- At the base: an erosion surface representing the base of the channel. This will be overlain by a basal lag of coarse clasts deposited on the channel floor. - A sandy bar composed of stacked sets of subaqueous dune deposits will form a succession of cross-bedded sands. - As the flow is stronger in the lower part of the channel the subaqueous dunes, and hence the cross-beds, tend to be larger at the bottom of the bar, decreasing in set size upwards. - Finer sands or silts on the top of a bar deposit represent the abandonment of the bar when it is no longer actively moving. There is therefore an overall finingup of this channel-fill succession