班公湖-怒江成矿带是西藏自治区重要的铜金多金属成矿带,东西延伸约2000 km,南北两侧与拉萨地块和羌塘地块相接.随着研究程度的深入,近已发现成矿带中铋的矿化呈带状展布.尕尔穷是该成矿带中重要的矽卡岩型铜金矿床,笔者通过野外地质调查采样、显微镜鉴定、扫描电镜观察和能谱成分分析,在矿石中首次发现铋的独立矿物——辉铋矿,这也是班公湖-怒江成矿带中首次发现的重要铋工业矿物.此外还有含锇自然铋、硫铜铋矿、碲铋矿、含硫碲铋矿、未定名的BiTe2等铋的自然元素矿物、碲化物及硫盐矿物.研究成果丰富了成矿带铋矿物种类,对矿床研究和勘查方向的确定有着重要的指示意义.根据镜下鉴定和流体包裹体测温讨论了Cu-Au-Bi共生关系,铋在成矿热液中以硫络合物形式迁移,辉铋矿在高温热液下形成.尕尔穷铜金矿床的含矿岩体LA-ICP-MS锆石U-Pb年龄83.2～87.1 Ma,辉钼矿Re-Os模式年龄86.87～87.29 Ma,矿床类型为岩浆热液接触交代成因的矽卡岩型铜金矿床.%Bangong Lake-Nujiang River metallogenic belt is an important copper-polymetal ore belt in Tibet. It extends about 2000 km from east to west, bounded by the Lhasa block to the south and the Qiangtang block to the north. With investigation deepening,it was found that bismuthic mineralization is distributed in the shape of belt. Garqiong is one of the places which hosts the key skarn-type copper-gold deposit in the metallogenic belt. Based on field geological investigation and sampling, and microscope and SEM analysis, an independent bismuth-bismuthinite mineral was identified, and it is an important Bi-bearing mineral ever found in the Bangong Lake-Nujiang River metallogenic belt. In addition, Osmium-bearing native bismuth, emplectite, tetradymite, sulfur-containing tetradymite unnamed BiTe2 and other natural elements minerals of the bismuth,telluride and sulfate mineral were also found. The research results have enriched the variety of bismuth minerals and have great importance in deposit research and in determining the direction of future prospecting. Based on microscope identification and fluid inclusion temperature, paragenetic relation between Cu-Au and Bi, migration of Bi in ore-forming fluid as sulfur complex, and formation of bismuthinite in the high T hydrothermal fluid were all discussed in this study. U-Pb dating of zircon from the ore-bearing rocks is 83. 2~87. 1 Ma using LA-ICP-MS, and the Re-Os model ages of molybdenite are between 86. 87~87. 29 Ma in the Garqiong copper-gold ore deposits. The deposit should belong to skarn-type copper-gold ore deposits resulted from magmatic hydrothermal contact metasomatism in origin.
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