华北克拉通北缘中段赤峰撰山子矿区石炭纪-二叠纪侵入岩年代学和地球化学:对古亚洲洋构造演化的制约  

Chronology and geochemistry of Carboniferous-Permian intrusive rocks in Zhuanshanzi mining area,Chifeng,middle part of the northern margin of the North China Craton:Constraints on the tectonic evolution of the Paleo-Asian Ocean

作　　者：杨帆 姜艳艳[3] 陈井胜 韩兴[1] YANG Fan;JIANG YanYan;CHEN JingSheng;HAN Xing(College of Resources and Enviroment,Jilin Agricultural University,Changchun 130118,China;Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences,Haerbin 150001,China;Songliao River Basin Water and Soil Conservation Monitoring Center Station of Songliao Water Conservancy Commission,Changchun 130061,China;Shenyang Center of Geological Survey,China Geological Survey,Shengyang 110034,China)

机构地区：[1]吉林农业大学资源与环境学院,长春130118 [2]中国科学院东北地理与农业生态研究所,哈尔滨150001 [3]松辽水利委员会松辽流域水土保持监测中心,长春130061 [4]中国地质调查局沈阳地质调查中心,沈阳110034

出　　处：《岩石学报》2022年第8期2467-2488,共22页Acta Petrologica Sinica

基　　金：科技部重点研发项目(2021YFD1500700、2021YFD1500804);中国地质调查局项目(DD20221632-02)联合资助。

摘　　要：本文对华北克拉通北缘中段赤峰撰山子矿区二长闪长岩、花岗(斑)岩等进行了岩相学、地球化学、锆石U-Pb定年以及Hf同位素研究,以期对古亚洲洋演化形成制约。锆石U-Pb定年显示,二长闪长岩和花岗岩形成于早石炭世(341.0±2.2Ma、324.1±4.3Ma),花岗斑岩形成于晚二叠世(252.8±3.2Ma、252.0±1.5Ma)。岩石地球化学及Hf同位素表明,二长闪长岩为高钾钙碱性I型花岗岩,形成于火山弧环境,其源区可能是俯冲板片脱水交代的地幔楔部分熔融产生玄武质岩浆上涌,导致新生地壳物质的部分熔融,并有部分玄武质岩浆加入形成的产物;花岗岩及花岗斑岩均为高钾钙碱性A型花岗岩,花岗岩形成于火山弧环境,花岗斑岩形成于造山后伸展环境,二者皆为新生地壳部分熔融的产物。综合前人研究认为,早石炭世-晚二叠世,研究区经历了古亚洲洋俯冲、弧-陆碰撞以及造山后伸展等阶段。In this paper,the lithography,geochemistry,zircon U-Pb dating and Hf isotopes of monzodiorite and granite in Zhuanshanzi mining area,Chifeng,in the middle part of the northern margin of the North China Craton are studied in order to restrict the evolution of the Paleo-Asian Ocean.Zircon U-Pb dating shows that the monzodiorite and granite were formed in the Early Carboniferous(341.0±2.2 Ma,324.1±4.3 Ma)and the granitic porphyry in the Late Permian(252.8±3.2 Ma,252.0±1.5 Ma).Geochemistry and Hf isotopes indicate that the monzodiorite is a high-K calc-alkaline I-type granite.It was formed in a volcanic arc environment.The source may be basaltic magma upwelling caused by partial melting of mantle wedge metasomatized by dehydration of subduction plate,leading to partial melting of new crustal material.At the same time,some basaltic magma was added.The granite and granitic porphyry are high-K calc-alkaline A-type granites.Granite is formed in volcanic arc environment and granitic porphyry in post-orogenic extensional environment.They are products of partial melting of the new crust.Combining with previous studies,we concluded that the study area experienced subduction,arc-continent collision and post-orogenic extension of Paleo-Asian Ocean from the Early Carboniferous to the Late Permian.

关 键 词：华北克拉通 赤峰地区 古亚洲洋 锆石U-PB 地球化学 

分 类 号：P588.122[天文地球—岩石学] P597.3[天文地球—地质学]