Boltysh crater Boltysh crater The Boltysh Crater (Bovtyshka Crater) is an impact crater in the Kirovohrad Oblast of Ukraine, near the village of Bovtyshka. The crater is in diameter and its age of 65.17 ± 0.64 million years, based on argon dating techniques, is within error of that of Chicxulub Crater in Mexico, and the Cretaceous–Paleogene boundary (K–Pg boundary). The Chicxulub impact is believed to have caused the mass extinction at the end of the Cretaceous period, which included the extinction of the dinosaurs. The Boltysh impact likely occurred several thousand years before Chicxulub, suggesting the extinction event may have been driven
Impact crater early in the impact by jetting. This occurs when two surfaces converge rapidly and obliquely at a small angle, and high-temperature highly shocked material is expelled from the convergence zone with velocities that may be several times larger than the impact velocity. In most circumstances, the transient cavity is not stable and collapses under gravity. In small craters, less than about 4 km diameter on Earth, there is some limited collapse of the crater rim coupled with debris sliding down the crater walls and drainage of impact melts into the deeper cavity. The resultant structure is called a simple crater,