Tracking magmatism and oceanic change through the early Aptian Anoxic Event (OAE 1a) to the late Aptian: Insights from osmium isotopes from the westernmost Tethys (SE Spain) Cau Core

Some of the major Carbon cycle perturbations Phanerozoic occurred during Aptian, in relation to magmatism. The highest temperatures reconstructed for Cretaceous Period correspond Oceanic Anoxic Event early Aptian (OAE 1a), an episode accelerated global change. Here we present a chemostratigraphic study based on osmium isotopes integrated with high-resolution Carbon-Oxygen stable isotope data from Cau Core (Western Tethys, SE Spain), including 6.4 Ma record late Aptian. This continuous and expanded section permits thorough understanding duration events, as well evaluation mechanisms triggering abrupt changes carbon cycles their interdependence. show that Large Igneous Province (LIP) magmatism initiated 550–750 kyr prior OAE 1a, persisted 1.4 Myr after event, influencing composition seawater 2.8 Myr. We Os encompassing 1a first time, demonstrate recovery exceptionally unradiogenic produced by dominance Ontong Java Plateau volcanism, was slow. Our results different time some asynchronous relationship between