126 



HalVs Remarks on Niagara Falls 



tion of this fresh water deposit. It is a cross section of the 

 river at the falls. 



a. The terrace with shells on the eastern side. 



h. Goat Island, c. The terrace on the Canada side. 



d. The ancient drift, L. Limestone. S. Shale. 



From its present position, it seems to have been a continu- 

 ous deposit, the greater part of which has been removed. 

 The mode of its formation can be well illustrated by referring 

 to Fig. 1, which is intended to represent what is now going 

 on above the rapids, in the broad expansion of the river. 

 a. a. represents the fluviatile deposit made by materials 

 brought down by the current, and doubtless mingled with a 

 large accumulation of shells of Unio, Melania, Anculotus, &c. 

 as these shells are abundant above the falls, and large num- 

 bers of the shells of Uniones are constantly brought down the 

 rapids during the summer season. 



The single terrace containing shells is not the only one, for 

 on the eastern side, at lower elevations, there are in succession 

 two others, which seem to be remains of the deposit in the 

 river bed, as it successively excavated its barrier to the north, 

 and receded towards its present position. For the greater 

 part of the distance from the falls to Black Rock, on the east- 

 ern side there is a terrace or bank a few feet higher than the 

 river, which may have originally limited its waters when it 

 stood at the level indicated b}'" the fresh water deposit of Goat 

 Island. Near Black Rock, and bordering the valley of the 

 Tonawanda, there is a terrace some twenty feet higher, 

 which appears to have been the boundary of the river or lake 

 at a still earlier period ; but with these we have, at present, 

 nothing to do. The existence of the fluviatile deposit of 

 Goat Island, and at the same level on the eastern side of the 



