BGS Rock Classification Scheme

Metalava, basalt

Code MBALV
Description Metalava, basalt
Qualifiers basalt      
Definition Meta-igneous rock, field identifiable basalt lava protolith. Fine-grained, av. <0.25mm normal crystalline rock extruded in molten state & solidified; CI >35 vol% >40 wt%; quartz <20% or feldspathoid <10% of QAPF, feldspar >65% plagioclase; Na2O+K2O <5wt%
Linked data http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/MBALV

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.