The Transvaal Epeiric Sea

Abstract

The Early Proterozoic Transvaal and Griqualand West Supergroups (Fig. 5-1) accumulated in a vast epeiric basin, covering at least 500,000 km2 of the Kaapvaal Province. The Transvaal Supergroup is thickest in the northeastern Transvaal, where a fourfold subdivision of the 12,000-m-thick succession is recognized (Fig. 5-2): the Wolkberg Group and the stratigraphically equivalent Buffalo Springs Group in the northwestern Transvaal, the Black Reef Formation, and the Chuniespoort and Pretoria Groups (Button, 1976a). No equivalent of the Wolkberg Group is present in the northern Cape. The Ghaap and Postmasburg Groups of the 4500-m-thick Griqualand West Supergroup correlate with the Chuniespoort and Pretoria Groups of the Transvaal Supergroup.