206 THE ICE AGE IN CANADA. 



Parallel and in his paper on the Superficial Deposits of 

 the Plains. To these reference may be made for details. 



The sections given in the figures represent some features 

 of these deposits, and are interesting as showing its 

 massive character in some places, and the fact of an 

 underlying deposit of water-sorted material. The general 

 structure, however, appears to be that stated in Chap. II., 

 namely, an under and upper boulder-deposit, separated 

 by beds of stratified silt, and sometimes holding vegetable 

 matter. 



I do not propose to extend these local details into the 

 vast regions lying in the Arctic basin, north of the 

 Laurentian water-shed and west of the basin of the great 

 lakes in Manitoba and the North-west and in British 

 Columbia. These regions have been described, the latter, 

 from personal knowledge, and both, with reference to all 

 the available authorities, by my son. Dr. G. M. Dawson, 

 F.RS., and I may refer to his two memoirs : " Notes on 

 the Geology of the Northern Part of the Dominion of 

 Canada," Eeports Geological Survey of Canada, 1887 ; 

 and " On the Later Physiographical Geology of the EocJ^y 

 Mountain Eegion in Canada," Transactions of Eoyal 

 Society of Canada, 1890. In these papers will also be 

 found copious references to all previous explorations and 

 sources of information. 



