投稿时间：2021-04-22
修订日期：2021-06-18
网络发布日期：2021-08-30
中文摘要:铌钽铁矿族矿物（CGM）是重要铌、钽矿石矿物，记录了花岗伟晶岩型稀有金属矿床的岩浆热液演化过程。扎乌龙位于四川省西部石渠县，为大型花岗伟晶岩型稀有金属矿床。文章以扎乌龙14号伟晶岩脉为研究对象，开展了系统的铌钽铁矿族矿物研究工作。14号伟晶岩脉分带良好，从边部到中心可划分为云母石英电气石带（Ⅰ带）、斜长石带（Ⅱ带）、钠长石锂辉石带（Ⅲ带）和石英锂辉石带（Ⅳ带），均发育有铌钽铁矿族矿物。根据矿物内部结构和化学成分，推断14号伟晶岩脉存在2个阶段铌钽矿化：早阶段在各带内均形成铌铁矿-铌锰矿（CGM-1），内部呈现均一结构或振荡环带，指示以铌结晶为主的岩浆阶段；晚阶段在Ⅲ带和Ⅳ带内形成钽铁矿和少量富钽的铌铁矿-铌锰矿（CGM-2），围绕早阶段铌铁矿-铌锰矿再生长或穿切、交代早阶段铌钽矿物，指示以钽结晶为主的岩浆-热液过渡阶段。铌钽铁矿族矿物呈现出2种演化趋势，分别为早阶段铌铁矿-铌锰矿的Mn/（Mn+Fe）比值随着Ta/（Ta+Nb）比值升高而增加，晚阶段富钽矿物Mn/（Mn+Fe）比值随着Ta/（Ta+Nb）比值升高而不变，指示扎乌龙14号伟晶岩脉总体为中等程度分异，早期岩浆阶段各带内连续、晚期岩浆-热液阶段发生跳跃的不连续演化过程，并指示早阶段演化受岩浆结晶分异的控制、晚阶段演化主要受结晶分异、富Li流体环境和其他含Fe-Mn矿物共同控制的地球化学行为。
Abstract:As a kind of most important niobium and tantalum ore minerals, columbite-tantalum group minerals (CGMs) have recorded the magmatic hydrothermal evolution of granitic pegmatite type rare metal deposits. The Zhawulong deposit is one of large granitic pegmatite-type rare metal deposits in Shiqu County, west Sichuan Province. In this study, CGMs from No. 14 albite-spodumene pegmatite in the Zhawulong deposit were analyzed systematically. No. 14 pegmatite is well zoned and could be divided into muscovite-quartz-tourmaline zone (zone Ⅰ), plagioclase zone (zone Ⅱ), albite-spodumene zone (zone Ⅲ) and quartz-spodumene zone (zone Ⅳ). CGMs are well developed in all zones. According to the internal structure and chemical composition, two stages of CGMs could be recognized:① columbite-(Fe) and columbite-(Mn), called CGM-1, which display homogeneous or oscillatory zoned texture and show an increasing trend of Mn/(Mn+Fe) and Ta/(Ta+Nb) at the magmatic stage; ② some primary CGM-1, which displays overgrowth by later minerals of Ta enrichment (CGM-2) and shows no obvious change of Mn/(Mn+Fe) and an increasing trend of Ta/(Ta+Nb) at the magmatic-hydrothermal stage. The trend of Mn/(Mn+Fe) and Ta/(Ta+Nb) ratios indicates continuous evolution at the magmatic stage and discontinuous evolution at the magmatic-hydrothermal stage in overall medium differentiation along Zhawulong No.14 pegmatite vein. The CGM-1 grains were controlled by magmatic crystallization differentiation, while CGM-1 grains were controlled by crystallization differentiation, Li-rich fluid volatiles and other Fe-Mn bearing minerals. Keywords:geology, granitic pegmatite, columbite-tantalum group minerals, evolution, Zhawulong lithium deposit, western Sichuan
keywords:geology granitic pegmatite columbite-tantalum group minerals evolution Zhawulong lithium deposit western Sichuan
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基金项目:本文得到国家重点研发计划（编号：2019YFC06050203、2019YFC06505202）、中国地质调查局地质大调查项目“战略性新兴产业矿产调查”工程项目“松潘-甘孜成锂带锂铍多金属大型资源基地综合调查评价”（编号：DD20190173）、国家自然科学基金资助项目（编号：41872096、42002109、41703048）、中央级公益性科研院所基本科研业务费专项基金（编号：KK2004）联合资助
引用文本：
熊欣,李建康,王登红,李兴杰,王臻,张珈铭,严清高.2021.川西扎乌龙花岗伟晶岩型稀有金属矿床铌钽铁矿族矿物特征及其意义[J].矿床地质,40(4):693~705XIONG Xin,LI JianKang,WANG DengHong,LI XingJie,WANG Zhen,ZHANG JiaMing,and YAN QingGao.2021.Mineralogical characteristics of columbite-tantalite group minerals in Zhawulong granitic pegmatite-type rare metal deposit of western Sichuan and their geological implications[J].Mineral Deposits40(4):693~705
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