Holocene sea levels, Last Glacial Maximum glaciomarine environments and geophysical models in the northern Irish Sea Basin, UK
Holocene sea levels, Last Glacial Maximum glaciomarine environments and geophysical models in the northern Irish Sea Basin, UK
复制标题
英国北爱尔兰海盆地全新世海平面、末次盛冰期冰川海洋环境和地球物理模型
DOI：
10.1016/j.margeo.2006.05.005
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发表时间：
2006
期刊：
影响因子：
2.9
通讯作者：
S. González
中科院分区：
文献类型：
--
作者：
D. Roberts;R. Chiverrell;J. Innes;B. Horton;A. Brooks;G. Thomas;S. Turner;S. González
新获得的地质记录从马恩岛揭示了插入潮间带和陆地沉积物，记录了相对海平面上升，从约。-3.86米，全新世早期至全新世中期最大值，约为100米。6.6和4.5 cal kyr BP。+2.25米。当与类似的海洋记录从其他地方在北方爱尔兰海盆地，海平面数据证实了强大的南北趋势的冰川均衡加载，但很少东西加载的差异。这种模式的结果从中央北方部门的英国冰盖苏格兰强烈影响整个北方爱尔兰海盆地的冰川均衡下沉。爱尔兰海、湖区和爱尔兰的冰厚差异并没有引起当地冰川均衡特征的扰动。在爱尔兰海中部的全新世海洋数据记录在全新世早期全球海平面上升的缓慢终止。相对海平面的地球物理预测部分受到全新世RSL观测的限制，但外推到末次冰期最大期，显示爱尔兰海盆中部和爱尔兰东北部在大约10年之间存在浅海条件的潜力。21.0-16.0 cal kyr BP。然而，在东北部爱尔兰的冰海沉积物表明模型相对海平面的预测太低，并需要增加冰负荷或更薄的岩石圈，以产生额外的冰川均衡抑郁症在冰川消退的时候。此外，预测的东北部爱尔兰冰消期相对海平面不匹配的地质记录，突出复杂的冰缘/海洋在冰消期的相互作用。在马恩岛，那里的冰川均衡负荷是一个类似的幅度，整个东北部爱尔兰，存在的地面冰抑制海洋入侵在早期冰消期，但发生的冰川湖泊条件沿着冰缘，因为它向北移动支持模型预测，相对海平面下降到现在以下的晚冰期/全新世早期由于快速冰川均衡反弹。
Newly acquired geological records from the Isle of Man reveal intercalated intertidal and terrestrial sediments that record a relative sea-level rise from ca. −3.86 m in the early Holocene up to a mid-Holocene maximum between ca. 6.6 and 4.5 cal kyr BP at ca. +2.25 m. When compared with similar marine records from elsewhere in the northern Irish Sea Basin, the sea-level data confirm a strong north–south trend in glacioisostatic loading, but little east to west difference in loading. This pattern results from the central northern sectors of the British ice sheet over Scotland strongly influencing the glacioisostatic downwarping throughout the northern Irish Sea Basin. Differential ice thicknesses over the Irish Sea, the Lake District and Ireland did not cause perturbations of local glacioisostatic signatures. The Holocene marine data in the central Irish Sea record a slow termination of global eustatic sea-level rise during the early Holocene. Geophysical predictions of relative sea level, partially constrained by the Holocene RSL observations but extrapolated to the Last Glacial Maximum, show the potential for shallow marine conditions in the central Irish Sea Basin and in northeast Ireland between ca. 21.0–16.0 cal kyr BP. However, glaciomarine deposits in northeast Ireland suggest the model relative sea-level predictions are too low, and require increased ice loading or a thinner lithosphere to generate extra glacioisostatic depression at the time of deglaciation. Furthermore, predicted deglacial relative sea level for northeast Ireland does not match the geological record, highlighting complex ice margin/ocean interaction during deglaciation. On the Isle of Man, where glacioisostatic loading is of a similar magnitude to that across northeast Ireland, the presence of grounded ice inhibited marine incursion during early deglaciation, but the occurrence of glaciolacustrine conditions along the ice margin as it moved northwards supports model predictions that relative sea-level fell below present during the Late Glacial/early Holocene due to rapid glacioisostatic rebound.