498 STRATIGRAPHICAL GEOLOGY. 



on the railroad near the outlet of Tewksbury pond, and on the hill be- 

 tween the pond and W. Aldrich's ; and south it is the country rock of 

 Isinglass mountain. Thence it extends south to Springfield, and has 

 a width of about a mile and a quarter. Along its entire outcrop it 

 has coarse granitic veins, and in these openings have been made for 

 mica. Through the town we have the Lake gneiss on the west and the 

 porphyritic on the east. 



In Springfield this rock is not so easily traced, and in the north part 

 of the town it seems to disappear altogether. Running southward from 

 Aaron's ledge to Col. Sanborn's hill there is a band of rocks, but they are 

 more micaceous than the common fibrolite rock, and as far as they have 

 been studied no fibrolite has been seen, though the coarse granitic veins 

 are common. 



In Sunapee the rocks between the porphyritic and the common gneiss 

 resemble those of the common White Mountain series. They can be seen 

 at the village of Sunapee Harbor, on the road north at J. Newton's, and 

 south at D. Winn's. Keyser hill, east of the narrow band of porphyritic 

 gneiss at the village of Sunapee Harbor, is composed of White Mountain 

 gneisses, sometimes granitic. The porphyritic band is probably an out- 

 lier of the great area to the south-east. The rock that outcrops near 

 Union church, in the south part of the town, consists of fine-grained and 

 micaceous bands, and is followed on the west by common gneiss. It is 

 closely allied to the typical White Mountain gneisses, and extends south- 

 ward into Goshen, where it outcrops along the west side of Sunapee 

 mountain. North-east of Mrs. L. Blood's we have both the micaceous 

 and granitic gneisses, though the former may be more allied to mica 

 schist than to gneiss. Here we find a peculiar form of fibroHte, which is 

 not seen north, but is quite common southward. It is sometimes green- 

 ish gray in color, is compact, and often has the semblance of crys- 

 tals, the centre portions of which have been removed by weathering. 

 East of L. Baker's we have prophyritic gneiss, then the band of mica 

 schist, and in this is a bed of graphite, from which years ago tons of the 

 mineral were extracted. 



In the south part of Goshen, at J. Glines's, on the road to Washington, 

 there is a narrow band of fibrolite rock intimately associated with the 

 porphyritic gneiss. Southward the whole Lempster mountain range is 



