  We study the relaxation of force distributions in the q-model, assuming a
uniform q-distribution. We show that "diffusion of correlations" makes this
relaxation very slow. On a d-dimensional lattice, the asymptotic state is
approached as a diffusion process in d-1 dimensions. Therefore the relaxation
goes as the inverse square root of depth for d=2, and the inverse depth for
d=3. Furthermore, we derive asymptotic modes of decay, along which an arbitrary
short--range correlated initial distribution will decay towards the stationary
state.
