BGS Rock Classification Scheme
Foidolite - A type of foidolitic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 15 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. This field contains rocks in which the light-coloured minerals are almost entirely feldspathoids. The fine-grained equivalent is foidite. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12.
| Code | FDO |
|---|---|
| Description | Foidolite - A type of foidolitic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 15 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. This field contains rocks in which the light-coloured minerals are almost entirely feldspathoids. The fine-grained equivalent is foidite. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. |
| Qualifiers | No qualifiers currently exist. |
| Definition | Coarse-grained, av. between 2-16mm normal crystalline intrusive rock; feldspathoids >60%, feldspar <40% of QAPF, +/- mica/pyroxene |
| Linked data | http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/FDO |
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.