This dataset is for the manuscript "Microstructural Evolution of Micaceous Mylonites." In this study, we conducted deformation experiments (up to shear strains of γ>100) on synthetic composites of mica (fluorphlogopite) and either calcite or fluorite in the Large Volume Torsion Apparatuses (LVTs) at Washington University in St. Louis. Experiments were performed at T=765 °C, P=1.5 GPa, and strain rates of ~1x10-4 s-1. Deformation microstructures were analyzed using optical and electron microscopy and electron backscatter diffraction (EBSD). Complementary analysis was conducted on specimens from the Kuckaus Mylonite Zone in the Namaqua Metamorphic Complex in southwestern Namibia. This collection includes raw EBSD data, binarized microstructure images, and measured spine length and phase boundary density measurements.
