508 STRATIGRAPHICAL GEOLOGY. 



along the line of its outcrop : we have here nearly all the features that 

 characterize the rock. At the extreme north end of Mine ledge, perhaps 

 half a mile south-east of the house of E. Grain, Jr., there is a narrow band 

 of the rock, with veins penetrating the protogene gneiss in every direc- 

 tion, making in many places a complete breccia. Southward the band of 

 quartz widens, until opposite school-house No. 4 it is not far from six hun- 

 dred feet in width. Just north of the road that passes through Mine 

 ledge, in the quartz we find quite a quantity of iron ore, chiefly limonite, 

 that forms botryoidal and mammillary masses on the quartz. From this 

 circumstance this quartz hill received the name it bears, though the ore is 

 not found in workable quantities. On the east side of the ridge there is 

 a high and precipitous wall of rock, and opposite this, on the west, the 

 ridge is quite steep. Besides the brecciated character of some parts of 

 Mine ledge, we find not only in the rock here, but elsewhere, that the 

 quartz encloses feldspar, generally partially decomposed, as though the 

 quartz had been formed in a great fissure, and that the vapor or solution 

 that carried the silica had penetrated the rocks adjoining, and absorbed 

 all but a remnant of the feldspar. 



Southward, on the railroad, instead of being concentrated mainly in one 

 vein, there are several. In the cut below the crossing, in the corner of 

 Keene, we find two veins with chlorite schist between : one of these 

 veins has well defined walls. In the Surry or "mile cut" the principal 

 vein of quartz is from twenty to thirty feet wide, is a breccia in part, and 

 is on the line of a fault. On the east side it abuts against hornblende 

 schist, while on the west there is gneiss, and in this there are several 

 small veins of quartz. Both of the larger veins follow the line of an axis 

 or a fault. South of the railroad, one band of quartz extends southward 

 along the east side of Gray's hill, and soon disappears. Another band 

 can be followed over Gray's hill and down on the south-west side. There 

 is an outcrop of the quartz at A. Parker's and at the Barker place in 

 Westmoreland, and also west of J. Hyland's, but all of these are compara- 

 tively narrow. 



On the east side of the Ashuelot river, in Keene, there are several out- 

 crops of the quartz, — one north-east of the cemetery, another south, and 

 still another near South Keene. On the east side of West mountain, 

 on the slope toward the Ashuelot, there are extensive outcrops. It is 



