Alteration and metasomatism of the UG2 melanorite and its stratiform pegmatoids, Bushveld complex, South Africa - Characteristics, timing and origins.

South African Journal of Geology

Volumn 112, Issue 1, 2009, Pages 47-64

  Voordouw, R J ^a   Beukes, N J ^a  

^a UNIVERSITY OF JOHANNESBURG   (South Africa)

Author keywords

[No Author keywords available]

Indexed keywords

CHROMITITE; GRAIN SIZE; HYDROTHERMAL FLUID; IGNEOUS INTRUSION; METASOMATISM; SLURRY; STRATIFORM DEPOSIT; TEMPORAL PERIOD; VEIN (GEOLOGY);

AFRICA; BUSHVELD COMPLEX; SOUTH AFRICA; SOUTHERN AFRICA; SUB-SAHARAN AFRICA;

EID: 67650809031     PISSN: 10120750     EISSN: None     Source Type: Journal    
DOI: 10.2113/gssajg.112.1.47     Document Type: Article

References (64)

1. AcmeLabs (2009). Services & Fees 2009. Corporate brochure, Vancouver, Canada.
2. Banks, D. A., Yardley, B. W. D., Campbell, A. R. and Jarvis, K. E. (1994). REE composition of an aqueous magmatic fluid: a fluid inclusion study from the Capilan Pluton, New Mexico, United States of America. Chemical Geology, 113, 259-272.
3. Bateman, A. M. (1951). The formation of late magmatic oxide ores. Economic Geology, 46, 404-426.
4. Blundy, J. D. and Holland TJ. B. (1990). Calcic amphibole equilibria and a new amphibole-plagioclase geothermometer. Contributions to Mineralogy and Petrology, 104, 208-224.
5. Boorman, S. L., McGuire, J. B., Boudreau, A. E. and Kruger, F. J. (2003). Fluid overpressure in layered intrusions: formation of a breccia pipe in the eastern Bushveld Complex, Republic of South Africa. Mineralium Deposita, 38, 356-369.
6. Boudreau, A. E., Mathez, E. A. and McCallum, I. S. (1986). Halogen chemistry of the Stillwater and Bushveld Complexes: evidence for the transport of the platinum group elements by Cl-rich fluids. Journal of Petrology, 27, 967-986.
7. Buchanan, D. L. Nolan, J., and Viljoen, E. A. (1980). Determination of silica activity in Bushveld rocks. Contributions to Mineralogy and Petrology, 73, 311-319.
8. Cameron, E. N. and Emerson, M. E. (1959). The origin of certain chromite deposits of the eastern part of the Bushveld Complex. Economic Geology, 54, 1151-1213.
9. Cawthorn, R. G. (1999). Platinum-Group element mineralization in the Bushveld Complex-a critical reassessment of geochemical models. South African Journal of Geology, 102, 268-281.
10. Cawthorn, R. G. and Barry, S. D. (1992). The role of intercumulus residua in the formation of pegmatoid associated with the UG2 chromitite, Bushveld Complex. Australian Journal of Earth Sciences, 39, 263-276.
11. Cawthorn, R. G., Barton, J. M. and Viljoen, M. J. (1985). Interaction of floor rocks with the Platreef on Overysel, Potgietersrus, northern Transvaal. Economic Geology, 80, 988-1006.
12. Cawthorn, R. G., and Boerst, K. (2006). Origin of the pegmatitic pyroxenite in the Merensky Unit, Bushveld Complex, South Africa. Journal of Petrology, 47. 1509-1530.
13. Cawthorn, R. G., Bales, H. V., Walraven, F, Uken, R. and Watkeys, M. K. (2006). The Bushveld Complex. In: M. R. Johnson, C. R., Anhaeusser and R. J. Thomas (Editors), Geology of South Africa. Geological Society of South Africa/Council for Geoscience, South Africa, 261-281.
14. Cawthorn, R. G., Harris, C. and Kruger, F. J. (2000). Discordant ultramafic pegmatoidal pipes in the Bushveld Complex. Contributions to Mineralogy and Petrology, 140, 119-133.
15. Cawthorn, R. G., Merkle, R. K. W. and Viljoen, MJ. (2002). Platinum-group element deposits in the Bushveld Complex, South Africa. In: L. J. Cabri (Editor), The geology, geochemistry, mineralogy and mineral beneficiation of platinum-group elements. Canadian Institute of Metallurgy and Petrology, Special Issue, 54, 389-430.
16. Cawthorn, R. G. and Poulton, K. L. (1988). Evidence for fluid in the footwall beneath potholes in the Merensky Reef of the Bushveld Complex. In: H. M. Prichard, P. J. Potts, J. F. W. Bowles and S. J. Cribbs (Editors), Geoplatinum 87, Elsevier, Amsterdam, The Netherlands, 343-356.
17. Cawthorn, R. G. and Spies, L. (2003). Plagioclase contents of cyclical units in the Bushveld Complex, South Africa. Contributions to Mineralogy and Petrology, 145, 47-60.
