中国花岗岩型锂矿床:重要特征、成矿条件及形成机制  

Granite-type lithium deposits in China:Important characteristics,metallogenic conditions,and genetic mechanism

作　　者：郭春丽[1,2] 张斌武 郑义 许箭琪 赵迁迁 闫金禹 周睿[3] 符伟 黄可 GUO ChunLi;ZHANG BinWu;ZHENG Yi;XU JianQi;ZHAO QianQian;YAN JinYu;ZHOU Rui;FU Wei;HUANG Ke(MNR Key Laboratory of Metallogeny and Mineral Assessment,Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037,China;SinoProbe Laboratory,Chinese Academy of Geological Sciences,Beijing 100094,China;China University of Geosciences,Beijing 100083,China;Central South University,Changsha 410083,China)

机构地区：[1]成矿作用与资源评价自然资源部重点实验室,中国地质科学院矿产资源研究所,北京100037 [2]自然资源部深地科学与探测技术实验室,中国地质科学院,北京100094 [3]中国地质大学,北京100083 [4]中南大学,长沙410083

出　　处：《岩石学报》2024年第2期347-403,共57页Acta Petrologica Sinica

基　　金：国家自然科学基金重点项目(92162210);面上项目(42172096);中国地质调查局项目(DD20221695)联合资助。

摘　　要：随着新能源汽车产业的快速发展和可控核聚变技术的不断革新,锂产业已成为各国竞相发展的新兴朝阳产业,全球锂资源争夺态势愈发激烈。中国是全球拥有花岗岩型锂矿床数量最多的国家,目前该类型锂矿占全国锂总供应量的1/4,进一步加强对该类型锂矿的研究和勘查对提升我国锂资源的自给能力至关重要。通过对全国40个主要花岗岩型锂矿床的时空分布、岩石序列、矿物演变、地球化学和锂独立矿物等特征的梳理,发现该类矿床主要形成于中生代晚侏罗世-早白垩世期间,主要集中在华南地区尤以华南腹地的南岭地区最为密集;近1/3的成矿岩体隐伏于地下,出露的岩体面积普遍较小,为0.07~5.7km^(2);花岗岩体垂直方向从下至上逐渐从黑云母二长花岗岩演变为锂云母钠长石花岗岩,其上通常发育云英岩和伟晶岩;锂及其他稀有元素(铷铯铍铌钽钨锡)一般在强钠长石花岗岩和云英岩中高度富集;黑云母二长花岗岩→含锂云母钠长花岗岩→云英岩,岩浆分异程度逐步增加且逐渐从熔体过渡到熔体-流体共存体系,全岩SiO_(2)含量、Nb/Ta和Zr/Hf比值、A/CNK和δEu值发生规律性变化;多数情况下岩体伴生煌斑岩脉、辉长岩脉、辉绿岩脉、花岗斑岩脉、细晶岩脉、霏细岩脉等各类脉体。总结规律提出:(1)伟晶岩壳是较早进入岩浆房内的岩浆与上覆围岩接触而冷却固结的产物,其构成岩浆房与外界的隔绝屏障,使Li、F、P、H_(2)O等易挥发组分无法逃逸;(2)较晚进入岩浆房的岩浆经历了长时间晶粥体与残留熔体的分凝过程,锂等稀有金属元素愈来愈富集于残余熔体中,最终形成富锂花岗岩和云英岩;(3)各类岩脉是岩浆房底部有持续热补给从而使残留含矿熔体能够逐步抽离上升的证据:基性岩脉来源于下伏高温地幔岩浆,不含矿中酸性斑岩脉是岩浆房底部堆晶体重熔的产物,含矿酸性斑岩�Due to the rapid development of the electric vehicle and the continuous innovation of controllable nuclear fusion,the competition of lithium supply capacity is happening all over the world.China has the most quantity of granitic-type lithium deposits in the world and this type of lithium deposits accounts for 1/4 of the total lithium supply in the country at present.So it is very important that the breakthrough not only the theoretical study but also the mineral exploration is crucial to enhance the self-sufficiency of lithium resources in China.In this work,by integrating the geology characteristics,rock sequence,mineral evolution,geochemistry and lithium independent minerals of 40 granitic-type lithium deposits in China,we found that:(1)They mainly formed in Late Jurassic to Early Cretaceous and focused in South China,especially in the Nanling range;(2)There are 1/3 of ore-forming granitic plutons are buried underground and the outcrop areas are commonly small with 0.07~5.7km^(2);(3)The plutons generally evolved from dark biotite-bearing monzogranite to light lepidolite-bearing albite granite from bottom to top in a vertical direction,with greisen and pegmatite at the top;(4)Li with other rare-metal elements including Rb,Cs,Be,Nb,Ta,W and Sn highly enriched in the albitie granite and greisen;(5)Biotite granite→Li-bearing albite granite→greisen,the crystal fractionation of magmas gradually inceased and the magma system gradually evolved towards melt-fluid coexistence.Moreover,the whole-rock SiO_(2)contents and values of A/CNK,Nb/Ta,Zr/Hf andδEu changed regularly;(6)Various types of dykes such as lamprophyre,gabbro,diabase,granite porphyry,aplite,and felsite are associated with the ore-bearing plutons in most cases.Based on above characteristics,we concluded that:(1)The pegmatite shell was the product generated the earliest by cooling and consolidation of magma batches,which were injected earlier in the magma reservoir by contacting with the cold wall-rock,so it formed a barrier between the magma reservoir a

关 键 词：岩浆房 高分异花岗岩 伟晶岩壳 各类岩脉 花岗岩型锂矿床 中国 

分 类 号：P588.121[天文地球—岩石学] P611[天文地球—地质学] P618.7