BGS Rock Classification Scheme

Ultramafic-melilitic-rock - A type of melilitic rock. In the Rock Classification Scheme, ultramafic-melilitic-rock and non-ultramafic-melilitic-rock are distinguished using colour index M: ultramafic-melilitic-rock has M greater than 90%. British Geological Survey Research Report RR/99/06, section 6.2 and figs. 27, 28.

Code UMMER
Description Ultramafic-melilitic-rock - A type of melilitic rock. In the Rock Classification Scheme, ultramafic-melilitic-rock and non-ultramafic-melilitic-rock are distinguished using colour index M: ultramafic-melilitic-rock has M greater than 90%. British Geological Survey Research Report RR/99/06, section 6.2 and figs. 27, 28.
Qualifiers No qualifiers currently exist.
Definition Exotic crystalline intrusive/extrusive rock, CI M>90%; >10% modal melilite, <90% clino-pyroxene, <90% olivine of Mel+Cpx+Ol; includes all known melilitic rock types
Linked data http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/UMMER

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.