18. Deer, W. A., Howie, R. A. and Zussman, J. (1992). An introduction to the rockforming minerals. 2nd Edition, Longman Scientific and Technical, Harlow, United Kingdom. 696pp.
19. Eales, H. V. (2000). Implications of the chromium budget of the Western Limb of the Bushveld Complex. South African Journal of Geology, 103, 141-150.
20. Eales, H. V. and Reynolds, I. M. (1986). Cryptic variations within chromitites of the Upper Critical Zone, Northanging wallestern Bushveld Complex. Economic Geology, 81, 1056-1066.
21. Edwards, S. J., Pearce, J. A. and Freeman, J. (2000). New insights concerning the influence of water during the formation of podiform chromitite. Geological Society of America Special Paper, 349, 139-147.
22. Fisher, LAV. (1929). Origin of chromite deposits. Economic Geology, 24, 691-721
23. Fockema, R. A. P. and Mendelssohn, E. (1954). Note on an unusual occurrence of chromite in the Eastern Transvaal. Transactions of the Geological Society of South Africa, 57, 77-82.
24. Gain, S. B. (1985). The geologic setting of the platiniferous UG-2 chromitite layer on the farm Maandagshoek, eastern Bushveld Complex. Economic Geology, 80, 925-943.
25. Gauert, C. (1995). Geology of the ultrabasic to basic Uitkomst complex, eastern Transvaal, South Africa: an overview. Journal of African Earth Sciences, 21, 553-570.
26. Haskin, L. A., Haskin, M. A., Frey, F. A. and Wildman, T. R. (1968). Relative and absolute abundances of the rare earths. In: L. H. Ahren (Editor), Origin and distribution of the elements, Pergamon, Oxford, United Kingdom, 1, 889-911.
27. Hess, H. H. (1960). Stillwater Igneous Complex, Montana. A quantitative mineralogical study. Geological Society of America Memoir, 80, 230pp.
28. Holland, T. and Blundy, J. (1994). Non-ideal interactions in calcic amphiboles and their bearing on amphibole-plagioclase thermometry. Contributions to Mineralogy and Petrology, 116, 433-447.
29. Holwell, D. A., McDonald, I. and Armitage, P. E. B. (2006). Platinum-group mineral assemblages in the Platreef at the Sandsloot Mine, northern Bushveld Complex, South Africa. Mineralogical Magazine, 70, 83-101.
30. Hunter, R. H. (1996). Texture development in cumulate rocks. In: R. G. Cawthorn (Editor), Layered Intrusions, Elsevier, Amsterdam, The Netherlands, 77-101.
31. Irvine, T. N. (1977). Origin of chromite layers in the Muskox intrusion and other stratiform intrusions; a new interpretation. Geology, 5, 273-277.
32. Kinloch, E. D. (1982). Regional trends in the platinum-group mineralogy of the Critical Zone of the Bushveld Complex, South Africa. Economic Geology, 77, 1328-1347.
33. Kinnaird, J. A., Kruger, F. J., Nex, P. A. M. and Cawthorn, R. G. (2002). Chromitite formation - a key to understanding processes of platinum enrichment. Applied Earth Sciences, 111, 23-35.
34. Kretz, R. (1983). Symbols for rock-forming minerals. American Mineralogist, 68, 277-279.
35. Leeb-Du Toit, A. (1986). The Impala Platinum mines. In: C. R. Anhaeusser and S. Maske (Editors), Mineral deposits of Southern Africa, Geological Society of South Africa, 1091-1106.
36. Li, C, Ripley, E. M., Merino, E. and Maier, W. (2004). Replacement of base metal. sulfides by actinolite, epidote, calcite and magnetite in the UG2 and Merensky Reef of the Bushveld Complex, South Africa. Economic Geology, 99, 173-184.
37. Li, C, Ripley, E. M., Sarkar, A., Shin, D. and Maier, W. (2005). Origin of phlogopite-orthopyroxene inclusions in chromitites from the Merensky Reef of the Bushveld Complex, South Africa. Contributions to Mineralogy and Petrology, 150, 119-130.
38. Maier, W. D. and Eales, H. V. (1997). Correlation within the UG2-Merensky Reef interval of the western Bushveld Complex. Geological Survey of South Africa Bulletin, 120, 120 pp.
39. Marsh, B. (1981). On the crystallinity, probability of occurrence, and rheology of lava and magma. Contributions to Mineralogy and Petrology, 78, 85-98.
40. Mathez, E. A. (1989). Interactions involving fluids in the Stillwater and Bushveld Complexes: observations from the rocks. Reviews in Economic Geology, 4, 167-179.
