The movement of obsidian in Subarctic Canada: Holocene social relationships and human responses to a large-scale volcanic eruption

•Subarctic hunter-gatherers used exotic obsidian through the Holocene.•Historical networks of coastal-interior exchange existed for millennia.•A large-scale volcanic eruption caused a temporary displacement of hunter-gatherers.•Existing kin and exchange networks influenced responses to ecological disturbances.•Disturbances stimulated developments including bow and arrow transmission. Lithic provenance analyses offer means to reconstruct ancestral social relationships in Subarctic North America. We summarize sourced obsidian data from 462 archaeological sites in the Yukon and Northwest Territories, Canada, and interpret obsidian distribution through the Holocene with particular attention to the volcanic White River Ash East event of A.D. 846–848. We argue that social mechanisms explain overlapping occurrences of exotic and local obsidians and that the volcanic ash fall triggered changes to obsidian exchange patterns. Following the volcanic event, obsidian from British Columbia moved north into the Yukon with higher frequency. Instead of a population replacement, persistent patterns in the distribution of some obsidian source groups suggest that the ash temporarily pushed some Yukon First Nations south where they strengthened networks of exchange that were retained upon their return. The short-term displacement may also have facilitated the movement of bow and arrow technology into the Yukon, which appears concurrent with the volcanic event. The large-scale eruption had the potential to sever connections between a small group of ancestral Dene (Athapaskans) and their homeland, which culminated in a continent-wide migration in the Late Holocene.