Sardinia is an island characterized by one of the most complete geologies in Europe and the entire Mediterranean area.
In just 24,000 square kilometers, it boasts the longest stratigraphic series in Italy, documenting a geological history dating back over 500 million years and preserving evidence of extraordinarily diverse events belonging to different geological cycles that took place between the Paleozoic and the recent Quaternary periods.
This geodiversity is clearly illustrated in the sequences of sedimentary, magmatic, and metamorphic rocks found throughout Sardinia and distributed more or less evenly throughout the region.
Also worth noting, among the numerous international features that characterize the Paleozoic crystalline basement and among the most important in Europe, is the presence of the most conspicuous metal mineralizations in Italy, as well as the geological existence of the oldest dated paleontological soils in Italy.

It was during the Paleozoic Era that the most significant geological events took place.
Among these, two orogenic cycles are worth mentioning: the Caledonian Cycle, during the Ordovician, and the Hercynian or Variscan Cycle in the Middle Carboniferous.
Of these, the second was the most important due to its objective consequences.
It is credited with the fundamental structuring of the Sardinian schistose-crystalline basement, which also constitutes an almost continuous and one of the best-preserved “sections” of the European “Hercynian Chain.”

In the Mesozoic and Cenozoic eras, however, there is ample evidence that Sardinia, together with its twin Corsica, was directly involved in the geological evolution of the western Mediterranean, as a fragment of continental crust that gradually detached itself during the Cenozoic era from the southern European margin and migrated, initially in a translational motion and subsequently in a counterclockwise rotational motion, towards its current position: the center of the Mediterranean.
These continental drift movements are also linked to impressive volcanic activity, which manifested themselves in all their unparalleled variety of products and facies, starting in the late Eocene, peaking in the lower Miocene, and continuing until the upper Pleistocene.

During the Miocene, between the Aquitanian and the Lower Messinian, three marine sedimentary cycles occurred during which the richest fossiliferous rocks of Sardinia were formed.
There are hundreds of species of fossil remains, often very well preserved and attributable to dozens of different systematic groups.
These include bivalves, gastropods, pteropods, cephalopods, echinoids, corals, algae, annelids, crustaceans, marine mammals, fish, and marine reptiles.
Equally varied and spectacular is the flora, whose fossilization is almost always directly or indirectly linked to explosive Miocene volcanic eruptions.
Two classic and emblematic examples are the petrified forests near Lake Omodeo, historically the richest, famous, and plundered, as the Perfugas forest in Anglona, with its palms, rutaceae, sapotaceae, anacardiaceae, cedars, cypresses, laurels, figs, elms, poplars, willows, oaks, magnolias, laurels, black locust trees, eucalyptus, and mushrooms.

Quaternary sedimentary deposits are the result of significant hot and cold climate fluctuations that are known to be linked to major glaciations.
For example, along coastal areas, sea level fluctuations caused by alternating glacial and interglacial periods in Sardinia (thickening of ice or partial melting) led to a retreat or a more or less extensive invasion of the sea.
The tangible result of these events was continental sedimentation, mainly in river, lake, wind, travertine, slope, cave, and brackish lagoon to coastal marine environments.
Very characteristic of this period are the marine deposits from about 100,000 years ago, underlying the eolian deposits, belonging to the so-called “Tyrrhenian Bench,” with fossil remains of mollusks typical of warm tropical seas, with species such as Strombus bubonius and Mytilus senegalensis, which currently live off the coast of Senegal.
Also very characteristic and important for the documentation they preserve are the ossiferous breccias within the eolian sandstones and cave deposits with remains of cervids, proboscids, birds, rodent mammals, primates, mustelids, antelopes, canids, reptiles, and amphibians.