Erosion of coastal bedrock outcrops is releasing iron-rich deposits characteristic of many MaullĂn coastal areas. This appears to be the major process of mineral sand enrichment at the present day.
The largest resource potential is in paleodune sands, similar in composition to the modern sands, but significantly thicker.
Petrographic analysis shows that the bedrock sediment was originally derived from erosion of a more diverse Andean terrain that included both igneous and metamorphic material.
Precious metals are present along with the more typical iron and titanium oxides.