南天山乔洛特达板花岗岩岩体成因——锆石U-Pb定年及地球化学证据  

Zircon U-Pb Dating and Its Geochemistry Evidence for the Formation of the Qiolotedaban Granite Body in the Southern Tianshan Mountains

作　　者：滕宇翔 郑飞 李咸阳 王哲 Teng Yuxiang;Zheng Fei;Li Xianyang;Wang Zhe(Xinjiang Geological Survey Institute,Urumqi,Xinjiang,830000,China)

机构地区：[1]新疆维吾尔自治区地质调查院,新疆乌鲁木齐830000

出　　处：《新疆地质》2024年第3期341-346,共6页Xinjiang Geology

基　　金：中央引导地方科技资金青藏高原北部西昆仑地区新生代火山活动与干热岩形成关系研究(ZYYD2023A12);新疆维吾尔自治区自然科学基金洋板块地层重建对卡拉麦里晚古生代洋盆俯冲削减的制约项目(2022D01A288)联合资助。

摘　　要：近年来,众多学者对吉尔吉斯洋、南天山洋盆演化取得了较多高精度测年证据,为探讨洋盆形成构造演化提供了基础资料。本文取得的锆石U-Pb同位素年龄位于天山中南段巴音布鲁克地区,该地区岩浆活动意味着天山中南段洋盆与板块活动记录。乔洛特达板岩体位于南天山北缘,由闪长岩、花岗闪长岩、二长花岗岩构成。以花岗闪长岩岩体作为研究对象,其微量元素显示富集Rb,K,Th,U,La,Ce,Nd,Hf,Sm;亏损Ba,Nb,P,Zr,Ti的地球化学特征。显示高硅、高铝特征,具轻稀土元素富集、重稀土元素亏损、弱负铕异常的稀土元素分布模式。测得花岗闪长岩锆石U-Pb年龄为(450.8±4.4)Ma(晚奥陶世),结合南天山北缘和中天山南缘同期花岗岩的出现,认为乔洛特达板花岗闪长岩体是破坏性活动板块边缘的产物。in recent years,many high-precision dating evidences have been obtained for the evolution of the Kyrgyz Ocean and the southern Ten-zan ocean basin,it provides helpful data for studying the formation and tectonic evolution of ocean basin.The zircon U-Pb isotopes obtained in this area are located in the Bayinbuluk area,south-central Ten-zan.The magmatic activity in this area means that the central-south Tianshan Mountains record the ocean basin and plate activity in south-central Ten-zan.The cholotada slate,a granitic body composed of diorite,Granodiorite and monzonite,is located in the northern margin of south Ten-zan.The granodiorite body is the object of study in this paper,the micronutrient show the characteristics of granite geochemistry enriched in Rb,k,Th,U,La,Ce,ND,Hf,Sm and deficient in BA,NB,p,Zr and Ti.The granodiorite show the characteristics of high silicon and high aluminum,with the distribution pattern of light rare earth element enrichment and heavy rare earth element deficiency,and weak negative europium anomaly.The granodiorite age was(450.8±4.4)Ma(Late Ordovician)by Zircon U-Pb method,combined with the occurrence of similar synchronic granites in the northern margin of south Ten-zan and the southern margin of central Ten-zan,it is suggested that the granodiorite of the cholo TEDA slate is a product of the edge of a destructive active plate.

关 键 词：锆石U-Pb年龄 花岗闪长岩 乔洛特达板岩体 巴音布鲁克北缘 

分 类 号：P597.3[天文地球—地球化学] P588.121[天文地球—地质学]