Please use this identifier to cite or link to this item:
Title: Rapid light carbon releases and increased aridity linked to Karoo-Ferrar magmatism during the early Toarcian oceanic anoxic event
Authors: Font, Eric 
Duarte, Luís Vítor 
Dekkers, Mark J.
Remazeilles, Celine
Egli, Ramon
Spangenberg, Jorge E.
Fantasia, Alicia
Ribeiro, Joana 
Gomes, Elsa 
Mirão, José 
Adatte, Thierry
Issue Date: 2022
Publisher: Nature Research
Project: UIDB/50019/2020 
Serial title, monograph or event: Scientific Reports
Volume: 12
Issue: 1
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.
ISSN: 2045-2322
DOI: 10.1038/s41598-022-08269-y
Rights: openAccess
Appears in Collections:FCTUC Ciências da Terra - Artigos em Revistas Internacionais
I&D CITEUC - Artigos em Revistas Internacionais
I&D MARE - Artigos em Revistas Internacionais

Show full item record


checked on Sep 1, 2023


checked on Sep 2, 2023

Page view(s)

checked on Sep 25, 2023


checked on Sep 25, 2023

Google ScholarTM




This item is licensed under a Creative Commons License Creative Commons