The birth, formation and evolution of the Italian mountains is closely linked to the geological history of the European tectonic plate and of the African one.
The process that shaped the lands as we know them today began about two hundred million years ago, that is in what is scientifically called the Triassic period. According to the geological theory of plate tectonics, all the land masses were originally joined in a single great block called Pangaea. This enormous area of land would have been surrounded by a boundless sea called Panthalassa.
The geological history of Pangaea, according to scholars, would have been rather short; in fact the Earth's crust fractured at various points, splitting Pangaea into two great blocks: Laurasia and Gondwana.
Laurasia would have included North America, Europe and northern Asia, that is the portion of Asia without present-day India.
Gondwana would have been made up of the South American plate, Africa and India.
Within the complex movement of the individual plates, the key moment that gave rise to the Italian territory came when the block (or craton) formed by Africa began to move towards the southern margin of Laurasia, and in particular towards the portion that would later become present-day Europe. At the same time the North American plate, while staying attached to Europe for a certain period, began to move northwards. Meanwhile a block (present-day India) also broke away from the eastern block of Gondwana and, moving slowly, collided with the south-eastern area of Laurasia.
The phenomenon of Alpine-Himalayan orogeny is a complex process of uplift thrusts and subduction of plates that took place in the collision between the African craton and the European one.
The result of this immense collision is the evident folding of the Earth's crust. The marks of this folding are the Atlas Mountains in North Africa, the Pyrenees in Spain, the Apennines, the Alps, the Carpathians, the Dinaric Alps and the mountains of the Balkans.
It has to be said that at the time of the Alpine-Himalayan orogeny the Apennines formed the stretch of mountain chain that joined the Alps to the mountains of southern Spain. The present position of the Apennines and so of the Italian territory is due to the fact that this portion of land rotated anticlockwise, pivoting on what is today the so-called Ligurian gulf. In its rotation the Italian territory dragged along with it two large blocks, that of present-day Corsica and that of Sardinia.
The formation of the Italian mountains, both the Alps and the Apennines , is also the result of the uplift (Cretaceous period) of a portion of ocean floor made of rocks of basaltic origin, on which a few layers of carbonate sediments and fossils were deposited. This would explain the presence of the numerous fossils
found in some layers of our mountains.