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SDLRC - Scientific Articles all years by Author - Bl-Bq


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 - Bl-Bq
Posted/
Published
AuthorTitleSourceRegionKeywords
DS1975-0947
1979
Blaauw, C.Blaauw, C., White, C.G., Leiper, W., Clarke, D.B.Mossbauer Analysis of Synthetic DjerfisheriteMineralogical Magazine., Vol. 43, No. 328, PP. 552-553.GlobalRelated Mineralogy, Techniques
DS1984-0492
1984
Blacic, J.D.Mathez, E.A., Blacic, J.D., Beery, J., Maggiore, C., Hollander.Carbon Abundances in Mantle Minerals Determined by Nuclear Reaction Analysis.Geophysical Research. LETTERS, Vol. 11, No. 10, OCTOBER, PP. 947-950.United States, Colorado Plateau, New MexicoXenolith, Crystallography
DS1986-0533
1986
Blacic, J.D.Mathez, E.A., Blacic, J.D., Beery, J., Maggiore, C., Hollander, M.Carbon in olivine by nuclear reaction analysisProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 273-275GlobalBlank
DS1987-0444
1987
Blacic, J.D.Mathez, E.A., Blacic, J.D., Beery, J., Hollander, M., Maggiore, C.Carbon in olivine: results from nuclear reaction analysisJournal of Geophys., Res, Vol. 92, No. B5, April 10, pp. 3500-3506GlobalMantle genesis
DS1991-0125
1991
Blacic, J.D.Blacic, J.D., Mathez, E.A., Maggiore, C., Mitchell, T.E., Fogel, R.Oxygen in diamond by the nuclear microprobe: analytical technique and initial resultsProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 20-22GlobalMicroprobe, Oxygen analyses
DS1993-0980
1993
Blacic, J.D.Mathez, E.A., Blacic, J.D., Maggiore, C., Mitchell, T.E., Fogel, R.A.The determination of the O content of diamond by microactivationAmerican Mineralogist, Vol. 78, No. 7-8, July-August pp. 753-761.South Africa, Botswana, ZaireKimberlites, Deposit -Monastery, Finsch, Orapa, Muji Mayi
DS2001-0712
2001
BlackMacdonald, R., Rogers, N., Fitton, J.G., Black, SmithPlume lithosphere interactions in the generation of the basalts of the Kenya rift, east Africa.Journal of Petrology, Vol. 42, No. 5, pp. 877-900.East Africa, KenyaTectonics - plume, mantle
DS202004-0512
2020
Black, B.Gales, E., Black, B., Elkins-Tanton, E.Carbonatites as a record of the carbon isotope composition of large igneous province outgassing.Earth and Planetary Science Letters, Vol. 535, 116076 11p. PdfRussia, Siberiacarbonatite

Abstract: Large igneous province (LIP) eruptions have been linked in some cases to major perturbations of Earth's carbon cycle. However, few observations directly constrain the isotopic composition of carbon released by LIP magmas because carbon isotopes fractionate during degassing, which hampers understanding of the relative roles of mantle versus crustal carbon reservoirs. Carbonatite magmatism associated with LIPs provides a unique window into the isotopic systematics of LIP carbon because the majority of carbon in carbonatites crystalizes rather than degassing. Although the volume of such carbonatites is small, they offer one of the few available constraints on the mantle carbon originally hosted in other more voluminous magma types. Here, we present new data for the Guli carbonatites in the Siberian Traps. In addition, we compile ?260 published measurements of from carbonatites related to the Deccan Traps and the Paraná-Etendeka. We find no evidence for magmas with carbon isotope ratios lighter than depleted mantle values of ‰ from any of these LIPs, though some carbonatites range to heavier . We attribute relatively heavy in some carbonatites to either slightly 13C-enriched domains in the mantle lithosphere or carbon isotope fractionation in deep, carbon-saturated LIP magma reservoirs. The absence of a light component in LIP magmas supports the view that lithospheric carbon reservoirs must be tapped during cases of LIP magmatism linked with sharp negative carbon isotope excursions and mass extinctions.
DS201911-2512
2019
Black, B.A.Black, B.A., Gibson, S.A.Deep carbon and the life cycle of large igneous provinces.Elements, Vol. 15, pp. 319-324.Mantlecarbon

Abstract: Carbon is central to the formation and environmental impact of large igneous provinces (LIPs). These vast magmatic events occur over geologically short timescales and include voluminous flood basalts, along with silicic and low-volume alkaline magmas. Surface outgassing of CO2 from flood basalts may average up to 3,000 Mt per year during LIP emplacement and is subsidized by fractionating magmas deep in the crust. The large quantities of carbon mobilized in LIPs may be sourced from the convecting mantle, lithospheric mantle and crust. The relative significance of each potential carbon source is poorly known and probably varies between LIPs. Because LIPs draw on mantle reservoirs typically untapped during plate boundary magmatism, they are integral to Earth’s long-term carbon cycle.
DS1984-0382
1984
Black, C.P.Jaques, A.L., Webb, A.W., Fanning, C.M., Black, C.P., Pidgeon, R.The Age of the Diamond Bearing Pipes and Associated LeuciteB.m.r. Journal of Aust. Geol. Geophys., Vol. 9, PP.Australia, Western AustraliaGeochronology, Related Rocks
DS1989-0123
1989
Black, D.F.Black, D.F.Tectonic evolution in central and eastern Kentucky:a multidisciplinary study of surface and subsurfacestructureUnited States Geological Survey (USGS) Open File, No. 89-0106, 151p. 12 maps, paper copy $ 86.00USKentuckyTectonics, Structure
DS1975-0741
1978
Black, L.P.Ferguson, J., Black, L.P.Tectonic Setting of Kimberlites in Southeast AustraliaB.m.r. Symposium, No. 7, PP. 28-29, (abstract.).Australia, New South Wales, VictoriaKimberlite
DS1975-0790
1978
Black, L.P.Langworthy, A.P., Black, L.P.The Mordor Complex: a Highly Differentiated Potassic Intrusion with Kimberlitic Affinities in Central Australia.Contributions to Mineralogy and Petrology, Vol. 67, PP. 51-62.AustraliaKimberlite, Carbonatite
DS1975-1235
1979
Black, L.P.Stracke, K.J., Ferguson, J., Black, L.P.Structural Setting of Kimberlites in Southeastern AustraliaProceedings of Second International Kimberlite Conference, Vol. 1, PP. 71-91.Australia, New South Wales, VictoriaKimberlite, Geophysics, Lineaments, Nepheline Basanites
DS1989-1106
1989
Black, L.P.Nelson, D.R., Black, L.P., McCulloch, M.T.Neodymium-Palladium isotopic characteristics of the Mordor Complex, Northern Territory: Mid-Proterozoic potassic magmatism from an enriched mantle sourceAustralian Journal of Earth Sciences, Vol. 36, No. 4, December pp. 541-551AustraliaPotassic rocks, Proterozoic, Mordor Complex, Rare Earth Elements
DS1990-1345
1990
Black, L.P.Sheraton, J.W., Black, L.P., McCulloch, M.T., Oliver, R.L.Age and origin of a compositionally varied mafic dyke swarm in the Bunger Hills ,East AntarcticaChemical Geology, Vol. 85, No. 3/4, July 30, pp. 215-246AntarcticaMafic dyke, Picrite
DS1992-1384
1992
Black, L.P.Sheraton, J.W., Black, L.P., Tindle, A.G.Petrogenesis of plutonic rocks in a Proterozoic granulite-facies terrane-the Bunger Hills, East AntarcticaChemical Geology, Vol. 97, No. 3-4, June 25, pp. 163-198AntarcticaBunger Hills
DS201605-0880
2016
Black, M.Neave, D.A., Black, M., Riley, T.R., Gibson, S.A., Ferrier, G., Wall, F., Broom-Fendley, S.On the feasibility of imaging carbonatite-hosted rare earth element deposits using remote sensing.Economic Geology, Vol. 111, pp. 641-665.China, United States, Europe, GreenlandDeposit - Bayan Obo, Mountain Pass, Motzfeldt, Ilimaussaq

Abstract: Rare earth elements (REEs) generate characteristic absorption features in visible to shortwave infrared (VNIR-SWIR) reflectance spectra. Neodymium (Nd) has among the most prominent absorption features of the REEs and thus represents a key pathfinder element for the REEs as a whole. Given that the world’s largest REE deposits are associated with carbonatites, we present spectral, petrographic, and geochemical data from a predominantly carbonatitic suite of rocks that we use to assess the feasibility of imaging REE deposits using remote sensing. Samples were selected to cover a wide range of extents and styles of REE mineralization, and encompass calcio-, ferro- and magnesio-carbonatites. REE ores from the Bayan Obo (China) and Mountain Pass (United States) mines, as well as REE-rich alkaline rocks from the Motzfeldt and Ilímaussaq intrusions in Greenland, were also included in the sample suite. The depth and area of Nd absorption features in spectra collected under laboratory conditions correlate positively with the Nd content of whole-rock samples. The wavelength of Nd absorption features is predominantly independent of sample lithology and mineralogy. Correlations are most reliable for the two absorption features centered at ~744 and ~802 nm that can be observed in samples containing as little as ~1,000 ppm Nd. By convolving laboratory spectra to the spectral response functions of a variety of remote sensing instruments we demonstrate that hyperspectral instruments with capabilities equivalent to the operational Airborne Visible-Infrared Imaging Spectrometer (AVIRIS) and planned Environmental Mapping and Analysis Program (EnMAP) systems have the spectral resolutions necessary to detect Nd absorption features, especially in high-grade samples with economically relevant REE accumulations (Nd > 30,000 ppm). Adding synthetic noise to convolved spectra indicates that correlations between Nd absorption area and whole-rock Nd content only remain robust when spectra have signal-to-noise ratios in excess of ~250:1. Although atmospheric interferences are modest across the wavelength intervals relevant for Nd detection, most REE-rich outcrops are too small to be detectable using satellite-based platforms with >30-m spatial resolutions. However, our results indicate that Nd absorption features should be identifiable in high-quality, airborne, hyperspectral datasets collected at meter-scale spatial resolutions. Future deployment of hyperspectral instruments on unmanned aerial vehicles could enable REE grade to be mapped at the centimeter scale across whole deposits.
DS1982-0102
1982
Black, P.Black, P.Diamonds 1982Mineral, Vol. 28, No. 2, JUNE, PP. 15-19.Australia, New South WalesDiamonds, Exploration
DS1975-0948
1979
Black, R.Black, R., Caby, R., et al.Evidence for Late Precambrian Plate Tectonics in West AfricaNature., Vol. 278, PP. 223-227.West Africa, GuineaStructure, Tectonics
DS1980-0064
1980
Black, R.Black, R.Precambrian of West AfricaEpisodes, Vol. 1980, No. 4, PP. 3-8.West Africa, Ivory Coast, Guinea, Sierra Leone, Liberia, NigeriaStructure, Tectonics
DS1985-0391
1985
Black, R.Liegeois, J.P., Black, R.Alkaline Magmatism Subsequent to Collision in the Pan African Belt of the Adar des Iforas (mali).Geological Society of America (GSA), Vol. 17, No. 3, P. 165. (abstract.).West Africa, MaliOccurrences
DS1989-0847
1989
Black, R.Lameyre, J., Black, R., Giret, A.Le magmatism alcalin: donnees geologiques sur quelques provinces oceaniques et continentales.(in French)Geological Association of Canada (GAC) Annual Meeting Program Abstracts, Vol. 14, p. A49. (abstract.)West Africa, NigeriaAlkaline rocks
DS1991-0989
1991
Black, R.Ligeois, J.P., Sauvage, J.F., Black, R.The Permo-Jurassic alkaline province of Tadhak, Mali: geology, geochronology and tectonic significanceLithos, Vol. 27, pp. 95-105GlobalAlkaline rocks, Craton
DS1993-0126
1993
Black, R.Black, R., Liegeois, J-P.Cratons, mobile belts, alkaline rocks and continental lithospheric mantle:the Pan-African testimonyJournal of the Geological Society of London, Vol. 150, pt. 1, January pp. 89-98AfricaOrogeny, Tectonics
DS1996-0723
1996
Black, R.Keiswetter, D., Black, R., Steeples, D.Seismic reflection analysis of the Manson Impact Structure, IowaJournal of Geophysical Research, Vol. 101, No. 3, March 10, pp. 5823-5834.IowaStructure, Impact structure
DS1998-0873
1998
Black, R.Liegeois, J.P., Navez, J., Hertogen, J., Black, R.Contrasting origin of post collisional high Potassium calc-alkaline and shoshonitic versus alkaline granitesLithos, Vol. 45, pp. 1-28.GlobalGeochemistry - sliding normalization, Shoshonites
DS1981-0008
1981
Black, R.A.Anderson, R.R., Black, R.A.Geophysical Interpretation of the Geology of the Central Segment of the Midcontinent.Eos, Vol. 63, No. 33, P. 615. (abstract.).GlobalMid-continent
DS1981-0085
1981
Black, R.A.Black, R.A.Geophysical Processing and Interpretation of Magsat Satellite Magnetic Anomaly Dat a Over the U.s. Midcontinent.Msc. Thesis, University Iowa., 116P.Wisconsin, KentuckyMid Continent
DS1983-0011
1983
Black, R.A.Anderson, R.R., Black, R.A.Early Proterozoic Development of the Southern Archean Boundary of the Superior Province in the Lake Superior Region.Geological Society of America (GSA), Vol. 15, No. 6, P. 515. (abstract.).GlobalMid Continent
DS1986-0126
1986
Black, R.A.Carmichael, R.S., Black, R.A.Analysis and use of Magsat satellite magnetic dat a for interpretation of crustal structure and character in the United States midcontinentPhys. Earth Planet. Science, Vol. 44, No. 4, December pp. 333-347United StatesGeophysics, Midcontinent
DS1992-0128
1992
Black, R.A.Black, R.A.Suppression of dominant topographic overprints in gravity dat a by adaptivefiltering: southern Wyoming ProvinceJournal of Geophysical Research, Vol. 97, No. B 10, September 10, pp. 14, 237-14243WyomingGeophysics -gravity, Tectonics
DS200612-1500
2006
Black, R.A.Walker, J.D., Bowers, T.D., Black, R.A., Glazner, A.F., Farmer, G.L., Carlson, R.W.A geochemical database for western North American volcanic and intrusive rocks. NAVDATIn: Sinha, A.K. Geoinformatics: data to knowledge, GSA Special Paper, 397, 397, pp.61-72United StatesGeochemistry - data
DS1998-0130
1998
Black, S.Black, S., Macdonald, R., Barreiro, Dunkley, SmithOpen system alkaline magmatism in northern Kenya: evidence from U seriesdisequilibration temperatures and radiogenic...Contributions to Mineralogy and Petrology, Vol. 131, No. 4, May pp. 364-378.KenyaGeochronology - isotopes, Alkaline rocks
DS1990-0209
1990
Black, T.C.Black, T.C., Freyberg, D.L.Simulation of one dimensional correlated fields using a matrix factorization moving average approachMath. Geol, Vol. 22, No. 1, pp. 39-62GlobalGeostatistics, Random field
DS1950-0200
1955
Black, W.A.Black, W.A.Study of Marked Positive Gravity Anomaly in the Northern Mid-continent Region of the United States.Geological Society of America (GSA) Bulletin., Vol. 66, No. 12, PT. 2, P. 1531, (abstract.).GlobalMid-continent, Geophysics
DS1960-0793
1967
Blackadar, R.G.Blackadar, R.G.Geological Reconnaissance, Southern Baffin Island, District of FranklinGeological Survey of Canada (GSC), Paper No. 66-47, 32p.Northwest Territories, Baffin IslandGeology - Bedrock, Structural
DS1970-0028
1970
Blackadar, R.G.Blackadar, R.G.Precambrian Geology Northwestern Baffin Island, District of FranklinGeological Survey of Canada (GSC), Bulletin. 191, 89p.Northwest Territories, Baffin IslandGeology - Precambrian
DS2001-0452
2001
BlackburnHarris, M.J., Symons, D.T.A., Peck, Blackburn, TurekDevelopments in the 2.1 to 1.7 Ga apparent polar wander path for the Trans-Hudson Orogen and Superior Craton.Geological Association of Canada (GAC) Annual Meeting Abstracts, Vol. 26, p.59, abstract.Manitoba, SaskatchewanTrans Hudson Orogen, Tectonics
DS1910-0163
1911
Blackburn, D.Blackburn, D., Caddell, W.W.Secret Service in South AfricaLondon: Cassell, 380P. (CHAPTER 15, PP. 321-373.).South AfricaIdb, Kimberley
DS200512-1038
2004
Blackburn, L.Stachel, T., Blackburn, L., Kurszlaukis, S., Barton, E., Walker, E.C.Diamonds from the Cristal and genesis volcanics, Wawa Ontario.32nd Yellowknife Geoscience Forum, Nov. 16-18, p.74-75. (talk)Canada, Ontario, WawaDiamond inclusions
DS201112-0090
2011
Blackburn, T.Blackburn, T., Bowring, S., Perron, T., Mahan, K., Dudas, F.A long term record of continental lithosphere exhumation via U-Pb thermochronology of the lower crust.Goldschmidt Conference 2011, abstract p.532.United States, MontanaCraton, keels
DS201112-0091
2011
Blackburn, T.Blackburn, T., Bowring, S.A., Schoene, B., Mahan, K., Dudas, F.U-Pb thermochronology: creating a temporal record of lithosphere thermal evolution.Contributions to Mineralogy and Petrology, in press, availableMantleGeothermometry - xenoliths
DS200512-0092
2004
Blackburn, T.J.Blackburn, T.J., Stockli, D., Berendsen, P., Carlson, R.W., Macpherson, G.L.New (U-TH/He) age constraints on the emplacement of kimberlite pipes in north eastern Kansas.Geological Society of America Annual Meeting ABSTRACTS, Nov. 7-10, Paper 192-2, Vol. 36, 5, p. 447.United States, KansasGeochronology, Bala. Stockdale, Tuttle, Leonardville
DS200812-0116
2008
Blackburn, T.J.Blackburn, T.J., Stockli, D.F., Carlson, R.W., Berendsen, P.U Th /He dating of kimberlites - a case study from north eastern Kansas.Earth and Planetary Science Letters, Vol. 175, 1-2, pp. 111-120.United States, KansasGeochronology - Riley
DS201112-0410
2011
Blackburn, T.J.Hanson, R.E., Rioux, M., Gose, W.A., Blackburn, T.J., Bowring, S.A., Mukwakwami, J., Jones, D.L.Paleomagnetic and geochronological evidence for large scale post 1.88 Ga displacement between Zimbabwe and Kaapvaal Cratons along the Limpopo belt.Geology, Vol.39, 5, pp. 487-490.Africa, South Africa, ZimbabweGeochronology
DS1998-0131
1998
Blackburn, W.H.Blackburn, W.H., Dennen, W.H.CD-ROM version of encyclopedia of mineral names for Macintosh and WindowusersCanadian Mineralogist Special Publ, No. 1, $ 100.00 United StatesGlobalBook - ad for CD-ROM version, Encyclopedia Mineral Names
DS201512-1898
2015
Blacklock, S.Blacklock, S.Ekati diamond mine UAVs.43rd Annual Yellowknife Geoscience Forum Abstracts, abstract p. 18.Canada, Northwest TerritoriesDeposit - Ekati

Abstract: Dominion Diamond Ekati Corporation (DDEC) purchased two unmanned aerial vehicles (UAV's) in 2014 to assist in surveying the active open pits and kimberlite stockpiles at the mine. UAV technology has allowed the team to survey various aspects of the mine in a safer and more accurate. manner. Along with making day to day work more efficient, DDEC surveying now has the ability to complete various other requests from departments at the mine. These include; large area photographs of lay downs, new road alignments, projects and environmental areas of interest.
DS1992-1087
1992
Blackman, D.K.Morgan, J.P., Blackman, D.K., Sinton, J.M.Mantle flow and melt generation at mid-Oceanic ridgesAmerican Geophysical Union (AGU) Monograph, Vol. 71, 361p. approx. $ 46.00MantleOphiolites, Basalts
DS1993-0127
1993
Blackman, D.K.Blackman, D.K., Orcutt, J.A., Forsyth, D.W., Kendall, J-M.Seismic anisotropy in the mantle beneath an oceanic spreading centreNature, Vol. 366, December 16, pp. 675-677MantleGeophysics -seismics, Mid ocean ridge
DS1994-1234
1994
Blackman, D.K.Morgan, J.P., Blackman, D.K., Sinton, J.M.Mantle flow and melt generation at mid-ocean ridgesAmerican Geophysical Union Publ, Monograph Vol. 71, 361p. $ 46.00GlobalMantle flow, Geophysics -magma
DS200612-0108
2006
Blackman, D.K.Becker, T.W., Chevrot, S., Schulte Pelkum, V., Blackman, D.K.Statistical properties of seismic anisotropy predicted by upper mantle geodynamic models.Journal of Geophysical Research, Vol. 111, B 18, B 8309.MantleGeophysics - seismics
DS200612-0109
2006
Blackman, D.K.Becker, T.W., Chevrot, S., Schulte-Pelkum, V., Blackman, D.K.Statistical properties of seismic anisotropy predicted by upper mantle geodynamic models.Journal of Geophysical Research, Vol. 111, No. B8, B08309.MantleGeophysics - seismics
DS200612-0110
2006
Blackman, D.K.Becker, T.W., Schulte-Pelkum, V., Blackman, D.K., Kellogg, J.B., O'Connell, R.J.Mantle flow under the western United States from shear wave splitting.Earth and Planetary Science Letters, in press availableUnited StatesGeophysics - seismics, tectonics, convection
DS200612-0111
2006
Blackman, D.K.Becker, T.W., Sculte Pelkum, V., Blackman, D.K., Kellogg, J.B., O Connell, R.J.Mantle flow under the western United States from shear wave splitting.Earth and Planetary Science Letters, Vol. 247, 3-4, pp. 235-251.United StatesGeodynamics
DS200712-0081
2007
Blackman, D.K.Blackman, D.K.Use of mineral physics, with geodynamic modelling and seismology to investigate flow in the Earth's mantle.Report on Progress in Physics, Institute of Physics Pub., Vol. 70, 5, pp. 659-689.MantleGeophysics - seismics
DS1999-0465
1999
BlackstoneMcMillan, M.E., Heller, P.L., Hoffower, BlackstoneIs there a northern boundary of the Colorado Plateau?Geological Society of America (GSA), Vol. 31, No. 7, p. 187. abstract.Alberta, WyomingTectonics
DS1987-0057
1987
Blackstone, D.L. Jr.Blackstone, D.L. Jr.Northern Medicine Bow Mountains, Wyoming: revision of structural northeast flankContrib. Geology, Vol. 25, No. 1, May pp. 1-9WyomingUSA, Structure
DS1970-0479
1972
Blackstone, D.L.Jr.Blackstone, D.L.Jr.Tectonic Analysis of Southwestern Wyoming from Erts-1 ImagerUniversity WYOMING REMOTE SENSING LAB. SPECIAL Report, NAS 5-21799, 4P.GlobalLeucite, Rocky Mountains, Leucite Hills
DS1983-0135
1983
Blackstone, D.L.Jr.Blackstone, D.L.Jr.Laramide Compressional Tectonics, Southeastern WyomingContrib. To Geology, Vol. 22, No. 1, PP. 1-38.United States, WyomingColorado Plateau, Rocky Mountains, Sweetwater Arch
DS1975-0242
1976
Blackstone, R.E.Blackstone, R.E.Contact Relationships of Laramie Anorthosite and Associated rocks Poe Mountain Area, Albany County, Wyoming.Msc. Thesis, University Wyoming, 164P.United States, Wyoming, Rocky MountainsRegional Studies
DS1910-0039
1910
Blackwelder, E.Darton, N.H., Blackwelder, E., Siebenthal, C.E.Laramie Sherman Folio, WyomingUnited States Geological Survey (USGS) ATLAS of THE UNITED STATES, 17P.United States, Wyoming, Rocky MountainsRegional Geology
DS1920-0273
1926
Blackwelder, E.Blackwelder, E.Precambrian Geology of the Medicine Bow MountainsGeological Society of America (GSA) Bulletin., Vol. 37, PP. 615-658.GlobalBlank
DS1930-0183
1935
Blackwelder, E.Blackwelder, E.Precambrian Rocks of Utah and WyomingUtah Academy of Science Arts And Letters, Vol. 22, PP. 153-157.GlobalBlank
DS1984-0139
1984
BlackwellBarnett, R.L., Arima, M., Blackwell, WINDER, Palmer.The Picton and Varty lake ultramafic dikes: Jurassic magmatism in the St.Lawrence platform near BellevilleCanadian Journal of Earth Sciences, Vol. 21, pp. 1460-72.OntarioLamprophyre, Kimberlite, Deposit - Varty, Picton
DS1989-1342
1989
Blackwell, D.D.Sass, J.H., Blackwell, D.D., Chapman, D.S., Costain, J.K., DeckerHeat flow from the crust of the United StatesPhysical Properties of Rocks and Minerals, Ed. Y.S. Touloukian, W.R., ISBN 0-89116-883-4 $ 95.00 548p. pp. 503-GlobalHeat flow, Mantle
DS1992-0129
1992
Blackwell, G.H.Blackwell, G.H., Sinclair, A.J.Geostatistical mineral inventory using personal computersThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin), Vol. 85, No. 961, June pp. 65-70GlobalGeostatistics, Computer programs
DS1994-0168
1994
Blackwell, G.H.Blackwell, G.H.Computerized mine planning for medium size open pitsInstitute of Mining and Metallurgy (IMM) Bulletins, pp. A 83- A 88EnglandMining, Computer programs
DS1992-1064
1992
Blackwell, G.W.Miller, A.R., Blackwell, G.W.Petrology of alkaline rare earth element bearing plutonic rocks, EnekatchaLake, and Carey Lake map areas. 65E 15 and 65 L 7.Geological Survey Canada Open File: project summaries Canada-northwest Territories agreement, OF 2484, March pp. 129-134.Northwest TerritoriesAlkaline rocks, Rare earths
DS1984-0138
1984
Blackwell, J.D.Barnett, R.L., Arima, M., Blackwell, J.D., Winder, C.G., Palmer.The Picton and Varty Lake Ultramafic Dikes: Jurassic Magmatism in the St. Lawrence Platform Near Belleville, Ontario.Canadian Journal of EARTH. SCI., Vol. 21, No. 12, DECEMBER PP. 1460-1472.Canada, OntarioBlank
DS1993-0128
1993
Blacutt, W.P.Blacutt, W.P.Risk and reward for mining investment in BoliviaSociety for Mining, Metallurgy and Exploration (SME) Meeting held February 15-18, 1993 in Reno, Nevada, Reprint No. 93-245, 8pBoliviaEconomics, Polymetallics
DS1995-0156
1995
Blacutt, W.P.Blacutt, W.P.The investment worth model: concepts and methods of estimation of modelparametersNonRenewable Resources, Vol. 4, No. 3, Fall, pp. 262-272BoliviaEconomics -mining investment, Risk management
DS1950-0416
1958
Blade, L.V.Milton, C., Blade, L.V.Preliminary Note on Kimzeyite, a New Zirconian GarnetScience., Vol. 127, No. 3310, P. 1343.United States, Gulf Coast, ArkansasMineralogy
DS1950-0425
1958
Blade, L.V.Rose, H.J.JR., Blade, L.V., Ross, M.Earthy Monazite at Magnet Cove ArkansawAmerican MINERALOGIST., Vol. 43, No. 9-10, PP. 995-997.United States, Gulf Coast, Arkansas, Hot Spring CountyPetrography
DS1960-0338
1963
Blade, L.V.Erickson, R.L., Blade, L.V.Geochemistry and Petrology of the Alkalic Igneous Complex Of Magnet Cove, Arkansaw.United States Geological Survey (USGS) PROF. PAPER., No. 425, 95P.United States, Gulf Coast, Arkansas, Hot Spring CountyGeochemistry, Petrology
DS201705-0854
2017
Blades, M.L.Merdith, A.S., Collins, A.S., Williams, S.E., Pisarevsky, S., Foden, J.F., Archibald, D., Blades, M.L., Alessio, B.L., Armistead, S., Plavsa, D., Clark, C., Muller, R.D.A full plate global reconstruction of the Neoproterozoic.Gondwana Research, in press available 155p.Gondwana, RodiniaGeodynamics

Abstract: Neoproterozoic tectonic geography was dominated by the formation of the supercontinent Rodinia, its break-up and the subsequent amalgamation of Gondwana. The Neoproterozoic was a tumultuous time of Earth history, with large climatic variations, the emergence of complex life and a series of continent-building orogenies of a scale not repeated until the Cenozoic. Here we synthesise available geological and palaeomagnetic data and build the first full-plate, topological model of the Neoproterozoic that maps the evolution of the tectonic plate configurations during this time. Topological models trace evolving plate boundaries and facilitate the evaluation of “plate tectonic rules” such as subduction zone migration through time when building plate models. There is a rich history of subduction zone proxies preserved in the Neoproterozoic geological record, providing good evidence for the existence of continent-margin and intra-oceanic subduction zones through time. These are preserved either as volcanic arc protoliths accreted in continent-continent, or continent-arc collisions, or as the detritus of these volcanic arcs preserved in successor basins. Despite this, we find that the model presented here still predicts less subduction (ca. 90%) than on the modern earth, suggesting that we have produced a conservative model and are likely underestimating the amount of subduction, either due to a simplification of tectonically complex areas, or because of the absence of preservation in the geological record (e.g. ocean-ocean convergence). Furthermore, the reconstruction of plate boundary geometries provides constraints for global-scale earth system parameters, such as the role of volcanism or ridge production on the planet's icehouse climatic excursion during the Cryogenian. Besides modelling plate boundaries, our model presents some notable departures from previous Rodinia models. We omit India and South China from Rodinia completely, due to long-lived subduction preserved on margins of India and conflicting palaeomagnetic data for the Cryogenian, such that these two cratons act as ‘lonely wanderers’ for much of the Neoproterozoic. We also introduce a Tonian-Cryogenian aged rotation of the Congo-São Francisco Craton relative to Rodinia to better fit palaeomagnetic data and account for thick passive margin sediments along its southern margin during the Tonian. The GPlates files of the model are released to the public and it is our expectation that this model can act as a foundation for future model refinements, the testing of alternative models, as well as providing constraints for both geodynamic and palaeoclimate models.
DS201709-2032
2017
Blades, M.L.Meredith, A.S., Collins, A.S., Williams, S.E., Pisarevsky, S., Foden, J.D., Archibald, D.B., Blades, M.L., Alessio, B.L., Armistead, S., Plavsa, D., Clark, C., Muller, R.D.A full plate global reconstruction of the Neoproterozoic.Gondwana Research, Vol. 50, pp. 84-134.Globalneoproterozoic

Abstract: Neoproterozoic tectonic geography was dominated by the formation of the supercontinent Rodinia, its break-up and the subsequent amalgamation of Gondwana. The Neoproterozoic was a tumultuous time of Earth history, with large climatic variations, the emergence of complex life and a series of continent-building orogenies of a scale not repeated until the Cenozoic. Here we synthesise available geological and palaeomagnetic data and build the first full-plate, topological model of the Neoproterozoic that maps the evolution of the tectonic plate configurations during this time. Topological models trace evolving plate boundaries and facilitate the evaluation of “plate tectonic rules” such as subduction zone migration through time when building plate models. There is a rich history of subduction zone proxies preserved in the Neoproterozoic geological record, providing good evidence for the existence of continent-margin and intra-oceanic subduction zones through time. These are preserved either as volcanic arc protoliths accreted in continent-continent, or continent-arc collisions, or as the detritus of these volcanic arcs preserved in successor basins. Despite this, we find that the model presented here still predicts less subduction (ca. 90%) than on the modern earth, suggesting that we have produced a conservative model and are likely underestimating the amount of subduction, either due to a simplification of tectonically complex areas, or because of the absence of preservation in the geological record (e.g. ocean-ocean convergence). Furthermore, the reconstruction of plate boundary geometries provides constraints for global-scale earth system parameters, such as the role of volcanism or ridge production on the planet's icehouse climatic excursion during the Cryogenian. Besides modelling plate boundaries, our model presents some notable departures from previous Rodinia models. We omit India and South China from Rodinia completely, due to long-lived subduction preserved on margins of India and conflicting palaeomagnetic data for the Cryogenian, such that these two cratons act as ‘lonely wanderers’ for much of the Neoproterozoic. We also introduce a Tonian-Cryogenian aged rotation of the Congo-São Francisco Craton relative to Rodinia to better fit palaeomagnetic data and account for thick passive margin sediments along its southern margin during the Tonian. The GPlates files of the model are released to the public and it is our expectation that this model can act as a foundation for future model refinements, the testing of alternative models, as well as providing constraints for both geodynamic and palaeoclimate models.
DS201904-0715
2019
Blades, M.L.Armistead, S.E., Collins, A.S., Redaa, A., Gilbert, S., Jepson, G., Gillespie, J., Blades, M.L., Foden, J.D., Razakamana, T.Structural evolution and medium temperature thermochronology of central Madagascar: implications for Gondwana amalgamation.Journal of the Geological Society of London, in press available 25p.Africa, Madagascarthermochronology

Abstract: Madagascar occupied an important place in the amalgamation of Gondwana, and preserves a record of several Neoproterozoic events that can be linked to orogenesis of the East African Orogen. We integrate remote sensing and field data to unravel complex deformation in the Ikalamavony and Itremo domains of central Madagascar. The deformation sequence comprises a gneissic foliation (S1), followed by south to south-west directed, tight to isoclinal, recumbent folding (D2). These are overprinted by north-trending upright folds that formed during a ~E-W shortening event. Together these produced type 1 and type 2 fold interference patterns throughout the Itremo and Ikalamavony domains. Apatite U-Pb and muscovite and biotite Rb-Sr thermochronometers indicate that much of central Madagascar was thermally reset to at least ~500oC at c. 500 Ma. Deformation in west-central Madagascar occurred between c. 750 Ma and c. 550 Ma, and we suggest this deformation formed in response to the c. 650 Ma collision of Azania with Africa along the Vohibory Suture in southwestern Madagascar. In eastern Madagascar, deformation is syn- to post-550 Ma, which formed in response to the final closure of the Mozambique Ocean along the Betsimisaraka Suture that amalgamated Madagascar with the Dharwar Craton of India.
DS202010-1826
2020
Blades, M.L.Armistead, S.E., Collins, A.S., Redaa, A., Jepson, G., Gillespie, J., Gilbert, S., Blades, M.L., Foden, J.D., RazakMnN, T.Structural evolution and medium temperature thermochronology of central Madagascar: implications for Gondwana amalagamation.Journal of the Geological Society, Vol. 177, pp. 784-798.Africa, Madagascargeothermometry

Abstract: Madagascar occupied an important place in the amalgamation of Gondwana and preserves a record of several Neoproterozoic events that are linked to orogenesis of the East African Orogen. In this study, we integrate remote sensing, field data and thermochronology to unravel complex deformation in the Ikalamavony and Itremo domains of central Madagascar. The deformation sequence comprises a gneissic foliation (S1), followed by south- to SW-directed, tight to isoclinal, recumbent folding (D2). These are overprinted by north-trending upright folds that formed during an approximately east-west shortening event (D3). Together these produced type 1 and type 2 fold interference patterns throughout the Itremo and Ikalamavony domains. We show that the Itremo and Ikalamavony domains were deformed together in the same orogenic system, which we interpret as the c. 630 Ma collision of Azania with Africa along the Vohibory Suture in southwestern Madagascar. In eastern Madagascar, deformation is syn- to post-550 Ma, and probably formed in response to final closure of the Mozambique Ocean along the Betsimisaraka Suture that amalgamated Madagascar with the Dharwar Craton of India. Apatite U-Pb and novel laser ablation triple quadrupole inductively coupled plasma mass spectrometry (LA-QQQ-ICP-MS) muscovite and biotite Rb-Sr thermochronology indicates that much of central Madagascar cooled through c. 500°C at c. 500 Ma.
DS202103-0394
2021
Blades, M.L.Merdith, A.S., Williams, S.E., Collins, A.S., Tetley, M.G., Mulder, J.A., Blades, M.L., Young, A., Armistead, S.E., Cannon, J., Zahirovic, S., Muller, R.D.Extending full plate tectonic models into deep time: linking the Neoproterozoic and the Phanerozoic.Earth Science Reviews, Vol. 214, 44p. PdfMantleplate tectonics

Abstract: Recent progress in plate tectonic reconstructions has seen models move beyond the classical idea of continental drift by attempting to reconstruct the full evolving configuration of tectonic plates and plate boundaries. A particular problem for the Neoproterozoic and Cambrian is that many existing interpretations of geological and palaeomagnetic data have remained disconnected from younger, better-constrained periods in Earth history. An important test of deep time reconstructions is therefore to demonstrate the continuous kinematic viability of tectonic motions across multiple supercontinent cycles. We present, for the first time, a continuous full-plate model spanning 1 Ga to the present-day, that includes a revised and improved model for the Neoproterozoic-Cambrian (1000-520 Ma) that connects with models of the Phanerozoic, thereby opening up pre-Gondwana times for quantitative analysis and further regional refinements. In this contribution, we first summarise methodological approaches to full-plate modelling and review the existing full-plate models in order to select appropriate models that produce a single continuous model. Our model is presented in a palaeomagnetic reference frame, with a newly-derived apparent polar wander path for Gondwana from 540 to 320 Ma, and a global apparent polar wander path from 320 to 0 Ma. We stress, though while we have used palaeomagnetic data when available, the model is also geologically constrained, based on preserved data from past-plate boundaries. This study is intended as a first step in the direction of a detailed and self-consistent tectonic reconstruction for the last billion years of Earth history, and our model files are released to facilitate community development.
DS202109-1481
2021
Blades, M.L.Meredith, A.S., Williams, S.E., Collins, A.S., Tetley, M.G., Mulder, J.A., Blades, M.L., Young, A., Armistead, S.E., Cannon, J., Zahirovic, S., Muller, R.D.Extending full plate tectonic models into deep time: linking the Neoproterozoic and the Phanerozoic.Earth Science Reviews , Vol. 214, 103477, 44p. PdfMantleplate tectonics, Rodinia, Gondwana

Abstract: Recent progress in plate tectonic reconstructions has seen models move beyond the classical idea of continental drift by attempting to reconstruct the full evolving configuration of tectonic plates and plate boundaries. A particular problem for the Neoproterozoic and Cambrian is that many existing interpretations of geological and palaeomagnetic data have remained disconnected from younger, better-constrained periods in Earth history. An important test of deep time reconstructions is therefore to demonstrate the continuous kinematic viability of tectonic motions across multiple supercontinent cycles. We present, for the first time, a continuous full-plate model spanning 1 Ga to the present-day, that includes a revised and improved model for the Neoproterozoic-Cambrian (1000-520 Ma) that connects with models of the Phanerozoic, thereby opening up pre-Gondwana times for quantitative analysis and further regional refinements. In this contribution, we first summarise methodological approaches to full-plate modelling and review the existing full-plate models in order to select appropriate models that produce a single continuous model. Our model is presented in a palaeomagnetic reference frame, with a newly-derived apparent polar wander path for Gondwana from 540 to 320 Ma, and a global apparent polar wander path from 320 to 0 Ma. We stress, though while we have used palaeomagnetic data when available, the model is also geologically constrained, based on preserved data from past-plate boundaries. This study is intended as a first step in the direction of a detailed and self-consistent tectonic reconstruction for the last billion years of Earth history, and our model files are released to facilitate community development.
DS1995-0051
1995
BladhAnthony, Bideau, Bladh, NicholsHandbook of mineralogyMineral Data Publishing, Vol. II, 904p. $ 135.00 plusGlobalBook -ad, Mineralogy handbook
DS1984-0309
1984
Blagodareva, N.S.Govorov, I.N., Blagodareva, N.S., Kirykhina, N.I., Kharkiv, A.D.Primary Potassium Minerals in Deep Seated Eclogites of YakutiaInternational Geology Review, Vol. 26, No. 11, November pp. 1290-1294RussiaEclogites
DS1986-0299
1986
Blagodareva, N.S.Govorov, I.N., Blagodareva, N.S., Kiryukhina, N.I., Kharkiv, A.D.Primary potassium minerals in plutonic eclogite xenoliths from YakutiaDoklady Academy of Science USSR, Earth Science Section, Vol. 276, January pp. 123-RussiaMineralogy, eclogite
DS1960-0093
1960
Blagulkina, V.A.Sarsadskikh, N.N., Rovsha, V.S., Blagulkina, V.A.Minerals of Inclusions of Pyrope Peridotites in the Kimberlites of the Daldyn-alakit Diamond Bearing Region.Vsegei, No. 40, PP. 37-55.RussiaBlank
DS1960-0217
1962
Blagulkina, V.A.Blagulkina, V.A., Rosha, V.S., Sarsadskikh, N.N.The Mineralogy of Rocks Related to KimberlitesZap. Vses. Miner. Obshch., PT. 91, No. 2, PP. 236-241.RussiaBlank
DS1960-0419
1964
Blagulkina, V.A.Artsybasheva, T.F., Blagulkina, V.A., et al.The Problem of Classification of the Yakutia Kimberlites (based on Those of the Alakit-daldynsk Diamantiferous Region).International Geology Review, Vol. 6, No. 10, PP. 1773-1781.RussiaKimberlite
DS1960-0742
1966
Blagulkina, V.A.Sarsadskikh, N.N., Blagulkina, V.A., Silin, YU. I.The Absolute Age of the Yakutian KimberlitesDoklady Academy of Sciences Nauk SSSR, Vol. 168, No. 2, PP. 420-423., RussiaBlank
DS1960-1072
1969
Blagulkina, V.A.Blagulkina, V.A.Petrochemical Types of Siberian Kimberlites and Their Diamond Capacity.In: Proceedings of The Working Conference On Petrochemistry, Moscow., RussiaBlank
DS1960-1206
1969
Blagulkina, V.A.Sarsadskikh, N.N., Blagulkina, V.A.Petrographic and Petrogenic Differences between the Kimberlites and Rocks Similar to Them in Certain Features.Zap. Vses. Miner. Obshch., PT. 98, No. 4, PP. 415-421.RussiaBlank
DS1970-0244
1971
Blagulkina, V.A.Blagulkina, V.A.The Composition of Ilmenite from KimberlitesZap. Vses. Miner. Obshch., PT. 100, PP. 194-198.RussiaBlank
DS1970-0245
1971
Blagulkina, V.A.Blagulkina, V.A.Distribution of Disseminated and Trace Elements in Kimberlites of Various Petrochemical Types.Geochemistry International, Vol. 8, No. 3, PP. 459-.RussiaBlank
DS1970-0246
1971
Blagulkina, V.A.Blagulkina, V.A.Chemical Composition of Kimberlites. #2Geochemistry International (Geokhimiya), Vol. 1971, No. 1-2, P. 152. (abstract.).Russia, YakutiaGeochemistry
DS1989-1627
1989
Blaha, J.E.Wilkinson, M.J., Blaha, J.E., Noli, D.A new lagoon on the Namibian coast of South Africa:sand spit growth documented from STS-29 shuttlephotographyGeocarto international, No. 4, pp. 63-66Southwest Africa, NamibiaRemote sensing, Geomorphology
DS201412-0056
2014
Blaikie, T.N.Blaikie, T.N., Ailleres, L., Betts, P.G., Cas, R.A.F.A geophysical comparison of the diatremes of simple and complex maar volcanoes, Newer Volcanics Province, south-eastern Australia.Journal of Volcanology and Geothermal Research, Vol. 276, pp. 64-81.AustraliaVolcanoes
DS201412-0057
2014
Blaikie, T.N.Blaikie, T.N., Ailleres, L., Betts, P.G., Cas, R.A.F.A geophysical comparison of the diatremes of simple and complex Maar volcanoes, Newer Volcanic Province, south-eastern Australia.Journal of Volcanology and Geothermal Research, Vol. 276, pp. 64-81.AustraliaGeophysics - volcanoes
DS1999-0072
1999
Blain, C.Blain, C., Wilde, A.Trends in discovery: commodity and ore type targetsNorth Atlantic Mineral Symposium, Sept., abstracts pp. 188-90.GlobalEconomics - BHP, discoveries, resources, costs, Trends, diamonds mentioned
DS1992-0130
1992
Blain, C.F.Blain, C.F.Is exploration becoming cost effective?Australian Institute of Mining and Metallurgy (AusIMM) Bulletin, No. 7, December pp. 48-55AustraliaEconomics, Exploration
DS1993-0129
1993
Blain, L.Blain, L.The challenge of analytical method selectionSociety for Mining, Metallurgy and Exploration (SME) Meeting held February 15-18, 1993 in Reno, Nevada, Reprint No. 93-112, 7pGlobalGeochemistry, Assays, analyses
DS202012-2205
2020
Blaine, J.Blaine, J.Kalahari meanderings The Falcinbridge diamond exploration story Botswana 1975-1988. https://youtu.be /07lKCVFT7LE , Oct. ppt presentationAfrica, BotswanaFalconbridge history

Abstract: 22 October 2020 Overberg Geoscientists Group talk by John Blaine
DS1991-0336
1991
Blaine, J.L.Daniels, L.R.M., Jennings, C.M.H., Lee, F.E., Blaine, J.L.The geology of the M1 kimberlite, southern BotswanaProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 58-59BotswanaExploration, Kimberlite
DS1994-0371
1994
Blaine, J.L.Daniels, L.R.M., Jennings, C.M.H., Lee, J.E., Blaine, J.L., Billington, F.R.The geology of crater volcanics and sediments associated with the M1kimberlite, southwest Botswana.Proceedings of Fifth International Kimberlite Conference, Vol. 1, pp. 129-139.BotswanaKimberlite, Deposit -M1
DS200912-0431
2009
Blaine, J.L.Lee, J.E., Jennings, C.M.H., Blaine, J.L.The GOPE 25 kimberlite discovery, Botswana, predicated on four ilmenite grains from reconnaissance soil samples: a case history.Explore, No. 143, June pp. 1-7.Africa, BotswanaCase history - GOPE 25
DS1980-0065
1980
Blair, G.Blair, G.Diamonds of the Wyoming OutbackLapidary Journal, Vol. 34, No. 2, PP. 496-498.United States, Wyoming, Colorado Plateau, State Line, Rocky MountainsProspecting
DS1985-0060
1985
Blair, K.P.Berendsen, P., Blair, K.P.The Control of Basement Related Faults on the Localization Of Hydrocarbons and Minerals Central Kansas.6th. International Conference Basement Tectonics, Held Sante Fe Septemb, P. 9. (abstract.).United States, Central States, KansasGeotectonics, Rift
DS1988-0061
1988
Blair, K.P.Blair, K.P., Berendsen, P.Structures associated with the Rose and Silver Citydomes, Wilson and Woodson counties, KansasGeological Society of America (GSA) Guidebook Fieldtrip, Berendsen, P. ed. Cretaceous, pp. 11-15KansasLamproite, Structure
DS1989-0107
1989
Blair, K.P.Berendsen, P., Blair, K.P.Geology of the mid-continent rift, northern KansasGeological Society of America (GSA) Abstract Volume, Vol. 21, No. 4, p. 4. (abstract.)GlobalTectonics
DS1989-0124
1989
Blair, K.P.Blair, K.P., Berendsen, P.Subsurface structural geology of the Joplin QuadrangleUnited States Geological Survey (USGS) Open file, United States Geological Survey (USGS)-Missouri G.S. Symp: Mineral resource potential of, p. 3. (abstract.)KansasTectonics
DS1994-0169
1994
Blair, T.C.Blair, T.C., McPherson, J.G.Alluvial fans and their natural distinction from rivers based onmorphology, hydraulic, sedimentary and faciesJournal of Sedimentary Research, Vol. A64, No. 3, July, pp. 450-489GlobalAlluvial fans, rivers, Geomorphology, Sedimentology, hydraulic, facies
DS1997-0363
1997
Blais, A.Fulton, R.J., Sun, S., Blais, A.Southern Prairies NATMAP project: surficial geology of Virden map sheetGeological Survey of Canada Forum 1997 abstracts, p. 21. AbstractAlberta, Saskatchewan, ManitobaNATMAP, Till
DS1997-0364
1997
Blais, A.Fulton, R.J., Thorleifson, L.H., Blais, A., Matile, S.S.Southern Prairies NATMAP project: a summary reportGeological Survey of Canada Forum 1997 abstracts, p. 6. AbstractGlobalSurficial geology
DS1991-1742
1991
Blais, S.Tourpin, S., Gruau, G., Blais, S., Fourcade, S.Resetting of rare earth elements (REE) and neodymium and Strontium isotopes during carbonization of a komatiite flow from FinlandChemical Geology, Vol. 90, No. 1-2 March 25, pp. 15-30FinlandKomatiite, Alteration
DS1991-1743
1991
Blais, S.Tourpin, S., Gruau, G., Blais, S., Fourcade, S.Resetting of rare earth elements (REE) and neodymium and StrontiumChemical Geology, Vol. 90, No. 1-2 March 25, pp. 15-30FinlandKomatiite, Alteration
DS202012-2249
2020
Blake, A.R.Schmetzer, K., Martayan, G., Blake, A.R.History of the Chivor emerald mine, part 2 ( 1924-1970): between insolvency and viability.Gems & Gemology, Vol. 56, 2, summer pp. 230-257. pdfSouth America, Columbiadeposit - Chivor

Abstract: The history of the Chivor emerald mine in Colombia is a saga with countless twists and turns, involving parties from across the globe. Indigenous people initially exploited the property, followed by the Spanish in the sixteenth and seventeenth centuries, before abandonment set in for 200 years. The mine was rediscovered by Francisco Restrepo in the 1880s, and ownership over the ensuing decades passed through several Colombian owners and eventually to an American company, the Colombian Emerald Syndicate, Ltd., with an intervening but unsuccessful attempt by a German group organized by Fritz Klein to take control. With the Colombian Emerald Syndicate succumbing to bankruptcy in 1923, the property was sold and then transferred in 1924 to another American firm, the Colombia Emerald Development Corporation. Under the new ownership, stock market speculation played a far more prominent role in the story than actual mining. Nonetheless, periods of more productive mining operations did take place under managers Peter W. Rainier and Russell W. Anderton. Yet these were not enough to prevent the company, renamed Chivor Emerald Mines, Inc. in 1933, from entering insolvency in 1952 and being placed into receivership. Leadership by Willis Frederick Bronkie enabled the firm to regain independence in 1970 and shortly thereafter to be sold in a series of transactions, with Chivor gradually being returned to Colombian interests.
DS1988-0062
1988
Blake, D.F.Blake, D.F., Freund, F., et al.The nature and origin of interstellar diamondNature, Vol. 332, No. 6165, April 14, pp. 611-613GlobalBlank
DS1975-0374
1976
Blake, D.H.Page, R.W., Blake, D.H., Mahon, M.W.Geochronology and Related Aspects of Acid Volcanics Associated Granites, and Other Proterozoic Rocks of the Granites-tanami Region.B.m.r. Journal of Aust. Geol. Geophys., Vol. 1, PP. 1-13.AustraliaKimberlite, Regional Geology
DS1995-0157
1995
Blake, K.L.Blake, K.L., Duckworth, R.C.Mineralization styles in the Proterozoic of SwedenShort Course Metallogeny of Proterozoic Basins, 37pSwedenMetallogeny, Proterozoic
DS1970-0880
1974
Blake, M.C.Blake, M.C., Jones, D.L.Origin of Franciscan Melanges in Northern CaliforniaSoc. Econ. Paleontologists And Mineralogists Spec. Publishing, No. 19, PP. 345-357.CaliforniaKimberlite
DS1960-1069
1969
Blake, M.C.JR.Bailey, E.H., Blake, M.C.JR.Tectonic Development of Western California in the Late Mezozoic ; Article 2, Metamorphism and its Relationship with Regional Tectonics.Geotectonics, No. 4, PP. 225-230.CaliforniaKimberlite
DS1989-1047
1989
Blake, M.C.Jr.Moore, D.E., Blake, M.C.Jr.New evidence for polyphase metamorphism of glaucophane schist and eclogite exotic blocks in the FranciscanComplex, California and OregonJournal of Metamorphic Geology, Vol. 7, No. 2, March pp. 211-228California, OregonEclogite
DS1991-0177
1991
Blake, R.Brink, S., Saini-Eidukat, B., Earley, D.III, Blake, R.Application of petrographic techniques to assess in situ leaching miningpotentialUnited States Bureau of Mines I.C., No. IC 9295, 14pUnited StatesMining -in-situ, Petrography
DS1990-0883
1990
Blake, S.Koyaguchi, T., Blake, S.The dynamics of magma mixing in a rising magma batchBulletin. Volcanology, Vol. 52, No. 2, December pp. 127-137GlobalMagma, Dynamics -mixing magma
DS200812-1036
2008
Blake, S.Self, S., Blake, S.Consequences of explosive supereruptions.Elements, Vol. 4, 1, Feb. pp. 41-46.MantleMagmatism
DS1999-0043
1999
Blake, T.S.Barley, M.E., Blake, T.S., Groves, D.I.The Mount Bruce megasequence set and eastern Yilgarn Craton: examples of late Archean and Early ProterozoicPrecambrian Research, Vol. 58, pp. 55-70.AustraliaCraton - Pilbara
DS2003-1342
2003
Blake, T.S.Strik, G., Blake, T.S., Zegers, T.E., White, S.H., Langereis, C.G.Paleomagnetism of flood basalts in the Pilbara Craton, Western Australia: Late ArcheanJournal of Geophysical Research, Vol. 108, No. B 12, Dec. 3, 10.1029/2003JB002475AustraliaGeophysics - paleomagnetics, tectonics
DS200412-1937
2003
Blake, T.S.Strik, G., Blake, T.S., Zegers, T.E., White, S.H., Langereis, C.G.Paleomagnetism of flood basalts in the Pilbara Craton, Western Australia: Late Archean continental drift and the oldest known reJournal of Geophysical Research, Vol. 108, No. B 12, Dec. 3, 10.1029/2003 JB002475AustraliaGeophysics - paleomagnetics, tectonics
DS1960-0324
1963
Blake, W.Blake, W.Notes on Glacial Geology, Northeastern District of MackenzieGeological Survey of Canada (GSC) Paper, No. 63-23, 12p.Northwest TerritoriesGeomorphology
DS1859-0124
1858
Blake, W.P.Blake, W.P.Report on the Gold Placers of Lumpkin County, Georgia and The Practicality of Working Them by Hydraulic Method.New York: J.f. Trow Publishing, 39P.United States, Georgia, AppalachiaDiamond Occurrence
DS1859-0127
1859
Blake, W.P.Blake, W.P.The Gold Placers in the Vicinity of Dahlonega GeorgiaBoston:, 63P.United States, Georgia, AppalachiaDiamond Occurrence
DS1860-0026
1866
Blake, W.P.Blake, W.P.Annotated Catalogue of the Principal Mineral Species Hitherto Recognized in California.Sacramento: Private Publishing, 31P.United States, California, West Coast, MontanaGemology
DS1860-0587
1888
Blake, W.P.Blake, W.P.Diamond MinesEngineering and Mining Journal, Vol. 45, P. 473. JUNE 30TH.Africa, South AfricaDiamond recovery
DS2003-0583
2003
Blakely, R.Hildenbrand, T.G., Keller, R.G., Blakely, R., Hinze, W.J.Need for a U.S. high altitude magnetic surveyGeological Society of America, Annual Meeting Nov. 2-5, Abstracts p. 446.United StatesGeophysics
DS200412-0827
2003
Blakely, R.Hildenbrand, T.G., Keller, R.G., Blakely, R., Hinze, W.J.Need for a U.S. high altitude magnetic survey.Geological Society of America, Annual Meeting Nov. 2-5, Abstracts p. 446.United StatesGeophysics
DS1960-0595
1965
Blakely, R.F.Rudman, A.J., Blakely, R.F.A Geophysical Study of a Basement Anomaly in IndianaGeophysics, Vol. 30, No. 5, PP. 740-761.GlobalMid-continent, Geophysics
DS1993-1371
1993
Blakely, R.J.Saltus, R.W., Blakely, R.J.HYPERMAG: an interactive 2 and 1 1/2 dimensional gravity and magnetic modeling program, version 3.5United States Geological Survey (USGS) Open file, No. 93-0287, 39p. $ 6.00GlobalComputer, Program -HYPERMAG
DS1996-0629
1996
Blakely, R.J.Hildenbrand, T.G., Blakely, R.J., Hinze, W.J., et al.Aeromagnetic survey over the U.S. to advance geomagnetic researchEos, Vol. 77, No. 28, July 9, pp. 265, 268United StatesGeophysics -aeromagnetics, Brief overview
DS2001-0984
2001
Blakely, R.J.Romanyuk, T.V., Mooney, W.D., Blakely, R.J.Cascade subduction zone, North America: a tectono geophysical modelGeotectonics, Vol. 35, No. 3, pp. 224-44.OregonSubduction zones - not specific to diamonds
DS2002-1219
2002
Blakely, R.J.Parsons, T., Blakely, R.J., Brocher, T.M.A simple algorithm for sequentially incorporating gravity observations in seismic traveltime tomography.International Geology Review, Vol. 43,12,pp. 1073-86., Vol. 43,12,pp. 1073-86.Mantle, WashingtonTomography, Gardner's rule - not specific to diamonds
DS2002-1220
2002
Blakely, R.J.Parsons, T., Blakely, R.J., Brocher, T.M.A simple algorithm for sequentially incorporating gravity observations in seismic traveltime tomography.International Geology Review, Vol. 43,12,pp. 1073-86., Vol. 43,12,pp. 1073-86.Mantle, WashingtonTomography, Gardner's rule - not specific to diamonds
DS1975-0464
1977
Blakey, G.G.Blakey, G.G.The Diamond (1977)London: Paddington Press, 280P.GlobalKimberley, Mineralogy, Classification, Description
DS201112-0337
2011
Blakey, R.C.Frisch, W., Meschede, M., Blakey, R.C.Continental drift and mountain building.Springer, 180p. $ 79.95MantleBook - tectonics
DS1992-0131
1992
Blanc, A.Blanc, A., Bernard-Griffiths, J., Caby, R., Caruba, C., Caruba, R.uranium-lead (U-Pb) (U-Pb) dating and isotopic signature of the alkaline ring complexes of BouJournal of African Earth Sciences, Vol. 14, No. 3, pp. 301-311GlobalAlkaline ring complexes, Geochronology
DS1997-1205
1997
Blanc, Ph.Verhulst, A., Demaiffe, D., Ohnenstetter, D., Blanc, Ph.Cathodluminescence petrography of carbonatites and associated alkaline silicate rocks from Kola Pen.Geological Association of Canada (GAC) Abstracts, POSTER.Russia, Kola PeninsulaCarbonatite
DS1987-0619
1987
BlancaRodriquez, C.O., Casali, R.A., Blanca, ELPY, Cappanni, O.M.1st principle prediction of structural properties and pressure dependence of the charge density and energy gaps in diamondsPhys. St.-S-B., Vol. 143, No. 1, October pp. 539-548GlobalBlank
DS200712-0225
2006
Blancaert, M.De Corte, K., Anthonis, A., Van Royen, J., Blancaert, M., Barjon, J., Willems, B.Overview of dislocation networks in natural type IIa diamonds.Gems & Gemology, 4th International Symposium abstracts, Fall 2006, p.122-3. abstract onlyTechnologyDiamond Type IIa
DS1993-1558
1993
Blanchard, D.Sutton, S.R., Bajt, S., Rivers, M.L., Smith, J.V., Blanchard, D.X-ray microprobe determination of chromium oxidation state in olivine from lunar basalt and kimberlitic diamonds.Proceedings of the Lunar and Planetary Science Conference, Vol. 24, pp. 1383-1384.GlobalGeochemistry, Microprobe
DS1987-0058
1987
Blanchard, D.P.Blanchard, D.P.Anorthosites show how crust formedGeotimes, Vol. 32, No. 6, June p. 21GlobalMantle genesis
DS1987-0343
1987
Blanchard, D.P.Kempton, P.D., Dungan, M.A., Blanchard, D.P.Petrology and geochemistry of xenolith bearing alkalic basalts from The geronimo Volcanic field, southeast Arizona, evidence for polybaric fractionation and implicatMantle metasomatism and alkaline magmatism, edited E. Mullen Morris and, No. 215, pp. 347-370ArizonaAnalyses p. 356-7-8
DS201810-2351
2018
Blanchard, I.Mahan, B., Siebert, J., Blanchard, I., Moynier, F.Investigating Earth's formation history through copper & sulfur metal silicate partitioning during core-mantle differentiation.Journal of Geophysical Research: Solid Earth, doi:10.1029/2018JB015991Mantlecore mantle boundary

Abstract: Experiments wherein molten metal and silicate (rock?building) phases un?mix themselves due to their physical properties, i.e. metal?silicate partitioning, can be conducted at the high temperatures and pressures (HP?HT) that characterized Earth's differentiation into a core and mantle. The redistribution of elements between the metal and silicate phases ? their partitioning ? during this process can be measured and mathematically described, then placed into numerical models to better understand Earth's formation history. Here, we have mathematically characterized the HP?HT partitioning of copper, combined this with results for sulfur from literature, and input these characterizations into numerical models that track their distribution between Earth's core and mantle as it grows to its present mass. Copper and sulfur were chosen because they display different sensitivities to the physical mechanisms that govern planetary formation, and we can leverage this to better understand Earth's formation and differentiation history. Our results indicate that ~75% of Earth's precursor materials grew incrementally from relatively small bits of material ? on average ~0.1% of Earth's mass or less ? that is most compositionally similar to meteorite classes that are made up of iron?rich metal and silicate solids (chondrules) that are depleted in easily vaporized (volatile) elements, especially sulfur.
DS201902-0258
2018
Blanchard, I.Badro, J., Aubert, J., Hirose, K., Nomura, R., Blanchard, I., Borensztajn, S., Siebert, J.Magnesium partitioning between Earth's mantle and core and its potential to drive an early exsolution geodynamo.Geophysical Research Letters, Vol. 45, 24, pp. 13,240-13,248.Mantlegeodynamics

Abstract: We measure the incorporation of magnesium oxide (one of the main components of Earth's mantle) into iron (the main constituent Earth's core), using extremely high pressure and temperature experiments that mimic the conditions of Earth's mantle and core. We find that magnesium oxide dissolution depends on temperature but not on pressure, and on metal (i.e., core) composition but not silicate (i.e., mantle) composition. Our findings support the idea that magnesium oxide dissolved in the core during its formation will precipitate out during subsequent core cooling. The precipitation should stir the entire core to produce a magnetic field in Earth's distant past, at least as intense as the present?day field.
DS202104-0585
2021
Blanchard, I.Kubik, E., Siebert, J., Blanchard, I., Agranier, A., Mahan, B., Moynier, F.Earth's volatile accretion as told by Cd, Bi, Sb and Ti core-mantle distribution.Geochimica et Cosmochimica Acta, in press available, 35p. PdfMantlegeodynamics
DS201908-1776
2019
Blanchard, J.A.Ernst, R.E., Liikane, D.A., Jowitt, S.M., Buchan, K.L., Blanchard, J.A.A new plumbing system framework for mantle plume related continental large igneous provinces and their mafic ultramafic intrusions.Journal of Volcanology and Geothermal Research, in press available 34p. PdfGlobalmantle plumes, hotspots

Abstract: The magmatic components of continental Large Igneous Provinces (LIPs) include flood basalts and their plumbing system of giant mafic dyke swarms (radiating, linear, and the recently discovered circumferential type), mafic sill provinces, a lower crustal magmatic underplate, mafic-ultramafic (M-UM) intrusions, associated silicic magmatism, and associated carbonatites and kimberlites. This paper proposes a new plumbing system framework for mantle plume-related continental LIPs that incorporates all of these components, and provides a context for addressing key thematic aspects such as tracking magma batches "upstream" and "downstream" and their geochemical evolution, assessing the setting of M-UM intrusions and their economic potential, interpreting deep magmatic component identified by geophysical signatures, and estimating magnitudes of extrusive and intrusive components with climate change implications. This plumbing system model, and its associated implications, needs to be tested against the rapidly improving LIP record.
DS200412-0160
2004
Blanchard, M.Blanchard, M., Ingrin, J.Kinetics of deuteration in pyrope.European Journal of Mineralogy, Vol. 16, 4,pp. 567-576.TechnologyMineralogy
DS201910-2249
2019
Blanchard, M.Chasse, M., Blanchard, M., Cabareta, D., Juhin, A., Vantelon, D., Griffin, W.L., O'Reilly, S.Y., Calas, G.Deciphering molecular-scale mechanisms covering scandium dynamics in the critical zone. Goldschmidt2019, in press available, 71 ppt.Australialaterites

Abstract: Scandium is often considered as immobile during chemical weathering, based on its low solubility. In contrast to other conservative (i.e. relatively immobile) elements incorporated into accessory minerals resistant to weathering (e.g. zirconium, thorium or niobium), the scarcity of scandium minerals indicates that the processes accounting for scandium's immobilisation are distinctive. However, the evolution of scandium speciation during weathering is unknown, limiting the understanding of the processes controlling its dynamics in the critical zone. Exceptional scandium concentrations in east Australian laterites provide the possibility of unravelling these mechanisms. We follow scandium speciation through thick lateritic profiles (> 30 m) using a multiscale mineralogical and spectroscopic approach involving electron microprobe, laser-ablation--inductively coupled plasma mass spectrometry, selective leaching and X-ray absorption near-edge structure spectroscopy, complemented by mass-transfer calculations. We show that the initial reservoir of scandium contained in the parent rock is preserved under reducing conditions occurring in the lowest horizons of the profiles. The dissolution of scandium-bearing clinopyroxene generates smectitic clays that immobilise and concentrate scandium. It is subsequently trapped in the lateritic duricrust by goethite. Scandium mobilisation appears in this horizon and increases upward as a result of the dissolution of goethite, possibly assisted by dissolved organic matter, and the precipitation of hematite. Molecular-scale analyses demonstrate that changes in speciation govern scandium dynamics, with substitution in smectitic clays and adsorption on iron oxyhydroxides playing a crucial role in scandium immobility in the saprolite and lower lateritic duricrust. The higher affinity of scandium for goethite relative to hematite drives scandium mobilisation in the upper lateritic duricrust, leading to its concentration downward in the lower lateritic duricrust. These successive mechanisms illustrate how the unique complexity of the critical zone leads to scandium concentrations that may form new types of world-class scandium deposits. Comparison with conservative elements and with rare-earth elements, expected to have similar geochemical properties, emphasizes the unique behaviour of scandium in the critical zone. While scandium remains immobile during the early stages of weathering, intense and long-term alteration processes, observed in lateritic contexts, lead to scandium mobilisation. This study highlights the dependence of scandium mobility on weathering conditions.
DS202004-0503
2020
Blanchard, M.Chasse, M., Blanchard, M., Cabaret, D., Vantelon, D., Juan, A., Calas, G.First principles modeling of X-ray absorption spectra enlightens the process of scandium sequestration by iron oxides.American Mineralogist, Vol. 105, 7, 10.2138/am-2020-730Globalscandium

Abstract: Scandium is often associated with iron oxides in the environment. Despite the use of scandium as a geochemical tracer and the existence of world-class supergene deposits, uncertainties on speciation obscure the processes governing its sequestration and concentration. Here, we use first-principles approaches to interpret experimental K-edge X-ray absorption near-edge structure spectra of scandium either incorporated in or adsorbed on goethite and hematite, at concentrations relevant for the environment. This modeling helps to interpret the characteristic spectral features, providing key information to determine scandium speciation when associated with iron oxides. We show that scandium is substituted into iron oxides at low concentration without modifying the crystal structure. When scandium is adsorbed onto iron oxide surfaces, the process occurs through outer-sphere complexation with a reduction in the coordination number of the hydration shell. Considering available X-ray absorption spectra from laterites, the present results confirm that scandium adsorption onto iron oxides is the dominant mechanism of sequestration in these geochemical conditions. This speciation explains efficient scandium recovery through mild metallurgical treatments of supergene lateritic ores. The specificities of scandium sorption mechanisms are related to the preservation of adsorbed scandium in million-years old laterites. These results demonstrate the emerging ability to precisely model fine X-ray absorption spectral features of trace metals associated with mineral phases relevant to the environment. It opens new perspectives to accurately determine trace metals speciation from high-resolution spatially-resolved X-ray absorption near-edge structure spectroscopy in order to constrain the molecular mechanisms controlling their dynamics.
DS1960-0924
1968
Blanchard, R.Blanchard, R.Interpretation of Leached OutcropsNevada Bureau of Mines, Bulletin 66, 180pNevadaWeathering, Book -table Of Contents
DS1991-0599
1991
Blanchard, Y.B.Grasty, R.L., Holman, P.B., Blanchard, Y.B.Transportable calibration pads for ground and airborne gamma rayspectrometersGeological Survey of Canada Paper, No. 90-23, 25pCanadaSpectrometry, Program -PADWIN.
DS202112-1920
2021
Blanchard. I.Blanchard. I., Abeykon, S., Frost, D.J., Rubie, D.C.Sulfur content at sulfide saturation of peridotitic melt at upper mantle conditions.American Mineralogist, Vol. 106, pp. 1835-1843. pdfMantlesulfides

Abstract: The concentration of sulfur that can be dissolved in a silicate liquid is of fundamental importance because it is closely associated with several major Earth-related processes. Considerable effort has been made to understand the interplay between the efects of silicate melt composition and its capacity to retain sulfur, but the dependence on pressure and temperature is mostly based on experiments performed at pressures and temperatures below 6 GPa and 2073 K. Here we present a study of the effects of pressure and temperature on sulfur content at sulfide saturation of a peridotitic liquid. We performed 14 multi-anvil experiments using a peridotitic starting composition, and we produced 25 new measurements at conditions ranging from 7 to 23 GPa and 2173 to 2623 K. We analyzed the recovered samples using both electron microprobe and laser ablation ICP-MS. We compiled our data together with previously published data that were obtained at lower P-T conditions and with various silicate melt compositions. We present a new model based on this combined data set that encompasses the entire range of upper mantle pressure-temperature conditions, along with the efect of a wide range of silicate melt compositions. Our findings are consistent with earlier work based on extrapolation from lower-pressure and lower-temperature experiments and show a decrease of sulfur content at sulfide saturation (SCSS) with increasing pressure and an increase of SCSS with increasing temperature. We have extrapolated our results to pressure-temperature conditions of the Earth’s primitive magma ocean, and show that FeS will exsolve from the molten silicate and can efectively be extracted to the core by a process that has been termed the "Hadean Matte." We also discuss briefly the implications of our results for the lunar magma ocean.
DS2001-0097
2001
BlanchiniBeccaluva, L., Blanchini, Coltori, Perkins, Siena, et al.Multistage evolution of the European lithospheric mantle: new evidence from Sardinian peridotite xenolithContribution Mineralogy Petrology, Vol. 142, No. 3, pp. 284-97.Sardinia, EuropePeridotite xenoliths
DS201708-1567
2017
Blanchini, G.Blanchini, G., Bodinier, J-L., Braga, R., Wilson, M.The crust mantle and lithosphere-asthenosphere boundaries: insights from xenoliths, orogenic deep sections, and geophysical studies. 2 Chapters citedGeological Society of London, book - cost approx. 43 lbsMantlexenoliths
DS1982-0319
1982
Bland, A.E.Keller, G.R., Bland, A.E., Greenberg, J.K.Evidence for a Major Late Precambrian Tectonic Event (rifting?) in the Eastern Midcontinent Region, United States.Tectonics, Vol. 1, No. 2, PP. 213-223.GlobalMid-continent, Peralkaline
DS201809-2046
2018
Bland, P.A.Johnson, T.E., Gardiner, N.J., Miljkovic, K., Spencer, C.J., Kirkland, C.L., Bland, P.A., Smithies, R.H.Are Earth's oldest felsic rocks impact melts? Acasta Gneiss ComplexGoldschmidt Conference, 1p. AbstractCanada, Northwest Territoriesmeteorite

Abstract: Earth’s oldest felsic rocks, the 4.02 billion-year-old Idiwhaa gneisses of the Acasta Gneiss Complex, northwest Canada, have compositions that are distinct from the felsic rocks that typify Earth’s ancient continental nuclei, implying they formed through a different process. Using phase equilibria and trace element modelling, we show that the Idiwhaa gneisses were produced by partial melting of ironrich amphibolite host rocks at very low pressures, equating to the uppermost ~3 km of mafic crust. The heat required for such shallow melting is most easily explained through meteorite impacts. Hydrodynamic impact modelling shows that, not only is this scenario physically plausible, but the region of shallow melting appropriate to formation of the Idiwhaa gneisses would have been widespread. Given the predicted high flux of meteorites during the late Hadean, impact melting may have been the predominant mechanism that generated Hadean felsic rocks.
DS201811-2561
2018
Bland, P.A.Cox, M.A., Cavosie, A.J., Bland, P.A., Miljkovic, K., Wingate, M.T.D.Microstructural dynamics of central uplifts: reidite offset by zircon twins at the Woodleigh impact structure, Australia.Geology, doi.org/10.1130/G45127.1 4p.Australiacrater

Abstract: Impact cratering is a dynamic process that is violent and fast. Quantifying processes that accommodate deformation at different scales during central uplift formation in complex impact structures is therefore a challenging task. The ability to correlate mineral deformation at the microscale with macroscale processes provides a critical link in helping to constrain extreme crustal behavior during meteorite impact. Here we describe the first high-pressure-phase-calibrated chronology of shock progression in zircon from a central uplift. We report both shock twins and reidite, the high-pressure ZrSiO4 polymorph, in zircon from shocked granitic gneiss drilled from the center of the >60-km-diameter Woodleigh impact structure in Western Australia. The key observation is that in zircon grains that contain reidite, which forms at >30 GPa during the crater compression stage, the reidite domains are systematically offset by later-formed shock deformation twins (?20 GPa) along extensional planar microstructures. The {112} twins are interpreted to record crustal extension and uplift caused by the rarefaction wave during crater excavation. These results provide the first physical evidence that relates the formation sequence of both a high-pressure phase and a diagnostic shock microstructure in zircon to different cratering stages with unique stress regimes that are predicted by theoretical and numerical models. These microstructural observations thus provide new insight into central uplift formation, one of the least-understood processes during complex impact crater formation, which can produce many kilometers of vertically uplifted bedrock in seconds.
DS201811-2582
2018
Bland, P.A.Johnson, T.E., Gardiner, N.J., Miljkovic, K., Spencer, C.J., Kirkland, C.L., Bland, P.A., Smithies, H.An impact melt origin for Earth's oldest known evolved rocks. Acasta GneissNature Geoscience, Vol. 11, pp. 795-799.Canada, Northwest Territoriesmelting

Abstract: Earth’s oldest evolved (felsic) rocks, the 4.02-billion-year-old Idiwhaa gneisses of the Acasta Gneiss Complex, northwest Canada, have compositions that are distinct from the felsic rocks that typify Earth’s ancient continental nuclei, implying that they formed through a different process. Using phase equilibria and trace element modelling, we show that the Idiwhaa gneisses were produced by partial melting of iron-rich hydrated basaltic rocks (amphibolites) at very low pressures, equating to the uppermost ~3?km of a Hadean crust that was dominantly mafic in composition. The heat required for partial melting at such shallow levels is most easily explained through meteorite impacts. Hydrodynamic impact modelling shows not only that this scenario is physically plausible, but also that the region of shallow partial melting appropriate to formation of the Idiwhaa gneisses would have been widespread. Given the predicted high flux of meteorites in the late Hadean, impact melting may have been the predominant mechanism that generated Hadean felsic rocks.
DS1860-0177
1872
Blanford, W.T.Blanford, W.T.Notes on the Sandstones of the Godavari Valley, GolapolIndia Geological Survey Records, Vol. 5, PT. 1. P. 27.India, GolcondaDiamond Occurrence
DS1860-0653
1890
Blanford, W.T.Blanford, W.T.The Anniversary Address of the PresidentQuarterly Journal of Geological Society, Vol. 46, PP. 43-110.Africa, South Africa, South America, BrazilTectonics
DS201212-0262
2012
Blangy, S.Grimwood, B.S.R., Doubleday, N.C., Ljubicic, G.J., Donaldson, S.G., Blangy, S.Engaged acclimatization: towards responsible community based participatory research in Nunavut.Canadian Geographer, in press availableCanada, NunavutCSR - neologism
DS201112-0811
2011
BlankPolyakov, S.N., Denisov, V.N., Kuzmin, N.V., Kuznetsov, M.S., Martyushov, S.Yu., Nosukhin, Terentiev, BlankCharacterization of top quality type IIa synthetic diamonds for new x-ray optics.Diamond and Related Materials, Vol. 20, no. 5-6m pp. 726-728.TechnologyDiamond - synthesis applications
DS1920-0429
1929
Blank, E.W.Blank, E.W.Diamonds in the United States; 1929Rocks And Minerals, Vol. 4, PP. 37-40.United States, Great Lakes, Gulf Coast, West Coast, Rocky MountainsDiamond Occurrence
DS1930-0056
1931
Blank, E.W.Blank, E.W.Arkansaw Has Yielded Some Fine DiamondsNational Jeweller., Vol. 27, JANUARY PP. 44-46.United States, Gulf Coast, Arkansas, PennsylvaniaBlank
DS1930-0102
1932
Blank, E.W.Blank, E.W.The Synthesis of the DiamondRocks And Minerals, Vol. 7, P. 143.GlobalSynthetic Diamond
DS1930-0152
1934
Blank, E.W.Blank, E.W.Diamonds in KentuckyRocks And Minerals, Vol. 9, No. 11, PP. 163-164.Appalachia, KentuckyDiamond Occurrence
DS1930-0153
1934
Blank, E.W.Blank, E.W.Diamond Finds in the United States #1Rocks And Minerals, Vol. 9, PP. 10-12; PP. 23-26; PP. 29-40; PP. 147-150; PP. 16United States, Great Lakes, Appalachia, Kentucky, North Carolina, AlabamaDiamond Occurrences, History
DS1930-0184
1935
Blank, E.W.Blank, E.W.Diamond Finds in the United States #2Rocks And Minerals, Vol. 10, PP. 7-10; PP. 23-26; PP. 39-40.United States, Gulf Coast, Arkansas, Great LakesDiamond Occurrence
DS1990-0210
1990
Blank, H.R.Blank, H.R., Kucks, R.P.Preliminary aeromagnetic, gravity and generalized geologic maps of the United States Geological Survey (USGS) Basin and Range-Colorado plateau transition zone study area in southwestUtah, NevadaUnited States Geological Survey (USGS) Open File, No. 89-0432, 16p. 3 oversize sheets 1: 250, 000Colorado Plateau, UtahGeophysics -magnetics, gravity, Map
DS202103-0400
2021
Blank, V.Popov, M., Bondarenko, M., Kulnitskiy, B., Zholudev, S., Blank, V., Terentyev, S.Impulse laser cutting of diamond accompanied by phase transitions to fullerene -type onion.Diamond & Related Materials, Vol. 113, 108281, 6p. PdfGlobalraman spectroscopy
DS200712-0082
2007
Blank, V.D.Blank, V.D., Kuznetsov, M.S., Nosukhin, S.A., Terentiev, S.A., Denisov, V.N.The influence of crystallization temperature and boron concentration in growth environment on its distribution in growth sectors of type IIb diamond.Diamond and Related Materials, Vol. 16, 4-7, pp. 800-804.TechnologyType II diamond
DS200812-0725
2008
Blank, V.D.Mavrin, S.A., Denisov, V.N., Popova, D.M., Skryleva, Kuznetsov, Nosukhin, Terentiev, Blank,V.D.Boron distribution in the subsurface region of heavily doped IIb type diamond.Physics and Chemistry of the Earth Parts A,B,C, Vol. 372, 21, pp. 3914-3918.TechnologyType IIb diamonds
DS201901-0008
2018
Blank, V.D.Blank, V.D., Churkin, V.D., Kulnitsky, B.A., Perezhogin, I.A., Kirichenko, A.N., Erohin, S.V., Sorokin, P.B., Popov, M.Y.Pressure induced transformation of graphite and diamond to onions.Crystals MDPI, Vol. 8, 2, 8p. Doi.org/10.3390/cryst8020068Russiacarbon nanotubes

Abstract: In this study, we present a number of experiments on the transformation of graphite, diamond, and multiwalled carbon nanotubes under high pressure conditions. The analysis of our results testifies to the instability of diamond in the 55-115 GPa pressure range, at which onion-like structures are formed. The formation of interlayer sp3-bonds in carbon nanostructures with a decrease in their volume has been studied theoretically. It has been found that depending on the structure, the bonds between the layers can be preserved or broken during unloading.
DS1995-0392
1995
Blankenburg, F.Von.Davies, J.H., Blankenburg, F.Von.Slab breakoff: a model of lithosphere detachment and magmatism and deformation of collisional orogensEarth Planetary Science Letters, Vol. 129, No. 1-4, Jan. pp. 85-102MantleSudbduction, Tectonics, orogeny
DS202102-0175
2020
Blanks, D.E.Blanks, D.E., Holwell, D.A., Fiorentini, M.L., Moroni, M., Giuliani, A., Tassara, S., Gonzales-Jiminez, J.M., Boyce, A.J., Ferrari, E.Fluxing of mantle carbon as a physical agent for metallogenic fertilization of the crust.Nature Communications, doi.org/10.1038/ s41467-020-18157-6 11p. Pdf Mantlecarbon

Abstract: Magmatic systems play a crucial role in enriching the crust with volatiles and elements that reside primarily within the Earth’s mantle, including economically important metals like nickel, copper and platinum-group elements. However, transport of these metals within silicate magmas primarily occurs within dense sulfide liquids, which tend to coalesce, settle and not be efficiently transported in ascending magmas. Here we show textural observations, backed up with carbon and oxygen isotope data, which indicate an intimate association between mantle-derived carbonates and sulfides in some mafic-ultramafic magmatic systems emplaced at the base of the continental crust. We propose that carbon, as a buoyant supercritical CO2 fluid, might be a covert agent aiding and promoting the physical transport of sulfides across the mantle-crust transition. This may be a common but cryptic mechanism that facilitates cycling of volatiles and metals from the mantle to the lower-to-mid continental crust, which leaves little footprint behind by the time magmas reach the Earth’s surface.
DS1992-1427
1992
Blanpied, M.L.Sleep, N.H., Blanpied, M.L.Creep, compaction and the weak rheology of major faultsNature, Vol. 359, No. 6397, October 22, pp. 687-692GlobalStructure, Fault
DS1987-0442
1987
Blarez, E.Mascle, J., Blarez, E.Evidence for transform margin evolution from the Ivory Coast Ghanacontinental marginNature, Vol.326, No. 6111, March 26, pp. 378-380GhanaWest Africa, Craton
DS1988-0443
1988
Blarez, E.Mascle, J., Blarez, E., Marinho, M.The shallow structures of the Guinea and Ivory Coast-Ghana transformmargins: their bearing on the equatorial Atlantic Mesozoic evolutionTectonophysics, Vol. 155, No. 1-4, Dec. 1, pp. 193-210GhanaStructure
DS2002-1025
2002
Blass, U.McCammon, C.A., Beccero, A.I., Lauterbach, S., Blass, U., Marion, S.Oxygen vacancies in perovskite and related structures: implications for the lower mantle.Materials Research Society Symposium Proceedings, Vol. 718, pp. 109-114. Ingenta 1025440383MantlePerovskite
DS1920-0325
1927
Blatchford, T.Blatchford, T.The Geology of Portions of the Kimberley Division with Special Reference to the Fitzroy Basin and the Possibilities of The Occurrence of Minerals and Oil.Western Australia Geological Survey Bulletin, No. 93. PP. 20-21.Australia, Western AustraliaLeucite, Lamproite
DS1900-0053
1901
Blatchley, W.S.Blatchley, W.S.Diamond Reported in 1876-1877 Near MorgantownLetter To G.f. Kunz, APRIL 1ST.United States, Indiana, Great LakesDiamond Occurrence
DS1900-0309
1905
Blatchley, W.S.Blatchley, W.S.Diamond in Indiana. #1Letter To G.f. Kunz, JUNE 24TH.United States, Indiana, Great LakesDiamond Occurrence, Diamonds Notable
DS1960-0325
1963
Blatchley, W.S.Blatchley, W.S.Gold and Diamonds in IndianaIndiana Geological Survey Annual Report, No. 27, 51P.GlobalDiamond Occurrence
DS1982-0184
1982
Blatt, H.Ehlers, E.G., Blatt, H.Carbonatites, Kimberlites and Related RocksSan Francisco: W.h. Freeman, Petrology -igneous, Sedimentary, PP. 240-244.GlobalGenesis
DS1994-1049
1994
Blatt, H.Loomis, J., Weaver, B., Blatt, H.Geochemistry of Mississippian tuffs from the Ouachita Mountains, implications for tectonics Ouachita orogenGeological Society of America (GSA) Bulletin., Vol. 106, No. 9, Sept. pp. 1158-1171.Arkansas, OklahomaTectonics, Ouachita Orogen
DS201707-1377
2017
Blatter, D.Turner, M., Turner, S., Blatter, D., Maury, R., Perfit, M., Yogodzinski, G.Water contents of clinopyroxenes from sub-arc mantle peridotitesIsland Arc, in press available 2p.Europe, Francemassif

Abstract: One poorly constrained reservoir of the Earth's water budget is that of clinopyroxene in metasomatised, mantle peridotites. This study presents reconnaissance Sensitive High-Resolution, Ion Microprobe–Stable Isotope (SHRIMP–SI) determinations of the H2O contents of (dominantly) clinopyroxenes in rare mantle xenoliths from four different subduction zones, i.e. Mexico, Kamchatka, Philippines, and New Britain (Tabar-Feni island chain) as well as one intra-plate setting (western Victoria). All of the sub-arc xenoliths have been metasomatised and carry strong arc trace element signatures. Average measured H2O contents of the pyroxenes range from 70 ppm to 510?ppm whereas calculated bulk H2O contents range from 88 ppm to 3?737?ppm if the variable presence of amphibole is taken into account. In contrast, the intra-plate, continental mantle xenolith from western Victoria has higher water contents (3?447?ppm) but was metasomatised by alkali and/or carbonatitic melts and does not carry a subduction-related signature. Material similar to the sub-arc peridotites can either be accreted to the base of the lithosphere or potentially be transported by convection deeper into the mantle where it will lose water due to amphibole breakdown.
DS1998-0132
1998
Blatter, D.L.Blatter, D.L., Carmichael, S.E.Hornblende peridotite xenoliths from central Mexico reveal highly oxidized nature of subarc upper mantle.Geology, Vol. 26, No. 11, Nov. pp. 1035-38.MexicoXenoliths
DS201702-0196
2016
Blattler, C.L.Blattler, C.L., Kump, L.R., Fischer, W.W., Paris, G., Kasbohm, J.J.Constraints on ocean carbonate chemistry and pco2 in the Archean and Paleoproterozoic.Nature Geoscience, Vol. 10, pp. 41-45.GlobalGeochemistry

Abstract: One of the great problems in the history of Earth’s climate is how to reconcile evidence for liquid water and habitable climates on early Earth with the Faint Young Sun predicted from stellar evolution models. Possible solutions include a wide range of atmospheric and oceanic chemistries, with large uncertainties in boundary conditions for the evolution and diversification of life and the role of the global carbon cycle in maintaining habitable climates. Increased atmospheric CO2 is a common component of many solutions, but its connection to the carbon chemistry of the ocean remains unknown. Here we present calcium isotope data spanning the period from 2.7 to 1.9 billion years ago from evaporitic sedimentary carbonates that can test this relationship. These data, from the Tumbiana Formation, the Campbellrand Platform and the Pethei Group, exhibit limited variability. Such limited variability occurs in marine environments with a high ratio of calcium to carbonate alkalinity. We are therefore able to rule out soda ocean conditions during this period of Earth history. We further interpret this and existing data to provide empirical constraints for carbonate chemistry of the ancient oceans and for the role of CO2 in compensating for the Faint Young Sun.
DS202109-1472
2021
Blattler, C.L.Hoffman, P.F., Halverson, G.P., Schrag, D.P., Higgins, J.A., Domack, E.W., Macdonald, F.A., Pruss, S.B., Blattler, C.L., Crockford, P.W., Hodgin, E.B., Bellefroid, E.J., Johnson, B.W., Hodgskiss, M.S.W., Lamothe, K.G., LoBianco, S.J.C., Busch, J.F., HowesSnowballs in Africa: sectioning a long-lived Neoproterozoic carbonate platform and its bathyal foreslope ( NW Namibia). (Octavi Group)Earth Science Reviews , Vol. 219, 103616 231p. PdfAfrica, NamibiaCraton - Congo

Abstract: Otavi Group is a 1.5-3.5-km-thick epicontinental marine carbonate succession of Neoproterozoic age, exposed in an 800-km-long Ediacaran?Cambrian fold belt that rims the SW cape of Congo craton in northern Namibia. Along its southern margin, a contiguous distally tapered foreslope carbonate wedge of the same age is called Swakop Group. Swakop Group also occurs on the western cratonic margin, where a crustal-scale thrust cuts out the facies transition to the platformal Otavi Group. Subsidence accommodating Otavi Group resulted from S?N crustal stretching (770-655?Ma), followed by post-rift thermal subsidence (655-600?Ma). Rifting under southern Swakop Group continued until 650-635?Ma, culminating with breakup and a S-facing continental margin. No hint of a western margin is evident in Otavi Group, suggesting a transform margin to the west, kinematically consistent with S?N plate divergence. Rift-related peralkaline igneous activity in southern Swakop Group occurred around 760 and 746?Ma, with several rift-related igneous centres undated. By comparison, western Swakop Group is impoverished in rift-related igneous rocks. Despite low paleoelevation and paleolatitude, Otavi and Swakop groups are everywhere imprinted by early and late Cryogenian glaciations, enabling unequivocal stratigraphic division into five epochs (period divisions): (1) non-glacial late Tonian, 770-717?Ma; (2) glacial early Cryogenian/Sturtian, 717-661?Ma; (3) non-glacial middle Cryogenian, 661-646?±?5?Ma; (4) glacial late Cryogenian/Marinoan, 646?±?5-635?Ma; and (5) non-glacial early Ediacaran, 635-600?±?5?Ma. Odd numbered epochs lack evident glacioeustatic fluctuation; even numbered ones were the Sturtian and Marinoan snowball Earths. This study aimed to deconstruct the carbonate succession for insights on the nature of Cryogenian glaciations. It focuses on the well-exposed southwestern apex of the arcuate fold belt, incorporating 585?measured sections (totaling >190?km of strata) and?>?8764 pairs of ?13C/?18Ocarb analyses (tabulated in Supplementary On-line Information). Each glaciation began and ended abruptly, and each was followed by anomalously thick ‘catch-up’ depositional sequences that filled accommodation space created by synglacial tectonic subsidence accompanied by very low average rates of sediment accumulation. Net subsidence was 38% larger on average for the younger glaciation, despite its 3.5-9.3-times shorter duration. Average accumulation rates were subequal, 4.0 vs 3.3-8.8?m Myr?1, despite syn-rift tectonics and topography during Sturtian glaciation, versus passive-margin subsidence during Marinoan. Sturtian deposits everywhere overlie an erosional disconformity or unconformity, with depocenters ?1.6?km thick localized in subglacial rift basins, glacially carved bedrock troughs and moraine-like buildups. Sturtian deposits are dominated by massive diamictite, and the associated fine-grained laminated sediments appear to be local subglacial meltwater deposits, including a deep subglacial rift basin. No marine ice-grounding line is required in the 110 Sturtian measured sections in our survey. In contrast, the newly-opened southern foreslope was occupied by a Marinoan marine ice grounding zone, which became the dominant repository for glacial debris eroded from the upper foreslope and broad shallow troughs on the Otavi Group platform, which was glaciated but left nearly devoid of glacial deposits. On the distal foreslope, a distinct glacioeustatic falling-stand carbonate wedge is truncated upslope by a glacial disconformity that underlies the main lowstand grounding-zone wedge, which includes a proximal 0.60-km-high grounding-line moraine. Marinoan deposits are recessional overall, since all but the most distal overlie a glacial disconformity. The Marinoan glacial record is that of an early ice maximum and subsequent slow recession and aggradation, due to tectonic subsidence. Terminal deglaciation is recorded by a ferruginous drape of stratified diamictite, choked with ice-rafted debris, abruptly followed by a syndeglacial-postglacial cap-carbonate depositional sequence. Unlike its Sturtian counterpart, the post-Marinoan sequence has a well-developed basal transgressive (i.e., deepening-upward) cap dolomite (16.9?m regional average thickness, n?=?140) with idiosyncratic sedimentary features including sheet-crack marine cements, tubestone stromatolites and giant wave ripples. The overlying deeper-water calci-rhythmite includes crystal-fans of former aragonite benthic cement ?90?m thick, localized in areas of steep sea-floor topography. Marinoan sequence stratigraphy is laid out over ?0.6?km of paleobathymetric relief. Late Tonian shallow-neritic ?13Ccarb records were obtained from the 0.4-km-thick Devede Fm (~770-760?Ma) in Otavi Group and the 0.7-km-thick Ugab Subgroup (~737-717?Ma) in Swakop Group. Devede Fm is isotopically heavy, +4-8‰ VPDB, and could be correlative with Backlundtoppen Fm (NE Svalbard). Ugab Subgroup post-dates 746?Ma volcanics and shows two negative excursions bridged by heavy ?13C values. The negative excursions could be correlative with Russøya and Garvellach CIEs (carbon isotope excursions) in NE Laurentia. Middle Cryogenian neritic ?13C records from Otavi Group inner platform feature two heavy plateaus bracketed by three negative excursions, correlated with Twitya (NW Canada), Taishir (Mongolia) and Trezona (South Australia) CIEs. The same pattern is observed in carbonate turbidites in distal Swakop Group, with the sub-Marinoan falling-stand wedge hosting the Trezona CIE recovery. Proximal Swakop Group strata equivalent to Taishir CIE and its subsequent heavy plateau are shifted bidirectionally to uniform values of +3.0-3.5‰. Early Ediacaran neritic ?13C records from Otavi Group inner platform display a deep negative excursion associated with the post-Marinoan depositional sequence and heavy values (??+?11‰) with extreme point-to-point variability (?10‰) in the youngest Otavi Group formation. Distal Swakop Group mimics older parts of the early Ediacaran inner platform ?13C records, but after the post-Marinoan negative excursion, proximal Swakop Group values are shifted bidirectionally to +0.9?±?1.5‰. Destruction of positive and negative CIEs in proximal Swakop Group is tentatively attributed to early seawater-buffered diagenesis (dolomitization), driven by geothermal porewater convection that sucks seawater into the proximal foreslope of the platform. This hypothesis provocatively implies that CIEs originating in epi-platform waters and shed far downslope as turbidites are decoupled from open-ocean DIC (dissolved inorganic carbon), which is recorded by the altered proximal Swakop Group values closer to DIC of modern seawater. Carbonate sedimentation ended when the cratonic margins collided with and were overridden by the Atlantic coast-normal Northern Damara and coast-parallel Kaoko orogens at 0.60-0.58?Ga. A forebulge disconformity separates Otavi/Swakop Group from overlying foredeep clastics. In the cratonic cusp, where the orogens meet at a right angle, the forebulge disconformity has an astounding ?1.85?km of megakarstic relief, and km-thick mass slides were displaced gravitationally toward both trenches, prior to orogenic shortening responsible for the craton-rimming fold belt.
DS200412-0161
2003
Blauer, E.Blauer, E.Mining at any cost.New York Diamonds, January pp. 40-47.Africa, NamibiaMining - abstract in Gems and Gemology Spring p. 75.
DS200412-0162
2003
Blauer, E.Blauer, E.One hundred years of digging. Premier mine.New York Diamonds, Vol. 76, May pp. 61-66.Africa, South AfricaHistory
DS1960-0425
1964
Bleackley, D.Bleackley, D., Workman, D.R.Reconnaissance Mineral Survey of BasutolandOverseas Geol. Institute Report, No. 3.LesothoDiamonds, Geology
DS1860-0017
1865
Bleasdale, J.J.Bleasdale, J.J.On Precious Stones in Victoria. Beechworth, CollingwoodTransactions of the Royal Society , Vol. 6, PP. 99-100.Australia, VictoriaDiamond Occurrence
DS1860-0027
1866
Bleasdale, J.J.Bleasdale, J.J.A Report on the Results of an Exhibition of Gems BeechwoodTransactions of the Royal Society , Vol. 7, PP. 67-68.Australia, VictoriaDiamond Occurrence
DS1860-0047
1867
Bleasdale, J.J.Bleasdale, J.J.Notes sur Les Gemmes et Les Pierres Precieuses Trouvees Dans Victoria.Melbourne: Masterman., 15P.Australia, VictoriaDiamond Occurrence
DS1960-0519
1965
Blecha, M.Blecha, M.Geology of the Tribag MineThe Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Bulletin., Vol. 68, PP. 321-326.GlobalBreccia
DS200812-0898
2008
BleekerPietranik, A.B, Hawkesworth, C.J., Storey, C.D., Kemp, T.I.S., Sircombe, Whitehouse, BleekerEpisodic, mafic crust formation in the Slave Craton, Canada.Goldschmidt Conference 2008, Abstract p.A748.Canada, Northwest TerritoriesMantle zircons
DS1995-0158
1995
Bleeker, W.Bleeker, W., Beaumont-Smith, C.Thermal structural studies in Slave Province: preliminaryresults, implications Yellowknife domain.Geological Survey of Canada, Paper 1995-C, pp. 87-96.Northwest TerritoriesStructure, Yellowknife domain
DS1998-0899
1998
Bleeker, W.Lucas, S., Hajnal, Z., White, D., Bleeker, W., AnsdellCrustal growth and continental collisions in the 1.9-1.8 Ga Trans HudsonOrogen, Manitoba and SaskatchewanGeological Society of America (GSA) Annual Meeting, abstract. only, p.A46.Manitoba, SaskatchewanTectonic, Trans Hudson Orogen
DS1998-1408
1998
Bleeker, W.Stern, R.A., Bleeker, W.Age of the world's oldest rocks refined using Canada's SHRIMP: the Acasta Gneiss Complex, northwest Territories.Geoscience Canada, Vol. 25, No. 1, March pp. 27-32Northwest TerritoriesGeochronology - SHRIMP, Acasta Gneiss
DS1999-0073
1999
Bleeker, W.Bleeker, W., Davis, W.J.Archean terrane boundaries: the view from the Slave ProvinceGeological Association of Canada (GAC) Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC)., Vol. 24, p. 11. abstractNorthwest TerritoriesCraton, Structure
DS1999-0074
1999
Bleeker, W.Bleeker, W., Davis, W.J.The 1991-96 NATMAP Slave Province Project: introductionCanadian Journal of Earth Sciences, Vol. 36, No.7, July pp. 1033-42.Northwest TerritoriesMapping, structure
DS1999-0075
1999
Bleeker, W.Bleeker, W., Ketchum, J.W.J., Davis, W.J.The Central Basement Complex Part II: age and tectonic significance of high strain zones along basement-coverCanadian Journal of Earth Sciences, Vol. 36, No.7, July pp. 1111-39.Northwest TerritoriesMapping, structure
DS2001-0113
2001
Bleeker, W.Bleeker, W.Evolution of the Slave Craton and the search for supercratonsGeological Association of Canada (GAC) Annual Meeting Abstracts, Vol. 26, p.14, abstract.Northwest TerritoriesCraton - Dharwar Zimbabwe, Wyoming, Yilgarn
DS2001-0114
2001
Bleeker, W.Bleeker, W.Archean cratons of Laurentia and the search for early supercratonsSlave-Kaapvaal Workshop, Sept. Ottawa, 7p. abstractNorthwest Territories, OntarioCraton - geodynamics, Slave
DS2001-0591
2001
Bleeker, W.Ketchum, J., Bleeker, W.4.03-2.85 Ga growth and modification of the Slave proto craton northwesternCanada.Slave-Kaapvaal Workshop, Sept. Ottawa, 4p. abstractNorthwest TerritoriesGeochronology, Craton
DS2001-0593
2001
Bleeker, W.Ketchum, J.W.F., Bleeker, W.Crustal recycling and growth in the Slave Protocraton, northwest Canada: 4.03-2.80 Ga.Geological Association of Canada (GAC) Annual Meeting Abstracts, Vol. 26, p.77, abstract.Northwest TerritoriesTectonics, Archean Slave Craton - Acasta gneisses
DS2001-1083
2001
Bleeker, W.Sircombe, K.N., Bleeker, W., Stern, R.A.Detrital zircon geochronology and grain size analysis a 2800 Ma Mesoarchean proto-cratonic cover successionEarth and Planetary Science Letters, Vol. 189, No. 3-4, July 15, pp. 207-220.Northwest TerritoriesCraton - Slave, Geochronology
DS2002-0165
2002
Bleeker, W.Bleeker, W.From Kenorland to Laurentia? a review of evidenceGac/mac Annual Meeting, Saskatoon, Abstract Volume, P.11., p.11.GlobalTectonics
DS2002-0166
2002
Bleeker, W.Bleeker, W.From Kenorland to Laurentia? a review of evidenceGac/mac Annual Meeting, Saskatoon, Abstract Volume, P.11., p.11.GlobalTectonics
DS2002-0167
2002
Bleeker, W.Bleeker, W.Archean tectonics: a review, with illustrations from the Slave CratonGeological Society of London Special Publication, No. 199, pp. 151-182.Northwest TerritoriesTectonics
DS2002-1706
2002
Bleeker, W.White, D.J., Lucas, S.B., Bleeker, W., Hajnal, Z., Lewry, J.F., Zwanzig, H.V.Suture zone geometry along an irregular Paleoproterozoic margin: the Superior boundary zone, Manitoba, Canada.Geology, Vol.30,8,Aug.pp.735-8.ManitobaTectonics
DS2003-0119
2003
Bleeker, W.Bleeker, W.The Late Archean record: a puzzle in ca. 35 piecesLithos, Vol. 71, 2-4, pp. 99-134.Globalgeochronology
DS2003-0320
2003
Bleeker, W.Davis, W.J., Jones, A.G., Bleeker, W., Grutter, H.Lithosphere development in the Slave Craton: a linked crustal and mantle perspectiveLithos, Vol. 71, 2-4, pp. 575-589.Northwest Territories, NunavutTectonics
DS2003-1070
2003
Bleeker, W.Peter, J., Bleeker, W., Hulbert, J., Kerr, D., Ernst, R., Knight, R., Wright, D.Slave Province minerals and geosciemce compilation and synthesis project31st Yellowknife Geoscience Forum, p. 79. (abst.)Nunavut, Northwest TerritoriesOverview
DS200412-0163
2003
Bleeker, W.Bleeker, W.The Late Archean record: a puzzle in ca. 35 pieces.Lithos, Vol. 71, 2-4, pp. 99-134.Globalgeochronology
DS200412-0421
2003
Bleeker, W.Davis, W.J., Jones, A.G., Bleeker, W., Grutter, H.Lithosphere development in the Slave Craton: a linked crustal and mantle perspective.Lithos, Vol. 71, 2-4, pp. 575-589.Canada, NunavutTectonics
DS200412-1524
2004
Bleeker, W.Percival, J.A., Bleeker, W., Cook, E.A., Rivers, T., Ross, G., Van Staal, C.PanLithoprobe Workshop IV: intra orogen correlations and comparative orogenic anatomy.Geoscience Canada, Vol. 31, 1, pp. 23-39.Canada, United StatesTectonics, Precambrian, geochronology, orogens
DS200412-1533
2003
Bleeker, W.Peter, J., Bleeker, W., Hulbert, J., Kerr, D., Ernst, R., Knight, R., Wright, D., Anglin, L.Slave Province minerals and geosciemce compilation and synthesis project.31st Yellowknife Geoscience Forum, p. 79. (abst.)Canada, Nunavut, Northwest TerritoriesOverview
DS200512-0093
2004
Bleeker, W.Bleeker, W.Taking the pulse of the Earth: a proposal for a new multidisciplinary flagship project in Canadian Solid Earth Sciences.Geoscience Canada, Vol. 31, 4, Dec, pp. 190.Lithoprobe, magmatism, paleo-continental, Superior
DS200512-0094
2005
Bleeker, W.Bleeker, W.In the beginning: Canadian shield and early continental crust.GAC Annual Meeting Halifax May 15-19, Abstract 1p.CanadaLaurentia, tectonics, Rodinia
DS200512-0095
2004
Bleeker, W.Bleeker, W.Slave bedrock compilation.32nd Yellowknife Geoscience Forum, Nov. 16-18, p.6-7. (talk)Canada, Northwest TerritoriesStructure - not specific to diamonds
DS200512-0519
2004
Bleeker, W.Ketchum, J.W.F., Bleeker, W., Stern, R.A.Evolution of an Archean basement complex and its autochthonous cover, southern Slave Province, Canada.Precambrian Research, Vol. 135, 3, Nov. 30, pp. 149-176.Canada, Northwest TerritoriesMagmatism, geochronology
DS200812-0899
2008
Bleeker, W.Pietranik, A.B., Hawkesworth, C.J., Storey, C.D., Kemp, A.I.S., Sircombe, K.N., Whitehouse, M.J., Bleeker, W.Episodic mafic crust formation from 4.5 to 2.8 Ga: new evidence from detrital zircons, Slave craton, Canada.Geology, Vol. 36, 11, pp. 875-878.Canada, Northwest TerritoriesGeochronology
DS201012-0056
2010
Bleeker, W.Bleeker, W.The use of hand held magnetic susceptibility meters in the field: an invaluable tool in regional studies of dyke swarms.International Dyke Conference Held Feb. 6, India, 1p. AbstractTechnologyGeophysics - magnetics
DS201012-0057
2010
Bleeker, W.Bleeker, W., Ernst, R.E.The anatomy of large dyke swarms: geometrical constraints on ancient break-up events.International Dyke Conference Held Feb. 6, India, 1p. AbstractGlobalLIP
DS201012-0077
2010
Bleeker, W.Buchan, K.L., Ernst, R.E., Bleeker, W., Davis, W.J., Villeneuve, M., Van Breeman, O., Hamilton, SoderlundMap of Proterozoic magmatic events in the Slave Craton, Wopmay Orogen and environs, Canadian Shield.International Dyke Conference Held Feb. 6, India, 1p. AbstractCanada, Northwest TerritoriesMagmatism
DS201012-0184
2010
Bleeker, W.Ernst, R.E, Bleeker, W.Large igneous provinces LIPS, giant dyke swarms, and mantle plumes: significance for breakup events within Canada and adjacent regions from 2.5 Ga.Canadian Journal of Earth Sciences, Vol. 47, 5, pp. 695-739.GlobalHotspots
DS201012-0185
2010
Bleeker, W.Ernst, R.E., Bleeker, W., Soderlund, U., Hamilton, M.A., Sylvester, P.J., Chamberlain, K.R.Using the global dolerite dyke swarm record to reconstruct supercontinents back to 2.7 Ga.International Dyke Conference Held Feb. 6, India, 1p. AbstractGlobalPangea
DS201012-0387
2010
Bleeker, W.Kilian, T.M., Mitchell, R.N., Bleeker, W., Le Cheminant, A.N., Chamberlain, K.R., Evans, D.A.D.Paleomagnetism of mafic dykes from the Wyoming craton, USA.International Dyke Conference Held Feb. 6, India, 1p. AbstractUnited StatesCraton, connections
DS201012-0511
2010
Bleeker, W.Mitchell, R.N., Van Breeman, O., Buchan, K.L., Le Cheminant, T.N., Bleeker, W., Evans, D.A.D.Supercratons at the ends of Early Proterozoic Earth: reconstruction of Slave, Superior, and Kaapvaal cratons at 2200-2000 Ma.International Dyke Conference Held Feb. 6, India, 1p. AbstractCanada, Africa, South AfricaKenorland
DS201112-0092
2011
Bleeker, W.Bleeker, W.The Slave Craton of North America: an overview.Geological Society of America, Annual Meeting, Minneapolis, Oct. 9-12, abstractCanada, United StatesGeochronology, petrology
DS201312-0248
2013
Bleeker, W.Ernst, R.E., Bleeker, W., Soderlund, U., Kerr, A.C.Large igneous provinces and supercontinents: toward completing the plate tectonic revolution.Lithos, Vol. 174, pp. 1-14.PangeaLIP
DS201606-1099
2016
Bleeker, W.Kilian, T.M., Bleeker, W., Chamberlain. K., Evans, D.A.D., Cousens, B.Paleomagnetism, geochronology and geochemistry of the Paleoproterozoic Rabbit Creek and Powder River dyke swarms: implications for Wyoming in supercraton Superia.Geological Society of London Special Publication Supercontinent Cycles through Earth History., Vol. 424, pp. 15-45.United States, Wyoming, Colorado PlateauSupercontinents
DS201607-1295
2016
Bleeker, W.Ernst, R.E., Hamilton, M.A., Soderlund, U., Hanes, J.A., Gladkochub, D.P., Okrugin, A.V., Kolotilina, T., Mekhonoshin, A.S., Bleeker, W., LeCheminant, A.N., Buchan, K.L., Chamberlain, K.R., Didenko, A.N.Long lived connection between southern Siberia and northern Laurentia in the Proterozoic.Nature Geoscience, Vol. 9, 6, pp. 464-469.Canada, RussiaProterozoic

Abstract: Precambrian supercontinents Nuna-Columbia (1.7 to 1.3 billion years ago) and Rodinia (1.1 to 0.7 billion years ago) have been proposed. However, the arrangements of crustal blocks within these supercontinents are poorly known. Huge, dominantly basaltic magmatic outpourings and intrusions, covering up to millions of square kilometres, termed Large Igneous Provinces, typically accompany (super) continent breakup, or attempted breakup and offer an important tool for reconstructing supercontinents. Here we focus on the Large Igneous Province record for Siberia and Laurentia, whose relative position in Nuna-Columbia and Rodinia reconstructions is highly controversial. We present precise geochronology—nine U -Pb and six Ar -Ar ages—on dolerite dykes and sills, along with existing dates from the literature, that constrain the timing of emplacement of Large Igneous Province magmatism in southern Siberia and northern Laurentia between 1,900 and 720 million years ago. We identify four robust age matches between the continents 1,870, 1,750, 1,350 and 720 million years ago, as well as several additional approximate age correlations that indicate southern Siberia and northern Laurentia were probably near neighbours for this 1.2-billion-year interval. Our reconstructions provide a framework for evaluating the shared geological, tectonic and metallogenic histories of these continental blocks.
DS201610-1878
2016
Bleeker, W.Kilian, T.M., Chamberlain, K.R., Evans, D.A.D., Bleeker, W., Cousens, B.L.Wyoming on the run - toward final Paleoproterozoic assembly of Laurentia.Geology, Vol. 44, 10, pp. 863-866.United States, Wyoming, Colorado PlateauCraton, Nuna, Slave, Superior

Abstract: Paleoproterozoic suture zones mark the formation of supercontinent Nuna and provide a record of North America's assembly. Conspicuously young ages (ca. 1.715 Ga) associated with deformation in southeast Wyoming craton argue for a more protracted consolidation of Laurentia, long after peak metamorphism in the Trans-Hudson orogen. Using paleomagnetic data from the newly dated 1899 ± 5 Ma Sourdough mafic dike swarm (Wyoming craton), we compare the relative positions of Wyoming, Superior, and Slave cratons before, during, and after peak metamorphism in the Trans-Hudson orogen. With these constraints, we refine a collisional model for Laurentia that incorporates Wyoming craton after Superior and Slave cratons united, redefining the Paleoproterozoic sutures that bind southern Laurentia.
DS201706-1066
2017
Bleeker, W.Chamberlain, K.R., Killian, T.M., Evans, D.A.D., Bleeker, W., Cousens, B.L.Wyoming on the run - toward final Paleoproterozoic assembly of Laurentia. Geology Forum Comment, April 1p.United Statescraton

Abstract: Paleoproterozoic suture zones mark the formation of supercontinent Nuna and provide a record of North America's assembly. Conspicuously young ages (ca. 1.715 Ga) associated with deformation in southeast Wyoming craton argue for a more protracted consolidation of Laurentia, long after peak metamorphism in the Trans-Hudson orogen. Using paleomagnetic data from the newly dated 1899 ± 5 Ma Sourdough mafic dike swarm (Wyoming craton), we compare the relative positions of Wyoming, Superior, and Slave cratons before, during, and after peak metamorphism in the Trans-Hudson orogen. With these constraints, we refine a collisional model for Laurentia that incorporates Wyoming craton after Superior and Slave cratons united, redefining the Paleoproterozoic sutures that bind southern Laurentia.
DS201706-1085
2016
Bleeker, W.Kilian, T.M., Chamberlain, K.R., Evans, D.A.D., Bleeker, W., Cousens, B.L.Wyoming on the run - toward final Paleoproterozoic assembly of Laurentia. Geology, Vol. 44, pp. 863-866.United Statescraton

Abstract: Paleoproterozoic suture zones mark the formation of supercontinent Nuna and provide a record of North America’s assembly. Conspicuously young ages (ca. 1.715 Ga) associated with deformation in southeast Wyoming craton argue for a more protracted consolidation of Laurentia, long after peak metamorphism in the Trans-Hudson orogen. Using paleomagnetic data from the newly dated 1899 ± 5 Ma Sourdough mafic dike swarm (Wyoming craton), we compare the relative positions of Wyoming, Superior, and Slave cratons before, during, and after peak metamorphism in the Trans-Hudson orogen. With these constraints, we refine a collisional model for Laurentia that incorporates Wyoming craton after Superior and Slave cratons united, redefining the Paleoproterozoic sutures that bind southern Laurentia.
DS201809-2028
2018
Bleeker, W.Gong, Z., Xu, X., Evans, D.A.D., Hoffman, P.F., Mitchell, R.N., Bleeker, W.Paleomagnetism and rock magnetism of the ca. 1.87 Ga Pearson Formation, Northwest Territories, Canada: a test of vertical axis rotation within the Great Slave Basin.Precambrian Research , Vol. 305C, pp. 295-309.Canada, Northwest Territoriesgeophysics

Abstract: A geometrically quantitative plate-kinematic model, based on paleomagnetism, for the initial assembly of Laurentia has taken form in the past few decades. Within this framework, there remains but one problematic interval of data predominantly from the Slave craton, which is the 1.96-1.87?Ga Coronation apparent polar wander path (APWP). The Coronation APWP shows large (?110°) back-and-forth oscillations that are difficult to explain in terms of plate motion. Nonetheless, poles from the Coronation APWP have been incorporated in various paleogeographic reconstructions of Laurentia and the supercontinent Nuna, pointing to the importance of testing its veracity. In this study, we conducted a detailed paleomagnetic and rock magnetic study of the ca. 1.87?Ga Pearson Formation, East Arm of Great Slave Lake, Northwest Territories, Canada. Our results show that Pearson Formation yields a characteristic remanent magnetization carried by single-domain or small pseudo-single-domain magnetite. The age of the magnetization is constrained to be older than Paleoproterozoic deformation and is interpreted as primary. Paleomagnetic declinations reveal a one-to-one correlation with local structural attitudes, indicating that some small blocks in the fold belt likely experienced significant (?60°) vertical-axis rotations, presumably related to large dextral displacements along the McDonald Fault system. Alternative explanations, such as true polar wander or a non-dipole magnetic field, are considered less parsimonious for the data presented here. It is suspected that some existing Christie Bay Group poles (the Stark and Tochatwi Formations), which were sampled in areas with anomalous structural attitudes and differ from time-equivalent poles obtained from areas of the Slave craton far from major transcurrent faults, may similarly suffer from vertical-axis rotation. We suggest further study before using possibly rotated Christie Bay Group poles for paleogeographic reconstructions.
DS201812-2828
2018
Bleeker, W.Kastek, N., Ernst, R.E., Cousens, B.L., Kamo, S.L., Bleeker, W., Soderlund, U., Baragar, W.R.A., Sylvester, P.U-Pb geochronology and geochemistry of the Povungnituk Group of the Cape Smith Belt: part of a craton scale circa 2.0 Ga Minto-Povungnituk Large Igneous Province, northern Superior craton. Lithos, Vol. 320-321, pp. 315-331.Canada, Quebeccarbonatite

Abstract: Magmatism of the Povungnituk Group of the Cape Smith Belt, northern Superior craton, was formed in three stages: (i)early alkaline magmatism and associated carbonatites (undated), (ii) a main flood basalt sequence (Beauparlant Formation) (constrained between 2040 and 1991?Ma), and (iii) a late stage alkaline pulse (Cecilia Formation) (ca. 1959?Ma). We suggest that the main stage of magmatic activity (middle pulse) was of short duration. A new UPb baddeleyite age of 1998?±?6?Ma is obtained from a dolerite sill intruding the uppermost section of the Beauparlant Formation. This age has regional significance because it matches the previously obtained 1998?±?2?Ma age for the Watts Group (Purtuniq) ophiolite of the northern Cape Smith Belt and the 1998?±?2?Ma?U-Pb age of the Minto dykes intruding the craton to the south. These coeval units, along with additional units correlated on paleomagnetic grounds (Eskimo Formation), are interpreted to define a large igneous province (LIP), extending over an area of >400,000?km2, which we herein define as the Minto-Povungnituk LIP. Geochemical comparison between the Watts Group ophiolite, Minto dykes and the mafic Povungnituk Group shows significant differences allowing these data to be divided into two groups and domains within the LIP. A northern domain, comprising the Povungnituk and Watts groups, shows mixing between a depleted mantle source and a more enriched mantle plume-sourced melt. A southern domain comprising the Minto dykes and the paleomagnetically linked Eskimo Formation shows signs of an even more enriched source, while these magmas also show the effect of crustal contamination. Two distinct source mechanisms can be responsible for the observed geochemical differences between the two domains. First, a difference in lithospheric sources, where melting of different portions of Superior craton lithosphere caused the different melt signatures in the interior of the craton. In this case magmatism in the two domains is only related by having the same heat source (e.g.,a mantle plume) interpreted to be located on the northwestern side of the northern Superior craton. Second, two distinct deep mantle sources that remained separated within the ascending plume. This is analogous to some current hotspots interpreted to sample both large low shear velocity provinces (LLSVP) and adjacent ambient deep mantle. This latter interpretation would allow for the use of bilateral chemistry in LIPs as a potential tool for the recognition and mapping of the LLSVP boundaries throughout Earth's history.
DS201905-1077
2018
Bleeker, W.Soderlund, U., Bleeker, W., Demirer, K., Srivastava, R.K., Hamilton, M., Nilsson, M., Personen, L.J., Samal, A.K., Jayananda, M., Ernst, R.E., Srinivas, M.Emplacement ages of Paleoproterozoic mafic dyke swarms in eastern Dharwar craton, India: implications for paleoreconstructions and support for a ~30 degree change in dyke trends from south to north.Precambrian Research, doi.org/10.1016/ j.precamres.2018.12.017Indiacraton

Abstract: Large igneous provinces (LIPs) and especially their dyke swarms are pivotal to reconstruction of ancient supercontinents. The Dharwar craton of southern Peninsular India represents a substantial portion of Archean crust and has been considered to be a principal constituent of Superia, Sclavia, Nuna/Columbia and Rodinia supercontinents. The craton is intruded by numerous regional-scale mafic dyke swarms of which only a few have robustly constrained emplacement ages. Through this study, the LIP record of the Dharwar craton has been improved by U-Pb geochronology of 18 dykes, which together comprise seven generations of Paleoproterozoic dyke swarms with emplacement ages within the 2.37-1.79 Ga age interval. From oldest to youngest, the new ages (integrated with U-Pb ages previously reported for the Hampi swarm) define the following eight swarms with their currently recommended names: NE-SW to ESE-WNW trending ca. 2.37 Ga Bangalore-Karimnagar swarm. N-S to NNE-SSW trending ca. 2.25 Ga Ippaguda-Dhiburahalli swarm. N-S to NNW-SSE trending ca. 2.22 Ga Kandlamadugu swarm. NW-SE to WNW-ESE trending ca. 2.21 Ga Anantapur-Kunigal swarm. NW-SE to WNW-ESE trending ca. 2.18 Ga Mahbubnagar-Dandeli swarm. N-S, NW-SE, and ENE-WSW trending ca. 2.08 Ga Devarabanda swarm. E-W trending 1.88-1.89 Ga Hampi swarm. NW-SE ca. 1.79 Ga Pebbair swarm. Comparison of the arcuate trends of some swarms along with an apparent oroclinal bend of ancient geological features, such as regional Dharwar greenstone belts and the late Archean (ca. 2.5 Ga) Closepet Granite batholith, have led to the hypothesis that the northern Dharwar block has rotated relative to the southern block. By restoring a 30° counter clockwise rotation of the northern Dharwar block relative to the southern block, we show that pre-2.08 Ga arcuate and fanning dyke swarms consistently become approximately linear. Two possible tectonic models for this apparent bending, and concomitant dyke rotations, are discussed. Regardless of which deformation mechanisms applies, these findings reinforce previous suggestions that the radial patterns of the giant ca. 2.37 Ga Bangalore-Karimnagar dyke swarm, and probably also the ca. 2.21 Ga Anantapur-Kunigal swarm, may not be primary features.
DS202006-0916
2020
Bleeker, W.Davey, S.C., Bleeker, W., Kamo, S.L., Vuollo, J., Ernst, R.E., Cousens, B.L.Archean block rotation in western Karelia: resolving dyke swarm patterns in metacraton Karelia-Kola for a refined paleogeographic reconstruction of supercraton Superia.Lithos, in press available 95p. PdfRussia, Kola Peninsulacraton

Abstract: Rifting, breakup, and subsequent collision related to the ca. 1.92-1.79?Ga Svecofennian orogeny fragmented and deformed the western margin of the Archean Karelia-Kola craton into four crustal blocks: Pudasjärvi, Iisalmi, Kuhmo, and Taivalkoski. Detailed quantification of Svecofennian deformation is limited due to poorly exposed basement geology and an as yet incomplete dyke swarm record. New U-Pb ID-TIMS geochronological results on baddeleyite and zircon are presented for three key mafic dykes from the Pudasjärvi block, namely the Uolevinlehto, Myllykangas, and Sipojuntti dykes. The age of the 325°-trending Uolevinlehto dyke is estimated at ca. 2400?±?12?Ma from discordant multigrain baddeleyite fractions, showing it to be younger than ca. 2450?Ma dykes across Karelia. The 350°-trending Myllykangas dyke has a minimum age of 2135.2?+?3.6/?3.7?Ma based on chemically abraded zircon. Results from single baddeleyite grains provide a precise upper intercept age of 2128.9?±?1.2?Ma for the 320°-trending Sipojuntti dyke. Our new U-Pb ages are integrated with those from the literature to define six major dyke swarms in the Pudasjärvi block: the WNW-trending ca. 2.45?Ga Pääjärvi, NW-trending ca. 2.40?Ga Uolevinlehto, NW-trending ca. 2.13-2.10?Ga Tohmajärvi, WNW-trending ca. 2.07?Ga Palomaa, NNW-trending ca. 1.98?Ga Paukkajanvaara and undated"East-West" dykes. Trends of contemporaneous dyke swarms in the Taivalkoski and Kuhmo blocks, however, are systematically offset by 35°. With subvertical dips, offset dyke swarms record 35° clockwise vertical-axis rotation of the Pudasjärvi block relative to the interior of Karelia, consistent with dextral transpression during the Svecofennian orogeny. Structural restoration of the Pudasjärvi blocks improves the constraints on regional dyke swarm patterns, and these are used to revise the position of the Karelia-Kola craton within the context of the paleogeographic reconstruction of supercraton Superia.
DS1996-0138
1996
Bleichert-Toft, J.Bleichert-Toft, J., Arndt, N.T., Ludden, J.N.Precambrian alkaline magmatismLithos, Vol. 37, No. 2-3, April 1, pp. 97-112.GlobalMagmatism -alkaline
DS200812-0117
2008
Bleischwitz, R.Bleischwitz, R., Bringezu, S.Global governance for sustainable resource management.Minerals & Energy - Raw Materials Report, Vol. 28, 2, pp. 84-101.GlobalGovernance
DS2003-0474
2003
Bleisteiner, B.Glinnemann, J., Kusaka, K., Harris, J., Bleisteiner, B., Winkler, B.Oriented graphite single crystal inclusions in diamond8ikc, Www.venuewest.com/8ikc/program.htm, Session 3, POSTER abstractNorthwest TerritoriesDiamonds - inclusions, Deposit - Panda
DS1900-0054
1901
Bleloch, W.E.Bleloch, W.E.The New South Africa, Its Value and DevelopmentNew York: Doubleday, Page And Co., 435P.Africa, South AfricaMineral Resources, Mining Engineering
DS1900-0535
1907
Bleloch, W.E.Bleloch, W.E.The Pniel Estate. Geology and Possibilities DescribedSouth Africa Mines, FEBRUARY 9TH. 3P.Africa, South AfricaGeology
DS200612-0528
2006
BlenkinsopHanson, R.E., Harmer,Blenkinsop, Bullen, Dalziel, Gose, Hall, Kampunzu, Key, Mukwakwami, Munyaniwa, Pancake, Seidel, WardMesoproterozoic intraplate magmatism in the Kalahari Craton: a review.Journal of African Earth Sciences, In press available,Africa, South AfricaAlkaline rocks, carbonatite, Premier kimberlite cluster
DS1985-0056
1985
Blenkinsop, J.Bell, K., Blenkinsop, J.Carbonatites- Clues to Mantle EvolutionGeological Society of America (GSA), Vol. 17, No. 3, FEBRUARY P. 151. (abstract.).Canada, OntarioSuperior Crust, Isotope
DS1985-0721
1985
Blenkinsop, J.Wen, J., Bell, K., Blenkinsop, J.Strontium and Neodymium Isotopic Relationships in the Oka Carbonatite comp Lex, Canada.Geological Society of America (GSA), Vol. 17, No. 7, P. 747. (abstract.).Canada, QuebecGeochronology
DS1986-0063
1986
Blenkinsop, J.Bell, K., Blenkinsop, J.Carbonatites and the sub continental upper mantleGeological Association of Canada (GAC) Annual Meeting, Vol. 11, p. 44. (abstract.)East AfricaGeochronology, Carbonatite
DS1986-0313
1986
Blenkinsop, J.Grunenfelder, M.H., Tilton, G.R., Bell, K., Blenkinsop, J.Lead and strontium isotope relationship in the Oka carbonatitecomplex, QuebecGeochimica et Cosmochimica Acta, Vol. 50, pp. 461-468Quebec, UgandaMelilite, Carbonatite
DS1987-0044
1987
Blenkinsop, J.Bell, K., Blenkinsop, J.Neodynium and strontium isotopic compositions of East African carbonatites:implications for mantle heterogeneityGeology, Vol. 15, No. 2, pp. 99-102East AfricaCarbonatite, Geochronology
DS1987-0045
1987
Blenkinsop, J.Bell, K., Blenkinsop, J., Kwon, Tlton, SageAge and radiogenic isotopic systematics of the Border carbonatite complexOntario, canada.Canadian Journal of Earth Sciences, Vol. 24, pp. 24-30.OntarioGeochronology, deposit - Borden
DS1987-0787
1987
Blenkinsop, J.Wen, J., Bell, K., Blenkinsop, J.neodymium and Strontium isotope systematics of the Oka complex, Quebec and their bearing on the evolution of the sub-continental upper mantleContributions to Mineralogy and Petrology, Vol. 97, No. 4, pp. 433-437QuebecCarbonatite
DS1989-0102
1989
Blenkinsop, J.Bell, K., Blenkinsop, J.Neodynium and strontium isotope geochemistry of carbonatitesCarbonatites -Genesis and Evolution, Ed. K. Bell Unwin Hyman Publ, pp. 278-300East AfricaGeochemistry, Geochronology, Kimberlite
DS1993-0727
1993
Blenkinsop, T.Jackson, J., Blenkinsop, T.The Malawi Earthquake of March 10, 1989: deep faulting within the East African Rift systemTectonics, Vol. 12, No. 5, Oct. pp. 1131-39.East Africa, MalawiTectonics, Rifting
DS1995-0159
1995
Blenkinsop, T.Blenkinsop, T., et al.The north Limpopo Thrust Zone: the northern boundary of the Limpopo Belt in Zimbabwe and Botswana.Centennial Geocongress (1995) Extended abstracts, Vol. 1, p. 174-177. abstractZimbabwe, BotswanaCraton, Limpopo Thrust Zone
DS1995-1596
1995
Blenkinsop, T.Rollinson, H., Blenkinsop, T.The magmatic metamorphic and tectonic evolution of the northern Marginal Zone of the Limpopo Belt in Zimbabwe.Journal of the Geological Society of London, Vol. 152, No. 1, Jan. pp. 65-76.ZimbabweTectonics, Limpopo Belt
DS2002-1169
2002
Blenkinsop, T.Oberthur, T., Davis, D.W., Blenkinsop, T., Hohdorf, A.Precise U Pb mineral ages, Rb Sr and Sm Nd systematics for the Great Dyke, constraints on late Archean eventsPrecambrian Research, Vol. 113, No. 3-4, pp. 293-305.ZimbabweGeochronology, Craton, uranium, lead, rubidium, strontium, Limpopo Belt
DS200812-0762
2008
Blenkinsop, T.Moore, A., Blenkinsop, T., Cotterill, F.Controls on post-Gondwana alkaline volcanism in southern Africa.Earth and Planetary Science Letters, Vol. 268, 1-2, April 15, pp. 151-164.Africa, southern AfricaAlkalic
DS200912-0513
2009
Blenkinsop, T.Moore, A., Blenkinsop, T., Cotterill, F.Southern Africa topography and erosion history: plumes or plate tectonics?Terra Nova, Vol. 21, pp. 310-315.Africa, South AfricaPaleodrainage
DS202003-0352
2020
Blenkinsop, T.Moore, A.,Yudovskaya, M., Prover, A., Blenkinsop, T.Evidence for olivine deformation in kimberlites and other mantle derived magmas during crustal emplacement. LemphaneContributions to Mineralogy and Petrology, Vol. 175, 9p. PdfAfrica, Lesothoolivine

Abstract: This paper highlights published and new field and petrographic observations for late-stage (crustal level) deformation associated with the emplacement of kimberlites and other mantle-derived magmas. Thus, radial and tangential joint sets in the competent 183 Ma Karoo basalt wall rocks to the 5 ha. Lemphane kimberlite blow in northern Lesotho have been ascribed to stresses linked to eruption of the kimberlite magma. Further examples of emplacement-related stresses in kimberlites are brittle fractures and close-spaced parallel shears which disrupt olivine macrocrysts. In each of these examples, there is no evidence of post-kimberlite regional tectonism which might explain these features, indicating that they reflect auto-deformation in the kimberlite during or immediately post-emplacement. On a microscopic scale, these inferred late-stage stresses are reflected by fractures and domains of undulose extinction which traverse core and margins of some euhedral and anhedral olivines in kimberlites and olivine melilitites. Undulose extinction and kink bands have also been documented in olivines in cumulates from layered igneous intrusions. Our observations thus indicate that these deformation features can form at shallow levels (crustal pressures), which is supported by experimental evidence. Undulose extinction and kink bands have previously been presented as conclusive evidence for a mantle provenance of the olivines—i.e. that they are xenocrysts. The observation that these deformation textures can form in both mantle and crustal environments implies that they do not provide reliable constraints on the provenance of the olivines. An understanding of the processes responsible for crustal deformation of kimberlites could potentially refine our understanding of kimberlite emplacement processes.
DS1994-1254
1994
Blenkinsop, T.G.Munyanyiwa, H., Blenkinsop, T.G.Pan-African stuctures and metamorphism in the Makuti Group, north-westZimbabweJournal of African Earth Sciences, Vol. 19, No. 3, Oct. pp. 185-189ZimbabweTectonics, Structure
DS1995-0160
1995
Blenkinsop, T.G.Blenkinsop, T.G., Tromp, P.L.Sub-Saharan economic geologyBalkema Publishing, Geological Society Zimbabwe, Spec. Publishing No. 3, 320pSouthern Africa, Zimbabwe, Botswana, TanzaniaUltramafics, geophysics, diamonds, gold, Table of contents
DS1995-0524
1995
Blenkinsop, T.G.Fedo, C.M., Eriksson, K.A., Blenkinsop, T.G.Geologic history of the Archean Buhwa greenstone belt and surrounding gneiss terrane, evolution Limpopo beltCanadian Journal of Earth Sciences, Vol. 32, No. 11, Nov. pp. 1977-1990ZimbabweGreenstone belt, Archean, Limpopo Belt
DS1995-0906
1995
Blenkinsop, T.G.Kamber, B.S., Blenkinsop, T.G., Villa, I.M., Dahl, P.S.Proterozoic transpressive deformation in the northern marginal zone, Limpopo Belt, ZimbabweJournal of Geology, Vol. 103, No. 5, Sept. pp. 493-508ZimbabweTectonics,, Limpopo Belt
DS1999-0225
1999
Blenkinsop, T.G.Frei, R., Blenkinsop, T.G., Schonberg, R.Geochronology of the late Archean Razi and Chilimanzi suites of granites in Zimbabwe - tectonicsSouth African Journal of Geology, Vol. 102, No. 1, Jan. pp. 55-64.ZimbabweCraton, Limpopo Belt, Archean tectonics
DS2003-0551
2003
Blenkinsop, T.G.Hargrove, U.S., Hanson, R.E., Martin, M.W., Blenkinsop, T.G., Bowring, S.A.Tectonic evolution of the Zambesi orogenic belt: geochronological, structural andPrecambrian Research, Vol. 123, 2-4, pp. 159-186.ZimbabweBlank
DS200412-0790
2003
Blenkinsop, T.G.Hargrove, U.S., Hanson, R.E., Martin, M.W., Blenkinsop, T.G., Bowring, S.A., Walker, N., Munyanyiwa, H.Tectonic evolution of the Zambesi orogenic belt: geochronological, structural and petrological constraints from northern ZimbabwPrecambrian Research, Vol. 123, 2-4, pp. 159-186.Africa, ZimbabweTectonics
DS200612-0527
2006
Blenkinsop, T.G.Hanson, R.E., Harmer, R.E., Blenkinsop, T.G., Bullen, D.S., Dalziel, Gose, Hall, Kampunzu, Key, MukwakwamiMesoproterozoic intraplate magmatism in the Kalahari Craton: a review.Journal of African Earth Sciences, Vol. 46, 1-2, pp. 141-167.Africa, South AfricaMagmatism
DS201612-2291
2016
Blenkinsop, T.G.Cook, Y.A., Sanislav, I.V., Hammerli, J., Blenkinsop, T.G., Dirks, P.H.G.M.A primitive mantle source for the Neoarchean mafic rocks from the Tanzania Craton.Geoscience Frontiers, Vol. 7, pp. 911-926.Africa, TanzaniaMantle

Abstract: Mafic rocks comprising tholeiitic pillow basalt, dolerite and minor gabbro form the basal stratigraphic unit in the ca. 2.8 to 2.6 Ga Geita Greenstone Belt situated in the NW Tanzania Craton. They outcrop mainly along the southern margin of the belt, and are at least 50 million years older than the supracrustal assemblages against which they have been juxtaposed. Geochemical analyses indicate that parts of the assemblage approach high Mg-tholeiite (more than 8 wt.% MgO). This suite of samples has a restricted compositional range suggesting derivation from a chemically homogenous reservoir. Trace element modeling suggests that the mafic rocks were derived by partial melting within the spinel peridotite field from a source rock with a primitive mantle composition. That is, trace elements maintain primitive mantle ratios (Zr/Hf = 32-35, Ti/Zr = 107-147), producing flat REE and HFSE profiles [(La/Yb)pm = 0.9-1.3], with abundances of 3-10 times primitive mantle and with minor negative anomalies of Nb [(Nb/La)pm = 0.6-0.8] and Th [(Th/La)pm = 0.6-0.9]. Initial isotope compositions (?Nd) range from 1.6 to 2.9 at 2.8 Ga and plot below the depleted mantle line suggesting derivation from a more enriched source compared to present day MORB mantle. The trace element composition and Nd isotopic ratios are similar to the mafic rocks outcropping ?50 km south. The mafic rocks outcropping in the Geita area were erupted through oceanic crust over a short time period, between ?2830 and ?2820 Ma; are compositionally homogenous, contain little to no associated terrigenous sediments, and their trace element composition and short emplacement time resemble oceanic plateau basalts. They have been interpreted to be derived from a plume head with a primitive mantle composition.
DS201804-0733
2017
Blenkinsop, T.G.Sanislav, I.V., Blenkinsop, T.G., Dirks, P.H.G.M.Archean crustal growth through successive partial melting events in an oceanic plateau like setting in the Tanzanian craton.Terra Nova, pp. 1-10.Africa, Tanzaniacraton - geochronology

Abstract: The detrital zircon population in quartzitic conglomerates from the northern Tanzania Craton yield ages between 2640 Ma and 2790 Ma which includes most of the igneous history from this part of the craton. The igneous evolution is characterised by mafic volcanism with an oceanic plateau?like geochemical signature at ~2800 Ma followed by diorite and tonalite-trondhjemite-granodiorite dominated magmatism between 2790 and 2700 Ma, which transitioned into more evolved high?K magmatism between 2700 and 2620 Ma. The ?Hf values of the detrital zircons range from +2.4 to ?1.4 and change with time from radiogenic Hf pre?2700 Ma (98% positive ?Hf) to unradiogenic Hf post?2700 Ma (41% positive ?Hf). The petrological progression from mafic to felsic crust is reflected in the detrital age distribution and Hf isotopes and is consistent with juvenile mafic crust slowly maturing into more evolved felsic crust through a series of successive partial melting events in an oceanic?plateau?like environment.
DS2002-1082
2002
Blenkisnop, T.Moore, A., Blenkisnop, T.The role of mantle plumes in the development of continental scale drainage patterns: the southern African example revisited.South African Journal of Geology, Vol. 105, No. 4, pp. 353-60.South AfricaPlumes - geomorphology
DS201012-0036
2010
Bleoch, A.L.Bangert, U., Barnes, R., Gass, M.H., Bleoch, A.L., Godfrey, I.S.Vacancy clusters, dislocations and brown coloration in diamond.Journal of Physics Condensed Matter, Vol. 21, 36, pp. 364208-213..TechnologyDiamond crystallography
DS202009-1673
2020
Blereau, E.Volante, S., Pouteau, A., Collins, W.J., Blereau, E., Li, Z-X., Smit, M., Evans, N.J., Nordsvan, A.R., Spencer, C.J., McDonald, B.J., Li, J., Gunter, C.Multiple P-T-d-t paths reveal the evolution of the final Nuna assembly in northeast Australia. Georgetown InlierJournal of Metamorphic Geology, Vol. 38, pp. 593-627.Australiageochronology

Abstract: The final assembly of the Mesoproterozoic supercontinent Nuna was marked by the collision of Laurentia and Australia at 1.60 Ga, which is recorded in the Georgetown Inlier of NE Australia. Here, we decipher the metamorphic evolution of this final Nuna collisional event using petrostructural analysis, major and trace element compositions of key minerals, thermodynamic modelling, and multi?method geochronology. The Georgetown Inlier is characterised by deformed and metamorphosed 1.70-1.62 Ga sedimentary and mafic rocks, which were intruded by c. 1.56 Ga old S?type granites. Garnet Lu-Hf and monazite U-Pb isotopic analyses distinguish two major metamorphic events (M1 at c. 1.60 Ga and M2 at c. 1.55 Ga), which allows at least two composite fabrics to be identified at the regional scale—c. 1.60 Ga S1 (consisting in fabrics S1a and S1b) and c. 1.55 Ga S2 (including fabrics S2a and S2b). Also, three tectono?metamorphic domains are distinguished: (a) the western domain, with S1 defined by low?P (LP) greenschist facies assemblages; (b) the central domain, where S1 fabric is preserved as medium?P (MP) amphibolite facies relicts, and locally as inclusion trails in garnet wrapped by the regionally dominant low?P amphibolite facies S2 fabric; and (c) the eastern domain dominated by upper amphibolite to granulite facies S2 foliation. In the central domain, 1.60 Ga MP-medium?T (MT) metamorphism (M1) developed within the staurolite-garnet stability field, with conditions ranging from 530-550°C at 6-7 kbar (garnet cores) to 620-650°C at 8-9 kbar (garnet rims), and it is associated with S1 fabric. The onset of 1.55 Ga LP-high?T (HT) metamorphism (M2) is marked by replacement of staurolite by andalusite (M2a/D2a), which was subsequently pseudomorphed by sillimanite (M2b/D2b) where granite and migmatite are abundant. P-T conditions ranged from 600 to 680°C and 4-6 kbar for the M2b sillimanite stage. 1.60 Ga garnet relicts within the S2 foliation highlight the progressive obliteration of the S1 fabric by regional S2 in the central zone during peak M2 metamorphism. In the eastern migmatitic complex, partial melting of paragneiss and amphibolite occurred syn? to post? S2, at 730-770°C and 6-8 kbar, and at 750-790°C and 6 kbar, respectively. The pressure-temperature-deformation-time paths reconstructed for the Georgetown Inlier suggest a c. 1.60 Ga M1/D1 event recorded under greenschist facies conditions in the western domain and under medium?P and medium?T conditions in the central domain. This event was followed by the regional 1.56-1.54 Ga low?P and high?T phase (M2/D2), extensively recorded in the central and eastern domains. Decompression between these two metamorphic events is ascribed to an episode of exhumation. The two?stage evolution supports the previous hypothesis that the Georgetown Inlier preserves continental collisional and subsequent thermal perturbation associated with granite emplacement.
DS201312-0083
2013
Blessington, M.Blessington, M., Kettler, R., Verplanck, P., Farmer, G.L.Niobium mineralization in a magnetite rich carbonatite, Elk Creek Nebraska, USA.Goldschmidt 2013, AbstractUnited States, NebraskaCarbonatite
DS201412-0947
2014
Blessington, M.J.Verplank, P.L., Kettler, R.M., Blessington, M.J., Lowers, H.A., Koenig, A.E., Farmer, G.L.Rare earth element and niobium enrichments in the Elk Creek carbonatite, USA.30th. International Conference on Ore Potential of alkaline, kimberlite and carbonatite magmatism. Sept. 29-, http://alkaline2014.comUnited States, NebraskaCarbonatite
DS1996-0139
1996
Blevin, P.L.Blevin, P.L., Chappell, B.W.Controls on the distribution and character of the intrusive metallogenic provinces of eastern AustraliaGeological Society of Australia 13th. held Feb, No. 41, abstracts p. 42AustraliaMetallogeny, Granites
DS1996-0619
1996
Blewett, R.Hazell, M., Blewett, R., Bailey, J.If only Newton had had AGSO's FieldPadAgso Research Newsletter, No. 25, Nov. pp. 3-5GlobalComputer, Digitized version of field notebook
DS2002-0168
2002
Blewett, R.S.Blewett, R.S.Archean tectonic processes: a case for horizontal shortening North Pilbara granite greenstone terranePrecambrian Research, Vol. 113, No. 1-2, Jan. pp. 87-120.AustraliaTectonics - Pilbara - not specific to diamonds
DS200512-0350
2004
Blewett, R.S.Goleby, B.R., Blewett, R.S., Korsch, R.J., Champion, D.C., Cassidy, K.F., Jones, L.E., Groenewald, P.B., Henson, P.Deep seismic reflection profiling in the Archean northeastern Yilgarn Craton: implications for crustal architecture and mineral potential.Tectonophysics, Vol. 388, 1-4, pp. 119-133.AustraliaGeophysics - seismics, not specific to diamonds
DS1991-0126
1991
Bley de Brito Neves, B.Bley de Brito Neves , B., Cordani, U.G.Tectonic evolution of South America during the Late ProterozoicPrecambrian Research, Vol. 53, pp. 23-40BrazilTectonics, Proterozoic
DS2002-0169
2002
Bley de Brito Neves, B.Bley de Brito Neves, B., Van Schmus, W.R., Fetter, A.Northwestern Africa North eastern Brasil. Major tectonic links and correlation problems.Journal of African Earth Sciences, Vol.34, No.3-4,April-May pp. 275-8.Brazil, AfricaTectonics
DS201312-0084
2013
Bley de Brito Neves, B.Bley de Brito Neves, B., Fuck, R.A.The Neoproterozoic evolution of the basement of the South Americam platform.Journal South American Earth Sciences, Vol. 47, pp. 72-89.South AmericaCraton - Amazon
DS1999-0076
1999
Blichert Toft, J.Blichert Toft, J., Albarede, F., Kornprobst, J.Lutetium - Hafnium isotope systematics of garnet pyroxenites from Beni Bousera: implications for basalt origin.Science, Vol. 285, No. 5406, Feb. 26, pp. 1303-5.MoroccoGeochronology, Deposit - Beni Bousera
DS2001-0174
2001
Blichert Toft, J.Chauvel, C., Blichert Toft, J.A hafnium isotope and trace element perspective on melting of the depletedmantle.Earth and Planetary Science Letters, Vol. 190, No. 3-4, pp. 137-51.MantleMelting
DS2003-0446
2003
Blichert Toft, J.Gasperini, D., Blichert Toft, J., Bosch, D., Del Moro, A., Macera, P., Albaraede, F.Upwelling of deep mantle material through a plate window: evidence from theJournal of Geophysical Research, Vol. 107, 12, Dec. 6, pp. DO1 10.1029/2001JB000418MantleGeophysics - seismics, Tectonics
DS200412-0614
2003
Blichert Toft, J.Gasperini, D., Blichert Toft, J., Bosch, D., Del Moro, A., Macera, P., Albaraede, F.Upwelling of deep mantle material through a plate window: evidence from the geochemistry of Italian basaltic volcanics.Journal of Geophysical Research, Vol. 107, 12, Dec. 6, pp. DO1 10.1029/2001 JB000418MantleGeophysics - seismics Tectonics
DS200512-0396
2004
Blichert Toft, J.Hanan, B.B., Blichert Toft, J., Pyle, D.G., Christie, D.M.Contrasting origins of the upper mantle revealed by hafnium and lead isotopes from southeast Indian Ridge ( corrigendum).Nature, No. 7017, Dec. 2, pp. 653-654.Mantle, IndiaGeochronology
DS200512-0397
2004
Blichert Toft, J.Hanan, N.B., Blichert Toft, J., Pyle, D.G., Christie, D.M.Contrasting origins of the upper mantle revealed by hafnium and lead isotopes from the southeast Indian Ridge.Nature, No. 7613, Nov. 4, pp. 91-93.Indian RidgeGeochronology
DS200512-0464
2005
Blichert Toft, J.Ionov, D.A.,Blichert Toft, J., Weiss, D.Hf isotope compositions and HREE variations in off craton garnet and spinel peridotite xenoliths from central Asia.Geochimica et Cosmochimica Acta, Vol. 69, 9, pp. 2399-2418.AsiaGeochemistry
DS200612-0486
2006
Blichert Toft, J.Graham, D.W., Blichert Toft, J., Russo, C.J., Rubin, K.H., Albarede, F.Cryptic striations in the upper mantle revealed by hafnium isotopes in southeast Indian Ridge basalts.Nature, Vol. 440, 7081, pp. 199-202.Asia, IndiaGeochronology, tectonics
DS200612-1209
2006
Blichert Toft, V.J.Salters, V.J., Blichert Toft, V.J., Fekiacova, J., Sachikocher, A., Bizimis, M.Isotope and trace element evidence for depleted lithosphere in the source of enriched Kolau basalts.Contributions to Mineralogy and Petrology, Vol. 151, 3, pp. 297-312.RussiaGeochronology
DS2001-0916
2001
BlichertoftPhilippot, P., Blichertoft, Perchuk, Costa, GerasimovLutetium(Lu)- Hafnium(Hf) and Argon- Argon chronology supports extreme rate of subduction zone metamorphism deduced geospeedometryTectonophysics, Vol. 342, No. 2, pp. 23-38.MantleGeochronology, Argon, Lutetium, Hafnium, Subduction
DS1994-0170
1994
Blichert-ToftBlichert-Toft, Luais, B.The life times of ancient chemical heterogeneities in mantle and their implications evolution of convection.Mineralogical Magazine, Vol. 58A, pp. 99-100. AbstractMantleGeochemistry, Geochronology
DS1998-1540
1998
Blichert-ToftVervoort, J., Patchett, P.J., Blichert-Toft, AlbaredeHafnium neodymium isotopic covariance in the crust and mantle and constraints on the evolution of the depleted mantle.Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1595-6.GreenlandGeochronology
DS2000-0215
2000
Blichert-ToftDe Sigoyer, J., Chavagnac, Blichert-Toft, Villa, LuaisDating the Indian continental subduction and collisional thickening in northwest Himalaya: eclogitesGeology, Vol. 28, No. 6, June pp. 487-90.IndiaSubduction - multichronology, Geochronology - Tso Morari eclogites
DS1996-0140
1996
Blichert-Toft, J.Blichert-Toft, J., Arndt, N.T., Ludden, J.N.Precambrian alkaline magmatismLithos, Vol. 37, No. 2/3, April pp. 97-112GlobalMagmatism, Alkaline rocks
DS1997-0104
1997
Blichert-Toft, J.Blichert-Toft, J., Albarede, F.The Lutetium - Hafnium isotope geochemistry of chondrite and the evolution of mantle crust systemEarth and Planetary Science Letters, Vol. 148, No. 1-2, Apr. 1, pp. 243-258MantleChondite, Geochemistry
DS1999-0770
1999
Blichert-Toft, J.Vervoort, J.D., Blichert-Toft, J.Evolution of the depleted mantle: Hafnium isotope evidence from juvenile rocks through time.Geochimica et Cosmochimica Acta, Vol. 63, No. 3-4, Feb. 1, pp. 533-56.MantleGeochronology
DS2000-0865
2000
Blichert-Toft, J.Scherer, E.E., Cameron, K.L., Blichert-Toft, J.Lutetium - Hafnium garnet geochronology: closure temperature relative to the Sm neodymium system - effects trace inclusionsGeochimica et Cosmochimica Acta, Vol. 64, No. 19, Oct. 1, pp. 3413-32.GlobalGarnet - geochronology
DS200412-0123
2004
Blichert-Toft, J.Bedini, R.M., Blichert-Toft, J., Boyet, M., Albarede, F.Isotopic constraints on the cooling of the continental lithosphere.Earth and Planetary Science Letters, Vol. 223, 1-2, June, 30, pp. 99-111.Africa, South AfricaGarnet peridotite xenoliths, radiometric ages, geotherm
DS200412-0164
2004
Blichert-Toft, J.Blichert-Toft, J., Arndt, N.T., Gruau, G.Hf isotopic measurements on Barberton komatiites: effects of incomplete sample dissolution and importance for primary and secondChemical Geology, Vol. 207, 3-4, July 16, pp. 261-275.Africa, South AfricaGeochronology - not specific to diamonds
DS200412-0777
2004
Blichert-Toft, J.Hanan, B., Blichert-Toft, J., Pyle, D., Christie, D.Contrasting origins of the upper mantle MORB source revealed by Hf and Pb isotopes from the Australian Antarctic discordance.Geochimica et Cosmochimica Acta, 13th Goldschmidt Conference held Copenhagen Denmark, Vol. 68, 11 Supp. July, ABSTRACT p.A553.India, Australia, AntarcticaSubduction
DS200512-1110
2005
Blichert-Toft, J.Upton, B.G.J., Ramo, O.T., Heaman, L.M., Blichert-Toft, J., Kalsbeek, F., Barry, T.L., Jepsen, H.F.The Mesoproterozoic Zig-Zag Dal basalts and associated intrusions of eastern North Greenland: mantle plume lithosphere interaction.Contributions to Mineralogy and Petrology, Vol. 149, 1, pp. 40-56.Europe, GreenlandTectonics
DS200612-0012
2006
Blichert-Toft, J.Albarede, F., Blichert-Toft, J.Reading old mantle tea leaves: the survival of plate material in the source of MORB and OIB.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 7, abstract only.MantleGeochronology
DS200612-0540
2005
Blichert-Toft, J.Harrison, T.M., Blichert-Toft, J., Muller, W., Albarede, F., Holden, P., Mojzsis, S.J.Heterogeneous Hadean hafnium: evidence of continental crust 4.4 to 4.5 Ga.Science, Vol. 310, 5736 Dec. 23, pp. 1947-1949.MantleGeochronology
DS200612-0541
2006
Blichert-Toft, J.Harrison, T.M., McCulloch, M.T., Blichert-Toft, J., Albarede, F., Holden, P., Mojzsis, S.J.Further Hf isotope evidence for Hadean continental crust.Geochimica et Cosmochimica Acta, Vol. 70, 18, 1, p. 14, abstract only.MantleGeochronology
DS200712-0083
2007
Blichert-Toft, J.Blichert-Toft, J., Harrison, T.M., Albarede, F.The age of the earliest continental crust and onset of plate tectonics.Plates, Plumes, and Paradigms, 1p. abstract p. A98.AustraliaGeochronology
DS200712-0339
2007
Blichert-Toft, J.Gaffney, A.M., Blichert-Toft, J., Nelson, B.K., Bizzarro, M., Rosing, M., Albarec, F.Constraints on source forming processes of West Greenland kimberlites inferred from Hf Nd isotope systematics.Geochimica et Cosmochimica Acta, Vol. 71, 11, June 1, pp. 2820-2836.Europe, GreenlandGeochronology
DS200712-0340
2007
Blichert-Toft, J.Gaffney, A.M., Blichert-Toft, J., Nelson, B.K., Bizzarro, M., Rosing, M., Albarede, F.Constraints on source forming processes of West Greenland kimberlites inferred from Hf Nd isotope systematics.Geochimica et Cosmochimica Acta, Vol. 71, 11, pp. 2820-2836.Europe, GreenlandDiamond genesis
DS200712-0408
2007
Blichert-Toft, J.Hana, B.B., Blichert-Toft, J., Kingsley, R.H., Schilling, J-G.Source origin of the ultrapotassic lavas from the Leucite Hills, Wyoming: Hf isotope constraints.Plates, Plumes, and Paradigms, 1p. abstract p. A375.United States, Wyoming, Colorado PlateauLamproite
DS200712-0496
2007
Blichert-Toft, J.Jourdan,F., Bertrand, H., Scharer, U., Blichert-Toft, J., Feraud, G., Kampunzu, A.B.Major and trace element and Sr Nd, Hf, and Pb isotope compositions of the Karoo large igneous province, Botswana and Zimbabwe: lithosphere vs mantle plume...Journal of Petrology, Vol. 48, 6, pp. 1043-1078.Africa, Botswana, ZimbabweGeochemistry, geochronology
DS200712-0721
2007
Blichert-Toft, J.Meyzen, C.M., Blichert-Toft, J., Ludden, J.N., Humler, E., Mevel, C., Albaraede, F.Isotopic portrayal of the Earth's upper mantle flow field.Nature, Vol. 447, June 28, pp.1069-1074.MantleGeochronology - subduction
DS200712-0722
2007
Blichert-Toft, J.Meyzen, C.M., Blichert-Toft, J., Ludden, J.N., Humler, E., Mevel, C., Albaraede, F.Isotopic portrayal of the Earth's upper mantle flow field.Nature, Vol. 447, June 28, pp.1069-1074.MantleGeochronology - subduction
DS200812-0118
2008
Blichert-Toft, J.Blichert-Toft, J., Albarede, F.Hafnium isotopes in Jack Hills zircons and the formation of the Hafnium crust.Earth and Planetary Science Letters, Vol. 265, 3-4, Jan. 30, pp. 686-702.AustraliaGeochronology
DS200812-0586
2008
Blichert-Toft, J.Konter, J.C., Hanan, B.B., Blichert-Toft, J., Koppers, A.A.P., Plank, T., Staudigel, H.One hundred million years of mantle geochemical history suggest the retiring of mantle plumes is premature.Earth and Planetary Science Letters, Vol. 275, 3-4, pp. 285-295.MantleMagmatism
DS201012-0058
2010
Blichert-Toft, J.Blichert-Toft, J., Puchtel, I.S.Depleted mantle sources through time: evidence from Lu Hf and Sm Nd isotope systematics of Archean komatiites.Earth and Planetary Science Letters, Vol. 297, 3-4, pp. 598-606.MantleGeochronology
DS201112-0011
2011
Blichert-Toft, J.Albaraede, F., Ballhaus, C., Lee, C.T.A., Yin, Q-Z., Blichert-Toft, J.The great volatile delivery to Earth.Goldschmidt Conference 2011, abstract p.420.MantleGeochronology - Pb
DS201112-0088
2011
Blichert-Toft, J.Bianchini,G., Bryce, J.G., Blichert-Toft, J., Beccaluca, L., Natali, C.Pb Hf Nd isotopic decoupling in peridotite xenoliths from Mega ( Ethiopia): insights into multistage evolution of the East African lithosphere.Goldschmidt Conference 2011, abstract p.528.Africa, EthiopiaTanzanian Craton
DS201112-0854
2011
Blichert-Toft, J.Reid, M.R., Bouchet, R.A., Blichert-Toft, J.Melting conditions associated with the Colorado Plateau, USA.Goldschmidt Conference 2011, abstract p.1704.United States, Colorado PlateauThermobarometry
DS201412-0310
2014
Blichert-Toft, J.Graham, D.W., Hanan, B.B., Hemond, C., Blichert-Toft, J., Albarede, F.Helium isotopic textures in Earth's upper mantle.Geochemistry, Geophysics, Geosystems: G3, Vol. 15, no. 5, pp. 2048-2074.MantleHelium
DS201505-0243
2015
Blichert-Toft, J.Katzir, Y., Anenburg, M., Kaminchik, J., Segev, A., Blichert-Toft, J., Spicuzza, M.J., Valley, J.W.Garnet pyroxenites as markers of recurring extension and magmatism at the rifted margins of the Levant basin.Israel Geological Society, Abstracts 1p.Europe, Israel, Mt. CarmelPyroxenite
DS201612-2332
2016
Blichert-Toft, J.Rudzitis, S., Reid, M.R., Blichert-Toft, J.On edge melting under the Colorado Plateau margin.Geochemistry, Geophysics, Geosystems: G3, Vol. 17, 10, 1002/ 2016GC006349.United States, Colorado PlateauMelting

