BGS Rock Classification Scheme

Iron-mud - A type of iron-sediment. In the Rock Classification Scheme, it is one in which over 75% of the clasts are smaller than 32 µm. The grain size classes are defined in the same way as the siliciclastic sediments. British Geological Survey Research Report RR/99/03, section 5.1, table 13 and fig. 9. See also: silicate-mud.

Code FEMUD
Description Iron-mud - A type of iron-sediment. In the Rock Classification Scheme, it is one in which over 75% of the clasts are smaller than 32 µm. The grain size classes are defined in the same way as the siliciclastic sediments. British Geological Survey Research Report RR/99/03, section 5.1, table 13 and fig. 9. See also: silicate-mud.
Qualifiers No qualifiers currently exist.
Definition Sediment (>15wt % iron) with particles >50% iron-bearing minerals (15wt% iron). Particles >50% or predominantly mud-grade, <0.032mm.
Linked data http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/FEMUD

CAVEAT

"Thumbnail" definitions attached to some of the table entries are an interim attempt to provide simple short descriptions of the "unqualified" rock types presented within the BGS Rock Classification Scheme. Every effort has been made to ensure accuracy and consistency but minor contradictions or omissions might be present. The BGS welcomes any feedback pointing out such minor imperfections and/or providing constructive comment and suggestions for improvement of the definitions. In the first instance such feedback should be directed to Dr Tim McCormick.