拉尔玛金成矿带成矿流体氢氧同位素组成及其演化  

THE COMPONENTS AND EVOLUTION OF THE HYDROGEN AND OXYGEN ISOTOPES OF ORE-FORMING FLUIDS FORM LA’ERMA GOLD ORE BELT

作　　者：刘家军[1,2,3] 郑明华[1,2,3] 周德安 刘建明[4,2] 周渝峰[4,2] 顾雪祥 张斌[4,2] 林丽 

机构地区：[1]中国科学院地球化学研究所 [2]成都理工学院 [3]核工业部北京地质研究院 [4]中国科学院矿物资源探查研究中心

出　　处：《长春科技大学学报》1998年第1期43-49,共7页Journal of Changchun University of Science and Technology

基　　金：国家自然科学基金;中国-奥地利国际合作资助;国家自然科学基金;中国博士后科学基金

摘　　要：西秦岭南亚带的拉尔玛金成矿带，由拉尔玛、邛莫金矿床和牙相金矿点组成。矿床（点）赋存于寒武系太阳顶群碳质硅岩和碳质板岩组成的硅岩建造中，受地层、岩性、岩相和构造控制十分明显，对其所表现出来的层控性质为众所公认。通过对各金矿床（点）流体氢、氧同位素组成研究之后，作者得出成矿流体乃大气降水的结论。大气降水补给的地下热液在环流过程中，促使硅岩建造中的成矿物质发生活化、迁移和再聚集，并最终导致工业矿床的形成。水－岩体系氢、氧同位素交换演化曲线表明，矿质沉淀时，成矿流体曾发生过沸腾作用。The La′erma gold ore belt, in the south subzone of western Qinling,include La′erma and Qiongmo ore deposits and Yaxiang ore occurrence.These stratabound gold deposits are closely associated with submarine exhalative sedimentation and possess many unique features. The gold deposits in the Cambrian silicalite formation composed of black chert and slate are so clearly confined by strata, host rock types and structures that their stratabound character is well accepted. The hydrothermal minerals such as quartz and barite in the gold ore belt have their δ 18 O values -3.19‰～+26.71‰, leading to ore-forming fluids with δ 18 O of -11.06‰ ～+15.34‰ (from isotope fractionation equations of quartz-water and barite-water), δD of -58.2‰￣-121.5‰ (from fluid inclusions). It is show through the above-described isotopic study that the oreforming solution was mainly derived from the ancient meteoric water. Oxygen and hydrogen isotopic evolution curves for water and rock system indicated that metallogenic fluids would have boiled while ore-forming materials precipitated. During the hydrothermal minerlization from, circulating groundwater (meteoric water), ore-forming materials in the silicalite formation were remobilized, migrated and re enriched, which contributed to the formation of the present ore bodies.

关 键 词：金矿床 成矿带 成矿流体 氢 氧 同位素 

分 类 号：P618.510.4[天文地球—矿床学] P618.510.5[天文地球—地质学]