Our assessment of lithic residue preservation in varied burial conditions at Star Carr and Manor Farm has demonstrated and emphasised the complexities of residue identification. As stated by Monnier et al. (2012), it is important that residue researchers acknowledge the limitations of their microscopic observations and report cases where identification of particular residues is ambiguous or problematic. Residue analysts need to demystify how microscopic residue determinations are reached and provide convincing evidence (Grace 1996, 216), with publication of both positive and negative results. This may mean taking a more conservative approach to residue identification, and thus to the interpretation of archaeological residues.
Residue analysis of microscopic and chemical deposits on stone tools is an emerging sub-discipline within archaeology, and the unambiguous identification and differentiation of residues is still an ongoing methodological concern. This issue needs to be examined since reliable discrimination of ancient anthropogenic lithic residues from natural and modern contaminants begins with accurate identification. Residue analysts are continuing to improve the accuracy and specificity of their identifications, particularly with the wider availability of new analytical technologies and more frequent collaborations with chemists, physicists, biologists, and material scientists. Once suspected anthropogenic residues on a stone tool are accurately identified, determining their relationship with any visible usewear, distribution on the tool, and ideally their absence from the soil where the artefact was recovered, would all help further establish that the residues are present as a result of the actions of ancient people.
This experiment contributed new knowledge about residue preservation in acidic peat and slightly acidic clay archaeological burial environments, and in a chalky alkaline non-archaeological burial environment. Our results indicate that the identification of microscopic lithic residues is not free of complications. The assessment of the extent of characterisation achievable for twelve residue types resulted in a visual characterisation guide for microscopic residues with diagnostic, distinctive, and non-distinctive categories. In addition, we compared of the benefits of two microscopic imaging technologies for in situ analysis of lithic residues: reflected VLM and variable pressure SEM, showing that using SEM can improve visual characterisation in some cases.
Internet Archaeology is an open access journal. Except where otherwise noted, content from this work may be used under the terms of the Creative Commons Attribution 3.0 (CC BY) Unported licence, which permits unrestricted use, distribution, and reproduction in any medium, provided that attribution to the author(s), the title of the work, the Internet Archaeology journal and the relevant URL/DOI are given.