54 SURFACE GEOLOGY. 



feet thick, should have been able to sustain for centuries vast bodies of water, 

 ■while it was comminuting and depositing extensive beaches. I am fully satisfied, 

 that even though the geologist may, in his study, conceive of such icy or detrital 

 barriers, he could not maintain his opinion, were he to stand upon these beaches, 

 and turn his eyes towards the present ocean, and see what an immense mass of 

 materials must be required to fill up the country to the level of his eye, so as to 

 cut off all communication with the ocean. Certainly nothing like such piles have 

 been witnessed in any place on earth. It is true of some Alpine valleys, that 

 their lower ends have been choked with ice and detritus, so as to form ponds 

 above; but where do we find an example, in which the sides of such valleys, 

 many miles long, are formed by the same materials? 



Some, I know, consider no evidence of the presence of the ocean decisive, 

 unless it have left marine remains, and such we find in the United States 

 only among the more recent beaches and terraces, for example the clays around 

 lake Champlain, and along the St. Lawrence, at Montreal, &c, which are only a 

 few hundred feet above the sea. Why they do not occur among the more ancient 

 pleistocene strata, I mean the terraces and beaches, I know of no more probable 

 reason, than that animals and plants were not then living in the waters that made 

 these deposits. But that the beaches and terraces were formed by water, no one, 

 who will examine them, cau doubt. This being admitted, I am forced irresistibly 

 to the conclusion that this body of water must have been' oceanic, for the simple 

 reason that a sheet of water thick enough to reach such spots, must have spread 

 on all sides far enough to form a sea. 



It is possible that some may resort to the supposition, that though no high 

 rocky barriers have been worn down since the formation of the beaches and ter- 

 races, yet there may have been great changes of relative level since that time, so 

 that places, which are now lifted high above the general surface, may then have 

 occupied depressions where lakes existed. I can hardly believe that any one 

 practised in surface geology would adopt such an opinion, for he will see that 

 nowhere have terraces or beaches been disturbed by any such movements, but 

 retain exactly the contour and levels which they had when deposited. This 

 they could not have done if there had been any appreciable changes of relative 

 level : and to meet the case, such changes must have been very great. The hills, 

 too, that were rounded by the drift agency, present their stoss, or abraded sides, to 

 the north, just as they must have done when struck by such agency : and at the foot 

 of other hills, boulders are accumulated, just as they would be, if those hills stood 

 there during the drift period. In short, though there be evidence that the land as 

 a whole has either risen, or the water has retired from it, since the drift period, in 

 thirty years' examination I have never met with a single example of any change 

 of relative level in different parts of the surface by vertical movements since 

 that time; nor have I seen any such changes described, save that sort of see-saw 

 movement which Mr. Chambers found in Scandinavia, and which may have hap- 

 pened, also, in our own country, but which has never disturbed the relative levels 

 in the sense above supposed. 



14. It is hardly venturing beyond a legitimate conclusion, in view of the pre- 



