气候变化领域集成服务门户(CCPortal): HIRM variations in the Chinese red-clay sequence: Insights into pedogenesis in the dust source area

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DOI	10.1016/j.jseaes.2009.11.002
	HIRM variations in the Chinese red-clay sequence: Insights into pedogenesis in the dust source area
	Nie, Junsheng; Song, Yougui; King, John W.; Fang, Xiaomin; Heil, Clifford
通讯作者	Song, YG (通讯作者)
发表日期	2010
ISSN	1367-9120
EISSN	1878-5786
起始页码	96
结束页码	104
卷号	38 期号:3-4
英文摘要	Although extensive rock magnetic studies have been performed on the Chinese loess-paleosol sediments, few comparable studies have been applied to the underlying red-clay sediments. Because of this paucity of data, our understanding of the mineral magnetic properties of the red-clay sequence, and the paleoenvironmental information encoded in them, is limited. Here we report hard isothermal remanent magnetization (HIRM) variations from similar to 8.1 to similar to 1.2 Ma in the lower part of the loess-paleosol and the underlying red-clay sequences of the Chaona section on the Chinese Loess Plateau. The results indicate that there is a negative correlation between HIRM and frequency dependence of magnetic susceptibility chi(fd) (chi(fd) = chi(lf)-chi(hf), where chi(lf) and chi(hf) are magnetic susceptibility measured at 470 Hz and 4700 Hz, respectively) from similar to 3.4 to similar to 2.6 Ma and a positive correlation between these two proxies from similar to 8.1 to similar to 3.4 Ma and similar to 2.6 to similar to 1.2 Ma. We argue that the HIRM variations from similar to 8.1 to similar to 3.4 Ma and from similar to 2.6 to similar to 1.2 Ma reflect hematite availability in the dust source region, determined by the size of the area and climatic conditions of the dust source region. The negative correlation between HIRM and chi(fd) between similar to 3.4 and similar to 2.6 Ma suggests that magnetic enhancement during this time interval may be related to the alteration of hematite/goethite to magnetite/maghemite. We also find that HIRM data between 8.1 and 3.4 Ma show high coherence with the 100-kyr eccentricity signals, suggesting eccentricity forcing of concentration variations of hematite in the dust source area. Higher resolution samples are needed to determine if concentration variations of hematite in the dust source area are coherent with the orbital obliquity and precession forcing signals. (C) 2009 Elsevier Ltd. All rights reserved.
关键词	RESOLUTION MAGNETO STRATIGRAPHY PALEOCLIMATIC TIME-SERIES LOESS-PALEOSOL SEQUENCES NE TIBETAN PLATEAU NORTHERN-HEMISPHERE MOSSBAUER-SPECTROSCOPY QINGHAI PROVINCE UPLIFT MA DEPOSITS
英文关键词	Pliocene; Monsoon; Red-clay; Loess; Rock magnetism; Hematite
语种	英语
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS记录号	WOS:000276577300003
来源期刊	JOURNAL OF ASIAN EARTH SCIENCES
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/257801
推荐引用方式 GB/T 7714	Nie, Junsheng,Song, Yougui,King, John W.,et al. HIRM variations in the Chinese red-clay sequence: Insights into pedogenesis in the dust source area[J]. 中国科学院青藏高原研究所,2010,38(3-4).
APA	Nie, Junsheng,Song, Yougui,King, John W.,Fang, Xiaomin,&Heil, Clifford.(2010).HIRM variations in the Chinese red-clay sequence: Insights into pedogenesis in the dust source area.JOURNAL OF ASIAN EARTH SCIENCES,38(3-4).
MLA	Nie, Junsheng,et al."HIRM variations in the Chinese red-clay sequence: Insights into pedogenesis in the dust source area".JOURNAL OF ASIAN EARTH SCIENCES 38.3-4(2010).