Heritage Cases

We are applying for an export permit to undertake AMS radiocarbon dating of samples from a site for which preliminary dates exist (see previous SAHRA permit numbers 1279 and 2298 and related final reports). Previous dates provided a broad chronological framework for the full range of the stratigraphic section excavated. We were able to determine that one of the densest archaeological accumulations at KEH-1 took place between 40 ka and 20 ka, a period for which there is no comparable site on the southern coast. This part of the deposit consists of a vertical sequence of hearths, deposited over several thousand years, and an underlying deposit of dense artifact accumulation. Our goal is to develop a comprehensive chronology of this occupational sequence. Samples covered by this permit application are derived from the 2015 and 2016 excavations, during which we plotted and collected more than 3,600 charcoal samples, and more than 2,000 shell fragments. All samples were piece-plotted, photographed, and coded to our master database. In addition, the shell fragment was identified as a small, naturally fragmented piece of shell from a brown mussel (Perna perna). Dates from these samples will be essential to the archaeological interpretation of the site, including accurate contextualization of lithics and other artifacts, and to understanding sedimentation processes. We are choosing to submit a shell fragment because no charcoal was recovered from the shell-rich stratigraphic unit. Samples will be subjected to AMS radiocarbon dating with Abox sample preparation as detailed in (Higham et al., 2014). Two of the samples (numbers 29055 and 25352) have be split into two portions, and each half-sample will be dated by a different laboratory. This will allow us to determine the degree of comparability between two laboratories. One set of these split samples will be sent to the Oxford Radiocarbon Accelerator Unit (ORAU) at Oxford University. ORAU recently demonstrated proficiency in the application of Abox pretreatment methods, and showed the importance of such pretreatment for samples (like ours) that are likely to be older than 28 ka. Dr. Thomas Higham and colleagues have published key work on the Abox method (Higham et al. 2014). The other set of the split samples and the four remaining samples (including the shell fragment) will be submitted to Beta Analytic in the United States. Beta Analytic is also capable of applying the Abox pretreatment if warranted. Beta has a much more rapid processing time, which will allow us to use results in upcoming reports, grant applications, and publications.