DRIFT ON THE LAURENTIDES. 



247 



Grooves and scratches occur on the limestones of Lakes 

 Winnipeg and Manitobah, where the surface has been 

 preserved from atmospheric agencies, but whether they 

 are of recent origin or connected with the drift, is not 

 certain. 



DRIFT. 



The distribution of drift throughout the region lying 

 between Lake Superior and Winnipeg is limited to a few 

 detached areas. The most important of these east of the 

 Height of Land is at the Great Dog Portage, where it 

 occurs in the form of beaches and terraces, which will be 

 described further on. The terraced drift in the valley of 

 the Kaministiquia, below the Kakabeka Falls, is evidently 

 of lacustrine origin. The Height of Land is covered with 

 true boulder drift, having an elevation of about 1500 feet 

 above the present level of the ocean ; but on the Height 

 of Land at the sources of the Pigeon Eiver, boulder drift 

 occurs at a considerably higher level. 



Small areas of drift may be found at the different 

 portages, and on the islands in Mille Lacs, but in no 

 instance east of Bainy Eiver, were they seen of sufficient 

 extent as to warrant especial notice. In the valley of 

 Eainy Eiver buff-coloured unstratifiecl clay, containing 

 magnesian limestone boulders, and superimposed by strati- 

 fied clay, occupies both banks for some distance along the 

 river. On the Winnipeg, patches of drift begin at the 

 Islington Mission, and, though far apart from one another, 

 increase in area as the country sinks, until, at the Manitou 

 Eapids, drift clay forms the banks of the river and con- 

 tinues to its mouth. 



In the lower part of the Valley of Eecl Eiver un- 

 stratifiecl clay, with boulders from Laurentian rocks and 

 limestone, rises from the water's edge to within four 

 feet of the surface, after which its colour changes, it 



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