and the Geology of the Surrounding Country. 13 



't> 



the strata became consolidated, there might have been pro- 

 duced a rent in this direction, as in the diagram which repre- 

 sents a transverse section. 



This may have been the first cause of directing the water 

 in its present channel, which was afterwards widened by the 

 river. There seems some reason to suppose this may have 

 been the' case, from the general direction of the chasm, being 

 at right angles with the strike of the strata. If this be true, 

 however, the fissure must have been extremely narrow, and 

 still have left to the river the work of excavation, though 

 under very different circumstances. The reasoning in regard 

 to the existence of a depression previous to the excavation of 

 a deep channel, will still hold true, as well as that regarding 

 the fresh water deposits, and the terrace extending to the 

 whirlpool. The future recession of the cataract cannot be 

 affected in any manner by this fact, for if such a rent ever 

 existed, it seems not to have extended as far as the present 

 site of the falls, for all the testimony is to the effect that the 

 process of retrogression goes on by the action of the water 

 upon the shale, which undermines the limestone. If there 

 was a fissure in the course of the Niagara, it did not reach so 

 deep as the bed of the river, for it seems quite certain that 

 the thick bed of sandstone (No. 2, of section,) has never been 

 excavated very deeply below the present surface of the river. 

 If these views resfarding the elevation of the terrace are 

 found to hold true, it will aid in establishing the opinion be- 

 fore expressed, that the present channel of Niagara is of 

 recent date. I have long believed that the former outlet of 

 the great Lakes was by the western end of Lake Ontario, 

 though I have not been able to make investigations to the 

 extent desired in order to establish that opinion. 



The period when the disturbance of the strata took place, 

 is one of great importance, and may aid in determining the 

 comparative age of the Niagara channel, and the period of the 

 drift. That the former was subsequent, however, does not 

 admit of doubt. I am not aware how far the terrace contin- 

 ues to decline westward from the Niagara river, but it is quite 

 certain that the limestone rises before going as far west as the 



