Scale invariant or self-similar properties have been demonstrated for a wide range of geophysical processes and rock properties. Evidence from well logs and inferences from aeromagnetic field power spectra suggest that crustal susceptibility also shows this behaviour with a power spectrum proportional to the -4 power of the spatial frequency. We examine two large susceptibility measurement data sets and find that they both support the scaling hypothesis. ¿ American Geophysical Union 1995