 | | Journal (article/letter/editorial) | | W. HARRIS~ of Geosciences, The Pennsylvania State University, University Park, PA 16802, USA ‘Department...mineral inclusions among diamond suites from Koffiefontein, Orapa, Premier, Roberts Victor, Jagersfontein...inclusions of the African diamonds (mostly from Koffiefontein) could have been in chemical equilibrium with...relative abundance of silicate inclusions in Koffiefontein diamonds (93% peridotitic, 7% eclogitic) and...kimberlites (Koffiefontein, Premier, Roberts Victor, and Jagersfontein, in South Africa, and Orapa, in |  | Meyer, Nicole A., Wenz, Michelle D., Walsh, James P.S., Jacobsen, Steven D., Locock, Andrew J., Harris, Jeffrey W. (2019) Goldschmidtite, (K,REE,Sr)(Nb,Cr)O3: A new perovskite supergroup mineral found in diamond from Koffiefontein, South Africa. American Mineralogist, 104 (9) 1345-1350 doi:10.2138/am-2019-6937 | Journal (article/letter/editorial) | | supergroup mineral found in diamond from Koffiefontein, South Africa Nicole A. Meyer1,*, Michelle D. Wenz2...an inclusion in a diamond from the Koffiefontein pipe in South Africa. In addition to the dark green and...(websteritic paragenesis) and an intergrowth of chromite, Mg-silicate, and unidentified K-Sr-REE-Nb-oxide...peak at 815 cm–1, which is possibly a result of local ordering of Nb and Cr at the B site. The name goldschmidtite...niobium, mantle, diamond inclusion, new mineral, Koffiefontein, Kaapvaal Introduction Diamonds are carriers |  | | Journal (article/letter/editorial) | | diamonds from the Jagersfontein and Koffiefontein kimberlite, South Africa PETER DEINES,’J. W. HARRIS,’ and...GURNEYS ‘Department of Geosciences, The Pennsylvania State University, University Park, PA 16802, USA 2Department...Department, University of Cape Town, Rondebosch 7700, South Africa (Received September 19, 1990; accepted in revised...diamonds, from the Jagersfontein kimberlite, South Africa, have a 613Crange from - 18.9 to -24.4%0 vs...vs. PDB. Deep diamonds from the nearby Koffiefontein mine have 613Cvalues between -2.9 and -6.1 %o.At these |  | | Journal (article/letter/editorial) | | Microinclusions analyzed in a coated diamond from the Diavik mine in Canada comprise peridotitic minerals and fluids...brine found in cloudy octahedral diamonds from South Africa and carbonatitic melt analyzed in cubic diamonds...a mantle source not significantly influenced by local heterogeneities. D 2004 Elsevier B.V. All rights...with brine inclusions in cloudy diamonds from Koffiefontein. This, together with the evidence for metasomatism...one concentrically zoned diamond from the Diavik mine in Lac de Gras, Slave Craton, Canada. Microinclusions |  | | Journal (article/letter/editorial) | | inclusions from De Beers Pool diamonds, Kimberley, South Africa D. Phillips a,*, J.W. Harris b, K.S. Viljoen...Mines Ltd., P.O. Box 82232, Southdale, 2135, South Africa b Received 27 June 2003; accepted 14 December...important De Beers Pool kimberlites in Kimberley, South Africa, are characterised by harzburgitic compositions...intergrowths, with garnet + orthopyroxene F chromite F olivine and chromite + olivine assemblages dominant. More...garnets exhibit intermediate compositions. Most chromite inclusions contain 63 – 67 wt.