Decoding hunter-gatherer-knowledge and selective choice of lithic raw materials during the Middle and Later Stone Age in Eswatini

Reconstructing past movement and mobility patterns requires a landscape-scale approach with knowledge of potential raw material sources and, ideally, multiple archaeological sites. Building on legacy collections in the Lobamba Museum in Eswatini and the identification of primary lithic raw material outcrops through landscape survey, we can provide scenarios of raw material provisioning for hunter-gatherers in Eswatini over the past 40 000 years. We used Neutron Activation Analysis (NAA) to refine the terminology as the three ‘chert’ varieties from the archaeological sites Hlalakahle, Siphiso, Sibebe and Nkambeni are more precisely described as red jasper, green chalcedony and black chert. We were able to identify the primary outcrops for both red jasper and the green chalcedony. Using a least cost path (LCP) analysis together with hydrological and geomorphometric estimates of clast transport in relevant rivers, we reconstructed potential transportation routes of raw material and infer likely provisioning scenarios. During the final Middle Stone Age (MSA), red jasper occurs rarely or is absent in archaeological assemblages, while green chalcedony and other chert variants are frequently observed. This is despite the source of red jasper occurring near the green chalcedony outcrop. During the Later Stone Age (LSA), the red jasper, and a red chert variant of unknown provenance appear more frequently, indicating different raw material provisioning choices. • We successfully traced MSA and LSA chert stone tools to their source in Eswatini using Neutron Activation Analysis. • Green and red chert varieties were transported by hunter gatherers between 20 and up to 100 km distance. • We observed different preferences for raw materials during the LSA compared to the MSA.