DOI: 10.1016/j.quascirev.2018.01.016
Scopus记录号: 2-s2.0-85042515774
论文题名: Sedimentary and rock magnetic signatures and event scenarios of deglacial outburst floods from the Laurentian Channel Ice Stream
作者: Leng W. ; von Dobeneck T. ; Bergmann F. ; Just J. ; Mulitza S. ; Chiessi C.M. ; St-Onge G. ; Piper D.J.W.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2018
卷: 186 起始页码: 27
结束页码: 46
语种: 英语
英文关键词: Environmental magnetism
; Event stratigraphy
; Grand Banks Slope
; Hyperpycnal flow
; Laurentian Channel and Fan
; Paleoceanography
; Plumite deposits
; Quaternary
; Sedimentology-marine cores
; Subglacial outburst flood
Scopus关键词: Deposits
; Floods
; Geomagnetism
; Grain size and shape
; Lithology
; Magnetism
; Sedimentary rocks
; Sedimentology
; Sediments
; Stratigraphy
; Environmental magnetism
; Event stratigraphies
; Grand banks
; Hyperpycnal flows
; Laurentian
; Marine cores
; Outburst floods
; Paleoceanography
; Quaternary
; Ice
英文摘要: Eastern Canadian margin sediments bear testimony to several catastrophic deglacial meltwater discharges from the retreating Laurentide Ice Sheet. The reddish-brown plumite layers deposited on the levees of the Laurentian Fan valleys have been recognized as indications of multiple outburst floods between Heinrich events 2 and 1. Five event layers have been consistently recorded in three new gravity cores retrieved on the SW Grand Banks slope and comply with the previously published Laurentian Fan core MD95-2029. The apparently huge extent of these outburst plumes around the Laurentian Fan as well as their causes and consequences are investigated in this study using physical properties, rock magnetic and grain-size analyses, together with seismoacoustic profiling. We provide the first detailed 14C ages of the outburst event sequence and discuss their recurrence intervals in the context of regional ice retreat. Compared to the hemipelagic interlayers, event layers have overall uniform and systematic changes of rock-magnetic properties. Hematite contents increase over time and proximally while magnetite grain sizes fine upwards and spatially away from the fan. Based on the sediment composition and load, we argue that these plumites were formed by recurrent erosion of glacial mud deposits in the Laurentian Channel by meltwater outbursts. Three alternative glaciological scenarios are evaluated: in each case, the provenance of the transported sediment is not an indicator of the precise source of the meltwater. © 2018 Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/112242
Appears in Collections: 气候减缓与适应
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作者单位: MARUM-Center for Marine Environmental Sciences and Faculty of Geosciences, University of Bremen, Bremen, Germany; Institut des Sciences de la Mer de Rimouski (ISMER), Canada Research Chair in Marine Geology, Université du Québec à Rimouski and GEOTOP, Canada; Natural Resources Canada, Geological Survey of Canada, Bedford Institute of Oceanography, Dartmouth, NS, Canada; School of Arts, Sciences and Humanities, University of São Paulo, São Paulo, Brazil
Recommended Citation:
Leng W.,von Dobeneck T.,Bergmann F.,et al. Sedimentary and rock magnetic signatures and event scenarios of deglacial outburst floods from the Laurentian Channel Ice Stream[J]. Quaternary Science Reviews,2018-01-01,186