Delta deposit is a term used to describe the accumulation of SEDIMENT in a river delta. It is composed of SILT and SEDIMENT, which are both deposited by the river as it flows into the sea. SILT is a fine-grained material that is suspended in water and SEDIMENT is a coarser material that is deposited on the riverbed. Both SILT and SEDIMENT are important components of delta deposits, as they help to form the landforms associated with deltas.