Shatter cones are formed by the passage of the explosion shock
wave through the rock. They are best preserved and identified in
fine-grained rocks. These Shatter cones mostly in Shale
Since the impact event 2 Billion years ago, there has been
about 10km of erosion (i.e. these structures were formed 10km beneath
the surface) This is about the best example I've seen.
Sudbury in Canada