Cyclicity in the main and upper zones of the Bushveld Complex, South Africa: Crystallization from a zoned magma sheet

Journal of Petrology

Volumn 47, Issue 11, 2006, Pages 2257-2279

  Tegner, Christian ^a   Cawthorn, R Grant ^b   Kruger, F Johan ^c  

^a AARHUS UNIVERSITY   (Denmark)

^b UNIVERSITY OF THE WITWATERSRAND   (South Africa)

^c Moruo Mineralogical Services   (South Africa)

Author keywords

Convection; Differentiation; Isotopes; Layered intrusion; Magma; Mineral chemistry

Indexed keywords

CRYSTALLIZATION; CYCLICITY; ISOTOPIC FRACTIONATION; MAFIC ROCK; MAGMA ASSIMILATION; MAGMA CHEMISTRY; MAGMATIC DIFFERENTIATION; MAGNETITE; OLIVINE; PLAGIOCLASE; PYROXENE;

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

EID: 33750216998     PISSN: 00223530     EISSN: 14602415     Source Type: Journal    
DOI: 10.1093/petrology/egl043     Document Type: Article

References (68)

1. Ariskin, A. A., Frenkel, M. Y., Barmina, G. S. & Nielsen, R. L. (1993). Comagmat: A Fortran program to model magma differentiation processes. Computers & Geosciences 19, 1155-1170.
2. Ashwal, L. D., Webb, S. J. & Knoper, M. W. (2005). Magmatic stratigraphy in the Bushveld northern lobe: Continuous geophysical and mineralogical data from the 2950 m Bellevue drillcore. South African Journal of Geology 108, 199-232.
3. Atkins, F. B. (1969). Pyroxenes of the Bushveld Intrusion, South Africa. Journal of Petrology 10, 222-249.
4. Barnes, S. J. (1986). The effect of trapped liquid crystallization on cumulus mineral compositions in layered intrusions. Contributions to Mineralogy and Petrology 93, 524-531.
5. Bateman, A. M. (1951). The formation of late magmatic oxide ores. Economic Geology 46, 404-426.
6. Buick, I. S., Maas, R. & Gibson, R. (2001). Precise U-Pb titanite age constraints on the emplacement of the Bushveld Complex, South Africa. Journal of the Geological Society, London 158, 3-6.
7. Carr, H. W., Groves, D. I. & Cawthorn, R. G. (1994). The importance of synmagmatic deformation in the formation of Merensky Reef potholes in the Bushveld Complex. Economic Geology 89, 1398-1410.
8. Cawthorn, R. G. & McCarthy, T. S. (1980). Variations in Cr content of magnetite from the Upper Zone of the Bushveld Complex - evidence for heterogeneity and convection currents in magma chambers. Earth and Planetary Science Letters 46, 335-343.
9. Cawthorn, R. G. & McCarthy, T. S. (1985). Incompatible trace element behavior in the Bushveld Complex. Economic Geology 80, 1016-1026.
10. Cawthorn, R. G. & Molyneux, T. G. (1986). Vanadiferous magnetite deposits of the Bushveld Complex. In: Anhaeusser, C. R. & Maske, S. (eds) Mineral Deposits of South Africa. Johannesburg: Geological Society of South Africa, pp. 1251-1266.
11. Cawthorn, R. G. & Walraven, F. (1998). Emplacement and crystallization time for the Bushveld Complex. Journal of Petrology 39, 1669-1687.
12. Cawthorn, R. G. & Walsh, K. L. (1988). The use of phosphorus contents in yielding estimates of the proportion of trapped liquid in cumulates of the Upper Zone of the Bushveld Complex. Mineralogical Magazine 52, 81-89.
13. Cawthorn, R. G. & Webb, S. J. (2001). Connectivity between western and eastern limbs of the Bushveld Complex. Tectonophysics 330, 195-209.
14. Cawthorn, R. G., Meyer, P. S. & Kruger, F. J. (1991). Major addition of magma at the Pyroxenite Marker in the western Bushveld Complex, South Africa. Journal of Petrology 32, 739-763.
15. Cawthorn, R. G., Barnes, S. J., Ballhaus, C. & Malitch, K. N. (2005). Platinum-group element, chromium, and vanadium deposits in mafic and ultramafic rocks. Economic Geology, 100th Anniversary Volume, pp. 215-249.