Abstract: Asthenosphere beneath the relatively thin lithosphere of the Basin and Range province appears to be juxtaposed in step-like fashion against the Colorado Plateau's thick lithospheric keel. Primary to near-primary basalts are found above this edge, in the San Francisco-Morman Mountain volcanic fields, north central Arizona, western USA. We show that at least two distinct peridotite-dominated mantle end-members contributed to the origin of the basalts. One has paired Nd and Hf isotopic characteristics that cluster near the mantle array and trace element patterns as expected for melts generated in the asthenosphere, possibly in the presence of garnet. The second has isotopic compositions displaced above the ?Hf - ?Nd mantle array which, together with its particular trace element characteristics, indicate contributions from hydrogenous sediments and/or melt (carbonatite or silicate)-related metasomatism. Melt equilibration temperatures obtained from Si- and Mg-thermobarometry are mostly 1340-1425°C and account for the effects of water (assumed to be 2 wt.%) and estimated CO2 (variable). Melt equilibration depths cluster at the inferred location of the lithosphere-asthenosphere boundary at ?70-75 km beneath the southwestern margin of the Colorado Plateau but scatter to somewhat greater values (?100 km). Melt generation may have initiated in or below the garnet-spinel facies transition zone by edge-driven convection and continued as mantle and/or melts upwelled, assimilating and sometimes equilibrating with shallower contaminated mantle, until melts were finally extracted.
DS201905-1018
2019
Blichert-Toft, J.Bohm, C.O., Hartlaub, R.P., Heaman, L.M., Cates, N., Guitreau, M., Bourdon, B., Roth, A.S.G., Mojzsis, S.J., Blichert-Toft, J.The Assean Lake Complex: ancient crust at the northwestern margin of the Superior Craton, Manitoba, Canada.Earths Oldest Rocks, researchgate.com Chapter 28, 20p. Pdf availableCanada, Manitobacraton

Abstract: This chapter describes the Assean Lake Complex (ALC) at ancient crust at the Northwestern margin of the Superior Craton, Manitoba, and Canada. An initial tectonic model for the Assean Lake area indicated that a regionally extensive high-strain zone running through the lake marks the suture between Archean high-grade crustal terranes of the Superior Craton to the southeast and Paleoproterozoic rocks of the Trans-Hudson Orogen to the northwest. Detailed geologic remapping combined with isotopic and geochemical studies led to a re-interpretation of the crust immediately north of the Assean Lake high-strain zone as Mesoarchean. The study area straddles the boundary between the Archean Superior Craton and the ca.1.90-1.84 Ga arc and marginal basin rocks of the Trans-Hudson Orogen, which represent the remains of ca. 1.83-1.76 Ga ocean closure and orogeny. It is indicated that the gneisses of the Split Lake Block consist primarily of meta-igneous protoliths of gabbroic to granitic composition. Tonalite and granodiorite are the most volumetrically dominant, but an anorthosite dome is also present in the northeast. Mapping, isotopic, and age data combined with high-resolution aero-magnetic data indicate that the Mesoarchean ALC is a crustal slice up to 10 km wide, and has a strike length of at least 50 km.
DS202002-0167
2019
Blichert-Toft, J.Bohm, C.O., Hartlaub, R.P., Heaman, L.M., Cates, N., Guitreau, M., Bourdon, B., Roth, A.S.G., Mojzsis, S.J., Blichert-Toft, J.The Assean Lake Complex: ancient crust at the northwestern margin of the Superior craton, Manitoba, Canada. ( not specific to diamonds)Earth's Oldest Rocks, Chapter 28, 20p. Pdf.Canada, Manitobacraton
DS200812-0014
2008
Blichert-Tor, J.Albarede, F., Blichert-Tor, J.The Earth accredited dry and its ocean rains into the mantle.Goldschmidt Conference 2008, Abstract p.A15.MantleWater
DS1993-1442
1993
Blinchik, T.M.Shatsky, V.S., Jagoutz, E., Kozmenko, O.A., Blinchik, T.M., Sobolev, N.V.Age and genesis of eclogites from the Kokchetav massif (northernKazakhstan).Russian Geology and Geophysics, Vol. 34, No. 12, pp. 40-50.Russia, KazakhstanGeochronology, Eclogites
DS1860-0541
1887
Blink, H.Blink, H.Door Natal in Het Hart Van Zuid-afrikaAmsterdam: Brinkman., Africa, South AfricaTravelogue
DS1900-0055
1901
Blink, H.Blink, H.Het Vraagstuk der Nederlandsche Emigratie Naar Zuid AfrikaUnknown., PP. 53-72.Africa, South AfricaDiamond Occurrence
DS201312-0761
2013
Blinova, A.I.Rukhlov, A.S., Blinova, A.I., Pawlowicz, J.G.Geochemistry, mineralogy and petrology of the Eocene potassic magmatism from the Milk River area, southern Alberta and Sweet Grass Hills, northern Montana.Chemical Geology, Vol. 353, pp. 280-302.Canada, Alberta, United States, MontanaMilk River area
DS1985-0066
1985
Blinova, G.K.Blinova, G.K.Distribution of Nitrogen Centers from Kimberlites Yakutia.(russian)Geologii i Geofiziki, (Russian), No. 3, pp. 116-119RussiaRef. Fleischer United States Geological Survey (usgs) Of 88-689.mineralogical Refs. 198, Mineralogy
DS1985-0067
1985
Blinova, G.K.Blinova, G.K., Gurkina, G.A., Frolova, L.N.A Study of Polycrystalline Aggregates of Diamond With lonsdaleite Using the Methods of X-ray Radiography And infrared Spectroscopy.(russian)Mineral. Sbornik., (Russian), Vol. 39, No. 2, pp. 18-21RussiaBlank
DS1985-0324
1985
Blinova, G.K.Kaminsky, F.V., Blinova, G.K., et al.Polycrystalline Aggregates of Diamond with Lonsdalaeite From Placers in Yakutia.Mineral. Zhurn., Vol. 7, No. 1, PP. 27-36.Russia, YakutiaMineralogy
DS1987-0059
1987
Blinova, G.K.Blinova, G.K.Structural impurities as indicators of the mechanism of natural diamondgrowth.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR (Russian), Vol. 294, No. 4, pp. 868-871RussiaNatural diamond, Crystallography Morpholog
DS1988-0063
1988
Blinova, G.K.Blinova, G.K.Some peculiarities of chemical environment of naturaldiamondcrystallization.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 300, No. 4, pp. 950-952RussiaDiamond morphology
DS1988-0064
1988
Blinova, G.K.Blinova, G.K., Gurkina, G.A., Simakov, S.K.Some chemical properties of the medium from which natural diamondscrystallizeDoklady Academy of Science USSR, Earth Science Section, Vol. 301, No. 4, July-Aug, pp. 207-209RussiaDiamond morphology, Crystallography
DS1989-0125
1989
Blinova, G.K.Blinova, G.K.Distribution of structural impurities in diamonds ofdifferentgenesis.(Russian)Doklady Academy of Science USSR, Earth Science Section, Vol. 304, No. 1, Jan-Feb. pp. 156-158RussiaDiamond inclusions, Diamond genesis
DS1989-0126
1989
Blinova, G.K.Blinova, G.K.Distribution of structural impurities in diamonds of different originsDoklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 304, No. 1, pp. 184-186RussiaDiamond morphology
DS1989-0127
1989
Blinova, G.K.Blinova, G.K., Verzhak, V.V., Zakharchenko, O.D., Medvedeva, M.S.Impurity centers in diamonds from two kimberlite pipes in the Arkhangel diamond provinceSoviet Geology and Geophysics, Vol. 30, No. 8, pp. 122-125RussiaDiamond inclusions, Arkhangel
DS1990-0211
1990
Blinova, G.K.Blinova, G.K.Distribution of structural impurities in diamonds of different originDoklady Academy of Science USSR, Earth Science Section, Vol. 304 No. 1-6, pp. 156-158RussiaDiamond morphology, Impurities
DS1991-0127
1991
Blinova, G.K.Blinova, G.K., Ilupin, I.P., Frolova, L.N.Impurity centers in diamonds from two regions of Siberian PlatformSoviet Geology and Geophysics, Vol. 32, No. 8, pp. 76-78RussiaDiamond morphology, Nitrogen
DS1991-1666
1991
Blisniuk, P.Strecker, M.R., Blisniuk, P., Bosworth, W.The kinematic evolution of the central Kenya rift in the light of the East African stress field historyGeological Society of America Annual Meeting Abstract Volume, Vol. 23, No. 5, San Diego, p. A 134KenyaTectonics, Rifting
DS1990-1424
1990
Blisniuk, P.M.Strecker, M.R., Blisniuk, P.M.Rotation of extension direction in the central Kenya rift (Lat 1 20 s to 0Terra, Abstracts of Crustal Dynamics: Pathways and Records held Bochum FRG, Vol. 2, December p. 20KenyaTectonics, Kenya rift
DS1990-1425
1990
Blisniuk, P.M.Strecker, M.R., Blisniuk, P.M., Eisbacher, G.H.Rotation of extension direction in the central Kenya rift (Lat 120 s to 020 n)Geology, Vol. 18, No. 4, April pp. 299-302KenyaTectonics, Rifting
DS1982-0103
1982
Bliss, J.D.Bliss, J.D.Stratigraphic, Structural and Tectonic References Index For the Navajo Indian Reservation Arizona, New Mexico and Utah.United States Geological Survey (USGS) OPEN FILE., No. 82-731, 48P.GlobalKimberlite, Tectonic, Colorado Plateau Rocky Mountains
DS1990-0212
1990
Bliss, J.D.Bliss, J.D., McKelvey, G.E., Allen, M.S.Application of grade and tonnage deposit models: the search for ore deposits possible amenable to small scale miningUnited States Geological Survey (USGS) Open File, No. 90-0412, 24p. $ 3.75GlobalReserves -Models -grade and tonnage, Mining applications
DS1991-1271
1991
Bliss, J.D.Orris, G.J., Bliss, J.D.Some industrial mineral deposit models: descriptive deposit modelsUnited States Geological Survey (USGS) Open File, No. 91-0011-A, 73pGlobalDeposit -models, Industrials
DS1992-0132
1992
Bliss, J.D.Bliss, J.D.Grade and tonnage and other models for diamond kimberlite pipesNonrenewable Resources, Vol. 1, No. 3, fall pp. 214-230GlobalEconomic evaluation, Grade and tonnage
DS1992-0133
1992
Bliss, J.D.Bliss, J.D.Developments in mineral deposit modelingUnited States Geological Survey (USGS) Bulletin, No. 2004, 168p. $ 9.50United StatesMineral deposit modeling, abstracts
DS1992-0134
1992
Bliss, J.D.Bliss, J.D., Sutphin, D.M., Mosier, D.L., Allen, M.S.Grade and tonnage and target area models of Au-Ag-Te veins associated with alkalic rocksUnited States Geological Survey (USGS) Open File, No. 92-0208, $ 2.25United StatesAlkaline rocks, Mineralization -not specific to kimberlites
DS1992-1152
1992
Bliss, J.D.Orris, G.J., Bliss, J.D.Industrial minerals deposit models: grade and tonnageUnited States Geological Survey (USGS) Open file, 92-0437, 84p. $ 13.25United StatesModels, grade and tonnage, Industrial minerals
DS1995-1597
1995
Blmkinsop, T.Rollinson, H., Blmkinsop, T.The magmatic, metamorphic and tectonic evolution of the northern Marginal Zone of the Limpopo Belt in ZimababweJournal of the Geological Society of London, Vol. 152, No. 1, Jan. pp. 65-76ZimbabweTectonics, Limpopo Belt
DS201312-0513
2013
Block, D.L.Kramers, J.D., Andreoli, M.A.G., Atanasova, M., Belyanin, G.A., Block, D.L., Franklyn, C., Harris, C., Lekgoathi, M., Montross, C.S., Ntsoane, T., Pischedda, V., Segonyane, P., Viljoen, K.S., Westraadt, J.E.Unique chemistry of a diamond bearing pebble from the Libyan desert glass strewnfield, SW Egypt: evidence for a shocked comet fragment.Earth and Planetary Science Letters, Vol.382, pp. 21-31.Africa, EgyptShock diamonds
DS1997-0662
1997
Block, J.Leckie, D.A., Kjarsgaard, B.A., Block, J., McIntyreEmplacement and reworking of Cretaceous diamond bearing crater facies kimberlite of central Saskatchewan.Geological Society of America (GSA) Bulletin., Vol. 109, No. 8, pp. 1000-20.SaskatchewanDiamond - genesis, structure, tectonics, Petrography
DS201504-0185
2015
Block, S.Block, S., Ganne, J., Baratoux, A.Z., Parra-Avila, L.A., Jessell, M., Ailleres, L., Siebenaller, L.Petrological and geochronological constraints on lower crust exhumation during Paleoproterozoic (Eburnean) Orogeny, NW Ghana, West African craton.Journal of Metamorphic Geology, Vol. 33, 5, pp. 463-494.Africa, GhanaGeochronology

Abstract: New petrological and geochronological data are presented on high-grade ortho- and paragneisses from northwestern Ghana, forming part of the Paleoproterozoic (2.25-2.00 Ga) West African Craton. The study area is located in the interference zone between N-S and NE--SW-trending craton-scale shear zones, formed during the Eburnean orogeny (2.15-2.00 Ga). High-grade metamorphic domains are separated from low-grade greenstone belts by high-strain zones, including early thrusts, extensional detachments and late-stage strike-slip shear zones. Paragneisses sporadically preserve high-pressure, low-temperature (HP-LT) relicts, formed at the transition between the blueschist facies and the epidote-amphibolite sub-facies (10.0-14.0 kbar, 520-600 °C), and represent a low (~15 °C km?1) apparent geothermal gradient. Migmatites record metamorphic conditions at the amphibolite-granulite facies transition. They reveal a clockwise pressure-temperature-time (P-T-t) path characterized by melting at pressures over 10.0 kbar, followed by decompression and heating to peak temperatures of 750 °C at 5.0-8.0 kbar, which fit a 30 °C km?1 apparent geotherm. A regional amphibolite facies metamorphic overprint is recorded by rocks that followed a clockwise P-T-t path, characterized by peak metamorphic conditions of 7.0-10.0 kbar at 550-680 °C, which match a 20-25 °C km?1 apparent geotherm. These P-T conditions were reached after prograde burial and heating for some rock units, and after decompression and heating for others. The timing of anatexis and of the amphibolite facies metamorphic overprint is constrained by in-situ U-Pb dating of monazite crystallization at 2138 ± 7 and 2130 ± 7 Ma respectively. The new data set challenges the interpretation that metamorphic breaks in the West African Craton are due to diachronous Birimian ‘basins’ overlying a gneissic basement. It suggests that the lower crust was exhumed along reverse, normal and transcurrent shear zones and juxtaposed against shallow crustal slices during the Eburnean orogeny. The craton in NW Ghana is made of distinct fragments with contrasting tectono-metamorphic histories. The range of metamorphic conditions and the sharp lateral metamorphic gradients are inconsistent with ‘hot orogeny’ models proposed for many Precambrian provinces. These findings shed new light on the geodynamic setting of craton assembly and stabilization in the Paleoproterozoic. It is suggested that the metamorphic record of the West African Craton is characteristic of Paleoproterozoic plate tectonics and illustrates a transition between Archean and Phanerozoic orogens.
DS1989-1513
1989
Blockley, J.G.Trendall, A.F., Blockley, J.G., Middleton, M.F., Myers, J.S.The tectonic evolution of western Australia and its control ofmineralizationPreprint from IGC Washington July 1989, 3pAustraliaBrief mention diamonds, Tectonics
DS1993-0868
1993
BlodgetKusky, T.M., Lowman, Masuoka, BlodgetAnalysis of Seasat L Band Radar imagery of the West Bay Indin Lake faultsystemJournal of Geology, Vol. 101, pp. 623-32.Northwest TerritoriesRemote Sensing, Slave Province
DS1993-0869
1993
Blodget, H.W.Kusky, T.M., Lowman, P.D.Jr., Masuoka, P., Blodget, H.W.Analysis of Seasat L-Band radar imagery of the West Bay-Indin Lake FaultSystem, Northwest TerritoriesJournal of Geology, Vol. 101, No. 5, September pp. 623-632Northwest TerritoriesRemote Sensing
DS200512-0751
2004
BlodgettMoses, T.M., Johnson, M.L., Green, B., Blodgett, Cino, Geurts, Gilbertson, hemphill, King, Kornylak, ReinitzA foundation for grading the overall cut quality of round brilliant cut diamonds.Gems & Gemology, Vol. 40, 3, Fall, pp. 202-228.Diamond cutting
DS1991-0509
1991
Blodgett, C.F.Franklin, S.E., Peddle, D.R., Wilson, B.A., Blodgett, C.F.Pixel sampling of remotely sensed digital imageryComputers and Geosciences, Vol. 17, No. 6, pp. 759-776GlobalComputers, Remote sensing
DS201112-0093
2011
Blodgett, T.Blodgett, T.Application of discriminant analysis in gemology: country of origin separation in colored stones and distingishing HPHT treated diamonds.Gems & Gemology, Summer issue ... abstracts from GIA p. 145.TechnologyHPHT treatment
DS201112-0094
2011
Blodgett, T.Blodgett, T.Length to width ratios among fancy shape diamonds.GIA International Symposium 2011, Gems & Gemology summer issue Poster session abs. p.129.TechnologyDiamond crystallography
DS201312-0307
2011
Blodgett, T.Geurts, R.H., Reinitz, I.M., Blodgett, T., Gilbertson, A.M.GIA's symmetry grading boundaries for round brilliant cut diamonds.Gems & Gemology, Vol. 47, winter pp. 286-295.TechnologyDiamond cutting
DS201412-0037
2013
Bloem, A.Barnett, W., Jelsma, H., Watkeys, M., Freeman, L., Bloem, A.How structure and stress influence kimberlite emplacement.Proceedings of the 10th. International Kimberlite Conference, Vol. 2, pp. 51-66.Africa, South AfricaKimberley District - dyke modeling
DS1997-0105
1997
Bloem, E.J.M.Bloem, E.J.M., Dalstra, H.J., Groves, D.I.Granitoid diapirism during protracted tectonism in an Archean granitoid greenstone belt, Yilgarn BlockPrecambrian Research, Vol. 85, No. 3-4, Dec. 1, pp. 147-AustraliaTectonics, Yilgarn greenstone belt
DS1860-0136
1871
Bloemhof CommissionBloemhof CommissionEvidence Taken at Bloemhof Before the Commission Vaal RiverUnknown, APRIL 4TH.Africa, South Africa, Griqualand WestHistory, Politics
DS201808-1726
2018
Blom, E.Blom, E.Presentation by World Federation of Diamond Bourses President Ernie Blom.SAIMM Diamonds - source to use 2018 Conference 'thriving in changing times'. June 11-13., 20 ppts.Globaldiamond bourse
DS1989-1456
1989
Blom, M.P.Stettler, E.H., De Beer, J.H., Blom, M.P.Crustal domains in the Northern Kaapvaal craton as defined by magneticlineamentsPrecambrian Research, Vol. 45, pp. 263-276South AfricaCraton, Geophysics -magnetics
DS1991-0128
1991
Blonda, P.N.Blonda, P.N., Pasquariello, G., Losito, S., Mori, A., PosaAn experiment for the interpretation of multitemporal remotely sensed images based on a fuzzy logic approachInternational Journal of Remote Sensing, Vol. 12, No. 3, March pp. 463-476GlobalRemote sensing, Fuzzy logic
DS201710-2222
2017
Blondes, M.S.Craddock, W.H., Blondes, M.S., DeVera, C.A., Hunt, A.G.Mantle and crustal gases of the Colorado Plateau: geochemistry, sources, and migration pathways.Geochimica et Cosmochinica Acta, Vol. 213, pp. 346-374.United States, Coloradovolatiles

Abstract: The Colorado Plateau hosts several large accumulations of naturally occurring, non-hydrocarbon gases, including CO2, N2, and the noble gases, making it a good field location to study the fluxes of these gases within the crust and to the atmosphere. In this study, we present a compilation of 1252 published gas-composition measurements. The data reveal at least three natural gas associations in the field area, which are dominated by hydrocarbons, CO2, and N2 + He + Ar, respectively. Most gas accumulations of the region exhibit compositions that are intermediate between the three end members. The first non-hydrocarbon gas association is characterized by very high-purity CO2, in excess of 75 mol% (hereafter, %). Many of these high-purity CO2 fields have recently been well described and interpreted as magmatic in origin. The second non-hydrocarbon gas association is less well described on the Colorado Plateau. It exhibits He concentrations on the order of 1-10%, and centered log ratio biplots show that He occurs proportionally to both N2 and Ar. Overall ratios of N2 to He to Ar are ?100:10:1 and correlation in concentrations of these gases suggests that they have been sourced from the same reservoir and/or by a common process. To complement the analysis of the gas-composition data, stable isotope and noble-gas isotope measurements are compiled or newly reported from 11 representative fields (previously published data from 4 fields and new data from 7 fields). Gas sampled from the Harley Dome gas field in Utah contains nearly pure N2 + He + Ar. The various compositional and stable and noble gas isotopic data for this gas indicate that noble gas molecule/isotope ratios are near crustal radiogenic production values and also suggest a crustal N2 source. Across the field area, most of the high-purity N2 + He + Ar gas accumulations are associated with the mapped surface trace of structures or sutures in the Precambrian basement and are often accumulated in lower parts of the overlying Phanerozoic sedimentary cover. The high-purity gas association mostly occurs in areas interior to the plateau that are characterized by a narrow range of elevated, moderate heat flow values (53-74 mW/m2) in the ancient (1.8-1.6 Ga) basement terranes of the region. Collectively, the geochemical and geological data suggest that (1) the N2 + He + Ar gas association is sourced from a crustal reservoir, (2) the gas association migrates preferentially along structures in the Precambrian basement, and (3) the sourcing process relates to heating of the crust. Prospecting for noble-gas accumulations may target areas with elevated Cenozoic heat flow, ancient crust, and deep crustal structures that focus gas migration. High-purity CO2 gas may also migrate through regional basement structures, however, there is not always a clear spatial association. Rather, CO2 accumulations are more clearly associated with zones of high heat flow (>63 mW/m2) that sit above hot upper mantle and are proximal to Cenozoic volcanic rocks near the plateau margins. These observations are consistent with previous interpretations of a magmatic gas source, which were based on geochemical measurements.
DS202011-2028
2020
Blondes, M.S.Apen, F.E., Rudnick, R.L., Cottle, J.M., Kylander-Clark, A.R.C., Blondes, M.S., Piccoli, P.M., Seward, G.Four dimensional thermal evolution of the East African Orogen: accessory phase petrochronology of crustal profiles through the Tanzanian Craton and Mozambique belt, northeastern Tanzania.Contributions to Mineralogy and Petrology, Vol. 175, 97, 30p. PdfAfrica, Tanzaniacraton

Abstract: U-Pb petrochronology of deep crustal xenoliths and outcrops across northeastern Tanzania track the thermal evolution of the Mozambique Belt and Tanzanian Craton following the Neoproterozoic East African Orogeny (EAO) and subsequent Neogene rifting. At the craton margin, the upper-middle crust record thermal quiescence since the Archean (2.8-2.5 Ga zircon, rutile, and apatite in granite and amphibolite xenoliths). The lower crust of the craton documents thermal pulses associated with Neoarchean ultra-high temperature metamorphism (ca. 2.64 Ga,?>?900 °C zircon), the EAO (600-500 Ma rutile), and fluid influx during rifting (?650 °C (above Pb closure of rutile and apatite) at the time of eruption. Zoned titanite records growth during cooling of the lower crust at 550 Ma, followed by fluid influx during slow cooling and exhumation (0.1-1 °C/Myr after 450 Ma). Permissible lower-crustal temperatures for the craton and orogen suggest variable mantle heat flow through the crust and reflect differences in mantle lithosphere thickness rather than advective heating from rifting.
DS1994-0171
1994
Bloodworth, A.Bloodworth, A.Minerals for development: improved industrial mineral resource evaluationin developing countriesInstitute of Mining and Metallurgy (IMM) Minerals Industry International, No. 1018, May pp. 19-22Zimbabwe, TanzaniaEconomics
DS201502-0042
2015
Bloodworth, A.Bloodworth, A.The high stakes race to satisfy our need for the scarcest metals on Earth. Book by K. Veronese Publ. PrometheusNature, Vol. 517, 7533, Jan. 8, pp. 142-143.GlobalBook review - REE
DS201708-1600
2017
Bloom, A.Bloom, A.Density measurement within the context of the rock mass characterization program of the Kelvin and Faraday kimberlites and surrounding country rock in the Northwest Territories of Canada.11th. International Kimberlite Conference, PosterCanada, Northwest Territoriesdeposit - Kelvin, Faraday
DS1991-0129
1991
Bloom, L.Bloom, L.Business opportunities in the Soviet UnionEngineering and Mining Journal, Vol. 192, No. 8, August pp. 20 U-V. 3pagesRussiaBrief -overview written six months ago, Legal
DS1993-0130
1993
Bloom, L.Bloom, L.Improving your ability to interpret the dataProspectors and Developers Association of Canada (PDAC) Meeting Preprint, 9pCanadaGeochemistry, Chemical analysis, sampling
DS1997-0106
1997
Bloom, L.Bloom, L., Titaro, D.Building confidence in assaysSociety for Mining, Metallurgy and Exploration (SME) Preprint, No. 97-109, 3pGlobalSampling, assaying, Check assays
DS1998-0026
1998
Bloom, L.Amor, S., Bloom, L.Practical application of exploration geochemistryPros. Developers Assoc, Short course approx. 200pGlobalBook - table of contents, Geochemistry - technology
DS2002-0170
2002
Bloom, L.Bloom, L., Leaver, M.Using the correct control limits. Certified Reference MaterialsExplore, No. 115, April, pp. 3,4.GlobalGeochemistry - CRM
DS1996-0141
1996
Bloom, L.M.Bloom, L.M., Pedler, P.J., Wragg, G.E.Implementation of enhanced areal interpretation using MapinfoComputers and Geosciences, Vol. 22, No. 5, pp. 459-466GlobalComputer, Program -Mapinfo remote sensing
DS200612-0140
2006
BloombergBloombergDiamonds to outpace metals as scarcity, Asia sales boost prices.Bloomberg.com, August 7, 3p.GlobalDiamond - economics
DS200812-0119
2008
BloombergBloombergNamdeb to cut gem production and fire some workers.Bloomberg.com, Dec. 12, 1/4p.Africa, NamibiaNews item - Namdeb
DS1970-0632
1973
Bloomer, A.G.Bloomer, A.G., Nixon, P.H.The Geology of the Letseng la Terae Kimberlite PipesMaseru: Lesotho Nat. Dev. Corp. Lesotho Kimberlites, Editor, PP. 20-38.LesothoGeology
DS1990-0213
1990
Bloomer, S.Bloomer, S., Stern, R.Tectonic originsNature, Vol. 346, No. 6284, August 9, p. 518GlobalTectonics, Volcanics
DS1987-0060
1987
Bloomer, S.H.Bloomer, S.H.Geochemical characteristics of boninite and tholeiite series volcanic rocks of the Mariana forearc and the role of an incompatible element enrichedfluidMantle metasomatism and alkaline magmatism, edited E. Mullen Morris and, No. 215, pp. 151-164GlobalGeochemistry, Analyses Volcanics p. 154
DS1988-0668
1988
Bloomer, S.H.Stern, R.J., Bloomer, S.H., Ping Nan Lin, Ito, E., Morris, J.Shoshonitic magmas in nascent arcs: new evidence from submarine volcanoes in the northern MarianasGeology, Vol. 16, No. 5, May pp. 426-430OceanBlank
DS1990-1027
1990
Bloomer, S.H.Meen, J.K., Bloomer, S.H., Stern, R.J.Contemporaneous alkaline shoshonite and island arcbasalt-dacite magmatism in the Mariana arc systemV.m. Goldschmidt Conference Held May 2-4, 1990, Program And Abstract, p. 65. Abstract onlyGlobalShoshonite, Alkaline rocks
DS1990-1416
1990
Bloomer, S.H.Stern, R.J., Bloomer, S.H.Mariana boninites: trace element and Strontium, neodymium, and lead isotopic constraints on the origin of LIL enriched fluids at convergent marginsV.m. Goldschmidt Conference Held May 2-4, 1990, Program And Abstract, p. 84. Abstract onlyGlobalBoninites, Geochemistry
DS2002-0171
2002
Bloomfield, C.Bloomfield, C.The development and application of health, safety, environment and community, management standards BHP Billiton.Australian Institute of Mining and Metallurgy, No. 3/2002, pp.79-82.AustraliaHSEC - management standards
DS200712-0440
2007
Bloomfield, M.Hird, J.R., Bloomfield, M., Hayward, I.P.Investigating the mechanisms of diamond polishing using Raman spectroscopy.Philosophical Magazine, Vol. 87, 2, Jan. 11, pp. 267-280.TechnologyDiamond polishing
DS201112-0095
2011
Blore, S.Blore, S., Smilie, I.Taming the resource curse: implementing the ICGLR certification mechanism for conflict prone minerals. Lessons from KPPartnership Africa Canada, March 54p.GlobalLegal outline of ICGLR principles
DS201212-0074
2012
Blott, S.J.Blott, S.J., Pye, K.Particle size scales and classification of sediment types based on particle size distributions: review and recommended procedures.Sedimentology, in press availableTechnologyClassification of sediments
DS201904-0723
2017
Blouin, M.Cate, A., Perozzi, L., Gloaguen, E., Blouin, M.Machine learning as a tool for geologists. Not specific to diamondsThe leading Edge, https://dx.doi.org/10.1190/tle36030064.1Globaldata sets

Abstract: Machine learning is becoming an appealing tool in various fields of earth sciences, especially in resources estimation. Six machine learning algorithms have been used to predict the presence of gold mineralization in drill core from geophysical logs acquired at the Lalor deposit, Manitoba, Canada. Results show that the integration of a set of rock physical properties — measured at closely spaced intervals along the drill core — with ensemble machine learning algorithms allows the detection of gold-bearing intervals with an adequate rate of success. Since the resulting prediction is continuous along the drill core, the use of this type of tool in the future will help geologists in selecting sound intervals for assay sampling and in modeling more continuous ore bodies during the entire life of a mine.
DS1970-0828
1973
Blouse, R.S.Slettene, R.L., Wilcox, L.E., Blouse, R.S., Sanders, J.R.A Bouger Gravity Anomaly Map of AfricaDefense Mapping Agency Aerospace Centre Tech. Paper., No. 73-3Africa, South Africa, BotswanaGeophysics
DS2001-0115
2001
Blower, J.D.Blower, J.D., Mader, H.M., Wilson, S.D.R.Coupling of viscous and diffusive controls on bubble growth during explosive volcanic eruptions.Earth and Planetary Science Letters, Vol. 193, No. 1-2, Nov. 30, pp. 47-56.MantlePhreatomagmatism
DS1991-0130
1991
Blowes, D.Blowes, D., Cherry, J.Mill tailings impoundments. Geochemistry and hydrologyHazardous Material Management, June pp. 6-11GlobalMining, Mill tailings ponds
DS200712-0084
2006
Blowes, D.Blowes, D.,Moncur, M., Smith, L., Sego, D., Klassen, Neuner, Gravie, Gould, ReinsonMining in the continuous permafrost: construction and instrumentation of two large scale waste rock piles.34th Yellowknife Geoscience Forum, p. 6. abstractCanada, Northwest TerritoriesMining - Diavik
DS200812-1034
2008
Blowes, D.Sego,D.C., Pham, N., Blowes, D., Smith, L.Heat transfer in waste rock piles at Diavik diamond mine.Northwest Territories Geoscience Office, p. 55. abstractCanada, Northwest TerritoriesDeposit - Diavik
DS200812-1085
2008
Blowes, D.Smith, L., Neuner, M., Gupton, M., Bailey, B.L., Blowes, D., Smith, L., Sego, D.Diavik test piles project: design and construction of large scale research waste rock piles in the Canadian Arctic.Northwest Territories Geoscience Office, p. 57-58. abstractCanada, Northwest TerritoriesDeposit - Diavik
DS201709-2072
2017
Blowes, D.Wilson, D., Amos, R., Blowes, D., Langman, J., Smith, L., Sego, D.Diavik waste rock project: scale up of a reactive transport conceptual model for temperature and sulfide dependent geochemical evolution.Goldschmidt Conference, abstract 1p.Canada, Northwest Territoriesdeposit, Diavik
DS1994-0172
1994
Blowes, D.W.Blowes, D.W., Jambor, J.L.The environmental geochemistry of sulfide mine wastesMineralogical Association of Canada Short Course, Vol. 22, 110p. $ 30.00GlobalEnvironmental geochemistry, Table of contents, Mine wastes
DS2003-0063
2003
Blowes, D.W.Baker, M.J., Blowes, D.W., Logsdon, M.J., Jambor, J.L.Environmental geochemistry of kimberlite materials: Diavik diamonds project, Lac deExploration Mining Geology ( C.I.M.), Vol. 10, 3, pp. 155-63.Northwest TerritoriesGeochemistry - whole rock analyses, ABA results, Deposit - Diavik
DS200412-0086
2003
Blowes, D.W.Baker, M.J., Blowes, D.W., Logsdon, M.J., Jambor, J.L.Environmental geochemistry of kimberlite materials: Diavik diamonds project, Lac de Gras, Northwest Territories, Canada.Exploration Mining Geology , Vol. 10, 3, pp. 155-63.Canada, Northwest TerritoriesGeochemistry - whole rock analyses, ABA results Deposit - Diavik
DS200812-0073
2008
Blowes, D.W.Bailey, B.L., Smith, L., Neuner, M., Gupton, M., Blowes, D.W., Smith, L., Sego, D.C., Gould, D.Diavik waste rock project: early stage geochemistry and microbiology of effluent from low sulfide content waste rock piles.Northwest Territories Geoscience Office, p. 11-12. abstractCanada, Northwest TerritoriesDeposit - Diavik
DS200812-0763
2008
Blowes, D.W.Moore, M.L., Blowes, D.W., Ptacek, C.J., Gould, W.D., Smith, L.,Sego, D.Humidity cell analysis of waste rock from the Diavik diamond mine NWT, Canada.Goldschmidt Conference 2008, Abstract p.A647.Canada, Northwest TerritoriesDeposit - Diavik
DS201012-0031
2010
Blowes, D.W.Bailey, B.L., Smith, L.J.D., Blowes, D.W., Ptacek, C.J., Smith, L., Sego, D.C.Diavik waste rock project: blasting residuals in waste rock piles.38th. Geoscience Forum Northwest Territories, Abstract p. 30.Canada, Northwest TerritoriesDiavik
DS201112-0409
2011
Blowes, D.W.Hannam, S., Bailey, B.L., Lindsay, M.B.J., Gibson, B., Blowes, D.W., Paktunc, A.D., Smith, L., Sego, D.C.Diavik waste rock project: geochemical and mineralogical characterization of waste rock weathering at the Diavik diamond mine.Yellowknife Geoscience Forum Abstracts for 2011, abstract p. 43-44.Canada, Northwest TerritoriesMining - waste rock
DS201212-0046
2012
Blowes, D.W.Bailey, B.L., Smith, L.J.D., Blowes, D.W.,Ptacek, C.J., Smith, L., Sego, D.C.The Diavik waste rock project: persistence of contaminants from blasting agents in waste rock effluent.Applied Geochemistry, in press availableCanada, Northwest TerritoriesDeposit - Diavik mining
DS201312-0157
2012
Blowes, D.W.Chi, X., Amos, R.T., Stastna, M., Blowes, D.W., Sego, D.C., Smith, L.The Diavik waste rock project: implications of wind-induced gas transport.Applied Geochemistry, Vol. 36, pp. 246-255.Canada, Northwest TerritoriesDeposit - Diavik, environmental
DS201312-0644
2013
Blowes, D.W.Neuner, M., Smith, L., Blowes, D.W., Sego, D.C., Smith, L.J.D., Fretz, N., Gupton, M.The Diavik waste rock project: water flow through mine waste rock in a permafrost terrain.Applied Geochemistry, Vol. 36, pp. 222-233.Canada, Northwest TerritoriesMining - Diavik
DS201312-0705
2013
Blowes, D.W.Pham, N.H., Sego, D.C., Arenson, L.U., Blowes, D.W., Amos, R.T., Smith, L.The Diavik waste rock project: measurement of the thermal regime of a waste rock test pile in a permafrost environment.Applied Geochemistry, Vol. 36, pp. 234-245.Canada, Northwest TerritoriesMining - Diavik
DS201312-0849
2013
Blowes, D.W.Smith, L.J.D., Blowes, D.W., Jambor, J.L., Smith, L., Sego, D.C., Neuner, M.The Diavik waste rock project: initial geochemical response from a low sulfide waste rock pile.Applied Geochemistry, Vol. 36, pp. 200-209.Canada, Northwest TerritoriesMining - Diavik
DS201312-0850
2013
Blowes, D.W.Bailey, B.L., Smith, L.J.D., Blowes, D.W., Ptacek, C.J., Smith, L., Sego, D.C.The Diavik waste rock project: persistence of contaminants from blasting agents in waste rock effluent.Applied Geochemistry, Vol. 36, pp. 256-270.Canada, Northwest TerritoriesMining - Diavik
DS201312-0852
2013
Blowes, D.W.Smith, L.J.D., Moncur, M.C., Neuner, M., Gupton, M., Blowes, D.W., Smith, L., Sego, D.C.The Diavik waste rock project: particle size distribution and sulfur characteristics of low- sulfide waste rock.Applied Geochemistry, Vol. 36, pp. 187-199.Canada, Northwest TerritoriesMining - Diavik
DS201507-0303
2015
Blowes, D.W.Bailey, B.L., Blowes, D.W., Smith, L., Sego, D.C.The Diavik waste rock project: geochemical and microbiological characterization of drainage from low sulfide waste rock: active zone field experiments.Applied Geochemistry, Vol. 36, pp. 187-199.Canada, Northwest TerritoriesDeposit - Diavik
DS201510-1804
2015
Blowes, D.W.Smith, L.j.D., Ptacek, C.J., Blowes, D.W., Groza, L.G., Moncur, M.C.Perchlorate in lake water from an operating mine. DiavikEnvironmental Science and Technology, Vol. 49, 13, pp. 7589-7596.Canada, Northwest TerritoriesDeposit - Diavik

Abstract: Mining-related perchlorate [ClO4(-)] in the receiving environment was investigated at the operating open-pit and underground Diavik diamond mine, Northwest Territories, Canada. Samples were collected over four years and ClO4(-) was measured in various mine waters, the 560 km(2) ultraoligotrophic receiving lake, background lake water and snow distal from the mine. Groundwaters from the underground mine had variable ClO4(-) concentrations, up to 157 ?g L(-1), and were typically an order of magnitude higher than concentrations in combined mine waters prior to treatment and discharge to the lake. Snow core samples had a mean ClO4(-) concentration of 0.021 ?g L(-1) (n=16). Snow and lake water Cl(-)/ClO4(-) ratios suggest evapoconcentration was not an important process affecting lake ClO4(-) concentrations. The multiyear mean ClO4(-) concentrations in the lake were 0.30 ?g L(-1) (n = 114) in open water and 0.24 ?g L(-1) (n = 107) under ice, much below the Canadian drinking water guideline of 6 ?g L(-1). Receiving lake concentrations of ClO4(-) generally decreased year over year and ClO4(-) was not likely [biogeo]chemically attenuated within the receiving lake. The discharge of treated mine water was shown to contribute mining-related ClO4(-) to the lake and the low concentrations after 12 years of mining were attributed to the large volume of the receiving lake.
DS201512-1896
2015
Blowes, D.W.Bailey, B.L., Blowes, D.W., Smith, L., Sego, D.C.The Diavik waste rock project: geochemical and microbiological characterization of low sulfide content large-scale waste rock test piles.Applied Geochemistry, Vol. 62, pp. 18-34.Canada, Northwest TerritoriesDeposit - Diavik

Abstract: Two experimental waste-rock piles (test piles), each 15 m in height × 60 m × 50 m, were constructed at the Diavik diamond mine in Northern Canada to study the behavior of low-sulfide content waste rock, with a similarly low acid-neutralization potential, in a continuous permafrost region. One test pile with an average of 0.035 wt.% S (<50 mm fraction; referred to as Type I) and a second test pile with an average of 0.053 wt.% S (<50 mm fraction; referred to as Type III) were constructed in 2006. The average carbon content in the <50 mm fraction of waste rock in the Type I test pile was 0.031 wt.% as C and in the Type III test pile was 0.030 wt.% as C. The NP:AP ratio, based on the arithmetic mean of particle-size weighted NP and AP values, for the Type I test pile was 12.2, suggesting this test pile was non-acid generating and for the Type III test pile was 2.2, suggesting an uncertain acid-generating potential. The Type I test pile maintained near-neutral pH for the 4-year duration of the study. Sulfate and dissolved metal concentrations were low, with the exception of Ni, Zn, Cd, and Co in the fourth year following construction. The pore water in the Type III test pile contained higher concentrations of SO42? and dissolved metals, with a decrease in pH to <4.7 and an annual depletion of alkalinity. Maximum concentrations of dissolved metals (20 mg L?1 Ni, 2.3 mg L?1 Cu, 3.7 mg L?1 Zn, 35 ?g L?1 Cd, and 3.8 mg L?1 Co) corresponded to decreases in flow rate, which were observed at the end of each field season when the contribution of the total outflow from the central portion of the test pile was greatest. Bacteria were present each year in spite of annual freeze/thaw cycles. The microbial community within the Type I test pile included a population of neutrophilic S-oxidizing bacteria. Each year, changes in the water quality of the Type III test-pile effluent were accompanied by changes in the microbial populations. Populations of acidophilic S-oxidizing bacteria and Fe-oxidizing bacteria became more abundant as the pH decreased and internal test pile temperatures increased. Irrespective of the cold-climate conditions and low S content of the waste rock, the geochemical and microbiological results of this study are consistent with other acid mine drainage studies; indicating that a series of mineral dissolution-precipitation reactions controls pH and metal mobility, and transport is controlled by matrix-dominated flow and internal temperatures.
DS201601-0002
2016
Blowes, D.W.Bailey, B.L., Blowes, D.W., Smith, L., Sego, D.C.The Diavik waste rock project: geochemical and microbiological characterization of low sulfide content large-scale waste rock test piles.Applied Geochemistry, Vol. 65, pp. 54-72.Canada, Northwest TerritoriesDeposit - Diavik

Abstract: Two experimental waste-rock piles (test piles), each 15 m in height × 60 m × 50 m, were constructed at the Diavik diamond mine in Northern Canada to study the behavior of low-sulfide content waste rock, with a similarly low acid-neutralization potential, in a continuous permafrost region. One test pile with an average of 0.035 wt.% S (<50 mm fraction; referred to as Type I) and a second test pile with an average of 0.053 wt.% S (<50 mm fraction; referred to as Type III) were constructed in 2006. The average carbon content in the <50 mm fraction of waste rock in the Type I test pile was 0.031 wt.% as C and in the Type III test pile was 0.030 wt.% as C. The NP:AP ratio, based on the arithmetic mean of particle-size weighted NP and AP values, for the Type I test pile was 12.2, suggesting this test pile was non-acid generating and for the Type III test pile was 2.2, suggesting an uncertain acid-generating potential. The Type I test pile maintained near-neutral pH for the 4-year duration of the study. Sulfate and dissolved metal concentrations were low, with the exception of Ni, Zn, Cd, and Co in the fourth year following construction. The pore water in the Type III test pile contained higher concentrations of SO42? and dissolved metals, with a decrease in pH to <4.7 and an annual depletion of alkalinity. Maximum concentrations of dissolved metals (20 mg L?1 Ni, 2.3 mg L?1 Cu, 3.7 mg L?1 Zn, 35 ?g L?1 Cd, and 3.8 mg L?1 Co) corresponded to decreases in flow rate, which were observed at the end of each field season when the contribution of the total outflow from the central portion of the test pile was greatest. Bacteria were present each year in spite of annual freeze/thaw cycles. The microbial community within the Type I test pile included a population of neutrophilic S-oxidizing bacteria. Each year, changes in the water quality of the Type III test-pile effluent were accompanied by changes in the microbial populations. Populations of acidophilic S-oxidizing bacteria and Fe-oxidizing bacteria became more abundant as the pH decreased and internal test pile temperatures increased. Irrespective of the cold-climate conditions and low S content of the waste rock, the geochemical and microbiological results of this study are consistent with other acid mine drainage studies; indicating that a series of mineral dissolution-precipitation reactions controls pH and metal mobility, and transport is controlled by matrix-dominated flow and internal temperatures.
DS201801-0081
2018
Blowes, D.W.Wilson, D., Amos, R.T., Blowes, D.W., Langman, J.B., Ptacek, C.J., Smith, L., Sego, D.C.Diavik waste rock project: a conceptual model for temperature and sulfide content dependent geochemical evolution of waste rock - Laboratory scale.Applied Geochemistry, Vol. 89, pp. 160-172.Canada, Northwest Territoriesdeposit - Diavik

Abstract: The Diavik Waste Rock Project consists of laboratory and field experiments developed for the investigation and scale-up of the geochemical evolution of sulfidic mine wastes. As part of this project, humidity cell experiments were conducted to assess the long-term geochemical evolution of a low-sulfide waste rock. Reactive transport modelling was used to assess the significant geochemical processes controlling oxidation of sulfide minerals and their dependence on temperature and sulfide mineral content. The geochemical evolution of effluent from waste rock with a sulfide content of 0.16 wt.% and 0.02 wt.% in humidity cells was simulated with the reactive transport model MIN3P, based on a conceptual model that included constant water flow, sulfide mineral content, sulfide oxidation controlled by the availability of oxidants, and subsequent neutralization reactions with carbonate and aluminosilicate minerals. Concentrations of Ni, Co, Cu, Zn, and SO4 in the humidity cell effluent were simulated using the shrinking core model, which represented the control of oxidant diffusion to the unreacted particle surface in the sulfide oxidation process. The influence of temperature was accounted for using the Arrhenius relation and appropriate activation energy values. Comparison of the experiment results, consisting of waste rock differentiated by sulfide mineral content and temperature, indicated surface area and temperature play important roles in rates of sulfide oxidation and release of sulfate and metals. After the model was calibrated to fit the effluent data from the higher sulfide content cells, subsequent simulations were conducted by adjusting only measured parameters, including sulfide mineral content and surface area.
DS201809-2115
2018
Blowes, D.W.Wilson, D., Amos, R.T., Blowes, D.W., Langman, J.B., Smith, L., Sego, D.C.Diavik waste rock project: Scale up of a reactive transport model for temperature and sulfide content dependent geochemical evolution of waste rock.Applied Geochemisty, Vol. 96, pp. 177-190.Canada, Northwest Territoriesdeposit - Diavik

Abstract: The Diavik Waste Rock Project, located in a region of continuous permafrost in northern Canada, includes complementary field and laboratory experiments with the purpose of investigating scale-up techniques for the assessment of the geochemical evolution of mine waste rock at a large scale. As part of the Diavik project, medium-scale field experiments (?1.5?m high active zone lysimeters) were conducted to assess the long term geochemical evolution and drainage of a low-sulfide waste rock under a relatively simple (i.e. constrained by the container) flow regime while exposed to atmospheric conditions. A conceptual model, including the most significant processes controlling the sulfide-mineral oxidation and weathering of the associated host minerals as observed in a laboratory humidity cell experiment, was developed as part of a previous modelling study. The current study investigated the efficacy of scaling the calibrated humidity cell model to simulate the geochemical evolution of the active zone lysimeter experiments. The humidity cell model was used to simulate the geochemical evolution of low-sulfide waste rock with S content of 0.053?wt.% and 0.035?wt.% (primarily pyrrhotite) in the active zone lysimeter experiments using the reactive transport code MIN3P. Water flow through the lysimeters was simulated using temporally variable infiltration estimated from precipitation measurements made within 200?m of the lysimeters. Flow parameters and physical properties determined during previous studies at Diavik were incorporated into the simulations to reproduce the flow regime. The geochemical evolution of the waste-rock system was simulated by adjustment of the sulfide-mineral content to reflect the values measured at the lysimeters. The temperature dependence of the geochemical system was considered using temperature measurements taken daily, adjacent to the lysimeters, to correct weathering rates according to the Arrhenius equation. The lysimeter simulations indicated that a model developed from simulations of laboratory humidity cell experiments, incorporating detailed representations of temporally variable temperature and water infiltration, can be scaled to provide a reasonable assessment of geochemical evolution of the medium-scale field experiments.
DS201809-2116
2018
Blowes, D.W.Wilson, D., Sinclair, S.A., Blowes, D.W., Amos,R.T., Smith, L., Sego, D.C.Diavik waste rock project: analysis of measured and simulated acid neutralization processes within a large scale field experiment.Goldschmidt Conference, 1p. AbstractCanada, Northwest Territoriesdeposit - Diavik

Abstract: The geochemical evolution of mine-waste rock often includes concurrent acid generation and neutralization processes. Deposition of mine-waste rock in large, oxygenated, and partially saturated piles can result in release of metals and decreased pH from weathering of sulfide minerals. Acid neutralization processes can often mitigate metals and pH impacts associated with sulfide oxidation. The Diavik Waste Rock Project included large field experiments (test piles built in 2006) conducted to characterize weathering of sulfide waste rock at a scale representative of full size waste-rock piles. Water samples from the unsaturated interior of one of the test piles, constructed of waste rock with ~0.05 wt.% S, were collected using soil water solution samplers and drains at the base of the pile. Field observations indicated pH decreased throughout the depth of the pile during 2008 and 2009 and that carbonate mineral buffering was entirely depleted by 2011 or 2012. Carbonate mineral exhaustion was accompanied by increased concentrations of dissolved Al and Fe in effluent samples collected at the basal drains. These results suggest that dissolution of Al and Fe(oxy)hydroxides occurred after the depletion of carbonate minerals following an acid neutralization sequence that is similar to observations made by previous researchers. A conceptual model of acid neutralization proceses within the pile, developed using physical and geochemical measurements conducted from 2008 to 2012, was used to inform reactive transport simulations conducted in 2017 to quantify the dominant acid neutralization processes within the test pile interior. Reactive transport simulations indicate that the conceptual model developed using the results of field samples provides a reasonable assessment of the evolution of the acid neutralization sequence.
DS1950-0457
1959
Bloxam, T.W.Bloxam, T.W.Glaucophane Schists and Associated Rocks Near Valley Ford, CaliforniaAmerican Journal of Science, Vol. 257, PP. 95-112.GlobalKimberlite
DS1950-0458
1959
Bloxam, T.W.Bloxam, T.W., Allen, J.B.Glaucophane Schist, Eclogite and Associated Rocks from Knock normal in the Girvan Ballantrae Complex, South Ayrshire.Royal Society. EDINBURGH Transactions, Vol. 64, PP. 1-28.ScotlandRelated Rocks
DS1989-0128
1989
Bloxham, J.Bloxham, J., Gubbins, D.The evolution of the earth's magnetic fieldScientific American, Vol. 261, No. 6, December pp. 68-75GlobalGeophysics, Overview - magnetic fields
DS1991-0131
1991
Bloxham, J.Bloxham, J., Jackson, A.Fluid flow near the surface of earth's outer coreReviews of Geophysics, Vol. 29, No. 1, February pp. 97-120GlobalEarth's core, Core/mantle
DS1993-0131
1993
Bloxham, J.Bloxham, J.Mapping the magnetic field at the core-mantle boundary: constraints on thegeodyanamoGsa Today, Vol. 3, No. 9, September pp. 1, 224, 225, 229-233MantleGeophysics -seismics, Geotectonics
DS1994-1055
1994
Bloxham, J.Love, J.J., Bloxham, J.Electromagnetic coupling and the toroidal magnetic field at the core-mantleboundary.Geophys. Journal of International, Vol. 117, No. 1, April pp. 235-256.MantleGeophysics -magnetics, Boundary -experimental
DS1997-1292
1997
Bloxham, J.Zatman, S., Bloxham, J.Torsional oscillations and the magnetic field within the Earth's coreNature, Vol. 388, Aug. 21, pp. 760-763.MantleGeophysics - magnetics
DS2002-0172
2002
Bloxham, J.Bloxham, J.Time independent and time dependent behaviour of high latitude flux bundles at the core-mantle boundary.Geophysical Research Letters, Vol. 29, 18, 10.1029/2001GLO14543MantleGeophysics
DS1991-0369
1991
Bluck, B.J.Dempster, T.J., Bluck, B.J.Xenoliths in the lamprophyre dykes of Lomondside: constraints on the nature of the crust beneath the southern DalradianScottish Journal of Geology, Vol. 27, pt. 2, pp. 157-166ScotlandLamprophyres, Xenoliths
DS1999-0329
1999
Bluck, B.J.Jacob, R.J., Bluck, B.J., Ward, J.D.Tertiary age Diamondiferous fluvial deposits of the Lower Orange RiverValley, southwestern Africa.Economic Geology, Vol. 94, No. 5, Aug. pp. 749-58.South AfricaDiamond alluvials, Orange River area
DS2002-0054
2002
Bluck, B.J.Apollis, L., Bluck, B.J., Ward, J.D.The distribution of diamonds on a Late Cenzoic gravel beach, sw Namibia.( Orange River mouth).11th. Quadrennial Iagod Symposium And Geocongress 2002 Held Windhoek, Abstract p. 18.NamibiaGeomorphology, alluvials
DS2003-0120
2003
Bluck, B.J.Bluck, B.J., Ward, J.D., De Wit, M.J.The making of a diamond mega-placer on the margin of the Kalahari craton: guidelinesTransactions of the Institution of Mining and Metallurgy, Vol. 112, August p. 199. (1p.)South AfricaPlacers, alluvials
DS200412-0165
2003
Bluck, B.J.Bluck, B.J., Ward, J.D., De Wit, M.J.The making of a diamond mega-placer on the margin of the Kalahari craton: guidelines for future prospecting.Transactions of the Institution of Mining and Metallurgy, Vol. 112, August p. 199. (1p.)Africa, South AfricaPlacers, alluvials
DS200612-0141
2005
Bluck, B.J.Bluck, B.J., Ward, D.J., De Wit, M.C.J.Diamond megaplacers, southern Africa and the Kaapvaal Craton in a global context.Geological Society of London Special Paper, No. 248, pp. 213-246.Africa, South AfricaPlacers, alluvials
DS200612-0632
2006
Bluck, B.J.Jacob, J., Ward, J.D., Bluck, B.J., Scholz, R.A., Frimmel, H.E.Some observations on Diamondiferous bedrock gully trapsites on Late Cainozoic, marine cut platforms of the Sperrgebiet, Namibia.Ore Geology Reviews, Vol. 28, 4, pp. 493-506.Africa, NamibiaGeomorphology, alluvials, placers
DS200612-1339
2006
Bluck, B.J.Spaggiari, R.I., Bluck, B.J., Ward, J.D.Characteristics of Diamondiferous Plio PLeistocene littoral deposits within the palaeo Orange River mouth, Namibia.Ore Geology Reviews, Vol. 28, 4, pp. 475-492.Africa, NamibiaGeomorphology, alluvials, placers, marine
DS201012-0059
2010
Bluck, B.J.Bluck, B.J.Structure of gravel beaches and their relationship to tidal range.Sedimentology, in press availableNot specific to diamonds but of interest
DS1900-0013
1900
Blue, A.Blue, A.Are There Diamonds in Ontario?Ontario Bureau of Mines Annual Report, Vol. 9, PP. 119-124. ALSO: Canadian Mining Journal, Vol. 3, PP. 149-Canada, Ontario, Great LakesDiamond Occurrence
DS1900-0056
1901
Blue, A.Blue, A.Diamond Mining. #3Australia Mining Standard., Vol. 20, PP. 46-47.Africa, South AfricaMining
DS1900-0057
1901
Blue, A.Blue, A.Source of Diamonds in Glacial MoraineMineral Resources of The United States For 1899, P. 8.United States, Wisconsin, Ohio, Great Lakes, CanadaDiamond Occurrence
DS200412-0166
2003
Blue Diamond Mining CorporationBlue Diamond Mining CorporationBlue Diamond has started work on its Lac Joubert and Schmidt properties.Blue Diamond Mining Corporation, Dec. 4, 1p.Canada, Quebec, Otish MountainsNews item - press release
DS1981-0086
1981
Bluechel, K.Bluechel, K., Medenbach, O.The Wonder of Minerals; Crystals, Gold and Precious StonesDokumente., 287P.GlobalDiamonds, Kimberlite, Kimberley
DS201512-1899
2015
Bluemel, B.Bluemel, B., Dunn, C., Hart, C., Leijd, M.Biogeochemical expressions of buried REE mineralization at Norra Karr, southern Sweden.Symposium on critical and strategic materials, British Columbia Geological Survey Paper 2015-3, held Nov. 13-14, pp. 231-240.TechnologyRare earths

Abstract: Biogeochemical exploration is an effective but underutilized method for delineating covered mineralization. Plants are capable of accumulating rare earth elements (REEs) in their tissue, and ferns (pteridophytes) are especially adept because they are one of the most primitive land plants, therefore lack the barrier mechanisms developed by more evolved plants. The Norra Kärr Alkaline Complex, located in southern Sweden approximately 300km southwest of Stockholm, is a peralkaline nepheline syenite enriched in heavy rare earth elements (HREEs). The deposit, roughly 300m wide, 1300m long, and overlain by up to 4 m of Quaternary sediments, has been well-defined by diamond drilling. The inferred REE mineral resource, over 60 million tonnes averaging 0.54% Total Rare Earth Oxide (TREO), is dominantly hosted within the pegmatitic “grennaite” unit, a eudialyte-catapleiite-aegerine nepheline syenite. Vegetation and soil samples were collected from the surficial environment above Norra Kärr to address four key questions: which plant species is the most effective biogeochemical exploration medium; what are the annual and seasonal REE variations in that plant; how do the REEs move through the soil profile; and into which part of the plant are they concentrated. Athyrium filix-femina (lady fern) has the highest concentration of LREEs and HREEs (up to 125.17ppm Ce and 1.03ppm Dy) in its dry leaves; however, there is better contrast between background and anomalous areas in Dryopteris filix-mas (wood fern), which makes it the preferred biogeochemical sampling medium. The REE content in all fern species was shown to decrease from root > frond > stem, and chondrite normalized REE patterns within the plant displayed preferential fractionation of the LREEs in the fronds relative to the roots. Samples collected from an area directly overlying the deposit had up to five times greater HREE content (0.74ppm Dy) in August than the same plants did in June (0.14ppm Dy). The elevated REE content and distinct contrast to background demonstrate that biogeochemical sampling is an effective method for REE exploration in this environment.
DS1985-0068
1985
Bluemel, G.Bluemel, G., Lahner, L.Minas Gerais, Brasil; Myths and Realities.(in German)Geologische Blaetter Fuer Nordost Bayern Und Angrenzende Gebiete, Vol. 34-35, pp. 735-754BrazilDiamonds Discussed, Overview
DS1995-0004
1995
Bluemle, J.P.Aber, J.S., Bluemle, J.P., Brighton-Grette, J., et al.Glaciotectonic map of North AmericaGeological Society of America (GSA) Map, No. MCHO79, 1: 6, 500, 000 $ 21.00Canada, United StatesMap, Glaciology, glacial, structures
DS1984-0158
1984
Blum, A.E.Blum, A.E.Chemical weathering and controls on the chemistry of infiltrating solutions in a forested watershed, Medicine BowMountains, WyomingMsc. Thesis, University of Wyoming, 89pWyomingBlank
DS2003-1263
2003
Blum, J.Shen, Y., Blum, J.Seismic evidence for accumulated oceanic crust above the 660 km discontinuityGeophysical Research Letters, Vol. 30, 18, 1925 DOI.1029/2003GLO17991South AfricaMantle, subductioon, geophysics - seismics, Ca-perovski
DS200412-0167
2004
Blum, J.Blum, J., Shen, Y.Thermal, hydrous and mechanical states of the mantle transition zone beneath southern Africa.Earth and Planetary Science Letters, Vol. 217, 3-4, pp. 367-378.Africa, South AfricaGeophysics - seismics, geothermometry. discontinuity, c
DS200412-1802
2003
Blum, J.Shen, Y., Blum, J.Seismic evidence for accumulated oceanic crust above the 660 km discontinuity beneath southern Africa.Geophysical Research Letters, Vol. 30, 18, 1925 DOI.1029/2003 GLO17991Africa, South AfricaMantle, subductioon, geophysics - seismics, Ca-perovski
DS1860-0542
1887
Blum, J.R.Blum, J.R.Taschenbuch der EdelsteinkundeLeipzig:, GlobalGemology
DS1940-0092
1945
Blum, V.J.Blum, V.J.The Magnetic Field over Igneous PipesGeophysics, Vol. 10, PP. 368-375.GlobalKimberlite, Geophysics
DS1998-0905
1998
Blume, J.Lutjen, H., Blume, J., Pretorius, C.C.Geophysical survey over the Elizabeth Bay mine, Namibia. ( aeoliandeposits).7th International Kimberlite Conference Abstract, pp. 518-20.NamibiaGeophysics - seismics, resistivity, borehole, Deposit - Elizabeth Bay
DS1998-1186
1998
Blume, J.Pretorius, C.C., Blume, J., Lutjen, TrofimczykResults of geophysical trials to profile the kimberlite/host rock contacts at Venetia and BK-9 pipe.7th. Kimberlite Conference abstract, pp. 708-9.South Africa, BotswanaGeophysics - resistivity imaging, Deposit - Venetia, BK-9
DS1999-0636
1999
Blumel, P.Schulte, B.A., Blumel, P.Metamorphic evolution of eclogite and associated garnet mica schist in the high pressure metamorphic Maksyutov.Geologische Rundschau, Vol. 87, No. 4, pp. 561-76.Russia, UralsComplex - Maksyutov, Eclogite, metamorphic
DS200612-0082
2006
Blumenau, A.T.Bangert, U., Barnes, R., Hounsome, L.S., Jones, R., Blumenau, A.T., Briddon, P.R., Shaw, M.J., Oberg, S.Electron energy loss spectroscopic studies of brown diamonds.Philosophical Magazine, Vol. 86, no. 29/31, pp. 4757-4780.TechnologyBrown diamonds
DS202201-0006
2021
Blumentritt, F.Blumentritt, F., Fritsch, E.Photochromism and photochromic gems: a review and some new data. Part 1.Journal of Gemmology, Vol. 37, 8, 780-800. pdfGlobalspectra - EM radiation
DS1996-0585
1996
Blundell, D.Hall, R., Blundell, D.Tectonic evolution of southeast AsiaGeological Society of London, Special Publication No. 106, 600p. approx. 175.00 UnitedPhilippines, Indonesia, Laos, Thailand, Papua New Guinea, ChinaBook -table of contents, Tectonics, ophiolites, Banda arc, orogeny, Bacan
DS1998-0133
1998
Blundell, D.Blundell, D., Scott, A.C.Lyell: the past is the key to the presentGeological Society of London Spec. Pub, No. 143, 376p. $ 132.00GlobalBook - ad, History of science
DS1975-0243
1976
Blundell, D.J.Blundell, D.J.Active Faults in West AfricaEarth Planet. Sci. Letters, Vol. 31, PP. 287-290.West Africa, GuineaStructure, Tectonics
DS1990-0214
1990
Blundell, D.J.Blundell, D.J.Seismic images of continental lithosphereJournal of Geological Society of London, Vol. 147, pp. 895-913.MantleGeophysics - seismics, Moho, lithosphere
DS1990-0215
1990
Blundell, D.J.Blundell, D.J., Gibbs, A.D.Tectonic evolution of the North Sea riftsClarendon Press, Oxford, 272p. Cost?North SeaTectonics, Rifting
DS1996-0586
1996
Blundell, D.J.Hall, R., Blundell, D.J.Tectonic evolution of southeast Asia: introductionGeological Society of London Special Paper, No. 106, pp. Vii-XiiiGlobalTectonics
DS2002-0173
2002
Blundell, D.J.Blundell, D.J., Neubauer, F., Von Quadt, A.The timing and location of major ore deposits in an evolving orogenGeological Society of London (U.K.), 368p.$ 142.00 http://bookshop.geolsoc.org.ukGlobalBook - metallogeny, GEODE conference papers
DS2003-0121
2003
Blundell, D.J.Blundell, D.J., Neubauer, F., Von Quadt, A.The timing and location of major ore deposits in an evolving orogenGeological Society of London Special Paper, No. 204, 368p. $200. www.geolsoc.orgGlobalGeodynamic processes, metallogeny, Book - not specific to diamonds
DS1998-1518
1998
BlundyVan Westerenen, W., Blundy, Purton, WoodTowards a predictive model for garnet melt trace element partitioning:experimental and computational..Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1580-1.MantleGeochemistry, Garnets, grossular
DS200912-0805
2009
BlundyWalter, M.J., Bulanova, G.P., Armstrong, L.S., Keshav, S., Blundy, Gudfinnsson, Lord, Lennie, Clark, GobboPrimary carbonatite melt from deeply subducted oceanic crust.Nature, Vol. 459, July 31, pp. 622-626.South America, Brazil, MantleMelting, geochemistry
DS2000-0091
2000
Blundy, J.Blundy, J., Dalton, J.Experimental comparison of trace element partitioning between clinopyroxene and melt in carbonate silicate..Contributions to Mineralogy and Petrology, Vol. 139, No. 3, pp. 356-MantleMetasomatism
DS2000-0092
2000
Blundy, J.Blundy, J., Dalton, J.Experimental comparison of trace element partioning between clinopyroxene and melt in carbonate, silicate..Contributions to Mineralogy and Petrology, Vol. 139, No. 3, pp. 356-71.MantlePetrogenesis, Mantle Metasomatism
DS2001-0653
2001
Blundy, J.Landwehr, D., Blundy, J., Chamorro-Perez, Hill, E., WoodU series disequilibration temperatures generated by partial melting of spinel lherzoliteEarth and Planetary Science Letters, Vol. 188, No. 3-4, pp. 329-48.MantleMelting, lherzolite
DS2003-0122
2003
Blundy, J.Blundy, J., Wood, B.Partitioning of trace elements between crystals and meltsEarth and Planetary Science Letters, Vol. 210, 3-4, pp. 383-397.GlobalBlank
DS200412-0168
2004
Blundy, J.Blundy, J., Brooker, R.Chemical discrimination between melts from the lower crust and slab.Lithos, ABSTRACTS only, Vol. 73, p. S10. abstractMantleSubduction
DS200412-0169
2003
Blundy, J.Blundy, J., Wood, B.Partitioning of trace elements between crystals and melts.Earth and Planetary Science Letters, Vol. 210, 3-4, pp. 383-397.TechnologyMineral chemistry
DS201012-0079
2010
Blundy, J.Bulanova, G.P., Walter, M.J., Smith, C.B.,Kohn, C.C.,Armstrong, L.S., Blundy, J.,Gobbo, L.Mineral inclusions in sublithospheric diamonds from Collier 4 kimberlite pipe, Juina, Brazil: subducted protoliths, carbonated melts and primary kimberlite ..Contributions to Mineralogy and Petrology, Vol. 160, 4, pp. 489-50.South America, BrazilMagmatism
DS201412-0099
2014
Blundy, J.Caricchi, L., Annen, C., Blundy, J., Simpson, G., Pinel, V.Supervolcanoes erupt by their own rules. Mega-eruptions and smaller volcanoes are triggered by different mechanisms.Nature Geoscience, Jan. 5, 2p.MantleVolcanoes
DS201901-0042
2018
Blundy, J.Jackson, M.D., Blundy, J., Sparks, R.S.J. Chemical differentiation, cold storage and remobilization of magma in the Earth's crust.Nature, Vol. 564, pp. 405-409.Mantlemagmatism

Abstract: The formation, storage and chemical differentiation of magma in the Earth’s crust is of fundamental importance in igneous geology and volcanology. Recent data are challenging the high-melt-fraction ‘magma chamber’ paradigm that has underpinned models of crustal magmatism for over a century, suggesting instead that magma is normally stored in low-melt-fraction "mush reservoirs". A mush reservoir comprises a porous and permeable framework of closely packed crystals with melt present in the pore space1,10. However, many common features of crustal magmatism have not yet been explained by either the ‘chamber’ or ‘mush reservoir’ concepts. Here we show that reactive melt flow is a critical, but hitherto neglected, process in crustal mush reservoirs, caused by buoyant melt percolating upwards through, and reacting with, the crystals. Reactive melt flow in mush reservoirs produces the low-crystallinity, chemically differentiated (silicic) magmas that ascend to form shallower intrusions or erupt to the surface. These magmas can host much older crystals, stored at low and even sub-solidus temperatures, consistent with crystal chemistry data. Changes in local bulk composition caused by reactive melt flow, rather than large increases in temperature, produce the rapid increase in melt fraction that remobilizes these cool- or cold-stored crystals. Reactive flow can also produce bimodality in magma compositions sourced from mid- to lower-crustal reservoirs. Trace-element profiles generated by reactive flow are similar to those observed in a well studied reservoir now exposed at the surface. We propose that magma storage and differentiation primarily occurs by reactive melt flow in long-lived mush reservoirs, rather than by the commonly invoked process of fractional crystallization in magma chambers.
DS202002-0166
2019
Blundy, J.Blundy, J.Carbon - beautiful, essential, deadly.Elements, Vol. 15, p. 367 1p.Globalcarbon
DS1991-0132
1991
Blundy, J.D.Blundy, J.D., Brodholt, J.P., Wood, B.J.Carbon-fluid equilibration temperatures and the oxidation state of the upper mantleNature, Vol. 349, No. 6307, January 24, pp. 321-323GlobalMantle, Geochemistry
DS1998-1592
1998
Blundy, J.D.Wood, B.J., Blundy, J.D., Robinson, J.A.C.Crystal chemical constraints on the partitioning of U series elements during mantle melting.Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1664.MantlePetrology - experimental
DS1999-0806
1999
Blundy, J.D.Wood, B.J., Blundy, J.D., Robinson, J.A.C.The role of clinopyroxene in generating U series disequilibrium during mantle melting.Geochimica Et Cosmochimica Acta, Vol. 63, No. 10, May 1, pp. 1613-20.MantleMelting - clinopyroxenes
DS2000-0359
2000
Blundy, J.D.Green, T.H., Blundy, J.D., Adam, J., Yaxley, G.M.SIMS determination of trace element partition coefficients between clinopyroxene and basaltsLithos, Vol. 53, No. 3-4, Sept. 1, pp. 165-87.GlobalPetrology - experimental, Garnet
DS2000-0360
2000
Blundy, J.D.Green, T.H., Blundy, J.D., Adam, J., Yaxley, G.M.SIMS determination of trace element partion coefficients between garnet, clinopyroxene and basalticLithos, Vol. 53, No. 3-4, Sept. pp. 165-87.GlobalPetrology - experimental, Gpa and Temp
DS2000-0410
2000
Blundy, J.D.Hill, E., Wood, B.J., Blundy, J.D.The effect of Ca Tschermaks component on trace element partitioning between clinopyroxene and silicate melt.Lithos, Vol. 53, No. 3-4, Sept. 1, pp. 203-15.GlobalPetrology - experimental, Clinopyroxene
DS2000-0411
2000
Blundy, J.D.Hill, E., Wood, B.J., Blundy, J.D.The effect of Ca Tschermaks component on trace element partioning between clinopyroxene and silicate melt.Lithos, Vol. 53, No. 3-4, Sept. pp. 203-15.GlobalPetrology - experimental, Mineralogy - clinopyroxene
DS2000-0554
2000
Blundy, J.D.Law, K.M., Blundy, J.D., Wood, B.J., Ragnarsdottir, K.Trace element partioning between wollastonite and silicate carbonate meltMineralogical Magazine, Vol. 64, No. 4, Aug. pp. 651-62.GlobalGeochemistry, Carbonatite
DS2000-0972
2000
Blundy, J.D.Van Westeren, W., Blundy, J.D., Wood, B.J.Effect of Fe2 on garnet melt trace element partioning: experiments in FCMAS crystal chemical controls naturalLithos, Vol. 53, No. 3-4, Sept. pp. 189-201.GlobalPetrology - experimental, Mineralogy - garnet
DS2001-1189
2001
Blundy, J.D.Van Westrenen, W., Wood, B.J., Blundy, J.D.A predictive thermodynamic model of garnet melt trace element partitioningContributions to Mineralogy and Petrology, Vol. 142, No. 2, Nov. pp. 219-234.GlobalGarnet - mineralogy
DS2002-1734
2002
Blundy, J.D.Wood, B.J., Blundy, J.D.The effect of H2O on crystal melt partitiioning of trace elementsGeochimica et Cosmochimica Acta, Vol. 66, 20, pp. 3647-56.GlobalGeochemistry - melting, water
DS2003-0170
2003
Blundy, J.D.Brooker, R.A., Du, Z., Blundy, J.D., Kelley, S.P., Allan, N.L., Wood, B.J.The zero charge partitioning behaviour of noble gases during mantle meltingNature, No. 6941, June 12, pp. 738-41.MantleBlank
DS2003-0908
2003
Blundy, J.D.McDade, P., Blundy, J.D., Wood, B.J.Trace element partitioning between mantle wedge peridotite and hydrous MgO richAmerican Mineralogist, Vol. 88, pp. 1825-31.Mantle, AntillesSlab, subduction, LILE
DS200412-0220
2003
Blundy, J.D.Brooker, R.A., Du, Z., Blundy, J.D., Kelley, S.P., Allan, N.L., Wood, B.J., Chamorro, E.M., Wartho, J.A., PurtThe zero charge partitioning behaviour of noble gases during mantle melting.Nature, No. 6941, June 12, pp. 738-41.MantleMelt, geochemistry
DS200412-1266
2003
Blundy, J.D.McDade, P., Blundy, J.D., Wood, B.J.Trace element partitioning between mantle wedge peridotite and hydrous MgO rich melt.American Mineralogist, Vol. 88, pp. 1825-31.Mantle, AntillesSlab, subduction, LILE
DS200512-0115
2004
Blundy, J.D.Brooker, R.A., James, R.H., Blundy, J.D.Trace elements and Li isotope systematics in Zabargad peridotites: evidence of ancient subduction processes in the Red Sea mantle.Chemical Geology, Vol. 212, 1-2, pp. 179-204.Mantle, EuropeSubduction
DS200612-0029
2006
Blundy, J.D.Annen, C., Blundy, J.D., Sparks, R.S.J.The genesis of intermediate and silicic magmas in deep crustal hot zones.Journal of Petrology, Vol. 47, 3, pp. 505-539.MantleMagmatism - not specific to diamonds
DS201112-0795
2011
Blundy, J.D.Pickles, J., Blundy, J.D., Sweeney, R., Smith, C.B.Experimental investigation of garnet cpx geobarometers in eclogites.Goldschmidt Conference 2011, abstract p.1640.TechnologyGeothermometry
DS201212-0556
2012
Blundy, J.D.Pinilla, C., Davis, S.E., Scott, T.B., Allan, N.L., Blundy, J.D.Interfacial storage of noble gases and oher trace elements in magmatic systems.Earth and Planetary Science Letters, Vol. 319-320, pp. 287-294.MantleBulk silicates
DS201212-0687
2012
Blundy, J.D.Solano, J.M.S., Jackson, M.D., Sparks, R.S.J., Blundy, J.D., Annen, C.Melt segregation in deep crustal hot zones: a mechanism for chemical differentiation, crustal assimilation and the formation of evolved magmas.Journal of Petrology, Vol. 53, 10, pp. 1999-2026.MantleHotspots, magmatism
DS201605-0812
2016
Blundy, J.D.Blundy, J.D., Annen, C.J.Enigmatic relationship between silicic volcanic and plutonic rocks: crustal magmatic systems from the perspective of heat transfer.Elements, Vol. 12, pp. 115-120.TechnologyMagmatism
DS201607-1311
2016
Blundy, J.D.Pickels, J.R., Blundy, J.D., Brroker, R.A.Trace element thermometry of garnet-clinopyroxene pairs. ( diamond formation)American Mineralogist, Vol. 101, pp. 1438-1450.MantleGeothermometry

Abstract: We present major and trace element data on coexisting garnet and clinopyroxene from experiments carried out between 1.3 and 10 GPa and 970 and 1400 °C. We demonstrate that the lattice strain model, which was developed for applications to mineral-melt partitioning, can be adapted to garnet-clinopyroxene partitioning. Using new and published experimental data we develop a geothermometer for coexisting garnet and clinopyroxene using the concentration of rare earth elements (REE). The thermometer, which is based on an extension of the lattice strain model, exploits the tendency of minerals at elevated temperatures to be less discriminating against cations that are too large or too small for lattice sites. The extent of discrimination against misfit cations is also related to the apparent elasticity of the lattice site on which substitution occurs, in this case the greater stiffness of the dodecahedral X-site in garnet compared with the eightfold M2-site in clinopyroxene. We demonstrate that the ratio of REE in clinopyroxene to that in coexisting garnet is particularly sensitive to temperature. We present a method whereby knowledge of the major and REE chemistry of garnet and clinopyroxene can be used to solve for the equilibrium temperature. The method is applicable to any scenario in which the two minerals are in equilibrium, both above and below the solidus, and where the mole fraction of grossular in garnet is less than 0.4. Our method, which can be widely applied to both peridotitic and eclogitic paragenesis with particular potential for diamond exploration studies, has the advantage over commonly used Fe-Mg exchange thermometers in having a higher closure temperature because of slow interdiffusion of REE. The uncertainty in the calculated temperatures, based on the experimental data set, is less than ±80 °C.
DS2002-0863
2002
Blundym J.D.Klemme, S., Blundym J.D., Wood, B.J.Experimental constraints on major and trace element partitioning during partial melting of eclogite.Geochimica et Cosmochimica Acta, Vol. 66, 17, pp. 3109-23.MantleEclogites
DS202202-0217
2022
Blundym J.D.Sparks, R.S.J., Blundym J.D., Cashman, K.V., Jackson, M., Rust, A., Wilson, C.J.N.Large silicic magma bodies and very large magnitude explosive eruptions. *** not specific to diamondsBulletin of Volcanology, Vol. 84, 8, 6p. PdfMantlemagmatism

Abstract: Over the last 20 years, new concepts have emerged into understanding the processes that lead to build up to large silicic explosive eruptions based on integration of geophysical, geochemical, petrological, geochronological and dynamical modelling. Silicic melts are generated within magma systems extending throughout the crust by segregation from mushy zones. Segregated melt layers become unstable and can assemble into ephemeral upper crustal magma chambers rapidly prior to eruption. In the next 10 years, we can expect major advances in dynamical models as well as in analytical and geophysical methods, which need to be underpinned in field research.
DS2001-1165
2001
BlushanTorsvik, T.H., Carter, L.M., Ashwal, Blushan, PanditRodinia refined or obscured; paleomagnetism of the Malani igneous suitePrecambrian Research, Vol. 108, No. 3, June 1, pp. 319-33.IndiaGeophysics - paleomagnetics
DS1987-0168
1987
Blusson, S.L.Dummett, H.T., Fipke, C.E., Blusson, S.L.Diamond exploration in the North American Cordillerain: Geoexpo/86, A.E.G. publ, pp. 168-176British ColumbiaDiatremes
DS1998-0134
1998
Blusson, S.L.Blusson, S.L.Key steps to discovery of the Slave Craton diamond field, Northwest TerritoriesPathways '98 extended abstracts, p. 25. abstractNorthwest TerritoriesExploration - brief
DS2001-1086
2001
BlusztajnSkovgaard, A.C., Storey, M., Baker, Blusztajn, HartOsmium oxygen isotopic evidence for a recycled and strongly depleted component in the Iceland mantle plumeEarth and Planetary Science Letters, Vol. 194, No. 1-2, pp. 259-75.IcelandPlume, Geochronology
DS1994-0173
1994
Blusztajn, J.Blusztajn, J., Shimizu, N.The trace element variations in clinopyroxenes from spinel peridotite xenoliths from Western Victoria.Chemical Geology, Vol. 111, No. 1-4, January 5, pp. 227-244.GlobalXenoliths
DS1995-0766
1995
Blusztajn, J.Hart, S.R., Blusztajn, J., Craddock, C.Cenozoic volcanism in Antarctica: Jones Mountains and Peter I IslandGeochimica et Cosmochimica Acta, Vol. 59, No. 16, August 1, pp. 3379-88.Antarcticavolcanism., Alkaline rocks
DS2002-0174
2002
Blusztajn, J.Blusztajn, J., Hegner, E.Osmium isotope systematics of melilitites from the Tertiary Central European Volcanic province in SW Germany.Chemical geology, Vol. 189, 1-2, pp. 91-103.GermanyMelilitites, Geochronology
DS2003-0974
2003
Blusztajn, J.Moreira, M., Blusztajn, J., Curtice, J., Hart, S., Dick, H., KurzHe and Ne isotopes in oceanic crust: implications for noble gas recycling in the mantleEarth and Planetary Science Letters, Vol. 216, 4, pp. 635-43.MantleGeochronology
DS200412-1365
2003
Blusztajn, J.Moreira, M., Blusztajn, J., Curtice, J., Hart, S., Dick, H., KurzHe and Ne isotopes in oceanic crust: implications for noble gas recycling in the mantle.Earth and Planetary Science Letters, Vol. 216, 4, pp. 635-43.MantleGeochronology
DS200612-1557
2006
Blusztajn, J.Xu, Y.G., Blusztajn, J., Ma, J.L., Hart, S.R.In searching for old lithospheric relict beneath North Chin a Craton: Sr Nd Os isotopic composition of peridotite xenoliths from Yangyuan.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 3. abstract only.ChinaGeochronology
DS200812-1284
2008
Blusztajn, J.Xu, Y-G., Blusztajn, J., Ma, J-L., Suzuki, K., Liu, J.F., Hart, S.R.Late Archean to Early Proterozoic lithospheric mantle beneath the western North Chin a craton: Sr Nd Os isotopes of peridotite xenoliths from Yangyuan and FansiLithos, Vol. 102, 3-4, pp.25-42.ChinaGeochronology
DS201112-0510
2011
Blusztajn, J.Kelemen, P.B., Maiter, J., Sireil, E.E., Rudge, J.F., Curry, W.B., Blusztajn, J.Rates and mechanisms of mineral carbonation in peridotite: natural processes and recipes for enhanced, in situ CO2 capture and storage.Annual Review of Earth and Planetary Sciences, Vol. 39, pp. 545-576.MantleMineral carbonation
DS1991-0133
1991
Bluth, G.J.Bluth, G.J., Kump, L.R.Phanerozoic paleogeologyAmerican Journal of Science, Vol. 291, March pp. 284-308GlobalGeochemical cycles, Paleogeography
DS2002-0175
2002
Blyuman, B.A.Blyuman, B.A.Possibility of the impact paragenesis of diamond bearing eclogites with gray gneiss and basalt komatiite complexes.Doklady Earth Sciences, Vol. 384,4,pp.409-11.GlobalPetrology - eclogites
DS2003-0123
2003
Blyuman, B.A.Blyuman, B.A.Solar helium and neon in diamonds and basalts of plumes and hot spots: possible timingGeochemistry International, Vol. 41, 3, pp. 305-8.MantleGenesis
DS200412-0170
2004
Blyuman, B.A.Blyuman, B.A.Lithosphere and geodynamics at the 2.5 Ga boundary.Doklady Earth Sciences, Vol. 394, 1, Jan-Feb. pp. 1-4.MantleTectonics
DS200412-0171
2003
Blyuman, B.A.Blyuman, B.A.Solar helium and neon in diamonds and basalts of plumes and hot spots: possible timing and genesis of heterogeneity in the lowerGeochemistry International, Vol. 41, 3, pp. 305-8.MantleGenesis
DS201212-0460
2012
Bmbi, A.C.J.M.Melgarejo, J.C., Costanzo, A., Bmbi, A.C.J.M., Goncalves, A.O., Neto, A.B.Subsolidus processes as a key factor on the distribution of Nb species in plutonic carbonatites: the Tchivira case, Angola.Lithos, Vol. 152, pp. 187-201.Africa, AngolaCarbonatite
DS1991-0134
1991
BMR AustraliaBMR AustraliaKalimantan geological mapBmr Geology And Geophysics, 1: 1 million full colour $ 50.00 plus $ 15.00 airmailGlobalGeology, Map
DS1991-0135
1991
BMR.BMR.Regolith database handbookBmr., $45.00 inc. overseas chargesAustraliaComputer, Program -RTMAP regolith database
DS200412-1891
2004
BNayak, S.S.Sridhar, M., Chowdhary, V.S., BNayak, S.S., Augustine, P.F.Discovery of kimberlite pipes in Gadwal area, Mahbubnagar District, Andhra Pradesh.Journal of Geological Society of India, Vol. 63, 1, pp. 95-99.India, Andhra PradeshKimberlite
DS2002-0894
2002
BnyKouzmanov, K., Bailly, L., Ramboz, C., Rouer, O., BnyMorphology, origin and infrared microthermometry of fluid inclusions in pyrite from Radka epithermal copperMineralium deposita, BulgariaCopper, gold, geochronology, Deposit - Radka, Srednogorie zone
DS201902-0262
2018
Bo, T.Bo, T., Katz, R.F., Shorttle, O., Rudge, J.F.The melting column as a filter of mantle trace element heterogeneity.Geochemistry, Geophysics, Geosystems, Vol. 19, 12, pp. 4694-4721.Mantlemelting

Abstract: Basaltic lavas, created by melting the convecting mantle, show variability of concentration of trace element that are correlated with their affinity for the liquid phase during melting. The observed variability in lavas and melt inclusions carries information about heterogeneity in the mantle. The difficulty is to disentangle the contributions of source heterogeneity (i.e., spatial variability of mantle composition before melting) and process heterogeneity (i.e., spatial and temporal variability in melt transport). Here we develop an end?member model of the source heterogeneity and show that it is inadequate to explain observations.
DS1960-0794
1967
Boadu, M.K.Boadu, M.K.The Diamond Industry of Oda District with Special Reference to its Socio-economic Effects.Thesis, Winneba Advanced Teacher Training College., Ghana, West AfricaSociology, History
DS1988-0185
1988
Boak, J.L.Dymek, R.F., Boak, J.L., Brothers, S.C.Titanium chondrite- and titaium clinohumite-bearing metadunite from the3800 Ma Usua supracrustal belt, west Greenland:chemistry, petrology andoriginAmerican Mineralogist, Vol. 73, No. 5-6, May-June pp. 547-558GreenlandBlank
DS201809-2083
2018
Boallaran, T.B.Schulze, K., Marquardt, H., Kawazoe, T., Boallaran, T.B., McCammon, C., Koch-Muller, M., Kurnosov, A., Marquardt, K.Seismically invisable water in Earth's transition zone?Earth and Planetary Science Letters, Vol. 498, pp. 9-16.Mantlewater

Abstract: Ringwoodite, the dominant mineral at depths between 520 km and 660 km, can store up to 2-3 wt.% of water in its crystal structure, making the Earth's transition zone a plausible water reservoir that plays a central role in Earth's deep water cycle. Experiments show that hydration of ringwoodite significantly reduces elastic wave velocities at room pressure, but the effect of pressure remains poorly constrained. Here, a novel experimental setup enables a direct quantification of the effect of hydration on ringwoodite single-crystal elasticity and density at pressures of the Earth's transition zone and high temperatures. Our data show that the hydration-induced reduction of seismic velocities almost vanishes at conditions of the transition zone. Seismic data thus agree with a wide range of water contents in the transition zone.
DS201012-0021
2010
Boamah, D.Asiedu, D.K., Dampare, S.B., Samoah Sakyi, P., Boamah, D.Major and trace element geochemistry of kimberlitic rocks in the Akwatia area of the Birim Diamondiferous field, southwest Ghana.African Journal of Science and Technology, Science and Engineering series, Vol. 8, 2, pp. 81-91.Africa, GhanaDeposit - Akwatia
DS200812-0120
2008
Boanadiman, C.Boanadiman, C., Coltari, M., Duggen, S., Paludetti, L., Siena,F.,Thirwall, M.F., Upton, BGJ.Paleozoic subduction related and kimberlite or carbonatite metasomatism in the Scottish lithospheric mantle.Geological Society of London, Special Publications no. 293, pp. 303-334.Europe, ScotlandSubduction
DS1997-0639
1997
Boardman, J.W.Kruse, F.A., Boardman, J.W.Characterization and mapping of kimberlites and related diatremes using airborne visible/ Infrared imaging...Twelfth Geologic Remote Sensing, Nov. 17th., AbstractsUtah, Colorado, WyomingGeophysics - remote sensing, Spectrometer
DS201903-0524
2000
Boardman, J.W.Kruse, F.A., Boardman, J.W.Characterization and mapping of kimberlites and related diatremes using hyperspectral remote sensing.IEEE.org * note date , pp. 299-304.United States, Colorado, Wyomingdeposit - Kelsey Lake

Abstract: Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) and commercially-available HyMap hyperspectral data were used to study the occurrence and mineralogical characteristics of limberlite diatremes in the State-Line district of Colorado/Wyoming. A mosaic of five flightlines of AVIRIS data acquired during 1996 with 20-m resolution is being used to locate and characterize the kimberlite diatremes. Higher spatial resolution data (1.6 m AVIRIS and 4m HyMap acquired in 1998 and 1999, respectively) are being used to map additional detail. Poor exposures, vegetation cover, and weathering, however, make identification of characteristic kimberlite minerals difficult except where exposed by mining. Minerals identified in the district using the hyperspectral data include calcite, dolomite, illite/muscovite, and serpentine (principally antigorite), however, most spectral signatures are dominated by both green and dry vegetation. The goal of this work is to determine methods for characterizing subtle mineralogic changes associated with kimberlites as a guide to exploration in a variety of geologic terrains.
DS200912-0057
2009
Boari, E.Boari, E., Tommasini, S., Laurenzi, M.A., Conticelli, S.Transition from ultrapotassic kamafugitic to sub-alkaline magmas: Sr Nd and Pb isotope, trace element and 40Ar 39Ar age dat a from the Middle LatinJournal of Petrology, Vol. 50,no. 7,. pp. 1327-1357.Europe, ItalyKamafugite
DS1993-0890
1993
Boatikov, D.A.Lazko, E.E., Sharkov, E.V., Boatikov, D.A.Mantle substrates, their geochemical typization and role in the subcrust magma formation. (Russian)Geochemistry International (Geokhimiya), (Russian), No. 2, February pp. 165-188Russia, Commonwealth of Independent States (CIS)Geochemistry, Mantle, crust
DS1992-0135
1992
Boberg, B.Boberg, B.Diamond and gold exploration in Liberia, West AfricaBoberg Geotech International Ltd. November 1992, 1p. abstract talk given at Colorado School of MinesGlobalBrief overview, Geochemistry
DS1996-0142
1996
Boberg, B.Boberg, B.Tanzania: restructured and rebornProspectors and Developers Association of Canada (PDAC) Annual Meeting, p. 68. abstract.TanzaniaOverview, Political, legal, resources
DS200612-0142
2006
Boberg, B.Boberg, B.Depository of country databases.... maps and reports, files.africaminerals.com, AfricaMaps, reports, information sources
DS1989-0129
1989
Bobervich, B.Bobervich, B.Plotting trends: industry OEMs key in on electrostatic plotting optionsGeobyte, Vol. 4, No. 6, December pp. 8, 10-11GlobalComputer, Plotting trends
DS1975-0656
1977
Bobolev, N.V.Yefimova, E.S., Bobolev, N.V.Abundance of Crystalline Inclusions in Yakutian DiamondsDoklady Academy of Sciences, Vol. 237, No. 6, pp. 231-4.Russia, Yakutia, SiberiaDiamond Morphology
DS1960-0122
1961
Bobrievich, A P.Bobrievich, A P.Certain Dat a on the Geological Status of Siberian KimberliteAkad. Nauk Sssr Trudy Yakut. Fil., No. 6RussiaBlank
DS1950-0317
1957
Bobrievich, A.P.Bobrievich, A.P.The Petrography of the Ultrabasic Inclusions in the Kimberlites of Eastern Siberia.Razv. I Okhr. Nedr., No. 1, PP. 6-12.RussiaBlank
DS1950-0318
1957
Bobrievich, A.P.Bobrievich, A.P.Moissanite in the Kimberlite of Eastern Siberian PlatformDoklady Academy of Science USSR, Earth Science Section., Vol. LL5, No. 6, PP. LL73-LL76.RussiaBlank
DS1950-0319
1957
Bobrievich, A.P.Bobrievich, A.P., Khar'kiv, A.D., Pozidaeva, V.F.The Geological Features of the Mir KimberliteNauchNo. Tetch. Info. Bulletin., No. 3.RussiaBlank
DS1950-0320
1957
Bobrievich, A.P.Bobrievich, A.P., Kuryleva, N.A.Petrography of the Siberian KimberlitesAkad. Nauk Sssr Ser. Geol., No. 4.RussiaBlank
DS1950-0459
1959
Bobrievich, A.P.Bobrievich, A.P., et al.A Monographic Description of Deposits of Yakutia; Includes Section on Geology and Placer Occurrences, Mineralogy of Diamondiferous Kimberlite Analyses.Min. Geol. I Okhr. Nedr., 527P.RussiaBlank
DS1960-0018
1960
Bobrievich, A.P.Bobrievich, A.P., et al.The Petrography of the Kimberlites in the Basins of the Rivers Olenek and Muna on the Siberian Platform with Iron Ore In the Zone Angara-ilim.Mater. Po Geol. I Polez. Iskop. Sssr., No. 3, PP. 54-L24.RussiaBlank
DS1960-0019
1960
Bobrievich, A.P.Bobrievich, A.P., Kryativ, B.M., Shchukin, V.N.Certain Dat a on the Geology and Petrography of the Siberiankimberlite.Akad. Nauk Sssr Ser. Geol., No. 6.RussiaBlank
DS1960-0020
1960
Bobrievich, A.P.Bobrievich, A.P., Smirnov, G.I., Sobolev, V.S.The Mineralogy of Xenoliths of a Grossularite Pyroxene Kyanite Rock from the Kimberlites of Yakutia.Geol. Series, Ussr, American Geological Institute Translation., No. 3, PP. 18-24.RussiaKimberlite
DS1960-0021
1960
Bobrievich, A.P.Bobrievich, A.P., Smirnov, G.I., Sobolev, V.S.Eclogite Xenoliths With Diamond InclusionsDoklady Academy of Science USSR, Earth Science Section., Vol. 126, No. 1-6, PP. 581-583.RussiaKimberlite
DS1960-0123
1961
Bobrievich, A.P.Bobrievich, A.P.Kimberlite Formation of the Northern Part of the Siberian Platform.Petrografiya Votochnoi Sibtri, No. 1.RussiaBlank
DS1960-0218
1962
Bobrievich, A.P.Bobrievich, A.P., Sobolev, V.S.Kimberlite Formations of the North Part of the Siberian Platform.In: The Petrography of The Ussr, PT. L, PP. 3L4-3L6.RussiaBlank
DS1960-0426
1964
Bobrievich, A.P.Bobrievich, A.P., Ilupin, P., et al.Petrography and Mineralogy of the Kimberlitic Rocks of Yakutia.Moscow: Nedra., 190P. International GEOL. CONGRES., DOKL. SOV. GEOL., No. 7, PP. 8RussiaBlank
DS1985-0369
1985
Bobrievich, A.P.Krivoshlyk, I.N., Bobrievich, A.P.Secondary (binary) Liquifaction of Kimberlitic Magma.(russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 280, No. 6, pp. 1414-1418RussiaPetrology
DS1985-0370
1985
Bobrievich, A.P.Krivoshlyk, I.N., Bobrievich, A.P.The Repeated (double) Liquation in Kimberlite MagmaDoklady Academy of Sciences AKAD. NAUK SSSR., Vol. 280, No. 6, PP. 1414-1418.RussiaBlank
DS1995-0292
1995
Bobrievich, A.P.Chaska, A.I., Bobrievich, A.P., Zaritski, A.I., et al.Kimberlite magmatism of the UkraineProceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 104-105.UKrainePriazovski Near Azov, North Volyn, Petrovskoe, Nadiya, Yuzhnaya, Novolaspinskaya
DS1950-0321
1957
Bobrievitch, A.P.Bobrievitch, A.P., Burov, A.P.Diamonds of Siberia. Translation of Almazy Siberii, 1957London: Industrial Diamond Information Bureau, 219P.Russia, Siberia, YakutiaGeology
DS1960-0427
1964
Bobrievitch, A.P.Bobrievitch, A.P., et al.Petrology and Mineralogy of Kimberlite Rocks in YakutiaMoscow: Nedra., RussiaJanlib, Kimberlite, Kimberley
DS1960-1073
1969
Bobriyevich, A.P.Bobriyevich, A.P.General Problems of the Petrology of KimberlitesGeologii i Geofiziki, No. , PP. 208-215.RussiaBlank
DS1975-0034
1975
Bobriyevich, A.P.Bobriyevich, A.P., Golovko, M.M., et al.Diamond Find in Upper Carboniferous Clastic Rocks of the Northwestern Donbas.Doklady Academy of Science USSR, Earth Science Section., Vol. 222, No. 1-6, PP. 118-120.RussiaKimberlite
DS1983-0379
1983
Bobriyevich, A.P.Krivoshlyk, I.N., Bobriyevich, A.P.Spherules of Immiscible Carbonatite in KimberliteDoklady Academy of Sciences ACAD. NAUK USSR EARTH SCI. SECTION., Vol. 261, No. 1-6, PP. 121-123.RussiaPetrography
DS1984-0433
1984
Bobriyevich, A.P.Krivoshlyk, I.N., Bobriyevich, A.P.Typomorphic pecularities of carbonate serpentine paragenesis in kimberliterocks.(Russian)Mineral Sbornik (L'Vov), (Russian), Vol. 38, No. 1, pp. 7-11RussiaCarbonate
DS1985-0371
1985
Bobriyevich, A.P.Krivoshlyk, I.N., Bobriyevich, A.P.A Possible Mode of Kimberlite Pipe Formation.(russian)Mineral. Sbornik (L'Vov), (Russian), Vol. 39, No. 1, pp. 3-7RussiaBlank
DS1986-0465
1986
Bobriyevich, A.P.Krivoshlyk, I.N., Bobriyevich, A.P.Repeated seperation of kimberlite magma into immiscible meltsDoklady Academy of Science USSR, Earth Science Section, Vol. 280, No. 1-6, pp. 122-125RussiaMagma
DS1987-0377
1987
Bobriyevich, A.P.Krivoshlyk, I.N., Bobriyevich, A.P.Some conceptson the hydraulic hammer hypothesis inkimberlitepipes.(Russian)Mineral. Sbornik (L'Vov), (Russian), Vol. 41, No. 2, pp. 48-54RussiaPetrology, Diatremes
DS1989-0130
1989
Bobriyevich, A.P.Bobriyevich, A.P.General problems of the petrology of kimberlite.(Russian)In: Problems of Petrology and Genetic Mineralogy, IZD. Nauka, Vol. 1, pp. 208-215RussiaPetrology, Kimberlites
DS200712-0079
2007
Bobrov, A.Bindi, L., Bobrov, A., Litvin, Y.A.in corporation of Fe3+ in phase -X, A2xM2Si207Hx, a potential high pressure K-rich hydrous silicate in the mantle.Mineralogical Magazine, Vol. 71, 3, pp. 265-272.MantleUHP
DS201012-0060
2010
Bobrov, A.Bobrov, A., Dymshits, A., Litvin, Yu., Litasov, K., Shatskiy, A., Ohtani, E.Sodium bearing majorite garnet: nature and experimental aspects.International Mineralogical Association meeting August Budapest, abstract p. 148.Russia, Timan, South America, Brazil, ChinaUHP
DS201012-0815
2010
Bobrov, A.Vasiliev, P., Okoemova, V., Litvin, Y., Bobrov, A.Experimental study of syngenetic relations of diamond and its inclusions in the heterogeneous system eclogite carbonatite sulfide diamond at 7.0 GPa.International Mineralogical Association meeting August Budapest, abstract p. 179.TechnologyDiamond genesis
DS201312-0545
2012
Bobrov, A.Litvin, Yu., Vasilev, P., Bobrov, A., Okoemova, V., Kuzyura, A.Parental media of natural diamonds and primary mineral inclusions in them: evidence from physicochemical experiment.Geochemistry International, Vol. 50, 9, pp. 726-759.TechnologyDiamonds inclusions
DS200812-1083
2008
Bobrov, A.A.Smininsky, K.Zh., Gladkov, A.S., Radziminovich, Ya.B., Cheremnykh, A.V., Bobrov, A.A.Regularities of manifestation of active faults and seismicity in the southern part of the Siberian craton.Doklady Earth Sciences, Vol. 422, 1, October pp. 1068-1972.Russia, SiberiaGeophysics - seismics
DS201806-1211
2018
Bobrov, A.M.Baranov, A.A., Bobrov, A.M.Crustal structure and properties of Archean cratons of Gondwanaland: similarity and difference.Russian Geology and Geophysics, Vol. 59, pp. 512-524.Africa, Australia, South America, Indiacraton

Abstract: This is a synopsis of available data the on crustal structure and properties of thirteen Archean cratons of Gondwanaland (the cratons of Africa, Australia, Antarctica, South America, and the Indian subcontinent). The data include estimates of surface area, rock age and lithology, Moho depth, thickness of lithosphere and sediments, as well as elevations, all summarized in a table. The cratons differ in size from 0.05 x 106 km2 (Napier craton) to 4 x 106 km2 (Congo craton) and span almost the entire Archean period from 3.8 to 2.5 Ga. Sediments are mostly thin, though reach 7 km in the Congo and West African cratons. Elevations above sea level are from 0 to 2 km; some relatively highland cratons (Kaapvaal, Zimbabwe, and Tanzanian) rise to more than 1 km. On the basis of regional seismic data, the Moho map for cratons has been improved. The Moho diagrams for each craton are constructed. The analysis of the available new data shows that the average Moho depth varies from 33 to 44 km: Pilbara (33 km), Grunehogna (35 km), Sao Francisco (36 km), Yilgarn (37 km), Dharwar (38 km), Tanzanian (39 km), Zimbabwe (39 km), Kaapvaal (40 km), Gawler (40 km), Napier (40 km), West Africa (40 km), Congo (42 km), and Amazon (44 km) cratons. The Moho depth within the cratons is less uniform than it was assumed before: from 28 to 52 km. The new results differ significantly from the earlier inference of a relatively flat Moho geometry beneath Archean cratons. According to the new data, early and middle Archean undeformed crust is characterized by a shallow Moho depth (28-38 km), while late Archean or deformed crust may be as thick as 52 km.
DS1996-0143
1996
Bobrov, A.V.Bobrov, A.V.Mineral associations of inclusions in garnets from the kimberlitic pipesMir and Sytykanskaya (Yakutia).International Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 382.Russia, YakutiaGarnet inclusions, Deposit -Mir, Sytykanskaya
DS1996-0144
1996
Bobrov, A.V.Bobrov, A.V., Garanin, V.K.Mineralogy and genesis of pyrope peridotite zonal modulesMoscow University of Geol. Bulletin., Vol. 51, No. 1, pp. 27-36.RussiaPeridotite
DS1998-0937
1998
Bobrov, A.V.Marakushev, A.A., Bobrov, A.V.Specific features of crystallization of eclogite magmas at the diamond facies depths.Doklady Academy of Sciences, ol. 358, No. 1, pp. 142-5.RussiaEclogite, Crystallography
DS1998-0938
1998
Bobrov, A.V.Marakushev, A.A., Bobrov, A.V.Crystallization of eclogite and pyroxenite magmas in diamond depth facies:evidence from garnet-clinopyrox.7th International Kimberlite Conference Abstract, pp. 546-8.Russia, YakutiaDiamond inclusions, Deposit - Udachnaya
DS2002-0176
2002
Bobrov, A.V.Bobrov, A.V., Litvin, Y.A., Divaev, F.K.Phase relations in carbonate silicate rocks from diatremes of the Chagatai ComplexDoklady, Vol.383A,3,March-April,pp. 267-70.RussiaPetrology, Deposit - Chagatai complex
DS2002-0953
2002
Bobrov, A.V.Litvin, Y.A., Butvina, V.G., Bobrov, A.V., Zharikov, V.The first synthesis of diamond in sulphide carbon systems: the role of sulphides in diamond genesis.Doklady, Vol.382, 1, Jan-Feb.pp. 40-3.GlobalDiamond - petrology
DS2002-0954
2002
Bobrov, A.V.Litvin, Y.A., Butvina, V.G., Bobrov, A.V., Zharikov, V.A.The first synthesis of diamond in sulphide carbon systems: the role of sulphides inDoklady Earth Sciences, Vol.382,1,pp.40-43.GlobalDiamond - morphology
DS2003-0124
2003
Bobrov, A.V.Bobrov, A.V., Litvin, Yu., Butvina, V.Diamond synthesis in sulfide medium at 6-8 Gpa: application to natural data8ikc, Www.venuewest.com/8ikc/program.htm, Session 3, POSTER abstractGlobalDiamonds - inclusions
DS2003-0125
2003
Bobrov, A.V.Bobrov, A.V., Verichev, E.M., Garanin, V.K., Garanin, K.V., Kudryavtseva, G.P.Xenoliths of mantle metamorphic rocks from the Diamondiferous V. Grib pipe (8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, POSTER abstractRussia, ArkangelskDeposit - Grib
DS2003-1014
2003
Bobrov, A.V.Nikiforava, A., Bobrov, A.V., Spetsius, V.Z.Garnet clinopyroxene assemblage of mantle rocks from the Obnazhennaya kimberlite8ikc, Www.venuewest.com/8ikc/program.htm, Session 2, POSTER abstractRussia, YakutiaEclogites and Diamonds, Deposit - Obnazhennaya
DS200412-0172
2004
Bobrov, A.V.Bobrov, A.V., Litvin, Y.A., Divaev, F.K.Phase relations and diamond synthesis in the carbonate silicate rocks of the Chagatai Complex, western Uzbekistan: results of exGeochemistry International, Vol. 42, 1, pp. 39-48.Russia, UzbekistanDiamond genesis
DS200412-0173
2003
Bobrov, A.V.Bobrov, A.V., Verichev, E.M., Garanin, V.K., Garanin, K.V., Kudryavtseva, G.P.Xenoliths of mantle metamorphic rocks from the Diamondiferous V. Grib pipe ( Arkangelsk province): petrology and genetic aspects8 IKC Program, Session 6, POSTER abstractRussia, Kola Peninsula, ArchangelMantle petrology Deposit - Grib
DS200512-0096
2005
Bobrov, A.V.Bobrov, A.V., Verichev, E.M., Garanin, V.K., Kudryavtseva, G.P.The first find of kyanite eclogite in the V. Grib kimberlite pipe ( Arkangelsk Province).Doklady Earth Sciences, Vol. 402, 4, pp. 628-631.Russia, Kola Peninsula, ArchangelEclogite
DS200512-0685
2003
Bobrov, A.V.Marakushev, A.A., Lonkan, S., Bobrov, A.V., Hengweng, Z., Fu, L.Evolution of the SuLu eclogite ultramafic foldbelt in East China.Moscow University Geology Bulletin, Vol. 58, 6, pp. 33-46.ChinaUHP
DS200612-0864
2005
Bobrov, A.V.Marakushev, A.A., Bobrov, A.V.Problems of primary magma and the depths of Diamondiferous magmatism.Doklady Earth Sciences, Vol. 403A, 6, pp. 901-904.MantleMagmatism
DS200812-0671
2008
Bobrov, A.V.Litvin, Yu.A., Bobrov, A.V.Experimental study of diamond crystallization in carbonate peridotite melts at 8.5 GPa.Doklady Earth Sciences, Vol. 422, 1 Oct. pp. 1167-1171.TechnologyMelting
DS200912-0058
2009
Bobrov, A.V.Bobrov, A.V., Spivak, A.V., Divaev, F.K., Dymshits, A.M., Litvin, Yu.A.High pressure melting relations of diamond forming carbonatites: formation of syngenetic peridotitic and eclogitic minerals ( experiments at 7.0 and 8.5 GPa).alkaline09.narod.ru ENGLISH, May 10, 2p. abstractTechnologyMelting
DS200912-0195
2009
Bobrov, A.V.Dymshits, A.M., Bobrov, A.V., Litvin, Yu.A.Experimental study of formation of Na rich majorite garnet in the context of diamond deep mantle genesis.alkaline09.narod.ru ENGLISH, May 10, 2p. abstractTechnologyDiamond stability
DS200912-0443
2009
Bobrov, A.V.Litvin, Yu.A., Bobrov, A.V., Kuzyura, A.V., Spivak, A.V., Litvin, Y.Yu., Butvina, V.G.Mantle carbonatite magma in diamond genesis.Goldschmidt Conference 2009, p. A774 Abstract.MantleMelting
DS200912-0448
2009
Bobrov, A.V.Livin, Yu.AQ., Spivak, A.V., Solopova, N.A., Litvin, V.Yu., Bobrov, A.V.Physicochemical factors of diamond and graphite formation in carbonatite melts on experimental grounds.alkaline09.narod.ru ENGLISH, May 10, 2p. abstractTechnologyExperimental melt
DS201012-0061
2009
Bobrov, A.V.Bobrov, A.V., Dymshits, A.M., Litvin, Yu.Conditions of magmatic crystallization of Na bearing majoritic garnets in the Earth mantle: evidence from experimental and natural data.Geochemistry International, Vol. 47, 10, Oct. pp. 951-965.MantleMagmatism
DS201012-0062
2009
Bobrov, A.V.Bobrov, A.V., Litvin, Yu.A.Peridotite eclogite carbonatite systems at 7.0-8.5 GPa: concentration barrier of diamond nucleation and syngenesis of the silicate and carbonate inclusions.Russian Geology and Geophysics, Vol. 50, 12, pp. 1221-1233.MantleDiamond genesis
DS201112-0096
2011
Bobrov, A.V.Bobrov, A.V., Litvin, Yu.A., Dymshits, A.M.Experimental studies of carbonatite silicate systems and problem of the diamond formation.Moscow, GEOS, IN RUSSIAN, 208p. IN RUSSIANTechnologyBook - reference only
DS201112-0610
2011
Bobrov, A.V.Litvin, Yu.A., Vasiliev, P.G., Bobrov, A.V., Okoyomova, V.Yu., Kuzyura, A.V.Parental media for diamonds and primary inclusions by evidence of physicochemical experiment.Vestnik ONZ RAN *** in english, 4p. IN ENGLISHMantleMantle melting - carbonatite genesis of diamond
DS201112-0970
2011
Bobrov, A.V.Sirotkina, E.A., Bobrov, A.V., Garanin, V.K., Bovkun, A.V., Shkurskii, B.B., Korost, D.V.Pyroxene and olivine exsolution textures in majoritic garnets from the Mir kimberlitic pipe, Yakutia.Goldschmidt Conference 2011, abstract p.1885.RussiaMir
DS201212-0075
2011
Bobrov, A.V.Bobrov, A.V., Litvin, Yu.A.Mineral equilibration temperatures of diamond forming carbonatite silicate systems.Geochemistry International, Vol. 49, 13, pp. 1267-1363.TechnologyMelting
DS201212-0076
2012
Bobrov, A.V.Bobrov, A.V., Llitvin, Y.A., Ismalilova, L.S.Diamond forming efficiency of chloride-silicate carbonate melts: the role of chlorides,10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractTechnologyDiamond genesis
DS201212-0077
2012
Bobrov, A.V.Bobrov, A.V., Sirotkina, E.A., Garanin, V.K., Bovkun, A.V., Korost, D.V., Shkurski, B.B.Majoritic garnets with exsolution textures from the Mir kimberlitic pipe ( Yakutia)Doklady Earth Sciences, Vol. 444, 1, pp. 574-578.Russia, YakutiaDeposit - Mir
DS201212-0178
2012
Bobrov, A.V.Dymshits, A.M., Bindi, L., Bobrov, A.V., Litasov, K.D., Shatskiy, A.F., Ohtani, E., Litvin, Yu.A.Sodium majorite and its pyrope solid solutions high pressure experiment and crystal chemical implications.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractTechnologyMineral Chemistry
DS201212-0659
2012
Bobrov, A.V.Sirotkina, E.A., Bobrov, A.V., Garanin, V.K., Bovkin, A.V., Shkurski, B.B., Korost, D.V.Exsolution textures in majoritic garnets from the Mir kimberlite pipe, Yakutia, Russia.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, YakutiaDeposit - Mir
DS201603-0366
2016
Bobrov, A.V.Bindi, L., Tamarova, A., Bobrov, A.V., Sirotkina, E.A., Tschauner, O., Walter, M.J., Irifune, T.in corporation of high amounts of Na in ringwoodite: possible implications for transport of alkali into lower mantle.American Mineralogist, Vol. 101, pp. 483-486.MantleRingwoodite
DS201708-1601
2017
Bobrov, A.V.Bobrov, A.V.Sodium-bearing phases in the transition zone and uppermost lower mantle: experimental and natural data.11th. International Kimberlite Conference, PosterMantlemineralogy
DS201709-2053
2017
Bobrov, A.V.Sirotina, E.A., Bobrov, A.V.Minerals of chromium in the Earth's mantle. ***RUSSGeos Moscow, 159.p pdf availableMantlechromium
DS201711-2529
2017
Bobrov, A.V.Tamarova, A.P., Bobrov, A.V., Sirotkina, E.A., Bindi, L., Irifune, T.Melting of model pyrolite under the conditions of the transition zone.Proceedings of XXXIV held Aug. 4-9. Perchuk International School of Earth Sciences, At Miass, Russia, 1p. AbstractMantlemelting
DS201802-0222
2017
Bobrov, A.V.Bobrov, A.V.Crystal inclusions in diamond - a key to understanding of the Earth's mantle mineralogy. ***IN RUSStarosin, V.I. (ed) Problems of the mineralogy, economic geology and mineral resources. MAKS Press, Moscow *** IN RUS, pp. 175-196.Mantlediamond inclusions
DS201802-0265
2018
Bobrov, A.V.Sirotkina, E.A., Bobrov, A.V., Bindi, L., Irifune, T.Chromium bearing phases in the Earth's mantle: experiments in the Mg2SiO4 MgCr2O4 system at 10-24 Gpa and 1600C.American Mineralogist, Vol. 103, pp. 151-160.Mantlechromites

Abstract: Phase relations in the system Mg2SiO4-MgCr2O4 were studied at 10-24 GPa and 1600°C using a high-pressure Kawai-type multi-anvil apparatus. We investigated the full range of starting compositions for the forsterite-magnesiochromite system to derive a P-X phase diagram and synthesize chromium-bearing phases, such as garnet, wadsleyite, ringwoodite, and bridgmanite of a wide compositional range. Samples synthesized at 10 GPa contain olivine with small chromium content and magnesiochromite. Mg2SiO4 wadsleyite is characterized by the pressure-dependent higher chromium solubility (up to 7.4 wt% Cr2O3). The maximal solubility of chromium in ringwoodite in the studied system (~18.5 wt% Cr2O3) was detected at P = 23 GPa, which is close to the upper boundary of the ringwoodite stability. Addition of chromium to the system moves the boundaries of olivine/wadsleyite and wadsleyite/ring-woodite phase transformations to lower pressures. Our experiments simulate Cr-rich phase assemblages found as inclusions in diamonds, mantle xenoliths, and UHP podiform chromitites.
DS201809-1996
2018
Bobrov, A.V.Bobrov, A.V., Tamarova, A.P., Sirotkina, E.A., Zhang, G.S., Irifune, T.Interphase partitioning of minor elements in the transition zone and uppermost lower mantle.Goldschmidt Conference, 1p. AbstractMantlediamond inclusions

Abstract: Interphase partitioning of minor elements was studied experimentally upon partial melting of model pyrolite [1] with addition of 2 wt % H2O, 10, and 15 wt % of multicomponent carbonate at 22-24 GPa and 1300-2200°C. The concentrations of minor elements were analyzed on an Agilent 7500a mass spectrometer. Phase associations included quenched melt (L), bridgmanite (Brd), CaSiO3- perovskite (CaPrv), ringwoodite (Rwd), ferropericlase (Fp), and majoritic garnet (Maj). The sequence of phase assemblages in our runs is consistent to that reported in [2] for melting of anhydrous pyrolite at 24 GPa: Fp+L, Fp+Maj+Brd(Rwd)+L, Fp+Maj+Brd(Rwd)+CaPrv. Most of minor elements, except for Sc, Cr, and Ni, are incompatible for Brd and show slight increase in partitioning coefficients from LREEs to HREEs in the H2O-bearing system. Pyrolite with carbonate is characterized by slightly higher LREE partitioning coefficients. Monovalent elements (Li, K, Cs, Rb), as well as Sr and Pb, are strongly incompatible for Brd in all systems. The similar features are observed for Fp enriched in HREEs and depleted in LREEs; all minor elements show redistribution into Fp with pressure. CaPrv is enriched in LREEs and depleted in HREEs. We applied the lattice strain model [3] for interpretation of the analytical data, which allowed us to study the behavior of minor elements as a function of P-T parameters. Our data and some previous results [4] were used for estimation of the composition of melts in equilibrium with inclusions in diamonds from the transition zone and lower mantle.
DS201809-2041
2018
Bobrov, A.V.Iskrina, A.V., Bobrov, A.V., Kriulina, G.Y., Zedgenizov, D.A., Garanin, V.K.Melt/fluid inclusions in diamonds from the Lomonosov deposit ( Arkangelsk kimberlite province).Goldschmidt Conference, 1p. AbstractRussia, Kola Peninsuladeposit - Lomonosov

Abstract: Melt/fluid inclusions in diamonds provide important evidence for mantle diamond-forming fluids or melts. By now, the major characteristics of the composition of microinclusions have been analyzed in diamonds from several kimberlite provinces and pipes worldwide [1-4]. Here we report the first data on the composition of parent diamondforming melts for diamonds from the Arkhangelsk kimberlite province. After the study of morphology, specialty of the internal structure, and distribution of microinclusions in diamonds, 10 single crystals were selected from the 31 diamonds of the representative collection. The studied crystals may be divided into two groups: cuboids and coated diamonds. The crystals have grayish yellow or dark gray colors and are almost nontransparent due to the high content of microinclusions. Polished slices of these diamonds were studied by IR-spectroscopy, which allowed us to calculate the content of nitrogen defects, as well as the content of water and carbonates in microinclusions. X-ray spectral analyses allowed to study the composition of fluid/melt microinclusions and showed that they were essentially carbonate-silicate with significant variations between these two end-members. All inclusions contain water, with the highest H2O/CO2 in highly siliceous inclusions. Unlike diamonds from Canada and South Africa [1, 2], the studied inclusions in diamionds from the Arkhangelsk province are almost free of chlorides. Comparison of the data obtained with the database on fliud/melt inclusions in diamonds worldwide shows similar of Arkhangelsk diamonds to some diamonds from Yakutia [3, 4], and the data obtained are the most similar to the composition of microinclusions in diamonds from the Internatsionalnaya pipe (Yakutia).
DS201910-2275
2019
Bobrov, A.V.Kriulina, G.Yu., Iskrina, A.V., Zedgenizov, D.A., Bobrov, A.V., Garanin, V.K.The compositional pecularities of microinclusions in diamonds from the Lomonosov deposit ( Arkangelsk Province).Geochemistry International, Vol. 57, 9, pp. 963-980.Russiadeposit - Lomonosov

Abstract: The data on the composition of microinclusions in diamonds from the Lomonosov deposits are reported for the first time. The studied diamonds include “coated” (n = 5) and cubic (n = 5) crystals. The estimated range of the degree of nitrogen aggregation in diamonds (4-39% B1) does not support their direct links with kimberlite magmatism; however, their short occurrence in the mantle at higher temperatures is probable as well. The composition of melt/fluid microinclusions in these samples varies from essentially carbonatitic to significantly silicate. It is shown that the contents of MgO, CaO, Na2O, Cl, and P2O5 decrease with increasing content of silicates and water. Different mechanisms of the generation and evolution of diamond-forming media are discussed to explain the observed variations.
DS202004-0537
2020
Bobrov, A.V.Tamarova, A.P., Marchenko, E.I., Bobrov, A.V., Eremin, N.N., Zinovera, N.G., Irifune, T., Hirata, T., Makino, Y.Interphase REE partitioning at the boundary between the Earth's transition zone and lower mantle: evidence from experiments and atomistic modeling.Minerals MDPI, Vol. 10, 10030262 14p. PdfMantleREE

Abstract: Trace elements play a significant role in interpretation of different processes in the deep Earth. However, the systematics of interphase rare-earth element (REE) partitioning under the conditions of the uppermost lower mantle are poorly understood. We performed high-pressure experiments to study the phase relations in key solid-phase reactions CaMgSi2O6 = CaSiO3-perovskite + MgSiO3-bridgmanite and (Mg,Fe)2SiO4-ringwoodite = (Mg,Fe)SiO3-bridgmanite + (Mg,Fe)O with addition of 1 wt % of REE oxides. Atomistic modeling was used to obtain more accurate quantitative estimates of the interphase REE partitioning and displayed the ideal model for the high-pressure minerals. HREE (Er, Tm, Yb, and Lu) are mostly accumulated in bridgmanite, while LREE are predominantly redistributed into CaSiO3. On the basis of the results of experiments and atomistic modeling, REE in bridgmanite are clearly divided into two groups (from La to Gd and from Gd to Lu). Interphase REE partition coefficients in solid-state reactions were calculated at 21.5 and 24 GPa for the first time. The new data are applicable for interpretation of the trace-element composition of the lower mantle inclusions in natural diamonds from kimberlite; the experimentally determined effect of pressure on the interphase (bridgmanite/CaSiO3-perovskite) REE partition coefficients can be a potential qualitative geobarometer for mineral inclusions in super-deep diamonds.
DS202006-0935
2020
Bobrov, A.V.Matrosova, E.A., Bobrov, A.V., Bindi, L., Pushcharovsky, D.Yu., Irifune, T.Titanium-rich phases in the Earth's transition zone and lower mantle: evidence from experiments in the system Mg)-Si)2-TiO2(+- Al2O3Lithos, Vol. 366-367, 14p. PdfMantlewebsterite, bridgmanite

Abstract: Phase relations in the MgSiO3-MgTiO3 and Mg3Al2Si3O12-MgTiO3 systems were studied at 10-24 GPa and 1600 °C using a high-pressure Kawai-type multianvil apparatus. We investigated the full range of starting compositions for the enstatite-geikielite system to derive a P-X phase diagram and synthesize titanium-bearing phases, such as olivine/wadsleyite, rutile, pyroxene, MgTiSi2O7 weberite, bridgmanite and MST-bridgmanite in a wide pressure range. Olivine and pyroxene in run products are characterized by a low titanium content (<0.6 and <0.3 wt% TiO2, respectively) whereas the content of TiO2 in wadsleyite reaches 2 wt% at 12 GPa. The concentration of Ti in MgTiSi2O7 weberite decreases with pressure from 52 wt% TiO2 at 14 GPa to 43 wt% TiO2 at 18 GPa. Two perovskite-type structures (MgSiO3 bridgmanite and Mg(Si,Ti)O3 bridgmanite) were detected in the studied system. MgSiO3 bridgmanite (Brd) is formed at a pressure of >20 GPa and characterized by significant titanium solubility (up to 13 wt% TiO2 at 24 GPa). Mg(Si,Ti)O3 perovskite is formed at a pressure of >17 GPa. The concentration of TiO2 in this phase varies from 29 wt% to 49 wt%. It was found that addition of Ti to the system moves the boundaries of Ol/Wad phase transformations to lower pressures. Addition of Al to the starting material allows us to simulate the composition of natural Ti-rich garnets and bridgmanites. It is important to note that garnet in the Prp-Gkl system is stable throughout a wide pressure range (10-24 GPa). Al incorporation does not affect the distribution of titanium between two types of bridgmanite. It is shown that high contents of Ti stabilize bridgmanite-like compounds at considerably lower pressure than that at the lower mantle/transition zone boundary. Our experiments simulate the composition of natural Ti-rich primary garnet found in eclogite from the Sulu ultrahigh-pressure (UHP) terrane.
DS202008-1420
2020
Bobrov, A.V.Matrosova, E.M., Bobrov, A.V., Bindi, L., Pushcharovsky, D.Yu., Irifune, T.Titanium rich phases in the Earth's transition zone and lower mantle: evidence from experiments in the system MgO-SiO2-TiO2(+-Al2O3) at 10-24 Gpa and 1600 C.Lithos, Vol. 366-367 1055539 14 p. pdfMantlebridgemanite

Abstract: Phase relations in the MgSiO3-MgTiO3 and Mg3Al2Si3O12-MgTiO3 systems were studied at 10-24 GPa and 1600 °C using a high-pressure Kawai-type multianvil apparatus. We investigated the full range of starting compositions for the enstatite-geikielite system to derive a P-X phase diagram and synthesize titanium-bearing phases, such as olivine/wadsleyite, rutile, pyroxene, MgTiSi2O7 weberite, bridgmanite and MST-bridgmanite in a wide pressure range. Olivine and pyroxene in run products are characterized by a low titanium content (<0.6 and <0.3 wt% TiO2, respectively) whereas the content of TiO2 in wadsleyite reaches 2 wt% at 12 GPa. The concentration of Ti in MgTiSi2O7 weberite decreases with pressure from 52 wt% TiO2 at 14 GPa to 43 wt% TiO2 at 18 GPa. Two perovskite-type structures (MgSiO3 bridgmanite and Mg(Si,Ti)O3 bridgmanite) were detected in the studied system. MgSiO3 bridgmanite (Brd) is formed at a pressure of >20 GPa and characterized by significant titanium solubility (up to 13 wt% TiO2 at 24 GPa). Mg(Si,Ti)O3 perovskite is formed at a pressure of >17 GPa. The concentration of TiO2 in this phase varies from 29 wt% to 49 wt%. It was found that addition of Ti to the system moves the boundaries of Ol/Wad phase transformations to lower pressures. Addition of Al to the starting material allows us to simulate the composition of natural Ti-rich garnets and bridgmanites. It is important to note that garnet in the Prp-Gkl system is stable throughout a wide pressure range (10-24 GPa). Al incorporation does not affect the distribution of titanium between two types of bridgmanite. It is shown that high contents of Ti stabilize bridgmanite-like compounds at considerably lower pressure than that at the lower mantle/transition zone boundary. Our experiments simulate the composition of natural Ti-rich primary garnet found in eclogite from the Sulu ultrahigh-pressure (UHP) terrane.
DS202009-1632
2020
Bobrov, A.V.Iskrina, A., Spivak, A.V., Bobrov, A.V., Eremin, N.N., Marchenko, E.I., Dubrovinsky, L.S.Synthesis and crystal structures of new high-pressure phases CaAl2O4 and Ca2Al6O11.Lithos, Vol. 374-375, 6p. PdfMantlegarnet

Abstract: The phases of CaAl2O4 and Ca2Al6O11 were synthesized at 15 GPa and 1600 °C. Microprobe data gave formulae Ca1.003Al1.998O4 and Ca2.05Al5.97O11, on the basis of 4 and 11 oxygen atoms. The crystal structures have been refined by single-crystal X-ray diffraction. Orthorhombic unitcell parameters for CaAl2O4 are a = 8.8569(10) Å; b = 2.8561(4) Å; c = 10.2521(11) Å; V = 259.34(5) Å3; Z = 8 (space group Pnma). The Ca2Al6O11 phase was obtained for the first time. It crystallizes with a space group P42/mnm and has lattice parameters a = b = 11.1675(4) Å; c = 2.83180(10) Å; V = 353.16(2) Å3; Z = 2. A Raman spectrum was obtained for a new phase for the first time. Our results suggest that both studied phases are stable under the condition of the transition zone and can be considered as potential aluminum concentrators in the Earth's deep geospheres.
DS1983-0494
1983
Bobrov, B.A.Orlov, YU.A., Gik, L.D., Bobrov, B.A., Kolobova, S.E.Modelling of the Effect of a Kimberlite Pipe on a Seismic Wave Field.Soviet Geology And Geophysics, Vol. 24, No. 3, PP. 88-94.RussiaKimberlite, Geophysics
DS1990-1525
1990
Bobrov, I.D.Vorontosov, A.E., Polozov, A.G., Kostrovitskii, S.I., Bobrov, I.D.On the geochemistry of nickel and Co in post magmatic magnetites fromkimberlites.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 311, No. 1, pp. 179-182RussiaGeochemistry, Magnetites-kimberlites
DS1993-1211
1993
Bobrov, V.A.Pechnikov, V.A., Bobrov, V.A., Podkuyko, A.Isotopic compositions of diamond and accompanying graphite in north Kazakstan metamorphic rocks.Geochemistry International, Vol. 30, No. 8, pp. 153-157.Russia, KazakhstanGeochronology, Diamond morphology
DS1993-1212
1993
Bobrov, V.A.Pechnikov, V.A., Bobrov, V.A., Popdkuyko, Yu.A.Isotope composition of diamond and accompanying graphite from metamorphic rocks of northern Kazakhstan.(Russian)Geochemistry International (Geokhimiya), (Russian), Vol. 1993, No. 1, pp. 150-154.Russia, Kazakhstan, Commonwealth of Independent States (CIS)Geochronology, Diamond
DS2003-1022
2003
Bobrov, V.A.Nozhkin, A.D., Turkina, O.M., Bobrov, V.A.Radioactive and rare earth elements in metapelites as indicators of composition andDoklady Earth Sciences, Vol. 391, 5, pp. 718-22.Russia, SiberiaGeochemistry - not specific to diamonds
DS200412-1451
2003
Bobrov, V.A.Nozhkin, A.D., Turkina, O.M., Bobrov, V.A.Radioactive and rare earth elements in metapelites as indicators of composition and evolution of the Precambrian continental cruDoklady Earth Sciences, Vol. 391, 5, pp. 718-22.Russia, SiberiaGeochemistry - not specific to diamonds
DS1991-1919
1991
Bobrov, Yu.D.Zakharov, M.N., Bobrov, Yu.D.First find of potassic basalt in volcanic rocks in the Magadan region Of the Okhotsk-Chukotka volcanic beltDoklady Academy of Science USSR, Earth Science Section, Vol. 308, No. 5, pp. 216-219RussiaPotassic basalt, Alkaline rocks
DS200412-1606
2004
Bobrovsky, P.T.Quattara, T., Couture, R., Bobrovsky, P.T., Moore, A.Remote Sensing and geosciences.Geological Survey of Canada Open File, No. 4542, 1 CD $ 26. 109p.GlobalRemote sensing - overview
DS1995-0161
1995
Bobrowksy, P.T.Bobrowksy, P.T., Sibbick, S.J., Newell, J.N., Matysek, P.Drift exploration in the Canadian CordilleraBritish Columbia Ministry of Energy and Mines, Paper 1995-2, 304p. $ 40.00British ColumbiaGeochemistry, Drift exploration- review
DS1995-0162
1995
Bobrowsky, P.T.Bobrowsky, P.T., Sibbick, S.J., Newell, J.M., Matysek, P.F.Drift exploration in the Canadian CordilleraBritish Columbia Energy Mines Resources, Paper, 1995-2, 290p.British Columbia, YukonGeomorphology, Drift prospecting - applicable to gold
DS1999-0077
1999
Bobrowsky, P.T.Bobrowsky, P.T.Cordilleran glaciers and Quaternary stratigraphyAssocation of Exploration Geologists (AEG) 19th. Drift Exploration Glaciated, S.C., pp. 32-66.Cordillera, British ColumbiaGeomorphology, glacial, geochemistry, Drift prospecting - not specific to diamonds
DS2001-0116
2001
Bobrowsky, P.T.Bobrowsky, P.T.Geoenvironmental mapping... method, theory and practiceBalkema Publishing, 750p. approx. $ 140.00GlobalBook - ad, Geoenvironment
DS1987-0174
1987
Bobylev, I.B.Dymkin, A.M., Bobylev, I.B., Anfilogov, V.N.Study of low temperature immiscibility of melts in the systemleucite-fayalite-anorthite-silicaDoklady Academy of Science USSR, Earth Science Section, Vol. 284, No. 5, Publishing July 1987, pp. 120-122RussiaLeucite
DS200512-0956
2006
Boccaletti, D.Scoppola, B., Boccaletti, D., Bevis, M., Carminati, E., Doglioni, C.The westward drift of the lithosphere: a rotational drag?Geological Society of America Bulletin, Vol. 118, 1, pp. 199-209.MantleGeophysics
DS201904-0719
2019
Boccato, S.Boulard, E., Harmand, M., Guyot, F., Lelong, G., Morard, D., Cabaret, D., Boccato, S., Rosa, A.D., Briggs, R., Pascarelli, S., Fiquet, G.Ferrous iron under oxygen rich conditions in the deep mantle.Geophysical Research Letters, Vol. 46, 3, pp. 1348-1356.MantleUHP

Abstract: Iron oxides are important end?members of the complex materials that constitute the Earth's interior. Among them, FeO and Fe2O3 have long been considered as the main end?members of the ferrous (Fe2+) and ferric (Fe3+) states of iron, respectively. All geochemical models assume that high oxygen concentrations are systematically associated to the formation of ferric iron in minerals. The recent discovery of O22? peroxide ions in a phase of chemical formula FeO2Hx stable under high?pressure and high?temperature conditions challenges this general concept. However, up to now, the valences of iron and oxygen in FeO2Hx have only been indirectly inferred from a structural analogy with pyrite FeS2. Here we compressed goethite (FeOOH), an Fe3+?bearing mineral, at lower mantle pressure and temperature conditions by using laser?heated diamond?anvil cells, and we probed the iron oxidation state upon transformation of FeOOH in the pressure-temperature stability field of FeO2Hx using in situ X?ray absorption spectroscopy. The data demonstrate that upon this transformation iron has transformed into ferrous Fe2+. Such reduced iron despite high oxygen concentrations suggests that our current views of oxidized and reduced species in the lower mantle of the Earth should be reconsidered.
DS1990-0216
1990
Bocchio, R.Bocchio, R., De Capitani, L., Liborio, G., Maresch, W.V., MottanaThe eclogite bearing series of Isla Margarita, Venezuela: geochemistry of metabasic lithologies in the la Rinconada and Juan Griego GroupsLithos, Vol. 25, No. 1-3, November pp. 55-70VenezuelaEclogites, Geochemistry
DS1992-0136
1992
Bochariv, G.V.Bochariv, G.V., et al.Horizontal movements and tectonophysical geodectic zonation of the South-Yakutian geodynamic polygonJournal of Geodynamics, Vol. 15, No. 3-4, August pp. 163-168Russia, YakutiaTectonics, Geophysics
DS1992-0137
1992
Bocharov, G.V.Bocharov, G.V., et al.Horizontal movements and tectonophysical geodetic zonation of the south Yakutian geodynamic polygon.Journal of Geodynamics, Vol. 15, No. 3-4, pp. 163-67.Russia, YakutiaGeodynamics, Tectonics
DS1986-0079
1986
Bocharov, V.I.Bocharov, V.I., Bagdasarova, V.V., Belykh, V.I.The apatite content of the Kursk magnetic anomaly carbonatite complexInternational Geology Review, Vol. 28, No. 11, November pp. 1327=1335RussiaGeophysics, Carbonatite
DS1989-0131
1989
Bocharov, V.L.Bocharov, V.L., Kantersov, V.A., Gurvich, M.Yu., Chesko, V.M.Radio element distributions in the Precambrian Alkaline rocks of a dikecomplexGeochemistry International, Vol. 26, No. 9, pp. 79-84RussiaAlkaline rocks, UraniuM.
DS1989-1227
1989
Bocharov, V.L.Plaksenko, A.N., Girnis, A.V., Bocharov, V.L.Crystallization conditions of the gabbro-norite of the Yelan nickel bearing plutonInternational Geology Review, Vol. 31, No. 5, May pp. 502-505RussiaPseudobrookite-lamproite association
DS201803-0487
2018
Bocharov, 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
DS201905-1046
2019
Bocharov, 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.
DS202111-1759
2021
Bocharov, V.N.Britvin, S., Vlasenko, N.S., Aslandukov, A., Aslandova, A., Dubovinsky, L., Gorelova, L.A., Krzhizhanvskaya, M.G., Vereshchagin, O.S., Bocharov, V.N., Shelukina, Y.S., Lozhkin, M.S., Zaitsev, A.N., Nestola, F.Natural cubic perovskite, Ca(Ti,Si,Cr) O 3-delta, a versatile potential host rock-forming and less common elements up to Earth's mantle pressure.American Mineralogist, doi:10.2138/am-2022-8186 in pressMantleperovskite

Abstract: Perovskite, CaTiO3, originally described as a cubic mineral, is known to have a distorted (orthorhombic) crystal structure. We herein report on the discovery of natural cubic perovskite. This was identified in gehlenite rocks occurring in a pyrometamorphic complex of the Hatrurim Formation (the Mottled Zone), in the vicinity of the Dead Sea, Negev Desert, Israel. The mineral is associated with native ?-(Fe,Ni) metal, schreibersite (Fe3P) and Si-rich fluorapatite. The crystals of this perovskite reach 50 ?m in size and contain many micron sized inclusions of melilite glass. The mineral contains significant amounts of Si substituting for Ti (up to 9.6 wt.% SiO2) corresponding to 21 mol.% of the davemaoite component (cubic perovskite-type CaSiO3), in addition to up to 6.6 wt.% Cr2O3. Incorporation of trivalent elements results in the occurrence of oxygen vacancies in the crystal structure; this being the first example of natural oxygen-vacant ABO3 perovskite with the chemical formula Ca(Ti,Si,Cr)O3-? (? ~ 0.1). Stabilization of cubic symmetry (space group Pm?3m) is achieved via the mechanism not reported so far for CaTiO3, namely displacement of an oxygen atom from its ideal structural position (site splitting). The mineral is stable at atmospheric pressure to 1250±50 °C; above this temperature its crystals fuse with the embedded melilite glass, yielding a mixture of titanite and anorthite upon melt solidification. The mineral is stable upon compression to at least 50 GPa. The a lattice parameter exhibits continuous contraction from 3.808(1) Å at atmospheric pressure to 3.551(6) Å at 50 GPa. The second-order truncation of the Birch-Murnaghan equation of state gives the initial volume V0 equal to 55.5(2) Å3 and room temperature isothermal bulk modulus K0 of 153(11) GPa. The discovery of oxygen-deficient single perovskite suggests previously unaccounted ways for incorporation of almost any element into the perovskite framework up to pressures corresponding to those of the Earth’s mantle.
DS1975-0694
1978
Bocharova, G.I.Bocharova, G.I., Garanin, V.K., Jilyaeva, V.A., Kudryavtseva, G.New Dat a on Exolution Lamellae in Picroilmenites from Jakutia Kimberlite Pipes.Jeol. News, Vol. 16E, No. 1, PP. 18-24.Russia, YakutiaMineralogy, Genesis, Kimberlite
DS1984-0595
1984
Bocharova, G.I.Posukhova, T.V., Bocharova, G.I., Kudryavtseva, G.P., Soshkina.Features of Morphology and Internal Structure of Ilmenite from kimberlites of the Malo Botuobinskii Region of Yakutia.Moscow University Geol. Bulletin., Vol. 39, No. 6, PP. 36-44.Russia, YakutiaMicroscopy, Mineralogy, Amaka Pipe, Taezhnyi
DS1986-0080
1986
Bocharova, G.I.Bocharova, G.I., Garanin, V.K., Kudryavtseva, G.P.Sulfide mineralization in the kimberlite of YakutiaInternational Mineralogical Association Meeting, held Bulgaria Sept. 1982, Publishing in:, Vol. 13, pp. 107-119RussiaSulphides, Kimberlite
DS1984-0159
1984
Bochek, L.I.Bochek, L.I., et al.Reflection Spectra and Refractive Index of Lonsdaleite Containing Diamonds.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 279, No. 1, PP. 186-188.RussiaGenesis
DS1984-0160
1984
Bochek, L.I.Bochek, L.I., Nadezhdina, YE.D., Rumyantsev, G.S.Reflection spectra and refractive index of lonsdaleite-containingdiamonds.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 279, No. 1, pp. 186-188RussiaDiamond Morphology
DS201805-0936
2018
Bocher, M.Bocher, M., Fournier, A., Coltice, N.Ensemble Kalman filter for the reconstruction of the Earth's mantle circulation.Nonlinear Processes Geophysics, Vol. 25, pp. 99-123. pdfMantleconvection

