Ice sheet extension to the Celtic Sea shelf edge at the Last Glacial Maximum
Ice sheet extension to the Celtic Sea shelf edge at the Last Glacial Maximum
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末次盛冰期，冰盖延伸至凯尔特海陆架边缘
DOI：
10.1016/j.quascirev.2014.12.010
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发表时间：
2015
影响因子：
4
通讯作者：
P. Coxon
中科院分区：
文献类型：
--
作者：
D. Praeg;S. Mccarron;D. Dove;C. Ó. Cofaigh;Gill Scott;X. Monteys;L. Facchin;R. Romeo;P. Coxon
先前对英国-爱尔兰冰盖（BIIS）的重建设想了在末次冰盛期从爱尔兰海到凯尔特海的冰流，限制了爱尔兰-英国部门的中间大陆架。我们提出的证据，从沉积物岩心和地球物理剖面的BIIS延伸150公里，更远的海到达大陆架边缘。最近从外科伯恩浅滩侧翼获得的三个岩芯，外科伯恩浅滩是一个横跨大陆架的沉积脊，终止于侵蚀的冰川生成层，包括两个相：超固结分层杂岩;和含有冷水亲和力的微型和大型化石物种的细层泥砂。我们解释这些相造成冰下变形和冰川沉积从浑浊的融水羽。冰海沉积物中一个有缺口但未磨损的软体动物瓣膜的年代为24，265 ± 195 cal BP，这表明当时从大陆架边缘撤出了一个冰筏冰盖边缘，这与25.5和23.4 ka BP之间凯尔特海物源的冰筏碎片峰的深海岩心证据一致。再加上陆地的证据，这支持快速（约2 ka）清洗的BIIS的冰流，先进的从爱尔兰海的大陆架边缘，并在海因里希事件2崩溃回来。
Previous reconstructions of the British–Irish Ice Sheet (BIIS) envisage ice streaming from the Irish Sea to the Celtic Sea at the Last Glacial Maximum, to a limit on the mid-shelf of the Irish-UK sectors. We present evidence from sediment cores and geophysical profiles that the BIIS extended 150 km farther seaward to reach the continental shelf edge. Three cores recently acquired from the flank of outer Cockburn Bank, a shelf-crossing sediment ridge, terminated in an eroded glacigenic layer including two facies: overconsolidated stratified diamicts; and finely-bedded muddy sand containing micro- and macrofossil species of cold water affinities. We interpret these facies to result from subglacial deformation and glacimarine deposition from turbid meltwater plumes. A date of 24,265 ± 195 cal BP on a chipped but unabraded mollusc valve in the glacimarine sediments indicates withdrawal of a tidewater ice sheet margin from the shelf edge by this time, consistent with evidence from deep-sea cores for ice-rafted debris peaks of Celtic Sea provenance between 25.5 and 23.4 ka BP. Together with terrestrial evidence, this supports rapid (ca 2 ka) purging of the BIIS by an ice stream that advanced from the Irish Sea to the shelf edge and collapsed back during Heinrich event 2.
贝叶斯模型对爱尔兰海冰流的消退进行建模
影响因子：
2.3
作者：
Chiverrell R
通讯作者：
Chiverrell R