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' floating ice/ appears to 

 furnish the explanation 

 which is most in accord- 

 ance with the known 

 facts. 



That the morainic 

 material forming the till- 

 beds had its primary- 

 source in upland glaciers 

 seems beyond doubt. 

 The enormous amount 

 of waste represented by 

 the beds in question, as 

 well as the great size of 

 some of the erratics, de- 

 mands a more powerful 

 agent of transport than 

 shore - ice ; while the 

 highly - glaciated condi- 

 tion of many of the 

 boulders might be caused 

 by subglacial movement 

 and wear in the earlier 

 part of their journey. 



Many of the included 

 stones in the till have 

 evidently been water- 

 worn prior to their trans- 

 portation, and in some 

 cases these stones show 

 glacial striae. This sug- 

 gests that the watershed 

 which produced the gla- 

 ciers was not completely 

 ice-bound in its drainage ; 

 but tributary streams 

 probably carried their 

 water worn material down 

 to the main valleys, 

 where the glaciers would 

 occur far below the limits, 

 of the permanent snow- 

 line. Rounded stones, 

 in this way, might be- 

 come part of the ground- 

 moraine, and having 

 been caught up into the 

 lower part of the ice- 

 sheet, would be carried 

 off when the glacier 

 broke away and floated 

 off" as an iceberg. Shore- 

 ice might also pick up 

 s2 



