气候变化领域集成服务门户(CCPortal): A robust geochronology of the Yangtze River Delta based on magnetostratigraphy and cyclostratigraphy of sediment core ZKA2

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DOI	10.1016/j.palaeo.2019.109532
	A robust geochronology of the Yangtze River Delta based on magnetostratigraphy and cyclostratigraphy of sediment core ZKA2
	Xu Y.; Jiang R.; Deng Y.; Kemp D.B.; Yang Z.; Huang C.; Zhu Z.
发表日期	2020
ISSN	0031-0182
卷号	541
英文摘要	Studying the evolution of sea-level fluctuations, climate oscillations and tectonic movements in the Yangtze River Delta requires a reliable chronology. Here, we present the results of a comprehensive study of the magnetostratigraphy and cyclostratigraphy of a 295-m-long sediment core (ZKA2) recovered from Nantong City, Jiangsu Province, China. Anisotropy of magnetic susceptibility (AMS) studies reveal that the petrofabrics are mainly primary. Based on rock magnetic and thermal demagnetization analyses, the major magnetic minerals in the studied sediments are magnetite, hematite and greigite, but only magnetite and hematite carry the primary remanence. The magnetostratigraphy reveals seven reversed polarity intervals, nine normal polarity intervals, and one interval of mixed polarity. Variations in natural gamma-ray activity reflect variable continental weathering in the sediment source regions and are paced by Earth orbital cycles. Notably, a prominent 405-kyr long eccentricity cycle and ~100-kyr short eccentricity cycle are evident, which allow us to constrain the basal age of core ZKA2 to ~3.1 Ma. The magnetostratigraphic and cyclostratigraphic results together enable us to define the depths of key chronostratigraphic and magnetostratigraphic boundaries. They include the Late/Middle Pleistocene boundary at ~18-m depth, the Brunhes/Matuyama boundary at ~88-m depth, and the Matuyama/Gauss boundary at ~254-m depth. According the new chronology, we find that although clear long eccentricity (~405 kyr) and short eccentricity cycles (~100-kyr) cycles are evident in the magnetic susceptibility record, they are not well matched with cycles of natural gamma-ray activity. This suggests the source and post depositional process of the magnetic particles is complicated, and it should be cautious to choose magnetic properties for cyclostratigraphic analysis. © 2019 Elsevier B.V.
英文关键词	Astrochronology; Magnetic susceptibility; Paleomagnetism; Quaternary
语种	英语
scopus关键词	cyclostratigraphy; demagnetization; eccentricity; geochronology; magnetic anisotropy; magnetostratigraphy; sediment core; weathering; China; Jiangsu; Nantong; Yangtze River
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/150611
作者单位	Hubei Key Laboratory of Critical Zone Evolution, School of Earth Sciences, China University of Geosciences, Wuhan, 430074, China; College of Geography and Tourism, Huanggang Normal University, Huanggang, 438000, China; Nanjing Geological Survey Center, China Geological Survey, Nanjing, 210016, China; Geology Museum of ShanxiShanxi 030024, China; State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, Wuhan, 430074, China; College of Resources, Environment and Tourism, Capital Normal University, 105 Xi San Huan Bei Road, Haidian District, Beijing, 100048, China
推荐引用方式 GB/T 7714	Xu Y.,Jiang R.,Deng Y.,et al. A robust geochronology of the Yangtze River Delta based on magnetostratigraphy and cyclostratigraphy of sediment core ZKA2[J],2020,541.
APA	Xu Y..,Jiang R..,Deng Y..,Kemp D.B..,Yang Z..,...&Zhu Z..(2020).A robust geochronology of the Yangtze River Delta based on magnetostratigraphy and cyclostratigraphy of sediment core ZKA2.Palaeogeography, Palaeoclimatology, Palaeoecology,541.
MLA	Xu Y.,et al."A robust geochronology of the Yangtze River Delta based on magnetostratigraphy and cyclostratigraphy of sediment core ZKA2".Palaeogeography, Palaeoclimatology, Palaeoecology 541(2020).