The vertical and lateral variability in grain-size distributions and mineralogy of sandstone turbidites in the Oligocene Krosno Formation suggests that two different relationships between grain-size sorting and mineralogical sorting result during transport by turbidity currents. In one relationship, mineralogical sorting is associated with size sorting. The two sorting processes operate simultaneously and each of the mineral constituents has its individual grain-size distribution within the rock's composite grain-size distribution. In the second relationship, mineralogical sorting is independent of size sorting. This suggests that in granulometrically homogeneous source materials, the grains are fractionated according to settling velocities determined by their density and dynamic shape factors.