甘肃寨上金矿床含金石英脉中锆石SHRIMP法U-Pb同位素测定及地质意义

寨上金矿床为西秦岭近年来新发现的大型微细粒浸染型金矿床。矿区出露的地层以泥盆系、二叠系为主，受近SN向挤压作用影响，普遍发生褶皱变形作用。对寨上金矿3件含金石英脉中的锆石样品的SHRIMP法U-Pb同位素年龄实验，结果表明：锆石U-Pb年龄有4个集中分布区间，分别为：1800～2000Ma、800～1000Ma、400～500Ma、300Ma；石英脉中的锆石均为捕获围岩的锆石，没有发现热液锆石；锆石U-Pb同位素年龄印证了矿区及外围缺失二叠系以后古生界及中生界的地层或岩浆岩。

U-Pb isotopic determination by SHRIMP method for Zirconium in gold-bearing quartz veins of Zhaishang gold deposit in Gansu Province and its geological meaning

Zhaishang gold deposit is a recently discovered large micro-particle and disseminated gold deposit in western Qinling.The outcropped strata of the mine district are mainly Devonian and Permian,with popular folding and deforming owing to squeezing actions of approximately SN.Three samples of gold bearing quartz vein ore were tested using ic determination by SHRIMP for Zirconium,and the results show that the U-Pb isotopic ages of Zirconium are distributed in four areas,i.e.,1 800~2 000Ma,800~1 000Ma,400~500Ma,and 300Ma.The Zirconium in the quartz veins are all country rock capturing,without any hydrothermal Zirconium is found.The U-Pb isotopic ages of Zirconium proved that the district is lack of the strata or magma of after Permian period in Paleozoic group and Mesozoic group.