Evolution of solution structures in a deformed quartz arenite: geometric changes related to permeability changes

Quartz arenite of the Silurian Keefer Sandstone at a site in West Virginia, U.S.A., records an early pervasive solution-related deformation by grain interpenetration. Volume losses measured by the PSS method show shortening directions from both diagenetic compaction and early tectonic layer-parallel shortening. Later solution-related tectonic deformation during folding formed transgranular stylolites along pre-existing faults or in rock volumes with abundant microfractures. Thus, the geometry of solution-related deformation changed progressively from pervasive at grain scale to focused along transgranular surfaces. We propose that this geometric change resulted from intense porosity and permeability reduction during diagenetic cementation and early layer-parallel shortening, which required fluids to exploit tectonically created pathways along faults or networks of microfractures during later deformation.