CHAPTEK III. 
THE ARCHAEAN AGE. 
The first, the oldest, rocks are at the surface over 
the greater part of Labrador, extending to the Great 
Lakes, and thence in a broad strip northwest be¬ 
tween the Hudson Bay and Mackenzie River, cover¬ 
ing a great V-shaped area. They also come to the 
surface on the south side of Lake Superior in Wis¬ 
consin and Minnesota, and in the greater part of the 
Hew England States; also on some of the highest 
mountain ridges of the Appalachians and at a few 
points in the Rockies. We find them, too, on the 
northeast coast of Scotland, in Bohemia, and in the 
highlands of Sweden. In all these locations they 
can be traced beneath other rock formations, and 
therefore they must be the oldest rock on the globe. 
It is necessary to give a little attention to the 
character of these rocks. In some places they lie 
almost horizontal, in others they are tilted or much 
contorted. Gorges and defiles are numerous in them, 
and outcroppings occur in many places, so chat they 
can be studied at many points (Fig. 7). This has 
been done in Canada by a number of geologists; 
prominent among them is Sir William Logan. 
Great beds of iron ore are found in these rocks, 
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