摘要
香炉山超大型钨矿床位于世界级江南钨成矿带赣西北段,属于典型的矽卡岩型钨矿床,并伴随有角岩型和云英岩型白钨矿化。钨矿体主要分布于黑云母花岗岩与含碳泥质灰岩、灰质泥岩、含碳质页岩及硅质岩等接触带附近,受NE向、EW向倾伏背斜控制。近年来,在香炉山老矿区外围陆续发现形坪、张天罗和大岩下三个新矿段,累计新增WO_(3)资源量8.12万吨。新发现的钨矿体与矿区隐伏黑云母花岗岩在空间上关系密切。然而,目前关于这类隐伏黑云母花岗岩的成岩时代及其与已报道的香炉山矿段黑云母花岗岩之间的成因联系,尚缺乏深入研究。本文通过对香炉山钨矿床3件隐伏黑云母花岗岩进行锆石和独居石U-Pb同位素定年,获得^(206)Pb/^(238)U加权平均年龄分别为127.2±2.0 Ma、125.4±0.9 Ma、125.5±2.1 Ma和125.4±0.9 Ma,与矿区已报道的黑云母花岗岩成岩年龄在误差范围内一致,表明它们均属于中国东部早白垩世构造-岩浆活动的产物。此外,香炉山隐伏黑云母花岗岩具有高硅(SiO_(2)=68.40%~76.88%)、富碱(Na_(2)O+K_(2)O=7.61%~9.27%)、弱-强过铝质(A/CNK=0.96~1.18)的特点,较低的Fe_(2)O_(3)/FeO值(0.05~0.41),并富集K、Rb、Th、U、Pb,亏损Ba、Sr、P、Ti等元素,球粒陨石标准化稀土元素配分曲线呈右倾形态,且具Eu负异常(Eu/Eu*=0.11~0.53)。结合前人研究,香炉山隐伏黑云母花岗岩为高分异还原性含钨花岗岩,具备形成大型-超大型钨矿床的成矿潜力。
The giant Xianglushan tungsten deposit is located the Jiangnan Tungsten Metallogenic Belt in northwestern Jiangxi Province.It represents a typical skarn-type tungsten deposit associated with hornfels-and greisen-type scheelite mineralization.The ore bodies are primarily hosted in the contact zone between biotite granite and carbonaceous argillite,calcareous mudstone,carbonaceous shale,and siliceous rock,and are controlled by the NE-EW-dipping anticline.In recent years,new ore sections(including Xingping,ZhangTianluo,and Dayanxia)have been discovered on the periphery of the Xianglushan mining area,adding 81200 tons of WO_(3)resources.These newly identified ore bodies exhibit spatial association with a concealed biotite granite.However,detailed research on the crystallization age of this concealed granite and its genetic relationship with the known biotite granite in the Xianglushan mining area remains insufficient.In this study,zircon and monazite U-Pb isotopic dating was conducted on three concealed biotite granite samples from the Xianglushan tungsten deposit.The obtained^(206)Pb/^(238)U weighted average ages are 127.2±2.0 Ma,125.4±0.9 Ma,125.5±2.1 Ma,and 125.4±0.9 Ma,respectively,which are consistent with previously reported zircon U-Pb ages for the biotite granite in the Xianglushan mine within analytical uncertainties.These ages correspond to the Early Cretaceous tectonic-magmatic activity in eastern China.Additionally,the concealed biotite granites are characterized by high silica content(SiO_(2)=68.40%-76.88%),alkali enrichment(Na_(2)O+K_(2)O=7.61%-9.27%),weak to strong peraluminous features(A/CNK=0.96-1.18),and low Fe_(2)O_(3)/FeO ratios(0.05-0.41).They are enriched in K,Rb,Th,U,and Pb but depleted in Ba,Sr,P,and Ti.The chondrite-normalized REE patterns exhibit a right-dipping trend with a pronounced negative Eu anomaly(Eu/Eu*=0.11-0.53).These geological and geochemical signatures suggest that the concealed biotite granite in the Xianglushan tungsten deposit is a highly evolved,reduced W-bearing granite with excellent potential for forming large to giant tungsten deposits.
作者
汪国华
周腾
高剑峰
张世涛
张勇
高任
张浩
温润涛
陈天迪
程冰冰
WANG Guohua;ZHOU Teng;GAO Jianfeng;ZHANG Shitao;ZHANG Yong;GAO Ren;ZHANG Hao;WEN Runtao;CHEN Tiandi;CHENG Bingbing(The Second Geological Brigade of Jiangxi Provincial Geological Bureau,Jiujiang 332000,Jiangxi,China;State Key Laboratory of Ore Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,Guizhou,China;State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang 332400,Jiangxi,China;Xianglushan Tungsten Industry Co.,LTD in Jiangxi Province,Jiujiang 332000,Jiangxi,China)
出处
《大地构造与成矿学》
北大核心
2025年第4期989-1002,I0046-I0050,共19页
Geotectonica et Metallogenia
基金
国家重点研发计划项目(2023YFC2906803)
国家自然科学基金项目(42025301、42062006)联合资助。
