Calc-alkaline andesitic rocks are prominently exposed as a major product of subduction-related magmatism. The identification of Late Triassic andesites in Meiji Atoll, located in the southern South China Sea (SCS), provides new insights into the regional magmatic evolution and geodynamic setting of the southern SCS margin during the early Mesozoic era. Here, we present structured illumination microscopy (SIMS) U-Pb zircon ages, zircon Hf-O isotopic compositions, whole-rock and mineral geochemist