河南桐柏老湾金矿白云母氩-氩年龄及其地质意义  

^(40)Ar-^(39)Ar Age of Muscovite from the Laowan Gold Deposit in Henan and Its Significance

作　　者：张冠[1] 李厚民 王成辉[3] 王登红 李立兴[3] 张建[3] 

机构地区：[1]河南省地质调查院信阳分院,河南信阳464000 [2]中国地质科学研究院矿产资源研究所,北京100037 [3]中国地质科学院研究生部,北京100037

出　　处：《地球学报》2008年第1期45-50,共6页Acta Geoscientica Sinica

基　　金：中国地质调查局“中国成矿体系综合研究”项目(编号:1212010634002);“我国重要矿产和区域成矿规律研究”(编号:1212010633903);“我国西部重要成矿区带矿产资源潜力评估”(编号:200420190004)资助

摘　　要：河南老湾金矿是秦岭—大别造山带中代表性金矿之一,其容矿围岩是元古宙变质岩,矿体受到NWW向老湾剪切带的控制,同时附近又有燕山期花岗岩。结合前人工作,本次研究表明,老湾金矿的形成经历了一个漫长过程,其韧性剪切带的演化(138Ma)早在花岗岩(108～102Ma)之前就开始了。韧性剪切带既是导岩构造也是导矿构造,含金石英脉的定位最晚(91Ma)。这一漫长过程与秦岭—大别造山带在燕山期的演化过程一致。The Laowan gold deposit in Henan Province, one of the most important gold deposits in the Qinling-Dabie orogenie belt, is hosted within Proterozoic metamorphic rocks, controlled by the Lanwan NWW-trending shear zone and related to the nearby Laowan Yanshanian granite. Based on a comprehensive study and a new Ar-Ar age of muscovite from the Au-bearing shear zone, the authors hold that the Laowan gold deposit experienced a long time of evolution： the devel- opment of the shear zone began at 138 Ma, then the granite intruded at 108-102 Ma, and the Au-bearing quartz veins were formed at 91 Ma. These results show that gold mineralization was related to the Yanshanian rnagrnatism, and that the NWW-trending shear zone might have been the main structure controlling the movement of magma and ore-bearing fluids. Thus, the NNW-trending shear zone seems to be the most important target area for further exploration.

关 键 词：老湾金矿 同位素年代学 AR-AR法 剪切带 

分 类 号：P597.1[天文地球—地球化学]