th-Pb age with its high precision is preferable to the U-Pb age because most bastnäsites have relatively high Th rather than U contents. These results will have significant implications for understanding the genesis of endogenous ore deposits and formation processes related to metallogenic geochronology research.
DS1993-1789
1993
Yang, Z.Yan Chen, Courtillot, V., Cogne, J-P., Besse, J., Yang, Z., Enkin, R.The configuration of Asia prior to the collision of India: Cretaceous paleomagnetic constraints.Journal of Geophysical Research, Vol. 98, No. B 12, December 10, pp. 21, 927-21, 941.GlobalPaleomagnetics
DS200612-0603
2006
Yang, Z.Hou, Z., Tian, S., Yuan, Z., Xie, Y., Yin, S., Yi, L., Fei, H., Yang, Z.The Himalayan collision zone carbonatites in western Sichuan, SW China: petrogenesis, mantle source and tectonic implication.Earth and Planetary Science Letters, in pressAsia, ChinaCarbonatite
DS200612-1565
2006
Yang, Z.Yang, Z., Woolley, A.Carbonatites in China: a review.Journal of Asian Earth Sciences, Vol. 27, 5, Sept. 15, pp. 559-750.ChinaCarbonatite
DS200712-0133
2007
Yang, Z.Campbell, L.S., Wall, F., Henderson, P., Zhang, P., Tao, K., Yang, Z.The character and context of zircons from the Bayan Obo Fe Nb REE deposit, Inner Mongolia.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p. 97-98.Asia, MongoliaCarbonatite
DS200712-0134
2007
Yang, Z.Campbell, L.S., Wall, F., Henderson, P., Zhang, P., Tao, K., Yang, Z.The character and context of zircons from the Bayan Obo Fe Nb REE deposit, Inner Mongolia.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p. 97-98.Asia, MongoliaCarbonatite
DS200912-0313
2009
Yang, Z.Hou, Z., Tian, S., Xie, Y., Yang, Z., Yuan, Z., Yin, S., Yi, L., Fei, H., Zou, T., Bai, G., Li, X.The Himalayan Mianning Dechang REE belt associated with carbonatite alkaline complexes eastern Indo Asian collision zone, SW China.Ore Geology Reviews, Vol. 36, 1-3, pp. 65-89.ChinaCarbonatite
DS201201-0836
2012
Yang, Z.Chen, W-P., Hung, S-H., Tseng, T-L., Brudzinski, M., Yang, Z., Nowack, R.L.Rheology of the continental lithosphere: progress and new perspectives.Gondwana Research, Vol. 21, 1, pp. 4-18.MantleGeodynamics
DS201312-0047
2013
Yang, Z.Bader, T., Ratschbacher, L., Franz, L., Yang, Z., Hofmann, M., Linneman, U., Yuan, H.The heart of Chin a revisited. 1. Proterozoic tectonics of the Qin Mountains in the core of supercontinent Rodinia.Tectonics, Vol. 32, 3, pp. 661-687.ChinaMagmatism - Dabie orogen
DS201508-0366
2015
Yang, Z.Liu, Y., Chen, Z., Yang, Z., Sun, X., Zhu, Z., Zhang, Q.Mineralogical and geochemical studies of brecciated ores in the Dalucao REE deposit, Sichuan Province, southwestern China.Ore Geology Reviews, Vol. 70, pp. 613-636.ChinaCarbonatite
DS201809-2054
2018
Yang, Z.Lawley, C.J.M., Kjarsgaard, B.A., Jackson, S.E., Yang, Z., Petts, D.C.Olivine and clinopyroxene mantle xenocryst geochemistry from the Kirkland Lake kimberlite field, Ontario.Geological Survey of Canada, Open File 8376, 9p.Canada, Ontariogeochemistry
DS201810-2342
2018
Yang, Z.Lawley, C., Kjarsgaard, B., Jackson, S., Yang, Z., Petts, D., Roots, E.Trace metal and isotopic depth profiles through the Abitibi. Kirkland Lake kimberlite field.Lithos, Vol. 314-315, pp. 520-533.Canada, Ontariodeposit - Kirkland Lake

Abstract: Geophysical imaging of trans-lithospheric structures provide a spatial link between ore deposits in the crust and the underlying cratonic mantle. However, the deep lithosphere's role in ore deposit genesis remains poorly understood because remotely acquired datasets do not provide any direct constraints on the behaviour of ore elements within these mantle-roots. The abundance and behaviour of ore elements governs the metallic endowment of the cratonic mantle and the economic potential of mantle-derived magmas. Herein we present in situ electron probe microanalysis (EPMA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) geochemical datasets for clinopyroxene and olivine mantle xenocrysts from the Jurassic Kirkland Lake kimberlite field, Abitibi greenstone belt, Canada. We specifically focus on unconventional trace elements, including ore elements with chalcophile and/or siderophile affinities (Ag-As-Au-Bi-Cu-Mo-Pb-Pt-Pd-Sb-Se-Sn-Te-W-Zn). Robust principal component analysis suggests that low-T, large-ion lithophile element alteration (Ba-Sr), which likely occurred during kimberlite emplacement, represents the largest source of variance for the xenocryst dataset. PT-dependent element partitioning during sub-solidus equilibration represents the second most important control on olivine and clinopyroxene chemistry. We demonstrate that least-altered, high-PT mantle silicates are, in fact, a significant mineral host for a range of ore elements (Cu-Zn ± Ag ± As ± Se ± Sn ± Mo) within equilibrated, garnet peridotite at depth (70-190 km). Statistical analysis of the raw, individual mass sweeps for each LA-ICP-MS signal suggest that the most abundant ore elements (Cu-Zn) occur predominantly as PT-dependent substitution reactions with the dominant mineral-forming elements, rather than as inclusions. A subset of high-PT olivine (160-180 km) yields Fe-Ni-S-poor and Na (Au ± Pt ± Pd)-rich compositions, which may reflect metasomatism, sulphide segregation and trapping of precious metal-bearing fluids at the base of the lithosphere. These anomalous mantle fragments possibly represent the first, direct sampling of precious metal-modified mantle peridotite beneath the Abitibi. Mid-PT olivine xenocrysts (70-120 km), which yield Mg-rich and high field-strength element-poor compositions, document a highly melt-depleted segment of mantle peridotite coincident with and below a shallow-dipping, low-seismic-velocity anomaly and conductive feature of the Kirkland Lake mid-lithosphere at 70-100 km. We speculate that the trace element signature of mid-PT xenocrysts documents the re-distribution of high-charge and incompatible elements from refractory garnet peridotite to phlogopite- and/or amphibole-bearing peridotite with conductive metasomatic up-flow zones. The rapid, sub-solidus diffusion of elements at high-T suggest that these processes likely occurred during, and/or immediately preceding, kimberlite volcanism. New in situ Pb isotope analyses of clinopyroxene xenocrysts sampled from metasomatized, low-Al garnet peridotite, however, also document ancient metasomatic events that likely pre-date Jurassic kimberlitic volcanism by at least one billion years.
DS202007-1159
2020
Yang, Z.Li, W, Yang, Z., Chiaradia, M., Yong, L., Caho, Yu., Zhang, J.Redox state of southern Tibetan mantle and ultrapotassic magmas. Lhasa TerraneGeology, Vol. 48, 7, pp. 733-736. pdfAsia, Tibetalkaline rocks

