Fine substrata where ≥ 80 % of the grains are between 0.0039-0.0625 mm in any dimension.
Level 4 definitions
- Very Fine Silt: A silt where particles between 0.0039-0.0078 mm in any dimension are dominant (i.e. constitute ≥ 80% of the silt).
- Fine Silt: A silt where particles between 0.0078-0.0156 mm in any dimension are dominant (i.e. constitute ≥ 80% of the silt).
- Medium Silt: A silt where particles between 0.0156-0.0310 mm in any dimension are dominant (i.e. constitute ≥ 80% of the silt).
- Coarse Silt: A silt where particles between 0.0310-0.0625 mm in any dimension are dominant (i.e. constitute ≥ 80% of the silt).
