We measured the elastic and fluid flow properties in a ductile-brittle shear zone. The results suggest that although brittle deformation has persisted in the recent fault evolution, precursory ductile microstructure continues to control the petrophysical properties outside the fault core. The results are a glimpse into the evolutionary path of a shear zone during the ductile to brittle transition and are insightful for geothermal energy and geologic waste disposal exploitation and usage.