Abstract: The redox state of Earth’s upper mantle in several tectonic settings, such as cratonic mantle, oceanic mantle, and mantle wedges beneath magmatic arcs, has been well documented. In contrast, oxygen fugacity (graphic) data of upper mantle under orogens worldwide are rare, and the mechanism responsible for the mantle graphic condition under orogens is not well constrained. In this study, we investigated the graphic of mantle xenoliths derived from the southern Tibetan lithospheric mantle beneath the Himalayan orogen, and that of postcollisional ultrapotassic volcanic rocks hosting the xenoliths. The graphic of mantle xenoliths ranges from ?FMQ = +0.5 to +1.2 (where ?FMQ is the deviation of log graphic from the fayalite-magnetite-quartz buffer), indicating that the southern Tibetan lithospheric mantle is more oxidized than cratonic and oceanic mantle, and it falls within the typical range of mantle wedge graphic values. Mineralogical evidence suggests that water-rich fluids and sediment melts liberated from both the subducting Neo-Tethyan oceanic slab and perhaps the Indian continental plate could have oxidized the southern Tibetan lithospheric mantle. The graphic conditions of ultrapotassic magmas show a shift toward more oxidized conditions during ascent (from ?FMQ = +0.8 to +3.0). Crustal evolution processes (e.g., fractionation) could influence magmatic graphic, and thus the redox state of mantle-derived magma may not simply represent its mantle source.
DS202002-0203
2020
Yang, Z-F.Liu, S., Fan, H-R., Groves, D.I., Yang, K-F, Yang, Z-F., Wang, Q-W.Multiphase carbonatite related magmatic and metasomatic processes in the genesis of the ore-hosting dolomite in the giant Bayan Obo REE-Nb-Fe deposit.Lithos, in press available, 96p. PdfChinacarbonatite

Abstract: The origin of dolomite that hosts the Bayan Obo REE-Nb-Fe deposit (57.4 % REE2O3, 2.16 % Nb2O5, and >1500 % iron oxides) has been controversial for decades, but it is integral to understanding of the genesis of this giant deposit. In this study, based on the textures and in situ major and trace element composition of its carbonates, the dolomite was proved to be initially generated from magnesio-ferro-carbonatite melts. It subsequently experienced magmatic-hydrothermal alteration and recrystallization in a low strain environment, caused by calcio-carbonatitic fluids, with formation of finer-grained dolomite, interstitial calcite and increasing amounts of associated fluorocarbonates. Available stable isotope analyses indicate that the recrystallized ore-hosting dolomite has higher d13C and d18O ratios compared to its igneous coarse-grained precursor. Rayleigh fractionation during the recrystallization process, rather than crustal contamination, played a major role in the highly-variable stable isotope composition of carbonates in the dolomite. Low-T alteration increased variability with apparently random increases in d18O within carbonates. The REE, Ba and Sr were added simultaneously with the elevated (La/Yb)cn from magnesio-ferro-carbonatite melts to calcio-carbonatitic fluids, and to carbonatite-derived aqueous fluids, through which extensive fluorine metasomatism and alkali alteration overlapped the recrystallization of the ore-hosting dolomite. Therefore, the multi-stage REE mineralization at Bayan Obo is closely related to metasomatism by calcio-carbonatitic fluids of previously-emplaced intrusive magnesio-ferro-carbonatite bodies during late evolution of the Bayan Obo carbonatite complex. Then, the ore-hosting dolomitic carbonatite was subjected to compressive tectonics during a Paleozoic subduction event, and suffered intense, largely brittle, deformation, which partially obscured the earlier recrystallization process. The complex, multi-stage evolution of the ore-hosting dolomite is responsible for the uniqueness, high grade and giant size of the Bayan Obo deposit, the world's largest single REE resource with million tonnes of REE oxides.
DS202011-2044
2020
Yang, Z-F.Hou, X-Z., Yang, Z-F., Wang, Z-J.The occurrence characteristics and recovery potential of middle-heavy rare earth elements in the Bayan Obo deposit, northern China.Ore Geology Reviews, Vol. 126, 103737, 13p. PdfChinaREE

Abstract: The Bayan Obo deposit is a world-class Fe-REE-Nb deposit, and its reserves of rare earth element (REE) resources rank the first over the world. In the face of the current situation of insufficient utilization rate of rare earth resources and scarcity of middle-heavy rare earth elements (M-HREE) resources, the Bayan Obo deposit with such a huge amount of M-HREE cannot be underestimated. In this paper, the occurrence characteristics of M-HREE in different types of iron ore in the Bayan Obo main ore body are studied by using field emission scanning electron microscope (FESEM), energy dispersive spectrometer (EDS) and advanced mineral identification and characterisation system (AMICS), and the enrichment mechanism is also discussed. The results show that both Sm and Y are the most abundant M-HREE in each type of iron ore in the main ore body, and the content of M-HREE accounts for 1.41%-5.57% of total REE, among which the content of M-HREE in aegirine type Nb-REE-Fe ore (824.47 ppm) and fluorite type Nb-REE-Fe ore (794.82 ppm) are higher, and the content of M-HREE in massive type Nb-REE-Fe ore is lower (318.49 ppm). The main minerals containing M-HREE are bastnasite, parisite, Huanghoite, monazite, aeschynite and fergusonite, among which the content of M-HREE in fergusonite and aeschynite are the highest. According to the characteristics of mineral paragenetic association of REE in this ore district, it is believed that the REE migrates mainly in many different forms of complexes. Heavy rare earth elements (HREE) mainly experienced carbonatite magmatism stage, sodium-fluorine metasomatism stage and late vein mineralization stage, and finally got enrichment.
DS201312-0992
2013
Yang, Z-j.Yang, Z-j., Liang, R., Zeng, X-q., Ge, T-y., Al Qun, Zhenh, Y-l., Peng, M-s.Study on the micro-infrared spectra and origin of polycrystalline diamonds from Mengyin kimberlite pipes.Spectroscopy and Spectral Analysis, Vol. 32, 8, pp. 1512-1518.ChinaDeposit - Mengyin
DS201312-1008
2013
Yang, Z-J.Zeng, X-Q., Zheng, Y-L., Yang, Z-J., Ai, Hu, Q.Study on the micro-FTIR and raman spectra of the alluvial diamonds from Yangtze craton and their geological significance.Spectroscopy and Spectral Analysis, Vol. 33, no. 10.pp. 2694-2699.ChinaAlluvials
DS201702-0254
2017
Yang, Z-M.Xu, B., Griffin, W.L., Xiong, Q., Hou, Z-Q, O'Reilly, S.Y., Guo, Z., Pearson, N.J., Greau, Y., Yang, Z-M., Zheng, Y-C.Ultrapotassic rocks and xenoliths from South Tibet: contrasting styles of interaction between lithospheric mantle and asthenosphere during continental collision.Geology, Vol. 45, 1, pp. 51-54.China, TibetUPR - metasomatism