Abstract: Recent advances in mantle convection modeling led to the release of a new generation of convection codes, able to self-consistently generate plate-like tectonics at their surface. Those models physically link mantle dynamics to surface tectonics. Combined with plate tectonic reconstructions, they have the potential to produce a new generation of mantle circulation models that use data assimilation methods and where uncertainties in plate tectonic reconstructions are taken into account. We provided a proof of this concept by applying a suboptimal Kalman filter to the reconstruction of mantle circulation (Bocher et al., 2016). Here, we propose to go one step further and apply the ensemble Kalman filter (EnKF) to this problem. The EnKF is a sequential Monte Carlo method particularly adapted to solve high-dimensional data assimilation problems with nonlinear dynamics. We tested the EnKF using synthetic observations consisting of surface velocity and heat flow measurements on a 2-D-spherical annulus model and compared it with the method developed previously. The EnKF performs on average better and is more stable than the former method. Less than 300 ensemble members are sufficient to reconstruct an evolution. We use covariance adaptive inflation and localization to correct for sampling errors. We show that the EnKF results are robust over a wide range of covariance localization parameters. The reconstruction is associated with an estimation of the error, and provides valuable information on where the reconstruction is to be trusted or not.
DS2000-0093
2000
Bock, B.Bock, B., Bahlburg, H., Worner, G., Zimmermann, U.Tracing crustal evolution in the Southern Central Andes from late Precambrian to Permian geochemical isotopeJournal of Geology, Vol. 108, pp. 515-35.Argentina, Chile, Andes, South AmericaGeochemistry, geochronology, craton, Paleotectonics
DS1860-0360
1881
Bock, C.A.Bock, C.A.The Head Hunters of Borneo: a Narrative of Travels Up the Mahakkam and Down the Barito; Also Journeyings in Sumatra.London: S. Low, Marston, Searle And Rivington., 344P.Asia, Borneo, SumatraTravelogue
DS201212-0835
2012
Bock, E.Zurba, M., Ross, H., Izurieta, A., Rist, P., Bock, E., Berkes, F.Melt inclusions in olivines from early Iceland plume picrites support high 3He/4He in both enriched and depleted mantle.Chemical Geology, Vol. 306-307, pp. 54-62.Europe, IcelandPicrite
DS200612-1501
2005
Bock, G.Walker, K.T., Bokelmann, G.H., Klemperer, S.L., Bock, G.Shear wave splitting around the Eifel hotspot: evidence for a mantle upwelling.Geophysical Journal International, Vol. 163, 3,Dec. pp. 962-980.Europe, GermanyGeophysics - seismics
DS200512-0097
2004
Bockrath, C.Bockrath, C., Ballhaus, C., Holzheid, A.Fractionation of the platinum group elements during mantle melting.Science, No. 5692, Sept. 24, pp. 1951-1952.MantleGeochemistry
DS1975-0137
1975
Boctor, N.Z.Meyer, H.O.A., Boctor, N.Z.Sulfide Oxide Minerals in Eclogite from Stockdale Kimberlite,kansas.Contributions to Mineralogy and Petrology, Vol. 52, PP. 57-68.KansasKimberlite, Central States, Xenoliths
DS1975-0465
1977
Boctor, N.Z.Boctor, N.Z., Meyer, H.O.A.Oxide and Sulfide Minerals in Kimberlite from Green Mountain Colorado #1International Kimberlite Conference SECOND, EXTENDED ABSTRACT VOLUME., United States, Colorado, Rocky Mountains, VermontBlank
DS1975-0695
1978
Boctor, N.Z.Boctor, N.Z., Boyd, F.R.Oxide Minerals in Liqhobong KimberliteCarnegie Institute Yearbook, FOR 1977, PP. 870-876.LesothoMineral Chemistry
DS1975-0696
1978
Boctor, N.Z.Boctor, N.Z., Svisero, D.P.Iron Titanium Oxide and Sulfide Minerals in Carbonatite From Jacupiranga Brasil.Carnegie Institute Yearbook, FOR 1977, PP. 876-880.BrazilRelated Rocks, Mineralogy
DS1975-0949
1979
Boctor, N.Z.Boctor, N.Z., Boyd, F.R.Oxide Minerals in Layered Kimberlite Carbonate Sills from Benfontein.Carnegie Institute Yearbook, FOR 1978, PP. 493-496.South AfricaMineral Chemistry
DS1975-0950
1979
Boctor, N.Z.Boctor, N.Z., Boyd, F.R.Petrology of Kimberlite from the de Bruyn and Martin Mine Bellsbank #2Carnegie Institute Yearbook, FOR 1978, PP. 496-498.South AfricaPetrology
DS1975-0951
1979
Boctor, N.Z.Boctor, N.Z., Boyd, F.R.Petrology of Kimberlite from the de Bruyn and Martin Mine Bellsbank #1Eos, Vol. 60, No. 18, P. 418. (abstract.).South AfricaPetrology
DS1975-0952
1979
Boctor, N.Z.Boctor, N.Z., Boyd, F.R.Distribution of Rare Earth Elements in Perovskite from Kimberlites.Carnegie Institute Yearbook, FOR 1978, PP. 572-574.South AfricaRare Earth Elements (ree), Isotope
DS1975-0953
1979
Boctor, N.Z.Boctor, N.Z., Meyer, H.A.O.Oxide and Sulfide Minerals in Kimberlite from Green Mountain Colorado #2International Kimberlite Conference Proceedings, Vol. 1, PP. 217-278.ColoradoKimberlite, Diatreme, Rocky Mountains
DS1980-0066
1980
Boctor, N.Z.Boctor, N.Z., Boyd, F.R.Oxide Minerals in the Liqhobong Kimberlite , LesothoAmerican MINERALOGIST., Vol. 65, No. 7-8, PP. 631-638.LesothoMineralogy
DS1980-0067
1980
Boctor, N.Z.Boctor, N.Z., Yoder, H.S. Jr.Distribution of Rare Earth Elements in Perovskite from Oka Carbonatite, quebec.Carnegie Institute Yearbook, FOR 1979 PP. 304-306.Canada, QuebecRelated Rocks, Mineralogy, Analyses
DS1981-0087
1981
Boctor, N.Z.Boctor, N.Z., Boyd, F.R.Oxide Minerals in a Layered Kimberlite Carbonate Sill from Benfontein South Africa.Contributions to Mineralogy and Petrology, Vol. 76, No. 3, PP. 253-259.South AfricaMineral Chemistry
DS1981-0096
1981
Boctor, N.Z.Boyd, F.R., Nixon, P.H., Boctor, N.Z.Quenched Rocks of Mantle Origin from the Mzongwana Kimberlite Dike, Transkei, Southern Africa.Carnegie Institute Yearbook, FOR 1980, PP. 328-336.South Africa, BotswanaXenoliths, Petrography
DS1982-0104
1982
Boctor, N.Z.Boctor, N.Z., Boyd, F.R.Petrology of Kimberlite from the Debruyn and Martin Mine, Bellsbank, South Africa.American MINERALOGIST., Vol. 67, PP. 917-925.South AfricaBlank
DS1982-0105
1982
Boctor, N.Z.Boctor, N.Z., Boyd, F.R., Nixon, P.H.Carbonate Tuff from Melkfontein, East Griqualand, South Africa.Proceedings of Third International Kimberlite Conference, TERRA COGNITA, ABSTRACT VOLUME., Vol. 2, No. 3, P. 211, (abstract.).South AfricaKimberlite, Mineralogy
DS1982-0106
1982
Boctor, N.Z.Boctor, N.Z., Yoder, H.S. Jr.Distribution of Rare Earth Elements in Perovskite from Melilite Bearing Rocks.Carnegie Institute Yearbook, FOR 1981 PP. 369-371.South AfricaRare Earth Elements (ree), Mineral Chemistry
DS1983-0136
1983
Boctor, N.Z.Boctor, N.Z., Boyd, F.R., Nixon, P.H.Pyroxenites, Eclogites, and Megacrysts in Kimberlite from The de Bruyn and Martin Mine, Bellsbank, South Africa.Carnegie Institute Yearbook, FOR 1982, PP. 346-349.South AfricaPetrology
DS1983-0137
1983
Boctor, N.Z.Boctor, N.Z., Yoder, H.S. Jr.Petrology of Olivine Melilitites from Saltpetre Kop and Sutherland Commage Cape Province, South Africa.Carnegie Institute Yearbook, FOR 1982, PP. 264-267.South AfricaPetrology
DS1983-0483
1983
Boctor, N.Z.Nixon, P.H., Boyd, F.R., Boctor, N.Z.East Griqualand KimberlitesGeological Society STH, AFR. Transactions, Vol. 86, No. 3, PP. 221-236.South AfricaTectonics, Chemical Composition, Genesis
DS1983-0643
1983
Boctor, N.Z.Yoder, H.S.JR., Boctor, N.Z.Olivine Melilitite from Saltpetre Kop, South AfricaEos, Vol. 64, No. 18, MAY 3RD. P. 341. (abstract.).South AfricaBlank
DS1984-0161
1984
Boctor, N.Z.Boctor, N.Z., Nixon, P.H., Buckley, F., Boyd, F.R.Petrology of Carbonate Tuff from Melkfontein, East Griqualand, Southern Africa.Proceedings of Third International Kimberlite Conference, Vol. 1, PP. 75-82.South Africa, LesothoGenesis, Rare Earth Elements (ree), Mineral Chemistry
DS1984-0170
1984
Boctor, N.Z.Boyd, F.R., Nixon, P.H., Boctor, N.Z.Rapidly Crystallized Garnet Pyroxenite Xenoliths Possibly Related to Discrete Nodules.Contributions to Mineralogy and Petrology, Vol. 86, PP. 119-130.South AfricaMzongwana, Kimberlite, Mineral Chemistry, Textures, Analyses
DS1986-0081
1986
Boctor, N.Z.Boctor, N.Z., Yoder, H.S. Jr.Petrology of some melilite bearing rocks from Cape Province Republic of South Africa: relationship to kimberlitesAmerican Journal of Science, Vol. 286, September pp. 513-539South AfricaMelilite
DS1987-0061
1987
Boctor, N.Z.Boctor, N.Z., Tera, F., Carlson, R.W., Svisero, D.P.Petrologic and isotopic investigation of carbonatite from the Jacupiranga alkaline complex, BrasilEos, abstractBrazilCarbonatite
DS1987-0823
1987
Boctor, N.Z.Yoder, H.S. Jr., Boctor, N.Z., Hofmeister, A.Barium and titanium micas from olivine melilitite: a potential new endmember micaEos, abstractSouth AfricaSaltpetre Kop
DS1994-0174
1994
Boden, D.R.Boden, D.R.Mid-Tertiary magmatism of Toquima caldera complex and vicinity: development explosive high -k, calc alkaline magmas central Great BasinContrib. Mineral Petrology, Vol. 116, pp. 247-276NevadaAlkaline rocks, Magmatism
DS201512-1991
2015
Bodeving, S.Williams-Jones, A.E., Wollenberg, R., Bodeving, S.Hydrothermal fractionaction of the rare earth elements and the genesis of the Lofdal REE deposit, Namibia.Symposium on critical and strategic materials, British Columbia Geological Survey Paper 2015-3, held Nov. 13-14, pp. 125-130.Africa, NamibiaRare earths
DS200412-0968
2004
Bodgan, D.J.Keller, G.R., Bodgan, D.J., Matile, G.L.D.Manitoba kimberlite indicator mineral database Version 2.0.Manitoba Geological Survey, Canada, ManitobaGeochemistry - database
DS2002-0177
2002
Bodgen, G.J.Bodgen, G.J.Mergers and amp; acquisitions: where do we go from here?Minerals & Energy Raw Materials Report, Vol. 17, 3, Oct. 1, pp. 32-44.GlobalEconomics
DS201312-0916
2013
Bodin, T.Tkalcic, H., Young, M.K., Bodin, T., Ngo, S., Sambridge, M.The shuffling rotation of the Earth's inner core.Nature Geoscience, Vol. 6, pp. 497-502.MantleGeodynamics
DS201412-1011
2013
Bodin, T.Young, M.K., Tkalcic, H., Bodin, T., Sambridge, M.Global P wave tomography of Earth's lowermost mantle from partition modeling.Journal of Geophysical Research, Vol. 118, 10, pp. 5467-5486.MantleGeophysics - tomography
DS201607-1289
2016
Bodin, T.Calo, M., Bodin, T., Romanowicz, B.Layered structure in the upper mantle across North America from joint inversion of long and short period seismic data.Earth and Planetary Science Letters, Vol. 449, pp. 164-175.United States, CanadaGeophysics - seismics

Abstract: We estimate crustal and uppermost mantle shear velocity structure beneath 30 stations in North America by jointly inverting the high frequency scattered wavefield observed in the P wave coda, together with long period surface wave phase and group dispersion data. Several features distinguish our approach from previous such joint inversions. 1) We apply a cross-convolution method, rather than more standard deconvolution approaches used in receiver function studies, and consider both Love and Rayleigh wave dispersion, allowing us to infer profiles of radial anisotropy. 2) We generate probabilistic 1D radially anisotropic depth profiles across the whole uppermost mantle, down to ?350 km depth. 3) The inverse problem is cast in a trans-dimensional Bayesian formalism, where the number of isotropic and anisotropic layers is treated as unknown, allowing us to obtain models described with the least number of parameters. Results show that the tectonically active region west of the Rocky Mountain Front is marked by a Lithospheric Asthenosphere Boundary and a Lehmann Discontinuity occurring at relatively shallow depths (60-150 km and 100-200 km, respectively), whereas further east, in the stable craton, these discontinuities are deeper (170-200 km and 200-250 km, respectively). In addition, in the stable part of the continent, at least two Mid-Lithospheric Discontinuities are present at intermediate depths, suggesting the existence of strong lithospheric layering, and a mechanism for lithospheric thickening by underplating of additional layers as cratonic age increases. The Moho across the continent as well as mid-crustal discontinuities in the craton are also imaged, in agreement with independent studies.
DS201807-1539
2018
Bodin, T.Yuan, H., Bodin, T.A probabilistic shear wave velocity model of the crust in the central west Australian craton constrained by transdimensional inversion of ambient noise dispersion.Tectonics, June 12, DOI: 10.129/ 2017TC004834Australiageophysics - seismic

Abstract: The Capricorn Orogen in central Western Australia played important roles in initializing and finalizing the West Australian craton. Surface geological mapping and isotopic studies show that the crust has recorded over a billion years of tectonic history spanning from its crustal formation in the Archean to episodes of tectono?thermal events during the Proterozoic cratonization processes. The region therefore provides us with an ideal laboratory to characterize the seismic signature associated with tectonic processes. We constructed a crustal shear?wave velocity model of the core region of the orogen, the Glenburgh Terrane and its north boundary, by inverting the array group velocity dispersion data measured from a high density temporary array. A modified Bayesian Transdimensional tomography technique, which incorporates a smooth?varying regional reference velocity model and Moho topography, was used to invert for the crustal velocity variations. The inverted velocity model adds great detail to the intra?crustal structure, and provides complementary seismic velocity information to refine the regional tectonic processes. Distinct patterns in the velocity structure support that the Glenburgh Terrane is a microcontinent originated in the Archean, and favor the operation of Paleoproterozoic subduction/accretion leading to the 2.2 Ga Ophthalmian orogeny that initiated the assembly of the West Australian craton.
DS202004-0529
2020
Bodin, T.Petrescu, L., Bastow, I.D., Darbyshire, F.A., Gilligan, A., Bodin, T., Menke, W., Levin, V.Three billion years of crustal evolution in eastern Canada: constraints from receiver functions.Journal of Geophysical Research: Solid Earth, in press available, 24p. PdfCanadageophysics - seismics

Abstract: The geological record of SE Canada spans more than 2.5Ga, making it a natural laboratory for the study of crustal formation and evolution over time. We estimate the crustal thickness, Poisson's ratio, a proxy for bulk crustal composition, and shear velocity (Vs) structure from receiver functions at a network of seismograph stations recently deployed across the Archean Superior craton, the Proterozoic Grenville and the Phanerozoic Appalachian provinces. The bulk seismic crustal properties and shear velocity structure reveal a correlation with tectonic provinces of different ages: the post-Archean crust becomes thicker, faster, more heterogenous and more compositionally evolved. This secular variation pattern is consistent with a growing consensus that crustal growth efficiency increased at the end of the Archean. A lack of correlation among elevation, Moho topography, and gravity anomalies within the Proterozoic belt is better explained by buoyant mantle support rather than by compositional variations driven by lower crustal metamorphic reactions. A ubiquitous ?20km thick high-Vs lower-crustal layer is imaged beneath the Proterozoic belt. The strong discontinuity at 20km may represent the signature of extensional collapse of an orogenic plateau, accommodated by lateral crustal flow. Wide anorthosite massifs inferred to fractionate from a mafic mantle source are abundant in Proterozoic geology and are underlain by high Vs lower crust and a gradational Moho. Mafic underplating may have provided a source for these intrusions and could have been an important post-Archean process stimulating mafic crustal growth in a vertical sense.
DS202102-0227
2021
Bodin, T.Vilella, K., Bodin, T., Boukare, C-E.,Deschamp, F., Badro, J., Ballmer, M.D. Li, Y.Constraints on the composition and temperature of LLSVPs from seismic properties of lower mantle minerals.Earth and Planetary Science Letters, Vol. 554, doi:10.1016/j.epsl.2020.116685Mantlegeophysics - seismic

Abstract: Here, we provide a reappraisal of potential LLSVPs compositions based on an improved mineralogical model including, for instance, the effects of alumina. We also systematically investigate the effects of six parameters: FeO and Al2O3 content, proportion of CaSiO3 and bridgmanite (so that the proportion of ferropericlase is implicitly investigated), Fe3+/?Fe and temperature contrast between far-field mantle and LLSVPs. From the 81 millions cases studied, only 79000 cases explain the seismic observations. Nevertheless, these successful cases involve a large range of parameters with, for instance, FeO content between 12--25~wt\% and Al2O3 content between 3--17~wt\%. We then apply a principal component analysis (PCA) to these cases and find two robust results: (i) the proportion of ferropericlase should be low (<6vol\%); (ii) the formation of Fe3+-bearing bridgmanite is much more favored than other iron-bearing phases. Following these results, we identify two end-member compositions, Bm-rich and CaPv-rich, and discuss their characteristics. Finally, we discuss different scenarios for the formation of LLSVPs and propose that investigating the mineral proportion produced by each scenario is the best way to evaluate their relevance. For instance, the solidification of a primitive magma ocean may produce FeO and Al2O3 content similar to those suggested by our analysis. However, the mineral proportion of such reservoirs is not well-constrained and may contain a larger proportion of ferropericlase than what is allowed by our results.
DS1991-0413
1991
BodinierDupuy, C., Mevel, C., Bodinier, J-L, Savoyant, L.Zabargad peridotite: evidence for multistage metasomatism during Red SeariftingGeology, Vol. 19, No. 7, July pp. 722-725GlobalMantle Metasomatism, Peridotites
DS1998-0826
1998
BodinierLambert, D.D., Alard, O., Costa, S., Frick, BodinierEvidence for interaction of Proterozoic (2 Ga) sub-continental mantle wit han enriched mantle plume...Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 848-9.FranceMelt depletion, peridotite xenoliths, Franch Massif Central
DS1987-0062
1987
Bodinier, J.L.Bodinier, J.L., DupuyDistribution of trace transition elements in olivine and pyroxenes from ultramafic xenoliths: application of microprobe analysisAmerican Mineralogist, Vol. 72, pp. 902-913LesothoAnalyses
DS1990-0218
1990
Bodinier, J.L.Bodinier, J.L., Vasseur, G., Vernieres, J., Dupuy, C., Fabries, J.Mechanisms of mantle metasomatism: geochemical evidence from the Lherzorogenic peridotiteJournal of Petrology, Vol. 31, No. 3, June pp. 597-628GermanyMantle Metasomatism, Geochemistry
DS1991-1130
1991
Bodinier, J.L.Menzie, M.A., Bodinier, J.L., Thirlwall, M., Downes, H.Asthenosphere-lithosphere relationships within orogenic massifsProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 281-284ItalyThermal boundary layer, hydrofracturing, xenoliths, Proterozoic, classification, characteristics
DS1992-1694
1992
Bodinier, J.L.Woodland, A., Bussod, G., Kornprobst, J., Bodinier, J.L.The effect of mafic dike emplacement on surrounding peridotite: evidence from spinel compositions and estimated redox statesGeological Society of America (GSA) Abstracts with programs, 1992 Annual, Vol. 24, No. 7, abstract p. A85France, PyreneesPeridotite, Mantle Metasomatism
DS1993-0928
1993
Bodinier, J.L.Lorand, J.P., Keays, R.R., Bodinier, J.L.Copper and noble metal enrichments across the lithosphere asthenosphere boundary of mantle diapirs: evidence from the Lanzo lherzolite massifJournal of Petrology, Vol. 34, No. 4 and 6, December pp. 1111-1140GlobalCopper, Boundary, Mantle diapirs
DS1993-1019
1993
Bodinier, J.L.Menzies, M.A., Bodinier, J.L.Growth of the European lithospheric mantle-dependence of upper mantle peridotite facies and chemical heterogeneity on tectonics and age.Physics of the Earth and Planetary Interiors, Vol. 79, pp. 219-240.EuropeMantle, Peridotites
DS1993-1020
1993
Bodinier, J.L.Menzies, M.A., Bodinier, J.L.Growth of the European lithospheric mantle- dependence of upper mantle peridotite facies and chemical heterogeneity on tectonics and age.Physics and Earth Planetary Sciences, Vol. 79, No. 1-2, August pp. 219-240.Europe, MantleTectonics, Peridotite
DS1994-1170
1994
Bodinier, J.L.Menzies, M.A., Bodinier, J.L., Downes, H., Thirlwall, M.Temporal and spatial relationships organic lherzolite massifs -a key understanding depleted and shallow mantle xenoliths.Proceedings of Fifth International Kimberlite Conference, Vol. 1, pp. 423-433.MantleXenoliths, Lherzolites
DS1995-0131
1995
Bodinier, J.L.Bedini, R.M., Bodinier, J.L., Dautria, J.M., Morten, L.Superimposed metasomatic processes in lithospheric mantle beneath East African Rift: a single melt sourceProceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 44-46.GlobalMetasomatism, Xenoliths
DS1996-0145
1996
Bodinier, J.L.Bodinier, J.L., Merlet, C., Bedini, R.M., et al.Distribution of niobium, tantalum - highly incompatible trace elements lithospheric mantle: spinel paradox.Geochimica et Cosmochimica Acta, Vol. 60, No. 3, Feb. pp. 545-550.MantleSpinels, Lithosphere
DS1998-0098
1998
Bodinier, J.L.Bedini, R.M., Bodinier, J.L.Distribution of incompatible trace elements between the constituents of mantle spinel peridotites: inversionMineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 135-6.MantlePeridotites, Lithophile trace elements
DS1998-0099
1998
Bodinier, J.L.Bedini, R.M., Bodinier, J.L., Dautria, J.M., Morten, L.Evolution of large-ion lithophile elements (LILE) enriched small melt fractions in the lithospheric mantle:case study from East African Rift.Earth and Planetary Science Letters, Vol. 153, No. 1-2, pp. 67-83.GlobalEast African Rift, Tectonics, Mantle peridotites
DS1998-0475
1998
Bodinier, J.L.Garrido, C.J., Bodinier, J.L.Distribution of trace elements in minerals from anhydorus spinel peridotites and websterites...RondaMineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 498-9.GlobalMelt-peridotite, large-ion lithophile elements (LILE) rare earth elements (REE) HFSE reservoirs in subcontinental lithosphere
DS1998-1607
1998
Bodinier, J.L.Xu, Y.G., Bodinier, J.L., Bedini, R.M., Menzies, M.A.Xenolith evidence for melt rock reaction at the lithosphere plumeboundary.Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1671-2.FrancePetrography, geochemistry, Harzburgites, Boree P type
DS1999-0238
1999
Bodinier, J.L.Garrido, C.J., Bodinier, J.L.Diversity of mafic rocks in the Ronda peridotite: evidence - pervasive melt rock reaction during heatingJournal of Petrology, Vol. 40, No. 5, May, pp. 729-54.MantleSubcontinental lithosphere, Upwelling asthenosphere
DS2000-0314
2000
Bodinier, J.L.Garrido, C.J., Bodinier, J.L., Alard, O.Incompatible trace element partioning and residence in anhydrous spinel peridotites and websterites from RondaEarth and Planetary Science Letters, Vol.181, No.3, Sept.15, pp.327-40.GlobalPeridotites, Deposit - Ronda
DS2000-0567
2000
Bodinier, J.L.Lenoir, X., Garrido, C.J., Bodinier, J.L., Dautria, J-M.Contrasting lithospheric mantle domains beneath the Massif Central revealed by geochemistry peridotite...Earth and Planetary Science Letters, Vol.181, No.3, Sept.15, pp.359-75.FranceXenoliths - geochemistry
DS2002-0400
2002
Bodinier, J.L.Downes, H., Kostoula, T., Jones, A.P., Beard, A.D., Thirwall, M.F., Bodinier, J.L.Geochemistry and Sr Nd isotopic compositions of mantle xenoliths from the MonteContributions to Mineralogy and Petrology, Vol. 144, 1, Oct. pp. 78-92.ItalyMelilite - carbonatite - not specific to diamonds
DS2002-0749
2002
Bodinier, J.L.Ionov, D.A., Mukasa, S.B., Bodinier, J.L.Sr Nd Pb isotopic compositions of peridotite xenoliths from Spitsbergen: numericalJournal of Petrology, Vol. 43, 12, pp. 2261-78.Mantle, NorwayMetasomatism, Geochronology
DS2003-0620
2003
Bodinier, J.L.Ionov, D., Spetsius, Z., Weiss, D., Bodinier, J.L.Hf Nd Sr isotope and trace element evidence for a diversity of origins of rutile bearingGeological Association of Canada Annual Meeting, Abstract onlyRussia, SiberiaGeochronology, Eclogite
DS200412-0872
2003
Bodinier, J.L.Ionov, D., Spetsius, Z., Weiss, D., Bodinier, J.L.Hf Nd Sr isotope and trace element evidence for a diversity of origins of rutile bearing eclogite xenoliths from the Siberian CrGeological Association of Canada Annual Meeting, Abstract onlyRussia, SiberiaGeochronology Eclogite
DS200512-0461
2005
Bodinier, J.L.Ionov, D., Prikhodko, V.S., Bodinier, J.L., Sobolev, A.V., Weis, D.Lithospheric mantle beneath the south eastern Siberian Craton: petrology of peridotite xenoliths in basalts from the Tokinsky Stanovik.Contributions to Mineralogy and Petrology, Vol. 149, no. 6, pp. 647-665.Russia, SiberiaXenoliths
DS200612-0118
2006
Bodinier, J.L.Ben Othman, D., Luck, J.M., Bodinier, J.L., Arndt, N.T., Albarede, F.Cu Zn isotopic variations in the Earth's mantle.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.MantleGeochemistry
DS200612-0621
2005
Bodinier, J.L.Ionov, D.A., Chanefo, I., Bodinier, J.L.Origin of Fe rich lherzolites and wehrlites from Tok, SE Siberia by reactive melt percolation in refractory mantle peridotites.Contributions to Mineralogy and Petrology, Vol. 150, 3, pp. 335-353.RussiaLherzolite
DS200612-0622
2006
Bodinier, J.L.Ionov, D.A., Chazot, G., Chauvel, C., Merlet, C., Bodinier, J.L.Trace element distribution in peridotite xenoliths from Tok, SE Siberian craton: a record of pervasive, multi stage metasomatism in shallow refractory mantle.Geochimica et Cosmochimica Acta, Vol. 70, 5, pp. 1231-1260.RussiaMetasomatism - Tok
DS200812-0011
2008
Bodinier, J.L.Alard, O., Le Roux, V., Bodinier, J.L., Lorand, J.P., Griffin, W.L., O'Reilly, S.Y.How primitive is the 'primitive' mantle?Goldschmidt Conference 2008, Abstract p.A13.MantleGeochemistry, structure
DS201312-0265
2013
Bodinier, J.L.Fernandez, L., Bosch, D., Elmessbahi, H., Bodinier, J.L., Dautra, J.M., Verdoux, P.Lithosphere-asthenosphere interactions (Middle Atlas (Morocco): geochemical highlights.Goldschmidt 2013, AbstractAfrica, MoroccoXenoliths
DS201709-1979
2017
Bodinier, J.L.Djeddi, A., Parat, F., Ouzegane, K., Bodinier, J.L.Ree enrichment in apatite Britholite exsolutions in carbonatite in Quezal terrane, Hoggar, South Algeria.Goldschmidt Conference, abstract 1p.Africa, Algeriacarbonatite, Ouzzal

Abstract: Ihouhaouene area in In Ouzzal terrane (Hoggar, South Algeria) is exceptional by numerous carbonatite complexes systematically associated to syenites. They constitute one of the oldest carbonatite emplaced at 2 Ga. Various types of carbonatites are distinguished by their successive placement and pegmatitic to brecciated appearance. The first-generation of carbonatites are always brecciated with elements of syenite and carbonate cement with calcite, apatite, alkali feldspar, wollastonite, clinopyroxene +/- sphene, allanite, quartz and garnet. Late carbonatite intrusions appear in small pegmatitic veins rich in apatite (3-50 mm). All carbonatites are calciocarbonatites (38-50 wt% CaO) with silica content ranging from 5 to 21 wt% SiO2. The high silica content is interpreted as assimilation of syenite material during emplacement. Carbonatites have high Rare Earth Element (REE) concentrations with high Ligh REE/Heavy REE fractionation (e.g. 1088 ppm La, La/Yb= 144-198) and variable concentrations in Th (26.5-197 ppm). The REE concentrations are mainly controlled by apatite phenocrysts (30-40 vol.%) with 4-9 wt% REE. In late pegmatitic carbonatite, REE-rich apatites are green-yellow phenocrysts with britholite exsolution (up to 40 vol.%, Ca4(REE)6 (SiO4,PO4)6 (OH,F,Cl)2). Britholites are hexagonal and occur as fine lamellar exsolutions (<10 um) in the same crystallographic axis (001) than apatites or as irregularshaped grains (10-200 um). All britholites contain 8-16 wt% La, 21-43 wt% Ce and 7-12 wt% Nd. The apatite-britholite exsolutions correspond to a substitution of the trivalent rareearth elements (REE3+) and Si4+ for Ca2+ and P5+. The REE substitution is accompanied by a change in volatile composition with F-rich apatite and Cl-rich britholite indicating that Si and Cl-rich hydrothermal fluids are present at the late stage of carbonatite evolution leading to REEenrichment and the crystallization of REE minerals.
DS1990-0217
1990
Bodinier, J.-L.Bodinier, J.-L., Menzies, M.A., Thirwall, M.Elemental and isotopic geochemistry of the Lanzo Lherzolite Massif:implications for the temporal evolution of the Morb sourceTerra, Abstracts of International Workshop Orogenic Lherzolites and Mantle Processes, Vol. 2, December abstracts p. 126ItalyLherzolite, Geochemistry
DS200412-0477
2004
Bodinier, J-L.Downes, H., Macdonald, R., Upton, B.G.J., Cox, K.G., Bodinier, J-L., Mason, P.R.D., James, D., Hill, P.G., HeaUltramafic xenoliths from the Bearpaw Mountains, Montana: USA: evidence for multiple metasomatic events in the lithospheric mantJournal of Petrology, Vol. 45, 8, pp. 1631-1662.United States, MontanaMetasomatism
DS200712-0603
2007
Bodinier, J-L.Le Roux, V., Bodinier, J-L., Alard, O., Wieland, P., O'Reilly, S.Y.Insights into refertilization processes in lithospheric mantle from integrated isotopic studies in the Lherz Massif.Plates, Plumes, and Paradigms, 1p. abstract p. A563.Europe, FranceMelting
DS200712-0604
2007
Bodinier, J-L.Le Roux, V., Bodinier, J-L., Tommasi, A., Alard, O., Dautria, J-M., Vauchez, A., Riches, A.J.V.The lherz spinel lherzolite: refertilized rather than pristine mantle.Earth and Planetary Science Letters, Vol. 259, 3-4, pp. 599-612.MantleLherzolite chemistry
DS200712-0605
2007
Bodinier, J-L.Le Roux, V., Bodinier, J-L., Tommasi, A., Alard, O., Dautria, J-M., Vauchez, A., Riches, A.J.V.The lherz spinel lherzolite: refertilized rather than pristine mantle.Earth and Planetary Science Letters, Vol. 259, 3-4, pp. 599-612.MantleLherzolite chemistry
DS200712-0895
2007
Bodinier, J-L.Riches, A.J.V., Rogers, N.W., Charlier, B.L.A., Bodinier, J-L.A reappraisal of the petrology and origins of the Lherz peridotite.Plates, Plumes, and Paradigms, 1p. abstract p. A838.EuropeMantle composition
DS200912-0429
2009
Bodinier, J-L.Le Roux, V., Bodinier, J-L., Allard, O., O'Reilly, S.Y., Griffin, W.L.Isotopic decoupling during porous melt flow: a case study in the Lherz peridotite.Earth and Planetary Science Letters, Vol. 279, 1-2, pp.76-85.Europe, FranceGeochronology
DS201012-0473
2010
Bodinier, J-L.Marchesi, C., Griffin, W.L., Garrido, C.J., Bodinier, J-L., O'Reilly, S.Y., Pearson, N.J.Persistence of mantle lithospheric Re-Os signature during asthenospherization of the subcontinental lithospheric mantle: insights in situ sulphides....Contributions to Mineralogy and Petrology, Vol. 159, 3, pp. 315-330.Europe, SpainRonda peridotite
DS201312-0574
2013
Bodinier, J-L.Marchesi, C., Garrido, C.J., Bosch, D., Bodinier, J-L., Gervilla, F., Hidas, K.Mantle refertilization by melts of crustal derived garnet pyroxenite: evidence from the Ronda Peridotite massif, southern Spain.Earth and Planetary Interiors, Vol. 362, pp. 66-75.Europe, SpainRonda - pyroxenite. Melts
DS201412-0478
2014
Bodinier, J-L.Kourim, F., Bodinier, J-L., Alard, O., Bendaoud, A., Vauchez, A., Dautria, J-M.Nature and evolution of the lithospheric mantle beneath the Hoggar Swell ( Algeria): a record from mantle xenoliths.Journal of Petrology, Vol. 55, pp. 2249-2280.Africa, AlgeriaXenoliths
DS201412-0548
2014
Bodinier, J-L.Marchesi, C., Dale, C.W., Garrdo, C.J., Pearson, D.G., Bosch, D., Bodinier, J-L., Gervilla, F., Hidas, K.Fractionation of highly siderophile elements in refertilized mantle: implications for the Os isotope composition of basalts.Earth and Planetary Science Letters, Vol. 400, pp. 33-44.MantleRonda peridotite
DS201704-0650
2016
Bodinier, J-L.Varas-Reu, M.I., Garrido, C.J., Marchesi, C., Bodinier, J-L., Frets, E., Bosch, D., Tommasi, A., Hidas, K., Targuisti, K.Refertilization processes of the subcontinental lithospheric mantle: the record of the Beni Bousera orogenic peridotite ( Rif Belt, northern Morocco).Journal of Petrology, Vol. 57, 11-12, pp. 2251-2270.Africa, MoroccoDeposit - Beni Bousera

Abstract: Correlations between major and minor transition elements in tectonically emplaced orogenic peridotites have been ascribed to variable degrees of melt extraction and melt-rock reaction processes, leading to depletion or refertilization. To elucidate how such processes are recorded in the subcontinental lithospheric mantle, we processed a large geochemical dataset for peridotites from the four tectono-metamorphic domains of the Beni Bousera orogenic massif (Rif Belt, northern Morocco). Our study reveals that variations in bulk-rock major and minor elements, Mg-number and modal mineralogy of lherzolites, as well as their clinopyroxene trace element compositions, are inconsistent with simple partial melting and mainly resulted from different reactions between melts and depleted peridotites. Up to 30% melting at <3 GPa and cryptic metasomatism can account for the geochemical variations of most harzburgites. In Grt-Sp mylonites, melting and melt-rock reactions are masked by tectonic mixing with garnet pyroxenites and subsolidus re-equilibration. In the rest of the massif, lherzolites were mostly produced by refertilization of a refractory protolith (Mg-number = 91, Ol = 70%, Cpx/Opx = 0.4) via two distinct near-solidus, melt- rock reactions: (1) clinopyroxene and orthopyroxene precipitation and olivine consumption at melt/rock ratios <0.75 and variable mass ratio between crystallized minerals and infiltrated melt ®, which are recorded fairly homogeneously throughout the massif; (2) dissolution of orthopyroxene and precipitation of clinopyroxene and olivine at melt/rock ratios <1 and R = 0.2-0.3, which affected mainly the Arie` gite-Seiland and Seiland domains. The distribution of secondary lherzolites in the massif suggests that the first refertilization reaction occurred prior to the differentiation of the Beni Bousera mantle section into petro-structural zones, whereas the second reaction was associated with the development of the tectono-metamorphic domains. Our data support a secondary, refertilization-related origin for most lherzolites in orogenic peridotite massifs.
DS201706-1063
2017
Bodinier, J-L.Bianchini, G., Bodinier, J-L., Braga, R., Wilson, M.Crust-mantle and lithosphere-Asthenosphere boundaries.Geological Society of America, SPE 526, 200p.Mantlebook
DS201707-1314
2016
Bodinier, J-L.Chetouani, K., Bodinier, J-L., Garrido, C.J., Marchesi, C., Amri, I., Targuisti, K.Spatial variability of pyroxenite layers in the Beni Bousera orogenic peridotite ( Morocco) and implications for their origin.Comptes Rendus Geoscience, Vol. 348, pp. 619-629.Africa, Moroccoperidotite

Abstract: The Beni Bousera peridotite contains a diversity of pyroxenite layers. Several studies have postulated that at least some of them represent elongated strips of oceanic lithosphere recycled in the convective mantle. Some pyroxenites were, however, ascribed to igneous crystal segregation or melt–rock reactions. To further constrain the origin of these rocks, we collected 171 samples throughout the massif and examined their variability in relation with the tectono-metamorphic domains. A major finding is that all facies showing clear evidence for a crustal origin are concentrated in a narrow corridor of mylonitized peridotites, along the contact with granulitic country rocks. These peculiar facies were most likely incorporated at the mantle–crust boundary during the orogenic events that culminated in the peridotite exhumation. The other pyroxenites derive from a distinct protolith that was ubiquitous in the massif before its exhumation. They were deeply modified by partial melting and melt–rock reactions associated with lithospheric thinning.
DS201708-1567
2017
Bodinier, J-L.Blanchini, G., Bodinier, J-L., Braga, R., Wilson, M.The crust mantle and lithosphere-asthenosphere boundaries: insights from xenoliths, orogenic deep sections, and geophysical studies. 2 Chapters citedGeological Society of London, book - cost approx. 43 lbsMantlexenoliths
DS201904-0744
2019
Bodinier, J-L.Hidas, K., Garrido, C.J., Booth-Rea, G., Marchesi, C., Bodinier, J-L., Dautria, J-M., Louni-Hacini, A., Azzouni-Sekkal, A.Lithosphere tearing along STEP faults and synkenetic formation of lherzolite and wehrlite in the shallow subcontinental mantle. OranSolid Earth, https://doi.org/10.5194 /se-2019-32 36p.Mantle, Africa, Algeriasubduction

Abstract: Subduction-Transform Edge Propagator (STEP) faults are the locus of continual lithospheric tearing at slab edges, resulting in sharp changes in the lithospheric and crustal thickness and triggering lateral and/or near-vertical mantle flow. However, the mechanisms at the lithospheric mantle scale are still poorly understood. Here, we present the microstructural study of olivine-rich lherzolite, harzburgite and wehrlite mantle xenoliths from the Oran volcanic field (Tell Atlas, NW Algeria). This alkali volcanic field occurs along a major STEP fault responsible for the Miocene westward slab retreat in the westernmost Mediterranean. Mantle xenoliths provide a unique opportunity to investigate the microstructures in the mantle section of a STEP fault system. The microstructures of mantle xenoliths show a variable grain size ranging from coarse granular to fine-grained equigranular textures uncorrelated with modal variations. The major element composition of the mantle peridotites provides temperature estimates in a wide range (790-1165?°C) but in general, the coarse-grained and fine-grained peridotites suggest deeper and shallower provenance depth, respectively. Olivine grain size in the fine-grained peridotites depends on the size and volume fraction of the pyroxene grains, which is consistent with pinning of olivine grain growth by pyroxenes as second phase particles. In the coarse-grained peridotites, well-developed olivine crystal preferred orientation (CPO) is characterized by orthorhombic and [100]-fiber symmetries, and orthopyroxene has a coherent CPO with that of olivine, suggesting their coeval deformation by dislocation creep at high-temperature. In the fine-grained microstructures, along with the weakening of the fabric strength, olivine CPO symmetry exhibits a shift towards [010]-fiber and the [010]- and [001]-axes of orthopyroxene are generally distributed subparallel to those of olivine. These data are consistent with deformation of olivine in the presence of low amounts of melts and the precipitation of orthopyroxenes from a melt phase. The bulk CPO of clinopyroxene mimics that of orthopyroxene via a topotaxial relationship of the two pyroxenes. This observation points to a melt-related origin of most clinopyroxenes in the Oran mantle xenoliths. The textural and geochemical record of the peridotites are consistent with interaction of a refractory harzburgite protolith with a high-Mg# melt at depth (resulting in the formation of coarse-grained clinopyroxene-rich lherzolite and wehrlite), and with a low-Mg# evolved melt in the shallow subcontinental lithospheric mantle (forming fine-grained harzburgite). We propose that pervasive melt-peridotite reaction - promoted by lateral and/or near-vertical mantle flow associated with lithospheric tearing - resulted in the synkinematic crystallization of secondary lherzolite and wehrlite and played a key effect on grain size reduction during the operation of the Rif-Tell STEP fault. Melt-rock reaction and secondary formation of lherzolite and wehrlite may be widespread in other STEP fault systems worldwide.
DS201909-2034
2019
Bodinier, J-L.Djeddi, A., Parat, F., Bodinier, J-L., Ouzegane, K. Immiscibility and hybridization during progressive cooling of carbonatite and alkaline magmas ( in Oussal Terrane, western Hoggar).Goldschmidt2019, 1p. AbstractAfrica, Algeriacarbonatite

Abstract: Carbonatites and syenites from Ihouhaouene (2 Ga; In Ouzzal terrane, Hoggar, South of Algeria) have close spatial relationships. Their analogous mineral assemblages with diopside/hedenbergite (cpx), apatite, wollastonite +/- calcite and alkali-feldspar suggest that they were emplaced from a common igneous parental event. Carbonatites from In Ouzzal terrane are calciocarbonatites and form a continuous range of whole-rock major and trace element composition from Sipoor carbonatite (<20 wt.% SiO2; 24-36 wt.% CO2) to Si-rich carbonatite (20-35 wt.% SiO2; 11-24 wt.% CO2) then white syenite (52-58 wt.% SiO2; 0.1-6.5 wt.% CO2) and red syenite (57-65 wt.% SiO2; 0.1-0.4 wt.% CO2). Equilibrium calculations reveal that apatite (Ce/Lu= 1690-6182; Nb/Ta >50) and cpx (Ce/Lu= 49-234; Nb/Ta<10) from Si-rich carbonatites and white syenites crystallized from a REEenriched carbonate melt and an evolved silicate melt, respectively. Likewise, Si-poor carbonatites have a higher REE contents in calculated apatite equilibrium melts than in their cpx and a wide range of Nb/Ta ratios with a majority of subchondritic value (<10) that reflects the segregation of the carbonate fraction from an evolved parental melt. Otherwise, red syenites have similar REE contents in apatite and clinopyroxene equilibrium melts (Nb/Ta>10) suggesting an origin from homogeneous evolved melt batches. Both mineralogical and geochemical features reveal the intimate link between carbonatites and syenites and their cogenetic signature. Immiscibility and fractional crystallization processes modelling explain the trace element contents and low Nb/Ta ratio in minerals. These processes were partly counterbalanced by intermingling of partially crystallized melt fractions and hybridization of segregated minerals during the progressive cooling of a silico-carbonated mantle melt.
DS200512-0463
2005
Bodinier, J-L.et.al.Ionov, D.A., Prikhodko, V.S., Bodinier, J-L.et.al.Lithospheric mantle beneath the south eastern Siberian Craton: petrology of peridotite xenoliths in basalts from the Tokinsky Stanovik.'Contributions to Mineralogy and Petrology, Online AccessRussiaXenoliths, Aldan Shield, Siberian Craton, metasomatism
DS1991-0136
1991
Bodnar, R.J.Bodnar, R.J., Costain, J.K.Effect of varying fluid composition on mass and energy transport in theearth's crustGeophysical Research Letters, Vol. 18, No. 5, May pp. 983-986GlobalMantle, Fluid composition
DS1994-1862
1994
Bodnar, R.J.Vityk, M.O., Bodnar, R.J., Schmidt, C.S.Fluid inclusions as tectonothermomobarometers: relation between P-T history and reequilibrium morphologyGeology, Vol. 22, No. 8, August pp. 731-734GlobalGeothermometry, Crustal thickening
DS1995-1864
1995
Bodnar, R.J.Szabo, C., Bodnar, R.J.Silicate rich metasomatic melt in the Upper Mantle beneath the Nograd-Gomor volcanic field.Eos, Abstracts, Vol. 76, No. 17, Apr 25, p. S 268.Hungary, SlovakiaMelt inclusions, Mantle xenoliths
DS1995-2003
1995
Bodnar, R.J.Vityk, M.O., Bodnar, R.J., Dudok, I.V.Natural and synthetic re-equilibration textures of fluid inclusions in quartz (Marmarosh diamonds)refill-European Journ. of Mineralogy, No. 5, pp. 1071-1088.GlobalQuartz - imitation diamonds
DS1996-1395
1996
Bodnar, R.J.Szabo, Cs., Bodnar, R.J.Changing magma ascent rates in the Nograd Gomor volcanic field... mantlexenoliths.Petrology, Vol. 4, No. 3, pp. 221-230.Hungary, SlovakiaMantle xenoliths, Geochronology -magma
DS1996-1396
1996
Bodnar, R.J.Szabo, Cs., Bodnar, R.J.Changing magma ascent rates in the Nograd Gomor volcanic field northernHungary/Slovakia... xenolithsPetrology, Vol. 4, No. 3, pp. 221-230Hungary, SlovakiaXenoliths, Magma
DS1996-1486
1996
Bodnar, R.J.Vityk, M.O., Bodnar, R.J., Dudok, I.V.Fluid inclusions in Marmarosh diamonds: evidence for tectonic history Of the folded Carpathian Mountains.Tectonophysics, Vol. 255, No. 1-2, April 20, pp. 163-UKraineMarmarosh - not diamonds, Tectonics
DS1998-1437
1998
Bodnar, R.J.Szabo, C., Bodnar, R.J.Fluid inclusion evidence for an upper mantle origin for green clinopyroxenes in late Cenozooic basanites....International Geology Review, Vol. 40, No. 9, Sept. pp. 765-74.Hungary, SlovakiaGeochronology, Nograd Gomor volcanic field
DS2000-0944
2000
Bodnar, R.J.Szabo, Cs., Bodnar, R.J.Fluid inclusion evidence for an upper mantle origin for green clinopyroxene in Late Cenozoic basanites....Snyder, Neal, Ernst, Plan. Petrology and Geochemistry, pp. 83-91.Hungary, SlovakiaBasanite
DS2003-0326
2003
Bodnar, R.J.De Vivo, B., Bodnar, R.J.Melt inclusions in volcanic systemshttp://www.elsevier.com/inca/publications/store/6/7/2/8/0/7/672807.pub.htt, 272p. approx. $ 115.GlobalBook - liquid to glass, magma degassing, melt inclusion
DS2003-0327
2003
Bodnar, R.J.De Vivo, B., Bodnar, R.J.Melt inclusions in volcanic systemsElsevier Developments in Volcanology, 5, 272p. $ 115. www.elsevier.com/inca/publications/store/MantleBook
DS200412-0428
2003
Bodnar, R.J.De Vivo, B., Bodnar, R.J.Melt inclusions in volcanic systems.Elsevier, 272p. approx. $ 115.TechnologyBook - liquid to glass, magma degassing, melt inclusion
DS200512-0098
2005
Bodnar, R.J.Bodnar, R.J.Fluids in planetary systems.Elements, Vol. 1, 1, Jan. pp. 9-12.MantleFluid inclusions, deformation, volcanoes
DS200612-0143
2006
Bodnar, R.J.Bodnar, R.J.Fluid and melt inclusion evidence for immiscibility in nature.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 29, abstract only.MantleMelting
DS200712-0043
2006
Bodnar, R.J.Azbej, T., Szabo, C., Bodnar, R.J., Dobosi, G.Genesis of carbonate aggregates in lamprophyres from the northeastern Transnubian central range, Hungary: magmatic or hydrothermal origin?Mineralogy and Petrology, Vol. 88, 3-4, pp. 479-497.Europe, HungaryLamprophyre - not specific to diamonds
DS200812-0121
2008
Bodnar, R.J.Bodnar, R.J., Azbej, T., Becker, S., Cannatelli, C., Fall, A., Hole, J., Severs, M.The whole Earth geohydrologic cycle.Goldschmidt Conference 2008, Abstract p.A91.MantleWater
DS201312-0401
2014
Bodnar, R.J.Howarth, G.H., Barry, P.H., Pernet-Fisher, J.F., Baziotis, I.P., Pokhilenko, N.P., Pokhilenko, L.N., Bodnar, R.J., Taylor, L.A.Superplume metasomatism: evidence from Siberian mantle xenoliths.Lithos, Vol. 184-187, pp. 209-224.Russia, SiberiaMetasomatism
DS201412-0101
2014
Bodnar, R.J.Carmody, L., Taylor, L.A., Thaisen, K.G., Tychkov, N., Bodnar, R.J., Sobolev, N.V., Poikhilenko, L.N., Poikilenko, N.P.Ilmenite as a diamond indicator mineral in the Siberian craton: a tool to predict diamond potential.Economic Geology, Vol. 109, no. 3, pp. 775-783.RussiaIlmenite, chemistry
DS201412-0676
2014
Bodnar, R.J.Pernet-Fisher, J.F., Howarth, G.H., Liu, Y., Barry, P.H., Carmody, L., Valley, J.W., Bodnar, R.J., Spetsius, Z.V., Taylor, L.A.Komsomolskaya Diamondiferous eclogites: evidence for oceanic crustal protoliths.Contributions to Mineralogy and Petrology, Vol. 167, pp. 1-17.Russia, SiberiaDeposit - Komsomolskaya
DS201412-1004
2014
Bodnar, R.J.Yardley, B.W.D., Bodnar, R.J.Fluids in the continental crustGeochemical Perspectives Letters, Vol. 3, 1, pp. 1-127.MantleChemistry
DS201610-1874
2016
Bodnar, R.J.Jean, M.M., Taylor, L.A., Howarth, G.H., Peslier, A.H., Fedele, L., Bodnar, R.J., Guan, Y., Doucet, L.S., Ionov, D.A., Logvinova, A.M., Golovin, A.V., Sobolev, N.V.Olivine inclusions in Siberian diamonds and mantle xenoliths: contrasting water and trace -element contents.Lithos, in press available 11p.Russia, SiberiaDiamond inclusions
DS201904-0759
2018
Bodnar, R.J.Moore, L.R., Bodnar, R.J.A pedagogical approach to estimating the CO2 budget of magmas.Journal of the Geological Society of London, Vol. 176, pp. 398-407.Mantlecarbon

Abstract: On a planetary scale, the carbon cycle describes the movement of carbon between the atmosphere and the deep earth, which affects petrologic processes in a range of geologic settings and the long-term viability of life at the surface. In this context, volcanoes and their associated magmatic systems represent the interface through which carbon is transferred from the deep earth to the atmosphere. Thus, describing the CO2 budget of volcanic systems is necessary for understanding the deep carbon cycle. In this review, Kilauea volcano (Hawaii) is used as a case study, and we present several simple calculations that can be used to account for processes that affect the amount and distribution of CO2 in this relatively well-studied volcanic system. These processes include estimating the concentration of CO2 in a melt derived by partial melting of a source material, enrichment of CO2 in the melt during fractional crystallization, exsolution of CO2 from a fluid-saturated melt, trapping and post-entrapment modification of melt inclusions, and degassing from the volcanic edifice. Our goal in this review is to provide straightforward example calculations that can be used to derive first-order estimates regarding processes that control the CO2 budgets of magmas.
DS201905-1038
2019
Bodnar, R.J.Guzmics, T., Berkesi, M., Bodnar, R.J., Fall, A., Bali, E., Milke, R., Vetlenyi, E., Szabo, C.Natrocarbonatites: a hidden product of three phase immiscibility. ( Oldoinyo Lengai)Geology, https://doi.org/ 10.1130/G46125.1 Africa, Tanzaniacarbonatite

Abstract: Earth’s only active natrocarbonatite volcanism, occurring at Oldoinyo Lengai (OL), Tanzania, suggests that natrocarbonatite melts are formed through a unique geological process. In the East African Rift, the extinct Kerimasi (KER) volcano is a neighbor of OL and also contains nephelinites hosting melt and fluid inclusions that preserve the igneous processes associated with formation of natrocarbonatite melts. Here, we present evidence for the presence of coexisting nephelinite melt, fluorine-rich carbonate melt, and alkali carbonate fluid. The compositions of these phases differ from the composition of OL natrocarbonatites; therefore, it is unlikely that natrocarbonatites formed directly from one of these phases. Instead, mixing of the outgassing alkali carbonate fluid and the fluorine-rich carbonate melt can yield natrocarbonatite compositions at temperatures close to subsolidus temperatures of nephelinite (<630-650 °C). Moreover, the high halogen content (6-16 wt%) in the carbonate melt precludes saturation of calcite (i.e., formation of calciocarbonatite) and maintains the carbonate melt in the liquid state with 28-41 wt% CaO at temperatures ?600 °C. Our study suggests that alkali carbonate fluids and melts could have commonly formed in the geological past, but it is unlikely they precipitated calcite that facilitates fossilization. Instead, alkali carbonates likely precipitated that were not preserved in the fossil nephelinite rocks. Thus, alkali carbonate fluids and melts have been so far overlooked in the geological record because of the lack of previous detailed inclusion studies.
DS201906-1298
2019
Bodnar, R.J.Guzmics, T., Berkesi, M, Bodnar, R.J., Fall, A., Bali, E., Milke, R., Vetlenyi, E., Szabo, C.Natrocarbonatites: a hidden product of three phase immiscibility.Geology, Vol. 47, 6, pp. 527-530.Africa, Tanzaniadeposit - Oldoinyo Lengai

Abstract: Earth’s only active natrocarbonatite volcanism, occurring at Oldoinyo Lengai (OL), Tanzania, suggests that natrocarbonatite melts are formed through a unique geological process. In the East African Rift, the extinct Kerimasi (KER) volcano is a neighbor of OL and also contains nephelinites hosting melt and fluid inclusions that preserve the igneous processes associated with formation of natrocarbonatite melts. Here, we present evidence for the presence of coexisting nephelinite melt, fluorine-rich carbonate melt, and alkali carbonate fluid. The compositions of these phases differ from the composition of OL natrocarbonatites; therefore, it is unlikely that natrocarbonatites formed directly from one of these phases. Instead, mixing of the outgassing alkali carbonate fluid and the fluorine-rich carbonate melt can yield natrocarbonatite compositions at temperatures close to subsolidus temperatures of nephelinite (<630-650 °C). Moreover, the high halogen content (6-16 wt%) in the carbonate melt precludes saturation of calcite (i.e., formation of calciocarbonatite) and maintains the carbonate melt in the liquid state with 28-41 wt% CaO at temperatures ?600 °C. Our study suggests that alkali carbonate fluids and melts could have commonly formed in the geological past, but it is unlikely they precipitated calcite that facilitates fossilization. Instead, alkali carbonates likely precipitated that were not preserved in the fossil nephelinite rocks. Thus, alkali carbonate fluids and melts have been so far overlooked in the geological record because of the lack of previous detailed inclusion studies.
DS201907-1546
2019
Bodnar, R.J.Gorce, J.S., Caddick, M.J., Bodnar, R.J.Thermodynamic contraints on carbonate stability and carbon volatility during subduction.Earth and Planetary Science Letters, Vol. 519, pp. 213-222.Mantlecarbon cycle

Abstract: The breakdown of carbonate minerals at high pressure is frequently cited as an important mechanism that leads to carbon release from subducted rocks. However, carbonate minerals in the subducting slab are predicted to be stable to depths that are greater than arc-generating magma depths of approximately 150 km, implying that breakdown of carbonate phases in dehydrated MORB may not be a major contributor to arc volcano carbon budgets. To account for this discrepancy, previous studies have suggested that addition of H2O-rich fluids promotes the breakdown of carbonate-rich lithologies, thus generating volatile C species that could be incorporated into arc magmas. Here, we explore the feasibility of H2O-mediated decarbonation with a simple thermodynamic model. We calculate equilibrium mineral assemblages and accompanying fluid H2O/CO2 ratios for typical subducted lithologies, assuming a range of subduction zone geotherms, and explore the implications of addition of external fluids that are generated from deserpentinization of ultramafic lithologies at various stages. Results suggest that the liberation of C along volcanic arcs is facilitated by either the breakdown of carbonate minerals due to thermodynamically favorable conditions in hotter subduction systems, or by the breakdown of carbonate minerals during periods of higher fluid productivity associated with deserpentinization at appropriate depths along colder subduction geotherms. A comparison of C fluxes measured at volcanic arcs shows that colder subduction zones generate higher C fluxes, implying that the depth at which deserpentinization reactions occur strongly controls the availability of aqueous fluids for slab decarbonation, and that fluid availability represents the dominant control on carbon volatility during subduction.
DS202006-0912
2020
Bodnar, R.J.Bodnar, R.J., Frezzotti, M.L.Microscale chemistry: raman analysis of fluid and melt inclusions.Elements, Vol. 16, pp. 93-98.Mantlemelt inclusions

Abstract: Raman spectroscopy is a commonly applied nondestructive analytical technique for characterizing fluid and melt inclusions. The exceptional spatial resolution (~1 µm) and excellent spectral resolution (?1 cm?1) permits the characterization of micrometer-scale phases and allows quantitative analyses based on Raman spectral features. Data provided by Raman analysis of fluid and melt inclusions has significantly advanced our understanding of complex geologic processes, including preeruptive volatile contents of magmas, the nature of fluids in the deep crust and upper mantle, the generation and evolution of methane-bearing fluids in unconventional hydrocarbon reservoirs. Anticipated future advances include the development of Raman mass spectroscopy and the use of Raman to monitor reaction progress in synthetic and natural fluid inclusion microreactors.
DS202007-1125
2020
Bodnar, R.J.Berkesi, M., Bali, E., Bodnar, R.J., Szabo, A., Guzmics, T.Carbonatite and highly peralkaline nephelinitie melts from Oldoinyo Lengai volcano, Tanzania: the role of natrite-normative fluid degassing.Gondwana Research, Vol. 85, pp. 76-83. pdfAfrica, Tanzaniadeposit - Oldoinyo Lengai

Abstract: Oldoinyo Lengai, located in the Gregory Rift in Tanzania, is a world-famous volcano owing to its uniqueness in producing natrocarbonatite melts and because of its extremely high CO2 flux. The volcano is constructed of highly peralkaline [PI = molar (Na2O + K2O)/Al2O3 > 2-3] nephelinite and phonolites, both of which likely coexisted with carbonate melt and a CO2-rich fluid before eruption. Results of a detailed melt inclusion study of the Oldoinyo Lengai nephelinite provide insights into the important role of degassing of CO2-rich vapor in the formation of natrocarbonatite and highly peralkaline nephelinites. Nepheline phenocrysts trapped primary melt inclusions at 750-800 °C, representing an evolved state of the magmas beneath Oldoinyo Lengai. Raman spectroscopy, heating-quenching experiments, low current EDS and EPMA analyses of quenched melt inclusions suggest that at this temperature, a dominantly natritess-normative, F-rich (7-14 wt%) carbonate melt and an extremely peralkaline (PI = 3.2-7.9), iron-rich nephelinite melt coexisted following degassing of a CO2 + H2O-vapor. We furthermore hypothesize that the degassing led to re-equilibration between the melt and liquid phases that remained and involved 1/ mixing between the residual (after degassing) alkali carbonate liquid and an F-rich carbonate melt and 2/ enrichment of the coexisting nephelinite melt in alkalis. We suggest that in the geological past similar processes were responsible for generating highly peralkaline silicate melts in continental rift tectonic settings worldwide.
DS202105-0798
2021
Bodnar, R.J.Wallace, P.J., Plank, T., Bodnar, R.J., Gaetani, G.A., Shea, T.Olivine-hosted melt inclusions: a microscopic perspective on a complex magmatic world.Annual Review of Earth Planetary Sciences, Vol. 49, pp. 465-484.MantleMagmatism

Abstract: Inclusions of basaltic melt trapped inside of olivine phenocrysts during igneous crystallization provide a rich, crystal-scale record of magmatic processes ranging from mantle melting to ascent, eruption, and quenching of magma during volcanic eruptions. Melt inclusions are particularly valuable for retaining information on volatiles such as H2O and CO2 that are normally lost by vesiculation and degassing as magma ascends and erupts. However, the record preserved in melt inclusions can be variably obscured by postentrapment processes, and thus melt inclusion research requires careful evaluation of the effects of such processes. Here we review processes by which melt inclusions are trapped and modified after trapping, describe new opportunities for studying the rates of magmatic and volcanic processes over a range of timescales using the kinetics of post-trapping processes, and describe recent developments in the use of volatile contents of melt inclusions to improve our understanding of how volcanoes work.
DS202107-1144
2021
Bodnar, R.J.Wallace, P.J., Plank, T., Bodnar, R.J., Gaetani, G.A., Shea, T.Olivine-hosted melt inclusions: a microscopic perspective on a complex magmatic world.Annual Review of Earth and Planetary Sciences, Vol. 49, pp. 465-494.Mantlemagmatism

Abstract: Inclusions of basaltic melt trapped inside of olivine phenocrysts during igneous crystallization provide a rich, crystal-scale record of magmatic processes ranging from mantle melting to ascent, eruption, and quenching of magma during volcanic eruptions. Melt inclusions are particularly valuable for retaining information on volatiles such as H2O and CO2 that are normally lost by vesiculation and degassing as magma ascends and erupts. However, the record preserved in melt inclusions can be variably obscured by postentrapment processes, and thus melt inclusion research requires careful evaluation of the effects of such processes. Here we review processes by which melt inclusions are trapped and modified after trapping, describe new opportunities for studying the rates of magmatic and volcanic processes over a range of timescales using the kinetics of post-trapping processes, and describe recent developments in the use of volatile contents of melt inclusions to improve our understanding of how volcanoes work. Inclusions of silicate melt (magma) trapped inside of crystals formed by magma crystallization provide a rich, detailed record of what happens beneath volcanoes. These inclusions record information ranging from how magma forms deep inside Earth to its final hours as it ascends to the surface and erupts. The melt inclusion record, however, is complex and hazy because of many processes that modify the inclusions after they become trapped in crystals. Melt inclusions provide a primary archive of dissolved gases in magma, which are the key ingredients that make volcanoes erupt explosively.
DS201412-0373
2014
Bodnar, R.L.Howarth, G.H., Barry, P.H., Pernet-Fisher, J.F., Baziotis, I.P., Pokhilenko, N.P., Poikhilenko, L.N., Bodnar, R.L., Taylor, L.A., Agashev, A.M.Superplume metasomatism: evidence from Siberian mantle xenoliths.Lithos, Vol. 184-187, pp. 209-224.RussiaMetasomatism
DS2002-1581
2002
Bodner, R.J.Taylor, L.A., Sobolev, N..V., Ghazi, M., Anand, M., Bodner, R.J.The science of diamonds and their inclusions can such dat a be used to establish diamond provenance?Eos, American Geophysical Union, Spring Abstract Volume, Vol.83,19, 1p.BrazilDiamond - inclusions, sulphides
DS1999-0078
1999
Bodorkos, S.Bodorkos, S., Oliver, N.H.S., Cawood, P.A.Thermal evolution of the central Halls Creek Orogen, northern AustraliaAustralian Journal of Earth Sciences, Vol. 46, June pp. 453-466.AustraliaGeothermometry, Halls Creek Orogen
DS2002-0178
2002
Bodorkos, S.Bodorkos, S., Sandiford, M., Oliver, N.H.S., Cawood, P.High T low P metamorphism in the Paleoproterozoic Halls Creek Orogen: the middle crustal response to mantle...Journal of Metamorphic Geology, Vol. 20, No. 2, pp. 217-38.Australia, northernGeothermometry - mantle related transient thermal pulse
DS200512-0099
2004
Bodorkos, S.Bodorkos, S., Reddy, S.M.Proterozoic cooling and exhumation of the northern central Halls Creek Orogen, Western Australia: constraints from a reconnaissance 40 Ar 39 Ar study.Australia Journal of Earth Sciences, Vol. 51, 4, pp. 591-609.AustraliaGeochronology
DS200612-0144
2005
Bodorkos, S.Bodorkos, S., Sandiford, M.Thermal and mechanical controls on the evolution of Archean crustal deformation: examples from western Australia.Benn, K., Mareschal, J-C., Condie, K.C. Archean Geodynamics and Environments, AGU Geophysical Monograph, No. 164, pp. 131-148.AustraliaGeothermometry
DS1991-0246
1991
Bodri, L.Cermak, V., Bodri, L.A heat production model of the crust and upper mantleTectonophysics, Vol. 194, No. 4, August 10, pp. 307-324GlobalMantle, Heat flow
DS1991-0247
1991
Bodri, L.Cermak, V., Bodri, L., Rybach, L.Radioactive heat production in the continental crust and its depthdependenceTerrestrial Heat Flow and the Lithosphere Structure, editors Cermak, V. and, Springer Verlag, pp. 23-69MantleCrust -hot spots, Depth
DS1992-0228
1992
Bodri, L.Cermak, V., Bodri, L.Crustal thinning during rifting: a possible signature in radiogenic heatproductionTectonophysics, Vol. 209, pp. 227-239MantleHot spots, Rift zones
DS1991-0924
1991
Bodrov, V.A.Kostrovitsky, S.I., Skripnichenko, V.A., Plusnin, G.S., Bodrov, V.A.Strontium, Carbon, and Oxygen isotope composition in kimberlites of the North Russian. USSRProceedings of Fifth International Kimberlite Conference held Araxa June, pp. 527-529RussiaGeochronology, Analyses
DS1975-1252
1979
Bodunov, YE.N.Vdovykin, G.P., Bodunov, YE.N., et al.Bitumens in the Mir Kimberlite PipeDoklady Academy of Sciences USSR, EARTH SCI. SECTION., Vol. 245, No. 1-6, PP. 206-210.RussiaBlank
DS202205-0682
2022
Bodur, O.F.Flament, N., Meredith, A., Bodur, O.F., Williams, S. Volcanoes, diamonds and blobs.The Conversation.com, Mar. 31, 5p.Mantlediamond genesis
DS2003-0663
2003
Boebel, T.Jokat, W., Boebel, T., Konig, M., Meyer, U.Timing and geometry of early Gondwana breakupJournal of Geophysical Research, Vol. 108, B9, Sept. 16, 10.1029/2002JB001802RodiniaTectonics
DS200412-0922
2003
Boebel, T.Jokat, W., Boebel, T., Konig, M., Meyer, U.Timing and geometry of early Gondwana breakup.Journal of Geophysical Research, Vol. 108, B9, Sept. 16, 10.1029/2002 JB001802Gondwana, RodiniaTectonics
DS1910-0263
1912
Boediker, C.Boediker, C.Die Verwertung der Suedwest afrikanischen DiamantenBerlin: Deutschen Kanzlei, 23P.Southwest Africa, South Africa, NamibiaHistory, Production, Mining Economics, Kimberley
DS1993-1809
1993
Boehler, R.Zerr, A., Boehler, R.Melting of (MgFe)SiO2 perovskite to 625 kilobars: indication of a high melting temperature in the lower mantle.Science, Vol. 262, No. 5133, October 22, pp. 553-554.MantleMelting, Perovskite
DS1994-1971
1994
Boehler, R.Yuen, D.A., Cadek, O.P., Boehler, R., et al.Large cold anomalies in the deep mantle and mantle instability in theCretaceous.Terra Nova, Vol. 6, pp. 238-245.MantleGeophysics -seismics, Tomography
DS1995-0163
1995
Boehler, R.Boehler, R., Chopelas, A., Zarr, A.Temperature and chemistry of the core-mantle boundaryChemical Geology, Vol. 120, No. 3-4, March 1, pp. 199-206.MantleBoundary, Geochemistry
DS1998-0135
1998
Boehler, R.Boehler, R., Zerr, A., Serghiou, Tschauner, HilgrenNew experimental constraints on the nature of DMineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 182-3.MantleCore mantle boundary layer, Perovskite
DS1998-0619
1998
Boehler, R.Hillgren, V.J., Boehler, R.high pressure reactions between light metals and silicates; Implications for the light element ....Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 624-5.MantleCore-mantle boundary, light rare earth element (LREE).
DS2001-0191
2001
Boehler, R.Chudinovskikh, L., Boehler, R.high pressure polymorphs of olivine and the 660 km seismic discontinuityNature, Vol. No. 6837, pp. 574-6.MantleBoundary
DS2002-0179
2002
Boehler, R.Boehler, R., Chudinovskikh, L., Hilgren, V.Earth's core and lower mantle: phase behaviour melting and chemical interactionsProceedings - International School of Physics Enrico Fermi, Vol. 147, pp. 627-42. Ingenta 1025439480MantleMelt
DS200712-0085
2005
Boehler, R.Boehler, R.Diamonds as optical windows to extreme conditions.In: Mineral Behaviour at Extreme Conditions, R. Miletich ed. ( total 488p) 24 Euros., TechnologyMineralogy
DS200712-0437
2007
Boehler, R.Hillgren, V.J., Schwager, B., Boehler, R.Potassium as a heat source in the core? Metal-silicate partitioning of K and other alkali metals.Plates, Plumes, and Paradigms, 1p. abstract p. A406.MantleGeochemistry
DS201809-1997
2018
Boehler, R.Boehler, R.Surprising" phase behavior of pure carbon: is diamond metastable at high pressures?Goldschmidt Conference, 1p. AbstractMantlemelting

Abstract: Flash laser heating in diamond anvil cells has been performed to melt diamond up to 37.5 GPa and 4500K using three different methods and three different starting materials: graphite, glassy carbon and diamond. In these experiments molten diamonds were confirmed by FIB/SEM images of the quenched samples. The melting slope of diamond is strongly negative, in contrast to all theoretical predictions. This is the first direct measurement of diamond melting temperatures at high pressure supporting early predictions based on analogies in the phase behavior of the group IV elements carbon, silicon and germanium. For diamond, these analogies had been dismissed for over 30 years based on theoretical grounds. The results imply that, at very high pressure, diamond, seemingly stable in all static and shock experiments, must be outside its thermodynamic stability field. This could be comparable to its behavior at ambient pressures, where diamond exhibits remarkable stability when heated to several thousand degrees even though the thermodynamically stable form of carbon is graphite.
DS1910-0337
1913
Boehm, J.Boehm, J., Weisfermel, W.Ueber Tertiare Versteinerungen von Den Bogenfelser Diamantfeldern.Beitr. Geol. Erf. Deut Schutzgeb., Vol. 5, PP. 59-111.Southwest Africa, NamibiaPalaeontology, Littoral Diamond Placers
DS1910-0364
1913
Boehm, J.Lotz, H., Boehm, J., Weissermel, W.Geologische und Palaeontologische Beitrage zur Kenntnis Der luederitz buchter Diamantablagerungen.Beitr. Geol. Erforsch. Deutsch. Schutzgeb., No. 5, 111P.Southwest Africa, NamibiaGeology, Palaeontology, Kimberley
DS1910-0581
1919
Boehm, J.Boehm, J.Mya Klinghardti Nov. Sp. Aus der Tertiaren Diamant fuehrenden Strand terrasse Bei Bogenfels in Suedwestafrika.Zeitschr. Deuts. Geol. Gesell., Vol. 71, P. 78.Southwest Africa, NamibiaStratigraphy, Paleontology, Littoral Diamond Placers
DS1920-0274
1926
Boehm, J.Boehm, J.Ueber Tertiare Versteinerungen von Den Bogenfelser Diamantfeldern.Die Diamantenwueste Suedwest Afrika, Kaiser, E. Ed., Vol. 2, PP. 55-106.Southwest Africa, NamibiaStratigraphy, Paleontology, Littoral Diamond Placers
DS201608-1390
2016
Boehnke, P.Bell, E.A., Boehnke, P., Harrison, T.M.Recovering the primary geochemistry of Jack Hills zircons through quantitative estimates of chemical alteration.Geochimica et Cosmochimica Acta, Vol. 191, pp. 187-202.AustraliaJack Hills REE

Abstract: Despite the robust nature of zircon in most crustal and surface environments, chemical alteration, especially associated with radiation damaged regions, can affect its geochemistry. This consideration is especially important when drawing inferences from the detrital record where the original rock context is missing. Typically, alteration is qualitatively diagnosed through inspection of zircon REE patterns and the style of zoning shown by cathodoluminescence imaging, since fluid-mediated alteration often causes a flat, high LREE pattern. Due to the much lower abundance of LREE in zircon relative both to other crustal materials and to the other REE, disturbance to the LREE pattern is the most likely first sign of disruption to zircon trace element contents. Using a database of 378 (148 new) trace element and 801 (201 new) oxygen isotope measurements on zircons from Jack Hills, Western Australia, we propose a quantitative framework for assessing chemical contamination and exchange with fluids in this population. The Light Rare Earth Element Index is scaled on the relative abundance of light to middle REE, or LREE-I = (Dy/Nd) + (Dy/Sm). LREE-I values vary systematically with other known contaminants (e.g., Fe, P) more faithfully than other suggested proxies for zircon alteration (Sm/La, various absolute concentrations of LREEs) and can be used to distinguish primary compositions when textural evidence for alteration is ambiguous. We find that zircon oxygen isotopes do not vary systematically with placement on or off cracks or with degree of LREE-related chemical alteration, suggesting an essentially primary signature. By omitting zircons affected by LREE-related alteration or contamination by mineral inclusions, we present the best estimate for the primary igneous geochemistry of the Jack Hills zircons. This approach increases the available dataset by allowing for discrimination of on-crack analyses (and analyses with ambiguous or no information on spot placement or zircon internal structures) that do not show evidence for chemical alteration. It distinguishes between altered and unaltered samples in ambiguous cases (e.g., relatively high Ti), identifying small groups with potentially differing provenance from the main Jack Hills population. Finally, filtering of the population using the LREE-I helps to more certainly define primary correlations among trace element variables, potentially relatable to magmatic compositional evolution.
DS201611-2099
2016
Boehnke, P.Bell, E.A., Boehnke, P., Harrison, T.M.Recovering the primary geochemistry of Jack Hills zircons through quantitative estimates of chemical alteration.Geochimica et Cosmochimica Acta, Vol. 191, pp. 187-202.AustraliaGeochemistry

Abstract: Despite the robust nature of zircon in most crustal and surface environments, chemical alteration, especially associated with radiation damaged regions, can affect its geochemistry. This consideration is especially important when drawing inferences from the detrital record where the original rock context is missing. Typically, alteration is qualitatively diagnosed through inspection of zircon REE patterns and the style of zoning shown by cathodoluminescence imaging, since fluid-mediated alteration often causes a flat, high LREE pattern. Due to the much lower abundance of LREE in zircon relative both to other crustal materials and to the other REE, disturbance to the LREE pattern is the most likely first sign of disruption to zircon trace element contents. Using a database of 378 (148 new) trace element and 801 (201 new) oxygen isotope measurements on zircons from Jack Hills, Western Australia, we propose a quantitative framework for assessing chemical contamination and exchange with fluids in this population. The Light Rare Earth Element Index is scaled on the relative abundance of light to middle REE, or LREE-I = (Dy/Nd) + (Dy/Sm). LREE-I values vary systematically with other known contaminants (e.g., Fe, P) more faithfully than other suggested proxies for zircon alteration (Sm/La, various absolute concentrations of LREEs) and can be used to distinguish primary compositions when textural evidence for alteration is ambiguous. We find that zircon oxygen isotopes do not vary systematically with placement on or off cracks or with degree of LREE-related chemical alteration, suggesting an essentially primary signature. By omitting zircons affected by LREE-related alteration or contamination by mineral inclusions, we present the best estimate for the primary igneous geochemistry of the Jack Hills zircons. This approach increases the available dataset by allowing for discrimination of on-crack analyses (and analyses with ambiguous or no information on spot placement or zircon internal structures) that do not show evidence for chemical alteration. It distinguishes between altered and unaltered samples in ambiguous cases (e.g., relatively high Ti), identifying small groups with potentially differing provenance from the main Jack Hills population. Finally, filtering of the population using the LREE-I helps to more certainly define primary correlations among trace element variables, potentially relatable to magmatic compositional evolution.
DS201902-0284
2019
Boehnke, P.Keller, C.B., Husson, J.M., Mitchell, R.N., Bottke, W.F., Gernon, T.M., Boehnke, P., Bell, E.A., Swanson-Hysell, N.L., Peters, S.E.Neoproterozoic glacial origin of the Great Unconformity.PNAS, pnas.org/cqi/doi/10.1073/ pnas.1804350116 10p.Mantlegeomorphology

Abstract: The Great Unconformity, a profound gap in Earth’s stratigraphic record often evident below the base of the Cambrian system, has remained among the most enigmatic field observations in Earth science for over a century. While long associated directly or indirectly with the occurrence of the earliest complex animal fossils, a conclusive explanation for the formation and global extent of the Great Unconformity has remained elusive. Here we show that the Great Unconformity is associated with a set of large global oxygen and hafnium isotope excursions in magmatic zircon that suggest a late Neoproterozoic crustal erosion and sediment subduction event of unprecedented scale. These excursions, the Great Unconformity, preservational irregularities in the terrestrial bolide impact record, and the first-order pattern of Phanerozoic sedimentation can together be explained by spatially heterogeneous Neoproterozoic glacial erosion totaling a global average of 3-5 vertical kilometers, along with the subsequent thermal and isostatic consequences of this erosion for global continental freeboard.
DS2001-0218
2001
Boener, D.E.Craven, J.A., Kurtz, R.D., Boener, D.E., et al.Conductivity of western Superior Province upper mantle in northwestern OntarioCan. Geological Survey Current Research, No. 200-E6, 15p.Ontario, northwestGeophysics
DS2003-0126
2003
Boer, M.Boer, M., Sherbourne, R.Getting the most out of our diamonds: Namibia, De Beers and the arrival of Lev LevievInstitute for Public Policy Research, Sept. 14p.NamibiaHistory, economy, De Beers, Samicor, Trans Hex, Diamond
DS200412-0174
2003
Boer, M.Boer, M., Sherbourne, R.Getting the most out of our diamonds: Namibia, De Beers and the arrival of Lev Leviev.Institute for Public Policy Research, Sept. 14p.Africa, NamibiaHistory, economy, De Beers, Samicor, Trans Hex, Diamond
DS1996-0146
1996
Boerner, D.Boerner, D., Kurtz, R., Craven, J., Jones, F.W.Electromagnetic results from the Alberta basement lithoprobe transectRoss, G.M. Lithoprobe Alberta, No. 51, pp. 61-70.AlbertaGeophysics - electromagnetic
DS1997-0107
1997
Boerner, D.Boerner, D., Craven, J., Kurtz, R., Jones, W.Electrical structure in the Precambrian crust and mantle of westernCanada.Geological Survey of Canada Forum 1997 abstracts, p. 8. AbstractAlberta, SaskatchewanMantle, Geophysics - magnetotellurics
DS2000-0835
2000
Boerner, D.Ross, G.M., Eaton, D.W., Boerner, D., Miles, W.Tectonic entrapment and its role in the evolution of continental lithosphere: an example from Precambrian...Tectonics, in pressAlberta, Western CanadaTectonics - lithopshere
DS1989-0721
1989
Boerner, D.E.Jones, A.G., Boerner, D.E., Kurtz, R.D.Electrical crustal structure at the edge of the North American cratonGeological Association of Canada (GAC) Annual Meeting Program Abstracts, Vol. 14, p. A104. (abstract.)OntarioTectonics, Kapuskasing Lithoprobe
DS1995-0164
1995
Boerner, D.E.Boerner, D.E., Kurtz, R.D., Craven, J.A., Rondenay, QianBuried Proterozoic foredeep under the Western Canada sedimentary basinGeology, Vol. 23, No. 4, April pp. 297-300Alberta, SaskatchewanGeophysics -electromagnetics, Precamrbian basement
DS1995-0165
1995
Boerner, D.E.Boerner, D.E., Kurtz, R.D., Craven, J.A., Rondenay, S.Buried Proterozoic foredeep under the Western Canada sedimentary basin?Geology, Vol. 23, No. 4, Apr. pp. 297-300.Western Canada, AlbertaBasin - sedimentary, Tectonics, Precambrian Basement, Geophysics, electromagnetics
DS1996-0147
1996
Boerner, D.E.Boerner, D.E., Kurtz, R.D., Craven, JJ.A.Electrical conductivity and Paleo-Proterozoic foredeepsJournal of Geophysical Research, Vol. 101, No. B 6, June 10, pp. 13, 775-91Canada, North AmericaProterozoic, Geophysics
DS1997-0976
1997
Boerner, D.E.Ross, G.M., Eaton, D.W., Boerner, D.E., Clowes, R.M.Geologists probe buried craton in western CanadaEos, Vol. 78, No. 44, Nov. 4, pp. 493, 4, 7.AlbertaCraton, Geophysics - seismics
DS1998-0136
1998
Boerner, D.E.Boerner, D.E., Craven, J.A., Kurtz, R.D., Ross, JonesThe Great Falls Tectonic Zone: suture or intracontinnental shear zone?Canadian Journal of Earth Sciences, Vol. 35, No. 2, Feb. pp. 175-183.Alberta, WyomingTectonics, Archean, Proterozoic, Geophysics - electromagnetic
DS1998-0137
1998
Boerner, D.E.Boerner, D.E., Kurtz, R.D., Craven, J.A., Ross, JonesGeophysical evidence of mantle involvement in Paleoproterzoic orogenesisAnnales Geophysicae, 23rd Meet abstracts 16. supp. p. 175.AlbertaGeophysics
DS1998-1257
1998
Boerner, D.E.Ross, G.M., Eaton, D.W., Boerner, D.E.Reflections on assembly of western LaurentiaGeological Society of America (GSA) Annual Meeting, abstract. only, p.A46.Northwest TerritoriesTectonic, Lithoprobe
DS2000-0094
2000
Boerner, D.E.Boerner, D.E., Kurtz, R.D., Craven, J.A., Ross, JonesA synthesis of electromagnetic studies in lithoprobe Alberta Basement Transect: constraints PaleoproterozoicCanadian Journal of Earth Sciences, Vol.37, no11, Nov.pp.1509-34.AlbertaTectonics - indentation, Geophysics - electromagnetics
DS200512-0284
2005
Boerner, D.E.Ferguson, I.J., Craven, J.A., Kurtz, R.D., Boerner, D.E., Bailey, Wu, Orellana, Spratt, Wennberg, NortonGeoelectric response of Archean lithosphere in the western Superior Province, central Canada.Physics of the Earth and Planetary Interiors, Vol. 150, 1-3, May 16, pp. 123-143.Canada, OntarioGeophysics - magnetotelluric, North Caribou terrane
DS201012-0075
2010
Boesenberg, J.S.Brusentsova, T.N., Peale, R.E., Maukonen, D., Harlow, G.E., Boesenberg, J.S., Ebel, D.Far infrared spectroscopy of carbonate minerals.American Mineralogist, Vol. 95, pp. 1515-1522.TechnologyIR - not specific to diamonds
DS1960-0124
1961
Boeson, R.Boeson, R., Irving, E., Robertson, W.A.The Paleomagnetism of Some Igneous Rock Bodies in New Southwales.Royal Society. NEW SOUTH WALES Transactions, Vol. 94, PP. 224-232.AustraliaKimberlite, Non Kimberlitic Breccia Pipes
DS200812-0567
2008
BoettcherKietavainen, R., Woodard, J., Eklund, O., Hetherington, C.J., BoettcherApatite as a petrogenetic indicator for lamprophyres and carbonatites.Goldschmidt Conference 2008, Abstract p.A469.Europe, FennoscandiaChemistry - trace elements
DS1986-0082
1986
Boettcher, A.Boettcher, A.The relationship between alkali basalts (basanites) and gabbroic Xenoliths in the Cima volcanic field, eastern Mojave desert,CaliforniaGeological Society of America (GSA) Abstract Volume, Vol. 18, No. 2, p. 87. (abstract.)CaliforniaBasanite, Eclogite
DS1975-0653
1977
Boettcher, A.L.Windom, K.E., Boettcher, A.L.Lamprophyre Kimberlite Association Exemplified in Eclogite from Roberts victor Mine, South Africa: Evidence for Metasomatism in the Mantle.Geological Society of America (GSA), Vol. 9, PP. 1230-1231. (abstract.).South AfricaKimberlite Genesis, Petrology
DS1980-0068
1980
Boettcher, A.L.Boettcher, A.L., O'neil, J.R.Stable isotope chemical and petrographic studies of high pressure amphiboles and micas: evidence for metasomatism in the mantle sourceregions....American Journal of Science, Vol. 280-A, pp. 594-621.South AfricaAlkali Basalts, Kimberlites, Metasomatism
DS1980-0069
1980
Boettcher, A.L.Boettcher, A.L., Robertson, J.K., Wyllie, P.J.Studies in Synthetic Carbonatite Systems: Solidus Relationships for Cao Mgo Co2 H2o to 40 Kbar and Cao Mgo Sio2 Cos H2oto 10 Kbar.Journal of Geophysical Research, Vol. 85, No. B 12, DECEMBER 10TH. PP. 6937-6943.GlobalMineralogy
DS1980-0349
1980
Boettcher, A.L.Windom, K.E., Boettcher, A.L.Mantle Metasomatism and the Kimberlite-lamprophyre Association: Evidence from an Eclogite Nodule from Roberts Victor Mine, South Africa.Journal of Geology, Vol. 88, No. 6, PP. 705-712.South AfricaKimberlite Genesis
DS1983-0138
1983
Boettcher, A.L.Boettcher, A.L.Metasomatism of the Mantle and the Origin of Alkali BasaltsMantle Metasomatism And The Origin of Uktrapotassic And Rela, 1P.GlobalBlank
DS201012-0360
2010
Boettcher, I.Kietavainen, R., Woodard, J., Eklund, O., Boettcher, I.Apatite composition in post-collisional lamprophyres and carbonatites in the Fennoscandinavian Shield: insight into their petrogenesis.International Dyke Conference Held Feb. 6, India, 1p. AbstractEurope, FinlandCarbonatite
DS201012-0857
2010
Boettcher, I.Woodard, J., Boettcher, I.Determining depth of lamprophyre magma generation and emplacement: mica thermobarometry revisited.International Mineralogical Association meeting August Budapest, abstract p. 580.Europe, FennoscandiaGeothermometry
DS200912-0643
2009
Boettner, R.Ross, P., White, J.D., Lorenz, V., Zimanowski, B., Boettner, R., McClintock, M.Why lower diatremes in kimberlitic and non-kimberlitic systems are non-stratified, homogenized, and contain steep internal contacts: episodic burst and debris jets.GAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyMantleBoundary
DS200812-0919
2008
Boev, B.Prelevic, D., Boev, B., Zouros, N., Akai, C.Lamproites and alkaline rocks of southern Balkans and Aegean region.9th. IKC Field Trip Guidebook, CD 45p.Europe, Macedonia, Greece, TurkeyGuidebook - lamproites
DS201503-0135
2015
Bofan-Casanova, N.Bouhifd, M.A., Boyet, M., Cartier, C., Hammouda, T., Bofan-Casanova, N., Devidal, J.L., Andrault, D.Superchondritic Sm/Nd ratio of the Earth: impact of Earth's core formation.Earth and Planetary Science Letters, Vol. 413, March 1, pp. 158-166.MantleGeochronology

Abstract: This study investigates the impact of Earth's core formation on the metal-silicate partitioning of Sm and Nd, two rare-earth elements assumed to be strictly lithophile although they are widely carried by the sulphide phases in reducing material (e.g. enstatite chondrites). The partition coefficients of Sm and Nd (DSmDSm and DNdDNd) between molten CI and EH chondrites model compositions and various Fe-rich alloys (in the Fe-Ni-C-Si-S system) have been determined in a multi-anvil between 3 and 26 GPa at various temperatures between 2073 and 2440 K, and at an oxygen fugacity ranging from 1 to 5 log units below the iron-wüstite (IW) buffer. The chemical compositions of the run products and trace concentrations in Sm and Nd elements were determined using electron microprobe and laser ablation inductively coupled plasma-mass spectrometry. Our results demonstrate the non-fractionation of Sm and Nd during the segregation of the metallic phases: the initial Sm/Nd ratio of about 1 in the starting materials yields precisely the same ratio in the recovered silicate phases after the equilibration with the metal phases at all conditions investigated in this study. In addition, DSmDSm and DNdDNd values range between 10?310?3 and 10?510?5 representing a low solubility in the metal. An increase of the partition coefficients is observed with decreasing the oxygen fugacity, or with an increase of S content of the metallic phase at constant oxygen fugacity. Thus, based on the actual Sm and Nd concentrations in the bulk Earth, the core should contain less than 0.4 ppb for Sm and less than 1 ppb for Nd. These estimates are three orders of magnitude lower than what would be required to explain the reported 142Nd excess in terrestrial samples relative to the mean chondritic value, using the core as a Sm-Nd complementary reservoir. In other words, the core formation processes cannot be responsible for the increase of the Sm/Nd ratio in the mantle early in Earth history.
DS201910-2262
2019
Boffa Ballaran, T.Gruninger, H., Liu, Z., Siegel, R., Boffa Ballaran, T., Katsura, T., Senker, J., Frost, F.J.Oxygen vacancy ordering in aluminous bridgmanite in the Earth's lower mantle.Geophysical Research Letters, Vol. 46, 15, pp. 8731-8740.Mantlebridgmanite

Abstract: The lower mantle encompasses the largest region of the Earth's interior and is mainly composed of the perovskite?structured mineral (Mg,Fe,Al)(Al,Si)O3 bridgmanite. Its properties, therefore, control both the diffusive transport of elements and solid state flow in the lower mantle, which will be strongly influenced by point defects. We have identified and quantified defects in bridgmanite that arise from the replacement of silicon by aluminum and result in the creation of a vacant oxygen site. These oxygen defects are also found to form clusters in the structure, which in other perovskite structured minerals have been shown to strongly affect physical properties. As defect formation and ordering is dependent on composition and pressure, strong variations in physical properties may be expected within the upper 300 km of the lower mantle.
DS200712-0777
2007
Boffa Ballaran, T.Nestola, F., Longo, M., McCammon, C., Boffa Ballaran, T.Crystal structure refinement of Na bearing clinopyroxenes from mantle derived eclogite xenoliths.American Mineralogist, Vol. 92, pp. 1242-1245.RussiaDeposit - Udachnaya, Zagadochnaya
DS201112-0767
2011
Boffa Ballaran, T.Pamato, M.G., Boffa Ballaran, T., Frost, D.J., Kurnosov, A., Trots, D.M.The elasticity of hydrous minerals in the lower mantle.Goldschmidt Conference 2011, abstract p.1591.MantleWater recycling
DS201212-0078
2012
Boffa Ballaran, T.Boffa Ballaran, T., Kurosov, A., Glazyrin, K., Frost, D.J., Merlini, M., Hanfland, M., Caracas, R.Effect of chemistry on the compressibility of silicate perovskite in the lower mantle.Earth and Planetary Science Letters, Vol. 333-334, pp. 181-190.MantlePerovskite
DS201312-0247
2013
Boffa Ballaran, T.Ernok, A., Boffa Ballaran, T., Caracas, R., Miyajima, N., Bykova, E., Prakapenka, V., Liermann, H-P., Dubrovinsky, L.Pressure induced phase transitions in coesite.Goldschmidt 2013, AbstractTechnologyCarbonatite
DS201412-0297
2014
Boffa Ballaran, T.Glazyrin, K., Boffa Ballaran, T., Frost, D.J., McCammon, C., Kantor, A., Merlini, M., Hanfland, M., Dubrovinsky, L.Magnesium silicate perovskite and effect of iron oxidation state on its bulk sound velocity at the conditions of the lower mantle.Earth and Planetary Science Letters, Vol. 393, pp. 182-186.MantlePerovskite
DS201603-0368
2015
Boffa Ballaran, T.Chang, Y-Y., Jacobsen, S.D., Bina, C.R., Thomas, S-M., Smyth, J.R., Frost, D.J., Boffa Ballaran, T., McCammon, C.A., Hauri, E.H., Inoue, T., Yurimoto, H., Meng, Y., Dera, P.Comparative compressibility of hydrous wadsleyite and ringwoodite: effect of H2O and implications for detecting water in the transition zone.Journal of Geophysical Research,, Vol. 120, 12, pp. 8259-8280.MantleRingwoodite

Abstract: Review of recent mineral physics literature shows consistent trends for the influence of Fe and H2O on the bulk modulus (K0) of wadsleyite and ringwoodite, the major phases of Earth's mantle transition zone (410-660?km). However, there is little consensus on the first pressure derivative, K0??=?(dK/dP)P=0, which ranges from about 4 to >5 across experimental studies and compositions. Here we demonstrate the importance of K0? in evaluating the bulk sound velocity of the transition zone in terms of water content and provide new constraints on the effect of H2O on K0? for wadsleyite and ringwoodite by conducting a comparative compressibility study. In the experiment, multiple crystals of hydrous Fo90 wadsleyite containing 2.0 and 0.25?wt?% H2O were loaded into the same diamond anvil cell, along with hydrous ringwoodite containing 1.4?wt?% H2O. By measuring their pressure-volume evolution simultaneously up to 32?GPa, we constrain the difference in K0? independent of the pressure scale, finding that H2O has no effect on K0?, whereas the effect of H2O on K0 is significant. The fitted K0? values of hydrous wadsleyite (0.25 and 2.0?wt?% H2O) and hydrous ringwoodite (1.4?wt?% H2O) examined in this study were found to be identical within uncertainty, with K0? ~3.7(2). New secondary-ion mass spectrometry measurements of the H2O content of these and previously investigated wadsleyite samples shows the bulk modulus of wadsleyite is reduced by 7.0(5)?GPa/wt?% H2O, independent of Fe content for upper mantle compositions. Because K0? is unaffected by H2O, the reduction of bulk sound velocity in very hydrous regions of transition zone is expected to be on the order of 1.6%, which is potentially detectible in high-resolution, regional seismology studies.
DS201610-1893
2016
Boffa Ballaran, T.Pamato, M.G., Kurnosov, A., Boffa Ballaran, T., Frost, D.J., Ziberna, L., Gianni, M., Speziale, S., Tkachev, S.N., Zhuravlev, K.K., Prakapenka, V.B.Single crystal elasticity of majoritic garnets: stagnant slabs and thermal anomalies at the base of the transition zone.Earth and Planetary Science Letters, Vol. 451, pp. 114-124.MantleSubduction

Abstract: The elastic properties of two single crystals of majoritic garnet (Mg3.24Al1.53Si3.23O12 and Mg3.01Fe0.17Al1.68Si3.15O12), have been measured using simultaneously single-crystal X-ray diffraction and Brillouin spectroscopy in an externally heated diamond anvil cell with Ne as pressure transmitting medium at conditions up to ?30 GPa and ?600 K. This combination of techniques makes it possible to use the bulk modulus and unit-cell volume at each condition to calculate the absolute pressure, independently of secondary pressure calibrants. Substitution of the majorite component into pyrope garnet lowers both the bulk (KsKs) and shear modulus (G ). The substitution of Fe was found to cause a small but resolvable increase in KsKs that was accompanied by a decrease in ?Ks/?P?Ks/?P, the first pressure derivative of the bulk modulus. Fe substitution had no influence on either the shear modulus or its pressure derivative. The obtained elasticity data were used to derive a thermo-elastic model to describe VsVs and VpVp of complex garnet solid solutions. Using further elasticity data from the literature and thermodynamic models for mantle phase relations, velocities for mafic, harzburgitic and lherzolitic bulk compositions at the base of Earth's transition zone were calculated. The results show that VsVs predicted by seismic reference models are faster than those calculated for all three types of lithologies along a typical mantle adiabat within the bottom 150 km of the transition zone. The anomalously fast seismic shear velocities might be explained if laterally extensive sections of subducted harzburgite-rich slabs pile up at the base of the transition zone and lower average mantle temperatures within this depth range.
DS201908-1788
2019
Boffa Ballaran, T.Liu, Z., Greaux, S., Cai, N., Siersch, N., Boffa Ballaran, T., Irifune, T., Frost, D.J.Influence of aluminum on the elasticity of majorite pyrope garnets.American Mineralogist, Vol. 104, pp. 929-935.Mantlegarnets

Abstract: The effect of aluminum (Al) on the elasticity of majorite-pyrope garnets was investigated by means of ultrasonic interferometry measurements on well-fabricated polycrystalline specimens. Both velocities and elastic moduli increase almost linearly with increasing Al content within analytical uncertainty. No significant variation of the velocities and elastic moduli is observed across the tetragonal-to-cubic phase transition at majorite with the pyrope content up to 26 mol% along the majorite-pyrope system. The elasticity variation of majorite-pyrope garnets is largely dominated by the Al content, while the phase transition as a result of cation ordering/disordering of Mg and Si via substitution of Al on octahedral sites cannot significantly affect elastic properties. Seismic velocity variations of a garnet-bearing mantle transition zone are therefore dominated by garnet composition (e.g., Al, Fe, Ca, and Na) rather than the tetragonal-to-cubic phase transition because of cation ordering/disordering.
DS201910-2243
2019
Boffa Ballaran, T.Amrstrong, K., Frost, D.J., McCammon, C.A., Rubie, D.C., Boffa Ballaran, T.Deep magma ocean formation set the oxidation state of Earth's mantle.Science, Vol. 365, 6456, pp. 903-906.Mantleredox

Abstract: The composition of Earth’s atmosphere depends on the redox state of the mantle, which became more oxidizing at some stage after Earth’s core started to form. Through high-pressure experiments, we found that Fe2+ in a deep magma ocean would disproportionate to Fe3+ plus metallic iron at high pressures. The separation of this metallic iron to the core raised the oxidation state of the upper mantle, changing the chemistry of degassing volatiles that formed the atmosphere to more oxidized species. Additionally, the resulting gradient in redox state of the magma ocean allowed dissolved CO2 from the atmosphere to precipitate as diamond at depth. This explains Earth’s carbon-rich interior and suggests that redox evolution during accretion was an important variable in determining the composition of the terrestrial atmosphere.
DS202105-0767
2021
Boffa Ballaran, T.Huang, R., Boffa Ballaran, T., McCammon, C.A., Miyajima, N., Frost, D.J.The composition and redox state of bridgmanite in the lower mantle as a function of oxygen fugacity.Geochimica et Cosmochimica Acta, Vol. 30, pp. 110-136.Mantleredox

Abstract: The chemistry of bridgmanite (Brg), especially the oxidation state of iron, is important for understanding the physical and chemical properties, as well as putting constraints on the redox state, of the Earth’s lower mantle. To investigate the controls on the chemistry of Brg, the Fe3+ content of Brg was investigated experimentally as a function of composition and oxygen fugacity (fo2) at 25 GPa. The Fe3+/?Fe ratio of Brg increases with Brg Al content and fo2 and decreases with increasing total Fe content and with temperature. The dependence of the Fe3+/?Fe ratio on fo2 becomes less steep with increasing Al content. Thermodynamic models were calibrated to describe Brg and ferropericlase (Fp) compositions as well as the inter-site partitioning of trivalent cations in Brg in the Al-Mg-Si-O, Fe-Mg-Si-O and Fe-Al-Mg-Si-O systems. These models are based on equilibria involving Brg components where the equilibrium thermodynamic properties are the main adjustable parameters that are fit to the experimental data. The models reproduce the experimental data over wide ranges of fo2 with a relatively small number of adjustable terms. Mineral compositions for plausible mantle bulk compositions can be calculated from the models as a function of fo2 and can be extrapolated to higher pressures using data on the partial molar volumes of the Brg components. The results show that the exchange of Mg and total Fe (i.e., ferric and ferrous) between Brg and Fp is strongly fo2 dependent, which allows the results of previous studies to be reinterpreted. For a pyrolite bulk composition with an upper mantle bulk oxygen content, the fo2 at the top of the lower mantle is ?0.86 log units below the iron-wüstite buffer (IW) with a Brg Fe3+/?Fe ratio of 0.50 and a bulk rock ratio of 0.28. This requires the formation of 0.7?wt.% Fe-Ni alloy to balance the raised Brg ferric iron content. With increasing pressure, the model predicts a gradual increase in the Fe3+/?Fe ratio in Brg in contrast to several previous studies, which levels off by 50 GPa. Oxygen vacancies in Brg decrease to practically zero by 40 GPa, potentially influencing elasticity, diffusivity and rheology in the top portion of the lower mantle. The models are also used to explore the fo2 recorded by inclusions in diamonds, which likely crystallized as Brg in the lower mantle, revealing oxygen fugacities which likely preclude the formation of some diamonds directly from carbonates, at least at the top of the lower mantle.
DS201312-0148
2013
Bogachev, V.I.Chanturia, V.A., Bogachev, V.I., Trofimova, E.A., Dvoichenkova, G.P.Mechanism and efficiency of water based removal of grease from diamonds during grease seperation.Journal of Mining Science, Vol. 48, 3, pp. 559-564.Russia, YakutiaDeposit - Mir
DS1995-1530
1995
Bogadikov, O.A.Puchtel, I.S., Bogadikov, O.A., et al.The role of crustal and mantle sources in the petrogenesis of continentalmagmatism: picrites OnegaPetrology, Vol. 3, No. 4, July-August, pp. 357-378Russia, Baltic shield, Karelia, KolaGeochemistry, Proterozoic
DS1996-0148
1996
Bogaert, P.Bogaert, P.Comparison kriging techniques in a space time contextMathematical Geology, Vol. 28, No. 1, Jan. pp. 73-86GlobalGeostatistics
DS2002-0289
2002
Bogaert, P.Christakos, G., Bogaert, P., Serre, M.L.Temporal GIS: advanced functions for field based applicationsSpringer, 220p.GlobalBook - GIS ( not specific to diamond), Bayesian maximum entropy
DS2003-0057
2003
Bogaerts, M.Auwera, J.V., Bogaerts, M., Liegeois, J.P., De Maiffe, D., Wilmart, E., Bolle, O.Derivation of the 1.0 0.9 Ga ferro potassic A type granitoids of southern Norway byPrecambrian Research, Vol. 124, 2-4, pp. 107-148..NorwayBlank
DS200412-0077
2003
Bogaerts, M.Auwera, J.V., Bogaerts, M., Liegeois, J.P., De Maiffe, D., Wilmart, E., Bolle, O., Duchesne, J.C.Derivation of the 1.0 0.9 Ga ferro potassic A type granitoids of southern Norway by extreme differentiation from basic magmas.Precambrian Research, Vol. 124, 2-4, pp. 107-148..Europe, NorwayAlkalic
DS1990-0163
1990
Bogardi, I.Bardossy, A., Bogardi, I., Kelly, W.E.Kriging with imprecise (Fuzzy) variograms. I. theory. II. ApplicationsMath. Geol, Vol. 22, No. 1, pp. 63-79. pt. 2. 81-94GlobalGeostatistics, Kriging, variograM.
DS1998-1124
1998
BogatikovParsadanyan, K.S., Pervov, V.A., Bogatikov, KononvaGeochemical features of high magnesium alkaline rocks and their correlation with geological evolution - structureMineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1137-8.Russia, Baltic ShieldAlkaline rocks, Geochemistry
DS2002-0876
2002
BogatikovKononova, V.A., Levsky, L.K., Pervov, V.A., Ovchinnikova, G.V., BogatikovPb Sr Nd isotopic systematics of mantle sources of potassic ultramafic and mafic rocksPetrology, Vol. 10, 5, pp. 433-47.RussiaAlkaline rocks, Geochronology
DS2002-0877
2002
BogatikovKononova, V.A., Levsky, L.K., Pervov, V.A., Ovchinnikova, G.V., BogatikovPb Sr Nd isotopic systematics of mantle sources of potassic ultramafic and mafic rocks in the north and east European platform.Petrology, Vol. 10, 5, pp. 433-47.Russia, UralsGeochronology, Alkaline rocks
DS2002-0878
2002
Bogatikov, A.Kononova, V.A., Levsky, L.K., Pervov, V.A., Ovchinnikova, G.V., Bogatikov, A.Pb Sr Nd isotopic systematics of mantle sources of potassic ultramafic and mafic rocksPetrology, Vol. 10, 5, pp. 433-47.Russia, Europe, Kola PeninsulaGeochronology
DS1985-0069
1985
Bogatikov, O.A.Bogatikov, O.A., Makhotkin, I.L., Konova, V.A.Lamproites and their position in the classification of magnesium richpotassic rocks. (Russian)Izv. Akad. Nauk SSSR Ser. Geol. (Russian), No. 12, pp. 3-10RussiaLamproite, Potassic
DS1986-0083
1986
Bogatikov, O.A.Bogatikov, O.A., Eremeev, N.V., Makhotin, I.L., et al.Lamproites of Aldan and Central Asia.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 290, No. 4, pp. 936-940RussiaLamproite, Petrology
DS1986-0084
1986
Bogatikov, O.A.Bogatikov, O.A., Eremeev, N.V., Makhotkin, I.L., Konova, V.A.Lamproites of Aldan and Middle Asia.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol 290, No. 4, pp. 936-940RussiaLamproites
DS1987-0063
1987
Bogatikov, O.A.Bogatikov, O.A., Kononova, V.A., Makhotkin, I.L., Eremeev, N.V.Rare earth and elements as indicators of the origin of lamproites of central Aldan (USSR).(Russian)Vulkanol. Seismol., (Russian), No. 1, pp. 15-29RussiaLamproites, Rare earths
DS1988-0065
1988
Bogatikov, O.A.Bogatikov, O.A., Kononova, V.A., Makhotkin, I.L.Lamproites. (Russian)Ultrabasic rocks, Magmaticheskiye Gornyye Porody, Izd. Nauka, Moscow, Vol. 5, pp. 217-229RussiaLamproites, Geochemistry
DS1988-0066
1988
Bogatikov, O.A.Bogatikov, O.A., Yeremeyev, N.V., Makhotkin, I.L., Kononova, V.A.Lamproites of the Aldan and central AsiaDoklady Academy of Science USSR, Earth Science Section, Vol. 290, No. 1-6, March pp. 154-157RussiaLamproite, Analyses
DS1989-0132
1989
Bogatikov, O.A.Bogatikov, O.A.Crystalline crust in space and in time. ..magmatism.(Russian)Moscow, Nayka, Monograph, (Russian), approx. 270p. Table of contents translated in EnglishRussiaUpper mantle, Magma
DS1989-0133
1989
Bogatikov, O.A.Bogatikov, O.A., Makhotkin, I.L., Kononova, V.A.Lamproites: composition and petrogenetic questions. (Russian)Moscow, Nayka, Monograph, (Russian), pp. 92-100RussiaLamproites, Petrology
DS1989-0134
1989
Bogatikov, O.A.Bogatikov, O.A., Makhotkin, I.L., Kononova, V.A.Lamproites, composition and aspects of petrogenesis.(Russian)Kristal. Kora V Prostranstve i vrement: magmatizm Dokl. Sov. Geol, pp. 92-100. Chem abstracts E1310:082300M CA 153003RussiaLamproites, Genesis
DS1989-0135
1989
Bogatikov, O.A.Bogatikov, O.A., Makhotkin, I.P., Kononova, V.A.Lamproites, composition and petrogenetic questions.(Russian)in: Crystalline crust in space and time; magmatism, (Russian), Izd. Nauka, Moscow, pp. 91-100RussiaLamproites, Petrology
DS1990-0874
1990
Bogatikov, O.A.Kononova, V.A., Makhotkin, I.L., Malov, Y.V., Bogatikov, O.A.Lamproites and petrochemical series of potassium rocks.(Russian)Izves. Akad. Nauk SSSR, (Russian), Ser, Geol. No. 11, November pp. 55-65RussiaLamproites, Petrochemistry
DS1991-0137
1991
Bogatikov, O.A.Bogatikov, O.A., Garanin, V.K., Kononova, K.A., Kudrjavtseva, G.P.Ore minerals from the lamproite ground massProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 484-485Russia, Australia, SpainOxide mineral chemistry, Diamond evaluation
DS1991-0138
1991
Bogatikov, O.A.Bogatikov, O.A., Konnonova, V.A.Lamproites. (Russian) languageIzd. Nauka, Moscow Publication, (Russian), 294pRussiaBook -Lamproites, Petrology
DS1991-0139
1991
Bogatikov, O.A.Bogatikov, O.A., Lazko, Ye.Ye., Sharkov, Ye.V.Potential sources of subcrustal magmasDoklady Academy of Sciences USSR Earth Sci. Section, Vol. 313, No. 1, pp. 175-178RussiaMantle, Kimberlite
DS1993-0891
1993
Bogatikov, O.A.Lazko, Ye.Ye., Sharkov, Ye.V., Bogatikov, O.A.Mantle substrates: their geochemical classification and role in subcrustal magma formation.Geochemistry International, Vol. 30, No. 9, pp. 1-24.MantleGeochemistry, Xenoliths in basalts and kimberlites
DS1994-0175
1994
Bogatikov, O.A.Bogatikov, O.A., Kononova, V.A., et al.Petrogenesis of Mesosoic potassic magmatism of the Central Aldan: a isotopic and geodynamic modelInternational Geology Review, Vol. 36, No. 7, July pp. 629-644Russia, AldanMagmatism, Geochronology
DS1994-0176
1994
Bogatikov, O.A.Bogatikov, O.A., Kononova, V.A., Pervov, V.A., ZhguralevPetrogenesis of Mesozoic potassic magmatism of the central Aldan: a isotopic and geodynamic model.International Geology Review, Vol. 36, No. 7, July pp. 629-644.Russia, AldanAlkalic rocks, Geochronology
DS1995-0992
1995
Bogatikov, O.A.Kononova, V.A., Bogatikov, O.A., Pervov, V.A., YeremeyevCentral Asian potassic magmatic rocks: geochemistry and formationconditions.Geochemistry International, Vol. 32, No. 2, pp. 23-42.Russia, AsiaAlkaline rocks, Geochemistry
DS1996-1066
1996
Bogatikov, O.A.Parasdanyan, K.S., Konnonova, Y.A., Bogatikov, O.A.Sources of heterogenous magmatism of the Arkanglesk diamondiferousprovince.Petrology, Vol. 4, No. 5, Sept-Oct., pp. 460-479.Russia, ArkangelskMagmatism
DS1996-1289
1996
Bogatikov, O.A.Sharkov, E.V., Bogatikov, O.A., Kovalenko, V.I., Bogina, M.Petrology and geochemistry of continental and oceanic magmatic and metamorphic rocks. - Early Prec. eclogitesRussian Geology and Geophysics, Vol. 37, No. 1, pp. 85-102.Russia, Kola Peninsula, SayanEclogites, Baltic Shield
DS1999-0079
1999
Bogatikov, O.A.Bogatikov, O.A., Kononova, V.A., Pervov, ParsadanyanUltramafic Diamondiferous rocks, Russian platform and geodynamicsStanley, SGA Fifth Biennial Symposium, pp. 1301-4.RussiaMelilitite, lamproite, lamprophyre, picrite
DS2000-0885
2000
Bogatikov, O.A.Sharkov, E.V., Bogatikov, O.A.Early Proterozoic magmatism and geodynamics - evidence of a fundamental change in Earth's evolution. Chapter 5In: Bogatikov Magmatism and Geodynamics, Overseas Publishing pp. 219-252.Russia, Norway, Kola, Baltic StatesMagmatism
DS2001-0117
2001
Bogatikov, O.A.Bogatikov, O.A., Kononova, V.A., Pervov, ZhuravlevSources, geodynamic setting of formation and diamond bearing potential of kimberlites from northern marginPetrology, Vol. 9, No. 3, pp. 191-203.RussiaPlate - Sr neodymium isotopic and ICP MS, Geochronology, geochemistry
DS2003-1256
2003
Bogatikov, O.A.Sharkov, E.V., Trubkin, N.V., Krasivskaya, I.S., Bogatikov, O.A., Mokhov, A.V.The oldest volcanic glass in the Early Paleoproterozoic boninite type lavas, KarelianDoklady Earth Sciences, Vol. 390, 4, May-June pp. 580-4.Russia, KareliaBoninite
DS200412-1317
2004
Bogatikov, O.A.Mineeva, R.M., Speranskii, A.V., Titkov, S.V., Zhilicheva, O.M., Bershov, L.V., Bogatikov, O.A., KudryavtsevaSpectroscopic and morphological characteristics of diamonds from the Grib kimberlite pipe.Doklady Earth Sciences, Vol. 394, 1, Jan-Feb. pp. 96-99.Russia, Kola Peninsula, ArchangelDiamond morphology, deposit - Grib
DS200412-1794
2003
Bogatikov, O.A.Sharkov, E.V., Trubkin, N.V., Krasivskaya, I.S., Bogatikov, O.A., Mokhov, A.V.The oldest volcanic glass in the Early Paleoproterozoic boninite type lavas, Karelian craton: results of instrumental investigatDoklady Earth Sciences, Vol. 390, 4, May-June pp. 580-4.Russia, KareliaBoninites
DS200412-1795
2004
Bogatikov, O.A.Sharkov, E.V., Trubkin, N.V., Krassivskaya, I.S., Bogatikov, O.A., Mokhov, A.V., Chistyakov, EvseevaStructural and compositional characteristics of the oldest volcanic glass in the early paleoproterozoic boninite like lavas of sPetrology, Vol.12, 3, pp. 227-244.Russia, KareliaBoninites
DS200412-2192
2004
Bogatikov, O.A.Yutkina, E.V., Kononova, V.A., Bogatikov, O.A., Knyazkov, A.P., Kozar, N.A., Ovchinnikova, G.V., Levsky, L.K.Kimberlites of eastern Priazove ( Ukraine) and geochemical characteristics of their sources.Petrology, Vol. 12, 2, pp. 134-148.Europe, UkraineDevonian age, Arkangelsk, Terskii Bereg, Novolaspinakay
DS200512-0100
2004
Bogatikov, O.A.Bogatikov, O.A., Kononova, V.A., Golubeva, Zinchuk, Ilupin, Rotman, Levsky, Ovchinnikova, KondrashovVariations in chemical and isotopic compositions of the Yakutian kimberlites and their causes.Geochemistry International, Vol. 42, 9, pp. 799-821.Russia, Siberia, YakutiaGeochemistry
DS200512-0560
2005
Bogatikov, O.A.Kononova, V.A., Golubeva, Y.Y., Bogatikov, O.A., Nosova, Levsky, OvchinnikovaGeochemical diversity of Yakutian kimberlites: origin and diamond potential (ICP-MS dat a and Sr, Nd and Pb isotropy).Petrology, Vol. 13, 3, pp. 205-228.RussiaMineral chemistry
DS200712-0086
2007
Bogatikov, O.A.Bogatikov, O.A., Kononova, V.A., Nosova, A.A., Kondrashov, I.A.Kimberlites and lamproites of east European platform: petrology and geochemistry.Petrology, Vol. 15, 4, pp.EuropeLamproite
DS200712-0087
2007
Bogatikov, O.A.Bogatikov, O.A., Kononova, V.A., Nosova, A.A., Kondrashov, I.A.Kimberlites and lamproites of east European platform: petrology and geochemistry.Petrology, Vol. 15, 4, pp.EuropeLamproite
DS200812-0122
2008
Bogatikov, O.A.Bogatikov, O.A., Kononova, V.A., Dubinina, E.O., Nosova, A.A., Kondrashov, I.A.Nature of carbonates from kimberlites of the Zimnii Bereg field, Arkangelsk: evidence from Rb Sr C and O isotope data.Doklady Earth Sciences, Vol. 421,1, pp. 807-811.Russia, Kola Peninsula, ArchangelDeposit - Zimnii Bereg
DS200812-0585
2007
Bogatikov, O.A.Kononova, V.A., Golubeva, Y.Y., Bogatikov, O.A., Kargin, A.V.Diamond resource potential of kimberlites from the Zimny Bereg field, Arkangelsk oblast.Geology of Ore Deposits, Vol. 49, 6, pp. 421-441.Russia, Kola PeninsulaDeposit - Zimny Bereg
DS200912-0059
2009
Bogatikov, O.A.Bogatikov, O.A., Kononova, V.A., Nusova, A.A., Kargin, A.V.Polygenetic sources of kimberlites, magma composition and diamond potential exemplified by the East European and Siberian cratons.Petrology, Vol. 17, 6, pp. 605-625.Russia, YakutiaChemistry
DS200912-0060
2009
Bogatikov, O.A.Bogatikov, O.A., Sharkov, E.V., Bogina, Kononova, Nosova, Samsonov, ChistyakovWithin plate (intracontinental) and postorogenic magmatism of the East European Craton as reflection of the evolution of continental lithosphere.Petrology, Vol. 17, 3, May pp. 207-226.RussiaMagmatism
DS200912-0399
2009
Bogatikov, O.A.Kononova, V.A., Kargin, A.V., Nosova, A.A., Kondrashov, I.A., Bogatikov, O.A.Geochemical comparison of kimberlites from the Siberian and East European platforms: problems of genesis and spatial zoning.Doklady Earth Sciences, Vol. 428, 1, pp. 1156-1161.Russia, EuropeKimberlite genesis
DS200912-0411
2009
Bogatikov, O.A.Kovalenko, V.I., Yarmolyk, V.V., Bogatikov, O.A.Regularities of spatial distribution of mantle hot spots of the modern Earth.Doklady Earth Sciences, Vol. 427, 2, pp. 924-928.MantlePlume
DS200912-0412
2009
Bogatikov, O.A.Kovalenko, V.I., Yarmolyuk, V.V., Bogatikov, O.A.The recent supercontinent in the northern hemisphere of the Earth ( North Pangea): magmatic and geodynamic evolution.Doklady Earth Sciences, Vol. 427, 2, pp. 897-901.MantleMagmatism
DS201012-0063
2010
Bogatikov, O.A.Bogatikov, O.A., Kononova, V.A., Nosova, A.A., Kargin, A.V.Polygenetic sources of kimberlites, magma composition, and diamond potential exemplified by the East European and Sibnerian cratons.Petrology, Vol. 17, 6, pp. 606-625.RussiaKimberlite genesis
DS201012-0410
2009
Bogatikov, O.A.Kovalenko, V.I., Yarmolyuk, V.V., Bogatikov, O.A.The recent supercontinent in the northern hemisphere of the Earth ( North Pangea): magmatic and geodynamic evolution.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., p. 151-157.MantleMagmatism
DS201012-0411
2009
Bogatikov, O.A.Kovalenko, V.I., Yarmolyuk, V.V., Bogatikov, O.A.Regularities of spatial distribution of mantle hot spots of the modern Earth.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., pp. 5-12.MantlePlume
DS201112-0535
2011
Bogatikov, O.A.Kononova, V.A., Bogatikov, O.A., Kondrashov, I.A.Kimberlites and lamproites: criteria for similarity and differences.Petrology, Vol. 19, 1, pp. 34-54.MantleGeodynamics - genesis
DS201112-0550
2010
Bogatikov, O.A.Kovalenko, V.I., Yarmolyuk, V.V., Bogatikov, O.A.Modern volcanism in the Earth's northern hemisphere and its relation with the evolution of the North Pangaea modern supercontinent and with the spatial ... hotspotsPetrology, Vol. 18, 7, pp. 657-676.MantleMantle plume, deep subduction
DS201504-0216
2015
Bogatikov, O.A.Sharkov, E.V., Bogatikov, O.A.Roots of magmatic systems in the large continental igneous Provinces.Doklady Earth Sciences, Vol. 460, 2, pp. 154-158.Europe, SyriaMantle xenoliths
DS201601-0025
2015
Bogatikov, O.A.Kargin, A.V., Babarina, I.I., Bogatikov, O.A., Yutkina, E.V., Kondrashov, I.A.Paleproterozoic Kimozero kimberlite ( Karelian Craton): geological setting and geochemical typing.Doklady Earth Sciences, Vol. 465, 1, pp. 1135-1138.RussiaDeposit - Kimozero

Abstract: Geological and structural mapping of Paleoproterozoic Kimozero kimberlite with account for lithological facies and geochemical specialization provides evidence for the multiphase structure of the kimberlite pipe, which underwent fragmentation as a result of shear–faulting deformations. Two geochemical types of kimberlite (magnesium and carbonate) are distinguished.
DS201811-2554
2018
Bogatikov, O.A.Bogatikov, O.A., Dokuchaev, A.Ya., Kargin, E.V., Yutkina, E.V., Kondrashov, I.A.Paleoproterozic kimberlites of the Lake Kimozero area, Karelian craton: ore mineralization in kimberlites and fault zones.Doklady Earth Sciences, Vol. 482, 1, pp. 1130-1133.Russiadeposit - Lake Kimozero

Abstract: Syngenetic and epigenetic ore mineralization was studied in Paleoproterozoic metakimberlites in the area of Kimozero Lake. In the Kimozero structure, redeposited ore mineralization is constrained to fracture and shear zones and consists of Fe-vaesite, Fe-Co-polydymite, millerite, Ni-pyrrhotite, pentlandite, chalcopyrite, Zn-bearing copper, galena, and Ni-pyrite. The composition of this mineralization is analogous to that of syngenetic mineralization in pyroclastic and coherent kimberlite, and its likely source was the kimberlite itself.
DS201909-2084
2019
Bogatikov, O.A.Sharkov, E.V., Chisyakov, A.V., Bogina, M.M., Bogatikov, O.A., Sjchiptsov, V.V., Belyatsky, B.V., Frolov, P.V.Ultramafic - alkaline - carbonatite complexes as a result of two stage melting of a mantle plume: from the Mid- Paleoproterozoic Tiksheozero intrusion, northern Karelia, Russia.Doklady Earth Sciences, Vol. 486, 2, pp. 638-643.Russia, Kareliacarbonatite

Abstract: The Tiksheozero ultramafic-alkaline-carbonatite intrusive complex, like numerous carbonatite-bearing complexes of similar composition, is a part of a large igneous province related to the ascent of a thermochemical mantle plume. The geochemical and isotopic data indicate that the formation of the ultramafic and alkaline rocks was related to crystallization differentiation of a primary alkali picritic melt, whereas carbonatite magmas were derived from an independent mantle source. We suggest that the origin of parental magmas of the Tiksheozero Complex, as well as other ultramafic-alkaline-carbonatite complexes, was provided by two-stage melting of the mantle-plume head: (1) adiabatic melting of its inner part generated moderately alkaline picrites, the subsequent fractional crystallization of which led to the appearance of alkaline magmas, and (2) incongruent melting of the upper cooled margin of the plume head under the influence of CO2-rich fluids, which arrived from underlying adiabatic melting zone, gave rise to carbonatite magmas.
DS200812-0123
2008
Bogatikov, O.A.A.A.Bogatikov, O.A.A.A., Larchenko, V.A.A.A., Kononova, V.A.A.A., Nosova, A.A.A.A., Minchenko, G.A.V.A.New kimberlite bodies in the Zimnii Bereg field, Archangelsk district: petrography and prognostic estimates.Doklady Earth Sciences, Vol. 418, 1, pp. 68-72.Russia, Archangel, Kola PeninsulaDeposit - Zimnii Bereg
DS2000-0515
2000
Bogatikov, Parsadanyan et al.Kononova, V.A., Pervov, Bogatikov, Parsadanyan et al.Potassic mafic rocks with megacrysts from northwestern Ladoga Lake area: diversity of mantle sources potassicGeochemistry International, Vol. 38, No.S1, pp. S39-58.Russia, Karelia, FennoscandiaTectonics, geochronology, alkaline, Shonkinite, minette
DS1987-0064
1987
Bogatryeva, G.P.Bogatryeva, G.P., Gvyazdocskaya, V.L., Bazalii, G.A.Effect of chemical treatment on the change in adsorption structural characteristics of diamond and graphite.(Russian)Fiz. Khim, Svoistva Sverrktverd., (Russian), pp. 4-13RussiaBlank
DS1975-0244
1976
Bogatykh, I. YA.Bogatykh, I. YA.New Dat a on the Dynamic Effect of Traprock Intrusions on Kimberlite Bodies.Doklady Academy of Science USSR, Earth Science Section., Vol. 226, No. 1-6, PP. 31-32.RussiaKimberlite
DS1988-0349
1988
Bogatykh, M.M.Kharkiv, A.D., Bogatykh, M.M., Vishnevskii, A.A.Mineral composition of kelphyitic rims developed on garnets fromkimberlites.(Russian)Zap. Vses. Mineral. O-Va, (Russian), Vol. 117, No. 6, pp. 705-713RussiaGarnet analyses, Kelphyitic rims
DS1990-0826
1990
Bogatykh, M.M.Kharkiv, A.D., Zinchuk, N.N., Bogatykh, M.M., Romanov, N.N.A kimberlite pipe model for the Yakutskaya diamond province.(Russian)Sov. Geol., (Russian), No. 1, pp. 23-29RussiaModel -genesis, Yakutskaya province
DS201904-0717
2019
Bogdana-Radu, I.Bogdana-Radu, I., Harris, C., Moine, B.N., Costin, G., Cottin, J-Y.Subduction relics in the subcontinental lithospheric mantle evidence from variation in the delta 180 value of eclogite xenolths from the Kaapvaal craton.Contributions to Mineralogy and Petrology, Vol 174, https://doi.org/ 10.1007/s00410-019-1552-zAfrica, South Africadeposit - Roberts Victor, Jagersfontein

Abstract: Mantle eclogites are commonly accepted as evidence for ancient altered subducted oceanic crust preserved in the subcontinental lithospheric mantle (SCLM), yet the mechanism and extent of crustal recycling in the Archaean remains poorly constrained. In this study, we focus on the petrological and geochemical characteristics of 58 eclogite xenoliths from the Roberts Victor and Jagersfontein kimberlites, South Africa. Non-metasomatized samples preserved in the cratonic root have variable textures and comprise bimineralic (garnet (gt)-omphacite (cpx)), as well as kyanite (ky)- and corundum (cor)-bearing eclogites. The bimineralic samples were derived from a high-Mg variety, corresponding to depths of ~ 100-180 km, and a low-Mg variety corresponding to depths of ~ 180-250 km. The high-Al (ky-, cor-bearing) eclogites originated from the lowermost part of the cratonic root, and have the lowest REE abundances, and the most pronounced positive Eu and Sr anomalies. On the basis of the strong positive correlation between gt and cpx ?18O values (r2 = 0.98), we argue that ?18O values are unaffected by mantle processes or exhumation. The cpx and gt are in oxygen isotope equilibrium over a wide range in ?18O values (e.g., 1.1-7.6‰ in garnet) with a bi-modal distribution (peaks at ~ 3.6 and ~ 6.4‰) with respect to mantle garnet values (5.1 ± 0.3‰). Reconstructed whole-rock major and trace element compositions (e.g., MgO variation with respect to Mg#, Al2O3, LREE/HREE) of bimineralic eclogites are consistent with their protolith being oceanic crust that crystallized from a picritic liquid, marked by variable degrees of partial melt extraction. Kyanite and corundum-bearing eclogites, however, have compositions consistent with a gabbroic and pyroxene-dominated protolith, respectively. The wide range in reconstructed whole-rock ?18O values is consistent with a broadly picritic to pyroxene-rich cumulative sequence of depleted oceanic crust, which underwent hydrothermal alteration at variable temperatures. The range in ?18O values extends significantly lower than that of present-day oceanic crust and Cretaceous ophiolites, and this might be due to a combination of lower ?18O values of seawater in the Archaean or a higher temperature of seawater-oceanic crust interaction.
DS1991-0140
1991
Bogdanov, E.I.Bogdanov, E.I., Politiuk, V.I.Alluvial mining in the USSRAlluvial Mining, Institute of Mining and Metallurgy (IMM) Special Volume, pp. 1-18RussiaAlluvial mining, Placers - not specific to diamonds
DS1986-0210
1986
Bogdanov, G.V.Egorov, K.N., Bogdanov, G.V., Medvedeva, T.I.Zonal garnets from kinberlite pipe.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR (Russian), Vol. 290, No. 6, pp. 1463-1467GlobalBlank
DS1988-0192
1988
Bogdanov, G.V.Egorov, K.N., Bogdanov, G.V., Medvedeva, T.I.Zonal garnets with mineral inclusions from kimberlitic pipes of Malobotuobinskii region. (Russian)Izvest. Akad. Nauk Ser. Geol., (Russian), No. 1, January pp. 112-119RussiaBlank
DS1988-0196
1988
Bogdanov, G.V.Egorov, K.N., Ushchapovskaya, Z.F., Kashaev, A.A., Bogdanov, G.V.Zemkorite- new carbonate from kimberlites of Yakutia.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 301, No. 1, pp. 188-193RussiaUdachanaya
DS1990-1328
1990
Bogdanov, G.V.Sekerin, A.P., Menshagin, I.V., Bogdanov, G.V., Medvedeva, T.I.On the occurrence of basic and ultrabasic inclusions in Precambrian kimberlites of the Peri-Sayan.(Russian)Dokl. Akad., Nauk SSSR, (Russian), Vol. 312, No. 5, pp. 1231-1234RussiaKimberlite, Basic inclusions
DS1990-1612
1990
Bogdanov, G.V.Yegorov, K.N., Bogdanov, G.V., Paradina, L.F.Main regularities of the chemistry of serpentinization of kimberlites.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 315, No. 5, pp. 1213-1217RussiaGeochemistry, Serpentinization -kimberlites
DS1991-0432
1991
Bogdanov, G.V.Egorov, K.N., Vladimirov, B.M., Bogdanov, G.V.Geology, petrology and mineral composition of the Udachnaya kimberlite ore complex (Yakutia)Proceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 498-500RussiaPetrology, Deposit -Udachnaya
DS1991-1909
1991
Bogdanov, G.V.Yegorov, K.N., Bogdanov, G.V., Zavyalov, L.L.New dat a on the kimberlite composition of the Zagadochnaya pipe(Yakut).(Russian)Izvest. Akad. Nauk SSS, Geol., (Russian), No. 11, November pp. 98-108Russia, YakutiaKimberlite, Zagadochnaya mineralogy
DS1992-1362
1992
Bogdanov, G.V.Sekerin, A.P., Menshagin, Yu.V., Bogdanov, G.V., Medvedeva, T.I.Find of mafic and ultramafic inclusions in Precambrian kimberlite from the Sayan regionDoklady Academy of Science USSR, Earth Science Section, Vol. 312, No. 1-3, June pp. 203-205RussiaUltramafic inclusions, Kimberlite
DS1992-1720
1992
Bogdanov, G.V.Yegorov, K.N., Bogdanov, G.V., Pardina, L.F.The chemistry of the serpentinization of kimberliteDoklady Academy of Sciences USSR, Earth Science Section, Vol. 315, pp. 194-198.RussiaKimberlite, Alteration -serpentine
DS1995-0484
1995
Bogdanov, G.V.Egorov, K.N., Semenova, V.G., Bogdanov, G.V.Common patterns of the process of early serpentinization of dunites andkimberlites.. UralsRussian Geology and Geophysics, Vol. 36, No. 9, pp. 79-84.Russia, Yakutia, UralsKosva, ultrabasites, lizardite, brucite, Mineralogy -serpentization, kimberlites
DS1993-0831
1993
Bogdanov, N.A.Knipper, A.L., Dobretsov, N.L., Bogdanov, N.A.Metaophiolites and orogenic lherzolites of the Betic CordillerasInternational Geology Review, Vol. 35, No. 5, pp. 467-484GlobalRhonda, Ojen massifs, Lherzolite
DS1993-0832
1993
Bogdanov, N.A.Knipper, A.L., Dobretsov, N.L., Bogdanov, N.A.Metaophiolites and orogenic lherzolites of the Betic CordillerasInternational Geology Review, Vol. 35, No. 5, pp. 467-484.GlobalRhonda, Ojen massifs, Lherzolite
DS1993-0833
1993
Bogdanov, N.A.Knipper, A.L., Dobretsov, N.L., Bogdanov, N.A.Metaophiolites and orogenic lherzolites of the Betic CordilleraInternational Geology Review, Vol. 35, No. 5, May pp. 467-484RussiaBetic lherzolites
DS1991-0430
1991
Bogdanov, V.Egorov, K.N., Bogdanov, V.Mineralogical isotopic dynamics, physico-chemical conditions and stages of serpentinization process of kimberlites from YakutiaProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 492-494RussiaPetrology, Serpentinization, kimberlites
DS1991-0431
1991
Bogdanov, V.Egorov, K.N., Bogdanov, V., Solovjeva, L.V., Barankevich, V.G.Evidence of magmatism, metasomatism and deformation processes obtained From the study of the unique compositionally complex nodule from the Udachanya pipeProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 495-497RussiaNodule, Deposit -Udachnaya
DS2001-0688
2001
BogdanovaLifrovich, R.P., Pakhomovsky, Bogdanova, BalaganskayaCollinsite in hydrothermal assemblages related to carbonatites in the Kovdor Complex, northwestern RussiaCanadian Mineralogist, Vol. 39, No. 4, Aug. pp.1081-94.RussiaCarbonatite, mineralogy, Deposit - Kovdor
DS1993-0562
1993
Bogdanova, S.Gorbatschev, R., Bogdanova, S.Frontiers in the Baltic ShieldPrecambrian Research, Vol. 64, pp. 3-21.Baltic ShieldTectonics - East European Platform
DS2000-0095
2000
Bogdanova, S.Bogdanova, S., Claesson, S., et al.Paleoproterozoic accretionary tectonics in the western part of the east European craton... Eurobridge seismicsIgc 30th. Brasil, Aug. abstract only 1p.EuropeCraton - Sarmatia, Lithuanian terrane, Tectonics
DS200712-0088
2006
Bogdanova, S.Bogdanova, S., Gorbatschev, R., Grad, M., Janik, T., Guterch, A., Kozlovskaya, E., Motuza, G., SkridaiteEUROBRIDGE: new insight into the geodynamic evolution of the East European Craton.Geological Society of London Memoir, No. 32, pp. 599-626.EuropeCraton
DS200712-0189
2006
Bogdanova, S.Claesson, S., Bibikova, E., Bogdanova, S., Skobelev, V.Archean terranes. paleoproterozoic reworking and accretion in the Ukrainian shield, East European Craton.Geological Society of London Memoir, No. 32, pp. 645-654.Europe, Ukraine, UralsCraton
DS1996-0149
1996
Bogdanova, S.V.Bogdanova, S.V., Pashkevich, Goratschev, OrlyukRiphean rifting and major Paleoproterozoic crustal boundaries in the basement of the East European CratonTectonophysics, Vol. 268, pp.1-21.Baltic States, Europe, UralsTectonics, Geophysics - MGSAT.
DS1996-0150
1996
Bogdanova, S.V.Bogdanova, S.V., Pashkevich, I.K., Orlyuk, M.I.Riphean rifting and major Paleoproterozooic crustal boundaries in the basement of the East European CratonTectonophysics, Vol. 268, No. 1/4, Dec. 31, pp. 1-22.EuropeGeology, geophysics, Craton - East European
DS1996-1297
1996
Bogdanova, S.V.Shchipanksy, A.A., Bogdanova, S.V.The Sarmatian crustal segment: Precambrian correlation between the Voronezh Massif and the Ukrainian Shield.Tectonophysics, Vol. 268, No. 1/4, Dec. 31, pp. 109-126.UKrainePrecambrian, Aulocogen
DS2001-0118
2001
Bogdanova, S.V.Bogdanova, S.V., Page, L.M., Skridlaite, G., Taran, L.Proterozoic tectonothermal history in the western part of the East European Craton: 40 Ar 39 Ar constraints..#2Tectonophysics, Vol. 339, No. 1-2, pp. 39-66.EuropeGeochronology, Craton
DS2001-0119
2001
Bogdanova, S.V.Bogdanova, S.V., Page, L.M., Skridlaite, G., Taran, L.N.Proterozoic tectonothermal history in the western part of the East European Craton: 40 Ar 39 Ar constraints #1Tectonophysics, Vol. 339, No. 1-2, pp. 183-92.EuropePaleomagnetics, Tectonics
DS2001-0195
2001
Bogdanova, S.V.Claesson, S., Bogdanova, S.V., Bibikova, GorbatschevIsotopic evidence for Paleoproterozoic accretion in the basement of the East European Craton.Tectonophysics, Vol. 339, No. 1-2, pp. 1-18.EuropeGeochronology, Craton
DS2003-0127
2003
Bogdanova, S.V.Bogdanova, S.V.The Meso to Neoproterozoic evolution of the East European CratonGeological Society of America, Annual Meeting Nov. 2-5, Abstracts p.343.Scandinavia, Poland, Ukraine, BalticaTectonics
DS200412-0175
2003
Bogdanova, S.V.Bogdanova, S.V.The Meso to Neoproterozoic evolution of the East European Craton.Geological Society of America, Annual Meeting Nov. 2-5, Abstracts p.343.Europe, Scandinavia, Baltic ShieldTectonics
DS201811-2560
2018
Bogdanova, S.V.Claesson, S., Artemenko, G.V., Bogdanova, S.V., Shumlyanskyy, L.Archean crustal evolution in the Ukrainian shield.Earth's Oldest Rocks, Springer , Chapter 33, pp. 872-889.Europe, Ukrainetectonics
DS1988-0067
1988
Bogdanova, V.I.Bogdanova, V.I., Kulagina, D.A.Spectrophotometric determination of sulfur In kimberlite rocks by the absorption of molybdenum blue.(Russian)Fiz. Khim. Metody Analiza Mineralov I Avtomatiz. Anal., Rabot, 1988 pp. 5-11RussiaSpectrophotometry, Kimberlites
DS1993-1045
1993
Bogdanovsky, O.G.Mineyev, S.D., Bogdanovsky, O.G., Veksler, I.V., Karpenko, S.F.Isotopic classification of mantle magmas: effects from low degrees ofmelting.Geochemistry International, Vol. 30, No. 7, pp. 24-33.MantleBasaltic magmas, Geochronology
DS1981-0088
1981
Bogdasarov, E.A.Bogdasarov, E.A., Landa, E.A., Markovskiy, A.A.Chemical Composition and Crystallization Conditions of Chrome Spinels of Volcanic Ultramafics and Other Rocks of the Mafic Ultramafic Series.International Geology Review, Vol. 23, No. 9, PP. 931-RussiaKimberlite, Spinels, Mineralogy
DS1982-0107
1982
Bogdasarov, I.A.Bogdasarov, I.A., Danilin, E.L.Dalbykha Carbonatite MassifDoklady Academy of Sciences AKAD. NAUK SSSR., Vol. 267, No. 6, PP. 1440-1443.RussiaBlank
DS1997-0108
1997
Bogden, G.J.Bogden, G.J.Merger and acqusition trends in the mining industryInsight Press, Canada, GlobalEconomics, discoveries, Mergers
DS2002-0180
2002
Bogden, G.J.Bogden, G.J.Mergers & acquisitions: where do we go from here?Minerals & Energy, Vol. 17, 3, pp. 32-44.GlobalEconomics - mentions diamonds, financings, list
DS200612-0145
2006
Bogden, G.J.Bogden, G.J.Consolidation among the juniors - is it time.Insight Mining Business and Investment Forum, Held June 5-6, Toronto, 18p. Xerox of slides onlyGlobalEconomics - consolidation - not specific to diamonds
DS1988-0068
1988
Boger, L.W.Boger, L.W.GEOSTAT: a computer system for spherical semi-variogram modeling andkrigingUnited States Geological Survey (USGS) Open File, No. 88-684, 47pGlobalComputer, Program - GEOSTAT.
DS2001-0120
2001
Boger, S.D.Boger, S.D., Wilson, C.J.L., Fanning, C.M.Early Proterozoic tectonism within the East Antarctic Craton : final suture between East and West GondwanaGeology, Vol. 29, No. 5, May, pp. 463-6.GlobalTectonics, Rodinia
DS201412-0058
2014
Boger, S.D.Boger, S.D., Hirdes, W., Ferreira, C.A.M., Jenett, T., Dallwig, R., Fanning, C.M.The 580-520 Ma Gondwana suture of Madagascar and its continuation into Antarctica and Africa.Gondwana Research, in press available 14p.Africa, MadagascarShield - Arabian Nubian
DS201509-0385
2015
Boger, S.D.Boger, S.D., Hirdes, W., Ferreira, C.A.M., Jenett, T., Dallwig, R., Fanning, C.M.The 580-520 Ma Gondwana suture of Madagascar and its continuation into Antarctica and Africa.Gondwana Research, Vol. 28, pp. 1048-1060.Africa, MadagascarTectonics

Abstract: U-Pb age data from southwest Madagascar provide a compelling case that the pre-Gondwana Indian plate was stitched with the arc terranes of the Arabian Nubian Shield along a suture that closed between 580 Ma and 520 Ma. The key observations supportive of this interpretation are: (1) metamorphism dated to 630-600 Ma is manifested only on the west side of the suture in rocks that have affinities with the oceanic and island arc terranes of the Arabian Nubian Shield, or which represent continental rocks welded to these terranes prior to the amalgamation of Gondwana, and (2) orogenesis at 580-520 Ma is manifest in rocks on both sides of the suture, an observation taken to mark the timing of collision and to reflect spatial continuity across the suture. In southwest Madagascar the distribution of metamorphic ages places the suture along the Beraketa high-strain zone, the tectonic boundary between the Androyen and Anosyen domains. Similar age relationships allow for the extrapolation of this tectonic boundary into both East Antarctica and Africa.
DS201905-1017
2019
Boger, S.D.Boger, S.D., Maas, R., Pastuhov, M., Macey, P.H., Hirdes, W., Schulte, B., Fanning, C.M., Ferreira, C.A.M., Jenett, T., Dallwig, R.The tectonic domains of southern and western Madagascar.Precambrian Research, Vol. 327, pp. 144-175.Africa, Madagascarplate tectonics

Abstract: Southern and western Madagascar is comprised of five tectonic provinces that, from northeast to southwest, are defined by the: (i) Ikalamavony, (ii) Anosyen, (iii) Androyen, (iv) Graphite and (v) Vohibory Domains. The Ikalamavony, Graphite and Vohibory Domains all have intermediate and felsic igneous protoliths of tonalite-trondhjemite-granodiorite-granite composition, with positive ?Nd, and low Sr and Pb isotopic ratios. All three domains are interpreted to be the products of intra-oceanic island arc magmatism. The protoliths of the Ikalamavony and Graphite Domains formed repectively between c. 1080-980?Ma and 1000-920?Ma, whereas those of the Vohibory Domain are younger and date to between c. 670-630?Ma. Different post-formation geologic histories tie the Vohibory-Graphite and Ikalamavony Domains to opposite sides of the pre-Gondwana Mozambique Ocean. By contrast, the Androyen and Anosyen Domains record long crustal histories. Intermediate to felsic igneous protoliths in the Androyen Domain are of Palaeoproterozoic age (c. 2200-1800?Ma), of tonalite-trondhjemite-granodiorite-granite composition, and show negative ?Nd, moderate to high 87Sr/86Sr and variable Pb isotopic compositions. The felsic igneous protoliths of the Anosyen Domain are of granitic composition and, when compared to felsic gneisses of the Androyen Domain, show consistently lower Sr/Y and markedly higher Sr and Pb isotope ratios. Like the Vohibory and Graphite Domains, the Androyen Domain can be linked to the western side of the Mozambique Ocean, while the Anosyen Domain shares magmatic and detrital zircon commonalities with the Ikalamavony Domain. It is consequently linked to the opposing eastern side of this ocean. The first common event observed in all domains dates to c. 580-520?Ma and marks the closure of the Mozambique Ocean. The trace of this suture lies along the boundary between the Androyen and Anosyen Domains and is defined by the Beraketa high-strain zone.
DS2002-0558
2002
Boggiani, P.C.Gesicki, A.L.D., Riccomini, C., Boggiani, P.C.Ice flow direction during late Paleozoic glaciation in western Parana Basin, BrasilJournal of South American Earth Sciences, Vol.14, 8, March pp. 933-9.BrazilGeomorphology
DS1991-0869
1991
Boggs, C.J.King, J.M., Boggs, C.J.Legal due diligence- the skeletons in the closetMining Engineering, Vol. 43, No. 10, October pp. 1255-1261GlobalLegal, Environmental
DS1995-1715
1995
BoginaSharkov, E.V., Sarelainen, B.V., Quick, J.E., Lazko, BoginaArbanksy Massif in the eastern Siberia -the largest in Russia block of the Early Precambrian upper mantle.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 506-8.Russia, SiberiaArbansky Massif, Eclogites
DS200912-0060
2009
BoginaBogatikov, O.A., Sharkov, E.V., Bogina, Kononova, Nosova, Samsonov, ChistyakovWithin plate (intracontinental) and postorogenic magmatism of the East European Craton as reflection of the evolution of continental lithosphere.Petrology, Vol. 17, 3, May pp. 207-226.RussiaMagmatism
DS1996-1289
1996
Bogina, M.Sharkov, E.V., Bogatikov, O.A., Kovalenko, V.I., Bogina, M.Petrology and geochemistry of continental and oceanic magmatic and metamorphic rocks. - Early Prec. eclogitesRussian Geology and Geophysics, Vol. 37, No. 1, pp. 85-102.Russia, Kola Peninsula, SayanEclogites, Baltic Shield
DS201502-0043
2015
Bogina, M.Bogina, M., Zlobin, V., Sharkov, E., Chistyakov, A.Petrogenesis of siliceous high-Mg series rocks as exemplified by the Early Paleoproterozoic mafic volcanic rocks of the Eastern Baltic Shield: enriched mantle versus crustal contamination.Economic Geology Research Institute 2015, Vol. 17,, #3510, 1p. AbstractRussiaPlume geodynamics

Abstract: The Early Paleoproterozoic stage in the Earth's evolution was marked by the initiation of global rift systems, the tectonic nature of which was determined by plume geodynamics. These processes caused the voluminous emplacement of mantle melts with the formation of dike swarms, mafic-ultramafic layered intrusions, and volcanic rocks. All these rocks are usually considered as derivatives of SHMS (siliceous high-magnesian series). Within the Eastern Baltic Shield, the SHMS volcanic rocks are localized in the domains with different crustal history: in the Vodlozero block of the Karelian craton with the oldest (Middle Archean) crust, in the Central Block of the same craton with the Neoarchean crust, and in the Kola Craton with a heterogeneous crust. At the same time, these rocks are characterized by sufficiently close geochemical characteristics: high REE fractionation ((La/Yb)N = 4.9-11.7, (La/Sm)N=2.3-3.6, (Gd/Yb)N =1.66-2.74)), LILE enrichment, negative Nb anomaly, low to moderate Ti content, and sufficiently narrow variations in Nd isotope composition from -2.0 to -0.4 epsilon units. The tectonomagmatic interpretation of these rocks was ambiguous, because such characteristics may be produced by both crustal contamination of depleted mantle melts, and by generation from a mantle source metasomatized during previous subduction event. Similar REE patterns and overlapping Nd isotope compositions indicate that the studied basaltic rocks were formed from similar sources. If crustal contamination en route to the surface would play a significant role in the formation of the studied basalts, then almost equal amounts of contaminant of similar composition are required to produce the mafic rocks with similar geochemical signatures and close Nd isotopic compositions, which is hardly possible for the rocks spaced far apart in a heterogeneous crust. This conclusion is consistent with analysis of some relations between incompatible elements and their ratios. In particular, the rocks show no correlation between Th/Ta and La/Yb, (Nb/La)pm ratio and Th content, and eNd and (Nb/La)N ratio. At the same time, some correlation observed in the eNd-Mg# and (La/Sm)N-(Nb/La)N diagrams in combination with the presence of inherited zircons in the rocks does not allow us to discard completely the crustal contamination. Examination of Sm/Yb-La/Sm relations and the comparison with model melting curves for garnet and spinel lherzolites showed that the parental melts of the rocks were derived by 10-30% mantle melting at garnet-spinel facies transition. Two stage model can be proposed to explain such remarkable isotope-geochemical homogeneity of the mafic volcanic rocks over a large area: (1) ubiquitous emplacement of large volumes of sanukitoid melts in the lower crust of the shield at 2.7 Ga; (2) underplating of plume-derived DM melts at the crust-mantle boundary, melting of the lower crust of sanukitoid composition, and subsequent mixing of these melts with formation of SHMS melts at 2.4 Ga. A simple mixing model showed that in this case the Nd isotope composition of obtained melts remained practically unchanged at variable amounts of contaminant (up to 30%). This work was supported by the RFBR no. 14-05-00458.
DS201612-2335
2016
Bogina, M.Sharkov, E., Bogina, M., Chistyakov, A.Magmatic systems of large continental igneous provinces.Geoscience Frontiers, in press availableRussiaMagmatism

Abstract: Large igneous provinces (LIPs) formed by mantle superplume events have irreversibly changed their composition in the geological evolution of the Earth from high-Mg melts (during Archean and early Paleoproterozoic) to Phanerozoic-type geochemically enriched Fe-Ti basalts and picrites at 2.3 Ga. We propose that this upheaval could be related to the change in the source and nature of the mantle superplumes of different generations. The first generation plumes were derived from the depleted mantle, whereas the second generation (thermochemical) originated from the core-mantle boundary (CMB). This study mainly focuses on the second (Phanerozoic) type of LIPs, as exemplified by the mid-Paleoproterozoic Jatulian-Ludicovian LIP in the Fennoscandian Shield, the Permian-Triassic Siberian LIP, and the late Cenozoic flood basalts of Syria. The latter LIP contains mantle xenoliths represented by green and black series. These xenoliths are fragments of cooled upper margins of the mantle plume heads, above zones of adiabatic melting, and provide information about composition of the plume material and processes in the plume head. Based on the previous studies on the composition of the mantle xenoliths in within-plate basalts around the world, it is inferred that the heads of the mantle (thermochemical) plumes are made up of moderately depleted spinel peridotites (mainly lherzolites) and geochemically-enriched intergranular fluid/melt. Further, it is presumed that the plume heads intrude the mafic lower crust and reach up to the bottom of the upper crust at depths ?20 km. The generation of two major types of mantle-derived magmas (alkali and tholeiitic basalts) was previously attributed to the processes related to different PT-parameters in the adiabatic melting zone whereas this study relates to the fluid regime in the plume heads. It is also suggested that a newly-formed melt can occur on different sides of a critical plane of silica undersaturation and can acquire either alkalic or tholeiitic composition depending on the concentration and composition of the fluids. The presence of melt-pockets in the peridotite matrix indicates fluid migration to the rocks of cooled upper margin of the plume head from the lower portion. This process causes secondary melting in this zone and the generation of melts of the black series and differentiated trachytic magmas.
DS201909-2084
2019
Bogina, M.M.Sharkov, E.V., Chisyakov, A.V., Bogina, M.M., Bogatikov, O.A., Sjchiptsov, V.V., Belyatsky, B.V., Frolov, P.V.Ultramafic - alkaline - carbonatite complexes as a result of two stage melting of a mantle plume: from the Mid- Paleoproterozoic Tiksheozero intrusion, northern Karelia, Russia.Doklady Earth Sciences, Vol. 486, 2, pp. 638-643.Russia, Kareliacarbonatite

