Evidence from Svalbard for near-freezing temperatures and climate oscillations in the Arctic during the Paleocene and Eocene
Evidence from Svalbard for near-freezing temperatures and climate oscillations in the Arctic during the Paleocene and Eocene
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DOI：
10.1016/j.palaeo.2009.04.012
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发表时间：
2009-07
期刊：
影响因子：
--
通讯作者：
R. Spielhagen;A. Tripati
中科院分区：
文献类型：
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作者：
R. Spielhagen;A. Tripati
直到最近，北极被认为是以整个新生代相对温暖的条件为特征的。然而，最近对包括北冰洋在内的北部高纬度地区深海钻探岩心的调查得出了明显相反的结果。本文报道了斯瓦尔巴特群岛早第三纪沉积序列中某些温度指标的间歇性出现，这可能是第一次直接记录到早新生代北方高纬度地区的冷水温度。其他细粒沉积物中的绿泥石(六水碳酸钙之后的方解石假象)和反常岩石需要接近冰点的温度和至少季节性海冰的存在。这一序列还包括煤层和其他温暖气候指标，但不在相同的地层水平上。这些结果表明，在古新世和始新世的温暖背景气候中，冷期的出现是间歇性的，这表明北极温度的变异性比以前认识到的要大得多。
Until recently, the Arctic was assumed to be characterised by relatively warm conditions throughout the Early Cenozoic. However, recent investigations on deep-sea drilling cores from northern high latitudes, including the Arctic Ocean, give apparently contradicting results. Here we report the intermittent occurrence of certain temperature indicators in the Early Tertiary sedimentary sequence on Svalbard, which may represent the first direct northern high-latitude record of cold water temperatures for the early Cenozoic. Glendonites (calcite pseudomorphs after calcium carbonate hexahydrate) and erratics in otherwise fine-grained sediments require near-freezing temperatures and the presence of at least seasonal sea ice. This succession also contains coal seams and other warm climate indicators, but not on the same stratigraphical levels. These results imply the occurrence of cooling phases episodically during the warm background climate of the Paleocene and Eocene, suggesting that Arctic temperature variability was much greater than previously recognized.