16. Coffin, M. F. & Eldholm, O. (1994). Large igneous provinces: Crustal structure, dimensions, and external consequences. Reviews of Geophysics 32, 1-36.
17. Eales, H. V. & Cawthorn, R. G. (1996). The Bushveld Complex. In: Cawthorn, R. G. (ed.) Layered Intrusions. Amsterdam: Elsevier, pp. 181-230.
18. Eales, H. V., de Klerk, W. J., Butcher, A. R. & Kruger, F. J. (1990). The cyclic unit beneath the CGI chromitite (UGIFW unit) at RPM Union Section Platinum Mine - Rosetta Stone of the Bushveld Upper Critical Zone? Mineralogical Magazine 54, 23-43.
19. Fox, N. (1982). Variation in plagioclase compositions across magnetitite layers in the eastern Bushveld Complex. University of Cape Town, Honours thesis.
20. Ghiorso, M. S. & Sack, R. O. (1995). Chemical mass transfer in magmatic processes IV. A revised and internally consistent thermodynamic model for the interpolation and extrapolation of liquid-solid equilibria in magmatic systems at elevated temperatures and pressures. Contributions to Mineralogy and Petrology 119, 197-212.
21. Green, T. H. & Watson, E. B. (1982). Crystallization of apatite in natural magmas under high pressure hydrous conditions, with particular reference to 'orogenic' rock series. Contributions to Mineralogy and Petrology 79, 96-105.
22. Harney, D. M. W., Merkle, R. K. W. & von Gruenewaldt, G. (1990). Platinum-group element behavior in the lower part of the Upper Zone, Eastern Bushveld Complex - implications for the formation of the main magnetite layer. Economic Geology 85, 1777-1789.
23. Harney, D. M. W., von Gruenewaldt, G. & Merkle, R. K. W. (1996). The use of plagioclase composition as an indicator of magmatic processes in the Upper Zone of the Bushveld Complex. Mineralogy and Petrology 56, 91-103.
24. Hunter, R. H. & Sparks, R. S. J. (1987). The differentiation of the Skaergaard Intrusion. Contributions to Mineralogy and Petrology 95, 451-461.
25. Irvine, T. N. (1975). Crystallization sequences in the Muskox intrusion and other layered intrusions. 2. Origin of chromitite layers and similar deposits of other magmatic ores. Geochimica et Cosmochimica Acta 39, 991-1008.
26. Irvine, T. N., Keith, D. W. & Todd, S. G. (1983). The J-M Platinum-Palladium Reef of the Stillwater Complex, Montana: II. Origin by double-diffusive convective magma mixing and implications for the Bushveld Complex. Economic Geology 78, 1287-1334.
27. Jackson, E. D. (1961). Primary Textures and Mineral Associations in the Ultramafic Zone of the Stillwater Complex, Montana. US Geological Survey, Professional Papers 358.
28. Jakobsen, J. K., Veksler, I. V., Tegner, C. & Brooks, C. K. (2005). Immiscible iron- and silica-rich melts in basalt petrogenesis documented in the Skaergaard intrusion. Geology 33, 885-888.
29. Klemm, D. D., Henckel, J., Dehm, R. & von Gruenewaldt, G. (1985). The geochemistry of titanomagnetite in magnetite layers and their host rocks of the Eastern Bushveld Complex. Economic Geology 80, 1075-1088.
30. Kretz, R. (1963). Distribution of magnesium and iron between orthopyroxene and calcic pyroxene in natural mineral assemblages. Journal of Geology 71, 773-785.
31. Kruger, F. J. (1994). The Sr-isotopic stratigraphy of the western Bushveld Complex. South African Journal of Geology 97, 393-398.
32. Kruger, F. J. (2005). Filling the Bushveld Complex magma chamber: lateral expansion, roof and floor interaction, magmatic unconformities, and the formation of giant chromitite, PGE and T-V-magnetitite deposits. Mineralium Deposita 40, 451-472.