Abstract: The Tiksheozero ultramafic-alkaline-carbonatite intrusive complex, like numerous carbonatite-bearing complexes of similar composition, is a part of a large igneous province related to the ascent of a thermochemical mantle plume. The geochemical and isotopic data indicate that the formation of the ultramafic and alkaline rocks was related to crystallization differentiation of a primary alkali picritic melt, whereas carbonatite magmas were derived from an independent mantle source. We suggest that the origin of parental magmas of the Tiksheozero Complex, as well as other ultramafic-alkaline-carbonatite complexes, was provided by two-stage melting of the mantle-plume head: (1) adiabatic melting of its inner part generated moderately alkaline picrites, the subsequent fractional crystallization of which led to the appearance of alkaline magmas, and (2) incongruent melting of the upper cooled margin of the plume head under the influence of CO2-rich fluids, which arrived from underlying adiabatic melting zone, gave rise to carbonatite magmas.
DS202110-1635
2021
Bogina, M.M.Sharkov, E.V., Chistyakov, A.V., Bogina, M.M., Shchiptsov, V.V., Belyatsky, B.V., Frolov, P.V.Petrology of the Mid-Paleoproterozoic Tiksheozero ultramafic-alkaline-carbonatite complex, ( Northern Karelia).Petrology, Vol. 29, 5, pp. 475-501. pdfRussia, Kareliadeposit - Tiksheozero

Abstract: The paper reports first comprehensive geological, petrographic, mineralogical, and geochemical data on one of the world’s oldest Tiksheozero ultramafic?alkaline?carbonatite complex (~1.99 Ga), which belongs to the Mid-Paleoproterozoic igneous province of the Baltic Shield. The complex was formed in three intrusive phases. The first phase is composed of the low-alkali mafic?ultramafic rocks: dunites, wehrlites, clinopyroxenites, and gabbro. The rocks of the second phase are alkaline ultramafic rocks represented mainly by jacupirangites (alkaline clinopyroxenites) and foidolites (melteigites, ijoliltes, and urtites), with subordinate olivinites, alkaline gabbro, and nepheline syenites. The third intrusive phase is made up of carbonatites. Geochemical and mineralogical data indicate that all three phases were derived from different primary melts. It is shown that the nepheline syenites were obtained by fractionation of foidolites. A model of formation of such complexes through decompressional melting of mantle plume head enriched in carbonate fluid is proposed.
DS1996-0151
1996
Bognikov, V.I.Bognikov, V.I., Pavlov, A.L., Polyakov, G.V.The platinum group elements in the Atalyk ultrabasite basite intrusion, Gornyy AltayDoklady Academy of Sciences USSR, Vol. 336, pp. 92-97Russiaplatinum group elements (PGE), Layered intrusion, Deposit -Atalyk
DS200512-0721
2004
Bogolepova, O.K.Metelkin, D.V., Vernikovsky, V.A., Kazansky, A.Y., Bogolepova, O.K., Gubanov, A.P.Paleozoic history of the Kara microcontinent and its relation to Siberia and Baltica: paleomagnetism, paleogeography and tectonics.Tectonophysics, Vol. 398, 3-4, April 13, pp. 225-243.Russia, Siberia, Baltic ShieldTectonics
DS1980-0305
1980
Bogomol'naya, L.S.Shemanina, YE.I., Bogomol'naya, L.S.Inclusions in Uralian Diamonds and their Probable OriginTsnigri, No. 153, PP. 89-95.RussiaBlank
DS2003-0947
2003
Bogomolov, E.S.Miller, Y.V., Lvov, A.B., Myskova, T.A., Bogomolov, E.S., Pushkarev, Y.D.Search for ancient continental crust at the junction of the Karelian craton - BelomorianDoklady Earth Sciences, Vol. 389A, 3, pp. 302-5.Russia, KareliaTectonics
DS2003-0948
2003
Bogomolov, E.S.Miller, Yu.V., Lvov, A.B., Myskova, T.A., Bogomolov, E.S., Pushkarev, Yu.D.Search for ancient continental crust at the junction of the Karelian Craton-BelomorianDoklady Earth Sciences, Vol. 389A, 3, March-April, pp. 302-6.RussiaCraton
DS200412-1311
2003
Bogomolov, E.S.Miller, Y.V., Lvov, A.B., Myskova, T.A., Bogomolov, E.S., Pushkarev, Y.D.Search for ancient continental crust at the junction of the Karelian craton - Belomorian mobile belt: evidence from isotope geocDoklady Earth Sciences, Vol. 389A, 3, pp. 302-5.Russia, KareliaTectonics
DS200512-0845
2005
Bogomolov, E.S.Perov, V.A., Bogomolov, E.S., Larchenko, V.A., Levskii, L.K., Minchenko, G.V., Sablukov, S.M., SZergeev, S.A., Stepanov, V.P.Rb Sr age of kimberlites of the Pionerskaya pipe, Arkangelsk Diamondiferous province.Doklady Earth Sciences, Vol. 400, 1, pp. 67-71.Russia, Kola Peninsula, ArchangelGeochronology -
DS200512-0847
2005
Bogomolov, E.S.Pervov, V.A., Bogomolov, E.S., Larchenko, V.A., Levskii, L.K., Minchenko, Sabukov, Sergeev, StepanovRb Sr age of kimberlites of the Pionerskaya pipe, Arkangelsk Diamondiferous province.Doklady Earth Sciences, Vol. 400, 1, pp. 67-71.Russia, Archangel, Kola PeninsulaGeochronology
DS200612-1083
2006
Bogomolov, E.S.Pervov, V.A., Larchenko, V.A., Minchenko, G.V., Stepanov, V.P., Bogomolov, E.S., Levskii, SergeevTiming and duration of kimberlitic magmatism in the Zimnii Bereg Diamondiferous province: evidence from Rb Sr age dat a on kimberlitic sills along the Mela River.Doklady Earth Sciences, Vol. 407, 2, Feb-Mar. pp. 304-307.RussiaGeochronology - Zimnii Bereg
DS201012-0238
2010
Bogomolov, E.S.Glebovitskii, R.V.A., Nikitina, L.P., Pushkarev, Y.D., Vrevskii, A.B., Goncharov, A.G., Bogomolov, E.S.Sm and Nd geochemistry of mantle xenoliths: the problem of mantle material classification.Doklady Earth Sciences, Vol. 433, 1, pp. 890-893.MantleMantle magmatism
DS201212-0419
2012
Bogomolov, E.S.Lokhov, K., Lukyanova, L., Antonev, A.V., Polekhovsky, I.N., Antonov, A.V., Afanasev, Z.L., Bogomolov, E.S., Sergeev, S.A.U Pb and Lu-Hf isotopic systems in zircons and Hf-Nd isotopic systemization of the Kimozero kimberlites, Karelia.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, Archangel, Kola PeninsulaDeposit - Kimozero
DS201412-0838
2013
Bogomolov, E.S.Skublov, S.G., Melnik, A.E., Marin, Yu.B., Berezin, A.V., Bogomolov, E.S., Ishmurzin, F.I.New dat a on the age ( U-Pb, Sm-Nd) of metamorphism and a protolith of eclogite like rocks from the Krasnaya Guba area, Belomorian belt.Doklady Earth Sciences, Vol. 451, 1, pp. 1156-1164.RussiaEclogite
DS201802-0256
2017
Bogomolov, E.S.Nikitina, L.P., Bogomolov, E.S., Kyrmsky, R.Sh., Belyatsky, B.V., Korolev, N.M., Zinchenko, V.N.Nd Sr Os systems of eclogites in the lithospheric mantle of the Kasai Craton ( Angola).Russian Geology and Geophysics, Vol. 58, pp. 1305-1316.Africa, Angolaeclogites

Abstract: We studied the Sm-Nd, Rb-Sr, and Re-Os isotope compositions of mantle xenoliths (eclogites and peridotites) from diamondiferous kimberlites of the Catoca cluster of the Kasai Craton. In the eclogites, the primary strontium isotope composition 87Sr/86Sr varies from 0.7056 to 0.7071, and the neodymium isotope composition eNd, from 1.8 to 2.6. The 187Re/188Os and 187Os/188Os ratios range from 135 to 80 and from 1.3110 to 1.9709, respectively, which indicates a significant portion of radiogenic Os: yOs = 129-147. These isotope values exceed the values assumed for model reservoirs (primitive upper mantle (PUM) and bulk silicate Earth (BSE)) and those of chondrites. The isotope composition of the studied systems indicates the formation of eclogites from a rhenium-enriched source, namely, the subducted oceanic crust transformed as a result of metasomatism and/or melting under upper-mantle conditions.
DS202006-0942
2020
Bogomolov, E.S.Nikitina, L.P., Goncharov, A.G., Bogomolov, E.S., Beliatsky, B.V., Krimsky, R.Sh., Prichodko, V.S., Babushkina, M.S., Karaman, A.A.HFSE and REE geochemistry and Nd-Sr-Os systematics of peridotites in the subcontinental lithospheric mantle of the Siberian craton and central Asian fold belt junction area: data on mantle xenoliths.Petrology, Vol. 28, 2, pp. 207-219.RussiaREE

Abstract: Mantle xenoliths were found in alkaline basalts of Tokinsky Stanovik (TSt) in the Dzhugdzhur-Stanovoy superterrane (DS) and Vitim plateau (VP) in the Barguzin-Vitim superterrane (BV) (Stanovoy suture area) at junction of the Central Asian Orogenic Belt (CAOB) and the Siberian craton (SC). Xenoliths from TSt basalts are represented by spinel lherzolites, harzburgites, wehrlites; while VP basalts frequently contain spinel-garnet and garnet peridotites lherzolites, and pyroxenites. Xenoliths in kimberlites of the Siberian craton are mainly represented by garnet-bearing lherzolites with abundant eclogite xenoliths (age of 2.7-3.1 Ga), which were not found in mantle of superterranes. The Re-Os determinations point to the Early Archean age of peridotites and eclogites from mantle beneath the Siberian craton. The major and trace (rare-earth and high-filed strength) elements and Nd-Sr-Os composition were analyzed in the peridotites (predominant rocks) of lithospheric mantle at junction of the Central Asian Orogenic Belt and Siberian Craton. The degree of rock depletion in CaO and Al2O3 and enrichment in MgO relative to the primitive mantle in the peridotites of the Dzhugdzhur-Stanovoy superterrane is close to that of the Siberian craton. The peridotites of the Barguzin-Vitim superterrane are characterized by much lower degree of depletion and have mainly a primitive composition. Mantle melting degree reaches up to 45-50% in the Siberian Craton and Dzhugdzhur-Stanovoy superterrane, and is less than 25% in the Barguzin-Vitim terrane. The mantle peridotites of the craton as compared to those of adjacent superterranes are enriched in Ba, Rb, Th, Nb, and Ta and depleted in Y and REE from Sm to Lu. However, all studied peridotites are characterized by mainly superchondritic values of Nb/Ta (>17.4), Zr/Hf (>36.1), Nb/Y (>0.158), and Zr/Y (>2.474). The Nb/Y ratio is predominantly >1.0 in SC peridotites and < 1.0 in the superterrane peridotites. The Nd and Sr isotopic compositions in the latter correspond to those of oceanic basalts. The 187Os/188Os ratio is low (0.108-0.115) in the peridotites of the Siberian Craton and > 0.115 but usually lower than 0.1296 (primitive upper mantle value) in the peridotites of the Dzhugdzhur-Stanovoy and Barguzin-Vitim superterranes. Thus, the geochemical and isotopic composition of peridotites indicates different compositions and types of mantle beneath the Siberian craton and adjacent superterranes of the Central Asian Orogenic Belt in the Early Archean, prior to the formation of 2.7-3.1 Ga eclogites in the cratonic mantle.
DS1991-0141
1991
Bogue, S.Bogue, S.Reversals of opinionNature, Vol. 351, June 6, p. 445-446GlobalGeophysics -mantle, Magnetics, Paleomagnetics
DS1991-0142
1991
Bogue, S.Bogue, S.Geomagnetism: reversals of opinionNature, Vol. 351, No. 6326, June 6, p. 445GlobalGeophysics, GeomagnetisM.
DS1995-0166
1995
Bogue, S.W.Bogue, S.W., Gromme, S., Hillhouse, J.W.Paleomagnetism, magnetic anisotropy and mid-Cretaceous paleolatitude of Duke Island Alaska ultramafic complexTectonics, Vol. 14, No. 5, October pp. 1133-1152AlaskaPaleomagnetism, Duke Island Complex
DS202004-0549
2020
Bogush, I.Zedgenizov, D., Bogush, I., Shatsky, V., Kovalchuk, O., Ragozin, A., Kalinina, V.Mixed habit type Ib-IaA diamond from an Udachnaya eclogite.Minerals MDPI, Vol. 9, 9120741, 12p. PdfRussiadeposit - Udachnaya

Abstract: The variety of morphology and properties of natural diamonds reflects variations in the conditions of their formation in different mantle environments. This study presents new data on the distribution of impurity centers in diamond type Ib-IaA from xenolith of bimineral eclogite from the Udachnaya kimberlite pipe. The high content of non-aggregated nitrogen C defects in the studied diamonds indicates their formation shortly before the stage of transportation to the surface by the kimberlite melt. The observed sectorial heterogeneity of the distribution of C- and A-defects indicates that aggregation of nitrogen in the octahedral sectors occurs faster than in the cuboid sectors.
DS200612-1180
2005
Bogush, I.N.Rotman, A.Y., Bogush, I.N., Tarskikh, O.V.Kimberlites of Yakutia: standard and anomalous indications.Problems of Sources of deep magmatism and plumes., pp. 114-147.Russia, YakutiaMineral chemistry
DS201212-0697
2012
Bogush, I.N.Spetsius, Z.V., Kovalchuck, O.E., Bogush, I.N.Properties of diamonds in xenoliths from kimberlites of Yakutia: implication to their origin and exploration.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, YakutiaXenoliths
DS201502-0107
2015
Bogush, I.N.Spetsius, Z.V., Bogush, I.N., Kovalchuk, O.E.FTIR mapping of diamond plates of eclogitic and peridotitic xenoliths from Nyurbinskaya pipe, Yakutia: genetic implications.Russian Geology and Geophysics, Vol. 56, 1, pp. 344-353.RussiaDeposit - Nyurbinskaya
DS201606-1125
2005
Bogush, I.N.Vasiley, E.A., Ivanov-Omskii, V.I., Bogush, I.N.Institial carbon showing up in the absorption spectra of natural diamonds. Technical Physics ** in ENG, Vol. 50, 6, pp. 711-714.TechnologyNitrogen

Abstract: Natural diamonds are studied by Fourier-transform IR (FTIR) spectroscopy, and it is shown that B2 centers in them form through intermediate stages, which are accompanied by the appearance of absorption bands with maxima near 1550 and 1526 cm?1. The concentration of interstitial carbon atoms in the centers responsible for these bands may be several times higher than the concentration of the interstitials in B 2 defects.
DS201804-0742
2018
Bogush, I.N.Spetsius, Z.V., Bogush, I.N., Ivanov, A.S.Xenolith of eclogites with diamonds from the Yubileinaya kimberlite pipe.Doklady Earth Sciences, Vol. 478, 1, pp. 88-91.Russia, Yakutiadeposit - Yubilienaya

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

Abstract: The first studies of diamonds in eclogitic xenoliths from the Komsomolskaya kimberlite pipe are described. Among round and oval-shaped xenoliths with diamond ingrowths, samples with a garnet content of 40-90% of the xenolith volume dominate. Two eclogite samples contain grains of accessory rutile; a kyanite sample is also revealed. Certain samples contain two or more crystals of diamonds. Diamonds with an octahedral habit and crystals with transitional habits, which belong to an octahedral-rhombic dodecahedral row, dominate in eclogites; there are many variety VIII aggregates. A high concentration of structural nitrogen, commonly in the A form, was registered in most of the crystals. Diamonds with a small content of nitrogen impurities, 40-67% in the B1 form, are present in a number of xenoliths. The calculated temperatures of the formation of eclogitic xenoliths is 1100-1300°C. Diversity in the impurity compositions of diamonds in the same xenolith shows that these diamonds were formed at various times and in different settings. The diamond position in xenoliths, the various level of nitrogen aggregation in the diamonds, and a number of other factors point to the later formation of the diamonds, as compared to minerals of eclogites, from fluid or fluid-melts in the process of metasomatosis.
DS202204-0524
2022
Bogush, I.N.Kedrova, T.V., Bogush, I.N., Zinchuk, N.N., Bardukhinov, L.D., Lipashova, A.N., Saltykova, V.P.Diamond placers of the Nakyn kimberlite field.Russian Geology and Geophysics, Vol. 63, 3, pp. 245-254.Russiadeposit - Nakyn

Abstract: The paper presents the results of studies of diamonds from Early Jurassic sediments making up the Nyurbinskoe buried placer of the Nakyn kimberlite field, unique in diamond reserves. The main task is to identify diamond distribution patterns in the deposits of the Dyakhtar Stratum (lower deposit) and the Ukugut Suite (upper deposit) within the placer. A comparative analysis of the typomorphic features of diamonds from the upper and lower deposits of the placer was carried out. Variations in the contents of crystals with certain properties that form the image of a diamond-bearing geologic object have been revealed. The zonal distribution of diamonds by characteristics in sedimentary deposits, regardless of their age, has been established. The properties of diamonds and their associations change within the placer, which is due to their redeposition during the Early Jurassic sedimentation.
DS200712-0089
2007
Boguslavskii, M.A.Boguslavskii, M.A.The geological and geochemical revision of the Komsomolskaya pipe reserves.Moscow University Geology Bulletin, Vol. 62, 4, pp. 286-288.Russia, YakutiaDeposit - Komsomolskaya
DS201012-0064
2009
Boguslavskii, M.A.Boguslavskii, M.A., Burnistrov, A.A.Petrophysical properties of kimberlites from the Komsomolsky Pipe and their relationship to its composition, formation conditions and diamond content.Moscow University Geology Bulletin, Vol. 64, 6, Dec. pp. 354-363.Russia, YakutiaDeposit - Komsomolsy
DS202109-1469
2021
Bohav, T.Good, D.J., Hollings, P., Dunning, G., Epstein, R., McBride, J., Jedemann, A., Magnus, S., Bohav, T., Shore, G.A new model for the Coldwell Complex and associated dykes of the Midcontinent Rift, Canada.Journal of Petrology, Vol. 62, 7, 10.1093/petrology/ega036Canadadeposit - Coldwell

Abstract: Mafic intrusions on the NE shoulder of the Midcontinent Rift (Keweenawan LIP), including Cu-PGE mineralized gabbros within the Coldwell Complex (CC), and rift parallel or radial dykes outside the CC are correlated based on characteristic trace element patterns. In the Coldwell Complex, mafic rocks are subdivided into four groups: (1) early metabasalt; (2) Marathon Series; (3) Layered Series; (4) Geordie-Wolfcamp Series. The Marathon Series are correlated with the rift radial Abitibi dykes (1140?Ma), and the Geordie-Wolfcamp Series with the rift parallel Pukaskwa and Copper Island dykes. U-Pb ages determined for five gabbros from the Layered and Marathon Series are between 1107•7 and 1106•0?Ma. Radiogenic isotope ratios show near chondritic (CHUR) ?Nd(1106?Ma) and 87Sr/86Sri values that range from -0•38 to +1•13 and 0•702537 to 0•703944, respectively. Distinctive geochemical properties of the Marathon Series and Abitibi dykes, such as Ba/La (14-37), Th/Nb (0•06-0•12), La/Sm (3•8-7•7), Sr/Nd (21-96) and Zr/Sm (9-19), are very different from those of the Geordie-Wolfcamp Series and a subset of Copper Island and Pukaskwa dykes with Ba/La (8•7-11), Th/Nb (0•12-0•13), La/Sm (6•7-7•9), Sr/Nd (5-7•8) and Zr/Sm (18-24). Each unit exhibits covariation between incompatible element ratios such as Zr/Sm and Nb/La or Gd/Yb, Sr/Nd and Ba/La, and Nb/Y and Zr/Y, which are consistent with mixing relationship between two or more mantle domains. These characteristics are unlike those of intrusions on the NW shoulder of the MCR, but resemble those of mafic rocks occurring in the East Kenya Rift. The results imply that an unusual and long-lived mantle source was present in the NE MCR for at least 34?Myr (spanning the 1140?Ma Abitibi dykes and the 1106?Ma Marathon series) and indicate potential for Cu-PGE mineralization in an area much larger than was previously recognized.
DS1997-0109
1997
Bohay, T.J.Bohay, T.J.The Coldwell alkaline complex: magmatic affinity as determined by an isotopic and geochemical study.McMaster University of, MSc. 122p.OntarioAlkaline rocks, Coldwell Complex
DS1989-0002
1989
Boher, M.Abouchamy, W., Boher, M., Michard, A., Albarede, E., et al.Crustal growth in West Africa at 2.1 Ga: preliminary resultsEos, Vol. 70, No. 15, April 11, p. 485. (abstract.)West Africa, Mauritania, Senegal, Mali, Guinea, Ivory CoastGhana, Burkina Faso, Tectonics, Geochronology
DS1992-0138
1992
Boher, M.Boher, M., Abouchami, W., Michard, A., Albarede, F., Arndt, N.T.Crustal growth in West Africa at 2.1 GaJournal of Geophysical Research, Vol. 97, No. B1, January 10, pp. 345-369GlobalGeophysics, Craton
DS1989-0136
1989
Bohlen, S.R.Bohlen, S.R., Mezger, K.Origin of granulite terranes and the formation of the lowercontinentalcrustScience, Vol. 244, April 21, pp. 326-329. Database # 17814GlobalCrust, Granulite terranes
DS1991-0143
1991
Bohlen, S.R.Bohlen, S.R.On the formation of granulitesJournal of Metamorphic Geology, Vol. 9, No. 3, May pp. 223-230GlobalGranulites, Alteration, metamorphism
DS1992-0890
1992
Bohlen, S.R.Koziol, A.M., Bohlen, S.R.Solution properties of almandine-pyrope garnet as determined by phase equilibrium experimentsAmerican Mineralogist, Vol. 77, No. 7, 8 July-August pp. 765-773GlobalGeothermometry, Experimental petrology -garnet
DS1995-0167
1995
Bohlen, S.R.Bohlen, S.R., Mosenfelder, J.L.The coesite to quartz transformation: nature vs experimentEos, Vol. 76, No. 46, Nov. 7. p.F531. Abstract.GlobalCoesite, Petrology -experimental
DS1996-0997
1996
Bohlen, S.R.Mosenfelder, J.L., Bohlen, S.R.The quartz coesite transition revisited: revisitedGeological Society of America, Abstracts, Vol. 28, No. 7, p. A-159.GlobalCoesite
DS1998-1046
1998
Bohlen, S.R.Mosenfelder, J.L., Bohlen, S.R.Kinetics of the coesite to quartz transformationEarth and Planetary Science Letters, Vol. 153, No. 1-2, pp. 133-147.GlobalUltrahigh pressure, Subduction
DS1997-0110
1997
Bohling, G.C.Bohling, G.C.GSLIB- style programs for discriminate analysis and regionalizedclassificationComputers and geosciences, Vol. 23, No. 7, pp. 739-761GlobalGeostatistics, reserves, Computer - GSLIB.
DS201112-0160
2011
BohmChakmouradian, A.R., Bohm, Coeslan, Mumin, Reguir, Demeny, Simonetti, Kressall, Martins, Kamenov, Creaser, LepekhinaPostorogenic carbonatites: more abundant than we realize and more important than given credit for.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.17-19.Canada, ManitobaCinder Lake, Eden Lake, Paint Lake
DS201112-0161
2011
BohmChakmouradian, A.R., Bohm, Coeslan, Mumin, Reguir, Demeny, Simonetti, Kressall, Martins, Kamenov, Creaser, LepekhinaPostorogenic carbonatites: more abundant than we realize and more important than given credit for.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.17-19.Canada, ManitobaCinder Lake, Eden Lake, Paint Lake
DS200412-1958
2004
Bohm, C.Syme, R., Bohm, C.Manitoba's kimberlite potential.PDAC 2004, 1p. abtract.Canada, ManitobaBrief overview
DS2002-0181
2002
Bohm, C.O.Bohm, C.O., Heaman, L.M., Creaser, R.A., Corkery, SternTectonic assembly of the Trans Hudson: Superior boundary zone in northern Manitoba: Paleoarchean crustGac/mac Annual Meeting, Saskatoon, Abstract Volume, P.11., p.11.ManitobaCollision, Geochronology
DS2002-0182
2002
Bohm, C.O.Bohm, C.O., Heaman, L.M., Creaser, R.A., Corkery, SternTectonic assembly of the Trans Hudson: Superior boundary zone in northern Manitoba: Paleoarchean crustGac/mac Annual Meeting, Saskatoon, Abstract Volume, P.11., p.11.ManitobaCollision, Geochronology
DS2003-0128
2003
Bohm, C.O.Bohm, C.O., Heaman, L.M.Kimberlite potential of the NW Superior Craton and Superior boundary zoneManitoba Annual Convention, Nov. 13, 1/4p. abstract.ManitobaNews item - craton, hotspot
DS200412-0176
2004
Bohm, C.O.Bohm, C.O., Bowerman, M.S.Superior margin program news. (Gull Rapids area mentions... dykes .. potential for kimberlites)Manitoba Geological Survey, Report of Activities Nov. 18-20, abstractCanada, ManitobaTectonics
DS200412-0177
2003
Bohm, C.O.Bohm, C.O., Heaman, L.M.Kimberlite potential of the NW Superior Craton and Superior boundary zone.Manitoba Geological Survey, Nov. 13, 1/4p. abstract.Canada, ManitobaNews item - craton, hotspot
DS200412-0178
2004
Bohm, C.O.Bohm, C.O., Kasycki, C.A., Lenton, P.G., Syme, E.C., Keller, G.R., Matile, G.L.Revealing Manitoba's hidden kimberlites.Geological Association of Canada Abstract Volume, May 12-14, SS14-01 p. 260.abstractCanada, ManitobaBrief overview of structure, stratigraphy
DS200412-0179
2004
Bohm, C.O.Bohm, C.O., Keller, G.R.Exploring the Manitoba kimberlite indicator mineral database.Manitoba Geological Survey, Report of Activities Nov. 18-20, abstractCanada, ManitobaGeochemistry - database
DS200512-0101
2005
Bohm, C.O.Bohm, C.O., Corrigan, D., Corkery, T.M., Zwanzig, Lenton, Coyyle, ThomasRe-mapping the northern Superior Trans Hudson boundary by using newly acquired high resolution aeromagnetic data.GAC Annual Meeting Halifax May 15-19, Abstract 1p.Canada, Manitoba, Saskatchewan, OntarioGeophysics - magnetics
DS200612-0546
2006
Bohm, C.O.Hartlaub, R.P., Heaman, L.M., Simonetti, A., Bohm, C.O.Relicts of Earth's crust: U Pb, Lu Hf and morphological characteristics of > 3.7 Ga detrital zircon of the western Canadian Shield.Geological Society of America, Processes on the Earth, Special Paper 405, Chapter 5.CanadaGeochronology
DS200812-0192
2008
Bohm, C.O.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
DS200912-0061
2008
Bohm, C.O.Bohm, C.O., Anderson, S.D., Matile, G.L.D., Keller, G.R.Geochemical and kimberlite indicator mineral results for till samples from Nejanilini, Kasmere and Putahow lakes areas, northern Manitoba NTS 64N 64 O 64 P.Manitoba Geological Survey, OF 2008-13, CDCanada, ManitobaGeochemistry
DS201012-0094
2009
Bohm, C.O.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
DS201905-1018
2019
Bohm, C.O.Bohm, C.O., Hartlaub, R.P., Heaman, L.M., Cates, N., Guitreau, M., Bourdon, B., Roth, A.S.G., Mojzsis, S.J., Blichert-Toft, J.The Assean Lake Complex: ancient crust at the northwestern margin of the Superior Craton, Manitoba, Canada.Earths Oldest Rocks, researchgate.com Chapter 28, 20p. Pdf availableCanada, Manitobacraton

Abstract: This chapter describes the Assean Lake Complex (ALC) at ancient crust at the Northwestern margin of the Superior Craton, Manitoba, and Canada. An initial tectonic model for the Assean Lake area indicated that a regionally extensive high-strain zone running through the lake marks the suture between Archean high-grade crustal terranes of the Superior Craton to the southeast and Paleoproterozoic rocks of the Trans-Hudson Orogen to the northwest. Detailed geologic remapping combined with isotopic and geochemical studies led to a re-interpretation of the crust immediately north of the Assean Lake high-strain zone as Mesoarchean. The study area straddles the boundary between the Archean Superior Craton and the ca.1.90-1.84 Ga arc and marginal basin rocks of the Trans-Hudson Orogen, which represent the remains of ca. 1.83-1.76 Ga ocean closure and orogeny. It is indicated that the gneisses of the Split Lake Block consist primarily of meta-igneous protoliths of gabbroic to granitic composition. Tonalite and granodiorite are the most volumetrically dominant, but an anorthosite dome is also present in the northeast. Mapping, isotopic, and age data combined with high-resolution aero-magnetic data indicate that the Mesoarchean ALC is a crustal slice up to 10 km wide, and has a strike length of at least 50 km.
DS202002-0167
2019
Bohm, C.O.Bohm, C.O., Hartlaub, R.P., Heaman, L.M., Cates, N., Guitreau, M., Bourdon, B., Roth, A.S.G., Mojzsis, S.J., Blichert-Toft, J.The Assean Lake Complex: ancient crust at the northwestern margin of the Superior craton, Manitoba, Canada. ( not specific to diamonds)Earth's Oldest Rocks, Chapter 28, 20p. Pdf.Canada, Manitobacraton
DS200812-0124
2008
Bohn, B.Bohn, B.The role of the volatile phase for REE and Y fractionation in low- silica carbonate magmas: implications from natural carbonatites, Namibia.Mineralogy and Petrology, Vol. 92, 3-4, pp. 453-470.Africa, NamibiaCarbonatite
DS2001-0658
2001
Bohn, M.Laverne, C., Agriniet, P., Hermitte, D., Bohn, M.Chemical fluxes during hydrothermal alteration of 1200 m long section of dikes in the oceanic crust Hole 504B.Chemical Geology, Vol. 181,No. 1-4, pp. 73-98.GlobalDike - sheeted, ophiolite, dolerite, Geochemistry
DS2002-0105
2002
Bohn, M.Barrat, J.A., Jambon, A., Bohn, M., Gillet, P., Sautter, V., Gopei, C., Lesourd, M.Petrology and chemistry of the picritic shergottite north west AfricaGeochimica et Cosmochimica Acta, Vol.66, 19, pp.3505-18.West AfricaPicrites
DS1986-0844
1986
Bohnene, K.P.Vonderlinden, H., Fulde, P., Bohnene, K.P.Efficient approach to the abinitio Hartree Rock problem ofsolids, with application to diamond and siliconPhys. Rev. B., Vol. 34, No. 2, July 15, pp. 1063-1070GlobalDiamond morphology
DS1993-0858
1993
Bohor, B.F.Krogh, T.E., Kamo, S.L., Bohor, B.F.Fingerprinting the K T impact site and determining the time of impact by Ulead dating of single shocked zirconsEarth and Planetary Science Letters, Vol. 119, pp. 425-9.ColoradoGeochronology, Manson impact site
DS1997-0111
1997
Bohrson, W.A.Bohrson, W.A., et al.Rethinking the chemical heterogeneity of the mantleEos, Vol. 78, No. 25, June 24, p. 257, 262.MantleGeochemistry, Magmas
DS1998-0464
1998
Bohrson, W.A.Gans, P.B., Bohrson, W.A.Suppression of volcanism during rapid extension in the Basin and Rangeprovince, United StatesScience, Vol. 279, No. 5347, Jan. 2, pp. 66-68Nevada, Basin and Rangevolcanism., tectonics
DS201709-1962
2017
Bohrson, W.A.Borisova, A.Y., Zagrtdenov, N.R., Toplis, M.J., Bohrson, W.A., Nedelec, A., Safonov, O.G., Pokrovski, G.S., Ceileneer, G., Melnik, O.E., Bychkov, A.Y., Gurenko, A.A., Shscheka, S., Terehin, A., Polukeev, V.M., Varlamov, D.A., Gouy, S., De Parseval, P.Making Earth's continental crust from serpentinite and basalt. Goldschmidt Conference, abstract 1p.Mantleperidotites

Abstract: How the Earth's continental crust was formed in the Hadean eon is a subject of considerable debates [1-4]. For example, shallow hydrous peridotites [2,5], in particular the Hadean Earth's serpentinites [6], are potentially important ingredients in the creation of the continental ptoto-crust, but the mechanisms of this formation remain elusive. In this work, experiments to explore serpentinite-basalt interaction under conditions of the Hadean Earth were conducted. Kinetic runs lasting 0.5 to 48 hours at 0.2 to 1.0 GPa and 1250 to 1300°C reveal dehydration of serpentinite and release of a Si-Al-Na-K-rich aqueous fluid. For the first time, generation of heterogeneous hydrous silicic melts (56 to 67 wt% SiO2) in response to the fluid-assisted fertilisation and the subsequent partial melting of the dehydrated serpentinite has been discovered. The melts produced at 0.2 GPa have compositions similar to those of the bulk continental crust [2,3]. These new findings imply that the Earth's sialic proto-crust may be generated via fluid-assisted melting of serpentinized peridotite at shallow depths (?7 km) that do not require plate subduction during the Hadean eon. Shallow serpentinite dehydration and melting may be the principal physico-chemical processes affecting the earliest lithosphere. Making Earth's continental crust from serpentinite and basalt.
DS202201-0018
2022
Bohrson, W.A.Heinonen, J.S., Spera, F.J., Bohrson, W.A.Thermodynamic limits for assimilation of silicate crust in primitive magmas.Geology, Vol. 50, 1, pp. 81-85.Mantlemagmatism

Abstract: Some geochemical models for basaltic and more primitive rocks suggest that their parental magmas have assimilated tens of weight percent of crustal silicate wall rock. But what are the thermodynamic limits for assimilation in primitive magmas? We pursue this question quantitatively using a freely available thermodynamic tool for phase equilibria modeling of open magmatic systems—the Magma Chamber Simulator (https://mcs.geol.ucsb.edu)—and focus on modeling assimilation of wall-rock partial melts, which is thermodynamically more efficient compared to bulk assimilation of stoped wall-rock blocks in primitive igneous systems. In the simulations, diverse komatiitic, picritic, and basaltic parental magmas assimilate progressive partial melts of preheated average lower, middle, and upper crust in amounts allowed by thermodynamics. Our results indicate that it is difficult for any subalkaline primitive magma to assimilate more than 20?30 wt% of upper or middle crust before evolving to compositions with higher SiO2 than a basaltic magma (52 wt%). On the other hand, typical komatiitic magmas have thermodynamic potential to assimilate as much as their own mass (59?102 wt%) of lower crust and retain a basaltic composition. The compositions of the parental melt and the assimilant heavily influence both how much assimilation is energetically possible in primitive magmas and the final magma composition given typical temperatures. These findings have important implications for the role of assimilation in the generation and evolution of, e.g., ultramafic to mafic trans-Moho magmatic systems, siliceous high-Mg basalts, and massif-type anorthosites.
DS200612-1337
2006
Bohse, H.Sorensen, H., Bohse, H., Bailey, J.C.The origin and mode of emplacement of lujavrites in the Ilmaussaq alkaline complex, South Greenland.Lithos, in press availableEurope, GreenlandAlkaline rocks, agpaitic nepeheline syenites
DS1989-0137
1989
Boillot, G.Boillot, G., Feraud, G., Recq, M., Girardeau, J.Undercrusting by serpentinite beneath rifted marginsNature, Vol. 341, October 12, pp. 523-525. Database # 18207SpainTectonics, Mantle
DS2000-0864
2000
Boillot, G.Scharer, U., Girardeau, J., Cornen, G., Boillot, G.138-121 Ma asthenospheric magmatism prior continental breakup in the North Atlantic geodynamic implications.Earth and Planetary Science Letters, Vol.181, No.4, Sept.30, pp.555-72.GlobalMagmatism, Tectonics - rifting, continental margin
DS1989-0138
1989
Boily, M.Boily, M., Ludden, J., Gauthier, G.Geochemical studies of the Hearst Matachewan Preissac and Kapuskasing dyke swarms in the Kapuskasing structural zoneGeological Association of Canada (GAC) Annual Meeting Program Abstracts, Vol. 14, p. A123. (abstract.)OntarioTectonics, Kapuskasing Zone
DS1990-0219
1990
Boily, M.Boily, M., Williams-Jones, A.E., Salvi, S.A reappraisal of the geology and geochemistry of the Zr-Y-Nb-Be and rare earth elements (REE)mineralized Strange Lake peralkalinepluton, Quebec-LabradorGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) Vancouver 90 Program with Abstracts, Held May 16-18, Vol. 15, p. A12. AbstractQuebec, LabradorArfvedsonite, Rare earths
DS1991-0144
1991
Boily, M.Boily, M., Ludden, J.N.Trace element and neodymium isotopic variations in Early Proterozoic dyke swarms emplaced in the vicinity of the Kapuskasing structural zone. enriched mantleAFC.Canadian Journal of Earth Sciences, Vol. 28, pp. 26-36.OntarioAssimilation fractional crystallization, Tectonics, rifting, dike swarms
DS1991-0145
1991
Boily, M.Boily, M., Ludden, J.N.Trace-element and neodymium isotopic variations in Early Proterozoic dyke swarms emplaced in the vicinity of Kapuskasing Structural zone : enriched mantle orAFC?Canadian Journal of Earth Sciences, Vol. 28, No. 1, January pp. 26-36OntarioGeochronology, Kapuskasing Structural Zone
DS2002-0183
2002
Boily, M.Boily, M., Dion, C.Geochemistry of boninite type volcanic rocks in the Frotet Evans greenstone belt, Opawica subprovince Quebec: implications for the evolution of Archean beltsPrecambrian Research, Vol. 115, No.1-4, pp. 349-71.QuebecBoninites
DS1950-0322
1957
Boineau, R.Boineau, R.La Series de la Bouenza dans la Compare Sibiti-ouestAef Dir. Mines Et Geol., SECT. B. No. 8, PP. 17-19.GlobalGeology, Diamond
DS200612-0996
2006
Boiocchi, M.Oberti, R., Quartieri, S., Dalconi, M.C., Boscherini, F., Iezzi, G., Boiocchi, M., Eeckhout, S.G.Site preference and local geometry of Sc in garnets: part 1. multifarious mechanisms in the pyrope-grossular join.American Mineralogist, Vol. 91, 9, pp. 1230-1239.TechnologyMineral chemistry - garnets
DS1993-0132
1993
Bois, C.Bois, C.Orogenic belts and sedimentary basins. Thoughts on crustal evolution suggested by deep seismic reflection imagesBulletin Societe Geologique France, Vol. 164, No. 3, pp. 327-342CrustBasins, Geophysics -seismics
DS1993-0133
1993
Bois, C.Bois, C.Orogenic belts and sedimentary basins. Thoughts on crustal evolution suggested by deep seismic reflection images. (in French)Bulletin Societe Geologique France, (in French), No. 3, pp. 327-342.GlobalOrogeny, Geophysics -seismics
DS1860-0730
1892
Boise City StatesmanBoise City StatesmanDiamond Discovery. an Interesting talk with an acknowledged expert.Boise City Statesman., Dec. 15TH.United States, Idaho, Rocky MountainsDiamond Occurrence
DS1860-0731
1892
Boise City StatesmanBoise City StatesmanOur Idaho DiamondsBoise City Statesman., Dec. 22ND.United States, Idaho, Rocky MountainsDiamond Occurrence
DS1987-0065
1987
Boissavyvinau, M.Boissavyvinau, M.Diamonds from outer space.(in French)L Recherche (in French), Vol. 18, No. 192, October pp. 1250-153GlobalMeteorites
DS1993-0394
1993
Boisvert, D.R.Edwards, W.A.D., Boisvert, D.R.Tertiary (preglacial) gravel formations -an aggregate and placer gold resource of heavy mineral indicator dataThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin) , Annual Meeting Abstracts approximately 10 lines, Vol. 86, No. 968, March POSTER ABSTRACT p. 68AlbertaGeomorphology, Mineral chemistry
DS1995-1430
1995
Boisvert, E.Parent, M., Paradis, S.J., Boisvert, E.Ice flow patterns and glacial transport in the eastern Hudson Bay region:Laurentide ice sheet dynamicsCanadian Journal of Earth Sciences, Vol. 32, No. 12, Dec. pp. 2057-2070.OntarioGeomorphology, Quaternary dynamics
DS1984-0240
1984
Boivan, P.A.Dostal, J., Boivan, P.A.Geochemistry and Petrology of Ultramafic Xenoliths and Their Host Basalts from Tallante, Southern Spain.Geological Association of Canada (GAC), Vol. 9, P. 58. (abstract.).SpainRelated Rocks, Lherzolite
DS200912-0227
2008
Boivin, P.France, L., Ouillon, N., Chazot, G., Kornprobst, J., Boivin, P.CMAS 3D a new program to visualize and project major element composites in the CMAS system.Computers & Geosciences, in press availableTechnologyMineral chemistry - not specific to diamonds
DS201509-0396
2015
Boivin, P.France, L., Chazot, G., Kornprobst, J., Dallai, L., Vannucci, R., Gregoire, M., Bertrand, H., Boivin, P.Mantle refertilization and magmatism in old orogenic regions: the role of late-orogenic pyroxenites.Lithos, Vol. 232, pp. 49-75.Africa, Morocco, Cameroon, Jordan, Europe, FranceXenoliths

Abstract: Pyroxenites and garnet pyroxenites are mantle heterogeneities characterized by a lower solidus temperature than the enclosing peridotites; it follows that they are preferentially involved during magma genesis. Constraining their origin, composition, and the interactions they underwent during their subsequent evolution is therefore essential to discuss the sources of magmatism in a given area. Pyroxenites could represent either recycling of crustal rocks in mantle domains or mantle originated rocks (formed either by olivine consuming melt-rock reactions or by crystal fractionation). Petrological and geochemical (major and trace elements, Sr-Nd and O isotopes) features of xenoliths from various occurrences (French Massif-Central, Jordan, Morocco and Cameroon) show that these samples represent cumulates crystallized during melt percolation at mantle conditions. They formed in mantle domains at pressures of 1-2 GPa during post-collisional magmatism (possibly Hercynian for the French Massif-Central, and Panafrican for Morocco, Jordan and Cameroon). The thermal re-equilibration of lithospheric domains, typical of the late orogenic exhumation stages, is also recorded by the samples. Most of the samples display a metasomatic overprint that may be either inherited or likely linked to the recent volcanic activity that occurred in the investigated regions. The crystallization of pyroxenites during late orogenic events has implications for the subsequent evolution of the mantle domains. The presence of large amounts of mantle pyroxenites in old orogenic regions indeed imparts peculiar physical and chemical characteristics to these domains. Among others, the global solidus temperature of the whole lithospheric domain will be lowered; in turn, this implies that old orogenic regions are refertilized zones where magmatic activity would be enhanced.
DS201112-0307
2011
Boix, M.Estrade, G., Salvi, S., Beziat, D., Boix, M.HFSE enrichment in a peralkaline granite-related zircon rich skarn in the Cenozoic Ampasindava alkaline complex, Madagascar.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.42-44.Africa, MadagascarREE
DS201112-0308
2011
Boix, M.Estrade, G., Salvi, S., Beziat, D., Boix, M.HFSE enrichment in a peralkaline granite-related zircon rich skarn in the Cenozoic Ampasindava alkaline complex, Madagascar.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.42-44.Africa, MadagascarREE
DS201312-0085
2013
Bojakowska, I.Bojakowska, I.Trace elements in CatAnd a carbonatitic Massif ( SW Angola)Goldschmidt 2013, AbstractAfrica, AngolaGeochemistry
DS201312-0981
2013
Bojakowska, I.Wolkowicz, S., Bojakowska, I., Wolkowicz, K., Tadeusz, S.Trace elements in CatAnd a carbonatitic massif (SW Angola).Goldschmidt 2013, 1p. AbstractAfrica, AngolaCarbonatite
DS2001-0401
2001
Bojdys, G.Grabowska, T., Bojdys, G.The border of the East European Craton in south Eastern Poland based on gravity and magnetic data.Terra Nova, Vol. 13, pp. 92-98.Poland, EuropeGeophysics - gravity, Craton
DS2003-0129
2003
Bojinski, S.Bojinski, S., Schaepman, M., Schlapfer, D., Itten, K.SPECCHIO: a spectrum database for remote sensing applicationsComputers and Geosciences, Vol. 29, 1, pp. 27-38.GlobalComputer - program, Not specific to diamonds
DS200612-0146
2005
Bokalo, S.P.Bokalo, S.P., Kurbatov, K.K., Bescrovanov, V.V.Typomorphic pecularities of giant Yakutian diamonds. **** in RussianMineralogical Museums Symposium, St. Petersburg, Russia, *** RUSSIAN, pp. 333-334. abstract desc @alrosa.mir.ruRussiaDeposit - Mir
DS201012-0862
2010
Bokelmann, G.Wusterfeld, A., Bokelmann, G., Barruol, G.Evidence for ancient lithospheric deformation in the East European Craton based on mantle seismic anisotropy and crustal magnetics.Tectonophysics, Vol. 481, pp. 16-28.EuropeGeophysics - seismics
DS2000-0096
2000
Bokelmann, G.H.Bokelmann, G.H.Deformation in the deep Canadian shield and plate mantle couplingGeological Society of America (GSA) Abstracts, Vol. 32, No. 7, p.A-164.Canada, Northwest Territories, OntarioMechanical interaction
DS200612-1501
2005
Bokelmann, G.H.Walker, K.T., Bokelmann, G.H., Klemperer, S.L., Bock, G.Shear wave splitting around the Eifel hotspot: evidence for a mantle upwelling.Geophysical Journal International, Vol. 163, 3,Dec. pp. 962-980.Europe, GermanyGeophysics - seismics
DS1992-0139
1992
Bokelmann, G.H.R.Bokelmann, G.H.R., Silver, P.G.Mantle variation within the Canadian ShieldEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p. 204Wyoming, OntarioCraton, Structure
DS2000-0097
2000
Bokelmann, G.H.R.Bokelmann, G.H.R., Harjes, H.P.Evidence for temporal variation of seismic velocity within the upper continental crust.Journal of Geophysical Research, Vol. 105, No.B 10, Oct.10, pp.23879-MantleGeophysics - seismics
DS2002-0184
2002
Bokelmann, G.H.R.Bokelmann, G.H.R.Which forces drive North America?Geology, Vol. 30, 11, Nov. pp. 1027-30.MantleTectonics, deformation lithosphere, geophysics, seismics
DS2002-0185
2002
Bokelmann, G.H.R.Bokelmann, G.H.R., Silver, P.G.Shear stress at the base of shield lithosphereGeophysical Research Letters, Vol. 29, 23, Dec. 01, 6p. DOI 10.1029/2002GLO15925MantleGeophysics - seismics
DS200512-1160
2005
Bokelmann, G.H.R.Walker, K.T., Bokelmann, G.H.R., Klemperer, S.L., Nyblade, A.Shear wave splitting around hotspots: evidence for upwelling related mantle flow?Plates, Plumes, and Paradigms, pp. 171-192. ( total book 861p. $ 144.00)GlobalGeophysics - seismics
DS200912-0062
2009
Bokelmann, G.H.R.Bokelmann, G.H.R., Wustefeld, A.Comparing crustal and mantle fabric from the North American Craton using magnetics and seismic anisotropy.Earth and Planetary Science Letters, Vol. 277, 3-4, Jan. 30, pp. 355-364.Canada, Northwest TerritoriesGeophysics - geochronology
DS1986-0085
1986
Bokii, G.B.Bokii, G.B., Bexrukov, G.N., Klyuev, Yu.A., Naletov, A.M., Nepsha, V.I.Natural and synthetic diamonds.(Russian)Nauka Moscow (Russian), 224pRussiaDiamond
DS1984-0162
1984
Bokiy, G.B.Bokiy, G.B., Nikitin, A.V., Pepin, S.V.Chemical Transport of Carbon by Nitrogen Containing Intermediates in Natural Diamond Synthesis.Doklady Academy of Science USSR, Earth Science Section., Vol. 266, No. 1-6, MAY PP. 169-172.RussiaGenesis, Diamond Morphology
DS1996-1061
1996
Bokreta, M.Ottonello, G., Bokreta, M., Sciuto, P.F.Parameterization of energy and interactions in garnets: end memberproperties.American Mineralogist, Vol. 81, pp. 429-7.GlobalMineralogy - garnets
DS1987-0066
1987
Boland, A.V.Boland, A.V., Ellis, R.M.A crustal scale seismic refraction experiment over the Kapuskasing structural zone, northern OntarioEos, Vol. 68, No. 44, November 3, p. 1356. abstract onlyOntarioGeophysics
DS1989-0139
1989
Boland, A.V.Boland, A.V.Paleogeotherm and paleostrength profiles for the late Archean crust as constrained by seismic thickness estimates and a surface cross sectionalexposureEos, Vol. 70, No. 43, October 24, p. 1321. AbstractOntario, MidcontinentIvanhoe Lake cataclastic Zone, Tectonics
DS1989-0140
1989
Boland, A.V.Boland, A.V., Ellis, R.M.Seismic refraction and potential field interpretation of the Kapuskasing structural zoneGeological Association of Canada (GAC) Annual Meeting Program Abstracts, Vol. 14, p. A103. (abstract.)OntarioTectonics, Kapuskasing zone
DS1991-0146
1991
Boland, A.V.Boland, A.V., Ellis, R.M.A geophysical model for the Kapuskasing uplift from seismic and gravitystudiesCanadian Journal of Earth Sciences, Vol. 28, No. 3, March pp. 342-354OntarioTectonics, Kapuskasing uplift
DS1992-1653
1992
Boland, A.V.White, D.J., Boland, A.V.A comparison of forward modeling and inversion of seismic first arrivalsover the Kapuskasing UpliftSeismological Soc. of American Bulletin, Vol. 82, No. 1, February pp. 304-322OntarioGeophysics -seismics, Tectonics, Kapuskasing Uplift
DS1975-0466
1977
Boland, J.N.Boland, J.N., Buiskool, Toxopur, J.M.A.Dislocation Deformation Mechanisms in Peridotite Xenoliths In Kimberlites.Contributions to Mineralogy and Petrology, Vol. 60, No. 1, PP. 17-30.South AfricaPetrology
DS201802-0223
2018
Boldyrev, K.N.Boldyrev, K.N., Mavrin, B.N., Sherin, P.S., Popova, M.N.Bright luminescence of diamonds with GeV centers.Journal of Luminescence, Vol. 193, pp. 119-124.Technologyluminescence

Abstract: We report on the quantum yield (?) and decay time (?) measurements at room temperature for the bright red-orange (602 nm) luminescence from new germanium-vacancy (Ge-V) centers in nano- and microcrystalline diamonds synthesized at high pressure and high temperature. The values ? = 3 ± 1% and ? = 6.2±0.2 ns were found. The Stokes shift measured as the energy difference between the maxima of the luminescence and luminescence excitation spectra is negligible. The relative intensity of the zero-phonon line constitutes up to 70% from the total intensity of the luminescence. Results of our ab initio DFT calculations for the ground-state electronic and vibrational structure of (Ge-V)? in diamond are presented and discussed.
DS202205-0674
2022
Boldyrev, K.N.Boldyrev, K.N., Sedov, V.S., Vanpoucke, D.E.P., Ralchenko, V.G., Mavrin, B.N.Photoluminescence and first principles phonon study.Diamond and Related Materials, Vol. 126, 6p. PdfGlobalLuminescence
DS2002-0186
2002
Bolfan Casanova, N.Bolfan Casanova, N., Mackwell, S., Keppler, H., McCammon, C., Rubie, D.C.Pressure dependence of H solibility in magnesiowustite up to 25 GPa: implications forGeophysical Research Letters, Vol. 29,10,May15,pp.89-MantleGeochemistry
DS200712-0090
2006
Bolfan Casanova, N.Bolfan Casanova, N., McCammon, C.A., Mackwell, S.J.Water in transition zone and lower mantle minerals.American Geophysical Union, Geophysical Monograph, No. 168, pp. 57-68.MantleWater
DS200712-0353
2006
Bolfan Casanova, N.Gautron, L., Greaux, S., Andrault, D., Bolfan Casanova, N., Guignot,N., Bouhifd, M.A.Uranium in the Earth's lower mantle.Geophysical Research Letters, Vol. 33, 23, Dec. 16, L23301MantleUranium
DS2000-0098
2000
Bolfan-Casanova, N.Bolfan-Casanova, N., Keppler, H., Rubie, D.C.Water partioning between nominally anhydrous minerals in the MgO SiO2 H2O system up to 24 GPa's...Earth and Planetary Science Letters, Vol. 182, No. 3-4, Nov. 15, pp. 209-21.MantleWater in the earth's mantle - distribution
DS2001-0030
2001
Bolfan-Casanova, N.Andrault, D., Bolfan-Casanova, N., Guignot, N.Equation of state of lower mantle ( Al Fe MgSiO3) perovskiteEarth and Planetary Science Letters, Vol. 193, No. 3-4, pp.501-8.MantleGeochemistry, Perovskite
DS2002-0043
2002
Bolfan-Casanova, N.Andrault, D., Bolfan-Casanova, N., Guignot, N.Effect of aluminum on lower mantle mineralogy18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.76.MantleUHP mineralogy - perovskite
DS2003-0130
2003
Bolfan-Casanova, N.Bolfan-Casanova, N., Keppler, H., Rubie, D.C.Water partitioning at 660 km depth evidence for very low water solubility in magnesiumGeophysical Research Letters, Vol. 30, 17, 1905 DOI.1029/2003GLO17182MantlePerovskite
DS200412-0180
2003
Bolfan-Casanova, N.Bolfan-Casanova, N., Keppler, H., Rubie, D.C.Water partitioning at 660 km depth evidence for very low water solubility in magnesium silicate perovskite.Geophysical Research Letters, Vol. 30, 17, 1905 DOI.1029/2003 GLO17182MantlePerovskite
DS200512-0102
2005
Bolfan-Casanova, N.Bolfan-Casanova, N.Water in the Earth's mantle.Mineralogical Magazine, Vol. 69, 3, June, pp. 229-258.MantleWater
DS200712-0091
2007
Bolfan-Casanova, N.Bolfan-Casanova, N.Fuel for plate tectonics.Science, Vol. 315, Jan. 19, pp. 338-339.MantleTectonics
DS200712-0092
2007
Bolfan-Casanova, N.Bolfan-Casanova, N., Bali, E., Koga, K.Pressure and temperature dependence of water solubility in forsterite: implications for the activity of water in the Earth's mantle.Plates, Plumes, and Paradigms, 1p. abstract p. A106.MantleWater
DS200812-0075
2008
Bolfan-Casanova, N.Bali, E., Bolfan-Casanova, N., Koga, K.T.Pressure and temperature dependence of H solubility in forsterite: an implication to water activity in the Earth interior.Earth and Planetary Science Letters, Vol. 268, no. 3-4, April. 30, pp. 354-363.MantleWater
DS201012-0007
2010
Bolfan-Casanova, N.Andrault, D., Munoz, M., Bolfan-Casanova, N., Guigot, N., Schouten, J-P.Experiment evidence for perovskite and post perovskite coexistence throughout the whole 'D' region.Earth and Planetary Science Letters, Vol. 293, 1-2, pp. 90-96.MantleBoundary
DS201012-0008
2010
Bolfan-Casanova, N.Andrault, D., Nigro, G., Bolfan-Casanova, N., Bouhifd, M.A., Garbarino, G., Mezouar, M.Melting curve of the lowermost Earth's mantle.Goldschmidt 2010 abstracts, abstractMantleMelting
DS201112-0020
2011
Bolfan-Casanova, N.Andrault, D., Bolfan-Casanova, N., loNigro, G., Bouhifd, M.A., Garbarino, G., Mezouar, M.Solidus and liquidus profiles of chrondritic mantle: implications for melting of the Earth across its history.Earth and Planetary Science Letters, Vol. 304, 1-2, pp. 251-259.MantleMelting
DS201112-0021
2011
Bolfan-Casanova, N.Andrault, D., Lo Nigro, G., Bolfan-Casanova, N., Bouhifd, M.A., Garbarino, G., Mezouar, M.Melting properties of chronditic mantle to the core mantle boundary.Goldschmidt Conference 2011, abstract p.438.MantleMelting
DS201212-0200
2012
Bolfan-Casanova, N.Ferot, A., Bolfan-Casanova, N.Water storage capacity in olivine and pyroxene to 14 Gpa: implications for the water content of the Earth's upper mantle and nature of seismic discontinuities.Earth and Planetary Science Letters, Vol. 349-350, pp. 218-230.MantleWater storage
DS201212-0201
2012
Bolfan-Casanova, N.Ferot, A., Bolfan-Casanova, N.Water storage capacity in olivine and pyroxene to 14 Gpa as implications for the water content of the Earth's upper mantle and nature of seismic discontinuities.Earth and Planetary Science Letters, Vol. 349-350 pp. 218-230.MantleWater
DS201312-0086
2013
Bolfan-Casanova, N.Bolfan-Casanova, N.Iron oxidation state in serpentine during subduction: implications on the nature of the released fluids at depth.Goldschmidt 2013, AbstractMantleSubduction
DS201312-0089
2013
Bolfan-Casanova, N.Bouhifd, M.A., Andrault, D., Bolfan-Casanova, N.Thermodynamics of lower mantle minerals.Goldschmidt 2013, AbstractMantleMineralogy
DS201412-0010
2014
Bolfan-Casanova, N.Andrault,D., Pesce, G., Ali Bouhifd, M., Bolfan-Casanova, N., Henot, J-M., Mezouar, M.Melting of basalt at the core-mantle boundary.Science, Vol. 344, no. 6186, pp. 892-895.MantleSubduction
DS201507-0329
2015
Bolfan-Casanova, N.Novella, D., Bolfan-Casanova, N., Nestola, F., Harris, J.W.H2O in olivine and garnet inclusions still trapped in diamonds from the Siberian craton: implications for the water content of cratonic lithosphere peridotites.Lithos, Vol. 230, pp. 180-183.RussiaDeposit - Udachnaya
DS201509-0384
2015
Bolfan-Casanova, N.Baptiste, V., Demouchy, S., Keshav, S., Parat, F., Bolfan-Casanova, N., Condamine, P., Cordier, P.Decrease of hydrogen in corporation in forsterite from CO2-H2O rich kimberlitic liquid.American Mineralogist, Vol. 100, pp. 1912-1920.TechnologyHydrogen, water

Abstract: To test if hydrogen incorporation by ionic diffusion can occur between a volatile-rich kimberlitic liquid and forsterite, results of high-pressure and high-temperature experiments using a piston-cylinder apparatus at 1200–1300 °C and 1 GPa for durations of 1 min, 5 h, and 23 h, are reported here. Kim-berlitic liquid in the system CaO-MgO-Al 2 O 3-SiO 2-CO 2-H 2 O and synthetic forsterite single crystals were chosen as a first simplification of the complex natural kimberlite composition. Unpolarized Fourier transform infrared spectroscopy was used to quantify the concentrations of OH in the crystallographically oriented forsterite. Scanning electron microscopy, electron backscattered diffraction, electron microprobe analyses, and transmission electron microscopy were performed to identify the run products. After 5 and 23 h, a forsterite overgrowth crystallized with the same orientation as the initial forsterite single crystal. The kimberlitic liquid has crystallized as micrometer-scale euhedral forsterite neocrystals with random crystallographic orientations, as well as a nanoscale aluminous phase and a calcic phase. Despite theoretical water-saturation of the system and long duration, none of the initial forsterite single crystals display signs of hydration such as hydrogen diffusion profile from the border toward the center of the crystal. Most likely, the presence of CO 2 in the system has lowered the H 2 O fugacity to such an extent that there is no significant hydration of the starting forsterite single crystal or its overgrowth. Also, the presence of CO 2 enhances rapid forsterite crystal growth. Forsterite growth rate is around 2 × 10 8 mm 3 /h at 1250 °C. These experimental results suggest a deep mantle origin of the high OH content found in natural mantle-derived xenoliths transported in kimberlites, as reported from the Kaapvaal craton. In agreement with previous studies, it also points out to the fact that significant hydration must take place in a CO 2-poor environment.
DS201601-0014
2015
Bolfan-Casanova, N.Demouchy, S., Bolfan-Casanova, N.Distribution and transport of hydrogen in the lithospheric mantle: a review.Lithos, in press available 80p.MantleHydrogen

Abstract: Distribution and transport of hydrogen in the lithospheric mantle: a review.
DS201612-2282
2016
Bolfan-Casanova, N.Bureau, H., Frost, D.J., Bolfan-Casanova, N., Leroy, C.Diamond growth in mantle fluids.Lithos, Vol. 265, pp. 4-15.MantleDiamond morphology

Abstract: In the upper mantle, diamonds can potentially grow from various forms of media (solid, gas, fluid) with a range of compositions (e.g. graphite, C-O-H fluids, silicate or carbonate melts). Inclusions trapped in diamonds are one of the few diagnostic tools that can constrain diamond growth conditions in the Earth's mantle. In this study, inclusion-bearing diamonds have been synthesized to understand the growth conditions of natural diamonds in the upper mantle. Diamonds containing syngenetic inclusions were synthesized in multi-anvil presses employing starting mixtures of carbonates, and silicate compositions in the presence of pure water and saline fluids (H2O-NaCl). Experiments were performed at conditions compatible with the Earth's geotherm (7 GPa, 1300-1400 °C). Results show that within the timescale of the experiments (6 to 30 h) diamond growth occurs if water and carbonates are present in the fluid phase. Water promotes faster diamond growth (up to 14 mm/year at 1400 °C, 7 GPa, 10 g/l NaCl), which is favorable to the inclusion trapping process. At 7 GPa, temperature and fluid composition are the main factors controlling diamond growth. In these experiments, diamonds grew in the presence of two fluids: an aqueous fluid and a hydrous silicate melt. The carbon source for diamond growth must be carbonate (CO32) dissolved in the melt or carbon dioxide species in the aqueous fluid (CO2aq). The presence of NaCl affects the growth kinetics but is not a prerequisite for inclusion-bearing diamond formation. The presence of small discrete or isolated volumes of water-rich fluids is necessary to grow inclusion-bearing peridotitic, eclogitic, fibrous, cloudy and coated diamonds, and may also be involved in the growth of ultradeep, ultrahigh-pressure metamorphic diamonds.
DS201706-1101
2017
Bolfan-Casanova, N.Roberge, M., Bureau, H., Bolfan-Casanova, N., Raepsaet, C., Surble, S., Khodja, H., Auzende, A-L., Cordier, P., Fiquet, G.Chlorine in wadsleyite and ringwoodite: an experimental study.Earth and Planetary Science Letters, Vol. 467, pp. 99-107.Mantlechlorine

Abstract: We report concentrations of Chlorine (Cl) in synthetic wadsleyite (Wd) and ringwoodite (Rw) in the system NaCl-(Mg,?Fe)2SiO4 under hydrous and anhydrous conditions. Multi-anvil press experiments were performed under pressures (14-22 GPa) and temperatures (1100-1400?°C) relevant to the transition zone (TZ: 410-670 km depth). Cl and H contents were measured using Particle Induced X-ray Emission (PIXE) and Elastic Recoil Detection Analysis (ERDA) respectively. Results show that Cl content in Rw and Wd is significantly higher than in other nominally anhydrous minerals from the upper mantle (olivine, pyroxene, garnet), with up to 490 ppm Cl in anhydrous Rw, and from 174 to 200 ppm Cl in hydrous Wd and up to 113 ppm Cl in hydrous Rw. These results put constrains on the Cl budget of the deep Earth. Based on these results, we propose that the TZ may be a major repository for major halogen elements in the mantle, where Cl may be concentrated together with H2OH2O and F (see Roberge et al., 2015). Assuming a continuous supply by subduction and a water-rich TZ, we use the concentrations measured in Wd (174 ppm Cl) and in Rw (106 ppm Cl) and we obtain a maximum value for the Cl budget for the bulk silicate Earth (BSE) of 15.1 × 1022 g Cl, equivalent to 37 ppm Cl. This value is larger than the 17 ppm Cl proposed previously by McDonough and Sun (1995) and evidences that the Cl content of the mantle may be higher than previously thought. Comparison of the present results with the budget calculated for F (Roberge et al., 2015) shows that while both elements abundances are probably underestimated for the bulk silicate Earth, their relative abundances are preserved. The BSE is too rich in F with respect to heavy halogen elements to be compatible with a primordial origin from chondrites CI-like (carbonaceous chondrites CC) material only. We thus propose a combination of two processes to explain these relative abundances: a primordial contribution of different chondritic-like materials, including EC-like (enstatite chondrites), possibly followed by a distinct fractionation of F during the Earth differentiation due to its lithophile behavior compared to Cl, Br and I.
DS201711-2499
2017
Bolfan-Casanova, N.Andrault, D., Bolfan-Casanova, N., Bouhifd, M.A., Boujibar, A., Garbarino, G., Manthilake, G., Mezouar, M., Monteux, J., Parisiades, P., Pesce, G.Toward a coherent model for the melting behaviour of the deep Earth's mantle.Physics of the Earth and Planetary Interiors, Vol. 265, pp. 67-81.Mantlemelting

Abstract: Knowledge of melting properties is critical to predict the nature and the fate of melts produced in the deep mantle. Early in the Earth’s history, melting properties controlled the magma ocean crystallization, which potentially induced chemical segregation in distinct reservoirs. Today, partial melting most probably occurs in the lowermost mantle as well as at mid upper-mantle depths, which control important aspects of mantle dynamics, including some types of volcanism. Unfortunately, despite major experimental and theoretical efforts, major controversies remain about several aspects of mantle melting. For example, the liquidus of the mantle was reported (for peridotitic or chondritic-type composition) with a temperature difference of ?1000 K at high mantle depths. Also, the Fe partitioning coefficient (DFeBg/melt) between bridgmanite (Bg, the major lower mantle mineral) and a melt was reported between ?0.1 and ?0.5, for a mantle depth of ?2000 km. Until now, these uncertainties had prevented the construction of a coherent picture of the melting behavior of the deep mantle. In this article, we perform a critical review of previous works and develop a coherent, semi-quantitative, model. We first address the melting curve of Bg with the help of original experimental measurements, which yields a constraint on the volume change upon melting (?Vm). Secondly, we apply a basic thermodynamical approach to discuss the melting behavior of mineralogical assemblages made of fractions of Bg, CaSiO3-perovskite and (Mg,Fe)O-ferropericlase. Our analysis yields quantitative constraints on the SiO2-content in the pseudo-eutectic melt and the degree of partial melting (F) as a function of pressure, temperature and mantle composition; For examples, we find that F could be more than 40% at the solidus temperature, except if the presence of volatile elements induces incipient melting. We then discuss the melt buoyancy in a partial molten lower mantle as a function of pressure, F and DFeBg/melt. In the lower mantle, density inversions (i.e. sinking melts) appear to be restricted to low F values and highest mantle pressures. The coherent melting model has direct geophysical implications: (i) in the early Earth, the magma ocean crystallization could not occur for a core temperature higher than ?5400 K at the core-mantle boundary (CMB). This temperature corresponds to the melting of pure Bg at 135 GPa. For a mantle composition more realistic than pure Bg, the right CMB temperature for magma ocean crystallization could have been as low as ?4400 K. (ii) There are converging arguments for the formation of a relatively homogeneous mantle after magma ocean crystallization. In particular, we predict the bulk crystallization of a relatively large mantle fraction, when the temperature becomes lower than the pseudo-eutectic temperature. Some chemical segregation could still be possible as a result of some Bg segregation in the lowermost mantle during the first stage of the magma ocean crystallization, and due to a much later descent of very low F, Fe-enriched, melts toward the CMB. (iii) The descent of such melts could still take place today. There formation should to be related to incipient mantle melting due to the presence of volatile elements. Even though, these melts can only be denser than the mantle (at high mantle depths) if the controversial value of DFeBg/melt is indeed as low as suggested by some experimental studies. This type of melts could contribute to produce ultra-low seismic velocity anomalies in the lowermost mantle.
DS202009-1641
2020
Bolfan-Casanova, N.Moine, B.N., Bolfan-Casanova, N., Radu, I.B., Ionov, D.A., Costin, G., Korsakov, A.V., Golovin, A.V., Oleinikov, O.B., Deloule, E., Cottin, J.Y.Molecular hydrogen in minerals as a clue to interpret deltaD variations in the mantle. ( Omphacites from eclogites from Kaapvaal and Siberian cratons.)Nature Communications, doi:.org/10.1038/ s41467-020-17442 -8 11p. PdfAfrica, South Africa, Russia, Siberiawater

Abstract: Trace amounts of water dissolved in minerals affect density, viscosity and melting behaviour of the Earth’s mantle and play an important role in global tectonics, magmatism and volatile cycle. Water concentrations and the ratios of hydrogen isotopes in the mantle give insight into these processes, as well as into the origin of terrestrial water. Here we show the presence of molecular H2 in minerals (omphacites) from eclogites from the Kaapvaal and Siberian cratons. These omphacites contain both high amounts of H2 (70 to 460 wt. ppm) and OH. Furthermore, their ?D values increase with dehydration, suggesting a positive H isotope fractionation factor between minerals and H2-bearing fluid, contrary to what is expected in case of isotopic exchange between minerals and H2O-fluids. The possibility of incorporation of large quantities of H as H2 in nominally anhydrous minerals implies that the storage capacity of H in the mantle may have been underestimated, and sheds new light on H isotope variations in mantle magmas and minerals.
DS1995-0168
1995
Bolger, R.Bolger, R.Rare earth markets, magnets remain attractiveIndustrial Minerals, October pp. 27-43GlobalEconomics, Rare earths
DS201701-0021
2016
Bolhar, R.Milani. L., Bolhar, R., Cawthorn, R.G., Frei, D.In situ LA-ICP-MS and EPMA trace element characterization of Fe-Ti oxides from the phsocorite carbonatite association at Phalaborwa, South Africa.Mineralium Deposita, in press available 22p.Africa, South AfricaCarbonatite

Abstract: In situ laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and electron probe microanalysis (EPMA) are used to characterize magnetite and ilmenite of the phoscorite-carbonatite association at Phalaborwa. We trace the behavior of the compatible elements for two different generations of magnetite related to (1) a magmatic stage, with variable Ti-V content, which pre-dates the copper mineralization, and (2) a late hydrothermal, low-Ti, low-temperature event, mostly post-dating sulfide formation. Magnetite is shown to be a robust petrogenetic indicator; no influence on its chemical composition is detected from the intergrowth with the accompanying phases, including the interaction with coexisting sulfides. High spatial resolution EPMA characterize the tiny late-stage hydrothermal magnetite veins, as well as the ilmenite granular and lamellar exsolutions mostly developed in the magnetite from the phoscorite. By combining geochemical data with geothermo-oxybarometry calculations for magnetite-ilmenite pairs, we infer that the most primitive magnetite probably formed at oxygen fugacity above the nickel nickel oxide (NNO) buffer, revealing an evolutionary trend of decreasing temperature and oxygen fugacity. Geochemical similarity exists between magnetite from phoscorite and carbonatite, thus supporting a common mantle source for the phoscorite-carbonatite association.
DS201702-0227
2017
Bolhar, R.Milani, L., Bolhar, R., Cawthorn, R.G., Frei, D.In Situ LA-ICP-MS and EPMA trace element characterization of Fe-Ti oxides from the phoscorite carbonatite association at Phalaborwa, South Africa.Mineralium Deposita, in press available, 22p.Africa, South AfricaDeposit - Phalaborwa

Abstract: In situ laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and electron probe microanalysis (EPMA) are used to characterize magnetite and ilmenite of the phoscorite-carbonatite association at Phalaborwa. We trace the behavior of the compatible elements for two different generations of magnetite related to (1) a magmatic stage, with variable Ti-V content, which pre-dates the copper mineralization, and (2) a late hydrothermal, low-Ti, low-temperature event, mostly post-dating sulfide formation. Magnetite is shown to be a robust petrogenetic indicator; no influence on its chemical composition is detected from the intergrowth with the accompanying phases, including the interaction with coexisting sulfides. High spatial resolution EPMA characterize the tiny late-stage hydrothermal magnetite veins, as well as the ilmenite granular and lamellar exsolutions mostly developed in the magnetite from the phoscorite. By combining geochemical data with geothermo-oxybarometry calculations for magnetite-ilmenite pairs, we infer that the most primitive magnetite probably formed at oxygen fugacity above the nickel nickel oxide (NNO) buffer, revealing an evolutionary trend of decreasing temperature and oxygen fugacity. Geochemical similarity exists between magnetite from phoscorite and carbonatite, thus supporting a common mantle source for the phoscorite-carbonatite association.
DS201702-0228
2017
Bolhar, R.Milani, L., Bolhar, R., Frei, D., Harlov, D.E., Samuel, V.O.Light rare earth element systematics as a tool for investigating the petrogenesis of phoscorite-carbonatite associations, as exemplified by the Phalaborwa Complex, South Africa.Mineralium Deposita, in press available, 21p.Africa, South AfricaDeposit - Phalaborwa

Abstract: In-situ trace element analyses of fluorapatite, calcite, dolomite, olivine, and phlogopite have been undertaken on representative phoscorite and carbonatite rocks of the Palaeoproterozoic Phalaborwa Complex. Textural and compositional characterization reveals uniformity of fluorapatite and calcite among most of the intrusions, and seems to favor a common genetic origin for the phoscorite-carbonatite association. Representing major repositories for rare earth elements (REE), fluorapatite and calcite exhibit tightly correlated light REE (LREE) abundances, suggesting that partitioning of LREE into these rock forming minerals was principally controlled by simple igneous differentiation. However, light rare earth element distribution in apatite and calcite cannot be adequately explained by equilibrium and fractional crystallization and instead favors a complex crystallization history involving mixing of compositionally distinct magma batches, in agreement with previously reported mineral isotope variability that requires open-system behaviour.
DS201710-2215
2017
Bolhar, R.Bolhar, R., Hofman, A., Kemp, A.I.S., Whitehouse, M.J., Wind, S., Kamber, B.S.Juvenile crust formation in the Zimbabwean Craton deduced from the O-Hf isotopic record 3.8-3.1 Ga detrital zircons.Geochimica et Cosmochinica Acta, Vol. 215, pp. 432-446.Africa, Zimbabwecraton

Abstract: Hafnium and oxygen isotopic compositions measured in-situ on U-Pb dated zircon from Archaean sedimentary successions belonging to the 2.9–2.8 Ga Belingwean/Bulawayan groups and previously undated Sebakwian Group are used to characterize the crustal evolution of the Zimbabwe Craton prior to 3.0 Ga. Microstructural and compositional criteria were used to minimize effects arising from Pb loss due to metamorphic overprinting and interaction with low-temperature fluids. 207Pb/206Pb age spectra (concordance >90%) reveal prominent peaks at 3.8, 3.6, 3.5, and 3.35 Ga, corresponding to documented geological events, both globally and within the Zimbabwe Craton. Zircon ?18O values from +4 to +10‰ point to both derivation from magmas in equilibrium with mantle oxygen and the incorporation of material that had previously interacted with water in near-surface environments. In ?Hf-time space, 3.8–3.6 Ga grains define an array consistent with reworking of a mafic reservoir (176Lu/177Hf ?0.015) that separated from chondritic mantle at ?3.9 Ga. Crustal domains formed after 3.6 Ga depict a more complex evolution, involving contribution from chondritic mantle sources and, to a lesser extent, reworking of pre-existing crust. Protracted remelting was not accompanied by significant mantle depletion prior to 3.35 Ga. This implies that early crust production in the Zimbabwe Craton did not cause complementary enriched and depleted reservoirs that were tapped by later magmas, possibly because the volume of crust extracted and stabilised was too small to influence (asthenospheric) mantle isotopic evolution. Growth of continental crust through pulsed emplacement of juvenile (chondritic mantle-derived) melts, into and onto the existing cratonic nucleus, however, involved formation of complementary depleted subcontinental lithospheric mantle since the early Archaean, indicative of strongly coupled evolutionary histories of both reservoirs, with limited evidence for recycling and lateral accretion of arc-related crustal blocks until 3.35 Ga.
DS201909-2095
2019
Bolhar, R.Thakurdin, Y., Bolhar, R., Horvath, P., Wiedenbeck, M., Rocholl, A.Formation of lower to middle crust of the Wyoming craton, Montana, USA, using evidence from zircon Hf-O isotopic and trace element compositions.Chemical Geology, Vol. 525, pp. 218-244.United States, Montanacraton - Wyoming

Abstract: Coupled oxygen-hafnium isotope and trace element geochemical data were obtained using thirty eight previously dated zircon grains extracted from five mafic to intermediate crustal xenoliths of the Wyoming Craton (Montana, USA). Xenoliths include mid to lower crustal (642-817?°C and 3.5-9.4?kbar) mafic granulites and amphibolites with dominantly Mesoproterozoic (1772-1874?Ma) and minor Paleoproterozoic to Late Archean (2004-2534?Ma) 207Pb/206Pb zircon ages. Zircon oxygen isotope data indicate derivation from melts in equilibrium with a mantle source that interacted with limited supracrustal material (?18O?=?4.4-5.7‰), as well as the incorporation of supracrustal fluids or melts into mantle source regions (?18O?=?6.0-8.1‰). The small within-sample isotopic variability suggests that primary zircon did not exchange with isotopically distinct fluids or melts after initial formation. Initial zircon Hf isotopic values are highly variable across all xenoliths (?Hf?=?+3.7 to ?17.6), consistent with protolith derivation from mantle sources that incorporated evolved, unradiogenic material or were modified by subduction-related fluids. Within a single granulite xenolith, two zircon types are recognized based on CL imagery, Hf isotopes and U-Pb ages (Type I and Type II). Type I magmatic zircons show dispersed ages (ca. 1700-2534?Ma) and unradiogenic initial Hf (?Hf?=??17.6 to ?1.5, 176Hf/177Hf?=?0.281074-0.281232). The spread in ages and initial ?Hf, but narrow range in initial 176Hf/177Hf, points to variable Pb loss in response to dissolution-recrystallization of pre-existing zircon. Type II metamorphic zircon yields a younger Proterozoic population (ca. 1700-2155?Ma) with more radiogenic initial Hf relative to Type I zircon (?Hf?=??7.9 to +1.4, 176Hf/177Hf?=?0.281427-0.281578); this type represents newly grown metamorphic zircon that formed in the solid-state and incorporated Zr and Hf from pre-existing zircon and silicate matrix/metamorphic phases. REE patterns from all xenoliths are steep and positively sloping without discernible HREE depletion relative to LREE, implying zircon crystallization/recrystallization in the absence of garnet. Negative Eu anomalies signify simultaneous zircon and feldspar crystallization. Solid-state recrystallization may have lead to variations in LREE, Eu and Ce in certain xenoliths. Xenoliths containing magmatic zircon (1834?±?19?Ma) with mantle-like ?18O (4.4-5.5‰) and radiogenic initial ?Hf (?2.3 to +3.7) likely formed through crystallization of melts derived from a mantle source that incorporated minor amounts of subducted sedimentary/supracrustal material. Proterozoic (1874?±?8?Ma) xenoliths with elevated ?18O (6.0-7.0‰) and unradiogenic initial ?Hf (?8.2 to ?9.6) within magmatic zircon represent melt products of subduction-induced melting and metasomatism of the overlying mantle wedge in the vicinity of the northern GFTZ. Older (ca. 2534?Ma) xenoliths containing zircons with elevated ?18O (6.4-7.2‰) and unradiogenic ?Hf (up to ?17.6) represent crystallization of protolith magmas extracted from a mantle source metasomatized by subduction-derived fluids and melts in the Late Archean or earlier. Zircon geochronology and isotope systematics within Mesoproterozoic xenoliths support a model of ocean-closure and subsequent continental collision between the Medicine Hat Block and Wyoming Craton, resulting in the formation of subduction-related melts at ca. 1834-1874?Ma, followed by ca. 1770?Ma collision-related metamorphism thereafter.
DS202009-1657
2020
Bolhar, R.Shaikh, A.M., Tappe, S., Bussweiler, Y., Patel, S.C., Ravi, S., Bolhar, R., Viljoen, F.Clinopyroxene and garnet mantle cargo in kimberlites as probes of Dharwar craton architecture and geotherms, with implications for post-1.1 Ga lithosphere thinning events beneath southern India.Journal of Petrology, in press available, 73p. PdfIndiadeposit - Wajrakarur

Abstract: The Wajrakarur Kimberlite Field (WKF) on the Eastern Dharwar Craton in southern India hosts several occurrences of Mesoproterozoic kimberlites, lamproites, and ultramafic lamprophyres, for which mantle-derived xenoliths are rare and only poorly preserved. The general paucity of mantle cargo has hampered the investigation of the nature and evolution of the continental lithospheric mantle (CLM) beneath cratonic southern India. We present a comprehensive study of the major and trace element compositions of clinopyroxene and garnet xenocrysts recovered from heavy mineral concentrates for three ca. 1.1 Ga old WKF kimberlite pipes (P7, P9, P10), with the goal to improve our understanding of the cratonic mantle architecture and its evolution beneath southern India. The pressure-temperature conditions recorded by peridotitic clinopyroxene xenocrysts, estimated using single-pyroxene thermobarometry, suggest a relatively moderate cratonic mantle geotherm of 40?mW/m2 at 1.1 Ga. Reconstruction of the vertical distribution of clinopyroxene and garnet xenocrysts, combined with some rare mantle xenoliths data, reveals a compositionally layered CLM structure. Two main lithological horizons are identified and denoted as layer A (?80-145?km depth) and layer B (?160-190?km depth). Layer A is dominated by depleted lherzolite with subordinate amounts of pyroxenite, whereas layer B comprises mainly refertilised and Ti-metasomatised peridotite. Harzburgite occurs as a minor lithology in both layers. Eclogite stringers occur within the lower portion of layer A and at the bottom of layer B near the lithosphere-asthenosphere boundary at 1.1 Ga. Refertilisation of layer B is marked by garnet compositions with enrichment in Ca, Ti, Fe, Zr and LREE, although Y is depleted compared to garnet in layer A. Garnet trace element systematics such as Zr/Hf and Ti/Eu indicate that both kimberlitic and carbonatitic melts have interacted with and compositionally overprinted layer B. Progressive changes in the REE systematics of garnet grains with depth record an upward percolation of a continuously evolving metasomatic agent. The intervening zone between layers A and B at ?145-160?km depth is characterised by a general paucity of garnet. This ‘garnet-paucity’ zone and an overlying type II clinopyroxene-bearing zone (?115-145?km) appear to be rich in hydrous mineral assemblages of the MARID- or PIC kind. The composite horizon between ?115-160?km depth may represent the product of intensive melt/rock interaction by which former garnet was largely reacted out and new metasomatic phases such as type II clinopyroxene and phlogopite plus amphibole were introduced. By analogy with better-studied cratons, this ‘metasomatic horizon’ may be a petrological manifestation of a former mid-lithospheric discontinuity at 1.1 Ga. Importantly, the depth interval of the present-day lithosphere-asthenosphere boundary beneath Peninsular India as detected in seismic surveys coincides with this heavily overprinted metasomatic horizon, which suggests that post-1.1 Ga delamination of cratonic mantle lithosphere progressed all the way to mid-lithospheric depth. This finding implies that strongly overprinted metasomatic layers, such as the ‘garnet-paucity’ zone beneath the Dharwar craton, present structural zones of weakness that aid lithosphere detachment and foundering in response to plate tectonic stresses.
DS202103-0406
2020
Bolhar, R.Shaikh, A.M., Tappe, S., Bussweiler, Y., Patel, S.C., Ravi, S., Bolhar, R., Viljoen, F.Clinopyroxene and garnet mantle cargo in kimberlites as probes of Dharwar craton architecture and geotherms, with implications for post -1.1 Ga lithosphere thinning events beneath southern India.Journal of Petrology, Vol. 61, 9, egaa087 23p. PdfIndiadeposit - Wajrakarur

Abstract: The Wajrakarur Kimberlite Field (WKF) on the Eastern Dharwar Craton in southern India hosts several occurrences of Mesoproterozoic kimberlites, lamproites and ultramafic lamprophyres, for which mantle-derived xenoliths are rare and only poorly preserved. The general paucity of mantle cargo has hampered the investigation of the nature and evolution of the continental lithospheric mantle (CLM) beneath cratonic southern India. We present a comprehensive study of the major and trace element compositions of clinopyroxene and garnet xenocrysts recovered from heavy mineral concentrates for three c.1•1?Ga old WKF kimberlite pipes (P7, P9, P10), with the goal to improve our understanding of the cratonic mantle architecture and its evolution beneath southern India. The pressure-temperature conditions recorded by peridotitic clinopyroxene xenocrysts, estimated using single-pyroxene thermobarometry, suggest a relatively moderate cratonic mantle geotherm of 40 mW/m2 at 1•1?Ga. Reconstruction of the vertical distribution of clinopyroxene and garnet xenocrysts, combined with some rare mantle xenoliths data, reveals a compositionally layered CLM structure. Two main lithological horizons are identified and denoted as layer A (?80-145?km depth) and layer B (?160-190?km depth). Layer A is dominated by depleted lherzolite with subordinate amounts of pyroxenite, whereas layer B comprises mainly refertilised and Ti-metasomatized peridotite. Harzburgite occurs as a minor lithology in both layers. Eclogite stringers occur within the lower portion of layer A and at the bottom of layer B near the lithosphere-asthenosphere boundary at 1•1?Ga. Refertilisation of layer B is marked by garnet compositions with enrichment in Ca, Ti, Fe, Zr and LREE, although Y is depleted compared to garnet in layer A. Garnet trace element systematics such as Zr/Hf and Ti/Eu indicate that both kimberlitic and carbonatitic melts have interacted with and compositionally overprinted layer B. Progressive changes in the REE systematics of garnet grains with depth record an upward percolation of a continuously evolving metasomatic agent. The intervening zone between layers A and B at ?145-160?km depth is characterized by a general paucity of garnet. This ‘garnet-paucity’ zone and an overlying type II clinopyroxene-bearing zone (?115-145?km) appear to be rich in hydrous mineral assemblages of the MARID- or PIC kind. The composite horizon between ?115-160?km depth may represent the product of intensive melt/rock interaction by which former garnet was largely reacted out and new metasomatic phases such as type II clinopyroxene and phlogopite plus amphibole were introduced. By analogy with better-studied cratons, this ‘metasomatic horizon’ may be a petrological manifestation of a former mid-lithospheric discontinuity at 1•1?Ga. Importantly, the depth interval of the present-day lithosphere-asthenosphere boundary beneath Peninsular India as detected in seismic surveys coincides with this heavily overprinted metasomatic horizon, which suggests that post-1•1?Ga delamination of cratonic mantle lithosphere progressed all the way to mid-lithospheric depth. This finding implies that strongly overprinted metasomatic layers, such as the ‘garnet-paucity’ zone beneath the Dharwar craton, present structural zones of weakness that aid lithosphere detachment and foundering in response to plate tectonic stresses.
DS202107-1110
2021
Bolhar, R.Le Bras, L.Y., Bolhar, R., Bam, L., Guy, B.M., Bybee, G.M., Nex, P.A.M.Three dimensional tectural investigation of sulfide mineralisation from the Loolekop carbonatite-phoscorite polyphase intrusion in the Phalaborwa Igneous Complex ( South Africa), with implications for ore-forming processes.Mineralogical Magazine, 19p. Pdf doi:10.1180/mgm.2021.32Africa, South Africadeposit - Phalaborwa
DS202109-1477
2021
Bolhar, R.Le Bras, L.Y., Bolhar, R., Bam, L., Guy, B.M., Bybee, G.M., Nex, P.A.M.Three-dimensional textural investigation of sulfide mineralization from the Loolekop carbonatite-phoscorite polyphase intrusion in the Phalaborwa Igneous Complex ( South Africa), with implications for ore forming processes.Mineralogical Magazine, Vol. 85, 4, pp. 514-531.Africa, South Africadeposit - Phalaborwa

Abstract: Copper-sulfides within carbonatites and phoscorites of the Phalaborwa Igneous Complex, South Africa, have been investigated since the middle of the 20th Century. However, aspects of ore formation have remained unclear. This study examines the mechanisms involved in Cu-sulfide mineralisation by micro-focus X-ray computed tomography as applied to sulfide-rich drill core samples. Several texturally distinct assemblages of magmatic sulfides can be identified, including: (1) <500 ?m rounded bornite and chalcopyrite grains disseminated within the gangue; (2) elongated mm-scale assemblages of chalcopyrite and bornite; and (3) mm-to-cm thick chalcopyrite cumulates. Chalcopyrite veins were also observed, as well as late-stage valleriite, documenting late-stage fluid circulation within the pipe, and alteration of magmatic and hydrothermal sulfides along fractures within the gangue, respectively. The results of micro-focus X-ray computed tomography indicate that magmatic sulfides are sub-vertically aligned. Spatial variability of the sulfide assemblages suggests that textural changes within sulfide layers reflect fluctuating magma flow rate during emplacement of carbonatite-phoscorite magmas, through coalescence or breakup of sulfide liquid droplets during ascent. Modal sulfide abundances, especially for disseminated assemblages, differ from one carbonatite-phoscorite layer to another, suggesting a strong control of the mechanical sorting in the formation of Cu-sulfide textures within the Loolekop carbonatite. The alternation of carbonatite and phoscorite within the intrusion suggest that the Loolekop Pipe was emplaced through a series of successive magma pulses, which differentiated into carbonatite and phoscorite by melt immiscibility/progressive fractional crystallisation and pressure drop. Three-dimensional textural analysis represents an effective tool for the characterisation of magma flow and is useful for the understanding of magmatic processes controlling sulfide liquid-bearing phoscorite-carbonatite magmas.
DS202205-0724
2022
Bolhar, R.Tshiningayamwe, M., Bolhar, R., Nex, P.A.M., Ueckermann, H., Chang, Q.An apatite trace element and Sr-Nd isotope geochemical study of syenites and carbonatite, exemplified by the Epembe alkaline-carbonatite complex, Namibia.Lithos, 10.1016/j.lihos.2022. 106699 45p. PdfAfrica, Namibiadeposit - Epembe

Abstract: The Epembe Alkaline Carbonatite Complex (EACC) in northwestern Namibia was emplaced along a fault zone into medium- to high-grade Palaeoproterozoic basement rocks of the Epupa Metamorphic Complex (EMC), and extends over a distance of 9 km in a south-easterly direction with a width of 1 km. Nepheline syenite with minor syenite constitute the main lithologies, cross-cut by a calcite?carbonatite dyke. Apatite grains from one syenite, six nepheline syenite and five carbonatite samples were studied using cathodoluminescence (CL) imaging, trace element and Sr-Nd isotope compositions as well as U-Pb geochronology. Syenite-hosted apatite is homogenous in CL and contains the highest concentration of REE (9189-44,100 ppm) with light rare-earth element (LREE) enrichment (LaN/YbN = 4-91) relative to heavy (H) REE consistent with a magmatic origin. Negative Eu anomalies (Eu/Eu* = 0.4-0.9) in syenite apatite are attributed to the formation of apatite in an evolved mantle-derived melt associated with plagioclase fractionation. Nepheline syenite and carbonatite-hosted apatite is also commonly homogeneous in CL, while core-rim zoning and patchy textures are observed occasionally. Both texturally homogeneous and core-rim zoned apatite are enriched in LREE (LaN/YbN = 24-9) relative to HREE, consistent with a magmatic origin. Core-rim zoned apatite is characterized by rim-ward increase in REE concentrations, which can be attributed to mineral fractionation. Patchy apatite is depleted in Na, Y and REE, particularly the LREE (LaN/YbN = 4-19) relative to other nepheline syenite apatite, reflecting interaction with fluids (metasomatism). The strontium isotope composition of metasomatic apatite and magmatic apatite is indistinct suggesting a magmatic origin of the alteration fluids. No Eu anomalies (Eu/Eu* = 1) in chondrite-normalized REE patterns are observed in any apatite hosted by nepheline syenite and carbonatite. An LA-ICPMS U-Pb age of 1216 ± 11 Ma (MSWD = 4.3, 2 SE) for apatite constrains emplacement of the syenite, while magmatic nepheline syenite apatite ages are 1193 ± 14 Ma, 1197 ± 17 Ma and 1194 ± 16 Ma (MSWDs <4.0, 2 SE). The Sr and Nd isotopic composition of apatite in syenite (87Sr/86Sr(i) = 0.7035-0.7048; ?Nd(t) = +2.5 to +3.2), nepheline syenites (87Sr/86Sr(i) = 0.7031-0.7037; ?Nd(t) = +1.5 to +4.4) and carbonatite (87Sr/86Sr(i) = 0.7031-0.7033; ?Nd(t) = 0 to +3.3) overlap, pointing to a common but heterogeneous source, located in the sub-lithospheric mantle.
DS1990-1285
1990
BolinRuyuan Zhang, Hirajima, T., Banno, S., Ishiwatari, A., Jiaju Li, BolinCoesite -eclogite from Donghai area, Jiangsu Province in ChinaInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 2, extended abstract p. 923-924ChinaEclogite, Coesite
DS1984-0794
1984
BOLIN, C.Zhang ruyuan, BOLIN, C.Mineralogy of Peridotitic Inclusions, Xenocrysts in Basaltic Rocks from Silong, Qu County, Zhejiang Province.Scientia Geologica Sinica., Vol. 20, No. 1, PP. 58-71.ChinaBasaltic Rocks, Xenoliths
DS1994-1202
1994
Bolin, C.Mingguo, Z., Bolin, C., Qi, Z., QingchenThe northern Dabie shan terrain: a possible Andean type arcInternational Geology Review, Vol. 36, No. 9, Sept. pp. 867-883.ChinaTectonics, Dabie Mountains, Dabie Shan
DS1994-1203
1994
Bolin, C.Mingguo, Z., Bolin, C., Qi, Z., Qingchen, W.The northern Dabie Shan Terrain: a possible Andean type arcInternational Geology Review, Vol. 36, No. 9, Sept. pp. 867-883ChinaTerrane, Arc -Andean
DS1999-0080
1999
Bolin, C.Bolin, C., Qinchen, W., Minguo, Z.New dat a regarding hotly debated topics concerning ultra high pressure (UHP) metamorphism of the Dabie Sulu belt, east central ChinaInternational Geology Review, Vol. 41, No. 9, Sept. pp. 827-35.ChinaMetamorphism - ultra high pressure (UHP), Dabie - Sulu belt
DS1990-1284
1990
Bo-LinRu-Yuan Zhang, Cong, Bo-LinCoesite eclogite in Su-Lu region, eastern ChinaEos, Vol. 71, No. 43, October 23, p. 1708 AbstractChinaEclogite, Coesite
DS1994-1985
1994
Bolin CongZhang, R.Y., Liou, J.G., Bolin CongPetrogenesis of garnet bearing ultramafic rocks and associated eclogites In the Su-Lu ultrahigh pressure metamorphic terrane, eastern China.Journal of Metamorphic Geology, Vol. 12, No. 2, March pp. 169-186.ChinaEclogites
DS1995-2133
1995
Bolin CongZhang, R.Y., Hirajima, T., Banno, S., Bolin Cong, Liou, J.Petrology of ultrahigh pressure rocks from the southern Su Lu region, eastern China.Journal of Metamorphic Geology, Vol. 13, No. 6, Nov. pp. 659-676.ChinaMetamorphic rocks, Deposit -Su-Lu region
DS1960-1084
1969
Bolingsberg, H.J.Bryhni, I., Bolingsberg, H.J., Graf, P.R.Eclogites in Quartzo-feldspathic Gneiss of Nordfiord, West Norway.Norsk Geol. Tidsskr., Vol. 49, PP. 194-225.Norway, ScandinaviaPetrography
DS1970-0480
1972
Bolivar, S.Bolivar, S.Kimberlites of Elliott County, KentuckyMsc. Thesis, University Eastern Kentucky, 61P.Appalachia, KentuckyKimberlite, Mineralogy, Petrology
DS1975-0245
1976
Bolivar, S.Bolivar, S., Brookins, D.G.Geochemistry of the Elliott County, Kentucky, KimberlitesEos, Vol. 57, No. 10, P. 761. (abstract.).Appalachia, KentuckyGeochemistry
DS1982-0108
1982
Bolivar, S.Bolivar, S.Kimberlites: a Petrologist's Best FriendEarth Science., Vol. 35, No. 3, PP. 15-18.GlobalPetrology
DS1970-0307
1971
Bolivar, S.L.Hunt, G.H., Bolivar, S.L., Kuhnhenn, G.Kimberlite of Elliott County, KentuckyGeological Society of America (GSA), Vol. 3, No. 5, P. 323, (abstract.).United States, Appalachia, KentuckyGeology
DS1970-0538
1972
Bolivar, S.L.Hunt, G.H., Bolivar, S.L.Oxygen and Carbon Isotope Ratios of Carbonate from Kimberlites in Elliott County, Kentucky.Geological Society of America (GSA), Vol. 4, No. 2, PP. 81-82, (abstract.).United States, Appalachia, KentuckyGeochronology, Geology
DS1975-0042
1975
Bolivar, S.L.Brookins, D.G., Treves, S.B., Bolivar, S.L.Elk Creek, Nebraska, Carbonatite, Strontium GeochemistryEarth Planet. Sci. Lett., Vol. 38, PP. 79-82.GlobalKimberlite, Central States
DS1975-0043
1975
Bolivar, S.L.Brookins, D.G., Treves, S.B., Bolivar, S.L.Subsurface Carbonatite at Elk Creek, Nebraska, Strontium EvidenceEos, Vol. 56, No. 6, P. 473.GlobalKimberlite, Central States
DS1975-0246
1976
Bolivar, S.L.Bolivar, S.L., Brookins, D.G.Carbonatites Associated with Ultramafic Rocks from Mid Continental United States (us)Eos, Vol. 57, No. 4, P. 355. (abstract.).United States, Appalachia, Central StatesBlank
DS1975-0247
1976
Bolivar, S.L.Bolivar, S.L., Brookins, D.G., Lewis, R.D., Meyer, H.O.A.Geophysical Studies of the Prairie Creek Kimberlite Murfreesboro, Arkansaw.Eos, Vol. 57, No. 10, P. 762, (abstract.).United States, Gulf Coast, Arkansas, PennsylvaniaKimberlite, Geophysics, Groundmag, Gravity
DS1975-0252
1976
Bolivar, S.L.Brookins, D.G., Della valle, R.S., Bolivar, S.L.Uranium Geochemistry of Some United States KimberlitesEos, Vol. 57, No. 10, P. 762, (abstract.).United States, Gulf Coast, Arkansas, Central States, Rocky Mountains, NebraskaBlank
DS1975-0324
1976
Bolivar, S.L.Lewis, R.D., Meyer, H.O.A., Bolivar, S.L., Brookins, D.G.Mineralogy of the Diamond Bearing 'kimberlite' Murfreesboro, Arkansaw.Eos, Vol. 57, No. 10, P. 761. (abstract.).United States, Gulf Coast, Arkansas, PennsylvaniaGeochronology, Alteration, Petrography, Perovskite
DS1975-0467
1977
Bolivar, S.L.Bolivar, S.L.Geochemistry of the Prairie Creek, Arkansaw and Elliott County, Kentucky Intrusions.Ph.d. Thesis, University New Mexico, 441P.United States, Gulf Coast, Arkansas, Pennsylvania, Appalachia, Kentucky, EastGeochemistry, Lamproite
DS1975-0572
1977
Bolivar, S.L.Meyer, H.O.A., Lewis, R.D., Bolivar, S.L., Brookins, D.G.Prairie Creek Kimberlite, Mufreesboro Pike County, ArkansawInternational Kimberlite Conference SECOND, FIELD GUIDE., 14P.United States, Gulf Coast, Arkansas, PennsylvaniaPetrography, Mineral Chemistry
DS1975-0954
1979
Bolivar, S.L.Bolivar, S.L., Brookins, D.G.Geophysical and Rubidium-strontium (rb-sr) Study of the Prairie Creek Arkansaw Kimberlite.International Kimberlite Conference SECOND Proceedings, Vol. 1, PP. 289-299.United States, Gulf Coast, Arkansas, PennsylvaniaKimberlite, Geophysics, Groundmag, Geochemistry, Lamproite
DS1975-0963
1979
Bolivar, S.L.Brookins, D.G., Della valle, R.S., Bolivar, S.L.Significance of Uranium Abundance in United States Kimberlites.International Kimberlite Conference SECOND Proceedings, Vol. 1, PP. 280-288.United States, Gulf Coast, Arkansas, Appalachia, Kentucky, Central StatesUranium
DS1982-0109
1982
Bolivar, S.L.Bolivar, S.L.The Prairie Creek Kimberlite, ArkansawArkansaw GEOL. COMM. miscellaneous Publishing, No. 18, PP. 1-21.United States, Gulf Coast, Arkansas, PennsylvaniaGeology, Petrology
DS1982-0110
1982
Bolivar, S.L.Bolivar, S.L.Kimberlites; a Petrologist's Best FriendEarth Science., Vol. 35, No. 3, PP. 15-18.United States, Gulf Coast, Arkansas, Pennsylvania, Appalachia, KentuckyBlank
DS1984-0163
1984
Bolivar, S.L.Bolivar, S.L.An Overview of the Prairie Creek Intrusion, ArkansawAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) PREPRINT., No. 84-346, 12P.United States, Gulf Coast, Arkansas, PennsylvaniaLamproite, Geology, Geochemistry
DS1986-0086
1986
Bolivar, S.L.Bolivar, S.L.Overview of the Prairie Creek diamond bearing intrusion, ArkansawAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Transactions Vol, Vol. 280, Pt. A, pp. 1988-1993ArkansasBlank
DS1992-0140
1992
Bolivar, S.L.Bolivar, S.L.Lands cape geochemistry: retrospect and prospect -1990. critical comments #2Applied Geochemistry, Vol. 7, No. 1, January pp. 55-57GlobalGeomorphology, geochemistry, Environmental geochemistry -review
DS1994-0177
1994
BoliviaBoliviaThe mining perspective.Bolivia, Preprint, 13pBoliviaEconomics, Mining
DS2003-0057
2003
Bolle, O.Auwera, J.V., Bogaerts, M., Liegeois, J.P., De Maiffe, D., Wilmart, E., Bolle, O.Derivation of the 1.0 0.9 Ga ferro potassic A type granitoids of southern Norway byPrecambrian Research, Vol. 124, 2-4, pp. 107-148..NorwayBlank
DS200412-0077
2003
Bolle, O.Auwera, J.V., Bogaerts, M., Liegeois, J.P., De Maiffe, D., Wilmart, E., Bolle, O., Duchesne, J.C.Derivation of the 1.0 0.9 Ga ferro potassic A type granitoids of southern Norway by extreme differentiation from basic magmas.Precambrian Research, Vol. 124, 2-4, pp. 107-148..Europe, NorwayAlkalic
DS201212-0079
2012
Bollinger, C.Bollinger, C., Merkel, S., Raterron, P.Rheology and texture development in olivine deformed in the D-DIA at mantle PT conditions.emc2012 @ uni-frankfurt.de, 1p. AbstractMantleRheology
DS201905-1071
2019
Bollinger, C.Raterron, P., Bollinger, C., Merkel, S.Olivine intergranular plasticity at mantle pressures and temperatures.Comptes Rendus Geoscience, in press available 6p.Mantleolivine

Abstract: The ductile behavior of olivine-rich rocks is critical to constrain thermal convection in the Earth's upper mantle. Classical olivine flow laws for dislocation or diffusion creep fail to explain the fast post-seismic surface displacements observed by GPS, which requires a much weaker lithosphere than predicted by classical laws. Here we compare the plasticity of olivine aggregates deformed experimentally at mantle pressures and temperatures to that of single crystals and demonstrate that, depending on conditions of stress and temperature, strain accommodated through grain-to-grain interactions - here called intergranular strain - can be orders of magnitude larger than intracrystalline strain, which significantly weakens olivine strength. This result, extrapolated along mantle geotherms, suggests that intergranular plasticity could be dominant in most of the upper mantle. Consequently, the strength of olivine-rich aggregates in the upper mantle may be significantly lower than predicted by flow laws based on intracrystalline plasticity models.
DS1994-1401
1994
Bollinger, G.A.Powell, C.A., Bollinger, G.A., et al.A seismotectonic model for the 300 kilometer long Eastern Tennessee seismiczone.Science, Vol. 264, April 29, pp. 686-688.GlobalGeophysics -seismics
DS200712-0434
2007
Bollinger, L.Hetenyl, G., Cattin, R., Brunet, F., Bollinger, L., Vergne, J., Nabalek, J.L., Diament, M.Density distribution of the India plate beneath the Tibetan plateau: geophysical and petrological constraints on kinetics of lower crustal eclogitizationEarth and Planetary Science Letters, Vol. 264, 1-2, pp. 226-244.Asia, IndiaEclogite
DS201312-0278
2013
Bollmann, T.Frederiksen, A.W., Bollmann, T., Darbyshire, F., Van der Lee, S.Modification of continental lithosphere by tectonic processes: a tomographic image of central North America.Journal of Geophysical Research, 50060Canada, United StatesTomography - Laurentia, Superior
DS1993-1170
1993
Bolm, K.S.Orris, G.J., Page, N.J., Bolm, K.S., Gray, F.Mines, prospects and occurrences of the Venezuelan Guayana ShieldUnited States Geological Survey (USGS) Bulletin, No. B2062, pp. 29-53.Venezuela, GuyanaDiamonds
DS1930-0270
1938
Bolman, J.Bolman, J.De Edel-en-sier SteenenAmsterdam: H.j. Paris, 252P. ( DIAMONDS PP. 53-64.).GlobalKimberlite, Kimberley
DS1950-0015
1950
Bolman, J.Bolman, J.Handboek Voor EdelsteenkundeAmsterdam: H.j. Paris, 1037P. ( DIAMONDS PP. 301-405.).GlobalKimberlite, Kimberley
DS200612-0147
2006
Bologna, M.Bologna, M., Padilha, A.L., Vitorello, Fontes, S.Tectonic insight into a pericratonic subcrustal lithosphere affected by anorogenic Cretaceous magmatism in Brazil inferred from long period magnetotellurices.Earth and Planetary Science Letters, Vol. 241, 3-4, pp. 603-616.South America, BrazilTectonics
DS2000-0983
2000
Bologna, M.S.Vitorello, I., Padilha, A.L., Bologna, M.S., Padua, M.Upper mantle electrical structures beneath a stable craton and attached collisional zones.Igc 30th. Brasil, Aug. abstract only 1p.BrazilTectonics - craton, Alta Paranabia Igneous Province
DS200512-0103
2005
Bologna, M.S.Bologna, M.S., Padilha, A.L., Vitorello, I.Geoelectric crustal structure off the SW border of the Sao Francisco Craton, central Brazil, as inferred from a magnetotelluric survey.Geophysical Journal International, Vol. 162, 2, August pp.357-370.South America, BrazilGeophysics - magnetotelluric
DS201903-0499
2019
Bologna, M.S.Bologna, M.S., Dragone, G.N., Muzio, R., Peel, E., Nunez, Demarco, P., Ussami, N.Electrical structure of the lithosphere from Rio de la Plata craton to Parana Basin: amalgamation of cratonic and refertilized lithospheres in SW Gondwanaland.Tectonics, Vol. 38, 1, pp. 77-94.South America, Brazilcraton

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

Abstract: A magnetotelluric survey comprising 18 broadband stations disposed along a 450 km-long profile was carried out at the transition between the Chaco-Paraná (CPB) and the Paraná (PB) intracratonic basins in northeastern Argentina. Three-dimensional inversions of the responses show that the CPB and southern PB lithospheres are resistive (~103 ? m) down to 120 km, but with distinct crustal and upper mantle electrical properties. Also, Bouguer gravity and density anomalies are positive at CPB, whereas they are negative at PB. We associate the CPB lithosphere with the Paleoproterozoic Rio Tebicuary craton and the southern PB lithosphere with an ancient and buried piece of craton, the Southern Paraná craton. Geochemical data of mantle xenoliths from the Cenozoic alkaline/carbonatitic province within the Rio Tebicuary craton suggest a subcontinental lithospheric mantle affected by metasomatic processes, which explains its lower resistivity (reaching values as low as 300 ? m) and higher density (#Mg = 0.87). In contrast, the Southern Paraná craton is more resistive (>103 ? m) and less dense, suggesting a de-hydrated, depleted, and thicker craton. These cratons are separated by a crustal conductor (15 to 20 km depth; 1-10 ? m) that we interpret as a southward continuation of a linear anomaly (Paraná Axial Anomaly) defined in former induction studies within the PB in Brazil. Hence, we redefined the trace of this conductive lineament: instead of bending towards the Torres Syncline, it continues inside the CPB. We propose the lineament to be an Early Neoproterozoic suture zone that controlled the location of maximum subsidence in the intracratonic basins during the Paleozoic. In the Early Cretaceous, the Paraná Axial Anomaly was the site of maximum extrusion and deposition of Serra Geral basalts. This anomaly separates compositionally distinct cratonic lithospheres along its path. Melting of this heterogeneous and enriched mantle created the Paraná igneous province.
DS1987-0067
1987
Bolonin, A.V.Bolonin, A.V.Geochemistry of carbonatites of complex iron barite fluorite rare earth oredeposits.(Russian)Izv. Vyssh. Ucheb. Zaved. Geol. Razved., (Russian), No. 1, pp. 19-24RussiaCarbonatite, rare earth elements (REE).
DS200512-0104
2004
Bolonin, A.V.Bolonin, A.V., Nikiforov, A.V.Chemical composition of carbonatite minerals in Karasug deposit, Tuva.Geology of Ore Deposits, Vol. 46, 5, pp. 372-387.RussiaCarbonatite
DS200512-0781
2005
Bolonin, A.V.Nikiforov, A.V., Bolonin, A.V., Sugorakova, A.M., Popov, V.A., Lykhin, D.A.Carbonatites of central Tuva: geological structure and mineral and chemical composition.Geology of Ore Deposits, Vol. 47, 4, pp. 326-345.RussiaCarbonatite, geochemistry
DS200612-0979
2006
Bolonin, A.V.Nikiforov, A.V., Bolonin, A.V., Pokrovsky, B.G., Sugorokova, A.M., Chugaev, A.V., Lykhin, D.A.Isotope geochemistry ( O, C, S. Sr) and Rb-Sr age of carbonatites in Central Tuva.Geology of Ore Deposits, Vol. 48, 4, pp. 256-276.RussiaCarbonatite
DS200612-0980
2005
Bolonin, A.V.Nikiforov, A.V., Bolonin, A.V., Sugorakova, A.M., Popov, V.A., Lykhin, D.A.Carbonatites of central Tuva: geological structure and mineral and chemical composition.Geology of Ore Deposits, Vol. 47, 4, pp. 326-345.RussiaGeochemistry - carbonatites
DS2000-0363
2000
BolousovaGriffin, W.L., Pearson, N., Bolousova, Van AchterberghThe hafnium isotope composition of cratonic mantle: LAM MC ICPMS analysis of zircon megacrysts in kimberlites.Geochimica et Cosmochimica Acta, Vol. 64, pp. 133-47.AustraliaGeochronology
DS201905-1042
2018
Bolt, J.Hillbom, E., Bolt, J.Botswana - a modern economic history: an African diamond in the rough.Palgrave Macmillan, 235p. ISBN 9783319731438Africa, BotswanaHistory

Abstract: Together with Mauritius, Botswana is often categorized as one of two growth miracles in sub-Saharan Africa. Due to its spectacular long-run economic performance and impressive social development, it has been termed both an economic success story and a developmental state. While there is uniqueness in the Botswana experience, several aspects of the country’s opportunities and challenges are of a more general nature. Throughout its history, Botswana has been both blessed and hindered by its natural resource abundance and dependency, which have influenced growth periods, opportunities for economic diversification, strategies for sustainable economic and social development, and the distribution of incomes and opportunities. Through a political economy framework, Hillbom and Bolt provide an updated understanding of an African success story, covering the period from the mid-19th century, when the Tswana groups settled, to the present day. Understanding the interaction over time between geography and factor endowments on the one hand, and the development of economic and political institutions on the other, offers principle lessons from Botswana’s experience to other natural resource rich developing countries.
DS2003-0131
2003
Boltengagen, I.L.Boltengagen, I.L., Vlasov, V.N., Klishin, V.I.Calculation of roller-press parameters for kimberlite ore crushingJournal of Mining Science, Vol. 39, 3, pp. 260-271. www.ingenta.com/isis/searchinGlobalBlank
DS200412-0181
2003
Boltengagen, I.L.Boltengagen, I.L., Vlasov, V.N., Klishin, V.I.Calculation of roller-press parameters for kimberlite ore crushing.Journal of Mining Science, Vol. 39, 3, pp. 260-271. ingenta.com /isis/searchinTechnologyMining
DS2001-0654
2001
Bolton, E.W.Lasaga, A.C., Rye, D.M., Bolton, E.W.Calculation of fluid fluxes in Earth's CrustGeochimica et Cosmochimica Acta, Vol. 65, No. 7, pp. 1161-85.MantleGeochemistry - fluid flux models
DS201112-0022
2011
Bolton, E.W.Andrews, A.L., Wang, Z.R., Bolton, E.W., Eckert, J.O.Jr.The effect of diffusion on P-T conditions inferred by cation-exchange thermobarometry.Goldschmidt Conference 2011, abstract p.441.Africa, South AfricaKappvaal Craton, Kimberley
DS200812-0125
2008
Bolton, P.Bolton, P.Protecting the environment through public procurement: the case of South Africa.Natural Resources Forum, Vol. 32, no. 1, Feb. pp. 1-10.Africa, South AfricaSocial responsibility
DS2000-0644
2000
Bolton, T.E.McCracken, A.D., Armstrong, D.K., Bolton, T.E.Conodonts and corals in kimberlite xenoliths confirm a Devonian seaway in central Ontario and Quebec.Canadian Journal of Earth Sciences, Vol. 37, No.12, Dec. pp. 1651-63.Ontario, QuebecXenoliths, paleontology, Kirkland Lake area, Lake Timiskaming
DS2000-0645
2000
Bolton, T.E.McCraken, A.D., Bolton, T.E.Geology and paleontology of the southeast Arctic Platform and southern Baffin Island, Nunavut.Geological Survey of Canada (GSC) Bulletin., No. 557, 248p.Northwest Territories, Nunavut, Baffin IslandArctic Platform
DS1970-0633
1973
Bolviken, B.Bolviken, B., Sinding-Larsen, R.Total Error and Other Criteria in the Interpretation of Stream Sediment Data.Unknown, PP. 285-296.IndiaGeochemistry
DS1987-0290
1987
Bolze, J.Hernandez, J., De Larouziere, F.D., Bolze, J., Bordet, P.Neogene magmatism in the Western Mediterranean area, Southern Spain, North Africa- strike slip faulting and calc alkaline volcanism.(in French)Bulletin Soc. Geol. Fr.(in French), Vol. 3, No. 2, pp. 257-267GlobalLamproite, Shoshonite
DS201605-0813
2016
Bomman, F.Bomman, F., Malope, K.Investigation of the optimal vortex finder length in DMS cyclones.Diamonds Still Sparkling SAIMM 2016 Conference, Mar. 14-17, pp. 229-238.TechnologyDMS - applied
DS1989-1242
1989
Bon, E.H.Priem, H.N.A., Bon, E.H. , Verdurmen, E.A.Th., Bettencourt, J.S.rubidium-strontium (Rb-Sr) chronology of Precambrian crustal evolution in Rondonia (western margin of the Amazonian craton),BrasilJournal of South American Earth Sciences, Vol. 2, No. 2, pp. 162-170BrazilGeochronology, Amazonian craton
DS1981-0089
1981
Bonaccorsi, G.Bonaccorsi, G., Westmex Ltd., Dechow and Co. Pty Ltd.Tr 7394h and Tr 7395h de Grey River Diamond Exploration Port Hedland and Yarrie Sheets.West Australia Geological Survey Open File., No. GSWA 1202 ROLL 403 M2758, 15P.Australia, Western AustraliaProspecting
DS1994-0126
1994
Bonadiman, C.Beccaluva, L., Bonadiman, C.Metasomatic processes of upper mantle in different tectonic settings inferred from spinel perid. xenolithsInternational Symposium Upper Mantle, Aug. 14-19, 1994, pp. 111.GlobalMantle, Metasomatism
DS1998-0138
1998
Bonadiman, C.Bonadiman, C., et al.Silicate glasses in mantle xenoliths as indicators of the metasomatic agents migrating through upper mantle.Terra Nova, Abstracts, Vol. 10, suppl. 1, 4. abstractMantleXenoliths - glasses
DS2000-0168
2000
Bonadiman, C.Coltorti, M., Beccaluva, L., Bonadiman, C.Glasses in mantle xenoliths as geochemical indicators of metasomatic agentsEarth and Planetary Science Letters, Vol.183, No.1-2, Nov.30, pp.303-20.GlobalXenoliths, glasses, Metasomatism
DS2002-0187
2002
Bonadiman, C.Bonadiman, C., Coltorti, M., Upton, B.G.Metasomatised mantle peridotites from beneath the Northern Highlands Terrane, Scotland.18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.150.ScotlandPeridotites
DS200412-0117
2004
Bonadiman, C.Beccaluva, L., Bianchini, G., Bonadiman, C., Siena, F., Vaccaro, C.Coexisting anorogenic and subduction related metasomatism in mantle xenoliths from the Betic Cordillera ( southern Spain). TallaLithos, Vol. 75, 1-2, July pp. 67-87.Europe, SpainSubduction, trace element fingerprinting, petrogenetic
DS200412-0348
2004
Bonadiman, C.Coltori, M., Beccaluva, L., Bonadiman, C., Faccini, B., Ntaflos, T., Siena, F.Amphibole genesis via metasomatic reaction with clinopyroxene in mantle xenoliths from Victoria Land, Antarctica. Mt. Melbourne,Lithos, Vol. 75, 1-2, July pp. 115-139.AntarcticaMetasomatism, trace element fingerprinting, glass
DS200612-0148
2005
Bonadiman, C.Bonadiman, C., Beccaluva, L., Coltort, M., Siena, F.Kimberlite like metasomatism and garnet signature in spinel peridotite xenoliths from Sal, Cape Verde Archipelago: relics of subcontinental mantle domain.Journal of Petrology, Vol. 46, 12, pp. 2465-2493.Europe, Cape Verde IslandsMetasomatism
DS200612-0149
2006
Bonadiman, C.Bonadiman, C., Coltorti, M., Siena,F., O'Reilly, S.Y., Griffin, W.L., Pearson, N.J.Archean to Proterozoic depletion in Cape Verde lithospheric mantle.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.Europe, Cape Verde IslandsGeochemistry
DS200612-0267
2006
Bonadiman, C.Coltorti, M., Bonadiman, C.Metasomatism in intraplate and supra subduction lithospheric mantle.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 108, abstract only.MantleMetasomatism, subduction
DS200712-0196
2007
Bonadiman, C.Coltorti, M., Bonadiman, C., Faccini, B., Gregoire, M., OReilly, S.Y., Powell, W.Amphiboles from supra subduction and intraplate lithospheric mantle.Lithos, Vol. 99, 1-2, pp. 68-84.MantleSubduction
DS200712-0779
2007
Bonadiman, C.Neumann, E.R., Simon, N.S.C., Bonadiman, C., Coltorti, Delpech, GregorieExtremely refractory oceanic lithospheric mantle and its implications for geochemical mass balance.Plates, Plumes, and Paradigms, 1p. abstract p. A712.MantleHarzburgite
DS200812-0126
2008
Bonadiman, C.Bonadiman, C., Coltorti, M., Beccaluva, L., Siena, F.Mantle metasomatism vs host magma interaction: the ongoing controversy.Goldschmidt Conference 2008, Abstract p.A95.MantleMetasomatism
DS200912-0063
2009
Bonadiman, C.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
DS201603-0399
2016
Bonadiman, C.Merli, M., Bonadiman, C., Diella, V., Pavese, A.Lower mantle hydrogen partitioning between periclase and perovskite: a quantum chemical modelling.Geochimica et Cosmochimica Acta, Vol. 173, pp. 304-318.MantlePerovskite

Abstract: Partitioning of hydrogen (often referred to as H2O) between periclase (pe) and perovskite (pvk) at lower mantle conditions (24-80 GPa) was investigated using quantum mechanics, equilibrium reaction thermodynamics and by monitoring two H-incorporation models. One of these (MSWV) was based on replacements provided by Mg2+ ? 2H+ and Si4+ ? 4H+; while the other (MSWA) relied upon substitutions in 2Mg2+ ? Al3+ + H+ and Si4+ ? Al3+ + H+. H2O partitioning in these phases was considered in the light of homogeneous (Bulk Silicate Earth; pvk: 75%-pe:16% model contents) and heterogeneous (Layered Mantle; pvk:78%-pe:14% modal contents) mantle geochemical models, which were configured for lower and upper bulk water contents (BWC) at 800 and 1500 ppm, respectively. The equilibrium constant, BWCK(P,T), for the reactions controlling the H-exchange between pe and pvk exhibited an almost negligible dependence on P, whereas it was remarkably sensitive to T, BWC and the hydrogen incorporation scheme. Both MSWV and MSWA lead to BWCK(P,T) ? 1, which suggests a ubiquitous shift in the exchange reaction towards an H2O-hosting perovskite. This took place more markedly in the latter incorporation mechanism, indicating that H2O-partitioning is affected by the uptake mechanism. In general, the larger the BWC, the smaller the BWCK(P,T). Over the BWC reference range, MSWV led to BWCK(P,T)-grand average (?BWCK?) calculated along lower mantle P-T-paths of ?0.875. With regard to the MSWA mechanism, ?BWCK? was more sensitive to BWC (and LM over BSE), but its values remained within the rather narrow 0.61-0.78 range. The periclase-perovskite H2O concentration-based partition coefficient, View the MathML sourceKdH2Ope/pvk, was inferred using ?BWCK ?, assuming both hydrous and anhydrous-dominated systems. MSWV revealed a View the MathML sourceKdH2Ope/pvk-BWC linear interpolation slope which was close to 0 and View the MathML sourceKdH2Ope/pvk values of 0.36 and 0.56 (for anhydrous and hydrous system, respectively). MSWA, in turn, yielded a View the MathML sourceKdH2Ope/pvk trend with a slightly steeper negative BWC -slope, while it may also be considered nearly invariant with View the MathML sourceKdH2Ope/pvk values of 0.31-0.47 in the 800-1500 ppm interval. Combining the MSWV and MSWA results led to the supposition that View the MathML sourceKdH2Ope/pvk lies in the narrow 0.31-0.56 interval, as far as the P-T-BWC values of interest are concerned. This implies that water always prefers pvk to pe. Furthermore, it also suggests that even in lower mantle with low or very low bulk water content, periclase rarely becomes a pure anhydrous phase.
DS200912-0122
2009
Bonadiman, Piccardo.RivalentiColtorti, M., Downes, H., Gregoire, M., O'Reilly, S.Y., Beccaluva, L., Bonadiman, Piccardo.Rivalenti, SienaPetrological evolution of the European lithospheric mantle: from Archean to present day.Journal of Petrology, Vol. 50, no. 7, pp. 1181-1184.MantleMagmatism
DS201112-0628
2011
Bonafede, M.Maccaferri, F., Bonafede, M., Rivalta, E.A quantitative study of the mechanisms governing dike propogation, dike arrest and sill formation.Journal of Volcanology and Geothermal Research, Vol. 208, 1-2, Nov. pp. 39-50.TechnologyGeodynamics of dikes and sills
DS1984-0494
1984
Bonanno, A.C.Matlins, A.L., Bonanno, A.C.The Complete Guide to Buying GemsCrown Publishing, 206P.GlobalDiamonds, Kimberley
DS200712-0093
2007
Bonaparte Diamond Mines Nl.Bonaparte Diamond Mines Nl.Agreement signed for immediate diamond mining operations - off shore Namibia.Bonaparte Diamond Mines NL., Jan. 30, 2p.Africa, NamibiaNews item - press release, Diamond Fields
DS200712-0094
2007
Bonaparte Diamond Mines Nl.Bonaparte Diamond Mines Nl.Marine mining in progress - offshore Namibia.Bonaparte Diamond Mines NL., Feb. 2, 5p.Africa, NamibiaNews item - press release, Diamond Fields
DS1982-0180
1982
Bonardi, M.Duke, J.M., Bonardi, M.Chromian and radite from Reaume TownshipCan. Min., Vol. 20, pp. 49-53.OntarioWehrite, Garnet Mineralogy
DS1985-0445
1985
Bonatti, E.Michael, P.J., Bonatti, E.Peridotite Composition from the North Atlantic: Regional And Tectonic Variations and Implications for Partial Melting.Earth Planet. Sci. Letters, Vol. 73, PP. 91-104.Atlantic OceanFracture Zones, Diamond
DS1986-0087
1986
Bonatti, E.Bonatti, E., Michael, P.J.Mantle peridotites from continental rifts to ocean basinsEos, Vol. 67, No. 16, April 22, p. 393. (abstract.)GlobalMantle, Tectonics
DS1989-0141
1989
Bonatti, E.Bonatti, E., Michael, P.J.Mantle peridotites from continental rifts to ocean basins to subductionzonesEarth and Planetary Science Letters, Vol. 91, pp. 297-311GlobalMantle, Peridotite
DS1990-0220
1990
Bonatti, E.Bonatti, E.Subcontinental mantle exposed in the Atlantic ocean on St. Peter-PaulisletsNature, Vol. 345, No. 6278, June 28, pp. 800-802Atlantic oceanMantle, Petrology
DS1990-0221
1990
Bonatti, E.Bonatti, E.Not so hot spots in the oceanic mantleScience, Vol. 250, No. 4977, October 5, pp. 107-111GlobalMantle, Hotspots
DS1993-0134
1993
Bonatti, E.Bonatti, E.A cold suboceanic mantle belt at the Earth's equator #2Science, Vol. 261, July 16, pp. 315-320MantleMelting
DS1994-0178
1994
Bonatti, E.Bonatti, E.Structure and dynamics of the oceanic lithosphereInternational Symposium Upper Mantle, Aug. 14-19, 1994, pp. 165-166. extended abstractOceanLithosphere
DS1994-1571
1994
Bonatti, E.Seyler, M., Bonatti, E.Sodium and Aluminum in clinopyroxenes of subcontinental, suboceanic ridge peridotites: aclue different melting processes in mantle.Earth and Planetary Science Letters, Vol. 122, pp. 281-289.Mantle, suboceanic ridgePeridotites
DS1996-0152
1996
Bonatti, E.Bonatti, E.Long lived oceanic transform boundaries formed above mantle thermalminimaGeology, Vol. 24, No. 9, Sept. pp. 803-806GlobalTectonics
DS2001-0121
2001
Bonatti, E.Bonatti, E., Brunelli, Fabretti, Ligi, Portara, SeylerSteady state creation of crust free lithosphere at cold spots in mid-ocean ridgesGeology, Vol. 29, No. 11, Nov. pp. 979-82.MantlePeridotites, flow
DS2003-0132
2003
Bonatti, E.Bonatti, E., Ligi, M., Brunelli, D., Cipriani, A., Fabretti, P., Ferrante, V., Gasperini, L.Mantle thermal pulses below the mid Atlantic Ridge and temporal variations in theNature, No. 6939, pp. 499-505.MantleGeothermometry
DS2003-0173
2003
Bonatti, E.Brunelli, D., Cipriani, A., Ottolini, L., Peyve, A., Bonatti, E.Mantle peridotites from the Bouvet Triple Junction Region, South AtlanticTerra Nova, Vol. 15, No. 3, June pp. 194-203.Africa, South AmericaUltramafics
DS2003-0174
2003
Bonatti, E.Brunelli, D., Cipriani, A., Ottolini, L., Peyve, A., Bonatti, E.Mantle peridotites from the Bouvet Triple Junction region, South AtlanticTerra Nova, Vol. 15, 3, pp. 194-203.Atlantic OceanBlank
DS2003-0342
2003
Bonatti, E.Doglioni, C., Carminati, E., Bonatti, E.Rift symmetry and continental upliftTectonics, Vol. 22, 3, pp. 10/1029/2002TC001459GlobalTectonics, Review
DS200412-0182
2003
Bonatti, E.Bonatti, E., Ligi, M., Brunelli, D., Cipriani, A., Fabretti, P., Ferrante, V., Gasperini, L., Ottolini, L.Mantle thermal pulses below the mid Atlantic Ridge and temporal variations in the formation of oceanic lithosphere.Nature, No. 6939, pp. 499-505.MantleGeothermometry
DS200412-0229
2003
Bonatti, E.Brunelli, D., Cipriani, A., Ottolini, L., Peyve, A., Bonatti, E.Mantle peridotites from the Bouvet Triple Junction region, South Atlantic.Terra Nova, Vol. 15, 3, pp. 194-203.Atlantic OceanPeridotite
DS200412-0230
2003
Bonatti, E.Brunelli, D., Cipriani, A., Ottolini, L., Peyve, A., Bonatti, E.Mantle peridotites from the Bouvet Triple Junction Region, South Atlantic.Terra Nova, Vol. 15, no. 3, June pp. 194-203.Africa, South AmericaUltramafics
DS200412-0466
2003
Bonatti, E.Doglioni, C., Carminati, E., Bonatti, E.Rift symmetry and continental uplift.Tectonics, Vol. 22, 3, pp. 10/1029/2002 TC001459GlobalTectonics Review
DS201808-1728
2018
Bonatti, E.Brunelli, D., Cipriani, A., Bonatti, E.Thermal effects of pyroxenites on mantle melting below mid-ocean ridges.Nature Geoscience, Vol. 11, 7, pp. 520-525.Mantlepyroxenites

Abstract: After travelling in Earth’s interior for up to billions of years, recycled material once injected at subduction zones can reach a subridge melting region as pyroxenite dispersed in the host peridotitic mantle. Here we study genetically related crustal basalts and mantle peridotites sampled along an uplifted lithospheric section created at a segment of the Mid-Atlantic Ridge through a time interval of 26 million years. The arrival of low-solidus material into the melting region forces the elemental and isotopic imprint of the residual peridotites and of the basalts to diverge with time. We show that a pyroxenite-bearing source entering the subridge melting region induces undercooling of the host peridotitic mantle, due to subtraction of latent heat by melting of the low-T-solidus pyroxenite. Mantle undercooling, in turn, lowers the thermal boundary layer, leading to a deeper cessation of melting. A consequence is to decrease the total amount of extracted melt, and hence the magmatic crustal thickness. The degree of melting undergone by a homogeneous peridotitic mantle is higher than the degree of melting of the same peridotite but veined by pyroxenites. This effect, thermodynamically predicted for a marble-cake-type peridotite-pyroxenite mixed source, implies incomplete homogenization of recycled material in the convective mantle.
DS201809-2002
2018
Bonatti, E.Brunelli, D., Cipriani, A., Bonatti, E.Thermal effects of pyroxenites on mantle melting below mid-ocean ridges.Nature Geoscience, Vol. 11, July, pp. 520-525.Mantle, Oceanmelting

Abstract: After travelling in Earth’s interior for up to billions of years, recycled material once injected at subduction zones can reach a subridge melting region as pyroxenite dispersed in the host peridotitic mantle. Here we study genetically related crustal basalts and mantle peridotites sampled along an uplifted lithospheric section created at a segment of the Mid-Atlantic Ridge through a time interval of 26 million years. The arrival of low-solidus material into the melting region forces the elemental and isotopic imprint of the residual peridotites and of the basalts to diverge with time. We show that a pyroxenite-bearing source entering the subridge melting region induces undercooling of the host peridotitic mantle, due to subtraction of latent heat by melting of the low-T-solidus pyroxenite. Mantle undercooling, in turn, lowers the thermal boundary layer, leading to a deeper cessation of melting. A consequence is to decrease the total amount of extracted melt, and hence the magmatic crustal thickness. The degree of melting undergone by a homogeneous peridotitic mantle is higher than the degree of melting of the same peridotite but veined by pyroxenites. This effect, thermodynamically predicted for a marble-cake-type peridotite–pyroxenite mixed source, implies incomplete homogenization of recycled material in the convective mantle.
DS1992-0141
1992
Bonavia, F.F.Bonavia, F.F., Chorowicz, J.Northward extension of the Pan-African of northeast Africa guided by are entrant zone of the Tanzania cratonGeology, Vol. 20, No. 11, November pp. 1023-1026TanzaniaTectonics, Craton
DS1999-0067
1999
Bonazzi, P.Bindi, L., Bonazzi, P.Crystal chemistry of natural melilites: superstructure and incommensurate modulation in hardystonite.Plinus, No. 22, p. 52-3. abstractGlobalMineralogy - melilites
DS201707-1346
2017
Bonazzi, P.Lepore, G.O., Bindi, L., Pedrazzi, G., Conticelli, S., Bonazzi, P.Structural and chemical variations in phlogopite from lamproitic rocks of the central Mediterranean region.Lithos, in press available, 69p.Europe, Italylamproite

Abstract: Micas from mafic ultrapotassic rocks with lamproitic affinity from several localities of the Central Mediterranean region were studied through single-crystal X-ray diffraction (SC-XRD), electron microprobe analysis (EMPA) and Secondary Ion Mass Spectrometry (SIMS); Mössbauer Spectroscopy (MöS), when feasible, was also applied to minimise the number of unknown variables and uncertainties. Lamproitic samples analysed cover the most important Central Mediterranean type localities, from Plan d'Albard (Western Alps) to Sisco (Corsica), Montecatini Val di Cecina and Orciatico (Tuscany, Italy) and Torre Alfina (Northern Latium, Italy). The studied crystals show distinctive chemical and structural features; all of them belong to the phlogopite-annite join and crystallise in the 1 M polytype, except for micas from Torre Alfina, where both 1 M and 2 M1 polytypes were found. Studied micas have variable but generally high F and Ti contents, with Mg/(Mg + Fe) ranging from ~ 0.5 to ~ 0.9; 2M1 crystals from Torre Alfina radically differ in chemical composition, showing high contents of Ti and Fe as well as of Al in both tetrahedra and octahedra, leading to distinctive structural distortions, especially in tetrahedral sites. SIMS data indicate that studied micas are generally dehydrogenated with OH contents ranging from ~ 0.2 apfu (atoms per formula unit) for Orciatico and Torre Alfina to ~ 1.4 for Plan d'Albard crystals; this feature is also testified by the length of the c parameter, which decreases with the loss of hydrogen and/or the increase of the F ? OH substitution. Chemical and structural data suggest that the entry of high charge octahedral cations is mainly balanced by an oxy mechanism and, to a lesser extent, by a M3 +,4 +-Tschermak substitution. Our data confirm that Ti preferentially partitions into the M2 site and that different Ti and F contents, as well as different K/Al values, are both dependant upon fH2O and the composition of magma rather than controlled by P and T crystallisation conditions. The obtained data help to discriminate among lamproite-like rocks formed within a complex geodynamic framework but still related to a destructive tectonic margin and evidence different trends for micas from the youngest Torre Alfina (Northern Latium) lamproites, referred to the Apennine orogeny and those of the older lamproites from Orciatico, Montecatini Val di Cecina (Tuscany), Western Alps, and Corsica, the latter referred to the Alpine orogeny. Phlogopite crystals from the older lamproites fall within the compositional and structural field of worldwide phlogopites from both within-plate and subduction-related settings. Phlogopite from the Plio-Pleistocene lamproite-like occurrence in Tuscany and Northern Latium, despite crystals with low Mg# of the Torre Alfina rock plot well within the general field of the other crystals in less evolved samples, follows a different evolution trend similar to that of shoshonites from Tuscany and Northern Latium. On this basis, we argue that the observed differences are inherited by slight differences in the magma compositions that are related with different genetic and evolution pathways.
DS2000-0553
2000
Boncio, P.Lavecchia, G., Boncio, P.Tectonic setting of the carbonatite melitilite association of ItalyMineralogical Magazine, Vol. 64, No. 4, Aug. 1, pp. 583-92.ItalyMelilite
DS2000-0568
2000
Bonco, P.Levecchia, G., Bonco, P.Tectonic setting of the carbonatite melilitite association of ItalyMineralogical Magazine, Vol. 64, No. 4, Aug. pp. 583-92.ItalyCarbonatite, Tectonics
DS1992-0142
1992
Bond, A.R.Bond, A.R., Levine, R.M., Austin, G.I.Russian diamond industry in state of fluxPost Soviet Geology, Vol. 33, No. 10, December pp. 635-644Russia, Commonwealth of Independent States (CIS)Markets, Diamonds
DS200812-0170
2008
Bond, C.E.Butler, R.W.H., Bond, C.E., Shipton, Z.K., Jones, R.R., Casey, M.Fabric anisotropy controls faulting in the continental crust.Journal Geological Society of London, Vol. 165, 2, pp. 449-452.MantleAnisotropy
DS201912-2784
2019
Bond, C.E.Gilfillan, S.M.V., Gyore, D., Flude, S., Johnson, G., Bond, C.E., Hicks, N., Lister, R., Jones, D.G., Kremer, Y., Hazeldine, R.S., Stuart, F.M.Noble gases confirm plume related mantle degassing beneath southern Africa.Nature Communications, Vol. 10, 1, 10.1038/s41467-019-1244-6Africa, South Africaplumes

Abstract: Southern Africa is characterised by unusually elevated topography and abnormal heat flow. This can be explained by thermal perturbation of the mantle, but the origin of this is unclear. Geophysics has not detected a thermal anomaly in the upper mantle and there is no geochemical evidence of an asthenosphere mantle contribution to the Cenozoic volcanic record of the region. Here we show that natural CO2 seeps along the Ntlakwe-Bongwan fault within KwaZulu-Natal, South Africa, have C-He isotope systematics that support an origin from degassing mantle melts. Neon isotopes indicate that the melts originate from a deep mantle source that is similar to the mantle plume beneath Réunion, rather than the convecting upper mantle or sub-continental lithosphere. This confirms the existence of the Quathlamba mantle plume and importantly provides the first evidence in support of upwelling deep mantle beneath Southern Africa, helping to explain the regions elevation and abnormal heat flow.
DS1984-0164
1984
Bond, G.C.Bond, G.C., Nickeson, P.A., Kominz, M.A.Breakup of a supercontinent between 625 Ma and 555 Ma: new evidence And implications for continent histories.Earth and Planetary Science Letters, Vol. 70, pp. 325-45.North America, ArgentinaTectonics, Rifting
DS1988-0069
1988
Bond, G.C.Bond, G.C., Kominz, M.A.Evolution of thought on passive continental margins from The origin of geosynclinal theory ~ 1860 to the presentGeological Society of America (GSA) Bulletin, Vol. 100, No. 12, December pp. 1909-1933GlobalGeosyncline, Review-continental margins
DS1991-0914
1991
Bond, G.C.Kominz, M.A., Bond, G.C.Unusually large subsidence and sea-level events during middle Paleozoictime: new evidence supporting mantle convection models for supercontinentassemblyGeology, Vol. 19, No. 1, pp. 56-60North AmericaMantle, Craton
DS1930-0016
1930
Bond, G.W.Bond, G.W.Lesser Known Base Minerals in South AfricaMin. Ind. Magazine (johannesburg), Vol. 11, Dec. 24TH. PP. 340-343.South AfricaMining Economics
DS1960-0326
1963
Bond, G.W.Bond, G.W.Gemstones and Semi-precious Stones in Southern AfricaMining Engineering Journal of South Africa, Vol. 74, No. 3683, PP. 757-758.South AfricaMineral Occurrences, Resources
DS1990-0773
1990
Bond, K.R.Johnson, P.R., Zietz, I., Bond, K.R.U.S. West coast revisited: an aeromagnetic perspectiveGeology, Vol. 18, No. 4, April pp. 323-335California, CordilleraGeophysics -magnetics, Lineaments
DS1996-0153
1996
Bond, S.A.Bond, S.A., Sharry, P.V., Bond, W.F., Onley, P.G.Decision analysis in the mining industryAusIMM Conference Perth March 24-28, pp. 325-340AustraliaEconomics, geostatistics, discoveries, Decision analysis
DS1996-0153
1996
Bond, W.F.Bond, S.A., Sharry, P.V., Bond, W.F., Onley, P.G.Decision analysis in the mining industryAusIMM Conference Perth March 24-28, pp. 325-340AustraliaEconomics, geostatistics, discoveries, Decision analysis
DS1983-0139
1983
Bond Corporation Holdings LtdBond Corporation Holdings LtdBond Sells Argyle Diamond Stake for $ A42mCity of London, Financial Public Relations Release., Oct. 10TH. 1P.Australia, Western Australia, ArgyleInvestment, Mineral Economics
DS1992-0143
1992
Bondam, J.Bondam, J.The Gronnedal-Ika alkaline complex in South Greenland. Review of geoscientific dat a relevant to explorationGreenland Open File series, No. 92/2, 28p. 9 figs. 11 tables 1 map. 55 KronerGreenlandAlkaline rocks, Carbonatite, apatite, geophysics, geochemistry
DS1995-0169
1995
Bondarenko, A.T.Bondarenko, A.T., Boris, E.I., Stogova, V.A.Lateral variation of electrical properties of kimberlite hosting sedimentary rocks of western YakutiaRussian Geology and Geophysics, Vol. 36, No. 3, pp. 113-119.Russia, YakutiaGeophysics, Deposit -Malo-Botuoba
DS201909-2027
2019
Bondarenko, G.V.Butvina, V.G., Vorobey, S.S., Safonov, O.G., Varlamov, D.A., Bondarenko, G.V., Shapovalov, Yu.B.Experimental study of the formation of chromium-bearing priderite and yimengite as products of modal mantle metasomatism.Doklady Earth Sciences, Vol. 486, 2, pp. 711-715.Mantlemetasomatism

Abstract: The results of experiments on the synthesis of exotic titanates (priderite and yimengite) simulating metasomatic conditions of alteration of the mantle minerals (chromite and ilmenite) are reported. Ba-free Cr-bearing priderite was synthesized for the first time. Experiments showed the possibility of crystallization of this mineral as a product of the reaction of high-Cr spinel and rutile with hydrous-carbonate fluid (melt) under the conditions of the upper mantle. In particular, the experimental data obtained provide an interpretation of the relationships between K?Cr priderite and carbonate-silicate inclusions in chromites from garnet peridotite of the Bohemian massif. Experimental study of the reaction of chromite and ilmenite with potassic hydrous-carbonate fluid (melt) shows the presence of both titanate phases (priderite and yimengite), the mineral indicators of mantle metasomatism. This provides direct evidence for the formation of yimengite and K?Cr priderite, as well as other titanates, due to mantle metasomatism of the upper mantle peridotite under the conditions of the highest activities of potassium.
DS1994-0967
1994
Bondarenko, G.Ye.Kuznetsov, N.B., Bondarenko, G.Ye., Savostin, L.A.First find of alpine type ultramafics in central KamchatkaDoklady Academy of Sciences Acad. Science, Vol. 322, pp. 39-43.Russia, KamchatkaUltramafics, Peridotite
DS202103-0400
2021
Bondarenko, M.Popov, M., Bondarenko, M., Kulnitskiy, B., Zholudev, S., Blank, V., Terentyev, S.Impulse laser cutting of diamond accompanied by phase transitions to fullerene -type onion.Diamond & Related Materials, Vol. 113, 108281, 6p. PdfGlobalraman spectroscopy
DS1981-0090
1981
Bondarenko, S.I.Bondarenko, S.I.Possibility of Investigation of Kimberlite Pipes by Superconductive Geomagneic Variation Measuring Stations.National Technical Information Service N84-17724/5, 12P.RussiaGeophysics, Kimberlite
DS1981-0091
1981
Bondarenko, S.I.Bondarenko, S.I., Verkin, B.I., et al.Study of Kimberlite Pipes by Superconductor Magnetic Variation Stations.Soviet Geology And Geophysics, Vol. 22, No. 11, PP. 90-94.RussiaGeophysics, Groundmag, Emf, Kimberlite
DS200612-0421
2006
Bondarev, O.Galimov, E., Kudin, A., Skorobogatskii, V., Plotnichenko, V., Bondarev, O., Zarubin, B., Strazdovskii, V., Aronin, A., Fisenko, A., Bykov, I., Barinov, A.Experimental corrobation of the synthesis of diamond in the cavitation process.Doklady Physical Chemistry, Vol. 49, 3, pp. 150-153.TechnologyDiamond synthesis
DS201609-1728
2010
Bondi, E.Lane, G.R., Milovanovic, B., Bondi, E.Economic modelling and its application in strategic planning.The 4th Colloquium on Diamonds - source to use held Gabarone March 1-3, 2010, 14p.GlobalEconomics - strategic planning

Abstract: Mining executives often have a difficult task detennining what the strategic objective of the business should be as this can be impacted by the prevailing market conditions. In addition, they have no mechanism to quantitatively 'test' the impact of this strategic decision on the business and understand the underlying dynamics. During the commodities bull run of 2003 to 2008 the strategic objective may have been to grow the long term value of the business (NPV) tluough increased tonnage, acquisition and finding new reserves, which all came with an increasing fixed cost base. Now with the financial crisis upon us and the collapse of commodity prices and demand, executives have adjusted their strategies as 'cash is king' and short-tenn cash flow, in some instances at the expense of long terms value, is the order of the day. For many mining companies, mine closures, reductions in production and cost cutting exercisers are now the focus. In many instances, management do not have an ability to rapidly test different strategic alternatives to 'test' the impact on value, unit costs, reserves and profitability at the operational level and optimise the underlying trade-off variables. Economic modelling of the complete business value chain is a means of linking the operational 'reality ' and strategic choices, so that the full impact can be assessed. This paper describes some of the challenges facing mining executives and how economic modelling can be applied to make decision making more rigorous.
DS201610-1850
2016
Bondinier, J-L.Chetoumani, K., Bondinier, J-L., Garrido, C.J., Marchesi, C., Amri, I., Targusiti, K.Spatial variability of pyroxenite layers in the Beni Bousera orogenic peridotite ( Morocco) and implications for their origin.Comptes Rendus Geoscience, in press available 11p.Africa, MoroccoPeridotite

Abstract: The Beni Bousera peridotite contains a diversity of pyroxenite layers. Several studies have postulated that at least some of them represent elongated strips of oceanic lithosphere recycled in the convective mantle. Some pyroxenites were, however, ascribed to igneous crystal segregation or melt-rock reactions. To further constrain the origin of these rocks, we collected 171 samples throughout the massif and examined their variability in relation with the tectono-metamorphic domains. A major finding is that all facies showing clear evidence for a crustal origin are concentrated in a narrow corridor of mylonitized peridotites, along the contact with granulitic country rocks. These peculiar facies were most likely incorporated at the mantle-crust boundary during the orogenic events that culminated in the peridotite exhumation. The other pyroxenites derive from a distinct protolith that was ubiquitous in the massif before its exhumation. They were deeply modified by partial melting and melt-rock reactions associated with lithospheric thinning.
DS1994-0179
1994
Bondy, M.Bondy, M.Trends in international mining taxationCanadian Institute 1994 Canadian Mining Symposium, Preprint, 40pGlobalEconomics, Mining industry -taxation
DS1995-0044
1995
Bone, R.M.Anderson, R.B., Bone, R.M.First Nations economic development: a contingency perspectiveCanadian Geographer, Vol. 39, No. 2, pp. 120-130CanadaLegal, Aborigines
DS1995-0045
1995
Bone, R.M.Anderson. R.B., Bone, R.M.First Nations economic development: a contingency perspectiveCanadian Geographer, Vol. 39, No. 2, pp. 120-130.CanadaNative rights, Overview- First Nations
DS201601-0006
2015
Boneh, Y.Boneh, Y., Morales, L.F.G., Kaminiski, E., Skemer, P.Modeling olivine CPO evolution with complex deformation histories: implications for the interpretation of seismic anisotropy in the mantle.Geochemistry, Geophysics, Geosystems: G3, Vol. 16, 10, pp. 3436-3455.MantleGeophysics - seismics

Abstract: Relating seismic anisotropy to mantle flow requires detailed understanding of the development and evolution of olivine crystallographic preferred orientation (CPO). Recent experimental and field studies have shown that olivine CPO evolution depends strongly on the integrated deformation history, which may lead to differences in how the corresponding seismic anisotropy should be interpreted. In this study, two widely used numerical models for CPO evolution—D-Rex and VPSC—are evaluated to further examine the effect of deformation history on olivine texture and seismic anisotropy. Building on previous experimental work, models are initiated with several different CPOs to simulate unique deformation histories. Significantly, models initiated with a preexisting CPO evolve differently than the CPOs generated without preexisting texture. Moreover, the CPO in each model evolves differently as a function of strain. Numerical simulations are compared to laboratory experiments by Boneh and Skemer (2014). In general, the D-Rex and VPSC models are able to reproduce the experimentally observed CPOs, although the models significantly over-estimate the strength of the CPO and in some instances produce different CPO from what is observed experimentally. Based on comparison with experiments, recommended parameters for D-Rex are: M*?=?10, ?*?=?5, and ??=?0.3, and for VPSC: ??=?10-100. Numerical modeling confirms that CPO evolution in olivine is highly sensitive to the details of the initial CPO, even at strains greater than 2. These observations imply that there is a long transient interval of CPO realignment which must be considered carefully in the modeling or interpretation of seismic anisotropy in complex tectonic settings.
DS202110-1602
2021
Boneh, Y.Boneh, Y., Chin, E.J., Hirth, G.Microstructural analysis of a mylonitic mantle xenolith sheared laboratory-like strain rates from the edge of the Wyoming craton.Minerals MDPI, Vol. 11, 995, 18p. PdfUnited States, Montana, Wyoming, Utah, Canada, Alberta, Saskatchewancraton

