马元铅锌矿床角砾岩成因及成矿地质背景  

Origin of the breccia and metallogenic geological background of Mayuan Pb-Zn deposit

作　　者：韩一筱 刘云华[1,2] 刘淑文[1,2] 雷万杉[1,2] 李真[1,2] 李云涛[1,2] 李兴[1,2] 

机构地区：[1]长安大学地球科学与资源学院,陕西西安710054 [2]国土资源部岩浆作用成矿与找矿重点实验室,陕西西安710054

出　　处：《地学前缘》2016年第4期94-101,共8页Earth Science Frontiers

基　　金：陕西有色集团科研项目([2013]0425);中央高校基金项目(310827153407)

摘　　要：马元铅锌矿床是中国近年来在扬子板块北缘南大巴山陆内造山带中发现的大型铅锌矿床。对矿田构造的研究发现,成矿作用受震旦系灯影组白云岩地层层间破碎带的控制。破碎带中见大量紧闭褶皱转折端角砾,下盘附近发育层间剪切滑移断层带,显示控矿构造为低角度逆冲推覆过程中形成的断层褶皱和与之相关的角砾岩。矿质充填在破碎带白云岩角砾间的空隙中,矿石的晶洞-梳状构造发育,未见后期破坏,表明矿床形成于构造定型期。对成矿晚期热液沥青进行Re-Os同位素年龄测试,获得(126±8)Ma的等时线年龄,结合区域构造背景,认为该矿床形成于中晚侏罗世。控矿构造角砾岩为低角度逆冲推覆构造作用的产物。Mayuan Pb-Zn deposit is a large Pb-Zn deposit discovered in the South Dabashan intracontinental orogenic belt of the northern Yangtze plate recent years in China.According to the research of orefield structure,the mineralization was controlled by interlayer fracture zones of Sinian Dengying dolomite formation.Because of the large number of breccias at the bending of the tight folds in fracture zone,and the interstratified shearing glide fault zone near the footwall,it is suggested that the ore-controlling structure is a kind of fault-fold occurring during the low angle thrust-napping procedure and the associated breccia.When mineral filled in the gap between the dolomite breccias of fracture zones,the miarolitic structure and comb structure of ore grew without destruction in the late period,which demonstrated that the deposit was formed during the structural forming stage.At the same time,we have got Re-Os isotopic dating from the late mineralization asphalt with an isochron age of 126±8Ma.Considering the tectonic setting,we believe that the deposit was formed in the middle-late Jurassic.The ore-controlling tectonic breccias are the product of the low angle thrust-napping structural effect.

关 键 词：马元 铅锌矿 角砾岩 成因 

分 类 号：P613[天文地球—矿床学] P618.4[天文地球—地质学]