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Fri Sep 27, 2019, 06:41 PM

66-Million-Year-Old Fossil Site Preserves Animals Killed within Minutes of Chicxulub Impact (SciNews

OK, this is old news, but I hadn't seen it before -- apologies if dupe.


66-Million-Year-Old Fossil Site Preserves Animals Killed within Minutes of Chicxulub Impact

At a site dubbed Tanis in North Dakota’s Hell Creek Formation, paleontologists have unearthed an assemblage of exquisitely-preserved fossilized organisms — fish stacked one atop another and mixed in with burned tree trunks, conifer branches, mammals, mosasaur bones, insects, the partial carcass of a Triceratops, marine microorganisms called dinoflagellates and snail-like marine cephalopods called ammonites — that were killed suddenly in events triggered by the Chicxulub asteroid (or comet) strike off Mexico’s Yucatan Peninsula, the impact that eradicated about 75% of Earth’s animal and plant species 66 million years ago
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University of Kansas researcher Robert DePalma and his colleagues determined that the Tanis fish could not have been stranded and then buried by a typical tsunami, a single wave that would have reached this previously unknown arm of the Western Interior Seaway no less than 10 to 12 hours after the Chicxulub impact 1,864 miles (3,000 km) away, if it didn’t peter out before then.

“The tektites — glass beads formed in the atmosphere from rock melted by the impact — would have rained down within 45 min to an hour of the impact, unable to create mudholes if the seabed had not already been exposed,” the paleontologists said.

“Instead, seismic waves likely arrived within 10 min of the impact from what would have been the equivalent of a magnitude 10 or 11 earthquake, creating a seiche (standing wave) in the inland sea that is similar to water sloshing in a bathtub during an earthquake.”

“The seismic waves start arising within 9-10 min of the impact, so they had a chance to get the water sloshing before all the spherules had fallen out of the sky,” said Professor Mark Richards, from the University of California, Berkeley and the University of Washington.
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more: http://www.sci-news.com/paleontology/tanis-fossil-site-07055.html

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Reply 66-Million-Year-Old Fossil Site Preserves Animals Killed within Minutes of Chicxulub Impact (SciNews (Original post)
eppur_se_muova Sep 27 OP
tblue37 Sep 27 #1
EveHammond13 Sep 27 #2
Jarqui Sep 27 #3
PoindexterOglethorpe Sep 27 #4
littlemissmartypants Sep 28 #5

Response to eppur_se_muova (Original post)

Fri Sep 27, 2019, 06:43 PM

1. K&R. Yeah, 66 million years is pretty old news. nt

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Response to eppur_se_muova (Original post)

Fri Sep 27, 2019, 06:52 PM

2. He is related to director Brian DePalma. FYI.

this is an extraordinary find.

Here is an absolutely amazing article about it.

https://www.newyorker.com/magazine/2019/04/08/the-day-the-dinosaurs-died

one of the best pieces of writing I have ever read

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Response to eppur_se_muova (Original post)

Fri Sep 27, 2019, 06:53 PM

3. I really enjoyed this story on it .. it's several pages long though

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Response to eppur_se_muova (Original post)

Fri Sep 27, 2019, 07:09 PM

4. I don't know if it's been posted here before,

although I've read about that site.

It's pretty amazing.

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Response to eppur_se_muova (Original post)

Sat Sep 28, 2019, 07:16 AM

5. Fantastic! Thank you so much! nt

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