Cosmogenic exposure dating constraints for coastal landslide evolution on the Island of Malta (Mediterranean Sea)
Cosmogenic exposure dating constraints for coastal landslide evolution on the Island of Malta (Mediterranean Sea)
复制标题
马耳他岛（地中海）沿海滑坡演化的宇宙成因暴露测年限制
DOI：
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发表时间：
2018
影响因子：
2.1
通讯作者：
K. Fifield
中科院分区：
文献类型：
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作者：
M. Soldati;Timothy T. Barrows;M. Prampolini;K. Fifield
对影响马耳他岛西北海岸的滑坡进行了10年的调查和监测。水深测量的结果是，发现这些矿床一直延伸到海底，因此对它们的形成时间提出了疑问。此外，它们是在何种环境中发展起来的，哪些因素控制着它们的运动，这些都是不确定的。本文的目的是调查代表性的determines来限制这些群众运动事件的时间顺序，并勾勒出他们的空间和时间演变。暴露测年使用宇宙成因核素36Cl的样品收集头陡坎和块位于两个长期监测的滑坡，其特点是广泛的块幻灯片。结果表明，最古老的地块拆离发生在约2000年的陆上环境中。21 ka，当时海平面比现在低130 m左右。在冰后期海侵过程中，当海平面达到滑坡趾时，可能加速了滑坡体的运动。考虑到块体运动的时间，今天观察到的滑坡沉积物似乎与涉及大部分斜坡的第一次失败有关，尽管这里也考虑了替代假设。这一主要事件很可能是继二次运动的影响脚趾底切和粘土饱和，由于海平面上升。然而，需要进一步研究群众运动运动学，以模拟其演变，并探讨这种解释是否广泛适用于沿着马耳他海岸。
Landslides affecting the north-western coast of the Island of Malta have been investigated and monitored for 10 years. As a result of a bathymetric survey, it was discovered the deposits continued out onto the seafloor, thus raising questions as to the timing of their development. Furthermore it was uncertain as to which environment they developed in and which factors controlled their movements. The aim of this paper is to investigate representative detachments to chronologically constrain these mass movement events and outline their spatial and temporal evolution. Samples for exposure dating using the cosmogenic nuclide 36Cl were collected from head scarps and blocks located within two long-term monitored landslides characterised by extensive block slides. The results indicate the oldest dated block detachment occurring in a subaerial environment at ca. 21 ka, when the sea level was about 130 m lower than at present. Mass movement possibly accelerated when sea level reached the landslide toe during the post-glacial marine transgression. Considering the timing of block movement, the landslide deposits observed today appear to be related to a first-time failure involving a large part of the slope, though and alternative hypothesis is also taken here into account. This main event is likely to have been followed by secondary movements influenced by toe undercutting and clay saturation due to rising sea level. However, further research on mass movement kinematics is required in order to model their evolution and explore whether this interpretation is widely applicable along the Maltese coast.