glacial topography that was submerged during the time of clay 

 deposition. The clay is not encountered at one particular eleva- 

 tion, but rather resembles a cloth draped over an uneven surface. 

 Clay horizons in the local area vary from 40 feet above sea level 

 to 60 feet below sea level. 



9. During the subsequent low stand of the sea, this glaciomarine clay 

 was exposed to subaerial conditions and a weathered horizon con- 

 sisting of weathered clay and coarse clastic material eroded from 

 nearby Pleistocene topography. In addition, fresh-water vegetation 

 in areas beyond tidal waters developed a fresh-water peat. An 

 approximate time frame for this low stand of the sea is about 

 10,000 B.P. (Kaye and Barghoorn, 1964). 



10. As sea level rose relative to the land, estuarine and marsh sedi- 

 ments accumulated behind a landward migrating barrier. Drumlins 

 were eroded, some so much that they are barely distinguishable 

 today. Finally the sea-level rise leveled off to its current rate 

 of 0.3 feet per century (Mclntire and Morgan, 1963), and the barriers 

 became anchored against both buried and exposed Pleistocene deposits. 



58 



