THE METASEDIMENTARY PACKAGES OF THE SABANG THRUST ON THE ISLAND OF PALAWAN, PHILIPPINES

The island of Palawan is a southwestern Philippine island that delineates the boundary between the South China and Sulu Seas. It lies near the trace of a short-lived, S-SE dipping subduction zone that initiated sometime in the early Oligocene. Subduction was accompanied by the seafloor spreading and opening of the South China Sea, along with the extrusion of the North Palawan Continental Terrane (NPCT) from Indochina. Subduction at the Palawan trench ended abruptly in the middle Miocene when the relatively buoyant NPCT collided with and jammed the trench. This collision resulted in the uplift and modern day exposures of both the early Oligocene Central Palawan ophiolite of the former overriding slab, and the underlying accretionary, low-grade metasedimentary packages which were derived from the upper portion of the subducted slab and leading edge of the NPCT.

In this poster session, we present structural data from the metasedimentary packages underthrusting the central Palawan ophiolite and provide preliminary interpretations regarding their significance within the tectonic framework of the relatively recent geologic evolution of southeast Asia.