Objective The Qinling metallogenic belt is one of China’s most important Au–polymetallic metallogenic belts and the country’s second-largest Au-metallogenic belt after Jiaodong. In recent years, new breakthroughs have been achieved in many deposits such as Zaozigou, creating an urgent need for in-depth research on its Au-metallogenic regularities and resource potential.
Methods Based on a systematic review of strata, structures, magmatism, geophysical–geochemical characteristics, and the metallogenic setting, mineralization features, and ore-controlling factors of 613 Au deposits (or occurrences) within the belt, this study reveals that Au deposits in the Qinling metallogenic belt display a spatial pattern of “NW-trending belts and NE-trending clusters.” Large Au deposits commonly occur at the intersections of NW- and NE-trending structures and in areas with intense magmatic activity.
Results and Conclusion The Au metallogenesis of the eastern and western Qinling exhibits significant differences. In western Qinling, most Au deposits are hosted in the Devonian, Permian, and Triassic strata, with mineralization ages concentrated at 250～230 Ma and 225～210 Ma, closely related to contemporaneous magmatism. Metallogenic types include hydrothermal type hosted in metamorphosed clastic rocks and magmatic-hydrothermal type. In eastern Qinling, Au deposits are mainly hosted in the Archean Taihua Group, the Cambrian, and the Devonian strata, with mineralization ages primarily between 145 and 110 Ma. Their metallogenic type is mainly magmatic-hydrothermal type. For crustal structure, western Qinling shows crustal decoupling influenced by the expansion of the Tibetan Plateau, with deep magmatic channels controlling the distribution of Au deposit districts. In contrast, eastern Qinling exhibits high-conductivity crust–mantle penetrating structures influenced by the Paleo-Pacific Plate, contributing to the Yanshanian metallogenesis. Through comprehensive comparison, this study delineates 25 fourth-order Au metallogenic sub-belts and 10 Au metallogenic series within the Qinling metallogenic belt. Among these, the two most important series are the Indosinian series related to intermediate–felsic magmatic intrusions and the Yanshanian series associated with magmatic–hydrothermal activity. Integrating geological, geophysical, and geochemical information, 73 prospective Au exploration targets are identified within the Qinling metallogenic belt (28 Class I, 34 Class II, and 11 Class III). Based on the metallogenic regularities and resource-potential assessment, It is suggested that exploration in western Qinling should focus on the Xiahe–Hezuo and Zhaishang–Liba ore districts, targeting the deep and peripheral zones of existing deposits. In addition, exploration should also be strengthened in Huayagou–Jiutiaogou, FengTai, and other prospective areas, and particular attention should be given to concealed orebodies related to magmatic-hydrothermal activity in the Wenxian–Kangxian ore district. In eastern Qinling, the application of integrated geophysical techniques should be enhanced for deep-level exploration. Deep exploration should be prioritized in the Xiaoqinling ore district, with special attention to deep and peripheral zones of known deposits such as Xiajiadian, Liujiaxia, and Sulinggou.
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