COPPER SILVER VEINS OF TELKWA DISTRICT. B58

tribution, their geological associations and mineral composition,
the deposits fall naturally into three groups, namely: those which
lie close to the contact of the main Coast Range batholith; those
near the contact of the intrusion which forms the core of the
Telkwa Mountains; and those scattered over the district but al-
ways associated with one of the later Bulkley eruptives. Each
of these groups has its own peculiar association of minerals and
structure, but in several instances the same veins have come under
the influence of mineralizing solutions of both the batholithic
rocks and the Bulkley eruptives giving an ore of a very striking
and unusual type.

THE VEINS LOCATED AT THE CONTACT OF THE COAST RANGE
BATHOLITH.

These veins are of considerably less economic importance than
the others and are represented by two small groups of claims sit-
uated south of Clear Creek in the northwest corner of the area.
The veins are irregular in width and direction; in some places
forming a tangled network of veinlets an inch or less in width
and in others forming large lenticular bodies 15 feet wide. The
longest of these veins was traced for 1,500 feet.

The gangue consists almost entirely of milky quartz with
small inclusions of highly silicified country rock. A slight tend-
ency to banding can be detected. Small vugs, a few centimeters
in size, occur plentifully in the quartz, and contain small crystals
of quartz and of brilliant pyrite.

The ore of these veins consists of large masses of galena with
small segregations of chalcopyrite, often containing crystals of
quartz 5 to 6 centimeters in length. Under the metallographic
microscope, besides the galena and chalcopyrite, zinc blende,
minute quantities of argentite, tetrahedrite, covellite, and hem-
atite were seen. The galena forms about 90 per cent. of the ore,
and the chalcopyrite the larger part of the remainder. The chal-
copyrite occurs as small, irregularly shaped grains in the galena
with smooth, rounded contacts, which suggest simultaneous depo-
sition. The argentite is also found in the galena but in very