Molecular Characterization of Pine Pitch on Treated Water Vessels in the Four Corners Region

Summary

This is an abstract from the "SAA 2019: General Sessions" session, at the 84th annual meeting of the Society for American Archaeology.

The use of pitch to coat historic water vessels represents the complex relationships between indigenous peoples and native plants in the American Southwest. Chemical analyses and comparisons were conducted with the intention of sourcing the pitch coating to a specific conifer species. Ponderosa (Pinus ponderosa) and Piñon (Pinus edilus), two species of the Pinecea family, are the most common materials in the region for water vessel application. In order to distinguish these two species and other conifers that could have been used for the sealant, we compared raw materials with samples of pitch coatings taken from historic water vessels and analyzed them via gas chromatography-mass spectrometry (GC-MS). The results allowed us to identify key molecular differences in the 46 pitch samples and identify similarities between the 14 taken from treated baskets. The results of the GC-MS analysis were then compared to eight pitch samples harvested from local trees, to identify past coating processes. The comparisons resulted in the species level identification of the pitch used for treating water vessels in the Four Corners Region. The preliminary results of the GC-MS analysis have led to a consistent molecular footprint for the applied pitch across multiple cultures of the Southwest.

This Resource is Part of the Following Collections

• Society for American Archaeology 84th Annual Meeting, Albuquerque, NM (2019)

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Record Identifiers

Abstract Id(s): 24915