BGS Rock Classification Scheme

Impure-coal - A type of coal. It is a lithified end-member of the impure humic coal series. The impure humic coal series can be subdivided into muddy-peat / sandy-peat (the unlithified form) and impure-coal (the lithified form). British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10.

Code IMCOL
Description Impure-coal - A type of coal. It is a lithified end-member of the impure humic coal series. The impure humic coal series can be subdivided into muddy-peat / sandy-peat (the unlithified form) and impure-coal (the lithified form). British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10.
Qualifiers No qualifiers currently exist.
Definition Sedimentary rock containing heterogeneous mixture of a wide range of plant debris. <60 to >90% carbon, dry, ash-free. Volatiles <14 to >63%. 15 to 50% ash approximately equivalent to 50 to 80% organic matter.
Linked data http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/IMCOL

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.