Destruction of the North China Craton in the Mesozoic

TLDR

Cratons, ancient continental blocks formed mainly before 1.8 Ga, are defined by a rigid lithospheric root that provides long‑term stability, but can be destroyed by oceanic subduction, mantle plume‑induced thermal erosion, and associated felsic magmatism and ductile deformation, as exemplified by the North China Craton. The NCC’s decratonization was caused by flat‑slab subduction beneath it, with subsequent rollback of the paleo‑Pacific plate in the late Mesozoic. During the Mesozoic, the NCC experienced widespread felsic magmatism, deformation, pull‑apart basins, and deep‑crust exhumation, accompanied by removal of its thick Archean lithospheric keel and replacement with a thin juvenile mantle, evidencing extensive decratonization.

Abstract

The North China Craton (NCC) was originally formed by the amalgamation of the eastern and western blocks along an orogenic belt at ∼1.9 Ga. After cratonization, the NCC was essentially stable until the Mesozoic, when intense felsic magmatism and related mineralization, deformation, pull-apart basins, and exhumation of the deep crust widely occurred, indicative of destruction or decratonization. Accompanying this destruction was significant removal of the cratonic keel and lithospheric transformation, whereby the thick (∼200 km) and refractory Archean lithosphere mantle was replaced by a thin (<80 km) juvenile one. The decratonization of the NCC was driven by flat slab subduction, followed by a rollback of the paleo-Pacific plate during the late Mesozoic. A global synthesis indicates that cratons are mainly destroyed by oceanic subduction, although mantle plumes might also trigger lithospheric thinning through thermal erosion. Widespread crust-derived felsic magmatism and large-scale ductile deformation can be regarded as petrological and structural indicators of craton destruction. ▪ A craton, a kind of ancient continental block on Earth, was formed mostly in the early Precambrian (>1.8 Ga). ▪ A craton is characterized by a rigid lithospheric root, which provides longevity and stability during its evolutionary history. ▪ Some cratons, such as the North China Craton, can be destroyed by losing their stability, manifested by magmatism, deformation, earthquake, etc.