266 APPENDIX TO PARTS I AND II. 



are large areas of granite ; but its greatest development we find on Observatory and 

 Aziscohos mountains, and there is quite an extensive outcrop in No. 4, R. i, on the 

 south-west side of a hill north-west of the upper dam. The top of Bald mountain, 

 between Rangeley and Moosetocmaguntic lakes, except its very summit, is composed 

 of this same coarse granite. The way in which the schist is caught shows better the 

 intrusive character of the Conway granite than any other example we have seen. 

 Fig. 64 shows clearly this feature. To the left, on the border of the lake, we have 

 the schist with an easterly dip ; and as we ascend the mountain the granite suddenly 

 appears, and extends almost to the very summit, which is crowned with the same 

 kind of schist as that at the base ; but in it is a well defined band of granite, about 

 six feet wide, cutting it so sharply that the dip, which is westerly, is essentially the 

 same as that of the mass on either side. South-east of Moosetocmaguntic lake, in 

 township D on the head waters of Swift river, there is a band of granite, but it is a 

 finer variety than those found northward. 



Diorite. The most extensive outcrop of intrusive diorite found in New England has 

 its southern limit near Gull pond, and outcrops are found for more than four miles to 

 the north. South-east of Kennebago lake it forms a sharp mountain ridge, which rises 

 more than 600 feet above the lake. The rock is generally a mica diorite, and it often 

 contains garnets. On the southern limit of this diorite are fragments of schist ; and it 

 probably also penetrates the Paleozoic strata in the vicinity of Kennebago lake. There 

 are many dykes of diorite in Rangeley immediately north of the lake, and the rock re- 

 sembles the great outcrop northward, except that there is more hornblende and fewer 

 garnets. 



Felsite. The summit of the diorite ridge south-east of Kennebago lake is chiefly a 

 compact feldspar ; and one variety contains a few garnets and a little mica. This forms 

 great clifts near the summit of the ridge. 



APPENDIX G 



THE ATLANTIC SYSTEM OF MOUNTAINS. 



Want of time will prevent us from preparing a chapter upon the elevation of moun- 

 tains and the occurrence of earthquakes, as promised in the preface to Volume I. In 

 its stead, I will describe in greater detail the suggestion made upon page 6, Volume II, 

 in regard to the distinctive features of the Atlantic system of mountains. I hardly 

 need say there is a world-wide difference between the views of the age of mountains 

 expressed in these reports, and those entertained by the metamorphic school of geolo- 

 gists. For this reason, it is important to set forth the correct history of the whole 



