GEOLOGY OF THE WHITE MOUNTAIN DISTRICT. I49 



by a breccia; this in places passes into a homogeneous red porphyry, the 

 composition of which is sihca, 64.20, akimina, 8.80, iron oxide, 12.60, mag- 

 nesia, 2.37, Hme, 3.50, soda, 4.24, potash, 6.25. On Swift river, near the 

 mouth of Little Deer brook, the rock is the Albany granite. 



On a ridge west of Little Deer brook, perhaps two miles north of Swift 

 river, there is a schistose rock similar to the narrow band found on the 

 brook; and then west we find the Albany granite, and the outcrops are 

 numerous on the west branch of Little Deer brook. East from Little 

 Deer brook, nearly to the Saco, except for two or three miles along Swift 

 river, the rock is everywhere a breccia and feldspar-porphyry. The 

 whole of Mote Mountain range presents a fine field for the study of these 

 rocks, both from the numerous outcrops that present it in so many dif- 

 ferent phases, and also from the fact that the forests along the whole 

 range have been recently almost entirely destroyed by fire. The most 

 southerly outcrop of this rock is in Albany, on Dry brook, near the house 

 of B. Farnum. Although here it is a breccia, yet there are distinct crys- 

 tals of feldspar and particles of vitreous quartz, making the rock more a 

 feldspar-porphyry than a breccia. From near Farnum's there is a foot- 

 path to the summit of the south peak of Mote mountain. On this path, 

 perhaps a mile from Swift river, the rock is composed principally of dis- 

 tinct fragments of schist, compact feldspar, and c^uartz. Half a mile 

 above this outcrop there are places where the rock is so entirely changed 

 that the marks of the rock as a breccia are almost obliterated, and we 

 have a rock, the base of which is feldspar, and in this there are orthoclase 

 and triclinic feldspars and quartz. Above this the rock is quite uniform, 

 consisting of a feldspathic base, in which there are fragments of schist, 

 and always crystalline particles of feldspar and quartz. This is the rock 

 of the south peak of Mote mountain and the ridge north until we come 

 to the steep ascent half a mile south of the north peak. Here the frag- 

 ments of schist become more frequent and more distinct. On the north 

 peak of Mote mountain the fragments of schist are larger and more nu- 

 merous than we have found them elsewhere, some of the largest frag- 

 ments being a foot across, and in general immediately on the summit the 

 fragments are less firmly cemented together than they are on the ridge 

 either north or south. The largest fragments are andalusite schist ; be- 

 sides, there are a few fragments of quartz and feldspar. The rock seems 



