CHAPTER VIIT. 



THE BANDS OF SILURIAN SCHISTS ON THE EAST SIDE 

 OF THE VALLEY. 



As noted in the geological outline and the generalized section in 

 C'hupter III, the representatives of tlie Silurian series from the Hoosac 

 schists to the Conway schists are present east of tlie river in several narrow 

 svnclinal bands resting in the Monsoii gneiss, which are most conveniently 

 described in geograi)liical rather than geological order. The series is 

 greatly simplified and is divisible into only four or five members — a mus- 

 co\'itic or sei'icitic and biotitic (}uartzite below; next a band of hornblende- 

 schist (amphibolite) ; above this a thin-bedded biotitic quartz-schist, which 

 I have called the whetstone-schist, as it is much quarried for scythestoues; 

 then a garnetiferous and graphitic schist. These are, respectively, referred 

 to the Rowe schist, the Chester amphibolite, the Savoy schist, and the 

 Conway schist of the western side of the valley. Along the eastern border 

 of the region the series is still more simplified l^v the disajjpearance of 

 the hornblende-schist, and the lower bed, which includes the Rowe and 

 Savoy schists, is developed across Worcester County as a monotonous, thin- 

 bedded micaceous quartzite which I have named the Paxton whetstone-schist, 

 while the upper bed, the Conway schist, grows more metamorphosed east- 

 wardly and southerly and becomes rusty, strongly fibrolitic, coarsely 

 graphitic, and in places feldspathic. This I have named the Brimfield schist 

 in Worcester County. 



I have, then, to descriV)e the following areas (see geological map, PI. 

 XXXIV): 



1. The Northfield semisyncline. 



2. The Wendell branch syncline. 



3. The Leverett-Amherst area. 



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