气候变化领域集成服务门户(CCPortal): Early and middle Matuyama geomagnetic excursions recorded in the Chinese loess-paleosol sediments

CCPortal

DOI	10.1186/BF03352745
	Early and middle Matuyama geomagnetic excursions recorded in the Chinese loess-paleosol sediments
	Yang, Tianshui; Hyodo, Masayuki; Yang, Zhenyu; Ding, Lin; Fu, Jianli; Mishima, Toshiaki
发表日期	2007
ISSN	1343-8832
起始页码	825
结束页码	840
卷号	59 期号:7
英文摘要	A detailed paleomagnetic and rock-magnetic investigation on the early and middle Matuyama loess-paleosol sediments has been carried out at the Baoji section, Shaanxi province, southern Chinese Loess Plateau. Our new magnetostatigraphy revises the position of the lower Olduvai boundary from L27 to S26. Seven short-lived geomagnetic excursions, tentatively named as E1, E2, E3, E4, E5, E6, and E7, have been recognized in the L13. S22. L26, L27, S29, and upper and middle parts of L32, respectively. Results of the anisotropy of low-field magnetic susceptibility (AMS) show that the studied loess-paleosol sediments retain the primary sedimentary fabric. Rock magnetic experiments reveal that the sediments from the excursional and polarity transitional intervals have the same magnetic characteristics as those from the surrounding normal and reversed polarity intervals. Assuming a constant accumulation rate between polarity boundaries, these seven excursions are estimated to be at about 11.1 Ma (E1), 1.58 Ma (E2), 1.92 Ma (E3), 2.11 Ma (E4), 2.25 Ma (E5), 2.35 Ma (E6), and 2.42 Ma (E7) Ma. The El and E2 in the middle Matuyama Chron can be correlated with the Punart-lu and Stage 54 (Gilsa) excursions, respectively. The E4, E5, and E7 in the early Matuyama Chron can be Correlated with the Reunion II, Wunion I, and cryptochron C2r.2r-1 (X-subchron), respectively. The E3 in the lower Olduvai subchron and E6 in the early Matuyama Chron have no comparable events. At present they can only be correlated with the anomalous directions observed in the Osaka Bay core (Biswas et al., 1999). Therefore, further investigations are necessary to support their global occurrences. The present result together with the two late Matuyama excursions dated at about 0.89 Ma and 0.92 Ma (Yang et al., 2004) show that the Baoji section yields at least nine Matuyama excursions which, along with the results of the study, suggests that eight excursions occur at 0.9-2.2 Ma (Channell et al., 2002), thereby providing evidence that the short-lived geomagnetic excursions may also be a basic characteristic of the geornagnetic field during the Matuyama Chron.
关键词	POLARITY TIME-SCALE NORTH-CENTRAL CHINA TRANSITIONALLY MAGNETIZED LAVAS EAST-ASIAN MONSOON PALEOENVIRONMENTAL ARCHIVES PLIOPLEISTOCENE SEDIMENTS ASTRONOMICAL TIMESCALE TEPHRA LAYER BLAKE EVENT PLATEAU
英文关键词	geomagnetic excursion; paleomagnetism; magnetostratigraphy; loess; Matuyama Chron; Olduvai; Punaruu; Stage 54; Reunion; cryptochron C2r-.2r-1
语种	英语
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS记录号	WOS:000248613700020
来源期刊	EARTH PLANETS AND SPACE
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/257520
推荐引用方式 GB/T 7714	Yang, Tianshui,Hyodo, Masayuki,Yang, Zhenyu,et al. Early and middle Matuyama geomagnetic excursions recorded in the Chinese loess-paleosol sediments[J]. 中国科学院青藏高原研究所,2007,59(7).
APA	Yang, Tianshui,Hyodo, Masayuki,Yang, Zhenyu,Ding, Lin,Fu, Jianli,&Mishima, Toshiaki.(2007).Early and middle Matuyama geomagnetic excursions recorded in the Chinese loess-paleosol sediments.EARTH PLANETS AND SPACE,59(7).
MLA	Yang, Tianshui,et al."Early and middle Matuyama geomagnetic excursions recorded in the Chinese loess-paleosol sediments".EARTH PLANETS AND SPACE 59.7(2007).