Map arrangement

The area represented by the map includes the group of north-western islands of the Pontine archipelago (Ponza, Zannone and Palmarola), a marginal part of the Pontine plain (between the lake of Fogliano and the lake of Caprolace) and the continental platform section in front of it. The Pontine archipelago is actually composed of five major islands located offshore on the Tyrrhenian coast of the Lazio and Campania regions, at a latitudine between 40° and 41°.  However, due to both geological considerations and geographical purposes, it can be divided into two parts: a south-eastern group composed of Ventotene and Santo Stefano islands (located south of Gaeta) and a north-western group composed of islands contained in Sheet no. 413 (located 30 km south of the Circeo promontory). The previous geological map dates back to 1960 and is represented by Sheet no. 170 “Terracina”, of the Geological Map of Italy on a scale of 1:100,000.