MOUXT GEEYLOCK. 



175 



General pitch of the folds. — The observations of pitch are recorded on 

 the map by a special symbol. It will be noticed that tin- direction of the 

 pitch through the northern part of the central ridge is south, while at its 

 southern extremity, west of Cheshire reservoir, it is north. Sugarloaf 

 mountain, New Ashford, has a northerly pitch at its south end, and a south- 

 erly pitch at its north end. Ragged mountain has a southerly pitch at its 

 north end, and the succession of the horizons at the surface and other facts 

 indicate a northerly pitch at its south end. From the "Bellowspipe" the 

 pitch is probably both north and south. In places a similar pitch seems to 

 prevail along parallel lines across the central ridge as we'll as the subordi- 

 nate folds; thus the southerly pitches on the Bald mountain spur, the north- 

 erly pitches on Potter mountain, Constitution hill, and the Noppet, and 

 on Savage mountain in Lanesboro; again, the northerly pitch at Cheshire 

 Harbor is undoubtedly repeated at bound rocks, although not observed there 

 in the plications. 



LONGITUDINAL SECTIONS. 



The facts stated above are shown on the four longitudinal sections 

 appearing on PI. xxm. Three of these, on a reduced scale, are given in 

 Fig. 71. The north is at the right. 



Fig, 71.— Longitudinal sections P, Q, R. 



Section P follows for 12 miles the axis of the eastern or Ragged 

 mountain svncline, beginning at the Hoosic river a little south of North 

 Adams, between Cross-sections A and B. At the north end of Ragged 

 mountain the upper limestone and the upper schist horizons are shown 

 with the steep southerly pitch which marks the whole northern end of the 

 Greylock mass (compare the symbols on the map). On Cross-section F 

 there is a thinniner of the lower schist. There are some indications of a 



