Archaeological significance and chemical characterization of the obsidian source in Kirigamine, central Japan: Methodology for provenance analysis of obsidian artefacts using XRF and LA–ICP–MS

The Kirigamine area is one of the major obsidian sources in the Chubu-kanto region of central Japan, and is regarded as an important archaeological study area for improving the understanding of historical changes in human–environment interactions related to obsidian procurement activities during the Upper Paleolithic. Previous studies have presented a model for the relationship between human activities and the paleoenvironment, but there is a need for further understanding based on data related to the sourcing of obsidian in the Kirigamine area. This study aimed to establish a method for provenance analysis of obsidian artefacts based on chemical compositions. The chemical compositions of 13 groups of obsidian sources in the Kirigamine area were determined by WDXRF and LA–ICP–MS analyses, and discrimination diagrams proposed. For verification purposes, provenance analyses of obsidian artefacts excavated at the Hiroppara prehistoric site were undertaken using these discrimination diagrams. We yielded the same results of provenance analysis among the WDXRF and LA–ICP–MS methods, and the discrimination methods described may be applied to further provenance analysis of obsidian artefacts using nondestructive EDXRF and pXRF, and micro-destructive LA–ICP–MS analyses.