BGS Rock Classification Scheme
Tufa - A type of chemical deposit (natural superficial). It is a sedimentary rock composed of calcium carbonate or silica, formed by evaporation as a thin, surficial, soft, spongy, semifriable encrustation around the mouth of springs, seeps or along streams carrying calcium carbonate in solution, and exceptionally as a thick deposit along lake shores. Travertine is a hard, dense variety of tufa; it also occurs in caves as stalactites and stalagmites. British Geological Survey Research Report RR/99/03; RR/99/04, appendix 2 and tables 5, 17. Synonyms: sinter, travertine.
| Code | TUFA |
|---|---|
| Description | Tufa - A type of chemical deposit (natural superficial). It is a sedimentary rock composed of calcium carbonate or silica, formed by evaporation as a thin, surficial, soft, spongy, semifriable encrustation around the mouth of springs, seeps or along streams carrying calcium carbonate in solution, and exceptionally as a thick deposit along lake shores. Travertine is a hard, dense variety of tufa; it also occurs in caves as stalactites and stalagmites. British Geological Survey Research Report RR/99/03; RR/99/04, appendix 2 and tables 5, 17. Synonyms: sinter, travertine. |
| Qualifiers | No qualifiers currently exist. |
| Definition | Thin, surficial, soft, spongy, semifriable, crystalline incrustation around the mouth of springs, seeps or streams carrying calcium carbonate in solution & exceptionally as thick deposits along lakeshores. Tufa-limestone. |
| Linked data | http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/TUFA |
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.