投稿时间：2015-06-02
修订日期：2016-01-14
网络发布日期：2016-04-29
中文摘要:河南省嵩县七亩地沟金矿床位于华北克拉通南缘的熊耳山地区。矿床赋存在中元古代熊耳群中酸性火山岩中,矿体严格受构造断裂带控制,主要呈脉状产出,矿石以石英脉型占主导,少量蚀变岩型;主要矿石矿物为黄铁矿、少量方铅矿、闪锌矿、黄铜矿等。围岩蚀变以硅化、绢云母化、绿泥石化和碳酸盐化为主。成矿过程从早到晚可分为3个阶段:石英-黄铁矿阶段、黄铁矿-石英-多金属硫化物阶段和石英-方解石阶段。不同成矿阶段的石英和/或方解石中广泛发育流体包裹体。早阶段和中阶段石英中CO2型流体包裹体、NaCl-H2O型流体包裹体、含子矿物流体包裹体均有发育,晚阶段方解石中主要发育NaCl-H2O型流体包裹体。从早阶段到晚阶段,流体包裹体均一温度分别为254~397℃、221~397℃、162~237℃,盐度w(NaCleq)从早阶段的3.52%~21.88%和34.95%~45.33%双峰值,经中阶段的0.42%~13.83%和29.11%~42.48%双峰值,到晚阶段w(NaCleq)为0.35%~5.86%。CO2型包裹体估算的早阶段和中阶段捕获压力为93~199 MPa和47~169 MPa,晚阶段NaCl-H2O型包裹体估算的捕获压力为28~64 MPa,相应的成矿深度为3.4~7.2 km、1.7~6.2 km和2.9~6.5 km,指示成矿发生在地壳隆升过程中,区域应力场由挤压向伸展转变。流体沸腾作用是导致硫化物和金等成矿物质快速沉淀的主要机制,通过沸腾和大气降水的混合,成矿流体系统由富CO2向贫CO2流体演化,由变质流体向大气降水演化。
Abstract:The Qimudigou gold deposit in Songxian County, Henan Province, is located in Xiongershan area on the southern margin of the North China Craton. There exist acidic volcanic rocks of Mesoproterozoic Xiong'er Group in the deposit, orebodies are strictly controlled by the veinlike tectonic faulted zones, and quartz vein type is dominant in the ore, with a small amount of alteration rock type. The main ore mineral is pyrite, with a small amount of galena, sphalerite, and chalcopyrite. Wall rock alterations include silicification, sericitization, chloritization and carbonatization. The ore-forming process can be divided into three stages: quartz-pyrite stage, pyrite-quartz-polymetallic sulfide stage and quartz-calcite stage. Fluid inclusions are widely distributed in quartz and/or calcite of different ore-forming stages. Early stage and middle stage quartz contains CO2 fluid inclusions, NaCl-H2O type fluid inclusions, daughter minerals-bearing fluid inclusions. Late stage calcite mainly contains NaCl-H2O type fluid inclusions. From early stage to late stage, homogenization temperatures of fluid inclusions were 254~397℃, 221~397℃, and 162~237℃, the salinity evolved from early stage bimodal salinity w(NaCleq) values 3.52%~21.88% and 34.95%~45.33%, through the middle stage bimodal phase w(NaCleq) values of 0.42%~13.83% and 29.11%~42.48%, to late stage values 0.35%~5.86%. The trapping pressures estimated on the basis of CO2 inclusions are 93~199 MPa, 47~169 MPa for the early and main stage, and 28~64 MPa for the late stage estimated on the basis of W-type inclusions. The corresponding ore-forming depths are 3.4~7.2 km, 1.7~6.2 km and 2.9~6.5 km respectively, indicating that the mineralization occurred during the uplift of the earth's crust, and the regional stress field converted from compression to extension. Fluid boiling seems to have been the main mechanism of rapid precipitation of sulfides, gold and other minerals. The evolution of the ore-forming fluid system evolved from rich CO2 to poor CO2 due to the mixing of boiling and precipitation., and the fluid system evolved from the metamorphic fluid to the atmospheric precipitation.
文章编号：
中图分类号：P618.51
文献标志码：
基金项目:本研究得到了国家自然科学基金项目(41030423)、五矿勘查开发有限公司科技找矿项目和中央高校基本科研业务费专项资金(2652013017)联合资助
引用文本：
李新培,陈良,王琦崧,王文博,李雷,苏蔷薇.2016.河南嵩县七亩地沟金矿床成矿流体来源及演化——来自矿床地质和流体包裹体的证据[J].矿床地质,35(2):283~299LI XinPei,CHEN Liang,WANG QiSong,WANG WenBo,LI Lei,SU Qia.2016.Origin and evolution of ore-forming fluids of Qimudigou gold deposit in Songxian County, Henan Province: Evidence from ore geology and fluid inclusions[J].Mineral Deposits35(2):283~299
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