Un ejemplo de llanura fluvio-deltaica influenciada por las mareas: el yacimiento de icnitas de Serrantes (Grupo Oncala, Berriasiense, Cuenca de Cameros, N. de España)

Abstract

The Late Jurassic-Early Cretaceous Cameros Basin comprises an expanded Tithonian to Early Albian stratigraphic record, mainly made up of fluvial and lacustrine systems, but also containing minor marine incursions. This basin is renowned because of preserving numerous ichnites sites, being the Berriasian Oncala Group one of the units that includes more of them. A sedimentological study of the deposits at the Serrantes site demonstrates that the ichnites are clearly associated with tidally-influenced fluvial-deltaic meandering channel and overbank deposits. The facies appearing in this outcrop are: 1) channelized beds, 2) lutites, 3) tabular sandstone beds, 4) black limestones, 5) laminated limestones with gypsum pseudomorphs. The ichnites are clearly associated to the siliciclastic deposits, especially to the lutitic facies, and are absent in the carbonate-evaporitic deposits.