气候变化领域集成服务门户(CCPortal): Orbitally driven redox fluctuations during Cretaceous Oceanic Anoxic Event 2 (OAE2) revealed by a new magnetic proxy

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DOI	10.1016/j.palaeo.2019.109465
	Orbitally driven redox fluctuations during Cretaceous Oceanic Anoxic Event 2 (OAE2) revealed by a new magnetic proxy
	Li Y.-X.; Gill B.; Montañez I.P.; Ma L.; LeRoy M.; Kodama K.P.
发表日期	2020
ISSN	0031-0182
卷号	538
英文摘要	Recent studies of the Cretaceous sedimentary records have documented that rapid redox changes between euxinic (sulfidic) and ferruginous conditions occurred during the perturbations to the global carbon cycle associated with oceanic anoxic events. This observation has major implications for the dynamics of and feedbacks on marine primary productivity and organic carbon burial during these events. The high-resolution rock magnetic study of a significantly expanded OAE2 interval in southern Tibet, presented here, provides further insight into the redox dynamics during the Cenomanian-Turonian Oceanic Anoxic Event 2 (OAE2) (~94 Ma). The ratio of hard isothermal remanent magnetization to magnetic susceptibility, HIRM/χ, is used as a proxy for bottom-water redox conditions and shows repeated fluctuations between relatively oxic and dysoxic/anoxic conditions in the eastern Tethys of the Southern Hemisphere during OAE2. Spectral analysis of a log (HIRM/χ) time series reveals cyclical variations at orbital frequencies and the subtle cyclic redox changes are found to occur within the obliquity frequency band. Moreover, variability in redox conditions at the onset of OAE2 correlates well with that recently documented for the OAE2 interval at Tarfaya, Morocco, implying that the cyclic redox variations spanned both hemispheres. Notably, the presence of obliquity signals, which dominantly influence high-latitude climate processes, in the tropics and subtropics of both the Northern and Southern Hemispheres further confirms previously hypothesized more vigorous meridional overturning circulation (MOC) during OAE2 and implies the interhemispheric/global nature of this major shift in oceanic circulation. © 2019 Elsevier B.V.
英文关键词	Cyclostratigraphy; Environmental magnetism; Fe speciation; Ocean circulation; Redox variations; Southern Tibet
语种	英语
scopus关键词	anoxic conditions; Cenomanian-Turonian boundary; Cretaceous; cyclostratigraphy; iron; isotherm; magnetic susceptibility; magnetization; organic carbon; overturn; primary production; proxy climate record; redox conditions; Southern Hemisphere; speciation (chemistry); China; Laayoune-Sakia al Hamra; Morocco; Tarfaya; Xizang
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/150674
作者单位	State Key Laboratory for Mineral Deposits Research, Key Laboratory of Surficial Geochemistry, Ministry of Education, School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210046, China; Department of Geosciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, United States; Department of Earth and Planetary Sciences, University of California, Davis, CA 95616, United States; Department of Earth and Environmental Sciences, Lehigh University, Bethlehem, PA 18015, United States
推荐引用方式 GB/T 7714	Li Y.-X.,Gill B.,Montañez I.P.,et al. Orbitally driven redox fluctuations during Cretaceous Oceanic Anoxic Event 2 (OAE2) revealed by a new magnetic proxy[J],2020,538.
APA	Li Y.-X.,Gill B.,Montañez I.P.,Ma L.,LeRoy M.,&Kodama K.P..(2020).Orbitally driven redox fluctuations during Cretaceous Oceanic Anoxic Event 2 (OAE2) revealed by a new magnetic proxy.Palaeogeography, Palaeoclimatology, Palaeoecology,538.
MLA	Li Y.-X.,et al."Orbitally driven redox fluctuations during Cretaceous Oceanic Anoxic Event 2 (OAE2) revealed by a new magnetic proxy".Palaeogeography, Palaeoclimatology, Palaeoecology 538(2020).