BGS Rock Classification Scheme

Metabasalt, plagioclase-microphyric

Code MBAPMI
Description Metabasalt, plagioclase-microphyric
Qualifiers plagioclase-microphyric      
Definition Meta-igneous rock, field identifiable plagioclase-microphyric basalt protolith. Fine-grained, av. <0.25mm normal crystalline extrus/intrus rock; CI >35 vol% >40 wt%; qtz <20% or foid <10% of QAPF, feld >65% plag. 5-20% plagioclase as <0.25mm phenocrysts.
Linked data http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/MBAPMI

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.