258 CAPE COD GEOLOGY 



On the north side of the Falmouth moraine, at an elevation of about 150 

 feet, on the northwest slope of Bourne Hill, in Sandwich, in the roadside there 

 was exposed in 1916 some 6 feet of clay beneath glacial gravel and the surface 

 till. This clay bed is well up in the morainal ridge and is probably a part of 

 the outwash in front of the Wisconsin ice sheet. 



At Yarmouth railroad station, in the low cut west of the branch track 

 running to Hyannis, there was exposed in 1916 beds of clay in which boulders 

 are either visible or are reported to occur. The section exposed follows : 



Deposits at Yarmouth 



Sandy till with some boulders 4 



Sharp yellowish glacial sand 6 



Brownish boulder clay; larger boulders, 3 feet long 4 



The surface at this point has been traversed by the Wisconsin ice and the 

 top layer beneath the soil corresponds to the general sheet of Wisconsin drift 

 in the Falmouth moraine of the district. 



The bed of till noted above crops out north of the morainal ridge and cannot 

 be far above or below the horizon of the beds of clay that crop out along the 

 coast of the Bay or within half a mile of the coast where the overlying Falmouth 

 moraine is relatively thin or absent. 



Blue clay crops out along the south shore of Cape Cod Bay and is well ex- 

 posed from West Barnstable railway station eastward to the brick-clay pits in 

 a small valley about a mile east of the station. The beds of clay in the pits lie 

 close to the level of high tide. The surface at the railway station stands nearly 

 50 feet above sea level. The beds of clay have evidently been eroded by glaciers 

 since they were deposited. According to statements made to me in 1899 the beds 

 of clay at the brick pits are underlain at one place at a depth of 18 feet by quick- 

 sand and at another place by gravel. The clay contains angular stones, the 

 largest a foot in diameter, and is said to carry large boulders about 4 feet below 

 the surface. In this respect the clay resembles the Montauk till rather than the 

 Gardiners clay. Farther south the clay disappears beneath sand and sandy 

 clay and is well stratified. 



Probably the same bed of clay continues westward along the shore of the 

 Bay and crops out opposite Sandwich, near the old glass works, where formerly 

 bricks also were made. Rolls of clay were struck by workmen digging the eastern 

 part of the Cape Cod Canal and the boulders found below the sand in the district 

 were probably in this clay. These boulders appear to have been dropped from 

 masses of floating ice, if not from glaciers. Such boulders occur in the brick 



