摘要
湖南界牌岭锡多金属矿床是南岭地区典型花岗斑岩型矿床之一,其稀有稀土矿化与花岗斑岩和灰岩围岩之间的蚀变作用密切相关.利用电子探针、LA-ICP-MS等仪器,对界牌岭锡多金属矿矿区的一系列蚀变岩石进行系统矿物学研究,探讨花岗斑岩与围岩的蚀变过程和稀有稀土金属的富集、迁移与成矿.结果表明:(1)蚀变花岗斑岩中斑晶主要为钾长石、石英和萤石,随着蚀变程度加剧,钾长石和石英斑晶逐渐减少,萤石斑晶逐渐增多,蚀变晚期广泛发育细粒萤石和云母;(2)稀有稀土金属矿化主要与基质钾长石和萤石结晶有关,形成了一系列铌钽氧化物、稀土矿物、锡矿物等,大量锂矿物和铍矿物则出现在花岗斑岩蚀变晚期,并伴有稀有稀土矿物的交代现象;(3)黄铜矿的出熔成因指示该矿床经历了高温热液蚀变过程,这为稀有稀土金属的迁移、富集提供了有利条件.
Jiepailing tin polymetallic deposit in Hunan Province is one of the typical granite porphyry deposits in Nanling area,where the mineralization of rare and rare-earth metals is closely related to the hydrothermal alteration between the granite porphyry and its surrounding limestone.In this paper,a series of altered rocks from Jiepailing tin polymetallic deposit are systematically studied by EPMA(Electron Probe Micro-Analyzer)and LA-ICP-MS,with the aims to discuss the alteration processes between granite porphyry and surrounding rock,and the concentration,migration and mineralization of rare and rareearth metals during these alteration processes.The results show below.(1)K-feldspar,quartz and fluorite occur as main phenocrysts in the altered granite porphyry.With the degree of alteration increasing,however,K-feldspar and quartz phenocrysts gradually decrease,fluorite phenocrysts gradually increase,and large amounts of fine-grained fluorite and mica are widely developed in the late stage of alteration.(2)The crystallization of rare and rare-earth minerals is mainly related to the formation of K-feldspar and fluorite matrix,forming a series of niobium tantalum oxides,rare earth minerals,tin minerals,etc.,while a large amount of lithium and beryllium minerals occur in the late stage of granite porphyry alteration,accompanied by the metasomatism of rare and rare-earth minerals.(3)The exsolution genesis of chalcopyrite indicates that the deposit experienced a high temperature hydrothermal alteration,which provides favorable conditions for the migration and concentration of rare and rare-earth metals.
作者
林晓青
饶灿
覃莉茜
吴润秋
王琪
Lin Xiaoqing;Rao Can;Qin Lixi;Wu Runqiu;Wang Qi(School of Earth Sciences,Zhejiang University,Hangzhou,310027,China)
出处
《南京大学学报（自然科学版）》
CAS
CSCD
北大核心
2020年第6期830-846,共17页
Journal of Nanjing University（Natural Science）
基金
国家自然科学基金(41772031)。
关键词
斑岩矿床
稀有金属
稀土金属
界牌岭
porphyry deposit
rare metals
rare earth metals
Jiepailing
