The Open UniversitySkip to content
 

Ocean circulation in the Toarcian (Early Jurassic), a key control on deoxygenation and carbon burial on the European Shelf

Ruvalcaba Baroni, Itzel; Pohl, Alexandre; van Helmond, Niels A. G. M.; Papadomanolaki, Nina M.; Coe, Angela L.; Cohen, Anthony S.; van de Schootbrugge, Bas; Donnadieu, Yannick and Slomp, Caroline P. (2018). Ocean circulation in the Toarcian (Early Jurassic), a key control on deoxygenation and carbon burial on the European Shelf. Paleoceanography and Paleoclimatology, 33(9) pp. 994–1012.

Full text available as:
[img]
Preview
PDF (Version of Record) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (4MB) | Preview
DOI (Digital Object Identifier) Link: https://doi.org/10.1029/2018pa003394
Google Scholar: Look up in Google Scholar

Abstract

The Toarcian Oceanic Anoxic Event (T-OAE, ∼183 My) was a long-lasting episode of ocean deoxygenation during the Early Jurassic. The event is related to a period of global warming and characterized by major perturbations to the hydrological and carbon cycles with high rates of organic matter burial in shelf seas. Ocean circulation during the Toarcian and its influence on marine biogeochemical cycles are still not fully understood. Here,we assess the spatial extent of anoxia in the NW Tethys Ocean during the T-OAE, the relationship with ocean circulation and the impact on organic carbon burial, using new and existing sedimentary records from the European Epicontinental Shelf (EES) in combination with general circulation model results. We demonstrate that bottom waters on the southwestern part of the shelf were mainly oxic during the T-OAE, while those in the northeastern basins were mostly anoxic or even sulfidic. Results for two ocean-atmosphere models (FOAM and MITgcm) suggest the presence of a strong clockwise gyre over the EES, which brought oxygenated equatorial waters from the Tethys Ocean to the southern shelf. The northward limb of the gyre was significantly weakened due to the rough bathymetry of the northern shelf, making this relative small region highly sensitive to local ocean stratification. These sluggish ocean dynamics promoted bottom water anoxia and enhanced burial of organic carbon in the northeastern basins, which accounted for 3–5% of the total carbon extracted from the ocean-atmosphere system as recorded by the positive carbon isotope shift.

Item Type: Journal Item
Copyright Holders: 2018 American Geophysical Union
ISSN: 1944-9186
Keywords: Toarcian Oceanic Anoxic Event; ocean circulation; European Shelf; organic carbon burial; Oxygenation; Early Jurassic
Academic Unit/School: Faculty of Science, Technology, Engineering and Mathematics (STEM) > Environment, Earth and Ecosystem Sciences
Faculty of Science, Technology, Engineering and Mathematics (STEM)
Item ID: 56484
SWORD Depositor: Jisc Publications-Router
Depositing User: Jisc Publications-Router
Date Deposited: 05 Sep 2018 09:51
Last Modified: 15 May 2019 15:37
URI: http://oro.open.ac.uk/id/eprint/56484
Share this page:

Metrics

Altmetrics from Altmetric

Citations from Dimensions

Download history for this item

These details should be considered as only a guide to the number of downloads performed manually. Algorithmic methods have been applied in an attempt to remove automated downloads from the displayed statistics but no guarantee can be made as to the accuracy of the figures.

Actions (login may be required)

Policies | Disclaimer

© The Open University   contact the OU