Logoisk
Key facts
- Country
- Belarus
- Diameter
- 15 km
- Age
- 42.3 ± 1.1 million years
- Location
- 54.20° N, 27.80° E
Nothing: the crater is buried beneath forest and farmland near the town of Lahojsk (Logoisk), north-east of Minsk.
Logoisk is a buried impact crater about 15 km across near the town of Lahojsk (also spelled Logoisk), north-east of Minsk, in Belarus. It is the only known impact crater in the country.
Discovery. The crater was found by accident in the 1970s, during routine exploration drilling near the village of Kuzevichi. The drill core passed through glacial deposits and lake clays and then into thick breccia, which was unexpected. Three further boreholes drilled in 1976 and 1977 confirmed a buried crater, and later drilling mapped its shape. Shock features in minerals from the breccia proved an impact.
What it hit. The impactor struck a sequence of sedimentary rocks lying on crystalline basement of granite and gneiss. The crater bowl later became a lake, whose sediments filled it.
Age. Argon dating of impact melt rock gives an age of about 42.3 million years, in the Middle Eocene, with an uncertainty of about 1 million years.
Why it matters. Logoisk is a clear example of a young crater preserved because it quickly filled with lake sediments and was then covered by glacial deposits. The impactor is unknown.
Did you know?
Logoisk was discovered by accident during routine drilling in the 1970s.
It is the only known impact crater in Belarus.
The crater once held a lake, whose sediments filled it.