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Sundvollen Formation

Coordinates: 59°54′N 10°48′E / 59.9°N 10.8°E / 59.9; 10.8
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Sundvollen Formation
Stratigraphic range: Gorstian-Ludfordian (Rootsiküla)
~426.2–423 Ma
TypeFormation
Unit ofRingerike Group
UnderliesStubdal Formation
OverliesSteinsfjorden Formation
Lithology
PrimarySandstone
OtherSiltstone, shale
Location
Coordinates59°54′N 10°48′E / 59.9°N 10.8°E / 59.9; 10.8
Approximate paleocoordinates16°54′S 7°18′W / 16.9°S 7.3°W / -16.9; -7.3
RegionOslo Region, Ringerike
Country Norway
ExtentNorth and eastern Steinsfjorden
Sundvollen Formation is located in Norway
Sundvollen Formation
Sundvollen Formation (Norway)

The Sundvollen Formation is a geologic formation cropping out along the northern and eastern shores of Steinsfjorden, Oslo Region, Norway. It preserves fossils dating back to the Gorstian to Ludfordian stages (Rootsiküla in the regional stratigraphy) of the Late Silurian period.[1]

Description

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The formation belongs to the Ringerike Group,[2] overlies the Steinsfjorden Formation and is overlain by the Stubdal Formation. The fish assemblage originates from a horizon with fine-grained, dark greyish-green sandstone from the lowermost part of the formation.[3]

The formation comprises dark-grey siltstones associated with red sandstones and siltstones, with ripple marks, cross-laminations, and crack diapirs, and pseudo-nodules, carbonate concretions. The sequence is fining upwards in cyclothems. Tracks attributed to eurypterids have been found in the red siltstone. Turner (1974) interprets the Sundvollen Formation as representing meandering, braided streams on an alluvial, coastal plain, very close to sea level because of the minor marine incursions found). Boucot and Janis (1983) interpreted the environment to be possibly brackish-estuarine.[4]

Fossil content

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The following fossils have been reported from the formation:[1]

Fish

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Eurypterids

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Invertebrates

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Crustaceans
Chasmataspidids
Xiphosura

Flora

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Correlations

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The Sundvollen Formation correlates with the lower part of the Store Arøya Formation.[3]

See also

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References

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  1. ^ a b Sundvollen Formation at Fossilworks.org
  2. ^ Bremer et al., 2019, p.129
  3. ^ a b Bremer et al., 2019, p.132
  4. ^ Eurypterid-Associated Biota of the Sundvollen Form. at Rudstangen at Fossilworks.org
  5. ^ a b c d e f g h i j k l m n Plotnick, 1999
  6. ^ Bremer et al., 2019, p.142
  7. ^ a b Bremer et al., 2019, p.144
  8. ^ a b c d Baarli et al., 1999
  9. ^ a b c Bremer et al., 2019, p.145
  10. ^ Bremer et al., 2019, p.146
  11. ^ Brookfield, M. E. (2024). "The Life and Death of Jamoytius kerwoodi White; A Silurian Jawless Nektonic Herbivore?". Fossil Studies. 2 (2): 77–91. doi:10.3390/fossils2020003.

Bibliography

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