94

western half of the ore ‘mass there are many barren ovoid rock masses 1
to 3 feet in length. In the heavily mineralized area bounding the ore-
body on the north, in the narrow western part (See Figure 17) the rock is
diorite only little altered and in it the magnetite seems mainly concentrated
in one irregular body, in places 10 feet broad, and which extends east and
west with a length of 100 feet. In the extension of this mineralized area
continuing northward, the diorite is, on the whole, more highly altered and
magnetite forms separate bodies some of which may be 40 feet long.

The Lake ore-body (See Figure 18) is about one-third mile east of the
Paxton and lies within the porphyrite area at the contact with limestone
that extends northward. The body outcrops on ground rising to the
north, the difference in elevation between the lowest and highest parts of

Scale of feet
KO, 30 A

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Geological Survey, Caraga.

Figure 18, Magnetite deposit, Lake mine, Texada island, B.C. Magnetite shown in ruling; porphy-
rite in crosses; and limestone by broken ruling. Contour interval, 20 feet.

the ore-body being about 65 feet. The boundaries of the ore mass are
fairly well defined. The outline of the body is somewhat irregular, but on
the whole is roughly quadrilateral with a maximum length and breadth of
170 feet. The exposed area measures 20,800 square feet. Several open-
cuts have been made along the south edge of the ore outcrop, but otherwise
no development work has been done. The general nature of the ore mass
is, as expressed by McConnell, as follows.

“The magnetite in the Lake mine ore-body is finer-grained than in
the other large masses and is freer from iron and copper sulphides. These
have developed in considerable quantities in the altered zone lying between
the main magnetite mass and the unaltered limestone (on the north) and
occur only in scattered grains and minute aggregates in the magnetite
itself. Non-metallic impurities, principally epidote and garnet, and less
frequently actinolite, calcite, and quartz, are fairly abundant. A rough
general sample taken from the faced magnetite cliff . . . . yielded:
iron 57-50 per cent; copper, trace; sulphur 0-046 per cent.”

Along the western part of the south boundary and for a considerable
distance away from it, the ore carries much finely disseminated silicates,
some calcite, and an occasional sulphide grain. Small spots and splotches
of coarsely crystalline magnetite and garnet with interstitial calcite are