 | | Journal (article/letter/editorial) | | metamorphism, and metasomatism: The complex history of South African upper-mantle symplectites Stephen W. Field*...Geoscience, and Environmental Science, Tarleton State University, Stephenville, Texas, U.S.A. Abstract...Abstract Symplectites composed of Cr-rich spinel plus one or more of the minerals orthopyroxene, clinopyroxene...create and alter the symplectites. Clinopyroxene + spinel symplectites are the most basic symplectites and...containing amphibole and phlogopite are pyroxene + spinel ± garnet symplectites that have been modified by |  | | Journal (article/letter/editorial) | | for the growth of subsolidus garnet, pyroxene and spinel Received: 5 April 1993 / Accepted: 26 May 1994...xenoliths and in xenoliths in the Jagersfontein Kimberlite, South Africa. Harzburgites of olivine and high-A1...wt%) enstatite contain symplectites of spinel and diopside, or spinel, diopside and lower-A1 (0.8-2.2 wt%)...low-A1 spinel. Symplectites are composed of either spinel + diopside + garnet, or garnet + spinel. Spinel...Spinel diopside garnet symplectites have cores of spinel+diopside, resembling symplectites in harzburgites |  | | Journal (article/letter/editorial) | | CHROMIAN AND ALUMINOUS SPINEL MACROCRYSTS FROM KIMBERLITES IN SOUTHERN AFRICA DANIEL J. SCHULZE§ Department...of the major- and minor-element compositions of spinel-group minerals that occur as single-crystal macrocrysts...macrocrysts in kimberlites from southern Africa (approximately 1500 grains from 20 kimberlites on the Kaapvaal...from a variety of mantle xenoliths from southern Africa and North America (approximately 150 xenoliths)...leads to the conclusion that most macrocrysts of spinel-group minerals are likely to be xenocrysts from |  | | Journal (article/letter/editorial) | | Copyrighl Q Peridotite xenoliths from the Jagersfontein kimberlite pipe: I. Primary and primary-metasomatic...Town, South Africa âIsotope Geochemistry Facility, DEMAST, CSIR, PO Box 395, Pretoria 000 1, South Africa...and textures of peridotite xenoliths from the Jagersfontein kimberlite pipe are reported. The xenoliths...olivine + orthopyroxene + clinopyroxene k garnet & spinel. They are subdivided into coarse and deformed xenoliths...xenoliths have undergone exsolution of pyroxene, spinel, and garnet in their pyroxenes. Primary modal metasomatism |  | | Journal (article/letter/editorial) | | Kimberlite-hosted diamond deposits of southern Africa: A review Matthew Field a,â, Johann Stiefenhofer...Southdale, 2135, South Africa c De Beers Group Services, PO Box 47, Kimberley, South Africa d De Beers Canada...discovery of diamonds in river deposits in central South Africa in the mid nineteenth century, it was at Kimberley...economic and industrial development of southern Africa. Following the discoveries at Kimberley, even more...more valuable deposits were discovered in South Africa and Botswana in particular, but also in Lesotho |  | Peslier, A.H., Woodland, A.B., Bell, D.R., Lazarov, M., Lapen, T.J. (2012) Metasomatic control of water contents in the Kaapvaal cratonic mantle. Geochimica et Cosmochimica Acta, 97. 213-246 doi:10.1016/j.gca.2012.08.028 | Journal (article/letter/editorial) | | School of Earth and Space Exploration, Arizona State University, 550 East Tyler Mall, Tempe, AZ 85287...Kaapvaal craton from Finsch, Kimberley, Jagersfontein (South Africa), Letseng-La-Terae, and Liqhobong (Lesotho)...Ca, Ti and water at the edge of garnets at Jagersfontein, and the overall crystallization of garnet with...content of olivines with decreasing pressure at Finsch Mine. H2O/Ce ratios of melts in equilibrium with Kaapvaal...Archean at Kimberley and from the Proterozoic at Jagersfontein. Combined water with LuâHf and SmâNd isotopic |  | | Journal (article/letter/editorial) | | upper