GEOLOGY OF THE MERRIMACK DISTRICT. 5II 



The granite of Roxbury occupies an area in the south-west part of the 

 town, on the road running north-east from Cummings pond. Instead of 

 extending north and south, as most of the granite areas do, it extends 

 rather east and west. On the western slope of Horse hill, in several 

 places, the rock has been uncovered and quarried to some extent. The 

 joints are not so numerous as in many other quarries ; the principal ones 

 have a gentle inclination northward, and are from two to three feet apart, 

 while along the face of some of the quarries scarcely a vertical joint can 

 be seen. The rock here is somewhat peculiar in that it contains a few 

 bright garnets. From hand specimens one would be disposed to think it 

 was a vein-stone rather than the country rock. 



The granite extends northward, and there is an outcrop south of the 

 stream near G. Nye's, and probably this is its limit in this direction. 

 Westward from Horse hill, west of the road and south of Roaring brook, 

 is the Nye granite quarry; and a short distance south, but on higher 

 ground, is the quarry of the Keene Granite Company. The rock from 

 the two quarries does not differ very much, though that from the latter 

 is somewhat finer in texture than that from the former. The rock has a 

 brighter look, and the joints that run nearly horizontal are not so near 

 together, so that blocks of immense thickness can be raised. About an 

 equal amount of black and white mica, the bright colors of the feldspar 

 and quartz, and its pleasing appearance when cut, make it one of the 

 most attractive of our granites. Its use in the construction of the capitol 

 at Albany shows that it is appreciated. The rocks on the north, east, and 

 south, at least, are those of the Montalban series. 



It is quite probable that the granite of Roxbury extends across the 

 branch of the Ashuelot into Keene, since there is an outcrop of granite 

 on the Lawrence place. The rock here is very much jointed, but was 

 used in the construction of culverts and abutments of the Manchester & 

 Keene Railroad. On the hill south-west of this ledge we have a dark 

 granite similar to that found in Sunapee. The next area of granite going 

 southward is in Marlborough, south of the village. This is in shape more 

 like the common outcrops of Concord granite in the central and eastern 

 part of the state, and it is surrounded by the schists or gneisses of the 

 Montalban series. We suppose this to be a typical variety of the granites 

 of this section of the state. It is composed of light gray quartz, of ortho- 



