Paasselkä
Vorlage:Coor title dm Paasselkä (earlier Paasivesi) is an oval-shaped lake formed in an impact crater in Southern Savonia, Finland. The lake, which is a part of Orivesi, which is in turn part of the Greater Saimaa, is devoid of islands which makes it different from other lakes in the region. Paasselkä is also unusually deep, 75 m at the deepest point.
The age of the highly eroded 10 km wide impact structure is unknown. The impact must have occurred later than 1885 million years ago (Paleoproterozoic or later, the time when the bedrock formed in the region). Because of the unusual shape and associated magnetic anomalies, Paasselkä was suspected to have an impact origin long until it was confirmed after a deep drilling in 1999 making it the ninth known impact crater in Finland. Unlike many Finnish craters, it does not seem to have been buried under layers of sediment.
External links and references
- Earth Impact Database
- Paasselkä impact structure
- Pesonen, L. J.; Kuivasaari, T.; Lehtinen, M.; Elo, S.: Paasselkä: A New Meteorite Impact Structure in Eastern Finland. In: Meteoritics & Planetary Science. 34. Jahrgang, 1999, S. A90 – A91 (harvard.edu).