Abstract: Combined observations from natural and experimental deformation microstructures are often used to constrain the rheological properties of the upper mantle. However, relating natural and experimental deformation processes typically requires orders of magnitude extrapolation in strain rate due to vastly different time scales between nature and the lab. We examined a sheared peridotite xenolith that was deformed under strain rates comparable to laboratory shearing time scales. Microstructure analysis using an optical microscope and electron backscatter diffraction (EBSD) was done to characterize the bulk crystallographic preferred orientation (CPO), intragrain misorientations, subgrain boundaries, and spatial distribution of grains. We found that the microstructure varied between monophase (olivine) and multiphase (i.e., olivine, pyroxene, and garnet) bands. Olivine grains in the monophase bands had stronger CPO, larger grain size, and higher internal misorientations compared with olivine grains in the multiphase bands. The bulk olivine CPO suggests a dominant (010)[100] and secondary activated (001)[100] that are consistent with the experimentally observed transition of the A to E-types. The bulk CPO and intragrain misorientations of olivine and orthopyroxene suggest that a coarser-grained initial fabric was deformed by dislocation creep coeval with the reduction of grain size due to dynamic recrystallization. Comparing the deformation mechanisms inferred from the microstructure with experimental flow laws indicates that the reduction of grain size in orthopyroxene promotes activation of diffusion creep and suggests a high activation volume for wet orthopyroxene dislocation creep.
DS202111-1763
2021
Boneh, Y.Chin, E.J., Chilson-Parks, B., Boneh, Y., Hirth, G., Saal, A.E., Hearn, B.C., Hauri, E.H.The peridotite deformation cycle in cratons and the deep impact of subduction.Tectonophysics, Vol. 817, 229029, 22p. PdfUnited States, Wyomingdeposit - Homestead, Williams

Abstract: Xenoliths play a crucial role in interpretation of mantle deformation and geochemistry. The classic work of Mercier and Nicolas (1975) introduced the concept of the peridotite deformation cycle, which connected observed microstructures to a physical sequence of deformation. We revisit Mercier and Nicolas' original concept, bringing in new constraints using large area EBSD maps and associated microstructural datasets, analysis of water contents in nominally anhydrous minerals, and trace element chemistry of pyroxenes and garnets. We apply these techniques to a well-characterized suite of peridotite xenoliths from the Eocene-age Homestead and Williams kimberlites in the northwestern Wyoming Craton. Pyroxene water content and trace element mineral chemistries reveal ubiquitous hydrous metasomatism beneath the craton, most likely linked to the Cenozoic Laramide Orogeny. Homestead xenoliths primarily exhibit coarse protogranular and equigranular textures, B-type olivine fabrics, and generally elevated mineral water contents compared to Williams. Xenoliths from Williams are strongly deformed, with porphyroclastic and transitional textures containing annealed olivine tablets, mostly A-type olivine fabrics, and generally lower mineral water contents. As a whole, mantle from Homestead to Williams reflects a cratonic scale deformation cycle that likely initiated in Laramide times and lasted until the end of orogeny in the Eocene. At Williams, evidence for a rapid deformation “sub-cycle” within the main deformation cycle is preserved in the tablet-bearing xenoliths, corresponding to the enigmatic “transitional” texture of Mercier and Nicolas (1975). Our results suggest that this texture reflects interruption of the main deformation cycle by processes possibly related to a rapidly forming lithospheric instability and generation of the kimberlite magma - offering a new interpretation of this ambiguous peridotite texture. Collectively, our results incorporate typically disparate geochemical and textural datasets on xenoliths to shed new insights into how metasomatism, volatiles, and deformation are connected in the deep cratonic lithosphere.
DS201502-0044
2015
Bonetto, S.Bonetto, S., Facello, A., Ferrero, A-M., Umili, G.A tool for semi-automatic linear feature detection based on DTM.Computers & Geosciences, Vol. 75, pp. 1-12.TechnologyNot specific to diamonds
DS2002-0188
2002
Bonev, I.K.Bonev, I.K., Kerestedjiian, T., Atanassova. R., AndrewMorphogenesis and composition of native gold in the Chelopech volcanic hosted au Cu epithermal deposit.Mineralium Deposita, Vol.BulgariaCopper, gold, Srednogorie zone, Deposit - Chelcopech
DS1995-1714
1995
Bongina, M.M.Sharkov, E.V., Bongina, M.M., Mekhonoshin, A.S.Tectonic blocks of the Precambrian lower crust and upper mantle, southern Sayan Mountains, East Siberia.International Geology Review, Vol. 37, No. 1, Jan. pp. 81-91.Russia, SiberiaTectonics, Sayan Mountains
DS201808-1789
2018
Bongiolo, E.M.Simon, M., Bongiolo, E.M., Avila, C.A., Oliveira, E.P., Texeira, W., Stohler, R.C., Soares de Oliveira, F.V.Neoarchean reworking of TTG like crust in the southern most portion of the Sao Francisco craton: U-Pb zircon dating and geochemical evidence from the Sao Tiago batholith.Precambrian Research, Vol. 314, pp. 353-376.South America, Brazilcraton

Abstract: Field, petrographic and geochemical data combined with in situ zircon U-Pb LA-ICP-MS ages are documented for the São Tiago Batholith (southernmost portion of the São Francisco Craton) to understand its origin and magmatic evolution. The geologic relations indicate that the batholith is composed of granitic to granodioritic orthogneisses (L2) with tonalitic xenoliths (L1) intruded by pegmatite (L3) and metagranite (L4). L1 consists of two facies of tonalitic orthogneiss, one biotite-rich, and the other biotite-poor. The geochemical evidence, including high K2O with mantle-like chemical signature, suggests that the Bt-rich tonalitic gneiss (2816?±?30?Ma) was derived from contamination of mafic magmas by crustal-derived components. The Bt-poor tonalitic gneiss, of TTG affinity, was generated by partial melting of LILE-enriched mafic rocks, possibly from oceanic plateus in a subduction environment. L2 includes two distinct types of rocks: (i) granodioritic orthogneiss, chemically ranging from medium-pressure TTGs to potassic granitoids originated via partial melting of previous TTG crust, including L1 Bt-poor; and (ii) granitic gneiss (2664?±?4?Ma), geochemically similar to crustal-derived granites, produced by melting of the L1 Bt-rich tonalitic gneiss or mixed TTG/metasedimentary sources. L3 pegmatite (2657?±?23?Ma) results from melting of L2, whereas L4 metagranite (dikes and stocks) shows petrogenesis similar to that of the L2 granitic gneiss. Related orthogneisses occur near the São Tiago Batholith: (i) a hornblende-bearing tonalitic gneiss, and (ii) a hybrid hornblende-bearing granitic gneiss (2614?±?13?Ma), whose genesis is linked with interaction of sanukitoid and felsic potassic melts, representing the last Archean magmatic pulse of the region. The Minas strata along the Jeceaba-Bom Sucesso lineament near our study region encircle the São Tiago Archean crust, representing an irregular paleo-coastline or a micro-terrane amalgamation with the São Francisco Proto-craton, with possible subsequent dome-and-keel deformational processes. Our petrological and geochronological data reevaluate nebulous concepts in the literature about the SFC, revealing (i) a chemically and compositionally diverse crustal segment generated at the Late Archean in diverse geodynamic scenarios, and (ii) a more complex lineament than previously thought in terms of the paleogeography of the southern São Francisco Craton.
DS201911-2516
2019
Bongiolo, E.M.Dantas de Araujo, A.J., Bongiolo, E.M., Avila, C.A.The southern Sao Francisco craton puzzle: insights from aerogeophysical and geological data.Journal of South American Earth Sciences, Vol. 94, 102203 14p. PdfSouth America, Brazilgeophysics - magnetics

Abstract: Accretionary orogens are considered as the result of the major crust production process, and terranes are accreted material representing distinctive assemblages regarding age and evolution. Scientific advances in the last years show that the southernmost São Francisco Craton includes Archean, Paleoproterozoic and Neoproterozoic areas. We used aerogeophysical data and field geology to understand the extension of individual pieces of this tectonic puzzle. We described five magnetometric lineaments. A-, B- and C-lineaments are related to dyke swarms of different ages. D- and E-lineaments represent regional-scale tectonic structures. In a tectonic perspective, we have identified the following terranes: (i) the Archean São Tiago crust (2.67?Ga), which is part of the São Francisco proto-craton; two Siderian juvenile arcs, represented by the (ii) Cassiterita (2.47?Ga) and the (iii) Resende Costa/Lagoa Dourada (2.36-2.35?Ga) orthogneisses; and two Rhyacian arcs, the (iv) juvenile Serrinha (2.22-2.20?Ga) and the continental Ritápolis (2.19-2.10?Ga) arcs. Tectonic terranes and five magnetic subdomains were identified on the basis of (i) association of shear zones/faults with quartz veins in the field; (ii) low- and high-intensity magnetic anomalies; (iii) sharp contrast in Euler solution intensities; and (iv) high-contrast in radioelement contents in the gammaspectrometric maps. Processing of aerogeophysical data permitted us to propose a new scenario on the evolution of the southern São Francisco Craton, and in particular of the Mineiro belt. The integration between aerogeophysical, new and compiled geologic information, provides a robust model for the understanding of individual tectonic pieces of the studied area.
DS1993-0566
1993
Bonhamcaon, G.F.Graham, D.F., Bonhamcaon, G.F.Airborne radiometric dat a - a new tool for reconnaissance geological mapping using a GISPhotogrammetry E.R., Vol. 59, No. 8, August, pp. 1243-1249GlobalGIS, Geophysics -radiometric data
DS1990-1473
1990
Bonham-Carter, G.F.Tooker, M., Schewchenko, N., Bonham-Carter, G.F., Renze, A.N.Plotter- a fortran program using UNIRAS for plotting SPANS and EASI/PACEimagesGeological Survey of Canada Open File, No. 2255, 43p. Report and 1 diskette $ 23.00GlobalComputer, Program -PLOTTER.
DS1993-0559
1993
Bonham-Carter, G.F.Goodacre, A.K., Bonham-Carter, G.F., Agterberg, F.P., Wrightm D.F.A statistical analysis of the spatial association of seismicity with drainage patterns and magnetic anomalies in western QuebecTectonophysics, Vol. 217, No. 3-4, January 30, pp. 285-306QuebecGeomorphology, Geophysics -seismics
DS1994-0043
1994
Bonham-Carter, G.F.An, P., Moon, W.M., Bonham-Carter, G.F.An object-oriented knowledge representation structure for exploration dataintegrationNonrenewable Resources, Vol. 3, No. 2, Summer, pp. 132-145GlobalBase metals, sulphides, Geostatistics -database
DS1994-0044
1994
Bonham-Carter, G.F.An, P., Moon, W.M., Bonham-Carter, G.F.Uncertainty management in integration of exploration dat a using the BeliefFunctionNonrenewable Resources, Vol. 3, No. 1, Spring, pp. 60-71GlobalEBF function, Geostatistics
DS1994-0180
1994
Bonham-Carter, G.F.Bonham-Carter, G.F.Geographic information systems for geoscientists: modelling with GISPergamon, 350p. approx. $ 50.00GlobalBook -table of contents, GIS systems
DS1994-0181
1994
Bonham-Carter, G.F.Bonham-Carter, G.F.Geographic information systems for geoscientists...modelling with GISPergamon, 415p. approx. $ 50.00GlobalBook -ad, Geographic information systems
DS1996-0154
1996
Bonham-Carter, G.F.Bonham-Carter, G.F.GIS for mineral exploration in the mid-90'sProspectors and Developers Association of Canada (PDAC) Short Course, pp. 77-86CanadaGIS, Short course -Exploration technology
DS2003-0557
2003
Bonham-Carter, G.F.Harris, J.R., Bonham-Carter, G.F.A method of detecting glacial dispersal trains in till geochemical dataGeochemistry, Vol. 3, 2, pp. 133-156.OntarioGeochemistry - Kapuskasing structure, Not specific to diamonds
DS200412-0795
2003
Bonham-Carter, G.F.Harris, J.R., Bonham-Carter, G.F.A method of detecting glacial dispersal trains in till geochemical data.Geochemistry, Vol. 3, 2, pp. 133-156.Canada, OntarioGeochemistry - Kapuskasing structure Not specific to diamonds
DS200412-0797
2004
Bonham-Carter, G.F.Harris, J.R., Vijoen, D., Bonham-Carter, G.F., Brown, N.Dispersal train identification algorthim (DTIA).Geological Survey of Canada, Open File 4672, 1 CD $ 20.00TechnologyComputer - geochemistry .. not specific to diamonds
DS201412-0334
2014
Bonham-Carter, G.F.Hall, G.E.M., Bonham-Carter, G.F., Buchar, A.Evaluation of portable X-ray fluorescence (pXRF) in exploration and mining: Phase 1, control reference materials.Geochemistry: Exploration, Environment, Analysis, Vol. 14, 2, pp. 99-123.TechnologypXRF
DS1960-0219
1962
Bonhomme, M.Bonhomme, M.Contribution a l'etude Geochronologique de la Platforme de L'ouest Africain.Clermont University Fac. Sci. Annales Geol. Et Mineral., No. 5, PT. 5, 62P.West Africa, GuineaTectonics, Structure
DS1989-1218
1989
Bonhomme, M.G.Pillet, D., Bonhomme, M.G., Duthou, ChenevoyChronologie Rb-Sr et K-Ar du granite peralcalin du Lac Brisson, Labradorcentral.Canadian Journal of Earth Sciences, Vol. 26, pp. 328-32.Labrador, QuebecGeochronology
DS1998-0718
1998
Bonhomme, M.G.Kampunzu, A.B., Bonhomme, M.G., Kanika, M.Geochronology of volcanic rocks and evolution of the Cenozoic western branch of East African Rift systemJournal of African Earth Sciences, Vol. 26, No. 3, Apr. pp. 441-462.Tanzania, Uganda, KenyaGeochronology, Tectonics
DS201702-0197
2017
Boniface, N.Boniface, N.Crystal chemistry of pyrochlore from the Mesozoic PAnd a Hill carbonatite deposit, western Tanzania.Journal of African Earth Sciences, Vol. 126, pp. 33-44.Africa, TanzaniaDeposit - Panda Hill

Abstract: The Mesozoic Panda Hill carbonatite deposit in western Tanzania hosts pyrochlore, an ore and source of niobium. This study was conducted to establish the contents of radioactive elements (uranium and thorium) in pyrochlore along with the concentration of niobium in the ore. The pyrochlore is mainly hosted in sövite and is structurally controlled by NW-SE (SW dipping) or NE-SW (NW dipping) magmatic flow bands with dip angles of between 60° and 90°. Higher concentrations of pyrochlore are associated with magnetite, apatite and/or phlogopite rich flow bands. Electron microprobe analyses on single crystals of pyrochlore yield very low UO2 concentrations that range between 0 and 0.09 wt% (equivalent to 0 atoms per formula unit: a.p.f.u.) and ThO2 between 0.55 and 1.05 wt% (equivalent to 0.1 a.p.f.u.). The analyses reveal high concentrations of Nb2O5 (ranging between 57.13 and 65.50 wt%, equivalent to a.p.f.u. ranging between 1.33 and 1.43) and therefore the Panda Hill Nb-oxide is classified as pyrochlore sensu stricto. These data point to a non radioactive pyrochlore and a deposit rich in Nb at Panda Hill. The Panda Hill pyrochlore has low concentrations of REEs as displayed by La2O3 that range between 0.10 and 0.49 wt% (equivalent to a.p.f.u. ranging between 0 and 0.01) and Ce2O3 ranging between 0.86 and 1.80 wt% (equivalent to a.p.f.u. ranging between 0.02 and 0.03), Pr2O3 concentrations range between 0 and 0.23 wt% (equivalent to 0 a.p.f.u.), and Y2O3 is 0 wt% (equivalent to 0 a.p.f.u.). The abundance of the REEs in pyroclore at the Panda Hill Carbonatite deposit is of no economic significance.
DS202103-0379
2021
Boniface, N.Ganbat, A., Tsujimori, T., Boniface, N., Pastor-Galan, D., Aoki, S., Aoki, K.Crustal evolution of Paleoproterozoic Ubendian Belt ( SW Tanzania) western margin: a central African shield amalgamation take.Gondwana Research, Vol. 91, pp. 286-306. pdfAfrica, Tanzaniamagmatism

Abstract: The Ubendian Belt between the Archean Tanzania Craton and the Bangweulu Block, represents a Paleoproterozoic orogeny of these two constituents of the Congo Craton assembled at ~1.8?Ga, forming the Central African Shield, during the Columbia Supercontinent cycle and consolidated during the Gondwana assembly. Metagranitoids from the Southern and Northern Ufipa Terranes (Western Ubendian Corridor) and those of the Bangweulu Block are compositionally similar and are contemporaneous. The protolith of the Ufipa Terrane is originated from the collided crustal rocks of the Bangweulu Block. New LA-ICPMS zircon U-Pb age of metagranitoids and granoporphyries confirmed magmatic events from 1.89 to 1.85?Ga. The metagranitoids of the Western Ubendian Corridor and that of the Bangweulu Block cannot be distinguished by their trace element characteristics and ages. Geochemically, they belong to high-K calc-alkaline to tholeiite series. The 1.89-1.85?Ga metagranitoids and granoporphyries are characterized by evolved nature, which are common for slab-failure derived magmas. Such geochemical features and the presence of ~2.0?Ga eclogites suggest an Orosirian oceanic subduction and subsequent slab break-off. Melt derived from the mafic upper portion of torn slab led to the partial melting of crust which formed high-K and calc-alkaline, I- and S-type magmatism in the Bangweulu Block and the Ufipa Terrane. Zircons from two metagranites from the Northern Ufipa Terrane show Neoproterozoic (Ediacaran) overprints at ~570?Ma, suggesting the Bangweulu Block collided with the continental margin of the Tanzania Craton. However, we found non-annealed Orosirian apatites in metagranitoids from the Southern Ufipa Terrane and the Kate-Ufipa Complex, implying that areal heterogeneity of the Pan-African tectonothermal overprint in the Ufipa Terrane. All evidences suggest that the Bangweulu Block and the Ubendian Belt participated in the amalgamation of the Central African Shield as separated continents surrounded by oceanic crusts during the Paleoproterozoic Eburnean and the Neoproterozoic Pan-African orogenies.
DS200812-0127
2008
Bonifacie, M.Bonifacie, M.The chlorine isotope composition of Earth's mantleScience, Vol. 319, 5869, March 14, pp. 1518-1520.MantleChlorine
DS1991-0147
1991
Bonilla, M.G.Bonilla, M.G., Lienkaemper, J.J.Factors affecting the recognition of faults exposed in exploratorytrenchesUnited States Geological Survey (USGS) Bulletin, No. 1947, 54p. $ 3.25GlobalStructure, Faults
DS2000-0158
2000
BoninCid, J.P., Nardi, L.V.S., Conciecao, Bonin, Jardim deSaThe alkaline silica saturated ultrapotassic magmatism of the Riacho do Pontal Fold Belt.Journal of South American Earth Sciences, Vol. 13, No. 7, Dec. 1, pp. 661-683.Brazil, northeastAlkaline rocks - not specific to diamonds
DS2000-0767
2000
BoninPla Cid, J., Bitencourt, M.F., Nardi. Conceicao, BoninPaleoproterozoic late orogenic and anorogenic alkaline granitic magmatism from northeast Brasil.Precambrian Research, Vol. 104, No.1-2, Oct.15, pp. 47-75.BrazilOrogeny, Alkaline magmatism
DS1985-0070
1985
Bonin, B.Bonin, B., Giret, A.Clinopyroxene Compositional Trends in Over saturated and Undersaturated Alkaline Ring Complexes.Journal of African Earth Sciences, Vol. 3, No. 1-2, PP. 175-183.Africa, South AfricaBlank
DS1985-0071
1985
Bonin, B.Bonin, B., Giret, A.Contrasting Roles of Rock Forming Minerals in Alkaline Ringcomplexes.Journal of African Earth Sciences, Vol. 3, No. 1-2, PP. 41-49.South Africa, AfricaBlank
DS1985-0533
1985
Bonin, B.Platevoe, B., Bonin, B.The Peloso Alkaline Intrusion (corsica) - a Basic Layered Complex associated with Monzosyenite.Comptes Rendus Academy of Science, Vol. 301, No. 6, JULY 30, PP. 403-406.CorsicaPetrology
DS1986-0088
1986
Bonin, B.Bonin, B.Ring complex granites and anorogenic magmatismElsevier, 188p.GlobalAlkaline magmatism - ring dykes, Magmatism - definition
DS1986-0089
1986
Bonin, B.Bonin, B.Rong complex granites and anorogenic magmatismElsevier, 188p.GlobalAlkaline magmatism - ring dykes, Magmatism - definition
DS1989-0142
1989
Bonin, B.Bonin, B.Distribution of alkaline felsic rocks in within plate magmatismGeological Association of Canada (GAC) Annual Meeting Program Abstracts, Vol. 14, p. A71. (abstract.)GlobalTectonics, Alkaline rocks
DS1989-0143
1989
Bonin, B.Bonin, B., Didier, J., Le Fort, P., et al.Magma -crust interaction and evolutionAugustithis Publishing, (Greece), 362p. $ 38.00GlobalGeophysical aspects, Magma/crust
DS1991-0295
1991
Bonin, B.Conceicao, H., Sabate, P., Bonin, B.The Itiuba alkaline syenite massif, Bahian State, Brasil: geochemical and petrological constraints-relation genesis of rapakivimagmatismPrecambrian Research, Special issue on Precambrian granitoids, Vol. 51, No. 1-4, June pp. 283-314BrazilAlkaline rocks, Itiuba massif
DS1994-0182
1994
Bonin, B.Bonin, B., Bardintzeff, J-M., Giret, A.The distribution of felsic rocks within the alkaline igneous complexMem. Soc. Geol. France, No. 166, pp. 9-24.GlobalAlkaline rocks
DS1994-0183
1994
Bonin, B.Bonin, B., Yobou, R.The Proterozoic quartz syenite nepheline syenite association of Ninakri, Cote d'Ivoire, West Africa.Geological Association of Canada (GAC) Abstract Volume, Vol. 19, p.GlobalAlkaline rocks, Ninakri
DS1996-0155
1996
Bonin, B.Bonin, B., Bardintzeff, J-M., Giret, A.The distribution of felsic rocks within the alkaline igneous centresMem. Soc. Geol. France, Vol. No. 166 pp. 9-24GlobalMagmatic suites, Alkaline rocks
DS2001-0083
2001
Bonin, B.Bardintzeff, J.M., Bonin, B., Rasamimana, G.The Cretaceous Morondava volcanic province: mineralogical, petrological and geochemical aspects.Journal of African Earth Sciences, Vol. 32, No. 2, pp. 299-316.MadagascarBasalts - Ti-P olivines
DS2001-0932
2001
Bonin, B.Pla Cid, J., Nardhi, L.V.S., Coneicao, H., Bonin, B.Anorogenic alkaline granites from northeastern Brasil: major, trace and rare element in magmatic minerals...Journal of African Earth Sciences, Vol. 19, No. 3, Apr. pp.375-98.BrazilMagmatism - metamorphic biotite and Na mafics
DS201012-0037
2010
Bonin, B.Bardintzeff, J-M., Ligeois, J-P., Bonin, B., Bellon, H., Rasamimana, G.Madagascar volcanic provinces linked to the Gondwana break-up: geochemical isotopic evidences for contrasting mantle sources.Gondwana Research, Vol. 18, 2-3, pp. 295-314.Africa, MadagascarGeochronology
DS200712-1012
2007
Bonin, M.Sokoutis, D., Corti, G., Bonin, M., Brun, J.P., Cloetingh, S., Maudit, T., Manetti, P.Modelling the extension of heterogeneous hot lithosphere.Tectonophysics, Vol. 444, pp. 63-79.MantleRheology, back arc extension
DS2003-0287
2003
Bonini, M.Corti, G., Bonini, M., Continelli, S., Innocenti, F., Manetti, P., Sokouris, D.Analogue modelling of continental extension: a review focused on the relations betweenEarth Science Reviews, Vol. 63, No. 3-4, pp. 169-247.MantleMagmatism, tectonics
DS200412-0373
2003
Bonini, M.Corti, G., Bonini, M., Continelli, S., Innocenti, F., Manetti, P., Sokouris, D.Analogue modelling of continental extension: a review focused on the relations between the patterns of deformation and the preseEarth Science Reviews, Vol. 63, no. 3-4, pp. 169-247.MantleMagmatism, tectonics
DS200412-0374
2004
Bonini, M.Corti, G., Bonini, M., Sokoutis, D., innocenti, F., Manetti, P., Cloetingh, S., Mulugeta, G.Continental rift architecture and patterns of magma migration: a dynamic analysis based on centrifuge models.Tectonics, Vol. 23, 2, TC2012 10.1029/2003 TC001561MantleGeodynamics
DS201412-0410
2014
Bonini, M.Isola, I., Mazzarini, F., Bonini, M., Corti, G.Spatial variability of volcanic features in early stage rift settings: the case of the Tanzania divergence, East African rift system.Terra Nova, in press availableAfrica, TanzaniaTectonics
DS201502-0065
2014
Bonini, M.Isola, I., Mazzarini, F., Bonini, M., Cortiz, G.Spatial variability of volcanic features in early-stage rift settings: the case of the Tanzanian divergence, East African Rift.Terra Nova, Vol. 26, pp. 461-468.Africa, TanzaniaRifting, magmatism
DS1993-0135
1993
Bonnati, E.Bonnati, E., Seyler, M., Sushevskaya, N.A cold suboceanic mantle belt at the earth's equator #1Science, Vol. 261, July 16, pp. 315-320MantleGeophysics -gravity, Melting
DS1975-1265
1979
BONNEAUWoussen, G., Gagnon, BONNEAU, Bergeron, DIMROTH, Roy.Lithologie et tectonique des roches Precambriennes et des carbonatites du Saguenay Lac St. Jean.Geological Association of Canada (GAC) Guidebook, Excursion A 3.Quebec, Ungava, LabradorTectonics, Lithology
DS1975-0955
1979
Bonneau, J.Bonneau, J.Le Complexe Alcalin de CrevierGeological Association of Canada (GAC) Field Trip, No. A3, pp. 9-15.QuebecCarbonatite
DS1860-0028
1866
Bonner, J.Bonner, J.Diamonds and other Gems. #3Harper's New Monthly Magazine., Vol. 32, PP. 343-353.United StatesEconomics
DS201812-2772
2018
Bonnet, G.Agard, P., Plunder, A., Angiboust, S., Bonnet, G., Ruh, J.The subduction plate interface: rock record and mechanical coupling ( from long to short timescales).Lithos, Vol. 320-321, pp. 537-566.Mantlesubduction

Abstract: Short- and long-term processes at or close to the subduction plate interface (e.g.,mineral transformations, fluid release, seismicity and more generally deformation) might be more closely related than previously thought. Increasing evidence from the fossil rock record suggests that some episodes of their long geological evolution match or are close to timescales of the seismic cycle. This contribution uses rocks recovered (episodically) from subduction zones, together with insights from thermomechanical modelling, to provide a new dynamic vision of the nature, structure and properties of the plate interface and to bridge the gap between the mechanical behavior of active subduction zones (e.g.,coupling inferred from geophysical monitoring) and fossil ones (e.g.,coupling required to detach and recover subducted slab fragments). Based on critical observations and an exhaustive compilation of worldwide subducted oceanic units (for which the presence near the plate interface, rock types, pressure, temperature, T/P gradients, thickness and timing of detachment can be assessed), the present study demonstrates how long-term mechanical coupling exerts a key control on detachment from the slab and potential rock recovery. Critical assessment of rock T/P characteristics indicates that these fragments can indeed be used as natural probes and provide reliable information on subduction interface dynamics down to ~2.8?GPa. Rock clusters are identified at depths of 30, 5560 and 80?km, with some differences between rock types. Data also reveal a first-order evolution with subduction cooling (in the first ~5?Myr), which is interpreted as reflecting a systematic trend from strong to weak mechanical coupling, after which subduction is lubricated and mostly inhibits rock recovery. This contribution places bounds on the plate interface constitution, regular thickness (<300?m; i.e. where/when there is no detachment), changing geometry and effective viscosity. The concept of ‘coupled thickness' is used here to capture subduction interface dynamics, notably during episodes of strong mechanical coupling, and to link long- and short-term deformation. Mechanical coupling depends on mantle wedge rheology, viscosity contrasts and initial structures (e.g.,heterogeneous lithosphere, existence of décollement horizons, extent of hydration, asperities) but also on boundary conditions (convergence rates, kinematics), and therefore differs for warm and cold subduction settings. Although most present-day subduction zone segments (both along strike and downdip) are likely below the detachment threshold, we propose that the most favorable location for detachment corresponds to the spatial transition between coupled and decoupled areas. Effective strain localization involves dissolution-precipitation and dislocation creep but also possibly brittle fractures and earthquakes, even at intermediate depths.
DS201709-2034
2017
Bonnet, R.Mollex, G., France, L., Furi, E., Bonnet, R., Botcharnikov, R.E., Zimmermann, L., Wilke, S., Deloule, E., Chazot, G., Kazimoto. E.O., Marty, B., Burnard, P.The Oldoinyo Lengai volcano plumbing system architecture, and composition from source to surface.Goldschmidt Conference, abstract 1p.Africa, Tanzaniadeposit, Oldoinyo

Abstract: Cognate xenoliths that have been emitted during the last sub-plinian eruption in 2007-08 at Oldoinyo Lengai (OL) represent a unique opportunity to document the igneous processes occuring within the active magma chamber. Detailed petrographic descriptions coupled to a thermobarometric approach, and to the determination of volatile solubility models, allow us to identify the melt evolution at magma chamber conditions, and the storage parameters (P, T). Results indicate that a fresh phonolite melt (~1060°C) was injected into a crustal magma chamber at 11.5 ±3.5 km depth, in agreement with geophysical surveys performed during the eruption. The phonolite contains high volatile contents: 3.2 wt.% H2O and 1.4 wt.% CO2. The liquid line of descent highlights an evolution to nephelinite compositions by cooling down to 880°C. Our results support previous results related to this eruption, and are similar to the historical products emitted during the whole volcano history, allowing us to suggest that no major modification in the plumbing system has occured during the OL evolution. New noble gas results show that: i. fumaroles display constant He isotopic signature since 1988; ii. Cognate xenoliths documenting the active magma chamber and fumaroles display similar He isotopic values (6.58±0.46RA, and 7.31±0.40RA, respectively); iii. OL He isotopic composition is similar to that of other silicate volcanoes of the Arusha region, and comparable to the typical subcontinental lithospheric mantle (SCLM) range (5.2 to 7.0 RA); iv. Ne isotopic ratio of OL is following the MORB signature. Those results are interpreted as showing that 1/ no major modification in the hydrothermal system architecture has occured since 1988 despite major modification of the summit crater morphology, 2/ no contamination by either the atmospheric gases, or crustal material assimilation has occured between the magma chamber and the surface, and 3/ the source of OL and of the other silicate volcanoes in the Arusha region is a SCLM metasomatized by asthenospheric fluids.
DS202104-0616
2021
Bonnetti, C.Wu, B., Hu, Y-Q., Bonnetti, C., Xu, C., Wang, R-C., Zhang, Z-S., Li, Z-Y., Yin, R.Hydrothermal alteration of pyrochlore group minerals from the Miaoya carbonatite complex, central China and its implications for Nb mineralization.Ore Geology Reviews, Vol. 132, 1040459, 16p. PdfChinadeposit - Miaoya

Abstract: Carbonatite represents a major host rock for niobium (Nb) resources worldwide. Both magmatic and post-magmatic metasomatic processes are crucial for Nb mineralization in carbonatites. However, the roles of these metasomatic processes are difficult to be evaluated due to their multiple origins and complexity of the physico-chemical conditions. In this study, we present detailed mineralogical investigations of pyrochlore group minerals and chemical U-Th-Pb geochronology of uraninite within the Miaoya carbonatite complex, aiming to better characterize the role of post-magmatic metasomatic events. The Miaoya complex (ca. 420-440?Ma) hosts the second largest carbonatite-related Nb deposit in China, mainly in the form of pyrochlore group minerals, ferrocolumbite and Nb-bearing rutile. Primary pyrochlore group minerals evolved from pyrochlore to uranpyrochlore, and ultimately reaching the betafite end-member during the magmatic stage. They have then experienced an episode of metasomatic events at 235.4?±?4.1?Ma, as determined by U-Th-Pb chemical ages of secondary uraninite. Fluids activity for uranpyrochlore alteration was concomitant with the hydrothermal reworking of REE mineralization, which was probably related to tectono-thermal events that occurred during the Triassic closure of the ancient Mianlue Ocean. During this process, hydration and decomposition of uranpyrochlore were characterized by the leaching of Na, Ca and F from its structure, the incorporation of Fe, Si, Sr and Ba from the fluids, and the final in situ replacement by secondary ferrocolumbite, uraninite and Nb-bearing rutile. In addition, parts of Nb and U liberated from uranpyrochlore by metamictization were then transported over distances of several hundreds of microns in relatively reducing (Fe, Si, S, CO2)-bearing fluids under high temperature, and were ultimately re-precipitated in amorphous Fe-Si-U-Nb-bearing oxide veins and poorly crystallized Nb-Ti-Ca-Fe-rich oxides. The relatively weak fluids activity failed to efficiently promote the Nb re-enrichment.
DS2001-0199
2001
Bonneville, A.Clouard, V., Bonneville, A.How many Pacific hotspots are fed by deep mantle plumes?Geology, Vol. 29, No. 8, Aug. pp. 695-98.MantleHot spots - not specific to diamonds
DS200812-0424
2008
Bonneville, A.Goutorbe, B., Lucazeau, F., Bonneville, A.The thermal regime of South African continental margins.Earth and Planetary Science Letters, Vol. 267, 1-2, pp.256-265.Africa, South AfricaGeothermometry
DS1860-0578
1888
BonneyBonneyThe Diamonds Origin Settled by Prof. BonneyPanama Columbia Star Herald., AUGUST 9TH.Africa, 'South AfricaDiamond Genesis
DS1860-0692
1891
Bonney, T.G.Bonney, T.G., Raisin, C.A.Report on Some Rock Specimens from the Kimberley Diamond MinGeology Magazine , Dec. 3, Vol. 7, PP. 412-415.Africa, South Africa, Griqualand WestDiamond mines, mineralogy, petrology
DS1860-0883
1895
Bonney, T.G.Bonney, T.G., Raisin, C.A.Notes on the Diamond Bearing Rock of Kimberley, South Africa. the Kimberley Diamond Mines.Geology Magazine , Dec. 4, Vol. 2, PP. 496-502. Neues Jahrbuch f?r Mineralogie BD. 2, PP. 43Africa, South Africa, Cape ProvinceDiamond mines, mineralogy, petrology
DS1860-0971
1897
Bonney, T.G.Bonney, T.G.On Some Rock Specimens from Kimberley, South AfricaGeology Magazine, Dec. 4, Vol. 4, PP. 448-453; PP. 497-502. Neues Jahrbuch f?rAfrica, South Africa, Cape ProvinceDiamond mines, mineralogy, petrology
DS1860-1072
1899
Bonney, T.G.Bonney, T.G.The Parent Rock of the Diamond in South Africa #2Geology Magazine, Dec. 4, Vol. 6, PP. 309-321. ALSO: REC. SCI. (CANADA), Vol.Africa, South Africa, Cape ProvinceDiamond mines, mineralogy, petrology
DS1860-1073
1899
Bonney, T.G.Bonney, T.G.The Original Rock of the South African DiamondNatural Science (London), Vol. 15, PP. 173-182.Africa, South Africa, Cape ProvinceDiamond mines, mineralogy, petrology
DS1860-1074
1899
Bonney, T.G.Bonney, T.G.The Parent Rock of the Diamond in South Africa #1Royal Society Proceedings, Vol. 65, PP. 223-236. ALSO: NATURE (London), Vol. 60, PP. 62Africa, South Africa, Cape ProvinceDiamond mines, mineralogy, petrology
DS1900-0014
1900
Bonney, T.G.Bonney, T.G.The Parent Rock of the Diamond. Reply to CriticismGeology Magazine (London), Vol. 7, PP. 244-248.Africa, South AfricaDiamond Genesis
DS1900-0058
1901
Bonney, T.G.Bonney, T.G.Additional Notes on Boulders and Other Rock Specimens from The Newland Diamond Mines, Griqualand West.Royal Society. (London) Proceedings, Vol. 67, PP. 475-484. ALSO: REVIEW IN NATURE (London), Vol.Africa, South AfricaMineralogy, Petrology, Kimberlite Mines And Deposits
DS1900-0310
1905
Bonney, T.G.Bonney, T.G., Raisin, C.A.The Microscopic Structure of Minerals Forming Serpentine And Their Relation to its History.Quarterly Journal of Geological Society, Vol. 61, PP. 690-714. ALSO. Proceedings Geological Society 1904-1905, P. 1Africa, South AfricaRelated Rocks
DS1900-0648
1908
Bonney, T.G.Bonney, T.G.On the Supposed Kimberlite Magma and Eclogite ConcretionsGeological Society of South Africa Transactions, Vol. 10, PP. 95-100. ALSO: CENTRALL GEOL., Vol. 11, P. 243Africa, South AfricaPetrology, Diamond Genesis
DS1900-0649
1908
Bonney, T.G.Bonney, T.G.The Diamondiferous Rocks of KimberleyNature., Vol. 77, No. 1994, Jan. 16TH. P. 246.Africa, South AfricaPetrology, Kimberlite Mines And Deposits
DS201806-1234
2018
Bonnin, M.Maquire, R., Ritsema, J., Bonnin, M., van Keken, P.E., Goes, S.Evaluating the resolution of deep mantle plumes in teleseismic traveltime tomography.Journal of Geophysical Research, Vol. 123, 1. pp. 384-400.Mantlegeophysics - seismic

Abstract: The strongest evidence to support the classical plume hypothesis comes from seismic imaging of the mantle beneath hot spots. However, imaging results are often ambiguous and it is questionable whether narrow plume tails can be detected by present?day seismological techniques. Here we carry out synthetic tomography experiments based on spectral element method simulations of seismic waves with period T > 10 s propagating through geodynamically derived plume structures. We vary the source?receiver geometry in order to explore the conditions under which lower mantle plume tails may be detected seismically. We determine that wide?aperture (4,000-6,000 km) networks with dense station coverage (<100-200 km station spacing) are necessary to image narrow (<500 km wide) thermal plume tails. We find that if uncertainties on traveltime measurements exceed delay times imparted by plume tails (typically <1 s), the plume tails are concealed in seismic images. Vertically propagating SKS waves enhance plume tail recovery but lack vertical resolution in regions that are not independently constrained by direct S paths. We demonstrate how vertical smearing of an upper mantle low?velocity anomaly can appear as a plume originating in the deep mantle. Our results are useful for interpreting previous plume imaging experiments and guide the design of future experiments.
DS201509-0432
2015
Bono, R.K.Tarduno, J.A., Cottrell, R.D., Davis, W.J., Nimmo, F., Bono, R.K.A Hadean to Paleoarchean geodynamo recorded by single zircon crystals. ( Jack Hills)Science, Vol. 349, 6247, pp. 521-524.MantleGeodynamo

Abstract: Knowing when the geodynamo started is important for understanding the evolution of the core, the atmosphere, and life on Earth. We report full-vector paleointensity measurements of Archean to Hadean zircons bearing magnetic inclusions from the Jack Hills conglomerate (Western Australia) to reconstruct the early geodynamo history. Data from zircons between 3.3 billion and 4.2 billion years old record magnetic fields varying between 1.0 and 0.12 times recent equatorial field strengths. A Hadean geomagnetic field requires a core-mantle heat flow exceeding the adiabatic value and is suggestive of plate tectonics and/or advective magmatic heat transport. The existence of a terrestrial magnetic field before the Late Heavy Bombardment is supported by terrestrial nitrogen isotopic evidence and implies that early atmospheric evolution on both Earth and Mars was regulated by dynamo behavior.
DS200612-0150
2006
Bonow, J.M.Bonow, J.M., Lidmar Bergstrom, K., Japsen, P.Paleosurfaces in central West Greenland as reference for identification of tectonic movements and estimation of erosion.Global and Planetary Change, Vol. 50, 3-4, pp. 161-183.Europe, GreenlandTectonics
DS1997-1077
1997
Bons, P.D.Soesoo, A., Bons, P.D., Gray, D.R., Foster, D.A.Divergent double subduction: tectonics and petrologic consequencesGeology, Vol. 25, No. 8, August pp. 755-758.MantleTectonics, Subduction
DS2001-0122
2001
Bons, P.D.Bons, P.D., Dougherty-Page, J., Elburg, M.A.Stepwise accumulation and ascent of magmasJournal of Metamorphic Geology, Vol. 19, No. 5, Sept. pp. 625-32.MantleMagmatism
DS1900-0536
1907
Bonsall, P.J.Bonsall, P.J.Lecture on the DiamondJewellers Circular Keystone, Vol. 53, No. 25, Jan. 23RD. P. 35.GlobalGeology
DS1988-0070
1988
Bonvalot, S.Bonvalot, S., Villeneurve, M., Legeley, A., Albouy, Y.Leve gravimetrique du sud-ouest du craton Ouest -Africain.(in French)C.r. Academy Of Science Paris, Vol. 307, ser. II, pp. 1863-1868GlobalGeophysics-gravity, Tectonics
DS1991-0148
1991
Bonvalot, S.Bonvalot, S., Villeneuve, M., Albouy, Y.Gravity dat a interpretation in Sierra Leone- evidence of collision suture in the Rokelides Pan-African orogenic belt.(in French)Comptes Rendus de l'Academie des Sciences Serie II, Vol. 312, No. 8, April pp. 841-848Sierra LeoneGeophysics -gravity, Tectonics
DS1860-0494
1886
Bonwick, J.Bonwick, J.Resources of the Cape Colony 1886London:, Africa, South AfricaHistory
DS1960-0125
1961
Boocock, C.Boocock, C.Annual Report of the Geological Survey Department for the Year 1961.Geological Survey Bechuanaland Protectorate, 35P. DIAMONDS P. 7.BotswanaDiamond Prospecting
DS1960-0220
1962
Boocock, C.Boocock, C., Van straten, O.J.Notes on the Geology and the Hydrogeology of the Central Kalahari Region, Bechuana land Protectorate.Geological Society of South Africa Transactions, Vol. 65, PP. 125-171.BotswanaGeology
DS1960-0520
1965
Boocock, C.Boocock, C.Mineral Resources of the Bechuana land ProtectorateSpecial Publication Reprinted From Overseas Geology And Mine, Vol. 9, No. 4, PP. 369-417.BotswanaKimberlite, Diamond Prospecting
DS200412-2023
2004
Booker, J.Unsworth, M., Wenbo, W., Jones, A.G., Li, S., Bedrosian, P., Booker, J., Sheng, J., Ming, D., Handong, T.Crustal and upper mantle structure of northern Tibet imaged with magnetotelluric data.Journal of Geophysical Research, Vol. 109, B2, Feb. 13, 10.1029/2002 JB002305Asia, TibetTectonics, geophysics - seismics
DS1988-0648
1988
Booker, J.R.Smith, J.T., Booker, J.R.Magnetotelluric inversion for minimum structureGeophysics, Vol. 53, No. 12, December pp. 1565-1576GlobalGeophysics, Tellurics
DS1997-1226
1997
Booker, J.R.Wannamaker, P.E., Johnston, J.M., Stodt, J.A., Booker, J.R.Anatomy of the southern Cordilleran hingeline, Utah and Nevada, from deep electric resistivity profilingGeophysics, Vol. 62, No. 4, July-Aug., pp. 1069-86Utah, Nevada, Basin and RangeGeophysics, Tectonics
DS200912-0720
2009
Booker, R.Sparks, S.R., Booker, R., Field, M., Kavanagh, J.Volatiles in kimberlite magmas: experimental constraints.GAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyTechnologyMelting
DS201605-0814
2016
Bookless, T.Bookless, T.The selection of high-pressure grinding rolls for a diamond flow sheet.Diamonds Still Sparkling SAIMM 2016 Conference, Mar. 14-17, pp. 117-128.TechnologyMining - applied
DS1988-0071
1988
Bookstrom, A.A.Bookstrom, A.A., Carten, R.B., Shannon, J.R., Smith, R.P.Origins of bimodal leucogranite-lamprophyre suites, Climax and Red Mountain porphyry molydenum systems, Colorado: petrologic and strontium isotopicevidenceColorado School of Mines Quarterly, Vol. 83, No. 2, Summer pp. 1-24ColoradoLamprophyre, Lamprophyre petrology
DS201012-0610
2010
Boon, K.A.Ramsey, M.H., Boon, K.A.New approach to geochemical measurement: estimation of measurement uncertainty from sampling, rather than an assumption of representative.Geostandards and Geoanaltyical Research, Vol. 34, 3, pp. 293-304.TechnologySampling - not specific to diamonds
DS1860-0457
1885
Boon, M.J.Boon, M.J.History of the Orange Free StateLondon:, 248P.Africa, South AfricaHistory
DS202203-0336
2022
Boone, S.C.Boone, S.C., Dalton, H., Prent, A., Kohlman, F., Theile, M., Greau, Y., Florin, G., Noble, W., Hodgekiss, S-A., Ware, B., Phillips, D., Kohn, B., O'Reilly, S., Gleadow, A., McInnes, B., Rawling, T.AusGeochem: an open platform for geochemical data preservation, dissemination and synthesis. Lithodat Pty *** not specific to diamonds but excellent concept/platformGeostandards and Geoanalysis Research, doi.org/10.1111/GGR.12419 34p. PdfAustraliageochemistry

Abstract: To promote a more efficient and transparent geochemistry data ecosystem, a consortium of Australian university research laboratories called the AuScope Geochemistry Network (AGN) assembled to build a collaborative platform for the express purpose of preserving, disseminating, and collating geochronology and isotopic data. In partnership with geoscience-data-solutions company Lithodat Pty Ltd, the open, cloud-based AusGeochem platform (https://ausgeochem.auscope.org.au) was developed to simultaneously serve as a geosample registry, a geochemical data repository, and a data analysis tool. Informed by method-specific groups of geochemistry experts and established international data reporting practices, community-agreed database schemas were developed for rock and mineral geosample metadata and secondary ion mass spectrometry U-Pb analysis, with additional models for laser ablation inductively-coupled mass spectrometry U-Pb and Lu-Hf, Ar-Ar, fission-track and (U-Th-Sm)/He under development. Collectively, the AusGeochem platform provides the geochemistry community with a new, dynamic resource to help facilitate FAIR (Findable, Accessible, Interoperable, Reusable) data management, streamline data dissemination and advanced quantitative investigations of Earth system processes. By systematically archiving detailed geochemical (meta-)data in structured schemas, intractably large datasets comprising thousands of analyses produced by numerous laboratories can be readily interrogated in novel and powerful ways. These include rapid derivation of inter-data relationships, facilitating on-the-fly data compilation, analysis, and visualisation.
DS201809-2043
2018
Boonsoong, A.Ivarsson, M., Skogby, H., Bengtson, S., Siljestrom, S., Ounchanum, P., Boonsoong, A., Kruachanta, M., Marone, F., Belivanova, V., Holstrom, S.Intricate tunnels in garnets from soils and river sediments in Thailand - possible endolithic microborings.PluS One, Vol. 13, 8, doi:10.1371/journal.pone.0200351Asia, Thailandgarnets

Abstract: Garnets from disparate geographical environments and origins such as oxidized soils and river sediments in Thailand host intricate systems of microsized tunnels that significantly decrease the quality and value of the garnets as gems. The origin of such tunneling has previously been attributed to abiotic processes. Here we present physical and chemical remains of endolithic microorganisms within the tunnels and discuss a probable biological origin of the tunnels. Extensive investigations with synchrotron-radiation X-ray tomographic microscopy (SRXTM) reveal morphological indications of biogenicity that further support a euendolithic interpretation. We suggest that the production of the tunnels was initiated by a combination of abiotic and biological processes, and that at later stages biological processes came to dominate. In environments such as river sediments and oxidized soils garnets are among the few remaining sources of bio-available Fe2+, thus it is likely that microbially mediated boring of the garnets has trophic reasons. Whatever the reason for garnet boring, the tunnel system represents a new endolithic habitat in a hard silicate mineral otherwise known to be resistant to abrasion and chemical attack.
DS201212-0080
2012
Boos, A.Boos, A., Holm-Muller, K.A theoretical overview of the relationship between the resouce curse and genuine savings as an indicator for "weak" sustainability.Natural Resources Forum, Vol. 36, 3, pp. 145-159.GlobalEconomics
DS1859-0002
1644
Boot, A.B.Boot, A.B.Le Parfait Joaillier. Translated from Latin by J. BachonFrance, GlobalKimberlite, Kimberley, Janlib, Gemology
DS200712-1238
2007
Booth, A.L.Zhao, R., Zhang, R.Y., Liou, J.G., Booth, A.L., Pope, E.C., Chamberlain, C.P.Petrochemistry oxygen isotopes and U-Pb SHRIMP geochronology of mafic ultramafic bodies from the Sulu UHP terrane, China.Journal of Metamorphic Geology, Vol. 25, 2, pp. 207-224.ChinaUHP
DS1997-0196
1997
Booth, J.Clemson, J., Cartwright, J., Booth, J.Structural segmentation and the influence of basement structure on the Namibia passive margin.Journal of the Geological Society of London, Vol. 154, No. 3, pp. 477-482.NamibiaStructure, Basement
DS2003-0227
2003
Booth, S.R.Catherall, A.T., Eaves, L., King, P.J., Booth, S.R.Magnetic levitation: floating gold in cryogenic oxygenNature, Vol. 6932, April 10, pp. 579.MantleGeophysics - magnetics
DS200412-0296
2003
Booth, S.R.Catherall, A.T., Eaves, L., King, P.J., Booth, S.R.Magnetic levitation: floating gold in cryogenic oxygen.Nature, Vol. 6932, April 10, pp. 579.MantleGeophysics - magnetics
DS1860-0972
1897
Booth, W.F.Booth, W.F.The South African Diamond MinesColliery Eng., Vol. 17, MAY, PP. 429-430.Africa, South AfricaMining Engineering
DS201904-0744
2019
Booth-Rea, G.Hidas, K., Garrido, C.J., Booth-Rea, G., Marchesi, C., Bodinier, J-L., Dautria, J-M., Louni-Hacini, A., Azzouni-Sekkal, A.Lithosphere tearing along STEP faults and synkenetic formation of lherzolite and wehrlite in the shallow subcontinental mantle. OranSolid Earth, https://doi.org/10.5194 /se-2019-32 36p.Mantle, Africa, Algeriasubduction

Abstract: Subduction-Transform Edge Propagator (STEP) faults are the locus of continual lithospheric tearing at slab edges, resulting in sharp changes in the lithospheric and crustal thickness and triggering lateral and/or near-vertical mantle flow. However, the mechanisms at the lithospheric mantle scale are still poorly understood. Here, we present the microstructural study of olivine-rich lherzolite, harzburgite and wehrlite mantle xenoliths from the Oran volcanic field (Tell Atlas, NW Algeria). This alkali volcanic field occurs along a major STEP fault responsible for the Miocene westward slab retreat in the westernmost Mediterranean. Mantle xenoliths provide a unique opportunity to investigate the microstructures in the mantle section of a STEP fault system. The microstructures of mantle xenoliths show a variable grain size ranging from coarse granular to fine-grained equigranular textures uncorrelated with modal variations. The major element composition of the mantle peridotites provides temperature estimates in a wide range (790-1165?°C) but in general, the coarse-grained and fine-grained peridotites suggest deeper and shallower provenance depth, respectively. Olivine grain size in the fine-grained peridotites depends on the size and volume fraction of the pyroxene grains, which is consistent with pinning of olivine grain growth by pyroxenes as second phase particles. In the coarse-grained peridotites, well-developed olivine crystal preferred orientation (CPO) is characterized by orthorhombic and [100]-fiber symmetries, and orthopyroxene has a coherent CPO with that of olivine, suggesting their coeval deformation by dislocation creep at high-temperature. In the fine-grained microstructures, along with the weakening of the fabric strength, olivine CPO symmetry exhibits a shift towards [010]-fiber and the [010]- and [001]-axes of orthopyroxene are generally distributed subparallel to those of olivine. These data are consistent with deformation of olivine in the presence of low amounts of melts and the precipitation of orthopyroxenes from a melt phase. The bulk CPO of clinopyroxene mimics that of orthopyroxene via a topotaxial relationship of the two pyroxenes. This observation points to a melt-related origin of most clinopyroxenes in the Oran mantle xenoliths. The textural and geochemical record of the peridotites are consistent with interaction of a refractory harzburgite protolith with a high-Mg# melt at depth (resulting in the formation of coarse-grained clinopyroxene-rich lherzolite and wehrlite), and with a low-Mg# evolved melt in the shallow subcontinental lithospheric mantle (forming fine-grained harzburgite). We propose that pervasive melt-peridotite reaction - promoted by lateral and/or near-vertical mantle flow associated with lithospheric tearing - resulted in the synkinematic crystallization of secondary lherzolite and wehrlite and played a key effect on grain size reduction during the operation of the Rif-Tell STEP fault. Melt-rock reaction and secondary formation of lherzolite and wehrlite may be widespread in other STEP fault systems worldwide.
DS202001-0022
2019
Boothroyd, S.C.Jones, T.J., Reynolds, C.D., Boothroyd, S.C.Fluid dynamic induced break-up during volcanic eruptions. ( mentions kimberlite and carbonatite)Nature Communications, doi.org/10.1038/ s41467-019-11750-4 7p. pdf Mantlemelting

Abstract: Determining whether magma fragments during eruption remains a seminal challenge in volcanology. There is a robust paradigm for fragmentation of high viscosity, silicic magmas, however little is known about the fragmentation behaviour of lower viscosity systems—the most abundant form of volcanism on Earth and on other planetary bodies and satellites. Here we provide a quantitative model, based on experiments, for the non-brittle, fluid dynamic induced fragmentation of low viscosity melts. We define the conditions under which extensional thinning or liquid break-up can be expected. We show that break-up, both in our experiments and natural eruptions, occurs by both viscous and capillary instabilities operating on contrasting timescales. These timescales are used to produce a universal break-up criterion valid for low viscosity melts such as basalt, kimberlite and carbonatite. Lastly, we relate these break-up instabilities to changes in eruptive behaviour, the associated natural hazard and ultimately the deposits formed.
DS202007-1151
2019
Boothroyd, S.C.Jones, T.J., Reynolds, C.D., Boothroyd, S.C.Fluid dynamics induced break up during volcanic eruptions.Nature Communications, Vol. 10, 1, 10.1038/s41467-019-11750-4.Mantlegeodynamics

Abstract: Determining whether magma fragments during eruption remains a seminal challenge in volcanology. There is a robust paradigm for fragmentation of high viscosity, silicic magmas, however little is known about the fragmentation behaviour of lower viscosity systems—the most abundant form of volcanism on Earth and on other planetary bodies and satellites. Here we provide a quantitative model, based on experiments, for the non-brittle, fluid dynamic induced fragmentation of low viscosity melts. We define the conditions under which extensional thinning or liquid break-up can be expected. We show that break-up, both in our experiments and natural eruptions, occurs by both viscous and capillary instabilities operating on contrasting timescales. These timescales are used to produce a universal break-up criterion valid for low viscosity melts such as basalt, kimberlite and carbonatite. Lastly, we relate these break-up instabilities to changes in eruptive behaviour, the associated natural hazard and ultimately the deposits formed.
DS200712-0788
2007
Boovarsson, R.Olsson, S., Roberts, R.G., Boovarsson, R.Analysis of waves converted from S to P in the upper mantle beneath the Baltic Shield.Earth and Planetary Science Letters, Vol. 257, 1-2, May 15, pp. 37-46.Europe, Norway, Sweden, Finland, Kola PeninsulaGeophysics - seismics
DS1985-0072
1985
Boppart, H.Boppart, H., Van straaten, J., Silvera, I.F.Raman Spectra of Diamond at High PressuresPhysical Review B: Condensed Matter., Vol. 32, No. 2, JULY 15TH. PP. 1423-1425.GlobalBlank
DS201312-0571
2012
Borah, K.Mandal, N., Charavarty, K.H., Borah, K., Rai, S.S.Is a cation ordering transition of the Mg-Fe olivine phase in the mantle responsible for the shallow mantle seismic discontinuity beneath the Indian craton?Journal of Geophysical Research, 9225IndiaHales discontinuity
DS1989-0045
1989
Borbely, J.Audino, N., Perrin, T., Borbely, J.A corporate online database: perspectives on anin-house text retrieval system Part 1. Design and implementationDatabase, Vol. 12, No. 3, June pp. 30-35. Database # 17936GlobalComputer, Program - in house text retrieval
DS1986-0302
1986
Borch, R.Green, H.W., Borch, R., Hobbs, B.E.The pressure dependence of creep in olivine: consequences formantleflowProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 244-246GlobalBlank
DS1991-0799
1991
Borch, R.S.Jin, Z.M, Green, H.W. II, Borch, R.S., Tingle, T.N.Unusual spinel garnet lherzolite xenoliths from basalts in eastern China:constraints on the late Tertiary thermal structure of the upper mantleProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 212-213ChinaLherzolite xenoliths -analyses, Geochemistry
DS1992-1739
1992
Borch, R.S.Zhen-Ming Jin, Green, H.W., Borch, R.S., Shu-Yan Jin, Tingle, T.N.Rare garnet and spinel garnet peridotite xenoliths -token of a modern back-arc geotherm beneath eastern ChinaInternational Symposium Cenozoic Volcanic Rocks Deep seated xenoliths China and its, Abstracts pp. 67-68ChinaXenoliths, Peridotite
DS1988-0051
1988
Borcherding, R.M.Berendsen, P., Borcherding, R.M., Doveton, J., Gerhard, L.Texaco Persch # 1, Washington County, Kansas:preliminary geologic report of pre-Phanerozoic rocksKansas Geological Survey Open File Rept, No. 88-22, 116pKansasMidcontinent, Tectonics
DS1960-0022
1960
Borchers, D.Borchers, D.Deepening of the No. 1 Vertical Shaft at Premier (transvaal) Diamond Mining Co. Ltd. with Introduction by E.j.b. Sewell.Institute of Mining and Metallurgy. Transactions, Vol. 69, PP. 63-81.South AfricaMining Methods, Recovery
DS1970-0029
1970
Borchers, D.Borchers, D., Stocken, C.G., Dall, A.E.Beach Mining at Consolidated Diamond Mines of Southwest Africa Limited: Exploitation of the Area between the High and Low Water Marks.Commonwealth Min. Met. Congress 9th., Vol. 1, PP. 571-590.Southwest Africa, NamibiaPlacers, Diamond Mining Recovery, Littoral
DS1860-1019
1898
Bordeaux, A.Bordeaux, A.Les Mines de L'afrique du Sud (1898) - South Africa MinesParis: Dunod., 211P.Africa, South AfricaMining Engineering
DS1860-1020
1898
Bordeaux, A.Bordeaux, A.L'exploitation des Mines de Diamants a KimberleyRevue University Mines (liege), 3RD. SER. Vol. 43, PP. 221-237. ALSO: BERGM. ZTG. (LEIPZIG)Africa, South Africa, Cape ProvinceMining Engineering
DS1860-1021
1898
Bordeaux, A.Bordeaux, A.Rhodesie et Transvaal: Impressions de Voyage. Les Mines de L'afrique du Sud, Transvaal, Rhodesie, Etc.Paris: Librairie Plon., 284P.South Africa, Transvaal, ZimbabweTravelogue
DS202105-0790
2021
Border, A.Slezak, P., Spandler, C., Border, A., Whittock, K.Geology and ore genesis of the carbonatite-associated Yangibana REE district, Gascoyne Province, Western Australia.Mineralium Deposita, 10.1007/s00126-020-01026-z 20p. PdfAustraliaREE

Abstract: The Yangibana rare earth element (REE) district consists of multiple mineral deposits/prospects hosted within the Mesoproterozoic Gifford Creek Carbonatite Complex (GCCC), Western Australia, which comprises a range of rock types including calcite carbonatite, dolomite carbonatite, ankerite-siderite carbonatite, magnetite-biotite dykes, silica-rich alkaline veins, fenite, glimmerites and what have historically been called “ironstones”. The dykes/sills were emplaced during a period of extension and/or transtension, likely utilising existing structures. The Yangibana REE deposits/prospects are located along many of these structures, particularly along the prominent Bald Hill Lineament. The primary ore mineral at Yangibana is monazite, which is contained within ankerite-siderite carbonatite, magnetite-biotite dykes and ironstone units. The ironstones comprise boxwork-textured Fe oxides/hydroxides, quartz, chalcedony and minor monazite and subordinate rhabdophane. Carbonate mineral-shaped cavities in ironstone, fenite and glimmerite alteration mantling the ironstone units, and ankerite-siderite carbonatite dykes altering to ironstone-like assemblages in drill core indicate that the ironstones are derived from ankerite-siderite carbonatite. This premise is further supported by similar bulk-rock Nd isotope composition of ironstone and other alkaline igneous rocks of the GCCC. Mass balance evaluation shows that the ironstones can be derived from the ankerite-siderite carbonatites via significant mass removal, which has resulted in passive REE concentration by ~?2 to ~?10 times. This mass removal and ore tenor upgrade is attributed to extensive carbonate breakdown and weathering of ankerite-siderite carbonatite by near-surface meteoric water. Monazite from the ironstones has strong positive and negative correlations between Pr and Nd, and Nd and La, respectively. These relationships are reflected in the bulk-rock drill assays, which display substantial variation in the La/Nd throughout the GCCC. The changes in La/Nd are attributed to variations in primary magmatic composition, shifts in the magmatic-hydrothermal systems related to CO2 versus water-dominated fluid phases, and changes in temperature.
DS1991-0149
1991
Border, S.N.Border, S.N.Optimization of cut off grades during design of underground MinesAustralian Institute of Mining and Metallurgy (AusIMM) Bulletin, No. 5, September pp. 14-20AustraliaEconomics, Cut-off grades
DS2001-0123
2001
Border, S.N.Border, S.N., Stitt, P.H.Valuation of industrial minerals and construction materials projects: some pitfallsValmin 01, Mineral Asset Valuation Oct. 25-6th., pp.171-80.AustraliaEconomics - costs, Mineral reserves, resources, valuation, exploration
DS1987-0290
1987
Bordet, P.Hernandez, J., De Larouziere, F.D., Bolze, J., Bordet, P.Neogene magmatism in the Western Mediterranean area, Southern Spain, North Africa- strike slip faulting and calc alkaline volcanism.(in French)Bulletin Soc. Geol. Fr.(in French), Vol. 3, No. 2, pp. 257-267GlobalLamproite, Shoshonite
DS201312-0946
2013
Bordholdt, J.P.Walker, A.M., Ammann, M.W., Stackhouse, S., Wookey, J., Bordholdt, J.P., Dobson, D.Anisotropy: a cause of heat flux variation at the CMB?Goldschmidt 2013, 1p. AbstractMantlePerovskite
DS1998-1594
1998
BordingWu, W.J., Lines, L., Burton, Lu, Zhu, Jamieson, BordingPrestack depth migration of an Alberta foothills dat a set: the Husky experience.Geophysics, Vol. 63, No. 2, pp. 392-8.AlbertaGeophysics - seismics, Tectonics, thrust
DS1998-0139
1998
Bordon, V.Bordon, V.Mineralogical and chemical model of Belrussian diatremes7th International Kimberlite Conference Abstract, p. 89.Russia, BelarusDiatremes, Deposit - Rogachev-Zhlobin
DS1998-0140
1998
Bordon, V.Bordon, V., Astapenko, V.Braslev field: the prospects of discovering Diamondiferous rocks7th International Kimberlite Conference Abstract, p. 90.Russia, BelarusGeophysics, Anomaly - Soroki, Vasilkishki, Churilovo
DS1993-0136
1993
Borduas, B.Borduas, B., Martel, J-J.The Le Tac Township kimberlite discoveryQuebec Exploration Conference summaries held September 15-1th. Val d'Or, pp. 13-16QuebecLe Tac Township
DS200612-0526
2006
Bordy, E.M.Hanson, E.K., Moore, J.M., Robey, J., Bordy, E.M., Marsh, J.S.Re-estimation of erosion levels in Group I and II kimberlites between Lesotho, Kimberley and Victoria West, South Africa.Emplacement Workshop held September, 5p. extended abstractAfrica, South Africa, LesothoCrustal xenoliths
DS201012-0266
2009
Bordy, E.M.Hanson, E.K., Moore, J.M., Bordy, E.M., Marsh, J.S., Howarth, G., Robey, J.V.A.Cretaceous erosion in central South Africa: evidence from upper crustal xenoliths in kimberlite diatremes.South African Journal of Geology, Vol. 112, 2, pp. 125-140.Africa, South AfricaGeomorphology
DS1986-0187
1986
Boreiko, L.G.Dobryanskii, L.A., Kurilov, M.V., Boreiko, L.G., Zakharov, E.P.Characteristics of the distribution of trace elements in Rocks of the diamond bearing suite of the Chistyakovo Snezhnaya trough of the DonetsBasin.(Russian)Dopov. Akad. Nauk UKR. RSR Ser. B., Geokl. Khim. Biol., (Russian), No. 3, pp. 5-8RussiaBlank
DS202106-0950
2021
Boren, G.Le Pape, F., Jones, A.G., Jessell, M.W., Hogg, C., Siebenaller, L., Perrouty, S., Tour, A., Oiuya, P., Boren, G.The nature pf the southern West Africa craton lithosphere inferred from its electrical resistivity.Precambrian Research, Vol. 358, 106190, 15p. Pdf Africageophysics

Abstract: The West-African craton is defined by a combination of Archean and Palaeoproterozoic rocks that stabilised at ~2 Ga towards the end of the Paleoproterozoic Eburnean Orogeny, and therefore may reflect the transition from Archean to modern tectonic processes. Exploring its present lithospheric architecture aids further understanding of not only the craton’s stability through its history but also its formation. We investigate the lithospheric structure of the craton through analysing and modelling magnetotelluric (MT) data from a 500-km-long east-west profile in northern Ghana and southern Burkina Faso crossing part of the Baoulé-Mossi Domain and reaching the Volta Basin in the south-eastern part of the craton. Although the MT stations are along a 2D profile, due to the complexity of the structures characterising the area, 3D resistivity modelling of the data is performed to obtain insights on the thermal signature and composition of the subcontinental lithosphere beneath the area. The thermal structure and water content estimates from different resistivity models highlight a strong dependence on the starting model in the 3D inversions, but still enable us to put constraints on the deep structure of the craton. The present?day thermal lithosphere?asthenosphere boundary (LAB) depth is estimated to be at least 250 km beneath the Baoulé-Mossi domain. The area likely transitions from a cold and thick lithosphere with relatively low water content into thinner, more fertile lithosphere below the Volta Basin. Although the inferred amount of water could be explained by Paleoproterozoic subduction processes involved in the formation of the Baoulé-Mossi domain, later enrichment of the lithosphere cannot be excluded.
DS202110-1603
2021
Borenstein, G.Borenstein, G., Oneal, S.Rare mixed type IaB-IIb diamond with a long-lasting phosphorescence. Stuller's Gem Lab.Gems & Gemology, Vol. 57, 2, summer pp. 178-179. gia.edu/gems-gemologyUnited States, Louisiannaluminescence
DS202104-0590
2021
Borensztajin, S.Lv, M., Dorfman, S.M., Badro, J., Borensztajin, S., Greenberg, E., Prakapenka, V.B.Reversal of carbonate-silicate cation exchange in cold slabs in Earth's lower mantle. Nature Communications, doi.org/10.10.1038 /s41467-021-21761-9 8p. PdfMantlediamond inclusions

Abstract: The stable forms of carbon in Earth’s deep interior control storage and fluxes of carbon through the planet over geologic time, impacting the surface climate as well as carrying records of geologic processes in the form of diamond inclusions. However, current estimates of the distribution of carbon in Earth’s mantle are uncertain, due in part to limited understanding of the fate of carbonates through subduction, the main mechanism that transports carbon from Earth’s surface to its interior. Oxidized carbon carried by subduction has been found to reside in MgCO3 throughout much of the mantle. Experiments in this study demonstrate that at deep mantle conditions MgCO3 reacts with silicates to form CaCO3. In combination with previous work indicating that CaCO3 is more stable than MgCO3 under reducing conditions of Earth’s lowermost mantle, these observations allow us to predict that the signature of surface carbon reaching Earth’s lowermost mantle may include CaCO3.
DS201902-0258
2018
Borensztajn, S.Badro, J., Aubert, J., Hirose, K., Nomura, R., Blanchard, I., Borensztajn, S., Siebert, J.Magnesium partitioning between Earth's mantle and core and its potential to drive an early exsolution geodynamo.Geophysical Research Letters, Vol. 45, 24, pp. 13,240-13,248.Mantlegeodynamics

Abstract: We measure the incorporation of magnesium oxide (one of the main components of Earth's mantle) into iron (the main constituent Earth's core), using extremely high pressure and temperature experiments that mimic the conditions of Earth's mantle and core. We find that magnesium oxide dissolution depends on temperature but not on pressure, and on metal (i.e., core) composition but not silicate (i.e., mantle) composition. Our findings support the idea that magnesium oxide dissolved in the core during its formation will precipitate out during subsequent core cooling. The precipitation should stir the entire core to produce a magnetic field in Earth's distant past, at least as intense as the present?day field.
DS1995-2094
1995
Borevskiy, L.V.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
DS1996-0338
1996
BorgDavis, L.L., Smith, D., McDowell, F.W., Walker, N.W., BorgEocene potassic magmatism at Two Buttes, Colorado, with implications for Cenozoic tectonics and magma generationGeological Society of America (GSA) Bulletin., Vol. 108, No. 12, Dec. pp. 1567-1579.ColoradoAlkaline rocks, Tectonics
DS202007-1167
2020
Borg, G.Niegisch, M., Kamradt, A., Borg, G.Geochemical and mineralogical characterization of the REE mineralisation in the upper zone of the Storkwitz carbonatite complex from drill core SES-1/2012.Geopril, 15, 92p. PdfEurope, Germanydeposit - Storkwitz

Abstract: The Storkwitz-Carbonatite is a Late Cretaceous intru-sive complex, which is well-explored by a relatively large number of exploration bore holes both from the 1970ies, 1980ies and from one more recent bore hole, SES-1/2012. The carbonatite complex hosts a (cur-rently) marginally economic mineralisation of rare earth elements (REE) and niobium, which is technical-ly still difficult to recover. The upper part of the car-bonatitic body is located some 100-120 m below the Pre-Cenozoic land surface, which in turn is overlain by approximately 100 m of glacial, fluvio-glacial, and fluviatile sediments. The aim of this study was to characterize the minerali-sation in the upper part of the intrusion geochemically and mineralogically and to try to identify indications of a supergene overprint on the late magmatic to hydro-thermal mineralisation. Fresh drill core samples from the exploration bore hole SES-1/2012 have revealed that the mineralisation is associated with a carbonatit-ic igneous breccia body and also with several alvikite veins. The breccia body is very heterogeneous, dis-plays a variety of matrix colours and also a range of matrix-to-clast ratios. Non-destructive analytical methods like p-XRF anal-yses, magnetic susceptibility measurements, and SWIR-reflectance spectroscopy were carried out di-rectly on the drill core. The samples were also investi-gated by optical microscopy, scanning electron mi-croscopy (SEM) and their geochemical composition was analysed by whole rock analyses at a certified laboratory. The geochemical results confirm the presence of a REE-enriched zone, which is closely associated with the carbonatitic intrusion, whereas the porphyritic clasts of the breccia and the porphyritic wall rocks do not contain any REE mineralisation. The mineral composition of the examined sections is very hetero-geneous and comprises magmatic phenocrysts as well as a large variety of secondary mineral phases, which were formed by either hypogene, ascending late magmatic carbothermal or subsequent hydro-thermal processes or alternatively by deeply descend-ing meteoric supergene processes. The secondary processes were strongly oxidising and formed abun-dant hydrated mineral phases. The REE ore minerals are predominantly secondary monazites and REE-fluorocarbonates, which both occur in igneous breccias as well as in alvikite veins. Other minerals such as apatite or pyrochlore are slightly enriched in REE. However, there is no significant correlation be-tween the proportion of REE-bearing minerals ob-served microscopically and the geochemical REE concentration. Several mineral phases display intensive alteration textures and parageneses and especially the crypto-crystalline matrix of the breccias indicate a supergene influence. The supergene overprint has thus caused the alteration and formation of supergene Fe-oxyhydroxides and of an alumo-siliceous matrix and the local redistribution of the REE within the REE-mineral phases. However, no signs were detected that indicate a dissolution, transport, and especially frac-tionation of the dissolved REE in the (deep) super-gene environment.
DS1950-0259
1956
Borg, I.Y.Borg, I.Y.Glaucophane Schists and Eclogites Near Healdsburg, CaliforniGeological Society of America (GSA) Bulletin., Vol. 67, PP. 1563-1584.GlobalEclogite, Kimberlite
DS1997-0112
1997
Borg, L.E.Borg, L.E., Clynne, M.A., Bulletinen, T.D.The variable role of slab derived fluids in the generation of a suite of primitive calc alkaline lavasCanadian Mineralogist, Vol. 35, No. 2, April pp. 425-452.CaliforniaSubduction, tectonics, Alkaline related rocks
DS1997-0199
1997
Borg, L.E.Clynne, M.A., Borg, L.E.Olivine and chromian spinel in primitive calc alkaline and tholeiitic lavas from southernmost Cascade RangeCanadian Mineralogist, Vol. 35, No. 2, April pp. 453-472.CaliforniaSubduction, tectonics, Mantle fertility
DS1998-0141
1998
Borg, L.E.Borg, L.E., Clynne, M.A.The petrogenesis of felsic calc-alkaline magmas from the southernmostCascades: origin partial melting....Journal of Petrology, Vol. 39, No. 6, Jun. pp. 1197-1228.CaliforniaBasaltic lower crust, Magma - alkaline rocks
DS1994-0184
1994
Borg, S.G.Borg, S.G., DePaolo, D.J.Laurentia, Australia, and Antarctica as a late Proterozoic supercontinent:constraints from isotopic mappingGeology, Vol. 22, No. 4, April pp. 307-310United States, Australia, AntarcticaRecronics, geochronology, Supercontinent, Tectonics
DS2002-0330
2002
BorgesCosti, H.T., DallAgnol,R., Borges, Minuzzi, TeixeiraTin bearing sodic episyenites associated with the Proterozoic a type Agua granite, Pitinga mine.Gondwana Research, Vol.5,2,pp.435-52.Brazil, Amazon CratonTin, Deposit - Pitinga
DS201412-0059
2014
Borges, A.J.Borges, A.J.Caracteristicas magneticas dos kimberlitos da regiao do alto Paranaiba - Minas Gerais.6 Simposio Brasileiro de Geologia do Diamante, Aug. 3-7, 1p. AbstractSouth America, Brazil, BahiaGeophysics - magnetics
DS201112-0259
2010
Borges, F.M.de Sa Carneiro Chaves, M.L., Wanderson Andrade, K., Borges, F.M.Preservando a pedra rica (Grao Mogol, MG): primeira jazida de diamante minerada em rocha no mundo.5th Brasilian Symposium on Diamond Geology, Nov. 6-12, abstract p. 25-26.South America, Brazil, Minas GeraisBrief - history
DS201610-1846
2016
Borges, M.P.A.C.Borges, M.P.A.C., Moura, M.A., Lenharo, S.L.R., Smith, C.B., Araujo, D.P.Mineralogical characaterization of diamonds from Roosevelt Indigenous Reserve, Brazil, using non-destructive methods. Lithos, in press available 17p.South America, Brazil, RondoniaDeposit - Igarape Lajes Diggings

Abstract: In this study, 660 diamonds from Igarapé Lajes Diggings (Roosevelt and Aripuanã Park indigenous areas), in Amazonian craton, Rondônia State, Brazil, were investigated. Their morphological, optical and surface characteristics were described using optical and scanning electron microscopy (SEM), cathodoluminescence (CL) and infrared spectroscopy (FTIR). The results demonstrated a predominance of resorbed crystals with many surface corrosion features, generally colorless, and led to the identification of four distinct groups: G1, G2, G3 and G4. Group G1 presents features of secondary sources while G2 and G4 show only primary features, some of which are not described in literature. Group G3 is similar to the other groups, however, is composed of less resorbed specimens with primary octahedral morphology relatively well preserved, indicating shorter time of exposure to dissolution effects. Cathodoluminescence in G2 is attributed to features of plastic deformation and to low contents of nitrogen (< 100 ppm, Type II) and high aggregation (IaB). G4 shows homogeneous blue CL, high contents of nitrogen (700 to 1000 ppm) and intermediate aggregation (IaAB). G1 presents luminescence influenced by radiation effects and populations with N contents and aggregation in the same ranges of G2 and G4, suggesting that the primary sources of the three groups can be the same. The relationship of nitrogen content versus aggregation state indicates higher temperatures of formation for G2 and lower for G4. The obtained data suggests that diamonds of G2 originated in sublithospheric mantle as has also been reported in nearby deposits (Machado River and Juína). The employed techniques were also effective in distinguishing diamonds from Roosevelt Reserve and from other localities, indicating that they could be used for improvement of certification procedures of diamonds of unknown origin.
DS201412-0728
2014
Borges, W.R.Rego, F.M., Cunha, L.M., Silveira, F.V., Borges, W.R.Caracterizacao geoleltrica de aluvioes diamantiferos no Rio Santo Inacio - Coromandel, M.G.6 Simposio Brasileiro de Geologia do Diamante, Aug. 3-7, 4p. AbstractSouth America, Brazil, Minas GeraisCoromandel geophysics
DS202110-1608
2021
Borges Bernardes, R.da Silva, G.F., Ferreira, M., Costa, I., Borges Bernardes, R.Qmin: A machine learning-based application for mineral chemistry data processing and analysis. * note not specific to diamonds.Researchgate Preprint, 23p. PdfGlobalmineralogy

Abstract: Mineral chemistry analysis is a valuable tool in several phases of mineralogy and mineral prospecting studies. This type of analysis can point out relevant information, such as concentration of the chemical element of interest in the analyzed phase and, thus, the predisposition of an area for a given commodity. Due to this, considerable amount of data has been generated, especially with the use of electron probe micro-analyzers (EPMA), either in research for academic purposes or in a typical prospecting campaign in the mineral industry. We have identified an efficiency gap when manually processing and analyzing mineral chemistry data, and thus, we envisage this research niche could benefit from the versatility brought by machine learning algorithms. In this paper, we present Qmin, an application that assists in increasing the efficiency of mineral chemistry data processing and analysis stages through automated routines. Our code benefits from a hierarchical structure of classifiers and regressors trained by a Random Forest algorithm developed on a filtered training database extracted from the GEOROC (Geochemistry of Rocks of the Oceans and Continents) repository, maintained by the Max Planck Institute for Chemistry. To test the robustness of our application, we applied a blind test with more than 11,000 mineral chemistry analyses compiled for diamond prospecting within the scope of the Diamante Brasil Project of the Geological Survey of Brazil. The blind test yielded a balanced classifier accuracy of ca. 99% for the minerals known by Qmin. Therefore, we highlight the potential of machine learning techniques in assisting the processing and analysis of mineral chemistry data.
DS201810-2298
2018
Borghini, G.Borghini, G., Fumagalli, P.Subsolidus phase relations in a mantle pyroxenite: an experimental study from 0.7 to 1.5 Gpa.European Journal of Mineralogy, Vol. 30, 2, pp. 333-348.Mantlepyroxenite

Abstract: Pyroxenites are a diffuse heterogeneity in the upper mantle and represent key lithologies in melting processes and mantle deformation. Mantle peridotites exposed in ultramafic massifs are commonly veined by pyroxenites. The latter experienced the same metamorphic evolution as host peridotite and may develop substantially different phase assemblages in response to the different bulk composition. Although several experimental studies focused on melting relations in pyroxenites, subsolidus phase relations are still poorly known. We provide new experimental constraints on phase stability and mineral chemistry for a natural mantle pyroxenite. Piston-cylinder experiments were conducted from 0.7 to 1.5?GPa, 1100-1250?°C. Al-rich spinel, clinopyroxene, orthopyroxene and olivine are ubiquitous phases within the whole pressure range investigated. At 1100?°C, plagioclase is stable up to 0.9?GPa; anorthite content [An?=?Ca/(Ca?+?Na)] decreases as a function of pressure from 0.70 at 0.7?GPa to 0.61 at 0.9?GPa. Maximum plagioclase modal abundance of 14?wt% forms at 0.7?GPa; this amount is more than twice as experimentally determined at the same P-T conditions in fertile lherzolite (5-6?wt%). At intermediate pressure (1.0-1.4?GPa), modal spinel is almost constant (4-5?wt%). A pyrope-rich garnet is stable at 1.5?GPa and its modal abundance increases from 5 to 10 wt% when temperature decreases from 1230?°C to 1150?°C, from 1230?°C to 1150?°C. The Al content in pyroxenes varies significantly across the plagioclase-out and garnet-in transitions and is not pressure-dependent in the spinel-pyroxenite field. At 1100?°C, the plagioclase-out boundary occurs at comparable pressures in the pyroxenite and in fertile lherzolites. On the contrary, the garnet-in curve is located at significantly lower pressure than for mantle peridotites.
DS2000-0099
2000
Borgia, A.Borgia, A., Delaney, P.T., Denlinger, R.P.Spreading volcanoesAnnual Review Earth Plan. Sci., Vol. 28, pp.539-70.Mantlevolcanism - not specific to diamonds
DS1993-1241
1993
BorianiPinarelli, L., Boriani, Del Moro, A.The lead isotope systematics during crustal contamination of subcrustalmagmas: the Hercynian magmatism in the Serie dei Laghi Southern Alps, ItalyLithos, Vol. 31, pp. 51-61ItalyDikes, Magmas
DS1987-0387
1987
Borimchuk, N.I.Kurdyumov, A.V., Borimchuk, N.I.Transformation mechanism of rhombohedral graphite into diamond. (Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 297, No. 3, pp. 602-604RussiaBlank
DS1985-0001
1985
Boris, E.I.Afanasev, V.P., Zinchuk, N.N., Boris, E.I.Characteristics of concentration of a kimberlite material inancient sedimentary deposits of Yakutia. (in Russian)Rudn. Spets. Osad. Form. Sib. Dalnego Vostoka, (in Russian), pp. 129-133RussiaBlank
DS1985-0767
1985
Boris, E.I.Zinchuk, N.N., Kotelnikov, D.D., Boris, E.I., Faintsyen, G.KH.Ancient Weathered Crusts and Prospecting for Diamond DepositsBook Review in Soviet Geology and Geophysics, Vol. 26, No. 8, pp. 119-121RussiaBlank
DS1990-0222
1990
Boris, E.I.Boris, E.I., Rotman, A.Ya., Serenko, V.P.Time of occurrence of vent facies of basite volcanism within BotuobiyaupliftSoviet Geology and Geophysics, Vol. 31, No. 7, pp. 48-53RussiaBasite, Tectonics
DS1994-1999
1994
Boris, E.I.Zinchuk, N.N., Boris, E.I.Formations of buried weathering crusts and resedimentation with the search of kimberlites.Russian Acad. of Sciences, Placers and weathered rock, Nov. 2p.Russia, YakutiaDiamonds, Placers, alluvials
DS1995-0169
1995
Boris, E.I.Bondarenko, A.T., Boris, E.I., Stogova, V.A.Lateral variation of electrical properties of kimberlite hosting sedimentary rocks of western YakutiaRussian Geology and Geophysics, Vol. 36, No. 3, pp. 113-119.Russia, YakutiaGeophysics, Deposit -Malo-Botuoba
DS1995-0325
1995
Boris, E.I.Chyornaya, T.A., Boris, E.I.Subdivision of upper Paleozoic productive deposits, the Tungus synecliseProceedings of the Sixth International Kimberlite Conference Almazy Rossii Sakha abstract, p. 9.Russia, YakutiaOrganics, Tungus syneclise
DS1995-0435
1995
Boris, E.I.Doukardt, Yu.A., Boris, E.I.Structural formational and morphological regionalization of the Siberian Platform basement:Proceedings of the Sixth International Kimberlite Conference Almazy Rossii Sakha abstract, p. 24.Russia, YakutiaTectonics, Craton
DS1983-0324
1983
Boris, Y.I.Ivankin, P.F., Argunov, K.P., Boris, Y.I.Evolution of the Formation Conditions of Diamonds in Kimberlites.(russian)Sov. Geol., (Russian), No. 9, pp. 30-38RussiaDiamond Morphology
DS1985-0549
1985
Boris, Y.I.Prokopchuk, B.I., Argunov, K.P., Boris, Y.I., Zazhardova, V.R.Seperation of Diamonds in Placer Deposits. (russian)Soviet Geology, (Russian), No. 3, pp. 43-57RussiaPlacers
DS1998-1642
1998
Boris, Y.I.Zinchouk, N.N., Boris, Y.I.Erosional section of kimberlite bodies and the scales of placerdiamondiferousness.7th International Kimberlite Conference Abstract, pp. 1013-6.Russia, YakutiaMineral chemistry, weathering, Alluvial
DS1998-1643
1998
Boris, Y.I.Zinchouk, N.N., Boris, Y.I., Stegnitsky, Y.B.Specific features of kimberlite prospecting in various Lands cape geologicalconditions.7th International Kimberlite Conference Abstract, pp. 1017-9.Russia, Siberia, YakutiaMineral chemistry, weathering, Prospecting
DS1998-1644
1998
Boris, Y.I.Zinchouk, N.N., Dukardt, Y.A., Boris, Y.I.Specific features of zoning of ancient platforms' territories according To the degree of perspectiveness7th International Kimberlite Conference Abstract, pp. 1020-23.Russia, Siberia, YakutiaTectonic metamorphic stages, Craton
DS1998-1645
1998
Boris, Y.I.Zinchouk, N.N., Koptil, V.I., Boris, Y.I.Ancient platforms' diamond typomorphism (on the example of SiberianPlatform).7th International Kimberlite Conference Abstract, pp. 1024-7.Russia, Siberia, YakutiaDiamond morphology
DS1992-0144
1992
Boris, Ye. I.Boris, Ye. I., Frantsesson, Ye.V.Regularities of localization of kimberlite bodies in Malo-BoTo bin region, westerm Yakutia. (Russian)Izvestiya Vysshikh Uch. Zaved., (Russian), No. 5, pp. 68-75.Russia, YakutiaStructure, Deposit -Mir
DS1985-0304
1985
Boris, YE.I.Ivankin, P.F., Argunov, K.P., Boris, YE.I.Changing Environments of Diamond Formation in KimberlitesInternational Geology Review, Vol. 26, No. 7, PP. 795-802.RussiaGenesis
DS1988-0321
1988
Boris, Ye.I.Ivankin, P.F., Argunov, K.P., Boris, Ye.I.Stages of kimberlite development and evolving conditions of diamondformationInternational Geology Review, Vol. 30, no, . 3, March pp. 268-274RussiaDiamond morphology, Diamond genesis
DS1988-0350
1988
Boris, Ye.I.Kharkiv, A.D., Boris, Ye.I., Shabo, Z.V., Mamchur, G.P., SheremeyevThe occurrence of oil in the eruptive pipes of theSiberianPlatform*(in Russian)Geologii i Geofiziki, (Russian), No. 4, pp. 60-70RussiaStructural geology, Tectonics
DS201412-0952
2014
Borisenko, A.S.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
DS201610-1901
2016
Borisenko, A.S.Prokopyev, I.R., Borisenko, A.S., Borovikov, A.A., Pavlova, G.G.Origin of REE rich ferrocarbonatites in southern Siberia ( Russia): implications based on melt and fluid inclusions.Mineralogy and Petrology, in press available 15p.Russia, Kola PeninsulaDeposit - Tuva

Abstract: Fe-rich carbonatites with a mineral assemblage of ankerite-calcite or siderite are widespread in southern Siberia, Russia. The siderite carbonatites are associated with F-Ba-Sr-REE mineralization and have a 40Ar/39Ar age of 117.2 ± 1.3 Ma. Melt and fluid inclusions suggest that the carbonatites formed from volatile-rich alkali- and chloride-bearing carbonate melts. Ankerite-calcite carbonatites formed from carbonatite melt at a temperature of more than 790 °C. The ferrocarbonatites (the second phase of carbonatite intrusion) formed from a sulfate-carbonate-chloride fluid phase (brine-melt) at >650 °C and ?360 MPa. The brine-melt fluid phase had high concentrations of Fe and LREEs. A subsequent hydrothermal overprint contributed to the formation of economically important barite-Sr-fluorite-REE mineralization in polymict siderite breccia.
DS201701-0028
2016
Borisenko, A.S.Prokopyev, I.R., Borisenko, A.S., Borovikov, A.A., Pavlova, G.G.Origin of REE rich ferrocarbonatites in southern Siberia ( Russia): implications based on melt and fluid inclusions.Mineralogy and Petrology, Vol. 110, pp. 845-859.Russia, SiberiaCarbonatite

Abstract: Fe-rich carbonatites with a mineral assemblage of ankerite-calcite or siderite are widespread in southern Siberia, Russia. The siderite carbonatites are associated with F-Ba-Sr-REE mineralization and have a 40Ar/39Ar age of 117.2 ± 1.3 Ma. Melt and fluid inclusions suggest that the carbonatites formed from volatile-rich alkali- and chloride-bearing carbonate melts. Ankerite-calcite carbonatites formed from carbonatite melt at a temperature of more than 790 °C. The ferrocarbonatites (the second phase of carbonatite intrusion) formed from a sulfate-carbonate-chloride fluid phase (brine-melt) at >650 °C and ?360 MPa. The brine-melt fluid phase had high concentrations of Fe and LREEs. A subsequent hydrothermal overprint contributed to the formation of economically important barite-Sr-fluorite-REE mineralization in polymict siderite breccia.
DS1981-0092
1981
Borisenko, L.F.Borisenko, L.F., Ovcharenko, V.K.Some Properties of Ilmenite in Igneous RocksDoklady Academy of Science USSR, Earth Science Section., Vol. 247, No. 1-6, PP. 134-137.RussiaMineralogy
DS1995-0170
1995
Boriskenko, L.F.Boriskenko, L.F., Polikashina, N.S.Titanium in weathering crusts and related alluvial placersLithology and Mineral resources, No. 1, pp. 46-54Russia, UkraineAlluvials, Laterites
DS1995-1391
1995
Borisov, A.O'Neill, H. St. C., Dingwell, D.B., Borisov, A., SpettelExperimental petrochemistry of some highly siderophile elements at hightemperatures, core formation mantle.Chemical Geology, Vol. 120, No. 3-4, March 1, pp. 255-273.MantleGeochemistry
DS1998-1107
1998
Borisov, A.Palme, H., Borisov, A., Holzheid, SchmidtOrigin and significance of highly siderophile elements in the upper mantle of the earth.Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1127-8.MantleHSE silicate melts
DS1985-0073
1985
Borisov, A.B.Borisov, A.B.Some features of mineralogy and genesis of benstonite carbonatites of the Murunsky massif.(Russian)Vestnik Lenin. University of Ser. Geol., (Russian), Vol. 21, pp. 97-102RussiaCarbonatite, Mineralogy
DS1990-1337
1990
Borisov, A.B.Shadenkov, Ye.M., Orlova, M.P., Borisov, A.B.Pyroxenite and shonkinite of the Malyy Murun pluton-intrusive analogs oflamproiteInternational Geology Review, Vol. 32, No. 1, January pp. 61-69RussiaLamproite/shonkinite, Malyy Murun
DS1992-1150
1992
Borisov, A.B.Orlova, M.P., Borisov, A.B., Shadenkov, E.M.Alkaline magmatism of the Murun areal. (Aldan Shield)Russian Geology and Geophysics, Vol. 33, No. 5, pp. 45-55.Russia, Aldan shieldAlkaline rocks
DS1995-1401
1995
Borisov, A.B.Orlova, M.P., Borisov, A.B., Orlov, D.M.Russian lamproites: the International Geological Correlation Programme (IGCP) -314 projectGeochemistry International, Vol. 32, No. 12, Dec. pp. 22-33.RussiaLamproites, Petrology
DS1995-1402
1995
Borisov, A.B.Orlova, M.P., Lukjanova, L., Borisov, A.B., et al.Lamproites of Russia ( geology, mineralogy, petrochemistry, geochemistry)Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 410-412.Russia, Karelia, Witesea Onegskaja, Urals, Taimyr, OlenekSajan, Aldan, Sette Daban, Lamproites
DS1995-0171
1995
Borisov, V.N.Borisov, V.N., Alexeev, S.V., Pleshevenkova, V.A.The diamond mining quarries of East Siberia as a factor affecting surficial water quality.Gems and gemology, Gemological Abstracts, Vol. 32, Winter, p. 298.Russia, SiberiaMining, Diamond
DS2002-0189
2002
Borisova, A.Y.Borisova, A.Y., Nikogosian, Scoates, Weis, DamascenoMelt, fluid inclusion and crystal inclusions in olivine phenocrysts - Kerguelen plume derived picritic basaltsChemical Geology, Vol.183,1-4,pp.195-220.Kerguelen IslandsLithosphere - picrites, Geochemistry
DS201709-1962
2017
Borisova, A.Y.Borisova, A.Y., Zagrtdenov, N.R., Toplis, M.J., Bohrson, W.A., Nedelec, A., Safonov, O.G., Pokrovski, G.S., Ceileneer, G., Melnik, O.E., Bychkov, A.Y., Gurenko, A.A., Shscheka, S., Terehin, A., Polukeev, V.M., Varlamov, D.A., Gouy, S., De Parseval, P.Making Earth's continental crust from serpentinite and basalt. Goldschmidt Conference, abstract 1p.Mantleperidotites

Abstract: How the Earth's continental crust was formed in the Hadean eon is a subject of considerable debates [1-4]. For example, shallow hydrous peridotites [2,5], in particular the Hadean Earth's serpentinites [6], are potentially important ingredients in the creation of the continental ptoto-crust, but the mechanisms of this formation remain elusive. In this work, experiments to explore serpentinite-basalt interaction under conditions of the Hadean Earth were conducted. Kinetic runs lasting 0.5 to 48 hours at 0.2 to 1.0 GPa and 1250 to 1300°C reveal dehydration of serpentinite and release of a Si-Al-Na-K-rich aqueous fluid. For the first time, generation of heterogeneous hydrous silicic melts (56 to 67 wt% SiO2) in response to the fluid-assisted fertilisation and the subsequent partial melting of the dehydrated serpentinite has been discovered. The melts produced at 0.2 GPa have compositions similar to those of the bulk continental crust [2,3]. These new findings imply that the Earth's sialic proto-crust may be generated via fluid-assisted melting of serpentinized peridotite at shallow depths (?7 km) that do not require plate subduction during the Hadean eon. Shallow serpentinite dehydration and melting may be the principal physico-chemical processes affecting the earliest lithosphere. Making Earth's continental crust from serpentinite and basalt.
DS202012-2206
2020
Borisova, A.Y.Borisova, A.Y., Bindeman, I.N., Toplis, M.J., Zagrtdenov, N.R., Guignard, J., Safonov, O.G., Bychkov, A.Y., Shcheka, S., Melnik, O.E., Marcelli, M., Fehrenbach, J.Zircon survival in shallow asthenosphere and deep lithosphere.American Mineralogist, Vol. 105, pp. 1662-1671. pdfMantlemelting

Abstract: Zircon is the most frequently used mineral for dating terrestrial and extraterrestrial rocks. However, the system of zircon in mafic/ultramafic melts has been rarely explored experimentally and most existing models based on the felsic, intermediate and/or synthetic systems are probably not applicable for prediction of zircon survival in terrestrial shallow asthenosphere. In order to determine the zircon stability in such natural systems, we have performed high-temperature experiments of zircon dissolution in natural mid-ocean ridge basaltic and synthetic haplobasaltic melts coupled with in situ electron probe microanalyses of the experimental products at high current. Taking into account the secondary fluorescence effect in zircon glass pairs during electron microprobe analysis, we have calculated zirconium diffusion coefficient necessary to predict zircon survival in asthenospheric melts of tholeiitic basalt composition. The data imply that typical 100 micron zircons dissolve rapidly (in 10 hours) and congruently upon the reaction with basaltic melt at mantle pressures. We observed incongruent (to crystal ZrO2 and SiO2 in melt) dissolution of zircon in natural mid-ocean ridge basaltic melt at low pressures and in haplobasaltic melt at elevated pressure. Our experimental data raise questions about the origin of zircons in mafic and ultramafic rocks, in particular, in shallow oceanic asthenosphere and deep lithosphere, as well as the meaning of the zircon-based ages estimated from the composition of these minerals. Large size zircon megacrysts in kimberlites, peridotites, alkali basalts and other magmas suggest the fast transport and short interaction between zircon and melt.The origin of zircon megacrysts is likely related to metasomatic addition of Zr into mantle as any mantle melting episode should obliterate them.
DS202203-0337
2022
Borisova, A.Y.Borisova, A.Y., Nedelec, A.A simple recipe for making the first continental crust. EOS.org, Feb. 2p.Mantleexperiments

Abstract: Earth’s continental crust, on which billions of people and countless land animals and plants spend their lives, is distinguished by its predominantly felsic composition. That is, this crust contains large proportions of silicon, oxygen, aluminum, and alkali metals like sodium and potassium, and it is largely made up of quartz and feldspar minerals. Felsic continental crust as old as 4 billion years has been recognized on Earth’s surface, and we know it was associated with basaltic oceanic crust made of minerals rich in calcium, magnesium, and iron, such as plagioclase feldspar, olivine, and pyroxenes. But the planet’s earliest rigid outer shell-its primordial crust, which crystallized from the magma ocean covering the nascent Earth about 4.5 billion years ago-probably looked very different. When and how the first felsic crust formed are questions researchers have pondered for decades. Unfortunately, a handful of microscopic zircons, accessory minerals commonly found in felsic rocks, from a few places around the world are the only remnants from the Hadean eon, the first 500 million years of Earth’s existence. In the almost complete absence of early crustal rocks, scientists have thus had to piece together their hypotheses from indirect evidence. Recently, our research group completed laboratory experiments and numerical modeling that revealed evidence of a felsic rock-forming reaction that may have occurred on Hadean Earth and may have been responsible for creating the planet’s first continental crust.-
DS1995-0172
1995
Borisova, E.Y.Borisova, E.Y., Bibikova, E.V., Dobrozhev, L.F.The geochronological study of the granite gneiss zircon of the Kokchetav diamond bearing region. (Russian)Doklady Academy of Sciences Nauk., (Russian), Vol. 343, No. 6, Aug. pp. 801-5. #R2010RussiaGeochronology, Deposit -Kokchetav region
DS1985-0152
1985
Borisova, V.V.Douchaeva, V.S., Borisova, V.V.Geochemistry of Basic Ultrabasic Magmatism of the Kola Peninsula.(russian)Petrol. Kriter. Otsenki Rudn. Dokembr., (Russian), Akad. Nauk SSSR Publishing, pp. 51-64RussiaWebsterite, Harzburgite, Lherzolite
DS2001-0389
2001
Borisovskii, S.E.Glukhovskii, M.Z., Moralev, V.M., Borisovskii, S.E.Zirconium and hafnium in zircons from Archean enderbites of Sunnagin dome, evolution of ancient crustDoklady, Vol.381A,No.9, Nov-Dec. pp. 1088-91.Russia, Aldan shieldPetrology
DS201507-0333
2015
Borisovskiy, S.E.Sazonova, L.V., Nosova, A.A., Kargin, A.V., Borisovskiy, S.E., Tretyachenko, V.V., Abazova, Z.M., Griban, Yu.G.Olivine from the Pionerskaya and V. Grib kimberlite pipes, Arkangelsk diamond province, Russia: types, composition, and origin.Petrology, Vol. 23, 3, pp. 227-258.RussiaDeposit - Grib
DS201412-0443
2014
Borisovsky, S.Kargin, A., Nosova, A., Larionova, Yu., Kononova, V., Borisovsky, S., Kovalchuk, E., Griboedova, I.Mesoproterozoic orangeites ( Kimberlites II) of west Karelia: mineralogy, geochemistry and Sr-Nd isotope composition.Petrology, Vol. 22, 2, pp. 151-183.RussiaOrangeites
DS1970-0634
1973
Borley, G.D.Borley, G.D., Suddaby, P.Pyroxenite Xenoliths from the Kimberlite of Jagersfontein Mine1st International Kimberlite Conference, EXTENDED ABSTRACT VOLUME, PP. 39-41.South AfricaPetrography
DS1975-0035
1975
Borley, G.D.Borley, G.D.Mantle Deformation Beneath the South African and Siberian Platforms.Nature., Vol. 254, No. 5500, PP. 489-491.South Africa, RussiaTectonics
DS1975-0036
1975
Borley, G.D.Borley, G.D., Suddaby, P.Stressed Pyroxenite Nodules from the Jagersfontein KimberlitMineralogical Magazine., Vol. 40, No. 309, PP. 6-12.South AfricaPetrography, Xenoliths
DS202001-0044
2019
Borlina, C.S.Tang, F., Taylor, R.J.M., Einsle, J.F., Borlina, C.S., Fu, R.R., Weiss, B.P., Williams, H.M., Williams, W., Nagy, L., Midgley, P.A., Lima, E.A., Bell, E.A., Harrison, T.M., Alexander, E.W., Harrison, R.J.Secondary magnetite in ancient zircon precludes analysis of a Hadean geodynamo. Jack HillsProceedings National Academy of Science, Vol. 116, pp. 407-412.Australiapaleomagnetism

Abstract: Zircon crystals from the Jack Hills, Western Australia, are one of the few surviving mineralogical records of Earth’s first 500 million years and have been proposed to contain a paleomagnetic record of the Hadean geodynamo. A prerequisite for the preservation of Hadean magnetization is the presence of primary magnetic inclusions within pristine igneous zircon. To date no images of the magnetic recorders within ancient zircon have been presented. Here we use high-resolution transmission electron microscopy to demonstrate that all observed inclusions are secondary features formed via two distinct mechanisms. Magnetite is produced via a pipe-diffusion mechanism whereby iron diffuses into radiation-damaged zircon along the cores of dislocations and is precipitated inside nanopores and also during low-temperature recrystallization of radiation-damaged zircon in the presence of an aqueous fluid. Although these magnetites can be recognized as secondary using transmission electron microscopy, they otherwise occur in regions that are indistinguishable from pristine igneous zircon and carry remanent magnetization that postdates the crystallization age by at least several hundred million years. Without microscopic evidence ruling out secondary magnetite, the paleomagnetic case for a Hadean-Eoarchean geodynamo cannot yet been made.
DS201112-0950
2011
BormotovShestakov, N.V., Gerasimenko, Takalhashi, Tasahara, Bormotov, Bykov,Kolomiets et al.Present tectonics of the southeast of Russia as seen from GPS observations.Geophysical Journal International, Vol. 184, 2, pp. 529-540.RussiaGeodynamics
DS1920-0430
1929
Born, A.Born, A.Ueber Atektonische Faltung Bei Kimberley, SuedafrikasZeitschr. Deut. Geol. Ges., Vol. 81, No. 10, PP. 540-541.South Africa, Griqualand West, Kimberley AreaStructure
DS1989-0144
1989
Born, H.Born, H.The Jacupiranga apatite deposit, Sao Paulo BrasilPhosphate deposits of the World, Vol. 2, pp. 111-115BrazilApatite, Carbonatite
DS1997-0025
1997
Born, H.Amaral, G., Born, H., Tello, S.C.A.Fission track analysis of apatites from Sao Francisco craton and Mesozoic alkaline - carbonatite complexes...Journal of South American Earth Sciences, Vol. 10, No. 3-4, pp. 285-294.Brazil, southeastCarbonatite
DS1930-0291
1939
Born, K.E.Born, K.E., Wilson, C.W.Je.The Howell Structure, Lincoln County, TennesseeJournal of Geology, Vol. 47, No. 4, PP. 371-386.United States, Central States, Western TennesseeCryptoexplosion
DS1940-0146
1947
Born, M.Born, M., Bradburn, M.The Theory of the Raman Effect in Crystals in Particular Rock SaltProceedings of the Royal Society, Vol. 188, Series A, Mathematical and Physical Sciences, .GlobalBlank
DS1930-0233
1936
Born, R.E.Wilson, C.W.JR., Born, R.E.The Flynn Creek Disturbance, Jackson County, TenneseeJournal of Geology, Vol. 44, No. 7, PP. 815-835.GlobalKimberlite, Western Tennessee, Central States, Cryptoexplosion
DS1950-0323
1957
Borneo Geological SurveyBorneo Geological SurveySketch Map Showing the Geology of BorneoBorneo Geological Survey, 1: 2, 000, 000BorneoGeology, Map
DS1987-0560
1987
Bornhorst, T.J.Paces, J.B., Bornhorst, T.J.Geochemical constraints on tectonic models of late stagemidcontinentrifting: Portage Lake volcanics, MichiganGeological Society of America, Vol. 19, No. 4, March p. 237-238. (abstract)MichiganUSA, Geochemistry
DS1987-0790
1987
Bornhorst, T.J.Whitten, T.E.H., Bornhorst, T.J., Gongshi Li, Hicks, D.L., BeckwithSuites, subdivision of batholiths and igneous rock classification:geological and mathematical conceptualizationAmerican Journal of Science, Vol. 287, April pp. 332-352GlobalClassification, Igneous rocks
DS1989-0355
1989
Bornhorst, T.J.Dickas, A.B., Bornhorst, T.J., Ojakangas, R.W., Green, J.C.Lake Superior basin segment of the Midcontinent rift systemAmerican Geophysical Union (AGU) 28th. International Geological Congress Field Trip Guidebook, No. T 344, 62pMidcontinentTectonics
DS201609-1704
2010
Bornman, F.Bornman, F.Letseng mine no. 2 plant project - a process engineering and design review.The 4th Colloquium on Diamonds - source to use held Gabarone March 1-3, 2010, 14p.Africa, LesothoDeposit - Letseng

Abstract: Bateman Engineering managed the establishment of a second diamond treatment plant at the Letseng Mine in the Mokhotlong District of northern Lesotho, about 100 km from the town of Buthe Buthe. Letseng Diamonds Proprietary Limited, is owned 70 % by Gem Diamonds and 30 % by the Government of the Kingdom of Lesotho. The second plant, which commenced construction in late 2006, doubled Letseng Mines' hard rock processing capacity from 2.6 million t/yr to 5.2 million t/yr, making it the worlds' seventh largest diamond mine by throughput. Bateman Engineering provided the engineering design, procurement and construction management of the new plant.
DS201609-1734
2010
Bornman, F.Olivier, D., Bornman, F., Roode, L., Acker, A.Finsch mine treatment plant upgrade project.The 4th Colloquium on Diamonds - source to use held Gabarone March 1-3, 2010, 14p.Africa, South AfricaDeposit - Finsch

Abstract: De Beers' Finsch Mine is situated in the Northern Cape ,province, 170 km northwest of Kimberley. The concentrator facility, designed and constructed by Bateman Engineering, was commissioned in 1967 and upgraded in 1979 using diamond liberation and extraction technology available at the time of design. Since then significant advances in diamond processing and technology have been made and these -have been incorporated into the new main treatment plant and recovery plant flowsheets, making diamond liberation and recovery from the Pre-1979 dumps a viable economic option at Finsch." Significant challenges were experienced as a result of the integration of new technology and its associated infrastructure into an existing plant. Major process flow changes were implemented during the execution phase of the project. The combined effect of these issues resulted in the project being overspent by 25% and the final handover to the Client was some 18 months later than originally planned." The paper highlights some of the difficulties experienced as a result of changes made during the execution phases of the project.
DS200412-1246
2004
Bornyakov, S.A.Matrosov, V.A., Bornyakov, S.A., Gladkov, A.S.A new approach to optimization of prognostic prospecting for Diamondiferous kimberlites.Doklady Earth Sciences, Vol. 395, 2, pp. 192-195.RussiaDiamond prospecting technique
DS200512-0344
2005
Bornyakov, S.A.Gladkov, A.S., Zinchuk, N.N, Bornyakov, S.A., Sherman, S.I., Manakov, A.V., Matrosov, V.A., Garat, DzyubaNew dat a on the internal structure and formation mechanism of kimberlite hosting fault zones in the Malaya Botuoba region, Yakutian Diamondiferous provinceDoklady Earth Sciences, Vol. 402, 4, pp. 520-23.Russia, YakutiaTectonics, structure, Malaya Botuoba
DS201012-0237
2010
Bornyakov, S.A.Gladkov, A.S., Makovchuk, I.V., Lunina, O.V., Bornyakov, S.A., Potekhina, I.A.The Yubieinaya kimberlite pipe site, Russia: 3 D model of the fault block structure.Geology of Ore Deposits, Vol. 52, 3, pp. 234-251.RussiaStructure
DS201705-0810
2016
Bornyakov, S.A.Bornyakov, S.A., Salko, D.V.Instrumental deformation monitoring system and its trial in open pit diamond mine.Journal of Mining Science, Vol. 52, 2, pp. 388-393.RussiaDeposit - Nyurbisnskaya

Abstract: The designed automated system for pitwall deformation monitoring consists of an independent data recorder, strain sensors, AD converters, and front-end and back-end controls. Data are accumulated on server in on-line mode via cellular modem. The self-contained tools are supplied from accumulators recharged by solar batteries, which expands operational life of the system. The system has been trailed in an open pit mine at Nyurbinskaya kimberlite pipe in deformation monitoring of faults in the eastern pitwall and estimation of its stability.
DS1985-0031
1985
Borobev, S.A.Babadzha, R.D., Borobev, S.A., Kalinin, B.N., Mun, V.V.Effect of Supressing the Outcome of the Ultrarelativistic Electron X-ray Diffraction Radiation in Diamonds.Zhurn. Tekh. Fiz., Vol. 55, No. 8, PP. 1645-1646.RussiaDiamond Refraction
DS1982-0611
1982
Borodaev, YU.Ukhanov, A.V., Borodaeva, T.YU., Borodaev, YU.Composition and Zonality of Olivines from the Udachnaya Pipe As a Refl Ection of Path of the Kimberlite Magma Evolution.Geochemistry International (Geokhimiya)., No. 5, MAY PP. 664-676.RussiaKimberlite Genesis
DS1982-0611
1982
Borodaeva, T.YU.Ukhanov, A.V., Borodaeva, T.YU., Borodaev, YU.Composition and Zonality of Olivines from the Udachnaya Pipe As a Refl Ection of Path of the Kimberlite Magma Evolution.Geochemistry International (Geokhimiya)., No. 5, MAY PP. 664-676.RussiaKimberlite Genesis
DS1970-0247
1971
Borodin, L.S.Borodin, L.S., Gopal, V., Moralev, V.M., Suramanian, V., PonikarPrecambrian Carbonatites of Tamil Nadu, South IndiaGeological Society INDIA Journal, Vol. 12, No. 2, PP. 101-112.India, Tamil NaduPetrography, Analyses
DS1975-0248
1976
Borodin, L.S.Borodin, L.S.Petrologiya I Geochemistry International (geokhimiya) Daek Shcholochno- Ultraosnovnykh Porod I Kimberlitov.Moscow., XEROX.RussiaKimberlite, Kimberley, Janlib
DS1975-0697
1978
Borodin, L.S.Borodin, L.S.Alkaline Ultramafic and Carbonatite Provinces of the UssrI Symposio International De Carbonatitos, PP. 223-226.RussiaPetrology, Karelia, Kola, Maimecha, Kotui
DS1975-0698
1978
Borodin, L.S.Borodin, L.S., Pyatenko, I.K.General Petrological Aspects of Paleozoic Alkali Magmatism In the Kola Peninsula and the Rare Earth Distribution in Alkali Ultrabasic Lamprophyre Dikes.Geochemistry International (Geokhimiya), Vol. 15, No. 3, PP. 124-135.Russia, Kola PeninsulaPetrology
DS1994-0185
1994
Borodin, L.S.Borodin, L.S.Petrochemical trends and evolution of the Archean continental crustGeochemistry International, Vol. 31, No. 8, pp. 41-56RussiaGeochemistry, Archean crust
DS1995-0173
1995
Borodin, L.S.Borodin, L.S.Genetic types and geochemical features of mantle crustal carbonatiteassociation.Geochemistry International, Vol. 32, No. 7, pp. 107-117.RussiaCarbonatite
DS1999-0081
1999
Borodin, L.S.Borodin, L.S.Estimation chemical composition and petrochemical evolution of the Upper Continental crust.Geochemistry International, Vol. 37, No. 8, Aug. pp. 723-34.MantleGeochemistry, Crust
DS202201-0040
2021
Borodyna, B.V.Shumlyanskyy, L., Kamenetsky, V.S., Borodyna, B.V.Age and composition of zircons from the Devonian Petrivske kimberlite pipe of the Azov domain, the Ukrainian shield.Mineralogical Journal, Dec.Asia, Ukrainedeposit - Petrivske

Abstract: Zircon megacrysts are commonly found in kimberlites and, together with olivine, low-Cr garnet, pyroxene, phlogopite, and ilmenite megacrysts, they constitute a mineral assemblage known as the “low-Cr suite”. The generally close similarity of ages and similar isotope geochemical characteristics of megacrysts and matrix minerals in the host kimberlites support a cognate origin. However, alteration rims commonly develop on zircon and ilmenite megacrysts, providing evidence for a lack of chemical equilibrium between the megacrysts and kimberlitic melts. Here, we report results of a detailed geochronological and geochemical study of zircon megacrysts found in the Middle Devonian Novolaspa kimberlite pipe and dyke located in the Azov Domain of the Ukrainian Shield. The concordia age of zircons is 397.0 ± 2.0 Ma, and it is 14 m.y. older than the age of kimberlite emplacement as defined by a Rb-Sr isochron on phlogopite. The average ?Hf(397) value for unaltered zircon megacrysts is 6.8 ± 0.14, with the alteration rims having similar Hf isotope systematics. These hafnium isotope data indicate a moderately depleted mantle source for zircon. Unaltered megacrystic zircons have low abundances of trace elements and fractionated REE, with pronounced positive Ce/Ce* anomalies and almost no Eu/Eu* anomalies. In contrast, alteration rims have very high and variable concentrations of trace elements, indicating a reaction between zircon and kimberlite melt. The melt or fluid responsible for zircon and ilmenite megacryst formation, in contrast to kimberlitic melt, was poor in incompatible trace elements, except for the HFSE (Zr, Hf, Nb, Ta, and Ti). The oxygen fugacity during crystallization of the megacryst suite was close to the FMQ buffer. Azov zircon megacrysts do not demonstrate close geochronological and isotope-geochemical similarities with their host kimberlites. They are cognate in the broad sense of being related to the same plume event, but their direct affinity is not clearly defined. The megacryst suite may have crystallized from the earliest melts/fluids that separated from the ascending mantle plume, whereas kimberlite magmas were emplaced 14 m.y. after this event.
DS1991-0150
1991
Borodzich, E.V.Borodzich, E.V., Korotkin, M.R., et al.The origin of ring structuresDoklady Academy of Sciences USSR, Earth Science Section, Vol. 311, No. 1-6, Nov. pp. 50-53RussiaStructure, Ring structures
DS2000-0100
2000
Borofsky, R.L.Borofsky, R.L., Whitmore, R., Chamberlain, S.C.Scepter quartz crystals from the Treasure Mountain Diamond Mine. ( Herkimer ).Rocks and Minerals, Vol. 75, July/Aug. p. 231-7.GlobalHerkimer 'diamonds'
DS1990-0809
1990
Boronikhin, V.A.Kazanskiy, V.I., Novgorodova, M.I., Smirnov, Yu.P., Boronikhin, V.A.Unusual mineral associations in the lower levels of the Kola SuperdeepdrillholeInternational Geology Review, Vol. 32, No. 1, January pp. 84-91RussiaMineralogy, Kola drillhole
DS201610-1901
2016
Borovikov, A.A.Prokopyev, I.R., Borisenko, A.S., Borovikov, A.A., Pavlova, G.G.Origin of REE rich ferrocarbonatites in southern Siberia ( Russia): implications based on melt and fluid inclusions.Mineralogy and Petrology, in press available 15p.Russia, Kola PeninsulaDeposit - Tuva

Abstract: Fe-rich carbonatites with a mineral assemblage of ankerite-calcite or siderite are widespread in southern Siberia, Russia. The siderite carbonatites are associated with F-Ba-Sr-REE mineralization and have a 40Ar/39Ar age of 117.2 ± 1.3 Ma. Melt and fluid inclusions suggest that the carbonatites formed from volatile-rich alkali- and chloride-bearing carbonate melts. Ankerite-calcite carbonatites formed from carbonatite melt at a temperature of more than 790 °C. The ferrocarbonatites (the second phase of carbonatite intrusion) formed from a sulfate-carbonate-chloride fluid phase (brine-melt) at >650 °C and ?360 MPa. The brine-melt fluid phase had high concentrations of Fe and LREEs. A subsequent hydrothermal overprint contributed to the formation of economically important barite-Sr-fluorite-REE mineralization in polymict siderite breccia.
DS201701-0028
2016
Borovikov, A.A.Prokopyev, I.R., Borisenko, A.S., Borovikov, A.A., Pavlova, G.G.Origin of REE rich ferrocarbonatites in southern Siberia ( Russia): implications based on melt and fluid inclusions.Mineralogy and Petrology, Vol. 110, pp. 845-859.Russia, SiberiaCarbonatite

Abstract: Fe-rich carbonatites with a mineral assemblage of ankerite-calcite or siderite are widespread in southern Siberia, Russia. The siderite carbonatites are associated with F-Ba-Sr-REE mineralization and have a 40Ar/39Ar age of 117.2 ± 1.3 Ma. Melt and fluid inclusions suggest that the carbonatites formed from volatile-rich alkali- and chloride-bearing carbonate melts. Ankerite-calcite carbonatites formed from carbonatite melt at a temperature of more than 790 °C. The ferrocarbonatites (the second phase of carbonatite intrusion) formed from a sulfate-carbonate-chloride fluid phase (brine-melt) at >650 °C and ?360 MPa. The brine-melt fluid phase had high concentrations of Fe and LREEs. A subsequent hydrothermal overprint contributed to the formation of economically important barite-Sr-fluorite-REE mineralization in polymict siderite breccia.
DS201801-0006
2017
Borovikov, A.A.Borovikov, A.A., Vladykin, N.V., Tretiakova, I.G., Dokuchits, E.Yu.Physicochemical conditions of formation of hydrothermal titanium mineralization on the Murunskiy alkaline massif, western Alden ( Russia).Ore Geology Reviews, in press available, 10p.Russiaalkaline rocks
DS201709-1968
2017
Borovinskaya, O.Bussweiler, Y., Poitras, S., Borovinskaya, O., Tanner, M., Pearson, G.Rapid multielemental analysis of garnet with LA-ICP-TOF-MS implications for diamond exploration studies.Goldschmidt Conference, abstract 1p.Canada, Northwest Territoriesdiamond potential

Abstract: Garnet arguably constitutes the most important mineral in diamond exploration studies; not only can the presence of mantle garnet in exploration samples point to kimberlite occurrences, but its minor and trace element composition can further be used to assess the “diamond potential” of a kimberlite. The content of Cr and Ca, especially, has been found to be a reliable tool to test whether garnets originate from within the diamond stability field in the mantle [1]. Trace element patterns can further indicate the mantle host rock of the garnets, for example, whether they originate from a depleted or ultra-depleted mantle section [2]. Routinely, two separate analytical methods are necessary to fully characterize the composition of garnet; major and minor elements are usually determined by electron probe micro-analysis (EPMA), whereas determination of trace elements requires the more sensitive method of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Here, we demonstrate rapid measurement of the entire suite of elements in garnet employing a new, commercially available timeof-flight (TOF) mass spectrometer, the icpTOF (TOFWERK AG, Thun, Switzerland), coupled to a fast wash-out laser ablation system (Teledyne Cetac Technologies Inc., Omaha, NE, USA). Using garnets from exploration samples taken from the Horn Plateau, Northwest Territories, Canada [3], we directly compare the icpTOF results to EPMA and LA-ICP-MS data. We examine whether the icpTOF can reliably characterize the garnets in Cr versus Ca space and at the same time reproduce their trace element patterns, thereby offering a cost effective method of analysis. The method of LA-ICP-TOF-MS, with its high speed of data acquisition and its ability to record the entire mass spectrum simultaneously, may have great benefits for (diamond) exploration studies. Moreover, the method can be used for fast, highresolution imaging, which is applicable to a wide range of geological materials and settings [4].
DS1988-0697
1988
Borovkova, T.V.Timchenko, V.A., Borovkova, T.V., et al.Methods and results of deep geochemical mapping of closed areas when exploring for kimberlite bodies in western Yakutia.(Russian)Theory and Practice of geochemical exploration under modern conditions:text, pp. 93-94. abstractRussiaGeochemistry, Kimberlites
DS201412-1015
2014
Borozdin, A.P.Zaitsev, A.N., Williams, C.T., Jeffreis, T.E., Strekopytov, S., Moutte, J., Ivashchenkova, O.V., Spratt, J., Petrov, S.V., Wall, F., Seltmann, R., Borozdin, A.P.Rare earth elements in phoscorites and carbonatites of the Devonian Kola alkaline province, Russia: examples from Kovdor, Khibina, Vuoriyarvi and Turiy Mys complexes.Ore Geology Reviews, Vol. 64, pp. 204-225.Russia, Kola PeninsulaCarbonatite
DS201412-1017
2014
Borozdin, A.P.Zaitsev, A.N., Williams, C.T., Jeffries, T.E., Strekopytov, S., Moutte, J., Ivashchenkova, O.V., Spratt, J., Petrov, S.V., Wall, F., Seltmann, R., Borozdin, A.P.Rare earth elements in phoscorites and carbonatites of the Devonian Kola alkaline province, Russia: examples from Kovdor, Khibina, Vuoriyarvi and Turiy Mys complexes.Ore Geology Reviews, Vol. 61, pp. 204-225.Russia, Kola PeninsulaCarbonatite
DS201412-1019
2014
Borozdin, A.P.Zaitsev, A.N., Williams, C.T., Jeffries, T.E., Strekopytov, S., Moutte, J., Ivashchenkova, O.V., Spratt, J., Petrov, S.V., Wall, F., Seltmann, R., Borozdin, A.P.Rare earth elements in phoscorites and carbonatites of the Devonian Kola alkaline province, Russia: examples from Kovdor, Khibina, Vuoriyarvi and Turiy Mys complexes.Ore Geology Reviews, in press availableRussia, Kola PeninsulaCarbonatite
DS1988-0072
1988
Borradaile, G.J.Borradaile, G.J., Alford, C.Experimental shear zones and magnetic fabricsJournal of Structural Geology, Vol. 10, No. 8, pp. 895-904. Database # 17568GlobalShear zones, Structure- Magnetic fabrics
DS1993-0137
1993
Borradaile, G.J.Borradaile, G.J., erner, T., Dehls, J.F., Spark, R.N.Archean regional transpression and paleomagnetism in northwestern CanadaTectonophysics, Vol. 220, No. 1-4, April 15, pp. 117-126OntarioGeophysics, Paleomagnetism
DS1997-0113
1997
Borradaile, G.J.Borradaile, G.J., Henry, B.Tectonic applications of magnetic susceptibilty and its anisotropyEarth Science Reviews, Vol. 42, pp. 49-93GlobalMagnetic susceptibility - AMS, Tectonics
DS1999-0082
1999
Borradaile, G.J.Borradaile, G.J., Werner. T. Lagroix, F.Magnetic fabrics and anisotropy controlled thrusting in the Kapuskasing structural zone.Tectonophysics, Vol. 301, No. 3-4, Jan. 30, pp. 241-56.OntarioGeophysics - magnetics, Kapuskasing, midcontinent lineament
DS2001-0124
2001
Borradaile, G.J.Borradaile, G.J.Paleomagnetic vectors and tilted dikesTectonophysics, Vol. 333, No. 3-4, April pp. 417-26.GlobalDikes - not specific to diamonds
DS2003-0133
2003
Borradaile, G.J.Borradaile, G.J., Lemmetty, T.J., Werner, T.Apparent polar wander paths and the close of late Archean crustal transpressionJournal of Geophysical Research, Vol. 108, B8,Aug. 30., 2405 10.1029/2002JB002379OntarioGeophysics, geochronology
DS2003-0134
2003
Borradaile, G.J.Borradaile, G.J., Werner, T., Lagroix, F.Differences in paleomagnetic interpretations due to the choice of statisticalTectonophysics, Vol. 363, 1-2, Feb. 20, pp. 103-26.OntarioGeophysics - magnetics
DS2003-0135
2003
Borradaile, G.J.Borradaile, G.J., Werner, T., Lagroix, F.Difference in paleomagnetic interpretations due to choice of statistical, demagnetizationTectonophysics, Vol. 363, No. 1-2, Feb. 20, pp. 103-125.OntarioPaleomagnetics, tectonics
DS200412-0183
2003
Borradaile, G.J.Borradaile, G.J., Lemmetty, T.J., Werner, T.Apparent polar wander paths and the close of late Archean crustal transpression, northern Ontario.Journal of Geophysical Research, Vol. 108, B8,Aug. 30., 2405 10.1029/2002 JB002379Canada, OntarioGeophysics Geochronology
DS200412-0184
2003
Borradaile, G.J.Borradaile, G.J., Werner, T., Lagroix, F.Differences in paleomagnetic interpretations due to the choice of statistical, demagnetization and correction techniques: KapuskTectonophysics, Vol. 363, 1-2, Feb. 20, pp. 103-26.Canada, OntarioGeophysics - magnetics
DS1995-0174
1995
Borsato, R.A.Borsato, R.A.Seismic applications for the mining industryProspectors and Developers Association of Canada (PDAC) Preprint, 5pGlobalGeophysics -seismics
DS1989-0145
1989
Borsch, L.Borsch, L.Phosphate in stream sediments and soils as a potential geochemical guide to apatite mineralizations: an example from the Eastern Province, ZambiaZimco, MINEX seminar on Carbonatites and other igneous phosphate bearing, Held Feb. 1, 1989, 1pZambiaApatite, Phosphate
DS1989-0146
1989
Borsch, L.Borsch, L.The beneficiation of the Kaluwe and Nkombwa Hill brown soils- some preliminary laboratory tests on the extraction of phosphateZimco, MINEX seminar on Carbonatites and other igneous phosphate bearing, Held Feb. 1, 1989, 1pZambiaCarbonatite, Heap leaching
DS1995-0175
1995
Borsch, L.Borsch, L.Some observations on mineral properties and analytical reproducibility ingeochemical samplesMining Engineering, Vol. 47, No. 6, pp. 567-569GlobalGeochemistry -samples
DS201502-0082
2014
Borselli, L.Moreno Chavez, G., Sarocchi, D., Arce Santana, E., Borselli, L.Using Kinect to analyze pebble to block-sized clasts in sedimentology.Computers & Geosciences, Vol. 72, pp. 18-32.TechnologyNot specific to diamonds
DS1993-0138
1993
Borshchecskiy, Yu.A.Borshchecskiy, Yu.A., Laverova, T.N.Oxygen isotopes of ilmenite from diamond-bearing kimberlite pipesDoklady Academy of Sciences USSR, Earth Science Section, Vol. 321, No. 8, August 1993, pp. 188-191.Russia, Commonwealth of Independent States (CIS)Geochronology, Ilmenites
DS1991-0151
1991
Borshchevskii, Y.A.Borshchevskii, Y.A., Laverova, Y.N.Oxygen isotopic pecularities of ilmenite from diamond bearing kimberlitepipes.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 320, No. 1, pp. 174-176RussiaGeochronology, Ilmenite
DS201909-2050
2019
Borst, A.Hutchison, W., Baiel, R., Finch, A., Marks, M., Markl, G., Boyce, A., Stueken, E., Friis, H., Borst, A., Horsburgh, N.Sulphur isotopes of alkaline igneous suites: new insights into magmatic fluid evolution and crustal recycling.Goldschmidt2019, 1p. AbstractGlobalalkaline rocks
DS201212-0469
2012
Borst, A.M.Meulemans, T.J., Borst, A.M., Davidheriser, B., Davies, G.R.The origin and modification of the sub-continental lithospheric mantle of Botswana: constraints from peridotite xenoliths of the Orapa mine.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractAfrica, BotswanaDeposit - Orapa
DS201604-0594
2016
Borst, A.M.Borst, A.M., Friis, H., Andersen, T., Nielsen, T.F.D., Waight, T.E., Smit, M.A.Zirconosilicates in the kakortokites of the Ilmmaussaq complex, South Greenland: implications for fluid evolution and high field strength and rare earth element mineralization in agpaitic systems.Mineralogical Magazine, Vol. 80, 1, pp. 5-30.Europe, GreenlandRare earths

Abstract: The layered agpaitic nepheline syenites (kakortokites) of the Ilímaussaq complex, South Greenland, host voluminous accumulations of eudialyte-group minerals (EGM). These complex Na-Ca-zirconosilicates contain economically attractive levels of Zr, Nb and rare-earth elements (REE), but have commonly undergone extensive autometasomatic/hydrothermal alteration to a variety of secondary mineral assemblages. Three EGM alteration assemblages are recognized, characterized by the secondary zirconosilicates catapleiite, zircon and gittinsite. Theoretical petrogenetic grid models are constructed to assess mineral stabilities in terms of component activities in the late-stage melts and fluids. Widespread alteration of EGM to catapleiite records an overall increase in water activity, and reflects interaction of EGM with late-magmatic Na-, Cl- and F-rich aqueous fluids at the final stages of kakortokite crystallization. Localized alteration of EGM and catapleiite to the rare Ca-Zr silicate gittinsite, previously unidentified at Ilímaussaq, requires an increase in CaO activity and suggests post-magmatic interaction with Ca-Sr bearing aqueous fluids. The pseudomorphic replacement of EGM in the kakortokites was not found to be associated with significant remobilization of the primary Zr, Nb and REE mineralization, regardless of the high concentrations of potential transporting ligands such as F and Cl. We infer that the immobile behaviour essentially reflects the neutral to basic character of the late-magmatic fluids, in which REE-F compounds are insoluble and remobilization of REE as Cl complexes is inhibited by precipitation of nacareniobsite-(Ce) and various Ca-REE silicates. A subsequent decrease in F- activity would furthermore restrict the mobility of Zr as hydroxyl-fluoride complexes, and promote precipitation of the secondary zirconosilicates within the confines of the replaced EGM domains.
DS201906-1351
2019
Borst, A.M.Smith, M.P., Estrade, G., Marquis, E., Goodenough, K., Nason, P., Xu, C., Kynicky, J., Borst, A.M., Finch, A.A., Villanova de Benevent, C.Ion adsorption deposits: a comparison of deposits in Madagascar and China.3rd International Critical Metals Meeting held Edinburgh, 1p.abstract p. 53.Africa, Madagascar, ChinaREE

Abstract: Link to presentation pdf.
DS201909-2021
2019
Borst, A.M.Beard, C.D., Goodenough, K.M., Broom-Findlay, S., Borst, A.M., Roberts, N.M.W., Finch, A.A., Deady, E.A.Subducted sediments as a source of REE in mineralized post - collisional alkaline carbonatite systems.Goldschmidt2019, 1p. AbstractChinasubduction

Abstract: Many of the world's largest known REE deposits are associated with post-collisional alkaline-carbonatite magmatic complexes (e.g., the Minanning-Dechang belt, China). These systems are potassic to ultrapotassic in composition and contain LREE-dominated mineralisation associated with F and Ba-rich carbonatite breccias, carbonatite dykes and carbo-hydrothermal veins. They are typically emplaced through major shear zones during a period of 'relaxation' that postdates continental collision by up to 75 Ma. The subduction of sediment during continental collision is potentially a key control on the 'fertility' of the mantle source, and understanding the role of sediment is a crucial step towards better exploration models. However, the identification of sediment source components to alkaline systems has not been straightforward because their petrological complexity precludes traditional methods such as trace-element ratios and major-element modelling of crystal fractionation. We use a global database of Sr, Nd and Hf isotope compositions for alkaline and carbonatite systems, alongside geodynamic reconstructions to identify favourable source components for mineralisation and to provide direct information about the origin of the metals of interest. Subduction of shale and carbonate sequences is likely to introduce REE + HFSE and potentially mineralising ligands (F-, CO3 2-) into the mantle source for post-collisional alkaline systems; clastic sediments are poorer in these vital components. This research provides a framework through which the mineral exploration industry can identify tectonic environments that are predisposed to form REE mineralisation, providing regional-scale (100-1000 km) guidance especially for systems hidden beneath sedimentary cover.
DS202011-2030
2012
Borst, A.M.Borst, A.M.The formation and modification of the sub-cratonic lithospheric mantle beneath Botswana. A petrological, geochemical and isotopic study of peridotite xenoliths from the Letlhakane kimberlite mine. *** note dateMsc. Thesis VRIJE University Amsterdam, 166p. Academia available pdfAfrica, Botswanadeposit - Letlhakane

Abstract: The Letlhakane kimberlite pipes are emplaced in the Proterozoic Makondi Fold Belt, Botswana. They belong to a cluster of kimberlite diatremes that also includes the Orapa diamond mine, approximately 40 km to the northwest. In a previous geochemical study on Letlhakane xenoliths it was proposed that the Makondi Fold Belt is underlain by Archaean mantle that belongs to the Zimbabwe Craton. This implies the Letlhakane Kimberlites were sourced from the edge of Zimbabwe cratonic mantle and ascended through Proterozoic Makondi crust, explaining their rather anomalous tectonic setting. In this study we aim to verify the Archaean nature of the lithospheric mantle beneath Letlhakane and assess the origin and extent of metasomatic modifications in comparison to the Kaapvaal and Zimbabwe Cratons. We present an extensive petrological, geochemical and isotopic dataset on a selection of 38 peridotite xenoliths from Letlhakane in order to characterize the mantle that underlies northern Botswana. Whole rock and mineral major and trace elements were measured by electron microprobe (EMP), laser ablation ICPMS and XRF. Sm-Nd and Lu-Hf isotope analyses were performed on garnet, cpx and amphibole separates from 12 selected samples. The sample suite includes spinel harzburgites, spinel lherzolites, a spinel dunite, a wehrlite, a garnet websterite, garnet harzburgites, garnet lherzolites and amphibole bearing garnet lherzolites. The samples are categorized into four groups based on garnet chemistry and modal compositions: I) garnet free samples, II) garnet harzburgites, II) garnet lherzolites and IV) amphibole-bearing garnet lherzolites. Whole rock major elements and olivine magnesium numbers suggest that the SCLM experienced 20 to 60% melt depletion between 5 and 3 GPa. Reconstructed whole rock HREE concentrations and Lu-Yb systematics indicate that up to 20% melting occurred in the absence of garnet, leading to strong fractionation of HREE. The data suggest a shallow decompressional melting regime, consistent with Archaean cratonic genesis models. Preliminary Re-Os data suggest melt depletion occurred at ~2.7 Ga. All samples experienced various amounts of metasomatic re-enrichment expressed by high modal abundances of garnet, opx, clinopyroxene and amphibole. Silica enrichment occurred to a lesser extent than observed in the Kaapvaal, but the Letlhakane samples show significantly more opx-rich assemblages than reported for the Zimbabwe Craton. Sm-Nd and Lu-Hf isotope signatures of garnet harzburgites suggest LREE enrichment occurred around ~2.0 Ga, possibly related to major tectono-magmatic activity associated with accretion of the Makondi Fold Belt to the Zimbabwe Craton. Cpx from the garnet lherzolites show major isotopic interaction and re-equilibration with Group I Kimberlites, which probably crystallized from pre-cursor kimberlitic melts prior to the Letlhakane eruption at ~93 Ma. Trace elements and Nd-Hf istope systematics of the amphibole bearing samples suggest amphibole metasomatism occurred from a LREE, Na, Ka, Ca and Al enriched hydrous melt around 500 to 600 Ma, possibly associated with Pan-African magmatic activity in northern Botswana. The overall lack of negative Nb-Ta anomalies suggests that metasomatic melts were generated in a within-plate geodynamical environment, rather than a subduction related setting.
DS202204-0536
2022
Borst, A.M.Sokol, K., Finch, A.A., Hutchison, W., Cloutier, J., Borst, A.M., Humphreys, M.C.S.Quantifying metasomatic high-field-strength and rare-earth element transport from alkaline magmas.Geology, Vol. 50, 3, pp. 305-310.Europe, Greenlandalkaline

Abstract: Alkaline igneous rocks host many global high-field-strength element (HFSE) and rare-earth element (REE) deposits. While HFSEs are commonly assumed to be immobile in hydrothermal systems, transport by late-stage hydrothermal fluids associated with alkaline magmas is reported. However, the magnitude of the flux and the conditions are poorly constrained and yet essential to understanding the formation of REE-HFSE ores. We examined the alteration of country rocks (“fenitization”) accompanying the emplacement of a syenite magma at Illerfissalik in Greenland, through analysis of changes in rock chemistry, mineralogy, and texture. Our novel geochemical maps show a 400-m-wide intrusion aureole, within which we observed typically tenfold increases in the concentrations of many elements, including HFSEs. Textures suggest both pervasive and structurally hosted fluid flow, with initial reaction occurring with the protolith's quartz cement, leading to increased permeability and enhancing chemical interaction with a mixed Ca-K-Na fenitizing fluid. We estimated the HFSE masses transferred from the syenite to the fenite by this fluid and found ~43 Mt of REEs were mobilized (~12% of the syenite-fenite system total rare-earth-oxide [TREO] budget), a mass comparable to the tonnages of some of the world's largest HFSE resources. We argue that fenite can yield crucial information about the tipping points in magma evolution because retention and/or loss of volatile-bonded alkali and HFSEs are key factors in the development of magmatic zirconosilicate-hosted HFSE ores (e.g., Kringlerne, at Ilímaussaq), or the formation of the syenite-hosted Nb-Ta-REE (Motzfeldt-type) roof-zone deposits.
DS201212-0081
2012
Bort, A.M.Bort, A.M., Davidheisser, B., Meulemens, T., Davies, G.R.The origin and evolution of the lithospheric mantle beneath the Makondi fold belt in Botswana: an extensive geochemical study of peridotite xenoliths from the Lethlakane diamond mine.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractAfrica, BotswanaDeposit - Lethlhakane
DS200412-0553
2004
Bortnikov, N.S.Filimonova, L.G., Trubkin, N.V., Bortnikov, N.S.Moissanite nanoparticles in disseminated mineralization of the Dukat ore district, northeastern Russia.Doklady Earth Sciences, Vol. 394, 1, Jan-Feb. pp. 137-140.RussiaMoissanite
DS201610-1889
2016
Bortnikov, N.S.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.
DS202104-0611
2021
Bortnikov, N.S.Titkov, S.V., Yakovleva, V.V., Breev, I.D., Anisimov, A.N., Baranov, P.G., Dorofeeva, A.I., Bortnikov, N.S.Distribution of nitrogen-vacancy NV centers in cubic diamond crystals from Anabar placers as revealed by ODMR and PL tomography.Doklady Earth Sciences, Vol. 496, 1, pp. 45-47. pdfRussiadeposit - Anabar

Abstract: Nitrogen-vacancy NV- centers, which are of considerable interest for quantum electronics, are artificially produced in the diamond structure by irradiation and subsequent annealing. In this work, these centers were revealed in natural diamonds of cubic habit (type IaA + Ib according to physical classification) from an industrial placer deposit of the Anabar River (NE Siberian platform) using the method of optically detected magnetic resonance (ODMR). Localization of the NV- centers in the dislocations slip planes {111}, separated by distances of about 5 ?m, was established by means of scanning the ODMR and PL signals with a submicron resolution. In various crystals, one or two intersecting systems of such slip planes have been revealed. The largest amounts of these defects were found in the peripheral zones of crystals containing increased amounts of single isomorphic nitrogen atoms in the structure. The data obtained indicate the formation of the NV- centers in natural diamonds under post-crystallization plastic deformation, i.e., by a mechanism that differs from the widely used method of their artificial production.
DS200512-0716
2005
Bortsu, P.Melluso, L., Morra, V., Bortsu, P., Tommasini, S., Renna, MR, Duncan, R., Franciosi, L., D'Amelio, F.Geochronology and petrogenesis of the Cretaceous Antampombato Ambatovy Complex and associated dyke swarm, Madagascar.Journal of Petrology, Vol. 46, 10, pp. 1963-1996.Africa, MadagascarGeochronology - dike
DS1992-0145
1992
Borukaev, Ch. B.Borukaev, Ch. B., Basharin, A.K., Berzin, N.A., Votakh, O.A., et al.Tectonic evolution of the earth's crust in SiberiaRussian Geology and Geophysics, Vol. 33, No. 4, pp. 1-5Russia, SiberiaTectonics
DS1994-0186
1994
Borukaev, Ch.B.Borukaev, Ch.B., Natalin, B.A.Accretionary tectonics of the southern part of Russian far EastRussian Geology and Geophysics, Vol. 35, No. 7-8, pp. 73-77.RussiaTectonics
DS1996-0156
1996
Borukaev, Ch.B.Borukaev, Ch.B.Late Archean plate tectonicsRussian Geology and Geophysics, Vol. 37, No. 1, pp. 29-36RussiaPlate tectonics, Archean
DS1995-0140
1995
Borutskiy, B.Ye.Belyayevskaya, G.P., Borutskiy, B.Ye.The relation between the actual chemical composition and the crystal structure of lamprophyllite.Doklady Academy of Sciences, Vol. 329, No. 2, Jan. pp. 142-146.RussiaLamprophyllite
DS1990-0223
1990
Boryta, M.Boryta, M., Condie, K.C.Geochemistry and origin of the Archean Beit Bridge complex, Limpopo @South AfricaJournal of the Geological Society of London, Vol. 147, pt. 2, March pp. 229-240South AfricaGeochemistry, Beit Bridge Complex
DS1997-0881
1997
BorzdovPalyanov, Y.N., Borzdov, Sokol, Khokhryakov, Gusev ..Dislocation free monocrystals of sythetic diamondDoklady Academy of Sciences, Vol. 353, No. 2, Feb-Mar, pp. 243-6.GlobalDiamond - synthetics, crystallography
DS1998-1108
1998
BorzdovPalyanov, Y.N., Gusev, V.A., Kupriyanov, Borzdov, SokolThe effect of growth rate on formation of nitrogenous defects in diamond7th. Kimberlite Conference abstract, pp. 649-51.RussiaDiamond inclusions, Mineralogy
DS2002-1206
2002
BorzdovPalyanov, Y.N., Sokol, A.G., Borzdov, KhokhryakovFluid bearing alkaline carbonate melts as the medium for the formation of diamonds in Earth's mantle:Lithos, Vol.60, pp. 145-59.MantleDiamond - crystallization, melting, UHP, Petrology - experimental
DS1997-0883
1997
Borzdov, et al.Palyanov, Y.N., Sokol, A.G., Borzdov, et al.Synthesis and characterization of diamond single crystals up to 4 caratsDoklady Academy of Sciences, Vol. 355A, No. 6, July-Aug. pp. 856-61.RussiaDiamond morphology, Diamond synthesis
DS2000-0913
2000
Borzdov, et al.Sokol, A.G., Tomilenko, A.A., Palyanov, Borzdov, et al.Fluid regime of diamond crystallization in carbonate carbon systemsEuropean Journal of Mineralogy, Vol. 12, pp. 367-75.GlobalDiamond - morphology, crystal, Petrology - experimental
DS2002-1204
2002
Borzdov, M.Palyanov, N., Sokol, A.G., Borzdov, M., Khokhryakov, A.Fluid bearing alkaline carbonate melts as the medium for the formation of diamonds in Earth's mantle:Lithos, Vol. 60, No. 3-4, Feb. pp. 145-59.MantlePetrology - experimental study
DS1997-0882
1997
Borzdov, Sokol et al.Palyanov, Y.N., Khokhryakov, A., Borzdov, Sokol et al.Growth conditions and real structure of synthetic diamond crystalsRussian Geology and Geophysics, Vol. 38, No. 5, pp. 920-45.GlobalDiamond morphology, Synthetics
DS2002-1205
2002
Borzdov, V.M.Palyanov, Y.N., Sokol, A.C., Borzdov, V.M.Diamond formation through carbonate silicate interactionAmerican Mineralogist, Vol.87,7, pp. 1009-13.GlobalDiamond - genesis, morphology
DS201512-1960
2015
Borzdov, Y.Reutsky, V., Borzdov, Y., Palyanov, Y., Sokol, A., Izokh, O.Carbon isotope fractionation during experimental crystallization of diamond from carbonate fluid at mantle conditions.Contributions to Mineralogy and Petrology, Vol. 170, pp. 41-MantleHPHT

Abstract: We report first results of a systematic study of carbon isotope fractionation in a carbonate fluid system under mantle PT conditions. The system models a diamond-forming alkaline carbonate fluid using pure sodium oxalate (Na2C2O4) as the starting material, which decomposes to carbonate, CO2 and elementary carbon (graphite and diamond) involving a single source of carbon following the reaction 2Na2C2O4 ? 2Na2CO3 + CO2 + C. Near-liquidus behaviour of carbonate was observed at 1300 °C and 6.3 GPa. The experimentally determined isotope fractionation between the components of the system in the temperature range from 1300 to 1700 °C at 6.3 and 7.5 GPa fit the theoretical expectations well. Carbon isotope fractionation associated with diamond crystallisation from the carbonate fluid at 7.5 GPa decreases with an increase in temperature from 2.7 to 1.6 ‰. This trend corresponds to the function ?Carbonate fluid-Diamond = 7.38 × 106 T?2.
DS201909-2019
2019
Borzdov, Y.Bataleva, Y., Palyanov, Y., Borzdov, Y., Bayukov, O.Processes and conditions of the origin of Fe3+- bearing magnesiowustite under lithospheric mantle pressures and temperatures.Minerals, Vol. 9, 8, p. 474-MantleUHP

Abstract: An experimental study, implicated in the revealing of the conditions for the origin for Fe3+-bearing magnesiowüstite in the lithospheric mantle, was performed using Mössbauer spectroscopy of pre-synthesized samples. Experiments were carried out using a multi-anvil high-pressure split-sphere apparatus at 6.3-7.5 GPa, in the range of 1100-1650 °C in carbonate-metal, carbonate-oxide-metal, carbonate-oxide, carbide-oxide and carbonate-metal- sulphur systems. In three experimental series, oxygen fugacity gradient in the samples was created, which enabled the study of the processes of magnesiowüstite formation under oxidizing and reducing conditions (?logfO2 (FMQ) values from ?1 to ?5). It was established that Fe3+-bearing magnesiowüstite can form both in assemblage with oxidized phases, such as carbonate or with reduced ones—metal, carbides, sulphides, graphite and diamond. According to the Mössbauer spectroscopy, the composition of synthesized magnesiowüstite varied within a range of Fe3+/?Fe values from 0 to 0.3, with IV and VI coordination of Fe3+ depending on P, T, fO2, x-parameters. It was established that Fe3+-bearing magnesiowüstite formation processes under upper mantle P,T-conditions include redox reactions, with magnesiowüstite being (1) reductant or (2) product of interaction, (3) crystallization processes of magnesiowüstite from an oxidized melt, where magnesiowüstite acts as a sink for ferric iron and (4) iron disproportionation.
DS1998-1109
1998
Borzdov, Y.M.Palynaov, Yu.N., Sokol, A.G., Borzdov, Y.M., et al.Diamond crystallization in the systems CaCO3-C, MgCO3-C, CaMg (CO3)-CDoklady Academy of Sciences, Vol. 363, No. 8, Oct-Nov. pp. 1156-60.GlobalDiamond mineralogy - experimental, Diamond morphology
DS2000-0101
2000
Borzdov, Y.M.Borzdov, Y.M., Sokol, Palyanov, Khokhryakov, SobolevGrowth of synthetic diamond monocrystals weighing up to six carats and perspectives of their application.Doklady Academy of Sciences, Vol. 374, No. 7, Sept-Oct. pp. 1113-5.RussiaDiamond - morphology, Diamond - synthesis, Crystallography
DS2001-1100
2001
Borzdov, Y.M.Sokol, A.G., Borzdov, Y.M., Palynov, Y.M.An experimental demonstrator of diamond formation in the dolomite carbon and dolomite fluid carbon systems.Eur. Jour. Min., Vol. 13, No. 5, pp. 893-900.RussiaCarbonatite, Petrology - experimental
DS2002-0190
2002
Borzdov, Y.M.Borzdov, Y.M., Palyanov, Y.N., Kupriyanov, I.N.Synthesis and characterisation of diamond from a calcium carbonate graphite system18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.79. (poster)GlobalUHP mineralogy - crystallography
DS2002-1207
2002
Borzdov, Y.M.Palyanov, Y.N., Sokol, A.G., Borzdov, Y.M., Khokhryakov, A.F., Sobolev, N.V.Diamond formation through carbonate silicate interactionAmerican Mineralogist, Vol. 87, pp. 1009-13.GlobalDiamond - crystallography, genesis, carbon, magnesite, Petrology - experimental
DS200412-1492
2004
Borzdov, Y.M.Palyanov, Yu.N., Borzdov, Y.M., Kupriyanov, I.N., Sobolev, N.V.Diamond and graphite crystallization from pentlandite melt at HPHT conditions.Lithos, ABSTRACTS only, Vol. 73, p. S82. abstractTechnologyDiamond nucleation
DS200712-0796
2007
Borzdov, Y.M.Palyanov, Y.N., Borzdov, Y.M., Batleva, Y.V., Sokol, A.G., Palyanova, G.A.Reducing role of sulfides and diamond formation in the Earth's mantle.Earth and Planetary Science Letters, Vol. 260, 1-2, pp. 242-256.MantleDiamond genesis
DS200812-0952
2008
Borzdov, Y.M.Reutsky, V.N., Harte, B., EIMF, Borzdov, Y.M., Palyanov, Y.N.Monitoring diamond crystal growth, a combined experimental and SIMS study.European Journal of Mineralogy, Vol. 20, no. 3, pp. 365-374.TechnologyDiamond morphology
DS201012-0561
2010
Borzdov, Y.M.Palyanov, Y.N., Borzdov, Y.M., Khokhryakov, A.F.,Kupriyanov, I.N., Sokol, A.G.Effect of nitrogen impurity on diamond crystal growth processes.Crystal Growth & Design, Vol. 10, 6, pp. 3169-3175.TechnologyDiamond morphology
DS201012-0562
2009
Borzdov, Y.M.Palyanov, Y.N., Kupriyanov, I.N., Borzdov, Y.M., Sokol, A.G., Khokhryakov, A.F.Diamond crystallization from a sulfur - carbon system at HPHT conditions.Crystal Growth & Design, Vol. 9, 6, pp. 2922-2926.TechnologyDiamond synthesis
DS201412-0658
2014
Borzdov, Y.M.Palyanov, Y.N., Bataleva, Y.V., Sokol, A.G., Borzdov, Y.M., Kupriyanov, I.N., Reutsky, V.N., Sobolev, N.V.Mantle slab interaction and redox mechanism of diamond formation.Proceedings of National Academy of Science USA, Vol. 110, 51, Dec. 17, pp.MantleUHP, deep carbon cycle
DS201412-0659
2013
Borzdov, Y.M.Palyanov, Y.N., Khokhryakov, A.F., Borzdov, Y.M., Kupriyanov, I.N.Diamond growth and morphology under the influence of impurity adsorption.Crystal Growth & Design, Vol. 13, no. 12, pp. 5411-21.TechnologyDiamond morphology
DS201509-0417
2015
Borzdov, Y.M.Palyanov, Y.N., Borzdov, Y.M., Kupriyanov, I.N., Bataleva, Y.V., Khohkhryakov, A.F.Diamond crystallization from tin-carbon system at HPHT conditions.Diamond and Related Materials, Vol. 58, pp. 40-45.TechnologyDiamond synthetics

