sting _in situ_ in that immediate
neighbourhood.

M'Tavish Bay is forty miles long, and twenty wide, and its depth of
water, near the eastern shore, exceeds forty-five fathoms. Some shoals
of boulders skirt the coast near Point Leith. M'Vicar Bay is about
seventy miles long, and from eight to twelve wide; and at the "fishery,"
in a narrow part, not far from its bottom, its depth of water, two miles
from the shore, is twelve fathoms. Dease Bay is equal to M'Tavish Bay in
extent, and opens to the S.W. into the body of the lake. The high lands
at the N.E. end, or bottom of this bay, have an even outline, and appear
to attain an elevation of eight or nine hundred feet, at the distance of
six or seven miles from the shore. Near its east side lie the lofty
islands of Narrakazzae which rise seven hundred feet above the lake.
Dease River, the principal feeder of the lake, falls into the bottom of
Dease Bay. It is two hundred yards wide, and from one to three fathoms
deep near its mouth. A few miles up this river a formation of soft red
sandstone occurs, which will be noticed hereafter.

LIMESTONE.--GREAT BEAR LAKE.

[Sidenote: 228*] At the mouth of Dease river there are hills five or six
hundred feet high, composed principally, or entirely, of dolomite in
horizontal strata. Some of the beds consist of a thick-slaty,
fine-grained dolomite, containing dispersed scales of mica, which is
most abundant on the surfaces of the slates. [Sidenote: 228] Most of the
beds, however, consist of a thin-slaty, dull, purplish dolomite,
traversed by veins of calc-spar. The structure of this rock is compact,
approaching to fine granular; and some of the beds have what quarry-men
term "clay-facings," that is, they are encrusted with a thin film of
indurated clay.

Greenstone slate? occurs in horizontal beds on the north shore, eight or
nine miles to the westward of Dease River: and at Limestone Point,[22]
about twenty miles from the river, a small range of hills terminates on
the borders of the lake, in shelving, broken cliffs, about two hundred
feet high. These cliffs consist chiefly of nearly compact light-coloured
dolomite, interstratified with greenstone, and a brownish-red limestone,
such as occurs in the hills at the mouth of the Dease River. In contact
with the greenstone, there is a bed of talcose limestone, having a
curved, slaty structure; most of the beds of dolomite are hard, and pass
into chert.

ALUMINOUS SHALE.--GREAT BEAR