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INTRODUCTION |
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The copper-pyrite deposits of Port
Bicobian, Ilagan, Isabela and other
similar Philippine deposits are
lentiform, massive sulfide orebodies
characterized by structures and textures
of deformational nature, locally reverse
mineral age relationships and, with
insignificant or absent “envelope" of
common wallrock alterations ascribed to
a causal plutonic association. The
country rocks are either serpentinite,
chlorite-sericite schists,
spilite-chertgreywackes or spilite-quartz
keratophyres.
These deposits are considered as
tectonically remobilized orebodies
regenerated from a particular level of
burial in the geosynclinal pile and
migrated in water deficient, sulfurated
and plastic state to their present
shallow sites of deposition concomitant
with an orogenic pulsation that
accompanied the spasmodic rise of
serpentinized ultrabasio rocks in
orogenic belts. Their progressive
emplacements, notably along thrust
faults, encompass a period between
Mid-Mesozoic and Late Cretaceous to
Early Paleocene.
The ultimate origin of these deposits,
to this date, is still a subject of
embroiling discussions.
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