The Paleogene deposits in the Serra d'Aubens (Segre valley) provide the eastermost outcrop of the assymetrical Ager sincline. Based on sedimentological and biostratigraphic analyses, four Ilerdian depositional sequences are distinguished. Compared with age-equivalent deposits of the Ager Valley, the two uppermost sequences (Ager and Llimiana, corresponding to the Baronia System) have a reduced thichness. As in the Ager Valley, these deposits consit of estuarine mixed carbonate-siliciclastic facie
