Collision between the North and South China blocks: A crustal-detachment model for suturing in the region east of the Tanlu fault

Abstract

A crustal-detachment model, based on the interpretation of linear aeromagnetic anomalies, surface geological observations, and deep seismic profiles, is proposed for the continent-continent collision between the North and South China blocks east of the Tanlu fault. The model suggests that during the mid-Mesozoic collision between the two continental blocks, the upper crust of the South China block in the Subei-Yellow Sea region was detached from the lower crust and thrust over the North China block for >400 km, whereas the lower part of the lithosphere was subducted under the North China block along a subsurface suture running east from Nanjing. The sinistral offset of the Qinling suture by the Tanlu fault is only 110-120 km in the deep crust—much less than previously suggested.