Mechanical behaviour of iron containing ferropericlase at high pressures and temperatures

Ferropericlase (fPc) is the second most abundant mineral in the Earth’s lower mantle after Bridgmanite (Bgm). Thus, the mechanical behaviour of fPc has important consequences for the rheology of the lower mantle, and by consequence, the evolution of the Earth through convection of materials and heat through the mantle. Much work as been done on the Mg pure end-member of fPc as well as fPc-Bgm aggregates. The effect of iron on fPc mechanical response under pressure was studied at 300 MPa and compression textures were measured using the diamond anvil cell. Flow laws, i.e. the relationship between applied stress and the resulting strain rates, were never measured above 300 MPa in iron-bearing fPC. This is a critical gap as iron content of fPc has been shown to modify its physical properties significantly. The lack of understanding of the effect of Fe on the mechanical properties of fPc under pressure is a true knowledge gap that we wish to address in this proposal.