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SDLRC - Scientific Articles all years by Author - Br+


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 - Br+
Posted/
Published
AuthorTitleSourceRegionKeywords
DS1990-0608
1990
Braak, C.J.F.Gruijter, J.J.de, Braak, C.J.F.Model-free estimation from spatial samples: are appraisal of classical sampling theoryMathematical Geology, Vol. 22, No. 4, May pp. 407-416GlobalGeostatistics, Sampling theory
DS2000-0105
2000
Braathen, A.Braathen, A., Nordgulen, Osmundsen, Andersen, SolliDevonian, orogen parallel, opposed extension in the central Norwegian Caledonides.Geology, Vol. 28, No. 7, July, pp. 615-18.NorwayBaltica, Laurentia, Tectonics
DS2002-0493
2002
Braathen, A.Gabirelsen, R.H., Braathen, A., Dehls, J., Roberts, D.Tectonic lineaments of NorwayNorsk Geologisk Tidsskrift, Vol. 82, No. 3, pp. 153-174.NorwayTectonics
DS1997-0889
1997
Brabant, S.Parson, R., Brabant, S.Structuring mining investment into Africa. Presentation by PriceWaterhouse.Miga Conference Held Denver June 3-5, 33p.AfricaMining, Economics - investment, not specific to diamonds
DS201807-1479
2018
Brabers, P.M.Brabers, P.M.Geophysical alluvial exploration using the Aquares resistivity method. ( mainly ports) two diamond application cases. Luderitz port, Sankura gravels DRC, SA Cape province PresentationSAIMM Diamonds - source to use 2018 Conference 'thriving in changing times'. June 11-13., pp. 73-88.Africa, Namibia, Democratic Republic of Congo, South Africageophysics - resistivity
DS201808-1727
2018
Brabers, P.M.Brabers, P.M.Geophysical alluvial exploration using the Aquares resistivity method. SAIMM Diamonds - source to use 2018 Conference 'thriving in changing times'. June 11-13., 18 ppts.Africa, Namibia, Democratic Republic of Congo, South Africageophysics
DS201902-0303
2018
Bracco Gartner, A.J.J.Nikogosian, I.K., Bracco Gartner, A.J.J., Bergen, M.J., Mason, P.R.D., Hinsbergen, D.J.J.Mantle sources of recent Anatolian intraplate magmatism: a regional plume or local tectonic origin?Tectonics, Vol. 37, 12, pp. 4535-4566.Asia, Turkeymagmatism

Abstract: We present an extensive study of rehomogenized olivine?hosted melt inclusions, olivine phenocrysts, and chromian spinel inclusions to explore the link between geodynamic conditions and the origin and composition of Pliocene-Quaternary intraplate magmatism in Anatolia at Kula, Ceyhan?Osmaniye, and Karacada?. Exceptional compositional variability of these products reveals early and incomplete mixing of distinct parental melts in each volcanic center, reflecting asthenospheric and lithospheric mantle sources. The studied primitive magmas consist of (1) two variably enriched ocean island basalt (OIB)?type melts in Kula; (2) both OIB?type and plume mid?ocean ridge basalt (P?MORB)?like melts beneath Toprakkale and Üçtepeler (Ceyhan?Osmaniye); and (3) two variably enriched OIB?type melts beneath Karacada?. Estimated conditions of primary melt generation are 23-9 kbar, 75-30 km, and 1415-1215 °C for Kula; 28-19 kbar, 90-65 km, and 1430-1350 °C for Toprakkale; 23-18 kbar, 75-60 km, and 1400-1355 °C for Üçtepeler; and 35-27 kbar, 115-90 km, and 1530-1455 °C for Karacada?, the deepest levels of which correspond to the depth of the lithosphere?asthenosphere boundary in all regions. Although magma ascent was likely facilitated by local deformation structures, recent Anatolian intraplate magmatism seems to be triggered by large?scale mantle flow that also affects the wider Arabian and North African regions. We infer that these volcanics form part of a much wider Arabian?North African intraplate volcanic province, which was able to invade the Anatolian upper plate through slab gaps.
DS202008-1370
2020
Bracco Gartner, A.J.J.Bracco Gartner, A.J.J., Davies, G.R., Koornneef, J.M.Sub-nanogram Pb isotope analysis of individual melt inclusions.Goldschmidt 2020, 1p. AbstractMantlemagmatism

Abstract: Precise analysis of 20xPb/204Pb ratios is challenging when the amount of Pb is limited by sample volume or elemental concentration. The current precision impedes meaningful analyses of analytes with sub-nanogram Pb contents, such as individual melt inclusions with typical diameters (<100 µm). Decreasing this lower limit whilst maintaining precision and accuracy is crucial for studies aiming to understand the composition and heterogeneity of melt source regions, and the effects of magma transport from the Earth’s interior. The preferred method for precise analysis of sub-nanogram Pb samples combines miniaturised ion-exchange separation, a Pb double spike, and thermal ionisation mass spectrometry (TIMS) with 10^13 ? amplifier technology. This approach allows for interference-free, instrumental mass fractionation-corrected isotope measurements, and therefore provides precision superior to in situ measurements. As a result, reliable analyses can be conducted on samples which contain only a few hundred picograms of Pb. The principal obstacle at the lower limit is the analytical blank, which usually adds a few pg Pb—and thus up to a few percent—to the sample of interest. This contribution may differ for the 207Pb-204Pb-spiked and unspiked runs of one sample, which in turn convolutes the algebraic inversion of the spike. It is therefore imperative to evaluate the magnitude, isotope composition, and homogeneity of the blanks, and constrain how the uncertainty and potential variability within these parameters affect the inversion. Here, we describe the optimised analytical techniques, and discuss the present feasibility and limitations in obtaining precise Pb isotope compositions of rock reference materials and olivine-hosted melt inclusions with sub-nanogram Pb contents. In addition, we discuss the effect of different blank contributions on double-spike analyses using numerical simulations, and evaluate the potential of accurate blank corrections. We find that the optimised technique allows accurate Pb analyses to be conducted on melt inclusions with >200 pg Pb, which will ultimately help to better constrain mantle heterogeneity beneath mid-ocean ridges, oceanic islands, and volcanic arcs.
DS1991-0791
1991
Brace, T.Jenner, G.A., Dunning, G.R., Malpas, J., Brown, M., Brace, T.Bay of Islands and Little Port complexes, revisited: age, geochemical and isotopic evidence confirm suprasubduction-zone originCanadian Journal of Earth Sciences, Vol. 28, No. 10, October pp. 1635-1652NewfoundlandOphiolites, Geochronology
DS1989-0183
1989
Bracewell, H.Brown, G., Bracewell, H., Snow, J.Gems of the Mud Tank carbonatiteThe Australian Gemologist, Vol. 17, No. 2, May pp. 52-59AustraliaCarbonatite, Mineralogy
DS1930-0017
1930
Bracewell, S.Bracewell, S.Report on the Buck Canister-oranapai Section of the Mazaruni Diamond Field. (with a Report by H.f. King.).British Guiana Geological Survey, PP. 1-18.Brazil, MazaruniKimberlite
DS1940-0026
1941
Bracewell, S.Bracewell, S.The Geomorphology Pf British GuianaGeology Magazine, Vol.78, Jan-Dec., pp; . 463-9.GlobalGeomorphology, Basement Complex
DS1940-0041
1942
Bracewell, S.Bracewell, S.Geology of the Waikuri District, Cuyuni RiverGeological Survey British Guiana, Bulletin. 18, p. 16.GlobalToroparou Creek
DS1996-0165
1996
Brack, W.Brack, W.Geological compilation report on the Temiscamingue diamond prospect Campeau Township. in EnglishQuebec Department of Mines, MRN GM 53989, 26p.Quebec, TemiscamingueExploration - assessment, Fairstar Exploration
DS1998-0156
1998
Brack, W.Brack, W.Diamond drill report on the Temiscamingue diamond prospect Campeau Township,Temiscamingue County.Quebec Department of Mines, GM 55658, 19p.QuebecExploration - assessment, Ditem Explorations Inc.
DS1998-0157
1998
Brack, W.Brack, W.Report on the Otish Mountains diamond prospect, north central QuebecQuebec Department of Mines, GM 56612, 56p.QuebecExploration - assessment, Ditem Explorations Inc.
DS1999-0090
1999
Brack, W.Brack, W.Report on the Otish Mountains diamond prospect, north central Quebec, Ditem Explorations Inc.Quebec Department of Mines, GM 56615, 116p.QuebecExploration - assessment, Ditem Explorations Inc.
DS1860-0620
1889
Brackett, R.N.Branner, J.C., Brackett, R.N.The Peridotite of Pike County, Arkansas Prarie CreekAmerican Journal of Science, SER. 3, Vol. 38, PP. 50-59. United States, Gulf Coast, Arkansas, PennsylvaniaMineralogy, Petrology
DS1940-0146
1947
Bradburn, 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
DS1992-1109
1992
Bradbury, J.Neil, C., Tykklainen, M., Bradbury, J.Coping with closure: an international comparison of mine town experiencesRoutledge London, 427p. $ 150.00Canada, Scandinavia, AustraliaBook -review, Mine closures -towns
DS1950-0264
1956
Bradbury, J.C.Clegg, K.E., Bradbury, J.C.Igneous Intrusive Rocks of Illinois and Their Economic Significance.Illinois Geological Survey Report Inv., No. 197, 19P.United States, Illinois, Great LakesRelated Rocks
DS1989-0092
1989
Bradbury, J.C.Baxter, J.W., Kisvarsanyi, E.B., Hagni, R.D., Bradbury, J.C.Precambrian and Paleozoic geology and ore deposits in the MidcontinentregionAmerican Geophysical Union (AGU) 28th. International Geological Congress Field Trip Guidebook, No. T 147, 68pMissouriGuidebook
DS202012-2207
2020
Bradby, J.Bradby, J.Diamond bling made within minutes.Sciencetimes.com, https://www.cnn.com /2020/11/19/world/ diamonds-room- temperature-scli -intl-scn/index.html Australiacarbon
DS1975-0132
1975
Braddoc.Mccallum, M.E., Smith, C.B., Burns, L.K., Eggler, D.H., Braddoc.Kimberlite Diatremes and Others Iron Mountain Area, Laramierange, Wyoming.Geological Society of America (GSA), Vol. 7, No. 5, P. 628 (abstract.).United States, Wyoming, State Line, Rocky MountainsBlank
DS1960-1008
1968
Braddock, W.A.Peterman, Z.E., Hedge, C.E., Braddock, W.A.Age of Precambrian Events in the Northeast Front Range, Colorado.Journal of Geophysical Research, Vol. 73, PP. 2277-2296.United States, Colorado, State Line, Rocky MountainsDiatreme
DS1989-0166
1989
Braddock, W.A.Braddock, W.A., Cole, J.C., Eggler, D.H.Geologic map of the Diamond Peak Quadrangle, LarimerCounty, Colorado and Albany County, WyomingUnited States Geological Survey (USGS) Map, GQ No. 1614, 1: 24, 000 $ 3.60Colorado, WyomingMap
DS1997-1193
1997
Braddocks, J.P.Van der Pluijm, B.A., Braddocks, J.P., Harris, J.H.Paleostress in cratonic North America: implications for deformation of continental interiors.Science, Vol. 277, No. 5327, Aug. 8, pp. 794-5.United States, CanadaCraton, Deformation, tectonics
DS201112-0105
2011
Braden, B.Braden, B.Frozen out! Why is NWT exploration slowing so drastically? grass roots explorers shun the NWT, discouraged by high cost, scant infrastructure, legalCanadian Mining Journal, May, pp. 38-42.Canada, Northwest TerritoriesHistory - legal
DS201212-0085
2012
Braden, B.Braden, B.Great gusto Diavik's wind project is world class in size and promise.Canadian Mining Journal, May pp. 44-49.Canada, Northwest TerritoriesDiavik - wind energy
DS201312-0092
2013
Braden, B.Braden, B.Safety rules the road to diamond mines.Canadian Mining Journal, April pp. 18-21.Canada, Northwest TerritoriesIce road
DS201412-0065
2014
Braden, B.Braden, B.Sask Rocks…. Veteran gem hunters get rewarded at remote North Arrow's Pikoo project… Canad's newest diamond district.Canadian Mining Journal, June/July pp. 14-17.Canada, SaskatchewanDeposit - Pikoo
DS201312-0563
2013
Braden, Z.Machado, G., Bilodeau, C., Takpanie, R., St.Onge, M., Rayner, N., Skipton, D., From, R., MacKay, C., Young, M., Creason, G., Braden, Z.Regional bedrock mapping, Hall Peninsula, Nunavut.Geoscience Forum 40 NWT, abstract only p. 26Canada, NunavutMapping
DS201212-0474
2012
Bradford, J.H.Miller, R.D., Bradford, J.H., Hilliger, K.Advances in near surface seismology and ground penetrating radar. ( not specific to diamonds)AGU, 487p. Approx. $ 150.00TechnologyBook - radar
DS200912-0068
2009
Bradley, A.Bradley, A.The diamond industry presents hige problems for buyers.Supply Management, Vol. 14, 3, pp. 22-27.GlobalEconomics
DS1993-0155
1993
Bradley, D.Bradley, D.Facing the reality of native titleAustralian Institute of Mining Bulletin, No. 4, August pp. 29-30AustraliaLegislation, Legal -natives
DS1993-0156
1993
Bradley, D.Bradley, D.Whats harder than diamondNew Scientist, Vol. 137, No. 1865, March 20, pp. 22-23GlobalDiamond synthesis
DS1994-0205
1994
Bradley, D.Bradley, D.Native title act 1993 - a guideAustralian Institute of Mining and Metallurgy (AusIMM) Bulletin, No. 2, March pp. 25-29AustraliaMining laws, Native title
DS201506-0257
2015
Bradley, D.Bradley, D.The promise of perovskite ( solar)Chemistry Views, May 5, 2p.TechnologyEnergy
DS201608-1392
2016
Bradley, D.Bradley, D.Improving rare earth extraction efficiency. Bastnasites ( structure and crystal properties)Journal of Physical Chemistry, 10.1002/ chemv.201600068TechnologyRare earths

Abstract: Scientists in the U.S. have provided a new understanding of the structure and crystal properties of the main mineral source of rare earth metals, bastnäsites. They are fluoro-carbonate minerals which contain ytterbium, lanthanum, and cerium, among other elements. The researchers used powder X-ray diffraction (XRD) and density functional theory (DFT) to reveal details of the minerals' structure and interfacial energy. The work could help in the design of new reagents for selective binding to mineral interfaces and could improve the recovery of rare metals by froth flotation, which is the major stage of ore beneficiation. Increasing flotation concentrate grades makes the subsequent leaching and rare earth separations more efficient and economic. Rare earth elements are increasingly important in modern technology - for electronics, catalysis, possible future quantum devices, and especially for clean energy applications like wind and solar energy, energy-efficient lighting, and electric vehicles. For example, neodymium and praseodymium are used in strong permanent magnets, lanthanum and cerium are used in batteries, metal alloys, petroleum refining, and catalysis, and ytterbium is a common material in phosphors for displays and in high-tech ceramics. These elements, which are defined as the fifteen lanthanides, as well as scandium and yttrium, are commonly found in the same ores. Despite what their name suggests, they are not actually rare, but they are difficult and costly to refine. As such, it is crucial that scientists and technologists optimize ore beneficiation to provide an enriched feedstock for the subsequent efficient extraction of these elements from the mined mineral ores in which they are found.
DS1989-0167
1989
Bradley, D.C.Bradley, D.C.Description and analysis of early faults based on geometry of faultbed-intersectionsJournal of Structural Geology, Vol. 11, No. 8, pp. 1011-1020GlobalStructure, Early faults
DS200912-0069
2008
Bradley, D.C.Bradley, D.C.Passive margins through Earth history. CratonsEarth Science Reviews, Vol. 91, 1-4, Dec. pp. 1-26.Mantle, RussiaTectonics, plate velocity, collision, supercontinents
DS201112-0106
2011
Bradley, D.C.Bradley, D.C.Secular trends in the geologic record and the supercontinent cycle.Earth Science Reviews, Vol. 108, 1-2, Sept. pp. 16-33.PangeaZircon detritals
DS201412-0066
2014
Bradley, D.C.Bradley, D.C.Global age distribution of detrital zircons, the supercontinent cycle and subduction flux through time.GAC-MAC Annual Meeting May, abstract 1p.MantleGeochronology
DS200812-0809
2008
Bradley, J.O'Brien, H.E., Bradley, J.New kimberlite discoveries in Kuusamo, northern Finland.9IKC.com, 3p. extended abstractEurope, FinlandDeposit - Kuusamo field
DS2002-0023
2002
Bradley, L-A.Allaoua Saadi, M.N., Machette,K.M., Haller,K.M., Dart, R.L., Bradley, L-A.Map and database of Quaternary faults and lineaments in BrazilU.s. Geological Survey, OF 02-0230 58p $ 76. http://pubs.usgs.gov/of/2002/ofr-BrazilBlank
DS200412-0019
2002
Bradley, L-A.Allaoua Saadi, M.N., Machette,K.M., Haller,K.M., Dart, R.L., Bradley, L-A., De Souza, A.M.P.D.Map and database of Quaternary faults and lineaments in Brazil.U.S. Geological Survey, OF 02-0230 58p $ 76.South America, BrazilMap - structure
DS1981-0097
1981
Bradley, S.D.Bradley, S.D., Mccallum, M.E.Lower Crustal Granulite Facies and Related Xenoliths from Colorado-Wyoming State Line Kimberlites.Geological Society of America (GSA), Vol. 13, No. 4, P. 192, (abstract.).United States, Colorado, Wyoming, State Line, Rocky MountainsBlank
DS1982-0113
1982
Bradley, S.D.Bradley, S.D., Mccallum, M.E.Lower Crustal Xenoliths from Colorado-Wyoming State Line Kimberlites.Proceedings of Third International Kimberlite Conference, TERRA COGNITA, ABSTRACT VOLUME., Vol. 2, No. 3, P. 236, (abstract.).United States, Colorado, Wyoming, State Line, Rocky MountainsBlank
DS1984-0171
1984
Bradley, S.D.Bradley, S.D.Granulite facies and related xenoliths from Colorado-WyomingkimberliteMsc. Colorado State Univ, Colorado, WyomingXenoliths, Granulite Facies
DS1984-0172
1984
Bradley, S.D.Bradley, S.D., Mccallum, M.E.Granulite Facies and Related Xenoliths from Colorado Wyoming Kimberlite.Proceedings of Third International Kimberlite Conference, Vol. 2, PP. 205-217.United States, State Line, California, Colorado, WyomingPetrography, Whole Rock Chemistry
DS1960-1098
1969
Bradley, W.E.Eggler, D.H., Larson, E., Bradley, W.E.Granites, Grusses and the Sherman Erosion Surface Southern Laramie Range, Colorado-wyoming.American Journal of Science, Vol. 267, No. 4, PP. 510-522.United States, Colorado, Wyoming, State Line, Rocky MountainsBlank
DS1960-0429
1964
Bradley, W.H.Bradley, W.H.Geology of the Green River Formation and Associated Eocene Rocks in the Southwestern Wyoming and Adjacent Parts of Colorado and Utah.United States Geological Survey (USGS) PROF. PAPER., No. 496-A, PP. 57-58.GlobalRocky Mountains, Leucite Hills, Leucite
DS1920-0373
1928
Bradley, W.W.Bradley, W.W.California's Commercial Non-metallic MineralsMining Congress Journal, Vol. 14, No. 9, SEPTEMBER PP. 669-718.United States, California, West CoastBlank
DS1930-0271
1938
Bradley, W.W.Bradley, W.W.California's Commercial MineralsMining Congress Journal, Vol. 24, No. 9, P. 19.United States, CaliforniaDiamond Occurrences
DS201607-1332
2016
Bradshaw, J.Bradshaw, J.The history of the Gondwana continent and the chronology of break up.IGC 35th., Session A Dynamic Earth 1p. AbstractMantleGondwana
DS1975-0965
1979
Bradshaw, J.Y.Brown, E.H., Bradshaw, J.Y.Phase Relations of Pyroxene and Amphibole in Greenstone, Blueschist and Eclogite of the Franciscan Complex, California.Contributions to Mineralogy and Petrology, Vol. 71, No. 1, PP. 67-83.GlobalEclogite, Kimberlite
DS1960-0796
1967
Bradshaw, N.Bradshaw, N.The Petrography of a Kimberlite from Kamangono Near Katiola, Ivory Coast.Overseas Geol. Institute Report, No. 287.GlobalPetrology
DS200712-0962
2007
Bradshaw, S.M.Scott, G., Bradshaw, S.M., Eksteen, J.J.The effect of microwave pretreatment on the liberation of a copper carbonatite ore after milling.International Journal of Mineral Processing, In press, availableTechnologyCarbonatite
DS201012-0071
2010
Brady, A.Brady, A.The kinship between lamprophyres and carbonatites: evidence from the south coast of Ireland.International Mineralogical Association meeting August Budapest, AbstractEurope, IrelandCarbonatite
DS200812-0134
2008
Brady, A.E.Brady, A.E., Moore, K.R.The role of carbonate in alkaline diatremic magmatism.9IKC.com, 3p. extended abstractEurope, Greenland, Russia, UzbekistanCarbonatite
DS200912-0070
2009
Brady, A.E.Brady, A.E., Moore, K.R.Using the composition of the carbonate phase to investigate the geochemical evolution of subvolcanic intrusions.alkaline09.narod.ru ENGLISH, May 10, 2p. abstractEurope, Ireland, Greenland, Russia, UzbekistanCarbonatite
DS201701-0004
2016
Brady, A.E.Broom-Fendley, S., Brady, A.E., Wall, F., Gunn, G., Dawes, W.REE minerals at the Songwe Hill carbonatite, Malawi: HREE enrichment in late stage apatite.Ore Geology Reviews, Vol. 81, pp. 23-41.Africa, MalawiCarbonatite

Abstract: Compared to all published data from carbonatites and granitoids, the fluorapatite compositions in the Songwe Hill carbonatite, determined by EPMA and LA ICP-MS, have the highest heavy (H)REE concentration of any carbonatite apatite described so far. A combination of this fluorapatite and the REE fluorocarbonates, synchysite-(Ce) and parisite-(Ce), which are the other principal REE bearing minerals at Songwe, gives a REE deposit with a high proportion of Nd and a higher proportion of HREE (Eu-Lu including Y) than most other carbonatites. Since Nd and HREE are currently the most sought REE for commercial applications, the conditions that give rise to this REE profile are particularly important to understand. Multiple apatite crystallisation stages have been differentiated texturally and geochemically at Songwe and fluorapatite is divided into five different types (Ap-0-4). While Ap-0 and Ap-1 are typical of apatite found in fenite and calcite-carbonatite, Ap-2, -3 and -4 are texturally atypical of apatite from carbonatite and are progressively HREE-enriched in later paragenetic stages. Ap-3 and Ap-4 exhibit anhedral, stringer-like textures and their REE distributions display an Y anomaly. These features attest to formation in a hydrothermal environment and fluid inclusion homogenisation temperatures indicate crystallisation occurred between 200-350 °C. Ap-3 crystallisation is succeeded by a light (L)REE mineral assemblage of synchysite-(Ce), strontianite and baryte. Finally, late-stage Ap-4 is associated with minor xenotime-(Y) mineralisation and HREE-enriched fluorite. Fluid inclusions in the fluorite constrain the minimum HREE mineralisation temperature to approximately 160 °C. A model is suggested where sub-solidus, carbonatite-derived, (carbo)-hydrothermal fluids remobilise and fractionate the REE. Chloride or fluoride complexes retain LREE in solution while rapid precipitation of apatite, owing to its low solubility, leads to destabilisation of HREE complexes and substitution into the apatite structure. The LREE are retained in solution, subsequently forming synchysite-(Ce). This model will be applicable to help guide exploration in other carbonatite complexes.
DS201707-1310
2017
Brady, A.E.Broom-Fendley, S., Brady, A.E., Horstwood, M.S.A., Woolley, A.R., Mtegha, J., Wall, F., Dawes, W., Gunn, G.Geology, geochemistry and geochronology of the Songwe Hill carbonatite, Malawi.Journal of African Earth Sciences, Vol. 134, pp. 10-23.Africa, Malawicarbonatite - Songwe Hill

Abstract: Songwe Hill, Malawi, is one of the least studied carbonatites but has now become particularly important as it hosts a relatively large rare earth deposit. The results of new mapping, petrography, geochemistry and geochronology indicate that the 0.8 km diameter Songwe Hill is distinct from the other Chilwa Alkaline Province carbonatites in that it intruded the side of the much larger (4 x 6 km) and slightly older (134.6 ± 4.4 Ma) Mauze nepheline syenite and then evolved through three different carbonatite compositions (C1–C3). Early C1 carbonatite is scarce and is composed of medium–coarse-grained calcite carbonatite containing zircons with a U–Pb age of 132.9 ± 6.7 Ma. It is similar to magmatic carbonatite in other carbonatite complexes at Chilwa Island and Tundulu in the Chilwa Alkaline Province and others worldwide. The fine-grained calcite carbonatite (C2) is the most abundant stage at Songwe Hill, followed by a more REE- and Sr-rich ferroan calcite carbonatite (C3). Both stages C2 and C3 display evidence of extensive (carbo)-hydrothermal overprinting that has produced apatite enriched in HREE (<2000 ppm Y) and, in C3, synchysite-(Ce). The final stages comprise HREE-rich apatite fluorite veins and Mn-Fe-rich veins. Widespread brecciation and incorporation of fenite into carbonatite, brittle fracturing, rounded clasts and a fenite carapace at the top of the hill indicate a shallow level of emplacement into the crust. This shallow intrusion level acted as a reservoir for multiple stages of carbonatite-derived fluid and HREE-enriched apatite mineralisation as well as LREE-enriched synchysite-(Ce). The close proximity and similar age of the large Mauze nepheline syenite suggests it may have acted as a heat source driving a hydrothermal system that has differentiated Songwe Hill from other Chilwa carbonatites.
DS202108-1275
2021
Brady, A.E.Broom-Fendley, S., Elliott, H.A.L., Beard, C.D., Wall, F., Armitage, P.E.B., Brady, A.E., Deady, A.E., Dawes, W.Enrichment of heavy REE and Th in carbonatite-derived fenite breccia.Geological Magazine, in press available Africa, Malawideposit - Songwe Hill

Abstract: Enrichment of the heavy rare earth elements (HREE) in carbonatites is rare as carbonatite petrogenesis favours the light (L)REE. We describe HREE enrichment in fenitized phonolite breccia, focusing on small satellite occurrences 1-2 km from the Songwe Hill carbonatite, Malawi. Within the breccia groundmass, a HREE-bearing mineral assemblage comprises xenotime, zircon, anatase/rutile and minor huttonite/thorite, as well as fluorite and apatite. A genetic link between HREE mineralization and carbonatite emplacement is indicated by the presence of Sr-bearing carbonate veins, carbonatite xenoliths and extensive fenitization. We propose that the HREE are retained in hydrothermal fluids which are residually derived from a carbonatite after precipitation of LREE minerals. Brecciation provides a focusing conduit for such fluids, enabling HREE transport and xenotime precipitation in the fenite. Continued fluid-rock interaction leads to dissolution of HREE-bearing minerals and further precipitation of xenotime and huttonite/thorite. At a maximum Y content of 3100 µg g?1, HREE concentrations in the presented example are not sufficient to constitute ore, but the similar composition and texture of these rocks to other cases of carbonatite-related HREE enrichment suggests that all form via a common mechanism linked to fenitization. Precipitation of HREE minerals only occurs where a pre-existing structure provides a focusing conduit for fenitizing fluids, reducing fluid - country-rock interaction. Enrichment of HREE and Th in fenite breccia serves as an indicator of fluid expulsion from a carbonatite, and may indicate the presence of LREE mineralization within the source carbonatite body at depth.
DS1991-0163
1991
Brady, J.Brady, J.Professional ethics and the public goodAustralian Institute of Mining and Metallurgy (AusIMM) Bulletin, No. 7, December pp. 65-67GlobalLegal, Ethics
DS1860-0884
1895
Brady, J.G.Brady, J.G.Diamonds in Alaska; March, 1895Letter To G.F. Kunz From Sitka Alaska., MARCH 2ND.United States, AlaskaDiamond Occurrence
DS201312-0923
2013
Braga, R.Tribuzio, R., Henjes-Kunst, F., Braga, R., Tiepolo, M.Boninite derived mafic ultramafic intrusives from northern Victoria Land ( Antarctica): implications for mantle source metasomatism.Goldschmidt 2013, 1p. AbstractAntarcticaBoninites
DS201706-1063
2017
Braga, R.Bianchini, G., Bodinier, J-L., Braga, R., Wilson, M.Crust-mantle and lithosphere-Asthenosphere boundaries.Geological Society of America, SPE 526, 200p.Mantlebook
DS201708-1567
2017
Braga, R.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
DS202107-1094
2021
Braga, R.Consuma, G., Aulbach, S., Braga, R., Martin, L.A.J., Tropper, P., Gerdes, A., Fiorentini, M.L.Multi-stage sulfur and carbon mobility in fossil continental subduction zones: new insights from carbonate-bearing orogenic peridotites. *** Not specific to diamondsGeochimica et Cosmochimica Acta, Vol. 306, pp. 143-170. pdfEurope, Italysubduction

Abstract: The volatile transfer in subduction zones and the role of sulfate as a vector for the mobilization of oxidized components from down-going slabs remain hotly debated issues. Orogenic spinel and garnet peridotite lenses from the Ulten Zone (Eastern Alps, Italy), exhumed as part of felsic metamorphic terranes in continental collision zones, bear witness to mass transfer processes in these pivotal environments. In this study, we carried out a multi-method investigation of mantle sulfides coexisting with four generations of carbonates, indicating coupled sulfur and carbon mobility throughout the peridotites’ metamorphic evolution as part of the Variscan subduction architecture. Detailed petrography, bulk rock measurements, in situ chemical and geochemical analyses of sulfides as well as Sr isotope analyses of associated clinopyroxene and amphibole are combined with the aim to constrain the origin, nature and effect of multiple C-O-H-S-bearing fluids and melts the peridotites interacted with. The first, pre-peak, metasomatic pulse (Stage 1) is represented by an H2S-CO2-bearing melt from the subduction-modified hot mantle wedge, which formed a pyroxenite layer hosting matrix pentlandite with ?34S of +2.77‰. Matrix carbonates occasionally occur in the coarse-grained peridotite under eclogite-facies conditions (Stage 2), with heavier ?34S (up to +3.43‰), radiogenic Sr (87Sr/86Srclinopyroxene > 0.7052) and elevated Pb abundances. These are ascribed to interaction with isotopically heavy melts carrying recycled crustal component, permissive of, but not requiring, involvement of oxidized S species. Conversely, isotopically lighter matrix pentlandite (?34S = ?1.62 to +0.67‰), and radiogenic Sr in amphibole (87Sr/86Sr = 0.7056) and associated dolomite (published data) from fine-grained garnet-amphibole peridotites may point to involvement of H2S-CO2-bearing crustal fluids, which variably equilibrated with the mantle before interacting with the peridotites. The post-peak Stage 3 marks the entrapment of peridotites into a tectonic mélange. Here, kelyphitization of garnet is catalyzed by further ingress of a S-bearing fluid (?34S = ?0.38‰), while carbonate veining with occasional sulfides bear witness to channelized fluid flow. Sulfide and amphibole grains in retrogressed spinel peridotites reveal the highest contents of fluid-mobile elements (As, Sb) and 87Sr/86Sramphibole up to 0.7074, suggesting late interactions with isotopically heavy crustal fluids at high fluid-rock ratios. Textural observations indicate that, during Stage 4, serpentinization of peridotites at low ƒS2 played an active role not only in CO2 release by conversion of dolomite to calcite + brucite intergrowths, but also in local removal of 32S during the final exhumation stage. Late channelized sulfur remobilization is evidenced by the serpentine + magnetite (±millerite ± calcite) vein carrying > 300 ppm S. Overall, the relatively narrow range of sulfur isotope composition (?34S = ?1.62 to +3.76‰) is indicative of limited interaction with isotopically heavy crustal liquids, and points to a subordinate role of subduction-derived sulfate throughout the extended fluid(melt)/rock evolution of the Ulten Zone peridotites, first in the mantle wedge and then as part of a tectonic mélange.
DS201312-0093
2013
Bragagni, A.Bragagni, A., Luguet, A., Pearson, D.G., Fonseca, R.O.C., Kjarsgaard, B.A.Insight on formation and evolution of cratonic mantle: Re-Os dating of single sulfides from Somerset mantle xenoliths ( Rae Craton) Canada.Goldschmidt 2013, AbstractCanada, NunavutGeochronolgy
DS201706-1064
2017
Bragagni, A.Bragagni, A., Luguet, A., Fonsecca, R.O.C., Pearson, D.G., Lorand, D.G., Nowell, G.M., Kjarsgaard, B.A.The geological record of base metal sulfides in the cratonic mantle: a microscale 187Os/188/Os study of peridotite xenoliths from Somerset Island, Rae craton,( Canada).Geochimica et Cosmochimica Acta, in press available 49p.Canada, Nunavut, Somerset Islandperidotite

Abstract: We report detailed petrographic investigations along with 187Os/188Os data in Base Metal Sulfide (BMS) on four cratonic mantle xenoliths from Somerset Island (Rae Craton, Canada). The results shed light on the processes affecting the Re-Os systematics and provide time constraints on the formation and evolution of the cratonic lithospheric mantle beneath the Rae craton. When devoid of alteration, BMS grains mainly consist of pentlandite + pyrrhotite ± chalcopyrite. The relatively high BMS modal abundance of the four investigated xenoliths cannot be reconciled with the residual nature of these peridotites, but requires addition of metasomatic BMS. This is especially evident in the two peridotites with the highest bulk Pd/Ir and Pd/Pt. Metasomatic BMS likely formed during melt/fluid percolation in the Sub Continental Lithospheric Mantle (SCLM) as well as during infiltration of the host kimberlite magma, when djerfisherite crystallized around older Fe-Ni-sulfides. On the whole-rock scale, kimberlite metasomatism is visible in a subset of bulk xenoliths, which defines a Re-Os errorchron that dates the host magma emplacement. The 187Os/188Os measured in the twenty analysed BMS grains vary from 0.1084 to >0.17 and it shows no systematic variation depending on the sulfide mineralogical assemblage. The largest range in 187Os/188Os is observed in BMS grains from the two xenoliths with the highest Pd/Ir, Pd/Pt, and sulfide modal abundance. The whole-rock TRD ages of these two samples underestimate the melting age obtained from BMS, demonstrating that bulk Re-Os model ages from peridotites with clear evidence of metasomatism should be treated with caution. The TRD ages determined in BMS grains are clustered around 2.8-2.7, ?2.2 and ?1.9 Ga. The 2.8-2.7 Ga TRD ages document the main SCLM building event in the Rae craton, which is likely related to the formation of the local greenstone belts in a continental rift setting. The Paleoproterozoic TRD ages can be explained by addition of metasomatic BMS during (i) major lithospheric rifting at ?2.2 Ga and (ii) the Taltson-Thelon orogeny at ?1.9 Ga. The data suggest that even metasomatic BMS can inherit 187Os/188Os from their original mantle source. The lack of isotopic equilibration, even at the micro-scale, allowed the preservation of different populations of BMS grains with distinct 187Os/188Os, providing age information on multiple magmatic events that affected the SCLM.
DS201710-2217
2017
Bragagni, A.Bragagni, A., Luguet, A., Fonseca, R.O.C., Pearson, D.G.,Lorand, J-P., Nowell, G.M., Kjarsgaard, B.A.The geological record of base metal sulfides in the cratonic mantle: a microscale 187Os/188Os study of peridotite xenoliths from Somerset Island, Rae Craton ( Canada).Geochimica et Cosmochimia Acta, Vol. 216, pp. 264-285.Canada, Nunavut, Somerset IslandGeochronology

Abstract: We report detailed petrographic investigations along with 187Os/188Os data in Base Metal Sulfide (BMS) on four cratonic mantle xenoliths from Somerset Island (Rae Craton, Canada). The results shed light on the processes affecting the Re-Os systematics and provide time constraints on the formation and evolution of the cratonic lithospheric mantle beneath the Rae craton. When devoid of alteration, BMS grains mainly consist of pentlandite + pyrrhotite ± chalcopyrite. The relatively high BMS modal abundance of the four investigated xenoliths cannot be reconciled with the residual nature of these peridotites, but requires addition of metasomatic BMS. This is especially evident in the two peridotites with the highest bulk Pd/Ir and Pd/Pt. Metasomatic BMS likely formed during melt/fluid percolation in the Sub Continental Lithospheric Mantle (SCLM) as well as during infiltration of the host kimberlite magma, when djerfisherite crystallized around older Fe-Ni-sulfides. On the whole-rock scale, kimberlite metasomatism is visible in a subset of bulk xenoliths, which defines a Re-Os errorchron that dates the host magma emplacement. The 187Os/188Os measured in the twenty analysed BMS grains vary from 0.1084 to >0.17 and it shows no systematic variation depending on the sulfide mineralogical assemblage. The largest range in 187Os/188Os is observed in BMS grains from the two xenoliths with the highest Pd/Ir, Pd/Pt, and sulfide modal abundance. The whole-rock TRD ages of these two samples underestimate the melting age obtained from BMS, demonstrating that bulk Re-Os model ages from peridotites with clear evidence of metasomatism should be treated with caution. The TRD ages determined in BMS grains are clustered around 2.8-2.7, ?2.2 and ?1.9 Ga. The 2.8-2.7 Ga TRD ages document the main SCLM building event in the Rae craton, which is likely related to the formation of the local greenstone belts in a continental rift setting. The Paleoproterozoic TRD ages can be explained by addition of metasomatic BMS during (i) major lithospheric rifting at ?2.2 Ga and (ii) the Taltson-Thelon orogeny at ?1.9 Ga. The data suggest that even metasomatic BMS can inherit 187Os/188Os from their original mantle source. The lack of isotopic equilibration, even at the micro-scale, allowed the preservation of different populations of BMS grains with distinct 187Os/188Os, providing age information on multiple magmatic events that affected the SCLM.
DS200812-0135
2008
Bragmann, G.A.E.A.Bragmann, G.A.E.A., Ryabchikov, I.A.D.A., Kogarko, L.A.N.A.Os isotope geochemistry of mantle peridotites from Sal Island, Cape Verde Archipelago.Doklady Earth Sciences, Vol. 419, 2, pp. 325-328.EuropeGeochronology
DS201809-2000
2018
Brahimi, S.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.
DS1986-0099
1986
Brahkov, Yu.P.Brahkov, Yu.P., Marshintsev, V.K.Crystallization trends of ilmenite from kimberlites of YakutiaDoklady Academy of Science USSR, Earth Science Section, Vol. 278, No. 1-6, April, pp. 158-161RussiaMineralogy
DS202202-0189
2022
Brahma, S.Brahma, S., Sahoo, S., Durai, P.R.First report of carbonatite from Gundlupet area, western Dharwar Craton, Karnataka, southern India.Journal of the Geological Society of India, Vol.98, pp. 35-40. Indiacarbonatite

Abstract: A new carbonatite body has been discovered from Gundlupet area, western Dharwar craton, southern India which is located at juncture of major shear zones namely, Kollegal shear zone to the east, Sargur shear zone to the west and Moyar shear zone to the south. The carbonatite and associated syenite have intruded into the peninsular gneissic complex. The southern margin of the syenite has a tectonic contact with the peninsular gneissic complex suggesting their emplacement is related to the splay shear of Moyar shear zone. The Gundlupet carbonatite is dominantly sövite with minor beforsite and iron rich carbonatite which are associated with phenocrystic magnetite, apatite, amphibole, pyroxene and monazite. Fenitisation is observed in local scale along the contact of carbonatite and syenite where metasomatic alterations took place to give rise to alkali amphibole and pyroxene rich rock. Geochemically, the carbonatite is characterised by high CaO content (48.86%-51.80%), P2O5 (0.35%-3.23%) and low SiO2 (3.09%-5.30%). The high Sr (5750-13445 ppm) content and low Ni, Cr, Zn and Cu content indicates that the melt has undergone some degree of fractionation before crystallization. Gundlupet carbonatite is enriched in LREE with values ranging from 5666 ppm to 7530 ppm and average LREE of 6248 ppm.
DS1984-0626
1984
Brahmam, N.K.Sakuntala, S., Brahmam, N.K.Diamond Mines Near RaichurGeological Society INDIA Journal, Vol. 25, No. 12, DECEMBER PP. 780-786.India, KarnatakaDiamond Occurrences
DS1975-1207
1979
Brahman, N.K.Sakuntala, S., Brahman, N.K.Some New Locales for Diamond Exploration in Andhra PradeshInstitute INDIAN PENINSULAR GEOLOGY, HYDERABAD., PP. 120-131.India, Andhra PradeshDiamond Prospecting, Occurrences
DS1975-0251
1976
Braile, L.W.Braile, L.W.Seismological Studies of the Crust and Upper Mantle in the Mid-continent Region.Geological Society of America (GSA), Vol. 8, No. 4, P. 467. (abstract.).GlobalMid-continent
DS1975-0529
1977
Braile, L.W.Hinze, W.J., Braile, L.W., Keller, G.R., Lidiak, E.G.A Tectonic Overview of the Central MidcontinentNational Technical Information Service NUREG 0382, 63P.GlobalMid-continent
DS1975-0556
1977
Braile, L.W.Lidiak, E.G., Keller, G.R., Braile, L.W., Hinze, W.J.Rifting in the Midcontinent #1Eos, Vol. 59, No. 4, PP. 227-228. (abstract.).GlobalMid-continent
DS1975-0762
1978
Braile, L.W.Hinze, W.J., Braile, L.W., Keller, G.R., Lidiak, E.G.Regional Tectonics of the Central Midcontinent, United StateGeological Association of Canada (GAC); Geological Society of America (GSA); MINERAL. Association CAN., Vol. 10, No. 7, P. 422. (abstract.).GlobalMid-continent
DS1975-0778
1978
Braile, L.W.Keller, G.R., Hinze, W.J., Braile, L.W., Lidiak, E.G.A Tectonic Overview of the Central Mid-continentEos, Vol. 59, No. 4, P. 230. (abstract.).GlobalMid-continent
DS1975-0798
1978
Braile, L.W.Lidiak, E.G., Keller, G.R., Braile, L.W., Hinze, W.J.Rifting in the Midcontinent #2Los Alamos Sci. Lab. Conference Proceedings, No. 7487, PP. 51-53. (abstract.).GlobalMid-continent
DS1975-0961
1979
Braile, L.W.Braile, L.W., Hinze, W.J., Keller, G.R., Lidiak, E.G.The Northeastern Extension of the New Madrid Seismic ZoneNational Technical Information Service NUREG CR/1014, PP. 74-99.GlobalMid-continent
DS1975-1098
1979
Braile, L.W.Keller, G.R., Braile, L.W., Morgan, P.Crustal Structure, Geophysical Models and Contemporary Tectonism of the Colorado Plateau.Tectonophysics, Vol. 61, PP. 131-147.United States, Colorado PlateauTectonics
DS1975-1231
1979
Braile, L.W.Soderberg, R.K., Keller, G.R., Braile, L.W., Hinze, W.J., et al.A Gravity and Tectonic Study of the Rough Creek Fault Zone And Related Features.National Technical Information Service NUREG CR/1014, PP. 134-164.GlobalMid Continent, New Madrid
DS1980-0074
1980
Braile, L.W.Braile, L.W., Hinze, W.J., Sexton, J.L., Keller, G.R., Lidiak, E.An Integrated Geophysical and Geological Study of the TectonNational Technical Information Service NUREG CR 0977, PP. 17-28.GlobalMid-continent
DS1980-0175
1980
Braile, L.W.Hinze, W.J., Braile, L.W., Keller, G.R., Lidiak, E.G.Models for Mid-continent TectonismIn: Continental Tectonics, Nat. Acad. Sciences Wash., PP. 73-83.GlobalMid-continent
DS1980-0287
1980
Braile, L.W.Reed, J.E., Hinze, W.J., Braile, L.W., Russell, D.R.Enhanced Gravity and Magnetic Anomaly Maps of the East Central Midcontintent.Geological Society of America (GSA), Vol. 12, No. 5, P. 254. (abstract.).GlobalMid-continent
DS1981-0236
1981
Braile, L.W.Keller, G.R., Lidiak, E.G., Hinze, W.J., Braile, L.W.The Role of Rifting in the Tectonic Development of the Midcontinent #1Lpi Contrib., No. 457, PP. 51-52.GlobalMid-continent
DS1982-0114
1982
Braile, L.W.Braile, L.W., Hinze, W.J., Sexton, J.L., Keller, G.R., Lidiak, E.Seismicity and Tectonics of the Midcontinent United StatesU.s. Nat. Science Foundation Proceedings of The Third International, Vol. 1, PP. 25-38.GlobalMid-continent
DS1982-0115
1982
Braile, L.W.Braile, L.W., Hinze, W.J., Sexton, J.L., Keller, G.R., Lidiak.A Tectonic Study of the Extension of the New Madrid Fault Zone Near its intersection with the 38th Parallel Lineament.National Technical Information Service NUREG CR/2741, 84P.GlobalMid-continent
DS1982-0116
1982
Braile, L.W.Braile, L.W., Keller, G.R., Hinze, W.J., Lidiak, E.G.An Ancient Rift Complex and its Relation to Contempory Seismicity in the New Madrid Seismic Zone.Tectonics, Vol. 1, No. 2, PP. 225-237.GlobalMid-continent
DS1982-0560
1982
Braile, L.W.Sexton, J.L., Hinze, W.J., Von frese, R.R.B., Braile, L.W.Long-wavelength Aeromagnetic Anomaly Map of the Conterminous United States.Geology, Vol. 10, No. 7, PP. 364-369.GlobalMid-continent, Mississippi Embayment, Geophysics, Magsat
DS1982-0623
1982
Braile, L.W.Von frese, R.R.B., Hinze, W.J., Braile, L.W.Regional North American Gravity and Magnetic Anomaly Correlations.Roy. Astron. Soc. Geophys. Journal, Vol. 69, PP. 745-761.United States, CanadaRegional Geophysics
DS1983-0143
1983
Braile, L.W.Braile, L.W., Hinze, W.J., Vonfrese, R.R.B., Keller, G.R.Seismic Properties of the Crust and Uppermost Mantle of North America.National Technical Information Service NASA CR-175134, 48P.GlobalMid-continent
DS1983-0305
1983
Braile, L.W.Hinze, W.J., Braile, L.W., Keller, G.R., Lidiak, E.G.Geophysical Geological Studies of Possible Extensions of The New Madrid Fault Zone.National Technical Information Service NUREG/CR 3174-V1, 101P.GlobalMid-continent
DS1983-0307
1983
Braile, L.W.Hinze, W.J., Lidiak, E.G., Reed, J.E., Keller, E.G., Braile, L.W.Geologic Significance of Regional Gravity and Magnetic Anomalies in the East Central Midcontinent.Geophysics, Vol. 48, No. 4, P. 449. (abstract.).GlobalMid-continent
DS1983-0350
1983
Braile, L.W.Keller, G.R., Lidiak, E.G., Hinze, W.J., Braile, L.W.The Role of Rifting in the Tectonic Development of the Midcontinent, Usa #2Tectonophysics, Vol. 94, PP. 391-412.GlobalMid-continent
DS1986-0100
1986
Braile, L.W.Braile, L.W., Hinze, W.J., Keller, G.R., Lidiak, E.G., Sexton, J.L.Tectonic development of the new Madrid rift complex Mississippi North AmericaTectonophysics, Vol. 131, No. 1/2, November 15, pp. 1-22MidcontinentTectonics
DS1986-0725
1986
Braile, L.W.Sexton, J.L., Braile, L.W., Hinze, W.J., Campbell, M.J.Seismic reflection profiling studies of a buried Precambrian rift beneath the Wabash Valley fault zoneGeophysics, Vol. 51, No. 3, March pp. 640-660GlobalMississippi embayment, Geophysics
DS1988-0307
1988
Braile, L.W.Hinze, W.J., Braile, L.W., Keller, G.R., Lidiak, E.G.Models for midcontinent tectonism: an updateReviews of Geophysics, Vol. 26, No. 4, November pp. 699-717Arkansas, MidcontinentGeophysics, Tectonics
DS1989-0168
1989
Braile, L.W.Braile, L.W., Hinze, W.J.Structure and tectonics of the MidcontinentGeological Society of America (GSA) North Central Section, Notre Dame Indiana April, Symposia being heldMidcontinentStructure, Ad in GSA News Jan 89 on
DS1989-0757
1989
Braile, L.W.Keller, G.R., Braile, L.W., McMechan, G.A., Thomas, W.A., HarderPaleozoic continent-ocean transition in the Ouachita Mountains imaged from PASSCAL wide angle seismic reflection- refractiondataGeology, Vol. 17, No. 2, February pp. 119-122Arkansas, LouisianaTectonics
DS1990-0232
1990
Braile, L.W.Braile, L.W., et al.Preliminary new models of the crustal structure beneath the Kenya Rift From the KRISP 90 seismic refraction profilesEos, Vol. 71, No. 43, October 23, p. 1450 AbstractKenyaGeophysics -seismics, Tectonics
DS1990-0701
1990
Braile, L.W.Hinze, W.J., Braile, L.W., Chandler, V.W.A geophysical profile of the southern margin of The midcontinent Rift system in western Lake SuperiorTectonics, Vol. 9, No. 2, April pp. 303-310MidcontinentGeophysics, Midcontinent Rift
DS1995-0023
1995
Braile, L.W.Allen, D.J., Braile, L.W., Hinze, W.J., Mariano, J.The midcontinent rift system United States (US): a major Proterozoic continental riftContinental Rifts: evolution, structure, tectonics, No. 25, pp. 375-408Michigan, Wisconsin, Kansas, Lake Superior regionGeophysics - seismics, gravity, Structure
DS1995-0024
1995
Braile, L.W.Allen, D.J., Braile, L.W., Hinze, W.J., Mariano, J.The midcontinent rift system United States (US): a major Proterozoic continental riftContinental Rifts: evolution, structure, tectonics, No. 25, pp. 375-408.Michigan, Wisconsin, Kansas, Lake Superior regionGeophysics - seismics, gravity, Structure
DS1995-0097
1995
Braile, L.W.Baldridge, W.S., Keller, G.R., Braile, L.W.Continental rifting: a final perspectiveContinental Rifts: evolution, structure, tectonics, No. 25, pp. 453-461MantleMagmatism, mantle plumes, MOHO, Tectonics
DS1995-0098
1995
Braile, L.W.Baldridge, W.S., Keller, G.R., Braile, L.W.Continental rifting: a final perspectiveContinental Rifts: evolution, structure, tectonics, No. 25, pp. 453-461.MantleMagmatism, mantle plumes, MOHO, Tectonics
DS1995-0196
1995
Braile, L.W.Braile, L.W., Keller, G.R., Mueller, S., Prodehl, C.Methods of investigation: seismic techniquesContinental Rifts: evolution, structure, tectonics, No. 25, pp. 61-92North AmericaSeismics -reflection, refraction
DS1995-0197
1995
Braile, L.W.Braile, L.W., Keller, G.R., Mueller, S., Prodehl, C.Methods of investigation: seismic techniquesContinental Rifts: evolution, structure, tectonics, No. 25, pp. 61-92.North AmericaSeismics -reflection, refraction
DS1995-0198
1995
Braile, L.W.Braile, L.W., Keller, G.R., Wendlandt, R.F., Morgan, P.The East African rift systemContinental Rifts: evolution, structure, tectonics, No. 25, pp. 213-232Kenya, Ethiopia, East AfricaGeophysics, Basin structure
DS1995-0803
1995
Braile, L.W.Hinze, W.J., Allen, D.J., Braile, L.W., Mariano, J.The Midcontinent rift system: an overviewBasement Tectonics 10, held Minnesota Aug 92, pp. 3-6.MidcontinentTectonics
DS1999-0583
1999
Braile, L.W.Ravat, D., Lu, Z., Braile, L.W.Velocity density relationships and modeling the lithospheric density variations of the Kenya Rift.Tectonophysics, Vol. 301, No. 3-4, Jan. 30, pp. 225-40.KenyaTectonics - rifting, Lithosphere
DS1982-0117
1982
Braille, L.W.Braille, L.W., Hinze, W.J., Vonfrese, R.R.B.Gravity and Magnetic Anomaly Dat a AnalysisNational Technical Information Service NASA CR 169504, 1P.United StatesMid-continent, Geophysics
DS1991-0164
1991
Braille, L.W.Braille, L.W.Seismic studies of the Earth's crustReviews of Geophysics, Vol. 29, pt. 2, pp. 680-687.supplement SeismologyGlobalMantle, Geophysics -seismics
DS201012-0586
2010
Braitenberg, C.Pinto, L.G.R.,Banik de Padua, M., Ussami, N., Vitorello, I., Padilha, A.L., Braitenberg, C.Magnetotelluric deep soundings, gravity and geoid in the south Sao Francisco craton: geophysical indicators of cratonic lithosphere rejuvenation and underplating.Earth and Planetary Science Letters, Vol. 297, pp. 423-434.South America, BrazilCarbonatite
DS201012-0633
2010
Braitenberg, C.Rodrigues Pinto, L.G., Banik de Padua, M., Ussami, N., Vitorello, I., Lopes Padhilha, A., Braitenberg, C.Magnetotelluric deep soundings, gravity and geoid in the south Sao Francisco craton: geophysical indicators of cratonic lithosphere rejuvenation and crustal underplating.Earth and Planetary Science Letters, Vol. 297, 3-4, pp. 423-434.South America, BrazilGeophysics - magnetotellurics
DS201012-0634
2010
Braitenberg, C.Rodrigues Pinto, L.G., Banik de Padua, M., Ussami, N., Vitorello, I., Lopes Padhilha, A., Braitenberg, C.Magnetotelluric deep soundings, gravity and geoid in the south Sao Francisco craton: geophysical indicators of cratonic lithosphere rejuvenation and crustal underplating.Earth and Planetary Science Letters, Vol. 297, 3-4, pp. 423-434.South America, BrazilGeophysics - magnetotellurics
DS201904-0721
2019
Braithwaite, J.Braithwaite, J., Stixrude, L.Melting of CaSiO3 perovskite at high pressure.Geophysical Research Letters, Vol. 46, 4, pp. 2037-2044.Mantlemelting

Abstract: Silicate melting is a major agent of thermal and chemical evolution of the Earth and other rocky planets. The melting temperature of Calcium silicate perovskite, a mineral that exists in Earth's lower mantle, is unknown over most of the pressure range that occurs in the mantle of Earth and super?Earth exoplanets. We use advanced quantum mechanical simulations to predict the melting temperature of this material. We find that the melting temperature increases with increasing pressure but at a rate that diminishes continuously. The liquid and crystal have very similar volumes in the deep portions of planetary mantles, supporting the view that crystals may float at great depth.
DS2001-0131
2001
Braithwaite, R.Braithwaite, R.Exploration drillingMining Annual Review, 5p.GlobalExploration drilling - technology, Overview - brief
DS1990-0233
1990
Braithwaite, R.W.Braithwaite, R.W.Importance of borehole surveying for mineral exploration, borehole planning and prospect evaluationTransactions of the Institute of Mining and Metallurgy (IMM), Vol. 99, Sect. A., pp. A110-A113GlobalBorehole survey tools, Methodology
DS200612-1169
2006
Brajkovic, A.Rolandi, V., Brajkovic, A., Adamo, I., Landonio, M.Diamonds from Udachnaya pipe, Yakutia. Their morphology, optical and Raman characteristics, FTIR and CL features.Australian Gemmologist, Vol. 22, no. 9 Jan-Mar, pp.RussiaDiamond morphology
DS201012-0072
2009
Brajkovic, A.Brajkovic, A., Rolandi, V., Scotti, R.Argyle type 1a brown diamonds gemmological properties FTIR, UV-VIS, Cl and ESR features.Australian Gemmologist, Vol. 23, 12, p.AustraliaDeposit - Argyle
DS200712-0191
2006
Brake, I.Clark, M.E., Brake, I., Huls, B.J., Smith, B.E., Yu, M.Creating value through application of flotation science and technology. ( mentions BHP diamonds)Minerals Engineering, Vol. 19, 5-6, May-July pp. 758-765.TechnologyMineral processing
DS1986-0101
1986
Brakfogel, F.F.Brakfogel, F.F., Belov, E.N., Fainshtein, G.Kh., et al.Geology of the upper Paleozoic diamond bearing formations of TunguskaTransactions of the Institute of Institute Geologiya i Geofizika Akademii Nauk, Vol. 646, pp. 93-122RussiaBlank
DS1995-0112
1995
Brakfogel, F.F.Barton, E.S., Brakfogel, F.F., Williams, I.S.uranium-lead (U-Pb) (U-Pb) zircon age for carbonatite and alkali picrite pipes Or to Yiargafield.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 37.Russia, YakutiaCarbonatite, Deposit -Orto-Yiarga
DS1995-2115
1995
Brakfogel, F.F.Zaitsev, A.I., Safronov, A.F., Brakfogel, F.F.Rubidium strontium isotope geochemistry of kimberlites and deep seated xenoliths of the Kharamai field.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 678-679.Russia, Siberia, AnabarGeochemistry, Deposit -Kharamai region
DS1995-0958
1995
Brakhfogel, F.E.Kinny, P.D., Griffin, B.J., Brakhfogel, F.E.SHRIMP uranium-lead (U-Pb) (U-Pb) ages of perovskite and zircon from Yajutian kimberlitesProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 275-276.Russia, YakutiaGeochronology -SHRIMP, Deposit -Udachnaya, Polayrnaya, Dalnaya
DS1970-0736
1973
Brakhfogel, F.F.Koval'skiy, V.V., Brakhfogel, F.F., Nikishov, K.N.Cambrian Fauna in Xenoliths from Kimberlite Pipes of the East Flank of the Anabar Uplift.Doklady Academy of Science USSR, Earth Science Section., Vol. 211, No. 1-6, PP. 101-104.RussiaKimberlite
DS1995-0199
1995
Brakhfogel, F.F.Brakhfogel, F.F., Zaitsev, A.I., Nenashev, N.I.Isotopic dating of kimberlite and related rocks in the N-E the SiberianPlatformProceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 63-65.Russia, YakutiaGeochronology
DS1996-1288
1996
Brakhfogel, F.F.Shamshina, E.A., Brakhfogel, F.F.The age of kimberlitic magmatites of Yakutia and indicator minerals in sedimentary northeast Siberian PlatformInternational Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 387.Russia, SiberiaAlluvials, Geochronology
DS201112-0477
2011
BramJanse, A.J.A, BramMystery diamonds - from alluvial deposits.GIA International Symposium 2011, Gems & Gemology, Summer abstract p. 110.GlobalAlluvials
DS1993-0157
1993
Bram, K.Bram, K., raxler, J.K.KTB Report on basic research and borehole geophysics in the KTB OberplfalzHB deep borehole... 4512.0 -6018.0 M.Ktb Report, No. 93-1, 93-2, table of contents available *requestGermanyBorehole, Super Deep drilling
DS1991-0223
1991
Braman, D.R.Carlisle, D.B., Braman, D.R.Nanometer size diamonds in the Cretaceous Tertiary boundary clay ofAlbertaNature, Vol. 352, No. 6337, August 22, pp. 708-709AlbertaMicro-diamonds, Meteorites
DS1991-0165
1991
Branagan, D.F.Branagan, D.F., Gibbons, G.S., Williams, K.L.The geological mapping of two southern continentsEdgeworth David Socity Department of Geology and Geophysics, University of, Australia, AntarcticaBook -ad, Geological mapping
DS2003-1117
2003
Branch, G.M.Pulfrich, A., Parkins, C.A., Branch, G.M.The effects of shore based diamond diving on intertidal and subtidal biologicalAquatic Conservation, Vol. 13, 3, pp. 233-56. Ingenta 1032281873NamibiaEnvironment
DS2003-1118
2003
Branch, G.M.Pulfrich, A., Parkins, C.A., Branch, G.M., Bustamante, R.H., Velasquez, C.R.The effects of sediment deposits from Namibian diamond mines on intertidal andAquatic Conservation, Vol. 13, 3, pp. 257-78. Ingenta 1032281872NamibiaEnvironment
DS200412-1599
2003
Branch, G.M.Pulfrich, A., Parkins, C.A., Branch, G.M.The effects of shore based diamond diving on intertidal and subtidal biological communities and rock lobsters in southern NamibiAquatic Conservation, Vol. 13, 3, pp. 233-56. Ingenta 1032281873Africa, NamibiaEnvironment
DS200412-1600
2003
Branch, G.M.Pulfrich, A., Parkins, C.A., Branch, G.M., Bustamante, R.H., Velasquez, C.R.The effects of sediment deposits from Namibian diamond mines on intertidal and subtidal reefs and rock lobster populations.Aquatic Conservation, Vol. 13, 3, pp. 257-78. Ingenta 1032281872Africa, NamibiaEnvironment
DS202205-0704
2022
Branch, G.M.Maritz, L., Pillay, D., Branch, G.M.The ecology of coastal wetland ponds created by diamond mining in southern Namibia. 1. Physical Conditions.African Journal of Marine Science, Vol. 44, 1, pp. 49-60.Africa, Namibiamining

Abstract: Coastal diamond mining in southern Namibia involves constructing seawalls to hold the sea at bay, and seaward accretion of the shoreline by up to 800 m opens what was previously the surf zone for excavation and extraction of bedrock alluvial diamonds. This has created large coastal wetland ponds of up to 380 000 m2 as the sea overtops the seawalls or seeps into the excavated areas. The ages of these ponds span 1-38 years. We investigated physical conditions in the ponds to determine whether they can function as saline wetlands equivalent to blind estuaries. Water temperatures were 6-10 °C higher than in the sea, as expected of shallow enclosed waterbodies. Dissolved oxygen was 82-137%, peaking at midday owing to photosynthesis, and the ponds were never hypoxic. Correlated with oxygen levels, pH values spanned 7.7-8.3, and always exceeded the pH of seawater. Chlorophyll a concentrations matched or exceeded the levels in seawater, reaching 76 µg l?1. The southern and central ponds had salinities close to those of seawater, but the salinity of northern ponds exceeded 80 after ?15 years, thus limiting their capacity to support wetland communities. Apart from this, these ponds are viable habitat that can support flora and fauna typical of saline wetlands, a habitat that is scarce along this arid coastline.
DS202205-0705
2022
Branch, G.M.Maritz, L., Pillay, D., Branch, G.M.The ecology of coastal wetland ponds created by diamond mining in southern Namibia. 2. Saltmarsh vegetation.African Journal of Marine Science, Vol. 44, 1, pp. 61-68.Africa, Namibiamining

Abstract: Coastal diamond mining in southern Namibia involves constructing seawalls to hold the sea at bay, and seaward accretion of the shoreline by up to 800 m opens what was previously the surf zone for excavation and extraction of bedrock alluvial diamonds. This has created large coastal wetland ponds of up to 380 000 m2 as the sea overtops the seawalls or seeps into the excavated areas. The ages of these ponds span 1-38 years. We investigated physical conditions in the ponds to determine whether they can function as saline wetlands equivalent to blind estuaries. Water temperatures were 6-10 °C higher than in the sea, as expected of shallow enclosed waterbodies. Dissolved oxygen was 82-137%, peaking at midday owing to photosynthesis, and the ponds were never hypoxic. Correlated with oxygen levels, pH values spanned 7.7-8.3, and always exceeded the pH of seawater. Chlorophyll a concentrations matched or exceeded the levels in seawater, reaching 76 µg l?1. The southern and central ponds had salinities close to those of seawater, but the salinity of northern ponds exceeded 80 after ?15 years, thus limiting their capacity to support wetland communities. Apart from this, these ponds are viable habitat that can support flora and fauna typical of saline wetlands, a habitat that is scarce along this arid coastline.
DS1960-0023
1960
Branch, H.Branch, H.A 6.45 Carat Diamond from ArkansawGems And Gemology, Vol. 23, SPRING, PP. 7-9.United States, Gulf Coast, Arkansas, PennsylvaniaDiamonds Notable
DS202104-0566
2021
Branchetti, M.Branchetti, M., Zepper, J.C.O., Peters, S.T.J., Koornneef, J.M., Davies, G.Multi-stage formation and destruction in Kimberley harzburgitic xenoliths, South Africa.Lithos, in press available, 57p. PdfAfrica, South Africadeposit - Kimberley

Abstract: Thirty-nine garnet harzburgites from Kimberley in the Kaapvaal Craton (South Africa) were studied to constrain the origin, age and evolution of sub-cratonic lithospheric mantle (SCLM). In order to avoid chemical overprinting by recent metasomatism, only garnet harzburgites that appeared clinopyroxene-free to the naked eye were sampled. The majority of garnets were, however, in equilibrium with clinopyroxene (24 of 39). Whole rock and mineral major-trace element geochemistry and garnet Sr-Nd-Hf isotope data are presented. Equilibration pressures range from 3.8-6.1?GPa, indicating the harzburgites were derived from a large portion of the SCLM (~115-185?km). High olivine Mg# (~93.4, n?=?39) and low whole rock heavy rare earth elements (HREE) contents are consistent with large degrees of partial melting (>45%) and garnet exhaustion leaving a dunitic residue with olivine ?90%, orthopyroxene ?10% and HREE <0.01 times chondrite. Mineral modes, whole rock Al2O3 (0.5-3.2?wt%) and SiO2 (43.1-49.1?wt%), however, indicate heterogeneous re-introduction of garnet (?13%) and orthopyroxene (?50%). Harzburgites with high garnet and relatively low orthopyroxene modes (mostly ~7-13% and?~?9-30%; n?=?6) are characterised by mildly sinusoidal garnet REE patterns (Tbsingle bondDy minimum and high HREE) and Archaean depleted Hf TDM ages (2.7-3.3?Ga; ?Hfe: +190 to +709). In contrast, harzburgites with high orthopyroxene and relatively low garnet and modes (~1.5-7.5% and?~?25-50%; n?=?19) are characterised by highly sinuous REE patterns (Hosingle bondYb minimum and low HREE) and Proterozoic enriched Hf TDM ages (0.7-1.6?Ga; ?Hfe: ?16 to +6). It is inferred that Archaean G10 garnet re-introduction caused a significant increase in HREE, making melt depletion models based on HREE inaccurate. Orthopyroxene addition, a few hundred million years later, most likely at ~2.7?Ga and associated with Ventersdorp magmatic activity, caused partial consumption of garnet and olivine, and changed garnet compositions leading to: 1) Cr/Al ratio increase; 2) HREE decrease; 3) more sinusoidal REE patterns; and 4) un-radiogenic 176Hf/177Hf. Garnets define a Lusingle bondHf isochron age of 2702?±?64?Ma (?Hfi?=?+44, n?=?31), which is interpreted as a consequence of partial isotopic equilibrium within the SCLM and mixing of the garnet- and orthopyroxene-rich metasomatic components. The low LILE contents and absence of Nbsingle bondTa anomalies are consistent with modal metasomatism caused by intra-plate magmatism. In addition, the REE signatures of metasomatic agents in equilibrium with the garnets suggest that carbonatitic melts and SiO2-rich hydrous melts were responsible for re-introduction of garnet and orthopyroxene, respectively. Srsingle bondNd isotope systematics were disrupted associated with kimberlite magmatism (Nd isochron: 217?±?58?Ma, ?Ndi?=?+4; n?=?34), consistent with recent G10 garnet transformation into G9 garnets (Ca?+?Fe-enriched). This event may have caused garnet addition (up to 1%), suggesting that garnet was formed or destroyed in at least 4 different events: i) initial extensive polybaric melting, ii) asthenospheric melts re-introducing the bulk of the garnet, iii) orthopyroxene addition and garnet loss, all in the Archaean, and iv) minor garnet addition possibly related to recent kimberlite magmatism prior to eruption.
DS1993-0158
1993
Branchu, P.Branchu, P., Faure, O.K., et al.Africa as source and sink for atmospheric carbon dioxideSpecial issue, pp. 41-50AfricaMantle, Degassing
DS1986-0102
1986
Branco, R.Branco, R., Mariano, G. Castelo.Geologic aspects of Brazilian kimberlites.(in Portugese)Rem. Revista Escola de Minas, (in Portugese)., Vol. 39, No. 4, pp. 28-36BrazilBlank
DS1860-0837
1894
Branco, W.Branco, W.Schwabens 125 Vulkan-embryonen und Deren Tufferfuellte Ausbruchsrohren, das Grosste Gebiet Ehemaliger Maare Auf der Erde.Stuttgart: Jahr. Ver. Natk., Vol. XV, 816P.Europe, GermanyGeomorphology, Diatreme
DS201412-0067
2014
Brand, C.J.Brand, N.W., Brand, C.J.Performance comparison of portable XRF instruments.Geochemistry: Exploration, Environment, Analysis, Vol. 14, 2, pp. 125-138.TechnologyXRF
DS201609-1748
2016
Brand, N.B.Tappe, S., Brand, N.B., Stracke, A., van Acken, D., Liu, C-Z., Strauss, H., Wu, F-Y., Luguet, A., Mitchell, R.H.Plates or plumes in the origin of kimberlites: U/PB perovskite and Sr-Nd-Hf-Os-C-O isotope constraints from the Superior craton ( Canada).Chemical Geology, in press available 85p.Canada, QuebecDeposit - Renard, Wemindji

Abstract: Neoproterozoic kimberlite, ultramafic lamprophyre, and carbonatite magmatic activity was widespread across the Canadian-Greenland Shield. Models to explain the preponderance of this deeply-derived CO2-rich magmatism between 680-540 Ma range from impingement of multiple mantle plumes to rifting activity linked to the breakout of the Laurentian plate from the Rodinia supercontinent configuration. We add to the debate about the origin of kimberlite magmas and evaluate possible mantle sources of the 655 Ma ‘diamond-rich’ Renard (new SIMS U/Pb perovskite ages) and 629 Ma ‘barren’ Wemindji kimberlites on the eastern Superior craton in Quebec, Canada. Our Sr-Nd-Hf and carbon isotope data (87Sr/86Sri = 0.70241-0.70442; ?Ndi = + 0.2 to + 4.8; ?Hfi = + 0.3 to + 6.5; ?13C = ? 5.6 to ? 3.9‰) suggest a common and moderately depleted convecting upper mantle source region for both the Renard and Wemindji kimberlites, which occur 400-km apart in the interior of the Superior craton. In contrast, the low Os isotope ratios (187Os/188Osi = 0.11078-0.12620; ?Osi = ? 13.7 to ? 1.6) and unfractionated chondritic relative HSE abundances (Os, Ir, Ru, Pt, Pd, Re) indicate significant involvement of ancient refractory cratonic mantle material in kimberlite magma formation. Our model calculations suggest that for both the diamond-rich Renard and the barren Wemindji kimberlite magmas up to 30% of the Os was derived from refractory cratonic peridotites. This material might have been assimilated by originally more CO2-rich carbonated silicate melts derived from the asthenosphere. We also show that the geochemical and Sr-Nd-Hf-Os isotopic compositions of the Renard and Wemindji kimberlites do not require significant input from melts derived from olivine-poor cratonic mantle lithologies such as MARID-type veins and pyroxenites/eclogites. This contrasts with the petrogenesis of deeply-derived volatile-rich potassic magmas found along the peripheries of cratons (e.g., ultramafic lamprophyres, kamafugites, and olivine lamproites), a setting where abundant non-peridotitic components have been added to the lithospheric mantle over the course of continent evolution. Provided that CO2-rich melts, such as proto-kimberlites, occur near the solidus of volatile-fluxed peridotites, no excess mantle heat is required in their formation. This important but often overlooked constraint, together with the observation that there exist no spatial or temporal relationships between the Superior craton kimberlites and Large Igneous Provinces during the Late Neoproterozoic, suggests that kimberlite magmatic activity was tectonically controlled. In our preferred model, ubiquitous CO2-rich proto-kimberlite melts form during volatile-controlled redox melting processes at ambient mantle temperatures in a thermal boundary layer directly beneath thick cratonic lithosphere. The success rate of ‘evolving’ hybrid kimberlite magmas reaching Earth’s surface increases when tensile stresses propagate into the > 200 km thick keels of continental lithosphere. These conditions are frequently met during fast and changing plate motions associated with the assembly and breakup of supercontinents.
DS201612-2341
2016
Brand, N.B.Tappe, S., Brand, N.B., Strackc, A., van Acken, D., Lie, C-Z., Strausf, H., Wu, F-Y., Luguet, A., Mitchell, R.H.Plates or plumes in the origin of kimberlites: U/PB perovskite and Sr-Nd-Hf-Os-C-O isotope constraints from the Superior craton ( Canada).Chemical Geology, on line August 27p.Canada, QuebecDeposit - Renard, Wemindji

Abstract: Neoproterozoic kimberlite, ultramafic lamprophyre, and carbonatite magmatic activity was widespread across the Canadian-Greenland Shield. Models to explain the preponderance of this deeply-derived CO2-rich magmatism between 680-540 Ma range from impingement of multiple mantle plumes to rifting activity linked to the breakout of the Laurentian plate from the Rodinia supercontinent configuration. We add to the debate about the origin of kimberlite magmas and evaluate possible mantle sources of the 655 Ma ‘diamond-rich’ Renard (new SIMS U/Pb perovskite ages) and 629 Ma ‘barren’ Wemindji kimberlites on the eastern Superior craton in Quebec, Canada. Our Sr-Nd-Hf and carbon isotope data (87Sr/86Sri = 0.70241-0.70442; ?Ndi = + 0.2 to + 4.8; ?Hfi = + 0.3 to + 6.5; ?13C = ? 5.6 to ? 3.9‰) suggest a common and moderately depleted convecting upper mantle source region for both the Renard and Wemindji kimberlites, which occur 400 km apart in the interior of the Superior craton. In contrast, the low Os isotope ratios (187Os/188Osi = 0.11078-0.12620; ?Osi = ? 13.7 to ? 1.6) and unfractionated chondritic relative HSE abundances (Os, Ir, Ru, Pt, Pd, Re) indicate significant involvement of ancient refractory cratonic mantle material in kimberlite magma formation. Our model calculations suggest that for both the diamond-rich Renard and the barren Wemindji kimberlite magmas up to 30% of the Os was derived from refractory cratonic peridotites. This material might have been assimilated by originally more CO2-rich carbonated silicate melts derived from the asthenosphere. We also show that the geochemical and Sr-Nd-Hf-Os isotopic compositions of the Renard and Wemindji kimberlites do not require significant input from melts derived from olivine-poor cratonic mantle lithologies such as MARID-type veins and pyroxenites/eclogites. This contrasts with the petrogenesis of deeply-derived volatile-rich potassic magmas found along the peripheries of cratons (e.g., ultramafic lamprophyres, kamafugites, and olivine lamproites), a setting where abundant non-peridotitic components have been added to the lithospheric mantle over the course of continent evolution. Provided that CO2-rich melts, such as proto-kimberlites, occur near the solidus of volatile-fluxed peridotites, no excess mantle heat is required in their formation. This important but often overlooked constraint, together with the observation that there exist no spatial or temporal relationships between the Superior craton kimberlites and Large Igneous Provinces during the Late Neoproterozoic, suggests that kimberlite magmatic activity was tectonically controlled. In our preferred model, ubiquitous CO2-rich proto-kimberlite melts form during volatile-controlled redox melting processes at ambient mantle temperatures in a thermal boundary layer directly beneath thick cratonic lithosphere. The success rate of ‘evolving’ hybrid kimberlite magmas reaching Earth’s surface increases when tensile stresses propagate into the > 200 km thick keels of continental lithosphere. These conditions are frequently met during fast and changing plate motions associated with the assembly and breakup of supercontinents.
DS201707-1375
2017
Brand, N.B.Tappe, S., Brand, N.B., Stracke, A., van Acken, D., Liu, C-Z., Strauss, H., Wu, F-Y., Luguet, A., Mitchell, R.H.Plates or plumes in the origin of kimberlites: U/pb perovskite and Sr-Nd-Hf-Os-C-O isotope contraints from the Superior craton ( Canada).Chemical Geology, Vol. 455, pp. 57-83.Canadadeposit - Renard, Wemndiji

Abstract: Neoproterozoic kimberlite, ultramafic lamprophyre, and carbonatite magmatic activity was widespread across the Canadian-Greenland Shield. Models to explain the preponderance of this deeply-derived CO2-rich magmatism between 680–540 Ma range from impingement of multiple mantle plumes to rifting activity linked to the breakout of the Laurentian plate from the Rodinia supercontinent configuration. We add to the debate about the origin of kimberlite magmas and evaluate possible mantle sources of the 655 Ma ‘diamond-rich’ Renard (new SIMS U/Pb perovskite ages) and 629 Ma ‘barren’ Wemindji kimberlites on the eastern Superior craton in Quebec, Canada. Our Sr-Nd-Hf and carbon isotope data (87Sr/86Sri = 0.70241–0.70442; ?Ndi = + 0.2 to + 4.8; ?Hfi = + 0.3 to + 6.5; ?13C = ? 5.6 to ? 3.9‰) suggest a common and moderately depleted convecting upper mantle source region for both the Renard and Wemindji kimberlites, which occur 400 km apart in the interior of the Superior craton. In contrast, the low Os isotope ratios (187Os/188Osi = 0.11078–0.12620; ?Osi = ? 13.7 to ? 1.6) and unfractionated chondritic relative HSE abundances (Os, Ir, Ru, Pt, Pd, Re) indicate significant involvement of ancient refractory cratonic mantle material in kimberlite magma formation. Our model calculations suggest that for both the diamond-rich Renard and the barren Wemindji kimberlite magmas up to 30% of the Os was derived from refractory cratonic peridotites. This material might have been assimilated by originally more CO2-rich carbonated silicate melts derived from the asthenosphere. We also show that the geochemical and Sr-Nd-Hf-Os isotopic compositions of the Renard and Wemindji kimberlites do not require significant input from melts derived from olivine-poor cratonic mantle lithologies such as MARID-type veins and pyroxenites/eclogites. This contrasts with the petrogenesis of deeply-derived volatile-rich potassic magmas found along the peripheries of cratons (e.g., ultramafic lamprophyres, kamafugites, and olivine lamproites), a setting where abundant non-peridotitic components have been added to the lithospheric mantle over the course of continent evolution. Provided that CO2-rich melts, such as proto-kimberlites, occur near the solidus of volatile-fluxed peridotites, no excess mantle heat is required in their formation. This important but often overlooked constraint, together with the observation that there exist no spatial or temporal relationships between the Superior craton kimberlites and Large Igneous Provinces during the Late Neoproterozoic, suggests that kimberlite magmatic activity was tectonically controlled. In our preferred model, ubiquitous CO2-rich proto-kimberlite melts form during volatile-controlled redox melting processes at ambient mantle temperatures in a thermal boundary layer directly beneath thick cratonic lithosphere. The success rate of ‘evolving’ hybrid kimberlite magmas reaching Earth’s surface increases when tensile stresses propagate into the > 200 km thick keels of continental lithosphere. These conditions are frequently met during fast and changing plate motions associated with the assembly and breakup of supercontinents.
DS201412-0067
2014
Brand, N.W.Brand, N.W., Brand, C.J.Performance comparison of portable XRF instruments.Geochemistry: Exploration, Environment, Analysis, Vol. 14, 2, pp. 125-138.TechnologyXRF
DS1999-0091
1999
Brand, U.Brand, U., Campbell, I.T.FugacityEncyclopedia Geochemistry, Marshall and Fairbridge, p. 256.GlobalFugacity - definition
DS1986-0103
1986
Brandeis, G.Brandeis, G., Jaupart, C.On the interaction between convection and crystallization in cooling magma chambersEarth and Planetary Science Letters, Vol. 77, No. 3-4, April pp. 345-361GlobalMantle
DS1993-0159
1993
Brandeis, G.Brandeis, G.Constraints on the formation of cyclic units in ultramafic zones of large basaltic chambersContributions to Mineralogy and Petrology, Vol. 112, pp. 312-328GlobalMagma chambers, Petrology, theory
DS200512-0494
2005
Brandeis, G.Jurine, D., Jaupart, C., Brandeis, G., Tackley, P.J.Penetration of mantle plumes through depleted lithosphere.Journal of Geophysical Research, Vol. 110, B10, B 10104 10.1029/2005 JB003751MantleTectonics
DS200712-0049
2007
Brandenburg, J.P.Ballentine, C.J., Brandenburg, J.P., Van Keken, P.E., Holland, G.Seawater recycling into the deep mantle - and the source of 3He.Plates, Plumes, and Paradigms, 1p. abstract p. A56.MantleNoble gases
DS200712-0099
2007
Brandenburg, J.P.Brandenburg, J.P., Van Keken, P.E.Deep storage of oceanic crust in a vigourously convecting mantle.Journal of Geophysical Research, Vol. 112, B 6, B06403MantleConvection
DS200712-0100
2007
Brandenburg, J.P.Brandenburg, J.P., Van Keken, P.E.Deep storage of oceanic crust in a vigorously convecting mantle.Journal of Geophysical Research, Vol. 112, B6 B06403MantleConvection
DS200712-0422
2007
Brandenburg, J.P.Hauri, E.H., Brandenburg, J.P., Van Keken, P.E.What comes around goes around: mantle convection and the meaning of mantle isochrons.Plates, Plumes, and Paradigms, 1p. abstract p. A385.MantleGeochronology
DS1995-0200
1995
Brandl, G.Brandl, G.Reactivation of certain faults in the Limpopo Belt during the QuaternaryCentennial Geocongress (1995) Extended abstracts, Vol. 1, p. 442-444. abstractZimbabwe, BotswanaCraton, Tectonics -structure
DS1995-0201
1995
Brandl, G.Brandl, G., McCarthy, T.S., Andreoli, M.A.G., AndersenTectonic and lineament investigations of the Vaalputs area, Namaqualand, South Africa: implications rifting..Centennial Geocongress (1995) Extended abstracts, Vol. 1, p. 445-448. abstractSouth AfricaTectonics
DS200812-0960
2008
Brandl, G.Rigby, M., Mouri, H., Brandl, G.A review of the pressure temperature time evolution of the Limpopo Belt: contraints for a tectonic model.Journal of African Earth Sciences, Vol. 50, 2-4, pp. 120-132.Africa, South AfricaTectonics
DS201112-1122
2011
Brandl, G.Wu, F-Y., Yang, Y-H.,Li, Q-L., Mitchell, R.H., Dawson, J.B., Brandl, G., Yuhara, M.In situ determination of U-Pb ages and Sr-Nd-Hf isotopic constraints on the petrogenesis of the Phalaborwa carbonatites complex, South Africa.Lithos, Vol. 127, 1-2, pp. 309-322.Africa, South AfricaCarbonatite, geochronology, Palaborwa
DS202003-0373
2020
Brandl, G.Yin, A., Brandl, G., Kroner, A.Plate tectonics processes at ca 2.0 Ga: evidence from >600 km of plate convergence. Limpopo beltGeology, Vol. 48, pp. 103-107.Africa, South Africatectonics

Abstract: We addressed when plate-tectonic processes first started on Earth by examining the ca. 2.0 Ga Limpopo orogenic belt in southern Africa. We show through palinspastic reconstruction that the Limpopo orogen originated from >600 km of west-directed thrusting, and the thrust sheet was subsequently folded by north-south compression. The common 2.7-2.6 Ga felsic plutons in the Limpopo thrust sheet and the absence of an arc immediately predating the 2.0 Ga Limpopo thrusting require the Limpopo belt to be an intracontinental structure. The similar duration (?40 m.y.), slip magnitude (>600 km), slip rate (>15 mm/yr), tectonic setting (intracontinental), and widespread anatexis to those of the Himalayan orogen lead us to propose the Limpopo belt to have developed by continent-continent collision. Specifically, the combined Zimbabwe-Kaapvaal craton (ZKC, named in this study) in the west (present coordinates) was subducting eastward below an outboard craton (OC), which carried an arc equivalent to the Gangdese batholith in southern Tibet prior to the India-Asia collision. The ZKC-OC collision at ca. 2.0 Ga triggered a westward jump in the plate convergence boundary, from the initial suture zone to the Limpopo thrust within the ZKC. Subsequent thrusting accommodated >600 km of plate convergence, possibly driven by ridge push from the west side of the ZKC. As intracontinental plate convergence is a key modern plate-tectonic process, the development of the Limpopo belt implies that the operation of plate tectonics, at least at a local scale, was ongoing by ca. 2.0 Ga on Earth.
DS200612-0163
2006
Brandon, A.Brandon, A.Mantle-core interactions.Goldschmidt Conference 16th. Annual, S4-04 theme abstract 1/8p. goldschmidt2006.orgMantleMineral chemistry
DS201607-1333
2016
Brandon, A.Brandon, A.Mapping off-craton subcontinental mantle lithosphere growth and destruction in the southwest United States using Os isotopes.IGC 35th., Session A Dynamic Earth 1p. AbstractUnited StatesGeochronology
DS201610-1848
2016
Brandon, A.Brandon, A.Tectonics: changing of the plates.Nature Geoscience, Vol. 9, pp. 731-732.MantleMelting

Abstract: The composition of Earth's crust depends on the style of plate tectonics and of the melting regimes in the mantle. Analyses of the oldest identified rocks suggest that these styles and the resulting crust have changed over Earth's history.
DS201910-2295
2019
Brandon, 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.
DS1996-0166
1996
Brandon, A.D.Brandon, A.D., Draper, D.S.Contraints on the origin of the oxidation state of mantle overlying subduction zones: an example from Simcoe Washington, USAGeochimica et Cosmochimica Acta, Vol. 60, No. 10, pp. 1739-49.GlobalTectonics - subduction
DS1998-0158
1998
Brandon, A.D.Brandon, A.D., Walker, Morgan, Snow190 Pc 186 Os isotopic systematics of the upper mantle and some plumesMineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 227-8.MantleConvection, Chromitites, peridotites
DS2003-0783
2003
Brandon, A.D.Lee, C.T., Brandon, A.D., Norman, M.Vanadium in peridotites as a proxy for paleo f02 during partial meltingGeochimica et Cosmochimica Acta, Vol. 67, 16, pp. 3045-64.GlobalPeridotites
DS200412-1100
2003
Brandon, A.D.Lee, C.T., Brandon, A.D., Norman, M.Vanadium in peridotites as a proxy for paleo f02 during partial melting.Geochimica et Cosmochimica Acta, Vol. 67, 16, pp. 3045-64.TechnologyPeridotite
DS200412-1598
2004
Brandon, A.D.Puchtel, I.S., Brandon, A.D., Humayun, M.Precise Pt Re O isotope systematics of the mantle from 2.7 Ga komatiites.Earth and Planetary Science Letters, Vol. 224, 1-2, pp. 157-174.MantleGeochronology
DS200512-0109
2005
Brandon, A.D.Brandon, A.D., Walker, R.J.The debate over the core-mantle interaction.Earth and Planetary Science Letters, Vol. 232, 3-4, April 15, pp. 211-225.MantleIsotope systematics, boundary, geochronology
DS200512-0881
2005
Brandon, A.D.Puchtel, I.S., Brandon, A.D., Humayun, M., Walker, R.J.Evidence for the early differentiation of the core from Pt-Re-Os isotope systematics of 2.8 Ga komatiites.Earth and Planetary Science Letters, Vol. 237, 1-2, Aug, 30, pp. 118-134.Europe, Baltic ShieldGeochronology, core-mantle interaction
DS200612-0164
2006
Brandon, A.D.Brandon, A.D.Mantle core interactions overview: the Os isotope perspective.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.MantleGeochronology
DS200612-0165
2006
Brandon, A.D.Brandon, A.D., Walker, R.J., Puchtel, I.S.Platinum osmium isotope evolution of the Earth's mantle: constraints from chondrites and Os rich alloys.Geochimica et Cosmochimica Acta, In pressMantleKomatiitie, chondrites, PGE, geochronology
DS200612-1502
2006
Brandon, A.D.Walker, R.J., Ireland, T., Brandon, A.D.The search for evidence of chemical interactions between the core and mantle.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 2, abstract only.MantleGeochemistry
DS200712-0101
2007
Brandon, A.D.Brandon, A.D., Graham, D.W., Waight, T., Gautason, B.188 Os amd 187 Os enrichments and high 3He 4He sources in the Earth's mantle evidence from Iclandic picrites.Geochimica et Cosmochimica Acta, Vol. 71, 18, Sept. pp. 4570-91.Europe, IcelandPicrite
DS200712-0102
2007
Brandon, A.D.Brandon, A.D., Graham, D.W., Waight, T., Gautason, B.Os He isotope systematics of Iceland picrites: evidence for a deep origin of the Iceland plume.Plates, Plumes, and Paradigms, 1p. abstract p. A119.Europe, IcelandPicrite
DS200712-1127
2007
Brandon, A.D.Waight, T., Brandon, A.D., Graham, D.W., Gautason, B.Isotopic constraints on picritic magmatism, Iceland.Plates, Plumes, and Paradigms, 1p. abstract p. A1078.Europe, IcelandPicrite
DS200812-0104
2007
Brandon, A.D.Bennett, V.C., Brandon, A.D., Nutman, A.P.Coupled 142 Nd- 143 Nd isotopic evidence for Hadean mantle dynamics.Science, Vol. 318, no. 5858 Dec. 21, pp. 1907-1909.MantleGeochronology
DS201012-0522
2009
Brandon, A.D.Murphy, D.T., Brandon, A.D., Debaille, V., Burgess, R., Ballentine, C.In search of a hidden long term isolated sub-chondritic 142 Nd 144Nd reservoir in the deep mantle: implications for the Nd isotope systematics of the Earth.Geochimica et Cosmochimica Acta, Vol. 74, 2, pp. 738-750.MantleGeochronology
DS201312-0202
2013
Brandon, A.D.DeBaille, V., O'Neill, C., Brandon, A.D., Haenecour, P., Yin, Q-Z., Mattielli, N., Trieman, A.H.Stagnant lid tectonics in early Earth revealed bu 142 Nd variations in late Archean rocks.Earth and Planetary Science Letters, Vol. 373, pp. 83-92.MantleConvection
DS201412-0015
2014
Brandon, A.D.Armytage, R.M.G., Brandon, A.D., Peslier, A.H., Lapen, T.J.Osmium isotope evidence for Early to Middle Proterozoic mantle lithosphere stabilization and concommitant production of juvenile crust in Dish Hill, CA peridotite xenoliths.Geochimica et Cosmochimica Acta, Vol. 137, pp. 113-133.United States, CaliforniaSCLM, subduction
DS201412-0208
2014
Brandon, A.D.Doucet, L.S., Peslier, A.H., Ionov, D.A., Brandon, A.D., Golovin, A.V., Goncharov, A.G., Ashchepkov, I.V.High water contents in the Siberian cratonic mantle linked to metasomatism: an FTIR study of Udachnaya peridotite xenoliths.Geochimica et Cosmochimica Acta, in press availableRussia, SiberiaDeposit - Udachnaya
DS202011-2047
2020
Brandon, A.D.Kilgore, M.L., Peslier, A.H., Brandon, A.D., Schaffer, L.A., Morris, R.V., Graff, T.G., Agresti, D.G., O'Reilly, S.Y., Griffin, W.L., Pearson, D.G., Barry, K.G., Shaulis, J.Metasomatic control of hydrogen contents in the layered cratonic mantle lithosphere sampled by Lac de Gras xenoliths in the central Slave Craton, Canada.Geochimica et Cosmochimica Acta, Vol. 286, pp. 29-83. pdfCanada, Northwest Territoriesxenoliths

Abstract: Whether hydrogen incorporated in nominally anhydrous mantle minerals plays a role in the strength and longevity of the thick cratonic lithosphere is a matter of debate. In particular, the percolation of hydrogen-bearing melts and fluids could potentially add hydrogen to the mantle lithosphere, weaken its olivines (the dominant mineral in mantle peridotite), and cause delamination of the lithosphere's base. The influence of metasomatism on hydrogen contents of cratonic mantle minerals can be tested in mantle xenoliths from the Slave Craton (Canada) because they show extensive evidence for metasomatism of a layered cratonic mantle. Minerals from mantle xenoliths from the Diavik mine in the Lac de Gras kimberlite area located at the center of the Archean Slave craton were analyzed by FTIR for hydrogen contents. The 18 peridotites, two pyroxenites, one websterite and one wehrlite span an equilibration pressure range from 3.1 to 6.6 GPa and include samples from the shallow (?145?km), oxidized ultra-depleted layer; the deeper (?145-180?km), reduced less depleted layer; and an ultra-deep (?180?km) layer near the base of the lithosphere. Olivine, orthopyroxene, clinopyroxene and garnet from peridotites contain 30-145, 110-225, 105-285, 2-105?ppm H2O, respectively. Within each deep and ultra-deep layer, correlations of hydrogen contents in minerals and tracers of metasomatism (for example light over heavy rare-earth-element ratio (LREE/HREE), high-field-strength-element (HFSE) content with equilibration pressure) can be explained by a chromatographic process occurring during the percolation of kimberlite-like melts through garnet peridotite. The hydrogen content of peridotite minerals is controlled by the compositions of the evolving melt and of the minerals and by mineral/melt partition coefficients. At the beginning of the process, clinopyroxene scavenges most of the hydrogen and garnet most of the HFSE. As the melt evolves and becomes enriched in hydrogen and LREE, olivine and garnet start to incorporate hydrogen and pyroxenes become enriched in LREE. The hydrogen content of peridotite increases with decreasing depth, overall (e.g., from 75 to 138?ppm H2O in the deep peridotites). Effective viscosity calculated using olivine hydrogen content for the deepest xenoliths near the lithosphere-asthenosphere boundary overlaps with estimates of asthenospheric viscosities. These xenoliths cannot be representative of the overall cratonic root because the lack of viscosity contrast would have caused basal erosion of lithosphere. Instead, metasomatism must be confined in narrow zones channeling kimberlite melts through the lithosphere and from where xenoliths are preferentially sampled. Such localized metasomatism by hydrogen-bearing melts therefore does not necessarily result in delamination of the cratonic root.
DS1860-0221
1874
Brandon, J.Brandon, J.Taillerie Francaise de DiamantsParis:, GlobalDiamond Jewellers
DS202008-1422
2020
Brandon, L.A.McKensie, L., Kilgore, A.H., Peslier, A.D., Brandon, L.A., Schaffer, R.V., Graff, T.G., Agresti, D.G., O'Reilly, S.Y., Griffin, W.L., Pearson, D.G., Hangi, K., Shaulis, B.J.Metasomatic control of hydrogen contents in the layered cratonic mantle lithosphere sampled by Lac de Gras xenoliths in the central Slave craton, Canada.Geochimica et Cosmochimica Acta, in press available, doi.org/101016 /j.gca.2020.07.013 45p. PdfCanada, Northwest Territoriesdeposit - Lac de Gras

Abstract: Whether hydrogen incorporated in nominally anhydrous mantle minerals plays a role in the strength and longevity of the thick cratonic lithosphere is a matter of debate. In particular, the percolation of hydrogen-bearing melts and fluids could potentially add hydrogen to the mantle lithosphere, weaken its olivines (the dominant mineral in mantle peridotite), and cause delamination of the lithosphere's base. The influence of metasomatism on hydrogen contents of cratonic mantle minerals can be tested in mantle xenoliths from the Slave Craton (Canada) because they show extensive evidence for metasomatism of a layered cratonic mantle. Minerals from mantle xenoliths from the Diavik mine in the Lac de Gras kimberlite area located at the center of the Archean Slave craton were analyzed by FTIR for hydrogen contents. The 18 peridotites, two pyroxenites, one websterite and one wehrlite span an equilibration pressure range from 3.1 to 6.6 GPa and include samples from the shallow (? 145 km), oxidized ultra-depleted layer; the deeper (?145-180 km), reduced less depleted layer; and an ultra-deep (? 180 km) layer near the base of the lithosphere. Olivine, orthopyroxene, clinopyroxene and garnet from peridotites contain 30 - 145, 110 - 225, 105 - 285, 2 - 105 ppm H2O, respectively. Within each deep and ultra-deep layer, correlations of hydrogen contents in minerals and tracers of metasomatism (for example light over heavy rare-earth-element ratio (LREE/HREE), high-field-strength-element (HFSE) content with equilibration pressure) can be explained by a chromatographic process occurring during the percolation of kimberlite-like melts through garnet peridotite. The hydrogen content of peridotite minerals is controlled by the compositions of the evolving melt and of the minerals and by mineral/melt partition coefficients. At the beginning of the process, clinopyroxene scavenges most of the hydrogen and garnet most of the HFSE. As the melt evolves and becomes enriched in hydrogen and LREE, olivine and garnet start to incorporate hydrogen and pyroxenes become enriched in LREE. The hydrogen content of peridotite increases with decreasing depth, overall (e.g., from 75 to 138 ppm H2O in the deep peridotites). Effective viscosity calculated using olivine hydrogen content for the deepest xenoliths near the lithosphere-asthenosphere boundary overlaps with estimates of asthenospheric viscosities. These xenoliths cannot be representative of the overall cratonic root because the lack of viscosity contrast would have caused basal erosion of lithosphere. Instead, metasomatism must be confined in narrow zones channeling kimberlite melts through the lithosphere and from where xenoliths are preferentially sampled. Such localized metasomatism by hydrogen-bearing melts therefore does not necessarily result in delamination of the cratonic root.
DS2002-0937
2002
Brandon, M.Levin, V., Park, J., Brandon, M., Lees, J., Peyton, V., Gordeev, E., Ozerv, A.Crust and upper mantle of Kamchatka from teleseismic receiver functionsTectonophysics, Vol. 358, 1-4, pp. 233-265.MantleGeophysics - seismics
DS200512-0497
2005
Brandon, M.Katayama, I., Karato, S-I., Brandon, M.Evidence of high water content in the deep upper mantle inferred from deformation microstructures.Geology, Vol. 33, 7, July pp. 613-616.Europe, NorwayMajorite garnet
DS1990-1273
1990
Brandon, M.T.Rubin, C.M., Saleeby, J.B., Cowan, D.S., Brandon, M.T., McGroderRegionally extensive mid-Cretaceous west-vergent thrust system in the northwestern Cordillera: implications for continent-margin tectonisM.Geology, Vol. 18, No. 3, March pp. 276-280British ColumbiaTectonics, Thrust system
DS1993-0160
1993
Brandon, M.T.Brandon, M.T., Paterson, S.R.Applications of strain: from microstructures to orogenic beltsGsa Today, Vol. 3, No. 7, July pp. 174-175GlobalOrogeny, Tectonics
DS1994-0351
1994
Brandon, M.T.Cowan, D.S., Brandon, M.T.A symmetry based method for kinetc analysis of large slip brittle faultzonesAmerican Journal of Science, Vol. March pp. 257-306GlobalGeometry, Structure -fault systems
DS1994-1462
1994
Brandon, M.T.Ring, U., Brandon, M.T.Kinematic dat a for the Coast Range fault and implications for exhumation Of the Franciscan complexGeology, Vol. 22, No. 8, August pp. 735-738California, CordilleraTectonics, Subduction -Franciscan complex
DS1995-0202
1995
Brandon, M.T.Brandon, M.T., Ring, U.Exhumation processes: normal faulting, ductile flow, and erosionGsa Today, Vol. 5, No. 12, Dec. pp. 242-243GlobalStructure, Faults
DS1997-0123
1997
Brandon, M.T.Brandon, M.T., Ring, U.Exhumation processes: normal faulting, ductile flow and erosionGsa Today, Vol. 7, No. 5, May pp. 17-20GlobalPenrose Conference report, Exhumation processes
DS2002-0120
2002
Brandon, M.T.Batt, G.E., Brandon, M.T.Lateral thinking: 2 D interpretation of thermochronology in convergent orogenic settingsTectonophysics, Vol. 349, No. 1-4, pp. 185-201.GlobalGeochronology, Tectonics
DS2002-1712
2002
Brandon, M.T.Willett, S.D., Brandon, M.T.On steady states in mountain beltsGeology, Vol. 30, No. 2, Feb. pp.175-8.GlobalOrogeny - model, Subduction driven
DS2003-1155
2003
Brandon, M.T.Reiners, P.W., Zhou, Z., Ehlers, T.A., Xu, C., Brandon, M.T., Donelick, R.A.Post orogenic evolution of the Dabie Shan, eastern Chin a ( U Th) He and fission trackAmerican Journal of Science, Vol. 303, 6, pp. 489-518.ChinaGeothermometry, UHP
DS200412-1652
2003
Brandon, M.T.Reiners, P.W., Zhou, Z., Ehlers, T.A., Xu, C., Brandon, M.T., Donelick, R.A., Nicolescu, S.Post orogenic evolution of the Dabie Shan, eastern Chin a ( U Th) He and fission track thermochronology.American Journal of Science, Vol. 303, 6, pp. 489-518.ChinaGeothermometry UHP
DS201212-0536
2012
Brandon, M.T.Paczkowski, K., Bercovici, D., Landuyt, W., Brandon, M.T.Drip instabilities of continental lithosphere: acceleration and entrainment by damage.Geophysical Journal International, in press availableMantleRheology
DS2002-1252
2002
BrandstatterPetersen, O.V., Giester, G., Brandstatter, NiedermayrNabesite, new mineral species from Ilmaussaq alkaline complex, south GreenlandCanadian Mineralogist, Vol.40,1,Feb.pp. 173-81.GreenlandAlkaline rocks
DS201212-0086
2011
Brandt, M.B.Brandt, M.B., Grand, S.P., Nyblade, A.A., Dirks, P.H.G.Upper mantle seismic structure beneath southern Africa: constraints on the bouyancy supporting the African Superswell.Pure and Applied Geophysics, Vol. 169, 4, pp. 595-614.Africa, South AfricaMantle - geophysics
DS1975-0470
1977
Brandt, M.L.Brandt, M.L.Geophysical Investigations of a Portion of the Mid-continent Gravity High in Carver and Mcleod Counties, Minnesota.Msc. Thesis, University Minnesota., GlobalMid-continent, Geophysics
DS1984-0491
1984
Brandt, S.Maslovskaya, M.N., Yegorov, K.N., Kolosnitsyna, T.I., Brandt, S.Strontium Isotope Distribution Rubidium Strontium Age and Rare Alkalies of Micas from Yakutian Kimberlites.Doklady Academy of Science USSR, Earth Science Section., Vol. 266, No. 1-6, MAY PP. 149-152.RussiaGeochronology, Mir, Udachnaya
DS2003-0152
2003
Brandt, S.Brandt, S., Klemd, R., Okrusch, M.Ultrahigh temperature metamorphism and multistage evolution of garnet orthopyroxeneJournal of Petrology, Vol. 44,6,pp. 1121-44.NamibiaBlank
DS200412-0200
2003
Brandt, S.Brandt, S., Klemd, R., Okrusch, M.Ultrahigh temperature metamorphism and multistage evolution of garnet orthopyroxene granulites from the Proterozoic Epupa CompleJournal of Petrology, Vol. 44,6,pp. 1121-44.Africa, NamibiaUHP
DS1982-0118
1982
Brandt, S.B.Brandt, S.B., Vladimirov, B.M., et al.Strontium Isotopic Systematics in Kimberlites of YakutiaSoviet Geology, No. 1, PP. 94-103.RussiaGeochemistry, Isotopes, Kimberlite
DS1991-1630
1991
Brandt, S.B.Solovjeva, L.V., Dneprovskaya, M.N., Brandt, S.B.Oxygen, Carbon and Strontium isotopic composition of calcites in garnet megacrysts and carbonatized granulitic xenoliths from the Udachnaya kimberlite pipe, YakutiaProceedings of Fifth International Kimberlite Conference held Araxa June, pp. 558-559RussiaGeochronology, Calcites
DS1983-0366
1983
Brandt, S.S.Kostrovitskii, S.I., Dneprovskaid, L.V., Brandt, S.S., et al.The Correlation of Strontium, Carbon, and Oxygen Isotopic Compositions in car Bonate Components of Yakutian Kimberlites.Doklady Academy of Sciences AKAD. NAUK SSSR., Vol. 272, No. 5, PP. 1223-1225.RussiaIsotope, Geochronology
DS1983-0370
1983
Brandt, S.S.Kostrovitskiy, S.I., Dneprovskaya, L.V., Brandt, S.S., Maslovskaya.Correlations Between Isotopic Compositions of Strontium, Carbon, AndDoklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 272, No. 5, pp. 1223-1225RussiaGeochronology, Strontium, Lead, Carbonate
DS1985-0359
1985
Brandt, S.S.Kostrovitsky, S.I., Dneprovskaya, L.V., Brandt, S.S., Maslovska.Correlation of Strontium, Carbon and Oxygen Isotope Distributions in Carbonates from Kimberlite Pipes of Yakutia.Doklady Academy of Science USSR, Earth Science Section., Vol. 272, No. 1-6, MARCH PP. 205-208.RussiaGeochemistry
DS1989-1029
1989
Brannan, M.Miller, R.D., Steeples, D.W., Brannan, M.Mapping a bedrock surface under dry alluvium with shallow seismicreflectionsGeophysics, Vol. 54, No. 12, December pp. 1528-1534GlobalGeophysics -seismics, Alluvium -general applica
DS1975-0609
1977
Brannan, P.A.Sabater, A., Brannan, P.A.Localization of Probability Zones for Gold and Diamond Prospecting in Venezuelan Guyana Using Radar Imagery, Slar.Venezuela Dir. Geol. Bol. Geological Publishing Esp., No. 7, TOMO 4, PP. 2613-2633.VenezuelaKimberlite, Geophysics
DS1920-0326
1927
Branner, G.C.Branner, G.C.Outlines of Arkansaw Mineral ResourcesArkansaw STATE Geological Survey, 352P.United States, Gulf Coast, ArkansasBlank
DS1920-0431
1929
Branner, G.C.Branner, G.C.Geology of Americas Diamond FieldsPan. American Geol. (des Moines), Vol. 51, No. 5, PP. 339-353.United States, Gulf Coast, Arkansas, Pennsylvania, Great LakesDiamond Occurrences, Geology, History
DS1930-0292
1939
Branner, G.C.Branner, G.C.Wealth of ArkansawArkansaw Geological Survey, 135P.United States, Gulf Coast, ArkansasDiamond Industry Discussed Briefly
DS1930-0293
1939
Branner, G.C.Branner, G.C.State Mineral Survey of ArkansawEconomic Geology, Vol. 34, No. 8, P. 941. (abstract.).United States, Gulf Coast, ArkansasDiamond Occurrence, Geology
DS1940-0042
1942
Branner, G.C.Branner, G.C.Mineral Resources of ArkansawArkansaw Geological Survey Bulletin., No. 6, 101P.United States, Gulf Coast, ArkansasDiamond Occurrences
DS1860-0619
1889
Branner, J.C.Branner, J.C.The Age of Crystalline Rocks of ArkansasAmerican Association Advanced Science, Vol. 37, P. 188. (abstract.).United States, Gulf Coast, Arkansas, PennsylvaniaGeochronology
DS1860-0620
1889
Branner, J.C.Branner, J.C., Brackett, R.N.The Peridotite of Pike County, Arkansas Prarie CreekAmerican Journal of Science, SER. 3, Vol. 38, PP. 50-59. United States, Gulf Coast, Arkansas, PennsylvaniaMineralogy, Petrology
DS1900-0740
1909
Branner, J.C.Branner, J.C.Bibliography of the Geology of ArkansasArkansas Geological Survey Bulletin., PP. 97-164.United States, Gulf Coast, ArkansasBibliography
DS1900-0741
1909
Branner, J.C.Branner, J.C.Some Facts and Corrections Regarding the Diamond Region of Arkansas.Engineering and Mining Journal, Vol. 87, PP. 371-372.United States, Gulf Coast, Arkansas, PennsylvaniaGeology, History
DS202004-0538
2020
Branney, M.J.Taylor, R.N., Favila-Harris, P., Branney, M.J., Farley, E.M.R., Gernon, T.M., Palmer, M.R.Dynamics of chemically pulsing mantle plume.Earth and Planetary Science Letters, Vol. 537, 116182 14p. PdfMantlehotspot

Abstract: Upwelling plumes from the deep mantle have an impact on the Earth's surface for tens to hundreds of millions of years. During the lifetime of a mantle plume, periodic fluctuations in its composition and temperature have the potential to generate changes in the nature and volume of surface volcanism. We constrain the spatial and temporal scale of compositional changes in a plume using high-resolution Pb isotopes, which identify chemical pulses emerging from the Canary Islands hotspot over the last ?15 million years (Myr). Surface volcanism spanning ? 400 km along the island chain changes composition systematically and synchronously, representing a replenishment of the plume head by a distinct mantle flavour on timescales of 3-5 Myr. These low-frequency compositional changes are also recorded by individual volcanoes, and comprise a sequence of closely-spaced isotopic trajectories. Each trajectory is maintained for ?1 Myr and is preceded and followed by ?0.3 Myr transitions to magmas with distinct isotope ratios. Relatively sharp transitions between periods of sustained isotopic stability require discrete yet coherent heterogeneities rising at speeds of ?100-200 km Myr?1 and extending for ?150 km vertically in the conduit. The long-term synchronous changes require larger scale isotopic domains extending ?600 km vertically through in the plume stem. These observations demonstrate that plumes can chemically “pulse” over short and long-timescales reflecting the characteristics and recycling history of the deep mantle.
DS1950-0469
1959
Brannock, W.W.Faul, H., Eldmore, P.L.D., Brannock, W.W.Age of the Fen Carbonatite and its Relation to the Oslo Region.Geochimica Et Cosmochimica Acta, Vol. 17, PP. 153-156.Norway, ScandinaviaUltramafic And Related Rocks
DS1960-0529
1965
Brannock, W.W.Coleman, R.G., Lee, D.E., Beatty, L.B., Brannock, W.W.Eclogites and Eclogites -- their Differences and SimilaritieGeological Society of America (GSA) Bulletin., Vol. 76, No. 5, PP. 483-508.GlobalEclogites
DS1983-0264
1983
Brannon, J.G.Green, J.C., Brannon, J.G.Physical Volcanology of a Proterozoic Continental Rift: The keweenawan North Shore Volcanics, Minnesota.Geological Society of America (GSA), Vol. 15, No. 6, P. 586. (abstract.).GlobalMid Continent
DS201811-2573
2015
Branquet, Y.Giuliani, G., Branquet, Y., Fallick, A.E., Groat, L.A., Marshall, D.Emerald deposits around the world, their similarities and differences.InColor, December pp. 56-69.Globalemeralds
DS201906-1277
2019
Branquet, Y.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.
DS1996-0167
1996
Branson, J.Branson, J., Brown, A.K., Gregory, K.J.Global continental changes: the context of paleohydrologyGeological Society of London, No. 115, 280p. approx. $98.00 United StatesGlobalPaleohydrology, Book -ad
DS1975-0471
1977
Brant, A.D.Brant, A.D.The Diary of Helena MorleyNew York: The Ecco Press, 281P.GlobalKimberley, Janlib, History
DS1995-0203
1995
Brantley, S.L.Brantley, S.L., Koepenick, K.W.Measured carbon dioxide emissions from Oldoinyo Lengai and the skewed distribution of passive volcanic fluxesGeology, Vol. 23, No. 10, October pp. 933-936.TanzaniaCarbonatite, Deposit -Oldoinyo Lengai
DS201112-0107
2011
Brantley, S.L.Brantley, S.L., Lebedeva, M.Learning to read the chemistry of regolith to understand the critical zone.Annual Review of Earth and Planetary Sciences, Vol. 39, pp. 387-416.TechnologyRegolith - geochemistry
DS201312-0172
2013
Braschi, E.Contincelli, S., Avanzinelli, R., Poli, G., Braschi, E., Giordano, G.Shift from lamproite-like to leucitic rocks: Sr-Nd-Pb isotope dat a from the Monte Cimino volcanic complex vs the Vico stratovolcano, central Italy.Chemical Geology, Vol. 353, pp. 246-266.Europe, ItalyLeucites
DS201312-0194
2013
Braschi, E.Conticelli, S., Avanzinelli, R., Poli, G., Braschi, E., Giordano, G.Shift from lamproite-like to leucitic rocks: Sr-Nd-Pb isotope dat a from the Monte Cimino volcanic complex vs the Vico stratovolcano, central Italy.Chemical Geology, Vol. 353, pp. 246-266.Europe, ItalyLamproite
DS200612-0822
2005
Brasier, M.D.Lindsay, J.F., Brasier, M.D., McLoughlin, N., Green, O.R., Fogel, M., Steele, A., Mertzman, S.A.The problem of deep carbon - an Archean paradox.Precambrian Research, Vol. 143,1-4, Dec. 15, pp. 1-22.AustraliaCarbon dykes, geochronology
DS1997-0124
1997
Brasil Depart. Navional de Producao MineralBrasil Depart. Navional de Producao MineralDiamante - statistics and operationsBrasil Depart. Navional de Producao Mineral, pp. 42-43.BrazilDiamond production
DS2003-0153
2003
Brasilica Mining CorporationBrasilica Mining CorporationEnvironmental permit granted on the Baliza area diamond concessions, BrazilBrasilica Mining Corporation, May 29, 1p.Brazil, GoiasPress release
DS200412-0201
2003
Brasilica Mining CorporationBrasilica Mining CorporationEnvironmental permit granted on the Baliza area diamond concessions, Brazil. Araguaia River.Brasilica Mining Corporation, May 29, 1p.South America, Brazil, GoiasNews item - press release
DS200612-0166
2005
Brassines, S.Brassines, S., Balaganskaya, E., Demaiffe, D.Magmatic evolution of the differentiated ultramafic, alkaline and carbonatite intrusion of Vuoriyarvi ( Kola Peninsula) Russia, A LA-ICP-MS study of apatite.Lithos, Vol. 85, 1-4, Nov-Dec. pp. 76-92Russia, Kola PeninsulaMagmatism
DS200512-0110
2005
Brassinnes, S.Brassinnes, S., Balaganskaya, E., Demaiffe, D.Magmatic evolution of the differentiated ultramafic, alkaline and carbonatite intrusion of Vuoriyarvi, Kola Peninsula, Russia, A LA ICP MS study of apatite.Lithos, Advanced in pressRussia, Kola PeninsulaCarbonatite
DS200512-0111
2003
Brassinnes, S.Brassinnes, S., DeMaiffe, D., Balaganskaya, E., Downes, H.New mineralogical and geochemical dat a on the Vuorijarvi ultramafic, alkaline and carbonatitic complex ( Kola Region, NW Russia).Periodico di Mineralogia, (in english), Vol. LXX11, 1. April, pp. 79-86.Russia, Kola PeninsulaMelilite
DS201312-0204
2013
Brassinnes, S.Demaiffe, D., Wiszniewska, J., Krzeminska, E., Williams, I.S., Stein, H., Brassinnes, S., Ohnenstetter, D., Deloule, E.A hidden alkaline and carbonatite province of Early Carboniferous age in northeast Poland: zircon U-Pb and pyrrhotite Re-Os geochronology.Journal of Geology, Vol. 121, 1, pp. 91-104.Europe, PolandCarbonatite
DS1986-0104
1986
Brastad, K.Brastad, K.Relationships between peridotites, anorthosites and eclogites to Bjorkedalen Western NorwayThe Caledonide Orogen-Scandinavia and Related areas, Gee, D.G. Sturt, B.A., pp. 843-872NorwayEclogites, Peridotite
DS1980-0253
1980
Bratosin, I.Nikitin, I., Bratosin, I.Deformation of Wallrocks During Kimberlite Pipe FormationIzvest. Akad. Nauk Sssr Geol. Ser., Vol. 1980, No. 11, PP. 41-49.RussiaBlank
DS1987-0077
1987
Bratus, M.D.Bratus, M.D., Tatarini, V.I., Sakhno, B.E.Composition of fluid inclusions in the quenched particles from the explosive ring like structures and kimberlite pipes.(Russian)Geochemistry International (Geokhimiya), (Russian), No. 11, November pp. 1563-1568RussiaBlank
DS1990-0234
1990
Bratus, M.D.Bratus, M.D., Zinchuk, N.N., Argunov, K.P., Svoren, Y.M.Composition of fluid inclusions in Yakutian diamond crystals.(Russian)Mineral. Zhurn., (Russian), Vol. 12, No. 4, August pp. 49-56RussiaDiamond morphology, Diamond inclusions
DS1991-0166
1991
Bratus, M.D.Bratus, M.D., Svoren, I.M., Zinchuk, N.N., Argunov, K.P.Fluid inclusion gas components in the different morphological types Of diamonds from Yakutia.(Russian)Geochemistry International (Geokhimiya), (Russian), No. 11, pp. 1586-1595Russia, YakutiaDiamond morphology, Geochemistry, inclusions
DS1992-0158
1992
Bratus, M.D.Bratus, M.D., Svoren, Y.M., Zinchuk, N.N., Argunov, K.P.Gas components of inclusions in Yakutian diamondsGeochemistry International, Vol. 29, No. 6, pp. 69-78Russia, YakutiaDiamond inclusions, Geochemistry
DS1997-0125
1997
Bratus, M.D.Bratus, M.D., Zinchuk, N.N., Svoren, I.M., Argunov, K.Gases from Yakutian polycrystalline diamondsDoklady Academy of Sciences, Vol. 355, No. 5, Jun-July pp. 757-9.Russia, YakutiaDiamond inclusions
DS1998-0159
1998
Bratus, M.D.Bratus, M.D., Zinchuk, N.N., Krouse, G.R., Vityk, M.O.Crystallization conditions and sulfur, carbon and oxygen isotopic systematics of sulfide calcite AssociationGeochemistry International, Vol. 36, No. 3, pp. 222-228.Russia, YakutiaGeology, diamond morphology, fluid inclusions, Deposit - Udachnaya, Geochronology
DS201112-0522
2011
Brauch, K.Klaudis, J., Symons, G., Burton, D., Brauch, K.The application of airborne, ground and borehole geophysics to the exploration of the Lofdal carbonatite complex.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterAfrica, NamibiaCarbonatite
DS201412-0038
2014
Braucher, R.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
DS200812-0136
2007
Brauer, B.Brauer, B., Ryberg, T., Lindeque, A.S.Shallow seismic velocity structure of the Karoo Basin, South Africa.South African Journal of Geology, Vol. 110, 2-3, Sept. pp. 439-448.Africa, South AfricaGeophysics - seismics
DS201908-1772
2019
Braukmuller, N.Braukmuller, N., Wombacher, F., Funk, C., Munker, C.Earth's volatile element depletion pattern inherited from a carbonaceous chondrite-like source.Nature Geoscience, Vol. 12, 7, pp. 564-568.Mantlechondrite

Abstract: Earth’s volatile element abundances (for example, sulfur, zinc, indium and lead) provide constraints on fundamental processes, such as planetary accretion, differentiation and the delivery of volatile species, like water, which contributed to Earth becoming a habitable planet. The composition of the silicate Earth suggests a chemical affinity but isotopic disparity to carbonaceous chondrites—meteorites that record the early element fractionations in the protoplanetary disk. However, the volatile element depletion pattern of the silicate Earth is obscured by core formation. Another key problem is the overabundance of indium, which could not be reconciled with any known chondrite group. Here we complement recently published volatile element abundances for carbonaceous chondrites with high-precision sulfur, selenium and tellurium data. We show that both Earth and carbonaceous chondrites exhibit a unique hockey stick volatile element depletion pattern in which volatile elements with low condensation temperatures (750-500?K) are unfractionated from each other. This abundance plateau accounts for the apparent overabundance of indium in the silicate Earth without the need of exotic building materials or vaporization from precursors or during the Moon-forming impact and suggests the accretion of 10-15?wt% CI-like material before core formation ceased. Finally, more accurate estimates of volatile element abundances in the core and bulk Earth can now be provided.
DS200412-0298
2004
Braun, I.Cenki, B., Braun, I., Brocker, M.Evolution of the continental crust in the Kerala Khondalite belt, southernmost India: evidence from Nd isotope mapping, U Pb andPrecambrian Research, Vol. 134, 3-4, Oct. 22, pp. 275-292.IndiaMetamorphism, Geochronology
DS200612-1449
2006
Braun, I.Upadhyay, D., John-Awe, S., Pin, C., Paquette, J.L., Braun, I.Neoproterozoic alkaline magmatism at Sivamalai, southern India.Gondwana Research, Vol. 10, 1-2, August pp. 156-166.IndiaAlkalic
DS1994-0437
1994
Braun, I.V.Dobrzhinetskaya, L.F., Braun, I.V., Sheskel, G.G., Podkuiko, Y.A.Geology and structure of diamond bearing rocks of the Kokchetav Massif, Kazahkstan.Tectonophysics, Vol. 233, No. 3-4, May 30, pp. 293-313.Russia, KazahkstanStructure, Diamondiferous rocks
DS1989-0169
1989
Braun, J.Braun, J., Beaumont, C.A physical explanation of the relation between flank uplifts and the breakup unconformity at rifted continental marginsGeology, Vol. 17, No. 8, August pp. 760-764GlobalTectonics, Rift
DS1991-0167
1991
Braun, J.Braun, J., McQueen, H., Etheridge, M.A fresh look at the late Paleozoic tectonic history of western centralAustralia8th. Australian Society of Exploration Geophysicists (ASEG) Conference, Vol. 22, No. 1, March pp. 49-54AustraliaTectonics, Geophysics
DS1992-0159
1992
Braun, J.Braun, J.Post extensional mantle healing and episodic extension in the CanningBasinJournal of Geophysical Research, Vol. 97, No. B6, June 10, pp. 8927-8936AustraliaMantle tectonics, Canning Basin
DS1992-0216
1992
Braun, J.Caritat, P., Braun, J.Cyclic development of sedimentary basins at convergent plate margins -1.structural and tectonothermal evolution of some Gondwana basins of easternAustraliaJournal of Geodynamics, Vol. 16, No. 4, December pp. 241-AustraliaGondwanaland, Basins
DS1992-0349
1992
Braun, J.De Caritat, P., Braun, J.Cyclic development of sedimentary basins at convergent plate margins - 1.structural and tectono-thermal evolution of some Gondwana Basins of easternAustraliaJournal of Geodynamics, Vol. 16, No. 4, pp. 241-282AustraliaBasins, Structure
DS1995-0204
1995
Braun, J.Braun, J., Beaumont, C.Three dimensional numerical experiments of strain partitioning at oblique plate boundaries:Journal of Geophysical Research, Vol. 100, No. B9, pp. 18, 059-74.California, New ZealandTectonics
DS1998-0160
1998
Braun, J.Braun, J., Dooley, J., Goleby, B., Van der Hilst et al.Structure and evolution of the Australian continentAmerican Geophysical Union (AGU) Geodynamic Series, Vol. 26, 186p. app. $ 42.00AustraliaMantle - lithosphere, structure, Tectonics
DS1998-0161
1998
Braun, J.Braun, J., Shaw, R.Extension in the Fitsroy Trough, western Asutralia: an example of reactivation tectonics.Structure EVol. Austral., American Geophysical Union (AGU) geodynamics Vol. 26, pp. 157-174.AustraliaTectonics
DS2001-0132
2001
Braun, J.Braun, J., Shaw, R.A thin plate model of Paleozoic deformation of Australian lithosphere: implications for cratonizationGeological Society of London Special Publication, Special Paper 184, pp.AustraliaTectonics, Orogenesis, reactivation, reworking
DS2001-0334
2001
Braun, J.Fredericksen, S., Braun, J.Numerical modelling of strain localisation during extension of the continental lithosphere.Earth and Planetary Science Letters, Vol. 188, No. 1, May 30, pp. 241-51.MantleModeling - tectonics
DS200612-0167
2006
Braun, J.Braun, J., Van der Beek, P., Batt, G.Quantitative thermochronology. Numerical methods for the interpretation of thermochronologic data. Case studies, review of isotopic ages.cambridge.org/us/earth, 232p. $ 100.00 ISBN 10-0521830575TechnologyBook - geochronology, geothermometry
DS200912-0071
2009
Braun, J.Braun, J., Burbidge, D.R., Gesto, Sandford, Gleadow, Kohn, CumminsConstraints on the current rate of deformation and surface uplift of the Australian continent from a new seismic database and low T thermochronological data.Australian Journal of Earth Sciences, Vol. 56, 2, pp. 99-110.AustraliaGeophysics - seismic
DS201412-0068
2014
Braun, J.Braun, J., Guillocheau, F., Robin, C., Baby, Guillaume, JelsmaRapid erosion of the southern African plateau as it climbs over a mantle superswell.Journal of Geophysical Research,, Vol. 119, 7, pp. 6093-6112.Africa, southern AfricaGeomorphology
DS2003-0154
2003
Braun, M.G.Braun, M.G., Sohn, R.A.Melt migration in plume ridge systemsEarth and Planetary Science Letters, Vol. 213, 3-4, pp. 417-30.GlobalTectonics - not specific to diamonds
DS200412-0202
2003
Braun, M.G.Braun, M.G., Sohn, R.A.Melt migration in plume ridge systems.Earth and Planetary Science Letters, Vol. 213, 3-4, pp. 417-30.GlobalTectonics - not specific to diamonds
DS200712-0103
2007
Braunb, A.Braunb, A., Kim, H-R., Csatho, B., Von Frese, R.R.B.Gravity inferred crustal thickness of Greenland.Earth and Planetary Science Letters, Vol. 262, 1-2, pp. 138-158.Europe, GreenlandGeophysics - seismics
DS201112-0523
2011
Braunch, K.Klaudius, J., Braunch, K.The application of airborne, ground and borehole geophysics to the exploration for rare earth elements associated with the Lofdal carbonatite complex, NamibiaPeralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.69. (very brief no info)Africa, NamibiaGeophysics
DS201112-0524
2011
Braunch, K.Klaudius, J., Braunch, K.The application of airborne, ground and borehole geophysics to the exploration for rare earth elements associated with the Lofdal carbonatite complex, NamibiaPeralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.69. (very brief no info)Africa, NamibiaGeophysics
DS200812-0993
2007
Braundedr, K.Sader, J.S., Hamilton, S.M., Hattori, K.H., Braundedr, K.Project unit: 07-32. Surface media geochemical sampling at the Victor kimberlite region, northern Ontario and the Kirkland Lake region northeastern Ontario.Ontario Geological Survey Open File, No. 6213, pp. 19-1-6.Canada, OntarioOverview field work
DS201112-0897
2011
Brauneder, K.Sader, J.A., Hattori, K.H., Kong, J.M., Hamilton, S.M., Brauneder, K.Geochemical responses in peat groundwater over Attawapiskat kimberlites, James Bay Lowlands, Canada and their application to diamond exploration.Geochemistry, Exploration, Environment, Analysis:, Vol. 11, pp. 193-210.Canada, Ontario, James Bay LowlandsGeochemistry
DS201312-0769
2013
Brauneder, K.Sader, J.A., Hattori, K., Brauneder, K., Hamilton, S.M.The influence of buried kimberlite on methane production in overlying sediment, Attawapiskat region, James Bay lowlands, Ontario.Chemical Geology, Vol. 360-361, pp. 173-185.Canada, Ontario, AttawapiskatMethane
DS201811-2617
2018
Braunger, S.Walter, B.F., Parsapoor, A., Braunger, S., Marks, M.A.W., Wenzel, T., Martin, M., Markl, G.Pyrochlore as a monitor for magmatic and hydrothermal processes in carbonatites from the Kaiserstuhl volcanic complex ( SW Germany).Chemical Geology, Vol. 498, pp. 1-16.Europe, Germanycarbonatite

Abstract: Pyrochlore from the Kaiserstuhl volcanic complex (SW Germany) shows textural and compositional differences between various coarse-grained calcite-carbonatite bodies (Badberg, Degenmatt, Haselschacher Buck, Orberg) and extrusive carbonatites (Henkenberg, Kirchberg). Oscillatory-zoned F-rich pyrochlore with up to 69?wt% Nb2O5 is common in all coarse-grained calcite-carbonatite bodies and probably formed during magmatic conditions. However, only in some of the samples from the Badberg, partly resorbed U- and Ta-enriched pyrochlore cores with up to 22?wt% UO2 and 9?wt% Ta2O5 have been identified, which are interpreted as being inherited from underlying nosean syenites. Pyrochlore data from a drill core penetrating the Badberg indicate increasing contents of REE, U, and Ta with depth, while Nb, F and Na contents decrease. This may reflect the combined effects of fractional crystallization and assimilation (AFC) or indicates a multi-stage emplacement of the carbonatitic magma. Patchy-zoned ceriopyrochlore and REE- and Th-enriched pyrochlore with up to 19?wt% total REE2O3 and 6.5?wt% ThO2 is largely restricted to samples from the Orberg and probably formed during hydrothermal conditions. This can be related to the relatively evolved character of the Orberg carbonatites, based on their relatively high whole-rock Nb/Ta and Zr/Hf mass ratios. This study demonstrates that the textural and compositional variation of pyrochlore in carbonatites is a powerful tool to distinguish magmatic, hydrothermal and weathering processes in carbonatitic systems.
DS201909-2024
2019
Braunger, S.Braunger, S., Marks, M.A.W., Wenzel, T., Chmyz, L., Azzone, R.G., Markl, G.Carbonatite-alkaline silica rock complexes reflect highly oxidized conditions in their Upper Mantle source.Goldschmidt2019, 1p. AbstractMantlecarbonatite

Abstract: Alkaline complexes consist of variable mantle-derived silicate rocks, ranging from primitive alkali basalts, melilitites, nephelinites and basanites towards tephrites and more evolved phonolites, respectively their plutonic equivalents. This lithological variance is also expressed by a wide range of redox conditions that vary by several log units around the synthetic fayalite-magnetite-quartz (FMQ) buffer. However, only some of these complexes are characterized by the occurrence of carbonatites which must be related to specific formation conditions. Based on textural, mineralogical and geochemical observations, we calculated the redox conditions of carbonatites and associated silicate rocks for seven alkaline complexes (Kaiserstuhl, Sokli, Kovdor, Palabora, Magnet Cove, Oka, Jacupiranga) which are considered to represent typical carbonatite-alkaline silicate rock associations. In combination with a comprehensive literature review, we demonstrate that carbonatite-bearing alkaline complexes formed under highly oxidized conditions and hence, belong to the most oxidized alkaline rocks at all. This is consistent with the prerequisite of a carbonated mantle as the source region for carbonatite complexes, which requires redox conditions distinctively above that for mean lithospheric or asthenospheric mantle. Carbonatitemetasomatized peridotites also show high redox conditions and might not only reflect an interaction between peridotite and carbonatitic melts/fluids, but at least partly represent the carbonated mantle source for crustally emplaced carbonatite complexes. We therefore suggest that the oxidation state of carbonatites and associated silicate rocks provides direct information about an extraordinary oxidized parental mantle source.
DS201909-2042
2019
Braunger, S.Giebel, R.J., Parsapoor, A., Walter, B.F., Braunger, S., Marks, M.A.W.Evidence for magma-wall rock interaction in carbonatites from the Kaiserstuhl volcanic complex ( southwest Germany).Journal of Petrology , Vol. 60, 6, pp. 1163-1194.Europe, Germanycarbonatite

Abstract: The mineralogy and mineral chemistry of the four major sövite bodies (Badberg, Degenmatt, Haselschacher Buck and Orberg), calcite foidolite/nosean syenite xenoliths (enclosed in the Badberg sövite only) and rare extrusive carbonatites of the Kaiserstuhl Volcanic Complex in Southern Germany provide evidence for contamination processes in the carbonatitic magma system of the Kaiserstuhl. Based on textures and composition, garnet and clinopyroxene in extrusive carbonatites represent xenocrysts entrained from the associated silicate rocks. In contrast, forsterite, monticellite and mica in sövites from Degenmatt, Haselschacher Buck and Orberg probably crystallized from the carbonatitic magma. Clinopyroxene and abundant mica crystallization in the Badberg sövite, however, was induced by the interaction between calcite foidolite xenoliths and the carbonatite melt. Apatite and micas in the various sövite bodies reveal clear compositional differences: apatite from Badberg is higher in REE, Si and Sr than apatite from the other sövite bodies. Mica from Badberg is biotite- and comparatively Fe2+-rich (Mg# = 72-88). Mica from the other sövites, however, is phlogopite (Mg# up to 97), as is typical of carbonatites in general. The typical enrichment of Ba due to the kinoshitalite substitution is observed in all sövites, although it is subordinate in the Badberg samples. Instead, Badberg biotites are strongly enriched in IVAl (eastonite substitution) which is less important in the other sövites. The compositional variations of apatite and mica within and between the different sövite bodies reflect the combined effects of fractional crystallization and carbonatite-wall rock interaction during emplacement. The latter process is especially important for the Badberg sövites, where metasomatic interaction released significant amounts of K, Fe, Ti, Al and Si from earlier crystallized nosean syenites. This resulted in a number of mineral reactions that transformed these rocks into calcite foidolites. Moreover, this triggered the crystallization of compositionally distinct mica and clinopyroxene crystals around the xenoliths and within the Badberg sövite itself. Thus, the presence and composition of clinopyroxene and mica in carbonatites may be useful indicators for contamination processes during their emplacement. Moreover, the local increase of silica activity during contamination enabled strong REE enrichment in apatite via a coupled substitution involving Si, which demonstrates the influence of contamination on REE mineralization in carbonatites.
DS201909-2061
2019
Braunger, S.Marks, M.A.W., Giebel, R.J., Walter, B.F., Braunger, S., Wenzel, T., Markl, G.Evidence for wall-rock assimilation in carbonatites from the Kaiserstuhl (German).Goldschmidt2019, 1p. AbstractEurope, Germanydeposit - Kaiserstuhl

Abstract: Contamination of carbonatites with crustal or cogenetic intrusive rocks is generally not considered to play an important role during carbonatite magmatism, because carbonatitic melts have low densities and viscosities, enabling them to rapidly ascend. Potential contamination by silicate rocks in carbonatites cannot easily be detected by means of radiogenic isotope data (such as Sr, Nd and Pb isotope data) as carbonatites often show high concentrations of these elements and their isotope systems are thereby “buffered” against contamination with silicate rocks. Textural, mineralogical and geochemical observations in carbonatites from the Kaiserstuhl (Germany) provide evidence for the interaction of carbonatitic magma with previously emplaced nosean syenites. This caused replacement of alkali feldspar by haüyne and recrystallization of garnet and clinopyroxene in the xenoliths, which released larger amounts of K, Al, Si and Fe. As a result, blackwall-like mica seams around the xenoliths formed and and compositionally distinct mica and clinopyroxene crystallized in the surrounding carbonatite. Moreover, the local increase of silica activity during contamination enabled strong REE enrichment in apatite via a coupled substitution involving Si, which demonstrates the potential influence of Si contamination on REE mineralization in carbonatites. We further suggest that the presence and composition of clinopyroxene and mica in carbonatites may be useful indicators for contamination processes during their emplacement. Mass-balance calculations based on experimental constraints for the solubility of Al and Si in carbonatitic magmas suggest that only minor amounts of mica can form from carbonatitic melt. Therefore, larger amounts of mica and mica-dominated lithologies (glimmerites) as observed in many carbonatite complexes suggest that some Si and Al in carbonatites may be sourced from surrounding host rocks. We hypothesize that assimilation and contamination processes in carbonatites may be the rule rather than an exception.
DS202002-0168
2020
Braunger, S.Braunger, S., Marks, M.A.W., Wenzel, T., Chmyz, L., Azzone, R.G., Markl, G.Do carbonatites and alkaline rocks reflect variable redox conditions in their upper mantle source? ( metasomatism)Earth and Planetary Science Letters, Vol. 533, 11p. PdfMantlecarbonatite

Abstract: A detailed investigation on seven carbonatites and associated alkaline rock complexes (Kaiserstuhl, Sokli, Kovdor, Palabora, Oka, Magnet Cove, Jacupiranga), together with a world-wide comparison between carbonatites, alkaline silicate rocks and mantle xenoliths, implies peculiar redox conditions for carbonatite-bearing alkaline complexes: Carbonatites and associated alkaline rocks in continental settings crystallize from relatively oxidized magmas, on average 1.4 log units () and 1.3 log units () above the synthetic fayalite-magnetite-quartz (FMQ) buffer. In contrast, alkaline rocks in continental settings that lack associated carbonatites reveal rather reduced conditions (mean ; ). The calculated redox conditions for carbonatites and associated silicate rocks demonstrate that these crystallize from relatively oxidized mantle-derived melts compared to the general range found for alkaline rocks in continental settings.
DS1996-0168
1996
Braunmiller, J.Braunmiller, J., Nabalek, J.Geometry of continental normal faults: seismological constraintsJournal of Geophysical Research, Vol. 181, No. B2, Feb. 10, pp. 3045-52GlobalTectonics, Continental faults
DS1996-0169
1996
Braunmiller, J.Braunmiller, J., Nabelek, J.Geometry of continental normal faults: seismological constraintsJournal of Geophysics Research, Vol. 101, No. 2, Feb. 10, pp. 3045-52.GlobalStructure -faults, Continental faults
DS200712-0104
2006
Braunmiller, J.Braunmiller, J., Van der Lee, S., Doermann, L.Mantle transition zone thickness in the central South American subduction zone.American Geophysical Union, Geophysical Monograph, No. 168, pp. 215-224.South AmericaSubduction
DS2001-0143
2001
Brauns, C.M.Buhn, B., Dorr, W., Brauns, C.M.Petrology and age of Otjisazu carbonatite complex: implications pre- and syJournal of African Earth Sciences, Vol. 32, No. 1, Jan. pp. 1-18.NamibiaCarbonatite
DS1988-0081
1988
Braunstein, J.Braunstein, J., Huddlestun, P., Biel, R.Gulf Coast regionCosuna, Correlation Of Stratigraphic Units Of North America Project, American Association of Petroleum Geologists, Cat. No. 710, COSUNA No. 10, 1, 41 X 55 $10MidcontinentStratigraphy, Map
DS1998-0162
1998
Brawn, J.Brawn, J., et al.Structure and evolution of the Australian continentAmerican Geophysical Union (AGU) geodynamics series, Vol. 26, 186p. $ 42.00AustraliaTable of contents, Geodynamics - tectonics
DS2002-1377
2002
Bray, G.P.Ryabchikov, I.D., Solovova, I.P., Kogarko, L.N., Bray, G.P., Ntaflos, Th.Thermodynamic parameters of generation of meymechites and alkaline picrites in theGeochemistry International, Vol. 40, 11, pp. 1031-41.RussiaPicrites, meymechites
DS1996-0170
1996
Bray, J.Bray, J.Business security outlook 1996International Gold Mining Newsletter, Vol. 23, No. 1, Jan. pp. 10-13GlobalCountry ranking, Economics
DS1996-0171
1996
Bray, J.Bray, J.Political risk assessment in global miningMining Engineering, Vol. 48, No. 1, Jan. p. 9GlobalEconomics, Legal, political
DS202102-0202
2021
Brazhkin, V.V.Litasov, K.D., Kagi, H., Bekker, T.B., Makino, Y., Hirata, T., Brazhkin, V.V.Why Tolbachik diamonds cannot be natural.The American Mineralogist, Vol. 106. pp. 44-53. pdfRussiadeposit - Kamchatka

Abstract: Taking into account recent publications, we provide additional comprehensive evidence that type Ib cuboctahedral diamonds and some other microcrystalline diamonds from Kamchatka volcanic rocks and alluvial placers cannot be natural and undoubtedly represent synthetic materials, which appear in the natural rocks by anthropogenic contamination. The major arguments provided in favor of the natural origin of those diamonds can be easily disproved. They include the coexistence of diamond and deltalumite from Koryaksky volcano; coexistence with super-reduced corundum and moissanite, Mn-Ni silicide inclusions, F-Cl enrichment and F/Cl ratios, and carbon and nitrogen isotopes in Tolbachik diamonds, as well as microtwinning, Mn-Ni silicides, and other inclusions in microcrystalline diamond aggregates from other Kamchatka placers. We emphasize the importance of careful comparison of unusual minerals found in nature, which include type Ib cuboctahedral diamonds and super-reduced phase assemblages resembling industrial slags, with synthetic analogs. The cavitation model proposed for the origin of Tolbachik diamonds is also unreliable since cavitation has only been shown to cause the formation of nanosized diamonds only.
DS2000-0106
2000
Brazier, R.A.Brazier, R.A., Nyblade, A.A., Owens, T.J.Pn wave velocities beneath the Tanzania Craton and adjacent rifted mobile belts, East Africa.Geophysical Research Letters, Vol. 27, No. 16, Aug. 15, pp. 2365-8.TanzaniaGeophysics - seismic, Tectonics - rifting
DS2002-1167
2002
Brazier, R.A.Nyblade, A.A., Brazier, R.A.Precambrian lithospheric controls on the development of the East African rift systemGeology, Vol.30,8,Aug.pp.755-8.Africa, East AfricaTectonics
DS2003-0155
2003
Brazier, R.A.Brazier, R.A., Nyblade, A.A.Upper mantle P velocity structure beneath the Baikal Rift from modeling regionalGeophysical Research Letters, Vol. 30, 4, Feb. 15, DOI 10.1029/2002GLO16115RussiaTectonics
DS200412-0203
2003
Brazier, R.A.Brazier, R.A., Nyblade, A.A.Upper mantle P velocity structure beneath the Baikal Rift from modeling regional seismic data.Geophysical Research Letters, Vol. 30, 4, Feb. 15, DOI 10.1029/2002 GLO16115RussiaGeophysics - seismics Tectonics
DS201502-0045
2014
Brazil diamond mapBrazil diamond mapMap of diamonds from the Patos Meeting.Mapa Simposio APL Diamantes A3 QT.pdf, pdf available 12306KSouth America, BrazilDiamond locations in A.P.
DS1970-0252
1971
Brazul'kina, V.A.Brazul'kina, V.A.Chemical Composition of Kimberlites. #1Geochemistry International (Geokhimiya)., No. 1.RussiaBlank
DS200712-0105
2007
BRC Diamond CorporationBRC Diamond CorporationBRC Diamond and Diamond Core update merger progress.BDRC Diamond Corporation, Sept. 7, 1p.Africa, Democratic Republic of CongoNews item - press release, Diamond Core
DS200612-0222
2006
Breakspear, R.M.D.Carling, P.A., Breakspear, R.M.D.Placer formation in gravel bedded rivers: a review.Ore Geology Reviews, Vol. 28, 4, pp. 377-401.GlobalAlluvials, heavy minerals, bedforms, principles
DS2003-0219
2003
Bream, B.R.Carrigan, C.W., Miller, C.F., Fullagar, P.D., Bream, B.R., Hatcher, R.D., CoathIon microprobe age and geochemistry of southern Appalachian basement, withPrecambrian Research, Vol. 120, 1-2, pp. 1-36.Appalachia, United StatesGeochronology
DS200412-0285
2003
Bream, B.R.Carrigan, C.W., Miller, C.F., Fullagar, P.D., Bream, B.R., Hatcher, R.D., Coath, C.D.Ion microprobe age and geochemistry of southern Appalachian basement, with implications for Proterozoic and Paleozoic reconstrucPrecambrian Research, Vol. 120, 1-2, pp. 1-36.United StatesGeochronology
DS200812-0452
2007
Bream, B.R.Hatcher, R.D., Bream, B.R., Merschat, A.J.Tectonic map of the southern and central Appalachians: a tale of three orogens and a complete Wilson cycle.Geological Society of America, Memoir, No. 200, pp. 595-632.United States, AppalachiaTectonics
DS1992-0160
1992
Brearley, A.J.Brearley, A.J., Rubie, D.C.Mechanisms of the transformation of modified spinel to spinel at highpressureGeological Society of America (GSA) Abstracts with programs, 1992 Annual, Vol. 24, No. 7, abstract p. A258MantleSpinel, Transition zone
DS1994-1493
1994
Brearley, A.J.Rubie, D.C., Brearley, A.J.Phase transitions between magnesium iron SiO4 in the earth's mantle: mechanisms and rheological implications.Science, Vol. 264, No. 5164, June 3, pp. 1445-1447.MantleBlank
DS1999-0092
1999
Brearley, A.J.Brearley, A.J.Origin of graphite carbon and pentlandite in matrix olivines in the Allendemeteorite.Science, Vol. 285, No. 5432, Aug. 27, pp. 1380-1.GlobalMeteorites, Sulphides, olivines
DS200712-0969
2007
Brearley, A.J.Sharp, Z.D., Barnes, J.D., Brearley, A.J., Chaussidon, M., Fischer, T.P., Kamenetsky, V.S.Chlorine isotope homogeneity of the mantle, crust and carbonaceous chondrites.Nature, Vol. 446, 7139, pp. 1062-1065.MantleGeochronology
DS1984-0173
1984
Brearley, M.Brearley, M., Scarfe, C.M.Amphibole in a Spinel Lherzolite Xenolith - Evidence for Volatiles and Partial Melting in the Upper Mantle Beneath Southern British Columbia.Canadian Journal of Earth Sciences, Vol. 21, No. 9, SEPTEMBER PP. 1067-1072.Canada, British ColumbiaBlank
DS1984-0174
1984
Brearley, M.Brearley, M., Scarfe, C.M., Fujii, T.The Petrology of Ultramafic Xenoliths from Summit Lake, Near Prince George British Columbia.Contributions to Mineralogy and Petrology, Vol. 88, PP. 53-63.Canada, British ColumbiaBasanite, Microprobe Analyses, Nodules, Spinel Lherzolite, Wehrlite
DS1986-0105
1986
Brearley, M.Brearley, M., Scarfe, C.Dissolution rates of upper mantle minerals in an alkali basalt melt at high pressure: an experimental study and implications for ultramafic xenolithsurvivalJournal of Petrology, Vol. 27, No. 5, pp. 1157-1182South AfricaHawaii, Roberts Victor
DS1987-0084
1987
Brearley, M.Canil, D., Brearley, M., Scarfe, C.M.Petrology of ultramafic xenoliths from Rayfield River southcentral British ColumbiaCanadian Journal of Earth Sciences, Vol. 24, No. 8, August pp. 1679-1687British ColumbiaMantle, Heat flow
DS2001-0798
2001
Breddam, K.Moreira, M., Breddam, K., Curtice, J., Kurz, M.D.Solar neon in the Icelandic mantle: new evidence for an under gassed lower mantle.Earth and Planetary Science Letters, Vol. 185, No. 1-2, Feb.15, pp. 15-23.GlobalMantle - geochemistry, geochronology
DS2002-0201
2002
Breddam, K.Breddam, K.Kistufell: primitive melt from the Iceland mantle plumeJournal of Petrology, Vol. 43, No. 2, pp. 345-74.IcelandPlume, hot spot
DS200412-1513
2004
Breddam, K.Peate, D.W., Baker, J.A., Breddam, K., Waight, T.E., Skovgaard, A.C., Stecher, O., Prestvik, T., JonassonPb isotope heterogeneity of the mantle beneath Iceland.Geochimica et Cosmochimica Acta, 13th Goldschmidt Conference held Copenhagen Denmark, Vol. 68, 11 Supp. July, ABSTRACT p.A569.Europe, IcelandGeochronology
DS200712-0824
2006
Breddam, K.Peate, D.W., Breddam, K., Baker, J.A., Kurz, M., Grassineau, N., Barker, A.K.Compositional features of enriched Icelandic mantle components.Geochimica et Cosmochimica Acta, In press availableEurope, IcelandGeochemistry
DS1995-0205
1995
Bredikhin, A.V.Bredikhin, A.V., Panin, A.V.Experience in the development and use of a geology geomorphology block in a geographic information systemMapping Sciences and Remote Sensing, Vol. 32, No. 1, Jan-Mar pp. 50-58RussiaRemote Sensing, GIS
DS201112-0108
2011
Breeding, C.Breeding, C.Hydrogen rich diamonds from Zimbabwe with natural radiation features.GIA International Symposium 2011, Gems & Gemology summer issue Poster session abs. p.129.Africa, ZimbabweTechnology
DS201412-0069
2014
Breeding, C.Breeding, C.Characterization of gem diamonds from eastern Zimbabwe.ima2014.co.za, PosterAfrica, ZimbabweMineralogy
DS201601-0007
2015
Breeding, C.Breeding, C.Diamond bearing eclogite xenoliths from the Ardo So Ver dykes. ( Kimberley area)Gems & Gemology News International, Vol. 51, 2, summer 2p.Africa, South AfricaDeposit - Ardo so Ver
DS202104-0573
2021
Breeding, C.Eaton-Magana, S., Ardon, T., Breeding, C., Shigley, J.D-Z Diamonds ( Ardon presents the information from the article in Gems & Gemology **** see ref under Ahline same one…….gia.org and knowledge session utube, March GlobalDiamond colour

Abstract: Did you know that certain diamonds can temporarily change color when exposed to heat, ultraviolet light, or even when kept in the dark? Some natural greenish diamonds are known as “chameleon” diamonds due to this property. Other natural pink diamonds and some color-treated and laboratory-grown diamonds can also change color in unexpected ways. Before this phenomenon was known, there were stories of customers returning diamonds they purchased because the diamonds turned out to be the “wrong” color! What exactly causes these interesting diamonds to shift their hues? Find out as GIA senior manager of diamond research Dr. Ulrika D'Haenens-Johansson and senior research scientist Dr. Mike Breeding dive into the mystery of these ultra-cool gems.
DS200412-1804
2004
Breeding, C.M.Shigley, J.E., McClure, S.F., Breeding, C.M., Hsi-tien Shen, A., Muhlmeister, S.M.Lab grown coloured diamonds from Chatham created gems. Identifying characteristics of yellow, blue, green and pink synthetic diaGems & Gemology, Vol. 40, 2, Summer, pp.128-145.ChinaDiamond synthesis
DS200512-0979
2004
Breeding, C.M.Shigley, J. E., Breeding, C.M., Hsi-Tien Shen, A.An updated chart on the characteristics of HPHT grown synthetic diamonds.Gems & Gemology, Vol. 40, 4, Winter, pp. 312.Synthetic diamond identification
DS200512-1167
2005
Breeding, C.M.Wang, W., Smith, C.P., Hall, M.S., Breeding, C.M., Moses, T.M.Treated color pink to red diamonds from Lucent Diamonds Inc.Gems & Gemology, Vol. 41, 1, Spring pp. 6-19.Diamond - treatment, Lucent
DS200612-0168
2005
Breeding, C.M.Breeding, C.M., Shigley, J.E., Shen, A.H.As grown green synthetic diamonds.Journal of Gemmology, Vol. 29, 7/8, pp. 387-394.Technology
DS200612-0169
2006
Breeding, C.M.Breeding, C.M.High energy ultraviolet luminescence imaging applications of the DTC diamodnView for gem identification.GIA Gemological Research Conference abstract volume, Held August 26-27, p. 25. 1/2p.TechnologyUV fluorescence
DS200612-0521
2006
Breeding, C.M.Hainschwang, T., Notari, F., Fritsch, E., Massi, L., Breeding, C.M., Rondeau, B.Natural CO2 rich colored diamonds.GIA Gemological Research Conference abstract volume, Held August 26-27, p. 33. 1/2p.TechnologySpectroscopy
DS200812-0310
2007
Breeding, C.M.Eaton-Magana, S., Post, J.E., Heaney, P.J., Walters, R.A., Breeding, C.M., Butler, J.E.Fluorescence spectra of colored diamonds using a rapid, mobile spectrometer.Gems & Gemology, Vol. 43, 4, Winter pp. 332-351.TechnologyType 1 a diamonds
DS200812-1176
2008
Breeding, C.M.Titkov, S.V., Shigley, J.E., Breeding, C.M., Mineeva, R.M., Zudin, N.G., Sergeev, A.M.Natural color purple diamonds from Siberia. Mir field.Gems & Gemology, Vol. 44, 1, spring pp. 56-64.Russia, SiberiaDiamond - purple
DS200812-1238
2007
Breeding, C.M.Wang, W., Hall, M., Breeding, C.M.Natural TYPE 1A diamond with green yellow colour due to Ni related defects.Gems & Gemology, Fall, pp. 240-243.TechnologyDiamond - IA
DS200912-0072
2009
Breeding, C.M.Breeding, C.M., Shigley, J.E.The 'type' classification system of diamonds and its importance in gemology. A guide to determining diamond type, and its implications for identifying treated andGems & Gemology, Vol. 45, 2, Summer, pp. 96-111.TechnologyDiamond classification Type 1 and type 11; synthetics
DS201212-0664
2012
Breeding, C.M.Skalwold, E.A., Renfro, N.,Shigley, J.E., Breeding, C.M.Characterization of a synthetic nano-polycrustalline diamond gemstone.Gems & Gemology, Vol. 48, 3, pp. 188-192.TechnologySynthetics
DS201312-0557
2013
Breeding, C.M.Luo, Y., Breeding, C.M.Fluorescence produced by optical defects in diamond: measurement, characterization, and challenges.Gems & Gemology, Vol. 49, 2, Summer pp. 82-97.TechnologyDiamond colour - spectra
DS201312-0813
2013
Breeding, C.M.Shigley, J.E., Breeding, C.M.Optical defects in diamond: a quick reference chart.Gems & Gemology, Vol. 49, 2, Summer pp. 107-111.Diamond colour - spectra
DS201412-0070
2014
Breeding, C.M.Breeding, C.M., Wang, WuyiA spectroscopic look at green and blue gem diamonds colored by artificial irradiation treatment.Geological Society of America Conference Vancouver Oct. 19-22, 1p. AbstractTechnologyIrradiated diamonds
DS201412-0965
2014
Breeding, C.M.Wang, Wuyi, D'Haenens-Johansson, U., Smit, K., Breeding, C.M., Stern, R.Carbon isotope analysis of CVD synthetic gem diamonds.Geological Society of America Conference Vancouver Oct. 19-22, 1p. AbstractTechnologySynthetics
DS201506-0295
2015
Breeding, C.M.Shigley, J.E., Breeding, C.M.Visible absorption spectra of colored diamonds.Gems & Gemology, Vol. 51, 1, pp. 41-43.TechnologyColoured diamonds
DS201512-1968
2015
Breeding, C.M.Shor, R., Weldon, R., Janse, A.J.A., Breeding, C.M., Shirey, S.B.Diamonds from the Letseng mine. Explores the history, geology, and current production of this unique source of large diamonds. Letseng La TeraeGems & Gemology, Vol. 51, 3, pp. 280-299.Africa, LesothoDeposit - Letseng
DS201606-1082
2016
Breeding, C.M.Eaton-Magana, S., Breeding, C.M.An introduction to photoluminescence spectroscopy for diamond and its application in gemology.Gems & Gemology, Vol. 52, 1, pp. 2-17.TechnologyIdentification of treated and synthetic diamonds.

