IL MAGMATISMO NEOGENICO-QUATERNARIO DELL'AREA TOSCO-LAZIALE-UMBRA: IMPLICAZIONI SUI MODELLI DI EVOLUZIONE GEODINAMICA DELL'APPENNINO SETTENTRIONALE

Abstract

A review of the available petrological, geochemical and geochronological data on the magmatic rocks of the Tuscan­Latium- Umbria region has allowed to recognize a simple petrogenetic scheme that has been used to put important con­straints on the structure of the upper mantle below Centrai Italy and consequently on the geodynamic evolution of the region. The magmatism took piace in four phases separated in space and time which become progressively younger from west to east : Phase I, -14 Ma (Sisco-Corsica); Phase II, 7.3-6.0 Ma (Mt. Capanne, Montecristo, Vercelli, Capraia I); Phase III, 5.1-2.2 Ma (Porto Azzurro, Giglio, Campiglia, Ga­vorrano, Castel Di Pietra, Monteverdi, San Vincenzo, Orcia­tico, Montecatini Val di Cecina, Capraia II, Roccastrada e Distretto tolfetano); Phase IV, 1.3-0.1 Ma (Radicofani, Cimi­ni, Torre Alfina, Amiata, as well as the Northwestern Roman Magmatic Province). [...]