Late Quaternary sea-level changes along the Tyrrhenian coast near Orbetello (Tuscany, central Italy): palaeoenvironmental reconstruction using ostracods

A multidisciplinary study has been carried out on a 51 m long core, drilled on coastal lowlands near the Albegna River (Tuscany, Central Italy). Both sedimentological and faunal analyses (ostracods and molluscs) indicate a co astal lagoon environment repeatedly influenced both by the rising Holocene sea and the Albegna River alluvial inflow. delta(13)C, delta(18)O, Mg/Ca, S r/Ca and Sr-87/Sr-86 analyses were performed on Cyprideis torosa shells in order to detail the influence of Albegna River freshwater on the coastal la goon water The analytical data illustrate the difficulties of using geochem ical proxies in marginal marine settings. Four radiocarbon dates provide a chronostratigraphy for the early Holocene part of the core. The data are us ed to reconstruct Late Pleistocene to early Holocene palaeoenvironments alo ng this part of the coast and show the development of freshwater environmen ts followed by a coastal brackish lagoon formed in response to the initial Holocene rapid rise in relative sea level. An attempt is made to relate sed iments and age data from the core to the relative sea-level, curve for the Tyrrhenian Sea. (C) 1999 Elsevier Science B.V. All rights reserved.