﻿1861.] 



HECTOK ROCKY MOUNTAINS, ETC. 



437 



in these two districts, but also the direction in which the water- 

 courses affect the principal descents, and the manner in which the 

 lakes in each of them are arranged, all indicate a different direction 

 of the elevating and disturbing force ; in other words, two different 

 axes of dislocation. 



These seem to converge towards the south, including an angle of 

 about 25° ; the eastern one being directed from the north-east to 

 south-west, while the western one lies much more nearly north and 

 south. In each of these there is a great central district where 

 nothing but rounded bosses of granite are seen occurring as ridges 

 and islands, which rise little above the level of the flooded country 

 in which they occur. On either side of these two granitic districts 

 metamorphic rocks are ranged with great irregularity as regards 

 their order and dip, but still, on the whole, preserving their direction 

 very consistently with the bearing of the axes to which they respect- 

 ively belong. There are besides many minor outbursts of granite 

 occurring as dykes and intrusions, but they do not seem to interfere 

 with the above-mentioned general bearings of the country. 



From this cause, in crossing the district between Lake Superior 

 and Rainy Lake, the summit-level is reached by an abrupt and rapid 

 ascent in a direction at nearly right angles to the main eastern axis. 

 Then follows a long traverse, almost along the summit of that axis, 

 and then an abrupt but comparatively short descent to Rainy Lake, 

 again at right angles to the axis. 



The first great step in the ascent from the east is made at the 

 Kakabica Falls, where, from a succession of faults which mark the 

 commencement of the more highly metamorphosed rocks, a sudden 

 elevation is effected, the summit-level of which is 179 feet above 

 Lake Superior at Fort William. 



About one mile below the fall a fine section is exposed in the 

 form of a cliff 130 feet high, crossing the country from north-east to 

 south-west, consisting of a dark argillaceous schist in thin fissile beds, 

 from 1 to 2 inches in thickness, very much jointed, and having 

 many small veins of quartz, and sometimes calc-spar, included both 

 in the lines of bedding and in the joints. These beds are quite 

 horizontal, and through their whole thickness the river has cut its 

 way back to the present position of the fall in a manner similar 

 to that in which the river-bed below the Niagara Falls has been 

 formed. 



They are supposed to belong to the Huronian series, a system which 

 is largely developed on the shores of Lakes Superior and Huron, 

 resting unconformably upon the Lauren ti an series, and having, ac- 

 cording to Sir W. Logan, a thickness of 12,000 feet. This large 

 system, that has not as yet yielded any fossils, and always underlies 

 the Silurian, has been considered to represent the Cambrian. 



On the Paver Kaministoquoiah above the fall at Friar's Portage 

 the strata have an almost vertical position; and a little further on, at 

 Lower Island Portage, are found to be dipping at an angle of 40° to 

 south-south-east, and to be changed in character, having mica deve- 

 loped in them, and also a great abundance of quartz-veins. Imme- 



