I've seen this movie: DON'T DIG IT OUT !!
From ScienceAlert, March 11:
An enormous impact crater, hiding deep beneath Greenland's Hiawatha glacier, is probably the result of a kilometer-wide asteroid that crashed into Earth 58 million years ago.
That's much older than scientists presumed – roughly eight million years after the infamous impact that killed off most dinosaurs.
When the Hiawatha crater was first discovered in 2015, researchers suspected it was made by a meteorite sometime between 12,000 years ago and three million years ago.
These dates roughly bookend the last ice age, and judging from the conditions of the crater, the asteroid that created it seemed to have crashed into an already formed ice sheet.
But that's mostly based on circumstantial evidence, like radar scanning. In the years since the 31-kilometer-wide indent (19.3 miles) was first discovered, researchers have been trying to figure out its true age.
Given that much of the evidence lies beneath a kilometer of ice, however, direct evidence has proved difficult to gather.
Using two different dating methods, researchers from Denmark and Sweden have now both landed on a similar date – one that experts weren't expecting....
....MUCH MORE
Somewhere between 12,000 and 3,000,000 years ago seems a rather wide range. So I followed the "bookend" link and found it to be quite interesting, though not very informative on the instant question. From NOAA's Climate.gov, February 18, 2021:
