BGS Rock Classification Scheme
Sediment rich in sapropel (coorongite) - A type of sediment rich in organic matter. Sapropel is the unlithified end-member of the sapropelic coal series. The members of the sapropelic coal series can be ranked in order as sapropel (the unlithified form), sapropelic-lignite, and sapropelic-coal (the lithified forms) based on increasing carbon content and decreasing volatile content. Sapropel is an unlithified dark, pulpy, fine organic mud containing concentrations of algae and miospores that are more or less identifiable. It is recommended that the term sapropel is used in preference to terms such as gyttja, dy, afja, forna etc. which have been used inconsistently and haphazardly in the past. Coorongite is a rubber-like, highly resilient structureless algal deposit. British Geological Survey Research Report RR/99/03, section 6.2, tables 17, 18, and fig. 10.
| Code | SDRSP |
|---|---|
| Description | Sediment rich in sapropel (coorongite) - A type of sediment rich in organic matter. Sapropel is the unlithified end-member of the sapropelic coal series. The members of the sapropelic coal series can be ranked in order as sapropel (the unlithified form), sapropelic-lignite, and sapropelic-coal (the lithified forms) based on increasing carbon content and decreasing volatile content. Sapropel is an unlithified dark, pulpy, fine organic mud containing concentrations of algae and miospores that are more or less identifiable. It is recommended that the term sapropel is used in preference to terms such as gyttja, dy, afja, forna etc. which have been used inconsistently and haphazardly in the past. Coorongite is a rubber-like, highly resilient structureless algal deposit. British Geological Survey Research Report RR/99/03, section 6.2, tables 17, 18, and fig. 10. |
| Qualifiers | No qualifiers currently exist. |
| Definition | Sediment undefined, >20% mud (>75% <0.032mm) of organic matter mainly miospores (spores/pollen) & algae, usually well preserved identifiable structures. <50 air dried wt% ash. High H%. Dry ash free carbon <60->70%, volatiles <52%-63%. TOC 3-100%. |
| Linked data | http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/SDRSP |
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.