西秦岭西成铅锌矿田赋矿安家岔组碎屑锆石U-Pb年龄及其地质意义  

Zircon U-Pb Age and Its Geological Significance of the Anjiacha Formation in Xicheng Pb-Zn Orefield,Western Qinling

作　　者：浩德成[1] 丁振举[2] 高兆奎[3] 韩要权[4] 周宏[3] HAO Decheng;DING Zhenju;GAO Zhaokui;HAN Yaoquan;ZHOU Hong(Lanzhou Mineral Exploration Institute of Gansu Nonferrous Metal Geological Exploration Bureau,Lanzhou,Gansu 730046,China;School of Earth Resources,China University of Geosciences,Wuhan,Hubei 430074,China;Gansu Nonferrous Metal Geological Exploration Bureau,Lanzhou,Gansu 730000,China;Information Center of Gansu Nonferrous Metal Geological Exploration Bureau,Lanzhou,Gansu 730000,China)

机构地区：[1]甘肃省有色金属地质勘查局兰州矿产勘查院,甘肃兰州730046 [2]中国地质大学(武汉)资源学院,湖北武汉430074 [3]甘肃省有色金属地质勘查局,甘肃兰州730000 [4]甘肃省有色金属地质勘查局信息中心,甘肃兰州730000

出　　处：《现代地质》2021年第2期552-567,共16页Geoscience

基　　金：2010年度省级矿产资源补偿费资助项目“甘肃省西秦岭代家庄-厂坝地区铅锌多金属找矿潜力研究”(201001-Y03)。

摘　　要：西秦岭西城铅锌矿田秦岭型铅锌矿床产于中泥盆统碳酸盐岩和细碎屑岩系中,经热液沉积或热液沉积改造而成。厂坝—李家沟特大型铅锌矿床附近安家岔组地层受区域变质和接触热变质作用的影响,变质程度较高的黑云母石英片岩分布广泛。对厂坝—李家沟特大型铅锌矿床赋矿安家岔组黑云母石英片岩开展碎屑锆石U-Pb定年,查明安家岔组地层时代应晚于(401±6)Ma;结合岩石地球化学分析,认为其沉积构造环境以活动大陆边缘为主,可能为早—中泥盆世扬子板块北缘断陷盆地沉积的产物,沉积碎屑物源来自扬子克拉通与北秦岭地区。The Qinling-type Pb-Zn deposit in the Xicheng Pb-Zn orefield(west Qinling orogen)is hosted in Middle Devonian carbonate and fine-clastic sequences,and was formed or transformed by hydrothermal sedimentation.The Anjiacha Formation near the Changba-Lijiagou super-large Pb-Zn deposit is affected by regional metamorphism and contact metamorphism,and high-grade biotite-quartz schist is widely distributed.Detrital zircon U-Pb dating of the biotite-quartz schist yielded a maximum age of(401±6)Ma.Combined with lithogeochemical evidence,it is considered that the sedimentary structural environment was mainly active continental margin,which was likely the product of Early-Middle Devonian fault basin in the northern margin of Yangtze plate.The detrital provenance may have been the Yangtze Craton and north Qinling region.

关 键 词：安家岔组 泥盆世 碎屑锆石 U-PB年代学 岩石地球化学 西成铅锌矿田 

分 类 号：P618[天文地球—矿床学] P597[天文地球—地质学]