Abstract: Widespread Miocene (24-8 Ma) ultrapotassic rocks and their entrained xenoliths provide information on the composition, structure, and thermal state of the sub-continental lithospheric mantle in southern Tibet during the India-Asia continental collision. The ultrapotassic rocks along the Lhasa block delineate two distinct lithospheric domains with different histories of depletion and enrichment. The eastern ultrapotassic rocks (89°E-92°E) reveal a depleted, young, and fertile lithospheric mantle (87Sr/86Srt = 0.704-0.707 [t is eruption time]; Hf depleted-mantle model age [TDM] = 377-653 Ma). The western ultrapotassic rocks (79°E-89°E) and their peridotite xenoliths (81°E) reflect a refractory harzburgitic mantle refertilized by ancient metasomatism (lavas: 87Sr/86Srt = 0.714-0.734; peridotites: 87Sr/86Srt = 0.709-0.716). These data integrated with seismic tomography suggest that upwelling asthenosphere was diverted away from the deep continental root beneath the western Lhasa block, but rose to shallower depths beneath a thinner lithosphere in the eastern part. Heating of the lithospheric mantle by the rising asthenosphere ultimately generated the ultrapotassic rocks with regionally distinct geochemical signatures reflecting the different nature of the lithospheric mantle.
DS1983-0573
1983
YANG DAYUShen zhutong, YANG DAYU, Sun guoxian, CHEN XICHENG.The Microstructure of Synthetic DiamondsKexue Tongbao, Vol. 28, No. 1, PP. 24-29.ChinaMineralogy
DS1985-0749
1985
Yang fengying, FANG QINGSONG.Yan binggang, LIANG RIXUAN, Yang fengying, FANG QINGSONG.Some characters of diamond and diamond bearing ultramafic rocks in Xizang(Tibet).*CHI27th. International Geological Congress Held China**chi, pp. 341-350ChinaUltramafics, Diamond Genesis
DS1989-0907
1989
Yang GuangshuLuo Huiwen, Yang GuangshuThe characteristics of lamproite in Zhenyuan area Guizhou.*CHIYanshi Kuangwuxue Zazhi, (Acta Petrologica et Mineralogica) *CHI, Vol. 8, No. 2, pp. 97-109ChinaLamproite, Geochronology
DS1990-1607
1990
Yang JianjunYang Jianjun, Guo WenxiangStudy of a unique eclogitic inclusion in the kimberlite in Shandong, EastChinaInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 1, extended abstract p. 502-504ChinaEclogite, Inclusions
DS1992-1715
1992
Yang JianjunYang JianjunA new scheme for calculating mineral end members with reference to clinopyroxene and garnetActa Geologica Sinica, Vol. 5, No. 2, June pp. 191-196GlobalMineralogy, Garnet
DS1991-1932
1991
Yang JianminZhou Xiouzhong, Huang Yunhui, Qin Shuying, Gao Yan, Yang JianminTypes, typomorphic characteristics of garnet from kimberlites in Shandong and Liaoning and its relationship with diamond.*CHIYanshi Kuangwuxue Zazhi (Acta Petrologica et Mineralogica)*CHI, Vol. 10, No. 3, August pp. 252-264ChinaPetrology, Garnets from kimberlites
DS1992-1716
1992
Yang RuiyingYang Ruiying, Yuan CaoA preliminary study on the trace element geochemistry of ultramafic inclusions in the eastern part of Lianoning-Jilin ChinaInternational Symposium Cenozoic Volcanic Rocks Deep seated xenoliths China and its, Abstracts pp. 103-104ChinaGeochemistry, Ultramafic
DS1984-0269
1984
Yang Yong FuFan liangming, Yang Yong Fu, Wen LuUltra violet photographs and spectral characteristics of mixed type diamonds in a kimberlite tube inChina. *CHIActa Petrologica Mineralogica Et Analytica *CHI, Vol. 3, No. 4, (12) pp. 339-345ChinaDiamond Morphology
DS1992-1717
1992
Yang YuYang Yu, Morse, S.A.Age and cooling history of the Kiglapait Intrusion from an 40Ar /39ArstudyGeochimica et Cosmochimica Acta, Vol. 56, No. 6, June, pp. 2471-2485Quebec, Labrador, UngavaGeochronology, Layered intrusions
DS1990-1427
1990
Yang ZiyuenSu Weijun, Yang ZiyuenVaotite- a new gemstone from Baiyun Ebo inner MongoliaInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 2, extended abstract p. 688-689ChinaCarbonatite, Mineralogy -vaolite
DS1986-0882
1986
Yang ZunyiYang Zunyi, Cheng Yuqi, Wang HongzhenThe geology of ChinaClarendon Press, Oxford, ChinaBlank
DS1998-1651
1998
YanginZuev, V.M., Bezborodov, S.M., Chyerny, S.D., YanginThe structures which control the location of kimberlites of Middle-Markinsky region.7th International Kimberlite Conference Abstract, pp. 1031-3.Russia, Siberia, YakutiaStructure, tectonics, Deposit - Botuibinskaya, Nyurbinskaya
DS2000-0771
2000
YanginPokhilenko, N.P., Sobolev, N.V., Chernyi, S.D., YanginPyropes and chromites from kimberlites in the Nakyn Field, and Snipe Lake (Slave River region) Evidence...Doklady Academy of Sciences, Vol. 372, No. 4, May-June pp. 638-42.Northwest Territories, Russia, YakutiaLithosphere - structure, Deposit - Nakyn, Snipe Lake
DS1995-2097
1995
Yangin, VV.Yangin, VV.Laws of structural control of localization of kimberlite pipes in the Daldyn field from CDPM data.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 672-674.Russia, YakutiaStructure, Deposit -Daldyn
DS1983-0002
1983
Yangin, YU.T.Afanasev, B.P., Yangin, YU.T.Buried Primary Dispersion Streams of Kimberlite Bodies in The MalobuTo bin Skii Region.Geology And Geophysics, Vol. 24, No. 6, PP. 76-81.Russia, YakutiaGeochemistry, Sampling
DS1995-2098
1995
YangshenYangshen, Shi, Huafu, L., Valin, Z.C.Paleozoic plate tectonic evolution of the Tarim and western Tianshanregions, western China.International Geology Review, Vol. 36, No. 11, Nov. pp. 1058-1066.ChinaTectonics
DS200412-2175
2004
Yangsong, D.Yangsong, D., Hyunkoo, L., Xinlong, Q.Underplating of Mesozoic mantle derived magmas in Tongling, Anhui Province: evidence from megacrysts and xenoliths.Acta Geologica Sinica, Vol. 78, 1, pp. 131-136.China, AnhuiMagmatism
DS200712-0980
2006
Yanhe, L.Shihong, T., Tiping, D., Jingwen, M., Yanhe, L., Zhongxin, Y.S, C, O, H isotope dat a and noble gas studies of the Maoniuping LREE deposit, Sichuan Province, China: a mantle connection for mineralization.Acta Geologica Sinica, Vol. 80, 4, pp. 540-549.ChinaAlkaline rocks, rare earths, carbonatite
DS1970-0673
1973
Yanitskii, I.N.Eremeev, A.N., Sokolov, V.A., Solovov, A.P., Yanitskii, I.N.Application of Helium Surveying to Structural Mapping and Ore Deposit Forecasting.International GEOCHEM. Exploration Symposium 4TH., PP. 183-192.RussiaKimberlite, Geophysics
DS1991-1902
1991
Yannan BaoYannan Bao, Matsyuk, S.S.Composition of kimberlite spinels from Shangtung and Liaoning Provinces inChinaGeochemistry International, Vol. 28, No. 9, pp. 89-95ChinaGeochemistry, kimberlite spinels
DS2002-0014
2002
Yano, M.Akogi, M., Yano, M., Suzuki, T., Koijitani, H.Phase transformation in calcium bearing silicates at high pressures and high temperatures.18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.76.MantleUHP mineralogy - diopside, hedenbergite
DS1996-1361
1996
Yanova, E.O.Staritskii, Yu.G., Kochkin, G.B., Yanova, E.O.Regularities of spatial distribution of the major minerals in the Russian Platform coverGeology of Ore Deposits, Vol. 38, No. 1, pp. 66-77RussiaModels, genesis, Uranium, Rare earths
DS2003-0973
2003
Yanovskaya, T.B.Mordvinova, V.V., Kozhevnikov, V.M., Yanovskaya, T.B., Treussov, A.V.Baikal rift zone: the effect of mantle plumes on older structureTectonophysics, Vol. 371, 1-4, pp. 153-173.Russia, BaikalTectonics, rifting
DS2003-1131
2003
Yanovskaya, T.B.Rasskazov, S.V., Logachev, N.A., Kozhevnikov, V.M., Yanovskaya, T.B.Multistage dynamics of the upper mantle in eastern Asia: relationships betweenDoklady Earth Sciences, Vol. 390, 4, pp. 492-6.Asia, RussiaGeodynamics, Tectonics
DS2003-1525
2003
Yanovskaya, T.B.Yanovskaya, T.B., Kozhevnikov, V.M.3D S wave velocity pattern in the upper mantle beneath the continent of Asia fromPhysics of the Earth and Planetary Interiors, Vol. 138, 3-4, pp. 263-278.ChinaGeophysics - seismics
DS200412-1364
2003
Yanovskaya, T.B.Mordvinova, V.V., Kozhevnikov, V.M., Yanovskaya, T.B., Treussov, A.V.Baikal rift zone: the effect of mantle plumes on older structure.Tectonophysics, Vol. 371, 1-4, pp. 153-173.Russia, BaikalTectonics, rifting
DS200412-1630
2003
Yanovskaya, T.B.Rasskazov, S.V., Logachev, N.A., Kozhevnikov, V.M., Yanovskaya, T.B.Multistage dynamics of the upper mantle in eastern Asia: relationships between wandering volcanism and low velocity anomalies.Doklady Earth Sciences, Vol. 390, 4, pp. 492-6.Asia, RussiaGeodynamics Tectonics
DS200412-2176
2003
Yanovskaya, T.B.Yanovskaya, T.B., Kozhevnikov, V.M.3D S wave velocity pattern in the upper mantle beneath the continent of Asia from rayleigh wave data.Physics of the Earth and Planetary Interiors, Vol. 138, 3-4, pp. 263-278.ChinaGeophysics - seismics
DS201312-0273
2013
Yanovskaya, T.B.Foulger, G.R., Panza, G.F., Artemieva, I.M., Bastow, I.D., Cammarano, F., Evans, J.R., Hamilton, W.B., Julian, B.R., Lustrino, M., Thybo, H., Yanovskaya, T.B.Caveat on tomographic images.Terra Nova, Vol. 25, 4, pp. 259-281.MantleSeismic tomography, geodynamics
DS200912-0063
2009
Yantao, H.Bonadiman, C., Yantao, H., Coltorti, M., Dallai, L., Faccini, B., Huang, YU., Xia, Q.Water content of pyroxenes in intraplate lithospheric mantle.European Journal of Mineralogy, Vol. 21, 3, June pp. 637-647.MantleWater
DS2001-0005
2001
YanyginAfanasev, V.P., Zinchuk, Pkhilenko, Krivonos, YanyginKarst role in the formation of diamond placers of the Muno Markhinskii interfluve Yakutsk diamond provinceGeol. Ore Depos., Vol. 43, No. 3, pp. 234-8.Russia, SiberiaAlluvials, Geomorphology
DS1998-0244
1998
Yanygin, Ju.T.Cherny, S.D., Fomin, A.S., Yanygin, Ju.T., Banzeruk, V.Geology and composition of the Nakyn field kimberlite pipes and diamond properties (Yakutia).7th International Kimberlite Conference Abstract, pp. 147-148.Russia, YakutiaPetrology, Deposit - Botuobinskaya, Nurbinskaya
DS200412-1561
2003
Yanygin, Y.T.Pokhilenko, N.P., Agashev, A.M., McDonald, J.A., Sobolev, N.V., Mityukhin, S.I., Vavilov, M.A., Yanygin, Y.T.Kimberlites of the Nakyn field, Siberia and the Snap Lake King Lake dyke system, Slave Craton, Canada: a new variety of kimberli8 IKC Program, Session 7, POSTER abstractCanada, Northwest TerritoriesKimberlite petrogenesis Deposit - Snap Lake, King Lake
DS1983-0593
1983
Yanygin, YU.T.Taranenko, V.I., Prokopchuk, B.I., Yanygin, YU.T., Shapovalova.Paleogeomorphological Environment of Diamond Placer Genesis at the Southeastern Slope of the Tunguska Syneclise During The Late Paleozoic.Geomorfologiya., 1983 (2), PP. 48-53.RussiaGeomorphology, Alluvial Placers
DS201802-0268
2018
Yao, C.Sun, W-d., Hawkesworth, C.J., Yao, C., Zhang, C-C., Huang, R.f., Liu, X., Sun, X-L, Ireland, T., Song, M-s., Ling, M-x., Ding, X., Zhang, Z-f., Fan, W-m., Wu, Z-q.Carbonated mantle domains at the base of the Earth's transition zone.Chemical Geology, Vol. 478, pp. 69-75.Mantlecarbonatite

