Lithospheric structure and evolution of the North China Craton: An integrated study of geophysical and xenolith data

Determination of the physical and chemical structures of the inaccessible continental lithosphere by comprehensive geophysical and geochemical studies can provide valuable information on its formation and evolution. Extensive studies from various disciplines have revealed complex lithospheric modification of the North China Craton (NCC), but less attention has been paid to an integrated study from different fields. Here we provide an integrated constraint on the lithospheric mantle structure of the NCC by comprehensive semiology, gravity and thermal studies with xenolith data involving depth (levels in the lithosphere), property (chemical and physical), and timing (formation and reworking ages). Our results suggest that the NCC has a relatively heterogeneous lithospheric mantle. Its margins and internal weak zones, especially in the eastern NCC, are generally underlain by the fertile, weakly metasomatized mantle with generally young formation ages. In contrast, its core tends to preserve the refractory, strongly metasomatized mantle with ages roughly coupled to the overlying Archean crust. Such a lithospheric structure shows the preferential modification of the lithospheric mantle in the eastern NCC and in the peripheral regions of the western NCC. The interior of the craton, especially most of the western NCC, remains stable and has been weakly modified.