Heritage Cases

Background Test excavations were undertaken by Mallen at the Buterix 1 site (Mallen & Pearce 2012). Three test squares were opened in different parts of the site. The purpose of the initial excavation was to investigate contact between hunter-gatherer populations and incoming groups. The rock art in the site contains considerable amounts of imagery indicative of contact suggesting that the site was suitable for this purpose. The excavation revealed no evidence of contact and appeared to be purely LSA. No further analysis was undertaken as it did not further the aims of the project. In 2023 the lithic assemblage was analysed by Dr Guillemard. Now that this analysis is complete, publication of the excavated material is possible. The analysis has indicated contexts that are most useful to date to provide a coherent overall chronology for the excavated component of the site. Aim It is critical that all excavated sites be thoroughly dated. It is therefore necessary to date the excavations at Buterix 1. Stratigraphy is not consistent amongst the three excavated squares. Dates are therefore required from each square. Contexts which contain the most significant lithic assemblages and that have the greatest potential to contribute to the overall chronology of the excavation are chosen for dating. Methods Relatively large quantities of charcoal were found throughout the excavation, particularly in square B3. Numerous samples specifically for radiocarbon dating were collected during the excavation. A subset of these has been selected for radiocarbon dating to best date contexts which contain the most significant lithic assemblages and that have the greatest potential to contribute to the overall chronology of the excavation. There is no functioning radiocarbon facility in South Africa, so it will be necessary to export the samples for analysis. This will require an export permit from SAHRA. It is intended to submit the samples to the Center for Applied Isotope Studies (CAIS) at the University of Georgia, USA (Radiocarbon Dating by AMS « Center for Applied Isotope Studies (CAIS) (uga.edu)). They provide a reliable, high-quality analytical service. Once a destruction permit is issued by ECPHRA and an export permit issued by SAHRA, the charcoal samples will be couriered to CAIS for AMS radiocarbon dating. They will use their standard preparation protocols (see https://cais.uga.edu/service/radiocarbon-dating-by-ams/ for details) in processing the sample. The technique is destructive, and it is not expected that any material will be returned. According to the lab, results should be available within 2–3 weeks of submission. The radiocarbon determinations, once available, will be calibrated with OxCal software (Bronk Ramsey 2009) and the SHCal20 calibration curve (Hogg et al. 2020). Confirmation by repository Analysis of the assemblage is not yet complete, and the material has therefore not yet been deposited with the designated repository. They will not accept the bulk, unsorted fine fraction material. Sorting of this material is still underway. It is anticipated that the material will be deposited in 2024. Seeing as the material has not yet been deposited in the repository institution, a letter from the repository cannot be provided. The material is in the interim in the care of the Rock Art Research Institute, University of the Witwatersrand, pending finalisation of analysis ahead of deposit in the repository. References Bronk Ramsey, C. 2009. Bayesian analysis of radiocarbon dates. Radiocarbon 51:337–360. Hogg, A. G., Heaton, T. J., Hua, Q., Palmer, J. G., Turney, C. S. M., Southon, J., Bayliss, A., Blackwell, P. G., Boswijk, G., Bronk Ramsey, C., Pearson, C., Petchey, F., Reimer, P., Reimer, R. and Wacker, L. 2020. SHCal20 southern hemisphere calibration, 0–55,000 years cal BP. Radiocarbon 62(4):759–778. Mallen, L. R. and Pearce, D. G. 2012. First interim report on excavations at Buterix 1, Maclear District, Eastern Cape Province, South Africa. Unpublished report, Rock Art Research Institute, University of the Witwatersrand, Johannesburg.