Mwulu’s Cave, South Africa

Mwulu’s Cave is located on the eastern escarpment of the Makapansberg Mountains in the district of Mokopane (Limpopo Province, South Africa, 24.17° S, 29.24° E), close to the Makapan Valley. The area hosts several well-known Plio-Pleistocene sites (Fig. 1). The cave is accessed directly from a mountain pass, informally and locally called the ‘Monkey Nek’. The site lies in the middle beds of the Late Archaean and Early Proterozoic quartzites of the Black Reef Formation, which are considered the basal lithostratigraphic unit of the Transvaal Supergroup exposed around the margins of the Transvaal basin (Eriksson et al., 1995; Els et al., 1995). The heavily fractured, south-west tilted Black Reef Formation quartzites represent the highest points of this landscape, c. 2040 m above sea level, exposed as a scarp following the erosion of the overlying dolomites. It is in these dramatic cliffs overlooking the Springbok Flats (500 m below) that Mwulu’s Cave formed. Mwulu’s Cave is located 30 m below a north facing overhanging quartzite ledge, and about 15 m above the base of the scarp. The small, narrow, tapering cave (about 10 m long and 3 m wide at its entrance) opens 5 m below a compound fracture that splits into two diverging joints above the roof of the cave. It is most likely that the cave formed through localised collapse of the cliff face as a result of the development and exposure of this fracture complex.