矿床地质2026，Vol.45Issue(4)：841-867,27.DOI:10.16111/j.0258-7106.2026.04.007
西藏包买铜钼矿床电气石矿物学特征及其对热液流体演化的指示
Mineralogical characteristics of tourmaline from Baomai Cu-Mo deposit,Xizang,and their implications for hydrothermal fluid evolution
摘要
Abstract
The Baomai deposit is a medium-sized porphyry Cu-Mo deposit located in the northern segment of the Yulong copper metallogenic belt,Xizang.The characteristics and evolutionary history of its magmatic-hydrother-mal fluids remain poorly constrained,which hinders an in-depth understanding of its metallogenic mechanism.Abundant tourmaline is widely developed within this deposit,which provides critical proxies for unraveling the evolution of magmatic-hydrothermal fluids and the ore-forming processes.Based on detailed core logging,petro-graphic microscopic observation,and electron probe microanalysis(EPMA),this paper investigates the genesis of tourmaline and discusses its implications for the evolutionary path of magmatic-hydrothermal fluids.Four distinct tourmaline generations are identified in the Baomai ore district,classified by mineral assemblages and host lithol-ogy as follows:① Nodular or vesicle-like tourmaline hosted in granodiorite porphyry(Tur-Ⅰ);② Quartz-tourma-line-sericite-molybdenite-pyrite veins within gneiss(Tur-Ⅱ);③ Quartz-tourmaline-sericite-pyrite veins hosted in granodiorite porphyry(Tur-Ⅲa);④ Quartz-tourmaline-sericite-pyrite veins within gneiss(Tur-Ⅲb).Tur-Ⅰ exhib-its extremely wide compositional variations,whereas Tur-Ⅱ and Tur-Ⅲ show relatively homogeneous chemical compositions.All four tourmaline types belong to the schorl-dravite series of the alkali tourmaline group.Their compositional variability is jointly controlled by multiple coupled substitution mechanisms,including Fe2+Mg-1/Fe3+Al-1,AlO(MgOH)-1,XvacancyAl(NaR2+)-1,Ca(Fe,Mg)(NaAl)-1.The four tourmaline generations in the Baomai ore district precipitated during the phyllic alteration stage,formed by variable degrees of mixing between early magmatic-hydrothermal fluids and formation fluids.Fe and Mn were predominantly sourced from magmas,while strata supplied substantial Mg,Ca,Fe,and Ti.The influx of formation fluids constitutes a key factor controlling Cu-Mo mineralization within the phyllic alteration zone of the Baomai deposit.关键词
斑岩成矿系统/电气石/岩浆热液演化/玉龙斑岩铜矿带/包买Key words
porphyry metallogenic system/tourmaline/evolution of magmatic hydrothermal fluid/Yulong porphyry copper metallogenic belt/Baomai分类
天文与地球科学引用本文复制引用
李淑霞,王琦,钟俊,白云,唐攀,王建皓,周敖日格勒,林彬,谢雨珂,孙杨,李文韬,邹兵..西藏包买铜钼矿床电气石矿物学特征及其对热液流体演化的指示[J].矿床地质,2026,45(4):841-867,27.基金项目
本文得到国家科技重大专项项目(编号:2025ZD1008805)、国家自然科学基金科研项目(编号:42572090、42272093、42230813)、中国地质科学院基本科研业务费专项经费项目(编号:JKYDM2025211)、西藏自治区科技计划项目(编号:XZ202401YD0006)、新一轮找矿突破战略行动科技支撑项目(编号:ZKKJ202429)和西藏自治区自然科学基金项目(编号:XZ202501ZR0041)联合资助 （编号:2025ZD1008805）
