GNGTS 2021 - Atti del 39° Convegno Nazionale

9 GNGTS 2021 S essione 1.1 THE IMPORTANCE OF LONG-TERM GEOLOGIC RECORDS TO UNVEIL THE STRUCTURAL COMPLEXITIES OF THE UPPER CRUST: THE EXAMPLE OF THE 2016-2017 CENTRAL ITALY SEISMIC SEQUENCE AREA F. Capotorti 1 , M. Buttinelli 2 , L. Petracchini 3 , F.E. Maesano 2 , C. D’Ambrogi 1 , D. Scrocca 3 , M. Marino 1 , S. Bigi 3,4 , G.P. Cavinato 3 , M.T. Mariucci 2 , P. Montone 2 , D. Di Bucci 5 1 Istituto Superiore per la Protezione e la Ricerca Ambientale, Dip. Servizio Geologico d’Italia 2 Istituto Nazionale di Geofisica e Vulcanologia, Department of Seismology and Tectonophysics 3 Consiglio Nazionale delle Ricerche, Istituto di Geologia Ambientale e Geoingegneria 4 Università degli Studi di Roma La Sapienza 5 Dipartimento della Protezione Civile, Presidenza del Consiglio dei Ministri The RETRACE-3D project applied a holistic approach to seismotectonics combining constraints from field geological observations and geological maps, subsurface geophysical and deep well data acquired for hydrocarbon exploration, and other independent data (e.g. gravimetry ano- maly, tomographic images, seismicity; Di Bucci et al ., 2021). The result is a 3D geological model of the region struck by the 2016-2017 Central Italy seismic sequence, recently released to the public for further analyses and applications. It is constituted by six horizons recognized in the seismic profiles, bounding seven lithostratigraphic units from pre-Upper Triassic to Messinian, separated in fault blocks delimited by the major tectonic discontinuities (Fig. 1; RETRACE-3D Central Italy Geological Model, 2021). The architecture depicted by the 3D geological model, resulting from the great effort to re- concile all the constraints provided by the different types of data, pointed out a complex rela- tionship between normal faults mapped at the surface, thrusts developed during the Miocene- Pliocene Apennines orogenesis, and inherited normal faults developed during the Mesozoic ex- Fig. 1 - 3D geological model of the study area. Red surfaces - main thrusts: OAS – Sibillini, PAT – Patino, ACQ – Acquasanta, ACQs – Acquasanta internal splay, GRS – Gran Sasso. Dark blue surfaces - normal faults: VET – Vettore, NOR – Norcia, GOR – Monti della Laga-Gorzano, CAP – Capitignano, SGV – San Giovanni, PIZ – Pizzoli. Stratigraphic horizons: UMH – base Laga formation, VAS – top Scaglia variegata, FUC – top Marne a Fucoidi, MAS – top Calcare Massiccio, ITR – intra-Triassic horizon (modified after Buttinelli et al ., 2021).