DOI: 10.1016/j.gloplacha.2013.05.010
论文题名: Dynamics of late quaternary north african humid periods documented in the clay mineral record of central aegean sea sediments
作者: Ehrmann W. ; Seidel M. ; Schmiedl G.
刊名: Global and Planetary Change
ISSN: 0921-8269
出版年: 2013
卷: 107 起始页码: 186
结束页码: 195
语种: 英语
英文关键词: African Humid Periods
; Aridity
; Kaolinite/chlorite ratio
; Late Quaternary
; Wind transport
Scopus关键词: Aeolian transport
; Aridity
; Humid periods
; Last glacial period
; Late quaternary
; Marine isotope stages
; Non-linear response
; Wind transport
; Arid regions
; Climate change
; Isotopes
; Kaolinite
; Lakes
; Vegetation
; Sediments
; clay mineral
; eolian deposit
; humid environment
; lacustrine deposit
; Last Glacial
; Quaternary
; sediment core
; Aegean Sea
; Mediterranean Sea
; North Africa
英文摘要: The ratio between the clay minerals kaolinite and chlorite has been investigated in high resolution in a late Quaternary sediment core from the central Aegean Sea. The record spans the last ca. 105. ka. The kaolinite/chlorite ratio was used to reconstruct the fine-grained aeolian dust influx from the North African deserts, mainly derived from desiccated lake depressions. It therewith can be used as a proxy for wind activity, aridity and vegetation cover in the source area. The data document three major humid phases in North Africa bracketing the formation of sapropel layers S4, S3 and S1. They occur at >. 105-95. ka, 83.5-72. ka and 14-2. ka. The first two phases are characterised by relatively abrupt lower and upper boundaries suggesting a non-linear response of vegetation to precipitation, with critical hydrological thresholds. In contrast, the onset and termination of the last humid period were more gradual. Highest kaolinite/chlorite ratios indicating strongest aeolian transport and aridity occur during Marine Isotope Stage (MIS) 5b, at ca. 95-84. ka. The long-term decrease in kaolinite/chlorite ratios during the last glacial period indicates a gradual decline of deflatable lake sediments in the source areas. © 2013 Elsevier B.V. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84879586576&doi=10.1016%2fj.gloplacha.2013.05.010&partnerID=40&md5=4b162c776b074f6af339aaead91abe46
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/11175
Appears in Collections: 全球变化的国际研究计划
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作者单位: Universität Leipzig, Institut für Geophysik und Geologie, Talstraße 35, D-04103 Leipzig, Germany
Recommended Citation:
Ehrmann W.,Seidel M.,Schmiedl G.. Dynamics of late quaternary north african humid periods documented in the clay mineral record of central aegean sea sediments[J]. Global and Planetary Change,2013-01-01,107.