投稿时间：2019-06-10
修订日期：2019-06-30
网络发布日期：2019-08-26
中文摘要:为明确可尔因矿田岩浆演化过程中锂的迁移与富集，指明稀有金属矿床的找矿方向，文章通过野外地质观察、室内岩矿鉴定及云母LA-ICP-MS原位测试，发现随着岩浆分异程度的增强，云母由镁铁质黑云母演化为硅铝白云母，以云母Mg#/n（Li）值作为岩体分异程度指示，显示其与亲铁元素组合（V、Cr、Co、Ni）、稀碱金属（Li、Rb、Cs）、稀有金属（Nb、Ta、Sn）及稀散元素（Ga）和指示岩浆演化的元素对（Nb/Ta、K/Rb）均存在显著的相关性。根据岩体结晶环境、源区类型及云母结晶时对应熔（流）体中的Li含量，将可尔因矿田岩浆-热液活动划分为3期次7阶段，进而指出矿田内第三期次一、二阶段岩浆热液活动为Li迁移与富集的主要阶段。该过程中深源Li成矿元素和热量持续供给、早阶段岩体黑云母分解、三叠系围岩混染和上侵流体圈闭促成了富Li熔（流）体的形成与就位，表明矿田内及外围寻找岩浆型锂矿和三叠系层控富锂矿体的潜力。结合Li和其他稀有金属的相关性，指明了Sn、Nb、Ta等稀有金属元素的找矿方向。
Abstract:To confirm migration and enrichment regularity of Li in magmatic evolution and indicate the prospecting direction of Li and other rare metal deposits, the authors, based on field geological observation, mineral-rock identification, and mica in-situ test by Laser erosion inductively coupled plasma mass spectrometry, found that, with increase of magmatic differentiation, mafic biotite evolved into silicon-aluminum muscovite, and that the Mg#/n (Li) value of mica, as the indicator of rock differentiation degree, is significantly correlated with siderophile elements (V, Cr, Co, Ni), rare alkali metal elements (Li, Rb, Cs), dispersed element (Ga), rare metals (Nb, Ta, Sn, etc.) and ratio indicating magma evolution (Nb/Ta, K/Rb). According to pressure-temperature environment, type of magma source, and the Li content of melt (fluid) corresponding to mica crystal, the authors divided the magma-hydrothermal activities of the Ke'eryin orefield into three periods consisting of seven stages, and pointed out that the first and second stages of the third period magmatic hydrothermal activities were the main stages for the migration and enrichment of Li. The supply of ore-forming element Li and heat from deep source, the biotite decomposition of early stage rock mass, the contamination of Triassic formation and the fluid trap of rising emplacement by wall rock contributed to the formation and emplacement of lithium-rich melting/flow, which indicates that there exists potentiality in the search for magma-type lithium deposits and Triassic stratabound lithium orebodies. Combined with the correlation between Li and other minor metals, the authors pointed out the prospecting orientations for Sn, Nb, Ta and other rare metals.
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基金项目:本文为国家重点研发计划“深地资源勘查开发”专项“锂能源金属矿产基地深部探测技术示范”项目（编号：2017YFC0602700）“我国锂能源金属成矿规律、靶区优选与重点查证”课题（编号：2017YFC0602701）；中国地质调查局“战略性新兴产业矿产调查”工程“松潘-甘孜成锂带锂铍多金属大型资源基地综合调查评价”、“中国矿产地质志”等项目资助的成果
引用文本：
马圣钞,王登红,刘善宝,孙艳,郭伟明,代鸿章,刘丽君,李超.2019.川西可尔因锂矿田云母矿物化学及稀有金属成矿和找矿指示[J].矿床地质,38(4):877~897MA ShengChao,WANG DengHong,LIU ShanBao,SUN Yan,GUO WeiMing,DAI HongZhang,LIU LiJun,LI Chao.2019.Mineral chemistry of micas from Ke'eryin pegmatite type lithium orefield in western Sichuan and its indication for rare metal mineralization and prospecting[J].Mineral Deposits38(4):877~897
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