% Cr2O3 and < 0 |  | | Book | | Phase 5. Sample Treatment D) World Production E) South African Diamond Occurrences 1. Large Kimberlite...1.4 Kimberley 1.5 Koffiefontein 2. Smaller mineralised kimberlites in South Africa 2.1 The Oaks 2.2 The... their relative production contributions in South Africa were, primary (kimberlite) 8.63 million carats...Premier mine. The proportion of gems in the West Coast marine deposits is over 98%. The MIBA mine in the...the Congo and the Argyle mine in Australia have an average gem content of only 5%. The dispersal of diamonds |  | | Journal (article/letter/editorial) | | with similar datasets available for Ekati and Koffiefontein kimberlites, suggest a general pattern of metasomatic...peridotitic garnet and pyroxenes is expected in local mantle segments during fibrous diamond production...et al. (2004) analysed mineral inclusions in Koffiefontein diamonds (RSA, Kaapvaal craton) containing a...fibrous and non-fibrous diamonds at Panda (Ekati mine, Canada, Slave craton) and concluded that metasomatism...accompanies formation of fibrous diamond from a Diavik mine kimberlite (Slave craton) and a metaconglomerate |  | | Journal (article/letter/editorial) | | Phase relations and second critical endpoint in a K-free eclogite at 700 to 1400 °C. Earth Planet. Sci. Lett...rate is the same in the kimberlitic melts with a free fluid phase and in a pure H2O or CO2 fluid, suggesting...fibrous dia- monds typically has a low aggregation state (a-centers) suggesting short mantle residence time...Mg–Fe silicate, Chromite Saline and carbonatitic HDF Silicic HDF Cr-diopside, Chromite, Olivine – + ...from the Koffiefontein mine South-Africa; diamonds UB 5– 41 and UB 3105 are from Yubileinaya mine, Russia; |  | | Journal (article/letter/editorial) | | G.P. Kudryavtseva Department ofGeology, Moscow State University, 1198999 Moscow (U.S.S.R.) (Received...Prilenie Priangarie Ural Fmsh Koffiefontem Koffiefontein Premier Premier Roberts Victor Roberts Victor...(1977) claim a dominance of olivine (53.0%) and chromite (43.6%), whereas Bulanova (1985) showed that sulphides...%) clearly predominate over olivine (2.2%) and chromite (5.5%). Yefimova and 213 INCLUSION·BEARING...composition Fe3S21 sphalerite, wUstite, (?) coesite, chromite, magnetite, hematite, olivine, pyrope, o - area |  | | Journal (article/letter/editorial) | | productions from Panda (Ekati Mine) and Snap Lake with those from southern Africa shows significant differences:...only just commenced with the opening of the Ekati Mine (Fig. 1) in 1998. As a consequence, only few systematic...Sable and Jay diatremes, which are part of the Ekati Mine, located about 25 km north of Lac de Gras (see Carlson...new analyses from the Panda diatreme of the Ekati mine. For the Southern Slave (Fig. 1), Pokhilenko et...Bultfontein, De Beers Pool, Finsch, Jagersfontein, Koffiefontein, Letlakane, Letseng-la-Terai, Monastery, Premier |  | | Journal (article/letter/editorial) | | composition of the clinopyroxene in orthopyroxene-free assemblages would be little affected by a variation...lithospheric keels of cratons, both the orthopyroxene-free polymineralic inclusions and the isolated inclusions...and would therefore reflect the ambient thermal state of the mantle at the time of eruption. Taking into...cases of touching, orthopyroxene-bearing, garnet-free inclusions may underestimation of P exceed 1 GPa...such low-Al diopside were indeed part of garnet-free assemblages, its pressure of equilibration could |  | | Report (issue) | | 04 6.67 6.82 11.53 98.53 (1) Koffiefontein kimberlite pipe, South Africa; average of 11 electron microprobe...augite, chromite, Mg-silicate, an unidentified K-Sr-REE-Nb-oxide. Distribution: From the Koffiefontein kimberlite... ~ 80 km SSE of Kimberley, Kaapvaal Craton, South Africa. Name: Honors geochemist Victor Moritz Goldschmidt...supergroup mineral found in diamond from Koffiefontein, South Africa. Amer. Mineral., 104(9), 1345-1350. |  | | Journal (article/letter/editorial) | | the lithospheric seismic structure of Southern Africa Steven B. Shirey a,*, Jeffrey W. Harris b, Stephen... Rondebosch 7701, South Africa d Department of Geological Sciences, Arizona State University, Box 871404...Department