Abstract:
The Kaapvaal Craton hosts a number of Precambrian sedimentary successions which
were deposited between 3105 Ma (Dominion Group) and 1700 Ma (Waterberg
Group) Although younger Precambrian sedimentary sequences outcrop within
southern Africa, they are restricted either to the margins of the Kaapvaal craton, or
are underlain by orogenic belts off the edge of the craton. The basins considered in
this work are those which host the Witwatersrand and Pongola, Ventersdorp,
Transvaal and Waterberg strata. Many of these basins can be considered to have
formed as a response to reactivation along lineaments, which had initially formed by
accretion processes during the amalgamation of the craton during the Mid-Archaean.
Faulting along these lineaments controlled sedimentation either directly by
controlling the basin margins, or indirectly by controlling the sediment source areas.
Other basins are likely to be more controlled by thermal affects associated with
mantle plumes. Accommodation in all these basins may have been generated
primarily by flexural tectonics, in the case of the Witwatersrand, or by a combination
of extensional and thermal subsidence in the case of the Ventersdorp, Transvaal and Waterberg. Wheeler diagrams are constructed to demonstrate stratigraphic
relationships within these basins at the first- and second-order levels of cyclicity, and
can be used to demonstrate the development of accommodation space on the craton
through the Precambrian.
