Vene a zeoliti in zona di faglia: i casi delle linee Merano-Mules e Pusteria (Alto Adige).

The focus of this thesis is to analyze the devolopment of brittle deformation and fluid-rock interaction within fault zones interested by sin-deformational intrusions. The study areas are localized along the Pustertal (Mules and Chienes sites) and Meran-Mauls Lines (Passo di Pennes site) belonging to the Periadriatic Lineament. The two lines have had a long common deformation history and are both characterized by the intrusion of the Tonalitic Lamella (Oligocene) during their activity. Hence the deformation processes developed within the two fault zones can be compared. The occurrence of more or less pervasive veins in different sector of the shear zones (core and damage zones), makes them perfect cases for studying fluid-rock interactions. Different analytical techniques including remote sensing, geological-structural survey, optical microscope analysis, XRPD (X-ray Powder Diffraction), SEM (Scanning Electron Microscope) and Raman spettroscopy have been used to evaluate these processes. The results have allowed to conclude that the Pustertal Line and Meran-Mauls Line acted together until the activation of Brenner detachment (lowest Miocene) and have been affected by aboundant fluids circulation. Within the damage zones fluids were injected along veins consistently oriented with respect to the regional stress field, whereas the core zone seems to record conditions of fluid overpressure (caotic veining) together with cataclastic flow. The last cataclastic flow event seems to affect only the Pusteria line and is likely associated to a lower fluid circulation (veins rare or absent). The different mineralogical associations within the veins (e.g. zoisite+prehnite+quarzo, prehnite+laumontite, chabasite) suggest a gradual fluid temperatures decrease during fault evolution.