GEOLOGY OF THE CONNECTICUT VALLEY DISTRICT. 4O9 



Mt. Wantastiquit, opposite Brattleboro'. Southward the valley is much 

 broader, but still it is bordered by high ridges, those in Vermont being 

 near the river. So far as the general features of the country are con- 

 cerned, they differ very little, as the rocks change. Skitchawaug moun- 

 tain is quartz-conglomerate. Kilburn peak is gneiss, and Wantastiquit 

 is mostly argillaceous schist or slate ; yet Skitchawaug, as seen from the 

 west, differs very little from Kilburn peak as seen from the east, or Wan- 

 tastiquit as seen from the same direction. The area of country in which 

 the rocks are here described begins with the north lines of Charlestown 

 and Unity, and extends southward to Hinsdale. The line limiting it on 

 the east runs a few rods east of Unity Centre, and southward just east of 

 Acworth Centre, through Alstead, diagonally, the south-east part of Wal- 

 pole, and through Westmoreland and Chesterfield. The gneiss of Kilburn 

 peak is an island surrounded by newer rocks. In Westmoreland the east 

 line extends westward nearly to the Connecticut, but in Chesterfield it 

 turns eastward to a point east of Factoryville, whence it extends south- 

 ward to the state line. The rocks in Vermont immediately along the 

 river will also be noticed. 



The rocks belong chiefly to the Coos group, but, considering the large 

 extent of country, there are not many different kinds. Besides the rocks 

 of the Coos group, we have a few that belong to the older formations. 

 The following is the order in which the rocks occur, beginning with the 

 lowest: I. Bethlehem gneiss. 2. Gneisses of the Montalban series. 3. 

 Huronian. 4. Coos quartzites. 5. Coos slates and schists. 6. Calcifer- 

 ous mica schist. 7. Eruptive granite. 



I. Bethlehem Gneiss. 



The Bethlehem gneiss does not differ essentially from that found in 

 the northern part of the state. The feldspar is generally flesh-colored, 

 and it contains a greenish mineral, probably chlorite, while associated 

 with it here and in places in the topographical area east there is a very 

 marked band of quartz. The principal outcrop is on Quimby hill in 

 Unity, though it extends across the valley west, and appears on the east- 

 ern slope of the hill near E. T. Bailey's, and connects with that in the 

 east part of Claremont, It can be seen in the south-west part of the 

 town, near M. Johnson's, and it is probably continuous from Quimby hill 



VOL. IL 52 



