AMERICAN GEOLOGY DECADE OF 1870-1879. 575 



of Lake Ontario, heaping- up at the same time in the lea of the Lau- 

 rentian ridge the great mass of bowlder clay which intervenes between 

 Lake Ontario and Georgian Bay. Lake Erie and Lake Michigan 

 were, he argued, cut out by similar currents. At times of obstruction 

 of currents which produced the southwest striations, while the val- 

 leys of the Ottawa, Mohawk, Lake Champlain, and the Connecticut 

 were arms of the sea, the currents would set along these arms, pro- 

 ducing the northwest and southeast striations. 



Local glaciation might prevail in high peaks, but the so-called 

 moraines were to his mind shingle beaches and bars and old coast lines 

 loaded with bowlders and ozars. The tiords on the coast, like the 

 deep lateral valleys of mountains, were evidences of the action of 

 waves and currents rather than those of ice. 



The subsidence noted above, which would result in converting the 

 plains of Canada, New York, and New England into seas and cause 

 the Arctic current to flow over the submerged area from northeast to 

 southwest, would produce a current which would move up a slope, 

 and the ice which it bore would, therefore, tend to ground and grind 

 the bottom as it passed into shallow water." 



In the first edition (1855) of Acadian Geology the occurrence of the 

 albertite deposits in the Lower Carboniferous rocks of New Brunswick 

 received considerable attention. In the discussions there given relat- 

 ing to their origin, he concludes that the material belongs to the purest 

 variety of bituminous coal, related to the pitch coals or jets. He 

 admitted, however, that it had some claim to be considered a distinct 

 mineral species intermediate between the coals and asphalts. At that 

 time he regarded the deposit as having originated through the deposi- 

 tion of organic matter in fresh water, the deposit having since been 

 very singularly distorted by mechanical pressure. 



In the second edition of the work (1868) he, however, modified his 

 expressed opinion, accepting the views of more recent explorers like 

 Hitchcock, Bailey, and Hind, who had described the deposit as a vein 



"To substantially these views Dawson held to the very last. In his Ice Age in 

 Canada (1893) he is found still combating vigorously the idea that all northern 

 Europe and America were covered by a mer de glace moving to the southward and 

 outward to the sea, and which moved not only stones and clay to immense distances, 

 but glaciated and striated the whole surface. The glacial theory of Agassiz and 

 others he described as having grown until, like the imaginary glaciers themselves, it 

 overspread the whole earth. He adopted rather what he called the moderate viev, 

 of Sir Roderick Murchison and Sir Charles Lyell, to the effect that Pleistocene subsi- 

 dence and refrigeration produced a state of our continents in which the lower levels, 

 and at certain periods even the tops of the higher hills, were submerged under water 

 tilled every season with heavy Held ice formed on the surface of the sea, as at present 

 in Smiths Sound, and also with abundant icebergs derived from glaciers descending 

 from unsubmerged mountain districts. The later Pliocene, so far as Canada was con- 

 cerned, he considered to be a period of continental elevation and probably ot tem- 

 perate climate. 



