吉林延边和龙地区华集岭钼矿床成矿时代、成矿流体特征及成矿物质来源  

Mineralization Age, Fluid Properties and Sources of Ore-FormingMaterials for Huajiling Molybdenum Deposit in HelongArea of Yanbian, Jilin Province

作　　者：张雅静[1] 刘万臻 卢禹含 聂喜涛 张佳楠[1] Zhang Yajing;Liu Wanzhen;Lu Yuhan;Nie Xitao;Zhang Jianan(College of Earth Sciences,Jilin University,Changchun 130061,China;The Fifth Geological Survey Institute of Jilin Province,Changchun 130103,China;Jilin Nonferrous Metals Geological Exploration Bureau Research Institute,Changchun 130012,China;School of Geomatics and Prospecting Engineering,Jilin Jianzhu University,Changchun 130119,China)

机构地区：[1]吉林大学地球科学学院,长春130061 [2]吉林省第五地质调查所,长春130103 [3]吉林省有色金属地质勘查局研究所,长春130012 [4]吉林建筑大学测绘与勘查工程学院,长春130119

出　　处：《吉林大学学报（地球科学版）》2024年第6期2154-2170,共17页Journal of Jilin University：Earth Science Edition

基　　金：国家重点研发计划项目(2023YFC2906903);吉林省地勘基金项目([2016]地勘20-15)。

摘　　要：华集岭钼矿床位于华北克拉通北缘东段,是近年来新发现的钼矿床。该矿床中矿体呈NNW向展布,倾向西,倾角为45°~50°,主要赋存在花岗斑岩及花岗闪长岩中。矿石类型主要有细脉状和浸染状两种,矿石矿物以辉钼矿、磁铁矿和黄铁矿为主,少量赤铁矿和钼华,发育云英岩化、钾化、硅化、绿泥石化和碳酸盐化等围岩蚀变。为了确定成矿时代、成矿流体特征及成矿物质来源,本文对华集岭钼矿床中的辉钼矿进行了Re-Os测年、流体包裹体测温和H-O-S-Pb同位素分析。结果显示:华集岭钼矿床中辉钼矿Re-Os年龄为(178.0±1.1)Ma,处于古太平洋板块向欧亚板块俯冲的构造环境。成矿流体由早期的高温、中低盐度、中低密度向晚期的中低温、中低盐度、中等密度演化。石英的δ^(18)O_(H_(2)O)值为-2.1‰~2.6‰,δD_(V-SMOW)值为-115.8‰~-109.7‰,成矿流体显示岩浆水与大气降水混合的特征;辉钼矿w(Re)值为19.564×10^(-6)~23.128×10^(-6),成矿物质具有壳幔混合的特征;黄铁矿的δ^(34) S_(V-CDT)值为1.9‰~4.2‰,均值为2.7‰,表明硫主要来自幔源;黄铁矿的^(206)Pb/^(204)Pb、^(207)Pb/^(204)Pb、^(208)Pb/^(204)Pb值分别为17.865~18.279、15.546~15.611、38.011~38.486,进一步表明成矿物质具有壳幔混合的特征。The Huajiling molybdenite deposit is a newly discovered molybdenum deposit located in the eastern section of the northern margin of the North China craton.It features an ore body oriented in NNW direction,dipping at 45°to 50°,surrounded by wall rocks of granite porphyry and granodiorite.The ore types include fine veinlet ores and disseminated ores,primarily consisting of molybdenite,magnetite and pyrite,with minor amounts of hematite.The alteration of wall rock involves dolomitization,potassium mineralization,silicification,chloritization,and carbonate mineralization.In order to determine the mineralization age,fluid properties and sources of ore-forming materials,this study conducted molybdenite Re-Os dating,fluid inclusion temperature measurements,and H-O-S-Pb isotope analysis on Huajiling deposit.Results indicate that the Re Os age of Huajiling molybdenum deposit is(178.0±1.1)Ma,formed in a tectonic environment where the ancient Pacific plate subducted beneath the Eurasian plate.The ore-forming fluid evolved from high temperature,low to medium salinity,and low to medium density to low temperature,low to medium salinity,and medium density.Theδ^(18)OH _(2)O values of quartz range from-2.1‰to 2.6‰,andδD V SMOW values range from-115.8‰to-109.7‰,indicating contributions from both magma water and atmospheric precipitation.The w(Re)values of molybdenite range from 19.564×10^(-6) to 23.128×10^(-6),exhibiting a crust-mantle mixed source.Theδ^(34) S V CDT values of pyrite(1.9‰4.2‰,with an average of 2.7‰)indicate that the sulfur mainly originates from the mantle.Additionally,the 206 Pb/204 Pb,207 Pb/204 Pb,208 Pb/204 Pb values of pyrite range from 17.86518.279,15.54615.611,and 38.01138.486,respectively,further supporting the crust-mantle mixed source hypothesis for ore-forming materials.

关 键 词：辉钼矿 RE-OS测年 成矿流体 流体包裹体 同位素 成矿物质 华集岭钼矿床 

分 类 号：P618.2[天文地球—矿床学] P611[天文地球—地质学]