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NEW YORK STATE MUSEUM 



has been uninfluenced by preexisting relief features. (Fig. i6) 

 Another feature of importance is the varying width of different 

 parts of the gorge, and the corresponding increase in velocity of 

 current in the narrower parts. The depth of the channel also varies 

 in different portions of the gorge, being in general greater in the 

 wider and less in the narrower parts. (Fig. i8) • . 



Fig. 16 Birdseye view of Niagara gorge showing the course of the river; the falls, the railroad 

 bridges, whirlpool, location of Fosters flats, escarpment at Queenston and flaring mouth of old St 

 Davids gorge. (After Gilbert) 



The first mile and three fourths of the gorge, or that portion 

 marking the retreat from the escarpment to the Devil's hole, extends 

 nearly due south, and is fairly uniform in width, comparatively nar- 

 row, and with a current of great velocity. The narrowness of this 

 stretch, when compared with the channel made by the present 

 cataract from the railroad bridges southward, seems to indicate a 

 smaller volume of water during its formation than that now passing 

 over the falls. An alternative hypothesis accounts for the narrow- 

 ness of this section of the gorge by assuming it to be a preglacial 

 drift-filled channel, made by an obsequent stream flowing north- 

 ward to the Ontario lowland, similar to that which made the old 

 St Davids channel, but reexcavated by the Niagara. It is highly 

 probable that there was at least a shallow channel which served as 



