Progetto PSR (2025) Linea 8-Sottomisura B- Dott. Theo Auguste BIGET (Tutor: Prof. Cannaò Enrico) - Missione a Parigi

and Magnesium are major components of the Earth's lithosphere and mantle. The study of their stable isotopes has grown rapidly, offering insights into redox conditions (Fe), carbonation/decarbonation (Mg), partial melting, and fractional crystallization processes. These isotope systematics are usually applied to whole-rock samples or mineral separates, achieving very high analytical precision. However, whole-rock analyses may also reflect undesired hybrid or mixed signatures, due to superimposed effects such as partial re-equilibration or recrystallization. The advent of in situ isotope analyses enables grain-scale studies, providing access to intracrystalline diffusion, crystal growth kinetics, and fluid–rock interaction. Despite its potential, this method remains underused and unsupported in Italy. This project addresses this gap by developing in situ Mg and Fe isotope protocols at the Geochemistry Laboratory of UNIMI. The first phase aims at developing Mg isotope in-situ analyses. This phase is already underway and will serve as a model for the subsequent development of Fe protocols. The second step aims at developing protocols for in situ Fe isotope analysis and to further characterize international Fe standards. To support this work, I will conduct a four-week research visit to the Institut de Physique du Globe de Paris (IPGP), where advanced Fe isotope protocols are already in use. Under the supervision of Dr. Baptiste Debret (CNRS–IPGP), I will be trained in solution-based Fe isotope analysis, instrument tuning, and will gain hands-on experience with an established methodology. The knowledge acquired during this visit will then be transferred and adapted to the instrumentation available at UNIMI. Based on this experience, the final goal is to develop in situ Fe isotope analysis at UNIMI. The successful implementation of this research will establish UNIMI as a leading national and international center for Fe and Mg isotope geochemistry.