Natural Laboratories for Field Observation About Genesis and Landscape Effects of Palaeo-Earthquakes: a Proposal for the Rocca Busambra and Monte Barracù Geosites (West Sicily)

Abstract

Earthquakes are phenomena that are still being learned by the scientific community, and poorly known, especially as regards the prevention, by the population. Having a more complete knowledge is a basic step in understanding the vastness and intensity of the destructive phenomenon that involves a great amount of people. The recent earthquakes occurred in Central Italy (L’Aquila and Amatrice earthquakes) are examples that demonstrate the importance of having knowledge about these phenomena to contrast their destructive effects. We present a geological field trip to recognise causes and landscape effects of palaeo-earthquakes recorded in the Mesozoic rock successions outcropping in Sicily. The isolated carbonate reliefs of Rocca Busambra and Monte Barracu (Sicani Mountains) are spectacular sites of a passive continental margin where synsedimentary tectonic features—as palaeo-faults, neptunian dykes, morphostructural scarps, submarine landslide and soft sedimentary deformation structures—document earthquake causes and effects. Field evidence show in detail as the several palaeo-faults mapped in the Rocca Busambra stepped margin triggered the soft-sediment deformation structures recorded in the coeval deep-water rock succession of the Monte Barracu. In this view, the proposed field trip can represent a powerful tool to enhance the naturalistic and geological importance of the study areas by establishing geosites and protected areas for a proper fruition of geological-natural heritage and/or for geoconservation. Thus, through the proposed field trip it is possible to observe palaeo-earthquakes activity and landscape products, having an educational training purpose also for public administrators, whose rapid and skilled action is necessary for the prevention and reduction of the geohazard.