and the Geology of the Surrounding Country. 109 



er or less distance ; they usually present a broad opening to 

 the north, and terminate at a point within the first mile, and 

 generally within a shorter distance. The streams now flow- 

 ing in these ravines, evidently had little or nothing to do 

 with their excavation, as the space is partially filled with 

 drift, a deposit from another source. These indentations are 

 doubtless in part the effects of the great denuding agency 

 which produced the escarpment, by undermining and remov- 

 ing the different materials. 



It has been supposed by some, and Dr. Daubeny has 

 adopted the opinion, that the terrace or escarpment at Lewis- 

 ton was produced by a fault ; either an uplifting of all the 

 strata on the south, or a downthrow of those on the north. 

 Not having Prof. Daubeny's paper before me, I cannot state 

 his arguments, but whatever they may be, they are certainly 

 unsupported by facts. The strata are all visible in either di- 

 rection, and there is no evidence of even the smallest disturb- 

 ance. 



The strata, as they are exposed in the terrace of Lewiston 

 and Q^ueenston, and in the banks of the river on either side, 

 are exhibited in the section on the next page. 



There is here not only no evidence of a fault causing the 

 difference in elevation, but direct proof to the contrary ; the 

 soft marl and shale, forming the base of the cliff in the river 

 banks, underlies the plateau from this place to Lake Ontario, 

 and is visible, almost continuously, for the whole distance. 

 On the other hand, there are the most unequivocal proofs of 

 denuding action, and that the whole basin of Ontario is due 

 to the excavating power. It will be seen that the character 

 of the strata is such as to offer great facilities for the operation 

 of such an agent, consisting of alternating hard and soft beds. 

 The action of water would undermine the harder, and leave 

 them to fall by their own weight, while the softer materials 

 were removed. The denudation of such extensive districts, 

 could only have taken place while the country was submer- 

 ged, and during the period of its elevation from beneath the 

 ocean. This principle has been recognized by Mr. Hayes, in 

 his description of the '' Geology and Topography of Western 



