现代地质2013，Vol.27Issue(2)：294-302,9.
藏南拉木由塔锑(金)矿床成矿流体特征及成矿机制初探
The Characteristics of Ore-forming Fluids and Primary Metallogenic Mechanism of the Lamuyouta Sb(Au)Deposit, South Tibet
摘要
Abstract
Lamuyouta Sb ( Au) deposit is located in the eastern section of Sb-Au metallogenic belt, south Tibet. The ore body mainly distributes at the contact between the strata of the Middle Jurassic Zhala Formation and diabase (allgovite) veins. The results show that the dominant fluid inclusion types in quartz are the gas-liquid two-phase inclusions with rich liquid. Those fluid inclusions are generally smaller. All of them are textur-ally complex, display elongated, rounded, oval-shaped and irregular-shaped inclusions. The fluid inclusions in calcite are contrarily bigger. Similarly, all of them are also the gas-liquid two-phase inclusions with rich liquid. However, the texture is rather simple where the negative crystal and irregular shape dominate. The inclusion mi-cro-thermometry results reveal that the homogenization temperatures vary from 150 to 344℃ while the salinities and the densities change from 0. 53% to 9. 61% and 0. 55 to 0. 93 g/cm3 , respectively. The metallogenic pressure is deemed from 39 to 83 MPa, which reflect that the metallogenic process was under mid-low temperature conditions and the ore-forming fluid is of low salinity and low density. The homogeneous temperature and salinity of the fluid inclusions decreased as the ore deposits formed gradually from early to late phases. H-O isotopic studies shows the 5DV_SMOW of ore bearing quartz veins is from - 137 ‰ to - 163 ‰ while δ18OH2O changes from 9. 42‰ to 14. 58‰; the δDV_SMOW of ore bearing calcite veins is from - 148 ‰ to - 151 ‰ while δ18OH2O changes from -9. 83‰ to - 17. 02‰ and the ore-forming fluids are considered to be sourced from the precipitation. The ore-forming material derives from water-rock interaction and mixing of fluids.关键词
流体来源/流体性质/包裹体/锑(金)矿床/拉木由塔/西藏Key words
fluid source/ fluid characteristic / inclusion/ Sb (Au) deposit/ Lamuyouta/ Tibet分类
天文与地球科学引用本文复制引用
杜泽忠,顾雪祥,李关清,章永梅,程文斌,景亮兵,张兴国..藏南拉木由塔锑(金)矿床成矿流体特征及成矿机制初探[J].现代地质,2013,27(2):294-302,9.基金项目
中国地质调查局西藏自治区矿产资源潜力评价项目(1212010813025). （1212010813025）
