Heritage Cases

We are applying for an export permit to undertake further cryptotephra dating of samples from Boomplaas (BPA) Cave. We recently identified cryptotephra from the Youngest Toba Tuff (YTT), an eruption dating to 74 ka, at Vleesbaai Area B (VBB) (Smith et al., 2018). With this discovery, we were able to tightly correlate deposits from VBB and Pinnacle Point 5-6, a neighboring site along the coast. The YTT and other younger eruptions have also been successfully identified at various other sites in the region, demonstrating the widespread nature of these deposits throughout South Africa and the potential to use this technique to precisely date and link archaeological sites throughout the region. BPA is an important site to study because it is located along the northern margin of the Little Karoo Basin within a year-round rainfall regime and can provide insight into how environmental change in this rainfall regime may have influenced past populations, specifically during the Middle Stone Age-Later Stone Age transition. The deposits date back to 80 ka; however, the chronology mainly relies on radiocarbon dating which is inconclusive for deposits > 40 ka (Pargeter et al., 2018). Pargeter et al. (2018) redated Boomplaas’ deposits using radiocarbon dating of charcoal assemblages from Hilary Deacon’s excavations, however, this study solely focused on the late Pleistocene deposits. Currently, there is no other dating method establishing the chronology at this site. However, it is suspected that the deposits extend back to 80 ka, if not older, due to the presence of Howieson’s Poort near the base and the extrapolation of the radiocarbon dates (Pargeter et al., 2018). Regardless, there is no other dating method to independently verify these hypotheses. Therefore, for this project, we propose to sample BPA for cryptotephra so we can more accurately place it on a reliable and comparable timeline with surrounding sites. Additionally, we will use cryptotephra to test the current age model that has been established using radiocarbon dating. Samples necessary for this project only consist of sediment. No archaeological material was included. All samples were piece-plotted and recorded. Samples will be analyzed by the Sediment and TEphra Preparation (STEP) Laboratory at Arizona State University (ASU) and the Cryptotephra Laboratory for Archaeological and Geological Research (CLAGR) at the University of Nevada, Las Vegas (UNLV). We are undertaking this project in collaboration with Dr. Eugene Smith, manager of cryptotephra lab at UNLV.