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西藏申扎县甲岗雪山钨钼铋多金属矿床是藏北地区首个发现的内生钨钼铋多金属矿床。矿区共发现钨钼(铋)矿(化)脉22条,主要赋存于白云母化、硅化、云英岩化蚀变的二长花岗岩体及其与石炭系下统永珠组砂岩的内外接触带中。对甲岗雪山钨钼(铋)矿区矿石H、O、S、Pb和稀土元素等分析表明,成矿物质(包括流体和矿质)均主要源自岩浆,成矿温度变化为183-420℃,平均为335℃,具中高温成矿特点。矿化流体应是一种富碱质弱酸性流体,其中成矿物质主要以氟和氯络合物形式迁移。矿石辉钼矿Re-Os同位素模式年龄平均值为21.37Ma,表明矿化形成于喜马拉雅中期,与矿区内的二长花岗岩(U-Pb年龄22.22Ma)接近并略晚于岩体形成时间。揭示出钨钼铋成矿作用与喜马拉雅早-中期二长花岗岩浆活动具有密切的成因联系,为一典型的与中酸性岩浆活动有关的岩浆期后热液石英大脉型钨钼铋多金属共生矿床。
Xuanzang Xishan Tungsten Molybdenum, Bismuth and Polymetallic Deposit in Xaina County, Tibet is the first discovered endogenous tungsten, molybdenum and bismuth polymetallic deposit in northern Tibet. Tungsten and molybdenum (bismuth) ore (chemical) veins have been found in 22 mines, mainly occurring in the monzonitic granodiorites with micaization, silicification and phlogoyal alteration and their interaction with the sandstone of the Lower Carboniferous Yongzhu Formation In contact with the band. The analysis of ore H, O, S, Pb and REE in Xugang Xishan Tungsten Molybdenum (Bismuth) ore deposit shows that the ore-forming materials (including fluids and minerals) are mainly derived from magma, the temperature of ore-forming changes from 183 ℃ to 420 ℃, The average is 335 ℃, with high-temperature mineralization characteristics. The mineralized fluid should be a weak alkali-rich fluid, in which the metallogenic material is mainly migrated as fluorine and chlorine complexes. The average age of the Re-Os isotopic pattern of molybdenite ore is 21.37Ma, indicating that mineralization was formed in the middle of the Himalayas and is close to and slightly later than the monzonite granite (U-Pb age 22.22Ma) in the mining area. It is revealed that the mineralization of tungsten, molybdenum and bismuth is closely related to the magmatic activity of the early-mid-long granitic magmas in the Himalaya. For a typical magmatic activity associated with magmatic activity, the hydrothermal quartz veins of tungsten-molybdenum-bismuth multimetal symbiosis Deposits.