Abstract: The oxygen fugacity of the upper mantle is 3-4 orders of magnitude higher than that of the lower mantle and this has been attributed to Fe2 + disproportionating into Fe3 + plus Fe0 at pressures > 24 GPa. The upper mantle might therefore have been expected to have evolved to more oxidizing compositions through geological time, but it appears that the oxygen fugacity of the upper mantle has remained constant for the last 3.5 billion years. Thus, it indicates that the mantle has been actively buffered from the accumulation of Fe3 +, and that this is linked to oxidation of diamond to carbonate coupled with reduction of Fe3 + to Fe2 +. When subducted plates penetrate into the lower mantle, compensational upwelling transports bridgmanite into the transition zone, where it breaks down to ringwoodite and majorite, releasing the ferric iron. The system returns to equilibrium through oxidation of diamond. Early in Earth history, diamond may have been enriched at the base of the transition zone in the Magma Ocean, because it is denser than peridotite melts at depths shallower than 660 km, and it is more buoyant below. Ongoing oxidation of diamond forms carbonate, leading to relatively high carbonate concentrations in the source of ocean island basalts.
DS200812-0022
2008
Yao, D.B.Allialy, M.E., Djro, S.C., Yavouba, C., Konamelan, A.N., Pothin, K.B., Yao, D.B., Yobou, R.Comparative geochemistry of Seguela kimberlites, South Africa Group II kimberlites and other worldwide kimberlites.9IKC.com, 3p. extended abstractAfrica, West Africa, Ivory CoastDeposit - Bobi, Toubabouko
DS201212-0127
2013
Yao, H.Cheng, C., Chen, L., Yao, H., Jiang, M., Wang, B.Distinct variations of crustal shear wave velocity structure and radial anisotropy beneath the North Chin a Craton and tectonic implications.Gondwana Research, Vol. 23, 1, pp. 25-38.ChinaTomography
DS202004-0502
2020
Yao, J.Cawood, P.A., Wang, W., Zhao, T., Xu, Y., Mulder, J.A., Pisarevsky, S.A., Zhang, L., Gan, C., He, H., Liu, H., Qi, L., Wang, Y., Yao, J., Zhao, G., Zhou, M-F., Zi, J-W.Deconstructing south China and consequences for reconstructing Nuna and Rodinia.Earth-Science Reviews, in press available, 70p. PdfChinatectonics

