地球上层地幔流场的同位素描绘
Christine M Meyzen1, Janne Blichert-Toft, John N Ludden
1Laboratoire des Sciences de la Terre, CNRS UMR 5570, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, 46 Allée d'Italie, 69364 Lyon cedex 07, France. christine.meyzen@ens-lyon.fr
Nature
|June 29, 2007
概括
地球 地球 地球 地球 地球 地球
科学领域:
- 地质科学 地质科学
- 地球科学 地球科学 地球科学
背景情况:
- 地球的地幔在板块构造学中起着至关重要的作用.
- 了解地幔对流和物质循环的过程对于理解地质现象至关重要.
- 控制海底板块回流到上层地幔的机制尚未完全理解.
研究的目的:
- 通过分析地化学特征来研究上层地幔的补充模式.
- 绘制地化学领域的地图,以及它们与地幔对流的关系.
- 了解大陆基尔对上层地幔再填充过程的影响.
主要方法:
- 对长寿命放射性同位素,特别是哈同位素,沿西南印度山脊进行分析.
- 使用同位素数据来划分地质化学领域.
- 将地球化学领域与地震数据和羽毛活动相关联.
主要成果:
- 在不同的海洋省份确定了上层地幔的对比的补充模式.
- 沿西南印度山脊观察到海同位素组成的急剧转变,表明了不同的地幔领域.
- 在印度省发现了低地幔同位素影响的证据,在南大西洋省发现了高地幔物质污染的证据.
- 连接的上层地幔重新填充到南非和阿法尔羽毛下的异常.
- 证明大陆基尔的粘性拖延减缓并局部化了大西洋和印度领域的上游.
- 在未受阻碍的太平洋领域观察到更广泛,更快速的上升.
结论:
- 使用放射性同位素绘制的地球化学领域,揭示了对比的上层地幔补充机制.
- 大陆基尔显著影响地幔流动,导致局部上升.
- 太平洋区域由于缺乏大陆影响而表现出更高效和更广泛的地幔再填充.
- 这项研究提供了对支配地幔对流和板块构造的动态过程的见解.
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