滇西晚白垩世-始新世花岗伟晶岩型稀有金属成矿事件:来自铌钽铁矿、独居石、锆石U-Pb年代学的约束  

Late Cretaceous-Eocene granitic pegmatite rare-metal mineralization events in the western Yunnan Province:Constraints from U-Pb dating of columbite,monazite,and zircon

作　　者：何小虎 游亚元 明添学 杨斯琦 闫庆贺 陈会 刘梦帆 HE XiaoHu;YOU YaYuan;MING TianXue;YANG SiQi;YAN QingHe;CHEN Hui;LIU MengFan(School of Earth Sciences,Yunnan University,Kunming 650500,China;Yunnan International Joint Laboratory of Critical Mineral Resource,Kunming 650500,China;Institute of Yunnan Geology Survey(Institute of Yunnan Geological Sciences),Kunming 650051,China;Faculty of Materials Science and Engineering,Kunming University of Science and Technology,Kunming 650093,China)

机构地区：[1]云南大学地球科学学院,昆明650500 [2]云南省关键矿产资源国际联合实验室,昆明650500 [3]云南省地质调查院(地质科学研究院),昆明650051 [4]昆明理工大学材料科学与工程学院,昆明650093

出　　处：《岩石学报》2024年第2期510-538,共29页Acta Petrologica Sinica

基　　金：云南省地质勘查基金管理中心新一轮找矿行动科研项目(Y202305);云南省兴滇英才计划项目(C6213001155)联合资助。

摘　　要：滇西地区位于东特提斯构造域东段,经历了特提斯构造域复杂的地质演化过程,导致该地区发育大量与稀有金属成矿相关的花岗伟晶岩脉,具有极好的花岗伟晶岩型稀有金属成矿地质条件。区域地质调查评价和地球化学填图显示滇西地区具备形成锂、铍、铌、钽等稀有金属矿产资源的良好潜力。本文以滇西地区黄连沟、黄草坝、那俄、杞木寨、麻栗脑、禾波、黑妈等含稀有金属矿化的花岗伟晶岩为研究对象,通过铌钽铁矿、独居石、锆石等LA-ICP-MS U-Pb定年手段,对这些花岗伟晶岩型稀有金属矿床/点开展成矿/成岩年代学研究。结果显示滇西花岗伟晶岩型稀有金属矿床主要形成于晚白垩世-始新世(ca.70~40Ma),与中国其他地区花岗伟晶岩型稀有金属矿床主要形成于早古生代和中生代时期有显著的差异。本文年龄结果表明滇西地区存在多阶段花岗伟晶岩型稀有金属成矿事件,可能与区域新特提斯构造-岩浆活动关系密切。这些年龄为探讨滇西花岗伟晶岩型稀有金属成矿规律,有效指导区域找矿勘探部署和建立该地区伟晶岩型稀有金属矿床成矿模型奠定了理论基础。The western Yunnan is located in the eastern part of the east-Tethys tectonic domain,and has experienced complex geological evolution processes,resulting in the development of numerous granitic pegmatite veins related to rare-metal mineralization in this area,which has excellent geological conditions for granitic pegmatite-type rare-metal mineralization.Regional geological survey and evaluation and geochemical mapping suggest that the western Yunnan has great potential for rare-metal(e.g.,lithium,beryllium,niobium,tantalum)mineralization.This study focuses on granitic pegmatites with rare-metal mineralization in the western Yunnan,including Huangliangou,Huangcaoba,Na'e,Qimuzhai,Malinao,Hebo,and Heima.We use columbite,monazite,and zircon LA-ICP-MS U-Pb dating methods to constrain their mineralization/diagenetic chronology.The results show that the granitic pegmatite rare-metal deposits in the western Yunnan were mainly formed during the Late Cretaceous-Eocene(ca.70~40Ma)periods,which is significantly different from that of granitic pegmatite rare-metal deposits mainly formed at the Early Paleozoic and Mesozoic periods in other regions of China.The age results in this study indicate that there are multi-stage granitic pegmatite rare-metal mineralization events,which may be closely related to Neo-Tethys tectono-magmatic activities in the western Yunnan.These ages have supplied a theoretical foundation for exploring the mineralization regularity,effectively guiding regional exploration,and establishing the model for granitic pegmatite rare-metal mineralization in this region.

关 键 词：滇西 晚白垩世-始新世 花岗伟晶岩 稀有金属 成矿时代 

分 类 号：P588.131[天文地球—岩石学] P597.3[天文地球—地质学] P618.6