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In the last 15 years, several Eni-Agip multidisciplinary studies were focused on the buried Messinian-Pleistocene succession of the eastern Po Plain and northern Adriatic Sea. A detailed revision of the biostratigraphy, chronostratigraphy, sedimentology, seismic interpretation and sequence stratigraphy was performed using the very large Eni subsurface dataset including regional 2D and 3D seismic surveys and over 500 deep wells. The new basin-scale geological model of the area is presented in this paper. During the Messinian and the Plio-Pleistocene the eastern sector of the Po Plain and the northern Adriatic Sea were part of the northern Apennine foreland basin. In this time span, the tectono-sedimentary evolution of

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The Messinian Salinity Crisis (MSC) involved the progressive isolation of the Mediterranean Sea from the Atlantic between 5.97 and 5.33 Ma, and a sea‐level fall whose timing, modalities, and magnitude remain actively debated. At that time, the central Mediterranean was undergoing strong tectonic activity due to the rollback of the Adria slab and eastward migration of the Apenninic belt. The combined effects of the post‐evaporitic MSC sea‐level drop and morphostructural changes (due to the Intra‐Messinian phase) resulted in a regional unconformity, which shows erosive markers and conformable relationships with the Messinian and Mio–Pliocene boundary in the Po Plain and Northern Adriatic Foreland. Here, we produce a palaeotopographic reconstruction of the Po Plain‐Northern Adriatic region (PPNA) during the Messinian peak desiccation event based on such regional unconformity. We mapped this surface through wells and 2D seismic data form Eni's private dataset. The unconformity shows V‐shaped incisions matching the present‐day southern Alpine valleys and filled with Messinian post‐evaporitic and Pliocene deposits, suggesting that the modern drainage network is at least of late Messinian age. The Messinian unconformity has been restored to its original state through flexural‐backstripping numerical modelling. The resulting landscape suggests a maximum sea‐level drop of 800–900 m during the MSC peak, and is consistent with stratigraphic and sedimentologic data provided by previous works. The modelled shoreline separates the subaerially eroded land from an elongated basin composed by two ca. 400 and 1,000 m deep depocentres during the maximum sea‐level drop. These results suggest that the Mediterranean was split in at least three sub‐basins subject to independent base levels, fresh‐water budgets, and flexural responses during the maximum lowstand.

Italy is the most hydrocarbon endowed country of southern Europe, with total discovered reserves (produced þ remaining) of 1840 million barrels of oil and 30 trillion ft 3 of gas. The production of oil amounts to 43.2 million barrels per year, about 75% of which comes from the Val d'Agri Field in the southern Apennines.

The offshore Adriatic Basin holds more than 50% of Italian gas reserves together with significant volumes of oil. A number of large and giant‐size biogenic gasfields and medium to large oilfields have been discovered here during the past 60 years. Two petroleum systems have been identified: a Plio‐Pleistocene biogenic gas system, and an Upper Triassic – Lower Jurassic oil system. These systems are described in this paper within a regional geological framework, with particular focus on petroleum system elements (source, reservoir, seal, trap and charge). The biogenic gas play was for several decades the prime focus of Italian E&P efforts throughout the Adriatic area but is now mature, and significant additional discoveries are unlikely to be made without a breakthrough in DHI (direct hydrocarbon indicator) technology. The Mesozoic oil play is as yet unproved in the northern Adriatic area, where large anticlinal structures at depths of up to ca. 6000 m are available for exploration and constitute high‐risk – high‐reward targets. By contrast, the play is proved in the Central and Southern Adriatic where several oilfields are currently producing. Exploration targets still exist here and may generate medium‐sized discoveries although the prevalent heavy‐oil phase may jeopardize their economic value.

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