Variable initial Pb isotopic compositions of rocks associated with the UG2 chromitite, eastern Bushveld Complex

Geochimica et Cosmochimica Acta

Volumn 71, Issue 22, 2007, Pages 5514-5527

  Mathez, E A ^a   Kent, A J R ^b  

^a DIVISION OF INVERTEBRATE ZOOLOGY   (United States)

^b OREGON STATE UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

CHROMITITE; IGNEOUS GEOCHEMISTRY; ISOTOPIC COMPOSITION; LEAD ISOTOPE; MAGMA; PLAGIOCLASE; SOLIDIFICATION; SULFIDE;

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

EID: 35648940672     PISSN: 00167037     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.gca.2007.09.014     Document Type: Article

References (48)

1. Asmerom Y., and Jacobsen S. B. (1993) The Pb isotopic evolution of the Earth: inferences from river water suspended loads. Earth Planet. Sci. Lett. 115, 245-256.
2. Ashwal L.D., Webb S.J., and Knoper M.W. Physical and mineralogical properties of Bushveld rocks: magnetic susceptibility, density and mineral chemistry profiles in the 2950 m Bellevue drillcore, Northern Lobe. S. Afr. J. Geol. 108 (2005) 199-232
3. Baker J.A., Peate D.W., Waight T., and Meyzen C. Pb isotopic analysis of standards and samples using a Pb-207-Pb-204 double spike and thallium to correct for mass bias with a double-focusing MC-ICP-MS. Chem. Geol. 211 (2004) 275-303
4. Brenan J.M., Cherniak D.J., and Rose L.A. Diffusion of osmium in pyrrhotite and pyrite; implications for closure of the Re-Os isotopic system. Earth Planet. Sci. Lett. 180 (2000) 399-413
5. Buick I.S., Maas R., and Gibson R. Precise U-Pb titanite age constraints on the emplacement of the Bushveld Complex, South Africa. J. Geol. Soc. Lond. 158 (2001) 3-6
6. Button A. The Transvaal sub-basin of the Transvaal sequence. In: Anhaeusser C.R., and Maske S. (Eds). Mineral Deposits of Southern Africa (1986), Geological Society of South Africa, Johannesburg 811-817
7. Cameron E.N. The lower zone of the eastern Bushveld Complex in the Olifants River Trough. J. Petrol. 19 (1978) 437-462
8. Cameron E.N. Evolution of the lower critical zone, central sector, eastern Bushveld Complex, and its chromite deposits. Econ. Geol. 75 (1980) 845-871
9. Cameron E.N. The upper critical zone of the eastern Bushveld Complex-precursor of the Merensky Reef. Econ. Geol. 77 (1982) 1307-1327
10. Condie K.C. Chemical composition and evolution of the upper continental crust: contrasting results from surface samples and shales. Chem. Geol. 104 (1993) 1-37
11. Cawthorn R.G., and Walraven F. Emplacement and crystallization time for the Bushveld Complex. J. Petrol. 39 (1998) 1669-1687
12. Cawthorn R.G., and Webb S.J. Connectivity between the western and eastern limbs of the Bushveld Complex. Tectonophysics 330 (2001) 95-209
13. Chen J. H., and Wasserburg G. J. (1983) The least radiogenic Pb in iron meteorites (abs). In Proceedings of 14th Lunar Planet. Sci. Conf., Pt. 1, Lunar and Planet. Inst., Houston, pp. 103-104.
14. Cherniak D.J. Diffusion of lead in plagioclase and K-feldspar: an investigation using Rutherford backscatter and resonant nuclear reaction analysis. Contrib. Mineral. Petrol. 120 (1995) 358-371
15. Eales H.V., and Cawthorn R.G. The Bushveld Complex. In: Cawthorn R.G. (Ed). Layered Intrusions (1996), Elsevier Science, Amsterdam 181-229
16. Galer S.J.G., and Goldstein S.L. Influence of accretion on lead in the Earth. In: Basu A., and Hart S. (Eds). Earth Processes: Reading the Isotopic Code. Geophys. Mono. Vol. 95 (1996), American Geophysical Union, Washington 75-98
17. Hamilton J. Isotope and trace element studies of the Great Dike and Bushveld mafic phase. J. Petrol. 18 (1977) 24-52
18. Harmer R.E., Auret J.M., and Eglington B.M. Lead isotope variations within the Bushveld Complex, Southern Africa: a reconnaissance study. J. Afr. Earth Sci. 21 (1995) 595-606
19. Harris C., Pronost J.J.M., Ashwal L.D., and Cawthorn R.G. Oxygen and hydrogen isotope stratigraphy of the Rustenburg layered suite, Bushveld Complex: Constraints on crustal contamination. J. Petrol. 46 (2005) 579-601
20. Hart S.R., and Kinloch E.D. Osmium isotope systematics in Witwatersrand and Bushveld ore deposits. Econ. Geol. 84 (1989) 1651-1655
21. Hooper P.R. The Columbia River Flood Basalt Province: current status. In: Mahoney J.J., and Coffin M.F. (Eds). Large Igneous Provinces: Continental, Oceanic, and Planetary Flood Volcanism. Geophys. Mono. Vol. 100 (1997), American Geophysical Union, Washington, D.C 1-27
22. Irvine T.N. Heat transfer during solidification of layered intrusions. I. Sheets and sills. Can. J. Earth Sci. 7 (1970) 1031-1061