Abstract: Photoluminescence (PL) spectroscopy is frequently mentioned in the gemological literature, but its relevance to the wider trade audience is rarely discussed. Due to the possibility of an undisclosed treatment or a synthetic origin, all type II diamonds (both colorless and fancy-color) and colorless type IaB diamonds submitted to gemological laboratories should ideally be tested using PL spectroscopy. Although the proportion of samples that require this testing is small, the failure to properly identify treated and synthetic diamonds could destabilize the diamond industry. This article seeks to clarify the underlying physics and methodology of this important tool for gemologists.
DS201608-1393
2016
Breeding, C.M.Breeding, C.M.The art and science of diamond fluorescence: what it tells us about the growth history of natural and synthetic gem diamonds.GSA Annual Meeting, Abstract, 1p.TechnologyFluorescence

Abstract: Gem diamonds are highly valued for their color, or the absence of it. However, the myriad of colors and patterns that are revealed when a diamond is exposed to ultraviolet light are often more impressive than the stones themselves. High energy (i.e., ultra-shortwave <230 nm) UV light from the DiamondView instrument excites fluorescence from natural and synthetic diamonds that not only provides a tremendous amount of information about defect incorporation during growth, but also stunningly artistic designs. Fluorescence patterns reveal details about the original morphology of a diamond even after all of the natural surfaces are removed. In addition, concentrations of luminescent centers along structurally controlled planes in a natural diamond lattice provide information about the original distribution of impurities and other defects and the thermal and deformational history of diamonds as they spend millions (or billions) of years in the Earth’s mantle and then are rapidly erupted in a kimberlite magma. Likewise, the distribution of nitrogen, boron, and nickel-related luminescence in synthetic diamonds give clues to the temperature, pressure, and catalytic conditions under which they were grown in a laboratory. Evaluation of the fluorescence patterns from diamonds helps the scientist better understand the incorporation and migration of atomic level defects in the diamond structure while allowing the artist to appreciate some of the most unusual and amazing patterns that nature produces.
DS201609-1742
2016
Breeding, C.M.Shigley, J.E., Shor, R., Padua, P., Breeding, C.M., Shirey, S.B., Ashbury, D.Mining diamonds in the Canadian Arctic: the Diavik mine.Gems & Gemology, Vol. 52, no. 2, Summer, pp. 104-131.Canada, Northwest TerritoriesDeposit - Diavik
DS201712-2684
2017
Breeding, C.M.Eaton-Magana, S., Shigley, J.E., Breeding, C.M.Observations on HPHT-grown synthetic diamonds: a review.Gems & Gemology, Vol. 53, 3, pp. 262-285.Technologysynthetics

Abstract: his article presents statistical data and distinctive features for several thousand HPHT-grown synthetic diamonds examined by GIA from 2007 through 2016. This study, the first comprehensive summary published on such a large number and wide variety of samples, describes the reliable means of identifying them, with a focus on material currently marketed for jewelry use. The color of HPHT synthetic diamonds analyzed by GIA has shifted noticeably during this time—in the early years, orange-yellow, yellow, and yellow-orange samples comprised the overwhelming majority, while colorless and blue samples are much more prevalent today. HPHT synthetics are making inroads into the large diamond market, with cut stones larger than 10 carats, as well as the colorless melee market, where small HPHT synthetics are being mass-produced in China. HPHT synthetics can be identified by their distinctive fluorescence patterns using the DiamondView luminescence imaging instrument, the lack of “strain” (anomalous birefringence) when viewed through crossed polarizers, and to a lesser extent by the detection of various features in photoluminescence (PL) spectroscopy. This material may also display magnetism and a short-wave fluorescence and phosphorescence reaction that are inconsistent with similarly colored natural diamonds.
DS201806-1214
2018
Breeding, C.M.Breeding, C.M., Eaton-Magana, S., Shigley, J.E.Natural color green diamonds: a beautiful conundrum.Gems& Gemology, Vol. 54, 1, spring pp. 2-27.South America, Brazil, Venezuela, Guyanadiamonds - green review

Abstract: Among fancy-color diamonds, natural-color green stones with saturated hues are some of the rarest and most sought after. These diamonds are colored either by simple structural defects produced by radiation exposure or by more complex defects involving nitrogen, hydrogen, or nickel impurities. Most of the world’s current production of fine natural green diamonds comes from South America or Africa. Laboratory irradiation treatments have been used commercially since the late 1940s to create green color in diamond and closely mimic the effects of natural radiation exposure, causing tremendous difficulty in gemological identification. Compounding that problem is a distinct paucity of published information on these diamonds due to their rarity. Four different coloring mechanisms—absorption by GR1 defects due to radiation damage, green luminescence from H3 defects, and absorptions caused by hydrogen- and nickel-related defects—can be identified in green diamonds. Careful microscopic observation, gemological testing, and spectroscopy performed at GIA over the last decade allows an unprecedented characterization of these beautiful natural stones. By leveraging GIA’s vast database of diamond information, we have compiled data representative of tens of thousands of samples to offer a look at natural green diamonds that has never before been possible.
DS201809-2017
2018
Breeding, C.M.Eaton-Magana, S., Breeding, C.M., Shigley, J.E.Natural color blue, gray, and violet diamonds: allure of the deep.Gems & Gemology, Vol. 54, 2, pp. 112-131.Africa, South Africa, Australiadiamond - colour

Abstract: Natural-color blue diamonds are among the rarest and most valuable gemstones. Gray and violet diamonds are also included here, as these diamonds can coexist on a color continuum with blue diamonds. More so than most other fancy colors, many diamonds in this color range are sourced from specific locations-the Cullinan mine in South Africa and the Argyle mine in Australia. Although blue color is often associated with boron impurities, the color of diamonds in this range (including gray and violet) also originates from simple structural defects produced by radiation exposure or from more complex defects involving hydrogen. These different mechanisms can be characterized by absorption and luminescence spectroscopy. A fourth mechanism-micro-inclusions of grayish clouds or tiny graphite particles in gray diamonds-can be distinguished through microscopy. In this article, we summarize prior research as well as collected data such as color and carat weight on more than 15,000 naturally colored blue/gray/violet diamonds from the GIA database (along with an analysis of spectroscopic data on a subset of 500 randomly selected samples) to provide an unprecedented description of these beautiful gemstones.
DS201901-0009
2018
Breeding, C.M.Breeding, C.M.Colored diamonds: the rarity and beauty of imperfection.Gems & Gemology, Sixth International Gemological Symposium Vol. 54, 3, 1p. Abstract p. 275.Globaldiamond color

Abstract: Diamond is often romanticized as a symbol of purity and perfection, with values that exceed all other gemstones. However, even the most flawless and colorless natural diamonds have atomic-level imperfections. Somewhat ironically, the rarest and most valuable gem diamonds are those that contain abundant impurities or certain atomic defects that produce beautiful fancy colors such as red, blue, or green—stones that can sell for millions of dollars per carat. Atomic defects can consist of impurities such as nitrogen or boron that substitute for carbon atoms in the diamond atomic structure (resulting in classifications such as type Ia, type Ib, type IIa, and type IIb) or missing or misaligned carbon atoms. Some defects are created during diamond growth, while others are generated over millions to billions of years as the diamond sits deep in the earth at high temperatures and pressures. Defects may be created when the diamond is rapidly transported to the earth’s surface or by interaction with radioactive fluids very near the earth’s surface. Each defect selectively absorbs different wavelengths of light to produce eye-visible colors. Absorptions from these color-producing defects (or color centers) are detected and identified using the gemological spectroscope or more sensitive absorption spectrometers such as Fouriertransform infrared (FTIR) or ultraviolet/visible/near-infrared (UV-Vis-NIR; figure 1). Some defects not only absorb light but also produce their own luminescence, called fluorescence. For example, the same defect that produces “cape” yellow diamonds also generates blue fluorescence when exposed to ultraviolet light. In some cases, the fluorescence generated by defects can be strong enough to affect the color of gem diamonds. With the exception of most natural white and black diamonds, where the color is a product of inclusions, colored diamonds owe their hues to either a single type of defect or a combination of several color centers. More than one type of defect can produce a particular color, however. Table 1 provides a list of the most common causes of color in diamond. Subtle differences in atomic defects can drastically affect a diamond’s color. For example, isolated atoms of nitrogen impurities usually produce strong yellow color (“canary” yellow diamonds). If those individual nitrogen atoms occur together in pairs, no color is generated and the diamond is colorless. If instead the individual nitrogen atoms occur adjacent to missing carbon atoms (vacancies), the color tends to be pink to red. Rearrangement of diamond defects is the foundation of using treatments to change the color of diamond. Identification of treatments and separation of natural and synthetic diamond requires a thorough understanding of the atomic-level imperfections that give rise to diamond color and value.
DS201903-0505
2018
Breeding, C.M.Eaton-Magana, S., Ardon, T., Smit, K.V., Breeding, C.M., Shigley, J.E.Natural color pink, purple, red and brown diamonds: band of many colors.Gems & Gemology, Vol. 54, 4, pp. 352-377.Global, Australiadiamond colour

Abstract: Diamond is one of Earth’s most extraordinary materials. It represents the pinnacle for several material and physical properties. As a gem, however, it is the near-perfect examples—diamonds attaining the D-Flawless distinction—and those with imperfections resulting in a vibrant or surprising color that create the most enduring impressions. Fancy-color natural diamonds are among the most highly valued gemstones due to their attractiveness and great rarity. The 18.96 ct Winston Pink Legacy, with a color grade of Fancy Vivid pink, recently made history by selling at over $50 million, its $2.6 million per carat price an all-time high for a pink diamond (Christie’s, 2018).
DS202001-0009
2019
Breeding, C.M.Eaton-Magana, S., Ardon, T., Breeding, C.M., Shigley, J.E.Natural color fancy white and fancy black diamonds: where color and clarity converge.Gems & Gemology, Vol. 55, 3, pp. 320-336.Globalreview

Abstract: Natural Fancy white and Fancy black diamonds are not routinely submitted to GIA for grading (fewer than 2,000 since 2008). These fancy-color diamonds are distinctive since the causes of color generally are not atomic-scale defects, but nanometer- to micrometer-sized inclusions that reduce the diamond’s transparency by scattering or absorbing light (some exceptions exist among Fancy black diamonds). To clarify, Fancy white diamonds are those rare stones colored by inclusions that give a “whitish” appearance, and are distinct from “colorless” diamonds on the D-to-Z scale. These two colors, often thought of as opposites in the color world, are grouped here as outliers within the colored diamond world. Both can be colored by inclusions so numerous the stone would fall below the I3 grade on the clarity scale, demonstrating that inclusions, often perceived as a negative quality factor, can create a distinctive appearance. Among the Fancy white diamonds examined for this study, the vast majority (82%) were type IaB, making them a rare subset of a rare diamond type. Based on prior geological research, these are surmised to be mostly sublithospheric in origin (i.e., forming more than 250 km below the earth’s surface). The Fancy white diamonds generally have a different chemistry from D-to-Z type IaB diamonds, with greater quantities of several hydrogen- and nickel-related defects. Among Fancy black diamonds, the major causes of color are either micrometer-sized dark crystal inclusions, nanometer-sized inclusions clustered into clouds, or a combination of the two. For these two colors of diamond, we summarize their gemological properties along with the absorption and luminescence spectra of a representative subset of diamonds from each color, examining how they deviate from the standard grading methodology. Because of their rarity, there has been very little systematic study of either of these color categories, and never a sample set of this quantity, which includes data for ~500 Fancy white and ~1,200 Fancy black diamonds.
DS202002-0199
2020
Breeding, C.M.Lai, M.Y., Breeding, C.M., Stachel, T., Stern, R.A.Spectroscopic features of natural and HPHT treated yellow diamonds. EkatiDiamonds & Related Materials, Vol. 101, 107642, 8p. PdfCanada, Northwest Territoriesdeposit - Ekati

Abstract: High pressure high temperature (HPHT) treatment has long been applied in the gem trade for changing the body colour of diamonds. The identification of HPHT-treated diamonds is a field of on-going research in gemological laboratories, as different parameters of treatment will result in either the creation or the destruction of a variety of lattice defects in diamonds. Some features that exist in treated diamonds can also be found in natural diamonds, and consequently must not be employed for the separation of treated and natural diamonds. In this research, we investigated the properties of 11 natural yellow diamonds (directly obtained from the Ekati Diamond Mine to ensure that they are untreated) before and after HPHT treatment, conducted at a temperature of 2100 °C and a pressure of 6 GPa for 10 min. We report spectroscopic data and fluorescence characteristics, collected using PL mapping, FTIR mapping and fluorescence imaging showing the distribution of lattice defects and internal growth structures. PL mapping indicates SiV defects exist in one of the nitrogen-rich natural diamonds prior to treatment. Silicon-related defects can also be created by HPHT treatment, and they seem to show a relationship with pre-existing NV? centres. SIMS analysis was conducted to confirm the presence of silicon in these diamonds. The increase in the hydrogen-related infrared absorption peak at 3107 cm?1 (VN3H) is very strong in some diamonds that do not form B-centres during treatment. NVH was observed in our HPHT-treated natural diamonds, so it is possible that this strong increase in VN3H suppresses the aggregation of A- to B-centres as the newly formed A-centres were captured by NVH lattice defects to form VN3H. HPHT-altered and HPHT-induced platelet peaks are different from their natural counterparts in peak width and shape. Strong green fluorescence over a large area of a diamond, which is linked to relatively high concentration of H3 centres, was produced after HPHT treatment. We are confident that the unusual platelet peaks and strong emission of H3 centres are reliable indicators for HPHT-treated diamonds as they are not observed in untreated natural diamonds.
DS202003-0344
2019
Breeding, C.M.Katsuke, Y., Sun, Z., Breeding, C.M., Dutrow, B.L.Geographic origin of Paraiba tourmaline.Gems & Gemology, Vol. 55, 4, pp. 648-659.South America, Braziltourmaline

Abstract: Vivid blue to green copper-bearing tourmalines, known as Paraíba tourmalines, are recovered from deposits in Brazil, Nigeria, and Mozambique. These tourmalines are sought after for their intense colors. Prices are based, in part, on the geographic origin of a stone, and determining provenance is thus an important aspect for Paraíba tourmaline. However, their geographic origin cannot be established by standard gemological testing and/or qualitative chemical analyses. GIA has established sophisticated criteria requiring quantitative chemical analyses to determine geographic origin for these tourmalines. These criteria were based on several hundred samples from known sources spanning the three countries. Highly accurate and precise quantitative elemental concentrations for Cu, Zn, Ga, Sr, Sn, and Pb are acquired with laser ablationinductively coupled plasmamass spectrometry (LA-ICP-MS). These data can then be plotted as a function of elemental concentration for accurate geographic origin determination.
DS202003-0347
2020
Breeding, C.M.Lai, M.Y., Stachel, T., Breeding, C.M., Stern, R.A.Yellow diamonds with colourless cores - evidence for episodic diamond growth beneath Chidliak and Ekati mine, Canada.Mineralogy and Petrology, in press available 13p. PdfCanada, Northwest Territoriesdeposit - Chidliak, Ekati

Abstract: Yellow diamonds from the CH-7 (Chidliak) and the Misery (Ekati Mine) kimberlites in northern Canada are characterised for their nitrogen characteristics, visible light absorption, internal growth textures, and carbon isotope compositions. The diamonds are generally nitrogen-rich, with median N contents of 1230 (CH-7) and 1030 at.ppm (Misery). Normally a rare feature in natural diamonds, single substitutional nitrogen (C centres) and related features are detected in infrared absorption spectra of 64% of the studied diamonds from CH-7 and 87% from Misery and are considered as the major factor responsible for their yellow colouration. Episodically grown diamonds, characterised by colourless cores containing some nitrogen in the fully aggregated form (B centres) and yellow outer layers containing C centres, occur at both localities. Carbon isotope compositions and N contents also are significantly different in such core and rim zones, documenting growth during at least two temporally distinct events and involving different diamond forming fluids. Based on their nitrogen characteristics, both the yellow diamonds and yellow rims must have crystallized in close temporal proximity (<<1 Ma) to kimberlite activity at CH-7 and Misery.
DS202006-0918
2020
Breeding, C.M.Eaton-Magana. S., McElhenny, G., Breeding, C.M., Ardon, T.Comparison of gemological and spectroscopic features in type IIa and Ia natural pink diamonds.Diamonds & Related Materials, Vol. 105, 13p. PdfMantlenitrogen

Abstract: The majority of natural pink diamonds have a color origin due to absorption from a broad 550?nm band that has been associated with plastic deformation. One consistent feature in the photoluminescence spectra of these pink diamonds is a wide emission band extending from ~600 to 750?nm, with a series of smaller oscillations overlaid on the larger emission band. This "pink emission band" is seen in diamonds colored by the 550?nm absorption band; the absorption band often, but not always, shows similar oscillations at ~600?nm (called the 609?nm system by previous researchers). This emission band served as a proxy for the 550?nm absorption band as we performed spatial mapping to chronicle the differences between the uniform coloration in type IIa pink diamonds and the pronounced banding in type Ia pink diamonds. We also used Raman spectroscopy to identify the internal crystal inclusions present in type IIa pink diamonds and determined that the majority have a sub-lithospheric origin.
DS202012-2208
2020
Breeding, C.M.Breeding, C.M., Eaton-Magana, S., Shigley, J.E.Naturallly colored yellow and orange gem diamonds: the nitrogen factor.Gems & Gemology, Vol. 56. 2. summer pp. 194-219. pdfGlobalnitrogen

Abstract: Natural yellow gem diamonds are the most common of the fancy-color diamonds, while orange diamonds are among the rarest when they have unmodified hues. Both categories owe their coloration to atomic-level lattice defects associated with nitrogen impurities in the diamond structure. Four major groups of defects are responsible for the color in nearly all yellow and orange diamonds: cape defects (N3 and associated absorptions), isolated nitrogen defects, the 480 nm visible absorption band, and H3 defects. Nitrogen-bearing diamonds are thought to incorporate isolated nitrogen during growth by substitution for carbon, meaning that natural diamonds start out with yellow to orange color. However, only the very rare type Ib diamonds maintain that original color. With time at high temperatures deep in the earth, the nitrogen atoms in most diamonds aggregate, resulting in either near-colorless stones or yellow diamonds colored by cape defects. Yellow and orange diamonds can be grown in a laboratory or created by color treatments, so a thorough understanding of the defects responsible for color in the natural stones is critical for identification. Yellow diamonds serve as the best ambassador to the colored diamond world due to their abundance and may be the only colored diamond many people will ever see in a jewelry store.
DS202102-0208
2020
Breeding, C.M.McElhenny, G., Turner, M., Breeding, C.M.Corundum inclusions in gem diamond.Gems & Gemology , Vol. 56, 1, pp. 129-131.Technologydiamond inclusions

Abstract: Inclusions can tell us a great deal about a diamond’s formation history. Inclusions such as olivine, garnet, and chromite are more common, while others such as kyanite, zircon, and corundum (Al2O3) can be quite rare. Regardless of their rarity, diamond inclusions are often quite fascinating as they trap a small bit of the deep earth that cannot otherwise be sampled.
DS202103-0377
2020
Breeding, C.M.Eaton-Magana, S., Ardon, T., Breeding, C.M., Shigley, J.E.Natural color D-to-Z diamonds: a crystal clear perspective.Gems & Gemology, Vol. 56, 3, pp. 318-335. pdfGlobaldiamond - colour

Abstract: Colorless to light yellow or brown diamonds with a “D-to-Z” color grade make up the overwhelming majority of the world’s gem diamond trade. Besides clarity features (such as inclusions) and fluorescence observations, however, comparatively little has been explored and published regarding the distinguishing characteristics of these diamonds. The vast majority are type Ia, with infrared spectra showing very high concentrations of nitrogen aggregates. This population of diamonds could not have been subjected to HPHT decolorizing treatment or been laboratory grown, and thus they have been spectroscopically scrutinized in much less detail than the far more rare natural diamonds of types IIa, IIb, and IaB, which need to be investigated as potentially color-treated or synthetic. This study examines a large sample set comprising the full complement of D-to-Z diamonds submitted to GIA laboratories during a significant portion of 2017. The data were evaluated on the basis of diamond type properties, as well as distribution among various grading quality factors, to provide an unprecedented glimpse into the role of these diamond types and differences in their geologic conditions of formation.
DS202110-1626
2021
Breeding, C.M.Luo, Y., Nelson, D., Ardon, T., Breeding, C.M.Measurement and characterization of the effects of blue fluorescence on diamond appearance. Gems & Gemology, Vol. 57, 2, summer pp. 102-123. gia.edu/gems-gemologyGlobalfluorescence
DS201804-0675
2018
Breeding, M.Breeding, M.Diamond defects, diamond colour treatment, and its identification.4th International Diamond School: Diamonds, Geology, Gemology and Exploration Bressanone Italy Jan. 29-Feb. 2nd., pp. 11-13. abstractTechnologydiamond -color centers
DS202104-0611
2021
Breev, I.D.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.
DS201901-0095
2018
Breeze, B.G.Zhao, J., Breeze, B.G., Green, B.L., Diggle, P.L., Newton, M.E.Fluorescence, phosphoresence, thermoluminesence, and charge tranfer in synthetic diamond.Gems & Gemology, Sixth International Gemological Symposium Vol. 54, 3, 1p. Abstract p. 266.GlobalFluoresence

Abstract: Photoluminescence (PL) and phosphorescence underpin many of the discrimination techniques used to separate natural from synthetic diamond. PL is at the heart of many new quantum technologies based on color centers in lab-grown diamonds. In HPHT synthetic diamond, the phosphorescence observed is explained in terms of donor-acceptor pair recombination. The thermal activation of electrons to neutral boron acceptors shows that boron plays a key role in the phosphorescence process. However, there are a number of things we struggle to explain. For example, the phosphorescence peak positions are not fully explained, and there is no conclusive link between the emission and charge transfer involving the substitutional nitrogen donor. Secondly, the origin of the phosphorescence observed in some synthetic diamond samples grown by the CVD process is unclear. Although we now have evidence for unintentional boron impurity incorporation at stop-start growth boundaries in some CVD syn- 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.
DS1991-0168
1991
Brehaut, H.Brehaut, H.It isn't easy being green - or becoming -greenCrs Perspectives, No. 37, October pp. 6-11CanadaEnvironmental, Laws
DS1991-0169
1991
Brehaut, H.Brehaut, H.Environmental management from a corporate perspectiveThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin) , Special Feature on environment, Vol. 84, No. 952, August pp. 63-66CanadaLegal -environment, Company -Placer Dome
DS201608-1419
2016
Brehme, I.Maia, M., Sichel, S., Briais, A., Brunelli, D., Ligi, M., Ferreira, N., Campos, T., Mougel, B., Brehme, I., Hemond, C., Motoki, A., Moura, D., Scalabrin, C., Pessanha, I., Alves, E., Ayres, A., Oliveira, P.Extreme mantle uplift and exhumation along a transpressive transform fault.Nature Geoscience, Vol. 9, 8, pp. 619-623.MantleRidges

Abstract: Mantle exhumation at slow-spreading ridges is favoured by extensional tectonics through low-angle detachment faults1, 2, 3, 4, and, along transforms, by transtension due to changes in ridge/transform geometry5, 6. Less common, exhumation by compressive stresses has been proposed for the large-offset transforms of the equatorial Atlantic7, 8. Here we show, using high-resolution bathymetry, seismic and gravity data, that the northern transform fault of the St Paul system has been controlled by compressive deformation since ~10?million years ago. The long-lived transpression resulted from ridge overlap due to the propagation of the northern Mid-Atlantic Ridge segment into the transform domain, which induced the migration and segmentation of the transform fault creating restraining stepovers. An anticlockwise change in plate motion at ~11?million years ago5 initially favoured extension in the left-stepping transform, triggering the formation of a transverse ridge, later uplifted through transpression, forming the St Peter and St Paul islets. Enhanced melt supply at the ridge axis due to the nearby Sierra Leone thermo chemical anomaly9 is responsible for the robust response of the northern Mid-Atlantic Ridge segment to the kinematic change. The long-lived process at the origin of the compressive stresses is directly linked to the nature of the underlying mantle and not to a change in the far-field stress regime.
DS201903-0542
2019
Breikreuz, C.Schmiedel, T., Gailland, O., Haug, O.T., Dumazer, G., Breikreuz, C.Coulomb failure of Earth's brittle crust controls growth, emplacement and shapes of igneous sills, saucer-shaped sills and laccoliths.Earth and Planetary Science Letters, Vol. 510, pp. 161-172.MantleMagmatism

Abstract: Tabular intrusions are common features in the Earth's brittle crust. They exhibit a broad variety of shapes, ranging from thin sheet intrusions (sills, saucer-shaped sills, cone sheets), to more massive intrusions (domed and punched laccoliths, stocks). Such a diversity of intrusion shapes reflects different emplacement mechanisms caused by contrasting host rock and magma rheologies. Most current models of tabular intrusion emplacement assume that the host rock behaves purely elastically, whereas numerous observations show that shear failure plays a major role. In this study, we investigate the effects of the host rock's Coulomb properties on magma emplacement by integrating (1) laboratory models using dry Coulomb granular model hosts of variable strength (cohesion) and (2) limit analysis numerical models. Our results show that both sheet and massive tabular intrusions initiate as a sill, which triggers shear failure of its overburden along an inclined shear damage zone at a critical sill radius, which depends on the emplacement depth and the overburden's cohesion. Two scenarios are then possible: (1) if the cohesion of the overburden is significant, opening of a planar fracture along the precursory weakened shear damage zones to accommodate magma flow, leads to the formation of inclined sheets, or (2) if the cohesion of the overburden is negligible, the sill inflates and lifts up the overburden, which is dissected by several faults that control the growth of a massive intrusion. Finally, we derive a theoretical scaling that predicts the thickness-to-radius aspect ratios of the laboratory sheet intrusions. This theoretical prediction shows how sheet intrusion morphologies are controlled by a mechanical equilibrium between the flowing viscous magma and Coulomb shear failure of the overburden. Our study suggests that the emplacement of sheet and massive tabular intrusions are parts of the same mechanical regime, in which the Coulomb behavior of the Earth's brittle crust plays an essential role.
DS1993-0063
1993
Breitkreuz, C.Bahlburg, H., Breitkreuz, C.Differential response of a Devonian Carboniferous platform deeper basin systen to sea-level change and tectonics N. Chilean AndesBasin Research, Vol. 5, No. 1, March pp. 21-40ChileBasin, Platform successions
DS200612-0170
2006
Breivik, A.J.Breivik, A.J., Mjelde, R., Faleide, Jl., Murai, Y.Rates of continental breakup magmatism and seafloor spreading in the Norway Basin Iceland plume interaction.Journal of Geophysical Research,, Vol. 111, B7, B7102,Europe, Iceland, NorwayMagmatism
DS200512-0112
2005
Bremen, J.Bremen, J., Lawrence, A.Taking it to the bank - making your mining project bankable.Engineering and Mining Journal, Sept. pp. 80-83.GlobalEconomics - feasibility studies
DS1920-0409
1928
Bremer, B.Twenhofel, W.H., Bremer, B.An Extension of the Rose Dome Intrusives, KansasAmerican Association of Petroleum Geologists, Vol. 12, No. 7, PP. 757-762.KansasKimberlite, Central States, Wilson, Woodson
DS1970-0593
1972
Bremme.Rogers, J., Summerhayes, C.P., Dingle, R.V., Birch, G.F., Bremme.Distribution of Minerals on the Seabed Around South Africa And Problems in Their Exploration and Eventual Exploitation.Eng. Com. Oceanogr. Res. Symposium Held Stellenbosch, S71, 8P.Southwest Africa, NamibiaDiamonds, Mining Methods
DS1986-0106
1986
Bremmer, J.M.Bremmer, J.M.Diamonds, 1986Sagittarius, Vol. 1, No. 2, pp. 4-7South AfricaPopular geology
DS1970-0639
1973
Bremner, J.M.Bremner, J.M.The Texture and Composition of Surficial Sediments between Sylvia Hill 25 S and Walvis Bay 23 S.Tech. Report Mar. Geol. Prog. Geological Survey of South Africa And University, Vol. 5, PP. 89-93.Southwest Africa, NamibiaGeomorphology
DS1989-0170
1989
Bremner, J.M.Bremner, J.M.Diamond concession areas 3A and 3B, Port NollothDepartment of Mineral and Energy Affairs, Annual technical report of Geol., pp. 172-173South AfricaProspecting activities, Diamond concessions
DS1989-0171
1989
Brenan, J.M.Brenan, J.M., Watson, E.B.Partioning of rare earth elements (REE)'s Berylium, Barium, Calsium and Strontium between clino-pyroxene, olivine and carbonate melt at mantle conditionsGeological Society of America (GSA) Annual Meeting Abstracts, Vol. 21, No. 6, p. A105. AbstractGlobalCarbonatite, rare earth elements (REE).
DS1991-0170
1991
Brenan, J.M.Brenan, J.M., Watson, E.B.Partitioning of trace elements between carbonate melt and clinopyroxene and olivine at mantle P-T conditionsGeochimica et Cosmochimica Acta, Vol. 53, pp. 2203-2214GlobalGeochemistry, Carbonate rich melts, lherzolites
DS1995-0206
1995
Brenan, J.M.Brenan, J.M., Shaw, H.F., Phinney, D.L.Mineral aequeous fluid partitioning of trace elements at 900C 2.0 GPa:constraints on trace elements -mantleGeochimica et Cosmochimica Acta, Vol. 59, No. 16, August 1, pp. 3331-50MantleGeochemistry
DS1995-0207
1995
Brenan, J.M.Brenan, J.M., Shaw, H.F., Ryerson, PhinneyMineral aequeous fluid partitioning of trace elements at 900 and 2.0 GPa:constraints - chemistry....Geochimica et Cosmochimica Acta, Vol. 59, No. 16, pp. 3331-50.MantleMineral chemistry, Deep crustal fluids
DS1998-0163
1998
Brenan, J.M.Brenan, J.M., Neroda, et al.Behaviour of boron, beryillium and lithium during melting andcrystallization: constraints from mineral melt partitioning experiments.Geochimica et Cosmochimica Acta, Vol. 62, No. 12, pp. 2129-41.MantleMelting
DS1999-0093
1999
Brenan, J.M.Brenan, J.M., Ryerson, F.J., Shaw, H.F.The role of aqueous fluids in slab to mantle transfer of boron, berylliumand lithium during subduction....Geochimica et Cosmochimica Acta, Vol. 62, No. 19-10, Oct. 1, pp. 3337-49.MantleSubduction, Fluidization
DS2003-1237
2003
Brenan, J.M.Schulze, D.J., Harte, B., Valley, J.W., Brenan, J.M., DeR. Channer, D.M.Extreme crustal oxygen isotope signatures preserved in coesite diamondNature, No. 6935, May 1, p. 68-69.GlobalGeochronology
DS200412-1767
2003
Brenan, J.M.Schulze, D.J., Harte, B., Valley, J.W., Brenan, J.M., DeR Channer, D.M.Extreme crustal oxygen isotope signatures preserved in coesite diamond.Nature, No. 6935, May 1, p. 68-69.TechnologyGeochronology
DS201112-0133
2011
Brenan, J.M.Caciagli, N., Brenan, J.M., McDonough, W.F., Phinney, D.Mineral fluid partitioning of lithium and implications for slab-mantle interaction.Chemical Geology, Vol. 280, 3-4, pp. 384-398.MantleGeochemistry
DS1950-0260
1956
Brendler, W.Brendler, W.Gruene Diamanten aus SuedafrikaAufschluss, Vol. 7, PP. 2-4.Southwest Africa, Namibia, South AfricaDiamond, Morphology, Colour
DS200612-0097
2006
Brenizer, J.Bass, J.D., Sanchez-Valle, C., Lakshtanov, D.L., Brenizer, J., Wang, J., Matas, J.Elastic properties of high pressure phases and implications for the temperature and mineralogy of Earth's lower mantle.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.MantleGeothermometry
DS1995-0208
1995
Brenker, F.Brenker, F., Muller, W.F., Brey, G.Microstructural minerals from the garnet lherzolite body Alpe Arami -mantle conditions and uplift history.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 66-68.GlobalLherzolites, Mantle
DS200712-1170
2007
Brenker, F.Wirth, R., Vollmer, C., Brenker, F., Matsyuk, S., Kaminsky, F.Inclusions of nanocrystalline hydrous aluminum silicate 'phase egg' in superdeep diamonds from Juin a ( Mato Grosso State, Brazil).Earth and Planetary Science Letters, Vol. 259, 3-4, pp. 384-399.South America, Brazil, Mato GrossoDiamond - mineralogy
DS200712-1171
2007
Brenker, F.Wirth, R., Vollmer, C., Brenker, F., Matsyuk, S., Kaminsky, F.Inclusions of nanocrystalline hydrous aluminum silicate 'phase egg' in superdeep diamonds from Juin a ( Mato Grosso State, Brazil).Earth and Planetary Science Letters, Vol. 259, 3-4, pp. 384-399.South America, Brazil, Mato GrossoDiamond - mineralogy
DS201012-0073
2010
Brenker, F.Brenker, F.Trapped high density fluids in superdeep diamonds.International Mineralogical Association meeting August Budapest, AbstractTechnologyUHP
DS201412-0668
2014
Brenker, F.Pearson, D.G., Brenker, F., Nestola, F., McNeil, J., Nasdala, L., Hutchison, M., Mateev, S., Mather, K., Silversmit, G., Schmitz, S., Vekemans, B., Vinczw=e, L.A hydrous mantle transition zone indicated by ring woodite included within diamond.Goldschmidt Conference 2014, 1p. AbstractMantleDiamond inclusion
DS2000-0782
2000
Brenker, F. HartePrior, D.J., Wheeler, J., Brenker, F. Harte, MatthewsCrystal plasticity of natural garnet: new microstructural evidenceGeology, Vol. 28, No. 1, Nov. pp. 1003-6.MantleGarnets, xenoliths, kelphite, Microscopy
DS2002-0202
2002
Brenker, F.E.Brenker, F.E., Kaminsky, F., Joswig, W.Polytypes of CaSiO3 walstromite in diamonds from Juina: an indicator of retrograde reaction from CaSIO3 perovskite.18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.78. (poster)BrazilUHP mineralogy
DS2002-0203
2002
Brenker, F.E.Brenker, F.E., Stachel, T., Harris, J.W.Exhumation of lower mantle inclusions in diamond: ATEM investigation of retrograde phase transitions, reactionEarth and Planetary Science Letters, Vol.198,1-2,pp.1-9., Vol.198,1-2,pp.1-9.MantleMineralogy - diamond inclusions
DS2002-0204
2002
Brenker, F.E.Brenker, F.E., Stachel, T., Harris, J.W.Exhumation of lower mantle inclusions in diamond: ATEM investigation of retrograde phase transitions, reactionEarth and Planetary Science Letters, Vol.198,1-2,pp.1-9., Vol.198,1-2,pp.1-9.MantleMineralogy - diamond inclusions
DS2003-0156
2003
Brenker, F.E.Brenker, F.E., Meibom, A., Frei, R.On the formation of peridotite derived Os rich PGE alloysAmerican Mineralogist, Vol. 88, pp. 1731-40.MantleMagmatism - peridotites
DS2003-0157
2003
Brenker, F.E.Brenker, F.E., Stachel, T., Harris, J.W.TEM analysis of inclusions in diamonds from the lower mantle and transition zone8ikc, Www.venuewest.com/8ikc/program.htm, Session 3, POSTER abstractGuineaDiamonds - inclusions
DS200412-0204
2003
Brenker, F.E.Brenker, F.E., Meibom, A., Frei, R.On the formation of peridotite derived Os rich PGE alloys.American Mineralogist, Vol. 88, pp. 1731-40.MantleMagmatism - peridotites
DS200412-1406
2003
Brenker, F.E.Nasdala, L., Brenker, F.E., Glinnemann, J., Hofmeister, W., Gasparik, T., Harris, J.W., Stachel, T., Reese, I.Spectroscopic 2D tomography: residual pressure and strain around mineral inclusions in diamonds.European Journal of Mineralogy, Vol.15, 6, pp. 931-36.TechnologyTechnology - tomography inclusions
DS200512-0113
2005
Brenker, F.E.Brenker, F.E., Vincze, L., Velemans, Nasdala, Stachel, Vollmer, Kersten, Somogyi, Adams, Joswig, HarrisDetection of a Ca rich lithology in the Earth's deep ( >300km) convecting mantle.Earth and Planetary Science Letters, Vol. 236, 3-4, pp. 579-587.Africa, GuineaKankan, diamond inclusions, spectroscopy
DS200612-0171
2006
Brenker, F.E.Brenker, F.E., Vollmer, C., Vincze, L., Vekemans, B., Szymanski, A., Janssens, K., Szaloki, I., Nasdala, L., Joswig, W., Kaminsky, F.CO2 recycling to the deep convecting mantle.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.MantleConvection
DS200712-0106
2007
Brenker, F.E.Brenker, F.E., Vollmer, C., Vincze, L., Vekemans, B., Szymanski, Janssens, Szaloki, Nasdala, Joswig, KaminskyCarbonates from the lower part of transition zone or even the lower mantle.Earth and Planetary Science Letters, Vol. 260, 1-2, pp. 1-9.MantleCarbonates
DS200712-0107
2007
Brenker, F.E.Brenker, F.E., Vollmer, C., Vincze, L., Vekemans, B., Szymanski, Janssens, Szaloki, Nasdala, Joswig, KaminskyCarbonates from the lower part of transition zone or even the lower mantle.Earth and Planetary Science Letters, Vol. 260, 1-2, pp. 1-9.MantleCarbonates
DS200712-0108
2007
Brenker, F.E.Brenker, F.E., Vollmer, Vincze, Vekemans, Szymanski, Janssens, Szaloki, Nasdala, Joswig, KaminskyCarbonates from the lower part of transition zone or even the lower mantle.Earth and Planetary Science Letters, Vol. 260, 1-2, pp. 1-9.MantleCarbonates
DS201112-0961
2011
Brenker, F.E.Silversmit, G., Vekemans, B., Appel, K., Schmitz, S., Schoonjans, T., Brenker, F.E., Kaminsky, F., Vincze, L.Three dimensional Fe speciation of an inclusion cloud within an ultradeep diamond by confocal u-x-ray absortion near edge structure: evidence for late stageAnalytical Chemistry, Vol. 83, pp. 6294-6299.South America, Brazil, Mato GrossoJuina, Rio Soriso, diamond overprint
DS201412-0669
2014
Brenker, F.E.Pearson, D.G., Brenker, F.E., Nestola, F., McNeill, J., Nasdala, L., Hutchinson, M.T., Mateev, S., Mather, K., Silversmit, G., Schmitz, S., Vekemans, B., Vincze, L.Hydrous mantle transition zone indicated by ring woodite included in diamond.Nature, Vol. 507, March 13, pp. 221-224.Mantle, South America, Brazil, Mato GrossoDiamond inclusion - water storage capacity, magmatism
DS201611-2095
2016
Brenker, F.E.Anzolini, C., Angel, R.J., Merlini, M., Derzsi, M., Tokar, K., Milani, S., Krebs, M.Y., Brenker, F.E., Nestola, F., Harris, J.W.Depth of formation of CaSi)3 - walstromite included in super -deep diamonds.Lithos, in press available 43p.South America, Brazil, Mato GrossoDeposit - Juina

Abstract: "Super-deep" diamonds are thought to crystallize between 300 and 800 km depth because some of the inclusions trapped within them are considered to be the products of retrograde transformation from lower mantle or transition zone precursors. In particular, single inclusion CaSiO3-walstromite is believed to derive from CaSiO3-perovskite, although its real depth of origin has never been proven. Our aim is therefore to determine for the first time the pressure of formation of the diamond-CaSiO3-walstromite pair by “single-inclusion elastic barometry” and to determine whether CaSiO3-walstromite derives from CaSiO3-perovskite or not. We investigated several single phases and assemblages of Ca-silicate inclusions still trapped in a diamond coming from Juina (Brazil) by in-situ analyses (single-crystal X-ray diffraction and micro-Raman spectroscopy) and we obtained a minimum entrapment pressure of ~ 5.7 GPa (? 180 km) at 1500 K. However, the observed coexistence of CaSiO3-walstromite, larnite (?-Ca2SiO4) and CaSi2O5-titanite in one multiphase inclusion within the same diamond indicates that the sample investigated is sub-lithospheric with entrapment pressure between ~ 9.5 and ~ 11.5 GPa at 1500 K, based on experimentally-determined phase equilibria. In addition, thermodynamic calculations suggested that, within a diamond, single inclusions of CaSiO3-walstromite cannot derive from CaSiO3-perovskite, unless the diamond around the inclusion expands by ~ 30% in volume.
DS201611-2135
2016
Brenker, F.E.Rudloff-Grund, J., Brenker, F.E., Marquardt, K., Howell, D., Schrieber, A., O'Reilly, S.Y., Griffin, W.L., Kaminsky, F.V.Nitrogen nanoinclusions in milky diamonds from Juin a area, Mato Grosso State, Brazil.Lithos, in press available 34p.South America, Brazil, Mato GrossoDeposit - Juina
DS201802-0219
2018
Brenker, F.E.Anzolini, C., Prencipe, M., Alvaro, M., Romano, C., Vona, A., Lorenzon, S., Smith, E.M., Brenker, F.E., Nestola, F.Depth of formation of super deep diamonds: Raman barometry of CaSiO3 walstromite inclusions.American Mineralogist, Vol. 103, pp. 69-74.Mantlegeobarometry

Abstract: “Super-deep” diamonds are thought to have a sub-lithospheric origin (i.e., below ~300 km depth) because some of the mineral phases entrapped within them as inclusions are considered to be the products of retrograde transformation from lower-mantle or transition-zone precursors. CaSiO3-walstromite, the most abundant Ca-bearing mineral inclusion found in super-deep diamonds, is believed to derive from CaSiO3-perovskite, which is stable only below ~600 km depth, although its real depth of origin is controversial. The remnant pressure (Pinc) retained by an inclusion, combined with the thermoelastic parameters of the mineral inclusion and the diamond host, allows calculation of the entrapment pressure of the diamond-inclusion pair. Raman spectroscopy, together with X-ray diffraction, is the most commonly used method for measuring the Pinc without damaging the diamond host. In the present study we provide, for the first time, a calibration curve to determine the Pinc of a CaSiO3-walstromite inclusion by means of Raman spectroscopy without breaking the diamond. To do so, we performed high-pressure micro-Raman investigations on a CaSiO3-walstromite crystal under hydrostatic stress conditions within a diamond-anvil cell. We additionally calculated the Raman spectrum of CaSiO3-walstromite by ab initio methods both under hydrostatic and non-hydrostatic stress conditions to avoid misinterpretation of the results caused by the possible presence of deviatoric stresses causing anomalous shift of CaSiO3-walstromite Raman peaks. Last, we applied single-inclusion elastic barometry to estimate the minimum entrapment pressure of a CaSiO3-walstromite inclusion trapped in a natural diamond, which is ~9 GPa (~260 km) at 1800 K. These results suggest that the diamond investigated is certainly sub-lithospheric and endorse the hypothesis that the presence of CaSiO3-walstromite is a strong indication of super-deep origin.
DS201809-2001
2018
Brenker, F.E.Brenker, F.E., Koch, T.E., Prior, D.J., Lilly, K., Krot, A.N., Bizzarro, M., Frost, D.Fe rich Ferropericlase in super deep diamonds and the stability of high FeO wadsleyite. Implications on the composition and temperature of the Earth's transition zone.Goldschmidt Conference, 1p. AbstractMantlediamond inclusions

Abstract: The high amount of Fe-rich ferropericlase inclusions found in diamonds of a potential super-deep origin questions the bulk chemical model of the Earth [e.g., 1]. Although this might be due to a biased sampling of the lower mantle, it is worth to further address this discrepancy. A limiting factor of the Fe-content of the Earth´s deep mantle (TZ and lower mantle) is a correlation of the depths of the observed main mantle discontinuities with the (Fe,Mg)SiO4 phase diagram. In particular, the 520 kmdiscontinuity is related to the phase transformation of wadsleyite (assuming Fa10) to ringwoodite. The existing phase diagrams suggest a stability limit of wadsleyite ?Fa40 [e.g., 2,3], which limits the Fe-content of the Earth´s transition zone. Here we report on a discovery of Fe-rich wadsleyite grains (up to Fa56) in the high-pressure silicate melt droplets within Fe,Ni-metal in shock veins of the CB (Bencubbin-like) metal-rich carbonaceous chondrite QC 001 [4], which were identified using HR-EDX, nano-EBSD and TEM. Although the existence of such Fe-rich wadsleyite in shock veins may be due to the kinetic reasons, new theoretical and experimental studies of the stability of (Fe,Mg)SiO4 at high temperature (> 1800 K) are clearly needed. This may have significant impact on the temperature and chemical estimates of the Earth´s transition zone.
DS201908-1799
2019
Brenker, F.E.Nestola, F., Lorenzon, S., Nimis, P., Anzolini, C., Brenker, F.E.In-situ, ambien analysis of diamond-captured transition-zone and lower mantle minerals.www.minsocam.org/ MSA/Centennial/ MSA_Centennial _Symposium.html The next 100 years of mineral science, June 20-21, p. 21. AbstractMantlediamond inclusions

Abstract: Inclusions in diamonds can tell us much of the deep and inaccessible portions of our planet including its mineralogy and the deeper effects of plate tectonics. Recently, great attention has been given in particular to those inclusions which classify their diamond hosts as “super-deep” or “sublithospheric” diamonds, which comprise only ~ 1% of the entire world diamond population (Stachel and Harris 2008). Compared to lithospheric diamonds, which form between about 120 km and 250 km depth, super-deep diamonds are believed to have formed at depths as high as 800 km. But what is the actual depth of formation of superdeep diamonds? Do they come from the Transition Zone (410-660 km depth) and Lower Mantle (below 660 km depth) or some of them form in the Upper Mantle (down to 410 km depth)? Recent advances in X-ray crystallography and theoretical understanding of mineral elasticity now allow us to answer these questions by analyzing inclusions trapped within them. Among these we can mention: jeffbenite, (Mg,Fe)3Al2Si3O12 (Nestola et al. 2016; previously known as TAPP), breyite, CaSiO3 (Brenker et al. 2018; previously known as CaSiO3-walstromite, Joswig et al. 1999, Stachel et al. 2000), ringwoodite, (Mg,Fe)2SiO4 (Pearson et al. 2014), CaSi2O5 with titanite structure (Stachel et al. 2000, Brenker et al. 2005, 2007), CaSiO3 with perovskite structure (Nestola et al. 2018). Other inclusions are typically found in super-deep diamonds but, if taken alone, they cannot be unambiguously assigned to specific depth: ferropericlase, (Mg,Fe)O, which is the most common inclusion in super-deep diamonds (e.g. Brey et al. 2004, Harte 2010), majoritic garnet, Mg3(Mg,Fe,Al,Si)2Si3O12 (Moore and Gurney 1985, Stachel et al. 2005, Walter et al. 2011), low-Ni enstatite (i.e. enstatite with very low NiO content close to 0.02 wt%, considered to be retrogressed bridgmanite, as opposed to typical Upper Mantle enstatite with 0.1-0.2 % , is, Stachel et al. 2000) and larnite, Ca2SiO4 (e.g. Brenker et al. 2005). These 9 types of inclusions are not the only ones found in super-deep diamonds, but they certainly are the most representative and abundant ones. Here, we want to provide an overview on the real significance of such important inclusions as depth markers. In particular, we will discuss which inclusion types can definitively prove a Transition-Zone or Lower-Mantle origin of super-deep diamonds, giving mineralogy a new relevance for the understanding of the deepest reaches of our planet.
DS201912-2825
2020
Brenker, F.E.Shirey, S.B., Smit, K.V., Pearson, D.G., Walter, M.J., Aulbach, S., Brenker, F.E., Bureau, H., Burnham, A.D., Cartigny, P., Chacko, T., Frost, D.J., Hauri, E.H., Jacob, D.E., Jacobsen, S.D., Kohn, S.C., Luth, R.W., Mikhail, S., Navon, O., Nestola, F., NimDiamonds and the mantle geodynamics of carbon: deep mantle carbon and evolution from the diamond record.IN: Deep carbon: past to present, Orcutt, Daniel, Dasgupta eds., pp. 89-128.Mantlegeodynamics

Abstract: The science of studying diamond inclusions for understanding Earth history has developed significantly over the past decades, with new instrumentation and techniques applied to diamond sample archives revealing the stories contained within diamond inclusions. This chapter reviews what diamonds can tell us about the deep carbon cycle over the course of Earth’s history. It reviews how the geochemistry of diamonds and their inclusions inform us about the deep carbon cycle, the origin of the diamonds in Earth’s mantle, and the evolution of diamonds through time.
DS202001-0039
2020
Brenker, F.E.Shirey, S.B., Smit, K.V., Pearson, D.G., Walter, M.J., Aulbach, S., Brenker, F.E., Bureau, H., Burnham, A.D., Cartigny, P., Chacko, T., Frost, D.J., Hauri, E.H., Jacob, D.E., Jacobsen, S.D., Kohn, S.C., Luth, R.W., Mikhail, S., Navon, O., Nestola, F., NimDiamonds and mantle geodynamics of carbon: IN: Deep Carbon: past to present. Editors Orcutt, Danielle, Dasgupta, pp. 89-128.Mantlegeodynamics

Abstract: The science of studying diamond inclusions for understanding Earth history has developed significantly over the past decades, with new instrumentation and techniques applied to diamond sample archives revealing the stories contained within diamond inclusions. This chapter reviews what diamonds can tell us about the deep carbon cycle over the course of Earth’s history. It reviews how the geochemistry of diamonds and their inclusions inform us about the deep carbon cycle, the origin of the diamonds in Earth’s mantle, and the evolution of diamonds through time.
DS202004-0519
2020
Brenker, F.E.Howell, D., Stachel, T., Stern, R.A., Pearson, D.G., Nestola, F., Hardman, M.F., Harris, J.W., Jaques, A.L., Shirery, S.B., Cartigny, P., Smit, K.V., Aulbach, S., Brenker, F.E., Jacob, D.E., Thomassot, E., Walter, M.J., Navon, O.Deep carbon through time: Earth's diamond record and its implications for carbon cycling and fluid speciation in the mantle.(peridotite and eclogite used)Geochimica et Cosmochimica Acta, Vol. 275, pp. 99-122.Mantlecarbon

Abstract: Diamonds are unrivalled in their ability to record the mantle carbon cycle and mantle fO2 over a vast portion of Earth’s history. Diamonds’ inertness and antiquity means their carbon isotopic characteristics directly reflect their growth environment within the mantle as far back as ?3.5 Ga. This paper reports the results of a thorough secondary ion mass spectrometry (SIMS) carbon isotope and nitrogen concentration study, carried out on fragments of 144 diamond samples from various locations, from ?3.5 to 1.4 Ga for P [peridotitic]-type diamonds and 3.0 to 1.0 Ga for E [eclogitic]-type diamonds. The majority of the studied samples were from diamonds used to establish formation ages and thus provide a direct connection between the carbon isotope values, nitrogen contents and the formation ages. In total, 908 carbon isotope and nitrogen concentration measurements were obtained. The total ?¹³C data range from ?17.1 to ?1.9 ‰ (P = ?8.4 to ?1.9 ‰; E = ?17.1 to ?2.1‰) and N contents range from 0 to 3073 at. ppm (P = 0 to 3073 at. ppm; E = 1 to 2661 at. ppm). In general, there is no systematic variation with time in the mantle carbon isotope record since > 3 Ga. The mode in ?¹³C of peridotitic diamonds has been at ?5 (±2) ‰ since the earliest diamond growth ?3.5 Ga, and this mode is also observed in the eclogitic diamond record since ?3 Ga. The skewness of eclogitic diamonds’ ?¹³C distributions to more negative values, which the data establishes began around 3 Ga, is also consistent through time, with no global trends apparent. No isotopic and concentration trends were recorded within individual samples, indicating that, firstly, closed system fractionation trends are rare. This implies that diamonds typically grow in systems with high excess of carbon in the fluid (i.e. relative to the mass of the growing diamond). Any minerals included into diamond during the growth process are more likely to be isotopically reset at the time of diamond formation, meaning inclusion ages would be representative of the diamond growth event irrespective of whether they are syngenetic or protogenetic. Secondly, the lack of significant variation seen in the peridotitic diamonds studied is in keeping with modeling of Rayleigh isotopic fractionation in multicomponent systems (RIFMS) during isochemical diamond precipitation in harzburgitic mantle. The RIFMS model not only showed that in water-maximum fluids at constant depths along a geotherm, fractionation can only account for variations of <1‰, but also that the principal ?¹³C mode of ?5 ± 1‰ in the global harzburgitic diamond record occurs if the variation in fO2 is only 0.4 log units. Due to the wide age distribution of P-type diamonds, this leads to the conclusion that the speciation and oxygen fugacity of diamond forming fluids has been relatively consistent. The deep mantle has therefore generated fluids with near constant carbon speciation for 3.5 Ga.
DS202009-1613
2020
Brenker, F.E.Brenker, F.E., Nestola, F., Brenker, L., Peruzzo, L., Harris, J.W.Origin, properties and structure of breyite: the second most abundant mineral inclusion in super-deep diamonds. The American Mineralogist, in press available, 21p. PdfMantlebreyite
DS202102-0176
2021
Brenker, F.E.Brenker, F.E., Nestola, F., Brenker, L., Peruzo, L., Harris, J.WOrigin, properties, and structure of breyite: the second most abundant mineral inclusion in super-deep diamonds.The American Mineralogist, Vol. 106, pp. 38-43. pdfMantleperovskites, mineral inclusions

Abstract: Earth's lower mantle most likely mainly consists of ferropericlase, bridgmanite, and a CaSiO3- phase in the perovskite structure. If separately trapped in diamonds, these phases can be transported to Earth's surface without reacting with the surrounding mantle. Although all inclusions will remain chemically pristine, only ferropericlase will stay in its original crystal structure, whereas in almost all cases bridgmanite and CaSiO3-perovskite will transform to their lower-pressure polymorphs. In the case of perovskite structured CaSiO3, the new structure that is formed is closely related to that of walstromite. This mineral is now approved by the IMA commission on new minerals and named breyite. The crystal structure is triclinic (space group: P1) with lattice parameters a0 = 6.6970(4) Å, b0 = 9.2986(7) Å, c0 = 6.6501(4) Å, ? = 83.458(6)°, ? = 76.226(6)°, ? = 69.581(7)°, and V = 376.72(4) Å. The major element composition found for the studied breyite is Ca3.01(2)Si2.98(2)O9. Breyite is the second most abundant mineral inclusion after ferropericlase in diamonds of super-deep origin. The occurrence of breyite has been widely presumed to be a strong indication of lower mantle (=670 km depth) or at least lower transition zone (=520 km depth) origin of both the host diamond and the inclusion suite. In this work, we demonstrate through different formation scenarios that the finding of breyite alone in a diamond is not a reliable indicator of the formation depth in the transition zone or in the lower mantle and that accompanying paragenetic phases such as ferropericlase together with MgSiO3 are needed.
DS202107-1128
2019
Brenker, F.E.Shirey, S.B., Smit, K.V., Pearson, D.G., Walter, M.J., Aulbach, S., Brenker, F.E., Bureau, H., Burnham, A.D., Cartigny, P., Chacko, T., Frost, D.J., Hauri, E.H., Jacob, D.E., Jacobsen, S.D., Kohn, S.C., Luth, R.W., Mikhail, S., Navon, O.. Nestola, F., NimDiamonds and mantle geodynamics of carbon.Deep Carbon - Cambridge University Press , Cambridge.org 40p. PdfMantlecarbon
DS202009-1613
2020
Brenker, L.Brenker, F.E., Nestola, F., Brenker, L., Peruzzo, L., Harris, J.W.Origin, properties and structure of breyite: the second most abundant mineral inclusion in super-deep diamonds. The American Mineralogist, in press available, 21p. PdfMantlebreyite
DS202102-0176
2021
Brenker, L.Brenker, F.E., Nestola, F., Brenker, L., Peruzo, L., Harris, J.WOrigin, properties, and structure of breyite: the second most abundant mineral inclusion in super-deep diamonds.The American Mineralogist, Vol. 106, pp. 38-43. pdfMantleperovskites, mineral inclusions

Abstract: Earth's lower mantle most likely mainly consists of ferropericlase, bridgmanite, and a CaSiO3- phase in the perovskite structure. If separately trapped in diamonds, these phases can be transported to Earth's surface without reacting with the surrounding mantle. Although all inclusions will remain chemically pristine, only ferropericlase will stay in its original crystal structure, whereas in almost all cases bridgmanite and CaSiO3-perovskite will transform to their lower-pressure polymorphs. In the case of perovskite structured CaSiO3, the new structure that is formed is closely related to that of walstromite. This mineral is now approved by the IMA commission on new minerals and named breyite. The crystal structure is triclinic (space group: P1) with lattice parameters a0 = 6.6970(4) Å, b0 = 9.2986(7) Å, c0 = 6.6501(4) Å, ? = 83.458(6)°, ? = 76.226(6)°, ? = 69.581(7)°, and V = 376.72(4) Å. The major element composition found for the studied breyite is Ca3.01(2)Si2.98(2)O9. Breyite is the second most abundant mineral inclusion after ferropericlase in diamonds of super-deep origin. The occurrence of breyite has been widely presumed to be a strong indication of lower mantle (=670 km depth) or at least lower transition zone (=520 km depth) origin of both the host diamond and the inclusion suite. In this work, we demonstrate through different formation scenarios that the finding of breyite alone in a diamond is not a reliable indicator of the formation depth in the transition zone or in the lower mantle and that accompanying paragenetic phases such as ferropericlase together with MgSiO3 are needed.
DS201805-0979
2018
Brenna, M.Song, W., Xi, C., Smith, M.P., Chakhmouradian, A.R., Brenna, M., Kynicky, J., Chen, W., Yang, Y., Tang, H.Genesis of the world's largest rare earth element deposit, Bayan Obo, China: protracted mineralization evolution over ~ 1.b.y.Geology, Vol. 48, 4, pp. 323-326.Chinadeposit - Bayan Obo

Abstract: The unique, giant, rare earth element (REE) deposit at Bayan Obo, northern China, is the world’s largest REE deposit. It is geologically complex, and its genesis is still debated. Here, we report in situ Th-Pb dating and Nd isotope ratios for monazite and Sr isotope ratios for dolomite and apatite from fresh drill cores. The measured monazite ages (361-913 Ma) and previously reported whole-rock Sm-Nd data show a linear relationship with the initial Nd isotope ratio, suggesting a single-stage evolution from a Sm-Nd source that was formed before 913 Ma. All monazites show consistent ?Nd(1.3Ga) values (0.3 ± 0.6) close to those of the adjacent 1.3 Ga carbonatite and mafic dikes. The primary dolomite and apatite show lower 87Sr/86Sr ratios (0.7024-0.7030) than the recrystallized dolomite (0.7038-0.7097). The REE ores at Bayan Obo are interpreted to have originally formed as products of ca. 1.3 Ga carbonatitic magmatism and to have undergone subsequent thermal perturbations induced by Sr-rich, but REE-poor, metamorphic fluids derived from nearby sedimentary rocks.
DS201906-1363
2019
Brenna, M.Wei, C.W., Xu, C., Chakhmouradian, A.R., Brenna, M., Kynicky, J., Song, W.L.Petrogenesi of dolomite and calcite carbonatites in orogenic belts.GAC/MAC annual Meeting, 1p. Abstract p. 194.Chinadeposit - Caotan

Abstract: Subduction zones are an important way for crustal materials to enter deep parts of the Earth. Therefore, carbonatites in orogenic belt are of great significance in revealing deep carbon cycling pathways. To date, mantle-derived carbonatites have been identified in many orogenic belts, and their origin is considered to be related to subducted sediments. However, almost all orogenic carbonatites are composed of calcite, and their C isotopic compositions show typical mantle values, lacking any evidence of sedimentary origin. Here, we report decoupling of C and Sr isotopes between intimately associated dolomite and forsterite-calcite carbonatites from Caotan in the Qinling orogen, central China. The dolomite carbonatite is mainly composed of dolomite (plus minor apatite and magnetite), which has elevated ?13CPDB values (-3.1 to -3.6 ‰) and low 87Sr/86Sr ratios (0.7026-0.7042). The forsterite-calcite carbonatite consists of calcite (60-65 vol. %), forsterite and its replacement products (30-35 vol. %), and magnetite. The calcite shows mantle-like ?13CPDB (-6.2 to -7.2 ‰) but high initial 87Sr/86Sr values (0.7053-0.7076). Neodymium and Pb isotopic compositions are comparable in the two carbonatite types. The forsterite-calcite carbonatite is interpreted to have formed by metasomatic interaction of primary dolomitic melts with eclogite in thickened lower crust during collision of the North and South China cratons. The reaction resulted in decarbonation and depletion of the carbonatitic magma in 13C. Because of its initially low REE and Pb contents, the Nd-Pb isotopic signature of the primary dolomitic melt was preserved in the forsterite-calcite carbonatite. We propose that some orogenic calcite carbonatites may not be primary mantle-derived rocks and their mantle-like ?13CPDB values may be misleading.
DS202107-1092
2021
Brennan, D.T.Brennan, D.T., Li, Z-X., Rankenburg, K., Evans, N., Link, P.K.Recalibrating Rodinian rifting in the northwestern United States.Geology Today, Vol. 49, pp. 617-622.United States, Washingtongeochronology

Abstract: A lack of precise age constraints for Neoproterozoic strata in the northwestern United States (Washington State), including the Buffalo Hump Formation (BHF), has resulted in conflicting interpretations of Rodinia amalgamation and breakup processes. Previous detrital zircon (DZ) studies identified a youngest ca. 1.1 Ga DZ age population in the BHF, interpreted to reflect mostly first-cycle sourcing of unidentified but proximal magmatic rocks intruded during the amalgamation of Rodinia at ca. 1.0 Ga. Alternatively, the ca. 1.1 Ga DZ population has been suggested to represent a distal source with deposition occurring during the early phases of Rodinia rifting, more than 250 m.y. after zircon crystallization. We combined conventional laser-ablation split-stream analyses of U-Pb/Lu-Hf isotopes in zircon with a method of rapid (8 s per spot) U-Pb analysis to evaluate these opposing models. Our study of ?2000 DZ grains from the BHF identified for the first time a minor (?1%) yet significant ca. 760 Ma population, which constrains the maximum depositional age. This new geochronology implies that the BHF records early rift deposition during the breakup of Rodinia and correlates with sedimentary rocks found in other late Tonian basins of southwestern Laurentia.
DS202008-1416
2018
Brennan, M.Lobatlamang, S., Brennan, M., Davidson, J., Rogers, A.Discovery of the KX36 kimberlite.Botswana Journal of Earth Sciences, Vol. 7, pp. 29-34. pdfAfrica, Botswanadeposit - KX36

Abstract: The KX36 kimberlite pipe is situated in the southeastern part of Central Kalahari Game Reserve (CKGR), Botswana, approximately 60 km from the known Gope and Kikao kimberlite fields (see figure 1).The kimberlite is covered by 75m of Kalahari sand, has a surface area of 3.6 Ha at the base of the sand cover and was discovered by Petra Diamonds Botswana (Pty) Ltd in 2008. Application of modern geophysical techniques (Ultra hi-resolution low level flying Xcalibur magnetics) and improved sampling method led to the discovery of KX36.The kimberlite was emplaced into the Karoo Supergroup, which comprised the older sedimentary rocks (300 - 185 Ma) overlain by the flood basalts (185Ma). The Karoo Supergroup rocks are overlain by approximately 80m of Kalahari Group sediments.
DS202103-0370
2021
Brennan, M.C.Brennan, M.C., Fischer, R.A,m Couper, S., Miyagi, L., Antonangeli, D., Morard, G.High-pressure deformation of iron-nickel-silicon alloys and implications for Earth's inner core.Journal of Geophysical Research, Solid Earth, https://eartharxiv.org /repository/ view/1694/ 21p. PdfMantleGeophysics - seismics

Abstract: The inner core is a Moon?sized ball of solid metal at the very center of the Earth. Vibrations from earthquakes move faster through the inner core if they travel parallel to Earth's axis (the line between the North and South Poles) than if they travel parallel to the Equator. This probably means that the grains of metal in the inner core are themselves aligned with Earth's axis. Previous studies determined that this alignment likely happened after the inner core had formed, but those experiments were done on pure iron, whereas the inner core is mostly iron but also contains other elements. We did experiments at high pressures and temperatures on a more realistic core metal containing iron, nickel, and silicon. We found that this metal would be much stronger than pure iron at inner core pressures and temperatures; it is still possible for it to produce a north-south alignment, but it is much more difficult for it to do so. This could mean that the alignment occurred while the inner core was forming (rather than afterward), which might change how we think about the forces present in the deep Earth today.
DS1993-0161
1993
Brennand, T.A.Brennand, T.A., Sharpe, D.R.Ice sheet dynamics and subglacial melt water regime inferred from form and sedimentology of glaciofluvial systems: Victoria IslandCanadian Journal of Earth Sciences, Vol. 30, No. 5, May pp. 928-944Northwest TerritoriesGeomorphology
DS201312-0094
2013
Brenner, J.Brenner, J.Diamonds: overview from commodities session.PDAC 2013, abstract only.GlobalOverview
DS201312-0095
2013
Brenner, J.Brenner, J.A diamantaire/miner's view of the diamond market.Diamonds in Canada Magazine, Northern Miner, May pp. 10-11.Africa, South AfricaMarkets and Rockwell
DS1994-0206
1994
Brenner, M.Brenner, M., Subrahmanyam, M.G.A simple approach to option valuation and hedging in the Black-ScholesmodelFinancial Analysts Journal, March-April pp. 25-28GlobalEconomics, Options
DS1975-0870
1978
Brennesholtx, R.Smith, J.V., Brennesholtx, R.Chemistry of Micas from Kimberlites and Xenoliths. Pt. I. Micaceous Kimberlites.Geochimica Et Cosmochimica Acta, Vol. 42, PP. 959-971.South AfricaCape Province, Orange Free State, Saltpeterpan, New Elands, Dyke
DS201706-1105
2017
Brent, T.A.St. Onge, M.R., Harrison, J.C., Paul, D., Tella, S., Brent, T.A., Jauer, C.D., MacleanTectonic map of Arctic Canada (TeMAC): a first derivative product from Canada in 3-D geological compilation work.GAC annual meeting, 1p. AbstractCanadatectonics
DS201912-2786
2019
Brenton, K.Gostlin, K., Brenton, K., Liu, W., Clark, L.Gahcho Kue mine update.Yellowknife Forum NWTgeoscience.ca, abstract volume p. 57.Canada, Northwest Territoriesdeposit - Gahcho Kue

Abstract: Gahcho Kué Mine is owned as a joint venture between Mountain Province Diamonds Inc. and De Beers Canada Inc. Located about 280 km northeast of Yellowknife, it is Canada’s newest diamond mine and the world’s largest in the last 14 years. After two years of construction, commercial operations began in September 2016. As the mine enters into its fourth year of operation, De Beers is pleased to provide an update on the current mine operations, updated mine plan, safety, environment, and social performance.
DS200412-0709
2004
Breon, F-M.Grant, I.F., Heyraud, C., Breon, F-M.Continentral scale hotspot observations of Australia at sub-degree anular resolution from POLDER.International Journal of Remote Sensing, Vol. 25, 18, Sept. pp. 3625-36.AustraliaGeophysics - remote sensing
DS1983-0144
1983
Breshears, T.L.Breshears, T.L.Regional Gravity Effects of Igneous Intrusions, Central Arkansas.Msc. Thesis, University Missouri, United States, Gulf Coast, Arkansas, OklahomaGeophysics
DS1983-0145
1983
Breshears, T.L.Breshears, T.L.Regional Gravity Effects of Igneous Intrusions Central Arkansas.Missouri Acad. Science, Transactions, Vol. 17, P. 201. (abstract.).United States, Oklahoma, ArkansasGeophysics
DS201809-2060
2018
Bretschneider, L.Liu, J., Brin, L.E., Pearson, D.G., Bretschneider, L., Luguet, A., van Acken, D., Kjarsgaard, B., Riches, A., Miskovic, A.Diamondiferous Paleoproterozoic mantle roots beneath Arctic Canada: a study of mantle xenoliths from Parry Peninsula and Central Victoria Island.Geochimica et Cosmochimica Acta, doi.org/10.1016/j.gca.2018.08.010 78p.Canada, Nunavut, Parry Peninsula. Central Victoria Islandxenoliths

Abstract: While the mantle roots directly beneath Archean cratons have been relatively well studied because of their economic importance, much less is known about the genesis, age, composition and thickness of the mantle lithosphere beneath the regions that surround the cratons. Despite this knowledge gap, it is fundamentally important to establish the nature of relationships between this circum-cratonic mantle and that beneath the cratons, including the diamond potential of circum-cratonic regions. Here we present mineral and bulk elemental and isotopic compositions for kimberlite-borne mantle xenoliths from the Parry Peninsula and Central Victoria Island, Arctic Canada. These xenoliths provide key windows into the lithospheric mantle underpinning regions to the North and Northwest of the Archean Slave craton, where the presence of cratonic material has been proposed. The mantle xenolith data are supplemented by mineral concentrate data obtained during diamond exploration. The mineral and whole rock chemistry of peridotites from both localities is indistinguishable from that of typical cratonic mantle lithosphere. The cool mantle paleogeotherms defined by mineral thermobarometry reveal that the lithospheric mantle beneath the Parry Peninsula and Central Victoria Island terranes extended well into the diamond stability field at the time of kimberlite eruption, and this is consistent with the recovery of diamonds from both kimberlite fields. Bulk xenolith Se and Te contents, and highly siderophile element (including Os, Ir, Pt, Pd and Re) abundance systematics, plus corresponding depletion ages derived from Re-Os isotope data suggest that the mantle beneath these parts of Arctic Canada formed in the Paleoproterozoic Era, at ?2?Ga, rather than in the Archean. The presence of a diamondiferous Paleoproterozoic mantle root is part of the growing body of global evidence for diamond generation in mantle roots that stabilized well after the Archean. In the context of regional tectonics, we interpret the highly depleted mantle compositions beneath both studied regions as formed by mantle melting associated with hydrous metasomatism in the major Paleoproterozoic Wopmay-Great Bear-Hottah arc systems. These ?2?Ga arc systems were subsequently accreted along the margin of the Slave craton to form a craton-like thick lithosphere with diamond potential thereby demonstrating the importance of subduction accretion in building up Earth’s long-lived continental terranes.
DS201809-2062
2018
Bretschneider, L.Liu, J., Pearson, D.G., Bretschneider, L., Luguet, A., Van Acken, D., Kjarsgaard, B., Riches, A., Miskovic, A.Diamondiferous Proterozoic mantle roots beneath Arctic Canada.Goldschmidt Conference, 1p. AbstractCanada, Parry Peninsula, Victoria Islandxenoliths

Abstract: The mantle roots directly beneath Archean cratons have been relatively well studied because of their economic importance, yet much less is known about the genesis, age, composition and thickness of the mantle lithosphere beneath the regions surrounding these cratons. However, it is critically important to establish the nature of the relationship between this circum-cratonic mantle and that beneath the cratons, including the diamond potential of circum-cratonic regions. Here we present mineral and bulk elemental and isotopic compositions for kimberlite-borne mantle xenoliths from the Parry Peninsula (PP) and Central Victoria Island (CVI), Arctic Canada. These xenoliths provide key windows into the lithospheric mantle underpinning regions to the North and Northwest of the Slave craton, where the presence of cratonic mantle has been proposed. The mineral and whole rock chemistry of peridotites from both localities is indistinguishable from that of typical cratonic mantle lithosphere. The cool mantle geotherms defined by mineral thermobarometry reveal that the lithospheric mantle beneath the PP and CVI terranes extended well into the diamond stability field at the time of kimberlite eruption, consistent with the recovery of diamonds from both kimberlite fields. Bulk Se, Te, and highly siderophile element abundance systematics, plus Re-Os isotope age data suggest that the mantle beneath these parts of Arctic Canada formed at ~2 Ga, rather than in the Archean. The presence of a diamondiferous Paleoproterozoic mantle root is part of the growing body of evidence for peridotitic diamond generation in mantle roots that stabilized well after the Archean. In the context of regional tectonics, the highly depleted mantle compositions beneath both regions developed during mantle melting associated with hydrous metasomatism in the major Paleoproterozoic Wopmay- Great Bear-Hottah arc systems. These terranes were subsequently accreted along the margin of the Slave craton to form a craton-like thick lithosphere with significant diamond potential.
DS1950-0474
1959
Brett, B.A.Hartwell, J.W., Brett, B.A.Gem Stones; United States Geological Survey (usgs), 1958United States Geological Survey (USGS) MINERALS YEARBOOK, FOR 1958, PP. 467-478.Canada, British Columbia, South America, Brazil, GuyanaReview Of Current Activites
DS1960-0056
1960
Brett, B.A.Hartwell, J.W., Brett, B.A.Gem Stones; United States Geological Survey (usgs), 1960United States Geological Survey (USGS) MINERALS YEARBOOK, FOR 1959, PP. 471-483.Brazil, Guyana, Venezuela, Russia, India, Israel, GuineaReview Of Current Activities
DS1960-0151
1961
Brett, B.A.Hartwell, J.W., Brett, B.A.Gem Stones; Minerals Yearbook: Metals and Minerals, 1961Minerals Yearbook: Metals And Minerals, Vol. 1, PP. 585-596.United States, Canada, Gulf Coast, Arkansas, Pennsylvania, Russia, Brazil, TanzaniaProduction, Imports, Review
DS1960-0248
1962
Brett, B.A.Hartwell, J.W., Brett, B.A.Gems StonesUnited States Bureau of Mines MINERALS YEARBOOK FOR 1962, Vol. 1, P. 586.United States, Great LakesDiamond Occurrence
DS200912-0073
2009
Brett, C.Brett, C., Russell, J.K.Kimberlite ascent: insights from olivine.GAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyTechnologyChemical changes - melt
DS201412-0759
2014
Brett, C.Russell, K., Brett, C., Jones, T., Andrews, G., Porritt, L.Kimberlite ascent.Goldschmidt Conference 2014, 1p. AbstractMantleKimberlite genesis
DS201608-1394
2015
Brett, C.Brett, C.The scent of kimberlitic magmas.Geology Today, Vol. 31, 5, pp. 171-173.TechnologyKimberlite origin
DS201708-1603
2017
Brett, C.Brett, C.Petrology of the White River Diamondiferous Paleoproterozoic intrusive rocks.11th. International Kimberlite Conference, PosterCanada, Ontariodeposit - White River
DS201805-0937
2018
Brett, C.Brett, C.Petrology of the White River Diamondiferous Paleoproterozoic intrusive rocks and constraining the timing of destruction of the southern Superior cratonic rocks.Vancouver Kimberlite Cluster, May 3, 1p. AbstractCanada, OntarioWawa

Abstract: Diamond-bearing kimberlitic rocks have been identified as occurring within the Oskabukuta property,15km west of the town of White River, Northwestern Ontario. These rocks were emplaced within Neo-to-Mesoarchean (2.5 to 3.4 Ga) crystalline rock of the Wawa Subprovince, located within the Superior Province of North America. The emplacement age of the dyke is dated at 1945.3 ± 1.9 Ma (1?) (U-Pb in perovskite). The diamond-bearing, kimberlitic intrusion has been mapped at surface for over a 900 m strike, and is referred to as the Rabbit Foot occurrence. Geothermobarometry of the nearby Proterozoic (2.7 Ga) aged diamondiferous metaconglomerate in Wawa (90 km SE) reported a maximum geothermal gradient range between 39 and 41 mW/m2 corresponding to a minimum lithospheric thickness of the Superior Craton of 190-220 km (Miller et al., 2012). In contrast, the study highlight that younger kimberlite (e.g. ~1.1 Ga Wawa kimberlite) within the Southern Superior record a substantially warmer conductive geotherm (46 mW/m2; Kaminsky et al., 2002) and maximum depth of garnet sampled of 150 km. Miller et al. (2012) interpret the apparent heating of the mantle is likely to have resulted from the Midcontinent Rift, which is broadly coeval with the Wawa kimberlite age. Pressure-Temperature estimates calculated using garnet and clinopyroxene xenocryst mineral compositions extracted from Rabbit Foot Model are consistent with model conductive heat flow of between 38-41 mW-m-2. These data support the interpretation of Miller et al. (2012) and further constrain the presence of a cool and thick Southern Superior keel at 1945 Ma. In fact, several of our garnet compositions support a minimum lithosphere-asthenosphere boundary of 250 km in depth and suggest (along with the presence of diamond) that the Rabbit Foot intrusion transected and sampled a significant portion of depleted and diamond stable lithospheric mantle at ~1945 Ma. A later thermal event, likely related to the Mid-continental rift, has subsequently heated and thinned the Southern Superior Craton, thereby constraining timing of the cessation of diamond fertile sublithospheric mantle in the region.
DS1998-0263
1998
Brett, J.Coates, H.J., Coate, M., Brett, J.Metallic and industrial mineral assessment report on the Mustang Peace River District, Alberta.Alberta Geological Survey, MIN 19980012AlbertaExploration - assessment, CYR, International Butec
DS2000-0107
2000
Brett, J.S.Brett, J.S., Mason, R., Smith, P.H.Geophysical exploration of the Kalahari Suture ZoneJournal of African Earth Sciences, Vol. 30, No.3, pp. 489-97.BotswanaTectonics, Geophysics
DS1970-0300
1971
Brett, R.Guppy, D.J., Brett, R., Milton, D.J.Liverpool and Strangways Craters, Northern Territory. Two Structures of Probable Impact Origin.Journal of Geophysical Research, Vol. 78, No. 23, PP. 5387-5393.Australia, Northern TerritoryCryptoexplosion, Kimberlite
DS200812-0137
2007
Brett, R.C.Brett, R.C., Russell, J.K.Origin of olivine in kimberlite: phenocryst or imposter?35th. Yellowknife Geoscience Forum, Abstracts only p.5-6 .Canada, Northwest TerritoriesPetrology - Diavik
DS200812-0138
2008
Brett, R.C.Brett, R.C., Russell, J.K., Moss, S.Origins of olivine in kimberlite: phenocryst or imposter?9IKC.com, 3p. extended abstractCanada, Northwest TerritoriesDeposit - Diavik
DS200912-0074
2009
Brett, R.C.Brett, R.C., Russell, J.K., Moss, S.Origin of olivine in kimberlite: phenocryst or imposter?Lithos, In press available 49p.MantleMineral chemistry
DS201012-0517
2009
Brett, R.C.Moss, S., Russell, J.K., Brett, R.C., Andrews, G.D.M.Spatial and temporal evolution of kimberlite magma at A154N, Diavik, Northwest Territories, Canada.Lithos, Vol. 112 S pp. 541-552.Canada, Northwest TerritoriesEmplacement model
DS201012-0518
2010
Brett, R.C.Moss, S., Russell, J.K., Scott Smith, B.H., Brett, R.C.Olivine crystal size distributions in kimberlite.American Mineralogist, Vol. 95, 4, April pp. 527-536.TechnologyOlivine, morphology
DS201212-0087
2012
Brett, R.C.Brett, R.C., Russell, J.K., Andrews, G.Kimberlite ascent: chronicles of olivine.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractMantleDiamond genesis
DS201507-0305
2015
Brett, R.C.Brett, R.C.The ascent of kimberlite: insights from olivine.Earth and Planetary Science Letters, Vol. 424, pp. 119-131.Canada, Northwest Territories, Africa, TanzaniaDeposit - Diavik, Igwisi Hills

Abstract: Olivine xenocrysts are ubiquitous in kimberlite deposits worldwide and derive from the disaggregation of mantle-derived peridotitic xenoliths. Here, we provide descriptions of textural features in xenocrystic olivine from kimberlite deposits at the Diavik Diamond Mine, Canada and at Igwisi Hills volcano, Tanzania. We establish a relative sequence of textural events recorded by olivine during magma ascent through the cratonic mantle lithosphere, including: xenolith disaggregation, decompression fracturing expressed as mineral- and fluid-inclusion-rich sealed and healed cracks, grain size and shape modification by chemical dissolution and abrasion, late-stage crystallization of overgrowths on olivine xenocrysts, and lastly, mechanical milling and rounding of the olivine cargo prior to emplacement. Ascent through the lithosphere operates as a "kimberlite factory" wherein progressive upward dyke propagation of the initial carbonatitic melt fractures the overlying mantle to entrain and disaggregate mantle xenoliths. Preferential assimilation of orthopyroxene (Opx) xenocrysts by the silica-undersaturated carbonatitic melt leads to deep-seated exsolution of CO2-rich fluid generating buoyancy and supporting rapid ascent. Concomitant dissolution of olivine produces irregular-shaped relict grains preserved as cores to most kimberlitic olivine. Multiple generations of decompression cracks in olivine provide evidence for a progression in ambient fluid compositions (e.g., from carbonatitic to silicic) during ascent. Numerical modelling predicts tensile failure of xenoliths (disaggregation) and olivine (cracks) over ascent distances of 2-7 km and 15-25 km, respectively, at velocities of 0.1 to >4 m?s?1. Efficient assimilation of Opx during ascent results in a silica-enriched, olivine-saturated kimberlitic melt (i.e. SiO2 >20 wt.%) that crystallizes overgrowths on partially digested and abraded olivine xenocrysts. Olivine saturation is constrained to occur at pressures <1 GPa; an absence of decompression cracks within olivine overgrowths suggests depths <25 km. Late stage (<25 km) resurfacing and reshaping of olivine by particle-particle milling is indicative of turbulent flow conditions within a fully fluidized, gas-charged, crystal-rich magma.
DS201812-2782
2018
Brett, R.C.Brett, R.C., Kinakin, Y., Howell, D., Davy, A.T.Diavik deposit: Exploration history and discovery of the Diavik diamond deposits, Northwest Territories, Canada.Society of Economic Geology Geoscience and Exploration of the Argyle, Bunder, Diavik, and Murowa Diamond Deposits, Special Publication no. 20, pp. 253-266.Canada, Northwest Territoriesdeposit - Diavik
DS201112-0109
2009
Brett, S.C.Brett, S.C.Kimberlitic olivine.Thesis: University of British Columbia Msc., 86p.Thesis - note availability based on request to author
DS1950-0016
1950
Bretz, J.H.Bretz, J.H.Origin of the Filled Sink Structures and Circle Deposits Ofmissouri.Geological Society of America (GSA) Bulletin., Vol. 61, PP. 789-834.GlobalMid-continent
DS1995-0209
1995
Breuer, D.Breuer, D., Spohn, T.Possible flush instability in mantle convection at the Archean Proterozoictransition.Nature, Vol. 378, Dec. 7, pp. 608-610.MantleCraton, Archean, Mantle convection
DS201902-0311
2018
Breuer, D.Reudas, T., Breuer, D.Isocrater impacts: conditions and mantle dynamical responses for different impactor types.Icarus, Vol. 306, 1, pp. 94-115.Mantleimpact craters

Abstract: Impactors of different types and sizes can produce a final crater of the same diameter on a planet under certain conditions. We derive the condition for such “isocrater impacts” from scaling laws, as well as relations that describe how the different impactors affect the interior of the target planet; these relations are also valid for impacts that are too small to affect the mantle. The analysis reveals that in a given isocrater impact, asteroidal impactors produce anomalies in the interior of smaller spatial extent than cometary or similar impactors. The differences in the interior could be useful for characterizing the projectile that formed a given crater on the basis of geophysical observations and potentially offer a possibility to help constrain the demographics of the ancient impactor population. A series of numerical models of basin-forming impacts on Mercury, Venus, the Moon, and Mars illustrates the dynamical effects of the different impactor types on different planets. It shows that the signature of large impacts may be preserved to the present in Mars, the Moon, and Mercury, where convection is less vigorous and much of the anomaly merges with the growing lid. On the other hand, their signature will long have been destroyed in Venus, whose vigorous convection and recurring lithospheric instabilities obliterate larger coherent anomalies.
DS1996-0172
1996
Breunig, M.Breunig, M.Integration of spatial information for geo-information systemsSpringer Verlag, 171pGlobalGeo-Information systems, Book -ad
DS1981-0098
1981
Brewer, J.A.Brewer, J.A., Good, R., Brown, L.D., Oliver, J.E., Kaufman, S.Cocorp Seismic Reflection Traverse Across the Southern Oklahoma Aulacogen.Geological Society of America (GSA), Vol. 13, No. 7, P. 416. (abstract.).OklahomaMid-continent
DS1981-0099
1981
Brewer, J.A.Brewer, J.A., Steiner, R., Oliver, J.E., Kaufman, F., Denison, R.Proterozoic Basin in the Southern Mid-continent of the United States Revealed by Cocorp Deep Seismic Reflection Profiling.Geology, Vol. 9, No. 12, PP. 569-575.OklahomaMid-continent
DS1982-0119
1982
Brewer, J.A.Brewer, J.A., Good, R., Oliver, J.E., Brown, L.D., Kaufman, S.Cocorp Deep Seismic Reflection Profiling of the Southern Oklahoma Aulacogen.Geological Society of America (GSA), Vol. 14, No. 3, P. 106. (abstract.).OklahomaMid-continent, Geophysics
DS1982-0460
1982
Brewer, J.A.Nelson, B.K., Lillie, R.J., De voogd, B., Brewer, J.A., Oliver.Cocorp Seismic Reflection Profiling in the Ouachita MountainTectonics, Vol. 1, No. 5, PP. 413-430.United States, Gulf Coast, ArkansasBlank
DS1983-0146
1983
Brewer, J.A.Brewer, J.A.Profiling Continental Basement: the Key to Understanding Structures in the Sedimentary Cover.First Break, Vol. 1, No. 6, JUNE PP. 25-31.GlobalMid Continent
DS1983-0147
1983
Brewer, J.A.Brewer, J.A., Good, R., Oliver, J.E., Brown, L.D., Kaufman, S.Cocorp Profiling Across the Southern Oklahoma Aulacogen: Over thrusting of the Wichita Mountains and Compression Within The Anadarko Basin.Geology, Vol. 11, No. 2, PP. 109-114.OklahomaMid-continent, Geophysics
DS1983-0408
1983
Brewer, J.A.Lillie, R.J., Nelson, K.D., De voogd, B., Brewer, J.A., Oliver.Crustal Structure of Ouachita Mountains Arkansaw; a Model Based OnAmerican Association of Petroleum Geologists, Vol. 67, No. 6, PP. 907-931.GlobalMid-continent
DS1994-0207
1994
Brewer, K.J.Brewer, K.J.The mining industry in Canada: competive aspectsCanadian Institute 1994 Canadian Mining Symposium, Preprint, 41pCanadaEconomics, Mining industry -overview
DS1996-0173
1996
Brewer, K.J.Brewer, K.J., Hull, D.L.Canada's mining industry a global perspectiveNat. Res. Canada, April 120pCanadaEconomics, Exploration, mining, discoveries, legal
DS1997-0126
1997
Brewer, K.J.Brewer, K.J.Canada's global position in mining... Canadian financing of the International Mining Industry4th. Conference Finance for Global Metals Industry, May 7-9, 53pCanadaEconomics, Exploration, mining, discoveries, legal
DS1997-0127
1997
Brewer, K.J.Brewer, K.J., Bergevin, G., Arseneau, L.P.Lessons from Canadian mineral taxation: an international contextInternational Seminar on mining legislation, UN Econ. Europe, March 13-14, update June 57pCanadaEconomics, Exploration, mining, discoveries, legal
DS1975-1154
1979
Brewer, T.H.Minter, W.E.L., Brewer, T.H.Report on the Kalahari Gravel Deposits Overlying JwanengAnglo American South Africa Ltd. Geol. Records Department, South Africa, BotswanaGeomorphology
DS1992-0161
1992
Brewer, T.S.Brewer, T.S., Hergt, J.M., Hawkesworth, C.J., et al.Coats Land dolerites and the generation of Antarctic continental floodbasaltsGeological Society Special Publication Magmatism and the causes of the continental, No. 68, pp. 185-208AntarcticaBasalts, Geochemistry, signatures
DS1996-0174
1996
Brewer, T.S.Brewer, T.S.Precambrian crustal evolution in the North Atlantic regionGeological Society of London, No. 112, 390pCanada, Labrador, Baltic Shield, Sweden, Norway, ScotlandArchean mantle, paleoproterozoic, Table of contents
DS2000-0009
2000
Brewer, T.S.Ahall, K.I., Connelly, J.N., Brewer, T.S.Episodic rapakivi magmatism due to distal orogenesis? correlation of 1.69-1.50 Ga orogenic and inboard....Geology, Vol. 28, No. 9, Sept. pp. 823-6.Baltic Shield, Norway, Sweden, Finland, Russia, KolaMagmatism, Orogenic growth
DS2001-0010
2001
Brewer, T.S.Ahall, K.I., Brewer, T.S., Connelly, J.N.Deciphering the complex accretionary growth history of the Baltic Shield between 1.7 - 1.5 Ga and links...Geological Association of Canada (GAC) Annual Meeting Abstracts, Vol. 26, p.1, abstract.Baltic Shield, Baltica, LaurentiaMagmatism - intracontinental
DS2002-0205
2002
Brewer, T.S.Brewer, T.S., Ahall, K.I., Darbyshire, D., Menuge, J.Geochemistry of late Mesoproterozoic volcanism in southwestern Scandinavia: implications for ...plate..Journal of Geological Society of London, Vol. 159, 2, pp. 129-44.ScandinaviaSveconorwegian Grenvillian plate tectonic models, Tectonics
DS1859-0049
1835
Brewster, D.Brewster, D.Observations Relative to the Structure and Origin of the Diamond.Geological Society of London Transactions, 2ND. SER. Vol. 3, PP. 455-459.GlobalDiamond Genesis, Morphology
DS1859-0052
1836
Brewster, D.Brewster, D.Diamond, Matric of EtchsAmerican Journal of Science , Vol. 29, No. 2, PP. 360-GlobalGenesis
DS1988-0082
1988
Brewster, D.Brewster, D., O'Reilly, W.Magnetic properties of synthetic analogs of the altered olivines of igneousrocksGeophysic. Journal, Vol. 95, No. 2, November pp. 421-432GlobalGeothermometry, Igneous rocks
DS1989-0172
1989
Brewster, D.Brewster, D., O'Reilly, W.Thermoremanent magnetization carried by synthetic analogues of the altered olivines of igneous rocksEarth and Planetary Science Letters, Vol. 93, pp. 123-132. Database # 17941GlobalExperimental petrology, Deuteric alteration
DS1989-0173
1989
Brewster, D.Brewster, D., O'Reilly, W.Thermoremanent magnetization carries by synthetic analogues of the altered olivines of igneous rocksEarth and Planetary Science Letters, Vol. 93, 123-132GlobalGeothermometry -alteration, Olivines
DS2002-1156
2002
Brewster, N.Novak, N., Brewster, N.Gremlins, promoters, financiers, diamonds, kimberlites and other beasts. a tale of diamond exploration LowlandProspectors and Developers Association of Canada (PDAC) 2002, 2p. abstractOntario, James Bay LowlandsGeology, overview, Deposit - Spider
DS1995-1110
1995
BreyLorenz, V., Kurzlaukis, S., Stachel, T., Brey, StanistreetVolcanology of the diatreme rich carbonatitic Gross Brukkaros volcanicfield and of the near by Gibeon K.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 333-335.NamibiaCarbonatite, Deposit -Gross Brukkaros, Gibeon
DS2001-0618
2001
BreyKogarko, L.N., Ryabchikov, I.D., Brey, Santin, PachecoMantle rocks uplifted to crustal levels: diffusion profiles in minerals spinel plagioclase lherzolitesGeochemistry International, Vol. 39, No. 4, pp. 311-26.GlobalLherzolites, Tallante area
DS1975-0704
1978
Brey, G.Brey, G.Origin of Olivine Melilitites- Chemical and Experimental Constraints.Journal of Volcanology and Geothermal Research, Vol. 3, PP. 61-68.Hawaii, Texas, Germany, South Africa, Cape ProvinceMelilite
DS1983-0148
1983
Brey, G.Brey, G., Brice, W.R., et al.Pyroxene Carbonate Reactions in the Upper MantleEarth Planet. Sci. Letters, Vol. 62, No. 1, PP. 63-74.GlobalKimberlitic Magmas, Mineralogy, Melilitite
DS1984-0175
1984
Brey, G.Brey, G., Huth, J.The Enstatite Diopside Solvus to 60 KbarProceedings of Third International Kimberlite Conference, Vol. 2, PP. 257-264.GlobalChemical Composition, Genesis
DS1989-0174
1989
Brey, G.Brey, G., Kohler, T., Nickel, K.Geothermobarometry in natural four-phase lherzolites:experimentsfrom10-60kb, new thermo barometers and applicationDiamond Workshop, International Geological Congress, July 15-16th. editors, pp. 8-10. AbstractSouth AfricaGeothermometry, Geobarometry Kaapval crat
DS1989-1319
1989
Brey, G.Ryabchikov, I.D., Brey, G., Kogarko, L.N., Bulatov, V.K.Partial melting of carbonated peridotite at 50 KBAR.(Russian)Geochemistry International (Geokhimiya), (Russian), No. 1, pp. 3-9RussiaCarbonatite, Peridotite
DS1989-1320
1989
Brey, G.Ryabchikov, I.D., Brey, G., Kogarko, L.N., Bulatov, V.K.Partial melting of carbonatized peridotite at 50 kbarGeochemistry International, Vol. 26, No. 8, pp. 1-6RussiaLherzolite, Experimental petrology
DS1991-0477
1991
Brey, G.Fett, A., Brey, G.Significance of aluminum, calcium, chromium, zirconium, niobium and iron concentrations in rutile from high pressure rocksProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 92-93GlobalGeobarometry, Eclogite
DS1992-0457
1992
Brey, G.Fett, A., Brey, G., Otter, M., Harris, J.Trace elements in rutiles from diamonds: comparison with rutiles fromeclogites, granulites and amphibolites and influence of pressure andtemperatureTerra Abstracts, supplement to Terra Nova, Vol. 4, IVth International Symposium Exp. Petrology, p. 17Wyoming, AustraliaMicroscopy
DS1994-0530
1994
Brey, G.Foley, S., Hofer, H., Brey, G.high pressure synthesis of Priderite and members of Lindsleyite-mathiasite and hawthornite-Yimengite seriesContributions to Mineralogy and Petrology, Vol. 117, No. 2, July, pp. 164-174.GlobalMineralogy, Priderite
DS1995-0208
1995
Brey, G.Brenker, F., Muller, W.F., Brey, G.Microstructural minerals from the garnet lherzolite body Alpe Arami -mantle conditions and uplift history.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 66-68.GlobalLherzolites, Mantle
DS1995-0441
1995
Brey, G.Dreibus, G., Brey, G., Girnis, A.The role of carbon dioxide in the generation and emplacement of kimberlitemagmas: new exp. dat a on CO2Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 138-40.GlobalPetrology -experimental -CO2, Kimberlite magmas
DS1995-1041
1995
Brey, G.Kurszlaukis, S., Franz, L., Brey, G., Smith, C.B.Geochemistry and evolution of the ultrabasic blue hills intrusive Namibia.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 308-310.NamibiaGeochemistry, carbonatite, Blue Hills Complex
DS1995-1816
1995
Brey, G.Stachel, T., Brey, G., Lorenz, V.Carbonatite magmatism and fenitization of the epiclastic caldera fill at gross Brukkaros (Namibia).Bulletin. Volcanology, Vol. 57, pp. 185-196.NamibiaCarbonatite, Deposit -Gros Brukkaros
DS1998-0514
1998
Brey, G.Girnis, A.V., Stachel, T., Brey, G., Harris, J., PhilipInternally consistent geothermobarometers for garnet harzburgites7th International Kimberlite Conference Abstract, pp. 253-5.GlobalGeothermometry, Garnet harzburgite compositions
DS1998-1400
1998
Brey, G.Stalder, R., Foley, S.F., Brey, G., Horn, I.Mineral aqueous fluid partitioning of trace elements at 900 1200 C and 3.0- 5.7 GPa: garnet, clinopyroxeneGeochimica et Cosmochimica Acta, Vol. 62, No. 10, pp. 1781-1801.MantleMetasomatism, Petrology - experimental
DS2002-0084
2002
Brey, G.Aulbach, S., Stachel, T., Vijoen, K., Brey, G., HarrisEclogitic and websteritic diamond sources beneath the Limpopo Belt - is slab melting the link?Contribution to Mineralogy and Petrology, Vol.143, 1, Feb.pp.56-70.South AfricaDiamond - inclusions, mineralogy, Secondary Ion Mass Spectrometry, Deposit - Venetia
DS2003-0180
2003
Brey, G.Buhre, S., Steinberg, H., Brey, G., Clark, S.Trace element solubility and reaction kinetics in the CAS system8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, POSTER abstractGlobalBlank
DS200412-0236
2004
Brey, G.Buhre, S., Brey, G.Al, Li and REE solubility and partitioning between CAS phases.Lithos, ABSTRACTS only, Vol. 73, p. S15. abstractSouth America, Brazil, Africa, Guinea, Tanzania, South Africa, RussiaTool to determine ascent path and origin of diamonds
DS200412-0237
2003
Brey, G.Buhre, S., Steinberg, H., Brey, G., Clark, S.Trace element solubility and reaction kinetics in the CAS system.8 IKC Program, Session 6, POSTER abstractTechnologyMantle petrology
DS200412-1907
1992
Brey, G.Stachel, T., Brey, G.The olivine and leucite lamproite pipes of the Ellendale volcanic field ( Western Australia).Zeitschrift der Deutschen Gesellschaft fur Geowissenschaften , Vol. 143, pp. 133-158.AustraliaPetrology
DS200412-1908
1995
Brey, G.Stachel, T., Brey, G., Stanistreet, I.Gross Brukkaros (Namibia) - petrography and geochemistry of the intra-caldera sediments and their magmatic components.Communications of the Geological Survey of Namibia 1993/1994, pp. 23-42.Africa, NamibiaGeochemistry
DS200612-0172
2006
Brey, G.Brey, G., Bulatov, V., Girnis, A.Redox melting and composition of near liquidus melts of C O H bearing peridotite.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.MantleRedox melting
DS200612-0776
2006
Brey, G.Lazarov, M., Brey, G., Lahaye, Y.Mapping of the Kaapvaal craton lithosphere with garnets from a polymict peridotite.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 345. abstract only.Africa, South AfricaGeochemistry - garnets
DS200712-0410
2007
Brey, G.Hanrahan, M., Brey, G.Li as a barometer for bimineralic eclogites.Plates, Plumes, and Paradigms, 1p. abstract p. A379.MantleEclogite - marjorites
DS200912-0276
2009
Brey, G.Hannahan, M., Brey, G., Woodland, A., Altherr, R., Seitz, H-M.Li as a barometer for bimineralic eclogites: experiments in CMAS.Contributions to Mineralogy and Petrology, In press available 16p.MantleEclogite - barometry
DS200912-0277
2009
Brey, G.Hannahan, M., Brey, G., Woodland, A., Seitz, H-M., Ludwig, T.Li as a barometer for bimineralic eclogites: experiments in natural systems.Lithos, In press available, 34p.TechnologyDeposit - Roberts Victor
DS201012-0459
2010
Brey, G.Luchs, T., Brey, G., Gerdes, A.Insights on the evolution of the lithospheric mantle underneath the Gibeon kimberlite field, Namibia.Goldschmidt 2010 abstracts, posterAfrica, NamibiaDeposit - Gibeon
DS201012-0544
2010
Brey, G.Nuber, N., Gerdes, A., Brey, G., Grutter, H.Zircons from kimberlites at Lac de Gras, Canada - a section through the continental crust.International Mineralogical Association meeting August Budapest, abstract p. 561.Canada, Northwest TerritoriesDiamond morphology - size distribution
DS201012-0706
2010
Brey, G.Shu, Q., Brey, G., Aulbach, S.History of lithospheric mantle beneath western Kaapvaal Craton: signatures from subcalcic garnets.Goldschmidt 2010 abstracts, abstractAfrica, South AfricaGarnet mineralogy
DS201112-0624
2011
Brey, G.Luchs, T., Brey, G., Gerdes, A.Chronological and thermal history of the lithospheric mantle underneath the Gibeon kimberlite field, Namibia.Goldschmidt Conference 2011, abstract p.1364.Africa, NamibiaRehoboth, Hanaus, Gibeon
DS201212-0238
2012
Brey, G.Ghobadi, M., Gerdes, A., Kogarko, L., Brey, G.New dat a on the composition and hafnium isotopes of zircons from carbonatites of the Khibiny Massif.Doklady Earth Sciences, Vol. 446, 1, pp. 1083-1085.RussiaCarbonatite
DS201412-0071
2014
Brey, G.Brey, G.Geochronology of the lithospheric mantle underneath the Gibeon kimberlite field, Namibia.ima2014.co.za, AbstractAfrica, NamibiaDeposit - Gibeon
DS201708-1604
2017
Brey, G.Brey, G.The birth, growth and ageing of the Kaapvaal subcratonic mantle.11th. International Kimberlite Conference, OralAfrica, Southern AfricaSubduction, metasomatism
DS201810-2321
2018
Brey, G.Ghobadi, M., Gerdes, A., Kogarko, L., Hoefer, H., Brey, G.In situ LA-ICPMS isotopic and geochronological studies on carbonatites and phoscorites from the Guli Massif, Maymecha-Kotuy, polar Siberia.Geochemistry International, Vol. 56, 8, pp. 766-783.Russia, Siberiacarbonatite

Abstract: In this study we present a fresh isotopic data, as well as U-Pb ages from different REE-minerals in carbonatites and phoscorites of Guli massif using in situ LA-ICPMS technique. The analyses were conducted on apatites and perovskites from calcio-carbonatite and phoscorite units, as well as on pyrochlores and baddeleyites from the carbonatites. The 87Sr/86Sr ratios obtained from apatites and perovskites from the phoscorites are 0.70308-0.70314 and 0.70306-0.70313, respectively; and 0.70310-0.70325 and 0.70314-0.70327, for the pyrochlores and apatites from the carbonatites, respectively. Furthermore, the in situ laser ablation analyses of apatites and perovskites from the phoscorite yield ?Nd from 3.6 (±1) to 5.1 (±0.5) and from 3.8 (±0.5) to 4.9 (±0.5), respectively; ?Nd of apatites, perovskites and pyrochlores from carbonatite ranges from 3.2 (±0.7) to 4.9 (±0.9), 3.9 (±0.6) to 4.5 (±0.8) and 3.2 (±0.4) to 4.4 (±0.8), respectively. Laser ablation analyses of baddeleyites yielded an eHf(t)d of +8.5 (± 0.18); prior to this study Hf isotopic characteristic of Guli massif was not known. Our new in situ ?Nd, 87Sr/86Sr and eHf data on minerals in the Guli carbonatites imply a depleted source with a long time integrated high Lu/Hf, Sm/Nd, Sr/Rb ratios. In situ U-Pb age determination was performed on perovskites from the carbonatites and phoscorites and also on pyrochlores and baddeleyites from carbonatites. The co-existing pyrochlores, perovskites and baddeleyites in carbonatites yielded ages of 252.3 ± 1.9, 252.5 ± 1.5 and 250.8 ± 1.4 Ma, respectively. The perovskites from the phoscorites yielded an age of 253.8 ± 1.9 Ma. The obtained age for Guli carbonatites and phoscorites lies within the range of ages previously reported for the Siberian Flood Basalts and suggest essentially synchronous emplacement with the Permian-Triassic boundary.
DS201910-2299
2019
Brey, G.Shu, Q., Brey, G., Fichtner, C., Guelius, D.Nature and mechanisms of mantle metasomatism.Goldschmidt2019, 1p. AbstractMantlemetasomatism

Abstract: The interaction between hydrous fluids and melts with dry pre-existing mantle rocks alters the physocochemical porperties of the deep lithosphere. Here we present new insight into mantle metasomatism based on petrology, geochemistry, and Rare Earth Element (REE) distribution modelling using mantle xenoliths from various eruption centres in the Cenozoic Tariat volcanic field, Mongolia. These centres include the Horgo, Tsagan, Zala, Haer and Shavaryn-Tsaram lava flows that vary in composition and age between alkali basalts to trachybasalts to tephrite basanites and 4 ka to 1.5 Ma, respectively. Our sample suite contains xenolith from the lower crust and underlying mantle with a size range of individual xenoliths between 3 cm and 8 cm. Based on the clinopyroxene REE concentration pattern, the investigated xenoliths can be divided in two groups, characterized by LREE depletion (Group 1) and enrichment (Group 2) relative to primitive mantle. Group 1 xenoliths display well-preserved deformation textures and are considered to represent the sub-continental lithosphere prior to Cenozoic rejuvenation. In contrast, Group 2 samples are marked by partial annealing of pre-existing textures. REE distribution modelling between clinopyroxene and inferred chemically enriched basaltic melt suggests that the observed REE pattern do not reconcile with a simple mixing model but reflect chromatographic fractionation during reactive melt flow. In addition, the clinopyroxene core-rim REE variation in some of the xenoliths suggests interaction with at least one other melt of distinct chemical composition.
DS1975-0731
1978
Brey, G.P.Duncan, R.A., Hargraves, R.B., Brey, G.P.Age, Palaeomagnetism and Chemistry of Melilite Basalts in The Southern Cape, South Africa.Geology Magazine., Vol. 115, PP. 317-396.South AfricaRelated Rocks, Geochronology, Geochemistry
DS1986-0107
1986
Brey, G.P.Brey, G.P., Kogarko, L.Solubility of CO2 in kimberlitic and carbonatitic meltsProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, p. 163GlobalBlank
DS1986-0108
1986
Brey, G.P.Brey, G.P., Nickel, K.G.Experimental calibration of geothermobarometers in natural lherzolitic systems at high pressureProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, p. 228GlobalGeobarometry
DS1986-0109
1986
Brey, G.P.Brey, G.P., Nickel, K.G., Kogarko, L.Garnet pyroxene equilibration temperatures in the system CaO MgO Al2O3 SiO2(CMAS)prospects for simplified T-independent lherzolite barometry and an eclogitebarometerContributions to Mineralogy and Petrology, Vol. 92, No. 4, pp. 448-455GlobalLherzolite, Eclogite
DS1986-0301
1986
Brey, G.P.Green, D.H., Falloon, T.J., Brey, G.P., Nickel, K.G.Peridotite melting to GPa and genesis of primary mantle derived magmasProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 181-183GlobalMantle
DS1990-0235
1990
Brey, G.P.Brey, G.P., Kohler, T.Geothermobarometry in four phase Lherzolites II. New thermobarometers, and practical assessment of existing thermobarometersJournal of Petrology, Vol. 31, pt. 6, pp. 1353-1378GlobalGeothermobarometry, Lherzolites
DS1990-0236
1990
Brey, G.P.Brey, G.P., Kohler, T., Nickel, K.New pyroxene geothermobarometers and testing of existing calibrationsTerra, Abstracts of Experimental mineralogy, petrology and, Vol. 2, December abstracts p. 67GlobalGeothermobarometers, Lherzolites
DS1990-0237
1990
Brey, G.P.Brey, G.P., Kohler, T., Nickel, K.G.Geothermobarometry in four phase lherzolites I. experimental results from10 to 60 kbJournal of Petrology, Vol. 31, pt. 6, pp. 1313-1352GlobalGeothermobarometry, Lherzolites
DS1990-0855
1990
Brey, G.P.Kohler, T.P., Brey, G.P.Calcium exchange between olivine and clinopyroxene calibrated as a geothermobarometer for natural peridotites from 2 to 60 kb with applicationsGeochimica et Cosmochimica Acta, Vol. 54, pp. 2375-2388GlobalGeothermobarometry, Experimental peridotite
DS1991-0171
1991
Brey, G.P.Brey, G.P.Fictive conductive geotherms beneath the KaapvaalProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 23-25South AfricaXenoliths, Potassium, lamproites, minettes, alkali basalts, Matsoku, Bultfontein, Shaba Putsoa
DS1991-0172
1991
Brey, G.P.Brey, G.P., Doroshev, A., Kogarko, L.The join pyrope knorringite-experimental constraints for a new geothermo barometer for coexisting garnet and spinelProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 26-28GlobalMineralogy
DS1991-0173
1991
Brey, G.P.Brey, G.P., Kogarko, L.N., Ryabchik, I.D.Carbon dioxide in kimberlitic meltsNeues Jarhb. Min, No. 4, pp. 159-168GlobalExperimental petrology, CO2
DS1991-0195
1991
Brey, G.P.Bulatov, V., Brey, G.P., Foley, S.F.Origin of low Calcium, high chromium garnets by recrystallization of low pressure harzburgitesProceedings of Fifth International Kimberlite Conference held Araxa June, pp. 29-31GlobalExperimental petrology, Harzburgites -garnets
DS1991-0498
1991
Brey, G.P.Foley, S.F., Hoefer, H., Brey, G.P.The stability of priderite, lindsleyite-mathiasite andyimengite-hawthornite under lower continental lithosphere conditions:experiments at 35 to 50 KbarProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 106-108South Africa, Russia, AustraliaMicroprobe analyses, LIMA.
DS1992-0162
1992
Brey, G.P.Brey, G.P., et al.Kimberlite-peridotite equilibration temperatures at high pressureProceedings of the 29th International Geological Congress. Held Japan August 1992, Vol. 2, abstract p. 570GlobalExperimental petrology, Kimberlite
DS1994-0208
1994
Brey, G.P.Brey, G.P., Ryabchikov, I.D.Carbon dioxide in strongly silica undersaturated melts and origin Of kimberlite magmas.Neues Jahrbuch f?r Mineralogie, No. 10, Oct. pp. 449-463.MantleOlivine melilitite, kimberlite, Kimberlite genesis-magmas
DS1995-0231
1995
Brey, G.P.Bulatov, V.K., Girnis, A.V., Brey, G.P.Anhydrous partial melting of spinel lherzolites from 3.5 to 20 KBAR:composition of partial melts.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 80-82.RussiaLherzolites
DS1995-0561
1995
Brey, G.P.Franz, L., Brey, G.P., Okrusch, M.Metasomatic reequilibration of mantle xenoliths from the Gibeon kimberliteprovince.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 169-71.NamibiaXenoliths, Blue Hills, Hanaus, Anis Kubub, Hanus, Lourentsia, Gibeon
DS1995-0638
1995
Brey, G.P.Girnis, A.V., Brey, G.P., Ryabchikov, I.D.Origin of Group 1a kimberlites: fluid saturated melting experiments at45-55 kbar.Earth and Planetary Science Letters, Vol. 134, No. 3-4, Sept. 1, pp. 283-296.South AfricaKimberlites, Petrochemistry
DS1995-0879
1995
Brey, G.P.Jarick, J., Brey, G.P., Keller, J.Isotopic and chemical composition of mega and phenocrysts: evidence for the petrogenesis of Hegau volProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 263-265.EuropeAlkaline rocks
DS1995-1937
1995
Brey, G.P.Turkin, A.I., Brey, G.P., Gusak, S.N.Stability field of ferric ferrous garnet skiagiteProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 643-645.GlobalMineralogy, Garnet -pyrope
DS1996-0466
1996
Brey, G.P.Franz, L., Brey, G.P., Okrusch, M.Reequilibration of ultramafic xenoliths from Namibia by Metasomatic processes at the mantle boundary.Journal of Geology, Vol. 104, No. 5, Sept. pp. 599-615.NamibiaMantle xenoliths, Gibeon kimberlite -Hanaus and Anis Kubub pipes
DS1997-0285
1997
Brey, G.P.Doroshev, A.M., Brey, G.P., Girnis, A.V., Turkin, A.I.Pyrope - knorringite garnets in the Earth's mantle: experimental in the MgOAl2O3 SiO2 Cr2O3 systemRussian Geology and Geophysics, Vol. 38, No. 2, pp. 559-586.MantleGarnets, Petrochemistry
DS1998-1396
1998
Brey, G.P.Stachel, T., Harris, J.W., Brey, G.P.Rare and unusual mineral inclusions in diamonds from Mwadui, TanzaniaContributions to Mineralogy and Petrology, Vol. 132, No. 1, pp. 34-47.TanzaniaDiamond inclusions, Deposit - Mwadui
DS1998-1397
1998
Brey, G.P.Stachel, T., Harris, J.W., Brey, G.P.Inclusions in diamonds from Mwadui- chemical mush in the source7th International Kimberlite Conference Abstract, pp. 859-61.TanzaniaMineral inclusions, Deposit - Mwadui
DS1998-1399
1998
Brey, G.P.Stachel, T., Viljoen, K.S., Harris, J.W., Brey, G.P.rare earth elements (REE) patterms of garnets from diamonds and Diamondiferous geochemical signatures7th International Kimberlite Conference Abstract, pp. 862-4.South Africa, GhanaDiamond source, Deposit - Roberts Victor, BiriM.
DS1998-1401
1998
Brey, G.P.Stalder, R., Foley, S.F., Brey, G.P., Forsythe, HornFirst results from a new experimental technique to determine fluid/solidtrace element partition coeffic.Neues Jahrbuch f?r Mineralogie Abh., Vol. 172, No. 1, pp. 117-132.GlobalPetrology - experimental, Diamond aggregates
DS1999-0100
1999
Brey, G.P.Bulatov, V.K., Girnis, A.V., Brey, G.P.Experimental melting of spinel lherzolites and the problem of the primary magma genesis of oceanic basaltsPetrology, Vol. 7, No. 1, Jan-Feb. pp. 21-31.MantleMagma, Lherzolite - experimental petrology
DS1999-0385
1999
Brey, G.P.Kurszlaukis, S., Franz, L., Brey, G.P.The Blue Hills intrusive complex in southern Namibia - relationships between carbonatites and monticellite...Chemical Geology, Vol 160, No. 1-2, July 29, pp. 1-18.NamibiaCarbonatite, Picrites
DS1999-0707
1999
Brey, G.P.Stachel, T., Harris, J.W., Brey, G.P.rare earth elements (REE) patterns of peridotitic and eclogitic inclusions in diamonds from Mwadui ( Tanzania).7th International Kimberlite Conference Nixon, Vol. 2, pp. 829-35.TanzaniaDiamond - inclusions, geochemistry, lherzolite garnet, Deposit - Mwadui
DS2000-0922
2000
Brey, G.P.Stachel, T., Brey, G.P., Harris, J.W.Kankan diamonds I. from the lithosphere down to the transition zoneContributions to Mineralogy and Petrology, Vol. 140, No. 1, pp. 1-15.GuineaDiamond genesis, Deposit - Kankan
DS2001-1122
2001
Brey, G.P.Stachel, T., Harris, J.W., Tappert, R., Brey, G.P.Peridotitic inclusions in diamonds from the Slave and Kaapvaal cratons - afirst comparison.Slave-Kaapvaal Workshop, Sept. Ottawa, 4p. abstractNorthwest Territories, South AfricaDiamond - inclusions, Geochemistry - major and trace elements Panda
DS2002-0222
2002
Brey, G.P.Bulatov, V.K., Girnis, A.V., Brey, G.P.Experimental melting of a modally heterogeneous mantleMineralogy and Petrology, Vol.75,3-4, pp.131-52.MantleMelt
DS2002-1579
2002
Brey, G.P.Tappert, R., Stachel, T., Harris, J.W., Brey, G.P.Composition of mineral inclusions from Brazilian diamondsGac/mac Annual Meeting, Saskatoon, Abstract Volume, P.116., p.116.BrazilAlluvials, Deposit - Aranapolis, Canastra
DS2002-1580
2002
Brey, G.P.Tappert, R., Stachel, T., Harris, J.W., Brey, G.P.Composition of mineral inclusions from Brazilian diamondsGac/mac Annual Meeting, Saskatoon, Abstract Volume, P.116., p.116.BrazilAlluvials, Deposit - Aranapolis, Canastra
DS2003-0158
2003
Brey, G.P.Brey, G.P., Bulatov, V., Girnis, A., Harris, J., Stachel, T.Ferropericlase - a lower mantle phase in the upper mantle8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, AbstractGuineaMantle petrology
DS2003-0549
2003
Brey, G.P.Hanrahan, M., Stachel. T., Brey, G.P., Lahaye, Y.Garnet peridotite xenoliths from the Koffiefontein mine, South Africa8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, POSTER abstractSouth AfricaDeposit - Koffiefontein
DS2003-0594
2003
Brey, G.P.Hoeferm H.E., Brey, G.P., Woodland, A.B.Iron oxidation state of mantle minerals determined from L emission spectra by the8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, POSTER abstractGlobalBlank
DS2003-0770
2003
Brey, G.P.Lahaye, Y., Brey, G.P.Scale and timing constraints on chemical redistribution between minerals of a composite8ikc, Www.venuewest.com/8ikc/program.htm, Session 4, POSTER abstractSouth AfricaMantle geochemistry, Deposit - Kimberley
DS2003-0795
2003
Brey, G.P.Leost, I., Stachel, T., Brey, G.P., Harris, J.W., Ryabchikov, I.D.Diamond formation and source carbonation: mineral associations in diamonds fromContributions to Mineralogy and Petrology, Vol. 145, 1, pp. 15-24.NamibiaDiamond genesis
DS2003-0796
2003
Brey, G.P.Leost, I., Tachel, T., Brey, G.P., Harris, J.W.An unusual suite of inclusions in diamonds from Namibia8 Ikc Www.venuewest.com/8ikc/program.htm, Session 3, AbstractNamibiaDiamonds, Diamond - inclusions
DS2003-0797
2003
Brey, G.P.Leost, J., Stachel, T., Brey, G.P., Harris, J.W., Ryabichikov, I.D.Diamond formation and source carbonation: mineral associations in diamonds fromContribution to Mineralogy and Petrology, NamibiaDiamond mineralogy, morphology, genesis
DS2003-1248
2003
Brey, G.P.Seitz, H.M., Brey, G.P., Stachel, T., Harris, J.W.Li abundances in inclusions in diamonds from the upper and lower mantleChemical Geology, Vol. 201, 3-4, Nov. 28, pp. 307-318.MantleEclogites, peridotites, diamond
DS2003-1249
2003
Brey, G.P.Seitz, H.M., Brey, G.P., Stachel, T., Harris, J.W.Lithium abundances in inclusions in diamonds from the upper and lower mantle8ikc, Www.venuewest.com/8ikc/program.htm, Session 4, POSTER abstractMantleMantle geochemistry, Diamond - inclusions
DS2003-1250
2003
Brey, G.P.Seitz, H-M., Brey, G.P., Stahel, T., Harris, J.W.Li abundances in inclusions in diamonds from the upper and lower mantleChemical Geology, Vol. 201, 3-4, Nov. 28, pp. 307-318.MantleBlank
DS2003-1324
2003
Brey, G.P.Stachel, T., Aulbavh, S., Brey, G.P., Harris, J.W., Leost, I., Tappert, R., ViljoenDiamond formation and mantle metasomatism: a trace element perspective8 Ikc Www.venuewest.com/8ikc/program.htm, Session 3, AbstractGlobalDiamonds, database REE 135 peridotite garnet inclusions, Review - genesis
DS2003-1325
2003
Brey, G.P.Stachel, T., Harris, J.W., Tappert, R., Brey, G.P.Peridotitic diamonds from the Slave and the Kaapvaal cratons similarities andLithos, Vol. 71, 2-4, pp. 489-503.South Africa, Northwest Territories, NunavutMineral chemistry
DS2003-1359
2003
Brey, G.P.Tappert, R., Stachel, T., Harris, J.W., Brey, G.P.Mineral inclusions in diamonds from the PAnd a kimberlite, Slave Province, Canada8ikc, Www.venuewest.com/8ikc/program.htm, Session 3, POSTER abstractNorthwest TerritoriesDiamonds - inclusions, Deposit - Panda
DS200412-0205
2003
Brey, G.P.Brey, G.P., Bulatov, V., Girnis, A., Harris, J., Stachel, T.Ferropericlase - a lower mantle phase in the upper mantle.8 IKC Program, Session 6, AbstractAfrica, GuineaMantle petrology
DS200412-0206
2004
Brey, G.P.Brey, G.P., Bulatov, V., Girnis, A., Harris, J.W., Stachel, T.Ferropericlase - a lower mantle phase in the upper mantle.Lithos, Vol. 77, 1-4, Sept. pp. 655-663.South America, BrazilUHP, diamond inclusions, olivine, San Luiz
DS200412-0784
2003
Brey, G.P.Hanrahan, M., Stachel,T., Brey, G.P., Lahaye, Y.Garnet peridotite xenoliths from the Koffiefontein mine, South Africa.8 IKC Program, Session 6, POSTER abstractAfrica, South AfricaMantle petrology Deposit - Koffiefontein
DS200412-0798
2004
Brey, G.P.Harris, J.W., Stachel, T., Leost, I., Brey, G.P.Peridotitic diamonds from Namibia: constraints on the composition and evolution of their mantle source.Lithos, Vol. 77, 1-4, Sept. pp. 209-223.Africa, NamibiaPlacer, alluvials, diamond inclusions, metasomatism,REE
DS200412-0840
2003
Brey, G.P.Hoefer, H.E., Brey, G.P., Woodland, A.B.Iron oxidation state of mantle minerals determined from L emission spectra by the electron microprobe.8 IKC Program, Session 6, POSTER abstractTechnologyMantle petrology
DS200412-0933
1999
Brey, G.P.Joswig, W., Stachel, T., Harris, J.W., Baur, W.H., Brey, G.P.New Ca silicate inclusions in diamonds - tracers from the lower mantle.Earth and Planetary Science Letters, Vol. 173, pp. 1-6.TechnologyDiamond inclusions
DS200412-1116
2003
Brey, G.P.Leost, I., Stachel, T., Brey, G.P., Harris, J.W., Ryabchikov, I.D.Diamond formation and source carbonation: mineral associations in diamonds from Namibia.Contributions to Mineralogy and Petrology, Vol. 145, 1, pp. 15-24.Africa, NamibiaDiamond genesis
DS200412-1117
2003
Brey, G.P.Leost, I., Tachel, T., Brey, G.P., Harris, J.W.An unusual suite of inclusions in diamonds from Namibia.8 IKC Program, Session 3, AbstractAfrica, NamibiaDiamonds Diamond - inclusions
DS200412-1784
2003
Brey, G.P.Seitz, H-M., Brey, G.P., Stahel, T., Harris, J.W.Li abundances in inclusions in diamonds from the upper and lower mantle.Chemical Geology, Vol. 201, 3-4, Nov. 28, pp. 307-318.MantleDiamond inclusions, eclogites, peridotites, websterite.
DS200412-1905
2004
Brey, G.P.Stachel, T., Aulbach, S., Brey, G.P., Harris, J.W., Leost, I., Tappert, R., Vijoen, K.S.The trace element composition of silicate inclusions in diamonds: a review.Lithos, Vol. 77, 1-4, Sept. pp. 1-19.MantleDiamond inclusion, REE, metasomatism, lithosphere, garn
DS200412-1906
2003
Brey, G.P.Stachel, T., Aulbavh, S., Brey, G.P., Harris, J.W., Leost, I., Tappert, R., Viljoen, K.S.Diamond formation and mantle metasomatism: a trace element perspective.8 IKC Program, Session 3, AbstractTechnologyDiamonds, database REE 135 peridotite garnet inclusions Review - genesis
DS200412-1910
2003
Brey, G.P.Stachel, T., Harris, J.W., Tappert, R., Brey, G.P.Peridotitic diamonds from the Slave and the Kaapvaal cratons similarities and differences based on a preliminary dat a set.Lithos, Vol. 71, 2-4, pp. 489-503.Africa, South Africa, Northwest Territories, NunavutMineral chemistry
DS200412-1923
2004
Brey, G.P.Steinberg, H.K., Brey, G.P.Solubility of potassium and phosphorous in Ca silicates from 2 13 GPas.Lithos, ABSTRACTS only, Vol. 73, p. S107. abstractTechnologyDiamond inclusions
DS200412-1964
2004
Brey, G.P.Tappert, R., Stachel, T., Harris, J.W., Brey, G.P., Ludwig, T.Messingers from the sublithospheric mantle: diamonds and their mineral inclusions from the Jagersfontein kimberlite ( South AfriGeological Association of Canada Abstract Volume, May 12-14, SS14-11 p. 270.abstractAfrica, South AfricaDiamond inclusions, morphology
DS200412-2179
2004
Brey, G.P.Yaxley, G.M., Brey, G.P.Phase relations of carbonate bearing eclogite assemblages from 2.5 to 5.5 GPa: implications for petrogenesis of carbonatites.Contributions to Mineralogy and Petrology, Vol. 146, 5, pp. 606-619.TechnologyCarbonatite, mineralogy
DS200512-0341
2005
Brey, G.P.Girnis, A.V., Bulatov, V.K., Brey, G.P.Transition from kimberlite to carbonatite melt under mantle parameters: an experimental study.Petrology, Vol. 13, 1, pp. 1-15.Melting - kimberlite/carbonatite
DS200512-0960
2004
Brey, G.P.Seitz, H-M., Brey, G.P., Lahaye, Y., Durali, S., Weyer, S.Lithium isotopic signatures of peridotite xenoliths and isotopic fractionation at high temperature between olivine and pyroxenes.Chemical Geology, Vol. 212, 1-2, pp. 163-177.MantlePetrology - not specific to diamonds
DS200512-1039
2005
Brey, G.P.Stachel, T., Brey, G.P., Harris, J.W.Inclusions in sublithospheric diamonds: glimpses of deep Earth.Elements, Vol. 1, 2, March pp. 73-79.MantleDiamond inclusion, majorite, perovskite, subduction
DS200512-1074
2005
Brey, G.P.Tappert, R., Stachel, T., Harris, J.W., Shimizu, N., Brey, G.P.Mineral inclusions in diamonds from the PAnd a kimberlite, Slave Province, Canada.European Journal of Mineralogy, Vol. 17, 3, pp. 423-440.Canada, Northwest TerritoriesMineralogy - Panda
DS200612-0464
2006
Brey, G.P.Girnis, A.V., Bulatov, V.K., Lahaye, Y., Brey, G.P.Partitioning of trace elements between carbonate silicate melts and mantle minerals: experiment and petrological consequences.Petrology, Vol. 14, 5, pp. 492-514.MantleMelts
DS200612-0592
2006
Brey, G.P.Hofer, H.E., Brey, G.P., Yaxley, G.M., Berry, A.J.Iron oxidation state determination in garnets by EPMA and XANES.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 256. abstract only.TechnologyGarnet geochemistry
DS200612-0708
2006
Brey, G.P.Klama, K., Lahaye, Y., Weyer, S., Brey, G.P.Episodic versus long tern recycling processes within the Archean South African crust.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 21. abstract only.Africa, South AfricaSubduction
DS200612-1241
2006
Brey, G.P.Schmidt, A., Weyer, S., Brey, G.P.BSE reservoirs: insights from Nb/Ta of rutile bearing eclogites.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 10, abstract only.MantleEclogite - niobium, tantalum
DS200612-1260
2006
Brey, G.P.Seitz, H.M., Brey, G.P., Harris, J.W., Ludwig, T.Lithium isotope composition of lower mantle ferropericlase inclusions in diamonds from Sao Luiz, Brazil.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 17. abstract only.South America, BrazilDeposit - Sao Luiz, diamond inclusions
DS200612-1412
2006
Brey, G.P.Tappert, R., Stachel, T., Harris, J.W., Muehlenbachs, K., Brey, G.P.Placer diamonds from Brazil: indicators of the composition of the Earth's mantle and the distance to their kimberlitic sources.Economic Geology, Vol. 101, 2, pp. 543-470.South America, Brazil, Mato Grosso, Roraima, Minas GeraisDiamond morphology, inclusions
DS200612-1413
2005
Brey, G.P.Tappert, R., Stachel, T., Harris, J.W., Muehlenbachs, K., Ludwig, T., Brey, G.P.Diamonds from Jagersfontein (South Africa): messengers from the sublithopheric mantle.Contributions to Mineralogy and Petrology, Vol. 150, 5, pp. 505-522.Africa, South AfricaDiamond inclusions
DS200612-1414
2006
Brey, G.P.Tappert, R., Stachel, T., Muehlenbachs, K., Harris, J.W., Brey, G.P.Alluvial diamonds from Brazil: where and what are their sources?Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 4. abstract onlySouth America, BrazilDiamond genesis
DS200612-1523
2006
Brey, G.P.Weyer, S., Ionov, D.A., Hellebrand, E., Woodland, A.B., Brey, G.P.Iron isotope fractionation as indicator of mantle processes.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 16 abstract only.MantleGeochemistry - iron
DS200712-0601
2007
Brey, G.P.Lazarov, M., Brey, G.P., HHHarris, J.W., Weyer, S.Timing of mantle depletion and enrichment from single subcalcic garnet grains (Finsch mine, SA).Plates, Plumes, and Paradigms, 1p. abstract p. A551.Africa, South AfricaFinsch
DS200712-0952
2007
Brey, G.P.Schmidt, A., Weyer, S., Xiao, Y., Hoefs, J., Brey, G.P.Lu Hf geochronology of eclogites from the Dabie Sulu terrain: constraints on the timing of eclogite facies metamorphism.Plates, Plumes, and Paradigms, 1p. abstract p. A894.ChinaUHP
DS200712-1202
2007
Brey, G.P.Yaxley, G.M., Spandler, C.S., Green, D.H., Rosenthal, A., Brey, G.P.The influence of minor elements on melting of eclogite in the mantle.Plates, Plumes, and Paradigms, 1p. abstract p. A1143.MantleMelting
DS200812-0139
2007
Brey, G.P.Brey, G.P., Bulatov, V.K., Girnis, A.V.Geobarometry for peridotites: experiments in simple and natural systems from 6 to 10 GPa.Journal of Petrology, Vol. 49, 1, pp. 3-24.TechnologyGarnet
DS200812-0140
2008
Brey, G.P.Brey, G.P., Bulatov, V.K., Girnis, A.V.Experimental melting of magnesite bearing peridotite with H2O and F at 6 - 10 GPa, and implications for the genesis of kimberlites.9IKC.com, 3p. extended abstractMantleMelting
DS200812-0141
2008
Brey, G.P.Brey, G.P., Bulatov, V.K., Girnis, A.V., Lahaye, Y.Experimental melting of carbonated peridotite at 6-10 GPa.Journal of Petrology, Vol. 49, 4, pp. 797-821.MantleMelting
DS200812-0484
2008
Brey, G.P.Hopp, J., Trieloff, M., Brey, G.P., Woodland, A.B., Simon, N.S.C., Wijbrans, J.R., Siebel, W., Reitter, E.40 Ar 39 Ar ages of phlogopite in mantle xenoliths from South African kimberlites: evidence for metasomatic mantle impregnation during Kilbaran orogenic cycle.Lithos, Vol. 106, no. 3-4, pp. 351-364.Africa, South Africa, LesothoDeposit - Bultfontein, Letseng, Liqhobong
DS200812-0624
2008
Brey, G.P.Lahaye, Y., Kogarko, L.N., Brey, G.P.Isotopic (Nd, Hf, Sr) composition of super large rare metal deposits from the Kola Peninsula using in-situ LA MC ICPMS9IKC.com, 3p. extended abstractRussia, Kola PeninsulaDeposit - Khibina, Lovosero
DS200812-1019
2008
Brey, G.P.Schmidt, A., Weyer, S., John, T., Brey, G.P.Nb Ta systematics of orogenic eclogites.Goldschmidt Conference 2008, Abstract p.A833.MantleEclogite
DS200812-1020
2008
Brey, G.P.Schmidt, A., Weyer, S., Mezger, K., Scherer, E.E., Xiao, Y., Hoefs, J., Brey, G.P.Rapid eclogization of the Dabie Sulu UHP terrane: constraints from Lu Hf garnet geochronology.Earth and Planetary Science Letters, Vol. 273, 1-2, Aug. 30, pp. 203-213.ChinaUHP
DS200812-1021
2008
Brey, G.P.Schmidt, A., Weyer, S., Mezger, K., Scherer, E.E., Xiao, Y., Hoefs, J., Brey, G.P.Rapid eclogitization of the Dabie Sulu UHP terrane: constraints from Lu Hf garnet geochronology.Earth and Planetary Science Letters, In press available, 49p.ChinaUHP
DS200812-1035
2008
Brey, G.P.Seitz, H-M., Brey, G.P.Lithium abundances and Li isotope compositions of the Roberts Victor kimberlite and its olivines.9IKC.com, 3p. extended abstractAfrica, South AfricaDeposit - Roberts Victor
DS200912-0075
2009
Brey, G.P.Brey, G.P., Bulato, V.K., Girnis, A.V.Influence of water and fluorine on melting of carbonated peridotite at 6 and 10 GPa.Lithos, In press availableMantleMelting
DS200912-0084
2009
Brey, G.P.Bulatov, V.K., Girnis, A.V., Brey, G.P.Experimental melting of carbonated K rich garnet harzburgite and origin of kimberlite melts.alkaline09.narod.ru ENGLISH, May 10, 2p. abstractTechnologyMelting
DS200912-0252
2009
Brey, G.P.Girnis, A.V., Bulatov, V.K., Brey, G.P.Influence of melt compositions on Fe, Mn and Ni partitioning between carbonate silicate melts and mantle minerals: experiments and applications.....alkaline09.narod.ru ENGLISH, May 10, 2p. abstractTechnologyGenesis of kimberlites and inclusions in diamonds
DS200912-0307
2009
Brey, G.P.Hofer, H.E., Lazarov, M., Brey, G.P., Woodland, A.B.Oxygen fugacity of the metasomatizing melt in a polymict peridotite from Kimberley.Lithos, In press - available 25p.Africa, South AfricaDeposit - Kimberley
DS200912-0393
2009
Brey, G.P.Kogarko,N.,Lahaye, Y., Brey, G.P.Plume related mantle source of super large rare metal deposits from the Lovozero and Khibin a massifs on the Kola Peninsula, east Baltic Shield: Sr, Nd, Hf isotope ssytematics.Mineralogy and Petrology, in press availableEurope, Baltic Shield, Kola PeninsulaAlkalic
DS200912-0428
2009
Brey, G.P.Lazarov, M., Brey, G.P., Weyer, S.Time steps of depletion and enrichment in the Kaapvaal Craton as recorded by subcalcic garnets from Finsch (SA).Earth and Planetary Science Letters, Vol. 279, 1-2, pp. 1-10.Africa, South AfricaGeochronology deposit - Finsch
DS200912-0674
2009
Brey, G.P.Schmidt, A., Weyer, S., John, T., Brey, G.P.HFSE systematics of rutile bearing eclogites: new insights into subduction zone processes and implications for the Earth's HPSE budget.Geochimica et Cosmochimica Acta, Vol. 73, 2, pp. 455-468.MantleSubduction
DS201012-0426
2009
Brey, G.P.Lazarov, M., Woodland, A.B., Brey, G.P.Thermal state and redox conditions of the Kaapvaal mantle: a study of the Finsch mine, South Africa.Lithos, Vol. 112 S pp. 913-923.Africa, South AfricaGeothermometry
DS201112-0110
2011
Brey, G.P.Brey, G.P., Bulatov, V.K., Girnis, A.V.Melting of K rich carbonated peridotite at 6 - 10 GPa and the stability of K phases in the upper mantle.Chemical Geology, Vol. 281, 3-4, pp. 333-342.MantleCratonic geothermometry
DS201112-0364
2011
Brey, G.P.Ghobadi, M., Gerdes, A., Brey, G.P., Hofer, H & E., Keller, J.In situ trace element and U Pb and Sr and Nd isotope analysis of accessory phases in Kaiserstuhl carbonatites.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.48-50.Europe, GermanyKaiserstuhl
DS201112-0365
2011
Brey, G.P.Ghobadi, M., Gerdes, A., Brey, G.P., Hofer, H & E., Keller, J.In situ trace element and U Pb and Sr and Nd isotope analysis of accessory phases in Kaiserstuhl carbonatites.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p.48-50.Europe, GermanyKaiserstuhl
DS201112-0366
2011
Brey, G.P.Ghobadi, M., Gerdes, A., Brey, G.P., Hofer, H.E., Keller, J.In-situ trace element and U-Pb, Sr and Nd isotope analysis of accessory phases in Kaiserstuhl cabonatites.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterEurope, GermanyCarbonatite
DS201112-0371
2011
Brey, G.P.Girnis, A.V., Bulatov, V.K., Brey, G.P.Formation of primary kimberlite melts - constraints from experiments at 6-12 GPa and variable CO2/H2O.Lithos, In press available, 42p.TechnologyMelting
DS201112-0372
2011
Brey, G.P.Girnis, A.V., Bulatov, V.K., Brey, G.P.Formation of primary kimberlite melts - constraints from experiments at 6-12 GPa and variable CO2/H2O.Lithos, Vol. 127, 3-4, Dec. pp. 401-413.TechnologyMelting
DS201112-0956
2011
Brey, G.P.Shu, Q., Brey, G.P.Ultra depleted eclogites: residues of TTG melting.Goldschmidt Conference 2011, abstract p.1866.Africa, South AfricaDeposit - Bellsbank
DS201212-0041
2012
Brey, G.P.Aulbach, S., Stachel, T., Seitz, H-M., Brey, G.P.Chalcophile and siderophile elements in sulphide inclusions in eclogitic diamonds and metal cycling in a Paleoproterozoic subduction zone.Geochimica et Cosmochimica Acta, Vol 93, Sept. 15, pp. 278-299.Canada, Northwest TerritoriesDeposit - Diavik
DS201212-0088
2012
Brey, G.P.Brey, G.P., Luchs, T., Shu, Q., Lazarov, M., Becker, H.Combined trace element, SM-ND, Luf-Hf and Re-Os studies constrain the age, origin and the development of the Kaapvaal subcratonic mantle.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractAfrica, South AfricaGeochemistry
DS201212-0089
2012
Brey, G.P.Brey, G.P., Weyer, S.Evolution of the South Africa mantle - a case study of garnet peridotites from the Finsch diamond mine ( Kaapvaal craton) part 2: multiple depletion and re-enrichment processes.Lithos, In press available 49p.Africa, South AfricaDeposit - Finsch
DS201212-0237
2012
Brey, G.P.Ghobadi, M., Gerdes, A., Brey, G.P., Hofer, H.E., Keller, J.In situ trace element and U Pb and Sr Nd isotope analysis of accessory phases in Kaiserstuhl carbonatites.emc2012 @ uni-frankfurt.de, 1p. AbstractEurope, GermanyCarbonatite
DS201212-0398
2012
Brey, G.P.Lazarov, M., Brey, G.P., Weyer, S.Evolution of the South Africa mantle - a case study of garnet peridotites from the Finsch diamond mine ( Kaapvaal craton) part 1: inter-mineral trace element and isotopic equilibrium.Lithos, in press available 55p.Africa, South AfricaDeposit - Finsch
DS201212-0424
2012
Brey, G.P.Luchs, T., Brey, G.P., Gerdes, A., Hoefer, H.E.Lu-Hf and Sm-Nd geochronology and geothermobarmetry of the lithospheric mantle beneath the Gibeon kimberlite field, Namibia.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractAfrica, NamibiaDeposit - Gibeon
DS201212-0652
2012
Brey, G.P.Shu, Q., Brey, G.P., Gerdes, A., Hoefer, H.E.Ultra depleted eclogites: residues of TTG melting.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractAfrica, South AfricaDeposit - Bellsbank
DS201212-0653
2012
Brey, G.P.Shu, Q., Brey, G.P., Gerdes, A., Hofer, H.E., Seitz, H.M.Eclogites and garnet pyroxenites from the mantle: their age and ageing- two point isochrons, Sm-Nd and Lu-Hf closure temperatures, model ages.emc2012 @ uni-frankfurt.de, 1p. AbstractAfrica, South AfricaDeposit - Bellsbank
DS201312-0040
2013
Brey, G.P.Aulbach, S., Luchs, T., Brey, G.P.Distribution and behaviour during metasomatism of PGE-Re and Os isotopes in off-craton mantle xenoliths from Namibia. Lithos, Vol. 184-187, pp. 478-490.Africa, NamibiaGibeon field
DS201312-0096
2013
Brey, G.P.Brey, G.P.Storage of Hadean Oceanic crust in the Kaapvaal subcratonic mantle.Goldschmidt 2013, AbstractAfrica, South AfricaHadean
DS201312-0097
2013
Brey, G.P.Brey, G.P.Geochronology of the lithospheric mantle underneath the Gibeon kimberlite field, Namibia.Goldschmidt 2013, AbstractAfrica, NamibiaGibeon
DS201312-0312
2013
Brey, G.P.Girnis, A.V., Bulatov, V.K., Brey, G.P., Gerdes, A., Hofer, H.E.Trace element partitioning between mantle minerals and silico-carbonate melts at 6-12 Gpa and applications to mantle metasomatism and kimberlite genesis.Lithos, Vol. 160-161, pp. 183-200.MantleKimberlite genesis, melting
DS201312-0555
2013
Brey, G.P.Luchs, T., Brey, G.P., Gerdes, A., Hofer, H.E.The lithospheric mantle underneath the Gibeon kimberlite field ( Namibia): a mix of old and young components - evidence from Lu-Hf and Sm-Nd isotope systematics.Precambrian Research, Vol. 231, pp. 263-276.Africa, NamibiaDeposit - Gibeon
DS201312-0722
2013
Brey, G.P.Purwin, H., Lauterbach, S., Brey, G.P., Woodland, A.B., Kleebe, H-J.An experimental study of Fe oxidation states in garnet and clinopyroxene as a function of temperature in the system CaO FeO Fe2O3 MgO Al2O3 SiO2: implications for garnet-clinopyroxene geothermometry.Contributions to Mineralogy and Petrology, Vol. 164, 4, pp. 623-639.TechnologyGeobarometry
DS201312-0820
2013
Brey, G.P.Shu, Q., Brey, G.P., Gerdes, A., Hoefer, H.E.Geochronological and geochemical constraints on the formation and evolution of the mantle beneath the Kaapvaal craton: Lu Hf and Sm Nd systematics of subcalcic garnets from highly depleted peridotites.Geochimica et Cosmochimica Acta, Vol. 113, pp. 1-20.Africa, South AfricaDeposit - Roberst Victor, Lace
DS201312-0821
2013
Brey, G.P.Shu, Q., Brey, G.P., Gerdes, A., Hoefer, H.E.Simultaneous mantle metasomatism, diamond growth and crustal events in the Archean and Proterozoic of South Africa.Goldschmidt 2013, AbstractAfrica, South AfricaMetasomatism
DS201312-0824
2013
Brey, G.P.Sieber, M., Brey, G.P., Seitz, H-M., Gerdes, A., Hoefer, H.E.The age of eclogitisation underneath the Kaapvaal craton - a composite xenolith from Roberts Victor.Goldschmidt 2013, 1p. AbstractAfrica, South AfricaDeposit - Roberts Victor
DS201412-0559
2014
Brey, G.P.Matjuschkin, V., Brey, G.P.The influence of Fe3+ on garnet-orthopy roxene and garnet-olivine geothermometers.Contributions to Mineralogy and Petrology, Vol. 167, pp. 972- ( 11p).TechnologyGeothermometry
DS201412-0822
2014
Brey, G.P.Shu, Q., Brey, G.P., Gerdes, A., Hoefer, H.E.Mantle eclogites and garnet pyroxenites - the meaning of two point isochrons, Sm-Nd and Lu-Hf closure temperatures and the cooling of the subcratonic mantle.Earth and Planetary Science Letters, Vol. 389, pp. 143-154.MantleGeochronology
DS201504-0217
2015
Brey, G.P.Shu, Q., Brey, G.P.Ancient mantle metsomatism recorded in subcalcic garnet xenocrysts: temporal links between mantle metasomatism, diamond growth and crustal tectonomagmatism.Earth and Planetary Science Letters, Vol. 418, pp. 27-39.MantleMetasomatism
DS201509-0386
2015
Brey, G.P.Brey, G.P., Girnis, A.V., Bulatov, V.K., Hofer, H.E., Gerdes, A., Woodland, A.B.Reduced sediment melting at 7.5-12 Gpa: phase relations, geochemical signals and diamond nucleation.Contributions to Mineralogy and Petrology, Vol. 170, 25p.TechnologyExperimental petrology

Abstract: Melting of carbonated sediment in the presence of graphite or diamond was experimentally investigated at 7.5–12 GPa and 800–1600 °C in a multianvil apparatus. Two starting materials similar to GLOSS of Plank and Langmuir (Chem Geol 145:325–394, 1998) were prepared from oxides, carbonates, hydroxides and graphite. One mixture (Na-gloss) was identical in major element composition to GLOSS, and the other was poorer in Na and richer in K (K-gloss). Both starting mixtures contained ~6 wt% CO2 and 7 wt% H2O and were doped at a ~100 ppm level with a number of trace elements, including REE, LILE and HFSE. The near-solidus mineral assemblage contained a silica polymorph (coesite or stishovite), garnet, kyanite, clinopyroxene, carbonates (aragonite and magnesite-siderite solid solution), zircon, rutile, bearthite and hydrous phases (phengite and lawsonite at <9 GPa and the hydrous aluminosilicates topaz-OH and phase egg at >10 GPa). Hydrous phases disappear at ~900 °C, and carbonates persist up to 1000-1100 °C. At temperatures >1200 °C, the mineral assemblage consists of coesite or stishovite, kyanite and garnet. Clinopyroxene stability depends strongly on the Na content in the starting mixture; it remains in the Na-gloss composition up to 1600 °C at 12 GPa, but was not observed in K-gloss experiments above 1200 °C. The composition of melt or fluid changes gradually with increasing temperature from hydrous carbonate-rich (<10 wt% SiO2) at 800-1000 °C to volatile-rich silicate liquids (up to 40 wt% SiO2) at high temperatures. Trace elements were analyzed in melts and crystalline phases by LA ICP MS. The garnet-melt and clinopyroxene-melt partition coefficients are in general consistent with results from the literature for volatile-free systems and silicocarbonate melts derived by melting carbonated peridotites. Most trace elements are strongly incompatible in kyanite and silica polymorphs (D < 0.01), except for V, Cr and Ni, which are slightly compatible in kyanite (D > 1). Aragonite and Fe-Mg carbonate have very different REE partition coefficients (D Mst-Sd/L ~ 0.01 and D Arg/L ~ 1). Nb, Ta, Zr and Hf are strongly incompatible in both carbonates. The bearthite/melt partition coefficients are very high for LREE (>10) and decrease to ~1 for HREE. All HFSE are strongly incompatible in bearthite. In contrast, Ta, Nb, Zr and Hf are moderately to strongly compatible in ZrSiO4 and TiO2 phases. Based on the obtained partition coefficients, the composition of a mobile phase derived by sediment melting in deep subduction zones was calculated. This phase is strongly enriched in incompatible elements and displays a pronounced negative Ta-Nb anomaly but no Zr-Hf anomaly. Although all experiments were conducted in the diamond stability field, only graphite was observed in low-temperature experiments. Spontaneous diamond nucleation and the complete transformation of graphite to diamond were observed at temperatures above 1200-1300 °C. We speculate that the observed character of graphite-diamond transformation is controlled by relationships between the kinetics of metastable graphite dissolution and diamond nucleation in a hydrous silicocarbonate melt that is oversaturated in C.
DS201603-0420
2016
Brey, G.P.Shu, Q., Brey, G.P., Hoefer, H.E., Zhao, Z., Pearson, D.G.Kyanite/corundum eclogites from the Kaapvaal craton: subducted troctolites and layered gabbros from the Mid- to Early Archean.Contributions to Mineralogy and Petrology, Vol. 171, 11, 24p.Africa, South AfricaDeposit - Bellsbank

Abstract: An oceanic crustal origin is the commonly accepted paradigm for mantle-derived eclogites. However, the significance of the aluminous members of the eclogite suite, containing kyanite and corundum, has long been underrated and their role neglected in genetic models of cratonic evolution. Here, we present a geochemical and petrological study of a suite of kyanite- and corundum-bearing eclogites from the Bellsbank kimberlite, S. Africa, which originate from depths between 150 and 200 km. Although clearly of high-pressure provenance, these rocks had a low-pressure cumulative origin with plagioclase and olivine as major cumulate phases. This is shown by the very pronounced positive Eu anomalies, low REE abundances, and ? 18O values lower than the Earth’s mantle. Many chemical features are identical to modern-day troctolitic cumulates including a light REE depletion akin to MORB, but there are also distinguishing features in that the eclogites are richer in Na, Fe, and Ni. Two of the eclogites have a minimum age of ~3.2 Ga, defined by the extremely unradiogenic 87Sr/86Sr (0.7007) in clinopyroxene. Phase equilibria indicate that the parent melts were formed by partial melting below an Archean volcanic center that generated (alkali-)picritic to high-alumina tholeiitic melts from a mantle whose oxygen fugacity was lower than today. Fractional crystallization produced troctolites with immiscible sulfide melt droplets within the mafic crust. Instability of the mafic crust led to deep subduction and re-equilibration at 4 6 GPa. Phase relationships plus the presence of a sample with appreciable modal corundum but no Eu anomaly suggest that kyanite- and corundum-bearing eclogites may also originate as plagioclase-free, higher pressure cumulates of highly aluminous clinopyroxene, spinel, and olivine. This is consistent with the crystallizing phase assemblage from an olivine tholeiitic to picritic magma deeper in the Archean oceanic crust or uppermost mantle. We postulate that the magmatic and subduction processes driving modern plate tectonics already existed in the Meso- to Early Archean.
DS201805-0945
2018
Brey, G.P.Girnis, A.V., Brey, G.P., Bulatov, V.K., Hofer, H.E., Woodland, A.B.Graphite to diamond transformation during sediment-peridotite interaction at 7.5 and 10.5 Gpa.Lithos, in press available 42p.Mantleperidotites

Abstract: Diamond nucleation and growth were investigated experimentally at 7.5 and 10.5?GPa and temperatures up to 1500?°C. Samples consisted of two layers: i) H2O- and CO2-bearing model sediment and ii) graphite-bearing garnet harzburgite comprising natural minerals. Two experimental series were conducted, one under a controlled temperature gradient with the sedimentary layer usually in the cold zone and the other under isothermal conditions. In the latter case, diamond seeds were added to the sedimentary mixture. During the experiments, the sedimentary layer partially or completely melted, with the melt percolating and interacting with the adjacent harzburgite. The graphite-to-diamond transition in the peridotite was observed above 1300?°C at 7.5?GPa and 1200?°C at 10.5?GPa in the temperature-gradient experiments, and at temperatures ~100?°C lower in the isothermal experiments with diamond seeds. Newly formed diamond occurs mostly as individual grains up to 10??m in size and is separate from graphite aggregates. In some cases, an association of diamond with magnesite was observed. Diamond nucleation occurs in hydrous and CO2-bearing silicate melt following graphite dissolution and recrystallization. In the case of the diamond-magnesite association, diamond was probably formed through carbonate reduction coupled with graphite oxidation. The composition of the melts ranged from “carbonatitic” with ~10?wt% SiO2 and?>?50?wt% volatiles to hydrous silicate with ~40?wt% SiO2 and?
DS201806-1248
2018
Brey, G.P.Seitz, H-M., Brey, G.P., Harris, J.W., Durali-Muller, S., Ludwig, T., Hofer, H.E.Ferropericlase inclusions in ultradeep diamonds from Sao Luiz ( Brazil): high Li abundances and diverse Li-isotope and trace element compositions suggest an origin from a subduction melange.Mineralogy and Petrology, in press available, 10p.South America, Brazil, Juinadeposit - Sao Luiz

Abstract: The most remarkable feature of the inclusion suite in ultradeep alluvial and kimberlitic diamonds from Sao Luiz (Juina area in Brazil) is the enormous range in Mg# [100xMg/(Mg?+?Fe)] of the ferropericlases (fper). The Mg-richer ferropericlases are from the boundary to the lower mantle or from the lower mantle itself when they coexist with ringwoodite or Mg- perovskite (bridgmanite). This, however, is not an explanation for the more Fe-rich members and a lowermost mantle or a “D” layer origin has been proposed for them. Such a suggested ultra-deep origin separates the Fe-rich fper-bearing diamonds from the rest of the Sao Luiz ultradeep diamond inclusion suite, which also contains Ca-rich phases. These are now thought to have an origin in the uppermost lower mantle and in the transition zone and to belong either to a peridotitic or mafic (subducted oceanic crust) protolith lithology. We analysed a new set of more Fe-rich ferropericlase inclusions from 10 Sao Luiz ultradeep alluvial diamonds for their Li isotope composition by solution MC-ICP-MS (multi collector inductively coupled plasma mass spectrometry), their major and minor elements by EPMA (electron probe micro-analyser) and their Li-contents by SIMS (secondary ion mass spectrometry), with the aim to understand the origin of the ferropericlase protoliths. Our new data confirm the wide range of ferropericlase Mg# that were reported before and augment the known lack of correlation between major and minor elements. Four pooled ferropericlase inclusions from four diamonds provided sufficient material to determine for the first time their Li isotope composition, which ranges from ?7Li?+?9.6 ‰ to ?3.9 ‰. This wide Li isotopic range encompasses that of serpentinized ocean floor peridotites including rodingites and ophicarbonates, fresh and altered MORB (mid ocean ridge basalt), seafloor sediments and of eclogites. This large range in Li isotopic composition, up to 5 times higher than ‘primitive upper mantle’ Li-abundances, and an extremely large and incoherent range in Mg# and Cr, Ni, Mn, Na contents in the ferropericlase inclusions suggests that their protoliths were members of the above lithologies. This mélange of altered rocks originally contained a variety of carbonates (calcite, magnesite, dolomite, siderite) and brucite as the secondary products in veins and as patches and Ca-rich members like rodingites and ophicarbonates. Dehydration and redox reactions during or after deep subduction into the transition zone and the upper parts of the lower mantle led to the formation of diamond and ferropericlase inclusions with variable compositions and a predominance of the Ca-rich, high-pressure silicate inclusions. We suggest that the latter originated from peridotites, mafic rocks and sedimentary rocks as redox products between calcite and SiO2.
DS201807-1480
2018
Brey, G.P.Brey, G.P., Shu, Q.The birth, growth and ageing of the Kaapvaal subcratonic mantle.Mineralogy and Petrology, 10.1007/ s00710-018- 0577-8, 19p. Africametasomatism, subduction, geobarometry

Abstract: The Kaapvaal craton and its underlying mantle is probably one of the best studied Archean entity in the world. Despite that, discussion is still vivid on important aspects. A major debate over the last few decades is the depth of melting that generated the mantle nuclei of cratons. Our new evaluation of melting parameters in peridotite residues shows that the Cr2O3/Al2O3 ratio is the most useful pressure sensitive melting barometer. It irrevocably constrains the pressure of melting (melt separation) to less than 2 GPa with olivine (ol), orthopyroxene (opx) and spinel (sp) as residual phases. Garnet (grt) grows at increasing pressure during lithosphere thickening and subduction via the reaction opx?+?sp ? grt?+?ol. The time of partial melting is constrained by Re-depletion model ages (TRD) mainly to the Archean (Pearson and Wittig 2008). However, only 3% of the ages are older than 3.1 Ga while crustal ages lie mainly between 3.1 to 2.8 Ga for the W- and 3.7 to 2.8 Ga for the E-block. Many TRD-ages are probably falsified by metasomatism and the main partial melting period was older than 3.1 Ga. Also, Nd- and Hf- model ages of peridotitic lithologies from the W-block are 3.2 to 3.6 Ga old. The corresponding very negative ?Nd (?40) and ?Hf values (?65) signal the presence of subducted crustal components in these old mantle portions. Subducted components diversify the mantle in its chemistry and thermal structure. Adjustment towards a stable configuration occurs by fluid transfer, metasomatism, partial melting and heat transfer. Ages of metasomatism from the Lu-Hf isotope system are 3.2 Ga (Lace), 2.9 Ga (Roberts Victor) and 2.62 Ga (Finsch) coinciding with the collision of cratonic blocks, the growth of diamonds, metamorphism of eclogites and of Ventersdoorp magmatism. The cratonic lithosphere was stabilized thermally by the end of the Archean and cooled since then with a rate of 0.07 °C/Ma.
DS201807-1525
2018
Brey, G.P.Shu, Q., Brey, G.P., Pearson, D.G.Eclogites and garnet pyroxenites from Kimberley, Kaapvaal craton, South Africa: their diverse origins and complex metasomatic signatures.Mineralogy and Petrology, June 14, DOI:10.1007/ s00710-018 -0595-6, 16p.Africa, South Africadeposit - Boshof

Abstract: We describe the petrography and mineral chemistry of sixteen eclogite and garnet pyroxenite xenoliths from the reworked Boshof road dump (Kimberley) and define three groups that stem from different depths. Group A, the shallowest derived, has low HREE (heavy rare earth element) abundances, flat middle to heavy REE patterns and high Mg# [= 100•Mg/(Mg?+?Fe)]. Their protoliths probably were higher pressure cumulates (~ 0.7 GPa) of mainly clinopyroxene (cpx) and subordinate orthopyroxene (opx) and olivine (ol). Group B1 xenoliths, derived from the graphite/diamond boundary and below show similarities to present-day N-MORB that were modified by partial melting (higher Mg# and positively inclined MREE (middle REE) and HREE (heavy REE) patterns of calculated bulk rocks). Group B2 samples from greatest depth are unique amongst eclogites reported so far worldwide. The calculated bulk rocks have humped REE patterns with very low La and Lu and prominent maxima at Sm or Eu and anomalously high Na2O (up to 5 wt%) which makes protolith identification difficult. The complex trace element signatures of the full spectrum of Kimberley eclogites belie a multi-stage history of melt depletion and metasomatism with the introduction of new phases especially of phlogopite (phlog). Phlogopite appears to be characteristic for Kimberley eclogites and garnet peridotites. Modelling the metasomatic overprint indicates that groups A and B1 were overprinted by volatile- and potassium-rich melts probably by a process of chromatographic fractionation. Using constraints from other metasomatized Kimberley mantle rocks suggest that much of the metasomatic phlogopite in the eclogites formed during an intense episode of metasomatism that affected the mantle beneath this region 1.1 Gyr ago.
DS201908-1815
2019
Brey, G.P.Shu, Q, Brey, G.P., Pearson, G., Liu, J., Gibson, S.A., Becker, H.The evolution of the Kaapvaal craton: a multi-isotopic perspective from lithospheric peridotites from Finsch diamond mine.Precambrian Research, 105380, 21p. PdfAfrica, South Africadeposit - Finsch

Abstract: Accurately dating the formation and modification of Earth’s sub-cratonic mantle still faces many challenges, primarily due to the long and complex history of depletion and subsequent metasomatism of this reservoir. In an attempt to improve this, we carried out the first study on peridotites from the Kaapvaal craton (Finsch Mine) that integrates results from Re-Os, Lu-Hf, Sm-Nd and Sr-isotope systems together with analyses of major-, trace- and platinum-group elements. The Finsch peridotites are well-suited for such a study because certain compositional features reflect they were highly depleted residues of shallow melting (1.5?GPa) at ambient Archean mantle temperatures. Yet, many of them have overabundant orthopyroxene, garnet and clinopyroxene compared to expected modal amounts for residues from partial melting. Finsch peridotites exhibit a wide range of rhenium depletion ages (TRD) from present day to 2.7?Ga, with a prominent mode at 2.5?Ga. This age overlaps well with a Lu-Hf isochron of 2.64?Ga (?Hf (t)?=?+26) which records silico-carbonatitic metasomatism of the refractory residues. This late Archean metasomatism is manifested by positive correlations of Pt/Ir and Pd/Ir with 187Os/188Os ratios and good correlations of modal amounts of silicates, especially garnet, with Os isotope ratios. These correlations suggest that the Highly Siderophile Elements (HSE) and incompatible element reenrichment and modal metasomatism result from one single major metasomatic event at late Archean. Our detailed study of Finsch peridotites highlights the importance of using multiple isotopic systems, to constrain the ages of events defining the evolution of lithospheric mantle. The Re-Os isotope system is very effective in documenting the presence of Archean lithosphere, but only the oldest TRD ages may accurately date or closely approach the age of the last major partial melting event. For a meaningful interpretation of the Re-Os isotope systematics the data must be combined with HSE patterns, trace-element compositions and ideally other isotopic systems, e.g. Lu-Hf. This is highlighted by the widespread evidence in Finsch peridotites of Pt, Pd and Re enrichment through significant Base Metal Sulfide (BMS) addition (mainly in the range of 0.002-0.08?wt%) that systematically shifts the mode of TRD model ages to younger ages.
DS202103-0414
2021
Brey, G.P.Sudholz, Z.J., Yaxley, G.M., Jaques, A.L., Brey, G.P.Experimental recalibration of the Cr-in-clinpyroxene geobarometer: improved precision and reliability above 4.5 Gpa.Contributions to Mineralogy and Petrology, Vol. 176, 10.1007/s0041 0-020-01768-z 21p. PdfMantlegeothermometry

Abstract: The pressure dependence of the exchange of Cr between clinopyroxene and garnet in peridotite is applicable as a geobarometer for mantle-derived Cr-diopside xenocrysts and xenoliths. The most widely used calibration (Nimis and Taylor Contrib Miner Petrol 139: 541-554, 2000; herein NT00) performs well at pressures below 4.5 GPa, but has been shown to consistently underestimate pressures above 4.5 GPa. We have experimentally re-examined this exchange reaction over an extended pressure, temperature, and compositional range using multi-anvil, belt, and piston cylinder apparatuses. Twenty-nine experiments were completed between 3-7 GPa, and 1100-1400 °C in a variety of compositionally complex lherzolitic systems. These experiments are used in conjunction with several published experimental datasets to present a modified calibration of the widely-used NT00 Cr-in-clinopyroxene (Cr-in-cpx) single crystal geobarometer. Our updated calibration calculates P (GPa) as a function of T (K), CaCr Tschermak activity in clinopyroxene (acpxCaCrTs), and Cr/(Cr?+?Al) (Cr#) in clinopyroxene. Rearranging experimental results into a 2n polynomial using multiple linear regression found the following expression for pressure: P(GPa)=11.03+(?T(K) ln(acpxCaCrTs)×0.001088)+(1.526×ln(Cr#cpxT(K))) where Cr#cpx=(CrCr+Al), acpxCaCrTs=Cr?0.81?Cr#cpx?(Na+K), with all mineral components calculated assuming six oxygen anions per formula unit in clinopyroxene. Temperature (K) may be calculated through a variety of geothermometers, however, we recommend the NT00 single crystal, enstatite-in-clinopyroxene (en-in-cpx) geothermometer. The pressure uncertainty of our updated calibration has been propagated by incorporating all analytical and experimental uncertainties. We have found that pressure estimates below 4 GPa, between 4-6 GPa and above 6 GPa have associated uncertainties of 0.31, 0.35, and 0.41 GPa, respectively. Pressures calculated using our calibration of the Cr-in-cpx geobarometer are in good agreement between 2-7 GPa, and 900-1400 °C with those estimated from widely-used two-phase geobarometers based on the solubility of alumina in orthopyroxene coexisting with garnet. Application of our updated calibration to suites of well-equilibrated garnet lherzolite and garnet pyroxenite xenoliths and xenocrysts from the Diavik-Ekati kimberlite and the Argyle lamproite pipes confirm the accuracy and precision of our modified geobarometer, and show that PT estimates using our revised geobarometer result in systematically steeper paleogeotherms and higher estimates of the lithosphere?asthenosphere boundary compared with the original NT00 calibration.
DS202203-0347
2022
Brey, G.P.Ghobadi, M., Brey, G.P., Gerdes, A., Hofer, H.E., Keller, J.Accessories in Kaiserstuhl carbonatites and related rocks as accurate and faithful recorders of whole rock age and isotopic composition.International Journal of Earth Science, Vol. 111, 2, 16p.Europe, Germanycarbonatite

Abstract: The accessories perovskite, pyrochlore, zirconolite, calzirtite and melanite from carbonatites and carbonate-rich foidites from the Kaiserstuhl are variously suited for the in situ determination of their U-Pb ages and Sr, Nd- and Hf-isotope ratios by LA-ICP-MS. The 143Nd/144Nd ratios may be determined precisely in all five phases, the 176Hf/177Hf ratios only in calzirtite and the 87Sr/86Sr ratios in perovskites and pyrochlores. The carbonatites and carbonate-rich foidites belong to one of the three magmatic groups that Schleicher et al. (1990) distinguished in the Kaiserstuhl on the basis of their Sr, Nd and Pb isotope ratios. Tephrites, phonolites and essexites (nepheline monzogabbros) form the second and limburgites (nepheline basanites) and olivine nephelinites the third. Our 87Sr/86Sr isotope data from the accessories overlap with the carbonatite and olivine nephelinite fields defined by Schleicher et al. (1990) but exhibit a much narrower range. These and the ?Nd and ?Hf values plot along the mantle array in the field of oceanic island basalts relatively close to mid-ocean ridge basalts. Previously reported K-Ar, Ar-Ar and fission track ages for the Kaiserstuhl lie between 16.2 and 17.8 Ma. They stem entirely from the geologically older tephrites, phonolites and essexites. No ages existed so far for the geologically younger carbonatites and carbonate-rich foidites except for one apatite fission track age (15.8 Ma). We obtained precise U-Pb ages for zirconolites and calzirtites of 15.66, respectively 15.5 Ma (±?0.1 2?) and for pyrochlores of 15.35?±?0.24 Ma. Only the perovskites from the Badberg soevite yielded a U-P concordia age of 14.56?±?0.86 Ma while the perovskites from bergalites (haüyne melilitites) only gave 206Pb/238U and 208Pb/232Th ages of 15.26?±?0.21, respectively, 15.28?±?0.48 Ma. The main Kaiserstuhl rock types were emplaced over a time span of 1.6 Ma almost 1 million years before the carbonatites and carbonate-rich foidites. These were emplaced within only 0.32 Ma.
DS1900-0109
1902
Brezina, A.Brezina, A., Cohen, E.Ueber Ein Meteoreisen von Mukerop, Bezirk Gibeon, Grossnamaland. Ueber Ein Meteoreisen von Mukerop, Bezirk Gibeon, Gross Namaland.Jh. Ver. Vaterl. Naturk. Wuertt., Vol. 58, PP. 292-302. ALSO: Neues Jahrbuch f?r Mineralogie 1903 BD. 1, PPSouthwest Africa, Namibia, JerusalemMeteorite, Brukkaros
DS201608-1419
2016
Briais, A.Maia, M., Sichel, S., Briais, A., Brunelli, D., Ligi, M., Ferreira, N., Campos, T., Mougel, B., Brehme, I., Hemond, C., Motoki, A., Moura, D., Scalabrin, C., Pessanha, I., Alves, E., Ayres, A., Oliveira, P.Extreme mantle uplift and exhumation along a transpressive transform fault.Nature Geoscience, Vol. 9, 8, pp. 619-623.MantleRidges

Abstract: Mantle exhumation at slow-spreading ridges is favoured by extensional tectonics through low-angle detachment faults1, 2, 3, 4, and, along transforms, by transtension due to changes in ridge/transform geometry5, 6. Less common, exhumation by compressive stresses has been proposed for the large-offset transforms of the equatorial Atlantic7, 8. Here we show, using high-resolution bathymetry, seismic and gravity data, that the northern transform fault of the St Paul system has been controlled by compressive deformation since ~10?million years ago. The long-lived transpression resulted from ridge overlap due to the propagation of the northern Mid-Atlantic Ridge segment into the transform domain, which induced the migration and segmentation of the transform fault creating restraining stepovers. An anticlockwise change in plate motion at ~11?million years ago5 initially favoured extension in the left-stepping transform, triggering the formation of a transverse ridge, later uplifted through transpression, forming the St Peter and St Paul islets. Enhanced melt supply at the ridge axis due to the nearby Sierra Leone thermo chemical anomaly9 is responsible for the robust response of the northern Mid-Atlantic Ridge segment to the kinematic change. The long-lived process at the origin of the compressive stresses is directly linked to the nature of the underlying mantle and not to a change in the far-field stress regime.
DS201312-0088
2013
Briand, X.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
DS2000-0108
2000
Brice, T.Brice, T.Acquisition and processing of single sensor seismic dataPreview ( Australia Exploration Geophys), Aug. pp. 21-23, 4.GlobalGeophysics - seismics, Not specific to diamonds
DS1990-0238
1990
Brice, W.C.Brice, W.C., Lehmann, E.K., Beck, J.W., Knoll, A.Mining in Minnesota: balancing environmental protection and economicdevelopmentAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint, No. 90-26, 10pMinnesotaLaw, Mining regulations
DS1991-0174
1991
Brice, W.C.Brice, W.C., Lewis, K.A.Exploration and development of minerals in MinnesotaSkillings Mining Review, Vol. 80, No. 40, October 5, pp. 4-7MinnesotaGeneral overview of exploration
DS1983-0148
1983
Brice, W.R.Brey, G., Brice, W.R., et al.Pyroxene Carbonate Reactions in the Upper MantleEarth Planet. Sci. Letters, Vol. 62, No. 1, PP. 63-74.GlobalKimberlitic Magmas, Mineralogy, Melilitite
DS1990-0239
1990
Briceno, H.Briceno, H., Schubert, C., Paolini, J.Table -mountain geology and surficial geochemistry: Chimanta Massif, Venezuelan Guyana ShieldJournal of South American Earth Sciences, Vol. 3, No. 4, pp. 179-194VenezuelaShield, Geochemistry
DS1982-0120
1982
Briceno, H.O.Briceno, H.O.Application of Remote Sensing to Diamond Placer Explorationin a Tropical Jungle Environment Caroni River, Venezuela.Ph.d. Thesis, Colorado School of Mines, 176P.South America, VenezuelaRegional Geology, Remote Sensing, Slar, Leaneaments, Kimberlite
DS1982-0121
1982
Briceno, H.O.Briceno, H.O., Lee, K.Application of Land sat Dat a to Geologic Mapping Tropical Jungle Environment, Caroni River Basin, Venezuela.International Symposium on Remote Sensing of Environment Proceedings, 16TH. Vol. 1, PP. 123-133.GlobalSide, Scanning Radar, Diamonds
DS1985-0084
1985
Briceno, H.O.Briceno, H.O.Genesis of Venezuelan Ore Deposits. 2. Diamond Placers of San Salvador de Paul.Act. Cient., Vol. 36, No. 2, PP. 154-158.South America, VenezuelaGeomorphology, Mineralogy
DS1992-1500
1992
Brich, W.D.Sutherland, F.L., Hollis, J.D., Brich, W.D.Xenolith samples of a young mantle crust magma chamber, related to the Newer basalts of western VIC and relevant to the southeast Australia geotherm.11th. Australian Geol. Convention Held Ballarat University College, Jan., Listing of papers to be given attempting to get volAustraliaMantle, Xenoliths
DS202102-0222
2020
Brichkin, V.N.Sizyakov, V.M., Kawalla, R., Brichkin, V.N.Geochemical aspects of the mining and processing of the large tonne mineral resources of the hibinian alkaline massif.Geochemistry, Vol. 80, doi.org/10.1016 /j.chemer.2019 .04.002 5p. PdfRussiadeposit - Khibiny

Abstract: This article presents an analysis of the influences of nature and production factors relating to the chemical-mineralogical composition of products that formed at the stages of mining and processing apatite-nepheline ores in the Khibiny Mountain Massif. It is shown that all main production processes are connected to the formation of dump waste products that are subject to further changes under the influence of exogenous factors, which include conditions of outdoor storage in dumps and sludge accumulators. According to the dead tails (stale tails) of apatite production, the characteristic changes in the chemical-mineralogical composition and grain-size distribution are determined and have a significant effect on the indicators of their mineral processing. The experimental study of dead tails includes processing a set of technological operations, and their flowsheets are also determined. These flowsheets provide a nepheline concentrate of the required composition with indicators no worse than when processing the tailings of the current composition. It is shown that the existing flowsheets for apatite or nepheline concentrate processing lead to the accumulation of significant amounts of mulls associated with the separation of less valuable components of raw materials into the dump waste products, including calcium and silica. The experimental work also demonstrates the conversion process of gypsum wastes produced during the production of phosphoric acid and shows the importance of additional hydrochemical treatment of belite mull to achieve an economically justified ratio of the main and by-products in the processing of aluminosilicate raw materials.
DS1981-0100
1981
Brichta, A.Brichta, A.Sedimentology and Genesis of Diamondiferous Conglomerates Of Diamantina, Minas Gerais, Lower Proterozoic Eastern Brasil.Freiburg: Ph.d. Thesis, University Freiburg, 48P. 6 TABLES, 20 PL. BGR-1981 B 1693.Brazil, Minas GeraisSedimentology, Genesis, Precambrian Conglomerate
DS201312-0098
2013
Brick, R.Brick, R.World's oldest eclogites? equilibration temperatures constraints on 2 Ga metalpelitic hosted eclogites from the Usagaran Orogen, Tanzania.Goldschmidt 2013, AbstractAfrica, TanzaniaEclogite
DS201312-0948
2013
Brick, R.Walsh, A., Hand, M., Collins, A., Brick, R.World's oldest eclogites? Phase equilibration temperatures constraints on 2 Ga metaleitic hosted eclogites frm the Usagaran orogen, Tanzania.Goldschmidt 2013, 1p. AbstractAfrica, TanzaniaEclogite
DS1988-0083
1988
Briddon, P.Briddon, P., Jones, R., Lister, G.M.S.Hydrogen in diamondJournal of Phys. Cond.: Solid State Physics, Vol. 21, No. 30, pp. L1027-L1031GlobalDiamond morphology
DS2003-0487
2003
Briddon, P.R.Goss, J.P., Coomer, B.J., Jones, R., Fall, C.J., Briddon, P.R., Oberg, S.Extended defects in diamond: the interstitial plateletPhysical Review, Vol. 67, 16, 15p.GlobalBlank
DS200412-0700
2003
Briddon, P.R.Goss, J.P., Coomer, B.J., Jones, R., Fall, C.J., Briddon, P.R., Oberg, S.Extended defects in diamond: the interstitial platelet.Physical Review Letters, Vol. 67, 16, 15p.TechnologyDiamond - morphology
DS200512-0355
2004
Briddon, P.R.Goss, J.P., Briddon, P.R., Papagiannidis, S., Jones, R.Interstitial nitrogen and its complexes in diamond.Physical Review Letters, Vol. 70, 23, pp. 235208.Diamond inclusions
DS200612-0082
2006
Briddon, P.R.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
DS200612-0604
2006
Briddon, P.R.Hounsome, L.S., Jones, R., Martineau, P.M., Fisher, D., Shaw, M.J., Briddon, P.R., Oberg, S.Origin of brown coloration in diamond.Physical Review Letters, Vol. 73, 12, pp. 125203 ( 8 pages)TechnologyDiamond - colour
DS200712-0051
2006
Briddon, P.R.Bangert, U., Barnes, R., Hounsome, L.S., Jones, R., Bhumenau, 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. 4757-4779.TechnologyType IIa diamonds
DS200712-0387
2007
Briddon, P.R.Gross, J.P., Briddon, P.R., Shaw, M.J.Density functional simulations of silicon containing point defects in diamond.Physical Review Letters, Vol. 76, 7, pp. 075204. Ingenta 1074186736TechnologyDiamond morphology
DS201112-0382
2011
Briddon, P.R.Goss, J.P., Ewels, C.P., Briddon, P.R., Fritsch, E.Bistable N2-H complexes: the first proprosed structure of a H-related colour causing defect in diamond.Diamond and Related Materials, Vol. 20, 7, pp. 896-901.TechnologyDiamond chameleon
DS1981-0101
1981
Briden, J.C.Briden, J.C., Whitcombe, D.N., Stuart, G.W., Fairhead, J.D.Depth of Geological Contact Across the West African Craton Margin.Nature., Vol. 292, JULY 9TH., PP. 123-128.West Africa, Senegal, GuineaTectonics
DS1997-1229
1997
Bridge, G.Warhurst, A., Bridge, G.Economic liberalisation, innovation, and technology transfer: opportunities for cleaner production..Nat. Res. forum, Vol. 21, No. 1, pp. 1-12GlobalEconomics, Mining industry - production, environmental, legal
DS1930-0018
1930
Bridge, J.Bridge, J.Geology of the Eminence and Cardareva QuadranglesMissouri Bureau of Geology And Mines, SER. 2, Vol. 24, No. 228, 4P.Missouri, United States, Central StatesAlnoite, Related Rocks, Avon Diatreme
DS1993-0162
1993
Bridge, J.S.Bridge, J.S.Description and interpretation of fluvial deposits: a critical perspective #1Sedimentology, Vol. 40, No. 4, August, pp. 801-810GlobalAlluvial deposits, Review -brief of fluvial deposits
DS1994-0209
1994
Bridge, J.S.Bridge, J.S.The interaction between channel geometry, water flow, sediment transportand deposition in braided riversBest, and Bristow, Braided Rivers Geological Society of London, No. 75, pp. 13-71GlobalSedimentology, Geomorphology, Channel geometry
DS1950-0128
1953
Bridge, T.Bridge, T.The Petrology and Petrography of the Igneous Rocks of Rileycounty, Kansas.Msc. Thesis, Kansas State University, GlobalKimberlite, Mineralogy, Petrology
DS201604-0626
2016
Bridges, D.L.Shavers, E.J., Ghulam, A., Encarnacion, J., Bridges, D.L., Luetemeyer, P.B.Carbonatite associated with the ultramafic diatremes in the Avon volcanic district, Missouri, USA: field, petrographic and geochemical constraints.Lithos, Vol. 248, pp. 506-516.United States, MissouriCarbonatite

Abstract: Here we report field, petrographic, and geochemical analyses of the southeast Missouri Avon Volcanic District intrusive rocks and present the first combined textural and geochemical evidence for the presence of a primary magmatic carbonatite phase among ultramafic dikes, pipes, and diatremes of olivine melilitite, alnöite, and calciocarbonatite. The ?13CVPDB values measured for primary calciocarbonatite as well as carbonates in olivine melilitite and alnöite rocks range from ? 3.8‰ to ? 8.2‰, which are within the typical range of mantle values and are distinct from values of the carbonate country rocks, 0.0‰ to ? 1.3‰. The carbonate oxygen isotope compositions for the intrusive lithologies are in the range of 21.5‰ to 26.2‰ (VSMOW), consistent with post-emplacement low temperature hydrothermal alteration or kinetic fractionation effects associated with decompression and devolatilization. Metasomatized country rock and breccia-contaminated igneous lithologies have carbonate ?13CVPDB values gradational between primary carbonatite values and country rock values. Unaltered sedimentary dolomite breccia and mafic spheroids entrained by calciocarbonatite and the lack of microstratigraphic crystal growth typical of carbonate replacement, also exclude the possibility of hydrothermal replacement as the cause of the magmatic-textured carbonates. Rare earth element (REE) patterns for the alnöite, olivine melilitite, and carbonatite are similar to each other with strong light REE enrichment and heavy REE depletion relative to MORB. These patterns are distinct from those of country rock rhyolite and sedimentary carbonate. These data suggest that rocks of the Avon Volcanic District represent a single ultramafic-carbonatite intrusive complex possibly derived from a single mantle source.
DS201610-1861
2016
Bridges, D.L.Freeman, Z.W., Hames, W., Bridges, D.L.The Devonian Avon alkaline province, Missouri: characterization of subcontinental mantle source and evolution from olivine phenocrysts.GSA Annual Meeting, 1/2p. abstractUnited States, MissouriAlnoite, melilitite

Abstract: We present new data on the crystallization age of, and composition of olivine phenocrysts within, an alnöite and olivine melilitite of the Avon Alkalic Igneous Province (AAIP) of Missouri. The AAIP is an ultramafic igneous province consisting of more than 80 known lithologically and texturally diverse intrusions, cropping out in northeastern flank of the St. Francois Mtn. Terrane. 40Ar/39Ar geochronology of biotite phenocrysts constrains emplacement to 386 +/- 1 Ma. Xenocrystic biotite from one sample yields 40Ar/39Ar age spectra characteristic of episodic loss, indicating crystallization at ca. 1.3 Ga followed by partial loss in the ultramafic magma at 386 Ma. Olivines within the alnöite are subhedral, variably serpentinized, and embayed. Olivines within the melilitite are euhedral, but extensively serpentinized. Disequilibrium textures observed in alnöite olivine are consistent with resorption of magmatic olivine as a result of decompression during crystallization. Euhedral olivine within the melilitite appear to have remained in equilibrium with melt, suggesting derivation of alnöite and melilitite from unique magmas. Major and trace elemental abundances of olivine from the alnöite were characterized with electron probe microanalysis. Olivines are Mg-rich (Fo86.9-Fo89.9), and exhibit systematic variation in trace element (e.g., Ni (1627 to 3580 ppm), Cr (97 to 1603 ppm), Co (149 to 259 ppm), Ti (11 to 267 ppm), Al (undetectable to 923 ppm), and P (undetectable to 433 ppm)) abundances with decreasing forsterite content consistent with fractional crystallization. All geothermometers yield a range in temperature, e.g., the Al in olivine (De Hoog et al., 2009) yield temperatures of 1087° to 1313° C at depths of 80 km to 180 km (modern-day midcontinental LAB). Olivine trace element discrimination diagrams indicate AAIP magmas were derived from mantle sources with an alkalic affinity, similar to other continental alkaline rocks and kimberlite. A mantle origin via partial melting of carbonated peridotite mantle is suggested due to the high Mg content, results of geothermometric modeling, and high Ca and Ti abundance within olivine phenocrysts. Melting of the mantle may have ben triggered by "Acadian" tectonic events.
DS1990-0240
1990
Bridges, S.R.Bridges, S.R.The future of desk top computers in geophysicsLeading Edge of Exploration (Geophysics News letter), Vol. 9, No. 3, March pp. 17-21GlobalComputers, Geophysics
DS1991-0175
1991
Bridgett, I.S.Bridgett, I.S., Miller, T.R.United States Geological Survey (USGS) Library /SIGCAT CD-ROM compendiuMUnited States Geological Survey (USGS) Open File, No. 91-0040, 171p. paper copy $ 26.50GlobalLibrary, Compendium of CD-ROM.
DS1999-0797
1999
BridgewaterWilligers, B.J.A., Mengel, F.C., Bridgewater, WijbransMafic dike swarms as absolute time markers in high grade terranes: 40Ar39Ar geochronological constraintsGeology, Vol. 27, No. 9, Sept. pp. 775-8.GreenlandKangamiut dikes, Geochronology
DS1989-0175
1989
Bridgewater, D.Bridgewater, D.Fluid movements - element transport and the composition of the deepKluwer Academic Publ, 395pGlobalCrust -fluid, Mantle
DS1989-1142
1989
Bridgewater, D.Nutman, A.P., Fryer, B.J., Bridgewater, D.The Early Archean Nulliak (supracrustal assemblage, northern Labrador)Canadian Journal of Earth Sciences, Vol. 26, pp. 2159-68.Labrador, QuebecRegional setting
DS1989-1353
1989
Bridgewater, D.Schiotte, L., Compston, W., Bridgewater, D.Ion probe uranium-thorium-lead-zircon dating of polymetamorphic orthogneisses from northern Labrador.Canadian Journal of Earth Sciences, Vol. 26, pp. 1533-56.Labrador, QuebecGeochronology
DS1989-1354
1989
Bridgewater, D.Schiotte, L., Compston, W., Bridgewater, D.Uranium-thorium-lead ages of single zircons in Archean supracrustals from Nain Labrador.Canadian Journal of Earth Sciences, Vol. 26, pp. 2636-44.Labrador, QuebecGeochronology
DS1997-0971
1997
Bridgewater, D.Romer, R.L., Bridgewater, D.Geochronologic significance of lead lines from old cratonsChemical Geology, Vol. 136, No. 1/2, March 27, pp. 125-134.Craton, Geochronology
DS1994-1884
1994
Bridgewaterm D.Wardle, R.J., Bridgewaterm D., Menegl, Cambell, et al.Mapping in the Torngat Orogen, no. 3 the Nain Craton.. ultramafic dyke occurrences in northern most LabradorNewfld. Department of Mines, Report, No. 94-1, pp. 399-407.Quebec, Ungava, LabradorNain Craton
DS2003-1468
2003
Bridgland, D.Westaway, R., Bridgland, D., Mishra, S.Rheological differences between Archean and younger crust can determine rates ofTerra Nova, Vol. 15, pp. 287-298.South Africa, AustraliaTectonics, geomorphology
DS200412-2102
2003
Bridgland, D.Westaway, R., Bridgland, D., Mishra, S.Rheological differences between Archean and younger crust can determine rates of Quaternary vertical motions revealed by fluvialTerra Nova, Vol. 15, pp. 287-298.Africa, South Africa, AustraliaTectonics, geomorphology
DS1910-0460
1915
Bridgman, H.B.Bridgman, H.B.Gems; Brooklyn: Priv. Publishing, 1915Brooklyn: Priv. Publishing, 117P.GlobalKimberley, Diamonds
DS1991-0176
1991
Bridgwater, D.Bridgwater, D.The Anabar shield field conference July 17-27 Siberia 1990Geoscience Canada, Vol. 18, No. 1, March pp. 28-32RussiaPrecambrian shield, Conference report
DS1996-1213
1996
Bridgwater, D.Rosing, M.T., Rose, N.M., Bridgwater, D., Thomsen, H.S.Earliest part of Earth's stratigraphic record: a reappraisal of the >3.7 GaIsua supracrustal sequenceGeology, Vol. 24, No. 1, Jan. pp. 43-46GreenlandArchean crust, Stratigraphy
DS201412-0072
2014
Briers, C.Briers, C.The importance of asset management systems in Rockwell Diamonds.GSSA Kimberley Diamond Symposium and Trade Show provisional programme, Sept. 10-12, POSTERAfrica, South AfricaMetallurgy
DS200612-0675
2006
BriesacherKeller, G.R., Hildenbrand, Kucks, Webring, Briesacher, Rujawitz, Hittleman, Roman, Winester, Aldouri et al.A community effort to construct a gravity database for the United States and an associated Web portal.In: Sinha, A.K. Geoinformatics: data to knowledge, GSA Special Paper, 397, 397, pp.21-34 rUnited StatesGeophysics - gravity data
DS200512-0114
2005
Brietkreuz, C.Brietkreuz, C., Petford, N.Physical geology of high level magmatic systems.Geological Society of London, SP 234, 262p.Mantle, Europe, PolandBook - magmatism, laccoliths, sills
DS2003-0345
2003
Brietsprecher, K.Dostal, J., Brietsprecher, K., Church, B.N., Thorkelson, D., Hamilton, T.S.Eocene melting of Precambrian lithospheric mantle: analcime bearing volcanic rocksJournal of Volcanology and Geothermal Research, Vol. 126, 3-4, Aug. 20, pp. 303-326.British ColumbiaMetasomatism
DS200412-0471
2003
Brietsprecher, K.Dostal, J., Brietsprecher, K., Church, B.N., Thorkelson, D., Hamilton, T.S.Eocene melting of Precambrian lithospheric mantle: analcime bearing volcanic rocks from the Challis Kam loops belt of south centrJournal of Volcanology and Geothermal Research, Vol. 126, 3-4, Aug. 20, pp. 303-326.Canada, British ColumbiaMetasomatism
DS200512-1086
2004
Brietsprecher, K.Thorkelson, D.J., Brietsprecher, K.Partial melting of slab window margins: genesis of adakitic and non-adalitic magmas.Lithos, Vol. 79, pp. 25-41.MantleSubduction, magmatism, dynamic melting
DS2003-0159
2003
Brigadier Gold LimitedBrigadier Gold LimitedAnnounces major expansion.... Kirkland Lake Larder Lake diamond projectBrigadier Gold Ltd., January, 6p.OntarioPress release
DS1993-0163
1993
Brigatti, M.F.Brigatti, M.F., Contini, S., Capedri, S., Poppi, L.Crystal chemistry and cation ordering in pseudobrookite and armalcolite from Spanish lamproitesEuropean Journal of Mineralogy, Vol. 5, pp. 73-84GlobalLamproites, Geochemistry
DS1996-0175
1996
Brigatti, M.F.Brigatti, M.F., Medici, L., Saccani, E., Vaccaro, C.Crystal chemistry and petrologic significance of iron rich phlogopite From the Tapira carbonatite complex.American Mineralogist, Vol. 81, July-Aug. pp. 913-927.BrazilCarbonatite, Deposit -Tapira
DS2001-0133
2001
Brigatti, M.F.Brigatti, M.F., Medici, L., Poppi, VaccaroCrystal chemistry of trioctahedral micas 1M from the Alto Paranaiba igneous provinceCanadian Mineralogist, Vol. 39, No. 5, Oct. pp. 1333-46.BrazilAlkaline rocks, Carbonatite
DS200412-0207
2004
Brigatti, M.R.Brigatti, M.R., Malferrari, D., Medici, L., Ottolini, L., Poppi, L.Crystal chemistry of apatites from the Tapira carbonatite complex, Brazil.European Journal of Mineralogy, Vol. 16, 4,pp. 677-685.South America, BrazilMineral chemistry
DS1985-0085
1985
Brigaud, F.Brigaud, F., Lucazeau, F., Ly, S., Sauvage, J.F.Heat Flow from the West African ShieldGeophysical Research. LETTERS, Vol. 12, No. 9, SEPTEMBER PP. 549-552.West AfricaBlank
DS201807-1507
2018
Briggs, R.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.
DS201904-0719
2019
Briggs, R.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.
DS1983-0149
1983
Briggs, R.P.Briggs, R.P.Comment and Reply on "concentrically Zoned Pattern in the Bouguer Gravity Anomaly Map of Northeastern North America".Geology, Vol. 11, No. 5, P. 318.GlobalMid-continent
DS1992-0163
1992
Briggs, W.Briggs, W., Foster, C.T.Pressure-temperature conditions of Early Proterozoic metamorphism During the Trans-Hudson Orogen as determined rocks straddling the Flin Flon-KisseynewboundaryCanadian Journal of Earth Sciences, Vol. 29, No. 11, November, pp. 2497-2507ManitobaMetamorphic terrain, Proterozoic
DS1940-0004
1940
Bright, E.Baumann, G., Bright, E.The Lost Republic. the Biography of a Land SurveyorLondon: Faber And Faber Ltd., 269P.South Africa, Orange Free StateKimberlite
DS1997-0128
1997
Bright, J.H.Bright, J.H.Discovery of ore deposits.... teams, luck..Mining Engineering, Vol. 49, No. 10, Oct. pp. 88, 93GlobalEconomics, discoveries, success, Deposits
DS1995-0004
1995
Brighton-Grette, J.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
DS1996-0675
1996
Brigueu, L.Jakni, B., Dautria, J-M., Liotard, J-M., Brigueu, L.Evidence of the presence of a carbonated mantle beneath Bas-Languedoc:peridotitic xenoliths Grand Magnon...C.r. Academy Of Science Paris., *french, Vol. 323, iia, pp. 33-40.FranceXenoliths, Basanites, Leucito-nephelinites
DS201112-0391
2011
BrilliGuarino, V., Azzone, Brotzu, De Barros, Melluso, L., Morbidelli, Ruberti, Tassinari, BrilliMagmatism and fenitization in the Cretaceous potassium alkaline carbonatitic complex of Ipanema, Sao Paulo State, Brazil.Mineralogy and Petrology, In press available,South America, BrazilCarbonatite
DS201212-0267
2012
Brilli, M.Guarino, V., Guitarrari Azzone, R., Brotzu, P., Celso de Barros Gomes, Melluso, L., Morbidelli, L.,Ruberti, E.,Tassinari, C., Brilli, M.Magmatism and fenitization in the Cretaceous potassium-alkaline-carbonatitic complex of Ipanema Sao Paulo State, Brazil.Mineralogy and Petrology, Vol. 104, 1-2, pp. 43-61.South America, BrazilCarbonatite
DS201709-1994
2017
Brilli, M.Guarino, V., Wu, F-Y., Melluso, L., de Barros Gomes, C., Tassinari, C.C.G., Ruberti, E., Brilli, M.U Pb ages, geochemistry, C-O-Nd-Sr-Hf isotopes and petrogeneis of the Catalao II carbonatitic complex ( Alto Paranaiba igneous province, Brazil): implucations for regional scale heterogeneities in the Brazilian carbonatite associations.International Journal of Earth Sciences, Vol. 106, 6, pp. 1963-1989.South America, Brazilcarbonatite - Catalao II

