THE PLEISTOCENE OR GLACIAL PERIOD 885 



At about the same time the sea stood higher than now relative to 

 the land on the coast of Maine, where marine shells occur up to ele- 

 vations of 200 feet or more, 1 and to still greater heights farther north. 



The Loess 



The term loess is used both as a textural and a formational name. 

 Lithologically, it is a silt intermediate between sand and clay. It 

 is generally free from stones of all sorts, except the concretions 



Fig. 590. Map of the extinct Lake Agassiz, and other glacial lakes. Lake 

 Winnipeg occupies a part of the basin of Lake Agassiz. (U. S. Geol. 

 Surv.) 



developed in it since its deposition. In the exceptional cases where 

 stones occur in it, they are confined to its very bottom, or are found 

 in loess which has slumped or been washed down from its original 

 position. It is sometimes interstratified with sand, especially at its 

 base where it is thick. On slopes and at their bases loess is of- 

 ten mingled with slope wash, talus, etc. 



1 Dana, Manual of Geology, 4th ed., p. 982; and Stone, Jour. Geol., Vol. 

 I, pp. 246-254, and Bastin, Rockland, Me. folio, U. S. Geol. Surv. 