23. Kent A. J. R. (in press) In situ analysis of Pb isotope ratios using laser ablation MC-ICP-MS: controls on precision and accuracy and comparison between Faraday cup and ion counting systems. J. Anal. Atom. Spect.
24. Kinnaird J. A., Kruger F. J., Nex P. A. M., and Cawthorn R. G. (2002) Chromitites of the Bushveld Complex-processes of formation and PGE enrichment. Economic Geology Research Institute Information Circular 369, University of Witwatersrand, p. 26.
25. 86Sr ratios in the Merensky cyclic unit of the Bushveld Complex. Nature 298 (1982) 53-55
26. Kruger F.J. The Sr-isotope stratigraphy of the western Bushveld Complex. S. Afr. J. Geol. 97 (1994) 393-398
27. Lambert D.D., and Simmons E.C. Magma evolution in the Stillwater Complex, Montana; II, rare earth element evidence for the formation of the J-M Reef. Econ. Geol. 83 (1988) 1109-1126
28. Lee C.A., and Butcher A.R. Cyclicity in the Sr isotope stratigraphy through the Merensky and Bastard reef units, Atok section, eastern Bushveld Complex. Econ. Geol. 85 (1990) 877-883
29. Maier W.D., Arndt N.T., and Curl E.A. Progressive crustal contamination of the Bushveld Complex: evidence from Nd isotopic analyses of the cumulate rocks. Contrib. Mineral. Petrol. 140 (2000) 316-327
30. Marcantonio F., Zindler A., Reisberg L., and Mathez E.A. Re-Os isotopic systematics in chromitites from the Stillwater Complex. Geochim. Cosmochim. Acta 57 (1993) 4029-4037
31. Mathez E.A., and Mey J.L. Character of the UG2 chromitite and host rocks and petrogenesis of its pegmatoidal footwall, northeastern Bushveld Complex. Econ. Geol. 100 (2005) 1617-1630
32. Mathez E.A., and Waight T.E. Lead isotopic disequilibrium between sulfide and plagioclase in the bushveld complex and the chemical evolution of large layered intrusions. Geochim. Cosmochim. Acta 67 (2003) 1875-1888
33. Mathez E.A., Hunter R.H., and Kinzler R. Petrologic evolution of partially molten cumulate: the Atok section of the Bushveld Complex. Contrib. Mineral. Petrol. 129 (1997) 20-34
34. McBirney A.R., and Creaser R.A. The Skaergaard layered series; part VII, Sr and Nd isotopes. J. Petrol. 44 (2003) 757-771
35. McCandless T.E., and Ruiz J. Osmium isotopes and crustal sources for platinum-group mineralization in the Bushveld Complex, South Africa. Geology 19 (1991) 1225-1228
36. McCandless T.E., Ruiz J., Adair B.I., and Freydier C. Re-Os isotope and Pd/Ru variations in chromitites from the Critical zone, Bushveld Complex, South Africa. Geochim. Cosmochim. Acta 63 (1999) 911-923
37. Molyneux T.G. A geological investigation of the Bushveld Complex in Sekhukhuneland and part of the Steelpoort valley. Trans. Geol. Soc. S. Afr. 77 (1974) 329-338
38. Mondal S.K., and Mathez E.A. Origin of the UG2 chromitite layer, Bushveld Complex. J. Petrol. 48 (2007) 495-510
39. 238U ratio (κ) of the continental crust. Geochem. Geophys. Geosyst. 4 12 (2003) 1102 10.1029/2002GC000497
40. Prevec S.A., Ashwal L.D., and Mkaza M.S. Mineral disequilibrium in the Merensky Reef, western Bushveld Complex, South Africa: new Sm-Nd isotopic evidence. Contrib. Mineral. Petrol. 149 (2005) 306-315
41. Scoates J. S., and Friedman R. M. (2006) Precise crystallization age of the Bushveld Complex, South Africa: Direct dating of the platiniferous Merensky Reef using the zircon U-Pb chemical abrasion Id-TIMS technique.
42. Schoenberg R., Kruger F.J., Nägler T.F., Meisel T., and Kramers J.D. 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. 172 (1999) 49-64
43. Sharpe M. Strontium isotope evidence for preserved density stratification in the Main Zone of the Bushveld Complex, South Africa. Nature 316 (1985) 119-126
44. Tepley F.J., and Davidson J.P. Mineral-scale Sr-isotope constraints on magma evolution and chamber dynamics in the Rum layered intrusion, Scotland. Contrib. Mineral. Petrol. 145 (2003) 628-641
45. Von Gruenewaldt G. The Main and Upper Zones of the Bushveld Complex in the Roossenekal area, eastern Transvaal. Trans. Geol. Soc. S. Afr. 76 (1973) 207-227
46. Webb S.J., Cawthorn R.G., Nguuri T., and James D. Gravity modeling of Busvheld Complex connectivity supported by southern African seismic experiment results. S. Afr. J. Geol. 107 (2004) 207-218
47. Weis D., Morse S. A., and Scoates J. S. (2003) Mineral-scale and regional isotopic heterogeneity within the Kiglapait Intrusion and other amfic intrusions of the ca. 1.3 Ga Nain Plutonic Suite, Labrador. Geological Society of America Ann. Mtg, Abstracts with Programs 35.
48. Zhang Y. The age and accretion of the Earth. Earth Sci. Rev. 59 (2002) 235-263