Presentation Information
[R6P-08]Development of a Non-Destructive WD-XRF Method for Obsidian Artifacts
*Atsushi KAMEI1 (1. Shimane University)
Keywords:
Obsidian artifacts,WD-XRF,Non-destructive analysis
Obsidian provenance studies play an important role in reconstructing prehistoric human mobility, exchange networks, and cultural interactions. Although non-destructive analytical methods are widely employed, quantitative analysis of artifacts with irregular surfaces remains challenging. In this study, a new wavelength-dispersive X-ray fluorescence (WD-XRF) method was developed for the direct, non-destructive, and automated quantitative analysis of obsidian artifacts with irregular surfaces.Obsidian samples with different chemical compositions were collected from ten source localities in western Japan. Quantitative analyses were performed using the glass-bead method, and polished standard plates were prepared from the same materials. Based on these standards, obsidian-specific calibration curves were established. As a result, a direct analytical method for polished obsidian specimens was achieved, yielding results comparable in accuracy to those obtained by conventional WD-XRF analysis using the glass-bead method. Furthermore, obsidian specimens with artificially generated surface irregularities were prepared, and it was demonstrated that increasing surface roughness decreases both the total concentration of major elements and the measured concentrations of individual elements. Based on this relationship, a correction method was developed to compensate for the effects of surface morphology.Application of the proposed method to Jomon-period obsidian artifacts excavated in Shimane Prefecture demonstrated that corrected chemical compositions can be obtained and directly compared with a high-precision WD-XRF provenance database established using the glass-bead method. The analytical procedure is fully automated and capable of efficiently processing large numbers of artifacts. The proposed method provides a practical framework for linking high-precision geochemical databases with non-destructive artifact analysis and enables large-scale studies of prehistoric exchange and distribution networks based on high-throughput analysis of extensive artifact assemblages.