1903-4. ] A Forty-MILE SECTION OF PLEISTOCENE DEPOSITS. 11 
A \FORTY-MILE SECTION OF PLEISTOCENE DEPOSITS 
NORTH OF LAKE ONTARIO. 
By ALFRED W. G. WILSON, MCGILL UNIVERSITY, MONTREAL. 
(Read 7th March, 1903.) 
THE north shore of Lake Ontario from Presqu isle, near the village of 
Brighton, Northumberland County, to a little west of Lorne Park, west 
of the City of Toronto, a distance slightly over one hundred miles in all, 
is formed for the most part by the pleistocene deposits of Central On- 
tario. Along the shore through most of this distance there are numerous 
sections exposed where the waves have cut back into these deposits. 
The best known and most important of these sections is that at Scar- 
boro, which was studied and described, first by Hinde, and later in more 
detail, by Coleman. In the present paper the writer presents a general 
description of the section exposed along the shore of the lake from 
Presqu’isle to the village of Newcastle, a distance of about forty miles, 
and a more detailed description of the last eight miles of the section, 
beginning a little west of Port Britain. 
The rock exposures which occur along this part of the shore of Lake 
Ontario are always of Trenton limestone. At Presqu’isle rock forms a 
low escarpment. There is almost no covering of drift, though occasional 
boulders, usually of archzzan rock, are found. In places there may be 
local deposits of sands, probably stratified, though there are no sections 
in which the internal structure can be obtained. West from Presqu’isle 
the next exposure of rock is found at Clarke’s Point, about two miles 
east of Lakeport pier. At this point the soil cover overlying the rock 
is also very limited. Between the point and Shoal bay to the east there 
