THE TECTONIC EVOLUTION OF SOUTHERN AFRICA - AN OVERVIEW

This paper provides an overview of recent ideas concerning the tectonic framework and evolution of the southern African subcontinent from the Early Archaean to the present. Mid-Archaean crustal growth of ancient continental fragments resulted from episodic terrane accretion, a process that culminated in the juxtaposition of the Kaapvaal and Zimbabwe granitoid-greenstone terranes during the Limpopo orogeny at approximately 2.7 Ga. Whilst intracratonic sedimentary basins developed on this stable cratonic block from the late Archaean to Mid-Proterozoic (3.0-2.4 Ga), crustal growth occurred during the successive Eburnian (approximately 2.0-1.7 Ga), Kibaran (approximately 1.2-1.0 Ga) and Pan-African (approximately 500 Ma) global accretionary events. The Palaeozoic evolution of southern Africa following the assembly of the Gondwana supercontinent is dominated by the development of the Cape and Karoo basins and their subsequent inversion to produce the Cape Fold Belt (approximately 280-230 Ma). Mesozoic fragmentation of Gondwana (approximately 180-130 Ma) was associated with continental rift volcanism and fault reactivation. Minor tectonic activity continues to the present day.