La frana di Maierato (Calabria, Italia meridionale) del febbraio 2010: caratteristiche geomorfologiche ed evoluzione

The Maierato Landslide (Calabria, South Italy) of february 2010: geomorphological characteristics and evolution. The landslide triggered on February 15, 2010, by intense and long-lasting rainfalls, occurred on the left slope of the Scotrapiti torrent, close to Maierato city, Calabria, South Italy. The landslide involved Upper Miocene to Pleistocene sedimentary terranes consisting of (bottom to top) marine clay, evaporitic chalk with clay seams, silty clay, silt, and continental sand and conglomerate. The landslide destroyed a few not inhabited country houses, several hundred meters of main roads, and ca 25 ha of olive grooves and cultivated land. It formed a small lake by damming the Scotrapiti torrent. The movement is a complex one, consisting of compound earth slide and earth fl ow. The overall length is ca 1,4 km; width ca 500 m; the volume ca 5.106 m3. Geological and geomorphologic fi eld studies, aerial photos interpretation and fi lm shots taken during the paroxysmal phase of the event, allowed us to reconstruct the geometry and dynamics of the landslide. The movement consisted in the reactivation and partial retrogressive extension of an old phenomenon. Geological setting and tectonics played a key role in the peculiar dynamics of the landslide, in which a widespread liquefaction of buried chalk developed dramatically, causing the movement of rafted units of clay and silt at a rate of ca 5 m.s-1 and the formation of extrusion cones and lobes of chalk among units and along the landslide fl anks.