新泽西大陆斜坡的过压和流体流动:影响斜坡失效和冷透
1503 Deike Building, Department of Geosciences, Penn State University, University Park, PA 16802, USA.
概括
新泽西大陆坡上的压缩不足的沉积物显示出由于快速沉积而引起的高流体压力. 这一由侧面压力平衡驱动的过程,可能会在全球范围内引发斜坡故障和冷透.
科学领域:
- 地质地质地质地质地质地
- 地质物理学 地质物理学
- 海洋学 海洋学 海洋学
背景情况:
- 新泽西大陆坡上的沉积物表现出低压缩.
- 高流体压力,达到石静压力的95%,在海洋钻探计划站点1073海底下640米观察到.
研究的目的:
- 调查米奥森到普莱斯托纪沉积物中低压缩和高流体压力背后的机制.
- 为了建模快速沉积,沉积物质和流体压力积累之间的关系.
主要方法:
- 来自海洋钻井计划站点1073.3的沉积芯的分析.
- 开发和应用一个模拟沉积和流体流动的二维数值模型.
- 模型预测与观察到的沉积物多孔性和流体压力数据的比较.
主要成果:
- 二维模型成功预测了观察到的高流体压力.
- 快速普莱斯托时代沉积加载透的米奥时代沙泥被确定为主要驱动因素.
- 在透床的侧向压力平衡被证明可以将液体压力集中到超负荷较小的地方.
结论:
- 新泽西大陆斜坡的低压缩和高流体压力是快速沉积和横向流体压力转移的结果.
- 这种现象对斜坡的稳定性和海底滑坡的发生有重大影响.
- 这些发现表明,在被动大陆边缘驱动冷透的潜在全球机制.
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