Caliche

(1) A layer in the soil horizon more or less cemented by secondary carbonates of calcium or magnesium precipitated from the soil solution. It may occur as a soil, thin soil horizon, as a hard, thick bed just beneath the solum, or as a surface layer exposed by erosion. Not a geologic deposit. (2) Alluvium cemented with sodium nitrate, chloride, and/or other soluble salts as in the nitrate deposits of Chile and Peru.

Source
Society for Range Management. 1998. Glossary of terms used in range management, fourth edition. Edited by the Glossary Update Task Group, Thomas E. Bedell, Chairman. Used with permission.