Numerical simulation on the dynamics of continental lithosphere extension and break-up

This study simulated continental lithosphere extension and break-up through performing 2D numerical modelling with the I2VIS code. Based on the simulation results, the process of continental lithosphere extension and break-up at different stages under different boundary conditions is quantitatively analysed, and its major controlling factors were determined. Through a comparative analysis of different simulation results, the following findings could be obtained: (a) During slow extension, increasing extension rate leads to increased thinning of the continental lithosphere, further increasing the corresponding thickness of sediments. Meanwhile, a centre of settlement appears on the terrestrial side of the initial basin, and sediment deposition occurred. This slow extension mode does not induce intense destruction of the lithosphere with low-angle fault, which does not control deposition in the basin. Therefore, low extension rate is possibly a dominant factor controlling the formation of a depression-type basin. (b) In the fast extension mode (at a rate of 10mm/a), when hydrated mantle is absent, the continental crust experiences noticeable destruction. According to the simulation results, several translithospheric faults are observed in the absence of hydrated mantle. This indicates that continental lithosphere destruction is closely related to extension rate and lithospheric rheology.