BUFFALO SOCIETY OF NATURAL SCIENCES 



73 



were successively exposed. These levels were lower than the 

 divide between the Allegheny and Lake Erie and the waters were 

 thus cut off from the Allegheny drainage and drained southwest- 

 ward between the icefront and the divide. The successive 

 lowering of the outlet was gradual with numerous stands which 

 have been marked especially in the valley of the Cattaraugus by 

 numerous wave formed plains, deltas and waterlevels. At 

 Gowanda the series is as follows: (Fairchild) 



Highest, southeast of Gowanda, 1210 feet. 



Studley, south of Gowanda, 1032 feet. 



Broadway, south of Gowanda, 972 feet. 



Asylum level, north of Gowanda, 883 feet. 



Collins plain, north of Gowanda, 855 feet. 



The Four Mile level, west of Gowanda, 820 feet. 



/"0/V7Xft/0. 



A/£IA/ YOM 



P£N/VS YL M/V/s4 



Fig. 38. The approximate extent of Lake Whittlesey, and its outlet to the 

 westward. The shores of Lake Whittlesey are indicated by heavy 

 lines, those of our present lakes by faint, dotted lines. 



The lakes which formed these levels seem to have drained 

 westward across northern Ohio and southern Michigan, thence 

 southward to the Mississippi. Of these the last, in which was 

 laid down the delta now known as the Four Mile level, has 

 received the name of Lake Whittlesey. This can be traced by 

 means of its beaches from the Pennsylvania line to Marilla. 



