Triggers of sand remobilization in deep marine deposits
Triggers of sand remobilization in deep marine deposits
复制标题
深海沉积物沙子再活化的触发因素
DOI：
10.1144/sp493-2018-35
复制
发表时间：
2019
期刊：
影响因子：
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通讯作者：
L. Watsend
中科院分区：
文献类型：
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作者：
C. Hermanrud;E. Christensen;M. Haugvaldstad;L. M. Røynestad;I. T. Tjensvold;L. Watsend
注砂在深海沉积物和其他边坡不稳定的环境中被过度使用。我们研究了北海的地震数据，以揭示它们的主要触发机制。这是通过对乌茨拉高地渐新世至中新世沉积物的局部地震观测和北海北部霍达兰群顶部表面土丘的区域分布分析来完成的。我们观察到：(1)自升式褶皱的隆升在大多数情况下大于土丘内的砂厚；(2)在有砂沉积的时期存在对土丘的上覆，但在砂输入很少或没有砂输入的时期沉积的泥岩中没有这种上覆；(3)在乌特西拉高地以上，可以看到对几个渐新世表面的上覆。(4)渐新世和中新世土丘附近不存在边缘向斜；(5)影响霍达兰群顶部表面的土丘只存在于盆地侧翼和盆地-侧翼过渡处，而不存在于盆地中心。我们认为早期板块滑动的触发可以解释这些观察结果。
Abstract Sand injections are overrepresented in deep marine deposits and other settings with slope instabilities. We have examined seismic data from the North Sea to reveal their main trigger mechanisms. This was performed by inspection of local seismic observations in the Oligocene to Miocene sediments above the Utsira High and analyses of regional distribution of mounds at the top Hordaland Group surface in the northern North Sea. We make the observations that (1) the uplift of jack-up folds is in most cases larger than the sand thickness within the mounds, (2) onlap to mounds is present in periods with sand deposition, but no such onlap is seen in mudstones that were deposited in periods with little or no sand input, (3) onlapping to several Oligocene surfaces is seen above the Utsira High, (4) rim synclines are not present adjacent to Oligocene and Miocene mounds and (5) mounds that affect the top Hordaland Group surface are present in basin flanks and at basin-flank transitions but not in basin centres. We suggest that triggering by incipient slab sliding can explain these observations.