喜马拉雅淡色花岗岩带伟晶岩的富铍成矿特点及向更高处找锂  

Be-rich mineralization features of Himalayan leucogranite belt and prospects for lithium-bearing pegmatites in higher altitudes

作　　者：秦克章[1,2] 周起凤 赵俊兴 何畅通[1,2] 刘小驰 施睿哲[1,2] 刘宇超 QIN Kezhang;ZHOU Qifeng;ZHAO Junxing;HE Changtong;LIU Xiaochi;SHI Ruizhe;LIU Yuchao(Key Laboratory of Mineral Resources,Institute of Geology and Geophysics,Beijing 100029,China;Chinese Academy of Sciences,College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Institute of Mineral Resources Research,China Metallurgical Geology Bureau,Beijing 101300,China;State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China)

机构地区：[1]中国科学院矿产资源研究重点实验室,中国科学院地质与地球物理研究所,北京100029 [2]中国科学院大学地球与行星科学学院,北京100049 [3]中国冶金地质总局矿产资源研究院,北京101300 [4]岩石圈演化国家重点实验室,中国科学院地质与地球物理研究所,北京100029

出　　处：《地质学报》2021年第10期3146-3162,共17页Acta Geologica Sinica

基　　金：第二次青藏高原综合科学考察项目(编号2019QZKK0806和2019QZKK0802);中国科学院重点部署项目(编号ZDRW-ZS-2020-4-1)联合资助的成果。

摘　　要：喜马拉雅淡色花岗岩作为新识别的稀有金属成矿区带,已发现以Be-Nb-Ta(Sn-W)组合为主矿化且已形成大型矿床,如错那洞,但仅在为数不多的几处伟晶岩见到锂辉石,尚未发现工业锂矿床。因此,有必要剖析该区伟晶岩成矿(尤其Be同Li的对比)特点、条件及可能潜力,并与国内其他稀有金属矿带进行对比分析,从而推动喜马拉雅伟晶岩稀有金属矿床尤其是锂矿的发现。该区伟晶岩母体淡色花岗岩与华南稀有金属矿化花岗岩类似,显示高的分异程度但较窄的演化区间,并且熔体具有高的Li浓度。在印亚大陆碰撞带复杂的构造-变质-深熔作用下产生了多期次的岩浆活动,尤其新喜马拉雅期巨量的岩浆可为伟晶岩的形成、远距离迁移分异及成矿提供有利的热和物质基础。基于含Li伟晶岩形成于"远"母体、"高"海拔的特点,提出区域构造层位的上部或更高海拔地区以及淡色花岗岩岩体外侧远端的围岩内将可能是含锂伟晶岩的就位空间与找矿重点地段。The mineralization of Himalayan leucogranite in the newly identified rare-metal metallogenic belt,including the proven large deposit as Cuonadong,is dominated by the Be-Nb-Ta(Sn-W)assemblage.Although the spodumene-bearing pegmatite occurred in a few outcrops,so far no industrial lithium deposit has been found.The analysis and comparison of the characteristics,conditions and possible potential of Himalayan pegmatite mineralization(especially Be/Li)with other pegmatite rare element ore belts in China will promote the discovery of Himalayan pegmatite deposits,especially lithium deposits.The parental leucogranites are similar to the rare metal mineralized granite from South China,showing a highly fractionated but narrow evolution span and high melt Li concentration.In the Indo-Asian continental collision zone,the complex tectonic-metamorphic-anatectic process caused multi-period magmatic activity,especially the massive magma during the Neo-Himalayan period can provide favorable heat and material for the formation of pegmatitic melts,long-distance migration and differentiation,and mineralization.Based on the characteristics of Li-bearing pegmatites formed in the distant parental granite and high altitude,we propose that the upper part of the regional tectonic horizon or higher altitude spots and the surrounding rocks at the distal end of the leucogranite may be the suitable emplacement space and the key prospecting area of Li-bearing pegmatite.

关 键 词：喜马拉雅淡色花岗岩 伟晶岩结构 矿化分带 高演化 向远离母岩体的更高处找锂 

分 类 号：P618.72[天文地球—矿床学]