226 
Canadian Af/riculture. 
" The buffalo is now extinct on these plains ; but abundant traces of its 
fomer presence exist in the rubbing-stones, wallows, deeply-worn j^aths, and 
bleached skeletons, and at one place on the Bow I'iver we saw a large deposit 
of bones covered with earth washed down from above, and apparently indica- 
tive of the destruction of a herd from some natural cause, perhaps unusual 
cold and heavy snow. The latter, when followed by thaw and frost, pro- 
ducing a hard icy crust, has sometimes proved destructive to cattle on the 
higher plains." * 
The third steppe, which has a width of 450 miles on the 
49th parallel, narrows rapidly as it is traced northwards. 
" The geology of our great Xorth-West, like our vast plains and immense 
rivers, is on a magnificent scale. To the eye of the geologist a grand vision 
aj^jxiars as he contemplates the marvellous panorama that rolls before him, 
portraying the geological features of the countrj' h'ing between the Laurentiau 
rocks to our east, and the lofty mountains of the west. The former, represen- 
tatives of the first rocks to triumph over the universal waters of primeval 
days, and the latter belonging to a jieriod near the summit of the geological 
series. Between these great natural boundaries we see stretching before us 
the three vast prairie-steppes of the Xorth-West, rising in succession above 
each other and distinguished by characteristic physical features." f 
Underlying nearly the whole of the prairie region are clays, 
sandstones, and limestones of Cretaceous age, or (in the more 
western parts) shales and sandstones of the Laramie % or Lignitic 
Tertiary group, the age of the latter being probably interme- 
diate between that of the Cretaceous and of the Eocene of 
England. The nearest parallel to be found at home is afforded 
by the greater part of the counties of Norfolk and Suffolk, 
where Cretaceous rocks (chalk in this case) are overlaid by 
glacial detritus or drift. The alluvium of the Red River 
valley rests upon strata of Silurian age. 
Though the prairie soils are largely either of glacial or of 
alluvial origin, they are not the product exclusively of such 
agencies : — 
" Long continued growth and decay of vegetation upon a land surface not 
only promotes disintegration of the superficial rock, but produces an organic 
residue, the intermingling of which with mineral debris constitutes vegetable 
soil. Undisturbed through long ages, this process ha.s, under favourable con- 
ditions, given rise to accumulations of a rich dark loam. Such are the 
' regur,' or rich black cotton soil of India, the ' tchcrnayzem,' or black earth, 
of Kussia, containing from 6 to 10 per cent, of organic matter, and the deep 
fertile soil of the American prairies and savannahs. These formations cover 
plains many thousands of square miles in extent." § 
Nor must the effects of animal life be overlooked : — 
" Burrowing animals, by throwing up the Foil and subsoil, expose these to 
* ' Observations on the Geology of the Line of the Canadian Pacific Railway.' 
By Sir J. W. Dawson, F.K.R. ' Quart. Jour. Gcol. Soc.' 1884, p. 387. 
"t 'Geology of tlic Red River Valley.' By J. Iloycs raiiton, 51. A. 
i'A term derived from Laramie City, in the State of Wjoming, hit. ■12'^. 
§ * Text-book of Geology.' By Archibald Geikic, F.R.S., p. 458. 
