Has the Hainan plume interacted with the oceanic lithosphere of the South China Sea？

Seismic, petrological, and geochemical studies confirm the existence of the Hainan plume in SE Asia, but whether the plume interacted with the oceanic lithosphere of the South China Sea (SCS) has been a subject of debate. To address this problem, we conducted a 3D gravity forward and inverse modeling to construct a 3D lithospheric density model of the SCS, incorporating all the geophysical and geological data available. Our findings indicate that the oceanic lithospheric mantle in the SCS has minor variation in both density and temperature, which contrasts with typical plume-ridge interaction signatures. Consequently, it is less likely the plume upwelled to the shallower part and interacted with the oceanic lithosphere. Instead, the affection of the Hainan plume is driven by deep mantle processes.