Shear zones as expressions of strain localization shape rocks from the micron- to the plate tectonic scale, influencing both viscous and brittle deformation systems. Strain localization across multiple scales is a complex process in any tectonic environment, and often still poorly understood. In many cases, strain localization involves feedback between mechanical, chemical and hydraulic processes that control the rheological evolution of deforming rocks. During strain localization, mylonites in shear zones evolve their fabrics, grain sizes and compositions, leading to changes in deformation mechanisms and mechanical properties. At one extreme, brittle fracturing and faulting may be coupled to shear zone processes, as evidenced by high-temperature fracturing, lower crustal earthquake nucleation, and deep fracture-controlled fluid pathways. Cyclical interplay between brittle and viscous deformation regimes may also occur. Whatever the deformation mechanism, shear zones constitute either barriers to or conduits for fluid flow, which emphasizes the significance of their dynamic transport properties.
This session seeks to illuminate deformation, metamorphic and transport processes in shear zones via a wide range of methodological approaches, including field- and microscale studies, numerical and analogue modelling approaches as well as rock deformation experiments and aims to present the latest advances in our understanding of shear zones and associated faulting. We particularly encourage early career researchers to present their findings.