GEOLOGY OF THE CONNECTICUT VALLEY DISTRICT. 363 



end being supposed to be the same with those in the synclinal between 

 the road to Norwich and the railroad. The latter arc not certainly seen, 

 but are believed to continue from the line of exposure fartlicr north in 

 the east part of Norwich. The thickness of the Iluronian here may be 

 estimated at about 2500 feet, allowing for five duplications. 



On reaching the railroad, a band of hornblende schist crops out, dip- 

 ping only 45° N. 85° W. This is the range appearing on Observatory 

 hill in Hanover. The angle of the dip is the same at the lower falls, on 

 the east bank of the Connecticut river. This is an interesting place to 

 observe the course of narrow quartz veins, sometimes cutting the strata, 

 and then running between the planes of deposition. On reaching the 

 carriage-road, the strata dip 70° W., thus suggesting the presence of an 

 inverted anticlinal. Passing from the house at the foot of Craft's hill 

 easterly, loose materials conceal the ledges for 2000 or 3000 feet ; and 

 then crumbling mica schists, sometimes calcareous, appear in the hillside, 

 standing about vertical. These belong to the Coos group, and may over- 

 lie the hornblende schist, which appears higher up and extends nearly to 

 the summit. The latter dip 75° W., and are certainly four hundred and 

 fifty feet wide on the surface. Craft's hill has two summits ; and upon 

 the west side of each the hornblende rock appears, continuous from one 

 to the other, besides extending down the south slope to cross the Mas- 

 comy river a mile east of the Connecticut. On the summit ridge, in 

 several places, are mica schists dipping from 6o°-8o° W., and occasion- 

 ally holding staurolite. In a few places quartzite occupies beds in these 

 schists, closely resembling the Coos quartzite of Moose mountain. It 

 may not be more than a fathom thick upon Craft's hill, but it is thicker 

 upon Colburn's hill to the north, and is still more abundant in Hanover, 

 it having been followed through that township into Lyme. Hence it is 

 believed this small development upon Craft's hill represents the horizon 

 of the Coos quartzite. The country falls off east of the summit of this 

 hill ; and the next rocks are the two members of the Bethlehem group 

 in the Hanover-Lebanon area described on a previous page. The great 

 value of the eastern part of this section is the development of the whole 

 Coos group, though in greatly reduced dimensions. Samples of every 

 part of its representation upon the west side of Moose mountain appear 

 here. Hence it is plain that the formation is repeated upon Craft's hill; 



