Studio sull'orientazione preferenziale degli assi c del reticolo cristallino del quarzo in una milonite granulitica della Calabria. = Study of the quartz c-axis preferred orientation in a granulite facies mylonite of the Calabria basament.

This study will focus on a granulite mylonite from the Amaroni Shear Zone in the Serre Massif within the Calabria-Peloritani-terrain arc. The mylonite appears to be structurally and geometrically linked to the mean Alpine thrust contact: the Curinga-Girifalco Line, which separates the basement units from those that underwent an Alpine overprint. The researcher’s aim is to identify the mylonitic shear zone. In particular, to understand if the mylonite was subject to high temperature conditions during granulite facies metamorphism in the Varisican orogeny, or whether it formed at lower temperatures associated with amphibolite to greenschist facies metamorphism during the Alpine orogeny.These uncertainties regarding emplacement conditions can be deduced quickly and effectively by studying the rock’s microstructures, specifically the crystallographic preferred orientation of the minerals (CPO). The analysis of the quartz microlattice structure, using the EBSD technique and analysis of kinematic indicators, will allow us to deduce the correct P-T-t conditions operating during the mylonite’s formation. From the experimental data, we assert that the mylonite formed during high temperature conditions pertaining to granulite facies metamorphism. The conditions necessary for the development and evolution of a high grade metamorphic environment were active during the extension and isothermal uplift phase, which is characteristic of the Calabria-Peloritani-terrain arc earlier than 300 Ma, but not after 252 Ma. After this time, it is known that temperatures were below the conditions necessary for granulite facies metamorphism.