Genesi ed evoluzione di piane costiere del Mediterraneo: esempi di piccole piane in Liguria

Origin and evolution of Mediterranean coastal plains: some examples of Liguria

Abstract

The Mediteranean coastal plains are very significant geological areas both for research and applications. In fact, they keep fundamental information about different phases of the evolution of wide parts of the continental margin moreover they usually shelter the most important urban centers and economic activities. Basing on these presuppositions, the authors deal with problems concerning genesis and evolution of coastal plains in the Western Mediterranean Sea that, being constituted by young basins, is characterized by a rapid evolution of his margins and suggest a schematization of phenomena generating these plains, based on geodynamic of disjunctive processes. Three genetic models for coastal plains are theoretically distinguished on the base of examples taken from Tyrrhenian Sea and Ligurian-Provencal Basin. These general patterns are applied to the analysis of the genetic and evolutionary characteristics of the little Ligurian plains. In this connection a knowledge about structural characteristics of the Ligurian Sea is necessary, distinguishing the Thyrrenian margin from the “Alpine” margin. The plains in Eastern Liguria, having a recent geological history, show a not completely evolved stadium, while the plains in Western Liguria, because of a complex Neotectonics, show more developed characteristics. As examples of the «Tyrrhenian» Liguria, the Versilia plain and the Levanto plain are proposed, while for the «Alpine » Liguria the Albenga plain, whose characteristics are common to other plains, is shown. Starting from the Plio-quaternary evolution of these plains an evolutional model is suggested for Western Ligurian Coast.