桂林理工大学学报2025，Vol.45Issue(2)：135-146,12.DOI:10.3969/j.issn.1674-9057.2025.02.001
湖南大义山地区含锂花岗岩演化特征
Evolutionary features of lithium-enriched granite in Dayishan area,Hunan
摘要
Abstract
The Dayishan area of Hunan province is located in the transition zone between Yangtze and Cathay-sian Block,also is in the superposition of Qinhang metallogenic belt and Nanling metallogenic belt.The Dayis-han pluton is characterized by multiple stages of intrusion and strong alteration.The lithium-bearing granites in Dachongli mining area can be divided into three stages of intrusions:medium-grained porphyritic biotite monzogranite(ηγJ3a),fine-grained porphyritic two-mica monzogranite(ηγJ3b)and fine-grained two-mica monzogranite(ηγJ3c).In order to reveal the mechanism of lithium mineralization,this paper takes petrogeo-chemistry as the starting point to explore the characteristics of granite evolution.It is found that the average con-tent of SiO2 in granite of Dachongli mining area is 75.13％,Na2O+K2O is 5.99％,10 000 × Ga/Al is 3.88,and TFeO/MgO is 21.70.It has a flat"seagull shaped"REE patterns,enriched in Rb,Th,U and Y,with loss of Ba and Sr.It belongs to A-type granite.In Yb-Ta and Y-Nb diagrams,most of the granites in Dachongli min-ing area drop point into the range of intraplate granite.Combined with previous studies,it is believed that they are formed in the early Yanshan intracontinental extensional environment.From early to late stages,each stage of granite follows the law of magmatic evolution,with ∑REE,LREE,HREE,LREE/HREE,Th,Zr and Hf values decreasing,while Li,W,Sn,Bi,Rb,U and Nb are increasing.The average content of Li varies from 538×10-6→734×10-6→2 218×10-6,with a coefficient of 21.2％→29.8％→74.3％,which reflects that Li is more enriched and more conducive to mineralization in the fine-grained two-mica monzonitic granite of the late stage.关键词
花岗岩演化/岩石地球化学/含锂花岗岩/大义山/南岭Key words
granite evolution/petrogeochemistry/lithium-enriched granite/Dayishan/Nanling分类
天文与地球科学引用本文复制引用
梁恩云,曾志方,刘庚寅,曾广乾,邹光均,许若潮,赵伟..湖南大义山地区含锂花岗岩演化特征[J].桂林理工大学学报,2025,45(2):135-146,12.基金项目
湖南省地质院科技计划项目(HNGSTP202317 （）
HNGSTP202323) （）
湖南省自然资源厅项目(2022008) （2022008）
