ROCKSHELTERS AS LATE QUATERNARY GEOLOGICAL RECORDS IN THE BIGHORN MOUNTAINS, WYOMING

Rockshelters in Wyoming’s Bighorn Mountains have a long history of archaeological research resulting in a rich dataset of geological and paleoecological information that provides a context for the region’s 12,000 year cultural record. In this study we focus on three deeply stratified and well-dated rockshelters to meet three primary objectives. First, we apply Bayesian statistics to each record to create an age model that contextualizes stratigraphic variability and contrasts autogenic and allogenic sedimentation processes at each site. Second, we correlate the stratigraphic record with a recently published regional temperature and precipitation record that provides a paleoclimatic reconstruction at 50-year intervals spanning the last 13,500 cal years BP. Third, we propose a biogeomorphic process-response model that examines complex linkages between Late Quaternary climatic variability, ecological response, and human foraging behavior. The results of this study complement recent archaeological reconstructions in the Bighorn Basin that demonstrate distinct, long-term relationship between climate conditions and human population densities in this part of the semi-arid Rocky Mountain west.