粤北瑶岭钨矿区白云母花岗岩成因及与钨成矿关系  

Petrogenesis of the Yaoling Muscovite Granite and Its Genetic Relationship with Tungsten Mineralization

作　　者：姜海 李文铅[2] 赵葵东[3] JIANG Hai;LI Wenqian;ZHAO Kuidong(School of Tourism Management,Wuhan Business University,Wuhan 430056,Hubei,China;Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,Guangdong,China;School of Earth Resources,China University of Geosciences(Wuhan),Wuhan 430074,Hubei,China)

机构地区：[1]武汉商学院旅游管理学院,湖北武汉430056 [2]中国科学院广州地球化学研究所,广东广州510640 [3]中国地质大学(武汉)资源学院,湖北武汉430074

出　　处：《大地构造与成矿学》2025年第2期317-334,共18页Geotectonica et Metallogenia

基　　金：国家自然科学基金项目(91755208、41503043)资助。

摘　　要：粤北瑶岭钨矿是南岭地区典型的石英脉型钨矿床,其形成与隐伏花岗岩密切相关,但对隐伏花岗岩的成因及与其钨成矿的关系尚未深入探讨。本文对隐伏白云母花岗岩进行了锆石U-Pb年代学、全岩主量微量元素以及Sr-Nd-Hf-Pb同位素的详细研究。LA-ICP-MS锆石U-Pb定年结果显示,瑶岭白云母花岗岩的成岩年龄为161±2 Ma。该白云母花岗岩为高分异S型花岗岩,具有高硅、强过铝质、轻重稀土元素分馏不明显、强烈的Eu负异常,以及富集Rb、Th、U、Ta等元素,亏损Ba、Nb、Sr、Eu等元素的特征。瑶岭白云母花岗岩的ε_(Nd)(t)值和ε_(Hf)(t)值分别为−12.2~−11.1和−13.1~−10.7,Nd和Hf同位素的二阶段模式年龄分别为1.85~1.94 Ga和1.89~2.04 Ga。结合其较高的CaO/Na_(2)O值(>0.3),瑶岭白云母花岗岩可能是古元古代基底中的变杂砂岩在中上地壳深度部分熔融形成,并经历了矿物分离结晶作用。结合瑶岭白云母花岗岩与钨矿成岩和成矿在时间上的一致性和空间上的耦合性,以及白云母花岗岩和硫化物相似的Pb同位素组成,本文认为两者之间存在密切的时空和成因联系。瑶岭白云母花岗岩的富钨特征可能是岩浆源区、岩浆演化及熔体‒流体作用等因素共同作用的结果。The Yaoling tungsten deposit is located in northern Guangdong province and is a classic quartz vein-type tungsten deposit in the Nanling Range.Although tungsten mineralization in the Yaoling deposit exhibits spatial association with the concealed granite at depth,the petrogenesis of the concealed granite and its relationship with mineralization remain poorly constrained.This paper presents comprehensive zircon U-Pb geochronological,elemental geochemical,and Sr-Nd-Hf-Pb isotopic analyses of the concealed muscovite granite in the Yaoling deposit.Zircon U-Pb dating yielded a weighted mean age of 161±2 Ma for the Yaoling muscovite granite.The samples are highly silica and display strong peraluminous characteristics.They have unfractionated REE patterns and pronounced negative Eu anomalies,with enrichment of Rb,Th,U,and Ta and depletion of Ba,Nb,Sr,and U.These geochemical features suggest that the Yaoling muscovite granite is a highly fractionated S-type granite.They have negative whole-rockε_(Nd)(t)(−12.2 to−11.1)and zirconε_(Hf)(t)(−13.1 to−10.7)values with corresponding two-stage Nd and Hf model ages ranging from 1.85 Ga to 1.94 Ga and from 1.89 Ga to 2.04 Ga,respectively.Considering the relatively high CaO/Na_(2)O ratios(>0.3),we propose that the Yaoling muscovite granite was derived from partial melting of Paleoproterozoic greywacke rocks at the middle-upper crustal depths and modified by fractional crystallization.Based on previous studies and the spatiotemporal relationship between the ore veins and the concealed granite,as well as the comparable Pb isotopic compositions of the muscovite granite and sulfides,we suggest that the tungsten mineralization is genetically associated with the muscovite granite in the Yaoling deposit.It is likely that the remarkably high tungsten content in the Yaoling muscovite granite resulted from the combination of source enrichment and fractional crystallization coupled with melt-fluid interaction.

关 键 词：高分异S型花岗岩 锆石U-Pb定年 Sr-Nd-Hf-Pb同位素 瑶岭钨矿 

分 类 号：P581[天文地球—岩石学]