GEOLOGY OF THE CONNECTICUT VALLEY DISTRICT. 35 1 



by Cods rocks. The i)rcdominant varieties of rock arc the same here as 

 before, the limestone occurring in a longer range, and the protogene ex- 

 isting in larger amount. Pine hill may be the north end of the outcrop 

 of this formation. It appears along the road over its northern flank. On 

 the north and south road, west of Pine hill, none of these ledges occur 

 north of the North Branch. Just to the south of this stream is a great 

 profusion of its boulders, suggestive of accumulation by glacial agency. 

 East of Sunday mountain, at the fork in the road, and by J. and A. Mars- 

 ton's, half a mile east, the protogene gneiss dips 80° N. 42° W. South 

 of L. Hancock's and the blacksmith's shop, the same rock dips the same 

 way. On the road north-east from J. Howard's the ledges are concealed 

 mostly, but it occurs both west, at J. M. Learned's, and east, at Mrs. R. 

 Hall's. On the north slope of Cuba mountain a hornblendic variety 

 crops out three or four hundred feet above the road, dipping 85° S. 17° 

 E. The rock seems to form a floor, on which the slates and quartzites 

 of Cuba rest, the latter series being probably isolated, so that in "Davis- 

 town" this area of gneiss connects directly with that of Wentworth and 

 Warren. 



There is a large development of protogene in the valley of Jacob's 

 brook. On the north side, near its western limit, it dips 80° N. 54° W. 

 The dip is essentially the same at its eastern limit. On the south side 

 of this brook, at the north base of Bass hill, a north-easterly dip of 85° is 

 recorded. The same rock extends to the summit of Bass hill, where it 

 holds a vein of quartz, with titanic iron and massive hornblende crystals. 

 East of A. English's, near the south Orford line, the dip is 70° N. 62° W. 

 On the same line, east of Lime hill, the dip is 60° N, 54° W., and half a 

 mile west, on the east side of Davison hill, the dip is 15° east. The hill 

 is composed entirely of the same material. 



An interesting feature of this area is the occurrence of a long line of 

 limestone. We have it first at the west base of Cuba mountain, near B. 

 Sanders's ; then it appears towards Lime hill. Just in Lyme, by D. F. 

 Tillotson's, it dips 40° N. 74° W.; at J. Smith's it dips 50° westerly. At 

 the fork of the road from Lyme turning to Dorchester and Canaan, there 

 is a long exposure of limestone dipping 60° N. 82° W. As one follows 

 the Canaan road, the limestone shows for a considerable distance. This 

 limestone can be traced continuously, therefore, for a distance of about 



