GEOLOGY DF THE MERRIMACK DISTRICT. 483 



as the common gneiss, except in a few small areas, is almost obliterated, 

 and in its place we have micaceous and hornblende gneisses ; and at the 

 same time the fibrolite schist assumes more the character of a well de- 

 fined gneiss. When it is known that these rocks have again their char- 

 acteristic forms, in Surry, it leaves little doubt that all these rocks — the 

 common, the hornblende, the micaceous, and the fibrolite gneisses, in- 

 cluding the fibrolite schist — belong to one great series. From near L. 

 Honey's in Acworth the common gneiss extends into Marlow, and its 

 southern boundary is probably just below Trout pond. Near H. Priest's 

 we again find the common gneiss ; but as we go northward we have mica 

 schist, at C. W. George's in Acworth. The rock has the character of a 

 fine-grained gneiss at G. H. Gassett's. At J. Buckminster's and S. E. 

 Mann's we have mica schist. Frequently in this vicinity we find bands 

 of hornblende schist. In the north-east corner of Alstead, near J. H, 

 Shepherd's, we have a fine-grained gneiss again. Going towards Mar- 

 low, and turning north by the cemetery, we find bands of hornblende 

 schist; but between the cemetery and Gustin pond is the boundary be- 

 tween these rocks and the fibrolite gneiss. At the forks of the road, east 

 of A. Mack's, and in Alstead, at A. Kent's, we have mica schist, the dip 

 being easterly, and nearly the same at both places. We have mica schist, 

 also, north, near Mrs. Whitcomb's ; and in the coarse granite veins here 

 there have been several openings made for mica. In the vicinity of Warren 

 pond we have common gneiss. An outcrop at J. Caldwell's, south-west 

 of the pond, has an easterly dip, and it seems to pass into a mica schist. 

 In the northern part of the town, on the south-east side of Cobb's hill, 

 there is a fine-grained gneiss, which has generally a westerly dip, though 

 the strata are often curved, so that in places they are inverted. One out- 

 crop, where it runs into the hill, looks like a section of a cone ; and here 

 we have schists on both sides of the gneiss. This has been noticed in a 

 preceding chapter. 



South-east, near the road up Warren brook, between J. P. Forrestall's 

 and L. Way's, there is gneiss again with an easterly dip, and about a mile 

 above Way's there is mica schist. South-west, at Mrs. Emerson's, on the 

 road north of Alstead centre, the rock is a quartzose mica schist, and the 

 dip is exceedingly variable. On the road south-west from the centre, we 

 have mica schist to the line of Walpole, except at George Pratt's, where 



