Origin of Changbaishan volcano inferred from simulation of the Cenozoic Pacific plate subduction using geodynamic models with data assimilation

Abstract. The Changbaishan volcano has been considered a giant active intraplate volcano with hidden potentially disastrous eruptive risks, so its origin has attracted widespread attention from all over the world. However, this issue has not been adequately settled down due to its complexity. So far, three primary conceptual mechanisms have been proposed based on seismic tomography and geochemistry. All three mechanisms have been considered to be correlated with the subduction of the Pacific plate. Therefore, we use the best-fit thermochemical geodynamic model with data assimilation, which was determined by tracking the seismically inferred structure of the subducted Pacific slab beneath the Changbaishan volcanic province (CVP), to assess the their relative significance. The findings suggest that the super-hydrous melts in the mantle atop the Pacific slab, resulting from the slab dehydration in the mantle transition zone (MTZ), may primarily contribute to the volcanism of the Changbaishan volcano. Meanwhile, the other two mechanisms, the upward escape of the entrained oceanic asthenospheric material as well as the piling up and thickening of the subducted Pacific slab, may play secondary roles.