76 GREEN MOUNTAINS IN MASSACHUSETTS. 



west direction, followed closely by the overlying schist. The rocks here are 

 very much crumpled; the axes of the crumplings have a steady direction 

 about north 10° east and a gentle northerly inclination of 10° to 15°, 

 while the actual line of outcrop runs northwest down the mountain. In this 

 way the schist mantles over the conglomerate and follows it down; grad- 

 ually the line of outcrops turns and runs nearly straight down the moun- 

 tain until the extreme point is reached nearly half way down to the valley. 

 Here we find the gneiss striking north 10° east and pitching 10° to 15° 

 northerly, very much crumpled, and passing under a cliff of the schist like- 

 wise crumpled. The two rocks are here again connected by transitional 

 layers in which bands of white gneiss alternate with bands of schist, and 

 the gneiss contains a great abundance of the porphyritic feldspars; the 

 schist is also the dark garnetiferous variety. At this point the same change 

 of position previously described occurs, namely by a sudden turn, which 

 can be traced by connected outcrops; the schist comes in on the west side 

 of the white gneiss with a strike north 10° east, a strong northerly pitch, 

 anil a dip of the foliation (very much crumpled) generally steep west. 

 The reader is referred to the map (PI. iv) for the graphic presentation of these 

 facts; the outcrops have been carefully traced step by step and important 

 points located by placing flags in the trees and putting in the points by the 

 plane table. Note how closely the apices of the turn in the granitoid gneiss 

 and white gneiss coincide, showing the conformity of the series. After the 

 rocks have made this turn so that the overlying formations come to lie suc- 

 cessively west of one smother, there is no difficulty in tracing their course 

 to the south along the side of the mountain. From the turn in the contact 

 between granitoid gneiss and white gneiss-conglomerate, the line of contact 

 runs obliquely down the mountain in a south by west direction for about 2 

 miles, where it reaches its lowest point topographically; the actual contact 

 has not been found, although the two rocks commonly come close together, 

 but talus from the granitoid gneiss conceals the contact. The white gneiss 

 often forms a flat bench 100 or 200 feet wide. The structure of the white 

 gneiss, as mentioned before, dips very steeply west just after the turn; 

 within a quarter of a mile it is found to dip near the contact with the gran- 

 itoid gently east, from 10° to 25°; but commonly the rock is greatly crum- 



