GEOLOGY OF THE CONNECTICUT VALLEY DISTRICT. 349 



through it. The rock south from the quarry is quite granitic. The 

 strike runs about east and west, changing abruptly from the north-east 

 curve in a quarter of a mile. There is a large quarry of granite at H. 

 Eastman's, about a mile north-easterly from North Haverhill, with other 

 smaller openings in the neighborhood, and a similar stone upon the high 

 hill-top north of French pond. By F. C. Handford's the granitic blocks 

 are so numerous as to suggest the close proximity of the ledge. Other 

 exposures of gneiss, dipping 70° north-easterly, appear at the south-east 

 of a hamlet north of North Haverhill. The enormous area of alluvium 

 along the valley of Demming Pond brook conceals the ledges over much 

 of this formation. 



On the road from North Haverhill to Swift Water Village are other 

 interesting gneissic outcrops. Hornblende schist and protogene gneiss, 

 dipping 65° S. 43° W., occur by W. C. Marston's and a school-house. By 

 R. M. Sly's, half a mile from the town line, we find ordinary gneiss dip- 

 ping 6S° S. 77° E. There are important irregularities in the course of 

 the strata, in the north part of Haverhill, not yet worked out. Close to 

 the Bath line, on the road passing French pond, the dip is 40° N. 72° W. 

 I observed along this road, also, a considerable hornblende schist. There 

 is protogene on the east side of Brier hill. There is an extension of the 

 Swift Water division of the Huronian, nearly as far as French pond, of 

 at least a mile and a half width along the town line, and a smaller pro- 

 jection up the valley of the tributary streams to the west. Between 

 these projections is a similar point of gneiss, to which allusion has been 

 made heretofore, as it seems to underlie the Swift Water rocks (Fig. 35). 

 It is the north-easterly continuation of the Brier Hill range. 



Another region of interest is afforded by the limestone and its sur- 

 roundings. There are numerous ledges of the gneiss, holding an excess 

 of black mica, on the road from Swift Water to the limestone quarry. 

 By E. Header's the dip is N. 26° E.; by H. & H. S. Carr's, and to the 

 south, the dip is about 70° N. 60° W.; by M. Mann's the dip is 70° N. 

 50° W. By S. Hartwell's the gneiss dips 85° N. 34° W., and the layers 

 seem to run to Black mountain in the north part of Benton. The lime- 

 stone dips N. 20° W. as much as 70° W. Of this rock there is an im- 

 mense supply. It occupies the valley of the north branch of Oliverian 

 brook, and may be several hundred feet wide. We have been unable to 