Abstract: Diamond crystallization from the tin–carbon system has been studied at 7 GPa and temperatures ranging from 1600 to 1900 °C with reaction times from 1 to 20 h. Both diamond growth on the seed crystals and diamond spontaneous nucleation were established, providing evidence for the catalytic ability of tin. A distinctive feature of the Sn–C system is the existence of a significant induction period preceding diamond spontaneous nucleation. Temperature and kinetics are found to be the main factors governing diamond crystallization process. The minimum parameters of diamond spontaneous nucleation are determined to be 7 GPa, 1700 °C and 20 h. The stable form of diamond growth is octahedron and it does not depend on temperature. Synthesized diamonds contain high concentrations of nitrogen impurities up to about 1600 ppm.
DS201601-0005
2015
Borzdov, Y.M.Bataleva, Y.V., Palyanov, Y.N., Sokol, A.G., Borzdov, Y.M., Bayukov, O.A.Wustite stability in the presence of CO2 -fluid and a carbonate silicate melt: implications for the graphite/diamond formation and generation of Fe-rich mantle metasomatic agents.Lithos, in press available, 40p.MantleMelting
DS201602-0193
2016
Borzdov, Y.M.Bataleva, Y.V., Palyanov, Y.N., Sokol, A.G., Borzdov, Y.M., Bayukov, O.A.Wustite stability in the presence of CO2 fluid and a carbonate silicate melt: implications for the graphite/diamond formation and generation of Fe rich mantle metasomatic agents.Lithos, Vol. 244, pp. 20-29.GlobalFerropericlase inclusions

Abstract: Experimental simulation of the interaction of wüstite with a CO2-rich fluid and a carbonate-silicate melt was performed using a multianvil high-pressure split-sphere apparatus in the FeO-MgO-CaO-SiO2-Al2O3-CO2 system at a pressure of 6.3 GPa and temperatures in the range of 1150 °C–1650 °C and with run time of 20 h. At relatively low temperatures, decarbonation reactions occur in the system to form iron-rich garnet (Alm75Prp17Grs8), magnesiowüstite (Mg# ? 0.13), and CO2-rich fluid. Under these conditions, magnesiowüstite was found to be capable of partial reducing CO2 to C0 that leads to the formation of Fe3+-bearing magnesiowüstite, crystallization of magnetite and metastable graphite, and initial growth of diamond seeds. At T ? 1450 °C, an iron-rich carbonate-silicate melt (FeO ~ 56 wt.%, SiO2 ~ 12 wt.%) forms in the system. Interaction between (Fe,Mg)O, SiO2, fluid and melt leads to oxidation of magnesiowüstite and crystallization of fayalite-magnetite spinel solid solution (1450 °C) as well as to complete dissolution of magnesiowüstite in the carbonate-silicate melt (1550 °C–1650 °C). In the presence of both carbonate-silicate melt and CO2-rich fluid, dissolution (oxidation) of diamond and metastable graphite was found to occur. The study results demonstrate that under pressures of the lithospheric mantle in the presence of a CO2-rich fluid, wüstite/magnesiowüstite is stable only at relatively low temperatures when it is in the absolute excess relative to CO2-rich fluid. In this case, the redox reactions, which produce metastable graphite and diamond with concomitant partial oxidation of wüstite to magnetite, occur. Wüstite is unstable under high concentrations of a CO2-rich fluid as well as in the presence of a carbonate-silicate melt: it is either completely oxidized or dissolves in the melt or fluid phase, leading to the formation of Fe2 +- and Fe3 +-enriched carbonate-silicate melts, which are potential metasomatic agents in the lithospheric mantle.
DS201608-1431
2016
Borzdov, Y.M.Palyanov, Y.N., Kupriyanov, I.N., Sokol, A.G., Borzdov, Y.M., Khokhryakov, A.F.Effect of CO2 on crystallization and properties of diamond from ultra-alkaline carbonate melt.Lithos, in press available, 12p.TechnologyDiamond formation

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

Abstract: Experiments on the synthesis of inclusions-bearing diamond were performed in the SiO2-((Mg,Ca)CO3-(Fe,Ni)S system at 6.3 GPa and 1650-1750 °C, using a multi-anvil high pressure apparatus of the "split-sphere" type. Diamond synthesis was realized in the "sandwich-type" experiments, where the carbonate-oxide mixture acted as a source of both CO2-dominated fluid and carbonate-silicate melt, and Fe,Ni-sulfide played a role of reducing agent. As a result of redox reactions in the carbonate-oxide-sulfide system, diamond was formed in association with graphite and Mg,Fe-silicates, coexisting with CO2-rich fluid, carbonate-silicate and sulfide melts. The synthesized diamonds are predominantly colorless or light-yellow monocrystals with octahedral habit (20-200 ?m), and polycrystalline aggregates (300-400 ?m). Photoluminescence spectroscopy revealed defects related to nickel impurity (S3 optical centers), which are characteristic of many diamonds in nature. The density of diamond crystallization centers over the entire reaction volume was ~3 × 102-103 cm? 3. The overwhelming majority of diamonds synthesized were inclusions-bearing. According to Raman spectroscopy data, diamond trapped a wide variety of inclusions (both mono- and polyphase), including orthopyroxene, olivine, carbonate-silicate melt, sulfide melt, CO2-fluid, graphite, and diamond. The Raman spectral pattern of carbonate-silicate melt inclusions have bands characteristic of magnesite and orthopyroxene (± SiO2). The spectra of sulfide melt displayed marcasite and pyrrhotite peaks. We found that compositions of sulfide, silicate and carbonate phases are in good agreement not only with diamond crystallization media in experiments, but with data on natural diamond inclusions of peridotitic and eclogitic parageneses. The proposed methodological approach of diamond synthesis can be used for experimental simulation of the formation of several types of mineral, fluid and melt inclusions, observed in natural diamonds.
DS201905-1016
2019
Borzdov, Y.M.Bataleva, Y.V., Palyanov, Y.N., Borzdov, Y.M., Novoselov, I.D., Bayukov, O.A.An effect of reduced S-rich fluids on diamond formation under mantle- slab interaction.Lithos, Vol. 336-337, pp. 27-39.Mantlediamond genesis

Abstract: Experimental study, dedicated to understanding the effect of S-rich reduced fluids on the diamond-forming processes under subduction settings, was performed using a multi-anvil high-pressure split-sphere apparatus in Fe3C-(Mg,Ca)CO3-S and Fe0-(Mg,Ca)CO3-S systems at the pressure of 6.3?GPa, temperatures in the range of 900-1600?°C and run time of 18-60?h. At the temperatures of 900 and 1000?°C in the carbide-carbonate-sulfur system, extraction of carbon from cohenite through the interaction with S-rich reduced fluid, as well as C0-producing redox reactions of carbonate with carbide were realized. As a result, graphite formation in assemblage with magnesiowüstite, cohenite and pyrrhotite (±aragonite) was established. At higher temperatures (?1100?°C) formation of assemblage of Fe3+-magnesiowüstite and graphite was accompanied by generation of fO2-contrasting melts - metal-sulfide with dissolved carbon (Fe-S-C) and sulfide-oxide (Fe-S-O). In the temperature range of 1400-1600?°C spontaneous diamond nucleation was found to occur via redox interactions of carbide or iron with carbonate. It was established, that interactions of Fe-S-C and Fe-S-O melts as well as of Fe-S-C melt and magnesiowüstite, were ?0-forming processes, accompanied by disproportionation of Fe. These resulted in the crystallization of Fe3+-magnesiowüstite+graphite assemblage and growth of diamond. We show that a participation of sulfur in subduction-related elemental carbon-forming processes results in sharp decrease of partial melting temperatures (~300?°C), reducting the reactivity of the Fe-S-C melt relatively to FeC melt with respect to graphite and diamond crystallization and decrease of diamond growth rate.
DS201906-1272
2019
Borzdov, Y.M.Bataleva, Y.V., Palyanov, Y.N., Borzdov, Y.M., Novoselov, I.D., Bayukov, O.A.An effect of reduced S rich fluids on diamond formation under mantle-slab interaction.Lithos, Vol. 336-337, pp. 27-39.Mantlediamond genesis

Abstract: Duplicate
DS202102-0213
2021
Borzdov, Y.M.Palyanov, Y.N., Borzdov, Y.M., Sokol, A.G., Btaaleva, Y.V., Kupriyanov, I.N., Reitsky, V.N., Wiedenbeck, M., Sobolev, N.V.Diamond formation in an electric field under deep Earth conditions.Science Advances, Vol. 7, 4, eabb4644 doi: 10.1126/ sciadv.abb4644 28p. PdfMantlegeophysics

Abstract: Most natural diamonds are formed in Earth’s lithospheric mantle; however, the exact mechanisms behind their genesis remain debated. Given the occurrence of electrochemical processes in Earth’s mantle and the high electrical conductivity of mantle melts and fluids, we have developed a model whereby localized electric fields play a central role in diamond formation. Here, we experimentally demonstrate a diamond crystallization mechanism that operates under lithospheric mantle pressure-temperature conditions (6.3 and 7.5 gigapascals; 1300° to 1600°C) through the action of an electric potential applied across carbonate or carbonate-silicate melts. In this process, the carbonate-rich melt acts as both the carbon source and the crystallization medium for diamond, which forms in assemblage with mantle minerals near the cathode. Our results clearly demonstrate that electric fields should be considered a key additional factor influencing diamond crystallization, mantle mineral-forming processes, carbon isotope fractionation, and the global carbon cycle.
DS1992-1159
1992
Borzdov, Yu.M.Palyanov, Yu.N., Malinovskiy, I.Yu., Borzdov, Yu.M., KhokhryakovUse of the split sphere apparatus for growing large diamond crystals without the use of a hydraulic press.Doklady Academy of Sciences USSR, Earth Science Section, Vol. 315, pp. 233-237.RussiaDiamond synthesis
DS1995-1421
1995
Borzdov, Yu.M.Palyanov, Yu.N., Khokhyakov, A.F., Borzdov, Yu.M., SokolDiamond morphology in growth and dissolution processesProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 415-417.GlobalDiamond morphology, Diamond growth
DS2002-1453
2002
Borzdov, Yu.M.Shatsky, A.F., Borzdov, Yu.M., Sokol, A.G., Palyanov, Y.N.Phase formation and diamond crystallization in carbon bearing ultrapotassic carbonate silicate systems.Russian Geology and Geophysics, Vol. 43, 10, pp. 889-901.GlobalDiamond - morphology
DS2003-1043
2003
Borzdov, Yu.M.Palyanov, Yu.N., Borzdov, Yu.M., Ovchinnikov, I.Yu., Sobolev, N.V.Experimental study of the interaction between pentlandite melt and carbon at mantle PtDoklady Earth Sciences, Vol. 392, Sept-Oct. pp. 1026-29.MantleCrystallography
DS200412-1493
2003
Borzdov, Yu.M.Palyanov, Yu.N., Borzdov, Yu.M., Ovchinnikov, I.Yu., Sobolev, N.V.Experimental study of the interaction between pentlandite melt and carbon at mantle Pt parameters: condition of diamond and grapDoklady Earth Sciences, Vol. 392, Sept-Oct. pp. 1026-29.MantleCrystallography
DS200612-1022
2006
Borzdov, Yu.M.Palyanov, Yu.N., Borzdov, Yu.M., Khokhryakov, A.F., Kupriyanov, I.N., Sobolev, N.V.Sulfide melts - graphite interaction at HPHT conditions: implications for diamond genesis.Earth and Planetary Science Letters, Vol. 250, 1-2, Oct. 15, pp. 269-280.MantleUHP, diamond genesis, carbon
DS200612-1156
2006
Borzdov, Yu.M.Reutskiy, V.N., Harte, B., Borzdov, Yu.M., Palyanov, Yu.N.Carbon and nitrogen effects during HTHP diamond crystallization.International Mineralogical Association 19th. General Meeting, held Kobe, Japan July 23-28 2006, Abstract p. 139.TechnologyDiamond morphology
DS200712-0797
2007
Borzdov, Yu.M.Palyanov, Y.N., Borzdov, Yu.M., Bataleva, Yu.V., Sokol, A.G., Palyanova, G.A., Kupriyanov, I.N.Reducing role of sufides and diamond formation in the Earth's mantle.Earth and Planetary Science Letters, Vol. 260, 1-2, pp. 242-256.MantleDiamond genesis
DS200712-0798
2007
Borzdov, Yu.M.Palyanov, Y.N., Borzdov, Yu.M., Bataleva, Yu.V., Sokol, A.G., Palyanova, G.A., Kupriyanov, I.N.Reducing role of sufides and diamond formation in the Earth's mantle.Earth and Planetary Science Letters, Vol. 260, 1-2, pp. 242-256.MantleDiamond genesis
DS200812-0951
2008
Borzdov, Yu.M.Reutsky, V.N., Borzdov, Yu.M., Palyanov, Yu.N.Carbon isotope fractionation associated with HPHT crystallization of diamond.Diamond and Related Materials, Vol. 17, 11, November pp. 1986-1989.TechnologyUHP
DS201212-0061
2012
Borzdov, Yu.M.Bataleva, Yu.V., Palyanov, Yu.N., Sokol, A.G., Borzdov, Yu.M., Sobolev, N.V.Conditions of formation of Cr-pyrope and escolaite during mantle metasomatism: experimental modeling.Doklady Earth Sciences, Vol. 442, 1, pp. 76-80.TechnologyMetasomatism
DS201502-0092
2015
Borzdov, Yu.M.Reutsky, V.N., Palyanov, Yu.N., Borzdov, Yu.M., Sokol, A.G.Isotope fractionation of carbon during diamond cystallization in model systems.Russian Geology and Geophysics, Vol. 56, 1-2, pp. 239-244.TechnologyDiamond morphology
DS201701-0003
2016
Borzdov, Yu.M.Bataleva, Yu.V., Palyanov, Yu.N., Borzdov, Yu.M., Sobolev, N.V.Graphite and diamond formation via the interaction of iron carbide and Fe, Ni sulfide under mantle P-T parameters.Doklady Earth Sciences, Vol. 471, 1, pp. 1144-1148.TechnologyPetrology - experimental

Abstract: Experimental research in the Fe3C-(Fe,Ni)S system was carried out. The objective of the investigation was to model the reactions of carbide-sulfide interaction related to graphite (diamond) formation in reduced lithosphere mantle domains. T ? 1200°C is the formation temperature of the Ni-cohenite + graphite assemblage coexisting with two immiscible melts such as sulfide (Fe60-Ni3-S37)L and metal-sulfide (Fe71-Ni7-S21-C1)L containing dissolved carbon. T ? 1300°C is the generation temperature of a unified melt such as (Fe80-Ni6-S10-C4)L characterized by graphite crystallization and diamond growth. The extraction of carbide carbon during the interaction with the sulfide melt can be considered as one of the potential mechanisms of graphite and diamond formation in the reduced mantle.
DS201812-2778
2018
Borzdov, Yu.M.Bataleva, Yu.V., Palyanov, Yu.N., Borzdov, Yu.M., Novoselov, I.D., Bayukov, O.A., Sobolev, N.V.Conditions of formation of iron-carbon melt inclusions in garnet and orthopyroxene under P-T conditions of lithospheric mantle.Petrology, Vol. 26, 6, pp. 565-574.Mantleredox

Abstract: Of great importance in the problem of redox evolution of mantle rocks is the reconstruction of scenarios of alteration of Fe0- or Fe3C-bearing rocks by oxidizing mantle metasomatic agents and the evaluation of stability of these phases under the influence of fluids and melts of different compositions. Original results of high-temperature high-pressure experiments (P = 6.3 GPa, T = 13001500°?) in the carbideoxidecarbonate systems (Fe3CSiO2(Mg,Ca)CO3 and Fe3CSiO2Al2O3(Mg,Ca)CO3) are reported. Conditions of formation of mantle silicates with metallic or metalcarbon melt inclusions are determined and their stability in the presence of CO2-fluid representing the potential mantle oxidizing metasomatic agent are estimated. It is established that garnet or orthopyroxene and CO2-fluid are formed in the carbideoxidecarbonate system through decarbonation, with subsequent redox interaction between CO2 and iron carbide. This results in the formation of assemblage of Fe-rich silicates and graphite. Garnet and orthopyroxene contain inclusions of a FeC melt, as well as graphite, fayalite, and ferrosilite. It is experimentally demonstrated that the presence of CO2-fluid in interstices does not affect on the preservation of metallic inclusions, as well as graphite inclusions in silicates. Selective capture of FeC melt inclusions by mantle silicates is one of the potential scenarios for the conservation of metallic iron in mantle domains altered by mantle oxidizing metasomatic agents.
DS201901-0006
2018
Borzdov, Yu.M.Bataleva, Yu.V., Palyanov, Yu.N., Borzdov, Yu.M., Bayukov, O.A., Sobolev, N.V.Experiment al modeling of Co forming processes involving cohenite and CO2 fluid in a silicate mantle.Doklady earth Sciences, Vol. 483, 1, pp. 1427-1430.Mantlepetrology

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

Abstract: Of great importance in the problem of redox evolution of mantle rocks is the reconstruction of scenarios of alteration of Fe?- or Fe3C-bearing rocks by oxidizing mantle metasomatic agents and the evaluation of stability of these phases under the influence of fluids and melts of different compositions. Original results of high-temperature high-pressure experiments (P = 6.3 GPa, T = 1300-1500°?) in the carbide-oxide-carbonate systems (Fe3C-SiO2-(Mg,Ca)CO3 and Fe3C-SiO2-Al2O3-(Mg,Ca)CO3) are reported. Conditions of formation of mantle silicates with metallic or metal-carbon melt inclusions are determined and their stability in the presence of CO2-fluid representing the potential mantle oxidizing metasomatic agent are estimated. It is established that garnet or orthopyroxene and CO2-fluid are formed in the carbide-oxide-carbonate system through decarbonation, with subsequent redox interaction between CO2 and iron carbide. This results in the formation of assemblage of Fe-rich silicates and graphite. Garnet and orthopyroxene contain inclusions of a Fe-C melt, as well as graphite, fayalite, and ferrosilite. It is experimentally demonstrated that the presence of CO2-fluid in interstices does not affect on the preservation of metallic inclusions, as well as graphite inclusions in silicates. Selective capture of Fe-C melt inclusions by mantle silicates is one of the potential scenarios for the conservation of metallic iron in mantle domains altered by mantle oxidizing metasomatic agents.
DS201806-1212
2018
Borzdov, Yu.N.Bataleva, Yu.V., Palyanov, Yu.N., Borzdov, Yu.N., Zdrokov, E.V., Novoselov, I.D., Sobolev, N.V.Formation of the Fe, Mg-silicates, FeO, and graphite ( diamond) assemblage as a result of cohenite oxidation under lithospheric mantle conditions.Doklady Earth Sciences, Vol. 479, 1, pp. 335-338.Mantlegraphite

Abstract: Experimental studies in the Fe3C-SiO2-MgO system (P = 6.3 GPa, T = 1100-1500°C, t = 20-40 h) have been carried out. It has been established that carbide-oxide interaction resulted in the formation of Fe-orthopyroxene, graphite, wustite, and cohenite (1100 and 1200°C), as well as a Fe-C-O melt (1300-1500°C). The main processes occurring in the system at 1100 and 1200°C are the oxidation of cohenite, the extraction of carbon from carbide, and the crystallization of metastable graphite, as well as the formation of ferrosilicates. At T ? 1300°C, graphite crystallization and diamond growth occur as a result of the redox interaction of a predominantly metallic melt (Fe-C-O) with oxides and silicates. The carbide-oxide interaction studied can be considered as the basis for modeling a number of carbon-producing processes in the lithospheric mantle at fO2 values near the iron-wustite buffer.
DS202201-0030
2021
Borzdovi, Y.M.Palyanovx, Y.N.,, Borzdovi, Y.M., Kupriyanov, I.N., Khohkhryakov, A.F.,, Nechaev, D.V.Rare - earth metal catalysis for high pressure synthesis of rare diamonds.Nature Communications, https://doi.org/10.1038/s41598-021-88038-5 12p.GlobalREE

Abstract: The combination of the unique properties of diamond and the prospects for its high-technology applications urges the search for new solvents-catalysts for the synthesis of diamonds with rare and unusual properties. Here we report the synthesis of diamond from melts of 15 rare-earth metals (REM) at 7.8 GPa and 1800-2100 °C. The boundary conditions for diamond crystallization and the optimal parameters for single crystal diamond synthesis are determined. Depending on the REM catalyst, diamond crystallizes in the form of cube-octahedrons, octahedrons and specific crystals bound by tetragon-trioctahedron and trigon-trioctahedron faces. The synthesized diamonds are nitrogen-free and belong to the rare type II, indicating that the rare-earth metals act as both solvent-catalysts and nitrogen getters. It is found that the REM catalysts enable synthesis of diamond doped with group IV elements with formation of impurity-vacancy color centers, promising for the emerging quantum technologies. Our study demonstrates a new field of application of rare-earth metals.
DS1993-1626
1993
Bosak, P.Ulrych, J., Pivec, E., Zak, K., Bendl, J., Bosak, P.Alkaline and ultramafic carbonate lamprophyres in Central Bohemian carboniferous basins, Czech republic.Mineralogy and Petrology, Vol. 48, No. 1, pp. 65-83.GlobalAlkaline rocks, Lamprophyres
DS202204-0516
2022
Boscaini, A.Boscaini, A., Marzoli, A., Bertrand, H., Chiagradia, M., Jourdan, F., Faccende, M., Meyzen, C.M., Callegaro, S., Duran, L. Cratonic keels controlled the emplacement of the Central Atlantic Magmatic Province ( CAMP)Earth and Planetary Science Letters, Vol. 584, doi 10.1016/j.espl.2022.117480Africa, Mali, Mauritaniacraton

Abstract: Large Igneous Provinces (LIPs) are exceptionally voluminous magmatic events frequently related to continental break-up, global climate changes and mass extinctions. One interesting aspect of many LIPs is their spatial proximity to cratons, begging the question of a potential control of thick lithosphere on their emplacement. In this study, we investigate the relationship between the emplacement of the Central Atlantic Magmatic Province (CAMP) and the thick lithospheric mantle of the Precambrian cratons that formed the central portion of Pangea and are currently located on the continents surrounding the Central Atlantic Ocean. CAMP outcrops are frequently located over the margins of the thick cratonic keels, as imaged by recent tomographic studies, suggesting a role of lithosphere architecture in controlling magma genesis and emplacement. Here we focus on CAMP dykes and sills from the Hank, Hodh, and Kaarta basins in North-Western Africa (NW-Africa, Mali and Mauritania) emplaced at the edge of the Reguibat and Leo-Man Shields. The investigated intrusive rocks show compositions similar to most CAMP magmas, in particular those of the Tiourjdal geochemical group, limited to NW-Africa, and of the Prevalent group, occurring all over the CAMP. Geochemical modelling of CAMP basalts requires a Depleted MORB Mantle (DMM) source enriched by recycled continental crust (1-4%) and melting beneath a lithosphere of ca. 80 km in thickness. On the contrary, melting under a significantly thicker lithosphere (>110 km) does not produce magmas with compositions similar to those of CAMP basalts. This suggests that CAMP magmatism was likely favoured by decompression-induced partial melting of the upwelling asthenospheric mantle along the steep lithospheric boundaries of stable cratons. The architecture of the pre-existing lithosphere (i.e., the presence of stable thick cratonic keels juxtaposed to relatively thinner lithosphere) appears to have been a critical factor for localizing mantle upwelling and partial melting during extensive magmatic events such as in the CAMP.
DS2001-1150
2001
BoschTardy, M., Lapierre, H/. Struik, Bosch, BrunetThe influence of mantle plume in the genesis of Cache Creek oceanic igneous rocks: geodynamic evolution...Canadian Journal of Earth Sciences, Vol. 38, No. 4, Apr. pp. 515-34.British Columbia, CordilleraMantle plume - not specific to diamonds
DS2002-1356
2002
BoschRolland, Y., Picard, C., Pecher, Lapierre, Bosch, KellerThe Cretaceous Ladakh arc of NW Himalaya slab melting and melt mantle interaction during fast northward driftChemical Geology, Vol.182, 2-4, Feb.15, pp.139-78.India, northwest HimalayasMelting, slab subduction, Indian Plate
DS1996-0157
1996
Bosch, D.Bosch, D., Bruguier, O., Pidgeon, R.T.Evolution of an Archean metamorphic belt: a conventional and SHRIMP uranium-lead (U-Pb)study of accessory mineralJournal of Geology, Vol. 104, No. 6, Nov. pp. 695-711AustraliaYilgarn Craton, Jimperding metamorphic belt
DS1998-0828
1998
Bosch, D.Lapierre, H., Arculus, R., Ballevre, M., Bosch, D.Accreted eclogites with oceanic plateau basalt affinities in EcuadorMineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 852-3.EcuadorRaspas Formation, MetmorphisM., Eclogites
DS2003-0446
2003
Bosch, D.Gasperini, D., Blichert Toft, J., Bosch, D., Del Moro, A., Macera, P., Albaraede, F.Upwelling of deep mantle material through a plate window: evidence from theJournal of Geophysical Research, Vol. 107, 12, Dec. 6, pp. DO1 10.1029/2001JB000418MantleGeophysics - seismics, Tectonics
DS2003-0767
2003
Bosch, D.La Pierre, H., Bosch, D., Tardy, M., Struik, L.C.Late Paleozoic and Triassic plume derived magmas in the Canadian Cordillera played aChemical Geology, Vol. 201, 3-4, Nov. 14, pp. 55-89.British ColumbiaTectonics, Cache Creek, Slide Mountain Terrane, geochem
DS2003-0768
2003
Bosch, D.La Pierre, H., Bosch, D., Tardy, M., Struik, L.C.Late Paleozoic and Triassic plume derived magmas in the Canadian Cordillera played aChemical Geology, Vol. 201, 1-2, pp. 55-89.British Columbia, Yukon, Alberta, Northwest TerritoriesMagmatism, tectonics
DS200412-0614
2003
Bosch, D.Gasperini, D., Blichert Toft, J., Bosch, D., Del Moro, A., Macera, P., Albaraede, F.Upwelling of deep mantle material through a plate window: evidence from the geochemistry of Italian basaltic volcanics.Journal of Geophysical Research, Vol. 107, 12, Dec. 6, pp. DO1 10.1029/2001 JB000418MantleGeophysics - seismics Tectonics
DS200412-1077
2003
Bosch, D.La Pierre, H., Bosch, D., Tardy, M., Struik, L.C.Late Paleozoic and Triassic plume derived magmas in the Canadian Cordillera played a key role in continental crust growth.Chemical Geology, Vol. 201, 1-2, pp. 55-89.Canada, British Columbia, Yukon, Alberta, Northwest TerritoriesMagmatism, tectonics
DS200412-1078
2003
Bosch, D.La Pierre, H., Bosch, D., Tardy, M., Struik, L.C.Late Paleozoic and Triassic plume derived magmas in the Canadian Cordillera played a key role in continental crust growth.Chemical Geology, Vol. 201, 3-4, Nov. 14, pp. 55-89.Canada, British ColumbiaTectonics, Cache Creek, Slide Mountain Terrane, geochem
DS201212-0485
2012
Bosch, D.Monie, P., Bosch, D., Bruguier, O., Vauchez, A., Rolland, Y., Nsungani, P., Buta Neto, A.The Late Neoporterozoic/Early Paleozoic evolution of the West Congo Belt of NW Angola: geochronological (U Pb Ar Ar) and petrostructual constraints.Terra Nova, Vol. 24, 3, pp. 238-247.Africa, AngolaGeochronology
DS201212-0486
2012
Bosch, D.Monie, P., Bosch, D., Bruguier, O., Vauchez, A., Rolland, Y., Nsungani, P., Buta Nto, A.The Late Neoproterozoic/Early Palezoic evolution of the West Congo belt of NW Angola: geochronological (U-Pb and Ar-Ar) and petrostructural constraints.Terra Nova, in press availableAfrica, AngolaGeochronology
DS201312-0265
2013
Bosch, D.Fernandez, L., Bosch, D., Elmessbahi, H., Bodinier, J.L., Dautra, J.M., Verdoux, P.Lithosphere-asthenosphere interactions (Middle Atlas (Morocco): geochemical highlights.Goldschmidt 2013, AbstractAfrica, MoroccoXenoliths
DS201312-0574
2013
Bosch, D.Marchesi, C., Garrido, C.J., Bosch, D., Bodinier, J-L., Gervilla, F., Hidas, K.Mantle refertilization by melts of crustal derived garnet pyroxenite: evidence from the Ronda Peridotite massif, southern Spain.Earth and Planetary Interiors, Vol. 362, pp. 66-75.Europe, SpainRonda - pyroxenite. Melts
DS201412-0088
2014
Bosch, D.Caby, R., Bruguier, O., Fernandez, L., Hammor, D., Bosch, D., Mechati, M., Laouar, R., Ouabadi, A., Abdallah, N., Douchet, C.Metamorphic diamonds in a garnet megacryst from the Edough Massif (northeastern Algeria)… Recognition and geodynamic consequences.Tectonophysics, Vol. 637, pp. 341-353.Africa, AlgeriaEdough Massif
DS201412-0548
2014
Bosch, D.Marchesi, C., Dale, C.W., Garrdo, C.J., Pearson, D.G., Bosch, D., Bodinier, J-L., Gervilla, F., Hidas, K.Fractionation of highly siderophile elements in refertilized mantle: implications for the Os isotope composition of basalts.Earth and Planetary Science Letters, Vol. 400, pp. 33-44.MantleRonda peridotite
DS201704-0650
2016
Bosch, D.Varas-Reu, M.I., Garrido, C.J., Marchesi, C., Bodinier, J-L., Frets, E., Bosch, D., Tommasi, A., Hidas, K., Targuisti, K.Refertilization processes of the subcontinental lithospheric mantle: the record of the Beni Bousera orogenic peridotite ( Rif Belt, northern Morocco).Journal of Petrology, Vol. 57, 11-12, pp. 2251-2270.Africa, MoroccoDeposit - Beni Bousera

Abstract: Correlations between major and minor transition elements in tectonically emplaced orogenic peridotites have been ascribed to variable degrees of melt extraction and melt-rock reaction processes, leading to depletion or refertilization. To elucidate how such processes are recorded in the subcontinental lithospheric mantle, we processed a large geochemical dataset for peridotites from the four tectono-metamorphic domains of the Beni Bousera orogenic massif (Rif Belt, northern Morocco). Our study reveals that variations in bulk-rock major and minor elements, Mg-number and modal mineralogy of lherzolites, as well as their clinopyroxene trace element compositions, are inconsistent with simple partial melting and mainly resulted from different reactions between melts and depleted peridotites. Up to 30% melting at <3 GPa and cryptic metasomatism can account for the geochemical variations of most harzburgites. In Grt-Sp mylonites, melting and melt-rock reactions are masked by tectonic mixing with garnet pyroxenites and subsolidus re-equilibration. In the rest of the massif, lherzolites were mostly produced by refertilization of a refractory protolith (Mg-number = 91, Ol = 70%, Cpx/Opx = 0.4) via two distinct near-solidus, melt- rock reactions: (1) clinopyroxene and orthopyroxene precipitation and olivine consumption at melt/rock ratios <0.75 and variable mass ratio between crystallized minerals and infiltrated melt ®, which are recorded fairly homogeneously throughout the massif; (2) dissolution of orthopyroxene and precipitation of clinopyroxene and olivine at melt/rock ratios <1 and R = 0.2-0.3, which affected mainly the Arie` gite-Seiland and Seiland domains. The distribution of secondary lherzolites in the massif suggests that the first refertilization reaction occurred prior to the differentiation of the Beni Bousera mantle section into petro-structural zones, whereas the second reaction was associated with the development of the tectono-metamorphic domains. Our data support a secondary, refertilization-related origin for most lherzolites in orogenic peridotite massifs.
DS201707-1315
2017
Bosch, D.Chmyz, L., Amaud, N., Biondi, J.C., Azzone, R.G., Bosch, D., Ruberti, E.Ar-Ar ages, Sr-Nd isotope geochemistry and implications for the origin of the silicate rocks of the Jacupiranga ultramafic alkaline complex, Brazil.Journal of South American Earth Sciences, Vol. 77, pp. 286-309.South America, Brazilalkaline - Jacupiringa

Abstract: The Jacupiranga Complex is one of several Meso-Cenozoic alkaline intrusive complexes along the margins of the intracratonic Paraná Basin in southern Brazil. The complex encompasses a wide range of rock-types, including dunites, wehrlites, clinopyroxenites, melteigites-ijolites, feldspar-bearing rocks (diorites, syenites, and monzonites), lamprophyres and apatite-rich carbonatites. While carbonatites have been extensively investigated over the last decades, little attention has been paid to the silicate rocks. This study presents new geochonological and geochemical data on the Jacupiranga Complex, with particular emphasis on the silicate lithotypes. 40Ar/39Ar ages for different lithotypes range from 133.7 ± 0.5 Ma to 131.4 ± 0.5 Ma, while monzonite zircon analyzed by SHRIMP yields a U-Pb concordia age of 134.9 ± 1.3 Ma. These ages indicate a narrow time frame for the Jacupiranga Complex emplacement, contemporaneous with the Paraná Magmatic Province. Most of the Jacupiranga rocks are SiO2-undersaturated, except for a quartz-normative monzonite. Based on geochemical compositions, the Jacupiranga silicate lithotypes may be separated into two magma-evolution trends: (1) a strongly silica-undersaturated series, comprising part of the clinopyroxenites and the ijolitic rocks, probably related to nephelinite melts and (2) a mildly silica-undersaturated series, related to basanite parental magmas and comprising the feldspar-bearing rocks, phonolites, lamprophyres, and part of the clinopyroxenites. Dunites and wehrlites are characterized by olivine compositionally restricted to the Fo83-84 interval and concentrations of CaO (0.13–0.54 wt%) and NiO (0.19–0.33 wt%) consistent with derivation by fractional crystallization, although it is not clear whether these rocks belong to the nephelinite or basanite series. Lamprophyre dikes within the complex are considered as good representatives of the basanite parental magma. Compositions of calculated melts in equilibrium with diopside cores from clinopyroxenites are quite similar to those of the lamprophyres, suggesting that at least a part of the clinopyroxenites is related to the basanite series. Some feldspar-bearing rocks (i.e. meladiorite and monzonite) show petrographic features and geochemical and isotope compositions indicative of crustal assimilation, although this may be relegated to a local process. Relatively high CaO/Al2O3 and La/Zr and low Ti/Eu ratios from the lamprophyres and calculated melts in equilibrium with cumulus clinopyroxene point to a lithospheric mantle metasomatized by CO2-rich fluids, suggesting vein-plus-wall-rock melting mechanisms. The chemical differences among those liquids are thought to reflect both variable contributions of melting resulting from veins and variable clinopyroxene/garnet proportions of the source.
DS201709-1965
2017
Bosch, D.Bruguier, O., Bosch, D., Caby, R., Vitale-Brovarone, A., Fernadez, L., Hammor, D., Laouar, R., Ouabadi, A., Abdallah, N., Mechanti, M.Age of UHP metamorphism in the Western Mediterranean: insight from rutile and minute zircon inclusions in a diamond bearing garnet megacryst ( Edough Massif, NE Algeria).Earth and Planetary Science Letters, Vol. 474, pp. 215-225.Africa, Algeriadiamond inclusions

Abstract: Diamond-bearing UHP metamorphic rocks witness for subduction of lithospheric slabs into the mantle and their return to shallow levels. In this study we present U-Pb and trace elements analyses of zircon and rutile inclusions from a diamond-bearing garnet megacryst collected in a mélange unit exposed on the northern margin of Africa (Edough Massif, NE Algeria). Large rutile crystals (up to 300 ?m in size) analyzed in situ provide a U-Pb age of 32.4 ± 3.3 Ma interpreted as dating the prograde to peak subduction stage of the mafic protolith. Trace element analyses of minute zircons (?30 ?m) indicate that they formed in equilibrium with the garnet megacryst at a temperature of 740-810 °C, most likely during HP retrograde metamorphism. U-Pb analyses provide a significantly younger age of 20.7 ± 2.3 Ma attributed to exhumation of the UHP units. This study allows bracketing the age of UHP metamorphism in the Western Mediterranean Orogen to the Oligocene/early Miocene, thus unambiguously relating UHP metamorphism to the Alpine history. Exhumation of these UHP units is coeval with the counterclockwise rotation of the Corsica-Sardinia block and most likely resulted from subduction rollback that was driven by slab pull.
DS201806-1258
2018
Bosch, D.Varas-Reus, M.I., Garrido, C.J., Marchesi, C., Bosch, D., Hidas, K.Genesis of ultra-high pressure garnet pyroxenites in orogenic peridotites and its bearing on the compositional heterogeneity of the Earth's mantle. Ronda, Beni BouseraGeochimica et Cosmochimica Acta, Vol. 232, pp. 303-328.Africa, Morocco, Europe, SpainUHP

Abstract: We present an integrated geochemical study of ultra-high pressure (UHP) garnet pyroxenites from the Ronda and Beni Bousera peridotite massifs (Betic-Rif Belt, westernmost Mediterranean). Based on their Sr-Nd-Pb-Hf isotopic systematics, we classify UHP garnet pyroxenites into three groups: Group A pyroxenites (Al 2 O 3 : 15-17.5 wt. %) have low initial 87 Sr/ 86 Sr, relatively high ? Nd , ? Hf and 206 Pb/ 204 Pb ratios, and variable 207 Pb/ 204 Pb and 208 Pb/ 204 Pb. Group B pyroxenites (Al 2 O 3 < 14 wt. %) are characterized by high initial 87 Sr/ 86 Sr and relatively low ? Nd , ? Hf and 206 Pb/ 204 Pb ratios. Group C pyroxenites (Al 2 O 3 ~ 15 wt. %) have depleted radiogenic signatures with relatively low initial 87 Sr/ 86 Sr and 206 Pb/ 204 Pb, high ? Nd and ? Hf , and their 207 Pb/ 204 Pb and 208 Pb/ 204 Pb ratios are similar to those of Group B pyroxenites. The major and trace element and isotopic compositions of UHP garnet pyroxenites support their derivation from ancient (1.5-3.5 Ga) oceanic crust recycled into the mantle and intimately stirred with peridotites by convection. However, the genesis of these pyroxenites requires also the involvement of recycled continental lower crust with an isotopic composition akin to the lower crustal section of the lithosphere where these UHP garnet pyroxenites now reside in. These oceanic and continental crustal components were stirred in different proportions in the convective mantle, originating pyroxenites with a more marked geochemical imprint of either oceanic (Group A) or continental lower crust (Group B), or hybrid compositions (Group C). The pyroxenite protoliths likely underwent several melting events, one of them related to the formation of the subcontinental lithospheric mantle and continental crust, generating restitic UHP garnet pyroxenites now preserved in the Ronda and Beni Bousera orogenic peridotites. The extent of melting was mostly 3 controlled by the bulk Mg-number (Mg#) of the pyroxenite protoliths, where protoliths with low Mg# experienced higher degrees of partial melting than sources with higher Mg#. Positive Eu and Sr anomalies in bulk rocks, indicative of their origin from cumulitic crustal gabbros, are preserved mostly in high Mg# pyroxenites due to their higher melting temperatures and consequent lower partial melting degrees. The results of this study show that the genesis of UHP garnet pyroxenites in orogenic peridotites requires a new recipe for the marble cake mantle hypothesis, combining significant recycling and stirring of both oceanic and continental lower crust in the Earth's mantle. Furthermore, this study establishes a firm connection between the isotopic signatures of UHP pyroxenite heterogeneities in the mantle and the continental lower crust.
DS201808-1794
2018
Bosch, D.Varas-Reu, M.I., Garrido, C.J., Marchesi, C., Bosch, D., Hidas, K.Genesis of ultra high pressure garnet pyroxenites in orogenic peridotites and its bearing on the compositional heterogeneity of the Earth's mantle.Geochimica et Cosmochimica Acta, Vol. 232, pp. 303-328.Mantledeposit - Ronda, Beni Bousera

Abstract: We present an integrated geochemical study of ultra-high pressure (UHP) garnet pyroxenites from the Ronda and Beni Bousera peridotite massifs (Betic-Rif Belt, westernmost Mediterranean). Based on their Sr-Nd-Pb-Hf isotopic systematics, we classify UHP garnet pyroxenites into three groups: Group A pyroxenites (Al2O3: 15-17.5?wt.%) have low initial 87Sr/86Sr, relatively high ?Nd, ?Hf and 206Pb/204Pb ratios, and variable 207Pb/204Pb and 208Pb/204Pb. Group B pyroxenites (Al2O3?
DS201905-1021
2019
Bosch, D.Chmyz, L., Arnaud, N., Biondo, J.C., Azzone, R.G., Bosch, D.Hf-Pb isotope and trace element constraints on the origin of the Jacupiranga Complex ( Brazil): insights into carbonatite genesis and multi-stage metasomatism of the lithospheric mantle.Gondwana Research, Vol. 71, pp. 16-27.South America, Brazilcarbonatite

Abstract: The Lower Cretaceous Jacupiranga complex, in the central-southeastern portion of the South American Platform, includes carbonatites in close association with silicate rocks (i.e. strongly and mildly silica-undersaturated series). Here we document the first hafnium isotope data on the Jacupiranga complex, together with new trace element and Pb isotope compositions. Even though liquid immiscibility from a carbonated silicate melt has been proposed for the genesis of several Brazilian carbonatites, isotopic and geochemical (e.g., Ba/La ratios, lack of pronounced Zr-Hf and Nb-Ta decoupling) information argues against a petrogenetic relationship between Jacupiranga carbonatites and their associated silicate rocks. Thus, an origin by direct partial melting of the mantle is considered. The isotopic compositions of the investigated silicate samples are coherent with a heterogeneously enriched subcontinental lithospheric mantle (SCLM) source of rather complex evolution. At least two metasomatic processes are constrained: (1) a first enrichment event, presumably derived from slab-related fluids introduced into the SCLM during Neoproterozoic times, as indicated by consistently old TDM ages and lamprophyre trace signatures, and (2) a Mesozoic carbonatite metasomatism episode of sub-lithospheric origin, as suggested by ?Nd-?Hf values inside the width of the terrestrial array. The Jacupiranga parental magmas might thus derive by partial melting of distinct generations of metasomatic vein assemblages that were hybridized with garnet peridotite wall-rocks.
DS201908-1774
2019
Bosch, D.Chmyz, L., Arnaud, N., Biondi, J.C., Azzone, R.G., Bosch, D.Hf-Pb isotope and trace element constraints on the origin of the Jacupiringa complex ( Brazil): insights into carbonatite genesis and multi-stage metasomatism of the lithospheric mantle.Gondwana Research, Vol. 71, pp. 16-27.South America, Brazilcarbonatite

Abstract: The Lower Cretaceous Jacupiranga complex, in the central-southeastern portion of the South American Platform, includes carbonatites in close association with silicate rocks (i.e. strongly and mildly silica-undersaturated series). Here we document the first hafnium isotope data on the Jacupiranga complex, together with new trace element and Pb isotope compositions. Even though liquid immiscibility from a carbonated silicate melt has been proposed for the genesis of several Brazilian carbonatites, isotopic and geochemical (e.g., Ba/La ratios, lack of pronounced Zr-Hf and Nb-Ta decoupling) information argues against a petrogenetic relationship between Jacupiranga carbonatites and their associated silicate rocks. Thus, an origin by direct partial melting of the mantle is considered. The isotopic compositions of the investigated silicate samples are coherent with a heterogeneously enriched subcontinental lithospheric mantle (SCLM) source of rather complex evolution. At least two metasomatic processes are constrained: (1) a first enrichment event, presumably derived from slab-related fluids introduced into the SCLM during Neoproterozoic times, as indicated by consistently old TDM ages and lamprophyre trace signatures, and (2) a Mesozoic carbonatite metasomatism episode of sub-lithospheric origin, as suggested by ?Nd-?Hf values inside the width of the terrestrial array. The Jacupiranga parental magmas might thus derive by partial melting of distinct generations of metasomatic vein assemblages that were hybridized with garnet peridotite wall-rocks.
DS1960-0428
1964
Bosch, J.L.Bosch, J.L.Die Petrologie Van die Kimberliet Van Bellsbank Mitchelmanskraal, Doornkloof En Sover, Distrik Barkly Wes.Potchefstroom: Msc. Thesis, University Potchefstroom., South Africa, TransvaalPetrology, Kimberlite, Mineralogy
DS1970-0248
1971
Bosch, J.L.Bosch, J.L.The Petrology of Some Kimberlite Occurrences in the Barkly West district, Cape Province.Geological Society of South Africa Transactions, Vol. 74, No. 2, PP. 75-101.South AfricaPetrology
DS200812-0128
2008
Bosch, L.Bosch, L., Becker, T.W., Steinberger, B.On the statistical significance of correlations between synthetic mantle plumes and tomographic models.Physics of the Earth and Planetary Interiors, in press available, 9p.MantleDynamics, plumes, hot spots, tompography
DS1992-0146
1992
Bosch, M.Bosch, M., Rodrigues, I.North Venezuelan collisional crustal block: the boundary between the Caribbean and South American platesJournal of South American Earth Sciences, Vol. 6, No. 3, October pp. 133-144VenezuelaTectonics
DS201607-1331
2016
Bosch, P.Bosch, P.The importance of Dwyka group glaciation with regards to alluvial diamond transportation, concentration and entrapment in South Africa.IGC 35th., Session Mineral Exploration 1p. AbstractAfrica, South AfricaAlluvials, diamonds
DS2003-0136
2003
Boschen, S.Boschen, S., Lenoir, D., Scheringer, M.Sustainable chemistry: starting points and prospectsNaturwissenschaftern, Vol. 90, pp. 93-102.GlobalChemistry - review not specific to diamonds
DS200612-0996
2006
Boscherini, F.Oberti, R., Quartieri, S., Dalconi, M.C., Boscherini, F., Iezzi, G., Boiocchi, M., Eeckhout, S.G.Site preference and local geometry of Sc in garnets: part 1. multifarious mechanisms in the pyrope-grossular join.American Mineralogist, Vol. 91, 9, pp. 1230-1239.TechnologyMineral chemistry - garnets
DS201912-2830
2019
Boschetti, T.Toscani, L., Salvioli-Mariani, E., Mattioli, M., Tellini, C., Boschetti, T., Iacumin, P., Selmo, E.The pyroclastic breccia of the Cabezo Negro de Tallant ( SE Spain): the first finding of carbonatite volcanism in the internal domain of the Betic Cordillera.Lithos, in press available, 16p.Europe, Spaincarbonatite
DS1985-0074
1985
Bosch-Figueroz, J.M.Bosch-Figueroz, J.M.Morphologic Characteristics of Diamonds. *spaGemologia, *SPA., Vol. 23, No. 67-68, pp. 14-22South AfricaBlank
DS200412-0615
2004
Boschi, E.Gasperini, P., DalForno, G., Boschi, E.Linear or non-linear rheology in the Earth's mantle: the prevalence of power law creep in the Post glacial isostatic readjustmentGeophysical Journal International, Vol. 157, 3, pp. 1297-1302.Mantle, LaurentiaTectonics, subduction
DS200512-0202
2005
Boschi, E.Dal Forno, G., Gasperini, P., Boschi, E.Linear or nonlinear rheology in the mantle: a 3 D finite element approach to Post glacial rebound modeling.Journal of Geodynamics, Vol. 39, 2, pp. 183-195.MantleRheology, Laurentia, sea-level
DS2002-0191
2002
Boschi, L.Boschi, L., Ekstrom, G.New images of the Earth's upper mantle from measurements of surface wave phase velocity anomalies.Journal of Geophysical Research, Vol. 107, 4, ESE-1 ( approx. 15 p.)MantleGeophysics - seismics
DS200512-1023
2005
Boschi, L.Soldati, G., Boschi, L.The resolution of whole Earth seismic tomographic models.Geophysical Journal International, Vol. 161, 1, p. 143.MantleGeophysics - seismics
DS200912-0605
2009
Boschi, L.Qin, Y., Capdeville, Y., Montagner, J.P., Boschi, L., Becker, T.W.Reliability of mantle tomography models assessed by spectral element simulation.Geophysical Journal International, Vol. 177, 1, pp. 125-144.MantleTomography
DS201112-0097
2011
Boschi, L.Boschi, L., Kissling, E.Adaptively parametrized surface wave tomography: methodology and a new model of the European upper mantle.Geophysical Journal International, Vol. 186, 3, pp. 1431-1453.Europe, mantleGeophysics - seismics
DS201112-0137
2011
Boschi, L.Cammarano, F., Tackley, P., Boschi, L.Seismic, petrological and geodynamical constraints on thermal and compositional structure of the upper mantle: global thermochemical models.Geophysical Journal International, in press availableMantleGeophysics - seismics
DS201212-0688
2012
Boschi, L.Soldati, G., Boschi, L., Forte, A.M.Tomography of core mantle boundary and lowermost mantle coupled by geodynamics.Geophysical Journal International, Vol. 189, 2, pp. 730-746.MantleGeodynamics
DS201312-0866
2013
Boschi, L.Soldati, G., Koelemeijer, P., Boschi, L., Deuss, A.Constraints on core-mantle boundary topography from normal mode splitting.Geochemistry, Geophysics, Geosystems: G3, Vol. 14, 5, pp. 1333-1342.MantleHeterogeneity
DS202106-0924
2021
Boschi, L.Becker, T., Boschi, L.Multi-scale, radially anisotropic shear wave imaging of the mantle underneath the contiguous United States through joint inversion of USArray and global datasets.Geophysical Journal International, 34p. PdfUnited Statestomography

Abstract: EarthScope's USArray seismic component provided unprecedented coverage of the contiguous United States and has therefore spurred significant advances in tomographic imaging and geodynamic modelling. Here, we present a new global, radially anisotropic shear wave velocity tomography model to investigate upper mantle structure and North American Plate dynamics, with a focus on the contiguous United States. The model uses a data-adaptive mesh and traveltimes of both surface waves and body waves to constrain structure in the crust and mantle in order to arrive at a more consistent representation of the subsurface compared to what is provided by existing models. The resulting model is broadly consistent with previous global models at the largest scales, but there are substantial differences under the contiguous United States where we can achieve higher resolution. On these regional scales, the new model contains short wavelength anomalies consistent with regional models derived from USArray data alone. We use the model to explore the geometry of the subducting Farallon Slab, the presence of upper mantle high velocity anomalies, low velocity zones in the central and eastern United States and evaluate models of dynamic topography in the Cordillera. Our models indicate a single, shallowly dipping, discontinuous slab associated with the Farallon Plate, but there are remaining imaging challenges. Inferring dynamic topography from the new model captures both the long-wavelength anomalies common in global models and the short-wavelength anomalies apparent in regional models. Our model thus bridges the gap between high-resolution regional models within the proper uppermost mantle context provided by global models, which is crucial for understanding many of the fundamental questions in continental dynamics.
DS201909-2023
2019
Bosco-Santos, A.Bosco-Santos, A., Gilholy, W.P., Fouskas, F., Baldim, M., Oliveira, E.P.Ferruginous - euxinc - oxic: a three step redox change in the Neoarchean record.Goldschmidt2019, 1p. AbstractSouth America, Brazilcraton

Abstract: Much of the secular record of sulfur mass independet fractionation (S-MIF) is based on pyrites extracted from a limited number of formations from Western Australia and Southern Africa. Here we present multiproxy evidence for an episodic loss of S-MIF in sulfides from a 2.7 Ga sedimentary record in the São Francisco craton, Brazil. Based on combined proxies, we assigned three phases, in a continous drill core, that track evolving water column redox conditions and changes in ecology. In Phase-I, the stratigraphically older rocks, reactive iron ratios suggest ferruginous conditions. The pyrites have modest S-MIF values (D33S from -0.7 to 2.6‰) and the carbon isotope composition of the iron formations is indicative of carbon fixation by anoxygenic photosynthetic bacteria that oxidized Fe2+ (d13Corg from -27.7 to -17.5‰). Within Phase-II, an intermediate phase characterized by graphite schist, the iron ratios, expansion of the S-MIF (D33S from 2.15 to 3.4‰) and an excess of Mo relative to Corg suggest deposition in an anoxic environment with periodic development of euxinic conditions. Phase-III culminates in fully oxic conditions with a loss of S-MIF and emergence of sulfur mass dependent fractionation (S-MDF) with homogeneous d34S pyrite values (average = 3.3 ± 0.5‰). The loss of S-MIF in the Archean sulfides of Phase-III was interpreted as a response to increased oxygen levels that lead to an intensification of oxidative weathering. Based on the continous deposition within this drillcore, the development of more oxidizing conditions may have been relatively rapid, reinforcing the model that the transition from S-MIF to S-MDF can happen on rapid geological time scales and was recorded about 400 million years prior to the GOE in the Brazilian craton.
DS200912-0064
2009
Bose, M.K.Bose, M.K.Precambrian mafic magmatism in the Singhbhum Craton, eastern India.Journal of the Geological Society of India, Vol. 73, 1, pp. 13-35.IndiaMagmatism
DS2000-0637
2000
Bose, P.K.Mazumder, R., Bose, P.K., Sarkar, S.A commentary on the tectono sedimentary record of the pre 2.0 Ga continental growth of India vis a vis ...Journal of African Earth Sciences, Vol. 30, No. 2, Feb. pp. 201-18.IndiaGondwana Afro-India supercontinent, Tectonics
DS2000-0638
2000
Bose, P.K.Mazumder, R., Bose, P.K., Sarkar, S.A commentary of the tecton-sedimentary record of pre 2.0 Ga continental growth of India..vis a vis pre-Journal of African Earth Sciences, Vol. 30, No. 2, pp. 201-17.IndiaTectonics - Gondwana Afro-Indian supercontinent
DS1989-0147
1989
Bose, R.M.Bose, R.M.A quantitative chemical classification of the igneous rocksIndian Minerals, Vol. 43, No. 1, January-March pp. 47-55IndiaIgneous rocks, Classification -chemical
DS201112-0098
2011
Bose, S.Bose, S., Dunkley, D.J., Dasgupta, S., Das, K., Arima, M.India-Antarctica-Australia-Laurentia connection in the Paleoproterozoic-Mesoproterozoic revisited: evidence from new zircon U Pb and monzazite chemical age dataGeological Society of America Bulletin, Vol. 123, 9/10 pp. 2031-2049.IndiaEastern Ghats Belt, geochronology
DS1986-0090
1986
Bosellini, A.Bosellini, A.East Africa continental marginsGeology, Vol. 14, No. 1, January pp. 76-78East AfricaTectonics
DS200812-0129
2008
Boser, U.Boser, U.Diamonds on demand.Smithsonian, Vol. 39, 3, June pp. 52-59.TechnologyLab-grown diamonds, Appolo synthesis
DS1980-0249
1980
Boshier, P.R.Nash, C.R., Boshier, P.R., Coupard, M.M., Theron, A.C., Wilson.Photogeology and Satellite Image Interpretation in Mineral Exploration.Minerals Sci. Eng., Vol. 12, No. 4, PP. 216-244.Australia, South Africa, South AustraliaKimberlite, Tectonics, Regional Geology, Gawler Craton
DS200712-0095
2007
Boshoff, E.T.Boshoff, E.T., Morkel, J., Vermaak, M.K., Pistorius, P.C.Kimberlite degradation: the role of cation type.Minerals Engineering, Vol. 20, 15, pp. 1351-1359.TechnologyMining
DS201610-1847
2014
Boshoff, E.T.Boshoff, E.T.Identifying critical parameters in the settling of African kimberlite slimes.Thesis, University of Pretoria, Ms Metallurgical Engineering 279p. PdfAfrica, Angola, South AfricaDeposit - AC 56-5-1, Venetia Red

Abstract: Kimberlite is the host rock from which diamonds are mined. The mineralogical features for kimberlites vary greatly with country, origin, depth and type of kimberlite. Kimberlites can contain various clay species with some kimberlites containing predominantly clay minerals. The presence of these clay minerals in the ore can cause difficulty in dewatering due to high flocculant demand, poor supernatant clarity and low settling rates. Identifying critical parameters that can predict the settling behaviour of African kimberlite slurries will assist the process engineer to predict the settling behaviour of different kimberlite slurries. Especially identifying the kimberlites that will most likely not settle with normal flocculant dosage rates is useful. From first principles the settling of a particle is described by Stoke’s law which incorporates the density of the particle and size of the particle as the inherent particle variables. In this case density is assumed constant and therefore the size of particles influence the settling rate of particles to a great extent. This study therefore investigated the influence of particle size on settling rate and whether the particle size distribution showed correlation with settling rate when regression modelling was fitted on the data. Other variables that were tested for correlation with settling were pH when the kimberlite is mixed in water as well as various mineralogical features of the ore. Fitting a simple model to any of these properties or combinations of these properties was attempted which would allow for prediction of settling behaviour. The mineralogical features were classified by evaluating the mineral composition, fractional elemental analysis, cation exchange capacity and the exchangeable sodium percentage of the different kimberlites. These variables were tested as well as their settling behaviour with 18 different African kimberlite samples. The settling rate and slurry bed compaction during natural settling as well coagulant and flocculant assisted settling were measured for the kimberlite slurries. The best performing coagulant and flocculant for each kimberlite were combined to evaluate potential improvements in the settling rates and slurry bed compaction compared to current settling practices that only utilise flocculant additions. Especially the use of coagulant for kimberlites that did not show settling with only flocculants was evaluated. For these 18 kimberlites only 2 kimberlites did not settle with the use of flocculants with settling rates varying between 10.7m/h and 25m/h. Both these kimberlites also did not settle with the combination of coagulant and flocculant, but could only settle with only coagulant additions at settling rates of 1.9 m/h and 2.2 m/h. Regression analysis fitted to the settling rate investigated the influence of particle size, pH and mineralogical features on settling. For representation of the particle size two data points from the Particle Size Distribution (PSD) was utilised which represented the fine material and the coarser material. These two data points were taken at percentage passing 7.5 ?m and 75 ?m. Regression data for kimberlite with flocculant additions showed that particle size and the pH of the slurry were identified as significant parameters in predicting settling. The regression data showed a R2 of 0.78 for the settling rate and an adjusted R2 of 0.79 for the slurry bed depth.
DS201809-1998
2018
Boshoff, E.T.Boshoff, E.T., Morkel, J., Naude, N.Identifying critical parameters in the settling of African kimberlites. SlurriesMineral Processing and Extractive Metallurgy Review, Vol. 39, pp. 136-144.Africa, Angolamineral processing

Abstract: Kimberlite is the host rock of diamonds and varies widely in geological and mineralogical features as well as color, processing capability, and dewatering characteristics. This study investigated the dewatering behavior of problematic Angolan kimberlites. The presence of clay minerals in kimberlite causes difficulties in dewatering due to high flocculant demand, poor supernatant clarity, and low settling rates. Identifying critical parameters governing the settling behavior will assist in managing the settling behavior of different kimberlite slurries. The influence of particle size, pH of the kimberlite slurry, cation exchange capacity, exchangeable sodium percentage, and smectite content of the kimberlite on the settling rate were investigated for 18 different African kimberlite samples. The settling rate and slurry bed compaction during natural settling were also measured for the kimberlite slurries. Seventeen different Angolan clay-rich kimberlites and one South African clay-rich kimberlite were tested, and, except for two kimberlites, colloidal stability was experienced during natural settling. The pH values of the kimberlite slurries ranged between 9 and 11, which is similar to the pH band where colloidal stability was found during earlier research. The results indicate that colloidal stable slurries were experienced with kimberlites that had exchangeable sodium percentages as low as 0.7%. The cation exchange capacity of the various kimberlites differentiated more distinctly between colloidal stability and instability. A new model is proposed whereby clay-rich kimberlites with a cation exchange capacity of more than 10cmol/kg will experience colloidal stability if the pH of the solvent solution is within the prescribed pH range of 9-11.
DS201605-0831
2016
Boshoff, P.Du Toit, D., Meno, T., Telema, E., Boshoff, P., Hodder, A.Survey systems adopted to improve safety and efficiency at Finsch diamond mine.Diamonds Still Sparkling SAIMM 2016 Conference, Mar. 14-17, pp. 187-196.Africa, South AfricaDeposit - Finsch
DS201605-0862
2016
Boshoff, P.Luther, M., Boshoff, P.Longhole drilling and blasting at Finsch diamond mine.Diamonds Still Sparkling SAIMM 2016 Conference, Mar. 14-17, pp. 317-332.Africa, South AfricaDeposit - Finsch
DS201605-0913
2016
Boshoff, P.Van Strijp, T., Boshoff, P., du Toit, R.How the mining design evolved through stress and deformation modelling at Finsch diamond mine.Diamonds Still Sparkling SAIMM 2016 Conference, Mar. 14-17, pp. 251-262.Africa, South AfricaDeposit - Finsch
DS201412-0675
2014
Bosi, F.Perlinelli, C., Bosi, F., Andreozzi, G.B., Conte, A.M., Armienti, P.Geothermometric study of Cr-spinels of peridotite mantle xenoliths from northern Victoria Land ( Antarctica).American Mineralogist, Vol. 99, pp. 839-846.AntarcticaSpinel
DS201312-0087
2013
Boskabadi, A.Boskabadi, A., Pitcairn, I.K., Stern, R.J., Azer, M.K., Broman, C., Mohamed, F.H., Majka, J.Carbonatite crystallization and alteration in the Tarr carbonatite-albitite complex, Sinai Peninsula, Egypt. ( Arabian-Nubian shield)Precambrian Research, Vol. 239, pp. 24-41.Africa, EgyptCarbonatite
DS201412-0060
2014
Bosman, J.Bosman, J.The art and science of dense medium selection.South African Institute of Mining and Metallurgy, Vol. 114, July pp. 529-536.TechnologyDMS overview
DS201412-0204
2014
Bosq, C.Doucelance, R., Bellot, N., Boyet, M., Hammouda, T., Bosq, C.What coupled cerium and neodynium isotopes tell us about the deep source of oceanic carbonatites.Earth and Planetary Science Letters, Vol. 407, pp. 175-195.Europe, Cape Verde Islands, Africa, MoroccoCarbonatite
DS1990-0224
1990
Bosse, J.Bosse, J.Les lamprophyres de la region du lac Shortt. Projet de fin d'etudesUniversity of du Quebec a Montreal, 39p.QuebecDikes - lamprophyre, Deposit - Lac Shortt
DS1991-0159
1991
Bosse, J.Bourne, J.H., Bosse, J.Geochemistry of ultramafic and calc-alkaline lamprophyres from the Lac Shortt area, QuebecMineralogy and Petrology, Vol. 45, No. 2, pp. 85-104QuebecGeochemistry, Alkaline rocks, lamprophyres
DS201412-0061
2014
Bosshard-Stadlin, S.A.Bosshard-Stadlin, S.A., Mattsson, H.B., Keller, J.Magma mixing and forced exsolution of CO2 during the explosive 2007-8 eruption of Oldoinyo Lengai ( Tanzania).Journal of Volcanology and Geothermal Research, Vol. 285, pp. 229-246.Africa, TanzaniaMagmatism
DS201412-0062
2014
Bosshard-Stadlin, S.A.Bosshard-Stadlin, S.A., Mattsson, H.B., Keller, J.Magma mixing and forced exsolution of CO2 during the explosive 2007-2008 eruption of Oldoinyo Lengai ( Tanzania).Journal of Volcanology and Geothermal Research, Vol. 285, pp. 229-246.Africa, TanzaniaCarbonatite
DS201710-2216
2017
Bosshard-Stadlin, S.A.Bosshard-Stadlin, S.A., Mattsson, H.B., Stewart, C., Reusser, E.Leaching of lava and tephra from the Oldoinyo Lengai volcano ( Tanzania): remobilization of fluorine and other potentially toxic elements in surface waters of the Gregory Rift.Journal of Volcanology and Geothermal Research, Vol. 322, pp. 14-25.Africa, Tanzaniadeposit - Oldoinyo Lengai

Abstract: Volcanic ash leachate studies have been conducted on various volcanoes on Earth, but few have been done on African volcanoes until now. Tephra emissions may affect the environment and the health of people living in this area, and therefore we conducted a first tephra (ash and lapilli sized) leachate study on the Oldoinyo Lengai volcano, situated in northern Tanzania. The recent explosive eruption in 2007-2008 provided us with fresh samples from the first three weeks of the eruption which were used for this study. In addition, we also used a natrocarbonatitic sample from the activity prior to the explosive eruption, as the major activity at Oldoinyo Lengai is natrocarbonatitic. To compare the leaching process affecting the natrocarbonatitic lavas and the tephras from Oldoinyo Lengai, the 2006 natrocarbonatitic lava flow was resampled 5 years after the emplacement and compared to the initial, unaltered composition. Special interest was given to the element fluorine (F), since it is potentially toxic to both humans and animals. A daily intake of fluoride (F?) in drinking water of > 1.5 mg/l can lead to dental fluorosis, and higher concentrations lead to skeletal fluorosis. For this reason, a guideline value for fluoride in drinking water was set by the WHO (2011) to 1.5 mg/l. However, surface waters and groundwaters in the Gregory Rift have elevated fluoride levels of up to 9.12 mg/l, and as a consequence, an interim guideline value for Tanzania has been set at 8 mg/l. The total concentration of fluorine in the samples from the natrocarbonatitic lava flow is high (3.2 wt%), whereas we observed a significant decrease of the fluorine concentration (between 1.7 and 0.5 wt%) in the samples collected three days and three weeks after the onset of the explosive 2007-08 eruption. However, the total amount of water-extractable fluoride is lower in the natrocarbonatitic lavas (319 mg/l) than in the nephelinitic tephra (573-895 mg/l). This is due to the solubility of the different F-bearing minerals. In the natrocarbonatites, fluorine exists predominantly in fluorite (CaF2), and in the early tephra as Na-Mg bearing salts such as neighborite (NaMgF3) and sellaite (MgF2). All these three minerals have very low solubility in water (16-130 mg/l). The later nephelinitic tephras contain surface coating of villiaumite (NaF), which is highly soluble (42,200 mg/l) in water and can thus release the fluoride more readily upon contact with water. Although there is still the need for further data and a more precise study on this topic in Tanzania, we can already draw a first conclusion that the intake of water during or directly following the deposition of the tephra is not advisable and should be avoided, whereas the release of fluoride from the lava flow has less influence on the river waters.-
DS201805-0961
2018
Bosshard-Stadlin, S.A.Mattsson, H.B., Balashova, A., Almqvist, S.A., Bosshard-Stadlin, S.A., Weidendorfer, D.Magnetic mineralogy and rock properties of silicate and carbonatite rocks from Oldoinyo Lengai volcano (Tanzania).Journal of African Earth Sciences, Vol. 142, pp. 193-206.Africa, Tanzaniadeposit - Oldoinyo Lengai

Abstract: Oldoinyo Lengai, a stratovolcano in northern Tanzania, is most famous for being the only currently active carbonatite volcano on Earth. The bulk of the volcanic edifice is dominated by eruptive products produced by silica-undersaturated, peralkaline, silicate magmas (effusive, explosive and/or as cumulates at depth). The recent (2007-2008) explosive eruption produced the first ever recorded pyroclastic flows at this volcano and the accidental lithics incorporated into the pyroclastic flows represent a broad variety of different rock types, comprising both extrusive and intrusive varieties, in addition to various types of cumulates. This mix of different accidental lithics provides a unique insight into the inner workings of the world's only active carbonatite volcano. Here, we focus on the magnetic mineralogy and the rock magnetic properties of a wide selection of samples spanning the spectrum of Oldoinyo Lengai rock types compositionally, as well from a textural point of view. Here we show that the magnetic properties of most extrusive silicate rocks are dominated by magnetite-ulvöspinel solid solutions, and that pyrrhotite plays a larger role in the magnetic properties of the intrusive silicate rocks. The natrocarbonatitic lavas, for which the volcano is best known for, show distinctly different magnetic properties in comparison with the silicate rocks. This discrepancy may be explained by abundant alabandite crystals/blebs in the groundmass of the natrocarbonatitic lavas. A detailed combination of petrological/mineralogical studies with geophysical investigations is an absolute necessity in order to understand, and to better constrain, the overall architecture and inner workings of the subvolcanic plumbing system. The results presented here may also have implications for the quest in order to explain the genesis of the uniquely natrocarbonatitic magmas characteristic of Oldoinyo Lengai.
DS1989-0148
1989
Bosshart, G.Bosshart, G.The Dresden GreenJournal of Gemology, Vol. 21, No. 6, pp. 351-362GlobalDiamond research, Spectroscopy
DS1999-0083
1999
Bosshart, G.Bosshart, G., Smith, C.P.Synthetic blue diamonds hit the marketRapaport Diamond Report, Vol. 22, No. 20, June 4, pp. 114-6.GlobalReview - Gems and Gemology Fall 2000 p. 285., Diamond synthetics
DS2000-0903
2000
Bosshart, G.Smith, C.P., Bosshart, G., Pnahlo, Hammer, KlapperGE POL diamonds: before and after. Type 11a and HPHT annealing .Gems and Gemology., Vol. 36, Fall, pp. 192-215.GlobalDiamond - enhancement, colour change, Cathodluminescence, photoluminescence
DS2002-1510
2002
Bosshart, G.Smith, C.P., Bosshart, G.Star of the South: a historic 128 ct diamondGems & Gemology, Vol.38,1, pp. 54-65., Vol.38,1, pp. 54-65.BrazilHistory, diamond morphology, diamonds notable
DS2002-1511
2002
Bosshart, G.Smith, C.P., Bosshart, G.Star of the South: a historic 128 ct diamondGems & Gemology, Vol.38,1, pp. 54-65., Vol.38,1, pp. 54-65.BrazilHistory, diamond morphology, diamonds notable
DS201012-0065
2010
Bosshart, G.Bosshart, G., Chapman, J.G.2010 The Argyle diamond mine in transition from open pit to underground extraction.The Australian Gemmologist, Vol. 24, 1,AustraliaDeposit - Argyle
DS201212-0082
2010
Bosshart, G.Bosshart, G., Chapman, J.G., Payne, C., Bauer, R.The Argyle diamond mine in transition from open pit to underground extraction: differing causes of colour in diamond. The Australian Gemmologist, Vol. 24, 1, Jan-March pp,AustraliaDeposit - Argyle
DS201511-1825
2014
Bosshart, G.Bosshart, G., Chapman, J.The Argyle diamond mine in transition from open pit to underground extraction.Australian Gemmologist, Vol. 24, 1, pp. 4-8.AustraliaDeposit - Argyle

Abstract: At the Argyle diamond mine in Western Australia, an underground project is using block caving techniques to reach deeper portions of the diamondiferous lamproite. This program could extend the life of the mine to 2018. It entails a high level of automation, as well as measures to combat monsoonal downpours.
DS2001-0437
2001
BossiHalls, H.C., Campal, Davis, BossiMagnetic studies and uranium-lead (U-Pb) geochronology of the Uruguyuan dyke swarm, Rio de la Plat a Craton: paleomagJournal of South American Earth Sciences, Vol. 14, No. 4, Sept. pp. 349-61.UruguayGeophysics - magnetics, Dike swarms
DS1993-0139
1993
Bossi, J.Bossi, J., Camapl, N., Civetta, L., Demarchi, G.Early Proterozoic dike swarms from western Uruguay- geochemistry, isotopes and petrogenesisChemical Geology, Vol. 106, No. 3-4, June 25, pp. 263-277UruguayDike swarms, geochemistry, Geochronology
DS1993-0140
1993
Bossi, J.Bossi, J., Campal, N., Civetta, L., et al.Early Proterozoic dike swarms from western Uruguay: geochemistry, Strontium and neodymium isotopes and petrogenesisChemical Geology, Vol. 106, pp. 263-277UruguayDikes, Basalts, petrology
DS201012-0218
2010
Bossi, J.Gaucher, C., Frei, R., Chemale, F.Jr., Frei, D., Bossi, J., Martinez, G., Chiglino, L., Cernuschi, F.Mesoproterozoic evolution of the Rio de la Plat a Craton in Uruguay: at the heart of Rodinia?International Journal of Earth Sciences, In press available, 16p.South America, UruguayTectonics - not specific to diamonds
DS201112-0347
2011
Bossi, J.Gaucher, C., Frei, R., Chemale, F., Frei, D., Bossi, J., Martinez, G., Chiglino, L., Cernuschi, F.Mesoproterozoic evolution of the Rio de la Plat a craton in Uruguay: at the heart of Rodinia?International Journal of Earth Sciences, Vol. 100, 2, pp. 273-288.South America, UruguayCraton, Rodinia, Gondwana
DS201904-0718
1991
Bossi, J.Bossi, J., Campal, N., Civetta, L., Demarchi, G., Girardi, V.V., Mazzucchelli, M., Piccirillo, E.M., Rivalenti, G., Sinigol, S., Teixeira, W., Fragoso-Cesar, A.R.Petrological and geochronological aspects of the Precambrian mafic dyke swarm of Uruguay. IN: Eng. Note Date****BOL.IG-USP, Publ.Esp., Vol. 10, pp. 35-42.South America, Uruguaydykes

Abstract: The subparallel maflc dykes of the Aorida-Durazno-S.José region (SW Uruguay) trend N60-80W and vary in thickness from 0.6 to 50 m. They are part of the mafic dyke swarms intrudlng granitic-gnelssic basement that were mappecl by BOSSI et ai. (1989), In an ares approximately 200 km In length and 100 km in bresdth. Plagioclass, augite, subcalclc augite (plgeonite) and opaques are the maln components of the dykes. Orthopyroxene and oIlvine are very rare. Blotite and homblende are secondary minerais. Quartz-feldspar Intergrowths occur In the coarser gralnecl dykes. The characterlstlc textures are subophitic and intersertal.
DS2003-0137
2003
Bostick, B.C.Bostick, B.C., Jones, R.E., Ernst, W.G., Chen, C., Leech, M.L., Beane, R.J.Low temperature microdiamond aggregates in the Maksyutov metamorphic complexAmerican Mineralogist, Vol. 88, pp. 1709-17.Russia, UralsGeochemistry
DS200412-0185
2003
Bostick, B.C.Bostick, B.C., Jones, R.E., Ernst, W.G., Chen, C., Leech, M.L., Beane, R.J.Low temperature microdiamond aggregates in the Maksyutov metamorphic complex, South Ural Mountains, Russia.American Mineralogist, Vol. 88, pp. 1709-17.Russia, UralsGeochemistry
DS1980-0070
1980
Bostock, H.Bostock, H.Geology of the Itchen Lake Area, District of MackenzieGeological Survey of Canada (GSC) Memoir, No. 391, 101p. map 1473A.Northwest TerritoriesGeology
DS1960-0877
1967
Bostock, H.H.Sanford, B.V., Norris, A.W., Bostock, H.H.Geology of the Hudson Bay LowlandsGeological Survey of Canada Paper, No. 67-60OntarioHudson Bay Area
DS1994-0187
1994
Bostock, H.H.Bostock, H.H., Van Breemen, O.Ages of detrital and metamorphic zircons, monazites a pre-Taltson magmatic zone basin w edge of Rae Province.Canadian Journal of Earth Sciences, Vol. 31, No. 8, August, pp. 1353-1364.Northwest TerritoriesGeochronology, tectonics, craton, Rae Province
DS1996-0695
1996
Bostock, M.Jones, A.G., Eaton, D.W., White, D., Bostock, M., MareschalGeophysical measurements for lithospheric parametersGeological Survey of Canada, LeCheminant ed, OF 3228, pp. 243-250.Canada, mantleGeophysics -seismics, Lithosphere
DS1998-1334
1998
Bostock, M.Shi, L., Francis, D., Bostock, M.Xenolith evidence for lithospheric melting above anomalously hot mantle under the northern Cordillera.Contributions to Mineralogy and Petrology, Vol. 131, No. 1, pp. 39-53.Canada, Northwest TerritoriesXenoltihs
DS2001-0125
2001
Bostock, M.Bostock, M.Imaging the lithospheric mantle using seismological methodsKegs Diamond Short Course, Prospectors And Developers Association Of Canada (pdac)., MantleGeophysics - seismics
DS200512-0779
2005
Bostock, M.Nicholson, T., Bostock, M., Cassidy, J.F.New constraints on subduction zone structure in northern Cascadia.Geophysical Journal International, Vol. 161, 3, June pp. 849-859.Canada, British ColumbiaTectonics
DS1998-0142
1998
Bostock, M.C.Bostock, M.C.Mantle stratigraphy and evolution of the Slave ProvinceJournal of Geophysical Research, Vol. 103, No. 9, Sept. 10, pp. 21, 183-200.Northwest TerritoriesStratigraphy, Slave Province, Tectonics
DS1997-0115
1997
Bostock, M.GBostock, M.G, mCassidy, J.F.Upper mantle stratigraphy beneath the southern Slave CratonCanadian Journal of Earth Sciences, Vol. 34, No. 5, May pp. 577-587Northwest TerritoriesCraton, Stratigraphy
DS1991-0152
1991
Bostock, M.G.Bostock, M.G.Seismology of the continental lithosphereProspectors and Developers Association of Canada (PDAC) Short Course, KEGS diamond workshop, 22p.Northwest Territories, AustraliaGeophysics - seismics, tomography, Technology - techniques, methodology
DS1995-0176
1995
Bostock, M.G.Bostock, M.G.A seismic image of the upper mantle beneath the North American CratonEos, Vol. 76, No. 46, Nov. 7. p.F383. Abstract.Mantle, North AmericaGeophysics -seismic, Mantle stratigraphy
DS1996-0416
1996
Bostock, M.G.Ellis, R.M., Hajnal, Z., Bostock, M.G.Seismic studies on the Trans Hudson Orogen of western CanadaTectonophysics, Vol. 262, pp. 35-50.SaskatchewanGeophysics - seismics, Trans Hudson Orogeny, kimberlites
DS1997-0073
1997
Bostock, M.G.Bank, C.G., Bostock, M.G., Ells, R.M., VanDecar, HajnalLithospheric mantle structure beneath the Trans Hudson Orogen from teleseismic travel time inversion.Lithoprobe Report, No. 62, pp. 6-9.ManitobaGeophysics - seismics, Tectonics
DS1997-0114
1997
Bostock, M.G.Bostock, M.G.Anisotropic upper mantle stratigraphy and architecture of the SlaveCratonNature, Vol. 390, No. 6658, Nov. 27, pp. 392-394Northwest TerritoriesCraton, Tectonics
DS1997-0116
1997
Bostock, M.G.Bostock, M.G., Cassify, J.F.Upper mantle stratigraphy beneath the southern Slave CratonCanadian Journal of Earth Sciences, Vol. 34, No. 5, May pp. 577-587.Northwest TerritoriesMantle, Stratigraphy
DS1998-0074
1998
Bostock, M.G.Bank, C.G., Bostock, M.G., VanDecar, J.C.Lithospheric mantle structure beneath the Trans Hudson Orogen and The origin of Diamondiferous kimberlitesá#2Journal of Geophysical Research, Vol. 103, No. 5, May 10, pp. 10103-114.Saskatchewan, Manitoba, Northwest TerritoriesKimberlites, Trans Hudson Orogen
DS1998-0224
1998
Bostock, M.G.Cassidy, J.F., Bostock, M.G.Crustal structure of the Archean Slave Craton from receiver functionstudies.Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) Abstract Volume, p. A28. abstract.Northwest TerritoriesGeophysics - seismics, Slave Craton
DS1998-0391
1998
Bostock, M.G.Ellis, R.M., Bostock, M.G., Bank, C.G.Lithospheric mantle structure beneath the Trans Hudson Orogen and The origin of Diamondiferous kimberlites #1Geological Association of Canada (GAC)/Mineralogical Association of, p. A50. abstract.SaskatchewanGeophysics - seismics, Trans Hudson Orogen
DS1998-0443
1998
Bostock, M.G.Fredericksen, A.W., Bostock, M.G., Cassidy, J.F.Seismic structure of the upper mantle beneath the northern Cordillera -teleseismic travel time inversionTectonophysics, Vol. 294, No. 1-2, Aug. 30, pp. 43-56.Cordillera, Yukon, mantleGeophysics - seismics, Tectonics
DS1999-0084
1999
Bostock, M.G.Bostock, M.G.Seismic imaging of lithospheric discontinuities and continental evolutionLithos, Vol. 48, No. 1-4, Sept. pp. 1-16.MantleGeophysics - seismics, Tectonics - Discontinuity
DS2000-0102
2000
Bostock, M.G.Bostock, M.G.Continental roots, diamonds and Earth's early evolutionGeolog, Vol. 29, pt.2, Summer, pp.12, 13.MantleTectonics - structure, Geophysics - seismics
DS2000-0827
2000
Bostock, M.G.Rondenay, S., Bostock, M.G., Ellis, R.M.Lithospheric assembly and modification of the southeast Canadian Shield: Abitibi Grenville teleseismic exper.Journal of Geophysical Research, Vol. 105, No. 6, June 10, pp. 13735-54.Ontario, QuebecGeophysics - seismics, Tectonics
DS2001-0333
2001
Bostock, M.G.Fredericksen, A.W., Bostock, M.G., Cassidy, J.F.S wave velocity structure of the Canadian upper mantlePhysical Earth and Planetary Interiors, Vol. 124, No. 3-4, Aug. pp. 175-191.Mantle, Canada, Northwest TerritoriesGeophysics - seismics, Cratonic keel
DS2001-1094
2001
Bostock, M.G.Snyder, D.B., Asudeh, I., Bostock, M.G., Lockhart, G.D.Ongoing teleseismic studies of the Slave Craton29th. Yellowknife Geoscience Forum, Nov. 21-23, abstract p. 78.Northwest Territories, Saskatchewan, AlbertaGeophysics - seismics
DS2002-0192
2002
Bostock, M.G.Bostock, M.G., Hyndman, R.D., Rondenay, S., Peacock, S.M.An inverted continental MOHO and serpentinization of the forearc mantleNature, No. 6888, May 3o, pp.536-7.MantleBoundary
DS2002-1477
2002
Bostock, M.G.Shragge, J., Bostock, M.G., Bank, C.G., Ellis, R.M.Integrated teleseismic studies of the southern Alberta upper mantleCanadian Journal of Earth Science, Vol.39,3,Mar.pp.399-411., Vol.39,3,Mar.pp.399-411.AlbertaGeophysics - seismics, Hearne Province, Tectonics
DS2002-1478
2002
Bostock, M.G.Shragge, J., Bostock, M.G., Bank, C.G., Ellis, R.M.Integrated teleseismic studies of the southern Alberta upper mantleCanadian Journal of Earth Science, Vol.39,3,Mar.pp.399-411., Vol.39,3,Mar.pp.399-411.AlbertaGeophysics - seismics, Hearne Province, Tectonics
DS2002-1479
2002
Bostock, M.G.Shragge, J., Bostock, M.G., Bank,. C.G., Ellis, R.M.Integrated teleseismic studies of the southern Alberta upper mantleCanadian Journal of Earth Sciences, Vol. 39, No. 3, pp.399-411.AlbertaGeophysics - seismics
DS2002-1519
2002
Bostock, M.G.Snyder, D.B., Bostock, M.G., Lockhart, G.D.Mantle layers in the Slave Craton30th. Yellowknife Geoscience Forum, Abstracts Of Talks And Posters, Nov. 20-22, p. 63. abstractNorthwest TerritoriesGeophysics - seismics, discontinuity
DS2003-0068
2003
Bostock, M.G.Bank, C.G., Bostock, M.G.Linearized inverse scattering of teleseismic waves for anisotropic crust and mantleJournal of Geophysical Research, Vol. 108, B5, 10.1029/2002JB001951CanadaGeophysics - seismics, Anisotrophy
DS2003-0069
2003
Bostock, M.G.Bank, C.G., Bostock, M.G.Linearized inverse scattering of teleseismic waves for anisotropic crust and mantleJournal of Geophysical Research, Vol. 108, 5, ETG3 DOI 10.1029/2002JB001951Northwest TerritoriesGeophysics - seismics
DS2003-0138
2003
Bostock, M.G.Bostock, M.G.Linearized inverse scattering of teleseismic waves for anisotropic crust and mantleJournal of Geophysical Research, Vol. 108, B5, 10.1029/2002JB001950CanadaGeophysics - seismics, Anisotrophy
DS2003-0139
2003
Bostock, M.G.Bostock, M.G.Linearized inverse scattering of teleseismic waves for anisotropic crust and mantleJournal of Geophysical Research, Vol. 108, 5, ETG3 DOI 10.1029/2002JB001950Northwest TerritoriesGeophysics - seismics
DS2003-1302
2003
Bostock, M.G.Snyder, D.B., Bostock, M.G., Lockhart, G.D.Mapping the mantle lithosphere for diamond potential8 Ikc Www.venuewest.com/8ikc/program.htm, Session 9, AbstractMantleCraton studies - geophysics seismics, earthquakes, Review
DS2003-1303
2003
Bostock, M.G.Snyder, D.B., Bostock, M.G., Lockhart, G.D.Two anisotropic layers in the Slave CratonLithos, Vol. 71, 2-4, pp. 529-539.Northwest Territories, NunavutGeophysics - seismics
DS200412-0092
2003
Bostock, M.G.Bank, C.G., Bostock, M.G.Linearized inverse scattering of teleseismic waves for anisotropic crust and mantle structure: 2. numerical examples and applicaJournal of Geophysical Research, Vol. 108, 5, ETG3 DOI 10.1029/2002 JB001951Canada, Northwest TerritoriesGeophysics - seismics
DS200412-0186
2003
Bostock, M.G.Bostock, M.G.Linearized inverse scattering of teleseismic waves for anisotropic crust and mantle structure: 1. Theory.Journal of Geophysical Research, Vol. 108, 5, ETG3 DOI 10.1029/2002 JB001950Canada, Northwest TerritoriesGeophysics - seismics
DS200412-1865
2003
Bostock, M.G.Snyder, D.B., Bostock, M.G., Lockhart, G.D.Mapping the mantle lithosphere for diamond potential.8 IKC Program, Session 9, AbstractMantleCraton studies - geophysics seismics, earthquakes Review
DS200412-1866
2003
Bostock, M.G.Snyder, D.B., Bostock, M.G., Lockhart, G.D.Two anisotropic layers in the Slave Craton.Lithos, Vol. 71, 2-4, pp. 529-539.Canada, NunavutGeophysics - seismics
DS200412-1868
2004
Bostock, M.G.Snyder, D.B., Rondenay, S., Bostock, M.G., Lockhart, G.D.Mapping the mantle lithosphere for diamond potential using teleseismic methods.Lithos, Vol. 77, 1-4, Sept. pp. 859-872.Canada, Northwest TerritoriesSlave Craton, exploration geophysics - seismics, imagin
DS200712-0909
2006
Bostock, M.G.Rondenay, S., Snyder, D.B., Chen, C.W., Straub, K.M., Bank, C.G., Bostock, M.G.Insight into the assembly and evolution of the Slave Craton from teleseismic dat a analyses.Geochimica et Cosmochimica Acta, In press availableCanada, Northwest TerritoriesGeophysics - seismics
DS200812-0740
2008
Bostock, M.G.Mercier, J-P., Bostock, M.G., Audet, P., Gaherty, J.B., Garnero, E.J., Revenaugh, J.The teleseismic signature of fossil subduction: northwestern Canada. (part of Lithoprobe)Journal of Geophysical Research, Vol. 113, B 04308Canada, Northwest TerritoriesGeophysics - seismics
DS200912-0495
2009
Bostock, M.G.Mercier, J.P., Bostock, M.G., Cassidy, J.F., Dueker, K., Gaherty, J.B., Garnero, E.J., Revenaugh, ZandtBody wave tomography of western Canada.Tectonophysics, Vol. 475, 2, pp. 480-492.Canada, Alberta, British Columbia, Northwest TerritoriesGeophysics - seismics
DS201012-0066
2010
Bostock, M.G.Bostock, M.G., Eaton, D.W., Snyder, D.B.Teleseismic studies of the Canadian landmass: lithoprobe and its legacy.Canadian Journal of Earth Sciences, Vol. 47, 4, pp. 445-461.CanadaGeophysics - seismic
DS201012-0128
2010
Bostock, M.G.Courtier, A.M., Gaherty, J.B., Revenaugh, J., Bostock, M.G., Gamero, E.J.Seismic anisotropy associated with continental lithosphere accretion beneath the CANOE array, northwestern Canada.Geology, Vol. 38, 10, pp. 887-890.Canada, Alberta, Northwest TerritoriesGeophysics - seismics
DS201012-0668
2010
Bostock, M.G.Schaeffer, A., Bostock, M.G.A low velocity zone atop the transition zone in northwestern Canada.Journal of Geophysical Research, Vol. 115, no. B6, B06302.Canada, Northwest TerritoriesGeophysics - seismics
DS1981-0093
1981
Bostrom, R.C.Bostrom, R.C.Disruption of Gondwanaland, Reorganization of the Convection in the Mantle.Geocongress '81 Open Session., ABSTRACT VOLUME, PP. 5-8.South AfricaTectonics
DS200612-0151
2006
Bostrom, R.C.Bostrom, R.C.Global tectonics under 'g' having a minute westward tilt.Terra Nova, Vol. 18, 1p. Feb. pp. 55-62.GlobalTectonics
DS1990-0225
1990
Bostwick, C.J.Bostwick, C.J., Pelley, C.W.Computer aided interpretation of geotechnical dataThe Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Annual Meeting Paper preprint, No. 100, 19pGlobalComputer, Numerical modeling
DS1993-0141
1993
Boswell, R.J.Boswell, R.J.Mineralogy and geochemistry of tropical rain forest soils, Ashanti, SOURCE[ Chemical GeologyChemical Geology, Vol. 106, pp. 345-358GhanaGeochemistry, Weathering
DS1986-0091
1986
Bosworth, W.Bosworth, W.Off axis volcanism in the Gregory rift, East Africa and modelsfor continental riftingGeological Society of America (GSA) Abstract Volume, Vol. 18, No. 6, p. 547. (abstract.)Kenya, East AfricaTectonics
DS1986-0092
1986
Bosworth, W.Bosworth, W.A new look at Gregory's rift: the structural style ofcontinentalriftingEos, Vol. 67, No. 29, July 22, p. 577, pp. 582-583Kenya, East Africatectonics
DS1989-0149
1989
Bosworth, W.Bosworth, W.Basin and range style tectonics in East AfricaJournal of African Earth Sciences, Vol. 8, No. 2/3/4, pp. 191-202East AfricaTectonics, Rifting -Basin and Range
DS1989-0727
1989
Bosworth, W.Jorgensen, G.J., Bosworth, W.Gravity modeling in the Central African Rift System,Sudan: rift geometries and tectonic significanceJournal of African Earth Sciences, Vol. 8, No. 2/3/4, pp. 283-306GlobalTectonics, Rifting -Sudan
DS1991-1666
1991
Bosworth, W.Strecker, M.R., Blisniuk, P., Bosworth, W.The kinematic evolution of the central Kenya rift in the light of the East African stress field historyGeological Society of America Annual Meeting Abstract Volume, Vol. 23, No. 5, San Diego, p. A 134KenyaTectonics, Rifting
DS1992-0147
1992
Bosworth, W.Bosworth, W.Mesozoic and Early Tertiary rift tectonics in East AfricaTectonophysics, Vol. 209, pp. 115-137East Africa, KenyaTectonics, Rifting
DS1992-1489
1992
Bosworth, W.Strecker, M., Bosworth, W.Quaternary stress field change in Gregory Rift, KenyaEos Transactions, Vol. 72, No. 3, January 15, p. 17, 21, 22KenyaTectonics, Rifting -Gregory Rift
DS1997-0454
1997
Bosworth, W.Guiard, R., Bosworth, W.Senonian basin inversion and rejuvenation of rifting in Africa and Arabia:synthesis and implications to plateTectonophysics, Vol. 282, No. 1-4, Dec. 15, pp. 39-82.Africa, ArabiaBasin, Tectonics
DS1997-0455
1997
Bosworth, W.Guiraud, R., Bosworth, W.Senonian basin inversion and rejuvenation of rifting in Africa and Arabia:synthesis and implications -Tectonophysics, Vol. 282, No. 1-4, Dec. 15, pp. 1-38.AfricaTectonics - plate scale, Rifting
DS2000-0367
2000
Bosworth, W.Guiraud, R., Bosworth, W.Phanerozoic geodynamic evolution of northeastern Africa and the northwestern Arabian PlatformTectonophysics, Vol. 315, No. 1-4, Dec. 31, pp. 73-108.Africa, ArabiaGeodynamics, Craton
DS1989-0150
1989
Botbol, J.M.Botbol, J.M.Multivariate clustering based on entropyUnited States Geological Survey (USGS) Bulletin, No. 1893, 32pGlobalGeochemistry, Computer -entropy
DS201312-0200
2013
Botcharnikov, R.E.De Moor, M., Fischer, T.P., King, P.L., Botcharnikov, R.E., Hervig, R.L., Hilton, D.R., Barry, P.H., Mangasini, F., Ramirez, C.Volatile rich silicate melts from Oldoinyo Lengai volcano (Tanzania): implications for carbonatite genesis and eruptive behavior.Earth and Planetary Science Letters, Vol. 361, pp. 379-390.Africa, TanzaniaDeposit - Oldoinyo Lengai
DS201709-2034
2017
Botcharnikov, R.E.Mollex, G., France, L., Furi, E., Bonnet, R., Botcharnikov, R.E., Zimmermann, L., Wilke, S., Deloule, E., Chazot, G., Kazimoto. E.O., Marty, B., Burnard, P.The Oldoinyo Lengai volcano plumbing system architecture, and composition from source to surface.Goldschmidt Conference, abstract 1p.Africa, Tanzaniadeposit, Oldoinyo

Abstract: Cognate xenoliths that have been emitted during the last sub-plinian eruption in 2007-08 at Oldoinyo Lengai (OL) represent a unique opportunity to document the igneous processes occuring within the active magma chamber. Detailed petrographic descriptions coupled to a thermobarometric approach, and to the determination of volatile solubility models, allow us to identify the melt evolution at magma chamber conditions, and the storage parameters (P, T). Results indicate that a fresh phonolite melt (~1060°C) was injected into a crustal magma chamber at 11.5 ±3.5 km depth, in agreement with geophysical surveys performed during the eruption. The phonolite contains high volatile contents: 3.2 wt.% H2O and 1.4 wt.% CO2. The liquid line of descent highlights an evolution to nephelinite compositions by cooling down to 880°C. Our results support previous results related to this eruption, and are similar to the historical products emitted during the whole volcano history, allowing us to suggest that no major modification in the plumbing system has occured during the OL evolution. New noble gas results show that: i. fumaroles display constant He isotopic signature since 1988; ii. Cognate xenoliths documenting the active magma chamber and fumaroles display similar He isotopic values (6.58±0.46RA, and 7.31±0.40RA, respectively); iii. OL He isotopic composition is similar to that of other silicate volcanoes of the Arusha region, and comparable to the typical subcontinental lithospheric mantle (SCLM) range (5.2 to 7.0 RA); iv. Ne isotopic ratio of OL is following the MORB signature. Those results are interpreted as showing that 1/ no major modification in the hydrothermal system architecture has occured since 1988 despite major modification of the summit crater morphology, 2/ no contamination by either the atmospheric gases, or crustal material assimilation has occured between the magma chamber and the surface, and 3/ the source of OL and of the other silicate volcanoes in the Arusha region is a SCLM metasomatized by asthenospheric fluids.
DS201812-2779
2018
Botcharnikov, R.E.Benard, A., Klimm, K., Woodland, A.B., Arculus, R.J., Wilke, M., Botcharnikov, R.E., Shimizu, N., Nebel, O., Rivard, C., Ionov, D.A.Oxidising agents in sub-arc mantle melts link slab devolatillisation and arc magmas.Nature Communications, Vol. 9, 1, doi: 10.1038/s41467-018-05804-2 11p.Mantlemelting

Abstract: Subduction zone magmas are more oxidised on eruption than those at mid-ocean ridges. This is attributed either to oxidising components, derived from subducted lithosphere (slab) and added to the mantle wedge, or to oxidation processes occurring during magma ascent via differentiation. Here we provide direct evidence for contributions of oxidising slab agents to melts trapped in the sub-arc mantle. Measurements of sulfur (S) valence state in sub-arc mantle peridotites identify sulfate, both as crystalline anhydrite (CaSO4) and dissolved SO42? in spinel-hosted glass (formerly melt) inclusions. Copper-rich sulfide precipitates in the inclusions and increased Fe3+/?Fe in spinel record a S6+Fe2+ redox coupling during melt percolation through the sub-arc mantle. Sulfate-rich glass inclusions exhibit high U/Th, Pb/Ce, Sr/Nd and ?34S (+?7 to +?11‰), indicating the involvement of dehydration products of serpentinised slab rocks in their parental melt sources. These observations provide a link between liberated slab components and oxidised arc magmas.
DS202008-1411
2020
Botcharnikov, R.E.Korneeva, A.A., Nikolai, N.A., Kamenetsky, V.S., Portnyagin, M.V., Savelyev, D.P., Krasheninnikov, S.P., Abersteiner, A., Kamenetsky, M.B., Zelenski, M.E., Shcherbakov, V.D., Botcharnikov, R.E.Composition, crystallization conditions and genesis of sulfide saturated parental melts of olivine-phyric rocks from Kamchatsky Mys ( Kamchatka, Russia).Lithos, 10.1016/j.lithos.2020.105657Russia, Kamchatkapicrites

Abstract: Sulfide liquids that immiscibly separate from silicate melts in different magmatic processes accumulate chalcophile metals and may represent important sources of the metals in Earth's crust for the formation of ore deposits. Sulfide phases commonly found in some primitive mid-ocean ridge basalts (MORB) may support the occurrence of sulfide immiscibility in the crust without requiring magma contamination and/or extensive fractionation. However, the records of incipient sulfide melts in equilibrium with primitive high-Mg olivine and Cr-spinel are scarce. Sulfide globules in olivine phenocrysts in picritic rocks of MORB-affinity at Kamchatsky Mys (Eastern Kamchatka, Russia) represent a well-documented example of natural immiscibility in primitive oceanic magmas. Our study examines the conditions of silicate-sulfide immiscibility in these magmas by reporting high precision data on the compositions of Cr-spinel and silicate melt inclusions, hosted in Mg-rich olivine (86.9-90 mol% Fo), which also contain globules of magmatic sulfide melt. Major and trace element contents of reconstructed parental silicate melts, redox conditions (?QFM = +0.1 ± 0.16 (1?) log. units) and crystallization temperature (1200-1285 °C), as well as mantle potential temperatures (~1350 °C), correspond to typical MORB values. We show that nearly 50% of sulfur could be captured in daughter sulfide globules even in reheated melt inclusions, which could lead to a significant underestimation of sulfur content in reconstructed silicate melts. The saturation of these melts in sulfur appears to be unrelated to the effects of melt crystallization and crustal assimilation, so we discuss the reasons for the S variations in reconstructed melts and the influence of pressure and other parameters on the SCSS (Sulfur Content at Sulfide Saturation).
DS1991-0338
1991
Botelho, N.F.Danni, J.C.M., Botelho, N.F., Grossi Sad, J.H.Bulk and mineral chemistry of the olivine leucitite from Juana Vaz, Sacramento, Minas Gerais, BrasilProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 60-62BrazilRock chemistry, Leucitite -analyses
DS201712-2725
2017
Botelho, N.F.Rossoni, M.B., Bastos Neto, A.C., Souza, V.S., Marquea, J.C., Dantas, E., Botelho, N.F., Giovannini, A.L., Pereira, V.P.U-Pb zircon geochronological investigation on the Morro dos Seis Lagos carbonatite complex and associated Nb deposit ( Amazonas, Brazil).Journal of South American Earth Sciences, Vol. 80, pp. 1-17.South America, Brazilcarbonatite

Abstract: We present results of U-Pb dating (by MC-ICP-MS) of zircons from samples that cover all of the known lithotypes in the Seis Lagos Carbonatite Complex and associated lateritic mineralization (the Morro dos Seis Lagos Nb deposit). The host rock (gneiss) yielded an age of 1828 ± 09 Ma interpreted as the crystallization time of this unit. The altered feldspar vein in the same gneiss yielded an age of 1839 ± 29 Ma. Carbonatite samples provided 3 groups of ages. The first group comprises inherited zircons with ages compatible with the gneissic host rock: 1819 ± 10 Ma (superior intercept), 1826 ± 5 Ma (concordant age), and 1812 ± 27 Ma (superior intercept), all from the Orosirian. The second and the third group of ages are from the same carbonatite sample: the superior intercept age of 1525 ± 21 Ma (MSWD ¼ 0.77) and the superior intercept age of 1328 ± 58 Ma (MSWD ¼ 1.4). The mineralogical study indicates that the ~1.3 Ga zircons have affinity with carbonatite. It is, however, a tendence rather than a well-defined result. The data allow state that the age of 1328 ± 58 Ma represents the maximum age of the carbonatite. Without the same certainty, we consider that the data suggest that this age may be the carbonatite age, whose emplacement would have been related to the evolution of the K'Mudku belt. The best age obtained in laterite samples (a superior intercept age of 1828 ± 12 Ma) is considered the age of the main source for the inherited zircons related to the gneissic host rock.
DS201901-0079
2018
Botes, Z.A.Smith, A.M., Guastella,L.A., Botes, Z.A.Submarine mass flow channels as an underlying control for headland-bound embayments southeastern African coastline.South African Journal of Geology, Vol. 121, pp. 227-236.Africa, South Africageomorphology

Abstract: Rocky reaches of the southeast African coastline are characterized mainly by log-spiral and headland-bound bays. Extensive fieldwork was carried out to investigate both documented and new exposures of Cretaceous beds on the southern KwaZulu-Natal and upper Eastern Cape (Transkei) coasts. Our results suggest that geological inheritance plays an important role in the contemporary rocky coast geomorphology. We offer evidence that post-Gondwana break-up mass flow channels play an important role in the present southeast African coastline morphology. Mass flow channels contain fills of incompetent Cretaceous rocks which are being preferentially eroded by prevailing marine and fluvial processes to form headland-bound embayment landforms. This study has identified an important geomorphic process for the development of the current southeast African coastline.
DS1991-0625
1991
Both, R.Gulson, B.L., Solomon, M., Vaasjoki, M., Both, R.Tasmania adrift?Australian Journal of Earth Sciences, Vol. 38, pp. 249-250TasmaniaTectonics, Structure
DS1995-0177
1995
Botha, G.A.Botha, G.A., Fedoroff, N.Paleosols in Late Quaternary colluvium, northern KwaZulu-Natal, SouthAfrica.Journal of African Earth Sciences, Vol. 21, No. 3, August pp. 291-312.South AfricaGeomorphology, Paleosols
DS201609-1705
2010
Botha, J.Botha, J., Nichol, S., Swarts, B.Rapid underground development optimization at Culli nan diamond mine using computer simulation.The 4th Colloquium on Diamonds - source to use held Gabarone March 1-3, 2010, 14p.Africa, South AfricaDeposit - Cullinan

Abstract: There are many underground mining software tools available to plan and schedule the development of underground mines. A shortfall of these tools is the optimization of the underground equipment and strategy in order to maximize the development rate. This paper will illustrate how the SimMine® software was used to maximize underground development at Petra Diamonds' Cullinan Diamond Mine. It will also determine the effect of various development strategies and equipment capacities on the underground development rate and pinpoint potential bottlenecks in the mine development cycle. Full Article Download:
DS200612-0672
2006
Botha, M.Keenan, C., Botha, M., Ward, R.Quantifiable cut grade system within an educational setting.GIA Gemological Research Conference abstract volume, Held August 26-27, p. 34-35. 1/2p.TechnologyDiamond cutting and polishing industry
DS200712-0096
2006
Botha, M.Botha, M.Three dimensional solid modeling in applied diamond crystallography.Gems & Gemology, 4th International Symposium abstracts, Fall 2006, p.129. abstract onlyTechnologyDiamond crystallography
DS1981-0094
1981
Botha, M.I.Botha, M.I.100 the Koffiefontein CentenaryIndiaqua., No. 30, 1981-3, PP. 23-27.South AfricaHistory
DS1993-1491
1993
Botha, W.J.Smith, R.M.H., Eriksson, P.G., Botha, W.J.A review of the stratigraphy and sedimentary environments of the Karoo age basins of southern AfricaJournal of African Earth Sciences, Vol. 16, No. 1-2, January-February pp. 143-170South AfricaBasins, Stratigraphy
DS1960-0925
1968
Bothner, W.A.Bothner, W.A.Preliminary gravity study of the Precambrian Sherman granite, Albany and Laramie Counties, Wyoming.Geological Society of America (GSA) Bulletin., pp. 172-76.WyomingGeophysics - Gravity
DS1993-0142
1993
Boting, G.Boting, G., Russel, M.Elizabeth Bay mine: reappraisal and commission of mining operationsConference on Mining Investment in Namibia, March 17-19th., 1993, Abstracts pp. 83-88NamibiaMining, Deposit -Elizabeth Bay
DS1992-1377
1992
Botiva, M.M.Shaskin, V.M., Stolyarenko, V.V., Botiva, M.M.Platinum metal mineralization of the Koksharovka alkalic ultramaficplutonDoklady Academy of Sciences, USSR, Earth Science Section, Vol. 316, No. 1-6, pp. 184-188Russia, Commonwealth of Independent States (CIS)Alkaline rocks, platinum group elements (PGE), Layered intrusion
DS1970-0030
1970
Botkunoov, A.T.Botkunoov, A.T.Distribution of Spinel Twins in a Diamond from the Mir Kimberlite Pipe.Zap. Vses. Miner. Obshch., PT. 99, No. 5, PP. 601-603.RussiaBlank
DS1960-0638
1966
Botkunov, A.I.Botkunov, A.I., Garanin, V.K., Kudryavtseva, G.P., Kharlamov, Ye.S.First find of syngenetic dolomite inclusions in zircon from the Mirkimberlite pipeDoklady Academy of Science USSR, Earth Science Section, Vol. 278, No. 1-6, pp. 161-164RussiaPetrology, Zircon
DS1980-0038
1980
Botkunov, A.I.Argunov, K.P., Botkunov, A.I., et al.Small Diamonds of Cubic Habit from Kimberlites of YakutiaTsnigri, No. 153, PP. 75-79.RussiaBlank
DS1981-0095
1981
Botkunov, A.I.Botkunov, A.I., Garanin, V.K., et al.Sulfide Inclusions in Olivine from the Udachnaya Kimberlitepipe.Doklady Academy of Science USSR, Earth Science Section., Vol. 247, No. 1-6, PP. 113-117.RussiaPetrography
DS1982-0007
1982
Botkunov, A.I.Alexeevski, K.M., Botkunov, A.I., et al.Kelphite of Pyrope in SandstonesDoklady Academy of Sciences AKAD. NAUK SSSR., Vol. 265, No. 6, PP. 1475-1477.RussiaBlank
DS1983-0140
1983
Botkunov, A.I.Botkunov, A.I., Garinin, V.K., Kudryavtseva, G.P.Mineral Inclusions in Garnets of Yakutia Kimberlites.(russian)Zap. Vses Mineral. Obshch., (Russian), Vol. 112, No. 3, pp. 311-324RussiaInclusions
DS1984-0165
1984
Botkunov, A.I.Botkunov, A.I., Garanin, V.K., et al.Ist Occurrence of Syngenetic Inclusions of Dolomite in Zirconium from the Kimberlite Pipe, Mir.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 278, No. 5, PP. 1214-1217.RussiaGenesis
DS1985-0005
1985
Botkunov, A.I.Alexseevskii, K.M., Botkunov, A.I., Nikolaeva, T.T., Ermilov.Chemical Changes of the Environment of Diamond Genesis.(russian)Vopr. Orudeneniya Ul'tramfitakh, Nauka Moscow, (Russian), pp. 105-117RussiaBlank
DS1985-0075
1985
Botkunov, A.I.Botkunov, A.I., Garanin, V.K., Krot, A.N., et al.Primary Hydrocarbon Inclusions in Garnets from the Mir and Sputnik Kimberlite Pipes.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 280, No. 2, PP. 468-472.RussiaBlank
DS1986-0093
1986
Botkunov, A.I.Botkunov, A.I., Garanin, V.K., Ivanova, T.N., Krot, A.N., KudryavtsevaOptical and colorimetric spectroscopic characteristics of garnets withNov. Dann. O Minetal. Moskva, (Russian), No. 33, pp. 120-129RussiaMineralogy, Garnet
DS1986-0094
1986
Botkunov, A.I.Botkunov, A.I., Garanin, V.K., Krot, A.N., Kudryavtseva, G.P., MatsyukPrimary hydrocarbon inclusions in garnets from the Mir and Sputnikkimberlite pipesDoklady Academy of Science USSR, Earth Science Section, Vol. 280, No. 1-6, October pp. 136-141RussiaMineralogy, Garnet
DS1986-0095
1986
Botkunov, A.I.Botkunov, A.I., Garanin, V.K., Kudryavtseva, G.P., Kharlamov, Ye.S.First find of syngenetic dolomitic inclusions in zircon from the Mirkimberlite pipeDoklady Academy of Science USSR, Earth Science Section, Vol. 278, No. 1-6, April, pp. 161-164RussiaMineralogy
DS1987-0068
1987
Botkunov, A.I.Botkunov, A.I., Garanin, V.K., Krot, A.N., Kudryavtseva, G.P.Garnet mineral inclusions in kimberlites of Yakutia,their genetic and practical importance.(Russian)Geol. Rudyn. Mestoroz., (Russian), Vol. 29, No. 1, pp. 15-29Russia, Anabar shieldMineral inclusions, Petrology
DS1987-0069
1987
Botkunov, A.I.Botkunov, A.I., Garanin, V.K., Krot, A.N., Kuryavtseva, G.P.Mineral inclusions in garnets from Yakutian kimberlites and their genetic and practical significance.*rusGeol. Rudn. Mestorozhd. *rus, Vol. 20, No. 1, pp. 15-29RussiaMineralogy
DS1987-0070
1987
Botkunov, A.I.Botkunov, A.I., Matsyuk, S.S., PLatonov, A.N.Distribution of paragenetic types of garnets in kimberlite rocks from a horizon of the Mir pipe; from optical spectra and colorimetry data.(Russian)Geol. Zhurnal, (Russian), Vol. 47, No. 1, pp. 124-132RussiaBlank
DS1987-0581
1987
Botkunov, A.I.Platanov, A.N., Botkunov, A.I., Matsyuk, S.S.Distribution of paragenetic types of garnets in kimberlitic rocks from a horizon of the Mir pipe (based on optical spectroscopic colorimetric data).Geol. Zhurn. (Russian), Vol. 47, No. 1, pp. 124-132RussiaBlank
DS1988-0234
1988
Botkunov, A.I.Galimov, E.M., Botkunov, A.I., Bannikova, L.A., et al.Isotopic composition of carbon from gas and bitumens of gas-liquid inclusions in garnet from the Mir kimberlite pipeDoklady Academy of Science USSR, Earth Science Section, Vol. 301, No. 4, July-Aug. pp. 184-185RussiaGeochronology, Carbon -Mir pipe
DS1989-0460
1989
Botkunov, A.I.Galimov, E.M., Botkunov, A.I., Garanin, V.K.Carbon bearing fluid inclusions in olivine and garnet from the Udachnaya kimberlite pipe.(Russian)Geochemistry International (Geokhimiya), (Russian), No. 7, pp. 1011-1015RussiaDiamond inclusions, Garnet analyses
DS1989-0461
1989
Botkunov, A.I.Galimov, E.M., Botkunov, A.I., Garanin, V.K., Spasennykh, M. Yu.Carbon-containing fluid inclusions in garnet and olivine from Kimberlites of the Udachnaya pipe. (USSR)(Russian)Geochemistry International (Geokhimiya), (Russian), No. 7, pp. 1011-1015RussiaFluid inclusions, Garnet
DS1990-0505
1990
Botkunov, A.I.Galimov, E.M., Botkunov, A.I., Garanin, V.K.Carbon bearing fluid inclusions in olivine and garnet from Udachnaya pipekimberlitesGeochemistry International, Vol. 27, No. 2, February pp. 87-90RussiaGeochronology, Carbon inclusions
DS1993-0859
1993
Botkunov, A.I. et.Krot, A.N., Poskukojovsky, T.V., Guseva, E.V., Galimov, E.M., Botkunov, A.I. et.Genesis of the garnets containing hydrocarbon inclusions (Mir kimberlitepipe). (Russian)Geochemistry International (Geokhimiya), (Russian), No. 6, June pp. 891-899RussiaGeochemistry -garnets, Deposit -Mir
DS1997-1073
1997
Botkunova, A.I.Sobolev, N.V., Kaminsky, F.V., Botkunova, A.I., Griffin, W.L., YefimovaMineral inclusions in diamonds from the Sputnik kimberlite pipe, YakutiaLithos, Vol. 39, No. 3-4, Feb. 1, pp. 135-158.Russia, YakutiaMineral chemistry, Diamond inclusions, mineralogy, Deposit - Sputnik
DS2001-0697
2001
Botlho, N.F.Liverton, T., Botlho, N.F.Fractionated alkaline rare metal granites: two examplesJournal of African Earth Sciences, Vol. 19, No. 3, Apr. pp.399-412.Brazil, YukonAlkaline granites, Parana, Seagull-thirtymile
DS1995-2116
1995
Botova, M.Zakharchnko, O., Botova, M., Khachatryan, G.Diamonds from Lomonosov mine of Arkangelsk regionProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 680.Russia, ArkangelskDiamond morphology, Deposit -Lomonosov
DS1986-0684
1986
Botova, M.MRoznova, Ye.V., Frantsesson, Ye.V., Botova, M.M, Panteleyev, V.V.Native iron and complex iron, titanium and manganese oxidesinkimberliteDoklady Academy of Science USSR, Earth Science Section, Vol. 278, No. 1-6, April, pp. 146-150RussiaX-ray spectrometry
DS1975-0857
1978
Botova, M.M.Rozova, YE.V., Pleshakov, A.P., Botova, M.M.New Dat a on Chemical Composition and Physical Properties Of ulvospinel from Ilmenite Nodules in Kimberlite.Doklady Academy of Science USSR, Earth Science Section., Vol. 240, No. 1-6, PP. 184-187.RussiaKimberlite
DS1980-0294
1980
Botova, M.M.Rozova, YE.V., Frantsesson, YE.V., Pleshakov, A.P., Botova, M.M.The First Occurrence of Crichtonite and Ilmenite-hematite In Kimberlites from Yakutia and Their Genesis.Tsnigri, No. 50, PP. 75-81.RussiaBlank
DS1984-0620
1984
Botova, M.M.Rozova, E.V., Frantsesson, E.V., Botova, M.M.Native Iron and Complex Iron, Titanium, and Manganese Oxides in Kimberlites.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 278, No. 2, PP. 456-461.RussiaBlank
DS1985-0199
1985
Botova, M.M.Frantsesson, E.V., Roxova, E.V., Botova, M.M., Pleshakov, A.P.Zoning of Chrome Spinellids from Yakutian KimberlitesDoklady Academy of Sciences AKAD. NAUK SSSR., Vol. 280, No. 3, PP. 742-745.RussiaMineralogy
DS1985-0200
1985
Botova, M.M.Frantsesson, Y.V., Rozova, Y.V., Botova, M.M., Pleshakov, A.P.Zoning in Chrome Spinels in Kimberlites from Yakutia.(russian)Doklady Academy of Sciences Akademy Nauk SSSR (Russian), Vol. 280, No. 3, pp. 742-745RussiaMineralogy, Kimberlite
DS1991-1918
1991
Botova, M.M.Zakarchenko, O.D., Kharkiv, A.D., Botova, M.M., Makhin, A.I.Inclusions of deep seated minerals in diamonds from kimberlite rocks From the northern Russian Platform*(in Russian)Mineral. Zhurn., (Russian), Vol. 13, No. 5, pp. 42-52RussiaPetrology, Diamond inclusions
DS1991-1920
1991
Botova, M.M.Zarharchenko, O.D., Kharkiv, A.D., Botova, M.M., Makhin, A.I.Inclusions of plutonic minerals in diamonds from kimberlite rocks of the northern east European PlatformProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 579-580RussiaDiamond inclusions, Olivine, coesite, chrome-spinellid
DS201012-0067
2010
Botswana Business NewsBotswana Business NewsDebswana commences works on Jwaneng Cut 8 project.Botswana Business News, Jan. 24, 1p.Africa, BotswanaNews item - Debswana
DS201605-0815
2016
Botswana Geological PortalBotswana Geological PortalPartnership of Botswana Geoscience Institute and Geosoft. Dat a includes airborne and ground geophysics, geochemistry.http://geoscienceportal.geosoft.com/ Botswana/search, Apr. 12, 1p.Africa, BotswanaDatabase

Abstract: Geosoft is pleased to announce the launch of the Botswana Geoscience Portal, a partnership initiative with the Botswana Geoscience Institute and industry sponsors. Developed and hosted by Geosoft, the portal provides free access to multi-disciplinary datasets from Ngamiland, a district in the country's northwest. It is available online at: http://geoscienceportal.geosoft.com/Botswana/search. The geoscience portal aims to help Botswana attract new investment in resource exploration, improve transparency and stimulate collaboration between government, industry and the public to advance understanding of the economic and social needs of the North-West district. Tiyapo Hudson Ngwisanyi, Chief Executive Officer of the Botswana Geoscience Institute said: “Making geoscientific data more accessible and transparent is critical to furthering understanding of the North-West district, and encouraging new investment in resource exploration within Africa. The portal is a welcome development that will assist us in promoting ongoing, productive collaboration between government and industry.” “Geosoft is excited to be part of an initiative that demonstrates how government and industry can work together to encourage mineral exploration investment and thus downstream economic growth in the country,” said Tim Dobush, Chief Executive Officer of Geosoft. “We are continually engaging with government organizations like the Botswana Geoscience Institute and industry leaders to innovate, and maximize the value of geoscience data for resource discovery and to meet the social/economic needs of the broader public sector.” Data available on the Botswana Geoscience Portal includes airborne geophysics, ground geophysics and geochemistry. Future updates will provide access to borehole data, remote sensing, seismic surveys and information products including interpretations and 3D models.- See more at: http://www.geosoft.com/news/botswana-geoscience-portal-goes-live#sthash.CZGrHC4h.dpuf
DS1991-0153
1991
Botswana geological surveyBotswana geological surveyAnnual report for the year 1990.. brief mention of diamond explorationactivitiesBotswana Geological Survey Dept, Annual Report for 1990, p. 7, 8, 9, 22BotswanaNews item, Diamond exploration activities -very brief
DS200612-0152
2006
Botswana Geological SurveyBotswana Geological SurveyThe Pre-Kalahari geological map of BotswanaBotswana Geological Survey, 1: 1 million BWP 70.Africa, BotswanaMap - geology
DS200612-0153
2006
Botswana Geological SurveyBotswana Geological SurveyKimberlites and kimberlite indicator location map 2006. This first edition map shows locations recovered from prospecting activities.Botswana Geological Survey, Africa, BotswanaMap - prospects
DS2001-0126
2001
Botswana GovernmentBotswana GovernmentStatement by the government - regarding diamonds.... Diamonds in Botswana are development diamonds.Botswana government., May 16, 1p.BotswanaNews item - press release
DS2001-0127
2001
Botswana GovernmentBotswana GovernmentBotswana's 'prosperity diamonds' support Nation's healthcare, schools and economy.Botswana government., Feb. 14, 1p.BotswanaNews item, Prosperity diamonds
DS201612-2298
2016
Botsyun, S.Ernst, R.E., Buchan, K.L., Botsyun, S.Map of mafic dyke swarms and related units of Russia and adjacent regions.Acta Geologica Sinica, Vol. 90, July abstract p. 22-23.Russia, SiberiaDykes
DS201909-2103
2019
Botsyun, S.Veselovskiy, R.V., Thomson, S.N., Arzamastsev, A.A., Botsyun, S., Travin, A.V., Yudin, D.S., Samsonov, A.V., Stepanova, A.V.Thermochronology and exhumation history of the northeastern Fennoscandian shield since 1.9 Ga: evidence from 40Ar/39/Ar and apatite fission track data from the Kola Peninsula.Tectonics, Vol. 38, 7, pp. 2317-2337.Europe, Fennoscandia, Kola Peninsulageochronology

Abstract: Results from thermochronological studies have multiple applications to various problems in tectonics and landform evolution. However, up to now a lack of thermochronological data from the northeastern Fennoscandian Shield has complicated the interpretation of tectonothermal evolution of the region. Here, we use both new and previously published multimineral 40Ar/39Ar data (amphibole, mica, and feldspar) on the various Precambrian magmatic and metamorphic complexes to reconstruct the thermal history of NE Fennoscandia within the Kola Peninsula area in the interval 1900-360 Ma. Using the apatite fission track method as well as a numerical model of the heating?cooling process of northeastern Fennoscandia's upper crust, we have reconstructed its thermal evolution for the interval 360-0 Ma. According to our model, since Lapland?Kola orogenesis (1930-1905 Ma) northeastern Fennoscandia experienced a quasi?monotonous cooling with the average rate of ~0.15 °C/Myr, which is equal to an exhumation rate of ~1-2 m/Myr. New apatite fission track data and time?temperature modeling reveal a “hidden” endogenous thermal event in the NE Fennoscandia that took place between 360 and 300 Ma. This we attribute to an elevated geothermal gradient due to Baltica's drift over the African large low shear?wave velocity province in the lowest mantle and/or thermal blanketing by insulating Devonian?Carboniferous sedimentary/volcanic cover. Our model is further supported by evidence of Late Devonian?Carboniferous rifting in the East and South?Western Barents Basin, as well as various 360-300 Ma magmatic events within SW Fennoscandia and the Baltic countries.
DS201908-1820
2019
Botsyun, S.B.Veselovskiy, R.V., Thomson, S.N., Arzamastsev, A.A., Botsyun, S.B., Travin, A.V., Yudin, D.S., Samsonov, A.V., Stepanova, A.V.Thermochronology and exhumation history of the northeastern Fennoscandian Shield since 1.9 Ga: evidence from 40AR/39Ar and apatite fission track data from the Kola Peninsula.Tectonics, doi.org/10.1029 /2018TC005250Europe, Kola Peninsulageochronology

Abstract: Results from thermochronological studies have multiple applications to various problems in tectonics and landform evolution However, up to now a lack of thermochronological data from the northeastern Fennoscandian Shield has complicated the interpretation of tectonothermal evolution of the region Here, we use both new and previously published multimineral 40Ar/39Ar data (amphibole, mica, and feldspar) on the various Precambrian magmatic and metamorphic complexes to reconstruct the thermal history of NE Fennoscandia within the Kola Peninsula area in the interval 1900–360 Ma Using the apatite fission track method as well as a numerical model of the heating?cooling process of northeastern Fennoscandia's upper crust, we have reconstructed its thermal evolution for the interval 360–0 Ma According to our model, since Lapland?Kola orogenesis (1930–1905 Ma) northeastern Fennoscandia experienced a quasi?monotonous cooling with the average rate of ~0 15 °C/Myr, which is equal to an exhumation rate of ~1–2 m/Myr New apatite fission track data and time?temperature modeling reveal a “hidden” endogenous thermal event in the NE Fennoscandia that took place between 360 and 300 Ma This we attribute to an elevated geothermal gradient due to Baltica's drift over the African large low shear?wave velocity province in the lowest mantle and/or thermal blanketing by insulating Devonian?Carboniferous sedimentary/volcanic cover Our model is further supported by evidence of Late Devonian?Carboniferous rifting in the East and South?Western Barents Basin, as well as various 360–300 Ma magmatic events within SW Fennoscandia and the Baltic countries
DS1991-0154
1991
Bott, M.H.P.Bott, M.H.P.Ridge push and associated plate interior stress in normal and hot spotregionsTectonophysics, Vol. 200, pp. 17-32GlobalHot spots, Tectonics
DS1991-0155
1991
Bott, M.H.P.Bott, M.H.P.Sublithospheric loading and plate boundary forcesPhil. Transactions Royal Society of London, Vol. 337, No. 1645, October 15, pp. 83-94GlobalMantle, Plate tectonics
DS1992-0148
1992
Bott, M.H.P.Bott, M.H.P.The stress regime associated with continental break-upGeological Society Special Publication Magmatism and the causes of the continental, No. 68, pp. 125-136GlobalTectonics, Rifting, structure
DS1993-0143
1993
Bott, M.H.P.Bott, M.H.P.Modelling the plate-driving mechanisMJournal of the Geological Society of London, Vol. 150, No. 5, September pp. 941-952MantleTectonics, Plate moving mechanisms
DS1995-0178
1995
Bott, M.H.P.Bott, M.H.P.Rifted passive marginsContinental Rifts: evolution, structure, tectonics, No. 25, pp. 409-426GlobalGeophysics - seismics, gravity, Structure
DS1995-0179
1995
Bott, M.H.P.Bott, M.H.P.Rifted passive marginsContinental Rifts: evolution, structure, tectonics, No. 25, pp. 409-426.GlobalGeophysics - seismics, gravity, Structure
DS1995-0180
1995
Bott, M.H.P.Bott, M.H.P.Mechanism of rifting: geodynamic modeling of continental rift systemsContinental Rifts: evolution, structure, tectonics, No. 25, pp. 27-46GlobalRifts, Geodynamics
DS1995-0181
1995
Bott, M.H.P.Bott, M.H.P.Mechanism of rifting: geodynamic modeling of continental rift systemsContinental Rifts: evolution, structure, tectonics, No. 25, pp. 27-46.GlobalRifts, Geodynamics
DS1995-0182
1995
Bott, M.H.P.Bott, M.H.P., Hinze, W.J.Methods of investigation: potential field methodsContinental Rifts: evolution, structure, tectonics, No. 25, pp. 93-98North AmericaGeophysics -gravity, magnetics
DS1995-0183
1995
Bott, M.H.P.Bott, M.H.P., Hinze, W.J.Methods of investigation: potential field methodsContinental Rifts: evolution, structure, tectonics, No. 25, pp. 93-98.North AmericaGeophysics -gravity, magnetics
DS1995-0930
1995
Bott, M.H.P.Keller, G.R., Wendlandt, R.F., Bott, M.H.P.West and Central African rift zoneContinental Rifts: evolution, structure, tectonics, No. 25, pp. 437-452West Africa, Central AfricaGeophysics - seismics, gravity, Tectonics, shear zones
DS1995-0931
1995
Bott, M.H.P.Keller, G.R., Wendlandt, R.F., Bott, M.H.P.West and Central African rift zoneContinental Rifts: evolution, structure, tectonics, No. 25, pp. 437-452.West Africa, Central AfricaGeophysics - seismics, gravity, Tectonics, shear zones
DS201112-0904
2010
Bottari, L.Sander, A., Provenzano, C., Valdir Silveira, F., Castro, J.H., Bottari, L.Um novo corpo kimberlitico no escudo sul rio Grandense: petrografia preliminar.5th Brasilian Symposium on Diamond Geology, Nov. 6-12, abstract p. 75.South America, BrazilGeobank
DS1995-2154
1995
BottaziZinngrebe, E., Foley, S.F., Vannucci, R., Bottazi, MatteyMetasomatism of peridotite by alkaline melt and cognate fluid:microchemical and ion probe evidence from low pressureProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 700-702.Russia, Yakutia, Aldan ShieldMetasomatism, Deposit -Inagli complex
DS1999-0634
1999
Bottazi, P.Schmidt, K.H., Bottazi, P., Mengel, K.Trace element partitioning between phlogopite, clinopyroxenes and leucite lamproite melt.Earth and Planetary Science Letters, Vol. 168, No. 3-4, May 15, pp. 287-300.GlobalGeochemistry, Lamproite
DS1991-1397
1991
Bottazzi, P.Rampone, E., Bottazzi, P., Ottolini, L.Complementary Titanium and Zirconium anomalies in orthopyroxene and clinopyroxene from mantle peridotitesNature, Vol. 354, No. 6354, Dec. 19, 26 pp. 518-520MantleClinopyroxenes, titanium, zirconium, Peridotites
DS1992-1015
1992
Bottazzi, P.Mazzucchelli, M., Rivalenti, G., Vannucci, R., Bottazzi, P.Trace element distribution between clinopyroxene and garnet in gabbroicGeochimica et Cosmochimica Acta, Vol. 56, pp. 2371-2385ItalyCrust, Mafic-ultramafic, Garnet, clinopyroxene
DS1993-1650
1993
Bottazzi, P.Vannucci, R., Shimizu, N., Piccado, G.B., Ottolini, L., Bottazzi, P.Distribution of trace elements during breakdown of mantle garnet: an example from Zabargad.Contribution to Mineralogy and Petrology, Vol. 113, pp. 437-449.GlobalMantle, Garnet geochronology
DS1994-1840
1994
Bottazzi, P.Vannucci, R., Bottazzi, P., et al.The trace element variations in clinopyroxenes from spinel peridotite xenoliths from southwest Poland.Mineralogical Magazine, Vol. 58A, pp. 932-933. AbstractAustraliaXenoliths, Geochemistry
DS2001-1022
2001
Bottazzi, P.Scambelluri, M., Bottazzi, P., Trommsdorf, V., VanucciThe analysis of fluid + mineral inclusions in deeply subducted hydrous mantle: implications for genesis...Plinius, No. 24, p. 193-4 abstractMantleTrace element rich supercritical fluids, Subduction
DS2001-1023
2001
Bottazzi, P.Scambelluri, M., Bottazzi, P., Trommsdorff, VannucciIncompatible element rich fluids released by antigorite breakdown in deeply subducted mantle.Earth and Planetary Science Letters, Vol. 192, No. 3, pp. 457-70.MantleGeochemistry, Subduction
DS1998-1290
1998
Bottinga, Y.Schiano, P., Bourdon, B., Bottinga, Y.Low degree partial melting trends recorded in upper mantle mineralsEarth and Planetary Science Letters, Vol. 160, No. 3-4, Aug. 1, pp. 537-550.MantleMelt, Magmatism
DS1999-0404
1999
Bottinga, Y.Lejeune, A.M., Bottinga, Y., Richet, P.Rheology of bubble bearing magmasEarth and Planetary Science Letters, Vol. 166, No. 1-2, Feb. 28, pp. 71-84.GlobalMagmatism
DS1960-1104
1969
Bottino, M.L.Fullagar, P.D., Bottino, M.L.Tertiary Felsic Intrusions in the Valley and Ridge Province, Virginia.Geological Society of America (GSA) Bulletin., Vol. 80, No. 9, PP. 1853-1858.United States, Appalachia, VirginiaGeology
DS201710-2252
2017
Bottke, W.O'Neill, C., Marchi, S., Zhang, S., Bottke, W.Impact driven subduction on the Hadean Earth.Nature Geoscience, Vol. 10, 10, pp. 793-797.Mantlesubduction

Abstract: Impact cratering was a dominant geologic process in the early Solar System that probably played an active role in the crustal evolution of the young terrestrial planets. The Earth’s interior during the Hadean, 4.56 to 4 billion years ago, may have been too hot to sustain plate tectonics. However, whether large impacts could have triggered tectonism on the early Earth remains unclear. Here we conduct global-scale tectonic simulations of the evolution of the Earth through the Hadean eon under variable impact fluxes. Our simulations show that the thermal anomalies produced by large impacts induce mantle upwellings that are capable of driving transient subduction events. Furthermore, we find that moderate-sized impacts can act as subduction triggers by causing localized lithospheric thinning and mantle upwelling, and modulate tectonic activity. In contrast to contemporary subduction, the simulated localized subduction events are relatively short-lived (less than 10?Myr) with relatively thin, weak plates. We suggest that resurgence in subduction activity induced by an increased impact flux between 4.1 and 4.0 billion years ago may explain the coincident increase in palaeointensity of the magnetic field. We further suggest that transient impact-driven subduction reconciles evidence from Hadean zircons for tectonic activity with other lines of evidence consistent with an Earth that was largely tectonically stagnant from the Hadean into the Archaean.
DS202003-0354
2020
Bottke, W.O'Neill, C., March, S., Bottke, W., Fu, R.The role of impacts in Archean tectonics.Geology, Vol. 48, pp. 174-178.Australia, Africa, South Africacraton

Abstract: Field evidence from the Pilbara craton (Australia) and Kaapvaal craton (South Africa) indicate that modern tectonic processes may have been operating at ca. 3.2 Ga, a time also associated with a high density of preserved Archaean impact indicators. Recent work has suggested a causative association between large impacts and tectonic processes for the Hadean. However, impact flux estimates and spherule bed characteristics suggest impactor diameters of <100 km at ca. 3.5 Ga, and it is unclear whether such impacts could perturb the global tectonic system. In this work, we develop numerical simulations of global tectonism with impacting effects, and simulate the evolution of these models throughout the Archaean for given impact fluxes. We demonstrate that moderate-size (?70 km diameter) impactors are capable of initiating short-lived subduction, and that the system response is sensitive to impactor size, proximity to other impacts, and also lithospheric thickness gradients. Large lithospheric thickness gradients may have first appeared at ca. 3.5-3.2 Ga as cratonic roots, and we postulate an association between Earth’s thermal maturation, cratonic root stability, and the onset of widespread sporadic tectonism driven by the impact flux at this time.
DS201412-0549
2014
Bottke, W.F.Marchi, S., Bottke, W.F., Elkins-Tanton, M., Bierhaus, K., Wuennemann, A., Morbidelli, Kring, D.A.Wide spread mixing and burial of Earth's Hadean crust by asteroid impacts.Nature, Vol. 511, July 31, pp. 578-582.GlobalGeochronology - zircons
DS201902-0284
2019
Bottke, W.F.Keller, C.B., Husson, J.M., Mitchell, R.N., Bottke, W.F., Gernon, T.M., Boehnke, P., Bell, E.A., Swanson-Hysell, N.L., Peters, S.E.Neoproterozoic glacial origin of the Great Unconformity.PNAS, pnas.org/cqi/doi/10.1073/ pnas.1804350116 10p.Mantlegeomorphology

Abstract: The Great Unconformity, a profound gap in Earth’s stratigraphic record often evident below the base of the Cambrian system, has remained among the most enigmatic field observations in Earth science for over a century. While long associated directly or indirectly with the occurrence of the earliest complex animal fossils, a conclusive explanation for the formation and global extent of the Great Unconformity has remained elusive. Here we show that the Great Unconformity is associated with a set of large global oxygen and hafnium isotope excursions in magmatic zircon that suggest a late Neoproterozoic crustal erosion and sediment subduction event of unprecedented scale. These excursions, the Great Unconformity, preservational irregularities in the terrestrial bolide impact record, and the first-order pattern of Phanerozoic sedimentation can together be explained by spatially heterogeneous Neoproterozoic glacial erosion totaling a global average of 3-5 vertical kilometers, along with the subsequent thermal and isostatic consequences of this erosion for global continental freeboard.
DS201902-0297
2019
Bottke, W.F.Mazourel, S., Ghent, R.R., Bottke, W.F., Parker, A.H., Gernon, T.M.Earth and Moon impact flux increased at the end of the Paleozoic. Craters almost abscent older than 650 mln years. Kimberlite ages used.Science, Vol. 363, 6424, Jan. 18, pp. 253-257.Globalgeochronology
DS201908-1798
2019
Bottke, W.F.Mzrouei, S., Ghent, R.R., Bottke, W.F., Parker, A.H., Gernon, T.M.Response to comment on "Earth and Moon impact flux increased at the end of the Paleozoic".Science, Vol. 365, 6450, 8p. eaaw9895 July 19MantleCraton

Abstract: Hergarten et al. interpret our results in terms of erosion and uncertain calibration, rather than requiring an increase in impact flux. Geologic constraints indicate low long-term erosion rates on stable cratons where most craters with diameters of ?20 kilometers occur. We statistically test their proposed recalibration of the lunar crater ages and find that it is disfavored relative to our original calibration.
DS1910-0264
1912
Bottomley, H. Col.Bottomley, H. Col.The River Diggers' AverageSouth African Mining Journal, Vol. 22, PT. 1, SEPT. 28TH. P. 101.South AfricaMineral Economics, Earnings
DS1991-1905
1991
Bottrell, S.H.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
DS1998-0143
1998
Bottrill, T.Bottrill, T., Sheahan, P.The first age of giant ore formation: stratigraphy, tectonics and mineralization Late Archean Early ProtPros. Developers Assoc, Short course 162pCanada, GlobalBook - table of contents, Metallogeny, Greenstone belts
DS1999-0085
1999
Botvinovsky, V.V.Botvinovsky, V.V.Differential current loop at boundary of Earth's inner core as a model of source of the major magnetic fieldRussian Geology and Geophysics, Vol. 40, No. 9, pp. 1355-MantleCore - boundary, Geophysics - magnetics
DS201312-0088
2013
Bou, P.Bou, P., Poli, P., Campillo, M., Pedersen, H., Briand, X., Roux, P.Teleseismic correlations of ambient seismic noise for deep global imaging of the Earth.Geophysical Journal International, Vol. 194, 2, pp. 844-848.MantleGeophysics - seismics
DS200912-0189
2009
BouabdellahDuggen, K.A., Hoernle, F., Hauff, A., Klugel, M., Bouabdellah, Thirwall, M.F.Flow of Canary mantle plume material through a subcontinental lithospheric corridor beneath Africa to the Mediterranean.Geology, Vol. 37, 3, pp. 283-286.EuropePlume
DS201012-0068
2010
Bouabdellah, M.Bouabdellah, M., Hoernle,K., Kchit, A., Duggen, S., Hauff, Klugel, Lowry, BeaudoinPetrogenesis of the Eocene Tamzert continental carbonatites ( central High Atlas, Morocco): implications for a common source for Tamzert and CanaryJournal of Petrology, Vol. 51, 8, pp. 1655-1686.Europe, Canary Islands, MoroccoCarbonatite
DS200612-0590
2006
Bouabdelli, M.Hoepffner, C., Houari, M.R., Bouabdelli, M.Tectonics of the North African Variscides ( Morocco, western Algeria): an outline.Comptes Rendus Geoscience, Vol. 338, 1-2, pp. 25-40.Africa, Morocco, AlgeriaTectonics
DS200612-0591
2006
Bouabdelli, M.Hoepffner, C., Rachid Houari, M., Bouabdelli, M.Tectonics of the North African Variscides ( Morocco, western Algeria) - an outline.Comptes Rendus Geoscience, Vol. 338, 1-2, pp. 25-Africa, MoroccoTectonics
DS1992-0149
1992
Bouabdli, A.Bouabdli, A., Liotard, J.M.Kimberlite-like magmatism for the ultrabasic lamprophyres in the carbonatitic massif of Tamazert( High Atlas, Morocco).(in French)Comptes Rendus AC, S, II, (in French), Vol. 314, No. 4, Feb. 13, pp. 351-357. hg594MoroccoLamprophyres, Carbonatite
DS201909-2022
2019
Bouali, A.Benaouda, R., Kraemer, D., Sitnikova, M., Goldmann, S., Freitag, R., Bouali, A., Mouttaqi, A., El Haloui, R., Essaadaoui, M., Bau, M.Thorium-poor monazite and columbite-(Fe) mineralization in the Gleibat Lafhouda carbonatite and its associated iron-oxide-apatite deposit of the Ouled Dlim Massif, South Morocco.Gondwana Research, Vol. 77, pp. 19-39.Africa, MoroccoREE

Abstract: Recent exploration work in South Morocco revealed the occurrence of several carbonatite bodies, including the Paleoproterozoic Gleibat Lafhouda magnesiocarbonatite and its associated iron oxide mineralization, recognized here as iron-oxide-apatite (IOA) deposit type. The Gleibat Lafhouda intrusion is hosted by Archean gneiss and schist and not visibly associated with alkaline rocks. Metasomatized micaceous rocks occur locally at the margins of the carbonatite outcrop and were identified as glimmerite fenite type. Rare earth element (REE) and Nb mineralization is mainly linked to the associated IOA mineralization and is represented by monazite-(Ce) and columbite-(Fe) as major ore minerals. The IOA mineralization mainly consists of magnetite and hematite that usually contain large apatite crystals, quartz and some dolomite. Monazite-(Ce) is closely associated with fluorapatite and occurs as inclusions within the altered parts of apatite and along cracks or as separate phases near apatite. Monazite shows no zonation patterns and very low Th contents (<0.4?wt%), which would be beneficial for commercial extraction of the REE and which indicates monazite formation from apatite as a result of hydrothermal volatile-rich fluids. Similar monazite-apatite mineralization and chemistry also occurs at depth within the carbonatite, although the outcropping carbonatite is barren, suggesting an irregular REE ore distribution within the carbonatite body. The barren carbonatite contains some tiny unidentified secondary Nb-Ta-U phases, synchysite and monazite. Niobium mineralization is commonly represented by anhedral minerals of columbite-(Fe) which occur closely associated with magnetite-hematite and host up to 78?wt% Nb2O5, 7?wt% Ta2O5 and 1.6?wt% Sc2O3. This association may suggest that columbite-(Fe) precipitated by an interaction of Nb-rich fluids with pre-existing Fe-rich minerals or as pseudomorphs after pre-existing Nb minerals like pyrochlore. Our results most strongly suggest that the studied mineralization is economically important and warrants both, further research and exploration with the ultimate goal of mineral extraction.
DS201808-1729
2018
Boublier, M.P.Calvert, A.J., Boublier, M.P.Archean continental spreading inferred from seismic images of the Yilgarn Craton.Nature Geoscience, Vol. 11, 7, pp. 526-530.Australiageophysics - seismic

Abstract: On the early Earth, oceanic plateaux similar to present-day Iceland are thought to have evolved into less dense microcontinents as they thickened by continued melt intrusion and crustal fractionation. These earliest continents may have been so weak on a hotter Earth that they collapsed laterally in response to thickening by further magmatic growth or tectonic imbrication. This continental spreading is likely to have resulted in the development of pervasive ductile strain fabrics in the deeper crust, which, if preserved, could generate seismic reflections. Here we present seismic images from the ancient core of the Archaean Yilgarn Craton of Australia that reveal shallowly dipping to horizontal reflections that pervade the middle and lower crust. We interpret these reflective fabrics as the result of widespread lateral crustal flow during the late stage of craton evolution approximately 2.66 to 2.61?billion years ago, which coincided with the widespread intrusion of high-temperature crustal melts, as thickened early continental crust collapsed. The consequent subsidence of large regions of the upper crust, including volcanic and sedimentary greenstone rocks, in the hanging walls of listric mid-lower crustal ductile flow fabrics caused these rocks to drop beneath the granitic melts rising towards the surface, and did not involve Rayleigh-Taylor instabilities within a mostly mobile crust.
DS1994-0188
1994
Bouchard, C.Bouchard, C.Les criteres de qualite du diamant.(in French)Seventh Colloque Annuel en Ressources Minerales, Universite du Quebec a, p. 11. abstract in FrenchQuebecDiamond -gemology
DS200612-0154
2006
Bouchard, G.Bouchard, G.Mineral exploration. deposit appraisal and mine complex development activity in Canada.Minerals and Metals Sector, Natural Resources Canada, Canadian Minerals Yearbook for 2004., 44 p. includes 8 text and graphs, tablesCanadaReview - exploration information
DS1989-0875
1989
Bouchard, J.G.Lemieux, A., Bouchard, J.G., Cranstone, D.A.Canadian Mines: perspective from 1988. Production, development andexplorationEnergy Mines and Resources, Mineral Bulletin No. 221, 45p. Database # 17921CanadaEconomics, Exploration
DS1985-0076
1985
Bouchard, M.A.Bouchard, M.A., Martineau, G.Southeastward Ice Flow in Central Quebec and its Paleogeographic Significance.Canadian Journal of Earth Sciences., Vol. 22, No. 10, OCTOBER PP. 1536-1541Canada, QuebecGeomorphology
DS1989-0151
1989
Bouchard, M.A.Bouchard, M.A., Salonen, V.P.Glacial dispersal of boulders in the James Bay Lowlands of Quebec, SOURCE[ BoreasBoreas, Vol. 18, No. 3, pp. 189-200QuebecGeomorphology, James Bay area
DS200412-1707
2004
Boucher, D.Russell, H.A.J., McClenaghan, M.B., Boucher, D., Sobie, P.Kimberlite indicator minerals distribution in eskers, Lake Timiskaming kimberlite field, Ontario and Quebec: preliminary resultsGeological Association of Canada Abstract Volume, May 12-14, SS14-03 p. 262.abstractCanada, Ontario, Lake TemiskamingGeochemistry, geomorphology
DS1998-0781
1998
Boucher, D.R.Kong, J.M., Boucher, D.R., Scott Smith, B.H.Exploration and geology of the Attawapiskat kimberlites, James Bay Northern Ontario.7th International Kimberlite Conference Abstract, pp. 446-8.OntarioGeology - exploration history, textures, geochronology, Deposit - Attawapiskat
DS1999-0062
1999
Boucher, D.R.Biazzarro, M., Stevenson, R.K., Boucher, D.R.Mantle xenoliths from southeastern Greenland: implications for the evolution and composition of the lithosphere North Atlantic Craton.Geological Association of Canada (GAC) Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC)., Vol. 24, p. 11. abstractGreenland, Labrador, Quebec, UngavaXenoliths
DS1993-0144
1993
Boucher, M.A.Boucher, M.A.Diamonds... draft for Canadian Minerals YearbookCanadian Minerals Yearbook, Review -, 14pCanadaBrief outline of activity, Tables of trade, production in world
DS1998-0144
1998
Boucher, M.A.Boucher, M.A., Boyd, B.Diamonds; Canadian Minerals Yearbook, 1998Canadian Minerals Yearbook, Section 22, 16p.Canada, Northwest Territories, Alberta, SaskatchewanDiamond - exploration overview
DS201212-0581
2012
Boucher, R.A.Reid, M.R., Boucher, R.A., Ichert-Toft, J., Levander, A., Liu, K., Miller, M.S., Ramos, F.C.Melting under the Colorado Plateau, USA.Geology, Vol. 40, 5, pp. 387-390.United States, Colorado PlateauMelting
DS201112-0854
2011
Bouchet, R.A.Reid, M.R., Bouchet, R.A., Blichert-Toft, J.Melting conditions associated with the Colorado Plateau, USA.Goldschmidt Conference 2011, abstract p.1704.United States, Colorado PlateauThermobarometry
DS2002-0056
2002
Bouchez, J.L.Archanjo, C.J., Trindade, R.I.,Bouchez, J.L., ErnestoGranite fabrics and regional scale strain partitioning in the Serido belt Boroborema Province NE Brasil.Tectonics, Vol.21,1,Feb.pp.3-1,3-14.BrazilStructure
DS1992-0115
1992
Bouchez, J-L.Benn, K., Sawyer, E.W., Bouchez, J-L.Orogen parallel and transverse shearing in the Opatica belt, Quebec:implications for the structure of the Abitibi SubprovinceCanadian Journal of Earth Sciences, Vol. 29, No. 11, November, pp. 2429-2444QuebecTectonics, Structure
DS2003-0140
2003
BouchonBouchon, ValleeSupersize shearsScience, No. 5634, Aug. 8, p. 824.MantleGeodynamics - structure
DS200412-0187
2003
BouchonBouchon, ValleeSupersize shears.Science, No. 5634, Aug. 8, p. 824.MantleGeodynamics - structure
DS1997-0782
1997
Bouchot, V.Milesi, J.P., Bouchot, V., Ledru, P.Cartographie et metallogenie 3D du Massif central francaisChron. Recherche Miniere, No. 528, Sept. pp. 3-12FranceMetallogeny, Mapping - hydrothermal, geochronology
DS1992-0040
1992
Boudase, K.V.Ariskin, A.A., Boudase, K.V., Meshalkin, S.S., Tsekhonya, T.I.Inforex: a dat a base on experimental studies of phase relations in silicatesystemsAmerican Mineralogist, Vol. 77, No. 5, 6, May-June pp. 668-670GlobalComputer, Program -Inforex
DS201707-1339
2017
Bouden, N.Kitayama, Y., Thomassot, E., Galy, A., Golovin, A., Korsakov, A., d'Eyrames, E., Assayag, N., Bouden, N., Ionov, D.Co-magmatic sulfides and sulfates in the Udachnaya-East pipe ( Siberia): a record of the redox state and isotopic composition of sulfur in kimberlites and their mantle sources.Chemical Geology, Vol. 455, pp. 315-330.Russiadeposit - Udachnaya East

