Sorano tuff quarries, Sorano, Grosseto Province, Tuscany, Italyi

Regional Level Types
Sorano tuff quarries	Group of Quarries
Sorano	Commune
Grosseto Province	Province
Tuscany	Region
Italy	Country

Quarries of yellow zeolitic tuff near Sorano at Pian di Rena [Piandirena and Campimaglia quarries] (see coordinates) and also at San Valentino-Poggio Corto, Poggio Ceccarello, Castell’Ottieri-Poggio Puriballo, Podere Ronchetto, Podere Riparella, San Giovanni delle Contee, and Podere dell'Aiaccia.

The yellow tuff, described as "Tufo Giallo Litoide" (Nappi, 1969), "D Ignimbrite" (Sparks, 1975) or "Sorano formation" (Vezzoli et al., 1987), is a very fine-grained trachytic ignimbrite attaining a few tens of meters in thickness, emplaced during Plinian eruptions in the Latera volcanic complex. This formation locally contain several thin beds composed of pumice with reverse size-grading. The Sorano formation also gave rise to deep channels carved into the underlying formations. The small pumices enclosed in the ash-sized matrix are rounded and contain spherical vesicles. From a volcanological point of view, this formation is related to an emplacement mechanism involving water-magma interaction, as it is classified as pyroclastic flow, characterized by an abundant fluid phase and emplacement temperatures of a few hundred degrees. Furthermore, it commonly was extensively zeolitized, leading to crystallization of predominant chabazite by the transformation of trachytic and/or phonolitic primary glass. Authigenic chabazite from Pian di Rena is characterized by a Si/Al ratio of 2.19, a K/Ca ratio of 1.00, and a Na/K ratio of 0.14 (Cappelletti et al., 1999).

Large cavities and fractures in yellow tuff are lined with amber-coloured calcite, whose crystals can sometimes attain 8 cm in length. This calcite typically fluoresces yellow under UV light (Stoppani & Curti, 1982).

Other Regions, Features and Areas containing this locality

References