Abstract: Contrasting models for internal and external locations of South China within the Nuna and Rodinia supercontinents can be resolved when the current lithotectonic associations of Mesoproterozoic and older rocks units that constitute the craton are redefined into four lithotectonic domains: Kongling, Kunming-Hainan, Wuyi, and Coastal. The Kongling and Kunming-Hainan domains are characterized by isolated Archean to early Paleoproterozoic rock units and events and crop out in northern and southern South China, respectively. The Kunming-Hainan Domain is preserved in three spatially separated regions at Kunming (southwestern South China), along the Ailaoshan shear zone, and within Hainan Island. Both domains were affected by late Paleoproterozoic tectonothermal events, indicating their likely juxtaposition by this time to form the proto-Yangtze Block. Late Paleoproterozoic and Mesoproterozoic sedimentary and igneous rock units developed on the proto-Yangtze Block, especially in its southern portions, and help link the rock units that formed along the shear zone at Ailaoshan and on Hainan Island into a single, spatially unified unit prior to Paleozoic to Cenozoic structural disaggregation and translation. The Wuyi Domain consists of late Paleoproterozoic rock units within a NE-SW trending, fault-bounded block in eastern South China. The Coastal Domain lies east of the Wuyi domain and is inferred to constitute a structurally separate block. Basement to the domain is not exposed, but zircon Hf model ages from Mesozoic granites suggest Mesoproterozoic basement at depth. The Archean to Paleoproterozoic tectonothermal record of the Kongling and Kunming-Hainan domains corresponds closely with that of NW Laurentia, suggesting all were linked, probably in association with assembly and subsequent partial fragmentation of the Nuna supercontinent. Furthermore, the age and character of Mesoproterozoic magmatism and detrital zircon signature of sedimentary rocks in the proto-Yangtze Block matches well with western Laurentia and eastern Australia-Antarctica. In particular, the detrital zircon signature of late Paleoproterozoic to early Mesoproterozoic sedimentary units in the block (e.g. Dongchuan Group) share a similar age spectrum with the Wernecke Supergroup of northwest Laurentia. This, together with similarities in the type and age of Fe-Cu mineralization in the domain with that in eastern Australia-Antarctica, especially northeast Australia, suggests a location adjacent to northwest Laurentia, southern Siberia, and northeast Australia within the Nuna supercontinent. The timing and character of late Paleoproterozoic magmatic activity in the Wuyi domain along with age of detrital zircons in associated sedimentary rocks matches the record of northern India. During rifting between Australia-Antarctica and Laurentia in the late Mesoproterozoic, the proto-Yangtze Block remained linked to northeast Australia. During accretionary orogenesis in the early Neoproterozoic, the proto-Yangtze Block assembled with the Wuyi Domain along the northern margin of India. The Coastal domain likely accreted at this time forming the South China Craton. Displacement of the Hainan and Ailaoshan assemblages from southwest of the Kunming assemblage likely occurred in the Cenozoic with the activation of the Ailaoshan-Red River fault system but could have begun in the early to mid-Paleozoic based on evidence for tectonothermal events in the Hainan assemblage.
DS201610-1882
2016
Yao, L.Le Roux, V., Nielsen, S.G., Sun, C., Yao, L.Dating layered websterite formation in the lithospheric mantle.Earth and Planetary Science Letters, Vol. 454, pp. 103-112.Mantle, Africa, MoroccoMelting

Abstract: Pyroxenites are often documented among exhumed mantle rocks, and can be found in most tectonic environments, from supra-subduction to sub-continental and sub-oceanic mantle. In particular, websterites, i.e. orthopyroxene-clinopyroxene bearing pyroxenites, are found in parallel layers in most orogenic and ophiolitic peridotites. Their formation is often ascribed to melt infiltration and melt-rock reaction processes accompanied by variable amount of deformation. One outstanding question is whether the ubiquitous occurrence of layered websterites in exhumed rocks is generally linked to the exhumation process or truly represents large-scale melt infiltration processes at depth prior to exhumation. These two hypotheses can be distinguished by comparing the exhumation and formation ages of the websterites. However, determination of the layered websterite formation age is challenging. Here we present a novel approach to constrain the formation age of websterite layers using samples from the Lherz massif (France), where layered websterites and lherzolites have formed through melt-rock reaction. By combining high-resolution REE variations, isotope model ages, and diffusive re-equilibration timescales using REE closure temperatures across the websterite layers, we constrain a minimum age and a maximum age for the formation of layered websterites. We show that layered websterites in Lherz formed 1,500-1,800 Ma ago, and are thus clearly disconnected from the process of exhumation at 104 Ma. Multiple generations of layered websterites commonly found in ultramafic massifs, along with the evidence for ancient melt-rock reaction in Lherz, indicate that melt-rock reactions can happen episodically or continuously in the mantle and that layered websterites found in exhumed mantle rocks record ubiquitous melt infiltration processes in the mantle.
DS200512-0659
2005
Yao, N.Lu, P.J., Yao, N., So, J.F., Harlow, G.E., Lu, J.F., Wang, G.F., Chaikin, P.M.The earliest use of corundum and diamond in prehistoric China.Archeometry, Vol. 47,1, Feb. pp. 1-12. Blackwell PublicationsChinaHistory
DS200812-1247
2008
Yao, P.Wen, B., Zhao, J., Bucknum, M.J., Yao, P., Li, T.First principles studies of diamond polytypes.Diamond and Related Materials, Vol. 17, 3, pp. 356-364.TechnologyDiamond crystallography - simulation
DS1998-1611
1998
Yao, S.Yao, S., Griffin, W.L., O'Reilly, S.Y.Trace elements in chromites from kimberlites and related rocks: relation to temperature and mantle comp.7th International Kimberlite Conference Abstract, pp. 980-82.MantlePetrogenetic indicator, genesis, Mantle Array chromites
DS201904-0763
2019
Yao, W.Olierook, H.K.H., Agangi, A., Plavsa, D., Reddy, S.M., Yao, W., Clark, C., Occipinti, S.A., Kylander-Clark, A.R.C.Neoproterozoic hydrothermal activity in the west Australian craton related to Rodinia assembly or breakup?Gondwana Research, Vol 68, 1, pp. 1-12.Australiacraton

Abstract: The timing of final assembly and initiation of subsequent rifting of Rodinia is disputed. New rutile ages (913?±?9?Ma, 900?±?8?Ma and 873?±?3?Ma) and published zircon, monazite, titanite, biotite, muscovite and xenotime geochronology from the Capricorn Orogen (West Australian Craton) reveal a significant early Neoproterozoic event characterized by very low to low metamorphic grade, abundant metasomatism, minor leucogranitic and pegmatitic magmatism and NW-SE fault reactivation episodes between ca. 955 and 830?Ma. Collectively, these are termed the ca. 955-830?Ma Kuparr Tectonic Event. An age range of ca. 955-830?Ma is concomitant with the final stages of Rodinia assembly and the initial stages of its attempted breakup. Very low- to low-grade metamorphic and structural geological evidence favor a distal north-south compressional regime as the driver for hydrothermal activity during ca. 955-830?Ma. Nearby continental collision or accretion from the west (e.g., South China and/or Tarim) are ruled out. The cessation of metasomatism and magmatism in the West Australian Craton after ca. 830?Ma is concomitant with the emplacement of the Gairdner-Amata dyke swarm and associated magmatic activity in South China and Laurentia, the inception of the Adelaide Rift Complex and the deposition of the Centralian Superbasin. We posit that the cessation of hydrothermal activity in the Capricorn Orogen was caused by a tectonic switch from compressional to extensional at ca. 830?Ma. Magmatic and hydrothermal fluids were transferred away from the Capricorn Orogen to the incipient Adelaide Rift Complex, terminating metasomatism in the West Australian Craton. Ultimately, the Kuparr Tectonic Event marked the final stages of Rodinia assembly and its cessation marks the initial stages of its attempted breakup.
DS201112-1136
2011
Yao, Z.Ye, L., Li, J., Tseng, T-L., Yao, Z.A stagnant slab in a water bearing transition zone beneath northeast China: implications from regional SH waveform modelling.Geophysical Journal International, Vol. 186, 2, pp. 706-710.ChinaSubduction
DS201112-1137
2011
Yao, Z.Ye, L., Tseng, T-L., Yao, Z.A stagnant slab in a water bearing mantle transition zone beneath northeast China: implications from regional SH waveform modelling.Geophysical Journal International, In press available,ChinaSubduction
DS201811-2621
2018
Yao, Z.Yang, H., Xiao, J., Yao, Z., Zhang, X., Younus, F., Melnik, R., Wen, B.Homogeneous and heterogenous dislocation nucleation in diamond.Diamond & Related Materials, Vol. 88, pp. 110-117.Mantlediamond morphology

