New advances in the stratigraphy of Aptian oceanic anoxic events (Castro Urdiales, Basque-Cantabrian Basin, Spain)
Journal: Cretaceous Research
Year: 2022

The Aptian sedimentary deposits of the Castro Urdiales area in north Spain record an episode of disoxia/anoxia which postdates Oceanic Anoxic Event 1a (OAE 1a). Carbonate platform and overlying facies are analysed for stratigraphy, sedimentology, total organic carbon and carbon isotopes. Lower Aptian shallow-water limestones are covered by deeper-water marlstones and organic-carbon-rich black lutites of lower to upper Aptian, ranging from Dufrenoyia furcata Zone to Cheloniceras (Epicheloniceras)