Pliocene –Pleistocene geomorphological evolution of the Adriatic side of Central Italy

Abstract

This work is a significant contribution to knowledge of the Quaternary and pre-Quaternary morphogenesis of a wide sector of central Italy, from the Apennine chain to the Adriatic Sea. The goal is achieved through a careful analysis and interpretation of stratigraphic and tectonic data relating to marine and continental sediments and, mostly, through the study of relict limbs of ancient landscapes (erosional surfaces shaped by prevailing planation processes). The most important scientific datum is the definition of the time span in which the modelling of the oldest morphological element (the "summit relict surface") occurred: it started during Messinian in the westernmost portion and after a significant phase during middle-late Pliocene, ended in the early Pleistocene. During the middle and late Pleistocene, the rapid tectonic uplift of the area and the climate fluctuations favoured the deepening of the hydrographic network and the genesis of three orders of fluvial terraces, thus completing the fundamental features of the landscape. The subsequent Holocene evolution reshaped the minor elements, but not the basic ones.

Geomorphological evidence of debris flows and landslides in the Pescara del Tronto area (Sibillini Mts, Marche Region, Central Italy)

“…folds and thrusts due to the emplacement of the Apennine chain) and Quaternary extensional faults (due to post-orogenic collapse), with (N)NW-(S)SE trending, associated to intramontane basins and present-day seismicity (Calamita & Pizzi, 1994;Pizzi et al, 2017;Tavernelli et al, 2004). The geomorphological setting is the result of a complex cyclic evolution that occurred in succeeding stages with the dominance either of morphostructural factors, linked to the conflicting tectonic activity and regional uplift, or morphosculptural factors, linked to drainage network linear down-cutting and slope gravity processes (Cello et al, 1997;Farabollini et al, 1995;Gentili et al, 2017;Materazzi et al, 2010;Tondi & Cello, 2003). These factors refer to different morphogenetic processes, that have shaped and still model the area, mainly linked to litho-structural features of the bedrock; Plio-Quaternary extensive tectonics and uplifting, as testified by the strong seismicity of the area; Quaternary climatic changes and recent anthropic activity (agriculture, urbanization, water regulation, extraction of aggregates from the riverbeds, etc.…”

Landslide Hazard Assessment in a Monoclinal Setting (Central Italy): Numerical vs. Geomorphological Approach

“…This sector corresponds to a vast sedimentary basin where, starting from the early Pliocene, thick levels of sandstones and conglomerates alternated with peliticarenaceous levels are deposited in transgression over a Miocene (Messinian) turbidite bedrock, mainly consisting of alternating arenaceous-pelitic and pelitic-arenaceous levels (Laga formation) [36,37] (Figure 1b,c). The contact between post-and pre-transgressive sediments is marked by an erosion surface approximately parallel to the Miocene levels [32,38]. The area is particularly characterized by the presence of weak levels and ductile deformation zones, corresponding to the weathered levels of the pre-transgressive clayey basement.…”

“…The present work compares the results of a landslide analysis carried out in a sample area using both geomorphological and numerical approaches. The area chosen for the analysis is located in a high hilly sector of the Adriatic side of the Central Apennines (Italy), characterized by the presence of monoclinal reliefs and typical cuesta morphologies, formed by differential tectonic movements in a recent uplift area [31,32]. Despite the relative simplicity of the geological model, these contexts can generate complex mass movements, both for characteristics (type of movement) and size (extension and depth of the failure zone) and kinematics (velocity and return time) and consequently represent high hazard conditions in the presence of built-up areas and/or infrastructures.…”

Tectonically Induced Deep-Seated Gravitational Slope Deformations and Large Landslides in the Central Adriatic Coastal Belt (Southern Marche-Abruzzi, Italy)

“…Escarpments and trenches parallel to the shore line and up to more than 1 km in length, indicating the presence of deep reaching rupture surfaces, interpretable as listric faults induced by the ongoing tectonic deformation of the coastal ridge fronts, are common features along the Central Adriatic coast. They are constantly associated with the large coastal landslides but also appear in sectors not affected by these phenomena [28,33].…”