438 STRATIGRAPHICAL GEOLOGY. 



Beyond this the rocks are covered for a quarter of a mile with gravel. 

 Then there is an indurated argillaceous schist, with many interlaminated 

 seams of quartz (No. 157), at a fork in the road, dipping 85° N. 40° W., 

 and also near a deserted house. 



For purposes of immediate comparison, I will introduce here the de- 

 scription of a section along the state line across this whole area, extend- 

 ing from Winchester to Guilford (Fig. 71). The previous section termi- 

 nates with No. 157, which is the point of intersection with the one about 

 to be described. The figures are taken from the catalogue of Section 

 I, as far as to Connecticut river. 



66, White gneiss, near E. Lyman's, Win- 69, 70, Tourmaline schists, and 



Chester,— dip, 20° N. 40° W. 71, Gneiss, dipping 40° N. 30° W. 



67, 68, Decomposing gneiss,— dip, 25° N. 72, -ji, Ouartzites, vitreous and jointed,— 



40° W. just east of tributary from the dip, 85° N. 25° W., and, in a few feet, 



north emptying into Perchog brook. 75° N. 65° E. 



The last named is on a hill constituting the high western bank of the 

 Perchog river. The gneiss is seen to pass directly beneath this quartzite, 

 both rocks retaining essentially the positions assigned above. It is there- 

 fore an excellent example of unconformity, as the quartzite is the younger 

 rock. 



74, Mica schist,— dip, 80° E. and 80° W. 76, Mica schist, siliceous, half a mile west, 



by school-house ; the same beyond. — dip 50° N. 30° E. 



75, Coarse granite vein in 74, by S. H. 'j']. Micaceous quartzite,— dip, 45° N. 45° 



Smith's. E. near C. Stebbins's. 



With this (No. Tj) are layers carrying nodular veins of quartz, — ferru- 

 ginous and argillaceous strata. Nos. 74-77 are clearly the mica schist of 

 the Coos group. This is the last specimen obtained in Winchester. 



78, 79, 80, Ouartzites, near W. Coombs's, Hinsdale, near Connecticut river, and dip- 

 ping 80° N. 30° E. 



Next succeed the quartzites adjoining the river on the west side, 60° 

 N. 20° E., and at the railroad cut dip one third as much. The rock is 

 mostly quartzite, with mica schist layers of different degrees of coarse- 

 ness. The south end of the cut is gneissic, and there is a trap dyke here 

 also. In the road adjoining the cut is mica schist, dip N. 18° E. In the 

 field west is a large development of hornblende schist, dip about 48° east. 