Abstract: Dislocation nucleation plays a key role in plastic deformation of diamond crystal. In this paper, homogeneous and heterogeneous nucleation nature for diamond glide set dislocation and shuffle set dislocation is studied by combining molecular dynamics method and continuum mechanics models. Our results show that although heterogeneous dislocation nucleation can decrease its activation energy, the activation energy at 0?GPa for diamond heterogeneous nucleation is still in the range of 100?eV. For glide set and shuffle set homogeneous nucleation, their critical nucleation shear stress approaches to diamond's ideal shear strength which implies that those dislocations do not nucleate before diamond structural instability only by a purely shearing manner. While for glide set and shuffle set heterogeneous nucleation, their critical nucleation shear stresses are 28.9?GPa and 48.2?GPa, these values are less than diamond's ideal shear strength which implies that these dislocations may be nucleated heterogeneously under certain shear stress condition. In addition, our results also indicate there exists a deformation mode transformation for diamond deformation behavior at strain rate of 10-3/s. Our results provide a new insight into diamond dislocation nucleation and deformation.
DS1992-0318
1992
Yao ShaodeCui Guozhi, Yao ShaodeTentative study on the principle of radio resonant seperation of Kimberlite and its wall rockInternational Journal of Mineral Processing, Vol. 34, No. 1-2, January pp. 177-183ChinaMineral processing, Kimberlite
DS1991-1903
1991
Yaoling NiuYaoling Niu, Batiza, R.DENSCAL: a program for calculating densities of silicate melts and Mantle minerals as a function of pressure, temperature, and composition in meltingrangeComputers and Geosciences, Vol. 17, No. 5, pp. 679-688GlobalComputer, Program -DENSCAL -silicates
DS1991-1904
1991
Yaoling NiuYaoling Niu, Batiza, R.In situ densities of Mid Ocean Ridge Basalt (MORB) melts and residual mantle: implications for bouyancy forces beneath mid-Ocean ridgesJournal of Geology, Vol. 99, pp. 767-775GlobalMantle, Mid Ocean Ridge Basalt (MORB), tectonics
DS201511-1886
2015
Yap, C.M.Tarum, A., Lee, S.J., Yap, C.M., Finkelstein, K.D., Misra, D.S.Impact of impurities and crystal defects on the performance of CVD diamond detectors.Diamond and Related Materials, in press available, 6p.TechnologySynthetics - Radiation detectors

Abstract: Radiation detectors based on diamond are highly favored for particle physics research due to the superior radiation hardness. In this work, we investigate the influence of impurities and crystalline imperfections on the charge collection efficiency (CCE) of single crystal diamond. Seventeen (17) ultra-low fluorescent diamond samples grown by microwave plasma chemical vapor deposition method from IIa Technologies PTE LTD are pre-selected for this study. The measured CCE of all samples using 241Am (a-particles) as ionizing source are analyzed together with the concentration of trace impurities and crystalline imperfection in the crystal. The amounts of impurities are quantified from integrated fluorescence intensity arising from the nitrogen vacancies (NV) created during different CVD growth process conditions. The crystal imperfections are assessed by X-ray rocking curves from X-ray topography images obtained at the Cornell High Energy Synchrotron Source. The CCE decays rapidly as the intensity of NV (INV), phonon sideband approaches that of diamond 2nd order Raman peak which follows the relation: View the MathML sourceCCEINV=100/1+INV1.052. The energy resolution, ?E/E (ratio of the energy spectrum width to the most probable peak) highly correlates with broader rocking curve width distribution. Prime novelty statement: This work provides an understanding on the most important factors that contribute to degradation of charge collection efficiency (CCE) in diamond based detectors and sensors. The CCE decays rapidly as the intensity of nitrogen vacancy phonon sideband approaches that of diamond 2nd order Raman peak which follows the relation: View the MathML sourceCCEINV=100/1+INV1.052. The energy resolution, that is the ratio of the energy spectrum width to the most probable peak, highly correlates with broader X-ray rocking curve width distribution.
DS201511-1889
2015
Yap, C.M.Yap, C.M., Tarum, A., Xiao, S., Misra, D.S.MPCVD growth of 13 C-enriched diamond single crystals with nitrogen addition.Diamond and Related Materials, in press available, 29p.TechnologySynthetics - nitrogen

Abstract: This study describes the growth of 13C-enriched (100)-oriented diamond single crystals by the MPCVD (microwave plasma chemical vapour deposition) process. All crystals are at least 6 × 6 mm2 in area and 0.5-1.0 mm in thickness. The samples with nominal 13C percentages (R = [13C] / [13C + 12C]) of 0.011 (natural abundance), 0.10, 0.21, 0.24 and 0.34 were obtained by controlling the flow of the carbon-13 and carbon-12 methane feed gases. To obtain thicker and near-colourless quality 13C-enriched diamond, 190 ppm of nitrogen was added into the gas mixture. The shift towards lower frequency in the Raman peak positions and decrease in the thermal conductivities of the near-colourless crystals with increasing 13C percentages are similar to previous studies of isotopically-controlled diamond grown with no nitrogen additive. The images of the structural defects associated with 13C-enrichment obtained by spatially-resolved X-ray rocking curve measurement show distinct patterned structures that runs parallel to the < 100 > direction. Moreover, the broadening in the line width of the nuclear magnetic resonance (NMR) peak from sp313C correlates with increasing R. We also expand the study by injecting 500 ppm of nitrogen. Higher nitrogen concentration leads to the formation of brown crystals. The brown crystals show far greater 13C NMR peak intensity than the near-colourless. This suggests that paramagnetic nitrogen impurities in the brown crystals hasten the spin-lattice relaxation time of the 13C nuclear spin that resulted in higher intensity. The isotopic splitting observed for the localized vibrational mode of the NVH0 defect in brown crystals is attributed to the co-existence of both the 13C (3114.2 cm- 1) and 12C (3123.5 cm- 1). Unlike the isotopic splitting observed for NVH0 defect, the peak position of the Ns+ defect shifts towards lower frequency as R increases. Not only have we demonstrate the growth of bigger isotopically-controlled diamond single crystals, the results shown here have provided a framework to further investigate the interplay between 13C atoms and nitrogen impurity.
DS2002-1243
2002
YapaskurtPerchuk, L.L., Safonov, O.G., Yapaskurt, BartonCrystal melt equilibration temperatures involving potassium bearing clinopyroxene as indicator of mantle derived ultrahighLithos, Vol.60, pp. 89-111.MantleMelting - potassic liquids, an analytical review
DS1995-1479
1995
Yapaskurt, V.O.Perchuk, L.L., Yapaskurt, V.O., Okay, A.Comparative petrology of diamond bearing complexesPetrology, Vol. 3, No. 3, May-June pp. 238-277.RussiaPetrology, Diamond complexes
DS2002-1244
2002
Yapaskurt, V.O.Perchuk, L.L., Safonov, O.G., Yapaskurt, V.O., BartonCrystal melt equilibration temperatures involving potassium bearing clinopyroxene as indicator of mantle derived ultrahighLithos, Vol. 60, No. 3-4, Feb. pp. 89-111.MantleAnalytical review - potassic liquids
DS2003-0111
2003
Yapaskurt, V.O.Bindi, L., Safonov, O.G., Yapaskurt, V.O., Perchuk, L.L., Menchetti, S.Ultrapotassic clinopyroxene from the Kumdy Kol microdiamond mine, KokchetavAmerican Mineralogist, Vol. 88, 2-3, Feb.March pp. 464-8.Russia, KazakhstanMineral chemistry, Kokchetav Complex
DS200812-0882
2008
Yapaskurt, V.O.Perchuk, A.L., Yapaskurt, V.O., Davydova, V.V.Melt inclusions in eclogite garnet: experimental study of natural processes.Russian Geology and Geophysics, Vol. 49, 4, pp. 310-312.Canada, YukonEclogite - melting
DS200912-0658
2009
Yapaskurt, V.O.Safonov, O.G., Perchuk, L.L., Yapaskurt, V.O., Litvin, Yu.A.Immiscibility of carbonate silicate and chloride carbonate melts in the kimberlite CaCO3 Na2Co3 KCL system at 4.8 GPa.Doklady Earth Sciences, Vol. 424, 1, pp. 142-146.TechnologyGeochemistry
DS201012-0573
2009
Yapaskurt, V.O.Perchuk, A.L., Davydova, V.V., Burchard, M., Maresch, W.V., Schertl, H.P., Yapaskurt, V.O., Safonov, O.G.Modification of mineral inclusions in garnet under high pressure conditions: experimental simulation and application to carbonate silicate rocks of KokchetetavRussian Geology and Geophysics, Vol. 50, 12, pp. 1153-1168.RussiaMineralogy
DS201412-0672
2013
Yapaskurt, V.O.Perchuk, A.L., Shur, M.Yu., Yapaskurt, V.O., Podgornova, S.T.Experimental modeling of mantle metasomatism coupled with eclogitization of crustal material in a subduction zone.Petrology, Vol. 21, 6, pp. 579-598.MantleSubduction
DS201505-0249
2015
Yapaskurt, V.O.Belogub, E.V., Krivovichev, S.V., Pekov, I.V., Kuznetsov, A.M., Yapaskurt, V.O., Kitlyarov, V.A., Chukanov, N.V., Belakoviskiy, D.I.Nickelpicromerite, K2Ni(SO4)2*6H2O, a new picromerite group mineral from Slyudorudnik, South Urals, Russia.Mineralogy and Petrology, Vol. 109, 2, pp. 143-152.Russia, UralsMineralogy

