Research project: Application of Raman spectroscopy to sourcing and identification of microscopic residues for obsidian stone tools
- Start date:
- ARC Discovery Project; Australian Museum
Ancient social networks and trading patterns can be reconstructed by matching obsidian artifacts found at archaeological sites back to their geological sources. A number of geochemical techniques have successfully characterized obsidian tools from Pacific archaeological sites, but most require damage to the artifacts, have restrictive sample requirements, or are very expensive.
The research team is evaluating the potential of Raman spectroscopy (using a number of different instruments including portable Raman) as a relatively quick and non-destructive alternative to conventional methods, especially for large artifacts. Samples are being studied to see how well the spectra can differentiate known geological outcrops of obsidian in Papua New Guinea. Next, the technique will be used to analyze a series of large, fragile obsidian tools now housed in museums in Australia and Europe.
A second project will assess the capability of Raman spectroscopy to identify microscopic residues preserved on stone tools as a by-product of their uses. Raman has a distinct advantage because it can focus the beam size as small as 1µm, less than the size of an individual starch granule or pollen grain. The project will begin with a study of residues created on modern replicas of stone tools used in a range of tasks: e.g. butchering an animal, cutting up vegetables, preparing skins for clothing, scraping wood, sawing shell, etc. Using the Raman spectra from these cases, residues on ancient stone tools from Papua New Guinea will be analyzed to discover their functions.
Dr Robin Torrence , Senior Principal Research Scientist