654 ALFRED W. G. WILSON 



peneplain. The region is now in an extremely youthful stage of 

 a new geographic cycle. It is bordered on the west and south 

 by a belted ancient coastal plain whose mature drainage adjust- 

 ments have been subsequently modified by glacial action, and in 

 part by differential uplift. On the southeast the normal develop- 

 ment of the ancient coastal plain has been in part retarded and 

 modified by orogenic movement and dynamic process. Traces 

 of the normal coastal plain development are, however, in evidence 

 in a number of localities between Montreal and Anticosti. 



The inner concave margin of the plain is marked by a depres- 

 sion occupied by the waters of Hudson Bay. To the south and 

 southwest of the southern part of the bay there are traces of an 

 ancient belted coastal plain with a convex south-facing cuesta 

 development. For the most part this ancient coastal plain is 

 buried beneath glacial debris and the sediments of the young 

 coastal plain, the latter being superposed upon the former. This 

 young coastal plain borders Hudson Bay on all sides, and the 

 consequent drainage from the interior has incised well-defined 

 valleys in the soft glacial and marine deposits, the interstream 

 areas being little dissected. This modern coastal plain is of 

 varying width up to a maximum of nearly one hundred and fifty 

 miles. 



The denuded peneplain surface, although destitute of mantle 

 rock i7i sine, is strewn with glacial debris often of considerable 

 amount. In the interior of Labrador this material is often very 

 coarse, consisting of huge blocks and bowlders, with, however, 

 considerable amounts of finer debris. In the parts to the south 

 of James Bay, particularly in the Moose River basin and as far 

 south as the height of land, the plain is almost completely buried 

 beneath unmodified and modified glacial drift. Glacial drift in 

 less amount, often fine-textured, at times coarse rock debris, 

 occurs over the whole of the western portion of the peneplain. 

 There are, however, areas of considerable extent where the 

 amount of drift is very limited. 



In the Labrador region there is a limited forest growth in the 

 hollows. Most of the interior is bare and barren. In Quebec 

 and in Ontario south of James Bay the region is densely forested. 



