76 JOHN LYON RICH AND EDWIN A. FILMER 



To return to a consideration of the second question, namely, 

 whether the 600-foot gorge may not be a product of preglacial 

 rejuvenation, we have seen that lower Six Mile Creek valley was 

 profoundly deepened and modified by ice erosion and that it was 

 given the broad, flaring U-form of a typical glacial trough. The 

 600-foot gorge now Hes in the bottom of this trough and still retains 

 perpendicular or nearly perpendicular rock walls throughout much 

 of its extent. If this gorge was formed by a preglacial stream it 

 must have survived the deep scouring which lowered the bottom 

 of the valley to an extent of some 200 feet or more and modified its 

 form to that of a typical U-trough. It is hard to believe that such 

 a gorge would not have been widened by the ice and made a part 

 of the U-trough had it been in existence while the erosion was in 

 progress. At least the sharpness of the gorge walls would have 

 been destroyed. It is true that, on the southwest wall of the gorge, 

 this sharpness has been to some extent destroyed, but this is 

 probably the result of erosion by the ice of some of the later periods. 

 The northeast wall is still sharp. 



A further point which may have a bearing on this problem is the 

 fact that in the valley of Fall Creek there are drift-filled gorges, as, 

 for instance, those just north of the Triphammer Bridge, whose 

 bottoms are nearly 200 feet above that of the 600-foot gorge in the 

 Six Mile Creek valley. Certainly these gorges cannot belong to the 

 same cycle as the 600-foot gorge, for both seem well graded, yet 

 their base levels are so different. If either is preglacial it must be 

 the higher one. Buried gorges at levels higher than our 600-foot 

 gorge are to be found in several of the valleys of the region besides 

 that of Fall Creek. On detailed study, with careful leveling, it may 

 appear that even the 600-foot gorge of Six Mile Creek belongs to a 



gorge in the valley of a small stream which enters Cayuga Lake from the east at 

 Shurger Point. In following up the gorge of this stream one soon encounters a series 

 of cascades and falls aggregating perhaps 75 feet in height. Above these cascades 

 is a gorge 100 feet, more or less, in width at the bottom, with rock walls, and 

 a remarkably even, low-gradient rock floor. The gorge, with these characteristics, 

 continues upstream for half a mile to a point just below the trolley track (one mile 

 from the lake), where it suddenly ends, the rock walls disappearing under drift, and 

 the stream tumbling in over a fine fall 60-80 feet in height. The bottom of the upper 

 section of this gorge has a low gradient and hangs at a level somewhere between 60 

 and 100 feet above that of Cayuga Lake. 



