Lockne crater

Lockne is a meteorite crater, located approximately south of the city of Östersund in northern Sweden. It has been suggested that it is a doublet with the nearby smaller Målingen Crater, apart. Computer simulations suggest that the asteroid that created the Lockne crater was some in diameter, and the one that carved out Målingen crater was about across.
It is in diameter and the age is estimated, based on accompanying chitinozoan microfossils, to be 458 million years (Late Ordovician). The crater is exposed at the surface. Its fossils, typical of shallow marine environments, show it to be a marine target impact event.