湖南渣滓溪W-Sb矿床白钨矿Sm-Nd测年及其地质意义  

Scheelite Sm-Nd dating of the Zhazixi W-Sb deposit in Hunan and its geological significance

作　　者：王永磊[1] 陈毓川[2] 王登红[1] 徐珏[1] 陈郑辉[1] 

机构地区：[1]中国地质科学院矿产资源研究所,国土资源部成矿作用与资源评价重点开放实验室,北京100037 [2]中国地质科学院,北京100037

出　　处：《中国地质》2012年第5期1339-1344,共6页Geology in China

基　　金：全国矿产资源潜力评价项目(1212010633901);深部探测技术与实验研究专项之南岭成矿带地壳岩浆系统结构探测试验课题(Sinoprobe-03-01);中国地质调查局地质大调查之我国重要矿产和区域成矿规律研究项目(1212010633903)共同资助

摘　　要：渣滓溪W-Sb矿床位于湘西雪峰山弧形构造带的中段,是典型脉状W-Sb矿床。本文对渣滓溪矿区的白钨矿进行了Sm-Nd同位素研究。研究表明,其白钨矿的Sm/Nd变化范围为0.2175-0.3485,在白钨矿的147Sm/144Nd-143Nd/144Nd图解中,对应的等时线年龄为(227.3±6.2)Ma,MSWD=1.6,是白钨矿的形成年龄,代表了渣滓溪W-Sb矿床的主成矿年龄,属于晚三叠纪。渣滓溪W-Sb矿床白钨矿的εNd(t)值为-11.81--11.91,不同于沃溪W-Sb-Au矿床白钨矿的εNd(t),暗示两者在成矿物质来源上具有一定差异。本次白钨矿Sm-Nd同位素等时线年龄研究结果进一步明确了渣滓溪W-Sb矿成矿年龄,为研究湘西W-Sb多金属矿床成矿年龄及湘西的成矿时空特征提供了可靠和有用的数据,而渣滓溪W-Sb矿床晚三叠纪成矿时代的确定对于区域找矿也具有重要意义。Located in central Xuefeng Mountain arc structural belt,the Zhazixi W-Sb deposit is a typical vein deposit.The Sm-Nd isotope dating of scheelite from the Zhazixi W-Sb deposit was performed in this paper,and the result shows that the Sm/Nd ratios vary from 0.2175 to 0.3485.In the 147Sm/144Nd versus 143Nd/144Nd diagram,the scheelites show a good linear arrangement and yield an isochron age of 227.3±6.2 Ma（MSWD=1.6）.The Sm-Nd age represents the formation age of the scheelite and can indicate that the W and Sb mineralization in Zhazixi district took place in late Triassic period.εNd（t） values of the samples vary from-11.81 to-11.91,quite different from the values of the Woxi W-Sb-Au deposit,indicating that the two deposits were derived from obvious different sources for ore-forming materials.This study is important for the study of the polymetallic resources in western Hunan Province,and also contributes to regional prospecting.

关 键 词：白钨矿 SM-ND同位素 W-Sb矿床 湖南渣滓溪 

分 类 号：P597.3[天文地球—地球化学]