Abstract: The Catalão II carbonatitic complex is part of the Alto Paranaíba Igneous Province (APIP), central Brazil, close to the Catalão I complex. Drill-hole sampling and detailed mineralogical and geochemical study point out the existence of ultramafic lamprophyres (phlogopite-picrites), calciocarbonatites, ferrocarbonatites, magnetitites, apatitites, phlogopitites and fenites, most of them of cumulitic origin. U–Pb data have constrained the age of Catalão I carbonatitic complex between 78 ± 1 and 81 ± 4 Ma. The initial strontium, neodymium and hafnium isotopic data of Catalão II (87Sr/86Sri= 0.70503–0.70599; ?Ndi= ?6.8 to ?4.7; 176Hf/177Hf = 0.28248–0.28249; ?Hfi= ?10.33 to ?10.8) are similar to the isotopic composition of the Catalão I complex and fall within the field of APIP kimberlites, kamafugites and phlogopite-picrites, indicating the provenance from an old lithospheric mantle source. Carbon isotopic data for Catalão II carbonatites (?13C = ?6.35 to ?5.68 ‰) confirm the mantle origin of the carbon for these rocks. The origin of Catalão II cumulitic rocks is thought to be caused by differential settling of the heavy phases (magnetite, apatite, pyrochlore and sulphides) in a magma chamber repeatedly filled by carbonatitic/ferrocarbonatitic liquids (s.l.). The Sr–Nd isotopic composition of the Catalão II rocks matches those of APIP rocks and is markedly different from the isotopic features of alkaline-carbonatitic complexes in the southernmost Brazil. The differences are also observed in the lithologies and the magmatic affinity of the igneous rocks found in the two areas, thus demonstrating the existence of regional-scale heterogeneity in the mantle sources underneath the Brazilian platform.
DS1997-0129
1997
Brimhall, G.H.Brimhall, G.H., Gustafson, L.B.Maintaining compatibility of mining and the environmentSociety of Economic Geologist, Publishing 70p. $ 10.00United StatesBook - table of contents, Mining, exploration, industry, economics, discoveries
DS1998-1055
1998
Brimhall, G.H. jr.Murphy, J.B., Oppliger, G.L., Brimhall, G.H. jr.Plume modified orogeny: an example from the western United StatesGeology, Vol. 26, No. 8, Aug. pp. 731-4.CordilleraTectonics, Magmatism
DS1975-0041
1975
Brimmer, A.R.Brimmer, A.R., Franklin, C.D.Commissioning of a Process Control Computer at Consolidated diamond Mines.Journal of MIN. MET. SOC. STH. AFR., Vol. 76, PP. 176-178.South Africa, Southwest Africa, NamibiaDiamond Mining Recovery, Littoral Placers
DS201312-0099
2013
Brin, L.Brin, L.Age and origin of lithospheric mantle beneath central Victoria Island and Darnley Bay.GEM Diamond Workshop Feb. 21-22, Noted onlyCanada, Northwest Territories, Nunavut, Victoria IslandGeochronology
DS201312-0692
2013
Brin, L.Pearson, D.G., Brin, L., Liu, J., Riches, A., Stachel, T., Mather, K.A., Kjarsgaard, B.A.Canada's Arctic cratons: how many, how old, how come?2013 Yellowknife Geoscience Forum Abstracts, p. 49-50.Canada, Northwest Territories, Nunavut, Victoria Island, Parry PeninsulaGeochronology - mantle peridotites
DS201112-0111
2011
Brin, L.E.Brin, L.E., Pearson, D.G., Riches, A.J.V., Miskovic, A., Kjarsgaard, B.A., Kienlen, B., Reford, S.W.Evaluating the northerly extent of the Slave Craton in the Canadian Arctic.Yellowknife Geoscience Forum Abstracts for 2011, Poster abstract p. 95.Canada, Northwest Territories, Nunavut, Victoria Island, Parry PeninsulaKimberlite borne - xenoliths -
DS201809-2060
2018
Brin, L.E.Liu, J., Brin, L.E., Pearson, D.G., Bretschneider, L., Luguet, A., van Acken, D., Kjarsgaard, B., Riches, A., Miskovic, A.Diamondiferous Paleoproterozoic mantle roots beneath Arctic Canada: a study of mantle xenoliths from Parry Peninsula and Central Victoria Island.Geochimica et Cosmochimica Acta, doi.org/10.1016/j.gca.2018.08.010 78p.Canada, Nunavut, Parry Peninsula. Central Victoria Islandxenoliths

Abstract: While the mantle roots directly beneath Archean cratons have been relatively well studied because of their economic importance, much less is known about the genesis, age, composition and thickness of the mantle lithosphere beneath the regions that surround the cratons. Despite this knowledge gap, it is fundamentally important to establish the nature of relationships between this circum-cratonic mantle and that beneath the cratons, including the diamond potential of circum-cratonic regions. Here we present mineral and bulk elemental and isotopic compositions for kimberlite-borne mantle xenoliths from the Parry Peninsula and Central Victoria Island, Arctic Canada. These xenoliths provide key windows into the lithospheric mantle underpinning regions to the North and Northwest of the Archean Slave craton, where the presence of cratonic material has been proposed. The mantle xenolith data are supplemented by mineral concentrate data obtained during diamond exploration. The mineral and whole rock chemistry of peridotites from both localities is indistinguishable from that of typical cratonic mantle lithosphere. The cool mantle paleogeotherms defined by mineral thermobarometry reveal that the lithospheric mantle beneath the Parry Peninsula and Central Victoria Island terranes extended well into the diamond stability field at the time of kimberlite eruption, and this is consistent with the recovery of diamonds from both kimberlite fields. Bulk xenolith Se and Te contents, and highly siderophile element (including Os, Ir, Pt, Pd and Re) abundance systematics, plus corresponding depletion ages derived from Re-Os isotope data suggest that the mantle beneath these parts of Arctic Canada formed in the Paleoproterozoic Era, at ?2?Ga, rather than in the Archean. The presence of a diamondiferous Paleoproterozoic mantle root is part of the growing body of global evidence for diamond generation in mantle roots that stabilized well after the Archean. In the context of regional tectonics, we interpret the highly depleted mantle compositions beneath both studied regions as formed by mantle melting associated with hydrous metasomatism in the major Paleoproterozoic Wopmay-Great Bear-Hottah arc systems. These ?2?Ga arc systems were subsequently accreted along the margin of the Slave craton to form a craton-like thick lithosphere with diamond potential thereby demonstrating the importance of subduction accretion in building up Earth’s long-lived continental terranes.
DS200812-0117
2008
Bringezu, S.Bleischwitz, R., Bringezu, S.Global governance for sustainable resource management.Minerals & Energy - Raw Materials Report, Vol. 28, 2, pp. 84-101.GlobalGovernance
DS1910-0461
1915
Brink, A.Brink, A.Arend Brink on the Establishment of the Diamond Cutting Industry in South Africa: a Seductive But Impractical Proposition.Kimberley: Diamond Fields Advertiser., 24P.South AfricaHistory
DS1960-0127
1961
Brink, A.B.A.Brink, A.B.A.Report and Geochemical Map of Proposed Trunk Route Marientel to Asab, Southwest Africa.Pretoria: Brink Associates, Southwest Africa, NamibiaKimberlite Occurrences, Kimberley
DS1982-0264
1982
Brink, C.Hausel, W.D., Albert, K., Brink, C., Roberts, J.Report on Investigations Related to Prospecting for Diamond bearing Kimberlite and Related Placer Deposits in Wyoming.Wyoming Geological Survey Open File Report, No. 82-1, 48P.United States, Wyoming, State Line, Rocky Mountains, Green River BasinGeochemistry, Prospecting
DS1983-0150
1983
Brink, C.Brink, C., Albert, K.C., Hausel, W.D.Stream Sediment Sampling for Kimberlite in Colorado-wyoming, and Techniques of Diamond Extraction.Wyoming Geological Survey Public Inf. Circular, No. 19, PP. 40-41.United States, State Line, Colorado, WyomingProspecting, Sampling
DS201212-0598
2012
Brink, F.Rosenthal, A., Green, D.H., Kovacs, I., Hibberson, W.O., Yaxley, G.M., Brink, F.Experimental study of the role of water in the uppermost mantle.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractMantleWater
DS201412-0312
2014
Brink, F.Green, D.H., Hibberson, W.O., Rosenthal, A., Kovasc, I., Yaxley, G.M., Falloon, T.J., Brink, F.Experimental study of the influence of water on melting and phase assemblages in the upper mantle.Journal of Petrology, Vol. 55, 10, pp. 2067-2096.MantleMelting
DS202009-1633
2020
Brink, F.Jaques, A.L., Brink, F., Chen, J.Magmatic haggertyite in olivine lamproites of the West Kimberley region, western Australia.The American Mineralogist, in press available, 31p. PdfAustralialamproites
DS202012-2222
2020
Brink, F.Jaques, A.L., Brink, F., Chen, J.Magmatic haggertyite in olivine lamproites of the West Kimberley region, Western Australia.American Mineralogist, Vol. 105, pp. 1724-1733.Australialamproites

Abstract: We report the first occurrence of magmatic haggertyite (BaFe6Ti5MgO19) from the Miocene lamproites of the West Kimberley region of Western Australia. This contrasts with the metasomatic formation reported in an olivine lamproite host at the type locality, Prairie Creek, Arkansas. Haggertyite occurs in the groundmass of a diamondiferous olivine lamproite pipe in the Ellendale field, and within the large zoned Walgidee Hills lamproite where it forms part of an extensive suite of Ba- and K-bearing titanate and Ti-rich silicate minerals. The haggertyite co-exists with chromian spinel, perovskite, and ilmenite in the Ellendale lamproite, and with priderite and perovskite and, in one locality, with priderite, jeppeite, ilmenite, and perovskite, in the Walgidee Hills lamproite. Unlike priderite and perovskite, which are common groundmass phases in the Ellendale olivine lamproites and present throughout the Walgidee Hills lamproite, haggertyite appears restricted in its occurrence and crystallization interval, with sparse ilmenite apparently mostly crystallizing as an alternative phase. In the Walgidee Hills lamproite the haggertyite-bearing assemblage is succeeded by the Ba-titanate assemblage priderite plus jeppeite in the evolved central part of the body. The haggertyite in the main zone of the Walgidee Hills lamproite has an average composition of (Ba0.7K0.3)1.0(Ti5.0Fe3+2.1Cr0.1Fe2+3.8Mn0.2Mg0.6Na0.1)12O19 and is thus very similar to the original haggertyite described from xenoliths in the Prairie Creek lamproite apart from being poorer in Cr and Ni. Haggertyite in the groundmass of the Ellendale olivine lamproite and the central zone of the Walgidee Hills lamproite, in addition to variations in Mg and Cr, show significant variation in Ti and Fe contents and in calculated Fe3+ and Fe2+. A linear inverse relationship between Ti and Fe, and Ti and Fe3+, indicates that Fe3+ is accommodated by the coupled substitution Ti4+ + Fe2+ ? 2 Fe3+. A marked trend to higher Fe3+ in the haggertyite in Ellendale 9 olivine lamproite is ascribed to increasing oxidation during crystallization, with fO2 estimated from the olivine-spinel thermometer and oxygen barometer at Dlog FMQ = -1 to +3 at temperatures of 790-660 °C. The haggertyite in the central zone of the Walgidee Hills lamproite, in contrast, shows a marked trend to Fe2+ enrichment, which is associated with decreasing Fe in perovskite. This is inferred to indicate formation under more reducing conditions, but sufficiently oxidized to permit Fe3+ in co-existing priderite and jeppeite. Trace-element analysis by LA-ICP-MS shows the Walgidee Hills haggertyite contains minor amounts of Na, Si, Ca, V, Co, Zn, Sr, Zr, Nb, and Pb, and only traces of Al, P, Sc, Rb, REE, Hf, and Ta. Moreover, the haggertyite is preferentially enriched in certain lithophile (Ba, Sr), siderophile (Mn, Fe, Co, Ni), and chalcophile (Zn, Pb) elements relative to co-existing priderite. Haggertyite crystallization appears to be a consequence not only of the very high Ba, Ti, and K contents of the lamproite, but of relatively high-Fe concentrations and low temperatures in evolved olivine lamproite magma with the Fe3+/Fe2+ ratio determined by the prevailing fO2. The new data suggest that haggertyite might also be present but previously unrecognized in the evolved groundmass of other olivine lamproites. Haggertyite is one of an increasing number of new minerals in upper mantle rocks and volcanics derived from the upper mantle hosting large-ion-lithophile and high field strength cations.
DS1997-0130
1997
Brink, M.C.Brink, M.C., Waanders, F.B., Bischoff, A.A.Vredefort: a model for the anatomy of an astroblemeTectonophysics, Vol. 270, No. 1, 2, Feb. 28, pp. 83-114.South AfricaAstrobleme, Model
DS1991-0177
1991
Brink, S.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
DS1995-0210
1995
Brinkman, R.Brinkman, R., Lotze, F.Geology of central Europe**IN GERMANSchweizerbart'sche Verlag, Fifth editionEuropeBook -ad
DS1992-0164
1992
Brinsden, W.Brinsden, W.Innovate or perish. Mining and metallurgy conference reportAustralian Institute of Mining and Metallurgy (AusIMM) Bulletin, No. 3, May pp. 13-16GlobalMining, Conference report
DS201112-1026
2011
Brinza, O.Tallaire, A., Barjon, J., Brinza, O., Achard, Silva, Mille, Issaoui, Tardieu, GicquelDislocations and impurities introduced from etch-pitts at the epitaxial growth resumption of diamond.Diamond and Related Materials, Vol. 20, 7, pp. 875-881.TechnologyDiamond morphology
DS201212-0060
2012
Brisbourne, A.M.Bastow, I.D., Kendall, J.M., Brisbourne, A.M., Snyder, D.B., Thompson, D., Hawthorne, D., Hefffrich, G.R., Wookey, J., Horleston, A., Eaton, D.The Hudson Bay lithospheric experiment.Astronomy and Geophysics, pp. 6.21-6.24.Canada, Ontario, QuebecGeophysics - seismics
DS1998-1539
1998
Brisebois, D.Verpaelst, P., Perreault, S., Brisebois, D., BoudriasGeologie de la region de la riviere Koroc, Grand NordQuebec Department of Mines, DV 98-05, p. 35.QuebecGeology
DS201312-0295
2013
Brisson, E.Garapic, G., Faul, U.H., Brisson, E.High resolution imaging of the melt distribution in partially molten upper mantle rocks: evidence for wetted two grain boundaries.Geochemistry, Geophysics, Geosystems: G3, Vol. 14, 3, pp. 556-566.MantleMelting
DS1991-0434
1991
BristowEldridge, C.S., Compston, W., Williams, I.S., Harris, J.W., BristowIsotope evidence for the involvement of recycled sediments in diamondformationNature, Vol. 353, Oct. 17, pp. 649-653GlobalGeochronology - isotopes, Diamond genesis
DS200612-1212
2006
Bristow, C.Sambrook Smith, G., Best, J., Bristow, C., Petts, G.E.Braided rivers.Blackwell Pubisher, 396p. $ 150.00Asia, EuropeBook - geomorphology
DS1993-0113
1993
Bristow, C.S.Best, J.L., Bristow, C.S.Braided riversGeological Society of London Special Publication, No. 75, 420pGermany, Switzerland, Spain, New Zealand, South AfricaBook -table of contents, Sedimentology -braided rivers
DS1994-0210
1994
Bristow, C.S.Bristow, C.S., Best, J.L.Braided rivers: perspectives and problemsBest, and Bristow, Braided Rivers Geological Society of London, No. 75, pp. 1-11.GlobalGeomorphology, Braided rivers
DS1994-0211
1994
Bristow, C.S.Bristow, C.S., Best, J.L.Braided rivers: perspectives and problemsBest, and Bristow, Braided Rivers Geological Society of London, No. 75, pp. 1-11GlobalSedimentology, Geomorphology, Braided rivers
DS2003-0160
2003
Bristow, C.S.Bristow, C.S., Jol., H.M.Ground penetrating radar in sedimentsGeological Society of London Publ., http://bookshop.geolsoc.org.uk, SP 211, 338p. approx. $ 135.USGlobalBook - GPR - general interest
DS2003-0161
2003
Bristow, C.S.Bristow, C.S., Lancaster, N., Duller, G.A.Combining ground penetrating radar and optical dating to determine dune migration inGeological Society of America, Annual Meeting Nov. 2-5, Abstracts p.300.NamibiaGPR, geomorphology
DS200412-0208
2003
Bristow, C.S.Bristow, C.S., Jol, H.M.Ground penetrating radar in sediments.Geological Society of London , SP 211, 338p. approx. $ 135.USTechnologyBook - GPR
DS200412-0209
2003
Bristow, C.S.Bristow, C.S., lancaster, N.,Duller, G.A.Combining ground penetrating radar and optical dating to determine dune migration in Namibia.Geological Society of America, Annual Meeting Nov. 2-5, Abstracts p.300.Africa, NamibiaGPR, geomorphology
DS1993-0164
1993
Bristow, et. al.Bristow, et. al.Symposium - layering in igneous complexes.. field excursion to the BushveldComplexSymposium on Layering in Igneous Complexes, Excurs. Guide, 60pSouth AfricaGuidebook, Deposit -Bushveld Complex
DS1986-0442
1986
Bristow, J.Kinny, P.D., Williams, I.S., Compston, W., Bristow, J.Archean zircon xenocrysts from the Jwaneng kimberlite pipe, BotswanaProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 267-269BotswanaBlank
DS1987-0078
1987
Bristow, J.Bristow, J., Allsopp, H., Skinner, E.M.W.Exciting signatures from the earth's mantleIndiaqua, No. 47, 1987/II, pp. 31-32, 34, 37, 38GlobalIsotope, Geochronology
DS1989-0085
1989
Bristow, J.Barton, E.S., Bristow, J., Hallbauer, D.K.Provenance ages for the Witwatersrand supergroup: constrainst from uranium-lead (U-Pb) (U-Pb)ages of detrital zircons in the Orange Grove quartzite and the VentersdorpcontacTectonics Division and Western Transvaal Branch of the Geological Society South, 1p. (abstract.)South AfricaGeochronology, Witwatersrand research
DS1990-0441
1990
Bristow, J.Eldridge, C.S., Compston, W., Williams, I.S., Bristow, J., HarrisCrustal recycling as recorded in sulfide inclusions from diamonds: a SHRIMP sulfur and lead isotopic studyGeological Society of America (GSA) Annual Meeting, Abstracts, Vol. 22, No. 7, p. A26Southern AfricaDiamond inclusions, SHRIMP geochronology
DS1995-0211
1995
Bristow, J.Bristow, J., Moloi, N., Solomon, M., Rocha, J.Minerals and mining in South Africa: past, present and futureProspectors and Developers Association of Canada (PDAC) Reprint, 8pSouth AfricaEconomics, Mining industry, legal
DS1996-1410
1996
Bristow, J.Taylor, W.R., Bristow, J.Kimberlites, lamproites and alkaline rocksAustralia Nat. University of Diamond Workshop July 29, 30., 6p.GlobalClassification, nomenclature, tectonics, age, Alkaline series summary
DS1996-1544
1996
Bristow, J.Williams, I.S., Eldridge, C.S., Compston, W., Bristow, J.Contributions of SHRIMP micro-isotopic analysis to understanding Kimberlite and diamond genesis.Australia Nat. University of Diamond Workshop July 29, 30., 2p.GlobalDiamond genesis, Geochemistry, mircoprobe, SHRIMP
DS1997-0962
1997
Bristow, J.Rocha, J., Bristow, J.Mine downscaling and closure: an integral part of sustainable developmentJournal of Mineral Policy, Business and Environment, Vol. 12, No. 4, pp. 15-20Ontario, South AfricaEnvironment, closures, Deposit - Sudbury, Kimberley
DS1997-0963
1997
Bristow, J.Rocha, J., Bristow, J.Mine downscaling and closure: an integral part of sustainable developmentJournal of Mineral Policy, Business and Environment, Vol. 12, No. 4, pp. 15-20.South AfricaClosures, downscaling, economics, Deposit - Kimberley area
DS1998-0164
1998
Bristow, J.Bristow, J.Diamonds - industry outlook.. tough trading conditions will persistHuysamer Stals, Analysts report, Feb. 28, 27p.GlobalEconomics - industry outlook, CSO
DS1998-0165
1998
Bristow, J.Bristow, J.India - back to the cradle... polishing industry, kimberlites - newpotential.Abn-ambro, 16p.IndiaBrochure - analysts report, Diamond industry, history, current activity
DS1998-1448
1998
Bristow, J.Taylor, W.R., Bristow, J.Cyclcity of continental alkaline magmatism in the geological record7th International Kimberlite Conference Abstract, pp. 886-7.GlobalAlkaline rocks, Geochronology
DS200712-0109
2007
Bristow, J.Bristow, J., Van Wyk, H., Norton, G., Stevens, G., Oosterveldt, T.Alluvial diamond deposits of the Lower Vaal and Middle Orange Rivers (MOR) and their exploitation. Rockwell Diamonds Inc. promotional presentation.Diamonds in Kimberley Symposium & Trade Show, Bristow and De Wit held August 23-24, Kimberley, South Africa, GSSA Diamond Workshop CD slides 27Africa, South AfricaProjects
DS200812-0142
2008
Bristow, J.Bristow, J.African diamond exploration & development.GSSA-SEG Meeting Held July, Johannesburg, 16 Power point slidesAfricaOverview - brief
DS201602-0194
2016
Bristow, J.Bristow, J.Changes, consolidation and the future of the international diamond business.PDAC 2016, 1p. abstractGlobalDiamond market
DS201607-1334
2016
Bristow, J.Bristow, J.The international diamond business: the role of southern African producers in change and consolidation.IGC 35th., Session Mineral Exploration 1p. AbstractAfrica, South AfricaDiamond markets
DS1980-0075
1980
Bristow, J.W.Bristow, J.W.The Geochronology and Geochemistry of Karoo Volcanics in The Lebombo and Adjacent Areas.Ph.d. Thesis, University Cape Town., South Africa, Botswana, Swaziland, LesothoBasaltic Rocks
DS1980-0121
1980
Bristow, J.W.Erlank, A.J., Allsopp, H.I., Duncan, A.R., Bristow, J.W.Mantle Heterogeneity Beneath Southern Africa: Evidence From a Volcanic Record.Royal Society of London PHIL. Transactions, Vol. 297, No. 1431, PP. 295-308.South AfricaTectonic
DS1982-0122
1982
Bristow, J.W.Bristow, J.W.Geochemistry and Petrogenesis of Lebombo Picrite Basalts ( Southern Africa) and the Role of Mantle MetasomatismGeological Society of America (GSA), Vol. 14, No. 7, P. 452, (abstract.).South AfricaKimberlite, Lherzolite
DS1982-0123
1982
Bristow, J.W.Bristow, J.W.The Current Status of Diamond Exploration in the UsaCalifornia Mining Journal, Vol. No. PP. 60-69.United StatesKimberlite, Diamond
DS1983-0151
1983
Bristow, J.W.Bristow, J.W.Diamond Exploration-usaIndiaqua., No. 34, 1983/1, PP. 27-32.United States, Gulf Coast, Arkansas, Colorado, Wyoming, State Line, Rocky MountainsTravelogue
DS1983-0152
1983
Bristow, J.W.Bristow, J.W., Saggerson, E.P.A General Account of Karoo Vulcanicity in Southern AfricaGeologische Rundschau, Vol. 72, No. 3, PP. 1015-1060.South Africa, Botswana, Lesotho, Swaziland, Mozambique, ZimbabweRegional Geology
DS1985-0006
1985
Bristow, J.W.Allsopp, H.L., Bristow, J.W., Skinner, E.M.W., Scott Smith.Rbsr Geochronology of Some Miocene West Australian LamproitesTransactions Geological Society of South Africa, Vol. 88, pt. 2, May-August pp. 341-345AustraliaLamproite, Geochronology
DS1985-0008
1985
Bristow, J.W.Allsopp, J.W., Bristow, J.W., Skinner, E.M.W.The Rubidium-Strontium geochronology of the Colossus kimberlite pipe,ZimbabweTransactions Geological Society of South Africa, Vol. 88, pt. 2, May-August pp. 245-248ZimbabweGeochronology, Kimberlites
DS1985-0086
1985
Bristow, J.W.Bristow, J.W.Alkaline and Alkaline Ultramafic Rocks and their XenolithsTransactions Geological Society of South Africa, Vol. 88, No. 2, seperate references enteredGlobalBlank
DS1985-0621
1985
Bristow, J.W.Skinner, E.M.W., Smith, C.B., Bristow, J.W., Scott smith, B.H., Dawson.Proterozoic kimberlites and lamproites and a preliminary age for the Argyle lamproite pipe, western AustraliaTransactions Geological Society of South Africa, Vol. 88, pt. 2, May-August pp. 335-340AustraliaLamproite
DS1986-0016
1986
Bristow, J.W.Allsopp, H.L., Smith, C.B., Bristow, J.W., Brown, R., Kramers, J.D.A review of radiometric dating methods applicable to kimberlites And related rocksProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 109-111South AfricaGeochronology
DS1986-0110
1986
Bristow, J.W.Bristow, J.W., Smithm, C.B., Allsopp, H.L., Shee, S.R., SkinnerSetting, geochronology and geochemical characteristics of 160 my kimberlites and related rocks from the Kuruman Province, SouthAfricaProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 112-114South AfricaGeochronology
DS1986-0730
1986
Bristow, J.W.Shee, S.R., Bristow, J.W., Shee, P.B.S., Bell, D.R.The petrology of kimberlites, related rocks and associated mantle xenoliths from the Kuruman province, South Africa #1Proceedings of the Fourth International Kimberlite Conference, Held, No. 16, pp. 90-92South AfricaPetrology
DS1988-0084
1988
Bristow, J.W.Bristow, J.W.Synopsis of some major historical events of the Northern CapeGeoBulletin, Vol. 31, No. 1, pp. 35-39South AfricaChronological listing
DS1988-0085
1988
Bristow, J.W.Bristow, J.W.De Beers 100- a special feature. History..GeoBulletin, Vol. 31, No. 1, Spring quarter pp. 24-28South AfricaBlank
DS1988-0086
1988
Bristow, J.W.Bristow, J.W., Shee, S.R.Kuruman kimberlites- the world's oldest known kimberlite intrusionsGeoBulletin, Vol. 31, No. 1, pp. 40-41South AfricaBlank
DS1989-0021
1989
Bristow, J.W.Allsopp, H.L., Bristow, J.W., Smith, C.B., Brown, R., GleadowA summary of radiometric dating methods applicable To kimberlites and realted rocksGeological Society of Australia Inc. Blackwell Scientific Publishing, Special, No. 14, Vol. 1, pp. 343-357Southern AfricaAge emplacement, Radiometric, Geochronolog
DS1989-0185
1989
Bristow, J.W.Brown, R.W., Allsopp, H.L., Bristow, J.W., Smith, C.B.Improved precision of rubidium-strontium (Rb-Sr) dating of kimberliticmicas: an assessment ofa leaching techniqueChemical Geology, Vol. 79, pp. 125-136South AfricaMakganyene Kimberlite, Geochronology
DS1989-0236
1989
Bristow, J.W.Cawthorn, R.G., Bristow, J.W., Groves, D.I.Magnesian ilmenite in picritic basalts from the KarooprovinceSouthAfricaMineralogical Magazine, Vol. 53, No. 370, pp. 245-252South AfricaPicrite, Ilmenite
DS1989-0276
1989
Bristow, J.W.Colgan, E.A., Clark, T.C., Bristow, J.W., Allsopp, H.Geological setting, petrography and petrogenesis of olivine melilitites Of the Natal coast, South AfricaGeological Society of Australia Inc. Blackwell Scientific Publishing, Special, No. 14, Vol. 1, pp. 419-435South AfricaMelilitite, Petrology
DS1989-0782
1989
Bristow, J.W.Kinny, P.D., Compston, W., Bristow, J.W., Williams, I.S.Archean mantle xenocrysts in a Permian kimberlite: two generations Of kimberlitic zircon in Jwaneng DK2,southern BotswanaGeological Society of Australia Inc. Blackwell Scientific Publishing, Special, No. 14, Vol. 2, pp. 833-842BotswanaMantle xenoliths, Geochronology
DS1989-1284
1989
Bristow, J.W.Robey, J.V.A., Bristow, J.W., Marx, M.R., Joyce, J., Danchin, R.V.Alkaline ultrabasic dikes near Norseman, western AustraliaGeological Society of Australia Inc. Blackwell Scientific Publishing, Special, No. 14, Vol. 1, pp. 382-391AustraliaGeochronology, Lamprophyre
DS1989-1379
1989
Bristow, J.W.Shee, S.R., Bristow, J.W., Bell, D.R., Smith, C.B., Allsopp, H.L.The petrology of kimberlites, related rocks and associated mantle xenoliths from the Kuruman province, South Africa #2Geological Society of Australia Inc. Blackwell Scientific Publishing, No. 14, Vol. 1, pp. 60-82South AfricaMantle, Petrology
DS1991-0284
1991
Bristow, J.W.Compston, W., Williams, I.S., Kinny, P.D., Bristow, J.W., HarrisA SHRIMP ion microprobe investigation into the timing, sources and processes involved in diamond formationGeological Society of America Annual Meeting Abstract Volume, Vol. 23, No. 5, San Diego, p. A 102South AfricaMicroprobe, Diamond morphology
DS1991-1396
1991
Bristow, J.W.Ramos, Z., Skinner, E.M.W., Bristow, J.W., Robinson, D.N.Kimberlites and the mantle in South AfricaXiii International Gemmological Conference Held South Africa, Stellenbosch, 2p.abstractSouth AfricaMantle, Diamond genesis
DS1994-1627
1994
Bristow, J.W.Smith, C.B., Clark, T.C., Barton, E.S., Bristow, J.W.Emplacement ages of kimberlite occurrences in the Prieska region, southwest border of the Kaapvaal Craton, South Africa.Chemical Geology, Vol. 113, No. 1-2, March 1, pp. 149-169.South AfricaGeochronology, Emplacement ages, Prieska area
DS1995-0212
1995
Bristow, J.W.Bristow, J.W.The Proterozoic: its role in diamond petrogenesis and the emplacement of mantle derived intrusives.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 69-70.GlobalProterozoic, Diamond genesis
DS1995-0213
1995
Bristow, J.W.Bristow, J.W.Diamondiferous intrusives and diamonds in Proterozoic settings:implications for exploration.Prospectors and Developers Association of Canada (PDAC) Preprint, 4p.GlobalProterozoic, Off-craton settings
DS1996-0176
1996
Bristow, J.W.Bristow, J.W.Angola: untapped mineral wealth and mine fieldsProspectors and Developers Association of Canada (PDAC) Annual Meeting, p. 67. abstract.AngolaOverview, Political, legal, resources
DS1998-0321
1998
Bristow, J.W.De Meillon, L., Bristow, J.W.Some characteristics of high level Tertiary age alluvial terraces along the Orange River ..7th International Kimberlite Conference Abstract, pp. 193-4.South Africa, Northern Cape ProvinceAlluvials, Deposit - Douglas area
DS201412-0073
2014
Bristow, J.W.Bristow, J.W., De Meillon, L.The Middle Orange River diamond sink.GSSA Kimberley Diamond Symposium and Trade Show provisional programme, Sept. 11, title onlyAfrica, South AfricaMiddle Orange River
DS1986-0672
1986
Bristowm J.W., Marxm M.R.Robey, J.V.A., Bristowm J.W., Marxm M.R., Joyce, J., Danchin, R.V.Alkalic ultrabasic dykes of the southeast Yilgarn margin,WesternAustraliaProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 142-144AustraliaBlank
DS1981-0005
1981
Bristown, J.W.Allsop, H.L., Bristown, J.W., Manton, W.I., Cleverly, R.W.Rubidium-strontium Geochronology of the Lebombo VolcanicsGeocongress '81, South African Geodynamics Project., ABSTRACT VOLUME, PP. 1-2.GlobalDokolwayo, Lembo Volcanics
DS1985-0087
1985
British Columbia Ministry of EnergyBritish Columbia Ministry of Energy, Mines and Petroleum ResourcesHugo Claims/British Columbia Min. Mines, P. 126.Canada, British Columbia, Golden Mining DistrictGeochemistry, Diatreme
DS1992-0165
1992
British Columbia Ministry of EnergyBritish Columbia Ministry of Energy, Mines and Petroleum ResourcesReforming environmental assessment in British Columbia: a legislation discussion paperBritish Columbia Ministry of Energy Mines and Petroleum Resources, 40pBritish ColumbiaMineral exploration, legal, Environmental assessment
DS1992-0166
1992
British Columbia Ministry of EnergyBritish Columbia Ministry of Energy, Mines and Petroleum ResourcesGuidelines for mineral exploration: environmental, reclamation and approvalrequirementsBritish Columbia Ministry of Energy Mines and Petroleum Resources, January 1992, 57pBritish ColumbiaMineral exploration, legal, Guidelines
DS1989-0176
1989
British Columbia ReportBritish Columbia ReportDraft acid rain drainage technical guide, Volume 1 British Columbia acidmine drainage task force reportBritish Columbia Report, 260p. $ 16.00British ColumbiaAcid rain, Drainage report
DS1985-0088
1985
British Geological SurveyBritish Geological SurveyWorld Mineral Statistics 1979-1983. Production: Exports:importsBritish Geological Survey, 150P. DIAMONDS P. 61.GlobalDiamond Production Statistics
DS1991-0178
1991
British Geological SurveyBritish Geological SurveyWorld mineral statistics 1985-1989. Published 1991 -issued 1992British Geological Survey, World Mineral Statistics, pp. 82-87GlobalDiamonds, Production, exports, imports
DS1996-0177
1996
British Geological SurveyBritish Geological SurveyWorld Mineral statistics.. diamondBritish Geological Survey World Mineral Statistics 1990-94, pp. 77-83.GlobalDiamond production, Diamond exports
DS1940-0203
1949
British Guiana Geological SurveyBritish Guiana Geological SurveyThe Geology of the Aurora District Cuyuni River.. Sheet No. D 4Geological Survey British Guiana, Bulletin. No. 21, pp. 23-4, map.GlobalDukwarri Area
DS200912-0387
2009
BritoKlein, E.L., Luzardo, R., Moura, Lobato, Brito, ArmstrongGeochronology, Nd isotopes and reconnaissance geochemistry of volcanic and metavolcanic rocks of Sao Luis Craton, northern Brazil: tectonics and crustalJournal of South American Earth Sciences, Vol. 27, 2-3, pp. 129-145.South America, BrazilGeochronology
DS1999-0094
1999
Brito, D.Brito, D., Aurnou, J., Olson, P.Can heterogeneous core mantle electromagnetic coupling control geomagneticreversals?Physical Earth and Planetary Interiors, Vol. 112, No. 3-4, Apr. 16, pp. 159-170.MantleGeomagnetics, tectonics, structure, torque
DS200412-0210
2004
Brito, D.Brito, D., Aurnou, J., Cardin, P.Turbulent viscosity measurements relevant to planetary core mantle dynamics.Physics of the Earth and Planetary Interiors, Vol. 141,1, pp.3-8.MantleGeophysics - seismics
DS2003-0429
2003
Brito Neves, B.Fuck, Reinhardt, A., Brito Neves, B., Schobbenhaus Filo, C.Search for Rodinia in South America: geological records and problemsGeological Society of America, Annual Meeting Nov. 2-5, Abstracts p.301.BrazilTectonics
DS200412-0589
2003
Brito Neves, B.Fuck, Reinhardt, A., Brito Neves, B., Schobbenhaus Filo, C.Search for Rodinia in South America: geological records and problems.Geological Society of America, Annual Meeting Nov. 2-5, Abstracts p.301.South America, BrazilTectonics
DS1992-0167
1992
Brito Neves, B.B.Brito Neves, B.B.The middle Proterozoic of Brasil: an overview of the knowledge andproblems.(in Portugese).Revista Brasileira de Geociencas, (in Portugese)., Vol. 22, No. 4, Dec. pp. 449-461BrazilProterozoic, Overview
DS2000-0403
2000
Brito Neves, B.B.Heilbron, M., Brito Neves, B.B., Pimentel, M.M., et al.Neoproterozoic orogenic systems in eastern, central and northeastern Brasil,and evolution of Gondwana.Igc 30th. Brasil, Aug. abstract only 1p.Brazil, West AfricaTectonics - Craton, orogeny
DS2003-0281
2003
Brito Neves, B.B.Cordiani, U.G., D'Agrella Filho, M.S., Brito Neves, B.B., Trindada, R.I.Tearing up Rodinia: the Neoproterozoic paleogeorgraphy of South American cratonicTerra Nova, Vol. 15, 5, pp. 350-359.South America, Rodinia, GondwanaTectonics, craton
DS200412-0364
2003
Brito Neves, B.B.Cordiani, U.G., D'Agrella Filho, M.S., Brito Neves, B.B., Trindada, R.I.Tearing up Rodinia: the Neoproterozoic paleogeorgraphy of South American cratonic fragments.Terra Nova, Vol. 15, 5, pp. 350-359.South America, Rodinia, GondwanaTectonics, craton
DS200612-1438
2006
Brito Neves, B.B.Trindade, R.I.F., D'Agrella-Filho, M.S., Epof, I., Brito Neves, B.B.Paleomagnetism of Early Cambrian Itabaiana mafic dikes ( NE Brazil) and the final assembly of Gondwana.Earth and Planetary Science Letters, Vol. 244, 1-2, Apr. 15, pp. 361-377.South America, BrazilDike swarms
DS1998-0166
1998
Brito Neves, B.B.D.Brito Neves, B.B.D., De Almeida, F.F.M., Carneiro, C.D.Origin and evolution of the South American PlatformJournal of African Earth Sciences, Vol. 27, 1A, p. 37. AbstractBrazilGondwana, Tectonics
DS1998-0279
1998
Brito-Neves, B.B.D.Coutinho, J.M.V., Brito-Neves, B.B.D.Questions of the southern portion of Brasil/Africa correlationJournal of African Earth Sciences, Vol. 27, 1A, p. 221. AbstractBrazil, AfricaTectonics
DS1900-0293
1905
Britsih AssociationBritsih AssociationDe Beers Consolidated Mines and the Winning of the DiamondsBritish Association Sth. Afr. Meeting Kimberley Handbook, PP. 42-52.Africa, South AfricaMining, Methods, Recovery, Kimberley
DS1900-0295
1905
Britsih AssociationBritsih AssociationSightseeing in KimberleyBritish Association Sth. Afr. Kimberley Meeting, Publishing By The Dia, 60P.South Africa, Cape Province, Kimberley AreaTravelogue, Kimberley
DS201212-0656
2012
Britto, R.S.Silveira, F.V., Britto, R.S., Matos, L., Araujo, D.P.Diamante Brasil project.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractSouth America, BrazilDeposit - Coromandel, Diamantina
DS202004-0504
2020
Britvich, G.I.Chernykh, S.V., Chernykh, A.V., Tarelkin, S., Didenko, S. ,Kondakov, M.N., Shcherbachev, K.D., Trifonova, E.V., Drozdova, T.E., Troschiev, S.Y., Prikhodko, D.D., Glybin, Y.N., Chubenko, A.P., Britvich, G.I., Kiselev, D.A., Polushin, N.I., Rabinovich, O.IHPHT single crystal diamond type IIa characterization for particle detectors.Physicsa Status Solidi , doi:10.1002/pssa.201900888GlobalHPHT

Abstract: Various samples of multisectoral high?pressure high?temperature (HPHT) single?crystal diamond plate (IIa type) (4?×?4?×?0.53?mm) are tested for particle detection applications. The samples are investigated by X?ray diffractometry, photoluminescence spectroscopy, Raman spectroscopy, Fourier?transform infrared, and visible/ultraviolet (UV) absorption spectroscopy. High crystalline perfection and low impurity concentration (in the {100} growth sector) are observed. To investigate detector parameters, circular 1.0 and 1.5?mm diameter Pt Schottky barrier contacts are created on {111} and {100} growth sectors. On the backside, a Pt contact (3.5?×?3.5?mm) is produced. The {100} growth sector is proved to be a high?quality detector: the full width at half maximum energy resolution is 0.94% for the 5.489?MeV 226Ra ??line at an operational bias of +500?V. Therefore, it is concluded that the HPHT material {100} growth sector is used for radiation detector production, whose quality is not worse than the chemical vapor deposition method or specially selected natural diamond detectors.
DS201112-0812
2011
BritvinPolyakova, E.A., Chakhmouradian, A.R., Siidra ,Britvin, Petrov, Spratt, Williams, Stanley, ZaitsevFluorine, yttrium and lanthanide rich cerianite from carbonatitic rocks of the Kerimasi volcano and surrounding explosion craters, Gregory Rift.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterAfrica, TanzaniaCarbonatite
DS201201-0861
2011
BritvinZaitsev, A.N., Chakmouradian, A.R., Sidra, O.I., Spratt, J., Williams, Stanley, Petrov, Britvin, PolyakaFlourine , yttrium and lanthaide rich cerianite (Ce) from carbonatitic rocks of the Kerimasi volcano and surrounding explosive craters Gregory Rift Tanzania.Mineralogical Magazine, Vol. 75, 6, pp. 2813-2822.Africa, TanzaniaCarbonatite
DS202111-1759
2021
Britvin, S.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.
DS202201-0039
2021
Britvin, S.Sharygin, V.V., Britvin, S., Kaminsky, F.V., Wirth, R.Ellinaite, CaCr204, a new natural post-spinel oxide from Hatrurim Basin, Israel, and Juina kimberlite field, Brazil.European Journal of Mineralogy, Dec.Europe, Israel, South America, Brazildeposit - Juina

Abstract: Ellinaite, a natural analog of the post-spinel phase ?-CaCr2O4, was discovered at the Hatrurim Basin, Hatrurim pyrometamorphic formation (the Mottled Zone), Israel, and in an inclusion within the super-deep diamond collected at the placer of the Sorriso River, Juína kimberlite field, Brazil. Ellinaite at the Hatrurim Basin is confined to a reduced rankinite-gehlenite paralava, where it occurs as subhedral grains up to 30?µm in association with gehlenite, rankinite and pyrrhotite or forms the rims overgrowing zoned chromite-magnesiochromite. The empirical formula of the Hatrurim sample is (Ca0.960FeNa0.012Mg0.003)0.992(Cr1.731VTiAl0.023TiO4. The mineral crystallizes in the orthorhombic system, space group Pnma, unit-cell parameters refined from X-ray single-crystal data: a 8.868(9), b 2.885(3), c 10.355(11)?Å, V 264.9(5)?Å3 and Z=4. The crystal structure of ellinaite from the Hatrurim Basin has been solved and refined to R1=0.0588 based on 388 independent observed reflections. Ellinaite in the Juína diamond occurs within the micron-sized polyphase inclusion in association with ferropericlase, magnesioferrite, orthorhombic MgCr2O4, unidentified iron carbide and graphite. Its empirical formula is Ca1.07(Cr1.71FeV0.06Ti0.03Al0.03Mg0.02Mn0.02)?1.93O4. The unit-cell parameters obtained from HRTEM data are as follows: space group Pnma, a 9.017, b 2.874?Å, c 10.170?Å, V 263.55?Å3, Z=4. Ellinaite belongs to a group of natural tunnel-structured oxides of the general formula AB2O4, the so-called post-spinel minerals: marokite CaMn2O4, xieite FeCr2O4, harmunite CaFe2O4, wernerkrauseite CaFeMn4+O6, chenmingite FeCr2O4, maohokite MgFe2O4 and tschaunerite Fe(FeTi)O4. The mineral from both occurrences seems to be crystallized under highly reduced conditions at high temperatures (>1000??C), but under different pressure: near-surface (Hatrurim Basin) and lower mantle (Juína diamond).
DS201012-0883
2010
Britvin, S.N.Zaitsev, N., Williams, C.T., Britvin,S.N., Kuznetsova, I.V., Spratt, J., Petrov, S.V., Keller, J.Kerimasite Ca3ZR2(Si)O12, a new garnet from carbonatites of Kerimasi volcano and surrounding explosion craters, northern Tanzania.Mineralogical Magazine, Vol. 74, pp. 803-820.Africa, TanzaniaCarbonatite
DS201112-0112
2011
Britvin, S.N.Britvin, S.N., Zaitsev, A.N.Layered sodium manganese phosphate from carbonatite lavas of Oldoinyo Lengai, Gregory Rift, Tanzania.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterAfrica, TanzaniaCarbonatite
DS201609-1729
2016
Britvin, S.N.Lykova, I.S., Pekov, I.V., Chukanov, N.V., Belakovskiy, D.I., Yapaskurt, V.O., Zubkova, N.V., Britvin, S.N., Giester, G.Calciomurmanite a new mineral from the Lovozero and Khibiny alkaline complexes, Kola Peninsula.European Journal of Minerlogy, in press avaialbe 15p.RussiaMineralogy
DS201706-1112
2017
Britvin, S.N.Zaitsev, A.N., Britvin, S.N., Kearsley, A., Wenzel, T., Kirk, C.Jorgkellerite, a new layered phosphate-carbonate mineral from Oldoinyo Lengai volcano, Gregory rift, northern Tanzania.Mineralogy and Petrology, Vol. 111, 3, pp. 373-381.Africa, Tanzaniamineralogy

Abstract: Jörgkellerite, ideally Na3Mn3+ 3(PO4)2(CO3)O2•5H2O, is a new layered phosphate-carbonate from the Oldoinyo Lengai volcano in the Gregory Rift (northern Tanzania). The mineral occurs as spherulites, up to 200 ?m in diameter, consisting of plates up to 10 ?m in thickness in shortite-calcite and calcite carbonatites. Jörgkellerite is brown with a vitreous lustre and has a perfect micaceous cleavage on {001}, Mohs hardness is 3. The calculated density is 2.56 g/cm3. Jörgkellerite is uniaxial (-), ? = 1.700(2), ? = 1.625(2) (Na light, 589 nm) with distinct pleochroism: O = dark brown, E = light brown. The empirical formula of the mineral (average of 10 electron microprobe analyses) is (Na2.46K0.28Ca0.08Sr0.04Ba0.02)?2.88(Mn3+ 2.39Fe3+ 0.56)?2.95((PO4)1.95(SiO4)0.05))?2.00(CO3)(O1.84(OH)0.16)?2.00•5H2O. The oxidation state of Mn has been determined by XANES. Jörgkellerite is trigonal, space group P-3, a = 11.201(2) Å, c = 10.969(2) Å, V = 1191.9(7) Å3 and Z = 3. The five strongest powder-diffraction lines [d in Å, (I/I o), (hkl)] are: 10.970 (100) (001), 5.597 (15) (002), 4.993 (8) (111), 2.796 (14) (220) and 2.724 (20) (004). The crystal structure is built up of the layers composed of disordered edge-sharing [MnO6] octahedra. Each fourth Mn site in octahedral layer is vacant that results in appearance of ordered system of hexagonal "holes" occupied by (CO3) groups. The overall composition of the layer can be expressed as [Mn3O8(CO3)]. These manganese-carbonate layers are linked in the third dimension by (PO4) tetrahedra and Na-polyhedra. The origin of jörgkellerite is related to low-temperature oxidative alteration of gregoryite-nyerereite carbonatites.
DS201803-0487
2018
Britvin, S.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
DS201810-2305
2018
Britvin, S.N.Chukanov, N.V., Rastsvetaeva, R.K., Kruszewski, L., Akensov, S.M., Rusakov, V., Britvin, S.N., Vozchikova, S.A.Siudaite, Na8(Mn2+2Na) Ca6Fe3+3Zr3NbSi25O74(OH)2Cl.5H20: a new eudialyte group mineral from the Khibiny alkaline massif, Kola Peninsula.Physics and Chemistry of Minerals, Vol. 45, pp. 745-758.Russia, Kola Peninsulaalkaline

Abstract: The new eudialyte-group mineral siudaite, ideally Na8(Mn2+2Na)Ca6Fe3+3Zr3NbSi25O74(OH)2Cl•5H2O, was discovered in a peralkaline pegmatite situated at the Eveslogchorr Mt., Khibiny alkaline massif, Kola Peninsula, Russia. The associated minerals are aegirine, albite, microcline, nepheline, astrophyllite, and loparite-(Ce). Siudaite forms yellow to brownish-yellow equant anhedral grains up to 1.5 cm across. Its lustre is vitreous, and the streak is white. Cleavage is none observed. The Mohs’ hardness is 4½. Density measured by hydrostatic weighing is 2.96(1) g/cm3. Density calculated using the empirical formula is equal to 2.973 g/cm3. Siudaite is nonpleochroic, optically uniaxial, negative, with ??=?1.635(1) and ??=?1.626(1) (??=?589 nm). The IR spectrum is given. The chemical composition of siudaite is (wt%; electron microprobe, H2O determined by HCN analysis): Na2O 8.40, K2O 0.62, CaO 9.81, La2O3 1.03, Ce2O3 1.62, Pr2O3 0.21, Nd2O3 0.29, MnO 6.45, Fe2O3 4.51. TiO2 0.54, ZrO2 11.67, HfO2 0.29, Nb2O5 2.76, SiO2 47.20, Cl 0.54, H2O 3.5, -O?=?Cl ??0.12, total 99.32. According to Mössbauer spectroscopy data, all iron is trivalent. The empirical formula (based on 24.5 Si atoms pfu, in accordance with structural data) is [Na7.57(H2O)1.43]?9(Mn1.11Na0.88Ce0.31La0.20Nd0.05Pr0.04K0.41)?3(H2O)1.8(C a5.46Mn0.54)?6(Fe3+1.76Mn2+1.19)?2.95Nb0.65(T i0.20Si0.50)?0.71(Zr2.95Hf0.04Ti0.01)?3Si24.00Cl0.47O70(OH)2Cl0.47•1.2H2O. The crystal structure was determined using single-crystal X-ray diffraction data. The new mineral is trigonal, space group R3m, with a?=?14.1885(26) Å, c?=?29.831(7) Å, V?=?5200.8(23) Å3 and Z?=?3. Siudaite is chemically related to georgbarsanovite and is its analogue with Fe3+-dominant M2 site. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 6.38 (60) (-114), 4.29 (55) (-225), 3.389 (47) (131), 3.191 (63) (-228). 2.963 (100) (4-15), 2.843 (99) (-444), 2.577 (49) (3-39). Siudaite is named after the Polish mineralogist and geochemist Rafa? Siuda (b. 1975).
DS201904-0766
2018
Britvin, S.N.Pekov, I.V., Zubkova, N.V., Yapaskurt, V.O., Lykova, I.S., Chukanov, N.V., Belakovskiy, D.I., Britvin, S.N., Turchkova, A.G., Pushcharovsky, D.Y.Alexhomyakovite, K6(Ca2Na) (CO3)5CI.6h2O, a new mineral from the Khibiny alkaline complex, Kola Peninsula, Russia.European Journal of Mineralogy, Vol. 31, pp. 13-143.Russia, Kola Peninsuladeposit - Khibiny

Abstract: The new mineral alexkhomyakovite K6(Ca2Na)(CO3)5Cl?6H2O (IMA2015-013) occurs in a peralkaline pegmatite at Mt. Koashva, Khibiny alkaline complex, Kola peninsula, Russia. It is a hydrothermal mineral associated with villiaumite, natrite, potassic feldspar, pectolite, sodalite, biotite, lamprophyllite, titanite, fluorapatite, wadeite, burbankite, rasvumite, djerfisherite, molybdenite and an incompletely characterized Na-Ca silicate. Alexkhomyakovite occurs as equant grains up to 0.2 mm, veinlets up to 3 cm long and up to 1 mm thick and fine-grained aggregates replacing delhayelite. Alexkhomyakovite is transparent to translucent, colourless, white or grey, with vitreous to greasy lustre. It is brittle, the Mohs hardness is ca. 3. No cleavage was observed, the fracture is uneven. D meas = 2.25(1), D calc = 2.196 g cm?3. Alexkhomyakovite is optically uniaxial (-), ? = 1.543(2), ? = 1.476(2). The infrared spectrum is reported. The chemical composition [wt%, electron microprobe data, CO2 and H2O contents calculated for 5 (CO3) and 6 (H2O) per formula unit (pfu), respectively] is: Na2O 4.09, K2O 35.72, CaO 14.92, MnO 0.01, FeO 0.02, SO3 0.11, Cl 4.32, CO2 28.28, H2O 13.90, -O=Cl -0.98, total 100.39. The empirical formula calculated on the basis of 9 metal cations pfu is K5.90Ca2.07Na1.03(CO3)5(SO4)0.01O0.05Cl0.95?6H2O. The numbers of CO3 groups and H2O molecules are based on structure data. Alexkhomyakovite is hexagonal, P63/mcm, a = 9.2691(2), c = 15.8419(4) Å, V = 1178.72(5) Å3 and Z = 2. The strongest reflections of the powder X-ray diffraction pattern [d Å(I)(hkl)] are: 7.96(27)(002), 3.486(35)(113), 3.011(100)(114), 2.977(32)(211), 2.676(36)(300), 2.626(42)(213, 115), 2.206(26)(311) and 1.982(17)(008). The crystal structure (solved from single-crystal X-ray diffraction data, R = 0.0578) is unique. It is based on (001) heteropolyhedral layers of pentagonal bipyramids (Ca,Na)O5(H2O)2 interconnected via carbonate groups of two types, edge-sharing ones and vertex-sharing ones. Ca and Na are disordered. Ten-fold coordinated K cations centre KO6Cl(H2O)3 polyhedra on either side of the heteropolyhedral layer. A third type of carbonate group and Cl occupy the interlayer. The mineral is named in honour of the outstanding Russian mineralogist Alexander Petrovich Khomyakov (1933-2012).
DS202004-0532
2020
Britvin, S.N.Sharygin, V.V., Britvin, S.N., Kaminsky, F.V., Wirth, R., Nigmatulina, E.N., Yakovlev, G.A., Novoselov, K.A., Murashko, M.N.Ellinaite IMA No. 2019-091 mineral name( gravel of Sorriso creek, Aripuna River).European Journal of Mineralogy, Vol. 32, p. 211.Europe, Israel, South America, Brazil, Mato Grossodiamond inclusion
DS202011-2036
2020
Britvin, S.N.Chukanov, N.V., Aksenov, S.M., Pekov, I.V., Belakovskiy, D.I., Vozchikova, S.A., Britvin, S.N.Sergevanite, new eudialyte group mineral from the Lovozero alkaline massif, Kola Peninsula.The Canadian Mineralogist, Vol. 58, pp. 421-436.Russia, Kola Peninsuladeposit - Lovozero

Abstract: The new eudialyte-group mineral sergevanite, ideally Na15(Ca3Mn3)(Na2Fe)Zr3Si26O72(OH)3•H2O, was discovered in highly agpaitic foyaite from the Karnasurt Mountain, Lovozero alkaline massif, Kola Peninsula, Russia. The associated minerals are microcline, albite, nepheline, arfvedsonite, aegirine, lamprophyllite, fluorapatite, steenstrupine-(Ce), ilmenite, and sphalerite. Sergevanite forms yellow to orange-yellow anhedral grains up to 1.5 mm across and the outer zones of some grains of associated eudialyte. Its luster is vitreous, and the streak is white. No cleavage is observed. The Mohs' hardness is 5. Density measured by equilibration in heavy liquids is 2.90(1) g/cm3. Calculated density is equal to 2.906 g/cm3. Sergevanite is nonpleochroic, optically uniaxial, positive, with ? = 1.604(2) and ? = 1.607(2) (? = 589 nm). The infrared spectrum is given. The chemical composition of sergevanite is (wt.%; electron microprobe, H2O determined by HCN analysis): Na2O 13.69, K2O 1.40, CaO 7.66, La2O3 0.90, Ce2O3 1.41, Pr2O3 0.33, Nd2O3 0.64, Sm2O3 0.14, MnO 4.15, FeO 1.34, TiO2 1.19, ZrO2 10.67, HfO2 0.29, Nb2O5 1.63, SiO2 49.61, SO3 0.77, Cl 0.23, H2O 4.22, -O=Cl -0.05, total 100.22. The empirical formula (based on 25.5 Si atoms pfu, in accordance with structural data) is H14.46Na13.64K0.92Ca4.22Ce0.27La0.17Nd0.12Pr0.06Sm0.02Mn1.81Fe2+0.58Ti0.46Zr2.67Hf0.04Nb0.38Si25.5S0.30Cl0.20O81.35. The crystal structure was determined using single-crystal X-ray diffraction data. The new mineral is trigonal, space group R3, with a = 14.2179(1) Å, c = 30.3492(3) Å, V = 5313.11(7) Å3, and Z = 3. In the structure of sergevanite, Ca and Mn are ordered in the six-membered ring of octahedra (at the sites M11 and M12), and Na dominates over Fe2+ at the M2 site. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 7.12 (70) (110), 5.711 (43) (202), 4.321 (72) (205), 3.806 (39) (033), 3.551 (39) (220, 027), 3.398 (39) (313), 2.978 (95) (?forumla?), 2.855 (100) (404). Sergevanite is named after the Sergevan' River, which is near the discovery locality.
DS202104-0619
2021
Britvin, S.N.Zaitsev, A.N., Spratt, J., Shtukenberg, A.G., Zolotarev, A.A., Britvin, S.N., Petrov, S.V., Kuptsova, A.V., Antonov, A.V.Oscillatory- and sector zoned pyrochlore from carbonatites of the Kerimasi volcano, Gregory rift, Tanzania.Mineralogical Magazine, Vol. Pp. 1-22. pdfAfrica, Tanzaniacarbonatite

Abstract: The Quaternary carbonatite-nephelinite Kerimasi volcano is located within the Gregory rift in northern Tanzania. It is composed of nephelinitic and carbonatitic pyroclastic rocks, tuffs, tuff breccias and pyroclastic breccias, which contain blocks of different plutonic (predominantly ijolite) and volcanic (predominantly nephelinite) rocks including carbonatites. The plutonic and volcanic carbonatites both contain calcite as the major mineral with variable amounts of magnetite or magnesioferrite, apatite and forsterite. Carbonatites also contain accessory baddeleyite, kerimasite, pyrochlore and calzirtite. Zr and Nb minerals are rarely observed in rock samples, though they are abundant in eluvial deposits of carbonatite tuff/pyroclastic breccias in the Loluni and Kisete craters. Pyrochlore, ideally (CaNa)Nb 2 O 6 F, occurs as octahedral and cubo-octahedral crystals up to 300 ?m in size. Compositionally, pyrochlore from Loluni and Kisete differs. The former is enriched in U (up to 19.4 wt.% UO 2 ), light rare earth elements (up to 8.3 wt.% LREE 2 O 3 ) and Zr (up to 14.4 wt.% ZrO 2 ), and the latter contains elevated Ti (up to 7.3 wt.% TiO 2 ). All the crystals investigated were crystalline, including those with high U content ( a = 10.4152(1) Å for Loluni and a = 10.3763(1) Å for Kisete crystals). They have little or no subsolidus alteration nor low-temperature cation exchange ( A -site vacancy up to 1.5% of the site), and are suitable for single-crystal X-ray diffraction analysis ( R 1 = 0.0206 and 0.0290; for all independent reflections for Loluni and Kisete crystals, respectively). Observed variations in the pyrochlore composition, particularly Zr content, from the Loluni and Kisete craters suggest crystallisation from compositionally different carbonatitic melts. The majority of pyrochlore crystals studied exhibit exceptionally well-preserved oscillatory- and sometimes sector-type zoning. The preferential incorporation of smaller and higher charged elements into more geometrically constrained sites on the growing surfaces explains the formation of the sector zoning. The oscillatory zoning can be rationalised by considering convectional instabilities of carbonatite magmas during their emplacement.
DS202109-1496
2021
Britvin, S.N.Zaitsev, A.N., Spratt, J., Shtukenberg, A.G., Zolotarev, A.A., Britvin, S.N., Petrov, S.V., Kuptsova, A.V., Antonov, A.V.Oscillatory- and select-zoned pyrochlore from carbonatites of the Kerimasi volcano, Gregory Rift, Tanzania.Mineralogical Magazine, Vol. 85, 4, pp. 532-553.Africa, Tanzaniadeposit - Kerimasi

Abstract: The Quaternary carbonatite-nephelinite Kerimasi volcano is located within the Gregory rift in northern Tanzania. It is composed of nephelinitic and carbonatitic pyroclastic rocks, tuffs, tuff breccias and pyroclastic breccias, which contain blocks of different plutonic (predominantly ijolite) and volcanic (predominantly nephelinite) rocks including carbonatites. The plutonic and volcanic carbonatites both contain calcite as the major mineral with variable amounts of magnetite or magnesioferrite, apatite and forsterite. Carbonatites also contain accessory baddeleyite, kerimasite, pyrochlore and calzirtite. Zr and Nb minerals are rarely observed in rock samples, though they are abundant in eluvial deposits of carbonatite tuff/pyroclastic breccias in the Loluni and Kisete craters. Pyrochlore, ideally (CaNa)Nb 2 O 6 F, occurs as octahedral and cubo-octahedral crystals up to 300 ?m in size. Compositionally, pyrochlore from Loluni and Kisete differs. The former is enriched in U (up to 19.4 wt.% UO 2 ), light rare earth elements (up to 8.3 wt.% LREE 2 O 3 ) and Zr (up to 14.4 wt.% ZrO 2 ), and the latter contains elevated Ti (up to 7.3 wt.% TiO 2 ). All the crystals investigated were crystalline, including those with high U content ( a = 10.4152(1) Å for Loluni and a = 10.3763(1) Å for Kisete crystals). They have little or no subsolidus alteration nor low-temperature cation exchange ( A -site vacancy up to 1.5% of the site), and are suitable for single-crystal X-ray diffraction analysis ( R 1 = 0.0206 and 0.0290; for all independent reflections for Loluni and Kisete crystals, respectively). Observed variations in the pyrochlore composition, particularly Zr content, from the Loluni and Kisete craters suggest crystallisation from compositionally different carbonatitic melts. The majority of pyrochlore crystals studied exhibit exceptionally well-preserved oscillatory- and sometimes sector-type zoning. The preferential incorporation of smaller and higher charged elements into more geometrically constrained sites on the growing surfaces explains the formation of the sector zoning. The oscillatory zoning can be rationalised by considering convectional instabilities of carbonatite magmas during their emplacement.
DS2003-0162
2003
Brizi, E.Brizi, E., Nazzareni, S., Princivalle, F., et al.Clinopyroxene from mantle related xenocrysts in alkaline basalts from Hannuoba (Contribution to Mineralogy and Petrology, Vol. 145, 5, August, pp. 578-584.ChinaGeothermometry, alkaline rocks
DS200412-0211
2003
Brizi, E.Brizi, E., Nazzareni, S., Princivalle, F., et al.Clinopyroxene from mantle related xenocrysts in alkaline basalts from Hannuoba ( China): augite pigeonite exsolutions and theirContributions to Mineralogy and Petrology, Vol. 145, 5, August, pp. 578-584.ChinaGeothermometry Alkaline rocks
DS2002-0206
2002
Broadbent, G.C.Broadbent, G.C., Andrews, S.J., Kelso, I.J.A decade of new ideas: geology and exploration history of the Century Zn Pb Ag deposit northeastern QueenslandSociety of Economic Geologists Special Publication, No.9,pp.119-40.Australia, QueenslandZinc, lead, silver. stratabound, Deposit - Century
DS1994-0212
1994
Broadfoot, W.Broadfoot, W., et al.Mineral deposits of the Kingdom of SwazilandCmmh Vol. 3, pp. 257-264GlobalMetallogeny, Overview
DS2001-0473
2001
Broadhurst, L.J.Heritage, G.L., Broadhurst, L.J., Birkhead, A.L.The influence of contemporary flow regime on the geomorphology of the Sabie River, South Africa.Geomorphology, Vol. 38, No. 3-4, pp. 197-211.South AfricaAlluvial - river system
DS201912-2803
2019
BroadleyMarty, B., Bekaert, D.V., Broadley, Jaupart, C.Geochemical evidence for high volatile fluxes from the mantle at the end of the Archean. (water, carbon dioxide, nitrogen and halogens)Nature, Vol. 575, pp. 485-488.Mantlemelting, convection

Abstract: The exchange of volatile species—water, carbon dioxide, nitrogen and halogens—between the mantle and the surface of the Earth has been a key driver of environmental changes throughout Earth’s history. Degassing of the mantle requires partial melting and is therefore linked to mantle convection, whose regime and vigour in the Earth’s distant past remain poorly constrained1,2. Here we present direct geochemical constraints on the flux of volatiles from the mantle. Atmospheric xenon has a monoisotopic excess of 129Xe, produced by the decay of extinct 129I. This excess was mainly acquired during Earth’s formation and early evolution3, but mantle degassing has also contributed 129Xe to the atmosphere through geological time. Atmospheric xenon trapped in samples from the Archaean eon shows a slight depletion of 129Xe relative to the modern composition4,5, which tends to disappear in more recent samples5,6. To reconcile this deficit in the Archaean atmosphere by mantle degassing would require the degassing rate of Earth at the end of the Archaean to be at least one order of magnitude higher than today. We demonstrate that such an intense activity could not have occurred within a plate tectonics regime. The most likely scenario is a relatively short (about 300 million years) burst of mantle activity at the end of the Archaean (around 2.5 billion years ago). This lends credence to models advocating a magmatic origin for drastic environmental changes during the Neoarchaean era, such as the Great Oxidation Event.
DS201709-1963
2017
Broadley, M.W.Broadley, M.W., et al.Noble gases in diamond hosted fluid inclusions: sorting the deep from the dregs.Goldschmidt Conference, abstract 1p.Russia, Siberiadeposit, Nyurbinskaya

Abstract: Fluid inclusions trapped during diamond formation provide pristine information into the nature of mantle volatile sources. The majority of diamonds are formed at the base of the lithosphere, which due to its non-convective nature is able to retain geochemical heterogeneities introduced through interactions with the upper and lower mantle, crustal, and subduction related sources. In order to evaluate the origin of diamond forming fluids in the lithosphere, we present noble gas isotopic data from a suite of cubic, coated and cloudy diamond from the Nyurbinskaya Kimberlite, Siberia. Noble gas signatures extracted from fluid inclusions by crushing show two distinct volatile components present within the Siberian lithosphere. Cubic diamonds have average 3 He/4 He of 10 RA, whilst the 3 He/4 He of the coated and cloudy diamonds is the 6 RA. The Ne isotopic data is also different between the diamonds with 20Ne/22Ne in the cubic diamonds (10.7) consistently higher that the coated and cloudy diamonds, which are dominated by an atmospheric component. The 3 He/4 He in fluids trapped in the coated and cloudy diamonds are typical of samples from the lithospheric mantle. Fluids trapped in the cubic diamonds have higher 3 He/4 He than lithospheric and MORB mantle sources, but are similar to values reported from the Siberian Flood Basalts (SFB), which are derived from a lower mantle source. Ne isotopic data from the cubic diamond also suggests these diamonds contain a lower mantle volatile component. Noble gases in diamond hosted fluid inclusions have shown the Siberian lithosphere contains both lihtospheric and lower mantle volatile compponents. The coexistence of lithospheric and lower mantle volatiles within diamonds originating from the same kimberlite indicates the Siberian lithosphere must have had at least two periods of diamond growth from two distinct diamond forming fluids.
DS201810-2299
2018
Broadley, M.W.Broadley, M.W., Barry, P.H., Ballentine, C.J., Taylor, L.A., Burgess, R.End-Permian extinction amplified by plume-induced release of recycled lithospheric volatiles.Nature Geoscience, 10.1038/s41561-018-0215-4 pp. 682-687.Russia, Siberiasubduction

Abstract: Magmatic volatile release to the atmosphere can lead to climatic changes and substantial environmental degradation including the production of acid rain, ocean acidification and ozone depletion, potentially resulting in the collapse of the biosphere. The largest recorded mass extinction in Earth’s history occurred at the end of the Permian, coinciding with the emplacement of the Siberian large igneous province, suggesting that large-scale magmatism is a key driver of global environmental change. However, the source and nature of volatiles in the Siberian large igneous province remain contentious. Here we present halogen compositions of sub-continental lithospheric mantle xenoliths emplaced before and after the eruption of the Siberian flood basalts. We show that the Siberian lithosphere is massively enriched in halogens from the infiltration of subducted seawater-derived volatiles and that a considerable amount (up to 70%) of lithospheric halogens are assimilated into the plume and released to the atmosphere during emplacement. Plume-lithosphere interaction is therefore a key process controlling the volatile content of large igneous provinces and thus the extent of environmental crises, leading to mass extinctions during their emplacement.
DS202005-0744
2020
Broadley, M.W.Labidi, J., Barry, P.H., Bekaert, D.V., Broadley, M.W., Marty, B., Giunta, T., Warr, O., Sherwood Lollar, B., Fischer, T.P., Avice, G., Caracusi, A., Ballentine, C.J., Halldorsson, S.A., Stefansson, A., Kurz, M.D., Kohl, I.E., Young, E.D.Hydrothermal 15N15N abundances constrain the origins of mantle nitrogen.Nature, Vol. 580, 7803 pp. 367-371. Mantlenitrogen

Abstract: Nitrogen is the main constituent of the Earth’s atmosphere, but its provenance in the Earth’s mantle remains uncertain. The relative contribution of primordial nitrogen inherited during the Earth’s accretion versus that subducted from the Earth’s surface is unclear1,2,3,4,5,6. Here we show that the mantle may have retained remnants of such primordial nitrogen. We use the rare 15N15N isotopologue of N2 as a new tracer of air contamination in volcanic gas effusions. By constraining air contamination in gases from Iceland, Eifel (Germany) and Yellowstone (USA), we derive estimates of mantle ?15N (the fractional difference in 15N/14N from air), N2/36Ar and N2/3He. Our results show that negative ?15N values observed in gases, previously regarded as indicating a mantle origin for nitrogen7,8,9,10, in fact represent dominantly air-derived N2 that experienced 15N/14N fractionation in hydrothermal systems. Using two-component mixing models to correct for this effect, the 15N15N data allow extrapolations that characterize mantle endmember ?15N, N2/36Ar and N2/3He values. We show that the Eifel region has slightly increased ?15N and N2/36Ar values relative to estimates for the convective mantle provided by mid-ocean-ridge basalts11, consistent with subducted nitrogen being added to the mantle source. In contrast, we find that whereas the Yellowstone plume has ?15N values substantially greater than that of the convective mantle, resembling surface components12,13,14,15, its N2/36Ar and N2/3He ratios are indistinguishable from those of the convective mantle. This observation raises the possibility that the plume hosts a primordial component. We provide a test of the subduction hypothesis with a two-box model, describing the evolution of mantle and surface nitrogen through geological time. We show that the effect of subduction on the deep nitrogen cycle may be less important than has been suggested by previous investigations. We propose instead that high mid-ocean-ridge basalt and plume ?15N values may both be dominantly primordial features.
DS202102-0174
2021
Broadley, M.W.Barry, P.H., Broadley, M.W.Nitrogen and noble gases reveal a complex history of metasomatism in the Siberian lithospheric mantle.Earth and Planetary Science Letters, Vol. 556, doi.org/10.1016 /j.epsl.2020. 116707 12p. PdfRussianitrogen

Abstract: The Siberian flood basalts (SFB) erupted at the end of the Permian period (?250 Ma) in response to a deep-rooted mantle plume beneath the Siberian Sub-Continental Lithospheric Mantle (SCLM). Plume-lithosphere interaction can lead to significant changes in the structure and chemistry of the SCLM and trigger the release of metasomatic material that was previously stored within the stable craton. Here, we investigate the nature of the Siberian-SCLM (S-SCLM) by measuring nitrogen abundances and isotopes (N) in 11 samples of two petrologically-distinct suites of peridotitic xenoliths recovered from kimberlites which bracket the eruption of the SFB: the 360 Myr old Udachnaya and 160 Myr old Obnazhennaya pipes. Nitrogen isotope (N) values range from -5.85 ± 1.29‰ to +3.94 ± 0.63‰, which encompasses the entire range between depleted Mid-Ocean Ridge Basalt (MORB) mantle (DMM; -5 ± 2‰) and plume-derived (+3 ± 2‰) endmembers. In addition, we present neon (n=7) and argon (n=8) abundance and isotope results for the same two suites of samples. The 20Ne/22Ne and 21Ne/22Ne range from atmospheric-like values of 9.88 up to 11.35 and from 0.0303 to 0.0385, respectively, suggesting an admixture of DMM and plume-derived components. Argon isotopes (40Ar/36Ar) range from 336.7 to 1122 and correlate positively with 40Ar contents. We show that volatile systematics of Siberian xenoliths: (1) exhibit evidence of ancient metasomatic and/or recycled signatures, and (2) show evidence of subsequent plume-like re-fertilization, which we attribute to the emplacement of the SFB. Metasomatic fluids are highly enriched in radiogenic gases and have elevated Br/Cl and I/Cl values, consistent with an ancient subducted crustal component. The metasomatic component is marked by light N isotope signatures, suggesting it may be derived from an anoxic Archean subducted source. Taken together, these N2-Ne-Ar isotope results suggest that mantle plume impingement has profoundly modified the S-SCLM, and that N, Ne and Ar isotopes are sensitive tracers of metasomatism in the S-SCLM. Metasomatic fluids that permeate the S-SCLM act to archive a “subduction-fingerprint” that can be used to probe relative volatile-element recycling efficiencies and thus provide insight into volatile transport between the surface and mantle reservoirs over Earth history.
DS202107-1091
2021
Broadley, M.W.Bekaert, D.V., Turner, S.J., Broadley, M.W., Barnes, J.D., Halldorsson, S.A., Labidi, J., Wade, J., Walowski, K.J., Barry, P.H.Subduction-driven volatile recycling: a global mass balance.Annual Review of Earth and Planetary Sciences, Vol. 49, pp. 37-70.Mantlesubduction

Abstract: Volatile elements (water, carbon, nitrogen, sulfur, halogens, and noble gases) played an essential role in the secular evolution of the solid Earth and emergence of life. Here we provide an overview of Earth's volatile inventories and describe the mechanisms by which volatiles are conveyed between Earth's surface and mantle reservoirs, via subduction and volcanism. Using literature data, we compute volatile concentration and flux estimates for Earth's major volatile reservoirs and provide an internally balanced assessment of modern global volatile recycling. Using a nitrogen isotope box model, we show that recycling of N (and possibly C and S) likely began before 2 Ga and that ingassing fluxes have remained roughly constant since this time. In contrast, our model indicates recycling of H2O(and most likely noble gases) was less efficient in the past. This suggests a decoupling of major volatile species during subduction through time, which we attribute to the evolving thermal regime of subduction zones and the different stabilities of the carrier phases hosting each volatile. This review provides an overview of Earth's volatile inventory and the mechanisms by which volatiles are transferred between Earth reservoirs via subduction. The review frames the current thinking regarding how Earth acquired its original volatile inventory and subsequently evolved through subduction processes and volcanism.
DS200912-0758
2009
Brocher, T.Thurber, C., Zhang, H., Brocher, T., Langenheim, V.Regional three dimensional seismic velocity model of the crust and uppermost mantle of northern California.Journal of Geophysical Research, Vol. 114, B01304.United States, CaliforniaGeophysics - seismics
DS2002-1219
2002
Brocher, T.M.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
Brocher, T.M.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
DS2003-0163
2003
Brocher, T.M.Brocher, T.M., Parsons, T., Trehu, A.M., Snelson, C.M., Fisher, M.A.Seismic evidence for Wide spread serpentinized forearc upper mantle along theGeology, Vol. 31, 3, pp. 267-70.California, Oregon, Washington, CascadiaGeophysics - seismics, Subduction
DS2003-0164
2003
Brocher, T.M.Brocher, T.M., Parsons, T., Trehu, A.M., Snelson, C.M., Fisher, M.A.Seismic evidence for Wide spread serpentinized forearc upper mantle along theGeology, Vol. 31, 3, pp. 267-70.California, OregonGeophysics - seismics
DS2003-0165
2003
Brocher, T.M.Brocher, T.M., Parsons, T., Trehu, A.M., Snelson, C.M., Fisher, M.A.Seismic evidence for Wide spread serpentinized forearc upper mantle along theGeology, Vol. 31, 3, March, pp. 267-270.California, Oregon, CascadesGeophysics - seismics, Subduction, slabs
DS2003-0166
2003
Brocher, T.M.Brocher, T.M., Parsons, T., Trehu, A.M., Snelson, C.M., Fisher, M.A.Seismic evidence for Wide spread serpentinized forearc upper mantle along theGeology, Vol. 31, 3, March pp. 267-70.California, United StatesGeophysics - seismics
DS200412-0212
2003
Brocher, T.M.Brocher, T.M., Parsons, T., Trehu, A.M., Snelson, C.M., Fisher, M.A.Seismic evidence for Wide spread serpentinized forearc upper mantle along the Cascadia margin.Geology, Vol. 31, 3, March pp. 267-70.United States, CaliforniaGeophysics - seismics
DS1960-0454
1964
Brock, A.Gough, D.I., Brock, A.The Paleomagnetism of the Shawa IjoliteJournal of Geophysical Research, Vol. 69, No. 12, PP. 2489-2493.ZimbabweGeology, Related Rocks
DS1960-0455
1964
Brock, A.Gough, D.I., Brock, A.The Paleomagnetism of the Ring Complexes at Marangudzi and The Mateke Hills.Journal of Geophysical Research, Vol. 69, No. 12, PP. 2499-2507.ZimbabweGeology, Related Rocks
DS1930-0185
1935
Brock, C.L.Brock, C.L.Titanium at Magnet Cove, ArkansawRocks And Minerals, Vol. 10, No. 11, NOVEMBER P. 169.United States, Gulf Coast, Arkansas, Hot Spring CountyBlank
DS1960-0558
1965
Brock, M.Heyl, A.V., Brock, M., Jolly, J.L., Wells, G.E.Regional Structure of Southeast Missouri and Illinois- Kentucky Mineral District.United States Geological Survey (USGS) Bulletin., No. 1202-B, 20P.United States, Kentucky, Missouri, Illinois, Central StatesBlank
DS1960-0899
1967
Brock, M.E.Zartman, R.E., Brock, M.E., Heyl, A.V., Thomas, H.H.Potassium-argon and Rubidium-strontium Ages of Some Alkaline Intrusive rocks from Central and Eastern United States.American Journal of Science, VOL 265, PP. 838-870.United States, Appalachia, New York, Central StatesGeology, Related Rocks, Kimberlite, Geochronology
DS1960-0128
1961
Brock, M.R.Brock, M.R., Heyl, A.V.Jr.Post Cambrian Igneous Rocks of the Central Craton, Western Appalachian Mountains and Gulf Coastal Plain of the United States.United States Geological Survey (USGS) PROF. PAPER., No. 424-D, PP. D33-35.United States, Appalachia, New YorkRegional Geology
DS1960-0153
1961
Brock, M.R.Heyl, A.V., Brock, M.R.Structural Framework of the Illinois Kentucky Mining District and its Relation to Mineral Deposits.United States Geological Survey (USGS) PROF. PAPER., No. 424-D, PP. D3-D6.United States, Kentucky, AppalachiaTectonics, Structure, Regional Geology
DS1960-0256
1962
Brock, M.R.Kiilsgaard, T.H., Heyl, A.V., Brock, M.R.The Crooked Creek Disturbance Southeast MissouriUnited States Geological Survey (USGS) PROF. PAPER., No. 450-E, PP. E14-E19.Missouri, United States, Central StatesCryptoexplosion
DS1960-0559
1965
Brock, M.R.Heyl, A.V., Brock, M.R., Jolly, J.L., Wells, C.E.Regional Structure of the Southeast Missouri and Illinois Kentucky Mineral Districts.United States Geological Survey (USGS) Bulletin., No. 1202-B, 20P.GlobalMid Continent
DS1986-0362
1986
Brock, M.R.Heyl, A.V., Brock, M.R., Jolly, J.L.Phanerozoic igneous rocks, including kimberlites of the United States craton west of the Blue Ridge Mountains and east of the Rocky Mountains and their associated7th. IAGOD Symposium abstract volume, Held August 18-22, Lulea Sweden, pp. 407-408. (abstract.)Colorado, New Mexico, Wyoming, Montana, South DakotaBlank
DS1988-0303
1988
Brock, M.R.Heyl, A.V., Brock, M.R., Jolly, J.L.Phanerozoic igneous rocks, including kimberlites of the United States craton west of the Blue Ridge Mtns. &east of the Rocky Mountains and their Association mineral deposI.a.g.o.d., Proceedings Of The Seventh Quadrennial Iagod Symposium, Vol. 7, pp. 103-110Arkansas, Tennessee, Kentucky, Illinois, Appalachia, MidcontinentMontana, South Dakota, Colorado, Wyoming, Tectonics
DS1991-0710
1991
Brock, M.R.Heyl, A.V., Brock, M.R.Mineral deposits related to Proterozoic alkalic igneous rocks of the central part of the United StatesGlobal Tectonics and Metallogeny, Vol. 4, No. 1, 2 September pp. 61-64. extended abstractMissouri, Arkansas, Tennessee, Wyoming, State LineAlkaline rocks, Proterozoic
DS1910-0164
1911
Brock, R.W.Brock, R.W.Diamond Discovery in British ColumbiaOttawa Citizen., MARCH 16TH.Canada, British ColumbiaBlank
DS1910-0165
1911
Brock, R.W.Brock, R.W.Diamonds in British Columbia; May, 1911British Columbia Mining Engineering Rec., Vol. 16, MAY PP. 286-288.Canada, British ColumbiaBlank
DS1996-0178
1996
Brocker, M.Brocker, M., Klemd, R.Ultrahigh pressure metamorphism in the Snieznik Mountains: Sudetes Poland -geological implications.Journal of Geology, Vol. 104, pp. 417-33.GlobalMetamorphism - P-T constraints, Eclogites
DS1996-0179
1996
Brocker, M.Brocker, M., Klemd, R.Ultrahigh pressure metamorphism in the Snieznik Mountains: Sudetes Poland P- T constraints and geological implications.Journal of Geology, Vol. 104, pp. 417-33.Globalmetamorphism, Eclogites
DS200412-0298
2004
Brocker, M.Cenki, B., Braun, I., Brocker, M.Evolution of the continental crust in the Kerala Khondalite belt, southernmost India: evidence from Nd isotope mapping, U Pb andPrecambrian Research, Vol. 134, 3-4, Oct. 22, pp. 275-292.IndiaMetamorphism, Geochronology
DS1990-1130
1990
Brockner, M.Okrusch, M., Brockner, M.Eclogites associated with high-grade blueschists in the CycladesArchipelago, Greece- a reviewEuropean Journal of Mineralogy, Vol. 2, No. 4, pp. 451-478GlobalEclogites, Review
DS200712-0144
2007
BrodCarlson, R.W., Aruajo, Junqueira-Brod, Gaspar, Brod, Petrinovic, Hollanda, Pimentel, SichelChemical and isotopic relationships between peridotite xenoliths and mafic-ultrapotassic rocks from southern Brazil.Chemical Geology, Vol. 242, 3-4, pp. 418-437.South America, BrazilGeochemistry
DS200712-0145
2007
BrodCarlson, R.W., Aruajo, Junqueira-Brod, Gaspar, Brod, Petrinovic, Hollanda, Pimentel, SichelChemical and isotopic relationships between peridotite xenoliths and mafic-ultrapotassic rocks from southern Brazil.Chemical Geology, Vol. 242, 3-4, pp. 418-437.South America, BrazilGeochemistry
DS201112-0256
2011
BrodDe Oliveira Cordeiro, Brod, Palmieri, Gouveia de Oliveira, Soares Rocha Barbosa, Santos, Gaspar, AssisThe Catalao I niobium deposit, central Brazil: resources, geology and pyrochlore chemistry.Ore Geology Reviews, Vol. 41, pp. 112-121.South America, BrazilCarbonatite
DS2001-0134
2001
Brod, J.Brod, J., Gaspar, De Araujo, Gibson, Thompson, JunqueiraPhlogopite and tetra ferriphlogopite from Brazilian carbonatite complexes and implications for systematicsJournal of African Earth Sciences, Vol. 19, No. 3, Apr. pp.265-296.BrazilCarbonatite, Mineral chemistry systematics
DS2000-0109
2000
Brod, J.A.Brod, J.A., Gibson, S.A., Thompson, R., Junqueira-BrodMineral chemistry fingerprints of liquid immiscibility and fractionation in the Tapira alkaline - carbonatiteIgc 30th. Brasil, Aug. abstract only 1p.Brazil, Minas GeraisCarbonatite - Alto Paranaiba Igneous Province
DS2000-0110
2000
Brod, J.A.Brod, J.A., Gibson, S.A., Thompson, R., Junqueira-BrodKamafugite affinity of the Tapira alkaline carbonatite complex (Minas Gerais, Brasil).Igc 30th. Brasil, Aug. abstract only 1p.Brazil, Minas GeraisCarbonatite - Araxa, Serra Negra, Salitre, Catalao, Kamafugites
DS2000-0316
2000
Brod, J.A.Gaspar, J.C., Brod, J.A., Sgarbi, P.B.A., Brod, T.C.J.A review of the Cretaceous alkaline magmatism in western Minas Gerais and southern Goias.Igc 30th. Brasil, Aug. abstract only 1p.Brazil, Minas GeraisAlkaline rocks
DS2003-0167
2003
Brod, J.A.Brod, J.A., Gaspar, J.C., Diniz-Pinto, H.S., Junqueira-Brod, T.C.Spinel chemistry as an indicator of crystal fractionation and liquid immiscibility in the8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, POSTER abstractBrazil, Minas GeraisBlank
DS2003-0168
2003
Brod, J.A.Brod, J.A., Junqueira-Brod, T.C., Gaspar, J.C., Gibson, S.A., Thompson, R.N.Ti rich and Ti poor garnet from the Tapira carbonatite complex, SE Brazil: fingerprinting8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, POSTER abstractBrazil, Minas GeraisBlank
DS2003-0444
2003
Brod, J.A.Gaspar, J.C., Araujo, A.L.N., Carlson, R.W., Sichel, S.E., Brod, J.A., SgarbiMantle xenoliths and new constraints on the origin of alkaline ultrapotassic rocks from8 Ikc Www.venuewest.com/8ikc/program.htm, Session 7, POSTER abstractBrazilBlank
DS2003-0677
2003
Brod, J.A.Junqueira-Brod, T.C., Brod, J.A., Gaspar, J.C., Barbosa, E.S.R.Magma - sediments interaction in the Aguas Emendadas kamafugitic diatremes, GO8ikc, Www.venuewest.com/8ikc/program.htm, Session 1 POSTER abstractBrazil, GoiasKimberlite geology and economics, Deposit - Aguas Emendadas
DS2003-0678
2003
Brod, J.A.Junqueira-Brod, T.C., Gaspar, J.C., Brod, J.A., Barbosa, E.S.R.Magma mixing in Cretaceous kamafugites, Goias alkaline province, Brazil8ikc, Www.venuewest.com/8ikc/program.htm, Session 1 POSTER abstractBrazil, GoiasKimberlite geology and economics
DS200412-0213
2003
Brod, J.A.Brod, J.A., Gaspar, J.C., Diniz-Pinto, H.S., Junqueira-Brod, T.C.Spinel chemistry as an indicator of crystal fractionation and liquid immiscibility in the Tapira alkaline carbonatie complex, Mi8 IKC Program, Session 7, POSTER abstractSouth America, Brazil, Minas GeraisKimberlite petrogenesis
DS200412-0214
2003
Brod, J.A.Brod, J.A., Junqueira-Brod, T.C., Gaspar, J.C., Gibson, S.A., Thompson, R.N.Ti rich and Ti poor garnet from the Tapira carbonatite complex, SE Brazil: fingerprinting fractional crystallization and liquid8 IKC Program, Session 7, POSTER abstractSouth America, Brazil, Minas GeraisKimberlite petrogenesis
DS200412-0612
2003
Brod, J.A.Gaspar, J.C., Araujo, A.L.N., Carlson, R.W., Sichel, S.E., Brod, J.A., Sgarbi, P.B., Danni, J.C.M.Mantle xenoliths and new constraints on the origin of alkaline ultrapotassic rocks from the Alto Paranaiba and Goias igneous pro8 IKC Program, Session 7, POSTER abstractSouth America, BrazilKimberlite petrogenesis
DS200512-0492
2005
Brod, J.A.Junqueira-Brod, T.C., Gaspar, J-C., Brod, J.A., Jost, H., Rocha Barbosa, E.S., Kafino, C.V.Emplacement of kamafugitic lavas from the Goais alkaline province, Brazil: constraints from whole rock simulations. (mafurite, ugandite)Journal of South American Earth Sciences, Vol. 18, 3-4, March pp. 323-335.South America, BrazilSanto Antonio da Barra, Aguas Emendadas, carbonatite
DS200512-0493
2005
Brod, J.A.Junqueira-Brod, T.C., Gaspar, J-C., Brod, J.A., Kafino, C.V.Kamafugitic diatremes: their textures and field relationships with examples from the Goais alkaline province, Brazil.Journal of South American Earth Sciences, Vol. 18, 3-4, March pp. 337-353.South America, BrazilBreccia, lapilli, peperite, surge
DS200512-0902
2005
Brod, J.A.Ribeiro, C.C., Brod, J.A., Junqueira-Brod, T.C., Gaspar, J-C., Petrinovic, I.A.Mineralogical and field aspects of magma fragmentation deposits in a carbonate phosphate magma chamber: evidence from the Catalao I complex, Brazil.Journal of South American Earth Sciences, Vol. 18, 3-4, March pp. 355-369.South America, BrazilCarbonatite, Lagoa Seca, APIP, chamber pipes, surge
DS200812-0077
2008
Brod, J.A.Barbosa, E.S.R., Junqueira-Brod, T.C., Brod, J.A., Dantas, E.L.Petrology of bebdourites from the Salitre phoscorite carbonatite complex, Brazil.9IKC.com, 3p. extended abstractSouth America, BrazilCarbonatite
DS200812-0243
2008
Brod, J.A.Cordiero, P.F.O., Brod, J.A., Santos, R.V.Oxygen and carbon isotopes and carbonate chemistry in phoscorites from the Catalao I complex - implications for phosphate iron oxide magmas.9IKC.com, 3p. extended abstractSouth America, BrazilCarbonatite
DS200812-0840
2008
Brod, J.A.Palmieri, M., Pereira, G.S.B., Brod, J.A., Junquiera-Brod, T.C., Petrinovic, I.A., Ferrari, A.J.D.Orbicular magnetite from the Catalao I phoscorite carbonatite complex.9IKC.com, 3p. extended abstractSouth America, BrazilCarbonatite
DS201012-0124
2010
Brod, J.A.Cordeiro, P.F.O., Brod, J.A., Dantas, E.L., Barbosa, E.S.R.Mineral chemistry, isotope geochemistry and petrogenesis of niobium rich rocks from the Catalao I carbonatite phoscorite complex, central Brazil.Lithos, Vol. 118, pp. 223-237.South America, BrazilCarbonatite
DS201012-0144
2010
Brod, J.A.De Oliveira Cordeiro, P.F., Brod, J.A., Ventura Santos, R., Dantas, E.L., Gouvieia de Oliveira, C., Soares Rocha, Barbosa, E.Stable ( C,O) and radiogenic (Sr, Nd) isotopes of carbonates as indicators of magmatic and post magmatic processes of phoscorite series rocks and carbonatites fContributions to Mineralogy and Petrology, In press available, 14p.South America, BrazilCatalao I
DS201112-0257
2011
Brod, J.A.De Oliveire Cordeiro, P.F., Brod, J.A., Ventura Santos, R., Dantas, E.L., Gouveia de Oliveira, C., Soares Rochas Barbosa, E.Stable (C,O) and radiogenic (Sr,Nd) isotopes of carbonates as indicators of magmatic and post-magmatic processes of phoscorite series rocks and carbonatites from Catalao 1, central Brazil.Contributions to Mineralogy and Petrology, Vol. 161, 3, pp. 451-464.South America, BrazilCarbonatite
DS201212-0053
2012
Brod, J.A.Barbosa, E.S.R., Brod, J.A., Junqueira-Brod, T.C., Cordeiro, P.F.O., Santos, R.V., Dantas, E.L.Phoscorites from the Salitre alkaline complex, Brazil: origin and petrogenetic implications.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractSouth America, BrazilDeposit - Salitre
DS201212-0054
2012
Brod, J.A.Barbosa, E.S.R., Brod, J.A., Junqueira-Brod, T.C., Cordeiro, P.F.O.,Dantas, E.L., Santos, R.V.Mineralogy and petrology of the Salitre 1 phoscorite carbonatite alkaline compelx, Brazil.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractSouth America, BrazilDeposit - Slitre 1
DS201212-0345
2012
Brod, J.A.Kafino, C.V., Brod, J.A., Brod, T.C., Freitas, N.M.Mineral chemistry of mantle xenoliths from Kamafugite diatremes in the Goias alkaline Province, Brazil.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractIndiaDeposit - Goias
DS201212-0681
2012
Brod, J.A.Soares Rocha Barbosa, E., Brod, J.A., Junqueira-Brod, T.C., Dantas, E.L., De Oliveira Cordeiro, P.F., Siqueira Gomide, C.Bebdourite from its type area Sailtre 1 complex: a key petrogenetic series in the Late-Cretaceous Alto Paranaiba kamafugite carbonatite phoscorite association, central Brazil.Lithos, Vol. 146-147, pp. 56-72.South America, BrazilCarbonatite
DS201212-0770
2012
Brod, J.A.Weska, R.K., Brod, J.A., Dantas, E.L., Araujo, D.P.Mineral chemistry of garnets and ilmenites of the Pepper-1 and Cosmos-3 intrusions, Espigao D'Oeste, Rondonia, Brazil.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractSouth America, Brazil, RondoniaDeposit - Pepper, Cosmos
DS201312-0100
2013
Brod, J.A.Brod, J.A., Junqueira-Brod, T.C., Gaspar, J.C., Petrinovic, I.A., De Castro Valente, S., Corval, A.Decoupling of paired elements, crossover REE patterns and mirrored spider diagrams: fingerprinting liquid immiscibility in the Tapira alkaline carbonatite complex, SE Brazil.Journal of South American Earth Sciences, Vol. 41, pp. 41-56.South America, BrazilTapira - mineral chemistry
DS201312-0319
2013
Brod, J.A.Gomide, C.S., Brod, J.A., Junqueira-Brod, T.C., Buhn, B.M., Santos, R.V., Barbosa, E.S.R., Cordeiro, P.F.O., Palmieri, M., Grasso, C.B., Torres, M.G.Sufur isotopes from Brazilian alkaline carbonatite complexes.Chemical Geology, Vol. 341, pp. 38-49.South America, BrazilDeposit - Tapira, Salitre, Serra Negra, Catalao, Jacupiringa
DS201702-0209
2017
Brod, J.A.De Oliveira, I.L., Brod, J.A., Cordeiro, P.F.O., Dantas, E.L., Mancini, L.H.Insights into the Late stage differentiation processes of the Cat alao I Carbonatite complex in Brazil: new Sr-Nd and C-O isotopic dat a in minerals from niobium ores.Lithos, In press available, 44p.South America, BrazilDeposit - Catalao I

Abstract: The Late Cretaceous Catalão I carbonatite complex consists of ultramafic silicate rocks, phoscorites, nelsonites and carbonatites. The latest stages of the evolution of the complex are characterized by several nelsonite (magnetite-apatite rock) and carbonatite dykes, plugs and veins crosscutting earlier alkaline rocks. The interaction between the latter and late-stage carbonatites and/or carbo-hydrothermal fluids, converted the original dunites and bebedourites to metasomatic phlogopitites. Late-stage nelsonites (N1), pseudonelsonites (N2) and various types of dolomite carbonatites (DC) including norsethite-, magnesite- and/or monazite-bearing varieties show significant whole-rock Nd and Sr isotopic variations. To elucidate whether magmatic or metasomatic processes, or both, were responsible for these isotope variations we characterized the Nd and Sr isotope compositions of major mineral phases (i.e. apatite, dolomite, norsethite, pyrochlore and tetraferriphlogopite) in these late-stage rocks. Mineral isotope data recorded the same differences observed between N1 and N2 whole-rocks with N2 minerals showing more enriched isotopic signatures than minerals from N1. Sr isotopic disequilibrium among minerals from N2 pseudonelsonites and spatially related dolomite carbonatite pockets implies formation from batches of carbonate melts with distinct isotopic compositions. A detailed investigation of Nd and Sr isotopes from whole-rocks and minerals suggests that the most evolved rocks of the Catalão I complex probably derive from two different evolution paths. We propose that an earlier magmatic trend (path A) could be explained by several batches of immiscible and/or residual melts derived from carbonated-silicate parental magma (e.g. phlogopite picrite) contaminated with continental crust to a variable extent, in an AFCLI-like process. A second trend (path B) comprises highly variable 143Nd/144Ndi at nearly constant 87Sr/86Sri coupled with high ?18O in carbonates. This is interpreted here as the result of the interaction of previously-formed dolomite carbonatites with carbo-hydrothermal fluids.
DS201212-0345
2012
Brod, T.C.Kafino, C.V., Brod, J.A., Brod, T.C., Freitas, N.M.Mineral chemistry of mantle xenoliths from Kamafugite diatremes in the Goias alkaline Province, Brazil.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractIndiaDeposit - Goias
DS2000-0316
2000
Brod, T.C.J.Gaspar, J.C., Brod, J.A., Sgarbi, P.B.A., Brod, T.C.J.A review of the Cretaceous alkaline magmatism in western Minas Gerais and southern Goias.Igc 30th. Brasil, Aug. abstract only 1p.Brazil, Minas GeraisAlkaline rocks
DS1989-0177
1989
Brodaric, B.Brodaric, B., Fyon, J.A.Ontario Geological Survey (OGS) Fieldlog: a microcomputer based methodology to store, process and display map-related dataOntario Geological Survey Open File, No. 5709, 70pOntarioComputer, Program -Ontario Geological Survey (OGS) FIELDLOG
DS1993-0167
1993
Brodaric, B.Broome, J., Brodaric, B., Viljoen, D., Baril, D.The NATMAP digital geoscience data-management systemComputers and Geosciences, Vol. 19, No. 10, pp. 1501-1516GlobalComputers, Program -NATMAP data management system
DS200612-0173
2006
Brodaric, B.Brodaric, B., Gahegan, M.Representing geoscientific knowledge in cyberinfrastructure: some challenges, approaches and implentatations.In: Sinha, A.K. Geoinformatics: data to knowledge, GSA Special Paper, 397, 397, pp.1-20.TechnologyData - not specific to diamonds
DS200612-0839
2006
Brodaric, B.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
DS201512-1915
2015
Brodaric, B.Ebert, K., Brodaric, B.GIS analyses of ice-sheet erosional impacts on the exposed shield of Baffin Island, eastern Canadian Arctic.Canadian Journal of Earth Sciences, Vol. 52, 11, pp. 966-979.Canada, Nunavut, Baffin IslandGeomorphology

Abstract: The erosional impacts of former ice sheets on the low-relief bedrock surfaces of Northern Hemisphere shields are not well understood. This paper assesses the variable impacts of glacial erosion on a portion of Baffin Island, eastern Canadian Arctic, between 68° and 72°N and 66° and 80°W. This tilted shield block was covered repeatedly by the Laurentide Ice Sheet during the late Cenozoic. The impact of ice-sheet erosion is examined with GIS analyses using two geomorphic parameters: lake density and terrain ruggedness. The resulting patterns generally conform to published data from other remote sensing studies, geological observations, cosmogenic exposure ages, and the distribution of the chemical index of alteration for tills. Lake density and terrain ruggedness are thereby demonstrated to be useful quantitative indicators of variable ice-sheet erosional impacts across Baffin Island. Ice-sheet erosion was most effective in the lower western parts of the lowlands, in a west-east-oriented band at around 350-400 m a.s.l., and in fjord-onset zones in the uplifted eastern region. Above the 350-400 m a.s.l. band and between the fjord-onset zones, ice-sheet erosion was not sufficient to create extensive ice-roughened or streamlined bedrock surfaces. The exception — where lake density and terrain ruggedness indicate that ice-sheet erosion had a scouring effect all across the study area — was in an area from Foxe Basin to Home Bay with elevations <400 m a.s.l. These morphological contrasts link to former ice-sheet basal thermal regimes during the Pleistocene. The zone of low glacial erosion surrounding the cold-based Barnes Ice Cap probably represents the ice cap’s greater extent during successive Pleistocene cold stages. Inter-fjord plateaus with few ice-sheet bedforms remained cold-based throughout multiple Pleistocene glaciations. In contrast, zones of high lake density and high terrain ruggedness are a result of the repeated development of fast-flowing, erosive ice in warm-based zones beneath the Laurentide Ice Sheet. These zones are linked to greater ice thickness over western lowland Baffin Island. However, adjacent lowland surfaces with similar elevations of non-eroded, weakly eroded, and ice-scoured shield bedrock indicate that—even in areas of high lake density and terrain ruggedness—the total depth of ice sheet erosion did not exceed 50 m.
DS201706-1077
2017
Brodaric, B.Harrison, J.C., St. Onge, M.R., Paul, D., Brodaric, B.A new geological map and map database for Canada north of 60.GAC annual meeting, 1p. AbstractCanadamap
DS1860-0061
1868
Broderick, M.Bamang-Wato, Broderick, M.To Ophir DirectLondon: Edward Stanley, E. Standford., 56P. PLUS APPENDIX.Africa, South Africa, ZimbabweTravelogue
DS200912-0515
2009
Broderick, T.Moore, A.E., Cotteril, F.P.D., Broderick, T., Plowes, D.Lands cape evolution in Zimbabwe for the Permian from present with implications for kimberlite prospecting.South Africa Journal of Geology, Vol. 112, 1, pp. 65-88.Africa, ZimbabweGeomorphology
DS1975-0872
1978
Broderick, T.J.Stagman, J.G., Harrison, N.M., Broderick, T.J., Stocklmayer, V.An Outline of the Geology of RhodesiaRhodesia Geological Survey, Bulletin. No. 80, 126P.ZimbabweGeology, Kimberley
DS200612-0174
2006
Brodhag, C.Brodhag, C., Taliere, S.Sustainable development strategies: tools for policy coherence.Natural Resources Forum, Vol. 30, 2, May pp. 136-145.GlobalEnvironment
DS201809-2102
2018
Brodhollt, J.Thomson, A.R., Dobsdon, D.P., Brodhollt, J., Crichton, W., Cerantola, V., Piltz, R.Crystallographic in corporation of hydrogen in ringwoodite.Goldschmidt Conference, 1p. AbstractMantlewater

Abstract: The transition zone (TZ) is believed to be the primary destination of subducted water [1], with the main TZ minerals (wadsleyite and ringwoodite) capable of holding up to ~ 3 wt.% H2O in their structures’. Observations of high attenuation and elevated conductivity suggest some areas of the transition zone are hydrated [2,3]. Combined with the observation of ~ 1.4 wt% H2O in a diamond-hosted ringwoodite inclusion [4], it is probable that the transition zone is at least regionally, if not globally, “wet”. The presence of water can induce partial melting, alter chemical partitioning and drastically change the strength of rocks. The detailed effect of water’s presence in the TZ will strongly depend on hydrogen’s incorporation mechanism, i.e. exchange with Si4+, Mg2+, Fe2+ cations or coupled substitution with Fe3+ in ringwoodite. Recent developments in neutron single-crystal Laue diffraction now allow measurements on crystals smaller than 0.1 mm3 [5]. Here we quantitatively study the incorporation of hydrogen in a synthetic iron-bearing ringwoodite. A multi-technique approach, with independent determination of chemistry, ferric iron content, water content and structure via x-ray and neutron diffraction allows a detailed study of the hydrous ringwoodite structure and the incorporation mechanism of water throughout Earth’s TZ.
DS1991-0701
1991
Brodholt, J.Hellfrich, G., Brodholt, J.Relationship of deep seismicity to the thermal structure of subductedlithosphere.Nature, Vol. 353, Sept. 19, pp. 252-5.MantleSubduction, mantle structure, Geophysics - seismics
DS200412-0215
2004
Brodholt, J.Brodholt, J.Constraining chemical heterogeneity in the Earth's lower mantle.Lithos, ABSTRACTS only, Vol. 73, p. S14. abstractMantleGeophysics - seismics, perovskites
DS200412-1435
2004
Brodholt, J.Nimmo, F., Price, G.D., Brodholt, J., Gubbins, D.The influence of potassium on core and geodynamo evolution.Geophysical Journal International, Vol. 156, 2, pp. 363-376.MantleMineralogy
DS200412-2075
2004
Brodholt, J.Walter, M.J., Kubo, A., Yoshino, T., Brodholt, J., Koga, K.T., Ohishi, Y.Phase relations and equation of state aluminous Mg silicate perovskite and implications for Earth's lower mantle.Earth and Planetary Science Letters, Vol. 222, 2, pp. 501-516.MantlePerovskite
DS200512-0849
2005
Brodholt, J.Petford, N., Yuen, D., Rushmer, T.,Brodholt, J., Stackhouse, S.Shear induced material transfer across the core mantle boundary aided by the post perovskite phase transition.Earth Planets and Space, Vol. 57, 5, pp. 459-464.MantleMineralogy
DS200612-0586
2006
Brodholt, J.Hirose, H., Karato, S., Comier, V., Brodholt, J., Yuen, D.Unsolved problems in the lowermost mantle.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 253. abstract only.MantleGeochemistry
DS200612-1543
2005
Brodholt, J.Wookey, J., Stackhouse, S., Kendall, J.M., Brodholt, J., Price, G.D.Efficacy of the post perovskite phase as an explanation for lowermost mantle seismic properties.Nature, No. 7070, Dec. 15, pp. 1004-1007.MantlePetrology
DS200812-0472
2007
Brodholt, J.Hirose, K., Brodholt, J., Lay, T., Yuen, D.A.An introduction to post-perovskite: the last mantle phase transition.AGU American Geophysical Union Monograph, No. 174, pp. 1-8.MantlePerovskite
DS200912-0076
2009
Brodholt, J.Brodholt, J., Amman, M., Hunt, S., Walker, S., Dobson, D.The rheological properties of post-perovskite and implications for D'.Goldschmidt Conference 2009, p. A162 Abstract.MantleBoundary
DS201112-1038
2011
Brodholt, J.Thomas, C., Wookey, J., Brodholt, J., Fieseler, T.Anisotropy as cause for polarity reversals of D' reflections.Earth and Planetary Science Letters, Vol. 307, 3-4, pp. 369-376.MantleGeophysics - seismics
DS201312-0380
2013
Brodholt, J.Hernandez, E.R., Alfe, D., Brodholt, J.The in corporation of water into lower mantle perovskites: a first principles study.Earth and Planetary Science Letters, Vol. 364, pp. 37-43.MantlePerovskite
DS201312-0580
2013
Brodholt, J.Martorell, B., Vocadlo, L., Brodholt, J., Wood, I.G.Strong premelting effect in the elastic properties of hcp-Fe under inner core conditions.Science, Vol. 342, 6157, pp. 466-468.MantleCore, melting
DS201312-1013
2013
Brodholt, J.Zhang, Z., Stixrude, L., Brodholt, J.Elastic properties of MgSiO3 perovskite under lower mantle conditions and the composition of the deep Earth.Earth and Planetary Science Letters, Vol. 379, pp. 1-12.MantlePerovskite
DS1991-0132
1991
Brodholt, J.P.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
DS1998-0167
1998
Brodholt, J.P.Brodholt, J.P., Dobson, D.Electrical conductivity of mantle minerals and the temperature of theEarth's lower mantle.Ima 17th. Abstract Vol., p. A 36, abstractMantleGeothermometry
DS2000-0239
2000
Brodholt, J.P.Dobson, D.P., Brodholt, J.P.The electrical conductivity and thermal profile of the Earth's Mid-MantleGeophysical Research Letters, Vol. 27, No. 15, Aug. 1, pp. 2325-28.MantleGeothermometry
DS2002-1171
2002
Brodholt, J.P.Oganov, A.R., Price, G.D., Brodholt, J.P.Theory of MgSiO3 perovskite: towards a thermal and mineralogical model of the Earth's mantle.18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.70.MantleUHP - mineralogy
DS2003-0169
2003
Brodholt, J.P.Brodholt, J.P., Oganov, A.R., Price, G.D.Computational mineral physics and the physical properties of perovskitePhilosophical Transactions of the Royal Society of London, Vol. 360, 1800, pp. 2507-20.GlobalMineralogy, mantle, perovskite
DS200412-0216
2003
Brodholt, J.P.Brodholt, J.P., Oganov, A.R., Price, G.D.Computational mineral physics and the physical properties of perovskite.Philosophical Transactions of the Royal Society of London Series A Mathematical Physical and Engineering Sciences, Vol. 360, 1800, pp. 2507-20.TechnologyMineralogy, mantle, perovskite
DS200712-0110
2007
Brodholt, J.P.Brodholt, J.P., Helffrich, G., Trampert, J.Chemical versus heterogeneity in the lower mantle: the most likely role of anelasticity.Earth and Planetary Science Letters, Vol. 262, 3-4, Oct. 30, pp. 429-437.MantleGeochemistry
DS201112-0215
2011
Brodholt, J.P.Cote, A.S., Brodholt, J.P., Badro, J.The composition of the Earth's outer core from first principles.Goldschmidt Conference 2011, abstract p.697.MantleLight elements, O-rich outer core
DS201909-2096
2019
Brodholt, J.P.Thomson, A.R., Crichton, W.A., Brodholt, J.P., Wood, I.G., Siersch, N.C., Muir, J.M.R., Dobson, D.P., Hunt, S.A..Seismic velocities of CaSiO3 perovskite can explain LLSVPs in Earth's lower mantle.Nature, Vol. 572, 7769, 18p. PdfMantleperovskite

Abstract: Seismology records the presence of various heterogeneities throughout the lower mantle1,2, but the origins of these signals—whether thermal or chemical—remain uncertain, and therefore much of the information that they hold about the nature of the deep Earth is obscured. Accurate interpretation of observed seismic velocities requires knowledge of the seismic properties of all of Earth’s possible mineral components. Calcium silicate (CaSiO3) perovskite is believed to be the third most abundant mineral throughout the lower mantle. Here we simultaneously measure the crystal structure and the shear-wave and compressional-wave velocities of samples of CaSiO3 perovskite, and provide direct constraints on the adiabatic bulk and shear moduli of this material. We observe that incorporation of titanium into CaSiO3 perovskite stabilizes the tetragonal structure at higher temperatures, and that the material’s shear modulus is substantially lower than is predicted by computations3,4,5 or thermodynamic datasets6. When combined with literature data and extrapolated, our results suggest that subducted oceanic crust will be visible as low-seismic-velocity anomalies throughout the lower mantle. In particular, we show that large low-shear-velocity provinces (LLSVPs) are consistent with moderate enrichment of recycled oceanic crust, and mid-mantle discontinuities can be explained by a tetragonal-cubic phase transition in Ti-bearing CaSiO3 perovskite.
DS202102-0230
2021
Brodholt, J.P.Wang, W., Zhang, H., Brodholt, J.P., Wu, Z.Elasticity of hydrous ringwoodite at mantle conditions: implications: implication for water distribution in the lower mantle transition zone.Earth and Planetary Science Letters, Vol. 554, doi:10.1016/ j.epsl.2020. 116626 12p. PdfMantlewater

Abstract: The mantle transition zone (MTZ) is potentially a geochemical water reservoir because of the high H2O solubility in its dominant minerals, wadsleyite and ringwoodite. Whether the MTZ is wet or dry fundamentally impacts our understanding of the deep-water distribution, geochemical recycling, and the pattern of mantle convection. However, the water content in the MTZ inferred from previous studies remains disputed. Seismic observations such as velocity anomalies were used to evaluate the water content in the MTZ, but the hydration effect on the velocities of MTZ minerals under appropriate pressure (P) and temperature (T) conditions is poorly constrained. Here we investigated the elastic properties and velocities of hydrous ringwoodite at high P-T conditions using first-principles calculations. Our results show that the hydration effects on elastic moduli and velocities of ringwoodite are significantly reduced by pressure but strongly enhanced by temperature. The incorporation of 1.0 wt% water into ringwoodite decreases the compressional and shear velocities of the pyrolitic mantle by ?1.0% and ?1.4% at the conditions of MTZ, respectively. Using results from seismic tomography and together with the topography of the 660-km discontinuity, we evaluate the global distribution of water in the lower MTZ. We find that about 80% of the MTZ can be explained by varying water content and temperature, however, the remaining 20% requires the presence of high-velocity heterogeneities such as harzburgite. Our models suggest an average water concentration of ?0.2 wt% in the lower MTZ, with an interregional variation from 0 to 0.9 wt%. Together with our previous work, we conclude that the water concentration in the MTZ likely decreases with depth globally and the whole MTZ contains the equivalent of about one ocean mass of water.
DS1996-0180
1996
Brodholt. J.Brodholt. J., Patel, A., Refson, K.An ab initio study of the compressional behavior of forsteriteAmerican Mineralogist, Vol. 81, pp. 257-60.MantleMineralogy
DS1986-0111
1986
Brodie, C.G.Brodie, C.G., Cooper, A.F.Nodule associations from ouachitite and camptonite lamprophyres Western Otago and South Westland, New ZealandProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 164-166GlobalCamptonite, Nodule
DS1989-0178
1989
Brodie, C.G.Brodie, C.G., Cooper, A.F.Nodule associations from ouachitite and camptonitelamprophyres, Western Otago and south Westland, NewZealandGeological Society of Australia Inc. Blackwell Scientific Publishing, Special, No. 14, Vol. 1, pp. 545-559GlobalMantle nodules, Ouachitite, Camptonite
DS1992-0168
1992
Brodie, M.J.Brodie, M.J., Banta, F.R., Skermer, N.A.RCRA regulation on Alaska mineral development waste rock managementUnited States Bureau of Mines Open File Report, No. OFR 95-92, 99pAlaskaLegal, legislation, lead, zinc, Waste rock
DS1995-0214
1995
Brodie, M.J.Brodie, M.J.Corporate considerations in mine decommissioningThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin), Vol. 88, No. 989, April pp. 50-54CanadaLegal, Environment
DS1997-0796
1997
Brodie, R.C.Minty, B.R.S., Luyendyk, A.P.J., Brodie, R.C.Calibration and dat a processing for airborne gamma ray spectrometryAgso Journal, Australian Geology And Geophysics, Vol. 17, No. 2, pp. 51-62AustraliaGeophysics - airborne, Data management
DS1990-0241
1990
Brodin, B.V.Brodin, B.V., Shulgin, A.S., Dubinchuk, V.T., Sidorenko, G.A.The mineralogy of low temperature hydrothermal molybdenum depositsInternational Geology Review, Vol. 32, No. 11, November pp. 1156-1165RussiaMolybdenuM., Mineralogy
DS202104-0586
2021
Brodnikova, E.A.Letnikova, E.F., Izokh, A.E., Kosticin, Y.A., Letnikov, F.A., Ershova, V.B., Federyagina, E.N., Ivanov, A.V., Nojkin, A.D., Shkolnik, S.I., Brodnikova, E.A.High-potassium volcanism approximately 640 Ma in the southwestern Siberian platform ( Biryusa uplift Sayan region).Doklady Earth Sciences, Vol. 496, 1, pp. 53-59.Russia, Siberiaalkaline rocks

Abstract: On the basis of petrographic and mineralogical studies, we have established the presence of clastic rocks with a strong predominance of K-feldspar among the rock-forming fragments within the Late Precambrian sedimentary sequence in the southwestern part of the Siberian Platform. Two types of mineralogical occurrence of K-feldspars are determined: (1) huge zonal crystal clasts with increased Ba concentrations in the central parts of the grains and (2) the main mineral phase in the form of a decrystallized glassy mass. In both cases, low concentrations of Na (lower than 0.1 wt %) are detected. K-feldspars of the second type contain intergrowths of idiomorphic rhombic dolomite with a high ankerite component. Dolomite grains contain inclusions of K-feldspar. The prevailing accessory minerals are F-apatite (with high concentrations of REEs), zircon (with high concentrations of Th), magnetite, rutile, monacite, and sinchizite. Encasement minerals with an idiomorphic shape are identified, with K-feldspar being located in the center, while the middle shell is formed by apatite with a high REE content, and the outer shell is formed by apatite without rare earth elements. These rocks are products of high-potassium volcanic activity. The age of this event has been established on the basis of U-Pb zircon dating to about 640 Ma. The Lu-Hf zircon systematics for these rocks indicates the connection of volcanism with igneous events of mantle genesis within its range. The products of explosive eruption, which are widespread within the Biryusa uplift of the Siberian Platform, were erroneously considered earlier as Riphean sedimentary rocks of the Karagas Series.
DS1970-0077
1970
Brodovoi, V.V.Fedynsky, V.V., Brodovoi, V.V., Gelamkov, V.A.Geophysics in Prospecting for Mineral Deposits in the UssrGeological Survey of Canada (GSC) Economic Geology Report, No. 26, PP. 667-687.Russia, YakutiaKimberlite, Geophysics
DS1990-0242
1990
Brodskaya, S.Y.Brodskaya, S.Y., Sharanova, Z.V., Genshaft, Y.S., Ilupin, I.P.Temperatures of secondary geologic processes in the Yakutia kimberlites evaluated from magneticdata.(Russian)Izvest. Akad. Nauk, SSSR, (Russian), No. 1, January pp. 62-70. ISI# CR 707RussiaGeophysics -magnetics, Alteration
DS1975-0962
1979
Brodskaya, S.YU.Brodskaya, S.YU., et al.Magnetism of Yakutian and Azov Sea Area KimberlitesFizika Zemli., Vol. 11, PP. 82-88.Russia, Yakutia, UkraineKimberlite, Geophysics
DS1983-0153
1983
Brodskaya, S.YU.Brodskaya, S.YU., Valeyev, K.A.The Origin of Carbonatites of the Gulinskaya Alkaline Ultrabasic Intrusion.Physics Solid Earth, Vol. 19, No. 5, PP. 421-424.RussiaBlank
DS1987-0079
1987
Brodskaya, S.Yu.Brodskaya, S.Yu., Pecherskii, D.M., Epshtein, E.M.Temperature related evolution of ferrospinels of ultramafic rocks and carbonatites based on petromagnetic and mineralogical studies.(Russian)Izv. Akad. Nauk SSSR Fiz. Zemli, (Russian), No. 10, pp. 66-78RussiaCarbonatite
DS1989-0179
1989
Brodskaya, S.Yu.Brodskaya, S.Yu., Milyutin, S.A., Sharonova, Z.V.Mineralogy of the binder mass of Yakutia kimberlites according to datafrom thermoweight and thermomagnetic investigations.(Russian)Akad. Nauk SSSR Institute Fiz., (Russian), Vol. 11, No. 4, pp. 58-68RussiaPetrology, Mineralogy
DS1988-0087
1988
Brodtkorb, M.K. de.Brodtkorb, M.K. de.Nonmetalliferous stratabound ore fields. Barite deposits of ArkansawVan Nostrand Reinhold, pp. 119-148ArkansasBarite
DS1992-0169
1992
Brody, J.Brody, J.Energy, economics and environment... overview of conferenceAustralian Institute of Mining and Metallurgy (AusIMM) Bulletin, No. 5, August p. 26-29AustraliaConference overview, Energy, environment
DS201812-2783
2018
Broecker, W.Broecker, W.CO2: Earth's climate driver.Geochemical Perspectives, Vol. 7, no. 2, pp. 117-196. doi: 10.7185/geochempersp.7.2Mantlecarbon

Abstract: As we struggle to cope with the ongoing buildup of CO2 produced by burning fossil fuels, can we acquire guidance from the geologic record? Although our ability to reconstruct past atmospheric CO2 content reliably is currently confined to the last 800 thousand years, we do have compelling evidence that this greenhouse gas played a key role throughout the Earth’s history. It certainly compensated for the young Sun’s lower luminosity. There is no question that it bailed us out of two snowball episodes or that it led to a brief 5 °C warming at the onset of the Eocene. Less certain is that diminishing atmospheric CO2 content was responsible for the global cooling that began 50 million years ago when the Indian subcontinent collided with Asia. Finally, it colluded with changing seasonality, ocean circulation re-organisation and iron fertilisation to generate the 100 thousand year glacial cycles that dominated the last half-million years.
DS1990-0243
1990
Broecker, W.S.Broecker, W.S., Denton, G.H.What drive's glacial cycles?Scientific American, Vol. 262, No. 1, January pp. 48-107GlobalAstronomy, General overview of Global climates
DS1992-0083
1992
Broecker, W.S.Bard, E., Broecker, W.S.The last deglaciation: absolute and radiocarbon chronologiesSpringer-Verlag, 352p. approx. $ 160.00 United StatesGlobalGeomorphology, Deglaciation
DS1992-0170
1992
Broecker, W.S.Broecker, W.S.Discovery of a large offset in the radiocarbon time scaleEos Transactions, Vol. 73, No. 3, Jan. 21, p. 32GlobalGeochronology, Radiocarbon
DS1995-0215
1995
Broecker, W.S.Broecker, W.S.Chaotic climate...global temperatures changing.Scientific American, Nov. pp. 62-68GlobalClimate, Global temperature
DS1920-0059
1921
Broegger, W.C.Broegger, W.C.Die Eruptive gesteine des Kristianiagabietes. Iv. das Fengebiet in Telemark, Norwegen.Kong. Norske Vidensk. Selsk. Skr., No. 9, PP. 1-408.Norway, ScandinaviaUltramafic And Related Rocks, Carbonatite
DS1992-0171
1992
Broen, G.E. Jr.Broen, G.E. Jr.Global change and the new definition of progressGeotimes, Vol. 37, No. 6, June pp. 19-21GlobalGlobal change, Climate
DS1990-0888
1990
Broks, T.M.Krogh, E.T., Andresen, A., Bryhni, I., Broks, T.M., KristenesenEclogites and polyphase P-T cycling in the Caledonian uppermost allochthonin Troms, northern NorwayJournal of Metamorphic Geology, Vol. 8, No. 3, May pp. 289-310NorwayEclogites
DS202108-1303
2021
Brolly, C.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.
DS201312-0087
2013
Broman, C.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
DS2002-0207
2002
Bromann Klausen, M.Bromann Klausen, M., Larsen, H.C.East Greenland coast parallel dike swarm and its role in continental breakupGeological Society of America Special Paper, No. 192, pp. 133-158.GreenlandDike swarms, Tectonics
DS200412-0217
2002
Bromann Klausen, M.Bromann Klausen, M., Larsen, H.C.East Greenland coast parallel dike swarm and its role in continental breakup.Geological Society of America Special Paper, No. 192, pp. 133-158.Europe, GreenlandDike swarms Tectonics
DS200412-0219
2004
Bromiley, F.A.Bromiley, G.D., Keppler, H., McCammon, C., Bromiley, F.A., Jacobsen, S.D.Hydrogen solubility and speciation in natural gem quality chromian diopside.American Mineralogist, Vol. 89, 6, pp. 941-949.TechnologyPetrology, experimental ( not specific to diamonds)
DS200412-0218
2004
Bromiley, G.Bromiley, G., Hilaret, N., McCammon, C.Solubility of hydrogen and ferris iron in rutile and TiO1(II): implications for phase assemblages during ultrahigh pressure metaGeophysical Research Letters, Vol. 31, 4, Feb. 28, DOI 1029/2004 GLO19430MantleSilica polymorphs in the lower mantle
DS200612-1325
2006
Bromiley, G.Smyth, J.R., Frost, D.J., Nestola, F., Holl, C.M., Bromiley, G.Olivine hydration in the deep upper mantle: effects of temperature and silica activity.Geophysical Research Letters, Vol. 33, 15, August 16, L15301MantleMineral chemistry
DS200412-0219
2004
Bromiley, G.D.Bromiley, G.D., Keppler, H., McCammon, C., Bromiley, F.A., Jacobsen, S.D.Hydrogen solubility and speciation in natural gem quality chromian diopside.American Mineralogist, Vol. 89, 6, pp. 941-949.TechnologyPetrology, experimental ( not specific to diamonds)
DS200412-1269
2004
Bromiley, G.D.McEnroe, S.A., Langenhorst, F., Robinson, P., Bromiley, G.D., Shaw, C.S.J.What is magnetic in the lower crust?Earth and Planetary Science Letters, Vol. 226, 1-2, Sept. 30, pp.175-192.MantleMagnetic anomalies, hematite-ilmenite, Curie isotherm
DS200712-0111
2007
Bromiley, G.D.Bromiley, G.D., Redfern, S.A.T.The role of rutile/TiO2(II) during melting of ancient, subducted oceanic crust: implications for oceanic island magmatism.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p. 93-94.MantleMagmatism
DS200712-0112
2007
Bromiley, G.D.Bromiley, G.D., Redfern, S.A.T.The role of rutile/TiO2(II) during melting of ancient, subducted oceanic crust: implications for oceanic island magmatism.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p. 93-94.MantleMagmatism
DS200812-0143
2008
Bromiley, G.D.Bromiley, G.D., Redfern, S.A.T.The role of TiO2 phases during melting of subduction modified crust: implications for deep mantle melting.Earth and Planetary Science Letters, Vol. 267, 1-2, pp.301-308.MantleMelting
DS201610-1869
2016
Bromiley, G.D.Hastie, A.R., Fitton, J.G., Bromiley, G.D., Butler, I.B., Oding, W.A.The origin of Earth's first continents and the onset of plate tectonics.Geology, Vol. 44, 10, pp. 855-858.MantleSubduction

Abstract: The growth and recycling of continental crust has resulted in the chemical and thermal modification of Earth's mantle, hydrosphere, atmosphere, and biosphere for ?4.0 b.y. However, knowledge of the protolith that gave rise to the first continents and whether the environment of formation was a subduction zone still remains unknown. Here, tonalite melts are formed in high P-T experiments in which primitive oceanic plateau starting material is used as an analogue for Eoarchean (3.6-4.0 Ga) oceanic crust generated at early spreading centers. The tonalites are produced at 1.6-2.2 GPa and 900-950 °C and are mixed with slab-derived aqueous fluids to generate melts that have compositions identical to that of Eoarchean continental crust. Our data support the idea that the first continents formed at ca. 4 Ga and subsequently, through the subduction and partial melting of ?30-45-km-thick Eoarchean oceanic crust, modified Earth's mantle and Eoarchean environments and ecosystems.
DS2002-0208
2002
Bromily, G.D.Bromily, G.D., Pawley, A.R.The high pressure stability of Mg sursassite in a model hydrous peridotite: a possible mechanism for subductionContribution to Mineralogy and Petrology, Vol.142, 6, Jan.pp.714-23.MantleSubduction - deep, significant volumes of H2O, water, magnesium sursassite
DS201112-0113
2011
Bromley, D.Bromley, D., Foltz, J.Sustainability under siege: transport costs and corruption on West Africa's trade corridors.Natural Resources Forum, Vol. 35, 1, Feb. pp. 32-48.Africa, West AfricaCSR
DS1991-0981
1991
Bronner, G.Lesquer, A., Villeneuve, J.C., Bronner, G.Heat flow dat a from the western margin of the West African craton(Mauritania)Physics of the Earth and Planetary Interiors, Vol. 66, pp. 320-329GlobalHeat flow, Craton
DS1995-0536
1995
Bronner, G.Feybesse, J.L., Bronner, G.The Monts Nimba and Simandou Ranges: allochthonous terranes resting upon the Archean basement?Geological Society Africa 10th. Conference Oct. Nairobi, p. 21. AbstractWest AfricaCraton, Tectonics not specific to diamonds
DS1989-0180
1989
Bronw, T.H.Bronw, T.H., Berman, R.G., Perkins, E.H.PTA-SYSTEM:a Geo-calc software package for the calculation and display of activity temperature pressure phase diagramsAmerican Mineralogist, Vol. 74, No. 3-4, March-April pp. 485-487GlobalComputer, Program -PTA -system
DS201412-0074
2013
Brook, M.Brook, M.Botswana Diamonds. Prospecting to Jewellery. Beautiful coloured photographs, history to current.Available signed by author or from Amazon.com 286p., Priced incl. postage SADC Countries $ US 50. Rest of Africa, Europe $ US 75. USA,Canada and rest of world $ US80.News item - Book
DS202008-1371
2018
Brook, M.C.Brook, M.C.The Botswana pipeline - "prospecting to jewellery"Botswana Journal of Earth Sciences, Vol. 7, pp. 43-57. pdfAfrica, Botswanaprospecting, markets

Abstract: In this paper I describe the different components that make up the Botswana Diamond Pipeline today, which means the supply chain of diamonds, that ranges from diamond prospecting to mining, to diamond processing and recovery, to rough diamond sorting, valuation, sales and marketing, to diamond polishing and cutting, and finally to diamond jewellery manufacturing and retail. In Botswana, we can now truly witness the journey of the diamond from “Rough to Finger” or from “Mine to Store” (Fig. 1). Today, Botswana is the world’s second largest producer of diamonds by value and volume after Russia, and there are currently twelve known kimberlite fields (Fig. 2) and eight operating diamond mines. Botswana’s diamonds are cut and polished into beautiful diamond jewellery locally and across the globe.
DS202205-0675
2022
Brooke, K.Brooke, K.Melilites ( minerals explained)Geology Today, Vol. 38, 1, 5p.Globalmelilites

Abstract: The melilites are a group of little-known silicate minerals. In nature, the commonest are rock-forming minerals found in the igneous rocks characterized by a low silica content (undersaturated rocks), in contact metamorphic rocks formed where igneous rocks invade impure limestones. They are also found in artificial slags and primitive meteorites, where they are an important component of the oldest material in the Solar System.
DS200612-1342
2006
BrookerSparks, R.S.J., Baker, Brooker, Brown, Field, Fontana, Gernon, Kavanagh, Shumacher, Stripp, Walter, Walters, White, WindsorDynamical constraints on kimberlite volcanism,Emplacement Workshop held September, 5p. abstractGlobalMagmatism, water, stages
DS1991-0179
1991
Brooker, P.I.Brooker, P.I.A geostatistical primerWorld Scientific Publishing, $ 32.00 approxGlobalBook review, Geostatistics
DS1997-0131
1997
Brooker, R.Brooker, R., Holloway, J.R.The role of CO2 saturation in silicate carbonatite magmatic systemsGeological Association of Canada (GAC) Abstracts, GlobalCarbonatite
DS200412-0168
2004
Brooker, R.Blundy, J., Brooker, R.Chemical discrimination between melts from the lower crust and slab.Lithos, ABSTRACTS only, Vol. 73, p. S10. abstractMantleSubduction
DS200512-0696
2005
Brooker, R.Matveev, S., Portnyagin, M., Ballhaus, C., Brooker, R., Geiger, C.A.Spectrum of phenocryst olivine as an indicator of silica saturation in magmas.Journal of Petrology, Vol. 46, 3, pp. 603-614.MantleMagmatism
DS200612-0175
2006
Brooker, R.Brooker, R.The role of experiments and theory in understanding volatile control on the kimberlite eruption mechanism.Emplacement Workshop held September, 5p. extended abstractTechnologyModels, melt structure
DS201212-0694
2012
Brooker, R.Sparks, R.S.J., Buisman, I., Brooker, R., Brown, R.J., Field, M., Gernon, T., Kavanagh,J., Ogilvie-Harris, R., Schumacher, J.C.Dynamics of kimberlite magam ascent, intrusion and eruption.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractGlobalDiamond genesis
DS201312-0101
2013
Brooker, R.Brooker, R.Evolution of chemical and physical properties of mixed arc magmas.Goldschmidt 2013, AbstractTechnologyMagmatism
DS201312-0102
2013
Brooker, R.Brooker, R.Trace element partitioning between carbonate globules and silicate glass in volcanic carbonatites.Goldschmidt 2013, AbstractTechnologyCarbonatite
DS1990-0244
1990
Brooker, R.A.Brooker, R.A., Hamilton, D.L.Three liquid immisicibility and the origin of carbonatitesNature, Vol. 346, No. 6283, ugust 2, pp. 459-461GlobalCarbonatite, Chemistry
DS1990-0245
1990
Brooker, R.A.Brooker, R.A., Hamilton, D.L.Three liquid immiscibility and the origin of carbonatitesTerra, Abstracts of Experimental mineralogy, petrology and, Vol. 2, December abstracts p. 67GlobalOrigin, Carbonatite
DS1998-0168
1998
Brooker, R.A.Brooker, R.A.The effect of CO2 saturation on immiscibility between silicate and carbonate liquids: an experimental study.Journal of Petrology, Vol. 39, No. 11-12, Nov-Dec. pp. 1905-15.GlobalCarbonatite, Petrology - experimental
DS2003-0170
2003
Brooker, R.A.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
DS200412-0220
2003
Brooker, R.A.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
DS200412-0221
2004
Brooker, R.A.Brooker, R.A., Heber, V.S., Kelly, S.P., Wood, B.J.Noble gas partitioning during mantle melting: possible retention of He & Ar relative to U, Th & K.Lithos, ABSTRACTS only, Vol. 73, p. S15. abstractMantleMelting
DS200512-0115
2004
Brooker, R.A.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
DS200612-0491
2006
Brooker, R.A.Grant, K.J., Kohn, S.C., Brooker, R.A.Solubility and partitioning of water in synthetic forsterite and enstatite in the system MgO SiO2 and H2Al2O3.Contributions to Mineralogy and Petrology, Vol. 151, 6, pp. 651-664.TechnologyPetrology
DS200712-0380
2007
Brooker, R.A.Grant, K.J., Brooker, R.A., Kohn, S.C., Wood, B.J.The effect of oxygen fugacity on hydroxyl concentrations and speciation in olivine: implications for water solubility in the upper mantle.Earth and Planetary Science Letters, Vol. 261, 1-2, pp. 217-229.MantleWater
DS200912-0719
2009
Brooker, R.A.Sparks, R.S.J., Brooker, R.A., Field, M., Kavanagh, J., Schumacher, J.C., Walter, M.J., White, J.The nature of erupting kimberlite melts.Lithos, In press available, 30p.MantleMelting
DS201112-0114
2011
Brooker, R.A.Brooker, R.A., Kjarsgaard, B.A.Silicate carbonate liquid immiscibility and phase relations in the system SiO2-Na2O-Al2O3-CaO-CO2 at 0.1-2.5 GPa with application to carbonatite genesis.Journal of Petrology, Vol. 52, 7-8, pp. 1281-1305.TechnologyCarbonatite
DS201112-0115
2011
Brooker, R.A.Brooker, R.A., Sparks, R.S.J., Kavanagh, J.L., Field, M.The volatile content of hypabyssal kimberlite magmas: some constraints from experiments on natural rock compositions.Bulletin Volcanology, in press available 23p.Canada, Nunavut, Northwest Territories, Africa, South AfricaDeposit - Jericho, Lac de Gras
DS201212-0529
2012
Brooker, R.A.Ogilvie-Harris, R.C., Field, M., Brooker, R.A., Walter, M.J., Sparks, R.S.J.The petrology of AK6, Botswana: implications of volcanic and igneous processes.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractAfrica, BotswanaDeposit - AK6
DS201212-0530
2012
Brooker, R.A.Ogily-Harris, R.C., Brooker, R.A., Sparks, R.S.J., Walter, M.J.An experimental investigation of the carbonatite-kimberlite melt.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractAfrica, South AfricaDeposit - Dutoitspan
DS201602-0247
2016
Brooker, R.A.Thomson, A.R., Walter, M.J., Kohn, S.C., Brooker, R.A.Slab melting as a barrier to deep carbon subduction. ( super deep diamonds)Nature, Vol. 529, Jan. 7, pp. 76-94.MantleSubduction

Abstract: Interactions between crustal and mantle reservoirs dominate the surface inventory of volatile elements over geological time, moderating atmospheric composition and maintaining a life-supporting planet. While volcanoes expel volatile components into surface reservoirs, subduction of oceanic crust is responsible for replenishment of mantle reservoirs. Many natural, 'superdeep' diamonds originating in the deep upper mantle and transition zone host mineral inclusions, indicating an affinity to subducted oceanic crust. Here we show that the majority of slab geotherms will intersect a deep depression along the melting curve of carbonated oceanic crust at depths of approximately 300 to 700 kilometres, creating a barrier to direct carbonate recycling into the deep mantle. Low-degree partial melts are alkaline carbonatites that are highly reactive with reduced ambient mantle, producing diamond. Many inclusions in superdeep diamonds are best explained by carbonate melt-peridotite reaction. A deep carbon barrier may dominate the recycling of carbon in the mantle and contribute to chemical and isotopic heterogeneity of the mantle reservoir.
DS202106-0925
2021
Brooker, R.A.Broom-Findley, S., Siegfried, P.R., Wall, F., O'Neill, M., Brooker, R.A., Fallon, E.K., Pickles, J.R., Banks, D.A.The origin and composition of carbonatite-derived carbonate bearing fluorapatite deposits.Mineralium Deposita, Vol. 56, pp. 863-884.Globaldeposit - Kovdor, Sokli, Bukusu, Catalao 1, Glenover

Abstract: Carbonate-bearing fluorapatite rocks occur at over 30 globally distributed carbonatite complexes and represent a substantial potential supply of phosphorus for the fertiliser industry. However, the process(es) involved in forming carbonate-bearing fluorapatite at some carbonatites remain equivocal, with both hydrothermal and weathering mechanisms inferred. In this contribution, we compare the paragenesis and trace element contents of carbonate-bearing fluorapatite rocks from the Kovdor, Sokli, Bukusu, Catalão I and Glenover carbonatites in order to further understand their origin, as well as to comment upon the concentration of elements that may be deleterious to fertiliser production. The paragenesis of apatite from each deposit is broadly equivalent, comprising residual magmatic grains overgrown by several different stages of carbonate-bearing fluorapatite. The first forms epitactic overgrowths on residual magmatic grains, followed by the formation of massive apatite which, in turn, is cross-cut by late euhedral and colloform apatite generations. Compositionally, the paragenetic sequence corresponds to a substantial decrease in the concentration of rare earth elements (REE), Sr, Na and Th, with an increase in U and Cd. The carbonate-bearing fluorapatite exhibits a negative Ce anomaly, attributed to oxic conditions in a surficial environment and, in combination with the textural and compositional commonality, supports a weathering origin for these rocks. Carbonate-bearing fluorapatite has Th contents which are several orders of magnitude lower than magmatic apatite grains, potentially making such apatite a more environmentally attractive feedstock for the fertiliser industry. Uranium and cadmium contents are higher in carbonate-bearing fluorapatite than magmatic carbonatite apatite, but are much lower than most marine phosphorites.
DS2002-0209
2002
Brookes, I.A.Brookes, I.A.G.M. Dawson and the glaciation of Western CanadaGeoscience Canada, Vol. 29, 7, Sept. pp. 169-178.British Columbia, Western Canada plainsGeomorphology - glaciation, history, biography
DS1992-0587
1992
Brookfield, M.E.Goodings, C.R., Brookfield, M.E.Proterozoic transcurrent movements along the Kapuskasing lineament(Superior Province, Canada) and their relationship to surrounding structuresEarth Science Reviews, Vol. 32, pp. 147-185OntarioTectonics, Structure, Kapuskasing Rift - lineament
DS1993-0165
1993
Brookfield, M.E.Brookfield, M.E.Neoproterozoic Laurentia-Australia fitGeology, Vol. 21, No. 8, August pp. 683-686Australia, Utah, IdahoTectonics, Western North American margin
DS2000-0111
2000
Brookfield, M.E.Brookfield, M.E.Geological development and Phanerozoic crustal accretion in the western segment southern Tien Shan.Tectonophysics, Vol. 328, no, 1-2 Dec.20, pp.1-14.GlobalTectonics
DS1960-0640
1966
Brookins, D.G.Brookins, D.G., Eastwood, R.L.A Spectrochemical Investigation of the Bala and Stockdale Intrusion, Riley County, Kansas.Kansas Academy of Science Transactions, Vol. 68, PP. 72-87.KansasKimberlite, Central States, Geochemistry
DS1960-0797
1967
Brookins, D.G.Brookins, D.G.The Strontium Geochemistry of Carbonates in Kimberlites And limestones from Riley County, Kansas.Earth Planet. Sci. Lett., Vol. 2, PP. 235-240.KansasKimberlite, Central States
DS1960-0798
1967
Brookins, D.G.Brookins, D.G.Re-examination of Pyrope from the Stockdale Kimberlite, Riley County, Kansas.Mineralogical Magazine., Vol. 36, PP. 450-452.KansasKimberlite, Central States
DS1960-0799
1967
Brookins, D.G.Brookins, D.G.Kansas KimberliteEarth Science., MAY-JUNE, PP. 109-114.KansasKimberlite, Central States, Riley
DS1960-0800
1967
Brookins, D.G.Brookins, D.G., Mcdermott, V.J.Age and Temperature of Intrusions of Kimberlite, Riley County, Kansas.Geological Society of America (GSA) SPECIAL PAPER., No. 115, P. 336, (abstract.).KansasKimberlite, Central States
DS1960-0874
1967
Brookins, D.G.Rosa, F., Brookins, D.G.The Mineralogy of the Stockdale Kimberlite Pipe, Riley County, Kansas.Kansas Academy of Science Transactions, Vol. 69, No. 3-4, PP. 335-344.KansasKimberlite, Central States
DS1960-0927
1968
Brookins, D.G.Brookins, D.G.Kimberlites from Riley County, KansasGeological Society of America (GSA) SPECIAL PAPER., No. 101, PP. 26-27.KansasKimberlite, Central States
DS1960-0928
1968
Brookins, D.G.Brookins, D.G.Strontium Geochemistry of Carbonates Associated with Kimberlites, from Riley County, Kansas.Geological Society of America (GSA) SPECIAL PAPER., No. 101, P. 27, (abstract.).KansasBlank
DS1960-1076
1969
Brookins, D.G.Brookins, D.G.Riley County, Kansas, Kimberlites and their InclusionsGeological Society of America (GSA), Vol. 2, No. 1, P. 271, (abstract.).KansasKimberlite, Central States
DS1960-1077
1969
Brookins, D.G.Brookins, D.G.Spinel from the Stockdale Kimberlite, Riley County, KansasKansas Academy of Science Transactions, Vol. 72, PP. 262-263.KansasKimberlite, Central States
DS1960-1078
1969
Brookins, D.G.Brookins, D.G.A List of Minerals Found in Riley County KimberlitesKansas Academy of Science Transactions, Vol. 72, PP. 365-373.KansasKimberlite, Central States
DS1960-1079
1969
Brookins, D.G.Brookins, D.G.Possible Age of Crystallization of Pyrope from the Stockdale Kimberlite, Kansas.Geochemical Journal (JAPAN), Vol. 3, No. 2-3, PP. 135-140.KansasKimberlite, Central States, Geochronology
DS1960-1080
1969
Brookins, D.G.Brookins, D.G.The Significance of Potassium-argon Dates on Altered Kimberlite Phlogopite from Riley County, Kansas.Journal of Geology, Vol. 77, No. 1, PP. 102-107.KansasKimberlite, Central States, Geochronology
DS1960-1081
1969
Brookins, D.G.Brookins, D.G.Investigation of Winkler Crater (kansas)Meteorites, Vol. 4, No. 4, PP. 263-264.KansasKimberlite, Central States, Riley
DS1960-1082
1969
Brookins, D.G.Brookins, D.G., Watson, K.D.The Strontium Geochemistry of Calcite Associated with Kimberlite at Bachelor Lake, Quebec.Journal of GEOLOGY, Vol. 77, No. 3, PP. 367-371.Canada, QuebecBlank
DS1960-1096
1969
Brookins, D.G.Dyer, R.G., Brookins, D.G.Mineralogy and Petrography of the Leonardville Kimberlite, Riley County, Kansas.Geological Society of America (GSA), PT. 2, P. 10, (abstract.).United States, Kansas, Central StatesBlank
DS1970-0033
1970
Brookins, D.G.Brookins, D.G.Factors Governing Emplacement of Riley County KimberlitesKansas Geological Survey Bulletin, No. 199, PT. 4, PP. 1-17.KansasKimberlite, Central States
DS1970-0034
1970
Brookins, D.G.Brookins, D.G.The Kimberlites of Riley County, KansasKansas Geological Survey Bulletin, No. 200, 32P.KansasKimberlite, Central States
DS1970-0035
1970
Brookins, D.G.Brookins, D.G.Mechanism(s) of Emplacement of Riley County, Kansas, Kimberlites.Geological Society of America (GSA), Vol. 3, No. 4, P. 271, (abstract.).KansasKimberlite, Central States
DS1970-0036
1970
Brookins, D.G.Brookins, D.G.Kimberlite at Winkler CraterGeological Society of America (GSA) Bulletin., Vol. 81, No. 2, PP. 541-545.KansasKimberlite, Central States, Riley
DS1970-0037
1970
Brookins, D.G.Brookins, D.G., Mcdermott, V.J.The Mineralogy of the Randolph Kimberlite, Riley County, Kansas.Kansas Academy of Science Transactions, Vol. 73, No. 1, PP. 31-39.KansasKimberlite, Central States
DS1970-0038
1970
Brookins, D.G.Brookins, D.G., Woods, M.J.Rubidium-strontium Geochronologic Investigation of Basic and Ultrabasic xenoliths from the Stockdale Kimberlite, Riley County, Kansas.Kansas Geological Survey Bulletin, No. 199, PT. 2, PP. 1-12. ALSO: Geological Society ofKansasKimberlite, Central States
DS1970-0039
1970
Brookins, D.G.Brookins, D.G., Woods, M.J.high pressure MINERAL REACTIONS in a PYROXENITE GRANULITE from the STOCKDALE KIMBERLITE.Kansas Geological Survey Bulletin, No. 199, PT. 3, PP. 1-6.KansasKimberlite, Central States, Crustal Xenoliths
DS1970-0071
1970
Brookins, D.G.Dyer, R.G., Brookins, D.G.Petrography and Geochemistry of the Leonardville Kimberlite, Riley County, Kansas.Kansas Academy of Science Transactions, Vol. 73, PP. 460-480.United States, Kansas, Central StatesBlank
DS1970-0253
1971
Brookins, D.G.Brookins, D.G.Ilmenite-(serpentinized) Pyroxene Nodules from the Stockdale Kimberlite Pipe, Riley County, Kansas.Geological Society of America (GSA), Vol. 3, No. 3, P. 233, (abstract.).KansasKimberlite, Central States, Oxide-silicate Intergrowths
DS1970-0254
1971
Brookins, D.G.Brookins, D.G., Naeser, C.S.Age of Emplacement of Riley County, Kansas Kimberlites and A Possible Minimum Age for the Dakota Sandstone.Geological Society of America (GSA) Bulletin., Vol. 82, No. 6, PP. 1723-1726.KansasKimberlite, Central States, Geochronology
DS1970-0355
1971
Brookins, D.G.Meyer, H.O.A., Brookins, D.G.Sapphirine-bearing Xenoliths from Stockdale Kimberlite Pipe, Kansas.Geological Society of America (GSA), Vol. 3, P. 646, (abstract.).KansasKimberlite, Central States
DS1970-0356
1971
Brookins, D.G.Meyer, H.O.A., Brookins, D.G.Eclogite Xenoliths from Stockdale Kimberlite, KansasContributions to Mineralogy and Petrology, Vol. 34, PP. 60-72.KansasKimberlite, Central States
DS1970-0760
1973
Brookins, D.G.Mccallister, R.H., Meyer, H.O.A., Brookins, D.G.Pyroxene - Ilmenite Xenoliths from the Stockdale Pipe; KanProceedings of First International Kimberlite Conference, PP. 213-215, (abstract.).KansasKimberlite, Central States, Oxide-silicate Intergrowths
DS1970-0886
1974
Brookins, D.G.Brookins, D.G., Meyer, H.O.A.Crustal and Upper Mantle Stratigraphy Beneath Eastern KansasGeophysical Research Letters, Vol. 1, No. 6, OCTOBER, PP. 269-272.United States, Kansas, Central StatesKimberlite, Genesis
DS1975-0042
1975
Brookins, D.G.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
Brookins, D.G.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
DS1975-0130
1975
Brookins, D.G.Mccallister, R.H., Meyer, H.O.A., Brookins, D.G.Pyroxene - Ilmenite Xenoliths from the Stockdale Pipe; KanPhysics And Chemistry of Earth, Vol. 9, PP. 287-294.KansasKimberlite, Central States, Oxide-pyroxene Intergrowths
DS1975-0245
1976
Brookins, D.G.Bolivar, S., Brookins, D.G.Geochemistry of the Elliott County, Kentucky, KimberlitesEos, Vol. 57, No. 10, P. 761. (abstract.).Appalachia, KentuckyGeochemistry
DS1975-0246
1976
Brookins, D.G.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
Brookins, D.G.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
Brookins, D.G.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
Brookins, D.G.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
DS1975-0331
1976
Brookins, D.G.Mansker, W.L., Brookins, D.G., Landis, G.P., et al.Post Devonian Distremes in Southeast Missouri, Investigation of the Avon Kimberlite and Some Emplacement Parameters.Eos, Vol. 57, No. 10, P. 761, (abstract.).GlobalKimberlite, Central States, Alnoite
DS1975-0347
1976
Brookins, D.G.Meyer, H.O.A., Brookins, D.G.Sapphirine, Sillimanite and Granulite Xenoliths from Stockdale Kimberlite Kansas.American MINERALOGIST., Vol. 61, No. 11-12, PP. 1194-1202.KansasKimberlite, Central States, Riley County, Crustal Xenoliths
DS1975-0348
1976
Brookins, D.G.Meyer, H.O.A., Brookins, D.G.Occurrence of Kimberlites in the United StatesEos, Vol. 57, No. 10, P. 761. (abstract.).United States, Appalachia, Central States, Gulf Coast, Rocky MountainsBlank
DS1975-0572
1977
Brookins, D.G.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
Brookins, D.G.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
Brookins, D.G.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
DS1985-0089
1985
Brookins, D.G.Brookins, D.G., Mansker, W.L.Upper Mantle and Crustal Rocks in North Central Kansas: Evidence from Kimberlites.6th. International Conference Basement Tectonics, Held Sant Fe, Septemb, P. 13. (abstract.).United States, Central States, KansasPetrography, Geochemistry, Geophysics
DS1986-0112
1986
Brookins, D.G.Brookins, D.G., Mansker, W.L.Upper mantle and crustal rocks in North Central Kansas: evidence fromkimberlitesInternational Basement Tectonics Sixth Conference, p. 196. abstractKansasUSA, Mantle genesis
DS1988-0203
1988
Brookins, D.G.Erskine, D.B., Brookins, D.G., Kudo, A.M., Ward, D.B.Geochemistry of rocks with absarokititc and shoshoniti caffinities From the Absaroka volcanic field, WyomingGeological Society of America (GSA) Abstract Volume, Vol. 20, No. 3, February p. 159. AbstractWyomingBlank
DS1900-0110
1902
Brooks, A.H.Brooks, A.H.Diamonds in Alaska; April, 1902Letter To Dr. D.t.day, Chief of Mining And Mineral Resources, APRIL 3RD.United States, AlaskaDiamond Occurrences
DS200612-0130
2006
Brooks, C.Bernstein, S., Hanghoi, K., Kelemen, P., Brooks, C.Ultra depleted shallow cratonic mantle beneath West Greenland: dunitic xenoliths from Ubekendt Ejand.Contributions to Mineralogy and Petrology, Vol. 152, 3, pp. 335-347.Europe, GreenlandMineral chemistry
DS1975-0705
1978
Brooks, C.K.Brooks, C.K.,et al.An occurrence of ultrapotassic dikes in the neighbourhood of Holsetinborg West Greenland.Bulletin. Geological Society Denmark, Vol. 27, pp. 1-8.GreenlandLeucite
DS1980-0143
1980
Brooks, C.K.Gittins, J., Fawcett, J.J., Brooks, C.K., Rucklidge, J.C.Intergrowths of Nepheline Potassium Feldspar and Kalsilite Potassium Feldspar: a Re-examination of the Pseudo-leucite Problem.Contributions to Mineralogy and Petrology, Vol. 73, PP. 119-126.Greenland, BatbjergRelated Rocks, Leucite, Mineral Chemistry
DS1980-0295
1980
Brooks, C.K.Rucklidge, J.C., Brooks, C.K., Nielsen, T.F.D.Petrology of the Coastal Dykes at Tugtilik, Southern East Greenland.Greenland Geoscience., No. 3, PP. 3-17.GreenlandLamprophyre
DS1981-0102
1981
Brooks, C.K.Brooks, C.K., Fawcett, J.J., Gittins, J., Rucklidge, J.C.The Batbjerb Complex, East Greenland: a Unique Ultrapotassic Caledonian Intrusion.Canadian Journal of Earth Sciences, Vol. 18, No. 2, PP. 274-285.GreenlandLeucite
DS1996-0646
1996
Brooks, C.K.Holm, P.M., Praegel, N.O., Brooks, C.K., Nielsen, T.F.D.Lithosphere derived basaltic and lamprophyric low - from the Tertiary east Greenland rifted margin.International Geological Congress 30th Session Beijing, Abstracts, Vol. 2, p. 356.GreenlandLamprophyres
DS1998-0118
1998
Brooks, C.K.Bernstein, S., Kelemen, P.B., Brooks, C.K.Post breakup basaltic magmatism along the East Greenland Tertiary riftedmargin.Earth and Planetary Science Letters, Vol. 160, No. 3-4, Aug. pp. 845-GreenlandTectonics, Magmatism
DS1998-1270
1998
Brooks, C.K.Ryabchikov, I., Brooks, C.K., Kogarko, Nielsen, SolovovaTertiary picrites from Greenland: modelling sources and petrogenesis from melt inclusion compositions.Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1306-7.GreenlandMagnesian melts, Plume
DS1998-1491
1998
Brooks, C.K.Turkov, V.A., Kogarko, L.N., Brooks, C.K., Nielsen, T.F.Comparison of the picrite evolution from East and West Greenland ( melt inclusion data).Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1549-50.GreenlandPicrites, Magmatism
DS2000-0085
2000
Brooks, C.K.Bernstein, S., Leslie, A.G., Brooks, C.K.Tertiary alkaline volcanics in the Nunatak region: new observations and comparison with Siberian meymechites.Lithos, Vol. 53, No.1, July pp. 1-20.Greenland, Russia, SiberiaAlkaline rocks, Meymechites
DS2001-0105
2001
Brooks, C.K.Bernstein, S., Brooks, C.K., Stecher, O.Enriched component of the proto Icelandic mantle plume revealed in alkaline tertiary lavas from East GreenlandGeology, Vol. 29, No. 9, Sept. pp. 859-62.GreenlandHotspot
DS2001-0106
2001
Brooks, C.K.Bernstein, S., Brooks, C.K., Stecher, O.Enriched component of the proto-Icelandic mantle plume revealed in alkaline Tertiary lavas from East GreenlandGeology, Vol. 29, No. 9, Sept. pp. 859-62.GreenlandMelting, mixing, alkaline lavas, Nunatak region
DS2002-0651
2002
Brooks, C.K.Hansen, K., Brooks, C.K.The evolution of the East Greenland margin as revealed from fission track studiesTectonophysics, Vol. 349, No. 1-4, pp.93-111.GreenlandGeochronology, Tectonics
DS200612-0131
2006
Brooks, C.K.Bernstein, S., Hanghoj, K., Kelemen, P.B., Brooks, C.K.Ultra depleted, shallow cratonic mantle beneath West Greenland: dunitic xenoliths from Ubekendt Ejland.Contributions to Mineralogy and Petrology, in press availableEurope, GreenlandMineralogy - xenoliths not specific to diamonds
DS200712-1073
2007
Brooks, C.K.Tegner, C., Keays, R., Momme, P., Bernstein, S., Nielsen, T.F.D., Brooks, C.K.Platinum group element enrichment in the North Atlantic Igneous Province testifies to a peridotite Iceland plume.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p.225.Europe, IcelandPicrite
DS200712-1074
2007
Brooks, C.K.Tegner, C., Keays, R., Momme, P., Bernstein, S., Nielsen, T.F.D., Brooks, C.K.Platinum group element enrichment in the North Atlantic Igneous Province testifies to a peridotite Iceland plume.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p.225.Europe, IcelandPicrite
DS200512-0116
2005
Brooks, K.Brooks, K.Greenland's shining future.Geology Today, Vol. 21, 2, March pp. 69-71.Europe, GreenlandDiamond exploration
DS201112-0116
2011
Brooks, K.Brooks, K.The young Earth and the story of the early Archean rocks of West Greenland.Geology Today, Vol. 27, Jan-Feb. no. 1, pp. 15-19.Europe, GreenlandGeology
DS201909-2025
2019
Brooks, K.Brooks, K.Layered intrusions: key to fundamental planetary processes. Description of book…. Comments.Geology Today, Vol. 35, 4, pp. 146-153.China, Canada, Africalayered complexes

Abstract: A large book entitled Layered Intrusions (edited by Bernard Charlier, Olivier Namur, Rais Latypov and Christian Tegner, Springer) has been published recently. This book (almost 750 pages) has 15 contributions by 36 experts in the field. While Part I deals with subjects such as geochronology, igneous layering, textures, silicate liquid immiscibility and behaviour of precious metals in these intrusions, Part II examines six examples that are reviewed by experts: Panzhihua (China), Sept Iles (Canada), Bushveld (South Africa), Kiglapait (Labrador), Ilímaussaq (Greenland) and ophiolitic magma chambers in the Canadian Appalachians. The publication of this book has led me to consider the geology of the most famous of them all-the Skaergaard Intrusion of Greenland-and my long history of studying it.
DS202003-0331
2020
Brooks, K.Brooks, K.Perovskite.Geology Today, Vol. 36, 1, pp. 33-38. pdfMantleperovskite

Abstract: How many people, even those interested in the Earth sciences, have heard of perovskite? Yet minerals with the perovskite structure are the most abundant minerals on the Earth with a corresponding importance for our understanding of the origin, development and functioning of our planet. Furthermore, they play important roles in modern technology, including the storage of nuclear waste, in solar cells and as superconductors.
DS202011-2031
2020
Brooks, K.Brooks, K.Lithium mineralsGeology Today, Vol. 6, 5, pp. 192-197.Globallithium

Abstract: Lithium is a critical element in modern technology, and lithium minerals will play a key role in the fight against climate change. However, the demand for lithium?ion batteries is dependent on an expanding supply of primary resources. Lithium occurs in limited amounts on the Earth in a surprising diversity of mineral species, from pyroxenes to amphiboles, phyllosilicates to phosphates. This article examines the principal mineral groups likely to be a target for future exploitation.
DS1991-0835
1991
Brooks, M.Kearey, P., Brooks, M.An introduction to geophysical explorationBlackwell Scientific, 288pGlobalGeophysics, Book -ad
DS1992-1153
1992
Brooks, P.W.Osadetz, K.G., Brooks, P.W., Snowdon, L.R.Oil families and their sources in Canadian Williston Basin (southeastern Saskatchewan and southwestern Manitoba)Canadian Petroleum Geologists Bulletin, Vol. 40, No. 3, September pp.254-273Saskatchewan, ManitobaWilliston Basin, Bakken Formation
DS1997-0132
1997
Brooks, R.E.Brooks, R.E.Soliciting United States capital risks U.S. Class actionsInsight Press, United StatesEconomics, discoveries, Legal - class actions
DS1993-0166
1993
Brooks, W.E.Brooks, W.E., Orrism G.J., Wynn, G.J., Jeffrey, C.Carbonatite depositsUnited States Geological Survey (USGS) Bulletin, No. B2062, pp. 73-75.VenezuelaCarbonatite
DS1995-0216
1995
Brooks, W.E.Brooks, W.E., Tosdal, R.M., Nuflez, F.J.Gold and diamond resources of the Icabaru Sur study area, Estado BolivarU.s. Geological Survey Bulletin., No. 2124-A, Chapter L.Venezuela, BolivarDiamond resources, Deposit -Icabaru Sur area
DS1910-0338
1913
Broom, R.Broom, R.A New Extinct Giant Pig from the Diamond Gravels of Windsorten South Africa.Records Albany Museum (grahamstown), Vol. 4, PP. 167-168.South Africa, Cape Province, WindsortonAlluvial Diamond Placers, Palaeontology
DS1910-0339
1913
Broom, R.Broom, R.On Some Fossil Fishes from the Diamond Bearing Pipes of Kimberley.Cape Town: Royal Society. Transactions, Vol. 3, P. 399.South Africa, Griqualand WestPalaeontology, Kimberlite Mines And Pipes
DS1989-0537
1989
BroomeGreen, A.G., Milkereit, B., Percival, J.A., Kurtz, R.D., BroomeIntegrated geophysical lithoprobe studies of the Kapuskasing structureGeological Society of Canada (GSC) Forum 1989, P. 11. abstractOntarioGeophysics, Kapuskasing
DS1993-1670
1993
BroomeVilleneuve, M., Ross, Theriault, Miles, Parrish, BroomeTectonic subdivision and uranium-lead (U-Pb) geochronology of the crystalline basement Of the Alberta basin.Geological Survey of Canada (GSC), Bulletin. No. 447, 86p.Alberta, Western CanadaTectonics, Geochronology
DS1992-0084
1992
Broome, H.J.Baril, D., Renez, A., Thompson, P.H., Broome, H.J., Barrie, C.T.NATMAP Slave project: integrating LANDSAT, ERSI Radar, aeromagnetic and geological dat a for regional mappingNorthwest Territories Geoscience Forum held November 25, 26th. 1992, poster, AbstractNorthwest TerritoriesMapping, GIS
DS1994-1151
1994
Broome, H.J.McGrath, P.H., Broome, H.J.A gravity model for the Sudbury structure along the Lithoprobe seismiclineGeophysical Research Letters, Vol. 21, No. 10, May 15, pp. 955-958OntarioGeophysics -seismics, Deposit - Sudbury
DS1996-0163
1996
Broome, H.J.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
DS1999-0095
1999
Broome, H.J.Broome, H.J., Viljoen, D.Application of digital methodology to the NATMAP Shield Margin ProjectCanadian Journal of Earth Sciences, Vol. 36, No. 2, Feb. pp. 161-73.Manitoba, SaskatchewanLithoprobe, Geophysics - seismics
DS1985-0090
1985
Broome, J.Broome, J., Simard, R., Teskey, D.Presentation of magnetic anomaly map dat a by stereo projection at magneticshadowgrams.Canadian Journal of Earth Sciences, Vol. 22, pp. 311-14.Northwest TerritoriesLockhart River, Thelon River, Geophysics - Magnetics
DS1988-0088
1988
Broome, J.Broome, J.An IBM compatible microcomputer workstation for modeling and imaging potential field dataComputers and Geosciences, Vol. 14, No. 5, pp. 659-666. Database # 17569GlobalComputer, Program- Field data
DS1988-0221
1988
Broome, J.Forsyth, D.A., Thomas, M.D., Broome, J., Abbinett, D., Halpenny, J.Regional geophysics of the central metasedimentary beltGeological Society of America (GSA) Abstract Volume, Vol. 20, No. 5, March p. 344. abstractGlobalBlank
DS1989-0181
1989
Broome, J.Broome, J., Turner, C.Additions and improvements to microcomputer workstation software for potential field interpretationGeological Survey of Canada Current Research, Paper No. 89-1F, pp.1-5GlobalComputer -Program, Field interpretation
DS1990-0684
1990
Broome, J.Henderson, J.R., Broome, J.Geometry and kinematics of Wager shear zone interpreted from structural fabrics and magnetic data.Canadian Journal of Earth Sciences, Vol. 27, pp. 590-604.GlobalTectonics, Geophysics - magnetics
DS1991-0180
1991
Broome, J.Broome, J.G3D: a three dimensional gravity modelling program for IBM compatiblemicrocomputersGeological Survey of Canada Open File, No. 2427, 55p. and disc. total $ 25.00GlobalComputer, Program -G3D gravity
DS1993-0167
1993
Broome, J.Broome, J., Brodaric, B., Viljoen, D., Baril, D.The NATMAP digital geoscience data-management systemComputers and Geosciences, Vol. 19, No. 10, pp. 1501-1516GlobalComputers, Program -NATMAP data management system
DS1993-0168
1993
Broome, J.Broome, J., Lucas, S., Thomas, M.Bouguer gravity map of the sub-Phanerozoic portion of the Flin Flon belt, Manitoba and SaskatchewanGeological Survey of Canada, Open file, No. 2657, 1 mapManitoba, SaskatchewanGeophysics -gravity, Open File -ad
DS1994-0213
1994
Broome, J.Broome, J., Vijoen, D.CD ROM distribution of intergrated geoscience dat a sets for the NATMAP shield margin project area, Manitoba and Saskatchewan.Geological Survey of Canada Open Forum January 17-19th. Abstracts only, p. 12.Manitoba, SaskatchewanGIS, Craton
DS200712-0113
2007
Broome, J.Broome, J., Cox, S.Geoscience information management and access: evolution of a key enabler for exploration success.Proceedings of Exploration 07 edited by B. Milkereit, pp. 97-108.TechnologyData management - review
DS201412-0075
2014
Broom-Fendley, S.Broom-Fendley, S.Late stage apatite: a potential heavy REE enriched co-product of light REE minerals in carbonatites.ima2014.co.za, AbstractCarbonatite
DS201412-0076
2014
Broom-Fendley, S.Broom-Fendley, S.The Songwe-Hill carbonatite, Malawi: new mapping geochemistry and U Pb dating.ima2014.co.za, PosterAfrica, MalawiCarbonatite
DS201604-0595
2016
Broom-Fendley, S.Broom-Fendley, S., Styles, M.T., Appleton, J.D., Gunn, G., Wall, F.Evidence for dissolution reprecipitation of apatite and preferential LREE mobility in carbonatite derived late stage hydrothermal processes.American Mineralogist, Vol. 101, pp. 596-611.Africa, MalawiCarbonatite

Abstract: The Tundulu and Kangankunde carbonatite complexes in the Chilwa Alkaline Province, Malawi, contain late-stage, apatite-rich lithologies termed quartz-apatite rocks. Apatite in these rocks can reach up to 90 modal% and displays a distinctive texture of turbid cores and euhedral rims. Previous studies of the paragenesis and rare earth element (REE) content of the apatite suggest that heavy REE (HREE)-enrichment occurred during the late-stages of crystallization. This is a highly unusual occurrence in intrusions that are otherwise light REE (LREE) enriched. In this contribution, the paragenesis and formation of the quartz-apatite rocks from each intrusion is investigated and re-evaluated, supported by new electron microprobe (EPMA) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) data to better understand the mechanism of HREE enrichment. In contrast to the previous work at Tundulu, we recognize three separate stages of apatite formation, comprising an “original” euhedral apatite, “turbid” apatite, and “overgrowths” of euhedral late apatite. The crystallization of synchysite-(Ce) is interpreted to have occurred subsequent to all phases of apatite crystallization. The REE concentrations and distributions in the different minerals vary, but generally higher REE contents are found in later-stage apatite generations. These generations are also more LREE-enriched, relative to apatite that formed earlier. A similar pattern of increasing LREE-enrichment and increased REE concentrations toward later stages of the paragenetic sequence is observed at Kangankunde, where two generations of apatite are observed, the second showing higher REE concentrations, and relatively higher LREE contents. The changing REE distribution in the apatite, from early to late in the paragenetic sequence, is interpreted to be caused by a combination of dissolution-reprecipitation of the original apatite and the preferential transport of the LREE complexes by F- and Cl-bearing hydrothermal fluids. Successive pulses of these fluids transport the LREE out of the original apatite, preferentially re-precipitating it on the rim. Some LREE remained in solution, precipitating later in the paragenetic sequence, as synchysite-(Ce). The presence of F is supported by the F content of the apatites, and presence of REE-fluorcarbonates. Cl is not detected in the apatite structure, but the role of Cl is suggested from comparison with apatite dissolution experiments, where CaCl2 or NaCl cause the reprecipitation of apatite without associated monazite. This study implies that, despite the typically LREE enriched nature of carbonatites, significant degrees of hydrothermal alteration can lead to certain phases becoming residually enriched in the HREE. Although at Tundulu the LREE-bearing products are re-precipitated relatively close to the REE source, it is possible that extensive hydrothermal activity in other carbonatite complexes could lead to significant, late-stage fractionation of the REE and the formation of HREE minerals.
DS201605-0880
2016
Broom-Fendley, S.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.
DS201609-1707
2016
Broom-Fendley, S.Broom-Fendley, S., Heaton, T., Wall, F., Gunn, G.Tracing the fluid source of heavy REE mineralization in carbonatites using a novel method of oxygen isotope analysis in apatite: the example of Songwe Hill, Malawi.Chemical Geology, Vol. 440, pp. 275-287.Africa, MalawiCarbonatite

Abstract: Stable (C and O) isotope data from carbonates are one of the most important methods used to infer genetic processes in carbonatites. However despite their ubiquitous use in geological studies, it is suspected that carbonates are susceptible to dissolution-reprecipitation and isotopic resetting, especially in shallow intrusions, and may not be the best records of either igneous or hydrothermal processes. Apatite, however, should be much less susceptible to these resetting problems but has not been used for O isotope analysis. In this contribution, a novel bulk-carbonatite method for the analysis of O isotopes in the apatite PO4 site demonstrates a more robust record of stable isotope values. Analyses of apatite from five carbonatites with magmatic textures establishes a preliminary Primary Igneous Apatite (PIA) field of ?18O = + 2.5 to + 6.0‰ (VSMOW), comparable to Primary Igneous Carbonatite (PIC) compositions from carbonates. Carbonate and apatite stable isotope data are compared in 10 carbonatite samples from Songwe Hill, Malawi. Apatite is heavy rare earth element (HREE) enriched at Songwe and, therefore, oxygen isotope analyses of this mineral are ideal for understanding HREE-related mineralisation in carbonatites. Carbonate C and O isotope ratios show a general trend, from early to late in the evolution, towards higher ?18O values (+ 7.8 to + 26.7‰, VSMOW), with a slight increase in ?13C (? 4.6 to ? 0.1‰, VPDB). Oxygen isotope ratios from apatite show a contrary trend, decreasing from a PIA field towards more negative values (+ 2.5 to ? 0.7‰, VSMOW). The contrasting results are interpreted as the product of the different minerals recording fluid interaction at different temperatures and compositions. Modelling indicates the possibility of both a CO2 rich fluid and mixing between meteoric and deuteric waters. A model is proposed where brecciation leads to depressurisation and rapid apatite precipitation. Subsequently, a convection cell develops from a carbonatite, interacting with surrounding meteoric water. REE are likely to be transported in this convection cell and precipitate owing to decreasing salinity and/or temperature.
DS201701-0004
2016
Broom-Fendley, S.Broom-Fendley, S., Brady, A.E., Wall, F., Gunn, G., Dawes, W.REE minerals at the Songwe Hill carbonatite, Malawi: HREE enrichment in late stage apatite.Ore Geology Reviews, Vol. 81, pp. 23-41.Africa, MalawiCarbonatite

Abstract: Compared to all published data from carbonatites and granitoids, the fluorapatite compositions in the Songwe Hill carbonatite, determined by EPMA and LA ICP-MS, have the highest heavy (H)REE concentration of any carbonatite apatite described so far. A combination of this fluorapatite and the REE fluorocarbonates, synchysite-(Ce) and parisite-(Ce), which are the other principal REE bearing minerals at Songwe, gives a REE deposit with a high proportion of Nd and a higher proportion of HREE (Eu-Lu including Y) than most other carbonatites. Since Nd and HREE are currently the most sought REE for commercial applications, the conditions that give rise to this REE profile are particularly important to understand. Multiple apatite crystallisation stages have been differentiated texturally and geochemically at Songwe and fluorapatite is divided into five different types (Ap-0-4). While Ap-0 and Ap-1 are typical of apatite found in fenite and calcite-carbonatite, Ap-2, -3 and -4 are texturally atypical of apatite from carbonatite and are progressively HREE-enriched in later paragenetic stages. Ap-3 and Ap-4 exhibit anhedral, stringer-like textures and their REE distributions display an Y anomaly. These features attest to formation in a hydrothermal environment and fluid inclusion homogenisation temperatures indicate crystallisation occurred between 200-350 °C. Ap-3 crystallisation is succeeded by a light (L)REE mineral assemblage of synchysite-(Ce), strontianite and baryte. Finally, late-stage Ap-4 is associated with minor xenotime-(Y) mineralisation and HREE-enriched fluorite. Fluid inclusions in the fluorite constrain the minimum HREE mineralisation temperature to approximately 160 °C. A model is suggested where sub-solidus, carbonatite-derived, (carbo)-hydrothermal fluids remobilise and fractionate the REE. Chloride or fluoride complexes retain LREE in solution while rapid precipitation of apatite, owing to its low solubility, leads to destabilisation of HREE complexes and substitution into the apatite structure. The LREE are retained in solution, subsequently forming synchysite-(Ce). This model will be applicable to help guide exploration in other carbonatite complexes.
DS201707-1310
2017
Broom-Fendley, S.Broom-Fendley, S., Brady, A.E., Horstwood, M.S.A., Woolley, A.R., Mtegha, J., Wall, F., Dawes, W., Gunn, G.Geology, geochemistry and geochronology of the Songwe Hill carbonatite, Malawi.Journal of African Earth Sciences, Vol. 134, pp. 10-23.Africa, Malawicarbonatite - Songwe Hill

