The Wulaxi tungsten deposit is located in the southeastern Songpan-Ganzi orogenic belt. Based on considerable geological surveys and research, we suggest that this deposit belongs to skarn type tungsten deposit with a medium scale prospect. In this contribu⁃tion, Re-Os dating has been determined for the molybdenites from the Wulaxi tungsten deposit, which occurred as quartz veins and were spatially related to the scheelites. The analytical results yield model ages ranging from 161.5±2.2 to 165.3±2.2 Ma with a weighted mean age of 163.7±1.9 Ma (n=6, MSWD=0.42, 95%conf.), and a good isochron age of 161.0±3.7 Ma (n=6, MSWD=0.87, 2σ). The Re-Os geo⁃chronological signals show that the W-Mo mineralization occurred in the late stage of Middle Jurassic, slightly post-dated the formation of ore-bearing granite, indicating that it might be a product of the Yanshanion tectonic-magmatic-hydrothermal event in the region. The ore-forming source was possibly derived from the Proterozoic Liwu Group complex. In addition, there is favorable potential for ore pros⁃pecting at greater depths.%乌拉溪钨矿位于松潘—甘孜造山带东南缘，该地区的钨矿床鲜有报道。本研究在进行大量的地质调查工作后，基本确认该矿床为一具有中型规模远景的矽卡岩型矿床；并通过对该矿床中与白钨矿共生的辉钼矿进行Re-Os同位素测年，获得6件样品的模式年龄介于161.5±2.2~165.3±2.2 Ma之间，加权平均年龄为163.7±1.9 Ma （MSWD=0.42，95%conf.），等时线年龄为161.0±3.7 Ma （MSWD=0.87，2σ）。该研究结果表明乌拉溪钨矿形成于中侏罗世晚期，略晚于乌拉溪花岗岩体，属燕山期构造—岩浆—热液成矿事件下的产物；成矿物质可能来源于元古界里伍岩群，矿区深部可能有更好的找矿前景。
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