Border Cave: A 227,000-year-old archive from the southern African interior

Abstract

In 2015, which marked 35 years since Beaumont had worked at the site, we renewed excavations at Border Cave. Our primary aims were to reassess the stratigraphic context of the sedimentary and cultural sequence, gain insight into site formation processes, make a detailed study of organic remains, identify long term cultural trends, and characterize expressions of complex behaviour and innovation. This contribution serves as an update on activities conducted in 2018 and 2019 and provides an overview of our research findings to date, placing them in the broader context of the Middle Stone Age in southern Africa. New luminescence ages based on feldspar grains in the sedimentary sequence are in broad agreement with the previous chronology established for the site. Geoarchaeology and faunal taphonomy have started to elucidate site formation processes, showing that the members should not be considered as homogeneous units, and that associated formation interpretations established by Beaumont are simplifications that are not representative of the diverse site formation processes active in the shelter. This finding is supported by lithic analysis of the Member 2 WA assemblage that shows differences in technology between artefacts from the top, middle, and lower part of the same member. In addition, the lithic artefacts from the middle and lower part of Member 2 WA show continuities with the lithics from the underlying Members 3 BS and 1 RGBS, which were attributed by Beaumont to a different industry. Grass mats/bedding layers are preserved throughout the sequence, the oldest of which dates to ∼200 ka. The use of ash and leaves with insecticidal properties in the bedding construction reflects complex cognition, as does the cooking of starchy rhizomes that come from layers dated to 170 ka. In addition to a rich mammal fauna found in all of the deposits, the remains of a new individual, a 3–4-year-old child, were recovered from Member 1 BS.LR C that has an ESR date of 42.6 ka.