BGS Rock Classification Scheme
Greisen - A type of metasomatic-rock. It is a granitic-rock altered through interaction with Li-rich and F-rich, and/or B-rich, hydrothermal fluids. British Geological Survey Research Report RR/99/02, section 8.
| Code | GREIS |
|---|---|
| Description | Greisen - A type of metasomatic-rock. It is a granitic-rock altered through interaction with Li-rich and F-rich, and/or B-rich, hydrothermal fluids. British Geological Survey Research Report RR/99/02, section 8. |
| Qualifiers | No qualifiers currently exist. |
| Definition | Altered, commonly coarse-grained (av. 2-16mm) igneous rock, granite (quartz 20-60% of QAPF feldspar 35-90% alkali feldspar); significant chemical/mineralogical alteration by Li & F-/Be-rich hydrothermal fluids; alkali micas +/-tourmaline/cassiterite/topaz |
| Linked data | http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/GREIS |
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.