The Pachymnos fault located towards the southeastern end of Lemnos, a few kilometers from Thanos settlement. West of the road can be seen the fault surface that forms an impressive steep slope extending to the sea.

Faults are geological structures formed when tensions inside the Earth’s crust overpass the limits of rock strength, forcing it to break.

The nearly vertical and smooth surface is the tectonic surface of the fault, created by recent seismic activity in the area which caused the volcanic rocks to break. On this surface, the traces of rock movement emerge as slip lines (scratches). These lines were formed by the opposing motion of the rocks and provide significant information about the fault’s seismic activity.