 | | 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...(Zuyev 1971). In a study of peridotites from South Africa (Field and Haggerty 1994), up to one third of...papers. Williams (1932) suggested that spinel-enstatite-olivine symplectites were eutectic intergrowths...in upper mantle peridotite xenoliths included in South African kimberlites. Symplectites are described |  | | Journal (article/letter/editorial) | | xenoliths and in xenoliths in the Jagersfontein Kimberlite, South Africa. Harzburgites of olivine and high-A1...6 wt%), Ca (0.6-0.9 wt%) and Cr (0.3~.9 wt%) enstatite contain symplectites of spinel and diopside, or...2 wt%), Ca (0.10.4 wt%) and Cr (0.02-0.8 wt%) enstatite. From textures and mineral chemistries these symplectites...unmixing and migration from A1-Ca-Cr discrete enstatite to adjoining mineral interfaces. Garnet harzburgites...wt%), Ca (0.1-0.5 wt%), and Cr (0.1 0.3 wt%) enstatite and smaller interstitial garnet, diopside, and |  | | Book (volume) | | rise and development of the diamond mines of South Africa, from an historical, economic and technical...fields when the mines in the Kimberley and Jagersfontein areas were the only diamond mines being worked...collect during my many visits to all parts of South Africa where kimberlite deposits occurred and the filing...Mines, Limited, and Consulting Engineer to the Jagersfontein and Koffy fontein mines. In later years I felt...was necessary to file * "The Diamond Mines of South Africa," by Gardner F. Williams. V . Vl l I I |  | 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) | | Kimberlite-hosted diamond deposits of southern Africa: A review Matthew Field a,⁎, 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 |  | | Journal (article/letter/editorial) | | and certain megacrysts from the Jagersfontein kimberlite, South Africa J.B. DAWSON' and J.V. SMITH2 'Department...and certain megacrysts from the Jagersfontein kimberlite, South Africa. In: W.L. Griffin (Editor), Second...to phases in the eclogite xenoliths from the Jagersfontein kimberlite are ascribed to fragmentation of...compositionally from other megacrysts from Jagersfontein and those found at other localities that are...(up to 15 cm) monomineralic grams of olivine, enstatite/bronzite, clinopyroxene, garnet, ilmenite and |  | | Book (volume) | | PETROGRAPHICAL STUDY OF THE COGNATE INCLUSIONS OLIVINE ENSTATITE BRONZITE GARNET KELYPHITE - CHEMICAL COMPOSITION...DIAMOND-BEARING ALLUVIAL GRAVELS OF THE UNION OF SOUTH AFRICA DIAMOND-BEARING GRAVELS DRAINAGE WEATHERING...SYSTEMS THE ORIGIN OF THE ALLUVIAL DIAMONDS THE SOUTH-WEST AFRICA DIAMOND DEPOSITS THE VAAL RIVER ALLUVIAL GRAVELS...Plate No. 96. THIN SECTION (359, X 12) FONTEIN MINE BRONZITE PERIDOTITE FROM JAGERS facing page 368...following plate MINE THIN SECTION (8, x 12) BRONZITE PERIDOTITE FROM BuLTFONTEIN 98. MINE ,, ,, 99. THIN |  | | Journal (article/letter/editorial) | | Ultramafic nodules from the Kimberley pipes, South Africa F. R. BOYD Geophysical Laboratory, Carnegie...collected in a number of other areas in southern Africa in two important respects: (1) There are no sheared...mosaic-porphyroclastic. In most nodule suites from southern Africa and elsewhere in the world, these low-temperature...origin for the garnet lherzolites and for the enstatite discrete nodules shows an inflected geotherm for_Kimberley...lherzolites at Bultfontein is 55% olivine, 28% enstatite, 10% garnet, 4% diopside and 3% phlogopite. CHEN |  | | Journal (article/letter/editorial) | | Copyrighl Q Peridotite xenoliths from the Jagersfontein kimberlite pipe: I. Primary and primary-metasomatic...Town, South Africa ‘Isotope 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...distinctive features of the low-temperature Jagersfontein xenoliths, namely exsolution and very low equilibration...lithophilic elements (LILs) in concentrates from the Jagersfontein kimberlite. At Bultfontein these minerals are |  | | 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...lherzolites. Both the harzburgites and lherzolites are enstatite-rich with m g numbers [100.Mg/(Mg + Fetotal)]...