Geochemical and zircon 18O–Hf–U/Pb isotopic study of volcanic rocks from Lutao Island in the northern Luzon magmatic arc

AbstractLutao is an islet off the eastern coast of the main island of Taiwan and is composed of pyroclastic agglomerates, volcanic breccias, lava flows, and dykes. There have been no reports of SIMS zircon oxygen isotopic data from Lutao Island so far, which has significantly hampered further understanding of its magmatic processes, such as crystallization, evolution, and generation of magma. In this study, we use zircon U–Pb dating, Lu–Hf and O isotopic analysis to constrain the age, origin, and magmatic processes of the volcanic rocks from Lutao Island. Integration of our new U–Pb and Hf–O isotope data with available published data allows us to better assess the timing and magmatic processes of Lutao Island in the context of the northern Luzon arc system. This work is the first report of SIMS zircon oxygen isotopic data of volcanic rocks from Lutao island. This study shows that the volcanic rocks from Lutao Island were generated by mantle-derived magma associated with high-T° hydrothermal alteration by seawater-derived fluids.