430 Prof. Chapman on the Drift Deposits 
abundance, scattered, per se, over the surface of the gravels, or 
resting immediately on the underlying rocks where the clays and 
gravels are absent. This appears to have arisen in some cases 
from the subsequent removal or washing away of the looser 
materials in which the boulders were originally imbedded ; but 
the greater number of these were evidently thrown down where 
they now lie, by melting or stranded icebergs, after the deposition 
of the other Drift materials. The boulders, whether of gneissoid 
or other fossiliferous rock, belong always to northern localities 
in relation to the spots on which they now occur. Here 
and there the infiltration of water containing bicarbonate of lime 
has cemented some of these upper Drift deposits into conglome- 
rates of considerable solidity (Burlmgton Heights; vicinity of 
Niagara Falls; Georgetown, &c.). i 
5. Under the gravels and sands, or where the isolated boul- 
ders of this series are found, the rocks are always more or less 
marked by glacial action. The more common effects comprise a 
smoothed and polished surface, and a fine striation, the striz 
running in long straight lines in a general N.E. and 8S. W. direc- 
tion, although following to a certain extent, in hilly and broken 
districts, the natural windings of the rock-slopes on which they 
occur. These effects are seen in Western Canada, at various 
heights above the sea-level, up to an elevation of at least 1500 
feet. They are well shown on the top of the Collingwood es- 
carpment, at about 1000 feet above the level of Lake Huron; on 
the same line of escarpment near Niagara Falls ; on many of the 
rock-exposures on the north shore of Lake Huron ; and through- 
out the country at the junction of the Laurentian and Silurian 
formations, between the river Severn and the County of Fron- 
_tenac ; also in the vicinity of Belleville, Trenton*, &c. 
The isolated boulders scattered over the country frequently 
exhibit 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 rearrangement of the materials by the 
action of currents (e. g. Drift-bank seen in Great Western Rail- 
* See a paper, by the writer, ‘‘On the Geology of Belleville and its En- 
virons,”’ in the ‘ Canadian Journal,’ vol. v. (new series), pp. 41-48. 
+ The localities cited in this paper are those which have come more im~ 
mediately under the author’s observation. In most instances the lists 
given might be greatly added to. 
