Section IV, 1922 [97] Trans. R.S.C. 



The Historical and Structural Geology of the Southernmost Rocky 



Mountains of Canada^ 



By J. D. Mackenzie, Ph.D. 



Presented by W. H. Collins, B.A., Ph.D., F.R.S.C. 



(Read May Meeting, 1922) 



Introduction 



The Rocky mountains of Canada south of the Crowsnest pass 

 are a region of much geologic importance. Not only do they contain 

 coal deposits of great magnitude, but the geologic structures exposed 

 present features of much significance. The amount of information 

 at present available on the geology of this region is not large. In 

 a few restricted areas within it, detailed work has been done; in other 

 portions reconnaissances have been made; but much of it has yet to 

 echo to the geologist's hammer. My own introduction to the region 

 was in 1912 when I spent three delightful months studying the coal- 

 bearing area drained by some of the southern tributaries of the Oldman 

 river in southwest Alberta, for the Geological Survey, Canada. 

 In the same year a short reconnaissance was made into the Flathead 

 valley in the company of Dr. D. B. Dowling. In 1914 a short time 

 was spent in examining a small area in the lower Flathead valley, well 

 within the mountains themselves. 



Many of the structural relations observed in this region were so 

 puzzling that an explanation of their origin was not attempted in 

 my reports on the localities studied. After consideration of the 

 available evidence, an hypothesis serving to explain how the observed 

 structures may have arisen has been formulated and that hypothesis 

 is elaborated in this paper. There are too many facts still to be 

 learned to hope that those in hand furnish a complete explanation. 

 However, enough is known to venture a preliminary one, which I 

 think at least contains the germ of the truth. 



Several of the men who have worked in this region have afforded 

 me the advantage of discussion by correspondence or otherwise, and 

 I wish to acknowledge my indebtedness in this respect to Messrs. 

 D. B. Dowling, F. H. McLearn, J. R. Marshall, Bruce Rose, S. J. 

 Schofield, and Bailey Willis. 



^Published by permission of the Director, Geological Survey, Ottawa. 

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