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On 19 March 2010, a 4 million m3 landslide occurred at Poggio Baldi, a small village in the Santa Sofia municipality, central Apennines (Forlì-Cesena, Italy). The landslide caused severe damages to some homes and obstructed both the SS310 national road and the Bidente river. The Poggio Baldi landslide arose in the "Marnoso-Arenacea Romagnola" formation composed of a pelitic-arenaceous turbiditic sequence. The landslide was classified as a rotational landslide, evolving into a partially confined flow-like landslide and causing the reactivation of the deposit of a previous landslide that took place in 1914. This paper reports a study of the phenomena currently occurring on the 100-m high main scarp of this landslide complex. The aim of the study was to assess ground changes that occurred on the upper scarp from 2015 to 2018 and to infer a preliminary evolutionary model capable of supporting short-term landslide scenarios. For this purpose, multi-station terrestrial laser scanner surveys were performed in 2015, 2016, 2017, and 2018. Additionally, an unmanned aerial vehicle three-dimensional photogrammetric survey was carried out in 2016. Analyses of the three-dimensional digital models of the main scarp made it possible to carry out several exhaustive multi-temporal investigations and to derive a detailed three-dimensional change detection scheme for it. The results showed an active geomorphological evolution of the rock scarp area due to frequent rockfalls and topples (of the order of a few m3), with significant local volume changes (a few thousand m3/year) and with potential implications for the long-term evolution of the entire slope. [ABSTRACT FROM AUTHOR]

This work deals with the landslides affecting the area surrounding the village of San Martino sulla Marrucina and involving the neighboring municipalities of Casacanditella and Filetto. The geological and geomorphological settings of this area are being discussed. The enclosed maps have been realized following a multidisciplinary approach, based on morphometric, geological, and geomorphological analyses and supported by air-photo interpretation, dendrochronology, and satellite SAR interferometry (InSAR). The map is organized in four sections: orography (on the upper part), geological map (on the upper right part), main geomorphological map (in the central left part, 1:7,500 scale), and multitemporal analysis (in the lower part). The aforementioned multi-temporal assessment of landslides was performed according to the geomorphological evidence-based criteria and the past ground displacement measurements were obtained by dendrochronology and InSAR. The aim of the study is to understand the evolution in time and space of this landslide area, focusing on the corresponding kinematics. [ABSTRACT FROM AUTHOR]

Abstract: The results of a study on gravitational induced lateral spreading phenomena are here reported. The lateral spreading processes are widely represented in the Italian Apennines due to the widespread overlapping of stiff rock masses on more ductile ones. The stress–strain evolution of these processes was investigated by combining an analogical and a numerical modelling approach. The analogue modelling reproduced the evolution of a carbonate ridge thrust over a clayey flysch with reference to the case-study of Mt. Roccatagliata–Mt. Sant'Angelo ridge. The rock mass juxtaposition was reproduced in a laboratory experiment by overlapping a brittle concrete on a viscous ductile material; these materials were selected with rheological properties, physically scaled with respect to the natural rock mass prototypes. The spreading phenomenon was modelled by opening horizontal panels in sequential stages and monitoring the resulting stresses within the ductile material during the experiment. A stress–strain modelling was also performed by an FDM numerical solution; this modelling replied the laboratory experiment by testing the use of different rheological constitutive laws. The resulting stresses and morphological evolutions are comparable with the analogical laboratory experiment only if a time-dependent rheological behaviour is assumed for the ductile material. The results show that lateral spreading processes can be properly investigated by combining analogue and numerical modelling techniques which take into account the viscous-plastic behaviour of the used materials. [Copyright &y& Elsevier]

This research illustrates the case of a deep-seated gravitational slope deformation (DSGSD) affecting a folded structure that developed during Miocene tectonics in the Northern Apennines of Italy, deforming a heterogeneous turbiditic sequence characterised by pelitic-marly and arenaceous intervals. The investigated area includes the headwater portion of the Bidente River basin that has experienced intensive valley incision during the late Quaternary and the sizeable Poggio Baldi landslide with failure episodes in 1914 and 2010. The aim of this work was to unravel the local morphostructural setting determined by the interplay between the active DSGSD, inherited fold geometry, and fluvial dynamics. Dip data collection and structural analysis were used to reconstruct the fold geometry. A complex type of fault-propagation fold was outlined, with later breakthrough thrusts causing the backlimb rotation. Gravity-driven geomorphological features were inventoried and displayed on two geological cross-sections together with Geological Strength Index measurements, while their distribution was analysed to conceive a conceptual model for the development of the DSGSD. Fold setting and lithological anisotropies were considered as the predisposing factors of the gravitational slope deformation, whereas the multi-step entrenchment of the Bidente River valley, testified by the presence of the remnants of at least three generations of fluvial erosional terraces, was considered as the main cause of its initiation. Finally, the reconstruction of the original slope topography in the Poggio Baldi area and the results of structural analysis performed in the landslide detachment zone through remote sensing techniques allowed for the estimation of the size of the wedge-shaped rock block which detached in 1914, an event that occurred in the wider frame of the DSGSD. • A Neogene fold structure shows evidence of Quaternary gravitational deformation. • Structural and lithological features influenced evolution of DSGSD. • Quaternary fluvial erosion in the Bidente River valley drove slope unconfinement. • The Poggio Baldi landslide occurred in a slope-scale gravitational deformation. [ABSTRACT FROM AUTHOR]