GEOLOGY AND REMOBILIZED ASPECTS OF THE MASSIVE SULFIDE DEPOSITS OF PORT BICOBIAN, ILAGAN, ISABELA AND OTHER SIMILAR PHILIPPINE DEPOSITS

Rolando A. de Guzman

 

 

 

 

INTRODUCTION



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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