DOI: 10.1016/j.quascirev.2016.07.013
Scopus记录号: 2-s2.0-84979200773
论文题名: Inferring LGM sedimentary and climatic changes in the southern Eastern Alps foreland through the analysis of a 14C ages database (Brenta megafan, Italy)
作者: Rossato S. ; Mozzi P.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2016
卷: 148 起始页码: 115
结束页码: 127
语种: 英语
英文关键词: Alluvial sedimentation
; European Alps
; LGM
; Paleoclimate
; Peat layers
; Radiocarbon dates database
; Venetian-Friulian alluvial plain
Scopus关键词: Climatology
; Database systems
; Glacial geology
; Sedimentation
; Sedimentology
; Stratigraphy
; Alluvial plains
; Alluvial sedimentation
; European Alps
; Paleoclimates
; Radiocarbon dates
; Peat
; alluvial deposit
; alluvial plain
; climate change
; climate forcing
; database
; floodplain
; glacier dynamics
; glaciofluvial deposit
; Last Glacial Maximum
; paleoclimate
; peatland
; proxy climate record
; radiocarbon dating
; sedimentation rate
; valley glacier
; Alps
; Eastern Alps
; Italy
英文摘要: The analysis of a database of radiocarbon ages is proposed as a tool for investigating major glaciofluvial systems of the Last Glacial Maximum (LGM) in the Alpine foreland, and their relations with glacier dynamics and climatic fluctuations. Our research concerns the Brenta megafan (NE Italy), where 110 radiocarbon dates integrate a robust regional stratigraphic and palaeoclimatic framework. Age-depth models allowed us to calculate sedimentation rates, while the time distribution of peat layers, which recurrently formed in this region during the LGM, were estimated through meta-analysis. The reliability of statistical results was carefully evaluated using Pearson and Spearman coefficients. Sedimentation rates in the Brenta megafan markedly fluctuated during LGM: ≈1.8 m/ka between 40 and 26.7 ka cal BP; ≈3 m/ka between 26.7 and 23.8 ka cal BP and ≈1.4 m/ka from 23.8 to 17.5 ka cal BP, when the distributary system deactivated due to fan-head trenching. This is evidence that sediment input and routing in the glaciofluvial distributary system was particularly efficient during the central part of LGM, when glaciers were stable at their outermost position. Meta-analysis indicates an increase in peat formation in correspondence with global (Heinrich Event 3 and/or the Greenland Interstadial 5.1 and 4 for the 30.5, 29.6 and 28.8 ka cal BP peaks) and regional (23.5 ka cal BP) wet events. Other peaks at 22.2, 21.8, 20.2 and 19 ka cal BP correlate with fluctuations of south-eastern Alpine glaciers. Significant peat formation continued until ≈18 ka cal BP, when the last peak occurred. A marked decrease in peat formation is recorded concomitantly with the onset of Heinrich Event 2 (i.e. the 26 ka cal BP trough). The good correspondence of sedimentary events in the Brenta glaciofluvial system with the dynamics of glaciers and glaciofluvial and lacustrine systems in the southern Eastern Alps suggests a common climatic forcing on the whole region during the LGM. Peat layer formation in the floodplain fens increased significantly in correspondence with glacier withdrawals and/or wetter climatic episodes, constituting a good proxy for climatic fluctuations during glacial periods. It also allows correlations across different continental environments and regions in the northern hemisphere. © 2016 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59487
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Geosciences, University of Padova, Via G. Gradenigo 6, Padova, Italy
Recommended Citation:
Rossato S.,Mozzi P.. Inferring LGM sedimentary and climatic changes in the southern Eastern Alps foreland through the analysis of a 14C ages database (Brenta megafan, Italy)[J]. Quaternary Science Reviews,2016-01-01,148