岩贫的大陆边缘的演变,从裂变到海底扩散
R B Whitmarsh1, G Manatschal, T A Minshull
1Southampton Oceanography Centre, European Way, Southampton, SO14 3ZH, UK. rbw@soc.soton.ac.uk
Nature
|September 15, 2001
概括
大陆裂涉及到构造学和岩石学的单独模型. 新的研究揭示了一个挖掘出大陆地幔的区域,在破裂过程中桥接大陆和海洋地.
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
- 地质地质地质地质地质地
背景情况:
- 大陆裂纹模型通常会把构造学和岩石学分开来.
- 很少有模型模拟大陆的分裂,融化,以及海底扩散的演变.
- 传统模型将大陆和海洋地相对应.
研究的目的:
- 提出支持在岩贫困裂边缘挖掘出大陆地幔的区域的观测结果.
- 为大陆扩张和分裂的最后阶段提出一个概念模型.
- 描述大陆裂变演变为海底扩散的过程.
主要方法:
- 来自西伊比利亚边缘的地质物理和地质观测.
- 在阿尔卑斯山的前Tethys海洋边缘的地质绘制.
- 基于现场观测的概念模型的开发.
主要成果:
- 证据表明,在大陆和海洋地之间,有几十公里宽的挖掘的大陆地幔区域.
- 来自西伊比利亚和阿尔卑斯山的观测证实了这一模型.
- 一个概念模型说明了大陆分裂的最后阶段.
结论:
- 大陆的分裂涉及到一个被挖掘的大陆地幔的区域,演变为海底的扩散.
- 压力和热场受到上升的天气层地幔的约束.
- 岩石和延伸速度在向海洋的方向上系统地增加.
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