DOI: 10.1016/j.palaeo.2017.08.009
论文题名: Hydrogen isotope ratios of leaf wax n-alkanes in loess and floodplain deposits in northern China since the Last Glacial Maximum and their paleoclimatic significance
作者: Li Y. ; Yang S. ; Xiao J. ; Jiang W. ; Yang X.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2017
语种: 英语
英文关键词: Compound-specific hydrogen isotope composition
; East Asian Summer Monsoon
; Holocene
; Last Glacial Maximum
; n-Alkanes
英文摘要: The hydrogen isotopic composition of leaf-wax n-alkanes (δDn-alkane) is increasingly used as a proxy for estimating δD of past precipitation (δDp). However, aridity can also affect sedimentary δDn-alkane, complicating the interpretation of paleo-δDn-alkane records. In order to evaluate the effects of the complex interactions and balance between precipitation hydrogen isotope composition and aridity on sedimentary δDn-alkane records, we present two δDn-alkane records from the North China Plain and the western Chinese Loess Plateau across a steep east-west climatic gradient in the East Asian Summer Monsoon area since the Last Glacial Maximum. The estimated δDp changes, based on a present-day relationship between δDp and rainfall amounts, can explain much of the δDn-alkane variations in the North China Plain, but do not explain the large variations of δDn-alkane in the western Chinese Loess Plateau. Comparison of δDn-alkane records with observed δDn-alkane values in modern plants and published pollen data indicates that changes in vegetation play a minor role in the variations of δDn-alkane. Instead, δDn-alkane values are coincident with aridity both temporally and spatially, i.e. the higher δDn-alkane values the drier climate and vice versa. Aridity effects are more evident in the western Chinese Loess Plateau than in the North China Plain. Therefore, on glacial-interglacial scale, sedimentary δDn-alkane records from the North China Plain mostly reflect changes in δDp values, whereas those from the western Chinese Loess Plateau largely reflect the effects of aridity, mainly due to a greater evapotranspirational deuterium-enrichment caused by a drier climate in the western Chinese Loess Plateau than in the North China Plain. Further calibrations from modern sediments are required to better define the quantitative relationship between the δDn-alkane and climate in northern China. © 2017 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68069
Appears in Collections: 过去全球变化的重建
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作者单位: Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China
Recommended Citation:
Li Y.,Yang S.,Xiao J.,et al. Hydrogen isotope ratios of leaf wax n-alkanes in loess and floodplain deposits in northern China since the Last Glacial Maximum and their paleoclimatic significance[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2017-01-01