Polar record of Early Jurassic massive carbon injection

• Published in: Earth and Planetary Science Letters
• Main Authors: Suan, Guillaume, Nikitenko, Boris L., Rogov, Mikhail A., Baudin, François, Spangenberg, Jorge E., Knyazev, Valery G., Glinskikh, Larisa A., Goryacheva, Anna A., Adatte, Thierry, Riding, James B., Föllmi, Karl B., Pittet, Bernard, Mattioli, Emanuela, Lécuyer, Christophe
• Other Authors: Institut de Géologie et de Paléontologie, Université de Lausanne = University of Lausanne (UNIL), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Trofimuk Institute of Petroleum Geology and Geophysics of the Siberian Branch of the RAS (IPGG SB RAS), Siberian Branch of the Russian Academy of Sciences (SB RAS), Geological Institute of the Russian Academy of Sciences, Russian Academy of Sciences Moscow (RAS), Institut des Sciences de la Terre de Paris (iSTeP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Institute of Mineralogy and Geochemistry, The Institute of Diamond and Precious Metal Geology, British Geological Survey Keyworth, British Geological Survey (BGS), Institut universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), RAS (17, 24) CUS Regional Geological and Geophysical Studies of the Siberian Arctic Continental TGS-NOPEC Geophysical Company
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2011
• Subjects: Oceanic Anoxic Event; Pliensbachian-Toarcian; carbon isotope excursion; Arctic climate; sea level changes; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Arctic; Siberia
• Online Access: https://hal.science/hal-00638191; https://doi.org/10.1016/j.epsl.2011.09.050

International audience The Toarcian Oceanic Anoxic Event (T-OAE) (ca. 182 Myr, Early Jurassic) represents one of the best-recognized examples of greenhouse warming, decreased seawater oxygenation and mass extinction. The leading hypothesis to explain these changes is the massive injection of thermogenic or gas hydrate-derived (13)C-depleted carbon into the atmosphere, resulting in a >3 per mil negative carbon isotope excursion (CIE), accelerated nutrient input and dissolved oxygen consumption in the oceans. Nevertheless, the lack of a precisely dated record of the T-OAE outside low latitudes has led to considerable debate about both its temporal and spatial extent and hence concerning its underlying causes. Here we present new isotopic and lithological data from three precisely dated N Siberian sections, which demonstrate that mass extinction and onset of strong oxygen-deficiency occurred near synchronously in polar and most tropical sites and were intimately linked to the onset of a marked 6 parts per thousand. negative CIE recorded by bulk organic carbon. Rock Eval pyrolysis data from Siberia and comparisons with low latitudes show that the CIE cannot be explained by the extent of stratification of the studied basins or changes in organic matter sourcing and suggest that the negative CIE reflects rapid (13)C-depleted carbon injection to all exchangeable reservoirs. Sedimentological and palynological indicators show that the injection coincided with a change from cold (abundant glendonites and exotic boulder-sized clasts) to exceptionally warm conditions (dominance of the thermophyllic pollen genus Classopollis) in the Arctic, which likely triggered a rapid, possibly partly glacioeustatic sea-level rise. Comparisons with low latitude records reveal that warm climate conditions and poor marine oxygenation persisted in continental margins at least 600 kyr after the CIE, features that can be attributed to protracted and massive volcanic carbon dioxide degassing. Our data reveal that the T-OAE profoundly ...