Defining the South Central
Cordillera (Luzon)
Transtensional Strip: implications to mineral occurrences
Dr. Mario
A. Aurelio and the Philex Mining Corp. Exploration Team
Extended
Abstract
A
transtensional strip more than 50 km long and about 25 km wide is
defined between La Trinidad and Ansagan, Tuba, Benguet on the
southern half of the Luzon Central Cordillera. Elongated along a
NNW-SSE axis, this tectonic strip is bounded by left-stepping
branches of the left-lateral Philippine Fault System in Luzon. It is
bounded to the west by the Pugo Fault and to the east by the Tebbo
Fault. At the regional scale, this transtensional zone is dominated
by NE- to E-trending faults with strong indications of normal fault
movements. Microtectonic analysis of fracture and mineral vein
systems indicates strong conformity with the regional structural
direction. Computed least stress axis s
3 directions are oriented N165 on the average,
sub-parallel to the strike of the bounding faults. The existence of
known mineral deposits (e.g. Antamok, Thanksgiving, Santo Tomas) and
prospects (e.g. Butan, Ansagan) within the tectonic strip implies an
intimate relationship between transtension and mineral occurrence. |