Annals of the University of Bucharest: Geography Series (Dec 2017)
Cerna River terraces between Bãile Herculane and Orsova
Abstract
This study displays a detailed analysis of Cerna river terraces along its final 20 km (its lower reach). The main working method was the field charting during a number of campaigns. The starting point were previous studies concerning Cerna river Valley, firstly those of Schafarzik (1891) and Popescu (1964) but also those referring to the Danube Valley (Posea and collaborators, 1963). Schafarzik found five fluviatile terraces pertaining to that sector, the same as Popescu, who, in addition wrote about the meadow step, 2-3 m high. We have identified seven steps and today the meadow is 4-7 m high against the river bed in certain sections, which makes it to be considered as the first terrace in those areas. Thus the number of levels is as high as eight in those areas. The best developed with respect to morphology but also as regards the surface are the 4-7 m and the 40-50 m steps. The 70-80 m terrace was identified only in Băile Herculane area and was named "Coronini Terrace” after the name of the respective plateau. We named the 110 m terrace "Terasa Stoghirul” after the name of the hill where it emerges, in the Cerna-Belareca confluence area. The 10-15 m terrace may be encountered only in the last 2-3 km of Cerna Valley at the outlet into the Porţile de Fier Lake. The 20-30 m terrace is also well developed, but only along the right side of the river and the 140-160 m terrace often displays erosion witnesses detached from the mountain sides. The 260-300 m terrace (the last one) is only encountered downstream Bârza (the last 8-9 km of the valley upstream the lake), clearly joining the 8th terrace of the Danube ("Ciucar” level according to Posea and collaborators, 1963). Except for the 260-300 m terrace, well rolled rocky places and gravel grounds were found on all the other steps, mainly made up of gneisses, limy breccie and limes.
