Provenancing of silcrete raw materials indicates long-distance transport to Tsodilo Hills, Botswana, during the Middle Stone Age

Lithic artifacts from the African Middle Stone Age (MSA) offer an avenue to explore a range of human behaviors, including mobility, raw material acquisition, trade and exchange. However, to date, in southern Africa it has not been possible to provenance the locations from which commonly used stone materials were acquired prior to transport to archaeological sites. Here we present results of the first investigation to geochemically fingerprint silcrete, a material widely used for tool manufacture across the subcontinent. The study focuses on the provenancing of silcrete artifacts from the MSA of White Paintings Shelter (WPS), Tsodilo Hills, in the Kalahari Desert of northwest Botswana. Our results suggest that: (i) despite having access to local quartz and quartzite at Tsodilo Hills, MSA peoples chose to transport silcrete over 220 km to WPS from sites south of the Okavango Delta; (ii) these sites were preferred to silcrete sources much closer to Tsodilo Hills; (iii) the same source areas were repeatedly used for silcrete supply throughout the 3 m MSA sequence; (iv) during periods of colder, wetter climate, silcrete may have been sourced from unknown, more distant, sites. Our results offer a new provenancing approach for exploring prehistoric behavior at other sites where silcrete is present in the archaeological record.