Olieboomspoort, South Africa

Olieboomspoort, in the Waterberg Mountains of South Africa, is one of the few rock shelters in the vast interior of southern Africa documenting pulses of occupation from the Acheulean until the end of the Later Stone Age. Revil Mason discovered and excavated the site in 1954 and attributed the large Middle Stone Age (MSA) lithic assemblage to his middle phase of the so-called Pietersburg Industry. Later work at the site lead by Maria van der Ryst focused on the Holocene layers, which preserve abundant archaeological material associated with the final Later Stone Age and the contact period between hunter-gatherers with herders and farmers in the region. In 2018, we initiated new excavations at Olieboomspoort to clarify site formation processes and conduct new analyses on the MSA archaeological material. The MSA deposits contain abundant lithic artifacts and ochre; faunal remains indicate the presence of open grasslands. U-series-ESR estimates on fossil teeth place the deposits within Marine Isotopic Stage 6. Our reappraisal of site formation processes highlights the critical role of water and suggests that the archaeological assemblage is strongly time-averaged.