Analisi termocronologica e microstrutturale lungo il nuovo tunnel del Brennero.

The study carried out during this thesis concerns a series of thermochronometric data analyses and micro-structural microscope observations on seven samples coming from the Brenner Basis tunnel, which aimes at connecting Italy with Austria. The samples were taken across the Pusteria Fault, one of the major fault of the Alps. The sections we classified and examined comprise granite rocks belonging to the Brixen Granite and post-orogenic intrusive igneous rocks belonging to the Tonalitic Lamella. The results show that the first ones are essentially undeformed while the second ones, in particular the nearest sample to the Pusteria Fault, exhibit a strong mylonitic foliation with clear cataclastic layers. On these samples, we conducted thermochronometric analyses by using the (U-Th)/He thermochronometer to date apatites; dates appear to be deeply influenced by the presence of hot circulating fluids which caused a reset of the He system.