Distinct sediment sources can be inferred for Benguela sand spits on the basis of textural and compositional data.

Coporolo River bedload is diluted in sediment continuously supplied by coastal units.

Beach deposits in the Catumbela-Lobito coastal stretch are mainly sourced by the Catumbela River.

Kaolinite is derived mainly from Angola hinterland ​and expansive clays from the Benguela Basin.

An important proportion of the fine grained sediment is derived from local littoral sources.