230Th/U Dating of Frozen Peat, Bol'shoy Lyakhovsky Island (Northern Siberia)
230Th/U Dating of Frozen Peat, Bol'shoy Lyakhovsky Island (Northern Siberia)
复制标题
230Th/U 冷冻泥炭测年，Bolshoy Lyakhovsky 岛（西伯利亚北部）
DOI：
10.1006/qres.2001.2306
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发表时间：
2002
影响因子：
2.3
通讯作者：
M. Geyh
中科院分区：
文献类型：
--
作者：
Lutz Schirrmeister;D. Özen;M. Geyh
摘要 由于缺乏可靠的数值年龄测定，人们对西伯利亚东北部第四纪古环境和气候的年代学知之甚少。最好的气候档案是富含冰的永久冻土序列，广泛分布在西伯利亚东北部。在本研究中，通过热电离质谱 (TIMS) 对 Zimov'e 河以西 Bol'shoy Lyakhovsky 岛（新西伯利亚群岛）南崖永久冻土沉积物中的冷冻泥炭测定了 230Th/U 年龄。这些得出了前伊米亚纪“等时线”校正的 230Th/U 年龄为 200,900±3400 年。这个结果是可靠的，因为永久冻土沉积物对于铀和钍来说表现为封闭系统。我们的研究结果表明，对永久冻土沉积物中的冷冻泥炭进行 230Th/U 测年是重建西伯利亚北部和整个北极的中第四纪环境的有用工具。
Abstract The chronology of Quaternary paleoenvironment and climate in northeastern Siberia is poorly understood due to a lack of reliable numerical age determinations. The best climatic archives are ice-rich permafrost sequences, which are widely distributed in northeastern Siberia. For this study, 230Th/U-ages were determined by thermal ionization mass spectrometry (TIMS) from frozen peat in a permafrost deposit at the southern cliff of the Bol'shoy Lyakhovsky Island (New Siberian Archipelago), west of the Zimov'e River. These yielded a Pre-Eemian “isochron”-corrected 230Th/U-age of 200,900±3400 yr. This result is reliable because permafrost deposits behave as closed systems with respect to uranium and thorium. Our findings suggest that 230Th/U dating of frozen peat in permafrost deposits is a useful tool for the reconstruction of the Middle Quaternary environment of northern Siberia and of the whole Arctic.