Permeability‐porosity relationship in vesicular basalts

Abstract

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