E. Petitot on the Athabasca District. 33 



I have observed a saline spring near the mouth of the Clear- 

 water; a little below this point the Athabasca receives a saline 

 feeder, which rises in a natural salt-spring of considerable size ; 

 and below Lake Athabasca, on the left bank, is a second saline 

 feeder, rising in the Caribou Mountains, which contain vast 

 deposits of rock-salt, and a cavern remarkable for its crystalline 

 concretions. 



Still further, between Forts Simpson and Norman, two other 

 saline streams, unfit for drink, are fed by the mines of rock-salt 

 contained in Clarke's Rock, a mountain of volcanic aspect. 

 Lastly, there is a fifth saline river not far from the Arctic Ocean. 



About 56 ° 30' N. lat., the Athabasca meets Birch or Bark 

 Mountain, a continuation of the heights forming Portage la Loche 

 or Methy Portage (named after the loche or fresh-water cod-fish) 

 and leaves its former course in order to open a way across the 

 ravines of the mountain, thus making a right-angled elbow at the 

 east. This wonderful canon is called the Great Rapid. For some 

 twenty-five or twenty-eight leagues it impedes and much endan- 

 gers the navigation of the Athabasca. Besides the Great Rapid, 

 properly so called, the traveller must pass as best he may the 

 Brule, Noye, Pas-de-bout, Croche (or Sinuous), Stony, Cascade. 

 and ^fountain Rapids. In short, the whole make one continuous 

 rapid, twice as long as that of the Bear River, for the current 

 sometimes reaches a rate of twelve to fifteen miles an hour. 



There is nevertheless, strictly speaking, no cataract in the 

 Athabasca canon, only a very strong declivity, in the form of a 

 rapid flat sheet of water, obstructed by enormous boulders. At its 

 commencement the river finds itself checked by the vast natural 

 dam of Bark Mountain, the base of which is sandstone or madre- 

 poriferous limestone. The raging flood dashes against this 

 obstacle, in which it has striven to batter a breach for centuries, 

 washing away and carrying off the quartzose particles and expos- 

 ing the madreporic conglomerate, shelly limestone, or bituminous 

 sandstone forming the base of this vast deposit, and detaching and 

 isolating a multitude of globular masses of solid or hollow sandstone 

 contained in the quartzose sand, which now obstruct the bed of the 

 river and are the cause of its foaming rapids. These concretions 

 are found at every elevation of the cliffs, from the size of a coat- 

 button to that of a Dutch fishing-vessel ; they are of all degrees of 



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