成都理工大学学报（自然科学版）2024，Vol.51Issue(6)：1032-1047,16.DOI:10.3969/j.issn.1671-9727.2024.06.11
Li同位素在花岗伟晶岩型稀有金属成矿体系中的应用
Applications of Li isotopes in the study of granitic pegmatite-hosted rare metal deposits:A case study from the Songpan-Ganze-West Kunlun granitic pegmatite-type rare metal metallogenic belt
摘要
Abstract
The Li isotope method,as a new and nontraditional isotope method,can provide important information to understand the origin and genesis of granitic pegmatite-type Li deposits.Based on previous works,we collect and summarize Li isotope data of granites,pegmatites,and corresponding metasedimentary rocks from typical rare metal deposits in the Songpan-Ganze-West Kunlun metallogenic belt.Based on the similar δ7 Li values between granites and metasedimentary rocks,we propose that the primary granitic magma originated from partial melting of metasediments at deep crustal levels.Notably,the δ7 Li values of parts of the granites are higher than those of the metasediments,which indicate that devolatilization fluids from the lower crust may be involved during crust partial melting.The Li isotopes of the pegmatites are consistent with those of the granites,suggesting that the pegmatites have genetic affinities with granitic magma.Both equilibrium fractionation and diffusional fractionation control the Li isotope fractionation of pegmatite,during which processes such as fluid exsolution and the separation of H2O-rich pegmatitic melt/fluids take place.This complex fractionation mechanism leads to the varied δ7 Li values from Li-poor to Li-rich pegmatite.Although there are some challenges for applications of the Li isotope method to granitic pegmatite deposits,it is believed that the Li isotope method has the potential to enhance rare metal metallogenic theory and mine exploration,and may be an important geochemical method in future research.关键词
Li同位素/花岗岩/伟晶岩/稀有金属/松潘—甘孜—西昆仑Key words
Li isotopes/granite/pegmatite/rare metal/Songpan-Ganze-West Kunlun分类
天文与地球科学引用本文复制引用
李芬,柴建华,严清高,江小均,孔志岗..Li同位素在花岗伟晶岩型稀有金属成矿体系中的应用[J].成都理工大学学报（自然科学版）,2024,51(6):1032-1047,16.基金项目
自然资源部三江成矿作用及资源勘查利用重点实验室开放课题(ZRZYBSJSYS2021001) （ZRZYBSJSYS2021001）
云南省重大科技项目(202202AG050006) （202202AG050006）
云南省科技计划项目企业基础研究应用基础研究联合专项(202101BC070001-003). （202101BC070001-003）
