Ancient Poliochni Geoarchaeological Research: Its proximity to the sea and the possible location of an ancient harbor (North Aegean Sea, Greece).

Ancient Poliochni is one of the oldest excavated cities in the Aegean Sea and its connection with the sea is indisputable and diachronic during the city habitation from 3500/3300 BC to 2000/1900 BC. The research focuses on the palaeogeographical evolution of the city valley, the coastal zone, and the nearshore seabed. On land, the study area is the lower part of the river valley located between the archaeological site and the foothills of the Agia Triada coastal hill. Data were acquired by geomorphological and geophysical research, drillings (up to 14.5 m depth) stratigraphical and paleontological analysis, and high accuracy topography using GNSS receivers and Unmanned Aerial Vehicles (UAVs). The marine survey extends to the entire Voroskopos (Poliochni) Bay including satellite image analysis, single-beam echo soundings, side-scan sonar seafloor detection and imaging, and visualization of special seabed features.

Ancient Poliochni was founded on a coastal terrace shaped by the erosive action of the waves on the hard formations of the Limnos Island geological basement. The seabed morphology and geology of the Poliochni Bay shows that it was part of the coast, during the city habitation, in a progressively flooded by the rising sea level coastal environment.