Milos is said to belong to the pelagonic zone by the majority of those acquainted with the tectonic geology of Greece, although others would ascribe it to the pre-pelagonic zone.
In accordance with the theory of the lithospheric plate, it has been proved that Milos lies on the Eurasiatic Plate and 220 km. from the collision boundary with the African Plate. The latter is gradually moving under the former plate, at a speed of 2.5 cm. per year and at an angle of 35Æ to the horizontal. This movement is evident in Milos Island, especially in the south, where the land is slowly sliding down into the sea.