542 STRATIGRAPHICAL GEOLOGY. 



passage of the glacial sheet. Two miles from Moody pond is an excel- 

 lent exposure of this quartz upon Campbell hill, dipping about 65° N. W. 

 The rock here partially resembles buhr-stone, being of a grayish color, 

 and filled with numerous reticulated veins of white quartz. The ledges 

 extend perhaps half a mile, and are then covered up by the sand plains 

 bordering the Merrimack river. The same cause prevents a view of the 

 white bosses on the west side for about two miles. As there is a curva- 

 ture in the river, causing the water to flow in the same direction with the 

 trend of the strata, more of the rock is concealed than would be the case 

 ordinarily at a valley crossing. The quartz shows itself first at G. Kim- 

 ball's, in Manchester, A high terrace conceals it back from the house, 

 and it has been noticed next on the hill west, on the road east of Black 

 brook, and close by the west line of the town, dipping north-west. A mile 

 farther to the south-west it may be seen at E. Dow's, in Goffstown, after a 

 long stretch of sand. On the south-west side of the Piscataquog river 

 the place of the quartz is near J. Black's. Another ledge is near a saw- 

 mill, a mile to the south-west; and the same is true of another mill 

 about the same distance beyond in the same direction. Next succeeds 

 a long interval away from roads, which has not been traversed. After 

 reaching the roads in the north part of Bedford the quartz is not seen 

 till we approach the Amherst line, at E. C. French's, and at another 

 place still nearer the boundary. In the very north-east corner of Am- 

 herst is a well known locality of hard siliceous limestone, carrying gar- 

 nets, idocrase, and other interesting minerals, immediately overlying 

 quartz, all dipping N. 50° W. Three other outcrops show themselves in 

 the course of a mile. After that, partly on account of the presence of a 

 great amount of drift, the rock is traceable with difficulty, and it seems 

 to pass more southerly. At the crossing of the south tributary of Ba- 

 boosic pond, in the middle of the town east and west, is a large pile of 

 quartz blocks, too numerous to have been transported by drift. Less 

 than a mile north of the village is a narrow band of the quartz, twenty- 

 five feet wide, on the west of the two roads leading to Manchester. 

 The strike is N. 20° E., the dip vertical. At W. A. Mack's, just against 

 the most south-eastern corner of Mont Vernon, there is an unusual 

 quantity of quartz boulders. 



We find now the same state of things which has been noticed between 



