Cenozoic history. Initial sedimentation on oceanic crust occurred during early Tertiary emplacement of ophiolite along a strike-slip zone. A sequence of arc-derived sediments at least 26,000 ft was shed into the eastern side of the basin during late Paleogene to Quaternary convergence along western Luzon. By the middle Miocene, the Central Valley became an elongate basin fringed by shelf deposits. Nonmarine deposition began in the Pliocene. Late Miocene to Holocene movement along the Philippine fault zone caused uplift and folding. Exploration models for gasprone hydrocarbon generation in the central basin.--Modified journal abstract.