Abstract: Songwe Hill, Malawi, is one of the least studied carbonatites but has now become particularly important as it hosts a relatively large rare earth deposit. The results of new mapping, petrography, geochemistry and geochronology indicate that the 0.8 km diameter Songwe Hill is distinct from the other Chilwa Alkaline Province carbonatites in that it intruded the side of the much larger (4 x 6 km) and slightly older (134.6 ± 4.4 Ma) Mauze nepheline syenite and then evolved through three different carbonatite compositions (C1–C3). Early C1 carbonatite is scarce and is composed of medium–coarse-grained calcite carbonatite containing zircons with a U–Pb age of 132.9 ± 6.7 Ma. It is similar to magmatic carbonatite in other carbonatite complexes at Chilwa Island and Tundulu in the Chilwa Alkaline Province and others worldwide. The fine-grained calcite carbonatite (C2) is the most abundant stage at Songwe Hill, followed by a more REE- and Sr-rich ferroan calcite carbonatite (C3). Both stages C2 and C3 display evidence of extensive (carbo)-hydrothermal overprinting that has produced apatite enriched in HREE (<2000 ppm Y) and, in C3, synchysite-(Ce). The final stages comprise HREE-rich apatite fluorite veins and Mn-Fe-rich veins. Widespread brecciation and incorporation of fenite into carbonatite, brittle fracturing, rounded clasts and a fenite carapace at the top of the hill indicate a shallow level of emplacement into the crust. This shallow intrusion level acted as a reservoir for multiple stages of carbonatite-derived fluid and HREE-enriched apatite mineralisation as well as LREE-enriched synchysite-(Ce). The close proximity and similar age of the large Mauze nepheline syenite suggests it may have acted as a heat source driving a hydrothermal system that has differentiated Songwe Hill from other Chilwa carbonatites.
DS201709-1964
2017
Broom-Fendley, S.Broom-Fendley, S., O'Neill, M., Wall, F.Are carbonate-fluorapatite rocks in carbonatite complexes the result of hydrothermal processes or weathering? Sokli, KovdorGoldschmidt Conference, abstract 1p.Europe, Finland, Russiacarbonatites, Sokli, Kovdor

Abstract: Carbonate-fluorapatite (also known as staffelite and/or francolite) can become a rock-forming mineral in the upper levels of some carbonatite complexes, such as at Sokli, Finland, and Kovdor, Russia. Carbonate-fluorapatite rocks are recognised as an important phosphate resource, but there is little consensus on their genesis. Two principal models are favoured: (1) a hydrothermal origin, from a late-stage, carbonatite-derived fluid or, (2) formation through supergene dissolution of carbonate and re-precipitation of apatite. In this contribution, we have investigated the texture and composition of different carbonate-fluorapatite generations (using cathodoluminescence microsopy and LA ICP MS) in order to evaluate the aforementioned formation mechanisms. Four carbonate-fluorapatite growth generations were identified: (1) primary apatite grains, with a rounded/euhedral habit and luminescing purple; (2) strongly luminescent epitactic rims on primary grains; (3) ‘aggregate’ apatite, forming a fine-grained groundmass, typically luminescing blue; (4) botryoidal growth zones, commonly luminescing blue, but in places green or non-luminescent. REE contents in secondary carbonate-fluorapatite generations (2–4) are markedly low, with some analyses below detection limit (typically <1 ppm). Furthermore, many of these analyses exhibit both positive and negative Ce anomalies, indicative of an oxidising environment. The low REE contents of the different carbonatefluorapatite generations indicates that negligible REE transfer occurred between different growth events, contrasting with hydrothermal apatite in other carbonatite complexes. Furthermore, the lack of any significant fractionation between subsequent carbonate-fluorapatite generations is interpreted as circumstantial evidence that these rocks did not form through hydrothermal alteration. This is compounded by the presence of a Ce anomaly, which is commonly interpreted as a weathering feature. While hydrothermal formation under different conditions, causing complete removal of the REE, cannot be ruled out, we conclude that the locations were, most-likely, formed in a supergene environment. Continued investigation of weathered carbonate-fluorapatite material from other localities is underway to assess this conclusion.
DS201709-2070
2017
Broom-Fendley, S.Wall., F., Al Ali, S., Rollinson, G., Fitzpatrick, R., Dawes, W., Broom-Fendley, S.Geochemistry and mineralogy of rare earth processing.Goldschmidt Conference, abstract 1p.Africa, Malawicarbonatite - Songwe Hill

Abstract: The geochemistry and mineralogy of REE deposits is diverse, from carbonatite-related deposits, alkaline rocks, mineral sands and ion adsorption clays to potential by-products of phosphate and bauxite, and reuse of waste materials. Despite the large number of prospects that have been explored recently, very little additional REE production has started. A major challenge is to design effective, cost-efficient and environmentally-friendly processing and extraction. Processing flow sheets have to be constructed carefully for each deposit. Translating geochemistry and mineralogy studies, including quantitative mineralogy results, into processing characteristics can be illustrated using results from the Songwe Hill carbonatite, Malawi. Combining results with other published data then allows us to make some general conclusions about the common REE ore minerals and their geological environment, including the REE fluorcarbonate series, monazite and xenotime. The use of chemicals for REE extraction is often the largest environmental burden to mitigate. A new issue is that certain REE, such as Ce, are in oversupply, and are not being recovered in some proposed processing flowsheets. It will be important to understand the environmental and commercial implications of this development.
DS201712-2676
2017
Broom-Fendley, S.Broom-Fendley, S., Wall, F., Spiro, B., Ullmann, C.V.Deducing the source and composition of rare earth mineralising fluids in carbonatites: insights from isotopic ( C,O,87Sr/86SR) dat a from Kangankunde, Malawi.Contributions to Mineralogy and Petrology, Vol. 172, 96Africa, Malawicarbonatite

Abstract: Carbonatites host some of the largest and highest grade rare earth element (REE) deposits but the composition and source of their REE-mineralising fluids remains enigmatic. Using C, O and 87Sr/86Sr isotope data together with major and trace element compositions for the REE-rich Kangankunde carbonatite (Malawi), we show that the commonly observed, dark brown, Fe-rich carbonatite that hosts REE minerals in many carbonatites is decoupled from the REE mineral assemblage. REE-rich ferroan dolomite carbonatites, containing 8-15 wt% REE2O3, comprise assemblages of monazite-(Ce), strontianite and baryte forming hexagonal pseudomorphs after probable burbankite. The 87Sr/86Sr values (0.70302-0.70307) affirm a carbonatitic origin for these pseudomorph-forming fluids. Carbon and oxygen isotope ratios of strontianite, representing the REE mineral assemblage, indicate equilibrium between these assemblages and a carbonatite-derived, deuteric fluid between 250 and 400 °C (?18O + 3 to + 5‰VSMOW and ?13C ? 3.5 to ? 3.2‰VPDB). In contrast, dolomite in the same samples has similar ?13C values but much higher ?18O, corresponding to increasing degrees of exchange with low-temperature fluids (< 125 °C), causing exsolution of Fe oxides resulting in the dark colour of these rocks. REE-rich quartz rocks, which occur outside of the intrusion, have similar ?18O and 87Sr/86Sr to those of the main complex, indicating both are carbonatite-derived and, locally, REE mineralisation can extend up to 1.5 km away from the intrusion. Early, REE-poor apatite-bearing dolomite carbonatite (beforsite: ?18O + 7.7 to + 10.3‰ and ?13C ?5.2 to ?6.0‰; 87Sr/86Sr 0.70296-0.70298) is not directly linked with the REE mineralisation.
DS201906-1278
2019
Broom-Fendley, S.Broom-Fendley, S., Smith, M., Andrade, M.B., Ray, S., Banks, D.A., Loye, E., Atencio, D., Pickles, J.R., Wall, F.Sulphate bearing monazite (Ce) from silicified dolomite carbonatite, Eureka, Namibia: substitution mechanisms, redox state and HREE enrichment.3rd International Critical Metals Meeting held Edinburgh, 1p. Abstract p. 51.Africa, Namibiadeposit - Eureka
DS201906-1291
2019
Broom-Fendley, S.Elliott, H.A.L., Broom-Fendley, S., Wall, F.Fenite exploration criteria surrounding carbonatite hosted critical metal deposits.3rd International Critical Metals Meeting held Edinburgh, 1p. Abstract p. 38.Europe, Finlanddeposit - Sokli
DS201909-2028
2019
Broom-Fendley, S.Cangelosi, D., Broom-Fendley, S., Banks, D., Morgan, D., Yardley, B.LREE redistribution during hydrothermal alteration at the Okorusu carbonatite complex, Namibia.Mineralogical Magazine, in press available 54p. PdfAfrica, Namibiacarbonatite - Okorusu

Abstract: The Cretaceous Okorusu carbonatite, Namibia, includes diopside-bearing and pegmatitic calcite carbonatites, both exhibiting hydrothermally altered mineral assemblages. In unaltered carbonatite, REE, Sr and Ba are largely hosted by calcite and fluorapatite. However, in hydrothermally altered carbonatites, small (< 50 ?m) parisite-(Ce) grains are the dominant REE host, while Ba and Sr are hosted in baryte, celestine, strontianite and witherite. Hydrothermal calcite has a much lower trace element content than the original, magmatic calcite. Despite the low REE contents of the hydrothermal calcite, the REE patterns are similar to those of parisite-(Ce), and magmatic minerals and mafic rocks associated with the carbonatites. These similarities suggest that hydrothermal alteration remobilised REE from magmatic minerals, predominantly calcite, without significant fractionation or addition from an external source. Ba and Sr released during alteration were mainly reprecipitated as sulfates. The breakdown of magmatic pyrite into Fe-hydroxide is inferred to be the main source of sulfate. The behaviour of sulfur suggests that the hydrothermal fluid was somewhat oxidising and it may have been part of a geothermal circulation system. Late hydrothermal massive fluorite replaced the calcite carbonatites at Okorusu and resulted in extensive chemical change, suggesting continued magmatic contributions to the fluid system.
DS202003-0332
2020
Broom-Fendley, S.Broom-Fendley, S., Smith, M.P., Andrade, M.B., Ray, S., Banks, D.A., Loye, E., Antencio, D., Pickles, J.P., Wall, F.Sulfur bearing monzazite (Ce) from the Eureka carbonatite, Namibia: oxidation state, substitution mechanism, and formation conditions.Mineralogical Magazine, pp. 1-14, pdfAfrica, Namibiacarbonatite, REE

Abstract: Sulfur-bearing monazite-(Ce) occurs in silicified carbonatite at Eureka, Namibia, forming rims up to ~0.5 mm thick on earlier-formed monazite-(Ce) megacrysts. We present X-ray photoelectron spectroscopy data demonstrating that sulfur is accommodated predominantly in monazite-(Ce) as sulfate, via a clino-anhydrite-type coupled substitution mechanism. Minor sulfide and sulfite peaks in the X-ray photoelectron spectra, however, also indicate that more complex substitution mechanisms incorporating S2 and S4+ are possible. Incorporation of S6+ through clino-anhydrite-type substitution results in an excess of M2+ cations, which previous workers have suggested is accommodated by auxiliary substitution of OH for O2. However, Raman data show no indication of OH, and instead we suggest charge imbalance is accommodated through F substituting for O2. The accommodation of S in the monazite-(Ce) results in considerable structural distortion that may account for relatively high contents of ions with radii beyond those normally found in monazite-(Ce), such as the heavy rare earth elements, Mo, Zr and V. In contrast to S-bearing monazite-(Ce) in other carbonatites, S-bearing monazite-(Ce) at Eureka formed via a dissolutionprecipitation mechanism during prolonged weathering, with S derived from an aeolian source. While large S-bearing monazite-(Ce) grains are likely to be rare in the geological record, formation of secondary S-bearing monazite-(Ce) in these conditions may be a feasible mineral for dating palaeo-weathering horizons.
DS202108-1275
2021
Broom-Fendley, S.Broom-Fendley, S., Elliott, H.A.L., Beard, C.D., Wall, F., Armitage, P.E.B., Brady, A.E., Deady, A.E., Dawes, W.Enrichment of heavy REE and Th in carbonatite-derived fenite breccia.Geological Magazine, in press available Africa, Malawideposit - Songwe Hill

Abstract: Enrichment of the heavy rare earth elements (HREE) in carbonatites is rare as carbonatite petrogenesis favours the light (L)REE. We describe HREE enrichment in fenitized phonolite breccia, focusing on small satellite occurrences 1-2 km from the Songwe Hill carbonatite, Malawi. Within the breccia groundmass, a HREE-bearing mineral assemblage comprises xenotime, zircon, anatase/rutile and minor huttonite/thorite, as well as fluorite and apatite. A genetic link between HREE mineralization and carbonatite emplacement is indicated by the presence of Sr-bearing carbonate veins, carbonatite xenoliths and extensive fenitization. We propose that the HREE are retained in hydrothermal fluids which are residually derived from a carbonatite after precipitation of LREE minerals. Brecciation provides a focusing conduit for such fluids, enabling HREE transport and xenotime precipitation in the fenite. Continued fluid-rock interaction leads to dissolution of HREE-bearing minerals and further precipitation of xenotime and huttonite/thorite. At a maximum Y content of 3100 µg g?1, HREE concentrations in the presented example are not sufficient to constitute ore, but the similar composition and texture of these rocks to other cases of carbonatite-related HREE enrichment suggests that all form via a common mechanism linked to fenitization. Precipitation of HREE minerals only occurs where a pre-existing structure provides a focusing conduit for fenitizing fluids, reducing fluid - country-rock interaction. Enrichment of HREE and Th in fenite breccia serves as an indicator of fluid expulsion from a carbonatite, and may indicate the presence of LREE mineralization within the source carbonatite body at depth.
DS202203-0334
2021
Broom-Fendley, S.Anenburg, M., Broom-Fendley, S., Chen, W.Formation of rare earth deposits in carbonatites. Burbankite, alkaline complexes.Elements, Vol. 17, 327-232.GlobalRare earths, REE

Abstract: Carbonatites and related rocks are the premier source for light rare earth element (LREE) deposits. Here, we outline an ore formation model for LREE-mineralised carbonatites, reconciling field and petrological observations with recent experimental and isotopic advances. The LREEs can strongly partition to carbonatite melts, which are either directly mantle-derived or immiscible from silicate melts. As carbonatite melts evolve, alkalis and LREEs concentrate in the residual melt due to their incompatibility in early crystal-lising minerals. In most carbonatites, additional fractionation of calcite or ferroan dolomite leads to evolution of the residual liquid into a mobile alkaline “brine-melt” from which primary alkali REE carbonates can form. These primary carbonates are rarely preserved owing to dissolution by later fluids, and are replaced in-situ by monazite and alkali-free REE-(fluor)carbonates.-
DS201909-2021
2019
Broom-Findlay, S.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.
DS202106-0925
2021
Broom-Findley, S.Broom-Findley, S., Siegfried, P.R., Wall, F., O'Neill, M., Brooker, R.A., Fallon, E.K., Pickles, J.R., Banks, D.A.The origin and composition of carbonatite-derived carbonate bearing fluorapatite deposits.Mineralium Deposita, Vol. 56, pp. 863-884.Globaldeposit - Kovdor, Sokli, Bukusu, Catalao 1, Glenover

Abstract: Carbonate-bearing fluorapatite rocks occur at over 30 globally distributed carbonatite complexes and represent a substantial potential supply of phosphorus for the fertiliser industry. However, the process(es) involved in forming carbonate-bearing fluorapatite at some carbonatites remain equivocal, with both hydrothermal and weathering mechanisms inferred. In this contribution, we compare the paragenesis and trace element contents of carbonate-bearing fluorapatite rocks from the Kovdor, Sokli, Bukusu, Catalão I and Glenover carbonatites in order to further understand their origin, as well as to comment upon the concentration of elements that may be deleterious to fertiliser production. The paragenesis of apatite from each deposit is broadly equivalent, comprising residual magmatic grains overgrown by several different stages of carbonate-bearing fluorapatite. The first forms epitactic overgrowths on residual magmatic grains, followed by the formation of massive apatite which, in turn, is cross-cut by late euhedral and colloform apatite generations. Compositionally, the paragenetic sequence corresponds to a substantial decrease in the concentration of rare earth elements (REE), Sr, Na and Th, with an increase in U and Cd. The carbonate-bearing fluorapatite exhibits a negative Ce anomaly, attributed to oxic conditions in a surficial environment and, in combination with the textural and compositional commonality, supports a weathering origin for these rocks. Carbonate-bearing fluorapatite has Th contents which are several orders of magnitude lower than magmatic apatite grains, potentially making such apatite a more environmentally attractive feedstock for the fertiliser industry. Uranium and cadmium contents are higher in carbonate-bearing fluorapatite than magmatic carbonatite apatite, but are much lower than most marine phosphorites.
DS1992-0172
1992
Brophy, J.A.Brophy, J.A.Exploration overview 1991 Northwest Territories. Brief commentary on Lac deGras areanorthwest Territories Geology Division, November 1991, Revised March 1992, p. 9Northwest TerritoriesDiamond exploration activity, Lac de Gras area
DS201112-0224
2011
Broscoe, D.Cummings, D.I., Broscoe, D., Kjarsgaard, B.A., Lesemann, J., Russell, H.A.J., Sharpe, D.R.Eskers as mineral exploration tools: how to sample eskers and interpret data.Yellowknife Geoscience Forum Abstracts for 2011, Poster abstract p. 95-96.Canada, Northwest TerritoriesEsker related literature
DS201709-2038
2017
Broska, I.Nasdala, L., Broska, I., Harlov, D.E., Macdonald, R.Recent progress in the study of accessory minerals. Outline of special volume.Mineralogy and Petrology, Vol. 111, 4, pp. 431-433.Technologymineralogy

Abstract: Accessory minerals are a common species in igneous and metamorphic rocks that are not considered characteristic of the host rock and hence do not affect its root name. Accessories tend to be complex in terms of their chemical and isotopic composition and their structural state. In spite of not being major rock constituents, they are, however, of enormous petrologic interest as they contain a record of the formation and post-formation history of their host rock. The study of accessory minerals hence has increased continuously during the past years, and still increases (Fig. 1). Recent progress is driven by new analytical opportunities of (in situ) micro-techniques. More and more the internal textures, that is, elemental, isotopic, and/or structural distribution patterns within individual grains, have come into the focus of researchers; a few examples are compiled in Fig. 2.
DS1988-0185
1988
Brothers, S.C.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
DS2003-0934
2003
Brotszu, P.Melluso, L., Morra, V., Brotszu, P., D'Antonio, M., Bennio, L.Petrogenesis of the Late Cretaceous tholeiitic magmatism in the passive margins ofGeological Society of America Special Paper, No. 362, chapter 6.MadagascarMagmatism
DS201112-0391
2011
BrotzuGuarino, V., Azzone, Brotzu, De Barros, Melluso, L., Morbidelli, Ruberti, Tassinari, BrilliMagmatism and fenitization in the Cretaceous potassium alkaline carbonatitic complex of Ipanema, Sao Paulo State, Brazil.Mineralogy and Petrology, In press available,South America, BrazilCarbonatite
DS1993-0169
1993
Brotzu, P.Brotzu, P., et al.Petrology and geochemistry of the Passa Quatro alkaline complex, southeastern BrasilJournal of South American Earth Sciences, Vol. 6, No. 4, November pp. 237-252BrazilAlkaline complex, alkaline rocks, Geochemistry
DS1997-0133
1997
Brotzu, P.Brotzu, P., Gomes, C.B., Melluso, L., et al.Petrogenesis of coexisting SiO2 undersaturated to SiO2 Over saturated felsic igneous rocks: alkaline complex..Lithos, Vol. 40, No. 2-4, July, pp. 133-156.BrazilAlkaline rocks, Itataia area
DS2000-0650
2000
Brotzu, P.Melluso, L., Morra, V., Bennio, L., Brotzu, P., RicciPetrology and geochemistry of the Tamatave dike swarm (Madagascar Cretaceous igneous province)Igc 30th. Brasil, Aug. abstract only 1p.MadagascarDike swarm
DS2000-0685
2000
Brotzu, P.Morbidelli, L., Gomes, C.B., Brotzu, P., et al.The Pariquera Acu K-alkaline complex and southern Brasil lithospheric mantle source characteristics.Journal of Asian Earth Science, Vol. 18, No.2, Apr. pp. 129-50.BrazilAlkaline rocks, Lithosphere
DS2001-0770
2001
Brotzu, P.Melluso, L., Morra, V., Brotzu, P., Mahoney, J.J.The Cretaceous igneous province of Madagascar: geochemistry and petrogenesis of lavas and dykes...Journal of Petrology, Vol. 42, No. 7, July, pp. 1249-78.Madagascar, central westernIgneous rocks - petrology
DS2003-0935
2003
Brotzu, P.Melluso, L., Morra, V., Brotzu, P., Franciosi, L., Lieberknecht, A.M.P., BennioGeochemical provinciality in the Cretaceous basaltic magmatism of northernJournal of the Geological Society of London, Vol. 160, 3, pp. 477-488.MadagascarBlank
DS2003-0936
2003
Brotzu, P.Melluso, L., Morra, V., Brotzu, P., Franciosi, L., Petteruti Lieberknecht, A.M.Geochemical provinciality in the Cretaceous basaltic magmatism of northernJournal of the Geological Society of London, Vol. 160, 3, May pp. 477-88.MadagascarMagmatism - not specific to diamonds
DS200412-1295
2003
Brotzu, P.Melluso, L., Morra, V., Brotzu, P., Franciosi, L., Lieberknecht, A.M.P., Bennio, L.Geochemical provinciality in the Cretaceous basaltic magmatism of northern Madagascar: mantle source immplications.Journal of the Geological Society, Vol. 160, 3, pp. 477-488.Africa, MadagascarGeochemistry - not specific to diamonds
DS200412-1296
2003
Brotzu, P.Melluso, L., Morra, V., Brotzu, P., Franciosi, L., Petteruti Lieberknecht, A.M., Benno, L.Geochemical provinciality in the Cretaceous basaltic magmatism of northern Madagascar: mantle source implications.Journal of the Geological Society, Vol. 160, 3, May pp. 477-88.Africa, MadagascarMagmatism - not specific to diamonds
DS200712-0114
2007
Brotzu, P.Brotzu, P., Melluso, L., Bennio, L., Gomes, Lustrino, Morbidelli, Morra, Ruberti, Tassarini, D'AntonioPetrogenesis of the Early Cenozoic potassic alkaline complex of Morro de Sao Joao, southeastern Brazil.Journal of South American Earth Sciences, Vol. 24, 1, June pp. 93-115.South America, BrazilAlkalic
DS200812-0738
2008
Brotzu, P.Melluso, L., Lustrino, M., Ruberti, E., Brotzu, P., Barros Gomes, C., Morbidelli, Morra, Svisero, AmelioMajor and trace element composition of olivine perovskite, clinopyroxene, Cr Fe Ti oxides, phlogopite and host kamafugites and kimberlites, Alto Paranaiba,Canadian Mineralogist, Vol. 46, no. 2 Feb. pp. 19-40.South America, BrazilKamafugite, kimberlite
DS201012-0460
2010
Brotzu, P.Lustrino, M., Marazzo, M., Melluso, L., Tassinari, C.C.G., Brotzu, P., Gomes, C.B., Morbidelli, RubertiPetrogenesis of early Cretaceous silicic volcanism in se Uruguay: the role of mantle and crustal sources.Geochemical Journal, Vol. 44, 1, pp. 1-22.South America, UruguayRhyolites - not specific diamonds - backgrounder
DS201212-0267
2012
Brotzu, P.Guarino, V., Guitarrari Azzone, R., Brotzu, P., Celso de Barros Gomes, Melluso, L., Morbidelli, L.,Ruberti, E.,Tassinari, C., Brilli, M.Magmatism and fenitization in the Cretaceous potassium-alkaline-carbonatitic complex of Ipanema Sao Paulo State, Brazil.Mineralogy and Petrology, Vol. 104, 1-2, pp. 43-61.South America, BrazilCarbonatite
DS201212-0268
2012
Brotzu, P.Guarino, V., Wu, F-Y., Lustrino, M., Melluso, L.,Brotzu, P., De Barros Gomes, C., Ruberti, E., Tassarini, C.C.G., Svisero, D.P.U Pb ages, Sr Nd isotope geochemistry, and petrogenesis of kimberlites, kamafugites and phlogopite picrites of the Alto Paranaiba Igneous Province, Brazil.Chemical Geology, in press available 57p.South America, BrazilGeochronology
DS201312-0350
2013
Brotzu, P.Guarino, V., Wu, F-Y., Lustrino, M., Melluso, L., Brotzu, P., Barros Gomes, C.de, Ruberti, E., Tassarini, C.C.G., Svisero, D.P.U-Pb ages, Sr, Nd isotope geochemistry, and petrogenesis of kimberlites, kamafugites and phlogopte-picrites of the Alto Paranaiba Igneous Province, Brazil.Chemical Geology, Vol. 353, pp. 65-82.MantleUHP
DS1860-0795
1893
Brough, B.H.Brough, B.H.The Mining Industries of South Africa, As Shown at the Kimberley Exhibition.Journal of the Society of Arts, Vol. 41, PP. 166-177. ALSO: Vol. 52, 1904 PP. 113-122.Africa, South AfricaHistory
DS1860-0407
1883
Brougham, P.Brougham, P.Peel and Uralla District- Bingara Division #1New South Wales Geological Survey Report For 1882, P. 88.Australia, New South WalesDiamond Occurrence
DS1860-0429
1884
Brougham, P.Brougham, P.Peel and Uralla District- Bingara Division #2New South Wales Geological Survey Report For 1883, P. 90.Australia, New South WalesDiamond Occurrence
DS2002-0210
2002
Broughton, D.W.Broughton, D.W., Hitzman, M.W., Stephens, A.J.Exploration history and geology of the Kansanshi Cu Au deposit, ZambiaSociety of Economic Geologists Special Publication, No.9,pp.141-53.ZambiaCopper, gold, copperbelt, Deposit - Kansanshi
DS1950-0017
1950
Broughton, J.G.Broughton, J.G.Observations of the Intrusion of Rock Salt by PeridotiteEos, Vol. 31, No. 2, PP. 229-233.United States, Appalachia, New YorkBlank
DS1975-0964
1979
Broughton, P.L.Broughton, P.L.Economic Geology of Australian Gemstone DepositsMinerals Sci. Eng., Vol. 11, No. 1, PP. 3-21.AustraliaKimberlite, Diamond
DS1980-0076
1980
Broughton, P.L.Broughton, P.L.The Gemmiferous Gravels of the Fraser and Reddistone Creeks, Inverell and Glen Innes District.Journal of Gemology, Vol. 17, No. 2, PP. 95-118.Australia, QueenslandDiamond
DS202203-0346
2021
Brouillet, F.France, L., Brouillet, F., Lang, S.Early carbonatite magmatism at Oldoinyo Lengai volcano ( Tanzania): carbonatite-silicate melt immiscibility in Lengai 1 melt inclusions.Comptes Rendus Geoscience, Vol. 353, no S2, pp. 273-288. pdfAfrica, Tanzaniadeposit - Oldoinyo Lengai

Abstract: Carbonatites are unusual C-rich alkaline magmas that have been reported throughout the geological record. Nevertheless, there is only one currently active carbonatite system on Earth: Oldoinyo Lengai stratovolcano in northern Tanzania (God’s mountain in Maasai culture). Present-day Lengai carbonatites are natrocarbonatites, peculiar Na-rich carbonatites that, under atmospheric conditions, alter and leach to compositions similar to the more common Ca-carbonatites within weeks, preventing any long-term geological record of such Na-rich magmas. It follows that the oldest report of natrocarbonatites at Oldoinyo Lengai dates to the 19th century. Here, by using samples from the Lengai I cone (11 ka), we show that immiscible silicate-carbonatite melts were already present at reservoir conditions at that time. Measurements of three-phase (carbonatite silicate gas) melt inclusions from Lengai I highlight that their chemical compositions were similar to those of immiscible melts recently present in the reservoir. Alkaline carbonatites in melt inclusions from both Lengai I and historical explosive eruptions are enriched in Ca relative to those historically effused at the surface and likely record higher equilibrium temperatures (1100 °C). We also report chemical maps that qualitatively document elemental partitioning between immiscible silicate-carbonatite melts. We show that at the melt inclusions’ entrapment conditions Si, Fe, K, Na, and Cl are compatible with the silicate phase when C, Ca, P, Sr, Ba, and F are compatible with the carbonate phase.
DS1998-1058
1998
Brouillette, P.Nadeau, L., Brouillette, P.Le graben du Saguenay: expression topographique failles et patron regional de fractures.Geological Association of Canada (GAC), Annual Meeting, Vol. 23, p. a133 abstract.QuebecTectonics, structure
DS2003-0091
2003
Brouillette, P.Bedard, J.H., Brouillette, P., Madorc, L., Berclaz, A.Archean cratonization and deformation in the northern Superior Province, Canada: anPrecambrian Research, Vol. 127, 1-2, Nov. pp. 61-87.Northwest Territories, QuebecTectonics
DS200412-0121
2003
Brouillette, P.Bedard, J.H., Brouillette, P., Madorc, L., Berclaz, A.Archean cratonization and deformation in the northern Superior Province, Canada: an evaluation of plate tectonic versus verticalPrecambrian Research, Vol. 127, 1-2, Nov. pp. 61-87.Canada, Northwest Territories, QuebecTectonics
DS1920-0277
1926
Brounlie, W.N.Brounlie, W.N.The Valley of DiamondStone And Webster Journal, Vol. 39, AUGUST, PP. 188-196.South AfricaKimberley, History
DS1920-0060
1921
Brouwer, H.A.Brouwer, H.A.De Alkali gesteenten Van de Serra Do Gericino Ten Noordwesten Van Rio de Janeiro En de Overeen komst der Eruptiefgesteenten Van Brazilie En Suid-afrika.Amsterdam: Akad. Verhand., Vol. 29, PP. 1005-1020.South Africa, BrazilTectonics, Continental Structure
DS1987-0004
1987
Brouxel, M.Albarede, F., Brouxel, M.The Sm/neodymium secular evolution of the continental crust and the depletedmantleEarth and Planetary Science Letters, Vol. 82, No. 1/2, March pp. 25-35GlobalMantle, Genesis
DS201412-0077
2014
Brovarone, A.V.Brovarone, A.V., Beyssac, O.Lawsonite metasomatism: a new route for water to the deep earth.Earth and Planetary Science Letters, Vol. 393, pp. 275-284.MantleMetasomatism
DS202002-0206
2020
Brovarone, A.V.McCammon, C., Bureau, H., Cleaves II, H.J., Cottrell, E., Dorfman, S.M., Kellogg, L.H., Li, J., Mikhail, S., Moussallam, Y., Sanloup, C., Thomson, A.R., Brovarone, A.V.Deep Earth carbon reactions through time and space. ( mentions diamond)American Mineralogist, Vol. 105, pp. 22-27.Mantlesubduction

Abstract: Reactions involving carbon in the deep Earth have limited manifestations on Earth's surface, yet they have played a critical role in the evolution of our planet. The metal-silicate partitioning reaction promoted carbon capture during Earth's accretion and may have sequestered substantial carbon in Earth's core. The freezing reaction involving iron-carbon liquid could have contributed to the growth of Earth's inner core and the geodynamo. The redox melting/freezing reaction largely controls the movement of carbon in the modern mantle, and reactions between carbonates and silicates in the deep mantle also promote carbon mobility. The 10-year activity of the Deep Carbon Observatory has made important contributions to our knowledge of how these reactions are involved in the cycling of carbon throughout our planet, both past and present, and has helped to identify gaps in our understanding that motivate and give direction to future studies.
DS202009-1614
2020
Brovarone, A.V.Brovarone, A.V., Butch, C.J., Ciappa, A., Cleaves, H.J., Elmaleh, A., Faccenda, M., Feineman, M., Hermann, J., Nestola, F., Cordone, A., Giovannelli., D.Let there be water: how hydration/dehydration reactions accompany key Earth and life processes.American Mineralogist, Vol. 105, pp. 1152-1160. pdfMantlecarbon

Abstract: Water plays a key role in shaping our planet and making life possible. Given the abundance of water on Earth's surface and in its interior, chemical reactions involving water, namely hydration and dehydration reactions, feature prominently in nature and are critical to the complex set of geochemical and biochemical reactions that make our planet unique. This paper highlights some fundamental aspects of hydration and dehydration reactions in the solid Earth, biology, and man-made materials, as well as their connections to carbon cycling on our planet.
DS1960-1211
1969
Brovkin, A.A.Shchelkova, S.G., Brovkin, A.A.Titanolivine from Siberian KimberlitesZap. Vses. Miner. Obshch., PT. 98, PP. 246-247.RussiaBlank
DS201412-0956
2014
Brovko, O.Vorster, A., Letts, S., Brovko, O.New advances in kimberlite exploration geophysics.PDAC 2014, March 3, 1p. AbstractTechnologyGeophysics
DS1995-0256
1995
Browder, J.O.Campbell, J.B., Browder, J.O.Field dat a collection for remote sensing analysis: SPOT dat a, Rondonia, Brasil.International Journal of Remote Sensing, Vol. 16, No. 2, Jan. 20, pp. 333-350.BrazilRemote sensing, Not specific to diamonds
DS1993-0451
1993
Brower, J.C.Forster, A., Merriam, D.F., Brower, J.C.Relationship of geological and geothermal field properties: midcontinentarea, USA, an exampleMathematical Geology, Vol. 25, No. 7, pp. 937-947Midcontinent, KansasGeothermal
DS1996-1052
1996
Browm\n, W.L.Ohnenstetter, D., Browm\n, W.L.Compositional variation and primary water contents of differentiated interstitial and included glasses in boninites.Contributions to Mineralogy and Petrology, Vol. 123, pp. 117-137.New CaledoniaBoninites, Glasses
DS201212-0090
2012
Browmik, S.K.Browmik, S.K., Wilde, S.A., Bhandari, A., Pal, T., Pant, N.C.Growth of the greater Indian landmass and its assembly in Rodinia:geochronological evidence from the Central Indian Tectonic Zone.Gondwana Research, Vol. 22, 1, pp. 54-72.IndiaGeochronology, tectonics, cratons
DS1991-0384
1991
BrownDobbs, P.N., Duncan, D.J., Hu, S., Shee, S.R., Colgan, E.A., BrownThe geology of the Mengyin kimberlites, Shandong, ChinaProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 76-78ChinaDiamond exploration, Mineral sampling
DS1994-0434
1994
BrownDobbs, P.N., Duncan, D.J., Hu, S., Shee, S.R., Colgan, E.A., BrownThe geology of the Mengyin kimberlites, Shandong ChinaProceedings of Fifth International Kimberlite Conference, Vol. 1, pp. 40-61.ChinaKimberlite, Deposit -Mengyin
DS1996-0067
1996
BrownBaird, D.J., Nelson, K.D., Knapp, J.H., Walters, BrownCrustal structure and evolution of the Trans-Hudson Orogen: results from seismic reflection profiling.Tectonics, Vol. 15, No. 2, April pp. 416-426.Montana, North Dakota, Saskatchewan, Manitoba, AlbertaCraton, Wyoming, Hearne, Lithoprobe
DS200612-1342
2006
BrownSparks, R.S.J., Baker, Brooker, Brown, Field, Fontana, Gernon, Kavanagh, Shumacher, Stripp, Walter, Walters, White, WindsorDynamical constraints on kimberlite volcanism,Emplacement Workshop held September, 5p. abstractGlobalMagmatism, water, stages
DS201112-0117
2011
BrownBrownThe Holocene eruptions of the Igwisi Hills volcanoes, Tanzania.IUGG Held July 6, AbstractAfrica, TanzaniaVolcanology
DS1991-0181
1991
Brown, A.Brown, A.Diamonds are technology's best friendAerosp. AM., Vol. 29, No. 2, February pp. 26-30GlobalDiamonds, Technological uses
DS1993-0771
1993
Brown, A.Kamineni, D.C., Kerrich, R., Brown, A.Effects of differential reactivity of minerals on the development of brittle to semi-brittle structures in granitic rocks: textural and oxygen isotope evidenceChemical Geology, Vol. 105, pp. 215-232OntarioGeochronology, Tectonic, structure
DS1996-0167
1996
Brown, A.K.Branson, J., Brown, A.K., Gregory, K.J.Global continental changes: the context of paleohydrologyGeological Society of London, No. 115, 280p. approx. $98.00 United StatesGlobalPaleohydrology, Book -ad
DS1992-0173
1992
Brown, A.R.Brown, A.R.Seismic interpretation today and tomorrowGeophysics: the leading edge of exploration, Vol. 11, No. 11, November pp. 10-15GlobalGeophysics -seismics, Overview
DS2003-1047
2003
Brown, B.Paulen, R.C., Pawlowicz, J.G., Fenton, M.M., Weiss, J.A., Brown, B.Stratigraphy and glacial dispersion studies in the Buffalo Head Hills kimberlite fieldGeological Association of Canada Annual Meeting, Abstract onlyAlbertaGeomorphology
DS200412-1506
2003
Brown, B.Paulen, R.C., Pawlowicz, J.G., Fenton, M.M., Weiss, J.A., Brown, B.Stratigraphy and glacial dispersion studies in the Buffalo Head Hills kimberlite field.Geological Association of Canada Annual Meeting, Abstract onlyCanada, AlbertaGeomorphology
DS1982-0451
1982
Brown, B.A.Mudrey, M.G.JR., Brown, B.A.New Bedrock Geology Map of WisconsinGeological Society of America (GSA), Vol. 14, No. 7, P. 572, (abstract.).WisconsinMid-continent
DS1983-0266
1983
Brown, B.A.Greenberg, J.K., Brown, B.A.Proterozoic Cratonization South of the Superior Province Inwisconsin.Geological Society of America (GSA), Vol. 15, No. 6, P. 586. (abstract.).Wisconsin, United States, Great LakesMid Continent
DS1984-0310
1984
Brown, B.A.Greenberg, J.K., Brown, B.A.Cratonic Sedimentation During the Proterozoic; an Orogenic Connection in wisconsin and the Upper Midwest.Journal of GEOLOGY, Vol. 92, No. 2, MARCH PP. 159-172.WisconsinMid-continent
DS200412-0601
2004
Brown, B.J.Gaina, C., Muller, R.D., Brown, B.J., Ishihara, T.Microcontinent formation around Australia.Hillis, R.R., Muller, R.D. Evolution and dynamics of the Australian Plate, Geological Society America Memoir, No. 372, pp. 405-416.AustraliaTectonics
DS1994-0214
1994
Brown, C.Brown, C.Tectonic interpretation of regional conductivity anomaliesSurveys in Geophysics, Vol. 15, No. 2, March pp. 123-158GlobalGeophysics, Tectonics
DS2000-0112
2000
Brown, C.D.Brown, C.D., Phillips, R.J.Crust mantle decoupling by flexure of continental lithosphereJournal of Geophysical Research, Vol. 105, No. 6, June 10, pp. 13221-MantleGeophysics - seismics, Decoupling
DS1998-0169
1998
Brown, C.E.Brown, C.E.Applied multivariate statistics in geohydrology and related sciencesSpringer, 348p. approx. $ 80.00GlobalBook - ad, Geohydrology
DS1992-0174
1992
Brown, D.Brown, D., Rivers, T., Calon, T.A structural analysis of a metamorphic fold and thrust belt, northeast Gagnon terrane, Grenville Province.Can, Journal of Earth Sciences, Vol. 29, pp. 1915-27.Quebec, Labrador, UngavaKnob Lake area, Tectonics - structure
DS1997-0134
1997
Brown, D.Brown, D., Alvarez-Marron, Perez-Estaun, A., GorozhaninaGeometric and kinematic evolution of the foreland thrust and fold belt In the southern UralsTectonics, Vol. 16, No. 3, June, pp. 551-562GlobalTectonics
DS1999-0096
1999
Brown, D.Brown, D., Spadea, P.Processes of forearc and accretionary complex formation during arc continent collision in the southern Ural MtnGeology, Vol. 27, No. 7, July pp. 649-52.Russia, UralsCrust - tectonics, collision
DS2000-0016
2000
Brown, D.Alvarez-Marron, J., Brown, D., Gorozhanina, Y.Accretionary complex structure and kinematics during Paleozoic arc continent collision in the southern UralsTectonophysics, Vol. 235, No. 1-2, Oct. 15, pp. 175-Russia, UralsTectonics
DS2000-0043
2000
Brown, D.Ayala, C., Kimbell, G.S., Brown, D., Ayarza, P.Magnetic evidence for the geometry and evolution of the eastern margin of East European Craton southern UralsTectonophysics, Vol. 320, No.1, Apr.30, pp. 31-44.Russia, UralsTectonics, Craton - East European
DS2000-0045
2000
Brown, D.Ayarza, P., Brown, D., Juhlin, C.Contrasting tectonic history of arc-continent suture in southern and middle Urals: evolution of orogen.Journal of Geological Society of London, Vol. 157, No. 5, Sept.pp.1065-76.Russia, UralsTectonics, Orogeny
DS2000-0113
2000
Brown, D.Brown, D., Carbonell, R., Alvarez-Marron, TryggvasonCrustal and upper mantle structure reveal arc continent collision processes in the southern Uralides.Igc 30th. Brasil, Aug. abstract only 1p.Europe, UralsCraton - East European, Magnitogorsk arc
DS2000-0114
2000
Brown, D.Brown, D., Hetzel, R., Scarrow, J.H.Tracking arch ... continent collision subduction zone processes from high pressure rocks in southern UralsJournal of Geological Society of London, Vol. 157, No. 5, Sept.pp. 901-4.Russia, UralsMetamorphism - ultra high pressure (UHP)
DS2001-0135
2001
Brown, D.Brown, D., Alvarez-Marron, J., Perez-Estaun, PuchkovStructure and evolution of the Magnitogorsk forearc basin: identifying upper crustal processes during arcTectonics, Vol. 20, No. 3, June pp. 364-75.Russia, UralsTectonics, arc terranes, subduction zone
DS2002-0211
2002
Brown, D.Brown, D., Juhlin, C., Puchkov, V.Mountain building in the Uralides ... Pangea to the presentAmerican Geophysical Union, Geophysical Monograph, No. 132, 300p.Russia, Europe, UralsBook - Tectonics, arc collision, crustal, orogenesis, Geochronology
DS2003-0171
2003
Brown, D.Brown, D., Carbonell, R., Kukkonen, I., Ayala, C., Golovanova, I.Composition of the Uralide crust from seismic velocity ( Vp Vs) heat flow , gravity andEarth and Planetary Science Letters, Vol. 210, 1-2, pp. 333-49.Russia, UralsGeophysics
DS200412-0222
2003
Brown, D.Brown, D., Carbonell, R., Kukkonen, I., Ayala, C., Golovanova, I.Composition of the Uralide crust from seismic velocity ( Vp Vs) heat flow , gravity and magnetic data.Earth and Planetary Science Letters, Vol. 210, 1-2, pp. 333-49.Russia, UralsGeophysics
DS200412-0223
2002
Brown, D.Brown, D., Juhlin, C., Puchkov, V.Mountain building in the Uralides ... Pangea to the present.American Geophysical Union, Geophysical Monograph, No. 132, 300p.Russia, Europe, UralsBook - Tectonics, arc collision, crustal, orogenesis Geochronology
DS200612-0176
2006
Brown, D.Brown, D., Juhlin, C.A possible lower crustal flow channel in the Middle Urals based on reflection seismic data.Terra Nova, Vol. 18, 1, Feb. pp. 1-8.Russia, UralsGeophysics - seismics
DS200612-0177
2006
Brown, D.Brown, D., Juhlin, C., Tryggvason, A., Friberg, M., Rybalka, A., Puchkov, V.Structural architecture of the southern and middle Urals foreland from reflection seismicsTectonics, Vol. 25, 1, Jan. TC1002RussiaTectonics
DS200712-0115
2006
Brown, D.Brown, D., Puchkov, V., Alvarez Marron, J., Bea, F., Perez Estaun, A.Tectonic processes in the southern and middle Urals: an overview.Geological Society of London Memoir, No. 32, pp. 407-420.Russia, Europe, UralsTectonics
DS200712-0116
2006
Brown, D.Brown, D., Spadea, P., Puchkov, V., Alvarez-Marron, J., Herrington, R., Willner, A.P., Hetzel, R., Gorozhanina, Y., Juhlin, C.Arc continent collision in the southern Urals.Earth Science Reviews, in press availableRussia, UralsBaltica tectonics, UHP, geochemistry
DS201112-0118
2011
Brown, D.Brown, D., Ryan, P.D.Arc-Continent collision.Springer Frontiers in Earth Sciences, 988p. $ 279.TechnologyBook - note
DS201112-0980
2011
Brown, D.A.Smyth, J.R., Brown, D.A.Hydrous phases in the lower mantle.Goldschmidt Conference 2011, abstract p.1901.MantleSubduction
DS202010-1830
2020
Brown, D.A.Brown, D.A., Tamblyn, R., Hand, M., Morrissey, L.J.Thermobarometric constraints on burial and exhumation of 2 billion year old eclogites and their metapelitic hosts.Precambrian Research, Vol. 347, 105833, 33p. PdfAfrica, Tanzaniaeclogites

Abstract: One of the first appearances of eclogite-facies mineral assemblages in the geological record occurs in the c. 2000 Ma Palaeoproterozoic Usagaran Belt in central Tanzania, where the extended margin of the Tanzanian Craton is interpreted to have been subducted. Mafic rocks are interpreted to have contained the mineral assemblage garnet + omphacite + rutile + quartz ± amphibole. This high-pressure assemblage has been overprinted by a secondary mineral assemblage containing clinopyroxene + plagioclase + hornblende + ilmenite ± orthopyroxene. Mineral equilibria forward modelling indicates that the eclogite-facies assemblages reached minimum peak pressure-temperature (P-T) conditions of ~17 kbar and ~700 °C. Inclusions in garnet document a prograde P-T history consistent with burial through upper amphibolite-facies conditions and possible partial melting. Petrological and compositional evidence from garnet suggests that following peak metamorphism, the eclogite-facies rocks were heated while stalled at approximate peak pressures. Temperature estimates derived from Zr concentrations in interpreted texturally retrograde rutile support a near-isothermal post-peak P-T evolution for the eclogite-facies rocks - an evolution that terminates at retrograde P-T conditions of approximately 7.6-8.2 kbar and 680-790 °C. The relict eclogite domains form part of a larger assemblage with enclosing migmatitic metapelitic lithologies (the Isimani Suite). The metapelitic gneisses contain garnet + kyanite + biotite + staurolite + hornblende + plagioclase + muscovite + rutile + quartz and preserve minimal evidence of a high-pressure history, conceivably due to post-peak mineralogical recrystallisation. P-T modelling, inclusion assemblages and compositional zonation patterns in porphyroblastic garnet suggests the metapelitic gneisses — similarly to the relict eclogites — experienced burial to minimum peak pressures of approximately 16.5-17 kbar. Compositional zoning patterns in eclogitic garnet suggest the Isimani system was buried, reached peak metamorphic conditions, and was subsequently exhumed within a timeframe of up to 20 Myr. A tectonic regime involving crustal thickening and subduction, followed by extensional exhumation of the entire Isimani Suite is our preferred model for the development of the c. 2000 Ma Usagaran Belt.
DS1960-0791
1967
Brown, D.D.Bennett, G., Brown, D.D., George, P.T., Leahy, E.J.Operation KapuskasingOntario Department of Mines M.P., No. 10, 72P.Canada, Ontario, James Bay LowlandsTectonics, Rift Structure, Geomorphology
DS1960-0801
1967
Brown, D.D.Brown, D.D., Bennett, G.S., George, P.T.The Source of Alluvial Kimberlite Indicator Minerals in The james Bay Lowland.Ontario Department of Mines miscellaneous Publishing, No. 7, 35P.Canada, OntarioHistory, Prospecting, Geochemistry
DS1993-0170
1993
Brown, D.S.Brown, D.S.Minerals and the environment in the 21st. century #1Nonrenewable Resources, Vol. 2, No. 3, Fall pp. 181-186United StatesEconomics -minerals, Environment
DS1994-0215
1994
Brown, D.S.Brown, D.S.Minerals and the environment in the 21st. century #2American Institute of Mining, Metallurgical, and Petroleum Engineers, No. 94-58, 3pUnited StatesMining legislation, Environmental
DS1975-0965
1979
Brown, E.H.Brown, E.H., Bradshaw, J.Y.Phase Relations of Pyroxene and Amphibole in Greenstone, Blueschist and Eclogite of the Franciscan Complex, California.Contributions to Mineralogy and Petrology, Vol. 71, No. 1, PP. 67-83.GlobalEclogite, Kimberlite
DS200512-0620
2005
Brown, E.L.Lesher, C.E., Brown, E.L., Heister, L.E.Paleogene North Atlantic Igneous Province and the Iapetus connection.Chapman Conference held in Scotland August 28-Sept. 1 2005, 1p. abstractMantle, Europe, Iceland, GreenlandMantle plume
DS201612-2281
2016
Brown, E.L.Brown, E.L., Lesher, C.E.REEBOX PRO: a forward model simulating melting of thermally and lithologically variable upwelling mantle.Geochemistry, Geophysics, Geosystems: G3, Vol. 17, 10, pp. 3929-3968.MantleMelting
DS1994-0216
1994
Brown, E.T.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
DS1982-0454
1982
Brown, F.H.Nash, W.P., Brown, F.H.Alkaline Lavas and Ultramafic Xenoliths from Marsabit, Eastafrica.Geological Society of America (GSA), Vol. 14, No. 7, P. 574, (abstract.).East Africa, KenyaKimberlite, Lherzolite, Wehrlite
DS1975-0966
1979
Brown, G.Brown, G.Diamond- True or False?Australian Gemologist., Vol. 13, No. 11, PP. 341-351; PP. 354-358.AustraliaMorphology, Diamonds
DS1975-0967
1979
Brown, G.Brown, G.Diamonds- True or False?The Australian Gemologist., Vol. 13, No. 11, PP. 341-351.GlobalGemology, Gem Identification, Classification
DS1984-0176
1984
Brown, G.Brown, G.The Diamondiferous Kimberlite PipesWahroongai News, Vol. 18, No. 7, PP. 12-14.AustraliaGenesis
DS1989-0182
1989
Brown, G.Brown, G.The Snow diamond lightThe Australian Gemologist, Vol. 17, No. 2, May pp. 63-64AustraliaEquipment, Diamond morphology
DS1989-0183
1989
Brown, G.Brown, G., Bracewell, H., Snow, J.Gems of the Mud Tank carbonatiteThe Australian Gemologist, Vol. 17, No. 2, May pp. 52-59AustraliaCarbonatite, Mineralogy
DS1991-0182
1991
Brown, G.Brown, G., Chapman, J.Argyle champagne and cognac diamondsThe Australian Gemologist, Vol. 17, No. 9, Feb. pp. 350-351AustraliaMineralogy, Argyle
DS1994-1037
1994
Brown, G.Linton, T., Beattie, R., Brown, G.Presidium diamond factAustralian Gemologist, Vol. 18, No. 9, February pp. 279-281.GlobalHistory
DS1995-0576
1995
Brown, G.E.Galoisy, L., Calas, G., Brown, G.E.Intracrystalline distribution of nickel in San Carlos olivine: an EXAFS studyAmerican Mineralogist, Vol. 80, No. 9-10, Sept, Oct pp. 1089-1092.ArizonaPeridotite
DS2001-0136
2001
Brown, G.E.Brown, G.E., Parks, G.A.Sorption of trace elements on mineral surfaces: modern perspectives from spectroscopic studies...International Geology Review, Vol.43,11,Nov.pp.963-1041.GlobalBook - table of contents - full issue, Spectroscopy - marine environment
DS201711-2502
2017
Brown, G.E.Brown, G.E., Hochella, M.F., Calas, G.Improving mitigation of the long term legacy of mining activities: nano and molecular level concepts and methods.Elements, Vol. 13, pp. 325-330.Globalresources

Abstract: Mining activities over several millennia have resulted in a legacy of environmental contamination that must be mitigated to minimize ecosystem damage and human health impacts. Designing effective remediation strategies for mining and processing wastes requires knowledge of nano- and molecular-scale speciation of contaminants. Here, we discuss how modern nano- and molecular-level concepts and methods can be used to improve risk assessment and future management of contaminants that result from mining activities, and we illustrate this approach using relevant case studies.
DS1900-0650
1908
Brown, H.Y.L.Brown, H.Y.L.Diamonds. Records of the Mines of South AustraliaSouth Australia Geological Survey, 4TH. EDITION, P. 358.Australia, South AustraliaDiamond, Echunga
DS1920-0432
1929
Brown, I.A.Brown, I.A.A Garnet Bearing Dyke Near Moruya, New South WalesNew South Wales Proceedings Linn. Soc., Vol. 54, PP. 176-184.Australia, New South WalesKimberlite
DS1991-0183
1991
Brown, I.J.Brown, I.J.Environmental assessment - a new experienceTransactions of the Institute of Mining and Metallurgy (IMM), Vol. 100, Jan-April pp. A47-A50EuropeLegal, Environmental assessment
DS1993-0171
1993
Brown, J.M.Brown, J.M.Mantle melting at high pressureScience, Vol. 262, No. 5133, October 22, p. 529MantleMelting
DS1993-0172
1993
Brown, J.M.Brown, J.M.Mantle melting at high pressureScience, Vol. 262, No. 5133, October 22, pp. 529-530.MantleMelting
DS1993-1808
1993
Brown, J.M.Zaug, J.M., Abramson, E.H., Brown, J.M., Slutsky, L.J.Second velocites in olivine at earth mantle pressuresScience, Vol. 260, No. 5113, June 4, pp. 1487-1488.MantleOlivine
DS1998-1414
1998
Brown, J.M.Stixrude, L., Brown, J.M.The Earth's coreReviews in Mineralogy, Vol. 37, pp. 261-283.MantleGeophysics, Geodynamics - boundary
DS2000-0013
2000
Brown, J.P.Alsop, G.I., Brown, J.P., Gibling, M.R.The geometry of drag zones adjacent to salt diapirsJournal of Geological Society of London, Vol. 157, No. 5, Sept.pp.1019-30.GlobalStructure - diapirs ( salt) not specific to diamond
DS1999-0191
1999
Brown, J.R.Edwards, D.J., Brown, J.R.Understanding the influence of Precambrian crystalline basement on Upper Devonian carbonates central AlbertaLithoprobe, No. 47, pp. 412-38.AlbertaGeophysics - magnetics not specific to diamonds
DS1950-0172
1954
Brown, J.S.Brown, J.S., Emery, J.A., Myer, P.A.Explosion Pipe in Test Well on Hicks Dome Hardin County, Illinois.Economic Geology, Vol. 49, PP. 891-902.GlobalGeology
DS1950-0292
1956
Brown, J.S.Ohle, E.L., Brown, J.S.Geologic Problems in Southeast Missouri Lead DistrictGeological Society of America (GSA) Bulletin., Vol. 65, PP. 201-221.GlobalKimberlite, Central States
DS1995-0217
1995
Brown, J.W.Brown, J.W.Kimberlite conference (brief 1p. editorial)Material World, Vol. 3, No. 11, Nov. p. 553. #TD898RussiaNews item
DS1995-0218
1995
Brown, J.W.Brown, J.W.Geological and economic appraisal of Tychana river diamond occurrences, Siberia.Ph.d. Thesis, Cambourne School of Mines, Russia, SiberiaEconomics, Deposit -Tychana area
DS1996-0181
1996
Brown, J.W.Brown, J.W.Diamondiferous kimberlites of SaskatchewanPh.D. Thesis, Cambourne School Mines**IN PREP REF ONLY, SaskatchewanKimberlites, Overview
DS1998-0170
1998
Brown, J.W.Brown, J.W., Butcher, A.R.Textural and petrological variation within the Crater facies kimberlite bodies of the Fort a la Corne Province7th International Kimberlite Conference Abstract, pp. 103-4.SaskatchewanPetrography, Classification
DS1988-0039
1988
Brown, K.M.Barber, T., Brown, K.M.Shale diapirism, an adequate mechanism for the formation of melanges inaccretionary complexesGeology Today, May-June pp. 89-94GlobalMud diapirs
DS1988-0089
1988
Brown, K.M.Brown, K.M., Westbrook, G.K.Mud diapirism and subcretion in the Barbados Ridge accretionary complex:the role of fluids in active margin developmentTectonics, Vol. 7, pp. 613-640GlobalMud diapirs
DS1990-0246
1990
Brown, K.M.Brown, K.M.The nature and hydrogeologic significance of mud diapirs and diatremes for accretionary systemsJournal of Geophy. Res, Vol. 95 pp. 8969-8982GlobalMud diapirs
DS1994-0217
1994
Brown, K.W.Brown, K.W.New horizons in soil remediationGeotimes, Vol. 39, No. 9, Sept. pp. 15-17United StatesEnvironment, Soil remediation -brief overview
DS1981-0103
1981
Brown, L.Brown, L., Serpa, L., et al.Intra Crustal Complexities of the U.s. Midcontinent Preliminary Results from Cocorp Surveys in Northeast Kansas.Eos, Vol. 62, No. 45, P. 955. (abstract.).KansasMid Continent
DS1982-0559
1982
Brown, L.Serpa, L., Brown, L., Setzer, T., Farmer, H., Oliver, J., Kaufman.Rift Structure from Cocorp Surveys in the MidcontinentEarthquake Notes, Vol. 54, No. 1, PP. 45-46.GlobalMid-continent
DS1983-0154
1983
Brown, L.Brown, L., Ando, C., Klemperer, J., Oliver, J.A., Kaufman, S. C.Adirondack Appalachian Crustal Structure: the Cocorp Northeast Traverse.Geological Society of America (GSA) Bulletin., Vol. 94, No. 10, OCTOBER PP. 1173-1184.GlobalMid Continent
DS1983-0258
1983
Brown, L.Good, R., Brown, L., Oliver, J., Kaufman, S.Cocorp Deep Seismic Reflection Traverse Across the southern Oklahoma Aulocogen.American Association of Petroleum Geologists (AAPG) STUDIES IN GEOLOGY, No. 15, PP. 3.2.2-33- 3.2.2.-37.OklahomaMid-continent
DS1983-0358
1983
Brown, L.Klemperer, S.L., Brown, L., Czuchra, B., Ando, C.Cocorp Seismic Reflection Profiling in the Grenville Age Adirondack Mountains, New York State: Results and Geologic Implications.Geological Society of America (GSA), Vol. 15, No. 6, P. 615. (abstract.).GlobalMid Continent
DS1983-0492
1983
Brown, L.Oliver, J., Cook, F., Brown, L.Cocorp and the Continental CrustJournal of GEOPHYSICAL RESEARCH, Vol. 88, No. B4, APRIL 10, PP. 3329-3347.GlobalMid-continent
DS1984-0650
1984
Brown, L.Serpa, L., Setzer, T., Farmer, H., Brown, L., Oliver, J., Kaufman.Structure of the Southern Keweenawan Rift from Cocorp SurveyTectonics, Vol. 3, No. 3, JUNE PP. 367-384.United States, KansasMid-continent
DS1984-0651
1984
Brown, L.Serpa, L., Setzer, T., Farmer, H., Peddy, C., Brown, L., Oliver, J.Cocorp Profiling Across the Midcontinent Gravity HighGeological Society of America (GSA), Vol. 16, No. 2, FEBRUARY P. 113. (abstract.).GlobalMid-continent
DS1985-0487
1985
Brown, L.Nelson, K.D., Arnow, J.A., Mcbride, J.H., Wille, D.M., Brown, L.New Cocorp Profiling in the Southeastern U.s.: Major Features and Regional Implications.Geological Society of America (GSA), Vol. 17, No. 7, P. 675. (abstract.).United States, Appalachia, GeorgiaMidcontinent
DS1986-0598
1986
Brown, L.Nelson, K.D., Allmendinger, R., Potter, C., Hauser, E., Brown, L.Reflection character of the continental MOHO and its tectonicsignificanceGeological Society of America (GSA) Abstract Volume, Vol. 18, No. 6, p. 704. (abstract.)GlobalTectonics
DS1988-0406
1988
Brown, L.Latham, T.S., Best, J., Chaimov, T., Oliver, J., Brown, L.COCORP profiles from the Montana plains: the Archean cratonic crust And a lower crustal anomaly beneath the Williston basinGeology, Vol. 16, No. 12, December pp. 1073-1076MontanaMantle, Geophysics
DS1989-1237
1989
Brown, L.Pratt, T., Culotta, R., Hauser, E., Nelson, D., Brown, L., Kaufman, S.Major Proterozoic basement features of the eastern midcontinent of North america revealed by recent COCORP profilingGeology, Vol. 17, No. 6, June pp. 505-509MidcontinentTectonics, Geophysics
DS1991-0184
1991
Brown, L.Brown, L., Nelson, K.D., et al.Crustal reflection patterns and plate tectonics evidence from Cocorp profiling in the U.S.Geological Society of America Annual Meeting Abstract Volume, Vol. 23, No. 5, San Diego, p. A 315MidcontinentTectonics -plate, Geophysics -seismics
DS1991-1118
1991
Brown, L.Meissner, R., Brown, L.Seismic reflections from the earth's crust- comparative studies of tectonicpatternsGeophysical Journal International, Vol. 105, No. 1, April pp. 1-2GlobalGeophysics -seismics, Tectonics -crust
DS1992-0319
1992
Brown, L.Culotta, R., Latham, T., Sydow, M., Oliver, J., Brown, L., KaufmanDeep structure of the Texas Gulf passive margin and its Ouachita Precambrian basement: results of the COCORP San Marcos Arch surveyAmerican Association of Petroleum Geologists Bulletin, Vol. 76, No. 2, February pp. 270-285GlobalTectonics, Geophysics -seismics COCORP
DS1992-0683
1992
Brown, L.Hauck, M.L., Baird, D., Brown, L., Nelson, K.D., Walters, J.COCORP deep seismic reflection profiling across the Williston Basin and underlying Trans-Hudson Orogen: acquisition and analysisEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p. 321SaskatchewanCOCORP -seismic, Williston Basin
DS1998-0343
1998
Brown, L.Diaconescu, C.C., Knapp, J., Brown, L., Steer, StillerPrecambrian Moho offset and tectonic stability of the East European Platform from URSEIS deep profile....Geology, Vol. 26, No. 3, March pp. 211-214.GlobalGeophysics - seismics, Makorovo fault zone
DS2002-0462
2002
Brown, L.Fisher, N.D., Jordan. T.E., Brown, L.The structural and stratigraphic evolution of the la Rioja basin, ArgentinaJournal of South American Earth Sciences, Vol.15,1,Apr.pp.141-56.Argentina, AndesTectonics
DS200512-0581
2005
Brown, L.Kroner, A., Brown, L.Structure, composition and evolution of the South Indian and Sri Lankan granulite terrains from deep seismic profiling and geophysical investigations.Gondwana Research, Vol. 8, 3, pp. 317-335.India, AsiaGeophysics - seismics
DS200812-0057
2008
Brown, L.Attoh, K., Brown, L.Deep structure of the southeastern margin of the West African craton from seismic reflection data, offshore Ghana.Special Publication - Geological Society of London, No. 297, pp. 499-508.Africa, GhanaTectonics
DS201607-1335
2016
Brown, L.Brown, L.Imaging the crust and large N arrays.IGC 35th., Session The Deep Earth 1 p. abstractMantleGeophysics - seismics
DS1981-0098
1981
Brown, L.D.Brewer, J.A., Good, R., Brown, L.D., Oliver, J.E., Kaufman, S.Cocorp Seismic Reflection Traverse Across the Southern Oklahoma Aulacogen.Geological Society of America (GSA), Vol. 13, No. 7, P. 416. (abstract.).OklahomaMid-continent
DS1982-0119
1982
Brown, L.D.Brewer, J.A., Good, R., Oliver, J.E., Brown, L.D., Kaufman, S.Cocorp Deep Seismic Reflection Profiling of the Southern Oklahoma Aulacogen.Geological Society of America (GSA), Vol. 14, No. 3, P. 106. (abstract.).OklahomaMid-continent, Geophysics
DS1983-0147
1983
Brown, L.D.Brewer, J.A., Good, R., Oliver, J.E., Brown, L.D., Kaufman, S.Cocorp Profiling Across the Southern Oklahoma Aulacogen: Over thrusting of the Wichita Mountains and Compression Within The Anadarko Basin.Geology, Vol. 11, No. 2, PP. 109-114.OklahomaMid-continent, Geophysics
DS1983-0155
1983
Brown, L.D.Brown, L.D., Serpa, L., Setzer, T., Oliver, J., Kaufman, S., Lill.Intracrustal Complexity in the United States Midcontinent; PGeology, Vol. 11, No. 1, PP. 25-30.KansasMid-continent
DS1983-0182
1983
Brown, L.D.Cook, F.A., Brown, L.D., Kaufman, S., Oliver, J.E.The Cocorp Southern Appalachian TraverseAmerican Association of Petroleum Geologists (AAPG) STUDIES IN GEOLOGY, No. 15, PP. 3.2.1-1, 3.2.1-6.AppalachiaMid-continent
DS1983-0183
1983
Brown, L.D.Cook, F.A., Brown, L.D., Kaufman, S., Oliver, J.E.The Cocorp Seismic Reflection Traverse Across the Southern Appalachians.American Association of Petroleum Geologists SPEC. Publishing, 60P.United StatesMid Continent
DS1984-0016
1984
Brown, L.D.Ando, C.J., Czuchra, B.L., Klemperer, S.L., Brown, L.D.Crustal Profile of Mountain Belt: Cocorp Deep Seismic ReflecAmerican Association of Petroleum Geologists, Vol. 68, No. 7, JULY, PP. 819-837.Appalachia, New Hampshire, VermontMid-continent
DS1984-0177
1984
Brown, L.D.Brown, L.D., Zhu, T.F.Keweenawan Rift Structure and Stratigraphy Beneath the Michigan Basin from Cocorp Profiling.Geological Association of Canada (GAC), Vol. 9, P. 49. (abstract.).MichiganMid-continent
DS1984-0303
1984
Brown, L.D.Gibbs, A.K., Payne, B., Setzer, T., Brown, L.D., Oliver, J.E.Seismic Reflection Study of the Precambrian Crust of Central Minnesota.Geological Society of America (GSA) Bulletin., Vol. 95, No. 3, PP. 280-294.GlobalMid-continent
DS1984-0583
1984
Brown, L.D.Petersen, T.A., Brown, L.D., Cook, F.A., Kaufman, S., Oliver, J.Structure of the Riddleville Basin from Cocorp Seismic Data and Implications for Reactivation Tectonics.Journal of GEOLOGY, Vol. 92, PP. 261-271.GlobalMid-continent
DS1985-0732
1985
Brown, L.D.Wille, D.M., Brown, L.D., Nelson, D.K., Arnow, J.A., Mcbride, J.The Surrency Bright Spot: Possible Evidence for Fluid in The Deep Crust.Geological Society of America (GSA), Vol. 17, No. 7, P. 751. (abstract.).United States, Appalachia, GeorgiaMidcontinent, Geotectonics, Suture Zone, Rift
DS1986-0899
1986
Brown, L.D.Zhu Tianfeil, Brown, L.D.Consortium for continental reflection profiling Michigan surveys:reprocessing and resultsJournal of Geophysical Research, Vol. 91, No. B11, October 10, pp. 11, 477-11, 495Midcontinent, MichiganGeophysics
DS1989-0756
1989
Brown, L.D.Keach, R.W., Oliver, J.E., Brown, L.D., Kaufman, S.Cenozoic active margin and shallow Cascades structure: COCORP results from western OregonGeological Society of America (GSA) Bulletin, Vol. 101, No. 6, June pp. 783-394OregonGeophysics -Seismics, Tectonics
DS1991-0185
1991
Brown, L.D.Brown, L.D.A new map of crustal terranes in the United States from COCORP Deep seismic reflection profilingGeophysical Journal International, Vol. 105, No. 1, April pp. 3-14United StatesGeophysics -seismics, Tectonics -crust
DS1991-1913
1991
Brown, L.D.Yoos, T.R., Potter, C.J., Thigpen, J.L., Brown, L.D.The Cordilleran foreland thrust belt in northwestern Montana and northern Idaho from COCORP and industry seismic reflection dataAmerican Association Petrol. Geol, Vol. 75, No. 6, June pp. 1089-1106Montana, IdahoGeophysics -seismics, Tectonics
DS1992-0069
1992
Brown, L.D.Baird, D.J., Nelson, K.D., Walters, J., Hauck, M., Brown, L.D.Deep structure of the Proterozoic Trans-Hudson Orogen beneath the WillistonBasin: results from recent COCORP seismic reflection profilingEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p. 321SaskatchewanCOCORP -seismic, Williston Basin
DS1992-0175
1992
Brown, L.D.Brown, L.D.Structure of Precambrian crust in the U.S. from COCORP deep seismicprofilingGeological Society of America (GSA) Abstracts with programs, 1992 Annual, Vol. 24, No. 7, abstract p. A82MidcontinentCOCORP, Geophysics -seismics
DS1992-0351
1992
Brown, L.D.De Makos, R.M.D., Brown, L.D.Deep seismic profile of the Amazonian craton (northern Brasil) #1Tectonics, Vol. 11, No. 3, June pp. 621-633BrazilGeophysics -seismics, Craton
DS1995-0092
1995
Brown, L.D.Baird, D.J., Knapp, J.H., Steer, D.N., Brown, L.D., NelsonUpper mantle reflectivity beneath the Williston Basin, phase change @and origin of intracratonic basinsGeology, Vol. 23, No. 5, May pp. 431-434.SaskatchewanTrans Hudson Orogeny, Crust
DS1996-1366
1996
Brown, L.D.Steer, D.N., Brown, L.D., Knapp, J.H., Baird, D.J.Comparison of explosive and vibroseis source energy penetration during COCORP deep seismic Williston BasinGeophysics, Vol. 61, No. 1, Jan-Feb. pp. 211-221.Alberta, SaskatchewanGeophysics -seismics, Williston Basin
DS1998-1405
1998
Brown, L.D.Steer, D.N., Knapp, J.H., Brown, L.D.Super deep reflection profiling: exploring the continental mantle lidTectonophysics, Vol. 286, No. 1-4, Mar. 10, pp. 111-22.MantleGeophysics - seismic
DS1998-1406
1998
Brown, L.D.Steer, D.N., Knapp, J.H., Brown, L.D., et al.Deep structure of the continental lithosphere in an unextended orogen: an explosive source seismic ..UralsTectonics, Vol. 17, No. 2, Apr. pp. 143-157.GlobalGeophysics - seismic
DS200912-0077
2009
Brown, L.D.Brown, L.D.New seismic approaches to persistent and new problems in deep crustal geology.GAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyMantleGeodynamics
DS1992-1030
1992
Brown, L.L.McEnroe, S.A., Brown, L.L.Implications for the Mesozoic APW for North America from intrusions and sedimentary rocks in New EnglandEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p. 95GlobalCretaceous intrusions, Paleomagnetics
DS1989-0187
1989
Brown, L.M.Bruley, J., Brown, L.M.Quantitative electron energy loss spectroscopy microanalysis of platelet and voidite defects in natural diamondPhilosph. Mag.Lett., , A., Vol. 59, No. 2, pp. 247-261GlobalDiamond, Natural diamond -voidites
DS1988-0090
1988
Brown, M.Brown, M.Capex to surge again in 1989. ( Capital expenditures)-brief outline re:South Africa and de BeersSouth African Gold, Coal and Base Minerals, October p. 37South AfricaNews item, Capex
DS1991-0791
1991
Brown, M.Jenner, G.A., Dunning, G.R., Malpas, J., Brown, M., Brace, T.Bay of Islands and Little Port complexes, revisited: age, geochemical and isotopic evidence confirm suprasubduction-zone originCanadian Journal of Earth Sciences, Vol. 28, No. 10, October pp. 1635-1652NewfoundlandOphiolites, Geochronology
DS1994-0668
1994
Brown, M.Grocott, J., Brown, M., Dallmeyer, R.D., Taylor, G.K., TreloarMechanisms of continental growth in extensional arcs: an example from the Andean plate boundary zoneGeology, Vol. 2, No. 5, May pp. 391-393Andes, ChileTectonics, Arcs
DS1995-0219
1995
Brown, M.Brown, M., Rushmer, T., Sawyer, E.Introduction to: mechanisms and consequences of melt segregation from crustal protolithsJournal of Geophysical Research, Vol. 100, No. B8, Aug. 10, pp. 15, 551-64MantleCrust, Melt segregation
DS1996-0323
1996
Brown, M.Dallmeyer, R.D., Brown, M., Grocott, J., et al.Mesozoic magmatic and tectonic events within the Andean plate boundaryzone, North Chile: constraints 40Ar/39ArJournal of Geology, Vol. 104, No. 1, pp. 19-40ChileTectonics, Geochronology
DS1998-0171
1998
Brown, M.Brown, M., Solar, G.S.Shear zone systems and melts: feedback relations and self organization in orogenic beltsJournal of Struct. Geol, Vol. 20, No. 2-3, Feb.1, pp. 211-228GlobalTectonics, Orogeny, subduction
DS2001-0137
2001
Brown, M.Brown, M.From microscope to mountain belt: 150 years of petrology - contribution to understanding geodynamicsJournal of Geodynamics, Vol. 32, No. 1-2, pp. 115-164.MantleTectonics
DS2002-0212
2002
Brown, M.Brown, M.Point of sale... why is Canada waiting to make a big splash at the retail counter?Canadian Diamonds, Winter, pp. 22-27.CanadaNews item, Diamond sales
DS2002-0213
2002
Brown, M.Brown, M.A cut above.. from their Yellowknife base, Canada's diamond manufacturers seek global recognition.Canadian Business, September 30, p. 55-57.Northwest TerritoriesNews item, Tiffany
DS2002-0214
2002
Brown, M.Brown, M.The new Tahera. New board, new CEO and Dummett. Jericho project areaCanadian Diamonds, pp. 34, 49.Northwest Territories, NunavutNews item, Tahera Corporation
DS2002-1089
2002
Brown, M.Moraes, R., Brown, M., Fuck, R.A., Camargo, M.A., Lima, T.M.Characterization and P T evolution of melt bearing ultrahigh temperature granulites: anJournal of Petrology, Vol. 43, 9, Sept.pp. 1673-1706.BrazilUHP - mineralogy - not specific to diamonds
DS2002-1246
2002
Brown, M.Percival, J.A., Brown, M., Heaman, L., Hynes, A., Rivers, T., Skulski, T.Tectonic and magmatic processes in crustal growth: a pan lithospheric perspectiveGeoscience Canada, Vol. 29, 7, Sept. pp. 121-5.MantleMafic magmatism, accretionary tectonics, collision
DS2002-1247
2002
Brown, M.Percival, J.A., Brown, M., Heaman, L., Rivers, T., Skulski, T.Tectonic and magmatic processes in crustal growth: a pan-lithoprobe perspectiveGeoscience Canada, Vo. 29, No. 3, September pp. 121-5.Canada, MantleGeophysics - seismics, lithoprobe, rifting, arc, Accretion, collision
DS2003-0172
2003
Brown, M.Brown, M., Baldwin, J., Morales, J., Fuck, R.Modelling ultra hot beauties from Brazil: peak temperature and P-T evolutionGeological Society of America, Annual Meeting Nov. 2-5, Abstracts p.222.BrazilUHP
DS200412-0224
2004
Brown, M.Brown, M.Breaking away from the pack. Analysts share their strategies, John Kaiser comments.Canadian Diamonds, Winter 2004, pp. 29-32.GlobalNews item - exploration
DS200412-0225
2002
Brown, M.Brown, M.Point of sale... why is Canada waiting to make a big splash at the retail counter?Canadian Diamonds, Winter, pp. 22-27.CanadaNews item Diamond sales
DS200412-0226
2004
Brown, M.Brown, M.Melt loss from lower continental crust: observations, mechanisms and implications.Geological Association of Canada Abstract Volume, May 12-14, SS04-01 p. 120.abstractMantleOrogen, melting
DS200412-0227
2003
Brown, M.Brown, M., Baldwin, J., Morales, J., Fuck, R.Modelling ultra hot beauties from Brazil: peak temperature and P-T evolution.Geological Society of America, Annual Meeting Nov. 2-5, Abstracts p.222.South America, BrazilUHP
DS200612-0178
2006
Brown, M.Brown, M.Melt extraction from the lower continental crust of orogens: the field evidence.Evolution and differentiation of Continental Crust, ed. Brown, M., Rushmer, T., Cambridge Univ. Press, Chapter 2, pp. 331-383.MantleMagma transport, melting
DS200612-0179
2006
Brown, M.Brown, M.Melt extraction from lower continental crust of orgens: the field evidence.Brown, M., Rushmer, T., Evolution and differentiation of the continental crust, Cambridge Publ., Chapter 10,MantleOrogeny
DS200612-0180
2006
Brown, M.Brown, M.Is extreme metamorphism the hallmark of plate tectonics?Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.MantleTectonics
DS200612-0181
2006
Brown, M.Brown, M.Do ultrahigh temperature and ultrahigh pressure metamorphic belts record secular change in tectonic regime on Earth?International Mineralogical Association 19th. General Meeting, held Kobe, Japan July 23-28 2006, Abstract p.205.MantleUHP
DS200612-0182
2006
Brown, M.Brown, M., Rushmer, T.Evolution and differentiation of the continental crust. Melting, melt extraction, rheology, transport.cambridge.org/us/earth, 562p. $ 140.00 ISBN 10-0521782376TechnologyBook - geothermometry, mantle composition
DS200712-0117
2006
Brown, M.Brown, M.Diamond in the rough Tahera defied the skeptics when it opened a mine in Nunavut.Canadian Business, Vol. 79, no. 21, pp. 71-76.Canada, NunavutHistory - Jericho
DS200712-0118
2007
Brown, M.Brown, M.Crustal melting and melt extraction, ascent and emplacement in orogens: mechanisms.Journal Geological Society of London, Vol. 164, 4, pp. 709-730.MantleMelting
DS200812-0144
2008
Brown, M.Brown, M.Characteristic thermal regimes of plate tectonics and their metamorphic imprint throughout Earth history: when did the Earth first adopt a plate tectonics mode of behaviour?Geological Society of America Special Paper, 440, pp. 97-128.MantleGeothermometry
DS201012-0718
2010
Brown, M.Sizova, E., Gerya, T., Brown, M., Perchuk, L.L.Subduction styles in the Precambrian: insight from numerical experiments.Lithos, Available in press, formatted 21p.MantleSubduction, tectonics
DS201112-0119
2011
Brown, M.Brown, M., Korhonen, F.J., Siddoway, C.S.Organizing melt flow through the crust.Elements, Vol. 7, 4, August pp. 261-266.MantleDykes, ductile fracturing, migmatites
DS201112-0918
2011
Brown, M.Sawyer, E.W., Cesare, B., Brown, M.When the continental crust melts.Elements, Vol. 7, 4, August pp. 229-234.MantleMelting
DS201212-0660
2012
Brown, M.Sizova,E., Gerya, T., Brown, M.Exhumation mechanisms of melt bearing ultrahigh pressure crustal rocks during collision of spontaneously moving plates.Journal of Metamorphic Geology, Vol. 30, 9, pp. 927-955.MantleUHP
DS201212-0661
2012
Brown, M.Sizoya, E., Gerya, T., Brown, M.Exhumation mechanisms of melt bearing ultrahigh pressure crustal rocks during collision of spontaneously moving plates.Journal of Metamorphic Geology, in press availableRussia, KazakhstanKokchetav Massif, UHP
DS201312-0004
2013
Brown, M.Abu-Alam, T.S., Santosh, M., Brown, M.,Stuwe, K.Gondwana collision.Mineralogy and Petrology, Vol. 107, pp. 631-634.MantleKenoraland
DS201312-0829
2014
Brown, M.Sizova, E., Gerya, T., Brown, M.Contrasting styles of Phanerozoic and Precambrian continental collision.Gondwana Research, Vol. 25, 2, pp. 522-545.MantleGeothermometry
DS201412-0433
2013
Brown, M.Johnson, T.E., Brown, M., Klaus, J.P., VanTongeren, J.A.Delamination and recycling of Archean crust caused by gravitational instabilities.Nature Geoscience, Vol. 7, 1p.MantleArchean - craton
DS201412-0835
2014
Brown, M.Sizova, E., Gerya, T., Brown, M.Contrasting styles of Phanerozoic and Precambrian continental collision.Gondwana Research, Vol. 25, pp. 522-545.MantleTectonics, slab breakoff
DS201704-0630
2017
Brown, M.Johnson, T.E., Brown, M., Gardiner, N.J., Kirkland, C.L., Smithies, R.H.Earth's first stable continents did not form by subduction.Nature, Vol. 543, pp. 239-242.MantleGeodynamics

Abstract: The geodynamic environment in which Earth’s first continents formed and were stabilized remains controversial1. Most exposed continental crust that can be dated back to the Archaean eon (4 billion to 2.5 billion years ago) comprises tonalite-trondhjemite-granodiorite rocks (TTGs) that were formed through partial melting of hydrated low-magnesium basaltic rocks2; notably, these TTGs have ‘arc-like’ signatures of trace elements and thus resemble the continental crust produced in modern subduction settings3. In the East Pilbara Terrane, Western Australia, low-magnesium basalts of the Coucal Formation at the base of the Pilbara Supergroup have trace-element compositions that are consistent with these being source rocks for TTGs. These basalts may be the remnants of a thick (more than 35?kilometres thick), ancient (more than 3.5 billion years old) basaltic crust4, 5 that is predicted to have existed if Archaean mantle temperatures were much hotter than today’s6, 7, 8. Here, using phase equilibria modelling of the Coucal basalts, we confirm their suitability as TTG ‘parents’, and suggest that TTGs were produced by around 20 per cent to 30 per cent melting of the Coucal basalts along high geothermal gradients (of more than 700 degrees Celsius per gigapascal). We also analyse the trace-element composition of the Coucal basalts, and propose that these rocks were themselves derived from an earlier generation of high-magnesium basaltic rocks, suggesting that the arc-like signature in Archaean TTGs was inherited from an ancestral source lineage. This protracted, multistage process for the production and stabilization of the first continents—coupled with the high geothermal gradients—is incompatible with modern-style plate tectonics, and favours instead the formation of TTGs near the base of thick, plateau-like basaltic crust9. Thus subduction was not required to produce TTGs in the early Archaean eon.
DS201712-2735
2017
Brown, M.Wang, L., Wang, S-J., Brown, M., Zhang, J-F., Feng, P., Jin, Z.M.On the survival of intergranular coesite in UHP eclogite.Journal of Metamorphic Geology, in press availableChinaUHP

Abstract: Coesite is typically found as inclusions in rock-forming or accessory minerals in ultrahigh-pressure (UHP) metamorphic rocks. Thus, the survival of intergranular coesite in UHP eclogite at Yangkou Bay (Sulu belt, eastern China) is surprising and implies locally ‘dry’ conditions throughout exhumation. The dominant structures in the eclogites at Yangkou are a strong D2 foliation associated with tight-to-isoclinal F2 folds that are overprinted by close-to-tight F3 folds. The coesite-bearing eclogites occur as rootless intrafolial isoclinal F1 fold noses wrapped by a composite S1-S2 foliation in interlayered phengite-bearing quartz-rich schists. To evaluate controls on the survival of intergranular coesite we determined the number density of intergranular coesite grains per cm2 in thin section in two samples of coesite eclogite (phengite absent) and threee samples of phengite-bearing coesite eclogite (2-3 vol.% phengite), and measured the amount of water in garnet and omphacite in these samples, and also in two samples of phengite-bearing quartz eclogite (6-7 vol.% phengite, coesite absent). As coesite decreases in the mode, the amount of primary structural water stored in the whole rock, based on the nominally anhydrous minerals (NAMs), increases from 107/197 ppm H2O in the coesite eclogite to 157-253 ppm H2O in the phengite-bearing coesite eclogite to 391/444 ppm H2O in the quartz eclogite. In addition, there is molecular water in the NAMs and modal water in phengite. If the primary concentrations reflect differences in water sequestered during the late prograde evolution, the amount of fluid stored in the NAMs at the metamorphic peak was higher outside of the F1 fold noses. During exhumation from UHP conditions, where NAMs became H2O saturated, dehydroxylation would have generated a free fluid phase. Interstitial fluid in a garnet-clinopyroxene matrix at UHP conditions has dihedral angles >60°, so at equilibrium fluid will be trapped in isolated pores. However, outside the F1 fold noses strong D2 deformation likely promoted interconnection of fluid and migration along the developing S2 foliation, enabling conversion of some or all of the intergranular coesite into quartz. By contrast, the eclogite forming the F1 fold noses behaved as independent rigid bodies within the composite S1-S2 foliation of the surrounding phengite-bearing quartz-rich schists. Primary structural water concentrations in the coesite eclogite are so low that H2O saturation of the NAMs is unlikely to have occurred. This inherited drier environment in the F1 fold noses was maintained during exhumation by deformation partitioning and strain localization in the schists, and the fold noses remained immune to grain-scale fluid infiltration from outside allowing coesite to survive. The amount of inherited primary structural water and the effects of strain partitioning are important variables in the survival of coesite during exhumation of deeply subducted continental crust. Evidence of UHP metamorphism may be preserved in similar isolated structural settings in other collisional orogens.
DS201806-1259
2018
Brown, M.Wang, L., Wang, S., Brown, M., Zhang, J., Feng, P., Jin, Z.M.On the survival of intergranular coesite in UHP eclogite.Journal of Metamorphic Geology, Vol. 36, 2, pp. 173-194.MantleUHP

Abstract: Coesite is typically found as inclusions in rock?forming or accessory minerals in ultrahigh?pressure (UHP) metamorphic rocks. Thus, the survival of intergranular coesite in UHP eclogite at Yangkou Bay (Sulu belt, eastern China) is surprising and implies locally “dry” conditions throughout exhumation. The dominant structures in the eclogites at Yangkou are a strong D2 foliation associated with tight?to?isoclinal F2 folds that are overprinted by close?to?tight F3 folds. The coesite?bearing eclogites occur as rootless intrafolial isoclinal F1 fold noses wrapped by a composite S1-S2 foliation in interlayered phengite?bearing quartz?rich schists. To evaluate controls on the survival of intergranular coesite, we determined the number density of intergranular coesite grains per cm2 in thin section in two samples of coesite eclogite (phengite absent) and three samples of phengite?bearing coesite eclogite (2-3 vol.% phengite), and measured the amount of water in garnet and omphacite in these samples, and also in two samples of phengite?bearing quartz eclogite (6-7 vol.% phengite, coesite absent). As coesite decreases in the mode, the amount of primary structural water stored in the whole rock, based on the nominally anhydrous minerals (NAMs), increases from 107/197 ppm H2O in the coesite eclogite to 157-253 ppm H2O in the phengite?bearing coesite eclogite to 391/444 ppm H2O in the quartz eclogite. In addition, there is molecular water in the NAMs and modal water in phengite. If the primary concentrations reflect differences in water sequestered during the late prograde evolution, the amount of fluid stored in the NAMs at the metamorphic peak was higher outside of the F1 fold noses. During exhumation from UHP conditions, where NAMs became H2O saturated, dehydroxylation would have generated a free fluid phase. Interstitial fluid in a garnet-clinopyroxene matrix at UHP conditions has dihedral angles >60°, so at equilibrium fluid will be trapped in isolated pores. However, outside the F1 fold noses strong D2 deformation likely promoted interconnection of fluid and migration along the developing S2 foliation, enabling conversion of some or all of the intergranular coesite into quartz. By contrast, the eclogite forming the F1 fold noses behaved as independent rigid bodies within the composite S1-S2 foliation of the surrounding phengite?bearing quartz?rich schists. Primary structural water concentrations in the coesite eclogite are so low that H2O saturation of the NAMs is unlikely to have occurred. This inherited drier environment in the F1 fold noses was maintained during exhumation by deformation partitioning and strain localization in the schists, and the fold noses remained immune to grain?scale fluid infiltration from outside allowing coesite to survive. The amount of inherited primary structural water and the effects of strain partitioning are important variables in the survival of coesite during exhumation of deeply subducted continental crust. Evidence of UHP metamorphism may be preserved in similar isolated structural settings in other collisional orogens.
DS201811-2580
2018
Brown, M.Hawkesworth, C.J., Brown, M.Earth dynamics and the development of plate tectonics.Philosophical Transactions Royal Society A, Vol. A376: doi://dx.doi.org/10.1098/rsta.2018.0228 5p.Mantleplate tectonics

Abstract: "Why does Earth have plate tectonics?" stands among the top research questions in the Earth Sciences. Plate tectonics developed in the last 4 billion years. This meeting will explore the evidence for the development of plate tectonics, contrast the terrestrial record with those from neighbouring planets, evaluate the conditions required for plate tectonics, and discuss implications for environmental conditions and development of the biosphere.
DS201903-0522
2019
Brown, M.Johnson, T.E., Kirkland, C.L., Gardiner, C.L., Gardiner, N.J., Brown, M., Smithies, R.H., Santosh, M.Secular change in TTG compositions: implications for the evolution of Archean geodynamics.Earth and Planetary Science Letters, Vol. 505, pp. 65-75.Mantlegeothermometry

Abstract: It is estimated that around three quarters of Earth's first generation continental crust had been produced by the end of the Archaean Eon, 2.5 billion years ago. This ancient continental crust is mostly composed of variably deformed and metamorphosed magmatic rocks of the tonalite-trondhjemite-granodiorite (TTG) suite that formed by partial melting of hydrated mafic rocks. However, the geodynamic regime under which TTG magmas formed is a matter of ongoing debate. Using a filtered global geochemical dataset of 563 samples with ages ranging from the Eoarchaean to Neoarchaean (4.0-2.5 Ga), we interrogate the bulk rock major oxide and trace element composition of TTGs to assess evidence for secular change. Despite a high degree of scatter in the data, the concentrations or ratios of several key major oxides and trace elements show statistically significant trends that indicate maxima, minima and/or transitions in the interval 3.3-3.0 Ga. Importantly, a change point analysis of K2O/Na2O, Sr/Y and LaN/YbN demonstrates a statistically significant (>99% confidence) change during this 300 Ma period. These shifts may be linked to a fundamental change in geodynamic regime around the peak in upper mantle temperatures from one dominated by non-uniformitarian, deformable stagnant lid processes to another dominated by the emergence of global mobile lid or plate tectonic processes by the end of the Archaean. A notable change is also evident at 2.8-2.7 Ga that coincides with a major jump in the rate of survival of metamorphic rocks with contrasting thermal gradients, which may relate to the emergence of more potassic continental arc magmas and an increased preservation potential during collisional orogenesis. In many cases, the chemical composition of TTGs shows an increasing spread through the Archaean, reflecting the irreversible differentiation of the lithosphere.
DS201906-1333
2019
Brown, M.Perchuk, A.L., Zakharov, V.S., Gerya, T.V., Brown, M.Hotter mantle but colder subduction in the Precambrian: what are the implications?Precambrian Research, Vol. 330, pp. 20-34.Mantlesubduction

Abstract: On contemporary Earth, subduction recycles mafic oceanic crust and associated volatile elements, creating new silicic continental crust in volcanic arcs. However, if the mantle was hotter in the Precambrian, the style of subduction, the depth of devolatilization and the formation of silicic continental crust may have been different. Consequently, the generation of the tonalite-trondhjemite-granodiorite (TTG) suite, which is characteristic of Archean crust, may not have been related to subduction. Here, we use a two-dimensional numerical magmatic-thermomechanical model to investigate intraoceanic subduction for contemporary mantle conditions and at higher mantle temperatures, as appropriate to the Precambrian. In each case, we characterize the thermal structure of the subducting plate and investigate magma compositions and production rates. We use these results to assess the potential growth of silicic continental crust associated with intraoceanic subduction at different mantle temperatures. For the Precambrian, in a set of experiments with ?T?=?150?K and decreasing subducting plate velocity, we find that the contemporary style of subduction was preceded by an arc-free regime dominated by rapid trench rollback and vigorous upwelling of asthenospheric mantle into the space created above the retreating slab. In this regime, formation of magmas by fluid-fluxed melting of the mantle is suppressed. Instead, decompression melting of upwelling asthenospheric mantle results in the widespread development of voluminous plateau-like basaltic magmas. In addition, retreating subduction at higher mantle temperature causes faster descent of the downgoing slab, leads to colder thermal gradients, similar to those associated with active subduction in the western Pacific today, and suppresses melting of the basaltic crust, limiting production of silicic (adakite-like) magmas. With increasing maturity of the subduction system, retreat of the subducting plate ceases, the role of decompression melting strongly decreases and fluid-fluxed melting of the mantle coupled with melting of the hydrated slab begins to produce basaltic and felsic arc volcanic rocks similar to those formed during contemporary subduction. In an additional series of individual experiments at various ?T, an increase of the mantle temperature above ?T?=?150?K leads to episodic and short-lived subduction accompanied by limited production of silicic continental crust. The results of our experimental study demonstrate that a hotter mantle in the Precambrian changes dramatically both the slab dynamics and the processes of magma generation and crustal growth associated with intraoceanic subduction zones. These changes may preclude growth of the early Precambrian silicic continental crust by processes that were dominantly similar to those associated with contemporary subduction.
DS201907-1577
2019
Brown, M.Sobolev, S.V., Brown, M.Surface erosion events controlled the evolution of plate tectonics on Earth.Nature, Vol. 570, June 6, p. 52-57.Mantleplate tectonics

Abstract: Plate tectonics is among the most important geological processes on Earth, but its emergence and evolution remain unclear. Here we extrapolate models of present-day plate tectonics to the past and propose that since about three billion years ago the rise of continents and the accumulation of sediments at continental edges and in trenches has provided lubrication for the stabilization of subduction and has been crucial in the development of plate tectonics on Earth. We conclude that the two largest surface erosion and subduction lubrication events occurred after the Palaeoproterozoic Huronian global glaciations (2.45 to 2.2 billion years ago), leading to the formation of the Columbia supercontinent, and after the Neoproterozoic ‘snowball’ Earth glaciations (0.75 to 0.63 billion years ago). The snowball Earth event followed the ‘boring billion’—a period of reduced plate tectonic activity about 1.75 to 0.75 billion years ago that was probably caused by a shortfall of sediments in trenches—and it kick-started the modern episode of active plate tectonics.
DS201909-2026
2019
Brown, M.Brown, M., Johnson, T.Metamorphism and the evolution of subduction on Earth.American Mineralogist, Vol. 104, pp. 1065-1082.Mantlesubduction

Abstract: Subduction is a component of plate tectonics, which is widely accepted as having operated in a manner similar to the present-day back through the Phanerozoic Eon. However, whether Earth always had plate tectonics or, if not, when and how a globally linked network of narrow plate boundaries emerged are matters of ongoing debate. Earth's mantle may have been as much as 200-300 °C warmer in the Mesoarchean compared to the present day, which potentially required an alternative tectonic regime during part or all of the Archean Eon. Here we use a data set of the pressure (P), temperature (T), and age of metamorphic rocks from 564 localities that vary in age from the Paleoarchean to the Cenozoic to evaluate the petrogenesis and secular change of metamorphic rocks associated with subduction and collisional orogenesis at convergent plate boundaries. Based on the thermobaric ratio (T/P), metamorphic rocks are classified into three natural groups: high T/P type (T/P > 775 °C/GPa, mean T/P ~1105 °C/GPa), intermediate T/P type (T/P between 775 and 375 °C/GPa, mean T/P ~575 °C/GPa), and low T/P type (T/P < 375 °C/GPa, mean T/P ~255 °C/GPa). With reference to published thermal models of active subduction, we show that low T/P oceanic metamorphic rocks preserving peak pressures >2.5 GPa equilibrated at P-T conditions similar to those modeled for the uppermost oceanic crust in a wide range of active subduction environments. By contrast, those that have peak pressures <2.2 GPa may require exhumation under relatively warm conditions, which may indicate subduction of young oceanic lithosphere or exhumation during the initial stages of subduction. However, low T/P oceanic metamorphic rocks with peak pressures of 2.5-2.2 GPa were exhumed from depths where, in models of active subduction, the slab and overriding plate change from being decoupled (at lower P) to coupled (at higher P), possibly suggesting a causal relationship. In relation to secular change, the widespread appearance of low T/P metamorphism in the Neoproterozoic represents a “modern” style of cold collision and deep slab breakoff, whereas rare occurrences of low T/P metamorphism in the Paleoproterozoic may reveal atypical localized regions of cold collision. Low T/P metamorphism is not known from the Archean geological record, but the absence of blueschists in particular is unlikely to reflect secular change in the composition of the oceanic crust. In addition, the premise that the formation of lawsonite requires abnormally low thermal gradients and the postulate that oceanic subduction-related rocks register significantly lower maximum pressures than do continental subduction-related rocks, and imply different mechanisms of exhumation, are not supported. The widespread appearance of intermediate T/P and high T/P metamorphism at the beginning of the Neoarchean, and the subsequent development of a clear bimodality in tectono-thermal environments are interpreted to be evidence of the stabilization of subduction during a transition to a globally linked network of narrow plate boundaries and the emergence of plate tectonics.
DS201909-2046
2019
Brown, M.Holder, R.M., Viete, D.R., Brown, M., Johnson, T.E.Metamorphism and the evolution of plate tectonics.Nature, doi.org/10.1038/ s41586-019-1462-2 2p.Mantleplate tectonics

Abstract: Earth’s mantle convection, which facilitates planetary heat loss, is manifested at the surface as present-day plate tectonics1. When plate tectonics emerged and how it has evolved through time are two of the most fundamental and challenging questions in Earth science1,2,3,4. Metamorphic rocks—rocks that have experienced solid-state mineral transformations due to changes in pressure (P) and temperature (T)—record periods of burial, heating, exhumation and cooling that reflect the tectonic environments in which they formed5,6. Changes in the global distribution of metamorphic (P, T) conditions in the continental crust through time might therefore reflect the secular evolution of Earth’s tectonic processes. On modern Earth, convergent plate margins are characterized by metamorphic rocks that show a bimodal distribution of apparent thermal gradients (temperature change with depth; parameterized here as metamorphic T/P) in the form of paired metamorphic belts5, which is attributed to metamorphism near (low T/P) and away from (high T/P) subduction zones5,6. Here we show that Earth’s modern plate tectonic regime has developed gradually with secular cooling of the mantle since the Neoarchaean era, 2.5 billion years ago. We evaluate the emergence of bimodal metamorphism (as a proxy for secular change in plate tectonics) using a statistical evaluation of the distributions of metamorphic T/P through time. We find that the distribution of metamorphic T/P has gradually become wider and more distinctly bimodal from the Neoarchaean era to the present day, and the average metamorphic T/P has decreased since the Palaeoproterozoic era. Our results contrast with studies that inferred an abrupt transition in tectonic style in the Neoproterozoic era (about 0.7 billion years ago1,7,8) or that suggested that modern plate tectonics has operated since the Palaeoproterozoic era (about two billion years ago9,10,11,12) at the latest.
DS201910-2245
2019
Brown, M.Brown, M., Johnson, T.E.Metamorphism and evolution of subduction on Earth.American Mineralogist, Vol. 104, 8, pp. 1065-1082.Mantlesubduction

Abstract: Subduction is a component of plate tectonics, which is widely accepted as having operated in a manner similar to the present-day back through the Phanerozoic Eon. However, whether Earth always had plate tectonics or, if not, when and how a globally linked network of narrow plate boundaries emerged are matters of ongoing debate. Earth's mantle may have been as much as 200-300 °C warmer in the Mesoarchean compared to the present day, which potentially required an alternative tectonic regime during part or all of the Archean Eon. Here we use a data set of the pressure (P), temperature (T), and age of metamorphic rocks from 564 localities that vary in age from the Paleoarchean to the Cenozoic to evaluate the petrogenesis and secular change of metamorphic rocks associated with subduction and collisional orogenesis at convergent plate boundaries. Based on the thermobaric ratio (T/P), metamorphic rocks are classified into three natural groups: high T/P type (T/P > 775 °C/GPa, mean T/P ~1105 °C/GPa), intermediate T/P type (T/P between 775 and 375 °C/GPa, mean T/P ~575 °C/GPa), and low T/P type (T/P < 375 °C/GPa, mean T/P ~255 °C/GPa). With reference to published thermal models of active subduction, we show that low T/P oceanic metamorphic rocks preserving peak pressures >2.5 GPa equilibrated at P-T conditions similar to those modeled for the uppermost oceanic crust in a wide range of active subduction environments. By contrast, those that have peak pressures <2.2 GPa may require exhumation under relatively warm conditions, which may indicate subduction of young oceanic lithosphere or exhumation during the initial stages of subduction. However, low T/P oceanic metamorphic rocks with peak pressures of 2.5-2.2 GPa were exhumed from depths where, in models of active subduction, the slab and overriding plate change from being decoupled (at lower P) to coupled (at higher P), possibly suggesting a causal relationship. In relation to secular change, the widespread appearance of low T/P metamorphism in the Neoproterozoic represents a “modern” style of cold collision and deep slab breakoff, whereas rare occurrences of low T/P metamorphism in the Paleoproterozoic may reveal atypical localized regions of cold collision. Low T/P metamorphism is not known from the Archean geological record, but the absence of blueschists in particular is unlikely to reflect secular change in the composition of the oceanic crust. In addition, the premise that the formation of lawsonite requires abnormally low thermal gradients and the postulate that oceanic subduction-related rocks register significantly lower maximum pressures than do continental subduction-related rocks, and imply different mechanisms of exhumation, are not supported. The widespread appearance of intermediate T/P and high T/P metamorphism at the beginning of the Neoarchean, and the subsequent development of a clear bimodality in tectono-thermal environments are interpreted to be evidence of the stabilization of subduction during a transition to a globally linked network of narrow plate boundaries and the emergence of plate tectonics.
DS201910-2265
2019
Brown, M.Holder, R., Viete, D.R., Brown, M., Johnson, T.E.Metamorphism and evolution of plate tectonics.Nature, Vol. 572, 7769, pp. 1-4.Mantleplate tectonics

Abstract: Earth’s mantle convection, which facilitates planetary heat loss, is manifested at the surface as present-day plate tectonics1. When plate tectonics emerged and how it has evolved through time are two of the most fundamental and challenging questions in Earth science1,2,3,4. Metamorphic rocks—rocks that have experienced solid-state mineral transformations due to changes in pressure (P) and temperature (T)—record periods of burial, heating, exhumation and cooling that reflect the tectonic environments in which they formed5,6. Changes in the global distribution of metamorphic (P, T) conditions in the continental crust through time might therefore reflect the secular evolution of Earth’s tectonic processes. On modern Earth, convergent plate margins are characterized by metamorphic rocks that show a bimodal distribution of apparent thermal gradients (temperature change with depth; parameterized here as metamorphic T/P) in the form of paired metamorphic belts5, which is attributed to metamorphism near (low T/P) and away from (high T/P) subduction zones5,6. Here we show that Earth’s modern plate tectonic regime has developed gradually with secular cooling of the mantle since the Neoarchaean era, 2.5 billion years ago. We evaluate the emergence of bimodal metamorphism (as a proxy for secular change in plate tectonics) using a statistical evaluation of the distributions of metamorphic T/P through time. We find that the distribution of metamorphic T/P has gradually become wider and more distinctly bimodal from the Neoarchaean era to the present day, and the average metamorphic T/P has decreased since the Palaeoproterozoic era. Our results contrast with studies that inferred an abrupt transition in tectonic style in the Neoproterozoic era (about 0.7 billion years ago1,7,8) or that suggested that modern plate tectonics has operated since the Palaeoproterozoic era (about two billion years ago9,10,11,12) at the latest.
DS202005-0723
2020
Brown, M.Brown, M., Johnson, T., Gardiner, N.J.Plate tectonics and the Archean Earth.Annual Review of Earth and Planetary Sciences, Vol. 48, 30p. pdfMantlesubduction, metamorphism

Abstract: If we accept that a critical condition for plate tectonics is the creation and maintenance of a global network of narrow boundaries separating multiple plates, then to argue for plate tectonics during the Archean requires more than a local record of subduction. A case is made for plate tectonics back to the early Paleoproterozoic, when a cycle of breakup and collision led to formation of the supercontinent Columbia, and bimodal metamorphism is registered globally. Before this, less preserved crust and survivorship bias become greater concerns, and the geological record may yield only a lower limit on the emergence of plate tectonics. Higher mantle temperature in the Archean precluded or limited stable subduction, requiring a transition to plate tectonics from another tectonic mode. This transition is recorded by changes in geochemical proxies and interpreted based on numerical modeling. Improved understanding of the secular evolution of temperature and water in the mantle are key targets for future research. 1) Higher mantle temperature in the Archean precluded or limited stable subduction, requiring a transition to plate tectonics from another tectonic mode. 2) Plate tectonics can be demonstrated on Earth since the early Paleoproterozoic (since c. 2.2 Ga), but before the Proterozoic Earth's tectonic mode remains ambiguous. 3) The Mesoarchean to early Paleoproterozoic (3.2-2.3 Ga) represents a period of transition from an early tectonic mode (stagnant or sluggish lid) to plate tectonics. 4) The development of a global network of narrow boundaries separating multiple plates could have been kick-started by plume-induced subduction.
DS202005-0724
2020
Brown, M.Brown, M., Kirkland, C.L., Johnson, T.E.Evolution of geodynamics since the Archean: significant change at the dawn of the Phanerozoic.Geology, Vol. 48, 5, pp. 488-492.Globalgeodynamics

Abstract: A time-series analysis of thermobaric ratios (temperature/pressure [T/P]) for Paleoarchean to Cenozoic metamorphic rocks identified significant shifts in mean T/P that may be related to secular change in the geodynamics on Earth. Thermobaric ratios showed significant (>95% confidence) change points at 1910, 902, 540, and 515 Ma, recording drops in mean T/P, and at 1830, 604, and 525 Ma, recording rises in mean T/P. Highest mean T/P occurred during the Mesoproterozoic, and lowest mean T/P occurred from the Cambrian to the Oligocene. Correlated changes were seen between T/P and global data sets of time-constrained hafnium (Hf) and oxygen (O) isotope compositions in zircon. The range of correlated variation in T/P, Hf, and O was larger during the formation of Rodinia than Columbia. Large changes and a wide range for these variables continued through the Phanerozoic, during which a statistically significant 83 m.y. frequency of T/P excursions recorded the high tempo of orogenic activity associated with the separation, migration, and accretion of continental terranes during the formation of Pangea. Since the early Tonian, the decreasing mean T/P of metamorphism, widespread appearance of blueschist and ultrahigh-pressure metamorphism, and wide fluctuations in Hf and O isotope compositions document a change to the modern plate-tectonic regime, characterized by widespread continental subduction and deeper slab breakoff than in the Proterozoic.
DS202007-1126
2020
Brown, M.Brown, M., Johnson, T., Gardiner, N.J.Plate tectonics and the Archean Earth.Annual Review of Earth and Planetary Sciences, Vol. 48, 1, pp. 291-320.Mantletectonics

Abstract: If we accept that a critical condition for plate tectonics is the creation and maintenance of a global network of narrow boundaries separating multiple plates, then to argue for plate tectonics during the Archean requires more than a local record of subduction. A case is made for plate tectonics back to the early Paleoproterozoic, when a cycle of breakup and collision led to formation of the supercontinent Columbia, and bimodal metamorphism is registered globally. Before this, less preserved crust and survivorship bias become greater concerns, and the geological record may yield only a lower limit on the emergence of plate tectonics. Higher mantle temperature in the Archean precluded or limited stable subduction, requiring a transition to plate tectonics from another tectonic mode. This transition is recorded by changes in geochemical proxies and interpreted based on numerical modeling. Improved understanding of the secular evolution of temperature and water in the mantle is a key target for future research.
DS202102-0186
2021
Brown, M.Feng, P., Wang, L., Brown, M., Johnson, T.E., Kylander-Clark, A., Piccoli, P.M.Partial melting of ultrahigh pressure eclogite by omphacite-breakdown facilitates exhumation of deeply-subducted crust.Earth and Planetary Science Letters, Vol. 554, doi.org/10.1016/ j.epsl.2020. 116664 13p. PdfMantleeclogite

Abstract: Results from numerical modelling and experimental petrology have led to the hypothesis that partial melting was important in facilitating exhumation of ultrahigh-pressure (UHP) metamorphic rocks from mantle depths. However, the melting reactions responsible are rarely well-documented from natural examples. Here we report microstructural features and compositional data that indicate in situ partial melting dominated by breakdown of omphacite in UHP eclogite from the Sulu belt, China. Diagnostic microstructures include: (i) the presence of in situ leucosome pockets composed of plagioclase, euhedral amphibole, minor K-feldspar and epidote within host zoisite- and phengite-bearing eclogite; (ii) skeletal omphacite within the leucosome pockets that has a lower jadeite content (25-45 mol.%) than rock-forming omphacite (39-54 mol.%); and, (iii) seams of Na-rich plagioclase that extend along grain boundaries separating phengite, quartz and zoisite, and which commonly exhibit low dihedral angles where they terminate at triple grain-boundary junctions. Major oxide proportions of 57 leucosome pockets, calculated using mineral modes and compositions, yield leucodiorite bulk compositions characterized by intermediate SiO2, high Al2O3 and Na2O, and low K2O contents. In primitive mantle-normalised trace element diagrams, the leucosome pockets show enrichment in large ion lithophile elements, U, Pb, Zr, Hf and Ti, but depletion in Th and Ta, patterns that are similar to those of rock-forming omphacite. Rather than forming predominantly by breakdown of phengite and/or zoisite, as widely proposed in the literature, the leucosome pockets have petrographic characteristics and major oxide and trace element compositions that are consistent with partial melting dominated by omphacite breakdown. Based on conventional thermobarometry, the eclogite was exhumed from pressure-temperature (P-T) conditions of 3.6-3.1 GPa and 900-840 °C. Partial melting led to the formation of the leucosome pockets, which equilibrated with the rims of surrounding rock-forming garnet and pyroxene during crystallisation. Conventional thermobarometry using rim compositions yields P-T conditions of 1.6-1.2 GPa and 780-690 °C, broadly consistent with calculated phase equilibria and Ti-in-zircon temperatures from zircon overgrowths. Weighted mean ages of ca 217-214 Ma from thin overgrowths on zircon are interpreted to record melt crystallisation. This study provides insight into an overlooked mechanism by which eclogites partially melt during exhumation from UHP conditions, and permits a better understanding of the processes that assist deeply-subducted continental crust to return to shallower depths.
DS200412-0797
2004
Brown, N.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
DS200512-1112
2005
Brown, O.Utting, D., Little, E., Brown, O., Young, M., Taylor, J.Glacial geology, drift bedrock prospecting and related remote sensing application on northern Baffin Island, Nunavut.Geological Survey of Canada Open File, OF 4736 $ 15.00 1 colour posterCanada, NunavutRemote sensing
DS200512-0117
2005
Brown, O.H.Brown, O.H., Utting, D.J., Little, E.C., Grunsky, E.C., Harris, J., Peter, P.Remote predictive mapping of surficial geology in Nunavut using supervised classification techniques of Land sat and RADARSAT I data.GAC Annual Meeting Halifax May 15-19, Abstract 1p.Canada, NunavutRemote sensing
DS1989-0184
1989
Brown, P.E.Brown, P.E.FLINCOR: a microcomputer program for the reduction and investigation of fluid-inclusion dataAmerican Mineralogist, Vol. 74, No. 11, 12, November-December, pp. 1390-1393GlobalComputer program, Program -FLINCOR., Fluid inclusions -general
DS1990-0734
1990
Brown, P.E.Hutton, D.H.W., Dempster, T.J., Brown, P.E., Becker, S.D.A new mechanism of granite emplacement: intrusion in active extensional shear zonesNature, Vol. 343, February 1, pp. 452-455GlobalGranite, Shear zones
DS1999-0097
1999
Brown, P.E.Brown, P.E., Evans, I.B., Becker, S.M.Alkaline basaltic volcanism in the Tertiary of central East Greenland - the Trekantnunatakker.Transactions Royal Society. Edin. Earth Sci., Vol. 90, pp. 165-72.GreenlandPicrites, alkali basalts, Geochronology
DS2000-0115
2000
Brown, P.G.Brown, P.G., Hildebrand, A.R., Mazur, T.R.The fall, recovery, orbit and composition of the Taglish Lake meteorite: A new type of carbonaceous..Science, Vol. 290, No. 5490, Oct. 13, pp. 320-4.Northwest TerritoriesChondrites
DS1986-0016
1986
Brown, R.Allsopp, H.L., Smith, C.B., Bristow, J.W., Brown, R., Kramers, J.D.A review of radiometric dating methods applicable to kimberlites And related rocksProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 109-111South AfricaGeochronology
DS1989-0021
1989
Brown, R.Allsopp, H.L., Bristow, J.W., Smith, C.B., Brown, R., GleadowA summary of radiometric dating methods applicable To kimberlites and realted rocksGeological Society of Australia Inc. Blackwell Scientific Publishing, Special, No. 14, Vol. 1, pp. 343-357Southern AfricaAge emplacement, Radiometric, Geochronolog
DS1994-0218
1994
Brown, R.Brown, R., Gallagher, K., Duane, M.A quantitative assessment of the effects of magmatism on the thermal history of the Karoo sediment sequenceJournal of African Earth Sciences, Vol. 18, No. 3, April pp. 245-254South AfricaMagmatism, Karoo sedimentology
DS1994-0219
1994
Brown, R.Brown, R., Gallagher, K., Duane, M.A quantitative assessment of effects of magmatism on the thermal history Of the Karoo sedimentary sequenceJourn. African Earth Sciences, Vol. 18, No. 3, pp. 227-243South AfricaMagmatism, Paleotemperatures
DS1994-1714
1994
Brown, R.Stuwe, K., White, L., Brown, R.The influence of eroding topography on steady state isotherms. application to fission track analysisEarth and Planetary Science Letters, Vol. 124, No. 1/4, June pp. 63-74GlobalGeothermometry
DS1996-0182
1996
Brown, R.Brown, R., Gallagher, K., De Wit, M., Gleadow, A.The Cratonic conundrum: does old+cold+thick=stable?Australia Nat. University of Diamond Workshop July 29, 30. abstract, 1p.South Africa, BrazilCraton, Paleotemperatures
DS201012-0074
2010
Brown, R.Brown, R., White, R.W., Sandiford, M.On the importance of minding one's Ps and Ts: metamorphic processes and quantitative petrology.Journal of Metamorphic Geology, Vol. 28, 6, pp. 561-567.TechnologyUHP
DS201112-0120
2011
Brown, R.Brown, R.The Holocene Igwisi Hills (volcanoes) kimberlite lecture. 3 He dating olivine crystals 10 ka *** note for informative information only.University of British Columbia , n/aAfrica, TanzaniaNews item - Igwisi Hills
DS201412-0079
2014
Brown, R.Buisman, I., Sparks, R.S.J., Brown, R., Manya, S.Microanalysis of olivine chemistry of exceptionally young kimberlite of the Igwisi Hills, volcano, Tanzania.Volcanic and Magmatic Studies Group meeting, Poster Held Jan. 6-8. See minsoc websiteAfrica, TanzaniaIgwisi
DS201502-0046
2014
Brown, R.Brown, R., Summerfield, M., Gleadow, A., Gallagher, K., Carter, A., Beucher, R., Wildman, M.Intracontinental deformation in southern Africa during the Late Cretaceous.Journal of African Earth Sciences, Vol. 100, pp. 20-41.Africa, NamibiaGeothermometry

Abstract: Intracontinental deformation accommodated along major lithospheric scale shear zone systems and within associated extensional basins has been well documented within West, Central and East Africa during the Late Cretaceous. The nature of this deformation has been established by studies of the tectonic architecture of sedimentary basins preserved in this part of Africa. In southern Africa, where the post break-up history has been dominated by major erosion, little evidence for post-break-up tectonics has been preserved in the onshore geology. Here we present the results of 38 new apatite fission track analyses from the Damara region of northern Namibia and integrate these new data with our previous results that were focused on specific regions or sections only to comprehensively document the thermo-tectonic history of this region since continental break-up in the Early Cretaceous. The apatite fission track ages range from 449 ± 20 Ma to 59 ± 3 Ma, with mean confined track lengths between 14.61 ± 0.1 ?m (SD 0.95 ?m) to 10.83 ± 0.33 ?m (SD 2.84 ?m). The youngest ages (c. 80–60 Ma) yield the longest mean track lengths, and combined with their spatial distribution, indicate major cooling during the latest Cretaceous. A simple numerical thermal model is used to demonstrate that this cooling is consistent with the combined effects of heating caused by magmatic underplating, related to the Paraná-Etendeka continental flood volcanism associated with rifting and the opening of the South Atlantic, and enhanced erosion caused by major reactivation of major lithospheric structures within southern Africa during a key period of plate kinematic change that occurred in the South Atlantic and SW Indian ocean basins between 87 and 56 Ma. This phase of intraplate tectonism in northern Namibia, focused in discrete structurally defined zones, is coeval with similar phases elsewhere in Africa and suggests some form of trans-continental linkage between these lithospheric zones.
DS201611-2113
2016
Brown, R.Happe Kazanzu, C., Linol, B., de Wit, M.J., Brown, R., Persano, R., Stuart, F.M.From source to sink in central Gondwana: exhumation of the Precambrian basement rocks of Tanzania and sediment accumulation in the adjacent Congo basin.Tectonics, Vol. 35, 9, pp. 2034-2051.Africa, TanzaniaGeodynamics

Abstract: Apatite fission track (AFT) and (U-Th)/He (AHe) thermochronometry data are reported and used to unravel the exhumation history of crystalline basement rocks from the elevated (>1000?m above sea level) but low-relief Tanzanian Craton. Coeval episodes of sedimentation documented within adjacent Paleozoic to Mesozoic basins of southern Tanzania and the Congo basin of the Democratic Republic of Congo indicate that most of the cooling in the basement rocks in Tanzania was linked to erosion. Basement samples were from an exploration borehole located within the craton and up to 2200?m below surface. Surface samples were also analyzed. AFT dates range between 317?±?33?Ma and 188?±?44?Ma. Alpha (Ft)-corrected AHe dates are between 433?±?24?Ma and 154?±?20?Ma. Modeling of the data reveals two important periods of cooling within the craton: one during the Carboniferous-Triassic (340-220?Ma) and a later, less well constrained episode, during the late Cretaceous. The later exhumation is well detected proximal to the East African Rift (70?Ma). Thermal histories combined with the estimated geothermal gradient of 9°C/km constrained by the AFT and AHe data from the craton and a mean surface temperature of 20°C indicate removal of up to 9?±?2?km of overburden since the end of Paleozoic. The correlation of erosion of the craton and sedimentation and subsidence within the Congo basin in the Paleozoic may indicate regional flexural geodynamics of the lithosphere due to lithosphere buckling induced by far-field compressional tectonic processes and thereafter through deep mantle upwelling and epeirogeny tectonic processes.
DS1995-0368
1995
Brown, R.B.Cremeens, D.L., Brown, R.B., Huddleston, J.H.Whole regolith pedologySoil Society of America, $ 24.00United StatesBook -ad, Regolith pedology
DS200612-0183
2006
Brown, R.J.Brown, R.J., Gernon, T., Tshutlhedi, J.Insights into the eruption of the Jwaneng Centre lobe kimberlite pipe.Emplacement Workshop held September, 5p. extended abstractAfrica, BotswanaDeposit - Jwaneng - lithofacies assemblages
DS200612-0184
2006
Brown, R.J.Brown, R.J., Tait, M., Field, M., Sparks, R.S.J.Progressive enlargement and infill of a kimberlite pipe: K2 pipe, Venetia kimberlite field, Limpopo Province, South Africa.Emplacement Workshop held September, 5p. extended abstractAfrica, South AfricaDeposit - K2, Venetia - lithofacies assemblages
DS200612-0448
2006
Brown, R.J.Gernon, T.M., Sparks, R.S.J., Brown, R.J., Field, M.Gas segregation pipes in kimberlite: evidence for fluidisation at Orapa south pipe, Botswana.Emplacement Workshop held September, 5p. extended abstractAfrica, BotswanaDeposit - Orapa - fluidisation, structure
DS200612-1341
2006
Brown, R.J.Sparks, R.J.S., Baker, L., Brown, R.J., Field, M., Schumacher, J., Stripp, G., Walters, A.Dynamical constraints on kimberlite volcanism.Journal of Volcanology and Geothermal Research, in press availableAfrica, South AfricaGeodynamics, eruptions, diamonds, models, fluidization
DS200612-1406
2006
Brown, R.J.Tait, M.A., Brown, R.J., Mnyama, A.Internal architecture of the Venetia K1 kimberlite: a new geological model and implications for kimberlite emplacement processes, Venetia mine, Limpopo RSA.Emplacement Workshop held September, 5p. abstractAfrica, South AfricaDeposit - Venetia, petrography, facies
DS200612-1505
2006
Brown, R.J.Walters, A.L., Phillips, J.C., Brown, R.J., Field, M., Gernon, T., Stripp, G., Sparks, R.S.J.The role of fluidisation in the formation of volcaniclastic kimberlite: grain size observations and experimental investigation.Journal of Volcanology and Geothermal Research, in press availableAfrica, South AfricaDeposit - Venetia, explosive eruption, fluidization
DS200712-0119
2007
Brown, R.J.Brown, R.J., Kavanagh, J., Sparks, R.S.J., Tait, M., Field, M.Mechanically disrupted and chemically weakened zones in segmented dike system cause vent localization: evidence from kimberlite volcanic systems.Geology, Vol. 35, 9, pp. 815-818.Africa, South AfricaDeposit - Swartruggems dike swarm
DS200812-0145
2008
Brown, R.J.Brown, R.J., Buse, B., Sparks, R.S.J., Field, M.On the welding of pyroclasts from very low viscosity magmas: examples from kimberlite volcanoes. Venetia K2, BK9 Damtshaa (Orapa)Journal of Geology, Vol. 117, pp. 354-374.Africa, South Africa, BotswanaClassification - coherent kimberlite
DS200812-0146
2008
Brown, R.J.Brown, R.J., Field, M., Gernon, T., Gilbertson, M., Sparks, R.S.J.Problems with in vent column collapse model for the emplacement of massive volcaniclastic kimberlite. Discussion of Porritt - Fox kimberliteJournal of Volcanology and Geothermal Research, in press available 8p.Canada, Northwest territoriesFox kimberlite petrology
DS200812-0147
2008
Brown, R.J.Brown, R.J., Gernon, T., Stiefenhofer, J., Field, M.Geological constraints on the eruption of the Jwaneng Centre kimberlite pipe, Botswana.Journal of Volcanology and Geothermal Research, Vol. 174, 1-3, pp. 195-208.Africa, BotswanaEplosive eruption, phreatomagmatism, fluidisation
DS200812-0148
2009
Brown, R.J.Brown, R.J., Tait, M., Field, M., Sparks, R.S.J.Geology of a complex kimberlite pipe ( K2 pipe), Venetia Mine, South Africa: insights into conduit processes during explosive ultrabasic eruptions.Bulletin Volcanology, Vol. 71, 1, pp. 95-112.Africa, South AfricaDeposit - Venetia
DS200812-1100
2007
Brown, R.J.Sparks, R.S., Brown, R.J., Field, M., Gilbertson, M.Kimberlite ascent and eruption.Nature, Vol. 450, 7172, p. E21.TechnologyClassification
DS200912-0224
2009
Brown, R.J.Fontana, G.P.,MacNiocaill, C., Brown, R.J., Sparks, S.R., Field, M., Gernon, T.M.Emplacement temperatures of pyroclastic and colcaniclastic deposits in kimberlite pipes in southern Africa: new constraints from paleomagnetic measurementsGAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyAfrica, Botswana, South AfricaDeposit - AK1, Orapa, K1, K2 Venetia
DS200912-0247
2009
Brown, R.J.Gernon, T.M., Fontana, G., Field, M., Sparks, R.S.J., Brown, R.J., Niocaill, C.M.Pyroclastic flow deposits from a kimberlite eruption: the Orapa south crater, Botswana.Lithos, In press available 13p.Africa, BotswanaDeposit - Orapa
DS200912-0337
2009
Brown, R.J.Jerram, D.A., Mock, A., Davis, G.R., Field, M., Brown, R.J.3D crystal size distributions: a case study quantifying olivine populations in kimberlites.Lithos, In press - available 30p.Africa, South AfricaDeposit - Venetia, Dutoitspan
DS201112-0331
2011
Brown, R.J.Fontana, G., Niocaill, C.M., Brown, R.J., Sparks, R.S.J., Field, M.Emplacement temperatures of pyroclastic and volcaniclastic deposits in kimberlite pipes in southern Africa.Bulletin Volcanology, In press available, 21p.Africa, South Africa, BotswanaPaleomagnetism
DS201212-0091
2012
Brown, R.J.Brown, R.J., Buisman, M.I., Fontana, G., Field, M., Mac Niocaill, C., Sparks, R.S.J., Stuart, F.M.Eruption of kimberlite magmas: physical volcanology, geomorphology and age of the youngest kimberlitic volcanoes known on Earth ( the Upper Pleistocene/Holocene Igwisi Hills volcanoes, Tanzania).Bulletin Volcanology, in press availableAfrica, TanzaniaDeposit - Igwisi
DS201212-0092
2012
Brown, R.J.Brown, R.J., Manya, S., Buisman, I., Fontana, G., Field, M., MacNiocaill, C., Sparks, R.S.J., Stuart, F.M.Eruption of kimberlite magmas: physical volcanology, geomrphology and age of the youngest kimberlitic volcanoes known on Earth ( the Upper Pleistocene-Holocene Igwisi Hills, volcanoes, Tanzania.Bulletin of Volcanology, Vol. 74, 7, pp. 1621-1643.Africa, TanzaniaIgwisi Hills
DS201212-0093
2012
Brown, R.J.Brown, R.J., Manya, S., Buisman, I., Sparks, R.S.J., Field, M., Stuart, F.M., Fontana, G.Physical volcanology, geomorphology, and cosmogenic 3HE dating of the youngest kimberlite volcanoes on Earth ( The Holocene Igwisi Hills, Volcanoes, Tanzania.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractAfrica, TanzaniaIgwisi Hills - geochronology
DS201212-0095
2012
Brown, R.J.Buisman, I., Sparks, R.S.J., Walter, M.J., Brown, R.J., Manya, S., Kavanagh, J.Olivine chemistry of exceptionally young ( Holocene) kimberlite of the Igwisi Hills volcano, Tanzania.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractAfrica, TanzaniaDeposit - Igwisi
DS201212-0233
2012
Brown, R.J.Gernon, T., Brown, R.J., Tait, M.A., Hincks, T.K.The origin of pellatal lapilli in explosive kimberlite eruptions.Nature Communcations, May 7p.Africa, South Africa, LesothoDeposit - Venetia, Letseng-la-Terae
DS201212-0234
2012
Brown, R.J.Gernon, T.M., Brown, R.J., Tait, N., Hinks, T.K.The origin of pellatal lapilli in explosive kimberlite eruptions.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractTechnologyPetrology
DS201212-0694
2012
Brown, R.J.Sparks, R.S.J., Buisman, I., Brooker, R., Brown, R.J., Field, M., Gernon, T., Kavanagh,J., Ogilvie-Harris, R., Schumacher, J.C.Dynamics of kimberlite magam ascent, intrusion and eruption.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractGlobalDiamond genesis
DS201312-0103
2013
Brown, R.J.Brown, R.J., Valentine, G.A.Physical characteristics of kimberlite and basaltic intraplate volcanism and implications of a biased kimberlite record.Geological Society of America Bulletin, Vol. 125, pp. 1224-1238.GlobalKimberlite volcanism and erosion depths
DS202007-1144
2020
Brown, R.J.Haddock, D., Manya, S., Brown, R.J., Jones, T.J., Wadsworth, F.B., Dobson, K.J., Gernon, T.M.Syn-eruptive agglutination of kimberlite volcanic ash. PyroclastsVolcanica, Vol. 3, 1, pp. 169-182. PdfAfrica, Tanzaniadeposit - Igwisi Hills

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

Abstract: Pyroclastic deposits of the Holocene Igwisi Hills kimberlite volcanoes, Tanzania, preserve unequivocal evidence for rapid, syn-eruptive agglutination. The unusual pyroclasts are composed of ash-sized particles agglutinated to each other by thin necks. The textures suggest the magma was disrupted into droplets during ascent. Collisions between particles occurred within a volcanic plume and on deposition within the conduit to form a weakly agglutinated, porous pyroclastic deposit. Theoretical considerations indicate that agglutination occurred over short timescales. Agglutinated clasts were entrained into weak volcanic plumes and deposited around the craters. Our results support the notion that agglutination can occur during kimberlite eruptions, and that some coherent, dense rocks in ancient kimberlite pipes interpreted as intrusive rocks could instead represent agglutinated pyroclastic rocks. Differentiating between agglutinated pyroclastic rocks and effusive or intrusive rocks in kimberlite pipes is important because of the potential effects that pyroclastic processes might have on diamond concentrations in deposits.
DS202205-0690
2022
Brown, R.J.Jones, T.J., Russell, J.K., Brown, R.J., Hollendonner, L.Melt stripping and agglutination of pyroclasts during the explosive eruption of low viscosity magmas.Nature Communications, 10.1038/s41467-022-28633-w 12p. PdfMantlemagmatism

Abstract: Volcanism on Earth and on other planets and satellites is dominated by the eruption of low viscosity magmas. During explosive eruption, high melt temperatures and the inherent low viscosity of the fluidal pyroclasts allow for substantial post-fragmentation modification during transport obscuring the record of primary, magmatic fragmentation processes. Here, we show these syn-eruption modifications, in the form of melt stripping and agglutination, to be advantageous for providing fundamental insights into lava fountain and jet dynamics, including eruption velocities, grain size distributions and melt physical properties. We show how enigmatic, complex pyroclasts termed pelletal lapilli form by a two-stage process operating above the magmatic fragmentation surface. Melt stripping from pyroclast surfaces creates a spray of fine melt droplets whilst sustained transport in the fountain allows for agglutination and droplet scavenging, thereby coarsening the grain size distribution. We conclude with a set of universal regime diagrams, applicable for all fluidal fountain products, that link fundamental physical processes to eruption conditions and melt physical properties.
DS1991-0186
1991
Brown, R.L.Brown, R.L., Everett, J.R.Arbuckle exploration: acquisition through seismic windows of the Ouachita thrust zoneGeophysics-The leading Edge of Exploration, Vol. 10, No. 4, April pp. 29-34ArkansasMid-continent, Geophysics -seismics
DS1960-0929
1968
Brown, R.P.Brown, R.P.A Structural and Petrological Study of the Kimberlite Dike Swarm at Ithaca New York.Bsc. Thesis, Cornell University, 115P.United States, Appalachia, New YorkStructure, Petrology
DS2002-1435
2002
Brown, R.P.C.Scott, M., Dimitrakapoulos, R., Brown, R.P.C.Valuing regional geoscientific dat a acquisition programmes: addressing issues of quantification, riskNatural Resources Forum, Vol.26,1,pp. 55-68.GlobalSustainability - uncertainty, risk, economics
DS1860-0408
1883
Brown, R.T.Brown, R.T.Geology of Morgan County, Indianapolis, IndianaIndiana Department Geol. Nat. Hist. 13th. Annual Report, PT. 1, PP. 71-85.United States, IndianaDiamonds Occurrence
DS1975-0168
1975
Brown, R.W.Reid, A.M., Donaldson, C., Dawson, J.B., Brown, R.W.The Igwisi Hills Extrusive KimberlitePhysics and Chemistry of the Earth., Vol. 9, PP. 199-218.Tanzania, East AfricaGeology
DS1975-0169
1975
Brown, R.W.Reid, A.M., Donaldson, C.H., Brown, R.W., Ridley, R.I., Dawson.Mineral Chemistry of Peridotite Xenoliths from the Lashainevolcano, Tanzania.Physics and Chemistry of the Earth., Vol. 9, PP. 525-544.Tanzania, East AfricaMineral Chemistry
DS1975-0391
1976
Brown, R.W.Reid, A.M., Brown, R.W., Dawson, J.B., Whitfield, G.G., Siebert.Garnet and Pyroxene Composition in Some Diamondiferous Eclogites.Contributions to Mineralogy and Petrology, Vol. 58, PP. 203-220.Tanzania, East AfricaPetrography, Mineral Chemistry
DS1989-0185
1989
Brown, R.W.Brown, R.W., Allsopp, H.L., Bristow, J.W., Smith, C.B.Improved precision of rubidium-strontium (Rb-Sr) dating of kimberliticmicas: an assessment ofa leaching techniqueChemical Geology, Vol. 79, pp. 125-136South AfricaMakganyene Kimberlite, Geochronology
DS1998-0172
1998
Brown, R.W.Brown, R.W., Gallagher, Griffin, Ryan, De Wit, BeltonKimberlites, accelerated erosion and evolution of the lithospheric mantle beneath Kaapvaal - mid-Cretaceous..7th International Kimberlite Conference Abstract, pp. 105-107.South AfricaHeat flow data, uplift, Kaapvaal Craton
DS2002-0579
2002
Brown, R.W.Gleadow, A.J., Kohn, B.P., Brown, R.W., O'Sullivan, P.B., Raza, A.Fission track thermotectonic imaging of the Australian continentTectonophysics, Vol. 349, No. 1-4, pp. 5-21.AustraliaGeothermometry
DS2002-0870
2002
Brown, R.W.Kohn, B.P., Gleadow, A.J.W., Brown, R.W., Gallagher, K., O'Sullivan, P.B.Shaping the Australian crust over the last 300 million years: insights from fission trackAustralian Journal of Earth Sciences, Vol. 49,4,August pp. 697-718.AustraliaTectonics, Geothermometry
DS2002-1294
2002
Brown, R.W.Raab, M.J., Brown, R.W., Gallagherm K., Carter, A., Weber, K.Late Cretaceous reactivation of major crustal shear zones in northern Namibia: constraints from apatite fission track analysis.Tectonophysics, Vol. 349, No. 1-4, pp.75-92.NamibiaGeochronology, Tectonics
DS2000-0533
2000
Brown, S.J.A.Krapez, B., Brown, S.J.A., Hand, J., Barley, M., Cas, R.Age constraints on recycled crustal and supracrustal sources of Archean metasedimentary sequences.Tectonophysics, Vol. 322, No. 1-2, pp.89-133.Australia, Eastern GoldfieldsGeochronology, Subduction
DS201907-1523
2019
Brown, S.R.Andrews, G.D.M., Russell, J.K., Cole, B.G.., Brown, S.R.The kimberlite factory: the volcanic nature of kimberlites.Joint 53rd Annual South-Central/53rd North Central/71st Rocky Mtn GSA section Meeting, 1p. AbstractMantlediamond genesis

Abstract: Although traditionally considered the realm of igneous petrologists and geochemists, kimberlites have received attention from physical volcanologists interested in how they are emplaced in the crust and how they can erupt. This presentation will review the evidence for the volcaniclastic (i.e. fragmental) nature of kimberlites from examples in Canada's Northwest Territories and in Pennsylvania. A growing body of evidence indicates that kimberlite magmas are gas-dominated (overwhelmingly CO2) suspensions of molten kimberlite liquid and crystals, usually olivines. The olivines, like other mineral phases and xenoliths, are entrained from the surrounding mantle peridotite wall-rock, rather than crystallized from the meager kimberlite liquid, and are, therefore, overwhelmingly xenocrystic. This crystal and rock fragment load is sampled and mechanically processed by a turbulent gas-jet before being immersed in a bath of kimberlite liquid: this is the kimberlite factory. As the gas-charged crack-tip propagates and ascends, new mantle is processed into the kimberlite factory. Each emplacement event records the passage of a kimberlite factory through the mantle and lithosphere. The Masontown kimberlite in Pennsylvania is a solitary hypabyssal kimberlite dyke but it preserves evidence of the passage of a single kimberlite factory. Although many kimberlites stall in the crust, many erupt explosively to produce indisputably volcaniclastic kimberlite lithofacies associated with diatremes. Open-pit mining of several diatremes in Canada reveals the complex temporal-spatial nature of different emplacement events within the same volcanic field, and the ubiquitous presence of hypabyssal kimberlite dykes that fed or attempted to feed explosive eruptions. Such explosive eruptions sustained tephra plumes that produced kimberlite fall deposits and pyroclastic density currents that produced kimberlite ignimbrites; both of which exited their source diatremes and inundated the surrounding landscape.
DS201907-1535
2019
Brown, S.R.Cole, B.G., Andrews, G.D.M., Brown, S.R., Prellwitz, H.The Masontown kimberlite, Fayette County, Pennsylvania: insights into emplacement processes by the characterization of xenocryst sizes and shapes using computed tomography.Joint 53rd Annual South-Central/53rd North Central/71st Rocky Mtn GSA section Meeting, Vol. 331 United States, Pennsylvaniadeposit - Masontown

Abstract: The late Jurassic Masontown dyke in Fayette County, SW Pennsylvania, preserves abundant rounded, mm to cm-diameter masses of olivine and serpentine cemented together in serpentine-rich kimberlite groundmass. Each mass is interpreted to be a partially serpentinized olivine xenocryst or peridotite xenocryst. Each rounded clast is jacketed by a distinct rim of serpentine; probably originally olivine. The (1) ubiquitous roundness of clasts and (2) the presence of distinct serpentine jackets around each clast, supports emplacement of the dyke by a 'kimberlite factory' (Brett et al., 2015). Due to the paucity of available samples, we have used non-destructive imaging by computed tomography (CT) at the National Energy Technology Lab in Morgantown, WV, to construct 3D models of the internal structure of hand samples loaned from the Smithsonian Institute's Museum of Natural History. MicroCT (1-3 micron resolution) and industrial CT (~15 microns resolution) serial scans processed in ImageJ and Blob3D allow for 3D characterizations of individual clasts, including their shape factors (sphericity, roughness, etc.) and sizes (i.e. crystal size distributions).
DS1990-1239
1990
Brown, T.Rock, N., Brown, T., Hattie, J.Geological statistics on the Apple Macintosh. Overview and brief assessment of programs availableTerra Nova, Vol. 2, No. 1, pp. 93-100GlobalComputers, Macintosh programs
DS200512-0379
2005
Brown, T.A.Guilderson, T.P., Reimer, P.J., Brown, T.A.The boon and the bane of radiocarbon dating.Science, Vol. 307, 5708, Jan. 21, pp. 362-3.Radiocarbon technology - not specific to diamonds
DS202108-1309
2021
Brown, T.J.Shaikh, A.M., Tappe, S., Bussweiler, Y., Brown, T.J., Vollmer, C.Origins of olivine in Earth;s youngest kimberlite: Igwisi Hills volcanoes, Tanzanian craton.Contributions to Mineralogy and Petrology, 10.1007/s00410-021-01816-2 Africa, Tanzaniadeposit - Igwisi Hills
DS200712-0052
2007
Brown, V.M.Baranoski, M.T., Brown, V.M., Watts, D.Deep gas well encounters ultramafic kimberlite like material in the Sauk Sequence north eastern Ohio, USA. 1720 m deep .... 20 m zone.Geosphere, Vol. 3, no. 3, pp. 177-183.United States, OhioUltramafics
DS1989-1146
1989
Brown, W.L.Ohnenstetter, D.R., Brown, W.L.Disequilibrium crystallization in a bonninite from New CaledoniaGeological Association of Canada (GAC) Annual Meeting Program Abstracts, Vol. 14, p. A22. (abstract.)New CaledoniaBonninite
DS1992-1134
1992
Brown, W.L.Ohnenstetter, D., Brown, W.L.Overgrowth textures, disequilibrium zoning and cooling history of a glassy four pyroxene boninite dyke from New CaledoniaJournal of Petrology, Vol. 33, No. 1, February pp. 231-?New CaledoniaBoninite, Petrology
DS1999-0726
1999
Brown., L.Tandon, K., Brown., L., Hearn, T.Deep structure of the northern Rio Grande rift beneath the San Luis basin (Colorado) from a seismic surveyTectonophysics, Vol. 302, No. 1-2, Feb. 15, pp. 41-56.ColoradoTectonics, rift evolution
DS201601-0008
2015
Browne, J.Browne, J.Seven elements that have changed the world. Carbon, silicon, titanium, iron, silver, gold, uraniumWeidenfeld & Nicholson London Book Publisher, Amazon.com approx. 12.00 paperbackTechnologyBook

Abstract: Humans have put the Earth’s resources to extraordinary use. Carbon provides us with heat, light and mobility at the flick of a switch. From silver came photography, the preservation of memories, and a task which for centuries was confined to painters, sketchers and our imaginations. Silver in turn was eventually replaced by silicon, an element which enables us to communicate and transmit information across the globe in an instant. But our use of the Earth’s resources is not always for the benefit of humankind. Our relationship with the elements is one of great ambivalence. Uranium produces both productive nuclear power and destructive atomic bombs; iron is the bloody weapon of war, but also the economic tool of peace; our desire for alluring gold is the foundation of global trade, but has also led to the death of millions. This book vividly describes how seven key elements have shaped the world around us - for good and for bad. Seven Elements takes you on an adventure of human passion, ingenuity and discovery. This journey is far from over: we continue to find surprising new uses for these seven elements. Discover how titanium pervades modern consumer society; how natural gas is transforming the global energy sector; and how an innovative new form of carbon could be starting a technological revolution. Seven Elements is a unique mix of science, history and politics, interwoven with the author’s extensive personal and professional experience.
DS2001-0138
2001
Browne, S.K.G.Browne, S.K.G.Commodity forecasting in the valuation of mining projectsValmin 01, Mineral Asset Valuation Oct. 25-6th., pp.190-4.AustraliaEconomics - aluminum, copper, Mineral reserves, resources, valuation, exploration
DS1930-0133
1933
Browne, W.R.Browne, W.R.An Account of Post-paleozoic Igneous Activity in New South WalesRoyal Society. NEW SOUTH WALES Transactions, Vol. 67, No. 1, PP. 73-81.Australia, New South WalesKimberlite
DS1975-0678
1978
Brownfield, I.K.Armbrustmacher, T.J., Brownfield, I.K.Carbonatites in the Wet Mountains Area, Custer and Fremont Counties, colorado.United States Geological Survey (USGS) OPEN FILE., No. 78-177, 5P.United States, Colorado, Rocky MountainsBlank
DS1993-1477
1993
Brownfield, I.K.Skipp, G.L., Brownfield, I.K.Improved density gradient seperation techniques using sodium polytung state and a comparison to the use of other heavy liquidsUnited States Geological Survey (USGS) Open File, No. 92-0386, 16p. $ 3.00GlobalGeochemistry, Analysis -techniques
DS1960-0930
1968
Brownfield, J.Brownfield, J.The Peridotite Dike of Fayette and Greene CountiesWest Virginia Academy of Science Proceedings, Vol. 40, PP. 235-236.Appalachia, PennsylvaniaRelated Rocks, Geology
DS1994-0401
1994
BrowningDawson, J.B., Pinkerton, H., Norton, G.E., Pyle, BrowningPetrology and geochemistry of Oldoinyo Lengai lavas extruded in Nov. @magma source, ascent and cryst.Carbonatite volcanism, Ed. Bell, K., Keller, J., pp. 47-69.TanzaniaPetrology - Carbonatite volcanism., Deposit -Oldoinyo Lengai
DS201112-0100
2011
Browning, J.V.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
DS1991-1687
1991
Browning, P.Tainton, K.M., Browning, P.The Group 2 kimberlite -lamproite connection: some constraints from the Barkly-west district, northern Cape Province, South AfricaProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 405-407South AfricaMicaceous kimberlites, Sover-Doornkloof, Sover-North, geochronology
DS1992-0176
1992
Browning, P.Browning, P.Petrological Programs for the Mineralogical Association of Canada (MAC) 1Terra Nova, Vol. 4, No. 4, Geo Logic section, pp. 413-416GlobalComputer, Programs -Petrology for Mineralogical Association of Canada (MAC) 1
DS1992-1164
1992
Browning, P.Parson, L.M., Murton, B.J., Browning, P.Ophiolites and their modern oceanic analoguesGeological Society of London, Publishing No. 60, approx. $ 100.00GlobalBook -ad, Ophiolites and modern analogues
DS200612-0185
2006
Broz, M.E.Broz, M.E., Cook, R.F., Whitney, D.L.Microhardness, toughness and modulous of Mohs scale minerals.American Mineralogist, Vol. 91, pp. 135-142.TechnologyDepth sensing indentation, mechanical propreties nano
DS1998-1551
1998
Brozena, J.Vogt, P.R., Jung, W., Brozena, J.Arctic margin gravity highs remain puzzlingEos, Vol. 79, No. 49, Dec. 8, pp. 601, 605, 6.Northwest Territories, ArcticGeophysics - gravity, Oceanic crust
DS200512-0434
2005
Brozena, J.Hinze, W.J., Aiken, C., Brozena, J., Coakley, Dater, Flanagan, Forsberg, Hildenbrand, Keller, KelloggNew standards for reducing gravity data: the North American gravity database.Geophysics, Vol. 70, 4, pp. J25-J32.Canada, United StatesGeophysics - gravity
DS1999-0056
1999
Brozenam J.M.Bell, R.E., Childers, V.A., Brozenam J.M.Airborne gravity and precise positioning for geologic applicationsJournal of Geophysical Research, Vol. 104, No. 7, July 10, pp. 15281-92.GlobalGeophysics - gravity, GPS
DS201607-1311
2016
Brroker, R.A.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.
DS201112-0565
2011
Brtnicky, M.Kynicky, J., Cheng, Xu., Chakhmouradian, A.R., Reguir, E., Cihlarova, H., Brtnicky, M.REE mineralization of high grade REE-Ba-Sr and REE-Mo deposits in Mongolia and China.Goldschmidt Conference 2011, abstract p.1260.China, MongoliaCarbonatite
DS201805-0977
2018
Brtnicky, M.Smith, M., Kynicky, J., Xu, C., Song, W., Spratt, J., Jeffries, T., Brtnicky, M., Kopriva, A., Cangelosi, D.The origin of secondary heavy rare earth element enrichment in carbonatites: constraints from the evolution of the Huanglongpu district, China.Lithos, Vol. 308-309, pp. 65-82.Chinacarbonatite

Abstract: The silico?carbonatite dykes of the Huanglongpu area, Lesser Qinling, China, are unusual in that they are quartz-bearing, Mo-mineralised and enriched in the heavy rare earth elements (HREE) relative to typical carbonatites. The textures of REE minerals indicate crystallisation of monazite-(Ce), bastnäsite-(Ce), parisite-(Ce) and aeschynite-(Ce) as magmatic phases. Burbankite was also potentially an early crystallising phase. Monazite-(Ce) was subsequently altered to produce a second generation of apatite, which was in turn replaced and overgrown by britholite-(Ce), accompanied by the formation of allanite-(Ce). Bastnäsite and parisite where replaced by synchysite-(Ce) and röntgenite-(Ce). Aeschynite-(Ce) was altered to uranopyrochlore and then pyrochlore with uraninite inclusions. The mineralogical evolution reflects the evolution from magmatic carbonatite, to more silica-rich conditions during early hydrothermal processes, to fully hydrothermal conditions accompanied by the formation of sulphate minerals. Each alteration stage resulted in the preferential leaching of the LREE and enrichment in the HREE. Mass balance considerations indicate hydrothermal fluids must have contributed HREE to the mineralisation. The evolution of the fluorcarbonate mineral assemblage requires an increase in aCa2+ and aCO32? in the metasomatic fluid (where a is activity), and breakdown of HREE-enriched calcite may have been the HREE source. Leaching in the presence of strong, LREE-selective ligands (Cl?) may account for the depletion in late stage minerals in the LREE, but cannot account for subsequent preferential HREE addition. Fluid inclusion data indicate the presence of sulphate-rich brines during alteration, and hence sulphate complexation may have been important for preferential HREE transport. Alongside HREE-enriched magmatic sources, and enrichment during magmatic processes, late stage alteration with non-LREE-selective ligands may be critical in forming HREE-enriched carbonatites.
DS201906-1308
2019
Brtnicky, M.Kynicky, J., Smith, M.P., Song, W., Fryzova, R., Brtnicky, M.The role of carbonate-flouride melt immiscibility in shallow REE deposits evolution: new evidence from Mongolia.3rd International Critical Metals Meeting held Edinburgh, 1p. abstract p. 52.Asia, MongoliaREE
DS202003-0337
2020
Brtnicky, M.Feng, M., Song, W., Kynicky, J., Smith, M., Cox, C., Kotlanova, M., Brtnicky, M., Fu, W., Wei, C.Primary rare earth element enrichment in carbonatites: evidence from melt inclusions in Ulgii Khild carbonatite, Mongolia.Ore Geology Reviews, Vol. 117, 14p. PdfAsia, Mongoliadeposit - Ulgii Khild
DS201607-1301
2016
Bruand, E.Hart, E., Storey, C., Bruand, E., Schertl, H-P., Alexander, B.D.Mineral inclusions in rutile: a novel recorder of HP-UHP.Earth and Planetary Science Letters, Vol. 446, pp. 137-148.MantleCoesite, subduction

Abstract: The ability to accurately constrain the secular record of high- and ultra-high pressure metamorphism on Earth is potentially hampered as these rocks are metastable and prone to retrogression, particularly during exhumation. Rutile is among the most widespread and best preserved minerals in high- and ultra-high pressure rocks and a hitherto untested approach is to use mineral inclusions within rutile to record such conditions. In this study, rutiles from three different high- and ultrahigh-pressure massifs have been investigated for inclusions. Rutile is shown to contain inclusions of high-pressure minerals such as omphacite, garnet and high silica phengite, as well as diagnostic ultrahigh-pressure minerals, including the first reported occurrence of exceptionally preserved monomineralic coesite in rutile from the Dora -Maira massif. Chemical comparison of inclusion and matrix phases show that inclusions generally represent peak metamorphic assemblages; although rare prograde phases such as titanite, omphacite and corundum have also been identified implying that rutile grows continuously during prograde burial and traps mineralogic evidence of this evolution. Pressure estimates obtained from mineral inclusions, when used in conjunction with Zr-in-rutile thermometry, can provide additional constraints on the metamorphic conditions of the host rock. This study demonstrates that rutile is an excellent repository for high- and ultra-high pressure minerals and that the study of mineral inclusions in rutile may profoundly change the way we investigate and recover evidence of such events in both detrital populations and partially retrogressed samples.
DS1991-0187
1991
Bruce, A.Bruce, A.Petrology of a dynamic earth's mantle #1Eclogae Geologicae Helvetiae, Vol. 84, No. 2, pp. 288-296GlobalMantle, Petrology -experimental
DS1994-0220
1994
Bruce, C.Bruce, C.Bolivia -its potential and recent activityMining in Latin America, Institute of Mining and Metallurgy (IMM)., pp. 17-24BoliviaEconomics, Mining
DS1975-0892
1978
Bruce, G.S.W.Watson, K.D., Bruce, G.S.W., Halladay, L.B.Kimberlitic Dyke in Keith Township, OntarioCanadian Mineralogist., Vol. 16, PP. 97-102.Canada, OntarioPetrography, Genesis, Texture, Microprobe, Analyses, Ilmenite
DS201112-0537
2011
Bruce, L.Kopylova, M.G., Afansiev, V.P., Bruce, L., Ryder, J.Diamondiferous conglomerate preserves evidence for kimberlite and the deep cratonic root of the Mesoarchean southern Superior Craton.Goldschmidt Conference 2011, abstract p.1221.Canada, OntarioWawa
DS201212-0371
2012
Bruce, L.Kopylova, M.G., Miller, C., Afanasiev, V.P., Bruce, L., Thurston, P., Ryder, J.Kimberlite derived harzburgitic diamonds from a >2.7 GA southern Superior Province, Protocraton.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractCanada, Ontario, WawaDiamond morphology
DS200912-0078
2009
Bruce, L.F.Bruce, L.F., Kopylova, M.G., Longo, M., Ryder, J., Dobrzhinetskaya, L.F.Cathodluminescence of diamonds in metamorphic rocks.37th. Annual Yellowknife Geoscience Forum, Abstracts p. 4-5.TechnologyCL
DS201112-0121
2011
Bruce, L.F.Bruce, L.F., Kopylova, M.G., Longo, M., Ryder, J., Dobrzhinetskaya, L.F.Luminescence of diamonds from metamorphic rocks.American Mineralogist, Vol. 96, 1, pp. 14-22.Canada, Ontario, Wawa, Russia, GermanyUHP, cathodluminescence
DS201112-0536
2011
Bruce, L.F.Kopylova, M.G., Afanasiev, V.P., Bruce, L.F., Thurston, P.C., Tyder, J.Metaconglomerate preserves evidence for kimberlite Diamondiferous root and medium grade terrane of a pre-2.7 Ga Southern Superior protocraton.Earth and Planetary Science Letters, Vol. 312, 1-2, Dec. 1, pp. 213-235.Canada, OntarioMetaconglomerates
DS201112-0538
2011
Bruce, L.F.Kopylova, M.G., Afansiev, V.P., Bruce, L.F., Ryder, J.Diamond exploration in orogenic settings: lessons from Wawa metaconglomerate.Yellowknife Geoscience Forum Abstracts for 2011, abstract p. 52-53.Canada, Ontario, WawaHeavy minerals
DS2002-0802
2002
Bruce, M.C.Kamber, B.S., Ewart, A., Collerson, K.D., Bruce, M.C., McDonald, G.D.Fluid mobile trace element constraints on the role of slab melting and implications for Archean crustal growth models.Contributions to Mineralogy and Petrology, Vol. 144, 1, Oct. pp. 38-56.CrustSubduction, Tectonics
DS1989-0186
1989
Bruce, P.M.Bruce, P.M., Huppert, H.E.Thermal control of basaltic fissure eruptionsNature, Vol. 342, December 7, pp. 665-667GlobalBasalt, Magma -dykes
DS2001-0183
2001
Brudainzki, M.R.Chen, W.P., Brudainzki, M.R.Evidence for a large scale remnant of subducted lithosphere beneath FijiScience, No. 5526, June 29, pp. 2475-8.FijiSubduction - not specific to diamonds
DS201201-0836
2012
Brudzinski, M.Chen, W-P., Hung, S-H., Tseng, T-L., Brudzinski, M., Yang, Z., Nowack, R.L.Rheology of the continental lithosphere: progress and new perspectives.Gondwana Research, Vol. 21, 1, pp. 4-18.MantleGeodynamics
DS1975-0472
1977
Brueckner, H.K.Brueckner, H.K.A Crustal Origin for Eclogites and a Mantle Origin for Garnet Peridotites: Strontium Isotopic Evidence from Clinopyroxenes.Contributions to Mineralogy and Petrology, Vol. 60, PP. 1-15.Norway, ScandinaviaPetrogenesis, Isotope
DS1980-0077
1980
Brueckner, H.K.Brueckner, H.K., Rex, D.C.Potassium-argon and Rubidium-strontium Geochronology and Strontium isotopic Study of the Alno Alkaline Complex Northeastern Sweden.Lithos, Vol. 13, No. 2, PP. 111-119.Sweden, ScandinaviaIsotope
DS1998-0173
1998
Brueckner, H.K.Brueckner, H.K.Sinking intrusion model for the emplacement of garnet bearing peridotites into continent collision orogens #1Geology, Vol. 26, No. 7, July pp. 631-34.Norway, Western Gneiss areaGarnet peridotites, Intrusion model
DS1998-0174
1998
Brueckner, H.K.Brueckner, H.K., Gilotti, J.A., Nutman, A.Caledonian eclogite- facies metamorphism of Early Proterozoic protoliths from northeast Greenland eclogite...Contributions to Mineralogy and Petrology, Vol. 130, No. 2, pp. 103-120.GreenlandEclogite province, Regional geology
DS2002-0215
2002
Brueckner, H.K.Brueckner, H.K., Carswell, D.A., Griffin, W.L.Paleozoic diamonds with a Precambrian peridotite lens in UHP gneisses of the Norwegian Caledonides.Earth and Planetary Science Letters, Vol. 203, 3-4, pp. 805-16.Scandinavia, NorwayUHP - peridotites
DS2003-0220
2003
Brueckner, H.K.Carswell, D.A., Brueckner, H.K., Cuthbert, S.J., Mehta, K., O'Brien, P.J.The timing of stabilization and the exhumation rate for ultra high pressure rocks in theJournal of Metamorphic Geology, Vol. 21, 6, pp. 601-612.NorwayUHP
DS200412-0145
2004
Brueckner, H.K.Beyer, E.E., Brueckner, H.K., Griffin, W.L.,O'Reilly, S.Y., Graham, S.Archean mantle fragments in Proterozoic crust, Western Gneiss region, Norway.Geology, Vol. 32, 7, July pp. 609-612.Europe, NorwayGarnet peridotites
DS200412-0228
2004
Brueckner, H.K.Brueckner, H.K., Van Roermund, H.L.M.Dunk tectonics: a multiple subduction/education model for the evolution of the Scandinavian Caledonides.Tectonics, Vol. 23, 2, 10.1029/2003TC001502Europe, ScandinaviaSubduction
DS200412-0286
2003
Brueckner, H.K.Carswell, D.A., Brueckner, H.K., Cuthbert, S.J., Mehta, K., O'Brien, P.J.The timing of stabilization and the exhumation rate for ultra high pressure rocks in the Western Gneiss region of Norway.Journal of Metamorphic Geology, Vol. 21, 6, pp. 601-612.Europe, NorwayUHP
DS200412-0666
2004
Brueckner, H.K.Gilotti, J.A., Nutman, A.P., Brueckner, H.K.Devonian to Carboniferous in the Greenland Caledonides: U Pb zircon and Sm Nd ages of high pressure and ultrahigh pressure metamContributions to Mineralogy and Petrology, Vol. 148, 2, pp. 215-235.Europe, GreenlandUHP, geochronology
DS200612-0186
2006
Brueckner, H.K.Brueckner, H.K.Dunk, dunkless and re-dunk tectonics: a model for metamorphism, lack of metamorphism and repeated metamorphism of HP/UHP terranes.International Geology Review, Vol. 48, 11, pp. 978-995.MantleTectonics
DS200812-0289
2008
Brueckner, H.K.Dobrzhinetskaya, L.F., Brueckner, H.K., Cuthbert, S.I.Ultrahigh pressure metamorphism: from Earth's interior to mountain buildings.Lithos, In press available 20p.MantleUHP
DS200912-0721
2009
Brueckner, H.K.Spengler, D., Brueckner, H.K., Herman, L.M., Van Roermund, Drury, MasonLong lived, cold burial of Baltica to 200 km depth.Earth and Planetary Science Letters, Vol. 281, 1-2, April 30, pp. 27-35.Europe, Baltic ShieldSubduction
DS201212-0068
2012
Brueckner, H.K.Beyer, E.E., Brueckner, H.K., Griffin, W.L., O'Reilly, S.Y.Laurentian provenance of Archean mantle fragments in the Proterozoic Baltic crust of the Norwegian Caledonides.Journal of Petrology, Vol. 53, 7, pp. 1357-1383.Europe, NorwayGeochronology
DS1950-0095
1952
Bruet, E.Bruet, E.Le Diamant (1952)Paris: Payot., 256P.South Africa, Arizona, French Equatorial Africa, Rocky MountainsKimberlite, Kimberley, History, Crystallography, Canyon Diablo
DS201603-0367
2015
Bruffaerts, L.Bruffaerts, L.A diamantaire struggle: redefining conflict diamonds in the Kimberley Process.International Affairs, Vol. 91, 5, pp. 1085-1101.GlobalKP

Abstract: Diamonds are forever. But what of the definition of conflict diamonds used by the Kimberley Process (KP)? Despite the fact that civil society has raised attention to the cloudy issue of state-perpetrated diamond-related human rights abuses throughout the past decade, the continued longevity of the central definition around which the Kimberley Process revolves still appears to be a crystal-clear fact. As it turns out, calls to broaden the scope of the conflict diamond definition have not been successful because several discourse manipulations within the KP have had formative effects on other actors’ identities and interests. Discourse spacing-the strategic allocation of ‘appropriate’ spaces for certain discourses within a particular institutionalized setting-has been strategically employed in an attempt to place boundaries on the redefinition discourse. By claiming that addressing human rights abuses lies beyond the mandate of the KP, several KP participant states have sought to convince others that discussing redefinition has no place on the KP reform agenda. Discourse timing has also been key, where numerous African states’ perceptions of redefinition were influenced by accusations of neo-colonial intent on the part of western KP participant states that stemmed from a sanctions debate that was taking place parallel to the redefinition debate. The article finds that these two occurrences, alongside the KP’s consensus based decision-making structure and several KP participant states’ fears about setting a human rights precedent, have obstructed the road to the redefinition of conflict diamonds.
DS2003-0933
2003
Brugmann, G.Meisel, T., Reisberg, L., Moser, J., Carignan, J., Melcher, F., Brugmann, G.Re Os systematics of UB N, a serpentinized peridotite reference materialChemical Geology, Vol. 201, 3-4, Nov. 14, pp.161-179.FranceGeochronology, metamorphosed lherzolite
DS200412-1293
2003
Brugmann, G.Meisel, T., Reisberg, L., Moser, J., Carignan, J., Melcher, F., Brugmann, G.Re Os systematics of UB N, a serpentinized peridotite reference material.Chemical Geology, Vol. 201, 3-4, Nov. 14, pp.161-179.Europe, FranceGeochronology, metamorphosed lherzolite
DS200612-0624
2005
Brugmann, G.Ionov, D.A., Shirey, S.B., Weis, D., Brugmann, G.Os Hf Nd isotope and PGE systematics of spinel peridotite xenoliths from Tok, SE Siberian craton: effects of pervasive metasomatism in shallow refractorEarth and Planetary Science Letters, Vol. 241, 1-2, pp. 47-64.Russia, SiberiaMetasomatism, xenoliths, Tokinsky
DS200612-1068
2006
Brugmann, G.Peltonen, P., Brugmann, G.Origin of layered continental mantle ( Karelian craton, Finland): geochemical and Re-Os isotope constraints.Lithos, Vol. 89, 3-4, July pp. 405-423.Europe, Finland, FennoscandiaMetasomatism, geochronology, peridotite
DS200812-0985
2008
Brugmann, G.Ryabchikov, L.D., Kogarko, L.N., Brugmann, G.Mantle sources of highly reduced melts in peridotites from Sal Island, cape Verde Archipelago.Deep Seated Magmatism, its sources and plumes, Ed. Vladykin, N.V., 2008 pp. 25-31.Europe, Cape Verde IslandsPeridotite
DS200812-1091
2008
Brugmann, G.Sobolev, A.V., Hofmann, A.W., Brugmann, G., Batanova, V.G., Kuzmin, D.V.A quantitative link between recycling and osmium isotopes.Science, Vol. 321, 5888, July 25, p. 536.MantleSubduction
DS200912-0669
2008
Brugmann, G.Savelieva, G.N., Sobolev, A.V., Batanova, V.G., Suslov, P.V., Brugmann, G.Structure of melt flow channels in the mantle.Geotectonics, Vol. 42, 6, pp. 430-447.MantleMelting
DS1995-1562
1995
Brugmann, G.E.Reischmann, T., Brugmann, G.E., Jochum, K.P., Todt, W.A.Trace element and isotopic composition of baddeleyiteMineralogy and Petrology, Vol. 53, No. 1-3, pp. 155-164.GlobalMineralogy, Baddeleyite
DS1999-0571
1999
Brugmann, G.E.Puchtel, I.S., Brugmann, G.E., Hofmann, A.W.Precise Re Os mineral isochron and lead neodymium Os isotope systematics of a mafic ultramafic sill in 2.0 Ga OnegaEarth and Planetary Science Letters, Vol. 170, No. 4, July 30, pp. 447-62.Baltic shieldGeochronology, Onega plateau
DS1999-0572
1999
Brugmann, G.E.Puchtel, I.S., Brugmann, G.E., Hofmann, A.W.Precise Re Os mineral isochron and lead neodymium Os isotope systematics of mafic ultramafic sill in 2.0 Ga OnegaEarth and Planetary Science Letters, Vol. 170, No. 4, July 30, pp. 447-62.Baltic ShieldGeochronology, Onega Plateau
DS2001-0952
2001
Brugmann, G.E.Puchtel, I.S., Brugmann, G.E., Hofman, A.W.1870's enriched domain in an Archean mantle plume: evidence from 2.8 Ga komatiites of the Kostomuksha GSEarth and Planetary Science Letters, Vol. 186, No. 3-4, Apr. 15, pp. 513-26.Baltic ShieldPlume - geochronology - not specific to diamonds
DS2001-0953
2001
Brugmann, G.E.Puchtel, I.S., Brugmann, G.E., Kulikova, V.V.Os isotope systematics of komatiitic basalts from the Vetreny belt, BalticShield: evidence for chondritic..Contributions to Mineralogy and Petrology, Vol. 140, No. 5, pp. 588-606.Baltic ShieldGeochronology, Hot spot - plume 2.45 Ga
DS1996-0157
1996
Bruguier, O.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
DS200812-1183
2008
Bruguier, O.Trap, P., Faure, P., Lin, M., Bruguier, O., Monie, P.Contrasted tectonic styles for the Paleoproterozoic evolution of the North Chin a Craton: evidence for a 2.1 Ga thermal and tectonic event in the Fuping Massif.Journal of Structural Geology, Vol. 30, 9, pp. 1109-1125.ChinaCraton, not specific to diamonds
DS201212-0485
2012
Bruguier, O.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
Bruguier, O.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
DS201412-0088
2014
Bruguier, O.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
DS201709-1965
2017
Bruguier, O.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.
DS1987-0080
1987
Bruha, D.J.Bruha, D.J., Johnson, E.L.The extraterrestrial origin of kimberlites and their role in stopping lithospheric subductionTectonika Anathemata, Vol. 4, No. 4, 2pGlobalKimberlite, Genesis
DS1995-0793
1995
Bruhn, R.Hickman, S., Sibson, R., Bruhn, R.Introduction to special section: mechanical involvement of fluids infaultingJournal of Geophysical Research, Vol. 100, No.B7, July 10, pp. 12, 831-840GlobalStructure, Fluids -faulting
DS1989-0517
1989
Bruhnke, S.G.Glass, G.B., Bruhnke, S.G.Brief notation : field and laboratory investigations of potentially Diamond bearing kimberlites and other rocks.. ongoing -more than 100 possible pipesrecognizGeological Survey of Wyoming, 56th. Annual Report, Notation as title -full, p. 11. Brief as above in titleWyomingNews item, Diamond research
DS1986-0862
1986
Bruland, K.W.Williams, R.W., Gill, J.B., Bruland, K.W.Ra Th disequilibration temperatures systematics-timescale of carbonatite magma formation at Oldoiny Lengai volcano, TanzaniaGeochimica et Cosmochimica Acta, Vol. 50, No. 6, June pp. 1249-1259TanzaniaCarbonatite
DS1989-0187
1989
Bruley, J.Bruley, J., Brown, L.M.Quantitative electron energy loss spectroscopy microanalysis of platelet and voidite defects in natural diamondPhilosph. Mag.Lett., , A., Vol. 59, No. 2, pp. 247-261GlobalDiamond, Natural diamond -voidites
DS1992-0177
1992
Bruley, J.Bruley, J.Detection of nitrogen at 100 platelets in a type 1AA/B diamondPhilosophical Magazine Letters, Vol. 66, No. 1, July pp. 47-56GlobalDiamond morphology, Nitrogen
DS201806-1235
2018
Brum da Silveira, A.Marti, J., Groppelli, G., Brum da Silveira, A.Volcanic stratigraphy: a review.Journal of Volcanology and Geothermal Research, Vol. 357, pp. 68-91.Mantlevolcanism

Abstract: Volcanic stratigraphy is a fundamental component of geological mapping in volcanic areas as it yields the basic criteria and essential data for identifying the spatial and temporal relationships between volcanic products and intra/inter-eruptive processes (earth-surface, tectonic and climatic), which in turn provides greater understanding of the geological evolution of a region. Establishing precise stratigraphic relationships in volcanic successions is not only essential for understanding the past behaviour of volcanoes and for predicting how they might behave in the future, but is also critical for establishing guidelines for exploring economic and energy resources associated with volcanic systems or for reconstructing the evolution of sedimentary basins in which volcanism has played a significant role. Like classical stratigraphy, volcanic stratigraphy should also be defined using a systematic methodology that can provide an organised and comprehensive description of the temporal and spatial evolution of volcanic terrain. This review explores different methods employed in studies of volcanic stratigraphy, examines four case studies that use differing stratigraphic approaches, and recommends methods for using systematic volcanic stratigraphy based on the application of the concepts of traditional stratigraphy but adapted to the needs of volcanological environment.
DS201012-0519
2009
Brum da Silviera, A.Mourai, C., Mata, J., Doucelance, R., Madeira, J., Brum da Silviera, A., Silva, L.C., Moreira, M.Quaternary extrusive calciocarbonatite volcanism on Brava Island ( Cape Verde): a nephelinite carbonatite immiscibility product.Journal of African Earth Sciences, Vol. 56, 2-3, pp. 59-74.Europe, Cape Verde IslandsCarbonatite
DS1982-0010
1982
Brumfield, K.E.Allsopp, C.M., Brumfield, K.E., Street, R.L.The Crustal Structure Associated with the East Continental Gravity High in Central Kentucky.Geological Society of America (GSA), Vol. 14, No. 5, P. 253, (abstract.).GlobalMid-continent, Geophysics
DS1998-1620
1998
Brumm, R.Zack, T., Brumm, R.Ilmenite/liquid partition coefficients of 26 trace elements determined through ilmenite/clinopyroxene...7th International Kimberlite Conference Abstract, pp. 986-8.GlobalGarnet pyroxenites, Magmatic processes
DS2003-1380
2003
Brumm, R.Tiepolo, M., Zanetti, A., Oberti, R., Brumm, R., Foley, S., Vannucci, R.Trace element partitioning between synthetic potassic richterites and silicate melts, andEuropean Journal of Mineralogy, Vol. 15, 2, pp. 329-40.GlobalMineralogy
DS200412-1992
2003
Brumm, R.Tiepolo, M., Zanetti, A., Oberti, R., Brumm, R., Foley, S., Vannucci, R.Trace element partitioning between synthetic potassic richterites and silicate melts, and contrasts with the partitioning behaviEuropean Journal of Mineralogy, Vol. 15, 2, pp. 329-40.TechnologyMineralogy
DS1975-0706
1978
Brummer, J.J.Brummer, J.J.Diamonds in Canada, 1978The Canadian Mining and Metallurgical Bulletin (CIM Bulletin) ., Vol. 71, No. 798, PP. 64-70.Great Lakes, Canada, Ontario, Quebec, Northwest Territories, LabradorGeology, Prospecting, Locations, History
DS1975-0707
1978
Brummer, J.J.Brummer, J.J., Yuki, H.Diamond Deposits in CanadaGemmol. Soc. Japan., Vol. 5, No. 3, PP. 26-28.GlobalDiamond Occurrences
DS1984-0178
1984
Brummer, J.J.Brummer, J.J.Diamonds in Canada, 1984The Canadian Institute of Mining, Metallurgy and Petroleum (CIM), No. 29, PP. 311-320.Canada, Ontario, Quebec, Labrador, British Columbia, NorthwestBlank
DS1990-1171
1990
Brummer, J.J.Pegg, C.C., Brummer, J.J., MacDadyen, D.A.Discovery of kimberlite diatremes in the Kirkland Lake area, Ontario #1The Canadian Institute of Mining, Metallurgy and Petroleum (CIM), The Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Vol.89, No. 935, April p. 90. AbstractOntarioDiatremes -five, Diamondiferous tests
DS1991-1324
1991
Brummer, J.J.Pegg, C.C., Brummer, J.J., MacFayden, D.A.Discovery of kimberlite diatremes in the Kirkland Lake area, Ontario #2The Canadian Mining and Metallurgical Bulletin (CIM Bulletin) ., Session, Vol. 84, No. 947, March p. 99. AbstractOntarioKimberlite -diatremes, Kirkland Lake area
DS1992-0178
1992
Brummer, J.J.Brummer, J.J., MacFadyen, D.A., Pegg, C.C.Discovery of kimberlites in the Kirkland Lake area, northern Ontario, Canada. Part I: kimberlite discoveries, sampling, diamondcontent, age, emplacementThe Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Exploration Mining Geology, Vol. 1, No. 4, October pp. 351-370OntarioGeology, geophysics -aeromagnetics, Kimberlite pipes
DS1992-0179
1992
Brummer, J.J.Brummer, J.J., MacFadyen, D.A., Pegg, C.C.Discovery of kimberlites in the Kirkland Lake area, northern Ontario, Canada. Part I: early surveys and surficial geologyThe Canadian Institute of Mining, Metallurgy and Petroleum (CIM), Vol. 1, No. 4, October pp. 339-350OntarioHistory, Quaternary, sampling programs
DS2002-0224
2002
Brummer, J.J.Bumby, A.J., Eriksson, P.G., Van der Merve, R., Brummer, J.J.Shear zone controlled basins in the Blouberg area, Northern Province, syn and post tectonic sedimentation relating to 2.0 Ga reactivation of Limopo Belt.Journal of African Earth Sciences, Vol. 33, No. 3-4,pp. 445-61.South AfricaStructure, tectonics - not specific to diamonds
DS200612-0204
2006
BrunCagnard, F., Durrieu, N., Gapais, D., Brun, J-P, Ehlers, C.Crustal thickening and lateral flow during compression of hot lithospheres, with particular reference to Precambrian times.Terra Nova, Vol. 18, Feb. pp. 72-78.MantleGeothermometry
DS201312-0915
2013
BrunTirel, C., Brun, J-P, Burov, E., Wortel, M.J.R., Lebedev, S.A plate tectonics oddity: caterpillar walk exhumation of subducted continental crust.Geology, Vol. 41, 5, pp. 555-558.MantleSubduction
DS1995-1598
1995
Brun, J.P.Roman Berdiel, T., Gapais, D., Brun, J.P.Analogue models of laccolith formationJournal of Structural Geology, Vol. 17, No. 9, pp. 1337-1346GlobalMagma -intrusions, Laccoliths
DS1995-1599
1995
Brun, J.P.Roman-Berdiel, T., Gapais, D., Brun, J.P.Analogue models of laccolith formationJournal of Structural Geology, Vol. 17, No. 9, pp. 1337-1346.GlobalLaccolith, Model - not specific to kimberlites
DS1996-0183
1996
Brun, J.P.Brun, J.P., Nalpas, T.Graben invesrion in nature and experimentsTectonics, Vol. 15, No. 2, pp. 677-687.GlobalBasin, Structure - not specific to diamonds
DS200712-1012
2007
Brun, J.P.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
DS201702-0255
2016
Brun, J.P.Yamato, P., Brun, J.P.Metamorphic record of catastrophic pressure drop in subduction zones.Nature Geoscience, Vol. 10, pp. 46-50.MantleSubduction

