258 W. UPHAM — GLACIAL LAKES IN CANADA. 



lake and its chain of waters, Nelson river receives supplies from the very 

 banks of the Missinippi or Churchill river. Indeed, the Beaver lake chain, 

 which lay in our route, originates within a hundred yards of the latter 

 stream." Frog portage, at this locality, *' is three hundred and eighty paces 

 long. The path leads through a low swampy wood, and over a flat tract of 

 gneiss rising only a few feet above the waters on each side." The further 

 descriptions of their journey up the Churchill river, which " resembles a 

 chain of lakes with many arms, more than a river," and by Isle a la Crosse 

 lake. Deep river. Clear and Buffalo lakes, and Methy river and lake to 

 Methy portage, indicate that this was at one time the avenue of outflow from 

 a glacial lake in the Mackenzie basin. ^ 



Ontario. — The province of Ontario, extending from the mouth of the 

 Ottawa westward to Lake of the Woods and from the great Laurentian lakes 

 northward to Albany river and James's bay, presents a most admirable field 

 for the exploration of glacial lake shores, deltas, and channels across water- 

 sheds. The recession of the ice-sheet was in general from the southwest and 

 south toward the northeast and north. As soon as its border was withdrawn 

 across the various parts of the water-shed south of the Laurentian lakes, each 

 considerable stream valley and erabayment between the height of land and 

 the ice-front held a glacial lake. Doubtless hundreds of channels may be 

 traced where these lakes outflowed. But the continuing glacial retreat 

 merged these minor lakes into a few of large size, overflowing at the lowest 

 passes. Portions of the Canadian shores of these glacial representatives of 

 the present Laurentian lakes are recorded by eroded clifls, beach ridges, 

 deltas, and lacustrine sediments ; but along other portions of their boundary, 

 where they were held in by the receding ice-barrier on the northeast and 

 north, the land shows no shore erosion nor beach deposits. 



From the western part of the basin of Lake Superior a glacial lake outflowed 

 to the Mississippi at the lowest point of the present water-shed between the 

 Bois Brule and Saint Croix rivers in northwestern Wisconsin. The bed of 

 the old outlet is 1,070 feet above the sea, or 468 feet above Lake Superior; 

 and it is bordered by bluff's about 75 feet high, showing that when the course 

 of outflow began here the West Superior glacial lake was approximately 

 550 feet above the present lake level. Silts referable to this glacial lake are 

 found near Superior and Duluth, and its delta deposits and shore lines are 

 traceable here and there along the northwestern shore of Lake Superior in 

 Minnesota, but it may well be doubted whether they extend into Canadian 

 territory. Before the ice-sheet had retreated so far as to uncover the region 

 about Port Arthur, its departure from Wisconsin and Michigan had prob- 

 ably permitted Lake Superior to become confluent with Lake Michigan over 



• Narrative of a Journey to the shores of the Polar Sea, in th^ years 1819, '20, '21 and '22, by John 

 Franklin, Captain R. N., F. R. S. ; including an appendix of Geognostical Observations by John 

 Richardson, M. D,, Surgeon to the Expedition. Also, Sir John Richardson's Arctic Expedition in 

 Search of Sir John Franklin. 



