Craton destruction links to the interaction between subduction and mid-lithospheric discontinuity: Implications for the eastern North China Craton

The continental craton is generally considered to be stable, due to its low-density and high viscosity; however, the thinning and destruction of cratonic lithosphere have been observed at various parts of the globe, for example, the eastern North China Craton (NCC). Although a large number of geological and geophysical data have been collected to study the NCC, the mechanisms and dynamic processes are still widely debated. In this study, using 2-D high-resolution therrno-mechanical models, we systematically explore the key constraints on the destruction of cratonic lithosphere. The model results indicate that the craton destruction processes can be strongly influenced by the presence of the so-called mid-lithosphere discontinuity (MLD), and its interaction with subduction. The properties of the MLD layer and the density contrast between the lithospheric mantle and asthenosphere play significant roles in the destruction processes. Specifically, the presence of a deep and low-viscosity MLD layer within the cratonic lithosphere tends to enhance instability of the craton, making it easier for lithosphere destruction. In addition, a relatively thick oceanic crust, high convergence rate, and large initial subduction angles favor the craton destruction. Finally, we compare the model results with the observations of NCC, which indicate that the interaction between the Paleo-Pacific subduction and the MLD layer in the cratonic lithosphere has played an important role in the observed large-scale lithospheric removal of the eastern North China Craton. (C) 2020 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.