Donald Thieme

New Land in an Old Valley: a Stratigraphic and Chronometric Investigation of Holocene Alluvium from the North Branch of the Susquehanna River Donald Thieme

Based upon nearly a decade of fieldwork on archaeological sites, the author proposes a stratigraphic model for Holocene alluvium in an incised bedrock valley of the Appalachian mountains. Buried soils are described and used to trace sediment layers through 23 stratigraphic sections. Analyses of grain size, soil chemistry, clay mineralogy, and magnetic susceptibility are performed on soil and sediment samples. Petrographic examination of thin sections is also used, particularly to characterize the buried soils. A total of 139 radiocarbon dates constrain the age of bounding surfaces within the stratigraphic framework, and these bounding surfaces are found to result from environmental changes which are evident in independent records from the surrounding region.