BGS Rock Classification Scheme

Meta-alkali-feldspar-rhyolite

Code MAFRY
Description Meta-alkali-feldspar-rhyolite
Qualifiers No qualifiers currently exist.
Definition Fine-grained, av. <0.25mm, normal crystalline, extrusive/intrusive, meta-igneous rock with a field identifiable alkali-feldspar-rhyolite protolith; quartz 20-60% QAPF, feldspar >90% alkali feldspar.
Linked data http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/MAFRY

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.