BGS Rock Classification Scheme

Basanitic-foidite - A type of foiditic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 15b of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Basanitic-foidite and tephritic-foidite are distinguished by the amount of olivine in the CIPW norm: if normative olivine exceeds 10% the rock is basanitic-foidite. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19.

Code BSNFDI
Description Basanitic-foidite - A type of foiditic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 15b of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Basanitic-foidite and tephritic-foidite are distinguished by the amount of olivine in the CIPW norm: if normative olivine exceeds 10% the rock is basanitic-foidite. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19.
Qualifiers No qualifiers currently exist.
Definition Fine-grained, av.<0.25mm normal crystalline extrusive/intrusive rock; feldspathoids 60-90% of QAPF, feldspar >50% plagioclase, olivine >10%+B35
Linked data http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/BSNFDI

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.