EAMSAT DEIFT-PEEIOD OF CANADA. 213 



to add to the accoimt of the Later Tertiaries of Niagara given by Sir 

 Charles Lyell and Professor Hall. 



Above the falls a terrace of drift with 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 limestone 

 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 scarped 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 2 in fig. 5), with 

 scratched stones and smaU boulders; and the upper terrace (No. 1) is 

 formed of 15 feet of red clay, thinly stratified, also containing an- 

 gular boulders and scratched stones of Laurentian gneiss, and of 

 Niagara limestones and other Silurian rocks. The top of the upper 



Fig. 5. — Section of the Later Tertiary beds near Niagara Falls. 



1. Red clay, with striated boulders, 15 feet S g 'Ciyx ^. 



thick. ^s^ ,V^ I^i^er. 



2. Sandy loam with scratched stones and V ^ V """^N: 



small boulders, 85 feet. Vv.^"-^^'^^^ 



3. Sandy loam, 35 feet. ^' C ^C-;:>-^ 



4. Niagara Limestone. 



5. Niagara Shale. 6. Talus. 



escarpment of drift forms the highest part of the whole plateau. 

 Being 135 feet above the edge of the fall, its top is 60 feet above 

 Lake Erie, which is only 70 feet above that edge. The edge of the 

 great escarpment above Lewiston is said by Mr. Hall to be 70 feet 

 above the top of the faU ; and therefore the escarpment No. 1 of the 

 accompanying diagram (fig. 5) is also 65 feet, and No. 2, 50 feet 

 higher than the top of the escarpment above Lewiston, and 45 feet 

 above Lake Erie. If this drift once extended across the space now 

 occupied by the gorge, as shown by the dotted lines, Lake Erie may 

 originally have extended thus far, and after a time the river gra- 

 dually cut out a channel in the drift and formed both terraces ; or 

 else an original terraced channel existed, formed during the emergence 

 of the country, the terraces being formed by marine denudation*. 



The lower terrace has, in part at least, been excavated by the 

 river, which, before the formation of the gorge, here spread into a 



* It deserves to be stated, that half-way up the cutting, on the surface, I 

 found a Cyclas ; and another was found by Sir Wm. Logan, with whom I mea- 

 sured the section, on the same terrace, behind Clifton House. Some bits of plate 

 of the " willow-pattern," howerer, lay near my shell ; and that found by Sir Wm. 

 Logan was on ground that had been stirred with the spade ; and we came to the 

 conclusion that the evidence they afforded was of very doubtful value. 



