242 THE CANADIAN NATURALIST. ["^oL vil.- 



thia and irregular, and the coals themselves contain an excess of 

 moisture and much ash and sulphur. In this western country 

 the sandstones and mud rocks, usually associated with coal, are 

 gradually replaced by limestones, indicating deeper water and 

 conditions unfavourable to the formation of coal beds, as pointed 

 out bv Professor Hall. 



Poor as these western coal-bearing rocks are, they labour under 

 the additional disadvantage of being in great part covered by a 

 newer formation, the Cretaceous; and where the Carboniferous 

 formation again comes to the surface along the Rocky Mountain 

 re<>ion of uplift, to the west of the great plains, it has not beea 

 found to contain so much as a single seam of coal, but is repre- 

 sented by massive limestones, shewing deposit in deep ocean 

 water, and so far removed from land that it is rare to find in 

 them even a fragment of any of the plants which were growing 

 so luxuriantly in the swamps and deltas of the eastern half of the 

 continent at the same time. Just where the coal of the recog- 

 nized formation fails, the luxuriant growth of timber of the east 

 also comes to an end, and the country assumes that prairie cha- 

 racter which persists with scarcely a break to the foot of the 

 Rocky Mountains. The bare rolling grassy hills and plains, 

 though in many places eminently suited for agriculture, seldom 

 yield wood for fuel or construction. Trees as a rule are only- 

 found fringing the deep river valleys, and in steep-edged gullies, 

 where they are protected from the sweep oi' the prairie firos, and 

 find a permanent supply of moisture. 



In the western portion of the Dominion, in Manitoba and the 

 Red River country, the Carboniferous formation is not found at 

 all, but the Cretaceous rocks already alluded to, overlap the 

 limestones of the older Silurian period. The true coal formation 

 can only be supposed to exist there below a great thickness of 

 Cretaceous rocks, and even if accessible the probability of coal 

 of any value being found in it is, from analogy with the regions 

 already mentioned, exceedingly small. 



Neither do the Cretaceous rocks of the eastern portion of the 

 plains yield, so far as known, any fuel of economic value in their 

 great stretch from the borders of Mexico to the northern part of 

 the British North-West. They consist almost entirely ©f clay 

 rocks and sandstones, with one interesting zone of limestone and 

 marl, which forms part of Hayden's group 3, or Niohrara Divi- 

 sion, and which appears to be recognizable in Manitoba at Pem- 

 .Mna mountain. 



