Abstract In 1970, the National Committee for Geological Sciences accepted in principle the ISSC recommendations for stratigraphic classification and a South African Committee for Stratigraphy (SACS) was appointed. A local code was published in 1971 and, through working groups, SACS has revised and completely reclassified the South African stratigraphic column. The former and the revised principal stratigraphic subdivisions are presented in tables. The principal lithostratigraphic units in the main Precambrian basins of deposition are being termed supergroups, groups, and sequences; the former Swaziland, Witwatersrand, and Ventersdorp Systems" are now Supergroups; the Pongola, Dominion Reef, and Waterberg "Systems are Groups; and the Transvaal System" is now the Transvaal and Griqualand-West sequences with component groups. The term Bushveld Complex replaces Bushveld Igneous Complex. The Gariep and Nosib Groups (formerly "Systems") have been placed in the Damara Supergroup. The Nama "System" which spans the Precambrian-Phanerozoic boundary has become a Group; its counterpart in the southwestern Cape Province, which is intruded by the Cape Granite, is now termed the Malmesbury Group. For the Phanerozoic, SACS decided that the Cape "System" becomes the Cape Supergroup and the Karoo "System" a sequence. In the Cape Supergroup the major units are now termed the Table Mountain, Bokkeveld, and Witteberg Groups. In the Karoo sequence, the Dwyka Tillite Formation forms the base followed by the Ecca, Beaufort, and Drakensberg Groups. The widespread dolerites intrusive into the Karoo are still collectively referred to as Karoo Dolerites. In the Jurassic-Cretaceous, the term Beds has been abandoned and Suurberg, Uitenhage, and Zululand Groups are defined. The problem of subdividing the Precambrian chronostratigraphically is discussed. In South Africa there are unrivalled, relatively undisturbed, and only slightly metamorphosed Precambrian successions that cover, with only minor hiatuses, the time span from 3,750 m.y. to the Phanerozoic. A wide span of reliable radiometric age determinations, and absence of major facies changes, has led to their formal subdivision into the following erathems: Swazian (3,750+ to 2,870 m.y.), Randian (2,870 to 2,630 m.y.), Vaalian (2,630 to 2,070 m.y.), Mogolian (2,070 to 1,080 m.y.) and Namibian (1,080 to 570 m.y.).

Abstract The geological paradox of at least two Neoproterozoic glacial intervals at tropical latitudes intercalated within carbonates remains an unsolved puzzle. Several conceptual models have been proposed to explain these apparent rapid swings between climatic extremes and the associated isotopic changes in sea-water chemistry. In Oman, post-glacial transgressive sedimentary successions represent important hydrocarbon source rocks. Source rock characteristics of Neoproterozoic post-glacial successions in other parts of the world (even if not directly correlatable) are, therefore, of special economic interest. This paper concentrates on the Ghaub Formation diamictite interval in northern Namibia and the major environmental change in the aftermath of the assumed glaciation. The relationship of the post-glacial sediments with the underlying different types of cap carbonate and diamictite successions is discussed, and a model of the succession of events is presented. The palaeotopography, caused mostly by ongoing tectonic activity including uplift on the scale of thousands of metres, strongly influenced the petroleum system created and played an important role for the hydrocarbon prospectivity of this post-glacial succession. Tectonic activity on the shelf of the southern margin of the Congo Craton was repeated, and different sub-basins were created before, during and after the Ghaub glaciation. The newly formed relief was flooded, and the different sub-basins were affected by restricted circulation for quite some time. This general scenario bears many similarities to the late Ordovician–early Silurian petroleum system, also formed during post-glacial sea-level rise.