662 ALFRED W. G. WILSON 



the writer's attention to the fact that the bottoms of the channels 

 of the westerly and northwesterly flowing streams are almost 

 graded, although, on account of the steepness and shortness 

 of the descent from the plateau to the coastal plain, they 

 are an almost continuous series of impassable rapids. On the 

 other hand, in the case of the channels of many of the streams 

 flowing to the St. Lawrence we find a series of step-falls or 

 rapids with quiet reaches above and with steep canyon walls 

 beside the falls, so that these latter, though they have cut out 

 deep valleys, are yet in a less mature stage than those on the 

 other side of the divide. 



It should also be noted that the general direction along which 

 the streams would develop by normal erosive processes would be 

 determined, as in the case of the gorge of the Hamilton River, 

 by lines of structural weakness in the rocks, not necessarily by 

 lines of open fracture. 



A second theory would regard the majority of these valleys 

 as the incisions of superposed streams. The Paleozoic sediments 

 in the basin of Lake St. John are usually supposed to indicate a 

 transgression of the Paleozoic sea into this locality, and at least 

 suggest that at one time the whole adjacent region was buried 

 beneath the Paleozoic sediments. The small remnant of an 

 ancient belted coastal plain found between Montreal and Quebec, 

 and farther east in Anticosti and the Mingan Islands, show that 

 there, where the Paleozoic sediments were undisturbed by the 

 orogenic movements of late Paleozoic time, normal processes of 

 erosion produced normal topographic forms. It seems not 

 unnatural to suppose that consequent streams developed on the 

 coastal plain would, when they reached the hard rock beneath, 

 have still persisted in their initial consequent direction. In this 

 connection attention may be drawn to a gorge on the 

 Betsiamites River. Low writes : 



Next turning to the northeast, the river, for a distance of eight miles, 

 breaks in a straight line through the Labradorite hills, which form almost 

 vertical walls on either side, rising from two hundred to four hundred feet 

 above the water (20, p. 7). 



The description of the river course and the country on either 



