Estimation of the Quaternary stream erosion in small drainage basins (Vâlcea sub-Carpathians and Olteţ Plateau, Romania)
Abstract: Stream erosion is a widely spread process in the Getic sub-Carpathians and Plateau (including the study sub-units). It is controlled by the high density of small drainage basins on a surface unit. Development of the 4th and 5th order valleys (according to Strahler’s system) in the sub-Carpathians and of the 3rd and 4th order in the Olteţ Plateau was also determined by the high altitude of hillslopes, up to 450 meters in the Vâlcea sub-Carpathians and to 250 meters in the Olteţ Plateau, a consequence of the strong downcutting performed by the Olt river and its main tributaries in this area (Olăneşti, Bistriţa, Cerna and Olteţ). Another control factor is the friable bedrock made of sedimentary deposits: conglomerate, gravel, sand, sandstone, marl, clay, tuffs etc. in the Vâlcea sub-Carpathians and Cândeşti strata (gravels with clayey lens of Villafranchian age) in the Olteţ Plateau.