The Cape Basin, South Africa: A review

Sedimentary rocks of the Palaeozoic Cape Supergroup, Natal Group and Msikaba Formation were deposited on a passive continental margin in a variety of terrestrial and shallow marine-shelf depositional environments, from the early Ordovician until the mid-Carboniferous. Tectonism, which took place between 278 Ma and 230 Ma, affected only the Cape Supergroup rocks and resulted in the Cape Fold Belt. Rocks of the Natal Group and Msikaba Formation were not tectonized. In the Cape Fold Belt, the presence of thrust-stacked successions, together with evidence of thrust-eliminated pelitic units, cast doubt on the reliability of some aspects of the accepted lithostratigraphy. In spite of deficiencies in the available database, it is possible broadly to reconstruct the probable basin history; a rifted continental margin seems a likely setting for the Cape Supergroup, Natal Group and Msikaba deposits.