来自MELT区域的地球物理证据用于对海洋板块的组成控制
Rob L Evans1, Greg Hirth, Kiyoshi Baba
1Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA. revans@whoi.edu
Nature
|September 9, 2005
概括
MELT实验揭示了东太平洋上升下面的融化分布受到水含量下降的影响,而不仅仅是冷却. 这影响了海洋石化层的早期演变.
科学领域:
- 地质物理学 地质物理学
- 海洋学 海洋学 海洋学
- 固体地球科学 固体地球科学
背景情况:
- 东太平洋起是研究中洋脊流程的关键地点.
- 了解海洋石化层演变需要了解融化分布和物理性质.
研究的目的:
- 为了限制南部东太平洋上升下面的融化分布.
- 研究海洋石化层的早期冷却历史和演变.
主要方法:
- 利用了来自MELT实验的磁和地震数据.
- 分析的结构大约在山脊顶的东部100至350公里处 (1.34.5 Myr海底年龄).
主要成果:
- 观察到电导率在60公里深度以下显著增加.
- 检测到一个从等离子向横向异离子电结构的过渡.
- 发现该结构在研究区域中在很大程度上独立于年龄.
结论:
- 推断,由于融化,60公里以上的水含量下降控制了年轻的海洋板块结构.
- 这与导电冷却模型的预测形成鲜明对比.
- 这些发现为中洋山脊的岩和热水过程提供了洞察力.
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