Rock-magnetic proxies of climate change in the loess-palaeosol sequences of the western Loess Plateau of China
Christopher P. Hunt,Subir K. Banerjee,Jiamao Han,Peter Solheid,Eric A. Oches,Weiwei Sun,Tungsheng Liu +6 more
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TLDR
In this article, a detailed study of the climate proxy record in the loess-palaeosol sequence at Xining-one of the few palaeoclimate sites in the currently arid western Loess Plateau of China-illustrates the importance of making many types of rockmagnetic measurements other than susceptibility.Abstract:
SUMMARY Results of the first detailed study of the climate proxy record in the loess-palaeosol sequence at Xining-one of the few palaeoclimate sites in the currently arid western Loess Plateau of China-illustrate the importance of making many types of rockmagnetic measurements other than susceptibility. A multiparameter approach yielded confirmation that here, as elsewhere in the Loess Plateau, the susceptibility enhancement in palaeosols was caused primarily by ultrafine magnetite and maghaemite. Nevertheless, magnetic enhancement was caused not exclusively by changes in relative grain size, but also by variations in concentration and mineralogy of the magnetic fraction. The effects of concentration variations were removed through normalization of susceptibility and anhysteretic remanence with saturation magnetization and saturation remanence, respectively. The resulting signal was ascribed more confidently to variation in magnetic grain size, which in turn was interpreted as a better proxy of pedogenesis than simple susceptibility. Variations in magnetic mineralogy were also determined to constrain interpretations further. The data were then used to discuss climate history at Xining. Finally, results from Xining were compared with other western sites and contrasted with eastern sites. In summary: (1) data is presented from a new Loess Plateau site which also appears to yield a global climate signal; (2) a demonstration is made of a more rock-magnetically robust way to separate concentration, composition and grain-size controls on susceptibility and other magnetic parameters; and (3) models are provided for inter-regional comparisons of palaeoclimate proxy records.read more
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Environmental magnetism: Principles and applications
Qingsong Liu,Andrew P. Roberts,Juan C. Larrasoaña,Subir K. Banerjee,Yohan Guyodo,Lisa Tauxe,Frank Oldfield +6 more
TL;DR: In this article, a review of magnetic properties and the environmental processes that give rise to the measured magnetic signal is presented, and the power of environmental magnetism in enabling quantitative environmental interpretations is discussed.
Journal ArticleDOI
Magnetic susceptibility of soil: an evaluation of conflicting theories using a national data set
John A. Dearing,K. L. Hay,Serwan M. J. Baban,A. S. Huddleston,E. M. H. Wellington,P. J. Loveland +5 more
TL;DR: In this paper, a mechanism for the formation of secondary ferrimagnetic minerals that links abiological weathering and biological fermentation processes was proposed, which may be linked to climate, and observed causative associations between climate and the magnetic susceptibility of loess-palaeosol sequences are supported by the findings.
Journal ArticleDOI
Geochemistry of the Xining, Xifeng and Jixian sections, Loess Plateau of China: eolian dust provenance and paleosol evolution during the last 140 ka
TL;DR: In this article, Li et al. analyzed three distant sections (Xining, Xifeng, Jixian) of the Chinese Loess Plateau for chemical and Nd-Sr isotopic compositions in order to obtain information about the paleoclimatic variation during the last 140 ka.
Journal ArticleDOI
Review of recent developments in mineral magnetism of the Chinese loess
TL;DR: In this paper, a review focusing on recent developments in loess magnetism is presented, and the merits and limitations of rock magnetic proxies are carefully evaluated and several currently unsolved problems are addressed.
Journal ArticleDOI
On the superparamagnetic—stable single domain transition for magnetite, and frequency dependence of susceptibility
TL;DR: In this paper, the authors reviewed the nature of the superparamagnetic stable single domain transition and showed that the change of AC susceptibilities with grain size (or temperature) at the SP-SSD boundary is more gradual than commonly assumed.
References
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Journal ArticleDOI
Magnetic susceptibility evidence of monsoon variation on the Loess Plateau of central China during the last 130,000 years
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