Sääksjärvi
The Sääksjärvi impact structure is a buried crater located beneath Lake Sääksjärvi in western Finland. With a diameter of 5 kilometers, its extraterrestrial origin is confirmed by impactite rocks found in the region. The structure dates back to approximately 543 million years ago, marking the boundary between the Ediacaran and Cambrian periods.
Key Facts
- ›Diameter of the crater is 5 kilometers.
- ›The impact structure is completely buried and not visible at the surface.
- ›Estimated age of the impact structure is 543 ± 12 million years ago.
- ›The impact occurred at the boundary between the Ediacaran and Cambrian periods.
- ›Impactite rocks confirm its extraterrestrial origin.
- ›At the time of its discovery, only one other impact crater (Lappajärvi) was known in Finland.
LappajäRvi
Impactite Rocks
About Sääksjärvi
Sääksjärvi Impact Structure
The Sääksjärvi impact structure is a significant geological feature located in western Finland, beneath the waters of Lake Sääksjärvi. This buried crater measures approximately 5 kilometers in diameter. Its extraterrestrial origin is well-established, supported by the discovery of impactite rocks in the crater's southwestern region.
Age and Geological Context
The impact event that formed Sääksjärvi is estimated to have occurred around 543 million years ago, with a margin of error of 12 million years (543 ± 12 Ma). This timing places the event precisely at the geological boundary between the Ediacaran and Cambrian periods. At the time of its scientific recognition, Sääksjärvi was only the second impact crater to be identified in Finland, with the Lappajärvi impact structure being the first.
Source: Wikipedia ↗
Frequently Asked Questions
Where is the Sääksjärvi impact crater located?
The Sääksjärvi impact structure is located beneath Lake Sääksjärvi in Kokemäki, Satakunta, western Finland. It is situated to the east of the town of Pori.
How large is the Sääksjärvi impact crater?
The crater has an estimated diameter of 5 kilometers (3 miles). It is entirely concealed by the lake and is not visible on the surface.
When did the impact event that formed Sääksjärvi occur?
The age of the Sääksjärvi impact structure is estimated to be around 543 ± 12 million years ago. This places the impact event at the boundary between the Ediacaran and Cambrian geological periods.
What evidence confirms the extraterrestrial origin of Sääksjärvi?
The extraterrestrial origin of the Sääksjärvi impact structure is confirmed by the presence of impactite rocks found in the southwestern region of the crater.
Was Sääksjärvi the first impact crater discovered in Finland?
No, at the time of its discovery, Sääksjärvi was the second impact crater known in Finland. The Lappajärvi impact crater was already known.
Related Impact Craters
Iso-Naakkima
Iso-Naakkima is a lake in Southern Savonia, Finland, notable for concealing an eroded impact crater beneath its northwestern section. It is recognized as one of the oldest known impact structures on Earth, estimated at 1200 million years old, and is also among the smallest confirmed craters of its age, measuring approximately 3 km in diameter.
Summasjärvi
Summasjärvi, also known as Lake Summanen, is a medium-sized lake in Finland that contains the 12th identified impact crater in the country. This submerged crater, located at the lake's center, measures 2.6 kilometers in diameter and is largely buried beneath later sediments. Its formation predates the Quaternary glaciation but occurred after the Svecofennian orogeny.
Keurusselkä
The Keurusselkä impact structure is a remnant of an ancient crater discovered in 2003 on the western shore of Lake Keurusselkä in Central Finland. Identified through shatter cones and shock metamorphic features in quartz, it is one of the oldest known impact structures in Europe, dating back approximately 1.14 to 1.15 billion years. Despite significant erosion, evidence suggests potential ring structures and a negative gravity anomaly, making it a subject of ongoing geological investigation.