480 STRATIGRAPHICAL GEOLOGY. 



has its greatest width in Enfield, where it is about five miles wide. In 

 Canaan, however, west of Hart's pond, it is not more than two and a 

 quarter miles wide. 



Confining the Lake gneiss to the gneiss of a coarse granular texture, 

 it is narrow in the north part of Canaan, but to the south it becomes 

 wider, and opposite Hart's pond it extends into Orange. South of East 

 Canaan it contracts again, and nearly the whole is crowded into the 

 south-west corner of Orange. The rock at Orange summit is a coarse 

 granular gneiss; and though there are occasionally feldspar crystals, yet 

 the amount of feldspar in the rocks as a whole seems to be much less 

 than is usual in the Lake gneiss. Following this rock, on the east, every- 

 where in Orange we have fibrolite schist. The common gneiss extends 

 along the entire western part of Grafton. It has quite a uniform texture, 

 and is a mile in width along the northern border, and two miles in width 

 on the line of Springfield. Typical varieties of this rock are found, par- 

 ticularly in the vicinity of Grafton pond. It does not extend far into 

 Enfield ; but near the south-eastern corner of the town the northern and 

 western boundary turns to the west along the line of Enfield and Gran- 

 tham. It outcrops in Grantham east of the Butternut pond, where it is 

 coarse and granular. To the south-west, it can be seen on Grass Pond 

 brook, near G. Colburn's. These outcrops are near its north-western 

 limit ; and from near Colburn's the western boundary of the gneiss ex- 

 tends along the east side of Sugar hill, thence southward along the east 

 base of Croydon mountain. East of this line, except the protogene 

 gneiss and quartz, the common gneiss is the only rock in the town. We 

 have not yet determined the exact eastern limit of this rock in Spring- 

 field. The rock in many places has feldspar crystals scattered through 

 it, which sometimes make it difficult to distinguish it from the porphy- 

 ritic gneiss to the east; though where the rock has been examined its 

 foliated texture is always more marked in the gneiss of the west part of 

 Springfield than in the porphyritic. In Sunapee, along through the west 

 part of the town, we find the typical Lake gneiss, and on the west we 

 have the White Mountain schists and gneisses. There are many out- 

 crops of the common gneiss on the road west and south of Ledge pond, 

 on Young's hill, to the south of Sugar river, and in the hill south of H. 

 Crowcll's, near Union church. The strata have an easterly dip, and the 



