Economic Geology
Tungsten Deposits

Tungsten has been noted in a number of localities close to the Hazelton
group-batholith contact but most of the deposits are small, only one being
worthy of mention.

Deer Horn Mines Limited (17)

This property, described under gold deposits, also includes a tungsten
deposit of considerable size. During exploration of the gold deposit, scheelite,
though not common, was noted in the core but the main deposit is separate
from the gold occurrence and lies 800 to 1,000 feet west of the most westerly
pit exposing the gold-bearing quartz vein. The scheelite occurrence extends
northwesterly for at least a claim’s length.

The part of the property on which the scheelite deposit occurs lies
astride the contact between the main mass of the Coast Intrusions on the
southwest, which there consist of granite, quartz diorite and diorite, and
metamorphosed tuff, greywacke, shale, slate, and flows of the Hazelton group.
The shale and slate contain andalusite, epidote, chlorite, and zoisite, and
silicification is widespread in the volcanic rocks. Minor amounts of skarn
are present, but none was noted near the scheelite occurrence. There, epidote,
chlorite, and quartz, and some andalusite in the shale and slate are
characteristic.

At the scheelite deposit the strike of the contact of the granitic rocks
turns sharply from northwest to north for a short distance forming an
embayment of the Hazelton group rocks. The general effect of contact
metamorphism of the sediments in this embayment is more marked than
elsewhere in the vicinity. The volcanic rocks particularly appear to have
been minutely fractured and cut by a stockwork of quartz stringers that
carry scheelite. The stringers vary in width from a fraction of an inch to 4
inches but are commonly 1 inch to 2 inches wide. About 500 feet east of the
main showing volcanic rocks are cut by numerous stringers of quartz con-
taining small amounts of scheelite, commonly along their borders. Two veins
up to 2 feet wide, which also cut the volcanic rocks at this point, contain
no scheelite. Assays of samples proved the average scheelite content of this
occurrence to be much lower than that of the main deposit. In addition to
the scheelite and quartz a few grains of pyrite and chalcopyrite were noted
in the country rock and quartz stringers. These outcrops are above timber-
line and at most points are covered by talus that contains sufficient scheelite

to give a spectacular appearance under ultraviolet light at night.
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