New age constraints on the Lower Jurassic Pliensbachian-Toarcian Boundary at Chacay Melehue (Neuquén Basin, Argentina)

Aisha H Al-Suwaidi; Micha Ruhl; Hugh C Jenkyns; Susana E Damborenea; Miguel O Manceñido; Daniel J Condon; Gladys N Angelozzi; Sandra L Kamo; Marisa Storm; Alberto C Riccardi; Stephen P Hesselbo

doi:10.1038/s41598-022-07886-x

New age constraints on the Lower Jurassic Pliensbachian-Toarcian Boundary at Chacay Melehue (Neuquén Basin, Argentina)

Sci Rep. 2022 Mar 23;12(1):4975. doi: 10.1038/s41598-022-07886-x.

Authors

Affiliations

¹ Department of Earth Sciences, Khalifa University of Science and Technology, PO Box 12333, Abu Dhabi, UAE. aisha.alsuwaidi@ku.ac.ae.
² Department of Geology, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland.
³ Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, OX1 3AN, UK.
⁴ División Paleozoología Invertebrados, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, Argentina, CONICET, Paseo del Bosque S /N 1900, La Plata, Argentina.
⁵ British Geological Survey, Keyworth, NG12 5GG, UK.
⁶ Laboratorio de Bioestratigrafía, Área de Geociencias, YPF Tecnología S.A., Baradero S/N, 1925, Ensenada, Argentina.
⁷ Jack Satterly Geochronology Laboratory, Department of Earth Sciences, University of Toronto, 22 Ursula Franklin St., Toronto, ON, M5S 3B1, Canada.
⁸ Royal Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, PO Box 59, 1790 AB, Den Burg (Texel), The Netherlands.
⁹ Camborne School of Mines and Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK.

Abstract

The Pliensbachian-Toarcian boundary interval is characterized by a ~ 3‰ negative carbon-isotope excursion (CIE) in organic and inorganic marine and terrestrial archives from sections in Europe, such as Peniche (Portugal) and Hawsker Bottoms, Yorkshire (UK). A new high-resolution organic-carbon isotope record, illustrating the same chemostratigraphic feature, is presented from the Southern Hemisphere Arroyo Chacay Melehue section, Chos Malal, Argentina, corroborating the global significance of this disturbance to the carbon cycle. The negative carbon-isotope excursion, mercury and organic-matter enrichment are accompanied by high-resolution ammonite and nannofossil biostratigraphy together with U-Pb CA-ID-TIMS geochronology derived from intercalated volcanic ash beds. A new age of ~ 183.73 + 0.35/- 0.50 Ma for the Pliensbachian-Toarcian boundary, and 182.77 + 0.11/- 0.15 for the tenuicostatum-serpentinum zonal boundary, is assigned based on high-precision U-Pb zircon geochronology and a Bayesian Markov chain Monte Carlo (MCMC) stratigraphic age model.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Argentina
Bayes Theorem
Carbon Isotopes / analysis
Geologic Sediments*
Lead*

Substances

Carbon Isotopes
Lead