Earth's most ancient impact craters are disappearing

Investigating ancient impact craters - before they entirely erode.

Perhaps some of the value is in identifying the primary evidence that remains in ancient craters, to know what to look for in other location where ancient craters may exist that have eroded away.

There could be evidence of huge ancient, at least prehistoric Oceanuc impacts impact craters. Finding them is another story. Don't know if the technology used provides accurate result in the oceans, or if there have been efforts to use it. There are several oceanic locations that suggest it would be a good idea to look for evidence of large impacts.