Post-Transvaal deformation between the Johannesburg dome and the Bushveld complex

Abstract

The study of an area north of the Johannesburg Dome has revealed that the rocks of the Transvaal Supergroup have been affected by widespread deformation, as well as metamorphism to the greenschist facies. Thermal modelling suggests that the metamorphism, and hence porphyroblast growth, can probably be attrIbuted to the thermal effect of the Bushveld Complex. Thus, textural relationships between porphyroblasts and cleavage microstructure in slates could be utilized to establish the relative timing of ductile deformation events in the area. (Abbreviation abstract)