Cretaceous–Paleogene boundary had been that no documented crater matched the event. This was not a lethal blow to the theory; while the crater resulting from the impact would have been larger than in diameter, Earth's geological processes hide or destroy craters over time. The Chicxulub crater (; ) is an impact crater buried underneath the Yucatán Peninsula in Mexico. Its center is located near the town of Chicxulub, after which the crater is named. It was formed by a large asteroid or comet about in diameter, the Chicxulub impactor, striking the Earth. The date of the impact coincides precisely with the Cretaceous–Paleogene
Rochechouart crater From the morphology of the crater floor and the impact deposit it is clear the initial crater is much larger than the 12 km zone where outcrops the remnants of the crater fill deposit. In the # 4–25 km diameter range, terrestrial impact craters are developing a central high, such as Boltysh crater, a 24 km impact crater in Ukraine. Like Rochechouart, Boltysh formed exclusively in crystalline basement. The crater is buried yet the deeper structure is known through numerous drill cores and geophysical investigation undertaken during the Soviet period in the search of hydrocarbons. The central high at Boltysh