New chronostratigraphic constraints on the Lower Jurassic Pliensbachian−Toarcian boundary at Chacay Melehue (Neuquén Basin, Argentina) and the relationship to Karoo Large Igneous Province

AL-SUWAIDI, A.H., RUHL, M., JENKYNS, H.C., HESSELBO, S.P., CONDON, D.J., DAMBORENEA, S.E., MANCEÑIDO, M.O., ANGELOZZI, G.N., KAMO, S.L. Y RICCARDI, A.C.

Nature Scientific Records

SPRINGER

Lugar: Londres; Año: 2022

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 is 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 ~ 183.71 + 0.40/− 0.51 Ma for the Pliensbachian–Toarcian boundary, and 182.77 + 0.11/− 0.21 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.