The dominant lines of inquiry during the period center on how rock damage pathways shift from brittle faulting to cataclastic flow in porous sandstones and how these transitions govern fragmentation, permeability, and reservoir behavior. Researchers increasingly combine mechanical experiments, microstructural observations, and fracture statistics to link stress paths, porosity, and deformation regimes to fragmentation outcomes. Nondestructive assessment methods, such as analyzing microcrack-induced elastic wave anisotropy, complemented simpler fractal descriptions of fracture surfaces to forecast fragmentation patterns.