In geology and archaeology, dark earth is a substratum, up to 1 meter thick, that indicates settlement over long periods of time. The material is high in organic matter, including charcoal, which gives it its characteristic dark colour; it may also contain fragments of pottery, tile, animal bone and other artefacts. It is interpreted as soil enriched with the sooty remains of thatched roofs from houses without chimneys, with other waste materials. In some areas it appears to give the soil added fertility.

Chernozem, also called black soil, regur soil or black cotton soil, is a black-colored soil containing a high percentage of humus and high percentages of phosphorus and ammonia compounds. Chernozem is very fertile soil and can produce high agricultural yields with its high moisture-storage capacity. Chernozems are a Reference Soil Group of the World Reference Base for Soil Resources (WRB)