Soils with poorly developed horizons or no horizons, and capable of further mineral alteration.
Soils with well-developed horizons or with fully weathered minerals, resulting from long-continued adjustment to prevailing soil temperature and soil water conditions.
Group I Soil: Very old, highly weathered soils of low latitudes, with a subsurface horizon of accumulation of mineral oxides and very low base status.
Group III Soil: Soils with weakly developed horizons, and formed on volcanic ash; often they are enriched with organic matter and have a dark color.
Group III Soil: Soils lacking horizons, usually because their parent material has accumulated only recently.
Soils with a large proportion of organic matter.
Group I Soil: Soils of cold, moist climates, with a well-developed B horizon (subsoil) of illuviation and low base status.
Group I Soil: Soils of dry climates, low in organic matter, and often having subsurface horizons of accumulation of carbonate minerals or soluble salts.
Group ? Soil: Soils that have permafrost near the soil surface and/or have evidence of cryoturbation (frost churning) and/or ice segregation.
Group II Soil: Soils with a thick upper layer very rich in organic matter. Muck soil is an example.
Group III Soil: Soils with weakly developed horizons, having minerals capable of further alteration by weathering processes.
Group I Soil: Soils of humid and sub-humid climates with a subsurface horizon of clay accumulation and high base status. Range from equatorial to subarctic latitude zones.
Group I Soil: Soils of subtropical and tropical zones with high clay content and high base status (develop deep, wide cracks when dry, and the soil blocks formed by cracking move with respect to each other.
Group I Soil: Soils of equatorial, tropical, and subtropical latitude zones, with a subsurface horizon of clay accumulation and low base status.
Group I Soil: Soils of semiarid and sub-humid midlatitude grasslands, with a dark, humus-rich epipedon and very high base status.
Group I Soils
Group II Soils
Group III Soils
