太行山南段安林地区侵入岩LA-ICP-MS锆石U-Pb年龄、地球化学特征及其构造意义  

LA-ICP-MS zircon U-Pb age,geochemical characteristics and tectonic significance of intrusive rocks in Anlin area,southern Taihang Mountains

作　　者：余智慧 吴园园 王巧玲 王剑锋 陈昊龙 王明明 祝少辉 陈春景 王昊 袁要伟 李玉芹 YU Zhihui;WU Yuanyuan;WANG Qiaoling;WANG Jianfeng;CHEN Haolong;WANG Mingming;ZHU Shaohui;CHEN Chunjing;WANG Hao;YUAN Yaowei;LI Yuqin(The Seventh Geological Brigade of Henan Nonferrous Metal Geology and Mineral Resources Bureau,Zhengzhou,450016;Henan Nonferrous Metal Mineral Exploration Engineering Technology Research Center,Zhengzhou,450016)

机构地区：[1]河南省有色金属地质矿产局第七地质大队,郑州450016 [2]河南省有色金属矿产探测工程技术研究中心,郑州450016

出　　处：《地质论评》2022年第3期877-890,共14页Geological Review

基　　金：河南省财政地质勘查项目“任村幅、岳城幅1∶5万区域地质、战略性矿产远景调查”项目(编号:豫国土资发﹝2013﹞7号)的成果。

摘　　要：太行山南段安林地区中生代侵入岩LA-ICP-MS锆石U-Pb测年表明侵入岩形成于129.1±1.0~129.7±1.1 Ma,属于早白垩世,与太行山其他地区乃至整个华北地区侵入杂岩体具有相近的形成年代,表明在晚中生代太行山地区与华北地区经历了相同的地球动力学背景和构造环境,即南太行山地区处于华北克拉通岩石圈减薄范围之内。安林地区中生代侵入岩轻稀土总量(LREE平均为113.71×10^(-6))明显高于重稀土总量(HREE平均为11.97×10^(-6)),具有相对明显的富集轻稀土元素的右倾型配分形式、Eu的弱正异常及大离子亲石元素相对富集的特征,且具有Sr、Ba含量高、Sr/Y、(La/Yb)_(N)比值高的特征,表明壳幔岩浆混合是太行山南段安林地区中生代岩浆作用的主要成因机制。Objectives:The Early Cretaceous intrusive rocks with large exposed area in Anlin area in the south of Taihang Mountain are studied.Through the study of the genetic types,material sources and formation age of the intrusive rocks in this area,the regional tectonic evolution process of Anlin area and the lithospheric thinning mechanism in Taihang Mountains area are further discussed.Methods:Detailed geological survey,rock geochemistry and LA-ICP-MS zircon U-Pb chronology of Mesozoic intrusive rocks in Anlin area,southern Taihang Mountains.Results:The study shows that the intrusive rocks in Anlin area were formed in 129.1±1.0~129.7±1.1 Ma,belonging to the Early Cretaceous,which is similar to the intrusive complexes in other areas of Taihang Mountains and even the whole North China;The total amount of light rare earths(LREE is 113.71×10^(-6) on average)in Mesozoic intrusive rocks in Anlin area is significantly higher than that of heavy rare earths(HREE is 11.97×10^(-6) on average),which has the characteristics of relatively obvious right inclined distribution form of enriching light rare earth elements,weak positive anomaly of Eu and relative enrichment of large ion lithophile elements,and has the characteristics of high Sr and Ba content and high Sr/Y,(LA/Yb)_(N) ratio.Conclusions:The late Mesozoic Taihang Mountains Area and North China experienced the same geodynamic background and tectonic environment,indicating that the South Taihang Mountains area is within the lithospheric thinning range of the North China Craton;combined with the characteristics of regional tectonic evolution,the main genetic mechanism of Mesozoic magmatism in Anlin area in the southern part of Taihang Mountains is crust mantle magmatic mixing.

关 键 词：太行山南段 安林地区 中生代侵入岩 壳幔岩浆混合 

分 类 号：P588.12[天文地球—岩石学] P597.3[天文地球—地质学]