EBSD Datasets for "An Update to Subgrain-size Piezometry: A Practical Estimate of Flow Stress in Naturally Deformed Rocks"

Differential stress—the difference between maximum compressive stress and confining pressure—is fundamental to understanding seismic activity, orogenesis, and the long-term rheology of the Earth’s crust. Stress estimation commonly relies on microstructural analysis of rock-forming minerals, with grain-size-based piezometers derived from experimentally deformed single-phase rocks. However, such piezometers often perform poorly in naturally deformed, multi-phase rocks. Subgrains, which form within mineral grains during deformation, offer a more robust alternative due to their consistent relationship with differential stress. In this study, we recalibrate a subgrain-size piezometer using EBSD data from experimentally deformed quartz and olivine, without imposing statistical assumptions, thereby minimizing bias. Application of this method to two naturally deformed quartz samples yields stress estimates consistent with conventional piezometers, demonstrating improved precision and greater suitability for complex natural systems.