Classification
Most soil classifications divide the gley soils into surface-water gleys (also known as stagnogleys) and gleys proper, or groundwater gleys, the former having a slowly pemeable lower subsoil, leading to a "perched" water table, the latter being in low ground or basin situations where the natural groundwater table is constantly high enough to influence the soil profile.
Gley soil is grouped under Gleysols in the FAO World Reference Base for Soil Resources.
Read more about this topic: Gley Soil