The special issue provides an overview of recent advances in the study of deformation mechanisms and microstructures and the process of ductile strain localization in the lithosphere. Microstructures and textures (crystallographic preferred orientations) represent the link between natural and experimental rock deformation, allowing extrapolation and application of laboratory data to natural shear zones and rock rheology. The investigation of progressive microstructural development and related deformation mechanisms in shear zones is therefore of prime importance for understanding strain localization, which occurs throughout the lithosphere and determines the lithospheric strength and general geodynamic processes. Recent contributions have highlighted the interactions between fracturing and ductile deformation under a wide range of P and T conditions, as well as the importance of planar rheological heterogeneities for shear zone localization in the crust and mantle. These aspects need to be further explored in order to achieve a quantitative understanding of the mechanical behavior of the lithosphere and of the resulting distribution of deformation.

The special issue welcomes (but is not limited to) contributions presented at the session "Ductile deformation and its interaction with brittle fracture: fabrics, strain localization, fluid-rock interaction and metamorphic conditions" at the EGU General Assembly 2014, and aims to present a mix of both review papers and original research studies.