Seasonal rhythmites from a lower pleistocene lake in northeastern Spain
Abstract Chemical, sedimentological, ostracod and palynological data were obtained in order to investigate the rhythmic alternation of grey and beige silty layers, with the occasional presence of sandy layers, from a small lacustrine deposits in Catalonia. The deposit was formed in a shallow meromictic and slightly saline lake. Occasional floods from a nearby river brought in detritic material. The alternation of the silty layers is seasonal: pollen and ostracods demonstrate that the beige layers were deposited during spring and the grey layers towards the end of spring and after it, until the next spring. Graded bedding, bioturbation structures and iron nodules found in the deposit are also examined for further information on the formation of the deposit. Pollen suggests an age for the deposit ranging between the Senezian I (probably representing the Waalian Stage, after Elhai, 1969) and the Granada Interstadial (which is believed to correspond to the Holsteinian Stage by Florschutz et al., 1971).