Abstract The European Marine Observation and Data Network (EMODnet) Project provides freely available data on European seas. The main purpose of EMODnet is to overcome the fragmentation and dishomogeneity of the available data, providing access to a harmonized and interoperable database. The EMODnet Geology Lot includes information at multiple scales on the seabed and its substrate ( http://www.emodnet-geology.eu/ ). The dataset on ‘Geological events and probabilities’ collects information on landslides, earthquakes, volcanic structures, active tectonics, tsunamis and fluid emissions. The Geological Survey of Italy, which coordinates the collation of ‘Geological events and probabilities’ data, provided guidelines to compile layers complemented by comprehensive and detailed patterns of attributes for each feature in order to characterize each type of geological event. Occurrences of events are often associated with each other, particularly in tectonically active areas. Geological events affect both submerged and coastal environments. Data gathered by EMODnet Geology provide a good basis for further studies, contributing to the outlining of different tectonic settings and providing support to the use of marine resources, as well as to the management of marine-coastal areas particularly regarding the identification and assessment of geological and environmental hazards.

ABSTRACT The Pliocene–Quaternary igneous record of the Tyrrhenian Sea area features a surprisingly large range of compositions from subalkaline to ultra-alkaline and from ultrabasic to acid. These rocks, emplaced within the basin and along its margins, are characterized by strongly SiO 2 -undersaturated and CaO-rich to strongly SiO 2 -oversaturated and peraluminous compositions, with sodic to ultrapotassic alkaline and tholeiitic to calc-alkaline and high-K calc-alkaline affinities. We focused on the different models proposed to explain the famous Roman Comagmatic Region, part of the Quaternary volcanism that spreads along the eastern side of the Tyrrhenian area, in the stretched part of the Apennines thrust-and-fold belt. We reviewed data and hypotheses proposed in the literature that infer active to fossil subduction up to models that exclude subduction entirely. Many field geology observations sustain the interpretation that the evolution of the Tyrrhenian-Apennine system was related to subduction of the western margin of Adria continental lithosphere after minor recycling of oceanic lithosphere. However, the lateral extent of the subducting slab in the last millions of years, when magmatism flared up, remains debatable. The igneous activity that developed in the last millions of years along the Tyrrhenian margin is here explained as originating from a subduction-modified mantle, regardless of whether the large-scale subduction system is still active.