ENVIRONMENTAL CHANGE AND ARCTIC PALEOINDIANS.

Intensive Paleoindian occupation of the Mesa site occurred between 10,300 and 9700 [sup 14]C yr B.P. Was the timing of this occupation controlled by environmental changes? We investigated stratigraphic records of geomorphology and vegetation to describe how landscapes in the Arctic Foothills changed between 13,000 and 8000 [sup 14]C yr B.P. Paleoindians were present during a time of rapid and sweeping changes in vegetation, slope erosion, floodplain dynamics, permafrost stability, and soil type. We speculate that Paleoindians moved into arctic Alaska to exploit population highs in large ungulates that in turn were triggered by landscape-scale, geomorphic disturbances caused by climate changes. Environmental changes slowed and rising sea levels flooded Alaska's continental shelves during the Early Holocene, causing summer temperatures to fall and precipitation to increase. A more stable climate and the prevalence of maritime air masses allowed the spread of tussock-tundra vegetation, which probably drove both the Paleoindians and their prey species out of the region. [ABSTRACT FROM AUTHOR]