Thurso
DERIVATION:
Sandstones and flagstones of Middle Old Red Sandstone age (Caithness Flagstones in Caithness, Rousay Flags and Stromness Flags in Orkney).
TYPES OF PARENT MATERIALS MAPPED:
- Glacial drift
- Moraine
- Partially water-sorted material overlying till
COLOUR:
Greyish brown in subsoil, locally brown - ochreous mottling pronounced.
TEXTURE:
Topsoil usually a loam texture with sandy clay loam subsoil but subsoil textures can range from sandy loam to loam. Slightly to moderately stony in subsoil.
DOMINANT LAND USE:
Permanent pasture, arable.
LANDFORMS:
Gently undulating till plain with level and gentle slopes.
SOIL CHEMISTRY:
Percentage base saturation is high in the subsoil with pH values in the range 5.5 to 7.0.
Low to moderate total phosphorus and often high molybdenum.
SOIL PHYSICAL PROPERTIES:
Potential rooting depth is around 25-30cm due to compact, moderately-fine textured subsoil which also restricts water movement through the profile. Bedrock is generally present at depths of about 1m. Massive soil structure at depth.
SERIES NAME | SOIL TYPE | DRAINAGE | PARENT MATERIAL |
---|---|---|---|
Bilbster | Humus iron podzol and podzol | Free and imperfect | Drift |
Camster | Peaty podzol | Free and imperfectbelow iron pan | Drift |
Hunster | Noncalcareous gley (SW) | Poor and very poor | Drift |
Knitchen | Alpine podzol | Free | Drift |
Mousland | Saline gley | Poor | Drift and thin drift |
Ness | Noncalcareous gley | Poor | Thin drift |
Olrig | Peaty gley (SW) | Poor and very poor | Drift |
Sibster | Noncalcareous gley | Poor | Drift with partiallysorted upper layers |
Thurso | Noncalcareous gley (SW) | Poor | Drift |
Thurskel | Skeletal soil | Variable | Very shallow driftand residual |