32 B GEOLOGICAL SURVEY OF CANADA

rough trail that follows this stream for several miles and then turns off to
Camp Robertson, which is about eight miles from the shore. From this camp
two other trails branch off, one leading west to Yakoun lake, three miles
distant, the other to Camp Wilson, about nine miles northwest.

On the Robertson trail, after leaving the Honna valley at a distance of
about four miles, the hills rise steeply, and the trail crosses the eastern
flank over a mass of conglomerate, which is probably a part of the ridge
seen on the shore west of Honna camp. In several of the small streams
that cross the trail between this and Camp Robertson, grey sandstone and
shale, usually dipping at a low angle, are exposed, the angle of dip rarely
exceeding ten degrees,

On the trail from this camp to Yakoun lake, similar rocks are seen
on several streams which flow northward, and a ridge of amygdaloidal
trap crosses the trail a short distance before the lake is reached. Near
the point where the trail strikes the shore are outcrops of a coarse
yellowish grit which extends along the shore for several hundred yards.
It holds scattered pebbles of quartz, bluish grey felsite, etc., and while
bedding planes are somewhat obscure has an apparent dip of east < 8°.
These grits seem to represent the lowest beds of the coal formation at
this place and to rest against the igneous rocks that rise steeply from
the western shore of the lake. In character, they resemble the coarse
yellowish grey sandstones of the Nanaimo coal basin.

Going south along the east shore of the lake from the end of the
trail, these grey grits are exposed for a fourth of a mile. They here over-
lie, hard, bluish grey, igneous-looking rocks that are probably a spur from
the hill range to the south, where similar rocks are seen on Mount Etheline.
South of this there are small outcrops of black shale containing a little
shaly coal, with outcrops of a hard, fine-grained, green diabase, which are
part of the underlying series. Still farther south, and near the southeast
angle of the lake, there is a small basin of coaly shale in which occurs a
small deposit of impure anthracite. This was prospected some years ago
by a small shaft sunk to a depth of about six feet at a point 100 feet
from the lake shore. The rocks passed through were a mixture of crushed
black shale and irregular stringers of impure anthracite coal which does
not appear to be of economie value. Farther west, between the shore of the
lake and Rennell sound, along which a trail, through what is called the
Rennell Sound pass, was partially cleared some years ago, small patches of
fossiliferous Cretaceous shales occur, resting on the igneous rocks. Fossils
from these deposits show them to belong to the upper part of this for-
mation. They have been determined by Dr. J. F. Whiteaves, and are as
follows :—