黑龙江东部那丹哈达地体燕山期金铜成矿系统——中生代岩浆作用与成矿背景  

Yanshanian gold-copper metallogenic system of Nadanhada terrane in eastern Heilongjiang--Mesozoic magmatism and metallogenic background

作　　者：张国宾[1] 何云龙 杨言辰[2] 孔金贵 冯玥 陈兴凯 ZHANG Guobin;HE Yunlong;YANG Yanchen;KONG Jingui;FENG Yue;CHEN Xingkai(School of mines,Liaoning Technical University,Fuxin,Liaoning,123000;College of Earth Sciences,Jilin University,Changchun,130061;Jiangsu Coal Geophysical Prospecting and Surveying Team,Nanjing,210000)

机构地区：[1]辽宁工程技术大学矿业学院,辽宁阜新123000 [2]吉林大学地球科学学院,长春130061 [3]江苏煤炭地质物测队,南京210000

出　　处：《地质论评》2023年第5期1763-1794,共32页Geological Review

基　　金：中国地质调查局项目(编号:1212011120342);辽宁省科技厅面上基金资助项目(编号:20170540428、201601370);辽宁省教育厅面上基金资助项目(编号:LJ2019JL027)的成果。

摘　　要：黑龙江东部那丹哈达地体位于锡霍特—阿林造山带中部西缘,中生代以来发生了剧烈的构造—岩浆—成矿作用,发育有热泉型、火山热液型、浅成低温热液型以及矽卡岩型等铜金矿床。笔者等在详细的野外地质调查基础上,对四平山、先锋北山、258高地和跃进山4个典型矿床的成矿岩体进行主量元素、稀土、微量元素地球化学特征分析以及锆石U-Pb年代学研究,旨在探讨研究区燕山期铜金成矿构造背景与成矿模式。研究结果表明,四平山金矿床、先锋北山金矿床、258高地金矿床和跃进山铜金矿床成矿岩体的LA-ICP-MS锆石U-Pb年龄分别为122.5±1.1 Ma、117.0±0.4 Ma、116.9±0.8 Ma和115.7±1.1 Ma,矿床成矿时代属于早白垩世晚期。4个矿床的成矿岩体具有相似的岩石地球化学特征,属于中分异I型花岗岩,岩浆来源于地壳物质部分熔融源区,形成于碰撞后构造背景。结合矿床地质背景、锆石U-Pb年代学特征、地球化学特征以及区域构造演化,笔者等认为四平山金矿床、先锋北山金矿床、258高地金矿床和跃进山铜金矿床的成矿时代基本一致,成因均与燕山期中酸性岩浆相关,属于同一成矿系列,铜金成矿作用与古太平洋板块俯冲作用密切相关。Objectives and Methods:The Nadanhada terrane is located at western margin of the central Sikhote—Alin orogenic belt.Vigorous tectonic—magmatic—mineralization has occurred since the Mesozoic,forming hot spring type,volcanic—hydrothermal type,epithermal low temperature hydrothermal type and skarn type copper—gold deposits.In this paper,based on detailed field geological investigations,geochemical characterization of major elements,rare earths and trace elements as well as zircon U-Pb chronology of four typical deposits in Sipingshan,Xianfengbeishan,258 highland and Yuejinshan were carried out,aiming to explore the tectonic background and metallogenic mode of Yanshan period copper—gold mineralization in the study area.Results:The results show that the LA-ICP-MS zircon U-Pb ages of the ore-forming rocks of Sipingshan gold deposit,Xianfengbeishan gold deposit,258 highland gold deposit and Yuejinshan copper—gold deposit are 122.5±1.1 Ma,117.0±0.4 Ma,116.9±0.8 Ma and 115.7±1.1 Ma,respectively.The mineralization age of these deposits belongs to the late Early Cretaceous.The ore-forming rocks of the four deposits have similar lithogeochemical characteristics and belong to medium divergent I-type granites,with magma originating from partial melt source areas of crustal material and formed in a post-collisional tectonic setting.Conclusions:Combined with the geological setting of the deposit,zircon U-Pb chronological characteristics,petrochemical characteristics and regional tectonic evolution,this paper concludes that the metallogenic age of the Sipingshan gold deposit,Xianfengbeishan gold deposit,258 highland gold deposit and Yuejinshan copper—gold deposit are basically the same,and their genesis is related to the Yanshanian intermediate—acid magma,belonging to the same metallogenic series.Copper—gold mineralization is closely related to the subduction of the Pale-Pacific plate.

关 键 词：锆石U-Pb同位素 岩石地球化学 成矿构造背景 成矿模式 那丹哈达地体 

分 类 号：P618.41[天文地球—矿床学] P618.51[天文地球—地质学]