Radiocarbon Dating of Leaf Waxes in the Loess-Paleosol Sequence Kurtak, Central Siberia
Radiocarbon Dating of Leaf Waxes in the Loess-Paleosol Sequence Kurtak, Central Siberia
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DOI：
10.1017/rdc.2017.1
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发表时间：
2017-02
期刊：
影响因子：
8.3
通讯作者：
M. Haas;M. Bliedtner;Igor Borodynkin;G. Salazar;S. Szidat;T. Eglinton;R. Zech
中科院分区：
文献类型：
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作者：
M. Haas;M. Bliedtner;Igor Borodynkin;G. Salazar;S. Szidat;T. Eglinton;R. Zech
黄土-古土壤序列是第四纪气候环境变化的重要档案。到目前为止，LPS通常使用发光法测年，不确定性约为10%，或者在极少数情况下使用放射性碳（14 C）分析，木炭或大型化石可用。在这项研究中，我们确定了14 C年龄的叶蜡（长链正构烷烃）从LPS Kurtak在西伯利亚中部。末次冰期黄土的14 C年龄范围为16.7 - 22.9 ka cal BP，与海洋同位素阶段（MIS）3相关的古土壤的14 C年龄范围为24.5 - 35.3 ka cal BP。总的来说，这是在良好的协议与独立的年龄控制的基础上，地层，红外释光（IRSL）测年，碳和宏体化石的14 C测年。然而，在MIS 2早期，强烈的冷扰动和土壤扰动似乎已经影响了MIS 3古土壤。我们的研究结果证实了地层的完整性，叶蜡，并强调其潜力的LPS追溯到~35-40 ka BP。与化合物特定的14 C分析相比，这是非常耗时的，需要专门的仪器（气相色谱仪与馏分收集器），14 C测年的叶蜡作为一个整体的化合物类是相对快速和直接的，值得进一步调查作为一个时间工具。
Abstract Loess-paleosol sequences (LPS) are valuable archives for Quaternary climate and environmental changes. So far, LPS are generally dated using luminescence, with ~10% uncertainties, or radiocarbon (14C) analyses in the rare cases that charcoal or macrofossils are available. For this study, we determined 14C ages of leaf waxes (long-chain n-alkanes) extracted from the LPS Kurtak in central Siberia. 14C ages range from 16.7 to 22.9 ka cal BP for the last glacial loess and from 24.5 to 35.3 ka cal BP for the paleosol correlated with marine isotope stage (MIS) 3. Overall, this is in good agreement with independent age control based on stratigraphy, infrared stimulated luminescence (IRSL) dating, and 14C dating on charcoal and macrofossils. However, strong cryoturbation and solifluction seem to have affected the MIS 3 paleosol early during MIS 2. Our results corroborate the stratigraphic integrity of leaf waxes, and highlight their potential for dating LPS back to ~35–40 ka BP. Compared to compound-specific 14C analyses, which are very time-consuming and require specialized instrumentation (gas chromatograph with fraction collector), 14C dating of leaf waxes as a whole compound class is relatively quick and straightforward and warrants further investigation as a chronological tool.