Abstract. 

"Mesozoic oceanic anoxic events are recognized as widespread deposits of marine organic-rich mudrocks temporally associated with mass extinctions and large igneous province emplacement. The Toarcian Oceanic Anoxic Event is one example during which expanded ocean anoxia is hypothesized in response to environmental perturbations associated with emplacement of the Karoo–Ferrar igneous province. However, the global extent of total seafloor anoxia and the relative extent of euxinic (anoxic and sulfide-rich) and non-euxinic anoxic conditions during the Toarcian Oceanic Anoxic Event are poorly constrained. [...]".

Source: Nature
Authors: Alexandra Kunert & Brian Kendall
DOI: https://doi.org/10.1038/s41467-023-36516-x

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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. 

"The early Toarcian Oceanic Anoxic Event (T-OAE, ~183 Ma) was characterized by marine deoxygenation and the burial of organic-rich sediments at numerous localities worldwide. However, the extent of marine anoxia and its impact on the sulfur cycle during the T-OAE is currently poorly understood. Here, stable sulfur isotopes of reduced metal-bound sulfur (δ34Spyrite) and pyrite sulfur concentrations (SPY) have been analyzed across the Pliensbachian-Toarcian boundary (Pl-To) and the T-OAE from the Sakahogi and Sakuraguchi-dani sections (Japan), which were deposited in the deep and shallow Panthalassic Ocean, respectively. [...]".

Source: Science Direct 
Authors: Wenhan Chen et al.
DOI: https://doi.org/10.1016/j.gloplacha.2022.103884

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Abstract.

"The Toarcian Oceanic Anoxic Event (T-OAE; ~ 183 Ma) represents an episode of marine anoxia that lasted for several hundred thousand years. Abiotic factorscontributing to the formation of the T-OAE, such as global warming, changes in weathering intensity, or sea-level change, are associated with a marked change in carbon cycling. While these factors are well studied, detailed palynological data, including marine and terrestrial palynomorphs, is still missing. Here we present comprehensive palynological data from the sedimentologically and geochemically well constrained T-OAE section in Dormettingen (SW Germany). [...]".

Source: Science Direct 
Authors: Francesca Galasso et al.
DOI: https://doi.org/10.1016/j.revpalbo.2022.104701

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Abstract.

"The early Toarcian, as registered in a variety of sedimentary archives, was characterized by an abrupt negative carbon-isotope excursion (CIE) typically superimposed on a long-term positive trend, and was accompanied by significant climatic and environmental changes. However, the changes in continental weathering influx and oceanic deoxygenation in shallow waters and their possible role in causing carbonate-platform crises in low latitudes remains poorly constrained. [...]".

Source: Science Direct 
Authors: Zhong Han et al.
DOI: https://doi.org/10.1016/j.gloplacha.2022.103887

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Abstract.

"Many aspects of the supposed hyperthermal Toarcian Oceanic Anoxic Event (T-OAE, Early Jurassic, c. 182 Ma) are well understood but a lack of robust palaeotemperature data severely limits reconstruction of the processes that drove the T-OAE and associated environmental and biotic changes. New oxygen isotope data from calcite shells of the benthic fauna suggest that bottom water temperatures in the western Tethys were elevated by c. 3.5 °C through the entire T-OAE. [...]"

Source: Scientific Reports
Auhtors: C. V. Ullmann et al.
DOI: 10.1038/s41598-020-63487-6

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Abstract.

"For this study, we generated thallium (Tl) isotope records from two anoxic basins to track the earliest changes in global bottom water oxygen contents over the Toarcian Oceanic Anoxic Event (T-OAE; ∼183 Ma) of the Early Jurassic. The T-OAE, like other Mesozoic OAEs, has been interpreted as an expansion of marine oxygen depletion based on indirect methods such as organic-rich facies, carbon isotope excursions, and biological turnover. Our Tl isotope data, however, reveal explicit evidence for earlier global marine deoxygenation of ocean water, some 600 ka before the classically defined T-OAE. "

Source: PNAS
Authors: Theodore R. Them et al.
DOI: 10.1073/pnas.1803478115

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Abstract.

"The expansion and contraction of sulfidic depositional conditions in the oceans can be tracked with the isotopic composition of molybdenum in marine sediments. However, molybdenum-isotope data are often subject to multiple conflicting interpretations. Here I present a compilation of molybdenum-isotope data from three time intervals: the Toarcian Oceanic Anoxic Event about 183 million years ago, Oceanic Anoxic Event 2 about 94 million years ago, and two early Eocene hyperthermal events from 56 to 54 million years ago. [...]"

Source: Nature Geoscience
Authors: Alexander J. Dickson
DOI: 10.1038/ngeo3028

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Abstract.

"Chemical weathering consumes atmospheric carbon dioxide through the breakdown of silicate minerals and is thought to stabilize Earth’s long-term climate. However, the potential influence of silicate weathering on atmospheric pCO₂ levels on geologically short timescales (10³–10⁵ years) remains poorly constrained. Here we focus on the record of a transient interval of severe climatic warming across the Toarcian Oceanic Anoxic Event or T-OAE from an open ocean sedimentary succession from western North America. [...]"

Source: Scientific Reports
Authors: Theodore R. Them et al.
DOI: 10.1038/s41598-017-05307-y

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Abstract.

"The Toarcian Oceanic Anoxic Event (T-OAE) was characterized by a major disturbance to the global carbon(C)-cycle, and depleted oxygen in Earth’s oceans resulting in marine mass extinction. Numerical models predict that increased organic carbon burial should drive a rise in atmospheric oxygen (pO₂) leading to termination of an OAE after ∼1 Myr. Wildfire is highly responsive to changes in pO₂ implying that fire-activity should vary across OAEs. Here we test this hypothesis by tracing variations in the abundance of fossil charcoal across the T-OAE.  [...]"

Source: Nature Communications
Authors: Sarah J. Baker et al.
DOI: 10.1038/ncomms15018

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