30

The vein is 4,100 feet above sea-level, strikes north 80 degrees east,
and dips 50 to 60 degrees southward. It has been traced by open-cuts
for a distance of 800 feet. A crosscut adit 200 feet long has been driven
northward from a point 300 feet below the outcrop of the vein, but has
not gone far enough to encounter the vein. The vein varies from 1 to 8
feet in width and contains galena, sphalerite, pyrite, and a little chalco-
pyrite in a gangue of quartz, calcite, barite, and jasper. The value of the
vein matter depends on its lead and silver content. Clothier has estimated
the average lead content at 20 per cent and states that specimens con-
taining 77 per cent lead assay 16-8 ounces in silver.1 The vein is of good
length and width and should be explored farther by open-cuts in order to
give more information about its quality and to trace it beyond its present
known length. Shoots of ore may be discovered in this way that can
then be developed underground.

The chalcopyrite replacement deposit outcrops at an elevation of
2,900 feet. The country rocks at this deposit are approximately horizon-
tal voleanic fragmentals and possibly lava flows, and an interbed of
_ argillite. The mineralization consists of chalcopyrite disseminated
through the argillite and to a lesser extent through the immediately over-
lying volcanic rock. The upper part of the argillite bed contains more
copper than the lower part. The size and shape of the mineralized area
are not clearly outlined and the geological structure is not clearly under-
stood, but the accompanying plan (Figure 3) shows the writer’s interpre-
tation. The bed of argillite is evidently offset by two normal faults, with
in each case the downthrow on the east side. A narrow streak of clean
chalcopyrite lies in one of these faults, showing either that the faults are
pre-mineral in age or that faulting took place between an early and a
later period of mineralization.

A crosscut adit 150 feet below the outcrop of the mineral deposit
crosses a body of pyrite and chalcopyrite 5 feet wide at 212 feet from the
portal and enters another body of chalcopyrite near the face. The body
nearest the portal is vein-like, strikes at right angles to the direction of
the adit, and dips 65 degrees toward the face. This body has not been
found on the surface. The mineralization near the face ‘of the adit is in
argillite and in overlying volcanic rock, and is of the same type as that
in the argillite on the surface. It is assumed that this is the same bed
of argillite as outcrops on the surface, and that it was downthrown to its
present position by a fault (fault A, Figure 3; the amount of movement
along fault B is assumed and may be more or less than that shown in the
diagram). Further development can easily prove or disprove the assump-
tion. According to this idea the mineralization follows the argillite bed
and conforms rather closely to the strike and dip of the rock formation
which is gently dipping and striking at right angles to the adit. The
chalcopyrite in the fault fracture is worthy of notice as it may be wide
enough, in other parts of the fault, to make ore.

1Ann. Rept., Minister of Mines, B.C., 1925, p. 95.