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 |  | | 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) | | biotite, 453 Alkali feldspar solvus, 59 Allanite, New South Wales, anal., opt., 652; metamict, .4remtal, North...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...thermal decomposition of, thermogravimctry, 79; S.-W. Africa, intergrowth with prehnite, 526 BLACIC (J. D.) |  | | Report (issue) | | SURVEY OF SOUTH AFRICA COUNCIL FOR GEOSCIENCE GEOLOGICAL SURVEY OF SOUTH AFRICA MINERALOGY OF SOUTH AFRICA:... COUNCIL FOR GEOSCIENCE GEOLOGICAL SURVEY OF SOUTH AFRICA Scientific Editor R.D. Dixon Linguistic and...Council for Geoscience (Geological Survey of South Africa), 280 Pretoria Street, Silverton, Pretoria or........................... 69 5.1 Overview of South African Occurrences ..............................LAYEREDSUITE,BUSHVELDCOMPLEX.... 111 MINERALOGY OF SOUTH AFRICA: TYPE-MINERAL SPECIES AND TYPE-MINERAL NAMES |  | | Journal (article/letter/editorial) | | 1990 Silicate-bearingrutile-dominatednodulesfrom South African kimberlites: Metasomatizedcumulates DaNrrr...Kampfersdam and Jagersfonteinkimberlite pipes in South Africa contain euhedral olivines and spinels,graphic...and ilmenite are graphically intergrown with enstatite. These are interpreted as having crystallized...Tollo and Haggerty,1987),and Jagersfontein and Kampfersdam in South Africa (Haggerty, 1983; Schulze,1983;...nodules from the Jagersfonteinkimberlite in South Africa, eachof which contains graphic interyrowths |  | | Journal (article/letter/editorial) | | understand the nature of the upper mantle in southern Africa and the processes that have modified it, including...within or near the Kaapvaal craton 1 of southern Africa (Figure 1) and it is the study of the geological...from northern Lesotho (Nixon & Boyd 1973b), Jagersfontein (MacGregor 1975), and Frank Smith '(Boyd 1974)...harzburgite nodules from kimberJites in southern Africa. Pyrolite quoted from Ringwood (1975). Table 1...African inclusions: olivine 40-75, orthopyroxene (enstatite) 5-50, clinopyroxene (chromium diop side) 0-20 |  | | Journal (article/letter/editorial) | | the kimberlites the Kimberley area and Jagersfontein, South Africa of F. R. BOYD Geophysical Laboratory...Granny Smith nodules, in the Kimberley area and Jagersfontein kimberlites are sheared, commonly contain lenticles...and megacryst suites from the Kimberley and Jagersfontein pipes. The size of this fraction is difficult...Bultfontein and Kampfersdam dumps and the DeBeers mine. Megacrysts with similar petrographic charac- teristics...compositions have been found in abundance at the Jagersfontein mine and are also present in the Hanover pipe |  | 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 Lu–Hf and Sm–Nd isotopic |  | | Journal (article/letter/editorial) | | (megacrysts) from the Kaapvaal craton of southern Africa, and provide direct evidence that some garnet in...affected by exsolution of garnet from orthopyroxene (enstatite) remains enigmatic; much more widely reported...HIGHLY-REFRACTORY ARCHEAN LITHOSPHERE (BD1366) from Monastery mine, Lesotho (Aoki et al., 1980; Dawson, 2004; Dawson...lamellae in a large porphyroclast of orthopyroxene (enstatite) or as a ‘necklace’ along orthopyroxene grain...with deformation textures (kink banding) in the enstatite host and appear to be linked to strain of the |  | | Journal (article/letter/editorial) | | upper mantle beneath the Kaapvaal craton, Southern Africa A.B. Woodland , M. Koch Mineralogisches Institut...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...cannot be treated as monolithic in terms of redox state. The early development of the Earth’s atmosphere...capacity to react with O2 and inhibit the build-up of free O2 in the early atmosphere. ? 