FERNIE SHALES AND KOOTENAY FORMATION 677 



and in places farther south all the Cretaceous up to the Belly River for- 

 mation. This basal group of unclassified limestones may serve also, for 

 this discussion, as a starting point to describe the overlying Jurassic and 

 Cretaceous formations, since it marks the transition from a great thick- 

 ness of limestones to a great group of shales and sandstones. 



Fernie Shales 



The first of the formations overlying the Devono-Carboniferous lime- 

 stones was correlated by Cairnes with the Fernie shales. This formation 

 received its name from the type locality near Fernie, British Columbia, 

 where it varies from a thickness of 650 to 3,000 feet. In the Banff area, 

 west of Calgary, on the Bow River, it is assigned a thickness of 1,4-00 feet. 

 Cairnes, on the Elbow River, worked out a thickness of 315 feet, which 

 has been checked by the author on the Elbow River at the south end of 

 Moose Mountain. 



In the Bow River section, near Banff, Alberta, the Fernie shales are 

 described by various writers as resting on a formation called the Upper 

 Banff shales — a brown, calcareous and arenaceous formation, with inter- 

 bedded thin layers of sandstone. This formation has been generally ac- 

 cepted as Permian in age, but recently this has been questioned. What- 

 ever its exact age may be, it appears to be reasonably certain that there 

 was a long interval between the deposition of the Upper Banff shale and 

 the Fernie shale, which is generally accepted as Upper Jurassic in age. 



Cairnes correlated the shales on the Elbow River with the Fernie shales 

 on some paleontological evidence and from their position below a forma- 

 tion which was clearly of Kootenay age. 



It is probable, from the varying thicknesses given above of the Fernie 

 shales, the general overlap relations, and the unconformity between the 

 Fernie shales and the Upper Banff shales in the Bow River Valley, that a 

 marked unconformity also exists at the base of the Fernie shales on the 

 Elbow River. 



Kootenay Fokmation 



This formation, the great coal-bearing series of the Crowsnest Pass, 

 received its name also from the type locality near Fernie, British Colum- 

 bia. It is formed everywhere of brackish and fresh- water sediments. In 

 the type locality the earliest strata of this formation have developed a 

 flora of Jurassic characteristics, and these beds are generally regarded as 

 at least not younger than Middle Comanchean. 



