Thick, red, and greatly weathered and altered strata of tropical ground. Horizons are unclear and the nutrient status of the soil is low. See Bourman (2007) Geog. Res. 45, 3. Laterite is soft but gets brick-hard when exposed to the air. Lateritic soils (latosols) are tropical/equatorial soils characterized by a deep weathered layer from which silica has been leached, a lack of humus, and an accumulation or layer of aluminium and iron sesquioxides. Laterization is the formation of lateritic soils, taking place in warm climates where bacterial activity takes place throughout the year. D. Nahon (1991) argues that ferric duricrusts result from long-term laterization processes and as a consequence are extremely widespread in tropical environments.