江西盘古山石英脉型钨矿床流体包裹体研究  

Fluid inclusion studies of the Pangushan quartz-vein type tungsten deposit in southern Jiangxi Province

作　　者：王旭东[1] 倪培[1] 张伯声[1] 王天刚[1] 

机构地区：[1]南京大学内生金属矿床成矿机制研究国家重点实验室,地质流体研究所,地球科学与工程学院,江苏南京210093

出　　处：《岩石矿物学杂志》2010年第5期539-550,共12页Acta Petrologica et Mineralogica

基　　金：国家自然科学创新群体基金资助项目(40221301);内生金属成矿作用研究国家重点实验室项目

摘　　要：采用"流体包裹体组合"(FIA)的方法,在详细的岩相学观察的基础上,对盘古山钨矿床主要矿化阶段中早阶段的辉铋矿-黑钨矿-石英脉和晚阶段的(辉铋矿)-黑钨矿-石英脉石英中的流体包裹体进行了显微测温和拉曼探针的分析。该矿床主要矿化阶段含矿石英脉中包裹体主要包括H2O-NaCl型包裹体、H2O-NaCl-CO2型包裹体和少量的CO2型包裹体,富含CO2组分是盘古山钨矿成矿流体的明显特征。实验结果表明,矿床中主要矿化阶段石英脉中两相的H2O-NaCl型包裹体与H2O-NaCl-CO2型包裹体主要均一温度范围较为一致而前者盐度相对较高。辉铋矿-黑钨矿-石英脉中的H2O-NaCl型包裹体的均一温度明显高于(辉铋矿)-黑钨矿-石英脉中的H2O-NaCl型包裹体,但两者的盐度相差不大,从辉铋矿-黑钨矿-石英脉到(辉铋矿)-黑钨矿-石英脉,H2O-NaCl-CO2型包裹体数量减少,CO2型包裹体数量增多。对各类包裹体的激光拉曼探针测试表明,辉铋矿-黑钨矿-石英脉中和(辉铋矿)-黑钨矿-石英脉中的包裹体的组分相近,除水和CO2外,还含有少量的CH4和N2。盘古山钨矿的流体包裹体特征表明,以CO2逸失为特征的流体不混溶作用是矿床金属沉淀的主要机制。The Pangushan tungsten deposit is an important large-size quartz-vein type W-polymetallic deposit in southern Jiangxi Province.Based on detailed petrographic observations and using the means of Fluid Inclusion Assemblage （FIA）,the authors carried out microthermometric and Raman microspectroscopic studies of fluid inclusions in early bismuthinite-wolframite-quartz veins and late （bismuthinite）-wolframite-quartz veins of the main ore-forming stage of the Pangushan tungsten deposit.The fluid inclusions are mainly of H2O-NaCl type and H2O-NaCl-CO2 type together with minor pure CO2 type.The existence of abundant CO2-rich inclusions is a typical feature of the Pangushan Tungsten deposit.Experimental results show that the main homogenization temperature range of the two-phase H2O-NaCl type fluid inclusions is comparable to that of the H2O-NaCl-CO2 type inclusions,while the salinity of the two-phase H2O-NaCl type is higher than that of the H2O-NaCl-CO2 type.In addition,the H2O-NaCl type fluid inclusions show evident decrease in homogenization temperature from the early veins to the late veins at constant salinity.Moreover,less H2O-NaCl-CO2 type inclusions occur in the （bismuthinite）-wolframite-quartz veins while relatively abundant CO2 type inclusions are existent.Raman microspectroscopic studies of various types of inclusions show that,besides water and CO2,the fluid inclusions also contain small amounts of CH4 and N2.The characteristics of fluid inclusions in the Pangushan Tungsten deposit indicate that the fluid immiscibility caused by CO2 escaping possibly led to tungsten precipitation.

关 键 词：CO2包裹体 流体不混溶 石英脉型钨矿 盘古山 赣南 

分 类 号：P618.67[天文地球—矿床学] P59[天文地球—地质学]