Abstract: When deeply buried in subduction zones, rocks undergo mineral transformations that record the increase of pressure and temperature. The fact that high-pressure metamorphic parageneses are found at the Earth’s surface proves that rock burial is followed by exhumation. Here we use analysis of available data sets from high-pressure metamorphic rocks worldwide to show that the peak pressure is proportional to the subsequent decompression occurring during the initial stage of retrogression. We propose, using a simple mechanical analysis, that this linear relationship can be explained by the transition from burial-related compression to extension at the onset of exhumation. This major switch in orientation and magnitude of principal tectonic stresses leads to a catastrophic pressure drop prior to actual rock ascent. Therefore, peak pressures are not necessarily, as commonly believed, directly dependent on the maximum burial depth, but can also reflect a change of tectonic regime. Our results, which are in agreement with natural data, have significant implications for rock rheology, subduction zone seismicity, and the magnitudes of tectonic pressures sustained by rocks. Current views of subduction dynamics could be reconsidered in that perspective.
DS200612-1437
2006
Brun, J=P.Triel, C., Brun, J=P., Sokoutis, D.Extension of thickened crust and hot lithosphere: inferences from laboratory modeling.Tectonics, Vol. 25, 1, TC1005TechnologyTectonics, mantle
DS1993-0316
1993
Brun, J-P.Dauteuil, O., Brun, J-P.Oblique rifting in a slow spreading ridgeNature, Vol. 361, No. 6408, January 14, pp. 145-148GlobalTectonics, Ridge, rifting
DS200412-0780
2004
Brun, J-P.Handy, M.R., Brun, J-P.Seismicity, structure and strength of the continental lithosphere.Earth and Planetary Science Letters, Vol. 223, 3-4, July, 15, pp. 427-441.MantleRheology
DS200512-0314
2005
Brun, J-P.Gapais, D., Brun, J-P., Cobbold, P.R.Deformation mechanisms, rheology and tectonics: from minerals to the lithosphere.Geological Society of London, SP 243, 320p.MantleBook - review papers on rheology, UHP
DS200612-0205
2006
Brun, J-P.Cagnard, F., Durrieu, N., Gapais, D., Brun, J-P., Ehlers, C.Crustal thickening and lateral flow during compression of hot lithospheres, with particular reference to Precambrian times.Terra Nova, Vol. 18, 1, Feb. pp. 72-78.MantleGeophysics - seismics
DS200612-0206
2006
Brun, J-P.Cagnard, F., Durrieu, N., Gapais, D., Brun, J-P., Ehlers, C.Crustal thickening and lateral flow during compression of hot lithospheres, with particular reference to Precambrian times.Terra Nova, Vol. 18, 1, pp. 72-78.MantleMelting
DS200812-0149
2008
Brun, J-P.Brun, J-P., Facccena, C.Exhumation of high pressure rocks driven by slab rollback.Earth and Planetary Science Letters, Vol. 272, 1-2, July 30, pp. 1-7.MantleHP - slab
DS200912-0324
2009
Brun, J-P.Husson, L., Brun, J-P., Yamato, P., Faccenna, C.Episodic slab rollback fosters exhumation of HP-UHP rocks.Geophysical Journal International, Vol. 179, 3, pp. 1291-1300.MantleUHP
DS201901-0010
2018
Brun, J-P.Brun, J-P., Sokoutis, D., Tirel, C., Gueydan, F., Beslier, M-O.Crustal versus mantle core complexes.Tectonophysics, Vol. 746, pp. 22-45.Mantlegeodynamics

Abstract: Deep crustal and mantle rocks are exhumed in core complex mode of extension in three types of structures: metamorphic core complexes, oceanic core complexes and magma poor passive margins. Using available analogue and numerical models and their comparison with natural examples, the present paper reviews the mechanical processes involved in these different types of extensional setting. Three main aspects are considered: i) the primary role of lithosphere rheology, ii) the lithosphere-scale patterns of progressive deformation that lead to the exhumation of deep metamorphic or mantle rocks and iii) the initiation and development of detachment zones. Crustal core complexes develop in continental lithospheres whose Moho temperature is higher than 750 °C with “upper crust-dominated” strength profiles. Contrary to what is commonly believed, it is argued from analogue and numerical models that detachments that accommodate exhumation of core complexes do not initiate at the onset of extension but in the course of progressive extension when the exhuming ductile crust reaches the surface. In models, convex upward detachments result from a rolling hinge process. Mantle core complexes develop in either the oceanic lithosphere, at slow and ultra-slow spreading ridges, or in continental lithospheres, whose initial Moho temperature is lower than 750 °C, with “sub-Moho mantle-dominated” strength profiles. It is argued that the mechanism of mantle exhumation at passive margins is a nearly symmetrical necking process at lithosphere scale without major and permanent detachment, except if strong strain localization could occur in the lithosphere mantle. Distributed crustal extension, by upper crust faulting above a décollement along the ductile crust increases toward the rift axis up to crustal breakup. Mantle rocks exhume in the zone of crustal breakup accommodated by conjugate mantle shear zones that migrate with the rift axis, during increasing extension.
DS1960-1083
1969
Brundin, N.H.Brundin, N.H.Some Experiences in Geochemical and Heavy Mineral ProspectinCol. Sch. Mines Quarterly Bulletin., Vol. 64, PP. 89-94.GlobalGeochemistry, Heavy Mineral Concentrates, Sampling
DS1970-0484
1972
Brundin, N.H.Brundin, N.H., Nairis, B.Alterative Sample Types in Regional Geochemical ProspectingJournal of GEOCHEM. Exploration, Vol. 1, No. 1, PP. 7-46.GlobalGeochemistry, Sampling, Heavy Mineral Concentrates
DS1975-0473
1977
Brundin, N.H.Brundin, N.H., Bergstrom, J.Regional Prospecting for Ores Based on Heavy Minerals in Glacial Till.Journal of GEOCHEM. Exploration, Vol. 7, No. 1, PP. 1-19.GlobalGeochemistry, Heavy Mineral Concentrates, Sampling
DS1994-0221
1994
Brundtland, G.H.Brundtland, G.H.The challenge of sustainable production and consumption patternsNatural Resources forum, Vol. 18, No. 4, pp. 243-246GlobalEconomics, Sustainable development
DS1997-0135
1997
Brune, J.N.Brune, J.N., Ellis, M.A.Structural features in a brittle ductile wax model of continentalextensionNature, Vol. 387, May 1, pp. 67-69MantleStructure, plate tectonics, Rifting
DS201412-0351
2014
Brune, S.Heine, C., Brune, S.Oblique rifting of the Equatorial Atlantic: why there is no Saharan Atlantic Ocean.Geology, Vol. 42, 3, pp. 211-214.AfricaRift zone
DS201608-1395
2016
Brune, S.Brune, S., Williams, S.E., Butterworth, N.P., Muller, R.D.Abrupt plate accelerations shape rifted continental margins.Nature Geoscience, July 18, online 16p.MantleRifting

Abstract: Rifted margins are formed by persistent stretching of continental lithosphere until breakup is achieved. It is well known that strain-rate-dependent processes control rift evolution1, 2, yet quantified extension histories of Earth’s major passive margins have become available only recently. Here we investigate rift kinematics globally by applying a new geotectonic analysis technique to revised global plate reconstructions. We find that rifted margins feature an initial, slow rift phase (less than ten millimetres per year, full rate) and that an abrupt increase of plate divergence introduces a fast rift phase. Plate acceleration takes place before continental rupture and considerable margin area is created during each phase. We reproduce the rapid transition from slow to fast extension using analytical and numerical modelling with constant force boundary conditions. The extension models suggest that the two-phase velocity behaviour is caused by a rift-intrinsic strength-velocity feedback, which can be robustly inferred for diverse lithosphere configurations and rheologies. Our results explain differences between proximal and distal margin areas3 and demonstrate that abrupt plate acceleration during continental rifting is controlled by the nonlinear decay of the resistive rift strength force. This mechanism provides an explanation for several previously unexplained rapid absolute plate motion changes, offering new insights into the balance of plate driving forces through time.
DS201906-1323
2019
Brune, S.Meredith, A.S., Williams, S.E., Brune, S., Collins, A.S., Muller, R.D.Rift and boundary evolution across two supercontinent cycles. Gondwana, RodiniaGlobal and Planetary Change, Vol. 173, pp. 1-14.Globalplate tectonics

Abstract: The extent of continental rifts and subduction zones through deep geological time provides insights into the mechanisms behind supercontinent cycles and the long term evolution of the mantle. However, previous compilations have stopped short of mapping the locations of rifts and subduction zones continuously since the Neoproterozoic and within a self-consistent plate kinematic framework. Using recently published plate models with continuously closing boundaries for the Neoproterozoic and Phanerozoic, we estimate how rift and peri-continental subduction length vary from 1 Ga to present and test hypotheses pertaining to the supercontinent cycle and supercontinent breakup. We extract measures of continental perimeter-to-area ratio as a proxy for the existence of a supercontinent, where during times of supercontinent existence the perimeter-to-area ratio should be low, and during assembly and dispersal it should be high. The amalgamation of Gondwana is clearly represented by changes in the length of peri-continental subduction and the breakup of Rodinia and Pangea by changes in rift lengths. The assembly of Pangea is not clearly defined using plate boundary lengths, likely because its formation resulted from the collision of only two large continents. Instead the assembly of Gondwana (ca. 520 Ma) marks the most prominent change in arc length and perimeter-to-area ratio during the last billion years suggesting that Gondwana during the Early Palaeozoic could explicitly be considered part of a Phanerozoic supercontinent. Consequently, the traditional understanding of the supercontinent cycle, in terms of supercontinent existence for short periods of time before dispersal and re-accretion, may be inadequate to fully describe the cycle. Instead, either a two-stage supercontinent cycle could be a more appropriate concept, or alternatively the time period of 1 to 0 Ga has to be considered as being dominated by supercontinent existence, with brief periods of dispersal and amalgamation.
DS202108-1270
2021
Brune, S.Baes, M., Sobolev, S., Gerya, T., Stern, R., Brune, S.Plate motion and plume-induced subduction inititation.Gondwana Research, Vol. 98, pp. 277-288. pdfSouth Americasubduction

Abstract: Impingement of a hot buoyant mantle plume head on the lithosphere is one of the few scenarios that can initiate a new subduction zone without requiring any pre-existing weak zones. This mechanism can start subduction and plate tectonics on a stagnant lid and can also operate during active plate tectonics where plume-lithosphere interactions is likely to be affected by plate motion. In this study, we explore the influence of plate motion on lithospheric response to plume head-lithosphere interaction including the effect of magmatic weakening of lithosphere. Using 3d thermo-mechanical models we show that the arrival of a new plume beneath the lithosphere can either (1) break the lithosphere and initiate subduction, (2) penetrate the lithosphere without subduction initiation, or (3) spread asymmetrically below the lithosphere. Outcomes indicate that lithospheric strength and plume buoyancy control plume penetration through the lithosphere whereas the plate speed has a subordinate influence on this process. However, plate motion may affect the geometry and dynamics of plume-lithosphere interaction by promoting asymmetry in the subduction zone shape. When a sufficiently buoyant plume hits a young but subductable moving lithosphere, a single-slab modern-style subduction zone can form instead of multiple subduction zones predicted by stagnant lid models. In the case of subduction initiation of older moving oceanic lithosphere, asymmetrical cylindrical subduction is promoted instead of more symmetrical stagnant lid subduction. We propose that the eastward motion of the Farallon plate in Late Cretaceous time could have played a key role in forming one-sided subduction along the southern and western margin of the Caribbean and NW South America.
DS1993-0571
1993
Bruneau, D.Gray, J., Lauriol, B., Bruneau, D., Ricard, J.Post glacial emergence of Ungava Peninsula, and its relationship to glacialhistory.Canadian Journal of Earth Sciences, Vol. 30, No. 8, August pp. 1676-1696.QuebecGeomorphology
DS1997-0136
1997
Bruneau, D.Bruneau, D., Gray, J.T.Ecoulements glaciares et deglaciation hative 11 Ka Bp? du nord est de la peninsule d'Ungava, Quebec.Canadian Journal of Earth Sciences, Vol. 34, pp. 1089-1100.Quebec, Ungava, LabradorGeomorphology - tills
DS2001-0121
2001
BrunelliBonatti, 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
Brunelli, D.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
Brunelli, D.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
Brunelli, D.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
DS200412-0182
2003
Brunelli, D.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
Brunelli, D.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
Brunelli, D.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
DS201608-1419
2016
Brunelli, D.Maia, M., Sichel, S., Briais, A., Brunelli, D., Ligi, M., Ferreira, N., Campos, T., Mougel, B., Brehme, I., Hemond, C., Motoki, A., Moura, D., Scalabrin, C., Pessanha, I., Alves, E., Ayres, A., Oliveira, P.Extreme mantle uplift and exhumation along a transpressive transform fault.Nature Geoscience, Vol. 9, 8, pp. 619-623.MantleRidges

Abstract: Mantle exhumation at slow-spreading ridges is favoured by extensional tectonics through low-angle detachment faults1, 2, 3, 4, and, along transforms, by transtension due to changes in ridge/transform geometry5, 6. Less common, exhumation by compressive stresses has been proposed for the large-offset transforms of the equatorial Atlantic7, 8. Here we show, using high-resolution bathymetry, seismic and gravity data, that the northern transform fault of the St Paul system has been controlled by compressive deformation since ~10?million years ago. The long-lived transpression resulted from ridge overlap due to the propagation of the northern Mid-Atlantic Ridge segment into the transform domain, which induced the migration and segmentation of the transform fault creating restraining stepovers. An anticlockwise change in plate motion at ~11?million years ago5 initially favoured extension in the left-stepping transform, triggering the formation of a transverse ridge, later uplifted through transpression, forming the St Peter and St Paul islets. Enhanced melt supply at the ridge axis due to the nearby Sierra Leone thermo chemical anomaly9 is responsible for the robust response of the northern Mid-Atlantic Ridge segment to the kinematic change. The long-lived process at the origin of the compressive stresses is directly linked to the nature of the underlying mantle and not to a change in the far-field stress regime.
DS201808-1728
2018
Brunelli, D.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
Brunelli, D.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.
DS1900-0111
1902
Bruner, T.K.Bruner, T.K.List of North Carolina DiamondsLetter To G.f. Kunz, Nov. 17TH.United States, North Carolina, Appalachia, MinnesotaDiamond Occurrences
DS1900-0112
1902
Bruner, T.K.Bruner, T.K.Diamond from the J.a.d. Stephenson CollectionLetter To G.f. Kunz, Nov. 26TH.United States, North Carolina, Appalachia, MinnesotaDiamond Occurrences
DS2001-1150
2001
BrunetTardy, 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
DS2000-0116
2000
Brunet, D.Brunet, D., Yuen, D.A.Mantle plumes pinched in the transition zoneEarth and Planetary Science Letters, Vol. 178, No. 1-2, May 15, pp.13-28.MantleMantle plumes, Genesis
DS2001-0139
2001
Brunet, F.Brunet, F., Chazot, G.Partitioning (xenolith) of phosphorous between olivine, clinopyroxene and silicate glass in a spinel lherzoliteChemical Geology, Vol. 176, No. 1-4, July pp. 51-72.GlobalXenoliths, Chemistry
DS200412-0146
2003
Brunet, F.Beyssac, O., Brunet, F., Petitet, J.P., Goffe, B., Rouzard, J.N.Experimental study of the microtextural and structural deformations of carbonaceous materials under pressure and temperature.European Journal of Mineralogy, Vol. 15, no. 6, Dec. 1, pp. 937-951.TechnologyCarbon - UHP
DS200612-0777
2006
Brunet, F.Le Guillou, C., Brunet, F., Rouzand, J.N., Irifune, T., Ohfuji, H.New experimental constraints on nanodiamond formation mechanisms from carbon nanoparticles at high pressure.International Mineralogical Association 19th. General Meeting, held Kobe, Japan July 23-28 2006, Abstract p.161.TechnologyNanodiamonds
DS200712-0434
2007
Brunet, F.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
DS201112-0039
2011
Brunet, F.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
Brunet, F.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
DS201312-0240
2013
Brunet, F.El Atrassi, F., Brunet, F., Chazot, G., Chopin, C.Metamorphic and magmatic overprint of garnet pyroxenites from the Beni Bousera Massif ( northern Morocco): mineralogical, chemical and textural records.Goldschmidt 2013, AbstractAfrica, MoroccoPyroxenite
DS201312-0792
2013
Brunet, F.Schubnel, A., Brunet, F., Hilairet, N., Gasc, J., Wang, Y., Green, H.W.II.Deep focus earthquake analogs recorded at high pressure and temperature in the laboratory.Science, Vol. 341, no. 6152, pp. 1377-1380. Sept. 20TechnologySubduction
DS201412-0221
2014
Brunet, F.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
DS1983-0156
1983
Brunet, J.E.Brunet, J.E.Monopros Limited assessment report on 4 mining cliams in Guigues Temiscamingue County.Quebec Department of Mines, GM 40320QuebecExploration - Assessment, Monopros Limited
DS200712-1044
2006
Brunet, M.F.Stephenson, R.A., Yegorova, T., Brunet, M.F., Stovba, S., Wilson, M., Starostenko, V., Saintot, A., Kusznir, N.Late Paleozoic intra- and pericratonic basins on the East European Craton and its margins.Geological Society of London Memoir, No. 32, pp. 463-480.Europe, Baltic ShieldCraton
DS1994-0222
1994
Brunet, S.Brunet, S., Martignole, J.Nepheline bearing rocks of the reservoir Cabonga area, Grenville ProvinceQuebec: a possible carbonatitic origin.Geological Association of Canada (GAC) Abstract Volume, Vol. 19, p. posterQuebecCarbonatite, Cabonga
DS1995-0220
1995
Brunet, S.Brunet, S., Martignole, J.Gneiss et pegmatites a nepheline du reservoir Cabonga, parc de la VerendryeQuebec Department of Mines, MB 95-04, 35p.QuebecNepheline syenite
DS200412-0231
2004
Bruneton, M.Bruneton, M., Pedersen, H.A., Vacher, P., Kukkonenen, I.T., Arndt, N.T., Funke, S., Friederich, W., Farra, V.Layered lithospheric mantle in the central Baltic Shield from surface waves and xenolith analysis.Earth and Planetary Science Letters, Vol. 226, 1-2, pp. 41-52.Baltic Shield, Norway, Finland, RussiaGeophysics - seismics, xenoliths
DS200612-0187
2005
Bruneton, M.Bruneton, M., Snyder, D.Probing the lithosphere of the Slave Craton through seismic surface wave analysis.32ndYellowknife Geoscience Forum, POSTERCanada, Northwest TerritoriesGeophysics - seismics
DS200612-1064
2006
Bruneton, M.Pedersen, H.A., Bruneton, M., Maupin, V., SVEKALAPKO Seismic Tomography Working GroupLithospheric and sublithospheric anisotropy beneath the Baltic Shield from surface wave array analysis.Earth and Planetary Science Letters, Vol. 244, 3-4, Apr.30, pp. 590-05.Europe, Finland, Baltic ShieldGeophysics - seismics
DS200712-1004
2006
Bruneton, M.Snyder, D., Bruneton, M.The latest Slave mantle architecture and more on kimberlite trends.34th Yellowknife Geoscience Forum, p. 53. abstractCanada, Northwest TerritoriesGeophysics - seismics
DS200712-1005
2006
Bruneton, M.Snyder, D., Bruneton, M.Mantle structure beneath the Wopmay margin of the Slave: Archean or Proterozoic?34th Yellowknife Geoscience Forum, p. 52. abstractCanada, Northwest TerritoriesGeophysics - seismics
DS1970-0770
1973
Brunfelt, A.D.Mitchell, R.H., Brunfelt, A.D., Nixon, P.H.Trace Elements in Magnesian Ilmenites from Lesotho Kimberlites.In: Lesotho Kimberlites, P.h. Nixon, Ed., PP. 230-234.LesothoPetrology
DS1970-0771
1973
Brunfelt, A.O.Mitchell, R.H., Brunfelt, A.O.Rare Earth Element Geochemistry of Kimberlites1st International Kimberlite Conference, EXTENDED ABSTRACT VOLUME, PP. 235-238.Lesotho, South AfricaTransvaal, Swartruggens, Wesselton, Mineral Chemistry
DS1970-0772
1973
Brunfelt, A.O.Mitchell, R.H., Brunfelt, A.O., Nixon, P.H.Ilmenite Association Trace Element Studies. Pt. 2. Trace Element in Magnesian Ilmenites from Lesotho Kimberlites.Maseru: Lesotho Nat. Dev. Corp. Lesotho Kimberlites Editor N, PP. 230-234.LesothoKao, Thaba Putsoa, Mineral Chemistry
DS1970-0773
1973
Brunfelt, A.O.Mitchell, R.H., Carswell, D.A., Brunfelt, A.O.Ilmenite Association Trace Element Studies. Pt. 1. Mineralogy and Rare Earth Geochemistry of an Ilmenite Clinopyroxene Xenolith from the Monastery Mine.Maseru: Lesotho Nat. Dev. Corp. Lesotho Kimberlites Editor N, PP. 224-229.South AfricaMineral Chemistry
DS1975-0142
1975
Brunfelt, A.O.Mitchell, R.H., Brunfelt, A.O.Rare Earth Geochemistry of KimberlitePhysics and Chemistry of the Earth., Vol. 9, PP. 671-686.South AfricaWesselton, Swartruggens, Monastery, Rare Earth Elements (ree), Mineral Chemistry
DS1981-0254
1981
Brunfelt, A.O.Kresten, P., Ahman, E., Brunfelt, A.O.Alkaline Ultramafic Lamprophyres and Associated Carbonatite dykes from the Kalix Area, Northern Sweden.Geologische Rundschau, Vol. 70, No. 3, PP. 1215-1231.Sweden, ScandinaviaAlnoite
DS1970-0965
1974
Brunfelt, O.A.Mitchell, R.H., Brunfelt, O.A.Geochemistry of Scandium, Cobalt and Iron in Rocks of the Fen Alkaline Complex.Earth Planet. Sci. Letters, Vol. 23, PP. 189-192.Norway, ScandinaviaGeochemistry
DS1975-0143
1975
Brunfelt, O.A.Mitchell, R.H., Brunfelt, O.A.Rare Earth Element Geochemistry of the Fen Alkaline Complexnorway.Contributions to Mineralogy and Petrology, Vol. 52, PP. 247-259.Norway, ScandinaviaRare Earth Elements (ree)
DS1986-0113
1986
Brunn, J.H.Brunn, J.H.The sublithospheric mantle, the generation of magmas and SOURCE[ Rev. Geol. DY. (in French)Rev. Geol. DY. (in French), Vol. 27, No. 3-4, pp. 149-161GlobalMantle genesis
DS202103-0381
2021
Bruno, H.Giro, J.P., Almeida, J., Guedes, E., Bruno, H.Tectonic inheritances in rifts: the meaning of NNE lineaments in the continental rift of SE Brazil.Journal of South American Earth Sciences, Vol. 108, 103255. 17p. PdfSouth America, Brazillineaments, tectonics

Abstract: The effect of previous structures inheritance is known to be important in the development of tectonic rifts. A series of overlapping structures generally can be represented by lineaments marking the successive tectonic events. We studied the NNE structural lineaments corridor in the central region of the Ribeira Belt. We used a digital elevation model (DEM) and new and previous fieldwork data to investigate the structural control of such lineaments and their relevance for the Brazilian continental margin. Our results suggest that the NNE direction is a crustal weakness zone characterising corridors of intense ductile and brittle deformation which was recurrently reactivated. Aligned NNE Neoproterozoic-Ordovician ductile and brittle structures as foliations, shear zones, lithological boundaries, and fractures filled by pegmatitic veins coincide with the lineaments. During the Cretaceous rift, a transtensional sinistral regime generated NNE T-fractures filled by mafic dykes. In the Cenozoic, the NNE direction is represented by transfer and domino faults developed within a mega accommodation zone in an intracontinental rift system. Our results suggest that the NNE direction was active in this region throughout the Phanerozoic and has high relevance for the structural development of the continental margin of southeastern Brazil.
DS202111-1760
2021
Bruno, H.Bruno, H., Helibron, M., Strachen, R., Fowler, M., de MorrisonValeriano , C., Bersan, S., Moreira, H., Cutts, K., Dunlop, J., Almeida, R., Almeida, J., Storey, C.Earth's new tectonic regime at the dawn of the Paleozoic: Hf isotope evidence for efficient crustal growth and reworking in the Sao Francisco craton, Brazil.Geology, Vol. 49, 10, pp. 1214-1219. pdfSouth America, Brazilcraton

Abstract: A zircon Hf isotope data set from Archean and Paleoproterozoic magmatic and metasedimentary rocks of the southern São Francisco craton (Brazil) is interpreted as evidence of accretionary and collisional plate tectonics since at least the Archean-Proterozoic boundary. During the Phanerozoic, accretionary and collisional orogenies are considered the end members of different plate tectonic settings, both involving preexisting stable continental lithosphere and consumption of oceanic crust. However, mechanisms for the formation of continental crust during the Archean and Paleoproterozoic are still debated, with the addition of magmatic rocks to the crust being explained by different geodynamic models. Hf isotopes can be used to quantify the proportion of magmatic addition into the crust: positive ?Hf values are usually interpreted as indications of magmatic input from the mantle, whereas crust-derived rocks show more negative ?Hf. We show that the crust of the amalgamated Paleoproterozoic tectonostratigraphic terranes that make up the southern São Francisco craton were generated from different proportions of mantle and crustal isotopic reservoirs. Plate tectonic processes are implied by a consistent sequence of events involving (1) the generation of juvenile subduction-related magmatic arc rocks, followed by (2) collisional orogenesis and remelting of older crust, and (3) post-collisional bimodal magmatism.
DS2002-0576
2002
Bruno, J.Gislason, S.R., Oelkers, E.H., Bruno, J.Geochemistry of crustal fluids: an Andalusian perspectiveChemical Geology, Vol. 190, 1-4, pp.MantleGeochemistry
DS200912-0534
2009
Bruno, M.Nestola, F., Smyth, J.R., Parisatto, M., Secco, L., Princivalle, F., Bruno, M., Prencipe, M., Dal Negro, A.Effects of non-stochiometry on the spinel structure at high pressure: implications for Earth's mantle mineralogy.Geochimica et Cosmochimica Acta, Vol. 73, 2, pp. 489-492.MantleUHP
DS201312-0643
2013
Bruno, M.Nestola, F., Nimis, P., Milani, S., Angel, R., Bruno, M., Harris, J.W.Crystallographic relationships between diamond and its olivine inclusions. An update.Goldschmidt 2013, AbstractRussia, YakutiaUdachnaya
DS201412-0710
2014
Bruno, M.Prencipe, M., Bruno, M., Nestola, F., De La Pierre, M., Nimis, P.Toward an accurate ab initio estimation of compressibility and thermal expansion of diamond in the (0, 3000K) temperature and (0,30 Gpa) pressure ranges, at the hybrid HF/DFT theoretical level.American Mineralogist, Vol. 99, pp. 1147-1154.TechnologyUHP
DS201602-0195
2016
Bruno, M.Bruno, M., Rubbo, M., Aquilano, D., Massaro, F.R., Nestola, F.Diamond and olivine inclusions: a strange relation revealed by ab initio simulations.Earth and Planetary Science Letters, Vol. 435, 1, pp. 31-35.RussiaDeposit - Udachnaya

Abstract: The study of diamond and its solid inclusions is of paramount importance to acquire direct information on the deepest regions of the Earth. However, although diamond is one of the most studied materials in geology, the diamond-inclusion relationships are not yet understood: do they form simultaneously (syngenesis) or are inclusions pre-existing objects on which diamond nucleated (protogenesis)? Here we report, for the first time, adhesion energies between diamond (D) and forsterite (Fo) to provide a crucial contribution to the syngenesis/protogenesis debate. The following interfaces were investigated at quantum-mechanical level: (i) (001)D/(001)Fo, (ii) (001)D/(021)Fo, and (iii) (111)D/(001)Fo. Our data, along with the ones recently obtained on the (110)D/(101)Fo interface, revealed an unexpected thermodynamic behaviour, all interfaces showing almost equal and low adhesion energies: accordingly, diamond and olivine have an extremely low chemical affinity and cannot develop preferential orientations, even during an eventual epitaxial growth. Combining these results with those of our previous work concerning the morphology constraints of diamond on its inclusions, we can state that the two main arguments used so far in favour of diamond/inclusions syngenesis cannot be longer considered valid, at least for olivine.
DS201604-0589
2016
Bruno, M.Agrosi, G., Nestola, F., Tempestra, G., Bruno, M., Scandale, E., Harris, J.X-ray topographic study of a diamond from Udachnaya: implications for the genetic nature of inclusions.Lithos, Vol. 248-251, pp. 153-159.RussiaDeposit - Udachnaya

Abstract: In recent years, several studies have focused on the growth conditions of the diamonds through the analysis of the mineral inclusions trapped in them. In these studies, it is crucial to distinguish between protogenetic, syngenetic and epigenetic inclusions. X-ray topography (XRDT) can be a helpful tool to verify, in a non-destructive way, the genetic nature of inclusions in diamond. With this aim, a diamond from the Udachnaya kimberlite, Siberia, was investigated. The diamond, previously studied by Nestola et al. (2011), has anomalous birefringence and the two largest olivines have typical “diamond-imposed” shapes. The study of the topographic images shows that the diamond exhibits significant deformation fields related to post growth plastic deformation. The absence of dislocations starting from the olivine inclusions, and the dark contrasts around them represent the main results obtained by XRDT, contributing to the elucidation of the relationships between the diamond and the olivines at the micron-meter scale. The dark halo surrounding the inclusions was likely caused by the effect of different thermo-elastic properties between the diamond and the inclusions. The absence of dislocations indicates that the diamond-imposed morphology did not produce the volume distortion commonly associated with the entrapment of the full-grown inclusions and, thus, only based on such evidence, a syngenetic origin could be proposed. In addition, stepped figures optically observed at the interface between diamond and one of the olivines suggest processes of selective partial dissolution that would contribute to a change in the final morphology of inclusions. These results show that a diamond morphology may be imposed to a full-grown (protogenetic) olivine during their encapsulation, suggesting that the bulk of the inclusion is protogenetic, whereas its more external regions, close to the diamond-inclusion interface, could be syngenetic.
DS201112-0122
2011
Bruno, R.Bruno, R., Kenji, M., de Moortele, B.V.Electrical conductivity of the serpentinized mantle and fluid flow in subduction zones.Earth and Planetary Science Letters, Vol. 307, 3-4, pp. 387-394.MantleGeophysics - seismics
DS201412-0620
2014
Bruno, S.Nestola,F., Nimis, P.,Angel, R.J., Milani, Bruno, S.,Prencipe, M., Harris, J.W.Olivine with diamond-imposed morphology included in diamonds. Syngenesis or Protogenesis.International Geology Review, Vol. 56, 13, pp. 1658-1667.RussiaDeposit - Udachnaya
DS1985-0091
1985
Bruno, S.A.Bruno, S.A.Pan Genesis in the Southern KalahariProceedings of a seminar on the mineral exploration of the Kalahari, Geol., Vol. 29, pp. 261-277BotswanaGeomorphology
DS1997-0137
1997
Bruns, P.Bruns, P., Rakoczy, H., Dullo, W. Ch.Slow sedimentation and Ir anomalies at the Cretaceous/ Tertiary boundaryGeologische Rundschau, Vol. 86, No. 1, pp. 168-177GlobalBoundary, Iridium anomalies
DS1992-0659
1992
Brunstead, K.A.Hammond, P.E., Brunstead, K.A.Possible hotspot track in the Pacific northwestGeological Society of America (GSA) Abstract Volume, Vol. 24, No. 5, May p. 30. abstract onlyOregon, WashingtonHot spot, Geochemistry
DS201601-0004
2015
Brunton, F.R.Bancroft, A.M., Brunton, F.R., Kleffner, M.A., Jin, J.Silurian condodont biostratigraphy and carbon isotope stratigraphy of the Victor mine core in the Moose River basin.Canadian Journal of Earth Sciences, Vol. 52, 12, pp. 1169-1181.Canada, Ontario, AttawapiskatDeposit - Victor

Abstract: The Moose River Basin in Ontario, Canada, contains nearly 1 km of Silurian marine strata, and although it has been studied for more than a century, its precise correlation globally has not been constrained. Herein, a core from the Victor Mine in the Moose River Basin was examined for conodont biostratigraphy and carbonate carbon (?13Ccarb) isotope chemostratigraphy to provide a detailed chronostratigraphic framework for the Silurian strata (Severn River, Ekwan River, and Attawapiskat formations) in the Moose River Basin. The recovery of Aspelundia expansa, Aspelundia fluegeli fluegeli, Distomodus staurognathoides, Ozarkodina polinclinata estonica, Pterospathodus eopennatus, and Aulacognathus bullatus, as well as the lower Aeronian, upper Aeronian, lower Telychian (Valgu), and ascending limb of the Sheinwoodian (Ireviken) positive carbonate carbon (?13Ccarb) isotope excursions provide significantly improved chronostratigraphic correlation of Llandovery strata in the Moose River Basin. Silurian Conodont Biostratigraphy and Carbon (?13Ccarb) Isotope Stratigraphy of the Victor Mine (V-03-270-AH) Core in the Moose River Basin.
DS201602-0192
2015
Brunton, F.R.Bancroft, A.M., Brunton, F.R., Kleffner, M.A.Silurian conodont biostratigraphy and carbon ( delta 13 C carb) isotope stratigraphy of the Victor mine ( V-03-270-AH) core in the Moose River Basin.Canadian Journal of Earth Sciences, Vol. 52, pp. 1169-1181.Canada, Ontario, AttawapiskatDeposit - Victor

Abstract: The Moose River Basin in Ontario, Canada, contains nearly 1 km of Silurian marine strata, and although it has been studied for more than a century, its precise correlation globally has not been constrained. Herein, a core from the Victor Mine in the Moose River Basin was examined for conodont biostratigraphy and carbonate carbon (13Ccarb) isotope chemostratigraphy to provide a detailed chronostratigraphic framework for the Silurian strata (Severn River, Ekwan River, and Attawapiskat formations) in the Moose River Basin. The recovery of Aspelundia expansa, Aspelundia fluegeli fluegeli, Distomodus staurognathoides, Ozarkodina polinclinata estonica, Pterospathodus eopennatus, and Aulacognathus bullatus, as well as the lower Aeronian, upper Aeronian, lower Telychian (Valgu), and ascending limb of the Sheinwoodian (Ireviken) positive carbonate carbon (13Ccarb) isotope excursions provide significantly improved chronostratigraphic correlation of Llandovery strata in the Moose River Basin.
DS1960-0430
1964
Brunton, J.H.Brunton, J.H.The Mechanical Properties of DiamondDiamond Research, pp. 2-12.GlobalDiamond - Morphology, Thermal Conductivity
DS201012-0075
2010
Brusentsova, T.N.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
DS201507-0306
2015
Brushan, S.K.Brushan, S.K.Geology of the Kamthai rare earth deposit. Journal of the Geological Society of India, Vol. 85, 5, pp. 537-546.India, RajasthanCalciocarbonatite

Abstract: A wide spectrum of calciocarbonatites and associated alkaline rocks are exposed around Kamthai, Rajasthan. The mineralogical studies exhibit a bimodal distribution of REE minerals. The southeastern block has carbocernaite and the eastern block has bastnaesite ± ancylite / synchysite as the dominant REE minerals followed by parisite and other accessory minerals. Calcite is the most abundant of the gangue phase, followed by biotite, albite, k-feldspar and iron oxide / hydroxide. Minor and trace gangue phases include pyrite, ilmenite, apatite, siderite, ankerite, amphibole, pyroxene, strontianite, barite, ilmenite / pyrophanite, celestine, clay minerals, sphalerite, pyrochlore, fluorite and Mn-rich phases including hollandite and Mn-Fe oxides. Calciocarbonatite occuring as intrusive veins, sills/dykes and plug, is perhaps a product of crystallization of a primary carbonatite melt generated at upper mantle. The first phase magmatic calciocarbonatite is alvikite type, rich in carbocernaite whereas second hydrothermal phase, sovite type, is enriched in bastnaesite. The absence of supergene activity and minerals (crandalite, florencite, gorceixite) indicate minor role of secondary enrichment. A rift-related mechanism, thermal equivalent to Deccan flood basalt (65±2 Ma), invoking "Reunion plume - continental hot spot" might have triggered Tertiary alkaline magmatism.
DS1930-0154
1934
Brustier, L.Brustier, L.Sur le Diamant du Kouango Francais (aef)Rev. Ind. Min. (st. Etienne), AUG. 15TH., PP. 435-436.West Africa, French Equatorial Africa, Central African RepublicDiamond
DS1989-0188
1989
Brutin, D. de.Brutin, D. de.Chemical characterization of upper mantle-derivedxenoliths from the Schuller kimberliteDepartment of Mineral and Energy Affairs, Annual technical report of Geol., pp. 128-129South AfricaXenoliths, Geochemistry
DS1960-0024
1960
Bruton, E.Bruton, E.Diamond Mining in GuineaThe Gemologist., Vol. 29, No. 348, JULY, PP. 121-131.Guinea, West AfricaMining, History
DS1960-0129
1961
Bruton, E.Bruton, E.The True Book about DiamondsLondon: F. Muller., 144P.GlobalHistory, Geology, Kimberley
DS1970-0040
1970
Bruton, E.Bruton, E.Diamonds; Chilton Press, 1970Chilton Press, 532P. PP. 79; 94-95; 158-163; 356.Botswana, Canada, QuebecBlank
DS1970-0041
1970
Bruton, E.Bruton, E.Diamonds; Chilton Publishing Co., 1970Pennsylvania: Chilton Publishing Co., 532P.South Africa, GlobalKimberley, History, Geology, Production
DS1970-0640
1973
Bruton, E.Bruton, E.Diamonds 1973Radnor Pa: Chilton Publishing, 372P.South Africa, Global, Southwest Africa, NamibiaHistory, Geology, Kimberley, Janlib, Textbook
DS1975-0708
1978
Bruton, E.Bruton, E.Prospecting in the KalahariChilton Press, SECOND EDITION, 532P. PP. 159-163.BotswanaDiamond Prospecting, Orapa Discovery, Lamont, Marx
DS1975-0709
1978
Bruton, E.Bruton, E.Diamonds; 1978Radnor, Pa.:chilton., 2ND. EDITION, 532P.GlobalKimberlite, Kimberley, Janlib, Diamond
DS2001-0049
2001
Bruzak, G.Arndt, N., Bruzak, G., Reischmann, T.The oldest continental and oceanic plateaus: geochemistry of basalts and komatiites Pilbara CratonGeological Society of America Special Paper, Special Paper. 352, pp. 359-88.AustraliaBasalts, Craton
DS200412-1208
2003
Bryachaninova, N.I.Makeyev, A.B., Iwanuch, W., Obyden, S.K., Bryachaninova, N.I., Saparin, G.V.Inter relation of diamond and carbonado ( based on study of collections from Brazil and Middle Timan).Doklady Earth Sciences, Vol. 393a, no. 9, pp.1251-5.Russia, South America, BrazilDiamond morphology
DS1998-0528
1998
bryanGraham, I., Burgess, bryan, Ravenscroft, Thomas, DoyleThe Diavik kimberlites - Lac de Gras, Northwest Territories, Canada7th International Kimberlite Conference Abstract, pp. 259-61.Northwest TerritoriesHistory, kimberlite, evaluation, Deposit - Diavik
DS2002-0831
2002
BryanKerr, D., Budkewitsch, P., Bryan, Knight, KjarsgaardSurficial geology, spectral reflectance characteristics, and their influence on hyperspectralGeological Survey of Canada Current Research, 2002-04, 8p.Northwest TerritoriesImaging - drift prospecting technique for kimberlite, Deposit - Diavik mine
DS1992-0180
1992
Bryan, D.Bryan, D., Frazer, J.Diamond exploration methodsNorthwest Territories Geoscience Forum held November 25, 26th. 1992, AbstractNorthwest TerritoriesExploration
DS1998-0175
1998
Bryan, D.Bryan, D., Burgess, J.The Diavik project kimberlites, Slave Province, Northwest TerritoriesGeological Society of America (GSA) Annual Meeting, abstract. only, p.A245.Northwest TerritoriesExploration - history outline, Deposit - Diavik project
DS1998-0176
1998
Bryan, D.Bryan, D., Burgess, J., Graham, I., Ravenscroft, P.The Diavik kimberlites - Lac de Gras, Northwest Territories, Canada.Calgary Mining Forum, Apr. 8-9, p. 40-2. abstractNorthwest TerritoriesGeology, Deposit - Diavik
DS200812-0150
2007
Bryan, S.E.Bryan, S.E., Ernst, R.E.Revised definition of Large Igneous Provinces (LIPs).Earth Science Reviews, Vol. 86, 1-4, pp. 175-202.MantleBasalts
DS201711-2528
2017
Bryan, S.E.Siegel, C., Bryan, S.E., Allen, C.M.Use and abuse of zircon based thermometers: a critical review and a recommended approach to identify antecrystic zircons.Earth-Science Reviews, Vol. 176, pp. 87-116.Technologygeothermometry

Abstract: Zircon- and bulk-rock Zr-based thermometric parameters have become fundamental to petrogenetic models of magmatism, from which broader geochronological and tectonic implications are being made. In particular, petrogenetic models have become increasingly reliant on Ti concentration in zircon geothermometry (TZircTi) and zircon saturation temperature (TZircsat). A feature of many of these studies is an implicit assumption that all zircons present in the host igneous rock are autocrystic, that is, crystallised from the surrounding melt. However, it has long been recognised that zircons present in an igneous rock can be inherited either from the surrounding country rock or source region (xenocrysts), or from earlier phases of magmatism or the magmatic plumbing system (antecrysts). Distinguishing these different origins for zircon crystals or domains within crystals is not straightforward. Here, we first review the utility and reliability of zircon-based thermometers for petrogenetic studies and show that TZircsat is a theoretical temperature and cannot be used to constrain magmatic or partial melting temperatures. It is a dynamic variable that changes during magma crystallisation, and essentially increases as fractional crystallisation proceeds, whereas true magmatic temperatures (TMagma) decrease. Generally, in Temperature-SiO2 space, the cross-over point of these two temperatures is magmatic system dependent, and also affected by the type of calibration used for the TZircsat calculations. Consequently, each magmatic system needs to be evaluated independently to assess the validity and usefulness of TZircsat. A fundamental conclusion of TZircsat and TMagma relationships assessed here is that new zircon generally only crystallises in silicic (granitic/rhyolitic) melt compositions, and thus autocrystic zircons should not be assumed to be present in igneous rocks with bulk compositions < 64 wt% SiO2, although inherited and minor zircons crystallising from late-stage differentiated melt pockets can be present. This highlights the importance of discriminating autocrystic from inherited zircons in igneous rocks. We then review techniques available to discriminate autocrystic from inherited zircons, and propose a new methodology to assist in the identification of autocrystic zircons for emplacement age determination and separate evaluation of inherited zircon components. The approach uses two strands of data: 1) zircon data such as zircon morphologies, textures, compositions and U-Pb ages, and 2) whole-rock data, in particular SiO2 and coupled geothermometry (TZircsat and TMagma) to estimate whether the magma was zircon-saturated or undersaturated. To test this new protocol, we use as examples, several Phanerozoic granitic rocks intersected by drilling in Queensland where contextual information is limited, and show how antecrystic and xenocrystic zircons and monazites can be distinguished. In contrast, where zircons are metamict (for example, high U and Th-rich zircons), much of the ability to discriminate is impacted because such zircons have suffered Pb loss and have modified compositions (e.g., higher TZircTi). We recommend an integrated approach incorporating whole-rock chemistry, independent geothermometric constraints, zircon composition, textures and ages obtained by routine cathodoluminescence and LA-ICP-MS or ion microprobe analysis to provide increased confidence for the discrimination of inherited zircons from autocrystic zircons and determination of the emplacement age.
DS201712-2730
2017
Bryan, S.E.Siegel, C., Bryan, S.E., Allen, C.M., Gust, D.A.Use and abuse of zircon based thermometers: a critical review and recommended approach to identify antecrystic zircons.Earth Science Reviews, Vol. 176, 10.1016Technologygeothermometry

Abstract: Zircon- and bulk-rock Zr-based thermometric parameters have become fundamental to petrogenetic models of magmatism, from which broader geochronological and tectonic implications are being made. In particular, petrogenetic models have become increasingly reliant on Ti concentration in zircon geothermometry (TZircTi) and zircon saturation temperature (TZircsat). A feature of many of these studies is an implicit assumption that all zircons present in the host igneous rock are autocrystic, that is, crystallised from the surrounding melt. However, it has long been recognised that zircons present in an igneous rock can be inherited either from the surrounding country rock or source region (xenocrysts), or from earlier phases of magmatism or the magmatic plumbing system (antecrysts). Distinguishing these different origins for zircon crystals or domains within crystals is not straightforward. Here, we first review the utility and reliability of zircon-based thermometers for petrogenetic studies and show that TZircsat is a theoretical temperature and cannot be used to constrain magmatic or partial melting temperatures. It is a dynamic variable that changes during magma crystallisation, and essentially increases as fractional crystallisation proceeds, whereas true magmatic temperatures (TMagma) decrease. Generally, in Temperature-SiO2 space, the cross-over point of these two temperatures is magmatic system dependent, and also affected by the type of calibration used for the TZircsat calculations. Consequently, each magmatic system needs to be evaluated independently to assess the validity and usefulness of TZircsat. A fundamental conclusion of TZircsat and TMagma relationships assessed here is that new zircon generally only crystallises in silicic (granitic/rhyolitic) melt compositions, and thus autocrystic zircons should not be assumed to be present in igneous rocks with bulk compositions < 64 wt% SiO2, although inherited and minor zircons crystallising from late-stage differentiated melt pockets can be present. This highlights the importance of discriminating autocrystic from inherited zircons in igneous rocks. We then review techniques available to discriminate autocrystic from inherited zircons, and propose a new methodology to assist in the identification of autocrystic zircons for emplacement age determination and separate evaluation of inherited zircon components. The approach uses two strands of data: 1) zircon data such as zircon morphologies, textures, compositions and U-Pb ages, and 2) whole-rock data, in particular SiO2 and coupled geothermometry (TZircsat and TMagma) to estimate whether the magma was zircon-saturated or undersaturated. To test this new protocol, we use as examples, several Phanerozoic granitic rocks intersected by drilling in Queensland where contextual information is limited, and show how antecrystic and xenocrystic zircons and monazites can be distinguished. In contrast, where zircons are metamict (for example, high U and Th-rich zircons), much of the ability to discriminate is impacted because such zircons have suffered Pb loss and have modified compositions (e.g., higher TZircTi). We recommend an integrated approach incorporating whole-rock chemistry, independent geothermometric constraints, zircon composition, textures and ages obtained by routine cathodoluminescence and LA-ICP-MS or ion microprobe analysis to provide increased confidence for the discrimination of inherited zircons from autocrystic zircons and determination of the emplacement age.
DS1989-1259
1989
Bryan, W.B.Reid, J.B. Jr., Steig, E., Bryan, W.B.Major element evolution of basaltic magmas: a comparison of the information in CMAS and ALFE projectionsContributions to Mineralogy and Petrology, Vol. 101, No. 3, pp. 318-325GlobalMagma Geochemistry, Basalt
DS1993-0476
1993
Bryan, W.B.Gaetani, G.A., Grove, T.L., Bryan, W.B.The influence of water on the petrogenesis of subduction related igneousrocksNature, Vol. 365, No. 6444, September 23, pp. 332-335GlobalSubduction, Igneous rocks, Mantle
DS201601-0051
2015
Bryanchaniniova, N.I.Yang, J.S., Wirth, R., Wiedenbeck, M., Griffin, W.L., Meng, F.C., Chen, S.Y., Bai, W.J., Xu, X.X., Makeeyev, A.B., Bryanchaniniova, N.I.Diamonds and highly reduced minerals from chromitite of the Ray-Iz ophiolite of the Polar Urals: deep origin of podiform chromitites and ophiolitic diamonds.Acta Geologica Sinica, Vol. 89, 2, p. 107.Russia, Polar UralsOphiolite
DS201112-0555
2011
Bryanchaninova, N.Krovolutskaya, N., Bryanchaninova, N.Olivines of igneous rocks.Russian Journal of General Chemistry, Vol. 81, 6, pp. 1302-1314.TechnologyOlivine, petrology
DS2000-0608
2000
Bryanchaninova, N.I.Makeyev, A.B., Dudar, V.A., Bryanchaninova, N.I.Original rocks of Uralian and Timanian diamondsIgc 30th. Brasil, Aug. abstract only 1p.Russia, Urals, TimanDiamond - morphology, Deposit - Ichetju
DS2002-0989
2002
Bryanchaninova, N.I.Makeev, A.B., Kisel, S.I., Sobolev, V.K., Filippov, V.N., Bryanchaninova, N.I.Native metals in kimberlite pipe aureoles of the Arkhangelsk Diamondiferous provinceDoklady Earth Sciences, Vol. 385A, 6, pp. 714-8.Russia, Kola Peninsula, ArkangelskGeochemistry, Deposit - Arkangel area
DS200912-0465
2009
Bryanchaninova, N.I.Makeev, A.B., Andriechev, V.L., Bryanchaninova, N.I.Age of lamprophyres of the Middle Timan: first Rb-Sr data.Doklady Earth Sciences, Vol. 427, 4, pp. 584-587.RussiaLamprophyre
DS201012-0076
2010
Bryanchaninova, N.I.Bryanchaninova, N.I., Makeev, A.B.Garnet of the pyrope majorite series.International Mineralogical Association meeting August Budapest, abstract p. 152.Russia, Timan, South America, BrazilUHP
DS201012-0467
2010
Bryanchaninova, N.I.Makeev, A.B., Bryanchaninova, N.I.Lamprophyres of Middle Timan, Russia.International Mineralogical Association meeting August Budapest, abstract p. 574.Russia, TimanLamprophyre
DS201507-0320
2015
Bryanskaya, A.V.Lazereva, E.V., Zhmodik, S.M., Dobretsov, N.L., Tolstov, A.V., Shcherbov, B.L., Karmanov, N.S., Gerasimov, E.Yu., Bryanskaya, A.V.Main minerals of abnormally high grade ores of the Tomtor deposit ( Arctic Siberia).Russian Geology and Geophysics, Vol. 56, pp. 844-873.RussiaDeposit - Tomtor
DS202104-0571
2021
Bryanskaya, A.V.Dobretsov, N.L., Zhmodik, S.M., Lazareva, E.V., Bryanskaya, A.V., Ponomarchuk, V.A., Saryg-ool, B. Yu., Kirichenko, I.S., Tolstov, A.V., Karmanov, N.S.Structural and morphological features of the participation of microorganisms in the formation of Nb-REE-rich ores of the Tomtor field, Russia.Doklady Earth Sciences, Vol. 496, pp. 135-138. Russiadeposit - Tomtor

Abstract: Data indicating the important role of microorganisms in the redistribution of REEs in the weathering crust and the decisive role in the concentration of REEs during the formation of ores in the upper ore horizon of the Tomtor field are obtained. The uptake of REEs was carried out by the community of microorganisms, such as phototrophs, methanogens, methanotrophs, and proteobacteria, which form the basis of the microbiocenosis for this paleoecosystem. The isotopic composition of C carbonates in all samples studied with fossilized microorganisms corresponds to the biogenic one, and the isotopic composition ?18?SMOW (from 7 to 20‰) indicates the endogenous (hydrothermal) and, to a lesser extent, exogenous nature of the solutions. The low (87Sr/86Sr)I values of carbonates (~0.7036-0.7042) exclude the participation of seawater.
DS1983-0157
1983
Bryant, B.Bryant, B.Structural Ancestry of the Uinta MountainsGeological Society of America (GSA), Vol. 15, No. 4, P. 318, (abstract.).GlobalMid-continent
DS1993-0450
1993
Bryant, K.Foose, M.P., Bryant, K.Annotated bibliography of metallogenic maps ( 1960-1987)United States Geological Survey (USGS) Open File, No. 93-0208 A, B, paper copy $ 14.00 disc $ 10.00United StatesMap -bibliography, Metallogenic maps
DS1995-0221
1995
Bryant, T.Bryant, T.Metallic and industrial mineral assessment report for the Fort Saskatchewan area.Alberta Geological Survey, MIN 19950013AlbertaExploration - assessment
DS1995-0222
1995
Bryant, T.Bryant, T.Northside Resources 1993 bulk sampling Program Groat Creek, Beaver Paddle River.Alberta Geological Survey, MIN 19950021AlbertaExploration - assessment
DS1995-0223
1995
Bryant, T.Bryant, T., Cantin, B., Stweart, R., Sraega, D.Metallic and industrial mineral assessment report for the Pembin a field sampling project.Alberta Geological Survey, MIN 19950016AlbertaExploration - assessment
DS1995-0263
1995
Bryant, T.Cantin, R.G., Stewart, R.J., Bryant, T.Metallic and industrial mineral assessment report for the Crowsnest volcanics study.Alberta Geological Survey, MIN 19950010AlbertaExploration - assessment
DS1990-0193
1990
Bryant, W.R.Bennett, R.H., Bryant, W.R., Hulbert, M.H.Microstructure of fine grained sediments- from mud to shaleSpringer Verlag, 458p. $ approx. $ 98.00GlobalBook -ad, Sediments -fine grained
DS2002-0892
2002
Bryantseva, G.V.Kostenko, N.P., Bryantseva, G.V.Orogenic structural features in the southern part of the Polar UralsMoscow University Geology Bulletin, Vol. 57, 2. pp. 1-5.Russia, UralsTectonics
DS200412-1046
2002
Bryantseva, G.V.Kostenko, N.P., Bryantseva, G.V.Orogenic structural features in the southern part of the Polar Urals.Moscow University Geology Bulletin, Vol. 57, 2. pp. 1-5.Russia, UralsTectonics
DS1860-1023
1898
Bryce, J.Bryce, J.Impressions of South AfricaLondon: Macmillan., 604P. 2ND. EDITION.Africa, South AfricaHistory, Politics, Travelogue
DS200712-0338
2007
Bryce, J.Furman, T., Van Keken, P.E., Bryce, J., Lin, S-C.Thermochemical coupling in deep mantle plumes: a case study of Turkana Northern Kenya.Plates, Plumes, and Paradigms, 1p. abstract p. A300.Africa, KenyaAlkaline rocks, picrites
DS1998-1464
1998
Bryce, J.G.Tilton, G.R., Bryce, J.G., Mateen, A.lead, Strontium, and neodymium isotope dat a from 30 and 300 Ma collision zone carbonatites in northwest Pakistan #2Journal of Petrology, Vol. 39, No. 11-12, Nov-Dec. pp. 1865-74.PakistanCarbonatite, Geochronology
DS1998-1465
1998
Bryce, J.G.Tilton, G.R., Bryce, J.G., Mateen, A.lead, Strontium, neodymium isotope dat a from 30 and 300 Ma collision zone carbonatites in Northwest Pakistan #1Mineralogical Magazine, Goldschmidt abstract, Vol. 62A, p. 1521-2.PakistanCarbonatite, Geochronology
DS201112-0088
2011
Bryce, J.G.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
DS1860-0621
1889
Bryden, H.A.Bryden, H.A.Kloof and KarrooLondon: Longmans Green And Co., South Africa, Cape ProvinceTravelogue
DS1860-0973
1897
Bryden, H.A.Bryden, H.A.The Victorian Era in South AfricaLondon: The African Critic., 102P.South AfricaHistory
DS1860-0974
1897
Bryden, H.A.Bryden, H.A.Impression of South AfricaLondon: Macmillan., South AfricaHistory
DS1910-0495
1916
Bryden, H.A.Bryden, H.A.Diamonds in German Southwest Africa. Statistics 1908-1913Chambers's Journal, DECEMBER PP. 779-781.Southwest Africa, NamibiaProduction
DS1920-0327
1927
Bryden, H.A.Bryden, H.A.The Romance of South African DiamondFortnightly Review (London), Vol. 121, PP. 788-797. ALSO Publishing LONDON; CHAPMAN and HALLSouth AfricaHistory, Kimberley
DS1960-1084
1969
Bryhni, I.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
DS1970-0255
1971
Bryhni, I.Bryhni, I., Griffin, W.L.Zoning in Eclogite Garnets from Nordfiord, West NorwayContributions to Mineralogy and Petrology, Vol. 32, PP. 112-125.Norway, ScandinaviaPetrography
DS1990-0888
1990
Bryhni, I.Krogh, E.T., Andresen, A., Bryhni, I., Broks, T.M., KristenesenEclogites and polyphase P-T cycling in the Caledonian uppermost allochthonin Troms, northern NorwayJournal of Metamorphic Geology, Vol. 8, No. 3, May pp. 289-310NorwayEclogites
DS201312-0104
2013
Bryksin, A.Bryksin, A.Project NA13: towards an updated tomographic model of the Canadian lithosphere.GEM Diamond Workshop Feb. 21-22, Noted onlyCanadaTomography
DS201810-2391
2018
Bryksin, A.Zaporozan, T., Fredericksen, A.W., Bryksin, A., Darbyshire, F.Surface wave images of western Canada: lithographic variations across the Cordillera craton boundary.Canadian Journal of Earth Sciences, Vol. 55, pp. 887-896.Canada, Northwest Territories, Alberta, Saskatchewangeophysics - seismic

Abstract: Two-station surface-wave analysis was used to measure Rayleigh-wave phase velocities between 105 station pairs in western Canada, straddling the boundary between the tectonically active Cordillera and the adjacent stable craton. Major variations in phase velocity are seen across the boundary at periods from 15 to 200 s, periods primarily sensitive to upper mantle structure. Tomographic inversion of these phase velocities was used to generate phase velocity maps at these periods, indicating a sharp contrast between low-velocity Cordilleran upper mantle and high-velocity cratonic lithosphere. Depth inversion along selected transects indicates that the Cordillera-craton upper mantle contact varies in dip along the deformation front, with cratonic lithosphere of the Taltson province overthrusting Cordilleran asthenosphere in the northern Cordillera, and Cordilleran asthenosphere overthrusting Wopmay lithosphere further south. Localized high-velocity features at sub-lithospheric depths beneath the Cordillera are interpreted as Farallon slab fragments, with the gap between these features indicating a slab window. A high-velocity feature in the lower lithosphere of the Slave province may be related to Proterozic or Archean subduction.
DS1992-1220
1992
Bryndzia, L. T.Popp, R.K., Bryndzia, L. T.Statistical analysis of Fe3, Ti, and OH in kaersutite from alkalic Igneous rocks and mafic mantle xenoliths.American Mineralogist, Vol. 77, No. 11-12, November-December, pp. 1250-1257.GlobalMineralogy, Mantle xenoliths
DS1989-0189
1989
Bryndzia, L.T.Bryndzia, L.T., Wood, B.J., Dick, H.J.B.The oxidation state of the earth's sub-oceanic mantle from oxygen thermobarometry of abyssal spinelperidotitesNature, Vol. 341, October 12, pp. 526-527. Database # 18208GlobalMantle, Peridotite
DS1990-0247
1990
Bryndzia, L.T.Bryndzia, L.T., Wood, B.J.Oxygen thermobarometry of abyssal spinel peridotites: the Redox state and C-O-H volatile composition of the earth's sub-oceanic upper mantleAmerican Journal of Science, Vol. 290, December pp. 1093-1116GlobalMantle, Peridotites, experimental petrology
DS1990-0771
1990
Bryndzia, L.T.Johnson, K.E., Davis, A.M., Bryndzia, L.T.Trace element variations in coexisting clinopyroxene and amphibole:implications for mantle MetasomatismGeological Society of America (GSA) Annual Meeting, Abstracts, Vol. 22, No. 7, p. A256CaliforniaDish Hill, Mantle Metasomatism
DS1990-1577
1990
Bryndzia, L.T.Wood, B.J., Bryndzia, L.T., Johnson, K.E.Mantle oxidation state and its relationship to tectonic environment and fluid speciationScience, Vol. 248, No. 4953, April 20, pp. 337-345GlobalTectonics, Mantle genesis
DS1992-1221
1992
Bryndzia, L.T.Popp, R.K., Bryndzia, L.T.Statistical analysis of iron, Ti and OH in kaersutite from alkalic igneous rocks and mafic mantle xenoliths.American Mineralogist, Vol. 77, pp. 1250-57.MantleXenoliths
DS1996-0692
1996
Bryndzia, L.T.Johnson, K.E., Davis, A.M., Bryndzia, L.T.Contrasting styles of hydrous metasomatism in the upper mantle: an ion microprobe investigation.Geochimica et Cosmochimica Acta, Vol. 60, No. 8, April pp. 1367-85.MantleXenoliths, Metasomatism
DS1960-0130
1961
Brynner, L.Brynner, L.Breccia and Pebble Columns Associated with Epigenetic Ore Deposits.Economic Geology, Vol. 56, PP. 488-508.GlobalBreccia
DS1991-0934
1991
Bryskin, A.V.Krylov, S.V., Mishenkin, B.P., Bryskin, A.V.Deep structure of the Baikal rift from multiwave seismic explorationsJournal of Geodynamics, Vol. 13, No. 1, pp. 87-96RussiaTectonics, Structure
DS202104-0567
2021
Brzozowski, M.Brzozowski, M., Samson, I.M., Gagnon, J.E., Linnen, R.L., Good, D.J.Effects of fluid-induced oxidation on the composition of Fe-Ti oxides in the eastern gabbro, Coldwell Complex, Canada: implications for the application of Fe-Ti oxides to petrogenesis and mineral exploration.Mineralium Deposita, Vol. 56, pp. 601-618. pdfCanada, Ontariodeposit - Coldwell

Abstract: Magnetite (mag)-ilmenite (ilm) intergrowths are more common than mag-ulvöspinel (usp) intergrowths in mafic-ultramafic Ni-Cu-PGE systems, yet the former has no known solid solution. The most accepted model for the formation of mag-ilm intergrowths in terrestrial environments is fluid-induced oxidation of mag-usp assemblages by oxygen in water. In this study, we re-examine this model in light of the fact that crustal fluids have very low pO2 and that mag-ilm intergrowths commonly occur in rocks that show little or no evidence of hydrothermal alteration. We also characterize the chemical changes that occurred during the formation of mag-ilm intergrowths and how they affect the use of Fe-Ti oxide chemistry for petrogenesis and mineral exploration. In the Eastern Gabbro, Coldwell Complex, a continuum of Fe-Ti oxide intergrowths occur ranging from cloth (mag-usp) to trellis (mag-ilm) types. Trellis-textured intergrowths have higher bulk Fe3+:Fe2+ ratios and are predominantly enriched not only in some multivalent (Ge, Mo, W, Sn) elements, but also in Cu and Ga, consistent with their formation via oxidation by a metal-rich fluid. These compositional changes are significant relative to typical elemental abundances in Fe-Ti oxides and could potentially lead to erroneous interpretations regarding primary magmatic processes if they are not taken into consideration. The irregular distribution of the intergrowths throughout the Eastern Gabbro suggests that different rock series and mineralized zones experienced variable degrees of fluid-induced oxidation. It is proposed that C in CO2 rather than O2 in water could potentially be an important oxidizing agent in mafic systems: 9Fe2+2TiO4+0.75CO2+1.5H2O?9Fe2+TiO3+3Fe3+2Fe2+O4+0.75CH4. The applicability of this model is supported by the common occurrence of CO2 and CH4 in fluid inclusions in mafic rocks.
DS202104-0568
2021
Brzozowski, M.J.Brzozowski, M.J., Samson, I.M., Gagnon, J.E., Good, D.J., Linnen, R.L.Oxide mineralogy and trace element chemistry as an index to magma evolution and Marathon-type mineralization in the eastern gabbro of the alkaline Coldwell Complex, Canada.Mineralium Deposita, Vol. 56, pp. 621-642. pdfCanada, Ontariodeposit - Coldwell

Abstract: The Eastern Gabbro of the alkaline Coldwell Complex, Canada, represents a Ni-poor conduit-type system that comprises two rock series, the Layered Series and Marathon Series, which intruded into a metabasalt package. Based on distinct variations in magnetite compatible (e.g., Ni, Cr) and incompatible (e.g., Sn, Nb) elements in Fe-Ti oxide intergrowths, the metabasalts, Layered Series, and Marathon Series must have crystallized from magmas that originated from compositionally distinct sources. Of these rock units, the metabasalts crystallized from a more primitive melt than the Layered Series as Fe-Ti oxides in the former have higher concentrations of magnetite-compatible elements. Unlike the metabasalts and Layered Series, the Marathon Series crystallized from multiple, compositionally distinct magmas as Fe-Ti oxides in this series exhibit large variations in both magnetite compatible and incompatible elements. Accordingly, the various rock types of the Marathon Series cannot be related by fractional crystallization of a single batch of magma. Rather, the magmas from which the rock types crystallized had to have interacted to variable degrees with a late input of more primitive melt. The degree of this magma interaction was likely controlled by the geometry of the conduit and the location of emplacement given that Fe-Ti oxides in the oxide-rich rocks occur in pod-like bodies and exhibit no compositional evidence for magma mixing. Mirrored variations in magnetite compatible and incompatible elements in Fe-Ti oxides in the Footwall Zone, Main Zone, and W Horizon of the Marathon Cu-PGE deposit indicate that these zones could not have formed from a single, evolving magma, but rather multiple batches of compositionally distinct magmas. Fe-Ti oxides exhibit no compositional difference between those hosted by barren and mineralized rock. This is likely because sulfide liquated at depth in all of the magmas from which the Marathon Series crystallized. The composition of Fe-Ti oxides in the Eastern Gabbro fall outside of the compositional fields for Ni-Cu mineralization defined by Dupuis and Beaudoin (Mineral Deposita 46:319-335, 2011) and Ward et al. (J Geochem Explor 188:172-184, 2018) demonstrating that their discrimination diagrams can distinguish between Ni-rich and Ni-poor systems that contain disseminated and massive sulfides.
DS202102-0213
2021
Btaaleva, Y.V.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.
DS201412-0951
2014
Btschene, P.Vladykin, N.V., Btschene, P., Presser, J.L.B.Lamproitas de la porcion norte de la cordillera del Ybytytuzu, Paraguay oriental: YZU-6.6 Simposio Brasileiro de Geologia do Diamante, Aug. 3-7, 5p. AbstractSouth America, ParaguayLamproite
DS1992-0181
1992
Bubnov, V.M.Bubnov, V.M., Shaporev, V.A.Technique of mapping by near-field electromagnetic sounding on the SiberianPlatformRussian Geology and Geophysics, Vol. 33, No. 4, pp. 112-116RussiaGeophysics -electromagnetic
DS200612-0188
2006
Bubuska, V.Bubuska, V., Plomerova, J.European mantle lithosphere assembled from rigid microplates with inherited seismic anisotropy.Physics of the Earth and Planetary Interiors, In press - availableEuropeGeophysics - seismics, Baltic Shield
DS202104-0569
2021
Buccione, R.Buccione, R., Kechiched, R., Mongelli, G., Sinisi, R.REEs in the North Africa P-bearing deposits, paleoenvironments, and economic perspectives: a review.MDPI Minerals, Vol. 11, 27p. PdfAfrica, Algeria, Tunisia, MoroccoREE

Abstract: A review of the compositional features of Tunisia, Algeria, and Morocco phosphorites is proposed in order to assess and compare the paleoenvironmental conditions that promoted the deposit formation as well as provide information about their economic perspective in light of growing worldwide demand. Since these deposits share a very similar chemical and mineralogical composition, the attention was focused on the geochemistry of rare earth elements (REEs) and mostly on ?REEs, Ce and Eu anomalies, and (La/Yb) and (La/Gd) normalized ratios. The REEs distributions reveal several differences between deposits from different locations, suggesting mostly that the Tunisian and Algerian phosphorites probably were part of the same depositional system. There, sub-reducing to sub-oxic conditions and a major REEs adsorption by early diagenesis were recorded. Conversely, in the Moroccan basins, sub-oxic to oxic environments and a minor diagenetic alteration occurred, which was likely due to a different seawater supply. Moreover, the drastic environmental changes associated to the Paleocene-Eocene Thermal Maximum event probably influenced the composition of Northern African phosphorites that accumulated the highest REEs amounts during that span of time. Based on the REEs concentrations, and considering the outlook coefficient of REE composition (Koutl) and the percentage of critical elements in ?REEs (REEdef), the studied deposits can be considered as promising to highly promising REE ores and could represent a profitable alternative source for critical REEs.
DS1996-0184
1996
Buch, M.W.Buch, M.W., Rose, D.Mineralogy and geochemistry of the sediments of the Etosha Pan region In northern Namibia: a reconstructionJournal of African Earth Sciences, Vol. 22, No. 3, April 1, pp. 355-NamibiaGeochemistry -depositional environment, Etosha Pan area
DS1994-0223
1994
Bucham, K.L.Bucham, K.L., Mortensen, J.K., Card, K.D.Integrated paleomagnetic and uranium-lead (U-Pb) geochronologic studies of mafic intrusions in southern Canadian shield...Precambrian Research, Vol. 69, pp. 1-10.Canada, OntarioSuperior Province, Proterozoic polar wander path
DS200712-0154
2007
Buchan, C.Cawood, P.A.,Buchan, C.Linking accretionary orogenesis with supercontinent assembly.Earth Science Reviews, In press availableMantleAccretion
DS200712-0155
2007
Buchan, C.Cawood, P.A., Buchan, C.Linking accretionary orogenesis with supercontinent assembly.Earth Science Reviews, Vol. 82, 3-4, pp. 217-256.Mantle, GondwanaAccretion
DS200712-1046
2007
Buchan, C.Strachan, R.A., Collins, A.S., Buchan, C., Nance, R.D., Murphy, J.C., DLemos, R.S.Terrane analysis along a neoproterozoic active margin of Gondwana: insights from U Pb zircon geochronology.Journal of the Geological Society, Vol. 164, 1, pp. 57-60.MantleGeochronology
DS2003-0858
2003
Buchan, K.Macouin, M., Valet, J.P., Besse, J., Buchan, K., Ernst, R., Le Goff, M., ScharerLow paleointensities recorded in 1 to 2.4. Ga Proterozoic dykes, Superior ProvinceEarth and Planetary Science Letters, Vol. 213, 1-2, pp. 79-95.Ontario, ManitobaGeochronology
DS200412-1193
2003
Buchan, K.Macouin, M., Valet, J.P., Besse, J., Buchan, K., Ernst, R., Le Goff, M., Scharer, U.Low paleointensities recorded in 1 to 2.4. Ga Proterozoic dykes, Superior Province, Canada.Earth and Planetary Science Letters, Vol. 213, 1-2, pp. 79-95.Canada, Ontario, ManitobaGeochronology
DS1985-0092
1985
Buchan, K.L.Buchan, K.L., Baragar, W.R.A.Paleomagnetism of the Komatiitic Basalts of the Ottawa Islands, Northwest TerritoriesCanadian Journal of Earth Sciences, Vol. 22, pp. 553-66.Northwest Territories, Ottawa IslandsGeophysics - Magnetics
DS1985-0590
1985
Buchan, K.L.Schawrz, E.J., Buchan, K.L.Post Aphebian uplift deduced from remanent magnetization, Yellowknife Area of Slave Province.Canadian Journal of Earth Sciences, Vol. 22, pp. 1793-1802.Northwest TerritoriesTectonics
DS1989-0190
1989
Buchan, K.L.Buchan, K.L., Card, K.D., Chandler, F.W.Multiple ages of Nipissing diabase intrusion: paleomagnetic evidence From the Englehart area, OntarioCanadian Journal of Earth Sciences, Vol. 26, No. 3, March pp. 427-445OntarioHuronian, diorite, Paleomagnetics
DS1990-0248
1990
Buchan, K.L.Buchan, K.L., et al.Relative age of Otto stock and Matachewan dikes from paleomagnetism And implications for Precambrian polarCanadian Journal of Earth Sciences, Vol. 27, pp. 915-22.OntarioPolar wander path, Diabase dike, Geochronology
DS1990-0687
1990
Buchan, K.L.Hester, B.W., Buchan, K.L., Card, K.D., Chandler, F.W.Multiple ages of Nipissing diabase intrusion: paleo-magnetic evidence from the Englehart area, Ontario:discussionCanadian Journal of Earth Sciences, Vol. 7, No. 1, January pp. 159-161OntarioGeophysics -paleomagnetics, Diabase-Nipissing
DS1992-0182
1992
Buchan, K.L.Buchan, K.L., Mortensen, J.K., Card, K.D.Collaborative study of paleomagnetism and uranium-lead (U-Pb) (U-Pb) geochronology: key to reliable apparent Polar Wander Paths in the PrecambrianEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p. 92GlobalPaleomagnetics, Geochronology
DS1993-0173
1993
Buchan, K.L.Buchan, K.L., Mortensen, J.K., Card, K.D.Northeast-trending Early Proterozoic dykes of southern Superior Province:Canadian Journal of Earth Sciences, Vol. 30, No. 6, June pp. 1286-1296OntarioDikes, Paleomagnetics
DS1993-0419
1993
Buchan, K.L.Ernst, R.E., Buchan, K.L.Paleomagnetism of the Abitibi dyke swarms, southern Superior Province, And implications for the Logan LoopCanadian Journal of Earth Sciences, Vol. 30, No. 9, September pp. 1886-1897OntarioPaleomagnetics, Abitibi dike swarm
DS1994-0224
1994
Buchan, K.L.Buchan, K.L., Mortensen, J.K., Card, K.D.Technique of integrated paleomagnetism and uranium-lead (U-Pb) (U-Pb) geochronology of diabase dyke swarms applied to Superior Province.Geological Association of Canada (GAC) Abstract Volume, Vol. 19, p.OntarioDiabase dykes, Geochronology
DS1995-0224
1995
Buchan, K.L.Buchan, K.L., Mortensen, J.K., et al.Establishing key paleopoles for Superior and Slave cratons: potential for paleo Proterozoic reconstructionsGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) Annual Meeting Abstracts, Vol. 20, p. A12 AbstractOntario, Northwest TerritoriesCraton, Paleomagnetics
DS1995-0508
1995
Buchan, K.L.Ernst, R.E., Buchan, K.L., Palmer, H.C.The global mafic dyke GIS database: a tool for reconstructing paleo continents -mapping mantle plumesGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) Annual Meeting Abstracts, Vol. 20, p. A29 AbstractCanada, Northwest TerritoriesMantle plumes, Dyke swarms
DS1995-0509
1995
Buchan, K.L.Ernst, R.E., Buchan, K.L., Palmer, H.C.Giant dyke swarms: characteristics, distribution and geotectonic applications.Baer, Heiman, Physics and Chemistry of Dykes, pp. 3-21.GlobalDike swarms, Tectonics
DS1995-1076
1995
Buchan, K.L.LeCheminant, A.N., Van Breemen, O., Buchan, K.L.Proterozoic dyke swarms Lac de Gras Aylmer Lake area: regional distribution ages and PaleomagnetismGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) Annual Meeting Abstracts, Vol. 20, p. A57 AbstractNorthwest TerritoriesPaleomagnetics, Dyke swarms
DS1995-1434
1995
Buchan, K.L.Park, J.K., Buchan, K.L., Harlan, S.S.A proposed giant radiating dyke swarm fragmented by the separation of Laurentia and Australia -PaleomagnetismEarth and Planetary Science Letters, Vol. 132, pp. 129-39Canada, Wyoming, AustraliaDike swarm, Plume source, Paleomagnetics
DS1996-0185
1996
Buchan, K.L.Buchan, K.L., Halls, H.C., Mortensen, J.K.Paleomagnetism uranium-lead (U-Pb) (U-Pb) geochronology, geochemistry of Marathon dykes, SuperiorProvince... Fort Frances swarmCanadian Journal of Earth Sciences, Vol. 33, No. 12, Dec. pp. 1583-95.OntarioDike swarm, Marathon, Frances
DS1996-0435
1996
Buchan, K.L.Ernst, R.E, Buchan, K.L., West, T.D., Palmer, H.C.Diabase dolerite dyke swarms of the world... first editionGeological Survey of Canada Open File, No. 3241, 104p. map 1: 35, 000, 000 total 40.00GlobalDike swarms
DS1996-0437
1996
Buchan, K.L.Ernst, R.E., Buchan, K.L., West, T.D., Palmer, H.C.Diabase ( dolerite) dyke swarms of the worldGeological Survey of Canada (GSC) Open File, No. 3241, 104p.GlobalDike swarms
DS1997-0138
1997
Buchan, K.L.Buchan, K.L., Ernst, R.E., West, T.D.Diabase dyke swarms of Canada and their geotectonic applicationsGeological Survey of Canada Forum 1997 abstracts, p. 8. AbstractAlberta, SaskatchewanDike swarms
DS1997-0322
1997
Buchan, K.L.Ernst, R.E., Buchan, K.L.Giant radiating dyke swarms: their use in identifying Pre-Mesozoic large igneous provinces and mantle plumesAmerican Geophysical Union (AGU), Monograph, 100, pp. 297-333.QuebecDike swarms, James Bay Lowlands, Ashuanipi regions
DS1997-0323
1997
Buchan, K.L.Ernst, R.E., Buchan, K.L.Layered mafic intrusions: a model for their feeder systems and relationship with giant dyke swarms ...South African Journal of Geology, Vol. 100, 4, Dec. pp. 319-334South Africa, Swaziland, India, Zimbabwe, AustraliaMantle plume centres, Giant dyke swarms
DS1998-0177
1998
Buchan, K.L.Buchan, K.L., Mortensen, J.K., Card, K.D., Percival, J.Paleomagnetism and uranium-lead (U-Pb) geochronology of diabase dyke swarms of Minto Block Superior Province, Quebec.Canadian Journal of Earth Sciences, Vol. 35, No. 9, Sept. pp. 1954-69.QuebecDike swarms, Minto Block
DS2000-0275
2000
Buchan, K.L.Ernst, R.E., Buchan, K.L.The importance of mantle plumes in breakup and assembly events of the Canadian shield.Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000 Conference, 3p. abstract.Ontario, Quebec, ManitobaPaleocontinental reconstructions, rifting, Plume events
DS2000-0276
2000
Buchan, K.L.Ernst, R.E., Buchan, K.L., Hamilton, Okrugin, TomshinIntegrated paleomagnetism and uranium-lead (U-Pb) geochronology of mafic dikes of Eastern Anabar Shield Region: LaurentiaJournal of Geology, Vol. 108, pp. 381-401.Russia, SiberiaMesoproterozoic paleolatitude comparison Laurentia, Geophysics - magnetics
DS2001-0140
2001
Buchan, K.L.Buchan, K.L., Ernst, Hamilton, Mertanen, Pesonen, ElmingRodinia: the evidence from integrated paleomagnetism and uranium-lead (U-Pb) geochronologyPrecambrian Research, Vol. 110, pp. 9-32.GlobalGeochronology
DS2001-0301
2001
Buchan, K.L.Ernst, R.E., Buchan, K.L.Mantle plumes : their identification through timeGeological Society America Special Paper, Special Paper 352, 598p. $ 140.00GlobalBook, Mantle plumes
DS2001-0302
2001
Buchan, K.L.Ernst, R.E., Buchan, K.L.Large mafic magmatic events through time and links to mantle plume headsGeological Society of America, Special Paper, Special Paper. 352, pp. 483-576.MantlePlumes, Magmatism
DS2001-0303
2001
Buchan, K.L.Ernst, R.K., Buchan, K.L.The use of mafic dike swarms in identifying and locating mantle plumesGeological Society of America, Special Paper, Special Paper. 352, pp. 247-66.MantlePlumes, Dike swarms
DS2002-0435
2002
Buchan, K.L.Ernst, R.E., Buchan, K.L.Erratum to Maximum size and distribution in time and space of mantle plumesJournal of Geodynamics, Vol. 34, No. 5. pp.MantlePlumes
DS2002-0436
2002
Buchan, K.L.Ernst, R.E., Buchan, K.L.Maximum size and distribution in time and space of mantle plumes: evidence from large igneous provinces.Journal of Geodynamics, Vol. 34, 2, pp. 309-42.MantleTectonics
DS2002-0437
2002
Buchan, K.L.Ernst, R.E.,Buchan, K.L.Maximum size and distribution in time and space for mantle plumes; evidence from large igneous provinces.Journal of Geodynamics, Vol.34,2, Sept. pp. 309-42.MantleHot spots, plumes, Magmatism - review
DS2003-0175
2003
Buchan, K.L.Buchan, K.L., Harris, B.A., Ernst, R.E., Hanes, J.A.Ar Ar dating of the Pickle Crow diabase dyke system in the western Superior CratonGeological Association of Canada Annual Meeting, Abstract onlyManitobaGeochronology
DS200412-0232
2003
Buchan, K.L.Buchan, K.L., Ernst, R.E.Diabase dyke swarms and related units in Canada and adjacent units.Geological Survey of Canada Open File, No. 2022A, 1 map 1: 5,000,000 $ 25.Canada, Northwest Territories, Ontario, ManitobaMap - dike
DS200412-0233
2003
Buchan, K.L.Buchan, K.L., Harris, B.A., Ernst, R.E., Hanes, J.A.Ar Ar dating of the Pickle Crow diabase dyke system in the western Superior Craton of the Canadian Shield of Ontario and implicaGeological Association of Canada Annual Meeting, Abstract onlyCanada, ManitobaGeochronology
DS200512-0267
2004
Buchan, K.L.Ernst, R.E., Buchan, K.L.Large igneous provinces (LIPS) in Canada and adjacent regions: 3 Ga to present.Geoscience Canada, Vol. 31, 3, Sept. pp. 103-126.Canada, Northwest Territories, Alberta, Saskatchewan, OntarioDetailed descriptions and refs, geochronology
DS200512-0268
2005
Buchan, K.L.Ernst, R.E., Buchan, K.L.The global large igneous province (LIP) Atlas project.GAC Annual Meeting Halifax May 15-19, Abstract 1p.Magmatism
DS200512-0269
2005
Buchan, K.L.Ernst, R.E., Buchan, K.L., Campbell, I.H.Frontiers in large igneous province research.Lithos, Vol. 79, 3-4, pp. 271-297.Igneous provinces ( not specific to diamonds)
DS200512-0270
2005
Buchan, K.L.Ernst, R.E., Buchan, K.L., Hart, T.R., Morgan, J.North trending diabase dykes west of the Nipigon embayment: paleomagnetism, geochemistry and correlation with known magmatic events.GAC Annual Meeting Halifax May 15-19, Abstract 1p.Canada, OntarioEmpey Lake dyke swarm, Mine Centre, magmatism
DS200712-0120
2007
Buchan, K.L.Buchan, K.L., Goutier, J., Hamilton, M.A., Ernst, R.E., Matthews, W.A.Paleomagnetism, U Pb geochronology and geochemistry of Lac Esprit and other dyke swarms, James Bay area, Quebec: implications for Paleoproterozoic deformationCanadian Journal of Earth Sciences, Vol. 44, 5, pp. 643-664.Canada, QuebecDyke swarms
DS200912-0079
2009
Buchan, K.L.Buchan, K.L., LeCheminant, A.N., Van Breeman, O.Paleomagnetism and UPb geochronology of the Lac de Gras diabase dyke swarm, Slave Province, Canada: implications for relative drift of Slave and SuperiorCanadian Journal of Earth Sciences, Vol. 46, 5, May pp.361-379.Canada, Northwest TerritoriesPaleproterozoic
DS200912-0080
2009
Buchan, K.L.Buchan, K.L., LeCheminant, A.N., Van Breemen, O.Paleomagnetism and U-Pb geochronology of the Lac de Gras diabase dyke swarm, Slave Province Canada: implications for relative drift of Slave and Superior provinces in the Paleoproterozoic.Canadian Journal of Earth Sciences, Vol. 46, pp. 361-379.Canada, Northwest TerritoriesGeophysics
DS201012-0077
2010
Buchan, K.L.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
DS201012-0511
2010
Buchan, K.L.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
DS201312-0105
2014
Buchan, K.L.Buchan, K.L.Key paleomagnetic poles and their use in Proterozoic continent and supercontinent reconstructions: a review.Precambrian Research, Vol. 244, pp. 5-22.GlobalGondwanaland
DS201603-0383
2016
Buchan, K.L.Hamilton, M.A., Buchan, K.L.A 2169 Ma U-Pb baddeleyite age for the Otish gabbro, Quebec: implications for correlation of Proterozoic magmatic events and sedimentary seuences in the eastern Superior province.Canadian Journal of Earth Sciences, Vol. 53, 2, pp. 119-128.Canada, QuebecGeochronology
DS201607-1295
2016
Buchan, K.L.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.
DS201612-2298
2016
Buchan, K.L.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
DS201805-0938
2018
Buchan, K.L.Buchan, K.L., Ernst, R.E.A giant circumferential dyke swarm associated with the High Arctic Large Igneous Province ( HALIP).Gondwana Research, Vol. 58, pp. 39-57.Canada, Greenlanddykes

Abstract: n this study, we identify a giant circumferential mafic dyke swarm associated with the 135-75 Ma High Arctic Large Igneous Province (HALIP). Previously, a HALIP giant radiating mafic dyke swarm, with portions scattered across the Canadian high Arctic islands, northern Greenland, Svalbard and Franz Josef Land, was recognized in a pre-drift plate tectonic reconstruction of the Arctic region. The radiating swarm has been interpreted to focus above a mantle plume responsible for HALIP magmatism. The newly-recognized HALIP giant circumferential swarm has a centre that is near the focus of the HALIP radiating system, and hence, is likely related to the HALIP plume. Elements of the circumferential swarm are located in each of the four regions where the radiating system is found. The circumferential swarm has a quasi-circular or slightly elliptical geometry, an outer diameter of ~1600 km and an arc of ~220°. It is one of the largest giant circumferential dyke swarms recognized on Earth, and could be linked to the outer edge of the flattening plume head. It is also the first such swarm to have been identified by means of a plate tectonic reconstruction. Although giant circumferential dyke swarms appear to be relatively rare on Earth, possible analogues are common on Venus and are also found on Mars. On Venus giant circular or elliptical tectono-magmatic features, termed coronae, are characterized by an annulus of graben or fissures and prominent topography. Some coronae include a radiating graben-fissure system. Both radiating and circumferential graben may be underlain by dykes. If so, coronae could be analogues for terrestrial giant circumferential dyke swarms such as observed in the case of the HALIP.
DS201908-1776
2019
Buchan, K.L.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.
DS202002-0169
2019
Buchan, K.L.Buchan, K.L., Ernst, R.E.Giant circumferential dyke swarms: catalogue and characteristics.Dyke Swarms of the World: a modern perspective. Ed. Srivastava Springer, 49p. PdfMantledyke swarms

Abstract: Giant circumferential dyke swarms have a primary geometry that is quasi-circular or quasi-elliptical. Examples and possible examples described previously or identified in this study have outer diameters that range from ~450 to ~2500 km. There has been little study of these features. Here, we present a global catalogue of giant circumferential dyke swarms and discuss their characteristics. All of the identified giant circumferential swarms are of mafic composition. Many, but not all, are associated with a roughly coeval giant radiating dyke swarm whose focus is at or near the centre of the circumferential system. As giant radiating swarms are usually interpreted to focus above mantle plume centres and form a key component of the plumbing system of large igneous provinces (LIPs), it is likely that giant circumferential swarms linked to radiating systems are also plume and LIP related. The largest giant circumferential swarms have diameters comparable to the diameters postulated for the flattened heads of plumes that have risen from the core-mantle boundary, suggesting that they may be associated with the outer edge of a flattening or flattened mantle plume head. Smaller giant circumferential swarms could be linked with small plumes from the mid-mantle or with the edge of a magmatic underplate above a plume head. Giant circumferential dyke swarms on Earth may be analogues of coronae on Venus and similar features on Mars. Coronae are large tectono-magmatic features that typically consist of a quasi-circular or quasi-elliptical graben-fissure system and associated topography (central uplift or depression, and circular rim or moat). In some instances, they are linked to a giant radiating graben-fissure system and LIP-scale volcanism. Both radiating and circumferential graben on Venus and Mars have been interpreted to be underlain by dykes.
DS1992-0183
1992
Buchan, R.Buchan, R., Davison, J.G.Extraction/identification of microdiamonds in exploration samplesProspectors and Developers Association of Canada (PDAC) Conference preprint held March 30, April 1, 1992, 8pGlobalMineral processing, Microdiamonds
DS2003-0385
2003
Buchan, R.L.Ernst, R.E., Buchan, R.L.Recognizing mantle plumes in the geological recordAnnual Review of Earth and Planetary Sciences, Vol. 31, pp.MantleReview - plumes
DS200412-0523
2003
Buchan, R.L.Ernst, R.E., Buchan, R.L.Recognizing mantle plumes in the geological record.Annual Review of Earth and Planetary Sciences, Vol. 31, pp.469-523.MantleReview - plumes
DS1989-0321
1989
Buchanan, M.J.Dagbert, M., Buchanan, M.J., Duplessis, C.Evaluating industrial minerals deposits- Microcomputers can helpThe Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Annual Meeting Preprint, Outline of slide comments only, 8p. Database # 18040GlobalComputer, Program -slide comments only
DS1996-0186
1996
Buchanan, P.G.Buchanan, P.G., Nieuwland, D.A.Modern Developments in structural interpretation, validation andmodellingGeological Society of London Publ, No. 99, 370p. approx. $ 140.00GlobalBook - table of contents, Structure, palinspastic, geometry, faults, remote sense
DS1859-0028
1819
Buchanan-Hamilton, F.Buchanan-Hamilton, F.Description of the Diamond Mines of PannaEdinburgh Philosphical Journal, Vol. 1, PP. 49-54.IndiaDiamond Occurrences
DS1859-0030
1820
Buchanan-Hamilton, F.Buchanan-Hamilton, F.New Account of the East IndiesLondon:, IndiaDiamond Occurrence
DS1996-0438
1996
Buchanm, K.L.Ernst, R.E., Buchanm, K.L., West, . T.D., Palmer, H.C.Diabase dolerite dike swams of the world: first editionGeological Survey of Canada, Open file 3241, $ 40.00 report - map same priceGlobalDyke swarms, Report and map
DS201412-0334
2014
Buchar, A.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
DS1985-0485
1985
Buchardt, B.Neilsen, T.F.D., Buchardt, B.Strontium carbon oxygen isotopes in nephelinitic rocks and carbonatites Gardnar complex, Tertiary of east GreenlandChemical Geology, Vol. 53, No. 3-4, pp. 207-217GreenlandGeochronology, Carbonatite
DS1985-0493
1985
Buchardt, B.Nielsen, T.F.D., Buchardt, B.Strontium, Carbon,and Oxygen isotopes in nephelinitic rocks and carbonatites, Gardiner Tertiary of East GreenlandChemical Geology, Vol. 53, No. 3-4, December 30, pp. 207-218GreenlandCarbonatite
DS1991-0896
1991
Buchardt, B.Knudsen, C., Buchardt, B.Carbon and oxygen isotope composition of carbonates from the Qaqarssuk carbonatite complex, southern west GreenlandChemical Geology, Vol. 86, pp. 263-274GreenlandCarbonatite, Geochronology
DS1988-0280
1988
Buchbinder, G.G.R.Haddon, R.A.W., Buchbinder, G.G.R.Seismic wave scattering and the earth's structure in the lower mantleAmerican Geophysical Union (AGU) Monograph, Structure and dynmaics of earth's deep interior, No. 46, Conference Information 19th. IUGG, pp. 65-71GlobalMantle, Geophysics -seismics
DS202104-0584
2021
Buche, S.Krzemnicki, M.S., Wang, H.O., Buche, S.A new type of emerald from Afghanistan's Panjshir Valley.Journal of Gemmology, Vol. 37, 5, pp. 474-495.Asia, Afghanistanemerald

Abstract: Since 2017, a new type of emerald from the Panjshir Valley, Afghanistan, has entered the gem trade. This material is commonly of excellent quality and compares with the finest emeralds from Colombia, not only visually, but also with respect to inclusions, spectral features and chemical composition. As a result, some of these stones have entered the market as Colombian emeralds. This study presents detailed microscopic, spectral and trace-element data for these recently produced Afghan emeralds and compares them to ‘classic’ emeralds from the Panjshir Valley and from Laghman Province in Afghanistan. The samples from each of the three Afghan occurrences showed differences in their UV-Vis-NIR spectra and water-related features in their Raman spectra, and they could also be distinguished from one another-as well as those from other important emerald deposits worldwide- by their trace-element composition. A distinctly higher Fe concentration is the main criterion that separates the recent Panjshir production from Colombian emeralds. This study further shows that it is possible to clearly differentiate emeralds from different localities based on trace-element data using t-SNE statistical processing, which is an unsupervised machine-learning method.
DS202010-1855
2019
Buchel, G.Lange, V.T., Lorenz, V., Koppen, K-H, Buchel, G.New aspects of the volcanism of the West Eifel. *** GERJber. Mitt. oberrhein. Geol. Ver. N.F. English abstract, Vol. 101, pp. 227-250. 24p. PdfEurope, Germany guidebook
DS202010-1860
2020
Buchel, G.Lorenz, V., Lange, T., Buchel, G.The volcanoes of the Westeifel, Germany. ***GERJber. Mitt. oberrhein. Geol. Ver. N.F. English abstract, Vol. 102, pp. 379-411. 33p. PdfEurope, Germanymaars
DS201809-2003
2018
Buchen, J.Buchen, J., Marquardt, H., Speziale, S., Kawazoe, T., Ballaran, T.B., Kumosov, A.High pressure single crystal elasticity of wadlsleyite and the seismic signature of water on the shallow transition zone.Earth and Planetary Science Letters, Vol. 498, pp. 77-87.Mantlegeophysics - seismic

Abstract: Earth's transition zone at depths between 410 km and 660 km plays a key role in Earth's deep water cycle since large amounts of hydrogen can be stored in the nominally anhydrous minerals wadsleyite and ringwoodite, . Previous mineral physics experiments on iron-free wadsleyite proposed low seismic velocities as an indicative feature for hydration in the transition zone. Here we report simultaneous sound wave velocity and density measurements on iron-bearing wadsleyite single crystals with 0.24 wt-% . By comparison with earlier studies, we show that pressure suppresses the velocity reduction caused by higher degrees of hydration in iron-bearing wadsleyite, ultimately leading to a velocity cross-over for both P-waves and S-waves. Modeling based on our experimental results shows that wave speed variations within the transition zone as well as velocity jumps at the 410-km seismic discontinuity, both of which have been used in previous work to detect mantle hydration, are poor water sensors. Instead, the impedance contrast across the 410-km seismic discontinuity that is reduced in the presence of water can serve as a more robust indicator for hydrated parts of the transition zone.
DS202204-0523
2022
Buchen, J.Immoor, J., Miyagi, L., Liermann, H-P., Speziale, S., Schulkze, K., Buchen, J., Kurnosov, A., Marquardt, H.Weak cubic CaSi0s perovskite in the Earth's mantle.Nature , Vol. 603, pp. 276-279. 10.1038/s41586-021-04378-2Mantleperovskite

Abstract: Cubic CaSiO3 perovskite is a major phase in subducted oceanic crust, where it forms at a depth of about 550 kilometres from majoritic garnet1,2,28. However, its rheological properties at temperatures and pressures typical of the lower mantle are poorly known. Here we measured the plastic strength of cubic CaSiO3 perovskite at pressure and temperature conditions typical for a subducting slab up to a depth of about 1,200 kilometres. In contrast to tetragonal CaSiO3, previously investigated at room temperature3,4, we find that cubic CaSiO3 perovskite is a comparably weak phase at the temperatures of the lower mantle. We find that its strength and viscosity are substantially lower than that of bridgmanite and ferropericlase, possibly making cubic CaSiO3 perovskite the weakest lower-mantle phase. Our findings suggest that cubic CaSiO3 perovskite governs the dynamics of subducting slabs. Weak CaSiO3 perovskite further provides a mechanism to separate subducted oceanic crust from the underlying mantle. Depending on the depth of the separation, basaltic crust could accumulate at the boundary between the upper and lower mantle, where cubic CaSiO3 perovskite may contribute to the seismically observed regions of low shear-wave velocities in the uppermost lower mantle5,6, or sink to the core-mantle boundary and explain the seismic anomalies associated with large low-shear-velocity provinces beneath Africa and the Pacific7-9.
DS202205-0689
2022
Buchen, J.Immoor, J., Miyagi, L., Liemann, H-P., Speciale, S., Schulze, K., Buchen, J., Kumosov, A., Marquardt, H.Weak cubic CaSiO3 perovskite in the Earth's mantle.Nature, Vol. 603, pp. 276-279.Mantlesubduction

Abstract: Cubic CaSiO3 perovskite is a major phase in subducted oceanic crust, where it forms at a depth of about 550?kilometres from majoritic garnet1,2,28. However, its rheological properties at temperatures and pressures typical of the lower mantle are poorly known. Here we measured the plastic strength of cubic CaSiO3 perovskite at pressure and temperature conditions typical for a subducting slab up to a depth of about 1,200?kilometres. In contrast to tetragonal CaSiO3, previously investigated at room temperature3,4, we find that cubic CaSiO3 perovskite is a comparably weak phase at the temperatures of the lower mantle. We find that its strength and viscosity are substantially lower than that of bridgmanite and ferropericlase, possibly making cubic CaSiO3 perovskite the weakest lower-mantle phase. Our findings suggest that cubic CaSiO3 perovskite governs the dynamics of subducting slabs. Weak CaSiO3 perovskite further provides a mechanism to separate subducted oceanic crust from the underlying mantle. Depending on the depth of the separation, basaltic crust could accumulate at the boundary between the upper and lower mantle, where cubic CaSiO3 perovskite may contribute to the seismically observed regions of low shear-wave velocities in the uppermost lower mantle5,6, or sink to the core-mantle boundary and explain the seismic anomalies associated with large low-shear-velocity provinces beneath Africa and the Pacific.
DS1994-0225
1994
Bucher, K.Bucher, K., Frey, M.Petrogenesis of metamorphic rocks. Revised editionSpringer, 320pGlobalBook -table of contents, Petrogenesis -metamorphic rocks
DS1994-0555
1994
Bucher, K.Frost, R.B., Bucher, K.Is water responsible for geophysical anomalies in the deep continentalcrust? a petrological perspective.Tectonophysics, Vol. 231, pp. 293-309.MantleGeophysics -seismics, Petrology -water
DS1997-0735
1997
Bucher, K.Markl, G., Bucher, K.Proterozoic eclogites from the Lofiten Island, northern NorwayLithos, Vol. 42, No. 1-2, Dec. 1, pp. 15-36.NorwayEclogites
DS200612-1379
2005
Bucher, K.Stober, L., Bucher, K.The upper continental crust, an aquifer and its fluid: hydraulic and chemical dat a from 4 km depth in fractured crystalline basement rocks at the KTB test.Geofluids, Vol. 5, 1, pp. 8-19.Europe, GermanyGeochemistry
DS200812-0688
2008
Bucher, K.Lu, Z., Zhang, L., Du, J., Bucher, K.Coesite inclusions in garnet from eclogitic rocks in western Tianshan, northwest China: convincing proof of UHP metamorphism.American Mineralogist, Vol. 93, Nov-dec. pp. 1845-1850.ChinaEclogite
DS201112-0597
2011
Bucher, K.Li, X., Bucher, K.The Lillebukt alkaline complex, northern Norway.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p. 70-72.Europe, NorwayLillebukt
DS201112-0598
2011
Bucher, K.Li, X., Bucher, K.The Lillebukt alkaline complex, northern Norway.Peralk-Carb 2011... workshop June 16-18, Tubingen, Germany, Abstract p. 70-72.Europe, NorwayLillebukt
DS201507-0307
2015
Bucher, K.Bucher, K., Stober, I., Muller-Sigmund, H.Weathering crusts on peridotite.Contributions to Mineralogy and Petrology, Vol. 169, pp. 52-Europe, SpainDeposit - Ronda

Abstract: Chemical weathering of dark-green massive peridotite, including partly serpentinized peridotite, produces a distinct and remarkable brown weathering rind when exposed to the atmosphere long enough. The structure and mineral composition of crusts on rocks from the Ronda peridotite, Spain, have been studied in some detail. The generic overall weathering reaction serpentinized peridotite + rainwater = weathering rind + runoff water describes the crust-forming process. This hydration reaction depends on water supply from the outcrop surface to the reaction front separating green peridotite from the brown crust. The reaction pauses after drying and resumes at the front after wetting. The overall net reaction transforms olivine to serpentine in a volume-conserving replacement reaction. The crust formation can be viewed as secondary serpentinization of peridotite that has been strongly altered by primary hydrothermal serpentinization. The reaction stoichiometry of the crust-related serpentinization is preserved and reflected by the composition of runoff waters in the peridotite massif. The brown color of the rind is caused by amorphous Fe(III) hydroxide, a side product from the oxidation of Fe(II) released by the dissolution of fayalite component in olivine.
DS1997-0439
1997
Bucher, M.Gray, D.R., Foster, D.A., Bucher, M.Recognition and definition of orogenic events in the Lachlan Fold BeltAustralian Journal ofEarth Science, Vol. 44, No. 4, Aug. pp. 489-502AustraliaTectonics, orogeny, Lachlan Fold Belt, model
DS1930-0103
1932
Bucher, W.H.Bucher, W.H.Wells Creek Basin, Tennessee, a Typical Cryptovolcanic Structure.Geological Society of America (GSA) Bulletin., Vol. 43, No. 1, PP. 147-148.United States, Central States, Western TennesseeCryptoexplosion
DS1990-0249
1990
Bucher-Nurminen, K.Bucher-Nurminen, K.Geological phase diagram software- brief review of Thermocalc; PTX-system Geo-Calc and Geotab; Perplex and VertexTerra Nova, Vol. 2, pp. 401-410GlobalComputer, Programs -Thermocalc, PTX-system, Geo-calc, Geoteb, Perplex
DS1990-0250
1990
Bucher-Nurminen, K.Bucher-Nurminen, K.Transfer of mantle fluids to the lower continental crust: constraints from mantle mineralogy and MOHO temperatureChem. Geol, Vol. 83, No. 3/4, June 25, pp. 249-261GlobalMOHO, Mantle mineralogy
DS1993-0174
1993
Bucher-Nurminen, K.Bucher-Nurminen, K., Frey, M.Petrogenesis of metamorphic rocksSpringer Verlag, 300p. approx. $ 40.00GlobalMetamorphic rocks, Petrology, Book -ad
DS1960-0521
1965
Buchester, K.J.Buchester, K.J.The Australian Gem Hunter's GuideSydney: Ure Smith, 215P. ( GEMSTONES PP. 145-197.).AustraliaKimberlite, Kimberley, Occurrence
DS1991-1392
1991
Buchholz, S.Rabe, J.P., Buchholz, S.Commensurability and mobility in two dimensional molecular patterns ongraphiteScience, Vol. 253, July 26, pp. 424-427GlobalMineralogy, Graphite
DS200612-0189
2006
Buchko, I.V.Buchko, I.V., Salnikova, E.B., Kotov, A.B., Larin, A.M., Velikoslavinskii, Sorokin, Sorokin, YakovlevaPaleoproterozoic gabbro anorthosites of the Selenga Superterrane, southern framing of the Siberian Craton.Doklady Earth Sciences, Vol. 407, 3, pp. 372-375.Russia, SiberiaTectonics
DS200812-0151
2008
Buchko, I.V.Buchko, I.V., Sorokin, A.P., Yakoleva, S.Z., Plotkina, Y.V.Petrology of the Early Mesozoic ultramafic mafic Luchin a massif ( southeastern periphery of the Siberian Craton).Russian Geology and Geophysics, Vol. 49, 8, pp. 570-581.RussiaUltramafic rocks
DS2001-0998
2001
BuchlRyabichikov, I.D., Solovova, I.P., Ntaflos, Th., BuchlSubalkaline picrobasalts: melt inclusion chemistry, composition of primary magmas and P T regime -Geochemistry International, Vol. 39, No. 5, pp. 432-46.Russia, SiberiaSuperplume
DS2001-0997
2001
Buchl, A.Ryabichikov, I.D., Ntaflos, Th., Buchl, A., Solovena, I.Subalkaline picrobasalts and plateau basalts from the Putorana Plateau: mineral compositions and geochemistryGeochemistry International, Vol. 39, No. 5, pp. 415-31.Russia, SiberiaContinental flood basalt province, Picrites
DS201112-0534
2011
Buchl, A.Konig, S., Munker, C., Hohl, S., Paulick, H., Barth, A.R., Lagos, M., Pfander, J., Buchl, A.The Earth's tungsten budget during mantle melting and crust formation.Geochimica et Cosmochimica Acta, Vol. 78, 8, pp. 2119-2136.MantleMelting - not specific to diamonds
DS201112-1103
2011
Bucholz, C.Wang, Z., Bucholz, C., Skinner, B., Shimizu, N., Eiler, J.Oxygen isotope constraints on the origin of high Cr garnets from kimberlites.Earth and Planetary Science Letters, Vol. 312, 3-4, pp. 337-347.TechnologyGeochronology
DS201312-0106
2013
Bucholz, C.E.Bucholz, C.E., Gaetani, G.A., Behn, M.D., Shimizu, N.Post entrapment modification of volatiles and oxygen fugacity in olivine hosted melt inclusions.Earth and Planetary Science Letters, Vol. 392, pp. 39-49.MantleMelting
DS201701-0027
2016
Buchs, D.M.Pilet, S., Abe, N., Rochat, L., Kaczmarek, M-A., Hirano. N., Machida, S., Buchs, D.M., Baumgartner, P.O., Muntener, O.Pre-subduction metasomatic enrichment of the oceanic lithosphere induced by plate flexure.Nature Geoscience, Vol. 9, pp. 898-903.MantleSubduction

Abstract: Oceanic lithospheric mantle is generally interpreted as depleted mantle residue after mid-ocean ridge basalt extraction. Several models have suggested that metasomatic processes can refertilize portions of the lithospheric mantle before subduction. Here, we report mantle xenocrysts and xenoliths in petit-spot lavas that provide direct evidence that the lower oceanic lithosphere is affected by metasomatic processes. We find a chemical similarity between clinopyroxene observed in petit-spot mantle xenoliths and clinopyroxene from melt-metasomatized garnet or spinel peridotites, which are sampled by kimberlites and intracontinental basalts respectively. We suggest that extensional stresses in oceanic lithosphere, such as plate bending in front of subduction zones, allow low-degree melts from the seismic low-velocity zone to percolate, interact and weaken the oceanic lithospheric mantle. Thus, metasomatism is not limited to mantle upwelling zones such as mid-ocean ridges or mantle plumes, but could be initiated by tectonic processes. Since plate flexure is a global mechanism in subduction zones, a significant portion of oceanic lithospheric mantle is likely to be metasomatized. Recycling of metasomatic domains into the convecting mantle is fundamental to understanding the generation of small-scale mantle isotopic and volatile heterogeneities sampled by oceanic island and mid-ocean ridge basalts.
DS1975-0253
1976
Buchwald, V.F.Buchwald, V.F.Handbook of Iron Meteorites: Their History, Distribution, Composition and Structure.University of California Press, Vol. 1, PP. 1-243; Vol. 2, PP. 244-820; Vol. 3, PP. 821-Southwest Africa, NamibiaMeteor Occurrences, Kimberley
DS2002-1341
2002
Buchwaldt, R.Ring, U., Kroner, A., Buchwaldt, R., Toulkeridis, T., Layer, P.W.Shear zone patterns and eclogite facies metamorphism in the Mozambique belt ofPrecambrian Research, Vol. 116, No.1-2, pp. 19-56.Malawi, East AfricaMetamorphism, Tectonics
DS2003-0176
2003
Buchwaldt, R.Buchwaldt, R.Geochemistry and petrology of a Miocene trachyte basanite suite from Mt. TsartananaGeological Society of America, Annual Meeting Nov. 2-5, Abstracts p.182.MadagascarBasanite
DS200412-0234
2003
Buchwaldt, R.Buchwaldt, R.Geochemistry and petrology of a Miocene trachyte basanite suite from Mt. Tsartanana, northern Madagascar.Geological Society of America, Annual Meeting Nov. 2-5, Abstracts p.182.Africa, MadagascarBasanites, Foidites
DS1991-0188
1991
Buck, W.R.Buck, W.R.Modes of continental lithospheric extensionJournal of Geophysical Research, Vol. 96, No. B12, November 10, pp. 20, 161-20, 178MantleTectonics, Rifting -experimental data
DS1993-0175
1993
Buck, W.R.Buck, W.R.Effect of lithospheric thickness on the formation of high and low angle normal faultsGeology, Vol. 21, No. 10, October pp. 933-936MantleStructure, Lithosphere
DS1993-0698
1993
Buck, W.R.Hopper, J.R., Buck, W.R.Decoupling of the crust and mantle: the effect of a weak lower crust onlithospheric deformationGeological Society of America Annual Abstract Volume, Vol. 25, No. 6, p. A197 abstract onlyChinaLithosphere, Mantle
DS1994-1955
1994
Buck, W.R.Wusi Su. Mutter, C.Z., Mutter, J.C., Buck, W.R.Some theoretical predictions on the relationships among spreading rate, mantle temperature and crustal thickness.Journal of Geophysical Research, Vol. 99, No. B 2, February 10, pp. 3215-3227.MantleExperimental petrology, Mantle flow
DS1998-0640
1998
Buck, W.R.Hopper, J.R., Buck, W.R.Styles of extensional decouplingGeology, Vol. 26, No. 8, Aug. pp. 699-702.MantleLithosphere, extension
DS201012-0054
2010
Buck, W.R.Bialas, R.W., Buck, W.R., Qin, R.How much magma is required to rift a continent?Earth and Planetary Science Letters, Vol. 292, 1-2, pp. 68-78.MantleMagmatism
DS1997-0139
1997
Buckenham, M.Buckenham, M.Native title in New ZealandAustralian Institute of Mining and Metallurgy (AusIMM) Bulletin, No. 6, Sept, pp. 55-56GlobalLegal, Native title - Aboriginal
DS1994-0451
1994
Buckingham, M.J.Dransfield, M.H., Buckingham, M.J., Van Kann, F.J.Lithological mapping by correlating magnetic and gravity gradient airbornemeasurementsExploration Geophysics, Australian Bulletin, Vol. 25, No. 1, March pp. 25-30GlobalGeophysics -gravity, Lithology
DS1992-0184
1992
Buckle, J.Buckle, J.Detection of kimberlite pipes in the Lac de Gras area with helicopter borne electromagnetics and magnetics #1Northwest Territories Geoscience Forum held November 25, 26th. 1992, AbstractNorthwest TerritoriesGeophysics, Kimberlites
DS1993-0176
1993
Buckle, J.Buckle, J.Detection of kimberlite pipes in the Lac de Gras area with helicopter borne electromagnetics and magnetics. #2World Diamond Conference held Oct '97, handout by Geoterrex, 14p.Northwest TerritoriesGeophysics - electromagnetics, Geophysics - magnetics
DS1993-0177
1993
Buckle, J.Buckle, J.The geophysical response of kimberlite pipesHaileybury Sch. Mines, Canadian Society of Exploration Geophysists, 32p.Northwest TerritoriesGeophysics - magnetics
DS1993-0178
1993
Buckle, J.Buckle, J.Detection of kimberlite pipes in the Lac de Gras area with helicopter borne Electromagnetic and Magnetics. #3Haileybury Sch. Mines, Canadian Society of Exploration Geophysists, 12p.Northwest TerritoriesGeophysics - magnetics, electromagnetic
DS1993-0179
1993
Buckle, J.Buckle, J.Detection of kimberlite pipes in the Lac de Gras area with helicopter-borne electromagnetic and magneticsPromotional Brochure, Handout From Two Day Seminar Held Vancouver, B.c. May, 16pNorthwest TerritoriesGeophysics -some applications, Dighem Company information
DS2002-0216
2002
Buckle, J.Buckle, J.The Wawa diamond enigmaC.i.m. Bulletin, Vol. 95, No. 1061, May, pp. 85-87.OntarioLamprophyres, Geochemistry, geology
DS1993-0180
1993
Buckle, J.E.Buckle, J.E., Chartier, T., Schiller, E.A.Discovery of the Yamba Lake, Northwest Territories, kimberlites with integrated geophysical and geochemical methods. #2Northwest Territories Exploration Overview for 1993, November pp. 25-26.Northwest TerritoriesGeophysics, Yamba Lake
DS1993-0181
1993
Buckle, J.E.Buckle, J.E., Chartier, T., Schiller, E.A.Discovery of the Yamba Lake, Northwest Territories, kimberlites with integrated geophysical and geochemical methods. #1Northwest Territories Geoscience Forum preprint, 16p.Northwest TerritoriesNews item, Tanqueray Exploration activity
DS1998-1220
1998
Buckley, A.Reed. S.J.B., Buckley, A.Rare earth element determination in minerals by electron probemicroanalysis: application of spectrum.Mineralogical Magazine, Vol. 62, 1, Feb. pp. 1-8GlobalGeochemistry - spectrum syntheis, rare earth elements (REE)
DS200712-0148
2007
Buckley, A.J.Carpenter, M.A., Darling, T.W., Buckley, A.J., Taylor, P.A.Investigation of eleastic and An elastic phenomena associated with structural pphase transition in perovskites by Resonant Ultrasound Spectroscopy.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p.188.MantlePerovskite
DS200712-0149
2007
Buckley, A.J.Carpenter, M.A., Darling, T.W., Buckley, A.J., Taylor, P.A.Investigation of eleastic and An elastic phenomena associated with structural pphase transition in perovskites by Resonant Ultrasound Spectroscopy.Frontiers in Mineral Sciences 2007, Joint Meeting of Mineralogical societies Held June 26-28, Cambridge, Abstract Volume p.188.MantlePerovskite
DS1975-0156
1975
Buckley, F.Paul, D.K., Nixon, P.H., Buckley, F.Kimberlite ChemistryLeeds University Research Institute of African Geology Annual Report, PP. 32-35.LesothoGeochemistry, Kao
DS1975-0377
1976
Buckley, F.Paul, D.K., Buckley, F., Nixon, P.H.Fluorine and Chlorine Geochemistry of KimberlitesChemical Geology, Vol. 17, No. 2, PP. 125-133.South Africa, India, GreenlandGeochemistry
DS1982-0470
1982
Buckley, F.Nixon, P.H., Thirwall, M.F., Buckley, F.Kimberlite-lamproite ConsanquinityProceedings of Third International Kimberlite Conference, TERRA COGNITA, ABSTRACT VOLUME., Vol. 2, No. 3, PP. 252-254, (abstract.).Spain, South Africa, AustraliaKimberlite, Petrography, Genesis
DS1982-0471
1982
Buckley, F.Nixon, P.H., Thirwall, M.F., Buckley, F., Scott-Smith, B.H.Kimberlite- Lamproite ConsanguinitySelection Trust In-house File., 8P.AustraliaGenesis
DS1984-0161
1984
Buckley, F.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
DS1984-0557
1984
Buckley, F.Nixon, P.H., Thirlwall, M.F., Buckley, F., Davies, C.J.Spanish and Western Australian Lamproites: Aspects of Whole rock Geochemistry.Proceedings of Third International Kimberlite Conference, Vol. 1, PP. 285-296.Spain, Australia, Western AustraliaMineral Chemistry, Rare Earth Elements (ree), Isotope, Big Spring
DS1990-0251
1990
Buckley, H.A.Buckley, H.A., Woolley, A.R.Carbonates of the magnesite-siderite series from four carbonatitecomplexesMineralogical Magazine, Vol. 54, September pp. 413-418GlobalCarbonatite, Magnesite-siderite
DS1993-1765
1993
Buckley, H.A.Woolley, A.R., Buckley, H.A.Magnesite siderite series carbonates in the Nkombwa and Newania carbonatitecomplexes.South African Journal of Geology, Vol. 96, No. 3, Sept. pp. 126-130.Zambia, IndiaCarbonatite, Nkombwa, Newania complex
DS1992-0185
1992
Buckley, R.Buckley, R.Critical environmental issues for the mining industry in 1992Australian Institute of Mining and Metallurgy (AusIMM) Bulletin, No. 4, July pp. 39-47AustraliaEnvironment, legal, Mining industry
DS201312-0107
2013
Buckley, S.J.Buckley, S.J., Kurz, T.H., Howell, J.A., Schneider, D.Terrestrial lidar and hyper spectral dat a fusion products for geological outcrop analysis. NOT specific to diamonds ( shale and carbonates)Computers & Geosciences, Vol. 54, pp. 249-258.United States, Europe, SpainLidar - interest
DS1991-1454
1991
Buckley, S.M.Root, S.I., Hoffee, R.L., Buckley, S.M., Hlavin, W.Details of basement tectonics, northeastern OhioGeological Society of America, Abstract Volume, Vol. 23, No. 3, March p. 57GlobalTectonics, Structure
DS1930-0019
1930
Buckley, W.Buckley, W.Big Game Hunting in Central AfricaLondon: Palmer., 268P.South Africa, ZimbabweKimberlite
DS200812-1247
2008
Bucknum, M.J.Wen, B., Zhao, J., Bucknum, M.J., Yao, P., Li, T.First principles studies of diamond polytypes.Diamond and Related Materials, Vol. 17, 3, pp. 356-364.TechnologyDiamond crystallography - simulation
DS200812-0836
2008
Buda, D.Pagot, E., Pesaresi, M., Buda, D., Ehrlich, D.Development of an object oriented classification model using very high resolution satellite imagery for monitoring diamond mining activity.International Journal of Remote Sensing, Vol. 29, 2, Jan. pp. 499-512.AfricaRemote sensing - mine
DS2000-0974
2000
BudaevVasilenko, V.B., Zinchuk Krasavchikov, Budaev, KuznetsCriteria for petrochemical identfication of kimberlitesRussian Geology and Geophysics, Vol.41,12,pp.1697-1709., Vol.41,12,pp.1697-1709.RussiaPetrology - classification
DS2000-0975
2000
BudaevVasilenko, V.B., Zinchuk Krasavchikov, Budaev, KuznetsCriteria for petrochemical identfication of kimberlitesRussian Geology and Geophysics, Vol.41,12,pp.1697-1709., Vol.41,12,pp.1697-1709.RussiaPetrology - classification
DS1998-0178
1998
Budaev, D.A.Budaev, D.A.Populational model of kimberlites: an application to diamondiferous kimberlite regions with geodynamics...7th International Kimberlite Conference Abstract, pp. 108-110.Russia, Yakutia, South Africa, West Africa, LesothoPetrochemistry, Kimberlite - composition
DS1998-0179
1998
Budaev, D.A.Budaev, D.A., Dolgunin, A.V., Fomin, A.S.An algorithm of kimberlite Diamondiferous estimations7th International Kimberlite Conference Abstract, pp. 111-12.Russia, YakutiaDiamond petrochemistry - Ti contnent, Deposit - Botuobinskaya
DS1987-0506
1987
Budahn, J.R.Neilson, J.E., Budahn, J.R., Wilshire, H.G.Fractionation of rare earth elements (REE) in a composite xenolith Dish Hill CaliforniaGeological Society of America, Vol. 19, No.6 MarchCaliforniaUSA, Dish Hill
DS1987-0521
1987
Budahn, J.R.Nielson-Pike, J.E., Budahn, J.R., Wilshire, H.G.Fluid wallrock interactions in the mantle; evidence from composite lherzolite hornblendite xenolithsUnited States Geological Survey (USGS) Circ.No. 956 Geophysics and petrology of the deep crust and upper, pp. 86-88GlobalXenoliths
DS2001-1207
2001
BudanovVolkova, N.I., Frenkel, Budanov, Kholodova, LepezinEclogites of the Maksyutov Complex, southern Urals: geochemistry and the nature of the Protolith.Geochemistry International, Vol. 39, No. 10, pp. 935-46.Russia, UralsEclogites
DS1975-0044
1975
Budanov, V.I.Budanova, K.T., Budanov, V.I.The Southwestern Pamirs, a New Province of Garnetiferous Ultramafic Rocks.Doklady Academy of Science USSR, Earth Science Section., Vol. 222, No. 1-6, PP. 190-193.RussiaKimberlite
DS1975-0044
1975
Budanova, K.T.Budanova, K.T., Budanov, V.I.The Southwestern Pamirs, a New Province of Garnetiferous Ultramafic Rocks.Doklady Academy of Science USSR, Earth Science Section., Vol. 222, No. 1-6, PP. 190-193.RussiaKimberlite
DS202009-1668
2020
Budde, G.Tappe, S., Budde, G., Stracke, A., Wilson, A., Kleine, T.The tungsten-182 record of kimberlites above the African superplume: exploring links to the core-mantle boundary. Ultradeep diamondsEarth and Planetary Science Letters, Vol. 547, 14p. PdfAfricaLLSVP, superplume

Abstract: Many volcanic hotspots are connected via ‘plume’ conduits to thermochemical structures with anomalously low seismic velocities at the core-mantle boundary. Basaltic lavas from some of these hotspots show anomalous daughter isotope abundances for the short-lived 129I-129Xe, 146Sm-142Nd, and 182Hf-182W radioactive decay systems, suggesting that their lower mantle sources contain material that dates back to Earth-forming events during the first 100 million years in solar system history. Survival of such ‘primordial’ remnants in Earth's mantle places important constraints on the evolution and inner workings of terrestrial planets. Here we report high-precision 182W/184W measurements for a large suite of kimberlite volcanic rocks from across the African tectonic plate, which for the past 250 million years has drifted over the most prominent thermochemical seismic anomaly at the core-mantle boundary. This so-called African LLSVP, or ‘large low shear-wave velocity province’, is widely suspected to store early Earth remnants and is implicated as the ultimate source of global Phanerozoic kimberlite magmatism. Our results show, however, that kimberlites from above the African LLSVP, including localities with lower mantle diamonds such as Letseng and Karowe Orapa A/K6, lack anomalous 182W signatures, with an average W value of 0.0 ± 4.1 (2SD) for the 18 occurrences studied. If kimberlites are indeed sourced from the African LLSVP or superplume, then the extensive 182W evidence suggests that primordial or core-equilibrated mantle materials, which may contribute resolvable W excesses or deficits, are only minor or locally concentrated components in the lowermost mantle, for example in the much smaller ‘ultra-low velocity zones’ or ULVZs. However, the lack of anomalous 182W may simply suggest that low-volume kimberlite magmas are not derived from hot lower mantle plumes. In this alternative scenario, kimberlite magmas originate from volatile-fluxed ambient convecting upper mantle domains beneath relatively thick and cold lithosphere from where previously ‘stranded’ lower mantle and transition zone diamonds can be plucked.
DS1993-0182
1993
Buddin, T.S.Buddin, T.S., Stimpson, I.G., Williams, G.D.North Chilean forearc tectonics and Cenozoic plate kinematicsTectonophysics, Vol. 220, No. 1-4, April 15, pp. 193-204Andes, ChileTectonics
DS1994-0226
1994
Budkewitsch, P.Budkewitsch, P., et al.Characterization and extraction of linear features from digital imagesCanadian Journal of Remote Sensing, Vol. 20, No. 3, Sept. pp. 268-279CanadaGIS, Structure -linears
DS1994-0227
1994
Budkewitsch, P.Budkewitsch, P., et al.Characterization and extraction of linear features from digital imagesCanadian Journal of Remote Sensing, Vol. 20, No. 3, Sept. pp. 268-279.CanadaRemote Sensing, Structure -linear features
DS1994-1023
1994
Budkewitsch, P.Legault, F., Francis, D., Hynes, A., Budkewitsch, P.Proterozoic continental volcanism in the Belcher Islands: implications For the evolution Circum UngavaCanadian Journal of Earth Sciences, Vol. 31, pp. 1536-49.Quebec, Ungava, Labrador, Belcher Islandsvolcanism., Fold Belt
DS1996-1541
1996
Budkewitsch, P.Wilkinson, L., Budkewitsch, P., Graham, D.F., HendersonAlternative methods of base map generation using remote sensing and GIS: a pilot study western Churchill ProvinceGeological Survey of Canada Current Research, No. 1997-C, pp. 81-90.Northwest TerritoriesRemote sensing, GIS
DS1997-1255
1997
Budkewitsch, P.Wilkinson, L., Budkewitsch, P., et al.GIS dat a integration and analysis for regional mapping and exploration In the Northwest Territories.Geological Survey of Canada Forum 1997 abstracts, p. 17. AbstractNorthwest TerritoriesGeophysics, GIS
DS2002-0831
2002
Budkewitsch, P.Kerr, D., Budkewitsch, P., Bryan, Knight, KjarsgaardSurficial geology, spectral reflectance characteristics, and their influence on hyperspectralGeological Survey of Canada Current Research, 2002-04, 8p.Northwest TerritoriesImaging - drift prospecting technique for kimberlite, Deposit - Diavik mine
DS200612-0536
2006
Budkewitsch, P.Harris, J.R., Ponomarev, P., Shang, S., Budkewitsch, P., Rogge, D.A comparison of automatic and supervised methods for extracting lithological end members from hyper spectral data: application to southern Baffin Island, Nunavut.Geological Survey of Canada Current Research, 2006-C4 19p.Canada, NunavutHyperspectral - technology
DS201012-0569
2010
BudulanPaulen, R.C., Adcock, S.W., Spirito, W.A., Chorlton, L.B., McClenaghan, M.B., Oviatt, Budulan, RobinsonsInnovative methods to search, download and display indicator mineral data: a new Tri-Territorial Indicator Mineral Database.38th. Geoscience Forum Northwest Territories, Abstract pp. 75-76.Canada, Northwest TerritoriesGEM database
DS1991-0189
1991
Buell, R.Buell, R.Kirkland Lake area diamond hunt stallsCan. Mining and Exploration News, October pp. 1., p. 14OntarioNews item, Lac minerals
DS201112-0123
2010
Bueono Sachs, L.L.Bueono Sachs, L.L., Silveira, F.V.Kimberlitos do estado do Piaui.5th Brasilian Symposium on Diamond Geology, Nov. 6-12, abstract p. 70-71.South America, Brazil, Minas GeraisOverview of area
DS1975-1041
1979
Buerger, A.D.Gunthorpe, R.J., Buerger, A.D.The Otjisazu Igneous Complex a Recently Identified Carbonatite Locality in Central Southwest Africa.Geo. Soc. Sth. Afr. 18th. Congr., Vol. 78, PT. 1, PP. 161-163.Southwest Africa, NamibiaCarbonatite, Related Rocks
DS1999-0098
1999
Buerki, P.R.Buerki, P.R., Reinitz, I.M., Mulhmeister, S., Elen, S.Observation of the H2 defect in gem quality type Ia diamondGems and Gemology, Precis of a paper, Vol. 35. summer, p. 172.GlobalDiamond - absorption
DS2000-0812
2000
Buerki, P.R.Reinitz, I.M., Buerki, P.R., Shigley, J.E., McClureIdentification of HPHT treated yellow to green diamonds. the saturated neon green colour is not only..Gems and Gemology, Vol. 36, No. 2, Summer, pp. 128-37.United States, Russia, SwedenDiamond - GE, Novatek, treated, colour
DS1970-0485
1972
Bufeev, Yu.V.Bufeev, Yu.V.Late Proterozoic Graben in West Africa and Its StructureGeotektonika., No. 2, PP. 61-66.West Africa, Guinea, Sierra Leone, GermanyStructure, Tectonics
DS1993-0773
1993
Bufeyev, Yu.V.Kaminsky, F.V., Kande, S., Keita, I., Nikitin, Yu.A., Bufeyev, Yu.V.Unusual spinellid variety of the hervynite-ulvospinel series from GuineaDoklady Academy of Sciences USSR, Earth Science Section, Vol. 317, No. 6, pp. 145-149GuineaBaule River Basin, Niger River, Gbenko alluvials
DS1990-0499
1990
Buffa, E.A.Fuller, H.K., Gunnells, G.B, Buffa, E.A., Orndorff, R.C.Geologic map index of Virginia, revised and updatedUnited States Geological Survey (USGS), 16p. text 6 sheets -freeGlobalMap, Index of published maps
DS2001-0180
2001
BuffetChemenda, A.I., Hurpin, D., Tang, Stephan, BuffetImpact of arc continent collision on the conditions of burial and exhumation of UHP LT rocks.... experimentalTectonophysics, Vol. 342, No. 2, pp. 137-61.GlobalUHP, Tectonics
DS201112-0124
2011
Buffett, B.Buffett, B.Dynamics and evolution of the Earth's core and lowermost mantle.Goldschmidt Conference 2011, abstract p.595.MantleGeodynamics
DS1992-0186
1992
Buffett, B.A.Buffett, B.A., Huppert, H.E., Lister, J.R., Woods, A.W.Analytical model for solidification of the earth's coreNature, Vol. 356, No. 6367, March 26, pp. 329-331MantleModel, Core
DS1996-0187
1996
Buffett, B.A.Buffett, B.A., Huppert, H.E., Lister, J.R., Woods, A.W.On the thermal evolution of the earth's coreJournal of Geophysical Research, Vol. 101, No. B4, April 10, pp. 7989-8006.MantleGeophysics, Paleomagnetics, Core mixing
DS1996-0188
1996
Buffett, B.A.Buffett, B.A., Huppert, H.E., Lister, J.R., Woods, A.W.On the thermal evolution of the earth's coreJournal of Geophysical Research, Vol. 101, No. B4, April 10, pp. 7989-8006MantleGeothermometry
DS2000-0117
2000
Buffett, B.A.Buffett, B.A.Earth' core and the geodynamoScience, Vol. 288, No. 5473, June 16, pp. 2007.MantleCore, Geodynamics
DS2001-0141
2001
Buffett, B.A.Buffett, B.A., Wenk, H.R.Texturing of the Earth's inner core by Maxwell stressesNature, Vol. 413, Sept. 6, pp. 60-63.MantleAnistropy
DS2002-0217
2002
Buffett, B.A.Buffett, B.A.Estimates of heat flow in the deep mantle based on the power requirements for the geodynamo.Geophysical Research Letters, Vol. 29, 12, June 15, DOI 10.1029/2001GLO14649.MantleHeat flow, geodynamics
DS200412-0376
2004
Buffett, B.A.Costin, S.O., Buffett, B.A.Preferred reversal paths caused by a heterogeneous conducting layer at the base of the mantle.Journal of Geophysical Research, Vol. 109, B6, B06101, June 9, 10.1029/2003 JB002853MantleGeophysics - seismics
DS200612-0190
2006
Buffett, B.A.Buffett, B.A.Plate force due to bending at subduction zones.Journal of Geophysical Research, Vol. 111, B9, B09405.MantleTectonics, subduction
DS200612-0191
2006
Buffett, B.A.Buffett, B.A., Rowley, D.B.Plate bending at subduction zones: consequences for the direction of plate motions.Earth and Planetary Science Letters, Vol. 245, 1-2, pp. 359-364.MantleSubduction
DS200612-0950
2005
Buffett, B.A.Mount, J.E., Buffett, B.A.Mechanisms of core mantle angular momentum exchange and the observed spectral properties of torsional oscillations.Journal of Geophysical Research, Vol. 110, B8, B08103, 10.1029/2004 JB003555MantleTectonics
DS200712-0121
2006
Buffett, B.A.Buffett, B.A.Plate force due to bending at subduction zones.Journal of Geophysical Research, Vol. 111, B9, B09405MantleSubduction
DS200812-0633
2008
Buffett, B.A.Lay, T., Hernlund, J., Buffett, B.A.Core mantle boundary heat flow.Nature Geoscience, Vol. 1, 1, pp. 25-32.MantleGeothermometry
DS201012-0078
2010
Buffett, B.A.Buffett, B.A., Seagle, C.T.Stratification of the top of the core due to chemical interactions with the mantle.Journal of Geophysical Research, Vol. 115, B4, B04407.MantleGeochemistry
DS201212-0094
2012
Buffett, B.A.Buffett, B.A., Becker, T.W.Bending stress and dissipation in subducted lithosphere.Journal of Geophysical Research, Vol. 117, B5, B05413MantleSubduction
DS2003-0177
2003
Buffett, E.A.Buffett, E.A.The thermal state of the Earth's coreScience, No. 5613, March 14, pp. 1675-76.MantleGeothermometry
DS200712-1152
2007
Buffett, G.White, D.J., Kjarsgaard, B.A., Mwenifumbo, C.J., Buffett, G.Seismic delineation of the Orion South 140/141 kimberlite, Fort a la Corne field, Saskatchewan.Proceedings of Exploration 07 edited by B. Milkereit, pp. 1159-1163.Canada, SaskatchewanGeophysics - seismics
DS1960-0802
1967
Buffler, R.T.Buffler, R.T.The Browns Peak Formation and its Relationship to the Late Tertiary Geologic History of the Elkhead Region, Northwestern Colorado and South Central Wyoming.Ph.d. Thesis, University California At Berkeley, 175P.United States, Colorado, Wyoming, Rocky MountainsDiatreme
DS1986-0114
1986
Buffler, R.T.Buffler, R.T., Rosenthal, D.B., et al.Continent ocean transect F-1 Ouachitas to YucatanGeological Society of America (GSA) Abstract Volume, Vol. 18, No. 6, p. 552. (abstract.)MidcontinentTectonics
DS2000-0087
2000
Bugaets, S.N.Bespaev, Kh.A., Bugaets, S.N.Comparative petrochemistry of ultrahigh pressure metamorphic rocksRussian Geology and Geophysics, Vol.41,12,pp.1654-61., Vol.41,12,pp.1654-61.GlobalUHP, Geochemistry
DS2000-0088
2000
Bugaets, S.N.Bespaev, Kh.A., Bugaets, S.N.Comparative petrochemistry of ultrahigh pressure metamorphic rocksRussian Geology and Geophysics, Vol.41,12,pp.1654-61., Vol.41,12,pp.1654-61.GlobalUHP, Geochemistry
DS1998-0180
1998
Bugelskii, Yu.Yu.Bugelskii, Yu.Yu., Patyk-Kara, N.G., Kamshilina, E.M.Geology of placers and weathering crust depositsGeology of Ore Deposits, Vol. 40, No. 3, May-June pp. 267-269/RussiaPlacers, alluvials, Gold
DS1995-0225
1995
Bugelskiy, Yu.Yu.Bugelskiy, Yu.Yu.The role of groundwater of shallow circulation in the formation of ore bearing weathering crustGeology of Ore Deposits, Vol. 37, No. 5, Sept-Oct., pp. 399-RussiaLaterites, Weathering
DS1994-0228
1994
Buhaenko, D.S.Buhaenko, D.S., et al.Cathodluminescence and electroluminescence in ion implanted type IIdiamonds.Diamond Relations, # NN160, Vol. 3, No. 4-6. April pp. 922-925.GlobalCVD.
DS1940-0093
1945
Buhlis, R.Buhlis, R.Arkansaw Diamonds. #2The Mineralogist (portland, Oregon), Vol. 13, No. 2, Feb. P. 46.United States, Gulf Coast, Arkansas, PennsylvaniaMineralogy
DS1995-0226
1995
Buhlmann, A.L.Buhlmann, A.L., Cavell, P.A., Burwash, R.A., et al.Nature and origin of phlogopite-clinopyroxenite inclusions in Eoceneminettes in Milk River area.Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) Annual Meeting Abstracts, Vol. 20, p. A12 AbstractAlbertaMinettes
DS1996-0189
1996
Buhlmann, A.L.Buhlmann, A.L.Eocene minettes and their mica clinopyroxenite inclusions in the Milk Riverarea, southern Alberta.University of Alberta, MSc. Thesis, 139p.AlbertaMinettes, Milk River area
DS2000-0118
2000
Buhlmann, A.L.Buhlmann, A.L., Cavell, P., Burwash, Creaser, LuthMinette bodies and cognate mica-clinopyroxenite xenoliths from Milk River area - complex historyCanadian Journal of Earth Sciences, Vol.37, No.11, Nov.pp.1629-50.Alberta, southern, MontanaArchean Wyoming Craton, Milk River area - minettes
DS1994-0229
1994
Buhmann, C.Buhmann, C.Parent material and pedogenic processes in South AfricaClay Minerals, Vol. 29, pp. 239-246South AfricaKaroo Supergroup, Sedimentology - not specific to diamonds
DS1994-0230
1994
Buhmann, C.Buhmann, C.Parent material and pedogenic processes in South AfricaClay Minerals, Vol. 29, pp. 239-246.South AfricaKaroo Supergroup, Sedimentology - not specific to diamonds
DS1994-0231
1994
Buhn, B.Buhn, B., et al.Tectonometamorphic patterns developed during Pan African continental collision in the Damara In land BeltChemie der Erde, Vol. 54, pp. 329-354.NamibiaTectonics, Damara Inland Belt
DS1994-0232
1994
Buhn, B.Buhn, B., Haussinger, H., Kramm, U., et al.Tectonometamorphic patterns developed during Pan-African continental collision in Damara In land BeltChemie der Erde, Vol. 54, pp. 329-354Namibiametamorphism, Orogeny -Pan African, Congo Craton, Tectonics
DS1999-0099
1999
Buhn, B.Buhn, B., Rankin, A.H.Geochemistry and ore forming potential of alkali and volatile rich carbonatite magmas.Stanley, SGA Fifth Biennial Symposium, pp. 623-6.GlobalMagma, Carbonatite
DS2001-0142
2001
Buhn, B.Buhn, B.Fractionation modes and trace element characteristics of Phalaborwa type magmas: insights from bimodal...Journal of South African Earth Sciences, Vol. 32, No. 1, p. A 12 (abs)NamibiaCarbonatite, Otiisazu Complex
DS2001-0143
2001
Buhn, B.Buhn, B., Dorr, W., Brauns, C.M.Petrology and age of Otjisazu carbonatite complex: implications pre- and syJournal of African Earth Sciences, Vol. 32, No. 1, Jan. pp. 1-18.NamibiaCarbonatite
DS2001-0144
2001
Buhn, B.Buhn, B., Wall, F., LeBas, M.J.Rare element systematics of carbonatitic fluorapatites and their significance for carbonatite magma evolutionContributions to Mineralogy and Petrology, Vol. 141, No., 5, pp. 572-91.NamibiaCarbonatite - rare earth elements (REE).
DS2002-0218
2002
Buhn, B.Buhn, B., Rankin, A.H., Schneider, J., Dulski, P.The nature of orthomagmatic, carbonatitic fluids precipitating REE Sr rich flourite, fluid inclusion...Chemical Geology, Vol.186,1-2, pp. 75-98., Vol.186,1-2, pp. 75-98.NamibiaGeochronology - fluorite, Deposit - Okorusu
DS2002-0219
2002
Buhn, B.Buhn, B., Rankin, A.H., Schneider, J., Dulski, P.The nature of orthomagmatic, carbonatitic fluids precipitating REE Sr rich flourite, fluid inclusion...Chemical Geology, Vol.186,1-2, pp. 75-98., Vol.186,1-2, pp. 75-98.NamibiaGeochronology - fluorite, Deposit - Okorusu
DS2003-0178
2003
Buhn, B.Buhn, B., Trumbull, R.B.Comparison of petrogenetic signatures between mantle derived alkali silicate intrusivesLithos, Vol. 66, 3-4, pp. 195-220.NamibiaCarbonatite
DS2003-0179
2003
Buhn, B.Buhn, B., Trumbull, R.B.Comparison of petrogenetic signatures between mantle derived alkali silicate intrusivesLithos, Vol.67, 1-2, February, pp. 201-221.NamibiaEtaneno, Kalfeld complex, Ijolite
DS2003-1393
2003
Buhn, B.Trumbull, R.B., Buhn, B., Romer, R.L., Volker, F.The petrology of basanite tephrite intrusions in the Erongo Complex and implications forJournal of Petrology, Vol. 44, 1, pp. 93-112.NamibiaCarbonatite
DS200412-0235
2003
Buhn, B.Buhn, B., Trumbull, R.B.Comparison of petrogenetic signatures between mantle derived alkali silicate intrusives with and without associated carbonatite,Lithos, Vol.67, 1-2, February, pp. 201-221.Africa, NamibiaEtaneno, Kalfeld complex Ijolite
DS200812-0152
2008
Buhn, B.Buhn, 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
DS201312-0319
2013
Buhn, B.M.Gomide, C.S., Brod, J.A., Junqueira-Brod, T.C., Buhn, B.M., Santos, R.V., Barbosa, E.S.R., Cordeiro, P.F.O., Palmieri, M., Grasso, C.B., Torres, M.G.Sufur isotopes from Brazilian alkaline carbonatite complexes.Chemical Geology, Vol. 341, pp. 38-49.South America, BrazilDeposit - Tapira, Salitre, Serra Negra, Catalao, Jacupiringa
DS1991-0190
1991
Buhr, N.Buhr, N.The environmental audit: who needs it?Business Quarterly, Vol. 55, No. 3, Winter pp. 27-32CanadaEnvironmental, Not specific to mining companies
DS2003-0180
2003
Buhre, S.Buhre, S., Steinberg, H., Brey, G., Clark, S.Trace element solubility and reaction kinetics in the CAS system8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, POSTER abstractGlobalBlank
DS2003-0415
2003
Buhre, S.Foley, S.F., Buhre, S., Jacob, D.E.Evolution of the Archean crust by delamination and shallow subductionNature, No. 6920, Jan 16, pp. 249-51.MantleSubduction
DS2003-0416
2003
Buhre, S.Foley, S.F., Buhre, S., Jacob, D.E., Rehfeldt, T.Pyroxenite and dunite xenoliths as metamorphosed cumulates from the Archean lower8ikc, Www.venuewest.com/8ikc/program.htm, Session 2, POSTER abstractGlobalEclogites and Diamonds
DS200412-0236
2004
Buhre, S.Buhre, S., Brey, G.Al, Li and REE solubility and partitioning between CAS phases.Lithos, ABSTRACTS only, Vol. 73, p. S15. abstractSouth America, Brazil, Africa, Guinea, Tanzania, South Africa, RussiaTool to determine ascent path and origin of diamonds
DS200412-0237
2003
Buhre, S.Buhre, S., Steinberg, H., Brey, G., Clark, S.Trace element solubility and reaction kinetics in the CAS system.8 IKC Program, Session 6, POSTER abstractTechnologyMantle petrology
DS200912-0081
2009
Buhre, S.Buhre, S., Jacob, D.E., Foley, S.F.Delayed continental crust formation on a hot Archean Earth.Goldschmidt Conference 2009, p. A171 Abstract.MantleMelting
DS201012-0205
2009
Buhre, S.Foley, S.F., Yaxley, G.M., Rosenthal, A., Buhre, S., Kisseeva, E.S., Rapp, R.P., Jacob, D.E.The composition of near solidus melts of peridotite in the presence of CO2 and H2O between 40 and 60 kbar.Lithos, Vol. 112 S pp. 274-283.MantleMineral chemistry
DS201312-1017
2014
Buhre, S.Ziaja, K., Foley, S.F., White, R.W., Buhre, S.Metamorphism and melting of picritic crust in the early Earth.Lithos, Vol. 189, pp. 173-184.MantlePicrite
DS201707-1323
2017
Buhre, S.Forster, M.W., Orelevic, D., Schmuck, H.R., Buhre, S., Veter, M., Mertz-Kraus, R., Foley, S.F., Jacob, D.E.Melting and dynamic metasomatism of mixed harzburgite + glimmerite mantle source: implications for the genesis of orogenic potassic magmas.Chemical Geology, Vol. 455, pp. 182-191.Mantlemetasomatism

Abstract: Tectonically young, orogenic settings are commonly the sites of post-collisional silica-rich ultrapotassic magmas with extreme K2O-contents of up to 9 wt% and K2O/Na2O > 2. Many experimental studies investigating the generation of these melts have concentrated on melting of homogenous phlogopite bearing peridotites, whereas geochemical signatures indicate the involvement of at least two types of source rocks: ultra-depleted and K and trace elements-enriched ones. We report the results of melting experiments at 1–2 GPa of mixed glimmerite and harzburgite, in which these rock types make up two halves each capsule. Melting begins in the glimmerite, and its metasomatic effects on the harzburgite are apparent at 1100 °C even before melt pools are visible. The first melts are Na-rich, seen in zoning of olivines and as growth of clinopyroxene in the harzburgite, but change at higher degrees of melting to produce a typical lamproite-like melt with K2O > 10 wt%. A major advantage of this study is the preservation of distinct melts in different parts of the capsule, which reflect a process of dynamic metasomatism: within the harzburgite matrix, the infiltrating melt derived from melting of the glimmerite changes consistently with the distance of travel through the harzburgite, enabling quantification of the metasomatic effects as an increase in SiO2 and K2O. This results principally from assimilation of orthopyroxene, which increases the Ol/Opx ratio of the residual harzburgite. The effects of quench olivine growth are recognizable and can be quantified due to a step-change in composition at the glimmerite/harzburgite border: the large total surface area of olivine and small melt fraction mean that the amount of quench olivine is high within the harzburgite, but negligible in the almost completely molten glimmerite. Melts of the glimmerite contain up to 8–10 wt% K2O and 53 wt% SiO2, which increase to 55–56 wt% after interaction with the harzburgite. Mediterranean lamproites resemble melts of glimmerite, whereas melts that have interacted with harzburgite are more similar to less potassic, but more SiO2-rich shoshonites of the Mediterranean region.
DS201707-1381
2017
Buhre, S.Wang, Y., Prelevic, D., Buhre, S., Foley, S.F.Constraints on the sources of post-collisional K rich magmatism: the roles of continental clastic sediemtns and terrigenous blueschists.Chemical Geology, Vol. 455, pp. 192-207.Mantlemagmatism

Abstract: The possible role of continental sediments in the generation of potassium-enriched lavas of the Alpine-Himalayan belt depends on their melting behaviour either during subduction or during post-collisional relaxation. Although usually classed as orogenic lavas, these volcanic rocks may result from re-melting of newly formed mantle lithosphere 30–40 million years after collision ends, and can thus be considered as the first stage of intraplate volcanism. The potassic component in these volcanics is characterized by a high Th/La signature for which there are two competing explanations: melting of subducted continental clastic sediments, and the involvement of lawsonite blueschists in the protoliths to the melting assemblages. Here, we report on a series of high-pressure experiments at 1–3 GPa and 900 to 975 °C on the melting behaviour of natural phyllite from Serbia, which serves as a proxy for Balkan upper continental crust. Hydrous granitic melts are present in all runs (68 wt% SiO2, ~ 4–5 wt% K2O, Mg# < 54 and ~ 5 wt% H2O). Garnet, quartz/coesite, plagioclase, K-feldspar, biotite/phengite, clinopyroxene and sillimanite/kyanite, and accessory phases including zircon, rutile, ilmenite, apatite and monazite occur in the charges. LA-ICP-MS analyses establish that the melts are extremely enriched in LILE (except for Sr), Th and U, but depleted in Nb and Zr, with LREE higher than HREE. Accessory phases accommodate several trace elements, especially HFSE and REE. Partition coefficients for some trace elements between residue and crustal melts are close to 1, contrasting strongly with melts of peridotite. Our dataset indicates that the direct melting of upper continental crust alone would generate siliceous, high-K magmas with enriched LILE, Th and U, but cannot explain the high Th/La fingerprint of K-rich lavas of the Alpine-Himalayan orogenic belt. We demonstrate that the Alpine-Himalayan orogenic volcanics attribute their unusual trace element geochemistry to the involvement of lawsonite blueschists that are imbricated together with extremely depleted fore-arc peridotites to form new lithosphere in the source region. There is no need or evidence for deep subduction in which a succession of additional reactions would only serve to modify and dilute the high Th/La signature.
DS201804-0689
2018
Buhre, S.Forster, M.W., Prelevic, D., Schmuck, H.R., Buhre, S., Marschall, H.R., Mertz-Kraus, R., Jacob, D.E.Melting phologopite rich MARID: lamproites and the role of alkalis in olivine liquid Ni partioning.Chemical Geology, Vol. 476, 1, pp. 429-440.Technologylamproites

Abstract: In this study, we show how veined lithospheric mantle is involved in the genesis of ultrapotassic magmatism in cratonic settings. We conducted high pressure experiments to simulate vein + wall rock melting within the Earth's lithospheric mantle by reacting assemblages of harzburgite and phlogopite-rich hydrous mantle xenoliths. These comprised a mica-, amphibole-, rutile-, ilmenite-, diopside (MARID) assemblage at 3-5 GPa and 1325-1450 °C. Melting of the MARID assemblages results in infiltration of melt through the harzburgite, leading to its chemical alteration. At 3 and 4 GPa, melts are high in K2O (> 9 wt%) with K2O/Na2O > > 2 comparable to anorogenic lamproites. Higher pressures and temperatures (5 GPa/1450 °C) lead to increasing MgO contents of the melt and to some extent lower K2O contents (5-7 wt%) at equally high K2O/Na2O ratios. Our experiments provide insights into the role of alkalis in nickel-partitioning (DNi) between olivine and ultrapotassic melt. We observe that the high contents of Na, K, and Al are indicative of high DNi values, implying that the melt polymerization is the dominant factor influencing the olivine/melt nickel partitioning. The change of DNi as a function of melt composition results in a pressure independent, empirical geothermometer: Element oxides represent the composition of the glass (in wt%), and DNi is the liquid/olivine Ni-partitioning coefficient. We propose that this geothermometer is applicable to all natural silicate melts that crystallized olivine in a temperature interval between 1000 and 1600 °C. Application to glass-olivine pairs from calc-alkaline settings (Mexico), MORB (East Pacific Rise), and OIB (Hawaii) yielded reasonable values of 996-1199 °C, 1265 °C, and 1330 °C, respectively.
DS201905-1030
2019
Buhre, S.Forster, M.W., Prelevic, D., Buhre, S., Mertz-Kraus, R., Foley, S.F.An experimental study of the role of partial melts of sediments versus mantle melts in the sources of potassic magmatism.Journal of Asian Earth Sciences, Vol. 177, pp. 76-88.Mantlelamproite

Abstract: Potassium-rich lavas with K/Na of >2 are common in orogenic and anorogenic intraplate magmatic provinces. However, in the primitive mantle, the concentration of Na exceeds that of K by 10 times. The source of K-rich lavas thus needs to be either K-enriched or Na-depleted to account for high K/Na ratios. The geochemical and isotopic compositions of high 87Sr/86Sr post-collisional lavas show that their mantle source contains a recycled crustal component. These highly K-enriched lavas with crustal like trace element patterns are termed “orogenic lamproites” and are compositionally distinct from K-rich “anorogenic lamproites” that show lower 87Sr/86Sr and a trace element pattern that resembles that of primary mantle melts. For both groups the processes of K-enrichment within their source are uncertain and are thought to be linked to melts of sedimentary rocks for “orogenic lamproites” and low-degree melts of ultramafic mantle rocks for “anorogenic lamproites”. In both cases, metasomatism of the mantle lithosphere is the precursor to K-rich magmatism. In this study we experimentally determine the effects of mantle metasomatism by sediment- and hydrous mantle melts. The experiments simulate the interaction of refractory lithospheric mantle and metasomatizing melt in a 2-layer reaction experiment. The sediment/dunite reaction experiments lead to formation of a strongly K-enriched phlogopite-pyroxenite layer sandwiched between the two starting materials. The low temperature of the sediment/dunite reaction runs at <1000?°C simulates a fore-arc subduction environment, in which the melts of sediment are consumed during interaction with dunite as the temperature is below the solidus of the produced phlogopite-pyroxenites. The hydrous mantle melt/dunite reaction run is simulated by reacting a hydrated basanite with dunite. Since the temperature of the reaction is higher than the solidus of the resulting phlogopite-pyroxenites (1200?°C), the hydrous melt is not consumed but flows further, increasing in K2O and K/Na as it reacts with the refractory peridotite. In both cases, melts are enriched in K and K/Na increases by crystallizing a low K and low K/Na eclogitic residue. Compositions of glass and phlogopite from both types of reactions are comparable to glasses and phlogopites found within post-collisional lavas. Since the enrichment of K within the reaction zone is strongly controlled by the formation of low K/Na and low-K residues, metasomatic enrichment of the mantle lithosphere in K does not need a highly K-enriched metasomatic agent.
DS201907-1545
2019
Buhre, S.Forster, M.W., Foley, S.F., Marschall, H.R., Alard, O., Buhre, S.Melting of sediments in the deep mantle produces saline fluid inclusions in diamonds.Science Advances, Vol. 5, 5, eaau 2620 7p.Mantlediamond inclusions

Abstract: Diamonds growing in the Earth’s mantle often trap inclusions of fluids that are highly saline in composition. These fluids are thought to emerge from deep in subduction zones and may also be involved in the generation of some of the kimberlite magmas. However, the source of these fluids and the mechanism of their transport into the mantle lithosphere are unresolved. Here, we present experimental results showing that alkali chlorides are stable solid phases in the mantle lithosphere below 110 km. These alkali chlorides are formed by the reaction of subducted marine sediments with peridotite and show identical K/Na ratios to fluid inclusions in diamond. At temperatures >1100°C and low pressures, the chlorides are unstable; here, potassium is accommodated in mica and melt. The reaction of subducted sediments with peridotite explains the occurrence of Mg carbonates and the highly saline fluids found in diamonds and in chlorine-enriched kimberlite magmas.
DS201909-2039
2019
Buhre, S.Forster, M.W., Foley, S.F., Alard, O., Buhre, S.Partitioning of nitrogen during melting and recycling in subduction zones and the evolution of atmospheric nitrogen.Chemical Geology, in press available 31p. PdfMantlesubduction, metasomatism

Abstract: The subduction of sediment connects the surface nitrogen cycle to that of the deep Earth. To understand the evolution of nitrogen in the atmosphere, the behavior of nitrogen during the subduction and melting of subducted sediments has to be estimated. This study presents high-pressure experimental measurements of the partitioning of nitrogen during the melting of sediments at sub-arc depths. For quantitative analysis of nitrogen in minerals and glasses, we calibrated the electron probe micro-analyzer on synthetic ammonium feldspar to measure nitrogen concentrations as low as 500??g?g?1. Nitrogen abundances in melt and mica are used together with mass balance calculations to determine DN(Mica/Melt), DN(Fluid/Mica), and DN(Fluid/Melt). Calculated partition coefficients correspond to expected values for NH4+, which behaves similarly to Rb+ due to its nearly identical size. Nitrogen partitioning between fluid and melt (DN(Fluid/Melt)) and fluid and bulk residue (melt+mica) (DN(Fluid/Bulk)) increase linearly with temperature normalized to pressure. This linear relationship can be used to calculate DN(Fluid/Melt) and DN(Fluid/Bulk) for slab melts from 800 to 1200?°C following: and [nasty equation that did not copy]. We used these partition coefficients to quantify the amount of N recycled into the mantle as 50?±?6% of today's atmospheric N. Depending on the rate of mantle N degassing we calculated 4 different scenarios for atmospheric pN2 evolution. All 4 scenarios estimate pN2 to be 8-12% higher at the beginning of the Phanerozoic. These estimates diverge towards the past due to uncertainties in the mechanism and magnitude of N degassing from the mantle. Assuming degassing of N in the past was close to modern degassing rates from MORB, pN2 was up to 40% higher at the onset of plate tectonics at 3-4?Ga. However, degassing rates were probably higher than this: assuming 10× and 20× times higher rates at the onset of plate tectonics leads to pN2 within 20% of modern values. If N degassing from the mantle is increased to 40× the modern MORB rate, pN2 in the Archean would have been 50% lower than today's, which is in accordance with observations from paleoatmospheric studies.
DS201912-2781
2019
Buhre, S.Forster. M.W., Prelevic, D., Buhre, S., Mertz-Kraus, R., Foley, S.F.An experimental study of the role of partial melts of sediments versus mantle melts in the sources of potassic magmatism.Journal of Asian Earth Sciences, Vol. 177, pp. 76-88.Mantlemetasomatism

Abstract: Potassium-rich lavas with K/Na of >2 are common in orogenic and anorogenic intraplate magmatic provinces. However, in the primitive mantle, the concentration of Na exceeds that of K by 10 times. The source of K-rich lavas thus needs to be either K-enriched or Na-depleted to account for high K/Na ratios. The geochemical and isotopic compositions of high 87Sr/86Sr post-collisional lavas show that their mantle source contains a recycled crustal component. These highly K-enriched lavas with crustal like trace element patterns are termed “orogenic lamproites” and are compositionally distinct from K-rich “anorogenic lamproites” that show lower 87Sr/86Sr and a trace element pattern that resembles that of primary mantle melts. For both groups the processes of K-enrichment within their source are uncertain and are thought to be linked to melts of sedimentary rocks for “orogenic lamproites” and low-degree melts of ultramafic mantle rocks for “anorogenic lamproites”. In both cases, metasomatism of the mantle lithosphere is the precursor to K-rich magmatism. In this study we experimentally determine the effects of mantle metasomatism by sediment- and hydrous mantle melts. The experiments simulate the interaction of refractory lithospheric mantle and metasomatizing melt in a 2-layer reaction experiment. The sediment/dunite reaction experiments lead to formation of a strongly K-enriched phlogopite-pyroxenite layer sandwiched between the two starting materials. The low temperature of the sediment/dunite reaction runs at <1000?°C simulates a fore-arc subduction environment, in which the melts of sediment are consumed during interaction with dunite as the temperature is below the solidus of the produced phlogopite-pyroxenites. The hydrous mantle melt/dunite reaction run is simulated by reacting a hydrated basanite with dunite. Since the temperature of the reaction is higher than the solidus of the resulting phlogopite-pyroxenites (1200?°C), the hydrous melt is not consumed but flows further, increasing in K2O and K/Na as it reacts with the refractory peridotite. In both cases, melts are enriched in K and K/Na increases by crystallizing a low K and low K/Na eclogitic residue. Compositions of glass and phlogopite from both types of reactions are comparable to glasses and phlogopites found within post-collisional lavas. Since the enrichment of K within the reaction zone is strongly controlled by the formation of low K/Na and low-K residues, metasomatic enrichment of the mantle lithosphere in K does not need a highly K-enriched metasomatic agent.
DS202002-0185
2020
Buhre, S.Forster, M.W., Buhre, S., Xu, B., Prelevic, D., Mertz-Kraus, R., Foley, S.F.Two stage origin of K-enrichment in ultrapotassic magmatism simulated by melting of experimentally metasomatized mantle.MDPI Minerals, Vol. 10, 41;doe.10.3390/min10010041 21p. PdfMantlemetasomatism

Abstract: The generation of strongly potassic melts in the mantle requires the presence of phlogopite in the melting assemblage, while isotopic and trace element analyses of ultrapotassic rocks frequently indicate the involvement of subducted crustal lithologies in the source. However, phlogopite-free experiments that focus on melting of sedimentary rocks and subsequent hybridization with mantle rocks at pressures of 1-3 GPa have not successfully produced melts with K2O >5 wt%-6 wt%, while ultrapotassic igneous rocks reach up to 12 wt% K2O. Accordingly, a two-stage process that enriches K2O and increases K/Na in intermediary assemblages in the source prior to ultrapotassic magmatism seems likely. Here, we simulate this two-stage formation of ultrapotassic magmas using an experimental approach that involves re-melting of parts of an experimental product in a second experiment. In the first stage, reaction experiments containing layered sediment and dunite produced a modally metasomatized reaction zone at the border of a depleted peridotite. For the second-stage experiment, the metasomatized dunite was separated from the residue of the sedimentary rock and transferred to a smaller capsule, and melts were produced with 8 wt%-8.5 wt% K2O and K/Na of 6-7. This is the first time that extremely K-enriched ultrapotassic melts have been generated experimentally from sediments at low pressure applicable to a post-collisional setting.
DS202110-1614
2021
Buhre, S.Forster, M.W., Bussweiler, Y., Prelevic, D., Daczko, N.R., Buhre, S., Mertz-Kraus, R., Foley, S.F.Sediment-peridotite reaction controls fore-arc metasomatism and arc magma geochemical signatures.Geosciences MDPI, Vol. 11, 372, 24p. PdfMantlesubduction

Abstract: Subduction of oceanic crust buries an average thickness of 300-500 m of sediment that eventually dehydrates or partially melts. Progressive release of fluid/melt metasomatizes the fore-arc mantle, forming serpentinite at low temperatures and phlogopite-bearing pyroxenite where slab surface reaches 700-900 °C. This is sufficiently high to partially melt subducted sediments before they approach the depths where arc magmas are formed. Here, we present experiments on reactions between melts of subducted sediments and peridotite at 2-6 GPa/750-1100 °C, which correspond to the surface of a subducting slab. The reaction of volatile-bearing partial melts derived from sediments with depleted peridotite leads to separation of elements and a layered arrangement of metasomatic phases, with layers consisting of orthopyroxene, mica-pyroxenite, and clinopyroxenite. The selective incorporation of elements in these metasomatic layers closely resembles chemical patterns found in K-rich magmas. Trace elements were imaged using LA-ICP-TOFMS, which is applied here to investigate the distribution of trace elements within the metasomatic layers. Experiments of different duration enabled estimates of the growth of the metasomatic front, which ranges from 1-5 m/ky. These experiments explain the low contents of high-field strength elements in arc magmas as being due to their loss during melting of sedimentary materials in the fore-arc.
DS200612-0419
2006
Bui, H.A.Funicello, F., Moroni, M., Piromallo, C., Faccenna, C., Cenedese, A., Bui, H.A.Mapping mantle flow during retreating subduction: laboratory models analyzed by feature tracking.Journal of Geophysical Research, Vol. 111, B3, B3402 10.1029/2005 JB003792MantleGeophysics - seismics
DS201312-0344
2013
Bui, T.H.Guiliani, A., Phillips, D., Fiorentini, M.L., Kendrick, M.A., Maas, R., Wing, B.A., Woodhead, J.D., Bui, T.H., Kamenetsky, V.S.Mantle oddities: a sulphate fluid preserved in a MARID xenolith from the Bultfontein kimberlite ( Kimberley South Africa).Earth and Planetary Science Letters, Vol. 376, pp. 74-86.Africa, South AfricaDeposit - Bultfontein
DS2000-0119
2000
Bui Minh TaM.Bui Minh TaM.Petro-chemical features of the phlogopite lamproites (orendites) in Mang Xim area, central Vietnam.Igc 30th. Brasil, Aug. abstract only 1p.GlobalDike - Kontum geoblock, Lamproites
DS1992-0660
1992
Buick, I.S.Hand, M., Dirks, P.H.G.M., Powell, R., Buick, I.S.How well established is isobaric cooling in Proterozoic orogenic belts? an example from the Arunta inlierGeology, Vol. 20, No. 7, July pp. 649-652Australiametamorphism, Proterozoic belts
DS1998-0181
1998
Buick, I.S.Buick, I.S., Uken, R., Gibson, R.L., Wallmach, T.High delta 13 C Paleoproterozoic carbonates from the Transvaal South AfricaGeology, Vol. 26, No. 10, Oct. pp. 875-8South AfricaKaapvaal Craton, Geochronology, Carbon
DS2001-0776
2001
Buick, I.S.Miller, J.A., Holdsworth, R.E., Buick, I.S., Hand, M.Continental reactivation and reworkingGeological Society of London, No. 184, 400p.GlobalBook - table of contents, Tectonics - basement orogeny
DS2003-0181
2003
Buick, I.S.Buick, I.S., Williams, I.S., Gibson, R.L., Cartwright, I., Miller, J.A.Carbon and U Pb evidence for a Paleoproterozoic crustal component in the CentralJournal of the Geological Society of London, Vol. 160, 4, pp. 601-12.South AfricaGeochronology, Mobile belt - not specific to diamonds
DS200412-0238
2003
Buick, I.S.Buick, I.S., Williams, I.S., Gibson, R.L., Cartwright, I., Miller, J.A.Carbon and U Pb evidence for a Paleoproterozoic crustal component in the Central Zone of the Limpopo Belt, South Africa.Journal of the Geological Society, Vol. 160, 4, pp. 601-12.Africa, South AfricaGeochronology Mobile belt - not specific to diamonds
DS2001-0775
2001
Buick, L.Miller, J., Holdsworth, R., Buick, L., Hand, M.Continental reactivation and reworkingGeological Society of London, No. 184, 450p. approx. $ 142.00GlobalBook - ad, Structure, faulting, Tectonics, crust, lithosphere
DS1995-0227
1995
Buick, R.Buick, R., et al.Record of emergent continental crust 3-5 billion years ago in the Pilbaracraton of AustraliaNature, Vol. 375, June 15, pp. 574-577AustraliaGeochronology, Craton -Pilbara
DS2000-0358
2000
Buick, R.Green, M.G., Sylvester, P.J., Buick, R.Growth and recycling of Early Archean continental crust: geochemical evidence from Pilbara Craton.Tectonophysics, Vol. 322, No. 1-2, pp. 69-88.AustraliaGeochemistry - subduction
DS1930-0278
1938
Buie, B.F.Larsen, E.S., Buie, B.F.Potash Analcime and Pseudoleucite from the Highwood Mountains of Montana.American Mineralogist., Vol. 23, PP.837-849.Montana, Rocky MountainsLeucite
DS1940-0027
1941
Buie, B.F.Buie, B.F.Igneous Rocks of the Highwood Mountains, Montana. Pt. 3. Dikes and Related Intrusions.Geological Society of America (GSA) Bulletin., Vol. 52, No. 11, PP. 1753-1809.Montana, United States, Rocky MountainsDiatreme
DS200512-0118
2005
Buikin, A.Buikin, A., Trieloff, M., Hopp,J., Althaus, T., Korochantseva, E., Schwarz, W.H., Altherr, R.Noble gas isotopes suggest deep mantle plume source of late Cenozoic mafic alkaline volcanism in Europe.Earth and Planetary Science Letters, Vol. 230, 1-2, pp. 143-162.EuropeAlkaline rocks, geochronology
DS201312-0126
2012
Buikin, A.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
DS200512-0119
2005
Buikin, A.I.Buikin, A.I., Trieloff, M., Ryabchikov, I.D.40 Ar 39 Ar dating of a phlogopite bearing websterite: evidence for ancient metasomatism in the subcontinental lithosphere mantle under the Arabian Shield?Doklady Earth Sciences, Vol. 400, 1, pp. 44-48.Africa, ArabiaGeochronology
DS200512-0120
2005
Buikin, A.I.Buikin, A.I., Trieloff, M., Ryanchikov, I.D.40 Ar 39 Ar dating of a phlogopite bearing websterite: evidence for ancient metasomatism in the subcontinental lithospheric mantle under the Arabian Shield?Doklady Earth Sciences, Vol. 400, 1, pp. 44-48.Asia, ArabiaGeochronology
DS201112-0125
2010
Buikin, A.I.Buikin, A.I., Trieloff, M., Korochantseeva, E.V., Hopp, J., Kaliwood, M., Meyer, H-P.,Altherr, R.Distribution of mantle and atmospheric argon in mantle xenoliths from western Arabian Peninsula: constraints on timing and composition of metasomatizing agents....Journal of Petrology, Vol. 51, pp. 2547-2570.Africa, ArabiaMetasomatism
DS201112-0126
2011
Buikin, A.I.Buikin, A.I., Verchovsky, A.B., Grinenko, V.A., Kogarko, L.N.The first stepwise crushing dat a on C, N and Ar isotopic and elemental ratios in Guli carbonatites.Goldschmidt Conference 2011, abstract p.596.Russia, YakutiaMaymecha-Kotuy magmatic complex
DS201412-0078
2014
Buikin, A.I.Buikin, A.I., Verchovsky, A.B., Sorokhtina, N.V., Kogarko, L.N.Composition and sources of volatiles and noble gases in fluid inclusions in pyroxenites and carbonatites of the Seblyar Massif, Kola Peninsula.Petrology, Vol. 22, 5, p. 507-520.Russia, Kola PeninsulaAlkalic
DS201605-0816
2016
Buikin, A.I.Buikin, A.I., Verchovsky, A.B., Kogarko, L.N., Grinenko, V.A., Kuznetsova, O.V.The fluid phase evolution during the formation of carbonatite of the Guli Massif: evidence from the isotope ( C, N, Ar) data.Doklady Earth Sciences, Vol. 466, 2, Feb. pp. 135-137.RussiaCarbonatite

Abstract: The first data on variations of the isotope composition and element ratios of carbon, nitrogen, and argon in carbonatites of different generations and ultrabasic rocks of the Guli massif obtained by the method of step crushing are reported. It is shown that early carbonatite differs significantly from the later ones by the concentration of highly volatile components, as well as by the isotope compositions of carbon (CO2), argon, and hydrogen (H2O). The data obtained allow us to conclude that the mantle component predominated in the fluid at the early stages of formation of rocks of the Guli massif, whereas the late stages of carbonatite formation were characterized by an additional fluid source, which introduced atmospheric argon, and most likely a high portion of carbon dioxide with isotopically heavy carbon.
DS201707-1311
2017
Buikin, A.I.Buikin, A.I., Kogarko, L.N., Hopp, J., Trieloff, M.Light noble gas dat a in Guli massif carbonatites reveal the subcontinental lithospheric mantle as primary fluid source.Geochemistry International, Vol. 55, 5, pp. 457-464.Russiacarbonatite - Guli

Abstract: For better understanding of the fluid phase sources of carbonatites of Guli alkaline-ultrabasic intrusion (Maymecha-Kotuy complex) we have studied isotope composition of He and Ne in the carbonatites of different formation stages. The data definitely point to the subcontinental lithospheric mantle (SCLM) as a primary source of fluid phase of Guli carbonatites. The absence of plume signature in such a plume-like object (from petrological point of view) could be explained in terms that Guli carbonatites have been formed at the waning stage of plume magmatic activity with an essential input of SCLM components.
DS202112-1921
2021
Buikin, A.J.Buikin, A.J., Hopp, J., Verchovsky, A., Trieloff, M.The sources and evolution of fluid phases of Guli Massif carbonatites ( West Siberia): summarizing of noble gases, N2, CO2, H2O stepwise crushing data.Petrology, Vol. 29, 6, pp. 657-675. pdfRussia, Siberiadeposit - Guli Massif

