Discovery of Middle Pleistocene fossil and stone tool-bearing deposits at Groot Kloof, Ghaap escarpment, Northern Cape province

WE REPORT THE DISCOVERY OF A MAJOR fossil-bearing and archaeological complex of karstic deposits at Groot Kloof in the escarpment of the Ghaap Plateau, around 100 km southwest of Taung. The region is known for open fluvial and lacustrine sites sampling Lower and Middle Pleistocene tool types and the long, but discontinuous sequence of Wonderwerk Cave. Research at Groot Kloof has concentrated on two of four localities. One locality has yielded fossils from the Florisian Land Mammal Age and lithics that may sample a late Early Stone Age/early Middle Stone Age type industry. The second locality has been dated using U-Th to 248 ± 37 kyr ago for fossil-bearing tufa, and normal magnetic polarity for various tufa and breccia. The occurrence of fossils embedded within tufa rather than infilling a cavity is unusual. Small pockets of Later Stone Age artefact-bearing breccia and rock art also occur. The significance of Groot Kloof is underscored by current debate about the emergence of modern humans in which the appearance of modern behaviour is posited to have occurred in this and other regions during this part of the Middle Pleistocene.