大兴安岭北段富克山地区闪长玢岩锆石U-Pb定年和Hf同位素特征  

Zircon U-Pb dating and Hf isotope characteristics of the diorite porphyrite in the Fukeshan area,northern segment of the Great Xing an Range

作　　者：李焕纪 马双成 孙永刚 曲源[2] 靳皇玉 李斌[3] LI Huanji;MA Shuangcheng;SUN Yonggang;QU Yuan;JIN Huangyu;LI Bin(School of Resources and Civil Engineering,Suzhou University,Suzhou 234000,Anhui,China;Heilongjiang Geological Science Institute,Harbin 150036,Heilongjiang,China;Institute of Geological Survey of Jilin Province,Changchun 130102,Jilin,China)

机构地区：[1]宿州学院资源与土木工程学院,安徽宿州234000 [2]黑龙江省地质科学研究所,黑龙江哈尔滨150036 [3]吉林省地质调查院,吉林长春130102

出　　处：《吉林地质》2024年第3期12-19,共8页Jilin Geology

基　　金：宿州学院资助2024年省级大学生创新创业训练计划项目(项目名称:吉林省中部地区早中侏罗世花岗岩成因及构造背景研究,项目编号:S22410379180);安徽省教育厅高校自然科学重点科研项目(2024AH051826);宿州学院2022年博士科研启动基金项目(2022BSK009);宿州学院2023年博士后科研启动基金项目(2023BSH001)。

摘　　要：大兴安岭地区一直以来都是地质学领域中的研究热点,但对于大兴安岭中生代中性岩浆岩的研究相对缺少,缺乏精准的年代学及同位素数据。本文对大兴安岭北段富克山地区闪长玢岩进行系统的锆石U-Pb定年和Hf同位素特征研究,以期揭示富克山闪长玢岩的成岩时代和岩浆源区性质。富克山闪长玢岩LA-ICP-MS锆石U-Pb同位素测年结果显示,锆石的年龄加权平均值为(143.3±1.2)Ma(MSWD=0.28),属于早白垩世。结合前人研究结果,本文认为富克山地区至少存在3期岩浆侵入活动,分别为早侏罗世、晚侏罗世晚期和和早白垩世初期。富克山闪长玢岩锆石Hf同位素测试显示,锆石ε_(Hf)(t)值变化于-0.86~+1.26之间,二阶段模式年龄(T_(DM2))变化于1251~1117 Ma之间。结合前人研究成果讨论了闪长玢岩的岩浆源区,认为其岩浆源区为幔源岩浆,闪长玢岩母岩浆在上升过程中受到了地壳物质的混染。The Great Xing an Range has always been a research hotspot in the field of geology.However,there is a relative lack of research on the Mesozoic intermediate igneous rocks in this area remains,with a lack of precise chronological and isotopic data.In this article,the authors conducts systematic study on zircon U-Pb dating and Hf isotopic characteristics of diorite porphyrite in the Fukeshan area,the northern segment of the Great Xing an Range,aiming to reveal the diagenetic age and magma source properties of the Fukeshan diorite porphyrite.LA-ICP-MS zircon U-Pb dating results show that the weighted average age of the zircon is(143.3±1.2)Ma(MSWD=0.28),corresponding to the Early Cretaceous.Combined with previous research,the authors conclude that there were at least three periods of magmatic intrusion in the Fukeshan area,occurring during the Early Jurassic,Late Jurassic,and early stages of the Early Cretaceous.Zircon Hf isotope tests on the Fukeshan diorite porphyrite reveal that the zircon ε_(Hf)(t)values range from-0.86 to+1.26,with two-stage model ages(T_(DM2))ranging from 1251-1117 Ma.Based on previous research results,the magma source area of diorite porphyrite is discussed,and it is believed that the magma originated from the mantle.The mother magma of diorite porphyrite was contaminated by crustal materials during its ascent.

关 键 词：大兴安岭北段 锆石U-PB定年 HF同位素 闪长玢岩 岩浆源区 

分 类 号：P597.3[天文地球—地球化学]