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.

Dr. Thieme studies the stratigraphy of archaeological sites and the history of landscapes that people inhabited in the past. His study of recent sediments along the Susquehanna River contains contributions in geochronology, soil mineralogy, environmental magnetism, and low-temperature geochemistry.