山西羊投崖岩体花岗斑岩锆石U-Pb年龄、Hf同位素组成和地球化学特征及其地质意义  

Zircon U-Pb age,Hf isotopic composition and geochemical characteristics of the Yangtouya intrusion in Shanxi Province and their geological significances

作　　者：叶枫 董国臣[2] 董晶[3] 任建勋 李松峰 任宏艳 张兆瑞 YE Feng;DONG Guo-chen;DONG Jing;REN Jian-xun;LI Song-feng;REN Hong-yan;ZHANG Zhao-rui(Department of Resources and Safety Engineering,Shanxi Engineering Vocational College,Taiyuan 030009,China;School of Geosciences and Resources,China University of Geosciences(Bejing),Beijing 100083,China;Shanxi School of Economic and Trade,Taiyuan 030006,China;No.146 Team,Gansu Bureau of Coal Geology,Pingliang,Gansu 744000,China)

机构地区：[1]山西工程职业学院资源与安全工程系,太原030009 [2]中国地质大学(北京)地球科学与资源学院,北京100083 [3]山西省经贸学校,太原030006 [4]甘肃煤田地质局146队,甘肃平凉744000

出　　处：《矿物岩石地球化学通报》2024年第5期960-972,共13页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：山西工程职业学院2024年度院级项目(KY2024-34);国家重点研发计划项目(2016YFC0600502)。

摘　　要：为限定华北克拉通内的羊投崖岩体的岩石成因和构造背景,对羊投崖岩体中较新鲜的花岗斑岩开展地球化学、锆石年代学和Hf同位素研究。结果表明,羊投崖花岗斑岩形成于早白垩世(131.7±0.5Ma);花岗斑岩富硅,为高钾钙碱性系列弱过铝质花岗岩类;相对富集K、Pb、Rb等大离子亲石元素(LILEs)和轻稀土元素(LREE),相对亏损Nb、Ce、Zr、Ti等高场强元素(HFSEs)和重稀土元素(HREE);Eu呈负异常,ε_(Hf)(t)为–28.6~–19.7。研究表明,羊投崖花岗斑岩总体上为I型花岗岩,为古元古代–新太古代古老下地壳物质的部分熔融产物,但在成岩过程中有幔源物质参与,形成于早白垩世古太平洋板块向欧亚板块俯冲背景下的伸展构造环境,为中生代华北克拉通构造体制转折的产物。In order to constrain petrogenesis and tectonic setting of the Yangtouya intrusion in the North China Craton,we have carriedout geochronological,Hf isotopic and geochemical study of fresh granite porphyry samples from the Yangtouya intrusion in Shanxi Province.The results show that the granite porphyry of the Yangtouya intrusion was formed in Early Cretaceous(131.7±O.5Ma).The granite porphyry which is enriched in Si belongs to the high-K calc-alkaline weak peraluminous granite.It is relatively enriched in LILEs(such as K,Pb and Rb)and LREE,but relatively depleted in HFSEs(such as Nb,Ce,Zr and Ti)and HREE.Its samples have negative Eu anomalies.Their zircons have negative cHf(t)values ranging from-28.6 to-19.7.The granite porphyry of the Yangtouya intrusion is generally I-type granite.It was mainly formed by the magma derived from partial melting of the Neoarchean-Paleoproterozoic crustal materials with minor mantle-derived inputs.It was formed in extensional tectonic setting under the subduction of the Paleo-Pacific plate toward the Eurasian plate in the Early Cretaceous,and is the product of the transition of the North China Craton tectonic system in the Mesozoic era.

关 键 词：花岗斑岩 早白垩世 华北克拉通 构造背景 羊投崖岩体 

分 类 号：P597[天文地球—地球化学]