Orbitally driven redox fluctuations during Cretaceous Oceanic Anoxic Event 2 (OAE2) revealed by a new magnetic proxy
Orbitally driven redox fluctuations during Cretaceous Oceanic Anoxic Event 2 (OAE2) revealed by a new magnetic proxy
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新的磁性代理揭示了白垩纪海洋缺氧事件 2 (OAE2) 期间轨道驱动的氧化还原波动
DOI：
10.1016/j.palaeo.2019.109465
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发表时间：
2020-01
期刊：
影响因子：
--
通讯作者：
Kodama Kenneth P.
中科院分区：
文献类型：
--
作者：
Li Yong-Xiang;Gill Benjamin;Montanez Isabel P.;Ma Lifeng;LeRoy Matthew;Kodama Kenneth P.
最近对白垩纪沉积记录的研究表明，在与海洋缺氧事件相关的全球碳循环扰动期间，含氧（硫化物）和含铁条件之间的快速氧化还原变化发生了。这一观测结果对这些事件期间海洋初级生产力和有机碳埋藏的动态和反馈具有重要意义。硬等温剩余磁化率与磁化率之比HIRM/χ代表了OAE2期间南半球特提斯东部的底水氧化还原条件，显示了相对氧和缺氧/缺氧条件之间的反复波动。对数（HIRM/χ）时间序列的频谱分析揭示了轨道频率的周期性变化，并且发现在倾角频带内发生了微妙的循环氧化还原变化。此外，OAE2开始时氧化还原条件的变化与最近在摩洛哥Tarfaya记录的OAE2间隔有很好的相关性，这意味着循环氧化还原变化跨越了两个半球。值得注意的是，在北半球和南半球的热带和亚热带地区，主要影响高纬度气候过程的倾角信号的存在进一步证实了先前假设的OAE2期间更强烈的经向翻转环流（MOC），并暗示了这一海洋环流主要转变的半球间/全球性质。
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 theinterhemispheric/globalnature of this major shift in oceanic circulation.
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影响因子：
2.9
作者：
S. Poulton;R. Raiswell
通讯作者：
S. Poulton;R. Raiswell
海洋缺氧事件 2 (OAE2) 期间全球碳循环扰动的天文限制
影响因子：
5.3
作者：
Li Yong-Xiang;Montañez Isabel P.;Liu Zhonghui;Ma Lifeng
通讯作者：
Ma Lifeng
影响因子：
5.8
作者：
W. Goodfellow;I. Jonasson
通讯作者：
W. Goodfellow;I. Jonasson
DOI：
10.1016/j.palaeo.2012.11.011
发表时间：
2013
期刊：
Palaeogeography, Palaeoclimatology, Palaeoecology
影响因子：
--
作者：
B. Bomou;T. Adatte;A. Tantawy;Haydon P. Mort;D. Fleitmann;Yongjian Huang;K. Föllmi
通讯作者：
B. Bomou;T. Adatte;A. Tantawy;Haydon P. Mort;D. Fleitmann;Yongjian Huang;K. Föllmi
影响因子：
6.5
作者：
Laskar, J.;Fienga, A.;Manche, H.
通讯作者：
Manche, H.