﻿198 SHALE FORMATION. July, 



the westward of the Hill at the Rapid, but sepa- 

 rated from it by a rivulet, there are horizontal 

 beds of friable sandstone, and beyond them a thick 

 deposit of bituminous shale, which extends north- 

 wards into the high promontory of the Scented 

 Grass Hill, that divides Smith's Bay from Keith's 

 Bay in Great Bear Lake. The excavation of the 

 body of the lake terminates the shale formation in 

 this direction, but more to the westward it can be 

 traced onwards to the Arctic Sea.* 



* Various detailed accounts of some of the tertiary coal beds, 

 and of the elevated spurs wliich cross Bear Lake River, are 

 contained in the Geological Appendix to Franklin's Second 

 Overland Journey ; and the maps on a large scale, given in that 

 work, may be consulted with advantage by any one who wishes 

 to become well acquainted with the topography of the country, 

 or to trace the course of the ridges here described in the text. 



The limestone which forms the body of the hill at the mouth 

 of Great Bear Lake Kiver is blackish grey, full of sparry veins, 

 or brownish-grey and bituminous, associated with calcareous 

 breccia. On the northern flank of the hill, abutting against 

 the vertical beds, there are layers of bituminous shale, some of 

 which effervesce with acids, while others approach in hardness 

 to flinty slate. Underlying the shale, horizontal beds of lime- 

 stone are exposed for some miles along the Mackenzie, and 

 from them there issue springs of saline sulphureous waters and 

 mineral pitch. 



The horizontal sandstone beds, above the Hill at the Rapid, 

 of the same river contain fossils, some of which were considered 

 by Mr. Sowerby to belong to the same age with the English 

 oolitic limestones ; but they require re-examination, and then 

 we may learn whether the very extensive bituminous formation 

 belongs to the Marcellus shale or to the lias beds. 



