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Geochemistry and mineralogy of platinum-group elements at Hartley Platinum Mine, Zimbabwe

Part 1. Primary distribution patterns in pristine ores of the Main Sulfide Zone of the Great Dyke

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Abstract

The Main Sulfide Zone (MSZ) is the most prominent layer of the Great Dyke layered intrusion carrying economic platinum-group element (PGE) mineralization. At the Hartley Platinum Mine, the MSZ is up to some meters thick and is composed of a basal PGE-rich subzone which overlaps slightly with a base metal, sulfide-rich subzone on top. Based on the degree of sulfide mineralization and PGE ratios, the subzones can be further divided into geochemically distinct layers. Stratigraphically upwards, the MSZ displays metal profiles characterized by increasing Cu/Ni, Pt/Pd and PPGE/IPGE ratios, accompanied by a general element decoupling in the order Pd→Pt→base metals, more specifically IPGE→Pd→Pt→(Ni,Cu,Co,S(sulfides),Au,Te,Bi. The fine structure of the MSZ is regarded to reflect primary magmatic features of consecutive batches of sulfide accumulation, concomitant scavenging of PGE, and fractionation. Sulfide deposition was followed by a second, limited subsolidus stage of PGE redistribution. Mineralogically, most of the Pd and Rh is hosted in pentlandite, whereas Pt is dominantly present in the form of discrete platinum-group minerals (PGM). Within the MSZ sequence, sperrylite is present throughout the PGE subzone of the MSZ, cooperite/braggite occur mainly in its basal part, and the (Pt,Pd)-bismuthotellurides concentrate at the top. These findings indicate that a large proportion of the PGE, primarily concentrated in sulfide under magmatic conditions, was redistributed in the subsolidus stage and formed discrete PGM with available reactant partners. Chemical gradients and magmatic–hydrothermal fluids probably led to small-scale redistribution of PGE within the MSZ.

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References

  • Ballhaus CG, Ryan CG (1995) Platinum-group elements in the Merensky reef. I. PGE in solid solution in base metal sulfides and the down-temperature equilibration history of Merensky ores. Contrib Mineral Petrol 122:241–251

    Article  CAS  Google Scholar 

  • Ballhaus CG, Stumpfl EF (1986) Sulphide and platinum mineralisation in the Merensky Reef: evidence from hydrous silicates and fluid inclusions Contrib Mineral Petrol 94:193–204

    CAS  Google Scholar 

  • Barnes SJ (1993) Partitioning of the platinum group elements and gold between silicate and sulfide magmas in the Munni Munni Complex, Western Australia. Geochim Cosmochim Acta 57:1277–1290

    CAS  Google Scholar 

  • Boudreau AE, Meurer WP (1999) Chromatographic separation of the platinum-group elements, gold, base metals and sulfur during degassing of a compacting and solidifying igneous crystal pile. Contrib Mineral Petrol 134:174–185

    CAS  Google Scholar 

  • Brown RT (1998a) Hartley Platinum Mine geology and grade control. In: Prendergast MD (compiler) 8th Int Platinum Symp, 23–28 June 1998, Rustenburg, South Africa. Guideb Excursion Great Dyke of Zimbabwe, pp 16–18

  • Brown RT (1998b) An overview of the geology and mining at BHP Hartley Platinum Mine, Great Dyke, Zimbabwe. BHP Hartley Platinum Mine Visitors Guide, pp 1–34

  • Cabri LJ, McMahon G (1995) SIMS analysis of sulfide minerals for Pt and Au: methodology and relative sensitivity factors (RSF). Can Mineral 33:349–359

    CAS  Google Scholar 

  • Campbell ICH, Barnes SJ (1984) A model for the geochemistry of the platinum-group elements in magmatic sulphide deposits. Can Mineral 22:151–160

    CAS  Google Scholar 

  • Campbell ICH, Naldrett AJ (1979) The influence of silicate:sulfide ratios on the geochemistry of magmatic sulfides. Econ Geol 74:1503–1505

    CAS  Google Scholar 

  • Campbell ICH, Naldrett AJ, Barnes SJ (1983) A model for the origin of the platinum-rich sulfide horizons in the Bushveld and Stillwater complexes. J Petrol 24:133–165

