The reusing of the CROP11 seismic data: new insight on the stratigraphic and structural setting of the Fucino and Piani Palentini basins

The long-offset seismic refraction/reflection data from CROP11-1999, which was harvested for deep seismic exploration, when reprocessed and integrated with other seismic reflection data, may give new insights into the main geological structures of the central Apennines. The Piani Palentini and Fucino basins are crossed by a sub-transect of the CROP11 seismic profile, which we interpreted from a geophysical-geological perspective. An integrated approach based on the stacked refraction convolution section and refraction tomography was used to carry out a new geophysical interpretation. The reprocessing allowed us to obtain a high resolution (about 15 m in distance and depth) P-waves seismic velocity 2D model and to image the refractor interface of the basin down to the depth of the Meso-Cenozoic carbonate substratum. The refraction outcomes, combined with the interpretation of the CROP11 seismic reflection profile and of other commercial seismic reflection profiles available in the studied area, allowed us to highlight a complex basin-fill architecture and stratigraphy. On the basis of the reconstructed tomography model and the reflection analysis, and of a comparison with previous reconstruction and stratigrafic studies on the Fucino basin reported in literature (Cavinato et al., 2002; Patacca et al., 2008; Patruno & Scisciani, 2021), we propose four seismo-facies separated by several unconformities and characterized by different Vp velocity values. In particular, above a high velocity, high amplitude sequence, directly over the Meso-Cenozoic carbonate substratum, we identified two intra-Messinian unconformities. These unconformities delimit a low velocity sequence, likely composed by fine/medium-grained deposits (clays and silts), and an overlayed highvelocity sequence related to the presence of coarser deposits. Above these deposits, the reflectors are more regular and show a fan geometry against the well known San Benedetto-Serrone-Gioia dei Marsi nomal fault. This latter sequence represents the Plio-Pleistocene post orogenic basin-fill deposit, controlled by the normal fault activity. The obtained model constitutes a geophysical-geological informative base for future research on seismic wave propagation and site response studies at the large scale of the Fucino Basin, one of the regions of the Italian territory with a high seismic hazard.