Constraints for an interpretation of the Italian geodynamics: a review

To properly frame the seismic data acquired with the CROP Project, the geophysical and geological characteristics of the Italian region and a review of magmatism are briefly illustrated and commented. A description of the crustal and lithospheric structure is coupled with a synthesis of the available geophysical data sets, namely: Bouguer gravity anomalies, heat flow data, magnetic anomalies, seismicity, tomography and present-day stress field. Several magmatic episodes with different geodynamic signifi-cance occurred in Italy. A review of magma-tism in the Alps and in the Apennines is provi-ded; igneous products are distinguished, in the Tyrrhenian and circum-Tyrrhenian region, in relation with the nature of the dominant mag-matic source. Finally, the tectonic evolution of the Alps and the Apennines is synthesised together with a comparison of the main morphological, structural and geodynamic features of these two orogens. All these datasets highlight a complex geo-dynamic setting characterised, apart from the relatively stable foreland areas, by two very different orogens: the Alps and the Apennines. The Alps represent a double-verging orogen with a long lasting geological evolution that show a quite well developed lithospheric root and a documented overthrusting of the Adriatic plate over the European plate from Cretaceous to present. The Apennines are rather a rapidly migrat-ing thrust belt, developed mainly in Neogene times during the eastward roll-back of the subducting Adriatic plate; this orogen is associated with a back-arc basin (Tyrrhenian Sea) characterised in some part by oceanic crust and high heat flow.