Wijde Bay Formation
| Wijde Bay Formation | |
|---|---|
| Stratigraphic range: Givetian | |
| Type | Formation |
| Unit of | Andrée Land Group |
| Overlies | Grey Hoek Formation |
| Location | |
| Region | Spitsbergen, Svalbard |
| Country | Norway |
The Wijde Bay Formation is a geologic formation located on the island of Spitsbergen in the Svalbard archipelago of Norway. It dates to the Givetian stage of the Middle Devonian and is known for its well-preserved terrestrial and freshwater fossils. It forms part of the Old Red Sandstone deposits in the region and was originally referred to as the "Wijdefjorden Series" or "Wijde Bay Series".[1]
Geological setting
[edit]The Wijde Bay Formation belongs to the Andrée Land Group and was deposited in an extensive continental basin during the Devonian. It unconformably overlies older units such as the Grey Hoek Formation and is composed predominantly of reddish to brown sandstones, conglomerates, and mudstones, typical of a fluvial to alluvial plain environment.[2]
The formation reaches a thickness of up to 2,000 meters in places, indicating a long period of sediment accumulation under varying climatic and tectonic regimes.[3]
Paleontology
[edit]Fossil assemblages from the Wijde Bay Formation include a variety of freshwater fish, plant remains, and invertebrates. These fossils offer crucial insights into the development of early terrestrial ecosystems during the Devonian, often termed the "Age of Fishes".[4]
Notable fossil finds include:
- Placoderms (armored fish)
- Acanthodians (spiny sharks)
- Early lycopods and primitive vascular plants[5]
History of investigation
[edit]The formation was first described during early 20th-century geological expeditions to Svalbard, with initial terminology including "Wijdefjorden Series". The name was later formalized as the Wijde Bay Formation and assigned to the Andrée Land Group through detailed lithostratigraphic revision.[6]
Extensive mapping and stratigraphic correlation by the Norwegian Polar Institute and international researchers have since refined the understanding of this formation.[7]
Significance
[edit]The Wijde Bay Formation is significant for understanding Devonian paleoenvironments in the Arctic and helps establish biostratigraphic links between Svalbard and other parts of the ancient Old Red Sandstone continent, such as Scotland and East Greenland.[8]
The formation provides key data for reconstructing continental positions, climatic trends, and the biological evolution of vertebrates and plants in the mid-Paleozoic Arctic.[9]
References
[edit]- ^ Piepjohn, K.; Dallmann, W.K. (2014). "Stratigraphy of the uppermost Old Red Sandstone of Svalbard (Mimerdalen Subgroup)". Polar Research. 33 (1). doi:10.3402/polar.v33.19998.
- ^ Harland, W. Brian (1997). The Geology of Svalbard. Geological Society of London. pp. 186–193.
- ^ Friend, P. F.; Mohr, M. (2000). "Devonian evolution of alluvial systems in the Old Red Sandstone continent". Geological Society, London, Special Publications. 180: 137–168. doi:10.1144/GSL.SP.2000.180.01.08.
- ^ Blieck, A.R.M. (1997). "Devonian vertebrate biostratigraphy and paleogeography of Svalbard". Geodiversitas. 19 (3): 347–367.
- ^ Edwards, D. (2002). "Plants in the Devonian: a world in transition". Philosophical Transactions of the Royal Society B. 357 (1422): 633–655. doi:10.1098/rstb.2001.0997.
- ^ Dallmann, W. K. (2007). Geological map of Svalbard 1:100,000, sheet C9G Kongsfjorden. Norwegian Polar Institute.
- ^ "Geology of Svalbard". Norwegian Polar Institute. Retrieved 13 June 2025.
- ^ Trewin, N.H. (2001). "The Old Red Sandstone basins and their faunas". Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 91 (4): 477–493. doi:10.1017/S0263593300007441.
- ^ Benton, M. J. (1987). "Origin and relationships of major vertebrate groups". Biological Reviews. 62: 295–339. doi:10.1111/j.1469-185X.1987.tb00665.x.