Identification, Correlation and Origin of Multistage Landslide Events in Volcaniclastic Turbidites in the Moroccan Turbidite System
Identification, Correlation and Origin of Multistage Landslide Events in Volcaniclastic Turbidites in the Moroccan Turbidite System
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摩洛哥浊积岩系统火山碎屑浊积岩多期滑坡事件的识别、关联和成因
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
I. Croudace
中科院分区：
文献类型：
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作者：
J. Hunt;R. Wynn;I. Croudace
海底滑坡引发海啸对滑坡体的体积、破坏机制和相对于海平面的破坏位置等参数很敏感。这些情况往往很难解决过去的事件。然而，以往的研究浊积岩产生的滑坡提供洞察的时间，总事件量和故障机制。这项研究证实了~ 165 ka Icod滑坡起源于特内里费岛的北方侧翼作为一个倒退的多级滑坡。它还表明，最近的火山侧翼崩溃从加那利群岛，~ 15 ka埃尔戈尔福滑坡，是一个倒退的多级故障。这些推论是使用高分辨率Itrax μXRF体相地球化学来开发的，以更好地识别和关联Icod（七个子单元）和El Golfo（五个子单元）事件床的一些核心示例中的这些子单元。通过Itrax研究确定的亚单元变化也允许检查散装亚单元内的地球化学非均质性。这些不均匀性反映了来自单一来源的离散滑坡。钙成分（碳酸盐的替代物）的系统性减少表明，最初的海底塌陷导致侧翼后退失败，导致陆上塌陷的成分增加。然而，粒度和密度分选影响整体地球化学组成。来自阿加迪尔盆地Icod和El Golfo事件层亚单元的火山玻璃（由Eagle III μXRF分析确定）的地球化学表明，这些亚单元代表离散的单独故障。
Generation of tsunamis from submarine landslides is sensitive to several parameters such as their volume, failure mechanism and location of failure relative to sea level. These conditions are often difficult to resolve for past events. However, previous studies of turbidites generated from landslides offer insight into the timing, total event volume and failure mechanism. This study confirms the ~ 165 ka Icod landslide originating from the northern flank of Tenerife as a retrogressive multistage landslide. It also shows that the latest volcanic flank collapse from the Canary Islands, the ~ 15 ka El Golfo landslide, is a retrogressive multistage failure. These inferences are developed using high resolution Itrax μXRF bulk geochemistry to better identify and correlate these subunits in a number of core examples of the Icod (seven subunits) and El Golfo (five subunits) event beds. Subunit variations identified through Itrax studies also allow examination of bulk intra-subunit geochemical heterogeneities. These heterogeneities reflect discrete landslides from a single source. A systematic decrease in calcium composition (proxy for carbonate) suggests initial submarine collapses that retrogressively fail the flank leading to an increasing component from subaerial collapses. However, both grain size and density sorting influence bulk geochemical compositions. The geochemistry of volcanic glasses (determined from Eagle III μXRF analyses) from the subunits of the Icod and El Golfo event beds from Agadir Basin demonstrate that these subunits represent discrete separate failures.
西非佛得角群岛侧翼塌陷和大规模山体滑坡
影响因子：
3.7
作者：
Masson;T.P LeBas;I. Grevemeyer;W. Weinrebe
通讯作者：
W. Weinrebe