Chrono-stratigraphy of Italian coastal dunes: implications for Holocene relative sea-level change and coastal progradation

Coastal dune systems are fundamental transitional geomorphological features that function not only as natural barriers for coastal protection but also as valuable geo-archives capable of recording the evolutionary dynamics of coastal landscapes. Along the Italian coasts, the formation and stabilization of these systems during the Holocene and historical periods have been shaped by a complex interplay between post-glacial sea-level rise, variability in fluvial sediment supply, and increasingly significant anthropogenic impacts. This contribution provides a systematic review of dated coastal dune systems across the Italian peninsula and its major islands. The primary objective is to synthesize current knowledge and establish a consistent chrono-stratigraphic framework. By integrating geomorphological data, radiometric dating (OSL and ¹⁴C), geoarchaeological evidence, and historical cartography, this study analyzes the spatial and temporal distribution of dune ridges. This integrated approach allows for the identification of synchronous phases of stabilization and progradation at a regional scale, offering a comprehensive perspective on how Mediterranean shorelines have responded to Late Quaternary forcing factors. A key focus of this ongoing research involves utilizing these dated dune sequences as high-resolution proxies for quantifying coastal progradation rates. By correlating the spatial position of dune bodies with their absolute ages, it is possible to derive estimates of shoreline advancement rates across diverse physiographic settings, such as deltaic lobes, open coastal plains, and embayed sectors. This methodology enables a distinction between periods of rapid progradation often linked to high sediment supply or sea-level stabilization—and phases of coastal stability or erosion. In conclusion, this review demonstrates that the integrated study of Italian coastal dunes is not only essential for paleogeographic reconstruction but also provides vital quantitative parameters (progradation rates) for understanding coastal resilience. Such data are crucial for calibrating evolutionary models in response to contemporary sea-level rise and decreasing sediment delivery, aligning with the core themes of proxy identification and process understanding in past and present interglacials.