154 ROYAL SOCIETY OF CANADA 
The best localities in and about Toronto where the Pleistocene de- 
posits may be studied to advantage occur at Scarborough Heights, 
Taylor’s brick yard, Price’s brick yard, Gaol Hill, the Winchester Street 
Bridge, York Hills, West Toronto, and along the ha shore and valleys 
of the Humber and Don Rivers. 
MONTREAL. 
The city of Montreal and its surroundings within a radius of about 
twenty miles affords probably the most intricate as well as interest- 
ing field for geological research. Inquiries in this department of field- 
work have revealed the existence of no less than seventeen distinct geo- 
logical formations, which crop out or are exposed to view within the 
limited area in question. Four of these belong to the Quaternary or 
newest system, one is doubtfully represented, but is most probably refer- 
able to the Devonian system, one to the Silurian, seven to the Ordovician 
(Lower Silurian and Cambro-Silurian of many authors), whilst the 
remainder appertain to the Laurentian or Archean complex, besides a 
number of volcanic intrusions in which much detailed study and research 
has already been done but is still necessary before their relations are 
thoroughly understood and mapped out. (Vide Table No. V., p. 173.) 
A geological map of Montreal and its environs would comprise four 
distinct types of areas marked by four distinct orographic features 
worthy of note, as follows : 
1. A more or less hilly and mountainous plateau of Archæan rocks 
to the north and north-west of Montreal. 
2. A broad, flat, more or less elevated Ordovician plain, in the 
midst of which there are seen :— 
3. A number of conspicuous, more or less elevate conical moun- 
tains or hills of volcanic origin. 
4, Alluvial flats, marine terraces, and raised beaches, forming the 
abandoned strands of former higher levels of the marine, estuarine and 
fresh-waters of the St. Lawrence valley composed for the most part of 
marine clays, sands and gravels, overlying “till” or glacial clays, the 
characteristic phenomena of the “ Great Ice Age,” and their redistri- 
buted materials. 
THE LAURENTIAN OR ARCHÆAN. 
To the north of Montreal in the Laurentide hills, this system is 
extensively developed and consists as in many other parts of Canada 
mainly of two divisions which can be recognized as an upper and a lower 

