GOLD ORE SHOOT
DEVELOPMENT IN THE ANTAMOK
MINES, PHILIPPINES*
Henry E. Fernandez, Florian V. Damasco, and
Luisito A. Sangalang
ABSTRACT
Various possible ore shoot controls in
the Antamok mines have been recognized
by using actual veins as models. The
results indicate that are shoots are of
two distinct types: (1) subhorizontal
pitching ore shoots and (2) moderately
to steeply pitching ore shoots. The
former typifies a regionally controlled
ore shoot where the bottoms of the veins
are at almost the same elevation,
resulting from the interplay of orogenic
uplift, gravity, and pressure of ore
solutions; the latter type appears to
have been determined by structural
controls and to have developed locally.
The two ore shoot types occur together
and, if the veins are studied
individually, the subhorizontal aspect
can be easily overlooked.
Regionally controlled ore shoots, being
dependent to a large extent on the
episodic nature of vertical orogenic
movements, can be correlated to some
mappable manifestations of orogeny. This
idea was tested by mapping various
levels of stranded terrace gravels to
gain some insight into the vertical ex
tent of an ore shoot. Local controls are
manifested by accurate mapping of veins
on both plan and longitudinal sections
and by correlating them with existing
ore blocks of the mine.
Geological
Society of the Philippines
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