Sea level changes and tectonic mobility: Precise measurements in three coastlines of Italy considered stable during the last 125 ky

Fast uplift or subsidence rates, related to incense tectonic-seismic activity, affect the Mediterranean coasts, especially in its eastern sector and Calabria, whereas other areas appear relatively stable. Along the southern Italian coast, the most widely distributed and therefore useful reference datum is the paleo sea level related to isotopic substage 5e (125 ky). In the present study, this marker (inner edge of marine terrace or notch) has been safely identified along three sectors of the Italian coast generally considered tectonically stable: eastern Sardinia, southern Latium and northwestern Sicily. In Latium the top of the Eutyrrhenian transgression was found to vary between -5 and +9.8 m a.s.l. along a 100 km long coast. A well carved Eutyrrhenian notch can be followed for ca. 35 km along the coast of Orosei in Sardinia, gradually varying in elevation between 7.7 and 10.5 m a.s.l., thus indicating a regional tilt. In Sicily, the inner edges of the Eutyrrhenian terrace and marine notches are at elevations between 8 and 13.9 m a.s.l.. In all these areas the stage 5e marker has shown a significant local mobility demonstrating its utility for detailing either areal or linear tectonic activity during the last 125 ky along the Tyrrhenian Sea coasts. (C) 1999 Elsevier Science Ltd. All rights reserved.