: 1056, 1062] In the neighbourhood of the lignite
there are some beds of rather indurated, but highly bituminous shale,
and the clayey banks contain clay-iron stones, in form of septaria. Mr.
Drummond likewise found beds of a beautiful bituminous coal, which
Professor Buckland, from its peculiar fracture, considers to be tertiary
pitch-coal. [Sidenote: 1058, 1059, 1060] The banks of the Saskatchewan,
near the same place, exhibit beds of a very compact stone, having a
brown colour, and inclosing many fragments of bituminous limestone and
some organic remains; likewise beds of a somewhat similar stone, but
full of drusy cavities, and more resembling a recent calcareous tufa. I
could not learn how far these beds were connected with the lignite
deposit.

Captain Franklin[31] saw beds of lignite and tertiary pitch-coal at
Garry's Island, off the mouth of the Mackenzie, and there is an
extensive deposit of it near the Babbage River, on the coast of the
Arctic Sea, opposite to the termination of the Richardson chain of the
Rocky Mountains.

MACKENZIE RIVER FROM SLAVE LAKE TO THE BASE OF THE ROCKY MOUNTAINS.

Having now described the strata in Bear Lake River, together with the
exposed beds of the lignite at its mouth, as far as opportunities of
observation enable me, and also added a slight account of similar
formations which occupy a like situation at the foot of the Rocky
Mountain range, were I to adapt the order of my notices strictly to the
route of the expedition, I should next describe the banks of the
Mackenzie from the junction of the Bear Lake River downwards to the
Arctic Sea. It seems, however, more advisable to commence at the origin
of the Mackenzie, in Great Slave Lake, and give as connected a view as I
can of the principal geological features of that great river.

The west end of Slave Lake is bounded by horizontal strata of a
limestone, whose characters shall be afterwards given in detail; and I
have merely to remark, at present, that it forms flat shores, which are
skirted by shoals of boulders of limestone, and of primitive rocks. Much
drift timber is accumulated in the small bays at this end of the lake,
which, in process of time, is converted into a substance like peat. A
chain of islands extends obliquely across the lake at the origin of the
river, or where the current is first felt; and the depth of the water
there is less than six feet. Below this, there is a dilatation termed
the _first little lak