El problema del Neógeno superior en la Cuenca del Dueronuevos datos paleontológicos (invertevrados) en el sector Peñafiel-Almazán

Abstract

Together with the general lithostratigraphic characteristics of the Neogene of the southeast sector of the Duero Basin, new paleontological data are provided (Gastropoda and Ostracoda) which demarcate a succession of events and changes in the assemblages through out the general stratigraphie column. There are several outstanding taxons of Gastropoda such as Hydrobia schlosseri, H. gr. deidieri, Valvata, Bithynia, Planorbis, Melanopsis and Theodoxus, Regarding the Ostracoda, the appearence was noted specially of IParacandona, Gen. indet. sp. 1, Lineocypris, Subulacypris and Candona aff. bitruncata. As well as estabUshing the correlation between the different sections, the paleontological group also points to a more modern age than those of the beds situated towards the centre of the basin; this would not conflict with the general deposit slope of such beds and their relation with the topographic level. The presence of forms attributable to Cyprideis torosa, in the Valles de Fuentidueña poses a chronostratigraphic problem and suggests the need to revise the age of the bed or the Ostracoda distribution.