| Abstract: | The Siret River has the largest drainage basin (42 274 km2) in Romania. It gathers all the rivers from the eastern part of the Eastern Carpathians, a fact that causes marked asymmetry of the basin. This study is principally concerned with changes in the form of the longitudinal profile and the grain size variability introduced by the Carpathian tributaries. Channel sediment analyses considered the petrography, granulometry, and morphometry of the pebbles, relating these to the river bed and floodplain geometry and to some properties of the drainage basin. The following conclusions arise. The Siret River undergoes an intense regrading of its longitudinal profile, with marked aggradation between transects 24 and 26 (see Figures 1 and 2). This reflects selective accumulation of coarse material due to the massive contribution of the Carpathian tributaries. This phenomenon has been continuous throughout the Holocene, resulting in the gravel sheet formation of the Pericarpathian piedmont. |
