The Influencing Factors Of The Destruction Of The North China Craton

The North China Craton has experienced dramatic lithosphere destruction in its Eastern Block since the Mesozoic,and the influencing factors and dynamic michanism of the destruction remain a contentious issue.Study of the influencing factors and michanism of the destruction of the North China Craton is essential to understanding the formation and evolution of the global Craton lithosphere.Combined with the geological background of the North China Craton,we discuss the influence factors of lithospheric thinning and destruction in the Eastern Block of the North China Craton by using twodimensional thermodynamic numerical simulation.The simulation results show that the destruction of the North China Craton is affected by the three major structural elements of the North China Craton,which are the weak mid-lithosphere discontinuity(MLD),the Trans-North China Craton(TNCO)and the subduction of the ancient Pacific plate.The simulation results show that the paleo-Pacific palte subduction triggers mantle convection underneath the craton plate and drives the destruction process,while the rheologically weak MLD layer decouples the craton lithosphere into upper and lower parts.Then the subduction-related mantle flow can remove the sub-MLD part of the cratonic lithosphere by driving it horizontally toward the subduction zone,where the sub-MLD lithosphere is dragged into the mantle by the subduction of the oceanic plate and the finial result is the lithosphere thinning and destruction.The Trans-North China Orogen constrains the mantle convection and the lithospheric destruction to the eastern block.Our model results thus show three major factors affecting the destruction of the North China Craton,and provide a new explanation for the dynamic process of the cratonic destruction.