Abstract: Here we present summarizing of isotopic compositions and element ratios of noble gases, nitrogen, carbon and hydrogen in carbonatites of different generations of the Guli massif (West Siberia, Russia) obtained by stepwise crushing. The data point to the subcontinental lithospheric mantle (SCLM) as a primary source of the fluid phase in Guli carbonatites. However, the estimated 40Ar/36Ar ratio in the Guli mantle source of about 5400 is similar to the Kola plume value of 5000 ± 1000 (Marty et al., 1998). One explanation of such a low estimated 40Ar/36Ar ratio in the mantle end-member with SCLM type helium (4??/3?? ~ 120000) and neon (21N?/22N?mantle ~ 0.7) is an admixture of atmospheric argon to the local mantle source. This assumption is supported by the Ar-Ne systematics as well as by the data for hydrogen isotopic composition. Early carbonatite differs significantly from the later ones by the concentration of highly volatile components, as well as by the isotopic compositions of carbon (CO2), argon, and hydrogen (H2O). The mantle component dominated in fluids at the early formation stages of the Guli massif rocks, whereas the late stages of carbonatite formation were characterized by an additional fluid source, which introduced atmospheric argon and neon, and most likely a high portion of CO2 with isotopically heavy carbon. The argon-neon-hydrogen isotope systematics suggest that the most plausible source of these late stage fluids are high temperature paleometeoric waters. The absence of a plume signature could be explained in terms that Guli carbonatites have been formed at the waning stage of plume magmatic activity with an essential input of SCLM components.
DS1988-0662
1988
Builov, L.L.Spitsyn, B.V., Builov, L.L., Deryagin, B.V.Diamond and diamond like films: deposition from the vapor phase structure and propertiesProg. Cryst. Growth Charact, Vol. 17, No. 2, pp. 79-170GlobalCitation states in English and a Review, CVD Diamond application
DS1993-0775
1993
Buima, T.Kaminsky, 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
Buima, T.Kaminsky, 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
DS1975-0466
1977
BuiskoolBoland, 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
DS200912-0082
2009
Buisman, I.Buisman, I., Sparks, S., Walker, M.Towards a better understanding of the origin and evolution of kimberlite melts using melt phase relations in CMAS-CO2-H2O-K2O.Goldschmidt Conference 2009, p. A172 Abstract.MantleMelting
DS200912-0083
2008
Buisman, I.Buisman, I., Sparks, S., Walter, M.The origin and evolution of kimberlite melts: stabilizing phlogopite in the CMAS-CO2-H2O-K2O system.American Geological Union, Fall meeting Dec. 15-19, Eos Trans. Vol. 89, no. 53, meeting supplement, 1p. abstractMantleMelting
DS201212-0092
2012
Buisman, I.Brown, R.J., Manya, S., Buisman, I., Fontana, G., Field, M., MacNiocaill, C., Sparks, R.S.J., Stuart, F.M.Eruption of kimberlite magmas: physical volcanology, geomrphology and age of the youngest kimberlitic volcanoes known on Earth ( the Upper Pleistocene-Holocene Igwisi Hills, volcanoes, Tanzania.Bulletin of Volcanology, Vol. 74, 7, pp. 1621-1643.Africa, TanzaniaIgwisi Hills
DS201212-0093
2012
Buisman, I.Brown, R.J., Manya, S., Buisman, I., Sparks, R.S.J., Field, M., Stuart, F.M., Fontana, G.Physical volcanology, geomorphology, and cosmogenic 3HE dating of the youngest kimberlite volcanoes on Earth ( The Holocene Igwisi Hills, Volcanoes, Tanzania.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractAfrica, TanzaniaIgwisi Hills - geochronology
DS201212-0095
2012
Buisman, I.Buisman, I., Sparks, R.S.J., Walter, M.J., Brown, R.J., Manya, S., Kavanagh, J.Olivine chemistry of exceptionally young ( Holocene) kimberlite of the Igwisi Hills volcano, Tanzania.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractAfrica, TanzaniaDeposit - Igwisi
DS201212-0694
2012
Buisman, I.Sparks, R.S.J., Buisman, I., Brooker, R., Brown, R.J., Field, M., Gernon, T., Kavanagh,J., Ogilvie-Harris, R., Schumacher, J.C.Dynamics of kimberlite magam ascent, intrusion and eruption.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractGlobalDiamond genesis
DS201412-0079
2014
Buisman, I.Buisman, I., Sparks, R.S.J., Brown, R., Manya, S.Microanalysis of olivine chemistry of exceptionally young kimberlite of the Igwisi Hills, volcano, Tanzania.Volcanic and Magmatic Studies Group meeting, Poster Held Jan. 6-8. See minsoc websiteAfrica, TanzaniaIgwisi
DS201212-0091
2012
Buisman, M.I.Brown, R.J., Buisman, M.I., Fontana, G., Field, M., Mac Niocaill, C., Sparks, R.S.J., Stuart, F.M.Eruption of kimberlite magmas: physical volcanology, geomorphology and age of the youngest kimberlitic volcanoes known on Earth ( the Upper Pleistocene/Holocene Igwisi Hills volcanoes, Tanzania).Bulletin Volcanology, in press availableAfrica, TanzaniaDeposit - Igwisi
DS200612-0192
2006
Buiter, J.H.Buiter, J.H., Schreurs, G.Analogue and numerical modelling of crustal scale processes.Geological Society of London Special Publication, SP 253, 456p.MantleBook - models, deformation, computer models
DS2002-0220
2002
Buiter, S.J.H.Buiter, S.J.H., Govers, R., Wortel, M.J.R.Two dimensional simulations of surface deformation caused by slab detachmentTectonophysics, Vol. 354, 3-4, pp. 195-210.GlobalTectonics - not specific to diamonds
DS200612-0193
2006
Buiter, S.J.H.Buiter, S.J.H., Schreurs, G.Analogue and numerical modelling of crustal scale processes.Geological Society of London, Special Publication, No. 253, 336p. $ 200.00MantleOrogenic processes, deformation
DS201112-0300
2011
Buiter, S.J.H.Ellis, S.M., Little,T.A., Wallace, L.M.,Hacker, B.R., Buiter, S.J.H.Feedback between rifting and diapirism can exhume ultrahigh pressure rocks.Earth and Planetary Science Letters, Vol. 311, 3-4, pp. 427-438.AustraliaUHP
DS201112-0838
2011
Buiter, S.J.H.Quinquis, M.E.T., Buiter, S.J.H., Ellis, S.The role of boundary conditions in numerical models of subduction zone dynamics.Tectonophysics, Vol. 497, pp. 57-70.MantleSubduction
DS201112-1074
2011
Buiter, S.J.H.Van Hinsbergen, D.J.J., Buiter, S.J.H., Torsvik, T.H., Gaina, C., Webb, S.J.The formation and evolution of Africa from the Archean to Present; introduction.The Formation and Evolution of Africa: A synopsis of 3.8 Ga of Earth History, Geol. Soc. London Special Publ., 357, pp. 1-8.AfricaHistory
DS201312-0387
2011
Buiter, S.J.H.Hinsbergen, D.J.J., Buiter, S.J.H., Torsvik, T.H., Gaina, G., Webb, S.J.Formation and evolution of Africa: a synopsis of 3.8 Ga of Earth history.Geological Society of London, Special Publication no. 357, 378p. Approx 120 lbsAfricaTectonics
DS201412-0080
2014
Buiter, S.J.H.Buiter, S.J.H., Torsvik, T.H.A review of Wilson Cycle plate margins: a role for mantle plumes in continental break-up along sutures?Gondwana Research, in press availableMantleHotspots
DS201911-2574
2019
Buiter, S.J.H.Wilson, R.W., Huseman, G.A., Buiter, S.J.H., McCaffrey, K.J.W., Dore, A.G.Fifty years of the Wilson Cycle concept in plate tectonics: an overview.IN: Cycle Concepts in Plate Tectonics, editors Wilson and Houseman , Geological Society of London special publication 470, pp. 1-17. pdfMantleplate tectonics

Abstract: It is now more than 50 years since Tuzo Wilson published his paper asking ‘Did the Atlantic close and then re-open?’. This led to the ‘Wilson Cycle’ concept in which the repeated opening and closing of ocean basins along old orogenic belts is a key process in the assembly and breakup of supercontinents. This implied that the processes of rifting and mountain building somehow pre-conditioned and weakened the lithosphere in these regions, making them susceptible to strain localization during future deformation episodes. Here we provide a retrospective look at the development of the concept, how it has evolved over the past five decades, current thinking and future focus areas. The Wilson Cycle has proved enormously important to the theory and practice of geology and underlies much of what we know about the geological evolution of the Earth and its lithosphere. The concept will no doubt continue to be developed as we gain more understanding of the physical processes that control mantle convection and plate tectonics, and as more data become available from currently less accessible regions.
DS2001-1072
2001
BukalovShumilova, T.G., Mikhalitsyn, Bukalov, LeitesInvestigation of the ordering of skeletal diamonds from the Kumdykol deposit by Raman spectroscopy and lumin.Doklady Academy of Sciences, Vol. 378, No. 4, May-June pp. 390-3.RussiaDiamond - morphology, Luminesence
DS1993-0183
1993
Bukatnikov, V.D.Bukatnikov, V.D., Shamaitis, Y.I.Tailings facilities of Almazy Rossii Sakha treatment plantsDiamonds of Yakutia, pp. 181-185.Russia, YakutiaMining, Tailings plant
DS201801-0077
2017
Bukharova, O.V.Vrublevskii, V.V., Morova, A.A., Bukharova, O.V., Konovalenko, S.I.Mineralogy and geochemistry of triassic carbonatites in the Matcha alkaline intrusive complex ( Turkestan-Alai Ridge, Kyrhyz southern Tien Shan), SW Central Asian orogenic belt.Journal of Asian Earth Sciences, in press availabe, 30p.Asia, Tien Shancarbonatites

Abstract: Postorogenic intrusions of essexites and alkaline and nepheline syenites in the Turkestan-Alai segment of the Kyrgyz Southern Tien Shan coexist with dikes and veins of carbonatites dated at ?220?Ma by the Ar-Ar and Rb-Sr age methods. They are mainly composed of calcite and dolomite (60-85%), as well as sodic amphibole, phlogopite, clinopyroxene, microcline, albite, apatite, and magnetite, with accessory niobate, ilmenite, Nb-rutile, titanite, zircon, baddeleyite, monazite-(Ce), barite, and sulfides. The rocks share mineralogical and geochemical similarity with carbonatites that originated by liquid immiscibility at high temperatures above 500?°C. Alkaline silicate and salt-carbonate melts are derived from sources with mainly negative bulk ?Nd(t) ? from ?11 to 0 and high initial 87Sr/86Sr ratios (?0.7061-0.7095) which may be due to mixing of PREMA and EM?type mantle material. Pb isotopic ratios in accessory pyrrhotite (206Pb/204Pb?=?18.38; 207Pb/204Pb?=?15.64; 208Pb/204Pb?=?38.41) exhibit an EM2 trend. The intrusions bear signatures of significant crustal contamination as a result of magma genesis by syntexis and hybridism. Concordant isotope composition changes of ?13C (?6.5 to ?1.9‰), ?18O (9.2-23‰), ?D (?58 to ?41‰), and ?34S (12.6-12.8‰) in minerals and rocks indicate inputs of crustal material at the stage of melting and effect of hot fluids released during dehydration of metamorphosed oceanic basalts or sediments. The observed HFSE patterns of the oldest alkaline gabbro may be due to interaction of the primary mafic magma with IAB-type material. The isotope similarity of alkaline rocks with spatially proximal basalts of the Tarim large igneous province does not contradict the evolution of the Turkestan-Alai Triassic magmatism as the “last echo” of the Tarim mantle plume.
DS201802-0278
2018
Bukharova, O.V.Vrublevskii, V.V., Morova, A.A., Bukharova, O.V., Konovalenko, S.I.Mineralogy and geochemistry of Triassic carbonatites in the Matcha alkaline intrusive complex ( Turkestan-Alai Ridge, Kyrgyz southern Tien Shan) sw central Asian orogenic belt.)Journal of Asian Earth Sciences, Vol. 153, pp. 252-281.Asiacarbonatite

Abstract: Postorogenic intrusions of essexites and alkaline and nepheline syenites in the Turkestan-Alai segment of the Kyrgyz Southern Tien Shan coexist with dikes and veins of carbonatites dated at ?220?Ma by the Ar-Ar and Rb-Sr age methods. They are mainly composed of calcite and dolomite (60-85%), as well as sodic amphibole, phlogopite, clinopyroxene, microcline, albite, apatite, and magnetite, with accessory niobate, ilmenite, Nb-rutile, titanite, zircon, baddeleyite, monazite-(Ce), barite, and sulfides. The rocks share mineralogical and geochemical similarity with carbonatites that originated by liquid immiscibility at high temperatures above 500?°C. Alkaline silicate and salt-carbonate melts are derived from sources with mainly negative bulk ?Nd(t) ? from ?11 to 0 and high initial 87Sr/86Sr ratios (?0.7061-0.7095) which may be due to mixing of PREMA and EM?type mantle material. Pb isotopic ratios in accessory pyrrhotite (206Pb/204Pb?=?18.38; 207Pb/204Pb?=?15.64; 208Pb/204Pb?=?38.41) exhibit an EM2 trend. The intrusions bear signatures of significant crustal contamination as a result of magma genesis by syntexis and hybridism. Concordant isotope composition changes of ?13C (?6.5 to ?1.9‰), ?18O (9.2-23‰), ?D (?58 to ?41‰), and ?34S (12.6-12.8‰) in minerals and rocks indicate inputs of crustal material at the stage of melting and effect of hot fluids released during dehydration of metamorphosed oceanic basalts or sediments. The observed HFSE patterns of the oldest alkaline gabbro may be due to interaction of the primary mafic magma with IAB-type material. The isotope similarity of alkaline rocks with spatially proximal basalts of the Tarim large igneous province does not contradict the evolution of the Turkestan-Alai Triassic magmatism as the “last echo” of the Tarim mantle plume.
DS201803-0484
2018
Bukharova, O.V.Vrubleyskii, V.V., Morova, A.A., Bukharova, O.V., Konovalenko, S.I.Mineralogy and geochemistry of Triassic carbonatites in the Matcha alkaline intrusive complex ( Turkestan Alai Ridge, Kyrgyz southern Tien Shan), SW central Asian orogenic belt.Journal of Asian Earth Sciences, Vol. 153, pp. 252-281.Asiacarbonatite
DS201907-1581
2019
Bukharova, O.V.Vrublevskii, V.V., Bukharova, O.V., Nebera, T.S., Sveshnikova, V.I.Composition and origin of rare metal ( Tb-Ta, REE) and sulfide mmineralization in magnesiocarbonatites from the Yenisei Ridge, central Siberia.Ore Geology Reviews, Vol. 111, 26p.Russia, Siberiacarbonatites
DS1990-0868
1990
Bukhbinder, G.V.Kolesnik, Yu.N., Stepchenko, S.B., Bukhbinder, G.V., AndrosenkoThe orthopyroxene garnet geobarometer for peridotitesInternational Geology Review, Vol. 32, No. 3, March pp. 228-243RussiaPeridotites, Geobarometry
DS201012-0576
2009
Bukhityarov, P.G.Persikov, E.S., Bukhityarov, P.G.Interrelated structural chemical model to predict and calculate viscosity of magmatic melts and water diffusion in a wide range of compositions and T-P parametersRussian Geology and Geophysics, Vol. 50, 12, pp. 1079-1090.MantleMagmatism
DS201810-2365
2018
Bukhityarov, P.G.Persikov, E.S., Bukhityarov, P.G., Sokol, A.G.Viscosity of haplokimberlitic and basaltic melts at high pressures: experimental and theoretical studies.Chemical Geology, Vol. 497, pp. 54-63.MantleUHP

Abstract: Only limited data are available at present on the viscosity of kimberlite magmas. We investigate viscosity of synthetic carbonate-bearing (silicate82?+?carbonate18, wt%, 100NBO/T?=?313) anhydrous haplokimberlite melts theoretically and in experiments. We use new experimental data on viscosity of anhydrous haplokimberlite melts and a physical-chemical model (Persikov and Bukhtiyarov 2009; Persikov et al. 2015) to compare basic viscosity features in kimberlitic and basaltic melts (100NBO/T?=?56). Viscosity of melts is determined by the falling sphere quenching method in a large range of temperatures from 1300 to 1950?°C and pressures up to 7.5?GPa. We use two types of high-pressure apparatuses: a high gas pressure apparatus and a high pressure split-sphere multi-anvil apparatus to study the viscosity of melts at moderate (100?MPa CO2 pressure) and high (5.5?GPa and 7.5?GPa) pressures, respectively. The measured viscosity ranges for anhydrous haplokimberlite melts are from 1.5 (±0.45) to 0.11(±0.03) Pa s. The temperature dependence of the viscosity of haplokimberlite and basaltic melts is consistent with the theoretical Arrhenian equation. At a constant temperature, viscosity of anhydrous haplokimberlite melts increases exponentially about ten-fold as pressure increases from 100?MPa to 7.5?GPa. The activation energy of viscous flow increases linearly with pressure increase from 100?MPa to 7.5?GPa for anhydrous haplokimberlite melts but decreases in the case of basaltic melts, with the minimum at ~5.5?GPa. At a moderate pressure (100?MPa), haplokimberlite melts are about twenty times less viscous than basaltic melts, but are about four times more viscous at a high pressure (7.5?GPa), the temperature being 1800?°C in both cases. The experimentally observed behavior of the viscosity of anhydrous haplokimberlite melts is consistent with predictions of the physical-chemical model within the range of uncertainties in both experimental and calculated data (±30% rel.). Thus, the physical-chemical model is used to discuss possible effects of volume percentages of crystals and bubbles on viscosity of kimberlitic and basaltic magmas at different pressures and temperatures during their origin, evolution, and ascent.
DS201412-0679
2014
Bukhtiyarov, P.Persikov, E., Bukhtiyarov, P., Skol, A., Palyanov, Y.Viscosity of kimberlite and basaltic magmas to 10 Gpa and 2000K.V.S. Sobolev Institute of Geology and Mineralogy Siberian Branch Russian Academy of Sciences International Symposium Advances in high pressure research: breaking scales and horizons ( Courtesy of N. Poikilenko), Held Sept. 22-26, 2p. AbstractMantleMagmatism
DS201507-0331
2015
Bukhtiyarov, P.G.Persikov, E.S., Bukhtiyarov, P.G., Sokol, A.G.Change in the viscosity of kimberlite and basaltic magmas during their origin and evolution ( prediction).Russian Geology and Geophysics, Vol. 56, pp. 885-892.Canada, Northwest Territories, RussiaDeposit - Jericho, Udachnaya
DS201712-2717
2017
Bukhtiyarov, P.G.Persikov, E.S., Bukhtiyarov, P.G., Sokol, A.G.Viscosity of hydrous kimberlite and basaltic melts at high pressures.Russian Geology and Geophysics, Vol. 58, pp. 1093-1100.Mantlekimberlite

Abstract: New experimental data on the temperature and pressure dependences of the viscosity of synthetic hydrous kimberlite melts (82 wt.% silicate + 18 wt.% carbonate; degree of depolymerization: 100NBO/T = 313 for anhydrous melts and 100NBO/T = 247 for melts with 3 wt.% H2O) were obtained at a water pressure of 100 MPa and at lithostatic pressures of 5.5 and 7.5 GPa in the temperature range 1300-1950 °C. The temperature dependence of the viscosity of these melts follows the exponential Arrhenius-Frenkel-Eyring equation in the investigated range of temperatures and pressures. The activation energies of viscous flow for hydrous kimberlite melts were first shown to increase linearly with increasing pressure. Under isothermal conditions (T = 1800 °C), the viscosity of hydrous kimberlite melts increases exponentially by about an order of magnitude as the pressure increases from 100 MPa to 7.5 GPa. The new experimental data on the viscosity of hydrous kimberlite melts (error ± 30 rel.%) are compared with forecast viscosity data for anhydrous kimberlite and basaltic melts (100NBO/T = 51.5) and for hydrous basaltic melts (100NBO/T = 80). It is shown that at comparable temperatures, the viscosity of hydrous kimberlite melts at a moderate pressure (100 MPa) is about an order of magnitude lower than the viscosity of hydrous basaltic melts, whereas at a high pressure (7.5 GPa) it is more than twice higher. It is first established that water dissolution in kimberlite melts does not affect seriously their viscosity (within the measurement error) at both moderate (100 MPa) and high (7.5 GPa) pressures, whereas the viscosity of basaltic melts considerably decreases with water dissolution at moderate pressures (100 MPa) and remains unchanged at high pressures (P > 3.5 GPa).
DS201803-0470
2017
Bukhtiyarov, P.G.Persikov, E.S., Bukhtiyarov, P.G., Sokol, A.G.Viscosity of hydrous kimberlite and basaltic melts at high pressures.Russian Geology and Geophysics, Vol. 58, pp. 1093-1100.Mantlemelting

Abstract: New experimental data on the temperature and pressure dependences of the viscosity of synthetic hydrous kimberlite melts (82 wt.% silicate + 18 wt.% carbonate; degree of depolymerization: 100NBO/T = 313 for anhydrous melts and 100NBO/T = 247 for melts with 3 wt.% H2O) were obtained at a water pressure of 100 MPa and at lithostatic pressures of 5.5 and 7.5 GPa in the temperature range 1300-1950 °C. The temperature dependence of the viscosity of these melts follows the exponential Arrhenius-Frenkel-Eyring equation in the investigated range of temperatures and pressures. The activation energies of viscous flow for hydrous kimberlite melts were first shown to increase linearly with increasing pressure. Under isothermal conditions (T = 1800 °C), the viscosity of hydrous kimberlite melts increases exponentially by about an order of magnitude as the pressure increases from 100 MPa to 7.5 GPa. The new experimental data on the viscosity of hydrous kimberlite melts (error ± 30 rel.%) are compared with forecast viscosity data for anhydrous kimberlite and basaltic melts (100NBO/T = 51.5) and for hydrous basaltic melts (100NBO/T = 80). It is shown that at comparable temperatures, the viscosity of hydrous kimberlite melts at a moderate pressure (100 MPa) is about an order of magnitude lower than the viscosity of hydrous basaltic melts, whereas at a high pressure (7.5 GPa) it is more than twice higher. It is first established that water dissolution in kimberlite melts does not affect seriously their viscosity (within the measurement error) at both moderate (100 MPa) and high (7.5 GPa) pressures, whereas the viscosity of basaltic melts considerably decreases with water dissolution at moderate pressures (100 MPa) and remains unchanged at high pressures (P > 3.5 GPa).
DS200712-0695
2007
Bukowinski, M.S.Matas, J., Bukowinski, M.S.On the An elastic contribution to the temperature dependence of lower mantle seismic veolcities.Earth and Planetary Science Letters, Vol. 259, 1-2, pp. 51-65.MantleGeophysics - seismics
DS200712-0696
2007
Bukowinski, M.S.Matas, J., Bukowinski, M.S.On the An elastic contribution to the temperature dependence of lower mantle seismic veolcities.Earth and Planetary Science Letters, Vol. 259, 1-2, pp. 51-65.MantleGeophysics - seismics
DS1990-0252
1990
Bukowinski, M.S.T.Bukowinski, M.S.T.Thermodynamically consistent decompression: implications for lower mantlecompositionJournal of Geophysical Research, Vol. 95, No. B8, August 10, pp. 12, 583-12, 593GlobalMantle, Mineralogy
DS1991-1661
1991
Bukowinski, M.S.T.Stixrude, L., Oshagan, A., Bukowinski, M.S.T.Coordination changes and the vibrational spectrum of SiO2 glass at high pressureressure.American Mineralogist, Vol. 76, pp. 1761-4.GlobalGlass
DS1993-0184
1993
Bukowinski, M.S.T.Bukowinski, M.S.T., et al.Status of theoretical searches for new lower mantle mineralsAmerican Geophysical Union, EOS, supplement Abstract Volume, October, Vol. 74, No. 43, October 26, abstract p. 551.MantleMineralogy
DS200612-0194
2005
Bukowinski, M.S.T.Bukowinski, M.S.T., Akber-Knutson, S.The role of theoretical mineral physics in modeling the Earth's interior.American Geophysical Union, Geophysical Monograph, ed. Van der Hilst, Earth's Deep mantle, structure ...., No. 160, pp. 137-164.MantleGeophysics - seismics
DS200712-0694
2007
Bukowinski, M.S.T.Matas, J., Bass, J., Ricard, Y., Mattern, E., Bukowinski, M.S.T.On the bulk composition of the lower mantle: predictions and limitations from generalized inversion seismic profiles.Geophysical Journal International, Vol. 170, 2, August pp. 764-780.MantleGeophysics - seismics
DS1960-0522
1965
Buks, I. I.Buks, I. I.The Use of Geobotanical Method in the Search for Kimberlite tubes in Yakutian Polar Region.In: Plant Indicators of Soils, Rocks And Subsurface Waters., PP. 173-175.RussiaBlank
DS2000-0844
2000
BulakhRudahevsky, N., Kretser, Y., Rudashevsky, V., BulakhNoble metal mineralization in carbonatites from Kovdor, Kola Peninsula, and Phalabora, South Africa.Igc 30th. Brasil, Aug. abstract only 1p.Russia, Kola Peninsula, South AfricaCarbonatite - mineralogy, Deposit - Kovdor, Phalabora
DS2001-0989
2001
BulakhRudashevsky, N.S., Kretser, Bulakh, RudashevskyTwo types of platinum group elements (PGE) mineralization in carbonatite deposits Phalaborwa Kovdor Massif.Journal of South African Earth Sciences, Vol. 32, No. 1, p. A 30.(abs)South Africa, RussiaCarbonatite, Palaborwa, Kovdor
DS1997-0297
1997
Bulakh, A.Dunworth, E.A., Bell, K., Arzamastsev, A.A., Bulakh, A.Age relationships, isotopic disequilibrium and trace element characteristics of the Turily Massif.....Geological Association of Canada (GAC) Abstracts, POSTER.Russia, Kola PeninsulaCarbonatite, Terskii Coast pipes
DS1997-0910
1997
Bulakh, A.B.Pilipiuk, A.N., Ivanikov, V.V., Bulakh, A.B.Unusual mineral assemblages in carbonatites from a new occurrence in the Kola Karelia region, Russia.Geological Association of Canada (GAC) Abstracts, POSTER.Russia, Kola, KareliaCarbonatite
DS1993-0185
1993
Bulakh, A.G.Bulakh, A.G.Rare metal mineralogy of foscorites and carbonatites of the KolaPeninsulaTerra Abstracts, IAGOD International Symposium on mineralization related to mafic, Vol. 5, No. 3, abstract supplement p. 7Russia, Kola PeninsulaCarbonatite
DS1994-0138
1994
Bulakh, A.G.Bell, K., Dunworth, E.A., Bulakh, A.G., Ivaniov, V.V.Terskii Coast, Russia: from kimberlite to carbonatite?Geological Association of Canada (GAC) Abstract Volume, Vol. 19, p.RussiaCarbonatite, Terskii Coast
DS1994-0233
1994
Bulakh, A.G.Bulakh, A.G.Carbonatites of Turi, Kola Peninsula, Russia -saga of magmatism andMetasomatismGeological Association of Canada (GAC) Abstract Volume, Vol. 19, p.Russia, Kola PeninsulaCarbonatite, Magma
DS1996-0109
1996
Bulakh, A.G.Bell, K., Dunworth, E.A., Bulakh, A.G., Ivanikov, V.V.Alkaline rocks of the Turiy Peninsula, Russia, including type localityturjaite and turjite: a reviewCanadian Mineralogist, Vol. 34, pt. 2, April pp. 265-280.RussiaAlkaline rocks, Petrology
DS1996-0190
1996
Bulakh, A.G.Bulakh, A.G., Ivanikov, V.V.Carbonatites of the Turi Peninsula, Kola: role of magmatism andMetasomatismCanadian Mineralogist, Vol. 34, pt. 2, April pp. 403-410.Russia, Kola PeninsulaCarbonatite, Turi area
DS1997-0140
1997
Bulakh, A.G.Bulakh, A.G., Nesterov, A.R., Anisimov, I.S., Williams, C.Sevlyavr carbonatite complex, Kola Peninsula, RussiaGeological Association of Canada (GAC) Abstracts, POSTER.Russia, Kola PeninsulaCarbonatite, Deposit - Sevlyavr
DS1997-0141
1997
Bulakh, A.G.Bulakh, A.G., Zaitsev, A.N., Le Bas, M.J., Wall, F.Ancylite bearing carbonatites of the Sevlyavr Massif, Kola PeninsulaGeological Association of Canada (GAC) Abstracts, POSTER.Russia, Kola PeninsulaCarbonatite, Deposit - Sevlyavr
DS1997-0298
1997
Bulakh, A.G.Dunworth, E.A., Bell, K., Bulakh, A.G., Ivanikov, V.V.The Turiy massif: the role of A1 coordination and major element partitioning in melilitolites, carbonatites...Geological Association of Canada (GAC) Abstracts, Russia, Kola PeninsulaCarbonatite
DS1998-0182
1998
Bulakh, A.G.Bulakh, A.G., Nesterov, A.R., Anisimov, I.S.Zirkelite from Seblyavr carbonatite complex, Kola Peninsula- xray and electron microprobe study metamictMineralogical Magazine, Vol. 62, No. 6, Dec. 1, pp. 837-46.Russia, Kola PeninsulaCarbonatite, Deposit - Seblyavr
DS1998-0183
1998
Bulakh, A.G.Bulakh, A.G., Rudashevsky, N.S., Karchevsky, P.I.Native gold and silver, sulphides and rare earth elements (REE) minerals in carbonatites from Loolekop deposit (RSA).Proceedings Russian Min. Soc. in RUSS, Vol. 127, No. 3, pp. 45-53.South AfricaCarbonatite, Sulphide mineralogy
DS1999-0613
1999
Bulakh, A.G.Rudashevsky, N.S., Kretser, Y.L., Bulakh, A.G.platinum group elements (PGE) mineralization of carbonatite depositsStanley, SGA Fifth Biennial Symposium, pp. 675-8.South Africa, Russia, Kola PeninsulaCarbonatite, Loolecop, Phalabora, Kovdor
DS2000-0120
2000
Bulakh, A.G.Bulakh, A.G.Carbonatites of the Kola alkaline province - 100 years of investigation. in RUSSIAN.Proceedings Russ. Min. Soc. *RUSS, Vol. 129, No. 2, pp. 133-Russia, Kola PeninsulaCarbonatite
DS2000-0121
2000
Bulakh, A.G.Bulakh, A.G., Nesterov, A.R., Kirillov, A.S.Sulphur containing monazite ( ce) from late stage mineral assemblages at the Kandaguba Vuoriyarvi KolaNeues Jahrbuch f?r Mineralogie, No. 5, May pp. 217-40.Russia, Kola PeninsulaCarbonatite, monazite
DS2001-0923
2001
Bulakh, A.G.Pilipiuk, A.N., Ivanikov, V.V., Bulakh, A.G.Unusual rocks and mineralization in a new carbonatite complex at Kandaguba Kola Peninsula, Russia.Lithos, Vol. 56, pp. 333-47.Russia, Kola PeninsulaChemistry - alkaline rocks, Kandaguba Complex
DS201112-0026
2010
Bulanonva, G.Araujo, D., Ribeiro, D., Bulanonva, G., Smith, C., Walter, M., Kohn, S.Diamond inclusions from the Juina-5 kimberlite, Brazil.5th Brasilian Symposium on Diamond Geology, Nov. 6-12, abstract p. 43.South America, Brazil, Mato GrossoDiamond inclusions
DS1987-0081
1987
Bulanov, G.P.Bulanov, G.P., Pavlova, L.P.Magnesite peridotite assemblage in diamond from the Mir pipe. (Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 295, No. 6, pp. 1452-1456RussiaBlank
DS1995-1966
1995
BulanovaVan Heerden, L.A., Taylor, W.R., Kirkley, Gurney, BulanovaComparison of physical spectroscopic and stable isotope characteristics of Roberts Victor diamonds.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 231-232.South AfricaCathodluminescence, Deposit -Roberts Victor
DS1998-1137
1998
BulanovaPearson, D.G., Shirey, S., Bulanova, Carlson, MilledgeDating diamonds using Rhenium- Osmium (Re-Os) isotope technique: a study of sulfide inclusions in Siberian diamonds.7th. Kimberlite Conference abstract, pp. 661-3.Russia, SiberiaGeochronology, Deposit - Udachnaya
DS1999-0542
1999
BulanovaPearson, D.G., Shirey, Bulanova, Carlson, MilledgeDating and paragenetic distinction of diamonds using Re- Os isotope system: application Siberian diamonds.7th International Kimberlite Conference Nixon, Vol. 2, pp. 637-43.Russia, SiberiaGeochronology, sulphide inclusions, age determination, Udachnaya, Mir
DS201112-1098
2011
BulanovaWalter, M.J., Kohn, Arajuo, Bulanova, Smith, Gaillou, Wang, Steele, ShireyDeep mantle cycling of oceanic crust: evidence from diamonds and their mineral inclusions.Science, Vol. 334, 6052, pp. 51-52.MantleDiamond inclusions
DS1991-0191
1991
Bulanova, B.Bulanova, B., Varlamov, D.A., Garanin, V.K., Kudjavtseva, G.P.Chemico-genetic classification of the most important minerals-satellites Of the diamondProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 490-491RussiaMineral chemistry, Genesis
DS1995-1882
1995
Bulanova, G.Taylor, W.R., Bulanova, G., Milledge, H.J.Quantitative nitrogen aggregation study of some Yakutian diamonds:constraints on growth... diamondsProceedings of the Sixth International Kimberlite Conference Abstracts, pp. 608-610.Russia, YakutiaEclogites, peridotites, Deposit -Mir, Udachnaya
DS1998-1444
1998
Bulanova, G.Taylor, L.A., Bulanova, G., Snyder, G., Keller, R.Multiple inclusions in diamonds: evidence for complex petrogenesis7th International Kimberlite Conference Abstract, pp. 883-5.Russia, Siberia, YakutiaDiamond morphology, chemistry, inclusions, Deposit - Mir
DS2002-0678
2002
Bulanova, G.Hauri, E., Bulanova, G., Pearson, G., Griffin, B.Carbon and nitrogen isotope systematics in a sector zoned diamond from the Mir kimberlite, Yakutia.Eos, American Geophysical Union, Spring Abstract Volume, Vol.83,19, 1p.Russia, YakutiaGeochronology - diamond morphology, Deposit - Mir
DS200912-0453
2008
Bulanova, G.Longo, M., McCammon, C., Bulanova, G., Kaminsky, F.Iron oxidation state ( Mg.Fe)O calibration of the flank method on synthetic samples and application to natural inclusions in lower mantle diamonds.American Geological Union, Fall meeting Dec. 15-19, Eos Trans.Vol. 89, no.53, meeting supplement, 1p. abstractSouth America, Brazil, Mato GrossoPerovskite
DS201312-0108
2013
Bulanova, G.Bulanova, G.Platelet degradation in diamonds. Insights from infrared microscopy and implications for the thermal evolution of cratonic mantle.Goldschmidt 2013, AbstractMantleGeothermometry
DS201312-0109
2013
Bulanova, G.Bulanova, G.Diamonds and their inclusions from French Guiana: a record of Paleoproterozoic subduction.Goldschmidt 2013, AbstractSouth America, French GuianaDiamond inclusions
DS201312-0110
2013
Bulanova, G.Bulanova, G.An experimental investigation of the formation mechanisms of superdeep diamonds.Goldschmidt 2013, AbstractMantleGenesis
DS201412-0816
2014
Bulanova, G.Shiry, S., Hauri, E., Thomson, A., Bulanova, G., Smith, C., Kohn, S., Walter, M.Water content of stishovite, majorite and perovskite inclusions in Juin a superdeep diamonds.Goldschmidt Conference 2014, 1p. AbstractSouth America, BrazilDeposit - Juina
DS201705-0841
2017
Bulanova, G.Kohn, S., Speich, L., Smith, C., Bulanova, G.Developments in FTIR spectroscopy of diamonds and better constraints on diamond thermal histories.European Geosciences Union General Assembly 2017, Vienna April 23-28, 1p. 16438 AbstractAfrica, Zimbabwe, Australia, South America, BrazilDeposit - Murowa, Argyle, Machado River

Abstract: Fourier Transform Infrared (FTIR) spectroscopy is a commonly-used technique for investigating diamonds. It gives the most useful information if spatially-resolved measurements are used [1]. In this contribution we discuss the best way to acquire and present FTIR data from diamonds, using examples from Murowa (Zimbabwe), Argyle (Australia) and Machado River (Brazil). Examples of FTIR core-to-rim line scans, maps with high spatial resolution and maps with high spectral resolution that are fitted to extract the spatial variation of different nitrogen and hydrogen defects are presented. Model mantle residence temperatures are calculated from the concentration of A and B nitrogen-containing defects in the diamonds using known times of annealing in the mantle. A new, two-stage thermal annealing model is presented that better constrains the thermal history of the diamond and that of the mantle lithosphere in which the diamond resided. The effect of heterogeneity within the analysed FTIR volume is quantitatively assessed and errors in model temperatures that can be introduced by studying whole diamonds instead of thin plates are discussed. The kinetics of platelet growth and degradation will be discussed and the potential for two separate, kinetically-controlled defect reactions to be used to constrain a full thermal history of the diamond will be assessed. [1] Kohn, S.C., Speich, L., Smith, C.B. and Bulanova, G.P., 2016. FTIR thermochronometry of natural diamonds: A closer look.
DS201705-0881
2017
Bulanova, G.Tabassum, N., Kohn, S., Smith, C., Bulanova, G.The water concentations and OH in corporation mechanism of silicate inclusions in diamonds. What information do they provide?European Geosciences Union General Assembly 2017, Vienna April 23-28, 1p. 16735 AbstractAustralia, Canada, Russia, IndiaDiamond inclusions
DS201708-1605
2017
Bulanova, G.Bulanova, G.Natural diamond growth conditions recorded by their internal structure.11th. International Kimberlite Conference, PosterTechnologydiamond morphology
DS201908-1818
2019
Bulanova, G.Timmerman, S., Honda, M., Zhang, X., Jaques, A.L., Bulanova, G., Smith, C.B., Burnham, A.D.Contrasting noble gas compositions of peridotitic and eclogitic monocrystalline diamonds from the Argyle lamproite, Western Australia.Lithos, Vol. 344-345, pp. 193-206.Australiadeposit - Argyle

Abstract: He-Ne-Ar compositions were determined in diamonds from the Argyle lamproite, Western Australia, to assess whether subducted material affects the noble gas budget and composition of stable old sub-continental lithospheric mantle (SCLM). Twenty diamonds (both peridotitic and eclogitic) were characterized for their carbon isotopic compositions and N abundance and aggregation from which 10 eclogitic growth zones and 5 peridotitic growth zones were analysed for their He-Ne-Ar compositions. The eclogitic diamonds have ?13C values of ?4.7 to ?16.6‰ indicating a subduction signature, whereas the peridotitic diamonds have mantle-like compositions of ?4.0 to ?7.8‰. Mantle residence temperatures based on N-in-diamond thermometry showed that the eclogitic diamonds were mainly formed at 1260-1270?°C or above 1300?°C near the base of the lithosphere, whereas the peridotitic diamonds generally formed at lower temperatures (mostly 1135-1230?°C). A noble gas subduction signature is present to various extents in the eclogitic diamonds and is inferred from a hyperbolic mixing relationship between R/Ra and 4He and ?13C values concentrations with a predominance of low R/Ra values (<0.5; R/Ra?=?3He/4Hesample/3He/4Heair). In addition, low 40Ar/4He and 40Ar/36Ar ratios, high nucleogenic 21Ne/4He and low 3He/22Ne ratios are characteristic of subducted material and were found in the eclogitic diamonds. The peridotitic diamonds show generally higher R/Ra values (median 1.1?±?1.1) and lower 4He/40Ar ratios compared to eclogitic diamonds (median 0.1?±?0.8 R/Ra; with 7/10 samples having an average of 0.13?±?0.14 R/Ra). The studied peridotitic diamond growth zones showed a negative correlation between R/Ra and 4He concentrations over 2 orders of magnitude and limited variation in 3He, that can be largely explained by radiogenic 4He ingrowth. At low 4He concentrations the R/Ra value is around 2.8 for both paragenesis of diamonds and is significantly lower than present-day SCLM values, suggesting (1) a more radiogenic helium isotope composition beneath the Halls Creek Orogen than those for typical SCLM from other cratons and/or (2) that the peridotitic diamonds are formed from fluids that also had a subduction input. The high mantle residence temperature and low R/Ra value in the core and low temperature and higher R/Ra value in the rim of a single peridotitic diamond indicate multiple growth events and that part of the lherzolitic diamond population may be genetically related to the eclogitic diamonds. Combining the diamond mantle residence temperatures with noble gas compositions shows that noble gas subduction signatures are present at the base of the lithosphere below 180?km depth beneath Argyle and that fluid migration and interaction with the SCLM occurred over scales of at least 15?km, between 180 and 165?km depth.
DS1980-0078
1980
Bulanova, G.P.Bulanova, G.P., Nikishov, K.N., et al.The Composition of Garnets and Chromites Associated with Diamonds.Tsnigri, No. 153, PP. 79-89.RussiaBlank
DS1980-0079
1980
Bulanova, G.P.Bulanova, G.P., Shestakova, O.E., Leskova, N.V.Djerfisherite in Sulfide Inclusions from DiamondDoklady Academy of Science USSR, Earth Science Section., Vol. 255, No. 1-6, PP. 158-161.Russia, YakutiaMineralogy
DS1981-0251
1981
Bulanova, G.P.Kovalskiy, V.V., Bulanova, G.P., et al.Composition of Garnet Chromite and Rutile Associated with Diamond from Some Kimberlite Pipes in Yakutia.Doklady Academy of Science USSR, Earth Science Section., Vol. 247, No. 1-6, PP. 166-170.RussiaPetrology
DS1982-0124
1982
Bulanova, G.P.Bulanova, G.P., Shestakova, O.E.Sulfide Inclusions in DiamondsZap.vses. Mineral. Obshch., Vol. 111, No. 5, PP. 557-562.RussiaMineralogy
DS1985-0093
1985
Bulanova, G.P.Bulanova, G.P., Argunov, K.P.Potassium feldspar inclusions in diamond crystal from the Mirkimberlitepipe. (Russian)Doklady Academy of Sciences Akademy Nauk SSSR.(Russian), Vol. 284, No. 4, pp. 953-956RussiaDiamond Morphology
DS1985-0094
1985
Bulanova, G.P.Bulanova, G.P., Argunov, K.P.Potassium Feldspar Inclusions in Diamond Crystal from the Mir Kimberlite Pipe.Doklady Academy of Sciences Nauk SSSR., Vol. 284, No. 4, PP. 953-956.RussiaMir, Inclusions, Mineralogy
DS1986-0115
1986
Bulanova, G.P.Bulanova, G.P.Compositional evolution of syngenetic inclusions of ultrabasic association in Yakutian diamondsProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 371-373RussiaDiamond morphology
DS1986-0116
1986
Bulanova, G.P.Bulanova, G.P., Spetsius, Z.V.Paragenesis and pecularities of sulphides in diamonds and mantle xenoliths from kimberlitesProceedings of the Fourth International Kimberlite Conference, Held Perth, Australia, No. 16, pp. 374-376RussiaDiamond morphology
DS1987-0082
1987
Bulanova, G.P.Bulanova, G.P., Argunov, K.P.Potassic feldspar inclusions in a diamond crystal from the Mir pipeDoklady Academy of Science USSR, Earth Science Section, Vol. 284, No. 5, Publishing July 1987, pp. 158-161RussiaMineralogy
DS1987-0083
1987
Bulanova, G.P.Bulanova, G.P., Varshavskii, A.V., Leskova, N.V., Nikishova, L.V.Central inclusions as indicators of growth conditions of natural diamond.(Russian)Fiz. Svoistva I Mineral. Prirod. Almaza Yakutsk, (Russian), 1986 pp. 29-45RussiaDiamond inclusions
DS1987-0708
1987
Bulanova, G.P.Specius, Z., Bulanova, G.P.Native iron in Diamondiferous eclogites from the Udachnayakimberlitepipe.(Russian)Doklady Academy of Sciences Nauk. SSSR, (Russian), Vol. 294, No. 6, pp. 1445-1448RussiaEclogite, Xenolith
DS1988-0091
1988
Bulanova, G.P.Bulanova, G.P., Novgorodova, P.G., Pavlova, L.A.A 1st find of melt inclusion in diamond from Mir pipe.(Russian)Geochemistry International (Geokhimiya), (Russian), No. 5, pp. 756-765RussiaBlank
DS1988-0092
1988
Bulanova, G.P.Bulanova, G.P., Pavlova, L.P.Magnesite peridotite mineral association in a diamond from the Mir pipeDoklady Academy of Science USSR, Earth Science Section, Vol. 295, No. 1-6, Nov. pp. 176-179RussiaDiamond inclusions, Analyses
DS1988-0660
1988
Bulanova, G.P.Spetsius, Z.V., Bulanova, G.P.Native iron in diamond bearing eclogite from the Udachnaya kimberliteDoklady Academy of Science USSR, Earth Science Section, Vol. 294, No. 1-6, October pp. 144-146RussiaEclogite, Iron
DS1988-0661
1988
Bulanova, G.P.Spetsius, Z.V., Bulanova, G.P., Leskova, N.V.Djerfisherite and its genesis in kimberlitic rocksDoklady Academy of Science USSR, Earth Science Section, Vol. 293, No. 1-6, September pp. 133-136RussiaDjerfisherite
DS1989-0957
1989
Bulanova, G.P.Matsyuk, S.S., Platonov, A.N., Bulanova, G.P.Optical spectra of orange garnets included in diamonds. (Russian)Doklady Academy of Sciences Nauk. SSR, Ser. B., Geol. Khim Biol, (Russian), No. 5, pp. 15-18RussiaDiamond inclusion, Garnet analyses
DS1989-0958
1989
Bulanova, G.P.Matsyuk, S.S., Platonov, O.M., Bulanova, G.P.Optical spectra of orange garnet inclusions in diamonds.(Russian)Dopov. Akad. Nauk. Ukr. Ser. B., (Russian), No. 5, pp. 14-17RussiaDiamond morphology, Garnet inclusions
DS1990-0253
1990
Bulanova, G.P.Bulanova, G.P., Spetsius, Z.V.Inclusion in diamond and minerals of mantle xenoliths from kimberlites as A source of information on the upper mantle compositionInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 2, extended abstract p. 784-785RussiaDiamond morphology, Diamond inclusions
DS1990-0996
1990
Bulanova, G.P.Matsyuk, S.S., Bulanova, G.P., Platonov, A.N.Optical spectroscopic investigation of mineral inclusions from diamond and some problems of their genesis.(Russian)Mineral. Zhurn., (Russian), Vol. 12, No. 1, pp. 3-14RussiaDiamond inclusions, Mineralogy
DS1990-1122
1990
Bulanova, G.P.Novogordov, P.G., Bulanova, G.P., Pavlova, L.A., et al.Inclusions of potassium phases, coesite and omphacitein a coated diamond crystal from the Mir pipeDoklady Academy of Sciences Nauk. SSSR, (Russian), Vol. 310, No. 2, pp. 439-443RussiaDiamond morphology, Coesite
DS1990-1405
1990
Bulanova, G.P.Spetsius, Z.V., Bulanova, G.P.First find of sulphides in contact with diamonds in eclogite xenoliths From the Udachnaya pipeDoklady Academy of Sciences USSR, Earth Sci. Section, Vol. 306, No. 3, pp. 83-87RussiaDiamond inclusions, Sulphides
DS1991-0192
1991
Bulanova, G.P.Bulanova, G.P.Natural diamonds growth conditions according to the mineral inclusionsstudyProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 486-487RussiaDiamond morphology, Diamond inclusions
DS1991-0193
1991
Bulanova, G.P.Bulanova, G.P., Pavlova, L.A.The evolution of natural diamond growth conditionsProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 488-489RussiaDiamond morphology, Natural Diamond inclusions
DS1991-0194
1991
Bulanova, G.P.Bulanova, G.P., Zayskina, N.V.The graphite cohenite native iron association in the central part of adiamond from the '23 Party Congress Pipe.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 317, No. 3, pp. 706-710RussiaMineralogy, Diamond inclusion
DS1991-1243
1991
Bulanova, G.P.Novgorodov, P.G., Bulanova, G.P., Pavlova, L.A., Mikhaylov, V.N.Inclusions of potassic phases coesite and omphacite in a coated diamondDoklady Academy of Sciences USSR Earth Science Scetion, Vol. 310, No. 1-6, September pp. 147-150RussiaDiamond morphology, Coesite, omphacite
DS1993-0186
1993
Bulanova, G.P.Bulanova, G.P., et al.Solid inclusions in the rock forming minerals of deep xenoliths from Mirand Obnazhennaya pipes.(Russian)Mineralog. Zhurnal, (Russian), Vol. 15, No. 3, pp. 25-32.Russia, YakutiaDiamond inclusions, Deposits - Mir, Obnazhennaya
DS1993-0187
1993
Bulanova, G.P.Bulanova, G.P., Zayakina, N.V.A graphite cohenite iron mineral association in the core of a diamond From the Twenty Third Soviet Communist Party Congress PipeDoklady Academy of Sciences USSR, Earth Science Section, Vol. 317 A February Publishing date pp. 126-130Russia, YakutiaMineral inclusion, Deposit -Twenty Third
DS1993-1346
1993
Bulanova, G.P.Rudnick, R.L., Eldridge, C.S., Bulanova, G.P.Diamond growth history from in situ measurement of lead and S isotopic compositions of sulfide inclusions.Geology, Vol. 21, No. 1, January pp. 13-16.Russia, YakutiaGeochronology, Diamond inclusions
DS1994-1671
1994
Bulanova, G.P.Spetsius, Z.V., Bulanova, G.P., Griffin, W.L.Eclogite containing diamond with a garnet inclusion from the Mir pipeDoklady Academy of Sciences Acad. Science USSR, Vol. 323, No. 2, June pp. 115-119.Russia, YakutiaEcologite, diamond inclusions, Deposit -Mir
DS1995-0228
1995
Bulanova, G.P.Bulanova, G.P.The origin of diamond (1995)Journal of Geochemical Exploration, Vol. 52, pp. 1-25.Russia, YakutiaDiamond genesis, macrodiamonds, eclogites, peridotites, Geochemistry
DS1995-0229
1995
Bulanova, G.P.Bulanova, G.P., Griffin, B.J.The origin of complex agate textures in octahedral diamonds fromkimberlites.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 74-76.Russia, YakutiaDiamond morphology, Deposit -Mir, Aikal
DS1995-0230
1995
Bulanova, G.P.Bulanova, G.P., Milledge, H.J.Origin and history of growth of macrodiamonds from Yakutian kimberlitesProceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 77-79.Russia, YakutiaDiamond morphology, Deposit -Mir, 23rd. Udachnaya
DS1995-0681
1995
Bulanova, G.P.Griffin, B.J., Bulanova, G.P., Taylor, W.R.Chlorine and FTIR mapping of nitrogen content and hydrogen distribution in a diamond from the Mir pipe -growth.Proceedings of the Sixth International Kimberlite Conference Extended, p. 191-93.GlobalDiamond morphology, Deposit -Mir
DS1995-1251
1995
Bulanova, G.P.Milledge, H.J., Bulanova, G.P., Taylor, W.R., Woods, P.A.Internal morphology of Yakutian diamonds - a cathodluminescence And infrared mapping study.Proceedings of the Sixth International Kimberlite Conference Abstracts, pp. 384-386.Russia, YakutiaDiamond morphology, Cathodluminescence
DS1996-0191
1996
Bulanova, G.P.Bulanova, G.P., Griffin, W.L., Barnes, S-J.Trace elements in sulfide inclusions from Yakutian diamondsContributions to Mineralogy and Petrology, Vol. 124, No. 2, pp. 111-125.Russia, YakutiaSulphide inclusions, Diamond morphology
DS1997-0892
1997
Bulanova, G.P.Pavlova, L.A., Bulanova, G.P.The investigation of diamonds employing X-Ray microanalysisGeoanalysis 97 abstract volume, June Vail, Colorado, p. 74.Russia, SiberiaDiamond inclusions
DS1998-0184
1998
Bulanova, G.P.Bulanova, G.P., Griffin, W.L., Kaminsky, F.V., DaviesDiamonds from Zarnitsa and Dalnaya kimberlites: their nature, growthhistory, lithospheric mantle source.7th International Kimberlite Conference Abstract, pp. 113-5.Russia, YakutiaDiamond morphology, Deposit - Zarnitsa, Dalnaya
DS1998-0185
1998
Bulanova, G.P.Bulanova, G.P., Griffin, W.L., Ryan, C.G.Nucleation environment of diamonds from Yakutian kimberlitesMineralogical Magazine, Vol. 62, No. 3, June pp. 409-20.Russia, YakutiaDiamond morphology
DS1998-0186
1998
Bulanova, G.P.Bulanova, G.P., Shelkov, D.Nature of eclogitic diamonds from Yakutian kimberlites: evidence from isotopic composition and sulphide inclus.7th International Kimberlite Conference Abstract, pp. 116-8.Russia, YakutiaDiamond nature, origin, genesis, Deposit - Mir, 23rd Party Congress
DS1998-0596
1998
Bulanova, G.P.Hauri, E.H., Pearson, D.G., Bulanova, G.P., Milledge, H.Microscale variations in Carbon and Nitrogen isotopes within mantle diamonds revealed by SIMS.7th International Kimberlite Conference Abstract, pp. 317-9.Russia, Siberia, southern AfricaDiamond morphology, Geochronology
DS1998-1481
1998
Bulanova, G.P.Trautman, R.L., Griffin, B.J., Bulanova, G.P.Growth features and nitrogen aggregation properties of microdiamonds derived from kimberlitic diatremes.7th International Kimberlite Conference Abstract, pp. 926-8.Russia, Australia, Brazil, Finland, South AfricaCathodluminescence data, Micro diamonds
DS2002-0221
2002
Bulanova, G.P.Bulanova, G.P., Pearson, D.G., Hauri, E.H., Griffin, B.J.Carbon and nitrogen isotope systematics within a sector growth diamond from the Mir kimberlite, Yakutia.Chemical Geology, Vol. 188, No. 1-2, pp. 105-123.Russia, YakutiaGeochronology, Deposit - Mir
DS2002-0681
2002
Bulanova, G.P.Hauri, E.H., Wang, J., Pearson, D.G., Bulanova, G.P.Microanalysis of 13C 15 N and N abundances in diamonds by secondary ion mass spectrometry.Chemical Geology, Vol.145, 1-2, Apr.15, pp. 149-63.Russia, SiberiaDiamond - inclusions, carbon, nitrogen isotopes
DS2003-0026
2003
Bulanova, G.P.Araujo, D.P., Gaspar, J.C., Fei, Y., Hauri, E.H., Hemley, R., Bulanova, G.P.Mineralogy of diamonds from the Juin a Province, Brazil8ikc, Www.venuewest.com/8ikc/program.htm, Session 3, POSTER abstractBrazilDiamonds
DS2003-0182
2003
Bulanova, G.P.Bulanova, G.P., Muchemwa, E., Pearson, D.G., Griffin, B.J., Kelly, S., KlemmeSyngenetic inclusions of yeminite in diamond from Sese kimberlite ( Zimbabwe) -8ikc, Www.venuewest.com/8ikc/program.htm, Session 3, POSTER abstractZimbabweDiamonds - inclusions, Deposit - Sese
DS2003-0183
2003
Bulanova, G.P.Bulanova, G.P., Pearson, D.G., Hauri, E.H., Milledge, H.J., Barashkov, Yu.P.Dynamics of diamond growth: evidence from isotope and FTIR trends8ikc, Www.venuewest.com/8ikc/program.htm, Session 3, POSTER abstractRussiaDiamonds - inclusions, Geochronology, morphology
DS200412-0239
2004
Bulanova, G.P.Bulanova, G.P., Muchemwa, E., Pearson, D.G., Griffin, B.J., Kelley, S.P., Klemme, S., Smith, C.B.Syngenetic inclusions of yimengite in diamond from Sese kimberlite - evidence for metasomatic conditions of growth.Lithos, Vol. 77, 1-4, Sept. pp. 181-192.Africa, ZimbabweMagnetoplumbite, grochronology argon, mantle, metasomat
DS200612-0195
2005
Bulanova, G.P.Bulanova, G.P., Varshavsky, A.V., Kotegov, V.A.A venture into the interior of natural diamond genetic information and implications for the gem industry. Part 1, the main types of internal growth structures.Journal of Gemmology, Vol. 29, 7/8, pp. 377-386.RussiaTechnology
DS200812-0631
2007
Bulanova, G.P.Lang, A.R., Bulanova, G.P., Fisher, D., Fukert, S., Saruna, A.Defects in a mixed habit Yakutian diamond: studies by optical and cathodluminescence microscopy, infrared absorption, Raman Scattering and photoluminesence spectJournal of Crystal Growth, Vol. 309, 2, pp. 170-180.TechnologySpectroscopy
DS200812-1196
2008
Bulanova, G.P.Ushkov, V.V., Ustinov, V.N., Smith, C.B., Bulanova, G.P., Lukyanova, L.I., Wiggers de Vries, D., PearsonKimozero, Karelia: a Diamondiferous paleoproterozoic metamorphosed volcaniclastic kimberlite.9IKC.com, 3p. extended abstractRussia, KareliaDeposit - Kimozero
DS200912-0395
2009
Bulanova, G.P.Kohn, S.C., Bulanova, G.P.Growth of diamonds in subduction zones? Evidence from zoning of nitrogen defects.Goldschmidt Conference 2009, p. A676 Abstract.MantleSubduction
DS200912-0459
2009
Bulanova, G.P.Luguet, A., Jaques, A.I., Pearson, D.G., Smith, C.B., Bulanova, G.P., Roffey, S.L., Rayner, M.J., Lorand, J.P.An integrated petrological, geochemical and Re-Os isotope study of peridotite xenoliths from the Argyle lamproite, western Australia and implications forLithos, In press available, 64p.AustraliaGeochronology - Cratonic diamond occurrences
DS200912-0702
2009
Bulanova, G.P.Smith, C.B., Bulanova, G.P., Kohn, S.C., Milledge, H.J., Hall, A.E., Griffin, B.J., Pearson, D.G.Nature and genesis of Kalimantan diamonds.Lithos, In press available, 38p.Indonesia, KalimantanAlluvials, diamond morphology
DS200912-0703
2009
Bulanova, G.P.Smith, C.B., Pearson, D.G., Bulanova, G.P., Beard, A.D., Carlson, R.W., Wittig, N., Sims, K., Chimuka, L., Muchemwa, E.Extremely depleted lithospheric mantle and diamonds beneath the southern Zimbabwe Craton.Lithos, In press available, 41p.Africa, ZimbabweDeposit - Murowa, Sese
DS200912-0805
2009
Bulanova, G.P.Walter, 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
DS201012-0079
2010
Bulanova, G.P.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
DS201012-0848
2010
Bulanova, G.P.Wiggers de Vries, D.F., Drury, M.R., De Winter, D.A.M., Bulanova, G.P., Pearson, D.G., Davies, G.R.Three dimensional cathodluminescence imaging and electron backscatter diffraction: tools for studying the genetic nature of diamond inclusions.Contributions to Mineralogy and Petrology, in press available, 15p.TechnologyDiamond inclusions
DS201112-0231
2011
Bulanova, G.P.Wiggers de Vries, D.F., Drury, M.R., de Winter, D.A.M., Bulanova, G.P., Pearson, D.G., Davies, G.R.Three dimensional cathodluminescence imaging and electron backscatter diffraction: tools for studying the genetic nature of diamond inclusions.Contributions to Mineralogy and Petrology, Vol. 161, 4, pp. 565-579.RussiaDeposit - Udachnaya
DS201112-0533
2011
Bulanova, G.P.Kohn, S.C., Walter, M.J., Araujo, D., Bulanova, G.P., Smith, C.B.Subducted oceanic crust exhumed from the lower mantle.Goldschmidt Conference 2011, abstract p.1213.South America, BrazilJuina diamonds
DS201212-0017
2012
Bulanova, G.P.Arajo, D.P., Bulanova, G.P., Walter, M.J., Kohn, S.C., Smith, C.B., Gaspar, J.C., WangJuina-5 kimberlite ( Brazil): a source of unique lower mantle diamonds.10th. International Kimberlite Conference Feb. 6-11, Bangalore India, AbstractSouth America, BrazilDeposit - Juina-5
DS201212-0096
2012
Bulanova, G.P.Bulanova, G.P., Marks, A., Smith, C.B., Kohn, S.C., Walter, M.J., Gaillou, E., Shiry, S.B., Trautman, R., Griffin, B.J.Diamonds from Sese and Murowa kimberlites ( Zimbabwe) - evidence of extreme peridotitic lithosphere depletion and Ti-REE metasomatism.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractAfrica, ZimbabweDeposit - Sese, Murowa
DS201212-0097
2012
Bulanova, G.P.Bulanova, G.P., Wiggers de Vries, D.F., Beard, A., Pearson, D.G., Mikhail, S.S., Smelov, A.P., Davies, G.R.Two stage origin of eclogitic diamonds recorded by a single crystal from the Mir pipe, Yakutia.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractRussia, YakutiaDeposit - Mir
DS201212-0367
2012
Bulanova, G.P.Kohn, S.C., McKay, A.P., Smith, C.B., Bulanova, G.P., Walter, M.J., Marks, A.The thermal history of Archean lithosphere. Constraints from FTIR studies of zoning in diamonds.emc2012 @ uni-frankfurt.de, 1p. AbstractAfrica, ZimbabweDeposit - Murowa
DS201212-0674
2012
Bulanova, G.P.Smith, C.B., Bulanova, G.P., Presser, J.L.B.Diamonds from Capibary, Paraguay10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractSouth America, ParaguayDeposit - Itapapoty
DS201212-0675
2012
Bulanova, G.P.Smith, C.B., Bulanova, G.P., Walter, M.U., Kohn, S.C., Mikhail, S., Gobbo, L.Origin of diamonds from the Dachine ultramafic, French Guyana.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractSouth America, French GuianaDeposit - Dachine
DS201212-0728
2012
Bulanova, G.P.Thomson, A.R., Walter, M.J., Kohn, S.C., Russell, B.C., Bulanova, G.P., Araujo, D., Smith, C.B.Evidence for the role of carbonate melts in the origin of superdeep diamond inclusions from the Juina-5 kimberlite, Brazil.Goldschmidt Conference 2012, abstract 1p.South America, BrazilDeposit - Juina-5
DS201312-0024
2013
Bulanova, G.P.Arajuo, D.P., Gaspar, J.C., Bulanova, G.P.Juin a diamonds from kimberlites and alluvials: a omparison of morphology, spectral characteristics and carbon isotope composition.Proceedings of the 10th. International Kimberlite Conference, Vol. 1, Special Issue of the Journal of the Geological Society of India,, Vol. 1, pp. 255-269.South America, BrazilDeposit - Juina
DS201312-0111
2013
Bulanova, G.P.Burnham, A.D., Kohn, S.C., Potoszil, C., Walter, M.J., Bulanova, G.P., Thomson, A.R., Smith, C.B.The redox state of diamond forming fluids: constraints from Fe3/Fe2+ of garnets.Goldschmidt 2013, AbstractMantleGeothermometry
DS201312-0495
2013
Bulanova, G.P.Kohn, S.C., Wibberley, E., Smith, C.B., Bulanova, G.P., Walter, M.J.Platelet degradation in diamonds. Insights from infrared microscopy and implications for the thermal evolution of cratonic mantle.Goldschmidt 2013, AbstractMantleDiamond crystallography
DS201312-0817
2013
Bulanova, G.P.Shirey, S.B., Hauri, E.H., Thomason, A.R., Bulanova, G.P., Smith, C.B., Kohn, S.C., Walter, M.J.Water content of inclusions in superdeep diamonds.Goldschmidt 2013, 1p. AbstractSouth America, BrazilDeposit - Collier4
DS201312-0912
2013
Bulanova, G.P.Thomson, A.R., Walter, M.J., Kohn, S.C., Bulanova, G.P., Smith, C.B.An experimental investigation of the formation mechanisms of superdeep diamonds.Goldschmidt 2013, 1p. AbstractSouth America, BrazilDeposit - Collier 4, Juina5
DS201312-0949
2013
Bulanova, G.P.Walter, M.J., Smith, C.B., Bulanova, G.P., Mikhail, S., Khon, S.C.Diamonds and their inclusions from Dachine, French Guiana: a record of Paleoproterozoic subduction.Goldschmidt 2013, 1p. AbstractSouth America, French GuianaDeposit - Dachine
DS201312-0970
2013
Bulanova, G.P.Wiggers de Vries, D.F., Pearson, D.G., Bulanova, G.P., Smelov, A.P., Pavlushin, A.D., Davies, G.R.Re-Os dating of sulphide inclusions zonally distributed in single Yakutian diamonds: evidence for multiple episodes of Proterozoic formation and protracted timescales of diamond growth.Geochimica et Cosmochimica Acta, Vol. 120, pp. 363-394.Russia, YakutiaDeposit - Mir, 23, Udachnaya
DS201412-0032
2014
Bulanova, G.P.Baez Presser, J.L., Bulanova, G.P., Smith, C.B.Diamantes de Capiibary, DPTO. Dan Pedro, Paraguay.Boletin del Museo Nacional de Historia Narural del Paraguay, Vol. 18, 1, June, pp. 5-23.South America, ParaguayAlluvials, diamonds
DS201412-0082
2014
Bulanova, G.P.Bulanova, G.P., Wiggers de Vries, D.F., Pearson, D.G., Beard, A., Mikhail, S., Smelov, A.P., Davies, G.R.An eclogitic diamond from Mir pipe (Yakutia), recording two growth events from different isotopic sources.Chemical Geology, Vol. 381, pp. 40-54.Russia, YakutiaDeposit - Mir
DS201412-0712
2014
Bulanova, G.P.Presser, J.L.B., Bulanova, G.P., Smith, C.B.Diamantes de Capiibary, DPTO. San Pedro, Paraguay.Boletin del Museo Nacional de Historia Narural del Paraguay, Vol. 17, 2, pp. 5-23.South America, ParaguayProject - Capiibary
DS201412-0930
2014
Bulanova, G.P.Thomson, A.R., Kohn, S.C., Bulanova, G.P., Smith, C.B., Araujo, D., Walter, M.J.Origin of sub-lithopheric diamonds from the Juina-5 kimberlite ( Brazil): constraints from carbon isotopes and inclusion compositions.Contributions to Mineralogy and Petrology, Vol. 168, pp. 1081-1091.South America, BrazilDeposit - Juina-5
DS201502-0113
2014
Bulanova, G.P.Thomson, A.R., Kohn, S.C., Bulanova, G.P., Smith, C.B., Araujo, D., EMIF, Walter, M.J.Origin of sub-lithospheric diamonds from the Juina-5 kimberlite ( Brazil): constraints from carbon isotopes and inclusion compositions.Contributions to Mineralogy and Petrology, Vol. 168, pp. 1081-1110.South America, BrazilDeposit - Juina-5
DS201512-1900
2015
Bulanova, G.P.Burnham, A.D., Thomson, A.R., Bulanova, G.P., Kohn, S.C., Smith, C.B., Walter, M.J.Stable isotope evidence for crustal recycling as recorded by superdeep diamonds.Earth and Planetary Science Letters, Vol. 432, pp. 374-380.South America, BrazilDeposit - Juina-5, Collier-4, Machado River

Abstract: Sub-lithospheric diamonds from the Juina-5 and Collier-4 kimberlites and the Machado River alluvial deposit in Brazil have carbon isotopic compositions that co-vary with the oxygen isotopic compositions of their inclusions, which implies that they formed by a mixing process. The proposed model for this mixing process, based on interaction of slab-derived carbonate melt with reduced (carbide- or metal-bearing) ambient mantle, explains these isotopic observations. It is also consistent with the observed trace element chemistries of diamond inclusions from these localities and with the experimental phase relations of carbonated subducted crust. The 18O-enriched nature of the inclusions demonstrates that they incorporate material from crustal protoliths that previously interacted with seawater, thus confirming the subduction-related origin of superdeep diamonds. These samples also provide direct evidence of an isotopically anomalous reservoir in the deep (?350 km) mantle.
DS201608-1396
2016
Bulanova, G.P.Burnham, A.D., Bulanova, G.P., Smith, C.B., Whitehead, S.C., Kohn, S.C., Gobbo, L., Walter, M.J.Diamonds from the Machado River alluvial deposit, Rondona, Brazil, derived from both lithospheric and sublithospheric mantle.Lithos, in press available, 15p.South America, BrazilMorphology, textures, chemistry

Abstract: Diamonds from the Machado River alluvial deposit have been characterised on the basis of external morphology, internal textures, carbon isotopic composition, nitrogen concentration and aggregation state and mineral inclusion chemistry. Variations in morphology and features of abrasion suggest some diamonds have been derived directly from local kimberlites, whereas others have been through extensive sedimentary recycling. On the basis of mineral inclusion compositions, both lithospheric and sublithospheric diamonds are present at the deposit. The lithospheric diamonds have clear layer-by-layer octahedral and/or cuboid internal growth zonation, contain measurable nitrogen and indicate a heterogeneous lithospheric mantle beneath the region. The sublithospheric diamonds show a lack of regular sharp zonation, do not contain detectable nitrogen, are isotopically heavy (?13CPDB predominantly ? 0.7 to ? 5.5) and contain inclusions of ferropericlase, former bridgmanite, majoritic garnet and former CaSiO3-perovskite. This suggests source lithologies that are Mg- and Ca-rich, probably including carbonates and serpentinites, subducted to lower mantle depths. The studied suite of sublithospheric diamonds has many similarities to the alluvial diamonds from Kankan, Guinea, but has more extreme variations in mineral inclusion chemistry. Of all superdeep diamond suites yet discovered, Machado River represents an end-member in terms of either the compositional range of materials being subducted to Transition Zone and lower mantle or the process by which materials are transferred from the subducted slab to the diamond-forming region.
DS201610-1913
2016
Bulanova, G.P.Thomson, A.R., Kohn, S.C., Bulanova, G.P., Smith, C.B., Araujo, D., Walter, M.J.Trace element composition of silicate inclusions in sub-lithospheric diamonds from the Juina-5 kimberlite: evidence for diamond growth from slab melts.Lithos, in press available 17p.South America, BrazilDeposit - Juina-5

Abstract: The trace element compositions of inclusions in sub-lithospheric diamonds from the Juina-5 kimberlite, Brazil, are presented. Literature data for mineral/melt partition coefficients were collated, refitted and employed to interpret inclusion compositions. As part of this process an updated empirical model for predicting the partitioning behaviour of trivalent cations for garnet-melt equilibrium calibrated using data from 73 garnet-melt pairs is presented. High levels of trace element enrichment in inclusions interpreted as former calcium silicate perovskite and majoritic garnet preclude their origin as fragments of an ambient deep mantle assemblage. Inclusions believed to represent former bridgmanite minerals also display a modest degree of enrichment relative to mantle phases. The trace element compositions of ‘NAL’ and ‘CF phase’ minerals are also reported. Negative Eu, Ce, and Y/Ho anomalies alongside depletions of Sr, Hf and Zr in many inclusions are suggestive of formation from a low-degree carbonatitic melt of subducted oceanic crust. Observed enrichments in garnet and ‘calcium perovskite’ inclusions limit depths of melting to less than ~ 600 km, prior to calcium perovskite saturation in subducting assemblages. Less enriched inclusions in sub-lithospheric diamonds from other global localities may represent deeper diamond formation. Modelled source rock compositions that are capable of producing melts in equilibrium with Juina-5 ‘calcium perovskite’ and majorite inclusions are consistent with subducted MORB. Global majorite inclusion compositions suggest a common process is responsible for the formation of many superdeep diamonds, irrespective of geographic locality. Global transition zone inclusion compositions are reproduced by fractional crystallisation from a single parent melt, suggesting that they record the crystallisation sequence and melt evolution during this interaction of slab melts with ambient mantle. All observations are consistent with the previous hypothesis that many superdeep diamonds are created as slab-derived carbonatites interact with peridotitic mantle in the transition zone.
DS201611-2123
2016
Bulanova, G.P.Kohn, S.C., Speich, L., Smith, C.B., Bulanova, G.P.FTIR thermochronometry of natural diamonds: a closer look.Lithos, in press available 34p.Africa, Zimbabwe, Australia, South America, BrazilDeposit - Murowa, Argyle, Machado River

Abstract: Fourier Transform Infrared (FTIR) spectroscopy is a commonly-used technique for investigating diamonds, that gives the most useful information if spatially-resolved measurements are used. In this paper we discuss the best way to acquire and present FTIR data from diamonds, using examples from Murowa (Zimbabwe), Argyle (Australia) and Machado River (Brazil). Examples of FTIR core-to-rim line scans, maps with high spatial resolution and maps with high spectral resolution that are fitted to extract the spatial variation of different nitrogen and hydrogen defects are presented. Model mantle residence temperatures are calculated from the concentration of A and B nitrogen-containing defects in the diamonds using known times of annealing in the mantle. A new, two-stage thermal annealing model is presented that better constrains the thermal history of the diamond and that of the mantle lithosphere in which the diamond resided. The effect of heterogeneity within the analysed FTIR volume is quantitatively assessed and errors in model temperatures that can be introduced by studying whole diamonds instead of thin plates are discussed. The spatial distribution of VN3H hydrogen defects associated with the 3107 cm? 1 vibration does not follow the same pattern as nitrogen defects, and an enrichment of VN3H hydrogen at the boundary between pre-existing diamond and diamond overgrowths is observed. There are several possible explanations for this observation including a change in chemical composition of diamond forming fluid during growth or kinetically controlled uptake of hydrogen.
DS201611-2142
2016
Bulanova, G.P.Smith, C.B., Walter, M.J., Bulanova, G.P., Mikhail, S., Burnham, A.D., Gobbo, L., Kohn, S.C.Diamonds from Dachine, French Guiana: a unique record of Early Proterozoic subduction.Lithos, in press available 66p.South America, French GuianaDeposit - Dachine

Abstract: Diamonds from Dachine, French Guiana, are unique among worldwide diamond populations. The diamonds were transported to the surface in an unusual ultramafic extrusive magma with an affinity to boninite or komatiite, which was emplaced within an arc geological setting at ~ 2.2 Ga. Dachine diamonds have internal and external morphologies indicative of relatively rapid growth from carbon oversaturated fluids or melts, and exhibit internal features consistent with residence in a high-strain environment. On the basis of nitrogen (N) defects the diamonds are categorized as Type Ib-IaA. The unusually low aggregation state of N places severe constraints on the thermal history of the diamonds, effectively ruling out derivation in convecting mantle. The carbon and N isotopic compositions of Dachine diamonds are consistent with a sedimentary source of carbon, with the majority of diamonds having ?13C values < ? 25‰ and ?15N values > + 4‰. The primary carbon was presumably deposited on an early Proterozoic seafloor. Sulphide inclusions have low Ni and Cr and are comparable to lithospheric eclogitic-type sulphide inclusions. Three garnet and one clinopyroxene inclusion are also eclogitic in composition, and one garnet inclusion has a majorite component indicating an origin around 250 km depth. The silicate inclusions are highly depleted in many incompatible trace elements (e.g. LREE, Nb, Hf, Zr), and modelling indicates an eclogitic source lithology that contained a LREE-enriched trace phase such as epidote or allanite, and an HFSE-rich phase such as rutile. Four of the five inclusions are unusually enriched in Mn, as well as Ni and Co, and modelling indicates a protolith with the bulk composition of subducted normal MORB plus about 10% ferromanganese crust component. We suggest a model wherein Dachine diamonds precipitated from remobilized sedimentary carbon at the slab-mantle interface from liquids derived ultimately by deserpentinization of slab peridotite at depths of ~ 200 to 250 km. These fluids may also trigger melting in wedge peridotite, resulting in a volatile-rich ultramafic melt that transports the diamonds rapidly to the surface. The process of diamond formation and exhumation from the slab mantle interface likely occurred in a Paleoproterozoic subduction zone and over a very limited timespan, likely less than a million years.
DS201803-0478
2017
Bulanova, G.P.Speich, L., Kohn, S.C., Wirth, R., Bulanova, G.P., Smith, C.B.The relationship between platelet size and the B' infrared peak of natural diamonds revisited. Type 1aLithos, Vol. 278-281, pp. 419-426.Technologydiamond morphology

Abstract: Platelets in diamond are extended planar defects that are thought to be generated during the nitrogen aggregation process in type Ia diamonds. They were subjected to intensive research during the 1980s and 1990s but the techniques used for observation of defects in diamond have improved since that time and new insights can be gained by further study. This study combines high resolution Fourier Transform Infrared (FTIR) analysis, with an emphasis on the main platelet peak, and transmission electron microscopic (TEM) imaging. By performing TEM and FTIR analyses on volumes of diamond that were closely spatially related it is shown that the average platelet diameter, D, follows the relationship D=ax?b where x is the position of the platelet peak in the infrared spectrum, a is a constant and b is the minimum position of the platelet peak. The best fit to the data is obtained if a value of b=1360cm?1 is used, giving a fitted value of a=221. The observed variation in infrared (IR) peak width can also be explained in terms of this relationship. Additionally, platelet morphology was found to vary according to diameter with large platelets being more elongated. The tendency to become more elongated can be described by the empirical equation AR=11.9D+19.6+0.4 where AR is the aspect ratio. Using the relationships established here, it will be possible to study platelet abundance and size as a function of parameters such as nitrogen concentration, nitrogen aggregation and diamond residence time in the mantle. This work therefore will open up new methods for constraining the geological history of diamonds of different parageneses and from different localities.
DS201809-2050
2018
Bulanova, G.P.Kohn, S.C., Speich, L., Bulanova, G.P., Smith, C.B., Gress, M.U., Davies, G.R.Modelling the temperature history of mantle lithosphere using FTIR maps of diamonds.Goldschmidt Conference, 1p. AbstractAfrica, Zimbabwe. Australia, Canada, Northwest Territories, South Africa, Botswanadeposit - Murowa, Argyle, Diavik, Venetia, Orapa

Abstract: FTIR maps of diamond plates, cut through the centre of growth, contain abundant information about changing defect concentrations from core to rim. These data can, in principle, be interpreted in terms of the variation in conditions of diamond growth and the temperatures experienced by the diamond during the period of mantle residence between growth and exhumation. Many diamonds show multiple growth zones that can be observed by cathodoluminescence. Importantly, the combination of nitrogen concentration and nitrogen aggregation measured by FTIR can be used to determine whether the growth zones are of similar or very different ages (Kohn et al., 2016). In this study, we use automated fitting of several thousand individual spectra within each FTIR map to define a model temperature for each pixel using the Python program, QUIDDIT. We then use a two-stage aggregation model to constrain potential temperature-time histories for each diamond. To take full advantage of the temperature history recorded by zoned diamonds, radiometric ages of inclusions are required. If the growth ages of each zone and the date of exhumation are well-known, then a model temperature can be calculated for each zone. The combination of zone-specific ages and improved quality and processing of FTIR spectra is able to provide unique new insights into the thermal history of diamondbearing lithospheric mantle. For the first time we will be able to use the N defects in diamonds to work out whether a particular location in the lithosphere has heated or cooled over long periods of geological time. The implications for the mechanism of formation of lithosphere will be discussed. We will illustrate the approach using examples of zoned diamonds from Murowa (Zimbabwe), Argyle (Australia), Diavik (Canada), Venetia (South Africa) and Orapa (Botswana).
DS201812-2784
2018
Bulanova, G.P.Bulanova, G.P., Smith, C.B., Pearson, D.G., Kohn, S.C., Davy, A.T., McKay, A., Marks, A.Murowa deposit: Diamonds from the Murowa kimberlites: formation within extremely depleted and metasomatized Zimbabwean peridotitic subcontinental mantle.Society of Economic Geology Geoscience and Exploration of the Argyle, Bunder, Diavik, and Murowa Diamond Deposits, Special Publication no. 20, pp. 425-Africa, Zimbabwedeposit - Murowa
DS201812-2785
2018
Bulanova, G.P.Bulanova, G.P., Speich, L. Smith, C.B., Gaillou, E., Koln, S.C., Wibberley, E., Chapman, J.G., Howell, D., Davy, A.T.Argyle deposit: The unique nature of Argyle fancy diamonds: internal structure, paragenesis, and reasons for color.Society of Economic Geology Geoscience and Exploration of the Argyle, Bunder, Diavik, and Murowa Diamond Deposits, Special Publication no. 20, pp. 169-190.Australia, western Australiadeposit - Argyle
DS201812-2860
2018
Bulanova, G.P.Pearson, D.G., Liu, J., Smith, C.B., Mather, K.A., Krebs, M.Y., Bulanova, G.P., Kobussen, A.F.Murowa deposit: Characteristics and origin of the mantle root beneath the Murowa diamond mine: implications for craton and diamond formation.Society of Economic Geology Geoscience and Exploration of the Argyle, Bunder, Diavik, and Murowa Diamond Deposits, Special Publication no. 20, pp. 403-424.Africa, Zimbabwedeposit - Murowa
DS201812-2886
2018
Bulanova, G.P.Smith, C.B., Bulanova, G.P., Kobussen, A.F., Burnham, A., Chapman, J.G., Davy, A.T., Sinha, K.K.Bunder deposit: Diamonds from the Atri South pipe, Bunder lamproite field, India, and implications for the nature of the underlying mantle.Society of Economic Geology Geoscience and Exploration of the Argyle, Bunder, Diavik, and Murowa Diamond Deposits, Special Publication no. 20, pp. 237-252.Indiadeposit - Bunder
DS201904-0781
2018
Bulanova, G.P.Speich, L., Kohn, S.C., Bulanova, G.P., Smith, C.B.The behaviour of platelets in natural diamonds and the development of a new mantle thermometer.Contributions to Mineralogy and Petrology, Vol. 173, pp. 39-GlobalFTIR

Abstract: Platelets are one of the most common defects occurring in natural diamonds but their behaviour has not previously been well understood. Recent technical advances, and a much improved understanding of the correct interpretation of the main infrared (IR) feature associated with platelets (Speich et al. 2017), facilitated a systematic study of platelets in 40 natural diamonds. Three different types of platelet behaviour were identified here. Regular diamonds show linear correlations between both B-centre concentrations and platelet density and also between platelet size and platelet density. Irregular diamonds display reduced platelet density due to platelet breakdown, anomalously large or small platelets and a larger platelet size distribution. These features are indicative of high mantle storage temperatures. Finally, a previously unreported category of subregular diamonds is defined. These diamonds experienced low mantle residence temperatures and show smaller than expected platelets. Combining the systematic variation in platelet density with temperatures of mantle storage, determined by nitrogen aggregation, we can demonstrate that platelet degradation proceeds at a predictable rate. Thus, in platelet-bearing diamonds where N aggregation is complete, an estimate of annealing temperature can now be made for the first time.
DS201909-2098
2019
Bulanova, G.P.Timmerman, S., Honda, M., Burnham, A.D., Amelin, Y., Woodland, S., Pearson, D.G., Jaques, A.L., Le Losq, C., Bennett, V.C., Bulanova, G.P., Smith, C.B., Harris, J.W., Tohver, E.Primordial and recycled helium isotope signatures in the mantle transition zone. Science, Vol. 365, 6454, pp. 692-694.Mantlediamond genesis

Abstract: Isotope compositions of basalts provide information about the chemical reservoirs in Earth’s interior and play a critical role in defining models of Earth’s structure. However, the helium isotope signature of the mantle below depths of a few hundred kilometers has been difficult to measure directly. This information is a vital baseline for understanding helium isotopes in erupted basalts. We measured He-Sr-Pb isotope ratios in superdeep diamond fluid inclusions from the transition zone (depth of 410 to 660 kilometers) unaffected by degassing and shallow crustal contamination. We found extreme He-C-Pb-Sr isotope variability, with high 3He/4He ratios related to higher helium concentrations. This indicates that a less degassed, high-3He/4He deep mantle source infiltrates the transition zone, where it interacts with recycled material, creating the diverse compositions recorded in ocean island basalts.
DS1990-0254
1990
Bulashevich, Yu.P.Bulashevich, Yu.P., Khachay, Yu.V.Mechanism of convection in the upper mantle of the earthDoklady Academy of Science USSR, Earth Science Section, Vol. 305, No. 2, Sept. pp. 1-4RussiaMantle, Experimental
DS200912-0075
2009
Bulato, V.K.Brey, G.P., Bulato, V.K., Girnis, A.V.Influence of water and fluorine on melting of carbonated peridotite at 6 and 10 GPa.Lithos, In press availableMantleMelting
DS1991-0195
1991
Bulatov, V.Bulatov, V., Brey, G.P., Foley, S.F.Origin of low Calcium, high chromium garnets by recrystallization of low pressure harzburgitesProceedings of Fifth International Kimberlite Conference held Araxa June, pp. 29-31GlobalExperimental petrology, Harzburgites -garnets
DS2003-0158
2003
Bulatov, V.Brey, G.P., Bulatov, V., Girnis, A., Harris, J., Stachel, T.Ferropericlase - a lower mantle phase in the upper mantle8 Ikc Www.venuewest.com/8ikc/program.htm, Session 6, AbstractGuineaMantle petrology
DS200412-0205
2003
Bulatov, V.Brey, G.P., Bulatov, V., Girnis, A., Harris, J., Stachel, T.Ferropericlase - a lower mantle phase in the upper mantle.8 IKC Program, Session 6, AbstractAfrica, GuineaMantle petrology
DS200412-0206
2004
Bulatov, V.Brey, G.P., Bulatov, V., Girnis, A., Harris, J.W., Stachel, T.Ferropericlase - a lower mantle phase in the upper mantle.Lithos, Vol. 77, 1-4, Sept. pp. 655-663.South America, BrazilUHP, diamond inclusions, olivine, San Luiz
DS200612-0172
2006
Bulatov, V.Brey, G., Bulatov, V., Girnis, A.Redox melting and composition of near liquidus melts of C O H bearing peridotite.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.MantleRedox melting
DS1989-1319
1989
Bulatov, V.K.Ryabchikov, I.D., Brey, G., Kogarko, L.N., Bulatov, V.K.Partial melting of carbonated peridotite at 50 KBAR.(Russian)Geochemistry International (Geokhimiya), (Russian), No. 1, pp. 3-9RussiaCarbonatite, Peridotite
DS1989-1320
1989
Bulatov, V.K.Ryabchikov, I.D., Brey, G., Kogarko, L.N., Bulatov, V.K.Partial melting of carbonatized peridotite at 50 kbarGeochemistry International, Vol. 26, No. 8, pp. 1-6RussiaLherzolite, Experimental petrology
DS1995-0231
1995
Bulatov, V.K.Bulatov, V.K., Girnis, A.V., Brey, G.P.Anhydrous partial melting of spinel lherzolites from 3.5 to 20 KBAR:composition of partial melts.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 80-82.RussiaLherzolites
DS1999-0100
1999
Bulatov, V.K.Bulatov, V.K., Girnis, A.V., Brey, G.P.Experimental melting of spinel lherzolites and the problem of the primary magma genesis of oceanic basaltsPetrology, Vol. 7, No. 1, Jan-Feb. pp. 21-31.MantleMagma, Lherzolite - experimental petrology
DS2002-0222
2002
Bulatov, V.K.Bulatov, V.K., Girnis, A.V., Brey, G.P.Experimental melting of a modally heterogeneous mantleMineralogy and Petrology, Vol.75,3-4, pp.131-52.MantleMelt
DS200512-0341
2005
Bulatov, V.K.Girnis, A.V., Bulatov, V.K., Brey, G.P.Transition from kimberlite to carbonatite melt under mantle parameters: an experimental study.Petrology, Vol. 13, 1, pp. 1-15.Melting - kimberlite/carbonatite
DS200612-0464
2006
Bulatov, V.K.Girnis, A.V., Bulatov, V.K., Lahaye, Y., Brey, G.P.Partitioning of trace elements between carbonate silicate melts and mantle minerals: experiment and petrological consequences.Petrology, Vol. 14, 5, pp. 492-514.MantleMelts
DS200812-0139
2007
Bulatov, V.K.Brey, G.P., Bulatov, V.K., Girnis, A.V.Geobarometry for peridotites: experiments in simple and natural systems from 6 to 10 GPa.Journal of Petrology, Vol. 49, 1, pp. 3-24.TechnologyGarnet
DS200812-0140
2008
Bulatov, V.K.Brey, G.P., Bulatov, V.K., Girnis, A.V.Experimental melting of magnesite bearing peridotite with H2O and F at 6 - 10 GPa, and implications for the genesis of kimberlites.9IKC.com, 3p. extended abstractMantleMelting
DS200812-0141
2008
Bulatov, V.K.Brey, G.P., Bulatov, V.K., Girnis, A.V., Lahaye, Y.Experimental melting of carbonated peridotite at 6-10 GPa.Journal of Petrology, Vol. 49, 4, pp. 797-821.MantleMelting
DS200912-0084
2009
Bulatov, V.K.Bulatov, V.K., Girnis, A.V., Brey, G.P.Experimental melting of carbonated K rich garnet harzburgite and origin of kimberlite melts.alkaline09.narod.ru ENGLISH, May 10, 2p. abstractTechnologyMelting
DS200912-0252
2009
Bulatov, V.K.Girnis, A.V., Bulatov, V.K., Brey, G.P.Influence of melt compositions on Fe, Mn and Ni partitioning between carbonate silicate melts and mantle minerals: experiments and applications.....alkaline09.narod.ru ENGLISH, May 10, 2p. abstractTechnologyGenesis of kimberlites and inclusions in diamonds
DS201112-0110
2011
Bulatov, V.K.Brey, G.P., Bulatov, V.K., Girnis, A.V.Melting of K rich carbonated peridotite at 6 - 10 GPa and the stability of K phases in the upper mantle.Chemical Geology, Vol. 281, 3-4, pp. 333-342.MantleCratonic geothermometry
DS201112-0371
2011
Bulatov, V.K.Girnis, A.V., Bulatov, V.K., Brey, G.P.Formation of primary kimberlite melts - constraints from experiments at 6-12 GPa and variable CO2/H2O.Lithos, In press available, 42p.TechnologyMelting
DS201112-0372
2011
Bulatov, V.K.Girnis, A.V., Bulatov, V.K., Brey, G.P.Formation of primary kimberlite melts - constraints from experiments at 6-12 GPa and variable CO2/H2O.Lithos, Vol. 127, 3-4, Dec. pp. 401-413.TechnologyMelting
DS201312-0312
2013
Bulatov, V.K.Girnis, A.V., Bulatov, V.K., Brey, G.P., Gerdes, A., Hofer, H.E.Trace element partitioning between mantle minerals and silico-carbonate melts at 6-12 Gpa and applications to mantle metasomatism and kimberlite genesis.Lithos, Vol. 160-161, pp. 183-200.MantleKimberlite genesis, melting
DS201509-0386
2015
Bulatov, V.K.Brey, G.P., Girnis, A.V., Bulatov, V.K., Hofer, H.E., Gerdes, A., Woodland, A.B.Reduced sediment melting at 7.5-12 Gpa: phase relations, geochemical signals and diamond nucleation.Contributions to Mineralogy and Petrology, Vol. 170, 25p.TechnologyExperimental petrology

Abstract: Melting of carbonated sediment in the presence of graphite or diamond was experimentally investigated at 7.5–12 GPa and 800–1600 °C in a multianvil apparatus. Two starting materials similar to GLOSS of Plank and Langmuir (Chem Geol 145:325–394, 1998) were prepared from oxides, carbonates, hydroxides and graphite. One mixture (Na-gloss) was identical in major element composition to GLOSS, and the other was poorer in Na and richer in K (K-gloss). Both starting mixtures contained ~6 wt% CO2 and 7 wt% H2O and were doped at a ~100 ppm level with a number of trace elements, including REE, LILE and HFSE. The near-solidus mineral assemblage contained a silica polymorph (coesite or stishovite), garnet, kyanite, clinopyroxene, carbonates (aragonite and magnesite-siderite solid solution), zircon, rutile, bearthite and hydrous phases (phengite and lawsonite at <9 GPa and the hydrous aluminosilicates topaz-OH and phase egg at >10 GPa). Hydrous phases disappear at ~900 °C, and carbonates persist up to 1000-1100 °C. At temperatures >1200 °C, the mineral assemblage consists of coesite or stishovite, kyanite and garnet. Clinopyroxene stability depends strongly on the Na content in the starting mixture; it remains in the Na-gloss composition up to 1600 °C at 12 GPa, but was not observed in K-gloss experiments above 1200 °C. The composition of melt or fluid changes gradually with increasing temperature from hydrous carbonate-rich (<10 wt% SiO2) at 800-1000 °C to volatile-rich silicate liquids (up to 40 wt% SiO2) at high temperatures. Trace elements were analyzed in melts and crystalline phases by LA ICP MS. The garnet-melt and clinopyroxene-melt partition coefficients are in general consistent with results from the literature for volatile-free systems and silicocarbonate melts derived by melting carbonated peridotites. Most trace elements are strongly incompatible in kyanite and silica polymorphs (D < 0.01), except for V, Cr and Ni, which are slightly compatible in kyanite (D > 1). Aragonite and Fe-Mg carbonate have very different REE partition coefficients (D Mst-Sd/L ~ 0.01 and D Arg/L ~ 1). Nb, Ta, Zr and Hf are strongly incompatible in both carbonates. The bearthite/melt partition coefficients are very high for LREE (>10) and decrease to ~1 for HREE. All HFSE are strongly incompatible in bearthite. In contrast, Ta, Nb, Zr and Hf are moderately to strongly compatible in ZrSiO4 and TiO2 phases. Based on the obtained partition coefficients, the composition of a mobile phase derived by sediment melting in deep subduction zones was calculated. This phase is strongly enriched in incompatible elements and displays a pronounced negative Ta-Nb anomaly but no Zr-Hf anomaly. Although all experiments were conducted in the diamond stability field, only graphite was observed in low-temperature experiments. Spontaneous diamond nucleation and the complete transformation of graphite to diamond were observed at temperatures above 1200-1300 °C. We speculate that the observed character of graphite-diamond transformation is controlled by relationships between the kinetics of metastable graphite dissolution and diamond nucleation in a hydrous silicocarbonate melt that is oversaturated in C.
DS201805-0945
2018
Bulatov, V.K.Girnis, A.V., Brey, G.P., Bulatov, V.K., Hofer, H.E., Woodland, A.B.Graphite to diamond transformation during sediment-peridotite interaction at 7.5 and 10.5 Gpa.Lithos, in press available 42p.Mantleperidotites

Abstract: Diamond nucleation and growth were investigated experimentally at 7.5 and 10.5?GPa and temperatures up to 1500?°C. Samples consisted of two layers: i) H2O- and CO2-bearing model sediment and ii) graphite-bearing garnet harzburgite comprising natural minerals. Two experimental series were conducted, one under a controlled temperature gradient with the sedimentary layer usually in the cold zone and the other under isothermal conditions. In the latter case, diamond seeds were added to the sedimentary mixture. During the experiments, the sedimentary layer partially or completely melted, with the melt percolating and interacting with the adjacent harzburgite. The graphite-to-diamond transition in the peridotite was observed above 1300?°C at 7.5?GPa and 1200?°C at 10.5?GPa in the temperature-gradient experiments, and at temperatures ~100?°C lower in the isothermal experiments with diamond seeds. Newly formed diamond occurs mostly as individual grains up to 10??m in size and is separate from graphite aggregates. In some cases, an association of diamond with magnesite was observed. Diamond nucleation occurs in hydrous and CO2-bearing silicate melt following graphite dissolution and recrystallization. In the case of the diamond-magnesite association, diamond was probably formed through carbonate reduction coupled with graphite oxidation. The composition of the melts ranged from “carbonatitic” with ~10?wt% SiO2 and?>?50?wt% volatiles to hydrous silicate with ~40?wt% SiO2 and?
DS201212-0806
2012
Bulbak, T.A.Yelisseyev, A.P., Afanasiev, V.P., Kopylova, M.G., Bulbak, T.A.The effect of metamorphic annealing and Betairradiation in optical properties of type 1AA diamonds.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractCanada, Ontario, RussiaDiamond - metamorphism
DS201601-0047
2015
Bulbak, T.A.Tomilenko, A.A., Kuzmin, D.V., Bulbak, T.A., Timina, T.Yu., Sobolev, N.V.Composition of primary fluid and melt inclusions in regenerated olivines from hypabyssal kimberlites of the Malokuonapskaya pipe ( Yakutia).Doklady Earth Sciences, Vol. 465, 1, pp. 1168-1171.RussiaDeposit - Malokuonapskaya
DS201608-1445
2016
Bulbak, T.A.Tomilenko, A.A., Bulbak, T.A., Khomenko, M.O., Kuzmin, D.V., Sobolev, N.V.The composition of volatile components in olivines from Yakutian kimberlites of various ages: evidence from gas chromatography - mass spectrometry.Doklady Earth Sciences, Vol. 469, 1, pp. 690-694.RussiaDeposit - Olivinvaya, Malokuonapskaya, Udachnaya-East

Abstract: The composition of volatiles from fluid and melt inclusions in olivine phenocrysts from Yakutian kimberlite pipes of various ages (Olivinovaya, Malokuonapskaya, and Udachnaya-East) were studied for the first time by gas chromatography-mass spectrometry. It was shown that hydrocarbons and their derivatives, as well as nitrogen-, halogen-, and sulfur-bearing compounds, played a significant role in the mineral formation. The proportion of hydrocarbons and their derivatives in the composition of mantle fluids could reach 99%, including up to 4.9% of chlorineand fluorine-bearing compounds.
DS201710-2269
2017
Bulbak, T.A.Tomilenko, A.A., Kuzmin, D.V., Bulbak, T.A., Sobolev, N.V.Primary melt and fluid inclusions in regenerated crystals and phenocrysts of olivine from kimberlites of the Udachnaya-East pipe, Yakutia: the problem of the kimberlite melt.Doklady Earth Sciences, Vol. 475, 2, pp. 949-952.Russiadeposit - Udachnaya-East

Abstract: The primary melt and fluid inclusions in regenerated zonal crystals of olivine and homogeneous phenocrysts of olivine from kimberlites of the Udachnaya-East pipe, were first studied by means of microthermometry, optic and scanning electron microscopy, electron and ion microprobe analysis (SIMS), inductively coupled plasma mass-spectrometry (ICP MSC), and Raman spectroscopy. It was established that olivine crystals were regenerated from silicate-carbonate melts at a temperature of ~1100°C.
DS201811-2613
2018
Bulbak, T.A.Tomilenko, A.A., Zhimulev, E.I., Bulbak, T.A., Sonin, V.M., Chepurov, A.I., Pokhilenko, N.P.Peculiarities of the composition of volatiles of diamonds synthesized in the Fe-S-C system: data on gas chromatography - mass spectrometry.Doklady Earth Sciences, Vol. 482, 1, pp. 1207-1211.Russiaspectrometry

Abstract: The first chromatography-mass spectroscopy data on volatiles in diamonds synthesized in the Fe-S-C system with 5 wt % S at 1400-1450°C and 5.0-5.5 GPa indicate the evolution of volatile composition during the diamond growth and, correspondingly, the variation in redox conditions of the reaction cell. A significant role is played by various hydrocarbons (HCs) and their derivatives, the content of which can reach 87%. Our data on possible abiogenic synthesis of HCs (components of natural gas and oil) can result in global recalculations (including climate) related to the global C cycle.
DS201911-2565
2019
Bulbak, T.A.Soboelev, N.V., Logvinova, A.M., Tomilenko, A.A., Wirth, R., Bulbak, T.A., Lukyanova, L.I., Fedorova, E.N., Reutsky, V.N., Efimova, E.S.Mineral and fluid inclusions in diamonds from the Urals placers, Russia: evidence for solid molecular N2 and hydrocarbons in fluid inclusions.Geochimica et Cosmochimica Acta, Vol. 266, pp. 197-212.Russia, Uralsdiamond inclusions

Abstract: The compositions of mineral inclusions from a representative collection (more than 140 samples) of diamonds from the placer deposits in the Ural Mountains were studied to examine their compositional diversity. The overwhelming majority of rounded octahedral and dodecahedral stones typical of placers contain eclogitic (E-type) mineral inclusions (up to 80%) represented by garnets with Mg# 40-75 and Ca# 10-56, including the unique high calcic “grospydite” composition, omphacitic pyroxenes containing up to 65% of jadeite, as well as kyanite, coesite, sulfides, and rutile. Peridotitic (P-type) inclusions are represented by olivine, subcalcic Cr-pyrope, chrome diopside, enstatite and magnesiochromite that are typical for diamonds worldwide. Comparing the chemical composition of olivine, pyrope and magnesiochromite in diamonds of the Urals, north-east of the Siberian platform placers and Arkhangelsk province kimberlites show striking similarity. There are significant differences only in the variations of carbon isotopic composition of the diamonds from the placers of the Urals and north-east of the Siberian platform. One typical rounded dodecahedral diamond was found to contain abundant primary oriented submicrometer-sized (<3.0?µm) octahedral fluid inclusions identified by transmission electron microscopy, which caused the milky color of the entire diamond crystal. The electron energy-loss spectrum of a singular inclusion has a peak at ?405?eV, indicating that nitrogen is present. The Raman spectra with peaks at 2346-2350?cm?1 confirmed that nitrogen exists in the solid state at room temperature. This means that fossilized pressure inside fluid inclusions may be over 6.0 GPa at room temperature, so the diamond may be considered sublithospheric in origin. However, identification of unique fluid inclusions in one typical placer diamond allows one to expand the pressure limit to at least more than 8.0 GPa. The volatile components of four diamonds from the Urals placers were analyzed by gas chromatography-mass spectrometry (GC-MS). They are represented (rel. %) by hydrocarbons and their derivatives (14.8-78.4), nitrogen and nitrogenated compounds (6.2-81.7), water (2.5-5.5), carbon dioxide (2.8-12.1), and sulfonated compounds (0.01-0.96). It is shown that high-molecular-weight hydrocarbons and their derivatives, including chlorinated, nitrogenated and sulfonated compounds, appear to be stable under upper mantle P-T conditions. A conclusion is drawn that Urals placer diamonds are of kimberlitic origin and are comparable in their high E-type/P-type inclusion ratios to those from the northeastern Siberian platform and in part to diamonds of the Arkhangelsk kimberlite province.
DS202008-1379
2020
Bulbak, T.A.Chepurov, A.I., Tomilenko, A.A., Sonin, V.M., Zhimulev, E.I., Bulbak, T.A., Cheperov, A.A., Sobolev, N.V.Interaction of an Fe-Ni melt with anthracene ( C14H10) in the presence of olivine at 3 Gpa: fluid phase composition.Doklady Earth Sciences, Vol. 492, pp. 333-337.MantleUHP, diamond

Abstract: The first results on the interaction between an Fe-Ni melt and anthracene (?14?10) in the presence of olivine at 3 GPa and 1500°? and on the study of the component composition of the fluid generated in this process are presented. The stability of aliphatic hydrocarbons in the implemented conditions is confirmed experimentally. It is established that, under these conditions, crystallization of high-magnesian olivines occurs (Fo = 97-98 mol %). The composition of the fluid is similar to the composition of the fluid from inclusions in synthetic diamonds. The conditions implemented in the experiment might have occurred at the early stages of the Earth’s evolution.
DS202008-1449
2020
Bulbak, T.A.Sokol, I.A., Sokol, A.G., Zaikin, P.A., Tomilenko, A.A., Bulbak, T.A.Hydrogenation of graphite, diamond, carbonates and iron carbides as the source of hydrocarbons in the upper mantle.Goldschmidt 2020, 1p. AbstractMantlehydrogen

Abstract: Formation of hydrocarbons by reactions of hydrogenbearing fluids with carbon [1] (13C soot, graphite, or diamond), carbonate-bearing pelites [2] and iron carbides (Fe3C and Fe7C3) [3] was simulated at 5.5-7.8 GPa and 1100- 1400°C, fH2 in Pt and Au capsules being controlled at the Mo+MoO2+H2O or Fe+FeO+H2O equilibria. For the first time, formation of hydrocarbons from inorganic compounds was proved by the reaction of 13C with hydrogen, which yielded isotopically pure alkanes. The greatest amounts of HCs (CH4/C2H6 < 1, CH4/C3H8 and CH4/C4H10 ? 10) formed at 1400°C in the 10-hr run. The amount of HCs synthesized at 1200°C was twice smaller. The rate of HCs formation was slowest in runs with diamond. At 1200 °C, light alkanes (C1?C2>C3>C4) formed either by direct hydrogenation of Fe3C or Fe7C3, or by hydrogenation of graphite/diamond in the presence of Fe3C, Fe7C3. The CH4/C2H6 ratio in the fluids decreased from 5 to 0.5 with decreasing iron activity and the C fraction increased in the series: Fe-Fe3C?Fe3C- Fe7C3?Fe7C3-graphite?graphite-Fe3C-magnesite and Fe3C-H2O-CO2 systems at 1200 °C yielded magnesiowüstite and wüstite, respectively, and both produced C-rich Fe7C3 and mainly light alkanes (C1?C2>C3>C4). In the experiments containing pelites methaneimine (CH3N) was found to be the main N-bearing compound. The experiments have provided the first unambiguous evidence that volatile-rich and reduced mantles of terrestrial planets (at fO2 near or below IW) provided favorable conditions for abiotic generation of complex hydrocarbon systems that predominantly contain light alkanes. The conditions favorable for HC formation exist in earth mantle, where slab-derived H2O-, CO2- and carbonate-bearing fluids interact with metal-saturated mantle.
DS202010-1880
2020
Bulbak, T.A.Sonin, V.M., Tomilenko, A.A., Zhimulev, E.I., Bulbak, T.A., Timina, T.Y., Chepurov, A.I., Pokhilenko, N.P.Diamond crystallization at high pressure: the relative efficiency of metal graphite and metal carbonate systems.Doklady Earth Sciences, Vol. 493, 1, pp. 508-512.RussiaUHP

Abstract: Data on the interaction of the Fe-Ni melt with CaCO3 and graphite at 5 GPa and 1400°? under the thermogradient conditions used in experiments on the growth of diamond on the BARS high-pressure apparatus are presented. The phase composition and component composition of the fluid captured by diamonds in the form of inclusions were studied by gas chromatography-mass spectrometry (GC-MS). Diamonds were synthesized from graphite. During the interaction of the Fe-Ni melt with CaCO3, Ca-Fe oxides and (Fe, Ni)3C carbide were formed. The stability of heavy hydrocarbons under the experimental conditions was confirmed. It was established that the composition of the fluid in synthesized diamonds is close to the composition of the fluid from inclusions in some natural diamonds. Nevertheless, it was concluded that crystallization of large diamonds under natural conditions is hardly possible due to the filling of the main crystallization volume with refractory oxide phases.
DS201812-2786
2018
Bulbuc, K.M.Bulbuc, K.M., Galarneau, M., Stachel, T., Stern, R.A., Kong, J., Chinn, I.Contrasting growth conditions for sulphide-and garnet-included diamonds from the Victor mine ( Ontario).2018 Yellowknife Geoscience Forum , p. 97-98. abstractCanada, Ontario, Attawapiskatdeposit - Victor

Abstract: The Victor Diamond Mine, located in the Attawapiskat kimberlite field (Superior Craton), is known for its exceptional diamond quality. Here we study the chemical environment of formation of Victor diamonds. We imaged eight sulphide-included diamond plates from Victor using cathodoluminescence (CL). Then, along core-rim transects, we measured nitrogen content and aggregation state utilizing Fourier Transform Infrared (FTIR) spectroscopy, and the stable isotope compositions of carbon (?13C) and nitrogen (?15N), using a multi-collector ion microprobe (MC-SIMS). We compare the internal growth features and chemical characteristics of these sulphide inclusion-bearing diamonds with similar data on garnet inclusion-bearing diamonds from Victor (BSc thesis Galarneau). Using this information, possible fractionation processes during diamond precipitation are considered and inferences on the speciation of the diamond forming fluid(s) are explored. Sulphide inclusion-bearing diamonds show much greater overall complexity in their internal growth features than garnet inclusion-bearing diamonds. Two of the sulphide-included samples have cores that represent an older generation of diamond growth. Compared to garnet inclusion-bearing diamonds, the sulphide-included diamonds show very little intra-sample variation in both carbon and nitrogen isotopic composition; the inter-sample variations in carbon isotopic composition, however, are higher than in garnet included diamonds. For sulphide-included diamonds, ?13C ranges from -3.4 to -17.5 and ?15N ranges from -0.2 to -9.2. Garnet inclusion-bearing diamonds showed ?13C values ranging from -4.6 to -6.0 and ?15N ranging from -2.8 to -10.8. The observation of some 13C depleted samples indicates that, unlike the lherzolitic garnet inclusion-bearing diamonds, the sulphide inclusion-bearing diamonds are likely both peridotitic and eclogitic in origin. The total range in N content across sulphide inclusion-bearing diamonds was 2 to 981 at ppm, similar to the garnet-included samples with a range of 5 to 944 at ppm. The very limited variations in carbon and nitrogen isotopic signatures across growth layers indicate that sulphide-included Victor diamonds grew at comparatively high fluid:rock ratios. This is contrasted by the garnet inclusion-bearing diamonds that commonly show the effects of Rayleigh fractionation and hence grew under fluid-limited conditions.
DS1985-0419
1985
Bulenko, N.A.Martovitskiy, V.P., Zadnerprovskiy, B.I., Bulenko, N.A.The internal structure of synthetic diamonds with thread likeinclusions.(Russian)Kristallografiya, (Russian), Vol. 30, No. 6, pp. 1203-1206RussiaSynthetic Diamonds, Diamond Morphology
DS1982-0481
1982
Bulen'kov, N.A.Orlov, YU.L., Bulen'kov, N.A., Martovitskiy, V.P.Spheroid Diamond Crystals- a New Type of Fibrous Natural Single Crystals.Doklady Academy of Science USSR, Earth Science Section., Vol. 252, No. 1-6, PP. 117-120.RussiaCrystallography
DS1982-0482
1982
Bulienkov, N.A.Orlov, YU.L., Bulienkov, N.A., Martovitsky, V.P.A Study of the Internal Structure of Variety Iii Diamonds By X-ray Section Topography.Physics And Chemistry of Minerals, Vol. 8, No. 3, PP. 105-111.RussiaMineralogy, Crystallography
DS200612-1020
2006
Bulienkov, N.A.Orlov, Y.L., Bulienkov, N.A., Martovitsky, V.P.A study of the internal structure of variety III diamonds by X-ray section topography.Physics and Chemistry of Minerals, Vol. 8, 3, pp. 105-111.TechnologyDiamond morphology
DS1991-0196
1991
Bulin, N.K.Bulin, N.K., Yegorkin, A.V.The application of seismic dat a to explore kimberlite magma regions of the northern Russian Platform*(in Russian)Sovetskaya Geologiya, (Russian), No. 10, pp. 82-91RussiaGeophysics -seismics, Timan-Pechora region
DS1994-0234
1994
Bulin, N.K.Bulin, N.K., Egorkin, A.V.Usage of multiwave DSS for small scale forecasting of mineralization and presence of diamonds.Russian Geology and Geophysics, Vol. 34, No. 9, pp. 83-95.RussiaGeophysics, Diamond morphology
DS2001-0145
2001
Bulin, N.K.Bulin, N.K., Bulina, L.V., Dragunov, V.I.Deep extension zones beneath the Siberian platformDoklady Academy of Sciences, Vol. 381, No. 8, Oct/Nov. pp. 901-5.Russia, SiberiaTectonics, lineaments
DS2002-0223
2002
Bulin, N.K.Bulin, N.K.Lateral velocity heterogeneity of deep zones in the Earth's crust of the West Siberian Territory.Doklady, Vol. 387A, Nov-Dec. No. 9, pp. 1018-23.Russia, SiberiaTectonics, Geophysics - seismics
DS2001-0145
2001
Bulina, L.V.Bulin, N.K., Bulina, L.V., Dragunov, V.I.Deep extension zones beneath the Siberian platformDoklady Academy of Sciences, Vol. 381, No. 8, Oct/Nov. pp. 901-5.Russia, SiberiaTectonics, lineaments
DS1985-0095
1985
Bulionkov, N.A.Bulionkov, N.A.A Model of the Dispersion Diamond Like Amorphous Structure (ddas) and The significance of the Possibility of Ddas Micro inclusion Formation In dislocationless SiliconDoklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 284, No. 6, pp. 1392-1396RussiaDiamond Morphology
DS1999-0101
1999
Bulkah, A.G.Bulkah, A.G., Nesterov, A.R., et al.Crystal morphology and intergrowths of calzirtite, zirkelite, zirconloitein phosphorites and carbonatitesNeues Jhb. Min., No. 1, pp. 11-20.Russia, Kola PeninsulaCarbonatite
DS200712-0896
2007
Bull, A.L.Ritsema, J., McNamara, A.K., Bull, A.L.Tomographic filtering of geodynamic models: implications for model interpretation and large scale mantle structure.Journal of Geophysical Research, Vol. 112, B 1, B01303.MantleGeophysics - seismics
DS200912-0085
2009
Bull, A.L.Bull, A.L., McNamara, A.K., Ritsema, J.Synthetic tomography of plume clusters and thermochemical piles.Earth and Planetary Interiors, Vol. 278, 3-4, pp. 152-162.MantlePlume
DS201412-0083
2014
Bull, A.L.Bull, A.L., Domeer, M., Torsvik, T.H.The effect of plate motion history on the longevity of deep mantle heterogeneities.Earth and Planetary Science Letters, Vol. 401, pp. 172-182.MantleTectonics, Pangea
DS201607-1293
2016
Bull, A.L.Domeier, M., Doubrovine, P.V., Torsvik, T.H., Spakman, W., Bull, A.L.Global correlation of mantle structure and past subduction.Geophysical Research Letters, Vol. 43, 10, pp. 4945-4953.MantleSubduction

Abstract: Advances in global seismic tomography have increasingly motivated identification of subducted lithosphere in Earth’s deep mantle, creating novel opportunities to link plate tectonics and mantle evolution. Chief among those is the quest for a robust subduction reference frame, wherein the mantle assemblage of subducted lithosphere is used to reconstruct past surface tectonics in an absolute framework anchored in the deep Earth. However, the associations heretofore drawn between lower mantle structure and past subduction have been qualitative and conflicting, so the very assumption of a correlation has yet to be quantitatively corroborated. Here we show that a significant, time-depth progressive correlation can be drawn between reconstructed subduction zones of the last 130 Myr and positive S wave velocity anomalies at 600 -2300 km depth, but that further correlation between greater times and depths is not presently demonstrable. This correlation suggests that lower mantle slab sinking rates average between 1.1 and 1.9 cmyr 1.
DS200712-0122
2006
Bullem, W.Bullem, W., Zhang, J.The economics of diamond projects in the Canadian Arctic.Canadian Institute of Mining and Metallurgy, Dec.-Jan. pp.Canada, Northwest TerritoriesEconomics, discounted cash flow, DCF model
DS200612-0528
2006
BullenHanson, 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
DS200412-0788
2004
Bullen, D.S.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
DS200612-0527
2006
Bullen, D.S.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
DS200512-1242
2004
Bullen, W.Zhang, J., Bullen, W.The economics of diamond projects in the Canadian Arctic.32nd Yellowknife Geoscience Forum, Nov. 16-18, p.86. (talk)Canada, NunavutGovernment model
DS1996-1446
1996
Bulletin, G.W.Tuckwell, G.W., Bulletin, G.W., Sanderson, D.J.Models of fracture orientation at oblique spreading centersJournal of the Geological Society of London, Vol. 153, No. 2, Mar. pp. 185-190GlobalTectonics, Structure -fractures
DS1975-0721
1978
Bulletin, P.A.Culver, S.J., Williams, H.R., Bulletin, P.A.Infracambrian Glaciogenic Sediments from Sierra LeoneNature., Vol. 274, PP. 49-51.Sierra Leone, West AfricaGeology, Geomorphology
DS1995-0232
1995
Bulletin, S.J.Bulletin, S.J., Chalker, P.R.high pressureerformance diamond and diamond like coatingsJournal of Metals (JOM), Vol. 47, No. 4, April pp. 16-19.GlobalDiamond synthesis
DS1991-0197
1991
Bulletin, W.B.Bulletin, W.B.Geomorphic responses to climatic changeOxford University of Press, 352p. approx. $ 60.00 United StatesGlobalGeomorphology, Climate, Book -ad
DS1983-0158
1983
Bulletinen, G.J.Bulletinen, G.J.Continuing Investigations Into Behaviour of Impregnated Mining Bits in Hard Rock Drilling.Geodrilling, APRIL, PP. 7-14.GlobalDiamonds
DS1993-1536
1993
Bulletinen, T.Stimac, J.A., Goff, F., Bulletinen, T.Crustal xenoliths from Clear Lake, California: granulites directly related to magmatic underplating?The Xenolith window into the lower crust, abstract volume and workshop, p. 19.CaliforniaMagma, Xenoliths
DS1997-0112
1997
Bulletinen, T.D.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
DS1992-0187
1992
Bulletinock, S.J.Bulletinock, S.J.The application of high resolution aeromagnetics to kimberliteexplorationInternational Roundtable Conference on Diamond Exploration and Mining, held, pp. 115-121GlobalGeophysics -magnetics, Aeromagnetics
DS1994-1709
1994
Bulletinock, S.J.Street, G.J., Bulletinock, S.J., Kones, R.K.Airborne geophysics in diamond and gemstone explorationPreprint from Snowden Mining Forum held May 18, Perth, 8p. 6 figuresLesotho, Russia, Siberia, Northwest Territories, BotswanaGeophysics -aeromagnetics, Case histories -Australia
DS201705-0811
2017
Bullock, E.Bullock, E.Diamonds in the Sky.lithographie.org, No. 19, pp. 128-131.TechnologyBook - meteorites
DS201701-0031
2016
Bullock, E.S.Smith, E.M., Shirey, S.B., Nestola, F., Bullock, E.S., Wang, J., Richardson, S.H., Wang, W.Large gem diamonds from metallic liquid in Earth's deep mantle.Science, Vol. 354, 6318, pp. 1403-1405.MantleDiamond genesis

Abstract: The redox state of Earth’s convecting mantle, masked by the lithospheric plates and basaltic magmatism of plate tectonics, is a key unknown in the evolutionary history of our planet. Here we report that large, exceptional gem diamonds like the Cullinan, Constellation, and Koh-i-Noor carry direct evidence of crystallization from a redox-sensitive metallic liquid phase in the deep mantle. These sublithospheric diamonds contain inclusions of solidified iron-nickel-carbon-sulfur melt, accompanied by a thin fluid layer of methane ± hydrogen, and sometimes majoritic garnet or former calcium silicate perovskite. The metal-dominated mineral assemblages and reduced volatiles in large gem diamonds indicate formation under metal-saturated conditions. We verify previous predictions that Earth has highly reducing deep mantle regions capable of precipitating a metallic iron phase that contains dissolved carbon and hydrogen.
DS201803-0481
2018
Bullock, E.S.Tao, R., Fei, Y., Bullock, E.S., Xu, C., Zhang, L.Experimental investigation of Fe3+ rich majoritic garnet and its effect on majorite geobarometer.Geochimica et Cosmochimica Acta, Vol. 225, pp. 1-16.Technologygeobarometry

Abstract: Majoritic garnet [(Ca, Mg, Fe2+)3(Fe3+, Al, Si)2(SiO4)3] is one of the predominant and important constituents of upper mantle peridotite and ultra-deep subducted slabs. Majoritic substitution in garnet depends on pressure, and it has been used to estimate the formation pressure of natural majoritic garnet. Ferric iron (Fe3+) substitution occurs in natural majoritic garnets from mantle diamonds and shocked meteorites. However, available majorite geobarometers were developed without considering the effect of Fe3+ substitution in the structure. In this study, we systematically synthesized Fe3+- bearing majoritic garnets from 6.5?GPa to 15?GPa to evaluate the effect of Fe3+ on the majorite geobarometer. The Fe3+ contents of synthetic majoritic garnets were analyzed using the "Flank method" with the electron probe microanalyzer (EPMA). The results were compared with those based on the charge balance calculations. From the known synthesis pressures and measured Fe3+ contents, we developed a new majorite geobarometer for Fe3+-bearing majoritic garnets. Our results show that the existing majorite geobarometer, which does not take into account the Fe3+ substitution, could underestimate the formation pressure of majoritic garnets, especially for samples with a high majoritic component.
DS201809-2091
2018
Bullock, E.S.Smith, E., Shirey, S.B., Richardson, S.H., Nestola, F., Bullock, E.S., Wang, J., Wang, W.Blue boron-bearing diamonds from Earth's lower mantle.Nature, Vol. 560, Aug. 2, pp. 84-97.Mantlediamond - Type Ilb blue

Abstract: Geological pathways for the recycling of Earth’s surface materials into the mantle are both driven and obscured by plate tectonics1,2,3. Gauging the extent of this recycling is difficult because subducted crustal components are often released at relatively shallow depths, below arc volcanoes4,5,6,7. The conspicuous existence of blue boron-bearing diamonds (type IIb)8,9 reveals that boron, an element abundant in the continental and oceanic crust, is present in certain diamond-forming fluids at mantle depths. However, both the provenance of the boron and the geological setting of diamond crystallization were unknown. Here we show that boron-bearing diamonds carry previously unrecognized mineral assemblages whose high-pressure precursors were stable in metamorphosed oceanic lithospheric slabs at depths reaching the lower mantle. We propose that some of the boron in seawater-serpentinized oceanic lithosphere is subducted into the deep mantle, where it is released with hydrous fluids that enable diamond growth10. Type IIb diamonds are thus among the deepest diamonds ever found and indicate a viable pathway for the deep-mantle recycling of crustal elements.
DS201809-2092
2018
Bullock, E.S.Smith, E.M., Shirey, S.B., Richardson, S.H., Nestola, F., Bullock, E.S., Wang, J., Wang, W.Boron bearing, type llb diamonds from superdeep subduction.Goldschmidt Conference, 1p. AbstractMantlesubduction

Abstract: Type IIb diamonds, such as the Hope diamond, contain trace amounts of boron and are prized for their blue colors. Since boron is a quintessential crustal element, it is completely unexpected in diamond-forming fluids at mantle depths. Despite the mineralogical/geochemical interest in type IIb diamonds, almost nothing is known about how they form chiefly because of their rarity (?0.02% of all diamonds) and high gem value. To investigate the type of mantle host rock, the depth of origin (lithospheric vs. convecting mantle), and the source of boron, the high-volume diamond grading stream of the Gemological Institute of America was systematically screened to find type IIb diamonds with inclusions. Over a period of about two years, 46 prospective samples were identified and examined optical microscopy, X-ray diffraction, and infrared/Raman spectroscopy; a few diamonds were also analyzed for carbon isotopic composition and polished for electron probe microanalysis of inclusions. The examined inclusions represent retrogressed highpressure minerals, from metabasic to metaperidotitic hosts in the lowermost mantle transition zone (MTZ) to lower mantle (LM). These include former CaSiO3-perovskite, majorite, bridgmanite, stishovite, calcium-ferrite-type phase, and ferropericlase. The variably light carbon isotope compositions and inclusion mineralogy indicate diamond growth in deeply subducted oceanic lithosphere (crust and mantle). Some inclusions are found to have coexisting fluid (CH4 ± H2) that suggests the original high-pressure minerals interacted with hydrous media. We propose that the boron resided in serpentinized oceanic lithosphere. During subduction, the serpentine was metamorphosed to dense hydrous magnesium silicates (DHMS) that retained some boron. Upon breakdown in the MTZ/LM, these DHMS yielded boron-bearing hydrous fluids conducive to diamond growth.
DS201907-1575
2019
Bullocks, E.S.Smith, E.M., Shirey, S.B., Richardson, S.H., Nestola, F., Bullocks, E.S., Wang, J., Wang, W.Reply to: Evidence for two blue (type Ilb) diamond populations. ( Moore and Helmstaedt Nature Vol. 570, E26-27.Nature, Vol. 570, E28-29.Mantleboron
DS1996-0192
1996
Bulnaev, K.B.Bulnaev, K.B.Strontianite carbonatites of the Khalyuta deposit. Western Transbaikalregion, Russia.Geology of Ore Deposits, Vol. 38, No. 5, pp. 390-400.RussiaCarbonatite, Deposit - Khalyuta
DS1997-0142
1997
Bulnaev, K.B.Bulnaev, K.B.Carbonatite affinity of endogeneous carbonate rocks of the TransbaikalRegion.Doklady Academy of Sciences, Vol. 355, No. 5, Jun-July pp. 658-661.RussiaCarbonatite
DS2000-0122
2000
Bulnaev, K.B.Bulnaev, K.B.Rare earth element mineralization in the linear carbonatites of the Arshandeposit, Western TransbaikalGeol. Ore Dep., Vol. 42, No. 3, pp. 247-52.Russia, TransbaikalCarbonatite
DS2001-0146
2001
Bulnaev, K.B.Bulnaev, K.B.Origin of mantle shaped carbonatite bodies in the Khalyuta deposit, western Transbaikal region, Russia.Lithology and Mineral Resources, Vol. 36, No. 1, pp. 63-76.RussiaCarbonatite, Deposit - Khalyuta
DS200412-0240
2004
Bulnaev, K.B.Bulnaev, K.B.Behavior Sr, Ba, and REE in carbonatites of western Transbaikalia.Geochemistry International, Vol. 42, 3, pp. 285-292.Russia, BaikalGeochemistry
DS1996-0193
1996
Bulow, A.Bulow, A.Mining in a changing worldJournal of Mineral Policy, Raw Materials, Vol. 12, No. 2, pp. 31-34SwedenMining, legal, discoveries, Economics
DS1993-0188
1993
Bultman, M.W.Bultman, M.W., Force, E.R., Gettings, M.E., Fisher, F.S.Comments on the three step method for quantification of undiscovered mineral resourcesUnited States Geological Survey (USGS) Open File, No. 93-0023, 59p. approx. $ 9.75GlobalEconomics, Resources
DS1985-0417
1985
Bulyenkov, N.A.Martovitskiy, V.P., Bulyenkov, N.A., et al.Characteristics of the Internal Structure of Ballas Diamonds. (russian)Izvest. Akad. Nauk SSSR, ser. geol., (Russian), No. 6, pp. 71-77RussiaCrystallography, Diamond
DS1985-0477
1985
Bulygina, T.I.Naletov, A.M., Nepsha, V.I., Klyuev, YU.A., Bulygina, T.I.Structure and Properties of Lonsdaleite Containing Diamonds. (russian)Vopr. Povysh. Kchestva. Almaz. Odrab., (Russian) (POL), pp. 75-83RussiaDiamond Morphology
DS1975-0045
1975
Bulykin, L.D.Bulykin, L.D., Nikitin, I.I.A Type of Ultramafic Rock Previously Unknown in the UralsDoklady Academy of Science USSR, Earth Science Section., Vol. 220, No. 1-6, PP. 140-142.RussiaKimberlite, Olivine, Spinel
DS2002-0224
2002
Bumby, A.J.Bumby, A.J., Eriksson, P.G., Van der Merve, R., Brummer, J.J.Shear zone controlled basins in the Blouberg area, Northern Province, syn and post tectonic sedimentation relating to 2.0 Ga reactivation of Limopo Belt.Journal of African Earth Sciences, Vol. 33, No. 3-4,pp. 445-61.South AfricaStructure, tectonics - not specific to diamonds
DS200712-0296
2006
Bumby, A.J.Eriksson, P.G., Mazumder, R., Catuneanu, O., Bumby, A.J., Ilondo, B.O.Precambrian continental free board and geological evolution: a time perspective. Kaapvaal, Pilbara, SinghbhumEarth Science Reviews, in press availableMantle, South Africa, Australia, IndiaContinent freeboard, crustal growth, thickness, plumes
DS202009-1626
2011
Bumby, A.J.Eriksson, P.G., Lenhardt, N., Wright, D.T., Mazumder, R., Bumby, A.J.Late Neoarchean-paleoproterozoic supracrustal basin-fills of the Kaapvaal craton: relevance of the supercontinent cycle, the "Great Oxidation Event" and "Snowball Earth?". Note Date*** glaciationMarine and Petroleum Geology, Vol. 28, pp. 1385-1401.Africa, South Africageomorphology

Abstract: The application of the onset of supercontinentality, the “Great Oxidation Event” (GOE) and the first global scale glaciation in the Neoarchaean-Palaeoproterozoic as panacea-like events providing a framework or even chronological piercing points in Earth’s history at this time, is questioned. There is no solid evidence that the Kaapvaal craton was part of a larger amalgamation at this time, and its glacigenic record is dominated by deposits supporting the operation of an active hydrological cycle in parallel with glaciation, thereby arguing against the “Snowball Earth Hypothesis”. While the Palaeoproterozoic geological record of Kaapvaal does broadly support the GOE, this postulate itself is being questioned on the basis of isotopic data used as oxygen-proxies, and sedimentological data from extant river systems on the craton argue for a prolongation of the greenhouse palaeo-atmosphere (possibly in parallel with a relative elevation of oxygen levels) which presumably preceded the GOE. The possibility that these widespread events may have been diachronous at the global scale is debated.
DS2003-0184
2003
Bump, A.P.Bump, A.P.Reactivation, trishear modeling and folded basement in Laramide uplifts: implications forGsa Today, March pp. 4-10.Arizona, UtahTectonics
DS200412-0241
2003
Bump, A.P.Bump, A.P.Reactivation, trishear modeling and folded basement in Laramide uplifts: implications for the origins of intra-continental faultGSA Today, March pp. 4-10.United States, Arizona, UtahTectonics
DS1995-0233
1995
Bump, H.Bump, H., Dueker, K., et al.Colorado Plateau crust and upper mantle structure from the deep probe natural source experiment.Eos, Vol. 76, No. 46, Nov. 7. p.F604. Abstract.Colorado PlateauMantle, Geophysics -seismics
DS1950-0201
1955
Bumstead, N.Bumstead, N.Diamonds on the Atlantic Sea BeachNational Geographic : Atlantic Odyssey: Iceland To Antarctic, Vol. 108, No. 6, DECEMBER PP. 772-773; 777-780.Southwest Africa, NamibiaLittoral Diamond Placers, Cdm, Saddle Hill
DS201112-0561
2011
BunchKurbatov, A.V., Mayewski, P.A., Steffensen, J.P., West, A., Kennett, Bunch, Handley, Introne, Shane, Mercer etcDiscovery of a nanodiamond rich layer in the Greenland ice sheet.Journal of Glaciology, Vol. 56, no. 199, pp. 747-757.Europe, GreenlandGeomorphology
DS1990-0255
1990
Bunch, J.P.Bunch, J.P., Gurr, T.M.Environmental auditing as an effective management tool for the miningindustryAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint, No. 90-13, 11pGlobalMining, Environmental audit
DS200912-0086
2008
Bunch, T.E.Bunch, T.E., Wittke, J.H., West, A., Kennett, J.P., Ouq Hee, S.S., Wolbach, W.S., Stich, A., Mercer, C., WeaverHexagonal diamonds ( lonsdaleite) discovered in the K/T impact layer in Spain and New Zealand.American Geological Union, Fall meeting Dec. 15-19, Eos Trans. Vol. 89, no. 53, meeting supplement, 1p. abstractEurope, Spain, New ZealandNanodiamonds
DS201412-0460
2014
Bunch, T.E.Kinzie, C.R., Que Hee, S.S., Stich, A., Tague, K.A., Mercer, C., Razink, J.J., Kennett, D.J., DeCarli, P.S., Bunch, T.E., Wittke, J.H., Israde-Alcantara, I., Bischoff, J.L., Goodyear, A.C., Tankersley, K.B., Kimbel, D.R., Culleton, B.J., Erlandson, J.M.Nanodiamond rich layer across three continents consistent with major cosmic impact at 12,800 Cal BP Journal of Geology, Vol 122, 5, pp. 475-506.Global, GreenlandNanodiamonds
DS201502-0069
2014
Bunch, T.E.Kinzie, C.R., Que Hee, S.S., Stich, A., Tague, K.A., Mercer, C., Razink, J.J., Kennett, D.J., DeCarli, P.S., Bunch, T.E., Wittke, J.H., Israde-Alantara, I., Bischoff, J.L., Goodyear, A.C., Tankersley, K.B., Kimbel, D.R., Culleton, B.J., Erlandson, J.M.Nanodiamond-rich layer across three continents consistent with major cosmic impact at 12,800 Cal BP.Journal of Geology, Vol. 122, Sept. pp. 475-506.South America, BrazilNanodiamonds
DS1985-0163
1985
Bundtzen, T.K.Eakins, G.R., Bundtzen, T.K., et al.Crooked Creek Diamond DiscoveryAlaska's Mineral Industry 1984, Special Report, No. 38, pp.10-11AlaskaDiamond Occurrences
DS1993-1142
1993
Bundtzen, T.K.Nokleberg, W.J., Bundtzen, T.K., Grybeck, D., Koch, R.D., EreminMetallogenesis of maIn land Alaska and the Russian northeastUnited States Geological Survey (USGS) Open file, No. 93-339, approx. $ 48.00Alaska, RussiaBook -table of contents, Metallogeny, alluvials, placers, lode, chromite, gold, platinum group elements (PGE)
DS1995-0234
1995
Bundtzen, T.K.Bundtzen, T.K., Fonseca, A.L., Mann, R.Geology and mineral deposits of the Russian Far EastGlacier House Publications, 160p. $ 40.00RussiaBook -table of contents, Mneral deposits of Far East
DS1960-0131
1961
Bundy, F.P.Bundy, F.P., et al.Diamond graphite equilibrium line from growth and graphitization ofdiamond.Journal of Chem. Physics, Vol. 35, No. 2, Aug. pp. 383-391.GlobalDiamond Genesis, Growth
DS1980-0080
1980
Bundy, F.P.Bundy, F.P.The P T Phase and Reaction Diamgram for Elemental Carbon 197Journal of Geophysical Research, Vol. 85, No. B 12, DECEMBER 10TH. PP. 6930-6936.GlobalDiamond, Graphite, Mineralogy
DS1988-0093
1988
Bundy, P.Bundy, P.Synthesis of diamonds and studies in the high pressure regionSoviet Journal of Superhard Material, Vol. 10, No. 3, pp. 1-8RussiaDiamond synthesis
DS1997-0759
1997
Bunge, H.P.Megnin, C., Bunge, H.P., Richards, M.A.Imaging 3 D spherical convection models: what can seismic tomography tellus about mantle dynamics.Geophysical research Letters, Vol. 24, No. 11, June 1, pp. 1299-1302.MantleGeophysics - seismics, Tomography
DS1999-0594
1999
Bunge, H.P.Richards, M.A., Bunge, H.P., Baumgardner, J.R.Polar wandering in mantle convection modelsGeophysical Research Letters, Vol. 26, No. 12, June 15, pp. 1777-80.MantleConvection
DS2001-0147
2001
Bunge, H.P.Bunge, H.P., Davies, J.H.Tomographic images of a mantle circulation modelGeophysical Research Letters, Vol. 28, No. 1, Jan. pp. 77-80.MantleModel - circulation, Tomography
DS2001-0227
2001
Bunge, H.P.Davies, J.H., Bunge, H.P.Seismically "fast" geodynamic mantle modelsGeophysical Research Letters, Vol. 28, No. 1, Jan. pp. 73-76.MantleGeodynamics, Tectonics
DS2002-0225
2002
Bunge, H.P.Bunge, H.P., Richards, M.A., Baumgardner, J.R.Mantle circulation models with sequential dat a assimilation: inferring present day mantle structure from plate motion histories.Philosophical Transactions, Royal Society of London Series A Mathematical, Vol.1800, pp. 2545-68.MantleGeochemistry - model, tectonics
DS2003-0185
2003
Bunge, H.P.Bunge, H.P., Hagelberg, C.R., Travis, B.J.Mantle circulation models with variational dat a assimilation: inferring past mantle flowGeophysical Journal International, Vol. 152, No. 2, pp. 280-301.MantleGeophysics - seismics
DS200712-0841
2007
Bunge, H.P.Phillips, B.R., Bunge, H.P.Supercontinent cycles disrupted by strong mantle plumes.Geology, Vol. 35, 9. pp. 847-850.MantleAccretion
DS201802-0226
2017
Bunge, H.P.Chust, T.C., Steinle Neumann, G., Dolejs, D., Schuberth, B.S., Bunge, H.P.A computational framework for mineralogical thermodynamics. MMA-EoSJournal of Geophysical Research, Vol. 122, 10.1002/2017JB014501Mantlethermodynamics

Abstract: We present a newly developed software framework, MMA-EoS, that evaluates phase equilibria and thermodynamic properties of multicomponent systems by Gibbs energy minimization, with application to mantle petrology. The code is versatile in terms of the equation-of-state and mixing properties and allows for the computation of properties of single phases, solution phases, and multiphase aggregates. Currently, the open program distribution contains equation-of-state formulations widely used, that is, Caloric-Murnaghan, Caloric-Modified-Tait, and Birch-Murnaghan-Mie-Grüneisen-Debye models, with published databases included. Through its modular design and easily scripted database, MMA-EoS can readily be extended with new formulations of equations-of-state and changes or extensions to thermodynamic data sets. We demonstrate the application of the program by reproducing and comparing physical properties of mantle phases and assemblages with previously published work and experimental data, successively increasing complexity, up to computing phase equilibria of six-component compositions. Chemically complex systems allow us to trace the budget of minor chemical components in order to explore whether they lead to the formation of new phases or extend stability fields of existing ones. Self-consistently computed thermophysical properties for a homogeneous mantle and a mechanical mixture of slab lithologies show no discernible differences that require a heterogeneous mantle structure as has been suggested previously. Such examples illustrate how thermodynamics of mantle mineralogy can advance the study of Earth's interior.
DS201802-0229
2017
Bunge, H.P.Crust. T.C., Steinle-Neumann, G., Dolejs, D., Schuberth, B.S., Bunge, H.P.MMA-EoS: a computational framework for mineralogical thermodynamics.Journal of Geophysical Research, 122, https://doi.org/10.1002/2017JB014501Technologyprogram - MMA-EoS
DS2001-0148
2001
Bunge, H-P.Bunge, H-P., Ricard, Y., Matas, J.Non-adiabaticity in mantle convectionGeophysical Research Letters, Vol. 28, No. 5, Mar. 1, pp. 879-82.MantleGeophysics - seismics
DS200512-0852
2005
Bunge, H-P.Phillips, B.R., Bunge, H-P.Heterogeneity and time dependence in 3D spherical mantle convection models with continental drift.Earth and Planetary Science Letters, Vol. 233, 1-2, April 30, pp. 121-135.Mantle, Asia, AntarcticaWilson cycle, convection, supercontinents
DS200612-0196
2005
Bunge, H-P.Bunge, H-P.Low plume excess temperature and high core heat flux inferred from non-adiabatic geotherms in internally heated mantle circulation models.Physics of the Earth and Planetary Interiors, Vol. 153, 1-3, pp. 3-10.MantleGeothermometry
DS200612-0317
2006
Bunge, H-P.Davies, J.H., Bunge, H-P.Are splash plumes the origin of minor hotspots?Geology, Vol.34, 5, May pp. 349-352.MantleConvection, hot spot
DS200812-0896
2007
Bunge, H-P.Piazzoni, A.S., Steinle-Neumann, G., Bunge, H-P., Dolejs, D.A mineralogical model for density and elasticity of the Earth's mantle.Geochemistry, Geophysics, Geosystems: G3, Vol. 8, 11, Nov. 30, pp. 1-23.MantleMineralogy
DS200912-0587
2009
Bunge, H-P.Phillips, B.R., Bunge, H-P., Schaber, K.True polar wander in mantle convection models with multiple, mobile continents.Gondwana Research, Vol. 15, 3-4, pp. 288-196.MantleConvection
DS201012-0198
2010
Bunge, H-P.Fichtner, A., Kennett, B.L.N., Igel, H., Bunge, H-P.Full waveform tomography for radially anisotropic structure: new insights into present and past states of the Australasian upper mantle.Earth and Planetary Science Letters, Vol. 290, 3-4, pp. 270-280.Australia, AsiaTomography
DS201212-0645
2012
Bunge, H-P.Shephard, G.E., Bunge, H-P., Schuberth, B.S.A., Muller, R.D., Talsma, A.S., Moder, C., Landgrebe, T.C.W.Testing absolute plate reference frames and the implications for the generation of geodynamic mantle heterogeneity stucture.Earth and Planetary Science Letters, Vol. 317-318, pp. 204-217.MantleGeodynamics
DS201312-0116
2013
Bunge, H-P.Butterworth, N.P., Talsman, A.S., Muller, R.D., Seton, M., Bunge, H-P., Schuberth, B.S.A., Shephard, G.E., Heine, C.Geological, tomographic, kinematic and geodynamic constraints on the dynamics of sinking slabs.Earth Science Reviews, Vol. 126, pp. 235-249.MantleSubduction
DS201412-0087
2014
Bunge, H-P.Butterworth, N.P., Talsma, A.S., Muller, R.D., Seton, M., Bunge, H-P., Schuberth, B.S.A., Shephard, G.E., Heine, C.Geological, tomographic, kinematic and geodynamic constraints on the dynamics of sinking slabs.Journal of Geodynamics, Vol. 73, pp. 1-13.MantleSubduction
DS201504-0228
2015
Bunge, H-P.Vynntska, L., Bunge, H-P.Restoring past mantle convection structure through fluid dynamic inverse theory: regularization through surface velocity boundary conditions.International Journal of Geomathematics, Vol. 6, 1, pp. 83-100.MantleGeodynamics
DS201801-0007
2018
Bunge, H-P.Bunge, H-P., Glasmacher, U.A.Models and observations of vertical motion ( MoveOn) associated with rifting to passive margins. PrefaceGondwana Research, Vol. 53, 1, pp. 1-8.Mantlerifting

Abstract: Two recent co-ordinated research programs - the SAMPLE (South Atlantic Margin Processes and Links with onshore Evolution) program of the German Science Foundation and the French Topo-Africa program - have focused attention on the interaction of the lithosphere with sublithospheric processes. With a main thrust on the West-Gondwana break up and the subsequent post-rift evolution of the South Atlantic passive margins and their hinterlands, SAMPLE and Topo-Africa made concerted efforts to advance models and observations of vertical motions (MoveOn) in the South Atlantic region as a probe into mantle convection/lithosphere interaction. In this special issue of Gondwana Research we assemble a set of contributions that stem from these programs aimed to gain insights on rifting in a geodynamic context with a particular focus on models and observations of the vertical motions of the lithosphere induced by mantle flow. Anderson (1982) suggested that breakup of the supercontinent Gondwana owed to forces in the sublithospheric mantle. However, despite much progress in mantle flow modeling (see Zhong and Liu, 2016 for a recent review), linking mantle convection forces and motion of the lithosphere in quantitative terms has remained elusive. It is generally accepted that plate tectonics is a surface expression of mantle convection and that mantle flow drives horizontal plate motion (Davies, 1999). However, plate tectonic motion reflects a balance of poorly known sublithospheric forces related to mantle flow, and of shallow plate-boundary forces (see Iaffaldano and Bunge, 2015 for a recent review). The latter involve topographic loads from mountain belts and fault friction along convergent plate boundaries (Iaffaldano and Bunge, 2009). Rates of change of plate velocities connect to changes in orogenic topography (Iaffaldano et al., 2006; Austermann and Iaffaldano, 2013) or plate boundary strength (Iaffaldano, 2012), making it possible to reduce some uncertainty on plate boundary forces from the analysis of plate motion changes. But the superposition of sublithospheric forces and shallow plate-boundary forces inhibits interpretations of horizontal plate motions solely in terms of mantle flow related forces. It is also believed that substantial vertical deflections of the earth's surface are induced by viscous stresses from the mantle (e.g., Pekeris, 1935). Such deflections were recognized early on in the sedimentary record through unconformities and missing sections (e.g., Stille, 1919, 1924). Termed ‘Dynamic Topography’ by Hager et al. (1985) > 30 years ago, this topic has received much attention lately (see Braun, 2010 for a recent review). The essential role of dynamic topography in dynamic earth models is well understood, because the mass anomalies associated with surface deflections yield gravity anomalies of comparable amplitude to the flow inducing mantle density variations. Therefore, Geoid interpretations have long been performed with dynamic earth models that account for dynamic topography as well as mantle density heterogeneity (e.g., Ricard et al., 1984; Richards and Hager, 1984; Forte and Mitrovica, 2001). The dynamic topography response of earth models to internal loads (e.g., hot rising plumes or cold sinking slabs) is commonly expressed through kernels (see Colli et al., 2016, for a recent review). They imply that the earth's surface sustains deflections on the order of ± 1 km. For a plume rising through a uniform viscosity mantle the kernels predict the deflections to grow continuously during plume ascend. This is borne out in laboratory models of isoviscous mantle flow (Griffith et al., 1989). However, in the presence of a weak upper mantle much of the surface deflection develops in the final phase of the plume ascend, in a time span of a few million years (Myrs) associated with vertical transit of the plume through the low viscosity upper mantle (Fig. 1). This makes rapid surface uplift events geodynamically plausible.
DS201801-0015
2018
Bunge, H-P.Friedrich, A.M., Bunge, H-P., Rieger, S.M., Ghelichkhan, S., Nerlich, R.Stratigraphic framework for the plume mode of mantle convection and the analysis of inter regional unconformities on geological maps.Gondwana Research, Vol. 53, 1, pp. 159-188.Mantleconvection

Abstract: Mantle convection is a fundamental planetary process. Its plate mode is established and expressed by plate tectonics. Its plume mode also is established and expressed by interregional geological patterns. We developed both an event-based stratigraphic framework to illustrate the surface effects predicted by the plume model of Griffiths et al. (1989) and Griffiths and Campbell (1990) and a methodology to analyze continent-scale geological maps based on unconformities and hiatuses. The surface expression of ascending plumes lasts for tens-of-millions-of-years and rates vary over a few million years. As the plume ascends, its surface expression narrows, but increases in amplitude, leaving distinct geological and stratigraphic patterns in the geologic record, not only above the plume-head center, but also above its margins and in distal regions a few thousands-of-kilometers from the center. To visualize these patterns, we constructed sequential geological maps, chronostratigraphic sections, and hiatus diagrams. Dome-uplift with erosion (?engör, 2001) and the flood basalts (Duncan and Richards, 1991; Ernst and Buchan, 2001a) are diagnostic starting points for plume-stratigraphic analyses. Mechanical collapse of the dome results in narrow rifting (Burke and Dewey, 1973), drainage-network reorganization (Cox, 1989), and flood-basalt eruption. In the marginal region, patterns of vertical movement, deformation and surface response are transient and complex. At first, the plume margin is uplifted together with the central region, but then it subsides as the plume ascents farther; With plume-head flattening, the plume margin experiences renewed outward-migrating surface uplift, erosion, broad crustal faulting, and drainage reorganization. Knickpoint migration occurs first inward-directed at ½ the rate of plume ascent and later outward-directed at the rate of asthenospheric flow. Interregional-scale unconformity-bounded stratigraphic successions document the two inversions. The distal regions, which did not experience any plume-related uplift, yield complete sedimentary records of the event; Event-related time gaps (hiatuses) in the sedimentary record increase towards the center, but the event horizon is best preserved in the distal region; it may be recognized by tracing its contacts from the center outwards. We extracted system- and series-hiatuses from interregional geological maps and built hiatus maps as proxies for paleo-dynamic topography and as a basis for comparison with results from numerical models. Interregional-scale geological maps are well suited to visualize plume-related geological records of dynamic topography in continental regions. However, geological records and hiatus information at the resolution of stages will be needed at interregional scales. The plume-stratigraphic framework is event-based, interregional, but not global, with time-dependent amplitudes that are significantly larger than those of global eustatic sea-level fluctuations. Global stratigraphic syntheses require integration of plate- and plume-stratigraphic frameworks before eustatic contributions may be assessed.
DS201112-0127
2011
Bunger, A.P.Bunger, A.P., Cruden, A.R.Modelling the growth of laccoliths and large mafic sills: role of magma body forces.Journal of Geophysical Research, Vol. 116, B2, B02203MantleMagmatism - not specific to diamonds
DS1997-0143
1997
Bungum, H.Bungum, H., Lindholm, C.Seismo- and neotectonics in Finnmark, Kola Peninsula and the southern Barents Sea: seismological analysis...Tectonophysics, Vol. 270, No. 1, 2, Feb. 28, pp. 15-28.GlobalTectonics, Geophysics - seismics
DS201607-1287
2016
Bunin, I. Zh.Bunin, I. Zh., Chanturia, V.A., Anashkina, N.E., Ryazantseva, M.V.Experimental validation of mechanism for pulsed energy effect on structure, chemical properties and microhardness of rock forming minerals of kimberlites.Journal of Mining Science, Vol. 51, 4, pp. 799-810.RussiaSpectroscopy

Abstract: Using the Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), microscopy and microhardness test methods, the change in the crystalline and chemical properties and in microhardness of rock-forming minerals of kimberlites as a result of exposure to high-power nanosecond electromagnetic pulses (HPEM) has been studied. From FTIR and XPS data the non-thermal effect of HPEM results in damage of surface microstructure of dielectric minerals due to formation of microcracks, surface breakdowns and other defects, which ensure effective weakening of rock-forming minerals and reduction in their microhardness by 40-66%.
DS201701-0005
2016
Bunin, I.Zh.Chanturia, V.A., Bunin, I.Zh., Dvoichenkova, G.P., Kovalchuk, O.E.Low temperature effects to improve efficiency of photoluminescence separation of diamonds in kimberlite ore processing.Journal of Mining Science, Vol. 52, no. 2, pp. 332-340.Russia, YakutiaDeposit - Mir

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

Abstract: The lithosphere beneath the Western Canada Sedimentary Basin has potentially undergone Precambrian subduction and collisional orogenesis, resulting in a complex network of crustal domains. To improve the understanding of its evolutionary history, we combine data from the USArray and three regional networks to invert for P-wave velocities of the upper mantle using finite-frequency tomography. Our model reveals distinct, vertically continuous high (> 1%) velocity perturbations at depths above 200 km beneath the Precambrian Buffalo Head Terrane, Hearne craton and Medicine Hat Block, which sharply contrasts with those beneath the Canadian Rockies (
DS1983-0159
1983
Bunker, B.J.Bunker, B.J., Witzke, B.J., Ludvigson, G.A.Phanerozoic Tectonism in the Central Midcontinent United States (us) Historical Aspects of Spatially Discordant Structural Patterns.Geological Society of America (GSA), Vol. 15, No. 6, P.536. (abstract.).Wisconsin, Illinois, Kansas, United States, Great LakesMid Continent
DS1985-0718
1985
Buntin, T.Weiss, D.A., Ulmer, G.C., Buntin, T., Moats, M.A.Fluid Inclusions and 10f Data: Group Ii Composite Nodules from San carlos, Arizona.Eos, Vol. 66, No. 18, APRIL 30TH. P. 392. (abstract.).United States, Arizona, Colorado PlateauBlank
DS2002-1682
2002
BuntingWalters, S., Skrzecynski, B., Whiting, Bunting, ArnoldDiscovery and geology of the Cannington Ag Pb Zn deposit Mount Isa Eastern Succession: development ...Society of Economic Geologists Special Publication, No.9,pp.95-118.AustraliaSilver, lead, zinc, exploration model Broken Hill type, Deposit - Cannington
DS1975-0751
1978
Bunting, J.A.Van De Graaff, W.J.E., Crowe, R.W.A., Bunting, J.A., Jackson, M.Relic Early Cainozoic Drainages in Arid Western AustraliaZeitschr. Geomorph., Vol. 21, No. 4, PP. 379-400.Australia, Western AustraliaDiamond, Geomorphology
DS2003-0855
2003
Bunting, J.A.Macdonald, F.A., Bunting, J.A., Cina, S.E.Yarrabubba - a large deeply eroded impact structure in the Yilgarn Craton, WesternEarth and Planetary Science Letters, Vol. 213, No. 3-4, pp. 225-247.AustraliaImpact structure - not specific to diamonds
DS200412-1188
2003
Bunting, J.A.Macdonald, F.A., Bunting, J.A., Cina, S.E.Yarrabubba - a large deeply eroded impact structure in the Yilgarn Craton, Western Australia.Earth and Planetary Science Letters, Vol. 213, no. 3-4, pp. 225-247.AustraliaImpact structure - not specific to diamonds
DS1992-0020
1992
Bunting, R.Amenta, R.V., Cooper, J.M., Bunting, R., Romeo, C.Simulating fabric development in igneous rocks: a solution for modeling space competition among growing crystalsComputers and Geosciences, Vol. 18, No. 6, pp. 763-766GlobalComputers, Igneous rocks -crystallography
DS202012-2209
2020
Buono, G.Buono, G., Fanara, S., Macedonio, G., Palladino, D.M., Petrosino, P., Sottili, G., Pappalardo, L.Dynamics of degassing in evolved alkaline magmas: petrological, experimental and theoretical insights.Earth-Science Reviews, Vol. 211, 103402, 23p. PdfMantlealkaline

Abstract: In the last few decades, advanced monitoring networks have been extended to the main active volcanoes, providing warnings for variations in volcano dynamics. However, one of the main tasks of modern volcanology is the correct interpretation of surface-monitored signals in terms of magma transfer through the Earth's crust. In this frame, it is crucial to investigate decompression-induced magma degassing as it controls magma ascent towards the surface and, in case of eruption, the eruptive style and the atmospheric dispersal of tephra and gases. Understanding the degassing behaviour is particularly intriguing in the case of poorly explored evolved alkaline magmas. In fact, these melts frequently feed hazardous, highly explosive volcanoes (e.g., Campi Flegrei, Somma-Vesuvius, Colli Albani, Tambora, Azores and Canary Islands), despite their low viscosity that usually promotes effusive and/or weakly explosive eruptions. Decompression experiments, together with numerical models, are powerful tools to examine magma degassing behaviour and constrain field observations from natural eruptive products and monitoring signals. These approaches have been recently applied to evolved alkaline melts, yet numerous open questions remain. To cast new light on the degassing dynamics of evolved alkaline magmas, in this study we present new results from decompression experiments, as well as a critical review of previous experimental works. We achieved a comprehensive dataset of key petrological parameters (i.e., 3D textural data for bubbles and microlites using X-ray computed microtomography, glass volatile contents and nanolite occurrence) from experimental samples obtained through high temperature-high pressure isothermal decompression experiments on trachytic alkaline melts at super-liquidus temperature. We explored systematically a range of final pressures (from 200 to 25 MPa), decompression rates (from 0.01 to 1 MPa s?1), and volatile (H2O and CO2) contents. On these grounds, we integrated coherently literature data from decompression experiments on evolved alkaline (trachytic and phonolitic) melts under various conditions, with the aim to fully constrain the degassing mechanisms and timescales in these magmas. Finally, we simulated numerically the experimental conditions to evaluate strengths and weaknesses in decrypting degassing behaviour from field observations. Our results highlight that bubble formation in evolved alkaline melts is primarily controlled by the initial volatile (H2O and CO2) content during magma storage. In these melts, bubble nucleation needs low supersaturation pressures (? 50-112 MPa for homogeneous nucleation, ? 13-25 MPa for heterogeneous nucleation), resulting in high bubble number density (~ 1012-1016 m?3), efficient volatile exsolution and thus in severe rheological changes. Moreover, the bubble number density is amplified in CO2-rich melts (mole fraction XCO2 ? 0.5), in which continuous bubble nucleation predominates on growth. These conditions typically lead to highly explosive eruptions. However, moving towards slower decompression rates (? 10?1 MPa s?1) and H2O-rich melts, permeable outgassing and inertial fragmentation occur, promoting weakly explosive eruptions. Finally, our findings suggest that the exhaustion of CO2 at deep levels, and the consequent transition to a H2O-dominated degassing, can crucially enhance magma vesiculation and ascent. In a hazard perspective, these constraints allow to postulate that time-depth variations of unrest signals could be significantly weaker/shorter (e.g., minor gas emissions and short-term seismicity) during major eruptions than in small-scale events.
DS202109-1455
2021
Buono, G.Buono, G., Fanara, S., Macedonio, G., Palladino, D.M., Petrosino, P., Sottili, G., Pappalardo, L.Dynamics of degassing in evolved alkaline magmas: petrological, experimental and theoretical insights.Earth Science Reviews , Vol. 211, 103402, 23p. PdfMantlegeodynamics

Abstract: In the last few decades, advanced monitoring networks have been extended to the main active volcanoes, providing warnings for variations in volcano dynamics. However, one of the main tasks of modern volcanology is the correct interpretation of surface-monitored signals in terms of magma transfer through the Earth's crust. In this frame, it is crucial to investigate decompression-induced magma degassing as it controls magma ascent towards the surface and, in case of eruption, the eruptive style and the atmospheric dispersal of tephra and gases. Understanding the degassing behaviour is particularly intriguing in the case of poorly explored evolved alkaline magmas. In fact, these melts frequently feed hazardous, highly explosive volcanoes (e.g., Campi Flegrei, Somma-Vesuvius, Colli Albani, Tambora, Azores and Canary Islands), despite their low viscosity that usually promotes effusive and/or weakly explosive eruptions. Decompression experiments, together with numerical models, are powerful tools to examine magma degassing behaviour and constrain field observations from natural eruptive products and monitoring signals. These approaches have been recently applied to evolved alkaline melts, yet numerous open questions remain. To cast new light on the degassing dynamics of evolved alkaline magmas, in this study we present new results from decompression experiments, as well as a critical review of previous experimental works. We achieved a comprehensive dataset of key petrological parameters (i.e., 3D textural data for bubbles and microlites using X-ray computed microtomography, glass volatile contents and nanolite occurrence) from experimental samples obtained through high temperature-high pressure isothermal decompression experiments on trachytic alkaline melts at super-liquidus temperature. We explored systematically a range of final pressures (from 200 to 25 MPa), decompression rates (from 0.01 to 1 MPa s?1), and volatile (H2O and CO2) contents. On these grounds, we integrated coherently literature data from decompression experiments on evolved alkaline (trachytic and phonolitic) melts under various conditions, with the aim to fully constrain the degassing mechanisms and timescales in these magmas. Finally, we simulated numerically the experimental conditions to evaluate strengths and weaknesses in decrypting degassing behaviour from field observations. Our results highlight that bubble formation in evolved alkaline melts is primarily controlled by the initial volatile (H2O and CO2) content during magma storage. In these melts, bubble nucleation needs low supersaturation pressures (? 50-112 MPa for homogeneous nucleation, ? 13-25 MPa for heterogeneous nucleation), resulting in high bubble number density (~ 1012-1016 m?3), efficient volatile exsolution and thus in severe rheological changes. Moreover, the bubble number density is amplified in CO2-rich melts (mole fraction XCO2 ? 0.5), in which continuous bubble nucleation predominates on growth. These conditions typically lead to highly explosive eruptions. However, moving towards slower decompression rates (? 10?1 MPa s?1) and H2O-rich melts, permeable outgassing and inertial fragmentation occur, promoting weakly explosive eruptions. Finally, our findings suggest that the exhaustion of CO2 at deep levels, and the consequent transition to a H2O-dominated degassing, can crucially enhance magma vesiculation and ascent. In a hazard perspective, these constraints allow to postulate that time-depth variations of unrest signals could be significantly weaker/shorter (e.g., minor gas emissions and short-term seismicity) during major eruptions than in small-scale events.
DS1990-1351
1990
Burakov, A.M.Shishkin, Y.P., Mikulevi..., A.P., Burakov, A.M.Experimental studies of nonexplosive loosening of permafrost rocks in adiamond depositSoviet Mining S.R., Vol. 26, No. 4, Jul-Aug, pp. 362-366. # HB343RussiaDiamond, Mining
DS1995-1619
1995
Burakov, B.E.Rudashevsky, N.S., Burakov, B.E., Lupal, S.D., et al.Liberation of accessory minerals from various rock types by electric pulse disintegration -method/applyInstitute of Mining and Metallurgy (IMM) Bulletin., Vol. 104, pp. C25-29.Russia, KazakhstanMetamorphic diamond deposit example
DS1995-0567
1995
Burbank, D.W.Friedmann, S.J., Burbank, D.W.Rift basins and supradetachment basins: intracontinental extensional endmembersBasin Research, Vol. 7, pp. 109-127Baikal, Mozambique, New JerseyBasins, Tectonics
DS2002-0226
2002
Burbank, D.W.Burbank, D.W.Rates of erosion and their implications for exhumationMineralogical Magazine, Vol.66,1,pp. 25-62.GlobalSubduction, Tectonics
DS200912-0071
2009
Burbidge, D.R.Braun, J., Burbidge, D.R., Gesto, Sandford, Gleadow, Kohn, CumminsConstraints on the current rate of deformation and surface uplift of the Australian continent from a new seismic database and low T thermochronological data.Australian Journal of Earth Sciences, Vol. 56, 2, pp. 99-110.AustraliaGeophysics - seismic
DS200412-0242
2004
Burbridge, D.R.Burbridge, D.R.Thin plate neotectonic models of the Australian plate.Journal of Geophysical Research, Vol. 109, B10, B10405 10.1029/2004 JBO3156AustraliaGeophysics - seismics, tectonics
DS2001-1097
2001
Burchard, M.Sobolev, N.V., Schertl, H.P., Burchard, M., Shatsky, V.An unusual pyrope grossular garnet and its paragenesis from Diamondiferous carbonate silicate rocks KokchetavDoklady Academy of Sciences, Vol. 380, No. 7, Sept-Oct. pp.791-4.Russia, KazakhstanMineralogy - pyrope, Deposit - Kokchetav Massif
DS200612-1073
2005
Burchard, M.Perchuk, A.L., Burchard, M., Maresch, W.V., Schertl, H-P.Fluid mediated modification of garnet interiors under ultrahigh pressure conditions.Terra Nova, Vol. 17, 6, pp. 545-553.MantleUHP
DS201012-0573
2009
Burchard, M.Perchuk, A.L., Davydova, V.V., Burchard, M., Maresch, W.V., Schertl, H.P., Yapaskurt, V.O., Safonov, O.G.Modification of mineral inclusions in garnet under high pressure conditions: experimental simulation and application to carbonate silicate rocks of KokchetetavRussian Geology and Geophysics, Vol. 50, 12, pp. 1153-1168.RussiaMineralogy
DS1988-0094
1988
Burchell, S.P.Burchell, S.P.Seperation of diamonds from ganguePatent: PCT International Appl. 88 01378 a1, feb 25, 1988, Chemical Abstracts CA149009GlobalDiamond recovery -Laser radiation, BP Co. Ltd. Chemical Abst
DS202112-1938
2020
Burchenia, A.V.Lysakovskyi, V.V., Ivakhnenko, S.O., Kvasntsya, V.M., Kovalenko, T., Burchenia, A.V. Features of morphogenesis of diamond single crystals more than 2 carats grown by temperature gradient method.Journal of Crystal Growth, Vol. 550, 12890, 6p. PdfGlobalsynthetics

Abstract: The morphology of ultra-large polyhedra of diamond grown under high pressure and high temperature (5.6-5.8 GPa and 1400-1700 °C) in a growth system based on Fe-Co was studied. The grown diamond polyhedra are crystals of an octahedral habit with minor faces of a cube, rhombic dodecahedron, and trapezohedrons {3 1 1}, {5 1 1} and {7 1 1}. The morphological features of the grown crystals are the skeletal growth of faces of various simple forms and the so-called "binary growth" of single crystal. The characteristic of these growth phenomena is given and possible reasons for their manifestation are described.
DS202112-1939
2021
Burchenia, A.V.Lysakovskyi, V.V., Ivakhnenko, S.O.. Kovalenko, T., Burchenia, A.V. Morphology of diamond single crystals grown in Fe-Co-Ti(Zr)-C system.Journal of Crystal Growth, Vol. 578 126422 6p. pdfRussiadiamond morphology

Abstract: The morphology of diamond single crystals grown under high pressure and high temperature (5.5 - 6.5 GPa and 1400 - 1700 °C) in the Fe-Co-Ti(Zr)-C system was studied. For growth systems based on Fe-Co doped with Ti and Zr, the sequence of change of habit types can be represented as cube-octahedron ? tetragon-trioctahedron ? octahedron. It was showed that the highest quality crystals have a tetragon-trioctahedron-octahedral habit.
DS1982-0125
1982
Burchett, R.R.Burchett, R.R.Regional Tectonics and Seismicity of Eastern NebraskaGeological Society of America (GSA), Vol. 14, No. 3, P. 107, (abstract.).GlobalMid-continent
DS1983-0160
1983
Burchett, R.R.Burchett, R.R., Luza, K.V., Van eck, O.J., Wilson, F.W.Seismicity and Tectonic Relationships of the Nemaha Uplift And Midcontinent Geophysical Anomaly.National Technical Information Service NUREG-CR 3117, 122P.GlobalMid-continent
DS1985-0096
1985
Burchett, R.R.Burchett, R.R., Luza, K.V., Van eck, O.J., Wilson, F.W.Seismicity and tectonic relationships of the Nemaha uplift and midcontinent geophysical anomaly (final report summary)Oklahoma Geological Survey Special Report, No. 85-2, 33pMidcontinent, Gulf Coast, OklahomaGeophysics, Tectonics
DS1989-1190
1989
Burchfiel, B.C.Peizhen Zhang, Burchfiel, B.C., Shefa Chen, Qidong DengExtinction of pull-apart basinsGeology, Vol. 17, No. 9, September pp. 814-817ChinaBasins, Tectonics
DS1992-0188
1992
Burchfiel, B.C.Burchfiel, B.C.The Cordilleran Orogen: conterminous U.SGeology of North America DNAG volume, No. G-3, 700pCordilleraBook -table of contents, Plate tectonics, paleogeography, orogen, metamorphism
DS1996-0194
1996
Burchfiel, B.C.Burchfiel, B.C., Zhiliang, C., Royden, L.H.Tectonics of the Longmen Shan and adjacent regions, central ChinaInternational Geology Review, Vol. 37, No. 8, Aug. pp. 661-735.ChinaTectonics
DS200412-0243
2004
Burchfiel, B.C.Burchfiel, B.C.New technology; new geological challenges. 2003 presidential address.GSA Today, Vol. 14, 2, pp. 4-9.ChinaTibetan Plateau, tectonics, GIS
DS200812-0977
2008
Burchfiel, B.C.Royden, L.H., Burchfiel, B.C., Van der Hilst, R.D.The geological evolution of Tibetan Plateau.Science, Vol. 321, no. 5892, August 22, pp. 1054-1058.Asia, TibetTectonics
DS1910-0033
1910
Burdicks, G.Burdicks, G.The Gold and the Diamond Fields, TransvaalCape Town: G. Burdicks And Co., South AfricaHistory
DS201112-0099
2011
BureauBoulard, 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
DS1999-0102
1999
Bureau, H.Bureau, H., Keppler, H.Complete miscibility between silicate melts and hydrous fluids in the uppermantle: experimental evidence...Earth and Planetary Science Letters, Vol. 165, No. 2, Jan. 30, pp. 187-96.MantleGeochemistry, Silicates
DS201112-0321
2011
Bureau, H.Fiquet, G., Auzende, A.L., Siebert, J., Corgne, A., Bureau, H., Ozawa, H., Garbarino, G.Melting of peridotite to 140 GPa.Goldschmidt Conference 2011, abstract p.848.MantleGeotherms
DS201212-0098
2012
Bureau, H.Bureau, H., Langenhorst, F., Auzende, A-L., Frost, D.J., Esteve, I., Siebert, J.The growth of fibrous, cloudy and polycrystalline diamonds.Geochimica et Cosmochimica Acta,, Vol. 77, pp. 202-214.TechnologyDiamond morphology
DS201412-0151
2014
Bureau, H.Crepisson, C., Morard, G., Bureau, H., Prouteau, G., Morizet, Y., Petitgirard, S., Sanloup, C.Magmas trapped at the continental lithosphere-asthenosphere boundary.Earth and Planetary Science Letters, Vol. 393, pp. 105-112.MantleBoundary, magmatism
DS201412-0640
2014
Bureau, H.Novella, D., Frost, D.J., Hauri, E.H., Bureau, H., Raepsaet, C., Roberge, M.The distribution of H2O between silicate melt and nominally anhydrous peridotite and the onset of hydrous melting in the deep upper mantle.Earth and Planetary Science Letters, Vol. 400, pp. 1-13.MantleMelting
DS201612-2282
2016
Bureau, H.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.
DS201705-0812
2017
Bureau, H.Bureau, H., Remusat, L., Esteve, I., Pinti, D., Cartigny, P.Isotopic characterization of diamond growth in fluids.European Geosciences Union General Assembly 2017, Vienna April 23-28, 1p. 19147 AbstractTechnologyDiamond inclusions

Abstract: Trapping inclusions in diamonds has been used as a diagnostic to constrain diamond growth media (e.g. Navon et al., 1994; Weiss et al., 2015) in the Earth's upper mantle. Experimental works now generate inclusion-bearing diamonds from seeds in mixtures of carbonates, graphite, and silicates in the presence of excess of pure water or saline fluids (H2O-NaCl) and investigate in more details the conditions of natural diamond growth (Bureau et al., 2012; 2016). Experiments were carried at conditions compatible with the Earth's geotherm between 6-7 GPa (1300-1675°C) in multi-anvil presses at the Bayerisches Geoinstitut, Bayreuth from a few hours two a few days. Results show that within the timescale of the experiments diamond growth occurs on seeds if water and alkali-bearing carbonates are present. We show that water promotes fast diamond growth, which is favorable to the formation of inclusions. Thin sections of a few diamond seeds containing exposed inclusions were prepared using a Focus Ion Beam (about 2 to 5 µm thickness). These sections were deposited on silicon wafers and gold coated for micron-scale determination of the delta 13C isotopic compositions using the NanoSIMS 50 installed at the Muséum National d'Histoire Naturelle, Paris. Carbon isotope measurement with NanoSIMS were calibrated against a natural Ia and a synthetic IIa diamond used for diamond anvil cells, whose compositions were determined by gas-source mass spectrometry at IPGP at 3.6±0.1‰ and -20.9±0.1‰, respectively (Pinti et al., 2016). All the starting materials used for the experiments were also characterized for their delta 13C by the same technique at GEOTOP, Montréal. The isotopic composition of the new diamond grown areas were measured close to the inclusions. They exhibit a different isotopic signature than that of the starting seeds (starting diamond composition: -29.6 to -30.4±1.4‰). The new diamond signatures are falling into the range of signatures of the starting carbonates used for the experiments (- 4.8±0.1 to -16.2±0.1‰) when they are far away from the composition of the starting graphite (-26.4±0.1‰). This shows that the carbon source for diamond growth must be the carbonates present either as CO32- ions dissolved in the melt or as carbon dioxide species CO2 in the aqueous fluid and that diamond growth occurred from carbonate reduction rather that from graphite dissolved in the melt. We suggest that the presence of small discrete or isolated volumes of water-carbonate-rich fluids are necessary to grow inclusion-bearing peridotitic, eclogitic, fibrous, cloudy and coated diamonds, and may also be involved in the growth of ultrahigh pressure metamorphic diamonds.
DS201706-1101
2017
Bureau, H.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.
DS201709-1966
2017
Bureau, H.Bureau, H., Remusat, L., Esteve, I., Pinti, L., Cartigny, P.The carbon source for lithospheric diamonds.Goldschmidt Conference, abstract 1p.Mantlecarbon

Abstract: Trapping inclusions in diamonds during growth experiments is used as a diagnostic to constrain natural diamond formation conditions in the Earth’s lithosphere. Isotopic signature of the new diamond grown areas close to those inclusions is also useful to identify the carbon source for the diamonds. In this study experiments were carried at conditions compatible with the Earth’s geotherm between 6-7 GPa (1300-1675°C) in multi-anvil presses from a few hours to a few days. Carbon-bearing starting materials are powders of carbonates and graphite. Results show that within the timescale of the experiments diamond growth occurs on preexisting seeds if water and alkali-bearing carbonates are present. The ?13C isotopic composition of the new diamond grown areas measured close to the inclusions show a different isotopic signature than that of the starting seeds (-29.6 to - 30.4±1.4‰). The new diamond carbon signatures are falling into the range of signatures of the starting carbonates used for the experiments (-4.8±0.1 to -16.2±0.1‰) but far away from the composition of the starting graphite (-26.4±0.1‰). This suggests that the carbon source for diamond growth at the conditions of the lithosphere must be the carbonates present either as CO3 2- ions dissolved in the melt or as carbon dioxide in the aqueous fluid. It is concluded that diamond growth occurred from carbonate reduction rather that from graphite dissolution in the melt.
DS201807-1481
2018
Bureau, H.Bureau, H., Remusat, L., Esteve, I., Pinti, D.L., Cartigney, P.The growth of lithospheric diamonds. ( inclusions and carbon isotope fractionation)Science Advances, Vol. 4, 6, doi:10.1126/ sciadv.aat1602Mantlediamond morphology

Abstract: Natural diamonds contain mineral and fluid inclusions that record diamond growth conditions. Replicating the growth of inclusion-bearing diamonds in a laboratory is therefore a novel diagnostic tool to constrain the conditions of diamond formation in Earth’s lithosphere. By determining the carbon isotopic fractionation during diamond growth in fluids or melts, our laboratory experiments revealed that lithospheric monocrystalline and fibrous and coated diamonds grow similarly from redox reactions at isotopic equilibrium in water and carbonate-rich fluids or melts, and not from native carbon. These new results explain why most of the lithospheric diamonds are characterized by a common carbon isotopic fingerprint, inherited from their common parent fluids and not from the mantle assemblage.
DS201809-2014
2018
Bureau, H.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.
DS201904-0757
2019
Bureau, H.Malavergegne, V., Bureau, H., Raepsaet, C., Gaillard, C., Poncet, F., Surble, M., Sifre, S., Shcheka, D., Fourdrin, S., Deldicque, C., Khodja, D., HichamExperimental constraints on the fate of H and C during planetary core-mantle differentiation. Implications for the Earth.Icarus - New York, Vol. 321, 1, pp. 473-485.Mantlecarbon

Abstract: Hydrogen (H) and carbon (C) have probably been delivered to the Earth mainly during accretion processes at High Temperature (HT) and High Pressure (HP) and at variable redox conditions. We performed HP (1-15?GPa) and HT (1600-2300°C) experiments, combined with state-of-the-art analytical techniques to better understand the behavior of H and C during planetary differentiation processes. We show that increasing pressure makes H slightly siderophile and slightly decreases the highly siderophile nature of C. This implies that the capacity of a growing core to retain significant amounts of H or C is mainly controlled by the size of the planet: small planetary bodies may retain C in their cores while H may have rather been lost in space; larger bodies may store both H and C in their cores. During the Earth's differentiation, both C and H might be sequestrated in the core. However, the H content of the core would remain one or two orders of magnitude lower than that of C since the (H/C)core ratio might range between 0.04 and 0.27.
DS201910-2246
2019
Bureau, H.Bureau, H., Raepsat, V., Esteve, I., Armstrong, K., Manthilake, G.Replicate mantle diamonds.Goldschmidt2019, 1p. AbstractMantlediamond genesis

Abstract: Still today, diamond growth in the mantle is difficult to understand. It may implicate different processes but there is an agreement to involve fluids as diamonds parents. The composition of these fluids is supposed to be variable depending of the the settings and depths. Natural diamonds also exhibit dissolution features, possibly mantle-derived and not only due to kimberlite-induced resorption during magma ascent [1]. We present experimental results devoted to understand diamond growth versus dissolution mechanisms in the lithosphere. Experiments are performed using multianvil presses at 7 GPa, 1300-1675°C for a few hours (4 to 27 hrs). As starting materials we use mixtures of water, carbonates, natural lherzolite or MORB, graphite and diamonds seeds resulting in hydrous-carbonate-silicate fluids at high pressure and temperature. For similar pressure and temperature conditions, results show that diamonds are formed or dissolved in these fluids, depending on the redox conditions. Focussed ion beam preparations of the diamonds evidence that when they grow, they trap multi-phased inclusions similar to those observed in fibrous, coated and monocrystalline natural diamonds, in agreement with previous studies [2-4].
DS201912-2825
2020
Bureau, H.Shirey, S.B., Smit, K.V., Pearson, D.G., Walter, M.J., Aulbach, S., Brenker, F.E., Bureau, H., Burnham, A.D., Cartigny, P., Chacko, T., Frost, D.J., Hauri, E.H., Jacob, D.E., Jacobsen, S.D., Kohn, S.C., Luth, R.W., Mikhail, S., Navon, O., Nestola, F., NimDiamonds and the mantle geodynamics of carbon: deep mantle carbon and evolution from the diamond record.IN: Deep carbon: past to present, Orcutt, Daniel, Dasgupta eds., pp. 89-128.Mantlegeodynamics