of Mineral Sciences, The Pennsylvania State University, University Park, PA, USA g De Beers...GeoScience Centre, PO Box 82232, Southdale, 2135, South Africa Abstract The Archean lithospheric mantle beneath...beneath the Kaapvaal – Zimbabwe craton of Southern Africa shows F 1% variations in seismic P-wave velocity |  | | Journal (article/letter/editorial) | | Geochemistry, Univ, of Cape Town, Rondebosch, 7700, South Africa ReceivedJune 24, 1991 / AcceptedOctober 11,...orthopyroxene inclusions (DI) in >60 diamonds from southern Africa, and in concentrate garnets from the host kimberlites...(P-type), dominated by olivine, orthopyroxene, chromite and chromepyrope garnet; and the eclogitic (E-type)...s f r o m the Finsch, R o b e r t s Victor, Koffiefontein, O r a p a , J a g e r s f o n t e i n a n d...their Fo content; most of those from the Finsch mine group tightly in terms of both Fo and Ca (Fig. 3) |  | | Journal (article/letter/editorial) | | isotope ratios, nitrogen content and aggregation state, and inclusion chemistry of diamonds from Jwaneng...3 ~Department of Geosciences, The Pennsylvania State University, University Park, Pennsylvania 16802...Geochemistry, University of Capetown. Rondebosh 7700, South Africa (Received November 19, 1996; accepted in revisedjorm...equilibration temperatures, the nitrogen content, and the state of nitrogen aggregation in the host diamonds. Copyright...properties as shape, color, state of deformation, N content and aggregation state, as well as the diamond |  | | Journal (article/letter/editorial) | | Geochemistry, University of Cape Town, Rondebosch, South Africa 7700 Received October 2, 1989 / Accepted January...subsolidus conditions. Introduction The oxidation state of the mantle is an important parameter, because...formation of the core-mantle system. The redox state of the mantle, together with temperature and pressure...RHOD K-P Cr203 Kakanui - Pyrope Synthetic Rutile Chromite 52-NLl1 Ilmenite, Ilmenite Mountains, USSR Rhodonite...Unlike the majority of kimberlites in southern Africa it predates the Stormsberg volcanism which, in |  | | Journal (article/letter/editorial) | | the Precambrian mantle lithosphere of southern Africa Steven B. Shirey Department of Terrestrial Magnetism...Sciences, University of Cape Town Rondebosch 7701, South Africa, e-mail: shr@geology.uct.ac.za Jeffrey W. Harris...Geological Society of South Africa ABSTRACT Two decades of diamond research in southern Africa allow the age...diamonds from the Kimberley area kimberlites, Koffiefontein, Orapa and Jwaneng have Re-Os isotopic ages...of Archean lithosphere, particularly in southern Africa, is to relate lithospheric structure to the age |  | | Journal (article/letter/editorial) | | Venetia, South Africa PETER DEINES,1,* FANUS VILJOEN,2 and J. W. HARRIS3 1 The Pennsylvania State University...Geoscience Centre, PO Box 82232, Southdale, 2135, South Africa 3 Division of Earth Sciences, University of...of 199 diamonds from the Venetia kimberlite, South Africa, whose mineral inclusion chemistry had already...multi-modal. Examination of the inclusion chemistry (chromite, olivine, garnet) as a function of the carbon...Complex from the northern Marginal Zone; in the south, the Palala Shear Zone forms the boundary to the |  | | Journal (article/letter/editorial) | | diamonds from the Finsch Group II kimberlite, South Africa, and identified two diamond populations: ‘Finsch...and the neighbouring Group I kimberlites at Koffiefontein and De Beers Pool indicate that a substantial...diamonds from the Finsch Group II kimberlite, South Africa. We document two diamond populations differing...differing in their nitrogen aggregation state and HDF compositions, and discuss the type and timing