Land subsidence induced by slow gravitational deformations and by digging of rock-salt in S. Leonardo territory (Lungro town – Calabria region – Southern Italy)

In the hill crest, near Lungro town (Calabria Region – Southern Italy), between the S. Leonardo and S. Angelo localities, at an average elevation of 525m a.s.l., a land subsidence phenomenon is active; it is due to the concomitance of several factors, ranging from a DSGSD arc-shaped rupture, of a total length of about 2,5km, to the digging of a rock-salt mine at an el. of about 400m a.s.l. and to the chemical dissolution induced by the underground water, as many springs show. The subsidence and big landslides involve recent buildings and roads. Data at present available furnish lowering of about ten centimeters in the last 5-10 years. The subsident area involves Pliocene conglomeratic formation transgressive on Upper Miocene saliferous clays resting in their turn on the underlying scaly argillites of the Cretaceous Chaotic Complex. Keywords: land subsidence; DSGSDs and big landslides; rock-salt digging; Pleistocene transcurrent fault.