33. Kruger, F. J. & Smart, R. (1987). Diffusion of trace elements during bottom crystallization of double-diffusive convection systems: The magnetitite layers of the Bushveld Complex. Journal of Volcanology and Geothermal Research 34, 133-142.
34. Kruger, F. J., Cawthorn, R. G. & Walsh, K. L. (1987). Strontium isotopic evidence against magma addition in the Upper Zone of the Bushveld Complex. Earth and Planetary Science Letters 84, 51-58.
35. Lee, C. A. (1996). A review of mineralizations in the Bushveld Complex and some other layered intrusions. In: Cawthorn, R. G. (ed.) Layered Intrusions. Amsterdam: Elsevier, pp. 103-145.
36. Lipin, B. R. (1993). Pressure increase, the formation of chromitite layers and the development of the Ultramafic Series in the Stillwater Complex. Journal of Petrology 34, 955-976.
37. Lundgaard, K. L., Tegner, C., Cawthorn, R. G., Kruger, F. J. & Wilson, J. R. (1993). Trapped intercumulus liquid in the Main Zone of the eastern Bushveld Complex, South Africa. Contributions to Mineralogy and Petrology 151, 352-369.
38. McBirney, A. R. (1993). Igneous Petrology. 2nd edn. Boston, MA: Jones & Bartlett, pp. 508.
39. McBirney, A. R. & Noyes, M. N. (1979). Crystallization and layering of the Skaergaard intrusion. Journal of Petrology 20, 487-554.
40. Merkle, R. K. W. & von Gruenewaldt, G. (1986). Compositional variation of Co-rich pentlandite: Relation to the evolution of the Upper Zone of the western Bushveld Complex, South Africa. Canadian Mineralogist 24, 529-546.
41. Mitchell, A. A., Eales, H. V. & Kruger, F. J. (1998). Magma replenishment, and the significance of poikilitic textures, in the Lower Main Zone of the western Bushveld Complex, South Africa. Mineralogical Magazine 62, 435-450.
42. Molyneux, T. G. (1972). X-ray data and chemical analyses of some titanomagnetite and ilmenite samples from the Bushveld Complex, South Africa. Mineralogical Magazine 48, 863-871.
43. Molyneux, T. G. (1974). A geological investigation of the Bushveld Complex in Sekhukhuneland and part of the Steelpoort valley. Transactions of the Geological Society of South Africa 77, 329-338.
44. Morse, S. A. (1984). Cation diffusion in plagioclase feldspar. Science 225, 504-505.
45. Nex, P. A., Kinnaird, J. A., Ingle, L. J., Van der Vyver, B. A. & Cawthorn, R. G. (1998). A new stratigraphy for the Main Zone of the Bushveld Complex, in the Rustenburg area. South African, Journal of Geology 101, 215-223.
46. Reynolds, I. M. (1985a). The nature and origin of titaniferous magnetite-rich layers in the Upper Zone of the Bushveld Complex: A review and synthesis. Economic Geology 80, 1089-1108.
47. Reynolds, I. M. (1985b). Contrasted mineralogy and textural relationships in the uppermost titaniferous magnetite layers of the Bushveld Complex in the Bierkraal area north of Rustenburg. Economic Geology 80, 1027-1048.
48. Sharpe, M. R. (1985). Strontium isotope evidence for preserved density stratification in the Main Zone of the Bushveld Complex. Nature 316, 119-126.
49. Spulber, S. D. & Rutherford, M. J. (1983). The origin of rhyolite and plagiogranite in oceanic crust: An experimental study. Journal of Petrology 24, 1-25.
50. Tegner, C. (1997). Iron in plagioclase as a monitor of the differentiation of the Skaergaard intrusion. Contributions to Mineralogy and Petrology 128, 45-51.
51. Tegner, C., Robins, B., Reginiussen, H. & Grundvig, S. (1999). Assimilation of crustal xenoliths in a basaltic magma chamber: Sr and Nd isotopic constraints from the Hasvik Layered Intrusion, Norway. Journal of Petrology 40, 363-380.
