沉积与特提斯地质2025，Vol.45Issue(3)：581-593,13.DOI:10.19826/j.cnki.1009-3850.2025.07006
西藏嘎波锂矿床白云母花岗岩及电气石地球化学:对喜马拉雅后碰撞伸展背景下稀有金属成矿作用的启示
Geochemical characteristics of tourmaline-muscovite granite and tourmaline from the Gabo lithium deposit,Xizang:Implications for rare metal metallogenesis in the post-collision extensional setting of the Himalayas
摘要
Abstract
The Gabo lithium deposit in Xizang Autonomous Region is the first verified pegmatite-type lithium deposit within the Himalayan metallogenic belt,showing significant potential for large-scale exploration.The pegmatite-type lithium bodies are primarily hosted in the metamorphic rock series of the Paleozoic Guzi Formation,with their distribution controlled by extensional detachment structures.They have a close spatial relationship and genetic link with the underlying tourmaline-muscovite granite.However,further study on the magmatic properties and metallogenic potential of this granite remain lacking.To address this,this study conducted geochemical,mineralogical,and isotopic analyses on the tourmaline-muscovite granite.The results reveal that the granite is characterized by high silica content(SiO2:73.34%-74.46%),elevated alumina levels(Al2O3:14.52%-14.94%),low CaO content(0.92%-1.06%),enrichment in large ion lithophile elements,and depletion in high field strength elements.It exhibits notably high Rb concentrations(605×10-6-633×10-6)coupled with high Rb/Sr ratios(8.01-8.59),indicating that the granite was derived from the dehydration melting of phyllitic muscovite and underwent extensive differentiation.The boron isotopic compositions(δ11B)of tourmaline within the granite range from-11.61±0.38 to-10.47±0.35,suggesting a relatively homogeneous crustal source.In-situ trace element analyses of tourmaline show remarkably high contents of Li(900×10-6-1821×10-6),Zn(1 835.39×10-6-2 871.81×10-6),and Sn(31.56×10-6-87.83×10-6),with a gradual increase from the core to the rim.This indicates that magmatic differentiation and evolution drove the enrichment of rare metals,with tourmaline acting as a mineral indicator for rare metal concentration.Comprehensive research demonstrates that the enrichment of rare metals in the Gabo pegmatite-type lithium deposit is controlled by magmatic differentiation and evolution,while its occurrence is governed by extensional detachment structures.This makes it a typical example of rare metal mineralization in the post-collisional extensional setting of the Himalayan metallogenic belt.关键词
锂成矿作用/电气石/淡色花岗岩/后碰撞伸展阶段/嘎波Key words
lithium mineralization/tourmaline/leucogranite/post-collision extension stage/Gabo分类
天文与地球科学引用本文复制引用
石洪召,张林奎,刘洪,王艺云,郭伟康,付建刚..西藏嘎波锂矿床白云母花岗岩及电气石地球化学:对喜马拉雅后碰撞伸展背景下稀有金属成矿作用的启示[J].沉积与特提斯地质,2025,45(3):581-593,13.基金项目
国家重点研发计划"高纯石英原料矿床成矿规律与成矿预测研究"(2024YFC2910102) （2024YFC2910102）
中国地质调查局地质调查项目(DD20240071,DD20242113) （DD20240071,DD20242113）
