COASTAL DUNE ACTIVATION, STABILIZATION AND CYCLING: THE TAPHONOMY OF STRATIFIED ARCHAEOLOGICAL SITES IN THE MICHIGAN BASIN

Our research is directed at understanding the processes that contribute to the formation and preservation of stratified and buried archaeological sites in coastal dunes, particularly as such formation and preservation relates to the periodic cycling of dune activation and stabilization episodes. In the past few years we have systematically dated deposits of coastal eolian sand, and paleosols contained within them, via OSL and radiocarbon dating respectively, to reconstruct these relationships. Samples were drawn from many sites by deep coring and at others by hand where good vertical exposures occur. These dates were augmented with AMS ages derived from adhering cooking residues from curated ceramics of varying age. Preliminary analyses of these data suggest that geoarchaeological relationships in coastal dunes vary in space and time, with at least four coastal partitions present. In general, intact older sites are more likely to be buried and preserved in the northern part of the basin, whereas they are absent to the south. We discuss the related contributions of isostatic uplift, lake level fluctuation, lakeshore position, and wind direction to this variability.