676 



J. H. SINCLAIR CRETACEOUS OF ALBERTA, CANADA 



seen that there was a certain resemblance here to the famous Cretaceous 

 section of the Upper Missouri River in Montana. 



About 1907 Cairnes, of the Geological Survey of Canada, took up in 

 detail the mapping of about 1,500 square miles, located 25 miles south- 

 west of Calgary, and was successful in recognizing the presence of forma- 

 tions unquestionably identical with some of the formations of the Upper 

 Missouri River. The finding of part of the Upper Missouri section led 

 to the adoption of the whole, and this recently has been found to call for 

 certain modifications. 



The succession for the Elbow River and Sheep River as worked out by 

 Cairnes and generally accepted, in 1914, is as follows: 



Tertiary. 



Cretaceous. 



Jurassic. 

 Devono-Carboniferous. 



Paskapoo formation. 



Edmonton formation. 

 Bearpaw formation. 

 Belly River formation. 

 Olaggett-Benton formation. 

 Dakota formation. 

 Kootenay formation. 



Fernie shales. 

 Not subdivided. 



Sandstones. 



Sandstones. 

 Marine shales. 

 Sandstones. 

 Marine shales. 

 Sandstones. 

 Sandstones. 



Marine shales. 

 Limestones. 



This was the succession as defined by D. D. Cairnes in his paper, 

 "Moose Mountain district of southern Alberta," Geological Survey of 

 Canada, 1907. 



At the time of the visit of the writer of the present paper, in 1914, Mr. 

 D. B. Dowling and Mr. S. E. Slipper, of the Geological Survey of Can- 

 ada, were engaged in a detailed study of the area adjoining Cairnes' dis- 

 trict, and simultaneously with the author recognized the necessity for 

 certain modifications of the previously accepted column. 



In order to understand the geology of this district, it is as well to fol- 

 low Cairnes' method and, beginning with his lowest formation, discuss in 

 turn the various formations from the oldest to the most recent. In this 

 way the facts on which the present paper is based may be more clearly 

 presented. 



Cairnes began his detailed classification at the top of a thick, massive 

 series of limestones which he did not attempt to study closely and which 

 he grouped under the general name "Devono-Carboniferous." This basal 

 group is seen in but a small corner of his area and the area discussed 

 in this paper. Southward, both on the Moose Mountain area and in the 

 district described in the present paper, the Lewis thrust has caused the 

 concealment by these massive limestones of the Eernie shales, Kootenay, 



