Late Cretaceous-Eocene granitic pegmatite rare-metal mineralization events in the western Yunnan Province:Constraints from U-Pb dating of columbite,monazite,and zircon
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.
Western YunnanLate-Cretaceous to EoceneGranitic pegmatiteRare metalMineralization timing
万方数据
维普
