| Lumparn | |
|---|---|
| Lumpari | |
 Lumparn with the impact structure area in grey | |
| Impact crater/structure | |
| Confidence | Confirmed |
| Diameter | 9 km (5.6 mi) |
| Age | ~1000 Ma Proterozoic |
| Exposed | No |
| Drilled | Yes |
| Location | |
| Location | Fasta Åland |
| Coordinates | 60°9′N20°6′E / 60.150°N 20.100°E /60.150; 20.100 |
| Country |  Finland |
| Province | Åland |
| District | Åland |
| Municipality | Sund,Lumparland,Lemland &Jomala |
  Location of the crater in the Botnian Gulf | |
Lumparn (fi.Lumpari) is a largebay devoid of islands in themain island ofÅland,Finland, bordered bySund to the north,Lumparland to the east,Lemland to the south andJomala to the west.
Most of the bay fills a nine kilometer wideimpact structure. The structure is estimated to be about 1000 million years old (Proterozoic).[1] The depression was originally believed to be arift. Extraterrestrial origin was first proposed in 1979, but not until 1993 was the impact structure finally confirmed. Longshatter cones have been discovered in the southwestern part of the bay. The remains of the crater are filled with sediments. BetweenPleistocene sediments and crushedrapakivi granitebedrock there is a layer ofPaleozoic (Ordovician)limestones. This makes Lumparn one of the few places in Finland wherefossils have been found.
The bay has also previously been referred to asLumpari[2] in someFinnish documents, though theResearch Institute for the Languages of Finland does not listLumpari as in current usage.[3]
.jpg)