mantle beneath the Kaapvaal craton, Southern Africa A.B. Woodland , M. Koch Mineralogisches Institut...varies with depth, Fe3ĂŸ contents in garnet and spinel from peridotite xenoliths were determined by Mo«ssbauer...the Kaapvaal craton in South Africa (Kimberley, Jagersfontein, Frank Smith Mine, Monastery) and Lesotho...coverage from V80 to 220 km. For the Lesotho and South African xenoliths there is a systematic, but not...decrease of V3 log units. At shallow depths, where spinel peridotites are stable, vlogfO2 values of VFMQ31 |  | | Book | | Phase 5. Sample Treatment D) World Production E) South African Diamond Occurrences 1. Large Kimberlite...Koffiefontein 2. Smaller mineralised kimberlites in South Africa 2.1 The Oaks 2.2 The Zebediela Kimberlites 2...and Virginia 2.6 The Loxtondal Cluster 2.7 Jagersfontein 2.8 Lace and Voorspoed 3. Alluvial Deposits... 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 |  | Pearson, D. G., Boyd, F. R., Haggerty, S. E., Pasteris, J. D., Field, S. W., Nixon, P. H., Pokhilenko, N. P. (1994) The characterisation and origin of graphite in cratonic lithospheric mantle: a petrological carbon isotope and Raman spectroscopic study. Contributions to Mineralogy and Petrology, 115 (4) 449-466 doi:10.1007/bf00320978 | Journal (article/letter/editorial) | | MO 63130, USA 5 Departmentof Geology,Stockton State College,Pomona,NJ 08240, USA 6 Departmentof Earth...xenoliths from the Kaapvaal craton of southern Africa and the Siberian craton, Russia, have been studied...diamond (and graphite?) crystallisation in southern Africa occurred within the time span associated with the...kimberlite localities; 24 samples arc from southern Africa and 2 arc from Siberia. Of these, 19 are lherzolites...margin of the Kaapvaal craton (Kilnberley, Jagersfontein and northern Lesotho), the Premier pipe in the |  | | Journal (article/letter/editorial) | | lithospheric mantle beneath the Kaapvaal craton, South Africa Virginie Baptiste â, AndrĂ©a Tommasi, Sylvie...olivine may be representative of the present-day state of the Kaapvaal mantle, implying that extensive...roots of some cratons, such as the Kaapvaal in South Africa, survived from reworking by plate tectonics... 2. Geological setting The Kaapvaal craton (South Africa) is an assemblage of Archean terranes that extends...ages ranging from 1.2 Ga to 87 Ma: Kimberley, Jagersfontein, Monastery, Lentseng, De Beers, Finsch, Kamfersdam |  | | Journal (article/letter/editorial) | | in the kimberlites of Lesotho, Rhodesia, Sauth Africa, and Tanzania. Six new mineral assemblages, which...olivine-orthopyroxene-clinopyroxene-amphibole; garnet-spinel; garnet-clinopyroxene-quartz; garnet-clinopyroxene-high...sanidine-eclogite plus scapolite.amphibole-eclogite, and garnet-spinel plus garnet-corundum rocks form the new groups...lengths for the last-named phase. The spinel in the garnet-spinel rocks is essentially pleonaste but it...Johannesburg, South Ah'ica. ** Present address: School of Applied Geology, University of New South Wales, Kensington |  | | Journal (article/letter/editorial) | | and the metasomatism of eclogites from the Jagersfontein Kimberlite: Punctuated transport and implications...xenoliths and associated metasomatism from the Jagersfontein Kimberlite are presented with the objectives...establishing possible links to cratonic magmatism. Jagersfontein eclogites are primarily bimineralic garnet 1...the dominant metasomatic minerals, with accessory spinel, feldspar, and serpentine. Garnets are py39 to...garnet, adjacent to phlogopite, and as relicts in spinel-bearing subassemblages. Phlogopite and amphibole |  | | Journal (article/letter/editorial) | | chemistry of new titanates from the Jagersfontein kimberlite, South Africa: Implications for metasomatism...relatively common