 | | Journal (article/letter/editorial) | | Ni–Cu–PGE POTENTIAL OF THE INSIZWA LOBE, MOUNT AYLIFF INTRUSION, SOUTH AFRICA R. GRANT CAWTHORN§ AND F...Wits, 2050, South Africa ABSTRACT The Insizwa lobe of the Mount Ayliff Intrusion, South Africa, is part...drilling of a borehole into the center of the Insizwa lobe that revealed an abnormally thick ultramafic...indicating prior separation of sulfide. Keywords: Insizwa, Mount Ayliff Intrusion, Karoo magmatism, multiple...magnesian magma, Ni depletion, Sr isotopes, South Africa. SOMMAIRE Le lobe d’Insizwa de la masse intrusive |  | | Journal (article/letter/editorial) | | The Geologyand Geochemistryof the Waterfall Gorge Section of the Insizwa Complex with ParticularReferenceto...Jurassic-aged mafic rocksfrom the Waterfall Gorge sectionof the Insizwa layered complex,Transkei, range...compositional data for the mineral phases(olivine, plagioclase,bronzite, and augite) show significant features:in...responsiblefor the compositionalvariationin this unit at Insizwa, however, to accountfor the upward increasein the...the productionof the basalgabbro. Introduction Gorge,the sequenceof intrusiverocksand contact THE Karoo-agedInsizwa |  | | Journal (article/letter/editorial) | | FENNER 409 The geochemical structure of the Insizwa lobe of the Mount Ayliff complex with implications...Geology, Rhodes University, Grahamstown 6140, South Africa e-mail: goonie.marsh@ru.ac.za P. Allen Department...University of Fort Hare, Alice, South Africa N. Fenner Falconbridge Ventures of Africa, PO Box 12708, Hatfield...Hatfield, Pretoria 0028, South Africa © 2003 Geological Society of South Africa ABSTRACT Detailed petrographic...instances) along the southeastern margin of the Insizwa lobe of the Mount Ayliff Complex reveal the existence |  | | Journal (article/letter/editorial) | | University of the Witwatersrand, P.O. Wits 2050, South Africa Cnnrstopnrn J. HlrroN* Institute for Geological...University of Pretoria, Hillcrest, Pretoria 0002, South Africa Kpvrx F. Cassrnv Key Centre for Teaching and...Intrusion from the Karoo Igneous Province of South Africa have been studied. Many analysesof chromite...mixing. Data from a restricted interval of the Waterfall Gorge profile at the base of the picrite indicate...ResearchIaboratories, Box 106. Crown Mines 2025. South Africa. 0003-004X/9I /03021-056 I $02.00 An extensive |  | Groves, David I., Marchant, Trudi, Maske, S., Cawthorn, R. Grant (1986) Compositions of ilmenites in Fe-Ni-Cu sulfides and host rocks, Insizwa, southern Africa; proof of coexisting immiscible sulfide and silicate liquids. Economic Geology, 81 (3) 725-731 doi:10.2113/gsecongeo.81.3.725 | Journal (article/letter/editorial) | | IN Fe-Ni-Cu SULFIDES AND HOST ROCKS, INSIZWA, SOUTHERN AFRICA: PROOF OF COEXISTING IMMISCIBLE SULFIDE...which can be usedto indicatea magmaticorigin. the Insizwa complexin southernAfrica. Here, coexThesefeaturesinclude:(1)...platinum-group elements)andthose Geologyof the Insizwa Fe-Ni-Cu Sulfide Deposits predictedon the basisof...sulfide depositsof the Waterfall mentaldata,and (4) chalcophileelementdepletion Gorge sectionof the Insizwaintrusionand...mined camefromthe WaterfallGorgesectionof the Insizwa * Presentaddress:GoldfieldsExplorationPty. Ltd |  | | Journal (article/letter/editorial) | | shift effect in the Mount Ayliff Intrusion, South Africa R. Grant Cawthorn, Bernhard K. Sander and Ian...the Witwatersrand, Private Bag 3, Wits 2050, South Africa Received July 15, 1991/AcceptedJanuary 4, 1992...liquid shift. He specifically referred to the Insizwa lobe of the Mount Ayliff Intrusion and suggested...olivine gabbronorite, reaching 15 m thick at Waterfall Gorge (Lightfoot et al. 1984), but at Mount Evelyn...(Fig. 4) and chromite, with abundant subhedral plagioclase and anhedral pyroxenes. Geochemistry We have |  | | Journal (article/letter/editorial) | | formations. CONTENTS TEXT Introduction Acknowledgments Insizwa intrusion Bushveld complex Kungwe Bay lopolith...Field studies of the Insizwa intrusion and the Bushveld complex in South Africa, the Great Dyke in Southern...many lopoliths such ILLUSTRATIONS Figure Page 1. Insizwa intrusion 290 2. Bushveld igneous complex 291 3...Levack to Gertrude... 