GEOLOGY OF THE WILDCAT COPPER DEPOSIT IN THE
ANTAMOK MINE OF BENGUET CONSOLIDATED, INC.
Florian V. Damasco
The Wildcat Copper Deposit in the
Antamok Mine is a massive sulfide
deposit occurring in Paleocene to Eocene
submarine coarse metaclastic-volcanic
sequence called the Wildcat
conglomerate. Ore formation is believed
to have occurred in mid-Miocene time.
The deposit is cut up and faulted by
younger gold-quartz veins. Intense
sericitization is the main alteration
guide. The main copper mineral is
chalcopyrite, comprising as much as 90%
of the total safides in the ore. The ore
texture is blebby to massive. A pyritic
halo occurs around the orebody. With a
cut-off of 1.0% Cu, mining rates by
underhand cut·and fill range from 8,000
to almost 15,000 MT per month. Ore
reserves of between 400,000 and 700,000
have been maintained through the years
since the discovery of this blind
deposit by Company geologists in 1968.
From the academic point of view, the
genesis of the deposit is thought to be
either syngenetic (volcanogenic) or as
an epigenetic hydrothermal deposit. Ore
must have formed after remobilization
due to nearby igneous intrusive
activities, then reconcentrated in the
highly permeable Wildcat conglomerate.
Another point of interest is whether or
not the top of the orebody is a post-ore
unconformity or a conformable contact
between the host rock and the overlying
Middle Keratophyre formation.
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