SUBMERGENCE PHENOMENA 



607 



2. SUMMIT-LEVEL SANDPLAIX8 



Several wave-planed areas of gravel or sand are found at, or verjr 

 near, the marine summit level. These have no relation to any existing 

 rivers and the deposits are evidently glacial: but the waters which gave 

 the level surfaces were not glacial, as they all lie either in or facing 

 seaward drainage. The plains at Sharon and Foxboro stand on the 

 main divide between northward and seaward drainage. The extensive 

 plains of Long Island and Nantucket are regarded as examples at the 

 glacier terminus. The following tabulation gives a few examples seen 

 by the writer. Doubtless other examples will be found. Some descrip- 

 tion is given later. 



Locality. 



Topogrraphic 

 sheet 



Elevation. 



Marine 

 summit. 



Massachusetts 

 Sharon Heights 



Dedham 



280-285 



280-290 



130-135 



40- 80 



240 



280-290 



160-180 



'>95 



Foxhoro 



Dedham-Franklin . 



Gay Head 



Nantucket 



Providence 



Burrillsville 



New London 



990 



Gav Head (smoothing) , . 



155 



Nantucket Island 



Rhode Island 

 "Dugawaj^ Hill," southwest of Provi- 

 dence. 

 Woonsocket 



80 



255 

 290 



200 



Connectlcnt 



"Mile Plain," northwest of New Lon- 

 don. 



3. WATER-LAID DEPOSITS FACiyG THE SEA 



A few surficial and bedded deposits of standing-water origin lie at 

 high levels close to the open sea. l^o one has ventured to attribute 

 them to glacial waters, but they have been credited to submergence pre- 

 vious to the last ice-sheet ; yet they overlie the morainal drift and are thj 

 latest phenomena of the districts. 



Locality 



Topographic 

 sheet. 



Elevation. 



Gay Head, Marthas Vineyard... 



Sankaty Head, Nantucket 



Manomet Hill, east of Plymouth 

 Highland Light, North Truro . . . 

 Mount Desert, Maine 



Gay Head j 120-125 



Nantucket 80 



Plymouth i 230 



Provincetown . . . 120 



Mount Desert . . . 230 



Marine 

 summit. 



155 

 80 

 235 

 190 

 250 



