EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

The Luco dei Marsi deep-seated gravitational deformation: first evidence of a basal shear zone in the central Apennine mountain belt (Italy) 

Emiliano Di Luzio1, Marco Emanuele Discenza2, Maria Luisa Putignano1, Mariacarmela Minnillo2, Diego Di Martire3, and Carlo Esposito4
Emiliano Di Luzio et al.
  • 1CNR - Consiglio Nazionale delle Ricerche, IGAG - Istituto di Geologia Ambientale e Geoingegneria. Area della Ricerca RM1, Via Salaria Km 29,3, Monterotondo Stazione - Roma, Italy (;
  • 2Geoservizi S.r.l. Via Luigi e Nicola Marinelli, 86025, Ripalimosani, Italy (;
  • 3Università di Napoli "Federico II", Distar - Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse. Via Cinthia, 21, 80126, Napoli, Italy (
  • 4Università di Roma "Sapienza”, Dipartimento di Scienze della Terra. Piazzale Aldo Moro, 5, 00185, Roma, Italy (

The nature of the boundary between deforming rock masses and stable bedrock is a significant issue in the scientific debate on Deep-Seated Gravitational Slope Deformations (DSGSDs). In many DSGSDs the deforming masses move on a continuous sliding surface or thick basal shear zone (BSZ) [1-3]. This last feature is due to viscous and plastic deformations and was observed (or inferred) in many worldwide sites [4]. However, no clear evidence has been documented in the geological context of the Apennine belt, despite the several cases of DSGSDs documented in this region [5-6].

This work describes a peculiar case of a BSZ found in the central part of the Apennine belt and observed at the bottom of a DSGSD which affects the Meso-Cenozoic carbonate ridge overhanging the Luco dei Marsi village (Abruzzi region). The NNW-SSE oriented mountain range is a thrust-related Miocene anticline, edged on the east by an intramountain tectonic depression originated by Plio-Quaternary normal faulting. The BSZ appears on the field as a several meters-thick cataclastic breccia with fine matrix developed into Upper Cretaceous, biodetritic limestone and featuring diffuse rock damage.

The gravity-driven process was investigated through field survey, aerial photo interpretation and remote sensing (SAR interferometry) and framed into a geological model which was reconstructed also basing on geophysical evidence from the CROP 11 deep seismic profile. The effects on slope deformation determined by progressive displacements along normal faults and consequent unconfinement at the toe of the slope was analysed by a multiple-step numerical modelling constrained to physical and mechanical properties of rock mass.

The model results outline the tectonic control on DSGSD development at the anticline axial zone and confirm the gravitational origin of the rock mass damage within the BSZ. Gravity-driven deformations were coexistent with Quaternary tectonic processes and the westward (backward) migration of normal faulting from the basin margin to the inner zone of the deforming slope.


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[6] Esposito C., Di Luzio E., Scarascia-Mugnozza G., Bianchi Fasani G., (2014). Mutual interactions between slope-scale gravitational processes and morpho-structural evolution of central Apennines (Italy): review of some selected case histories. Rendiconti Lincei. Scienze Fisiche e Naturali 25, 161-155.

How to cite: Di Luzio, E., Discenza, M. E., Putignano, M. L., Minnillo, M., Di Martire, D., and Esposito, C.: The Luco dei Marsi deep-seated gravitational deformation: first evidence of a basal shear zone in the central Apennine mountain belt (Italy) , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-5083,, 2021.