297 as the Bushveld and Insizwa intrusions is parallel to the bedding of the country...eorsion. INSIZWA INTRUSION BUSHVELD COMPLEX Along the southeast and eastern edge of the Insizwa intrusion |  | | Journal (article/letter/editorial) | | Geology, Rhodes University, Grahamstown 6140 (South Africa) (Received October 16, 1979; accepted for publication...Both major- and trace-element data for the large Insizwa layered complex indicate retention of 20% parental...interstitial liquid by heteradcumulus growth of plagioclase in adjacent layers is responsible for this anomalous...interstitial p h a s e ( p y r o x e n e or plagioclase) as well as t h e p r i m o c r y s t s c o n...self-consistent for several elements. In the case of the Insizwa intrusion, the data further identify a class of |  | Barnes, Stephen J., Mungall, James E., Le Vaillant, Margaux, Godel, Belinda, Lesher, C. Michael, Holwell, David, Lightfoot, Peter C., Krivolutskaya, Nadya, Wei, Bo (2017) Sulfide-silicate textures in magmatic Ni-Cu-PGE sulfide ore deposits: Disseminated and net-textured ores. American Mineralogist, 102 (3) 473-506 doi:10.2138/am-2017-5754 | Journal (article/letter/editorial) | | distribution of S abundance in ores from the Ovoid and Eastern Deeps at Voisey’s Bay, after Lightfoot et al. (2012)...deflected close to the contact line to achieve local textural equilibrium. (c) Axial cross section of...instrumental noise from the image (generally a non-local mean filter was applied), and a 3D gradient watershed...north-eastern Brazil (Barnes et al. 2011c), the Merensky Reef of the Bushveld Complex in South Africa...(black) intergrown with intercumulus patch of plagioclase, amphibole, mica, and apatite. (d and e) Perspective |  | | Journal (article/letter/editorial) | | APRIL 1949 KARROO DOLERITES OF THE UNION OF SOUTH AFRICA BY FREDERICK WALKER AND ARIE POLDERVAART CONTENTS...Karroo dolerites 685 Outlying areas in Southern Africa 687 Trias-Lias vulcanicity in Gondwanaland 687...System in the Union of South Africa 597 2. Distribution of Karroo System in Africa 600 3. Map and section...Grey sheet, Queenstown 605 5. Map and section of Insizwa sheet, Mount Ayliff 606 6. Map and section of Elephant's...of Mount Arthur (Kokstad) 621 15. Hornfelses of Insizwa (Mount Ayliff) 626 16. Assimilation product at |  | | Journal (article/letter/editorial) | | at Carolusberg and East Okiep, Namaqualand, South Africa Received: 12 April 1999 / Accepted: 27 November... due to the paucity of refractory ores in the district. Assimilation of Cu-rich country rocks during...The Cu-sulphide ores of the Okiep district of Namaqualand, South Africa (Fig. 1), remain one of the more...more enigmatic mineral deposits in southern Africa. The ores are hosted by the pyroxenitic and, to a lesser...Sciences, University of Pretoria, Pretoria 0002, South Africa e-mail: wdmaier@scientia.up.ac.za et al. 1983; |  | | Journal (article/letter/editorial) | | Geology, University of Pretoria, 0002 Pretoria, South Africa E-mail: wdmaier@scientia.up.ac.za S.-J. Barnes...Geology, Rhodes University, 6140, Grahamstown, South Africa Editorial responsibility: I. Parsons MORB appear...(Barnes and Francis 1995), the Chukotat basalts of the Cape Smith Fold Belt (Barnes and Picard 1993), and the...segregation during ascent. 