Anticrack model for pressure solution surfaces

TLDR: In this article, the authors propose that discrete solution surfaces originate at stress concentrations and propagate through rock as anticracks, where the anticrack walls move toward each other; stress and displacement fields are identical to those for the conventional opening crack, but with a change of sign.

Abstract: We propose that discrete solution surfaces originate at stress concentrations and propagate through rock as anticracks . As material is dissolved and removed, the anticrack walls move toward each other; stress and displacement fields are identical to those for the conventional opening crack, but with a change of sign. Observations of entire traces of solution surfaces are consistent with the anticrack concept: (1) the surfaces are bounded in extent; (2) the dissolved thickness varies from a maximum near the center to zero at the tips; and (3) the maximum dissolved thickness is proportional to the length of the surface. Local dissolution and in-plane propagation are suggested by the large isotropic compressive stress at the anticrack tip. Propagating solution surfaces will interact to form a regular array corresponding to some bulk strain rate. Anticracks may also interact with opening and shear cracks; observations of interacting solution surfaces, veins, and faults illustrate these configurations. Intersecting arrays of cracks, anticracks, and shear cracks operate to yield a mode of bulk deformation similar to diffusion-accommodated grain-boundary sliding in polycrystalline solids.