40

consist in the main of chalcopyrite with a variable amount of pyrite. In
most cases there is very little gangue except country rock. The general
character of the veins of this type of deposit is well illustrated on the Van-
guard property where the chalcopyrite-bearing veins vary in width and are
not in general more than 10 feet wide. The wider parts of the veins con-
tain rock fragments and gangue minerals as well as chalcopyrite. In
some places several, narrow, closely spaced veins are present instead of
one large vein. Some of the narrow veins up to 2 feet wide appear to
consist entirely of chalcopyrite. Locally pyrite is plentiful. At the Wild-
cat similar veins occur and argillite inclusions in the intrusive country
rock are impregnated with pyrite and chalcopyrite.

Vein-like replacements are well exemplified by the deposits on the
Red Point group. These are rather irregular in shape. Some are veins
with quartz gangue and others are sulphide replacements of country rocks.

It seems probable that the intrusives of the Copper Belt are respon-
sible for the chalcopyrite mineralization. This type of mineralization is
confined to the Copper Belt and other types are lacking. If the chalco-
pyrite mineralization was genetically related to the body of Coast Range
intrusives lying to the west it would be expected that some mineralization
would be present in the area between the Copper Belt and the eastern
border of the batholith, but no mineral deposits are known to occur there.
Quartz-sulphide veins do occur, however, between the southern end of the
Copper Belt and the eastern margin of the batholithic area. On the other
hand, as already stated, on the Wildcat property small bodies of argil-
laceous rocks which are apparently inclusions in an intrusive rock are
mineralized with pyrite and chalcopyrite and thus seem to indicate that
the intrusive carried copper. Thus it appears that some of the intrusives
of the Copper Belt were potential sources of copper deposits. The localiza-
tion of the deposits within a definite band strongly suggests that their
source was at some depth below the exposed part of the band.

The augite porphyrite body of McGrath mountain contains dissemin-
ated pyrite, pyrrhotite, and chalcopyrite. Even where the rock appears to
be quite fresh the sulphides are present. It is not always possible to say
whether these sulphides were introduced or are original constituents. Evi-
dence obtained by the microscopic examination of the rock where altered
suggests that the sulphides were introduced into their present position.
The augite porphyrite appears to be closely related to the intrusives of
the Copper Belt and may be a potential mineralizer, but there is a lack
of any evidence that it should be regarded as being the source of the chal-
copyrite deposits. So far as is known these deposits do not show grada-
tions to any of the other types of mineral deposits of the area.

The commercial value of the deposits of the disseminated type is
unknown. It is possible that work might outline large bodies of ore. The
only reason for supposing otherwise is that no ore-body has yet been
found, although the amount of prospecting and development work is per-
haps sufficient to have located any existing ore-bodies.

The deposits of the vein type are of higher grade and are bounded by

definite walls. None is large enough to yield a large tonnage, but several
appear to have possibilities of becoming small producers.

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