ferricrust

Ferricrete is a type of duricrust, which is a hardened layer formed in or on soil. This layer is created when soil particles are cemented together by iron oxides, such as Fe₂O₃, precipitated from groundwater. This process results in an erosion-resistant layer.1

Ferricrete formations can be significant sources of iron ores like limonite or hematite. While the term "laterite" is often used interchangeably with ferricrete, it technically refers to a soil that is rich in iron and aluminum oxides. Duricrusts, in general, are hardened accumulations of silica, alumina, and iron oxide, and can also include other substances. They are typically found in intertropical to subtropical regions and are often remnants of past climatic and geological conditions.12