tchewan flows betwixt banks from one to two hundred feet in height,
consisting of clay or sand, and the beds of limestone are exposed in
very few places. The plains in the neighbourhood of Carlton abound in
small lakes, some of which are salt. The country which the Saskatchewan
waters for one hundred and ninety miles before it enters Lake Winipeg,
is of a different kind. It is still more flat than that about Carlton,
and is so little raised above the level of the river, that in the
spring-floods the whole is inundated, and in several places the river
sends off branches which reunite with it after a course of many miles.
In this quarter the soil is generally thin, and the limestone strata are
almost every where extensively exposed. To the southward of Cumberland
House, the Basquiau Hill has considerable elevation. I had not an
opportunity of visiting it; but in the flat limestone strata, near its
foot, there are salt springs, from which the Indians sometimes procure a
considerable quantity of salt by boiling; and there are several
sulphureous springs within the formation.

I observed no beds of conglomerate in it, and no sandstone associated
with it; but the extensive plains which lie betwixt Carlton House and
the Rocky Mountains are sandy, and beds of sandstone are said to be
visible in some of the ravines.

The line of contact of the limestone with the primitive rocks of Lake
Winipeg, is covered with water; but at the Dog's-Head, and near the
north end of Beaver Lake, they are exposed within less than a mile of
each other. To the southward of the Dog's-Head in Lake Winipeg, and in a
few other quarters, some schistose rocks, belonging to the transition
series, are interposed between the two formations.

Before quitting the formations of Lake Winipeg, I may remark, that the
height of that lake above the sea is perhaps equal to that of Lake
Superior, which is eight hundred feet.

LIMESTONE OF THE ELK AND SLAVE RIVERS.

The next formation I have to mention is one which appears to possess
most of the characters ascribed by German geologists to the zechstein.
It extends from the north side of the Methy carrying-place down the
Clearwater, Elk, and Slave Rivers, and along the south shore of Great
Slave Lake to the efflux of the Mackenzie. The line I have traced was
the route of the expedition, and is also very nearly that of the eastern
boundary of the limestone. Primitive rocks occur in Lake Mammawee,
Athabasca Lake, a