THE PROGRADATION OF THE ALBANIAN DELTAIC PLAINS (DRIN, MATI, SEMAN AND VJOSA DELTAS): A MATTER OF THE LAST 500 YEARS?

Following an interdisciplinary approach, we have carried out a regional geomorphological survey along the Albanian shore - to the North, with the deltas of the Mati and the Drin, and to the south, with the deltas of the Seman and the Vjosa - in order to establish the evolution of the shoreline over the last 3500 years. This evolution consists of a prograding system led by three independent factors : sediment flux (avulsion, fluvial discharge, sediment load), marine dynamics (currents, actions of the waves) and the in-between accumulation area depending on the change of base-level and the pre-Holocene and Holocene in-filling. The geomorphological maps were based on two satellite images (SPOT 1995) (Fouache et al. 2001). Then, using unpublished geological profiles carried out by a group of Russian/Albanian geologists in 1960 (Dimo 1995), we have been able to identify a series of concentrations of heavy minerals – rutile, zirconium, chromium, ilmenite - probably corresponding to paleobeaches. Those profiles allowed nine points to be identified and samples have been taken from between 15 and 30 feet deep. In order to define the sediment environment of those deposits, we have paid particular attention to the study of sediments, pollens and diatoms. About twenty samples of wood or peat debris have been radiocarbon dated (14C AMS), all between 3050 +/- 50 BP and 340 +/- 50 BP. From the preliminary results of all these resources, we can infer that two-thirds of the deltaic progradation occurred over the last 500 years, starting in the 15th century, the beginning of the Ottoman period and the beginning of the Little Ice Age. As a hypothesis we propose that neo-tectonics, climatic fluctuations such as the Little Ice Age and socioeconomic fluctuations play a major role in the acceleration of the process, in spite of an important neo-tectonic subsidence effect.

References:

Dimo, Llazar. The evolution of Seman's Delta and their influence on the coastline in the Late Quaternary. Unpublished Report. Tirana, 1995.

Fouache, Eric et al. Recent Geomorphological Evolution of the Delta of the Seman and the Vjosa (Albania). Earth Surface Processes and Landforms 26, 793-802 (2001)