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

作者：Gao Zuoyu; Liu Yunhua^*; Sun Naiquan; Li Yuntao; Li Bo

来源：ACTA GEOLOGICA SINICA-ENGLISH EDITION, 2022, 96(3): 993-1009.

DOI：10.1111/1755-6724.14916

• stable isotope
• metallogeny
• quartz-pyrite veins
• collisional orogeny
• South Qinling Orogen

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 delta S-34 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.

• 单位
  桂林理工大学; 长安大学