粤北良源铌钽铷钨矿床地质、成岩成矿时代与成矿模式  

Deposit geology,geochronology and metallogenic model of Liangyuan Nb-Ta-Rb-W deposit in northern Guangdong Province

作　　者：范飞鹏[1,2] 肖惠良 陈乐柱[1] 李海立[1,2] 鲍晓明[1] FAN FeiPeng;XIAO HuiLiang;CHEN LeZhu;LI HaiLi;BAO XiaoMing(Nanjing Center,China Geological Survey,Nanjing 210016,China;Research Centre for Pacific Rim Strategic Mineral Resources,Nanjing 210016,China)

机构地区：[1]中国地质调查局南京地质调查中心,南京210016 [2]环太平洋战略矿产资源联合研究中心,南京210016

出　　处：《岩石学报》2022年第2期393-410,共18页Acta Petrologica Sinica

基　　金：中国地质调查局工作项目(DD20221688、DD20190153、1212011120811、1212010533003);江苏省面上基金(BK20191132)联合资助.

摘　　要：良源铌钽铷钨矿床位于南岭东西向构造岩浆带与武夷山北东向构造带交汇部位。良源铌钽铷钨矿床是粤北地区近年在石英型钨矿、云英岩型铌钽铷钨矿和花岗岩型铌钽铷多金属矿勘查评价取得最重要突破矿区,新发现铌钽铷钨矿体4条,共、伴生Nb_(2)O_(5)资源量3425.72吨,平均品位0.0108%;Ta_(2)O_(5)资源量1428.99吨,平均品位0.00449%;WO_(3)资源量8205.14吨,平均品位0.25%;伴生Rb_(2)O资源量61398.73吨,平均品位0.0987%,矿区具有大型-超大型资源潜力。良源铌钽铷钨矿床矿化特征为浅部石英脉型钨多金属矿体和云英岩型铌钽铷钨矿体+深部花岗岩型铌钽铷矿体,与以往的石英脉型钨矿“五层楼”+“地下室”成矿特征明显不同,因此对其开展成矿年代学、元素富集成矿规律和成矿模式研究具有重要意义。本文在对矿床成矿地质特征研究基础上,开展了详细的矿物学和年代学研究,应用锆石SHRIMP U-Pb法获得云英岩成岩时代为163.6~159.2Ma;黑云母花岗岩锆石^(206)Pb/^(238)U加权平均年龄为163.0±1.6Ma.应用白云母^(40)Ar-^(39)Ar等时线法获得云英岩型矿体成矿时代为166.4±1.1Ma,白云母花岗岩型矿体成矿时代为168.7±1.2Ma。研究表明,良源铌钽铷钨矿床形成于中-晚侏罗世,是华南东部中生代大规模花岗质岩浆活动与铌钽铷多金属成矿作用开始的产物,其成矿作用是花岗质岩浆高度分异形成的产物,成岩与成矿时间基本一致。浅部为石英脉型钨矿和云英岩型钨锡铌钽铷矿化,岩体接触带为云英岩型钨铌钽铷矿体,深部为高分异花岗岩型铌钽铷矿体。根据以上研究成果,本文建立了良源铌钽铷钨矿床成矿模式,对南岭地区石英脉型-云英岩型-花岗岩型稀有金属成矿理论具有一定的拓展意义,对该地区下一步勘查工作部署具有重要实践意义。The Liangyuan Nb-Ta-Rb-W deposit is located at the intersection of the NE-trending of Wuyishan and the E-W-trending tectonic-magma belt in the eastern Nanling region.The main types of mineralization are quartz vein type W ore bodies,greisen type Nb-Ta-Rb-W ore bodies,and granite-type Nb-Ta-Rb ore bodies in the Liangyuan Nb-Ta-Rb-W deposit.Four Nb-Ta-Rb-W ore bodies have been newly discovered,which have reserve more than 3425.72 tons Nb_(2)O_(5) with an average grade of 0.0108%,1428.99 tons Ta_(2)O_(5) with an average grade of 0.00449%,8205.14 tons WO_(3) with an average grade of 0.25%,and 61398.73 tons Rb_(2)O with an average grade of 0.0987%.The Liangyuan Nb-Ta-Rb-W deposit has large scale-super large resource potential in deep.The Liangyuan Nb-Ta-Rb-W deposit is characterized by quartz vein type W-polymetallic ore-bodies and greisen type Nb-Ta-Rb-W ore bodies in the shallow,and granite-type Nb-Ta-Rb ore bodies in the deep.It has important implications to study on timing of rocks and ores,elements enrichment,metallogenic regularity and metallogenic model because of different from the classic“Five levels+Basement”of W ore-bodies.In this paper,based on the detailed deposit geology,elements enrichment,metallogenic regularity and metallochronology were studied.Using zircon SHRIMP U-Pb dating method,we obtained the age of greisen is ca.163.6~159.2Ma.The zircons of biotite granite had ^(206)Pb/^(238)U weighted average age of 163.0±1.6Ma.Using the ^(40)Ar-^(39)Ar isochron method of muscovite,we obtained the ore-forming age of greisen type Nb-Ta-Rb-W ore bodies and muscovite granite-type Nb-Ta-Rb ore bodies are ca.166.4±1.1Ma and ca.168.7±1.2Ma,respectively.This study shows that the Liangyuan Nb-Ta-Rb-W deposit was formed in the Middle and Late Jurassic,resulting in the products of the beginning from the large-scale highly differentiated granitic magmatism and Nb-Ta-Rb-W mineralization of South China in Mesozoic,and the Nb-Ta-Rb-W mineralization time is consistent with the intrusion of granitic magma.The quartz v

关 键 词：锆石SHRIMP U-Pb 白云母^(40)Ar-^(39)Ar等时线年龄 成矿模式 良源铌钽铷钨矿 

分 类 号：P597.3[天文地球—地球化学] P618.7[天文地球—地质学]