Braksøya Formation
Norwegian geological formation
Braksøya Formation | |
---|---|
Stratigraphic range: Sheinwoodian ~428–426 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓ | |
Type | Formation |
Overlies | Ringerike & Modum: Bruflat Formation Skien & Holmestrand: Porsgrunn & Skinnerbukta Formations |
Lithology | |
Primary | Limestone |
Location | |
Coordinates | ![]() ![]() Braksøya Formation (Norway) |
The Braksøya Formation is a geologic formation in the Ringerike and Modum areas in Buskerud, Norway, where it overlies the Bruflat Formation and the Skien and Holmestrand areas where it overlies the Porsgrunn Formation and Skinnerbukta Formation respectively.[1] The formation, deposited in a shallow Caledonian foreland basin at the edge of a closing Iapetus Ocean,[2] preserves fossils dating back to the Sheinwoodian stage of the Silurian period.[3]
Fossil content
![](http://upload.wikimedia.org/wikipedia/commons/thumb/b/bb/Laurasia_430Ma.jpg/250px-Laurasia_430Ma.jpg)
The stromatoporoid bioherms of the Braksøya Formation have provided fossils of:[3][4]
- Stromatoporida
- Syringostromellidae
- Syringostromella cf. aspectabilis
- Syringostromellidae
- Actinostromatida
- Actinostromatidae
- Plectostroma norvegicum
- Actinostromatidae
- Clathrodictyida
- Clathrodictyidae
- Clathrodictyon cf. crickmayi
- Clathrodictyidae
See also
- List of fossiliferous stratigraphic units in Norway
- Buildwas Formation, Sheinwoodian type formation in England
- Llallagua Formation, Sheinwoodian fossiliferous formation in Bolivia
References
- ^ Worsley et al., 2011, p.102
- ^ Worsley et al., 2011, p.117
- ^ a b Braksøya Formation at Fossilworks.org
- ^ Nestor, 1999
Bibliography
- Worsley, D.; Baarli, B. G.; Howe, M. P. A.; Hjaltason, F.; Alm, D. (2011), "New data on the Bruflat Formation and the Llandovery/Wenlock transition in the Oslo Region, Norway", Norsk Geologisk Tidsskrift, 91: 101–120
- Nestor, H (1999), "Community structure and succession of Baltoscandian Early Palaeozoic stromatoporoids", Proceedings of the Estonian Academy of Sciences, 48: 123–139