DOI: 10.1016/j.gloplacha.2015.04.003
论文题名: Deciphering magnetoclimatological patterns of late Early to early Middle Pleistocene loess-paleosol sequences in the western Chinese Loess Plateau
作者: Wang X. ; Yang Z. ; Chen Y. ; Hu J. ; Tang L. ; Sheng M. ; Løvlie R.
刊名: Global and Planetary Change
ISSN: 0921-8181
出版年: 2015
卷: 130 起始页码: 37
结束页码: 46
语种: 英语
英文关键词: East Asian monsoon
; Loess-paleosol sequence
; Mineral magnetism
; Paleoclimate
; Pedogenic intensity
; Western Chinese Loess Plateau
Scopus关键词: Analytical geochemistry
; Atmospheric thermodynamics
; Geochemistry
; Grain size and shape
; Landforms
; Magnetic susceptibility
; Magnetism
; Magnetization
; Minerals
; Saturation magnetization
; Sediments
; Wind
; Zirconium
; East Asian monsoon
; Loess-paleosol sequence
; Paleoclimates
; Pedogenic intensity
; Western Chinese Loess Plateau
; Magnetic bubbles
; eolian deposit
; frequency dependence
; grain size
; loess
; magnetic method
; magnetic susceptibility
; paleoclimate
; paleosol
; pedogenesis
; Pleistocene
; precipitation intensity
; proxy climate record
; remanent magnetization
; China
; Loess Plateau
英文摘要: A detailed environmental magnetic investigation in conjunction with geochemical, bulk grain size and redness analyses of late Early to early Middle Pleistocene loess-paleosol sequences at the Jiuzhoutai and Caotan loess sections has been carried out, aimed to explore the reliability of magnetic parameters as paleoclimatic proxies in the western Chinese Loess Plateau (CLP). The results show that magnetic enhancement of early- to mid-Pleistocene loess-paleosol sequences at both sites is not solely due to the neoformation of ultrafine magnetic particles through pedogenesis, but in the case of several loess layers (e.g., L8 and L9) is more attributed to the significant input of coarse-grained magnetic minerals associated with the advance of desert margin and/or with significant changes in local sediment input. Since the magnetoclimatological signals studied here are obviously controlled by both pedogenesis and wind vigor, measurements of magnetic susceptibility (χ) and saturation isothermal remanent magnetization (SIRM), both of which are responsive to both ultrafine pedogenic magnetic particles and eolian coarse-grained pseudo-single domain/multi-domain magnetic particles, could not provide unambiguous interpretation of the magnetic response to the East Asian summer monsoon intensity. In contrast, anhysteretic remanent magnetization (ARM) and the percentage of frequency-dependent magnetic susceptibility (χfd %), which are notably responsive to ultrafine magnetic particles, can aptly trace changes in the concentration of pedogenic magnetic particles and can therefore be used as reliable proxies of pedogenic intensity. The magnetic grain size dependent proxies, e.g., ARM/χ and ARM/Ms (Ms , saturation magnetization), geochemical indices (e.g., chemical index of alteration, Zr/Rb and Al/Si ratios), and bulk grain size records all exhibit concordant variations and are more straightforward proxies for addressing the East Asian monsoon variability. Therefore the combination of multi-parameter mineral magnetic, geochemical and grain size analyses is very useful for distinguishing, delimiting and correlating loess sequences, and for accurately deciphering their paleoclimatic signals embedded in the weakly weathered loess. As the classical precipitation-driven pedogenic model for magnetic susceptibility enhancement is not entirely applicable to the early- to mid-Pleistocene loess developed in the semi-arid western CLP, considerable caution should also be warranted in using magnetic susceptibility measurements alone in the quantitative reconstruction of paleoprecipitation. © 2015 Elsevier B.V. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84928808780&doi=10.1016%2fj.gloplacha.2015.04.003&partnerID=40&md5=49e73f3a5a528ca82929af6c7f09769b
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/11521
Appears in Collections: 全球变化的国际研究计划 气候变化与战略
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作者单位: MLR Key Laboratory of Paleomagnetism and Paleotectonic Reconstruction, Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing, China
Recommended Citation:
Wang X.,Yang Z.,Chen Y.,et al. Deciphering magnetoclimatological patterns of late Early to early Middle Pleistocene loess-paleosol sequences in the western Chinese Loess Plateau[J]. Global and Planetary Change,2015-01-01,130.