陕西汉南毕机沟钒-钛磁铁矿锆石U-Pb年代学及其意义
投稿时间:2016-11-04  修订日期:2017-02-09  点此下载全文
引用本文:
DOI:
摘要点击次数: 42
全文下载次数: 
作者单位E-mail
陈龙耀 中国地质科学院地质力学研究所 18810405249@163.com 
刘晓春 中国地质科学院地质力学研究所  
中文摘要:毕机沟钒钛磁铁矿位于扬子板块北缘汉南杂岩的西北部,是基性-超基性杂岩体分异演化的产物。矿区范围出露的岩石主要包括橄长岩、辉长岩、辉长闪长岩和闪长岩,具有明显岩相分带和韵律旋回特征。目前,已发现的多个钒钛磁铁矿体均位于基性岩-超基性杂岩体的辉长岩相带内。本次研究对毕机沟矿区的含矿辉长岩和穿切含矿辉长岩的花岗岩脉进行了原位微区LA-MC-ICPMS锆石U-Pb定年,获得两者的侵位时间分别为783±4 Ma(MSWD=0.09)和759±4 Ma(MSWD=1.50),结果表明毕机沟钒钛磁铁矿的成矿时代大约为783 Ma,但不晚于759 Ma。结合前人区域成果资料,毕机沟含钒钛磁铁矿的基性-超基性杂岩体与该区新元古代大规模具岛弧性质的基性-超基性杂岩体的形成时代相近,我们认为毕机沟钒-钛磁铁矿可能形成于活动型大陆边缘环境。
中文关键词:毕机沟  汉南基性-超基性杂岩体  钒-钛磁铁矿  锆石U-Pb年龄
 
Zircon U-Pb geochronology of the Bijigou V-Ti magnetite deposit and its significance, Hannan, Shanxi
Abstract:The Bijigou V-Ti magnetite deposit is situated in the northwest of the Hannan Complex, the northern margin of the Yangtze Plate, and is the product of the mafic-ultramafic magma differentiation. It consists mainly of olivine gabbro, gabbro, gabbro diorite and diorite, and exhibits clear lithofacies belts and rhythmicity. Several V-Ti magnetite bodies have been found in the gabbro lithofacies belt of mafic-ultramafic complex. In order to find out the metallogenic epoch of the Bijigou V-Ti magnetite deposit, we present new laser ablation–multicollector–inductively coupled plasma–mass spectrometry (LA-MC-ICP-MS) U-Pb data for zircons from mineralized gabbro and granite dike in the Bijigou V-Ti magnetite deposit, yielding the emplacement ages are 783±4 Ma (MSWD=0.09) and 759±4 Ma (MSWD=1.50), respectively. These new ages suggest that the mineralization age of the Bijigou V-Ti magnetite deposit was 783 Ma and no later than 759 Ma. Coupled with previous regional data, the age of the mafic-ultramafic rock containing V-Ti magnetite deposit in Bijigou is similar to the age of Neoproterozoic large scale mafic-ultramafic complex with arc properties. Therefore, we think that the Bijigou V-Ti magnetite deposit might be formed along the active continental margin.
keywords:Bijigou  Hannan mafic-ultramafic complex  V-Ti magnetite deposit  zircon U-Pb ages
  查看/发表评论  下载PDF阅读器
版权所有 《地球学报》编辑部 Copyright©2008 All Rights Reserved
主管单位:国土资源部 主办单位:中国地质科学院
地址: 北京市西城区百万庄大街26号,中国地质科学院东楼317室 邮编:100037 电话:010-68327396 E-mail: diqiuxb@126.com
技术支持:东方网景