| Abstract: | In the Bolsena volcanic district (Vulcani Vulsini) near the little town of Pitigliano, at the border between Latium and Tuscany, a lava sheet showing quite peculiar geological features has been examined in all its macro and microscopic aspects. Such volcanic deposit is an interesting example of the uncommon products originated by the Quaternary alkaline mediterranean volcanism. The Pitigliano sheet was erupted from the NW section of the Latera caldera, and covered an area of about 6×12 km mantaining an extremely small thickness (from a feet to few yards). This sheet is normally made of a leucitic lava entirely so densely microvesiculated as to be better called pumice. At the flanks, and expecially at the front of the sheet, the rock gets a piperno-like or welded tuff aspect. The different facies and the transitions between them have been carefully studied and interpreted. |
