DELMARVA'S UPLAND LATE PLEISTOCENE GEOARCHAEOLOGICAL RECORD: UNDERSTANDING COASTAL PLAIN TERRESTRIAL CONDITIONS SOUTH OF THE LAURENTIDE ICE SHEET

Multiple eroded shoreline profiles along the eastern margin of the Chesapeake Bay have been analyzed. These profiles are expressive of low sea-stand upland conditions spanning OIS-3 and OIS-2. The profile data illustrate how northern hemisphere climatic variation, isostatic change, and landscape formation processes are expressed within the unglaciated coastal plain south of the Laurentide ice sheet. Five stratigraphic paleosols have revealed detailed information for the intervals dated to ~20,000, ~24,000, ~30,000, ~35,000, and ~42,000 calendar years BP. Plant-macro remains, phytoliths, and pollen for each interval have been established. One locality, containing multiple stratified paleosols, has produced in situ archaeological remains within a buried surface dated to 17,133 ± 88 c14 years BP (20,525 ± 341 calBP). Our research indicates that regional cool late Pleistocene climatic conditions resulted in the long-term preservation of vitrified charcoal. These circumstances inhibit our ability to rectify the “true” antiquity of in situ archaeological remains. In sum, mixed accumulations of vitrified charcoal from merged and/or welded OIS-3 through OIS-2 age paleosols can result in c14 or AMS-age averaging. The age-averaging can also impede our understanding and timing of late Pleistocene upland aeolian events.