BGS Rock Classification Scheme

Metabasalt, olivine-microphyric

Code	MBAOMI
Description	Metabasalt, olivine-microphyric
Qualifiers	olivine-microphyric
Definition	Meta-igneous rock, field identifiable olivine-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% larger <0.25mm oliv crys in finer matrix
Linked data	http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/MBAOMI

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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.