45 Fig. 1 Map of southern Africa, showing distribution of analysed suites. Insert...Group is sporadic in the Northwest Province of South Africa (Fig. 1), but drilling has established more |  | | Journal (article/letter/editorial) | | liquid in orthocumulares. The calculation assumes local equilibrium between phases, and that the system...in compatible elements such as Ni and Cr, and plagioclase will become more sodic. The higher the initial...ratio 1 : 1. The ratio of marie minerals to plagioclase crystallizing from the trapped liquid is calculated...olivine cumulates show the smallest shifts and plagioclase - orthopyroxene - clinopyroxene cumulates the...bronzite plus plagioclase at 20% fractionated, and from opx+plagioclase to opx + cpx + plagioclase at 40%. |  | | Journal (article/letter/editorial) | | Glenmacnass, Co. Wicklow, sillimanite, 763 Rosses district, Donegal, beryl, 328 Three Rock Mtn, San@ford...yttrotungstite, raspite, stolzite, 261 Bau mining district, Sarawak, antimonian idoerase, 894 Tapah, Kinta...India Bhopal, levyne, 527 Ghoriajor, Sundargarh District, Orissa, blanfordite, 3z Jothvad, Gujarat, blandfordite...blandfordite, 32 Kacharwali, Nagpur District, Maharashtra, blanfordite, 32 Khetri copper belt, Rajasthan...hornblende, cummingtonite, 89o Mamandur, South Arcot District, Madras, ferroan gahnite, 528 Maruturu Anakapatle |  | | Journal (article/letter/editorial) | | General Account of Karoo Vulcanicity in Southern Africa By J. w . BaisTow, New Mexico, and E. P. SAGGERSON...three main areas of southern Africa, in Namibia, in central South Africa, Transkei and Lesotho and in...southeastern areas of the sub-continent including South Africa, Swaziland, Mozambique and Zimbabwe. A history...of Geology, University of Natal, Durban 4001, South Africa. 65 GeologischeRundschau, 72, 3, 1015--1060...composition whereas those from the western and eastern marginal areas include basic, and felsic types |  | | Journal (article/letter/editorial) | | association, notably the Insizwa and related intrusions from the Karoo province of South Africa. In addition, the...Chibacheka River intrusion, south-southeast of the town of Noril’sk on the eastern margin of the flood basalt...subpoikilitic clinopyroxene enclosing euhedral plagioclase laths and weakly resorbed rounded olivine grains...boundaries between any combination of olivine, plagioclase, sulfide, or pyroxene. Lower Talnakh intrusion...G22 68.0, top of picritic gabbro. Olivine and plagioclase in poikilitic clinopyroxene, with Cr spinel clusters |  | | Journal (article/letter/editorial) | | 1986), O'Toole, Brazil (Marehetto, 1990), Waterfall Gorge, Pondoland (Tischler et al., 1981), Ivrea-Verbano...striking northeast and plunging steeply to the south. Mine workings include the T-1 and T-3 underground...whereas the T-3 mine and the open pit are on the eastern limb (Fig. 2). The locus of the Ni sulphide ore...of about 5 kin, with local concentrations along the southern portion of the eastern limb of the fold, around...pyrrhotite with minor chalcopyrite and pyrite. Local Lithologies. Lithologies defining the fold structures |  | | Journal (article/letter/editorial) | | Noril'sk-Talnakharea, the Duluth Complex,the InsizwaComplex,andthe Cape Smithbelt. Someof the marginalsulfidesat Muskoxare...RegionalGeologicSetting The country rocks to the south, east, and west of the Muskox intrusion are paragneissesand...suggested that the rifting event and the openingof Local Geology the oceanwere associatedwith a mantle plume...by 11 km wide in the north by 100 m wide in the south andpossiblybefore mostof the CoppermineRiver flood...(Hornal, 1968). Thus, the surfaceexposurerepreMa Cape Smith deposits(Franciset al., 1983; Barneset sentsa |  | | Journal (article/letter/editorial) | | VANCE (E. R.), 605, manganese ores, 235 Bau mining district, Sarawak, Malaysia, anti721 monian idocrase, 894...Iceland, anal., 5o3 Anorthosite, Labrador, dense plagioclase glass in, Bertaghboy Bay, Canover, Connemara...FERNANDEZ(L. A.), Phenocrystic olivines from the eastern Azores, 165 Boulangerite, Cornwall, 767 BOUVIER(J...), An antimonian idocrase from the Bau mining district, Sarawak, 894 BRICE (W. R.), see CHANG (L. L....struvite from Skipton, Victoria, 381 Broken Hill, New South Wales, muscovite, myrmekite, 57o Bronzite, Sitathali |  | | Book | | 1. Mafic dyke swarms in the Kaapvaal Craton, South Africa 189 3.4.2. The Mackenzie dyke swarm, Canada...controls of intracontinental alkaline magmatism in Africa 194 3.5.2. The Damaraland alkaline province, Namibia...Namibia 