完达山地块跃进山矽卡岩型铜金矿区酸性侵入岩锆石U-Pb年龄、地球化学特征及成因  

Zircon U-Pb age, geochemistry and genesis of acid intrusive rocks in the Yuejinshan skarn type copper-gold deposit, Wandashan block

作　　者：张国宾[1,2] 韩超[1] 杨言辰[3] 梁冰[2] 韦延兰 韩世炯[3] ZHANG Guobin;HAN Chao;YANG Yanchen;LIANG Bing;WEI Yanlan;HAN Shijiong(Department of Geology,Liaoning Technical University,Fuxin,123000,Liaoning,China;Department of Mechanics and Engineering Science,Liaoning Technical University,Fuxin,123000,Liaoning,China;;College of Earth Sciences,Jilin University,Changchun 130061,Jilin,China;;Institute of Karst Geology,CAGS,Guilin 541004,Guangxi,China)

机构地区：[1]辽宁工程技术大学地质工程系,辽宁阜新123000 [2]辽宁工程技术大学博士后流动站,辽宁阜新123000 [3]吉林大学地球科学学院,吉林长春130061 [4]中国地质科学院岩溶地质研究所,广西桂林541004

出　　处：《中国地质》2018年第5期977-991,共15页Geology in China

基　　金：中国地质调查局项目(1212011120342;1212010786005);辽宁省博士科研启动基金(201601370);辽宁工程技术大学第六批生产技术问题基金(20160084T)联合资助~~

摘　　要：跃进山小型矽卡岩型铜金矿床位于完达山地体西南部,矿体主要赋存于矽卡岩、花岗斑岩及其构造裂隙中,呈扁豆状或脉状。本文对矿区花岗闪长岩和花岗斑岩进行锆石U-Pb年代学和岩石地球化学研究,以了解矿床形成时代、成岩(矿)构造背景及矿床成因。测年结果表明,花岗斑岩和花岗闪长岩成岩年龄分别为(115.8±1.0)Ma和(126.9±1.7)Ma,铜金矿化时代与花岗斑岩成岩时代基本一致,为早白垩世晚期。岩石地球化学研究表明,花岗闪长岩属过铝质钙碱性系列岩石,稀土配分模式图为轻稀土富集,重稀土亏损,具较强的铕负异常,无铈异常,岩浆主要来源于壳源物质;花岗斑岩属过铝质钙碱性系列岩石,轻稀土富集,重稀土亏损,具弱铕负异常,无铈异常,相对富集大离子亲石元素(Rb、Ba、K、Sr)和不相容元素(U、Th),亏损高场强元素(Ta、Nb、P、Ti)和HREE,岩浆来源于壳幔物质混合源区,形成于碰撞后构造环境,成岩成矿作用与太平洋板块强烈俯冲作用后的伸展体制密切相关。Located in the southwest part of the Wandashan block,the Yuejinshan copper-gold deposit is a skarn type deposit,and its orebodies are hosted in skarns,granite porphyries and the tectonic fractures.The orebodies show lenticular or veined forms.LA ICP-MS zircon U-Pb dating and geochemical data are reported for granite porphyries and granodiorites in the Yuejinshan coppergold deposit in order to constrain its formation time,petrogenesis and the minerogenetic geotectonic background.The zircon LAICP-MS U-Pb age dating results show that the petrogenic ages of granite porphyries and granodiorites respectively are(115.8±1.0)Ma and(126.9±1.7)Ma respectively,and the copper-gold mineralization age is consistent with petrogenetic age of granite porphyry.Geochemical study indicates that the granodiorites are peraluminous calc-alkaline granite.The chondrite-normalized REE patterns of granodiorites display LREE enrichment and HREE depletion,with a distinct Eu anomaly,and their magma came from the lower crust.The granite porphyries belong to peraluminous calc-alkaline granite.The REE patterns show that granite porphyries exhibit pronounced LREE enrichment and HREE depletion,enrichment of large-ion lithosphile elements(Rb,Ba,K,Sr)and incompatible elements(U,Th),and depletion of high field-strength elements(Ta,Nb,P,Ti)and HREE.The magma of granite porphyries came from crust-mantle mixture,and the copper-gold deposit formed in the collision of post-collision extensional tectonic setting.The metallogenic materials formed intermediate-acid magma heat source,and magmatism and mineralization took place in the extensional tectonics after the Pacific plate subduction.

关 键 词：地质特征 地球化学特征 锆石U-PB年龄 矽卡岩 跃进山铜金矿 黑龙江省 

分 类 号：P597[天文地球—地球化学] P618.41[天文地球—地质学]