330 On the Falls of Niagara. 



In the present very imperfect state of information respecting the 

 superficial deposits around the shores of our western lakes, it is out 

 of our power to do more than conjecture the geological era of the 

 supposed retreat of the waters which appear to have covered, at one 

 time, the vast plains surrounding them. Whether such an event were 

 caused by the general rush of waters from the north, or whether 

 it is to be viewed as having occurred subsequently, we have no 

 means of judging.* 



There is this important fact however, that none of the superior 

 secondary or tertiary formations of our Atlantic coast have been dis- 

 coyered in the region of these lakes, shewing clearly, that all that 

 portion of the continent emerged from beneath the ocean at a very 

 remote period. The drainage of the region has very probably been 

 repeatedly modified since that day, and during some one, or perhaps 

 several of these changes in its hydrography, Niagara acquired its 

 present remarkable shape. 



If any credit be due to the consideration here advanced, it must 

 be obviously improper for geologists to aim at computing the time 

 which the Niagara river has consumed in excavating its way to the 

 spot where it now pours off its waters, since to ascertain whQ.t portion 

 of the ravine below the falls may have resulted from other causes 

 than the cutting power of the stream, is clearly beyond our ability. 

 It is an observation of Professor Sedgwick, that the existing vallies 

 of any country are generally the result of the joint agency of many 

 causes and the remarkable valley of the Niagara river, notwithstand- 

 ing the simplicity of its present features, may exemplify this princi- 

 ple. 



The sides of the Niagara river below the falls present a narrow 

 belt of table land extending back a short distance firom the verge of 

 the precipice to the foot of a pretty high and steep bank composed 

 apparently of diluvium. 



There are in the class of those who assign to it a greater age, some who would 

 be inclined to consider it as also partly ti?jte-diluvian. To these my argument is 

 similar; to wit, that it is not credible that any powerful diluvial current should 

 traverse the surface of this region with the deep valley of the Niagara riyer pre-, 

 viously existing, without materially augmenting the length and magnitude of the 

 ravine. 



* Goat island is based upon a fine grained homogeneous clay in horizontal strat- 

 ification, and of a texture so exquisitely comminuted as to indicate the almost total 

 absence of any currents in the waters from which it was deposited. As one can 

 hardly attribute such a deposition to the impetuous current of the present river it 

 seems very naturally to point to a time when a tranquil lake covered the place of 

 the present rapid Niagara. 



