地质学报2017，Vol.91Issue(4)：876-895,20.
赣南盘古山和淘锡坑黑钨矿化学成分和晶体结构及指示意义
Chemical Composition and Crystal Texture of the Pangushan and Taoxikeng Wolframite in Southern Jiangxi and its Indication Significance
摘要
Abstract
Southern Jiangxi province is famous for its tungsten mineral resources in the world,of which wolframite is the most important tungsten ore in the area.Wolframite from two typical tungsten deposits at Panguushan and Taoxikeng in southern Jiangxi was studied in this paper,the crystal structure and chemical composition of wolframite are analyzed to understand its spatial distribution using electron probe and X-ray diffraction.Results indicate that the wolframite in the research area belongs to manganese tungsten ore,and the Mn2+ and Fe2+ in the wolframite is a kind of isomorphic relationship,and MnO and FeO shows an obviously negative correlation.The value of x[Fe / (Mn + Fe)] has certain regularity in the space.From deep to shallow of the vein,x value first increases and then decreases,which reflects the migration of ore fluid from bottom to top,and backflow may occur in the shallow.The x[Fe / (Mn +Fe)] values in the middle section of the vein are higher than those on both side of the same vein,indicating that the formation temperature of wolframite in the middle section of the vein is higher than that on both sides of the vein.The contents of Nb and Ta of wolframite in Pangushan are higher than those in Taoxikeng,indicating that the Pangushan wolframite is closer to the rock mass than the Taoxikeng wolframite.From bottom to top of a single vein,the contents of Nb and Ta in the wolframite firstly decrease rapidly and then increase slightly,which indicates the complexity of the ore-bearing fluid migration.The chondrite-standardized REEs distribution diagrams of wolframite from Pangushan tungsten and Taoxikeng ore deposits are characterized by left-leaning pattern with relative enrichment of heavy REEs.Wolframite from the Pangeoushan tungsten ore deposit is characterized by relatively high ∑REEs,low LaN/YbN,and obvious REEs fractionation.Wolframite from the Taoxikeng tungsten ore deposit is characterized by relatively low content of ∑REEs and a wide range of of LaN/YbN,and variable REEs fractionation.They all have a strong negative δEu anomaly and weak negativeδCe anomaly,indicating that the deposits were formed in the closed reduction conditions.The comparison study of cell parameters of wolframite from five typical tungsten deposits,including Pangushan,Taoxikeng,Sanhu,Hukeng,Yaogangxian tungsten ore deposits,shows that wolframite occurring within inner contact zone of granite has a low FeO content and high cell parameters,while wolframite in outer contact zone of granite has a high FeO content and low cell parameters.Therefore,the chemical composition and crystal structure characteristics of wolframite can not only be used to indicate the migration features of ore-forming materials in the space,but also discriminate the genesis of ore deposits.The results of the study have reference and enlightenment significance to the similar deposits.关键词
黑钨矿/化学成分/晶体结构/空间分布规律/盘古山/淘锡坑/赣南Key words
Wolframite/chemical composition/crystal texture/spatial distribution regularities/Pangushan/Taoxikeng/South Jiangxi引用本文复制引用
谢星,梁婷,鲁麟,赵正趵,陈郑辉,陈伟,丁明..赣南盘古山和淘锡坑黑钨矿化学成分和晶体结构及指示意义[J].地质学报,2017,91(4):876-895,20.基金项目
本文为国土资源部公益性行业科研专项(201411050)、国家重点研发计划课题(2016YFC0600208)、国家自然科学基金重点资助计划(41430314)、中国矿产地质与区域成矿规律综合研究(中国矿产地质志)(编号:1212011220369)资助的成果. （201411050）