Abstract: A new picromerite-group mineral, nickelpicromerite, K2Ni(SO4)2 - 6H2O (IMA 2012-053), was found at the Vein #169 of the Ufaley quartz deposit, near the town of Slyudorudnik, Kyshtym District, Chelyabinsk area, South Urals, Russia. It is a supergene mineral that occurs, with gypsum and goethite, in the fractures of slightly weathered actinolite-talc schist containing partially vermiculitized biotite and partially altered sulfides: pyrrhotite, pentlandite, millerite, pyrite and marcasite. Nickelpicromerite forms equant to short prismatic or tabular crystals up to 0.07 mm in size and anhedral grains up to 0.5 mm across, their clusters or crusts up to 1 mm. Nickelpicromerite is light greenish blue. Lustre is vitreous. Mohs hardness is 2-2½. Cleavage is distinct, parallel to {10-2}. Dmeas is 2.20(2), Dcalc is 2.22 g cm-3. Nickelpicromerite is optically biaxial (+), a = 1.486(2), ß = 1.489(2), ? = 1.494(2), 2Vmeas =75(10)°, 2Vcalc =76°. The chemical composition (wt.%, electron-microprobe data) is: K2O 20.93, MgO 0.38, FeO 0.07, NiO 16.76, SO3 37.20, H2O (calc.) 24.66, total 100.00. The empirical formula, calculated based on 14 O, is: K1.93Mg0.04Ni0.98S2.02O8.05(H2O)5.95. Nickelpicromerite is monoclinic, P21/c, a = 6.1310(7), b = 12.1863(14), c = 9.0076(10) Å, ß = 105.045(2)°, V = 649.9(1) Å3, Z = 2. Eight strongest reflections of the powder XRD pattern are [d,Å-I(hkl)]: 5.386--34(110); 4.312-46(002); 4.240-33(120); 4.085--100(012, 10-2); 3.685-85(031), 3.041-45(040, 112), 2.808-31(013, 20-2, 122), 2.368-34(13-3, 21-3, 033). Nickelpicromerite (single-crystal X-ray data, R = 0.028) is isostructural to other picromerite-group minerals and synthetic Tutton’s salts. Its crystal structure consists of [Ni(H2O)6]2+ octahedra linked to (SO4)2- tetrahedra via hydrogen bonds. K+ cations are coordinated by eight anions. Nickelpicromerite is the product of alteration of primary sulfide minerals and the reaction of the acid Ni-sulfate solutions with biotite.
DS201609-1729
2016
Yapaskurt, V.O.Lykova, I.S., Pekov, I.V., Chukanov, N.V., Belakovskiy, D.I., Yapaskurt, V.O., Zubkova, N.V., Britvin, S.N., Giester, G.Calciomurmanite a new mineral from the Lovozero and Khibiny alkaline complexes, Kola Peninsula.European Journal of Minerlogy, in press avaialbe 15p.RussiaMineralogy
DS201812-2861
2018
Yapaskurt, V.O.Perchuk, A.L., Yapaskurt, V.O., Zinovieva, N.G., Shur, M. Yu.Experimental evidence for opposite fluxes of sodium, potassium, and CO2 during glaucophane schist interaction with harzburgite and websterite in subduction zones.Petrology, Vol. 26, 6, pp. 599-616.Mantlemetasomatism

Abstract: This paper reports the results of high-pressure experimental modeling of interaction between glaucophane schist and harzburgite or websterite for the evaluation of the influence of mantle material on the input-output of components and character of metasomatic transformations at the crust-mantle boundary in the subduction zone. In all experiments, glaucophane schist (proxy for oceanic crust) containing volatile components (H2O and CO2) incorporated in hydrous minerals (amphiboles, phengite, and epidote) and calcite was loaded into the bottom of each capsule and overlain by mantle material. During the experiments at a temperature of 800°C and a pressure of 2.9 GPa, which correspond to the conditions of a hot subduction zone, the schist underwent partial (up to 10%) eclogitization with the formation of the anhydrous assemblage omphacite + garnet + quartz ± magnesite ± potassic phase. Carbonate and a potassic phase were formed only in the experiments with websterite in the upper layer. A reaction zone was formed at the base of the websterite layer, where newly formed omphacite, quartz, and orthopyroxene replaced in part initial pyroxenes. Orthopyroxene and phlogopite (or an unidentified potassic phase) were formed in the reaction zone at the base of the harzburgite layer; among the initial minerals, only orthopyroxene relicts were preserved. Above the reaction zones produced by diffusion metasomatism, new phases developed locally, mainly at grain boundaries: newly formed orthopyroxene and magnesite were observed in harzburgite, and omphacite and quartz, in websterite. Alterations along grain boundaries extended much further than the reaction zones, which indicates that fluid infiltration dominated over diffusion in the experiments. The experiments demonstrated that the H2O-CO2 fluid with dissolved major components released from the glaucophane schist can produce mineral assemblages of different chemical compositions in mantle materials: Na-bearing in websterite and K-bearing in harzburgite. The complementary components, K2O and CO2 for the websterite layer and Na2O for the harzburgite layer, are fixed in the initial glaucophane schist layer. The distinguished separation of alkalis and CO2 at the crust-mantle boundary can affect the character of metasomatism in the mantle wedge, primary magma compositions, and the chemical evolution of the rocks of the subducting slab.
DS201904-0766
2018
Yapaskurt, V.O.Pekov, I.V., Zubkova, N.V., Yapaskurt, V.O., Lykova, I.S., Chukanov, N.V., Belakovskiy, D.I., Britvin, S.N., Turchkova, A.G., Pushcharovsky, D.Y.Alexhomyakovite, K6(Ca2Na) (CO3)5CI.6h2O, a new mineral from the Khibiny alkaline complex, Kola Peninsula, Russia.European Journal of Mineralogy, Vol. 31, pp. 13-143.Russia, Kola Peninsuladeposit - Khibiny

