Sääksjärvi

Infobox_lake
lake_name = Sääksjärvi
image_lake =
caption_lake =
image_bathymetry = Sääksjärvi (kraatteri).pngcaption_bathymetry =

location = Satakunta
coords = coord|61|24|N|22|24|E|type:waterbody_region:FI|display=inline,title
type = impact crater lake
inflow =
outflow =
catchment =
basin_countries = Finland
length =
width =
area = 33.18 km² [http://www.ymparisto.fi/default.asp?contentid=234185&lan=fi&clan=en Finnish Environment Institute: Finnish lakes larger than 40 square kilometers] ]
depth =
max-depth =
volume =
residence_time =
shore =
elevation = 49 m
islands =
cities =

Sääksjärvi is a lake in Kokemäki, Satakunta, western Finland, east from the town of Pori. The lake is notable because it overlies an impact crater.

The crater is 5 km 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 rocks in the southwestern region from the crater confirming its extraterrestrial origin. At the time of its discovery, only one impact crater (Lappajärvi) was known in Finland.

References

External links

* [http://www.unb.ca/passc/ImpactDatabase/images/saaksjarvi.htm Earth Impact Database]
* [http://www.somerikko.net/old/geo/imp/saaks_e.htm Sääksjärvi impact structure]