Metallogeny of the North China Craton: Link with secular changes in the evolving Earth

Abstract

The North China Craton (NCC) has experienced a complex geological evolution since the early Precambrian, and carries important records of secular changes in tectonics and metallogeny. Here we synthesize the salient geological and tectonic features of the evolution and destruction of the NCC vis-à-vis major metallogenic events, and the formation of potential ore deposits. We identify a close relationship between the major geological events in the NCC and those reported elsewhere on the globe. We trace the records of a regular change in the pattern of metallogeny, mineral deposit character, spatial distribution and genetic mechanisms, which closely match the timing and styles of the major geological and tectonic events in this craton.The NCC went through five major tectonic cycles: (1) Neoarchean crustal growth and stabilization, (2) Paleoproterozoic rifting–subduction–accretion–collision with imprints of the Great Oxidation Event (GOE), (3) Late Paleoproterozoic–Neoproterozoic multi-stage rifting, (4) Paleozoic orogenesis at the margins of the craton, and (5) Mesozoic extensional tectonics associated with lithospheric thinning and decratonization. Coinciding with these major geological events are five major metallogenic systems identified as follows: (1) an Archean BIF system, (2) Paleoproterozoic Cu–Pb–Zn and Mg–B systems, (3) a Mesoproterozoic REE–Fe–Pb–Zn system, (4) a Paleozoic orogenic Cu–Mo system, and (5) Mesozoic intracontinental Au and Ag–Pb–Zn and Mo systems. The ore-deposit types in each of these metallogenic systems show distinct characteristics and tectonic affinities.From Early Precambrian through Late Precambrian to Paleozoic and Mesozoic, the NCC records a transition from primitive- to modern-style plate tectonics. Evidence for imbricated oceanic plate stratigraphy in a subduction–accretion setting, and collisional orogenesis along at least three major zones of ocean closure are documented. Major transitions in tectonic style and surface environmental changes recorded in other parts of the world are also reflected in the geological history and metallogenic events in the NCC. Large-scale gold deposits formed through intraplate tectonics during the Mesozoic provide important insights into mantle dynamics and crust–mantle interaction associated with lithospheric thinning and craton destruction. The NCC provides one of the best examples for documenting secular changes in the geological history and metallogenic epochs of an evolving Earth.