in kimberlites, are ilmenite, chrome-spinel, and perovskite. None of these minerals, however...similar in optical properties to ilmenite, rutile and spinel, has broad implications to mantle geochemistry...the Jagersfontein kimberlite, 130 km SE of the Kimberley diatrcme complex in the Republic of South Africa...R~CKARD, 1977; JONES et al., 1982). Other grains are free of silicate inclusions (e.g. ilmenites and chromites) |  | | Journal (article/letter/editorial) | | Geochemistry, University of Cape Town, Rondebosch, South Africa 7700 Received October 2, 1989 / Accepted January...Oxygen fugacities are calculated for olivine - spinel 4- orthopyroxene assemblages recovered from diamonds...thermobarometric oxygen fugacities are obtained for chrome spinel-garnet peridotites and diamonds from several other...Calculated equilibrium temperatures for olivine-spinel pairs from Dokolwayo diamonds and concentrate indicate...subsolidus conditions. Introduction The oxidation state of the mantle is an important parameter, because |  | | Journal (article/letter/editorial) | | biotite, 453 Alkali feldspar solvus, 59 Allanite, New South Wales, anal., opt., 652; metamict, .4remtal, North...gabbros, clinopyroxene, kaersutite, plagioclase, spinel, 259 Amphibole, see Hornblende, Riebeckite, Actinolite...Antigorite, infra-red spectra, I97 Aorangi gold mine, Nelson, South Island, New Zeaiatul, cymrite, 31 I Apatite...see KASHKAI(M.-A.), 5OI Back Creek, Pambula, New South Wales, cookcite, diaspore, pyrophyllite, 765 BAILEY... 263 922 ALPHABETICAL Bambollita mine (-~- La Oriental mine), Moctezama, Sonora, Mexico, carlfriesite |  | | Journal (article/letter/editorial) | | and Petrology 9 by Springer-Verlag 1978 Pyrope-Spinel (Alkremite) Xenoliths From Kimberlite P.H. Nixon...Geochemistry, University of Cape Town, Cape Town, South Africa Abstract. Xenoliths consisting of two thirds...hercynite-bearing spinel with minor chromium, from Bellsbank and Jagersfontein kimberlites, South Africa, are compared...(PYs0) are capable of being formed. The garnet spinel xenoliths are considered to have become separated...Cluster Re8 Fig. 1. Location of Bellsbank, Jagersfontein and Roberts Victor kimberlite occurrences Introduction |  | | Report (issue) | | 10.361 c = 20.65 Z=3 X-ray Powder Pattern: South Africa. 2.14 (100), 1.44 (100), 2.25 (90), 2.99 (80)...05 ThO2 0.01 (1) Jagersfontein, Bultfontein, and Kolonkwanen kimberlites, South Africa; by electron microprobe...concentrates from metasomatized kimberlite (South Africa). Association: Lindsleyite, olivine, diopside...barite, NbâCr rutile, MgâCr spinel, ilmenite, perovskite, titanite (South Africa); yimengite (Shandong Province...Distribution: From the Jagersfontein diamond mine, Free State, and the Bultfontein diamond mine and Kolonkwanen |  | | Journal (article/letter/editorial) | | experimentally observed conversion of olivine (α-phase) into spinel-like wadsleyite (ÎČ-phase), with roughly an 8% increase...transforms to ringwoodite (Îł-phase), which has a true spinel structure and is another 2% denser. This latter...al. (1984) on kimberlite dikes near Orrorroo in South Australia. These authors noted that if ferropericlase...from this occurrence and the Koffiefontein Mine in South Africa were indeed syngenetic, then, because of...Brazil (reviewed in Harte et al. 1999). 