CAMBRIAN GEOLOGY AND PALEONTOLOGY 



No. 7.— PRE-CAAIBRIAN ROCKS OF THE BOW RIVER 

 VALLEY. ALBERTA, CANADA 



By CHARLES D. WALCOTT 



(With Three Plates) 



Contents 



rage 



Introduction 423 



Topography of Bow Valley 424 



Basal Cambrian Rocks 425 



Unconformity between the Cambrian and the pre-Cambrian Rocks 426 



Pre-Cambrian Rocks ; 427 



Correlation of Bow Valley pre-Cambrian Rocks with those of Northern 



Montana 430 



Resume 431 



Illustrations 



Plate 45, Fig. i. Panoramic view looking across Bow Valley 424 



Fig. 2. View of Fort Mountain from the west 424 



Plate 46. Fig. i. View of ridge south of Ptarmigan Lake 426 



Fig. 2. Panoramic view from the south slope of Fort Mountain. . 426 



Plate 47. Map of a portion of Bow Valley, .-showing approximate 



area of pre-Cambrian strata 428 



INTRODUCTION 



During the stimmer of 1909 I continued my study of 1907^ on 

 the Cambrian formations of the main range of the Rocky Mountains 

 on the line of Bow Valley, in Alberta, with the view of discovering 

 a base to the Fairview formation of the Lower Cambrian, and. if 

 possible, of finding fossils in the shales and sandstones beneath that 

 formation in the Bow Valley. When measuring the Cambrian sand- 

 stone on the northeast slopes of Mount Fairview and Saddle Moun- 

 tain, about 2.5 miles southwest of Laggan, a fine quartz conglomerate 

 about 100 feet in thickness was found, and below it a gentle, forest- 



^ Smithsonian Miscellaneous Collections, vol. 53, No. 5, 1908, Cambrian 

 Sections of the Cordilleran Area, pp. 204-217. 



Smithsonian Miscellaneous Collections, Vol. 53, No. 7 



423 



