摘要
茶山锑钨矿床是广西南丹大厂锡多金属矿田的重要组成部分。萤石是该矿床最主要的脉石矿物之一,其形成与锑、钨矿化密切相关。本文系统研究了该矿床中萤石的微量元素（含稀土元素）地球化学特征。结果表明,该矿床萤石样品稀土元素含量变化范围为4.03×10-6~77.53×10-6,平均38.72×10-6;其球粒陨石标准化模式总体为平坦型,轻重稀土分馏不显著,并具有弱负铈异常（δCe=0.76~0.87）和较强的正铕异常（δEu=1.48~2.94）特征。明显不同于大厂锡多金属矿田内的不同类型矿石、围岩及岩浆岩的稀土元素特征（LREE富集型,且具明显的负铕异常）。此外,相对于陆壳和桂北地区泥盆系地层元素丰度,萤石中仅Sb、W等元素有不同程度的富集;而Cu、Zn、Co、Ni等元素出现了亏损。综合分析和对比研究认为,茶山矿床与锑钨矿化有关的成矿流体并非来源于泥盆纪赋矿围岩,可能是经历了深部循环的外来流体。
The Chashan Sb-W deposit is located in Dachang Sn-polymetallic ore field,Nandan,Guangxi.Fluorite is one of major gangue minerals in this deposit,which is closely related with antimony and tungsten mineralization.Geochemical study on trace elements（including rare earth elements,REE）of fluorite was carried out systematically in this paper.The results show that the total REE concentrations of fluorite range from 4.03×10-6 to 77.53×10-6,with an average of 38.72×10-6.The chondritenormalized REE distribution pattern is flat,with slight fractionation between LREE and HREE,and slightly Ce negative anomaly（δCe=0.76~0.87）and relatively strong Eu positive anomaly（δEu=1.48~2.94）.These features are clearly different from the characteristics of REE（LREE-rich pattern,with obvious negative Eu anomaly）for different types of ores,host rocks and magmatic rocks from Dachang Snpolymetallic ore field.Furthermore,compared with other elemental abundance of the continental crust and Devonian strata in the western Guangxi,the fluorite from Chashan deposit is riched in Sb and W,and depleted in Cu,Zn,Co,Ni,etc.By comprehensive analysis and comparison the ore-forming fluid closed associated with Sb-W mineralization of Chashan deposit would not be sourced from the Devonian host rocks,may be derived dominantly from deep-circled fluids.
出处
《地质学报》
EI
CAS
CSCD
北大核心
2015年第2期384-391,共8页
Acta Geologica Sinica
基金
国家重点基础研究发展计划973课题(编号:2014CB440904)
国家自然科学基金项目(编号:41272113和40972072)
矿床地球化学国家重点实验室"十二五"项目群(编号:SKLODG-ZY125-01)资助的成果
关键词
萤石
微量元素
稀土元素
成矿流体
茶山锑钨矿床
广西大厂锡多金属矿田
fluorite
trace element
rare earth element
ore-forming fluid
Chashan Sb-W deposit
Dachang Sn-polymetallic ore field in Guangxi
