Ice Complex formation in arctic East Siberia during the MIS3 Interstadial
Ice Complex formation in arctic East Siberia during the MIS3 Interstadial
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DOI：
10.1016/j.quascirev.2013.11.009
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发表时间：
2014-01
影响因子：
4
通讯作者：
S. Wetterich;V. Tumskoy;N. Rudaya;A. Andreev;T. Opel;H. Meyer;Lutz Schirrmeister;Matthias Hüls
中科院分区：
文献类型：
--
作者：
S. Wetterich;V. Tumskoy;N. Rudaya;A. Andreev;T. Opel;H. Meyer;Lutz Schirrmeister;Matthias Hüls
研究人员对 Bol'shoy Lyakhovsky 岛（新西伯利亚群岛，德米特里·拉普捷夫海峡）南部海岸的热环中暴露的连续 15 米长的冰复合永久冻土层（Yedoma）进行了研究，以重建过去的景观和环境动态。该序列在海洋同位素第 3 阶段 (MIS3) Interstadial 期间在冰楔多边形中 >49 至 29 ka BP 之间积累。对冷冻沉积物进行了冰石学描述，并在两个冰楔之间的垂直悬崖上取样。根据沉积学和年代学资料，将剖面细分为与MIS3早、中、晚期环境条件相关的三个单元。孢粉学数据支持这种分层。多边形结构中纹理冰的稳定同位素特征反映了由于局部冻融过程引起的分馏，而大约 5 m 宽和超过 17 m 高的冰楔的特征非常适合区域稳定水同位素记录。 MIS3 期间的区域气候动态 多边形图案地面的场间和当地景观条件控制了冰复合体的形成。这里展示的序列完成了先前发布的西伯利亚东北部 MIS3 永久冻土记录。北极西白令陆桥的晚第四纪场间气候变化在冰复合体中以千年分辨率保存。 Bol'shoy Lyakhovsky 岛上的冰复合体揭示了距今 48 至 38 ka 之间的 MIS3 气候最佳值。
A continuous 15 m long sequence of Ice Complex permafrost (Yedoma) exposed in a thermo-cirque at the southern coast of Bol'shoy Lyakhovsky Island (New Siberian Archipelago, Dmitry Laptev Strait) was studied to reconstruct past landscape and environmental dynamics. The sequence accumulated during the Marine Isotope Stage 3 (MIS3) Interstadial between >49 and 29 ka BP in an ice-wedge polygon. The frozen deposits were cryolithologically described and sampled on a vertical bluff between two ice wedges. According to sedimentological and geochronological data, the section is subdivided into three units which correlate with environmental conditions of the early, middle, and late MIS3 period. Palynological data support this stratification. The stable isotope signature of texture ice in the polygon structure reflects fractionation due to local freeze–thaw processes, while the signature of an approximately 5 m wide and more than 17 m high ice wedge fits very well into the regional stable-water isotope record. Regional climate dynamics during the MIS3 Interstadial and local landscape conditions of the polygonal patterned ground controlled the Ice Complex formation. The sequence presented here completes previously published MIS3 permafrost records in Northeast Siberia. Late Quaternary stadial-interstadial climate variability in arctic West Beringia is preserved at millennial resolution in the Ice Complex. A MIS3 climate optimum was revealed between 48 and 38 ka BP from the Ice Complex on Bol'shoy Lyakhovsky Island.