Non-Destructive, In Situ Lithic Residue Analysis via FTIR Microspectroscopy: First Results

Summary

Lithic residue analysis is undergoing a methodological shift as analysts introduce new methods designed to improve the objectivity of residue identifications. Fourier-Transform Infrared (FTIR) microspectroscopy has been shown to have tremendous potential in this regard. This method is nondestructive, can provide precise identifications of molecular compounds and minerals, and can be carried out in situ – directly on the residues - without removing them from the stone tools. However, the optical properties of residue materials, such as their absorption coefficients and refraction indices, affect the resulting FTIR spectra, making it difficult to compare them with existing standards. In addition, when residues are thin enough that the beam penetrates through to the underlying stone substrate, the optical properties of the underlying stone affect the resulting spectra. In this paper we present the initial results of a project designed to 1) produce a set of FTIR reflectance spectra standards on 15 common organic and inorganic residue types, and 2) document the changes that appear in the spectra of residues placed on a variety of different stone substrates.

This Resource is Part of the Following Collections

• Society for American Archaeology 81st Annual Meeting, Orlando, FL (2016)   •
• Exploring the Microscale: Advances and Novel Applications of Microscopy for Archaeological Materials

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