282 ROYAL SOCIETY OF CANADA 



the exception of attempts to work the anthracite on the south coast of 

 the island, which, however, have not been productive of economic results 

 beyond the sinking of a few shallow pits in prospecting work in connec- 

 tion with the development of the great seams of bituminous coals of the 

 interior, but little work has been attempted. This field promises to be 

 of great value in the not distant future. 



The occurrence of these several varieties of ooal in rocks of prac- 

 tically the same geological horizon is interesting, since it is probal^ie that 

 at one time all these newer coals existed in the form of lignite. Thus 

 it has been pointed out by Dr. (1. M. Dawsion that as we approach the 

 foot-hills from the plains, and thenoe continue westward into the moun- 

 tain range at Crowsnest and at Banff, the percentage of water in the 

 lignite gradually diminishes and the coal gradually passes through 

 lignitic coals into the bituminous variety and thence to semi — and to 

 true — anthracite, the change being more marl^ed in all cases as the con- 

 taining rock formation is more and more uplifted and pressed together 

 or approaches the vertical. It would appear therefore that the altera- 

 tion'of the coals is to a large extent due to heat induced by pressure dur- 

 ing the epoch of mountain making, and when the uplift of the Eocky 

 mountains was being effected. For some miles east of the range itself 

 there is a series of folded and titled beds in which the lignitic character 

 of the contained coal has practically disappeared. 



The change in the character lof the coals may also, to some extent, 

 be due to the relative position of the several seams seen in the section, 

 since the higher grade coals may represent beds from the older or lower 

 portion lof the Cretaceous formation. The lignite of the North Sas- 

 katchewan belongs to the Laramie or upper part of that system of rocks, 

 but here the strata are comparatively undisturbed. The difference in 

 the character of the coals does not however depend entirely upon the 

 geological horizon, since in the interior basins of British Columbia, many 

 of the Tertiary coals are highly bituminous instead of lignitic, while on 

 Queen Charlotte island, the Cretaceous coals range from high grade bitu- 

 minous to broken and shattered anthracite, largely through the alteration 

 induced by rock imovements, but also probably to some extent by later 

 intrusions of igneous rocks in the immediate vicinity. 



The thickness of the coal-bearing strata along the eastern side of the 

 Eocky mountains aggregates several thousands of feet. The sections 

 exposed in the vicinity of the Crowsnest and near Banff along Ûie val- 

 ley of the Bow river, shew the presence of numerous coal seams some of 

 which are of great thickness. In a section published by Mr. J. Mc- 

 Evoy, (see Eept. Geol. Sur. 1900) the total thickness of the coal-bearing 

 formation exposed along the Elk river amounts to 4,736 feet, and the 



