CAPE COD GEOLOGY 317 



Island, and Long Island. Most of the beds are horizontal, and those along 

 the south coast are covered by Wisconsin till, which at some places is 6 feet thick. 

 After a heavy rain in September, 1916, which exposed a section in a gully 

 near the east end of the bluff of the 100-foot hill at the west side of the channel 

 that extends southeastward from the ice-block hole already described, my 

 assistant, Mr. Gilbert Hart, measured the following section: 



Section on the south coast of Nashawena near the middle of the island 



Feet Inches 



Till 4-6 



Sand and clay 6 



Glacial sand containing a layer of pebbles 1 



Clayey sand 3 



Fine sand 5 



Coarse sand 10 



Clay 1 



Coarse sand and gravel 6 



Ferruginous blue clay containing angular pebbles 3 



Sand 3 



Blue clay containing iron concretions 5 



Fine sand 4 



21 10 



The upper clay bed, which carries angular pebbles, appears to be till laid 

 down in the presence of ice, possibly floating ice, and is like a similar bed of 

 pebbly clay in a section of the older Pleistocene deposits on Gay Head. The 

 ferruginuous bands and concretions in the clay are like those in the clay that 

 lies below the Gardiners clay. Exposures of the similar beds of clay were seen 

 at a few places on the northeast coast of the island. 



At the east end of the island, which faces Quick's Hole, there are two , onds 

 of brackish water, which are partly enclosed by bars that have tied a small 

 islet of drift to the main island. 



On the north side of the island a small ridge of bouldery drift projects 

 westward into the sea, forming a small harbor. Two small islets of drift off the 

 point at the west side of the ice-block hole already described appear to be a 

 continuation of this ridge. Between these islets and the peninsula the entrance 

 to the small harbor is obstructed by large boulders, and other boulders stand 

 conspicuously around the northwestern point of the island and about the north- 

 east point, at the entrance to Quick's Hole. 



A small marsh surrounds the ponds at the east end of the island, and the 

 lakelet in the ice-block hole near the middle has been encroached upon by a 



