中文摘要：

本文对湘西沃溪W-Sb-Au矿床白钨矿进行了系统的Nd—Sr—Pb同位素分析。结果表明，白钨矿的Sm、Nd含量较低，^147Sm／^144Nd（0．64～1．27）值和Sm／Nd值（1．11～2．22）变化较大，其εNd（t=199Ma）值也很低，平均为-25．5（n=9）；白钨矿的^87Sr／ε84Sr值（0．7476～0．7504）高，平均为0．74961（n=11），代表白钨矿形成时的初始^87Sr／^86Sr（t=199Ma）值；逐级分离Pb同位素分析结果显示白钨矿的^206Pb／^204Pb、^207Pb／^204Pb、^208Pb／^204Pb值变化范围小，平均依次分别为18．11、15．61、38．6，与含金石英脉中黄铁矿、蚀变围岩及区域板溪群板岩等的相应Pb同位素比值基本一致。白钨矿Nd—Sr—Pb同位素组成和闪锌矿等其他矿物的Sr同位素特征指示成矿流体来自：板溪群下伏成熟陆壳、深部花岗质岩浆、浅部赋矿围岩等源区。成矿流体是这些来自不同源区的流体相作用而形成的混合流体。成矿作用则是这些不同源区的流体混合作用并演化的结果。且成矿流体演化早期是来自下伏成熟陆壳的流体与来自赋矿围岩的流体混合，导致早期W成矿；晚期是来自深部花岗质岩浆的流体与浅部赋矿围岩的流体混合作用，导致晚期Sb—Au成矿。W—Sb—Au成矿则是中生代陆内碰撞造山体制下不同期次的流体演化和叠加作用的结果。

英文摘要：

This study carries out a systematic Nd-Sr-Pb isotopic analyzing on scheelites from the V4 ore vein of the Woxi W-Sb-Au ore deposit in western Hunan, China. The results show that the Sm and Nd concentrations in scheelite are a bit lower, with variable ratios of Sm/Nd （1.11 ～ 2.22） and ^147Sm/ ^144Nd （0. 64 ～ 1.27）, and the εNd values （compared to values at 199Ma） of scheelite are also low, ranging from -27.4 to -19.9 with an average of -25.5 （n = 9）. The ^87Sr/^86Sr ratios of scheelite are high, varying from 0. 7476 to 0. 7504 with an average of 0. 7496 （n = 11）, which represents the initial ^87Sr/^86Sr ratio of scheelite at 199 Ma. Lead-step leaching analyzing results show that the ratios of ^206Pb/^204pb, ^207Pb/^204Pb, and ^208Pb/^204Pb of scheelite are in narrow variety with averages of 18.11, 15.1, and 38.6, respectively, and these ratios of scheelites are similar to the corresponding ratios of the pyrite from the same gold-bearing quartz veins, of the alternated host rocks, and of the regional slates of the Banxi Group. The above Nd-Sr-Pb isotopic data of scheelite, complementing with previous results of Sr isotopes of sphalerite and stibnite, show that the ore-forming fluids for the mineralization might include the following possible source fluids： fluid from the ancient continental crust beneath the host rock （the Banxi Group）, fluid from deep granitoid magmas, and fluid from the host rock. The ore-forming fluid is a mixture of the above source fluids. The mineralization most possibly was due to the mixing of the above fluids of different sources, and the ores might be the products of mixing the fluids from different sources. The fluid evolution might include two major stages： The early stage was probably characterized by mixing the upward fluid from the ancient continental crust underneath the host rock （the Banxi Group）, with those from the host rock. This early stage of fluid mixing might have led the early stage of mineralization represented by tungsten ores. The la