A new geodynamic model for the Sardinian segment of the Hercynian chain is presented. The improvement of knowledge regarding several geological, metamorphic, magmatic and geochronological aspects of the Sardinian Palaeozoic basement, mainly achieved in the last few years, allows us to propose a more complete picture of its evolution. The occurrence of remnants of an oceanic suture along a major tectonic lineament in northern Sardinia, as well as the products of Ordovician calc-alkaline magmatism, testifies to the presence, during the Lower Paleozoic, of an ancient (Precambrian- Cambrian) oceanic domain and its consumption along an Andean- type subduction zone. The following Carboniferous continental collision caused crustal stacking with Barrovian metamorphism and southward-migrating deformation from the suture zone toward the foreland. Early Carboniferous Culm-type facies sediments, deposited in the outermost zone of the chain, imply that continental collision took place earlier in the internal zone, from Late Devonian or Early Carboniferous. The collisional orogenic wedge experienced ductile extension during the Late Carhoniferous as a result of gravitational collapse of the thickened continental crust. Extensional tectonism enhanced the uplift of the chain and some regions underwent tectonic denudation or LP/HT metamorphism and somewhere anatexis. The emplacement of calc-alkaline batholiths and the development of Late Carboniferous - Early Permian molasse basins occurred during extension that prolonged throughout the Permian.

A complete section of the southern realm of the Variscan orogenic belt can be restored in the Corsica–Sardinia segment. Northern Corsica exposes a nonmetamorphosed Palaeozoic succession lying on Panafrican mica schist related to a microcontinent (most likely Armorica or from a microcontinent from the Hun superterrane) that had drifted away directly from Gondwana. These formations are thrust over the Variscan Internal Zone composed mainly of anatectic high-grade Palaeozoic formations that crop out from central Corsica to northern Sardinia; the metamorphic peak of the eclogite remnants has been dated at c. 420 Ma. The Variscan Internal Zone interpreted here as a collision zone, and also the Eovariscan suture, was intruded in Corsica by Mg–K granite from 345 to 335 Ma. The thrust of this Internal Zone onto the stack of parautochthonous nappes in central Sardinia is cross-cut by the Posada Asinara dextral shear zone. To the south, parautochthonous nappes overthrust the North-Gondwana margin which displays a possible Panafrican basement topped by an Iglesiente–Sulcis nonmetamorphic/anchimetamorphic Palaeozoic succession.

Over the last 25 years the Italian national geological mapping program of the Italian Geological Survey (CARG Project, italian: Progetto Carta Geologica) at 1:50,000 scale has led to significant improvements in the geological knowledge for the Island of Sardinia (Italy). As a result, about one half of the island now is covered by new geological maps with 1:10,000–1:25,000 accuracy and geological maps at the 1:50,000 scale whose explanatory notes are available electronically. At the beginning of the CARG Project a geological map for Sardinia Island at 1:200,000 scale was published [Carmignani, L. (1996). Carta Geologica della Sardegna (1:200.000). Servizio Geologico Nazionale, Regione Autonoma della Sardegna], summarizing all the geological information available at that time, and a book with explanatory notes for the map was later published [Carmignani, L., Oggiano, G., Barca, S., Conti, P., Salvadori, I., Eltrudis, … Pasci, S. (2001). Geologia della Sardegna: Note Illustrative della Carta Geologica della Sardegna in scala 1:200.000, Memorie Descrittive della Carta Geologica d'Italia (Vol. 60). Roma: Servizio Geologico d'Italia, 283 pp]. The enclosed Geological map of Sardinia at 1:250,000 scale incorporates all maps of the CARG Project, unpublished author studies and recently published maps and represents the most updated synthesis of an area characterised by a complex geological evolution that, with few exceptions, can be considered continuous during the last 540 Ma. The main events that influenced the geology of the island are the Variscan orogen that deeply involved the passive margin of North Gondwana and then the complex episodes that occurred in the present-day Mediterranean area after the accretion of Pangea up to the opening of the Tyrrhenian basin