黑龙江省完达山地区金铜成矿作用时代、构造背景及物质源区  

Mineralization age, tectonic setting and material source of the gold-copper metallogeny in Wandashan area, Heilongjiang Province, NE China

作　　者：任云生 郝宇杰[2,3] 王崇一[2] 全传顺 李京谋 高煜 史雨凡 REN YunSheng;HAO YuJie;WANG ChongYi;QUAN ChuanShun;LI JingMou;GAO Yu;SHI YuFan(Institute of Disaster Prevention,Sanhe 065201,China;College of Earth Sciences,Jilin University,Changchun 130061,China;Key Laboratory of Mineral Resources Evaluation of Northeast Asia,Ministry of Natural Resources,Changchun 130061,China;First Geological Exploration Institute of Heilongjiang Province,Mudanjiang 157011,China)

机构地区：[1]防灾科技学院,三河065201 [2]吉林大学地球科学学院,长春130061 [3]自然资源部东北亚矿产资源评价重点实验室,长春130061 [4]黑龙江省第一地质勘察院,牡丹江157011

出　　处：《岩石学报》2020年第3期644-664,共21页Acta Petrologica Sinica

基　　金：国家重点研发计划项目(2017YFC0601304);自然资源部东北亚矿产资源评价重点实验室开放基金课题(DBY-KF-19-01)联合资助。

摘　　要：完达山地区位于中国东北部陆缘,区内已发现多个金、金铜矿床(点),集中形成于早白垩世。为确定区内早白垩世金铜成矿作用的类型、时代、构造背景及物质源区,选取258高地、358高地和跃进山等代表性矿床,在矿床学研究基础上,开展了主要成矿岩体的地质特征、地球化学特征和同位素年代学研究。结果表明,完达山地区发育矽卡岩型铜金矿(跃进山)、斑岩型铜矿(跃进山花岗斑岩体)、浅成低温热液型金矿(258高地)和中温热液脉型金矿(358高地)等四种类型金铜矿床;258高地闪长玢岩、358高地闪长玢岩和跃进山花岗斑岩的锆石U-Pb年龄分别为110.7±1.0Ma、108.4±0.9 Ma和101.9±1.1Ma;258高地闪长玢岩与358高地闪长玢岩锆石εHf(t)值(分别为+0.4^+10.3和+2.2^+7.1)、Hf二阶模式年龄(分别为0.51~1.15Ga和0.72~1.02Ga)及岩石地球化学特征显示其属于埃达克(质)岩石,形成于洋壳俯冲的构造背景;跃进山矿床花岗斑岩的锆石εHf(t)介于2.2~6.83,二阶段模式年龄tDM2介于725~1021Ma,具有典型Ⅰ型花岗岩地球化学特征,形成于古太平洋俯冲的构造背景下;岩石Sr-Nd-Pb同位素组成表明,随258高地闪长玢岩、358高地闪长玢岩和跃进山花岗斑岩的年龄变新,岩浆源区可能具有幔源向壳源过渡的趋势。结合区域构造背景演化认为,完达山地区早白垩世金铜成矿作用与古太平洋板块俯冲作用的演化过程具有明显的耦合关系。The Wandashan area is located in the continental margin of Northeast China(NE China),and tectonically belongs to the Wandashan Terrane,namely Nadanhada Terrane in the eastern segment of Xing'an-Mongolia Orogenic Belt.A number of Early Cretaceous gold and gold-copper deposits or ore occurrences have been discovered in this area.In order to determine their genetic types,mineralization ages,tectonic settings and material sources,some representative deposits have been studied on deposit geology,geochemistry and isotope dating,including No.258 Highland gold deposit,No.358 Highland gold deposit and Yuejinshan gold-copper deposit.Studies indicate that gold-copper deposits in Wandanshan area can be classified into four types,including skarn gold-copper deposit(Yuejinshan),porphyry copper deposit(copper-bearing Yuejinshan granite porphyry),epithermal gold deposit(No.258 Highland)and mesothermal gold deposit(No.358 Highland).LA-ICP-MS zircon U-Pb dating of diorite porphyrite in No.258 Highland and No.358 Highland,granite porphyry in Yuejinshan deposit show that their U-Pb ages are 110.7±1.0Ma,108.4±0.9Ma and 101.9±1.1Ma,respectively,implying they all emplaced at Early Cretaceous period.TheεHf(t)values of zircon grains from diorite porphyrite in both No.258 Highland and No.358 Highland are+0.4^+10.3 and+2.2^+7.1,and two-stage model age(tDM2)are 0.51~1.15Ga and 0.72~1.02Ga,which are concordant with geochemical characteristics of the adakite associated with the ocean-crust subduction.The Yuejinshan granite porphyry hasεHf(t)value of 2.2~6.83 and two-stage model age of 725~1021Ma,which indicate that it is of Ⅰ-type granite and resulted from the subduction of Pale-Pacific Plate.Sr-Nd-Pb compositions in different intrusions indicate that,from No.258 Highland diorite porphyrite,No.358 Highland diorite porphyrite to Yuejinshan granite porphyry,as emplacing from early to late,their dominant magma sources change from the mantle to the crust.The conclusion can be drawn in this paper that the Early Cretaceous gold-copper metall

关 键 词：完达山地体 金铜成矿作用 古太平洋板块俯冲 成矿时代 构造背景 物质源区 

分 类 号：P588.13[天文地球—岩石学] P597.3[天文地球—地质学]