BGS Rock Classification Scheme

Metamafic-rock - A class within meta-igneous rock based on modal composition. In the Rock Classification Scheme, these are coarse-grained meta-igneous rocks containing 35 - 90% mafic minerals. British Geological Survey Research Report RR/99/02, section 5.2 and figs. 1, 8 and 9.

Code MMR
Description Metamafic-rock - A class within meta-igneous rock based on modal composition. In the Rock Classification Scheme, these are coarse-grained meta-igneous rocks containing 35 - 90% mafic minerals. British Geological Survey Research Report RR/99/02, section 5.2 and figs. 1, 8 and 9.
Qualifiers No qualifiers currently exist.
Definition Meta-igneous rock (grain size undefined), (protolith undefined) with <65% quartz, <65% feldspar, 35-90% mafic minerals of Q+F+mafic minerals; includes some green-stone/schist/blueschist/spillite
Linked data http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/MMR

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.