232 THE JOURNAL OF GEOLOGY. 



The Canadian Ice Age. Notes on the Pleistocene Geology of 

 Canada, with Especial Reference to the Life of the Period 

 and its Climatal Conditions. By Sir J. William Dawson, 

 G.M.G., LL.D., F.R.S., F.G.S., etc. Montreal: William V. 

 Dawson, 1893. 301 pp., 8vo. 

 The work opens with a chapter of historical notices, embracing a 

 sketch of the tenets held by the author during the long period of his 

 studies on Pleistocene phenomena. Among these are the following : 

 I. The phenomena are not to be explained by any one cause, or by 

 any one all-embracing hypothesis. 2. The astronomical changes that 

 have been invoked are incapable of fully explaining the facts. 3. 

 There has not been, at any time, a polar ice cap. 4. The phenomena 

 indicate local mountain glaciers cooperating with floating ice in various 

 forms. 5. The cold climate was mainly the result of peculiar geograph- 

 ical conditions and of a different distribution of oceanic currents. 6. 

 The close of the period was not very remote. The author quotes freely 

 from his previous writings in elucidation of these views, and cites cer- 

 tain recent tendencies that seem to him to indicate a drift of opinion 

 towards the views he has held so long. 



In the second chapter he gives the succession of Pleistocene depos- 

 its in Canada, as he correlates them, as follows : 



Montreal and Lower Si. North Shore of Lake Belly River, Northwest 



Lawrence. Ontario. Territory. 



J. Wm. Dawson. J. G. Hinde. G. M. Dawson. 



I. L . I. 



Surface soil, post-glacial Surface soil, stratified sand Surface soil and prairie 

 alluvia, and peat. and gravel. alluvium. 



n. II. II. 



Surface boulders, Saxi- Boulders, sand, etc. Lam- Upper boulder clay, 

 cava sand and gravel, inated clay. Upper boulder 

 Boulders in and below sand, deposit. 



III. III. III. 



Upper Leda clay, marine Stratified sand and clay. Gray sand with iron-stone 

 shells and drift plants, with fresh-water shells and nodules. Brownish sandy 

 Lower Leda clay, marine plants. clay. Carbonaceous layers 



shells and drift plants. and peat. Gray sand iron- 



stone. 



IV. IV. IV. 



Lower boulder clay or till. Lower boulder clay or till. Lower boulder clay. 

 Many native and some trav- Native and traveled bould- Many traveled boulders, 

 eled boulders. A few mar- ers. 

 ine shells of arctic soecies. 



