22

There are five small outcrops of magnetite and one of mixed magnetitey
and micaceous hematite, but taken altogether they were not considered of
sufficient importance to warrant detailed description and mapping. The
following notes are, however, given, since they are of scientific interest.

The deposits occur along the steep sides and in the gorge of Cascade
creek, where the creek makes two cascades. The valley slopes are clothed
with hemlock, balsam, and a few Douglas fir. Beale diorite is in intrusive
relations with andesite (lava, tuff, and breccia of the Vancouver series) and
limestone (Nitinat formation), and has altered the limestone to masses of
garnet and epidote, whereas the andesite is much fractured and metamor-
phosed to a type containing bunches and stringers of epidote and garnet,
and in places thinly interbanded garnet and tremolite. Higher up the
mountain, the rocks are chiefly diorite, and from here to the shore massive
limestone is predominant.

Small, lenticular bodies of magnetite occur in the contact altered
limestone as shown at the portals of the two tunnels, and elsewhere, but
the largest of these is about 25 feet long and 5 feet wide. Other irregular-
shaped masses of very impure rocky magnetite, impregnated with con-
siderable pyrite and chalcopyrite, occur in places; vein-like stringers
and layers of magnetite grains produce a strikingly banded appearance in
some parts of the altered andesite, a structure which is probably due to
the replacement of thinly-bedded andesitic tuff. In detail, these vein-like
stringers of magnetite are in the shape of flat lenses, similar to the occur-
rence on Copper island, except that they are much smaller, and carry con-
siderable pyrite along their margins. The andesite along these margins
is altered to a mixture of garnet and epidote.

Along the trail, and 150 feet southwest of the upper cascade is a small
lenticular mass of high-grade magnetite (4feet x 3 feet X 4 feet high) enclosed
by contact metamorphosed limestone, and showing no continuation. It is
of the variety lodestone and possesses strong polarity.

On the north side of the creek, where the latter takes a sharp bend to
the north, and 50 feet from the shore, is a showing of micaceous hematite
associated with magnetite, and thinly interbanded garnet and tremolite.
This showing is exposed only for a few feet up the bluff, and is about 2 feet
in width. Another small outcrop of the same kind was observed about
am feet farther east, along the line of the flume to the Wallace fisheries
plant.

On the Fern claim, therefore, both magnetite and hematite are devel-
oped, as replacements of limestone and andesite, but only in such small
amounts (as far as surface indications go) as to render the property of no
value as a source of iron ore.

O The group is recorded (1925) in the name of L. Manson, Nanaimo, B.C.

Bibliography

See page 158 for further details

21. Brewer, W.M., p. 21.
22. Whittier, W. H.