    CAS  Google Scholar 

  • Coghill BM, Wilson AH (1993) Platinum-group minerals in the Selukwe subchamber, Great Dyke, Zimbabwe: implications for PGE collection mechanisms and post-formational redistribution. Mineral Mag 57:613–633

    CAS  Google Scholar 

  • Czamanske GK, Kunilov VE, Zientek ML, Cabri LJ, Likhachev AP, Calk LC, Oscarson RI (1992) A proton-microprobe study of sulfide ores from the Noril'sk-Talnakh district, Siberia. Can Mineral 30:249–288

    CAS  Google Scholar 

  • Evans DM, Buchanan DL (1991) Application of petrographic studies to MSZ platinum-group element and base-metal mineralization at Zinca prospect, Great Dyke, Zimbabwe. Trans Inst Mining Metall 100:B216–B226

    Google Scholar 

  • Evans DM, Buchanan DL, Hall GEM (1994) Dispersion of platinum, palladium and gold from the Main Sulphide Zone, Great Dyke, Zimbabwe. Trans Inst Mining Metall 103:B57–B67

    CAS  Google Scholar 

  • Germann K, Schmidt F (1999) Platinum-group element concentrations in chromitites of the Great Dyke, Zimbabwe. Bundesanstalt Geowissen Rohstoffe (BGR), Ber Lagerstätten Rohstoffforschung 34

  • Harney DMW, Merkle RKW (1990) Pt–Pd minerals from the Upper Zone of the eastern Bushveld Complex, South Africa. Can Mineral 28:619–628

    Google Scholar 

  • Hoffman E, MacLean WH (1976) Phase relations of michenerite and merenskyite in the Pd–Bi–Te system. Econ Geol 71:1461–1468

    CAS  Google Scholar 

  • Johan Z, Ohnenstetter D, Naldrett AJ (1989) Platinum-group minerals and associated oxides and base metal sulphides of the Main Sulphide Zone, Great Dyke, Zimbabwe. In: Papunen H (ed) Proc 5th Int Platinum Symp. Bull Geol Soc Finland 61(1):53–54

    Google Scholar 

  • Makovicky M, Makovicky E, Rose-Hansen J (1992) The phase system Pt–Fe–As–S at 850 °C and 470 °C. N Jb Mineral Mh 1992/10:441–453

    Google Scholar 

  • Mathez EA (1999) On factors controlling the concentrations of platinum group elements in layered intrusions and chromitites. In: Keays RR, Lesher CM, Lightfoot PC, Farrow CEG (eds) Dynamic processes in magmatic ore deposits and their application in mineral exploration. Geol Assoc Can Short Course 13:251–285

    Google Scholar 

  • Naldrett AJ (1993) Models for the formation of strata-bound concentrations of platinum-group elements in layered intrusions. In: Kirkham RV, Sinclair WD, Thorpe RI, Duke JM (eds) Mineral deposit modeling. Geol Ass Can Spec Pap 40:373–387

    CAS  Google Scholar 

  • Naldrett AJ, Wilson AH (1990) Horizontal and vertical variations in noble metals in the Great Dyke of Zimbabwe: a model for the origin of PGE mineralization by fractional seggregation. Chem Geol 88:279–300

    CAS  Google Scholar 

  • Naldrett AJ, Brügmann GE, Wilson AH (1990) Models for the concentration of PGE in layered intrusions. Can Mineral 28:389–408

    CAS  Google Scholar 

  • Oberthür T (2002) Platinum-group element mineralization of the Great Dyke, Zimbabwe. In: Cabri LJ (ed) The geology, geochemistry, mineralogy and mineral benefication of platinum-group elements. Can Inst Mining Metall Petrol Spec Vol 54:483–506

    Google Scholar 

  • Oberthür T, Cabri LJ, Weiser Th, McMahon G, Müller P (1997) Pt, Pd and other trace elements in sulfides of the Main Sulfide Zone, Great Dyke, Zimbabwe—a reconnaissance study. Can Mineral 35:597–609

