96 GEEEN MOUNTAINS IN MASSACHUSETTS. 



and Stockbridge lfmestone, that the quartzite was succeeded by gneisses 



with conformable strike and easterly dip, which are often quite coarse, 

 with bine quartz, resembling the granitoid gneiss. This feature can be 

 noticed at several places; for instance, east of the exposure of quartzite 

 at the extreme south end of the map. We go east for nearly a mile, find- 

 ing gneisses, part coarse, part tine, and then come to massive quartzite, 

 and well-marked conglomerate (not metamorphic gneiss-conglomerate), with 

 pebbles of bine, white, and black quartz. The quartzite also circles around 

 the eastern part of this area in Dalton (south of the limits of this map), 

 where it is again associated with limestone. We find rather contorted 

 gneisses in the central part of this area, under the word "Dalton 7 ' on the 

 map, and farther north massive quartzite with north and south strike and 

 varying dip, which is the southern continuation of that forming the sharp 

 quartzite "points" of the mountain in Cheshire. So this part is evidently 

 composed of numerous north to south troughs of the quartzite and conglom- 

 erate, with areas of the underlying gneiss, the quartzite covering the gneiss 

 at both ends and being folded under it on the west. 



This statement is also true of an area running south from the second 

 point of the mountain, where the rocks are quartzite, quartz-schist, and 

 quartzose gneisses, with beds of quartzite-conglomerate, the strike being 

 north and south and dip steadily east. 



In the region directly south of Dry brook we have coarse gneisses with 

 blue quartz, underlying the fine grained quartzose gneisses (Vermont) which 

 represent the quartzites, and therefore perhaps correspond to the granitoid 

 gneiss (Stamford gneiss) of the central part of Hoosac mountain. 



In Windsor we have the same series of white gneisses, the conglomerate 

 character not marked, it being probably too far east, and the increasing 

 metamorphism having perhaps masked the original characters. 



A large part of this area is very poor in outcrops, being flat and drift- 

 covered. We have therefore described this large region principally in 

 reference to its boundaries, where by the contact with other rocks the true 

 relations and structure can be determined, and we hope that our observations 

 establish — first, the conformity of the Stockbridge limestone and Vermont 

 quartzite, the latter underlying when in the normal position, as is shown by 

 the contacts and lithological passage and the fact that the limestone is sharply 



