Selected Type-Localities of Potassic Igneous Rocks from the Five Tectonic Settings

Abstract

The volcanic rocks of Central Italy (Fig. 4.1) are divided into three magmatic provinces (van Bergen et al. 1983):

• In the north, predominantly acid igneous rocks of Amiata, Roccastrada, San Vincenzo, and Elba represent the Tuscan Province.

• In Central Italy, along the western side of the Apennine Fold Belt, the highly potassic volcanic centres of Vulsini, Vico, Sabatini and Alban Hills form the Roman Province (see also Holm et al. 1982; Rogers et al. 1985).

• Potassic volcanoes such as Roccamonfina and Vesuvius, and the lavas of the Phlegrean Fields and Vulture form the Campanian Province in the south (van Bergen et al. 1983; D’ Antonio and Di Girolamo 1994). The Pliocene-Quaternary volcanic rocks from the Roman Province, Italy, are considered to be typical examples of orogenic ultrapotassic rocks as defined by Foley et al. (1987).