New zircon radiometric U-Pb ages and Lu-Hf isotopic data from the ultramafic-mafic sequences of Ranau and Telupid (Sabah, eastern Malaysia): Time to reconsider the geological evolution of Southeast Asia?

Abstract New zircon U-Pb geochronology from a peridotite suite near Ranau and the Telupid ophiolite in Sabah, eastern Malaysia, contradict previous studies, which assumed that Sabah mafic-ultramafic rocks are largely ophiolitic Jurassic–Cretaceous age. We show these formed during magmatic episode Miocene (9.2–10.5 Ma), is interpreted to reflect infiltration of melts melt-rock reaction subcontinental peridotites extension, concurrent seafloor spreading forming further south. Older zircons have Cretaceous, Devonian, Neoproterozoic ages. Zircon Lu-Hf isotopic data suggest their derivation depleted mantle. However, significant proportions crustal components been incorporated genesis, as evidenced by less-radiogenic Hf signature compared pristine mantle reservoir. The involvement component consistent with our continental setting for formation narrow backarc basin ophiolite. infer Sulu Sea, was expanding throughout much Miocene, may extended southwest into central Sabah. oceanic strand split, collapse, rollback arc due subduction Celebes Sea beneath Incorporation evolving potential source explain material evolution