An investigation of the geochemistry of the Middle Group of the eastern Bushveld complex, South Africa Part 1 – the chromitite layers

References

• C. R. Anhaeusser: 'Ultramafic and mafic intrusions of the Kaapvaal craton', in 'Geology of South Africa', ( ed. M. R. Johnson et al), 95–134; 2006, Pretoria, Geological Society of South Africa, Johannesburg/Council for Geoscience.
   Google Scholar
• S.-J. Barnes and W. D. Maier: 'Platinum-group element distribu-tions in the Rustenburg Layered Suite of the Bushveld complex, South Africa', in 'The geology, geochemistry, mineralogy and mineral beneficiation of platinum-group elements', ( ed. L. J. Cabri), Special Volume 54, 431–458; 2002, Montreal, Canadian Institute of Mining, Metallurgy and Petroleum.
   Google Scholar
• P. B. Barton, Jr: Sulfide petrol.. Miner. Soc. Amer. Spec. Pap., 1970, 3, 187–98.
   Google Scholar
• R. G. Cawthorn: 'The platinum and palladium resources of the Bushveld Complex', S. Afr. J. ScL, 1999, 95, 481–489.
   Web of Science ®Google Scholar
• R. G. Cawthorn: 'Platinum-group element mineralization in the Bushveld Complex—a critical reassessment of geochemical mod-els', S. Afr. J. Geol., 1999, 102, 268–81.
   Web of Science ®Google Scholar
• R. G. Cawthorn and F. Walraven: 'Emplacement and crystal-lization time for the Bushveld Complex', J. Petrol., 1998, 39, 1669–1687.
   Web of Science ®Google Scholar
• R. G. Cawthorn, R. K. W. Merkle and M. J. Viljoen: 'Platinum-group element deposits in the Bushveld complex, South Africa', in 'The geology, geochemistry, mineralogy and mineral benefication of platinum-group elements', ( ed. L. J. Cabri), Special Volume 54, 389–429; 2002, Montreal, Canadian Institute of Mining, Metallurgy and Petroleum.
   Google Scholar
• R. G. Cawthorn, C. A. Lee, R. P. Schouwstra and P. Mellowship: 'Relationship between PGE and PGM in the Bushveld complex', Can Miner., 2002, 40, 311–328.
   Web of Science ®Google Scholar
• R. G. Cawthorn, H. V. Eales, F. Walraven, R. Uken and M. K. Watkeys: 'The Bushveld Complex', in 'Geology of South Africa', ( ed. M. R. Johnson et al), 261–281; 2006, Pretoria, Geological Society of South Africa, Johannesburg/Council for Geoscience.
   Google Scholar
• F. J. Coertze, A. J. Burger, F. Walraven, A. G. Marlow and D. R. Maccaskie: 'Field relations and age determinations in the Bushveld Complex', Trans. Geol. Soc. S. Afr., 1987, 81, (1), 1–11.
   Google Scholar
• S. A. S. Dare, J. A. Pearce, I. McDonald and M. T. Styles: 'Tectonic discrimination of peridotites using fO2—Cr# and Ga—Ti—FeIII systematic in chrome—spinel', Chem. Geol., 2009, 261, 199–216.
   Web of Science ®Google Scholar
• G. Davies and M. Tredoux: 'The platinum-group element and gold contents of the marginal rocks and sills of the Bushveld complex', Econ. Geol., 1985, 80, 838–848.
   Web of Science ®Google Scholar
• S. A. de Waal, W. D. Maier, R. A. Armstrong and C. D. K. Gauert: 'Parental magma and emplacement of the strati-form Uitkomst Complex, South Africa', Gait Miner., 2001, 2, 557–571.
   Google Scholar
• H. V. Eales: 'Implications of the chromium budget of the western limb of the Bushveld complex', S. Afr. J. Geol., 2000, 103, (2), 141–150.
   Web of Science ®Google Scholar
• H. V. Eales: 'A first introduction to the geology of the Bushveld Complex and those aspects of South African geology that relate to it', Popular Geoscience Series, Vol. 2, 84; 2001, Pretoria, The Council for Geoscience.
   Google Scholar
• H. V. Eales and R. G. Cawthorn: 'The Bushveld Complex', in 'Layered Intrusions', ( ed. R. G. Cawthorn), 181–230; 1996, Amsterdam, Elsevier.
   Google Scholar
• H.-F. Eckey, R. Kosfeld and M. Tarck: 'Deskriptive Statistik: Grundlagen — Methoden — Beispiele', 5th, revised edn, 283; 2008, Wiesbaden, Gabler.
   Google Scholar
• S. B. Gain: 'The geological setting of the platiniferous UG-2 chromitite layer on the farm Maandagshoek, eastern Bushveld complex', Econ. Geol., 1985, 80, 925–943.
