Study supports theory of extraterrestrial impact

[Tank]

Study supports theory of extraterrestrial impact

A 16-member international team of researchers that includes James Kennett, professor of earth science at UC Santa Barbara, has identified a nearly 13,000-year-old layer of thin, dark sediment buried in the floor of Lake Cuitzeo in central Mexico. The sediment layer contains an exotic assemblage of materials, including nanodiamonds, impact spherules, and more, which, according to the researchers, are the result of a cosmic body impacting Earth.

These new data are the latest to strongly support of a controversial hypothesis proposing that a major cosmic impact with Earth occurred 12,900 years ago at the onset of an unusual cold climatic period called the Younger Dryas. The researchers' findings appear today in the Proceedings of the National Academy of Sciences...

...In the entire geologic record, there are only two known continent-wide layers with abundance peaks in nanodiamonds, impact spherules, and aciniform soot. These are in the 65-million-year-old Cretaceous-Paleogene boundary layer that coincided with major extinctions, including the dinosaurs and ammonites; and the Younger Dryas boundary event at 12,900 years ago, closely associated with the extinctions of many large North American animals, including mammoths, mastodons, saber-tooth cats, and dire wolves....

Interesting, the large fauna extinctions have often been attributed to the depredations of early humans.

[Too Few Lions]

interesting post, thanks Tank. It's nice to think that the extinctions of all those great beasts may not have (solely) been the result of humans hunting them

[OldGit]

Interesting - Mexico again.  And the meteor crater in Arizona is not far away on a global scale.  Maybe the Lord is aiming at something. 

[Tank]

Interesting - Mexico again.  And the meteor crater in Arizona is not far away on a global scale.  Maybe the Lord is aiming at something. 

Shame it wasn't the Vatican.

[Guardian85]

Interesting - Mexico again.  And the meteor crater in Arizona is not far away on a global scale.  Maybe the Lord is aiming at something. 

Probably aiming for the american bible belt! 

[Sandra Craft]

Interesting - Mexico again.  And the meteor crater in Arizona is not far away on a global scale.  Maybe the Lord is aiming at something. 

Probably aiming for the american bible belt! 

He's got some explaining to do for missing so badly.

[Recusant]

Another fascinating and rich fossil find, this time from the K–Pg boundary (formerly and to some extent still also called the K-T boundary).

"66-million-year-old deathbed linked to dinosaur-killing meteor" | ScienceDaily

Fossilized fish piled one atop another, suggesting that they were flung ashore and died stranded
together on a sand bar after the wave from the seiche withdrew.
Image credit:  Robert DePalma

The beginning of the end started with violent shaking that raised giant waves in the waters of an inland sea in what is now North Dakota.

Then, tiny glass beads began to fall like birdshot from the heavens. The rain of glass was so heavy it may have set fire to much of the vegetation on land. In the water, fish struggled to breathe as the beads clogged their gills.

The heaving sea turned into a 30-foot wall of water when it reached the mouth of a river, tossing hundreds, if not thousands, of fresh-water fish -- sturgeon and paddlefish -- onto a sand bar and temporarily reversing the flow of the river. Stranded by the receding water, the fish were pelted by glass beads up to 5 millimeters in diameter, some burying themselves inches deep in the mud. The torrent of rocks, like fine sand, and small glass beads continued for another 10 to 20 minutes before a second large wave inundated the shore and covered the fish with gravel, sand and fine sediment, sealing them from the world for 66 million years.

This unique, fossilized graveyard -- fish stacked one atop another and mixed in with burned tree trunks, conifer branches, dead mammals, mosasaur bones, insects, the partial carcass of a Triceratops, marine microorganisms called dinoflagellates and snail-like marine cephalopods called ammonites -- was unearthed by paleontologist Robert DePalma over the past six years in the Hell Creek Formation, not far from Bowman, North Dakota. The evidence confirms a suspicion that nagged at DePalma in his first digging season during the summer of 2013 -- that this was a killing field laid down soon after the asteroid impact that eventually led to the extinction of all ground-dwelling dinosaurs. The impact at the end of the Cretaceous Period, the so-called K-T boundary, exterminated 75 percent of life on Earth.

[Continues . . .]

[Bluenose]

Another fascinating and rich fossil find, this time from the K–Pg boundary (formerly and to some extent still also called the K-T boundary).

For other fossils like myself who had not heard of the K-Pg boundary, this is the Cretaceous-Palaeogene boundary, the Palaeogene being the first period of the Cenozoic era.  This was previously known as the K-T boundary, the Cretaceous-Tertiary boundary, which is the name I was familiar with.  It's always a good day when you learn something new.  Thank you Recusant!

[Icarus]

Fascinating stuff Recusant.  Thanks for the reference article. 

[billy rubin]

more on recusant's post.


https://www.pnas.org/content/116/17/8190

^^^this PNAS paper  (with alvarez in the author list, even) appears to be the last overall publication about this site, to date. there's a more recent one that discusses the sedimentary structure:

https://www.researchgate.net/publication/333716815_Supplementary_Information_for_A_SEISMICALLY_INDUCED_ONSHORE_SURGE_DEPOSIT_AT_THE_KPG_BOUNDARY_NORTH_DAKOTA

^^^this one

the paleontologica community is pissed off that depalma hasn't published more, and super pissed off that the PNAS paper didn't contain more about the dramatiuc claims in the original new yorker release. which wasn't exactly orthodox, to be sure.

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

one science writer is even pissed off at what she sees as a sexist program to deny recognition to female palaeontologists, none of which were there. didn't see that coming.

https://slate.com/technology/2019/04/what-the-new-yorker-dinosaur-story-gets-wrong.html

others are pissed off that depalma keeps ownership and control of the specimens in other institutions, rather than donating everything. but he doesn't get public money for his work, and has to find funding all on his own.

seems like everybody has something to hate about depalma's project. he has presented four papers on the site at conventions of the geological society of america. depalma still hasn't received a phd, which means he is snubbed by the scientific community, a place not known for small egos. i suspect he may skip the credentials, which he doesn't need at this point,  and continue publishing a spectacular examoination of his site as a student, thumbing his nose at the establishment.

at any rate, everything i read about this site is fascinating.









this last picture shows a freshwater fish dying alngside a marine cephalopod/ the little round things in the other pictures are glass spherules similar to tektites, melted biits of earth that rained down after th eimpact and choked the gills of fish still alive and made a layer on top of the cretaceous, at the bottom of the tertiary.

if you're a paleontologist, the depalma story is better than indiana jones.