Milos Geology, in Greece: Milos is part of an area that comes under the Aegean Volcanic Arc. This arc is an alignment of volcanoes. These volcanoes were formed by the subduction of the African plate that is under the Aegean Sea. This arc encompasses the Gulf of Korinthos and the west coast of Turkey. The main districts that have volcanic activity are Methana-Poros, Milos, Nysiros and Santorini. The Milos district includes the Greek islands of Milos, Kimolos, Antimolos and Poliegos.
In terms of geological history, volcanic activity started in this area 5 million years ago. This volcanic activity explains why there is so much obsidian in Milos. Andesitic rocks can be found in the southwest portion of Milos.
There are both volcanic domes and dikes in Milos that come from the thermal cooling of lava. This cooling created the islets of Glaronissia and Kalojero near Milos. The volcanic rocks found in Milos were the result of extreme hydrothermal activity. This activity changed the chemical composition of the original rocks. It caused the formation of a large ore deposit of clay minerals.
These clay minerals have hugely benefited the economy of Milos. Milos helped Greece become the second largest world producer of bentonite, a clay mineral. The alteration of Milos due to volcanic activity is the reason behind the extreme colors and landscapes in Milos. It also created the beaches of Fyroplaka, Fyropotamos, and Plathiena. The volcanic nature of Milos is due to the heat-flux in the crust of the earth in this area.
These areas are called geothermal fields and these fields can be used to create energy. Milos or Greece has not used these geothermal fields to create geothermal energy yet. If you are interested in Geology, you can visit the Mining Museum of Milos that is located 1 Km from the port of Adamas.