Chicxulub

Chicxulub is a large impact crater buried under the Yucatán Peninsula and the adjacent Gulf of Mexico. Estimates place its diameter at roughly 150 to 200 kilometers, making it one of the largest confirmed impact structures on Earth. It formed about 66 million years ago at the Cretaceous–Paleogene boundary, an event linked to the mass extinction that eradicated most dinosaurs and many other life forms.

The crater was inferred from a pronounced circular gravity anomaly and offshore seismic data collected on the continental shelf during the late 20th century. It is named after Chicxulub, a town on the Yucatán mainland. In the 1990s, offshore drilling and detailed seismic studies recovered shocked minerals, melt rocks, and ejecta layers, providing definitive evidence of an extraterrestrial impact.

Chicxulub’s center lies offshore, beneath several kilometers of sediment. The structure exhibits a complex crater morphology, including a peak-ring system that is now buried beneath sediments rather than exposed at the surface. This buried state makes the crater one of the best-preserved large impact structures known.

Chicxulub is widely cited as the primary trigger for the Cretaceous–Paleogene extinction event. The scale of the impact would have produced massive tsunamis, global climatic perturbations, and widespread wildfires. Ongoing research aims to refine exact timing and the sequence of environmental effects, as well as to illuminate impact processes more generally.