Decoding Late Quaternary faulting through marine terraces and MIS 5.5 tilted tidal notches: Insights from central Mediterranean Sea (NW Sicily, Italy)

Abstract

This study investigates the recent tectonic evolution of coastal landscapes, focusing on integrating fossil tidal notches and fossil marine terraces as tools for coastal tectonic studies in the Capo Rama promontory (central Mediterranean, southern Italy, NW Sicily). These geomorphological features are crucial for understanding the tectonic forcings that shape coastal landscapes (e.g. active faulting or regional uplift), especially in the context of the high resolution topographic and morphometric data available today. This research addresses a significant gap in the current understanding of the combined use of these markers to study the evolution of the coastal landscape and its tectonic drivers. The aim is to elucidate the interplay between coastal geomorphology and tectonics in areas with elusive tectonic activity (i.e., regions deforming at a rate lesser than 1 mm/yr), hosting previously undetected seismogenic sources and, for that reason, assumed as having low seismic hazard. Employing a multidisciplinary approach, the study integrates surveys conducted along the emerged and submerged coastline with analytic/statistical morphometric analyses and fault modelling. This methodology offers a comprehensive view of the elevation and distribution of MIS 5.5 littoral deposits and coastal geomorphological markers such as marine terrace inner edges and tidal notches. Key findings reveal substantial elevation differences in these markers, varying between +34 and +1.9 m above sea level along a north-south transect, highlighting an active seaward tilting in the study area. Such tilting is related to the Quaternary deformation of a previously unknown buried fault crossing the study area. Achieved outcomes allowed exploring the integration of tidal notches and marine terraces' inner edges as geomorphological markers for coastal tectonic analyses. Moreover, this study lays foundations for future research, enabling a more detailed understanding of the hypothesized buried fault, and its contributions to the understanding of the active faulting processes in the southern Tyrrhenian region.