• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Chinese science bulletin >An in situ zircon Hf isotopic, U-Pb age and trace element study of banded granulite xenolith from Hannuoba basalt: Tracking the early evolution of the lower crust in the North China craton
【24h】

An in situ zircon Hf isotopic, U-Pb age and trace element study of banded granulite xenolith from Hannuoba basalt: Tracking the early evolution of the lower crust in the North China craton

机译：汉诺巴玄武岩带状粒状异种岩的原位锆石Hf同位素，U-Pb年龄和微量元素研究：追踪华北克拉通下地壳的早期演化

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Backscattcred electron images, in situ Hf isotopes, U-Pb ages and trace elements of zircons in a banded granulite xenolith from Hannuoba basalt have been studied. The results show that the banded granulite is a sample derived from the early lower crust of the North China craton. It is difficult to explain the petrogencsis of the xenolith with a single process. Abundant information on several processes, however, is contained in the granulite. These processes include the addition of mantle material, crustal remelting, metamorphic differentiation and the delamination of early lower crust. About 80% of zircons studied yield ages of 1842 ±40 Ma, except few ages of 3097--2824 Ma and 2489-2447 Ma. The zircons with ages older than 2447 Ma have high epsilon_(Hf) (up to +18.3) and high Hf model age (2.5--2.6 Ga), indicating that the primitive materials of the granulite were derived mainly from a depleted mantle source in late Archean. Most epsilon_(Hf) of the zircons with early Proterozoic U-Pb age vary around zero, but two have high epsilon_(Hf) up to +9.2--+10.2, indicating mantle contribution during the collision and assembly between the Eastern and Western blocks in the early Proterozoic that resulted in the amalgamation of the North China craton.
机译：研究了汉诺巴玄武岩带状粒状异岩体中的后向电子图像，原位Hf同位素，U-Pb年龄和锆石的微量元素。结果表明，带状花岗石是华北克拉通早期下地壳的样品。很难用一个过程来解释异种岩的成岩作用。然而，花岗石中包含有关多个过程的大量信息。这些过程包括添加地幔物质，地壳重熔，变质作用分化和早期下地壳分层。大约80％的锆石研究的屈服年龄为1842±40 Ma，少数年龄为3097--2824 Ma和2489-2447 Ma。年龄大于2447 Ma的锆石具有较高的epsilon_（Hf）（高达+18.3）和较高的Hf模型年龄（2.5--2.6 Ga），表明该花岗石的原始材料主要来自于贫化的地幔源。晚太古代。早期元古代U-Pb年龄的锆石中的大多数epsilon_（Hf）均在零附近变化，但是两个锆石的epsilon_（Hf）高达+9.2-+ 10.2，表明东西方块体在碰撞和组装过程中的地幔贡献在元古代早期导致了华北克拉通的合并。

著录项

相似文献

  • 外文文献
  • 中文文献
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号