Regosolic soils lack significant soil formation and occur typically on very young surfaces (such as sand dunes or river floodplains) or unstable surfaces (such as slope positions that experience high rates of soil erosion). Regosolic soils either completely lack a B horizon or have a thin B less than 5 cm thick. In rolling or hummocky agricultural landscapes in Saskatchewan, the soils on the knolls have often been heavily eroded by tillage and the calcium carbonate-rich C horizon become mixed by tillage into the A horizon. This Apk horizon often directly overlies the C horizon. In sand dunes or recent river floodplain deposits there may be no A horizon and the C horizon extends to the surface of the soil.
Two great groups of the Regosolic Order occur in Saskatchewan.
These soils have an A horizon (including an Apk) equal to or greater than 10 cm thick and either no B horizon or one thinner than 5 cm.
These soils lack an A horizon or have one thinner than 10 cm, and have either a thin or no B horizon. They are most common on recent sediments such as sand dunes or floodplains.
