摘要
锂(Li)被国家列为了"关键金属"。位于四川西部的甲基卡稀有金属矿田锂资源得天独厚,累计查明氧化锂(Li2O)资源储量286.11万t,预测远景资源量500万t,是世界级硬岩型锂矿富集区。二云母花岗岩以含锂辉石、锂白云母、黑鳞云母以及电气石、磷灰石为特征。花岗岩细晶岩型锂矿为主体并与伟晶岩型锂矿共存,且发育韵律式条带结构是甲基卡矿田独有的特点。笔者以在甲基卡地区及外围调查研究与找矿勘探实践为基础,总结了甲基卡锂等稀有多金属矿田的成矿地质特征,从二云母花岗岩、伟晶岩脉以及韵律式条带结构、地球化学、包裹体等方面的特征,探讨了锂金属超常富集的成因,提出了甲基卡花岗岩浆多中心底辟穹隆、不混溶Li-F花岗质岩浆、半开放裂隙系统的脉动式多期充填-交代及花岗质岩浆结晶分异-自交代成岩成矿的认识。这一认识对稀有金属找矿具有重要意义,但对于稀有金属的分配、迁移、超常富集过程等科学问题还需要继续深入研究,以期更大的找矿突破。
Lithium(Li)is listed as a"key metal"by the Chinese Government.The rare metal ore field in western Sichuan is known for its unique and rich lithium resources.The accumulated lithium oxide(Li;O)reserves are 2.86 million tons and the prospective resource is 5 million tons.It is a world-class hard rock-type of lithium enrichment area.Two mica granite is characterized by spodumene,lepidolite,biotite,tourmaline and apatite.Granite microcrystalline lithium deposits are the main body and coexist with pegmatite lithium deposits.The ore field is also characterized by rhythmic band texture,which is a unique feature in the Jiajika area.We have summarized the metallogenic characteristics of the lithium-bearing rare polymetallic ore fields,such as those in the Jiajika area and their peripheries,including features of two mica granites,pegmatite veins and rhythmic band structure,geochemistry,inclusions,etc.We also discuss the cause of the supernormal enrichment of lithium metal,and propose a geological model with a multi-center(complex)diapir dome of the Jiajika granite magma,immiscible Li-F granitic magma,and a semi-open fracture system.Using such model,we have increased our understanding of multi-stage filling-metasomatism and crystallization differentiation of granitic magma-self-metamorphic diagenesis and mineralization.This development is of great significance to the prospecting of rare metals.However,scientific issues such as the distribution,migration,and extraordinary enrichment process of rare metals still need to be explored and studied to enable a greater breakthrough in prospecting.
作者
付小方
梁斌
邹付戈
郝雪峰
侯立玮
FU Xiaofang;LIANG Bin;ZOU Fuge;HAO Xuefeng;HOU Liwei(Sichuan Geological Survey,Chengdu,Sichuan 610081,China;School of Environment and Resources,Southwest University of Science and Technology,Mianyang,Sichuan 621010,China;Bauer School of Business,University of Houston,TX 77004,USA)
出处
《地质学报》
EI
CAS
CSCD
北大核心
2021年第10期3054-3068,共15页
Acta Geologica Sinica
基金
南京大学卓越研究计划“川西伟晶岩型锂矿科学钻探”项目
国家自然基金特提斯动力学研究计划项目(编号020613001175)
中国科学院学部学科发展战略研究项目(编号XK2018DXA01)
四川省地勘基金雅江县麦基坦(甲基卡海子北)锂矿普查项目(川国土资函(2015)55)联合资助的成果。
关键词
甲基卡
锂矿田
成矿地质特征
矿床成因
Jiajika
lithium ore field
metallogenic geological characteristics
metallogenesis
