脊柱在平面板块的形成和寿命中的作用
Sanja Knezevic Antonijevic1, Lara S Wagner2, Abhash Kumar1
1Department of Geological Sciences, University of North Carolina at Chapel Hill, CB 3315, Chapel Hill, North Carolina 27599, USA.
Nature
|August 14, 2015
概括
纳斯卡山脉对于秘鲁的平板岩起伏至关重要, 它的移除将导致平板崩, 提供洞察过去的地质事件,
科学领域:
- 地质学
- 构造学
- 地质学
背景情况:
- 平板岩层的沉降,即下降的板块变为水平,与地升起和远离板块边界的不同寻常的火山活动有关.
- 过去的事件,如美国西部的拉拉米德土壤形成,都归因于古代的平板浮沉.
研究的目的:
- 调查秘鲁最大的现代平板岩石,了解平板岩石的形成和程度.
- 确定纳斯卡山脉在维护秘鲁平面板块中的作用.
主要方法:
- 雷利波相速的分析.
- 改进了地震转移功能.
- 地理数据的解释.
主要成果:
- 纳斯卡山脉对于90公里深处的水平板块的发展和支至关重要.
- 平板在山脊上方是最浅的,开始向西北倾斜和撕裂,重新开始正常的沉降.
- 脊柱的存在是必要的,但不足以形成平板岩石;其去除就足以导致其失效.
结论:
- 提出了秘鲁平面板块演变的概念模型,涉及沟退缩,吸收和山脊沉降.
- 这些发现为拉拉米德和其它平板石事件的启动和停止提供了新的约束.
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