GEOLOGY OF THE MERRIMACK DISTRICT. 559 



ping 50° S. 55° E. South and west of Potanopa pond is a fine- 

 grained granite that has been quarried somewhat. It has a rusty color, 

 so far as seen. At the very west end of the pond, by E. Wheeler's, 

 the granitic gneiss dips 50° S. 35° E. In the east part of Mason, or 

 about the town line, there is an anticlinal. At W. Scripture's, coarse 

 and fine granitic gneisses intermingled, dip 50° N. 70° W., — the dip being 

 about north-west half a mile to the east. A mile west of Scripture's, the 

 gneiss is coarser, dipping 40° westerly. There is a dark micaceous 

 variety between the Peterborough & Shirley Railroad and Mason centre. 

 The dip is 15° W. at Mason. On the summit of the ridge west, midway 

 between the post-office and the west line of the town, the granitic gneiss 

 dips 20° N. 85° W. Essentially the same dip occurs on all this high 

 land, certainly for two miles to the north. On a parallel line two miles 

 to the south, we find the rocks much like what has been described. 

 Gneiss at R. L. Cumnock's and at C. Blood's, near the railroad, dip 50° 

 N. 30° W. The ledges all over Mason resemble that of Lake Winnipi- 

 seogee, both in its granitic aspect, and the presence of segregated veins. 

 Between Mason and Greenville the ledges are abundant upon the high 

 land, dipping at a small angle to the north-west, near the first named 

 village. The dip is north between A. Elliott's and the railroad crossing, 

 and the mica predominates. By Pratt's pond and the edge of Wilton are 

 extensive granite quarries. The texture is fine, somewhat like the Man- 

 chester variety. A similar material is abundant by Elliott's mills, and 

 still farther north-east. Mica schists at Pratt's pond dip north-west. On 

 the hill west, small eruptive outbursts of the Manchester granite occur 

 frequently. In one place there is a ledge of porphyritic gneiss. Granite 

 is quarried between L. Joslin's and A. Elliott's, a mile south-east from 

 Greenville village. At the cemetery south of the village, the granitic 

 gneiss dips 25° S. 70° W. In the edge of the village there is another 

 ledge similarly situated. Our observations are meagre for the south- 

 east part of New Ipswich and the south-west of Mason, where this Lake 

 gneiss is supposed to extend. We find in Ashby similar rocks, and in 

 the west part of Townsend a fine-grained granite. 



Conclusio7is. I. The rocks of this Mason and Manchester gneiss area 

 are arrayed in parallel bands, according to their character. The north- 

 west part consists of micaceous gneisses and schists, holding layers of 



