Late Saalian and Eemian palaeoenvironmental history of the Bol'shoy Lyakhovsky Island (Laptev Sea Region, Arctic Siberia)
Late Saalian and Eemian palaeoenvironmental history of the Bol'shoy Lyakhovsky Island (Laptev Sea Region, Arctic Siberia)
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DOI：
10.1080/03009480410001974
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发表时间：
2004-12-01
期刊：
影响因子：
2.2
通讯作者：
Kunitsky, VV
中科院分区：
文献类型：
--
作者：
Andreev, AA;Grosse, G;Kunitsky, VV
多年冻土序列的古环境记录，辅以Bolshoy Lyakhovsky岛（73 ° 20 'N，141 ° 30' E）的红外释光（IRSL）和Th-230/U测年，记录了该地区至少200 ka以来的环境历史。花粉光谱和昆虫区系表明，相对潮湿的草苔苔原生境占主导地位，在一个interstadial c。200-170 ka BP。夏季相当温暖潮湿，而稳定同位素则反映了严酷的冬季条件。花粉光谱反映了Taz（萨利安晚期）阶段c.时期较稀疏的草苔植被。170-130 ka BP，环境条件比以前的海间海更为严峻。开放的禾本科和蒿属植物协会占主导地位的植被在开始的卡赞采沃（Eemian）c。距今约13万年。一些灌木（赤杨，柳，矮桦）生长在更保护和潮湿的地方。在这段时间里，气候相对温暖，导致萨利亚冰楔融化。后来，在间冰期的最佳时期，灌木苔原与赤杨和矮桦s.l.占主导地位的植被。气候相对湿润温暖。基于花粉的定量气候重建表明，在Eemian的最佳时期，7月平均气温比现在高4-5 ℃，而Eemian晚期的记录表明气候显著恶化。
Palaeoenvironmental records from permafrost sequences complemented by infrared stimulated luminescence (IRSL) and Th-230/U dates from Bolshoy Lyakhovsky Island (73degrees20'N, 141degrees30'E) document the environmental history in the region for at least the past 200 ka. Pollen spectra and insect fauna indicate that relatively wet grasssedge tundra habitats dominated during an interstadial c. 200-170 ka BP. Summers were rather warm and wet, while stable isotopes reflect severe winter conditions. The pollen spectra reflect sparser grass-sedge vegetation during a Taz ( Late Saalian) stage, c. 170-130 ka BP, with environmental conditions much more severe compared with the previous interstadial. Open Poaceae and Artemisia plant associations dominated vegetation at the beginning of the Kazantsevo ( Eemian) c. 130 ka BP. Some shrubs ( Alnus fruticosa, Salix, Betula nana) grew in more protected and wetter places as well. The climate was relatively warm during this time, resulting in the melting of Saalian ice wedges. Later, during the interglacial optimum, shrub tundra with Alnus fruticosa and Betula nana s.l. dominated vegetation. Climate was relatively wet and warm. Quantitative pollen-based climate reconstruction suggests that mean July temperatures were 4-5 C higher than the present during the optimum of the Eemian, while late Eemian records indicate significant climate deterioration.