28 July 2026 - New publication in Progress in Earth and Planetary Science

An alternative framework for lower mantle rheology

Following recent discussions on the rheology of the Earth's lower mantle, understanding the physical mechanisms controlling deformation under extreme pressure–temperature conditions remains one of the central challenges in mineral physics.

In this context, the review "Rheology of the lower mantle: an alternative review" has been accepted for publication in Progress in Earth and Planetary Science.

Rather than revisiting the debate from a phenomenological standpoint, the article retraces the development of a mineral-physics framework in which constitutive laws emerge progressively from elementary deformation mechanisms. Starting from point defects, dislocations, diffusion and grain-boundary processes, it reviews how advances in first-principles calculations, atomistic simulations, dislocation dynamics and polycrystal modelling have progressively established quantitative links between atomic-scale processes and the rheology of deep-mantle minerals.

Although particular attention is devoted to ferropericlase and bridgmanite—whose relative mechanical behaviour remains central to current discussions—the review also examines the broader spectrum of lower-mantle phases, including periclase, high-pressure polymorphs of olivine and post-perovskite, together with the experimental and theoretical approaches used to investigate their deformation.

Beyond providing an alternative synthesis of the field, the review seeks to clarify the conceptual continuity of developments that have progressively shaped mineral-physics-based descriptions of lower mantle rheology.

More broadly, it advocates a mechanism-based strategy in which constitutive laws emerge from the progressive integration of physical processes across scales, rather than from the extrapolation of laboratory flow laws beyond their domain of validation.

To learn more:

P. Cordier, J. Van Orman, P. Carrez (2026) Rheology of the lower mantle: an alternative review. Progress in Earth and Planetary Science, 13, 45. https://doi.org/10.1186/s40645-026-00835-6