Abstract
A suite of 30 samples was collected from the Burgersfort bulge area of the eastern Bushveld Complex for a detailed quantitative textural study. The studied section represents a stratigraphic column approximately 1,000 m thick, of mainly orthopyroxenites from the lower zone (LZ) and lower critical zone. Crystal size distribution (CSD) plots and quantitative fabric analyses reveal a history of crystal aging and compaction, as evident from the loss of smaller-sized crystals and the development of foliation with little evidence of mineral lineation. Compared with the thicker section from Jagdlust (~80 km north), the LZ orthopyroxenites at Burgersfort are consistently finer grained. Foliation is equally well developed at both locations and is consistent with a relatively thin compaction zone at the top of the mush column. Grain size is largely a function of local cooling history with a grain size growth exponent estimated to be between 2.0 and 3.4.
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Acknowledgements
This work was supported by NSF grants EAR 02-06905 and 04-07928. It was improved with reviews by A. R. McBirney, Nathan Chutas and an unnamed reviewer, whose input is very much appreciated.
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Communicated by: T. L. Grove
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Williams, E., Boudreau, A.E., Boorman, S. et al. Textures of orthopyroxenites from the Burgersfort bulge of the eastern Bushveld Complex, Republic of South Africa. Contrib Mineral Petrol 151, 480–492 (2006). https://doi.org/10.1007/s00410-006-0072-9
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DOI: https://doi.org/10.1007/s00410-006-0072-9