黑龙江多宝山铜矿区韧性剪切变形时代及其对铜矿化改造的约束  

The age of ductile shear deformation and its constraint on Cu mineralization transformation in Duobaoshan Cu deposit,Heilongjiang Province

作　　者：刘宝山[1] 张春鹏[1] 寇林林[1] 李成禄 韩仁萍[1] 王宇利[1] 杨宏智[1] LIU Baoshan;ZHANG Chunpeng;KOU Linlin;LI Chenglu;HAN Renping;WANG Yuli;YANG Hongzhi(Shenyang Center,China Geological Survey,Shenyang 110034,Liaoning,China;Research Institute of Regional Geological Survey of Heilongjiang,Harbin 150036,Heilongjiang,China)

机构地区：[1]中国地质调查局沈阳地质调查中心,辽宁沈阳110034 [2]黑龙江省自然资源调查院,黑龙江哈尔滨150036

出　　处：《地质通报》2024年第6期885-895,共11页Geological Bulletin of China

基　　金：国家重点研发计划课题《典型矿集区三维地质结构与矿体定位》(编号:2017YFC0601305);中国地质调查局项目《东北地区铜金稀有金属战略性矿产资源调查》(编号:DD20230028)。

摘　　要：黑龙江多宝山斑岩铜矿主要赋存于奥陶纪花岗闪长岩中,少量发育于奥陶纪花岗闪长斑岩及奥陶系多宝山组安山岩中,铜矿化以浸染状、细脉-浸染状为主。成矿过程经历了斑岩期、剪切变形期。矿区发育韧性剪切变形带,多宝山组、花岗闪长岩、花岗闪长斑岩、安山质凝灰角砾岩及矿体均发生了剪切变形作用,沿剪切面发育绢云母新生矿物。绢云母的坪年龄和正反等时线年龄分别为280.1±1.2 Ma和281.4±1.3 Ma、281.3±1.3 Ma,在误差范围内基本一致,限定矿区韧性剪切变形的时间为早二叠世(约280 Ma)。多宝山斑岩铜矿床主要成矿作用形成于斑岩期,成矿时代为早奥陶世(约475 Ma),早二叠世的韧性剪切变形作用对原生斑岩铜矿化进行了改造,使矿石的铜进一步富集,品位相对增高。The Duobaoshan porphyry Cu deposit is mainly found in Ordovician granodiorite,with minor occurrences in Ordovician granodiorite porphyry and andesite of the Duobaoshan Formation.The copper mineralization is primarily disseminated and levee-disseminated.The metallogenic process encompasses a porphyry stage and a shear deformation stage.A ductile shear deformation zone exists in the mining area,involving the Duobaoshan Formation,granodiorite,granodiorite porphyry,andesitic tuff breccia,and ore bodies.New sericite minerals develop along the shear plane.The plateau age,isochron ages and inverse isochron ages of sericite are 280.1±1.2 Ma,281.4±1.3 Ma,and 281.3±1.3 Ma,respectively,which are consistent within error ranges.The ductile shear deformation occurred during the Early Permian(about 280 Ma).The primary mineralization of the Duobaoshan porphyry copper deposit formed in the Early Ordovician(about 475 Ma).The Early Permian ductile shear deformation reshaped the original copper mineralization,further enriching the copper content and increasing the grade.

关 键 词：韧性剪切带 AR-AR年龄 斑岩型铜矿床 多宝山 黑龙江 矿产勘查工程 

分 类 号：P618.41[天文地球—矿床学]