Resumen
Extensive areas of active dunes are found in the Copiapó region. However, their sand supply is presently depleted. It has been proposed that deflated uplifted marine terraces of the coastal belt between the Copiapó River and Caldera were the source of the dune sand. Such a hypothesis is not supported by sedimentologic data, which suggest a fluvial origin for the aeolian sands. They could be related to Neogene alluvial accumulations built up at the mouth of the Copiapó River and the ephemeral streams located to the north of it.