Role of Inherited Tectonic Structures on Gravity-Induced Slope Deformations: Inference from Numerical Modeling on the Luco dei Marsi DSGSD (Central Apennines)

A pre-existing and inherited geostructural setting plays a fundamental role in preparingand developing large-scale slope deformational processes. These structures affect the kinematics ofthe process, the geometrical characteristics, and the geomorphological evolution. In the ApennineBelt, several deep-seated gravitational slope deformations (DSGSDs) that have evolved under aclear structural control have been recognized during the last decades, but none with a continuousand well-defined basal shear zone (BSZ). The structurally-controlled DSGSD of Luco dei Marsirepresents the first case of a DSGSD in the Apennine Belt with a well-defined BSZ. Starting from adetailed study of the process and the reconstruction of a morpho-evolutionary model of the slope, aseries of numerical modelings were performed for the study of the DSGSD. The analyses allowedus to reconstruct: (i) the mechanism of the process, (ii) the rheological behavior of the rock mass,and (iii) the main predisposing factors of the gravitational deformation. Numerical modeling hasdemonstrated the significant role played by the inherited structures on the DSGSD and, in particular,the importance of an intensely jointed stratigraphic level in the development of the BSZ.