THE INTERGLACIAL GORGE PROBLEM 



M3 



channel (^), east of the postglacial gorge, is strengthened by 

 the fact that the channel west of the postglacial gorge is too 

 narrow and too shallow to be the continuation of the broad chan- 

 nel south of the ridge. The existence of a channel {B) beneath 



Fig. 3. — Terraces in the drift-filled gorge of Six Mile Creek. 



the middle ridge is very apparent in the field; and is fairly well 

 shown by Plate VI. A boring made on the top of the ridge to 

 a depth of ten feet did not strike rock, although the bottom of 

 .this hole is more than twenty feet below the highest rock in this 

 ridge. The channel between the middle and north ridges seems 

 rather narrow to be the continuation of the broad channel on the 

 east side of the map, and the well-defined indentation (see Plate 



