THE LA UREA' TIA N PENEPLA IN 6 4 I 



rocks and falls more than three hundred feet in less than a mile. Below 

 Eaton Canon the river continues with a very rapid current for one hundred 

 and seventy-five miles to where it joins the Larch River, a very large branch 

 from the westward. (24, p. 210.) 



One of the best examples of this type of river valley is that 

 of the Hamilton River. Low's description is as follows: 



The Hamilton River like the Koksoak and all the other large rivers of 

 Labrador flows in a distinct valley cut down far below the general level of the 

 surrounding country. If Hamilton Inlet, which is only a portion of the 

 ancient valley now sunk below sea level, is included, the main valley extends 

 inland nearly four hundred miles, and its present bottom is from six hundred 

 to twelve hundred feet below the surface of the surrounding table-land. The 

 upper portion of the river flows nearly on a level with the lower portions of 

 the central tableland, and like the Kanapiskau spreads out into lakes or in 

 other places is broken into several channels by large islands, so that it is often 

 difficult to define or follow the principal channel. Near the Grand Falls the 

 river changes from a meandering stream that follows the lower levels of the 

 general surface, and contracting into one channel is precipitated into the 

 ancient deeply cut valley. In twelve miles this great river, with a volume 

 nearly equal to that of the Ottawa where it flows past the Capital, falls seven 

 hundred and sixty feet from where it issues from a narrow canon into the 

 wider valley. The first part of the descent is seven miles of rapids with a 

 total fall of two hundred feet. The river then contracts into a narrow 

 inclined, rocky trough down which it rushes with a tremendous velocity and 

 is spurted out in a solid mass over a steep precipice into a circular basin 

 three hundred feet below. The basin into which the river falls is about two 

 hundred yards wide and is nearly surrounded with vertical rocky cliffs, that 

 rise five hundred feet above the water .... From the basin the river rushes 

 out through a narrow canon cut vertically into the rock at right angles to the 

 falls. This canon on the level of the surrounding table-land is from one 

 hundred to three hundred feet wide, but at its bottom is often less than fifty 

 feet across. Down this narrow zigzag gorge the river rushes in a continuous 

 rapid with a fall of two hundred and sixty feet from the basin to where it 

 issues into the wider ancient valley eight miles away. ( 27, p. 212.) 



In the report on the southern portion of Portneuf, Quebec, 

 and Montmorency counties, Quebec, Low notes that 

 The rivers falling from the high interior plateau are much broken by rapids 

 and falls, and owing to their rapid descent are liable to great and sudden 

 variations in volume of discharge .... The valleys of the rivers and their 

 tributary stream.s are deep, with almost perpendicular walls, rendering cross 

 country travel very arduous, and in places impossible, while the dense forest 

 growth adds to the difficulties and hides many of the rock exposures. 

 (25. p. 7-) 



