低电阻与纳斯卡平板板在阿根廷下方的入有关
John R Booker1, Alicia Favetto, M Cristina Pomposiello
1Department of Earth and Space Sciences, Box 351310, University of Washington, Seattle, Washington 98195, USA. booker@ess.washington.edu
Nature
|May 28, 2004
概括
这项研究揭示了安第斯山脉下部部分融化,这可能解释了纳斯卡板块的平面降温.
科学领域:
- 地质学和构造学地质学和构造学
- 地幔动力学和融化过程
背景情况:
- 海洋石化层在安第斯山脉下面向东下,通常在地幔中形成岩源.
- 纳斯卡板块 (28-33°S) 的一块平板段通过破坏地幔子,阻止了安第斯山脉的火山活动.
- 波动性资产的命运和平板板回滚的机制仍然不太清楚.
研究的目的:
- 为了研究阿根廷中部平板板段下方的导电结构.
- 为了推断与纳斯卡板块沉降相关的部分融化的存在和深度.
- 探索对地幔挥发性传输和平板板动态的影响.
主要方法:
- 在阿根廷中部沿着一个档案获取和分析磁铁电流数据.
- 对增强电导异常的解释.
- 模拟部分融化分布和潜在的挥发性来源.
主要成果:
- 在纳斯卡板块的东侧沿线推断出增强的导电能力.
- 证据表明,部分融化的存在延伸到至少250公里的深度,可能超过400公里.
- 导电异常可能表明410公里不连续性供应了融.
结论:
- 这些发现支持平板板区域下部部分融的存在,可能与潜水板有关.
- 这种部分融化可能持续到相当深处,或从地幔过渡区供应.
- 结果与"水过器"模型一致,解释了挥发性运输和平板行为.
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