Tectono-Stratigraphic setting of the Abruzzo Sub-Apennines along the Colledara-Montefino transect (Abruzzo-Italy)

East of the Gran Sasso chain, the sub-Apennine foothills, are characterized by extensive outcrops of turbidites belonging to the Laga and Cellino formations. Despite in the past decades they have undergone several investigations, the poorness of stratigraphic and petrographic data, and the complexity of the orogenic deformations left numerous unsolved questions. These latter concern the precise dating and the possible correlations between adjacent successions (which also imply problems of nomenclature), their basin of origin, and the amount of their tectonic translation. Our work tries to fill this gap of data starting from an original, and updated, geological survey of a 20 km long – 4 km wide, W-E trending, area straddling the Colledara-Montefino transect. This area, falls entirely within the 350 Penne geological Sheet, which will be surveyed in the coming years (CARG Project), therefore the mapping was mainly set on the stratigraphy of the 339-Teramo sheet, which contains the northern continuation of the studied structures. The fieldwork was carried out using digital devices, which led to collect a large amount of stratigraphic and structural data. The initial stratigraphic scheme, already very detailed, has been further implemented with the distinction of newly found facies associations and key-horizons. The high-grade stratigraphic resolution has allowed us to precisely identify the main folds and thrust faults, synthesized in a balanced geological section. The surface geology was subsequently used to constrain the interpretation of 11 seismic lines also calibrated at depth by the Logs of the public wells drilled for hydrocarbon exploitations (both sections and well-logs are available in the ViDEPI project). Their correlation allowed us to: i) recognize the unconformity between the Lower Pliocene and the Upper Pliocene successions, ii) describe the deep geometry of the outcropping thrusts, and iii) highlight the complexity of the whole thrust systems, which also includes several blind splays. Finally, a 3D subsurface geological model has been built, including the most important seismo-stratigraphic units from the top of the Triassic Dolostones to the top of Lower Pliocene turbidites and showing the geometry of the main tectonic structures.