GEOLOGY OF THE WHITE MOUNTAIN DISTRICT. I3I 



These schists that come near or in contact with intrusive rocks are 

 everywhere nearly vertical. 



Intrusive rocks. In the south part of Jackson, and also running diago- 

 nally across the town, there are bands of intrusive rocks. On Wildcat 

 branch, where the road from A. Chesley's crosses the stream, there is 

 a granitic rock composed very largely of feldspar. The rock has the 

 general appearance of the Albany granite, which outcrops on Ellis river, 

 near J. Rogers's, and a large proportion of this rock is also feldspar. 

 An outcrop of a similar rock was seen at C. Littlefield's, and it extends 

 to Rocky Branch. At Jackson falls the Albany granite is found, with 

 finer-grained varieties. It outcrops in several places on the ridge be- 

 tween Tin and Thorn mountains. It also forms the summit of the latter. 

 On the east branch of the Saco, just below McMellin & Towle's saw-mill, 

 the Albany granite comes in contact with the slates of Mt. Pequawket. 

 Along the line of junction the slate forms a breccia, and the feldspathic 

 material of the granite furnishes the cementing material. It is one of 

 the most interesting localities in this section of the state. There is an 

 area of the Conway granite that has its most northern and eastern out- 

 crop on Copp's hill in Jackson. It extends south-west, and forms the 

 southern part of Iron mountain, and it is in this rock that the iron ore is 

 found, though it is immediately associated with a rock composed chiefly 

 of feldspar, that reminds one of the Chocorua granite. If the granites 

 that are composed so largely of feldspar are more recent than the Con- 

 way, as seems evident from their relations elsewhere, those that we 

 find in the valley of Rocky Branch, between the high ridges of the Con- 

 way, must have been formed in a depression, or the intruding mass had 

 not sufficient force to make its way through and overflow the preexisting 

 rocks. J. H. H. 



Areas of Montalban in Pemigewasset. 



These areas are six in number: — First, the region about Bemis and 

 Duck Pond mountain; second, a small patch between Deer mountain 

 and Chocorua; third, a somewhat larger territory between Passaconna- 

 way and Tripyramid, on the east branch of Sabba Day brook ; fourth, a 

 considerable tract along the Pemigewasset river in Lincoln, Woodstock, 

 and Thornton, being a spur from a great development of this formation 



