122 A POPULAR EXPOSITION OF THE 
Belle Isle, at the mouth of the Mingan River, near the Seven Islands, 
and at the Murray Bay River, and the Gouffre. From Cave Tour- 
mente, the Laurentian 
strata run inland, at a [ 
distance of from ten 
to thirty miles from 
the river but roughly 
parallel with its course, 
and cross the Ottawa 
near the Lac des Chats. 
From this point, the 
strata extend both 
southwards and to the 
northwest. The south- 
ern portion crosses the 
Saint Lawrence about 
the Thousand Isles, 
and occupies a large 
area in the State of 
New York between Lake Ontario and Lake Champlain, including 
the wild district of the Adirondack Mountains. The narrow belt of 
crystalline rock connecting this southern Laurentian area with the 
main or northern region of these strata, probably exerted at the 
close of the Drift period, as discussed on a succeeding page, a 
remarkable influence on the physical condition of the country to the 
west. The other portion of the Laurentian outcrop, west of the Lac 
des Chats, traverses the back townships of the counties of Frontenac, 
Addington, Hastings, Peterborough, Victoria, and Simcoe, and strikes 
Georgian Bay near the mouth of the River Severn. From thence, the 
Laurentian rocks form the eastern and north-eastern shores of the 
Bay up to a point nearly opposite the east end of the Manitoulin 
Islands, or some five or six miles west of the most western mouth of 
French River, where they are overlaid by Huronian deposits. They 
reappear upon the east and north shore of Lake Superior, and ex- 
tend far into the great North-West—reaching in all probability to 
the shores of the Arctic Ocean. The vast area thus occupied by the 
Laurentian rocks, includes many thousands of square miles; and that 
part of it which lies within the limits of Canada properly so-called, 
greatly exceeds in extent the other portions of the Province. 
6. Agriculturvl Capabilities :— As a general rule, liable only to par- 
Fig. 154. 