   Web of Science ®Google Scholar
• D. Gould, P. A. Rathbone, G. S. Kimbell, A. J. Burley, R. J. Peart, M. E. Parker and S. F. Pease: 'The geology of the Molopo Farms Complex, southern Botswana', Bull. Geol. Surv. Botswana, 1987, 21, 178.
   Google Scholar
• R. E. Harmer and M. R. Sharpe: 'Field relations and strontium isotope systematic of the marginal rocks of the eastern Bushveld complex', Research Report 50, Inst. Geol. Res. Univ., Pretoria, South Africa, 1984.
   Google Scholar
• C. J. Hatton and J. K. Schweitzer: 'Evidence for synchronous extrusive and intrusive Bushveld magmatism', J. S. Afr. Earth Set, 1995, 21, 579–594.
   Web of Science ®Google Scholar
• R. Hill and P. Roeder: 'The crystallization of spinel from basaltic liquid as a function of oxygen fugacity', J. Geol., 1974, 82, 709–729.
   Web of Science ®Google Scholar
• L. J. Hulbert and G. von Gruenewaldt: 'Textural and composi-tional features of chromite in the lower and Critical Zones of the Bushveld Complex South of Potgietersrus', Econ. Geol., 1985, 80, 872–895.
   Web of Science ®Google Scholar
• T. N. Irvine: 'Crystallization sequences in the Muskox intrusion and other layered intrusions-II. Origin of chromitite layers and similar deposits of other magmatic ores', Geochim. cosmochim. Acta, 1975, 39, 991–1020.
   Web of Science ®Google Scholar
• J. A. Kinnaird, F. J. Kruger, P. A. M. Nex and R. G. Cawthorn: 'Chromitite formation—a key to understanding processes of platinum enrichment', Trans. Inst. Min. Metall (Sect. B: AppL Earthsci.), 2002, 111, B23—B35.
   Web of Science ®Google Scholar
• J. Kottke-Levin, M. Tredoux and P.-J. Grabe: 'An investigation of the geochemistry of the Middle Group of the eastern Bushveld complex, South Africa. Part II: the silicate cumulates', in prep.
   Google Scholar
• F. J. Kruger: 'Filling the Bushveld complex magma chamber: lateral expansion, roof and floor interaction, magmatic unconfor-mities, and the formation of giant chromitite, PGE and Ti-V-magnetite deposits', Miner. Depos., 2005, 40, 451–472.
   Web of Science ®Google Scholar
• C. A. Lee and S. J. Parry: 'Platinum-group element geochemistry of the Lower and Middle Group chromitites of the Eastern Bushveld Complex', Econ. Geol., 1988, 83, 1127–1139.
   Web of Science ®Google Scholar
• K. Lodders: 'Solar system abundances and condensation tempera-tures of the elements', Astrophys. J., 2003, 591, 1220–1247.
   Web of Science ®Google Scholar
• W. D. Maier and S.-J. Barnes: 'Concentrations of rare earth elements in silicate rocks of the Lower, Critical and Main Zones of the Bushveld Complex', Chem. Geol., 1998, 150, 85–103.
   Web of Science ®Google Scholar
• R. K. W. Merkle: 'Platinum-group minerals in the middle group of chromitite layers at Marikana, western Bushveld Complex: indications for collection mechanism and postmagmatic modifica-tion', Can. J. Earth Sci, 1992, 29, 209–221.
   Web of Science ®Google Scholar
• S. K. Mondal and E. A. Mathez: 'Origin of the UG2 chromitite layer, Bushveld Complex', J. Petrol, 2007, 48, (3), 495–510.
   Web of Science ®Google Scholar
• B. W. and I. H. Campbell: 'The effects of temperature, oxygen fugacity and melt composition on the behaviour of chromium in basic and ultrabasic melts', Geochim. Cosmochim. Acta, 1986, 50, 1871–1887.
   Web of Science ®Google Scholar
• A. J. Naldrett and J. Lehmann: 'Spinel non-stoichiometry as the explanation for Ni-, Cu- and PGE-enriched sulphides in chromitites', in 'Geo-platinum '87', ( ed. H. M. Prichard et al.); 1987, London, Elsevier Science publishing Ltd.
   Google Scholar
• A. J. Naldrett and G. von Gruenewaldt: 'Association of platinum-group elements with chromite in layered intrusions and ophiolite complexes', Econ. Geol., 1989, 84, 180–187.
   Web of Science ®Google Scholar
• A. J. Naldrett, A. Wilson, J. Kinnaird and G. Chunnett: 'PGE tenor and metal ratios within and below the Merensky Reef, Bushveld Complex: implications for its genesis', J. PetroL, 2009, 50, (4), 625–659.
   Web of Science ®Google Scholar
• A. D. Pactunk and L. J. Cabri: 'A proton- and electron-microprobe study of gallium, nickel and zinc distribution in chromian spinel', Lithos, 1995, 35, 261–282.
