6l8 ALFRED W. G. WILSON 



Lake Ontario, Georgian Bay, Green Bay, and Lake Winnipeg lie 

 upon the inner lowland in front of the cuesta. Lake Superior 

 lies in a depression away from both lowland and cuesta. The 

 portion of the ancient coastal plain in the vicinity of the Great 



Fig. I. — Sketch map of the Laurentian Peneplain and the country adjacent — 

 west and southwest of Hudson Bay. 



Lakes presents in general aspect and in its present attitude the 

 normal features of such a plain, with numerous drainage modifi- 

 cations due largely to differential uplift and glacial ice action. 

 The portion of the plain which lies west of the oldland area is at 



