Extent and Mechanisms of the North China Craton Lithospheric Destruction Revealed by Multi-Geophysical Inversions

Abstract

The North China Craton (NCC) has undergone significant destruction, yet the spatial extent and underlying mechanisms of the destruction remain subjects of debate. In this study, we conduct a joint inversion by integrating multiple geophysical data sets to establish an unprecedented large-scale compositional structure of the NCC lithospheric mantle. By incorporating lithospheric thickness constrained by thermal state, we provide a comprehensive assessment of the spatial extent and intensity of NCC destruction. Our results reveal significant variations in lithospheric thickness and mantle composition across the NCC and delineate a boundary marking the extent of its destruction. West of this boundary, including the core of the Ordos block, the lithosphere exhibits refractory characteristics and a thick lithospheric root, maintaining craton stability. In contrast, east of the boundary, including the Eastern NCC (ENCC), most of the Trans-North China Orogen (TNCO), and the northeastern part of the Western NCC (WNCC), the lithosphere shows signs of extensive modification. The ENCC features a refertilized lithospheric mantle and thin lithosphere, reflecting extensive reworking likely driven by large-scale lithospheric delamination during the Mesozoic. The TNCO and northeastern WNCC display localized mantle refertilization and high-degree partial melting in the asthenosphere, suggesting ongoing thermal erosions, likely driven by the influence of the Pacific slab's leading edge or its rollback. We propose that Cenozoic thermal erosion has extended the destruction of the NCC farther west than previously anticipated. This study identifies regions of significant lithospheric thinning and mantle compositional modification, improving our understanding of the NCC destruction and its evolving mechanisms.