BGS Rock Classification Scheme

Gneiss, nebulitic

Code GNSN
Description Gneiss, nebulitic
Qualifiers nebulitic      
Definition Med-coarse-grained (av. 0.25-16mm) crystalloblastic meta rock (protolith undefined) >5mm irregular/discontinuous layers defined by contrasting text/grainsize/mineralogy, preferred mineral orientation common.Contains ghostly relicts of pre-existing rocks.
Linked data http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/GNSN

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.