Paleosuelos neogénos en el área de San Esteban de Gormaz - El Burgo de Osma: implicaciones sedimentológicas y palegeográficas

Zusammenfassung

Neogene deposits of the Osma Basin (Soria province) show characteristic of fossil soils. Facies analysis of these deposits show evidence of their deposition in a fluviolacustrine environment. The characteristics of Neogene deposits of the Osma Basin (Soria province) indicate that they are fossil soils. Two different subenvironments have been identified: a palustrine zone represented by limestones with ferruginous nodules, palustrine nodular limestone, calcretes and a shallow lacustrine zone formed by clotted-peliodal limestone, laminar stromatolitic limestone, algal biomicrite-biosparite. The above mentioned facies associations are genetically related with the floodplain of fluvial system, but particular characteristics are used in this study to infer parameters as palaeodepths of the flooded areas, water-table oscilations and edaphic processes. Lithological and textural evidence confirm the existence of four litostratigraphic units in the overal succession of the area. The observed sucession of vertical variations indicates modification of the seasonality of the Mediterranean type climatic pattern which dominated during the Neogene, displaying a tendency towards cooler and wetter seasons.