BGS Rock Classification Scheme
Smectite-claystone - A type of monomineralic aluminium-silicate sedimentary rock in which the aluminium-silicate mineral is smectite. It is the lithified equivalent of smectite-clay. Bentonite and fullers earth may be considered synonyms for smectite-claystone. Bentonite is a soft, plastic, porous, light-coloured rock composed essentially of clay minerals from the smectite group plus colloidal silica, and produced by chemical alteration of volcanic ash. Fullers earth is a clay consisting largely of hydrated aluminium silicates (e.g. smectite), with a high proportion of water and little plasticity. It is formed by in-situ decomposition of igneous rocks containing a high proportion of glass. British Geological Survey Research Report RR/99/03, sections 9.1 and 13.6, and table 19.
| Code | SMCCST |
|---|---|
| Description | Smectite-claystone - A type of monomineralic aluminium-silicate sedimentary rock in which the aluminium-silicate mineral is smectite. It is the lithified equivalent of smectite-clay. Bentonite and fullers earth may be considered synonyms for smectite-claystone. Bentonite is a soft, plastic, porous, light-coloured rock composed essentially of clay minerals from the smectite group plus colloidal silica, and produced by chemical alteration of volcanic ash. Fullers earth is a clay consisting largely of hydrated aluminium silicates (e.g. smectite), with a high proportion of water and little plasticity. It is formed by in-situ decomposition of igneous rocks containing a high proportion of glass. British Geological Survey Research Report RR/99/03, sections 9.1 and 13.6, and table 19. |
| Qualifiers | No qualifiers currently exist. |
| Definition | Not Available |
| Linked data | http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/SMCCST |
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.