Abstract: The science of studying diamond inclusions for understanding Earth history has developed significantly over the past decades, with new instrumentation and techniques applied to diamond sample archives revealing the stories contained within diamond inclusions. This chapter reviews what diamonds can tell us about the deep carbon cycle over the course of Earth’s history. It reviews how the geochemistry of diamonds and their inclusions inform us about the deep carbon cycle, the origin of the diamonds in Earth’s mantle, and the evolution of diamonds through time.
DS202001-0039
2020
Bureau, H.Shirey, S.B., Smit, K.V., Pearson, D.G., Walter, M.J., Aulbach, S., Brenker, F.E., Bureau, H., Burnham, A.D., Cartigny, P., Chacko, T., Frost, D.J., Hauri, E.H., Jacob, D.E., Jacobsen, S.D., Kohn, S.C., Luth, R.W., Mikhail, S., Navon, O., Nestola, F., NimDiamonds and mantle geodynamics of carbon: IN: Deep Carbon: past to present. Editors Orcutt, Danielle, Dasgupta, pp. 89-128.Mantlegeodynamics

Abstract: The science of studying diamond inclusions for understanding Earth history has developed significantly over the past decades, with new instrumentation and techniques applied to diamond sample archives revealing the stories contained within diamond inclusions. This chapter reviews what diamonds can tell us about the deep carbon cycle over the course of Earth’s history. It reviews how the geochemistry of diamonds and their inclusions inform us about the deep carbon cycle, the origin of the diamonds in Earth’s mantle, and the evolution of diamonds through time.
DS202002-0206
2020
Bureau, H.McCammon, C., Bureau, H., Cleaves II, H.J., Cottrell, E., Dorfman, S.M., Kellogg, L.H., Li, J., Mikhail, S., Moussallam, Y., Sanloup, C., Thomson, A.R., Brovarone, A.V.Deep Earth carbon reactions through time and space. ( mentions diamond)American Mineralogist, Vol. 105, pp. 22-27.Mantlesubduction

Abstract: Reactions involving carbon in the deep Earth have limited manifestations on Earth's surface, yet they have played a critical role in the evolution of our planet. The metal-silicate partitioning reaction promoted carbon capture during Earth's accretion and may have sequestered substantial carbon in Earth's core. The freezing reaction involving iron-carbon liquid could have contributed to the growth of Earth's inner core and the geodynamo. The redox melting/freezing reaction largely controls the movement of carbon in the modern mantle, and reactions between carbonates and silicates in the deep mantle also promote carbon mobility. The 10-year activity of the Deep Carbon Observatory has made important contributions to our knowledge of how these reactions are involved in the cycling of carbon throughout our planet, both past and present, and has helped to identify gaps in our understanding that motivate and give direction to future studies.
DS202107-1128
2019
Bureau, H.Shirey, S.B., Smit, K.V., Pearson, D.G., Walter, M.J., Aulbach, S., Brenker, F.E., Bureau, H., Burnham, A.D., Cartigny, P., Chacko, T., Frost, D.J., Hauri, E.H., Jacob, D.E., Jacobsen, S.D., Kohn, S.C., Luth, R.W., Mikhail, S., Navon, O.. Nestola, F., NimDiamonds and mantle geodynamics of carbon.Deep Carbon - Cambridge University Press , Cambridge.org 40p. PdfMantlecarbon
DS1950-0373
1958
Bureau, R.Bureau, R.Les Diamants de QuebecCan. Naturalist., Vol. 85, No. 11-12, PP. 229-238. ALSO: University LAVAL FACULTE SCanada, QuebecDiamond Occurrences
DS1975-0968
1979
Bureau De Recherches Geologiques Et MinieresBureau De Recherches Geologiques Et MinieresSection 12. DiamantBureau De Recherche Geologiques Et Minieres, Direction Cayenne., PP. 92-97.South America, GuianaDiamond Prospecting
DS200812-0153
2007
Burek, C.V.Burek, C.V., Higgs, B.The role of women in the history of geology.New books, Tables of contents and costsGlobalGeneral interest?
DS1988-0362
1988
Burenkov, E.K.Kogan, B.S., Ginzburg, L.N., Burenkov, E.K.Investigation of the spatial structures of geochemical fields for prospecting purposesInternational Geology Review, Vol. 30, No. 10, October pp. 1141-1146. Database # 1787RussiaComputer, Program -GEOSCAN Geochemistry
DS1950-0374
1958
Burenkov, M.I.Burenkov, M.I.Skvoz Taezhnye Debri Gosudarstvennoe IzdatstvoMoscow:, 81P.Russia, SiberiaKimberlite, Kimberley, Diamond, Taiga
DS200412-2118
2004
BurgWilliams, H.M., McCammon, C.A., Peslier, Halliday, Teutsch, Levasseur, BurgIron isotope fractionation and the oxygen fugacity of the mantle.Geochimica et Cosmochimica Acta, 13th Goldschmidt Conference held Copenhagen Denmark, Vol. 68, 11 Supp. July, ABSTRACT p.A563.MantleMelting
DS1940-0043
1942
Burg, G.Burg, G.Die Nutzbaren Minerallagerstaetten von Deutsch SuedwestafrikBerlin: Walter De Gruyter And Co., Mitt. Gruppe Dt. Kolonwirt., 305P.Southwest Africa, NamibiaGeology, Kimberley, Mineral Resources
DS1994-0235
1994
Burg, J.P.Burg, J.P., Davy, P., Martinod, J.Shortening of analogue models of the continental lithosphere: new hypothesis for the formation Tibetan plateau.Tectonics, Vol. 13, No. 2, Apr. pp. 475-83.ChinaTectonics
DS1996-0195
1996
Burg, J.P.Burg, J.P., Ford, M.Orogeny through time #1Geological Society of London, No. 121, 272p. approx. $ 99.00 United StatesGlobalOrogeny through time, Book -ad
DS1997-0144
1997
Burg, J.P.Burg, J.P., Ford, M.Orogeny through time #2Geological Society of London, Publ, No. 121, 250pAustraliaBook - table of contents, Orogeny, Rheology, lithosphere
DS2002-1414
2002
Burg, J.P.Schaltegger, U., Zeilinger, G., Frank, M., Burg, J.P.Multiple mantle sources during island arc magmatism. U Pb and Hf isotopic evidence from the Kohistan arc complex, Pakistan.Terra Nova, Vol. 14, 6, pp. 46-8.PakistanMagmatism - not specific to diamonds. Geochronology
DS200512-1179
2005
Burg, J.P.Williams, H.M., Peslier, A.H., McCammon, C., Halliday, A.N., Levasseur, S., Teutsch, N., Burg, J.P.Systematic iron isotope variations in mantle rocks and minerals: the effects of partial melting and oxygen fugacity.Earth and Planetary Science Letters, Advanced in press,MantleMelting
DS200512-1180
2005
Burg, J.P.Williams, H.M., Peslier, A.H., McCammon, C., Halliday, A.N., Levasseur, S., Teutsch, N., Burg, J.P.Systematic iron isotope variations in mantle rocks and minerals. The effects of partial melting and oxygen fugacity.Earth and Planetary Science Letters, Vol. 235, 1-2, pp. 435-452.MantleGeochronology, melting
DS201012-0439
2010
Burg, J.P.Li, H., Gerya, T.V., Burg, J.P.Influence of tectonic overpressure on P-T paths of HP-UHP rocks in continental collision zones: thermomechanical modeling.Journal of Metamorphic Geology, Vol. 28, 3, pp. 227-247.MantleUHP
DS1993-0198
1993
Burg, J-P.Camire, G.E., Burg, J-P.Late Archean thrusting in the Northwestern Pontiac Subprovince, CanadianShieldPrecambrian Research, Vol. 61, No. 1-2, February pp. 51-66OntarioStructure -thrust, Pontiac Subprovince
DS200412-2117
2004
Burg, J-P.Williams, H.M., McCammon, C.A., Peslier, A.H., Halliday, A.N., Teutsch, N., Levasseur, S., Burg, J-P.Iron isotope fractionation and the oxygen fugacity of the mantle.Science, Vol. 304, 5677, June 11, p. 1656.MantleGeothermobarometry
DS200712-0374
2007
Burg, J-P.Gorczyk, W.A., Gerya, T.V., Connolly, J.A.D., Burg, J-P., Yuen, D.A.Melting and mixing processes in mantle wedges.Plates, Plumes, and Paradigms, 1p. abstract p. A346.MantleMelting
DS201904-0738
2019
Burg, J-P.Galli, A., Grassi, D., Sartori, G., Gianola, O., Burg, J-P., Schmidt, M.W.Jurassic carbonatite and alkaline magmatism in the Ivrea zone ( European Alps) related to the breakup of Pangea.Geology, Vol. 47, 3, pp. 199-202..Europecarbonatite

Abstract: We report on pipe-like bodies and dikes of carbonate rocks related to sodic alkaline intrusions and amphibole mantle peridotites in the Ivrea zone (European Southern Alps). The carbonate rocks have bulk trace-element concentrations typical of low-rare earth element carbonatites interpreted as cumulates of carbonatite melts. Faintly zoned zircons from these carbonate rocks contain calcite inclusions and have trace-element compositions akin to those of carbonatite zircons. Laser ablation-inductively coupled plasma-mass spectrometry U-Pb zircon dating yields concordant ages of 187 ± 2.4 and 192 ± 2.5 Ma, coeval with sodic alkaline magmatism in the Ivrea zone. Cross-cutting relations, ages, as well as bulk and zircon geochemistry indicate that the carbonate rocks are carbonatites, the first ones reported from the Alps. Carbonatites and alkaline intrusions are comagmatic and were emplaced in the nascent passive margin of Adria during the Early Jurassic breakup of Pangea. Extension caused partial melting of amphibole-rich mantle domains, yielding sodic alkaline magmas whose fractionation led to carbonatite-silicate melt immiscibility. Similar occurrences in other rifts suggest that small-scale, sodic and CO2-rich alkaline magmatism is a typical result of extension and decompression-driven reactivation of amphibole-bearing lithospheric mantle during passive continental breakup and the evolution of magma-poor rifts.
DS201911-2510
2019
Burg, J-P.Beaussier, S.J., Gerya, T.V., Burg, J-P.3D numerical modelling of the Wilson cycle: structural inheritance of alternating subduction polarity.N: Cycle Concepts in Plate Tectonics, editors Wilson and Houseman , Geological Society of London special publication 470, 439-461.Mantleplate tectonics

Abstract: Alternating subduction polarity along suture zones has been documented in several orogenic systems. Yet the mechanisms leading to this geometric inversion and the subsequent interplay between the contra-dipping slabs have been little studied. To explore such mechanisms, 3D numerical modelling of the Wilson cycle was conducted from continental rifting, breakup and oceanic spreading to convergence and self-consistent subduction initiation. In the resulting models, near-ridge subduction initiating with the formation of contra-dipping slab segments is an intrinsically 3D process controlled by earlier convergence-induced ridge swelling. The width of the slab segments is delimited by transform faults inherited from the rifting and ocean floor spreading stages. The models show that the number of contra-dipping slab segments depends mainly on the size of the oceanic basin, the asymmetry of the ridge and variations in kinematic inversion from divergence to convergence. Convergence velocity has been identified as a second-order parameter. The geometry of the linking zone between contra-dipping slab segments varies between two end-members governed by the lateral coupling between the adjacent slab segments: (1) coupled slabs generate wide, arcuate linking zones holding two-sided subduction; and (2) decoupled slabs generate narrow transform fault zones against which one-sided, contra-dipping slabs abut.
DS1989-0191
1989
Burgath, K.P.Burgath, K.P., Mohr, M., Simandjuntak, W.Aspects of diamond origin in southeast Kalimantan, Indonesia79th. Annual Meeting Of The Geologische Vereinigung, Mineral, p. 51-52. (abstract.)Indonesia, KalimantanDiamond genesis
DS1975-0969
1979
Burgemeister, E.A.Burgemeister, E.A.Thermal Conductivities of Diamonds With Absorption at 3.22 UmNature, Vol. 279, June 28, pp. 785-6.GlobalDiamond Morphology, Thermal Conductivity
DS1960-0281
1962
Burger, A.J.Nicholson, L.O., Burger, A.J., Johnson, R.L.The Age of the Shawa Carbonatite ComplexGeological Society of South Africa Transactions, Vol. 65, PT. 1, PP. 293-294.ZimbabweGeology, Related Rocks, Geochronology
DS1960-0777
1967
Burger, A.J.Allsop, H.L., Burger, A.J., Van zyl, C.A Minimum Age for the Premier Kimberlite Pipe Yielded by Biotite Rubidium-strontium (rb-sr) Measurements, with Related Galena Isotopic Data.Earth and Planetary Science Letters, Vol. 3, No. 2, PP. 161-166.South AfricaGeochronology, Isotope
DS1975-0710
1978
Burger, A.J.Burger, A.J.The Geochronology of the Luderitz GranitesPrecambrian Research. UNIT, University CAPE TOWN, Annual Report 14TH. AND, PP. 141-144.Southwest Africa, NamibiaGeology
DS2002-0227
2002
Burger, J.U.Burger, J.U.Utilization of scale model testing in the benchmarking and development of offshore sampling tools.11th. Quadrennial Iagod Symposium And Geocongress 2002 Held Windhoek, Abstract p. 20.South AfricaMarine mining - vessel sampling technology, Alluvials
DS201707-1307
2017
Burger, P.Bell, A.S., Shearer, C., Burger, P., Ren, M., Newville, M., Lanzirotti, A.Quantifying and correcting the effects of anisotropy in Xanes measurements of chromium valence in olivine: implications for a new olivine oxybarometer.American Mineralogist, Vol. 102, pp. 1165-1172.Technologyolivine

Abstract: Chromium valence ratios in igneous olivine may hold a wealth of redox information about the melts from which they crystallized. It has been experimentally shown that the Cr2+/?Cr of olivine varies systematically with fO2, therefore measurements of Cr valence in olivine could be employed as a quantitative oxybarometer. In situ synchrotron ?-XANES analyses of Cr valence ratios of individual olivine phenocrysts in thin section have the potential to unlock this stored magmatic redox information on a fine spatial scale. However, there are still obstacles to obtaining accurate XANES measurements of cation valence in crystalline materials, as the results from these measurements can be compromised by anisotropic absorption effects related to the crystallographic orientation of the sample. Improving the accuracy of XANES measurements of Cr valence ratios in olivine by calibrating an anisotropy correction is a vital step in developing Cr valence measurements in olivine as a rigorous oxybarometer. To accomplish this goal, we have used an integrated approach that combined experiments, electron backscatter diffraction analysis, and XANES measurements in olivine to systematically examine how orientation affects the resultant Cr K-edge XANES spectra and the Cr valence ratios that are calculated from them. The data set generated in this work was used to construct a model that mitigates the effects of anisotropy of the calculated Cr2+/?Cr values. The application of this correction procedure as a part of spectral processing improves the overall accuracy of the resultant Cr2+/?Cr values by nearly a factor of five. The increased accuracy of the XANES measured Cr valence ratios afforded by the anisotropy correction reduces the error on calculated fO2 values from approximately ±1.2 to ±0.25
DS1998-0528
1998
BurgessGraham, I., Burgess, bryan, Ravenscroft, Thomas, DoyleThe Diavik kimberlites - Lac de Gras, Northwest Territories, Canada7th International Kimberlite Conference Abstract, pp. 259-61.Northwest TerritoriesHistory, kimberlite, evaluation, Deposit - Diavik
DS1998-1158
1998
BurgessPhillips, D., Harris, J.W., Kiviets, Burgess, Fourie40 Ar39 Laser probe analyses of clinopyroxene diamond inclusions from the Orapa and Mbuyi Miya Mines.7th. Kimberlite Conference abstract, pp. 687-9.GlobalGeochronology, diamond inclusions, Deposit - Orapa, Mbuyi Miya
DS201710-2227
2017
Burgess, A.B.Ganey, G.Q., Loso, M.G., Burgess, A.B., Dial, R.J.The role of microbes in snowmelt and radiative forcing on an an Alaskan icefield. Red algaeNature Geoscience, Sept. 18, onlineUnited States, Alaskageomorphology

Abstract: A lack of liquid water limits life on glaciers worldwide but specialized microbes still colonize these environments. These microbes reduce surface albedo, which, in turn, could lead to warming and enhanced glacier melt. Here we present results from a replicated, controlled field experiment to quantify the impact of microbes on snowmelt in red-snow communities. Addition of nitrogen-phosphorous-potassium fertilizer increased alga cell counts nearly fourfold, to levels similar to nitrogen-phosphorus-enriched lakes; water alone increased counts by half. The manipulated alga abundance explained a third of the observed variability in snowmelt. Using a normalized-difference spectral index we estimated alga abundance from satellite imagery and calculated microbial contribution to snowmelt on an icefield of 1,900?km2. The red-snow area extended over about 700?km2, and in this area we determined that microbial communities were responsible for 17% of the total snowmelt there. Our results support hypotheses that snow-dwelling microbes increase glacier melt directly in a bio-geophysical feedback by lowering albedo and indirectly by exposing low-albedo glacier ice. Radiative forcing due to perennial populations of microbes may match that of non-living particulates at high latitudes. Their contribution to climate warming is likely to grow with increased melt and nutrient input.
DS201601-0010
2015
Burgess, A.R.Chalapathai Rao, N.V., Atiullah, Burgess, A.R.,Nanda, P., Choudhary, A.K., Sahoo, S., Lehman, B., Chahong, N.Petrology, 40Ar/39Ar, Sr-Nd isotope systematics, and geodynamic significance of an ultrapotassic ( lamproitic) dyke with affinities to kamafugite from the easternmost margin of the Bastar Craton, India.Mineralogy and Petrology, in press available, 25p.IndiaLamproites - Nuapada field

Abstract: We report the mineralogy, bulk-rock geochemistry, 40Ar/39Ar (whole-rock) age and radiogenic (Sr and Nd) isotope composition of an ultrapotassic dyke from Sakri (Nuapada lamproite field) located at the tectonic contact between the easternmost margin of the Bastar craton and Eastern Ghats Mobile Belt, India. The Sakri dyke has a mineralogy which strongly resembles a lamproite sensu stricto (viz.,Ti-rich phlogopite, Na-poor diopside, Fe-rich sanidine, ulvospinel trend and Sr-rich apatite). However, its bulk-rock major element geochemical characteristics (viz., extreme silica-undersaturated nature) resemble sensu lato kamafugite from Toro Ankole, Uganda, East African Rift, and Alto Paranaiba Province, Brazil. The Sakri dyke also displays certain compositional peculiarities (viz., high degree of evolution of mica composition from phlogopite to biotite, elevated titanium and aluminum in clinopyroxene and significantly lower bulk Mg#) when compared to the ultrapotassic rocks from various Indian cratons. 40Ar/39Ar dating gave a plateau age of 1045?±?9 Ma which is broadly similar to that of other Mesoproterozoic (i) lamproites from the Bastar and Bundelkhand cratons, and (ii) kimberlites from the Eastern Dharwar craton. Initial bulk-rock Sr (0.705865-0.709024) and Nd (0.511063-0.511154) isotopic ratios reveal involvement of an ‘enriched’ source region with long-term incompatible element enrichment and a depleted mantle (TDM) Nd model age of 2.56 Ga straddling the Archaean-Proterozoic chronostratigraphic boundary. The bulk-rock incompatible trace element ratios (Ta/Yb, Th/Yb, Rb/Ba and Ce/Y) of the Sakri ultrapotassic dyke negate any significant influence of crustal contamination. Small-degree melting (1 to 1.5 %) of a mixed garnet-facies and spinel-facies phlogopite lherzolite can account for its observed REE concentrations. Whereas the emplacement of the Sakri ultrapotassic dyke is related to the amalgamation of the supercontinent of Rodinia, its overlapping geochemical characteristics of lamproite and kamafugite (also displayed by two other lamproites of the Nuapada field at Amlidadar and Parkom) are linked to the emplacement in a unique geological setting at the craton-mobile belt contact and hence of geodynamic significance.
DS1930-0197
1935
Burgess, C.H.Larsen, E.S., Hurlburt, C.S. JR., Burgess, C.H., Griggs, D.T.The Igneous Rocks of the Highwood Mountains of Central Montana.American GEOPYS. UNION, Transactions 16TH. MEETING, PP. 288-292.United States, Montana, Rocky MountainsBlank
DS201512-1981
2015
Burgess, D.O.Van Wychen, W., Copland, L., Burgess, D.O., Gray, L., Schaffer, N., Fisher, T.Glacier velocities and dynamic discharge from the ice masses of Baffin Island and Bylot Island, Nunavut, Canada.Canadian Journal of Earth Sciences, Vol. 52, 11, pp. 980-989.Canada, Nunavut, Baffin IslandGeomorphology

Abstract: Speckle tracking of ALOS PALSAR fine beam data from 2007-2011 are used to determine the surface motion of major ice masses on Baffin Island and Bylot Island in the southern Canadian Arctic Archipelago. Glacier velocities are low overall, with peaks of ?100 m a?1 and means of ?20-60 m a?1 common along the main trunk of many outlet glaciers. Peak velocities on Penny and Bylot Island ice caps tend to occur near the mid-sections of their primary outlet glaciers, while the fastest velocities on all other glaciers usually occur near their termini due to relatively large accumulation areas draining through narrow outlets. Estimates of ice thickness at the fronts of tidewater-terminating glaciers are combined with the velocity measurements to determine a regional dynamic discharge rate of between ?17 Mt a?1 and ?108 Mt a?1, with a mid-point estimate of ?55 Mt a?1, revising downward previous approximations. These velocities can be used as inputs for glacier flow models, and provide a baseline dataset against which future changes in ice dynamics can be detected.
DS1998-0175
1998
Burgess, J.Bryan, D., Burgess, J.The Diavik project kimberlites, Slave Province, Northwest TerritoriesGeological Society of America (GSA) Annual Meeting, abstract. only, p.A245.Northwest TerritoriesExploration - history outline, Deposit - Diavik project
DS1998-0176
1998
Burgess, J.Bryan, D., Burgess, J., Graham, I., Ravenscroft, P.The Diavik kimberlites - Lac de Gras, Northwest Territories, Canada.Calgary Mining Forum, Apr. 8-9, p. 40-2. abstractNorthwest TerritoriesGeology, Deposit - Diavik
DS2001-0149
2001
Burgess, J.Burgess, J.The Diavik diamond mine - an updateNw Mining Association Meet., Dec. 7, 1p. abstr.Northwest TerritoriesNews item, Diavik
DS2001-0150
2001
Burgess, J.Burgess, J.The Diavik diamonds project - an update37th. Forum Industrial Minerals, May 23-5, pp. 115-19.Northwest TerritoriesOverview - brief, Deposit - Diavik
DS200612-1386
2005
Burgess, J.Strand, P., Burgess, J.Shear Minerals & Burgess Diamonds - exploration update: Churchill diamond project, Nunavut.32ndYellowknife Geoscience Forum, p. 72 abstractCanada, NunavutUpdate - Shear Minerals
DS200712-1047
2006
Burgess, J.Strand, P., Burgess, J.Two unique kimberlite sources at the Churchill diamond project, Nunavut.34th Yellowknife Geoscience Forum, p. 55-57. abstractCanada, NunavutSedna corridor
DS200812-1134
2007
Burgess, J.Strand, P., Banas, A., Burgess, J.Contrasting kimberlite types and dispersion trains at the Churchill diamond project Kivalliq region, Nunavut.35th. Yellowknife Geoscience Forum, Abstracts only p. 59-60.Canada, NunavutExploration - geochemistry
DS200812-1135
2008
Burgess, J.Strand, P., Baumgartner, M., Banas, A., Burgess, J.Contrasting kimberlite types of the Churchill diamond project, Nunavut: implications for exploration and evaluation.Prospectors and Developers Association of Canada, March 3, 1p. abstract.Canada, NunavutChurchill overview
DS201012-0762
2009
Burgess, J.Strand, P., Banas,A., Baumgartner, M., Burgess, J.Tracing kimberlite indicator mineral dispersal trains: an example from the Churchill diamond project, Kivalliq region, Nunavut.Geological Association of Canada Short Course, No. 18, pp. 167-176.Canada, NunavutGeochemistry, technology
DS201012-0763
2010
Burgess, J.Strand, P., Lassonde, J., Burgess, J.Transforming a diamond mine: the Jericho diamond mine update.38th. Geoscience Forum Northwest Territories, Abstract pp.87-88.Canada, NunavutJericho project
DS201212-0708
2012
Burgess, J.Strand, P., Banas, A., Burgess, J., Baumgartner, M.Two distinct kimberlite types at the Churchill diamond project, Nunavut, Canada.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractCanada, NunavutDeposit - Churchill area
DS201606-1100
2016
Burgess, J.Kopylova, M.G., Beausoleil, Y., Goncharov, A., Burgess, J., Strand, P.Spatial distribution of eclogite in the Slave Craton mantle: the role of subduction.Tectonophysics, Vol. 672-673, pp. 87-103.Canada, Northwest TerritoriesSubduction

Abstract: We reconstructed the spatial distribution of eclogites in the cratonic mantle based on thermobarometry for ~ 240 xenoliths in 4 kimberlite pipes from different parts of the Slave craton (Canada). The accuracy of depth estimates is ensured by the use of a recently calibrated thermometer, projection of temperatures onto well-constrained local peridotitic geotherms, petrological screening for unrealistic temperature estimates, and internal consistency of all data. The depth estimates are based on new data on mineral chemistry and petrography of 148 eclogite xenoliths from the Jericho and Muskox kimberlites of the northern Slave craton and previously reported analyses of 95 eclogites from Diavik and Ekati kimberlites (Central Slave). The majority of Northern Slave eclogites of the crustal, subduction origin occurs at 110-170 km, shallower than in the majority of the Central Slave crustal eclogites (120-210 km). The identical geochronological history of these eclogite populations and the absence of steep suture boundaries between the central and northern Slave craton suggest the lateral continuity of the mantle layer relatively rich in eclogites. We explain the distribution of eclogites by partial preservation of an imbricated and plastically dispersed oceanic slab formed by easterly dipping Proterozoic subduction. The depths of eclogite localization do not correlate with geophysically mapped discontinuities. The base of the depleted lithosphere of the Slave craton constrained by thermobarometry of peridotite xenoliths coincides with the base of the thickened lithospheric slab, which supports contribution of the recycled oceanic lithosphere to formation of the cratonic root. Its architecture may have been protected by circum-cratonic subduction and shielding of the shallow Archean lithosphere from the destructive asthenospheric metasomatism.
DS201611-2127
2016
Burgess, J.Newton, D.E., Kopylova, M.G., Burgess, J., Strand, P., Murphy, B.Peridotite and pyroxenite xenoliths from the Muskox kimberlite, northern Slave craton, Canada.Canadian Journal of Earth Sciences, Vol. 53, 1, pp. 41-58.Canada, Northwest TerritoriesDeposit - Muskox

Abstract: We present petrography, mineralogy, and thermobarometry for 53 mantle-derived xenoliths from the Muskox kimberlite pipe in the northern Slave craton. The xenolith suite includes 23% coarse peridotite, 9% porphyroclastic peridotite, 60% websterite, and 8% orthopyroxenite. Samples primarily comprise forsteritic olivine (Fo 89-94), enstatite (En 89-94), Cr-diopside, Cr-pyrope garnet, and chromite spinel. Coarse peridotites, porphyroclastic peridotites, and pyroxenites equilibrated at 650-1220 °C and 23-63 kbar (1 kbar = 100 MPa), 1200-1350 °C and 57-70 kbar, and 1030-1230 °C and 50-63 kbar, respectively. The Muskox xenoliths differ from xenoliths in the neighboring and contemporaneous Jericho kimberlite by their higher levels of depletion, the presence of a shallow zone of metasomatism in the spinel peridotite field, a higher proportion of pyroxenites at the base of the mantle column, higher Cr2O3 in all pyroxenite minerals, and weaker deformation in the Muskox mantle. We interpret these contrasts as representing small-scale heterogeneities in the bulk composition of the mantle, as well as the local effects of interaction between metasomatizing fluid and mantle wall rocks. We suggest that asthenosphere-derived pre-kimberlitic melts and fluids percolated less effectively through the less permeable Muskox mantle, resulting in lower degrees of hydrous weakening, strain, and fertilization of the peridotitic mantle. Fluids tended to concentrate and pool in the deep mantle, causing partial melting and formation of abundant pyroxenites.
DS201812-2832
2018
Burgess, J.Krishna, C., Pande, L., Norris, R., Howell, D., Burgess, J.Bunder deposit: The Bunder diamond project, India: discovery of the Saptarshi lamproite pipes.Society of Economic Geology Geoscience and Exploration of the Argyle, Bunder, Diavik, and Murowa Diamond Deposits, Special Publication no. 20, pp. 191-200.Indiadeposit - Bunder
DS1994-0003
1994
Burgess, L.Abbott, D., Burgess, L., Longhi, J., Smith, W.H.F.An empirical thermal history of the Earth's upper mantleJournal of Geophy. Res., Vol. 99, No. B7, July 10, pp. 13, 385-13, 850.MantleGeothermometry
DS1996-1557
1996
Burgess, M.Wolfe, S., Burgess, M., Douma, M., Hyde, C., Robinson, S.Geological and geophysical investigations of ground ice glaciofluvialdeposits, Slave Province.Northwest Territories Exploration Overview, Nov. 26, p. 3-37.Northwest TerritoriesGeological, geophysics, geomorphology, Slave Province
DS1960-0025
1960
Burgess, P.H.E.Burgess, P.H.E.Diamonds UnlimitedLondon: John Long, 190P.Tanzania, East AfricaHistory, Kimberley
DS1995-0235
1995
Burgess, P.M.Burgess, P.M., Gurnis, M., Moresi, L.N.Geodynamical contributions to the formation of North American cratonic stratigraphic sequences.Eos, Vol. 76, No. 46, Nov. 7. p.F535. Abstract.United States, Canada, North AmericaCraton, Geodynamics
DS1997-0145
1997
Burgess, P.M.Burgess, P.M., Gurnis, M., Moresi, L.N.Formation of sequences in the cratonic interior of North America by interaction between mantle, eustatic..Geological Society of America (GSA) Bulletin., Vol. 109, No. 12, Dec. pp. 1515-1535.North America, United States, Canada, Alberta, MontanaCraton, Stratigraphy, geochronology
DS1989-0192
1989
Burgess, R.Burgess, R., Turner, G., Laurenzi, M., Harris, J.W.40Ar 39Ar laser probe dating of individual clinopyroxene inclusions in Premier eclogitic diamondsEarth and Planetary Science Letters, Vol. 94, No.l 1/2, August pp. 22-28South AfricaGeochronology, Diamond Inclusions
DS1990-1484
1990
Burgess, R.Turner, G., Burgess, R., Bannon, M.Volatile rich mantle fluids inferred from inclusions in diamond and mantlexenolithsNature, Vol. 344, April 12, pp. 653-655GlobalDiamond inclusions, Geochronology
DS1992-0189
1992
Burgess, R.Burgess, R., Turner, G., Harris, J.W.40Ar 39 Ar laser probe studies of clinopyroxene inclusions in eclogiticdiamondsGeochimica et Cosmochimica Acta, Vol. 56, pp. 389-402GlobalGeochronology, eclogitic diamonds, Argon, Orapa, Jwaneng, Argyle, Udachnaya
DS1993-0189
1993
Burgess, R.Burgess, R.Noble gas and halogen measurements of volatile-rich fluids in diamondsAmerican Geophysical Union, EOS, supplement Abstract Volume, October, Vol. 74, No. 43, October 26, abstract p. 636.BotswanaGeochronology, Deposit -Jwaneng, Orapa
DS1998-0187
1998
Burgess, R.Burgess, R., Johnson, L.H., Mattey, D., Harris, TurnerHelium, Argon, and Carbon isotopes in coated and polycrystalline diamonds.Chemical Geology, Vol. 146, No. 3-4, May 5, pp. 205-218.AustraliaGeochronology, Diamond morphology
DS1998-0188
1998
Burgess, R.Burgess, R., Phillips, D., Harris, J.W., Robinson, D.N.Antarctic diamonds in south eastern Australia? Hints from 40 Ar-39AR laser probe dating of clinopyroxene..7th International Kimberlite Conference Abstract, pp. 119-121.Australia, AntarcticaAlluvials, Argon, Deposit - Copeton
DS1998-0701
1998
Burgess, R.Johnson, L.H., Burgess, R., Turner, MilledgeNoble gas and halogen systematics of fluids with diamond coats from Canada and Africa.7th International Kimberlite Conference Abstract, pp. 383-5.Northwest Territories, Botswana, ZaireDiamond inclusions, Diamond morphology - coated stones
DS1998-0702
1998
Burgess, R.Johnson, L.H., Burgess, R., Turner, MilledgeFluids trapped within diamond: clues to mantle geochemistry7th International Kimberlite Conference Abstract, pp. 380-2.South AfricaDiamond inclusions, Deposit - Venetia, Premier
DS2002-0228
2002
Burgess, R.Burgess, R., Lazelle, E., Turner, G., Harris, J.W.Constraints on the age and halogen composition of mantle fluids in Siberian coated diamonds.Earth and Planetary Science Letters, Vol.197,3-4,pp. 193-203.RussiaGeochronology, Deposit - Aikhal
DS2003-0186
2003
Burgess, R.Burgess, R., Harrison, D., Hobson, E., Harris, J.W.Noble gas and halogen constraints on the origin of volatile rich fluids in Canadian8ikc, Www.venuewest.com/8ikc/program.htm, Session 3, POSTER abstractNorthwest TerritoriesDiamonds - mineralogy, Deposit - Panda
DS2003-0187
2003
Burgess, R.Burgess, R., Kiviets, G., Harris, J.W.Different age populations of eclogitic diamonds in the Venetia kimberlite: evidence from8 Ikc Www.venuewest.com/8ikc/program.htm, Session 2, AbstractSouth AfricaDiamonds - geochronology, Deposit - Venetia
DS200412-0244
2003
Burgess, R.Burgess, R., Kiviets, G., Harris, J.W.Different age populations of eclogitic diamonds in the Venetia kimberlite: evidence from Ar Ar dating of syngenetic clinopyroxen8 IKC Program, Session 2, AbstractAfrica, South AfricaDiamonds - geochronology Deposit - Venetia
DS200412-0245
2004
Burgess, R.Burgess, R., Kiviets, G.B., Harris, J.W.Ar Ar age determinations of eclogitic clinopyroxene and garnet inclusions in diamonds from the Venetia and Orapa kimberlites.Lithos, Vol. 77, 1-4, Sept. pp. 113-124.Africa, South Africa, BotswanaGeochronology, dating
DS200512-0121
2004
Burgess, R.Burgess, R.Diamond ages.Rough Diamond Review, No. 6, Sept.pp.Geochronology, E and P
DS200612-0237
2005
Burgess, R.Chalapathi Rao, N.V., Burgess, R., Anand, M., Mainkar, D.Evidence for a Phanerozoic (478 Ma) Diamondiferous kimberlite emplacement epoch in the Indian Shield from 40 Ar/ 39Ar dating of the Kodomali kimberlite: implications ....Geological Society of India, Bangalore November Meeting Group Discussion on Kimberlites and Related Rocks India, Abstract p. 103-106.India, Bastar Craton, RodiniaTectonics - Kodomali, Pan African , Geothermometry
DS200812-0701
2008
Burgess, R.Mainkar, D., Lehmann, B., Burgess, R., Belyatsky, B.The Diamondiferous Behradih kimberlite pipe, Raipur district, Chhattisgarh, India.9IKC.com, 3p. extended abstractIndiaBastar Craton, Mainpur field
DS200912-0087
2009
Burgess, R.Burgess, R., Cartigny, P., Harrison, D., Hobson, E., Harris, J.Volatile composition of Micro inclusions in diamonds from the PAnd a kimberlite, Canada: implications for chemical and isotopic heterogeneity in the mantle.Geochimica et Cosmochimica Acta, Vol. 73, 6, pp. 1779-1794.Canada, Northwest TerritoriesDeposit - Panda
DS200912-0422
2009
Burgess, R.Laiginhas, F., Pearson, D.G., Phillips, D., Burgess, R., Harris, J.W.Re Os and 40Ar 39Ar isotope measurements of inclusions in alluvial diamonds from the Ural Mountains: constraints on diamond genesis and eruption ages.Lithos, in press availableRussia, UralsGeochronology
DS201012-0133
2010
Burgess, R.Cuthbert, S., Qas-Cohen, A., Ballentine, C., Burgess, R., Droop, G.Norwegian garnet websterites: analogues for mantle metasomatism?Goldschmidt 2010 abstracts, abstractEurope, NorwayMetasomatism
DS201012-0430
2010
Burgess, R.Lehman, B., Burgess, R., Frei, D., Belyatsky, B., Mainkar, D., Chalapthi Rao, N.V., Heaman, L.M.Diamondiferous kimberlites in central India synchronous with Deccan flood basalts.Earth and Planetary Science Letters, Vol. 290, 1-2, Feb. 15, pp. 142-149.IndiaMineral chemistry
DS201012-0431
2010
Burgess, R.Lehmann, B., Burgess, R., Frei, D., Belyatsky, B., Mainkar, D., Chalapthi Rao, N.V., Heaman, L.M.Diamondiferous kimberlites in central India synchronous with Deccan flood basalts.International Dyke Conference Held Feb. 6, India, 1p. AbstractIndiaDharwar and Bundelkhand cratons
DS201012-0522
2009
Burgess, R.Murphy, D.T., Brandon, A.D., Debaille, V., Burgess, R., Ballentine, C.In search of a hidden long term isolated sub-chondritic 142 Nd 144Nd reservoir in the deep mantle: implications for the Nd isotope systematics of the Earth.Geochimica et Cosmochimica Acta, Vol. 74, 2, pp. 738-750.MantleGeochronology
DS201112-0832
2011
Burgess, R.Pujol, M., Marty, B., Burgess, R.Chondritic like xenon trapped in Archean rocks: a possible signature of the ancient atmosphere.Earth and Planetary Science Letters, Vol. 308, 3-4, pp. 298-306.MantleGeochronology
DS201112-0837
2011
Burgess, R.Quas-Cohen, A., Cuthbert, S., Droop, G., Ballentine, C.J., Burgess, R.Diamond facies fluid flow during subduction: evidence and consequence.Goldschmidt Conference 2011, abstract p.1683.Europe, NorwayWestern Gneiss region
DS201112-1018
2011
Burgess, R.Sumino, H., Dobrzhinetskaya, I.F., Burgess, R., Kagi, H.Deep mantle derived noble gases in metamorphic diamonds from the Kokchetav massif, Kazakhstan.Earth and Planetary Science Letters, Vol. 307, 3-4, pp. 439-449.Russia, KazakhstanMicrodiamonds - SCLM, metasomatism, subduction
DS201312-0581
2013
Burgess, R.Marty, B., Zimmermann, L., Pujol, M., Burgess, R., Philippot, P.Nitrogen isotopic composition and density of the Archean atmosphere.Science, Vol. 342, 6154, pp. 101-104.MantleVolatiles
DS201604-0598
2016
Burgess, R.Chalapathi Rao, N.V., Atiullah, Burgess, R., Nanda, P., Choudhary, A.K., Sahoo, S., Lehmann, B., Chahong, N.Petrology, 40Ar/39Ar age, Sr-Nd isotope systematics, and geodynamic significance of an ultrapotassic ( lamproitic) dyke with affinities to kamafugite from the easternmost margin of the Bastar Craton, India.Mineralogy and Petrology, in press available, 25p.IndiaDeposit - Sakri Nuapada

Abstract: We report the mineralogy, bulk-rock geochemistry, 40Ar/39Ar (whole-rock) age and radiogenic (Sr and Nd) isotope composition of an ultrapotassic dyke from Sakri (Nuapada lamproite field) located at the tectonic contact between the easternmost margin of the Bastar craton and Eastern Ghats Mobile Belt, India. The Sakri dyke has a mineralogy which strongly resembles a lamproite sensu stricto (viz.,Ti-rich phlogopite, Na-poor diopside, Fe-rich sanidine, ulvospinel trend and Sr-rich apatite). However, its bulk-rock major element geochemical characteristics (viz., extreme silica-undersaturated nature) resemble sensu lato kamafugite from Toro Ankole, Uganda, East African Rift, and Alto Paranaiba Province, Brazil. The Sakri dyke also displays certain compositional peculiarities (viz., high degree of evolution of mica composition from phlogopite to biotite, elevated titanium and aluminum in clinopyroxene and significantly lower bulk Mg#) when compared to the ultrapotassic rocks from various Indian cratons. 40Ar/39Ar dating gave a plateau age of 1045?±?9 Ma which is broadly similar to that of other Mesoproterozoic (i) lamproites from the Bastar and Bundelkhand cratons, and (ii) kimberlites from the Eastern Dharwar craton. Initial bulk-rock Sr (0.705865-0.709024) and Nd (0.511063-0.511154) isotopic ratios reveal involvement of an ‘enriched’ source region with long-term incompatible element enrichment and a depleted mantle (TDM) Nd model age of 2.56 Ga straddling the Archaean-Proterozoic chronostratigraphic boundary. The bulk-rock incompatible trace element ratios (Ta/Yb, Th/Yb, Rb/Ba and Ce/Y) of the Sakri ultrapotassic dyke negate any significant influence of crustal contamination. Small-degree melting (1 to 1.5 %) of a mixed garnet-facies and spinel-facies phlogopite lherzolite can account for its observed REE concentrations. Whereas the emplacement of the Sakri ultrapotassic dyke is related to the amalgamation of the supercontinent of Rodinia, its overlapping geochemical characteristics of lamproite and kamafugite (also displayed by two other lamproites of the Nuapada field at Amlidadar and Parkom) are linked to the emplacement in a unique geological setting at the craton-mobile belt contact and hence of geodynamic significance.
DS201808-1724
2018
Burgess, R.Avice, G., Marty, B., Burgess, R., Hofmann, A., Philippot, P., Zahnle, K., Zakharov, D.Evolution of atmospheric xenon and other noble gases inferred from Archean to Paleoproterozoic rocks.Geochimica et Cosmochimica Acta, Vol. 232, pp. 82-100.Mantlegeochemistry

Abstract: We have analyzed ancient atmospheric gases trapped in fluid inclusions contained in minerals of Archean (3.3?Ga) to Paleozoic (404?Ma) rocks in an attempt to document the evolution of the elemental composition and isotopic signature of the atmosphere with time. Doing so, we aimed at understanding how physical and chemical processes acted over geological time to shape the modern atmosphere. Modern atmospheric xenon is enriched in heavy isotopes by 30-40‰ u?1 relative to Solar or Chondritic xenon. Previous studies demonstrated that, 3.3?Ga ago, atmospheric xenon was isotopically fractionated (enriched in the light isotopes) relative to the modern atmosphere, by 12.9?±?1.2 (1?) ‰ u?1, whereas krypton was isotopically identical to modern atmospheric Kr. Details about the specific and progressive isotopic fractionation of Xe during the Archean, originally proposed by Pujol et al. (2011), are now well established by this work. Xe isotope fractionation has evolved from 21‰ u?1 at 3.5?Ga to 12.9‰ u?1 at 3.3?Ga. The current dataset provides some evidence for stabilization of the Xe fractionation between 3.3 and 2.7?Ga. However, further studies will be needed to confirm this observation. After 2.7?Ga, the composition kept evolving and reach the modern-like atmospheric Xe composition at around 2.1?Ga ago. Xenon may be the second atmospheric element, after sulfur, to show a secular isotope evolution during the Archean that ended shortly after the Archean-Proterozoic transition. Fractionation of xenon indicates that xenon escaped from Earth, probably as an ion, and that Xe escape stopped when the atmosphere became oxygen-rich. We speculate that the Xe escape was enabled by a vigorous hydrogen escape on the early anoxic Earth. Organic hazes, scavenging isotopically heavy Xe, could also have played a role in the evolution of atmospheric Xe. For 3.3?Ga-old samples, Ar-N2 correlations are consistent with a partial pressure of nitrogen (pN2) in the Archean atmosphere similar to, or lower than, the modern one, thus requiring other processes than a high pN2 to keep the Earth's surface warm despite a fainter Sun. The nitrogen isotope composition of the atmosphere at 3.3?Ga was already modern-like, attesting to inefficient nitrogen escape to space since that time.
DS201810-2299
2018
Burgess, R.Broadley, M.W., Barry, P.H., Ballentine, C.J., Taylor, L.A., Burgess, R.End-Permian extinction amplified by plume-induced release of recycled lithospheric volatiles.Nature Geoscience, 10.1038/s41561-018-0215-4 pp. 682-687.Russia, Siberiasubduction

Abstract: Magmatic volatile release to the atmosphere can lead to climatic changes and substantial environmental degradation including the production of acid rain, ocean acidification and ozone depletion, potentially resulting in the collapse of the biosphere. The largest recorded mass extinction in Earth’s history occurred at the end of the Permian, coinciding with the emplacement of the Siberian large igneous province, suggesting that large-scale magmatism is a key driver of global environmental change. However, the source and nature of volatiles in the Siberian large igneous province remain contentious. Here we present halogen compositions of sub-continental lithospheric mantle xenoliths emplaced before and after the eruption of the Siberian flood basalts. We show that the Siberian lithosphere is massively enriched in halogens from the infiltration of subducted seawater-derived volatiles and that a considerable amount (up to 70%) of lithospheric halogens are assimilated into the plume and released to the atmosphere during emplacement. Plume-lithosphere interaction is therefore a key process controlling the volatile content of large igneous provinces and thus the extent of environmental crises, leading to mass extinctions during their emplacement.
DS201904-0752
2019
Burgess, R.Kobayashi, M., Sumino, H., Burgess, R., Nakai, S., Iizuka, T., Nagao, J. Kagi, H., Nakamura, M., Takahashi, E., Kogiso, T., Ballentine, C.J.Halogen heterogeneity in the lithosphere and evolution of mantle halogen abundances inferred from intraplate mantle xenoliths. Kilbourne HoleGeochemistry, Geophysics, Geosystems, Vol. 20, 2, pp. 952-973.United States, New Mexicoxenoliths

Abstract: Elemental and isotopic compositions of volatile species such as halogens, noble gases, hydrogen, and carbon can be used to trace the evolution of these species in the Earth. Halogens are important tracers of subduction recycling of surface volatiles into the mantle: however, there is only limited understanding of halogens in the mantle. Here we provide new halogen data of mantle xenoliths from intraplate settings. The mantle xenoliths show a wide range of halogen elemental ratios, which are expected to be related to later processes after the xenoliths formed. A similar primary halogen component is present in the xenoliths sampled from different localities. This suggests that the mantle has the uniform halogen composition over a wide scale. The halogen composition in the convecting mantle is expected to have remained constant over more than 2 billion years, despite subduction of iodine?rich halogens. We used mass balance calculations to gain understanding into evolution rate of I/Cl ratio in the mantle. Calculations suggest that, in order to maintain the I/Cl ratio of the mantle over 2 Gyr, the I/Cl ratio of the subducted halogens must be no more than several times higher than the present?day mantle value.
DS202103-0389
2020
Burgess, R.Kumar, A., Talukdar, D., Chalapathi Rao, N.V., Burgess, R., Lehmann, B.Mesoproterozoic 40Ar-39Ar ages of some lamproites from the Cuddapah Basin and eastern Dharwar craton, southern India: implications for diamond provenance of the Banganapalle conglomerates, age of the Kurnool Group and Columbia tectonics.Geological Society, London, Special Publication , 10.1144/SP513- 2020-247 53p. PdfIndialamproites

Abstract: We report Mesoproterozoic 40Ar-39Ar (whole-rock) ages of lamproites from (i) the Ramadugu field (R4 dyke : 1434 ± 19 Ma and R5 dyke: 1334 ± 12 Ma) and the Krishna field (Pochampalle dyke: 1439 ± 3 Ma and Tirumalgiri dyke: 1256 ± 12 Ma) from the Eastern Dharwar Craton (EDC) and (ii) the Garledinne (1433 ± 8 Ma) and the Chelima (1373 ± 6 Ma) dykes from within the Paleo-Mesoproterozoic Cuddapah Basin, southern India. The ages reported for the Ramadugu and Tirumalgiri lamproites constitute their first radiometric dates. Ages of the Pochampalle and the Chelima lamproites from this study are broadly comparable to their previously reported 40Ar-39Ar (phlogopite) ages of c. 1500 Ma and 1418 ± 8 Ma, respectively. The ages of all these lamproites are much older than those of the (i) c. 1.1 Ga kimberlites from the Wajrakarur and Narayanpet fields of the EDC and (ii) c. 1.09 Ga lamproitic dykes at Zangamarajupalle which intrude the Cumbum Formation of the Cuddapah Basin. However, the age of the Tirumalgiri lamproite (c. 1256 Ma) is similar to that of the Ramannapeta lamproite (c. 1224 Ma) within the Krishna field. Our study provides evidence for protracted ultrapotassic (lamproitic) magmatism from c. 1.43 to 1.1 Ga over a widespread area (c. 2500 km2) in and around the Cuddapah Basin and the EDC. Implications of the obtained new ages for the diamond provenance of the Banganapalle Conglomerates, the age of the Kurnool Group and for the timing of break-up of the Paleo-Mesoproterozoic supercontinent of Columbia/Nuna are explored.
DS202202-0203
2022
Burgess, R.Kumar, A., Talukdar, D., Chalapathi Rao, N.V., Burgess, R., Lehmann, B.Mesoproterozoic 40Ar-39Ar ages of some lamproites from the Cuddapah basin and eastern Dharwar craton, southern India: implications for diamond provenance of the Banganapalle conglomerates, age of the Kurnool Group and Columbia tectonics.Geological Society of London Special Publication 513, pp. 157-178.Indialamproites

Abstract: We report Mesoproterozoic 40Ar-39Ar (whole-rock) ages of lamproites from (i) the Ramadugu field (R4 dyke : 1434 ± 19 Ma and R5 dyke: 1334 ± 12 Ma) and the Krishna field (Pochampalle dyke: 1439 ± 3 Ma and Tirumalgiri dyke: 1256 ± 12 Ma) from the Eastern Dharwar Craton (EDC) and (ii) the Garledinne (1433 ± 8 Ma) and the Chelima (1373 ± 6 Ma) dykes from within the Paleo-Mesoproterozoic Cuddapah Basin, southern India. The ages reported for the Ramadugu and Tirumalgiri lamproites constitute their first radiometric dates. Ages of the Pochampalle and the Chelima lamproites from this study are broadly comparable to their previously reported 40Ar-39Ar (phlogopite) ages of c. 1500 Ma and 1418 ± 8 Ma, respectively. The ages of all these lamproites are much older than those of the (i) c. 1.1 Ga kimberlites from the Wajrakarur and Narayanpet fields of the EDC and (ii) c. 1.09 Ga lamproitic dykes at Zangamarajupalle which intrude the Cumbum Formation of the Cuddapah Basin. However, the age of the Tirumalgiri lamproite (c. 1256 Ma) is similar to that of the Ramannapeta lamproite (c. 1224 Ma) within the Krishna field. Our study provides evidence for protracted ultrapotassic (lamproitic) magmatism from c. 1.43 to 1.1 Ga over a widespread area (c. 2500 km2) in and around the Cuddapah Basin and the EDC. Implications of the obtained new ages for the diamond provenance of the Banganapalle Conglomerates, the age of the Kurnool Group and for the timing of break-up of the Paleo-Mesoproterozoic supercontinent of Columbia/Nuna are explored.
DS201412-0908
2014
Burgess, S.D.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
DS1995-0236
1995
Burgess, S.R.Burgess, S.R., et al.Oxygen isotope compositions of metasomatised mantle peridotite xenolithsTerra Nova, Abstract Vol., p. 334.MantleXenoliths
DS1995-0237
1995
Burgess, S.R.Burgess, S.R., Graham, C.M., Valley, J.W., Harte, B.Oxygen isotope composition of metasomatised mantle peridotite xenoliths -laser fluorination/microprobeProceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 83-85.South AfricaGeochronology, Deposit -Jagersfontein
DS1995-0238
1995
Burgess, S.R.Burgess, S.R., Harte, B., Hops, J.J.Irregular compositional zoning in garnets from metasomatised high temp.peridotites JagersfonteinProceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 86-88.South AfricaPetrography -garnets, Deposit -Jagersfontein
DS1995-0239
1995
Burgess, S.R.Burgess, S.R., Turner, G.Halogen composition of mantle fluids in diamondProceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 89-91.MantleGeochronology
DS1995-0240
1995
Burgess, S.R.Burgess, S.R., Turner, G., Mattey, D.P.Helium, argon and carbon isotope constraints on the formation of cubic and polycrystalline diamonds.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 92-94.GlobalGeochronology -noble gas, cubic diamonds, Deposit -Jwaneng, Orapa
DS1998-0189
1998
Burgess, S.R.Burgess, S.R., Harte, B.Tracing lithosphere evolution through the analysis of heterogeneous G9 G10garnets in peridotite xenoliths.7th International Kimberlite Conference Abstract, pp. 122-126South AfricaGeochemistry - garnet composition, Deposit - Jagersfontein
DS2003-0625
2003
Burgess, S.R.Ivanic, T.J., Hartem B., Burgess, S.R., Gurney, J.J.Factors in the formation of sinuous and humped Ree patterns in garnets from mantle8ikc, Www.venuewest.com/8ikc/program.htm, Session 4, POSTER abstractMantleMantle geochemistry
DS200412-0246
2004
Burgess, S.R.Burgess, S.R., Harte, B.Tracing lithospheric evolution through the analysis of heterogeneous G9 G10 garnets in peridotite xenoliths II. REE chemistry.Journal of Petrology, Vol. 45, 3, pp. 609-633.MantleGeochemistry, Deposit - Jagersfontein, metasomatic melt
DS200412-0676
2004
Burghammer, M.Glinnemann, J., Burghammer, M., Winkler, B., Nasdala, L., Harris, J.W.Single crystal graphite inclusions in natural diamonds.Lithos, ABSTRACTS only, Vol. 73, p. S44. abstractCanada, Northwest TerritoriesDiamond morphology, Panda, Ekati
DS201511-1824
2015
Burgisser, A.Bergantz, G.W., Schleicher, J.M., Burgisser, A.Open system dynamics and mixing in magma mushes.Nature Geoscience, Vol. 8, 10, pp. 793-796.MantleMagmatism

Abstract: Magma dominantly exists in a slowly cooling crystal-rich or mushy state1, 2, 3. Yet, observations of complexly zoned crystals4, some formed in just one to ten years5, 6, 7, 8, 9, as well as time-transgressive crystal fabrics10 imply that magmas mix and transition rapidly from a locked crystal mush to a mobile and eruptable fluid5, 6. Here we use a discrete-element numerical model that resolves crystal-scale granular interactions and fluid flow, to simulate the open-system dynamics of a magma mush. We find that when new magma is injected into a reservoir from below, the existing magma responds as a viscoplastic material: fault-like surfaces form around the edges of the new injection creating a central mixing bowl of magma that can be unlocked and become fluidized, allowing for complex mixing. We identify three distinct dynamic regimes that depend on the rate of magma injection. If the magma injection rate is slow, the intruded magma penetrates and spreads by porous media flow through the crystal mush. With increasing velocity, the intruded magma creates a stable cavity of fluidized magma that is isolated from the rest of the reservoir. At higher velocities still, the entire mixing bowl becomes fluidized. Circulation within the mixing bowl entrains crystals from the walls, bringing together crystals from different parts of the reservoir that may have experienced different physiochemical environments and leaving little melt unmixed. We conclude that both granular and fluid dynamics, when considered simultaneously, can explain observations of complex crystal fabrics and zoning observed in many magmatic systems.
DS2003-1329
2003
Burgmann, R.Steblov, G.M., Kogan, M.G., King, R.W., Scholz, C.H., Burgmann, R., FrolovImprint of the North American plate in Siberia revealed by GPSGeophysical Research Letters, Vol. 30, 18, 1924 DOI.1029/2003GLO17805Russia, Siberia, Northwest Territories, EurasiaGeophysics - seismics
DS200412-1918
2003
Burgmann, R.Steblov, G.M., Kogan, M.G., King, R.W., Scholz, C.H., Burgmann, R., Frolov, D.I.Imprint of the North American plate in Siberia revealed by GPS.Geophysical Research Letters, Vol. 30, 18, 1924 DOI.1029/2003 GLO17805Russia, Siberia, Canada, Northwest TerritoriesGeophysics - seismics
DS200812-0154
2008
Burgmann, R.Burgmann, R., Dresen, G.Rheology of the Lower crust and Upper mantle: evidence from rock mechanics, geodesy and field observations.Annual Review of Earth and Planetary Sciences, Vol. 36, May, pp. 531-567.MantleRheology
DS200912-0032
2008
Burgmann, R.Banerjee, P., Burgmann, R., Nagarajan, B., Apel, E.Intraplate deformation of the Indian subcontinent.Geophysical Research Letters, Vol. 35, 18, Sept. 28, L18301IndiaSubduction
DS201112-0040
2011
Burgmann, R.Audet, P., Burgmann, R.Dominant role of tectonic inheritance in supercontinent cycles.Nature Geoscience, Vol. 4, pp. 184-187.MantleGeophysics - seismics
DS201412-0027
2014
Burgmann, R.Audet, P., Burgmann, R.Possible control of subduction zone slow-earthquake periodicity by silica enrichment.Nature, Vol. 510, pp. 389-392.MantleSubduction
DS1950-0324
1957
Burgoon, J.R.Burgoon, J.R.Diamond Mining in Arkansaw. #2Gems And Gemology, Vol. 20, PP. 355-362.United States, Gulf Coast, Arkansas, PennsylvaniaMining, Sampling
DS202202-0206
2022
Burgos, G.Montagner, J-P., Burgos, G., Capdeville, Y., Beucler, E., Mocquet, A.The mantle transition zone dynamics as revealed through seismic anisotropy.Tectonophysics, Vol. 821, 229133, 11p. PdfMantlegeophysics - seismics

Abstract: The mantle transition zone (MTZ) of the Earth lies between 410 and ?1000 km in depth and has a key role in mantle convection processes. In particular, the discontinuity at 660 km and its associated endothermic mineralogical transformation can slow or inhibit the passage of matter between the upper and lower mantle. The MTZ thus acts as a boundary layer within the mantle. The depth variations of radial and azimuthal seismic anisotropies enable the detection of boundary layers within the mantle. However, the 3D imaging is difficult due to the lack of sensitivity of surface waves of fundamental modes, and the poor global coverage of this depth range by body-wave data. We present a new 3D general anisotropy model (both radial and azimuthal anisotropies) of the mantle down to 1200 km in depth using surface-wave overtone datasets. We find that there is little seismic anisotropy in most of the MTZ, except below subduction zones around the Pacific Ocean and, more surprisingly, in a large area beneath eastern Eurasia where the Pacific subducting plate is stagnant. Seismic anisotropy is usually associated with intense deformation processes but also possibly to water transportation or to fine layering. This significant anisotropy in this part of MTZ might reveal a large water ‘reservoir’ associated with hydrous minerals or a strong stratification. It reflects a complex history beneath central Asia, where the Tethys, Izanagi and Pacific plates appear to have strongly interacted during the last 100 My, having subducted in orthogonal directions under the Asian continent, with the Tethys plate descending into the lower mantle, and the Izanagi plate remaining stagnant in the MTZ. The Asian continent is the only region in the world where subducting slabs originating from different plates can interact. This unique slab distribution might explain why some plates descend while others remain in the lower transition zone.
DS202101-0022
2020
Burianek, D.Kropac, K., Dolnicek, Z., Uher, P., Burianek, D., Safai, A., Urubek, T.Zirconian-niobian titanite and associated Zr-, Nb-, REE-rich accessory minerals: products of hydrothermal overprint of leucocratic teschenites ( Sileasian Unit, outer western Carpathians, Czech Republic).Geologica Carpathica ** Eng, Vol. 71, 4, pp. 343-360. pdfEurope, Czech Republicalkaline rocks

Abstract: Sills of hydrothermally altered alkaline magmatic rock (teschenite) of Lower Cretaceous age at the ?er?ák and ?epišt? sites in the Silesian Unit (Flysch Belt of the Outer Western Carpathians, Czech Republic) host leucocratic dykes and nests which contain accessory minerals enriched in Zr, Nb and REE: Zr-, Nb-rich titanite, zircon, gittinsite, pyrochlore, monazite, REE-rich apatite, epidote, and vesuvianite. Titanite forms wedge-shaped crystals or irregular aggregates enclosed in the analcime groundmass or overgrowths on Zr-rich ferropargasite and taramite or Zr-rich aegirine-augite to aegirine. Titanite crystals show oscillatory or irregular patchy to sector zoning and contain up to 17.7 wt. % ZrO2 and 19.6 wt. % Nb2O5, and ?1.1 wt. % REE2O3. High-field-strength elements (HFSE) are incorporated into the structure of the studied titanite predominantly by substitutions: (i) [6]Ti4+???[6]Zr4+; (ii) [6]Ti4+?+?[6]Al3+???[6]Zr4+?+?[6]Fe3+; and (iii) [6]2Ti4+???[6]Nb5+?+?[6](Al, Fe)3+. Magmatic fractional crystallization, high-temperature hydrothermal autometasomatic overprint and low-temperature hydrothermal alterations resulted in the formation of the HFSE-rich mineral assemblages within the leucocratic teschenites. Autometamorphic processes caused by high-temperature hypersaline aqueous solutions (salinity ~50 wt. %, ~390-510 °C), which were released from the HFSE-enriched residual melt, played a major role in the crystallization of Zr-, Nb-, and REE-rich minerals. The mobilization of HFSE could have occurred either by their sequestration into a fluid phase exsolved from the crystallizing melt or by superimposed alteration processes. The distinctive positive Eu anomaly (EuCN/Eu*?=?1.85) of leucocratic dykes infers possible mixing of Eu2+-bearing magmatic fluids with more oxidized fluids.
DS1993-0778
1993
BurianykKanasewich, E.R., Burianyk, Milkereit, White, RossThe central Alberta transect 992 acquisition program: preliminary results and progress report.Lithoprobe Report, No. 31, pp. 1-8.AlbertaGeophysics - seismics
DS1995-0913
1995
BurianykKanesewich, E.R., Burianyk, Dubuc, Lemieux, KalantzisThree dimensional seismic reflection studies of the Alberta basementCanadian Journal of Exploration Geophysics, Vol. 31, No. 1-2, pp. 1-10.AlbertaGeophysics - seismics, Tectonics
DS1995-1612
1995
BurianykRoss, G., Milkereit, Eaton, White, Kanasewich, BurianykPaleoproterozoic collisional orogen beneath Western Canada sedimentary basin imaged by lithoprobe crustal..#2Geology, Vol 25, No. 3, Mar. pp. 195-9.Alberta, Western CanadaTectonics - orogeny
DS2002-0298
2002
Burianyk, M.Clowes, R.M., Burianyk, M., Gorman, A., KanasewichCrustal velocity structure from Sarex, the southern Alberta Refraction ExperimentCanadian Journal of Earth Science, Vol.39,3,Mar.pp.351-73., Vol.39,3,Mar.pp.351-73.Alberta, MontanaGeophysics - seismics, Loverna Domain, Hearne Province, Vulcan Structure
DS2002-0299
2002
Burianyk, M.Clowes, R.M., Burianyk, M., Gorman, A., KanasewichCrustal velocity structure from Sarex, the southern Alberta Refraction ExperimentCanadian Journal of Earth Science, Vol.39,3,Mar.pp.351-73., Vol.39,3,Mar.pp.351-73.Alberta, MontanaGeophysics - seismics, Loverna Domain, Hearne Province, Vulcan Structure
DS1997-0146
1997
Burianyk, M.J.A.Burianyk, M.J.A., Kanasewich, E.R., Udey, N.Broadside wide angle seismic studies and three dimensional structure of the crust in the southeast CordilleraCanadian Journal of Earth Sciences, Vol. 34, No. 8, August pp. 1156-66.Cordillera, British Columbia, AlbertaGeophysics - seismics, Structure
DS1996-0196
1996
Burinayk, M.Burinayk, M., Kanasewich, E.Measuring velocities from an expanding spreading profile (ESP) seismic experiment ....Ross, G.M. Lithoprobe Alberta, No. 51, pp. 39-49.AlbertaGeophysics - seismics, Basement transect
DS1950-0325
1957
Buriv, A.P.Buriv, A.P., Sobolev, V.S.Diamonds of SiberiaMoscow: Gosgeoltekhizdat., 158P.RussiaKimberlite
DS1860-0178
1872
Burkart, H.J.Burkart, H.J.Der Diamant, Sein Verkommen und Seine GenesisAusland., Vol. 44, PP. 1188-1195; PP. 1205-1211; PP. 1237-1243; Vol. 4Europe, Spain, Ireland, China, Mexico, United States, North CarolinaDiamond Genesis
DS200812-0155
2007
Burke, A.Burke, A.Recovery in naturally dynamic environments: a case study from the Sperrgebiet, southern African arid succulent Karoo.Environmental Management, Vol. 40, 4, pp. 635-648.Africa, NamibiaDeposit - Sperrgebiet
DS1994-1781
1994
Burke, E.A.J.Ting, W., Burke, E.A.J., Rankin, A.H., Woolley, A.R.The characterization and petrogenetic significance of CO2, H2O and CH4fluid inclusions in apatite SukuluEuropean Journal of Mineralogy, No. 6, pp. 787-804.UgandaCarbonatite, Deposit -Sukulu
DS1995-1059
1995
Burke, E.A.J.Larsen, R., Burke, E.A.J., Dobrzhinetskaya, L.F., et al.N2 CO2 CH2 H2O metamorphic fluids in microdiamond bearing lithologies From the western gneiss region.Ngu (norges Geol. Undersoklse, Bulletin., No. 427, pp. 41-43.NorwayDiamonds
DS1998-0830
1998
Burke, E.A.J.Larsen, R.B., Eide, E.A., Burke, E.A.J.Evolution of metamorphic volatiles during exhumation of microDiamond bearing granulites Western Gneiss Region.Contributions to Mineralogy and Petrology, Vol. 133, No. 1-2, pp. 106-27.NorwayMicrodiamond, metamorphism
DS1997-0147
1997
Burke, G.Burke, G.Policies for small scale mining: the need for integrationJournal of Mineral Policy, Vol. 12, No. 3, pp. 11-14GlobalMining - small scale, Legal - policy
DS1970-0641
1973
Burke, K.Burke, K., Dewey, J.F.Plume generated triple junctions: key indicators to applying plate tectonics to old rocks.Journal of Geology, Vol. 81, pp. 405-33.GlobalTectonics, Geodynamics - Hotspots
DS1970-0642
1973
Burke, K.Burke, K., Whiteman, A.J.Uplift, Rifting and the Break Up of AfricaAcademic Press, 784P. PP. 735-755.AfricaGeotectonics
DS1975-0474
1977
Burke, K.Burke, K.Aulacogens and Continental BreakupAnnual Review of Earth and Planetary Science, Vol. 5, PP. 371-396.MichiganMid-continent
DS1985-0097
1985
Burke, K.Burke, K., Kidd, W.S.F., Kusky, T.Is the Ventersdorp Rift System of Southern Africa Related To a Continental Collision between the Kaapvaal and Zimbabwe Cratons at 2.64 Ga Ago?Tectonophysics, Vol. 115, PP. 1-24.South Africa, ZimbabweGeotectonics
DS1985-0098
1985
Burke, K.Burke, K., Kidd, W.S.F., Kusky, T.M.The Pongola Structure of Southeastern Africa: the World's Oldest Preserved Rift.Journal of GEODYNAMICS, Vol. 2, PP. 35-49.South Africa, SwazilandTectonics, Geochronology, Stratigraphy
DS1989-0041
1989
Burke, K.Ashwal, L.D., Burke, K.African lithospheric structure, volcanism and topographyEarth and Planetary Science Letters, Vol. 96, pp. 8-14South AfricaCraton -rifting, Mantle lithosphere
DS1992-0190
1992
Burke, K.Burke, K.Continental rifts and mineral resourcesGeological Society of America (GSA) Abstracts with programs, 1992 Annual, Vol. 24, No. 7, abstract p. A21MantleRifting, Tectonics
DS1993-1425
1993
Burke, K.Sengor, A.M., Burke, K., Natalin, B.A.Asia: a continent made and assembled during the PhanerozoicShort Course NOtes for Geological Society of America Meeting, Boston, 261p.AsiaCraton, Continent evolution
DS1993-1831
1993
Burke, K.Zoback, M.L., Burke, K.Lithospheric stress patterns: a global viewEos, Vol. 74, No. 52, December 28, p. 609, 615MantleCrust, Tectonics
DS1993-1832
1993
Burke, K.Zoback, M.L., Burke, K.Lithospheric stress patterns: a global viewEos, Vol. 74, No. 52, December 28, p. 609, 615, 618.MantleGeophysics, Tectonics
DS1996-0197
1996
Burke, K.Burke, K.The African plate. Alex du Toit Memorial LectureSouth African Journal of Geology, Vol. 99, No. 4, pp. 339-409AfricaReview - tectonics, TectonisM.
DS1996-0198
1996
Burke, K.Burke, K.The African plate. Alex du Toit Memorial lectureSouth African Journal of Geology, Vol. 99, No. 4, pp. 339-409.AfricaTectonics, Review - continental tectonisM.
DS1998-0190
1998
Burke, K.Burke, K.Do three or more rifts that meet indicate the location or the former location of an underlying mantle plume?Geological Society of America (GSA) Annual Meeting, abstract. only, p.A344.Tanzania, East AfricaTectonics, Mantle plumes
DS2003-0188
2003
Burke, K.Burke, K., Ashwal, L.D., Webb, S.J.New ways to map old sutures using deformed alkaline rocks and carbonatitesGeology, Vol. 31, No. 5, pp. 391-394Africaalkaline igneous rocks, Carbonatite - mapping Proterozoic suture zones
DS2003-0189
2003
Burke, K.Burke, K., Ashwal, L.D., Webb, S.J.New way to map old sutures using deformed alkaline rocks and carbonatitesGeology, Vol. 31, 5, May pp. 391-4.AfricaCollision, Pan African Orogeny, rifting
DS2003-0190
2003
Burke, K.Burke, K., Ashwal, L.D., Webb, S.J.New way to map old sutures using deformed alkalic rocks and carbonatitesGeology, Vol. 31, 5, May pp. 391-394.AfricaPan-African orogeny
DS2003-0191
2003
Burke, K.Burke, K., Ashwal, L.D., Webb, S.J.New way to map old sutures using deformed alkaline rocks and carbonatitesGeology, Vol. 31, 5, pp. 391-4.Africa, MalawiCarbonatite - DARC, Magmatism
DS200412-0247
2003
Burke, K.Burke, K., Ashwal, L.D., Webb, S.J.New way to map old sutures using deformed alkalic rocks and carbonatites.Geology, Vol. 31, 5, May pp. 391-394.Africa, MalawiTectonics - Proterozoic, rifting, Pan-African Orogeny
DS200512-0122
2004
Burke, K.Burke, K., Torsvik, T.H.Derivation of large igneous provinces of the past 200 million years from long term heterogeneities in the deep mantle.Earth and Planetary Science Letters, Vol. 227, 3-4, Nov. 15, pp. 531-538.MantlePlume, paleomagnetics, seismic tomography, core-mantle
DS200612-0197
2006
Burke, K.Burke, K., Khan, S.Geoinformatic approach to global nepheline syenite and carbonatite distribution: testing a Wilson cycle model.Geosphere, Vol. 2, 1, pp. 53-60.Russia, Kola PeninsulaAlkaline rocks, carbonatite, deformation
DS200612-0810
2006
Burke, K.Li, A., Burke, K.Upper mantle structure of southern Africa from Rayleigh wave tomography.Journal of Geophysical Research, Vol. 111, B 10, B 10303.Africa, South Africa, BotswanaGeophysics - seismics
DS200712-0123
2007
Burke, K.Burke, K., Roberts, D., Ashwal, L.D.Alkaline rocks and carbonatites of northwestern Russia and northern Norway: linked Wilson cycle records over two billion years.Tectonics, Vol. 26, 4, TC4015.RussiaCarbonatite
DS200712-0124
2007
Burke, K.Burke, K., Roberts, D., Ashwal, L.D.Alkaline rocks and carbonatites of northwestern Russia and northern Norway: linked Wilson cycle records extending over two billion years.Tectonics, Vol. 26, pp. TC4015 10p.Europe, Russia, NorwayCarbonatite
DS200712-0658
2006
Burke, K.Lytwyn, J., Burke, K., Culver, S.The nature and location of the suture zone in the Rokelide orogen, Sierra Leone: geochemical evidence.Journal of African Earth Sciences, Vol. 46, 5, Dec. pp. 439-454.Africa, Sierra LeoneGeochemistry - tectonics
DS200712-1092
2006
Burke, K.Torsvik, T.H., Smethurst, M.A., Burke, K., Steinberger, B.Large igneous provinces generated from the margins of the large low velocity provinces in the deep mantle.Geophysical Journal International, Vol. 167, 3, Dec. 1, pp. 1447-1460..MantleGeophysics - seismics
DS200812-0156
2007
Burke, K.Burke, K.Supercontinent: ten billion years in the Life of Our Planet. ( T. Nield author).Science, Vol. 318 No. 5855 Nov. 30, p. 1385.MantleBook review
DS200812-0157
2008
Burke, K.Burke, K., Gunnell, Y.The African erosion surface: a continental scale synthesis of geomorphology, tectonics and environmental change over the past 180 million years.Geological Society of America Memoir, Memoir 201, gsajournals.orgAfricaBook - geomorphology
DS200812-0158
2008
Burke, K.Burke, K., Gunnell, Y.The African erosion surface: a continental scale synthesis of geomorphology, tectonics and environmental change over the past 180 million years.Geological Society of America, Memoir 201, 72p. $ 45.00AfricaBook - geomorphology
DS200812-0159
2007
Burke, K.Burke, K., Steinberger, B., Torsvik, T.H., Smethurst, M.A.Plume generation zones at the margins of large low shear velocity provinces on the core-mantle boundary.Earth and Planetary Science Letters, Vol. 265, 1-2, pp. 49-60.MantleLPP, mantle plumes, hotspots
DS200812-1182
2008
Burke, K.Torsvik, T.H., Smethurst, M.A., Burke, K., Steinberger, B.Long term stability in deep mantle structure: evidence from the 300 Ma Skagerrak centered large igneous province SCLIP.Earth and Planetary Science Letters, Vol. 267, 3-4, pp. 444-452.EuropeMagmatism
DS200912-0088
2008
Burke, K.Burke, K., Khan, S.D., Mart, R.W.Grenville Province and Monteregian carbonatite and nepheline syenite distribution related to rifting, collision and plume passage.Geology, Vol. 36, 12, Dec. pp. 983-986.Canada, QuebecCarbonatite
DS200912-0769
2008
Burke, K.Torsvik, T.H., Steinberger, B., Cocks, L.R.M., Burke, K.Longitude: linking Earth's ancient surface to its deep interior.Earth and Planetary Science Letters, Vol. 276, 3-4, Dec. pp. 273-382.MantlePalemagnetism, core-mantle boundary
DS201012-0792
2010
Burke, K.Torsvik, T.H., Burke, K., Steinberger, B., Webb, S.J., Ashwal, L.D.Diamonds sampled by plumes from the core-mantle boundary.Nature, Vol. 466, July 15, pp. 352-356.MantleDiamond genesis, emplacement
DS201112-0128
2011
Burke, K.Burke, K.Plate tectonics, the Wilson Cycle, and mantle plumes: geodynamics from the top.Annual Review of Earth and Planetary Sciences, Vol. 39, pp. 1-29.MantleOverview - plumes
DS1993-0190
1993
Burke, K.C.Burke, K.C., Lytwyn, J.Origin of the rift under the Amazon Basin as a result of continental collision during Pan-African time.International Geology Review, Vol. 35, No. 9, pp. 881-897.BrazilTectonics
DS1998-0284
1998
Burke, K.C.Crowley, T.J., Burke, K.C.Tectonic boundary conditions for climate reconstructionsOxford University of Press, 288p. $ 75.00GlobalBook - ad, Global change, climate studies
DS1950-0460
1959
Burke, L.J.Burke, L.J.A Short Account of the Discovery of the Major Diamond Deposits.Sierra Leone Studies, N.S. No. 12, PP. 316-328.Sierra Leone, West Africa, Central African Republic, French Equatorial Africa, GuineaHistory
DS1975-0494
1977
Burke, W.H.Denison, R.E., Burke, W.H., Otto, J.B., Heatherington, E.A.Age of Igneous and Metamorphic Activity Affecting the Ouachita Foldbelt.Arkansaw GEOL. COMM., PP. 25-40.United States, Oklahoma, ArkansasStructure, Geochronology
DS1975-0711
1978
Burke-Griffin, N.M.Burke-Griffin, N.M.Geology, Petrology and Geochemistry of Black Butte Volcanicneck, Gravelly Range, Montana.Msc. Thesis Wright State University, Montana, United States, Rocky MountainsLamproite
DS201412-0084
2014
Burkett, E.Burkett, E., Gurnis, M.Stalled slab dynamics.Lithosphere, Vol. 6, no. 1, pp. 92-97.MantlePlume
DS200612-0198
2006
Burkhard, M.Burkhard, M., Caritag, S., Helg, U., Robert Charrue, C., Soulaimani, A.Tectonics of the Anti-Atlas of Morocco.Comptes Rendus Geoscience, Vol. 338, 1-2, pp. 11-24.Africa, MoroccoTectonics
DS200612-0199
2006
Burkhard, M.Burkhard, M., Caritg, S., Helg, U., Robert-Charrue, C., Soulainmani, A.Tectonics of the Anti-Atlas of Morocco.Comptes Rendus Geoscience, Vol. 338, 1-2, pp. 11-24.Africa, MoroccoTectonics
DS201709-1967
2017
Burkhart, P.A.Burkhart, P.A., Alley, R.B., Thompson, L.G., Balog, J.D., Baukdauf, P.E., Baker, G.S.Savor the cryosphere.GSA Today, Vol. 27, pp. 4-11.Globalglaciers

Abstract: This article provides concise documentation of the ongoing retreat of glaciers, along with the implications that the ice loss presents, as well as suggestions for geoscience educators to better convey this story to both students and citizens. We present the retreat of glaciers—the loss of ice—as emblematic of the recent, rapid contraction of the cryosphere. Satellites are useful for assessing the loss of ice across regions with the passage of time. Ground-based glaciology, particularly through the study of ice cores, can record the history of environmental conditions present during the existence of a glacier. Repeat photography vividly displays the rapid retreat of glaciers that is characteristic across the planet. This loss of ice has implications to rising sea level, greater susceptibility to dryness in places where people rely upon rivers delivering melt water resources, and to the destruction of natural environmental archives that were held within the ice. Warming of the atmosphere due to rising concentrations of greenhouse gases released by the combustion of fossil fuels is causing this retreat. We highlight multimedia productions that are useful for teaching this story effectively. As geoscience educators, we attempt to present the best scholarship as accurately and eloquently as we can, to address the core challenge of conveying the magnitude of anthropogenic impacts, while also encouraging optimistic determination on the part of students, coupled to an increasingly informed citizenry. We assert that understanding human perturbation of nature, then choosing to engage in thoughtful science-based decision-making, is a wise choice. This topic comprised “Savor the Cryosphere,” a Pardee Keynote Symposium at the 2015 Annual Meeting in Baltimore, Maryland, USA, for which the GSA recorded supporting interviews and a webinar.
DS1998-0356
1998
Burki, B.Doeflinger, E., Bayer, R., Chery, J., Burki, B.The Global Position System in mountainous areas: effect of the troposhereon the vertical GPS accuracyC.r. Academy Of Science Paris, Vol. 326, pp. 319-325GlobalGPS, Mountain region
DS1970-0042
1970
Burkov, V.Burkov, V.Rare Elements in Minerals of KimberliteGeokhim. Issled. Akad. Nauk Sssr Institute Mineral. Geokhim. Kri, No. 1, PP. 16-24.RussiaBlank
DS1960-0523
1965
Burkov, V.V.Burkov, V.V., Podporina, YE. K.Rare Elements in Kimberlite RocksDoklady Academy of Science USSR, Earth Science Section., Vol. 163, No. 1-6, PP. 169-172.RussiaBlank
DS1960-0803
1967
Burkov, V.V.Burkov, V.V., Podorina, YE. K.First Dat a on Rare Earths in KimberliteDoklady Academy of Science USSR, Earth Science Section., Vol. 171, No. 1-6, PP. 215-219.RussiaBlank
DS1988-0550
1988
Burks, F.B.J.M.Popplewell, G.M., Burks, F.B.J.M.A review of the development of dense medium plant design in the diamond mining industry.Van Eck and Lurie, paper given at Third Samancor Symposium, 33p.GlobalDMS, rotary plans, jigs, Mineral processing - review
DS1970-0486
1972
Burley, A.J.Burley, A.J., Greenwood, P.G.Geophysical Surveys over Kimberlite Pipes in LesothoInstitute of Geological Sciences GEOPHYS. DIV., I.G.S. 540 1009/72, 32P.LesothoKimberlite, Geophysics
DS1981-0104
1981
Burley, A.J.Burley, A.J., Kimbell, G.S., Patrick, D.J., Turnbulletin, G.A Gravity Survey of LesothoLondon: Institute of Geological Sciences International Report, 39P.LesothoRegional Tectonics, Geophysics
DS2002-1731
2002
Burlinggame, D.Witteman, J., Bealieu, R., Burlinggame, D., Hanks, C.The contribution of BHP Billiton's Ekati diamond mine to sustainable development in Canada's north.Australian Institute of Mining and Metallurgy, No. 3/2002, pp.179-84.Northwest TerritoriesMining - environmental agreement, socioeconomic, Deposit - Ekati
DS1995-0241
1995
Burlini, L.Burlini, L., Kern, H., AshchepkovSeismic properties of continental mantle xenoliths at the garnet-spineltransition. an experimental study.Proceedings of the Sixth International Kimberlite Conference Extended Abstracts, p. 95-97.Russia, VitiM.Xenoliths, Petrology -experimental
DS1986-0801
1986
Burmeister, B.Thomson, M., Howie, R., Burmeister, B.Diamonds in AustraliaA. Mullens And Co, 47pAustraliaHistory, Production
DS1859-0111
1853
Burmeister, H.Burmeister, H.Reise Nach BrasilienBerlin: Reimer., 610P., ( DIAMOND FIELDS PP. 595-603 ). XEROXBrazilTravelogue
DS1994-0129
1994
Burmester, et al.Beck, M.E., Russell, R., Burmester, et al.A tale of two continents: tectonic contrasts between the central Andes And the N. A. Cordillera, as illustrated by their paleomagnetic signatures.Tectonics, Vol. 13, No. 1, February pp. 215-Brazil, CaliforniaTectonics, Geophysics -paleomagnetics
DS1994-0127
1994
Burmester, R.R.Beck, M.E., Burmester, R.R., Drake, R.E., Riley, P.D.A tale of two continents: some tectonic contrasts between the Central Andes and the North America Cordillera as illustrated by their paleomagneticsignaturesTectonics, Vol. 13, No. 1, February pp. 215-Cordillera, Andes, ChileTectonics, Geophysics -paleomagnetics
DS202008-1407
2020
Burmii, J.P.Kargin, A.V., Nosova, A.A., Sazonova, L.V., Peresetskaya, E.V., Golubeva, Yu.Yu., Lebedeva, N.M., Tretyachenko, V.V., Khvostikov, V.A., Burmii, J.P.Ilmenite from the Arkangelsk diamond province, Russia: composition, origin and indicator of diamondiferous kimberlites.Petrology, Vol. 28, 4, pp. 341-369. pdfRussia, Archangelilmenite

Abstract: To provide new insights into the origin and evolution of kimberlitic magmas with different diamond concentrations from the Arkhangelsk diamond province in northwestern Russia, we examined the major-and trace-element compositions of ilmenite from diamondiferous kimberlite of the Grib pipe and diamond barren kimberlites from the Kepino cluster (Stepnaya and TsNIGRI-Arkhangelskaya pipes). Ilmenite from diamond-barren kimberlites shows lower Mg, Ti, Cr, Ni and Cu concentrations with increase in both Fe 3+ and Fe 2+ and Nb, Ta, Zr, Hf, Zn and V concentrations. The main differences between kimberlites with different diamond contents are the Nb and Zr concentrations and their correlation patterns with Mg and Cr concentrations. Ilmenite from the Grib kimberlite has Zr concentrations <110 ppm, whereas ilmenite from the Kepino kimberlites has Zr concentrations >300 ppm. Ilmenite crystallisation within the Grib kimberlite occurred under increasing oxygen fugacity (fO 2), which may reflect assimilation of mantle peridotite by the kimberlitic magmas. Ilmenite from the Kepino kimberlites suggests its crystallisation under constant fO 2 , with the ilmenite composition being controlled by processes of fractional crystallisation of megacrystic minerals. These assumptions were confirmed with assimilation-fractional crystallisation calculations. On the basis of obtained data, we developed a model for the evolution of the kimberlitic magmas for both diamon-diferous and barren kimberlites. The diamond-bearing kimberlitic magmas were generated under intense interaction of kimberlitic magmas with the surrounding lithospheric mantle. It may be that during early modification of the lithospheric mantle by kimberlitic magmas as well as with kimberlitic magmas' local stretching and swift ascent, the capture of the mantle xenoliths was favoured over the crystallisation of phenocrysts. The formation of barren kimberlitic magmas may have occurred when the lithospheric mantle in the vicinity of ascending magmas was already geochemically equilibrated with them. It also is possible that the magma's ascent slowed under conditions of dominantly compressive stresses with crystallisation of olivine and other megacrystic phases.
DS202010-1849
2020
Burmii, J.P.Kargin, A.V., Nosova, A.A., Sazonova, L.V., Peresetskaya, E.V., Golubeva, Yu.Yu., Lebedeva, N.M., Tretyachenko, V.V., Khvostikov, V.A., Burmii, J.P.Ilmenite from the Arkangelsk diamond province, Russia: composition, origin and indicator of diamondiferous kimberlites.Petrology, Vol. 28, 4, pp. 315-337. pdfRussia, Archangeldeposit - Grib, Kepino cluster

Abstract: To provide new insights into the origin and evolution of kimberlitic magmas with different diamond concentrations from the Arkhangelsk diamond province in north-western Russia, we examined the major- and trace-element compositions of ilmenite from diamondiferous kimberlite of the Grib pipe and diamond-barren kimberlites from the Kepino cluster (Stepnaya and TsNIGRI-Arkhangelskaya pipes). Ilmenite from diamond-barren kimberlites shows lower Mg, Ti, Cr, Ni and Cu concentrations with increase in both Fe3+ and Fe2+ and Nb, Ta, Zr, Hf, Zn and V concentrations. The main differences between kimberlites with different diamond contents are the Nb and Zr concentrations and their correlation patterns with Mg and Cr concentrations. Ilmenite from the Grib kimberlite has Zr concentrations <110 ppm, whereas ilmenite from the Kepino kimberlites has Zr concentrations >300 ppm. Ilmenite crystallisation within the Grib kimberlite occurred under increasing oxygen fugacity (fO2), which may reflect assimilation of mantle peridotite by the kimberlitic magmas. Ilmenite from the Kepino kimberlites suggests its crystallisation under constant fO2, with the ilmenite composition being controlled by processes of fractional crystallisation of megacrystic minerals. These assumptions were confirmed with assimilation-fractional crystallisation calculations. On the basis of obtained data, we developed a model for the evolution of the kimberlitic magmas for both diamondiferous and barren kimberlites. The diamond-bearing kimberlitic magmas were generated under intense interaction of kimberlitic magmas with the surrounding lithospheric mantle. It may be that during early modification of the lithospheric mantle by kimberlitic magmas as well as with kimberlitic magmas’ local stretching and swift ascent, the capture of the mantle xenoliths was favoured over the crystallisation of phenocrysts. The formation of barren kimberlitic magmas may have occurred when the lithospheric mantle in the vicinity of ascending magmas was already geochemically equilibrated with them. It also is possible that the magma’s ascent slowed under conditions of dominantly compressive stresses with crystallisation of olivine and other megacrystic phases.
DS201612-2311
2016
Burmii, Z.P.Kargin, A.V., Sazonova, L.V., Nosova, A.A., Pervov, V.A., Minevrina, E.V., Khvostikov, V.A., Burmii, Z.P.Sheared peridotite xenolith from the V. Grib kimberlite pipe, Arkangelsk diamond province, Russia: texture, composition and origin.Geoscience Frontiers, in press availableRussia, Archangel, Kola PeninsulaDeposit - Grib
DS201705-0863
2017
Burmii, Zh.P.Nosova, A.A., Dubinina, E.O., Sazonova, L.V., Vargin, A.V., lebedeva, N.M., Khvostikov, V.A., Burmii, Zh.P., Kondrashov, I.A., Tretyachenko, V.V.Geochemistry and oxygen isotopic composition of olivine in kimberlites from the Arkhangelsk Province: contribution of mantle metasomatism.Petrology, Vol. 25, 2, pp. 150-180.Russia, Archangel, Kola PeninsulaDeposit - Grib, Pionerskaya

Abstract: The paper presents data on the composition of olivine macrocrysts from two Devonian kimberlite pipes in the Arkhangelsk diamond province: the Grib pipe (whose kimberlite belongs to type I) and Pionerskaya pipe (whose kimberlite is of type II, i.e., orangeite). The dominant olivine macrocrysts in kimberlites from the two pipes significantly differ in geochemical and isotopic parameters. Olivine macrocrysts in kimberlite from the Grib pipe are dominated by magnesian (Mg# = 0.92-0.93), Ti-poor (Ti < 70 ppm) olivine possessing low Ti/Na (0.05-0.23), Zr/Nb (0.28-0.80), and Zn/Cu (3-20) ratios and low Li concentrations (1.2-2.0 ppm), and the oxygen isotopic composition of this olivine ?18O = 5.64‰ is higher than that of olivine in mantle peridotites (?18O = 5.18 ± 0.28‰). Olivine macrocrysts in kimberlite from the Pionerskaya pipe are dominated by varieties with broadly varying Mg# = 0.90-0.93, high Ti concentrations (100-300 ppm), high ratios Ti/Na (0.90-2.39), Zr/Nb (0.31-1.96), and Zn/Cu (12-56), elevated Li concentrations (1.9-3.4 ppm), and oxygen isotopic composition ?18O = 5.34‰ corresponding to that of olivine in mantle peridotites. The geochemical and isotopic traits of low-Ti olivine macrocrysts from the Grib pipe are interpreted as evidence that the olivine interacted with carbonate-rich melts/fluids. This conclusion is consistent with the geochemical parameters of model melt in equilibrium with the low-Ti olivine that are similar to those of deep carbonatite melts. Our calculations indicate that the variations in the ?18O of the olivine relative the “mantle range” (toward both higher and lower values) can be fairly significant: from 4 to 7‰ depending on the composition of the carbonate fluid. These variations were formed at interaction with carbonate fluid, whose ?18O values do not extend outside the range typical of mantle carbonates. The geochemical parameters of high-Ti olivine macrocrysts from the Grib pipe suggest that their origin was controlled by the silicate (water-silicate) component. This olivine is characterized by a zoned Ti distribution, with the configuration of this distribution between the cores of the crystals and their outer zones showing that the zoning of the cores and outer zones is independent and was produced during two episodes of reaction interaction between the olivine and melt/fluid. The younger episode (when the outer zone was formed) likely involved interaction with kimberlite melt. The transformation of the composition of the cores during the older episode may have been of metasomatic nature, as follows from the fact that the composition varies from grain to grain. The metasomatic episode most likely occurred shortly before the kimberlite melt was emplaced and was related to the partial melting of pyroxenite source material.
DS201707-1353
2017
Burmii, Zh.P.Nosova, A., Tretyachenko, V.V., Sazonova, L.V., Kargin, A.V., Lebedeva, N.M., Khovostikov, V.A., Burmii, Zh.P., Kondrorashov, I.A., Tretyachenko, V.V.Geochemistry and oxygen isotopic composition of olivine in kimberlites from the Arkhangelsk province: contribution of mantle metasomatism.Petrology, Vol. 25, 2, pp. 150-180.Russia, Archangel, Kola Peninsuladeposit - Grib, Pionerskaya

Abstract: The paper presents data on the composition of olivine macrocrysts from two Devonian kimberlite pipes in the Arkhangelsk diamond province: the Grib pipe (whose kimberlite belongs to type I) and Pionerskaya pipe (whose kimberlite is of type II, i.e., orangeite). The dominant olivine macrocrysts in kimberlites from the two pipes significantly differ in geochemical and isotopic parameters. Olivine macrocrysts in kimberlite from the Grib pipe are dominated by magnesian (Mg# = 0.92–0.93), Ti-poor (Ti < 70 ppm) olivine possessing low Ti/Na (0.05–0.23), Zr/Nb (0.28–0.80), and Zn/Cu (3–20) ratios and low Li concentrations (1.2–2.0 ppm), and the oxygen isotopic composition of this olivine ?18O = 5.64‰ is higher than that of olivine in mantle peridotites (?18O = 5.18 ± 0.28‰). Olivine macrocrysts in kimberlite from the Pionerskaya pipe are dominated by varieties with broadly varying Mg# = 0.90–0.93, high Ti concentrations (100–300 ppm), high ratios Ti/Na (0.90–2.39), Zr/Nb (0.31–1.96), and Zn/Cu (12–56), elevated Li concentrations (1.9–3.4 ppm), and oxygen isotopic composition ?18O = 5.34‰ corresponding to that of olivine in mantle peridotites. The geochemical and isotopic traits of low-Ti olivine macrocrysts from the Grib pipe are interpreted as evidence that the olivine interacted with carbonate-rich melts/fluids. This conclusion is consistent with the geochemical parameters of model melt in equilibrium with the low-Ti olivine that are similar to those of deep carbonatite melts. Our calculations indicate that the variations in the ?18O of the olivine relative the “mantle range” (toward both higher and lower values) can be fairly significant: from 4 to 7‰ depending on the composition of the carbonate fluid. These variations were formed at interaction with carbonate fluid, whose ?18O values do not extend outside the range typical of mantle carbonates. The geochemical parameters of high-Ti olivine macrocrysts from the Grib pipe suggest that their origin was controlled by the silicate (water–silicate) component. This olivine is characterized by a zoned Ti distribution, with the configuration of this distribution between the cores of the crystals and their outer zones showing that the zoning of the cores and outer zones is independent and was produced during two episodes of reaction interaction between the olivine and melt/fluid. The younger episode (when the outer zone was formed) likely involved interaction with kimberlite melt. The transformation of the composition of the cores during the older episode may have been of metasomatic nature, as follows from the fact that the composition varies from grain to grain. The metasomatic episode most likely occurred shortly before the kimberlite melt was emplaced and was related to the partial melting of pyroxenite source material.
DS200812-0160
2008
Burmin, V.A.Yu.A.Burmin, V.A.Yu.A.Viscosity of the Earth's core based on seismic data.Doklady Earth Sciences, Vol. 419, 1, pp. 316-319.MantleGeophysics - seismics
DS200812-0161
2008
Burmin, V.A.Yu.A.Burmin, V.A.Yu.A.Viscosity of the Earth's core based on seismic data.Doklady Earth Sciences, Vol. 419, 2, pp. 316-319.MantleGeophysics - seismics
DS200812-0102
2008
Burmistrov, A.A.Belov, S.V., Burmistrov, A.A., Soloviev, A.A., Kedrov, E.O.Carbonatites and kimberlites of the world... database and geoinformation system: experience of creation and use for solving geological tasks.AIP Conference Proceedings, American Institute of Physics, No. 1009, pp. 113-122.GlobalDatabase
DS200712-0511
2007
Burn, C.R.Karunaratne, K.C., Burn, C.R.Active layer thermal regime of the Ekati diamond mine tailings facility.Geological Association of Canada, Gac-Mac Yellowknife 2007, May 23-25, Volume 32, 1 pg. abstract p.41-42.Canada, Northwest TerritoriesEkati - mining
DS201806-1222
2018
Burn, M.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.
DS1994-0236
1994
Burn, R.G.Burn, R.G.Reduction of mining investment risk through use of quality controlRisk Assessment in the extractive industries March 23-24th. 1994, 10pGlobalEconomics, ore reserve evaluation, Quality control
DS200612-0384
2006
Burnaeva, M.Yu.Evdokimov, A.N., Burnaeva, M.Yu., Radina, E.S., Sirotkin, A.N.The first find of kimberlitic accessory minerals in mafic-ultramafic dikes in Spitsbergen.Doklady Earth Sciences, Vol. 407, 2, Feb-Mar. pp. 275-279.Europe, NorwayGeochemistry
DS200912-0089
2009
Burnaeva, M.Yu.Burnaeva, M.Yu., Antonov, A.V., Sirotkin, A.N.The typochemical features of pyroxenes from Paleozoic picrite dikes within Spitsbergen Archipelago.alkaline09.narod.ru ENGLISH, May 10, 2p. abstractEurope, Spitzbergen IslandPicrite
DS1999-0291
1999
Burnard, P.Harrison, D., Burnard, P., Turner, G.Noble gas behaviour and composition in the mantle: constraints from Icelandplume.Earth and Planetary Science Letters, Vol. 171, No. 2, Aug. 30, pp. 199-208.GlobalGeochemistry, Plume
DS1999-0292
1999
Burnard, P.Harrison, D., Burnard, P., Turner, G.Noble gas behaviour and composition in the mantle: constraints from the Iceland plume.Earth and Planetary Science Letters, Vol. 171, pp. 199-207.GlobalModels, plumes, mantle
DS200412-0248
2004
Burnard, P.Burnard, P.Diffusive fractionation of noble gases and helium isotopes during mantle melting.Earth and Planetary Science Letters, Vol. 220, 3-4, pp. 287-295.MantleGeochronology
DS200612-0200
2006
Burnard, P.Burnard, P., Basset, R., Marty, B., Fischer, T., Palhol, F., Mangasini, F., Makene, C.Xe isotopes in carbonatites: Oldonyo Lengai, East African Rift.Geochimica et Cosmochimica Acta, Vol. 70, 18, p. 1, abstract only.Africa, TanzaniaCarbonatite
DS201012-0080
2010
Burnard, P.Burnard, P., Toplis, M.J., Medynski, S.Low solubility of He and Ar carbonatitic liquids: implications for decoupling noble gas and lithophile isotope systems.Geochimica et Cosmochimica Acta, Vol. 74, 5, pp. 1672-1683.MantleCarbonatite
DS201709-2034
2017
Burnard, P.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.
DS1994-0237
1994
Burne, G.Burne, G.Maintaining the balance -Canada and the CSOProspectors and Developers Association of Canada (PDAC) Annual Meeting March 6-9th. held Toronto, Ontario, Final program abstract volume, p. 48, 49.CanadaEconomics, CSO
DS1995-0242
1995
Burne, G.F.H.Burne, G.F.H.It's all in the marketingSpeech to Canaccord, Oct. 25, 1995, 12p. plus 3 graphs.GlobalDiamond outlook, CSO Marketing
DS1982-0605
1982
Burne, R.V.Tratt, M.H., Burne, R.V.Impregnation of Unconsolidated Sediment Samples, Using a Large Vacuum Chamber.B.m.r. Journal of Aust. Geol. Geophys., Vol. 7, No. 3, PP. 225-226.AustraliaSampling, Geochemistry, Alluvials
DS1990-0256
1990
Burness, H.S.Burness, H.S., Martin, W.E.The effects of global warming on the mining industry:issues, tradeoff sand optionsColorado School of Mines, Department of Mineral Economics, Working Paper, No. 90-3, 46pGlobalMining industry, Economics-global warming
DS201607-1336
2016
Burness, S.Burness, S.The role of sulphur during partial melting of the eclogitic cratonic mantle.IGC 35th., Session A Dynamic Earth 1p. AbstractMantleEclogite
DS201708-1606
2017
Burness, S.Burness, S.The role of sulphur during partial melting of eclogite in the cratonic mantle: constraints from experiments and xenoliths.11th. International Kimberlite Conference, PosterMantleeclogite
DS201710-2218
2017
Burness, S.Burness, S., Smart, K.A., Stevens, G., Tappe, S., Sharp, Z.D., Gibbons, J.S-bearing metasomatism of mantle eclogites: constraints from the Kaapvaal craton and experiments.Goldschmidt Conference, 1p. AbstractAfrica, South Africadeposit - Roberts Victor, Jagersfontein
DS201909-2094
2019
Burness, S.Tappe, S., Burness, S., Smart, K., Magna, T., Stracke, A.Views of plate tectonics and mantle metal budgets from alkaline and carbonate magmas.Goldschmidt2019, 1p. AbstractGlobalalkaline rocks

Abstract: Low-volume alkaline silicate and carbonate magmas are products of volatile-controlled incipient melting processes in the Earth’s mantle. Although this form of melting is ubiquitous beneath the thick and cold portions of continental lithosphere, such melts rarely reach the Earth’s surface due to a combination of their small volumes, reactive nature, and great depths of origin. In spite of being rare at surface, the impact of alkaline and carbonate magmatism on the dynamic stability of mantle lithosphere and its metal endowment may be disproportionately large, but it is difficult to grasp in the absence of spatial and temporal constraints on melt mobility. We review evidence from major alkaline and carbonatite provinces for metasomatic overprinting of the underlying continental mantle lithosphere, and evaluate how these processes influenced plate tectonic evolution in these regions. Key examples from Greenland and Africa show that metasomatic weakening of mantle lithosphere by pervasive alkaline and carbonate melts is frequently the first step in continent fragmentation ultimately leading to supercontinent dispersal. A major obstacle in identifying carbonate melt metasomatized mantle is the use of differentiated ‘surface’ carbonatite compositions as proxies for geochemical processes operating at great depths. We assess the robustness of some of the classic geochemical proxies, such as Ti/Eu and Zr/Sm, and identify new promising fingerprints of passing carbonate melts in the deep mantle lithosphere. New evidence from the Kaapvaal craton, one of world’s best endowed metallogenic provinces, shows that redox- and volatile-controlled alkaline melting events can effectively mobilize sulphide-hosted PGE and base metal budgets from eclogite components within the thick mantle lithosphere. Such precursor alkaline magmatic events, heralding the formation of major continental rifts and mantle plume impingement, can enhance the metal contents of subsequent asthenosphere-derived mafic magmas, thereby upgrading oreforming potential. However, economic metal deposits only form when geologic conditions during magma emplacement in the crust are favorable, with mantle metal budgets being less critical.
DS202003-0333
2020
Burness, S.Burness, S., Smart, K.A., Tappe, S., Stevens, G., Woodland, A.B., Cano, E.Sulphur rich mantle metasomatism of Kaapvaal craton eclogites and its role in redox controlled platinum group element mobility. Xenoliths from Roberts Victor, Jagersfontein, Kimberley ( Kamfersdam), PremierChemical Geology, in press available 57p.Africa, South Africametasomatism

Abstract: Eclogite mantle xenoliths from various kimberlite occurrences on the Kaapvaal craton show evidence for depth- and redox-dependent metasomatic events that led to variable base metal sulphide and incompatible element enrichments. Eclogite xenoliths from the Roberts Victor, Jagersfontein, Kimberley (Kamfersdam) and Premier kimberlites were investigated for their silicate and base metal sulphide geochemistry, stable oxygen isotope compositions and oxybarometry. The variably metasomatised eclogites had basaltic, picritic and gabbroic protolith compositions and have garnet ?18O values that range from +3.3 to +7.9‰, which, when coupled with the trace element characteristics, indicate oceanic lithosphere protoliths that had undergone variable degrees of seawater alteration. The deepest equilibrated eclogites (175220?km depth) from near the base of the Kaapvaal craton lithosphere are the most refractory and feature significant light rare earth element (LREE) depletions. They show the most oxidised redox compositions with ?logƒO2 values of FMQ-3.9 to FMQ-1.5. Subtle metasomatic overprinting of these eclogites resulted in base metal sulphide formation with relatively depleted and highly fractionated HSE compositions. These deepest eclogites and their included base metal sulphides suggest interaction with relatively oxidised melts or fluids, which, based on their HSE characteristics, could be related to precursor kimberlite metasomatism that was widespread within the Kaapvaal craton mantle lithosphere. In contrast, eclogites that reside at shallower, “mid-lithospheric” depths (140180?km) have been enriched in LREE and secondary diopside/phlogopite. Importantly, they host abundant metasomatic base metal sulphides, which have higher HSE contents than those in the deeper eclogites at the lithosphere base. The mid-lithospheric eclogites have more reducing redox compositions (?logfO2?=?FMQ-5.3 ? FMQ-3.3) than the eclogites from the lowermost Kaapvaal lithosphere. The compositional overprint of the shallower mantle eclogites resembles basaltic rather than kimberlitic/carbonatitic metasomatism, which is also supported by their relatively reducing redox state. Base metal sulphides from the mid-lithospheric eclogites have HSE abundances and distributions that are similar to Karoo flood basalts from southern Africa, suggesting a link between the identified shallow mantle metasomatism of the Kaapvaal cratonic lithosphere and the Karoo large igneous event during the Mesozoic. The sulphide-hosted platinum group element abundances of the mid-lithospheric eclogites are higher compared with their analogues from the deeper lithospheric eclogites, which in combination with their contrasting oxidation states, may imply redox-controlled HSE mobility during sulphur-rich metasomatism of continental mantle lithosphere.
DS202008-1372
2020
Burness, S.Burness, S., Smart, K.A., Tappe, S., Stevens, G., Woodland, A.B., Cano, E.Sulphur rich mantle metasomatism of Kaapvaal craton eclogites and its role in redox controlled platinum group element mobility.Chemical Geology, Voll. 542, 119476 23p. pdfAfrica, South Africadeposit - Roberts Victor, Jagersfontein, Kimberley, Kamfersdam, Premier

Abstract: Eclogite mantle xenoliths from various kimberlite occurrences on the Kaapvaal craton show evidence for depth- and redox-dependent metasomatic events that led to variable base metal sulphide and incompatible element enrichments. Eclogite xenoliths from the Roberts Victor, Jagersfontein, Kimberley (Kamfersdam) and Premier kimberlites were investigated for their silicate and base metal sulphide geochemistry, stable oxygen isotope compositions and oxybarometry. The variably metasomatised eclogites had basaltic, picritic and gabbroic protolith compositions and have garnet ?18O values that range from +3.3 to +7.9‰, which, when coupled with the trace element characteristics, indicate oceanic lithosphere protoliths that had undergone variable degrees of seawater alteration. The deepest equilibrated eclogites (175-220 km depth) from near the base of the Kaapvaal craton lithosphere are the most refractory and feature significant light rare earth element (LREE) depletions. They show the most oxidised redox compositions with ?logƒO2 values of FMQ-3.9 to FMQ-1.5. Subtle metasomatic overprinting of these eclogites resulted in base metal sulphide formation with relatively depleted and highly fractionated HSE compositions. These deepest eclogites and their included base metal sulphides suggest interaction with relatively oxidised melts or fluids, which, based on their HSE characteristics, could be related to precursor kimberlite metasomatism that was widespread within the Kaapvaal craton mantle lithosphere. In contrast, eclogites that reside at shallower, “mid-lithospheric” depths (140-180 km) have been enriched in LREE and secondary diopside/phlogopite. Importantly, they host abundant metasomatic base metal sulphides, which have higher HSE contents than those in the deeper eclogites at the lithosphere base. The mid-lithospheric eclogites have more reducing redox compositions (?logfO2 = FMQ-5.3 ? FMQ-3.3) than the eclogites from the lowermost Kaapvaal lithosphere. The compositional overprint of the shallower mantle eclogites resembles basaltic rather than kimberlitic/carbonatitic metasomatism, which is also supported by their relatively reducing redox state. Base metal sulphides from the mid-lithospheric eclogites have HSE abundances and distributions that are similar to Karoo flood basalts from southern Africa, suggesting a link between the identified shallow mantle metasomatism of the Kaapvaal cratonic lithosphere and the Karoo large igneous event during the Mesozoic. The sulphide-hosted platinum group element abundances of the mid-lithospheric eclogites are higher compared with their analogues from the deeper lithospheric eclogites, which in combination with their contrasting oxidation states, may imply redox-controlled HSE mobility during sulphur-rich metasomatism of continental mantle lithosphere.
DS202110-1604
2021
Burness, S.Burness, S., Thomassot, E., Smart, K., Tappe, S.Sulphur isotopes in sulphides from cratonic mantle eclogites: a glimpse of volatile recycling in ancient subduction zones.Earth and Planetary Science Letters, Vol. 572, 1, 117118Africa, South Africadeposit - Premier, Roberts Victor, Jagersfontein

Abstract: Multiple sulphur isotopic compositions of sulphides from Kaapvaal craton mantle eclogites allow to elucidate the recycling of sulphur into the deep Earth and to differentiate between recycled crust and mantle origins of eclogite-hosted sulphides, including the precious metals that they capture. We present multiple sulphur isotope ratio measurements by secondary ion mass spectrometry for sulphides from a collection of mantle-derived eclogite xenoliths from Proterozoic and Mesozoic kimberlite occurrences in South Africa (Premier, Roberts Victor, Jagersfontein). Previous work established that the host eclogites have elemental and oxygen isotopic compositions in support of seawater-altered oceanic lithosphere protoliths, and for many of these xenolith suites Archean ages have been suggested. The eclogite-hosted sulphides have values from ?5.7 to ‰, with the upper end of this wide range representing the highest-ever recorded composition of material derived from the Earth's mantle. The values range from ?0.29 to ‰ and do not record significant mass-independent sulphur isotope fractionation, i.e., there is no compelling S-MIF signature. Most of the sulphide grains have values that fall within a range between ?6 and ‰, and they probably retain an isotopic record of sulphides that formed originally within altered oceanic crust. In contrast, the highly positive values from +13 to ‰ detected in sulphide grains from a single eclogite xenolith are similar to those of marine sulphates, which were probably a minor sulphur component of the oceanic crustal protolith. The lack of a significant S-MIF signature in the eclogitic sulphides that show evidence for a recycled crust origin implies that this sulphur component stems from a post-Archean surficial reservoir. This finding suggests that the cratonic mantle eclogites may have formed from post-Archean oceanic crust (e.g., Paleoproterozoic eclogite protoliths), or - as is preferred here - the ‘surficial’ sulphur was introduced into the cratonic root during relatively young metasomatic events and is thus unrelated to eclogite petrogenesis and Archean continent formation.
DS202201-0007
2021
Burness, S.M.Burness, S.M., Thomassot, E., Smart, K., Tappe, S.Sulphur isotopes ( 34S and 33S ) in sulphides from cratonic mantle eclogites: a glimpse of volatile cycling in ancient subduction zones.Earth and Planetary Science Letters, Vol. 572, 13p. PdfMantleeclogites

Abstract: Multiple sulphur isotopic compositions of sulphides from Kaapvaal craton mantle eclogites allow to elucidate the recycling of sulphur into the deep Earth and to differentiate between recycled crust and mantle origins of eclogite-hosted sulphides, including the precious metals that they capture. We present multiple sulphur isotope ratio measurements by secondary ion mass spectrometry for sulphides from a collection of mantle-derived eclogite xenoliths from Proterozoic and Mesozoic kimberlite occurrences in South Africa (Premier, Roberts Victor, Jagersfontein). Previous work established that the host eclogites have elemental and oxygen isotopic compositions in support of seawater-altered oceanic lithosphere protoliths, and for many of these xenolith suites Archean ages have been suggested. The eclogite-hosted sulphides have ?34S values from -5.7 to + 29 ‰, with the upper end of this wide range representing the highest-ever recorded ?34S composition of material derived from the Earth's mantle. The ?33S values range from -0.29 to + 0.18 ‰ and do not record significant mass-independent sulphur isotope fractionation, i.e., there is no compelling S-MIF signature. Most of the sulphide grains have ?34S values that fall within a range between -6 and + 4 ‰, and they probably retain an isotopic record of sulphides that formed originally within altered oceanic crust. In contrast, the highly positive ?34S values from +13 to + 29 ‰ detected in sulphide grains from a single eclogite xenolith are similar to those of marine sulphates, which were probably a minor sulphur component of the oceanic crustal protolith. The lack of a significant S-MIF signature in the eclogitic sulphides that show ?34S evidence for a recycled crust origin implies that this sulphur component stems from a < 2.4Ga post-Archean surficial reservoir. This finding suggests that the cratonic mantle eclogites may have formed from post-Archean oceanic crust (e.g., Paleoproterozoic eclogite protoliths), or - as is preferred here - the 'surficial' sulphur was introduced into the cratonic root during relatively young metasomatic events and is thus unrelated to eclogite petrogenesis and Archean continent formation.
DS1989-0834
1989
BurnettKuehner, S.M., Laughlin, J.R., Grossman, L., Johnson, M.L., BurnettDetermination of trace element mineral/liquid partition coefficients in melilite and diopside by ion and electron microprobe techniquesGeochimica et Cosmochimica Acta, Vol. 53, pp. 3115-3130GlobalMelilite, Experimental petrology
DS200712-1132
2007
Burnett, D.Wang, J., Nittler, L.R., Burnett, D.Solar wind Mg, Cr and Fe abundances in diamond like carbon collector from Gemesis mission.Plates, Plumes, and Paradigms, 1p. abstract p. A1085.TechnologyCarbon
DS1992-1020
1992
Burnett, J.McArthur, J.M., Burnett, J., Hancock, J.M.Strontium isotopes at K/T boundaryNature, Vol. 355, No. 6355, January 2, p.28GlobalBoundary, Geochronology
DS201708-1607
2017
Burnham, A.Burnham, A.The nitrogen budget of subducted crust.11th. International Kimberlite Conference, PosterMantlenitrogen
DS201812-2886
2018
Burnham, A.Smith, C.B., Bulanova, G.P., Kobussen, A.F., Burnham, A., Chapman, J.G., Davy, A.T., Sinha, K.K.Bunder deposit: Diamonds from the Atri South pipe, Bunder lamproite field, India, and implications for the nature of the underlying mantle.Society of Economic Geology Geoscience and Exploration of the Argyle, Bunder, Diavik, and Murowa Diamond Deposits, Special Publication no. 20, pp. 237-252.Indiadeposit - Bunder
DS201312-0111
2013
Burnham, A.D.Burnham, A.D., Kohn, S.C., Potoszil, C., Walter, M.J., Bulanova, G.P., Thomson, A.R., Smith, C.B.The redox state of diamond forming fluids: constraints from Fe3/Fe2+ of garnets.Goldschmidt 2013, AbstractMantleGeothermometry
DS201512-1900
2015
Burnham, A.D.Burnham, A.D., Thomson, A.R., Bulanova, G.P., Kohn, S.C., Smith, C.B., Walter, M.J.Stable isotope evidence for crustal recycling as recorded by superdeep diamonds.Earth and Planetary Science Letters, Vol. 432, pp. 374-380.South America, BrazilDeposit - Juina-5, Collier-4, Machado River

Abstract: Sub-lithospheric diamonds from the Juina-5 and Collier-4 kimberlites and the Machado River alluvial deposit in Brazil have carbon isotopic compositions that co-vary with the oxygen isotopic compositions of their inclusions, which implies that they formed by a mixing process. The proposed model for this mixing process, based on interaction of slab-derived carbonate melt with reduced (carbide- or metal-bearing) ambient mantle, explains these isotopic observations. It is also consistent with the observed trace element chemistries of diamond inclusions from these localities and with the experimental phase relations of carbonated subducted crust. The 18O-enriched nature of the inclusions demonstrates that they incorporate material from crustal protoliths that previously interacted with seawater, thus confirming the subduction-related origin of superdeep diamonds. These samples also provide direct evidence of an isotopically anomalous reservoir in the deep (?350 km) mantle.
DS201608-1396
2016
Burnham, A.D.Burnham, A.D., Bulanova, G.P., Smith, C.B., Whitehead, S.C., Kohn, S.C., Gobbo, L., Walter, M.J.Diamonds from the Machado River alluvial deposit, Rondona, Brazil, derived from both lithospheric and sublithospheric mantle.Lithos, in press available, 15p.South America, BrazilMorphology, textures, chemistry

Abstract: Diamonds from the Machado River alluvial deposit have been characterised on the basis of external morphology, internal textures, carbon isotopic composition, nitrogen concentration and aggregation state and mineral inclusion chemistry. Variations in morphology and features of abrasion suggest some diamonds have been derived directly from local kimberlites, whereas others have been through extensive sedimentary recycling. On the basis of mineral inclusion compositions, both lithospheric and sublithospheric diamonds are present at the deposit. The lithospheric diamonds have clear layer-by-layer octahedral and/or cuboid internal growth zonation, contain measurable nitrogen and indicate a heterogeneous lithospheric mantle beneath the region. The sublithospheric diamonds show a lack of regular sharp zonation, do not contain detectable nitrogen, are isotopically heavy (?13CPDB predominantly ? 0.7 to ? 5.5) and contain inclusions of ferropericlase, former bridgmanite, majoritic garnet and former CaSiO3-perovskite. This suggests source lithologies that are Mg- and Ca-rich, probably including carbonates and serpentinites, subducted to lower mantle depths. The studied suite of sublithospheric diamonds has many similarities to the alluvial diamonds from Kankan, Guinea, but has more extreme variations in mineral inclusion chemistry. Of all superdeep diamond suites yet discovered, Machado River represents an end-member in terms of either the compositional range of materials being subducted to Transition Zone and lower mantle or the process by which materials are transferred from the subducted slab to the diamond-forming region.
DS201611-2142
2016
Burnham, A.D.Smith, C.B., Walter, M.J., Bulanova, G.P., Mikhail, S., Burnham, A.D., Gobbo, L., Kohn, S.C.Diamonds from Dachine, French Guiana: a unique record of Early Proterozoic subduction.Lithos, in press available 66p.South America, French GuianaDeposit - Dachine

Abstract: Diamonds from Dachine, French Guiana, are unique among worldwide diamond populations. The diamonds were transported to the surface in an unusual ultramafic extrusive magma with an affinity to boninite or komatiite, which was emplaced within an arc geological setting at ~ 2.2 Ga. Dachine diamonds have internal and external morphologies indicative of relatively rapid growth from carbon oversaturated fluids or melts, and exhibit internal features consistent with residence in a high-strain environment. On the basis of nitrogen (N) defects the diamonds are categorized as Type Ib-IaA. The unusually low aggregation state of N places severe constraints on the thermal history of the diamonds, effectively ruling out derivation in convecting mantle. The carbon and N isotopic compositions of Dachine diamonds are consistent with a sedimentary source of carbon, with the majority of diamonds having ?13C values < ? 25‰ and ?15N values > + 4‰. The primary carbon was presumably deposited on an early Proterozoic seafloor. Sulphide inclusions have low Ni and Cr and are comparable to lithospheric eclogitic-type sulphide inclusions. Three garnet and one clinopyroxene inclusion are also eclogitic in composition, and one garnet inclusion has a majorite component indicating an origin around 250 km depth. The silicate inclusions are highly depleted in many incompatible trace elements (e.g. LREE, Nb, Hf, Zr), and modelling indicates an eclogitic source lithology that contained a LREE-enriched trace phase such as epidote or allanite, and an HFSE-rich phase such as rutile. Four of the five inclusions are unusually enriched in Mn, as well as Ni and Co, and modelling indicates a protolith with the bulk composition of subducted normal MORB plus about 10% ferromanganese crust component. We suggest a model wherein Dachine diamonds precipitated from remobilized sedimentary carbon at the slab-mantle interface from liquids derived ultimately by deserpentinization of slab peridotite at depths of ~ 200 to 250 km. These fluids may also trigger melting in wedge peridotite, resulting in a volatile-rich ultramafic melt that transports the diamonds rapidly to the surface. The process of diamond formation and exhumation from the slab mantle interface likely occurred in a Paleoproterozoic subduction zone and over a very limited timespan, likely less than a million years.
DS201706-1065
2017
Burnham, A.D.Burnham, A.D., Berry, A.J.Formation of Hadean granites by melting of igneous crust.Nature Geoscience, in press May 8 availableAustraliaJack Hills zircon

Abstract: The oldest known samples of Earth, with ages of up to 4.4?Gyr, are detrital zircon grains in meta-sedimentary rocks of the Jack Hills in Australia. These zircons offer insights into the magmas from which they crystallized, and, by implication, igneous activity and tectonics in the first 500 million years of Earth’s history, the Hadean eon. However, the compositions of these magmas and the relative contributions of igneous and sedimentary components to their sources have not yet been resolved. Here we compare the trace element concentrations of the Jack Hills zircons to those of zircons from the locality where igneous (I-) and sedimentary (S-) type granites were first distinguished. We show that the Hadean zircons crystallized predominantly from I-type magmas formed by melting of a reduced, garnet-bearing igneous crust. Further, we propose that both the phosphorus content of zircon and the ratio of phosphorus to rare earth elements can be used to distinguish between detrital zircon grains from I- and S-type sources. These elemental discriminants provide a new geochemical tool to assess the relative contributions of primeval magmatism and melting of recycled sediments to the continents over geological time.
DS201712-2711
2016
Burnham, A.D.Nestola, F., Burnham, A.D., Peruzzo, L., Tauro, L., Alvaro, M., Walter, M.J., Gunter, M., Anzolini, C., Kohn, S.C.Tetragonal almandine-pyrope phase, TAPP: finally a name for it, the new name jeffbenite.Mineralogical Magazine, Vol. 80, pp. 1219-1232.Technologypyrope

Abstract: Jeffbenite, ideally Mg3Al2Si3O8, previously known as tetragonal-almandine-pyrope-phase (‘TAPP’), has been characterized as a new mineral from an inclusion in an alluvial diamond from São Luiz river, Juina district of Mato Grosso, Brazil. Its density is 3.576 g/cm3 and its microhardness is ?7. Jeffbenite is uniaxial (-) with refractive indexes ??=?1.733(5) and ??=?1.721(5). The crystals are in general transparent emerald green. Its approximate chemical formula is (Mg2.62Fe2+0.27)(Al1.86Cr0.16)(Si2.82Al0.18)O12 with very minor amounts of Mn, Na and Ca. Laser ablation ICP-MS showed that jeffbenite has a very low concentration of trace elements. Jeffbenite is tetragonal with space group I4¯2d, cell edges being a?=?6.5231(1) and c?=?18.1756(3) Å. The main diffraction lines of the powder diagram are [d (in Å), intensity, hkl]: 2.647, 100, 2 0 4; 1.625, 44, 3 2 5; 2.881, 24, 2 1 1; 2.220, 19, 2 0 6; 1.390, 13, 4 2 4; 3.069, 11, 2 0 2; 2.056, 11, 2 2 4; 1.372, 11, 2 0 12. The structural formula of jeffbenite can be written as (M1)(M2)2(M3)2(T1)(T2)2O12 with M1 dominated by Mg, M2 dominated by Al, M3 dominated again by Mg and both T1 and T2 almost fully occupied by Si. The two tetrahedra do not share any oxygen with each other (i.e. jeffbenite is classified as an orthosilicate). Jeffbenite was approved as a new mineral by the IMA Commission on New Minerals and Mineral Names with the code IMA 2014-097. Its name is after Jeffrey W. Harris and Ben Harte, two world-leading scientists in diamond research. The petrological importance of jeffbenite is related to its very deep origin, which may allow its use as a pressure marker for detecting super-deep diamonds. Previous experimental work carried out on a Ti-rich jeffbenite establishes that it can be formed at 13 GPa and 1700 K as maximum P-T conditions.
DS201908-1818
2019
Burnham, A.D.Timmerman, S., Honda, M., Zhang, X., Jaques, A.L., Bulanova, G., Smith, C.B., Burnham, A.D.Contrasting noble gas compositions of peridotitic and eclogitic monocrystalline diamonds from the Argyle lamproite, Western Australia.Lithos, Vol. 344-345, pp. 193-206.Australiadeposit - Argyle

Abstract: He-Ne-Ar compositions were determined in diamonds from the Argyle lamproite, Western Australia, to assess whether subducted material affects the noble gas budget and composition of stable old sub-continental lithospheric mantle (SCLM). Twenty diamonds (both peridotitic and eclogitic) were characterized for their carbon isotopic compositions and N abundance and aggregation from which 10 eclogitic growth zones and 5 peridotitic growth zones were analysed for their He-Ne-Ar compositions. The eclogitic diamonds have ?13C values of ?4.7 to ?16.6‰ indicating a subduction signature, whereas the peridotitic diamonds have mantle-like compositions of ?4.0 to ?7.8‰. Mantle residence temperatures based on N-in-diamond thermometry showed that the eclogitic diamonds were mainly formed at 1260-1270?°C or above 1300?°C near the base of the lithosphere, whereas the peridotitic diamonds generally formed at lower temperatures (mostly 1135-1230?°C). A noble gas subduction signature is present to various extents in the eclogitic diamonds and is inferred from a hyperbolic mixing relationship between R/Ra and 4He and ?13C values concentrations with a predominance of low R/Ra values (<0.5; R/Ra?=?3He/4Hesample/3He/4Heair). In addition, low 40Ar/4He and 40Ar/36Ar ratios, high nucleogenic 21Ne/4He and low 3He/22Ne ratios are characteristic of subducted material and were found in the eclogitic diamonds. The peridotitic diamonds show generally higher R/Ra values (median 1.1?±?1.1) and lower 4He/40Ar ratios compared to eclogitic diamonds (median 0.1?±?0.8 R/Ra; with 7/10 samples having an average of 0.13?±?0.14 R/Ra). The studied peridotitic diamond growth zones showed a negative correlation between R/Ra and 4He concentrations over 2 orders of magnitude and limited variation in 3He, that can be largely explained by radiogenic 4He ingrowth. At low 4He concentrations the R/Ra value is around 2.8 for both paragenesis of diamonds and is significantly lower than present-day SCLM values, suggesting (1) a more radiogenic helium isotope composition beneath the Halls Creek Orogen than those for typical SCLM from other cratons and/or (2) that the peridotitic diamonds are formed from fluids that also had a subduction input. The high mantle residence temperature and low R/Ra value in the core and low temperature and higher R/Ra value in the rim of a single peridotitic diamond indicate multiple growth events and that part of the lherzolitic diamond population may be genetically related to the eclogitic diamonds. Combining the diamond mantle residence temperatures with noble gas compositions shows that noble gas subduction signatures are present at the base of the lithosphere below 180?km depth beneath Argyle and that fluid migration and interaction with the SCLM occurred over scales of at least 15?km, between 180 and 165?km depth.
DS201909-2098
2019
Burnham, A.D.Timmerman, S., Honda, M., Burnham, A.D., Amelin, Y., Woodland, S., Pearson, D.G., Jaques, A.L., Le Losq, C., Bennett, V.C., Bulanova, G.P., Smith, C.B., Harris, J.W., Tohver, E.Primordial and recycled helium isotope signatures in the mantle transition zone. Science, Vol. 365, 6454, pp. 692-694.Mantlediamond genesis

Abstract: Isotope compositions of basalts provide information about the chemical reservoirs in Earth’s interior and play a critical role in defining models of Earth’s structure. However, the helium isotope signature of the mantle below depths of a few hundred kilometers has been difficult to measure directly. This information is a vital baseline for understanding helium isotopes in erupted basalts. We measured He-Sr-Pb isotope ratios in superdeep diamond fluid inclusions from the transition zone (depth of 410 to 660 kilometers) unaffected by degassing and shallow crustal contamination. We found extreme He-C-Pb-Sr isotope variability, with high 3He/4He ratios related to higher helium concentrations. This indicates that a less degassed, high-3He/4He deep mantle source infiltrates the transition zone, where it interacts with recycled material, creating the diverse compositions recorded in ocean island basalts.
DS201912-2825
2020
Burnham, A.D.Shirey, S.B., Smit, K.V., Pearson, D.G., Walter, M.J., Aulbach, S., Brenker, F.E., Bureau, H., Burnham, A.D., Cartigny, P., Chacko, T., Frost, D.J., Hauri, E.H., Jacob, D.E., Jacobsen, S.D., Kohn, S.C., Luth, R.W., Mikhail, S., Navon, O., Nestola, F., NimDiamonds and the mantle geodynamics of carbon: deep mantle carbon and evolution from the diamond record.IN: Deep carbon: past to present, Orcutt, Daniel, Dasgupta eds., pp. 89-128.Mantlegeodynamics

Abstract: The science of studying diamond inclusions for understanding Earth history has developed significantly over the past decades, with new instrumentation and techniques applied to diamond sample archives revealing the stories contained within diamond inclusions. This chapter reviews what diamonds can tell us about the deep carbon cycle over the course of Earth’s history. It reviews how the geochemistry of diamonds and their inclusions inform us about the deep carbon cycle, the origin of the diamonds in Earth’s mantle, and the evolution of diamonds through time.
DS202001-0039
2020
Burnham, A.D.Shirey, S.B., Smit, K.V., Pearson, D.G., Walter, M.J., Aulbach, S., Brenker, F.E., Bureau, H., Burnham, A.D., Cartigny, P., Chacko, T., Frost, D.J., Hauri, E.H., Jacob, D.E., Jacobsen, S.D., Kohn, S.C., Luth, R.W., Mikhail, S., Navon, O., Nestola, F., NimDiamonds and mantle geodynamics of carbon: IN: Deep Carbon: past to present. Editors Orcutt, Danielle, Dasgupta, pp. 89-128.Mantlegeodynamics

Abstract: The science of studying diamond inclusions for understanding Earth history has developed significantly over the past decades, with new instrumentation and techniques applied to diamond sample archives revealing the stories contained within diamond inclusions. This chapter reviews what diamonds can tell us about the deep carbon cycle over the course of Earth’s history. It reviews how the geochemistry of diamonds and their inclusions inform us about the deep carbon cycle, the origin of the diamonds in Earth’s mantle, and the evolution of diamonds through time.
DS202107-1128
2019
Burnham, A.D.Shirey, S.B., Smit, K.V., Pearson, D.G., Walter, M.J., Aulbach, S., Brenker, F.E., Bureau, H., Burnham, A.D., Cartigny, P., Chacko, T., Frost, D.J., Hauri, E.H., Jacob, D.E., Jacobsen, S.D., Kohn, S.C., Luth, R.W., Mikhail, S., Navon, O.. Nestola, F., NimDiamonds and mantle geodynamics of carbon.Deep Carbon - Cambridge University Press , Cambridge.org 40p. PdfMantlecarbon
DS1986-0649
1986
Burnham, C.W.Post, J.E., Burnham, C.W.Modeling tunnel cation displacements in Hollandites using structureenergy calculationsAmerican Mineralogist, Vol. 71, pp. 1178-1185GlobalPriderite, Mineralogy
DS1998-0191
1998
Burnham, O.M.Burnham, O.M., et al.The petrogenesis of the eastern Pyrenean peridotites: an integrated studyof their whole rock geochemistry and Re Os isotope composition.Geochimica et Cosmochimica Acta, Vol. 62, No. 13, pp. 2293-2310.FrancePeridotites
DS1860-0495
1886
Burnham, S.M.Burnham, S.M.Precious Stones in Nature, Art and LiteratureBoston: Bradley Whidden., 400P.GlobalGemology
DS201012-0064
2009
Burnistrov, A.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
DS200812-0162
2008
Burnistrov, A.A.A.A.Burnistrov, A.A.A.A., Staostin, V.A.I.A., Sakya, D.A.R.A.Tectonic aspects of the evolution of ore potential of carbonatite and kimberlite magmatism.Doklady Earth Sciences, Vol. 418, 1, pp. 19-23.MantleMagmatism
DS1989-0538
1989
Burnley, P.C.Green, H.W., Burnley, P.C.A new self organizing mechanism for deep focus earthquakesNature, Vol. 341, October 26, pp. 733-737. Database #18212GlobalMantle, Model -earthquakes
DS1995-0243
1995
Burnley, P.C.Burnley, P.C.The fate of olivine in subducting slabs: a reconnaissance studyAmerican Mineralogist, Vol. 80, No. 11-12, Nov. Dec. pp. 1293-01GlobalPetrology -experimental, Subduction
DS201808-1756
2018
Burnley, P.C.Kaboli, S., Burnley, P.C.Direct observations of crystal defects in polycrystalline diamond. CVDMaterials Characterization, Vol. 142, pp. 154-161.Globalsynthetics

Abstract: Crystal defects are abundant in synthetic diamond produced by chemical vapor deposition (CVD). We present the first images of crystal defects in a bulk polycrystalline CVD diamond sample using general electron channeling contrast imaging (ECCI) in a field emission scanning electron microscope (FE-SEM). For enhancement of channeling contrast of this material, we introduce a novel protocol for diamond surface preparation that involves acid etching. Using this protocol, we imaged three types of crystal defects including twins, stacking faults and dislocations. Each defect was identified based on its appearance in electron channeling contrast (ECC) micrographs. We analyzed grains containing twins and dislocations using electron backscatter diffraction (EBSD) crystal orientation mapping. We found a large population of grains that contained ?3 type twins on {111} planes with a 60°?111? angle-axis pair of misorientation for twin boundaries. In addition, we identified {111} stacking faults and {111} helical dislocations. These observations are in agreement with reports of crystal defects in CVD diamond thin foils studied by a transmission electron microscope (TEM).
DS202205-0679
2022
Burnley, P.C.Dutta, R., Tracy, S.J., Cohen, R.E. , Miozzi, F., Luo, K., Yang, J., Burnley, P.C., Smith, D., Meng, Y., Chariton, S., Prakapenka, V.B., Duffy, T.S.Ultrahigh-presssure disordered eight-coordinated phase of Mg2GeO4: analogue for super Earth mantles. GermaniumPNAS, https://doi.org/10.1073/pnas.2114424119Mantlegeodynamics

Abstract: Mg2GeO4 is important as an analog for the ultrahigh-pressure behavior of Mg2SiO4, a major component of planetary interiors. In this study, we have investigated magnesium germanate to 275 GPa and over 2,000 K using a laser-heated diamond anvil cell combined with in situ synchrotron X-ray diffraction and density functional theory (DFT) computations. The experimental results are consistent with the formation of a phase with disordered Mg and Ge, in which germanium adopts eightfold coordination with oxygen: the cubic, Th3P4-type structure. DFT computations suggest partial Mg-Ge order, resulting in a tetragonal I4¯2d structure indistinguishable from I4¯3d Th3P4 in our experiments. If applicable to silicates, the formation of this highly coordinated and intrinsically disordered phase may have important implications for the interior mineralogy of large, rocky extrasolar planets.
DS1988-0714
1988
BurnsTzeng, Y., Kung, P.J., Zee, R., Legg, K., Solnick-Legg, H., BurnsSpiral hollow cathode plasma assisted diamond depositionAppl. Phys. Letters, Vol. 53, No. 23, pp. 2326-2327GlobalDiamond coatings, Diamond applications
DS2001-0551
2001
BurnsJordan, T.E., Burns, Veiga, Pangaro. Copeland, MpodozisExtension and basin formation in the southern Andes caused by increased convergence rate: a mid-Cenozoic...Tectonics, Vol. 20, No. 3, June, pp. 308-24.AndesTectonics - not specific to diamonds
DS201910-2269
2018
Burns, A.J.Kavanagh, J.L., Burns, A.J., Hilmi Hazim, S., Wood, E.P., Martin, S.A., Hignett, S., Dennis, D.J.C.Challenging dyke ascent models using novel laboratory experiments: implications for reinterpreting evidence of magma accent and volcanism.Journal of Volcanology and Geothermal Research, Vol. 354, pp. 87-101.Mantlemagmatism

Abstract: Volcanic eruptions are fed by plumbing systems that transport magma from its source to the surface, mostly fed by dykes. Here we present laboratory experiments that model dyke ascent to eruption using a tank filled with a crust analogue (gelatine, which is transparent and elastic) that is injected from below by a magma analogue (dyed water). This novel experimental setup allows, for the first time, the simultaneous measurement of fluid flow, sub-surface and surface deformation during dyke ascent. During injection, a penny-shaped fluid-filled crack is formed, intrudes, and traverses the gelatine slab vertically to then erupt at the surface. Polarised light shows the internal stress evolution as the dyke ascends, and an overhead laser scanner measures the surface elevation change in the lead-up to dyke eruption. Fluorescent passive-tracer particles that are illuminated by a laser sheet are monitored, and the intruding fluid's flow dynamics and gelatine's sub-surface strain evolution is measured using particle image velocimetry and digital image correlation, respectively. We identify 4 previously undescribed stages of dyke ascent. Stage 1, early dyke growth: the initial dyke grows from the source, and two fluid jets circulate as the penny-shaped crack is formed. Stage 2, pseudo-steady dyke growth: characterised by the development of a rapidly uprising, central, single pseudo-steady fluid jet, as the dyke grows equally in length and width, and the fluid down-wells at the dyke margin. Sub-surface host strain is localised at the head region and the tail of the dyke is largely static. Stage 3, pre-eruption unsteady dyke growth: an instability in the fluid flow appears as the central fluid jet meanders, the dyke tip accelerates towards the surface and the tail thins. Surface deformation is only detected in the immediate lead-up to eruption and is characterised by an overall topographic increase, with axis-symmetric topographic highs developed above the dyke tip. Stage 4 is the onset of eruption, when fluid flow is projected outwards and focused towards the erupting fissure as the dyke closes. A simultaneous and abrupt decrease in sub-surface strain occurs as the fluid pressure is released. Our results provide a comprehensive physical framework upon which to interpret evidence of dyke ascent in nature, and suggest dyke ascent models need to be re-evaluated to account for coupled intrusive and extrusive processes and improve the recognition of monitoring signals that lead to volcanic eruptions in nature.
DS2000-0305
2000
Burns, I.M.Friend, C.L., Jones, K.A., Burns, I.M.New high pressure granulite event in the Moine Supergroup, northern Scotland: implications Taconic...Geology, Vol. 28, No. 6, June pp. 543-6.ScotlandTectonics - Caledonian crustal evolution, high pressure
DS2000-1044
2000
Burns, J.A.Young, R.A., Burns, J.A., Sjogren, D.B., Kvill, D.Post glacial terraces of West Central Alberta and inferences models of subglacial and deglacial processesGeological Society of America (GSA) Abstracts, Vol. 32, No. 7, p.A-511.AlbertaGeomorphology
DS1970-0761
1973
Burns, L.K.Mccallum, M.E., Eggler, D.H., Burns, L.K.Kimberlitic Diatremes in Northern Colorado and Southern Wyoming #1International Kimberlite Conference FIRST EXTENDED ABSTRACT VOLUME., PP. 217-220.United States, Colorado, Wyoming, State Line, Rocky MountainsBlank
DS1970-0958
1974
Burns, L.K.Mccallum, M.E., Eggler, D.H., Burns, L.K.Colorado Wyoming Kimberlitic Diatremes: Pt. I, General Geology and Petrography.Geological Society of America (GSA), Vol. 6, No. 5, P. 457, (abstract.).United States, Colorado, Wyoming, State Line, Rocky MountainsBlank
DS1975-0131
1975
Burns, L.K.Mccallum, M.E., Eggler, D.H., Burns, L.K.Kimberlitic Diatremes in Northern Colorado and Southern Wyoming #2Physics and Chemistry of the Earth, Vol. 9, PP. 149-161.United States, Colorado, Wyoming, State Line, Rocky MountainsBlank
DS1975-0132
1975
Burns, L.K.Mccallum, M.E., Smith, C.B., Burns, L.K., Eggler, D.H., Braddoc.Kimberlite Diatremes and Others Iron Mountain Area, Laramierange, Wyoming.Geological Society of America (GSA), Vol. 7, No. 5, P. 628 (abstract.).United States, Wyoming, State Line, Rocky MountainsBlank
DS200812-0195
2008
Burns, P.C.Chakhmouradian, A.R., Mitchell, R.H., Burns, P.C., Mikhailova, Yu., Reguir, E.P.Marianoite, a new member of the cuspidine group from the Prairie Lake silicocarbonatite.Canadian Mineralogist, Vol. 46, 4, August pp.Canada, OntarioCarbonatite
DS1988-0495
1988
Burns, R.C.Nam, Tom Leong, Burns, R.C., Keddy, R.J.Radiation detector from a mass of small diamond particlesPatent: S. African 87 06994 A June 29, 1988 16p. (De Beers), GlobalDiamond Application
DS201012-0081
2009
Burns, R.C.Burns, R.C., Chumakov, A.I., Connell, Dube, Godfried, Hansen, Hartwig, Hoszowska, Masiello, Mkonza, RebakHPHT growth and x-ray characterization of the high quality type IIa diamond.Journal of Physics Condensed Matter, Vol. 21, 36, pp. 364224-364237.TechnologyType II a
DS1990-0853
1990
Burollet, P.F.Kogbe, C.A., Burollet, P.F.A review of continental sediments in AfricaJournal of African Earth Sciences, Vol. 10, No. 1/2 pp. 1-26Africa, Central, WestTectonics, Continental complexes
DS1950-0321
1957
Burov, A.P.Bobrievitch, A.P., Burov, A.P.Diamonds of Siberia. Translation of Almazy Siberii, 1957London: Industrial Diamond Information Bureau, 219P.Russia, Siberia, YakutiaGeology
DS1960-0222
1962
Burov, A.P.Burov, A.P.How to Look for DiamondsGosgeoltekhizdat: Bibliotechka Iskatelya Poleznykk., 38P.RussiaProspecting, Kimberlite
DS1999-0249
1999
Burov, E.Gerbault, M., Burov, E., Daignieres, M.Do faults trigger folding in the lithosphere?Geophysical Research Letters, Vol. 26, No. 2, Jan. 15, pp. 271-74.MantleTectonics, Lithosphere
DS2001-0151
2001
Burov, E.Burov, E., Jolivet, L., LePourhiet, L., Poliakov, A.A thermomechanical model of exhumation of high pressure HP and ultra high pressure UHP metamorphic rocks...Tectonophysics, Vol. 342, No. 2, pp. 113-36.GlobalAlpine type collision belts, UHP
DS2003-0192
2003
Burov, E.Burov, E., Jaupart, C., Guillou-Frottier, L.Ascent and emplacement of bouyant magma bodies in brittle ductile upper crustJournal of Geophysical Research, Vol. 108, B4, April 1, DOI 10.1029/2002JB001904.MantleMagmatism - not specific to diamonds
DS200412-0249
2003
Burov, E.Burov, E., Jaupart, C., Guillou-Frottier, L.Ascent and emplacement of bouyant magma bodies in brittle ductile upper crust.Journal of Geophysical Research, Vol. 108, B4, April 1, DOI 10.1029/2002 JB001904.MantleMagmatism - not specific to diamonds
DS200512-0123
2005
Burov, E.Burov, E.Modeling plume head - continental lithosphere interaction using a tectonically realistic lithosphere.mantleplumes.org, 6p.MantleMantle plume
DS200512-0124
2005
Burov, E.Burov, E., Guillou-Frottier, L.The plume head continental lithosphere interaction using a technically realistic formulation for the lithosphere.Geophysical Journal International, Vol. 161, 2, pp. 469-490.MantleHotspots, plumes
DS200512-0125
2005
Burov, E.Burov, E., Guillou-Frottier, L.The plume head - continental lithosphere interaction using a tectonically realistic formulation for the lithosphere.Chapman Conference held in Scotland August 28-Sept. 1 2005, 1p. abstractMantleMantle plume
DS200712-0125
2007
Burov, E.Burov, E.,Guillou Frottier, L., Acremont, E., Le Pourthier, L., Cloetingh, S.Plume head lithosphere interactions near intra continental plate boundaries.Tectonophysics, Vol. 434, 1-4, pp. 15-38.MantleHotspots
DS200712-0126
2007
Burov, E.Burov, E., Toussaint, G.Surface processes and tectonics: forcing of continental subduction and deep processes.Global and Planetary Change, Vol. 58, 1-4, pp. 141-164.MantleSubduction
DS200712-0127
2007
Burov, E.Burov, E., Toussaint, G.Surface processes and tectonics: forcing of continental subduction and deep processes.Global and Planetary Change, Vol. 58, 1-4, pp. 141-164.MantleSubduction
DS200912-0090
2009
Burov, E.Burov, E., Cloetingh, S.Controls of mantle plumes and lithospheric folding on modes of intraplate continental tectonics: differences and similarities.Geophysical Journal International, Vol. 178, bo. 3 Sept. oo, 1691-1722.MantlePlume, hot spots
DS201112-0129
2011
Burov, E.Burov, E.Mechanisms of deep crustal subduction and exhumation: insights from numerical modelling.Goldschmidt Conference 2011, abstract p.601.Mantle, Alps, HimalayasRheology
DS201312-0112
2014
Burov, E.Burov, E., Francois, T., Yamato, P., Wolf, S.Mechanisms of continental subduction and exhumation of HP and UHP rocks.Gondwana Research, Vol. 25, pp. 464-493.MantleSubduction
DS201312-0166
2013
Burov, E.Cloetingh, S., Burov, E., Francois, T.Thermo-mechanical controls on intra-plate deformation and the role of plume folding interactions in continental topography.Gondwana Research, Vol. 24, 3-4, pp. 815-837.MantleHotspots
DS201312-0915
2013
Burov, E.Tirel, C., Brun, J-P, Burov, E., Wortel, M.J.R., Lebedev, S.A plate tectonics oddity: caterpillar walk exhumation of subducted continental crust.Geology, Vol. 41, 5, pp. 555-558.MantleSubduction
DS201412-0085
2014
Burov, E.Burov, E., Francois, T., Yamato, P., Wolf, S.Mechanisms of continental subduction and exhumation of HP and UHP rocks.Gondwana Research, Vol. 25, pp. 464-493.MantleSubduction, Eclogites
DS201506-0282
2015
Burov, E.Koptev, A., Calais, E., Burov, E., Leroy, S., Gerya, T.Dual continental rift systems generated by plume-lithosphere interaction. Central East African RiftNature Geoscience, Vol. 8, pp. 388-392.AfricaMagmatism
DS201606-1103
2016
Burov, E.Lavecchia, A., Clark, S.A., Beekman, F., Cloetingh, S.A.P.L., Burov, E.Thermal perturbation, mineral assemblages and rheology variations by dyke emplacement in the crust.Tectonics, in press availableMantleBasaltic dykes, two layered continental crust

Abstract: We constructed a thermomechanical model to examine the changes in rheology caused by the periodic intrusion of basaltic dykes in a two-layered continental crust. Dyke intrusion can locally change the mineralogical composition of the crust in space and time as a result of temperature-induced metamorphism. In our models we paid particular attention to determine how different mineral assemblages and reaction kinetics during metamorphism impact on the thermomechanical behavior of the crust, in terms of differential stress values. We investigated several lithologies characteristic for intracontinental crust: (1) a quartz-feldspathic crust (QF), (2) a crust with a mineralogical assemblage resembling the average chemical composition occurring in literature (CC), and (3) a micaschist crust (MS). Our model shows that temperature profiles are weakly influenced by metamorphism, with negligible variations in the T-t paths. The results indicate that intrusion-induced changes in the crustal rheology are strongly dependent on mineralogical assemblage variation. The strength of a dyke aureole in the upper crust increases during dyke emplacement, which may cause migration of later dykes and influence the dyke spacing. In contrast, in the lower crust the strength of a dyke aureole decreases during dyke emplacement. Fast kinetics results in a ductile lower crust in proximity of the dykes, whereas slower kinetics leads to the formation of partial melts and subsequent switch from ductile to brittle behavior. Lithology exerts a dominant role on the quantity of melt produced, with higher volume percentages occurring in the MS case study. Produced melts may migrate and support acidic volcanic activity.
DS2003-0193
2003
Burov, E.B.Burov, E.B.The upper crust is softer than dry quartziteTectonophysics, Vol. 361, 3-4, pp. 321-6.MantlePetrology
DS2003-0305
2003
Burov, E.B.D'Acremont, E., Leroy, S., Burov, E.B.Numerical modelling of a mantle plume: the plume head lithosphere interaction in theEarth and Planetary Science Letters, Vol. 206, No. 3-4, pp. 379-396.MantleModel - plume
DS201012-0082
2010
Burov, E.B.Burov, E.B.The equivalent elastic thickness (Te) seismicity and the long term rheology of continental lithosphere: time to burn out 'creme brulee?' insights from large scale geodynamic modeling.Tectonophysics, Vol. 484, pp. 4-26.MantleGeodynamics
DS200612-0649
2006
Burr, G.S.Jull, A.J.T., Burr, G.S.Accelerator mass spectrometry: is the future bigger or smaller?Earth and Planetary Science Letters, Vol. 243, 3-4, March 30, pp. 305-325.TechnologySpectrometry
DS1992-1494
1992
BurraSubrahmanyam, BurraOn the role of different gravity station intervals in the elucidation of structures and tectonics of Peninsular India.Indian Minerals, Vol. 46, No. 3-4, pp. 337-346.IndiaGeophysics -gravity, Tectonics
DS1991-0198
1991
Burra Subrahmanyam, B.Burra Subrahmanyam, B., Subba Rao, J.A.V.R.K., Rao, H.V.Three probable locations for kimberlites in Wajrakarur -Lattavaram -P.C.Pyapilli area, Andhra PradeshJournal of Geological Society India, Vol. 37, May pp. 443-451IndiaKimberlite, Geophysics -gravity
DS200712-0128
2007
Burrell, B.Burrell, B.Namdeb - there is life yet in this hundred year old placer deposit.PDAC 2007, Abstract, 1p.Africa, NamibiaHistory
DS1996-0199
1996
Burrett, C.Burrett, C.Chinese terranes in Rodinia and greater GondwanaGeological Society of Australia 13th. Convention held Feb., No. 41, abstracts p.72.ChinaTectonics, Gondwanaland
DS1996-0200
1996
Burrett, C.Burrett, C., Berry, R.Chinese terranes in Rodinia and greater GondwanaGeological Society of Australia 13th. held Feb, No. 41, abstracts p. 72ChinaTectonics, Gondwanaland
DS1970-0043
1970
Burridge, A.D.Burridge, A.D.Microscope on PerformanceJohannesburg: De Beers Mining Res. Lab., 39P.South AfricaMineralogy, Petrography
DS1992-0191
1992
Burrough, P.A.Burrough, P.A.Are GIS structures too simple minded?Computers and Geosciences, Vol. 18, No. 4, pp. 395-400GlobalComputers, Programs -Geographic information systems -structure
DS1991-1530
1991
Burroughs, R.K.Schwieg, E.S., Vanarsdale, R.B., Burroughs, R.K.Subsurface structure in the vicinity of an intraplate earthquake swarm, central ArkansawTectonophysics, Vol. 186, No. 1-2, February 1, pp. 107-114ArkansasBlank
DS201012-0172
2010
Burrows, D.Dransfield, M., Le Roux, T., Burrows, D.Airborne gravimetry and gravity gradiometry at Fugro airborne surveys.Australian Airborne Gravity Conference Extended Abstracts 2010, pp. 49-52.Canada, Northwest TerritoriesGeophysics - gravity, Ekati
DS1993-1552
1993
Burrows, D.R.Sutcliffe, R.H., Barrie, C.T., Burrows, D.R., Beakhouse, G.P.Plutonism in the southern Abitibi Subprovince: a tectonics and petrogeneticframeworkEconomic Geology, Vol. 88, No. 6, September-October pp. 1359-1375Ontario, QuebecAbitibi Subprovince, Tectonics
DS1994-1696
1994
Burry, B.Stewart, G., Burry, B.DHK Resources -Northwest Territories diamond project, Lac de Gras area-Kennecott/DHK joint venture.The Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Section Meeting Oct. 12, Vancouver, p. 64. abstractNorthwest TerritoriesNews item, DHK Resources
DS1998-1355
1998
Bursey, T.Skelton, D., Bursey, T.Metallic and industrial mineral assessment report on the Buffalo Hills properties.Alberta Geological Survey, MIN 19980015AlbertaExploration - assessment, Ashton Mining of Canada, AEC.
DS1999-0674
1999
Bursey, T.Skelton, D., Bursey, T.Metallic and industrial mineral assessment report on the diamond exploration in the buffalo Head Hills area.Alberta Geological Survey, MIN 199900011, 897p. 253 maps.AlbertaExploration - assessment, Ashton Mining of Canada Inc.
DS1998-1387
1998
Bursik, Carey. GilbertSparks, R.S.J., Bursik, Carey. Gilbert, GlazeVolcanic plumesJohn Wiley, 570pGlobalBook - table of contents, volcanism, fluid dynamics, eruptions
DS1995-1847
1995
Bursik, M.Sugioka, I., Bursik, M.Explosive fragmentation of erupting magmaNature, Vol. 373, No. 6516, Feb. 23, pp. 689-691.GlobalMagma, Breccia -explosive crater
DS1995-1848
1995
Bursik, M.Sugioka, I., Bursik, M.Explosive fragmentation of erupting magmasNature, Vol. 373, No. 6516, Feb. 23, p. 689-691GlobalVolcanology, Magma, pipes not specific to diamonds
DS1981-0105
1981
Bursill, L.A.Bursill, L.A., Egerton, R.F., Thomas, J.M., Pennycook, S.High Resolution Imaging and Electron Energy Loss Studies Of platelet Defects in Diamond.Faraday Transactions, 2ND. SERIES, Vol. 77, No. 8, PP. 1367-1373.GlobalDiamond, Natural
DS1983-0161
1983
Bursill, L.A.Bursill, L.A.Small and Extended Defect Structures in Gem Quality Type 1 Diamonds.Endeavour., Vol. 7, No. 2, PP. 70-77.GlobalDiamond Structure, Crystallography
DS1983-0162
1983
Bursill, L.A.Bursill, L.A.Small and Extended Defect Structures in Gem Quality Type I Diamonds.Endeavour., Vol. 7, No. 2, PP. 70-78.GlobalMorphology, Mineralogy, Crystallography
DS1985-0050
1985
Bursill, L.A.Barry, J.C., Bursill, L.A., Hutchison, J.L.On the Structure of (100) Platelet Defects in Type 1a DiamonPhilosphical Magazine., Vol. 51, No. 1, JANUARY PP. 15-50.GlobalDiamond Research
DS1985-0099
1985
Bursill, L.A.Bursill, L.A., Glaisher, R.W.Aggregation and dissolution of small and extended defect structures in type IA diamondAmerican Mineralogist, Vol. 70, No. 5-6, pp. 608-618GlobalDiamond Morphology
DS1985-0100
1985
Bursill, L.A.Bursill, L.A., Glaisher, R.W.Aggregation and Dissolution of Small and Extended Defect Structures in Type 1a Diamond.American Mineralogist., Vol. 70, No. 5/6, PP. 608-618.GlobalNitrogen, Diamond Morphology, Diagrams
DS1989-0193
1989
Bursnall, J.T.Bursnall, J.T.Structural sequence from the southeastern part of the Kapuskasing structural zone in the vicinity of Ivan hoe Lake,OntarioGeological Survey of Canada Current Research, Paper No. 89-lC, pp. 405-411Ontario, MidcontinentStructure, Ivanhoe Lake
DS1989-0194
1989
Bursnall, J.T.Bursnall, J.T., Moser, D.Site survey for continental drilling in the Kapuskasing structural zoneOntario Geological Survey miscellaneous Paper, No. 146, pp. 16-21OntarioTectonics, Kapuskasing rift zone
DS1990-0257
1990
Bursnall, J.T.Bursnall, J.T.Deformation sequence in the southeastern Kapuskasing structural zone, Ivan hoe Lake Ontario, CanadaExposed cross sections of the Continental Crust, ed. M.H. Salisbury and, pp. 469-484OntarioKapuskasing zone, Tectonics
DS1991-0199
1991
Bursnall, J.T.Bursnall, J.T.A l:250, 000 lithological/structural compilation map of the KapuskasingUpliftGeological Association of Canada (GAC)/Mineralogical Association of Canada/Society Economic, Vol. 16, Abstract program p. A18OntarioTectonics -map, Kapuskasing Uplift
DS1991-1329
1991
Bursnall, J.T.Percival, J.A., Bursnall, J.T., Moser, D.E., Shaw, D.M.Site survey for the Canadian Continental Drilling Program Pilot Project In the Kapuskasing UpliftOntario Geological Survey Open File, Open File No. 5790, 34pOntarioDrilling, Kapuskasing structural zone
DS1991-1330
1991
Bursnall, J.T.Percival, J.A., Bursnall, J.T., Moser, D.E., Shaw, D.M.Site survey for the Canadian Continental Drilling Program's Pilot Projectin the Kapuskasing UpliftOntario Geological Survey Open File, Open File No. 5790, 34pOntarioDrilling, Kapuskasing Structural Zone
DS1994-0238
1994
Bursnall, J.T.Bursnall, J.T., et al.Structural correlation within the Kapuskasing upliftCanadian Journal of Earth Sciences, Vol. 31, No. 7, July pp. 1081-1095.OntarioStructure, Tectonics -Kapuskasing uplift
DS201212-0012
2012
Burstedde, C.Alistic, L., Gurnis, M., Stadler, G., Burstedde, C., Ghattas, O.Multi scale dynamics and rheology of mantle flow with plates.Journal of Geophysical Research, Vol. 117, B10 B10402MantleTectonics
DS201312-0113
2013
Burstedde, C.Burstedde, C., Stadler,G., Alisic, L., Wilcox, L.C., Tan, E.,Gurnis, M., Ghattas, O.Large scale adaptive mantle convection simulation.Geophysical Journal International, Vol. 192, no. 3, pp. 889-906.MantleConvection
DS1991-0123
1991
Burston, M.W.Bishop, P.K., Burston, M.W., Tong Chen, Lerner, D.N.A low cost dedicated multi-level groundwater sampling systemQuart. Journal of Engineering Geology, Vol. 24, pp. 311-324GlobalGroundwater, Sampling
DS2003-0194
2003
Burt, A.K.Burt, A.K., Hamilton, S.M.Comparison of selective leach signatures over kimberlites, carbonatites, false anomaliesOntario Geological Survey Open File, No. 6120, pp. 42 1-10.OntarioGeochemistry - kimberlites
DS200412-0250
2003
Burt, A.K.Burt, A.K., Hamilton, S.M.Comparison of selective leach signatures over kimberlites, carbonatites, false anomalies and blind targets.Ontario Geological Survey Open File, No. 6120, pp. 42 1-10.Canada, OntarioGeochemistry - kimberlites
DS200512-0126
2004
Burt, A.K.Burt, A.K., Hamilton, S.M.A comparison of selective leach signatures over kimberlites and other targets. B30,A4,A1.AM47,95-2,MR6, Seed, OPAP, Peddie carbonatites Firstbrook, Borden, Firesand,Ontario Geological Survey Open File, No. 6142, 179p. $ 16.Canada, Ontario, Kirkland Lake, New Liskeard, WawaGeochemistry
DS200612-0888
2006
Burt, A.K.McClenaghan, M.B., Hamilton, S.M., Hall, G.E.M., Burt, A.K., Kjarsgaard, B.A.Selective leach geochemistry of soils overlying the 95-2, B30 and A4 kimberlites, northeast Ontario.Geological Survey of Canada Open File, OF 5069, 28p. $ 9.00Canada, OntarioGeochemistry
DS1991-0200
1991
Burt, D.M.Burt, D.M.MetallogenesisInternational Union of Geodesy and Geophysics, 20th. meeting held Vienna August, pp. 542-553GlobalMetallogenesis, Overview -review paper
DS1994-0696
1994
Burt, D.M.Haggerty, S.E., Fung, A.T., Burt, D.M.Apatite, phosphorous and titanium in eclogitic garnet from the uppermantle.Geophysical Research Letters, Vol. 21, No. 16, Aug. 1, pp. 1699-1702.MantleEclogites
DS1993-1426
1993
Burtman, V.S.Sengor, A.M., Natalin, B.A., Burtman, V.S.Evolution of the Altaid tectonic collage and Paleozoic crustal growth inEurasiaNature, Vol. 364, July 22, pp. 299-306AsiaAngaran Craton, Plate tectonics
DS1998-1594
1998
BurtonWu, 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
DS1860-0080
1869
Burton, A.F.Burton, A.F.Explorations of the Highlands of the Brasil. Vol. IINew York: Greenwood Press, CHAPTER 6, PP. 72-93, BAHIAN; PERNAMBUCO; ALAGOAS CHAPTER 7, PSouth America, BrazilDiamond Occurrence
DS1900-0537
1907
Burton, A.R.E.Burton, A.R.E.Cape Colony TodayCape Town:, Africa, South AfricaHistory, Politics, Kimberley
DS2003-0616
2003
Burton, B.R.Ibinger, P.D., Watkins, J.M., Burton, B.R.The character of Cordileran magmatism in the Eocene, insights from the SweetgrassGeological Association of Canada Annual Meeting, Abstract onlyMontanaMagmatism - alkaline
DS200412-0865
2003
Burton, B.R.Ibinger, P.D., Watkins, J.M., Burton, B.R.The character of Cordilleran magmatism in the Eocene, insights from the Sweetgrass Hills, Mt.Geological Association of Canada Annual Meeting, Abstract onlyUnited States, MontanaMagmatism - alkaline
DS201112-0522
2011
Burton, D.Klaudis, J., Symons, G., Burton, D., Brauch, K.The application of airborne, ground and borehole geophysics to the exploration of the Lofdal carbonatite complex.Peralk-Carb 2011, workshop held Tubingen Germany June 16-18, PosterAfrica, NamibiaCarbonatite
DS1990-0946
1990
Burton, E.M.Lofty, G.J., Hillier, J.A., Burton, E.M., Cooke, S.A., Glaves, H.M.Diamond. Production, Exports, importsBritish Geological Survey World Mineral Statistics, 1984-1988, 6pGlobalDiamond production, Economics
DS1981-0106
1981
Burton, J.Burton, J.If a Mineral Has Not Been Vigourously Sought It Is Not Logical to Argue that the Mineral Is Rare.California The Mining Journal, Vol. 50, No. 10, PP. 4-7.United States, California, Colorado, Wyoming, Rocky Mountains, West CoastBlank
DS200512-0127
2004
Burton, J.P.Burton, J.P., Fralick, P.Depositional placer accumulations in coarse grained alluvial braided river systems.Economic Geology, Vol. 98, August no. 5, pp. 995-1001.Canada, Alberta, OntarioGeomorphology, placers, indicator minerals
DS1992-0192
1992
Burton, K.W.Burton, K.W., O'Nions, R.K.The timing of mineral growth across a regional metamorphic sequenceNature, Vol. 357, No. 6375, May 21, pp. 235-237NorwayMetamorphism, mineralization, Mineral growth timing
DS2000-0123
2000
Burton, K.W.Burton, K.W., Capmas, F., Cohen, A.S.Resolving crystallization ages of Archean mafic-ultramafic rocks using theRe Os isotope systemsEarth and Planetary Science Letters, Vol.179, No.3-4, Jul.15, pp.453-68.GlobalPetrology, Geochronology
DS2000-0124
2000
Burton, K.W.Burton, K.W., Schiano, Birck, Allegre, Dawson, et al.The distribution and behaviour of rhenium and osmium amongst mantle minerals and the age of lithospheric...Earth and Planetary Science Letters, Vol.183, No.1-2, Nov.30, pp.93-106.TanzaniaGeochronology, Mineral chemistry
DS2002-0229
2002
Burton, K.W.Burton, K.W., Gannoun, Birck, Allegre, Schiano,AlardThe compatibility of rhenium and osmium in natural olivine and their behaviour during mantle melting...Earth and Planetary Science Letters, Vol.198,1-2,pp.63-76., Vol.198,1-2,pp.63-76.MantleMineralogy - olivine, Basalt genesis
DS2002-0230
2002
Burton, K.W.Burton, K.W., Gannoun, Birck, Allegre, Schiano,AlardThe compatibility of rhenium and osmium in natural olivine and their behaviour during mantle melting...Earth and Planetary Science Letters, Vol.198,1-2,pp.63-76., Vol.198,1-2,pp.63-76.MantleMineralogy - olivine, Basalt genesis
DS200512-0008
2005
Burton, K.W.Alard, O., Luguet, A., Pearson, N.J., Griffin, W.L., Lorand, J.P., Gannoun, A., Burton, K.W., O'Reilly, S.Y.In situ Os isotopes in abyssal peridotites bridge the isotopic gap between MORBS and their source mantle.Nature, Vol. 436, No. 7053, Aug. 18, pp. 1005-1108.MantleGeochronology
DS201112-0416
2011
Burton, K.W.Harvey, J., Dale, C.W., Gannoun, A., Burton, K.W.Osmium mass balance in peridotite and the effects of mantle derived sulphides on basalt petrogenesis.Geochimica et Cosmochimica Acta, Vol. 75, 9, pp. 5574-5596.United States, New Mexico, Colorado PlateauKilbourne
DS201212-0287
2012
Burton, K.W.Harvey, J., Yoshikawa, M., Hammond, S.J., Burton, K.W.Deciphering the trace element characteristics in Kilbourne Hole peridotite xenoliths: melt-rock interaction and metasomatism beneath the Rio Grande rift, SW USA.Journal of Petrology, Vol. 53, 8, pp. 1709-1742.United StatesXenoliths
DS201504-0199
2015
Burton, K.W.Gannoun, A., Burton, K.W., Barfod, D.N., Schiano, P., Vlastelic, I., Halliday, A.N.Resolving mantle and magmatic processes in basalts from the Cameroon volcanic line using the Re-Os isotopic system.Lithos, Vol. 224-5, pp. 1-12.Africa, CameroonAlkaline rocks, basalts
DS201709-2051
2017
Burton, K.W.Schweitzer, K.M., Luguet, A., Nowell, G.M., Burton, K.W.Highly siderophile element ( HSE) and Hf-Os isotope signatures of carbonatites.Goldschmidt Conference, abstract 1p.Globalcarbonatites

Abstract: Carbonatites are carbonate-rich and SiO2-poor magmas with a low viscosity and low melting temperature (see [1]) making them amongst the most mobile and unusual melts produced on Earth. They occur worldwide in a range of tectonic settings, including continental rift (e.g. Tanzania, Kaiserstuhl), oceanic intraplate (e.g. Cape Verde), convergent margins (e.g. Italy) and cratons (e.g. Canada), with eruption ages spanning from 3 Ga (3007 Ma Tupertalik, Greenland, [2]) to present day (Oldoinyo Lengai, Tanzania). Nevertheless, their genesis and source remain poorly understood and the subject of much debate. They are considered to be either products of direct low-degree partial melting of a carbonated mantle source, products of immiscible separation from a carbonated silicate melt or formed by fractional crystallisation from a carbonated alkalirich silicate melt (see [1] and references therein). In order to gain further insight into the genesis and mantle source of these unusual magmas, we will present the first combined HSE and Os-Hf isotope systematics on a suite of carbonatites representative of their large age span and compositional range (Ca, Mg, Fe and Na-rich).
DS201912-2805
2019
Burton, K.W.McCoy-West, A.J., Chowdhury, P., Burton, K.W., Sossi, P., Nowell, G,M., Fitton, J.G., Kerr, A.C., Cawood, P.A., Williams, H.M.Extensive crustal extraction in Earth's early history inferred from molybdenum isotopes.Nature Geoscience, Vol. 12, pp. 946-951.Mantlepicrites

Abstract: Estimates of the volume of the earliest crust based on zircon ages and radiogenic isotopes remain equivocal. Stable isotope systems, such as molybdenum, have the potential to provide further constraints but remain underused due to the lack of complementarity between mantle and crustal reservoirs. Here we present molybdenum isotope data for Archaean komatiites and Phanerozoic komatiites and picrites and demonstrate that their mantle sources all possess subchondritic signatures complementary to the superchondritic continental crust. These results confirm that the present-day degree of mantle depletion was achieved by 3.5 billion years ago and that Earth has been in a steady state with respect to molybdenum recycling. Mass balance modelling shows that this early mantle depletion requires the extraction of a far greater volume of mafic-dominated protocrust than previously thought, more than twice the volume of the continental crust today, implying rapid crustal growth and destruction in the first billion years of Earth’s history.
DS200612-1230
2006
Burton, M.R.Sawyer, G.M., Burton, M.R.Effects of a volcanic plume on thermal imaging data.Geophysical Research Letters, Vol. 33, 14, L14311TechnologyGeothermometry
DS1860-0259
1876
Burton, R.Burton, R.The Nizam Diamond - the Diamond in IndiaQuarterly Journal of SCIENCE., N.S., Vol. 6, PP. 351-360.IndiaDiamonds Notable
DS1997-0148
1997
Burton, S.C.Burton, S.C.Outlook: the senior mining sectorInsight Press, Canada, GlobalEconomics, discoveries, Financing
DS201012-0168
2009
Burtseva, M.V.Doroshkevich, A.G., Viladar, S.G., Ripp, G.S., Burtseva, M.V.Hydrothermal REE mineralization in the Amba Dongar carbonatite complex, Gujarat, India.Canadian Mineralogist, Vol. 47, 5, pp. 1105-1116.IndiaCarbonatite
DS201312-0114
2013
Burtseva, M.V.Burtseva, M.V., Ripp, G.S., Doroshkevich, A.G., Viladkar, S.G., Varadan, R.Features of mineral and chemical composition of the Khamambettu carbonatites, Tamil, Nadu.Journal of the Geological Society of India, Vol. 81, 5, pp. 655-664.IndiaCarbonatite
DS201504-0186
2015
Burtseva, M.V.Burtseva, M.V., Ripp, G.S., Posokhov, V.F., Zyablitsev, A.Yu., Murzintseva, A.E.The sources of fluids for the formation of nephritic rocks of the southern folded belt of the Siberian craton.Doklady Earth Sciences, Vol. 460, 1, pp. 82-86.Russia, SiberiaAlkaline rocks, nephrites
DS2000-0103
2000
BurwashBouzidi, Y., Schmitt, Burwash, KanasewichCrustal thickness variations across AlbertaGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) 2000 Conference, 4p. abstractAlbertaGeophysics - seismics, Tectonics
DS2000-0118
2000
BurwashBuhlmann, A.L., Cavell, P., Burwash, Creaser, LuthMinette bodies and cognate mica-clinopyroxenite xenoliths from Milk River area - complex historyCanadian Journal of Earth Sciences, Vol.37, No.11, Nov.pp.1629-50.Alberta, southern, MontanaArchean Wyoming Craton, Milk River area - minettes
DS1992-0193
1992
Burwash, R.A.Burwash, R.A., Cavell, P.A.Xenoliths in ultrapotassic dykes on the Sweetgrass Arch, Alberta: evidence of a Mid-Proterozoic mantle MetasomatismGeological Society of America (GSA) Abstract Volume, Vol. 24, No. 6, May p. 5. abstract onlyAlbertaXenoliths, Ultrapotassic dykes, Sweetgrass
DS1993-0226
1993
Burwash, R.A.Cavell, P.A., Burwash, R.A., Nelson, D.B.Enriched mantle beneath southern Alberta: isotopic evidence for a northern extension of Wyoming Block.Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) Annual Meeting, p. 17, abstract.AlbertaGeochronology, Lamproite
DS1993-1092
1993
Burwash, R.A.Muehlenbachs, K., Burwash, R.A., Chacko, T.A major oxygen isotope anomaly in the basement rocks of AlbertaRoss: Alberta Basement Transects Workshop, #31, pp. 120-4.Alberta, Western CanadaGeochronology
DS1995-0226
1995
Burwash, R.A.Buhlmann, A.L., Cavell, P.A., Burwash, R.A., et al.Nature and origin of phlogopite-clinopyroxenite inclusions in Eoceneminettes in Milk River area.Geological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) Annual Meeting Abstracts, Vol. 20, p. A12 AbstractAlbertaMinettes
DS1996-0201
1996
Burwash, R.A.Burwash, R.A., et al.Paleozoic reactivation of Mid-Proterozoic Kimiwan structure Peace RiverArch, northwestern Alberta.Ross, G.M. Lithoprobe Alberta, No. 51, pp. 204-212.AlbertaStructure -faulting, Peace River Arch
DS1996-1000
1996
Burwash, R.A.Muehlenbachs, K., Chacko, T., Burwash, R.A.Low temperature, weathering overprint on the crystalline basement of the Kimiwan anomaly ... ratiosRoss, G.M. Lithoprobe Alberta, No. 51, pp. 199-203.AlbertaKimiwan anomaly
DS2000-0125
2000
Burwash, R.A.Burwash, 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
Burwash, R.A.Burwash, 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
DS2000-0127
2000
Burwash, R.A.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
DS2000-0128
2000
Burwash, R.A.Burwash, R.A., Krupicka, J., Wubrans, J.R.Metamorphic evolution of the Precambrian basement of AlbertaCan. Mineralog., Vol. 38, No. 2, Apr. pp. 423-34.AlbertaTectonics - metamorphism
DS2002-0195
2002
Burwash, R.A.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
Burwash, R.A.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
DS200812-0163
2008
Burwash, R.A.Burwash, R.A., Cavell, P., Simonetti, A., Chacko, T., Luth, R.W., Nelson, D.B.LA MC ICP MS dating of zircon using petrographic thin sections: an investigation of buried Archean basement in southern Alberta.Goldschmidt Conference 2008, Abstract p.A123.Canada, AlbertaGeochronology
DS201312-0130
2013
Burwash, R.A.Cavell, P., Burwash, R.A., Creaser, R.A., Luth, R.W.Minette bodies and cognate mica-clinopyroxenite xenoliths from the Milk River area, southern Alberta: records of a complex history of the northern most part of the Archean Wyoming craton.Canadian Journal of Earth Sciences, Vol. 37, 11, pp. 1629-1650.Canada, AlbertaMinette
DS1975-0046
1975
Burwell, A.D.M.Burwell, A.D.M.rubidium-strontium (Rb-Sr) ISOTOPE GEOCHEMISTRY of LHERZOLITES and THEIR CONSTITUENT MINERALS from VICTORIA, AUSTRALIA.Earth and Planetary Science Letters, Vol. 29, PP. 69-78.AustraliaKimberlite, Xenoliths, Basalt
DS201712-2722
2017
Buryak, S.Reyes, A.V., Wolfe, A.P., Tierney, J.E., Silver, P.A., Royer, D.L., Greenwood, D.R., Buryak, S., Davies, J.H.F.L.Paleoenvironmental research on early Cenozoic sediment fills in Lac de Gras kimberlite pipes: progress and prospects.45th. Annual Yellowknife Geoscience Forum, p. 65 abstractCanada, Northwest Territoriesdeposit - Giraffe

