Glacial/interglacial Cycles in the Norwegian Sea: Sedimentology, Paleoceanography, and Evolution of Late Pliocene to Quaternary Northern Hemisphere Climate
Glacial/interglacial Cycles in the Norwegian Sea: Sedimentology, Paleoceanography, and Evolution of Late Pliocene to Quaternary Northern Hemisphere Climate
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挪威海的冰期/间冰期旋回：沉积学、古海洋学和上新世晚期到第四纪北半球气候的演化
DOI：
10.2973/odp.proc.sr.104.116.1989
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发表时间：
1989
期刊：
影响因子：
2.9
通讯作者：
R. Henrich
中科院分区：
文献类型：
--
作者：
R. Henrich
长期记录的冰期/间冰期循环表明，在挪威海的三个主要的古海洋学制度。自2.56 Ma斯堪的纳维亚半岛第一次大冰期以来的时期，其特征是冰筏碎片输入的高频率，低振幅振荡，盐度降低，表层沃茨碳酸盐壳产量减少，以及海底碳酸盐溶解总体较强。这些条件表明，在北方半球的纬向环流模式和相对隔离的表层和底层沃茨在挪威海。总体上温和的冰川气候只是偶尔被温暖的大西洋沃茨的微弱入侵所打断。只有在644号地点才发现这些规模相当大的侵入体，因此只限于比以前更靠近挪威大陆架的地区。从1.2到0.6马的间隔的特点是增加碳酸盐壳生产和更好的保存，以及冰筏碎片输入的频率模式的变化。这种模式反映了在挪威海强冰川和温暖的间冰期之间的环流加强对比的增加。过去0.6 Ma的碳酸盐岩记录显示了以100-k.y.为主的高振幅振荡。频率模式ODP第104航次钻井区的冰川/间冰期沉积旋回揭示了各种特定的暗色岩相。这些黑暗的diamictons反映了激烈的冰山漂流在表面沃茨喂养的浪涌沿着前面的海洋为基础的部分，在挪威海东南部的大陆冰盖，并与再悬浮的化石有机碳和强烈的溶解在海底。在这些时期，沿着冰岛-法罗-苏格兰海脊沿着堆积的巨大冰山屏障可能部分阻断了地表水与北大西洋的联系。
The long-term record of glacial/interglacial cycles indicates three major paleoceanographic regimes in the Norwegian Sea. The period since the first major glaciation over Scandinavia at 2.56 Ma is characterized by high-frequency, low-amplitude oscillations of ice-rafted debris inputs, a lowered salinity, and decreased carbonate shell production in surface waters as well as overall strong carbonate dissolution at the sea floor. These conditions indicate a more zonal circulation pattern in the Northern Hemisphere and a relative isolation of surface and bottom waters in the Norwegian Sea. The generally temperate glacial climate was only interrupted by episodic weak intrusions of warm Atlantic waters. These intrusions have been detected in considerable magnitude only at Site 644, and thus are restricted to areas much closer to the Norwegian shelf than during earlier periods. The interval from 1.2 to 0.6 Ma is characterized by an increase in carbonate shell production and a better preservation, as well as a change in frequency patterns of ice-rafted debris inputs. This pattern reflects increasing meridionality in circulation-strengthening contrasts in the Norwegian Sea between strong glaciations and warm interglacials. The past 0.6 Ma reveal high-amplitude oscillations in carbonate records that are dominated by the 100-k.y. frequency pattern. Glacial/interglacial sedimentary cycles in the ODP Leg 104 drill sites reveal a variety of specific dark lithofacies. These dark diamictons reflect intense iceberg rafting in surface waters fed by surges along the front of marine-based parts of the continental ice sheets in the southeastern sector of the Norwegian Sea and are associated with resuspension of reworked fossil organic carbon and strong dissolution at the sea floor. Piling up of huge iceberg barriers along the Iceland-Faeroe-Scotland Ridge might have partially blocked off surface water connections with the North Atlantic during these periods.