38 THE ROYAL SOCIETY OF CANADA 



Montana the Two Medicine formation was traced to the Canadian 

 boundary by Eugene Stebinger^ and identified with the same beds. 



In the mountains and foothills, portions of the lower members 

 of the Belly River series are occasionally found. As these exposures 

 are situated either near or to the west of the farthest advance of the 

 Lower Pierre sea, there is not the same subdivision as on the prairie. In 

 the Allison Creek sandstones of the Crowsnest pass we have apparently 

 continental deposits representing the interval between the Benton 

 and the Upper Pierre that is of the same time period as the Belly 

 River series. Deposits of this nature no doubt were at one time to 

 be found within the area now occupied by the mountains ; but nearly 

 all of this has been removed in the mountain building. Remnants 

 remain above the Benton shales of the Crowsnest pass in the Allison 

 Creek formation and on the head-waters of the Oldman river on the 

 northwest branch, Oyster creek. These latter deposits have been 

 referred to the Laramie in the early reports; but they appear to belong 

 rather to the interval just discussed. 



At the foothill section on Oldman river, the Belly River exposures 

 are very similar to the Allison Creek rocks except perhaps in the fact 

 that the lower part resembles the castellated sandstones on Milk 

 river. On the Highwood river there is apparently near the base a 

 thin section of shales that may represent the Claggett. The thicker 

 member above may, therefore, be correlated with the shore deposits 

 of the Pale and Yellow beds of the Belly River. Northward from 

 Bow river the upper shore deposits are about all that is in evidence. 

 There are also locations in which the Upper Pierre shales may 

 not be found so that the division between the shore deposits of 

 this horizon and of the margin of the Upper Pierre sea may not 

 be evident. This condition is intimated in the section through the 

 Pine River valley made by Dr. G. M. Dawson in 1879. The sand- 

 stones encountered on the eastern slope of the Rocky mountains are 

 thus referred to: — 



2 "While there is no means of arriving at the precise age of most 

 parts of the sandstone series of the Upper Pine river, I see no reason 

 to doubt that it forms the coarse littoral portion of the Cretaceous 

 rocks which spread so widely to the eastward. It seems probable, 

 as more fully detailed elsewhere, that fine shaly materials become 

 increasingly abundant in receding from the mountains, and that the 

 rocks eventually resolve themselves into the subdivisions described 

 below." 



1 Prof. Paper 90, G. U. S. Geol. Survey. 



2 Report of Progress 1879-80, p. 114B. 



