NATURAL HISTORY AND PHYSIOGRAPHY OF NEW BRUNSWICK. 245 



in spots, is certainly pre-glacial as a whole. By its extension back 

 the lake was doubtless robbed from Mamozekel waters, into which it 

 once probably flowed along the low valley now occupied by Bald 

 Mountain Brook. 



The geology, as traced in general by Bailey, Ells, and Chalmers, is 

 shown upon the geological map. All the large hills about the lake 

 and its entire eastern end are of Pre-cambrian felsites, but Silurian 

 rocks appear at the western end. One very remarkable fact about the 

 geology of the lake, first referred to by Bailey, is the presence of the 

 little island of slate, Visitor's Island, completely surrounded by felsites. 

 It may represent the remanant of a tongue of Silurian rocks extending 

 along the bed of the lake to this point, which would give a great age 

 to this valley. The island slopes down so steeply and abruptly on the 

 north side as to suggest a fault running along the axis of the lake. 

 Were it not for its relatively enormous size, 100 feet long by 50 wide, 

 one would be tempted to view it as simply an enormous boulder. But 

 this is but one of the very many attractive problems awaiting solution 

 in this region. 



Natural History. No study whatever has yet been made of the 

 zoology of the region, and but little of the botany. 



The Neighboring Highlands. To the north of the lake the moun- 

 tain ranges appear irregular, and I have not tried to work out their 

 particular arrangement. On the southern side, however, they are as 

 follows : Sagamook is not an isolated mountain, but is the northern 

 most of three parallel ridges forming together a great island or plateau 

 of felsite (see map, Fig. 6, and also the map accompanying the next 

 note, Fig. 13). This plateau has Nictor Lake on the north, the deep 

 valley of Caribou Brook and the portage on the east, Bald Mountain 

 Brook valley on the west, and a valley between Nepisiguit Lakes and 

 the Mamozekel on the south. Sagamook is separated from the next 

 ridge, Mount Head, by a valley not over 300 feet deep, while a some- 

 what deeper valley lies between Head and Mount Carleton. The 

 appearance of Head and Carleton from Sagamook is shown by Fig. 11. 

 Mount Carleton is over 100 feet higher than Sagamook, and is easily 

 recognized by its bold, bare, saw-like top. Still farther to the south- 

 ward one can see the summit of Mount Winslow, not a part of this 

 plateau (Fig. 12). On the westward of the valley of Bald Mountain 

 Brook runs a fine range of hills south-west. It begins at Nictor Lake 



