The ELSA-Flood-Stack: A reconstruction from the laminated sediments of Eifel maar structures during the last 60 000 years
The ELSA-Flood-Stack: A reconstruction from the laminated sediments of Eifel maar structures during the last 60 000 years
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DOI：
10.1016/j.gloplacha.2015.12.003
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发表时间：
2016-07-01
影响因子：
3.9
通讯作者：
Albert, J.
中科院分区：
文献类型：
--
作者：
Brunck, H.;Sirocko, F.;Albert, J.
本文利用全新世艾菲尔马尔湖和更新世干马尔构造沉积物岩心的事件层重建了中欧的主要洪水期。这些重建与最近的测量时间序列相结合，覆盖了过去6万年的整个极端降水。一般来说，由于maar湖的深水是季节性缺氧的，因此生物扰动较低，因此Eifel maar沉积物非常适合保存事件层。然而，年层压的保存仅在Holzmaar和Ulmener Maar保存；其他岩心的年代由碳-14、磁地层学、岩心标记物和冰芯校正确定。这些岩心是在德国中西部的艾菲尔地区钻探的，该地区代表了从比利时到波兰以及整个中欧的气候同质区域。在所有分析的岩心中，共检测到233个超过7.5毫米的洪水层。洪水事件的地层分类遵循新定义的景观演化带（LEZ）。全新世最强的事件发生在LEZ 1 （0 ~ 6000 b2k）的658、2800和4100 b2k年。lez2的洪水层（6000- 10500 b2k）不像lez1那样频繁，但洪水集中在6000- 6500b2k之间。在LEZ 3 （10 500-14 700 b2k）共发现20个洪水层；11个在LEZ 4 (14 700-21 000 b2k)；lez5 15个（21 000-28 500 b2k）；lez6 34 (28 500-36 500 b2k)；8在lez7 (36 500-49 000 b2k)；LEZ 8 （49 000-55 000 b2k）和LEZ 9 （55 000-60 000 b2k）为零。更新世的最大洪水期分别为11 500 ~ 17 500年（晚冰期和新仙女木期）、23 000 ~ 24 000年（格陵兰间冰期前）、29 000 ~ 35 000年（尤其是5 ~ 4间）和44 000 ~ 44 500 b2k（12 ~ 11过渡期）。洪水动态的变化是由气候驱动的，主要与气候转变和较冷时期有关，并与轻植被有关。结果表明，晚全新世以来与格陵兰基准期和人为影响相关的低植被覆盖度是maar沉积物中洪水层发育的主要原因。降水本身只起次要作用。这一解释是基于目前对冷期气候的理解和与植被覆盖有关的河流侵蚀的几项研究。(C) 2016 Elsevier B.V.版权所有
This study reconstructs the main flood phases in central Europe from event layers in sediment cores from Holocene Eifel maar lakes and Pleistocene dry maar structures. These reconstructions are combined with recent gauge time-series to cover the entire precipitation extremes of the last 60 000 years. In general, Eifel maar sediments are perfectly suited for the preservation of event layers since the deep water in the maar lakes is seasonal anoxic and therefore, bioturbation is low. However, the preservation of annual lamination is only preserved in Holzmaar and Ulmener Maar; the other cores are dated by C-14, magnetostratigraphy, tephra markers and ice core tuning. The cores were drilled in the Eifel region of central western Germany, which represents a climatic homogenous region from Belgium to Poland and all across Central Europe.A total of 233 flood layers over 7.5 mm were detected in all analysed cores. The stratigraphic classification of the flood events follows the newly defined Landscape Evolution Zones (LEZ). The strongest events in the Holocene have occurred during LEZ 1 (0-6000 b2k) in the years 658, 2800 and 4100 b2k. Flood layers in the LEZ 2 (6000-10 500 b2k) are not as frequent as during the LEZ 1, nevertheless, the floods cluster between 6000 and 6500 b2k. Twenty flood layers are found in the LEZ 3 (10 500-14 700 b2k); 11 in LEZ 4 (14 700-21 000 b2k); 15 in LEZ 5 (21 000-28 500 b2k); 34 in LEZ 6 (28 500-36 500 b2k); 8 in LEZ 7 (36 500-49 000 b2k); zero in LEZ 8 (49 000-55 000 b2k) and LEZ 9 (55 000-60 000 b2k). The maximum flood phases during the Pleistocene are at 11 500-17 500 (late glacial and Younger Dryas), 23 000-24 000 (before Greenland Interstadial (GI) 2), 29 000-35 000 (especially between GI 5 and 4) and 44 000-44 500 b2k (transition from GI 12 to 11).The variations in flood dynamics are climatically driven and mainly associated with climate transitions and colder periods, combined with light vegetation. It turns out that low vegetation coverage related to both Greenland Stadial phases and anthropogenic impacts since late Holocene is the main cause for the development of flood layers in maar sediments. The precipitation itself, plays only a secondary role. This interpretation is based on the current climate understanding of cold phases and several studies of fluvial erosion related to vegetation coverage. (C) 2016 Elsevier B.V. All rights reserved.