Fluvial terrace formation in mountainous areas: (1) Influence of climate changes during the last glacial cycle in Albania

Abstract

This work analyses terraces formation from the case of Albanian rivers. An allostratigraphy study of the fluvial terraces is combined with new numerical dating. 30 14C and 4 10Be new dated sites along four rivers and 45 ages previously acquired along three other rivers were used to define terrace chronologies at the scale of the whole Albania. Few terrace remnants are related to stages older than the last glacial period and are older than 194 ± 19 ka. Terrace level (T1) includes plain-like terraces and T1 is related to a rapid succession of valley incision and valley fill that occurred during the warm Holocene climatic optimum. The other nine terrace levels (T2 to T10) formed during the last glacial period (MIS 5d to end of MIS 2). Terraces T2, T6 and T7 formed nearly synchronously with interstadial transitions toward warmer and wetter conditions. The formation of terraces T3, T4, T5 and T8 (<60 ka) coincide with the warm climatic excursions of the Heinrich events. This result suggests that these short climatic events strongly punctuate the geomorphologic dynamics of rivers in mountainous areas.