noun
- Material (such as clay, iron oxide, or organic matter) that has been leached from upper soil layers and deposited in lower layers.
Usage: soil science; technical term
Examples
- The illuvium accumulated in the B horizon of the soil profile.
- Clay minerals in the illuvium give the lower soil layer a darker color.
- Soil scientists study illuvium to understand nutrient movement through the ground.
- The illuvium layer contains concentrated iron oxides from the weathered parent material above.