THE HOWE SCHIST. 77 



It is best studied in tlic contiiiiiatioii of tlic section idoiiii' the lioston 

 and Albiiny Hailroiid, beginnin;^- at tiic point reached on imge 72, at the 

 second bridg-e east of MickUelii'ld station. There is from this point a nearly 

 continuous cutting- for almost a mile tln-ough these light-green, (piartzy 

 sericite-schists, lier(» wholh' barren and monotonous. 



Just beyond the fourth bridge manv beds of a fiat-tissile, epidotic 

 ani])hibolite and of sericite-scliist are exposed, as follows, eastward from the 

 bridge: 



iSeciion of Roire .schist coHtainiiKj amphihoUte. 



Feet. 



Sericite-.schist 78 



Ampbibolite . . 23 



Sericite schist 1'3 



Amphibolite 3 



Sericite-scbist 7 



Amphiboliie 3 



Sericite-scliist 30 



Ampbibolite 150 



Sericite-scbist 59 



The same rock extends, poorly exposed, with a single small band of 

 amphibolite to the Chester amphibolite at the Chester line; whole thick- 

 ness, 820 feet. 



This is the first case where any amphibolite occurs below the Chester 

 amphibolite, and it is here that the remarkable overfolding or overcrushing 

 of the vertical beds of thin-fissile amphibolite occur, which has been figured 

 bv Pi'esident Hitchcock, who refers it to crushing by ice.' 



HAMPDEN COUNTY. 



The rock is best studied along the ( 'hester-lJecket road, westward 

 from the Chester emery mine, where much rock cutting has been done to 

 protect the highway from the mountain brook along which it runs. It is a 

 soft, greasy sericite-schist, often becoming very quartzose and then of firmer 

 texture. It enters the Granville quadrangle (and at the same time Hampden 

 County) at its northwest corner, and continues with a width of half a mile 

 to the pond at North Blandford. Two miles farther south, as noted in the 

 description of the Hoosac schists, the whole area across from the Becket 

 gneiss to the Chester amphibolite is biotitic and feldspathic and not mai'ked 



' Elementary Geology, p. 139. 



