Trace Element Composition of Obsidian Butte, Imperial County, California

Abstract

Non-destructive energy dispersive x-ray fluorescence analyses were performed on rhyolitic volcanic glass (obsidian) from Obsidian Butte, located at the south end of the Salton Sea in Imperial County, California. Sixteen trace and rare earth element concentrations were measured in parts per million (ppm), and these values compared favorably with analyses employing destructive techniques. The results of the present study demonstrate that archaeological artifacts can be matched reliably to the Obsidian Butte source on the basis of non-destructive quantitative analysis, facilitating the study of prehistoric Southern California obsidian trade and interlaboratory comparison of analytical results.