This paper introduces local porosity distributions
and local percolation probabilities as welldefined
and experimentally observable geometric characteristics
of general porous media.
Based on these concepts the dielectric response is analyzed
using the effective-medium approximation and percolation scaIing theory.
The theoretical origin of static and dynamic scaling laws
for the dielectric response incIuding Archie’s law
in the low-porosity limit are elucidated.
The zero-frequency real dielectric constant is found
to diverge as in the high-porosity limit,
where denotes the porosity and is analogous to the cementation exponent.
ModeI calculations are presented for the interplay
between geometric characteristics and the frequency-dependent dieIectric response.
Three pureIy geometric mechanisms are identified,
each of which can give rise to a large dielectric enhancement.