花岗岩Sn-W-Nb-Ta-Rb-Cs-Li成矿作用的研究方法——以滇西南大同山稀土矿区土壤化探异常查证为例  

Research methods of Sn-W-Nb-Ta-Rb-Cs-Li mineralization in granites:A case study of soil geochemical exploration anomalies verification in Datong Mountain rare earth mining area in southwest Yunnan Province

作　　者：顾光明 李杭 严城民[2] 周家喜[3] 马重辉 罗伟 周坤 高爱奎 雷星 GU Guangming;LI Hang;YAN Chengmin;ZHOU Jiaxi;MA Chonghui;LUO Wei;ZHOU Kun;GAO Aikui;LEI Xing(Yunnan Nuclear Industry Geological Survey Institute,Kunming 650106,Yunnan,China;Provincial Natural Resources Department Geological Exploration Fund Management Center,Yuxi 653100,Yunnan,China;School of Resources,Environment and Earth Sciences,Yunnan University,Kunming 650500,Yunnan,China)

机构地区：[1]云南省核工业地质调查院,云南昆明650106 [2]云南省地矿局区域地质矿产调查大队,云南玉溪653100 [3]云南大学资源环境与地球科学学院,云南昆明650500

出　　处：《矿产勘查》2024年第7期1204-1214,共11页Mineral Exploration

基　　金：云南省地质勘查基金项目(K202102)资助。

摘　　要：滇西南大同山稀土矿区位于临沧花岗岩中南段,基岩主要为三叠纪黑云母二长花岗岩,属“S”型花岗岩,形成于同碰撞环境。临沧花岗岩分布区为Sn、W、Bi、B、Li、Rb、Cs、Pb、As、Sb高丰度区,在矿区内La-Y-Nb组合异常,但未进行检查。在矿区1∶50 000土壤地球化学调查中,圈定了16个综合异常。异常查证中,在13个综合异常区的半风化—微风化花岗岩中共采集19件化学分析样,分析了与综合异常相关的7种元素(Sn、W、Nb、Ta、Rb、Cs、Li)。本研究中总结了4种方法:(1)经岩石类型分析数值比较,除中粗粒黑云母二长花岗岩(ηγ^(c)T)与Cs_(2)O矿化有较密切关系外,其他岩石类型与矿化无明显关系;(2)通过样品分析数值比较,将样品划分为矿化元素、矿化程度不同的4种类型;(3)通过矿化系数分析,矿区可能存在Sn-W矿化、Rb-Cs矿化;(4)通过成矿系数分析,矿种的平均成矿系数由大至小为Rb_(2)O(0.6929)→Nb_(2)O_(5)(0.1445)→Cs_(2)O(0.0626)→Ta_(2)O_(5)(0.0378)→WO_(3 )(0.0195)→Sn(0.0101)→Li_(2)O(0.0098)。这4种研究方法对研究临沧花岗岩的成矿作用、进行成矿预测有较为重要的指导作用。在地质背景相似的地区寻找相似矿种,也可借鉴本文提出的研究方法。The Datongshan REE deposit area in southwest Yunnan is located in the middle and south section of Lincang granite.The bedrock is mainly Triassic Biotite monzonite granite,which belongs to"S"type granite and was formed in syncollision environment.The distribution area of Lincang granite is Sn,W,Bi,B,Li,Rb,Cs,Pb,As,Sb high abundance area.La-Y-Nb combination is abnormal in the mining area,but no inspection has been carried out.In the 1∶50000 soil geochemical survey of the mine area,16 comprehensive anomalies were delineated.In the process of anomaly verification,a total of 19 chemical analysis samples were collected from the semi-weathered and breezy granites in 13 comprehensive anomaly areas,and 7 elements (Sn,W,Nb,Ta,Rb,Cs,Li) related to the comprehensive anomaly were analyzed.In this study,four methods are summarized:(1) According to the numerical comparison of rock types,there is no obvious relationship between Cs_(2O) mineralization and other rock types,except for the medium coarse-grained biotite monzonitic granite (ηγc T).(2) The samples were divided into 4 types of mineralized elements and mineralization degrees through numerical comparison of sample analysis;(3) According to the mineralization coefficient analysis,Sn-W mineralization and Rb-Cs mineralization may exist in the mining area;(4) According to the analysis of metallogenic coefficient,the average metallogenic coefficient of the ores is Rb_(2O) (0.6929)→Nb_2O_(5) (0.1445)→Cs_(2O) (0.0626)→Ta_2O_(5) (0.0378)→WO_(3) (0.0195)→Sn (0.0101)→Li_(2O) (0.0098) from large to small.These four research methods have an important guiding role in the study of mineralization and metallogenic prediction of Lincang granite,and can also provide reference for the search for similar mineral species in areas with similar geological background.

关 键 词：花岗岩 Sn-W-Nb-Ta-Rb-Cs-Li 分析数值比较 矿化系数分析 成矿系数分析 大同山稀土矿床 

分 类 号：P595[天文地球—地球化学]