52. Toplis, M. J. (2005). The thermodynamics of iron and magnesium partitioning between olivine and liquid: Criteria for assessing and predicting equilibrium in natural and experimental systems. Contributions to Mineralogy and Petrology 149, 22-39.
53. Toplis, M. J. & Carroll, M. R. (1995). An experimental study of the influence of oxygen fugacity on Fe-Ti oxide stability, phase relations, and mineral-melt equilibria in ferro-basaltic systems. Journal of Petrology 36, 1137-1170.
54. Toplis, M. J. & Corgne, A. (2002). An experimental study of element partitioning between magnetite, clinopyroxene and iron-bearing silicate liquids with particular emphasis on vanadium. Contributions to Mineralogy and Petrology 144, 22-37.
55. Toplis, M. J., Libourel, G. & Carroll, M. R. (1994). The role of phosphorus in crystallization processes of basalt: An experimental study. Geochimica et Cosmochimica Acta 58, 797-810.
56. 2) of the Bjerkreim-Sokndal layered intrusion (Norway). Contributions to Mineralogy and Petrology 118, 60-78.
57. von Gruenewaldt, G. (1970). On the phase change orthopyroxene-pigeonite and the resulting textures in the Main and Upper Zones of the Bushveld Complex in the eastern Transvaal. In: Visser, D. J. L. & von Gruenewaldt, G. (eds) Symposium on the Bushveld Igneous Complex and Other Layered Intrusions. Johannesburg: Geological Society of South Africa, pp. 67-73.
58. von Gruenewaldt, G. (1971). A petrological and mineralogical investigation of the rocks of the Bushveld Igneous Complex in the Tauteshoogte-Roossenekal area of the eastern Transvaal. University of Pretoria, D.Sc. thesis.
59. von Gruenewaldt, G. (1973). The Main and Upper zones of the Bushveld Complex in the Roossenekal area, Eastern Transval. Transactions of the Geological Society of South Africa 76, 207-227.
60. von Gruenewaldt, G. (1993). Ilmenite-apatite enrichments in the Upper Zone of the Bushveld Complex: A major titanium-rock phosphate resource. International Geology Review 35, 987-1000.
61. von Gruenewaldt, G., Klemm, D. D., Henckel, J. & Dehm, R. M. (1985). Exsolution features in titanomagnetites from massive magnetitite layers and their host rocks of the Upper Zone, eastern Bushveld Complex. Economic Geology 80, 1049-1061.
62. Wager, L. R. (1960). The major element variation of the layered series of the Skaergaard intrusion and a re-estimation of the average composition of the hidden series and of successive residual magmas. Journal of Petrology 1, 364-398.
63. Wager, L. R. (1963). The mechanism of adcumulus growth in the layered series of the Skaergaard intrusion. In: Fisher, D. J., Frueh, A. J., Hurlbert, C. S. & Tilley, C. E. (eds) Symposium on Layered Intrusions. Mineralogical Society of America, Special Paper 1, 1-9.
64. Wager, L. R. & Brown, G. M. (1968). Layered Igneous Rocks. London: Oliver & Boyd, pp. 572.
65. Walraven, F. (1987). Textural, Geochemical and Genetic Aspects of the Granophyric Rocks of the Bushveld Complex. Memoirs of the Geological Survey of South Africa 72, 145 pp.
66. Walraven, F. & Wolmarans, L. G. (1979). Stratigraphy of the upper part of the Rustenburg Layered Suite, Bushveld Complex, in the western Transvaal. Annals of the Geological Survey of South Africa 13, 109-114.
67. Willemse, J. (1969a). The geology of the Bushveld Igneous Complex, the largest repository of magmatic ore deposits in the world. Economic Geology Monograph 4, 1-22.
68. Willemse, J. (1969b). The vanadiferous magnetic iron ore of the Bushveld Igneous Complex. Economic Geology Monograph 4, 187-208.