Great Groups of the Gleysolic Order
The three Great Groups of the Gleysolic order all have well-developed gley features within 50 cm of the soils surface. They differ based on the presence of a B horizon enriched in clay (Btg horizon, Luvic Gleysols), an Ah horizon (Humic Gleysols), or an absence of both of these features (Gleysol).
Luvic Gleysolic Soils:
Soils of this great group have a Btg horizon and often have an eluvial Aeg horizon overlying the clay-enriched horizon. They are very common in sloughs that hold water for part of the year throughout Southern Saskatchewan.
Humic Gleysolic Soils
These soils have an organically enriched A horizon (Ah) greater than 10 cm thick or a ploughed A horizon (Ap) greater than 15-cm thick, and have a least 3.5% organic matter in the surface horizon. In cultivated landscapes the Ah or Ap often includes topsoil that has been eroded from elsewhere in the field and deposited in the depressions.
These soils lack either a Btg or an Ah horizon. In some cases these soils develop in pond sediments created by the organisms that live in the ponds (biogenic sediments).