摘要
脉状金矿床在全球金矿资源中占据重要地位,探索新的勘查方法对于隐伏脉状金矿床的发现至关重要。近年来,矿物光谱测试和原位微区分析技术的快速发展极大地推动了蚀变矿物地球化学勘查在斑岩型和矽卡岩型矿床中的应用,但其在脉状金矿床中的研究仍需进一步加强。赵家金矿床位于胶东金矿集区焦家成矿带南段,其矿体以石英脉形式赋存于新太古界胶东群变质岩中,成矿过程可分为三个阶段:石英-钾长石阶段(Ⅰ)、石英-多金属硫化物-自然金阶段(Ⅱ,主成矿阶段)以及石英-方解石阶段(Ⅲ)。系统的短波红外(SWIR)光谱分析与岩相学观察表明,赵家金矿床主成矿阶段白云母族矿物较为发育,主要包括蒙脱石、白云母、伊利石、钠云母和多硅白云母。白云母族矿物的Al-OH吸收特征波长(Pos2200)和伊利石结晶度(IC值)展现出显著的示矿特征,在矿体位置分别表现为向长波长(Pos2200>2214 nm)和高值(IC>1.5)的明显偏移。此外,主成矿阶段黄铁矿微量元素也表现出一定的示矿特性,近矿端As(中值2.60μg/g)和Bi(中值0.920μg/g)含量显著高于远矿端蚀变岩中黄铁矿的对应元素含量(As:中值1.94μg/g;Bi:中值0.66μg/g),而Ni(矿体:中值99.8μg/g;远矿端:中值132μg/g)和Se(矿体:中值1.79μg/g;远矿端:中值3.18μg/g)含量则相对较低。白云母族矿物的光谱特征与黄铁矿微量元素的空间变化可能受到相分离过程中pH值和f_(O2)升高以及温度降低的共同影响,这也是赵家金矿床金沉淀的关键机制。本研究表明,白云母族矿物的SWIR光谱特征与黄铁矿微量元素地球化学特征在隐伏脉状金矿床勘探中具有重要的应用潜力,为脉状金矿床的成矿机制研究和勘查方法开发提供新视角。
Lode gold deposits constitute a vital component of global gold resources,and the development of innovative exploration methods is essential for identifying concealed orebodies.Recent advances in in-situ mineral microanalysis and spectral techniques have significantly advanced geochemical exploration targeting porphyry and skarn deposits;however,their application to lode gold deposits remains underexplored.The Zhaojia gold deposit,situated in the southern part of the Jiaojia metallogenic belt of the Jiaodong gold province,hosts quartz vein-type orebodies hosted in Neoarchean Jiaodong Group metamorphic rocks,with three alteration-mineralization stages:quartz-K-feldspar(Ⅰ),quartz-sericitesulfide-native gold(Ⅱ,main stage),and quartz-calcite(Ⅲ).Systematic short-wave infrared(SWIR)spectroscopy and petrographic analysis indicate that muscovite-group minerals,primarily including montmorillonite,muscovite,illite,paragonite,and phengite,are prominently developed during the main mineralization stage of the Zhaojia deposit.The Al-OH absorption wavelength(Pos2200)and IC values of muscovite-group minerals exhibit strong ore-indicative characteristics,with values shifting to longer wavelengths(Pos2200>2214 nm)and higher values(IC>1.5)near orebodies.Trace elements in pyrite from the main mineralization stage also exhibit ore-indicative trends:concentrations of As(median:2.60μg/g)and Bi(median:0.92μg/g)in the vicinity of orebodies are markedly higher than those in distal altered rocks(As:median 1.94μg/g;Bi:median 0.66μg/g),whereas Ni(orebody:median 99.8μg/g;distal:132μg/g)and Se(orebody:median 1.79μg/g;distal:3.18μg/g)contents are relatively lower.Spatial variations in the spectral features of muscovite-group minerals and pyrite trace elements may be influenced by increasing pH and oxygen fugacity,coupled with decreasing temperature during phase separation—A key mechanism driving gold precipitation.This study highlights the significant potential of SWIR spectral features of muscovite-group minerals and trace element geochemistry of pyrite for exploring concealed lode gold deposits,providing new insights into their mineralization mechanisms and prospecting strategies.
作者
赵红涛
张宇
许延波
邵拥军
郝珈瑶
冯雨周
陈晓燕
赵廉洁
沈鸿杰
廖俊弘
ZHAO Hongtao;ZHANG Yu;XU Yanbo;SHAO Yongjun;HAO Jiayao;FENG Yuzhou;CHEN Xiaoyan;ZHAO Lianjie;SHEN Hongjie;LIAO Junhong(MOE Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring(Central South University),Changsha 410083,Hunan,China;School of Geosciences and Info-Physics,Central South University,Changsha 410083,Hunan,China;Shandong Gold Geology Minerals Survey Go.,Ltd.,Laizhou 261400,Shandong,China;Department of Geological Sciences,University of Saskatchewan,Saskatoon SK S7N 5E2,Canada;School of Resources and Environmental Engineering,Shandong University of Technology,Zibo 255049,Shandong,China)
出处
《大地构造与成矿学》
北大核心
2026年第1期58-75,共18页
Geotectonica et Metallogenia
基金
国家重点研发计划项目(2022YFC2903601)
中南大学中央高校基本科研业务费专项资金(2023ZZTS0980)
国家留学基金委项目(202406370277)联合资助。
关键词
黄铁矿
白云母族矿物
勘查标识
赵家金矿床
胶东金矿
pyrite
muscovite-group minerals
exploration identification
Zhaojia gold deposit
Jiaodong gold province
