224 DRIFT DEPOSITS AND ANCIENT EXTENSION 
Huron, and throughout the country at the junction of the Lauren- 
tian and Silurian formations, between the river Severn and the County 
of Frontenac. Also in the vicinity of Belleville, Trenton,* &e. 
The isolated boulders scattered over the country, frequently ex- 
hibit in themselves a polished and striated surface ; and the small 
boulders and pebbles imbedded in the gravel deposits, often present 
the same effects. (e.g. The pebbles found in the terraces north of 
Toronto; also those in Drift gravel in the environs of Belleville, 
Marmora, Guelph, Niagara Falls,+ &c.) 
6. The gravel and sand beds of this series occur, in places, in 
oblique stratification, or exhibit what is technically termed “false 
bedding.” This occurs at or near the upper part of the series, and 
is evidently due to a re-arrangement of the materials by the action 
of currents. (e.g. Drift-bank seen in Great Western Railway cut- 
ting at Toronto, and extending westward several miles; beds at 
Orillia, on Lake Couchiching; also near Collingwood, &e. A re- 
markable example, alluded to more fully in the second part of this 
paper, Deduction 8, occurs near the village of Lewiston, on the 
south shore of Lake Ontario.) I think it will be rendered clear, by 
what follows, that the currents in question were not marine, but were 
produced in the lake waters, when these stood at higher levels. In 
places, moreover, secondary ridges, or ancient spits, have been formed 
by the same action out of these drift materials. (eg. Ridge at 
Weston, near Toronto, described by Sandford Fleming, C.E., in the 
present number of the Journal ; and a ridge in Nottawasaga Town- 
ship, described by the same engineer, Can. Jowr., 1st series, vol. i. 
Also the ridge at Craigleith, in Collingwood Township, mentioned 
by the writer, in this Jowrnal, vol. v. p. 305.) These secondary 
ridges, it should be observed, are altogether distinct from the ter- 
races of the lake shores and intervening districts. A careful search 
would, no doubt, reveal their presence in very many localities. 
7. We now come to a fact of great interest: the occurrence of 
shells of fresh-water mollusca in the sands and gravels of these Drift 
deposits, at various levels above the present surface of our lakes. 
These shells belong to existing species, inhabitants of the surround- 
* See a paper, by the writer, “On the Geology of Belleville and its Environs,” in the 
Canadian Journal, Vol. V. (New Series), pp. 41-48. 
+ The localities cited in this paper, are those which have come more immediately under 
the author’s observation. In most instances, the lists given might be greatly added to. 
