

GENERAL OUTLINE OF THE GEOLOGY. 15 
27. The possible existence in the vicinity of the settlements of the 
Red River Valley, of beds referable to the period during which the 
deposits of coal in most parts of the world were produced, is a question of 
considerable interest, and has already attracted some attention. No 
exposures of Carboniferous rocks are known, and considering the low 
angles at which the Silurian and Devonian beds rest, and how close the 
area supposed to be occupied by the latter lies along the eastern edge of 
the Cretaceous, it is probable that the margin of the Carboniferous series is 
altogether concealed. Prof. Hind made a special search for the outcrop 
of these rocks along the base of the high-lands west of Manitoba Lake, 
which appears to be the most likely locality for their occurence; but 
unsuccessfully.* It would no doubt be possible, by boring in judiciously 
selected localities, west of the escarpment of the Cretaceous, in the Riding, 
Duck and Porcupine Hills, to penetrate that formation, and discover rocks 
of Carboniferous age; which may probably exist there at no very great 
depth. We know something of the Carboniferous formation of the 
interior continental region, however, from its development on the upper 
waters of the Mississippi, and it would appear that the search for any coal 
beds of economic value west of Iowa, is almost hopeless. The character 
of the rocks, as compared with those producing valuable coal beds further 
to the east, changes completely ; the thick shales and sandstones of the 
latter region, being represented by limestones accumulated in deep water. 
It is true that seams of coal are known as far west as Nebraska, but they 
do not exceed a few inches.in thickness, and seem to lie on the very 
margin of the coal-bearing basins of the east. This estimate of the value- 
lessness of the rocks of Carboniferous age which underlie the great plains, 
is confirmed by an examination of their representatives yet further 
west. Where again emerging to view along the slopes of the Rocky 
Mountains, they are not known either in the United States or in British 
America, to show any sign of reverting to their eastern coal-bearing 
character. This being the case, it would appear that the western prairie 
regions must depend for their supply of fossil fuel on the coals and lignites 
of the Cretaceous and Tertiary formations, there so extensively developed. 
28. Rocks of Permian or Triassic age are unknown in the interior 
region of British North America, with the probable exception of some 
beds of the Rocky Mountains, the equivalents of which south of the forty- 
*Prof. Hind figures a specimen of Producta, which Mr. Billings considered to be of Carboniferous 
type. It appears to have been derived from a boulder found near Fort Garry.—Rep. p. 187. 

