  We probe the rheology of weakly vibrated granular flows as function of flow
rate, vibration strength and pressure by performing experiments in a vertically
vibrated split-bottom shear cell. For slow flows, we establish the existence of
a novel vibration dominated granular flow regime, where the driving stresses
smoothly vanish as the driving rate is diminished. We distinguish three
qualitatively different vibration dominated rheologies, most strikingly a
regime where the shear stresses no longer are proportional to the pressure.