0 CRUST SPINEL GARNET SP L IT HEN H O S O AST 100 HERE PHERE |  | | Journal (article/letter/editorial) | | Low-calcium garnet harzburgites from southern Africa: their relations to craton structure and diamond...predominantly coarse but one specimen from Jagersfontein and another from Premier have deformed textures...xenoliths of diopside-free dunite and harzburgite that contain low-Ca garnet in southern Africa (Danchin and Boyd...u n c e d association with cratons. In southern Africa these garnets are found only within the area of...for harzburgites from three South African localities, Premier, Jagersfontein and the Kimberley dumps (Bultfontein |  | | Journal (article/letter/editorial) | | and eclogitexenolithsfrom Bellsbank and Jagersfontein,South Africa Rrcueno A. ExLev, JosepH V. Sutrn Department...eclogites(garnet-clinopyroxene) Alkremites(garnet-spinel-+orundum), from BellsbankandJagersfontein evidenceof...spinels.Detailedvariationsof Cr andTi in garnetand spinel requireseveralparentalmagmas.Corundumin alkremitescontains0...similar amountsof coarsegarnet rich garnet and spinel occur rarely in kimberlites (S. and interstitial...interstitial clinopyroxene, which are altered next to Africa,Mathiaset aI.,1970;Nixon etal., 1978;U.S.S.R., grain-boundary |  | | Journal (article/letter/editorial) | | of some peridotites from the Kaapvaal craton (South Africa) Received: 27 October 2005 / Accepted: 15 January...in peridotite xenoliths from Kaapvaal craton (South Africa) provided compelling evidence for the occurrence...high-grade Archean Terranes: the Western Terrane, the South-Eastern Terrane, the Central Terrane and the Pietermaritz...(De Beers Mine; Bultfontein, Kimberley, South Africa) and Jagersfontein (Fig. 1). In the South-Eastern...Gurney 1986; Nixon 1987; Boyd 1989). Those of Jagersfontein and Bultfontein samples are available in Hops |  | | Journal (article/letter/editorial) | | Upper phlogopite Canada Implications in a mantle Mine derived xenolith of kimberlite, Ontario , Canada:...During a petrological study of the Upper Canada Mine kimberlite dyke, Ontario (Arima et al., 1986a...is exposed in a under ground of the Upper Canada Mine, in the vicin ity of Kirkland Lake, Ontario, Canada...The petrology and mineralogy of the Upper Canada Mine kimberlite has been described by Lee and Lawrence...this area (Fig. 1). The Upper Canada hypabyssal Mine kimberlite is a calcite, to lite sparcely only |  | | Journal (article/letter/editorial) | | varieties of aluminous assemblages from the Jagersfontein kimberlite are recognized as xenoliths consisting... K-pargasite, fassaitic pyroxene and secondary spinel. Bulk-rock major elements are depleted in SiOr...been noted in the Bellsbank and Jagersfontein kimberlites, South Africa (NIXON et al., 1978; HAGGERTY,...new varieties of peraluminous xenoliths from Jagersfontein which are closely related to alkremites but...+ garnet) and corgaspinite (corundum + garnet + spinel) for these assemblages which, although chemically |  | | Journal (article/letter/editorial) | | Geochemistry University of Cape Town, Republic of South Africa arro R. V. DnNcurrq2 Anglo-American Corporation...ResearchLaboratory Crown Mines, Johannesburg, Republic of South Africa Abstract Two new opaquemineralsare describedfrom...Presentaddress: Stockdale Prospectint-Ltd., 60 Wiison Street, South yarra, Victoria 3141,Australia. 0003-004x/83/0505-M94$02...from the De Beers kimberlite in the Republic of South Africa (RSA) and the mineral has since been recognized...recognized in heavy mineral concentrates from the Jagersfontein mine, the Kolonkwanen kimberlite, and in one veined |  | | Journal (article/letter/editorial) | | of garnet xenocrysts from 32 kimberlites from South Africa and North America (4500 garnets), Schulze (1993... The crustal Ca-poor pyropes are essentially Cr-free, however, whereas similarly magnesian and Ca-poor...ââpyroxeniteââ. Rocks rich in pyroxene and poor in, or free of, olivine are common, though typically not abundant...pyroxenites, especially those containing primary spinel (e.g., Eggler et al., 1987), are probably more...ilmenite, apatite, zircon, phlogopite, titanite, spinel, amphibole, sulphides), and their garnets and clinopyroxenes |
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