Abstract: Kimberlites of the Udachnaya-East pipe (Siberia) include a uniquely dry and serpentine-free rock type with anomalously high contents of chlorine (Cl ? 6.1 wt%), alkalies (Na2O + K2O ? 10 wt%) and sulfur (S ? 0.50 wt%), referred to as a “salty” kimberlite. The straightforward interpretation is that the Na-, K-, Cl- and S-rich components originate directly from a carbonate-chloride kimberlitic magma that is anhydrous and alkali-rich. However, because brines and evaporites are present on the Siberian craton, previous studies proposed that the kimberlitic magma was contaminated by the assimilation of salt-rich crustal rocks. To clarify the origin of high Cl, alkalies and S in this unusual kimberlite, here we determine its sulfur speciation and isotopic composition and compare it to that of non-salty kimberlites and kimberlitic breccia from the same pipe, as well as potential contamination sources (hydrothermal sulfides and sulfates, country-rock sediment and brine collected in the area). The average ?34S of sulfides is ? 1.4 ± 2.2‰ in the salty kimberlite, 2.1 ± 2.7‰ in the non-salty kimberlites and 14.2 ± 5.8‰ in the breccia. The average ?34S of sulfates in the salty kimberlites is 11.1 ± 1.8‰ and 27.3 ± 1.6‰ in the breccia. In contrast, the ?34S of potential contaminants range from 20 to 42‰ for hydrothermal sulfides, from 16 to 34‰ for hydrothermal sulfates, 34‰ for a country-rock sediment (Chukuck suite) and the regional brine aquifer. Our isotope analyses show that (1) in the salty kimberlites, neither sulfates nor sulfides can be simply explained by brine infiltration, hydrothermal alteration or the assimilation of known salt-rich country rocks and instead, we propose that they are late magmatic phases; (2) in the non-salty kimberlite and breccia, brine infiltration lead to sulfate reduction and the formation of secondary sulfides – this explains the removal of salts, alkali-carbonates and sulfates, as well as the minor olivine serpentinization; (3) hydrothermal sulfur was added to the kimberlitic breccia, but not to the massive kimberlites. In situ measurements of sulfides confirm this scenario, clearly showing the addition of two sulfide populations in the breccia (pyrite-pyrrhotites with average ?34S of 7.9 ± 3.4‰ and chalcopyrites with average ?34S of 38.0 ± 0.4‰) whereas the salty and non-salty kimberlites preserve a unique population of djerfisherites (Cl- and K-rich sulfides) with ?34S values within the mantle range. This study provides the first direct evidence of alkaline igneous rocks in which magmatic sulfate is more abundant than sulfide. Although sulfates have been rarely reported in mantle materials, sulfate-rich melts may be more common in the mantle than previously thought and could balance the sulfur isotope budget of Earth's mantle.
DS202011-2033
2020
Bouden, N.Casola, V., France, L., Galy, A., Bouden, N., Villeneuve, J.No evidence for carbon enrichment in the mantle source of carbonatites in eastern Africa.Geology, Vol. 48, 10, pp. 971976. pdfAfrica, Tanzaniadeposit - Oldoinyo Lengai

Abstract: Carbonatites are unusual, carbon-rich magmas thought to form either by the melting of a carbon-rich mantle source or by low-degree partial melting of a carbon-poor (<80 ppm C) mantle followed by protracted differentiation and/or immiscibility. Carbonate-bearing mantle xenoliths from Oldoinyo Lengai (East African Rift), the only active volcano erupting carbonatites, have provided key support for a C-rich mantle source. Here, we report unique microscale O and C isotopic analyses of those carbonates, which are present as interstitial grains in the silicate host lava, veins in the xenoliths, and pseudo-inclusions in olivine xenoliths. The ?18O values vary little, from 19‰ to 29‰, whereas ?13C values are more variable, ranging from -23‰ to +0.5‰. We show that such carbonate ?18O values result from the low-temperature precipitation of carbonate in equilibrium with meteoric water, rather than under mantle conditions. In this framework, the observed ?13C values can be reproduced by Rayleigh distillation driven by carbonate precipitation and associated degassing. Together with petrological evidence of a physical connection between the three types of carbonates, our isotopic data support the pedogenic formation of carbonates in the studied xenoliths by soil-water percolation and protracted crystallization along xenolith cracks. Our results refute a mechanism of C enrichment in the form of mantle carbonates in the mantle beneath the Natron Lake magmatic province and instead support carbonatite formation by low-degree partial melting of a C-poor mantle and subsequent protracted differentiation of alkaline magmas.
DS202012-2210
2020
Bouden, N.Casola, V., France, L., Galy, A., Bouden, N., Villeneuve, J.No evidence for carbon enrichment in the mantle source of carbonatites in eastern Africa.Geology, Vol. 48, 10, 5p. PdfAfrica, Tanzaniacarbonatites

Abstract: Carbonatites are unusual, carbon-rich magmas thought to form either by the melting of a carbon-rich mantle source or by low-degree partial melting of a carbon-poor (<80 ppm C) mantle followed by protracted differentiation and/or immiscibility. Carbonate-bearing mantle xenoliths from Oldoinyo Lengai (East African Rift), the only active volcano erupting carbonatites, have provided key support for a C-rich mantle source. Here, we report unique microscale O and C isotopic analyses of those carbonates, which are present as interstitial grains in the silicate host lava, veins in the xenoliths, and pseudo-inclusions in olivine xenoliths. The ?18O values vary little, from 19‰ to 29, whereas ?13C values are more variable, ranging from -23‰ to +0.5‰. We show that such carbonate ?18O values result from the low-temperature precipitation of carbonate in equilibrium with meteoric water, rather than under mantle conditions. In this framework, the observed ?13C values can be reproduced by Rayleigh distillation driven by carbonate precipitation and associated degassing. Together with petrological evidence of a physical connection between the three types of carbonates, our isotopic data support the pedogenic formation of carbonates in the studied xenoliths by soil-water percolation and protracted crystallization along xenolith cracks. Our results refute a mechanism of C enrichment in the form of mantle carbonates in the mantle beneath the Natron Lake magmatic province and instead support carbonatite formation by low-degree partial melting of a C-poor mantle and subsequent protracted differentiation of alkaline magmas.
DS1985-0077
1985
Boudier, F.Boudier, F., Nicolas, A.Harzburgite and lherzolite subtypes in ophiolitic and oceanicenvironmentsEarth Planet. Sci. Letters, Vol. 76, pp. 84-92Newfoundland, Cyprus, PhilippinesLherzolite, Ophiolite
DS1989-0152
1989
Boudier, F.Boudier, F., Le Sueur, E., Nicolas, A.Structure of an atypical ophiolite: the Trinity Complex, easternKlamathMountains, CaliforniaGeological Society of America (GSA) Bulletin, Vol. 101, No. 6, June pp. 820-833CaliforniaOphiolite, Trinity Complex
DS1991-0156
1991
Boudier, F.Boudier, F.Olivine xenocrysts in picritic magmas- an experimental and microstructuralstudyContributions to Mineralogy and Petrology, Vol. 109, No. 1, pp. 114-123GlobalMicroprobe spectrometry, Olivine xenocrysts
DS1993-0710
1993
Boudier, F.Ildefonse, B., Nicolas, A., Boudier, F.Evidence from the Oman ophiolite for sudden stress changes during melt injection at oceanic spreading centresNature, Vol. 366, December 16, pp. 673-674OmanOphiolite, Magma
DS1994-1276
1994
Boudier, F/.Nicolas, A., Boudier, F/., Ildefonse, B.Evidence from the Oman ophiolite for active mantle upwelling beneath a fast spreading ridgeNature, Vol. 370, No. 6484, July 7, pp.51-53OmanOphiolite, Plumes
DS1988-0073
1988
Boudier, N.F.Boudier, N.F., Ceuleneer, G.Mantle flow patterns and magma chambers at ocean ridges:evidence from the Oman ophioliteMarine Geophysical Researches, Vol. 9, pp. 293-310. Database # 17650OmanOphiolite, Structure
DS1994-0189
1994
Boudreau, A.E.Boudreau, A.E.Mineral segregation during crystal ageing in two crystal two componentsystemsSouth African Journal of Geology, Vol. 97, No. 4, pp. 473-485South AfricaLayered intrusions, Crystallography
DS1995-0184
1995
Boudreau, A.E.Boudreau, A.E.Crystal ageing and the formation of the fine scale igneous layeringMineralogy and Petrology, Vol. 54, No. 1-2, pp. 55-70GlobalLayered intrusion
DS1995-0185
1995
Boudreau, A.E.Boudreau, A.E., Love, C., Prendergast, M.D.Halogen geochemistry of the Great Dyke, ZimbabweContributions to Mineralogy and Petrology, Vol. 122, No. 3, pp. 289-300Zimbabweplatinum group elements (PGE), Layered intrusion, Platinum, nickel, chromite, Deposit -Great Dyke
DS1997-0117
1997
Boudreau, A.E.Boudreau, A.E., McBirney, A.R.The Skaergaard layered series: part III non-dynamic layeringJournal of Petrology, Vol. 38, No. 8, Aug. 1, pp. 1003-1020GreenlandLayered intrusion, Deposit - Skaergaard
DS1996-0990
1996
Boudreau, M.A.Moorhead, J., Girard, R., Boudreau, M.A.Anomalies aeromagnetic circulars possiblement reliees a des intrusions de kimberlite dans le nord ouest QuebecQuebec Department of Mines, MB 93-49, 23p.Quebec, Ungava, LabradorGeophysics - magnetics
DS1993-1069
1993
Boudreau, M-A.Moorhead, J., Girard, R., Boudreau, M-A.Circular aeromagnetic anomalies possibly related to kimberlite intrusions in northwest Quebec.Quebec Department of Mines preliminary promotion document, handout at PDA, 25p. 5 p. text and listing of anomalies by locationQuebecGeophysics, Aeromagnetic anomalies
DS1992-0700
1992
Boudreault, F.Hendricks, C., Scoble, M.J., Boudreault, F., Szymanski, J.Blasthole stoping: drilling accuracy and measurementTransactions of the Institute of Mining and Metallurgy (IMM), Vol. 101, Sept-Dec, pp. A 173-186GlobalDrilling -blasthole stoping, Overview of advances
DS1994-0759
1994
Boudreault, F.Hendricks, C., Scobie, M., Boudreault, F.A study of blasthole drilling accuracy: monitoring instrumentation andpracticeThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin), Vol. 87, No. 977, February pp. 60-66ManitobaDrilling, Mining -dilution
DS1998-1539
1998
BoudriasVerpaelst, P., Perreault, S., Brisebois, D., BoudriasGeologie de la region de la riviere Koroc, Grand NordQuebec Department of Mines, DV 98-05, p. 35.QuebecGeology
DS1991-1079
1991
Boudzoumou, F.Maurin, J.C., Boudzoumou, F., Djama, L.M., Gloan, P., Michard, A.The Proterozoic West Congolian belt and its foreland in Congo-newComptes Rendu Academy of Science Ser. II, Mec. Phys., (in French), Vol. 312, No. 11, pp. 1327-1334Central AfricaProterozoic, Geochronology
DS1991-1080
1991
Boudzoumou, F.Maurin, J-C., Boudzoumou, F., Diama, L-M., Gioan, P., Michard, A.The Proterozoic of west Congolian belt and its foreland in Congo: newC.r. Academy Of Science Paris, Ser. Ii, Vol. 312, No. ser II, pp. 1327-1334Central Africa, CongoGeochronology, Structure
DS1995-0009
1995
Boudzoumou, F.Affaton, P., Trompette, R., Uhlein, A., Boudzoumou, F.The Panafrican Brasiliano Aracuai West Congo fold belt in the framework Of western Gondwana aggregation 600MaGeological Society Africa 10th. Conference Oct. Nairobi, p. 20. AbstractWest Africa, BrazilTectonics, Rodinia Supercontinent
DS1990-0203
1990
Bougault, H.Bienvenu, P., Bougault, H., Joron, J.L., Treuil, M., Dmitriev, L.Mid Ocean Ridge Basalt (MORB) alteration: rare earth element/non-rare earth hydromagmaphile elementfractionationChemical Geology, Vol. 82, No. 1/2, March 30, pp. 1-14GlobalMagma genesis, Mid Ocean Ridge Basalt (MORB) alteration
DS2002-1673
2002
Bougault, H.Vlastelic, I., Bougault, H., Dosso, L.Heterogeneous heat production in the Earth's upper mantle: blob melting and MORB composition.Earth and Planetary Science Letters, Vol.199,1-2,pp.157-72., Vol.199,1-2,pp.157-72.MantleMelting
DS2002-1674
2002
Bougault, H.Vlastelic, I., Bougault, H., Dosso, L.Heterogeneous heat production in the Earth's upper mantle: blob melting and MORB composition.Earth and Planetary Science Letters, Vol.199,1-2,pp.157-72., Vol.199,1-2,pp.157-72.MantleMelting
DS201612-2318
2016
Bouguerra, A.Lustrino, M., Agostini, S., Chalal, Y., Fedele, L., Stagno, V., Colombi, F., Bouguerra, A.Exotic lamproites or normal ultrapotassic rocks? The Late Miocene volcanic rocks from Kef Hahouner, NE Algeria, in the frame of the circum-Mediterranean lamproites.Journal of Volcanology and Geothermal Research, in press available 15p.Africa, AlgeriaLamproite

Abstract: The late Miocene (11-9 Ma) volcanic rocks of Kef Hahouner, ~ 40 km NE of Constantine (NE Algeria), are commonly classified as lamproites in literature. However, these rocks are characterized by an anhydrous paragenesis with plagioclase and Mg-rich olivine phenocrysts, set in a groundmass made up of feldspars, pyroxenes and opaque minerals. Thus, we classify the Kef Hahouner rocks as ultrapotassic shoshonites and latites, having K2O > 3 wt.%, K2O/Na2O > 2.5, MgO > 3-4 wt.%, SiO2 < 55-57 wt.% and SiO2/K2O < 15. All the investigated samples show primitive mantle-normalized multi-element patterns typical of orogenic (arc-type) magmas, i.e. enriched in LILE (e.g. Cs, Rb and Ba) and LREE (e.g. La/Yb = 37-59) with respect to the HFSE, peaks at Pb and troughs at Nb and Ta. Initial isotopic ratios are in the range of 87Sr/86Sr = 0.70874-0.70961, 143Nd/144Nd = 0.51222-0.51223, 206Pb/204Pb = 18.54-18.60, 207Pb/204Pb = 15.62-15.70 and 208Pb/204Pb = 38.88-39.16. The Kef Hahouner volcanic rocks show multi-element patterns similar to the other circum-Mediterranean lamproites and extreme Sr, Nd and Pb isotopic compositions. Nevertheless, the abundant plagioclase, the presence of Al-rich augite coupled with high Al2O3 whole rock compositions (9.6-21.4 wt.%), and the absence of phlogopite are all at inconsistent with the definition of lamproite. We reviewed the rocks classified as lamproites worldwide, and found that many of these rocks, as for the Kef Hahouner samples, should be actually defined as "normal" potassic to ultrapotassic volcanic rocks. Even the grouping of lamproites into "orogenic" and "anorogenic" types appears questionable.
DS1995-0186
1995
Bouhallier, H.Bouhallier, H., Chardon, D., Choukroune, P.Strain patterns in Archean dome and basin structures: the Dharwar craton, Karnataka South IndiaEarth and Planetary Science Letters, Vol. 135, No. 1, Oct. 1, pp. 57-IndiaStructure, Craton
DS201412-0987
2014
Bouhifd, A.Wood, B., Fei, Y., Sharar, A., Corgne, A., Bouhifd, A.Formation and evolution and composition of Earth's core.Goldschmidt Conference 2014, 1p. AbstractMantleCore
DS200712-0353
2006
Bouhifd, M.A.Gautron, L., Greaux, S., Andrault, D., Bolfan Casanova, N., Guignot,N., Bouhifd, M.A.Uranium in the Earth's lower mantle.Geophysical Research Letters, Vol. 33, 23, Dec. 16, L23301MantleUranium
DS200812-0520
2008
Bouhifd, M.A.Jephcoat, A.P., Bouhifd, M.A., Porcelli, D.Metal silicate element partitioning at ultrahigh pressures: He to I.Goldschmidt Conference 2008, Abstract p.A427.TechnologyLHDAC
DS201012-0008
2010
Bouhifd, M.A.Andrault, D., Nigro, G., Bolfan-Casanova, N., Bouhifd, M.A., Garbarino, G., Mezouar, M.Melting curve of the lowermost Earth's mantle.Goldschmidt 2010 abstracts, abstractMantleMelting
DS201112-0020
2011
Bouhifd, M.A.Andrault, D., Bolfan-Casanova, N., loNigro, G., Bouhifd, M.A., Garbarino, G., Mezouar, M.Solidus and liquidus profiles of chrondritic mantle: implications for melting of the Earth across its history.Earth and Planetary Science Letters, Vol. 304, 1-2, pp. 251-259.MantleMelting
DS201112-0021
2011
Bouhifd, M.A.Andrault, D., Lo Nigro, G., Bolfan-Casanova, N., Bouhifd, M.A., Garbarino, G., Mezouar, M.Melting properties of chronditic mantle to the core mantle boundary.Goldschmidt Conference 2011, abstract p.438.MantleMelting
DS201312-0089
2013
Bouhifd, M.A.Bouhifd, M.A., Andrault, D., Bolfan-Casanova, N.Thermodynamics of lower mantle minerals.Goldschmidt 2013, AbstractMantleMineralogy
DS201503-0135
2015
Bouhifd, M.A.Bouhifd, M.A., Boyet, M., Cartier, C., Hammouda, T., Bofan-Casanova, N., Devidal, J.L., Andrault, D.Superchondritic Sm/Nd ratio of the Earth: impact of Earth's core formation.Earth and Planetary Science Letters, Vol. 413, March 1, pp. 158-166.MantleGeochronology

Abstract: This study investigates the impact of Earth's core formation on the metal-silicate partitioning of Sm and Nd, two rare-earth elements assumed to be strictly lithophile although they are widely carried by the sulphide phases in reducing material (e.g. enstatite chondrites). The partition coefficients of Sm and Nd (DSmDSm and DNdDNd) between molten CI and EH chondrites model compositions and various Fe-rich alloys (in the Fe-Ni-C-Si-S system) have been determined in a multi-anvil between 3 and 26 GPa at various temperatures between 2073 and 2440 K, and at an oxygen fugacity ranging from 1 to 5 log units below the iron-wüstite (IW) buffer. The chemical compositions of the run products and trace concentrations in Sm and Nd elements were determined using electron microprobe and laser ablation inductively coupled plasma-mass spectrometry. Our results demonstrate the non-fractionation of Sm and Nd during the segregation of the metallic phases: the initial Sm/Nd ratio of about 1 in the starting materials yields precisely the same ratio in the recovered silicate phases after the equilibration with the metal phases at all conditions investigated in this study. In addition, DSmDSm and DNdDNd values range between 10?310?3 and 10?510?5 representing a low solubility in the metal. An increase of the partition coefficients is observed with decreasing the oxygen fugacity, or with an increase of S content of the metallic phase at constant oxygen fugacity. Thus, based on the actual Sm and Nd concentrations in the bulk Earth, the core should contain less than 0.4 ppb for Sm and less than 1 ppb for Nd. These estimates are three orders of magnitude lower than what would be required to explain the reported 142Nd excess in terrestrial samples relative to the mean chondritic value, using the core as a Sm-Nd complementary reservoir. In other words, the core formation processes cannot be responsible for the increase of the Sm/Nd ratio in the mantle early in Earth history.
DS201707-1309
2017
Bouhifd, M.A.Bouhifd, M.A., Clesi, V., Boujibar, A., Cartier, C., Hammouda, T., Boyet, M., Manthilake, G., Monteux, J., Andrault, D.Silicate melts during the Earth's core formation.Chemical Geology, Vol. 461, pp. 128-139.Mantlemelting

Abstract: Accretion from primordial material and its subsequent differentiation into a planet with core and mantle are fundamental problems in terrestrial and solar system. Many of the questions about the processes, although well developed as model scenarios over the last few decades, are still open and much debated. In the early Earth, during its formation and differentiation into rocky mantle and iron-rich core, it is likely that silicate melts played an important part in shaping the Earth's main reservoirs as we know them today. Here, we review several recent results in a deep magma ocean scenario that give tight constraints on the early evolution of our planet. These results include the behaviour of some siderophile elements (Ni and Fe), lithophile elements (Nb and Ta) and one volatile element (Helium) during Earth's core formation. We will also discuss the melting and crystallization of an early magma ocean, and the implications on the general feature of core-mantle separation and the depth of the magma ocean. The incorporation of Fe2 + and Fe3 + in bridgmanite during magma ocean crystallization is also discussed. All the examples presented here highlight the importance of the prevailing conditions during the earliest time of Earth's history in determining the composition and dynamic history of our planet.
DS201711-2499
2017
Bouhifd, M.A.Andrault, D., Bolfan-Casanova, N., Bouhifd, M.A., Boujibar, A., Garbarino, G., Manthilake, G., Mezouar, M., Monteux, J., Parisiades, P., Pesce, G.Toward a coherent model for the melting behaviour of the deep Earth's mantle.Physics of the Earth and Planetary Interiors, Vol. 265, pp. 67-81.Mantlemelting

Abstract: Knowledge of melting properties is critical to predict the nature and the fate of melts produced in the deep mantle. Early in the Earth’s history, melting properties controlled the magma ocean crystallization, which potentially induced chemical segregation in distinct reservoirs. Today, partial melting most probably occurs in the lowermost mantle as well as at mid upper-mantle depths, which control important aspects of mantle dynamics, including some types of volcanism. Unfortunately, despite major experimental and theoretical efforts, major controversies remain about several aspects of mantle melting. For example, the liquidus of the mantle was reported (for peridotitic or chondritic-type composition) with a temperature difference of ?1000 K at high mantle depths. Also, the Fe partitioning coefficient (DFeBg/melt) between bridgmanite (Bg, the major lower mantle mineral) and a melt was reported between ?0.1 and ?0.5, for a mantle depth of ?2000 km. Until now, these uncertainties had prevented the construction of a coherent picture of the melting behavior of the deep mantle. In this article, we perform a critical review of previous works and develop a coherent, semi-quantitative, model. We first address the melting curve of Bg with the help of original experimental measurements, which yields a constraint on the volume change upon melting (?Vm). Secondly, we apply a basic thermodynamical approach to discuss the melting behavior of mineralogical assemblages made of fractions of Bg, CaSiO3-perovskite and (Mg,Fe)O-ferropericlase. Our analysis yields quantitative constraints on the SiO2-content in the pseudo-eutectic melt and the degree of partial melting (F) as a function of pressure, temperature and mantle composition; For examples, we find that F could be more than 40% at the solidus temperature, except if the presence of volatile elements induces incipient melting. We then discuss the melt buoyancy in a partial molten lower mantle as a function of pressure, F and DFeBg/melt. In the lower mantle, density inversions (i.e. sinking melts) appear to be restricted to low F values and highest mantle pressures. The coherent melting model has direct geophysical implications: (i) in the early Earth, the magma ocean crystallization could not occur for a core temperature higher than ?5400 K at the core-mantle boundary (CMB). This temperature corresponds to the melting of pure Bg at 135 GPa. For a mantle composition more realistic than pure Bg, the right CMB temperature for magma ocean crystallization could have been as low as ?4400 K. (ii) There are converging arguments for the formation of a relatively homogeneous mantle after magma ocean crystallization. In particular, we predict the bulk crystallization of a relatively large mantle fraction, when the temperature becomes lower than the pseudo-eutectic temperature. Some chemical segregation could still be possible as a result of some Bg segregation in the lowermost mantle during the first stage of the magma ocean crystallization, and due to a much later descent of very low F, Fe-enriched, melts toward the CMB. (iii) The descent of such melts could still take place today. There formation should to be related to incipient mantle melting due to the presence of volatile elements. Even though, these melts can only be denser than the mantle (at high mantle depths) if the controversial value of DFeBg/melt is indeed as low as suggested by some experimental studies. This type of melts could contribute to produce ultra-low seismic velocity anomalies in the lowermost mantle.
DS201910-2295
2019
Bouhifd, M.A.Rizo, H., Abdrault, D., Bennett, N.R., Humayun, M., Brandon, A., Vlastelic, I., Moine, B., Poirier, A., Bouhifd, M.A., Murphy, D.T.182W evidence for core-mantle interaction in the source of mantle plumes.Geochemical Perspectives Letters, Vol. 11, pp. 6-11.Mantlemantle plumes, hotspots

Abstract: Tungsten isotopes are the ideal tracers of core-mantle chemical interaction. Given that W is moderately siderophile, it preferentially partitioned into the Earth’s core during its segregation, leaving the mantle depleted in this element. In contrast, Hf is lithophile, and its short-lived radioactive isotope 182Hf decayed entirely to 182W in the mantle after metal-silicate segregation. Therefore, the 182W isotopic composition of the Earth’s mantle and its core are expected to differ by about 200 ppm. Here, we report new high precision W isotope data for mantle-derived rock samples from the Paleoarchean Pilbara Craton, and the Réunion Island and the Kerguelen Archipelago hotspots. Together with other available data, they reveal a temporal shift in the 182W isotopic composition of the mantle that is best explained by core-mantle chemical interaction. Core-mantle exchange might be facilitated by diffusive isotope exchange at the core-mantle boundary, or the exsolution of W-rich, Si-Mg-Fe oxides from the core into the mantle. Tungsten-182 isotope compositions of mantle-derived magmas are similar from 4.3 to 2.7 Ga and decrease afterwards. This change could be related to the onset of the crystallisation of the inner core or to the initiation of post-Archean deep slab subduction that more efficiently mixed the mantle.
DS2002-0193
2002
Bouhild, M.A.Bouhild, M.A., Jephcoat, A.P.Metal silicate interactions at high pressure and temperature in the diamond anvil cell18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.77.MantleUHP mineralogy, Redox conditions
DS200512-0474
2005
Bouhnik-Le Coz, M.Jahn, B-M., Liu, X., Yui, T-F., Morin, N., Bouhnik-Le Coz, M.High pressure ultrahigh pressure eclogites from the Hong an Block, east central China: geochemical characterization, isotope disequilibrium and geochronological controversy.Contributions to Mineralogy and Petrology, On lineChinaUHP
DS201709-2027
2017
Bouihol, P.Magni, V., Allen, M.B., van Hunen, J., Bouihol, P.Continental underplating after slab break-off.Earth and Planetary Science Letters, Vol. 474, pp. 59-67.Mantle, India-Eurasiasubduction

Abstract: We present three-dimensional numerical models to investigate the dynamics of continental collision, and in particular what happens to the subducted continental lithosphere after oceanic slab break-off. We find that in some scenarios the subducting continental lithosphere underthrusts the overriding plate not immediately after it enters the trench, but after oceanic slab break-off. In this case, the continental plate first subducts with a steep angle and then, after the slab breaks off at depth, it rises back towards the surface and flattens below the overriding plate, forming a thick horizontal layer of continental crust that extends for about 200 km beyond the suture. This type of behaviour depends on the width of the oceanic plate marginal to the collision zone: wide oceanic margins promote continental underplating and marginal back-arc basins; narrow margins do not show such underplating unless a far field force is applied. Our models show that, as the subducted continental lithosphere rises, the mantle wedge progressively migrates away from the suture and the continental crust heats up, reaching temperatures >900?°C. This heating might lead to crustal melting, and resultant magmatism. We observe a sharp peak in the overriding plate rock uplift right after the occurrence of slab break-off. Afterwards, during underplating, the maximum rock uplift is smaller, but the affected area is much wider (up to 350 km). These results can be used to explain the dynamics that led to the present-day crustal configuration of the India–Eurasia collision zone and its consequences for the regional tectonic and magmatic evolution.
DS201904-0758
2019
Bouihol, P.Maunder, B. Hunen, J., Bouihol, P., Magni, V.Modeling slab temperature: a reevaluation of the thermal parameter.Geochemistry, Geophysics, Geosystems, Vol. 20, 2, pp. 673-687.MantleThermometry

Abstract: We reevaluate the effects of slab age, speed, and dip on slab temperature with numerical models. The thermal parameter ? = t v sin ?, where t is age, v is speed, and ? is angle, is traditionally used as an indicator of slab temperature. However, we find that an empirically derived quantity, in which slab temperature T ? log (t?av?b) , is more accurate at depths <120 km, with the constants a and b depending on position within the slab. Shallower than the decoupling depth (~70-80 km), a~1 and b~0, that is, temperature is dependent on slab age alone. This has important implications for the early devolatilization of slabs in the hottest (youngest) cases and for shallow slab seismicity. At subarc depths (~100 km), within the slab mantle, a~1 and b~0 again. However, for the slab crust, now a~0.5 and b~1, that is, speed has the dominant effect. This is important when considering the generation of arc magmatism, and in particular, slab melting and the generation of slab?derived melange diapirs. Moving deeper into the Earth, the original thermal parameter performs well as a temperature indicator, initially in the core of the slab (the region of interest for deep water cycling). Finally, varying the decoupling depth between 40 and 100 km has a dominant effect on slab temperatures down to 140?km depth, but only within the slab crust. Slab mantle temperature remains primarily dependent on age.
DS201711-2513
2017
Bouilhol, P.Freeburn, R., Bouilhol, P., Maunder, B., Magni, V., van Hunen, J.Numerical models of the magmatic processes induced by slab breakoff.Earth and Planetary Science Letters, Vol. 478, pp. 203-213.Mantlesubduction

Abstract: After the onset of continental collision, magmatism often persists for tens of millions of years, albeit with a different composition, in reduced volumes, and with a more episodic nature and more widespread spatial distribution, compared to normal arc magmatism. Kinematic modelling studies have suggested that slab breakoff can account for this post-collisional magmatism through the formation of a slab window and subsequent heating of the overriding plate and decompression melting of upwelling asthenosphere, particularly if breakoff occurs at depths shallower than the overriding plate. To constrain the nature of any melting and the geodynamic conditions required, we numerically model the collision of two continental plates following a period of oceanic subduction. A thermodynamic database is used to determine the (de)hydration reactions and occurrence of melt throughout this process. We investigate melting conditions within a parameter space designed to generate a wide range of breakoff depths, timings and collisional styles. Under most circumstances, slab breakoff occurs deeper than the depth extent of the overriding plate; too deep to generate any decompressional melting of dry upwelling asthenosphere or thermal perturbation within the overriding plate. Even if slab breakoff is very shallow, the hot mantle inflow into the slab window is not sustained long enough to sufficiently heat the hydrated overriding plate to cause significant magmatism. Instead, for relatively fast, shallow breakoff we observe melting of asthenosphere above the detached slab through the release of water from the tip of the heating detached slab. Melting of the subducted continental crust during necking and breakoff is a more common feature and may be a more reliable indicator of the occurrence of breakoff. We suggest that magmatism from slab breakoff alone is unable to explain several of the characteristics of post-collisional magmatism, and that additional geodynamical processes need to be considered when interpreting magmatic observations.
DS201805-0944
2018
Bouilhol, P.Eeken, T., Goes, S., Pedersen, H.A., Arndt, N.T., Bouilhol, P.Seismic evidence for depth dependent metasomatism in cratons.Earth Planetary Science Letters, Vol. 491, pp. 148-159.Africa, Australia, Canada, Europegeothermometry

Abstract: The long-term stability of cratons has been attributed to low temperatures and depletion in iron and water, which decrease density and increase viscosity. However, steady-state thermal models based on heat flow and xenolith constraints systematically overpredict the seismic velocity-depth gradients in cratonic lithospheric mantle. Here we invert for the 1-D thermal structure and a depth distribution of metasomatic minerals that fit average Rayleigh-wave dispersion curves for the Archean Kaapvaal, Yilgarn and Slave cratons and the Proterozoic Baltic Shield below Finland. To match the seismic profiles, we need a significant amount of hydrous and/or carbonate minerals in the shallow lithospheric mantle, starting between the Moho and 70 km depth and extending down to at least 100-150 km. The metasomatic component can consist of 0.5-1 wt% water bound in amphibole, antigorite and chlorite, ?0.2 wt% water plus potassium to form phlogopite, or ?5 wt% CO2 plus Ca for carbonate, or a combination of these. Lithospheric temperatures that fit the seismic data are consistent with heat flow constraints, but most are lower than those inferred from xenolith geothermobarometry. The dispersion data require differences in Moho heat flux between individual cratons, and sublithospheric mantle temperatures that are 100-200?°C less beneath Yilgarn, Slave and Finland than beneath Kaapvaal. Significant upward-increasing metasomatism by water and CO2-rich fluids is not only a plausible mechanism to explain the average seismic structure of cratonic lithosphere but such metasomatism may also lead to the formation of mid-lithospheric discontinuities and would contribute to the positive chemical buoyancy of cratonic roots.
DS201809-2014
2018
Bouillard, J-C.Daver, L., Bureau, H., Gaillou, E., Ferraris, C., Bouillard, J-C., Cartigny, P., Pinti, D.L.In situ analysis of inclusions in diamonds from collections.Goldschmidt Conference, 1p. AbstractGlobaldiamond inclusions

Abstract: Diamonds represent one of the few witnesses of our planet interior. They are mainly formed in the first 200 km of the lithospheric mantle, and, more rarely from the transition zone to 700 km deep. Diamonds contain a lot of information about global evolution, however their mode of formation remains poorly understood. Recent studies in high-pressure mineralogy suggest that diamonds precipitate from oxidized metasomatic fluids. The study of inclusions trapped in diamonds may provide precise information on composition, pressure, temperature and redox conditions. The aim of this study is to use the inclusions trapped in diamond as probes of the deep cycling of volatiles (C, H, halogens). Therefore, we investigate inclusions in diamonds with a systematic study of diamonds from collections. We selected 73 diamonds from three museums: National Museum of Natural History, School of Mines and Sorbonne University. The selected diamonds are studied with the help of a large range of in situ methods: RAMAN and FTIR spectrometry and X-Ray Diffraction. These analyses allow us to identify the nature of the different inclusions without damaging the gems. First results indicate silicate minerals inclusions as pyrope garnet, olivine and enstatite pyroxene. This assemblage is typical of peridotitic-type diamonds in the lithosphere.
DS201412-0812
2014
Boujibar, A.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
DS201702-0238
2017
Boujibar, A.Righter, K., Nickodem, K., Pando, K., Danielson, L., Boujibar, A., Righter, M., Lapen, T.J.Distribution of Sb, As, Ge and in between metal and silicate during acccretion and core formation in the Earth.Geochimica et Cosmochimica Acta, Vol. 198, pp. 1-16.MantleCore chemistry

Abstract: A large number of siderophile (iron-loving) elements are also volatile, thus offering constraints on the origin of volatile elements in differentiated bodies such as Earth, Moon, Mars and Vesta. Metal-silicate partitioning data for many of these elements is lacking, making their overall mantle concentrations in these bodies difficult to model and origin difficult to distinguish between core formation and volatile depletion. To address this gap in understanding, we have undertaken systematic studies of four volatile siderophile elements - Sb, As, Ge and In - at variable temperature and variable Si content of metal. Several series were carried out at 1 GPa, and between 1500 and 1900 °C, for both C saturated and C-free conditions. The results show that temperature causes a decrease in the metal/silicate partition coefficient for all four elements. In addition, activity coefficients for each element have been determined and show a very strong dependence on Si content of Fe alloy. Si dissolved in metal significantly decreases the metal/silicate partition coefficients, at both 1600 and 1800 °C. The combination of temperature and Si content of the metal causes reduction of the metal-silicate partition coefficient to values that are close to those required for an origin of mantle As, Sb, Ge, and In concentrations by metal-silicate equilibrium processes. Combining these new results with previous studies on As, Sb, Ge, and In, allowed derivation of predictive expressions for metal/silicate partition coefficients for these elements which can then be applied to Earth. The expressions are applied to two scenarios for continuous accretion of Earth; specifically for constant and increasing fO2 during accretion. The results indicate that mantle concentrations of As, Sb, Ge, and In can be explained by metal-silicate equilibrium during an accretion scenario. The modeling is not especially sensitive to either scenario, although all element concentrations are explained better by a model with variable fO2. The specific effect of Si is important and calculations that include only S and C (and no Si) cannot reproduce the mantle As, Sb, Ge, and In concentrations. The final core composition in the variable fO2 model is 10.2% Si, 2% S, and 1.1% C (or XSi = 0.18, XS = 0.03, and XC = 0.04. These results suggest that core formation (involving a Si, S, and C-bearing metallic liquid) and accretion were the most important processes establishing many of Earth’s mantle volatile elements (indigenous), while post-core formation addition or re-equilibration (exogenous) was of secondary or minor importance.
DS201707-1309
2017
Boujibar, A.Bouhifd, M.A., Clesi, V., Boujibar, A., Cartier, C., Hammouda, T., Boyet, M., Manthilake, G., Monteux, J., Andrault, D.Silicate melts during the Earth's core formation.Chemical Geology, Vol. 461, pp. 128-139.Mantlemelting

Abstract: Accretion from primordial material and its subsequent differentiation into a planet with core and mantle are fundamental problems in terrestrial and solar system. Many of the questions about the processes, although well developed as model scenarios over the last few decades, are still open and much debated. In the early Earth, during its formation and differentiation into rocky mantle and iron-rich core, it is likely that silicate melts played an important part in shaping the Earth's main reservoirs as we know them today. Here, we review several recent results in a deep magma ocean scenario that give tight constraints on the early evolution of our planet. These results include the behaviour of some siderophile elements (Ni and Fe), lithophile elements (Nb and Ta) and one volatile element (Helium) during Earth's core formation. We will also discuss the melting and crystallization of an early magma ocean, and the implications on the general feature of core-mantle separation and the depth of the magma ocean. The incorporation of Fe2 + and Fe3 + in bridgmanite during magma ocean crystallization is also discussed. All the examples presented here highlight the importance of the prevailing conditions during the earliest time of Earth's history in determining the composition and dynamic history of our planet.
DS201711-2499
2017
Boujibar, A.Andrault, D., Bolfan-Casanova, N., Bouhifd, M.A., Boujibar, A., Garbarino, G., Manthilake, G., Mezouar, M., Monteux, J., Parisiades, P., Pesce, G.Toward a coherent model for the melting behaviour of the deep Earth's mantle.Physics of the Earth and Planetary Interiors, Vol. 265, pp. 67-81.Mantlemelting

Abstract: Knowledge of melting properties is critical to predict the nature and the fate of melts produced in the deep mantle. Early in the Earth’s history, melting properties controlled the magma ocean crystallization, which potentially induced chemical segregation in distinct reservoirs. Today, partial melting most probably occurs in the lowermost mantle as well as at mid upper-mantle depths, which control important aspects of mantle dynamics, including some types of volcanism. Unfortunately, despite major experimental and theoretical efforts, major controversies remain about several aspects of mantle melting. For example, the liquidus of the mantle was reported (for peridotitic or chondritic-type composition) with a temperature difference of ?1000 K at high mantle depths. Also, the Fe partitioning coefficient (DFeBg/melt) between bridgmanite (Bg, the major lower mantle mineral) and a melt was reported between ?0.1 and ?0.5, for a mantle depth of ?2000 km. Until now, these uncertainties had prevented the construction of a coherent picture of the melting behavior of the deep mantle. In this article, we perform a critical review of previous works and develop a coherent, semi-quantitative, model. We first address the melting curve of Bg with the help of original experimental measurements, which yields a constraint on the volume change upon melting (?Vm). Secondly, we apply a basic thermodynamical approach to discuss the melting behavior of mineralogical assemblages made of fractions of Bg, CaSiO3-perovskite and (Mg,Fe)O-ferropericlase. Our analysis yields quantitative constraints on the SiO2-content in the pseudo-eutectic melt and the degree of partial melting (F) as a function of pressure, temperature and mantle composition; For examples, we find that F could be more than 40% at the solidus temperature, except if the presence of volatile elements induces incipient melting. We then discuss the melt buoyancy in a partial molten lower mantle as a function of pressure, F and DFeBg/melt. In the lower mantle, density inversions (i.e. sinking melts) appear to be restricted to low F values and highest mantle pressures. The coherent melting model has direct geophysical implications: (i) in the early Earth, the magma ocean crystallization could not occur for a core temperature higher than ?5400 K at the core-mantle boundary (CMB). This temperature corresponds to the melting of pure Bg at 135 GPa. For a mantle composition more realistic than pure Bg, the right CMB temperature for magma ocean crystallization could have been as low as ?4400 K. (ii) There are converging arguments for the formation of a relatively homogeneous mantle after magma ocean crystallization. In particular, we predict the bulk crystallization of a relatively large mantle fraction, when the temperature becomes lower than the pseudo-eutectic temperature. Some chemical segregation could still be possible as a result of some Bg segregation in the lowermost mantle during the first stage of the magma ocean crystallization, and due to a much later descent of very low F, Fe-enriched, melts toward the CMB. (iii) The descent of such melts could still take place today. There formation should to be related to incipient mantle melting due to the presence of volatile elements. Even though, these melts can only be denser than the mantle (at high mantle depths) if the controversial value of DFeBg/melt is indeed as low as suggested by some experimental studies. This type of melts could contribute to produce ultra-low seismic velocity anomalies in the lowermost mantle.
DS202102-0227
2021
Boukare, C-E.Vilella, K., Bodin, T., Boukare, C-E.,Deschamp, F., Badro, J., Ballmer, M.D. Li, Y.Constraints on the composition and temperature of LLSVPs from seismic properties of lower mantle minerals.Earth and Planetary Science Letters, Vol. 554, doi:10.1016/j.epsl.2020.116685Mantlegeophysics - seismic

Abstract: Here, we provide a reappraisal of potential LLSVPs compositions based on an improved mineralogical model including, for instance, the effects of alumina. We also systematically investigate the effects of six parameters: FeO and Al2O3 content, proportion of CaSiO3 and bridgmanite (so that the proportion of ferropericlase is implicitly investigated), Fe3+/?Fe and temperature contrast between far-field mantle and LLSVPs. From the 81 millions cases studied, only 79000 cases explain the seismic observations. Nevertheless, these successful cases involve a large range of parameters with, for instance, FeO content between 12--25~wt\% and Al2O3 content between 3--17~wt\%. We then apply a principal component analysis (PCA) to these cases and find two robust results: (i) the proportion of ferropericlase should be low (<6vol\%); (ii) the formation of Fe3+-bearing bridgmanite is much more favored than other iron-bearing phases. Following these results, we identify two end-member compositions, Bm-rich and CaPv-rich, and discuss their characteristics. Finally, we discuss different scenarios for the formation of LLSVPs and propose that investigating the mineral proportion produced by each scenario is the best way to evaluate their relevance. For instance, the solidification of a primitive magma ocean may produce FeO and Al2O3 content similar to those suggested by our analysis. However, the mineral proportion of such reservoirs is not well-constrained and may contain a larger proportion of ferropericlase than what is allowed by our results.
DS202108-1277
2021
Boukari, C.Derycke, A., Gautheron, C., Barbarand, J., Bourbon, P., Aertgeerts, G., Simon-Labric, T., Sarda, P., Pinna-Jamme, R., Boukari, C., Gaurine, F.French Guiana margin evolution: from Gondwana break-up to Atlantic Ocean.Terra Nova, Vol. 33, 4, pp. 415-422. pdfSouth America, French GuianaGuiana Shield

Abstract: Knowledge of the Guiana Shield evolution during the Gondwana break-up is key to a better understanding of craton dynamics and margin response to transtensional opening. To improve this knowledge, we investigated the dynamics and thermal evolution of French Guiana, using several low-temperature thermochronology methods applied to basement rocks, including apatite and zircon (U-Th)/He and apatite fission tracks. Inverse modelling of results allows us to reconstruct the Phanerozoic thermal history of French Guiana margin and to give a preview of the Guiana Shield evolution. Three main events are inferred: firstly, a long-term period of relative stability since ~1.2 Ga, with no strong evidence for any erosional or burial event (>5-7 km); secondly, a heating phase between ~210 and ~140 Ma consistent with the Central Atlantic Magmatic Province-related event. Finally, an exhumation phase between ~140 and ~90 Ma, triggered by the Equatorial Atlantic opening, brought samples close to the surface (<40°C).
DS1993-0775
1993
BoukhalfaKaminsky, F.V., Verzhak, V.V., Dauev, Yu.M., Buima, T., BoukhalfaThe North-African Diamondiferous provinceRussian Geology and Geophysics, Vol. 33, No. 7, pp. 91-95.AlgeriaBled-el-Mas, Alluvial placers
DS1993-0776
1993
BoukhalfaKaminsky, F.V., Verzhak, V.V., Dauev, Yu.M., Buima, T., BoukhalfaThe North African Diamondiferous provinceRussian Geology and Geophysics, Vol. 33, No. 7, pp. 82-90GlobalKimberlite
DS201412-0575
2014
Boulais, P.Midende, G., Boulais, P., Tack, L., Melcher, F., Gerdes,A., Dewaele, S., Demaiffe, D., Decree, S.Petrography, geochemistry and U Pb zircon age of the Matongo carbonatite Massif ( Burundi): implication for the Neoproterozoic geodynamic evolution of Central Africa.Journal of African Earth Sciences, Vol. 100, pp. 656-674.Africa, BurundiCarbonatite
DS1987-0680
1987
Boulange, B.Sigolo, J.B., Boulange, B., Muller, J.P., Schmitt, J.M.Distribution of rare earth elements in a lateritic bauxite profile on an alkaline rock-Passa QuatroMassive.POR.National Technical Information Service DE88704554, AO3 price, 12pBrazilAlkaline rocks
DS201512-1904
2015
Boulanger, J.Chen, W., Leblanc, S.G., White, H.P., Milkovic, B., O'Keefe, H., Croft, B., Gunn, A., Boulanger, J.Caribou relevant environmental changes around the Ekati diamond mine measured in 2015.43rd Annual Yellowknife Geoscience Forum Abstracts, abstract p. 24.Canada, Northwest TerritoriesDeposit - Ekati

Abstract: How would a large open pit mine on caribou range (e.g., the Ekati Diamond Mine in the Bathurst caribou’s summer range) have influenced caribou? A traditional knowledge study on the cumulative impacts on the Bathurst caribou herd qualitatively described how mining activities might have influenced the herd (Mackenzie et al. 2013): caribou migration routes deflected away from the mines probably due to seeing mining activities or hearing the noises; and skinny caribou or abnormal smells and materials in caribou meat, liver, or the hide linings probably related to changes in caribou forage and quality of water and air. In other words, the potential influences of mining operations on caribou were most likely through altering what caribou can see, hear, smell (e.g., dusts and fine particle matter < 2.5 ?m (PM2.5) in the air, and from acidity in the soil), and taste (e.g., dust on foliage, vegetation composition change). Boulanger et al. (2012) estimated the size of a zone of influence (ZOI) of the Ekati-Diavik mining complex in the Bathurst caribou summer range, using caribou presence dataset. They also explored the mechanisms of ZOI using the spatial distribution of the total suspended particles, which was simulated with an atmospheric transport and dispersion model (Rescan, 2006). While these studies have added to our understanding of the possible impacts of mining operations on caribou, knowledge gaps remain. One outstanding gap is the lack of direct measurements about the caribou relevant environmental changes caused by mining operations. For example, exactly from how far away can caribou clearly see the vehicles driving on a mining road, or the buildings and the elevated waste piles in a camp? From how far away might caribou hear the noise caused by mining operations? To what spatial extent had the dusts and PM2.5 from mining operations influenced the tundra ecosystems? And how the dusts and PM2.5 from mining operations might have influenced caribou forage quality? Potentially these questions can be answered by in-situ measurements and satellite remote sensing. For example, studies have showed that it is possible to remotely sense PM2.5 distribution using twice-daily MODIS data at a spatial resolution of 1 km (Lyapustin et al., 2011; Chudnovsky et al., 2013; Hu et al., 2014). The objective of this study is thus to quantitatively measure these changes around the Ekati Diamond Mine, by means of in-situ surveys and satellite remote sensing. We conducted field surveys at more than 100 sites around the Ekati Diamond Mine during August 14-23, 2015, a collaborative effort of the NWT CIMP project entitled “Satellite Monitoring for Assessing Resource Development’s Impact on Bathurst Caribou (SMART)”, and the Dominion Diamond Ekati Corporation. In this presentation, we will report preliminary results and lessons learned from our first year’s study.
DS201709-1985
2017
Boulanger, M.France, L., Boulanger, M., Mollex, G., Devidal, J-L. .Oldoinyo Lengai natrocarbonatite derives from calciocarbonatite.Goldschmidt Conference, abstract 1p.Africa, Tanzaniadeposit, Oldoinyo

Abstract: Carbonatites are rare magmas containing almost no silica; the corresponding crystallized rocks represent the main rare earth elements (REE) deposits in production. Oldoinyo Lengai (Tanzania) is the only active carbonatite volcano on Earth, and may be used as a natural laboratory to identify the parameters responsible for the genesis of the >500 reported fossil occurrences of carbonatite magmas. Nevertheless the carbonatites emitted at Oldoinyo Lengai are unique as alkalirich (natrocarbonatites), and their origin may not be representative of the fossil carbonatites (calcio-, ferro-, magnesio-carbonatites). Here we use three-phases melt inclusions trapped in clinopyroxenes and nephelines from cognate cumulates – that sample the active magma chamber of Oldoinyo Lengai – emitted during the 2007-08 sub-plinian explosive eruption to track the carbonatite presence within the plumbing system, and to eventually quantify its composition at depth. We show that although natrocarbonatites are emitted at Oldoinyo Lengai summit, more classical calciocarbonatites are present at magma chamber depth, consistent with rare natrocarbonatites being derived from more classical calciocarbonatites by further magma differentiation. Those unique cognate samples allows us to provide the first direct measurements of partition coefficients for major and trace elements of natural coexisting in equilibrium carbonatite and silicate melts. Partition coefficients suggests that natrocarbonatites derive from calciocarbonatites by fractionating Ca-rich, and Na-poor phases. The Oldoinyo Lengai can therefore be used as a perfect analogue of fossil igneous systems that are now exhumed, commonly lacking any relation with the initial geodynamic setting, and form REE mineral deposits.
DS201909-2020
2019
Boulanger, M.Baudouin, C., France, L., Boulanger, M., Dalou, C., Devidal, J-L.New constraints on trace element partitioning between minerals and alkaline melts.Goldschmidt2019, 1p. AbstractGlobalalkaline rocks
DS201909-2063
2019
Boulanger, M.Mollex, G., France, L., Boulanger, M., Devidal, J-L.Oldoinyo Lengai natrocarbonatites derive from classical calciocarbonatites: a melt inclusion approach.Goldschmidt2019, 1p. AbstractAfrica, Tanzaniadeposit - Oldoinyo Lengai

Abstract: Carbonatites are rare magmas containing almost no silica; their igneous counterparts represent the main rare earth element deposits inoperation. No consensus exists on their origin, genesis and evolution. Oldoinyo Lengai (Tanzania) is the only active carbonatite volcano, but the alkali-rich natrocarbonatites it erupts are unique among the >500 reported fossil carbonatite occurrences. Here, we use threephase melt inclusions hosted in minerals from cognate cumulates (clinopyroxene, nepheline, Ti-garnet, interstitial melt)— which sampled the active Oldoinyo Lengai magma chamber during the 2007-08 sub-Plinian explosive eruption—to track the carbonatite presence within the plumbing system, and to eventually quantify its composition at depth. We show that although natrocarbonatites are emitted at the Oldoinyo Lengai summit, more classical calciocarbonatites are present at magma chamber depth (~3.5 kbar, 1050 to 900°C), which is consistent with the model of rare natrocarbonatites deriving from calciocarbonatites by further magma differentiation. We also show that those calciocarbonatites are not isolated but rather conjugated with alkali-rich silica melt suggesting a joint evolution. We eventually present the first direct measurements of major and trace element partition coefficients between natural coexisting carbonate and silicate melts. Partitioning behaviour and recent experiments support our conclusion that natrocarbonatites derive from calciocarbonatites by fractionating Ca-rich, Na-poor phases. As natrocarbonatites are highly unstable at surface conditions, they were likely erupted but not preserved in association with fossil calciocarbonatites worldwide. Oldoinyo Lengai can then be considered as representative of other carbonatite systems, and provide us with the unique opportunity to observe the plumbing system architecture, and to constrain the protracted differentiation path of a carbonatite system.
DS202006-0911
2020
Boulanger, M.Baudouin, C., France, L., Boulanger, M., Dalou, C., Devidal, J-L.Trace element partitioning between clinopyroxene and alkaline magmas: parametrization and role of M1 site on HREE enrichment in clinopyroxenes.Contributions to Mineralogy and Petrology, Vol. 175, 15p. PdfAfrica, Tanzaniadeposit - Oldoinyo Lengai

Abstract: Trace element partitioning between minerals and liquids provides crucial constraints on igneous processes. We quantified trace element concentrations in clinopyroxene (Cpx) phenocrysts and their phonolite melt inclusions from the 2007-08 eruption of Oldoinyo Lengai (Tanzania), and report Cpx-melt partition coefficients (D) and corresponding partitioning equations for rare earth elements (REE) and high field strength elements (HFSE) in alkaline magmas. Heavy REE (HREE: Er, Tm, Yb, Lu) are enriched relative to middle REE in alkaline Cpx and display a specific partitioning behavior that is characteristic of alkaline systems. HFSE (Ti, Zr, Hf) and HREE have similar D values (DHf?=?0.25; DLu?=?0.4) that are significantly higher than MREE (DSm?=?0.06). High DHREE/DMREE are strongly correlated with the high values of DZr and DHf relative to the low DMREE values. In this study, REE partitioning between phonolite melt and Cpx is not consistent with standard models assuming incorporation of all REE in the Cpx M2 site, but rather highlights HREE substitution in both the M1 and M2 sites. Here we highlight the preferential incorporation of HREE in the VI-coordinated M1 site, whereas light REE and MREE remain mostly distributed in the VIII-coordinated M2 site. REE partitioning is strongly dependent on Cpx chemistry: the ideal ionic radius and HREE incorporation in the M1 site increase with increasing Fe3+ content and decrease with increasing Mg2+ and AlVI content. In our study, we focus on alkaline evolved magmas, and update existing models to obtain adequate DHREE for alkaline evolved melts. We provide equations to quantify REE and HFSE partitioning, and HREE enrichment in Cpx that are based on Cpx major element composition and temperature. We propose a new model based on the lattice strain approach that predicts HREE partitioning between Cpx and alkaline magmas. The knowledge of the melt composition or of the trace element contents is not required to obtain DREE from the new model. An improved parameterization of HFSE partitioning between Cpx and phonolite and trachy-phonolite melts is also provided herein. We discuss the potential implications of the new data on our understanding of REE deposits that are commonly associated with igneous alkaline complexes.
DS201112-0099
2011
Boulard, E.Boulard, E., Menguyy, Auzende, Benzerara, Bureau, Antonangeli, Corgne, Morard, Siebert, Perrilat, GuyotExperimental investigation of the stability of Fe rich carbonates in the lower mantle.Goldschmidt Conference 2011, abstract p.561.MantleCarbon reduced.... diamonds
DS201212-0083
2012
Boulard, E.Boulard, E., Mao, W.Mg, Fe rich carbonates stability at lower mantle conditions.Goldschmidt Conference 2012, abstract 1p.MantlePerovskite
DS201904-0719
2019
Boulard, E.Boulard, E., Harmand, M., Guyot, F., Lelong, G., Morard, D., Cabaret, D., Boccato, S., Rosa, A.D., Briggs, R., Pascarelli, S., Fiquet, G.Ferrous iron under oxygen rich conditions in the deep mantle.Geophysical Research Letters, Vol. 46, 3, pp. 1348-1356.MantleUHP

Abstract: Iron oxides are important end?members of the complex materials that constitute the Earth's interior. Among them, FeO and Fe2O3 have long been considered as the main end?members of the ferrous (Fe2+) and ferric (Fe3+) states of iron, respectively. All geochemical models assume that high oxygen concentrations are systematically associated to the formation of ferric iron in minerals. The recent discovery of O22? peroxide ions in a phase of chemical formula FeO2Hx stable under high?pressure and high?temperature conditions challenges this general concept. However, up to now, the valences of iron and oxygen in FeO2Hx have only been indirectly inferred from a structural analogy with pyrite FeS2. Here we compressed goethite (FeOOH), an Fe3+?bearing mineral, at lower mantle pressure and temperature conditions by using laser?heated diamond?anvil cells, and we probed the iron oxidation state upon transformation of FeOOH in the pressure-temperature stability field of FeO2Hx using in situ X?ray absorption spectroscopy. The data demonstrate that upon this transformation iron has transformed into ferrous Fe2+. Such reduced iron despite high oxygen concentrations suggests that our current views of oxidized and reduced species in the lower mantle of the Earth should be reconsidered.
DS1998-0145
1998
Boulay, R.A.Boulay, R.A.Metallic and industrial mineral assessment report on the exploration work in the Chinchaga area.Alberta Geological Survey, MIN 19980016AlbertaExploration - assessment, Marum Resources Inc.
DS201112-0100
2011
Boulila, S.Boulila, S., Galbrun, B., Miller, K.G., Pekar, S.F., Browning, J.V., Laskar, J., Wright, J.D.On the origin of Cenozoic and Mesozoic 'third order' eustatic sequences.Earth Science Reviews, Vol. 109, 3-4, pp. 94-112.GlobalGeomorphology - sea levels
DS201605-0897
2016
Boulliard, J.C.Schoor, M., Boulliard, J.C., Gaillou, E., Duparc, O.H., Esteve, I., Baptiste, B., Rondeau, B., Fritsch, E.Plastic deformation in natural diamonds: rose channels associated to chemical twinning.Diamond and Related Materials, in press available 14p.TechnologyDiamond morphlogy
DS1970-0793
1973
Boullier, A.Nixon, P.H., Boyd, F.R., Boullier, A.The Evidence of Kimberlite and its Inclusions on the Constitution of the Outer Part of the Earth.Maseru: Lesotho Nat. Dev. Corp. Lesotho Kimberlites Editor N, PP. 312-318.Lesotho, South AfricaGenesis
DS1970-0635
1973
Boullier, A.M.Boullier, A.M., Nicolas, A.Texture and Fabric of Peridotite Nodules from Kimberlite Atmothae, Thaba Putsoa and Kimberley.Maseru: Lesotho Nat. Dev. Corp. Lesotho Kimberlites Editor N, PP. 57-66.Lesotho,South AfricaPetrography, Xenoliths
DS1970-0881
1974
Boullier, A.M.Boullier, A.M.Structure des Enclaves Ultrabasiques des Kimberlites D'afrique du Sud; Positions sur la Geotherme Cretacie.Reun. Annual Sci. Terre., No. 2, P. 78.South AfricaTectonics, Cretaceous
DS1975-0037
1975
Boullier, A.M.Boullier, A.M., Nicholas, A.Classification and Textures and Fabrics of Peridotite Xenoliths from South African Kimberlites.Physics and Chemistry of the Earth, Vol. 9, PP. 467-476.South AfricaPetrography
DS1975-0468
1977
Boullier, A.M.Boullier, A.M.Structure of Peridotite Xenoliths in Southern African Kimberlites: Implications for Upper Mantle Composition.Soc. Min. France (paris) Bulletin., Vol. 100, No. 3-4, PP. 214-220.South AfricaPetrography
DS1998-0232
1998
Boullier, A.M.Chalot-Prat, F., Boullier, A.M.Genetic relationships between lithospheric mantle, alkaline and calc-alkaline basic volcanoes ....Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 300-1.Romania, eastern CarpathiansGeochemistry - neodymium-Sr isotope, geochronology, Xenoliths
DS201012-0012
2010
Boullier, A-M.Arndt, N.T., Guitreau, M., Boullier, A-M., Le Roex, A., Tommasi, A.M., Cordier, P., Sobolev, A.Olivine, and the origin of kimberlite.Journal of Petrology, Vol. 51, 3, pp. 573-602.TechnologyKimberlite genesis
DS201412-0145
2014
Boullier, A-M.Cordier, C., Sauzert, L., Arndt, N., Boullier, A-M.Olivine in kimberlites: metasomatism of the deep lithospheric mantle.Economic Geology Research Institute 2014, No. 11390 1p. abstractMantleMetasomatism
DS201512-1905
2015
Boullier, A-M.Cordier, C., Sauzeat, L., Arndt, N.T., Boullier, A-M., Batanova, V., Barou, F.Metasomatism of the lithospheric mantle immediately precedes kimberlite eruption: new evidence from olivine composition and microstructures.Journal of Petrology, Vol. 56, 9, pp. 1775-1796.TechnologyOlivine, metasomatism

Abstract: Most kimberlites contain abundant dunitic nodules. These are centimetre-sized, rounded and multi-grained assemblages of xenocrystic olivine with a wide range of compositions (Fo83 to Fo94). The absence of orthopyroxene and other mantle minerals and the range of olivine compositions have been attributed to reaction between mantle peridotite and (proto)kimberlitic fluid or melt, but the timing of the reaction is a subject of debate. In a kimberlite from the Kangamiut region of Greenland, nodule cores are surrounded by fine-grained outer margins with near-constant Fo contents (~Fo88) but highly variable minor element contents (e.g. 500-2500 ppm Ni). These margins crystallized from the kimberlite melt and we show that their compositions can be explained by crystallization of olivine alone, if a high partition coefficient for Ni between melt and olivine (DNi > 20) is assumed. Orthopyroxene assimilation is not required, removing the constraint that its dissolution occurred during ascent of the kimberlite magma. Within some nodules, in addition to the usual core-to-margin gradients, we observe asymmetric compositional changes (variable Fo but near-constant minor element contents) across mobile grain boundaries. These changes document fluid percolation at the grain scale that occurred during dynamic recrystallization in the deforming lithospheric mantle. We note that chemical gradients associated with mobile grain boundaries are observed in olivines that cover the entire compositional range of the nodules, and propose that fluid-assisted dynamic recrystallization took place in dunite that was already compositionally heterogeneous. Reaction between peridotite and protokimberlitic melt or fluid and dissolution of orthopyroxene thus occurred within the lithospheric mantle, immediately (a few days) prior to the ascent of the kimberlite melt and the entrainment of the dunite nodules. We propose that the grain boundary zones probably mimic, at a fine scale, the fluid-peridotite interaction that caused, at a larger scale, orthopyroxene dissolution and formation of compositionally diverse olivine in kimberlites.
DS201601-0011
2015
Boullier, A-M.Cordier, C., Sauzeat, L., Arndt, N.T., Boullier, A-M., Batanova, V., Barou, F.Metasomatism of the lithospheric mantle immediately precedes kimberlite eruption: new evidence from olivine composition and mircostructures.Journal of Petrology, Vol. 56, 9, pp. 1775-1796.Europe, GreenlandDeposit - Kangamiut field

Abstract: Most kimberlites contain abundant dunitic nodules. These are centimetre-sized, rounded and multi-grained assemblages of xenocrystic olivine with a wide range of compositions (Fo83 to Fo94). The absence of orthopyroxene and other mantle minerals and the range of olivine compositions have been attributed to reaction between mantle peridotite and (proto)kimberlitic fluid or melt, but the timing of the reaction is a subject of debate. In a kimberlite from the Kangamiut region of Greenland, nodule cores are surrounded by fine-grained outer margins with near-constant Fo contents (~Fo88) but highly variable minor element contents (e.g. 500-2500 ppm Ni). These margins crystallized from the kimberlite melt and we show that their compositions can be explained by crystallization of olivine alone, if a high partition coefficient for Ni between melt and olivine (DNi > 20) is assumed. Orthopyroxene assimilation is not required, removing the constraint that its dissolution occurred during ascent of the kimberlite magma. Within some nodules, in addition to the usual core-to-margin gradients, we observe asymmetric compositional changes (variable Fo but near-constant minor element contents) across mobile grain boundaries. These changes document fluid percolation at the grain scale that occurred during dynamic recrystallization in the deforming lithospheric mantle. We note that chemical gradients associated with mobile grain boundaries are observed in olivines that cover the entire compositional range of the nodules, and propose that fluid-assisted dynamic recrystallization took place in dunite that was already compositionally heterogeneous. Reaction between peridotite and protokimberlitic melt or fluid and dissolution of orthopyroxene thus occurred within the lithospheric mantle, immediately (a few days) prior to the ascent of the kimberlite melt and the entrainment of the dunite nodules. We propose that the grain boundary zones probably mimic, at a fine scale, the fluid-peridotite interaction that caused, at a larger scale, orthopyroxene dissolution and formation of compositionally diverse olivine in kimberlites.
DS201706-1068
2017
Boullier, A-M.Cordier, C., Sauzeat, L., Arndt, N.T., Boullier, A-M., Batanova, V., Barou, F.Quantitative modelling of the apparent decoupling of Mg# and Ni in kimberlitic olivine margins: comment on Cordier et al. by A.Moore.Journal of Petrology, Vol. 58, pp. 1-3.Europe, Greenlanddeposit - Kangamiut

Abstract: Moore proposes in his Comment (Moore, 2017) that marginal zones in olivine grains in kimberlites (Fig. 1a) are produced by crystallization from kimberlite melt. He suggests that the chemical zones observed in these marginal zones (inner transition zones and outer margins, illustrated in his fig. 1) result from abrupt changes in distribution coefficients during crystallization. He proposes that the transition zones, characterized by variable Fo at constant and high Ni contents, are produced by crystallization with high KdFe-Mg (= 0•45) and low DNi (= 4) whereas the margins, characterized by a sharp drop in Ni content at nearly constant Fo (Fig. 1b), are produced by crystallization with higher DNi owing to a sudden change in physical conditions of crystallization (P,…
DS201212-0140
2012
Boulon, J.Dalou, C., Koga, K.T., Shimizu, N., Boulon, J., Devidal, J-L.Experimental determination of F and Cl partitioning between lherzolite and basaltic melt.Contributions to Mineralogy and Petrology, Vol. 163, 4,TechnologyLherzolite petrology
DS1975-0699
1978
Boulton, G.S.Boulton, G.S.Boulder shapes and grain size distributions of debris as indicators of transport paths through a glacier and till genesis.Sedimentology, Vol. 78, pp. 773-99.GlobalGeomorphology - Tills, Review
DS1985-0078
1985
Boulton, G.S.Boulton, G.S., Smith, G.D., Jones, A.S., Newsome, J.Glacial Geology and Glaciology of the Last Mid Latitude Icesheets.Journal of the Geological Society of London., Vol. 142, No. 3, MAY PP. 447-474.United States, CanadaGlacial Dispersion
DS1990-0226
1990
Boulton, G.S.Boulton, G.S., Clark, C.D.The Laurentide ice sheet through the last Glacial cycle - the topology of drift lineations as a key to dynamic behaviour of former ice sheetsTransactions Royal Society. Edinburgh Earth Science, Vol. 81, pp. 327-348Canada, United States, EuropeGeomorphology, Laurentide ice sheet
DS1990-0227
1990
Boulton, G.S.Boulton, G.S., Clark, C.D.A highly mobile Laurentide ice sheet revealed by satellite images of glacial lineationsNature, Vol. 346, No. 6287 August 30, pp. 813-817OntarioGeomorphology, remote sensing, Laurentide
DS201312-0090
2013
Boulvais, P.Boulvais, P., Decree, S., Cobert, C., Midende, G., Tack, L., Gardien, V., Demaiffe, D.C and O isotope compositios of the Matongo carbonatite ( Burundi): new insights into alteration and REE mineralization processes.Goldschmidt 2013, AbstractAfrica, BurundiCarbonatite
DS201412-0553
2014
Boulvais, P.Martin, R.F., Randrianandraisana, A., Boulvais, P.Ampandrandava and similar phlogopite deposits in southern Madagascar: derivation from a silicocarbonatitic melt of crustal origin.Journal of African Earth Sciences, Vol. 94, pp. 111-118.Africa, MadagascarCarbonatite
DS201502-0078
2014
Boulvais, P.Midende, G., Boulvais, P., Tack, L., Melcher, F., Gerdes, A., Dewaele, S., Demaiffe, D., Decree, S.Petrography, geochemistry and U-Pb zircon age of the Matongo carbonatite Massif ( Burundi): implication for the Neoproterozoic geodynamic evolution of Central Africa.Journal of African Earth Sciences, Vol. 100, pp. 656-674.Africa, BurundiCarbonatite
DS201511-1830
2015
Boulvais, P.Decree, S., Boulvais, P., Tack, L., Andre, L., Baele, J-M.Fluorapatite in carbonatite-related phosphate deposits: the case of the Matongo carbonatite. ( Burundi)Mineralium Deposita, in press available 14p.Africa, BurundiCarbonatite

Abstract: The Matongo carbonatite intrusive body in the Neoproterozoic Upper Ruvubu alkaline plutonic complex (URAPC) in Burundi is overlain by an economic phosphate ore deposit that is present as breccia lenses. The ore exhibits evidence of supergene enrichment but also preserves textures related to the concentration of fluorapatite in the carbonatitic system. Magmatic fluorapatite is abundant in the ore and commonly occurs as millimeter-sized aggregates. It is enriched in light rare earth elements (LREE), which is especially apparent in the final generation of magmatic fluorapatite (up to 1.32 wt% LREE2O3). After an episode of metasomatism (fenitization), which led to the formation of K-feldspar and albite, the fluorapatite-rich rocks were partly brecciated. Oxygen and carbon isotope compositions obtained on the calcite forming the breccia matrix (?18O?=?22.1?- and ?13C?=??1.5?‰) are consistent with the involvement of a fluid resulting from the mixing of magmatic-derived fluids with a metamorphic fluid originating from the country rocks. In a subsequent postmagmatic event, the carbonates hosting fluorapatite were dissolved, leading to intense brecciation of the fluorapatite-rich rocks. Secondary carbonate-fluorapatite (less enriched in LREE with 0.07-0.24 wt% LREE2O3 but locally associated with monazite) and coeval siderite constitute the matrix of these breccias. Siderite has ?18O values between 25.4 and 27.7?- and very low ?13C values (from ?12.4 to ?9.2?, which are consistent with the contribution of organic-derived low ?13C carbon from groundwater. These signatures emphasize supergene alteration. Finally, the remaining voids were filled with a LREE-poor fibrous fluorapatite (0.01 wt% LREE2O3), forming hardened phosphorite, still under supergene conditions. Pyrochlore and vanadiferous magnetite are other minerals accumulated in the eluvial horizons. As a consequence of the supergene processes and fluorapatite accumulation, the phosphate ore, which contains 0.72 to 38.01 wt% P2O5, is also enriched in LREE (LaN/YbN from 47.1 to 83.5; ?REE between 165 and 5486 ppm), Nb (up to 656 ppm), and V (up to 1232 ppm). In the case of phosphate exploitation at Matongo, REE could prove to have a subeconomic potential to be exploited as by-products of phosphates.
DS201601-0013
2015
Boulvais, P.Decree, S., Boulvais, P., Tack, L., Andre, L., Baele, J-M.Fluorapatite in carbonatite related phosphate deposits: the case for the Matongo carbonatite ( Burundi).Mineralogy and Petrology, in press available, 17p.Africa, BurundiCarbonatite

Abstract: The Matongo carbonatite intrusive body in the Neoproterozoic Upper Ruvubu alkaline plutonic complex (URAPC) in Burundi is overlain by an economic phosphate ore deposit that is present as breccia lenses. The ore exhibits evidence of supergene enrichment but also preserves textures related to the concentration of fluorapatite in the carbonatitic system. Magmatic fluorapatite is abundant in the ore and commonly occurs as millimeter-sized aggregates. It is enriched in light rare earth elements (LREE), which is especially apparent in the final generation of magmatic fluorapatite (up to 1.32 wt% LREE2O3). After an episode of metasomatism (fenitization), which led to the formation of K-feldspar and albite, the fluorapatite-rich rocks were partly brecciated. Oxygen and carbon isotope compositions obtained on the calcite forming the breccia matrix (?18O?=?22.1?‰ and ?13C?=??1.5?‰) are consistent with the involvement of a fluid resulting from the mixing of magmatic-derived fluids with a metamorphic fluid originating from the country rocks. In a subsequent postmagmatic event, the carbonates hosting fluorapatite were dissolved, leading to intense brecciation of the fluorapatite-rich rocks. Secondary carbonate-fluorapatite (less enriched in LREE with 0.07-0.24 wt% LREE2O3 but locally associated with monazite) and coeval siderite constitute the matrix of these breccias. Siderite has ?18O values between 25.4 and 27.7?‰ and very low ?13C values (from ?12.4 to ?9.2?‰), which are consistent with the contribution of organic-derived low ?13C carbon from groundwater. These signatures emphasize supergene alteration. Finally, the remaining voids were filled with a LREE-poor fibrous fluorapatite (0.01 wt% LREE2O3), forming hardened phosphorite, still under supergene conditions. Pyrochlore and vanadiferous magnetite are other minerals accumulated in the eluvial horizons. As a consequence of the supergene processes and fluorapatite accumulation, the phosphate ore, which contains 0.72 to 38.01 wt% P2O5, is also enriched in LREE (LaN/YbN from 47.1 to 83.5; ?REE between 165 and 5486 ppm), Nb (up to 656 ppm), and V (up to 1232 ppm). In the case of phosphate exploitation at Matongo, REE could prove to have a subeconomic potential to be exploited as by-products of phosphates.
DS201906-1277
2019
Boulvais, P.Boulvais, P., Ntiharirizwa, S., Branquet, Y., Poujol, M., Moreli, C., Ntungwanayo, J., Midende, G.Geology and U-Th dating of the Gakara REE deposit.GAC/MAC annual Meeting, 1p. Abstract p. 64.Africa, BurundiREE

Abstract: The Gakara Rare Earth Elements (REE) deposit is one of the world’s highest grade REE deposits, likely linked to a carbonatitic magmatic-hydrothermal activity. It is located near Lake Tanganyika in Burundi, along the western branch of the East African Rift. Field observations suggest that the mineralized veins formed in the upper crust. Previous structures inherited from the Kibaran orogeny may have been reused during the mineralizing event. The paragenetic sequence and the geochronological data show that the Gakara mineralization occurred in successive stages in a continuous hydrothermal history. The primary mineralization in bastnaesite was followed by an alteration stage into monazite. The U-Th-Pb ages obtained on bastnaesite (602 ± 7 Ma) and on monazite (589 ± 8 Ma) belong to the Pan-African cycle. The emplacement of the Gakara REE mineralization most likely took place during a pre-collisional event in the Pan-African belt, probably in an extensional context.
DS200412-0518
2004
Bouman, C.Elliott, T., Jeffcoate, A., Bouman, C.The terrestrial Li isotope cycle: light weight constraints on mantle convection.Earth and Planetary Science Letters, Vol. 220, 3-4, pp. 231-245.MantleGeochronology
DS201901-0002
2018
Bouman, M.Anthonis, A., Chapman, J., Smans, S., Bouman, M., De Corte, K.Fluorescence in diamond: new insights.Gems & Gemology, Sixth International Gemological Symposium Vol. 54, 3, 1p. Abstract p. 265-6.GlobalFluoresence

Abstract: The effect of fluorescence on the appearance of diamonds has been a subject of debate for many years (Moses et al., 1997). In the trade, fluorescence is generally perceived as an undesirable characteristic. Nearly 80% of diamonds graded at HRD Antwerp receive a “nil” fluorescence grade, while the remainder are graded as “slight,” “medium,” and “strong,” their value decreasing with level of fluorescence. To understand how fluorescence might change diamond appearance, a selection of 160 round brilliant-cut diamonds were investigated in detail. This study focused on the effect of thetic samples, it is possible that some of the observed phosphorescence does not involve boron impurities. In this paper we report on the results of combined fluorescence, phosphorescence, thermoluminescence, and quantitative charge transfer investigations undertaken on both HPHT and CVD synthetic diamond, with the objective of identifying which defects are involved in the fluorescence and phosphorescence processes.
DS201904-0720
2019
Bouman, M.Bouman, M., Anthonis, A., Chapman, J., Smans, S., De Corte, K.The effect of blue fluorescence on the colour appearance of round brilliant cut diamonds.Journal of Gemology, Vol. 36, 4, pp. 298-315.Globaldiamond fluoresence
DS202111-1768
2021
Boumedhdi, M.A.Gong, Z., Evans, D.A.D., Youbi, N., Lahna, A.A., Sodelund, U., Malek, M.A., Wen, B., Jing, X., Ding, J., Boumedhdi, M.A., Ernst, R.E.Reorienting the West African craton in Paleoproterozoic-Msoproterozoic supercontinent Nuna.Geology, Vol. 49, 10, pp. 1171-1176. pdfAfrica, west AfricaNuna

Abstract: The location of the West African craton (WAC) has been poorly constrained in the Paleoproterozoic-Mesoproterozoic supercontinent Nuna (also known as Columbia). Previous Nuna reconstruction models suggested that the WAC was connected to Amazonia in a way similar to their relative position in Gondwana. By an integrated paleomagnetic and geochronological study of the Proterozoic mafic dikes in the Anti-Atlas Belt, Morocco, we provide two reliable paleomagnetic poles to test this connection. Incorporating our new poles with quality-filtered poles from the neighboring cratons of the WAC, we propose an inverted WAC-Amazonia connection, with the northern WAC attached to northeastern Amazonia, as well as a refined configuration of Nuna. Global large igneous province records also conform to our new reconstruction. The inverted WAC-Amazonia connection suggests a substantial change in their relative orientation from Nuna to Gondwana, providing an additional example of large-magnitude cumulative azimuthal rotations between adjacent continental blocks over supercontinental cycles.
DS201612-2350
2016
Boumehdi, M.A.Youbi, N., Ernst, R.E., Soderlund, U., Boumehdi, M.A., Bensalah, M.K., Aarab, E.M.Morocco, North Africa: a dyke swarm bonanza.Acta Geologica Sinica, Vol. 90, July abstract p. 15.Africa, MoroccoDykes
DS201805-0952
2017
Boumehdi, M.A.Ikenne, M., Lahna, A.A., Soderlund, U., Tassinar, C.C.G., Ernst, R.E., Pin, Ch., Youbi, N., El Aouli, EH., Hafid, A., Admou, H., Mata, J., Bouougri, EH., Boumehdi, M.A.New Mesoproterozoic age constraints for the Taghdout Group, Anti-Atlas ( Morocco): toward a new lithostratigra[hic framework for the Precambrian in the NW margin of the West African Craton.The First West African Craton and Margins International Workshop WACMA, Held Apr. 24-29. 1p. AbstractAfrica, Moroccogeochronology
DS202004-0500
2020
Boumehdi, M.A.Ba, M.H., Ibough, H., Lo, K., Youbi, N., Jaffal, M., Ernst, R.E., Niang, A.J., Dia, I., Abdeina, E.H., Bensalah, M.K., Boumehdi, M.A., Soderlund, U.Spatial and temporal distribution patterns of Precambrian mafic dyke swarms in northern Mauritania ( West African Craton): analysis and results fro remote sensing interpretation, geographical information systems ( GIS), Google Earth TM images, and regionaArabian Journal of Geosciences, Vol. 13, , 209 orchid.org/ 0000-002-3287-9537Africa, Mauritaniacraton

Abstract: We used remote sensing, geographical information systems, Google Earth™ images, and regional geology in order to (i) improve the mapping of linear structures and understand the chronology of different mafic dyke swarms in the Ahmeyim area that belongs to the Archean Tasiast-Tijirit Terrane of the Reguibat Shield, West African craton, NW Mauritania. The spatial and temporal distributions with the trends of the dyke swarms provide important information about geodynamics. The analysis of the mafic dyke swarms map and statistical data allow us to distinguish four mafic dyke swarm sets: a major swarm trending NE-SW to NNE-SSW (80%) and three minor swarms trending EW to ENE-WSW (9.33%), NW-SE to WNW-ESE (9.06%), and NS (1.3%). The major swarms extend over 35 km while the minor swarms do not exceed 13 km. The Google Earth™ images reveal relative ages through crossover relationships. The major NE-SW to NNE-SSW and the minor NS swarms are the oldest generations emplaced in the Ahemyim area. The NW-SE-oriented swarm dykes which are cutting the two former swarms are emplaced later. The minor E-W to WSW-ENE swarms are probably the youngest. A precise U-Pb baddeleyite age of 2733?±?2 Ma has been obtained for the NNE-SSW Ahmeyim Great Dyke. This dyke is approximately 1500 m wide in some zone and extends for more than 150 km. The distinct mafic dyke swarms being identified in this study can potentially be linked with coeval magmatic events on other cratons around the globe to identify reconstructed LIPs and constrain continental reconstructions.
DS1997-0359
1997
Bounama, C.Franck, S., Bounama, C.Continental growth and volatile exchange during earth's evolutionPhysics of the Earth and Plan. Interiors, Vol. 100, pp. 189-196.MantleGeothermometry, Heat transport, silicates
DS1994-0540
1994
Boundy, T.M.Fountain, D.M., Boundy, T.M., et al.Eclogite facies shear zones - deep crustal reflectors?Tectonophysics, Vol. 232, pp. 411-424.NorwayTectonics -shear zones, Eclogites
DS1996-0158
1996
Boundy, T.M.Boundy, T.M., Essene, E.J., Hall, C., Austrheim, HallidayRapid exhumation of lower crust during continent-continent collision and Late extension...Geological Society of America (GSA) Bulletin., Vol. 108, No. 11, Nov. pp. 1425-37.NorwayCaledonian Orogeny, Geochronology
DS1997-0118
1997
Boundy, T.M.Boundy, T.M., Mezger, K., Essene, E.J.Temporal and tectonic evolution of the granulite-eclogite association From the Bergen Arcs.Lithos, Vol. 39, No. 3-4, Feb. pp. 159-178.NorwayTectonics, Eclogite
DS2003-0141
2003
Bouougri, E.H.Bouougri, E.H.The Moroccan Anti-Atlas: the West African craton passive margin with limitedPrecambrian Research, Vol. 120, 1-2, pp.179-183; 185-189.Morocco, West AfricaTectonics
DS200412-0188
2003
Bouougri, E.H.Bouougri, E.H.The Moroccan Anti-Atlas: the West African craton passive margin with limited Pan-African activity. Implications for the northernPrecambrian Research, Vol. 120, 1-2, pp.179-183; 185-189.Africa, MoroccoTectonics
DS200512-0105
2004
Bouougri, E.H.Bouougri, E.H., Saquaque, A.Lithostratigraphic framework and correlation of the Neoproterozoic northern West African Craton passive margin sequence Siroua Zenaga Bouazzer Elgraara InliersJournal of African Earth Sciences, Vol. 39, 3-5, pp. 227-238.Africa, MoroccoStratigraphy, integrated approach
DS201805-0952
2017
Bouougri, EH.Ikenne, M., Lahna, A.A., Soderlund, U., Tassinar, C.C.G., Ernst, R.E., Pin, Ch., Youbi, N., El Aouli, EH., Hafid, A., Admou, H., Mata, J., Bouougri, EH., Boumehdi, M.A.New Mesoproterozoic age constraints for the Taghdout Group, Anti-Atlas ( Morocco): toward a new lithostratigra[hic framework for the Precambrian in the NW margin of the West African Craton.The First West African Craton and Margins International Workshop WACMA, Held Apr. 24-29. 1p. AbstractAfrica, Moroccogeochronology
DS1998-1527
1998
Bourassa, M.Vaughan, S., Bourassa, M., Cowan, S.New mining standards guidelines for mining exploration companies listed on the Vancouver Stock ExchangeNatural Resource and Energy Law, Vol. 5, No. 1, March pp. 1-3British ColumbiaLegal - mining law, Stock exchange - Vancouver
DS1997-1202
1997
Bourassa, M.J.Vaughan, W.S., Bourassa, M.J., Da Matta Ponte, K.Establishing a mineral regime conducive to exploration investmentPros. and dev. Association Canada, March pp. 46-53CanadaLegal - regulatory, Economics - mining
DS2001-0128
2001
Bourassa, M.J.Bourassa, M.J.International legal requirements and standards for mineral valuation. 43-101Valmin 01, Mineral Asset Valuation Oct. 25-6th., pp.62-84.CanadaEconomics - legal code, Mineral reserves, resources, valuation, exploration
DS202108-1277
2021
Bourbon, P.Derycke, A., Gautheron, C., Barbarand, J., Bourbon, P., Aertgeerts, G., Simon-Labric, T., Sarda, P., Pinna-Jamme, R., Boukari, C., Gaurine, F.French Guiana margin evolution: from Gondwana break-up to Atlantic Ocean.Terra Nova, Vol. 33, 4, pp. 415-422. pdfSouth America, French GuianaGuiana Shield

Abstract: Knowledge of the Guiana Shield evolution during the Gondwana break-up is key to a better understanding of craton dynamics and margin response to transtensional opening. To improve this knowledge, we investigated the dynamics and thermal evolution of French Guiana, using several low-temperature thermochronology methods applied to basement rocks, including apatite and zircon (U-Th)/He and apatite fission tracks. Inverse modelling of results allows us to reconstruct the Phanerozoic thermal history of French Guiana margin and to give a preview of the Guiana Shield evolution. Three main events are inferred: firstly, a long-term period of relative stability since ~1.2 Ga, with no strong evidence for any erosional or burial event (>5-7 km); secondly, a heating phase between ~210 and ~140 Ma consistent with the Central Atlantic Magmatic Province-related event. Finally, an exhumation phase between ~140 and ~90 Ma, triggered by the Equatorial Atlantic opening, brought samples close to the surface (<40°C).
DS1998-0463
1998
Bourdon, B.Gannoun, A., Birck, J.L., Bourdon, B., Allegre, C.J.Re Os systematics in orogenic peridotite massifs and contraints on the petrogenesis of pyroxenites.Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 496-7.Morocco, Spain, FranceUltramafics, Deposit - Beni Bouzra, Ronda, Lherz
DS1998-1290
1998
Bourdon, B.Schiano, P., Bourdon, B., Bottinga, Y.Low degree partial melting trends recorded in upper mantle mineralsEarth and Planetary Science Letters, Vol. 160, No. 3-4, Aug. 1, pp. 537-550.MantleMelt, Magmatism
DS1999-0194
1999
Bourdon, B.Elliott, T., Zindler, A., Bourdon, B.Exploring the kappa corundum: the role of recycling in the lead isotope evolution of the mantle.Earth and Planetary Science Letters, Vol. 169, No. 1-2, May 30, pp. 129-46.MantleGeochronology
DS1999-0628
1999
Bourdon, B.Schiano, P., Bourdon, B.On the preservation of mantle information in ultramafic nodules: glass inclusions within minerals versus insterstitial glasses.Earth and Planetary Science Letters, Vol. 169, No. 1-2, May 30, pp. 173-88.MantleGlass, mineralogy
DS2003-0142
2003
Bourdon, B.Bourdon, B., Turner, S., Dosseto, A.Dehydration and partial melting in subduction zones: constraints from U seriesJournal of Geophysical Research, Vol. 108, B6, 10.1029/2002JB001839 June 6MantleMelting, Subductioon
DS2003-0216
2003
Bourdon, B.Caro, G., Bourdon, B., Birck, J.L., Moorbath, S.146 Sm 142 Nd evidence from Isua metamorphosed sediments for early differentiationNature, No. 6938, May 22, p. 428-31.GreenlandGeochronology
DS2003-0217
2003
Bourdon, B.Caro, G., Bourdon, B., Birck, J.L., Moorbath, S.146 Sm 142 Nd evidence from Isua metamorphosed sediments for early differentiationNature, No. 6938, May 22, pp. 428-31.MantleGeochronology, Metamorphism
DS200412-0189
2003
Bourdon, B.Bourdon, B., Turner, S., Dosseto, A.Dehydration and partial melting in subduction zones: constraints from U series disequilibria.Journal of Geophysical Research, Vol. 108, B6, 10.1029/2002 JB001839 June 6MantleMelting, Subduction
DS200412-0283
2003
Bourdon, B.Caro, G., Bourdon, B., Birck, J.L., Moorbath, S.146 Sm 142 Nd evidence from Isua metamorphosed sediments for early differentiation of Earth's mantle.Nature, No. 6938, May 22, p. 428-31.Europe, GreenlandGeochronology
DS200412-0284
2003
Bourdon, B.Caro, G., Bourdon, B., Birck, J.L., Moorbath, S.146 Sm 142 Nd evidence from Isua metamorphosed sediments for early differentiation of the Earth's mantle.Nature, No. 6938, May 22, pp. 428-31.MantleGeochronology - metamorphism
DS200612-0136
2006
Bourdon, B.Bichert-Toft, J., Bourdon, B.Early mantle evolution.Goldschmidt Conference 16th. Annual, S4-03 theme abstract 1/8p. goldschmidt2006.orgMantleTechnology
DS200612-0155
2006
Bourdon, B.Bourdon, B., Van Orman, J.236 Ra deficits in OIB: a key to the rate of melt extraction in ther mantle.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.Europe, Cape Verde IslandsMelting
DS200612-1384
2006
Bourdon, B.Stracke, A., Bourdon, B., McKenzie, D.Melt extraction in the Earth's mantle: constraints from U Th Pa Ra studies in oceanic basalts.Earth and Planetary Science Letters, Vol. 244, 1-2, Apr. 15, pp. 97-112.Europe, IcelandGeodynamic melting
DS200812-0182
2008
Bourdon, B.Caro, G., Bennett, V.C., Bourdon, B., Harrison, T.M., Von Quadt, A., Mojzsis, S.J., Harris, J.W.Application of precise 142 Nd 144 Nd analysis of small samples to inclusions in diamonds ( Finsch SA ) and Hadean zircons ( Jack Hills, Western Australia).Chemical Geology, Vol. 247, 1-2, pp. 253-265.Africa, South Africa, AustraliaGeochronology
DS200812-1133
2009
Bourdon, B.Stracke, A., Bourdon, B.The importance of melt extraction for tracing mantle heterogeneity.Geochimica et Cosmochimica Acta, Vol. 73, 1, pp. 218-239.MantleGeochronology
DS200912-0536
2009
Bourdon, B.Nikolaeva, K.M., Gerya, T.V., Bourdon, B.Subduction dynamics and magmatic arc growth: numerical modeling of isotopic features.Goldschmidt Conference 2009, p. A944 Abstract.MantleSubduction
DS201112-1009
2011
Bourdon, B.Stracke, A., Snow, J.E., Hellebrand, E., Von der Handt, A., Bourdon, B., Birbaum, K., Gunther, D.Abyssal peridotite Hf isotopes identify extreme mantle depletion.Earth and Planetary Science Letters, Vol. 308, 3-4, pp. 359-368.Mantle, Europe, GreenlandGeochronology
DS201112-1010
2011
Bourdon, B.Stracke, A., Snow, J.E., Hellebrand, E., Von der Handt, A., Bourdon, B., Birbaum, K., Guther, D.Abyssal peridotite Hf isotopes identify extreme mantle depletion.Earth and Planetary Science Letters, Vol. 308, 3-4, pp. 359-368.OceanGakkel Ridge
DS201905-1018
2019
Bourdon, B.Bohm, C.O., Hartlaub, R.P., Heaman, L.M., Cates, N., Guitreau, M., Bourdon, B., Roth, A.S.G., Mojzsis, S.J., Blichert-Toft, J.The Assean Lake Complex: ancient crust at the northwestern margin of the Superior Craton, Manitoba, Canada.Earths Oldest Rocks, researchgate.com Chapter 28, 20p. Pdf availableCanada, Manitobacraton

Abstract: This chapter describes the Assean Lake Complex (ALC) at ancient crust at the Northwestern margin of the Superior Craton, Manitoba, and Canada. An initial tectonic model for the Assean Lake area indicated that a regionally extensive high-strain zone running through the lake marks the suture between Archean high-grade crustal terranes of the Superior Craton to the southeast and Paleoproterozoic rocks of the Trans-Hudson Orogen to the northwest. Detailed geologic remapping combined with isotopic and geochemical studies led to a re-interpretation of the crust immediately north of the Assean Lake high-strain zone as Mesoarchean. The study area straddles the boundary between the Archean Superior Craton and the ca.1.90-1.84 Ga arc and marginal basin rocks of the Trans-Hudson Orogen, which represent the remains of ca. 1.83-1.76 Ga ocean closure and orogeny. It is indicated that the gneisses of the Split Lake Block consist primarily of meta-igneous protoliths of gabbroic to granitic composition. Tonalite and granodiorite are the most volumetrically dominant, but an anorthosite dome is also present in the northeast. Mapping, isotopic, and age data combined with high-resolution aero-magnetic data indicate that the Mesoarchean ALC is a crustal slice up to 10 km wide, and has a strike length of at least 50 km.
DS202002-0167
2019
Bourdon, B.Bohm, C.O., Hartlaub, R.P., Heaman, L.M., Cates, N., Guitreau, M., Bourdon, B., Roth, A.S.G., Mojzsis, S.J., Blichert-Toft, J.The Assean Lake Complex: ancient crust at the northwestern margin of the Superior craton, Manitoba, Canada. ( not specific to diamonds)Earth's Oldest Rocks, Chapter 28, 20p. Pdf.Canada, Manitobacraton
DS202101-0035
2020
Bourdon, B.Turner, S., Turner, M., Bourdon, B., Cooper, K., Porcelli, D.Extremely young melt infiltration of the sub-continental lithospheric mantle.Physics of the Earth and Planetary Interiors, doi.org/10.1016/ j.pepi.2-19.106325 54p. PdfMantlemelting

Abstract: It has long been inferred that mantle metasomatism and the incompatible element enrichment of the continents both require movement of melts formed by very low degree melting of the mantle. Yet establishing the presence of these melts and whether this process is on-going and continuous, or spatially and temporally restricted, has proved difficult. Here we report large U-Th-Ra disequilibria in metasomatised, mantle xenoliths erupted in very young lavas from the Newer Volcanics Province in southeastern Australia. The 226Ra-230Th disequilibria appear to require reappraisal of previous estimates for the age of eruption that now seems unlikely to be more than a few kyr at most. We propose that infiltration of carbonatitic melts/fluids, combined with crystallization of pargasite, can account for the first order U-series disequilibria observations. Irrespective of the exact details of the complex processes responsible, the half-lives of the nuclides require that some of the chemical and isotopic disturbance was extremely young (« 8?kyr) and potentially on-going at the time of incorporation into the alkali basalts that transported the xenoliths to the surface. This provides evidence for the presence and possibly continuing migration of small melt fractions (~0.02%) in the upper convecting mantle that may contribute to the seismic low velocity zone. By implication, it appears that the asthenosphere must lie close to its solidus, at least in this region. Pressure-temperature estimates indicate that the small degree melts identified could infiltrate as far as 25?km upwards into the sub-continental lithospheric mantle leading to strong incompatible element enrichment and the recent timing of this event this urges a reappraisal of the meaning of 300-500?Ma Nd model ages in mantle xenoliths from this region. In principle, the resultant metasomatised mantle could provide a component for some ocean island basalts, should the sub-continental lithospheric mantle be returned to the asthenosphere by convective removal at some later time.
DS1995-0129
1995
Bourdon, E.Becquer, T., Bourdon, E., Petard, J.Disponibilite du nickel le long d'une toposequence de sols developpes surroches ultramafiques N. CaledoniaC.r. Academy Of Science Paris, Vol. 321, 11a, pp. 585-592New CaledoniaNickel, Ultramafics
DS2000-0373
2000
Bourdon, E.Gutscher, M-A., Maury, R., Eissen, J-P., Bourdon, E.Can slab melting be caused by flat subduction?Geology, Vol. 28, No. 6, June pp. 535-8.Chile, Ecuador, Costa RicaThermometry - thermal structure, Adakites
DS2001-0129
2001
Bourdon, E.Bourdon, E., Hemond, C.Looking for the missing endmember in South Atlantic Ocean mantle around Ascension Island.Mineralogy and Petrology., Vol. 71, No. 1-2, pp. 127-38.MantleGondwana
DS201312-0091
2013
BourevestnikBourevestnikPortable sorter Polus-Mmarketing @bourevestnik.spb.ru, 2p. In englishTechnologyField sorter
DS201412-0220
2014
Bourg, I.Eiler, J.M., Berquist, B., Bourg, I., Cartigny, P., Farquhar, J., Gagnon, A., Guo, W., Halevy, I., Hofman, A., larson, T.E., Levin, N., Schauble, E.A., Stolper, D.Frontiers of stable isotope geoscience.Chemical Geology, Vol. 372, pp. 119-143.TechnologyReview of isotopes
DS1991-0157
1991
Bourgault, G.Bourgault, G., Marcotte, D.Multivariable variogram and its application to the linear model ofcoregionalizationMath. Geol, Vol. 23, No. 7, pp. 899-928GlobalGeostatistics, Variograms
DS1992-0150
1992
Bourgault, G.Bourgault, G., Marcotte, D., Legendre, P.The multivariate (Co) variogram as a spatial weighting function in classification methodsMathematical Geology, Vol. 24, No. 4, pp. 463-478GlobalComputer, cobalt, Program -Multivariate variograM.
DS2000-0242
2000
Bourgault, H.Dosso, L., Bourgault, H., Vlastelic, I.Heterogeneity of the sub oceanic depleted mantleIgc 30th. Brasil, Aug. abstract only 1p.MantleTectonics
DS1998-0146
1998
Bourgeois, O.Bourgeois, O., Dauteruil, O., Van Vliet-Lanoe, B.Pleistocene subglacial volcanism in Iceland: tectonic implicationsEarth and Planetary Science Letters, Vol. 164, No.1-2, Dec.15, pp. 165-78.GlobalGeomorphology, Tectonics
DS201312-0187
2013
Bourgeois, O.Dauteuil, O., Deschamps, F., Bourgeois, O., Mocquet, A., Guillocheau, F.Post breakup evolution and paleotopography of the North Namibia margin during the Meso-Cenozoic.Tectonophysics, Vol. 589, pp. 103-115.Africa, NamibiaTectonics
DS1992-0151
1992
Bourgine, B.Bourgine, B.Advanced interpolation: kriging with external drift and conditionalsimulationsGeobyte, Vol. 7, No. 5, pp. 42-46GlobalGeostatistics, Kriging
DS1990-0131
1990
Bourgois, J.Aubouin, J., Bourgois, J.Tectonics of circum Pacific continental marginsV.s.p. Publ, 244p. approx. $ 100.00 United StatesPacific OceanTectonics, Book -ad
DS200512-0337
2004
Bourgois, J.Gill, R.C., Aparicio, A., El Azzouzi, M., Hernandez, J., Thirlwall, M.F., Bourgois, J., Marriner, G.F.Depleted arc volcanism in the Alboran Sea and shoshonitic volcanism in Morocco: geochemical and isotopic constraints on Neogene tectonic processes.Lithos, Vol. 78, 4, pp. 363-388.Africa, MoroccoShoshonite
DS1996-0159
1996
Bourgopis, J.Bourgopis, J., Martin, H., Lagabrielle, Y., et al.Subduction erosion related to spreading ridge subduction: Titao peninsula(Chile triple junction)Geology, Vol. 24, No. 8, August pp. 723-726ChileSubduction, Tectonics
DS202005-0748
2020
Bourke, P.Mackensie, S., Everingham, J-A., Bourke, P.The social dimensions of mineral exploration. Not specific to diamonds - but interestSEG Discovery ( former NewsLetter), No. 121, April, pp. 16-28.Globalgeoscience

Abstract: Geoscientists are often the first point of contact a local community has with a company conducting mineral exploration. The behavior of the geoscientists and the interest they take in understanding the local community and stakeholders will have ramifications well beyond their direct exploration activities. This article highlights some of the positive and negative impacts exploration can have for local communities (in part drawing on interviews with experienced geoscientists and others involved in exploration). The article explores the increasing complexity of deposits in terms of environmental, economic, social, and political parameters and the increasing scrutiny by local stakeholders and the international community. We argue that, although geoscientists are not social performance specialists, they still need the awareness, tools, and capabilities to understand and manage the social aspects of their exploration activities commensurate with the stage and resourcing of the project. We propose three interrelated aspects of social performance that can be applied during mineral exploration: meaningful and positive engagement, acquiring and documenting a social knowledge base, and strategic investment in the community. Two case studies provide cautionary examples of failure to do so and two case studies highlight how, through careful engagement and strategic collaboration, mutually beneficial and positive relationships can be built from early exploration.
DS1994-0216
1994
Bourles, D.I.Brown, E.T., Bourles, D.I., Colin, F., et al.The development of iron crust lateritic systems in Burkin a Faso: examine din situ produced cosmogenic nuclidesEarth and Planetary Science Letters, Vol. 124, No. 1/4, June pp. 19-34Burkina Faso, West AfricaLaterites, Duricrust
DS201412-0038
2014
Bourles, D.L.Barreto, H.N., Varajao, C.A.C., Braucher, R., Bourles, D.L., Salgado, A.A.R, Varajao, A.F.D.C.The impact of diamond extraction on natural denudation rates in the Diamantin a Plateau ( Min as Gerais, Brazil).Journal of South American Earth Sciences, Vol 56, pp. 357-364.South America, BrazilMining
DS2002-0194
2002
Bourlon, E.Bourlon, E., Mareschal, J.C., Roest, W.R., Telmat, H.Geophysics correlations in the Ungava Bay areaCanadian Journal of Earth Science, Vol.39,5, May, pp.625-37.Quebec, Labrador, Baffin IslandGeophysics - gravity, magnetics, Tectonics
DS1993-0145
1993
Bourman, R.P.Bourman, R.P.Perennial problems in the study of laterite: a reviewAustralian Journal of Earth Sciences, Vol. 40, pp. 387-401AustraliaLaterite, Review
DS201809-2000
2018
Bourmatte, A.Brahimi, S., Ligeois, J-P., Ghienne, J-F., Munschy, M., Bourmatte, A.The Tuareg shield terranes revisited and extended towards the northern Gondwana margin: magnetic and gravimetric constraints.Earth Science Reviews, Vol. 185, Doi: 10.1016/j.earscirev. 2018.07.002Africa, AlgeriaGondwanaland

Abstract: Kimberlite is the host rock of diamonds and varies widely in geological and mineralogical features as well as color, processing capability, and dewatering characteristics. This study investigated the dewatering behavior of problematic Angolan kimberlites. The presence of clay minerals in kimberlite causes difficulties in dewatering due to high flocculant demand, poor supernatant clarity, and low settling rates. Identifying critical parameters governing the settling behavior will assist in managing the settling behavior of different kimberlite slurries. The influence of particle size, pH of the kimberlite slurry, cation exchange capacity, exchangeable sodium percentage, and smectite content of the kimberlite on the settling rate were investigated for 18 different African kimberlite samples. The settling rate and slurry bed compaction during natural settling were also measured for the kimberlite slurries. Seventeen different Angolan clay-rich kimberlites and one South African clay-rich kimberlite were tested, and, except for two kimberlites, colloidal stability was experienced during natural settling. The pH values of the kimberlite slurries ranged between 9 and 11, which is similar to the pH band where colloidal stability was found during earlier research. The results indicate that colloidal stable slurries were experienced with kimberlites that had exchangeable sodium percentages as low as 0.7%. The cation exchange capacity of the various kimberlites differentiated more distinctly between colloidal stability and instability. A new model is proposed whereby clay-rich kimberlites with a cation exchange capacity of more than 10cmol/kg will experience colloidal stability if the pH of the solvent solution is within the prescribed pH range of 9-11.The Trans-Saharan Belt is one of the most important orogenic systems constitutive of the Pan-African cycle, which, at the end of the Neoproterozoic, led to the formation of the Gondwana Supercontinent. It is marked by the opening and closing of oceanic domains, collision of continental blocks and the deformation of thick synorogenic sedimentary basins. It extends from north to south over a distance of 3000?km in Africa, including the Nigerian Shield and the Tuareg Shield as well as their counterparts beneath the Phanerozoic oil-rich North- and South-Saharan sedimentary basins. In this study, we take advantage of potential field methods (magnetism and gravity) to analyze the crustal-scale structures of the Tuareg Shield terranes and to track these Pan-African structures below the sedimentary basins, offering a new, >1000?km extent. The map interpretations are based on the classical potential field transforms and two-dimensional forward modeling. We have identified geophysical units and first-order bounding lineaments essentially defined owing to magnetic and gravimetric anomaly signatures. In particular, we are able to highlight curved terminations, which in the Trans-Saharan context have been still poorly documented. We provide for the first time a rheological map showing a categorization of contrasted basement units from the south of the Tuareg Shield up to the Atlas Belt. These units highlight the contrasted rheological behavior of the Tuareg tectonostratigraphic terranes during (i) the northerly Pan-African tectonic escape characteristic of the Trans-Saharan Belt and (ii) the North Sahara basin development, especially during intraplate reworking tied to the Variscan event. The discovery of a relatively rigid E-W oriented unit to the south of the Atlas system, and on which the escaping Pan-African terranes were blocked, offers a new perspective on the structural framework of the north-Gondwana margin. It will help to understand how occurred the rendezvous of the N-S oriented Pan-African terranes and the E-W oriented Cadomian peri-Gondwanan terranes.
DS201807-1478
2018
Bournas, N.Bournas, N., Prikhodko, A., Plastow, G., Legault, J., Polianichko, V., Treshchev, S.Exploring for kimberlite pipes in the Cuango area, Angola using helicopter-borne EM survey.AEM2018/7th International Workshop on Airborne electromagnetics, Held June 17-20, 4p.Africa, Angolageophysics - TEM
DS2000-0232
2000
BourneDigonnet, S., Goulet, N., Bourne, Stevenson, ArchibaldPetrology of the Abloviak aillikite dykes, New Quebec: evidence for Cambrian Diamondiferous alkaline provinceCanadian Journal of Earth Sciences, Vol. 37, No. 4, Apr. pp. 517-33.Quebec, Labrador, UngavaMineral chemistry - analyses, petrography, age, Geochronology, tectonics
DS201910-2254
2019
Bourne, B.Dentith, M., Enkin, R.J., Morris, W., Adams, C., Bourne, B.Petrophysics and mineral exploration: a workflow for data analysis and a new interpretation framework. ( Not specific to diamonds)Geophysical Prospecting, htpps://doi.org/10.1111/1365-2478.12882Globalgeophysics - seismic

Abstract: As mineral exploration seeks deeper targets there will be a greater reliance on geophysical data and a better understanding of the geological meaning of the responses will be required, and this must be achieved with less geological control from drilling. Also, exploring based on the mineral system concept requires particular understanding of geophysical responses associated with altered rocks. Where petrophysical datasets of adequate sample size and measurement quality are available, physical properties show complex variations, reflecting the combined effects of various geological processes. Large datasets, analysed as populations, are required to understand the variations. We recommend the display of petrophysical data as frequency histograms as the nature of the data distribution is easily seen with this form of display. A petrophysical data set commonly contains a combination of overlapping sub?populations, influenced by different geological factors. To understand the geological controls on physical properties in hard rock environments it is necessary to analyse the petrophysical data not only in terms of the properties of different rock types. It is also necessary to consider the effects of processes such as alteration, weathering, metamorphism, and strain, and variables such as porosity and stratigraphy. To address this complexity requires that much more supporting geological information be acquired than is current practice. The widespread availability of field portable instruments means quantitative geochemical and mineralogical data can now be readily acquired, making it unnecessary to rely primarily on categorical rock classification schemes. The petrophysical data can be combined with geochemical, petrological and mineralogical data to derive explanations for observed physical property variations based not only on rigorous rock classification methods, but also in combination with quantitative estimates of alteration and weathering. To understand how geological processes will affect different physical properties it is useful to define three end?member forms of behaviour. Bulk behaviour depends on the physical properties of the dominant mineral components. Density and, to a lesser extent, seismic velocity show such behaviour. Grain and texture behaviour occur when minor components of the rock are the dominate controls on its physical properties. Grain size and shape control grain properties, and for texture properties the relative positions of these grains are also important. Magnetic and electrical properties behave in this fashion. Thinking in terms of how geological processes change the key characteristics of the major and minor mineralogical components allows the resulting changes in physical properties to be understood and anticipated.
DS1994-0190
1994
Bourne, B.T.Bourne, B.T., Trench, A., Dentith, M.C., Ridley, J.Physical property variations within Archean granite greenstone terrane..the influence of metamorphic gradeAseg Volume, Vol. 24, No. 3, 4, pp. 367-374Australiametamorphism, Yilgarn Craton
DS1989-0153
1989
Bourne, H.L.Bourne, H.L.What it's worth: a review of mineral royalty information. *prev. listed as a preprintMining Engineering, Vol. 41, No. 7, July pp. 541-544. Database #16975GlobalEconomics, Royalty information
DS1989-0154
1989
Bourne, H.L.Bourne, H.L.Mineral royaltiesAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint held Las Vegas Feb. 27-March 2, 1989, No. 89-176, 6p. Database # 17651United StatesEconomics, Legalities -brief outlines
DS1990-0228
1990
Bourne, H.L.Bourne, H.L.What it's worth: a review of mineral royalty information #1Mining Engineering, Vol. 42, No. 7, July pp. 676-680GlobalEconomics, Royalty information
DS1991-0158
1991
Bourne, H.L.Bourne, H.L.What it's worth: a review of mineral royalty information #2Mining Engineering, Vol. 43, No. 7, July pp. 728-731GlobalEconomics, Royalties
DS1992-0152
1992
Bourne, H.L.Bourne, H.L.What it's worth: a review of mineral royalty information #3Mining Engineering, Vol. 44, No. 7, July pp. 684-689GlobalEconomics, Geostatistics -ore reserves
DS1993-0146
1993
Bourne, H.L.Bourne, H.L.What its worth: a review of mineral royalty information... 12th. year hehas produced this for this journalMining Engineering, Vol. 45, No. 7, July pp. 710-713United StatesEconomics, royalty, Geostatistics
DS1994-0191
1994
Bourne, H.L.Bourne, H.L.What its worth: a review of mineral royalty informationMining Engineering, Vol. 46, No. 7, July pp. 641-644United StatesEconomics, Royalty
DS1996-0160
1996
Bourne, H.L.Bourne, H.L.What it's worth: a review of mineral royalty information and expanded list of actual companiesMining Engineering, Vol. 48, No. 7, July p. 35-38GlobalEconomics, Royalties - list of companies
DS1989-0296
1989
Bourne, J.Corriveau, L., Gold, D., Bedard, J., Bourne, J.Alkaline and calc-alkaline complexes of southern QuebecGeological Association of Canada (GAC) Field Trip, Trip No. B3, May 17-21, 129pQuebecKensington Pluton, Monteregian Hills, Saint Dorothea Roya, Mount Johnson, Mount Mega
DS1996-0364
1996
Bourne, J.Digonnet, S., Bourne, J.Structural control of Ablociak kimberlite dykes, eastern part of UngavaBay, Quebec.Geological Society of America, Abstracts, Vol. 28, No. 7, p. A-247.QuebecKimberlite, Dykes
DS1996-0366
1996
Bourne, J.Digonnet. S., Goulet, N., Bourne, J., Stevenson, R.Modele de mise en place des kimberlites diamantiferes dans les Torngats:Nouveau Quebec.Quebec Information Seminar, DV 96-02, p. 18.Quebec, Ungava, LabradorKimberlite - genesis, Torngat Mountains
DS1998-0349
1998
Bourne, J.Digonnet, S., Bourne, J., Goulet, N.Chimie crystalline de grenats and radite et implication dans la petrogenesedes kimberlites d'abloviak.University of Quebec, pp. 68-72Quebec, Ungava, LabradorDike - geochemistry
DS1998-1494
1998
Bourne, J.A.Twidale, C.R., Bourne, J.A.The use of duricrusts and topographic relationships in geomorphologicalcorrelation: conclusions based..AusCatena, Vol. 33, No. 2, Aug. 1, pp. 105-122AustraliaGeopmorphology, Duricrusts
DS1991-0159
1991
Bourne, J.H.Bourne, J.H., Bosse, J.Geochemistry of ultramafic and calc-alkaline lamprophyres from the Lac Shortt area, QuebecMineralogy and Petrology, Vol. 45, No. 2, pp. 85-104QuebecGeochemistry, Alkaline rocks, lamprophyres
DS1991-0160
1991
Bourne, J.H.Bourne, J.H., l'Heureux, M.The petrography and geochemistry of the Clericy Pluton: an ultrapotassic pyroxenite-syenite suite of late Archean age from the Abitibi region, QuebecPrecambrian Research, Vol. 52, No. 1-2, pp. 37-51QuebecUltrapotassic, Geochemistry
DS1992-1230
1992
Bourne, J.H.Preciozzi, F., Bourne, J.H.Petrography and geochemistry of the Arroyo de la Virgen and Isla Malaplutons, southern Uruguay: early Proterozoic tectonic implicationsJournal of South American Earth Sciences, Vol. 6, No. 3, October pp. 169-182UruguayGeochemistry, Tectonics
DS1995-2106
1995
Bourne, J.H.Yong, S., Bourne, J.H.Possible compositional differences Archean Post Archean granulite terranes based on discriminant analysisMineralogy and Petrology, Vol. 54, No. 3-4, pp. 175-190AustraliaArchean, Geochemistry
DS1996-0365
1996
Bourne, J.H.Digonnet, S., Goulet, N., Bourne, J.H., Stevenson, R.Genesis and comparison of kimberlite dykes from the Ungava Bay area, north Quebec and from West GreenlandLithoprobe Report, No. 57, pp. 38-43.Quebec, Ungava, Labrador, GreenlandDike - geochemistry
DS1995-0187
1995
Bourne, L.Bourne, L.What its worth: review of mineral royalty informationMining Engineering, Vol. 47, No. 7, July pp. 654-657United StatesEconomics, Royalty
DS1998-0147
1998
Bourne, S.J.Bourne, S.J., England, P.C., Parsons, B.The motion of crustal blocks driven by flow of the lower lithosphere And implications for slip rates ...Nature, Vol. 391, No. 6668, Feb. 12, pp. 655-59.MantleLithosphere, Strike slip faults
DS2001-0246
2001
BouroisDerder, M.E.M., Henry, B., Merabet, N., Amenna, BouroisUpper Carboniferous paleomagnetic pole from the stable Saharan Craton and Gondwana reconstructions.Journal of African Earth Science, Vol. 32, No. 3, Apr. pp. 491-502.South AfricaGeophysics - paleomagnetism, Gondwanaland
DS200812-0637
2008
Bourot-Denise, M.Le Guillou, C., Rouzaud, J.N., Bourot-Denise, M., Remusat, L., Jambion, A.Laboratory shock synthesized diamond vs carbons from a differentiated meteorite.Goldschmidt Conference 2008, Abstract p.A532.Urelilite
DS200612-0156
2006
Bourova, E.Bourova, E., Richet, P., Petitet, J-P.Coesite ( SiO2) as an extreme case of superheated crystal: an X-ray diffraction study up to 1776 K.Chemical Geology, Vol. 229, 1-3, May 16, pp. 57-63.TechnologyMineralogy - coesite
DS1991-0098
1991
Bouroz, C.Bergerat, F., Angelier, J., Bouroz, C.Jointing analysis in the Colorado Plateau (USA) as a key to paleostressreconstruction. (in French)Comptes Rendus Academy of Science Series, (in French), Vol. 312, No. 3, pp. 309-316Colorado PlateauBlank
DS1994-0192
1994
Bourque, Y.Bourque, Y.Rapports des travaux projet du la Castignon, nouveau Quebec. Societe Miniere Ecudor Inc.Quebec Department of Mines, GM 52771, 19p.QuebecExploration - assessment, Societe Miniere Ecudor Inc.
DS200412-1109
2004
Bourrouilh, R.LeFort, J.P., Aifa, T., Bourrouilh, R.Paleomagnetic and paleontologic evidence for an antipodal position of the West African Craton and of norther Chin a in Rodinia puComptes Rendus Geoscience, Vol. 336, 2, Feb. pp. 159-165.ChinaGeophysics - magnetism
DS200612-0157
2006
Bousquet, R.Bousquet, R., De Capitani, C., Arcay, D.Feedback of the metamorphic changes on the subducting processes.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.MantleSubduction
DS200912-0680
2009
Bousquet, R.Sebti, S., Saddiqi, O., El Haimer, F.Z., Michard, A., Ruiz, G., Bousquet, R., Baidder, L., Frizonde Lamotte, D.Vertical movements at the fringe of the West African Craton: first zircon fission track datings from the Anti Atlas Precambrian basement, Morocco.Comptes Rendus Geoscience, Vol. 341, no. 1, pp. 71-77.Africa, MoroccoTectonics
DS200612-0032
2006
Bousquet, R.D.Arcay, D., Doin, M-P., Tric, E., Bousquet, R.D.Overriding plate thinning in subduction zones: localized convection induced by slab dehydration.Geochemistry, Geophysics, Geosystems: G3, Vol. 7, Q02007MantleGeothermometry, hydrated slab-derived water fluxes
DS200712-0024
2007
Bousquet, R.D.Arcay, D., Doin, M-P., Tric, E., Bousquet, R.D.Influence of the precollisional stage on subduction dynamics and the buried crust thermal state: insights from numerical simulations.Tectonophysics, Vol. 441, pp. 27-45.MantleSubduction
DS200512-0673
2005
Boussuge, M.Madi, K., Forest, S., Cordier, P., Boussuge, M.Numerical study of creep in two phase aggregates with a large rheology contrast: implications for the lower mantle.Earth and Planetary Science Letters, Vol. 237, 1-2, Aug, 30, pp. 223-238.MantleSeismic anistropy
DS1860-0458
1885
Boutan, E.Boutan, E.Le Diamant (1885)Unknown, 323P. INDIA PP. 3-121; Brasil PP. 122-150; SOUTH AFRICA Australia, Asia, Borneo, South America, Brazil, India, Africa, South Africa, Russia, United StatesDiamond Occurrences
DS1860-0617
1889
Boutan, E.Boutan, E.Sur L'etat Actual des Mines de Diamant Au CapParis: Genie Civil, Vol. 14, P. 186.Africa, South AfricaDiamond mining
DS1860-0618
1889
Boutan, E.Boutan, E.On the Present State of the Cape Diamond MinesLondon: Worrall And Robey, 28P.Africa, South Africa, Griqualand WestGeology
DS200512-0596
2005
Boutelier, D.Lallemand, S., Heuret, A., Boutelier, D.On the relationship between slab dip, back arc stress, upper plate absolute motion, and crustal nature in subduction zones.Geochemistry, Geophysics, Geosystems: G3, Vol. 6, Q12J14, doi:10.1029/2005 GC000917MantleSubduction, geodynamics
DS200812-0130
2008
Boutelier, D.A.Boutelier, D.A., Chemende, A.I.Exhumation of UHP/LT rocks due to the local reduction of the interplate pressure: thermo mechanical modelling.Earth and Planetary Science Letters, Vol. 271, 1-4, pp. 226-232.MantleUHP
DS200812-0131
2008
Boutelier, D.A.Boutelier, D.A., Cruden, A.R.Impact of regional mantle flow on subducting plate geometry and interplate stress: insights from physical modelling.Geophysical Journal International, Vol. 174, 2, pp. 719-732.MantleSubduction
DS2003-0143
2003
Boutilier, R.Boutilier, R., Thomson, I.Assessing the state of stakeholder relationshipsMining Environmental Management, Vol. 11, 2, March pp. 12-15.GlobalNews item - sustainable development
DS200412-0190
2003
Boutilier, R.Boutilier, R., Thomson, I.Assessing the state of stakeholder relationships.Mining Environmental Management, Vol. 11, 2, March pp. 12-15.GlobalNews item - sustainable development
DS1994-0193
1994
Boutilier, R.R.Boutilier, R.R., Keen, C.E.Geodynamic models of fault controlled extensionTectonics, Vol. 13, No. 2, April pp. 439-454GlobalStructure, Fault models
DS1994-0194
1994
Boutilier, R.R.Boutilier, R.R., Keen, C.E.Geodynamic models of fault contolled extensionTectonics, Vol. 13. No. 2, Apr. pp. 439-54.MantleGeodynamics
DS1999-0086
1999
Boutilier, R.R.Boutilier, R.R., Keen, C.E.Small scale convection and divergent plate boundariesJournal of Geophysical Research, Vol. 104, No. 4, Apr. 10, pp. 7389-7404.MantleBoundaries, Tectonics
DS2000-0476
2000
Boutilier, R.R.Keen, C.E., Boutilier, R.R.Interaction of rifting and hot horizontal plume sheets at volcanic marginsJournal of Geophysical Research, Vol. 105, No. 6, June 10, pp. 13375-MantleTectonics - rifting, Plumes
DS202111-1758
2020
Boutyon, A.Boutyon, A., Klausen, M., Mata, J., Tappe, S., Farquhar, J., Cartigny, P.Multiple sulfur isotopes of carbonatites, a window into their formation conditions.Goldschmidt2020, 1p. Abstract pdfMantlecarbonatite

Abstract: Carbonatites are rare volcanic rocks whose carbon/oxygen isotope signatures point towards a mantle origin. However there is still debate on the role of processes such as partial melting or the recycling of sediments for their generation. Carbonatite quadruple sulfur isotope measurements should be useful for deciphering the imprints of Earth’s earliest atmosphere and microbial cycling, two processes isotopically characterized by different slopes in a ?33S-?36S diagram, and thus help to better understand the origin of carbonatites, and the possiblity of sedimentary precursors, in greater detail. We report here multiple sulfur data for a wide range of carbonatite samples: 4 continents, from today to 3Ga, oceanic and continental settings. 80 measurements from 18 localities yielded sulfur in sulfides between 0 to 1wt%, with ?34S ranging from -20‰ to +10‰. The record through time seems to correlate with the sedimentary record albeit with some delay. ?33S varies between -0.1 to 0.4‰. Most of the samples display unequivocal mass-dependent fractionation, characteristic of the sedimentary record. A few samples show mass-independent fractionation. ?33S shows a temporal variation from near zero at 3Ga to positive values until 500Ma and then a broadening with both positive and negative values. This is interpreted to reflect the assimilation of surface derived sulfur in the source of carbonatites. The mixing with mantle sulfur narrows the amplitude of the variation and a crustal imprint could blur the signal as well. However coupled ?34S-?33S point toward two different stages in the sulfur isotopic signature: a long recycling before 900Ma and a much shorter residence time, on the order of 300 Myrs, after. This could be linked with a preferential recycling of sulfides in the early time and a recycling of both sulfides and sulfates later on.
DS201904-0727
2019
Bouvais, P.Decree, S., Demaiffe, D., Tack, L., Nimpagaritse, G., De Paepe, P., Bouvais, P., Debaille, V.The Neoproterozoic Upper Ruvubu alkaline plutonic complex ( Burundi) revisited: large scale syntectonic emplacement, magmatic differentiation and late stage circulations of fluids.Precambrian Research, Vol. 325, pp. 150-171.Africa, Burundicarbonatite

Abstract: The Upper Ruvubu Alkaline Plutonic Complex (URAPC) in Burundi consists of three separate intrusions, each with a specific emplacement age and petrological composition. Three main units are recognized: an outer unit with silica-saturated plutonic rocks (from gabbro to granite), an inner unit with silica-undersaturated plutonic rocks (feldspathoidal syenite with subordinate feldspathoidal monzonite and ijolite) and a carbonatitic body in the subsoil, known by drilling. The URAPC is quite large in size (?24?km long and up to 10?km wide). It is considered to have been intruded syntectonically in an overall extensional context, thanks to the kilometric shear zones that accommodated its emplacement. Radiometric ages from literature range from 748 to 705?Ma and point to structurally-controlled magmatic differentiation followed by long-lived circulations of late-stage fluids postdating the emplacement of a part of the undersaturated rocks and the carbonatites. In the north-western part of the outer unit, gabbro likely has been emplaced at a deeper structural level than the granite, which represents a more apical structural level of emplacement. This petrological, geochemical and isotopic (Sr-Nd-Hf) study concentrates on the processes that generated the URAPC: (i) fractional crystallization, evidenced by the chemical evolution trends of the major and trace elements, and by marked P, Ti and Ba anomalies in the trace element patterns; (ii) crustal assimilation/contamination, as shown by the wide range of Nd isotope compositions and the general increase of the Sr isotope ratios with increasing SiO2 contents, and (iii) late-magmatic/hydrothermal alteration inducing an increase of the Sr isotope composition without changing significantly the Nd isotope composition. The isotopic data are consistent with an asthenospheric mantle source, though less depleted than the Depleted Mantle (DM), contaminated by the Subcontinental Lithospheric Mantle (SCLM). The silicate and carbonate magmatic series are cogenetic. The outer unit is clearly more contaminated than the inner unit, whereas the carbonatitic body could have evolved by liquid immiscibility. The URAPC lies within East Africa’s Western Rift Valley, which is marked by 23 alkaline plutonic complexes. Their emplacement has been ascribed to reactivation of Proterozoic lithospheric weakness zones resulting from the breakup of the Neoproterozoic supercontinent Rodinia supercontinent.
DS201806-1222
2018
Bouvier, A.S.Engi, M., Giuntoli, F., Lanari, P., Burn, M., Kunz, B., Bouvier, A.S.Pervasive eclogization due to brittle deformation and rehydration of subducted basement: effects on continental recycling?Geochemistry, Geophysics, Geosystems, Vol. 19, 3, pp. 865-881.Mantlesubduction

Abstract: The buoyancy of continental crust opposes its subduction to mantle depths, except where mineral reactions substantially increase rock density. Sluggish kinetics limit such densification, especially in dry rocks, unless deformation and hydrous fluids intervene. Here we document how hydrous fluids in the subduction channel invaded lower crustal granulites at 50-60 km depth through a dense network of probably seismically induced fractures. We combine analyses of textures and mineral composition with thermodynamic modeling to reconstruct repeated stages of interaction, with pulses of high-pressure (HP) fluid at 650-6708C, rehydrating the initially dry rocks to micaschists. SIMS oxygen isotopic data of quartz indicate fluids of crustal composition. HP growth rims in allanite and zircon show uniform U-Th-Pb ages of 65 Ma and indicate that hydration occurred during subduction, at eclogite facies conditions. Based on this case study in the Sesia Zone (Western Italian Alps), we conclude that continental crust, and in particular deep basement fragments, during subduction can behave as substantial fluid sinks, not sources. Density modeling indicates a bifurcation in continental recycling: Chiefly mafic crust, once it is eclogitized to >60%, are prone to end up in a subduction graveyard, such as is tomographically evident beneath the Alps at 550 km depth. By contrast, dominantly felsic HP fragments and mafic granulites remain positively buoyant and tend be incorporated into an orogen and be exhumed with it. Felsic and intermediate lithotypes remain positively buoyant even where deformation and fluid percolation allowed them to equilibrate at HP.
DS201805-0990
2018
Bouvier, A-S.Wang, H.A.O., Cartier, L.E., Baumgartner, L.P., Bouvier, A-S., Begue, F., Chalain, J-P., Krzemnicki, M.S.A preliminary SIMS study using carbon isotopes to separate natural from synthetic diamonds.Journal of Gemmology, Vol. 36, 1, pp. 38-43.Technologysynthetics
DS202102-0187
2021
Bouvier, A-S.Fichtner, C.E., Schmidt, M.W., Liebske, C., Bouvier, A-S., Baumgartner, L.P.Carbon partitioning between metal and silicate melts during Earth accretion.Earth and Planetary Science Letters, Vol. 554, doi.org/10.1016/ j.epsl.2020. 116659 12p . PdfMantlecarbon

Abstract: In the accreting Earth and planetesimals, carbon was distributed between a core forming metallic melt, a silicate melt, and a hot, potentially dense atmosphere. Metal melt droplets segregating gravitationally from the magma ocean equilibrated near its base. To understand the distribution of carbon, its partitioning between the two melts is experimentally investigated at 1.5-6.0 GPa, 1300-2000 °C at oxygen fugacities of ?0.9 to ?1.9 log units below the iron-wuestite reference buffer (IW). One set of experiments was performed in San Carlos olivine capsules to investigate the effect of melt depolymerization (NBO/T), a second set in graphite capsules to expand the data set to higher pressures and temperatures. Carbon concentrations were analyzed by secondary ionization mass spectrometry (SIMS) and Raman spectra were collected to identify C-species in the silicate melt. Partition coefficients are governed by the solubility of C in the silicate melt, which varies from 0.01 to 0.6 wt%, while metal melts contain ?7 wt% C in most samples. C solubility in the silicate melt correlates strongly with NBO/T, which, in olivine capsules, is mostly a function of temperature. Carbon partition coefficients DCmetal/silicate at 1.5 GPa, 1300-1750 °C decrease from 640(49) to 14(3) with NBO/T increasing from 1.04 to 3.11. For the NBO/T of the silicate Earth of 2.6, DCmetal/silicate is 34(9). Pressure and oxygen fugacity show no clear effect on carbon partitioning. The present results differ from those of most previous studies in that carbon concentrations in the silicate melt are comparatively higher, rendering C to be about an order of magnitude less siderophile, and the discrepancies may be attributed to differences in the experimental protocols. Applying the new data to a magma ocean scenario, and assuming present day mantle carbon mantle concentrations from 120 to 795 ppm, implies that the core may contain 0.4-2.6 wt% carbon, resulting in 0.14-0.9 wt% of this element for the bulk Earth. These values are upper limits, considering that some of the carbon in the modern silicate Earth has very likely been delivered by the late veneer.
DS201412-0940
2014
Bouwer, W.Van der Westhuyzen, P., Bouwer, W., Jakins, A.Current trends in the development of new or optimization of existing diamond processing plants, with focus on beneficiation.South African Institute of Mining and Metallurgy, Vol. 114, July pp. 537-546.TechnologyDiamond processing plants
DS201112-0039
2011
Bouybaouene, M.Atrassi, F.E.L., Brunet, F., Bouybaouene, M., Chopin, C., Chazot, G.Melting textures and microdiamonds preserved in graphite pseudomorphs from Beni Bousera peridotite Massif, Morocco.European Journal of Mineralogy, Vol. 23, 2, pp. 157-168.Europe, Africa, MoroccoMicrodiamonds
DS201312-0239
2013
Bouybaouene, M.El Atrassi, F., Brunet, F., Chazot, G., Bouybaouene, M., Chopin, C.Metamorphic and magmatic overprint of garnet pyroxenites from the Beni Bousera massif ( northern Morocco): petrography, mineral chemistry and thermobarometry.Lithos, Vol. 179, pp. 231-248.Africa, MoroccoBeniBoussera
DS201412-0221
2014
Bouybaouene, M.El Atrassi, F., Chazot, G., Brunet, F., Chopin, C., Bouybaouene, M.Amphibole genesis in pyroxenites from the Beni Bousera peridotite massif ( Rif, Morocco): evidence for two different metasomatic episodes.Lithos, Vol. 208-209, pp. 67-80.Africa, MoroccoMetasomatism
DS202006-0948
2020
Bouybaouenne, M.Rossetti, F., Lucci, F., Theye, T., Bouybaouenne, M., Gerdes, A., Optiz, J., Dini, A., Lipp, C.Hercynian anatexis in the envelope of the Beni Bousera peridotites ( Alboran Domain, Morroco): implications for the tectono-metamorphic evolution of the deep crustral roots of the Mediterranean region.Gondwana Research, Vol. 83, pp. 157-162. pdfAfrica, Moroccoperidotites

Abstract: The metamorphic core of the Betic-Rif orogenic chain (Alboran Domain) is made up of lower crustal rocks forming the envelope of the Ronda (Spain) and Beni Bousera (Morocco) peridotites. The deepest sections of the crustal envelopes are made of migmatitic granulites associated with diffuse acidic magmatic products, making these exposure and ideal site to investigate the textural and petrological connection between crustal anatexis and granite magmatism in the contintental crust. However, still debated is the timing of intracrustal emplacement of the peridotite bodies, with models proposing either Alpine (early Miocene) or Hercynian ages, and still uncertain is the linkage between peridotite emplacement and crustal anatexis. In this study, by combining rock textures with whole-rock geochemistry, metamorphic thermobarometry, the U-Pb zircon geochronology and the analysis of the garnet and zircon REE chemistry, we document the P-T-t evolution of the granulite facies migmatites that form the immediate envelope of the Beni Bousera peridotites of the Rif belt. A main episode of Permo-Carboniferous (ca. 300-290?Ma) deep crustal anatexis, melt extraction and migration is documented that we link to the crustal emplacement of the Beni Bousera peridotites during collapse of the Hercynian orogen. Correlation at a regional scale suggests that the Beni-Bousera section can be tentatively correlated with the pre-Alpine (Permo-Carboniferous) basement units tectonically interleaved within the orogenic structure of the Alpine chain. The results of this study provide ultimate constraints to reconstruct the tectono-metamorphic evolution of the Alboran Domain in the Western Mediterranean and impose re-assessment of the modes and rates through which Alpine orogenic construction and collapse occurred and operated in the region.
DS201811-2555
2019
Bouyo, M.H.Bouyo, M.H., Penaye, J., Mount, H., Toleu, S.F.Eclogite facies metabasites from the Paleoproterozoic Nyong Group, SW Cameroon: mineralogical evidence and implications for a high pressure metamorphism related to a subduction zone at the NW margin of the Archean Congo craton.Journal of African Earth Sciences, Vol. 149, pp. 215-234.Africa, Cameroonsubduction

Abstract: High- to ultrahigh-pressure metamorphic assemblages consisting of garnet-omphacitic clinopyroxene bearing mafic rocks have been identified within the Paleoproterozoic Nyong Group in SW Cameroon, at the northwestern margin of the Archean Congo craton. These rocks were investigated in detail and for the first time evidence for eclogite facies metamorphism at ca 25?kbar and 850?°C is provided. A clockwise P-T path with nearly isothermal decompression (ITD) is deduced from mineral zoning and textural relationships characterized by mineral recrystallization and multi-layered coronitic overgrowths of plagioclase and clinopyroxene surrounding garnet porphyroblasts. These P-T conditions imply a burial depth greater than 90?km, at lower geothermal gradient of ca 10?°C/km. The geochemical signature of ten representative rock samples show that two groups of eclogite facies rocks genetically originate from mostly basaltic and basaltic andesite compositions, with a characteristic upper mantle-derived tholeiitic trend. Moreover, their chondrite and MORB normalized REE and trace element concentrations are characterized by nearly flat REE patterns with very little to no Eu anomaly, (La/Sm)N???1 and Zr/Nb???10, as well as a gradual depletion from LREE to HREE with also very little to no Eu anomaly, but (La/Sm)N < 1, Zr/Nb > 10 and negative anomalies in Th, K, Nb, Ta, Sr, Zr and Ti consistent with mid-ocean ridge basalt (MORB) contaminated by a subduction component or by a crustal component. Previous available geochronological data coupled with our new petrological, mineralogical and geochemical findings clearly indicate that the eclogite facies metabasites from the Eburnean Nyong Group between 2100 and 2000 Ma represent one of the oldest subducted oceanic slab or trace of a suture zone so far recorded within the West Central African Fold Belt (WCAFB). The geodynamic implications of these eclogites suggest a subduction-related process followed by a rapid exhumation of their protoliths, therefore, providing critical information corroborating that plate tectonic processes operated during the Paleoproterozoic.
DS202007-1122
2020
Bouyon, A.Amsellem, E., Moynier, F., Betrand, H., Bouyon, A., Mata, J., Tappe, S., Day, J.M.D.Calcium isotopic evidence for the mantle source of carbonatites.Science Adavances, Vol. 6, 63 eaba3269 6p. PdfMantlecarbonatite

Abstract: The origin of carbonatites—igneous rocks with more than 50% of carbonate minerals—and whether they originate from a primary mantle source or from recycling of surface materials are still debated. Calcium isotopes have the potential to resolve the origin of carbonatites, since marine carbonates are enriched in the lighter isotopes of Ca compared to the mantle. Here, we report the Ca isotopic compositions for 74 carbonatites and associated silicate rocks from continental and oceanic settings, spanning from 3 billion years ago to the present day, together with O and C isotopic ratios for 37 samples. Calcium-, Mg-, and Fe-rich carbonatites have isotopically lighter Ca than mantle-derived rocks such as basalts and fall within the range of isotopically light Ca from ancient marine carbonates. This signature reflects the composition of the source, which is isotopically light and is consistent with recycling of surface carbonate materials into the mantle.
DS202009-1605
2020
Bouyon, A.Amsellem, E., Moynier, F., Bertrand, H., Bouyon, A., Mata, J., Tappe, S., Day, J.M.D.Calcium isotopic evidence for the mantle sources of carbonatites. ( Oldoinyo Lengai)Science Advances, Vol. 6, eaba3269 June 3, 7p. PdfGlobal, Africa, Tanzaniacarbonatites

Abstract: The origin of carbonatites-igneous rocks with more than 50% of carbonate minerals-and whether they originate from a primary mantle source or from recycling of surface materials are still debated. Calcium isotopes have the potential to resolve the origin of carbonatites, since marine carbonates are enriched in the lighter isotopes of Ca compared to the mantle. Here, we report the Ca isotopic compositions for 74 carbonatites and associated silicate rocks from continental and oceanic settings, spanning from 3 billion years ago to the present day, together with O and C isotopic ratios for 37 samples. Calcium-, Mg-, and Fe-rich carbonatites have isotopically lighter Ca than mantle-derived rocks such as basalts and fall within the range of isotopically light Ca from ancient marine carbonates. This signature reflects the composition of the source, which is isotopically light and is consistent with recycling of surface carbonate materials into the mantle.
DS2000-0125
2000
BouzidiBurwash, R.A., Chacko, Muehlenbachs, BouzidiOxygen isotope systematics of Precambrian basement of Alberta: implications for Paleoproterozoic PhanerozoicCanadian Journal of Earth Sciences, In pressAlberta, Western CanadaTectonics, Geochronology
DS2000-0126
2000
BouzidiBurwash, R.A., Chacko, Muehlenbachs, Bouzidi, SchmittLate orogenic continental growth: examples from Western Canadian lithoprobeGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000 Conference, 2p. abstractAlberta, Cordillera, Western CanadaCraton - orogeny
DS2000-0103
2000
Bouzidi, Y.Bouzidi, Y., Schmitt, Burwash, KanasewichCrustal thickness variations across AlbertaGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000 Conference, 4p. abstractAlbertaGeophysics - seismics, Tectonics
DS2000-0127
2000
Bouzidi, Y.Burwash, R.A., Chacko, T., Muehlenbachs, K., Bouzidi, Y.Oxygen isotope systematics of the Precambrian basement: implications Paleoproterozoic and Phanerozoic tectonicsCanadian Journal of Earth Sciences, Vol.37, No.11, Nov.pp.16011-28.Alberta, northwesternTectonics, Geochronology
DS2002-0195
2002
Bouzidi, Y.Bouzidi, Y., Schmitt, D.R., Burwash, R.A., Kanasewich, E.Depth migration of deep seismic reflection profiles: crustal thickness variations in Alberta.Canadian Journal of Earth Science, Vol.39,3,Mar.pp.331-50., Vol.39,3,Mar.pp.331-50.AlbertaGeophysics - seismics, Mohorovicic Discontinuity, Alberta Basement Transect
DS2002-0196
2002
Bouzidi, Y.Bouzidi, Y., Schmitt, D.R., Burwash, R.A., Kanasewich, E.Depth migration of deep seismic reflection profiles: crustal thickness variations in Alberta.Canadian Journal of Earth Science, Vol.39,3,Mar.pp.331-50., Vol.39,3,Mar.pp.331-50.AlbertaGeophysics - seismics, Mohorovicic Discontinuity, Alberta Basement Transect
DS201312-0044
2013
Bove, M.Ayuso, R., Tucker, R., Peters, S., Foley, N., Jackson, J., Robinson, S., Bove, M.Preliminary radiogenic isotope study on the origin of the Khanneshin carbonatite complex, Helmand Province, Afghanistan.Journal of Geochemical Exploration, Vol. 133, pp. 6-14.AfghanistanCarbonatite
DS1998-0667
1998
BovenIvanov, A.V., Rasskazov, Boven, Andre, Maslovskya, TemuLate Cenozoic alkaline ultrabasic and alkaline basanite magmatism of the Rung we Province, TanzaniaPetrology, Vol. 6, No. 3, June, pp. 208-229.RussiaAlkaline rocks, Brief overview
DS200512-1258
2005
Boven, L.Zheng Fu, G., Hertogen, J., Liu, J., Pasteels, A., Boven, L., Punzalan, H., Xiangiun, L., Zhang, W.Potassic magmatism in western Sichuan and Yunnan Provinces, SE Tibet, China: petrological and geochemical constraints on petrogenesis.Journal of Petrology, Vol. 46, 1, pp. 33-78.China, TibetMagmatism
DS1960-0126
1961
Bovenkerk, H.P.Bovenkerk, H.P.Some Observations on the Morphology and Physical Characteristics of Synthetic Diamond.American MINERALOGIST., Vol. 46, No. 7-8, PP. 952-963.GlobalKimberlite, Synthetic
DS1960-0201
1961
Bovenkerk, H.P.Wentdorf, R.N., Bovenkerk, H.P.On the Origin of Natural DiamondsAstrophysical Journal, Vol. 134, JULY-NOVEMBER PP. 995-1007.ArizonaMeteorite, Canyon Diablo, Terrestrial, Origin, Diamonds
DS1993-0147
1993
Bovenkerk, H.P.Bovenkerk, H.P., et al.Errors in diamond synthesisNature, Vol. 365, No. 6441, September 2, pp. 19-21GlobalDiamond synthesis
DS201212-0659
2012
Bovkin, A.V.Sirotkina, E.A., Bobrov, A.V., Garanin, V.K., Bovkin, A.V., Shkurski, B.B., Korost, D.V.Exsolution textures in majoritic garnets from the Mir kimberlite pipe, Yakutia, Russia.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, YakutiaDeposit - Mir
DS201312-0019
2013
Bovkum, A.V.Anashkin, S.M., Bovkum, A.V., Litvin, Yu.A., Garanin, V.K.the intraplate character of supercontinent tectonics.Doklady Earth Sciences, Vol. 451, 2, pp. 849-854.MantleTectonics
DS201312-0018
2013
Bovkun, A.Anashkin, S., Bovkun, A.,Bindi, L., Garanin, V.,Litvin, Y.Kudryavtsevaite - a new kimberlitic mineral.Mineralogical Magazine, Vol. 77, 3, pp. 327-334.TechnologyMineral chemistry
DS201708-1602
2017
Bovkun, A.Bovkun, A.Features of diamond and its indicator minerals of kimberlites of the M.V. Lomonov deposit, Arkangelsk region, Russia.11th. International Kimberlite Conference, OralRussia, Archangeldeposit - Lomonov
DS1998-0148
1998
Bovkun, A.V.Bovkun, A.V., Garanin, V.K., Kudriavtseva, PossuklovaChemical genetic classification of microcrystalline oxides from kimberlite groundmass - system prospecting7th International Kimberlite Conference Abstract, pp. 91-93.Russia, Arkangelsk, Kola PeninsulaMicroprobe analyses, Deposit - Zolitskoye, Verkhotinskoye, Kepinskoye, Touri
DS1998-0149
1998
Bovkun, A.V.Bovkun, A.V., Garanin, V.K., Kudriavtseva, PossuklovaDiamonds from Timan placers: morphology, spectroscopy and genesis7th International Kimberlite Conference Abstract, pp. 97-99.Russia, TimanPLacers, alluvials, Diamond morphology - types
DS1998-0150
1998
Bovkun, A.V.Bovkun, A.V., Garanin, V.K., Kudriavtseva, PossuklovaChemical genetic classification of oxides from kimberlite groundmass as basis - evaluation of diamond7th International Kimberlite Conference Abstract, pp. 94-96.Russia, Yakutia, AikalHigh magnesian - spinels, Deposit - Obnazhenna, Mir, Udachnaya, Morkokka
DS201112-0970
2011
Bovkun, A.V.Sirotkina, E.A., Bobrov, A.V., Garanin, V.K., Bovkun, A.V., Shkurskii, B.B., Korost, D.V.Pyroxene and olivine exsolution textures in majoritic garnets from the Mir kimberlitic pipe, Yakutia.Goldschmidt Conference 2011, abstract p.1885.RussiaMir
DS201212-0077
2012
Bovkun, A.V.Bobrov, A.V., Sirotkina, E.A., Garanin, V.K., Bovkun, A.V., Korost, D.V., Shkurski, B.B.Majoritic garnets with exsolution textures from the Mir kimberlitic pipe ( Yakutia)Doklady Earth Sciences, Vol. 444, 1, pp. 574-578.Russia, YakutiaDeposit - Mir
DS201212-0084
2012
Bovkun, A.V.Bovkun, A.V., Biller, A.Y., Skvortsova, V.L., Garanin, V.K.Polyphase hydrocarbon inclusions in garnet from the Mir pipe ( Yakutia, Russia).10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, YakutiaDeposit - Mir
DS201212-0229
2012
Bovkun, A.V.Garanin, V.K., Anashkin, S.M., Bovkun, A.V., Jelsma, H., Shmakov, I.I., Garanin, K.V.Groundmass microcrystalline oxides from the Marsfontein pipe ( RSA) , Catoca, Camachia and other Angolan kimberlite pipes.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractAfrica, Angola, South AfricaDeposit - Marsfontein, Catoca, Camachia
DS201212-0733
2012
Bovkun, A.V.Tretyachenko, W., Bovkun, A.V., Garanin, K.V., Garanin, V.K., Tretyachenko, N.G.Formation features of the early Hercynic alkaline ultrabasic and basic volcanic complexes from Zimny Bereg area, north east of Archangelsk region, Russia.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, Archangel, Kola PeninsulaAlkalic
DS201412-0267
2014
Bovkun, A.V.Garanin, V.K., Bovkun, A.V., Garanin, K.V., Kriulina, G.Y., Iwanich, W.Diamonds and its grade in different petrochemical types of kimberlites ( based on Russian diamond deposits).6 Simposio Brasileiro de Geologia do Diamante, Aug. 3-7, 4p. AbstractRussiaMineral chemisty
DS201706-1092
2017
Bovkun, A.V.Litvin, Yu.A., Bovkun, A.V., Androsova, N.A., Garanin, V.K.The system ilmenite-carbonatite-carbon in the origin of diamond: correlation between the titanium content and the diamond potential of kimberlite.Doklady Earth Sciences, Vol. 473, 1, pp. 286-290.Mantlecarbonatite

Abstract: Experimental studies of melting relations in the system ilmenite-K-Na-Mg-Fe-Ca carbonatite-carbon at 8 GPa and 1600°C provide evidence for the effect of liquid immiscibility between ilmenite and carbonatite melts. It is shown that the solubility of ilmenite in carbonatitic melts is negligible and does not depend on its concentration in experimental samples within 25-75 wt %. However, carbonatite-carbon melts are characterized by a high diamond-forming efficiency. This means that the correlation between the concentration of TiO2 and diamond content is problematic for mantle chambers and requires further, more complex, experimental studies.
DS201810-2346
2018
Bovkun, A.V.Litvin, Yu.A., Kuzyura, A.V., Varlamov, D.A., Bovkun, A.V., Spival, A.V., Garanin, V.K.Interaction of kimberlite magma with diamonds upon uplift from the upper mantle to the Earth's crust.Geochemistry International, Vol. 56, 9, pp. 881-900.Russiadeposit - Nyurbinskaya

