1. Textures of orthopyroxenites from the Burgersfort bulge of the eastern Bushveld Complex, Republic of South Africa.
- Author
-
Williams, E., Boudreau, A. E., Boorman, S., and Kruger, F. J.
- Subjects
- *
PYROXENITE , *IGNEOUS rocks , *CRYSTALS , *DIFFERENTIAL topology , *FOLIATIONS (Mathematics) , *EXPONENTIAL functions , *COMPLEXES (Stratigraphy) , *MINERALS - 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. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF