Compilation of ages, trace element and Nd-Hf-Sr-Pb isotope geochemistry of Cenozoic basalts in the South China Sea tectonic domain

In recent studies, we have confirmed that the OIBs and N-MORBs accreted in the Hengchun accretionary prism (Hengchun Peninsula, southern Taiwan) are debris of the oceanic crust and seamount in the subducted South China Sea. This enables us to evaluate the contributions from the recycled oceanic crust and the Hainan Plume to Cenozoic basalts in the South China Sea region via investigating a compilation of geochemical and isotopic data. From a macroscopic perspective, we identified a regional mantle heterogeneity boundary approximately in accordance with the Red River – Zhongnan Fault system, and a specious FOZO-like mantle component, which are resulted from the subduction, stagnation and recycling of (paleo-)Pacific oceanic slab. Additionally, we attributed the carbonated melts (with high U/Pb and low Th/U ratios) emerged at about 25 Ma to the influence of the Hainan Plume. These findings shed new light on the understanding of the tectonic-magmatic evolution in the South China Sea region.