Early interglacial bottom-current sedimentation on the eastern Reykjanes Ridge
Early interglacial bottom-current sedimentation on the eastern Reykjanes Ridge
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雷克雅内斯海岭东部的早期间冰期底流沉积
DOI：
10.1016/0025-3227(76)90059-1
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发表时间：
1976
期刊：
影响因子：
--
通讯作者：
F. Bowles
中科院分区：
文献类型：
--
作者：
W. Ruddiman;F. Bowles
在雷克雅内斯山脊东部的三个岩心中检测到了最近两次冰川作用后异常的晚冰消期/早间冰期沉积率。形态学、结构和矿物学证据表明，底流是导致这些不寻常沉积速率的过程，沉积速率首先上升至区域平均值的 10-40 倍，然后略微下降至仍为正常值的 2-5 倍。这些岩心的间冰期沉积物中过量的黄铁矿的一部分是由于来自地面暴露和均衡隆起的冰岛玄武岩侵蚀的细碎屑的输入造成的。然而，在大多数情况下，冰消期晚期的异常沉积速率是由先前沉积的冰川沉积物的侵蚀和重新分布引起的。我们推断，由于挪威海冰盖的冰川消融，深水再次溢出进入大西洋，引发了强大的底部水流，将沉积物从暴露地点移走。因此，冰消期深层环流的强化在雷克雅内斯海岭东部的沉积物上留下了重要的沉积学印记。
Unusual late deglacial/early interglacial sedimentation rates following the last two glaciations have been detected from three cores on the eastern Reykjanes Ridge. Morphologic, textural, and mineralogic evidence pinpoint bottom currents as the process responsible for these unusual depositional rates, which rise at first to 10–40 times the regional mean, and then subside slightly to values still 2–5 times the norm. A portion of the lutite excesses in the interglacial sediment of these cores is accounted for by input of fine detritus eroded from subaerially exposed and isostatically uplifted Icelandic basalts. For the most part, however, the extraordinary depositional rates late in the deglacial periods are caused by erosion and redistribution of previously deposited glacialage sediments. We infer that reinitiation of overflow of deep water into the Atlantic due to deglacial removal of the Norwegian Sea ice cover triggered a strong bottom-current flow that dislodged sediment from exposed sites. The deglacial intensification of the deep circulation thus left a major sedimentological imprint on the sediments of the eastern Reykjanes Ridge.