Western Oneota obsidian : Sources and implications

Exotic lithic raw materials provide insight into exchange relations and mobility of prehistoric populations. Toward this end, obsidian flakes from two western Oneota sites, Warne in north central Kansas and Blood Run in northwestern Iowa, were sourced using x-ray fluorescence spectrometry. With the exception of two artifacts from Warne, all were traced to parent obsidian sources in the northwestern Plains and Plateau regions. Obsidian pieces from Warne compare favorably with geologic samples from Malad. Idaho (n=4) and Obsidian Ridge, New Mexico (n=2). Trace element composition in the Blood Run flakes is congruent with sourced standards from Obsidian Cliff, Wyoming (n=5) and Bear Gulch, Idaho (n=1). The artifacts from Warne point to down-the-line acquisition during contact with groups closer to their sources to the west and south. Such contact may have occurred during bison hunting forays in those directions. The low incidence of New Mexico obsidian supports the Late Prehistoric temporal placement of the White Rock phase. The sources of obsidian from Blood Run are consistent with those of artifacts from earlier sites in lowa, particularly those of the Middle Woodland period, and reflect the maintenance of trade relations with northern Plains groups.