赣南东源里岩体锆石U-Pb年代学和Hf同位素特征

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• 英文论文题名：Zircon U-Pb geochronology and Hf isotopes of the Dongyuanli granite body in southern Jiangxi province
• 论文作者：章发明 ; 党飞鹏 ; 张鸿
• 英文论文作者：ZHANG Fa-ming ; DANG Fei-peng ; ZHANG Hong ; Research Institute No.270 ; CNNC
• 年：2015
• 作者机构：核工业二七〇研究所;
• 论文关键词：S型花岗岩 ; 锆石U-Pb年代学 ; 东源里岩体 ; 赣南
• 英文论文关键词：S-type granite ; zircon U-Pb geochronology ; dongyuanli granite body ; southern Jiangxi province
• 会议召开时间：2015-09-21
• 会议录名称：中国核科学技术进展报告（第四卷）——中国核学会2015年学术年会论文集第1册（铀矿地质分卷、铀矿冶分卷）
• 语种：中文
• 分类号：P597;P619.14
• 学会代码：EGVD
• 会议名称：中国核学会2015年学术年会
• 会议地点：中国四川绵阳
• 主办单位：中国核学会
• 学会名称：中国核学会
• 页数：8
• 文件大小：675k
• 原文格式：O
• 会议级别：全国

摘要

赣南东源里岩体位于南岭东段北部桃山复式花岗岩体的北东部,紧邻产铀的打鼓寨岩体。本文利用高精度激光剥蚀-多接收器电感耦合等离子体质谱法获得东源里中粒斑状二云二长花岗岩的LA-ICPMS锆石U-Pb年龄为(163.4±3.1)Ma(MSWD=2.4),属中侏罗世,说明东源里岩体是燕山早期岩浆活动的产物。锆石原位Hf同位素特征:~(176)Hf/~(177)Hf=0.282 319~0.282 422、ε_(Hf)(t)=-12.5~-8.8和T_(DM2)=1 774~1 569 Ma。结合岩相学、同位素地球化学特征综合分析认为,东源里岩体形成于燕山早期主造山的晚阶段,是脉动式伸展作用下古老(中元古代早长城世Ch_1)的下地壳玄武质岩石减压重熔的产物。
The Taoshan granite complex located at the north-east part of Nanling region.The Dongyuanli granite body is lying in the north eastern of Taoshan zone,which adjoins to the Daguzhai body with uranium.High precision techniques of Laser Ablation-Multicollector Inductively Coupled Plasma-Mass Spectrometry(LA-MC-ICPMS) have been used to redetermine the emplacement age of the body and the method is reported in this paper.The results indicate that Dongyuanli granite body was formed in the Middle Jurassic[(163.4 ± 3.1) Ma].Its Zircon Hf isotopic compositions are~(176) Hf/~(177) Hf=0.282 319 ~ 0.282 422,ε_(Hf)(t) =-12.5~-8.8 and T_(DM2) =1774~ 1 569 Ma,show its crust origin.Comprehensive analysis reveals that the body is formed under the control of continental late-orogenic tectonic setting of the impulse extension on Early Yanshanian periods,with the source as the result of the lower(basaltic) crust partial remelting.

引文

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