Heritage Cases

Tswalu was visited in August 2017 and contains a stratified Stone Age occupation in a calcrete pan called Witberg 1, which Beaumont and Bednarik (2015) described as ESA. Witberg 1 is a 5m deep chalky calcrete quarry currently being used as a materials dump near the Tswalu workshop. Two 2-week field excavation seasons have been completed - one in July 2018 and one in January 2019. Control points at Witberg 1 were established with 30cm metal rods driven into secure locations across the quarry, and their location obtained using high-precision RTK DGPS to be on the WGS84 UTM grid in zone 34. The formation history of the pan requires accurate, high-resolution dating to securely reconstruct. This permit is to collect a total of 12 OSL samples from the high-density archaeological horizon, including directly the quartzite artefacts. Dating the artefacts is a destructive process involving drilling 1cm cores through the artefacts. The artefacts chosen for this analysis would be common to the assemblage, and is part of an extremely high-density large open-air occupation of which we have only excavated a small portion (~50cm x 2m). The samples will be exported to Dr Luke Gliganic at the University of Innsbruck, Austria, who will then be in control of the sampling and analysis of the OSL samples. Gliganic is an expert in OSL dating, and has worked at numerous other archaeological sites in East Africa and South Africa (Gliganic et al. 2012; 2014; 2016). Sampling the artefacts and obtaining OSL ages from Witberg 1 in association with carbonate features provides a unique opportunity to link a stratified, open-air Stone Age site in the southern Kalahari Basin with paleoenvironmental data. These excavations and analyses will be able to contribute data towards answering the question of how changing environments impacted early modern human behaviours and evolution in southern Africa.