We report the existence of self-organization in wet granular media or slurr
ies. mixtures of particles of different sizes dispersed in a lower density
liquid. As in the case of dry granular mixtures axial banding (alternating
bands rich in small and large particles in a long rotating cylinder) and ra
dial segregation (in quasi-2D containers) are observed in slurries. However
, when compared with the dry counterpart axial segregation is significantly
faster and the spectrum of outcomes is richer, Moreover, experiments with
suitable fluids reveal, for the first time, the internal structure of axial
ly segregated systems, something that up to now has been accessible only vi
a magnetic resonance imaging experimentation.