Unveiling Nb-Ta mineralization processes:Insight from quartz textural and chemical characteristics in the Songshugang deposit,Jiangxi Province,South China  

作　　者：Hengsong Zhang Shaohao Zou Xilian Chen Deru Xu Zhilin Wang Yongwen Zhang Hua Wang 

机构地区：[1]State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang 330013,Jiangxi,China [2]School of Earth Sciences,East China University of Technology,Nanchang 330013,Jiangxi,China [3]Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring,Ministry of Education,School of Geosciences and Info-Physics,Central South University,Changsha 410083,China [4]Jiangxi Mineral Resources Guarantee and Service Center,Nanchang 330025,Jiangxi,China

出　　处：《Acta Geochimica》2024年第4期737-753,共17页地球化学学报（英文）

基　　金：the National Natural Science Foundation of China(Nos.41930428,U2344205,42363009,42002089);the Jiangxi Provincial Natural Science Foundation(Nos.20224BAB213040,20224BAB203036,20224ACB203008);the DHBK project from East China University of Technology(DHBK2019320);the Graduate Innovation Fund from East China University of Technology(YC2023-S554).

摘　　要：The Songshugang deposit is a large Ta-Nb deposit in South China,with Ta-Nb mineralization associated genetically with the granite and pegmatite.A diversity of quartz from topaz-albite granite,quartz-mica pegmatite,quartz-feldspar pegmatite,and quartz-fluorite pegmatite at Songshugang was studied by CL and LA-ICP-MS in order to constrain enrichment mechanisms of Nb and Ta and to find geochemical indicators of quartz for rare metal deposits.Cathodoluminescence image illuminates a canvas of complexity,the quartz from topaz-albite granite,quartz-mica pegmatite,quartz-feldspar pegmatite,and quartz-fluorite pegmatite,exhibits numerous dark CL streaks,patches,and a series of healed fractures.These textures suggest that the rocks were fractured because of deep crustal pressure,and underwent later hydrothermal metasomatism and quartz filling.The quartz from quartz-fluorite pegmatite present limited patches or fractures but distinct growth bands,indicating that the melt fluid composition during the formation of quartz at this stage varies greatly and is less aff ected by mechanical fragmentation.The LA-ICP-MS analysis of quartz shows that there is a positive correlation between Al and Li in the quartz from topaz-albite granite,quartz-mica pegmatite,quartz-feldspar pegmatite,to quartz-fluorite pegmatite,indicating that Al mainly enters the quartz lattice through charge compensation substitution mechanism with Li.However,our data deviate from the theoretical Li:Al mass ratio of~1:3.89 in quartz,indicating that there may be competition between H^(+)and Li in a water-rich magmatic environment.The quartz from topaz-albite granite is enriched in K and Na elements,and the quartz from quartz-fluorite pegmatite is enriched in fluorite with a low Ca content in quartz,further elucidating that these rocks were subjected to hydrothermal metasomatism.From topaz-albitite granite to quartz-fluorite pegmatite,Al,Li and Ge content and Al/Ti,Ge/Ti,Sb/Ti ratios in quartz gradually increased,but Ti content gradually decreased,reflecting the hi

关 键 词：Nb-Ta deposit QUARTZ CATHODOLUMINESCENCE LA-ICP-MS Trace elements Magma-hydrothermal evolution 

分 类 号：P618.79[天文地球—矿床学] P618.86[天文地球—地质学]