478 J. W. SPENCER PRE-GLACIAL HANGING VALLEYS 



J. S. Newbury, who, to some extent, modified this view by his recognition 

 of a buried channel under Lake Erie at Cleveland. 



Discussion concerning the Finger Lakes 



At this stage my studies bearing on the origin of the basins of the 

 Great Lakes were begun by investigations of the buried valleys and sub- 

 merged escarpments. For this work I was inspired by Prof. J. P. Lesley, 

 whose interest was aroused by observations of my own, which he urged 

 should be published at once.^ Even without the cause of the barrier to 

 the Ontario basin being discovered, he considered that the facts, then 

 made known, "disembarrassed us of the chief difficulty of our best pre- 

 served water system of the North,^^ * and gave the coup de grace to the 

 belief in the glacial origin of our lake basins. Nor was he alone of this 

 opinion, for Prof. James Geikie then wrote : "I have always had misgiv- 

 ings as to the glacial erosion of the Great Lakes. . . . Possibly those 

 who have upheld that view will now give in. Your facts seem to me, at 

 least, very convincing. I never could understand how those Great Lakes 

 of yours could have been ground out of ice." 



My first acquaintance with Mr. G. K. Gilbert was when he wrote con- 

 cerning this first publication, saying : "The problem of the origin of the 

 basin of the Great Lakes has always had a great attraction for me. Had 

 I been able to understand its solution, my working h3'pothesis would 

 have been that which you have demonstrated so thoroughly. . . . The 

 matter has certainly never received a demonstration until your paper 

 appeared," etcetera. 



Several years elapsed before substantial progress was made by my 

 showing that the rock barrier, in addition to the drift obstruction, was 

 due to the post-Glacial warping of the region, and that the pre-Glacial 

 outlet of Lake Huron was through Georgian Bay and a now buried valley 

 into the Ontario basin ;^ also that there is a buried pre-Glacial channel 

 between the Erie and the Ontario basins sufficiently deep to have drained 

 the upper basin. ^ As the result of all these discoveries, Prof. T. G. 

 Bonney has declared the researches epoch-making. Nevertheless, one or 

 two, notably Prof. E. S. Tarr, attempted to revive the ancient faith in 

 glacial erosion of lake basins. 



At first Professor Tarr argued against ice erosion," but the following 



aProc. American Phil. Soc, vol. 19, 1881, pp. 300-337. 

 * Rept. Q4, Geol. Surv. Pennsylvania, 1881, pp. 357-404. 

 5 Proc. American Asso. Adv. Sci., Cleveland Meeting, 1888. 



« "Evolution of the Falls of Niagara." Geol. Surv. Canada. 1907, chapters 35-37. 

 Here are also given references to the original publications. 

 ''American Geologist, vol. 12, 1893, pp. 147-152. 



