Pattern Formation in Rocks

This commentary concerns a two‐part paper by Regenauer‐Lieb et al. (2026a, 2026b) on pattern formation in deforming porous rocks. The theory developed in part I ( https://doi.org/10.1029/2025GC012710 ) uses the general idea of Turing's reaction‐diffusion model of morphogenesis based on interactions between two types of diffusible chemical species (morphogens). One species is an autocatalytic reactant and the other a more rapidly diffusing reaction product acting, respectively, as “activator” and “inhibitor” in the development of biological patterns. The new theory incorporates stress and cross‐diffusion effects, the latter accounting for the fact that a specific flux is affected by all forces in the system (chemical gradients, temperature gradient etc.). For rocks, deformation and fluid pressure within the pores act as “activator” and “inhibitor,” with their roles depending on the state of deformation and permeability. In part II ( https://doi.org/10.1029/2025GC012717 ) the authors discuss applications of their theory to explain the development of a variety of seemingly unrelated features in rocks. For the specific case of the banded iron formations, this theory does not, however, provide a stand‐alone explanation for their origin but could be used to analyze stress effects on the banding that originated primarily from chemical processes. Finally, I offer suggestions for some future research directions that should be of interest to the Earth and Planetary Science communities.