34 PHYSICAL GEOGRAPHY. 



colored, and mica is sparsely disseminated througli the rock. It is usually granitic, so 

 much so that it has always been called granite heretofore. Its most remarkable feature 

 consists in the common east and west strike between Littleton and Cherry mountain. 

 In Whitefield, Mr. Huntington finds the rock tending more north-easterly. Lying be- 

 tween outcrops of porphyritic gneiss, the natural inference is that it is a synclinal, and 

 therefore newer, while the strike indicates a very great antiquity, judging from the same 

 phenomenon elsewhere. The dip is monoclinal, averaging 75° northerly, across Beth- 

 lehem, but anticlinal in Whitefield. If the anticlinal structure is persistent, evidence 

 may be afforded that this peculiar gneiss is older than No. 1. There is a limited out- 

 lier of this rock west of Haystack mountain, another north-west of Mt. Pemigewasset, 

 a third about Big Coolidge mountain in Franconia, and perhaps another south of the 

 east branch of the Pemigewasset. These limited outliers give the idea of a rock 

 newer than No. i. The boulders scattered to the north of Lafayette, in Franconia 

 and Bethlehem, which Professor Agassiz regards as moraines of a local glacier push- 

 ing northerly, are composed of this rock. 



3. Gneiss. The gneiss west of No. i, in Franconia and LandafF, and also to a limited 

 extent east of the Labrador felsite on Tripyramid, is a common variety, and has not 

 yet been referred to any of the sub-divisions recognized elsewhere. 



4. White Mmmtain or Andalusite Gneiss. This is the variety described in previous 

 reports as containing andalusite or staurolite. It occupies the great part of the White 

 Mountain area east of the Saco, making up the bulk of the highest peaks. It reap- 

 pears on equally extended a scale south of Mts. Pequawket, Chocorua, and Whiteface. 

 About Dr. Bemis's residence, or the "Mt. Crawford house" of the map, this rock 

 seems to be isolated, being surrounded by granite. A little of it lies to the north of 

 the Labrador in Albany, and is not represented upon the map. Farther north it crops 

 out in Whitefield, and there is a range apparently from the west flank of Profile moun- 

 tain to Moosilauke. More is found in Thornton, and there is an extensive area of it 

 to the south-west, which is not designated upon the map. The presumption is that the 

 beryl-bearing gneiss east of the Pemigewasset, on the edge of Woodstock and Thorn- 

 ton, is the same rock which extends into Campton. The amount of andalusite in this 

 area is very small. The relative position of the andalusite gneiss remains to be 

 determined. It seems to be newer than Nos. I and 2, but its relations to the 

 granites and felsites are yet to be made out. 



5. Common Granite. The type of this rock appears at the Basin, Pool, and Flume 

 in Franconia, and at Goodrich's falls in Jackson. The constituents are rather coarse, 

 never more than an inch, and usually one fourth of an inch long. The orthoclase is 

 commonly flesh-colored, and is the most abundant ingredient. The quartz is smoky, 

 translucent, and often roughly crystallized. The mica is the least abundant of the 

 three constituents, and is black. The joints passing through this rock are botli hori- 

 zontal and vertical. This rock seems to form the basis of the whole Pemigewasset 

 country, and the areas left blank will most likely be found to consist of this same ma- 

 terial. The first area is that in Franconia, embracing the Profile and Cannon moun- 



