Imagine an island that emerges from the depths of the Mediterraneansurrounded by crystal clear waters that hold submerged treasures. This island is Usticsthe summit that emerged of an underwater volcano located in the Tyrrhenian Sea just under 70 km north-west of Palermo, in Sicily. Often obscured by the fame of his older sisters, Ustica boasts one geological history And naturalistic Of extraordinary importance, which makes it a real open -air laboratory for scientists and a paradise for nature lovers. His volcanic origin gives her a wild charm and one biodiversity surprising, both on the mainland and, above all, in its seabed, protected by one of the first Protected marine areas of Italy.
From a scientific point of view, Ustica is the result of a submarine volcanic activity that has started millions of years ago, between the Superior Pliocene and the Pleistocene Inferiore. It is not a “classic” volcano like theEtna or it Strombolinor is it part of a typical volcanic arch linked to subduction areas. Ustics Instead, it is a submarine volcanic complex that emerged thanks to a series of effusive eruptions and, to a lesser extent, explosive. Imagine the magmarock melted from the depths of the earth, which dates back slowly through fractures And volcanic conduits in the oceanic crust. By meeting the cold water of the sea, this magma solidifies quickly, forming the characteristics Pillow Lavas (“Cushion lave”), rounded structures that testify to the interaction between Lava and water. These lavas, rich in minerals such as pyroxen And olivinegive the rocks of Ustica their typical dark color.
Over the age of millions of years, subsequent eruptions and accumulations of volcanic material, such as lava flows, breaches and tuffs, have led to the gradual emergence of these submarine structures. This process built a great Sommerso volcanic buildingwhose base is located at approximately 2000 meters deepand of which Ustica is only the emerged part, which rises for about 240 meters on the sea level. His volcanic activity is considered extinct For hundreds of thousands of years, but its origin is still clearly visible in dark rocks, in the peak cliffs, in the numerous marine caves and in the same shape of the island.
Geologically, Ustica is an example of intra-placca volcanismthat is, a volcanic activity that is not directly linked to the margins of the busty plaques (as in the case of Etna, on the border between the African and Eurasian plaque, or the volcanoes that form the volcanic arches typical of subduction areas), but to a Hot spot or plume of magma that dates back to the earth’s cloak in a relatively stable area of the crust. This makes it a particularly interesting study case for geologists.
Ustica, nicknamed the “Black pearl“For the color of its volcanic rocks that contrast with the blue of the sea, it is a true casket of wonders. It was the first Protected marine area of Italy, established in 1986and for this reason its seabed are a paradise for divers and snorkelists, rich in ocean, corallary posidonia and an extraordinary variety of marine species. Its coasts are a succession of suggestive marine caves, like the famous Blue cavethe Green cave and the Grotta delle Boarwhich offer play of breathtaking light. The island also holds testimonies of very ancient human settlements, with the remains of a prehistoric village of the Bronze Age and a small but interesting archaeological museum which tells the long story. Ustica is therefore an island that enchants not only for its beauty, but also for its profound geological history and its naturalistic wealth, a real treasure to be discovered in the heart of the Mediterranean.
