沿着海洋转变断层的重力异常的传播速度依赖性
Patricia M Gregg1, Jian Lin, Mark D Behn
1Department of Geology and Geophysics, Massachusetts Institute of Technology/Woods Hole Oceanographic Institution Joint Program, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA.
Nature
|July 13, 2007
概括
中洋山脊转换断层显示了与传播速度相关的重力异常. 更快的扩散速度与负重力异常相关,表明这些断层附近的地厚度增加和3D岩积累.
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
- 海洋学 海洋学 海洋学
背景情况:
- 中洋山脊形态和地积受传播速度的影响.
- 缓慢扩散的山脊显示地在偏移处变薄,这是由于地幔聚焦的上升.
- 快速扩散的山脊具有均的地幔上升和较小的地厚度变化.
研究的目的:
- 研究海洋转变断层的传播速度和重力异常之间的关系.
- 了解地下质量分布和变形断层的地质过程.
主要方法:
- 对残余地幔布格尔重力异常的系统研究.
- 对19个海洋转变断层的分析.
- 重力特征与扩散率的相关性.
主要成果:
- 缓慢滑动的转变断层具有正重力异常.
- 中间和快滑转型断层表现出负重力异常.
- 负异常与地形高度相关,表明地的加厚.
结论:
- 在中间和快速滑动的转换断层存在质量赤字.
- 地的加厚是导致负重力异常的重要因素.
- 三维的岩积累可能发生在快速扩散的转变断层附近.
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