172 



Resume of Section. 



Feet. Metres. 



Cretaceous 4,350+ i ,326 



Jurassic 1 ,500+ 457 



Permian 1 , 400+ 427 



Carboniferous 5 , 800+ 1 , 768 



Devonian 1 ,800+ 548 



Devonian (?) 3 , 700+ 1 , 127 



Silurian 1 , 850+ 563 



Ordovician 7 , 740+ 2 , 360 



Upper Cambrian 9,815+ 2,992 



Middle Cambrian 4.963 1,513 



Lower Cambrian 3,800+ 1,158 



Pre-Cambrian 5,910+ 1,802 



Total 52, 628+. 16, 041 + 



PRE-CAMBRIAN. 



The Pre-Cambrian series is distributed along the floor 

 and sides of Bow river valley from the base of Castle 

 mountain, where it becomes faulted off against the younger 

 Paleozoic rocks, to the head waters of the Bow river. 



The contact between the Pre-Cambrian and the Cam- 

 brian is seldom exposed. It was examined at three locali- 

 ties. At one exposure in Bath Creek valley, near the 

 summit of the Rocky mountains, the contact is a conform- 

 able one, while in two other localities in which the 

 contact was exposed, there is a noticeable unconformity 

 between the beds of the two systems. In one case the 

 Pre-Cambrian shales were dipping 31 degrees S. 55 W., 

 and the Lower Cambrian quartzites had a dip of 35 degrees 

 S. 5 W. 



The rocks in the Pre-Cambrian series, with the three 

 lowest formations of the lower Cambrian, were formerly 

 called the 'Bow River Group' by McConnell [2, p. 29]. 



Corral Creek Formation. — This formation includes 

 the lowest beds exposed in the Rocky mountains, along 

 this section. This series consists of gray sandstone under- 

 lain by a coarser quartzitic sandstone, with an arkose-like 

 conglomerate at the base. The lowest beds are exposed 

 in a railway cut two miles (3,249-2 m.) east of Laggan 

 station. This rock is made up of small pebbles and 

 grains of quartz, and angular crystals of white and pink 

 feldspar. The cement is made up of finer material of 



