Why is there usually a peak at the center of a meteorite impact crater?
At the moment of impact the the grounds is heated, some vaporized and some liquefied, and a lot blasted out in all phases. including solids. The push and blast leave a hollow volume momentarily. The ground around the impact flows back into the hole immediately even as the shock wave is moving pst it. WHen the ground moving into the center from all directions (usually more or less circular) it smacks into all the other return material and is pushed up at the center. WHat is pushed up is often a mix of solids and molten material and it “freezes” into the center peak. It is the same peak you see when you drop a rock in water but in the water the rising drop does not solidify and stay put.
