Permeability-porosity relationship in vesicular basalts

The permeability k and porosity phi of vesicular basalts are measured. The relationship between k and phi reflects the formation and emplacement of th e basalts and can be related to the crystal and vesicle microstructure obta ined by image analysis. Standard theoretical models relating k: and phi tha t work well for granular materials are unsuccessful for vesicular rocks due to the fundamental difference in pore structure. Specifically, Ic in vesic ular rocks is governed by apertures between bubbles. The difference between calculated and measured k reflects the small size of these apertures with aperture radii typically O(10) times smaller than the mean bubble radii.