63-1 Modeling Lake Fort Rock’s Late Pleistocene Wetlands using GIS and Optically Stimulated Luminescence Dating in South-Central Oregon

Session: Geoarchaeology of Sites to Landscapes: Current Research on Long-Term Water and Soil Management and Maladaptation (Posters)

Poster Booth No.: 116

Presenting Author:

Spencer Chase

Authors:

Chase, Spencer M¹, Rosencrance, Richard², McDonough, Katelyn³, Smith, Geoff⁴, Rodrigues, Kathleen⁵, Henry, Jason⁶, Pike, Scott H.⁷

(1) Department of Environmental Science, Willamette University, Salem, Oregon, USA, (2) Department of Anthropology, University of Nevada, Reno, Reno, Nevada, USA, (3) Department of Anthropology and Museum of Natural and Cultural History, University of Oregon, Eugene, Oregon, USA, (4) Department of Anthropology, University of Nevada, Reno, Nevada, USA, (5) Division of Earth and Ecosystems Sciences, Desert Research Institute, Reno, Nevada, USA, (6) Department of Environmental Science, Willamette University, Salem, Oregon, USA, (7) Department of Evironmental Science, Willamette University, Salem, Oregon, USA,

Abstract:

The Fort Rock Basin on the northern edge of the Great Basin in south-central Oregon once held a 2,000 square kilometer lake that receded toward the end of the Pleistocene, but its chronology is poorly understood. The lake and wetlands that developed as it receded were important resources for Indigenous people, as seen throughout the 14,200-year-old archaeological record in the region. Determining wetland size, location, and chronology is therefore necessary to properly contextualize the environments at local archaeological sites. We use six previously recorded lake shorelines to model the Lake Fort Rock’s total area, wetland area, and its Wetland Habitat Index value. This work was completed using a LiDAR-derived digital terrain model in GIS. To better constrain shoreline ages, we also present new optically stimulated luminescence dating from the Connley Caves (35LK50), a cluster of eight wave-cut rocker-shelters that overlook Paulina Marsh in the Fort Rock Basin. These methods provide a high-resolution understanding of the lake’s extent and associated wetlands that can be used to better interpret the archaeology of Fort Rock Basin and predict where archaeological sites may be located. 

Geological Society of America Abstracts with Programs. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-10623

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