Characterisation of 15 sources of Japanese obsidian: PIXE–PIGME analysis, and identification of archaeological specimens

Tuhinga 29: 77-89

ABSTRACT: Samples of obsidian from 15 different volcanic sources in Kyushu, Honshu and Hokkaido were subjected to analysis using the PIXE–PIGME method. Eighteen elements were resolved for each source, and a series of statistical techniques was used to assess the distinctiveness of the sources. It was found that the sources could be separated into three groups, each with sub-sources that are virtually indistinguishable from each other. The first group of four sources originates in the Shinshu area, the second group of two sources is from the Izu Islands, and the third group contains two sources on Kyushu. Each of these groups is easily distinguished from the others. Finally, nine obsidian artefacts from three archaeological sites were analysed and compared with these sources. Eight of these could be allocated to a source, while one proved to be from an unknown source.

KEYWORDS: Obsidian, Japan, PIXE, PIGME, archaeology, source characterisation.