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DOI	10.6038/cjg2019M0443
	Rock magnetic characteristics and magnetic susceptibility change mechanism of the loess since 8. 5 ka in the southern margin of Tarim Basin
	Lu Shuang; Han WenXia; Zhang Tao; Han FengQing; Lu ShengCheng; Ma XueHai; Zhang ZhiGao
通讯作者	Han, WX (通讯作者)
发表日期	2019
ISSN	0001-5733
起始页码	3053
结束页码	3066
卷号	62 期号:8
英文摘要	Magnetic susceptibility, as a convenient and reproducible rock magnetic index, has been widely used in paleoclimatic reconstruction and has achieved great success in China Loess Plateau. The mechanism that pedogenesis intensity contributes to the magnetic susceptibility is generally accepted in China Loess Plateau. However, the magnetic susceptibility change mechanism in Xinjiang is still unclear, so that the paleoclimatic significance of magnetic susceptibility remains controversial. In this study, a typical loess section (Yangchang section) with accurate chronology from the southern margin of Tarim Basin was selected for rock magnetism and high resolution magnetic susceptibility study. Combined with the grain size characteristics, mineral components and elemental concentrations, the magnetic susceptibility change mechanism was discussed. The results show that the main magnetic-bearing mineral is coarse-grained magnetite with a small amount of hard magnetic minerals and paramagnetic minerals in the Yangchang loess sediments. According to the variation characteristics of magnetic-bearing minerals and magnetic susceptibility, the section can be further divided into two stages: Phase I (8.5 similar to 2.5 ka), the content of soft magnetic minerals are relatively high, and the magnetic susceptibility stays in relatively high value. Phase II (2.5 similar to 0.2 ka), hard magnetic minerals and paramagnetic minerals, represented by pyrite, increase, while the magnetic susceptibility decreases significantly. Correlation analysis and cross wavelet analysis results show that the change of magnetic susceptibility is consistent with that of coarse particles in phase I, suggesting a so-called wind velocity theory model control of magnetic susceptibility in this stage. While in phase II, besides the positive correlation between magnetic susceptibility and the contents of coarse grain, a strong negative correlation between the magnetic susceptibility and pedogenic proxy was also observed, indicating a combined effects of wind velocity theory and reductive pedogenesis processes on magnetic susceptibility change during phase II. This study provides valuable information on rock magnetic characteristics and magnetic susceptibility change in this area, and gives a new clue on further paleoclimatic reconstruction in Xinjiang and Central Asia based on magnetic susceptibility.
关键词	CHINESE LOESS TIANSHAN MOUNTAINS PALEOSOL SEQUENCES TAKLIMAKAN DESERT ALASKAN LOESS CENTRAL-ASIA GRAIN-SIZE CLIMATE SECTION DEPOSITION
英文关键词	The southern margin of Tarim Basin; Loess; Rock magnetism; Magnetic susceptibility change mechanism; Cross wavelet analysis
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000480300600022
来源期刊	CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
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/259596
推荐引用方式 GB/T 7714	Lu Shuang,Han WenXia,Zhang Tao,et al. Rock magnetic characteristics and magnetic susceptibility change mechanism of the loess since 8. 5 ka in the southern margin of Tarim Basin[J]. 中国科学院青藏高原研究所,2019,62(8).
APA	Lu Shuang.,Han WenXia.,Zhang Tao.,Han FengQing.,Lu ShengCheng.,...&Zhang ZhiGao.(2019).Rock magnetic characteristics and magnetic susceptibility change mechanism of the loess since 8. 5 ka in the southern margin of Tarim Basin.CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,62(8).
MLA	Lu Shuang,et al."Rock magnetic characteristics and magnetic susceptibility change mechanism of the loess since 8. 5 ka in the southern margin of Tarim Basin".CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION 62.8(2019).