MOUNT GKEYLOCK. 



173 



from East mountain (Fig. 74, p. 194). Here the strata are horizontal or dip very low 



east, ami are crossed by a cleavage-foliation, as shown in Fig. OS. The section passes 



along the foot of these cliffs. The upper 



bench of Saddle Ball, shown in Section L in 



the upper schist, and also in the views (I'l. 



xiv and Fig. 74), does not correspond to 



any calcareous horizon. A quarter of a mile 



north it measures about 800 feet in width. 



Section I, lias been extended through East 



.mountain, where the strike changes to north 



40° to 50° east, crossing the trend of the 



hill, and a sharp syncline occurs iu the schist with the limestone of the Hancock valley 



dipping under it on the west. This schist is continuous with the lower schist of 



the Greylock mass, but the outcrops did not yield further structural data. East 



mountain seems to be one of the subordinate folds of the Greylock synclinorium 



which would thus measure here nearly seven miles in width. 



Fig. 68.— Structure in si 'hist iu cliffs on south side 

 iddle Ball above the Bellowspipe limestone. 



Fici. 69.— Cross-sections M, N, O. 



Section M, PI. xxi, begins about midway between Cheshire and Cheshire Harbor. 

 'fhe axis of tin' central syncline seems to continue in the lower schists across Bound 

 rocks, where a cliff about l.ooo feet long from east to west and 150 feet high shows 

 low east dips at its west end and low west dips at its east end. (See Fig. 74.) 

 Bast of this point observations were few and unsatisfactory. Farther west the sec- 

 tion crosses Sugarloaf mountain, which is a, small open syncline. (See Appendix 

 B.) West of it a number of minor folds produce the frequent alternations of 

 sehist and limestone about New Ashford. The entire synclinorium here consists of 

 a greater number of smaller folds. The section is below the horizon of the upper 

 limestone. 



