The investigation and simulations of data obtained from drilling expeditions of the 200-kilometer Chicxulub impact crater on peninsula Yucatán (Mexico) attributed peak-ring formation to the collapse of uplifted oversized, unstable central peaks. Consequently, the rocks forming peak rings originate from the deep subsurface of the impact site. The Chicxulub impact 66 million years ago is linked to the mass extinction of the dinosaurs.