of the...microinclusion-bearing diamonds from neighboring kimberlites (Koffiefontein and De Beers Pool), we explore the recent sequence |  | | Journal (article/letter/editorial) | | Sciences, University of Cape Town, Rondebosch 7701, South Africa c Division of Earth Sciences, University of...Abstract Two decades of diamond research in southern Africa allow the age, average N content and carbon composition...diamonds from the Kimberley area kimberlites, Koffiefontein, Orapa and Jwaneng have Re – Os isotopic ages...and the Limpopo mobile belt known as the Southern Africa Seismic Experiment (SASE; James et al., 2001; James...averaged. This cylinder is centered below each diamond mine and extends from 150 to 225 km depth. Seismic data |  | | Journal (article/letter/editorial) | | Cr-pyrope, orthopyroxene, diopsidic clinopyroxene, Mg-chromite), eclogitic (pyrope–almandine garnet and omphacitic...fluid in a fibrous diamond coat from the Diavik Mine (Canada) range in composition from Na–K–Cl brine...from Koffiefontein (South Africa) [4]. Additionally, primary mantle minerals (Cr-diopside, chromite and...the micro-inclusions in cloudy diamonds from Koffiefontein [5]. However, single phase mineral inclusions...garnet, pyroxene (Cr-diopside and enstatite), chromite and ilmenite [16]. The lithosphere below the Slave |  | | Journal (article/letter/editorial) | | of Cape Town, Rondebosch, 7700, Republic of South Africa of Geological Sciences and Geological Engineering...and ages to individual inclusion-free diamonds with our current state of knowledge. Introduction TERRESTRIAL...P O Box 38668, Pinelands, 7430. Republic of South Africa. 0361-0128/10/3894/689-24 the mantle, as far...population of xenocrystic diamonds contributing to run-of-mine production. Evidence is accumulating that the diamond-forming...localities at craton margins, such as Jagersfontein, South Africa. The diamonds typically have low N contents |  | | Journal (article/letter/editorial) | | Sample descriptions Three diamonds from the Diavik mine, Lac de Gras, Slave Craton, Canada, were analyzed...One fibrous cube, UB-5-41, from the Yubileinaya mine in Siberia with a central microinclusion-rich zone...1e and 1f). FIB milling was conducted in the oil-free, high-vacuum chamber of an FEI FIB2000 instrument...spectrum (Egerton 1996). The electron inelastic mean free path in diamond was calculated using the formalism...2002). (d) Mica-bearing diamond KFF-166 from Koffiefontein (Izraeli et al. 2004). × 1.7 μm2 area in the |  | | Journal (article/letter/editorial) | | includes exceptionally high Cr2O3 contents in Mg-chromite (70.7 wt.%) and clinopyroxene (3.6 wt.%). Garnet-olivine...from Namibia magmas, a detailed picture on the state of the subcontinental lithospheric mantle has emerged...Single inclusions Pyrope garnet Orthopyroxene Mg-chromite Olivine Clinopyroxene Inclusions pairs Garnet...orthopyroxene + olivine Garnet + orthopyroxene + chromite Garnet + orthopyroxene + olivine Total diamonds...dominantly Ca-undersaturated, indicating clinopyroxene-free sources, with only one garnet being lherzolitic |  | | Journal (article/letter/editorial) | | the mantle below the Orapa kimberlite, Botswana, Africa PETER DEINES,’ J. W. HARRIS,’ and J. J. GURNEY...3 ‘Department of Geosciences, The Pennsylvania State University, University Park, PA 16802, USA ‘Department...Geochemistry, University of Capetown, Rondebosch 7700, South Africa (Received June 16, 1992; accepted in revised...content (897 + 17 1 ppm) and low nitrogen aggregation state. They are thought to have been derived from shallow...-5 and -7960. Their nitrogen content is low and state of aggregation high. Pressure-temperature (P-T) |
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