LAURENTIAN AXIS TO THE ROCKY MOUNTAINS. 43 
Beds of the Porcupine Hills ; massive sandstones with shales, &e. 
Willow Creek beds; reddish and purplish clays with grey and 
ronde yellowish sandstones. 
(including Judith 
River series). 
/ 
St. Mary River series ; sandstone shales and clays of general grey- 
ish or greyish green colours. 
per sandstones & 
shales (Wapiti 
River group). 
= ni é 4 à SE T 
Yellowish sandstones and shaly beds with a mingling of fresh | Up 
water and brackish or marine molluscs. 
TT: Yellowish Sandstones with some shales, apparently irregular in 
Fox Hills. f ’ : ù 
thickness and character ; molluses all marine. 
? 
Pierre { Blackish and lead-colored shales, with occasional sandstone interca- \ Upper shales (Smoky 
en lation especially towards the mountains. River group). 
Belly River series ; sandstones, shales and sandy clays. Upper) Lower sandstones 
Niobrara. part generally greyish; lower, yellowish, and often banded by ( 
rapidly alternating beds ; fresh and brackish water molluscs. group). 
Lower, shales 
Benton. (Fort St. John 
group). 
The Laramie and Cretaceous rocks are sharply corrugated and folded together for a 
distance of ten to twenty miles from their junction with the Paleozoic rocks of the moun- 
tains, a fact probably in connection with the great fault with downthrow eastward 
which here occurs. East of the belt of corrugation they form a well-marked broad, shallow 
synclinal, the centre of which is occupied by the Porcupine Hills, and thence gradually 
subside to the nearly horizontal attitude which is generally characteristic of the plains. 
The lignites and coals are in the western region not confined to the beds overlying 
the Cretaceous proper, but recur at intervals in the Cretaceous itself. 
Near the base the Laramie is a persistent lignite or coal-bearing formation. 
A few miles north of the 49th parallel, on the St. Mary River, a coal bed of excellent 
quality, eighteen inches in thickness, is found, overlain by a bed holding Corbicula ocei- 
dentalis and Ostrea.. It is described in my report on the Geology and Resources of the 
49th Parallel, pp. 132-172. Another coal outcrop, possibly on the same seam and about a 
foot in thickness, is found on the Upper Belly River. The seam at the Indian farm near 
Pincher Creek, is probably again not far from the same horizon, though perhaps a little 
higher in the series. Coaly streaks occur in the sandstones at the disturbed locality on 
the Oldman River, and a lignite at Scabby Butte may occupy the same position. Further 
north a seam on the Bow at Coal Creek, between Morleyville and Calgarry, and those in 
the vicinity of the Blackfoot crossing, appear to occupy the same horizon. A thin seam 
near the mouth of the Highwood River may possibly be higher in the Laramie and, from 
the character of the St. Mary River sub-division throughout, it is not improbable that 
other coal or lignite-bearing zones may occur locally. 
A seam of lignite coal occurs at the summit of the Pierre on the Bow River, at Horse 
Shoe Bend, while a persistently coal-bearing horizon characterizes its base, and is well 
exposed on both the Bow and Belly Rivers. Lignite coal also occurs in the beds above 
described as underlying the Pierre, and it is possible that further exploration may bring 
to light yet other fuel-producing horizons. 
A further fact of great economic importance is the improvement in quality of these 
fuels on their approach to the mountains. Two causes operate in this sense: First, the 
greater age of the seams in the strictly Cretaceous rocks and the consequent superior degree 
