[Rockhounds] Massive meteor crater discovered beneath Greenland's ice is much older than thought

[Tim Fisher]

So that's what happened to the Arctic dinosaurs!

Tim Fisher
Http://OreRockOn.com 
Email nospam at orerockon.com




-----Original Message-----
From: Rockhounds [mailto:rockhounds-bounces at rockhounds.drizzle.com] On
Behalf Of Kreigh Tomaszewski
Sent: Wednesday, March 09, 2022 2:22 PM
To: Rockhounds at drizzle.com: A mailing list for rock and gem collectors
Subject: [Rockhounds] Massive meteor crater discovered beneath Greenland's
ice is much older than thought

The age of a 31-kilometer (19-mile) wide meteorite crater discovered under a
kilometer of Greenland ice had long puzzled scientists.

The Hiawatha crater was exceptionally well preserved despite glacier ice
being incredibly effective at erosion. Its state fueled talk that the
meteorite might have hit as recently as 13,000 years ago.
However, the crater, which is one of the world's largest, has now been
definitively dated -- and it is much, much older. In fact, it slammed into
the Earth just a few million years after dinosaurs went extinct, about 58
million years ago.

"Dating the crater has been a particularly tough nut to crack, so it's very
satisfying that two laboratories in Denmark and Sweden, using different
dating methods arrived at the same conclusion. As such, I'm convinced that
we've determined the crater's actual age, which is much older than many
people once thought," said Michael Storey, head of geology at the Natural
History Museum of Denmark, in a news release.
When the asteroid hit, the Arctic was covered in balmy rainforest with
temperatures of around 68 degrees Fahrenheit (20 degrees Celsius). Local
inhabitants would have included crocodiles, turtles and primitive hippo-like
animals, said Storey, who was an author of a new paper on the crater
published in the journal Science Advances.
The Hiawatha impact crater could swallow up Washington DC and is larger than
about 90% of the roughly 200 previously known impact craters on Earth.

https://www.cnn.com/2022/03/09/world/crater-greenland-age-scn/index.html
_______________________________________________
Rockhounds mailing list
Subscription Services:
http://rockhounds.drizzle.com/mailman/listinfo/rockhounds_rockhounds.drizzle
.com
List Usage Policy: http://Tomaszewski.net/Kreigh/Rockhounds/Rockhounds.shtml