Research Article

CPO2Hill: An Efficient Parametrisation to Infer Anisotropic Viscous Behaviour Directly from Olivine Texture Parameters

Volume 1, Issue 1, Published on 2026-06-15
DOI: https://doi.org/10.5070/F3.49008

Abstract:

Anisotropic viscosity is likely prevalent within the upper mantle, but is usually disregarded in geodynamics models. On a crystal scale, olivine’s intrinsic properties are such that dislocation creep occurs over an order of magnitude more easily along olivine’s [100] symmetry axis than along its [001] axis. However, deforming olivine aggregates generate crystallographic preferred orientations (CPO) with their own macroscopically effective anisotropic viscosities that have proven difficult to estimate from the microscopic anisotropies of individual olivine crystals. Here we present a simple method to derive anisotropic viscosity parameters directly from the CPO mean orientation tensors. To calibrate the method, we created a large database of textures likely to occur in geodynamic simulations. We tested our method within numerical simulations of simple shear with both constant and varying shear directions. Finally, we integrated our method into the geodynamic code ASPECT, where it can be used to explore the geodynamic importance of anisotropic viscosity.

Cite this article as:

Király, Á., Wang, Y., Conrad, C. P, Hansen, L. N, & Mather, B. (2026). CPO2Hill: An Efficient Parametrisation to Infer Anisotropic Viscous Behaviour Directly from Olivine Texture Parameters. Geodynamica, 1(1). http://dx.doi.org/10.5070/F3.49008