Chicxulub crater Chicxulub crater 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 boundary (K–Pg boundary), slightly less than 66 million years ago, and a widely accepted theory is that worldwide climate disruption from the event was the cause of the Cretaceous–Paleogene extinction event, a mass extinction in which 75% of plant
Chesapeake Bay impact crater from oil exploration revealed the extent of the crater. The continual slumping of the rubble within the crater has affected the flow of the rivers and shaped the Chesapeake Bay. The impact crater created a long-lasting topographic depression which helped predetermine the course of local rivers and the eventual location of Chesapeake Bay. Most important for present-day inhabitants of the area, the impact disrupted aquifers. The present freshwater aquifers lie above a deep salty brine, remnants of 100–145 million year old Early Cretaceous North Atlantic seawater, making the entire lower Chesapeake Bay area susceptible to groundwater contamination. The crater is