Abstract: The new mineral alexkhomyakovite K6(Ca2Na)(CO3)5Cl·6H2O (IMA2015-013) occurs in a peralkaline pegmatite at Mt. Koashva, Khibiny alkaline complex, Kola peninsula, Russia. It is a hydrothermal mineral associated with villiaumite, natrite, potassic feldspar, pectolite, sodalite, biotite, lamprophyllite, titanite, fluorapatite, wadeite, burbankite, rasvumite, djerfisherite, molybdenite and an incompletely characterized Na-Ca silicate. Alexkhomyakovite occurs as equant grains up to 0.2 mm, veinlets up to 3 cm long and up to 1 mm thick and fine-grained aggregates replacing delhayelite. Alexkhomyakovite is transparent to translucent, colourless, white or grey, with vitreous to greasy lustre. It is brittle, the Mohs hardness is ca. 3. No cleavage was observed, the fracture is uneven. D meas = 2.25(1), D calc = 2.196 g cm-3. Alexkhomyakovite is optically uniaxial (-), ? = 1.543(2), e = 1.476(2). The infrared spectrum is reported. The chemical composition [wt%, electron microprobe data, CO2 and H2O contents calculated for 5 (CO3) and 6 (H2O) per formula unit (pfu), respectively] is: Na2O 4.09, K2O 35.72, CaO 14.92, MnO 0.01, FeO 0.02, SO3 0.11, Cl 4.32, CO2 28.28, H2O 13.90, -O=Cl -0.98, total 100.39. The empirical formula calculated on the basis of 9 metal cations pfu is K5.90Ca2.07Na1.03(CO3)5(SO4)0.01O0.05Cl0.95·6H2O. The numbers of CO3 groups and H2O molecules are based on structure data. Alexkhomyakovite is hexagonal, P63/mcm, a = 9.2691(2), c = 15.8419(4) Å, V = 1178.72(5) Å3 and Z = 2. The strongest reflections of the powder X-ray diffraction pattern [d Å(I)(hkl)] are: 7.96(27)(002), 3.486(35)(113), 3.011(100)(114), 2.977(32)(211), 2.676(36)(300), 2.626(42)(213, 115), 2.206(26)(311) and 1.982(17)(008). The crystal structure (solved from single-crystal X-ray diffraction data, R = 0.0578) is unique. It is based on (001) heteropolyhedral layers of pentagonal bipyramids (Ca,Na)O5(H2O)2 interconnected via carbonate groups of two types, edge-sharing ones and vertex-sharing ones. Ca and Na are disordered. Ten-fold coordinated K cations centre KO6Cl(H2O)3 polyhedra on either side of the heteropolyhedral layer. A third type of carbonate group and Cl occupy the interlayer. The mineral is named in honour of the outstanding Russian mineralogist Alexander Petrovich Khomyakov (1933-2012).
DS1992-0398
1992
Yarborogh, W.A.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
DS1989-1013
1989
Yarbrough, W.Messier, R., Yarbrough, W.SDI is diamond researchs best friendPhysics Today, Vol. 42, No. 9, September p. 146GlobalNews item, SDI
DS1990-1608
1990
Yarbrough, W.A.Yarbrough, W.A., Messier, R.Current issues and problems in the chemical vapor deposition of diamondScience, Vol. 247, pp. 688-696GlobalDiamond synthesis, Review
DS1998-1612
1998
Yardimicilar, C.Yardimicilar, C., Reeves, C.V.Evidence from aeromagnetic anomalies for the pre-drift fit of Madagascar against East Africa.Journal of African Earth Sciences, Vol. 27, 1A, p. 215. AbstractMadagascarGeophysics - aeromagnetics, Tectonics - Gondwana
DS1991-1905
1991
Yardley, B.Yardley, B., Bottrell, S.H., Cliff, R.A.Evidence for regional scale fluid loss event during mid crustalmetamorphismNature, Vol. 349, Jan. 10, pp. 151-4.Mantlemetamorphism
DS1996-0679
1996
Yardley, B.Jamtveit, B., Yardley, B.Fluid flow and transport in rocks: mechanisms and effectsChapman and Hall, ITP Distributors, approx. 150.00GlobalBook -ad, Sedimentary basins, fluid flow
DS1998-1430
1998
Yardley, B.Svensen, H., Jamtveit, B., Yardley, B., Austrheim, H.Eclogite facies fluids from the Caledonides of western Norway: compositions and implications for fluid-rock...Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1481-2.NorwayEclogites, Fluid geochemistry
DS201909-2028
2019
Yardley, B.Cangelosi, D., Broom-Fendley, S., Banks, D., Morgan, D., Yardley, B.LREE redistribution during hydrothermal alteration at the Okorusu carbonatite complex, Namibia.Mineralogical Magazine, in press available 54p. PdfAfrica, Namibiacarbonatite - Okorusu

Abstract: The Cretaceous Okorusu carbonatite, Namibia, includes diopside-bearing and pegmatitic calcite carbonatites, both exhibiting hydrothermally altered mineral assemblages. In unaltered carbonatite, REE, Sr and Ba are largely hosted by calcite and fluorapatite. However, in hydrothermally altered carbonatites, small (< 50 µm) parisite-(Ce) grains are the dominant REE host, while Ba and Sr are hosted in baryte, celestine, strontianite and witherite. Hydrothermal calcite has a much lower trace element content than the original, magmatic calcite. Despite the low REE contents of the hydrothermal calcite, the REE patterns are similar to those of parisite-(Ce), and magmatic minerals and mafic rocks associated with the carbonatites. These similarities suggest that hydrothermal alteration remobilised REE from magmatic minerals, predominantly calcite, without significant fractionation or addition from an external source. Ba and Sr released during alteration were mainly reprecipitated as sulfates. The breakdown of magmatic pyrite into Fe-hydroxide is inferred to be the main source of sulfate. The behaviour of sulfur suggests that the hydrothermal fluid was somewhat oxidising and it may have been part of a geothermal circulation system. Late hydrothermal massive fluorite replaced the calcite carbonatites at Okorusu and resulted in extensive chemical change, suggesting continued magmatic contributions to the fluid system.
DS1991-1906
1991
Yardley, B.W.D.Yardley, B.W.D.Quick shifts in plate motionNature, Vol. 254, No. 6351, November 28, pp. 269-270GlobalGeochronology, Tectonics
DS1994-1961
1994
Yardley, B.W.D.Yardley, B.W.D., Valley, J.W.How wet is the earth's crust?Nature, Vol. 371, Sept. 15, pp. 205-206MantleFluids, Basins
DS1995-2099
1995
Yardley, B.W.D.Yardley, B.W.D., Lloyd, G.E.Why metasomatic fronts are really metasomatic sidesGeology, Vol. 23, No. 1, Jan. pp. 53-56GlobalMetasomatism, Calc-silicate reaction zones
DS1998-1613
1998
Yardley, B.W.D.Yardley, B.W.D., Gleeson, S.A.Dry deep stable crust and its rheology: evidence from deep penetratingfluid.Geological Society of America (GSA) Annual Meeting, abstract. only, p.A393.NorwayRheology, Tectonics
DS200912-0837
2009
Yardley, B.W.D.Yardley, B.W.D.The role of water in the evolution of the continental crust.Journal of the Geological Society, Vol. 166, 4, pp. 585-600.MantleRheology
DS201412-1004
2014
Yardley, B.W.D.Yardley, B.W.D., Bodnar, R.J.Fluids in the continental crustGeochemic