Geodynamics of decratonization and related magmatism and mineralization in the North China Craton

Abstract

The North China Craton (NCC) experienced strong destruction (i.e., decratonization) during the Mesozoic, which triggered intensive magmatism, tectonism and thermal events and formed large-scale gold and other metal deposits in the eastern part of the craton. However, how the decratonization controls the formation and distribution of large-scale of gold and other metal deposits is not very clear. Based on a large number of published data and new results, this paper systematically summarizes all the data for the rock assemblages, chronology, geochemistry and petrogenesis of Mesozoic magmatic rocks, as well as for the mineralizing ages of gold and other metal deposits and the evolution of the Mesozoic basins in the eastern NCC. The results are used to restore the extensional rates of Mesozoic to Cenozoic basins and the strike-slip distance of the Tanlu Fault, to ascertain the location of the Paleo-Pacific plate subduction zones during the Mesozoic to Cenozoic, and to reconstruct the temporal and spatial distribution of Mesozoic gold and other metal deposits and magmatic rocks in the eastern NCC. It is obtained that the magmatism and mineralization in the eastern NCC westward migrate from east to west during the Early to Middle Jurassic, but they eastward migrate from west to east during the Early Cretaceous. The metallogenesis of these deposits is genetically related to magmatism, and the magmas provided some ore-forming materials and fluids for the generation of metal deposits. The geodynamic mechanism of decratonization and related magmatism and mineralization is proposed, i.e., the westward low-angle subduction of the Paleo-Pacific slab beneath the NCC formed continental magmatic arc with plenty of porphyry Cu-Mo-Au deposits in the Jurassic, similar to the Andean continental arc in South America. The mantle wedge was metasomatized by the fluids/melts derived from the subducting slab, laying a material foundation for hydrothermal mineralization in the Early Cretaceous. While the rollback of the subducting slab with gradually increasing subduction angle and the retreat of the subduction zones during the Early Cretaceous induced strong destruction of the craton and the formation of extensive magmatic rocks and large-scale gold and other metal deposits.

Discovery of Yaozhuang Stock and Deep Ore Prospecting Implication for the Western Mangling Orefield in North Qinling Terrane, Central China

“…Geophysical data show that there was a WNW-directed uplift in the southern margin of the North China Craton (Xu et al, , 2009Zhou 2006), which is consistent Dong et al, 2011a;Ke et al, 2012b;Liu et al, 2014;Zhao et al, 2021). Some workers suggested a flat-slab subduction model that the Paleo-Pacific subduction could extend up to 1,300 km inland and cause large-scale magmatism in the Late Mesozoic (Li and Li., 2007;Gao and Zhao., 2017).…”

“…The magmatism in the North Qinling terrane is still debated. Some workers suggested that magmatism occurred after the collision of the North China Plate and the Yangtze Plate (Zhu et al, 2009(Zhu et al, , 2010Dong et al, 2013), while others inferred that it was caused by the far-field tectonic transition effect of the Paleo-Pacific subduction beneath the Eurasia plate (Wang et al, 2015;Gao and Zhao., 2017;Yang et al, 2021). The Qinling orogen may have undergone continent-continent collision in the Middle-Late Triassic (242-221 Ma), followed by an intraplate orogenic stage (Bao et al, 2015;Li et al, 2015;Chen et al, 2019).…”

“…FIGURE 7 | Zircon ε Hf (t)-t diagram of Yaozhuang stock (A) and t DM2 statistical histogram (B) (data afterDong et al, 2011a;Ke et al, 2012b;Liu et al, 2014;Zhao et al, 2021).…”

Petrogenesis and geodynamic setting of the Late Jurassic Queshan adakitic granite, Jiaodong Peninsula, southeastern North China Craton: Zircon U–Pb geochronological, geochemical, and Lu–Hf isotopic evidence

“…The thickening of the lower crust caused by continental collision occurred before these events, but the further compression and thickening of the lower crust caused by the low-angle subduction of the Izanagi Plate beneath northeastern China is the main geodynamic control on this magmatism. The formation of the F I G U R E 1 2 Geodynamic model showing the Late Mesozoic magmatic activity in the Jiaodong Peninsula (modified after Yang et al, 2021; Late Jurassic adakitic granites indicates the peak of crustal thickening in eastern China (at least 50 km thick) and the beginning of lithospheric delamination and thinning in this region (Figure 12a,b). This was associated with the steepening of the angle and the associated rollback of the subducting Izanagi Plate, causing asthenospheric upwelling, lithospheric extension and thinning, and decratonization in eastern China (Zhu & Xu, 2019), all of which was associated with Early Cretaceous magmatism involving magmas derived from mixed crustmantle sources (e.g.…”

Mesozoic Tectono-Thermal Event of the Qinshui Basin, Central North China Craton: Insights From Illite Crystallinity and Vitrinite Reflectance

“…Previous investigations have been conducted on the destruction of the NCC (Zhu et al, 2012(Zhu et al, , 2017Yang et al, 2021b). According to Zhu et al (2017), at 165 Ma, from the beginning of the Middle Jurassic Yanshanian movement episode A, the West Pacific plate subducted to the East Asian continental margin with a high speed and low angle, the tectonic environment in Qinshui Basin, therefore, corresponds to a compression environment, and angular unconformity events were generally developed.…”