ORCID Profile
0000-0002-2728-0984
Current Organisation
University of Oxford
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Publisher: Elsevier BV
Date: 10-2020
Publisher: American Geophysical Union (AGU)
Date: 19-07-2011
DOI: 10.1029/2010PA002081
Publisher: American Geophysical Union (AGU)
Date: 04-2019
DOI: 10.1029/2018PA003546
Publisher: American Association for the Advancement of Science (AAAS)
Date: 09-09-2022
Abstract: Past large igneous province (LIP) emplacement is commonly associated with mantle plume upwelling and led to major carbon emissions. One of Earth’s largest past environmental perturbations, the Toarcian oceanic anoxic event (T-OAE ~183 Ma), has been linked to Karoo-Ferrar LIP emplacement. However, the role of mantle plumes in controlling the onset and timing of LIP magmatism is poorly understood. Using global plate reconstruction models and Lower Toarcian sedimentary mercury (Hg) concentrations, we demonstrate (i) that the T-OAE occurred coevally with Karoo-Ferrar emplacement and (ii) that timing and duration of LIP emplacement was governed by reduced Pangean plate motion, associated with a reversal in plate movement direction. This new model mechanistically links Earth’s interior and surficial processes, and the mechanism is consistent with the timing of several of the largest LIP volcanic events throughout Earth history and, thus, the timing of many of Earth’s past global climate change and mass extinction events.
Publisher: Elsevier BV
Date: 2023
Publisher: Geological Society of London
Date: 07-2002
Publisher: American Geophysical Union (AGU)
Date: 12-2001
DOI: 10.1029/2000PA000558
Publisher: Springer Science and Business Media LLC
Date: 07-2000
DOI: 10.1038/35019044
Abstract: In the Jurassic period, the Early Toarcian oceanic anoxic event (about 183 million years ago) is associated with exceptionally high rates of organic-carbon burial, high palaeotemperatures and significant mass extinction. Heavy carbon-isotope compositions in rocks and fossils of this age have been linked to the global burial of organic carbon, which is isotopically light. In contrast, ex les of light carbon-isotope values from marine organic matter of Early Toarcian age have been explained principally in terms of localized upwelling of bottom water enriched in 12C versus 13C (refs 1,2,5,6). Here, however, we report carbon-isotope analyses of fossil wood which demonstrate that isotopically light carbon dominated all the upper oceanic, biospheric and atmospheric carbon reservoirs, and that this occurred despite the enhanced burial of organic carbon. We propose that--as has been suggested for the Late Palaeocene thermal maximum, some 55 million years ago--the observed patterns were produced by voluminous and extremely rapid release of methane from gas hydrate contained in marine continental-margin sediments.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Hugh Jenkyns.