This research was funded by the National Natural Science Foundation of China (Grant No. 41872219); Key Research and Development Program of Shaanxi [2019SF-245]; Integrated Research Project of Integrated Exploration of China Geological Survey [WKZB1911BJM300369/002]; China Geological Survey Program, and Ministry of Natural Resources (Grant No. DD20179607), and Fundamental Research Funds for the Central Universities, CHD (Grant No. 300102271722).
The Taishanmiao Au deposit is in the western part of the Ningshan–Zhenan ore field, in the South Qinling orogen. Based on geological and geochemical features, we propose that the Taishanmiao Au deposit is a magmatic-hydrothermal type of deposit. All samples have high SiO2, K2O + Na2O contents and differentiation index values, low CaO, MgO, P2O5, and TiO2 contents, are enriched in high field-strength elements, and depleted in large ion lithophile element. The stable isotope δ34S values of pyrite vary from 6.8%–7.8%, and the H-O isotopic compositions of quartz from quartz-pyrite veins indicate the ore-forming fluid is a mixture of a small amount of magmatic-hydrothermal solution and groundwater. Lead isotope ratios of pyrite and silicalite can show that the ore-forming materials were derived from a mixed source containing mantle and crustal materials. At the same time, the LA-ICP-MS U-Pb dating of monzogranite is 198.4 ± 4.2 Ma. Combined with the regional geological background, the intracontinental extension in the late collisional orogeny and large-scale lithospheric thinning associated with mantle uplift may lead to large-scale mineralisation in the region.
GAO Zuoyu, LIU Yunhua, SUN Naiquan, LI Yuntao, LI Bo.2022. Genesis of the Taishanmiao Au Deposit in the Ningshan–Zhenan Ore Field, South Qinling Orogen, China: Evidence from Geochemical, Geochronological and S-Pb-H-O Isotopical Study[J]. Acta Geologica Sinica(),96(3):993-1009Copy