The Late Holocene White River Ash East Eruption and Pre-contact Culture Change in Northwest North America

Abstract

The White River Ash East eruption of A.D. 846-848 blanketed portions of Subarctic Yukon and Northwest Territories, Canada in volcanic ash. This dissertation examines impacts of the eruption on pre-contact hunter-gatherer social relationships. The main bodies of data on which interpretations are based are previously published palaeoenvironmental records, historic records of Indigenous practices, and previously unpublished provenance studies of obsidian (generated through portable X-ray fluorescence, instrumental neutron activation analysis, and laser ablation -inductively coupled plasma-mass spectrometry) and Tertiary Hills Clinker (generated through portable X-ray fluorescence), both of which were used to make pre-contact stone tools. Obsidian and Tertiary Hills Clinker distributions reveal expansive social relationships in the Yukon and Mackenzie river basins that span the Holocene. Changes in raw material distributions after the White River Ash East eruption suggest that some residents in the tephra footprint in the Yukon Basin temporarily abandoned their territories and returned up to a century later with strengthened networks involving kin from southeast Alaska. Residents of the eastern extent of the tephra footprint in Northwest Territories also experienced a disruption to social relationships that may relate to a temporary reliance on kin from the barren grounds east of Mackenzie River. The utilization of hunter-gatherer kinship networks to weather an ecological disturbance promoted new modes of economic exchange and the transfer of technologies, including the spread of the bow and arrow and the intensification of copper use.