6.3.2. Anorogenic metamorphism in the eastern Pyrenees 6.3.3. Anorogenic metamorphism and intraplate...intraplate magmatism around the Vredefort Dome, South Africa 6.3.4. Metamorphism and fluid generation; metamorphogenic...Bushveld lgneous Complex, South Africa 8.2.3. Molopo Farms Complex, South Africa and Botswana 8.3 Magmatic |  | | Journal (article/letter/editorial) | | show geopetal indicators. Sulphur isotopes imply a local crustal source of S in these from pyritic sediments...of these sulphide occurrences was controlled by local country rock type. Low Ni/Cu and Pt/Pd ratios, also...abundant pyrite as large cubic crystals. Further south, in the Eskimonaes Segment, the Miki Fjord Macrodyke...medium-coarse-grained olivine, clinopyroxene, orthopyroxene, plagioclase and minor magnetite and biotite. Goodwin and...xenoliths in the area around the ‘Saddle’ on the eastern side of the dyke (Fig. 3b), as described in the |  | Karykowski, Bartosz T., Maier, Wolfgang D., Groshev, Nikolay Y., Barnes, Sarah-Jane, Pripachkin, Pavel V., McDonald, Iain, Savard, Dany (2018) Critical Controls on the Formation of Contact-Style PGE-Ni-Cu Mineralization: Evidence from the Paleoproterozoic Monchegorsk Complex, Kola Region, Russia. Economic Geology, 113 (4) 911-935 doi:10.5382/econgeo.2018.4576 | Journal (article/letter/editorial) | | to the local addition of water and, potentially, carbon dioxide to the magma, resulting in local small-scale...sulfide liquid accumulation at the base, while the local decrease in magma viscosity facilitated gravitational...intrusions, such as in the Bushveld Complex (South Africa), the Great Dyke (Zimbabwe), and the Stillwater...Monchegorsk Complex. It is located approximately 120 km south of Murmansk on the Kola Peninsula of Russia and...Mineral compositions of olivine, pyroxene, and plagioclase were determined, using a Zeiss Sigma HD analytical |  | | Book | | Bushveld chromite–platinum group metals (PGMs), South Africa, Sudbury nickel–copper, Canada, and a few new...occurrences/deposits/mines of six continents: Africa, North America, South America, Asia, Oceania (including Australia)...Earth’s element family. The working deposits in South Africa and Russia are by far the largest for the PGM...significant in Canada, United States, Australia, Africa, Brazil, New Caledonia, Philippines, Indonesia...Caribbean. The largest chromite deposits are in South Africa, Zimbabwe, Kazakhstan, Turkey, Finland, and |  | | Book (edition) | | OF OF SOUTH AFRICA MINES GEOLOGICAL SURVEY MINERAL RESOURCES OF REPUBLIC OF THE SOUTH AFRICA...Second World War, and partly as a result of it, South Africa experienced vast industrial expansion. This...official ‘handbook on the mineral resources of South Africa, it has become necessary to revise, or rather...great diversity and magnitude of South African mineral deposits and local mining operations, the Economic...Chamber of Mines of South Africa with Mr G. H. Grange as co-ordinator, and the South, African mining industry; |  | Seat, Z., Mary Gee, M. A., Grguric, B. A., Beresford, S. W., Grassineau, N. V. (2011) The Nebo-Babel Ni-Cu-PGE Sulfide Deposit (West Musgrave, Australia): Pt. 1. U/Pb Zircon Ages, Whole-Rock and Mineral Chemistry, and O-Sr-Nd Isotope Compositions of the Intrusion, with Constraints on Petrogenesis. Economic Geology, 106 (4) 527-556 doi:10.2113/econgeo.106.4.527 | Journal (article/letter/editorial) | | NORTHERN TERRITORY Amadeus Basin WOOD ROFFE THRUS T SOUTH AUSTRALIA MAN N WESTERN AUSTRALIA FAULT 27°S...metamorphic rocks Wingellina NORTHERN TERRITORY Hills SOUTH AUSTRALIA TO na ve Ca M gh e ng Ra Tollu Mum...orthogneiss country rock consists of K-feldspar, plagioclase, and quartz with less than 10 to 15 vol percent...reduction, incipient to weak saussuritization of plagioclase, and uralitization of pyroxene. 1120 Pitjantjatjara...10° plunge toward southwest and a 15° dip to the south. In general, deformation is confined to shear zones |
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