摘要
马头山铜金矿床位于康定—锦屏山矿集区,处于锦屏山断裂与康定—水城断裂的交汇部位,是川西南地区新发现的中型铜金矿床。矿体呈现为硫化物石英脉状,赋存于泥盆系泥质粉砂质板岩、碳酸盐化泥晶灰岩和二叠系变质玄武岩中,受断裂构造控制,矿石中硫化物矿物多见黄铁矿、斑铜矿、黄铜矿、方铅矿等。矿石中石英原生流体包裹体观测和激光拉曼光谱分析显示,马头山铜金成矿流体为H2O−CO2−NaCl体系,均一温度108.1~439.1℃,盐度3.55%~22.78%NaCleq,密度0.51~1.12 g/cm^3,主成矿阶段流体包裹体具有中低温、中低盐度、低密度、富含CO2的特征。矿石中硫化物矿物δ^34SV−CDT=−4.6‰~8.4‰,具有岩浆来源硫的特征,石英脉中原生流体包裹体的δD=−78.8‰~−48.7‰,δ^18O H2O=−2.1‰~9.3‰,白云石的δ^13CV−PDB=−5.3‰~1.7‰,δ^18OV−SMOW=19.4‰~25.9‰,表明成矿流体主要为岩浆水,并有地层流体和大气水加入。综合矿床地质特征、流体包裹体特征和S、C、O、H同位素证据,认为马头山铜金矿床为中低温−岩浆热液型铜金矿床。
The Matoushan copper-gold deposit is located in the Kangding−Jinping mountain metallogenic concentration area.It is located in the junction of the Jinping−kangding−Shuicheng fault.It is a one of medium−size copper gold deposit in Southwest Sichuan Province.Ore bodies was presented as sulfide quartz vein,which occur in Devonian carbonated mudstone limestone and Permian metamorphic basalt.They are obviously controlled by structures.Pyrite,bornite,chalcopyrite and galena are common sulfide minerals in the ore.The observation of primary fluid inclusions of quartz in the ore and Laser Raman spectroscopy analysis show that,the ore-forming fluid of Matoushan Cu−Au deposit is a system of H2O−CO2−NaCl,the average temperature of fluid inclusions ranged from 108.1 to 439.1℃,and the salinity ranged from 3.55% to 22.78% NaCleq with a density ranged of 0.51 to 1.12 g/cm3,the fluid inclusions at the major metallogenic stage has the characteristics of medium temperature,medium-low salinity,low density,and rich in CO2.Theδ^34SV−CDT was−4.6‰ to 8.4‰ of sulfide minerals in ores,indicating that the characteristics of S isotopic are from the magmatic;the primary fluid inclusions in quartz veins areδD=−78.8‰−−48.7‰ and δ^18O H2O=−2.1‰−9.3‰,the carbon and oxygen isotopic compositions of the dolomite areδ^13CV−PDB=−5.3‰−1.7‰ and δ^18OV−SMOW=19.4‰−25.9‰,which indicates that the ore−forming fluid is magmatic water-mixed with meteoric water and formation fluid.Based on the geological features of ore deposit,fluid inclusions and the isotopic evidence of S,C,O and H,it can ben concluded that the Matoushan coppergold deposit belongs to the type of medium-low temperature−magmatic hydrothermal Cu−Au deposit.
作者
辛存林
徐明儒
安国堡
胡菊英
杨涛
董凯
XIN Cunlin;XU Mingru;AN Guobao;HU Juying;YANG Tao;DONG Kai(College of Geography and Environmental Science,Northwest Normal University,Lanzhou 730070,Gansu,China;No.282 Geological Party,Sichuan Bureau of Geology for Nuclear Industry,Deyang 618000,Sichuan,China;Faculty of Geomatics,Lanzhou Jiaotong University,Lanzhou 730071,Gansu,China;College of Geography and Resources,China University of Geosciences,Wuhan 430074,Hubei,China)
出处
《中国地质》
CAS
CSCD
北大核心
2019年第6期1556-1572,共17页
Geology in China
基金
中国地质调查局区域地质调查项目(K15-1-LQ17)
国家自然科学基金项目(41262001)联合资助~~
关键词
流体包裹体
稳定同位素
热液
马头山
Cu-Au矿床
冕宁
地质调查工程
fluid inclusions
stable isotopes
hydrothermal liquid
Matoushan
Cu−Au deposit
Mianning
geological survey engineering
