166 GEEEN MOUNTAINS IN MASSACHUSETTS. 



TRANSVERSE SECTIONS H, I. 



From (he floosie river above Maple (iron station (South Adams) arross the central ridge, Bald mountain, 

 and the south end of Deer hill, to the Green river. Also Section H, across the summit (see PI. XX and 

 Figs. 63, 64). 



The observations east of the central ridge along this section are few 

 and unimportant. The lower schist belt measures about half a mile in 

 width, and the area of the overlying limestone and calcareous schist about 

 a mile in width. The latter is not overlain here by a subordinate mass of 

 schist corresponding to Ragged mountain, but ex- 

 tends uninterruptedly, and probably in a series of 

 very gentle undulations, up to the base of the cliffs 

 which form the east face of Greylock proper. The 

 contact between the two rocks, wanting on Section 

 I, can be seen in Peck's brook on Section J, the 

 no. 63.-cro3a.section h. calcareous schist underlying the feldspathic, non- 

 calcareous, micaceous, and chloritic schist, both with a westerly dip. On 

 the face of the cliff, locality 549, the cleavage foliation dips 65° east, and 

 the stratification foliation 15° to 25° west, and low west or horizontal dips 

 prevail to the summit, (See Section H, and Figs. 44, 46, 53, 54.) At the 

 top of the ridge which forms the seat of the saddle between Greylock and 

 Saddle Ball and so also just west of the Greylock summit the dips are 

 high east. The structure of the top of the central ridge here has thus been 

 construed as a minor syncline with a steep east slope on the west side and 

 a gentle west or horizontal one on the east side. 



The section line now descends a little north of Shattuck flats to the 



I 



Fig. 64.— Cross-sectiuu I. 



south fork of the Hopper brook. The observations above the flats are not 

 conclusive, but in the most southerly ravine, tributary to the south fork of 

 the Hopper, westerly dips occur, as they do also in the ravine running north 



