Mesozoic rock suites along western Philippines: Exposed proto-South China Sea fragments?. Issue 4 (1st December 2020)

• Record Type: Journal Article
• Authors: Yumul, Graciano P.; Dimalanta, Carla B.; Gabo-Ratio, Jillian Aira S.; Queaño, Karlo L.; Armada, Leo T.; Padrones, Jenielyn T.; Faustino-Eslava, Decibel V.; Payot, Betchaida D.; Marquez, Edanjarlo J.
• Is Part Of: Journal of Asian earth sciences. Issue 4(2020)
• Publication Date: 2020-12-01
• Subjects: Mesozoic -- Proto-South China Sea -- Ophiolites -- Philippines; Earth sciences -- Asia -- Periodicals; 555.05
• DOI: 10.1016/j.jaesx.2020.100031
• Languages: English
• ISSNs: 2590-0560

Abstract

Graphical abstract: Highlights: Mesozoic oceanic fragments and rock units are exposed along western Philippines. These Cretaceous ophiolites display transitional MORB-IAT affinity. Surrounding Oligo-Miocene ocean basins cannot be the source of the Mesozoic units. These Mesozoic complexes may represent parts of the proto-South China Sea plate. Abstract: An ancient oceanic crustal leading edge east of mainland Asia, the proto-South China Sea crust, must have existed during the Mesozoic based on tectonic reconstructions that accounted for the presence of subducted slabs in the lower mantle and the exposed oceanic lithospheric fragments strewn in the Philippine and Bornean regions. Along the western seaboard of the Philippine archipelago, numerous Mesozoic ophiolites and associated lithologies do not appear to be genetically associated with the younger Paleogene-Neogene ocean basins that currently surround the islands. New sedimentological, paleomagnetic, paleontological, and isotopic age data that we generated are presented here, in combination with our previous results and those of others, to reassess the geological make-up of the western Philippine island arc system. We believe that the oceanic lithospheric fragments, associated melanges, and sedimentary rocks in this region are exhumed slivers of the proto-South China Sea ocean plate.