    Google Scholar 

  • Oberthür T, Weiser Th, Müller P, Lodziak J, Cabri LJ (1998a) New observations on the distribution of platinum group elements (PGE) and minerals (PGM) in the MSZ at Hartley Mine, Great Dyke, Zimbabwe. In: Proc 8th Int Platinum Symp. S Afr Inst Mining Metall Symp Ser S18:293–296

    Google Scholar 

  • Oberthür T, Weiser TW, Gast L, Lodziak Je, Klosa D, Wittich C (1998b) Detrital platinum group minerals in rivers along the Great Dyke, and in the Somabula gravels, Zimbabwe. In: Proc 8th Int Platinum Symp. S Afr Inst Mining Metall Symp Ser S18:289–292

    Google Scholar 

  • Oberthür T, Weiser ThW, Gast L (1999) Mobility of PGE and PGM in the supergene environment at Hartley Mine, Great Dyke, Zimbabwe—a case study. In: Stanley CJ et al. (eds) Mineral deposits: processes to processing. Balkema, Rotterdam, pp 763–766

    Google Scholar 

  • Oberthür T, Weiser ThW, Gast L, Wittich C, Kojonen K (2000) Mineralogy applied to the evaluation and processing of platinum ores of the Main Sulfide Zone, Great Dyke, Zimbabwe. In: Rammlmair D, Mederer J, Oberthür T, Heimann RB, Pentinghaus H (eds) Applied mineralogy. Balkema, Rotterdam, pp 379–382

  • Oberthür T, Davis DW, Blenkinsop TG., Höhndorf A (2002) Precise U–Pb mineral ages, Rb–Sr and Sm–Nd systematics for the Great Dyke, Zimbabwe—constraints on late Archean events in the Zimbabwe Craton and Limpopo Belt. Precambrian Res 113:293–305

    Article  Google Scholar 

  • Peach CL, Mathez EA (1996) Constraints on the formation of platinum-group element deposits in igneous rocks. Econ Geol 91:439–450

    CAS  Google Scholar 

  • Prendergast MD (1988a) An investigation of the stratigraphy and petrology of the Pyroxenite No. 1 layer of the Great Dyke, Zimbabwe, with special reference to the characteristic features and origin of the platinum-group element-bearing Main Sulfide Zone. PhD Thesis, University of Zimbabwe

  • Prendergast MD (1988b) The geology and economic potential of the PGE-rich Main Sulfide Zone of the Great Dyke, Zimbabwe. In: Prichard HM, Potts PJ, Bowles JFW, Cribb SJ (eds) Proc Symp Geo-Platinum 87, 22–23 April 1987, Milton Keynes. Elsevier, London, pp 281–302

  • Prendergast MD (1990) Platinum-group minerals and hydrosilicate 'alteration' in the Wedza–Mimosa Platinum Deposit, Great Dyke, Zimbabwe—genetic and metallurgical implications. Trans Inst Mining Metall Sect B Appl Earth Sci 99:B91–B105

    CAS  Google Scholar 

  • Prendergast MD (2000) Layering and precious metals mineralization in the Rincón del Tigre Complex, Eastern Bolivia. Econ Geol 95:113–130

    CAS  Google Scholar 

  • Prendergast MD, Keays RR (1989) Controls of platinum group element mineralization and the origin of the PGE-rich Main Sulphide Zone of the Great Dyke, Zimbabwe: implications for the genesis of, and the exploration for stratiform PGE mineralization in layered intrusions. In: Prendergast MD, Jones MJ (eds) Magmatic sulphides—the Zimbabwe volume. Inst Mining Metall Lond, pp 43–69

  • Prendergast MD, Wilson AH (1989) The Great Dyke of Zimbabwe—II: mineralisation and mineral deposits. In: Prendergast MD, Jones MJ (eds) Magmatic sulphides—the Zimbabwe volume. Inst Mining Metall Lond, pp 21–42

  • Slatter D (1980) The effects of chemical composition upon the reducibility of Zimbabwean chromium ores. Univ Zimbabwe Inst Mineral Res Rep 43:1–39

    Google Scholar 

  • Streckeisen A (1980) Classification and nomenclature of volcanic rocks, lamprophyres, carbonatites and melilitic rocks. IUGS subcommission on the systematics of igneous rocks. Geol Rundsch 90:194–207

