In 2016 a joint IODP–ICDP drilling expedition cored into the Chicxulub crater, the buried remains of the asteroid impact off Mexico’s Yucatán Peninsula that wiped out the dinosaurs 66 million years ago. It was the first effort to sample the crater’s peak ring, a circle of hills inside the rim that is common on the Moon, Mars and Mercury but well preserved nowhere else on Earth.
Cores from about 670 metres below the sea floor contained shocked granite from deep in the crust sitting on top of younger sedimentary rock. That out-of-order stacking supports the dynamic collapse model: within minutes of the impact, deep rock rebounded into a central peak as tall as 10 kilometres and then collapsed outward into the ring.
via Updated: Drilling of dinosaur-killing impact crater explains buried circular hills | Science