DOI: 10.5194/cp-10-91-2014
Scopus记录号: 2-s2.0-84892604510
论文题名: Sediment transport processes across the Tibetan Plateau inferred from robust grain-size end members in lake sediments
作者: Dietze E. ; Maussion F. ; Ahlborn M. ; Diekmann B. ; Hartmann K. ; Henkel K. ; Kasper T. ; Lockot G. ; Opitz S. ; Haberzettl T.
刊名: Climate of the Past
ISSN: 18149324
出版年: 2014
卷: 10, 期: 1 起始页码: 91
结束页码: 106
语种: 英语
Scopus关键词: catchment
; depositional environment
; environmental conditions
; grain size
; lacustrine deposit
; paleoenvironment
; phenology
; precipitation (climatology)
; proxy climate record
; reconstruction
; saltation
; sediment transport
; sediment trap
; sedimentation
; China
; Qinghai-Xizang Plateau
英文摘要: Grain-size distributions offer powerful proxies of past environmental conditions that are related to sediment sorting processes. However, they are often of multimodal character because sediments can get mixed during deposition. To facilitate the use of grain size as palaeoenvironmental proxy, this study aims to distinguish the main detrital processes that contribute to lacustrine sedimentation across the Tibetan Plateau using grain-size end-member modelling analysis. Between three and five robust grain-size end-member subpopulations were distinguished at different sites from similarly-likely end-member model runs. Their main modes were grouped and linked to common sediment transport and depositional processes that can be associated with contemporary Tibetan climate (precipitation patterns and lake ice phenology, gridded wind and shear stress data from the High Asia Reanalysis) and local catchment configurations. The coarse sands and clays with grain-size modes >250 μm and <2 μm were probably transported by fluvial processes. Aeolian sands (∼200 μm) and coarse local dust (∼60 μm), transported by saltation and in near-surface suspension clouds, are probably related to occasional westerly storms in winter and spring. Coarse regional dust with modes ∼25 μm may derive from near-by sources that keep in longer term suspension. The continuous background dust is differentiated into two robust end members (modes: 5-10 and 2-5 μm) that may represent different sources, wind directions and/or sediment trapping dynamics from long-range, upper-level westerly and episodic northerly wind transport. According to this study grain-size end members of only fluvial origin contribute small amounts to mean Tibetan lake sedimentation (19± 5%), whereas local to regional aeolian transport and background dust deposition dominate the clastic sedimentation in Tibetan lakes (contributions: 42 ± 14% and 51 ± 11%). However, fluvial and alluvial reworking of aeolian material from nearby slopes during summer seems to limit end-member interpretation and should be crosschecked with other proxy information. If not considered as a stand-alone proxy, a high transferability to other regions and sediment archives allows helpful reconstructions of past sedimentation history. © 2014 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49324
Appears in Collections: 气候变化与战略
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Recommended Citation:
Dietze E.,Maussion F.,Ahlborn M.,et al. Sediment transport processes across the Tibetan Plateau inferred from robust grain-size end members in lake sediments[J]. Climate of the Past,2014-01-01,10(1)