INTERGLACIAL GORGES 79 



or to overthrow this explanation are not yet at hand it must stand at present 

 merely as a working hypothesis. 



The question of the explanation of the buried gorges by regional 

 rejuvenation is then raised (p. 290). Two sentences in connection 

 with this are quoted: 



Distinct progress toward solution might be made if it were possible to 

 establish the grades of the buried gorges. If they can be shown to have such 

 steep grades as to carry them down to the main valley bottoms the theory of 

 rejuvenation will be greatly strengthened. 



In this connection we again call attention to Fig. 6, showing the 

 projected grade of the rock bottom of the oldest of the buried gorges 

 of Six Mile Creek, which profile, it would seem, does not tend to 

 strengthen the rejuvenation theory. 



As late as 1906 we find the following in regard to the gorges of 

 the Finger Lake valleys :^ 



There are some facts which indicate possible greater complexity of ice 

 erosion, for in some of the vaUeys there is apparently more than one buried 

 gorge; but the evidence on this point is not as yet convincing, and for the pres- 

 ent we can point with certainty to no greater complexity than that of two 

 periods, one the Wisconsin, the other of some one of the earlier ice advances, 

 with which the work of the glacial geologists of the Mississippi VaUey have 

 made us familiar. 



Tarr's latest published conclusions in regard to these buried 

 gorges may be found in the Watkins Glen-Catatonk Folio of the 

 United States Geological Survey, 1909. He concludes that evi- 

 dence of a pre- Wisconsin period of ice erosion "is afforded by the 

 presence of hanging gorges, partly buried in Wisconsin deposits. 

 .... These are evidently interglacial gorges cut in the bottoms of 

 hanging valleys that were left hanging by overdeepening of the main 

 troughs through ice scouring" (p. 117, field edition); and again, 

 p. 224: "We have conclusive evidence here [referring to the buried 

 gorges] of only two advances, but there may have been more." 



Matson {pp. cit.) at an earlier date had described buried gorges 

 in the valley of Buttermilk Creek, near Ithaca, which led him to 

 the conclusion that in that valley there exists a "series of complex 

 gorges which are considered interglacial. The minimum number 

 of epochsof deglaciationistwo; the maximum number, four " 



' R. S. Tarr, "Watkins Glen and Other Gorges of the Finger Lake Region of 

 Central New York," Pop. Sci. Mo. (May, 1906), 387-97. 



