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GENERAL OUTLINE OF THE GEOLOGY. 19 
Pee Cretaceous.— 
y No. 5. Fox Hitt Beps.—Grey, ferruginous and yellowish : 
sandstones and arenaceous clays. Marine shélls. 500 feet. 
‘* 4, Fort Prerre Grovup.—Dark grey and blueish 
plastic clays. Marine shells, gypsum and jish 
OES te 2 ea ee Denn se ara 700 ‘ 
Earlier Cretaceous.— 
No. 3. Niroprara Group.—Calcareous marls. Marine 
shells, fish remains, Foraminifera, &c.. arr ape) 
‘* 2. Fort Benton Group-—Dark grey laminated clays, 
‘with some limestone. Marine shells.......... 800 * 
« 1. Daxota Grovup.—Yellowish, reddish, and whitish 
sandstones, and clay, with occasional lignites. 
Marine and some fresh-water shells, and Angio- 
SOIREE U0 or. Bg ene on cig ithe sia» 400 ‘ 
Giving, as an approximate thickness of the formation in that region, 
2,600 feet. 
34. The Lignite Tertiary rocks north of the line are not bounded 
by any great physical features of the country, but adhere closely to the 
upper members of the Cretaceous, and behave as an upper member of 
that formation might be expected to do. Though no doubt originally 
deposited in extensive basin-like depressions of the Cretaceous strata, 
these are now generally found forming slightly elevated plateaus. Denu- 
dation must have acted on these rocks on a vast scale, but they still 
cover an immense area, and contain the greatest stores of mineral fuel 
known to occur in the vicinity of the forty-ninth parallel. The line of 
their eastern edge crosses the parallel near the 102nd meridian, and 
thence appears to pursue a north-westward course, remaining for some 
distance nearly parallel with the edge of the third plateau. Beyond the 
Elbow of the South Saskatchewan, though the same physical feature 
continues to the north, it is not known what relation it may bear to 
the outcrop of this formation, nor has its northern limit been ascer- 
tained. Between the North and South branches of the Saskatchewan 
River there is a great tract of country, the geological features of which 
are still yery imperfectly known, but where it is highly probable, out- 
lyers, if not direct extensions of this Lignite formation will be met with. 
To the west, it appears to extend, at least in some places, nearly to the 
base of the Rocky Mountains. 
35. A thick mantle of sands and clays, referable to the glacial 
period, and to former great lakes, covers almost the entire surface of the 
plains. A geologist may often travel a hundred miles without once 

