石化层-石化层系统的电动异性质的实验约束
Anne Pommier1, Kurt Leinenweber2, David L Kohlstedt3
11] University of California San Diego, Scripps Institution of Oceanography, Institute of Geophysics and Planetary Physics, La Jolla, California 92093, USA [2] School of Earth and Space Exploration, Arizona State University, Tempe, Arizona 85287, USA.
Nature
|June 12, 2015
概括
变形的地幔岩石表现出与变形一致的电导率,解释了地震和电异常. 这表明融化对齐的橄岩层控制了地幔导电性.
科学领域:
- 地质物理学 地质物理学
- 矿物物理 矿物物理
- 构造学 构造学 构造学 构造学
背景情况:
- 石质层板的运动会导致石质层-石质层边界附近的变形.
- 天气层粘度降低,可能是由于融化或水,解释了地震和电气异常.
- 融化对变形地幔物质特性的影响还不太清楚.
研究的目的:
- 研究融化对变形地幔岩石电特性的影响.
- 限制融化在产生观察到的地幔导电异常中的作用.
- 在部分化的上层地幔中开发电异构的模型.
主要方法:
- 在高温 (<900°C) 和高压 (~3 GPa) 下,对变形的橄石和部分化岩石进行电异性测量.
- 橄石聚合物和部分化的岩石的实验变形.
- 在分层,变形的地幔中开发一种基于实验的电导率模型.
主要成果:
- 在所有样本中,电导率与变形方向平行最高.
- 与未变形样本相比,高度剪切的橄石的导电性增加了十倍.
- 一个具有切割橄和融化的交替层的模型最能解释高电异性 (高达100倍) 和现场数据.
结论:
- 变形和融化对齐是天气层中高电导率的关键.
- 拟议的模型解释了地带导电性深度在化带有区域的概况.
- 覆盖着同otropic,导电的下层岩层的电气异型的天气层与现场数据一致.
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