BGS Rock Classification Scheme
Semipelite - A type of metasedimentary rock composed largely of quartz, feldspar and mica. In the Rock Classification Scheme, it is one with mica component 20 - 40%, and quartz + feldspar 60 - 80% of quartz + feldspar + mica. The mica component includes all minerals other than quartz and feldspar, with the exception of calcsilicate and carbonate minerals. British Geological Survey Research Report RR/99/02, section 3.2, table 1 and fig. 5.
| Code | SEMPEL |
|---|---|
| Description | Semipelite - A type of metasedimentary rock composed largely of quartz, feldspar and mica. In the Rock Classification Scheme, it is one with mica component 20 - 40%, and quartz + feldspar 60 - 80% of quartz + feldspar + mica. The mica component includes all minerals other than quartz and feldspar, with the exception of calcsilicate and carbonate minerals. British Geological Survey Research Report RR/99/02, section 3.2, table 1 and fig. 5. |
| Qualifiers | No qualifiers currently exist. |
| Definition | Crystalloblastic metasedimentary rock (grain size & protolith undefined); modal composition <10% calc-silicate/carbonate minerals, 60-80% Q+F, 20-40% other minerals (mica/chlorite/garnet/cordierite/staurolite/andalusite/kyanite/sillimanite) |
| Linked data | http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/SEMPEL |
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.