A Eurasian Basin sedimentary record of glacial impact on the central Arctic Ocean during MIS 1–4
A Eurasian Basin sedimentary record of glacial impact on the central Arctic Ocean during MIS 1–4
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MIS 1-4期间冰川对北冰洋中部影响的欧亚盆地沉积记录
DOI：
10.1016/j.gloplacha.2022.103993
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发表时间：
2022
影响因子：
3.9
通讯作者：
Chunjuan Wang
中科院分区：
文献类型：
--
作者：
Linsen Dong;Leonid Polyak;Xiaotong Xiao;Stefanie Brachfeld;Yanguang Liu;Xuefa Shi;Xisheng Fang;Yazhi Bai;Aimei Zhu;Chaoxin Li;Song Zhao;Dong Wu;Chunjuan Wang
北冰洋盆地明显的第四纪环流和沉积变化仍然知之甚少。本文研究了罗蒙诺索夫海脊外欧亚阿蒙森盆地ARC5-ICE4 （ICE4）沉积物岩心，重建了沉积物来源和环流的冰期-间冰期变率。ICE4记录具有不同的岩性，包括不同的冰川沉积和冰筏碎屑（IRD）。有机碳14c与古地磁资料的结合以及与较早地层的对比限制了沉积物的年龄。推导出的沉积速率为几厘米/千厘米（平均6.5厘米/千厘米），与区域地球物理资料的估计相一致。建立的年龄模式涵盖了大约10 ~ 75 ka的时间间隔，包括晚期和中期魏希塞勒/威斯康星冰期。各自的冰川沉积物主要是由脉冲冰山流沉积的。末次盛冰期和去冰作用表现在包括劳伦泰德冰盖矿物代用物在内的尖锐的IRD峰上，具有明显的千年尺度变率。以西伯利亚物源为主的较老冰期沉积单元形成于中魏希期（MIS 4/3）欧亚冰原脱冰期。这些沉积差异表明两个冰期对北冰洋的不同影响，包括冰盖大小/几何形状和海洋环流。
Pronounced Quaternary circulation and depositional changes in the Arctic Ocean basins remain poorly understood. We investigate sediment core ARC5-ICE4 (ICE4) in the Eurasian (Amundsen) Basin off the Lomonosov Ridge to reconstruct glacial-interglacial variability in sediment sources and circulation. The ICE4 record features variable lithologies including distinct glacigenic deposits with Ice Rafted Debris (IRD). The sediment age is constrained by a combination of the organic carbon14C with paleomagnetic data and correlation to earlier developed stratigraphies. The derived sedimentation rates constitute several cm/kyr (6.5 cm/kyr average) consistent with estimates from regional geophysical data. The developed age model covers the time interval from ca. 10 to 75 ka including Late and Middle Weichselian/Wisconsinian glaciations. Respective glacigenic sediments were primarily deposited by pulsed iceberg discharge. The Last Glacial Maximum and deglaciation is expressed in sharp IRD peaks including mineral proxies of the Laurentide Ice Sheet with an apparent millennial-scale variability. The older glacigenic sedimentary unit with abundant IRD of predominantly Siberian provenance was deposited during deglaciation of the Middle Weichselian (MIS 4/3) Eurasian Ice Sheet. These sedimentary differences indicate diverging impacts of the two glaciations on the Arctic Ocean, including ice-sheet sizes/geometries and oceanic circulation.