The Wuxi gold deposit is located in Langqiao town, Jingxian county in South Anhui province, which is situated in the Jiangnan orogen, between the Middle and Lower Yangtze polymetallic metallogenic belt and South China metallogenic belt. The LA-ICP-MS dating results for zircons from the drill samples and outcrop rock in ore-bearing granite porphyry are consistent, 139.6±1.7 Ma(ZK7301), 137.3±1.6 Ma(ZK7001), 137.3±1.1 Ma (10WX-1), respectively. This intrusion is controlled by fault structure, and slightly contaminated by the early Archean crustal material. The developed cryptoexplosive breccia and mineralized breccia indicated the Wuxi orebody and granite porphyry were formed contemporaneously. The Wuxi granite porphyry is characterized by peraluminous, enriched in LILE (large ion lithophile elements), depleted in HFSE (high field strength elements) and heavy rare earth elements, significant differentiation between LREE and HREE, slight Eu negative anomaly. The apatite from the Wuxi granite porphyry has similar REE characteristics with those of the Yangtze series, indicating it was affected by mantle derived magmatic fluid activities; and the highδEu value of the apatite implies open tectonic environment and high oxygen fugacity during magma evolution. Zircon oxygen fugacity calculation indicates the granite porphyry formed in a high oxygen fugacity condition, thus it is conducive for precipitation and mineralization of Cu, Au and other ore-forming elements. While the formation of the Wuxi granite porphyry was closely related to the subduction and collision of the Paleo-pacific plate. The developed faults in the deposit provided channels for ore-forming fluid migration, which is conducive to the mineralization. Further prospecting and geochemical work are necessary for the area.%皖南乌溪金矿床位于安徽省泾县榔桥镇，介于长江中下游多金属成矿带与华南成矿带之间，属于江南造山带。本文对乌溪含矿花岗斑岩钻孔样品以及地表出露的岩体开展锆石LA-ICP-MS定年，分别获得139.6±1.7 Ma(ZK7301)、137.3±1.6 Ma(ZK7001)、137.3±1.1 Ma(10WX-1)三组年龄，表明钻孔中的斑岩和地表出露的岩体年龄一致，形成于燕山期早白垩世。同时该岩体主要受断裂构造控制，在成岩过程中受到少量新太古代地壳物质的混染。岩体中发育大量的隐爆角砾岩以及矿化角砾，表明乌溪矿床的矿体与花岗斑岩岩体可能同时形成。乌溪花岗斑岩元素分析结果表明该岩体属过铝质，具有富集大离子亲石元素，亏损高场强元素以及重稀土元素的特征，其中轻重稀土元素分异显著，且具有轻微 Eu负异常。乌溪花岗斑岩中的磷灰石与长江系列花岗岩的磷灰石稀土特征相似，表明该区磷灰石的稀土元素特征受到幔源岩浆流体活动的影响；同时因为磷灰石δEu 值较高，说明岩浆在演化过程中处于相对开放的构造环境并且具有较高的氧逸度条件。锆石氧逸度计算表明乌溪花岗斑岩在形成过程中具有较高的氧逸度，有利于 Cu、Au 等成矿元素富集沉淀成矿。同时乌溪花岗斑岩的形成与古太平洋板块对欧亚大陆的俯冲碰撞作用密切相关。乌溪金矿床的矿体中 Pb、Zn 元素出现明显的矿化， Au元素含量相对大陆地壳略高。乌溪金矿矿区内发育的大量断裂构造为成矿流体提供了充分的运移通道，有利于金矿的形成；进一步的野外勘测以及地球化学工作对乌溪矿区探矿和找矿工作具有重要的指示意义。
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