Identificación de un intervalo de facies oscuras (equivalente al "nivel Selli") en la Fm Fardes (Subbético oriental de la Cordillera Bética)

During Aptian-Albian, the oriental Internal Subbetic was characterised by the sedimentation of the dark facies of the Fardes Fm. This formation is composed of dark pelagic facies (bluish and dark marls and lutites), radiolaritic facies and calcareous turbidites. The thick interval of dark facies observed within this formation, is interpreted as deposited under oxygen-depleted conditions. This interval, dated as early Aptian, represents the local record of the Ocean Anoxic Event la (OAE la). The biostratigraphic study and quantitative analysis of nannofossils enabled the precise identification of the "nannoconid crisis", whose onset clearly precedes the anoxic event. The particular physiography of the early Aptian oriental Internal Subbetic basin, characterised by half-grabens limited by listric faults, favoured the accumulation and preservation of organic carbon on the sea floor, the formation of radiolarites and the deposit of calcareous turbidites.