NEW HAMPSHIRE AND VERMONT. 



59 



3. The New Hampshire formations are believed to possess thickness as follows : Helderberg, 

 500 feet; Calciferous Mica Schists, 4,800 feet; Coos Group, 7,300 feet; Cambrian Slates of Connec- 

 ticut Valley, 3,000 feet; Kearsarge Group, 1,300 feet; Rockingham Mica Schists, 6,000 feet; Merri- 

 mack Group, 4.300 feet; Huronian, 12,000 feet; Montalban, 10,000 feet; Lake Winnepisseoga 

 Gneiss, 18,000 feet; Bethlehem Gneiss, 11,300 feet; Porphyritic Gneiss, 5,000 feet. 



Vermont. 



4. An interesting area has been traced from Lyme, N. H., to Windsor, Vt., about 30 miles long. 

 Portions of it have been removed by the wearing action of the Connecticut. ^ It appears to have 

 been deposited by a powerful current derived from the melting of the glacial sheet prior to the 

 accumulation of terraces. 



5. The centre of the anticlinal axis of the Green Mountains. At least eight of the general 

 sections of the Vermont survey show this feature of structure, proving this formation to be older 

 than the Huronian adjacent upon both sides. This structure was denied by Logan for the continu- 

 ation of the Vermont rocks in Canada in his generalizations, but the descriptions of the rocks 

 confirm the views of the Vermont geologist. 



