| Siljan Ring | |
|---|---|
 Satellite photo of the Siljan Ring. Lake Siljan takes up a large part of the southwestern edge of the now much-eroded crater. | |
| Impact crater/structure | |
| Confidence | Confirmed |
| Diameter | 52 km (32 mi) |
| Age | 376.8 ± 1.7 Ma Frasnian |
| Exposed | Yes |
| Drilled | Yes |
| Location | |
| Coordinates | 61°02′N 14°55′E / 61.04°N 14.92°E |
| Country | Sweden |
| District | Dalarna |
  Location of the crater in Sweden | |
The Siljan Ring (Swedish: Siljansringen) is a prehistoric impact structure in Dalarna, central Sweden.[1] It is one of the 15 largest known impact structures on Earth and the largest in Europe, with a diameter of about 52 kilometres (32 mi). The impact that created the Siljan Ring occurred when a meteorite collided with the Earth's surface during the Devonian period. The exact timing of the impact has been estimated at 376.8 ± 1.7 Ma[2] or at 377 ± 2 Ma.[3] This impact has been proposed as a cause of the first Devonian extinction, the Kellwasser Event or Late Frasnian extinction,[4][5] due to it being believed by some researchers to coincide around the time of the Kellwasser event at 376.1 Ma ± 1.6 Ma,[6] although the timing of this extinction event has since been pushed forward to 371.93–371.78 Ma.[7] The effects of the impact can clearly be seen in the bedrock in the area. The Cambrian, Ordovician and Silurian sedimentary rocks deformed by the impact are rich in fossils.
The area around the Siljan Ring has been the site of recent prospecting for oil and natural gas, though none of the projects has so far been commercially viable. There are large deposits of lead and zinc near Boda at the eastern edge of the Ring.
There are several lakes in the vicinity, the largest of which is Siljan on the south-southwestern edge of the crater, with the smaller Orsa Lake to the west and Skattungen and Ore on the northeastern margin.
- ^ Cite error: The named reference
glasby2006gold1992was invoked but never defined (see the help page). - ^ "Siljan". Earth Impact Database. Planetary and Space Science Centre University of New Brunswick Fredericton. Retrieved 2017-10-09.
- ^ Reimold, Wolf U.; Kelley, Simon P.; Sherlock, Sarah C.; Henkel, Herbert; Koeberl, Christian (26 January 2010). "Laser argon dating of melt breccias from the Siljan impact structure, Sweden: Implications for a possible relationship to Late Devonian extinction events". Meteoritics & Planetary Science. 40 (4): 591–607. doi:10.1111/j.1945-5100.2005.tb00965.x. S2CID 23316812. Retrieved 14 January 2023.
- ^ Claeys, Philippe; Casier, Jean-Georges (April 1994). "Microtektite-like impact glass associated with the Frasnian-Famennian boundary mass extinction". Earth and Planetary Science Letters. 122 (3–4): 303–315. Bibcode:1994E&PSL.122..303C. doi:10.1016/0012-821X(94)90004-3. Retrieved 14 January 2023.
- ^ Claeys, Philippe; Casier, Jean-Georges; Margolis, Stanley V. (21 August 1992). "Microtektites and Mass Extinctions: Evidence for a Late Devonian Asteroid Impact". Science. 257 (5073): 1102–1104. Bibcode:1992Sci...257.1102C. doi:10.1126/science.257.5073.1102. PMID 17840279. S2CID 40588088. Retrieved 14 January 2023.
- ^ J.R. Morrow and C.A. Sandberg (2005). Revised Dating Of Alamo And Some Other Late Devonian Impacts In Relation To Resulting Mass Extinction, 68th Annual Meteoritical Society Meeting (2005)
- ^ Percival, L. M. E.; Davies, J. H. F. L.; Schaltegger, U.; De Vleeschouwer, D.; Da Silva, A.-C.; Föllmi, K. B. (22 June 2018). "Precisely dating the Frasnian–Famennian boundary: implications for the cause of the Late Devonian mass extinction". Scientific Reports. 8 (1): 9578. Bibcode:2018NatSR...8.9578P. doi:10.1038/s41598-018-27847-7. PMC 6014997. PMID 29934550.