Variaciones en el registro isotópico del carbono en dos secciones de edad Aptiense inferior en la zona de transición entre el Subbético Externo y el Subbético Medio (Cordilleras Béticas, Provincia de Jaén)

Abstract

The lower Aptian pelagic and hemipelagic sediments of the Carbonero Fm were deposited in the Southern Iberian Palaeomargin, within the transition between the External to Middle Subbetic palaeogeographic domains. The concrete area of deposition was a subsiding sector bounded by faults. A stratigraphic and sedimentological study of two nearby sections from this area (Solana de Morales and La Frontera) has revealed the existence of notable differences in their stratigraphic record, which are interpreted in terms of a different sedimentary context. Both sections include a lower Aptian episode of black shales, which is interpreted to represent the local record of the Oceanic Anoxic Event 1a (OAE1a). The d13Ccarb curves from both sections can be easily correlated, and also a good correlation is observed with respect to curves from other areas, which record the global carbon cycle perturbation related with the OAE1a. The discrepancies in the isotopic d13Ccarb record between the two sections are interpreted in terms of local differences in the sedimentary environment