Evolución petrológica y geoquímica de rodingitas durante la subducción y deshidratación de rocas mantélicas (Complejo Nevado-Filábride, SE de España)implicaciones para el funcionamiento de una zona de subducción

Résumé

This thesis highlights the origin and the metamorphic and geochemical evolution of metarodingites from Cerro del Almirez (Betic Cordillera). The three types of metarodingites identified in the massif represent the successive transformations of these rocks from their formation on the ocean floor to their subduction to "sub-arc" conditions (16-19 kbar - 660-684 °C). During this evolution, metarodingites underwent changes in pressure and temperature, gradients of chemical potentials, redox transformations and interaction with fluids produced by dehydration of enclosing serpentinites. The associated geochemical variations show that during subduction metarodingites concentrate Ca, Fe3+, Sr, Pb and Ba and can contribute to the oxidation of the deep mantle and the origin of deep reservoirs rich in Ca. The fluids released from metarodingites, rich in Ca, Re, Pt and Pd, may contribute to the refertilization of the "sub-arc" mantle and the generation of deposits of economic interest.