Ancient Drainage of jYmih America, 6fC. 19 



The Queenstown ridge, which crosses the Hne of the ]\iagara 

 river about six miles south of lake Ontario, is a little to the west 

 of Queenstown, about 347 feet above the level of lake Ontario, 

 and consists of the lower limestone shale of British geologists; 

 having the carboniferous limestone superincumbent upon it, and 

 the common diluvium or superficial soil of the country resting 

 upon this last. In travelling up the gorge from Queenstown to 

 the cataract, where the bed of the Niagara flows, this geological 

 arrangement is constant, and at the cataract we find the shale 

 80 feet thick, and the carboniferous limestone lying upon it, 70 

 feet thick to the edge of the cataract. Higher up the stream, 

 other beds of the carboniferous limestone appear, containing 

 seams and patches of dark-coloured chert, which have furnished 

 the name of Black Rock to a village at the mouth of lake Erie. 

 This formation constitutes the floor of that lake, and may be 

 said to extend through the whole western country. 



At the general subsidence of the waters, before spoken of, it 

 is evident that when the level of Ontario fell below the summit 

 of the Queenstown ridge, the western waters would follow them, 

 seeking the great east line of drainage. Here then we find the 

 origin of the falls of Niagara, which would have their perpendicu- 

 lar height increased with the progressive subsidence of the waters 

 of Ontario. These waters would soon clear themselves a passage 

 through the superficial diluvium, and the manner in which the 

 whole gorge has been excavated from Queenstown, to the point 

 now occupied by the cataract, is attested by what we observe 

 going on in our own day. The loose friable shale is loosened and 

 washed out by the re-action of the fallen waters, and the super- 

 incumbent limestone losing its only support, yields to the weight 

 of the water, and falls into the gorge. The well known Table 

 Rock is an instance of this. The shale has been completely 

 washed out from beneath it, and great portions of it have fallen, 

 as other parts belonging to the edge of the cataract are con- 

 stantly doing. It is also particularly deserving of notice, that 

 the limestone beds immediately above the shale, are much thinner 

 at the opening of the gorge, and the rock less capable of resisting 

 attrition, than the superior beds which are so well compacted 

 with the chert, and which the cataract is only now approaching. 

 That the greatest portion of the rock which has hitherto fallen, 

 has been comminuted, and washed away by the stream, as the 



