Identifying Long-Distance Transport of Obsidian Across the North American Landscape in Antiquity Based on Indigenous-led Research Initiatives

Indigenous oral history and archaeological evidence both support extensive long-distance trade and exchange networks in ancient North America. However, many Indigenous communities oppose the excavation, decontextualization, and analysis of their belongings (artifacts) and ancestral remains for documenting such activities for Rights and Title applications. In partnership with xʷməθkʷəy̓əm (Musqueam), an Indigenous community in modern-day Vancouver, BC, we are identifying ways by which previously-excavated materials can be analysed to support community-led research initiatives. In this study, we investigate the geographic origins of 14 small (<1cm in length) fragments of lithic material ('micro-belongings') exhumed from c̓əsnaʔəm (Marpole), a key xʷməθkʷəy̓əm village site. Due to the small size of the micro-belongings, their morphology alone provides little archaeological information. After non-destructive analysis of the glass fragments with Raman spectroscopy, 13 were shown to be composed of at least two varieties of obsidian, and the remaining lithic fragment was shown to be composed of fine-grained volcanic material. The community requested further investigation of source affiliations for the micro-belongings and granted permission for minimally-invasive split stream - inductively coupled plasma - mass spectrometry (SS-LA-ICP-MS) analyses to measure their trace element concentrations and Pb isotopic compositions. A comparison of their measured characteristics with those of potential geologic sources indicates that four of the fragments most likely originated at Browns Bench, an obsidian source in southern Idaho, ~1000 km southeast of c̓əsnaʔəm. The remainder of the fragments most likely originate from Glass Buttes (OR), a large obsidian source ~670 km south-southeast of c̓əsnaʔəm. The other lithic fragment composed of fine-grained volcanic material is likely also from a volcanic centre within the High Cascades or Garibaldi Belt. Such long-distance transport of obsidian in antiquity supports the oral history and continuity of complex xʷməθkʷəy̓əm social and material networks, which still exist today, and provides key additional lines of evidence for how and from where ancient people procured resources in North America.