New advances in the stratigraphy of Aptian oceanic anoxic events (Castro Urdiales, Basque-Cantabrian Basin, Spain)

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 Aptia...

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Detalles Bibliográficos
Autores: Fernández Mendiola, Pedro Ángel, Pérez Malo, Joanaitz, Owen, Hugh G., García Mondéjar, Joaquín
Tipo de recurso: artículo
Fecha de publicación:2023
País:España
Institución:Universidad del País Vasco
Repositorio:Addi. Archivo Digital para la Docencia y la Investigación
OAI Identifier:oai:addi.ehu.eus:10810/60292
Acceso en línea:http://hdl.handle.net/10810/60292
Access Level:acceso abierto
Palabra clave:black shale
Aptian
oceanic anoxic events
volcanism
Basque-Cantabrian basin
Descripción
Sumario: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) martinioides Zone. Biostratigraphy and chemostratigraphic calibration are based on ammonites, carbon isotopes and total organic carbon analyses, revealing consistency with the global Aptian reference framework. The Castro Urdiales black-shale levels of the lower to upper Aptian transition together with their encasing series are correlated with other Aptian sections of the Basque-Cantabrian Basin (northern Spain) and southeastern France. The Castro Urdiales black shales are correlated with the Aparein Level of the eastern Basque-Cantabrian Basin. Prior to this oxygen deficient episode, glauconite-and-ostreid facies were also deposited under oxic conditions during the Gutiolo volcanic event of the Basque-Cantabrian Basin. This volcanism correlates in part with the Cretaceous superplume eruptions of Ontong Java, Manihiki Plateaus and the North Atlantic opening as a result of increasing seafloor spreading rates.