Mineral host inclusion systems are a window into the solid-state rheology of the Earth

Natural processes such as earthquakes, volcanism and orogenesis are controlled by plate tectonics which, in turn, depend on how rocks and minerals, the building blocks of Solid Earth, deform under different environmental conditions. The rheology of rock-forming minerals is therefore the key for understanding the geodynamics of our planet. Our present knowledge of mineral rheology mainly comes from laboratory experiments and theoretical models that are based on synthetic systems with simplified chemistry. However mineral properties strongly depend on structural defects and impurities. Therefore, the interpretation of natural chemically complex systems requires uncertain extrapolations. Mineral inclusions are macroscopic defects with respect to their host, so studying in situ their effects on the rheology of their host minerals opens a promising prospect for a better understanding of the rheology of mineral assemblages and thus the dynamics of our planet.The study of mineral host-inclusion systems by Raman spectroscopy at non-ambient conditions is an effective method to probe in situ deformational processes in the Earth's interior