74

shipment of ore. The owners resumed work in 1935 and shipped an
additional 30 tons of high-grade gold ore. In the autumn of 1937 some
ore was shipped from the silver-lead-zine vein that lies 700 feet east of
the gold-bearing veins. Further shipments of the gold-bismuth ore were
made during 1938. The initial lot of 350 pounds of dry ore sent to the
sampling plant at Prince Rupert assayed: gold, 3-0 ounces a ton; silver,
1-2 ounces a ton.

The gold-bismuth deposits occur along sheared and altered zones
in massive, finely crystalline tuffs, with which some beds of argillite are
interstratified. Most of the sheared zones lie parallel to bedding planes
and appear to have formed as a result of relatively small movements
produced when these rocks were folded. These zones have a predominant
southeast strike and dip 20 to 40 degrees southwest in the lower, more
westerly occurrences. The upper and more easterly zones strike south
and dip 20 degrees east. Some of the sheared zones are steeply inclined
and connect a number of those with low dips. The productive zones are
largely confined to the crest of an anticlinal fold, the axial plane of which
is about vertical and which trends in a southwest direction. The fold
has a pitch of about 25 degrees to the southwest. A short distance above
the deposits the rocks are largely argillites with some interbedded
greywacke and conglomerate. These beds strike southwest and dip about
50 degrees southeast. Below the deposits the tuffs pass downwards into
a thick series of andesite flows. A silver-lead-zine vein occurs along a
fault fissure in these andesitic rocks about 700 feet northeast of the
gold-bismuth deposits. About 400 feet farther northeast the andesites
are in faulted contact with younger sediments. These sediments are slate,
quartzite, argillite, and conglomerate, and contain numerous narrow coal
seams near the base of the formation. No intrusive rocks were seen in the
immediate vicinity of the mineral deposits, but boulders of coarse
porphyritic granite were noted near the foot of the glacier at the head of
Glacier Gulch. The volcanic rocks at the foot of the glacier are intruded
by lamprophyre dykes up to 20 feet in width, and joint planes in these
dykes contain seams of calcite and molybdenite up to half an inch wide.

The bulk of the ore mined to date has been quarried from a relatively
small area, measuring possibly 150 feet in length and rising through a
height of 75 feet. The sheared and altered zones commonly exceed
100 feet in length and have an average width of from 1 to 2 feet. There
are five or six of these zones roughly parallel to one another in the
productive area. The ore shoots range from a few inches up to several
feet in width and from a few feet up to 50 fect in length. The ore occurs
in the most altered parts of the sheared zones, where the tuff is bleached
to a dull white colour. This type of rock grades along the sheared zones
into less altered, dull yellowish brown rock. A number of samples of the
less altered rock were assayed for gold with negative results. In some
eases the altered rock is replaced by considerable quartz. The limited
number of samples collected seems to indicate that the vein quartz carries
gold in economic amount only where tetradymite is present.

The high-grade ore (See Plate III) is a white, silicified tuff holding
the bismuth telluride, tetradymite. This mineral occurs as very thin
seams along the planes of shearing and as irregular replacements, and is