Shelf sediments adjacent to the Herbert River delta, Great Barrier Reef, Australia

On the Great Barrier Reef shelf, terrigenous sediments adjacent to the Herbert River delta are strongly partitioned within the coastal zone, in common with the regional presence of a terrigenous innershelf sediment wedge. Partitioning is primarily controlled by wind-driven currents and waves associated with persistent southeast trade winds. Bottom-return currents provide the likely mechanism for episodic transport of fine-grained sediment in an offshore direction, although modelled bottom-return currents appear incapable of transporting much sediment seawards beyond the 20 m isobath. This depth corresponds to the observed outer limit of the nearshore sediment wedge.