Before and After Mazama at the Billy Big Spring Site: Landscape Evolution during Altithermal Times and Reoccupation after the Eruption

Summary

How did the ash fall from the Mount Mazama eruption (7682–7584 cal. yr BP (Egan et al. 2015)) affect the people on the Northwestern Plains who experienced it? Data from 24GL304 (the Billy Big Spring Site) in northcentral Montana is used to investigate this question. Excavations conducted in 1952, 1954, 1971 by Thomas Kehoe and in 2016 by our team all found extensive Middle and Late Plains Archaic deposits, but in 2016 we discovered a ~10 cm thick layer of ash from this eruption. This poster addresses four research questions through the lens of geomorphology and soil science: (1) How did the landscape evolve before and after the Mazama ash fall? (2) How did the paleoenvironment evolve after the eruption? (3) How does this landscape setting correspond to what archaeologists know about the Altithermal (9,400 – 6,000 cal. yr BP (Barnosky 1989)) on the Northwestern Plains? (4) How long did it take for people to reoccupy this site after it was covered with Mazama ash, and what did this occupation look like? Archaeologists have long hypothesized about the impacts of the Altithermal on the Northwestern Plains, and I hope to contribute to this discussion with data from these recent excavations.

This Resource is Part of the Following Collections

• Society for American Archaeology 82nd Annual Meeting, Vancouver, BC (2017)

Keywords

Spatial Coverage

Record Identifiers

Abstract Id(s): 17088