568 STRATIGRAPHICAL GEOLOGY. 



north-west. These facts are embodied in Fig. 96. Sanbornton mountain 

 has not been visited, but it is supposed to consist of mica schists. On the 

 north side of White Oak hill, near Bristol village, the same schists dip 

 south-east. Ledges are abundant on the high hills opposite Hill, but they 

 have not been examined. In Hill the rocks are mostly mica schists. 

 Two miles west of the village, at a fall in Flanders's brook, the dip is to 

 the south. At the town-house the schists become ferruginous, and dip 

 south-east. The hills to the north-west seem to possess the same char- 

 acter. No other ledges appear in proceeding south-west from the town- 

 house till we come to the Kearsarge schists in Andover. 



In Franklin, a mile and a half south of the Hill line, the schists dip 50° 

 S. 40° E. At J. W. Simonds's is a local anticlinal, the dips being 80° N. 

 70° W. and 80° S. 50° E. This is at an angle in the valley, the rock 

 crowding the river easterly. This axis is continued at S. G. Pike's, a mile 

 to the south-west. Near the town farm the rock is gneissic, and has been 

 quarried. Beyond H. N. Ingalls's the dip is 60° S. 25° E. At S. Judkins's 

 the rock is garnetiferous, and dips 80° S. 15° E. The dip is the same in 

 a gneissic rock a quarter of a mile to the west, above the sand. There are 

 many embossed ledges of these rocks in the north-east part of Franklin. 

 The structure of the Andover spur of Montalban may be learned from an 

 examination of the positions along Section V. At the village the dip is 

 80° S. 50° E. At A. and J. E. Colby's it is 80° S. 30° E. At the south 

 end of the Webster lake it is 50° S. 30'' E. It is 65° S. 30° W. at P. 

 Garrily's. The ridge west, in Andover, is covered by drift. These ledges 

 might be the northward continuation of the Salisbury gneiss, unless that 

 line is indicated by the Webster lake anticlinal. At the crossing of the 

 railroad by M. M. and P. Durgin's, the dip is 65° S. 40° W. West of 

 Horseshoe pond the dip is 70° W., the rock being ferruginous. Per- 

 haps this may be regarded as the western limit of the Montalban rocks. 

 So nearly alike are the mica schists of the different groups that no satisfac- 

 tory line of demarcation can be drawn, with our present limited knowl- 

 edge. Near the south line of the town the high hill east of Bradley pond 

 is a synclinal of ferruginous and other schists. On the north side the dip 

 is S. 17° E., and in the opposite direction, on the south side, the north- 

 ern dip being much the steepest. The lower part of the hill is composed 

 of gneiss. At the town hue the schists arc ferruginous. The schists a 



