DOI: 10.1016/j.quascirev.2015.10.040
Scopus记录号: 2-s2.0-84949316791
论文题名: Shifting sediment sources in the world's longest river: A strontium isotope record for the Holocene Nile
作者: Woodward J. ; Macklin M. ; Fielding L. ; Millar I. ; Spencer N. ; Welsby D. ; Williams M.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2015
卷: 130 起始页码: 124
结束页码: 140
语种: 英语
英文关键词: African humid period
; Climate change
; Egypt
; Flood hydrology
; Holocene
; Nile
; Sahara
; Sediment sources
; Sr isotopes
; Sudan
Scopus关键词: Arid regions
; Banks (bodies of water)
; Catchments
; Climate change
; Deposits
; Floods
; Floors
; Hydrology
; Isotopes
; Landforms
; Rivers
; Strontium
; Strontium deposits
; Egypt
; Flood hydrology
; Holocenes
; Humid periods
; Nile
; Sahara
; Sediment sources
; Sr isotopes
; Sudan
; Sediments
; climate variation
; desert
; eolian deposit
; floodplain
; global change
; Holocene
; hydrology
; isotopic analysis
; isotopic composition
; neodymium isotope
; reconstruction
; sedimentation rate
; strontium isotope
; Egypt
; Nile Valley
; Sahara
; Sudan
英文摘要: We have reconstructed long-term shifts in catchment sediment sources by analysing, for the first time, the strontium (Sr) and neodymium (Nd) isotope composition of dated floodplain deposits in the Desert Nile. The sediment load of the Nile has been dominated by material from the Ethiopian Highlands for much of the Holocene, but tributary wadis and aeolian sediments in Sudan and Egypt have also made major contributions to valley floor sedimentation. The importance of these sources has shifted dramatically in response to global climate changes. During the African Humid Period, before c. 4.5 ka, when stronger boreal summer insolation produced much higher rainfall across North Africa, the Nile floodplain in northern Sudan shows a tributary wadi input of 40-50%. Thousands of tributary wadis were active at this time along the full length of the Saharan Nile in Egypt and Sudan. As the climate became drier after 4.5 ka, the valley floor shows an abrupt fall in wadi inputs and a stronger Blue Nile/Atbara contribution. In the arid New Kingdom and later periods, in palaeochannel fills on the margins of the valley floor, aeolian sediments replace wadi inputs as the most important secondary contributor to floodplain sedimentation. Our sediment source data do not show a measurable contribution from the White Nile to the floodplain deposits of northern Sudan over the last 8500 years. This can be explained by the distinctive hydrology and sediment delivery dynamics of the upper Nile basin. High strontium isotope ratios observed in delta and offshore records - that were previously ascribed to a stronger White Nile input during the African Humid Period - may have to be at least partly reassessed. Our floodplain Sr records also have major implications for bioarchaeologists who carry out Sr isotope-based investigations of ancient human remains in the Nile Valley because the isotopic signature of Nile floodplain deposits has shifted significantly over time. © 2015. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59759
Appears in Collections: 过去全球变化的重建
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作者单位: Geography, School of Environment, Education and Development, The University of Manchester, Manchester, United Kingdom; Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, United Kingdom; Innovative River Solutions, Institute of Agriculture and Environment, Massey University, Private Bag 11 222, Palmerston North, New Zealand; Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom; NERC Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Nottingham, United Kingdom; Department of Ancient Egypt and Sudan, The British Museum, London, United Kingdom; Earth Sciences, University of Adelaide, Adelaide, SA, Australia
Recommended Citation:
Woodward J.,Macklin M.,Fielding L.,et al. Shifting sediment sources in the world's longest river: A strontium isotope record for the Holocene Nile[J]. Quaternary Science Reviews,2015-01-01,130