Mesozoic magmatic activity and tectonic evolution in the southern East China Sea Continental Shelf Basin: Thermo‐mechanical modelling

Based on the seismic profiles, drilling, tomographic images and other geological data, we use the I2VIS code to program the Mesozoic finite-difference numerical model in the southern part of the East China Sea Continental Shelf Basin (ECSCSB). We try to model the basin evolutionary process by setting up different boundaries to the 2-D models. After analysing the simulation results of low-speed and high-speed stretching models, we found that under the condition of preliminary tensile value, the magma could not be generated in both rapid and slow stretching cases. This means that the regional extension of the Mesozoic ECSCSB is not the only dominant factor for basin evolution. Based on the analysis of the regional geological features and the modelling results, we suggest that the low-velocity lithosphere mantle in the study area may be due to the melting of the mantle caused by the subduction and dehydration of the Izawa Nasaki Plate. The evolutionary process of the Mesozoic basins in the ECSCSB is closely related to regional extension and the magma upwelling caused by subduction and dehydration of the Izawa Nasaki Plate during the Mesozoic Era. The magma upwelling led to large-scale magmatic events. It is likely to act in the Minjiang Sag, which resulted in the further rise of the Minjiang Sag and the formation of the present slope zone.