DOI: 10.1016/j.quascirev.2015.11.010
Scopus记录号: 2-s2.0-84948737275
论文题名: Late Pleistocene and Holocene aeolian sedimentation in Gonghe Basin, northeastern Qinghai-Tibetan Plateau: Variability, processes, and climatic implications
作者: Qiang M. ; Jin Y. ; Liu X. ; Song L. ; Li H. ; Li F. ; Chen F.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2016
卷: 132 起始页码: 57
结束页码: 73
语种: 英语
英文关键词: Aeolian activity
; China
; Climatic change
; Gonghe Basin
; Luminescence dating
; Sand accumulation
; Sediment supply
; Vegetation condition
Scopus关键词: Climate change
; Deposition
; Deposits
; Evapotranspiration
; Luminescence
; Moisture
; Sediments
; Stratigraphy
; Vegetation
; Aeolian activities
; China
; Climatic changes
; Gonghe Basin
; Luminescence dating
; Sand accumulation
; Sediment supply
; Vegetation condition
; Sand
; accumulation rate
; bioaccumulation
; climate change
; climate variation
; eolian process
; grain size
; Holocene
; paleoenvironment
; paleosol
; Pleistocene
; precipitation (chemistry)
; sand
; China
; Qinghai-Xizang Plateau
英文摘要: Although stratigraphic sequences of aeolian deposits in dryland areas have long been recognized as providing information about past environments, the exact nature of the environmental processes they reflect remains unclear. Here, we report the results of a detailed investigation of eight outcrop sections in the Gonghe Basin, northeastern Qinghai-Tibetan Plateau. Measurements of sediment grain-size and chemical composition indicate that the deposits are primarily of aeolian origin, consisting of interbedded, well-sorted sand, silty sand, loess and/or palaeosol; however, their occurrence varies from site to site. Fossil dune sands mainly occur in or close to the currently stabilized or semi-stabilized dune fields, whereas loess is distributed along the downwind marginal areas. This pattern of basin-scale differentiation was controlled mainly by spatial variability of sediment supply due to the antecedent sedimentary patterns within the basin. Together with previously-published optically stimulated luminescence (OSL) ages, 24 new OSL dates are used to elucidate the history of aeolian activity and its relationship to climatic changes. There is no apparent relationship between past dune activity and downwind loess deposits. Deposition of silty sand probably occurred during past phases of windy, dry and cold climate in the Late Pleistocene. However, climatic factors alone cannot explain the occurrence of silty sand deposition. This is because the deposition of silty sand was always preceded by episodes of fluvial deposition prior to river incision, thereby indicating the importance of an 'activated' sediment supply associated with fluvial processes. Deposition of well-sorted sand occurred episodically, not only during the Late Pleistocene, but also during the early- to mid-Holocene. Vegetation conditions, controlled either by the occurrence of intervals of moisture deficit during the Late Pleistocene or by changes in the balance between precipitation and evapotranspiration at a local scale, played an important role in sand mobility and deposition. The effect of vegetation on sand mobility is also suggested by independent evidence of aeolian activity from Genggahai Lake in the Gonghe Basin. Here, the deposition of aeolian sand in the basin during the early- to mid-Holocene indicates a low level of effective moisture caused by high evaporation induced by higher summer insolation, despite the coeval increased regional precipitation recorded by lacustrine sediments. In contrast, late Holocene palaeosols represent a high level of effective moisture, and their formation did not necessarily require increased regional precipitation. Overall, our results suggest that the relationship between aeolian activity and regional climate change is complex, and that sand accumulations do not represent the consistent action of surface processes that are related to climatic changes. © 2015 The Authors.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59703
Appears in Collections: 过去全球变化的重建
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作者单位: MOE Key Laboratory of Western China's Environmental Systems, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, China; State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China; Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang, China
Recommended Citation:
Qiang M.,Jin Y.,Liu X.,et al. Late Pleistocene and Holocene aeolian sedimentation in Gonghe Basin, northeastern Qinghai-Tibetan Plateau: Variability, processes, and climatic implications[J]. Quaternary Science Reviews,2016-01-01,132