. GEOLOGY OF THE CONNECTICUT VALLEY DISTRICT. 361' 



composed of greenstones mostly, with a bed of steatite and cupriferous 

 schists, once worked for copper. The steatite continues through the 

 town northerly into Thetford. The ledges north of the village of Nor- 

 wich are the same diorites. The boundary on the west side appears 

 about a mile above the village, at a bridge over the stream called Bloody 

 brook. At Kibling's old mill the schists dip 65° W. The stream exposes 

 other ledges of the same rock, all of the Lisbon group. In the valley to 

 the right of the road from the depot to Norwich village are dolomites and 

 thin-bedded schists, holding many small crystals of magnetite. The east- 

 ern base of the hill south-west from Norwich village is composed of green- 

 stones, cropping out at the tannery and on a back road farther south. 

 Section VI crosses this range in Norwich and Hartford; and the dips 

 upon it are uniformly high westerly. 



A few allusions to Huronian rocks upon Figs. 51, 53, and 55 may be 

 found in the descriptions of them under the head of Coos Group. The 

 ledges at Snow's (p. 360) are argillitic. 



In Fig. 58 we have the dehneation afforded by the facts descriptive of 

 Section VI. There is an excellent development of green dioritic schists 

 by the grist-mill on Bloody brook, near the railroad, dipping 65° westerly. 

 By S. Godard's, gritty schists dip 50°; and west of J. Newton's in Hart- 

 ford, at the base of the hill, softer layers appear, dipping 80° N. 80° W. 

 These facts afford data for perceiving the existence of two or three folds. 



The slate range is of considerable width at the north-west angle of 

 school-district No. 14, Norwich, and appears on both the roads running 

 west from the Connecticut before coming to the depot. It is an open 

 question whethet this is an equivalent of the Cambrian, or a part of the 

 Huronian. Turning on to the Thetford road, at the school-house No. 

 14, we leave a friable slate, and pass diabases and breccias on the right, 

 which make up the cliff alongside of the railroad. After passing the slate 

 range at the angle of the district, we find hard, green sandstones, accom- 

 panied by dolomite, at school-house No. 5. Similar dioritic schists appear 

 on the road at W. Johnson's, and on the line between districts 6 and 7. 

 About half a mile north of Norwich village is a narrow band of cuprifer- 

 ous schist; and east of the old meeting-house hill, near Deacon Cole- 

 man's house, is a bed of soapstone, where excellent specimens of green 

 talc may be obtained. 

 VOL. II. 46 



