气候变化领域集成服务门户(CCPortal): New insights into the palaeoclimatic interpretation of the temperature dependence of the magnetic susceptibility and magnetization of Mid-Late Pleistocene loess/palaeosols in Central Asia and the Chinese Loess Plateau

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DOI	10.1093/gji/ggw419
	New insights into the palaeoclimatic interpretation of the temperature dependence of the magnetic susceptibility and magnetization of Mid-Late Pleistocene loess/palaeosols in Central Asia and the Chinese Loess Plateau
	Zan, Jinbo; Fang, Xiaomin; Yan, Maodu; Li, Bingshuai
通讯作者	Zan, JB (通讯作者)
发表日期	2017
ISSN	0956-540X
EISSN	1365-246X
起始页码	663
结束页码	673
卷号	208 期号:2
英文摘要	The temperature dependence of magnetic susceptibility (chi-T curves) and magnetization (M-T curves) has been used as a routine rock magnetic tool to characterize the magnetic mineralogy and magnetic granulometry of Chinese loess/palaeosols. However, palaeoclimatic interpretation of these thermomagnetic analyses remains controversial. In the present study, total organic carbon (TOC), thermomagnetic and low-temperature magnetic experiments on Mid-Late Pleistocene loess/palaeosols in Central Asia and the Chinese Loess Plateau (CLP) have been conducted. We found that the M (T) cooling curves at room temperature were mostly lower than the corresponding heating curves, whereas for the chi(T) analyses the cooling curves at room temperature were always much higher than the heating curves. Low-temperature magnetic measurements demonstrated that a large amount of superparamagnetic ferrimagnetic particles were produced during the thermal treatment and resulted in the aforementioned differences. This finding further indicated that the use of the M-T curves to estimate the relative content of maghemite in the loess/palaeosols from the CLP was problematic. In addition, a positive correlation exists between the TOC and the frequency-dependent susceptibility (chi(FD)) in the CLP, suggesting that stronger pedogenesis would result in the simultaneous increase in the content of both maghemite and organic matter. Consequently, the parameters Delta chi(1) (representing the relative content of pedogenic maghemite), Delta chi(2) (inverted left perpendicular chi(ph) - chi- inverted right perpendicular] + Delta chi(1)) and chi(ph) (related to the organic matter concentration), which can be calculated from the chi-T analyses, can potentially be used as new indicators of pedogenesis and palaeoclimate in Central Asia and the CLP.
关键词	SIZE DISTRIBUTION DEPOSITS PEDOGENESIS MAGHEMITE SEQUENCE ORIGIN
英文关键词	Environmental magnetism; Magnetic and electrical properties; Magnetic mineralogy and petrology
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000396817600005
来源期刊	GEOPHYSICAL JOURNAL INTERNATIONAL
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/258881
推荐引用方式 GB/T 7714	Zan, Jinbo,Fang, Xiaomin,Yan, Maodu,et al. New insights into the palaeoclimatic interpretation of the temperature dependence of the magnetic susceptibility and magnetization of Mid-Late Pleistocene loess/palaeosols in Central Asia and the Chinese Loess Plateau[J]. 中国科学院青藏高原研究所,2017,208(2).
APA	Zan, Jinbo,Fang, Xiaomin,Yan, Maodu,&Li, Bingshuai.(2017).New insights into the palaeoclimatic interpretation of the temperature dependence of the magnetic susceptibility and magnetization of Mid-Late Pleistocene loess/palaeosols in Central Asia and the Chinese Loess Plateau.GEOPHYSICAL JOURNAL INTERNATIONAL,208(2).
MLA	Zan, Jinbo,et al."New insights into the palaeoclimatic interpretation of the temperature dependence of the magnetic susceptibility and magnetization of Mid-Late Pleistocene loess/palaeosols in Central Asia and the Chinese Loess Plateau".GEOPHYSICAL JOURNAL INTERNATIONAL 208.2(2017).