Percolation and the pore geometry of crustal rocks

Properties of isostatically compacted aggregates provide insight into the transport properties and the pore-space morphology of sedimentary rocks at depth in the Earth's crust. Here we provide evidence that percolation provides a natural description of the evolution of pore-space topology in compacted aggregates. Topological and transport properties of isostatically compacted aggregates measured by Zhang et al. [J. Geophys. Res. 99, 15 741 (1994)] are modeled as a percolation process. Critical exponents associated with both topological quantities and transport properties are measured near the percolation transition and are consistent with the ordinary percolation universality class. We discuss how the use of percolation concepts (e.g., the backbone) facilitates the improved modeling of fluid migration in the crust.