GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 3.3 ______ ___ GNGTS 2023 Non-real but realistic distribution of small high-frequency structures in 2D seismic data V. Frisicchio 1 , A. Del Ben 1 , M. Bellucci 2 , S. Blondel 3 , A. Camerlenghi 4 , R. Geletti 4 1 Department of Mathematics and Geosciences (DMG), University of Trieste, Trieste, Italy 2 Saipem SA, Montigny-le-Bretonneux, France 3 Department of Geosciences, University of Oslo, Oslo, Norway 4  National Institute of Oceanography and Experimental Geophysics (OGS), Trieste, Italy Introduction The generation of maps based on 2D seismic data involves a number of simplifications and approximations related to the fact that the algorithms used to generate the maps work by interpolations. Therefore, the maps are constrained to real values along the seismic lines and are extrapolated and largely smoothed in the intermediate areas where data are missing. This is a particular problem when dealing with small high-frequency structures (with an average diameter of a few tens or hundreds of meters), such as salt diapirs, magmatic or mud volcanoes, pockmarks, and sinkholes: in a map based on 2D seismic data, these structures are well constrained and are best mapped only along seismic profiles, while the map is inadequate in all other areas. In this work, we present alternative ways to produce isochrones maps that show the distribution of these types of structures, in particular we focused on the salt diapirs interpreted in two areas of the western Mediterranean.  High frequency structures: case study Salt diapirs are widespread in the Mediterranean due to the well-known Messinian Salinity Crisis (MSC) and associated salt tectonics: the MSC was triggered by a combination of tectonics, precession-driven oscillations and glacio-eustatic processes that restricted and closed the connection between the Atlantic and the Mediterranean, isolating the latter from the open ocean circulation (Geletti et al., 2014; Bellucci et al., 2021) . The event lasted from 5.96 to 5.33 Ma, resulted in the deposition of a thick evaporite sequence (Lofi et al., 2008, 2011; Geletti et al., 2014; Dal Cin et al., 2016) and ended with the Zanclean re-flooding of the Mediterranean basin. During the Late Messinian and Plio-Quaternary (PQ), intense halokinetic deformations led to the formation of many diapirs. Their distribution can be clearly illustrated by mapping the highly deformed base of the Plio-Quaternary.