Rapid light carbon releases and increased aridity linked to Karoo-Ferrar magmatism during the early Toarcian oceanic anoxic event.

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Version: author
License: CC BY 4.0
Serval ID
serval:BIB_7DA2B22F26A9
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Rapid light carbon releases and increased aridity linked to Karoo-Ferrar magmatism during the early Toarcian oceanic anoxic event.
Journal
Scientific reports
Author(s)
Font E., Duarte L.V., Dekkers M.J., Remazeilles C., Egli R., Spangenberg J.E., Fantasia A., Ribeiro J., Gomes E., Mirão J., Adatte T.
ISSN
2045-2322 (Electronic)
ISSN-L
2045-2322
Publication state
Published
Issued date
14/03/2022
Peer-reviewed
Oui
Volume
12
Number
1
Pages
4342
Language
english
Notes
Publication types: Journal Article
Publication Status: epublish
Abstract
Large-scale release of isotopically light carbon is responsible for the carbon isotope excursion (CIE) of the Toarcian Oceanic Anoxic Event during the Lower Jurassic. Proposed sources include methane hydrate dissociation, volcanogenic outgassing of carbon dioxide and/or thermogenic methane release from the Karoo-Ferrar magmatic province (southern Africa). Distinct small-scale shifts superimposed on the long-term CIE have been interpreted as rapid methane pulses linked to astronomically forced climate changes. In the Peniche reference section (Portugal), these small-scale shifts correspond to distinct brownish marly layers featuring markedly high mercury (Hg) and magnetic mineral concentration. Total organic carbon and Hg increase are uncorrelated, which suggests input of Hg into the atmosphere, possibly released after the intrusion of the Karoo-Ferrar sills into organic-rich sediments. Enhanced magnetic properties are associated with the presence of martite, washed-in oxidized magnetite, inferred to be due to increased aridity on the continental hinterland. This study provides strong evidence for a direct link between the Karoo-Ferrar magmatism, the carbon-isotope shifts and the resulting environmental changes.
Keywords
Multidisciplinary
Pubmed
Web of science
Open Access
Yes
Create date
26/03/2022 6:09
Last modification date
09/04/2022 6:33
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