Submarine Mass Movements and Their Consequences - 6th International Symposium
Submarine Mass Movements and Their Consequences - 6th International Symposium
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潜艇群体运动及其后果 - 第六届国际研讨会
DOI：
10.1007/978-3-319-00972-8_41
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Krastel S
中科院分区：
文献类型：
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作者：
Krastel S
大西洋被动大陆边的特点是沉积层厚，可能变得不稳定，造成各种规模的山崩。不同的边缘部分之间的质量浪费类型不同，但这些差异的原因还不清楚。西北非洲大陆边的特点是有几个大规模但不经常发生的山崩，而德拉普拉塔河区域（阿根廷北方和乌拉圭）的大陆边则显示出广泛的小规模块状搬运沉积物。这些不同类型的质量浪费可以用不同的海洋学和沉积环境来解释。非洲西北部边缘的特点是海洋上涌造成的高初级生产力，以及局部集中的风成输入造成相对较高的沉积速率。这种情况导致沉积物不稳定，主要是由于沉积物的欠固结和广泛的软弱层。相比之下，乌拉圭和阿根廷北方外海的现代海洋边缘的特点是等深流强，河流沉积物量大，形成广泛的等深流沉积。这些等深岩可能不稳定，导致规模较小但更频繁的山体滑坡。
The passive continental margins of the Atlantic Ocean are characterized by thick sedimentary successions, which might become unstable resulting in landslides of various sizes. The type of mass-wasting differs between individual margin sections but the reasons for these differences are not well understood. The NW-African continental margin is characterized by several large-scale but infrequent landslides, while the continental margin in the de la Plata River region (northern Argentina and Uruguay) shows widespread small-scale mass transport deposits. These different styles of mass wasting can be explained by different oceanographic and sedimentary settings. The margin off Northwest Africa is characterized by high primary productivity caused by oceanic upwelling as well as locally focused aeolian input resulting in relatively high sedimentation rates. This setting leads to sediment instabilities arising primarily from underconsolidation of deposited sediments and widespread weak layers. In contrast, the modern ocean margin off Uruguay and northern Argentina is characterized by strong contour currents and a high amount of fluvial sediment resulting in widespread contouritic deposits. These contourites are potentially unstable leading to smaller but more frequent landslides.