Comparison of characteristics between magmatic core complex and metamorphic core complex and examples of ore control: Tectonic community and ore controlling model of Niushan-Fenghuangshan metamorphic core complex and North Niushan magmatic core complex in the South Qinling Mountains

Taking the metamorphic core complex of Niushan-Fenghuangshan(NFMtCC)in the southern Qinling Mountains and the North Niushan magmatic core complex (NMgCC) as examples, this study compares the characteristics and ore-controlling effects of the two types of core complexes. The research method is to compare and analyze the structural community, metamorphic degree, magma emplacement and deformation era, structural hierarchy and evolution, and ore control characteristics of the nuclear complex, combined with ore control structure alteration lithofacies mapping and dating research. The results indicate that the two types of core complexes have similar structural styles, but there are significant differences in their tectonic communities and evolution. The core of Niushan-Fenghuangshan metamorphic core complex is the Neoproterozoic Wudang rock group and Yaolinghe rock group medium deep metamorphic rock, with Neoproterozoic quartz diorite and Caledonian pyroxene diabase strain, indicating that it was formed in Neoproterozoic or Caledonian. There are detachment faults and ductile shear zones between the core complex and the surrounding Sinian Devonian shallow metamorphic rock. The Meiziya Formation of the Silurian system is a combination of shallow metamorphic and strongly deformed rock slices, with three stages of newly formed foliation and replacement, including multi-level ductile shear, solid-state rheology, detachment thrust strike slip deformation. The core and periphery of the North Niushan magmatic core complex are shallow metamorphic rock, and four intrusive rocks of Neoproterozoic, early Paleozoic, Triassic and Jurassic are found in the core and periphery by mapping and testing. There are two phases of intrusive rock related to the magmatic core complex: Triassic-Early Jurassic monzonitic granite stock (180.2±3.6 Ma, 176.0±1.9 Ma) and Late Jurassic granite vein (156.5 Ma). This research has found that the magma emplacement, ductile shear deformation, and thermal metamorphism accompanied by the magma core complex, as well as the increase of metamorphic phenocrysts, the distribution of natural gold along the S₂ plane, and the hydrothermal alteration of gold mineralization, are all concentrated in the Late Triassic-Jurassic, indicating the spatiotemporal correlation characteristics of the brittle ductile shear deformation, overpass type magma, thermal vertical accretion, and hydrothermal alteration of the magma core complex during the relatively new era of intracontinental orogeny, as well as the direction of deep exploration.