DOI: 10.1016/j.quascirev.2015.03.019
Scopus记录号: 2-s2.0-84927127100
论文题名: Varves in lake sediments - a review
作者: Zolitschka B. ; Francus P. ; Ojala A.E.K. ; Schimmelmann A.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2015
卷: 117 起始页码: 1
结束页码: 41
语种: 英语
英文关键词: Calendar-year dating
; Climate reconstruction
; Environmental variations
; Human impact
; Varve
; Varve chronology
; Varve composition
; Varve counting
; Varve formation
; Varve types (clastic varves, biogenic varves, endogenic varves)
Scopus关键词: Catchments
; Deposition
; Eutrophication
; Floods
; Lakes
; Risk assessment
; Volcanoes
; Calendar-year dating
; Climate reconstruction
; Environmental variations
; Human impact
; Varve
; Varve chronologies
; Varve counting
; Varve formation
; Varve types (clastic varves, biogenic varves, endogenic varves)
; Sediments
; anthropogenic effect
; bioturbation
; dating method
; depositional environment
; lacustrine deposit
; literature review
; paleoenvironment
; proglacial environment
; seasonal variation
; varve
; water column
英文摘要: Downcore counting of laminations in varved sediments offers a direct and incremental dating technique for high-resolution climatic and environmental archives with at least annual and sometimes even seasonal resolution. The pioneering definition of varves by De Geer (1912) had been restricted to rhythmically deposited proglacial clays. One century later the meaning of 'varve' has been expanded to include all annually deposited laminae in terrestrial and marine settings. Under favourable basin configurations and environmental conditions, limnic varves are formed due to seasonality of depositional processes from the lake's water column and/or transport from the catchment area. Subsequent to deposition of topmost laminae, the physical preservation of the accumulating varved sequence requires the sustained absence of sediment mixing, for example via wave action or macrobenthic bioturbation. Individual (sub)laminae in varved lake sediments typically express contrasting colours, always differ in terms of their organic, chemical and/or mineralogical compositions, and often also differ with regard to grain-size. Various predominating climatic and depositional conditions may result in clastic, biogenic or endogenic (incl. evaporitic) varved sediments and their mixtures.To reliably establish a varve chronology, the annual character of laminations needs to be determined and verified in a multidisciplinary fashion. Sources and influences of possible errors in varve chronologies are best determined and constrained by repeated varve counts, and by including radioisotopes and correlation with historically documented events. A well-established varve chronology greatly enhances the scientific value of laminated limnic archives by securely anchoring the wealth of multi-proxy palaeoenvironmental information in the form of time-series for multidisciplinary investigations.Applications of varved records are discussed with special reference to advances since the 1980s. These span fields like calibrating radiometric dating methods, reconstructing past changes of the Earth's magnetic field or detecting fluctuations in solar forcing. Once a varve chronology is established it can be applied to precisely date events like volcanic ash layers, earthquakes or human impact, as well as short- and long-term climate (temperature, precipitation, wind, hydroclimatic conditions or flooding) and environmental changes (eutrophication, pollution). Due to their exceptional high temporal resolution and in combination with their robust and accurate "internal" time scale in calendar years, annually laminated sediments can be regarded as one of the most precious environmental archives on the continents. These records are necessary to extend temporally limited instrumental records back in time. As such they have societal relevance with regard to risk assessments related to natural hazards arising from e.g. flooding or volcanic eruptions. © 2015 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59938
Appears in Collections: 过去全球变化的重建
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作者单位: Geomorphology and Polar Research (GEOPOLAR), Institute of Geography, University of Bremen, Celsiusstraße FVG-M, Bremen, Germany; Centre Eau Terre Environnement, Institut National de la Recherche Scientifique, Quebec-City, QC, Canada; GEOTOP Research Center, Montréal, QC, Canada; Geological Survey of Finland, Espoo, Finland; Indiana University, Department of Geological Sciences, 1001 East 10th Street, Bloomington, IN, United States
Recommended Citation:
Zolitschka B.,Francus P.,Ojala A.E.K.,et al. Varves in lake sediments - a review[J]. Quaternary Science Reviews,2015-01-01,117