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
Foelsche crater layer of magnetic rock (igneous sill) by the impact event. The age of Foelsche is not well constrained, but it must be younger than the Mesoproterozoic target rocks and older than the Neoproterozoic rocks that partly fill the crater; it has been argued that the age is most likely Neoproterozoic because it appears that the crater was covered by sediments soon after the impact event. Foelsche crater Foelsche is a partly buried impact structure (or astrobleme), the eroded remnant of a former impact crater. It is situated about 85 km southeast of Borroloola in the Northern Territory, Australia, and named