514 



THE NATIONAL GEOGRAPHIC MAGAZINE 



Photo by Charles D. Walcott 

 WAITING ON THE BURGESS TRAIL UNDER MOUNT WAPTA 



MIDDLE CAMBRIAN Feet 



Eldon formation (siliceous and arena- 

 ceous limestones) 2,700 to 2,800 



This is the formation that caps Mount 

 Stephen and many of the higher 

 mountains. 



Stephen formation (limestones and 

 shale) 640 



Cathedral formation (arenaceous lime- 

 stones) 1,595 



Total Middle Cambrian 4,963 



LOWER CAMBRIAN Feet 



Mount Whyte formation (limestones 



and sandstones ) 390 



Saint Piran formation (sandy shales 



and sandstones) 2,705 



Lake Louise formation (siliceous 



shale) 105 



Fairview formation (sandstones) 1,324 



Total Lower Cambrian 4,5-24 



SUMMARY Feet 



Upper Cambrian 3,590+ 



Middle Cambrian 4,963 



Lower Cambrian 4,524 



Total thickness of Cambrian section. 13,077-h 



Beneath the old Cambrian sea-beach 

 now forming the base of the Fairview 

 formation there is a great series of sand- 

 stones and sandy shales of quite a differ- 

 ent character. These rocks formed the 

 land area which was submerged by the 

 Cambrian sea that wore them away more 

 or less in its advance over the continent. 



These older rocks are supposed, owing 

 to their character and the absence of 

 marine fossils, to have been deposited 

 in fresh water. They are referred to a 

 series called the Algonkian, and are di- 

 vided into two formations : 



Feet 



Hector formation (sandstones and 

 shales — gray, black, greenish, purple in 

 color) total thickness.. 1,302 



Corral Creek formation (sandstones)... 1,320 



THF WASTING AWAY OF THF MOUNTAINS 



The breaking down of the mountain 

 summits by the action of rain, frost, and 

 ice, so as to form strong pyramids and 

 ridges, is constantly going on. This is 



