The Cape of Mourtzeflos marks the farthest northwest side of Lemnos. The volcanic formation called the volcanic dome of Mourtzeflos appears as an islet composed of volcanic rocks of tracheandesitic composition, but it is joined to the mainland by a small sandy strip, forming the tombolo’s unique geomorphological structure.

Approximately 20-21 million years old, the volcanic structure’s formation is linked to a series of volcanic structures that were created on Western Lemnos during that period. These distinctive volcanic domes were formed by ascending viscous magma with a high gas content that penetrated the pre-existing sedimentary rocks, folding and uplifting them. In many cases, the magma either reached the surface as thick lava or, after cooling at a shallow depth below the surface, was revealed by the erosion of the overlying geologic material, resulting in the formation of these distinctive volcanic structures in both cases.

The morphology of the coast and the separation of the islet from its adjoining land are the result of the movement of the NE-SW large Mourtzeflos strike-slip fault.

Tombolo is a coastal deposition formation composed primarily of sands and rounded pebbles (cobbles). The formation of a tombolo is formed by the impact of sea waves and the reduction of their transport capacity, resulting the deposition of sediments which are filling the seabed and its eventual emergence from the water surface.