DOI: 10.1016/j.gloplacha.2013.03.013
论文题名: A new dimension to sediment magnetism: Charting the spatial variability of magnetic properties across lake basins
作者: Lascu I. ; Plank C.
刊名: Global and Planetary Change
ISSN: 0921-8233
出版年: 2013
卷: 110 起始页码: 340
结束页码: 349
语种: 英语
英文关键词: Magnetic properties
; Minnesota
; Small lakes
; Surface sediments
Scopus关键词: Bacterial magnetosomes
; Environmental conditions
; Magnetotactic Bacteria
; Minnesota
; Preservation potential
; Sediment deposition
; Sedimentary records
; Surface sediments
; Chains
; Magnetic properties
; Magnetite
; Surficial sediments
; Lakes
; allochthon
; autochthon
; bacterium
; depositional environment
; grain size
; lacustrine deposit
; magnetic property
; magnetite
; magnetization
; morphology
; particulate matter
; spatial variation
; surficial sediment
; Minnesota
; United States
; Bacteria (microorganisms)
英文摘要: We have investigated the variability of the magnetic properties of surface sediments across eight Minnesota lake basins. The measured magnetic properties are controlled by the competing fluxes of allochthonous and autochthonous magnetic particles, and differ according to location in the basin. Shoreline sediments are dominated by detrital magnetic particles, whereas littoral and profundal sediments are characterized by a combination of bacterial magnetosomes and detrital particles. The position of the oxic-anoxic interface, which may occur in the water or within the sediment column, controls the depth at which living magnetotactic bacteria occur, and determines the degree of preservation of their magnetosome chains in the surface sediment. The preservation potential of undisturbed chains is higher for bacterial magnetite formed at the top of the sediment column in the littoral area than for magnetosomes originating in the water column in the profundal area. Bacterial magnetite in the profundal facies will contain a higher proportion of chains collapsed during settlement through the water column to the lake bottom. This process increases the fraction of interacting magnetosomes, which in turn artificially lowers the ARM ratio (χARM/IRM), which ceases to be a reliable grain size indicator in the profundal environment. Our results indicate that a holistic approach to interpreting limnologically-derived paleoecological data should be employed. Specifically, a thorough understanding of evolving and interrelated factors such as basin morphology and limnologic conditions is crucial for a more confident interpretation of the sedimentary record in terms of environmental conditions at the time of sediment deposition. © 2013 Elsevier B.V. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84888842898&doi=10.1016%2fj.gloplacha.2013.03.013&partnerID=40&md5=14093db4209113759cd14d98dc64ae8a
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/11139
Appears in Collections: 全球变化的国际研究计划
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作者单位: Institute for Rock Magnetism, N. H. Winchell School of Earth Sciences, University of Minnesota, 310 Pillsbury Drive SE, Minneapolis, MN 55455, United States
Recommended Citation:
Lascu I.,Plank C.. A new dimension to sediment magnetism: Charting the spatial variability of magnetic properties across lake basins[J]. Global and Planetary Change,2013-01-01,110.