GLACIAL EROSION IN THE FINGER LAKE REGION 

 OF CENTRAL NEW YORK ^ 



RALPH S. TARR 

 Cornell University, Ithaca, N. Y. 



The origin of the Finger Lake valleys was assigned by Lincoln ^ 

 and by the present writer ^ to glacial erosion upon the evidence of 

 hanging valleys, though this name was not then used. Later rec- 

 ognition of other evidence, notably the steepened lower valley slopes, 

 the smooth, straight valley walls, and the absence of projecting 

 spurs, characteristic of regions of marked glacial erosion, supported 

 this explanation. When, however, quarrying operations revealed an 

 area north of Ithaca in which pre- Wisconsin decay was preserved 

 on the steepened slope of Cayuga valley, it seemed necessary to 

 reconsider the question of the origin of this valley. In a paper pre- 

 senting the newly discovered facts '^ the general question of the 

 origin of the Finger Lake valleys was reconsidered and three 

 hypotheses were proposed as working hypotheses. No attempt was 

 made to establish either of the hypotheses, but the object of the 

 paper, avowedly an unfinished study, was to show that the problem 

 was less simple than formerly believed, and that there were objec- 

 tions to the glacial-erosion theory of sufficient force to warrant a 

 question whether some other theory than glacial erosion might not 

 account for these valleys. The fact that I have been quoted as an 

 opponent of the glacial- erosion theory for these valleys, which has 

 not been the case, is the reason for this preliminary statement. 



One of the three hypotheses considered in my previous paper 

 was stated in the following words : 



A modification of the glacial -erosion theory has been advanced during the 

 progress of the investigation of the problem, and is still being considered. It 

 is as foUovirs: During its first advance the ice deeply eroded the valleys; during 



1 Published by permission of the Director of the U. S. Geological Survey. 



2 American Journal of Science, Vol. XLIV (1892), pp. 290-301. 



3 Bulletin of the Geological Society of America, Vol. V (1894), pp. 339-56. 

 ^American Geologist, Vol. XXXIII (1904), pp. 271-91. 



