多宝山铜钼金成矿带永新金矿床黄铁矿微量元素地球化学特征研究  

Geochemical characteristics of micro-elements in pyrite from Yongxin Gold Deposit in Duobaoshan Cu-Mo-Au metallogenic belt

作　　者：王卓 杨文鹏 符安宗 郑博 王涛 杨元江 赵忠海 Wang Zhuo;Yang Wenpeng;Fu Anzong;Zheng Bo;Wang Tao;Yang Yuanjiang;Zhao Zhonghai(Fifth Geological Exploration Institute of Heilongjiang Province;Natural Resources Survey Institute of Heilongjiang Province;Zhejiang Nonferrous Metals Geological Survey Institute;College of Mining,Liaoning Technical University)

机构地区：[1]黑龙江省第五地质勘查院 [2]黑龙江省自然资源调查院 [3]浙江有色地勘集团有限公司 [4]辽宁工程技术大学矿业学院

出　　处：《黄金》2024年第10期32-39,共8页Gold

基　　金：黑龙江省地质矿产科研项目(HKY2023-01);黑龙江省国土科研项目(201603)。

摘　　要：永新金矿床位于多宝山铜钼金成矿带南部,为了揭示矿床的成因和找矿信息,对载金矿物黄铁矿进行了稀土元素、微量元素和同位素等研究。研究结果表明,其化学成分特征为:稀土元素整体呈轻稀土元素富集、重稀土元素亏损,右倾型稀土元素配分模式,富集U、Th、Zr和Hf高场强元素,亏损Ba和Sr大离子亲石元素。w(Hf)/w(Sm)值、w(Nb)/w(La)值和w(Th)/w(La)值等反映成矿流体含Cl多于F;负Eu异常,无Ce异常,表明成矿流体形成于还原环境;w(Y)/w(Ho)值、w(Zr)/w(Hf)值和w(Nb)/w(Ta)值反映成矿过程没有混入外来热液物质,未发生交代作用,成矿流体与地幔和地壳关系密切;硫同位素特征表明成矿物质来源较深;w(Co)/w(Ni)值和w(Fe)/w(S+As)值等成因标型特征反映该矿床为中浅成火山热液成因。结合岩浆成因、构造背景、成岩-成矿时代、成矿作用、地球化学特征和本区域代表性金矿床主要特征认为,该矿床属斑岩成矿系统,为早白垩世形成的中浅成相对含Cl弱还原性金矿床。Yongxin Gold Deposit is located in the southern part of Duobaoshan Cu-Mo-Au metallogenic belt.To understand the genesis of the deposit and provide exploration insights,a study was conducted on the rare earth elements,micro-elements,and isotopic composition of gold-bearing pyrite.The results indicate that the chemical composition of pyrite shows enrichment in light REEs and depletion in heavy REEs,with a right-sloping REE distribution pattern.The pyrite is enriched in high-field-strength elements such as U,Th,Zr,and Hf,and depleted in large-ion lithophile elements like Ba and Sr.Ratios such as w(Hf)/w(Sm),w(Nb)/w(La),and w(Th)/w(La)suggest that the ore-forming fluid contained more Cl than F.A negative Eu anomaly and the absence of a Ce anomaly indicate that the ore-forming fluid formed under reducing conditions.Ratios like w(Y)/w(Ho),w(Zr)/w(Hf),and w(Nb)/w(Ta)suggest that the mineralization process did not involve external hydrothermal fluids,nor did metasomatism occur,with the ore-forming fluid closely related to both mantle and crustal sources.The sulfur isotopic characteristics indicate that the ore-forming materials originated from deeper sources.Genetic indicators such as w(Co)/w(Ni)and w(Fe)/w(S+As)suggest that the deposit is of a meso-epithermal volcanic hydrothermal origin.Based on the magmatic origin,tectonic setting,diagenesis-mineralization age,metallogenic process,geochemical characteristics,and the main features of representative gold deposits in the region,it is concluded that Yongxin Gold Deposit belongs to a porphyry metallogenic system,forming during the Early Cretaceous as a meso-epithermal,relatively Cl-rich,weakly reducing gold deposit.

关 键 词：黄铁矿 稀土元素 微量元素 矿床成因 永新金矿床 多宝山 铜钼金成矿带 斑岩成矿系统 

分 类 号：TD11[矿业工程—矿山地质测量] P618.51[天文地球—矿床学]