COPPER SILVER VEINS OF TELKWA DISTRICT.

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erable silicification, and some epidotization with the introduction
of considerable hematite, has taken place. No sulphides were
seen in the dikes or near them.

Paragenesis—The observed structural relations could all be
satisfied if the minerals had been deposited in this order:

Quartz,
Bornite,
Chalcocite.

Epidote,
Hematite,
Calcite.

Silver,
Argentite,

: Hornsilver,
Chalcocite,
Chalcopyrite,
Covellite,
Malachite,
Azurite.

There is no doubt that the quartz was the first mineral to be
deposited in this vein, and the copper sulphides are so closely re-
lated that they must have followed very soon after, if indeed
they were not deposited at the same time. Such a close and in-
tricate intergrowth of quartz and sulphides is not often seen.
The relative ages of the copper sulphides is not so certain, and
there are two possible explanations: one that bornite, and per-
haps chalcopyrite, were deposited by primary solutions, and were
afterwards replaced by the chalcocite; the other, that the three
sulphides were deposited as primary minerals at about the same
time. The first view, though quite possible, is supported by no
visible facts except that there is bornite present. It is, however,
supported by theory founded on numerous observations made in
other parts of the world, and is the explanation which would, for