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
Peak ring (crater) develop during crater formation. The peak-ring structure of Chicxulub crater was probably formed as inward-collapsing material impacted the over-steepened central peak, to form a hydraulic jump at the location where the peak ring was located. Other theories have been formulated. Perhaps, in the case of Chicxulub crater, an over-high central peak collapsed into the peak ring. Chicxulub is Earth's only crater to have an intact peak ring structure. More ideas are available. Peak ring (crater) A peak ring crater is a type of complex crater. A central peak is not seen, instead, a roughly circular peak (possibly discontinuous) surrounds the