...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>International Journal of Earth Sciences >Downslope-shifting pockmarks: interplay between hydrocarbon leakage, sedimentations, currents and slope’s topography
【24h】

Downslope-shifting pockmarks: interplay between hydrocarbon leakage, sedimentations, currents and slope’s topography

机译：向下倾斜的麻点：油气泄漏，沉积，水流和斜坡地形之间的相互作用

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Pockmarks in Pliocene-Quaternary continental slope deposits offshore Angola show features related to: (1) fluid leakage craters that formed repeatedly, (2) authigenic methane-derived carbonates that indicate the (former) presence of hydrocarbons and (3) erosional–depositional structures that are clearly related to current activity. Depending on topography, the pockmarks show differing development: “Advancing Pockmarks” preferentially developed on regional slopes or inclined topography (> 2.5°–3°). They arranged in a chain-like pattern and mimic the outline of buried turbidite channels below. These pockmarks and their infill migrated downslope in response to shifting vents. “Nested Pockmarks” occur in gently sloping areas (< 2°). Their isolated conical infill records slope-parallel migration within a specific depth range pointing to the influence of contour currents. Both pockmark types are long-lived and they record preferential fluid migration along specific pathways, which developed at the downcurrent sidewalls of pockmarks due to flow separation initiating “cavity flow” within the pockmarks. The durable specific migration paths include pockmark sidewalls, vertically stacked erosional-interface of sediment waves, or entire pockmark bodies. The vertical extent of both pockmark types from End Miocene to the present-day seafloor documents various intensities of episodic fluid bursts followed by periods of quiescence and fill.
机译：安哥拉近岸上新世-第四纪大陆斜坡沉积物的麻点显示出以下特征：（1）反复形成的漏油坑；（2）自生甲烷的碳酸盐表明烃的存在（以前）；以及（3）侵蚀沉积结构显然与当前活动有关。视地形而定，麻点显示出不同的发展：“前进麻点”优先在区域斜坡或倾斜地形（> 2.5°–3°）上发展。它们以链状排列，并模仿了下面埋入的浊浊通道的轮廓。这些痘痕和它们的填充物响应于不断变化的通风孔而向下坡迁移。 “巢状麻点”出现在轻微倾斜的区域（<2°）。它们隔离的圆锥形填充物记录了在特定深度范围内的倾斜平行移动，表明轮廓电流的影响。两种痘痕类型都是长寿的，它们记录了沿特定路径的优先流体迁移，由于特定的流分离在痘痕内引发了“腔流”，因此沿斑点的下行流侧壁形成了特定的流体迁移。持久的特定迁移路径包括麻袋侧壁，沉积波垂直堆积的侵蚀界面或整个麻袋体。从中新世末期到今天的海底，这两种麻子类型的垂直范围都记录了各种强度的间歇性流体爆发，随后是静止期和填充期。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号