湘南尖峰岭花岗质岩浆成因、成岩动力学背景及其稀有金属成矿意义  

Petrogenesis and diagenetic dynamic background of granitic magmas in Jianfengling,Southern Hunan and its significance for rare metals mineralization

作　　者：成永生[1,2,3] 毛春旺 张泽文 徐卓彬[1,2,3] 万方来 黄建中 陈剑锋 曹创华[6] 文春华 周瑶 王丹平 CHENG Yongsheng;MAO Chunwang;ZHANG Zewen;XU Zhuobin;WAN Fanglai;HUANG Jianzhong;CHEN Jianfeng;CAO Chuanghua;WEN Chunhua;ZHOU Yao;WANG Danping(Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring,Ministry of Education,Central South University,Changsha 410083,China;Key Laboratory of Non-Ferrous Resources and Geological Hazard Detection,Changsha 410083,China;School of Geosciences and Info-Physics,Central South University,Changsha 410083,China;Liaoning Sixth Geological Brigade Co.Ltd.,Dalian 116200,China;Geological Bureau of Hunan Province,Changsha 410014,China;Hunan Institute of Geological Survey,Changsha 410116,China)

机构地区：[1]中南大学有色金属成矿预测与地质环境监测教育部重点实验室,湖南长沙410083 [2]有色资源与地质灾害探查湖南省重点实验室,湖南长沙410083 [3]中南大学地球科学与信息物理学院,湖南长沙410083 [4]辽宁省第六地质大队有限责任公司,辽宁大连116200 [5]湖南省地质院,湖南长沙410014 [6]湖南省地质调查所,湖南长沙410116

出　　处：《中南大学学报（自然科学版）》2023年第9期3518-3534,共17页Journal of Central South University:Science and Technology

基　　金：湖南省重点研发计划项目(2019SK2261,2023SK2006,2022SK2072);中南大学研究生自主探索创新项目(2023ZZTS0729,2022ZZTS0503);湖南省自然科学基金资助项目(2023JJ50057);长沙市自然科学基金资助项目(kq2202090);自然资源部重点实验室开放课题(BL202105);湖南省科技创新领军人才项目(2020RC4003);湖南省科技人才托举工程项目(2020TJ-Q01);湖南省自然资源科技计划项目(2021-21);国家自然科学基金资助项目(41672076,42130810);湖南省杰出青年科学基金资助项目(2016JJ1022);湖南省科技创新团队项目(2021RC4055)。

摘　　要：产于香花岭矿田的尖峰岭矿床是在湘南地区已发现的唯一一处大型花岗岩型Li-Nb-Ta稀有金属矿床,该矿床成矿作用与尖峰岭岩体关系密切,是开展湘南花岗岩型稀有金属成矿研究的最佳天然基地。针对湘南稀有金属花岗质岩浆演化、构造背景及其成因机制以及稀有金属元素的富集成矿等问题,选取与稀有金属成矿关系紧密的尖峰岭岩体为对象,对正长花岗岩和二长花岗岩开展岩石学、矿物学以及岩石地球化学研究。研究结果表明:尖峰岭花岗岩为高硅(w(SiO_(2))为72.98%~77.36%,其中,w为质量分数)、过铝质(w(Al_(2)O_(3))/[w(CaO)+w(NaO)+w(K_(2)O)]≥1.11)、富F(平均w(F)=1.08%)的钙碱性—高钾钙碱性花岗岩;主微量元素均呈现“逆向演化”趋势,绿泥石化可能造成部分正长花岗岩w(Na_(2)O)极低(0.03%~0.05%);Nb、Ta、Li、Rb等微量元素富集,Sr、P、Ti亏损,w(Sm)/w(Nd)(0.27~0.32)表现出幔源花岗岩特点;稀土元素配分曲线呈现出略微右倾的“海鸥”型,同时具有“四分组效应”,属A型花岗岩。花岗质岩浆演化过程可能主要受制于富F、富H_(2)O的岩浆-热液体系,Nb、Ta、Li等稀有元素于岩石顶部富集成矿,其成岩构造环境具有CCG(大陆碰撞花岗岩)和POG(后造山花岗岩)的特点,可能形成于大陆碰撞后地壳伸展减薄的构造阶段,加之构造-岩浆演化的耦合作用,共同制约着尖峰岭地区稀有金属元素的富集成矿。The Jianfengling deposit exposed in Xianghualing ore field is the only large granite type Li,Nb,Ta rare metal deposit in southern Hunan.The mineralization of the deposit is closely interrelated to Jianfengling rock mass,and it is the best natural base for the study of granite type rare metal mineralization in southern Hunan.For the study of the evolution,tectonic background and formation mechanism of rare metalgranitic magma and mineralization of rare metal elements in southern Hunan.Jianfenglin rock mass was selected as the object,which had close relations with rare metal mineralization.Petrology,mineralogy and rock geochemical researchon syenogranite and monzogranite were stutied.The results show that Jianfengling granite is characterized by calc-alkaline-high potassium calc-alkaline granites with high-silicon(w(SiO_(2))is 72.98%−77.36%,in which w represents mass fraction),peraluminous(w(Al_(2)O_(3))/[w(CaO)+w(NaO)+w(K_(2)O)]≥1.11)and high F(average w(F)=1.08%).Both major and trace elements show a trend of"reverse evolution",and chloritization may result in an extremely low w(Na_(2)O)(0.03%−0.05%)in some syenogranite.Trace elements such as Nb,Ta,Li and Rb are enriched,while Sr,P and Ti are depleted,and w(Sm)/w(Nd)(0.27−0.32)shows the the rocks have the characteristics of mantle-derived granite.The rare earth element distribution curve shows a slightly rightward dipping"seagull"type and exhibits a"four group effect",belonging to the A-type granite.The granitic magmatic evolution may be mainly controlled by the magmatic hydrothermal system riched in F and H_(2)O,and Nb,Ta,Li and other rare elements are enriched and mineralized at the top of the rock mass.The diagenetic tectonic environment of the rock mass has the characteristics of CCG(continental collision granite)and POG(post-orogenic granite),which may belong to the tectonic environment of crustal extension and thinning after continental collision;coupled with the coupling effect of tectono-magmatic evolution,and the enrichment and mineralization of r

关 键 词：尖峰岭 花岗岩 岩石成因 岩浆演化 成岩动力学背景 稀有金属成矿 

分 类 号：P595[天文地球—地球化学]