    Google Scholar 

  • Sutphin DM, Page NJ (1986) International strategic minerals inventory summary report—platinum-group metals. US Geol Surv Circ 930-E

  • Tarkian M, Evstigneeva T, Gorshkov A (1996) Synthesis of Pt- and Pd-sulfides in low-temperature (85 °C) solutions buffered by clay minerals and graphite: preliminary results. Mineral Petrol 58:71–78

    CAS  Google Scholar 

  • Verryn SMC, Merkle RKW (1994) Compositional variation of cooperite, braggite, and vysotskite from the Bushveld Complex. Mineral Mag 58:223–234

    CAS  Google Scholar 

  • Verryn SMC, Merkle RKW (2000) Stability fields and Ni-content in synthetic cooperite, braggite and vysotskite between 1,200 °C and 700 °C. In: Rammlmair D, Mederer J, Oberthür T, Heimann RB, Pentinghaus H (eds) Applied mineralogy. Balkema, Rotterdam, pp 451–454

  • Weiser Th, Oberthür T, Kojonen K, Johanson B (1998) Distribution of trace PGE in pentlandite and of PGM in the Main Sulfide Zone (MSZ) at Mimosa Mine, Great Dyke, Zimbabwe. In: Proc 8th Int Platinum Symp. S Afr Inst Mining Metall Symp Ser S18:443–445

    Google Scholar 

  • Wilson AH, Prendergast MD (1989) The Great Dyke of Zimbabwe—I: tectonic setting, stratigraphy, petrology, structure, emplacement and crystallisation. In: Prendergast MD, Jones MJ (eds) Magmatic sulphides—The Zimbabwe Volume. Inst Mining Metall Lond, pp 1–20

  • Wilson AH, Tredoux M (1990) Lateral and vertical distribution of the platinum group elements, and petrogenetic controls on the sulphide mineralisation, in the P 1 Pyroxenite layer of the Darwendale Subchamber of the Great Dyke, Zimbabwe. Econ Geol 85:556–584

    CAS  Google Scholar 

  • Wilson AH, Naldrett AJ, Tredoux M (1989) Distribution and controls of platinum-group element and base metal mineralization in the Darwendale subchamber of the Great Dyke, Zimbabwe. Geology 17:649–652

    Article  CAS  Google Scholar 

  • Wilson AH, Murahwi CZ, Coghill BM (2000a) The geochemistry of the PGE subzone in the Selukwe subchamber, Great Dyke: an intraformational layer model for platinum-group element enrichment in layered intrusions. Mineral Petrol 68:115–140

    Article  CAS  Google Scholar 

  • Wilson AH, Murahwi CZ, Coghill B (2000b) Stratigraphy, geochemistry and platinum group element mineralisation of the central zone of the Selukwe subchamber of the Great Dyke, Zimbabwe. J Afr Earth Sci 30:833–853

    Article  CAS  Google Scholar 

  • Worst BG (1960) The Great Dyke of Southern Rhodesia. S Rhodesia Geol Surv Bull 47

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Acknowledgements

Sincere thanks to G.L. Holland and R. Brown, chief geologists of BHP/Hartley Platinum Mine, as well as P. Vanderspuy, H. Wilhelmij and H. O'Keeffe of Zimplats for their continuous support of our fieldwork in Zimbabwe, editorial suggestions, and permission to publish this paper. K. Kappenschneider of Hartley Platinum Mine kindly provided digital maps. Laboratory work was ably performed by J. Lodziak (electron microprobe), C. Wöhrl (SEM), K. Souto Otero and H. Hummel (map drawings), A. Weitze (image processing), and P. Schlüter and S. Schwarz (data evaluation and drawings). Critical reviews by Johan Kruger, Wolfgang Maier, Frank Melcher, and Oskar Thalhammer, and final comments of the Editor, Bernd Lehmann, considerably improved the paper.

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Correspondence to Thomas Oberthür.

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Oberthür, T., Weiser, T.W., Gast, L. et al. Geochemistry and mineralogy of platinum-group elements at Hartley Platinum Mine, Zimbabwe. Miner Deposita 38, 327–343 (2003). https://doi.org/10.1007/s00126-002-0337-9

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