摘要
滇西位于青藏高原的东南部,其地质构造演化过程是特提斯构造、岩浆和成矿演化的缩影。该地区稀有金属资源成矿潜力是近年来地质学家关注的热点问题。在前人研究的基础上,本文收集、分析和整理已有的地质勘查资料及年代学、地球化学和同位素数据,并通过对典型稀有金属矿床(点)的考察和研究,结合“第二次青藏高原科学考察综合研究”专题“稀有金属资源现状和远景评估”执行过程中的最新研究成果,阐述了滇西地区稀有金属矿床的成矿类型、时空分布、成矿规律和资源远景。滇西地区稀有金属矿床主要沿怒江和澜沧江断裂带呈带状、局部集中分布;成矿类型主要有花岗岩型、伟晶岩型、矽卡岩型、云英岩型、电气石-石英脉型、硫化物-石英脉型、金云母热液脉型、风化壳型以及煤系型和热泉型等,其中花岗岩型和伟晶岩型稀有金属矿床中发育有宝玉石资源(如:碧玺和海蓝宝石等)。滇西稀有金属矿床主要形成于三叠纪(240~220Ma)、早白垩世(124~120Ma)、晚白垩世(80~70Ma)、古新世-始新世(65~50Ma)、渐新世(33~30Ma)、中新世(25~12Ma)等6个时期,分别与三叠纪古特提斯洋闭合后碰撞环境、新特提斯洋的俯冲,以及印度-欧亚大陆碰撞及碰撞后的大型剪切走滑作用有关。滇西Li-Be-Rb-Cs稀有金属矿床主要形成于晚白垩世、古新世-始新世和中新世,其中渐新世和中新世主要与剪切走滑变形变质作用密切相关。滇西地区稀有金属矿床具有富F或富B,或富F且富B的特点,与不同时期分异程度较高的花岗岩关系密切。锡石、电气石和云母等指示矿物可以示踪稀有金属成矿过程及成矿元素组合的差异性。本文提出滇西稀有金属成矿具有地域性和时域性的特点,晚白垩世和中新世是该地区稀有金属大规模成矿时期,稀有金属资源成矿潜力较好,其中花岗岩型和伟晶岩型是下一步主要突破方向。Li-Rb-Cs的找矿工作多集中怒江成矿带,腾冲-梁河地区以花岗岩型和风化壳型为主,高黎贡地区应以伟晶岩型和金云母热液脉型为主。Be矿找矿工作应集中于高黎贡和腾冲-梁河地区,崇山和西盟地区也应予以关注。Nb-Ta和Zr-Hf找矿应多注重寻找与主矿种共伴生元素的Nb-Ta和Zr-Hf。锡矿则应以寻找稀有金属花岗岩型为突破口,以及在已有矿床的深部和外围开展工作。
The western Yunnan region is located in the southeastern part of the Tibetan Plateau,and its geological evolution in history is a microcosm of the Tethys tectonic belt.A large-scale Cu,Pb,Zn and other non-ferrous metal deposits occur in western Yunnan.However,the potential of rare metal mineralization has been a scientific issue to geologists in the past decades.In the process of carrying out the project“Assessment of the Current Status and Prospects of Rare Metal Resources”of“Comprehensive Study of the Second Scientific Expedition of Tibetan Plateau”,the paper collected,analyzed,and organized existing geological exploration data,geochronological data,geochemical and isotopic data based on previous research.Through the investigation and research of typical rare metal deposits(occurrences),it reveals the metallogenic and resource prospects of rare metals in western Yunnan.Rare metal deposits in western Yunnan are mainly distributed in banded and locally concentrated along the Nujiang River Fault and Lancang River Fault.The rare metal mineralization mainly includes granite,pegmatite,skarn,greisen,tourmaline-quartz vein,sulfide-quartz vein,phlogopite vein,weathering,as well as coal-host and hot-spring-host type.Some granite and pegmatite rare metal deposits host precious jade resources(such as tourmaline,aquamarine,etc.).These rare metal deposits were mainly formed in six periods:Triassic(240~220Ma),Early Cretaceous(124~120Ma),Late Cretaceous(80~70Ma),Paleocene-Eocene(65~50Ma),Oligocene(33~30Ma),and Miocene(25~12Ma).They are related to the collision environment after the closure of the Paleo-Tethys Ocean in the Triassic,the subduction and collision of the New-Tethys Ocean,and the large-scale shear strike slip after the collision between India and Eurasia,respectively.Li-Be-Rb-Cs rare metal deposits were mainly formed in the Eocene-Oligocene and Miocene,which related to contemporaneous shear strike-slip deformation-metamorphism.It shows that rare metal mineralization in western Yunnan,has the characteristic of regional and temporal controlling,and the characteristics of being rich in F or B,or rich in F and rich in B,and are closely related to granites with high differentiation in different periods.Indicator minerals such as cassiterite,tourmaline,and mica can trace the mineralization process of rare metals and the differences in the composition of ore-forming elements.This paper suggests that it has good potential for rare metal mineralization in western Yunnan,the granite and pegmatite rare-metal deposits as the main resources for next exploration.In the future,the exploration of Li-Rb-Cs will mainly focus on the Nujiang metallogenic belt,with granite-type rare metal deposit and weathering-type rare metal deposits in the Tengchong-Lianghe area,pegmatite and hydrothermal vein being the main resource in the Gaoligong area.The exploration target for Be mineralization mainly focuses on the Gaoligong area and Tengchong-Lianghe area,Chongshan and Ximeng regions should also pay more attention.The exploration of Nb-Ta and Zr-Hf should pay much for their associated main mineralization species.Tin mineralization should be considered more in depth and peripheral in the current exploration project.
作者
李晓峰
徐恒
朱艺婷
余勇
邓宣驰
崔子良
王泽传
姜永果
吴福元
LI XiaoFeng;XU Heng;ZHU YiTing;YU Yong;DENG XuanChi;CUI ZiLiang;WANG ZeChuan;JIANG YongGuoand WU FuYuan(State Key Laboratory of Lithospheric and Environmental Coevolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;No.306 Geological Party,Yunnan Nonferrous Geological Bureau,Kunming 650217,China;College of Earth Sciences,Guilin University of Technology,Guilin 541004,China;Yunnan Institute of Geology and Mineral Resources Exploration,Kunming 650051,China)
出处
《岩石学报》
北大核心
2025年第7期2213-2242,共30页
Acta Petrologica Sinica
基金
第二次青藏高原综合科学考察研究(2019QZKK0802)
中国科学院地质与地球物理研究所重点部署项目(IGGCAS-202205)联合资助.
关键词
稀有金属矿床
成矿规律
成矿远景
时空分布
变质变形
滇西
青藏高原
Rare metal deposits
Metallogeny
Ore-forming prospect
Temporal and spatial distribution
Tectonic setting
Western Yunnan
