在410公里和660公里不连续性处,地震证据显示了橄酸相变化
Sergei Lebedev1, Sébastien Chevrot, Rob D van der Hilst
1Department of Earth, Atmospheric, and Planetary Sciences, Room 54-512, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. sergei@quake.mit.edu
概括
地震数据支持地幔过渡区的理论.
科学领域:
- 地质物理学 地质物理学
- 矿物物理 矿物物理
背景情况:
- 地幔过渡区 (MTZ) 的特点是410公里和660公里深处的地震断裂.
- 这些不连续性的原因,特别是它们是否由于橄素的同化学相变化,是有争议的.
研究的目的:
- 调查橄类相变的作用在定义地幔过渡区的地震不连续性.
- 为了使地震观测与矿物物理数据相协调.
主要方法:
- 来自东亚和澳大利亚的转换波测量的综合分析.
- 与区域断层扫描研究的地震速度数据的整合.
主要成果:
- 观察到MTZ厚度和波速变化之间的相关性,与olivine结构转换一致.
- 在地震学上推断的克拉佩隆斜坡与矿物学上的克拉佩隆斜坡对齐,用于 (Mg,Fe) 2SiO4旋转和后旋转转变.
结论:
- 这项研究提供了强有力的证据,支持橄酸相变化是MTZ地震不连续性的原因.
- 这些发现使地质物理观测与矿物物理原理相协调,增强了我们对地球深层过程的理解.
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