Abstract.

"Sea-level changes exert an important control on oceanic circulation and climate evolution. Researchers have proposed that sea-level rise favored accumulation of sediments enriched in organic carbon during oceanic anoxic events (OAEs), although high-frequency sea-level changes and their controlling mechanism have remained poorly constrained. Here we present a detailed sedimentological and geochemical study on Aptian (Lower Cretaceous) shallow-water carbonates of the Dariyan Formation exposed in the Zagros fold belt of southern Iran. [...]".

Source: Science Direct
Authors: Yiwei Xu et al.
DOI: https://doi.org/10.1016/j.gloplacha.2023.104236

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Abstract.

"The Cretaceous Oceanic Anoxic Event 2 (OAE2) is a greenhouse episode of severe marine anoxia at the Cenomanian-Turonian boundary. This time interval is characterized by rising sea surface temperature, enhanced marine biological productivity, and widespread occurrence of organic-rich black shales. With an export of biological production to the deep ocean, organisms consume vast amounts of oxygen and subsequently utilize nitrate and sulfate as electron acceptors in organic matter degradation, thereby affecting biogeochemical cycles of nitrogen and sulfur. [...]".

Source: Science Direct
Authors: Ruixiang Zhai et al.
DOI: https://doi.org/10.1016/j.gloplacha.2023.104182

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Abstract.

"At Site U1516 (Mentelle Basin, southeast Indian Ocean, offshore western Australia), the International Ocean Discovery Program (IODP) Expedition 369 recovered an almost complete pelagic record of the Upper Cretaceous, including the Oceanic Anoxic Event 2 (OAE 2). To better understand paleoenvironmental changes across OAE 2, 32 samples were analysed for benthic foraminiferal abundance data that represent one of the few benthic foraminiferal datasets spanning the OAE 2 in the southern high latitudes. [...]".

Source: Science Direct
Authors: Erik Wolfgring et al.
DOI: https://doi.org/10.1016/j.cretres.2023.105555

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Abstract.

"This paper reviews global records of anoxic events of the Middle Devonian – earliest Mississippian, as well as the possible triggers and controls of these events. These “anoxic events” are complex multistage paleoenvironmental disturbances manifested in multiple proxies, which we showcase with the Horn River Group (HRG) – a succession of basinal organic-rich shales and cherts deposited during the latest Eifelian – earliest Late Frasnian(∼386–373 My ago) on the western continental margin of Laurentia near the paleo-equator. [...]".

Source: Science Direct
Authors: Pavel Kabanov et al.
DOI: https://doi.org/10.1016/j.earscirev.2023.104415

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Abstract. 

"Oceanic Anoxic Events (OAEs) are important geological events that may be analogues to future climate-driven deoxygenation of our oceans. Much of the global ocean experienced anoxic conditions during the Cenomanian–Turonian OAE (OAE2; ∼94 Ma), whereas the Western Interior Seaway (WIS) experienced oxygenation at this time. Here, organic geochemical and palynological data generated from Cenomanian–Turonian age sediments from five sites in the WIS are used to investigate changing redox and ecological conditions across differing palaeoenvironments and palaeolatitudes. [...]".

Source: Science Direct
Authors: Libby J. Robinson et al.
DOI: https://doi.org/10.1016/j.palaeo.2023.111496

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Abstract. 

"Oceanic anoxic events (OAEs) are considered as periods of oxygen deficiency in many oceans; accompanied by accumulation of organic-rich black shales. Mesozoic anoxic events were recognized based on the presence of black shales that are rich in organic matter. The most significant anoxic events during the Mesozoic are the Early Toarcian, the Early Aptian, and the Cenomanian–Turonian. The less significant events are the Valanginian-Hauterivian, the Hauterivian-Barremian, the Aptian-Albian, the Late Albian, the Albian-Cenomanian, and the Coniacian-Santonian. [...]".

Source: Springer Nature
Authors: Tarek Anan & Adam El-Shahat 
DOI: https://doi.org/10.1007/978-3-030-95637-0_7

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Abstract. 

"The Cenomanian-Turonian (Late Cretaceous) climate warming was closely coupled to profound perturbations of biogeochemical cycles and ecosystems. The occurrence of organic matter-rich sediments across various depositional environments of the proto-North Atlantic hereby marks severe oxygen-deficient conditions, culminating in Oceanic Anoxic Event (OAE 2) at the Cenomanian/Turonian boundary. Here we combine bulk, isotope and molecular geochemical techniques to characterize trends in organic matter accumulation and its relationship to biogeochemical cycling (nitrogen, carbon) and marine phytoplankton community shifts [...]". 

Source: Science Direct
Authors: Wolfgang Ruebsam & Lorenz Schwark
DOI: https://doi.org/10.1016/j.gloplacha.2023.104117

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Abstract. 

"The impact of global climate events on local ecosystems can vary spatially. Understanding this potential heterogeneity can illuminate which environments will be most impacted and the proximal drivers of ecosystem responses. Cenomanian–Turonian marine deposits of the Western Interior Seaway (WIS) record paleoceanographic changes associated with the Greenhorn transgression and the onset of Oceanic Anoxic Event 2 (OAE2). They provide an ideal setting to study basin-wide paleoecological responses during a global perturbation. [...]".

Source: Cambridge University Press
Authors: Raquel Bryant & Christina L. Belanger
DOI: https://doi.org/10.1017/pab.2022.47

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Abstract.

"The late Pliensbachian to early Toarcian was characterized by major climatic and environmental changes, encompassing the early Toarcian Oceanic Anoxic Event (T-OAE, or Jenkyns Event, ∼183 Ma) and the preceding Pliensbachian–Toarcian boundary event (Pl/To). Information on seawater redox conditions through this time interval has thus far come mainly from European sections deposited in hydrographically restricted basins, and hence our understanding of the redox evolution of the open ocean (and in particular Panthalassa – the largest ocean to have existed) is limited. [...]".

Source: Science Direct 
Authors: Wenhan Chen et al.
DOI: https://doi.org/10.1016/j.epsl.2022.117959

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Abstract. 

"Ocean acidification causes biocalcification stress. The calcium isotope composition of carbonate producers can archive such stress because calcium isotope fractionation is sensitive to precipitation rate. Here, we synthesize morphometric observations of planktic foraminifera with multi-archive calcium isotope records from Gubbio, Italy and the Western Interior Seaway spanning Cretaceous Ocean Anoxic Event 2 (~94 million years ago). Calcium isotope ratios increase ~60 thousand years prior to the event. [...]". 

Source: Nature
Authors: Gabriella D. Kitch et al.
DOI: https://doi.org/10.1038/s43247-022-00641-0

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