108 HalVs Remarks on Niagara Falls 



ward far into Canada, forming for many miles the northern 

 boundary of the lake. The southern slope of this terrace or 

 platform of limestone passes off beneath the water, forming 

 the bed of the lake. This terrace terminates abruptly on the 

 north, within a short distance of the lake, and we descend 

 into a low, level country, underlaid by marles and shales of 

 the saliferous formation, which extend for a distance of fifteen 

 or eighteen miles. Beyond this, there is an almost impercep- 

 tible ascent for eight miles, when it suddenly plunges down 

 about 250 feet, over the outcropping edges of various strata, 

 which here terminate abruptly, to the low table land, border- 

 ing Lake Ontario. From the base of this esc£irpment, the 

 country slopes almost imperceptibly to the level of the lake, 

 seven miles distant, and one hundred and twenty feet lower. 

 A great portion of the country for twenty miles north of the 

 first terrace, or that borderina: Lake Erie, is so level that a 

 rise of the Niagara river for thirty feet, would inundate an 

 extent of thirty miles on both sides. After leaving the level 

 country, the ascent, as before stated, is very gradual to the 

 north ; but when we arrive at the edge of the great terrace of 

 Lewiston and Glueenston, the elevation is thirtyeight feet 

 above the level of Lake Erie. The general outline of this 

 part of the country will be seen in the section from Erie to 

 Ontario. 



This great terrace or platform is known in New York as 

 the mountain ridge, and in Canada as Glueenston heights. It 

 extends to the westward of Niagara river, beyond the head of 

 Lake Ontario, and eastward beyond the Genesee river, where 

 it merges in the general level of the country ; partially from 

 the dip of the rocks in that direction, and partially from the 

 thinning of some of its members. The abrupt termination 

 of the various strata in the face of this cliff, prove conclusively 

 the extent of denuding action upon this portion of the coun- 

 try. The basin of Ontario, on the north of the terrace, has 

 evidently been excavated from the sedimentary strata, the 

 limit of denuding agency and that of the lake basin being 

 the line of this escarpment. The edge of this escarpment is 

 indented by numerous ravines or gorges, extending to a great- 



