172 



GREEN MOUNTAINS IN MASSACHUSETTS. 



probably overlies the Eoosic valley limestone. Along sections K and L there is dif- 

 ficulty in tracing the connection of the upper calcareous belts of both sides of the 

 central ridge, owing to the absence of outcrops on the west side of Saddle Ball. The 

 central ridge (Saddle Ball) there slopes off to the east at an angle of about 10°, form 

 ing a bench which is even less inclined than that on the west flank of the mountain. 

 See the view from Lenox mountain, PI. xv. The conjectural track of Horizon Slip. 

 which on the map joins the outcrop of micaceous limestone at the south end of Sad 

 die Ball (''Jones's Nose") with those in Peck's brook, Section J, has been drawn to 

 conform to the strike and trend of the central ridge, and to those of the calcareous 

 belt on its west side. It is based on both structural and topographic considerations.- 

 (Compare the remarks on Section I).) , On the west of the mountain and about Gulf 

 brook there are calcareous schists separated from the upper calcareous belt by non- 

 ealcareous schists. These have been thrown into the lower schists as probably repre- 



Fiq. U7.— Cross aectious J, J£, L. 



senting mere transitions from the lower limestone to the lower schist, such as were ob- 

 served at several localities over small areas (Deer hill, 030; Lanesboro, 365; New 

 Ashford, f>,">0), and are thus regarded as only indicative of the proximity of the 

 lower limestone. 



In Section L the opening out of the compressed and overturned fold of the central 

 ridge into a very broad and open syncline is seen. The calcareous belt of the Hopper 

 becomes here a gently sloping bench of arable land nearly a quarter of a mile wide, 

 once dotted with farms, and still used for pasturage. (See PI. xiv.) The rock 

 becomes much more calcareous, and dips east at a low angle under the upper schists 

 of the central ridge, and bends around eastwardly between Saddle Ball and 

 Round rocks, the former consist ing of the upper and the latter of the lower schisis. 

 The upper schists form a cliff on the south side of Saddle Ball at the incision in 

 the central ridge, which is seen so plainly from the Tacomic range (PI. xm), and 



