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A seismically induced onshore surge deposit at the KPg boundary, North Dakota
Proceedings of the National Academy of Sciences ^ | April 1, 2019 | Robert A. DePalma

Posted on 04/04/2019 8:16:25 AM PDT by centurion316

The most immediate effects of the terminal-Cretaceous Chicxulub impact, essential to understanding the global-scale environmental and biotic collapses that mark the Cretaceous–Paleogene extinction, are poorly resolved despite extensive previous work. Here, we help to resolve this by describing a rapidly emplaced, high-energy onshore surge deposit from the terrestrial Hell Creek Formation in Montana. Associated ejecta and a cap of iridium-rich impactite reveal that its emplacement coincided with the Chicxulub event. Acipenseriform fish, densely packed in the deposit, contain ejecta spherules in their gills and were buried by an inland-directed surge that inundated a deeply incised river channel before accretion of the fine-grained impactite. Although this deposit displays all of the physical characteristics of a tsunami runup, the timing (<1 hour postimpact) is instead consistent with the arrival of strong seismic waves from the magnitude Mw ∼10 to 11 earthquake generated by the Chicxulub impact, identifying a seismically coupled seiche inundation as the likely cause. Our findings present high-resolution chronology of the immediate aftereffects of the Chicxulub impact event in the Western Interior, and report an impact-triggered onshore mix of marine and terrestrial sedimentation—potentially a significant advancement for eventually resolving both the complex dynamics of debris ejection and the full nature and extent of biotic disruptions that took place in the first moments postimpact.

(Excerpt) Read more at pnas.org ...


TOPICS: Astronomy; Science
KEYWORDS: asteroid; astronomy; catastrophism; chicxulub; cretaceous; deathassemblage; dinosaurs; godsgravesglyphs; hellcreek; jansmit; northdakota; paleogene; paleontology; robertadepalma; robertdepalma; science
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Many in the popular press have reported this, including a Fox News report posted here.

http://www.freerepublic.com/focus/f-chat/3738988/posts

The best popular press account comes from the New Yorker that can be found here:

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

For those who want to read the scientific paper, this is the place to go. It is long and detailed but most of it is easily understood by amateurs and those interested in paleontology.

The principle researcher, Robert DePalma is making quite a stir and the long knives in the bone digger crowd are out in full cry. You see, he doesn't have his PhD yet and he doesn't have the proper appointment in an accepted research center. In other words, he is an outsider. If fact he has been to known to have sold some of his finds and of course, this find, is potentially the biggest in the history of the discipline has a few upset. The cat fights have just begun.

1 posted on 04/04/2019 8:16:25 AM PDT by centurion316
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To: centurion316

With news like this, we can all take tomorrow off.


2 posted on 04/04/2019 8:18:00 AM PDT by PGR88
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To: SunkenCiv

Ping.

L


3 posted on 04/04/2019 8:21:45 AM PDT by Lurker (Peaceful coexistence with the Left is not possible. Stop pretending that it is.)
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To: centurion316

Well, duh!........................


4 posted on 04/04/2019 8:23:43 AM PDT by Red Badger (We are headed for a Civil War. It won't be nice like the last one....................)
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To: centurion316
Chicxulub, the Dinosaur’s End, Op 127
5 posted on 04/04/2019 8:31:22 AM PDT by BigEdLB (BigEdLB, Russian BOT, At your service)
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To: centurion316

I notice there is no mention of dinosaurs in this article so it may be better received.

That’s an issue because there is very little evidence for dinosaurs within 100,000 years of the asteroid impact time.


6 posted on 04/04/2019 8:36:50 AM PDT by Moonman62 (Facts are racist.)
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To: centurion316

Reading this gives me insight to where Frank Herbert got his naming ideas for Dune...


7 posted on 04/04/2019 8:39:34 AM PDT by rjsimmon (The Tree of Liberty Thirsts)
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To: Moonman62

There are no mentions of dinosaurs in the published paper. In the New Yorker article, DePalma says that he has found dinosaur fossils in the same sediments with tektites and iridium, including skin fossils. These finds need to be described and published in a follow on paper which he has said he will do. Those who have seen the site and have seen many of the finds estimate that it will take at least 50 years to research the site and there is more that has yet to be discovered.


8 posted on 04/04/2019 8:46:59 AM PDT by centurion316
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The inhabitants should have saved themselves by adopting the green new deal...


9 posted on 04/04/2019 8:54:25 AM PDT by TnTnTn
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To: centurion316

If you are a classic Doctor Who fan then you will know that it was Adric who manned the out of control space ship into the Earth, killing lots of stuff.


10 posted on 04/04/2019 9:15:54 AM PDT by PIF (They came for me and mine ... now it is your turn ...)
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To: PIF

I favored the Bond films.


11 posted on 04/04/2019 9:19:04 AM PDT by centurion316
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To: centurion316

I favored the Bond films.


Yeah, the girls were far better looking, but no large crater 60mya was created in Bond films. So we’re stuck with Adric or as he’s fondly remembered: Crater Boy.


12 posted on 04/04/2019 9:59:45 AM PDT by PIF (They came for me and mine ... now it is your turn ...)
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To: PGR88

It use to be 65 million years ago and the KT boundary.
BC / AD is now CE
Next they will want us to use the metric system.


13 posted on 04/04/2019 10:00:22 AM PDT by minnesota_bound (My sister said the only thing that did not was the clock. GE has spare parts)
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To: Lurker
Thanks Lurker. This may be related to a recent topic regarding a K-T death assemblage.



14 posted on 04/04/2019 12:46:11 PM PDT by SunkenCiv (Imagine an imaginary menagerie manager imagining managing an imaginary menagerie.)
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To: StayAt HomeMother; Ernest_at_the_Beach; 1ofmanyfree; 21twelve; 24Karet; 2ndDivisionVet; 31R1O; ...
Thanks Lurker.

15 posted on 04/04/2019 12:46:16 PM PDT by SunkenCiv (Imagine an imaginary menagerie manager imagining managing an imaginary menagerie.)
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To: centurion316

If only they had signed the Paris Climate Accords, it wouldn’t have happened . . .


16 posted on 04/04/2019 1:33:50 PM PDT by colorado tanker
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To: centurion316

very interesting New Yorker article as you point out


17 posted on 04/04/2019 1:41:55 PM PDT by KC Burke (If all the world is a stage, I would like to request my lighting be adjusted.)
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To: centurion316
"magnitude Mw ∼10 to 11 earthquake...." Yeah, that would tend to ruin your day. And a lot of others too. (A lot of other people, and a lot of other days!).
18 posted on 04/04/2019 3:22:44 PM PDT by 21twelve (!)
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To: SunkenCiv
Yes, it is directly related, in that it describes the effect of the seiche that created the fossil bed deposit it features.

If I have timeI may upload a couple of enhancements I did of images from the earlier article -- for a colleague who is working to re-introcuce the paddlefish to a Texas waterway drainage and lake...

TXnMA
 

19 posted on 04/04/2019 3:39:58 PM PDT by TXnMA (Remember the Alamo! | Remember Goliad! | REPEAT San Jacinto!!)
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To: centurion316; SunkenCiv; BenLurkin; blam; Red Badger; All

For those who like pictures or have grandchildren interested in this kind of thing, the link below has some nice graphics.

https://news.berkeley.edu/2019/03/29/66-million-year-old-deathbed-linked-to-dinosaur-killing-meteor/


20 posted on 04/04/2019 10:42:46 PM PDT by gleeaikin
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