68 THE POST-PLIOCENE PERIOD. 



and whatever views may be entertained as to other boulders, it cannot 

 be denied that these have been bome by floating ice. Nor is it true, 

 as has been often affirmed, that the boulder clay is destitute of marine 

 fossils. At Isle Verte, Riviere du Loup, Murray Bay, and St Nicholas 

 on the St Lawrence, and also at Cape Elizabeth, near Portland, there 

 are tough stony clays of the nature of true " till," and in the lower 

 part of the drift, which contain numerous marine shells of the usual 

 Post-pliocene species. 



4. The Post-pliocene deposits of Canada, in their fossil remains 

 and general character, indicate a gradual elevation from a state of 

 depression, which on the evidence of fossils must have extended to at 

 least 500 feet, and on that of far-travelled boulders to several times 

 that amount ; while there is nothing but the boulder clay to represent 

 the previous subsidence, and nothing whatever to represent the sup- 

 posed previous ice-clad state of the land, except the scratches on the 

 rock surfaces, which must have been caused by the same agency which 

 deposited the boulder clay. 



5. The peat deposits, with fir-roots, found below the boulder clay 

 in Cape Breton, the remains of plants and land- snails in the marine 

 clays of the Ottawa, and the shells of the St Lawrence clays and 

 sands, show that the sea at the period in question had nearly the tem- 

 perature of the present Arctic currents of our coasts, and that the land 

 was not covered with ice, but supported a vegetation similar to that 

 of Labrador and the north shore of the St Lawrence at present. This 

 evidence refers not to the later period of the Mammoth and Mastodon, 

 when the re-elevation was perhaps nearly complete, but to the earlier 

 period contemporaneous with or immediately following the supposed 

 glacier period. In my former papers on the Post-pliocene of the St 

 Lawrence, I have shown that the change of climate involved is not 

 greater than that which may have been due to the subsidence of land, 

 and to the change of course of the Arctic current, actually proved by 

 the deposits themselves. 



These objections might be pursued to much greater length ; but 

 enough has been said to show that there are, in the case of north-eastern 

 America, strong reasons against the existence of any such period of 

 extreme glaciation as supposed by many geologists ; and that if we 

 can otherwise explain the rock striation and polishing, and the forma- 

 tion of fiords and lake basins, the strong points with these theorists, 

 we can dispense altogether with the portentous changes in physical 

 geography involved in their views, and which are not necessary to 

 explain any of the other phenomena. 



On these points, the Report of the Geological Survey of Canada 



