Reality update: Here’s what happened in the impact crater the day it did in the dinos | Ars Technica … :
“Big enough impact craters actually have a knob of uplifted rock in the center that forms due to the incredible shock forces involved. But the very largest impacts—like Chicxulub—end up with a ring of uplifted rock around the center, as if to mark the bulls-eye. Computer modeling, supported by observations of the deepest bedrock in the core, shows that the rock would have bounced around like jelly. Over 10 minutes or so, a new mountain would have soared into the sky before collapsing and spreading out into a raised ring on the crater floor.“