2014 GSA Annual Meeting in Vancouver, British Columbia (19–22 October 2014)

Paper No. 12-10
Presentation Time: 10:30 AM

LATEST PLEISTOCENE CLIMATE AMELIORATION ON THE SEWARD PENINSULA OF ALASKA IN ASSOCIATION WITH A BURIED FLUTED POINT COMPLEX


DIPIETRO, Lyndsay, Department of Geology, Baylor University, One Bear Place #97354, Waco, TX 76798, DRIESE, Steven G., Terrestrial Paleoclimatology Research Group, Dept. of Geosciences, Baylor University, One Bear Place #97354, Waco, TX 76798-7354 and GOEBEL, T., Center for the Study of the First Americans, Texas A&M University, College Station, TX 77843

The role of fluted points in Beringian archaeology and the peopling of the Americas has long been debated, largely due to the fact that such artifacts had not been found in a datable context until recently. Excavations at the Serpentine Hot Springs archaeological site on the Seward Peninsula have unearthed a fluted point complex dating to 12-12.4 ka, suggesting that, rather than a precursor to Clovis-type fluted points (as has traditionally been hypothesized), Alaskan fluted points represent a south-to-north dispersal of either people or fluting technology from temperate North America into Alaska. The buried context of the artifacts has allowed not only a refinement of the chronology of Beringian archaeology but also an opportunity to better understand the landscape on which these early Americans were living. The soil profile at the site is developed on granitic colluvium derived from the Late Cretaceous Oonatut Granite and has a moderately well-developed buried soil from which the archaeological materials at the site were recovered. Micromorphological analysis, bulk geochemical mass balance, and x-ray diffraction of the paleosol reveal evidence for warmer, wetter conditions on the Seward Peninsula during the latest Pleistocene than exist at the site today. Base cation loss, feldspar hydrolysis, clay and iron oxide production, incipient spodic development and clay illuviation all characterize the cultural zone of the soil profile and are absent both above and below. The co-occurrence of spodic properties and clay illuviation suggest that this paleosol developed under forest vegetation which transitioned from deciduous (possibly during the Bølling-Allerød) to coniferous (perhaps during the Holocene Thermal Maximum) within the period of pedogenesis. These findings corroborate data from roughly time-equivalent pollen cores in the southern part of the Seward Peninsula. Climate models for this part of Alaska suggest that this transition could require as little as 2-4°C warming above modern mean annual temperature. Habitation of the site occurred during the deciduous forest phase of soil development. These new data support the hypothesis that climate change may be have contributed to the transmission of fluting technology (perhaps accompanied by people) from temperate North America into the Arctic.