气候变化领域集成服务门户(CCPortal): Astronomically forced climate change in the late Cambrian

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DOI	10.1016/j.epsl.2020.116475
	Astronomically forced climate change in the late Cambrian
	Sørensen A.L.; Nielsen A.T.; Thibault N.; Zhao Z.; Schovsbo N.H.; Dahl T.W.
发表日期	2020
ISSN	0012821X
卷号	548
英文摘要	We report evidence for Milankovitch cycles in two drill cores from the Cambro–Ordovician Alum Shale Formation of Scandinavia. The signal is preserved in elemental abundances recorded at high stratigraphic resolution by core scanning XRF analysis (0.2 mm resolution). The new data enable us to establish a floating timeline calibrated to the stable 405 kyr eccentricity cycle for a ∼8.7 Myr interval across the Miaolingian–Furongian boundary. This interval spans the Steptoean Positive Carbon Isotope Excursion (SPICE), which is recorded in the δ13Corg in the studied drill cores. We calculate the durations of the Olenus Superzone to 3.4 ± 0.2 Myr, the Parabolina Superzone to 1.9 ± 0.3 Myr, the Leptoplastus Superzone to 0.33 ± 0.18 Myr, the Protopeltura Superzone to 0.51 ± 0.20 Myr, and the SPICE event straddling the Paibian and lower main part of the Jiangshanian Stage to 3.0 ± 0.2 Myr. The sedimentation rate shows similar trends at both drilling locations and is inversely correlated to eustatic sea level changes in certain time intervals, opening tantalizing new prospects of using cyclostratigraphic analyses of shales to track eustatic sea level variations. The identification of obliquity cycles enables us to calculate the Cambrian Earth–Moon distance as well as the day length at ∼493 Ma to 368.9 ± 2.3 ⋅ 106 m and 21.78 ± 0.29 hr, respectively. © 2020 Elsevier B.V.
关键词	Alum Shale core scanning XRF cyclostratigraphy Earth–Moon distance Furongian SPICE event
英文关键词	Circuit simulation; Climate change; Drills; Infill drilling; Moon; Sea level; Shale; Stratigraphy; Carbon isotope excursions; Eccentricity cycle; Elemental abundance; Eustatic sea level; Milankovitch cycle; Scanning XRF analysis; Sedimentation rates; Shale formation; Core drilling; Cambrian; climate change; Milankovitch cycle; Moon; sea level change; shale; X-ray fluorescence
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202899
作者单位	GLOBE Institute, University of Copenhagen, Denmark; Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark; Geological Survey of Denmark and Greenland (GEUS), Denmark
推荐引用方式 GB/T 7714	Sørensen A.L.,Nielsen A.T.,Thibault N.,et al. Astronomically forced climate change in the late Cambrian[J],2020,548.
APA	Sørensen A.L.,Nielsen A.T.,Thibault N.,Zhao Z.,Schovsbo N.H.,&Dahl T.W..(2020).Astronomically forced climate change in the late Cambrian.Earth and Planetary Science Letters,548.
MLA	Sørensen A.L.,et al."Astronomically forced climate change in the late Cambrian".Earth and Planetary Science Letters 548(2020).