Rhenium isotopes reveal enhanced rock organic carbon oxidation over the Toarcian Oceanic Anoxic Event
Madeleine Stow, Alexander J. Dickson, Julie Prytulak, Mathieu Dellinger, Victoria Alcock, Stephen P. Hesselbo, Geoff M. Nowell & Robert G. Hilton, IN: Nature Communications, https://doi.org/10.1038/s41467-026-71533-6
Weathering plays a central role in the geological carbon cycle. Silicate mineral weathering is invoked as a stabilizing feedback on CO₂ emissions, for example from volcanism during the emplacement of Large Igneous Provinces. However, modern-day studies show weathering can emit CO₂ during oxidation of rock organic carbon (OCpetro) in sedimentary rocks and function as a positive feedback on climate warming. Here the authors measure the rhenium isotope composition (δ¹⁸⁷Re) of Early Jurassic marine sediments to explore how OCpetro oxidation rates changed during warming across the Toarcian Ocean Anoxic Event (T-OAE).