赣东北贵溪地区片岩中碎屑锆石的U-Pb年龄、Hf同位素及其地质意义
DOI:
作者:
作者单位:

作者简介:

通讯作者:

中图分类号:

基金项目:

国家重点基金项目(40930419)和国土资源部公益性行业科研专项经费项目(200911007)资助。


U-Pb ages and Hf isotopes of detrital zircons from mica quartz schist in Guixi area of northeastern Jiangxi Province and their geological significance
Author:
Affiliation:

Fund Project:

  • 摘要
  • |
  • 图/表
  • |
  • 访问统计
  • |
  • 参考文献
  • |
  • 相似文献
  • |
  • 引证文献
  • |
  • 资源附件
  • |
  • 文章评论
    摘要:

    提要:应用LA-ICP-MS U-Pb同位素原位微区定年方法及Hf同位素和微量元素分析方法,对华夏地块北部赣东北地区1个云母石英片岩中48个碎屑锆石进行了系统研究。这些锆石大部分具特征的振荡环带,Th/U比值较高(>0.4),稀土元素配分型式左倾(富集 HREE),具明显正Ce和负Eu 异常, 属于特征的岩浆锆石。年代学研究显示,华夏北部新元古代变沉积岩主要在~775 Ma出现峰值并在~840 Ma出现次高峰,说明在此时期有两期大规模的岩浆活动。~840 Ma的峰值锆石对应的εHf(t)值明显分为两个区间,既有正值,也有负值,而在~775 Ma的峰值锆石对应测定的εHf(t)值均为负值。结合前人的Hf同位素测试结果,说明华夏地块新元古代中期岩浆活动主要表现为古老陆壳物质的再循环。形成于古元古代~1770 Ma的一个次高峰的年龄数据非常一致,单一的Hf同位素成分和较好的锆石晶形表明它们最可能捕获于深部的一个古元古代基底岩石。

    Abstract:

    Abstract:Detailed LA-ICP-MS U-Pb dating and LAM-MC-ICPMS Lu-Hf isotope analysis were carried out for zircons in a mica quartz schist sample from Guixi area of northern Cathaysia Block, South China. These zircons are characterized by zoning, higher Th/U ratios (>0.4), HREE enrichment and positive Ce and negative Eu anomalies, and are similar to magmatic zircons in some aspects. Zircon U-Pb geochronological results of the mica quartz schist show a peak at ~775 Ma and a secondary peak at ~840 Ma, probably corresponding to two large-scale magmatic events. εHf(t) values for the ~840 Ma zircons could be divided into two intervals with both negative or positive values, whereas εHf(t) values for the ~775 Ma zircons are all negative values. Combined with previous zricon U-Pb dating and Hf isotopic results, the authors conclude that the Neoproterozoic magmatism in the Cathyasia Block mainly found expression in recycling of ancient crustal components. Nine zircon grains from the mica quartz schist with the other secondary peak at around 1770 Ma have very constant U-Pb ages and Hf isotopic composition, implying that they were most probably captured from the Paleoproterozoic basement rock.

    参考文献
    相似文献
    引证文献
引用本文

苏慧敏 张承帅. 赣东北贵溪地区片岩中碎屑锆石的U-Pb年龄、Hf同位素及其地质意义[J]. 中国地质, 2012, 39(6): 1577-1592.
SU Hui-min, ZHANG Cheng-shuai. U-Pb ages and Hf isotopes of detrital zircons from mica quartz schist in Guixi area of northeastern Jiangxi Province and their geological significance[J]. Geology in China, 2012, 39(6): 1577-1592(in Chinese with English abstract).

复制
分享
文章指标
  • 点击次数:
  • 下载次数:
  • HTML阅读次数:
  • 引用次数:
历史
  • 收稿日期:
  • 最后修改日期:
  • 录用日期:
  • 在线发布日期: 2013-02-20
  • 出版日期:
亮点文章推荐
古人云:工欲善其事,必先利其器。我国新一轮战略找矿行动已全面启动。用什么方法、什么手段实现增储上产是面临的突出问题。本刊登载了几篇基于新技术、新方法实现找矿突破的实例,供大家参阅,助力新一轮战略找矿目标的实现。
基于随机森林算法的找矿预测——以冈底斯成矿带西段斑岩—浅成低温热液型铜多金属矿为例. 欧阳渊等,2023, 50(2):303-330.
基于重磁资料在山东齐河—禹城探获矽卡岩型富铁矿:对超深覆盖区找矿的启示. 王润生等,2023, 50(2):331-346.
自然伽马曲线重构波阻抗反演在勘探含铀有利成矿砂体中的尝试. 梁建刚等,2023, 50(2):347-358.
宽频大地电磁法寻找“界面型”隐伏金矿床:以黔西南戈塘地区深部找矿为例. 张伟等,2023, 50(2):359-375.
页岩气基础地质调查钻井技术研究进展及展望. 赵洪波等,2023, 50(2):376-394.
关闭