54 GLACIAL GRAVELS OF MAINE. 



At lower levels there are some fossils in the raised sand beaches, but I have 

 found none in the coarse gravel and shingle beaches. 



SANDS AND CLAYS. 



Although the areas of denuded rock near the coast suggest that the 

 quantitv of raised beach gravel must be large, yet it is small when com- 

 pared with the broad sheets of sand and clay deposited along the coast 

 while the sea stood at higher levels than now. Only a small portion of 

 these finer sediments can have been derived from the till and rock which 

 were washed away and assorted b}' the ocean. There was not much Avave 

 erosion, except on the most exposed coast, and this was situated so far south 

 that the eroded till must have been carried out to sea and can not have con- 

 tributed much to the marine clays as we find them. The marine clays 

 now exposed on the land are composed chiefly of tlie finer sediments poured 

 into the sea by glacial streams or by swollen rivers. Practically they are 

 marine deltas. 



The facts as to the fossils of the marine beds are so well known that 

 only the briefest reference need be made to them. All writers on the sub- 

 ject agree that about the time of the melting of the latest great ice-sheet of 

 this region the sea stood considerably above its present level, varying from 

 a few feet on Long Island Sound to 500 feet at Montreal. The sediments 

 deposited in the sea after the ice retreated from the St. Lawrence basin are 

 well represented along Lake Champlain, and were there studied at an early 

 date; hence the corresponding deposits of this epoch have been termed 

 Champlain by Hitchcock, Dana, and others. A few j^ears ago a nearly 

 complete skeleton of a walrus was found in marine beds at Portland, and 

 is now preserved in the collections of the Natural History Society of that 

 place. Bones of whales, seals, and moUuscan life characteristic of an icy 

 sea have been found in these beds in great numbers, as was early reported 

 by Jackson, Hitchcock, Dawson, and others. In addition to the marine 

 fossils, it is claimed that certain teeth, now in the Allen Collection at Bruns- 

 wick, were found in the marine clay at Gardiner. These teeth were pro- 

 nounced by several authorities to l^e those of the bison, and on this account 

 Professor Packard, in his "Glacial Phenomena of Labrador and Maine, "^ 

 held that the higher lands were inhabited by the bison at the time the 



' Memoirs of the Boston Society of Natural History, vol. 1, pp. 210-262, Boston, 1866-1869. 



