(1. 中南大学 有色金属成矿预测教育部重点实验室，长沙 410083；
2. 中南大学 地球科学与信息物理学院，长沙 410083)
摘 要: 三色沟矿区位于我国著名成矿带之一的东昆仑造山带中部，矿区出现的主要矿化类型包括脉型铅锌矿化和斑岩型铜矿化。流体包裹体研究表明，三色沟矿区流体包裹体类型包括气液两相水溶液包裹体(Ⅰ型)、水溶液−CO2包裹体(Ⅱ型)和纯CO2包裹体(Ⅲ型)。成矿流体具有低盐度、低密度的特点，铅锌成矿温度下限值为178~209 ℃，盐度为0.3%~18.8%(NaCleq)，估算成矿压力为50~143 MPa；铜矿化成矿温度下限值为182~228 ℃，盐度为3.5%~18.8%(NaCleq)，估算成矿压力为71~164 MPa。成矿过程中流体发生相分离，对多金属硫化物的沉淀起到重要作用。结合矿区的地质演化史，认为矿区中部与岩浆热液作用有关的斑岩型铜矿化，与区内强烈发育的铅锌矿化均为同一构造−岩浆作用的产物。
关键字: 流体包裹体；成矿流体；东昆仑；三色沟；矿床成因
Sansegou Pb-Zn deposit in Qinghai Province, China
（1. Key Laboratory of Metallogenic Prediction of Nonferrous Metals, Ministry of Education,
Central South University, Changsha 410083, China;
2. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China）
Abstract:The Sansegou Pb-Zn deposit is located in the eastern Kunlun orogenic belt, one of the famous metallogenic belt in China. The main mineralized types in the deposit are vein-type Pb-Zn mineralization and porphyry-style copper mineralization. Fluid inclusion studies indicate that the fluid inclusions are in three types: two-phase aqueous inclusion (typeⅠ), three-phase CO2-aqueous fluid inclusion (type Ⅱ) and pure CO2 fluid inclusion (type Ⅲ). The ore-forming hydrothermal fluids are characterized by low salinity, low density, and the Pb-Zn mineralizing temperatures range from 178 to 209 ℃, low salinities range from 0.3% to 18.8% NaCl equivalent, and the calculated pressure ranges from 50 to 143 MPa; the porphyry copper mineralizing temperatures range from 182 to 228 ℃, salinities range from 3.5% to 18.8% NaCl equivalent, and the calculated pressure ranges from 71 to 164 MPa. The immiscibility of ore-forming fluids plays an important role in the metallogentic process of Pb-Zn-Cu deposit. Associated with the tectonic environment, it is suggested that the porphyry-style copper mineralization in the central part of the ore district which is related to magmatic hydrothermal activities is the result of the same tectionic-magmatic activities as Pb-Zn mineralization.
Key words: fluid inclusions; ore-forming fluid; eastern Kunlun; Sansegou; deposit genesis
