Prospección geofísica y geomecánica de la ribera de Biescas (Pirineos centrales): estructura del relleno sedimentario del fondo del valle glaciar

The large glaciated valleys of the Iberian Peninsula are located in the southern part of the Pyreneean-cantabric range, mostly in northern part of the Ebro basin. A common geomorphological feature in these glaciated valleys is the existence of glacial overdeepened basins in their medium and lower sections. Three geoelectrical units can be recognized in all the studied basins by Bordonau (1992) and Turu et al. (2007). Vertical Electrical resistivity Soundings where done and have been complemented by seismic soundings and geotechnical tests. The geomechanical data show us the existence of consolidated layers in the intermediate unit. Taking into account these new data, the intermediate unit is considered to be of glacial origin, and not the result of a glaciolacustrine infilling as it has been attributed until now.