摘要
对与花岗岩有关的锡矿床中锡的成矿机制及相关研究进展进行归纳和总结。研究结果表明:锡成矿作用在时间和空间上与花岗岩密切相关,花岗岩为锡成矿提供了重要物源和成矿场所。花岗岩类型、变质沉积基底的重熔、岩浆源区及演化、熔体物化条件及锡在熔体中的存在形式等都是锡富集的重要控制因素;锡在熔体-流体间的分配行为可以解释锡的富集-沉淀机制。锡石为锡矿床中主要的矿石矿物,研究锡石的地球化学特征可以了解锡矿床的形成机制;锡石原位U-Pb定年技术已成为限定锡矿床年龄的主要手段,锡石的U-Pb定年结果可为研究锡矿床多期次成矿作用和矿集区成矿动力学背景提供更精准的年龄依据;锡石的微量元素在揭示锡石沉淀时的物理化学环境、锡矿床的成矿流体来源和成矿动力学等方面有着重要的指导意义;锡石的溶解再沉淀模式为判定锡石多期次流体活动性质提供了新的思路。锡同位素作为新兴的非传统稳定同位素,在示踪金属矿床成矿作用、揭示成矿元素的源运储行为、还原金属矿床成矿过程等方面将发挥重要的作用。新的原位分析测试手段(如NanoSIMS)的应用有助于锡的富集与沉淀机制研究、锡石与锡矿床的成因判断等。
The mechanism of tin mineralization and related research progress in tin deposits related to granites was summarized.The results show that tin mineralization is closely related to granite in time and space,which provides an important material source and site for tin mineralization.Types of granite,remelting of metamorphic sedimentary basement,source area and evolution of magma,physical and chemical conditions of melt,and morphology of tin in melt are important controlling factors of tin enrichment.The mechanism of tin enrichment and precipitation can be explained by the partitioning behavior of tin between melt and fluid.Moreover,cassiterite is the main ore mineral in tin deposits,and the formation mechanism of tin deposits can be understood by studying cassiterite geochemistry.In situ U-Pb dating of cassiterite has become a major tool for tin deposits age determination,which can provide more accurate age basis for the multi-phase tin mineralization and metallogenic dynamic background study.Trace elements in cassiterite are important guides to reveal the source of ore-forming fluids,the physicochemical environment of precipitation and the kinetics of mineralization.The dissolutionreprecipitation model of cassiterite provides new ideas for determining the nature of multi-phase fluid activity in cassiterite.Tin isotopes,as emerging unconventional stable isotopes,will play an important role in tracing metal deposit mineralization,revealing the source,transport and storage of mineralized elements in metallogenic deposits and reconstructing the mineralization process of metallic deposits.The application of new in-situ analytical methods(e.g.,NanoSIMS) is helpful in the study of tin enrichment and precipitation mechanisms,and the genesis of cassiterite and tin deposits.
作者
任涛
李欢
REN Tao;LI Huan(School of Geosciences and Info-Physics,Central South University,Changsha 410083,China;Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring,Central South University,Changsha 410083,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2022年第2期514-534,共21页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(92162103)
国家重点研发计划项目(2018YFC0603902)。
关键词
锡矿床
花岗岩
岩浆分异
氧逸度
熔体组分
锡石
tin deposits
granite
magma differentiation
oxygen fugacity
melt fraction
cassiterite
