Abstract

Strain localization fundamentally controls not only the local but also the bulk rheological response of a material. As such localization of deformation in zones of high strain is fundamental to how Earth deforms. Consequently, it is pivotal that we are able to extract as much information as possible from such zones, including rheology and their evolution through space and time. Many studies have shown that strain is easily localized in a polyphase rock, especially if the rock undergoes syntectonic metamorphism, metasomatism and associated weakening. Accordingly, to study shear zones, we need to integrate information derived from a whole range of disciplines including material science, structural geology, metamorphic petrology and geochronology. Results from high end analytical techniques, thermodynamic and rheological modelling underpinned by focussed field work need to be combined. This necessity offers new insights, opportunities but also challenges.

In this presentation, I will show a range of recent case studies to highlight how our understanding of high strain zones is changing as interdisciplinary and multi-technique studies become more prevalent, how such studies offer new, exciting opportunities how to “read a shear zone to the fullest”.