2003 Elsevier B.V |  | | Journal (article/letter/editorial) | | in the kimberlites of Lesotho, Rhodesia, Sauth Africa, and Tanzania. Six new mineral assemblages, which...Johannesburg, South Ah'ica. ** Present address: School of Applied Geology, University of New South Wales, Kensington...specimens are nearly all from kimberlites in South Africa, Lesotho and Rhodesia. We do not claim t h a...nearly pure orthopyroxenites. The pyroxene is enstatite. The peridotite part of the series is far better...KME 111 (Kimberley Mines, C.P.) and 370/3 (Jagersfontein, O.F.S.). Nodule XBULT20 (Bultfontein, C.P.) |  | | Journal (article/letter/editorial) | | series of high-pressure phase transformations: Enstatite (MgSiO3 pyroxene) or its high-pressure polymorphs...transformation reaction between pyrope (Mg3Al2Si3O12) and enstatite (MgSiO3) may be described as Eclogite 10 te...significant part of Cr may occur in the divalent state (Berry and O’Neill 2004). The potential presence...stabilize Cr3+ in our runs, we used the Re–ReO2 solid-state oxygen fugacity buffer in the high Cr experiments...ensure that most of the Cr is in the trivalent state (Li et al. 1995; Berry and O’Neill 2004). Additionally |  | | Journal (article/letter/editorial) | | southern Africa, Australia and North America. The sample set included locations such as Finsch (South Africa)...Africa), a mine which produces diamonds having fi~3C-values close to - 5%0, and Argyle (Australia), a mine...the Earth was composed of material akin to the enstatite chondrites (depleted in ~SN) and that a large...Finsch mine, South Afria Finsch mine, South Africa Finsch mine, South Africa Finsch mine, South Africa...Premier mine, South Africa Premier mine, South Africa Premier mine, South Africa Jagersfontein, South Africa |  | Kiseeva, Ekaterina S., Vasiukov, Denis M., Wood, Bernard J., McCammon, Catherine, Stachel, Thomas, Bykov, Maxim, Bykova, Elena, Chumakov, Aleksandr, Cerantola, Valerio, Harris, Jeff W., Dubrovinsky, Leonid (2018) Oxidized iron in garnets from the mantle transition zone. Nature Geoscience, 11 (2) 144-147 doi:10.1038/s41561-017-0055-7 | Journal (article/letter/editorial) | | Harris7 and Leonid Dubrovinsky3 The oxidation state of iron in Earth’s mantle is well known to depths...single-crystal X-ray diffraction to measure the oxidation state of Fe in inclusions of ultra-high pressure majoritic...garnets show a pronounced increase in oxidation state with depth, with Fe3+/(Fe3++ Fe2+) increasing from...metal. This implies that the increase in oxidation state is unconnected to disproportionation of Fe2+ to...was, therefore, to determine how the oxidation state of iron in garnet (included in diamond) from the |  | | Book | | relevant protective laws and regulations and therefore free for general use. 2132/3130-543210 To my wife,...collaboration. Much of my fieldwork in southern Africa has been carried out with the cooperation and assistance...7.3 2.8 2.9 Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . West Africa . . . . . . .... . . . . Central Africa. . . . . . . . . . . . . . . . . . . . . . . East Africa. . . . . . . . . .... . . . . . . . . . . . . . . . Southern Africa . . . . . . . . . . . . . . . . . . . . . U.S.S.R. . |  | | Journal (article/letter/editorial) | | and Department of Geological Sciences, Arizona State University, Tempe AZ 85287-1604, U.S.A. Department...Sciences, University of Cape Town, Rondebosch 7700, South Africa e-mail: David.R.Bell@asu.edu Rory O. Moore...Town, Rondebosch 7700, South Africa Email: © 2004 Geological Society of South Africa ABSTRACT Xenoliths...subcontinental lithospheric mantle of southern Africa, and may be used to probe its compositional structure...garnet megacrysts from 61 kimberlites in southern Africa define four broad arrays on the basis of Cr2O3 |
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