在回滚潜伏过程中,地幔的热演变的实验室模型
1Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island 02882, USA. kincaid@gso.uri.edu
Nature
|September 5, 2003
概括
与2D模型相比,反向俯冲驱动更快的地幔流动和更均的板块加热. 实验室实验揭示了明显的3D地幔循环模式和温度结构,带有和没有板块回滚.
科学领域:
- 地质物理学 地质物理学
- 构造学 构造学 构造学 构造学
- 地力学是什么?地力学是什么?
背景情况:
- 海洋石化层的沉降对于板块构造学,地幔演化和材料回收至关重要.
- 之前的研究往往将降温简化为二维,忽视了诸如沟迁移和板块回滚等3D复杂性.
- 三维地幔流动,热条件和化学运输都是从地质化学,地震学和地力学模型推断出来的.
研究的目的:
- 为了研究和比较3D地幔循环和温度结构在反转和不反转的沉降过程中.
- 揭示由回滚元件的存在或不存在引起的地幔动态的根本差异.
主要方法:
- 实验室实验模拟潜水过程.
- 对3D地幔流动模式的分析.
- 测量地幔和海洋板内部的温度分布.
主要成果:
- 没有回滚的降温会导致地幔流缓慢,盘子周围没有质量流动,板边加热速度更快.
- 回转式俯冲驱动器在沉降板周围和下方流动,增加地幔形速度.
- 回转将焦点流向板的中心,并导致沿中心线更均的板表面加热.
结论:
- 与非回滚式俯冲相比,回滚显著改变了3D地幔循环和热结构.
- 实验室实验提供了对探区地力学复杂性的关键见解.
- 这些发现挑战了二维假设,并突出了潜水区3D过程的重要性.
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