
GLACIAL PHENOMENA AND SUPERFICIAL DEPOSITS. 229 
without however falling much in general elevation below the tops of the 
bolder hills further east. We have in fact passed up over the margin of 
the third great prairie steppe. 
525. The whole of the Coteau belt is characterized by the absence of 
drainage valleys, and in consequence, its pools and lakes are very often 
charged with salts, of which those most abundantly represented are 
sodic and magnesic sulphates. The saline lakes very generally dry up 
completely toward the end of the summer, and present wide expanses 
of white efflorescent crystals, which contrast in colour with the crimson 
Salicornea, with which they are often fringed. The crystalline crust gen- 
erally rests on a thick stratum of soft black mud. 
526. The boulders and gravel of the Coteau were here observed to 
_be chiefly of Laurentian origin, with however a good deal of the usual 
white limestone, and a slight admixture of Quartzite drift. On the western 
margin, some rather large disused stream vallies were seen, holding chains 
of saline lakes; but their relation to the drift materials of the Coteau 
were not so clearly shown as in other localities further north, to be 
described. 
527. In passing westward, from the last exposures of the Tertiary 
rocks near Wood End, to the locality of their first appearance within the 
Coteau, a distance of about 70 miles; we rise about 600 feet, and attain an 
elevation of about 2,500 feet above the sea. The slope of the surface of 
the Lignite Tertiary then, assuring it to be uniform, is a little less than 
one hundred feet per mile; and on and against this gently inclined plane, 
the immense drift deposits of the Coteau hills are piled. 
528. The general structure of the Coteau on the forty-ninth parallel, 
is illustrated in figure 1, Plate XIII. It agrees well with the section given 
by Dr. Hector, of the borer of the Coteau, on the Elbow of the South 
Saskatchewan,* but it is interesting to observe that, in that locality, the 
underlying slope is composed of Cretaceous strata; showing that the 
Coteau is not connected with any particular formation, but forms a border 
round the north-eastern edge of a gentle elevation, in which both Creta- 
ceous and Tertiary rocks are involved, and which determines the water- 
shed. 
529. Passing westward for about seventy miles, it is found to preserve 
much the same appearance. The prairie of the Coteau foot, is rather 
undulating, and slightly raised above the general level, but the edge of 
* Exploration of British North America, p. 317, 
