A review of the Stormberg Group and Drakensberg volcanics in southern Africa

Abstract

The Molteno Sandstone, Red Beds and Cave Sandstone comprising the Stormberg Group (siliciclastics) in South Africa and their correlatives, based on lithology, depositio- nal environments and tectonic cycles, in Zimbabwe, Botswana and Namibia are described. The Drakensberg Volcanics with radiometric ages of 114 My to 194 My cap the sedimen- tary sequence. A major unconformity separates the Stormberg sedimentary rocks from the lower Karoo strata. Four Late Triassic depositional basins which were tectonically controlled are recognised. The Molteno Sandstone and Red Beds filling these basins represent braided and meandering stream deposits respectively. The Cave Sandstone covering the fluvial deposits formed as desert sand sheets reworked by westerly winds. Deposition was ended by the outpouring of the Drakensberg Volcanics.