340 Glacial Phenomena of Canada. 



agar a commenced during the deposition of that clay, or a little 

 he/ore the close of the drift-period* If, with accumulated data, 

 the rate of the past recession of the Falls be actually determinable, 

 we shall then be in a condition approximately to show the actual 

 number of years that rrtve elapsed since the close of the North 

 American drift. It may perhaps appear that the approximate 

 period of 35,000 years, given by Sir Charles Lyell for the erosion 

 of the gorge, is below the reality. 



Drift and other Late Tertiary deposits at Niagara. — I have 

 little to add to the account of the late Tertiaries of Niagara given 

 by Sir Charles Lyell and Professor Hall. 



Above the falls a terrace of drift wiih boulders forms the left or 

 Canadian bank of the river. Just before reaching the Horse-shoe 

 Fall, the terraced bank recedes ; and a plateau of Niagara lime- 

 stone lies between it and the edge of the gorge. A road, with a 

 deep cutting in the drift, ascends the slope on the left between 

 Table Rock and Clifton House, at right angles to the river. First 

 there is a gentle slope of 35 feet, then a rapid searped rise of 85 

 feet, and behind the railway a second low terrace. The first and 

 •second slopes, 120 feet high in all, consist of sandy loam (Nos. 3 

 and two in fig. 5), scratched stones and small boulders; and the 

 upper terrace (No. 1) is formed of 15 feet of red clay, thinly 

 stratified, also containing angular boulders and scratched stones 



Fig. 5. — Section of the Latter Tertiarg beds near Niagara Falls. 



o-*~ -^3crx — o-Tf-AX 

 , '?- o\ » onr~f - - 



- / r . ii > 



I 



1. Red clay, with striated boulders, 15 Hi >• V 

 feet thick. 



2. Sandy loam with scratched stones ^WvW^ 

 and small boulders, 85 feet. \Vt> 6*^ 



3. Sandy loam, 35 feet. 



4. Niagara limestone. 



5. Niagara Shale. 6. Talsus. 



* It is well known that the Niagara escarpment is of older date than 

 the drift. Lake Erie is 329 feet above Lake Ontario; and the older 

 boulder-drift lies indifferently on the lower plain and on the table-land. 

 No one has yet attempted to show at what period this old coast-cliff, 

 about 400 miles in length, was formed. The upper platform, on a grand 

 scale, bears the same physical relation to the rocks of Lake Ontario, that 

 Oolitic escarpment and table-land in England does to the Liaa and 

 plains of New Red Marl below. 



