146 J. L. Rich — Physiography and Glacial Geology 



somewhat by glacial erosion. (As indicated on a following 

 page, it was an important channel of ice movement.) 



Two minor passes through the Central Escarpment near 

 Stamford seem, like that at East Windham, to be due to valleys 

 beheaded by recession of the scarp. 



Of the three deep passes or " Cloves " through the Central 

 Escarpment, Grand Gorge is one of the most significant. It 

 is a double pass. The higher pass at 1900 feet seems to 

 represent a mature beheaded valley like those just mentioned, 

 though somewhat sharper. Just east of this is the deep, rocky 

 " Grand Gorge" cut down to 1560 feet, and in every way a 

 true gorge with naked rock ledges rising almost perpendicularly 



Fig. 5. 



Allies. 

 Interval /oo feet 



Fig. 5. Sketch of Grand Gorge to show the double character of the pass. 



on either side. The gorge gives every evidence of having 

 been stream cut at a relatively recent date. The only stream 

 which could have done the work must have been glacial. It is 

 difficult to understand why this glacial stream did not utilize 

 the pre-existing 1900-foot pass, unless it started marginal to an 

 ice lobe which, pushing through the pass, may have closed it 

 effectively until the marginal channel became permanently 

 established (fig. 5). The " gorge " was later utilized as the 

 outlet of the glacial Grand Gorge Lake, to be described on a 

 later page. 



Deep Notch, 15 miles to the southeast (Phoenicia quadrangle), 



and Stony Clove, 14 miles farther southeast, are both deep 



(1400 feet), exceedingly narrow, steep-sided clefts through the 



range, and, as has been suggested by Darton,* are very likely 



*Darton, N. H. ; N. Y. State Museum, Report 47, 1894, p. 565. 



