A Cretaceous to Paleocene-Eocene South China sea basin origin for the Zambales Ophiolite Complex,Luzon, Philippines?

Abstract The Eocene Zambales Ophiolite Complex that exhibits transitional mid-ocean ridge basalt-island arc tholeiite (MORB-IAT) characteristics was formed in a subduction-related marginal basin. The different surrounding marginal basins of the Philippines, namely, the South China Sea, Sulu Sea Basin, Celebes Basin and the West Philippine Basin have all been modeled to be of probable provenance of this ophiolite complex. Certain information (e.g. age, rock geochemistry, paleomagnetic rotations) and limitations, nevertheless, are inconsistent with the ophiolite complex being generated in these regions. Recent geophysical evidence suggests that the southwest sub-basin of the South China Sea Basin is probably Cretaceous to Paleocene-Eocene in age. This makes it possible to speculate that the Zambales Ophiolite Complex could have come from this sub-basin. The present day rifting of the southern Izu-Mariana arc can be taken as a modern day analog of this type of ophiolite generation.