A Southern Hemisphere Chronostratigraphic Framework for the Pliensbachian–Toarcian Carbon Cycle Perturbations
- 1Khalifa University, Earth and Planetary Science Department, Abu Dhabi, United Arab Emirates (aisha.alsuwaidi@ku.ac.ae)
- 2Department of Geology, and SFI Research Centre in Applied Geosciences (iCRAG), Trinity College Dublin, The University of Dublin, College Green, Dublin 2, Dublin, Ireland
- 3State Key Laboratory of Biogeology and Environmental Geology and Hubei Key Laboratory of Critical Zone Evolution, School of Earth Sciences, China University of Geosciences, Wuhan 430074, China
- 4Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, P.O. Box 59, 1790AB Den Burg, Netherlands
- 5Netherlands Earth Systems Science Centre (NESSC), Netherlands
- 6Department of Earth Sciences, University of Oxford, South Parks Road, OX1 3AN, Oxford, UK
- 7Camborne School of Mines and Environmental Sciences, University of Exeter, Penryn TR10 9FE, UK
- 8Analytical, Environmental and Geo-Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
- 9NERC Isotope Geosciences Laboratory, British Geological Survey, Keyworth NG12 5GG, UK
Lower Jurassic sedimentary successions from the Neuquén Basin, Argentina are unique in the abundance of radiometrically datable material (ash-beds) present, which can be tied to bio- and chemostratigraphic (carbon-isotope) zonations. Here, we present new U-Pb radio isotopic dates, integrated with carbon-isotope and Hg/TOC data, from three localities in Argentina (Arroyo Lapa, Arroyo Serrucho/Las Overas and Chacay Melehue) to generate a biostratigraphically calibrated composite carbon-isotope curve and geochronological framework for the Pliensbachian–Toarcian transition in South America. Using a Bayesian framework we present an age-depth model for this composite record and estimate the age and duration of key intervals extending from the Latest Pliensbachian carbon isotope excursion (CIE) through the Early Toarcian negative CIE. Using a statistical analysis of all available Karoo and Ferrar Large Igneous Province (LIP ) U-Pb and Ar-Ar radioisotopic ages we create a timeline of the key events and examine the timing of the carbon cycle perturbations specifically looking at potential links to peaks of extrusive emplacement of the Karoo and Ferrar LIP. The geochronological framework is further compared with other available radioisotopic dates from correlative sections, allowing for a more precise constraint and validation of the timing and duration of these Early Jurassic events.
How to cite: Al-Suwaidi, A., Ruhl, M., Kemp, D., Storm, M., Hesselbo, S., Jenkyns, H., Mather, T., Percival, L., and Condon, D.: A Southern Hemisphere Chronostratigraphic Framework for the Pliensbachian–Toarcian Carbon Cycle Perturbations, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15374, https://doi.org/10.5194/egusphere-egu24-15374, 2024.
