REPORT OF THE DIRECTOR I919 47 



In 1882 Chamberlin^ notes that his assistant, R. D. Salisbury, 

 " observed a very fine development of the chain (of moraine) in the 

 TuUy (sic.) valley." On the earlier page cited he states that he con- 

 siders all the line of morainic hills, of which the TuUy occurrence 

 is a part, as the terminal moraine " of a very important advance 

 of the great ice-sheet at a date considerably later than the stage of 

 greatest glaciation, or, in other words, to outline the ice limit of a 

 second glacial epoch." It will be noted that this interpretation is 

 at variance with the one given in the preceding section of the present 

 paper, where it is stated that the Tully moraine (and this statement 

 applies equally to other moraines similarly located at the valley 

 heads in the Finger Lakes region) marks, merely, a prolonged halt 

 in the retreat by wasting due to melting and evaporation, of the last 

 advance of the ice which extended at its maximum stage a con- 

 siderable distance south of this line. It is possible that Chamberlin's 

 inference is in so far correct that the Wisconsin Ice, as the last 

 great advance is termed, had two phases, an earlier and a later 

 forward movement, separated by a considerable time interval, and 

 that the second forward thrust did not extend so far to the south 

 as did the first. In that event the line of valley head moraine in the 

 Finger Lakes region may mark the near maximum stand of the ice 

 at the time of the second Wisconsin advance, but the opinion that it 

 was the. actual terminal of this ice does not now find general accep- 

 tance by glacial geologists,^ If it were the actual terminus, extensive 

 deposits of older, more weathered glacial material should occur 

 immediately south of the morainic line, and this has not been 

 observed. Moreover, other notable lines of moraine occur to the 

 north, and the changes in the higher levels of the lake waters that 

 preceded the present Great Lakes indicate that the withdrawal of 

 the ice was, as postulated, by steps, and not a steady progressive 

 melting away. 



The authors of subsequent papers dealing with the effects of 

 glaciation in this part of New York State, who make reference to 

 the Tully area have been so engrossed in the work of tracing the 

 glacial lake history of the region, following up the original suggestion 

 made by the late G. K. Gilbert, that they give only incidental mention 

 to other features. Thus Fairchild * refers to the heavy moraine that 



^ Chamberlin, T. C. The Terminal Moraine of the Second Glacial Epoch, 

 Third Ann. Rep't, U. S. Geol. Sur., 1883, p. 357 and 302. 



*See Tarr, R. S., The Physical Geography of N. Y. State, N. Y. 1902, 

 p. 127-28. 



* Fairchild, H. L., Glacial Waters in the Finger Lakes Region, Bui, Geol. 

 Soc. Amer., 1899, v. 10, p. 57-58. 



