SAND DUNES. 



287 



ridges, until we arrived at Pine Creek, a distance of eight 

 miles from the preceding camp. Here the sand-hills are 

 absolutely bare, and in fact drifting dunes. Sending the 

 main party in advance, Mr. Dickinson and I set out to 

 examine the valley of the Assinniboine where Pine Creek 

 disembogues. The sand dunes were seen reposing on the 

 prairie level about 170 feet above the river. In crossing 

 the country to regain the carts, our course lay across 

 a broad area of drifting sand beautifully ripple-marked, 

 with here and there numbers of the bleached bones of 

 buffalo protruding from the west side of the dunes, me- 

 morials probably of former scenes of slaughter in buffalo 

 pounds, similar to those which we witnessed some weeks 

 afterwards at the Sandy Hills on the South Branch of the 

 Saskatchewan. The progress of the dunes is very marked ; 

 old hillocks partially covered with herbage are gradually 

 drifted by the prevailing westerly wind to form new 

 ones. Sometimes the area of pure sand was a mile across, 

 but generally not more than half that distance. The 

 largest expanse we saw was near the mouth of Pine 

 Creek, it is called by the Indians " the Devil's Hills," and 

 a more dreary, parched-looking region could scarcely be 

 imagined. 



Opposite the Souris the subjoined section of the north 

 bank of the Assinniboine was measured : — 



1. 22 feet pale yellow sand. 



2. 1 foot dark blue clay. 



3. 12 feet ferruginous gravel and sand. 



4. 4 inches dark green hard gravelly clay. 



5. 15 feet soft unctuous blue clay to the water's edge. 



It is very probable that, of this section, the lowest 

 number represents the weathered shales which were 

 afterwards found exposed a few miles up the Little Souris 

 valley. 



