A case study of zeolitization process: “Tufo Rosso a Scorie Nere” (Vico volcano, Italy): inferences for a general model

Abstract. This paper focuses on the authigenic mineralization processes acting “Tufo Rosso a Scorie Nere” (TRS), i.e. one of main pyroclastic units Vico stratovolcano (Latium, Italy). The deposits appear in general massive and made “black vitreous vesiculated juvenile scoriae”, immersed an ashy matrix lithified after zeolitization processes. minerals are chabazite phillipsite, zeolitic content is locally variable, reaching 68 % wt. Zeolites grow replacing both amorphous fraction pre-existing phases, occurring inside scoriae. Concerning scoriae, moves from rim to core scoriaceous fragment as function (a) temperature fluids (b) permeability (primary or secondary). Composition parental fresh glass that zeolitized rocks compatible with trachyte chemistry, lightly undersaturated SiO2, alteration modified rock chemical features. genesis ascribed “geoautoclave-like system”, zeolites display Si/Al ratio similar glasses. TRS presents promising mineralogical characteristics supplementary cementitious material production mixed cements.