Shoreline reconstruction since the Middle Holocene in the vicinity of the ancient city of Apollonia (Albania, Seman and Vjosa deltas)
Résumé
A geomorphological map was constructed, based on satellite imagery of the recent geomorphological evolution of the delta of the Seman and the Vjosa rivers, Albania. Results of the analysis of data collected from unpublished geological profiles carried out by Russian and Albanian geologists indicate that concentrations of heavy minerals are clearly correlated with palaeo-shorelines, particularly in six boreholes drilled in the vicinity of the ancient city of Apollonia (7th century BC-7th century AD). Study was mainly based on sedimentological, pollen and diatom analysis. About twenty samples of wood or peat debris have been 14C dated (AMS), all between 3050 ± 50 BP and 340 ± 50 BP. Based on this evidence, a new palaeogeographic reconstruction of the shoreline over the last 3500 years is proposed. Two-thirds of the deltaic progradation occurred over the last 500 years. As a hypothesis, climatic fluctuations such as the Little Ice Age and socioeconomic fluctuations could play a major role in the acceleration of the process, in spite of an important neotectonic subsidence effect.