四川阿坝可尔因锂矿田成矿规律与成矿预测  

Metallogenic regularity and exploration prediction of the Ke eryin lithium ore field in Aba,Sichuan

作　　者：李鑫 代鸿章[1] 王登红 刘善宝[1] 范小东[3] 梁志 高原 文佳豪[5] 朱海洋 LI Xin;DAI HongZhang;WANG DengHong;LIU ShanBao;FAN XiaoDong;LIANG Zhi;GAO Yuan;WEN JiaHao;ZHU HaiYang(MNR Key Laboratory of Metallogeny and Mineral Assessment,Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037,China;School of Earth Sciences and Resources,China University of Geosciences,Beijing 100083,China;Baotou Beidou Geological Exploration Co.,Ltd.,Baotou 014010,China;Inner Mongolia Dazhong Mining Co.,Ltd.,Bayan Nur 015000,China;School of Earth and Planetary Sciences,Chengdu University of Technology,Chengdu 610059,China;The Ninth Geological Brigade of Sichuan Province,Deyang 618000,China)

机构地区：[1]中国地质科学院矿产资源研究所,自然资源部成矿作用与资源评价重点实验室,北京100037 [2]中国地质大学(北京)地球科学与资源学院,北京100083 [3]包头市北斗地质勘查有限责任公司,包头014010 [4]内蒙古大中矿业股份有限公司,巴彦卓尔015000 [5]成都理工大学地球与行星科学学院,成都610059 [6]四川省第九地质大队,德阳618000

出　　处：《岩石学报》2024年第9期2819-2840,共22页Acta Petrologica Sinica

基　　金：国家重点研发计划(2021YFC2901900、2021YFC2901905);国家自然科学基金项目(42330806);中国地质调查局项目(DD20230034、DD20230055、DD20221695、DD20190379、DD20160346)联合资助.

摘　　要：青藏高原东北缘的松潘-甘孜造山带是我国最重要的锂矿成矿带,其中部地区的可尔因锂铍稀有金属矿田是最重要的伟晶岩型锂矿资源基地之一。本文在已开展的地质矿产调查及勘查工作的基础上,系统总结了矿田内典型矿床地质特征、矿床地球化学特征、成岩成矿时代,完善了可尔因锂矿田成矿模型,并进一步指出了区域找矿方向,对提升区域伟晶岩型锂矿成矿规律及指导深部找矿意义重大。矿田内矿床类型均为花岗伟晶岩型稀有金属矿床,矿石矿物主要为锂辉石。花岗岩-伟晶岩与西康群变沉积岩具有近一致的Sr-Nd-Hf同位素组成,指示成岩成矿物质来源于西康群。自花岗岩至伟晶岩,原生矿物和全岩δ^(7)Li值均升高,指示伟晶岩形成于花岗岩浆分异;自钠长石伟晶岩至钠长石锂辉石伟晶岩,原生矿物δ^(7)Li值升高,而全岩δ^(7)Li值降低,指示伟晶岩浆演化过程中的分离结晶和出熔流体富集。可尔因复式岩体与伟晶岩具有相重叠的同位素年龄,为同期造山作用的产物,形成于印支造山晚期构造体制由挤压转为伸展的造山阶段。基于以上特征,对前人提出的可尔因矿田成岩成矿模式进行了完善,认为富锂的源区、适宜的构造背景、充分且强烈的岩浆结晶分异协同富水流体的富集共同促进了可尔因锂矿田的形成。此外,总结了可尔因锂矿田的找矿标志,并预测了找矿方向。The Songpan-Garze orogenic belt on the northeastern margin of the Tibetan Plateau is one of China s most important lithium metallogenic belts,with the Ke eryin lithium ore field in the central region being one of the most significant pegmatite-type lithium resource bases.Based on extensive geological and mineral exploration and survey work,this paper systematically summarizes the geological characteristics,geochemical features,and magmatic and metallogenic ages of typical deposits within the ore field.It also refines the metallogenic model of the Ke eryin lithium ore field and further identifies regional exploration directions,which is of great significance for understanding the metallogenic regularity of pegmatite-type lithium deposits and guiding deep exploration.The deposit types within the ore field are all granite related pegmatite-type rare metal deposits,with spodumene being the primary ore mineral.The granite-pegmatite and the Xikang Group metasedimentary rocks have nearly identical Sr-Nd-Hf isotopic compositions,indicating that the source material for mineralization originated from the Xikang Group.From granite to pegmatite,both primary minerals and whole-rockδ^(7)Li values increase,indicating that pegmatite formed from the differentiation of granite magma.From albite pegmatite to albite-spodumene pegmatite,primary mineralδ^(7)Li values increase while whole-rockδ^(7)Li values decrease,suggesting fractional crystallization and enrichment of exsolved fluids during pegmatite magma evolution.The Ke eryin composite pluton and pegmatite share overlapping isotopic ages,indicating they are products of the same orogenic event,formed during the Late Indosinian orogenic stage when the tectonic regime transitioned from compression to extension.Based on these characteristics,the previously proposed magmatic and metallogenic model for the Ke eryin ore field has been refined,suggesting that a lithium-rich source area,suitable tectonic setting,extensive and intense magmatic fractional crystallization,and the enrichme

关 键 词：松潘-甘孜造山带 可尔因锂矿田 伟晶岩 成矿规律 成矿预测 

分 类 号：P588.131[天文地球—岩石学] P612[天文地球—地质学] P618.71