Eluvium

The process of removal of materials from geological or soil horizons is called eluviation or leaching.

The strict eluvial horizon (E horizon) is typically light gray, clay-depleted, contains little organic matter and has a high concentration of silt and sand particles composed of quartz and other resistant minerals.

Diamonds within yellow ground (weathered portions of kimberlites) may be considered to be eluvial deposits.

Cassiterite and columbite-tantalite deposits also occur as residual or eluvial concentrations.

Weathering supergene enrichment of an apatite rich carbonatite in Ontario has produced a significant eluvial phosphate ore deposit.