44 



GREEN MOUNTAINS IN MASSACHUSETTS. 



the Hoosic and Daltou valleys determined these depressions, as is always 

 the case with that rock. 



The profile of Hoosac mountain shows plainly the northerly "pitch" 1 

 of the formations by the gentle slopes to the north and the bluffs facing- 

 south. (See Fig. 10 and PI. xi, b.) The western slopes of Hoosac mountain 

 running down to the Hoosic valley are steep, but have a marked series of 

 buttresses or benches. (See Fig. 11.) The drift-covered Hoosic valley is 



Fig. 11. — Profile of west slope of Hoosac mountain, from Hoosic valley opposite Adams, looking north. 

 This figure shows the buttressed character of the west slope of the mountain at the left center. These buttresses are 

 of crumpled white gneiss (Vermont formation), with a gentle easterly dip. 



comparatively flat, sending branches into the mountain, which are locally 

 called "coves." At Cheshire the valley makes a sharp turn to the west. 



DESCRIPTION OF THE ROCKS OF HOOSAC MOUNTAIN. 



The rocks of this region are thoroughly crystalline, but little trace 

 remaining in general of their original elements, whether of detrital or erup- 

 tive origin, but the bedding corresponding to the original planes of deposit 

 is well marked, and, under the proper conditions, we can therefore deter- 

 mine the order of succession. 



1 Meaning that the axes of the folds are inclined or " plunge " in that direction. 



