Very Small Rocks: Exploring Specimen Size Limits in Trace-Element Analysis of Obsidian Flaked Stone with Portable XRF

Summary

This is an abstract from the "SAA 2021: General Sessions" session, at the 86th annual meeting of the Society for American Archaeology.

Archaeologists continue to push the limits of nondestructive X-ray fluorescence (XRF) analysis in efforts to geochemically source small obsidian artifacts. Building on numerous prior investigations, this study examines a statistically large sample of unmodified obsidian flakes to better define the size threshold for acceptable precision and accuracy and to test the use of a source library that includes small samples. Using traditional flintknapping methods, 1,200 flakes were made from three geochemical obsidian sources: Casa Diablo, Bodie Hills, and Buffalo Hills. Specimens ranged from very small pressure flakes to large interior flakes and were intended to replicate the size and morphological variation typical of an archaeological assemblage. The specimens were analyzed on two Bruker handheld pXRF units, the Tracer III-SD and the 5i. Statistical analyses and computing algorithms were used to quantify the size limits of nondestructive analysis and to create source confidence regions that include small samples.

This Resource is Part of the Following Collections

• Society for American Archaeology 86th Annual Meeting, Online (2021)   •
• SAA 2021: General Sessions

Keywords

Spatial Coverage

Record Identifiers

Abstract Id(s): 32431