投稿时间：2019-06-04
修订日期：2019-07-01
网络发布日期：2019-08-26
中文摘要:仁里稀有金属矿田位于幕阜山岩体西南缘，是华南地区重要的稀有金属矿产地之一。文章旨在通过对区域成矿条件、矿田地质特征、地球化学特征、成岩成矿时代与稀有金属成矿作用的综合分析，为矿田勘查设计乃至华南地区稀有金属找矿与研究提供理论依据。在矿田范围内对燕山期、武陵期花岗岩及每个矿区代表性伟晶岩进行了系统采样，开展了岩石化学成分分析，同时对矿田内二云母二长花岗岩及锂辉石伟晶岩分别进行了锆石U-Pb、白云母Ar-Ar同位素定年。研究表明：①多期造山与燕山期陆内活化是成矿的有利地质背景，多阶段伸展作用导致幕阜山地区多期大规模的多金属成矿作用发生；②矿田构造主要以NE（或NNE）向构造为主，复合改造NW向及近EW向构造，NE（或NNE）向和NW（或近EW）向构造呈现立交桥式的构造格局，控制了花岗岩和伟晶岩分布；③矿田内伟晶岩属极高分异、富硅、过铝质花岗质岩石，燕山期花岗岩属陆壳改造"S型"花岗岩；④幕阜山岩体由岩体内接触带往岩体外接触带（10 km），由黑云母伟晶岩→二云母伟晶岩→白云母伟晶岩→锂云母伟晶岩→锂辉石白云母伟晶岩过渡，形成了较完整的稀有金属演化序列：无矿化→Be→Be+Nb+Ta→Be+Nb+Ta+Li→Be+Nb+Ta+Li+Cs；⑤稀有金属成矿与构造岩浆时空演化、构造组合、特别是岩浆的分异程度密切相关，矿田内燕山期花岗岩年龄139.3~146.2 Ma，稀有金属成矿年龄为130.5~130.8 Ma。
Abstract:Located on the southwestern margin of Mufushan batholith, the Renli rare metal orefield is one of the most important rare metal deposits in South China. The purpose of this study is to provide a theoretical basis for the prospecting and study of rare metal deposits in South China through a comprehensive analysis of regional metallogenic conditions, geological characteristics, geochemical characteristics, petrogenic and metallogenic epochs and metallogenic characteristics of the Renli rare metal deposit. The Yanshanian and Wuling granites and representative pegmatites in each mining area were systematically sampled, and element composition tests were carried out. Zircon U-Pb and muscovite Ar-Ar isotopic dating was carried out for the two-mica monzonitic granite and spodumene pegmatite, respectively. Some conclusions have been reached:① Multi-stage orogeny and Yanshanian intracontinental activation constituted the favorable geological background of mineralization. The largescale polymetallic mineralization in Mufushan area was caused by the multi-stage extension process;② The orefield structures are mainly NE (or NNE) trending structures, which are combined with NW trending and nearly EW trending structures. The NE (or NNE) and NW (or nearly EW) trending structures exhibit an overpass structure pattern, which controls the distribution of granites and pegmatites;③ The pegmatite in the orefield show the characteristics of extremely highly differentiated, silica-rich and peraluminous granitic rocks, while the Yanshanian granite belongs to S-type granite of continental crust transformation; ④ The Mufushan batholith is composed of biotite pegmatite→two mica pegmatite→muscovite pegmatite→lepidolite pegmatite→spodumene muscovite pegmatite from the contact zone within the batholith to the southwest of the Renli deposit (10 km), forming a relatively complete evolution sequence of rare metals in order of barren→Be→Be+Nb+Ta→Be+Nb+Ta+Li→Be+ Nb+Ta+Li+Cs; ⑤ The rare metal mineralization was closely related to the spatio-temporal evolution of tectonic magma, tectonic association and especially the degree of differentiation of magma. The age of Yanshanian granite in the orefield ranges from 139.3 Ma to 146.2 Ma, and the mineralization age of rare metals from 130.5 Ma to 130.8 Ma.
keywords:geology multi-stage orogeny and intracontinental activation extensional process geochemical characteristics mineralization age Renli rare metal orefield Hunan
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基金项目:本文得到湖南省自然资源厅科研项目（编号：2018-02）、湖南省地勘基金项目（编号：20170331）、中国地质调查局项目（编号：DD20160056）和国家自然科学基金面上项目（编号：41872096）的联合资助
引用文本：
刘翔,周芳春,李鹏,李建康,黄志飚,石威科,黄小强,张立平,苏俊男.2019.湖南仁里稀有金属矿田地质特征、成矿时代及其找矿意义[J].矿床地质,38(4):771~791LIU Xiang,ZHOU FangChun,LI Peng,LI JianKang,HUANG ZhiBiao,SHI WeiKe,HUANG XiaoQiang,ZHANG LiPing,SU JunNan.2019.Geological characteristics and metallogenic age of Renli rare metal orefield in Hunan and its prospecting significance[J].Mineral Deposits38(4):771~791
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