Abstract: Interaction between a melt of kimberlite from the Nyurbinskaya pipe (Yakutia) and natural monocrystalline diamonds was studied experimentally at 0.15 GPa and 1200-1250°C in high-pressure and high-temperature Ar gas “bombs.” The loss of diamond weight with slight surface dissolution of diamonds in a Ca carbonate-bearing kimberlite melt over the course of 2 h (the period of kimberlite transport from upper-mantle diamond-forming chambers to the crustal cumulative centers) is 3-4.5%. In 4 and 7-8 days (under the conditions of crustal cumulative centers), the weight of diamond decreases with remarkable bulk dissolution by 13.5 and 24.5-27.5%, respectively. In the run at 0.15 GPa and 1200°C kimberlite and ilmenite (added) melts interact to produce perovskite melt. Both of the melts, rich in titanium minerals, are immiscible with kimberlite melt and therefore cannot influence the diamond dissolution kinetics in the kimberlite melt. The experimental results suggest that precisely the dissolution processes for thermodynamically metastable diamonds in silicate-carbonate kimberlitic magmas are responsible for the effective decrease in the diamond potential of kimberlite deposits. The paper discusses the physicochemical reasons for the decrease in the kimberlite diamond potential during the chemically active history of diamond genesis: from upper-mantle chambers to the explosive release of diamonds and kimberlite material from cumulative centers to the Earth’s surface. The data on experimental physicochemical studies of the origin, analytical mineralogy of inclusions, and isotope geochemistry of diamonds are correlated.
DS200612-0158
2005
Bovolo, C.I.Bovolo, C.I.The physical and chemical composition of the lower mantle.Philosophical Transactions of the Royal Society of London Series A Mathematical Physical and Engineering Sciences, Vol. 363, 1837, pp. 2811-2836.MantleGeochemistry
DS200912-0042
2009
BowdenBegg, G.C., Griffin, W.L., Natapov, O'Reilly, Grand, O'Neill, Hronsky, Poudjom Djomeni, Swain, Deen, BowdenThe lithospheric architecture of Africa: seismic tomography, mantle petrology, and tectonic evolution.Geosphere, Vol. 5, pp. 23-50.AfricaGeophysics - seismic, tectonics
DS1960-0221
1962
Bowden, P.Bowden, P.Trace Elements in Tanganyika CarbonatitesNature, Vol. 196, No. 4854, Nov. 10, p. 570.TanzaniaCarbonatite
DS1985-0079
1985
Bowden, P.Bowden, P.The Geochemistry and Mineralization of Alkaline Ring Complexes in Africa- a Review.Journal of AFR. EARTH SCIENCE., Vol. 3, No. 1-2, PP. 17-39.Africa, South AfricaReview
DS1985-0080
1985
Bowden, P.Bowden, P., Martin, R.F.Niger-nigeria Alkaline Ring Complexes: West Africa Representatives of African Phanerozoic Anorogenic Magmatism.Conference Report On A Meeting of Volcanics Studies Group He, 1P. ABSTRACT.Central Africa, NigerPetrogenesis, Geochemistry
DS1989-0155
1989
Bowden, P.Bowden, P.Alkaline magmatism in NamibiaGeological Association of Canada (GAC) Annual Meeting Program Abstracts, Vol. 14, p. A50. (abstract.)Southwest Africa, NamibiaBlank
DS1991-0871
1991
Bowden, P.Kinnard, J.A., Bowden, P.Magmatism and mineralization associated with Phanerozoic an orogenic plutonic complexes of the African Plate.Magmatism in Extensional structural settings, Springer pp. 410-485.AfricaTectonics, Alkaline magmatism
DS1995-1393
1995
Bowden, P.Onuong, I.O., Bowden, P., Fallick, A.F.Carbon, oxygen and sulphur isotope investigations at Buru and Kuge volcanic carbonatite centres, Nyanza RiftGeological Society Africa 10th. Conference Oct. Nairobi, p. 124-5. Abstract.KenyaGeochronology, carbonatite, Deposit -Buru, Kuge
DS1995-1394
1995
Bowden, P.Onuonga, I.O., Bowden, P.Lanthanide mineralization in volcanic carbonatites western KenyaGeological Society Africa 10th. Conference Oct. Nairobi, p. 131. Abstract.KenyaCarbonatite, rare earths, Deposit -Ruri, Rangwa, Kuge, Buru, Koru
DS1997-0876
1997
Bowden, P.Onuonga, I.O., Fallick, A.E., Bowden, P.The recognition of meteoric hydrothermal and supergene processes in volcanic carbonatites, Nyanza Rift...Journal of African Earth Sciences, Vol. 25, No. 1, July pp. 103-114.KenyaCarbonatite, Geochronology
DS1999-0481
1999
Bowden, P.Mirnejad, H., Bowden, P.Strontium, neodymium, and lead isotopic systematics of lamproites from the Leucite Hills, Wyoming, USAStanley, SGA Fifth Biennial Symposium, pp. 655-8.WyomingLamproites, Deposit - Leucite Hills
DS1999-0526
1999
Bowden, P.Onuonga, I.O., Bowden, P.Lanthanide mineralization associated with Kuge carbonatite centre, westernkenya.Stanley, SGA Fifth Biennial Symposium, pp. 659-62.KenyaCarbonatite
DS2000-0731
2000
Bowden, P.Ononga, L.O., Bowden, P.Hot spring and supergene lanthanide mineralization at the Baru carbonatitecentre, western Kenya.Mineralogical Magazine, Vol. 64, No. 4, Aug. 1, pp.633-40.KenyaCarbonatite
DS2000-0734
2000
Bowden, P.Onuonga, I.O., Bowden, P.Hot spring and supergene lanthanide mineralization at the Buru carbonatitecentre, Western Kenya.Mineralogical Magazine, Vol. 64, No. 4, Aug. pp. 663-74.KenyaCarbonatite, Deposit - Buru
DS2000-0875
2000
Bowden, P.Schurmann, L., Wall, F., Bowden, P.Processes in high level carbonatite magma chambers: evidence from Nooitgedacht, South Africa.Igc 30th. Brasil, Aug. abstract only 1p.South AfricaCarbonatite, Deposit - Nooitgedacht
DS2001-0154
2001
Bowden, P.Calder. A., Bowden, P.X ray monitored mineralogical changes in surface exposures of natrocarbonatite lava.Journal of South African Earth Sciences, Vol. 32, No. 1, p. A 12 (abs)TanzaniaCarbonatite, Oldoinyo Lengai
DS2001-0244
2001
Bowden, P.Delpech, G., Bowden, P.Morphological modifications to the active carbonatite crater: differences between Oct. 1995- August 1999.Journal of South African Earth Sciences, Vol. 32, No. 1, p. A 14 (abs)TanzaniaCarbonatite, Oldoinyo Lengai
DS201909-2062
2019
Bowden, R.Mikhail, S., McCubbin, F.M., Jenner, F.E., Shirey, S.B., Rumble, D., Bowden, R.Diamonites: evidence for a distinct tectono-thermal diamond - forming event beneath the Kaapvaal craton.Contributions to Mineralogy and Petrology, in press available, 15p. PdfAfrica, South Africadiamondite
DS2001-0130
2001
Bowden. P.Bowden. P., Wall, F., Schurmann, L.Spinifex textured pegmatitic crystallization in carbonatitesJournal of South African Earth Sciences, Vol. 32, No. 1, p. A 11 (abs)TanzaniaCarbonatite, Kerimasi Volcano
DS200912-0065
2009
Bowen, D.C.Bowen, D.C., Ferraris, R.D., Palmer, C.E., Ward, J.D.On the unusual characteristics of the diamonds from Letseng La Terae kimberlites, Lesotho.Lithos, In press available 25p.Africa, LesothoDeposit - Letseng La Terae
DS201412-0967
2014
Bowen, D.C.Ward, J.D., Bowen, D.C., Fourie, P., Ntsalong, L.The Kao kimberlite, Lesotho: main pipe - main mine?GSSA Kimberley Diamond Symposium and Trade Show provisional programme, Sept. 12, title onlyAfrica, LesothoDeposit - Kao
DS1920-0099
1922
Bowen, N.L.Bowen, N.L.Genetic Features of Alnoitic Rocks at Isle Cadieux, QuebecAmerican Journal of Science, 5TH. SER., Vol. 3, PP. 1-34.Canada, QuebecPetrogenesis, Petrography, Alnoite, Related Rocks
DS1920-0183
1924
Bowen, N.L.Bowen, N.L.The Fen Area in Telemark, NorwayAmerican Journal of SCIENCE., Vol. 8, PP. 1-11.Norway, ScandinaviaUltramafic And Related Rocks
DS1920-0275
1926
Bowen, N.L.Bowen, N.L.Die Carbonatgesteine des Fengebietes in NorwegenCentralblatt F. Min., SER. A, No. 8, PP. 241-245.Norway, ScandinaviaCarbonatite, Ultramafic And Related Rocks
DS1920-0276
1926
Bowen, N.L.Bowen, N.L.The Carbonate Rocks of the Fen Area of NorwayAmerican Journal of SCIENCE., Vol. 12, PP. 499-502.Norway, ScandinaviaUltramafic And Related Rocks
DS1987-0071
1987
Bowen, R.L.Bowen, R.L.Impact of pleistocene processes in exploration strategies foroffshoreplacersNineteenth Annual Offshore Technology Conference held Houseton, April 27-30, Vol. 19, pp. 459-463GlobalPlacers, Geological methods, techni
DS201112-0145
2011
Bower, D.Carmody, L., Jones, A.P., Kilburn, C., Steele, A., Bower, D.A first Raman study of fluid inclusions within xenoliths from Oldoinyo Lengai, Tanzania.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterAfrica, TanzaniaCarbonatite
DS201112-0146
2011
Bower, D.Carmody, L., Jones, A.P., Kilburn, C., Steele, A., Bower, D.A first Raman study of fluid inclusions within xenoliths from Oldoinyo Lengai, Tanzania.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.15-16.Africa, TanzaniaCarbonatite
DS201112-0147
2011
Bower, D.Carmody, L., Jones, A.P., Kilburn, C., Steele, A., Bower, D.A first Raman study of fluid inclusions within xenoliths from Oldoinyo Lengai, Tanzania.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.15-16.Africa, TanzaniaCarbonatite
DS201508-0357
2015
Bower, D.J.Hassan, R., Flament, N., Gurnis, M., Bower, D.J., Muller, D.Provenance of plumes in global convection models.Geochemistry, Geophysics, Geosystems: G3, Vol. 16, 5m pp. 1465-1489.AfricaConvection
DS201904-0771
2019
Bower, D.J.Reali, R., Jackson, J.M., Van Orman, J., Bower, D.J., Carrez, P., Cordier, P.Modeling viscosity of ( Mg, Fe)O at lowermost mantle conditions.Physics of the Earth and Planetary Interiors, Vol. 287, pp. 65-75.Mantlecore-mantle boundary

Abstract: The viscosity of the lower mantle results from the rheological behavior of its two main constituent minerals, aluminous (Mg,Fe)SiO3 bridgmanite and (Mg,Fe)O ferropericlase. Understanding the transport properties of lower mantle aggregates is of primary importance in geophysics and it is a challenging task, due to the extreme time-varying conditions to which such aggregates are subjected. In particular, viscosity is a crucial transport property that can vary over several orders of magnitude. It thus has a first-order control on the structure and dynamics of the mantle. Here we focus on the creep behavior of (Mg,Fe)O at the bottom of the lower mantle, where the presence of thermo-chemical anomalies such as ultralow-velocity zones (ULVZ) may significantly alter the viscosity contrast characterizing this region. Two different iron concentrations of (Mg1-xFex)O are considered: one mirroring the average composition of ferropericlase throughout most of the lower mantle (x?=?0.20) and another representing a candidate magnesiowüstite component of ULVZs near the base of the mantle (x?=?0.84). The investigated pressure-temperature conditions span from 120?GPa and 2800?K, corresponding to the average geotherm at this depth, to core-mantle boundary conditions of 135?GPa and 3800?K. In this study, dislocation creep of (Mg,Fe)O is investigated by dislocation dynamics (DD) simulations, a modeling tool which considers the collective motion and interactions of dislocations. To model their behavior, a 2.5 dimensional dislocation dynamics approach is employed. Within this method, both glide and climb mechanisms can be taken into account, and the interplay of these features results in a steady-state condition. This allows the retrieval of the creep strain rates at different temperatures, pressures, applied stresses and iron concentrations across the (Mg,Fe)O solid solution, providing information on the viscosity for these materials. A particularly low viscosity is obtained for magnesiowüstite with respect to ferropericlase, the difference being around 10 orders of magnitude. Thus, the final section of this work is devoted to the assessment of the dynamic implications of such a weak phase within ULVZs, in terms of the viscosity contrast with respect to the surrounding lowermost mantle.
DS201906-1327
2019
Bower, D.J.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
Bower, D.J.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.
DS201312-0126
2012
Bower, D.M.Carmody, L., Jones, A.P., Mikhail, S., Bower, D.M., Steele, A., Lawrence, D.M., Verchovsky, A.B., Buikin, A., Taylor, L.A.Is the World's only carbonatite volcano a dry anhydrous system?Geological Society of America Annual Meeting abstract, Paper 157-2, 1/2p. AbstractAfrica, TanzaniaDeposit - Oldoinyo Lengai
DS1950-0472
1959
Bower, M.E.Garland, G.D., Bower, M.E.Interpretation of Aeromagnetic Anomalies in Northeastern AlbertaFifth World Petroleum Congress, pp. 787-800.AlbertaGeophysics - Magnetics
DS1997-0119
1997
Bower, S.M.Bower, S.M., Woods, A.W.Control of magma volatile content and chamber depth on the mass erupted during explosive volcanic eruptions.Journal of Geophysical Research, Vol. 102, No. 5, May 10, pp. 10273-Mantlevolcanism., Magma - geodynamics
DS200412-0176
2004
Bowerman, M.S.Bohm, C.O., Bowerman, M.S.Superior margin program news. (Gull Rapids area mentions... dykes .. potential for kimberlites)Manitoba Geological Survey, Report of Activities Nov. 18-20, abstractCanada, ManitobaTectonics
DS201412-0063
2014
Bowers, D.Bowers, D.Alexkor diamond mine turnaround strategy - the importance of sound geological models and mineral resouce management.GSSA Kimberley Diamond Symposium and Trade Show provisional programme, Sept. 10-12, POSTERAfrica, South AfricaDeposit - Alexkor
DS1993-0648
1993
Bowers, M.T.Helden, G. von, Gotts, N.G., Bowers, M.T.Experimental evidence for the formation of fullerenes by collisional heating of carbon rings in the gas phaseNature, Vol. 363, No. 6424, May 6, pp. 60-63GlobalCVD.
DS200612-0839
2006
Bowers, S.Ludascher, B., Lin, K., Bowers, S., Jaeger-Frank, E., Brodaric, B., Baru, C.Managing scientific dat a: from dat a integration to scientific workflows.In: Sinha, A.K. Geoinformatics: data to knowledge, GSA Special Paper, 397, 397,pp.109-30TechnologyData - not specific to diamonds
DS200612-1500
2006
Bowers, T.D.Walker, J.D., Bowers, T.D., Black, R.A., Glazner, A.F., Farmer, G.L., Carlson, R.W.A geochemical database for western North American volcanic and intrusive rocks. NAVDATIn: Sinha, A.K. Geoinformatics: data to knowledge, GSA Special Paper, 397, 397, pp.61-72United StatesGeochemistry - data
DS1995-1615
1995
Bowers, T.L.Rowan, L.C., Bowers, T.L., Crowley, J.K., et al.Analysis of airborne visible infrared imaging spectrometer (AVIRIS) dat a Of the Iron Hill carbonatiteEconomic Geology, Vol. 90, No. 7, Nov. pp. 1966-1982.ColoradoCarbonatite, remote sensing, Deposit -Iron Hill
DS201811-2556
2015
Bowersox, G.Bowersox, G.The emerald minerals of Panjshir Valley, Afganistan.InColor, December pp. 70-77.Asia, Afghanistanemeralds

Abstract: With the withdrawal of Soviet troops from Afghanistan, villagers in the Pani- & shir Valley are Lurning their attention to the emerald riches of the nearby Hindu Kush Mountains. Large, dark green crystals have been found in the hundreds of tunnels and shafts dug there. Teams of miners use explosives and drills to remove the limestone that hosts the emerald-bearing quartz and onkerite veins. The gemological properties of Panjshir emeralds are consisrent with those of emeralds from other localities; chemically, they are most similar to emeralds from the Muzo mine in Colombia. "Nodules," previously reported only in tourmaline and morganite, have been found in Panjshir emeralds as well. Approximntely $1 0 million in emeralds were produced in 1990; future prospects ore excellent.
DS1993-1093
1993
BowesMueller, P.A., Shuster, R.D., Wooden, J.L., Ersley, E.A., BowesAge and composition of Archean crystalline rocks from the southern MadisonGeological Society of America Bulletin, Vol. 105, No. 4, April pp. 437-446.MontanaTectonics, Geochronology, Wyoming Craton
DS1960-0413
1963
Bowes, D.R.Wright, A.E., Bowes, D.R.Classification of Volcanic Breccia: a DiscussionGeological Society of America (GSA) Bulletin., Vol. 74, PP. 79-86.GlobalBreccia
DS1990-1251
1990
Bowes, D.R.Rock, N.M.S., Wright, A.E., Bowes, D.R.Lamprophyres - plutonic and volcanic equivalents of lamprophyresVan Nostrand Reinhold, Chapter 7 pp. 113-124GlobalLamprophyres (melilitolites, ankaratrites, katungites, Appinite, vaugnerite, calc-alkaline, minette, melilitites
DS1995-0820
1995
Bowes, D.R.Hopggod, A.M., Bowes, D.R., Tonika, J.Application of structural sucession to characterization of the Bohemian Forest tectonic domain... Hercynides.Neues Jahrbuch f?r Mineralogie Abh, Vol. 169, No. 2, pp. 119-156GlobalStructure, Tectonics
DS1995-0821
1995
Bowes, D.R.Hopgood, A.M., Bowes, D.R.Matching Gondwanaland fragments: the significance of granitoid veins and tectonic structures in southwest AustraliaJournal of Southeast Asian Earth Sciences, Vol. 11, No. 3, pp. 253-263AustraliaGondwanaland, Tectonics
DS200912-0066
2009
Bowes-Lyon, M.C.Bowes-Lyon, M.C., Richards, J.P., McGee, T.M.Socio-economic impacts of the Nanisivik and Polaris mines, Nunavut, Canada.Springer Richards, J.P.Editor Mining Society and a sustainable world, 36p. preprintCanada, NunavutCSR - not specific to diamonds
DS1994-0195
1994
Bowie, C.Bowie, C.Selected geoscience dat a for Slave Province NATMAP, bedrock geologyPaul, Winter, High, Koala, UrsulaGeological Survey of Canada, CD ROM 2974 approx. $ 200.00Northwest TerritoriesBedrock, surficial, geomorphology, CD ROM digital data
DS1994-0196
1994
Bowie, C.Bowie, C.Cartographic overlay of geology Slave -Craton and environs on shaded total field magnetic data.Geological Survey of Canada Open file Map., No. 2964, 1: 1 million $ 19.75Northwest TerritoriesGeology map
DS1994-0197
1994
Bowie, C.Bowie, C.Slave NATMAP: digital release of preliminary datasets on CD-ROM mediaNorthwest Territories 1994 Open House Abstracts, p. 25. abstractNorthwest TerritoriesNews item, NATMAP -Slave
DS1994-0198
1994
Bowie, C.Bowie, C., Kjarsgaard, B.A.Ultilization of GIS technology for the exploration of kimberlite pipes, Lacde Gras.Northwest Territories 1994 Open House Abstracts, p. 25-26. abstractNorthwest TerritoriesNews item, GIS
DS1994-0199
1994
Bowie, C.Bowie, C., Kjarsgaard, B.A., Wyllie, R.J.S.Utilization of GIS technology for the exploration of kimberlite deposits, Lac de Gras area, Slave Province, Northwest Territories.Geological Survey of Canada Open Forum January 17-19th. Abstracts only, p. 11.Northwest TerritoriesGIS, Kimberlite
DS1994-0493
1994
Bowie, C.Epp. H., Bowie, C.Utilization of remote sensing and GIS technology for the exploration Of kimberlite pipes, Lac de Gras.Northwest Territories 1994 Open House Abstracts, p. 29. abstractNorthwest TerritoriesNews item, Remote Sensing
DS1996-0161
1996
Bowie, C.Bowie, C., Kjarsgaard, B.A.GIS methodology for assessing the influence of Proterozoic diabase dike swarms on the distribution...northwest Territories Exploration overview 1995, March pp. 3-5. abstractNorthwest TerritoriesDiabase dike, Lac de Gras area
DS1996-0162
1996
Bowie, C.Bowie, C., Kjarsgaard, B.A.GIS methodology for assessing the influence of local structural controls on the distribution and emplacementGeological Association of Canada (GAC) Annual Abstracts, Vol. 21, abstract only p.A11.Northwest TerritoriesKimberlite pipes, Lac de Gras area
DS1996-0163
1996
Bowie, C.Bowie, C., Kjarsgaard, B.A., Broome, H.J., Rencz, A.N.GIS activities related to diamond research and exploration Lac de Grasarea, northwest Territories.Geological Survey of Canada, LeCheminant ed, OF 3228, pp. 259-263.Northwest TerritoriesGIS - digital database, Overview
DS1996-1176
1996
Bowie, C.Rencz, A.N., Bowie, C., Ward, B.C.Application of thermal imagery from Land sat dat a to locate kimberlites, Lacde Gras area, northwest Territories.Geological Survey of Canada, LeCheminant ed, OF 3228, pp. 255-257.Northwest TerritoriesLandsat Thematic Mapper data, Lac de Gras area
DS1998-1580
1998
Bowie, C.Wilkinson, L., Harris, J., Kjarsgaard, B., Bowie, C.Preliminary weights of evidence modeling of kimberlite distributions in the Lac de Gras area, using GIS tech.Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) Abstract Volume, p. A198. abstract.Northwest TerritoriesComputer - GIS, Geochemistry, geophysics - magnetics
DS1990-0681
1990
Bowins, R.Heaman, L.M., Bowins, R., Crocket, J.The chemical composition of igneous zircon suites: implications for geochemical tracer studiesGeochimica et Cosmochimica Acta, Vol. 54, pp. 1597-1607South Africa, OntarioKimberlites, Carbonatite, Geochemistry -zircon
DS1996-1135
1996
Bowles, J.F.Potts, P.J., Bowles, J.F., Reed, S.J.B., Cave, M.R.Microprobe techniques in the earth sciencesChapman Hall, MSA., MSA No. 6, 420p. approx. 80.00 United StatesGlobalBook - table of contents, Microprobe techniques, review
DS1996-1136
1996
Bowles, J.F.W.Potts, P.J., Bowles, J.F.W., Reed, S.J.B., Cave, M.R.Microprobe techniques in the earth sciencesMineralogical Soc. Series, No. 6, 410p. approx. $60.00USGlobalMicroprobe techniques, Various chapters techniques - not specific to diamond
DS1987-0072
1987
Bowley, H.J.Bowley, H.J., Gerrard, D.L.Method for assessing diamond qualityPatent PCT International Appl. 87 03963 Al *July 2, 1987, GlobalRaman spectrometry
DS1988-0074
1988
Bowley, H.J.Bowley, H.J., Gerrard, D.L.Methods and apparatus for determining the color type of diamondsBp Patent Pct International Appl. 88 05534 A1, July 28, GlobalRaman diamond color type determination, Diamond morphology -colou
DS1999-0294
1999
Bowling, J.C.Harry, D.L., Bowling, J.C.Inhibiting magmatism on nonvolcanic rifted marginsGeology, Vol. 27, No. 10, Oct. pp. 895-8.MantleMelting, Magmatism
DS201412-0028
2013
Bowling, S.A.Ault, A.K., Flowers, R.M., Bowling, S.A.Phanerozoic surface history of the Slave craton.Tectonics, Vol. 32, 5, pp. 1066-1083.Canada, Northwest TerritoriesGeodynamics
DS201501-0003
2015
Bowlring, S.A.Ault, A.K., Flowers, R.M., Bowlring, S.A.Synchroneity of cratonic burial phases and gaps in kimberlite record: episodic magmatism or preservational bias?Earth and Planetary Science Letters, Vol. 410, pp. 97-104.Global, CanadaThermochronology - Slave craton

Abstract: A variety of models are used to explain an apparent episodicity in kimberlite emplacement. Implicit in these models is the assumption that the preserved kimberlite record is largely complete. However, some cratons now mostly devoid of Phanerozoic cover underwent substantial Phanerozoic burial and erosion episodes that should be considered when evaluating models for global kimberlite distributions. Here we show a broad temporal coincidence between regional burial phases inferred from thermochronology and gaps in the kimberlite record in the Slave craton, Superior craton, and cratonic western Australia. A similar pattern exists in the Kaapvaal craton, although its magmatic, deposition, and erosion history differs in key ways from the other localities. One explanation for these observations is that there is a common cause of cratonic subsidence and suppression of kimberlite magmatism. Another possibility is that some apparent gaps in kimberlite magmatism are preservational artifacts. Even if kimberlites occurred during cratonic burial phases, the largest uppermost portions of the pipes would have been subsequently eroded along with the sedimentary rocks into which they were emplaced. In this model, kimberlite magmatism was more continuous than the preserved record suggests, implying that evidence for episodicity in kimberlite genesis should be carefully evaluated in light of potential preservational bias effects. Either way, the correlation between burial and kimberlite gaps suggests that cratonic surface histories are important for understanding global kimberlite patterns.
DS1900-0015
1900
Bowman, H.L.Bowman, H.L.On a Rhombic Pyroxene from South AfricaMineralogical Magazine., VOL 12, NOVEMBER PP. 349-353.Africa, South AfricaMineralogy
DS1988-0075
1988
Bowman, J.R.Bowman, J.R.The use of closely spaced receiver arrays to delineate the structure of The upper mantle under northernAustraliaExploration Geophysics, Abstract volume, Vol. 19, No. 1-2, Mar-June pp. 25-28AustraliaMantle, Geophysics
DS1990-0229
1990
Bowman, J.R.Bowman, J.R., Kennett, B.L.N.An investigation of the upper mantle beneath northwest Australia using a hybridseismographarrayGeophys. Journal of International, Vol. 101, No. 2, pp. 395-410AustraliaMantle, Geophysics -seismics
DS1993-0345
1993
Bowman, J.R.Dey, S.C., Kennett, B.L.N., Bowman, J.R., Goody, A.Variations in upper mantle structure under northern AustraliaGeophysical Journal International, Vol. 114, pp. 304-310AustraliaGeophysics - seismics
DS200812-0132
2008
Bowman, J.R.Bowman, J.R., Moser, D.E., Wooden, J.L., Valley, J.W., Mazdab, F.K., Kita, N.Cathodluminescence CL isotopic Pb O and trace element zoning in lower crustal zircon documents growth of early continental lithosphere.Goldschmidt Conference 2008, Abstract p.A107.Canada, OntarioKapuskasing Uplift
DS200812-0767
2008
Bowman, J.R.Moser, D.E., Bowman, J.R., Wooden, J., Valley, J.W., Mazdab, F., Kita, N.Creation of a continent recorded in zircon zoning.Geology, Vol. 36, 3 March pp. 239-242.Canada, OntarioGeochronology - Kapuskasing
DS1975-0700
1978
Bowman, P.L.Bowman, P.L.Correlation of Gravity and Magnetic Dat a Over Central Northamerica.Msc. Thesis, Purdue University, GlobalMid-continent
DS1975-0956
1979
Bowman, P.L.Bowman, P.L., Hinze, W.J., Chandler, V.W.Long Wavelength Gravity and Magnetic Anomalies of the Lake Superior Region.Geological Society of America (GSA), Vol. 11, No. 5, P. 226. (abstract.).GlobalMid-continent
DS1995-0188
1995
Bown, J.W.Bown, J.W., White R.S.Effect of finite extension rate on melt generation at rifted continentalmarginsJournal of Geophysical Research, Vol. 100, No. 9, Sept. 10, pp. 8011-8044MantleTectonics, Rifting, margins
DS1996-0164
1996
Bowrimg, S.A.Bowrimg, S.A., et al.Thermochronology of Proterozoic middle crust southwest United States: implications for models of lithospheric evolution.Geological Society of America, Abstracts, Vol. 28, No. 7, p. A-452.Arizona, New MexicoGeothermometry
DS2001-0720
2001
BowringMajaule, T., Hanson, Key, Singletary, Martin, BowringThe Magondi belt in northeast Botswana: regional relations and new geochronological dat a from Sua PanJournal of African Earth Sciences, Vol. 32, No. 2, pp. 257-67.BotswanaOrogeny, Geochronology - mentions diamond area
DS2001-1203
2001
BowringVinyu, M.L., Hanson, R.E., Martin, M.W., Bowringuranium-lead (U-Pb) zircon ages from craton margin Archean orogenic belt in northern Zimbabwe.Journal of African Earth Sciences, Vol. 32, No. 1, Jan. pp. 103-114.ZimbabweCraton, Geochronology
DS2002-0652
2002
BowringHanson, R., Pancake, J., Crowley, J., Ramezani, Bowring, Dalziel, GoseCorrelation of 1.1 GA large igneous provinces on the Laurentia and Kalahari Cratons:Geological Society of America Annual Meeting Oct. 27-30, Abstract p. 561.South Africa, Botswana, Zimbabwe, OntarioTectonics, Gondwana
DS1991-1460
1991
Bowring, R.D.Ross, G.M., Parrish, R.R., Villeneuve, M.E., Bowring, R.D.Geophysics and geochronology of the crystalline basement of the AlbertaBasin, western CanadaCanadian Journal of Earth Sciences, Vol. 28, No. 4, April pp. 512-522AlbertaGeophysics -magnetics, Basement tectonics, Geochronology
DS1989-1305
1989
Bowring, S.Ross, G.M., Villeneuve, M.E., Parrish, R.R., Bowring, S.Tectonic subdivision and uranium-lead (U-Pb) geochronology of the Precambrian basement Alberta Basin, Western Canada.Geological Survey of Canada (GSC) Open file, No. 2103, 1:1, 000, 000Alberta, CordilleraGeochronology, Tectonics
DS1992-0661
1992
Bowring, S.Hanmer, S., Bowring, S., Van Breemen, O., Parrish, R.Great Slave Lake shear zone, northwest Canada: mylonitic record of early Proterozoic continental convergence, collision and indentationJournal of Structural Geology, Vol. 14, No. 7, pp. 757-773Northwest TerritoriesStructure Tectonics, Shear zone
DS1998-0330
1998
Bowring, S.De Wit, M.J., Ghosh, J.G., Bowring, S., Ashwal, L.Late Neoproterozoic shear zones in Madagascar and India: Gondwana"life-lines".Journal of African Earth Sciences, Vol. 27, 1A, p. 58. AbstractAfrica, Madagascar, IndiaGondwana, Tectonics
DS2000-0282
2000
Bowring, S.Farmer, G.L., Letser, A.C., Bowring, S., Matzel, J.Composition of the lower continental crust beneath the Cheyenne Belt S. WyoGeological Society of America (GSA) Abstracts, Vol. 32, No. 7, p.A-386.Wyoming, ColoradoGeochronology - isotopic evidence, Xenoliths - mafic
DS2000-0635
2000
Bowring, S.Matzel, J., Bowring, S., Stevns, L., Williams, M.I.Geochronology of lower crustal xenoliths from across the State Line Belt, S. Wyoming and N. Colorado.Geological Society of America (GSA) Abstracts, Vol. 32, No. 7, p.A-387.Wyoming, ColoradoGeochronology, Deposit - Leucite Hills, State Line
DS2001-1033
2001
Bowring, S.Schmitz, M., Bowring, S.Constraints on southern African lithospheric thermal evolution from uranium-lead (U-Pb) rutile titanite thermochronologySlave-Kaapvaal Workshop, Sept. Ottawa, 3p. abstractSouth Africa, LesothoXenoliths - lower crustal, Deposit - Newlands
DS2002-0857
2002
Bowring, S.Kiykawa, S., Taira, A., Byrne, T., Bowring, S., Sano, Y.Structural evolution of the middle Archean coastal Pilbara terrane, western AustraliaTectonics, Vol. 21, No. 5, 10.1029/2001TC001296.AustraliaTectonics - structure
DS200812-1024
2008
Bowring, S.Schoene, B., De Wit, M.J., Bowring, S.Mesoarchean assembly and stabilization of the eastern Kaapvaal craton: a structural thermochronology perspective.Tectonics, Vol. 27, TC5010.Africa, South AfricaGeothermometry
DS200912-0676
2009
Bowring, S.Schoene, B., Dudas, F.O.L., Bowring, S., De Wit, M.Sm Nd isotopic mapping of lithospheric growth and stabilization in the eastern Kaapvaal craton.Terra Nova, Vol. 21, 3, pp. 219-228.Africa, South AfricaGeochronology
DS201012-0629
2010
Bowring, S.Rioux, M.,Bowring, S., Dudas, F., Hanson, R.Characterizing the U-Pb systematics of baddeleyite through chemical abrasion: application of multi-step digestion methods to baddelyite geochronology.Contributions to Mineralogy and Petrology, in press available 25p.Africa, South AfricaCarbonatite, Phalaborwa
DS201112-0090
2011
Bowring, S.Blackburn, T., Bowring, S., Perron, T., Mahan, K., Dudas, F.A long term record of continental lithosphere exhumation via U-Pb thermochronology of the lower crust.Goldschmidt Conference 2011, abstract p.532.United States, MontanaCraton, keels
DS201412-0064
2014
Bowring, S.Bowring, S.Early Earth: closing the gapNature Geoscience, Vol. 7, pp. 169-170.MantleGeochronology
DS1984-0166
1984
Bowring, S.A.Bowring, S.A., Van schmus, W.R., Hoffman, P.F.uranium-lead (U-Pb) zircon ages from Athapuscow aulacogen, East Arm of Great Slave @northwest Territories.Canadian Journal of Earth Sciences, Vol. 21, pp. 1315-24.Northwest TerritoriesGeochronology, Alkaline Rocks
DS1987-0288
1987
Bowring, S.A.Heatherington, A., Bowring, S.A., Luhr, J.Petrogenesis of calc-alkaline and alkaline volcanics from the western Mexican volcanic belt PB-isotopesGeological Society of America, Vol. 19, No. 7 annual meeting abstracts, p.698. abstracMexicoMinette
DS1988-0076
1988
Bowring, S.A.Bowring, S.A., Arvidson, R.A., Podosek, F.A.The Missouri gravity low: evidence for a cryptic suture?Geological Society of America Abstracts with Program, Vol. 20, No. 2, January p. 91. Sth. Central, LawrenceMissouriBlank
DS1989-0156
1989
Bowring, S.A.Bowring, S.A., King, J.E., Housh, T.B., Isachsen, C.E., Podosek, F.A.Neodymium and lead isotope evidence for enriched early Archean crust in North AmericaNature, Vol. 340, No. 6230, July 20, pp. 222-224North AmericaGeochronology, Archean
DS1989-0157
1989
Bowring, S.A.Bowring, S.A., Podosek, F.A.neodymium isotope evidence from Wopmay Orogen for 2.0-2.4 Gacrust in Western north AmericaEarth and Planetary Science Letters, Vol. 94, pp. 217-230. Database # 18132Northwest TerritoriesOrogeny -Wopmay, Geochronology
DS1989-0158
1989
Bowring, S.A.Bowring, S.A., Wiliams, I.S., Compston, W.3.96 Ga gneises from the Slave Province, Northwest Territories, canadaGeology, Vol. 17, No. 11, Nov. pp. 971-75.Northwest TerritoriesGeochronology, Archean rocks
DS1989-0666
1989
Bowring, S.A.Housh, T., Bowring, S.A., Villeneuve, M.Lead isotopic study of Early Proterozoic Wopmay Orogen, northwest Canada: role of continental crust in arc magmatismJournal of Geology, Vol. 97, No. 6, November pp. 735-748Northwest TerritoriesGeochronology, Orogeny -Wopmay
DS1990-0230
1990
Bowring, S.A.Bowring, S.A., Karlstrom, K.E.Growth, stabillization and reactivation of Proterozoic lithosphere in The southwestern United StatesGeology, Vol. 18, No. 12, December pp. 1203-1206Colorado Plateau, Arizona, New MexicoMantle, Tectonics
DS1992-0153
1992
Bowring, S.A.Bowring, S.A.Earth's early crustEos Transactions, Vol. 73, No. 3, Jan. 21, p. 33MantleCrust, Geochemistry
DS1992-0154
1992
Bowring, S.A.Bowring, S.A., Grotzinger, J.P.Implications of new chronostratigraphy for tectonic evolution of Wopmayorogen, northwest Canadian ShieldAmerican Journal of Science, Vol. 292, January pp. 1-20Northwest TerritoriesGeochronology, Wopmay Orogen
DS1992-0642
1992
Bowring, S.A.Haas, J.R., Haskin, L.A., Luhr, J.F., Bowring, S.A., Rasskazov, S.Y.Petrogenesis of quaternary basinites from the Bartoy Volcanic Field of the Baikal Rift Zone, Siberia, RussiaEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p.334Russia, Siberia, RussiaBasinite, Baikal Rift Zone
DS1993-0148
1993
Bowring, S.A.Bowring, S.A., Housh, T.B., Isachsen, Hilebrand, R.S.What do we know about the western limit of the Slave craton?Northwest Territories Exploration Overview for 1993, November p. 24.Northwest TerritoriesCraton, Slave Craton
DS1994-0200
1994
Bowring, S.A.Bowring, S.A., Karlstrom, K.E.Thermochronologic constraints on Proterozoic lithospheric evolution, southwestern U.S.Geological Society of America Abstracts, Vol. 26, No. 6, April p. 6. Abstract.New MexicoGeochronology, Tectonics
DS1994-0811
1994
Bowring, S.A.Isachsen, C.E., Bowring, S.A.Evolution of the Slave CratonGeology, Vol. 22, No. 10, October pp. 917-920Northwest TerritoriesTectonics, Slave craton
DS1994-0812
1994
Bowring, S.A.Isachsen, C.E., Bowring, S.A.Evolution of the Slave cratonGeology, Vol. 22, No. 10, October pp. 917-920.Northwest TerritoriesTectonics, Slave craton
DS1995-0189
1995
Bowring, S.A.Bowring, S.A.Crustal growth and preservation.Eos, Abstracts, Vol. 76, No. 17, Apr 25, p. S 294.Mantle, crustTectonics
DS1995-0190
1995
Bowring, S.A.Bowring, S.A., Houash, T.The earth's early evolutionScience, Vol. 269, No. 5320, Sept. 15, pp. 1535-1540GlobalDynamics, Tectonics
DS1995-0191
1995
Bowring, S.A.Bowring, S.A., Housh, T.The earth's early evolutionScience, Vol. 269, No. 5230, Sept. 15, pp. 1535-1540.GlobalCrustal evolution, Craton
DS1995-0855
1995
Bowring, S.A.Isachsen, C.E., Bowring, S.A.Archean arc-continent collision in Slave structural province or not?Eos, Vol. 76, No. 46, Nov. 7. p.F602. Abstract.Northwest TerritoriesTectonics, Crust -geodynamics
DS1997-0544
1997
Bowring, S.A.Isachsen, C.E., Bowring, S.A.The Bell Lake group and Anton Complex: a basement cover sequence beneath the Archean Yellowknife belt..Canadian Journal of Earth Sciences, Vol. 34. No. 2, Feb. pp. 169-189Northwest TerritoriesGreenstone belt formation, Geochronology Slave Province
DS1998-0151
1998
Bowring, S.A.Bowring, S.A.Geochronology comes of age... technology, ion microprobe..Geotimes, Vol. 43, No. 11, Nov. pp. 36-40.GlobalGeochronology, General - brief history ( not specific to diamonds)
DS1998-0152
1998
Bowring, S.A.Bowring, S.A.The imperfect Archean crustal record : implications for crustal growth andrecycling.Geological Society of America (GSA) Annual Meeting, abstract. only, p.A206.GlobalTectonics, Continent formation
DS1998-0574
1998
Bowring, S.A.Hanson, R.E., Martin, M.W., Bowring, S.A., Munyanyiwauranium-lead (U-Pb) zircon age for Umkondo dolerites, eastern Zimbabwe: 1.1 Ga large igneous province ....Geology, Vol. 26, No. 12, Dec. pp. 1143-6.Zimbabwe, South Africa, AntarcticaGeochronology, Rodinia, Gondwana, Magmatism
DS1998-1143
1998
Bowring, S.A.Pedrick, J.N., Karstrom, K.E., Bowring, S.A.Reconciliation of conflicting tectonic models for Proterozoic rocks of northern New MexicoJournal of Met. Geol, Vol. 16, No. 5, Sept. pp. 687-New MexicoTectonics
DS1998-1297
1998
Bowring, S.A.Schmitz, M.D., Bowring, S.A., Robey, J.A.Constraining the thermal history of an Archean craton: uranium-lead (U-Pb)thermochronology of lower crustal xenoliths...7th. Kimberlite Conference abstract, pp. 766-8.South AfricaCraton - Kaapvaal, Geochronology, geothermometry
DS1999-0087
1999
Bowring, S.A.Bowring, S.A., Martin, M.W.high Pressure precision uranium-lead (U-Pb) geochronology, the tempo of evolution and the recordfrom Gondwana.Journal of African Earth Sciences, Vol. 28, No. 1, pp. 187-201.Geochronology
DS1999-0307
1999
Bowring, S.A.Hildebrand, R.S., Bowring, S.A.Crustal recycling by slab failureGeology, Vol. 27, No. 1, Jan. pp. 11-14.Northwest TerritoriesTectonics, Wopmay orogen, Morel Sills, Subduction, slab
DS2000-0869
2000
Bowring, S.A.Schmitz, M.D., Bowring, S.A.Constraints on the thermal evolution of the deep crust of the Kaapvaal Craton from uranium-lead (U-Pb) rutile xenoliths..Geological Society of America (GSA) Abstracts, Vol. 32, No. 7, p.A-164.South AfricaGeochronology - lower crustal, Craton - Kaapvaal
DS2000-0931
2000
Bowring, S.A.Stevens, L.M., Williams, M.L., Bowring, S.A., FarmerPetrology of lower crustal xenoliths across the Cheyenne Belt Implications for evolution and seismics..Geological Society of America (GSA) Abstracts, Vol. 32, No. 7, p.A-386.Wyoming, New MexicoXenoliths, Geophysics - seismic imaging of the lower crust
DS2001-0078
2001
Bowring, S.A.Baldwin, J.A., Williamsn, M.L., Bowring, S.A.Petrology and metamorphic evolution of high pressure granulites and eclogites from Snowbird tectonic zone.Geological Association of Canada (GAC) Annual Meeting Abstracts, Vol. 26, p.6, abstract.Saskatchewan, northernEcologites, Thermobarometry
DS2001-0171
2001
Bowring, S.A.Chamberlain, K.R., Bowring, S.A.Apatite feldspar uranium-lead (U-Pb) thermochronometer: a reliable mid-range (-450C) diffusion controlled systemChemical Geology, Vol. 172, No. 1-2, Feb. pp.173-200.GlobalGeochronology, Geothermometry
DS2001-1034
2001
Bowring, S.A.Schmitz, M.D., Bowring, S.A.The significance of uranium-lead (U-Pb) zircon dates in lower crustal xenoliths from the southwestern margin of Kaapvaal...Chemical Geology, Vol. 172, No. 1-2, Feb. pp. 59-76.South Africa, southernGeochronology, Craton - Kaapvaal
DS2002-0339
2002
Bowring, S.A.Crowley, J.L., Mazel, J.P., Bowring, S.A., Williams, M.L., Farmer, G.L.Paleoproterozoic to mesoproterozoic evolution of southwestern North America: the view from the lower crust.Geological Society of America Annual Meeting Oct. 27-30, Abstract p. 253.Wyoming, New MexicoDeformation, xenoliths
DS2002-1313
2002
Bowring, S.A.Rasskazov, S.V., Bowring, S.A., Hawsh, T., et al.The Pb Nd Sr isotope systematics in heterogeneous continental lithosphere above the convecting mantle domain.Doklady, Vol. 387A, Nov-Dec. No. 9, pp. 1056-9.MantleGeochronology, Convection
DS2002-1316
2002
Bowring, S.A.Razzkazov, S.V., Bowring, S.A., Hawsh, T., Demonterova, E.I., Logachev, N.A.The Pb Nd and Sr isotope systematics in heterogeneous continental lithosphere aboveDoklady Earth Sciences, Vol. 387A, 9. pp. 1056-9.MantleGeochronology, Convection
DS2003-0065
2003
Bowring, S.A.Baldwin, J.A., Bowring, S.A., Williams, M.L.Petrological and geochronological constraints on high pressure, high temperatureJournal of Metamorphic Geology, Vol. 21, 1, pp. 81-98.Alberta, SaskatchewanGeochronology, UHP
DS2003-0094
2003
Bowring, S.A.Bell, D.R., Gregoire, M., Grove, T.L., Chatterjee, N.D., Bowring, S.A.Silica and carbon deposition in Kimberley peridotites8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, AbstractSouth AfricaMantle petrology, Deposit - Bultfontein
DS2003-0551
2003
Bowring, S.A.Hargrove, U.S., Hanson, R.E., Martin, M.W., Blenkinsop, T.G., Bowring, S.A.Tectonic evolution of the Zambesi orogenic belt: geochronological, structural andPrecambrian Research, Vol. 123, 2-4, pp. 159-186.ZimbabweBlank
DS2003-1229
2003
Bowring, S.A.Schmidt, M.D., Bowring, S.A.Ultrahigh temperature metamorphism in the lower crust during NeoarcheanGeological Society of America Bulletin, Vol. 115, 5, pp. 533-48.South AfricaGeochronology, tectonics - not specific to diamonds
DS2003-1230
2003
Bowring, S.A.Schmitz, M.D., Bowring, S.A.Constraints on the thermal evolution of continental lithosphere from U Pb accessoryContributions to Mineralogy and Petrology, Vol. 144, pp. 592-618.South AfricaGeothermometry
DS2003-1232
2003
Bowring, S.A.Schmitz, M.D.,Bowring, S.A.Ultrahigh temperature metamorphism in the lower crust during NeoarcheanGeological Society of America Bulletin, Vol. 115, 5, May pp. 533-48.South AfricaMetamorphism, Craton
DS2003-1287
2003
Bowring, S.A.Singletary, S.J., Hanson, R.E., Martin, M.W., Crowley, J.L., Bowring, S.A., KeyGeochronology of basement rocks in the Kalahari desert, Botswana, and implicationsPrecambrian Research, Vol. 121,1-2, Feb. 28, pp. 47-71.BotswanaGeochronology, Crustal provinces, belts - not specific to diamonds
DS200412-0088
2004
Bowring, S.A.Baldwin, J.A., Bowring, S.A., Williams, M.L., Williams, I.S.Eclogites of the Snowbird tectonic zone: petrological and U Pb geochronological evidence for Paleoproterozoic high pressure metaContributions to Mineralogy and Petrology, Vol. 147, 5, pp. 528-48.Canada, Saskatchewan, Alberta, Northwest TerritoriesEclogite, shield
DS200412-0127
2003
Bowring, S.A.Bell, D.R., Gregoire, M., Grove, T.L., Chatterjee, N.D., Bowring, S.A.Silica and carbon deposition in Kimberley peridotites.8 IKC Program, Session 6, AbstractAfrica, South AfricaMantle petrology Deposit - Bultfontein
DS200412-0561
2004
Bowring, S.A.Flowers, R.M., Royden, L.H., Bowring, S.A.Isostatic constraints on the assembly, stabilizatin and preservation of cratonic lithosphere.Geology, Vol. 32, 4, April pp. 321-4.MantleCraton, geothermometry
DS200412-0787
2004
Bowring, S.A.Hanson, R.E., Crowley, J.L., Bowring, S.A., et al.Coeval large scale magmatism in the Kalahari and Laurentian cratons during Rodinia assembly.Science, Vol. 304, 5674, May 21, pp.Africa, South AfricaMagmatism
DS200412-0788
2004
Bowring, S.A.Hanson, R.E., Gose, W.A., Crowley, J.L., Ramezani, J., Bowring, S.A., Bullen, D.S., Hall, R.P., Pancake, J.A.Paleoproterozoic intraplate magmatism and basin development on the Kaapvaal Craton: age, paleomagnetism and geochemistry of 1.93South African Journal of Geology, Vol. 107, 1/2, pp. 233-254.Africa, South AfricaCraton, tectonics, magmatism
DS200412-0790
2003
Bowring, S.A.Hargrove, U.S., Hanson, R.E., Martin, M.W., Blenkinsop, T.G., Bowring, S.A., Walker, N., Munyanyiwa, H.Tectonic evolution of the Zambesi orogenic belt: geochronological, structural and petrological constraints from northern ZimbabwPrecambrian Research, Vol. 123, 2-4, pp. 159-186.Africa, ZimbabweTectonics
DS200412-1758
2003
Bowring, S.A.Schmidt, M.D., Bowring, S.A.Ultrahigh temperature metamorphism in the lower crust during Neoarchean Ventersdorp rifting and magmatism Kaapvaal Craton, southGeological Society of America Bulletin, Vol. 115, 5, pp. 533-48.Africa, South AfricaGeochronology, tectonics - not specific to diamonds
DS200412-1760
2003
Bowring, S.A.Schmitz, M.D., Bowring, S.A.Ultrahigh temperature metamorphism in the lower crust during Neoarchean Ventersdorp rifting and magmatism, Kaapvaal Craton, soutGeological Society of America Bulletin, Vol. 115, 5, May pp. 533-48.Africa, South AfricaMetamorphism Craton
DS200412-1761
2004
Bowring, S.A.Schmitz, M.D., Bowring, S.A., De Wit, M.J., Gartz, V.Subduction and terrane collision stabilize the western Kaapvaal Craton tectosphere 2.9 billion years ago.Earth and Planetary Science Letters, Vol. 222, 2, pp. 363-376.Africa, South AfricaSubduction, tectonics, continental lithosphere
DS200512-0278
2005
Bowring, S.A.Farmer, G.L., Bowring, S.A., Willams, M.L., Christensen, N.I., Matzel, J.P., Stevens, L.Contrasting lower crustal evolution across an Archean Proterozoic suture: physical, chemical and geochronologic studies of lower crustal xenoliths in southern Wyoming and northern Colorado.American Geophysical Union, Geophysical Monograph, No. 154, pp. 139-162.United States,Wyoming, Colorado PlateauGeophysics - seismics, tectonics
DS200612-0290
2006
Bowring, S.A.Crowley, J.L., Schmitz, M.D., Bowring, S.A., Williams, M.L., Karlstrom, K.E.U Pb Hf isotopic analysis of zircon in lower crustal xenoliths from the Navajo volcanic field: 1.4 Ga mafic magmatism and metamorphism beneath Colorado Plateau.Contributions to Mineralogy and Petrology, Vol. 151, 3, pp. 313-330.United States, Colorado PlateauGeochronology
DS200612-0399
2006
Bowring, S.A.Flowers, R.M., Bowring, S.A., Williams, M.L.Timescales and significance of high pressure, high temperature metamorphism and mafic dike anatexis Snowbird tectonics zone, Canada.Contributions to Mineralogy and Petrology, Vol. 151, 5, May pp. 558-581.Canada, SaskatchewanMagmatism, Chipman mafic dikes, geochronology
DS200612-0400
2006
Bowring, S.A.Flowers, R.M., Mahan, K.H., Bowring, S.A., Williams, M.L., Pringle, M.S., Hodges, K.V.Multistage exhumation and juxaposition of lower continental crust in the western Canadian Shield: linking high resolution U Pb and 40 Ar / 39 Ar thermochronometry with pressure temperature deformation paths.Tectonics, Vol. 25, 4, TC4003, 20p.Canada, Alberta, Saskatchewan, Northwest TerritoriesGeothermometry, thermocrhonmetry, deformation P T
DS200612-1243
2006
Bowring, S.A.Schoene, B., Bowring, S.A.Determining accurate temperature time paths from U Pb thermochronology: an example from the Kaapvaal craton, southern Africa.Geochimica et Cosmochimica Acta, In press available,Africa, South AfricaGeochronology, geothermometry
DS200712-0097
2007
Bowring, S.A.Bowring, S.A., Crowley, J.L., Ramezani, J., McLean, N., Condon, D., Schoene, B.High precision U Pb zircon geochronology: progress and potential.Plates, Plumes, and Paradigms, 1p. abstract p. A117.MantleGeochronology - EARTHTIME
DS200712-0304
2005
Bowring, S.A.Farmer, G.L., Bowring, S.A., Williams, M.I., Christiensen, N.I., Matzel, J., Stevens, I.Contrasting lower crustal evolution across an Archean Proterozoic suture, physical, chemical and geochronologic studies of lower crustal xenoliths....Keller & Karlstrom: The Rocky Mountain Region, American Geophysical Union, No. 154, pp. 139-162.United States, Wyoming, Colorado PlateauGeochronology
DS200812-0357
2008
Bowring, S.A.Flowers, R.M., Bowring, S.A., Mahan, K.H., Williams, M.L., Wiliams, I.S.Stabilization and reactivation of cratonic lithosphere from the lower crustal record in the western Canadian Shield.Contributions to Mineralogy and Petrology, in press available, 21p.Canada, SaskatchewanCraton
DS200812-0358
2008
Bowring, S.A.Flowers, R.M., Bowring, S.A., Mahan, K.H., Williams, M.L., Williams, I.S.Stabilization and reactivation of cratonic lithosphere from the lower crustal record in the western Canadian Shield.Contributions to Mineralogy and Petrology, Vol. 156, 4, pp. 529-549.Canada, Northwest TerritoriesCraton
DS200812-0359
2008
Bowring, S.A.Flowers, R.M., Bowring, S.A., Mahan, K.H., Williams, M.L., Williams, I.S.Stabilization and reactivation of cratonic lithosphere from the lower crustal record in the western Canadian shield.Contributions to Mineralogy and Petrology, in press available, 21p.Canada, Alberta, Saskatchewan, ManitobaGeochronology, recycling
DS200912-0020
2008
Bowring, S.A.Ault, A.K., Flowers, R.M., Bowring, S.A.Phanerozoic burial and unroofing of the western Slave Craton and Wopmay Orogen from apatite ( U Th/He thermochronometry, assessing links between surface/deepAmerican Geological Union, Fall meeting Dec. 15-19, Eos Trans. Vol. 89, no. 53, meeting supplement, 1p. abstractCanada, Northwest TerritoriesGeodynamic processes
DS201112-0091
2011
Bowring, S.A.Blackburn, T., Bowring, S.A., Schoene, B., Mahan, K., Dudas, F.U-Pb thermochronology: creating a temporal record of lithosphere thermal evolution.Contributions to Mineralogy and Petrology, in press, availableMantleGeothermometry - xenoliths
DS201112-0410
2011
Bowring, S.A.Hanson, R.E., Rioux, M., Gose, W.A., Blackburn, T.J., Bowring, S.A., Mukwakwami, J., Jones, D.L.Paleomagnetic and geochronological evidence for large scale post 1.88 Ga displacement between Zimbabwe and Kaapvaal Cratons along the Limpopo belt.Geology, Vol.39, 5, pp. 487-490.Africa, South Africa, ZimbabweGeochronology
DS201201-0837
2011
Bowring, S.A.Condon, D.J., Bowring, S.A.A user's guide to Neoproterozoic geochronology.The Geological Record of Neoproterozoic glaciations, Memoirs 2011; Vol. 36, pp. 135-149GlobalTerminology
DS201312-0041
2013
Bowring, S.A.Ault, A.K., Flowers, R.M., Bowring, S.A.Phanerozoic surface history of the Slave Craton.Tectonics, Vol. 32, 5, pp. 1066-1083.Canada, Northwest TerritoriesCraton
DS201412-0908
2014
Bowring, S.A.Swanson-Hysell, N.L., Burgess, S.D., Maloof, A.C., Bowring, S.A.Magmatic activity and plate motion during the latent stage of Midcontinent Rift development.Geology, Vol. 42, pp. 475-478.United StatesStructure - rifting
DS1993-0149
1993
Bowyer, G.J.Bowyer, G.J.Valuing Mines with limited demonstrated reservesMining Industry International, No. 1010, January pp. 7-11GlobalEconomics, Ore Reserves, geostatistics, taxation
DS1986-0096
1986
Box, S.E.Box, S.E.Early Cretaceous shoshonites in western Alaska: changing mantle sources during arc continent collisionEos, Vol. 67, No. 44, p. 1278. (abstract.)AlaskaTectonics, Shoshonite
DS1986-0399
1986
Boxer, G.Jaques, A.L., Boxer, G., Lucas, H., Haggerty, S.E.Mineralogy and petrology of the Argyle lamproite pipe, WesternProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 48-50AustraliaPetrology, Lamproite
DS2003-0144
2003
Boxer, G.Boxer, G.Alluvial diamonds - the start of an industryRough Diamond Review, September 2003, pp. 23-27Africa, South America, Australia, Asiaalluvial diamonds, history, industry overview
DS2003-0145
2003
Boxer, G.Boxer, G.Alluvial diamonds - the start of an industry. History of alluvials... India, Borneo, BrazilRough Diamond Review, No. 2, September, pp. 23-27.India, South Africa, Borneo, BrazilPlacer, alluvials - overview history
DS200412-0191
2003
Boxer, G.Boxer, G.Alluvial diamonds - the start of an industry. History of alluvials... India, Borneo, Brazil.Rough Diamond Review, No. 2, September, pp. 23-27.India, Africa, South Africa, Indonesia, Borneo, South America, BrazilPlacer, alluvials - overview history
DS200412-0192
2004
Boxer, G.Boxer, G.Spotlight on China. Expecting to discover additional economic deposits using modern exploration techniques.Rough Diamond Review, No. 5, June, pp.ChinaBrief overview exploration
DS200512-0106
2004
Boxer, G.Boxer, G.The distribution of diamond sizes in a deposit conform to mathematical distributions, enabling interpretations and predictions to be applied to diamonds recovered from core and bulk samples.Rough Diamond Review, No.7, December pp.Diamond valuation, from core and bulk samples
DS201809-1999
2018
Boxer, G.Boxer, G., Rockett, G.Geology, resources and exploration potential of the Ellendale diamond project, west Kimberley, Western Australia.Government of Western Australia, Record 2018/8. 49p.Australia, Western Australiadeposit - Ellendale
DS202006-0913
2020
Boxer, G.Boxer, G.Grant is teaching workshops for geologists on how to use QGIS - free GIS program - great for students to learn GIS."https://qgisforgeos .thinkific.com/"., GIS programGlobalGIS on line
DS1984-0123
1984
Boxer, G.L.Atkinson, W.J., Smith, C.B., Boxer, G.L.The Discovery and Evaluation of the Ellendale and Argyle Lamproite Diamond Deposits, Kimberley, Western Australia.Society for Mining, Metallurgy and Exploration (SME)-American Institute of Mining, Metallurgical, and Petroleum Engineers (AIME)., SYMPOSIUM OUTLINE FALL MEETING DENVER OCTOBER 26TH. No. 84-3Australia, Western AustraliaSampling, History
DS1986-0097
1986
Boxer, G.L.Boxer, G.L., Lorenz, V., Smith, C.B.Geology and volcanology of the Argyle (AK1) lamproite diatremeProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 21-23AustraliaLamproite
DS1986-0173
1986
Boxer, G.L.Deakin, A.S., Boxer, G.L.The Argyle AKl diamond size distribution: the use of fine diamonds to predict the occurrence of commercial size diamondsProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 448-450AustraliaDiamond exploration
DS1986-0174
1986
Boxer, G.L.Deakin, A.S., Boxer, G.L., Meakins, A.E., Haebig, E., Lew, J.H.Geology of the Argyle alluvial diamond deposits #1Proceedings of the Fourth International Kimberlite Conference, Held, No. 16, pp. 451-453AustraliaDiamond exploration
DS1986-0503
1986
Boxer, G.L.Lorenz, V., Boxer, G.L., Smith, C.B.Volcanology of the diamond bearing lamproite tuff vents in the KimberleyRegion, western Australia. (in German)Fortschritte der Mineralogie, (in German), Vol. 64, No. 1, p. 100. Abstract onlyAustraliaLamproite
DS1989-0159
1989
Boxer, G.L.Boxer, G.L., Lorenz, V., Smith, C.B.The geology and volcanology of the Argyle (AK 1)lamproitic diatreme, Western AustraliaGeological Society of Australia Inc. Blackwell Scientific Publishing, Special, No. 14, Vol. 1, pp. 140-152AustraliaDeposit -Argyle, Lamproite
DS1989-0344
1989
Boxer, G.L.Deakin, A.S., Boxer, G.L.Argyle AK1 diamond size distribution: the use of fine diamonds to predict the occurrence of commercial sizediamondsGeological Society of Australia Inc. Blackwell Scientific Publishing, Special, No. 14, Vol. 2, pp. 1117-1122AustraliaDiamond distribution, Deposit -Argyle
DS1989-0345
1989
Boxer, G.L.Deakin, A.S., Boxer, G.L., Meakins, A.E., Haebig, A.E., Lew, J.H.Geology of the Argyle alluvial diamond deposits #2Geological Society of Australia Inc. Blackwell Scientific Publishing, No. 14, Vol. 2, pp. 1108-1116AustraliaAlluvial-placers, Deposit -Argyle
DS1989-0704
1989
Boxer, G.L.Jaques, A.L., Haggerty, S.E., Lucas, H., Boxer, G.L.Mineralogy and petrology of the Argyle (AK1) lamproite pipe, westernAustraliaGeological Society of Australia Inc. Blackwell Scientific Publishing, Special, No. 14, Vol. 1, pp. 153-169AustraliaDeposit -Argyle, Lamproite
DS1990-0231
1990
Boxer, G.L.Boxer, G.L., Deakin, A.S.Argyle alluvial depositsIn: Geology of the Mineral Deposits of Australia and Papua New Guinea ed., Vol. 2, pp. 1655-1658AustraliaAlluvials, Deposit -Argyle
DS1990-0602
1990
Boxer, G.L.Grice, J.D., Boxer, G.L.Diamonds from Kimberley, Western AustraliaThe Mineralogical Record, Vol. 21, No. 6, November-December pp. 559-564AustraliaHistory, Diamonds morphology
DS2003-0242
2003
Boxer, G.L.Chapman, J.G., Boxer, G.L.Size distribution analyses for estimating diamond grade and value8ikc, Www.venuewest.com/8ikc/program.htm, Session 1 POSTER abstractGlobalKimberlite geology and economics
DS201511-1828
2004
Boxer, G.L.Chapman, J.G., Boxer, G.L.Size distribution analyses for estimating grade and value.Lithos, Vol. 76, pp. 369-375. Available pdfTechnologyMicrodiamonds - responses

Abstract: Analysing the size frequency distributions (SFDs) of both micro diamonds and macro diamonds from primary deposits shows that the distributions are continuous across all sizes and that there are two regions of different character with a transition about 1-2 mm. Using log axes, the frequency curve is linear for the smaller sizes allowing slope and intercept parameters to be determined which are less ambiguous than stone counts and ratios of macro to micro populations that are generally reported. Modelling a diamond population that has undergone removal of a uniform thickness of the outer layer transforms a linear frequency curve into a quadratic form, which is also the form of the frequency curve for macro diamonds. Diamonds grown synthetically also display a linear distribution across a smaller fraction of their size distribution curve.
DS201804-0674
2017
Boxer, G.L.Boxer, G.L., Jaques, A.L., Rayner, M.J.Argyle ( AK1) diamond deposit.Australian Ore Deposits, AusIMM Monograph 32, ed. Phillips, N., pp. 527-532.Australiadeposit - Argyle
DS201809-2078
2018
Boxer, G.L.Rayner, M.J., Moss, S.W., Lorenz, V., Jaques, L., Boxer, G.L., Smith, C.B., Webb, K.New insights into volcanic processes from deep mining of the southern diatreme within the Argyle lamproite pipe, Western Australia.Mineralogy and Petrology, doi.org/10.1007/ s00710-018-0625-4 13p.Australia, Western Australiadeposit - Argyle

Abstract: Underground mining and deep drilling of the richly diamondiferous ~1.2 Ga Argyle lamproite in Western Australia has prompted a re-evaluation of the geology of the pipe. Argyle is considered to be a composite pipe that formed by the coalescence of several diatremes and has been offset and elongated by post-emplacement faulting. Recent geological studies have recognised at least five distinct volcaniclastic lamproite lithofacies with differing diamond grades. The new data suggest that the centre of the southern (main) diatreme is occupied by well-bedded, olivine lamproite lapilli tuff with very high diamond grades (>10 ct/t). Characteristic features include a clast-supported fabric and high modal abundance of densely packed lamproite lapilli and coarse-grained, likely mantle-derived olivine now replaced by serpentine and/or talc. The persistence of small-scale graded and cross-bedding in this lithofacies to depths of ~1.5 km below the original surface prior to erosion suggests phreatomagmatic volcanism forming the diatreme was syn-eruptively accompanied by subsidence of the tephra, maintaining a steep-walled diatreme in the water-saturated country rock sediments.
DS201812-2869
2018
Boxer, G.L.Rayner, M.J., Jaques, A.L., Boxer, G.L., Smith, C.B., Lorenz, V., Moss, S.W., Webb, K., Ford, D.Argyle deposit: The geology of the Argyle ( AK1) diamond deposit, western Australia.Society of Economic Geology Geoscience and Exploration of the Argyle, Bunder, Diavik, and Murowa Diamond Deposits, Special Publication no. 20, pp. 89-118.Australia, western Australiadeposit - Argyle
DS200612-0159
2005
Boy, J.P.Boy, J.P., Chao, B.F.Precise evaluation of atmospheric loading effects on Earth's time variable gravity field.Journal of Geophysical Research, Vol. 110, B8, BO8412MantleGeophysics - gravity
DS1987-0536
1987
Boyarskaya, R.V.Novgorodova, M.I., Galushkin, E.V., Boyarskaya, R.V., Mokhov, A.V.Accessory minerals of lamproite like rocks of central Asia.(Russian)Izv. Akad. Nauk SSSR, Ser. Geol, No. 4, pp. 15-27RussiaBlank
DS201609-1706
2016
Boyce, A.Boyce, A., Bastow, I.D., Darbyshire, F.A., Ellwood, A.G., Gilligan, A., Levin, V., Menke, W.Subduction beneath Laurentia modifies the eastern North American cratonic edge: evidence from P wave and S wave tomography.Journal of Geophysical Research,, Vol. 121, 7, pp. 5013-5030.CanadaSubduction

Abstract: The cratonic cores of the continents are remarkably stable and long-lived features. Their ability to resist destructive tectonic processes is associated with their thick (?250 km), cold, chemically depleted, buoyant lithospheric keels that isolate the cratons from the convecting mantle. The formation mechanism and tectonic stability of cratonic keels remains under debate. To address this issue, we use P wave and S wave relative arrival-time tomography to constrain upper mantle structure beneath southeast Canada and the northeast USA, a region spanning three quarters of Earth's geological history. Our models show three distinct, broad zones: Seismic wave speeds increase systematically from the Phanerozoic coastal domains, through the Proterozoic Grenville Province, and to the Archean Superior craton in central Québec. We also recover the NW-SE trending track of the Great Meteor hot spot that crosscuts the major tectonic domains. The decrease in seismic wave speed from Archean to Proterozoic domains across the Grenville Front is consistent with predictions from models of two-stage keel formation, supporting the idea that keel growth may not have been restricted to Archean times. However, while crustal structure studies suggest that Archean Superior material underlies Grenvillian age rocks up to ?300 km SE of the Grenville Front, our tomographic models show a near-vertical boundary in mantle wave speed directly beneath the Grenville Front. We interpret this as evidence for subduction-driven metasomatic enrichment of the Laurentian cratonic margin, prior to keel stabilization. Variable chemical depletion levels across Archean-Proterozoic boundaries worldwide may thus be better explained by metasomatic enrichment than inherently less depleted Proterozoic composition at formation.
DS201909-2050
2019
Boyce, A.Hutchison, W., Baiel, R., Finch, A., Marks, M., Markl, G., Boyce, A., Stueken, E., Friis, H., Borst, A., Horsburgh, N.Sulphur isotopes of alkaline igneous suites: new insights into magmatic fluid evolution and crustal recycling.Goldschmidt2019, 1p. AbstractGlobalalkaline rocks
DS200612-0355
2006
Boyce, A.J.Druppel, K., Wagner, T., Boyce, A.J.Evolution of sulfide mineralization in ferrocarbonatite, Swartbooisdiff, northwestern Namibia: constraints from mineral composition and sulfur isotopeCanadian Mineralogist, Vol. 44, 4, August pp. 877-894.Africa, NamibiaCarbonatite
DS202102-0175
2020
Boyce, A.J.Blanks, D.E., Holwell, D.A., Fiorentini, M.L., Moroni, M., Giuliani, A., Tassara, S., Gonzales-Jiminez, J.M., Boyce, A.J., Ferrari, E.Fluxing of mantle carbon as a physical agent for metallogenic fertilization of the crust.Nature Communications, doi.org/10.1038/ s41467-020-18157-6 11p. Pdf Mantlecarbon

Abstract: Magmatic systems play a crucial role in enriching the crust with volatiles and elements that reside primarily within the Earth’s mantle, including economically important metals like nickel, copper and platinum-group elements. However, transport of these metals within silicate magmas primarily occurs within dense sulfide liquids, which tend to coalesce, settle and not be efficiently transported in ascending magmas. Here we show textural observations, backed up with carbon and oxygen isotope data, which indicate an intimate association between mantle-derived carbonates and sulfides in some mafic-ultramafic magmatic systems emplaced at the base of the continental crust. We propose that carbon, as a buoyant supercritical CO2 fluid, might be a covert agent aiding and promoting the physical transport of sulfides across the mantle-crust transition. This may be a common but cryptic mechanism that facilitates cycling of volatiles and metals from the mantle to the lower-to-mid continental crust, which leaves little footprint behind by the time magmas reach the Earth’s surface.
DS202108-1303
2021
Boyce, J.Parnell, J., Brolly, C., Boyce, J.Graphite from paleoproterozoic enhanced carbon burial, and its metallogenic legacy. ** not specific to diamondsGeological Magazine, doi.10.1017/S0016756821000583 8p. Mantlecarbon

Abstract: The episode of widespread organic carbon deposition marked by peak black shale sedimentation during the Palaeoproterozoic is also reflected in exceptionally abundant graphite deposits of this age. Worldwide anoxic/euxinic sediments were preserved as a deep crustal reservoir of both organic carbon, and sulphur in accompanying pyrite, both commonly >1 wt %. The carbon- and sulphur-rich Palaeoproterozoic crust interacted with mafic magma to cause Ni-Co-Cu-PGE mineralization over the next billion years, and much uranium currently produced is from Mesoproterozoic deposits nucleated upon older Palaeoproterozoic graphite. Palaeoproterozoic carbon deposition has thus left a unique legacy of both graphite deposits and long-term ore deposition.
DS1991-0161
1991
Boyce, J.I.Boyce, J.I., Eyles, N.Drumlins carved by deforming till streams below the Laurentide ice sheetGeology, Vol. 19, No. 8, August, pp. 787-790OntarioGeomorphology, Drumlins
DS1999-0201
1999
Boyce, J.I.Eyles, N., Boyce, J.I., Barendregt, R.W.Hummocky moraine; sedimentary record of stagnant Laurentide ice sheet lobes resting on soft beds.Sed. Geol., Vol. 123, No. 3-4, pp. 163-74.AlbertaGeomorphology - Laurentide
DS1860-1022
1898
Boyce, N.Boyce, N.Historic Diamonds #1Lippincott's Magazine., Vol. 61, P. 389.Africa, South AfricaDiamonds Notable
DS1993-0759
1993
Boyce, T.Jones, A.G., Craven, J.A., McNeice, G.W., Ferguson, I.J., Boyce, T.North American Central Plains conductivity anomaly within the Trans-Hudson Orogen in northern Saskatchewan, Canada.Geology, Vol. 21, No. 11, November pp. 1027-1030.SaskatchewanGeophysics -magnetics, Tectonics
DS1960-1111
1969
Boychuk, M.D.Gonshakova, V.I., Ruzhitskiy, V.O., Boychuk, M.D., et al.Volcanic Pipes and Dikes of Kimberlite Rocks on the RussianplatformInternational Geology Review, Vol. LL, No. 1, PP. 60-73.RussiaBlank
DS2000-0139
2000
BoydCarlson, R.W., Janney, Shirey, Boyd, Pearson, IrvineChemical and age structure of the southern African lithospheric mantle: implications continent formationGeological Society of America (GSA) Abstracts, Vol. 32, No. 7, p.A-163.South AfricaMantle xenoliths - Kaapvaal Craton, Geophysics - seismics
DS2001-0526
2001
BoydJames, D., Boyd, Bell, Schutt, CarlsonXenolith constraints on seismic velocities in the upper mantle beneath southern Africa.Slave-Kaapvaal Workshop, Sept. Ottawa, 2p. abstractSouth Africa, BotswanaGeophysics - seismics, Tomography - Kaapvaal Craton
DS201012-0322
2010
BoydJanney, P.E., Shirey, S.B., Carlson, R.W., Pearson, D.G., Bell, D.R., Le Roex, A., Ishikawa, Nixon, BoydAge, composition and thermal characteristics of South African off craton mantle lithosphere: evidence for a multi stage history.Journal of Petrology, Vol. 51, 9, pp. 1849-1890,Africa, South AfricaGeochronology, geothermometry
DS1998-0144
1998
Boyd, B.Boucher, M.A., Boyd, B.Diamonds; Canadian Minerals Yearbook, 1998Canadian Minerals Yearbook, Section 22, 16p.Canada, Northwest Territories, Alberta, SaskatchewanDiamond - exploration overview
DS2002-0197
2002
Boyd, B.Boyd, B., Irving, M.The development of government policies on diamondsCanadian Institute of Mining and Metallurgy, Vol. 53, Industrial Minerals of Canada, pp. 363-5.CanadaLegal
DS200712-0098
2007
Boyd, D.M.Boyd, D.M., Isles, D.J.Geological interpretation of airborne magnetic surveys - 40 years on.Proceedings of Exploration 07 edited by B. Milkereit, pp. 491-505.TechnologyGeophysics - magnetics - review
DS1987-0073
1987
Boyd, F.J.Boyd, F.J., Mertzman, S.A.Composition and structure of the Kaapvaal lithosphere, Southern AfricaGeochemical Society, Spec. Publishing No. 1, pp.13-24South AfricaTectonics, Structure
DS1960-0639
1966
Boyd, F.R.Boyd, F.R.Electron Probe Study of Diospidic Pyroxenes from KimberlitesCarnegie Institute Yearbook, FOR 1965, PP. 252-260.South Africa, Southwest Africa, Namibia, Tanzania, East AfricaKimberley, Louwrencia, Shinyanga, De Beers, Wesselton, Bultfontein
DS1960-0650
1966
Boyd, F.R.Davis, B.T.C., Boyd, F.R.The Join Mg2si206 - Camgsi206 at 30 Kl Pressure and its Application to Pyroxenes from Kimberlite.Journal of Geophysical Research, Vol. 71, PP. 3567-3576.South AfricaMineralogy, Genesis
DS1960-0795
1967
Boyd, F.R.Boyd, F.R.Electron Probe Study of Diopsidic Pyroxenes from KimberlitesCarnegie Institute Yearbook, FOR 1965, PP. 252-260.South Africa, Tanzania, Southwest Africa, Namibia, East AfricaMineral Chemistry
DS1960-0926
1968
Boyd, F.R.Boyd, F.R.Pyroxene Quantitative Electron Probe Analysis of PryoxenesCarnegie Institute Yearbook, FOR 1966, PP. 327-334.GlobalMineral Chemistry
DS1960-0994
1968
Boyd, F.R.Meyer, H.O.A., Boyd, F.R.Mineral Inclusions in Diamonds 1969Carnegie Institute Yearbook, FOR 1967, PP. 130-135.GlobalAnalyses, Diamond Morphology
DS1960-1074
1969
Boyd, F.R.Boyd, F.R.The System Casio2 Magnesium Sio3 Al2o3Carnegie Institute Yearbook, FOR 1968, PP. 214-221.GlobalGarnet, Analyses, Research
DS1960-1075
1969
Boyd, F.R.Boyd, F.R.Electron Probe Study of Diopside Inclusions from KimberlitesAmerican Journal of Science, Vol. 267A, PP. 50-69.South AfricaXenoliths
DS1960-1171
1969
Boyd, F.R.Meyer, H.O.A., Boyd, F.R.Inclusions in Diamonds #1Carnegie Institute Yearbook, FOR 1968, PP. 315-320.South Africa, Sierra Leone, West Africa, Venezuela, GhanaReview Paper, Research, Diamond Morphology
DS1970-0031
1970
Boyd, F.R.Boyd, F.R.Garnet Peridotites and the System Casi02 Mgsi03 Al203Mineralogical Soc. American, SPECIAL PAPER No. 3, PP. 63-75.South Africa, United States, RussiaMicroprobe, Analyses
DS1970-0032
1970
Boyd, F.R.Boyd, F.R., Nixon, P.H.Kimberlite DiopsidesCarnegie Institute Yearbook, FOR 1968, PP. 324-329.LesothoMineralogy, Petrography
DS1970-0249
1971
Boyd, F.R.Boyd, F.R.Enstatite-ilmenite and Diopside Ilmenite Intergrowths from The Monastery Mine.Carnegie Institute Yearbook, FOR 1970, PP. 134-138.South AfricaMineral Chemistry
DS1970-0250
1971
Boyd, F.R.Boyd, F.R.Enstatite-ilmenite and Diopside Ilmenite Intergrowth from The Monastery Mine.Carnegie Institute Yearbook, FOR 1970, PP. 134-138.South AfricaMineralogy
DS1970-0251
1971
Boyd, F.R.Boyd, F.R.Pargasite Spinel Peridotite Xenolith from the Wesselton MineCarnegie Institute Yearbook, FOR 1970, PP. 138-142.South AfricaMineralogy
DS1970-0459
1972
Boyd, F.R.Akella, J., Boyd, F.R.Partioning of Titanium and Aluminum Between Pyroxenes, Garnets and OxideCarnegie Institute Yearbook, 1971, PP. 378-384.IndiaMineral Chemistry, Experimental Petrology
DS1970-0460
1972
Boyd, F.R.Akella, J., Boyd, F.R.Partitioning of Titanium and Aluminum between Pyroxenes, Garnets and oxides.Carnegie Institute Yearbook, FOR 1971, PP. 378-384.Lesotho, South AfricaMatsoku, Skaergaard, Research
DS1970-0481
1972
Boyd, F.R.Boyd, F.R., Dawson, J.B.Kimberlite Garnets and Pyroxene Ilmenite IntergrowthsCarnegie Institute Yearbook, FOR 1971, PP. 373-378.South Africa, Scotland, New Zealand, OceaniaMineralogy, Monastery, Frank Smith, Excelsior, Elie Ness, Kakanui
DS1970-0482
1972
Boyd, F.R.Boyd, F.R., Nixon, P.H.Structure of the Upper Mantle Beneath LesothoCarnegie Institute Yearbook, FOR 1972, PP. 431-445.LesothoTectonics
DS1970-0483
1972
Boyd, F.R.Boyd, F.R., Nixon, P.H.Ultramafic Nodules from the Thaba Putsoa Kimberlite PipeCarnegie Institute Yearbook, FOR 1971, PP. 362-373.LesothoXenoliths
DS1970-0561
1972
Boyd, F.R.Meyer, H.O.A., Boyd, F.R.Composition and Origin of Crystalline Inclusions in Naturaldiamond.Geochimica Et Cosmochimica Acta., Vol. 36, PP. 1255-1273.South Africa, Venezuela, ThailandDiamond Morphology
DS1970-0636
1973
Boyd, F.R.Boyd, F.R.A Pyroxene GeothermGeochimica Et Cosmochimica Acta, Vol. 37, No. 12, PP. 2533-2546.South AfricaMineralogy
DS1970-0637
1973
Boyd, F.R.Boyd, F.R., Nixon, P.H.Origin of the Lherzolite Nodules in the Kimberlites of Northern Lesotho.1st International Kimberlite Conference, EXTENDED ABSTRACT VOLUME, PP. 47-50.LesothoGenesis, Xenoliths, Mineral Chemistry
DS1970-0638
1973
Boyd, F.R.Boyd, F.R., Nixon, P.H.Origin of the Ilmenite Silicate Nodules in Kimberlites From lesotho and South Africa.In: Lesotho Kimberlites, P.h. Nixon, Ed., PP. 254-268.Lesotho, South AfricaPetrography, Petrology, Xenoliths
DS1970-0712
1973
Boyd, F.R.Hearn, B.C.JR., Boyd, F.R.Garnet Peridotite Xenoliths in a Montana Kimberlite. #1International Kimberlite Conference FIRST, EXTENDED ABSTRACT VOLUME., PP. 167-169.United States, Montana, Rocky MountainsKimberlite, Rocky Mountains
DS1970-0785
1973
Boyd, F.R.Nixon, P.H., Boyd, F.R.The Liqhobong Intrusions and Kimberlitic Olivine CompositionMaseru: Lesotho Nat. Dev. Corp. Lesotho Kimberlites Editor N, PP. 141-148.LesothoGeology, Nodules, Mineral Chemistry
DS1970-0786
1973
Boyd, F.R.Nixon, P.H., Boyd, F.R.Deep Seated NodulesMaseru: Lesotho Nat. Dev. Corp. Lesotho Kimberlites Editor N, PP. 106-109.LesothoMineral Chemistry
DS1970-0787
1973
Boyd, F.R.Nixon, P.H., Boyd, F.R.Petrogenesis of the Granular and Sheared Ultrabasic Nodule Suite in Kimberlite.Maseru: Lesotho Nat. Dev. Corp. Lesotho Kimberlites Editor N, PP. 48-56.LesothoMineral Chemistry, Thaba Putsoa, Mothae
DS1970-0788
1973
Boyd, F.R.Nixon, P.H., Boyd, F.R.The Petrogenesis of the Granular and Sheared Ultrabasic Nodule Suite in Kimberlites.In: Lesotho Kimberlites, P.h. Nixon Ed., PP. 48-56.LesothoPetrography
DS1970-0789
1973
Boyd, F.R.Nixon, P.H., Boyd, F.R.Carbonated Ultrabasic Nodules from SekamengMaseru: Lesotho Nat. Dev. Corp. Lesotho Kimberlites Editor N, PP. 190-196.LesothoXenoliths, Mineral Chemistry
DS1970-0790
1973
Boyd, F.R.Nixon, P.H., Boyd, F.R.The Discrete Nodule Association in Kimberlites from Northern Lesotho.Maseru: Lesotho Nat. Dev. Corp. Lesotho Kimberlites Editor N, PP. 67-75.Lesotho, South AfricaThaba Putsoa, Solane, Letseng la Terae, Lemphane, Sekameng, Pipe
DS1970-0791
1973
Boyd, F.R.Nixon, P.H., Boyd, F.R.Discrete Nodules (megacrysts) and Lamellar Intergrowths in The Frank Smith Kimberlite Pipe.1st International Kimberlite Conference, EXTENDED ABSTRACT VOLUME, PP. 243-246.South AfricaMineral Chemistry
DS1970-0792
1973
Boyd, F.R.Nixon, P.H., Boyd, F.R.Notes on the Heavy Mineral ConcentratesMaseru: Lesotho Nat. Dev. Corp. Lesotho Kimberlites Editor N, PP. 218-220.South AfricaMonastery Mine
DS1970-0793
1973
Boyd, F.R.Nixon, P.H., Boyd, F.R., Boullier, A.The Evidence of Kimberlite and its Inclusions on the Constitution of the Outer Part of the Earth.Maseru: Lesotho Nat. Dev. Corp. Lesotho Kimberlites Editor N, PP. 312-318.Lesotho, South AfricaGenesis
DS1970-0826
1973
Boyd, F.R.Shimizu, N., Boyd, F.R.Trace Element Contents of Clinopyroxenes from Garnet Lherzolites in Kimberlites.Carnegie Institute Yearbook, FOR 1972, PP. 272-276.United States, HawaiiBlank
DS1970-0861
1974
Boyd, F.R.Akella, J., Boyd, F.R.Petrogenetic Grid for Garnet LherzolitesCargegie Institute Yearbook For 1973, PP. 269-273.South AfricaMineral Chemistry, Petrography
DS1970-0882
1974
Boyd, F.R.Boyd, F.R.The Mantle Sample from Kimberlites and an Estimated GeothermEos, Vol. 55, No. 7, P. 673. (abstract.).South AfricaGeothermometry
DS1970-0883
1974
Boyd, F.R.Boyd, F.R.Olivine Megacrysts from the Kimberlites of the Monastery And Frank Smith Mines, South Africa.Carnegie Institute Yearbook, FOR 1973, PP. 282-285.South AfricaPetrography
DS1970-0884
1974
Boyd, F.R.Boyd, F.R.Ultramafic Nodules from the Frank Smith Kimberlite Pipe, South Africa.Carnegie Institute Yearbook, FOR 1973, PP. 285-294.South AfricaPetrography
DS1970-0885
1974
Boyd, F.R.Boyd, F.R., Danchin, R.V.Discrete Nodules from the Artur de Paiva Kimberlite, AngolaCarnegie Institute Yearbook, FOR 1973, PP. 278-282.AngolaPetrography
DS1975-0038
1975
Boyd, F.R.Boyd, F.R.Chemical In homogeneities in Minerals in Kimberlite Nodules from Lesotho and the Kimberley Pipes.International Conference ON GEOTHERMOMETRY AND GEOBAROMETRY, HELD PENN., EXTENDED ABSTRACT VOLUME, 4P.Lesotho, South AfricaMineral Chemistry
DS1975-0039
1975
Boyd, F.R.Boyd, F.R., Finger, L.W.Homogeneity of Minerals in Mantle Rocks from LesothoCarnegie Institute Yearbook, FOR 1974, PP. 519-528.LesothoPetrography
DS1975-0040
1975
Boyd, F.R.Boyd, F.R., Nixon, P.H.Origins of Ultramafic Nodules from Some Kimberlites in Northern Lesotho and the Monastery Mine, South Africa.Physics and Chemistry of the Earth., Vol. 9, PP. 431-454.South Africa, LesothoPetrography, Genesis
DS1975-0102
1975
Boyd, F.R.Hearn, B.C.JR., Boyd, F.R.Garnet Peridotite Xenoliths in a Montana Kimberlite. #2Physics Chem. Earth., Vol. 9, PP. 247-256.United States, Montana, Rocky MountainsBlank
DS1975-0150
1975
Boyd, F.R.Nixon, P.H., Boyd, F.R.Mantle Evolution Based on Studies of Kimberlitic Nodules From Southern Africa.Leeds University Research Institute of African Geology Annual Report 19th., Vol. 19, P. 26.South AfricaXenoliths, Petrography
DS1975-0151
1975
Boyd, F.R.Nixon, P.H., Boyd, F.R.Studies on the Upper Mantle Lower Crust: IntroductionLeeds University Research Institute of African Geology Annual Report 19th., PP. 25-31.South Africa, LesothoKimberlite Genesis
DS1975-0214
1975
Boyd, F.R.Wyatt, B., Mccallister, R.H., Boyd, F.R., Ohashi, Y.An Experimentally Produced Clinopyroxene Ilmenite IntergrowtCarnegie Institute Yearbook, FOR 1974, PP. 536-542.South AfricaNodules, Petrography
DS1975-0249
1976
Boyd, F.R.Boyd, F.R.Inflected and Noninflected GeothermsCarnegie Institute Yearbook, FOR 1975, PP. 521-531.RussiaGeothermometry
DS1975-0250
1976
Boyd, F.R.Boyd, F.R., Nixon, P.H.Ultramafic Nodules from the Kimberley PipesCarnegie Institute Yearbook, FOR 1975, PP. 544-546.South AfricaPetrography
DS1975-0265
1976
Boyd, F.R.Danchin, R.V., Boyd, F.R.Ultramafic Nodules from the Premier Kimberlite Pipe, South Africa.Carnegie Institute Yearbook, FOR 1975, PP. 531-538.South AfricaPetrography
DS1975-0343
1976
Boyd, F.R.Merkel, G.A. , Haggerty, S.E., Boyd, F.R.A Unique Olivine Megacryst from the Monastery MineEos, Vol. 57, No. 4, P. 355. (abstract.).South AfricaPetrography
DS1975-0469
1977
Boyd, F.R.Boyd, F.R., Clement, C.R.Compositional Zoning of Olivines in Kimberlite from the de Beers Mine.Carnegie Institute Yearbook, FOR 1976, PP. 485-493.South AfricaPetrography
DS1975-0695
1978
Boyd, F.R.Boctor, N.Z., Boyd, F.R.Oxide Minerals in Liqhobong KimberliteCarnegie Institute Yearbook, FOR 1977, PP. 870-876.LesothoMineral Chemistry
DS1975-0701
1978
Boyd, F.R.Boyd, F.R., Klement, K.N.Zoning in Olivine in the Kimberlite Pipes from de Beers Kimberley, South Africa.Akad. Nauk. Sssr Sib. Otd. Geofiz., No. 403, PP. 364-375.South AfricaPetrography
DS1975-0702
1978
Boyd, F.R.Boyd, F.R., Nixon, P.H.Ultramafic Nodules from the Kimberley Pipes, South AfricaGeochimica Et Cosmochimica Acta, Vol. 42, PP. 1367-1382.South AfricaPetrography, Mineral Chemistry
DS1975-0703
1978
Boyd, F.R.Boyd, F.R., Pasteris, J.D.Ilmenite Associations at the Frank Smith Kimberlite PipeCarnegie Institute Yearbook, FOR 1977, PP. 866-870.South AfricaPetrography
DS1975-0906
1979
Boyd, F.R.Akella, J., Rao, P.S., Mcallister, R.H., Boyd, F.R., Meyer, H.O.Mineralogical Studies on the Diamondiferous Kimberlite of The Wajrakarur Area, Southern India #2Proceedings of Second International Kimberlite Conference, Vol. 1, PP. 172-177.India, Andhra PradeshMineralogy
DS1975-0949
1979
Boyd, F.R.Boctor, N.Z., Boyd, F.R.Oxide Minerals in Layered Kimberlite Carbonate Sills from Benfontein.Carnegie Institute Yearbook, FOR 1978, PP. 493-496.South AfricaMineral Chemistry
DS1975-0950
1979
Boyd, F.R.Boctor, N.Z., Boyd, F.R.Petrology of Kimberlite from the de Bruyn and Martin Mine Bellsbank #2Carnegie Institute Yearbook, FOR 1978, PP. 496-498.South AfricaPetrology
DS1975-0951
1979
Boyd, F.R.Boctor, N.Z., Boyd, F.R.Petrology of Kimberlite from the de Bruyn and Martin Mine Bellsbank #1Eos, Vol. 60, No. 18, P. 418. (abstract.).South AfricaPetrology
DS1975-0952
1979
Boyd, F.R.Boctor, N.Z., Boyd, F.R.Distribution of Rare Earth Elements in Perovskite from Kimberlites.Carnegie Institute Yearbook, FOR 1978, PP. 572-574.South AfricaRare Earth Elements (ree), Isotope
DS1975-0957
1979
Boyd, F.R.Boyd, F.R., Meyer, H.O.A.Kimberlite, Diatremes and Diamonds: Their Geology, Petrology and Geochemistry.Proceedings SECOND International Kimberlite Conference, Vol. 1, 399P.GlobalKimberlite, Kimberley, Janlib
DS1975-0958
1979
Boyd, F.R.Boyd, F.R., Meyer, H.O.A.The Mantle Sample: Inclusions in Kimberlites and Other Volcanics.Proceedings SECOND International Kimberlite Conference, Vol. 2, 423P.GlobalKimberlite, Kimberley, Janlib
DS1975-0959
1979
Boyd, F.R.Boyd, F.R., Nixon, P.H.Garnet Lherzolite Xenoliths from the Kimberlites of East Griqualand. #1Carnegie Institute Yearbook, FOR 1978, PP. 488-492.South AfricaPetrography
DS1975-0960
1979
Boyd, F.R.Boyd, F.R., Nixon, P.H.Garnet Lherzolite Xenoliths from the Kimberlites of East Griqualand. #2Geological Society of America (GSA), Vol. 11, No. 7, P. 392, (abstract.).South AfricaPetrography
DS1975-1175
1979
Boyd, F.R.Pasteris, J.D., Boyd, F.R., Nixon, P.H.The Ilmenite Association at the Frank Smith Mine, South Africa.Proceedings of Second International Kimberlite Conference, Proceedings Vol. 2, PP. 265-278.South AfricaMineralogy
DS1980-0066
1980
Boyd, F.R.Boctor, N.Z., Boyd, F.R.Oxide Minerals in the Liqhobong Kimberlite , LesothoAmerican MINERALOGIST., Vol. 65, No. 7-8, PP. 631-638.LesothoMineralogy
DS1980-0071
1980
Boyd, F.R.Boyd, F.R., Danchin, R.V.Lherzolites, Eclogites and Megacrysts from Some Kimberlites of Angola.American Journal of Science (JACKSON MEMORIAL VOLUME), PP. 528-549.Angola, West AfricaPetrology
DS1980-0072
1980
Boyd, F.R.Boyd, F.R., Finnerty, A.A.Conditions of Origin of Natural Diamonds of Peridotite Affinity.Journal of Geophysical Research, Vol. 85, No. B12, DECE, BER 10TH. PP. 6911-6918.South Africa, RussiaMineralogy, Mineral Inclusions, Natural, Xenoliths
DS1980-0073
1980
Boyd, F.R.Boyd, F.R., Nixon, P.H.Discrete Nodules from the Kimberlites of East GriqualandCarnegie Institute Yearbook, FOR 1979, PP. 296-302.South AfricaPetrography, Xenoliths
DS1981-0087
1981
Boyd, F.R.Boctor, N.Z., Boyd, F.R.Oxide Minerals in a Layered Kimberlite Carbonate Sill from Benfontein South Africa.Contributions to Mineralogy and Petrology, Vol. 76, No. 3, PP. 253-259.South AfricaMineral Chemistry
DS1981-0096
1981
Boyd, F.R.Boyd, F.R., Nixon, P.H., Boctor, N.Z.Quenched Rocks of Mantle Origin from the Mzongwana Kimberlite Dike, Transkei, Southern Africa.Carnegie Institute Yearbook, FOR 1980, PP. 328-336.South Africa, BotswanaXenoliths, Petrography
DS1982-0104
1982
Boyd, F.R.Boctor, N.Z., Boyd, F.R.Petrology of Kimberlite from the Debruyn and Martin Mine, Bellsbank, South Africa.American MINERALOGIST., Vol. 67, PP. 917-925.South AfricaBlank
DS1982-0105
1982
Boyd, F.R.Boctor, N.Z., Boyd, F.R., Nixon, P.H.Carbonate Tuff from Melkfontein, East Griqualand, South Africa.Proceedings of Third International Kimberlite Conference, TERRA COGNITA, ABSTRACT VOLUME., Vol. 2, No. 3, P. 211, (abstract.).South AfricaKimberlite, Mineralogy
DS1982-0111
1982
Boyd, F.R.Boyd, F.R.Predicting the Occurrence of Diamondiferous KimberlitesIndiaqua., No. 33, PP. 31-34.South AfricaBlank
DS1982-0112
1982
Boyd, F.R.Boyd, F.R., Gurney, J.J.Low Calcium Garnets: Keys to Craton Structure and Diamond Chromiumystallization.Carnegie Institute Yearbook, FOR 1981, PP. 261-267.South Africa, Lesotho, Southwest Africa, NamibiaOrigin, Kimberlites
DS1982-0230
1982
Boyd, F.R.Gurney, J.J., Boyd, F.R.Mineral Intergrowths with Polycrystalline Diamonds from The Orapa Mine, Botswana.Carnegie Institute Yearbook, FOR 1981, PP. 267-273.BotswanaMineralogy
DS1983-0136
1983
Boyd, F.R.Boctor, N.Z., Boyd, F.R., Nixon, P.H.Pyroxenites, Eclogites, and Megacrysts in Kimberlite from The de Bruyn and Martin Mine, Bellsbank, South Africa.Carnegie Institute Yearbook, FOR 1982, PP. 346-349.South AfricaPetrology
DS1983-0141
1983
Boyd, F.R.Boyd, F.R., Jones, R.A., Nixon, P.H.Mantle Metasomatism: the Kimberley Dunites #1Carnegie Institute Yearbook, FOR 1982, PP. 330-336.South AfricaKimberley, Kampfersdam, Bultfontein, De Beers, Mineral Chemistry
DS1983-0142
1983
Boyd, F.R.Boyd, F.R., Nixon, P.H.Mantle Metasomatism; the Kimberley DunitesCarnegie Institute Yearbook, FOR 1982, PP. 330-336.South AfricaGenesis, Petrology
DS1983-0483
1983
Boyd, F.R.Nixon, P.H., Boyd, F.R., Boctor, N.Z.East Griqualand KimberlitesGeological Society STH, AFR. Transactions, Vol. 86, No. 3, PP. 221-236.South AfricaTectonics, Chemical Composition, Genesis
DS1984-0161
1984
Boyd, F.R.Boctor, N.Z., Nixon, P.H., Buckley, F., Boyd, F.R.Petrology of Carbonate Tuff from Melkfontein, East Griqualand, Southern Africa.Proceedings of Third International Kimberlite Conference, Vol. 1, PP. 75-82.South Africa, LesothoGenesis, Rare Earth Elements (ree), Mineral Chemistry
DS1984-0167
1984
Boyd, F.R.Boyd, F.R.Siberian Geotherm Based on Lherzolite Xenoliths from the Udachnaya Kimberlite, UssrGeology, Vol. 12, No. 9, SEPTEMBER PP. 528-530.Russia, South Africa, India, United States, Montana, Rocky Mountains, LesothoGeothermobarometry, Garnet
DS1984-0168
1984
Boyd, F.R.Boyd, F.R., Dawson, J.B., Smith, J.V.Granny Smith Diopside Megacrysts from the Kimberlites of The Kimberley Area and Jagersfontein South Africa.Geochimica Et Cosmochimica Acta, Vol. 48, No. 2, FEBRUARY PP. 381-384.South AfricaXenoliths, Petrography
DS1984-0169
1984
Boyd, F.R.Boyd, F.R., Jones, R.A., Nixon, P.H.Mantle Metasomatism: the Kimberley Dunites #2Geological Society of America (GSA), Vol. 16, No. 6, P. 453. (abstract.).South AfricaPetrography
DS1984-0170
1984
Boyd, F.R.Boyd, F.R., Nixon, P.H., Boctor, N.Z.Rapidly Crystallized Garnet Pyroxenite Xenoliths Possibly Related to Discrete Nodules.Contributions to Mineralogy and Petrology, Vol. 86, PP. 119-130.South AfricaMzongwana, Kimberlite, Mineral Chemistry, Textures, Analyses
DS1984-0278
1984
Boyd, F.R.Finnerty, A.A., Boyd, F.R.Evaluation of Thermobarometers for Garnet PeridotitesGeochimica Et Cosmochimica Acta., Vol. 48, No. 1, PP. 15-28.LesothoMineral Chemistry, Genesis, Thermobarometry
DS1985-0081
1985
Boyd, F.R.Boyd, F.R.The Old Cold Root of the Kaapvaal CratonGeological Society of America (GSA), Vol. 17, No. 3, FEBRUARY P. 152. (abstract.).South AfricaGarnet, Inclusions, Finsch, Kimberley
DS1985-0082
1985
Boyd, F.R.Boyd, F.R., Gurney, J.J., Richardson, S.H.Evidence for a 150-200 Km Thick Archaean Lithosphere from Diamond Inclusion Thermobarometry.Nature., Vol. 315, No. 6018, MAY 30TH. PP. 387-388.South AfricaInclusions, Garnet, Mineral Chemistry, Geobarometry, Analyses
DS1985-0187
1985
Boyd, F.R.Finnerty, A.A., Boyd, F.R.Refinements To, and Worldwide Applications of Garnet Peridotite Thermobarometers.Eos, Vol. 66, No. 46, NOVEMBER 12, P. 1131. (abstract.).GlobalExperimental Petrology
DS1985-0315
1985
Boyd, F.R.Jones, R.A., Boyd, F.R., Schulze, D.J.Glimmerite, Marid and Pkp Xenoliths from Kimberley Republic of South Africa.Geological Society of America (GSA), Vol. 17, No. 3, P. 163. (abstract.).South AfricaGeochemistry
DS1985-0497
1985
Boyd, F.R.Nixon, P.H., Boyd, F.R., Hawkesworth, C.Archaean Harzburgites with Garnet of Diamond Facies from Southern African Kimberlites.Geological Society of America (GSA), Vol. 17, No. 3, P. 186. (ASBTR.).South Africa, LesothoMineral Chemistry, Xenoliths
DS1986-0098
1986
Boyd, F.R.Boyd, F.R., Gurney, J.J.Diamonds and the African lithosphereScience, Vol. 232, April 25th. pp. 472-477South AfricaKaapvaal craton, inclusions, genesis, xenoliths, Diamond morphology
DS1986-0755
1986
Boyd, F.R.Smith, D., Boyd, F.R.Mechanical mixing of minerals in high T peridotite xenolithsEos, Vol. 67, No. 16, April 22, p. 394. (abstract.)South AfricaGenesis
DS1986-0756
1986
Boyd, F.R.Smith, D., Boyd, F.R.Compositional heterogeneities in minerals in peridotite nodulesProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 335-337South AfricaBlank
DS1987-0074
1987
Boyd, F.R.Boyd, F.R.High and low temperature garnet peridotite xenoliths and their possible relation to the lithosphere -asthenosphere boundary beneath southern AfricaMantle xenoliths, ed. P.H. Nixon, J. Wiley in pressSouth AfricaXenoliths, Geochemistry
DS1987-0075
1987
Boyd, F.R.Boyd, F.R.Lithologic heterogeneities in the upper mantle beneath Southern AfricaTerra Cognita, Conference abstracts Oceanic and Continental Lithosphere:, Vol. 7, No. 4, Autumn, abstract only p. 607South AfricaBlank
DS1987-0211
1987
Boyd, F.R.Finnerty, A.A., Boyd, F.R.Thermobarometry for garnet peridotite xenoliths: a basis for upper mantlestratigraphyMantle xenoliths, ed. P.H. Nixon, J. Wiley in pressSouth AfricaMantle Genesis, Xenoliths
DS1987-0530
1987
Boyd, F.R.Nixon, P.H., Boyd, F.R., Lee, D.C.Western Australia-xenoliths from kimberlites and lamproitesin: Nixon, P.H. ed. Mantle xenoliths, J. Wiley, pp. 281-286Australiap. 284 analyses Skerring and Ellendale kimberlite
DS1987-0532
1987
Boyd, F.R.Nixon, P.H., Van Calsteren, P.W.C., Boyd, F.R., Hawkesworth, C.J.Harzburgites with garnets of diamond facies from southernAfricankimberlitesin: Nixon, P.H. ed. Mantle xenoliths, J. Wiley, pp. 523-534South Africap. 527 analyses
DS1987-0692
1987
Boyd, F.R.Smith, D., Boyd, F.R.Compositional heterogeneities in a high temperature lherzolite nodule And implications for mantle processesMantle xenoliths, ed. P.H. Nixon, J. Wiley in pressGlobalMantle Genesis
DS1988-0077
1988
Boyd, F.R.Boyd, F.R.Origin and structure of continental cratonsCarnegie Institute Yearbook 1986-1987, pp. 97-100South AfricaKaapvaal
DS1988-0078
1988
Boyd, F.R.Boyd, F.R., Nixon, P.H.Low-Ca garnet harzburgites: origin and role in craton structureCarnegie Institute Annual Report of the Director of the Geophysical, No. 2102, issued Dec. 1988, pp. 8-13Russia, South AfricaAnalyses-garnet lherzolite, garnet harzburgite
DS1988-0427
1988
Boyd, F.R.Luth, R.W., Virgo, D., Boyd, F.R., Woodm B.J.Iron in mantle derived garnets: valence and structural stateCarnegie Institute Annual Report of the Director of the Geophysical, No. 2102, issued Dec. 1988, pp. 13-18South AfricaExperimental description
DS1989-0160
1989
Boyd, F.R.Boyd, F.R.Where do we go from here?Geological Society of Australia Inc. Blackwell Scientific Publishing, Special, No. 14, Vol. 2, pp. 1239-1251GlobalReview of conference, Ecologites/peridotites/ex
DS1989-0161
1989
Boyd, F.R.Boyd, F.R.Kaapvaal spinel peridotites: evidence of craton originá#1Carnegie Institution Year Book 88 1988-1989 (June), pp. 144-145South AfricaCraton -Kaapvaal, Peridotites
DS1989-0162
1989
Boyd, F.R.Boyd, F.R.Compositional distinction between oceanic and cratonic lithosphereEarth and Planetary Science Letters, Vol. 96, pp. 15-26South AfricaCraton, Mantle lithosphere
DS1989-0163
1989
Boyd, F.R.Boyd, F.R.Kaapvaal spinel peridotites: evidence of craton origin #2Carnegie Institution, Annual Report of the Director of the Geophysical, No. 2150, July 1-1988 -June 30, 1989 pp. 3-6South AfricaPeridotites, Craton -Kaapvaal
DS1989-0164
1989
Boyd, F.R.Boyd, F.R., Nixon, P.H.The origin of low-Ca garnet harzburgites and their relationship to diamondcrystallizationDiamond Workshop, International Geological Congress, July 15-16th. editors, pp. 4-7. AbstractSouth AfricaDiamond Genesis, Kaapvaal craton Harzburgi
DS1989-0551
1989
Boyd, F.R.Griffin, W.L., Smith, D., Boyd, F.R., Cousens, D.R., Ryan, C.G.Trace-element zoning in garnets from sheared mantlexenoliths.(Letter)Geochimica et Cosmochimica Acta, Vol. 53, No. 2, Feb. pp. 561-567AustraliaMantle-garnets, Mantle
DS1989-1410
1989
Boyd, F.R.Smith, D., Boyd, F.R.Compositional heterogeneities in minerals of sheared lherzolite inclusions from African kimberlitesGeological Society of Australia Inc. Blackwell Scientific Publishing, Special, No. 14, Vol. 2, pp. 709-724South AfricaMantle Metasomatism, Xenoliths
DS1989-1575
1989
Boyd, F.R.Walker, R.J., Carlson, R.W., Shirey, S.B., Boyd, F.R.Osmimum, Strontium, neodymium and lead isotope systematics of Southern african peridotite xenoliths: implications for the chemical evolution of subcontinental mantleGeochimica et Cosmochimica Acta, Vol. 53, pp. 1583-1595South Africa, BotswanaXenoliths, Mineral chemistry
DS1990-0960
1990
Boyd, F.R.Luth, R.W., Virgo, D., Boyd, F.R., Wood, B.J.Ferric iron in mantle derived garnetsContributions to Mineralogy and Petrology, Vol. 104, pp. 56-72GlobalMantle, Garnet analyses
DS1990-1165
1990
Boyd, F.R.Pearson, D.G., Boyd, F.R., Nixon, P.H.Graphite-bearing mantle xenoliths from the Kaapvaal Craton: Implications for graphite and diamond genesisCarnegie Institution Geophysical Laboratory Annual Report of the Director, No. 2200, pp. 11-19Southern Africa, LesothoGraphite, Diamond genesis
DS1991-0162
1991
Boyd, F.R.Boyd, F.R.Mantle metasomatism: evidence from a MARID-harzburgite compound xenolithCarnegie Institute Annual Report of the Director Geophysical Laboratory, No. 2250, pp. 18-22South Africa, MantleKimberley deposit data, Xenoliths
DS1991-0972
1991
Boyd, F.R.Lee, D.C., Boyd, F.R., Griffin, B.J., Reddicliffe, T.Coanjula diamonds, northern Territory, AustraliaProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 231-233AustraliaMicrodiamonds, Microscopy, diamond morphology
DS1991-1310
1991
Boyd, F.R.Pearson, D.G., Boyd, F.R., Field, S.W., Pasteris, J.D., HaggertyGraphite bearing peridotites from the Kaapvaal craton: their carbon isotopic compositions and implications for peridotite thermobarometryProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 323-325South Africa, LesothoKimberley, Jagersfontein, spectrometry, Carbon composition -table
DS1991-1314
1991
Boyd, F.R.Pearson, D.G., Shirey, S.B., Carlson, R.W., Boyd, F.R., Nixon, P.H.Rhenium-osmium isotope systematics in southern African and SiberanProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 329-331Southern Africa, RussiaGeochronology -Re/Os isotope, Kaapvaal xenoliths
DS1991-1360
1991
Boyd, F.R.Pokhilenko, N.P., Pearson, D.G., Boyd, F.R., Sobolev, N.V.Megacrystalline dunites and peridotites: hosts for Siberian diamondsCarnegie Institute Annual Report of the Director Geophysical Laboratory, No. 2250, pp. 11-18Russia, SiberiaDunites, Peridotites
DS1993-0150
1993
Boyd, F.R.Boyd, F.R., Pearson, D.G., Nixon, P.H., Mertzman, S.A.Low calcium garnet harzburgites from southern Africa: their relations to craton structure and diamond crystallizationContribution to Mineralogy and Petrology, Vol. 113, pp. 352-366South AfricaGarnet, Mineralogy
DS1993-0151
1993
Boyd, F.R.Boyd, F.R., Pearson, D.G., Pokhilenko, N.P., Mertzman, S.A.Cratonic mantle composition: evidence from Siberian xenolithsEos, Transactions, American Geophysical Union, Vol. 74, No. 16, April 20, supplement abstract p. 321Russia, SiberiaBulk composition, Mineral chemistry
DS1993-1247
1993
Boyd, F.R.Pokhilenko, N.P., Sobolev N.V., Boyd, F.R., Pearson, D.G., Shimizum N.Megacrystalline pyrope peridotites in the lithosphere of the Siberianplatform: mineralogy, geochemical pecularities and the problem of their origin.Russian Geology and Geophysics, Vol. 34, No. 1, pp. 1-12.Russia, Commonwealth of Independent States (CIS), SiberiaPyrope peridotites, Siberian Platform, Geochemistry
DS1994-0201
1994
Boyd, F.R.Boyd, F.R., Pearson, D.G., Olson Hoal, K.E., Hoal, B.G.Composition and age of Namibian peridotite xenolith: a comparison of cratonic and non cratonic lithosphere.Eos, Vol. 75, No. 16, April 19, p. 192.NamibiaXenoliths, Peridotites
DS1994-1347
1994
Boyd, F.R.Pearson, D.G., Boyd, F.R., Haggerty, S.E., Pasteris, J.D.The characterization and origin of graphite in cratonic lithosphericmantle: a petrological carbon isotope and Raman spectroscopic study.Contr. Mineralogy and Petrology, Vol. 116, No. 3, pp. 449-466.MantleGeochronology, Graphite
DS1994-1591
1994
Boyd, F.R.Shimizu, N., Boyd, F.R., Sobolev, N.V., Pokhilenko, N.P.Chemical zoning of garnets in peridotites and diamondsMineralogical Magazine, Vol. 58A, pp. 831-832. AbstractSouth Africa, Russia, YakutiaGeochemistry, mineral inclusions, Diamond inclusions
DS1995-0192
1995
Boyd, F.R.Boyd, F.R., Pokhilenko, N.P., Pearson, D.G., Sobolev, N.V.Peridotite xenoliths from the Udachnaya kimberlite pipeProceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 57-59.Russia, YakutiaXenoliths, Deposit -Udachnaya
DS1995-0270
1995
Boyd, F.R.Carlson, R.W, Shirey, S.B., Pearson, D.G., Boyd, F.R.The mantle beneath continentsCarnegie Institution Yearbook 93 for 1993-1994., pp. 109-119.South Africa, Russia, SiberiaMantle, Plumes, keels
DS1995-0804
1995
Boyd, F.R.Hoal, B.G., Hoal, K.E.O., Boyd, F.R., Pearson, D.G.Tectonic setting and mantle composition inferred from peridotite Gibeon kimberlite field, Namibia.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 239-241.NamibiaTectonics, Deposit -Gibeon area
DS1995-0805
1995
Boyd, F.R.Hoal, B.G., Hoal, R.E.O., Boyd, F.R., Pearson, D.G.Age constraints on crustal and mantle lithosphere beneath the Gibean kimberlite field, Namibia.South. African Journal of Geology, Vol. 98, No. 2, June pp. 112-118.NamibiaGeochronology, Deposit -Gibeon field
DS1995-1458
1995
Boyd, F.R.Pearson, D.G., Kelley, S.P., Pokhilenko, N.P., Boyd, F.R.Laser 40 Ar-39 Ar analyses of phlogopites from kimberlites and theirxenoliths: constraints eruptionProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 424-426.Russia, Yakutia, South AfricaGeochronology -eruption ages, Argon, Deposit -Mir, Udachnaya, Leningrad, Letseng, Kampfersda
DS1995-1459
1995
Boyd, F.R.Pearson, D.G., Meyer, H.O.A., Boyd, F.R., Shirey, S.B.Rhenium- Osmium (Re-Os) isotope evidence for late Archean stabilization of thick lithosphere mantle keel beneath Kirkland LakeProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 427-429.Ontario, Kirkland LakeGeochronology, Mantle keel
DS1995-1461
1995
Boyd, F.R.Pearson, D.G., Shirey, S.B., Carlson, R.W, Boyd, F.R.Rhenium- Osmium (Re-Os),samarium-neodymium (Sm-Nd) Rubidium-Strontium isotope evidence for thick Archean lithospheric mantle beneath the Siberian craton ....Geochimica et Cosmochimica Acta, Vol. 59, No. 3, pp. 959-977.Russia, SiberiaMantle geochemistry, geochronology, Metasomatism -multistage
DS1997-0120
1997
Boyd, F.R.Boyd, F.R., Pokhilenko, N.P., Finger, L.W.Composition of the Siberian Cratonic mantle: evidence from Udachnaya peridotite xenoliths.Contributions to Mineralogy and Petrology, Vol. 128, No. 2-3, pp. 228-246.RussiaSiberian Craton, Deposit - Udachnaya
DS1998-0153
1998
Boyd, F.R.Boyd, F.R.The origin of cratonic peridotites: a major element approach #1International Geology Review, Vol. 40, No. 9, Sept. pp. 755-764.MantleCraton, Petrology - geochemistry
DS1998-0154
1998
Boyd, F.R.Boyd, F.R., Pearson, D.R., Mertzman, S.A.Spinel facies peridotites from the Kaapvaal root7th International Kimberlite Conference Abstract, pp. 100-102.South Africa, LesothoPeridotites - spinel, Deposit - Premier, Kimberley, Letseng, Frank Smith, Wel
DS1998-0215
1998
Boyd, F.R.Carlson, R.W., Pearson, D.G., Boyd, F.R., Shirey, IrvineRegional age variation of the southern African mantle: significance for model lithospheric mantle formation..7th International Kimberlite Conference Abstract, pp. 135-137.South AfricaGeochronology, Craton - on and off ages
DS1998-0566
1998
Boyd, F.R.Hamilton, M.A., Pearson, D.G., Stern R.A., Boyd, F.R.Constraints on MARID petrogenesis: SHRIMP II uranium-lead (U-Pb) zircon evidence for pre-eruption Metasomatism..7th International Kimberlite Conference Abstract, pp. 296-8.South AfricaGeochronology, Deposit - KampfersdaM.
DS1998-0660
1998
Boyd, F.R.Irvine, G.J., Pearson, D.G., Carlson, R.W., Boyd, F.R.Platinum group element constraints on the origin of cratonic peridotites: a study of Kimberley xenoliths..7th International Kimberlite Conference Abstract, pp. 346-8.South AfricaXenoliths - platinum group elements (PGE), Deposit - Kimberley
DS1998-1133
1998
Boyd, F.R.Pearson, D.G., Carlson, R.W., Boyd, F.R., Shiry, NixonLithospheric mantle growth around cratons: a Rhenium- Osmium (Re-Os) isotope study of peridotite xenoliths East Griqualand.7th. Kimberlite Conference abstract, pp. 658-60.South AfricaCraton, Geochronology - xenoliths
DS1998-1340
1998
Boyd, F.R.Shimizu, N., Pokhilenko, N.P., Boyd, F.R., Pearson, D.Trace element characteristics of garnet dunites/harzburgites, host rocks for peridotite diamond7th International Kimberlite Conference Abstract, pp. 803-4.Russia, SiberiaMineral chemistry, Peridotite diamonds
DS1999-0664
1999
Boyd, F.R.Shimizu, N., Pokhilenko, N.P., Boyd, F.R., Pearson, D.Trace element characteristics of garnet dunites /harzburgites. Host rocks for Siberian peridotitic ..7th International Kimberlite Conference Nixon, Vol. 2, pp. 773-82.Russia, Siberia, YakutiaPeridotite - diamond, geochemistry, Deposit - Udachnaya
DS2000-0104
2000
Boyd, F.R.Boyd, F.R.The origin of cratonic peridotites: a major element approach #2In: Planetary Petrology and Geochemistry, Snyder, Ernst, pp. 5-14.Russia, Siberia, South AfricaCraton - xenolith bulk composition, Deposit - Premier, Kimberley
DS2003-0146
2003
Boyd, F.R.Boyd, F.R., Hoal, K.O., Hoal, B.G., Nicox, P.H., Pearson, D.G., Kingston, M.J.Garnet lherzolites from Louwrencia, Namibia: bulk sample compositions and P/T8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, AbstractNamibiaMantle petrology
DS200412-0193
2003
Boyd, F.R.Boyd, F.R., Hoal, K.O., Hoal, B.G., Nicox, P.H., Pearson, D.G., Kingston, M.J.Garnet lherzolites from Louwrencia, Namibia: bulk sample compositions and P/T relations.8 IKC Program, Session 6, AbstractAfrica, NamibiaMantle petrology
DS200412-1508
2004
Boyd, F.R.Pearson, D.G., irvine, G.J., Ionov, D.A., Boyd, F.R., Dreibus, G.E.The Re Os systematics and platinum group element fractionation during mantle melt extraction: a study of massif and xenolith perChemical Geology, Vol. 208, 1-4, pp. 29-59.Africa, Lesotho, Namibia, MoroccoGeochronology, mantle melt extraction
DS1998-0110
1998
Boyd, J.Ben Ismail, W., Mainprice, D., Barruol, G., Boyd, J.Lithospheric mantle anisotropy of the Kaapvaal Craton, from lattice preferred orientation analysis.7th International Kimberlite Conference Abstract, pp. 73-75.South AfricaTomography - seismic, Olivine
DS1995-0193
1995
Boyd, K.F.Boyd, K.F., Schumm, S.A.Geomorphic evidence of deformation in the northern part of the New Madrid seismic zone.United States Geological Survey (USGS) Prof. paper, No. 1538-R, 35p.Midcontinent, Illinois, ArkansasGeophysics -seismics, Mississippi Embayment
DS1993-0152
1993
Boyd, N.K.Boyd, N.K., Smithson, S.B.Moho in the Archean Minnesota gneiss terrane: fossil, alteration or layered intrusion? #1Geology, Vol. 23, No. 12, December pp. 1131-1134.MinnesotaGeophysics -seismics, Crust
DS1993-0153
1993
Boyd, N.K.Boyd, N.K., Smithson, S.B.Moho in the Archean Minnesota gneiss terrane: fossil, alteration or layered intrusion #2Geology, Vol. 21, No. 12, December pp. 1131-1134MinnesotaLayered intrusions, Geophysics -seismics
DS201807-1507
2018
Boyd, O.Levandowski, W., Herrmann, R.B., Briggs, R., Boyd, O., Gold, R.An updated stress map of the continental United States reveals heterogeneous intraplate stress. TectonicsNature Geoscience, Vol. 11, 6, pp. 433-437.United Statesgeodynamics

Abstract: Knowledge of the state of stress in Earth’s crust is key to understanding the forces and processes responsible for earthquakes. Historically, low rates of natural seismicity in the central and eastern United States have complicated efforts to understand intraplate stress, but recent improvements in seismic networks and the spread of human-induced seismicity have greatly improved data coverage. Here, we compile a nationwide stress map based on formal inversions of focal mechanisms that challenges the idea that deformation in continental interiors is driven primarily by broad, uniform stress fields derived from distant plate boundaries. Despite plate-boundary compression, extension dominates roughly half of the continent, and second-order forces related to lithospheric structure appear to control extension directions. We also show that the states of stress in several active eastern United States seismic zones differ significantly from those of surrounding areas and that these anomalies cannot be explained by transient processes, suggesting that earthquakes are focused by persistent, locally derived sources of stress. Such spatially variable intraplate stress appears to justify the current, spatially variable estimates of seismic hazard. Future work to quantify sources of stress, stressing-rate magnitudes and their relationship with strain and earthquake rates could allow prospective mapping of intraplate hazard.
DS200412-0194
2004
Boyd, O.S.Boyd, O.S., Jones, C.H., Sheehan, A.F.Foundering lithosphere imaged beneath the Southern Sierra Nevada, California.Science, No. 5684, July 30, p. 660-662.United States, CaliforniaGeophysics - MT
DS200512-0107
2005
Boyd, O.S.Boyd, O.S., Sheehan, A.F.Attenuation tomography beneath the Rocky Mountain Front: implications for the physical state of the upper mantle.American Geophysical Union, Geophysical Monograph, No. 154, pp. 361-378.United States,Wyoming, Colorado PlateauGeophysics - seismics, tectonics
DS201511-1826
2015
Boyd, O.S.Boyd, O.S., Smalley, R., Zeng, Y.Crustal deformation in the New Madrid seismic zone and the role of postseismic processes.Journal of Geophysical Research, Vol. 120, 8, pp. 5782-5803.United States, ArkansasGeophysics - seismics

Abstract: Global Navigation Satellite System data across the New Madrid seismic zone (NMSZ) in the central United States over the period from 2000 through 2014 are analyzed and modeled with several deformation mechanisms including the following: (1) creep on subsurface dislocations, (2) postseismic frictional afterslip and viscoelastic relaxation from the 1811–1812 and 1450 earthquakes in the NMSZ, and (3) regional strain. In agreement with previous studies, a dislocation creeping at about 4 mm/yr between 12 and 20 km depth along the downdip extension of the Reelfoot fault reproduces the observations well. We find that a dynamic model of postseismic frictional afterslip from the 1450 and February 1812 Reelfoot fault events can explain this creep. Kinematic and dynamic models involving the Cottonwood Grove fault provide minimal predictive power. This is likely due to the smaller size of the December 1811 event on the Cottonwood Grove fault and a distribution of stations better suited to constrain localized strain across the Reelfoot fault. Regional compressive strain across the NMSZ is found to be less than 3?×?10?9/yr. If much of the present-day surface deformation results from afterslip, it is likely that many of the earthquakes we see today in the NMSZ are aftershocks from the 1811–1812 New Madrid earthquakes. Despite this conclusion, our results are consistent with observations and models of intraplate earthquake clustering. Given this and the recent paleoseismic history of the region, we suggest that seismic hazard is likely to remain significant.
DS1997-0121
1997
Boyd, R.Boyd, R., et al.Anthropologic noble metal enrichment of top soil in the Monchegorsk area, Kola Pen. Northwest RussiaJournal of Geochemical Exploration, Vol. 58, No. 2-3, pp. 283-290Russia, Kola PeninsulaGeochemistry, metallogeny, Environment - metals
DS2002-0198
2002
Boyd, R.Boyd, R., Clements, B.The north Slave craton region of Nunavut: an emerging diamond districtProspectors and Developers Association of Canada (PDAC) Abstracts, 1/8p.Northwest Territories, NunavutNews item, Ashton Mining of Canada
DS2002-0199
2002
Boyd, R.Boyd, R., Clements, B.The North Slave and Otish Mountains regions, Nunuvut and Quebec: grass roots discoveries of significant ...Prospectors and Developers Association of Canada (PDAC) 2002, Abstr. 2p.Ontario, James Bay LowlandsGeology, overview
DS2003-0147
2003
Boyd, R.Boyd, R., Clement, B., Lucas, R., Birkett, T., Poirier G., Bertrand, P.The Diamondiferous Renard cluster, Otish Mountains region, QuebecGeological Association of Canada Annual Meeting, Abstract onlyQuebecGeology
DS200412-0195
2003
Boyd, R.Boyd, R., Clement, B., Lucas, R.,Birkett, T., Poirier, G., Bertrand, P.The Diamondiferous Renard cluster, Otish Mountains region, Quebec.Geological Association of Canada Annual Meeting, Abstract onlyCanada, QuebecGeology
DS200612-0160
2006
Boyd, R.Boyd, R.The Canadian diamond business - an overview.CIM Conference and Exhibition, Vancouver - Creating Value with Values, List of talks CIM Magazine, Feb. p. 77.CanadaOverview - Ashton
DS2003-0148
2003
Boyd, R.T.Boyd, R.T.Canadian diamonds: from pariah to princess in twenty yearsCordilleran Exploration Roundup, p. 79 abstract.CanadaNews item, Economics
DS200412-0196
2004
Boyd, R.T.Boyd, R.T.Evolution of the National Diamond Strategy.An update on legal issues and developments in the mining industry, PDAC and Natural Resource and Energy Law (O, March 10, 18p. ppt slidesCanada, Northwest Territories, Nunavut, QuebecLegal - overview
DS1987-0076
1987
Boyd, S.R.Boyd, S.R., Mattey, D.P., Pillinger, C.T., Milledge, H.J.Multiple growth events during diamond genesis: an integrated study of carbon and nitrogen isotopes and nitrogen aggregation state in coated stonesEarth and Planetary Science Letters, Vol. 86, pp. 341-353Democratic Republic of CongoMbuji Mayi
DS1987-0197
1987
Boyd, S.R.Exley, R.A., Boyd, S.R., Mattey, D.P., Pillindesly, C.T.Nitrogen isotope geochemistry of basaltic glasses- implications for mantle degasing and structureEarth and Planetary Sci. Letters, Vol. 81, No. 2-3, January pp. 163-174GlobalMantle genesis
DS1987-0447
1987
Boyd, S.R.Mattey, D.P., Exley, R.A., Boyd, S.R., Pillinger, C.T., MenziesCarbon isotopes in oceanic and continental lithosphereTerra Cognita, Conference abstracts Oceanic and Continental Lithosphere:, Vol. 7, No. 4, Autumn, abstract only p. 618GlobalBlank
DS1988-0079
1988
Boyd, S.R.Boyd, S.R.A study of carbon and nitrogen isotopes from the earth's mantlePh.D. Open University, 360p. available University of Microfilms $ 55.00Australia, Africa, Russia, United States, Zaire, Central AfricaSierra Leone, Angola, Botswana, Geochemistry, diamond
DS1988-0080
1988
Boyd, S.R.Boyd, S.R., Pillinger, C.T., Milledge, H.J., Mendelsson, M.J.Fractionation of nitrogen isotopes in a synthetic diamond of mixed crystal habitNature, Vol. 331, No. 6157, Feb. 18, pp. 604-607GlobalBlank
DS1989-1023
1989
Boyd, S.R.Milledge, H.J., Mendelssohn, J.J., Boyd, S.R., Pillenger, C.T.Infrared topography and carbon and nitrogen isotope distribution in natural and synthetic diamonds in relation to mantle processesDiamond Workshop, International Geological Congress, July 15-16th. editors, pp. 55-60. AbstractGlobalMantle, Diamond morphology, natur
DS1989-1162
1989
Boyd, S.R.Ozima, M., Zashu, S., Boyd, S.R.Noble gas isotopic composition in coated diamonds:representative of The upper and lower mantle?Diamond Workshop, International Geological Congress, July 15-16th. editors, pp. 80-82. AbstractDemocratic Republic of CongoMantle, Geochronology
DS1992-0155
1992
Boyd, S.R.Boyd, S.R., Pillinge, C.ET., Milledge, H.J., Seal, M.J.C-isotopic and N-isotopic composition and the infrared absorption spectraof coated diamonds-evidence regional uniformity of CO2-H2) rich fluids lithospheric mantleEarth and Planetary Science Letters, Vol. 108, No. 1-3, January pp. 139-150MantleCoated diamonds, Geochronology
DS1994-0202
1994
Boyd, S.R.Boyd, S.R., Pillinger, C.T.A preliminary study of 15N/14N in octahedral growth form diamondsChemical Geology, Vol. 116, No. 1-2, Sept. 1, pp. 43-60.GlobalDiamond morphology, Diamond -nitrogen
DS1994-0203
1994
Boyd, S.R.Boyd, S.R., Pineau, F., Javoy, M.Modelling the growth of natural diamondsChemical Geology, Vol. 116, No. 1-2, Sept. 1, pp. 29-42.GlobalDiamond morphology, Diamond -natural
DS1994-1014
1994
Boyd, S.R.Lee, D.C., Boyd, S.R., Griffin, B.J., Griffin, B.W, Reddicliffe, T.Coanjuta diamonds, Northern Territory, AustraliaProceedings of Fifth International Kimberlite Conference, Vol. 2, pp. 51-68.AustraliaDiamond morphology, Deposit -Coanjuta
DS1994-1890
1994
Boyd, S.R.Watt, G.R., Harris, J.W., Harte, B., Boyd, S.R.A high chromium corundum ruby inclusion in diamond from the Sao Luizalluvial mine, Brasil.Mineralogical Magazine, Vol. 58, No. 392, Sept. 490-493.BrazilDiamond inclusion
DS1995-1962
1995
Boyd, S.R.Van Heerden, L.A., Boyd, S.R., Pillinger, C.T.The carbon and nitrogen isotope characteristics of Argyle and Ellendalediamonds.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 225-227.AustraliaGeochronology, Deposit -Argyle, Ellendale
DS1995-1963
1995
Boyd, S.R.Van Heerden, L.A., Boyd, S.R., Pillinger, C.T.The carbon and nitrogen isotope characteristics of the Argyle and Ellendalediamonds, Western Australia.International Geology Review, Vol. 37, No. 1, Jan. pp. 39-50.AustraliaGeochronology, Deposit -Argyle, Ellendale
DS1995-1964
1995
Boyd, S.R.Van Heerden, L.A., Boyd, S.R., Pillinger, C.T., MilledgeThe fractionation of nitrogen and carbon isotope ratios in Western Australian diamonds.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 228-230.AustraliaGeochronology, Deposit -Argyle, Ellendale
DS1997-0122
1997
Boyd, S.R.Boyd, S.R.Determination of the ammonium content of potassic rocks and minerals by capacitance manometry: calibration...Chemical Geology, Vol. 137, No. 1-2, May 1, pp. 57-66.GlobalFTIR microscopes, mass spectrometry, Alkaline rocks
DS1998-0219
1998
Boyd, S.R.Cartigny, P., Boyd, S.R., Javoy, M.Nitrogen isotopes in peridotitic diamonds from Fuzian China: the mantlesignature.Terra Nova, Vol. 9, No. 4, pp. 175-179.ChinaMantle, Geochronology
DS200412-0197
2004
Boyd, S.R.Boyd, S.R., Pearson, D.G., Hoal, K.O., Hoal, B.G., Nixon, P.H., Kingston, M.J., Mertzman, S.A.Garnet lherzolites from Louwrensia, Namibia: bulk composition and P/T relations.Lithos, Vol. 77, 1-4, Sept. pp. 573-592.Africa, NamibiaGeothermometry, peridotite, Kaapvaal, mantle, lithosphe
DS1995-0194
1995
Boyd, T.Boyd, T.An outline of Global positioning systemsAustralian Journal of Mining, Feb. pp. 23-26AustraliaGPS systems -brief overview
DS1999-0088
1999
Boyd, T.Boyd, T., Hutchinson, R.Overview of Diamonds and Metals 29th. Annual Conference held Oct. 1998 inToronto. Prev. papers/abstracts listedThe Gangue, No. 60, pp. 8-11.GlobalConference - overview
DS1992-0156
1992
Boyd, T.J.Boyd, T.J.An annotated outline of GPS... Global positioning systemsPreview Tutorial, October pp, 15-26GlobalGPS Systems, NAVSTAR.
DS1998-0155
1998
Boyd, W.Boyd, W.Canadian diamond mining and exploration - the new billion dollar industryCanadian Gemologist, XIX, No. 2, Summer pp. 42-54.Canada, Northwest Territories, Alberta, OntarioDiamond exploration - brief overview, Production and marketing
DS1994-0204
1994
Boyd, W.F.Boyd, W.F.The story of Russian diamond occurrencesCanadian Gemologist, Vol. XV, No. 1, Spring pp. 8-13.RussiaDiamond occurrences, Brief overview
DS2000-0996
2000
Boyd, W.F.Wake-Walker, R., Wyndham, C., Boyd, W.F.DICAN - the Canadian government diamond valuator and Canada's role in the World diamond industry.Geological Association of Canada (GAC)/Mineralogical Association of, 1p. abstract.Northwest TerritoriesEconomics - marketing - brief, DICAN.
DS200612-0161
2006
Boyd, W.F.Boyd, W.F.Canadian diamonds - obscurity to center stage.Rocks and Minerals, Vol. 81, 4, pp. 278-283.Canada, Northwest Territories, NunavutHistory
DS201811-2557
2015
Boyd, W.F.Boyd, W.F., Alferova, M.S.Emeralds in Russia: the geological and gemology of the Malyshev mine.InColor, December pp. 78-87.Russiaemeralds
DS200512-0862
2005
Boyer, B.Pla Cid, J., Stoll Nardi, L.V., Gisbert, P.E., Merlet, C., Boyer, B.SIMS analyses on trace and rare earth elements in coexisting clinopyroxene and mica from minette mafic enclaves in potassic syenites crystallized under high pressure.Contributions to Mineralogy and Petrology, Vol. 148, 6, pp. 675-688.UHP - minettes
DS1985-0083
1985
Boyer, H.Boyer, H., Smith, D.C., Chopin, C., Lasnier, B.Raman Microprobe (rmp) Determinations of Natural and Synthetic Coesite.Physics Chem. Minerals, Vol. 12, No. 1, PP. 45-48.South Africa, NorwayEclogite, Roberts Victor, Westen Gneiss, Dora Maira, Brytting
DS2003-0149
2003
Boyer, L.P.Boyer, L.P., Hood, C.T., McCandless, T.E., Skelton, D.N., Tosdal, R.D.Volcanology of the Buffalo Hills kimberlites, Alberta, Canada8ikc, Www.venuewest.com/8ikc/program.htm, Session 1 POSTER abstractAlbertaKimberlite geology and economics, Volcanism
DS2003-0150
2003
Boyer, L.P.Boyer, L.P., Hood, C.T., McCandless, T.E., Skelton, D.N., Tosdal, R.M.Volcaniclastic kimberlites of the Buffalo Head Hills, Alberta, CanadaGeological Association of Canada Annual Meeting, Abstract onlyAlbertaPetrology
DS2003-0151
2003
Boyer, L.P.Boyer, L.P., McCandless, T.E., Tosdal, R.M., Russell, J.K.Diamondiferous volcanoclastics of the Buffalo Head Hills kimberlites, northern AlbertaGeological Society of America, Annual Meeting Nov. 2-5, Abstracts p.327.AlbertaPetrology
DS200412-0198
2003
Boyer, L.P.Boyer, L.P., Hood, C.T., McCandless, T.E., Skelton, D.N., Tosdal, R.M.Volcaniclastic kimberlites of the Buffalo Head Hills, Alberta, Canada.Geological Association of Canada Annual Meeting, Abstract onlyCanada, AlbertaPetrology
DS200412-0199
2003
Boyer, L.P.Boyer, L.P., McCandless, T.E., Tosdal, R.M., Russell, J.K.Diamondiferous volcanoclastics of the Buffalo Head Hills kimberlites, northern Alberta Canada.Geological Society of America, Annual Meeting Nov. 2-5, Abstracts p.327.Canada, AlbertaPetrology
DS201112-0101
2005
Boyer, L.P.Boyer, L.P.Kimberlite volcanic facies and eruption in the Buffalo Head Hills, Alberta Canada.Thesis: University of British Columbia Msc., 156p.Canada, AlbertaThesis - note availability based on request to author
DS1989-0479
1989
Boyer, S.E.Geiser, P.A., Boyer, S.E.Construction of geological cross sections: techniques,assumptions andmethodsGeology, Penrose Conference Report, Vol. 17, No. 4, April pp. 373-375GlobalMapping, Geol. cross sections
DS1994-0994
1994
Boyer, S.E.Lawton, T.F., Boyer, S.E., Schmitt, J.G.Influence of inherited taper on structural variability and conglomeratedistribution, Cordilleran fold and thrust belt, western United StatesGeology, Vol. 22, No. 4, April pp. 339-342Nevada, CordilleraStructure, Foreland basin
DS1995-0195
1995
Boyer, S.E.Boyer, S.E.Sedimentary basin taper as a factor controlling the geometry and advance of thrust beltsAmerican Journal of Science, Vol. 295, Dec. pp. 1220-1254Cordillera, Alberta, NevadaBasin, Thrust belts
DS1860-0836
1894
Boyes, L.Boyes, L.How the Diamonds Were DiscoveredCeres Pamphlet, (unpubl.), 3P.Africa, South Africa, Griqualand WestHistory
DS200412-0123
2004
Boyet, M.Bedini, R.M., Blichert-Toft, J., Boyet, M., Albarede, F.Isotopic constraints on the cooling of the continental lithosphere.Earth and Planetary Science Letters, Vol. 223, 1-2, June, 30, pp. 99-111.Africa, South AfricaGarnet peridotite xenoliths, radiometric ages, geotherm
DS200512-0108
2005
Boyet, M.Boyet, M., Carlson, R.W.142 Nd evidence for early (>4.53 Ga) global differentiation of the silicate Earth.Science, Vol. 309, July 22, pp. 576-581.MantleGeochronology - silicate
DS200612-0162
2006
Boyet, M.Boyet, M., Carlson, R.W.A new geochemical model for the Earth's mantle inferred from 146 Sm and 142 Nd systematics.Earth and Planetary Science Letters, Vol. 250, 1-2, Oct. 15, pp. 254-268.Pacific IslandsKimberlite, carbonatite, mantle composition
DS200612-0223
2006
Boyet, M.Carlson, R.W., Boyet, M.Long tern consequences of early Earth differentiation.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 6, abstract only.MantleLayering
DS200712-0146
2007
Boyet, M.Carlson, R.W., Boyet, M., Horan, M.Chondrite, barium, neodymium and Samarium isotopic heterogeneity and early Earth differentiation.Science, Vol. 316 May 25, pp. 1175-1178.MantleChondrite, Geochronology
DS201312-0746
2013
Boyet, M.Rizo, H., Touboul, M., Carlson, R.W., Boyet, M., Puchtel, I.S., Walker, R.J.Early mantle composition and evolution inferred from 142 ND and 182 W variations in Isua samples.Goldschmidt 2013, AbstractMantleMineralogy
DS201412-0204
2014
Boyet, M.Doucelance, R., Bellot, N., Boyet, M., Hammouda, T., Bosq, C.What coupled cerium and neodynium isotopes tell us about the deep source of oceanic carbonatites.Earth and Planetary Science Letters, Vol. 407, pp. 175-195.Europe, Cape Verde Islands, Africa, MoroccoCarbonatite
DS201503-0135
2015
Boyet, M.Bouhifd, M.A., Boyet, M., Cartier, C., Hammouda, T., Bofan-Casanova, N., Devidal, J.L., Andrault, D.Superchondritic Sm/Nd ratio of the Earth: impact of Earth's core formation.Earth and Planetary Science Letters, Vol. 413, March 1, pp. 158-166.MantleGeochronology

Abstract: This study investigates the impact of Earth's core formation on the metal-silicate partitioning of Sm and Nd, two rare-earth elements assumed to be strictly lithophile although they are widely carried by the sulphide phases in reducing material (e.g. enstatite chondrites). The partition coefficients of Sm and Nd (DSmDSm and DNdDNd) between molten CI and EH chondrites model compositions and various Fe-rich alloys (in the Fe-Ni-C-Si-S system) have been determined in a multi-anvil between 3 and 26 GPa at various temperatures between 2073 and 2440 K, and at an oxygen fugacity ranging from 1 to 5 log units below the iron-wüstite (IW) buffer. The chemical compositions of the run products and trace concentrations in Sm and Nd elements were determined using electron microprobe and laser ablation inductively coupled plasma-mass spectrometry. Our results demonstrate the non-fractionation of Sm and Nd during the segregation of the metallic phases: the initial Sm/Nd ratio of about 1 in the starting materials yields precisely the same ratio in the recovered silicate phases after the equilibration with the metal phases at all conditions investigated in this study. In addition, DSmDSm and DNdDNd values range between 10?310?3 and 10?510?5 representing a low solubility in the metal. An increase of the partition coefficients is observed with decreasing the oxygen fugacity, or with an increase of S content of the metallic phase at constant oxygen fugacity. Thus, based on the actual Sm and Nd concentrations in the bulk Earth, the core should contain less than 0.4 ppb for Sm and less than 1 ppb for Nd. These estimates are three orders of magnitude lower than what would be required to explain the reported 142Nd excess in terrestrial samples relative to the mean chondritic value, using the core as a Sm-Nd complementary reservoir. In other words, the core formation processes cannot be responsible for the increase of the Sm/Nd ratio in the mantle early in Earth history.
DS201707-1309
2017
Boyet, M.Bouhifd, M.A., Clesi, V., Boujibar, A., Cartier, C., Hammouda, T., Boyet, M., Manthilake, G., Monteux, J., Andrault, D.Silicate melts during the Earth's core formation.Chemical Geology, Vol. 461, pp. 128-139.Mantlemelting

Abstract: Accretion from primordial material and its subsequent differentiation into a planet with core and mantle are fundamental problems in terrestrial and solar system. Many of the questions about the processes, although well developed as model scenarios over the last few decades, are still open and much debated. In the early Earth, during its formation and differentiation into rocky mantle and iron-rich core, it is likely that silicate melts played an important part in shaping the Earth's main reservoirs as we know them today. Here, we review several recent results in a deep magma ocean scenario that give tight constraints on the early evolution of our planet. These results include the behaviour of some siderophile elements (Ni and Fe), lithophile elements (Nb and Ta) and one volatile element (Helium) during Earth's core formation. We will also discuss the melting and crystallization of an early magma ocean, and the implications on the general feature of core-mantle separation and the depth of the magma ocean. The incorporation of Fe2 + and Fe3 + in bridgmanite during magma ocean crystallization is also discussed. All the examples presented here highlight the importance of the prevailing conditions during the earliest time of Earth's history in determining the composition and dynamic history of our planet.
DS1995-0910
1995
Boyko, A.N.Kaminsky, F.V., Feldman, A.A., Varlamov, V.A., Boyko, A.N.Prognostication of primary diamond deposits #2Journal of Geochemical Exploration, Vol. 52, pp. 167-182.RussiaDiamond exploration, Area selection
DS1996-0553
1996
Boyko, S.A..Govorov, G.I., Vysotskiy, S.V., Boyko, S.A..First boninite find on Sakhalin IslandDoklady Academy of Sciences, Vol. 336, pp. 154-159Russia, Sakhalin IslandBoninite
DS201312-0289
2013
Boyko, V.S.Gainutdinov, R.V., Shiryaev, A.A., Boyko, V.S., Fedortchouk, Y.Extended defects in natural diamonds: an atomic force microscopy investigation.Diamond and Related Materials, Vol. 40, pp. 17-23.TechnologyDiamond morphology
DS1999-0089
1999
Boykova, A.Boykova, A.Moho discontinuity in central Balkan peninsula in the light of the geostatistical structure analysis.Phys. Earth. Plan. International, Vol. 114, No. 1-2, July 6, pp. 49-58.Russia, Balkan PeninsulaMantle, Discontinuity
DS1992-0157
1992
Boyle, A.P.Boyle, A.P.Simultaneous solution of geobarometers and geothermometers using a microcomputer spreadsheetComputers and Geosciences, Vol. 17, No. 10, pp. 1473-1480GlobalComputers, Program -spreadsheet geobarometry
DS1993-0154
1993
Boyle, D.R.Boyle, D.R., Cox, D.L., Vandebeek, R.R.Groundwater sampling methodology for mineral exploration in glaciated terrain using reverse circulation overburden drillingJournal of Geochemical Exploration, Vol. 49, No. 3, December pp. 213-231Ontario, QuebecOverburden drilling -review of techniques, Geochemistry
DS1860-0199
1873
Boyle, F.Boyle, F.To the Cape for Diamonds, a Story of Digging Experiences In south Africa with Comments and Criticisms.London: Chapman And Hall, 415P.Africa, South Africa, Cape ProvinceTravelogue
DS1860-0258
1876
Boyle, F.Boyle, F.The Savage Life. a Second Series of Camp NotesLondon: Chapman And Hall, 332P.Africa, South Africa, Cape ProvinceTravelogue
DS1860-0335
1880
Boyle, F.Boyle, F.Diamond Fields of South Africa. #1Belgravia Magazine., Vol. 7, P. 453.Africa, South Africa, GriqualandHistory
DS1860-0377
1882
Boyle, F.Boyle, F.Legends of My BungalowLondon: Chapman And Hall, 360P.Africa, South Africa, Cape ProvinceHistory
DS1860-0428
1884
Boyle, F.Boyle, F.On the BorderlandLondon: Chapman And Hall, 416P.Africa, South AfricaHistory
DS1859-0004
1672
Boyle, R.Boyle, R.Essay about the Origin and Virtue of GemsLondon:, GlobalDiamond jeweller
DS1989-0165
1989
Boynton, W.V.Boynton, W.V., et al.Geochemistry and mineralogy of rare earth elementsReviews in Mineralogy, Vol. 21, 350pBookRare earths, Geochemistry
DS1987-0537
1987
Boyzarsdaya, R.Novgorodova, M.I., Galuskin, Ye.V., Boyzarsdaya, R., Mokhov, A.V.Accessory minerals in lamprophyres of central Asia.(Russian)Izves.Akad. Nauk SSSR, Ser. Geol. (Russian), No. 4, pp. 15-27RussiaLamproite, Petrology
DS201112-0102
2011
Boz, D.M.Boz, D.M., Schulzki, J., Viladkar, S.G.Selected accessory minerals and their alteration types in the carbonatite breccias of the Amba Dongar diatreme.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterIndiaCarbonatite
DS201112-0103
2011
Boz, D.M.Boz, D.M., Schulzki, J., Viladkar, S.G.Selected accessory minerals and their alteration types in the carbonatite breccia of the Amba Dongar diatreme.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.10.IndiaSovite
DS201112-0104
2011
Boz, D.M.Boz, D.M., Schulzki, J., Viladkar, S.G.Selected accessory minerals and their alteration types in the carbonatite breccia of the Amba Dongar diatreme.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.10.IndiaSovite
DS200812-0133
2007
Bozdag, E.Bozdag, E., Trampert, J.On crustal corrections in surface wave tomography.Geophysical Journal International, in press availableMantleGeophysics - tomography
DS201012-0069
2010
Bozdag, E.Bozdag, E., Trampert, J.Assessment of tomographic mantle models using spectral element seismograms.Geophysical Journal International, Vol. 180, no. 3, pp. 1187-1199.MantleGeophysics - seismics
DS201212-0833
2012
Bozdag, E.Zhu, H., Bozdag, E., Peter, D., Tromp, J.Structure of the European upper mantle revealed by adjoint tomography.Nature Geoscience, Vol. 5, July, pp. 493-497.EuropeHotspots
DS1995-0977
1995
Bozhevolny, I.I.Klimenko, N.F., Bozhevolny, I.I.Forecast search model for kimberlite controlling zones in the Yakutian diamondiferous province.Proceedings of the Sixth International Kimberlite Conference Almazy Rossii Sakha abstract, p. 8.Russia, YakutiaLithosphere blocks, Zones -Tunguss, Olenyok, Vilyui, Markha
DS200412-2204
2004
Bozhillov, K.Zhang, J., Green, W.H., Bozhillov, K., Jin, Z.Faulting induced by precipitation of water at grain boundaries in hot subducting oceanic crust.Nature, Vol. 428, April 8, 633-636.MantleSubduction
DS2003-0339
2003
Bozhilov, K.N.Dobrzhinetskaya, L.F., Green, H.W., Bozhilov, K.N., Mitchell, T.E., Dickerson, R.M.Crystallization environment of Kazakhstan microdiamond: evidence from nanometricJournal of Metamorphic Geology, Vol. 21, 5, pp. 425-38.Russia, KazakhstanMineral inclusions
DS200412-0463
2003
Bozhilov, K.N.Dobrzhinetskaya, L.F., Green, H.W., Bozhilov, K.N., Mitchell, T.E., Dickerson, R.M.Crystallization environment of Kazakhstan microdiamond: evidence from nanometric inclusions and mineral associations.Journal of Metamorphic Geology, Vol. 21, 5, pp. 425-38.Russia, KazakhstanMicrodiamonds, mineral inclusions
DS200512-0238
2004
Bozhilov, K.N.Dobrzhinetskaya, L.F., Green, H.W., Renfro, A.P., Bozhilov, K.N., Spengler, D., Van Roemund, H.L.M.Precipitation of pyroxenes and Mg2SiO4 from majorite garnet: simulation of peridotite exhumation from great depth.Terra Nova, Vol. 16, 6, pp. 325-330.MantlePetrology - peridotite
DS200712-0639
2007
Bozhilov, K.N.Liu, L., Zhang, J., Green, H.W.II, Jin, Z., Bozhilov, K.N.Evidence of former stishovite in metamorphosed sediments, implying subduction to > 350 km.Earth and Planetary Science Letters, Vol. 263,3-4, Nov.30, pp. 180-191.MantleUHP
DS201808-1766
2018
Bozhilov, K.N.Machev, P., O'Bannon, E.F., Bozhilov, K.N., Wang, Q., Dobrzhinetskaya, L.Not all moissanites are created equal: new constraints on moissanite from metamorphic rocks of Bulgaria. Earth and Planetary Science Letters, Vol. 498, pp. 387-396.Europe, Bulgariamoissanite

Abstract: Terrestrial moissanite (SiC) is widely reported as an ultra-high pressure mineral occurring in kimberlites, diamonds and ultramafic/mafic rocks of mantle origin. However, the conditions of crystallization remain largely unknown. Moreover, dozens of SiC occurrences have been reported from continental crust sources such as granitoids, andesite-dacite volcanic rocks and their breccia, metasomatic and metamorphic rocks, and even limestones. The validity of many of these reports is still debated primarily due to possible contaminations from the widespread use of synthetic SiC abrasives in samples preparation. Indeed, reports of well-documented in-situ occurrences of moissanite in association with co-existing minerals are still scarce. The only condition of moissanite formation that is agreed upon is that extremely reducing media are required (e.g. 4.5-6 log units below the iron-wustite buffer). Here, we report the new occurrence of moissanite that was found in-situ within the garnet-staurolite-mica schists of Topolovgrad metamorphic group of Triassic age in Southern Bulgaria. The 10-300 ?m moissanite crystals are situated within 0.1-1.2 mm isolated clusters, filled with amorphous carbon and nanocrystalline graphite. Most of moissanite crystals are 15R (rhombohedral) and 6H (hexagonal) polytypes, and one prismatic crystal, found within them, exhibits unusual concentric polytypical zoning with core (15R), intermediate zone (6H) and rim (3C-cubic). Experimental data show that this type of polytypical zonation is likely due to a decrease in temperature (or/and pressure?) and changes in Si/C ratio. Indeed, amphibolite facies metamorphism (500-580?°C - garnet-staurolite zone) followed by a subsequent cooling during the retrograde stage of green schist facies metamorphism (?400-500?°C) could have provided a change in temperature. The SiC containing clusters exhibit evidence that they are pre-metamorphic, and we hypothesize that their protolith was a "lack shale" material likely rich in carbon, hydrocarbon and terrigenous silica. The latter served as a source of isolated chemically-reduced media, which is required for SiC formation. Other concepts to explain moissanite occurrences in metasedimentary rocks are also discussed. Importantly, our findings show that the formation conditions of moissanite are likely more variable than previously recognized.
DS1996-0735
1996
Bozhko, N.A.Khain, V.E., Bozhko, N.A.Historical geotectonics - Precambrian... Archean, Proterozoic, Pangea, Riphean, Gondwana, Laurasia...Balkema Publishing Russian Transactions Series, No. 116, 450pRussiaBook - table of contents, Geotectonics - Precambrian
DS2002-0200
2002
Bozhko, N.A.Bozhko, N.A., Postnikov, A.V., Shchipanski, A.A.Formation of the East European platform basement: a geodynamic modelDoklady Earth Sciences, Vol. 387,8, pp. 875-79.Europe, Kola PeninsulaTectonics
DS200912-0067
2009
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Author Index
A-An Ao+ B-Bd Be-Bk Bl-Bq Br+ C-Cg Ch-Ck Cl+ D-Dd De-Dn Do+ E F-Fn Fo+ G-Gh Gi-Gq Gr+ H-Hd He-Hn Ho+ I J K-Kg Kh-Kn Ko-Kq Kr+ L-Lh
Li+ M-Maq Mar-Mc Md-Mn Mo+ N O P-Pd Pe-Pn Po+ Q R-Rh Ri-Rn Ro+ S-Sd Se-Sh Si-Sm Sn-Ss St+ T-Th Ti+ U V W-Wg Wh+ X Y Z
 
 

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