GEOLOGY OF THE MERRIMACK DISTRICT. .533 



appear at Mrs, M. French's, E. Little's, etc., but it is not easy to obtain 

 satisfactory dip observations. Farther south, as at E. Shepard's in Web- 

 ster, the strike is well defined, running S. 20° E., the strata being vertical. 

 These are repeated by J. and Capt. I. Allen's, nearly a mile farther south. 

 Other observations enable us to color this rock as a narrow strip east of 

 the porphyritic ridge as far south as Hopkinton. In Boscawen village 

 there is a gneiss, possibly of this age, dipping 60° E. It resembles the 

 Concord granite, and lies at the north end of the village. There are 

 many ledges of this gneiss in the Blackwater valley at North Salisbury, 

 at the lower end of the bay. Others occur farther south, north of J. 

 Wiley's, and at his house. The area makes a notch in the porphyritic 

 rock in the south-west part of the town. Along the Blackwater valley 

 many ledges are obscured by alluvium, and we have not had the oppor- 

 tunity to travel along the two long stretches of nearly parallel east and 

 west roads in Salisbury. In Webster, and north of Long pond, the pecu- 

 liar features of the Lake gneiss are clearly recognizable in its granitic 

 aspect and the traversing by numerous segregated veins. Ledges are 

 noted at the north end of the porphyritic ledge dipping S. 20° E. ; at the 

 mills by the crossing to Corser hill from the west ; at the top of the hill 

 west, overlooking Long pond, where are large veins of quartz ; north of 

 this pond ; and by the water's edge, where several houses occur near 

 together. In most of these cases the dip is obscure. At the last-named 

 locaHty the strike is N. 30° E, The long hill south-west from Long pond 

 shows many ledges resembling this formation as seen from the valley 

 west. 



In Warner observations are more abundant and satisfactory. West of 

 the Long pond exposures in Webster we find the schists to the town line 

 considerably ferruginous before coming to the isolated porphyritic area, 

 and also west of Mud pond in Warner. Compact gneiss is abundant from 

 this porphyritic outlier southerly as far as the alluvium of Warner river. 

 Back of the school-house the layers are ferruginous, — less so at T. H. 

 Bartlett's. The gneiss is of the normal variety at S. Bartlett's, on top of 

 the high hill west of Schodac brook. Most of this hill is composed of 

 drift. Between J. C. F'landers's and the lower Warner village granitic 

 gneiss occurs with diverse dips, at first to the north-west, and near the 

 village 80° S. E. Between the two villages the dip is 80° N. 20° E. A 



