BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Vol. 1, pp. 287-310 April 5, 1890 



ON GLACIAL PHENOMENA IN CANADA. 



BY ROBERT BELL, B. A. SC, M. D., LL. D., ASSISTANT DIRECTOR OF THE 



GEOLOGICAL SURVEY OF CANADA. 



{Read by title before the Society December 26, 1889.) 



CONTENTS. 



Pago. 



Introductory Note 287 



The Evidence concerning Kepetition of Cold Epochs 288 



Geographic Changes of the Pleistocene 288 



The Ante-Pleistocene Surface 289 



The Evidence of Glacial Action 291 



The Direction of Glacial Flow 294 



The Formation of Lake Basins 297 



Keiiction of Rock Structure on Glacial Erosion 299 



Lakes of Double Outlet 301 



Discordant Strife 301 



Lake Agassiz 302 



Upward Movement of Bowlders 304 



The Period of Glaciation 306 



The Cause of Glaciation 309 



The Causes of Changes in Level 309 



Introductory Note. — In the following paper, Canada means more than the 

 narrow strip along the eastern part of the northern border of the United 

 States, with which the name was once familiarly associated in the minds of 

 the citizens of the latter country. Leaving out Alaska, Canada now means 

 the northern half of this continent. 



The extent of the area in the northern hemisphere which has undergone 

 glaciation during the drift period has now been pretty well ascertained, and 

 the greater part of it proves to lie within the Dominion of Canada. Con- 

 sidering this fact and also the diversity in topography and climate presented 

 by a country which stretches from the temperate zone to the north pole, it 

 must be admitted that we Canadiaus have a splendid field for the study of 

 the ancient glacial phenomena. 



In 1863 the writer prepared the chapter on surface geology in the 

 " Geology of Canada ; " and ever since that time he has paid particular 

 attention to this subject. His opportunities for persoual observation in all 



XXXVTII— Bull. Geol. Soc. Am., Vol. 1, 1889. (287) 



