Sääksjärvi () is a

lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...

Kokemäki Kokemäki (; ) is a town and municipality in the Satakunta Region of Finland. The town has a population of () and covers an area of of which is water. The population density is . Finland is constitutionally bi-lingual with a Swedish speakin ...

Satakunta Satakunta (in both Finnish language, Finnish and Swedish language, Swedish, ; historically ''Satacundia'') is a Regions of Finland, region ( / ) of Finland, part of the former Western Finland Province. It borders the regions of Southwest Finland ...

, western

Finland Finland, officially the Republic of Finland, is a Nordic country in Northern Europe. It borders Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland to the south, ...

, east from the town of

Pori Pori (; ; ) is a city in Finland and the regional capital of Satakunta. It is located on the west coast of the country, on the Gulf of Bothnia. The population of Pori is approximately , while the Pori sub-region, sub-region has a population of a ...

. The lake is notable because it overlies an

impact crater An impact crater is a depression (geology), depression in the surface of a solid astronomical body formed by the hypervelocity impact event, impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal c ...

. The crater is in diameter and is completely buried under the lake and is not visible at the surface. The age of the impact structure is estimated to be about 543 ± 12 Ma (million years ago), at the boundary between the

Ediacaran The Ediacaran ( ) is a geological period of the Neoproterozoic geologic era, Era that spans 96 million years from the end of the Cryogenian Period at 635 Million years ago, Mya to the beginning of the Cambrian Period at 538.8 Mya. It is the last ...

and

Cambrian The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordov ...

periods. There are

impactite Impactite is rock created or modified by one or more impacts of a meteorite. Impactites are considered metamorphic rock, because their source materials were modified by the heat and pressure of the impact. On Earth, impactites consist primarily ...

rocks in the southwestern region from the crater confirming its extraterrestrial origin. At the time of its discovery, only one impact crater (

Lappajärvi Lappajärvi is a municipalities of Finland, municipality in Finland's Southern Ostrobothnia region. It is located from Seinäjoki, from Kokkola and from Vaasa. The municipality has a population of () and covers an area of of which , or near ...

) was known in Finland.

References

External links

*
Sääksjärvi impact structure
Impact craters of Finland Proterozoic impact craters Kokemäenjoki basin Lakes of Kokemäki Impact crater lakes {{Earth-crater-stub

See also

References

External links