62 JOHN LYON RICH AND EDWIN A. FILMER 



stream, it is a fair inference that the interglacial interval bore a 

 similar ratio to postglacial time. It would be necessary, however, 

 to take account of possible different gradients of the streams and 

 different cUmatic conditions during the intervals, but the effects of 

 these could hardly lead to the confusion of true interglacial intervals 

 with minor retreats of a fluctuating ice front. 



The conditions outHned in the preceding paragraphs are realized 

 very fully in the Finger Lake valleys. The main troughs, extending 

 approximately in the direction of ice movement, were deeply 

 scoured, while tributary valleys, suffering less erosion, were left 

 hanging. The extent to which hanging valleys were developed 

 has been so well presented in the writings of Tarr and others that 

 it need not be dwelt upOn here. 



If the glacial period in this region was represented by more than 

 one ice invasion, with corresponding intervals of deglaciation, we 

 should expect to find, in at least some of the numerous tributary 

 hanging valleys, old drift-filled gorges representing the work of inter- 

 glacial streams. Such gorges are abundant, though their inter- 

 glacial origin has not, in most cases, been fully demonstrated. They 

 have been described by Matson^ as occurring in the Buttermilk 

 valley, and by Tarr, in the valleys of Watkins Glen, Fall Creek, 

 Six Mile Creek, and others in the neighborhood (see references in 

 later paragraphs). 



In the autumn of 1909 the senior aiithor discovered in the vaUey 

 of Six Mile Creek phenomena which apparently had not been rec- 

 ognized before and which seem to have a distinct and important 

 bearing on the problem of multiple glaciation. During the year 

 1910-11 Mr. Edwin A. Fihner, at the senior author's suggestion, 

 undertook a detailed study of the lower Six Mile Creek valley. The 

 results of this study were embodied in a paper now in manuscript 

 form in the Cornell University Library. The facts brought to 

 light by our investigation of the valley seem worthy of wider pub- 

 licity than is possible for this manuscript. Hence the present joint 

 paper has been prepared by the senior author, who has, however, 

 made free use of Mr. Filmer's material and conclusions. 



' G. C. Matson, "A Contribution to the Study of the Interglacial Gorge Problem," 

 Jour. GeoL, XII (1904), 133-51. 



