Sääksjärvi () is a
lake
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...
in
Kokemäki
Kokemäki (; sv, Kumo) 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 Swedis ...
,
Satakunta
Satakunta (in both Finnish and Swedish, ) is a region ( / ) of Finland, part of the former Western Finland Province. It borders the regions of Southwest Finland, Pirkanmaa, South Ostrobothnia and Ostrobothnia. The capital city of the region ...
, western
Finland
Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...
, east from the town of
Pori. The lake is notable because it overlies an
impact crater
An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact crater ...
.
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 and
Cambrian 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 o ...
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 in Southern Ostrobothnia regions of Finland, region. It is from Lappajärvi to Seinäjoki, to Kokkola and to Vaasa. The municipality has a population of () and covers an area ...
) was known in Finland.
See also
*
Impact craters 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
