Magma plumbing system and origin of the intraplate volcanoes in Mainland China: an overview of constraints from geophysical imaging

Volcanic eruptions, despite causing large-scale disasters, also provide important natural resources and are an effective way to understand the Earth's internal structure and its evolution. Herein, a comprehensive review is presented on recent progress in geophysical imaging of the structure and origin of intraplate volcanoes in Mainland China. We primarily focus on the Changbaishan, Wudalianchi, Tengchong, Hainan and Ashikule volcanoes as they are currently active and hence pose potential hazards during future eruptions, particularly the Changbaishan volcano. The Changbaishan and Wudalianchi volcanoes are widely believed to be caused by the dehydration of the stagnant Pacific slab in the mantle transition zone along with wet upwelling in the big mantle wedge. There are a number of different views regarding the formation mechanism of the Tengchong volcano. Some studies suggest that a big mantle wedge structure is also present under eastern Tibet, and the Tengchong volcano has a deep origin, similar to volcanism in NE China. Others suggest that the Tengchong volcano is caused by a local and shallow process. Most tomographic studies suggest that the Hainan volcano is a hotspot, and its track has been located in SE China by combining seismological, geochemical and numerical modelling data. A gap exists between the subducted Indian Plate and the Tarim lithosphere beneath the Ashikule volcano, which provides a channel for asthenospheric upwelling to give rise to intraplate volcanism in the Ashikule basin. The interactions of lithospheres may produce shear heating of the subcontinental lithospheric mantle, which can generate localized melting. This process has been proposed as an explanation for the intraplate volcanism in Ashikule.