The Qi191 Au deposit is a newly discovered granite-hosted Au deposit in the Qiyugou Au orefield, located in the southern margin of the North China Craton (NCC). Gold ore bodies are hosted by both the Qi191 hornblende monzogranite and the Taihua Complex and are composed of disseminations and sparse veins. K-feldspar, quartz-sericite, and sericite-chlorite alteration formed outward from the center to the periphery of the mineralized granite. Principal ore minerals include galena, pyrite, and chalcopyrite, with minor sphalerite, hematite, pyrrhotite, gold, famatinite, and hessite. The Qi191 Au deposit formed over four successive stages of hydrothermal mineralization: a quartz stage (I), a quartz-pyrite-galena stage (II), an economic quartz-calcite-galena-pyrite stage (III), and a quartz-calcite stage (IV). The Qi191 hornblende monzogranite yields a SIMS zircon U–Pb age of 131.3 ± 1.0 Ma. Hydrothermal sericite yields a plateau ⁴⁰Ar–³⁹Ar age of 132.9 ± 1.4 Ma, which is consistent with the zircon U–Pb age, suggesting that the Qi191 Au deposit is generically related to the hornblende monzogranite. Trace element contents and S isotopic compositions of sulfides indicate that metals and S entered the hydrothermal fluid as pulses. The equilibrium temperature of S and the isotopic compositions of S–Pb reflect a magmatic source. Gold mainly precipitated as native gold in a relatively acidic and reducing environment. This work suggests that further exploration for magmatic hydrothermal gold deposits in the Qiyugou and more widely in the southern margin of the NCC should target hornblende monzogranites such as the Qi191 and Qi189 granitoids.

Qi191 Au矿床是位于华北克拉通（NCC）南部边缘的Qiyugou Au矿田中新发现的花岗岩型Au矿床。金矿体由齐191号角闪长辉长岩和太化岩体共同包裹，由散布和稀疏的脉组成。从矿化花岗岩的中心到外围向外形成钾长石，石英绢云母和绢云母绿泥石蚀变。主要的矿石矿物包括方铅矿，黄铁矿和黄铜矿，以及次要的闪锌矿，赤铁矿，黄铁矿，金，法铁矿和黑铁矿。Qi191 Au矿床是在四个连续的热液成矿阶段形成的：石英阶段（I），石英黄铁矿方铅矿阶段（II），经济石英方解石方铅矿黄铁矿阶段（III）和石英方解石阶段（IV）。Qi191角闪长岩辉长岩产生的SIMS锆石U-Pb年龄为131.3±1.0 Ma。水热绢云母达到平稳状态⁴⁰ Ar– ³⁹ Ar年龄为132.9±1.4 Ma，与锆石U–Pb年龄一致，这表明Qi191 Au矿床一般与角闪长岩辉长岩有关。痕量元素含量和硫化物的S同位素组成表明，金属和S以脉冲形式进入热液。S的平衡温度和S-Pb的同位素组成反映了岩浆源。金主要在相对酸性和还原性的环境中作为天然金沉淀。这项工作表明，在奇玉沟以及在北卡罗来纳州南部边缘更广泛的岩浆热液金矿床的进一步勘探，应该以角闪闪长石变质岩为目标，例如Qi191和Qi189花岗岩。