新疆西昆仑木吉地区锂铍稀有金属伟晶岩锆石及铌钽铁矿U-Pb年代学、Hf同位素组成及其地质意义  

Zircon and columbite-tantalite U-Pb geochronology of Li-Be rare metal pegmatite and its geological significance in Muji area, West Kunlun, China

作　　者：王核[1,2] 高昊 王赛蒙 闫庆贺 王振宏 黄亮 秦艳 WANG He;GAO Hao;WANG SaiMeng;YAN QingHe;WANG ZhenHong;HUANG Liang;QIN Yan(CAS Key Laboratory of Mineralogy and Metallogeny,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China;University of Chinese Academy of Sciences,Beijing 100049,China;Guangdong Nonferrous Metals Geological Exploration Institution,Guangzhou 510089,China)

机构地区：[1]中国科学院广州地球化学研究所矿物学与成矿学重点实验室,广州510640 [2]中国科学院大学,北京100049 [3]广东省有色地质勘查院,广州510089

出　　处：《岩石学报》2022年第7期1937-1951,共15页Acta Petrologica Sinica

基　　金：第二次青藏高原综合科学考察(2019QZKK0802);国家自然科学基金项目(91962215、41972088);新疆维吾尔自治区科技重大专项、重点研发专项(2019B00011、2020A03005);国家重点研发项目(2019YFC0605201)联合资助.

摘　　要：木吉是西昆仑造山带西段最为典型的含锂铍稀有金属伟晶岩脉发育的地区。本文通过LA-ICP-MS锆石、铌钽铁矿U-Pb方法限定了含锂铍稀有金属伟晶岩脉及二云母花岗岩的就位年龄。卡拉瓦拉二云母花岗岩锆石U-Pb年龄为207.5±1.1Ma,肖尔布龙含锂铍伟晶岩锆石、铌钽铁矿U-Pb年龄分别为204.8±0.7Ma、204.7±1.8Ma。伟晶岩锆石ε_(Hf)(t)值介于-5.3~-4.1,卡拉瓦拉二云母花岗岩锆石ε_(Hf)(t)值介于-6.9~-5.8。含锂铍伟晶岩脉与卡拉瓦拉二云母花岗岩密切的时空联系以及一致的Hf同位素比值,表明二云母花岗岩为成矿母岩体。从区域上看,木吉地区伟晶岩位于西昆仑造山带西部,与东部的大红柳滩、白龙山锂矿就位时间相似(207~212Ma),为西昆仑稀有金属成矿带的重要组成部分。Muji is the most typical area where rare metal pegmatite veins containing lithium and beryllium are developed in the western section of the West Kunlun orogenic belt,Northwest China.In this paper,the emplacement age of rare metal pegmatite and nearby granites is limited by LA-ICP-MS zircon and coltan U-Pb method.Zircon U-Pb age of Kalawala two-mica granite was 207.5±1.1Ma.Zircon and coltan yield ^(206)Pb/^(238)U ages of 204.8±0.7Ma and 204.7±1.8Ma,respectively,representing the emplacement ages of the Xiaoerbulong pegmatites.The ε_(Hf)(t)value of rare metal pegmatite zircon ranges from-5.3 to-4.1,and the ε_(Hf)(t)value of zircon from Kalawala granite ranges from-6.9 to-5.8.The rare metal pegmatite veins are closely related in time-space to the Kalawala granite and the consistent Hf isotope ratio,indicating that the two-mica granite is the ore-forming parent rock.From a regional perspective,the Muji pegmatite is located in the west of the West Kunlun orogenic belt,with a similar emplacement time(207~212Ma)to the Dahongliutan and Bailongshan lithium deposits in the east,and is the important part of the West Kunlun rare metal metallogenic belt.

关 键 词：木吉 肖尔布龙锂铍矿床 二云母花岗岩 锆石及铌钽铁矿U-Pb年龄 西昆仑 

分 类 号：P588.121[天文地球—岩石学] P597.3[天文地球—地质学] P618.6