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,
Satakunta, 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
)
, website www.pori.fi
Pori (; sv, Björneborg ) is a city and municipality on the west coast of Finland. The city is located some from the Gulf of Bothnia, on the estuary of the Kokemäki River, west of Tampere, north of Turku and north-w ...
. The lake is notable because it overlies an
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
The Ediacaran Period ( ) is a geological period that spans 96 million years from the end of the Cryogenian Period 635 million years ago (Mya), to the beginning of the Cambrian Period 538.8 Mya. It marks the end of the Proterozoic Eon, and th ...
and
Cambrian
The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ...
periods. There are
impactite 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 municipality in Finland in Southern Ostrobothnia region. It is from Lappajärvi to Seinäjoki, to Kokkola and to Vaasa. The municipality has a population of () and covers an area of of which is water. The population density ...
) was known in Finland.
See also
*
Impact craters in Finland As of June 2018, 12 confirmed impact craters have been found in Finland. They are listed below, sorted by original diameter.
Note 1: The "original" crater dimensions are coarse estimates. Original depths were calculated using the given original dia ...
References
External links
*
Sääksjärvi impact structure
Impact craters of Finland
Proterozoic impact craters
Kokemäenjoki basin
Lakes of Kokemäki
Impact crater lakes
{{Earth-crater-stub