Micro-residue analysis on early stone age tools from sterkfontein, South Africa: A methodological enquiry

I report here on a micro-residue study of Early Stone Age artefacts from Sterkfontein, South Africa. A total of 33 artefacts was analysed. One part of the sample is attributed to the Oldowan and dates to around two million years ago; another part is attributed to the Acheu-lean industry, dating to around 1.5 million years ago. Previously, the pieces have been shown to hold micro-residues and ancient DNA. However, due to the great age of the samples, it has been questioned whether the micro-residues were use-related. To investigate this, I conducted a micro-residue study on part of the originally analysed sample and on other artefacts with the same provenance; the tools were analysed with a light microscope. Here, I first review the taphonomic history of the samples and second, report on the results of the microresidue analysis. The taphonomic history of the artefacts is complex: biological, mechanical and chemical decay of the organic microresidues would have prevailed in the Sterkfontein setting and it is highly unlikely that micro-residues are preserved. In addition, the recorded micro-residue distributions fail to satisfy a number of basic criteria designed to distinguish use-related residues from microcontaminants. There is also an obvious contaminant signal in the form of brightly coloured remains, pollen and ink. Based on these multiple lines of evidence, it is concluded that the recorded remains are not use-related and the contaminant micro-residues probably originate from post-excavation handling and curation. The previous study focused on single remains, whereas this analysis includes the fidl context of the micro-residues. As a result of the different approach used here, the interpretation of the micro-residues differs.