14 JOSEPH H. PERRY 



near the sources of the main streams which would be the last to 

 be brought low.' 



SUMMARY. 



1. This mountain is made out of a syncline in andalusite- 

 fibrolite schist, probably of Carboniferous age. The syncline 

 was produced by the intrusion of granite, which modified the 

 schist already metamorphosed. 



2. The schist contains andalusites changed to fibrolite and 

 sericite, also fibrolite changed to sericite. 



3. The jointing of the schist was produced by the folding; 

 therefore the intrusion of the granite, which produced the 

 folding, took place when the schist was in the zone of fracture. 



4. There is an older folding evident, which must have been 

 produced when the schist was in the zone of flowage. 



5. This mountain and the other monadnocks to the south on 

 the Atlantic-Connecticut River divide, probably owe their survival 

 to their position, rather than to the greater resistance of the 

 rocks composing them. 



Joseph H. Perry. 

 Worcester, Mass. 



^ Mount Grace, in Warwick, Mass., rising about 500 feet above this plateau, and 

 situated about six miles from the Connecticut, far to the west of the divide, owes its 

 survival, probably, to the greater resistance of its rocks. It is made up largely, or 

 entirely, of amphibolites, while the surrounding plateau is made up of mica schists 

 and granite. 



