Kamensk
Key facts
- Country
- Russia
- Diameter
- 25 km
- Age
- about 49 million years
- Location
- 48.35° N, 40.50° E
Nothing: the crater is buried beneath the steppe of Rostov Oblast, southern Russia, near the town of Kamensk-Shakhtinsky.
Kamensk is a buried impact crater about 25 km across in Rostov Oblast, southern Russia, near the border with Ukraine. It has a small companion, the Gusev crater, a few kilometres away.
A marine impact. About 49 million years ago, in the Eocene, an asteroid fell into a shallow sea that covered the area. It punched through the water and sediments into older Palaeozoic rocks, including Carboniferous sandstones, shales and coal seams. After the impact, the sea surged back into the crater, filling it with broken rock and sediment.
Discovery. The crater lies at the edge of the Donets Basin, a coal-mining region explored with many boreholes. Drilling met breccias and melt rocks, and shock features in minerals proved an impact.
Age. Argon dating of impact glass gives an age of about 49 million years, in the Early Eocene, with an uncertainty of a few hundred thousand years.
A twin. The smaller Gusev crater, about 3 km across, has the same age. The two may have been made by a binary asteroid, a pair of bodies orbiting each other.
Why it matters. Kamensk and Gusev are among the best-studied possible double craters on Earth. The impactor is unknown.
Did you know?
Kamensk has a small companion crater, Gusev, of the same age.
It formed in a shallow sea about 49 million years ago.
It lies at the edge of the Donets coal basin, where drilling revealed it.