82 GREEN MOUNTAINS IN MASSACHUSETTS. 



and dip 15° easterly. From this contact the line of the two rocks is easily 

 followed over the hills to the south fork of Tophet creek, 1 mile. Here, after 

 crossing numerous exposures of the western band of gneiss, the creek falls 

 over cliffs of the typical albite-schist with same strike (north 10° west), and 

 gentle easterly dip under the overlying white gneiss, with which it is con- 

 nected by transitional beds as before. The schist is always garnetiferous. 



From here for half a mile the schist can only be traced by loose pieces 

 and one outcrop until we reach the corner of the mountain; here we find 

 it again in place and the contact with the overlying gneiss is within 2 feet 

 of strata. Both are conformable in structure and strike north 45° west dip- 

 ping 25° northerly. Here both rocks arc turning to assume their east to 

 west strike at the extreme point of the turn (curve), and only crumpled out- 

 crops of schist are found, as is usual in these turns. 



Following the schist east one-half mile we find it overlying the west- 

 ern band of white gneiss, which has here curved around so as to lie south: 

 the upper contact is not seen; the schist is garnetiferous and passes into 

 the underlying white gneiss by micaceous layers. The strike is north 75° 

 east, dip 25° northerly, and one-quarter mile farther east cliffs of the gar- 

 netiferous schist are found striking east and west and dipping 20° north, 

 closely and conformably underlain by the southern band of white gneiss. 

 From here for a mile only fragments of the schist are found. Within a 

 quarter of a mile of the extreme turn a small outcrop of feldspathic schist, 

 exposing a thickness of 30 feet, is interstratified with the tine-grained gneiss; 

 strike north 4(1 west, dip 20° north. One-half a mile farther in the line of 

 the strike of the gneisses, which are curving at the extreme point from an 

 east to west to a north to south strike, a solitary outcrop of garnetiferous 

 and feldspathic schist is found, with a vertical dip and strike north 10° 

 east, which represents probably the last trace of this tongue, which we 

 have followed continuously from the main mass. It seems to be squeezed 

 out in the folds of white gneiss. 



We come now to the band of gneiss (Vermont formation) lying west 

 of this band of Boosac schist. All of this gneiss follows closely the schist 

 around to the extreme southeast point, where it merges into the great area 

 of gneiss in the southern part of the map. The gneiss of this area has a 



