Changes in terrestrial organic matter input to the Mendeleev Ridge, western Arctic Ocean, during the Late Quaternary
Changes in terrestrial organic matter input to the Mendeleev Ridge, western Arctic Ocean, during the Late Quaternary
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DOI：
10.1016/j.gloplacha.2009.03.012
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发表时间：
2009-07
影响因子：
3.9
通讯作者：
Masanobu Yamamoto;L. Polyak
中科院分区：
文献类型：
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作者：
Masanobu Yamamoto;L. Polyak
对2005年Healy-Oden横贯北极考察(HOTRAX‘05)期间在门捷列夫海脊采集的HLY0503-08JPC柱样晚更新世沉积物中的碳氢化合物和甘油二烷基甘油四醚(GDGT)进行了分析，以研究上一次完整的冰期旋回(约130 KYR)期间北冰洋西部的环境变化。长链正构烷烃和GDGT浓度的变化对应于交替的色带、棕色(间冰期/间冰期)和灰色(冰期/冰期)层。灰色层以丰富的高等植物正构烷烃和分枝GDGT为特征，这意味着陆地植物和土壤有机质(OM)在冰川环境中的贡献较大，可能是由于美洲冰川盆地冰川侵蚀的细粒产物沉积所致。来自成熟有机质的岩屑正构烷烃具有明显的峰，可分为六种类型，推测为不同的沉积物来源。一些峰值与欧亚大陆的前冰川湖泊和劳伦蒂冰盖的冰山排放和淡水爆发事件有关，这表明其他峰值可能对应于类似的事件。
Hydrocarbons and glycerol dialkyl glycerol tetraethers (GDGTs) were analyzed in Late Pleistocene sediments of Core HLY0503-08JPC collected at the Mendeleev Ridge during the Healy-Oden Trans Arctic Expedition 2005 (HOTRAX'05) to investigate environmental changes in the western Arctic Ocean during the last full glacial cycle, ca. 130 kyr. Variations in long-chain n-alkane and GDGT concentrations correspond to alternated color banding, brown (interglacial/interstadial) and grayish (glacial/stadial) layers. Grayish layers are characterized by abundant higher-plant n-alkanes and branched GDGTs, implying larger contribution of terrestrial plant and soil organic matter (OM) in glacial environments, possibly due to the deposition of fine-grained products of glacial erosion in the Amerasian basin. Lithic n-alkanes derived from mature OM show pronounced peaks, which can be classified into six types presumably indicative of various sediment sources. Some peaks are correlated to events of iceberg discharge and freshwater outbursts from proglacial lakes of the Eurasian and, possibly, Laurentide ice sheets, suggesting that other peaks may correspond to similar events.