ARS | Publication request: Griddlestones from Adak Island, Alaska: Their provenance and the biological origins of organic residues from cooking

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: November 29, 2011
Publication Date: April 19, 2012
Citation: Jeannotte, R., Nicolaysen, K., Dowell, F.E., Johnson, T., West, D. 2012. Griddlestones from Adak Island, Alaska: Their provenance and the biological origins of organic residues from cooking. In: West,D., Hatfield, V., Wilmerding, E., Lefevre, C. and Gualtieri, L. The People Before: The geology, paleoecology and archaelogy of Adak Island, Alaska. Oxford: Archaeopress. 269-287.

Interpretive Summary: We attempted to determine how prehistoric Aleuts used burned stone slabs, historically called griddlestones. These griddlestones were recovered from Adak Island, Aleutian Islands, Alaska. The griddlestones show evidence of fire exposure and have a dark, often greasy, matrix of decomposed organic residues. Petrographic analysis reveals that Aleuts collected most, if not all, of the andesite slabs at a natural outcrop. Stable isotope signatures recovered from the stones were within in the same range as signatures found on the stones collected from the natural quarry, plants, soils and tephras . The isotope signatures found on the griddlestones could be attributed to soils, decaying plants, and/or tephras associated with the archaeological site along with contributions of ‘seafood’ signatures. This could explain the slight enrichment in 13C observed in griddlestones compared to soils, plants and tephras. The analysis of the molecular signatures of the stones by VIS/NIR spectroscopy confirmed the stable isotope data. The sources of the chemical fingerprints on the griddlestones could be multiple.

Technical Abstract: Burned stone slabs, historically called griddlestones, were recovered from Components 1 (2390-2590 RCYPB) and 2 (170-415 RCYBP) at archaeological site ADK-011 on Adak Island, Aleutian Islands, Alaska. The griddlestones show evidence of fire exposure and have a dark, often greasy, matrix of decomposed organic residues. The griddlestones consist of hornblende andesite that cleaves into flat fragments suitable for a cooking platform. It is unclear how prehistoric Aleuts actually used these flat slabs. Petrographic analysis reveals that Aleuts collected most, if not all, of the andesite slabs at a natural outcrop 5km from ADK-011. Stable isotope signatures recovered from the stones (-24.89 ± 0.23) were within in the same range as signatures found on the stones collected from the natural quarry (-25.90), plants (-26.23 ± 0.38), soils (-25.83 ± 0.12) and tephras (-27.20 ± 0.13). The d13C signatures found on the griddlestones could be attributed to soils, decaying plants, and/or tephras associated with the archaeological site along with contributions of ‘seafood’ d13C signatures (-4.03 ± 1.27). This could explain the slight enrichment in 13C observed in griddlestones compared to soils, plants and tephras. The analysis of the molecular signatures of the stones by VIS/NIR spectroscopy confirmed the stable isotope data. The sources of the chemical fingerprints on the griddlestones could be multiple. A more detailed analysis using biomarkers and their compound-specific isotopic ratios will be required to test the hypotheses raised in this chapter