MATUYAMA/BRUNHES (M/B) TRANSITION RECORDED IN CHINESE LOESS

doi:10.5636/jgg.45.319

IEECAS OpenIR > 黄土与第四纪地质国家重点实验室（1985-2004）

	MATUYAMA/BRUNHES (M/B) TRANSITION RECORDED IN CHINESE LOESS
	SUN, DH; SHAW, J; AN, ZS; ROLPH, T
	1993
发表期刊	JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY
卷号	45 期号:4 页码:319-330
文章类型	Article
摘要	Here we present a detailed record of the Matuyama/Brunhes (M/B) polarity transition recorded in a loess section at Xifeng (36-degrees-N, 108-degrees-E), in the central part of the Chinese loess plateau. The transition zone, which occurs in loess unit L8, has a thickness of 3.8 m and was sampled in full. At this point in the section the loess accumulation rate has been estimated at 10 cm/ka, and with the size of sub-sample used provides a potential time resolution of 240 years. Magnetite has been identified as the main magnetic mineral with a small contribution from maghaemite or cation deficient magnetite. The remanence of all samples was investigated using thermal demagnetisation from room temperature up to 650-degrees-C. The results indicate a duration of 32,000 years for the decay and recovery of the main dipole intensity, and 20,000 years for the period of major directional change. During the transition the field intensity falls to an average of 30% of its value before and after the transition, although there are strong variations about this weak value which accompany a sequence of 4 reversed/normal/reversed fluctuations of the local field vector. These fluctuations immediately preceed the final reversed-normal transition, after which the field intensity recovers to its pre-transition value. Calculated VGP paths of most stages are continuous and confined to preferred longitude bands which include America, the Atlantic Ocean or Africa. Field behaviour during the transition period suggests that non-dipolar terms are dominant while the dipole field is weak, with the dipole decay and recovery associated with the increased influence of low order zonal terms of the geomagnetic field.
学科领域	Geology
DOI	10.5636/jgg.45.319
关键词[WOS]	GEOMAGNETIC REVERSAL ; POLARITY TRANSITION ; SEDIMENTS ; EQUATORIAL
收录类别	SCI ; SCIE
语种	英语
WOS研究方向	Geosciences, Multidisciplinary
WOS记录号	WOS:A1993LC76500005
出版者	TERRA SCIENTIFIC PUBL CO
引用统计	被引频次：29[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.ieecas.cn/handle/361006/11975
专题	黄土与第四纪地质国家重点实验室（1985-2004）
推荐引用方式 GB/T 7714	SUN, DH,SHAW, J,AN, ZS,et al. MATUYAMA/BRUNHES (M/B) TRANSITION RECORDED IN CHINESE LOESS[J]. JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY,1993,45(4):319-330.
APA	SUN, DH,SHAW, J,AN, ZS,&ROLPH, T.(1993).MATUYAMA/BRUNHES (M/B) TRANSITION RECORDED IN CHINESE LOESS.JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY,45(4),319-330.
MLA	SUN, DH,et al."MATUYAMA/BRUNHES (M/B) TRANSITION RECORDED IN CHINESE LOESS".JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY 45.4(1993):319-330.