BGS Rock Classification Scheme

Basalt, olivine-clinopyroxene-microphyric

Code BAOCM
Description Basalt, olivine-clinopyroxene-microphyric
Qualifiers olivine   clinopyroxene  microphyric 
Definition Fine-grained, av. <0.25mm normal crystalline extrusive/intrusive rock; CI >35 vol% >40 wt%; qtz <20% or foid <10% of QAPF, feldspar >65% plag; TAS SiO2 45-52wt%, Na2O+K2O <5wt%. Larger but <0.25mm crystals of olivine<clinopyrox, both 5-20% in finer matrix
Linked data http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/BAOCM

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.