El terciario de los alrededores de Oviedo

Abstract

The Tertiary Basin of Oviedo is formed by an alluvial and lacustrine succession accumulateddunng the Paleogene in an asymmetric graben elongated in an E-W direction, whit a tectonically actif N margin. The successionrepresents amacrosequence, which is topped by a unit of calcareous conglomerates. The last ones constitue coalescent alluvial fans of small size, showing internal syntectonic unconfomities, and represent the culminant stage of diastrophic activity in the N margin of the basin. These coarse grained systems are mostly identical in lithology, internal structure, size, sequential arrangement, tectonic setting and probably in age to the Cuevas alluvial fan complex mentioned by García-Ramos et a1.(1982) in the northern margin of the Duero Basin. Inner, to the center of the basin, lacustrine limestones, variegated mudstones and evaporites are the dominant facies. The basa1 part of the serie has a Bartionan-Lower ludian age.