GEOARCHAEOLOGICAL SETTING OF THE SEBASTICOOK LAKE FISH WEIR, NEWPORT, MAINE

The Sebasticook Lake fish weir is located on the northeastern shore of Sebasticook Lake on an inlet of the East Branch of the Sebasticook River. The Sebasticook River is within the major Kennebec River drainage system of Central Maine. The weir is not a single structure, but rather a complex of emplaced wooden stakes, representing several periods of use. Anoxic conditions of the inlet environment have preserved organic material and artifacts, making the site unusual in Northeastern prehistory. Radiocarbon dates of the weir stakes suggest use of the weir between 5820-1760 BP (Late Archaic-Early Woodland period), making it one of the oldest dated fish weirs in North America. The earliest dates may be controlled more by preservation and lake-level change than by cultural use. Preliminary geophysical investigations of the Sebasticook Lake basin revealed several submerged, wave-eroded terraces, interpreted as evidence of a lake-level lowstand 8-10 m below present. As a continuation of this initial survey, this project has two goals. First, we are using a full suite of geophysical equipment (seismic reflection profiling, sidescan sonar, and ground-penetrating radar (GPR)) and a comprehensive coring survey of the lake basin, to investigate the location, nature and depth of the paleo-shorelines. This work is intended to determine the cause of lake-level change: glacio-isostatic rebound, climate, or a combination of both. Second, a more detailed GPR survey of the site proper allows a clearer understanding of site-formation processes and the relationship between lake-level change and utilization of the fish weir. The results of this research have direct bearing on our understanding of prehistoric occupation of the Northeast and how human populations lived in and had influence on a dynamic landscape.