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利用白钨矿对金属矿床进行了Sm-Nd同位素定年。研究结果表明,湘西沃溪Au-Sb-W矿床中白钨矿的Sm,Nd含量较高,Sm/Nd值较大.在~(147)Sm/~(144)Nd-~(143)Nd/~(144)Nd图解中,浸染状白钨矿样品呈良好的线性分布,其对应的等时线年龄为402±6Ma,ε_(Nd)(t)值为-30.7。该矿两个石英样品的~(40)Ar-~(39)Ar年龄谱均呈“马鞍型”,样品的最小视年龄、坪年龄和等时线年龄基本一致,其最小视年龄(420±20和4 14±19Ma)与白钨矿的Sm-Nd同位素数据相当吻合.白钨矿的Sm-Nd年龄和石英Ar-Ar年龄均表明沃溪矿床形成于加里东晚期,这与湖南雪峰山地区的构造演化和一些金锑钨矿床的同位素年代数据相吻合。白钨矿的初始ε_(Nd)值异常低,远低于湖南元古宇地层的相应值,成矿流体中的Nd很可能来自下伏的更老的陆壳基底.对该矿成矿时间的厘定和对其成矿物源的制约为进一步认识其矿床成因奠定了基础.
Sm-Nd isotope dating of metal deposits has been performed using scheelite. The results show that the scheelite in the Woxi Au-Sb-W deposit in western Hunan Province has a higher content of Sm and Nd and a larger value of Sm / Nd. In the presence of ~ (147) Sm / ~ (144) Nd- ~ In the ~ ~ (144) Nd diagram, the samples of disseminated scheelite show a good linear distribution with corresponding isochron age of 402 ± 6Ma and ε_ (Nd) (t) of -30.7. The ages of ~ (40) Ar- ~ (39) Ar ages were all “saddle-shaped” in the two quartz samples of this mine. The minimum age of the samples, plateau age and isochron age were basically the same. 20 and 4 14 ± 19Ma), which are in good agreement with the Sm-Nd isotope data of scheelite.The Sm-Nd ages of scheelite and quartz Ar-Ar age all indicate that the Woxi deposit was formed in the late Caledonian, The tectonic evolution of the area coincides with that of some gold-antimony-tungsten deposits. The initial ε_ (Nd) value of scheelite is abnormally low, which is much lower than that of the Proterozoic stratigraphy in Hunan, and the Nd in the ore-forming fluid is likely to originate from the underlying older continental crust basement. The determination and restriction of the metallogenic source has laid the foundation for further understanding of the genesis of the deposit.