内蒙古甲乌拉银多金属矿床成矿流体演化与成矿机制分析  

ORE-FORMING FLUIDS EVOLUTION AND METALLOGENIC MECHAMISM ANALYSIS OF THE JIAWULA Ag-POLTMETALLIC DEPOSIT,INNER MONGOLIA

作　　者：翟德高[1,2] 王建平[1,2] 刘家军[1,2] 吴胜华[1,2] 毛光剑[1,2] 王守光[3] 李玉玺[3] 

机构地区：[1]中国地质大学地质过程与矿产资源国家重点实验室,北京100083 [2]中国地质大学岩石圈构造,深部过程及探测技术教育部重点实验室,北京100083 [3]内蒙古自治区地质调查院,内蒙古呼和浩特010020

出　　处：《矿物岩石》2010年第2期68-76,共9页Mineralogy and Petrology

基　　金：国家重点基础研究发展规划(2006CB403500);内蒙古自治区政府地质勘查项目;教育部长江学者和创新团队计划;高等学校科技创新引智计划(B07011);中国地质大学(北京)大学生创新性实验计划项目

摘　　要：内蒙古甲乌拉大型银多金属矿床位于我国北方重要的银多金属矿集区,该矿床属于大兴安岭满洲里-新巴尔虎右旗银多金属成矿带。为探讨其成矿流体演化和成矿机制,对矿床的石英流体包裹体进行深入研究。包裹体显微测温结果表明均一温度集中在180℃~260℃,结合流体包裹体热力学公式计算得到:流体盐度范围为0.18%~12.62%,流体密度为0.637 g/cm3~0.976 g/cm3,流体压力的变化范围是0.344 MPa^16.205 MPa,成矿深度约为0.5 km^1.5 km。激光拉曼测试结果表明成矿流体属于H2O-NaCl体系。甲乌拉银多金属矿床成矿流体的总体特征表现为中低温度、中低压力、中低盐度、低密度的流体。矿床成矿流体有两种来源:其一可能为岩浆源为主导的流体;其二可能为大气降水为主导的流体。成矿流体在演化过程中发生流体的混合作用。不同性质、成分流体的混合作用是导致成矿元素发生聚集、沉淀形成矿床的重要机制。The Jiawula Ag-polymetallic deposit in the northern Ag-polymetallic ore concentration area in China belongs to the Manchuria-Xiqi Ag-polymetallic metallogenic belt in Da Hinggan Mountain.Studies of fluids evolution and metallogenic mechanism of the ore deposit are carried out in the paper.Microthermometric study of the fluid inclusions indicates that homogenization temperature ranges from 180 ℃ to 260 ℃.Salinities,densities,pressure and depth of ore forming fluids of the deposit are 0.18%～12.62% NaCl eqv,0.637 g/cm3~0.976 g/cm3,0.344 MPa^16.205 MPa and 0.5 km^1.5 km,respectively.Test results of the laser Raman study show that the ore forming fluids belong to the H2O-NaCl system.All data demonstrate that the ore forming fluids of the Jiawula deposit are characterized by medium-low temperature,medium-low pressure,medium-low salinity,low density fluids.The composition of the fluids can be divided into two end members：one member is possibly dominated by magmatic fluids while the other is by meteoric water.With high content of metallogenic elements,the magmatic fluids mixed with the rebuilt-meteoric fluids.Fluid mixing is the key factors controlling the accumulation and precipitation of metallogenic elements and the formation of ore deposit.

关 键 词：银多金属矿床 流体包裹体 流体混合 激光拉曼 甲乌拉 内蒙古 

分 类 号：P618.52[天文地球—矿床学]