投稿时间：2012-02-01
修订日期：2012-10-29
中文摘要:通过对东沟铜矿床的成矿特征、流体包裹体地球化学以及矿床成因研究,获得了如下认识:① 成矿环境为晚寒武世的大洋扩张脊环境,容矿岩石为蛇绿岩套上部的基性火山岩,矿床成矿金属组合为Cu-Zn(少量),围岩蚀变主要有硅化、绿泥石化、碳酸盐化及绿帘石化等,其中,硅化、绿泥石化与矿体的关系最为密切;② 对不同类型矿石中黄铁矿、黄铜矿的电子探针分析均表明,具有低温或中低温热液成矿的特征;③ 流体包裹体地球化学研究表明,该区成矿期石英中包裹体类型简单,仅有纯液体包裹体和液体包裹体,气相分数低,液体包裹体气相成分以CO2为主,液相成分主要为H2O;矿床成矿流体温度为150～200℃,盐度w(NaCleq)为13%～16%,密度为0.87～0.95 g/cm3;④ 矿床属于"塞浦路斯"型块状硫化物矿床。关键字 地球化学;成矿特征;流体包裹体;塞浦路斯型矿床;东沟铜矿;北祁连
Abstract:Based on a study of ore-forming characteristics, fluid inclusion geochemistry and genesis of the Donggou copper deposit, the authors obtained the following understanding: ① The metallogenic environment was an oceanic spreading ridge environment in Late Cambrian, the ore-bearing rocks were mafic volcanic rocks in the upper part of the ophiolite, the ore-forming metals were of Cu-Zn combination, and the wall-rock alterations included silicification, chloritization, carbonatization and epidotization, with silicification and chloritization having the most close relationship with the ore body. ② Electron microprobe analyses of pyrite and chalcopyrite in different ores show low-middle temperature hydrothermal mineralization characteristics. ③ Geochemical studies of fluid inclusions show that inclusion types in quartz are rather simple and comprise only pure liquid inclusions and gas-liquid inclusions, with low gas-liquid ratio, and gas-liquid two-phase inclusions and liquid inclusions are mainly composed of CO2 and H2O respectively. Ore-forming fluids have temperature of 150～200℃, salinity of w(NaCleq)13%～16%, and density of 0.87～0.95 g/cm3. ④ Mineralization types are of "Cyprus" type massive sulfide deposit.
keywords:geochemistry mineralization characteristics fluid inclusions Cyprus-type deposit Donggou copper deposits North Qilian
文章编号：
中图分类号：P618.41
文献标志码：
基金项目:本文得到青藏专项"北祁成矿带成矿条件研究与找矿靶区优选"(编号:1212010818090)、 "北山-祁连成矿带地质矿产综合研究"(编号:1212010010405)"资助
引用文本：
武鹏,马彦青,李向民,徐学义,余吉远,王国强,唐卓,韩媛.2012.青海省祁连县东沟铜矿床成矿特征及成因研究[J].矿床地质,31(6):1337~1349WU Peng,MA YanQing,LI XiangMin,XU XueYi,YU JiYuan,WANG GuoQiang,TANG Zhuo,HAN Yuan.2012.Metallogenic characteristics and genesis of Donggou copper deposit in Qilian County, Qinghai Province[J].Mineral Deposits31(6):1337~1349
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