摘要
江西省香炉山钨矿是江南古陆斑岩-矽卡岩钨多金属成矿带内具有代表性的早白垩世矽卡岩型钨矿床。矿床的WO3储量约为22万t,平均品位约为0.641%。矿床的矿体以似层状和透镜状产出于燕山期黑云母花岗岩和寒武系杨柳岗组泥灰岩的接触带。本文在详细厘定成矿阶段矿物组合的基础上,对不同阶段产出的不同世代的白钨矿开展了原位LA-ICP-MS微量元素的系统测试。香炉山钨矿床可以划分为四个成矿阶段:矽卡岩阶段、退化蚀变阶段、石英-硫化物-白钨矿阶段和方解石-萤石阶段。根据各阶段矿物组合及与白钨矿共生关系,本次研究划分出四个阶段六个世代的白钨矿,分别为阶段Ⅰ白钨矿(产于云英岩中)、阶段Ⅱa和阶段Ⅱb白钨矿(产于退化蚀变岩)、阶段Ⅲa和阶段Ⅲb白钨矿(产于硫化物条带,Ⅲa为白钨矿核部,Ⅲb为白钨矿边部)和阶段Ⅳ白钨矿(产于石英-硫化物-白钨矿脉)。白钨矿的球粒陨石标准化稀土元素配分图有下凹型(阶段Ⅰ、阶段Ⅱa、阶段Ⅲb)、右倾型(阶段Ⅳ)和下凹右倾型(阶段Ⅲa)。各阶段白钨矿的微量元素特征表明,香炉山钨矿床白钨矿的∑REE含量高于世界上绝大部分脉状金和钨矿床,也高于我国华南地区钨多金属矿床。白钨矿中REE3+与Ca2+主要的替代机制为3Ca2+=2REE3++Ca(为一个Ca空位)。白钨矿的REE和Eu异常由流体决定,可以用来示踪流体的演化过程,Eu的活动主要以Eu2+为主。香炉山钨矿床为还原性矿床,不同阶段白钨矿中Mo等元素含量的变化指示流体演化各阶段的还原性强弱有波动。不同阶段白钨矿的稀土和微量元素特征有较大变化。香炉山白钨矿稀土元素的超常富集原因和机制仍有待进一步研究和探讨。
The Xianglushan tungsten deposit is a large tonnage deposit with a resource of 0.22Mt@0.641%WO_(3).It is a typical skarn tungsten deposit formed in Early Cretaceous in the Jiangnan porphyry-skarn W polymetallic belt.Orebodies occur in the contact zone between the Yanshanian biotite granite and the Cambrian Yangliugang Formation which composed as muddy limestone in the form of stratiform and lenticulum.Based on detailed division of metallogenic stages and mineralogical work,trace elements of scheelite of different generations produced from different stages have been systematically studied via in situ LA-ICP-MS.Metallogenic stages of Xianglushan tungsten deposit can be divided into four stages:skarn stage,skarn retrograde stage,quartz-sulfide-scheelite stage and calcite-fluorite stage.According to mineral assemblage and paragenesis relationship with scheelite in each stage,four stages and six generations of scheelite have been divided,which are stageⅠscheelite(in greisen),stageⅡa and stageⅡb scheelite(in retrograde rock),stageⅢa and stageⅢb scheelite(in sulfide band,Ⅲa is the core of scheelite,Ⅲb is the edge of scheelite)and stageⅣscheelite(in quartz-sulfide-scheelite vein).The chondrite-normalized REE distribution patterns for different types of scheelites are:concave(stageⅠ,Ⅱa,Ⅲb),shallow negative(stageⅣ)and shallow negative concave(stageⅢa).The trace element characteristics of scheelite at each stage indicate that,content of rare earth elements in scheelite of Xianglushan tungsten deposit is higher than that of most gold and tungsten deposits in the world,and it is also higher than that of scheelite of other tungsten-polymetallic deposits in South China.The main substitution mechanism of REE 3+and Ca^(2+)in scheelite is 3Ca^(2+)=2REE^(3+)+□Ca(□is a Ca vacancy).REE and Eu anomalies of scheelite are mainly determined by fluids and can be used to trace the evolution of fluids.Eu act mainly as Eu^(2+).Xianglushan tungsten deposit is a reduced deposit,and the variation of Mo in different
作者
戴盼
毛景文
吴胜华
李超
程冰冰
高涛
倪洪
刘琦
DAI Pan;MAO JingWen;WU ShengHua;LI Chao;CHENG BingBing;GAO Tao;NI Hong;LIU Qi(School of Resources and Environmental Engineering,Shandong University of Technology,Zibo 255000,China;China University of Geosciences,Beijing 100083,China;MNR Key Laboratory of Metallogeny and Mineral Assessment,Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037,China;National Research Center for Geoanalysis,Beijing 100037,China;Jiangxi Xiushui Xianglushan Tungsten Industry Limited Liability Company,Jiujiang 332400,China)
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2023年第6期1674-1692,共19页
Acta Petrologica Sinica
基金
山东省自然科学基金项目(ZR2020QD031、ZR2018QD002)
国家自然科学基金项目(41820104010、42002099)联合资助。
关键词
香炉山
矽卡岩
白钨矿
稀土元素
富集
流体
Xianglushan
Skarn
Scheelite
Rare earth elements
Enrichment
Fluid
