The paper reports the isochronous map (TWT-Two Way Times) of the Marne a Fucoidi (Cretaceous Inf.-Aptiano/Albiano) geological formation elaborated for the large region of the south-central offshore in the Adriatic sea known as Zona B. The map refers to the top of the geological formation which belongs to the Umbria-Marche geological succession. This geological formation has been discovered in nearly all the perforations drilled during the hydrocarbon exploration in the Zona B of Adriatic offshore and it presents a modest thickness but is a clear geological identity in the evolution of the basin. The studied geological domain lies almost entirely in Zone B and extends from the 44th parallel in the north almost to the Gargano promontory in the south and its area exceeds 22,000 sq. km.

For the map realization, all the deep wells and 2D seismic reflection sections available within the VIDEPI project – Visibility of petroleum exploration data in Italy have been considered and processed. The map has been elaborated at 1:100,000 scale and the total area was divided into 5 different sub-areas on which the plane position of the available seismic reflection sections and the wells have been reported. A detailed grid has been designed and each nodes reports the TWT value deduced by the 2D seismic reflection sections calibrated with well data. The 5 sub-areas were merged realizing the isochronous map which has been vectorized to make it useful in a GIS-Geographic Information System environment.

The velocity field of the area has been realized and the average velocity of this geological formation is around 2550 m/sec and the experimental values range from 1950 m/sec of Gargano Mare 1 well and 3326 m/sec of Bonaventura 1 well and seismic velocity above 3000 m/sec were confined to north-west sector of the investigated area. This map shows the deep structural shape of Umbria-Marche geological succession with the trend of principal anticlines and synclines and it can be helpful for supporting the exploration of new hydrocarbon and CO2 geological storage reservoirs.