41. Mathez, E. A. and Mey, J. L. (2005). Character of the UG2 chromitite and host rocks and petrogenesis of its pegmatoidal footwall, northeastern Bushveld Complex. Economic Geology, 100, 1617-1630.
42. Matveev, S. and Ballhaus, C. (2002). Role of water in the origin of podiform chromitite deposits. Earth and Planetary Science Letters, 15, 235-243.
43. McCallum, I. S., Raedeke, L. D. and Mathez, E. A. (1980). Investigations of the Stillwater Complex: Part I. Stratigraphy and structure of the banded zone. American Journal of Science, 280, 59-87.
44. McLaren, C. H. and De Villiers, J. P. R. (1982). The platinum-group chemistry and mineralogy of the UG-2 chromitite layer of the Bushveld Complex. Economic Geology, 77, 1348-1366.
45. Meurer, W. P., and Boudreau, A. E. (1998). Petrology and mineral compositions of the Middle Banded series of the Stillwater Complex, Montana. Journal of Petrology, 37, 583-607.
46. Mondal, S. K. and Mathez, E. A. (2007). Origin of the UG2 chromitite layer, Bushveld Complex. Journal of Petrology, 48, 495-510.
47. Nakamura, N. (1974). Determination of REE, Ba, Fe, Mg, Na and K in carbonaceous and ordinary chondrites. Geochimica et Cosmochimica Acta, 38, 757-775.
48. Naldrett, A. J. (1989). Magmatic sulfide deposits. Oxford University Press, United Kingdom. 177pp.
49. Nicholson, D. M., and Mathez, E. A. (1991). Petrogenesis of the Merensky reef in the Rustenburg section of the Bushveld Complex. Contributions to Mineralogy and Petrology, 141, 643-658.
50. Penberthy, C. J. and Merkle, R. K. W. (1999). Lateral variations in the platinumgroup element content and mineralogy of the UG2 chromitite layer, Bushveld Complex. South African Journal of Geology, 102, 240-250.
51. Peyerl, W. (1982). The influence of the Driekop dunite pipe on the platinumgroup element mineralogy of the UG2 chromitite in its vicinity. Economic Geology, 77, 1432-1438.
52. Roeder, P. L. and Reynolds, I. (1991). Crystallisation of chromite and chromium solubility in basaltic melts. Journal of Petrology, 32, 909-934.
53. Ross, C. S. (1929). Is chromite always a magmatic segregation product? Economic Geology, 24, 641-645
54. Sampson, E. (1929). May chromite crystallise late? Economic Geology, 24, 632-641.
55. Sampson, E. (1932). Magmatic chromite deposits of southern Africa. Economic Geology, 28, 113-139.
56. Schiffries, CM. (1982). The petrogenesis of a platiniferous dunite pipe in the Bushveld Complex: infiltration metasomatism by a chloride solution. Economic Geology, 77, 1439-1453.
57. Schoenberg, R., Kruger, F. J., Nagler, T. F., Meisel, T. and Kramers, J. D. (1999). PGE enrichment in chromitite layers and the Merensky Reef of the western Bushveld Complex: A Re-Os and Rb-Sr isotope study. Earth and Planetary Science Letters, 172, 49-64.
58. Scoon, R. N. and Teigler, B. (1994). Platinum-group element mineralisation in the Critical Zone of the western Bushveld Complex: I. Sulphide poorchromitites below the UG-2. Economic Geology, 89, 1094-1121
59. Spear, F. S. (1981). Amphibole-plagioclase equilibria: an empirical model for the relation albite + tremolite=edenite + 4 quartz. Contributions to Mineralogy and Petrology, 77, 355-364.
60. Taylor, R. P. and Fryer, B. J. (1980). Multiple-stage hydrothermal alteration in porphyry copper systems in northern Turkey: the temporal interplay of potassic, propyllitic and phyllic fluids. Canadian Journal of Earth Sciences, 17, 901-926.
61. Thompson, R. N. (1982). Magmatism of the British Tertiary province. Scottish Journal of Geology, 18, 49-107.
62. Viljoen, M. J. (1999). The nature and origin of the Merensky Reef of the western Bushveld Complex based on geological facies and geophysical data. South African Journal of Geology, 102, 221-239.
63. Viljoen, MJ. and Scoon, R. N. (1985). The distribution and main geologic features of discordant bodies of iron-rich ultramafic pegmatite in the Bushveld Complex. Economic Geology, 80, 1100-1128.
64. Zingg, A. J. (1996). Recrystallisation and the origin of layering in the Bushveld Complex. Lithos, 37, 15-37.