River Olt   The River Olt, looking north to the beginning of the Olt gorge. These hills mark the transition from the mainly sedimentary sub-Carpathians to the mainly metamorphic Carpathians themselves. French, Romanian and British students recording the changing river characteristics of one of the Olt’s tributaries near Calimanesti. Gravel extractions for the construction of local hydro-electric power dams during the Communist period caused much change to the area’s hydrology. British and French students carry out river profile studies.