【作者】 周起凤；

【导师】 李胜荣；

【作者基本信息】 中国地质大学（北京） ， 矿物学、岩石学、矿床学， 2010， 硕士

【摘要】 英格庄金矿位于胶东牟平-乳山金成矿带南部,产出于荆山群与昆嵛山杂岩体接触带内,为黄铁矿石英脉型金矿。该金矿主要包括4条矿脉,矿体受NNE向金牛山主断裂构造控制,平均金品位4.32×10-6。矿石类型以石英黄铁矿和多金属硫化物矿石为主。矿石矿物组成为黄铁矿等金属硫化物矿物、石英和碳酸盐矿物等。矿石结构以粒状结构和碎裂结构为主,矿石构造以块状构造、浸染状构造和脉状构造为主。金矿物包括银金矿和金银矿,以包裹金、粒间金和裂隙金为主要赋存形式。成矿作用划分为黄铁矿石英、石英黄铁矿、多金属硫化物和石英碳酸盐4个阶段。围岩蚀变类型包括钾长石化、钠长石化、绢云母化、绢英岩化、硅化、黄铁矿化、碳酸岩化和绿泥石化。本区黄铁矿晶形以五角十二面体及其与立方体以及八面体的聚形为主,由浅至深,由成矿早阶段至主成矿阶段,聚形晶发育且晶形变复杂,表明体系硫逸度升高,温度相对升高。主量元素分析结果为黄铁矿成分总体贫硫,黄铁矿以热液成因为主。微量元素分析揭示英格庄金矿成矿热液以岩浆热液为主,成矿早阶段有围岩老地层的参与作用。稀土元素地球化学分析结果为黄铁矿稀土配分模式为右倾型,主成矿阶段黄铁矿稀土元素配分模式基本一致。黄铁矿热电系数范围为-346.1~342.7μν/℃,热电导型多为P型与N型混合型,P型出现率平均为64%。南、北井黄铁矿P型出现率表明矿床南部相对抬升。P型和N型黄铁矿结晶温度均值分别为148.9℃和349.1℃。根据本区黄铁矿P型出现率与金品位的变化一致性,推测I号矿体由南向北P型出现率的凹陷区深部,II-1矿体和II-3矿体深部成矿前景良好。本区矿石矿物稳定同位素(He、Pb和S)分析结果显示成矿流体是以壳源为主的壳幔混合流体,成矿物质主要来源于下地壳和少量幔源物质,并有围岩荆山群地层的加入。石英H-O同位素分析表明成矿流体为岩浆水与大气水的混合流体。石英流体包裹体的分析测试表明英格庄金矿为中浅成中低温低盐度热液金矿,成矿流体总体属Na+(K+)-(Ca2+)-Cl-(SO42-)型,气相成分以气相水为主,其次为CO2、H2及少量CO、CH4和N2,主成矿阶段成矿流体为弱酸性,呈还原性质。更多还原

【Abstract】 The Yinggezhuang gold deposit which is a pyrite-quartz vein gold deposit is located in the south of Mouping-Rushan gold-deposit belt of Jiaodong Peninsular,occuring in the contact zone of the Jingshan group and the Kunyushan granitic complex body.The gold deposit is controlled by the Jinniushan fault which strikes in NNE,including 4 gold lodes whose average gold grade is 4.32×10-6.The ore types are mainly quartz-pyrite ores and polymetallic sulfide ores,composed of metal sulfide minerals,quartz and carbonate minerals.The textures of ores are dominated by granular texture and cataclastic texture.The structures of ores are predominant in massive structure , dense disseminated structure and vein structure.The gold minerals including kustelite and electrum occur in the form of enclosed gold,intergranular gold and fissure gold.The mineralization stages contain pyrite-quartz,quartz-pyrite,polymetallic sulfides and quartz-carbonate stages.The types of wall rock alteration include potassic alteration,albitization,sericitization,sericite-quartz alteration , silicification , pyritization , carbonatization and chloritization.The morphological characteristic of pyrite is mainly pentagonal dodecahedron and the combination form of pentagonal dodecahedron,cube and octahedral.The phenomenon that the combination form grows and the crystal shape becomes complicated during the major ore forming stage or in the deeper part shows the fugacity of sulfur and the temperature are increased in these conditions.The fact that the composition of pyrite is depleted in sulfur on the analysis of major element demonstrates that pyrite are magmatic origin.The analysis of trace element indicates that the ore forming fluid are maily magmatic hydrothermal and in the early metallogenic stage the country rocks work in the metallogeny.The analysis of REE reveals that the REE distribution pattern of pyrite is right deviation pattern and is unanimous in the samples of major metallogenic stage.The thermoelectric coefficient of pyrite ranges from -346.1μν/℃to 342.7μν/℃.The conduction type is mainly mixture of type P and type N and the average appearace rate of type P is 64%.The difference of the appearace of type P between the south and north mine shows that the south of gold deposit is higher uplifted.The crystallization temperatures of pyrite of type P and type N are 148.9℃and 349.1℃.On the basis of the accordance of gold grade and the occurrence of type P good ore forming prospects of the concave field of the occurrence of type P mapping and the deep part of II-1 and II-3 ore bodies are presumed.The analysis of stable isotopes of ore mineral(sHe,Pb and S)suggest that the ore forming fluid is the mixture of crust origin and mantle origin fluid,mainly of crust,and the metallogenic materials are originated from the lower crust with a little mantle material and the Jingshan group.The hydrogen-oxygen isotope analysis of quartz demonstrates that the ore forming fluid is a mixture of magma fluid and meteoric water.The measurements and analysis of quartz fluid inclusions show that the gold deposit is a hydrothermal gold deposit formed in mid-shallow,mid-low temperature,low salinity condition.The ore forming fluid is the type of Na+(K+)-(Ca2+)-Cl-(SO42-)on the basis of the liquid phase composition of quartz fluid inclusion and the gas phase composition of quartz fluid inclusion is minaly H2O,as well as CO2,H2,CO,CH4 and N2.On the calculation of the liquid and gas phase composition of quartz fluid inclusion the ore forming fluid of the main ore forming stage is in weak acid and reduction conditions.更多还原