392 G. M. Dawson— Geology of the Peace River Region. 
To the east of these beds of the mountains, and resting quite 
unconformably on them, are the Cretaceous rocks, which, be- 
tween the mountains and the eastern outcrop of the Devonian 
rocks on the Lower Peace, occupy a basin with a width of 
nearly 350 miles, implying a Cretaceous sea of that width. 
The Rocky Mountains have here formed a shore-line in Cre- 
taceous times,—though probably not a continuous one—and 
the Cretaceous rocks along their eastern base are almost en- 
nying the limestones of the mountains. The mountains are 
bordered to the east by foot-hills, in which, on the upper part 
of Pine River, for a distance of about fifteen miles from the 
older rocks, the Cretaceous sandstones are folded and dis- 
turbed. The disturbance, however, gradually diminishes on 
receding from the mountains, and the beds at length become 
flat, or are affected by very slight and broad undulations only. 
Slaty materials increase in importance eastward, and the Cre- 
taceous series eventually resolves itself into the following 
subdivisions—clearly shown on Smoky River—which in the 
annexed table are placed opposite their supposed equivalents 
in Meek and Hayden's and the Southern Rocky Mountain 
sections. 
Upper, or Wapiti River Sandstones, Fox Hill (and Laramie ?) 
Upper, or Smoky River Shales, Pierre. e 
Lower, or Dunvegan Sandstones, Niobrara. #6 
Lower, or Ft. St. John Shales, Benton. 8 
Dakota. 
The correlation, as above shown, is based partly on paleon- 
tological’ evidence, and partly on lithological resemblance. 
That the upper Shales represent the Pierre group is quite clear, 
as a large number of characteristic fossils of this stage have 
been obtained on Smoky River. No fossils have been ound 
in the overlying sub-division. .The fossils of the lower Sand- 
stones are peculiar, consisting chiefly of fresh-water and estua- 
rine mollusks and land plants. In the lower Shales the- most 
characteristic form is a large Ammonite resembling Ammonites 
(Prionvcyclus) Woolgari, but, according to Mr. Whiteaves, spe- 
cifically distinct. The Peace River country being so remot 
from the typical region of the Cretaceous sub-divisions, it is not 
intended to insist on their precise synchronism with the 
groups here mentioned, but merely to point out a probable 
general equivalency. No beds so low as the Dakota group 