Abstract: Several Lac de Gras kimberlite pipes host thick accumulations of stratified post-eruptive lacustrine sediment and peat. Given the range of Lac de Gras kimberlite emplacement ages, these fills - though rare - provide a unique sedimentary archive of paleoenvironments during the sustained Early Cenozoic “greenhouse” interval, in a high-latitude region otherwise devoid of Phanerozoic sediment cover. Extensive exploration drilling has provided a valuable window into this unique sedimentary record, which would have otherwise remained covered by Quaternary glacial deposits. Our focus to date has been multidisciplinary study of the Giraffe pipe sediment fill: an ~80 m-thick sequence of post-eruptive lacustrine silt overlain by peat, which paints a remarkable picture of a humid-temperate Middle Eocene forest ecosystem on the Canadian Shield. Post-eruptive chronology is provided by interbedded distal tephra horizons, likely sourced from Alaska, that have been dated by glass fission-track and zircon U-Pb techniques. Paleoclimate proxies derived from pollen, wood cellulose oxygen isotopes, and biomarkers converge on reconstructed mean annual temperatures >17 °C warmer than present, with mean winter temperatures above freezing, and mean annual precipitation ~4x present. Two independent reconstructions of CO2 from well preserved conifer foliage suggest that this warming occurred under relatively modest atmospheric CO2 concentrations of 430-630 ppm. These findings provide direct field-based evidence for dramatic past arctic warming at CO2 concentrations that were well within the range of projections under “business-as-usual” emissions scenarios, underscoring the capacity for exceptional polar amplification of climate change under modest CO2 concentrations once both fast and slow feedbacks processes become expressed. Our studies at Giraffe pipe also highlight the scientific value of archived exploration drill core in the Lac de Gras kimberlite field, particularly with respect to pipes that are unremarkable for the purpose of diamond exploration.
DS201812-2787
2018
Buryak, S.Buryak, S., Reyes, A.V., Siver, P.A., Li, L., Dufrane, S.A.Bulk organic geochemistry and U-Pb zircon geochronology of the Wombat sedimentary fill.2018 Yellowknife Geoscience Forum , p. 98-99. abstractCanada, Northwest Territoriesdeposit - Wombat

Abstract: The Wombat locality (64.73°N, 110.59°W) is a diamondiferous kimberlite in the Lac de Gras kimberlite field of Northwest Territories. Two drill cores, CH 93-29 and DDH 0-005, intersect the Wombat crater facies and include 195 m of well preserved, undisturbed lake sediment fill. Bulk sediment elemental analysis, C isotope composition, and Rock-Eval pyrolysis, together with inferences from microfossils, are used to characterize conditions of sedimentation and paleoenvironment in the maar lake. Bulk sediment C/N, hydrogen index (HI), and ?13C indicate material derived from C3 land plants dominates the sedimentary organic matter, with a minor algal contribution. The ?13C values range from -25.3 ‰ to -30.2 ‰ (average -26.6 ‰) and are typical for C3 land plants, with fluctuations in ?13C likely related to shifts in the proportions of land-derived material and algal organic matter. An overall trend of higher ?13C towards the top of the core suggests increasing autochthonous organic matter production. 18 samples analyzed by Rock-Eval pyrolysis all plot in the Type III kerogen field for HI vs. Tmax,with average Tmax values ~425 °C indicative of the low thermal maturity of organic matter. Total organic carbon (TOC) averages 3.6 wt.% and average total carbonate content is 14.1 wt.%, indicating bottom water anoxia and substantial carbonate input from weathering of overlying carbonate cover rocks, respectively. Together with well-preserved freshwater microfossils (e.g. diatoms, chrysophytes, synurophytes), the results indicate deposition in a non-marine setting. The age of the Wombat maar lake sediments is determined using MC-LA-ICP-MS U-Pb zircon geochronology from two distal rhyolitic tephra beds found in the core DDH 0-005, yielding a date of 82.97±0.60 Ma (MSWD = 1.7, n=18 of 33 grains analyzed). This minimum age suggests that Wombat kimberlite pipe emplacement occurred during the Late Cretaceous, with sedimentation in the maar beginning shortly thereafter. Though our geochronology is preliminary at this point, our findings from the Wombat pipe post-eruptive lake sediment fill provide direct evidence for a non-marine environment in the Lac De Gras area during the Late Cretaceous. Furthermore, microfossils in the Wombat pipe sediment fill likely include the oldest-known occurrence of freshwater diatoms.
DS1990-0417
1990
Busbey, A.B.Donovan, R.N., Busbey, A.B., Morgan, K.M., Denison, R.E., LidiakSouthern midcontinent-Texas transect overviewGeological Society of America (GSA) Annual Meeting, Abstracts, Vol. 22, No. 7, p. A192GlobalGeochronology, Geophysics
DS1992-0883
1992
Busby, C.Kokelaar, P., Busby, C.Subaqueous explosive eruption and welding of pyroclastic depositsScience, Vol. 257, July 10, pp. 196-201CaliforniaMineral King metavolcanics, Volcanics
DS1995-0244
1995
Busby, C.J.Busby, C.J., et al.Tectonics of sedimentary basins - BookBlackwell Scientific, 356p. approx. $ 70.00GlobalBook -table of contents ad, Basins
DS1995-1254
1995
Busbym C.Miller, D.M., Busbym C.Jurassic magmatism and tectonics of the North America CordileraGeological Society of America Special Paper, No. 299, 432p. approx.; $ 100.00 United StatesCordilleraBook -ad, Jurassic magmatism
DS1988-0095
1988
Busby-Spera, C.J.Busby-Spera, C.J.Speculative tectonic model for the early Mesozoic arc of the southwest Cordilleran United StatesGeology, Vol. 16, No. 12, December pp. 1121-1125CordilleraTectonics, Structure-Mesozoic arc
DS202109-1472
2021
Busch, J.F.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.
DS1996-0202
1996
Busch, J.P.Busch, J.P., Essene, E.J., Van der Ploijm, B.A.Evolution of deep crustal normal faults: constraints from thermo barometry in the Grenville Orogen, OntarioTectonophysics, Vol. 265, No. 1/2, Nov. 5, pp. 83-100.OntarioTectonics, Thermobarometry
DS1983-0163
1983
Buschbach, T.C.Buschbach, T.C.New Madrid Seismotectonic Study: Summary of Activities From1977-1981.National Technical Information Service NUREG- CR 3173, 212P.GlobalMid-continent, Ouachita, Rough Creek Graben
DS1985-0586
1985
Buschbach, T.C.Sargent, M.L., Buschbach, T.C.Map of the Morphology of the Top of Precambrian Crystalline rocks in Illinois.Geological Society of America (GSA), Vol. 17, No. 5, MARCH P. 324. (abstract.).United States, Great Lakes, IllinoisBlank
DS1986-0117
1986
Buschbach, T.C.Buschbach, T.C.New Madrid seismotectonic ProgramNational Technical Information Service NUREG /CR 4632, NJune 86, 76pMidcontinentBlank
DS200712-0129
2006
Buscombe, D.Buscombe, D., Masselink, G.Concepts in gravel beach dynamics.Earth Science Reviews, Vol. 79, 1-2, Nov. pp. 32-52.TechnologyBeach - sorting not specific to diamonds
DS200812-0145
2008
Buse, B.Brown, R.J., Buse, B., Sparks, R.S.J., Field, M.On the welding of pyroclasts from very low viscosity magmas: examples from kimberlite volcanoes. Venetia K2, BK9 Damtshaa (Orapa)Journal of Geology, Vol. 117, pp. 354-374.Africa, South Africa, BotswanaClassification - coherent kimberlite
DS200912-0091
2009
Buse, B.Buse, B., Sparks, S.R., Field, M.Growth of Bultfonteinite and hydrogarnet in metasomatized basalt xenoliths in the BK9 kimberlite, Orapa, Botswana: insights and hydrothermal metamorphism in kimberlite pipes.GAC/MAC/AGU Meeting held May 23-27 Toronto, Abstract onlyAfrica, BotswanaDeposit - Orapa
DS201012-0083
2010
Buse, B.Buse, B., Schumacher, J.C., Sparks, R.S.J., Field, M.Growth of bultfontenite and hydrogarnet in metasomatized basalt xenoliths in the B/K9 kimberlite, Damtshaa: insights into hydrothermal metamorphism pipeContributions to Mineralogy and Petrology, Vol. 160, 4, pp. 533-550.Africa, BotswanaMetamorphism - BK9
DS201112-0130
2011
Buse, B.Buse, B., Sparks, R.S.J., Field, M., Schumacher, J.C., Chisi, K., Thaodi, T.Geology of the BK9 kimberlite ( Damtshaa, Botswana): implications for the formation of dark volcaniclastic kimberlite.Bulletin Volcanology, In press available, 17p.Africa, BotswanaGeology - Damtshaa
DS1982-0555
1982
Buseck, P.R.Self, P.G., Buseck, P.R.Tem Study of a New Ca-ti Mineral from a Mantle AssemblageEos, Vol. 63, No. 45, P. 1141, (abstract.).GlobalJosephine Creek, Bultfontein, Wesselton
DS1987-0664
1987
Buseck, P.R.Sharp, T.G., Buseck, P.R.Serpenitinized phlogopite from micaceous kimberlite,Cape Province, SouthAfricaGeological Society of America, Vol. 19, No. 7 annual meeting abstracts, p.840. abstracSouth AfricaFrank Smith, Kimberlite
DS1990-0593
1990
Buseck, P.R.Graham, R., Buseck, P.R.Cathodluminescence of colored diamonds by transmissionelectronmicroscopyGeological Association of Canada (GAC)/Mineralogical Association of Canada (MAC) Vancouver 90 Program with Abstracts, Held May 16-18, Vol. 15, p. A50. AbstractGlobalDiamond morphology, Cathodluminescence
DS1990-1338
1990
Buseck, P.R.Sharp, T.G., Otten, M.T., Buseck, P.R.Serpentinization of phlogopite phenocrysts from a micaceous kimberliteContributions to Mineralogy and Petrology, Vol. 104, No. 5, pp. 530-539South AfricaFrank Smith mine, Hypabyssal kimberlite
DS1992-0194
1992
Buseck, P.R.Buseck, P.R.Minerals and reactions at the atomic scale: transmission electronmicroscopyMineral Society of America, Reviews in Mineralogy Volume 27, 600p. approx. $ 25.00GlobalBook -table of contents, Microscopy
DS1992-0195
1992
Buseck, P.R.Buseck, P.R., Tsipursky, S.J., Hettich, R.Fullerenes from the geological environmentScience, Vol. 257, July 10, pp. 215-217GlobalFullerenes -natural, Carbon
DS1993-0191
1993
Buseck, P.R.Buseck, P.R.Structural states of carbon -from aerosols to geological formsInternational Congress on Applied Mineralogy, ICAM93, held Fremantle, pp. 71-74GlobalCarbon morphology, Fullerenes, buckyballs
DS1993-0192
1993
Buseck, P.R.Buseck, P.R., Xin HuaMatrices of carbonaceous chondrite meteoritesAnnual Review of Earth and Planetary Sciences, Vol. 21, pp. 255-306GlobalMeteorites
DS1994-0651
1994
Buseck, P.R.Graham, R.J., Buseck, P.R.Cathodluminescence of brown diamonds as observed by transmission electronmicroscopy.Phil. Magazine B., Vol. 70, No. 6, Dec. pp. 1177-1185.GlobalDiamond morphology, Cathodluminescence
DS1996-0330
1996
Buseck, P.R.Daulton, T.L., Eisenhour, D.D., Buseck, P.R.Genesis of presolar diamonds; comparative high-resolution transmission electron microscopy studyGeochimica et Cosmochimica Acta, Vol. 60, No. 23, Dec. 1, pp. 4853-72.GlobalMicroscopy, Meteorites, Nano-diamonds
DS2002-0231
2002
Buseck, P.R.Buseck, P.R.Geological fullerenes: a review and analysisEarth and Planetary Science Letters, Vol. 203, 3-4, pp. 781-92.GlobalFullerenes - review
DS2002-0783
2002
Buseck, P.R.Johnson, C.L., Buseck, P.R.Transmission electron microscopy of dislocation structures in olivine18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.78. (poster)MantleUHP mineralogy, Tectonic processes
DS200612-0115
2005
Buseck, P.R.Bell, D.R., Gregoire, M., Grove, T.L., Chaterjee, N., Carlson, R.W., Buseck, P.R.Silica and volatile element metasomatism of Archean mantle: a xenolith scale example from the Kaapvaal Craton.Contributions to Mineralogy and Petrology, Vol. 150, 3, pp. 251-267.Africa, South AfricaMetasomatism
DS200912-0045
2009
Buseck, P.R.Bell, D.R., Hervig, R.L., Buseck, P.R., Aulbach, S.Lithium isotope analysis of olivine by SIMS: calibration of a matrix effect and application to magmatic phenocrysts.Chemical geology, Vol. 258, 1-2, Jan. pp. 5-16.Africa, South Africa, Tanzania, United StatesPhenocrysts
DS201012-0534
2010
Buseck, P.R.Nemeth, P., Garvie, L., Buseck, P.R.Challenges of identifying diamond polytypes of natural nanodiamonds.International Mineralogical Association meeting August Budapest, abstract p. 797.TechnologyMeteorite
DS201412-0273
2014
Buseck, P.R.Garvie, L.A.J., Nemeth, P., Buseck, P.R.Transformation of graphite to diamond via a topotactic mechanism. Gujba ( meteorite)American Mineralogist, Vol. 99, pp. 531-538.TechnologyCrystallography
DS201901-0091
2018
Buseck, P.R.Wu, J., Desch, S.J., Schaefer, L., Elkins-Tanton, L.T., Pahlevan, K., Buseck, P.R.Origin of Earth's water: chondritic inheritance plus nebular ingassing and storage of hydrogen in the core.Journal of Geophysical Research: Planets, doei:10.1029/ 2018JE005698Mantlewater

Abstract: People have long had curiosity in the origin of Earth's water (equivalently hydrogen). Solar nebula has been given the least attention among existing theories, although it was the predominating reservoir of hydrogen in our early solar system. Here we present a first model for Earth's water origin that quantifies contribution from the solar nebula in addition to that from chondrites, the primary building blocks of Earth. The model considers dissolution of nebular hydrogen into the early Earth's magma oceans and reaction between hydrogen and iron droplets within the magma ocean. Such processes not only delivered countless hydrogen atoms from the mantle to the core but also generated an appreciable difference in hydrogen isotopic composition (2H/1H ratio) between the mantle and core. Fitting the model to current knowledge about Earth's hydrogen produces best combinations of nebular and chondritic contributions to Earth's water. We find that nearly one out of every 100 water molecules on Earth came from the solar nebula. Our planet hides majority of its water inside, with roughly two oceans in the mantle and four to five oceans in the core. These results suggest inevitable formation of water on sufficiently large rocky planets in extrasolar systems.
DS1997-0149
1997
Buselli, G.Buselli, G., Lee, S.K.Modeling of drill-hole TEM responses from multiple targetsExploration Geophysics, Bulletin of Australian, Vol. 27, No. 2-3, Sept. pp. 141-154GlobalGeophysics - TEM, copper, lead, zinc, nickel, Model
DS201412-0130
2014
Busemann, H.Clay, P.L., O'Driscoll, B., Upton, B.G.J., Busemann, H.Characteristics of djerfisherite from fluid rich metasomatized alkaline intrusive environments and anhydrous enstatite chrondrites and achondrites.American Mineralogist, Vol. 99, pp. 1683-93.MantleDjerfisherites
DS2003-0195
2003
Bush, D.Bush, D., Nel, F., Revering, C., Kirkley, M.Geostatistical methods employed in resource evaluation of the Snap Lake diamond8ikc, Www.venuewest.com/8ikc/program.htm, Session 1 POSTER abstractNorthwest TerritoriesKimberlite geology and economics, Deposit - Snap Lake
DS201609-1708
2010
Bush, D.Bush, D.An overview of the estimation of kimberlite diamond deposits.The 4th Colloquium on Diamonds - source to use held Gabarone March 1-3, 2010, 12p.Africa, South AfricaDeposit - Venetia

Abstract: The nature of diamond deposits are such that most mineral resource reporting codes contain a sub-section unique to diamond estimation and classification. These codes identify a number of criteria which define the uniqueness of diamond deposits, including, the low and variable grade of diamond deposits; the particulate nature of diamonds which affects both size and revenue of individual particles and finally the inherent difficulties and uncertainties in the estimation of diamond resources. These criteria are expanded on to provide an overview of the estimation of kimberlite diamond deposits. Placer deposits have been excluded as they constitute a particularly complex example of particulate distributions. Diamond grade, typically of the order of parts per million (ppm), is dependent on the number of stones per unit volume or mass as well as the diamond size distribution while diamond revenue is dependent on size, model, colour and quality. These parameters of a discrete particle result in a conmlOdily which requires some unique estimation and modelling methodologies. For most commodities "grade" is a measure of concentration and is directly proportional to value. [n the case of diamonds however the same stone grade (e.g. stones per 100 tonnes) may have significantly different carat grades and revenue, depending on the characteristics of the individual stones (size, model, colour and quality). The De _Beers Consolidated Mines Venetia Mine is used as an example of diamond eslimation as well as to highlighl some propriety grade eslimation techniques. The mine has been sampled for grade using a number of different sample supports, from 36" diameter reverse circulation drillholes to micro diamond core drilling. De Beers Group Services (Ply) Lld (DBGS) have developed a technique of mixed (or multiple) support kriging which allows for the combination of samples of different sizes (and therefore grade distributions) in the estimation process. In addition DBGS have researched techniques of both global and local grade estimation using micro diamonds. The estimation of kimberlite diamond deposits has a number of unique components resulting from the discrete nature of the diamond distribution. It is however equally fundamentally important to understand exactly what the sampling data represents; the constraints Wlder which the data were coUected (e.g. bottom cut ofJ) and the adjustments necessary to ensure parity Page 73 The Southern African Institute of Mining and Metallurgy Diamonds - Source to Use 2010 DBush between and within sampling programmes as well as the likely metallurgical process III a production environment.
DS201808-1791
2018
Bush, D.Stiefenhofer, J., Thurston, M., Bush, D.Microdiamond grade as a regionalized variable - some basic requirements for successful local microdiamond resource estimation of kimberlite. ( eg Snap Lake) PresentationSAIMM Diamonds - source to use 2018 Conference 'thriving in changing times'. June 11-13., 16 ppts.Globalmicrodiamond
DS201805-0980
2018
Bush, D.E.Stiefenhofer, J., Thurston, M.L., Bush, D.E.Microdiamond grade as a regionalised variable - some basic requirements for successful local microdiamond resource estimation of kimberlites.Mineralogy and Petrology, doi.org/10.1007/ s00710-018-0566-y 12p.Globalmicrodiamonds

Abstract: Microdiamonds offer several advantages as a resource estimation tool, such as access to deeper parts of a deposit which may be beyond the reach of large diameter drilling (LDD) techniques, the recovery of the total diamond content in the kimberlite, and a cost benefit due to the cheaper treatment cost compared to large diameter samples. In this paper we take the first step towards local estimation by showing that micro-diamond samples can be treated as a regionalised variable suitable for use in geostatistical applications and we show examples of such output. Examples of microdiamond variograms are presented, the variance-support relationship for microdiamonds is demonstrated and consistency of the diamond size frequency distribution (SFD) is shown with the aid of real datasets. The focus therefore is on why local microdiamond estimation should be possible, not how to generate such estimates. Data from our case studies and examples demonstrate a positive correlation between micro- and macrodiamond sample grades as well as block estimates. This relationship can be demonstrated repeatedly across multiple mining operations. The smaller sample support size for microdiamond samples is a key difference between micro- and macrodiamond estimates and this aspect must be taken into account during the estimation process. We discuss three methods which can be used to validate or reconcile the estimates against macrodiamond data, either as estimates or in the form of production grades: (i) reconcilliation using production data, (ii) by comparing LDD-based grade estimates against microdiamond-based estimates and (iii) using simulation techniques.
DS1995-0245
1995
Bush, D.V.Bush, D.V.Energy conservation in the mining industryAmerican Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) Preprint, No. 95-44, 4pUnited StatesEnergy -electrical, Mining
DS1991-1745
1991
Bush, M.D.Towie, N.J., Marz, M.R., Bush, M.D., Manning, E.R.The Aries Diamondiferous kimberlite pipe: central Kimberley Block, westernAustraliaProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 435-436AustraliaSampling, prospecting, geophysics, Structure, geochemistry, alluvials
DS1994-1793
1994
Bush, M.D.Towie, N.J., Bush, M.D., Manning, E.R., Marx, M.R., Ramsay, R.R.The Aries Diamondiferous kimberlite pipe central Kimberley Block, westernAustralia: exploration, setting and evaluation.Proceedings of Fifth International Kimberlite Conference, Vol. 2, pp. 319-328.AustraliaDiamond exploration, Deposit -Aries
DS201012-0412
2010
Busharina, S.V.Krasnobaev, A.A., Rusin, A.I., Valizer, P.M., Busharina, S.V.Zirconology of calcite carbonatite of the Vishnevogorsk massif, southern Urals.Doklady Earth Sciences, Vol. 431, 1, pp. 390-393.Russia, UralsCarbonatite
DS201312-0515
2013
Busharina, S.V.Krasnobaev, A.A., Valizer, P.M., Cherednichenko, S.V., Busharina, S.V., Medvedeva, E.V., Presyakov, S.L.Zirconology of carbonate rocks ( marbles-carbonatites) of the Ilmeno-Visnevogorskii complex, southern Urals.Doklady Earth Sciences, Vol. 450, 1, pp. 504-508.Russia, UralsCarbonatite
DS2002-0232
2002
Bushenkova, N.Bushenkova, N., Tychkov, N., Koulakov, I.Tomography on PP-P waves and its application for investigation of the upper mantle in central Siberia.Tectonophysics, Vol. 358, 1-4, pp. 57-76.Russia, SiberiaGeophysics - seismics
DS2000-0129
2000
Bushenkova, N.A.Bushenkova, N.A., Tychkov, S.A., Kulakov, I.Yu.Lateral heterogeneities in the upper mantle beneath southern Siberia and eastern Kazakhstan from PP SS P..Russian Geology and Geophysics, Vol.41,No.8, pp. 1080-95.Russia, SiberiaGeophysics - seismics
DS201212-0336
2012
Bushenkova, N.A.Jakovlev, A.V., Bushenkova, N.A., Koulakov, I.yu., Dobretsov, N.L.Structure of the upper mantle in the circum-artic region from regional seismic tomography.Russian Geology and Geophysics, Vol. 53, 10. pp. 963-971.RussiaGeophysics - seismic
DS1998-0192
1998
Bushev, A.G.Bushev, A.G., Portnov, A.M., Rogozhin, A.A., et al.Photoluminescent mineral haloes around kimberlite pipesIma 17th. Abstract Vol., p. A125, abstractRussia, ArkangelskMineralogy, Photoluminesence
DS1990-0258
1990
Busheva, E.B.Busheva, E.B., Vasiljeva, E.R., Garanin, V.K., KudrjavtsevaMineralogy of kimberlites of the northern European part of the USSRInternational Mineralogical Association Meeting Held June, 1990 Beijing China, Vol. 2, extended abstract p. 786-788RussiaKimberlites, Mineralogy
DS201604-0636
2016
Bushi, A.M.Thomas, R.J, Spencer, C., Bushi, A.M., Baglow, N., Gerrit de Kock, B., Hortswood, M.S.A., Hollick, L., Jacobs, J., Kajara, S., Kaminhanda, G., Key, R.M., Magana, Z., McCourt, M.W., Momburi, P., Moses, F., Mruma, A., Myamilwa, Y., Roberts, N.M.W., HamisiGeochronology of the centra Tanzania craton and its southern and eastern orogenic margins.Precambrian Research, in press available 57p.Africa, TanzaniaGeochronology

Abstract: Geological mapping and zircon U-Pb/Hf isotope data from 35 samples from the central Tanzania Craton and surrounding orogenic belts to the south and east allow a revised model of Precambrian crustal evolution of this part of East Africa. The geochronology of two studied segments of the craton shows them to be essentially the same, suggesting that they form a contiguous crustal section dominated by granitoid plutons. The oldest orthogneisses are dated at ca. 2820 Ma (Dodoma Suite) and the youngest alkaline syenite plutons at ca. 2610 Ma (Singida Suite). Plutonism was interrupted by a period of deposition of volcano-sedimentary rocks metamorphosed to greenschist facies, directly dated by a pyroclastic metavolcanic rock which gave an age of ca. 2725 Ma. This is supported by detrital zircons from psammitic metasedimentary rocks, which indicate a maximum depositional age of ca. 2740 Ma, with additional detrital sources 2820 and 2940 Ma. Thus, 200 Ma of episodic magmatism in this part of the Tanzania Craton was punctuated by a period of uplift, exhumation, erosion and clastic sedimentation/volcanism, followed by burial and renewed granitic to syenitic magmatism. In eastern Tanzania (Handeni block), in the heart of the East African Orogen, all the dated orthogneisses and charnockites (apart from those of the overthrust Neoproterozoic granulite nappes), have Neoarchaean protolith ages within a narrow range between 2710 and 2630 Ma, identical to (but more restricted than) the ages of the Singida Suite. They show evidence of Ediacaran "Pan-African" isotopic disturbance, but this is poorly defined. In contrast, granulite samples from the Wami Complex nappe were dated at ca. 605 and ca. 675 Ma, coeval with previous dates of the "Eastern Granulites" of eastern Tanzania and granulite nappes of adjacent NE Mozambique. To the south of the Tanzania Craton, samples of orthogneiss from the northern part of the Lupa area were dated at ca. 2730 Ma and clearly belong to the Tanzania Craton. However, granitoid samples from the southern part of the Lupa "block" have Palaeoproterozoic (Ubendian) intrusive ages of ca. 1920 Ma. Outcrops further south, at the northern tip of Lake Malawi, mark the SE continuation of the Ubendian belt, albeit with slightly younger ages of igneous rocks (ca. 1870-1900 Ma) which provide a link with the Ponte Messuli Complex, along strike to the SE in northern Mozambique. In SW Tanzania, rocks from the Mgazini area gave Ubendian protolith ages of ca. 1980-1800 Ma, but these rocks underwent Late Mesoproterozoic high-grade metamorphism between 1015 and 1040 Ma. One granitoid gave a crystallisation age of ca. 1080 Ma correlating with known Mesoproterozoic crust to the east in SE Tanzania and NE Mozambique. However, while the crust in the Mgazini area was clearly one of original Ubendian age, reworked and intruded by granitoids at ca. 1 Ga, the crust of SE Tanzania is a mixed Mesoproterozoic terrane and a continuation from NE Mozambique. Hence the Mgazini area lies at the edge of the Ubendian belt which was re-worked during the Mesoproterozoic orogen (South Irumide belt), providing a further constraint on the distribution of ca. 1 Ga crust in SE Africa. Hf data from near-concordant analyses of detrital zircons from a sample from the Tanzania Craton lie along a Pb-loss trajectory (Lu/Hf = 0), extending back to ?3.9 Ga. This probably represents the initial depleted mantle extraction event of the cratonic core. Furthermore, the Hf data from all igneous samples, regardless of age, from the entire study area (including the Neoproterozoic granulite nappes) show a shallow evolution trend (Lu/Hf = 0.028) extending back to the same mantle extraction age. This implies the entire Tanzanian crust sampled in this study represents over 3.5 billion years of crustal reworking from a single crustal reservoir and that the innermost core of the Tanzanian Craton that was subsequently reworked was composed of a very depleted, mafic source with a very high Lu/Hf ratio. Our study helps to define the architecture of the Tanzanian Craton and its evolution from a single age-source in the early Eoarchaean.
DS1986-0382
1986
Bushlyakov, I.N.Ionov, D.A., Bushlyakov, I.N., Kovalenko, V.I.Fluorine and Chlorine contnent of phlogopite, amphibole and apatite of deep xenoliths of the Shavaryn-Tsaram volcano in Mongolia.(Russian)Doklady Academy of Sciences Akademy Nauk SSSR, (Russian), Vol. 287, No. 5, pp. 1205-1209RussiaBlank
DS1985-0667
1985
Bushnell, T.G.Thorp, J.S., Bushnell, T.G.Ultrasonic Examination of Reaction Bonded Silicon NitrideJournal of MATERIALS SCIENCE., Vol. 20, PP. 2265-2274.GlobalBlank
DS1991-0936
1991
Bushueva, E.B.Kudrjavtseva, G.P., Bushueva, E.B., Vasiljeva, E.R., Verichev, E.M.Geological structure and mineralogy of the kimberlites of the Archangelsk kimberlite provinceProceedings of Fifth International Kimberlite Conference held Araxa June 1991, Servico Geologico do Brasil (CPRM) Special, pp. 530-532RussiaDiatremes, Structure
DS201212-0177
2012
Bushueva, E.B.Dyakonov, D.B., Garanin, VK., Garanin, K.V., Bushueva, E.B., Enalieva, M.A., Wedensky, E.S.Searching for new diamond deposits in western Liberia.10th. International Kimberlite Conference Held Bangalore India Feb. 6-11, Poster abstractAfrica, LiberiaProspects - Yambassen, Kumgbo
DS1981-0107
1981
Bushuyeva, Ye.B.Bushuyeva, Ye.B., Nekrasov, I.YA., et al.Infrared Spectra of Chrome Spinellids from Kimberlitic Rocks of Siberia.Doklady Academy of Science USSR, Earth Science Section., Vol. 247, No. 1-6, PP. 159-162.RussiaMicroscopy
DS201212-0112
2012
Busigny, V.Cartigny, P., Palot, M., Clog, M., Labidi, J., Thomassot, E., Aubaud, C., Busigny, V., Harris, J.W.On overview of the deep carbon cycle and its isotope heterogeneity.Goldschmidt Conference 2012, abstract 1p.MantleCarbon cycle
DS201312-0115
2013
Busigny, V.Busigny, V., Bebout, G.E.Nitrogen and its ( Biogeocosmo) chemical cycling: nitrogen in the silicate Earth: speciation and isotopic behavior during mineral-fluid interactions.Elements, Vol. 9, pp. 353-358.TechnologyNitrogen
DS1982-0126
1982
Business And Tech. Systems IncBusiness And Tech. Systems IncRemanent Magnetism and Three Dimensional Density Model of The Kentucky Anomaly Region.National Technical Information Service NASA CR/170056 E83-10210, 3P.GlobalMid-continent, Gravity, Magnetics, Magsat
DS200812-0164
2008
Business DayBusiness DayDiamondCorp's Lac on track.businessday.co.za, Sept. 26, 1p.Africa, South AfricaNews item - DiamondCorp
DS200412-0251
2004
Business News AmericaBusiness News AmericaIndians, miners clash over diamonds.Business News America, April 21, 1/4p.South America, BrazilNews item
DS200812-0165
2008
Business ReportBusiness Report, InfomineGabarone is really De Beers best friend.busrep.c.za, March 25, 2p.Africa, BotswanaNews item - De Beers
DS200812-0166
2008
Business StandardBusiness StandardDiamonds to get dearer as rough stones cost more.Guajarta Gems & Gemology Export Promotion Council, May 13, 1/4p.IndiaNews item - diamond prices
DS200812-0167
2008
Business YahooBusiness YahooNew policy likely to be unfolded by the Indian Ministry of Mines is set to attract a foreign direct investment (FDI) of INR5 Trillion within 5 - 6 years.Business Yahoo, March 26, 1p.IndiaNews item - economics
DS200812-0168
2008
BusinessedgeBusinessedgeDiamond producers bullish on prospects. De Beers.BusinessEdge, Nov. 14, 1p.GlobalNews item - De Beers
DS1993-0360
1993
Buslov, M.M.Dobretsov, N.L., Buslov, M.M., Simonov, V.A.Associated ophiolites, glaucophane schists and eclogites of the GornyyAltai.Doklady Academy of Sciences USSR, Vol. 318, pp. 123-127.RussiaEclogites
DS2002-1194
2002
Buslov, M.M.Ota, T., Buslov, M.M., Watanabe, T.Metamorphic evolution of late Precambrian eclogites and associated metabasites, Gorny Altai, southern Russia.International Geology Review, Vol. 44, 9, pp. 837-58.RussiaEclogites
DS200512-0236
2004
Buslov, M.M.Dobretsov, N.L., Buslov, M.M.Serpentinitic melanges associated with HP and UHP rocks in central Asia.International Geology Review, Vol. 46, 11, pp. 957-980.China, AsiaUHP
DS200512-0237
2005
Buslov, M.M.Dobretsov, N.L., Buslov, M.M., Zhimulev, F.I., Travin, A.V.The Kochetav Massif as a deformed Cambrian-Early Caradocian collision subduction zone.Doklady Earth Sciences, Vol. 402, 4, pp. 501-505.RussiaSubduction
DS200512-0926
2004
Buslov, M.M.Safronov, I.Yu., Buslov, M.M.Geochemistry of oceanic basalts of the Katun accretionary wedge in northern Gorny Altai: evidence for mantle plume magmatism.Deep seated magmatism, its sources and their relation to plume processes., pp. 273-298.Russia, MantleMagmatism
DS200612-0336
2006
Buslov, M.M.Dobretsov, N.I., Buslov, M.M., Zhimulev, F.I., Travin, A.V., Zayachkovsky, A.A.Vendian Early Ordovician geodynamic evolution and model for exhumation of ultrahigh and high pressure rocks from the Kokchetav subduction collision zone.Russian Geology and Geophysics, Vol. 47, 4, pp. 424-440.Russia, KazakhstanUHP
DS200612-1201
2005
Buslov, M.M.Safonova, I.Yu., Buslov, M.M.Geochemical diversity in oceanic basalts of the Zasurin Formation NE Altai Russia: trace element evidence for mantle plume magmatism.Problems of Sources of deep magmatism and plumes., pp. 247-266.Russia, AltaiMagmatism
DS200812-0169
2008
Buslov, M.M.Buslov, M.M., Vovna, G.M.Composition and geodynamic nature of protoliths of Diamondiferous rocks from the Kumdy-Kol of the Jokchetav metamorphic belt, northern Kazakhstan.Geochemistry International, Vol. 46, 9, pp. 887-896.Russia, KazakhstanDeposit - Kumdy Kol
DS201312-0215
2013
Buslov, M.M.Dobretsov, N.L., Buslov, M.M., De Grave, J., Sklyarov, E.V.Interplay of magmatism, sedimentation, and collision processes in the Siberian craton and the flanking orogens.Russian Geology and Geophysics, Vol. 54, 10, pp. 1135-1149.RussiaMagmatism
DS201412-0299
2014
Buslov, M.M.Glorie, S., Zhimulev, F.I., Buslov, M.M., Andersen, T., Plavsa, D., Izmer, A., Vanhaecke, F., De Grave, J.Formation of the Kokchetav subduction collision zone - northern Kazakhstan : insights from zircon U-Pb and Lu-Hf isotope systematics.Gondwana Research, Vol. 27, pp. 424-438.Russia, KazakhstanSubduction
DS201502-0047
2015
Buslov, M.M.Buslov, M.M., Dobretsov, N.L., Vovna, G.M., Kiselev, V.I.Structural location, composition, and geodynamic nature of diamond bearing metamorphic rocks of the Kokchetav subduction-collision zone of the Central Asian Fold Belt ( Northern Kazakhstan).Russian Geology and Geophysics, Vol. 56, 1-2, pp. 64-80.Russia, KazakhstanKokchetav massif

Abstract: We present data on different aspects of geology, mineralogy, petrology, geochemistry, and geochronology of diamond-bearing metamorphic rocks of the Kumdy-Kol terrane, which show the similarity of their protolith to the sedimentary rocks of the Kokchetav microcontinent. The structural location of the studied objects in the accretion-collision zone evidences that the subduction of the Kokchetav microcontinent beneath the Vendian-Cambrian Ishim-Selety island arc is the main mechanism of transport of graphite-bearing terrigenous-carbonate rocks to zones of their transformation into diamond-bearing metamorphic rocks. The sedimentary rocks of the Kokchetav microcontinent, which are enriched in graphite and iron sulfides and carbonates, contain all components necessary for diamond crystallization in deep-seated subduction zone. This is in agreement with the experimental data and the compositions of fluid-melt inclusions in the minerals of diamond-bearing rocks.
DS1985-0101
1985
Busnardo, C.A.Busnardo, C.A., Oliveira, R.N.Optimization of the Grinding Circuit of the Jacupiranga Carbonatite Ore.American Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) PREPRINT., No. 85-98, 8P.BrazilMining Methods
DS1997-0150
1997
Bussard, D.Bussard, D.Overview of technical auditsAssaying and Reporting Conference Nov. 10-11, 1997 Singapore, 11p. 9 slide copiesAustraliaSampling, assaying, ore reserves, discoveries, Geostatistics, gold, economics, financial
DS200612-0798
2006
Busse, F.H.Lenardic, A., Richards, M.A., Busse, F.H.Depth dependent rheology and the horizontal length scale of mantle convection.Journal of Geophysical Research, Vol. 111, B7 B07404MantleGeophysics - seismics
DS200612-0799
2006
Busse, P.H.Lenardic, A., Richards, M.A., Busse, P.H.Depth dependent rheology and the horizontal length scale of mantle convection.Journal of Geophysical Research, Vol. 111, B7 B07404MantleGeophysics - seismics
DS1992-0196
1992
Busseck, P.R.Busseck, P.R.Geological occurrence of fullerenesGeological Society of America (GSA) Abstracts with programs, 1992 Annual, Vol. 24, No. 7, abstract p. A117RussiaFullerenes -natural, Shungite -coal
DS201605-0817
2016
Busseweiler, Y.Busseweiler, Y.Al-in-olivine thermometry: experimental versus empirical calibration and analytical challenges.DCO Edmonton Diamond Workshop, June 8-10TechnologyGeothermometry
DS1986-0118
1986
Bussod, G.Bussod, G., Williams, D.Thermal evolution of the lower crust and upper mantle in the southern Rio Grande riftEos, Vol. 67, No. 44, Nov. 4, p. 1183. AbstractNew Mexico, TexasMantle, Thermometry
DS1992-1694
1992
Bussod, G.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
DS1981-0108
1981
Bussod, G.Y.Bussod, G.Y., Irving, A.J.Thermal and Rheologic History of the Upper Mantle Beneath The Southern Rio Grande Rift; Evidence from Kilbourne Hole Xenoliths.In: Papers Presented To The Conference On The Processes of P, No. 457, PP. 145-148.GlobalBlank
DS1982-0127
1982
Bussod, G.Y.Bussod, G.Y.Nature of the Continental Upper-mantle Lower Crust Transition Beneath Kilbourne Hole, New Mexico.Proceedings of Third International Kimberlite Conference, TERRA COGNITA, ABSTRACT VOLUME., Vol. 2, No. 3, PP. 266-267, (abstract.).GlobalKimberlite, Colorado Plateau Rocky Mountains
DS1989-0195
1989
Bussod, G.Y.Bussod, G.Y.Piezothermometric measures on Kilbourne Hole xenoliths and constraints on the thermal evolution of the southern Rio Grande riftNew Mexico Bureau of Mines Bulletin., Continental Magmatism Abstract Volume, Held, Bulletin. No. 131, p. 306. AbstractNew MexicoXenoliths, Tectonics
DS1996-1259
1996
Bussod, G.Y.Schmeling, H., Bussod, G.Y.Variable viscosity convection and partial melting in the continentalasthenosphere.Journal of Geophysical Research, Vol. 101, No. 3, March 10, pp. 5411-MantleGeophysics -seismics, Melting
DS1991-0201
1991
Bussod, G.Y.A.Bussod, G.Y.A., Williams, D.R.Thermal and kinematic model of the southern Rio Grande Rift- inferences from crustal and mantle xenoliths from Kilbourne Hole, New MexicoTectonophysics, Vol. 197, No. 2-4, October 30, pp. 373-390New MexicoTectonics, Rio Grande Rift, Kilbourne Hole
DS201412-0086
2014
Bussweiler, Y.Bussweiler, Y., Foley, S.F., Prelevic, D., Jacob, D.E., Pearson, D.G., Stachel, T.Olivine as a petrogenetic and exploration indicator in Lac de Gras kimberlites.2014 Yellowknife Geoscience Forum, p. 20, 21 abstractCanada, Northwest TerritoriesDeposit - Ekati
DS201504-0187
2015
Bussweiler, Y.Bussweiler, Y., Foley, S.F., Prelevic, D., Jacob, D.E.The olivine macrocryst problem: new insights from minor and trace element compositions of olivine from Lac de Gras kimberlites, Canada.Lithos, Vol. 220-223, pp. 238-252.Canada, Northwest TerritoriesDeposit - Ekati field

Abstract: This study presents detailed petrographical and geochemical investigations on remarkably fresh olivines in kimberlites from the EKATI Diamond Mine- located in the Tertiary/Cretaceous Lac de Gras kimberlite field within the Slave craton of Canada. Olivine, constituting about 42 vol.% of the analyzed samples, can be divided into two textural groups: (i) macrocrystic olivines, > 100 ?m sub-rounded crystals and (ii) groundmass olivines, < 100 ?m subhedral crystals. Olivines from both populations define two distinct chemical trends; a “ "mantle trend" with angular cores, showing low Ca (< 0.1 wt.% CaO) and high Ni (0.3-0.4 wt.% NiO) at varying Mg# (0.86-0.93), contrasts with a "melt trend" typified by thin (< 100 ?m) rims with increasing Ca (up to 1.0 wt.% CaO) and decreasing Ni (down to 0.1 wt.% NiO) contents at constant Mg# (~ 0.915). These findings are in agreement with recent studies suggesting that virtually all olivine is composed of xenocrystic (i.e. mantle-related) cores with phenocrystic (i.e. melt-related) overgrowths, thereby challenging the traditional view that the origin of kimberlitic olivine can be distinguished based on size and morphology. The two main trends can be further resolved into sub-groups refining the crystallization history of olivine; the mantle trend indicates a multi-source origin that samples the layered lithosphere below the Slave craton, whereas the melt trend represents multi-stage crystallization comprising a differentiation trend starting at mantle conditions and a second trend controlled by the crystallization of additional phases (e.g. chromite) and changing magma conditions (e.g. oxidation). These trends are also seen in the concentrations of trace elements not routinely measured in olivine (e.g. Na, P, Ti, Co, Sc, Zr). Trace element mapping with LA-ICP-MS reveals the distribution of these elements within olivine grains. The trace element distribution between the two trends appears to be consistent with phenocrystic olivine overgrowths mainly originating from dissolved orthopyroxene, showing enrichment in Zr, Ga, Nb, Sc, V, P, Al, Ti, Cr, Ca and Mn in the melt trend. In a sample of magmatic kimberlite from the Leslie pipe, the amount of xenocrystic and phenocrystic olivine is estimated to be around 23 vol.% and 19 vol.%, respectively. Subtraction of this xenocrystic olivine from the Leslie bulk composition, aimed at estimating the parental kimberlite melt, results in a minor decrease of Mg# (by about 0.01) and SiO2 content (by about 3 wt.%), whereas CaO increases (by about 3 wt.%).
DS201604-0596
2016
Bussweiler, Y.Bussweiler, Y., Pearson, D.G., Luth, R.W., Kjarsgaard, B.A., Stachel, T.The evolution of calcite-bearing kimberlite by rock-melt reaction during ascent - evidence from polymineralic inclusions within Cr- diopside and Cr-pyrope megacrysts from Lac de Gras kimberlites, Northwest Territories, Canada.GAC MAC Meeting Special Session SS11: Cratons, kimberlites and diamonds., abstract 1/4p.Canada, Northwest TerritoriesDeposit - Lac de Gras
DS201607-1288
2016
Bussweiler, Y.Bussweiler, Y., Stone, R.S., Pearson, D.G., Luth, R.W., Stachel, T., Kjarsgaard, B.A., Menzies, A.The evolution of calcite bearing kimberlites by melt rock reaction: evidence from polymineralic inclusions within clinopyroxene and garnet megacrysts from Lac de Gras kimberlites, Canada.Contributions to Mineralogy and Petrology, Vol. 171, 7, 25p.Canada, Northwest TerritoriesDeposit - Lac de Gras arena

Abstract: Megacrystic (>1 cm) clinopyroxene (Cr-diopside) and garnet (Cr-pyrope) xenocrysts within kimberlites from Lac de Gras (Northwest Territories, Canada) contain fully crystallized melt inclusions. These ‘polymineralic inclusions’ have previously been interpreted to form by necking down of melts at mantle depths. We present a detailed petrographical and geochemical investigation of polymineralic inclusions and their host crystals to better understand how they form and what they reveal about the evolution of kimberlite melt. Genetically, the megacrysts are mantle xenocrysts with peridotitic chemical signatures indicating an origin within the lithospheric mantle (for the Cr-diopsides studied here ~4.6 GPa, 1015 °C). Textural evidence for disequilibrium between the host crystals and their polymineralic inclusions (spongy rims in Cr-diopside, kelyphite in Cr-pyrope) is consistent with measured Sr isotopic disequilibrium. The preservation of disequilibrium establishes a temporal link to kimberlite eruption. In Cr-diopsides, polymineralic inclusions contain phlogopite, olivine, chromite, serpentine, and calcite. Abundant fluid inclusion trails surround the inclusions. In Cr-pyropes, the inclusions additionally contain Al-spinel, clinopyroxene, and dolomite. The major and trace element compositions of the inclusion phases are generally consistent with the early stages of kimberlite differentiation trends. Extensive chemical exchange between the host phases and the inclusions is indicated by enrichment of the inclusions in major components of the host crystals, such as Cr2O3 and Al2O3. This chemical evidence, along with phase equilibria constraints, supports the proposal that the inclusions within Cr-diopside record the decarbonation reaction: dolomitic melt + diopside ? forsterite + calcite + CO2, yielding the observed inclusion mineralogy and producing associated (CO2-rich) fluid inclusions. Our study of polymineralic inclusions in megacrysts provides clear mineralogical and chemical evidence for an origin of kimberlite that involves the reaction of high-pressure dolomitic melt with diopside-bearing mantle assemblages producing a lower-pressure melt that crystallizes a calcite-dominated assemblage in the crust.
DS201608-1397
2016
Bussweiler, Y.Bussweiler, Y., Stone, R.S., Pearson, D.G., Luth, R.W., Stachel, T., Kjarsgaard, B.A., Menzies, A.The evolution of calcite bearing kimberlites by melt rock reaction: evidence from polymineralic inclusions within clinopyroxene and garnet megacrysts from Lac de Gras kimberlites, Canada.Contributions to Mineralogy and Petrology, in press available 25p.Canada, Northwest TerritoriesDeposit - Lac de Gras

Abstract: Megacrystic (>1 cm) clinopyroxene (Cr-diopside) and garnet (Cr-pyrope) xenocrysts within kimberlites from Lac de Gras (Northwest Territories, Canada) contain fully crystallized melt inclusions. These ‘polymineralic inclusions’ have previously been interpreted to form by necking down of melts at mantle depths. We present a detailed petrographical and geochemical investigation of polymineralic inclusions and their host crystals to better understand how they form and what they reveal about the evolution of kimberlite melt. Genetically, the megacrysts are mantle xenocrysts with peridotitic chemical signatures indicating an origin within the lithospheric mantle (for the Cr-diopsides studied here ~4.6 GPa, 1015 °C). Textural evidence for disequilibrium between the host crystals and their polymineralic inclusions (spongy rims in Cr-diopside, kelyphite in Cr-pyrope) is consistent with measured Sr isotopic disequilibrium. The preservation of disequilibrium establishes a temporal link to kimberlite eruption. In Cr-diopsides, polymineralic inclusions contain phlogopite, olivine, chromite, serpentine, and calcite. Abundant fluid inclusion trails surround the inclusions. In Cr-pyropes, the inclusions additionally contain Al-spinel, clinopyroxene, and dolomite. The major and trace element compositions of the inclusion phases are generally consistent with the early stages of kimberlite differentiation trends. Extensive chemical exchange between the host phases and the inclusions is indicated by enrichment of the inclusions in major components of the host crystals, such as Cr2O3 and Al2O3. This chemical evidence, along with phase equilibria constraints, supports the proposal that the inclusions within Cr-diopside record the decarbonation reaction: dolomitic melt + diopside ? forsterite + calcite + CO2, yielding the observed inclusion mineralogy and producing associated (CO2-rich) fluid inclusions. Our study of polymineralic inclusions in megacrysts provides clear mineralogical and chemical evidence for an origin of kimberlite that involves the reaction of high-pressure dolomitic melt with diopside-bearing mantle assemblages producing a lower-pressure melt that crystallizes a calcite-dominated assemblage in the crust.
DS201709-1968
2017
Bussweiler, Y.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].
DS201807-1482
2018
Bussweiler, Y.Bussweiler, Y., Pearson, D.G., Stachel, T., Kjarsgaard, B.A.Cr-rich megacrysts of clinopyroxene and garnet from Lac de Gras kimberlites, Slave Craton, Canada - implications for the origin of clinopyroxene and garnet in cratonic lherzolites.Mineralogy and Petrology, 10.1007/s00710 -018-0599-2, 14p. Canada, Northwest Territoriesdeposit - Diavik, Ekati

Abstract: Kimberlites from the Diavik and Ekati diamond mines in the Lac de Gras kimberlite field contain abundant large (>1 cm) clinopyroxene (Cr-diopside) and garnet (Cr-pyrope) crystals. We present the first extensive mineral chemical dataset for these megacrysts from Diavik and Ekati and compare their compositions to cratonic peridotites and megacrysts from the Slave and other cratons. The Diavik and Ekati Cr-diopside and Cr-pyrope megacrysts are interpreted to belong to the Cr-rich megacryst suite. Evidence for textural, compositional, and isotopic disequilibrium suggests that they constitute xenocrysts in their host kimberlites. Nevertheless, their formation may be linked to extensive kimberlite magmatism and accompanying mantle metasomatism preceding the eruption of their host kimberlites. It is proposed that the formation of megacrysts may be linked to failed kimberlites. In this scheme, the Cr-rich megacrysts are formed by progressive interaction of percolating melts with the surrounding depleted mantle (originally harzburgite). As these melts percolate outwards, they may contribute to the introduction of clinopyroxene and garnet into the depleted mantle, thereby forming lherzolite. This model hinges on the observation that lherzolitic clinopyroxenes and garnets at Lac de Gras have compositions that are strikingly similar to those of the Cr-rich megacrysts, in terms of major and trace elements, as well as Sr isotopes. As such, the Cr-rich megacrysts may have implications for the origin of clinopyroxene and garnet in cratonic lherzolites worldwide.
DS201812-2878
2018
Bussweiler, Y.Shaikh, A.M., Patel, S.C., Bussweiler, Y., Kumar, S.P.K., Tappe, S., Mainkar, D. Ravi, S.Olivine trace element compositions in diamondiferous lamproites from India: proxies for magma origins and the nature of the lithosphere mantle beneath the Bastar and Dharwar cratons. CC2 and P13 Wajrakarur, Kodomali, Behradih Mainpur Lithos, doi:10.1016/j. lithos.2018.11.026 35p.Indiadeposit - Wajrakarur, Mainpur

Abstract: The ~1100 Ma CC2 and P13 lamproite dykes in the Wajrakarur Kimberlite Field (WKF), Eastern Dharwar Craton, and ~65 Ma Kodomali and Behradih lamproite diatremes in the Mainpur Kimberlite Field (MKF), Bastar Craton share a similar mineralogy, although the proportions of individual mineral phases vary significantly. The lamproites contain phenocrysts, macrocrysts and microcrysts of olivine set in a groundmass dominated by diopside and phlogopite with a subordinate amount of spinel, perovskite, apatite and serpentine along with rare barite. K-richterite occurs as inclusion in olivine phenocrysts in Kodomali, while it is a late groundmass phase in Behradih and CC2. Mineralogically, the studied intrusions are classified as olivine lamproites. Based on microtextures and compositions, three distinct populations of olivine are recognised. The first population comprises Mg-rich olivine macrocrysts (Fo89-93), which are interpreted to be xenocrysts derived from disaggregated mantle peridotites. The second population includes Fe-rich olivine macrocrysts (Fo82-89), which are suggested to be the product of metasomatism of mantle wall-rock by precursor lamproite melts. The third population comprises phenocrysts and overgrowth rims (Fo83-92), which are clearly of magmatic origin. The Mn and Al systematics of Mg-rich olivine xenocrysts indicate an origin from diverse mantle lithologies including garnet peridotite, garnet-spinel peridotite and spinel peridotite beneath the WKF, and mostly from garnet peridotite beneath the MKF. Modelling of temperatures calculated using the Al-in-olivine thermometer for olivine xenocrysts indicates a hotter palaeogeotherm of the SCLM beneath the WKF (between 41 and 43 mW/m2) at ~1100 Ma than beneath the MKF (between 38 and 41 mW/m2) at ~65 Ma. Further, a higher degree of metasomatism of the SCLM by precursor lamproite melts has occurred beneath the WKF compared to the MKF based on the extent of CaTi enrichment in Fe-rich olivine macrocrysts. For different lamproite intrusions within a given volcanic field, lower Fo olivine overgrowth rims are correlated with higher phlogopite plus oxide mineral abundances. A comparison of olivine overgrowth rims from the two fields shows that WKF olivines with lower Fo content than MKF olivines are associated with increased XMg in spinel and phlogopite and vice versa. Melt modelling indicates relatively Fe-rich parental melt for WKF intrusions compared to MKF intrusions. The Ni/Mg and Mn/Fe systematics of magmatic olivines indicate derivation of the lamproite melts from mantle source rocks with a higher proportion of phlogopite and/or lower proportion of orthopyroxene for the WKF on the Eastern Dharwar Craton compared to those for the MKF on the Bastar Craton. This study highlights how olivine cores provide important insights into the composition and thermal state of cratonic mantle lithosphere as sampled by lamproites, including clues to elusive precursor metasomatic events. Variable compositions of olivine rims testify to the complex interplay of parental magma composition and localised crystallisation conditions including oxygen fugacity variations, co-crystallisation of groundmass minerals, and assimilation of entrained material.
DS201901-0075
2018
Bussweiler, Y.Shaikh, A.M., Patel, S.C., Bussweiler, Y., Kumar, S.P., Tappe, S., Ravi, S., Mainkar, D.Olivine trace element compositions in diamondiferous lamproites from India: proxies for magma origins and the nature of the lithospheric mantle beneath the Bastar and Dharwar cratons.Lithos, doi.org.10.1016/j.lithos.2018.11.026Indiadeposit - Wajrakarur, Mainpur

Abstract: The ~1100?Ma CC2 and P13 lamproite dykes in the Wajrakarur Kimberlite Field (WKF), Eastern Dharwar Craton, and ~65?Ma Kodomali and Behradih lamproite diatremes in the Mainpur Kimberlite Field (MKF), Bastar Craton share a similar mineralogy, although the proportions of individual mineral phases vary significantly. The lamproites contain phenocrysts, macrocrysts and microcrysts of olivine set in a groundmass dominated by diopside and phlogopite with a subordinate amount of spinel, perovskite, apatite and serpentine along with rare barite. K-richterite occurs as inclusion in olivine phenocrysts in Kodomali, while it is a late groundmass phase in Behradih and CC2. Mineralogically, the studied intrusions are classified as olivine lamproites. Based on microtextures and compositions, three distinct populations of olivine are recognised. The first population comprises Mg-rich olivine macrocrysts (Fo89-93), which are interpreted to be xenocrysts derived from disaggregated mantle peridotites. The second population includes Fe-rich olivine macrocrysts (Fo82-89), which are suggested to be the product of metasomatism of mantle wall-rock by precursor lamproite melts. The third population comprises phenocrysts and overgrowth rims (Fo83-92), which are clearly of magmatic origin. The Mn and Al systematics of Mg-rich olivine xenocrysts indicate an origin from diverse mantle lithologies including garnet peridotite, garnet-spinel peridotite and spinel peridotite beneath the WKF, and mostly from garnet peridotite beneath the MKF. Modelling of temperatures calculated using the Al-in-olivine thermometer for olivine xenocrysts indicates a hotter palaeogeotherm of the SCLM beneath the WKF (between 41 and 43?mW/m2) at ~1100?Ma than beneath the MKF (between 38 and 41?mW/m2) at ~65?Ma. Further, a higher degree of metasomatism of the SCLM by precursor lamproite melts has occurred beneath the WKF compared to the MKF based on the extent of CaTi enrichment in Fe-rich olivine macrocrysts. For different lamproite intrusions within a given volcanic field, lower Fo olivine overgrowth rims are correlated with higher phlogopite plus oxide mineral abundances. A comparison of olivine overgrowth rims from the two fields shows that WKF olivines with lower Fo content than MKF olivines are associated with increased XMg in spinel and phlogopite and vice versa. Melt modelling indicates relatively Fe-rich parental melt for WKF intrusions compared to MKF intrusions. The Ni/Mg and Mn/Fe systematics of magmatic olivines indicate derivation of the lamproite melts from mantle source rocks with a higher proportion of phlogopite and/or lower proportion of orthopyroxene for the WKF on the Eastern Dharwar Craton compared to those for the MKF on the Bastar Craton. This study highlights how olivine cores provide important insights into the composition and thermal state of cratonic mantle lithosphere as sampled by lamproites, including clues to elusive precursor metasomatic events. Variable compositions of olivine rims testify to the complex interplay of parental magma composition and localised crystallisation conditions including oxygen fugacity variations, co-crystallisation of groundmass minerals, and assimilation of entrained material.
DS201906-1279
2019
Bussweiler, Y.Bussweiler, Y., Grutzner, T., Rohrbach, A., Klenne, S.New insights into cratonic mantle metasomatism from HP-HT reaction experiments between saline fluids and mantle rocks.GAC/MAC annual Meeting, 1p. Abstract p. 67.Mantlemetasomatism

Abstract: Saline (Cl-rich) fluids potentially play an important role as metasomatic agents in the lithospheric mantle. Natural evidence for deep saline fluids exists as inclusions within diamonds and within groundmass minerals in kimberlites. Previous experimental studies have investigated melting relations in the chloride-carbonate-silicate system at upper mantle conditions, but a systematic experimental study of how saline fluids react with the lithospheric mantle is still lacking. Here, we present high-pressure, high-temperature (HP-HT) reaction experiments between a saline fluid and different mantle rocks (lherzolite, harzburgite, eclogite) at conditions corresponding to the lower cratonic lithosphere. Experiments were performed over a P-T range of 3-6 GPa and 1050-1300 °C using a multi-anvil apparatus. Preliminary results show that the interaction between saline fluid and mantle rocks is very reactive, compared to reactions with silico-carbonate melts. The reaction between saline fluid and lherzolite at 4 GPa and 1200 °C leads to extensive melting. The restite consists mainly of olivine and garnet, whereas pyroxenes are only observed as rare inclusions within garnet. In contrast, reactions between saline fluid and eclogite at 4 GPa and 1200 °C also lead to melting, but the melt is more enriched in Si. The restite consists exclusively of garnet. The experimental results demonstrate how saline fluids react with different components of the lithospheric mantle and support evolutionary models of high density fluids within diamonds.
DS201908-1773
2019
Bussweiler, Y.Bussweiler, Y., Giuliani, A., Greig, A., Kjarsgaard, B.A., Petts, D., Jackson, S.E., Barrett, N., Luo, Y., Pearson, D.G.Trace element analysis of high-Mg olivine by LA-ICP-MS - characterization of natural olivine standards for matrix-matched calibration and application to mantle peridotites.Chemical Geology, Vol. 524, pp. 136-157.Mantleperidotite

Abstract: The trace element composition of olivine is becoming increasingly important in petrological studies due to the ubiquity of olivine in the Earth's upper mantle and in primitive magmatic rocks. The LA-ICP-MS method allows for the routine analysis of trace elements in olivine to sub-ppm levels, but a major drawback of this method is the lack of knowledge about possible downhole fractionation effects when non matrix-matched calibration is used. In this contribution, we show that matrix-matched (i.e., olivine-based) calibration is preferable for small laser spot sizes (<100??m) due to significant laser-induced inter-element fractionation between olivine and commonly used silicate glass calibration materials, e.g., NIST SRM 612, GSD-1G and BHVO-2G. As a result, we present two Mg-rich natural olivine standards (355OL and SC-GB) that have been characterized by independent methods (EPMA, solution ICP-MS), and by LA-ICP-MS in four different laboratories. These natural olivines have been used 1) as primary standards for the matrix-matched calibration of olivine samples for most elements of interest (e.g., Li, Na, Al, P, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn), and 2) as secondary standards to assess the accuracy of results. Comparison of olivine- and silicate glass-calibrated results for natural peridotitic olivine reveals that matrix-matched calibration is essential when using small laser spot sizes (<100??m) in order to mitigate downhole fractionation effects for certain elements, especially Na, P, Mn, Co, Ni and Zn. If matrix-matched calibration is not feasible, we recommend that spot sizes of ?100??m, laser fluence of ?4.0?J/cm2, and total laser shot counts of ?250 (e.g., 5?Hz repetition rate for 50?s) are used in order to minimize fractionation effects between olivine and silicate glass calibration materials. We demonstrate the applicability of matrix-matched calibration on olivine from a suite of different mantle peridotite xenoliths sampled by kimberlites and alkali basalts from on-craton and off-craton localities.
DS201910-2247
2019
Bussweiler, Y.Bussweiler, Y.Polymineralic inclusions in megacrysts as proxies for kimberlite melt evolution - a review.Minerals ( MDPI), Vol. 9, p. 530 - 20p.Mantlediamond inclusions

Abstract: Polymineralic inclusions in megacrysts have been reported to occur in kimberlites worldwide. The inclusions are likely the products of early kimberlite melt(s) which invaded the pre-existing megacryst minerals at mantle depths (i.e., at pressures ranging from 4 to 6 GPa) and crystallized or quenched upon emplacement of the host kimberlite. The abundance of carbonate minerals (e.g., calcite, dolomite) and hydrous silicate minerals (e.g., phlogopite, serpentine, chlorite) within polymineralic inclusions suggests that the trapped melt was more volatile-rich than the host kimberlite now emplaced in the crust. However, the exact composition of this presumed early kimberlite melt, including the inventory of trace elements and volatiles, remains to be more narrowly constrained. For instance, one major question concerns the role of accessory alkali-halogen-phases in polymineralic inclusions, i.e., whether such phases constitute a common primary feature of kimberlite melt(s), or whether they become enriched in late-stage differentiation processes. Recent studies have shown that polymineralic inclusions react with their host minerals during ascent of the kimberlite, while being largely shielded from processes that affect the host kimberlite, e.g., the assimilation of xenoliths (mantle and crustal), degassing of volatiles, and secondary alteration. Importantly, some polymineralic inclusions within different megacryst minerals were shown to preserve fresh glass. A major conclusion of this review is that the abundance and mineralogy of polymineralic inclusions are directly influenced by the physical and chemical properties of their host minerals. When taking the different interactions with their host minerals into account, polymineralic inclusions in megacrysts can serve as useful proxies for the multi-stage origin and evolution of kimberlite melt/magma, because they can (i) reveal information about primary characteristics of the kimberlite melt, and (ii) trace the evolution of kimberlite magma on its way from the upper mantle to the crust.
DS202002-0197
2019
Bussweiler, Y.Krebs, M.Y., Pearson, D.G., Fagan, A.J., Bussweiler, Y., Sarkar, C.The application of trace elements and Sr-Pb isotopes to dating and tracing ruby formation: the Aappaluttoq deposit, SW Greenland.Chemical Geology, Vol. 523, pp. 42-58.Europe, Greenlandruby

Abstract: Trace element characteristics of rubies from the Aappaluttoq deposit, SW Greenland, were measured using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), laser ablation - inductively coupled plasma-time of flight-mass spectrometry (LA-ICP-TOF-MS) and offline laser ablation followed by solution ICP-MS. LA-ICP-TOF-MS - applied to rubies for the first time - effectively maps trace element spatial variation in these gems. With the exception of a small number of elements that can substitute for Al3+ in the crystal structure (e.g., Ti, Fe, V, Cr, Mg), trace element mapping clearly demonstrates that most elements such as Th, U, Sr and Rb are hosted in mineral and fluid inclusions or are present along fractures. Primitive mantle normalized trace element patterns show characteristics that are broadly correlative to mineral inclusions within the analysed rubies. These minerals include rutile (enrichment of HFSE over LREE, high Ta/Nb and Hf/Zr ratios and low Th/U ratios), phlogopite (enrichment in Rb and Ba and positive Sr anomalies), and zircon (extreme enrichment in Zr-Hf, U and Th, HREE enrichment over LREE and positive Ce anomalies). The sample suite analysed here is derived from a bulk sample of ore composed of three different rock types (sapphirine-gedrite, leucogabbro and phlogopitite). Two different populations of ruby were identified at Aappaluttoq; these can be defined on the basis of their different V content within the corundum lattice. Therefore, V content may be able to geochemically define rubies from different host rocks within the same deposit. Using offline laser ablation followed by thermal ionization mass spectrometry (TIMS) we measured the radiogenic isotope compositions in ruby for the first time. A Pb-Pb isochron age of 2686 +300/?74?Ma, was defined for gem formation at Aappaluttoq. We believe that this is the first ever direct age determined on a ruby suite, independent of associated minerals, derived by bulk sampling sub-micron to micron sized inclusions in the corundum lattice. This age likely reflects the re-crystallization and re-setting of the ruby (and its U-Pb system) during the Neoarchean in SW Greenland, due to regional granulite to upper-amphibolite facies metamorphism.
DS202009-1657
2020
Bussweiler, Y.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
Bussweiler, Y.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.
DS202104-0588
2021
Bussweiler, Y.Liu, Z., Shea, J., Foley, S., Bussweiler, Y., Rohrbach, A., Klemme, S., BerndtClarifying source assemblages and metasomatic agents for basaltic rocks in eastern Australia using olivine phenocryst compositions. Basanites, melilititesLithos, in press available, 74p. PdfAustraliametasomatism

Abstract: Many Cenozoic basaltic rocks in Eastern Australia exhibit an age-progressive trend from north to south, leading to the suggestion that one or more mantle plumes passed beneath the Australian plate. Trace element patterns indicate that the source regions have been metasomatised by infiltrating melts, but the source rock assemblages have never been closely identified. Here, trace element analyses of olivine and whole rock geochemistry for several occurrences in New South Wales (Bingara-Inverell, Dubbo, Barrington and Ebor) are combined to characterize the mineralogy of the source and identify the nature of the melts that caused the metasomatic enrichment. According to Ni/Mg against Mn/Fe and Zn/Fe ratios in olivines, Zn/Fe and FC3MS (FeOT/CaO-3*MgO/SiO2) parameters in whole rocks, tholeiite, alkali basalt, and basanite rich in olivine xenocrysts from Dubbo were derived from pyroxenite-dominated mixed source, mixed pyroxenite+peridotite source, and peridotite-dominated source, respectively. Similarly, basalts from Ebor and Bingara/Inverell are suggested to originate from a mixed pyroxenite+peridotite source based on their high FC3MS values. In contrast, the source of basanite and picrobasalt from Barrington was peridotite with little pyroxenite. High Li and Zn in olivines, high P2O5/TiO2 and Zr/Hf at low Ti/Eu in whole rocks illustrate that the pyroxenite sources of basanites from Bingara/Inverell, Barrington and Dubbo resulted from variable degrees of carbonatitic metasomatism. Partial melting of peridotite metasomatised by carbonatite melts at around the spinel-garnet peridotite transition depth produced basalts and basanites from Dubbo, Barrington, Ebor, Bingara/Inverell and Buckland (Queensland). Carbonatitic metasomatism is widespread in the eastern Australian mantle lithosphere, occurring seaboard of a ledge between thick lithosphere beneath the Australian continent that stretches from Queensland, through New South Wales to Victoria.
DS202108-1309
2021
Bussweiler, Y.Shaikh, A.M., Tappe, S., Bussweiler, Y., Brown, T.J., Vollmer, C.Origins of olivine in Earth;s youngest kimberlite: Igwisi Hills volcanoes, Tanzanian craton.Contributions to Mineralogy and Petrology, 10.1007/s00410-021-01816-2 Africa, Tanzaniadeposit - Igwisi Hills
DS202110-1614
2021
Bussweiler, Y.Forster, M.W., Bussweiler, Y., Prelevic, D., Daczko, N.R., Buhre, S., Mertz-Kraus, R., Foley, S.F.Sediment-peridotite reaction controls fore-arc metasomatism and arc magma geochemical signatures.Geosciences MDPI, Vol. 11, 372, 24p. PdfMantlesubduction

Abstract: Subduction of oceanic crust buries an average thickness of 300-500 m of sediment that eventually dehydrates or partially melts. Progressive release of fluid/melt metasomatizes the fore-arc mantle, forming serpentinite at low temperatures and phlogopite-bearing pyroxenite where slab surface reaches 700-900 °C. This is sufficiently high to partially melt subducted sediments before they approach the depths where arc magmas are formed. Here, we present experiments on reactions between melts of subducted sediments and peridotite at 2-6 GPa/750-1100 °C, which correspond to the surface of a subducting slab. The reaction of volatile-bearing partial melts derived from sediments with depleted peridotite leads to separation of elements and a layered arrangement of metasomatic phases, with layers consisting of orthopyroxene, mica-pyroxenite, and clinopyroxenite. The selective incorporation of elements in these metasomatic layers closely resembles chemical patterns found in K-rich magmas. Trace elements were imaged using LA-ICP-TOFMS, which is applied here to investigate the distribution of trace elements within the metasomatic layers. Experiments of different duration enabled estimates of the growth of the metasomatic front, which ranges from 1-5 m/ky. These experiments explain the low contents of high-field strength elements in arc magmas as being due to their loss during melting of sedimentary materials in the fore-arc.
DS202201-0020
2021
Bussweiler, Y.Kargin, A., Bussweiler, Y., Nosova, A., Sazonova, L., Berndt, J., Klemme, S.Titanium-rich metasomatism in the lithospheric mantle beneath the Arkangelsk diamond province, Russia: insights from ilemenite-bearing xenoliths with HP-HT reaction experiments.Contributions to Mineralogy and Petrology, Vol. 176, 12, Russia, Arlangelskdeposit - Grib

Abstract: To provide new insights into the interaction of ultramafic alkaline melts with the subcontinental lithospheric mantle, we present results of a petrographical-mineralogical study of ilmenite-bearing mantle xenoliths from the Grib kimberlite, Archangelsk, Russia along with results from reaction experiments between harzburgite and Fe-Ti bearing carbonate-silicate melts similar to aillikite. The compositions of orthopyroxene, ilmenite and garnet from our mantle xenoliths are similar to compositions of minerals of the low-Cr megacryst suite from different kimberlite occurrences worldwide including the Grib kimberlite as well as minerals from sheared lherzolite xenoliths captured by the Grib kimberlite. This suggests that ilmenite-bearing xenoliths, megacrysts, and sheared lherzolite xenoliths could have a common origin and/or formed under similar conditions. The reaction experiments were performed at 4 GPa and 1200 °C with varying proportions of aillikite (0, 10, and 50 wt%) that reacted with harzburgite. The experimental runs with 10% and 50% aillikite resulted in two layers within the capsule, with an ilmenite-bearing reaction zone at the contact between aillikite and harzburgite, and an ilmenite-free zone characterized by higher garnet and clinopyroxene abundances. An increase of aillikite melt is directly correlated with increasing TiO2 and decreasing Cr2O3 contents and Mg# values in the mineral phases, most significantly for pyroxenes. Overall, the experiments produce a chemical gradation of minerals from Cr-rich (Fe-Ti-poor) to Cr-poor (Fe-Ti-rich) which is strikingly similar to the chemical gradation observed in minerals from natural mantle-derived xenoliths from kimberlites. In summary, comparison of our experimental data with natural samples indicates possible links between the generation of megacrysts and Ti-rich metasomatism of the lithospheric mantle by ultramafic alkaline (aillikite-related) melts and their possible evolution towards kimberlites. Our results illustrate the importance of melt-rock ratios in generating the mineralogical and chemical diversity in mantle xenolith suites.
DS201708-1608
2017
Bussweiller, Y.Bussweiller, Y.Cr-rich megacrysts of clinopyroxene and garnet from Lac de Gras kimberlites, Slave craton, Canada - implications for the origin of clinopyroxenes and garnet in cratonic peridotites.11th. International Kimberlite Conference, OralCanada, Northwest Territoriesdeposit - Lac de Gras
DS201708-1609
2017
Bussweiller, Y.Bussweiller, Y.Evolution of calcite-bearing kimberlites by melt-rock reaction - evidence from polmineralic inclusions within clinopyroxene and garnet megacrysts from Lac de Gras kimberlites, Canada.11th. International Kimberlite Conference, PosterCanada, Northwest Territoriesdeposit - Lac de Gras

Abstract: Megacrystic (>1 cm) clinopyroxene (Cr-diopside) and garnet (Cr-pyrope) xenocrysts within kimberlites from Lac de Gras (Northwest Territories, Canada) contain fully crystallized melt inclusions. These `polymineralic inclusions' have previously been interpreted to form by necking down of melts at mantle depths. We present a detailed petrographical and geochemical investigation of polymineralic inclusions and their host crystals to better understand how they form and what they reveal about the evolution of kimberlite melt. Genetically, the megacrysts are mantle xenocrysts with peridotitic chemical signatures indicating an origin within the lithospheric mantle (for the Cr-diopsides studied here ~4.6 GPa, 1015 °C). Textural evidence for disequilibrium between the host crystals and their polymineralic inclusions (spongy rims in Cr-diopside, kelyphite in Cr-pyrope) is consistent with measured Sr isotopic disequilibrium. The preservation of disequilibrium establishes a temporal link to kimberlite eruption. In Cr-diopsides, polymineralic inclusions contain phlogopite, olivine, chromite, serpentine, and calcite. Abundant fluid inclusion trails surround the inclusions. In Cr-pyropes, the inclusions additionally contain Al-spinel, clinopyroxene, and dolomite. The major and trace element compositions of the inclusion phases are generally consistent with the early stages of kimberlite differentiation trends. Extensive chemical exchange between the host phases and the inclusions is indicated by enrichment of the inclusions in major components of the host crystals, such as Cr2O3 and Al2O3. This chemical evidence, along with phase equilibria constraints, supports the proposal that the inclusions within Cr-diopside record the decarbonation reaction: dolomitic melt + diopside ? forsterite + calcite + CO2, yielding the observed inclusion mineralogy and producing associated (CO2-rich) fluid inclusions. Our study of polymineralic inclusions in megacrysts provides clear mineralogical and chemical evidence for an origin of kimberlite that involves the reaction of high-pressure dolomitic melt with diopside-bearing mantle assemblages producing a lower-pressure melt that crystallizes a calcite-dominated assemblage in the crust.
DS201804-0714
2018
Bussweiller, Y.Korolev, N.M., Kopylova, M., Bussweiller, Y., Pearson, D.G., Gurney, J., Davidson, J.The uniquely high temperature character of Culli nan diamonds: a signature of the Bushveld mantle plume?Lithos, Vol. 304, pp. 362-373.Africa, South Africadeposit - Cullinan

Abstract: The mantle beneath the Cullinan kimberlite (formerly known as "Premier") is a unique occurrence of diamondiferous cratonic mantle where diamonds were generated contemporaneously and shortly following a mantle upwelling that led to the formation of a Large Igneous Province that produced the world's largest igneous intrusion - the 2056?Ma Bushveld Igneous Complex (BIC). We studied 332 diamond inclusions from 202 Cullinan diamonds to investigate mantle thermal effects imposed by the formation of the BIC. The overwhelming majority of diamonds come from three parageneses: (1) lithospheric eclogitic (69%), (2) lithospheric peridotitic (21%), and (3) sublithospheric mafic (9%). The lithospheric eclogitic paragenesis is represented by clinopyroxene, garnet, coesite and kyanite. Main minerals of the lithospheric peridotitic paragenesis are forsterite, enstatite, Cr-pyrope, Cr-augite and spinel; the sublithospheric mafic association includes majorite, CaSiO3 phases and omphacite. Diamond formation conditions were calculated using an Al-in-olivine thermometer, a garnet-clinopyroxene thermometer, as well as majorite and Raman barometers. The Cullinan diamonds may be unique on the global stage in recording a cold geotherm of 40?mW/m2 in cratonic lithosphere that was in contact with underlying convecting mantle at temperatures of 1450-1550?°C. The studied Cullinan diamonds contain a high proportion of inclusions equilibrated at temperatures exceeding the ambient 1327?°C adiabat, i.e. 54% of eclogitic diamonds and 41% of peridotitic diamonds. By contrast, ? 1% of peridotitic diamond inclusions globally yield equally high temperatures. We propose that the Cullinan diamond inclusions recorded transient, slow-dissipating thermal perturbations associated with the plume-related formation of the ~2?Ga Bushveld igneous province. The presence of inclusions in diamond from the mantle transition zone at 300-650?km supports this view. Cullinan xenoliths indicative of the thermal state of the cratonic lithosphere at ~1.2?Ga are equilibrated at the relatively low temperatures, not exceeding adiabatic. The ability of diamonds to record super-adiabatic temperatures may relate to their entrainment from the deeper, hotter parts of the upper mantle un-sampled by the kimberlite in the form of xenoliths or their equilibration in a younger lithosphere after a decay of the thermal disturbance.
DS1995-0246
1995
Bussy, F.Bussy, F., Krogh, T.E., Wardle, R.J.Lat Labradorian, metamorphism and anorthosite granitoid intrusion, Cape Caribou River allochthon, GrenvilleCanadian Journal of Earth Sciences, Vol. 32, pp. 1411-25.Quebec, Ungava, LabradorMealy Mountains, metamorphism
DS2003-1432
2003
Bussy, F.Von Raumer, J.F., Stampfli, G.M., Bussy, F.Gondwana derived microcontinents - the constituents of the Variscan and AlpineTectonophysics, Vol. 365, 1-4, pp.7-22.EuropeOrogenesis
DS2003-1433
2003
Bussy, F.Von Raumer, J.F., Stampfli, G.M., Bussy, F.Gondwana derived microcontinents - the constituents of the Variscan and AlpineTectonophysics, Vol. 365, 1-4, pp. 7-22.Tectonics
DS200412-2064
2003
Bussy, F.Von Raumer, J.F., Stampfli, G.M., Bussy, F.Gondwana derived microcontinents - the constituents of the Variscan and Alpine collisional orogens.Tectonophysics, Vol. 365, 1-4, pp.7-22.EuropeOrogenesis
DS2003-1118
2003
Bustamante, R.H.Pulfrich, A., Parkins, C.A., Branch, G.M., Bustamante, R.H., Velasquez, C.R.The effects of sediment deposits from Namibian diamond mines on intertidal andAquatic Conservation, Vol. 13, 3, pp. 257-78. Ingenta 1032281872NamibiaEnvironment
DS200412-1600
2003
Bustamante, R.H.Pulfrich, A., Parkins, C.A., Branch, G.M., Bustamante, R.H., Velasquez, C.R.The effects of sediment deposits from Namibian diamond mines on intertidal and subtidal reefs and rock lobster populations.Aquatic Conservation, Vol. 13, 3, pp. 257-78. Ingenta 1032281872Africa, NamibiaEnvironment
DS1984-0609
1984
Bustin, R.M.Riedinger, C.L., Bustin, R.M., Rouse, G.E.New evidence for the chronology of the Eurekan Orogeny from south central Ellesmere island.Canadian Journal of Earth Sciences, Vol. 21, pp. 1286-95.Northwest Territories, Ellesmere IslandEurekan Orogeny, Geochronology
DS201212-0485
2012
Buta Neto, A.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
Buta Nto, A.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
DS1960-0223
1962
Butakova, E.L.Butakova, E.L., Egorov, L.S.The Kimberlitic Bodies and the Structure of the Chadobets Uplift.Report KRASNOYARSK STATE University, No. 3, PP. LL7-L30.RussiaBlank
DS202009-1614
2020
Butch, C.J.Brovarone, A.V., Butch, C.J., Ciappa, A., Cleaves, H.J., Elmaleh, A., Faccenda, M., Feineman, M., Hermann, J., Nestola, F., Cordone, A., Giovannelli., D.Let there be water: how hydration/dehydration reactions accompany key Earth and life processes.American Mineralogist, Vol. 105, pp. 1152-1160. pdfMantlecarbon

Abstract: Water plays a key role in shaping our planet and making life possible. Given the abundance of water on Earth's surface and in its interior, chemical reactions involving water, namely hydration and dehydration reactions, feature prominently in nature and are critical to the complex set of geochemical and biochemical reactions that make our planet unique. This paper highlights some fundamental aspects of hydration and dehydration reactions in the solid Earth, biology, and man-made materials, as well as their connections to carbon cycling on our planet.
DS1998-0170
1998
Butcher, A.R.Brown, J.W., Butcher, A.R.Textural and petrological variation within the Crater facies kimberlite bodies of the Fort a la Corne Province7th International Kimberlite Conference Abstract, pp. 103-4.SaskatchewanPetrography, Classification
DS2000-0130
2000
Butcher, R.J.Butcher, R.J.Hazards associated with the mining of Diamondiferous pipesThe Canadian Mining and Metallurgical Bulletin (CIM Bulletin) ., Vol. 93, No. 1037, Feb. pp. 65-67.South AfricaMining - underground, methods
DS201604-0639
2015
Buter, E.Zwaan, J.C., Buter, E., Mertz-Kraus, R., Kane, R.E.Alluvial sapphires from Montana: inclusions, geochemistry, and indications of a metasomatic origin. Gems & Gemology, Vol. 51, 4, winter pp. 370-391.United States, MontanaSapphires

Abstract: Although the source rocks of alluvial sapphires in Montana have never been discovered, inclusions and geochemistry of material from this location may give clues to their original source. Mineral inclusions in alluvial Montana sapphires, mainly from Rock Creek, were identified and compared with existing data. Topaz was a remarkable find in one of these samples; other newly identified mineral inclusions in Montana sapphire were allanite, anatase, chalcopyrite, and monazite. Together with the presence of calcium-rich plagioclase, alkali-feldspar, apatite, barite, phlogopite, a pyrochlore-group mineral previously called uranpyrochlore, and chromite/spinel, these inclusions may reflect a metasomatic origin for the sapphires. This is supported by their chemical composition, which largely coincides with sapphires of plumasitic/metasomatic origin. The secondary Montana sapphires analyzed in this study are characterized by mean values of Fe (4686 ppmw), Ti (58 ppmw), Ga (51 ppmw), Mg (35 ppmw), and Cr (21 ppmw). Fe-Mg-Ga ratios help to distinguish them from sapphires with overlapping properties, such as those from Umba, Tanzania, and Rio Mayo, Colombia.
DS1992-0197
1992
Butin, V.V.Butin, V.V.Geological position of eclogitesProceedings of the 29th International Geological Congress. Held Japan August 1992, Vol. 2, abstract p. 590RussiaEclogites
DS200512-0398
2004
Butler, A.Hanne, D., White, N., Butler, A., Jones, S.Phanerozoic vertical motions of Hudson Bay.Canadian Journal of Earth Sciences, Vol. 41, 10, Oct. pp. 1181-1200.Canada, Ontario, ManitobaTectonics
DS1988-0096
1988
Butler, A.R.Butler, A.R., Wyatt, P.A.H.Hannay diamondsChemistry Britt, Vol. 24, No. 5, May pp. 462-463GlobalBlank
DS1994-0485
1994
Butler, G.M.Edgar, A.D., Pizzolato, L.A., Butler, G.M.Petrology of the ultramafic lamprophyre and associated rocks at CoralRapids, Abitibi River, Ontario.Canadian Journal of Earth Sciences, Vol. 31, No. 8, August, pp. 1325-1334.OntarioLamprophyres, alkaline, Deposit -Coral Rapids district
DS2000-0131
2000
Butler, H.Butler, H.Reclamation strategies at the Ekati diamond mine, northwest Territories28th. Yellowknife Geoscience Forum, p. 13-14.abstractNorthwest TerritoriesReclamation - environment, Deposit - Ekati
DS2001-0152
2001
Butler, H.Butler, H., Martens, H.Northern latitudes mining reclamation workshop... abstract29th. Yellowknife Geoscience Forum, Nov. 21-23, abstract p.9.Northwest TerritoriesMine reclamation - mine tailings, Deposit - Ekati
DS200612-0894
2006
Butler, H.McKay, S., Funk, W., Rimbey, S., Butler, H.Computer simulation model for determining reclamation liability costs of the EKATI diamond mine in the Northwest Territories, Canada.Journal of Cleaner Production, Vol. 14, 12-13, pp. 1096-1100. Ingenta 1062062956Canada, Northwest TerritoriesMining, reclamation
DS201312-0049
2013
Butler, H.Bailey, B.L., Norlund, K.L., Wen, M., Novy, l., Butler, H.Ekati diamond mine: Long Lake containment facility pore water geochemistry.2013 Yellowknife Geoscience Forum Abstracts, p. 9. abstractCanada, Northwest TerritoriesDeposit - Ekati
DS201610-1869
2016
Butler, I.B.Hastie, A.R., Fitton, J.G., Bromiley, G.D., Butler, I.B., Oding, W.A.The origin of Earth's first continents and the onset of plate tectonics.Geology, Vol. 44, 10, pp. 855-858.MantleSubduction

Abstract: The growth and recycling of continental crust has resulted in the chemical and thermal modification of Earth's mantle, hydrosphere, atmosphere, and biosphere for ?4.0 b.y. However, knowledge of the protolith that gave rise to the first continents and whether the environment of formation was a subduction zone still remains unknown. Here, tonalite melts are formed in high P-T experiments in which primitive oceanic plateau starting material is used as an analogue for Eoarchean (3.6-4.0 Ga) oceanic crust generated at early spreading centers. The tonalites are produced at 1.6-2.2 GPa and 900-950 °C and are mixed with slab-derived aqueous fluids to generate melts that have compositions identical to that of Eoarchean continental crust. Our data support the idea that the first continents formed at ca. 4 Ga and subsequently, through the subduction and partial melting of ?30-45-km-thick Eoarchean oceanic crust, modified Earth's mantle and Eoarchean environments and ecosystems.
DS201707-1349
2017
Butler, I.B.McDonald, I., Hughes, H.S.R., Butler, I.B., Harris, J.W., Muir, D.Homogenization of sulphide inclusions within diamonds: a new approach to diamond inclusion geochemistry.Geochimica et Cosmochimica Acta, available in press 23p.Africa, Botswanadeposit - Orapa

Abstract: Base metal sulphide (BMS) inclusions in diamonds provide a unique insight into the chalcophile and highly siderophile element composition of the mantle. Entombed within their diamond hosts, these provide a more robust (closed system) sample, from which to determine the trace element, Re-Os and S-isotopic compositions of the mantle than mantle xenoliths or orogenic peridotites, as they are shielded from alteration during ascent to the Earth’s crust and subsequent surface weathering. However, at temperatures below 1100 °C some BMS inclusions undergo subsolidus re-equilibration from an original monosulphide solid solution (Mss) and this causes fractionation of the major and trace elements within the inclusions. Thus to study the subjects noted above, current techniques require the entire BMS inclusion to be extracted for analyses. Unfortunately, ‘flaking’ of inclusions during break-out is a frequent occurrence and hence the risk of accidentally under-sampling a portion of the BMS inclusion is inherent in current practices. This loss may have significant implications for Re-Os isotope analyses where incomplete sampling of a Re-rich phase, such as chalcopyrite that typically occurs at the outer margins of BMS inclusions, may induce significant bias in the Re-Os and 187Os/188Os measurements and resulting model and isochron ages. We have developed a method for the homogenisation of BMS inclusions in diamond prior to their break-out from the host stone. Diamonds are heated to 1100 °C and then quenched to chemically homogenise any sulphide inclusions for both major and trace elements. Using X-ray Computed Microtomography (µCT) we determine the shape and spatial setting of multiple inclusions within a host stone and crucially show that the volume of a BMS inclusion is the same both before and after homogenisation. We show that the homogenisation process significantly reduces the inherent variability of in situ analysis when compared with unhomogenised BMS, thereby widening the scope for multiple methods for quantitative analysis, even on ‘flakes’ of single BMS inclusions. Finally we show that the trace elements present in peridotite (P-type) and eclogitic (E-type) BMS are distinct, with P-type diamonds having systematically higher total platinum-group element (particularly Os, Ir, Ru) and Te and As concentrations. These distinctions suggest that the PGE and semi-metal budgets of mantle-derived partial melts will be significantly dependent upon the type(s) and proportions of sulphides present in the mantle source.
DS201709-2030
2017
Butler, I.B.McDonald, I., Hughes, H.S.R., Butler, I.B., Harris, J.W., Muir, D.Homogenisation of sulphide inclusions within diamonds: a new approach to diamond inclusion geochemistry.Geochimica et Cosmochimica Acta, in press available, 23p.Technologydiamond inclusions

Abstract: Base metal sulphide (BMS) inclusions in diamonds provide a unique insight into the chalcophile and highly siderophile element composition of the mantle. Entombed within their diamond hosts, these provide a more robust (closed system) sample, from which to determine the trace element, Re-Os and S-isotopic compositions of the mantle than mantle xenoliths or orogenic peridotites, as they are shielded from alteration during ascent to the Earth’s crust and subsequent surface weathering. However, at temperatures below 1100 °C some BMS inclusions undergo subsolidus re-equilibration from an original monosulphide solid solution (Mss) and this causes fractionation of the major and trace elements within the inclusions. Thus to study the subjects noted above, current techniques require the entire BMS inclusion to be extracted for analyses. Unfortunately, ‘flaking’ of inclusions during break-out is a frequent occurrence and hence the risk of accidentally under-sampling a portion of the BMS inclusion is inherent in current practices. This loss may have significant implications for Re-Os isotope analyses where incomplete sampling of a Re-rich phase, such as chalcopyrite that typically occurs at the outer margins of BMS inclusions, may induce significant bias in the Re-Os and 187Os/188Os measurements and resulting model and isochron ages. We have developed a method for the homogenisation of BMS inclusions in diamond prior to their break-out from the host stone. Diamonds are heated to 1100 °C and then quenched to chemically homogenise any sulphide inclusions for both major and trace elements. Using X-ray Computed Microtomography (µCT) we determine the shape and spatial setting of multiple inclusions within a host stone and crucially show that the volume of a BMS inclusion is the same both before and after homogenisation. We show that the homogenisation process significantly reduces the inherent variability of in situ analysis when compared with unhomogenised BMS, thereby widening the scope for multiple methods for quantitative analysis, even on ‘flakes’ of single BMS inclusions. Finally we show that the trace elements present in peridotite (P-type) and eclogitic (E-type) BMS are distinct, with P-type diamonds having systematically higher total platinum-group element (particularly Os, Ir, Ru) and Te and As concentrations. These distinctions suggest that the PGE and semi-metal budgets of mantle-derived partial melts will be significantly dependent upon the type(s) and proportions of sulphides present in the mantle source.
DS201710-2246
2017
Butler, I.B.McDonald, I., Hughes, H.S.R., Butler, I.B., Harris, J.W., Muir, D.Homogenization of sulphide inclusions within diamonds: a new approach to diamond inclusion geochemistry.Geochimica et Cosmochimica Acta, Vol. 216, pp. 335-357.Technologydiamond inclusions - microtomography

Abstract: Base metal sulphide (BMS) inclusions in diamonds provide a unique insight into the chalcophile and highly siderophile element composition of the mantle. Entombed within their diamond hosts, these provide a more robust (closed system) sample, from which to determine the trace element, Re-Os and S-isotopic compositions of the mantle than mantle xenoliths or orogenic peridotites, as they are shielded from alteration during ascent to the Earth’s crust and subsequent surface weathering. However, at temperatures below 1100 °C some BMS inclusions undergo subsolidus re-equilibration from an original monosulphide solid solution (Mss) and this causes fractionation of the major and trace elements within the inclusions. Thus to study the subjects noted above, current techniques require the entire BMS inclusion to be extracted for analyses. Unfortunately, ‘flaking’ of inclusions during break-out is a frequent occurrence and hence the risk of accidentally under-sampling a portion of the BMS inclusion is inherent in current practices. This loss may have significant implications for Re-Os isotope analyses where incomplete sampling of a Re-rich phase, such as chalcopyrite that typically occurs at the outer margins of BMS inclusions, may induce significant bias in the Re-Os and 187Os/188Os measurements and resulting model and isochron ages. We have developed a method for the homogenisation of BMS inclusions in diamond prior to their break-out from the host stone. Diamonds are heated to 1100 °C and then quenched to chemically homogenise any sulphide inclusions for both major and trace elements. Using X-ray Computed Microtomography (µCT) we determine the shape and spatial setting of multiple inclusions within a host stone and crucially show that the volume of a BMS inclusion is the same both before and after homogenisation. We show that the homogenisation process significantly reduces the inherent variability of in situ analysis when compared with unhomogenised BMS, thereby widening the scope for multiple methods for quantitative analysis, even on ‘flakes’ of single BMS inclusions. Finally we show that the trace elements present in peridotite (P-type) and eclogitic (E-type) BMS are distinct, with P-type diamonds having systematically higher total platinum-group element (particularly Os, Ir, Ru) and Te and As concentrations. These distinctions suggest that the PGE and semi-metal budgets of mantle-derived partial melts will be significantly dependent upon the type(s) and proportions of sulphides present in the mantle source.
DS201906-1338
2019
Butler, I.B.Price, D.L., Butler, I.B., Ngwenya, B.T., Kirstein, L.A.Crystallisation pathways of mixed La and Nd carbonates.3rd International Critical Metals Meeting held Edinburgh, 1p. Abstract p. 64.Chinadeposit - Bayan Obo
DS1989-0196
1989
Butler, J.Butler, J.Chemical vapor deposition of diamondsDiamond Workshop, International Geological Congress, July 15-16th. editors, pp. 11-13. AbstractGlobalDiamond morphology, CVD.
DS201012-0215
2010
Butler, J.Gaillou, E., Rost, D., Post, J., Butler, J.Quantifying boron in natural type IIb blue diamonds.Goldschmidt 2010 abstracts, abstractTechnologyDiamond morphology
DS1989-0238
1989
Butler, J.E.Celii, F.G., Butler, J.E.Hydrogen-atom detection in the filament assisted diamond depositionenvironmentAppl. Phys. Letters, Vol. 54, No. 11, March 13, pp. 1031-1033GlobalDiamond morphology, Diamond synthesis
DS1989-0581
1989
Butler, J.E.Hannssen, L.M., Carrington, W.A., Butler, J.E., Snail, K.A.Diamond synthesis using an oxygen acetylene torchMaterial Letters, Vol. 7, No. 7-8, Dec. pp. 289-292GlobalDiamond synthesis
DS1991-0243
1991
Butler, J.E.Celii, F.G., Butler, J.E.Diamond chemical vapour depositionAnnual Review of Physical Chemistry, Vol. 42, November ppGlobalCVD., Review - diamond chemical vapour deposition
DS1998-0193
1998
Butler, J.E.Butler, J.E.Chemical vapor deposition of diamond: synthesis in partial vacuumsIma 17th. Abstract Vol., p. A11. abstractGlobalCDV, Diamond synthesis
DS2003-1450
2003
Butler, J.E.Wang, W., Moses, T., Linares, R.C., Shigley, J.E., Hall, M., Butler, J.E.Gem quality synthetic diamonds grown by a chemical vapor deposition ( CVD)Gems & Gemology, Vol. 39, Winter,pp. 268-283.GlobalBlank
DS200412-2083
2003
Butler, J.E.Wang, W., Moses, T., Linares, R.C., Shigley, J.E., Hall, M., Butler, J.E.Gem quality synthetic diamonds grown by a chemical vapor deposition ( CVD) method.Gems & Gemology, Vol. 39, Winter,pp. 268-283.TechnologySynthetic diamond
DS200612-0201
2006
Butler, J.E.Butler, J.E.Growth of CVD synthetic diamond.GIA Gemological Research Conference abstract volume, Held August 26-27, p. 34. 1/2p.TechnologyDiamond synthesis
DS200612-0363
2006
Butler, J.E.Eaton-Magana, S., Post, J.E., Freitas, J.A., Klein, P.B., Walters, R.A., Heaney, P.J, Butler, J.E.Luminescence of the Hope diamond and other blue diamonds.GIA Gemological Research Conference abstract volume, Held August 26-27, p. 32. 1/2p.TechnologySpectroscopy
DS200712-0283
2006
Butler, J.E.Eaton-Magana, S., Post, J.E., Walters, R.A., Heaney, P.J., Butler, J.E.Fluoresence of fancy color natural diamonds.Gems & Gemology, 4th International Symposium abstracts, Fall 2006, p.131-2. abstract onlyTechnologyDiamond colour - UV radiation
DS200812-0309
2008
Butler, J.E.Eaton-Magana, S., Post, J.E., Heaney, P.J., Frietas, J., Klein, P., Walters, R., Butler, J.E.Using phosphorescence as a fingerprint for the Hope and other blue diamonds.Geology, Vol. 36, 1, pp.TechnologyDiamond morphology
DS200812-0310
2007
Butler, J.E.Eaton-Magana, S., Post, J.E., Heaney, P.J., Walters, R.A., Breeding, C.M., Butler, J.E.Fluorescence spectra of colored diamonds using a rapid, mobile spectrometer.Gems & Gemology, Vol. 43, 4, Winter pp. 332-351.TechnologyType 1 a diamonds
DS201012-0214
2010
Butler, J.E.Gaillou, E., Post, J.E., Bassim, N.D., Zaitsev, A.M., Rose, T., Fries, M.D., Stroud, R.M., Steele, A., Butler, J.E.Spectroscopic and microscopic characterizations of color laminae in natural pink diamonds.Diamond and Related Materials, Vol. 19, 10, pp. 1207-1220.TechnologySpectroscopy
DS201012-0216
2010
Butler, J.E.Gaillou, E., Wang, W., Post, J.E., King, J.M., Butler, J.E., Collins, A.T., Moses, T.M.The Wittelsbach-Graff and Hope diamonds: not cut from the same rough.Gems & Gemology, Vol. 46, 2, pp. 80-88.TechnologyDiamonds notable
DS201112-0341
2011
Butler, J.E.Gaillou, E., Post, J.E., Butler, J.E.On the pecularities of Australian and Venezuelan pink diamonds: influence of the geologic settings.Goldschmidt Conference 2011, abstract p.882.Australia, South America, VenezuelaArgyle, Santa Elena, high thermal events
DS201212-0225
2012
Butler, J.E.Gaillou, E.,Post, J.E., Rost, D., Butler, J.E.Boron in natural type 11b blue diamonds: chemical and spectroscopic measurements.American Mineralogist, Vol. 97, pp. 1-18.TechnologyBlue diamond
DS201412-0261
2014
Butler, J.E.Galillou, E., Post, J.E., Steele, A., Butler, J.E.Constrains on highly strained pink diamonds by high spatial resolution FTIR and Raman mapping.Geological Society of America Conference Vancouver Oct. 19-22, 1p. AbstractTechnologyPink diamond colour
DS201503-0144
2015
Butler, J.E.Gaillou, E., Post, J.E., Byne, K.S., Butler, J.E.Study of the Blue Moon diamond. ( from Cullinan)Gems & Gemology, Vol. 50, 4, winter 2014, 9p.Africa, South AfricaDiamonds notable

Abstract: The Blue Moon diamond, discovered in January 2014 at the historic Cullinan mine in South Africa, is of significance from both trade and scientific perspectives. The 29.62 ct rough yielded a 12.03 ct Fancy Vivid blue, Internally Flawless gem. The authors were provided the opportunity to study this rare diamond at the Smithsonian Institution before it went on exhibit at the Natural History Museum of Los Angeles County. Infrared spectroscopy revealed that the amount of uncompensated boron in the diamond was 0.26 ± 0.04 ppm, consistent with measurements of several large type IIb blue diamonds previously studied. After exposure to short-wave ultraviolet light, the Blue Moon displayed orange-red phosphorescence that remained visible for up to 20 seconds. This observation was surprising, as orange-red phosphorescence is typically associated with diamonds of Indian origin, such as the Hope and the Wittelsbach-Graff. Time-resolved phosphorescence spectra exhibited peaks at 660 and 500 nm, typical for natural type II blue diamonds. As with most natural diamonds, the Blue Moon showed strain-induced birefringence.
DS201608-1434
2016
Butler, J.E.Post, J.E., Gaillou, E., Butler, J.E., Byrne, K.S.Investigations into luminescence properties and compositions of colored diamonds.GSA Annual Meeting, Abstract, 1p.TechnologyLuminescence

Abstract: The Smithsonian’s National Gem Collection includes the Hope Diamond and an assortment of other significant fancy-colored diamonds, providing a unique opportunity to conduct detailed and sustained studies on an unprecedented selection of these rare and valuable stones. We present an overview and recent results from our work on pink, blue and chameleon diamonds. Boron causes the blue color of the Hope Diamond and other type IIb diamonds, but scarcity, high value, and the low concentration of B has inhibited B analyses of natural IIb diamonds. We used FTIR and ToF-SIMS to measure concentrations and distributions of B in the Hope and other blue diamonds. ToF-SIMS analyses gave spot B concentrations as high as 8.4 ± 1.1 ppm for the Hope Diamond to less than 0.08 ppm in other blue diamonds and revealed strong zoning of B in some diamonds, which was confirmed by mapping using synchrotron FTIR. Boron is also responsible for the phosphorescence emissions of IIb diamonds, at 660 nm and 500 nm; the emissions are likely caused by donor-acceptor pair recombination processes involving B and other defects. Approximately 50 type I natural pink diamonds were compared using UV-Vis, FTIR, and CL spectroscopies. All stones exhibit pink color zoning, ~1µm thick [111] lamellae, in otherwise colorless diamond. The pink diamonds fall into two groups: 1) those from Argyle in Australia and Santa Elena in Venezuela, and 2) those from other localities. TEM imaging from FIB sections revealed that twinning is the likely mechanism by which plastic deformation is accommodated for the pink diamonds. The deformation creates new centers, including the one responsible for the pink color, which remains unidentified. The differences in the plastic deformation features for the two groups might correlate to the particular geologic conditions under which the diamonds formed. Fluorescence and thermoluminescence experiments on natural chameleon diamonds reveal that an emission band, peaking near 556nm, may be stimulated via a number of different mechanisms. We discuss the implications of our observations for the electronic structure of the 556nm-fluorescing defect center, and the connections to the unidentified color center responsible for chameleon color changes.
DS201610-1900
2016
Butler, J.E.Post, J.E., Gaillou, E., Butler, J.E., Byrne, K.S.Investigations into the luminescence properties and compositions of colored diamonds. ( blue and pink)GSA Annual Meeting, 1/2p. abstractTechnologyColoured diamonds

Abstract: The Smithsonian’s National Gem Collection includes the Hope Diamond and an assortment of other significant fancy-colored diamonds, providing a unique opportunity to conduct detailed and sustained studies on an unprecedented selection of these rare and valuable stones. We present an overview and recent results from our work on pink, blue and chameleon diamonds. Boron causes the blue color of the Hope Diamond and other type IIb diamonds, but scarcity, high value, and the low concentration of B has inhibited B analyses of natural IIb diamonds. We used FTIR and ToF-SIMS to measure concentrations and distributions of B in the Hope and other blue diamonds. ToF-SIMS analyses gave spot B concentrations as high as 8.4 ± 1.1 ppm for the Hope Diamond to less than 0.08 ppm in other blue diamonds and revealed strong zoning of B in some diamonds, which was confirmed by mapping using synchrotron FTIR. Boron is also responsible for the phosphorescence emissions of IIb diamonds, at 660 nm and 500 nm; the emissions are likely caused by donor-acceptor pair recombination processes involving B and other defects. Approximately 50 type I natural pink diamonds were compared using UV-Vis, FTIR, and CL spectroscopies. All stones exhibit pink color zoning, ~1µm thick [111] lamellae, in otherwise colorless diamond. The pink diamonds fall into two groups: 1) those from Argyle in Australia and Santa Elena in Venezuela, and 2) those from other localities. TEM imaging from FIB sections revealed that twinning is the likely mechanism by which plastic deformation is accommodated for the pink diamonds. The deformation creates new centers, including the one responsible for the pink color, which remains unidentified. The differences in the plastic deformation features for the two groups might correlate to the particular geologic conditions under which the diamonds formed. Fluorescence and thermoluminescence experiments on natural chameleon diamonds reveal that an emission band, peaking near 556nm, may be stimulated via a number of different mechanisms. We discuss the implications of our observations for the electronic structure of the 556nm-fluorescing defect center, and the connections to the unidentified color center responsible for chameleon color changes.
DS201703-0442
2017
Butler, J.E.Zubkov, V.I., Solomnikova, A.V., Post, J.E., Gaillou, E., Butler, J.E.Characterization of electronic properties of natural type 11b diamonds.Diamond and Related Materials, Vol. 72, pp. 87-93.TechnologyDiamonds - type 11b

Abstract: Precision admittance spectroscopy measurements were carried out over wide temperature and frequency ranges for a set of natural single crystal type IIb diamond samples. Peaks of conductance spectra vs. temperature and frequency were used to compute the Arrhenius plots, and activation energies were derived from these plots. The capacitance-voltage profiling was used to estimate the majority charge carrier concentration and its distribution into depth of the samples. Apparent activation energies between 315 and 325 meV and the capture cross section of about 10? 13 cm2 were found for samples with uncompensated boron concentrations in the range of 1 to 5 × 1016 cm? 3 (0.06-0.3 ppm). The obtained boron concentrations are in good coincidence with FTIR results for the samples. Also, a reason for the difference between the observed admittance activation energy and the previously reported ionization energy for the acceptor boron in diamond (0.37 eV) is proposed.
DS201705-0813
2017
Butler, J.E.Butler, J.E., Feigelson, B.N.Laboratory-Grown Diamonds.lithographie.org, No. 19, pp. 114-127.TechnologyBook - synthetics
DS201802-0224
2018
Butler, J.E.Byrne, K.S., Butler, J.E., Wang, W., Post, J.E.Chameleon diamonds: thermal processes governing luminescence and model for the color change.Diamond & Related Materials, Vol. 81, pp. 45-53.Technologyluminescence

Abstract: To date, the eponymous color-changing behavior of chameleon diamonds lacks an explanation in terms of an identified diamond defect structure or process. Well known, however, is that this color-change is driven by the influence of both light and heat. In this paper, we present observations of how luminescence emission in chameleon diamonds responds to temperature changes and optical pumping. Fluorescence, phosphorescence, and thermoluminescence experiments on a suite of natural chameleon diamonds reveal that a specific emission band, peaking near 550 nm, may be stimulated by several different mechanisms. We have observed thermal quenching of the 550 nm emission band with an activation energy of 0.135 eV. The 550 nm band is also observed in phosphorescence and thermoluminescence. Thermoluminescence spectra suggest the presence of low lying acceptor states at 0.7 eV above the valence band. When excited with 270 nm light, we observe emission of light in two broad spectral bands peaking at 500 and 550 nm. We suggest that the 550 nm emission band results from donor—acceptor pair recombination (DAPR) from low lying acceptor states at ca. 0.7 eV above the valence band and donor states approximately 2.5 to 2.7 eV above the valence band. We do not identify the structure of these defects. We propose a speculative model of the physics of the color change from ‘yellow’ to ‘green’ which results from increased broad-band optical absorption in the near-IR to visible due to transitions from the valence band into un-ionized acceptor states available in the ‘green’ state of the chameleon diamond. We report near-IR absorption spectra confirming the increased absorption of light in the near-IR to visible in the ‘green’ when compared to the ‘yellow’ state with a threshold at ca. 0.65 eV, supporting the proposed model.
DS201804-0676
2017
Butler, J.E.Butler, J.E., Post, J.E., Wang, W.The Foxfire diamond revisited. Diavik ( using DiamondView phosphoresence)Gems & Gemology Lab Notes, Vol. 53, 4, pp. 479-481.Canada, Northwest Territoriesdiamond notable - Foxfire

Abstract: The largest gem-quality rough diamond found in Canada, reported earlier in Gems & Gemology (Summer 2016 GNI, pp. 188-189), has revealed remarkable responses to excitation with long- and mid-wave UV light. This 187.63 ct diamond (figure 1) was extracted from the Diavik mine in the Canadian Arctic in the spring of 2015. Aptly named for the aurora borealis, the “Foxfire” displays unusual fluorescence and phosphorescence behavior upon exposure to ultraviolet light. As previously reported, this type Ia diamond has a high concentration of nitrogen impurities, a weak hydrogen-related absorption at 3107 cm-1, and typical "cape" absorption lines.
DS201901-0011
2018
Butler, J.E.Butler, J.E., Byrne, K.S., Wang, W., Post, J.E.Complex charge transfer in chameleon diamonds: a model of the color-change process,Gems & Gemology, Sixth International Gemological Symposium Vol. 54, 3, 1p. Abstract p. 303.Globaldiamond color

Abstract: A group of natural diamonds known as chameleon diamonds change color from green to yellow based on their exposure to light and heat. These diamonds also emit long-lived phosphorescence after UV excitation. We have observed the optical response of these diamonds to optical and thermal excitation and developed a model to explain the observed phenomena. A principal element of the model is the proposal of an acceptor state (figure 1), which should be observable in the near-infrared (NIR) region. Subsequently, we have observed the NIR absorption to this acceptor state, supporting our model of charge-transfer processes in these diamonds.
DS201907-1551
2019
Butler, J.E.Howell, D., Collins, A.T., Loudin, L.C., Diggle, P.L., D;Haenens-Johansson, U.F.S., Smit, K.V., Katrusha, A.N., Butler, J.E., Nestola, F.Automated FTIR mapping of boron distribution in diamond. Type IlbDiamond and Related Materials, in press available 33p.GlobalDiaMap

Abstract: Type IIb diamonds are those that contain more boron than nitrogen. The presence of this uncompensated boron gives rise to absorption in the infrared part of the electromagnetic spectrum, extending into the visible region and often resulting in blue colouration. Here we report on the expansion of the DiaMap freeware (for the automated spectral deconvolution of Type I [nitrogen containing] diamonds) to work on Type IIb diamonds, returning concentrations from three boron-related absorption bands, and determining which band provides the most reliable value. The program uses the calibration coefficients of Collins (2010), which show good relative agreement between the three bands, but might require some further study to confirm their absolute accuracy to the uncompensated boron concentration. The methodology of DiaMap_IIb is applicable to all Type IIb diamonds, both natural and synthetic. Analysis of high-resolution Fourier-transform infrared (FTIR) maps of two high-pressure high-temperature (HPHT) synthetic diamonds using DiaMap_IIb, confirm the growth sector dependence of the boron incorporation. Partitioning of boron strongly favours the octahedral {111} sectors.
DS202004-0530
2020
Butler, J.E.Post, J.E., Feather, R., Butler, J.E.Kimberley diamond acquired by the Smithsonian Institution and its flourescence and phosphorescence characteristics revealed. 55.08 ctJournal of Gemmology, Vol. 37, 1, pp. 14, 15.Africa, South Africa, United Statesflourescence
DS202006-0923
2020
Butler, J.E.Howell, D., Collins, A.T., Loudin, L.C., Diggle, P.L., D'Haenens-Johansson, U.F.S., Smit, K.V., Katrusha, A.N., Butler, J.E., Nestola, F.Automated FTIR mapping of boron distribution in diamond. DiaMap_IIb ( synthetics)Diamonds & Related Materials, In press available, 30p. PdfGlobalsynthetics

Abstract: Type IIb diamonds are those that contain more boron than nitrogen. The presence of this uncompensated boron gives rise to absorption in the infrared part of the electromagnetic spectrum, extending into the visible region and often resulting in blue colouration. Here we report on the expansion of the DiaMap freeware (for the automated spectral deconvolution of Type I [nitrogen containing] diamonds) to work on Type IIb diamonds, returning concentrations from three boron-related absorption bands, and determining which band provides the most reliable value. The program uses the calibration coefficients of Collins (2010), which show good relative agreement between the three bands, but might require some further study to confirm their absolute accuracy to the uncompensated boron concentration. The methodology of DiaMap_IIb is applicable to all Type IIb diamonds, both natural and synthetic. Analysis of high-resolution Fourier-transform infrared (FTIR) maps of two high-pressure high-temperature (HPHT) synthetic diamonds using DiaMap_IIb, confirm the growth sector dependence of the boron incorporation. Partitioning of boron strongly favours the octahedral {111} sectors.
DS202006-0961
2020
Butler, J.E.Zaitsev, A.M., Kazuchits, N.M., Kazuchits, V.N., Moe, K.S., Rusetsky, M.S., Korolik, O.V., Kitajima, K., Butler, J.E., Wang, W.Nitrogen-doped CVD diamond: nitrogen concentration, color and internal stress.Diamonds & Related Materials, Vol. 105, 13p. pdfMantlenitrogen

Abstract: Single crystal CVD diamond has been grown on (100)-oriented CVD diamond seed in six layers to a total thickness of 4.3 mm, each layer being grown in gas with increasing concentration of nitrogen. The nitrogen doping efficiency, distribution of color and internal stress have been studied by SIMS, optical absorption, Raman spectroscopy and birefringence imaging. It is shown that nitrogen doping is very non-uniform. This non-uniformity is explained by the terraced growth of CVD diamond. The color of the nitrogen-doped diamond is grayish-brown with color intensity gradually increasing with nitrogen concentration. The absorption spectra are analyzed in terms of two continua representing brown and gray color components. The brown absorption continuum exponentially rises towards short wavelength. Its intensity correlates with the concentration of nitrogen C-defects. Small vacancy clusters are discussed as the defects responsible for the brown absorption continuum. The gray absorption continuum has weak and almost linear spectral dependence through the near infrared and visible spectral range. It is ascribed to carbon nanoclusters which may form in plasma and get trapped into growing diamond. It is suggested that Mie light scattering on the carbon nanoclusters substantially contributes to the gray absorption continuum and determines its weak spectral dependence. A Raman line at a wavenumber of 1550 cm?1 is described as a characteristic feature of the carbon nanoclusters. The striation pattern of brown/gray color follows the pattern of anomalous birefringence suggesting that the vacancy clusters and carbon inclusions are the main cause of internal stress in CVD diamond. A conclusion is made that high perfection of seed surface at microscale is not a required condition for growth of low-stress, low-inclusion single crystal CVD diamond. Crystallographic order at macroscale is more important requirement for the seed surface.
DS202103-0423
2021
Butler, J.E.Zaitsev, A.M., Kazuchits, N.M., Moe, K.S., Butler, J.E., Korolik, O.V., Rusetsky, M.S., Kazuchits, V.Luminescence of brown CVD diamond: 468 nm luminescence center.Diamond & Related Materials, Vol. 113, 108255, 7p. PdfGloballuminescence

Abstract: Detailed study of the luminescence of multiple brown CVD diamonds was performed. It has been found that the well-known optical center with zero-phonon line at 468 nm is a characteristic of brown color. It has been found that the defects responsible for 468 nm center are located within brown striations suggesting close relation of the 468 nm center and the vacancy clusters. Simultaneous reduction of the intensity of 468 nm center and brown color during annealing support the assumption of their close relation. Identical spectroscopic parameters of the 468 nm center and the radiation center with ZPL at 492 nm suggest that the former relates to an intrinsic defect probably containing vacancies. The distribution of intensity of the 468 nm center in some brown diamonds follows the distribution of the NV? center while being opposite to that of the NV0 center and the dislocation-related A-band. This observation suggests the negative charge state of the 468 nm center. Due to its high luminescence efficiency, the 468 nm center can be used as a highly sensitive indicator of the traces of vacancy clusters. We found that the 468 nm center is detected practically in every as-grown CVD diamond including colorless CVD diamonds of high structural perfection and high purity.
DS200912-0040
2009
Butler, J.P.Beaumont, C., Jamieson, R.A., Butler, J.P., Warren, C.J.Crustal structure: a key constraint on the mechanism of ultra high pressure rock exhumation.Earth and Planetary Science Letters, Vol. 287, 1-2, pp. 116-129.MantleUHP
DS201212-0099
2012
Butler, J.P.Butler, J.P., Jamieson, R.A., Steenkamp, H.M., Robinson, P.Discovery of coesite eclogite from the Nordyane UHP domain, Western Gneiss region, Norway: field relations, metamorphic history and tectonic significance.Journal of Metamorphic Geology, in press availableEurope, NorwayCoesite
DS1983-0442
1983
Butler, J.R.Mchone, J.G., Butler, J.R.Tectonic Magmatic Origin of Mesozoic Alkalic Magmas in Eastern North America.Geological Society of America (GSA), Vol. 15, No. 6, P. 640. (abstract.).United States, Appalachia, VirginiaTectonics, Kimberlite
DS1986-0295
1986
Butler, J.R.Goldberg, S.A., Butler, J.R., Fullager, P.D.The Bakersville dike swarm: geochronology and petrogenesis of late Proterozoic basaltic magmatism in the southern Appalachian Blue RidgeAmerican Journal of Science, Vol. 286, No. 5, May pp. 403-430AppalachiaDyke
DS1989-0197
1989
Butler, J.R.Butler, J.R.Review and classification of ultramafic bodies in the Piedmont of theCarolinasGeological Society of America (GSA) Special Paper -Ultramafic rocks of the Appalachian, No. 231, pp. 19-31GlobalLamproite -ultramafics, Review
DS1995-0247
1995
Butler, R.Butler, R.When did India hit Asia?Nature, Vol. 373, Jan. 5, pp. 20-21India, AsiaTectonics, Geodynamics
DS201512-1901
2015
Butler, R.Butler, R.Destructive sampling ethics… protect natural sites, rock outcrops… code of ethics.Nature Geoscience, Vol. 8, 11, pp. 817-818.GlobalCSR
DS1992-0099
1992
Butler, R.F.Bazard, D.R., Butler, R.F.North American Polar Wander implications of Latest Triassic and Earliest Jurassic paleomagnetic polesEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p. 94United StatesPaleomagnetics, Polar Wander Path
DS1992-0236
1992
Butler, R.F.Chase, C.G., Gregory, K.M., Butler, R.F.Geologic constraints on amounts of Colorado Plateau rotationEos Transactions, Vol. 73, No. 14, April 7, supplement abstracts p. 95Colorado PlateauPaleomagnetics, Tectonics
DS1995-0248
1995
Butler, R.F.Butler, R.F., Richards, D.R., Semepere, T., Marshall, L.G.Paleomagnetic determinations of vertical axis tectonic rotation from Late Cretaceous and Paleoene strataGeology, Vol. 23, No. 9, Sept. pp. 799-802BoliviaStratigraphy, Paleomagnetism
DS1997-1022
1997
Butler, R.F.Sempere, T., Butler, R.F., et al.Stratigraphy and chronology of Upper Cretaceous lower Paleogene strata Bolivia and northwest ArgentinaGeological Society of America (GSA) Bulletin, Vol. 109, No. 6, June pp. 709-727Bolivia, ArgentinaStratigraphy, Geochronology
DS1991-0202
1991
Butler, R.T.Butler, R.T.Paleomagnetism magnetic domains to geologic terranesBlackwell Scientific, 352pGlobalPaleomagnetism, Book -ad
DS200812-0170
2008
Butler, R.W.H.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
DS1988-0097
1988
Butler, S.H.Butler, S.H.Petrography and mineral chemistry of sovite dykes Of the Cargill carbonatite complex, Kapuskasing, OntarioBsc. Thesis, Queen's University, 47p. QE 462 C36B8 Ontario Geological Survey (OGS)OntarioCarbonatite, Cargill
DS2002-0233
2002
Butler, S.L.Butler, S.L., Peltier, W.R.Thermal evolution of Earth: models with time dependent layering of mantle convection which satisfy the Urey ratio constraint.Journal of Geophysical Research, June 11, 10.1029/2000JB00018MantleGeophysics - geothermometry
DS2002-0234
2002
Butler, S.L.Butler, S.L., Peltier, W.R.Thermal evolution of Earth: models with time depenedent layering of mantle convection which satisfy the Urey ratio constraint.Journal of Geophysical Research, Vol. 107, No. 6, ESE 3 DOI 10.1029/2001JB000018MantleGeothermometry
DS200412-0252
2004
Butler, S.L.Butler, S.L., Jarvis, G.T.Stresses induced in continental lithospheres by axisymmetric spherical convection.Geophysical Journal International, Vol. 157, 3, pp. 1359-1376.MantleGeophysics - seismics, tectonics
DS200512-0128
2005
Butler, S.L.Butler, S.L., Peltier, W.R., Costin, S.O.Numerical models of the Earth's thermal history: effects of inner-core solidification and core potassium.Physics of the Earth and Planetary Interiors, Vol. 152, 1-2. Sept. 15, pp. 22-42.MantlePotassium, geothermometry, core history
DS200612-0282
2006
Butler, S.L.Costin, S.O., Butler, S.L.Modelling the effects of internal heating in the core and lowermost mantle on the Earth's magnetic history.Physics of the Earth and Planetary Interiors, Vol. 157, 1-2, pp. 55-71.MantleGeothermometry, geodynamics
DS200812-0246
2008
Butler, S.L.Costin, S.O., Butler, S.L.Enriched geochemical reservoirs in D' ? constraints from the Earth's core thermal and magnetic evolution.Goldschmidt Conference 2008, Abstract p.A182.MantleGeochemistry - CMB
DS200912-0092
2009
Butler, S.L.Butler, S.L.The effects of phase boundary induced layering on the Earth's thermal history.Geophysical Journal International, Vol. 179, 3, pp. 1330-1340.MantleGeothermometry
DS1997-0151
1997
Butt, C.Butt, C.Saprolite geochemistryShort Course held Jan. 26-27, AustraliaLaterites - saprolite, Gold, geochemistry
DS1997-0152
1997
Butt, C.Butt, C.Geochemistry of goldShort Course held Jan. 26-27, AustraliaLaterites, Gold, geochemistry
DS1997-0153
1997
Butt, C.Butt, C.Profile development - landform development in AustraliaShort Course held Jan. 26-27, AustraliaLaterites, LandforM.
DS1992-0198
1992
Butt, C.R.M.Butt, C.R.M., Zeegers, H.Regolith exploration geochemistry in tropical and subtropical terrainsElsevier, 600pAustralia, Africa, Algeria, Burkina Faso, Sudan, MaliGeochemistry -laterites, Book -table of contents
DS1995-1500
1995
Butt, C.R.M.Pirajno, F., Butt, C.R.M., Winter, E.Gold enrichment in weathered carbonatite pyroclastics of the Kruidfontein volcanic complex, South AfricaSouth African Journal of Geology, Vol. 98, No. 3, Sept. pp. 319-325South AfricaGold, Carbonatite
DS1989-0329
1989
Butt, N.A.Darwish, M.A., Butt, N.A.Forecasting in the mineral industryInternational Mining, Vol. 6, No. 12, December pp. 12-17GlobalEconomics, Mineral trends and demands
DS1993-0193
1993
Butt, P.Butt, P., Eagleson, R.MABO: what the High Court saidFederation Press, AustraliaBook -review, Legal -native
DS201312-0116
2013
Butterworth, N.P.Butterworth, N.P., Talsman, A.S., Muller, R.D., Seton, M., Bunge, H-P., Schuberth, B.S.A., Shephard, G.E., Heine, C.Geological, tomographic, kinematic and geodynamic constraints on the dynamics of sinking slabs.Earth Science Reviews, Vol. 126, pp. 235-249.MantleSubduction
DS201412-0087
2014
Butterworth, N.P.Butterworth, N.P., Talsma, A.S., Muller, R.D., Seton, M., Bunge, H-P., Schuberth, B.S.A., Shephard, G.E., Heine, C.Geological, tomographic, kinematic and geodynamic constraints on the dynamics of sinking slabs.Journal of Geodynamics, Vol. 73, pp. 1-13.MantleSubduction
DS201608-1395
2016
Butterworth, N.P.Brune, S., Williams, S.E., Butterworth, N.P., Muller, R.D.Abrupt plate accelerations shape rifted continental margins.Nature Geoscience, July 18, online 16p.MantleRifting

Abstract: Rifted margins are formed by persistent stretching of continental lithosphere until breakup is achieved. It is well known that strain-rate-dependent processes control rift evolution1, 2, yet quantified extension histories of Earth’s major passive margins have become available only recently. Here we investigate rift kinematics globally by applying a new geotectonic analysis technique to revised global plate reconstructions. We find that rifted margins feature an initial, slow rift phase (less than ten millimetres per year, full rate) and that an abrupt increase of plate divergence introduces a fast rift phase. Plate acceleration takes place before continental rupture and considerable margin area is created during each phase. We reproduce the rapid transition from slow to fast extension using analytical and numerical modelling with constant force boundary conditions. The extension models suggest that the two-phase velocity behaviour is caused by a rift-intrinsic strength-velocity feedback, which can be robustly inferred for diverse lithosphere configurations and rheologies. Our results explain differences between proximal and distal margin areas3 and demonstrate that abrupt plate acceleration during continental rifting is controlled by the nonlinear decay of the resistive rift strength force. This mechanism provides an explanation for several previously unexplained rapid absolute plate motion changes, offering new insights into the balance of plate driving forces through time.
DS1991-0203
1991
Butterworth, P.Butterworth, P., Otis, A., Stein, J.The gemstone object database management systemCommunications of the ACM., Vol. 34, No. 10, October LFA.8A842 pp. 64-77GlobalDatabase, Gemstones ?
DS1920-0433
1929
Buttgenbach, E.Buttgenbach, E.Diamants, Lazulite et Atacamite du Congo BelgeSoc. Geol. Belge Annual, Vol. 52, No. 3, PP. C65-C68.Democratic Republic of Congo, Central AfricaDiamond
DS1900-0242
1904
Buttgenbach, H.Buttgenbach, H.Quelques Observatioons sur Les Champs Diamantiferes de Kimberley.Annual SOC. GEOL. BELG., Vol. 31, PP. M3-M14.Africa, South AfricaAlluvial Diamond Placers, Geology
DS1900-0243
1904
Buttgenbach, H.Buttgenbach, H.Quelque Mots sur les Cheminees Diamantiferes de KimberleyAnnual SOC. GEOL. BELG., Vol. 32, PP. B163-B165.Africa, South AfricaKimberlite Mines And Deposits, Geology
DS1900-0742
1909
Buttgenbach, H.Buttgenbach, H.Sur Une Roche Diamantifere Trouvee Au Conge BelgeSoc. Geol. Belg. Annual, VO. 36, PP. B77-B79.Africa, Democratic Republic of CongoHistory
DS1910-0034
1910
Buttgenbach, H.Buttgenbach, H.Description des Mineraux du Congo BelgeAnnual DU MUSEE DO CONGO BELGE., PP. 6-10.Democratic Republic of Congo, Central AfricaMineral Catalogue
DS1920-0224
1925
Buttgenbach, H.Buttgenbach, H.Mineralogie du Congo BelgeBruxelles: M. Hayez, 183P.Democratic Republic of Congo, Central AfricaMineral Catalogue, Kimberley
DS1998-0194
1998
Buttles, J.Buttles, J., Olson, P.A laboratory model of subduction zone anisotropyEarth and Planetary Science Letters, Vol. 164, No.1-2, Dec.15, pp. 245-62.MantleSubduction
DS1860-0654
1890
Buttner, C.G.Buttner, C.G.Erinnerungen an Meine Reise in Suedwest Afrika von Berseba Bis Okahandja in Jahre 1885.Berlin: Verh. Ges. Erdk., Vol. 17, PP. 371-398.Africa, NamibiaTravelogue
DS1998-0195
1998
Buttner, R.Buttner, R., et al.Thermal conductivity of a volcanic rock material (olivine-melilitite) in temperature range. - 288-1470KJournal of Vol. Geotherm. Res., Vol. 80, No. 3-4, Feb. pp. 293-302.GlobalMelilitite, Geothermometry
DS1998-0818
1998
Buttner, R.Kurszlaukis, S., Buttner, R., Zimanowski, B., LorenzOn the first experimental phreatomagmatic explosion of a kimberlite meltJournal of Vol. Geotherm. Res., Vol. 80, pp. 323-326.Namibiavolcanism - explosive, deposit - Gibeon field
DS1998-0819
1998
Buttner, R.Kurszlaukis, S., Lorenz, V., Zimanowski, V., Buttner, R.Experiments on explosive interaction of molten kimberlite with injectedwater.7th International Kimberlite Conference Abstract, pp. 483-5.NamibiaKimberlite magma, phreatomagmatic, Deposit - Hanaus 2, Gibeon Province
DS1999-0421
1999
Buttner, R.Lorenz, V., Zimanowski, B., Buttner, R., Kurszlaukis, S.Formation of kimberlite diatremes by explosive interaction of kimberlite magma with groundwater:7th International Kimberlite Conference Nixon, Vol. 2, pp. 522-28.Namibia, TanzaniaPetrology - experimental, Fluidization, phreatomagmatisM.
DS200412-2234
2004
Buttner, R.Zimanowski, B., Buttner, R., Koopmann, A.Experiments on magma mixing.Geophysical Research Letters, Vol. 31, 9, May 16, 10.1029/2004 GLO19687MantleMagmatism - not specific to diamonds
DS200612-0202
2006
Buttner, R.Buttner, R., Dellino, P., Raue, H., Sonder, I., Zimanowski, B.Stress induced brittle fragmentation of magmatic melts: theory and experiments.Journal of Geophysical Research, Vol. 111, No. B8, B08204MantleMagmatism
DS200812-0066
2008
Buttner, R.Austin-Erickson, A., Buttner, R., Delino, P., Ort, M.H., Zimanowski, B.Phreatomagmatic explosions of rhyolitic magma: experimental and field evidence.Journal of Geophysical Research, Vol. 113, B11201.TechnologyMagmatism
DS201902-0277
2019
Buttner, S.H.Howarth, G.H., Buttner, S.H.New constraints on archetypal South African kimberlite petrogenesis from quenched glass-rich melt inclusions in olive megacrysts.Gondwana Research, Vol. 68, pp. 116-126.Africa, South Africadeposit - Monastery
DS201904-0746
2019
Buttner, S.H.Howarth, G.H., Buttner, S.H.New constraints on archtypal South African kimberite petrogenesis from quenched glass-rich melt inclusions in olivine megacrysts.Gondwana Research, Vol. 68, 1, pp. 116-126.Africa, South Africapetrology

Abstract: The evaluation of primary kimberlite compositions is hindered by significant melt modifications during ascent through the lithosphere by entrainment of xenolithic material, volatile degassing, and near surface alteration. Consequently, hypabyssal kimberlite emplaced in the upper crust may not provide a true reflection of the primary kimberlite magma. This contribution places new constraints on kimberlite melt composition by providing an assessment of quenched glass-rich polymineralic melt inclusions hosted in olivine megacrysts from the Monastery kimberlite, South Africa. Melt inclusions predominantly contain variable proportions of euhedral or skeletal grains of calcite, phlogopite, spinel, perovskite, serpentine, and fresh to devitrified glass. Estimates of the bulk compositions of melt inclusions, and the compositions of crystalline phases present therein, are compatible to those of hypabyssal kimberlites worldwide and show a volatile-rich (CO2?+?H2O ~10-17?wt%) carbonated silicate (SiO2 ~27-41?wt%) composition. The glass component has a Si-Mg-Fe-rich and largely CaO-, K2O- and TiO2-free major element composition and is REE-depleted. It also contains approximately 10?wt% H2O but is CO2?free. The glass represents a residual melt that existed after crystallization of the observed mineral assemblage. From some, but not all melt inclusions, apophyses radiate outwards. These fractures typically contain partially devitrified glass that is compositionally identical to the fresh residual glass within the melt inclusions, indicating fracture formation during decompression of the hosting megacryst and at a stage after the melt had evolved. These features are consistent with a trapping of the melt inclusions at high pressure, prior to kimberlite ascent to the surface, in the SCLM at a depth corresponding to 4.5-6?GPa. Textures and compositions of phases within the melt inclusions represent stages of the kimberlite melt and magma evolution. They provide evidence in support of high-pressure experimental studies suggesting a carbonated silicate primary melt rather than a carbonatite. Furthermore, the composition of fresh glass in the melt inclusions, which is compositionally similar to serpentine, suggests that much groundmass serpentine in hypabyssal kimberlites may have formed from similar silicate melt or devitrified glass.
DS1970-0862
1974
Button, A.Anhaeusser, C.R., Button, A.A Review of Southern African Stratiform Ore Deposits- Their position in Time and Space.Economic Geology Research Unit., INF. Circular No. 85, 45P.South Africa, BotswanaDiamonds, Review, Regional Geology
DS2003-0124
2003
Butvina, 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
DS200812-0994
2008
Butvina, V.Safonov, O., Perchuk, L., Litvin, Y., Chertkova, N., Butvina, V.Experimental modeling of chloride bearing diamond related liquids: a review.Goldschmidt Conference 2008, Abstract p.A817.Africa, Botswana, South America, Brazil, Russia, CanadaDiamond inclusions
DS202003-0360
2019
Butvina, V.Safonov, O., Butvina, V., Limanov, E.Phlogopite forming reactions as indicators of metasomatism in the lithospheric mantle.Minerals ( MDPI), Vol. 9, 18p. PdfMantlemetasomatism

Abstract: Phlogopite is widely accepted as a major mineral indicator of the modal metasomatism in the upper mantle within a very wide P-T range. The paper reviews data on various phlogopite-forming reactions in upper-mantle peridotites. The review includes both descriptions of naturally occurring reactions and results of experiments that model some of these reactions. Relations of phlogopite with other potassic phases, such as K-richterite, sanidine and K-titanates, are discussed. These data are taken as a basis for thermodynamic modeling of the phlogopite-forming reactions for specific mantle rocks in terms of log(aH2O) ? log(aK2O) diagrams (pseudosections) using the Gibbs free energy minimization. These diagrams allow estimation of potassium-water activity relations during metasomatic transformations of mantle rocks, prediction sequences of mineral assemblages with respect to these parameters and comparison of metasomatic processes in the rocks of different composition. This approach is illustrated by examples from peridotite xenoliths from kimberlites.
DS2002-0953
2002
Butvina, V.G.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
Butvina, V.G.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
DS2002-0955
2002
Butvina, V.G.Litvin, Y.A., Butvina, V.G., Spivak, A.V.Formation of natural diamonds in carbonate silicate and sulphide melts: the evidence from high pressure experiments.18th. International Mineralogical Association Sept. 1-6, Edinburgh, abstract p.75.Russia, ChinaUHP - mineralogy, Kokchetav, Dabie Shan
DS200412-1152
2004
Butvina, V.G.Litvin, Y.A., Butvina, V.G.Diamond forming media in the system eclogite carbonatite sufide carbon.Petrology, Vol.12, 4, pp. 377-388.TechnologyDiamond genesis
DS200912-0093
2009
Butvina, V.G.Butvina, V.G., Nielsen, T.F.D., Safonov, O.G., Litvin, Yu.A.Experimental study on melting phase relations and diamond formation in the carbonate rich kimberlite from Majugaa southern west Greenland.alkaline09.narod.ru ENGLISH, May 10, 2p. abstractEurope, GreenlandManiitsoq
DS200912-0443
2009
Butvina, V.G.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
DS201909-2027
2019
Butvina, V.G.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.
DS201912-2826
2019
Butvina, V.G.Sofonov, O.G., Butvina, V.G., Limanov, E.V., Kosova, S.A.Mineral indicators of reactions involving fluid salt components in the deep lithosphere. (eclogites and peridotites)Petrology, Vol. 27, pp. 489-515.MantleUHP, redox

Abstract: The salt components of aqueous and aqueous-carbonic fluids are very important agents of metasomatism and partial melting of crustal and mantle rocks. The paper presents examples and synthesized data on mineral associations in granulite- and amphibolite-facies rocks of various composition in the middle and lower crust and in upper-mantle eclogites and peridotites that provide evidence of reactions involving salt components of fluids. These data are analyzed together with results of model experiments that reproduce some of these associations and make it possible to more accurately determine their crystallization parameters.
DS202011-2050
2020
Butvina, V.G.Limanov, E.V., Butvina, V.G., Safonov, O.G., Van, K.V., Aranovich, L. Ya.Phlogopite formation in the orthopyroxene-garnet system in the presence of H2O-KCL fluid to the processes of mantle metasomatism.Doklady Earth Sciences, Vol. 494, 1, pp. 713-717.Russiametasomatism

Abstract: The results of experimental studies are presented for reactions in the orthopyroxene-garnet-phlogopite system in the presence of H2O-KCl fluid at 3-5 GPa and 900-1000°C, which model the processes of phlogopite formation in garnet peridotites and pyroxenites during alkaline metasomatism of the upper mantle. The experiments demonstrated regular variations in the composition of garnet, pyroxenes, and phlogopite depending on the KCl content of the fluid. With increasing KCl content of the fluid, enstatite and garnet become unstable, the Al2O3 content of enstatite decreases, and the amount of grossular and knorringite components in garnet are maximum at a KCl content of ~10 mol %. Our results illustrate well the regular variations in the compositions of the coexisting minerals and their zoning in phlogopite-bearing peridotites of the lithospheric mantle.
DS1970-0926
1974
Butzer, K.W.Helgren, D.M., Butzer, K.W.Alluvial Terraces of the Lower Vaal River, South Africa: a Reappraisal and Reinvestigation: a Reply.Journal of Geology, Vol. 82, PP. 665-667.South AfricaGeomorphology
DS1989-0198
1989
Buxton, B.E.Buxton, B.E.An application of the construction of confidence intervals for global recoverable reserve estimatesGeostatistics, Proceedings Volume edited by M. Armstrong, Vol. 2, pp. 875-887. Database # 17985GlobalGeostatistics, Economics -reserve estimates
DS2001-0153
2001
Buxton, N.Buxton, N.Diamond resource estimation - estimating the average dollar per carat value for mine feasibility exercises.Prospectors and Developers Association of Canada (PDAC) 2001, 1p. abstractNorthwest TerritoriesNews item
DS1989-0855
1989
Buyagu, S.Lavreau, J., Buyagu, S., Liegeois, J.P., Navez, J.Geochemical evidence for a non-alkalic origin for the carbonatitic bodies of Kibuye, RwandaJournal of African Earth Sciences, Vol. 9, No. 2, pp. 335-340GlobalCarbonatite, Geochemistry
DS1996-1484
1996
Buyakaite, M.I.Vinogradov, V.I., Pichugin, L.P., Buyakaite, M.I.Isotopic features and dating of epigenetic alterations of upper Precambrian deposits of the Ural UpliftLithology and Mineral resources, Vol. 31, No. 1, Jan. pp. 60-69Russia, UralsAlteration, Geochronology
DS1985-0033
1985
Buyakayte, M.I.Bagdasarov, Y.A., Buyakayte, M.I.Peculiarities of Carbonatite Formation in Carbonate Sedimentary Rocks According to Isotopic Geochemical Data.Geochemistry International (Geokhimiya)., No. 4, PP. 559-568.RussiaBlank
DS1986-0038
1986
Buyakayte, M.I.Bagdasarov, Yu.A., Buyakayte, M.I.Isotopic dat a on carbonatite formation in carbonate sedimentsGeochemistry International, Vol. 22, No. 7, pp. 30-38RussiaCarbonatite, Geochronology
DS1999-0727
1999
BuyankinaTarabukin, V., Kanygin, Smironov, Pavlushin, BuyankinaFindings of Paleozoic conodonts in xenoliths from kimberlite pipes on the Siberian PlatformRussian Geology and Geophysics, Vol. 40, No. 6, pp. 818-26.Russia, SiberiaXenoliths
DS1983-0164
1983
Buykov, V.I.Buykov, V.I., Vishnevskiy, A.A., Tsymbal, S.N., Chebotarev, V.A.Optico-spectroscopic and Colorimetric Parameters of Pyrope And Pyrope-almandine of Sedimentary Deposits of Central Bug.Mineral. Zhurnal, Vol. 5, No. 3, PP. 42-49.RussiaPetrology, Kimberlite, Probe Data
DS202008-1373
2020
Buyse, F.Buyse, F., Dewaele, S., Decree, S., Mees, F.Mineralogical and geochemical study of the rare earth element mineralization at Gakara ( Burundi).Ore Geology Reviews, Vol. 124, 103659 10p. PdfAfrica, BurundiREE

Abstract: The rare earth element (REE) mineralization of Gakara (Burundi) has first been discovered in 1936 and has periodically been the subject of geological studies, at times when the exploitation of bastnäsite-(Ce) and monazite-(Ce) was economically interesting. This study focuses on the establishment of a mineral paragenesis for Gakara, with special attention to the REE-bearing phases, to understand the formation history of the deposit. The paragenesis can be subdivided into 3 stages: primary ore deposition, brecciation stage and supergene alteration. Evidence for fenitization processes (i.e. pinkish-red cathodoluminescence of K-feldpar, brecciation stage) and the strong enrichment of light REEs in bastnäsite and monazite substantiate the hypothesis of a structurally controlled hydrothermal mineralization with a strong carbonatitic affinity. This likely confirms the association of the Gakara REE deposit with the Neoproterozoic alignment of alkaline complexes and carbonatites along the present-day Western Rift. It suggests a direct link with a - currently unidentified - carbonatitic body at depth, possibly derived from a predominantly metasomatized lithospheric mantle.
DS201112-0945
2011
Buzlukova, L.Shatsky, V.S., Malkovets, V.G., Buzlukova, L., Griffin, W.L., Belousova, E.A., O'Reilly, S.Y.Deep crust of the Siberian craton evidence from xenolith.Goldschmidt Conference 2011, abstract p.1850.RussiaUdachnaya, Leningradskaya, Yubileynaya
DS200512-0129
2004
Buzlukova, L.V.Buzlukova, L.V., Shatsky, V.S., Sobolev, N.V.Specific structure of the lowermost Earth's crust at the Zagadochnaya kimberlite pipe.Russian Geology and Geophysics, Vol. 45, 8, pp. 942-959.Russia, YakutiaStructure - Zagadochnaya
DS200612-1270
2005
Buzlukova, L.V.Shatsky, V.S., Buzlukova, L.V., Jagoutz, F., Kozmenko, O.A., Mityukhin, S.I.Structure and evolution of the lower crust of the Daldyn Alakit district in the Yakutian diamond province ( from dat a on xenoliths).Russian Geology and Geophysics, Vol. 46, 12, pp. 1252-1270.Russia, YakutiaPetrology - peridotites
DS200912-0470
2009
Buzlukova, L.V.Malkovets, V.G., Belousova, E.A., Griffin, W.L., Buzlukova, L.V., Shatsky, V.S., O'Reilly, S.Y., Pokhilenko, N.P.U/Pb dating of zircons from the lower crustal xenoliths from Siberian kimberlites.Goldschmidt Conference 2009, p. A823 Abstract.Russia, SiberiaDeposit - Udachnaya
DS201910-2298
2019
Buzmakov, A.V.Shiryaev, A.A., Kaminisky, F.V., Ludwig, W., Zolotov, D.A., Buzmakov, A.V., Titlov, S.V.Texture and genesis of polycrystalline varieties of diamond based on phase-contrast and diffraction contrast tomography.Geochemistry International, Vol. 57, 9, pp. 1015-1023.South America, Brazil, Africa, Central African Republic, Russiacarbonado

Abstract: Structural peculiarities of several types of cryptocrystalline diamond varieties: carbonado, impact-related yakutite and cryptocrystalline diamond aggregates from kimberlite were studied using Infrared spectroscopy, X-ray diffraction contrast (DCT—Diffraction Contrast Tomography) and phase contrast tomography (PCT). It is shown that the porosity of the carbonado and kimberlitic cryptocrystalline aggregates is similar being in range of 5-10 vol %, possibly indicating similar formation mechanism(s), whereas that of yakutite is essentially zero. Crystallographic texture is observed for some carbonado samples. It is suggested that at least partially the texture is explained by deformation-related bands. Infrared spectroscopy reveals presence of hydrous and, probably, of hydrocarbon species in carbonado.
DS2000-0475
2000
Byakov, A.F.Kazmin, V.G., Byakov, A.F.Magmatism and crustal accretion in continental riftsJournal of African Earth Sciences, Vol. 30, No.3, pp. 555-68.BotswanaMagmatism, Tectonics - rifting
DS1990-0259
1990
Byakov, V.M.Byakov, V.M., Pimonov, G.G., Stepanov, O.P.Mechanism for the formation of diamonds in meteoritesSov. Astr. L., Vol. 16, No. 6, Nov-Dec. pp. 452-453. # FR106RussiaDiamonds, Meteorites
DS202101-0017
2020
Bybee, G.M.Hughes, H.S.R., Compton-Jones, C., MvDonald, I., Kiseeva, E.S., Kamenetsky, V.S., Rollinson, G., Coggon, J.A., Kinnaird, J.A., Bybee, G.M.Base metal sulphide geochemistry of southern African mantle eclogites ( Roberts Victor): implications for cratonic mafic magmatism and metallogenesis.Lithos, doi.org/10.1016/ j.lithos.2020.105918 67p. PdfAfrica, South Africadeposit - Roberts Victor

Abstract: Platinum-group elements (PGE) display a chalcophile behaviour and are largely hosted by base metal sulphide (BMS) minerals in the mantle. During partial melting of the mantle, BMS release their metal budget into the magma generated. The fertility of magma sources is a key component of the mineralisation potential of large igneous provinces (LIP) and the origin of orthomagmatic sulphide deposits hosted in cratonic mafic magmatic systems. Fertility of mantle-derived magma is therefore predicated on our understanding of the abundance of metals, such as the PGE, in the asthenospheric and lithospheric mantle. Estimations of the abundance of chalcophile elements in the upper mantle are based on observations from mantle xenoliths and BMS inclusions in diamonds. Whilst previous assessments exist for the BMS composition and chalcophile element budget of peridotitic mantle, relatively few analyses have been published for eclogitic mantle. Here, we present sulphide petrography and an extensive in situ dataset of BMS trace element compositions from Roberts Victor eclogite xenoliths (Kaapvaal Craton, South Africa). The BMS are dominated by pyrite-chalcopyrite-pentlandite (± pyrrhotite) assemblages with S/Se ratios ranging 1200 to 36,840 (with 87% of analyses having S/Se this editing is incorrect. This should read "(with 87% of analyses having S/Se < 10,000)" Please note the 100 ppm) and are characteristically enriched in Os, Ir, Ru and Rh. Nano- and micron-scale Pd-Pt antimonide, telluride and arsenide platinum-group minerals (PGM) are observed spatially associated with BMS. We suggest that the predominance of pyrite in the xenoliths reflects the process of eclogitisation and that the trace element composition of the eclogite BMS was inherited from oceanic crustal protoliths of the eclogites, introduced into the SCLM via ancient subduction during formation of the Colesberg Magnetic Lineament c. 2.9 Ga and the cratonisation of the Kaapvaal Craton. Crucially, we demonstrate that the PGE budget of eclogitic SCLM may be substantially higher than previously reported, akin to peridotitic compositions, with significant implications for the PGE fertility of cratonic mafic magmatism and metallogenesis. We quantitatively assess these implications by modelling the chalcophile geochemistry of an eclogitic melt component in parental magmas of the mafic Rustenburg Layered Suite of the Bushveld Complex.
DS202107-1110
2021
Bybee, G.M.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
Bybee, G.M.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.
DS201709-1962
2017
Bychkov, 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.
DS201802-0252
2017
Bychkov, A.Y.Marchenko, E.I., Eremin, N.N., Bychkov, A.Y., Grechanovskii, A.E.Ca and Mg perovskite phases in the Earth's mantle as a probable reservoir of Al: computer simulated evidence.Moscow University Geology Bulletin, Vol. 72, 5, pp. 299-304.Mantleperovskite

Abstract: Semi-empirical and quantum chemical studies of Al atom energy in CaSiO3 and MgSiO3 with the perovskite-type structure at pressures and temperatures of the Earth’s mantle are reported. The phase diagram for CaSiO3 is reproduced and refined. Probable mechanisms of Al incorporation in the structures studied are considered. According to the results of the calculations, Al is preferably incorporated into MgSiO3, rather than into CaSiO3. Evaluation of the isomorphic capacity of perovskite phases in relation to Al shows that the Al content in MgSiO3 may reach 2.4 mol % at 120 GPa and 2400 K. CaSiO3 cannot be a source of Al atoms in the Earth’s mantle.
DS201901-0050
2018
Bychkov, A.Y.Ogorodova, L.P., Gritsenko, Y.D., Vigasina, M.F., Bychkov, A.Y., Ksenofontov, D.A., Melchakova, L.V.Thermodynamic properties of natural melilites.American Mineralogist, Vol. 103, pp. 1945-1952.Mantlemineralogy

Abstract: In the present study, four samples of natural melilites were characterized using electron microprobe analysis, powder X-ray diffraction, FTIR, and Raman spectroscopy, and their thermodynamic properties were measured with a high-temperature heat-flux Tian-Calvet microcalorimeter. The enthalpies of formation from the elements were determined to be: -3796.3 ± 4.1 kJ/mol for Ca1.8Na0.2(Mg0.7Al0.2Fe2+0.1?)Si2O7, -3753.6 ± 5.2 kJ/mol for Ca1.6Na0.4(Mg0.5Al0.4Fe2+0.1?)Si2O7, -3736.4 ± 3.7 kJ/mol for Ca1.6Na0.4(Mg0.4Al0.4Fe2+0.2?)Si2O7, and -3929.2 ± 3.8 kJ/mol for Ca2(Mg0.4Al0.6)[Si1.4Al0.6O7]. Using the obtained formation enthalpies and estimated entropies, the standard Gibbs free energies of formation of these melilites were calculated. Finally, the enthalpies of the formation of the end-members of the isomorphic åkermanite-gehlenite and åkermanite-alumoåkermanite series were derived. The obtained thermodynamic properties of melilites of different compositions can be used for quantitative modeling of formation conditions of these minerals in related geological and industrial processes.
DS202012-2206
2020
Bychkov, 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.
DS200612-0203
2006
Bychkova, Ya.V.Bychkova, Ya.V., Kulikov, V.S., Kulikova, V.V., Vasiliev, M.V.Early Paleoproterozoic vulcano-plutonic komatiitic association of southeast Fennoscandia as mantle plume 'windybelt' realization.Vladykin: VI International Workshop, held Mirny, Deep seated magmatism, its sources and plumes, pp. 174-187.Europe, Finland, Sweden, Baltic Shield, FennoscandiaHotspots
DS201412-0902
2014
Bychkova, Ya.V.Sushchevskaya, N.M., Migdisova, N.A., Antonov, A.V., Krymsky, R.Sh., Belyatsky, B.V., Kuzmin, D.V., Bychkova, Ya.V.Geochemical features of the Quaternary lamproitic lavas of Gaussberg volcano, East Antarctica: result of the impact of the Kerguelen plume.Geochemistry International, Vol. 52, 12, pp. 1030-1048.AntarcticaLamproitic lavas
DS2001-0007
2001
BydaevAgashev, A.M., Watanabe, Bydaev, Pokhilenko, FominGeochemistry of kimberlites from the Nakyn field, Siberia: evidence for unique source composition.Geology, Vol. 29, No. 3, Mar. pp. 267-70.Russia, SiberiaGeochronology, geochemistry
DS200412-1167
2004
Bye, M.Lockell, N., Bye, M.Remote sensing applied to diamond exploration. Images from aircraft and satellites to construct maps aiding diamond exploration.Rough Diamond Review, No. 5, June, pp.15-21.AustraliaRemote sensing
DS201712-2677
2017
Byerley, B.L.Byerley, B.L., Kareem, K., Bao, H., Byerley, G.R.Early Earth mantle heterogeneity revealed by light oxygen isotopes of Archean komatiites.Nature Geoscience, Vol. 10, 11, pp. 871-875.Mantlegeochronology

Abstract: Geodynamic processes on early Earth, especially the interaction between the crust and deep mantle, are poorly constrained and subject to much debate. The rarity of fresh igneous materials more than 3 billion years old accounts for much of this uncertainty. Here we examine 3.27-billion-year-old komatiite lavas from Weltevreden Formation in the Barberton greenstone belt, which is part of the Kaapvaal Craton in Southern Africa. We show that primary magmatic compositions of olivine are well preserved in these lavas based on major and trace element systematics. These komatiitic lavas represent products of deep mantle plumes. Oxygen isotope compositions (?18O) of the fresh olivine measured by laser fluorination are consistently lighter (about 2‰) than those obtained from modern mantle-derived volcanic rocks. These results suggest a mantle source for the Weltevreden komatiites that is unlike the modern mantle and one that reflects mantle heterogeneity left over from a Hadean magma ocean. The anomalously light ?18O may have resulted from fractionation of deep magma ocean phases, as has been proposed to explain lithophile and siderophile isotope compositions of Archaean komatiites.
DS201712-2677
2017
Byerley, G.R.Byerley, B.L., Kareem, K., Bao, H., Byerley, G.R.Early Earth mantle heterogeneity revealed by light oxygen isotopes of Archean komatiites.Nature Geoscience, Vol. 10, 11, pp. 871-875.Mantlegeochronology

Abstract: Geodynamic processes on early Earth, especially the interaction between the crust and deep mantle, are poorly constrained and subject to much debate. The rarity of fresh igneous materials more than 3 billion years old accounts for much of this uncertainty. Here we examine 3.27-billion-year-old komatiite lavas from Weltevreden Formation in the Barberton greenstone belt, which is part of the Kaapvaal Craton in Southern Africa. We show that primary magmatic compositions of olivine are well preserved in these lavas based on major and trace element systematics. These komatiitic lavas represent products of deep mantle plumes. Oxygen isotope compositions (?18O) of the fresh olivine measured by laser fluorination are consistently lighter (about 2‰) than those obtained from modern mantle-derived volcanic rocks. These results suggest a mantle source for the Weltevreden komatiites that is unlike the modern mantle and one that reflects mantle heterogeneity left over from a Hadean magma ocean. The anomalously light ?18O may have resulted from fractionation of deep magma ocean phases, as has been proposed to explain lithophile and siderophile isotope compositions of Archaean komatiites.
DS201811-2558
2018
Byerly, B.Byerly, B.Extraordinary crystals hold secrets of Earth's infancy. ( Barberton area)Nature , Oct 1, 1p.Africa, South Africazircons

Abstract: Geologists have a new window onto the early Earth: zircon crystals from South Africa that could be as much as 4.1 billion years old. Ancient crystals of zircon - a durable mineral found in rock that has been squeezed and heated - from Western Australia have revealed some of the planet’s early secrets, such as clues to the chemistry of its primordial crust. But researchers have had little in the way of other records for this period of Earth’s infancy. Now, Benjamin Byerly at Louisiana State University in Baton Rouge and his colleagues report their discovery of a second rich trove of zircons. The crystals lie east of Pretoria, in a rock formation known as the Barberton greenstone belt. The African zircons are important because they have been subject to less heating and squeezing than the Australian samples. As a result, the African crystals may have richer stories to tell about the chemistry of Earth’s early years.
DS201907-1576
2019
Byerly, G.Sobolev, A.V., Asafov, E., Arndt, N., Portnyagin, M., Guenko, A.A., Batanova, G., Garbe-Schonberg, D., Wilson, A.H., Byerly, G., Batanova, V.Deep hydrous mantle reservoir provides evidence for crustal recycling before 3.3 billion years ago.Nature, 32p. Pdf availableMantlewater

Abstract: H2O strongly influences physical properties of the mantle and its ability to melt or convect and can trace recycling of surface reservoirs down to the deep mantle1,2. This makes knowledge of water content in the Earth's interior and its evolution through time crucial to understanding global geodynamics. Komatiites (MgO-rich ultramafic magmas) result from high-degree mantle melting at high pressures3 and thus are excellent probes of H2O contents in the deep mantle. A significant excess of H2O over elements of similar geochemical behavior during mantle melting (e.g. Ce) was recently found in melt inclusions in the most Mg-rich olivine in 2.7 Ga old komatiites from Canada4 and Zimbabwe5. These data were taken as evidence for a deep hydrated mantle reservoir, probably the transition zone, in the Neoarchean time. In this paper we confirm the mantle source of this H2O by measurement of deuterium to hydrogen ratios in these melt inclusions and present similar data for 3.3 Ga old komatiites from the Barberton Greenstone Belt. Using hydrogen isotopes, we show that the mantle sources of these melts contained excess H2O which implies that a deep mantle hydrated reservoir has been present in the Earth's interior at least since the Paleoarchean. The reconstructed initial hydrogen isotope composition of komatiites is significantly more depleted in deuterium than all surface reservoirs and typical mantle but resembles that in dehydrated subducted slabs. Together with a significant excess of chlorine and a temporal trend of Pb/Ce in the mantle sources of komatiites, these results argue that lithosphere recycling into the deep mantle, arguably via subduction, started before 3.3 Ga. (a un-reviewed version of the manuscript accepted for publication in Nature magazine).
DS1981-0146
1981
Byerly, G.R.Edick, M.J., Byerly, G.R.Post Paleozoic Igneous Activity in the Southeastern United States.Geological Society of America (GSA), Vol. 13, No. 5, P. 236. (abstract.).United States, Gulf Coast, ArkansasPetrology
DS1989-0897
1989
Byerly, G.R.Lowe, D.R., Byerly, G.R., Asaro, F., Kye, F.J.Geological and geochemical record of 3400 Million year old terrestrial meteorite impactsScience, Vol. 245, No. 4921, September 1, pp. 959-962. # 18151South AfricaBarberton area, Impact
DS1991-0933
1991
Byerly, G.R.Kruner, A., Byerly, G.R., Lowe, D.R.Chronology of early Archean granite-greenstone evolution in the BarbertonMountainland, South Africa, based on precise dating by single zirconevaporationEarth and Planetary Science Letters, Vol. 103, No. 1/4, April pp. 41-54South AfricaGeochronology, Greenstone -granite
DS1996-0203
1996
Byerly, G.R.Byerly, G.R., Kroner, A., Walsh, M.M.Prolonged magmatism and time constraints for sediment deposition in the Early Archean Barberton greenstonePrecambrian Research, Vol. 78, No. 1-3, May 1, pp. 125-150South AfricaGreenstone belts, Barberton area
DS2002-0235
2002
Byerly, G.R.Byerly, G.R., Lowe, D.R., Wooden, J.L., Xie, X.An Archean impact layer from the Pilbara and Kaapvaal cratonsScience, No. 5586,Aug. 30, pp. 1325-6.Australia, South AfricaGeodynamices
DS1960-0294
1962
Byers, F.M. JR.Shoemaker, E.M., Roach, C.H., Byers, F.M. JR.Diatremes and Uranium Deposits in the Hopi Buttes ArizonaGeological Society of America (GSA) SPECIAL VOLUME - BUDDINGTON Vol., PP. 327-355.GlobalRelated Rocks, Diatreme
DS1950-0426
1958
Byers, F.M.JR.Shoemaker, E.M., Byers, F.M.JR., Roach, C.H.Diatremes on the Navajo and Hopi Reservation, Arizona. #1United States Geological Survey (USGS) SPECIAL Publishing, No. TEI-740, PP. 158-168.United States, Arizona, Rocky Mountains, Colorado PlateauDiatreme
DS1992-0199
1992
Bykerk-Kauffman, A.Bykerk-Kauffman, A.How faults shape the earth. (overview for the layman)Earth, November pp. 62-67GlobalStructure, Faults - brief overview for layman
DS200612-0421
2006
Bykov, I.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
DS1960-0597
1965
Bykov, I.N.Ruzhitskiy, V.O., Bykov, I.N., et al.Ultrabasic Explosion Breccia of the Russian PlatformDoklady Academy of Sciences ACD. SCI. USSR EARTH SCI. SECTION., Vol. 162, PP. 105-106.RussiaDiatreme
DS201112-0950
2011
Bykov, Kolomiets et al.Shestakov, 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
DS201710-2219
2017
Bykov, M.Cerantola, V., Bykova, E., Kupenko, I., Merlini, M., Ismailova, L., McCammon, C., Bykov, M., Chumakov, A.I., Petitgirard, S., Kantor, I., Svityk, V., Jacobs, J., Hanfland, M., Mezouar, M., Prescher, C., Ruffer, R., Prakapenka, V.B., Duvbovinsky, L.How iron carbonates help form diamonds.Nature Communications, July 18 #15960Mantlecarbonate inclusions
DS201902-0285
2018
Bykov, M.Kiseeva, E.S., Vasiukov, D.M., Wood, B.J., McCammon, C., Stachel, T., Bykov, M., Bykova, E., Chumakov, A., Cerantola, V., Harris, J.W., Dubrovinsky, L.Oxidized iron in garnets from the mantle transition zone.Nature Geoscience, Vol. 11, pp. 144-147. Africa, South Africadeposit - Jagersfontein

Abstract: The oxidation state of iron in Earth’s mantle is well known to depths of approximately 200?km, but has not been characterized in samples from the lowermost upper mantle (200-410?km depth) or the transition zone (410-660?km depth). Natural samples from the deep (>200?km) mantle are extremely rare, and are usually only found as inclusions in diamonds. Here we use synchrotron Mössbauer source spectroscopy complemented by single-crystal X-ray diffraction to measure the oxidation state of Fe in inclusions of ultra-high pressure majoritic garnet in diamond. The garnets show a pronounced increase in oxidation state with depth, with Fe3+/(Fe3++ Fe2+) increasing from 0.08 at approximately 240?km depth to 0.30 at approximately 500?km depth. The latter majorites, which come from pyroxenitic bulk compositions, are twice as rich in Fe3+ as the most oxidized garnets from the shallow mantle. Corresponding oxygen fugacities are above the upper stability limit of Fe metal. This implies that the increase in oxidation state is unconnected to disproportionation of Fe2+ to Fe3+ plus Fe0. Instead, the Fe3+ increase with depth is consistent with the hypothesis that carbonated fluids or melts are the oxidizing agents responsible for the high Fe3+ contents of the inclusions.
DS1998-1555
1998
Bykov, V.N.Voyyakov, S.L., Chaschukhin, I.S., Bykov, V.N.Oxygen thermometry and barometry of chromite bearing ultramafic rocks:South Urals... Olivine-spinel thermometryGeochemistry International, Vol. 36, No. 8, Aug. 1, pp. 706-716.Russia, UralsGeothermometry, Chrome spinels, spectroscopy
DS201312-0247
2013
Bykova, E.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
DS201504-0213
2015
Bykova, E.Prescher, C., Dubrovinsky, L., Bykova, E., Kupenko, I., Glazyrin, K.High Poisson's ration of Earth's inner core explained by carbon alloying.Nature Geoscience, Vol. 8, 3, pp. 220-223.MantleCore, carbon
DS201710-2219
2017
Bykova, E.Cerantola, V., Bykova, E., Kupenko, I., Merlini, M., Ismailova, L., McCammon, C., Bykov, M., Chumakov, A.I., Petitgirard, S., Kantor, I., Svityk, V., Jacobs, J., Hanfland, M., Mezouar, M., Prescher, C., Ruffer, R., Prakapenka, V.B., Duvbovinsky, L.How iron carbonates help form diamonds.Nature Communications, July 18 #15960Mantlecarbonate inclusions
DS201902-0285
2018
Bykova, E.Kiseeva, E.S., Vasiukov, D.M., Wood, B.J., McCammon, C., Stachel, T., Bykov, M., Bykova, E., Chumakov, A., Cerantola, V., Harris, J.W., Dubrovinsky, L.Oxidized iron in garnets from the mantle transition zone.Nature Geoscience, Vol. 11, pp. 144-147. Africa, South Africadeposit - Jagersfontein

Abstract: The oxidation state of iron in Earth’s mantle is well known to depths of approximately 200?km, but has not been characterized in samples from the lowermost upper mantle (200-410?km depth) or the transition zone (410-660?km depth). Natural samples from the deep (>200?km) mantle are extremely rare, and are usually only found as inclusions in diamonds. Here we use synchrotron Mössbauer source spectroscopy complemented by single-crystal X-ray diffraction to measure the oxidation state of Fe in inclusions of ultra-high pressure majoritic garnet in diamond. The garnets show a pronounced increase in oxidation state with depth, with Fe3+/(Fe3++ Fe2+) increasing from 0.08 at approximately 240?km depth to 0.30 at approximately 500?km depth. The latter majorites, which come from pyroxenitic bulk compositions, are twice as rich in Fe3+ as the most oxidized garnets from the shallow mantle. Corresponding oxygen fugacities are above the upper stability limit of Fe metal. This implies that the increase in oxidation state is unconnected to disproportionation of Fe2+ to Fe3+ plus Fe0. Instead, the Fe3+ increase with depth is consistent with the hypothesis that carbonated fluids or melts are the oxidizing agents responsible for the high Fe3+ contents of the inclusions.
DS202109-1454
2021
Bykova, E.Bindi, L., Sinmyo, R., Bykova, E., Ovsyannikov, S.V., McCammon, C., Kupenko, I., Ismailova, L., Dubrovinsky, L., Xie, X.Discovery of Elgoresyite ( Mg,FE)5Si2O9: implications for novel iron magnesium silicates in rocky planetery interiors. Mentions Earth's magmatismACS Earth Space Chemistry, Vol. 5, pp. 2124-2130.Mantlebridgmanite

Abstract: As the most abundant material of rocky planets, high-pressure polymorphs of iron- and aluminum-bearing magnesium silicates have long been sought by both observations and experiments. Meanwhile, it was recently revealed that iron oxides form (FeO)m(Fe2O3)n homologous series above ?10 GPa according to laboratory high-pressure experiments. Here, we report a new high-pressure iron-magnesium silicate, recently approved by the International Mineralogical Association as a new mineral (No. 2020-086) and named elgoresyite, in a shock-induced melt vein of the Suizhou L6 chondrite with a chemistry of (Mg,Fe)5Si2O9. The crystal structure of this new silicate is the same as the iron oxide Fe7O9, strongly suggesting that silicates also form ((Mg,Fe)O)m + n(SiO2)n series that are isostructural to iron oxides via (Mg2+,Fe2+) + Si4+ = 2Fe3+ substitution. To test this hypothesis, the phase relationships of the silicates and iron oxides should be further investigated at higher temperature conditions. Newly found iron-magnesium silicate is a potential constituent mineral in rocky planets with relatively high MgO + FeO content.
DS1988-0098
1988
Bykova, E.V.Bykova, E.V., Igoshin, L.A.Coercivity spectral parameters of magnetites from the alkaline ultrabasic rock complex, ores and carbonatites of the Karelia - Kola region.(Russian)Izv. Akad. Nauk SSSR, Fiz. Zemli., (Russian), No. 6, pp. 92-96RussiaCarbonatite
DS1989-0199
1989
Bykova, E.V.Bykova, E.V.Magnetic properties of rocks and the phase composition of magnetite From the alkaline-ultrabasic massifs Of the Karelia-Kola region (USSR).(Russian)Izv. Akad. Nauk SSSR, Fiz. Zemli, (Russian), No. 10, pp. 93-101RussiaGeophysics, Carbonatite
DS1983-0131
1983
Bykovskii, Y.A.Beloshitskii, V.V., Bykovskii, Y.A., et al.Electromagnetic Radiation of Quasichanneling PositronsRadiation Effects, Vol. 76, No. 3, PP. 93-100.GlobalExperimental Studies, Mineralogy
DS200412-1532
2003
BylundPersonen, L.J., Elming, Mertansen, Pisarvesky, D' Agrilla Filho, Meert, Schmidt, Abrahamsen, BylundPaleomagnetic configuration of continents during the Proterozoic.Tectonophysics, Vol. 375, 1-4, pp. 289-324.MantleMagnetics
DS201503-0144
2015
Byne, K.S.Gaillou, E., Post, J.E., Byne, K.S., Butler, J.E.Study of the Blue Moon diamond. ( from Cullinan)Gems & Gemology, Vol. 50, 4, winter 2014, 9p.Africa, South AfricaDiamonds notable

Abstract: The Blue Moon diamond, discovered in January 2014 at the historic Cullinan mine in South Africa, is of significance from both trade and scientific perspectives. The 29.62 ct rough yielded a 12.03 ct Fancy Vivid blue, Internally Flawless gem. The authors were provided the opportunity to study this rare diamond at the Smithsonian Institution before it went on exhibit at the Natural History Museum of Los Angeles County. Infrared spectroscopy revealed that the amount of uncompensated boron in the diamond was 0.26 ± 0.04 ppm, consistent with measurements of several large type IIb blue diamonds previously studied. After exposure to short-wave ultraviolet light, the Blue Moon displayed orange-red phosphorescence that remained visible for up to 20 seconds. This observation was surprising, as orange-red phosphorescence is typically associated with diamonds of Indian origin, such as the Hope and the Wittelsbach-Graff. Time-resolved phosphorescence spectra exhibited peaks at 660 and 500 nm, typical for natural type II blue diamonds. As with most natural diamonds, the Blue Moon showed strain-induced birefringence.
DS1975-0970
1979
Byrd, E.Byrd, E.The Diamond (1979)London: Macmillan., 223P.South AfricaKimberley, Janlib, Fiction
DS1950-0261
1956
Byrne, F.E.Byrne, F.E., Parish, K.L., Crumpton, C.F.Igneous Intrusions in Riley County, KansasAmerican Association of Petroleum Geologists Bulletin., Vol. 40, PT. 1, PP. 377-380.United States, Kansas, Central StatesRelated Rocks
DS201312-0341
2013
Byrne, K.Guagliardo, P., Byrne, K.,Chapman, J.,Sudarshan, K., Samarin, S., Williams, J.Positron annihilation and optical studies of natural brown type 1 diamonds.Diamond and Related Materials, Vol. 37, pp. 37-40.TechnologyBrown diamonds
DS201212-0100
2012
Byrne, K.S.Byrne, K.S., Anslie, J.D., Chapman, J.G., Luiten, A.N.Optically reversible photochromism in natural pink diamond.Diamond and Related Materials, Vol. 30, pp. 31-36.TechnologyDiamond colour
DS201212-0101
2012
Byrne, K.S.Byrne, K.S., Anstie, J.D., Chapman, J., Luiten, A.N.Infrared micro spectroscopy of natural Argyle pink diamond.Diamond and Related Materials, Vol. 23, March pp. 125-129.AustraliaSpectroscopy
DS201608-1434
2016
Byrne, K.S.Post, J.E., Gaillou, E., Butler, J.E., Byrne, K.S.Investigations into luminescence properties and compositions of colored diamonds.GSA Annual Meeting, Abstract, 1p.TechnologyLuminescence

Abstract: The Smithsonian’s National Gem Collection includes the Hope Diamond and an assortment of other significant fancy-colored diamonds, providing a unique opportunity to conduct detailed and sustained studies on an unprecedented selection of these rare and valuable stones. We present an overview and recent results from our work on pink, blue and chameleon diamonds. Boron causes the blue color of the Hope Diamond and other type IIb diamonds, but scarcity, high value, and the low concentration of B has inhibited B analyses of natural IIb diamonds. We used FTIR and ToF-SIMS to measure concentrations and distributions of B in the Hope and other blue diamonds. ToF-SIMS analyses gave spot B concentrations as high as 8.4 ± 1.1 ppm for the Hope Diamond to less than 0.08 ppm in other blue diamonds and revealed strong zoning of B in some diamonds, which was confirmed by mapping using synchrotron FTIR. Boron is also responsible for the phosphorescence emissions of IIb diamonds, at 660 nm and 500 nm; the emissions are likely caused by donor-acceptor pair recombination processes involving B and other defects. Approximately 50 type I natural pink diamonds were compared using UV-Vis, FTIR, and CL spectroscopies. All stones exhibit pink color zoning, ~1µm thick [111] lamellae, in otherwise colorless diamond. The pink diamonds fall into two groups: 1) those from Argyle in Australia and Santa Elena in Venezuela, and 2) those from other localities. TEM imaging from FIB sections revealed that twinning is the likely mechanism by which plastic deformation is accommodated for the pink diamonds. The deformation creates new centers, including the one responsible for the pink color, which remains unidentified. The differences in the plastic deformation features for the two groups might correlate to the particular geologic conditions under which the diamonds formed. Fluorescence and thermoluminescence experiments on natural chameleon diamonds reveal that an emission band, peaking near 556nm, may be stimulated via a number of different mechanisms. We discuss the implications of our observations for the electronic structure of the 556nm-fluorescing defect center, and the connections to the unidentified color center responsible for chameleon color changes.
DS201610-1900
2016
Byrne, K.S.Post, J.E., Gaillou, E., Butler, J.E., Byrne, K.S.Investigations into the luminescence properties and compositions of colored diamonds. ( blue and pink)GSA An
 
 

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