GEOLOGY OF THE WHITE MOUNTAIN DISTRICT. 20$ 



In 1861-62, when engaged on the geological survey of Maine, I had occasion to 

 traverse the borders of Moosehead lake, then the country westward to the boundary 

 along the west branch of the Penobscot, and the Canada road from the Forks to the 

 Chaudifere.* The upper section showed two Huronian areas overlaid by two bands of 

 clay slates, the latter most likely of Upper Silurian age ; the other, along the Canada 

 road, exhibited at first strata, most likely Upper Silurian in age (possibly Huronian), 

 overlaid by a band of Oriskany sandstone, to the west of which appeared, first, granite 

 ledges, then the Upper Silurian strata, followed by the Huronian again extending into 

 Canada. f The numerous fossils obtained at the first visit were named by Billings, of 

 Montreal, who recognized in them characteristic species of the Oriskany sandstone. 

 Subsequently, the finding of the Fitcoides Cauda-Galli made us believe the representa- 

 tive of the Cauda-Galli grit appears on Moosehead lake. J 



In the hope of gaining some additional knowledge of the rocks of this section, par- 

 ticularly in determining their extreme limit, J. H. Huntington spent a few weeks, in 

 1872, in traversing the country from Moosehead lake westward. He found the felsite 

 of Mt. Kineo in a high ridge to the south-west, on the opposite side of the lake, per- 

 haps dipping north-westerly. On the west shore of Lake Brassua, probably two miles 

 from the southern extremity of the lake, there is an outcrop of a dark colored shale ; 

 and immediately north there is another outcrop of felsite. If we follow the line of the 

 strike of the felsite of Lake Brassua four miles S. W. of Parlin pond, we find Bald 

 mountain, with the ridges running W. and N. E., to be composed of a rock similar to 

 that of Mt. Kineo. So it is possible that the rock may be continuous between these 

 two points. See Plate IV for a generalized section across these formations. 



Perhaps three fourths of a mile above Brassua lake the rock is a ferruginous sand- 

 stone, cut by numerous joints, and the strata dip S. 20° E. 10°. The fossils are quite 

 numerous, and some of them very distinct. The following are the genera : Avicula, 

 Modiolopsis, Orthis, Leptoccelia, FlabellUes, Spirifera, Fiicoid. For the next three miles 

 the rock is a very hard, light brown sandstone, without fossils. At the mouth of Stony 

 brook, a point some two miles from Long pond, he found another fossiliferous band of 

 rock. There the sandstone is compact, but it frequently contains fragments of slate 

 an inch or more across. Thus it is evident that this rock is newer than the slates on 

 either side. The dip of the rock here is S. 31° E. 2°. The fossils are not so numerous 

 as in some other places, but they seem to be more generally distributed through the 

 rock. This is the only locality where the coral Favosites is found. From this point to 

 Long pond the outcrop is the same compact brown sandstone that is seen in several 

 places between the Little Brassua and the mouth of Stony brook. The first outcrop 

 of rock on the south shore of Long pond contains concretions of iron pyrites, but no 

 fossils. About half-way up the lake the strata run diagonally across, and there are 

 several outcrops of fossiliferous rock at some distance from the shore. Six miles from 

 the outlet on the south shore there is quite an extensive outcrop of rock, and an abun- 



* Second Annual Report,-^. ■ii,l,\ZtT,. f/^., p. 283. J/^., p. 331. 



