Descripción e interpretación de las litofacies evaporíticas de Artesa de Segre (Eoceno Superior del NE de la Cuenca del Ebro)

Abstract

The evaporitic sequence of Artesa de Segre (Lleida) is related to the Noguera lacustrine system (Barbastro Fm, upper Eocene to Iower Oligocene). The evaporites are found in between continental paelogene sediments. Two main gypsum levels, separated by red shales, can be distinguished. Nodulose lithofacies are predominant, showing chicken wire structures and enterolitic belts. Selenithic and laminated facies are less abundants. The environmental context is assimilated to an alluvial fanlutitic plain-saline ephimeral /ake complex. Evaporitic percipitation and facies distribution is close related to base level changes, conditioning the thickness of water sheet, and to terrigenous supply