Sardinia morphological structure is the product of a succession of geological events, lasted for about half a billion years, each of which brought substantial structural changes up to the current set up. The first evolutionary period, undoubtedly the longest, embraces the entire Paleozoic. A geological era begun 570 million years ago with the Cambrian period, lasted for about 345 million years, ended finally in the Permian period, 225 million years ago.
In this time interval, sedimentary, tectonic, magmatic and erosive processes have occurred which overall made the island morphologically and chronologically heterogeneous. At present, the region is going through a phase of continentality, during which exclusive processes of erosive and sedimentary nature are carried out, which make it a stable formation and not very active, from a geological point of view.
To the protoliths located in southern (near Capo Spartivento) and northern Sardinia (in various sites in Gallura), has been attributed a probable Precambrian origin. The origin of the outcrops located in the Sulcis, attributed to the Precambrian or lower Cambrian, is instead dubious.
It is during the Ercinica orogenesis that the area of the future Sardinia is thus formed. The rocks emerged during this phase, the oldest found in Sardinia, have formed the “Basamento Sardo” which represents the most complete succession of the outcropping Paleozoic in Italy.
The end of the Ercinico cycle marks the beginning of a long period of stasis, both from the tectonic point of view and for the volcanic activities. This period continues throughout the Mesozoic (from 225 to 65 million years ago). Sardinia was then subjected to a new marine inlet that failed to fully submerged it, except in some interval of the Jurassic, during which the deposition of organogenic calcareous sediments occurred. The rocks generated are found in various outcrops of Sarcidano, Nurra, Ogliastra, Monte Albo and the island of Tavolara.
The current aspect of Sardinia derives above all from the very recent geological history (Pleistocene, the last 1.7 million years), dominated by the exogenous dynamics (river, wind, glacial processes etc ..) that have determined the actual physiography, in turn strongly conditioned and modified by the intense human activity.