Building a selection-based model to explain the spatial and temporal distribution of obsidian artifacts in the northern Great Basin

Summary

This is an abstract from the "SAA 2024: Individual Abstracts" session, at the 89th annual meeting of the Society for American Archaeology.

Over 20 archaeologically-identified obsidian sources occur as inter-bedded surface exposures and stream-transported alluvial deposits within and along the margins of Idaho’s Snake River Plain. Previous research has documented the differential frequency of source use through time and variation in material transport distance for southern Idaho obsidians, implying preferential, but as yet unidentified choice criteria were used by toolmakers. The temporal and spatial variability of obsidian use and the observation of discrete, performance-linked material properties meets expectations for a selection-based model framework to explain this distribution. In particular, we find that use-linked performance attributes such as predictability of cleavage/fracture pattern, fractal function and intra-source coefficient of variation support selection-driven explanations of material choice and use. As prehistoric identification and cataloging of the source universe increased, obsidians were preferentially chosen for material properties like predictability, and variance reduction in manufacture and use costs, over notional characteristics like material hardness, luster or ‘workability.’ Distribution of ‘high-use’ obsidian suggests a selection-based ‘inertia’ existed for these materials, and that the trend of archaeological obsidian utilization supports the observed temporal reduction of source variability and greater spatial distribution in sources predicted to have high inertia, measured by material properties and performance characteristics.

This Resource is Part of the Following Collections

• SAA 2024: Individual Abstracts   •
• Society for American Archaeology 89th Annual Meeting, New Orleans, LA (2024)

Keywords

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Record Identifiers

Abstract Id(s): 40446.0