A unifying theory has recently been developed that offers a way to determine the relative contributions of pure and simple shear to the total strain in the rock even when traditional strain markers are absent. It can explain micro- and meso-scale structures, including shear bands, forward and back-rotated boudins, and other features that were previously thought to be contradictory. This project will extend the theory by calculating the trajectories for deformable ellipsoidal porphyroclasts of varying viscosity contrast to their matrix. The theory will be tested using a suite of samples from shear zones in well-established tectonic settings. The establishment of the proposed methodology as a standard technique for structural analysis should have wide application.