   Web of Science ®Google Scholar
• A. Rice and G. von Gruenewaldt: 'Shear aggregation (convective scavenging) and cascade enrichment of PGEs and chromite', Miner. Petrol, 1995, 54, 105–117.
   Web of Science ®Google Scholar
• L. W. Schürmann, P.-J. Gräbe and C. J. Steenkamp: 'Chromium', in 'The mineral resources of South Africa, Handbook 16', ( ed. M. G. C. Wilson and C. R. Anhaeusser); 90–105; 1998, Pretoria, Council for Geoscience.
   Google Scholar
• R. N. Scoon and B. Teigler: 'Platinum-group element mineraliza-tion in the critical zone of the western Bushveld Complex; I, Sulfide poor-chromitites below the UG2', Econ. Geol., 1994, 89, 1094.–1121.
   Web of Science ®Google Scholar
• R. N. Scoon and W. J. de Klerk: 'The relationship of olivine cumulates and mineralization to cyclic units in part of the upper Critical Zone of the western Bushveld complex', Can. Miner., 1987, 25, 51–77.
   Web of Science ®Google Scholar
• R. Schoenberg, F. J. Kruger, T. F. Nagler, T. Meisel and J. D. Kramers: 'PGE enrichment in chromitite layers and the Merensky Reef of the western Bushveld Complex; a Re—Os and Rb—Sr isotope study', Earth Planet. Sci. Lett., 1999, 172, 49–64.
   Web of Science ®Google Scholar
• M. R. Sharpe: 'Noble Metals in the Marginal Rocks of the Bushveld Complex', Econ. Geol., 1982, 77, 1286–1295.
   Web of Science ®Google Scholar
• C. Spandler, J. Mavrogenes and R. Arculus: 'Origin of chromi-tites in layered intrusions: evidence from chromite-hosted melt inclusions from the Stillwater Complex', Geology, 2005, 33, 893–896.
   Web of Science ®Google Scholar
• C. Spandler, H. St. C. O'Neill and V. S. Kamenetsy: 'Survival times of anomalous melt inclusions from element diffusion in olivine and chromite', Nature, 2007, 447, 303–306.
   Web of Science ®Google Scholar
• M. R. Sharpe and L. J. Hulbert: 'Ultramafic sills beneath the eastern Bushveld complex: mobilized suspensions of early Lower Zone cumulates in a parental magma with boninitic affinities', Econ. Geol., 1985, 80, 849–871.
   Web of Science ®Google Scholar
• H.-G. Stosch: 'Geochemie der Seltenen Erden', Lecture script of the Department of Mineralogy and Petrology at the University of Cologne, Germany, Version 3.1, 2008, 209.
   Google Scholar
• B. Teigler: 'Platinum-group element distribution in the lower and middle group chromitites in the western Bushveld Complex', Miner. Petrol, 1990, 42, 165–179.
   Web of Science ®Google Scholar
• B. Teigler and H. V. Eales: 'Correlation between chromite composition and PGE mineralization in the Critical Zone of the western Bushveld Complex', Miner. Depos., 1993, 28, 291–302.
   Web of Science ®Google Scholar
• M. Tredoux, N. M. Lindsay, G. Davies and I. McDonald: 'The fractionation of platinum-group elements in magmatic systems, with the suggestion of a novel causal mechanism', S. Aft J. Geol., 1995, 98, 157–167.
   Google Scholar
• G. von Gruenewaldt, C. J. Hatton, R. K. W. Merkle and S. B. Gain: 'Platinum-group element — chromitite associations in the Bushveld Complex', Econ. Geol., 1986, 81, 1067–1079.
   Web of Science ®Google Scholar
• F. L. Walraven: 'Notes on the age and genetic relationships of the Makhutso Granite, Bushveld Complex, South Africa', Chem. Geol., 1988, 72, 17–28.
   Web of Science ®Google Scholar
• F. Walraven, E. A. Retief, A. J. Burger, D. J. V. de Swanepoel: 'Implications of new U-Pb zircon age dating on the Nebo Granite of the Bushveld Complex', S. Afr. J. Geol., 1987, 90, 344–351.
   Google Scholar
• F. Walraven, R. A. Armstrong and F. J. Kruger: 'A chromostrati-graphic framework for the north-central Kaapvaal craton, the Bushveld complex and Vredefort structure', Tectonophysics, 1990, 171, 23–48.
   Web of Science ®Google Scholar
• F. Walraven and E. Hattingh: 'Geochronology of the Nebo Granite, Bushveld Complex', S. Afr. J. Geol., 1993, 96, 31–41.
   Google Scholar
• J. A. White: 'The Potgietersrus project: geology and exploration history', Proc. 15th CMMI Cong., Johannesburg, South Africa, 1994, S.Afr. Inst. Min. Metall., 173–182.
   Google Scholar