BGS Rock Classification Scheme

Nepheline-monzosyenite - A foid-monzosyenite in which the dominant feldspathoid mineral is nepheline. British Geological Survey Research Report RR/99/06, section 5.1 and fig. 9.

Code NMZSY
Description Nepheline-monzosyenite - A foid-monzosyenite in which the dominant feldspathoid mineral is nepheline. British Geological Survey Research Report RR/99/06, section 5.1 and fig. 9.
Qualifiers No qualifiers currently exist.
Definition Coarse-grained, av. between 2-16mm normal crystalline intrusive with feldspathoids, nepheline (dominant)10-60% of QAPF, feldspar 50-90% alkali feldspar; +/-mica/amphibole/pyroxene/olivine
Linked data http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/NMZSY

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.