DROWNED ARCHEOLOGICAL SITE POTENTIAL IN THE WESTERN GULF OF MAINE: AN EXAMPLE FROM BASS HARBOR, ME

Because of its relatively late deglaciation and subsequent isostatic adjustments, the Gulf of Maine was earlier believed to have had limited subaerial exposure and potential for submerged archeological sites. Recent detailed bathymetric and seismic reflection profiles and accompanying vibracores from outer Bass Harbor, ME contradict earlier assumption and demonstrate that the Gulf of Maine has great potential to host drowned sites. In Bass harbor, multibeam bathymetry shows two moraines that were eroded to supply spits. The moraine-spit system formed a lake/estuary basin that was sheltered from complete erosion by nearby islands. Scallop draggers recovered mid-Archaic artifacts from a ridge which cores reveal to be a paleo-spit. Numerous in situ Crassostrea and Mya shells and Zostera stems date the estuary to between 7.8-9.2 (cal.) ka. Several factors led to excellent preservation of drowned habitats and artifacts here and probably elsewhere in the Gulf of Maine: 1) irregular bedrock and glacial outcrops create many basins capable of supporting lakes and wetlands at times of lower sea levels; 2) the bedrock sheltered many locations from exposure to erosive waves; 3) local, relative sea-level experienced a “slowstand” between 11.5 ka (cal) and 7.5 ka during which it only rose from about -23 m to -19 m depth. This slow rise in sea level thoroughly reworked glacial deposits and built spits and other coastal features. These, in turn, formed and protected freshwater wetlands and later estuarine settings that focused human activity. Clearly, a time of stable sea level is conducive to constructing coastal environments and preserving them along with associated artifacts.